mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
10023 lines
243 KiB
10023 lines
243 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
|
* Shared application/kernel submission and completion ring pairs, for |
|
* supporting fast/efficient IO. |
|
* |
|
* A note on the read/write ordering memory barriers that are matched between |
|
* the application and kernel side. |
|
* |
|
* After the application reads the CQ ring tail, it must use an |
|
* appropriate smp_rmb() to pair with the smp_wmb() the kernel uses |
|
* before writing the tail (using smp_load_acquire to read the tail will |
|
* do). It also needs a smp_mb() before updating CQ head (ordering the |
|
* entry load(s) with the head store), pairing with an implicit barrier |
|
* through a control-dependency in io_get_cqring (smp_store_release to |
|
* store head will do). Failure to do so could lead to reading invalid |
|
* CQ entries. |
|
* |
|
* Likewise, the application must use an appropriate smp_wmb() before |
|
* writing the SQ tail (ordering SQ entry stores with the tail store), |
|
* which pairs with smp_load_acquire in io_get_sqring (smp_store_release |
|
* to store the tail will do). And it needs a barrier ordering the SQ |
|
* head load before writing new SQ entries (smp_load_acquire to read |
|
* head will do). |
|
* |
|
* When using the SQ poll thread (IORING_SETUP_SQPOLL), the application |
|
* needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after* |
|
* updating the SQ tail; a full memory barrier smp_mb() is needed |
|
* between. |
|
* |
|
* Also see the examples in the liburing library: |
|
* |
|
* git://git.kernel.dk/liburing |
|
* |
|
* io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens |
|
* from data shared between the kernel and application. This is done both |
|
* for ordering purposes, but also to ensure that once a value is loaded from |
|
* data that the application could potentially modify, it remains stable. |
|
* |
|
* Copyright (C) 2018-2019 Jens Axboe |
|
* Copyright (c) 2018-2019 Christoph Hellwig |
|
*/ |
|
#include <linux/kernel.h> |
|
#include <linux/init.h> |
|
#include <linux/errno.h> |
|
#include <linux/syscalls.h> |
|
#include <linux/compat.h> |
|
#include <net/compat.h> |
|
#include <linux/refcount.h> |
|
#include <linux/uio.h> |
|
#include <linux/bits.h> |
|
|
|
#include <linux/sched/signal.h> |
|
#include <linux/fs.h> |
|
#include <linux/file.h> |
|
#include <linux/fdtable.h> |
|
#include <linux/mm.h> |
|
#include <linux/mman.h> |
|
#include <linux/percpu.h> |
|
#include <linux/slab.h> |
|
#include <linux/blkdev.h> |
|
#include <linux/bvec.h> |
|
#include <linux/net.h> |
|
#include <net/sock.h> |
|
#include <net/af_unix.h> |
|
#include <net/scm.h> |
|
#include <linux/anon_inodes.h> |
|
#include <linux/sched/mm.h> |
|
#include <linux/uaccess.h> |
|
#include <linux/nospec.h> |
|
#include <linux/sizes.h> |
|
#include <linux/hugetlb.h> |
|
#include <linux/highmem.h> |
|
#include <linux/namei.h> |
|
#include <linux/fsnotify.h> |
|
#include <linux/fadvise.h> |
|
#include <linux/eventpoll.h> |
|
#include <linux/splice.h> |
|
#include <linux/task_work.h> |
|
#include <linux/pagemap.h> |
|
#include <linux/io_uring.h> |
|
|
|
#define CREATE_TRACE_POINTS |
|
#include <trace/events/io_uring.h> |
|
|
|
#include <uapi/linux/io_uring.h> |
|
|
|
#include "internal.h" |
|
#include "io-wq.h" |
|
|
|
#define IORING_MAX_ENTRIES 32768 |
|
#define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES) |
|
|
|
/* |
|
* Shift of 9 is 512 entries, or exactly one page on 64-bit archs |
|
*/ |
|
#define IORING_FILE_TABLE_SHIFT 9 |
|
#define IORING_MAX_FILES_TABLE (1U << IORING_FILE_TABLE_SHIFT) |
|
#define IORING_FILE_TABLE_MASK (IORING_MAX_FILES_TABLE - 1) |
|
#define IORING_MAX_FIXED_FILES (64 * IORING_MAX_FILES_TABLE) |
|
#define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \ |
|
IORING_REGISTER_LAST + IORING_OP_LAST) |
|
|
|
#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \ |
|
IOSQE_IO_HARDLINK | IOSQE_ASYNC | \ |
|
IOSQE_BUFFER_SELECT) |
|
|
|
struct io_uring { |
|
u32 head ____cacheline_aligned_in_smp; |
|
u32 tail ____cacheline_aligned_in_smp; |
|
}; |
|
|
|
/* |
|
* This data is shared with the application through the mmap at offsets |
|
* IORING_OFF_SQ_RING and IORING_OFF_CQ_RING. |
|
* |
|
* The offsets to the member fields are published through struct |
|
* io_sqring_offsets when calling io_uring_setup. |
|
*/ |
|
struct io_rings { |
|
/* |
|
* Head and tail offsets into the ring; the offsets need to be |
|
* masked to get valid indices. |
|
* |
|
* The kernel controls head of the sq ring and the tail of the cq ring, |
|
* and the application controls tail of the sq ring and the head of the |
|
* cq ring. |
|
*/ |
|
struct io_uring sq, cq; |
|
/* |
|
* Bitmasks to apply to head and tail offsets (constant, equals |
|
* ring_entries - 1) |
|
*/ |
|
u32 sq_ring_mask, cq_ring_mask; |
|
/* Ring sizes (constant, power of 2) */ |
|
u32 sq_ring_entries, cq_ring_entries; |
|
/* |
|
* Number of invalid entries dropped by the kernel due to |
|
* invalid index stored in array |
|
* |
|
* Written by the kernel, shouldn't be modified by the |
|
* application (i.e. get number of "new events" by comparing to |
|
* cached value). |
|
* |
|
* After a new SQ head value was read by the application this |
|
* counter includes all submissions that were dropped reaching |
|
* the new SQ head (and possibly more). |
|
*/ |
|
u32 sq_dropped; |
|
/* |
|
* Runtime SQ flags |
|
* |
|
* Written by the kernel, shouldn't be modified by the |
|
* application. |
|
* |
|
* The application needs a full memory barrier before checking |
|
* for IORING_SQ_NEED_WAKEUP after updating the sq tail. |
|
*/ |
|
u32 sq_flags; |
|
/* |
|
* Runtime CQ flags |
|
* |
|
* Written by the application, shouldn't be modified by the |
|
* kernel. |
|
*/ |
|
u32 cq_flags; |
|
/* |
|
* Number of completion events lost because the queue was full; |
|
* this should be avoided by the application by making sure |
|
* there are not more requests pending than there is space in |
|
* the completion queue. |
|
* |
|
* Written by the kernel, shouldn't be modified by the |
|
* application (i.e. get number of "new events" by comparing to |
|
* cached value). |
|
* |
|
* As completion events come in out of order this counter is not |
|
* ordered with any other data. |
|
*/ |
|
u32 cq_overflow; |
|
/* |
|
* Ring buffer of completion events. |
|
* |
|
* The kernel writes completion events fresh every time they are |
|
* produced, so the application is allowed to modify pending |
|
* entries. |
|
*/ |
|
struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp; |
|
}; |
|
|
|
enum io_uring_cmd_flags { |
|
IO_URING_F_NONBLOCK = 1, |
|
IO_URING_F_COMPLETE_DEFER = 2, |
|
}; |
|
|
|
struct io_mapped_ubuf { |
|
u64 ubuf; |
|
size_t len; |
|
struct bio_vec *bvec; |
|
unsigned int nr_bvecs; |
|
unsigned long acct_pages; |
|
}; |
|
|
|
struct io_ring_ctx; |
|
|
|
struct io_rsrc_put { |
|
struct list_head list; |
|
union { |
|
void *rsrc; |
|
struct file *file; |
|
}; |
|
}; |
|
|
|
struct fixed_rsrc_table { |
|
struct file **files; |
|
}; |
|
|
|
struct fixed_rsrc_ref_node { |
|
struct percpu_ref refs; |
|
struct list_head node; |
|
struct list_head rsrc_list; |
|
struct fixed_rsrc_data *rsrc_data; |
|
void (*rsrc_put)(struct io_ring_ctx *ctx, |
|
struct io_rsrc_put *prsrc); |
|
struct llist_node llist; |
|
bool done; |
|
}; |
|
|
|
struct fixed_rsrc_data { |
|
struct fixed_rsrc_table *table; |
|
struct io_ring_ctx *ctx; |
|
|
|
struct fixed_rsrc_ref_node *node; |
|
struct percpu_ref refs; |
|
struct completion done; |
|
bool quiesce; |
|
}; |
|
|
|
struct io_buffer { |
|
struct list_head list; |
|
__u64 addr; |
|
__u32 len; |
|
__u16 bid; |
|
}; |
|
|
|
struct io_restriction { |
|
DECLARE_BITMAP(register_op, IORING_REGISTER_LAST); |
|
DECLARE_BITMAP(sqe_op, IORING_OP_LAST); |
|
u8 sqe_flags_allowed; |
|
u8 sqe_flags_required; |
|
bool registered; |
|
}; |
|
|
|
enum { |
|
IO_SQ_THREAD_SHOULD_STOP = 0, |
|
IO_SQ_THREAD_SHOULD_PARK, |
|
}; |
|
|
|
struct io_sq_data { |
|
refcount_t refs; |
|
atomic_t park_pending; |
|
struct mutex lock; |
|
|
|
/* ctx's that are using this sqd */ |
|
struct list_head ctx_list; |
|
|
|
struct task_struct *thread; |
|
struct wait_queue_head wait; |
|
|
|
unsigned sq_thread_idle; |
|
int sq_cpu; |
|
pid_t task_pid; |
|
pid_t task_tgid; |
|
|
|
unsigned long state; |
|
struct completion exited; |
|
struct callback_head *park_task_work; |
|
}; |
|
|
|
#define IO_IOPOLL_BATCH 8 |
|
#define IO_COMPL_BATCH 32 |
|
#define IO_REQ_CACHE_SIZE 32 |
|
#define IO_REQ_ALLOC_BATCH 8 |
|
|
|
struct io_comp_state { |
|
struct io_kiocb *reqs[IO_COMPL_BATCH]; |
|
unsigned int nr; |
|
unsigned int locked_free_nr; |
|
/* inline/task_work completion list, under ->uring_lock */ |
|
struct list_head free_list; |
|
/* IRQ completion list, under ->completion_lock */ |
|
struct list_head locked_free_list; |
|
}; |
|
|
|
struct io_submit_link { |
|
struct io_kiocb *head; |
|
struct io_kiocb *last; |
|
}; |
|
|
|
struct io_submit_state { |
|
struct blk_plug plug; |
|
struct io_submit_link link; |
|
|
|
/* |
|
* io_kiocb alloc cache |
|
*/ |
|
void *reqs[IO_REQ_CACHE_SIZE]; |
|
unsigned int free_reqs; |
|
|
|
bool plug_started; |
|
|
|
/* |
|
* Batch completion logic |
|
*/ |
|
struct io_comp_state comp; |
|
|
|
/* |
|
* File reference cache |
|
*/ |
|
struct file *file; |
|
unsigned int fd; |
|
unsigned int file_refs; |
|
unsigned int ios_left; |
|
}; |
|
|
|
struct io_ring_ctx { |
|
struct { |
|
struct percpu_ref refs; |
|
} ____cacheline_aligned_in_smp; |
|
|
|
struct { |
|
unsigned int flags; |
|
unsigned int compat: 1; |
|
unsigned int cq_overflow_flushed: 1; |
|
unsigned int drain_next: 1; |
|
unsigned int eventfd_async: 1; |
|
unsigned int restricted: 1; |
|
|
|
/* |
|
* Ring buffer of indices into array of io_uring_sqe, which is |
|
* mmapped by the application using the IORING_OFF_SQES offset. |
|
* |
|
* This indirection could e.g. be used to assign fixed |
|
* io_uring_sqe entries to operations and only submit them to |
|
* the queue when needed. |
|
* |
|
* The kernel modifies neither the indices array nor the entries |
|
* array. |
|
*/ |
|
u32 *sq_array; |
|
unsigned cached_sq_head; |
|
unsigned sq_entries; |
|
unsigned sq_mask; |
|
unsigned sq_thread_idle; |
|
unsigned cached_sq_dropped; |
|
unsigned cached_cq_overflow; |
|
unsigned long sq_check_overflow; |
|
|
|
/* hashed buffered write serialization */ |
|
struct io_wq_hash *hash_map; |
|
|
|
struct list_head defer_list; |
|
struct list_head timeout_list; |
|
struct list_head cq_overflow_list; |
|
|
|
struct io_uring_sqe *sq_sqes; |
|
} ____cacheline_aligned_in_smp; |
|
|
|
struct { |
|
struct mutex uring_lock; |
|
wait_queue_head_t wait; |
|
} ____cacheline_aligned_in_smp; |
|
|
|
struct io_submit_state submit_state; |
|
|
|
struct io_rings *rings; |
|
|
|
/* Only used for accounting purposes */ |
|
struct mm_struct *mm_account; |
|
|
|
const struct cred *sq_creds; /* cred used for __io_sq_thread() */ |
|
struct io_sq_data *sq_data; /* if using sq thread polling */ |
|
|
|
struct wait_queue_head sqo_sq_wait; |
|
struct list_head sqd_list; |
|
|
|
/* |
|
* If used, fixed file set. Writers must ensure that ->refs is dead, |
|
* readers must ensure that ->refs is alive as long as the file* is |
|
* used. Only updated through io_uring_register(2). |
|
*/ |
|
struct fixed_rsrc_data *file_data; |
|
unsigned nr_user_files; |
|
|
|
/* if used, fixed mapped user buffers */ |
|
unsigned nr_user_bufs; |
|
struct io_mapped_ubuf *user_bufs; |
|
|
|
struct user_struct *user; |
|
|
|
struct completion ref_comp; |
|
|
|
#if defined(CONFIG_UNIX) |
|
struct socket *ring_sock; |
|
#endif |
|
|
|
struct xarray io_buffers; |
|
|
|
struct xarray personalities; |
|
u32 pers_next; |
|
|
|
struct { |
|
unsigned cached_cq_tail; |
|
unsigned cq_entries; |
|
unsigned cq_mask; |
|
atomic_t cq_timeouts; |
|
unsigned cq_last_tm_flush; |
|
unsigned long cq_check_overflow; |
|
struct wait_queue_head cq_wait; |
|
struct fasync_struct *cq_fasync; |
|
struct eventfd_ctx *cq_ev_fd; |
|
} ____cacheline_aligned_in_smp; |
|
|
|
struct { |
|
spinlock_t completion_lock; |
|
|
|
/* |
|
* ->iopoll_list is protected by the ctx->uring_lock for |
|
* io_uring instances that don't use IORING_SETUP_SQPOLL. |
|
* For SQPOLL, only the single threaded io_sq_thread() will |
|
* manipulate the list, hence no extra locking is needed there. |
|
*/ |
|
struct list_head iopoll_list; |
|
struct hlist_head *cancel_hash; |
|
unsigned cancel_hash_bits; |
|
bool poll_multi_file; |
|
|
|
spinlock_t inflight_lock; |
|
struct list_head inflight_list; |
|
} ____cacheline_aligned_in_smp; |
|
|
|
struct delayed_work rsrc_put_work; |
|
struct llist_head rsrc_put_llist; |
|
struct list_head rsrc_ref_list; |
|
spinlock_t rsrc_ref_lock; |
|
|
|
struct io_restriction restrictions; |
|
|
|
/* exit task_work */ |
|
struct callback_head *exit_task_work; |
|
|
|
struct wait_queue_head hash_wait; |
|
|
|
/* Keep this last, we don't need it for the fast path */ |
|
struct work_struct exit_work; |
|
struct list_head tctx_list; |
|
}; |
|
|
|
struct io_uring_task { |
|
/* submission side */ |
|
struct xarray xa; |
|
struct wait_queue_head wait; |
|
const struct io_ring_ctx *last; |
|
struct io_wq *io_wq; |
|
struct percpu_counter inflight; |
|
atomic_t in_idle; |
|
bool sqpoll; |
|
|
|
spinlock_t task_lock; |
|
struct io_wq_work_list task_list; |
|
unsigned long task_state; |
|
struct callback_head task_work; |
|
}; |
|
|
|
/* |
|
* First field must be the file pointer in all the |
|
* iocb unions! See also 'struct kiocb' in <linux/fs.h> |
|
*/ |
|
struct io_poll_iocb { |
|
struct file *file; |
|
struct wait_queue_head *head; |
|
__poll_t events; |
|
bool done; |
|
bool canceled; |
|
struct wait_queue_entry wait; |
|
}; |
|
|
|
struct io_poll_remove { |
|
struct file *file; |
|
u64 addr; |
|
}; |
|
|
|
struct io_close { |
|
struct file *file; |
|
int fd; |
|
}; |
|
|
|
struct io_timeout_data { |
|
struct io_kiocb *req; |
|
struct hrtimer timer; |
|
struct timespec64 ts; |
|
enum hrtimer_mode mode; |
|
}; |
|
|
|
struct io_accept { |
|
struct file *file; |
|
struct sockaddr __user *addr; |
|
int __user *addr_len; |
|
int flags; |
|
unsigned long nofile; |
|
}; |
|
|
|
struct io_sync { |
|
struct file *file; |
|
loff_t len; |
|
loff_t off; |
|
int flags; |
|
int mode; |
|
}; |
|
|
|
struct io_cancel { |
|
struct file *file; |
|
u64 addr; |
|
}; |
|
|
|
struct io_timeout { |
|
struct file *file; |
|
u32 off; |
|
u32 target_seq; |
|
struct list_head list; |
|
/* head of the link, used by linked timeouts only */ |
|
struct io_kiocb *head; |
|
}; |
|
|
|
struct io_timeout_rem { |
|
struct file *file; |
|
u64 addr; |
|
|
|
/* timeout update */ |
|
struct timespec64 ts; |
|
u32 flags; |
|
}; |
|
|
|
struct io_rw { |
|
/* NOTE: kiocb has the file as the first member, so don't do it here */ |
|
struct kiocb kiocb; |
|
u64 addr; |
|
u64 len; |
|
}; |
|
|
|
struct io_connect { |
|
struct file *file; |
|
struct sockaddr __user *addr; |
|
int addr_len; |
|
}; |
|
|
|
struct io_sr_msg { |
|
struct file *file; |
|
union { |
|
struct user_msghdr __user *umsg; |
|
void __user *buf; |
|
}; |
|
int msg_flags; |
|
int bgid; |
|
size_t len; |
|
struct io_buffer *kbuf; |
|
}; |
|
|
|
struct io_open { |
|
struct file *file; |
|
int dfd; |
|
struct filename *filename; |
|
struct open_how how; |
|
unsigned long nofile; |
|
}; |
|
|
|
struct io_rsrc_update { |
|
struct file *file; |
|
u64 arg; |
|
u32 nr_args; |
|
u32 offset; |
|
}; |
|
|
|
struct io_fadvise { |
|
struct file *file; |
|
u64 offset; |
|
u32 len; |
|
u32 advice; |
|
}; |
|
|
|
struct io_madvise { |
|
struct file *file; |
|
u64 addr; |
|
u32 len; |
|
u32 advice; |
|
}; |
|
|
|
struct io_epoll { |
|
struct file *file; |
|
int epfd; |
|
int op; |
|
int fd; |
|
struct epoll_event event; |
|
}; |
|
|
|
struct io_splice { |
|
struct file *file_out; |
|
struct file *file_in; |
|
loff_t off_out; |
|
loff_t off_in; |
|
u64 len; |
|
unsigned int flags; |
|
}; |
|
|
|
struct io_provide_buf { |
|
struct file *file; |
|
__u64 addr; |
|
__u32 len; |
|
__u32 bgid; |
|
__u16 nbufs; |
|
__u16 bid; |
|
}; |
|
|
|
struct io_statx { |
|
struct file *file; |
|
int dfd; |
|
unsigned int mask; |
|
unsigned int flags; |
|
const char __user *filename; |
|
struct statx __user *buffer; |
|
}; |
|
|
|
struct io_shutdown { |
|
struct file *file; |
|
int how; |
|
}; |
|
|
|
struct io_rename { |
|
struct file *file; |
|
int old_dfd; |
|
int new_dfd; |
|
struct filename *oldpath; |
|
struct filename *newpath; |
|
int flags; |
|
}; |
|
|
|
struct io_unlink { |
|
struct file *file; |
|
int dfd; |
|
int flags; |
|
struct filename *filename; |
|
}; |
|
|
|
struct io_completion { |
|
struct file *file; |
|
struct list_head list; |
|
int cflags; |
|
}; |
|
|
|
struct io_async_connect { |
|
struct sockaddr_storage address; |
|
}; |
|
|
|
struct io_async_msghdr { |
|
struct iovec fast_iov[UIO_FASTIOV]; |
|
/* points to an allocated iov, if NULL we use fast_iov instead */ |
|
struct iovec *free_iov; |
|
struct sockaddr __user *uaddr; |
|
struct msghdr msg; |
|
struct sockaddr_storage addr; |
|
}; |
|
|
|
struct io_async_rw { |
|
struct iovec fast_iov[UIO_FASTIOV]; |
|
const struct iovec *free_iovec; |
|
struct iov_iter iter; |
|
size_t bytes_done; |
|
struct wait_page_queue wpq; |
|
}; |
|
|
|
enum { |
|
REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT, |
|
REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT, |
|
REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT, |
|
REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT, |
|
REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT, |
|
REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT, |
|
|
|
REQ_F_FAIL_LINK_BIT, |
|
REQ_F_INFLIGHT_BIT, |
|
REQ_F_CUR_POS_BIT, |
|
REQ_F_NOWAIT_BIT, |
|
REQ_F_LINK_TIMEOUT_BIT, |
|
REQ_F_ISREG_BIT, |
|
REQ_F_NEED_CLEANUP_BIT, |
|
REQ_F_POLLED_BIT, |
|
REQ_F_BUFFER_SELECTED_BIT, |
|
REQ_F_NO_FILE_TABLE_BIT, |
|
REQ_F_LTIMEOUT_ACTIVE_BIT, |
|
REQ_F_COMPLETE_INLINE_BIT, |
|
REQ_F_REISSUE_BIT, |
|
|
|
/* not a real bit, just to check we're not overflowing the space */ |
|
__REQ_F_LAST_BIT, |
|
}; |
|
|
|
enum { |
|
/* ctx owns file */ |
|
REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT), |
|
/* drain existing IO first */ |
|
REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT), |
|
/* linked sqes */ |
|
REQ_F_LINK = BIT(REQ_F_LINK_BIT), |
|
/* doesn't sever on completion < 0 */ |
|
REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT), |
|
/* IOSQE_ASYNC */ |
|
REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT), |
|
/* IOSQE_BUFFER_SELECT */ |
|
REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT), |
|
|
|
/* fail rest of links */ |
|
REQ_F_FAIL_LINK = BIT(REQ_F_FAIL_LINK_BIT), |
|
/* on inflight list, should be cancelled and waited on exit reliably */ |
|
REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT), |
|
/* read/write uses file position */ |
|
REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT), |
|
/* must not punt to workers */ |
|
REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT), |
|
/* has or had linked timeout */ |
|
REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT), |
|
/* regular file */ |
|
REQ_F_ISREG = BIT(REQ_F_ISREG_BIT), |
|
/* needs cleanup */ |
|
REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT), |
|
/* already went through poll handler */ |
|
REQ_F_POLLED = BIT(REQ_F_POLLED_BIT), |
|
/* buffer already selected */ |
|
REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT), |
|
/* doesn't need file table for this request */ |
|
REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT), |
|
/* linked timeout is active, i.e. prepared by link's head */ |
|
REQ_F_LTIMEOUT_ACTIVE = BIT(REQ_F_LTIMEOUT_ACTIVE_BIT), |
|
/* completion is deferred through io_comp_state */ |
|
REQ_F_COMPLETE_INLINE = BIT(REQ_F_COMPLETE_INLINE_BIT), |
|
/* caller should reissue async */ |
|
REQ_F_REISSUE = BIT(REQ_F_REISSUE_BIT), |
|
}; |
|
|
|
struct async_poll { |
|
struct io_poll_iocb poll; |
|
struct io_poll_iocb *double_poll; |
|
}; |
|
|
|
struct io_task_work { |
|
struct io_wq_work_node node; |
|
task_work_func_t func; |
|
}; |
|
|
|
/* |
|
* NOTE! Each of the iocb union members has the file pointer |
|
* as the first entry in their struct definition. So you can |
|
* access the file pointer through any of the sub-structs, |
|
* or directly as just 'ki_filp' in this struct. |
|
*/ |
|
struct io_kiocb { |
|
union { |
|
struct file *file; |
|
struct io_rw rw; |
|
struct io_poll_iocb poll; |
|
struct io_poll_remove poll_remove; |
|
struct io_accept accept; |
|
struct io_sync sync; |
|
struct io_cancel cancel; |
|
struct io_timeout timeout; |
|
struct io_timeout_rem timeout_rem; |
|
struct io_connect connect; |
|
struct io_sr_msg sr_msg; |
|
struct io_open open; |
|
struct io_close close; |
|
struct io_rsrc_update rsrc_update; |
|
struct io_fadvise fadvise; |
|
struct io_madvise madvise; |
|
struct io_epoll epoll; |
|
struct io_splice splice; |
|
struct io_provide_buf pbuf; |
|
struct io_statx statx; |
|
struct io_shutdown shutdown; |
|
struct io_rename rename; |
|
struct io_unlink unlink; |
|
/* use only after cleaning per-op data, see io_clean_op() */ |
|
struct io_completion compl; |
|
}; |
|
|
|
/* opcode allocated if it needs to store data for async defer */ |
|
void *async_data; |
|
u8 opcode; |
|
/* polled IO has completed */ |
|
u8 iopoll_completed; |
|
|
|
u16 buf_index; |
|
u32 result; |
|
|
|
struct io_ring_ctx *ctx; |
|
unsigned int flags; |
|
refcount_t refs; |
|
struct task_struct *task; |
|
u64 user_data; |
|
|
|
struct io_kiocb *link; |
|
struct percpu_ref *fixed_rsrc_refs; |
|
|
|
/* |
|
* 1. used with ctx->iopoll_list with reads/writes |
|
* 2. to track reqs with ->files (see io_op_def::file_table) |
|
*/ |
|
struct list_head inflight_entry; |
|
union { |
|
struct io_task_work io_task_work; |
|
struct callback_head task_work; |
|
}; |
|
/* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */ |
|
struct hlist_node hash_node; |
|
struct async_poll *apoll; |
|
struct io_wq_work work; |
|
}; |
|
|
|
struct io_tctx_node { |
|
struct list_head ctx_node; |
|
struct task_struct *task; |
|
struct io_ring_ctx *ctx; |
|
}; |
|
|
|
struct io_defer_entry { |
|
struct list_head list; |
|
struct io_kiocb *req; |
|
u32 seq; |
|
}; |
|
|
|
struct io_op_def { |
|
/* needs req->file assigned */ |
|
unsigned needs_file : 1; |
|
/* hash wq insertion if file is a regular file */ |
|
unsigned hash_reg_file : 1; |
|
/* unbound wq insertion if file is a non-regular file */ |
|
unsigned unbound_nonreg_file : 1; |
|
/* opcode is not supported by this kernel */ |
|
unsigned not_supported : 1; |
|
/* set if opcode supports polled "wait" */ |
|
unsigned pollin : 1; |
|
unsigned pollout : 1; |
|
/* op supports buffer selection */ |
|
unsigned buffer_select : 1; |
|
/* must always have async data allocated */ |
|
unsigned needs_async_data : 1; |
|
/* should block plug */ |
|
unsigned plug : 1; |
|
/* size of async data needed, if any */ |
|
unsigned short async_size; |
|
}; |
|
|
|
static const struct io_op_def io_op_defs[] = { |
|
[IORING_OP_NOP] = {}, |
|
[IORING_OP_READV] = { |
|
.needs_file = 1, |
|
.unbound_nonreg_file = 1, |
|
.pollin = 1, |
|
.buffer_select = 1, |
|
.needs_async_data = 1, |
|
.plug = 1, |
|
.async_size = sizeof(struct io_async_rw), |
|
}, |
|
[IORING_OP_WRITEV] = { |
|
.needs_file = 1, |
|
.hash_reg_file = 1, |
|
.unbound_nonreg_file = 1, |
|
.pollout = 1, |
|
.needs_async_data = 1, |
|
.plug = 1, |
|
.async_size = sizeof(struct io_async_rw), |
|
}, |
|
[IORING_OP_FSYNC] = { |
|
.needs_file = 1, |
|
}, |
|
[IORING_OP_READ_FIXED] = { |
|
.needs_file = 1, |
|
.unbound_nonreg_file = 1, |
|
.pollin = 1, |
|
.plug = 1, |
|
.async_size = sizeof(struct io_async_rw), |
|
}, |
|
[IORING_OP_WRITE_FIXED] = { |
|
.needs_file = 1, |
|
.hash_reg_file = 1, |
|
.unbound_nonreg_file = 1, |
|
.pollout = 1, |
|
.plug = 1, |
|
.async_size = sizeof(struct io_async_rw), |
|
}, |
|
[IORING_OP_POLL_ADD] = { |
|
.needs_file = 1, |
|
.unbound_nonreg_file = 1, |
|
}, |
|
[IORING_OP_POLL_REMOVE] = {}, |
|
[IORING_OP_SYNC_FILE_RANGE] = { |
|
.needs_file = 1, |
|
}, |
|
[IORING_OP_SENDMSG] = { |
|
.needs_file = 1, |
|
.unbound_nonreg_file = 1, |
|
.pollout = 1, |
|
.needs_async_data = 1, |
|
.async_size = sizeof(struct io_async_msghdr), |
|
}, |
|
[IORING_OP_RECVMSG] = { |
|
.needs_file = 1, |
|
.unbound_nonreg_file = 1, |
|
.pollin = 1, |
|
.buffer_select = 1, |
|
.needs_async_data = 1, |
|
.async_size = sizeof(struct io_async_msghdr), |
|
}, |
|
[IORING_OP_TIMEOUT] = { |
|
.needs_async_data = 1, |
|
.async_size = sizeof(struct io_timeout_data), |
|
}, |
|
[IORING_OP_TIMEOUT_REMOVE] = { |
|
/* used by timeout updates' prep() */ |
|
}, |
|
[IORING_OP_ACCEPT] = { |
|
.needs_file = 1, |
|
.unbound_nonreg_file = 1, |
|
.pollin = 1, |
|
}, |
|
[IORING_OP_ASYNC_CANCEL] = {}, |
|
[IORING_OP_LINK_TIMEOUT] = { |
|
.needs_async_data = 1, |
|
.async_size = sizeof(struct io_timeout_data), |
|
}, |
|
[IORING_OP_CONNECT] = { |
|
.needs_file = 1, |
|
.unbound_nonreg_file = 1, |
|
.pollout = 1, |
|
.needs_async_data = 1, |
|
.async_size = sizeof(struct io_async_connect), |
|
}, |
|
[IORING_OP_FALLOCATE] = { |
|
.needs_file = 1, |
|
}, |
|
[IORING_OP_OPENAT] = {}, |
|
[IORING_OP_CLOSE] = {}, |
|
[IORING_OP_FILES_UPDATE] = {}, |
|
[IORING_OP_STATX] = {}, |
|
[IORING_OP_READ] = { |
|
.needs_file = 1, |
|
.unbound_nonreg_file = 1, |
|
.pollin = 1, |
|
.buffer_select = 1, |
|
.plug = 1, |
|
.async_size = sizeof(struct io_async_rw), |
|
}, |
|
[IORING_OP_WRITE] = { |
|
.needs_file = 1, |
|
.unbound_nonreg_file = 1, |
|
.pollout = 1, |
|
.plug = 1, |
|
.async_size = sizeof(struct io_async_rw), |
|
}, |
|
[IORING_OP_FADVISE] = { |
|
.needs_file = 1, |
|
}, |
|
[IORING_OP_MADVISE] = {}, |
|
[IORING_OP_SEND] = { |
|
.needs_file = 1, |
|
.unbound_nonreg_file = 1, |
|
.pollout = 1, |
|
}, |
|
[IORING_OP_RECV] = { |
|
.needs_file = 1, |
|
.unbound_nonreg_file = 1, |
|
.pollin = 1, |
|
.buffer_select = 1, |
|
}, |
|
[IORING_OP_OPENAT2] = { |
|
}, |
|
[IORING_OP_EPOLL_CTL] = { |
|
.unbound_nonreg_file = 1, |
|
}, |
|
[IORING_OP_SPLICE] = { |
|
.needs_file = 1, |
|
.hash_reg_file = 1, |
|
.unbound_nonreg_file = 1, |
|
}, |
|
[IORING_OP_PROVIDE_BUFFERS] = {}, |
|
[IORING_OP_REMOVE_BUFFERS] = {}, |
|
[IORING_OP_TEE] = { |
|
.needs_file = 1, |
|
.hash_reg_file = 1, |
|
.unbound_nonreg_file = 1, |
|
}, |
|
[IORING_OP_SHUTDOWN] = { |
|
.needs_file = 1, |
|
}, |
|
[IORING_OP_RENAMEAT] = {}, |
|
[IORING_OP_UNLINKAT] = {}, |
|
}; |
|
|
|
static bool io_disarm_next(struct io_kiocb *req); |
|
static void io_uring_del_task_file(unsigned long index); |
|
static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx, |
|
struct task_struct *task, |
|
struct files_struct *files); |
|
static void io_uring_cancel_sqpoll(struct io_sq_data *sqd); |
|
static void destroy_fixed_rsrc_ref_node(struct fixed_rsrc_ref_node *ref_node); |
|
static struct fixed_rsrc_ref_node *alloc_fixed_rsrc_ref_node( |
|
struct io_ring_ctx *ctx); |
|
static void io_ring_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc); |
|
|
|
static bool io_rw_reissue(struct io_kiocb *req); |
|
static void io_cqring_fill_event(struct io_kiocb *req, long res); |
|
static void io_put_req(struct io_kiocb *req); |
|
static void io_put_req_deferred(struct io_kiocb *req, int nr); |
|
static void io_double_put_req(struct io_kiocb *req); |
|
static void io_dismantle_req(struct io_kiocb *req); |
|
static void io_put_task(struct task_struct *task, int nr); |
|
static void io_queue_next(struct io_kiocb *req); |
|
static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req); |
|
static void __io_queue_linked_timeout(struct io_kiocb *req); |
|
static void io_queue_linked_timeout(struct io_kiocb *req); |
|
static int __io_sqe_files_update(struct io_ring_ctx *ctx, |
|
struct io_uring_rsrc_update *ip, |
|
unsigned nr_args); |
|
static void __io_clean_op(struct io_kiocb *req); |
|
static struct file *io_file_get(struct io_submit_state *state, |
|
struct io_kiocb *req, int fd, bool fixed); |
|
static void __io_queue_sqe(struct io_kiocb *req); |
|
static void io_rsrc_put_work(struct work_struct *work); |
|
|
|
static int io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec, |
|
struct iov_iter *iter, bool needs_lock); |
|
static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec, |
|
const struct iovec *fast_iov, |
|
struct iov_iter *iter, bool force); |
|
static void io_req_task_queue(struct io_kiocb *req); |
|
static void io_submit_flush_completions(struct io_comp_state *cs, |
|
struct io_ring_ctx *ctx); |
|
|
|
static struct kmem_cache *req_cachep; |
|
|
|
static const struct file_operations io_uring_fops; |
|
|
|
struct sock *io_uring_get_socket(struct file *file) |
|
{ |
|
#if defined(CONFIG_UNIX) |
|
if (file->f_op == &io_uring_fops) { |
|
struct io_ring_ctx *ctx = file->private_data; |
|
|
|
return ctx->ring_sock->sk; |
|
} |
|
#endif |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(io_uring_get_socket); |
|
|
|
#define io_for_each_link(pos, head) \ |
|
for (pos = (head); pos; pos = pos->link) |
|
|
|
static inline void io_clean_op(struct io_kiocb *req) |
|
{ |
|
if (req->flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED)) |
|
__io_clean_op(req); |
|
} |
|
|
|
static inline void io_set_resource_node(struct io_kiocb *req) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
if (!req->fixed_rsrc_refs) { |
|
req->fixed_rsrc_refs = &ctx->file_data->node->refs; |
|
percpu_ref_get(req->fixed_rsrc_refs); |
|
} |
|
} |
|
|
|
static bool io_match_task(struct io_kiocb *head, |
|
struct task_struct *task, |
|
struct files_struct *files) |
|
{ |
|
struct io_kiocb *req; |
|
|
|
if (task && head->task != task) { |
|
/* in terms of cancelation, always match if req task is dead */ |
|
if (head->task->flags & PF_EXITING) |
|
return true; |
|
return false; |
|
} |
|
if (!files) |
|
return true; |
|
|
|
io_for_each_link(req, head) { |
|
if (req->flags & REQ_F_INFLIGHT) |
|
return true; |
|
} |
|
return false; |
|
} |
|
|
|
static inline void req_set_fail_links(struct io_kiocb *req) |
|
{ |
|
if ((req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) == REQ_F_LINK) |
|
req->flags |= REQ_F_FAIL_LINK; |
|
} |
|
|
|
static void io_ring_ctx_ref_free(struct percpu_ref *ref) |
|
{ |
|
struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs); |
|
|
|
complete(&ctx->ref_comp); |
|
} |
|
|
|
static inline bool io_is_timeout_noseq(struct io_kiocb *req) |
|
{ |
|
return !req->timeout.off; |
|
} |
|
|
|
static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) |
|
{ |
|
struct io_ring_ctx *ctx; |
|
int hash_bits; |
|
|
|
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); |
|
if (!ctx) |
|
return NULL; |
|
|
|
/* |
|
* Use 5 bits less than the max cq entries, that should give us around |
|
* 32 entries per hash list if totally full and uniformly spread. |
|
*/ |
|
hash_bits = ilog2(p->cq_entries); |
|
hash_bits -= 5; |
|
if (hash_bits <= 0) |
|
hash_bits = 1; |
|
ctx->cancel_hash_bits = hash_bits; |
|
ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head), |
|
GFP_KERNEL); |
|
if (!ctx->cancel_hash) |
|
goto err; |
|
__hash_init(ctx->cancel_hash, 1U << hash_bits); |
|
|
|
if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free, |
|
PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) |
|
goto err; |
|
|
|
ctx->flags = p->flags; |
|
init_waitqueue_head(&ctx->sqo_sq_wait); |
|
INIT_LIST_HEAD(&ctx->sqd_list); |
|
init_waitqueue_head(&ctx->cq_wait); |
|
INIT_LIST_HEAD(&ctx->cq_overflow_list); |
|
init_completion(&ctx->ref_comp); |
|
xa_init_flags(&ctx->io_buffers, XA_FLAGS_ALLOC1); |
|
xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1); |
|
mutex_init(&ctx->uring_lock); |
|
init_waitqueue_head(&ctx->wait); |
|
spin_lock_init(&ctx->completion_lock); |
|
INIT_LIST_HEAD(&ctx->iopoll_list); |
|
INIT_LIST_HEAD(&ctx->defer_list); |
|
INIT_LIST_HEAD(&ctx->timeout_list); |
|
spin_lock_init(&ctx->inflight_lock); |
|
INIT_LIST_HEAD(&ctx->inflight_list); |
|
spin_lock_init(&ctx->rsrc_ref_lock); |
|
INIT_LIST_HEAD(&ctx->rsrc_ref_list); |
|
INIT_DELAYED_WORK(&ctx->rsrc_put_work, io_rsrc_put_work); |
|
init_llist_head(&ctx->rsrc_put_llist); |
|
INIT_LIST_HEAD(&ctx->tctx_list); |
|
INIT_LIST_HEAD(&ctx->submit_state.comp.free_list); |
|
INIT_LIST_HEAD(&ctx->submit_state.comp.locked_free_list); |
|
return ctx; |
|
err: |
|
kfree(ctx->cancel_hash); |
|
kfree(ctx); |
|
return NULL; |
|
} |
|
|
|
static bool req_need_defer(struct io_kiocb *req, u32 seq) |
|
{ |
|
if (unlikely(req->flags & REQ_F_IO_DRAIN)) { |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
return seq != ctx->cached_cq_tail |
|
+ READ_ONCE(ctx->cached_cq_overflow); |
|
} |
|
|
|
return false; |
|
} |
|
|
|
static void io_req_track_inflight(struct io_kiocb *req) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
if (!(req->flags & REQ_F_INFLIGHT)) { |
|
req->flags |= REQ_F_INFLIGHT; |
|
|
|
spin_lock_irq(&ctx->inflight_lock); |
|
list_add(&req->inflight_entry, &ctx->inflight_list); |
|
spin_unlock_irq(&ctx->inflight_lock); |
|
} |
|
} |
|
|
|
static void io_prep_async_work(struct io_kiocb *req) |
|
{ |
|
const struct io_op_def *def = &io_op_defs[req->opcode]; |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
if (!req->work.creds) |
|
req->work.creds = get_current_cred(); |
|
|
|
if (req->flags & REQ_F_FORCE_ASYNC) |
|
req->work.flags |= IO_WQ_WORK_CONCURRENT; |
|
|
|
if (req->flags & REQ_F_ISREG) { |
|
if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL)) |
|
io_wq_hash_work(&req->work, file_inode(req->file)); |
|
} else if (!req->file || !S_ISBLK(file_inode(req->file)->i_mode)) { |
|
if (def->unbound_nonreg_file) |
|
req->work.flags |= IO_WQ_WORK_UNBOUND; |
|
} |
|
} |
|
|
|
static void io_prep_async_link(struct io_kiocb *req) |
|
{ |
|
struct io_kiocb *cur; |
|
|
|
io_for_each_link(cur, req) |
|
io_prep_async_work(cur); |
|
} |
|
|
|
static void io_queue_async_work(struct io_kiocb *req) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct io_kiocb *link = io_prep_linked_timeout(req); |
|
struct io_uring_task *tctx = req->task->io_uring; |
|
|
|
BUG_ON(!tctx); |
|
BUG_ON(!tctx->io_wq); |
|
|
|
/* init ->work of the whole link before punting */ |
|
io_prep_async_link(req); |
|
trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req, |
|
&req->work, req->flags); |
|
io_wq_enqueue(tctx->io_wq, &req->work); |
|
if (link) |
|
io_queue_linked_timeout(link); |
|
} |
|
|
|
static void io_kill_timeout(struct io_kiocb *req, int status) |
|
{ |
|
struct io_timeout_data *io = req->async_data; |
|
int ret; |
|
|
|
ret = hrtimer_try_to_cancel(&io->timer); |
|
if (ret != -1) { |
|
atomic_set(&req->ctx->cq_timeouts, |
|
atomic_read(&req->ctx->cq_timeouts) + 1); |
|
list_del_init(&req->timeout.list); |
|
io_cqring_fill_event(req, status); |
|
io_put_req_deferred(req, 1); |
|
} |
|
} |
|
|
|
static void __io_queue_deferred(struct io_ring_ctx *ctx) |
|
{ |
|
do { |
|
struct io_defer_entry *de = list_first_entry(&ctx->defer_list, |
|
struct io_defer_entry, list); |
|
|
|
if (req_need_defer(de->req, de->seq)) |
|
break; |
|
list_del_init(&de->list); |
|
io_req_task_queue(de->req); |
|
kfree(de); |
|
} while (!list_empty(&ctx->defer_list)); |
|
} |
|
|
|
static void io_flush_timeouts(struct io_ring_ctx *ctx) |
|
{ |
|
u32 seq; |
|
|
|
if (list_empty(&ctx->timeout_list)) |
|
return; |
|
|
|
seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts); |
|
|
|
do { |
|
u32 events_needed, events_got; |
|
struct io_kiocb *req = list_first_entry(&ctx->timeout_list, |
|
struct io_kiocb, timeout.list); |
|
|
|
if (io_is_timeout_noseq(req)) |
|
break; |
|
|
|
/* |
|
* Since seq can easily wrap around over time, subtract |
|
* the last seq at which timeouts were flushed before comparing. |
|
* Assuming not more than 2^31-1 events have happened since, |
|
* these subtractions won't have wrapped, so we can check if |
|
* target is in [last_seq, current_seq] by comparing the two. |
|
*/ |
|
events_needed = req->timeout.target_seq - ctx->cq_last_tm_flush; |
|
events_got = seq - ctx->cq_last_tm_flush; |
|
if (events_got < events_needed) |
|
break; |
|
|
|
list_del_init(&req->timeout.list); |
|
io_kill_timeout(req, 0); |
|
} while (!list_empty(&ctx->timeout_list)); |
|
|
|
ctx->cq_last_tm_flush = seq; |
|
} |
|
|
|
static void io_commit_cqring(struct io_ring_ctx *ctx) |
|
{ |
|
io_flush_timeouts(ctx); |
|
|
|
/* order cqe stores with ring update */ |
|
smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail); |
|
|
|
if (unlikely(!list_empty(&ctx->defer_list))) |
|
__io_queue_deferred(ctx); |
|
} |
|
|
|
static inline bool io_sqring_full(struct io_ring_ctx *ctx) |
|
{ |
|
struct io_rings *r = ctx->rings; |
|
|
|
return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == r->sq_ring_entries; |
|
} |
|
|
|
static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx) |
|
{ |
|
return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head); |
|
} |
|
|
|
static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx) |
|
{ |
|
struct io_rings *rings = ctx->rings; |
|
unsigned tail; |
|
|
|
/* |
|
* writes to the cq entry need to come after reading head; the |
|
* control dependency is enough as we're using WRITE_ONCE to |
|
* fill the cq entry |
|
*/ |
|
if (__io_cqring_events(ctx) == rings->cq_ring_entries) |
|
return NULL; |
|
|
|
tail = ctx->cached_cq_tail++; |
|
return &rings->cqes[tail & ctx->cq_mask]; |
|
} |
|
|
|
static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx) |
|
{ |
|
if (!ctx->cq_ev_fd) |
|
return false; |
|
if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED) |
|
return false; |
|
if (!ctx->eventfd_async) |
|
return true; |
|
return io_wq_current_is_worker(); |
|
} |
|
|
|
static void io_cqring_ev_posted(struct io_ring_ctx *ctx) |
|
{ |
|
/* see waitqueue_active() comment */ |
|
smp_mb(); |
|
|
|
if (waitqueue_active(&ctx->wait)) |
|
wake_up(&ctx->wait); |
|
if (ctx->sq_data && waitqueue_active(&ctx->sq_data->wait)) |
|
wake_up(&ctx->sq_data->wait); |
|
if (io_should_trigger_evfd(ctx)) |
|
eventfd_signal(ctx->cq_ev_fd, 1); |
|
if (waitqueue_active(&ctx->cq_wait)) { |
|
wake_up_interruptible(&ctx->cq_wait); |
|
kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN); |
|
} |
|
} |
|
|
|
static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx) |
|
{ |
|
/* see waitqueue_active() comment */ |
|
smp_mb(); |
|
|
|
if (ctx->flags & IORING_SETUP_SQPOLL) { |
|
if (waitqueue_active(&ctx->wait)) |
|
wake_up(&ctx->wait); |
|
} |
|
if (io_should_trigger_evfd(ctx)) |
|
eventfd_signal(ctx->cq_ev_fd, 1); |
|
if (waitqueue_active(&ctx->cq_wait)) { |
|
wake_up_interruptible(&ctx->cq_wait); |
|
kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN); |
|
} |
|
} |
|
|
|
/* Returns true if there are no backlogged entries after the flush */ |
|
static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force, |
|
struct task_struct *tsk, |
|
struct files_struct *files) |
|
{ |
|
struct io_rings *rings = ctx->rings; |
|
struct io_kiocb *req, *tmp; |
|
struct io_uring_cqe *cqe; |
|
unsigned long flags; |
|
bool all_flushed, posted; |
|
LIST_HEAD(list); |
|
|
|
if (!force && __io_cqring_events(ctx) == rings->cq_ring_entries) |
|
return false; |
|
|
|
posted = false; |
|
spin_lock_irqsave(&ctx->completion_lock, flags); |
|
list_for_each_entry_safe(req, tmp, &ctx->cq_overflow_list, compl.list) { |
|
if (!io_match_task(req, tsk, files)) |
|
continue; |
|
|
|
cqe = io_get_cqring(ctx); |
|
if (!cqe && !force) |
|
break; |
|
|
|
list_move(&req->compl.list, &list); |
|
if (cqe) { |
|
WRITE_ONCE(cqe->user_data, req->user_data); |
|
WRITE_ONCE(cqe->res, req->result); |
|
WRITE_ONCE(cqe->flags, req->compl.cflags); |
|
} else { |
|
ctx->cached_cq_overflow++; |
|
WRITE_ONCE(ctx->rings->cq_overflow, |
|
ctx->cached_cq_overflow); |
|
} |
|
posted = true; |
|
} |
|
|
|
all_flushed = list_empty(&ctx->cq_overflow_list); |
|
if (all_flushed) { |
|
clear_bit(0, &ctx->sq_check_overflow); |
|
clear_bit(0, &ctx->cq_check_overflow); |
|
ctx->rings->sq_flags &= ~IORING_SQ_CQ_OVERFLOW; |
|
} |
|
|
|
if (posted) |
|
io_commit_cqring(ctx); |
|
spin_unlock_irqrestore(&ctx->completion_lock, flags); |
|
if (posted) |
|
io_cqring_ev_posted(ctx); |
|
|
|
while (!list_empty(&list)) { |
|
req = list_first_entry(&list, struct io_kiocb, compl.list); |
|
list_del(&req->compl.list); |
|
io_put_req(req); |
|
} |
|
|
|
return all_flushed; |
|
} |
|
|
|
static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force, |
|
struct task_struct *tsk, |
|
struct files_struct *files) |
|
{ |
|
bool ret = true; |
|
|
|
if (test_bit(0, &ctx->cq_check_overflow)) { |
|
/* iopoll syncs against uring_lock, not completion_lock */ |
|
if (ctx->flags & IORING_SETUP_IOPOLL) |
|
mutex_lock(&ctx->uring_lock); |
|
ret = __io_cqring_overflow_flush(ctx, force, tsk, files); |
|
if (ctx->flags & IORING_SETUP_IOPOLL) |
|
mutex_unlock(&ctx->uring_lock); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static void __io_cqring_fill_event(struct io_kiocb *req, long res, long cflags) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct io_uring_cqe *cqe; |
|
|
|
trace_io_uring_complete(ctx, req->user_data, res); |
|
|
|
/* |
|
* If we can't get a cq entry, userspace overflowed the |
|
* submission (by quite a lot). Increment the overflow count in |
|
* the ring. |
|
*/ |
|
cqe = io_get_cqring(ctx); |
|
if (likely(cqe)) { |
|
WRITE_ONCE(cqe->user_data, req->user_data); |
|
WRITE_ONCE(cqe->res, res); |
|
WRITE_ONCE(cqe->flags, cflags); |
|
} else if (ctx->cq_overflow_flushed || |
|
atomic_read(&req->task->io_uring->in_idle)) { |
|
/* |
|
* If we're in ring overflow flush mode, or in task cancel mode, |
|
* then we cannot store the request for later flushing, we need |
|
* to drop it on the floor. |
|
*/ |
|
ctx->cached_cq_overflow++; |
|
WRITE_ONCE(ctx->rings->cq_overflow, ctx->cached_cq_overflow); |
|
} else { |
|
if (list_empty(&ctx->cq_overflow_list)) { |
|
set_bit(0, &ctx->sq_check_overflow); |
|
set_bit(0, &ctx->cq_check_overflow); |
|
ctx->rings->sq_flags |= IORING_SQ_CQ_OVERFLOW; |
|
} |
|
io_clean_op(req); |
|
req->result = res; |
|
req->compl.cflags = cflags; |
|
refcount_inc(&req->refs); |
|
list_add_tail(&req->compl.list, &ctx->cq_overflow_list); |
|
} |
|
} |
|
|
|
static void io_cqring_fill_event(struct io_kiocb *req, long res) |
|
{ |
|
__io_cqring_fill_event(req, res, 0); |
|
} |
|
|
|
static void io_req_complete_post(struct io_kiocb *req, long res, |
|
unsigned int cflags) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&ctx->completion_lock, flags); |
|
__io_cqring_fill_event(req, res, cflags); |
|
/* |
|
* If we're the last reference to this request, add to our locked |
|
* free_list cache. |
|
*/ |
|
if (refcount_dec_and_test(&req->refs)) { |
|
struct io_comp_state *cs = &ctx->submit_state.comp; |
|
|
|
if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) { |
|
if (req->flags & (REQ_F_LINK_TIMEOUT | REQ_F_FAIL_LINK)) |
|
io_disarm_next(req); |
|
if (req->link) { |
|
io_req_task_queue(req->link); |
|
req->link = NULL; |
|
} |
|
} |
|
io_dismantle_req(req); |
|
io_put_task(req->task, 1); |
|
list_add(&req->compl.list, &cs->locked_free_list); |
|
cs->locked_free_nr++; |
|
} else { |
|
if (!percpu_ref_tryget(&ctx->refs)) |
|
req = NULL; |
|
} |
|
io_commit_cqring(ctx); |
|
spin_unlock_irqrestore(&ctx->completion_lock, flags); |
|
|
|
if (req) { |
|
io_cqring_ev_posted(ctx); |
|
percpu_ref_put(&ctx->refs); |
|
} |
|
} |
|
|
|
static void io_req_complete_state(struct io_kiocb *req, long res, |
|
unsigned int cflags) |
|
{ |
|
io_clean_op(req); |
|
req->result = res; |
|
req->compl.cflags = cflags; |
|
req->flags |= REQ_F_COMPLETE_INLINE; |
|
} |
|
|
|
static inline void __io_req_complete(struct io_kiocb *req, unsigned issue_flags, |
|
long res, unsigned cflags) |
|
{ |
|
if (issue_flags & IO_URING_F_COMPLETE_DEFER) |
|
io_req_complete_state(req, res, cflags); |
|
else |
|
io_req_complete_post(req, res, cflags); |
|
} |
|
|
|
static inline void io_req_complete(struct io_kiocb *req, long res) |
|
{ |
|
__io_req_complete(req, 0, res, 0); |
|
} |
|
|
|
static bool io_flush_cached_reqs(struct io_ring_ctx *ctx) |
|
{ |
|
struct io_submit_state *state = &ctx->submit_state; |
|
struct io_comp_state *cs = &state->comp; |
|
struct io_kiocb *req = NULL; |
|
|
|
/* |
|
* If we have more than a batch's worth of requests in our IRQ side |
|
* locked cache, grab the lock and move them over to our submission |
|
* side cache. |
|
*/ |
|
if (READ_ONCE(cs->locked_free_nr) > IO_COMPL_BATCH) { |
|
spin_lock_irq(&ctx->completion_lock); |
|
list_splice_init(&cs->locked_free_list, &cs->free_list); |
|
cs->locked_free_nr = 0; |
|
spin_unlock_irq(&ctx->completion_lock); |
|
} |
|
|
|
while (!list_empty(&cs->free_list)) { |
|
req = list_first_entry(&cs->free_list, struct io_kiocb, |
|
compl.list); |
|
list_del(&req->compl.list); |
|
state->reqs[state->free_reqs++] = req; |
|
if (state->free_reqs == ARRAY_SIZE(state->reqs)) |
|
break; |
|
} |
|
|
|
return req != NULL; |
|
} |
|
|
|
static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx) |
|
{ |
|
struct io_submit_state *state = &ctx->submit_state; |
|
|
|
BUILD_BUG_ON(IO_REQ_ALLOC_BATCH > ARRAY_SIZE(state->reqs)); |
|
|
|
if (!state->free_reqs) { |
|
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; |
|
int ret; |
|
|
|
if (io_flush_cached_reqs(ctx)) |
|
goto got_req; |
|
|
|
ret = kmem_cache_alloc_bulk(req_cachep, gfp, IO_REQ_ALLOC_BATCH, |
|
state->reqs); |
|
|
|
/* |
|
* Bulk alloc is all-or-nothing. If we fail to get a batch, |
|
* retry single alloc to be on the safe side. |
|
*/ |
|
if (unlikely(ret <= 0)) { |
|
state->reqs[0] = kmem_cache_alloc(req_cachep, gfp); |
|
if (!state->reqs[0]) |
|
return NULL; |
|
ret = 1; |
|
} |
|
state->free_reqs = ret; |
|
} |
|
got_req: |
|
state->free_reqs--; |
|
return state->reqs[state->free_reqs]; |
|
} |
|
|
|
static inline void io_put_file(struct io_kiocb *req, struct file *file, |
|
bool fixed) |
|
{ |
|
if (!fixed) |
|
fput(file); |
|
} |
|
|
|
static void io_dismantle_req(struct io_kiocb *req) |
|
{ |
|
io_clean_op(req); |
|
|
|
if (req->async_data) |
|
kfree(req->async_data); |
|
if (req->file) |
|
io_put_file(req, req->file, (req->flags & REQ_F_FIXED_FILE)); |
|
if (req->fixed_rsrc_refs) |
|
percpu_ref_put(req->fixed_rsrc_refs); |
|
if (req->work.creds) { |
|
put_cred(req->work.creds); |
|
req->work.creds = NULL; |
|
} |
|
|
|
if (req->flags & REQ_F_INFLIGHT) { |
|
struct io_ring_ctx *ctx = req->ctx; |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&ctx->inflight_lock, flags); |
|
list_del(&req->inflight_entry); |
|
spin_unlock_irqrestore(&ctx->inflight_lock, flags); |
|
req->flags &= ~REQ_F_INFLIGHT; |
|
} |
|
} |
|
|
|
/* must to be called somewhat shortly after putting a request */ |
|
static inline void io_put_task(struct task_struct *task, int nr) |
|
{ |
|
struct io_uring_task *tctx = task->io_uring; |
|
|
|
percpu_counter_sub(&tctx->inflight, nr); |
|
if (unlikely(atomic_read(&tctx->in_idle))) |
|
wake_up(&tctx->wait); |
|
put_task_struct_many(task, nr); |
|
} |
|
|
|
static void __io_free_req(struct io_kiocb *req) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
io_dismantle_req(req); |
|
io_put_task(req->task, 1); |
|
|
|
kmem_cache_free(req_cachep, req); |
|
percpu_ref_put(&ctx->refs); |
|
} |
|
|
|
static inline void io_remove_next_linked(struct io_kiocb *req) |
|
{ |
|
struct io_kiocb *nxt = req->link; |
|
|
|
req->link = nxt->link; |
|
nxt->link = NULL; |
|
} |
|
|
|
static bool io_kill_linked_timeout(struct io_kiocb *req) |
|
__must_hold(&req->ctx->completion_lock) |
|
{ |
|
struct io_kiocb *link = req->link; |
|
bool cancelled = false; |
|
|
|
/* |
|
* Can happen if a linked timeout fired and link had been like |
|
* req -> link t-out -> link t-out [-> ...] |
|
*/ |
|
if (link && (link->flags & REQ_F_LTIMEOUT_ACTIVE)) { |
|
struct io_timeout_data *io = link->async_data; |
|
int ret; |
|
|
|
io_remove_next_linked(req); |
|
link->timeout.head = NULL; |
|
ret = hrtimer_try_to_cancel(&io->timer); |
|
if (ret != -1) { |
|
io_cqring_fill_event(link, -ECANCELED); |
|
io_put_req_deferred(link, 1); |
|
cancelled = true; |
|
} |
|
} |
|
req->flags &= ~REQ_F_LINK_TIMEOUT; |
|
return cancelled; |
|
} |
|
|
|
static void io_fail_links(struct io_kiocb *req) |
|
__must_hold(&req->ctx->completion_lock) |
|
{ |
|
struct io_kiocb *nxt, *link = req->link; |
|
|
|
req->link = NULL; |
|
while (link) { |
|
nxt = link->link; |
|
link->link = NULL; |
|
|
|
trace_io_uring_fail_link(req, link); |
|
io_cqring_fill_event(link, -ECANCELED); |
|
io_put_req_deferred(link, 2); |
|
link = nxt; |
|
} |
|
} |
|
|
|
static bool io_disarm_next(struct io_kiocb *req) |
|
__must_hold(&req->ctx->completion_lock) |
|
{ |
|
bool posted = false; |
|
|
|
if (likely(req->flags & REQ_F_LINK_TIMEOUT)) |
|
posted = io_kill_linked_timeout(req); |
|
if (unlikely(req->flags & REQ_F_FAIL_LINK)) { |
|
posted |= (req->link != NULL); |
|
io_fail_links(req); |
|
} |
|
return posted; |
|
} |
|
|
|
static struct io_kiocb *__io_req_find_next(struct io_kiocb *req) |
|
{ |
|
struct io_kiocb *nxt; |
|
|
|
/* |
|
* If LINK is set, we have dependent requests in this chain. If we |
|
* didn't fail this request, queue the first one up, moving any other |
|
* dependencies to the next request. In case of failure, fail the rest |
|
* of the chain. |
|
*/ |
|
if (req->flags & (REQ_F_LINK_TIMEOUT | REQ_F_FAIL_LINK)) { |
|
struct io_ring_ctx *ctx = req->ctx; |
|
unsigned long flags; |
|
bool posted; |
|
|
|
spin_lock_irqsave(&ctx->completion_lock, flags); |
|
posted = io_disarm_next(req); |
|
if (posted) |
|
io_commit_cqring(req->ctx); |
|
spin_unlock_irqrestore(&ctx->completion_lock, flags); |
|
if (posted) |
|
io_cqring_ev_posted(ctx); |
|
} |
|
nxt = req->link; |
|
req->link = NULL; |
|
return nxt; |
|
} |
|
|
|
static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req) |
|
{ |
|
if (likely(!(req->flags & (REQ_F_LINK|REQ_F_HARDLINK)))) |
|
return NULL; |
|
return __io_req_find_next(req); |
|
} |
|
|
|
static void ctx_flush_and_put(struct io_ring_ctx *ctx) |
|
{ |
|
if (!ctx) |
|
return; |
|
if (ctx->submit_state.comp.nr) { |
|
mutex_lock(&ctx->uring_lock); |
|
io_submit_flush_completions(&ctx->submit_state.comp, ctx); |
|
mutex_unlock(&ctx->uring_lock); |
|
} |
|
percpu_ref_put(&ctx->refs); |
|
} |
|
|
|
static bool __tctx_task_work(struct io_uring_task *tctx) |
|
{ |
|
struct io_ring_ctx *ctx = NULL; |
|
struct io_wq_work_list list; |
|
struct io_wq_work_node *node; |
|
|
|
if (wq_list_empty(&tctx->task_list)) |
|
return false; |
|
|
|
spin_lock_irq(&tctx->task_lock); |
|
list = tctx->task_list; |
|
INIT_WQ_LIST(&tctx->task_list); |
|
spin_unlock_irq(&tctx->task_lock); |
|
|
|
node = list.first; |
|
while (node) { |
|
struct io_wq_work_node *next = node->next; |
|
struct io_kiocb *req; |
|
|
|
req = container_of(node, struct io_kiocb, io_task_work.node); |
|
if (req->ctx != ctx) { |
|
ctx_flush_and_put(ctx); |
|
ctx = req->ctx; |
|
percpu_ref_get(&ctx->refs); |
|
} |
|
|
|
req->task_work.func(&req->task_work); |
|
node = next; |
|
} |
|
|
|
ctx_flush_and_put(ctx); |
|
return list.first != NULL; |
|
} |
|
|
|
static void tctx_task_work(struct callback_head *cb) |
|
{ |
|
struct io_uring_task *tctx = container_of(cb, struct io_uring_task, task_work); |
|
|
|
clear_bit(0, &tctx->task_state); |
|
|
|
while (__tctx_task_work(tctx)) |
|
cond_resched(); |
|
} |
|
|
|
static int io_task_work_add(struct task_struct *tsk, struct io_kiocb *req, |
|
enum task_work_notify_mode notify) |
|
{ |
|
struct io_uring_task *tctx = tsk->io_uring; |
|
struct io_wq_work_node *node, *prev; |
|
unsigned long flags; |
|
int ret; |
|
|
|
WARN_ON_ONCE(!tctx); |
|
|
|
spin_lock_irqsave(&tctx->task_lock, flags); |
|
wq_list_add_tail(&req->io_task_work.node, &tctx->task_list); |
|
spin_unlock_irqrestore(&tctx->task_lock, flags); |
|
|
|
/* task_work already pending, we're done */ |
|
if (test_bit(0, &tctx->task_state) || |
|
test_and_set_bit(0, &tctx->task_state)) |
|
return 0; |
|
|
|
if (!task_work_add(tsk, &tctx->task_work, notify)) |
|
return 0; |
|
|
|
/* |
|
* Slow path - we failed, find and delete work. if the work is not |
|
* in the list, it got run and we're fine. |
|
*/ |
|
ret = 0; |
|
spin_lock_irqsave(&tctx->task_lock, flags); |
|
wq_list_for_each(node, prev, &tctx->task_list) { |
|
if (&req->io_task_work.node == node) { |
|
wq_list_del(&tctx->task_list, node, prev); |
|
ret = 1; |
|
break; |
|
} |
|
} |
|
spin_unlock_irqrestore(&tctx->task_lock, flags); |
|
clear_bit(0, &tctx->task_state); |
|
return ret; |
|
} |
|
|
|
static int io_req_task_work_add(struct io_kiocb *req) |
|
{ |
|
struct task_struct *tsk = req->task; |
|
struct io_ring_ctx *ctx = req->ctx; |
|
enum task_work_notify_mode notify; |
|
int ret; |
|
|
|
if (tsk->flags & PF_EXITING) |
|
return -ESRCH; |
|
|
|
/* |
|
* SQPOLL kernel thread doesn't need notification, just a wakeup. For |
|
* all other cases, use TWA_SIGNAL unconditionally to ensure we're |
|
* processing task_work. There's no reliable way to tell if TWA_RESUME |
|
* will do the job. |
|
*/ |
|
notify = TWA_NONE; |
|
if (!(ctx->flags & IORING_SETUP_SQPOLL)) |
|
notify = TWA_SIGNAL; |
|
|
|
ret = io_task_work_add(tsk, req, notify); |
|
if (!ret) |
|
wake_up_process(tsk); |
|
|
|
return ret; |
|
} |
|
|
|
static bool io_run_task_work_head(struct callback_head **work_head) |
|
{ |
|
struct callback_head *work, *next; |
|
bool executed = false; |
|
|
|
do { |
|
work = xchg(work_head, NULL); |
|
if (!work) |
|
break; |
|
|
|
do { |
|
next = work->next; |
|
work->func(work); |
|
work = next; |
|
cond_resched(); |
|
} while (work); |
|
executed = true; |
|
} while (1); |
|
|
|
return executed; |
|
} |
|
|
|
static void io_task_work_add_head(struct callback_head **work_head, |
|
struct callback_head *task_work) |
|
{ |
|
struct callback_head *head; |
|
|
|
do { |
|
head = READ_ONCE(*work_head); |
|
task_work->next = head; |
|
} while (cmpxchg(work_head, head, task_work) != head); |
|
} |
|
|
|
static void io_req_task_work_add_fallback(struct io_kiocb *req, |
|
task_work_func_t cb) |
|
{ |
|
init_task_work(&req->task_work, cb); |
|
io_task_work_add_head(&req->ctx->exit_task_work, &req->task_work); |
|
} |
|
|
|
static void __io_req_task_cancel(struct io_kiocb *req, int error) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
spin_lock_irq(&ctx->completion_lock); |
|
io_cqring_fill_event(req, error); |
|
io_commit_cqring(ctx); |
|
spin_unlock_irq(&ctx->completion_lock); |
|
|
|
io_cqring_ev_posted(ctx); |
|
req_set_fail_links(req); |
|
io_double_put_req(req); |
|
} |
|
|
|
static void io_req_task_cancel(struct callback_head *cb) |
|
{ |
|
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
mutex_lock(&ctx->uring_lock); |
|
__io_req_task_cancel(req, req->result); |
|
mutex_unlock(&ctx->uring_lock); |
|
percpu_ref_put(&ctx->refs); |
|
} |
|
|
|
static void __io_req_task_submit(struct io_kiocb *req) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
/* ctx stays valid until unlock, even if we drop all ours ctx->refs */ |
|
mutex_lock(&ctx->uring_lock); |
|
if (!(current->flags & PF_EXITING) && !current->in_execve) |
|
__io_queue_sqe(req); |
|
else |
|
__io_req_task_cancel(req, -EFAULT); |
|
mutex_unlock(&ctx->uring_lock); |
|
} |
|
|
|
static void io_req_task_submit(struct callback_head *cb) |
|
{ |
|
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); |
|
|
|
__io_req_task_submit(req); |
|
} |
|
|
|
static void io_req_task_queue(struct io_kiocb *req) |
|
{ |
|
int ret; |
|
|
|
req->task_work.func = io_req_task_submit; |
|
ret = io_req_task_work_add(req); |
|
if (unlikely(ret)) { |
|
req->result = -ECANCELED; |
|
percpu_ref_get(&req->ctx->refs); |
|
io_req_task_work_add_fallback(req, io_req_task_cancel); |
|
} |
|
} |
|
|
|
static void io_req_task_queue_fail(struct io_kiocb *req, int ret) |
|
{ |
|
percpu_ref_get(&req->ctx->refs); |
|
req->result = ret; |
|
req->task_work.func = io_req_task_cancel; |
|
|
|
if (unlikely(io_req_task_work_add(req))) |
|
io_req_task_work_add_fallback(req, io_req_task_cancel); |
|
} |
|
|
|
static inline void io_queue_next(struct io_kiocb *req) |
|
{ |
|
struct io_kiocb *nxt = io_req_find_next(req); |
|
|
|
if (nxt) |
|
io_req_task_queue(nxt); |
|
} |
|
|
|
static void io_free_req(struct io_kiocb *req) |
|
{ |
|
io_queue_next(req); |
|
__io_free_req(req); |
|
} |
|
|
|
struct req_batch { |
|
struct task_struct *task; |
|
int task_refs; |
|
int ctx_refs; |
|
}; |
|
|
|
static inline void io_init_req_batch(struct req_batch *rb) |
|
{ |
|
rb->task_refs = 0; |
|
rb->ctx_refs = 0; |
|
rb->task = NULL; |
|
} |
|
|
|
static void io_req_free_batch_finish(struct io_ring_ctx *ctx, |
|
struct req_batch *rb) |
|
{ |
|
if (rb->task) |
|
io_put_task(rb->task, rb->task_refs); |
|
if (rb->ctx_refs) |
|
percpu_ref_put_many(&ctx->refs, rb->ctx_refs); |
|
} |
|
|
|
static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req, |
|
struct io_submit_state *state) |
|
{ |
|
io_queue_next(req); |
|
|
|
if (req->task != rb->task) { |
|
if (rb->task) |
|
io_put_task(rb->task, rb->task_refs); |
|
rb->task = req->task; |
|
rb->task_refs = 0; |
|
} |
|
rb->task_refs++; |
|
rb->ctx_refs++; |
|
|
|
io_dismantle_req(req); |
|
if (state->free_reqs != ARRAY_SIZE(state->reqs)) |
|
state->reqs[state->free_reqs++] = req; |
|
else |
|
list_add(&req->compl.list, &state->comp.free_list); |
|
} |
|
|
|
static void io_submit_flush_completions(struct io_comp_state *cs, |
|
struct io_ring_ctx *ctx) |
|
{ |
|
int i, nr = cs->nr; |
|
struct io_kiocb *req; |
|
struct req_batch rb; |
|
|
|
io_init_req_batch(&rb); |
|
spin_lock_irq(&ctx->completion_lock); |
|
for (i = 0; i < nr; i++) { |
|
req = cs->reqs[i]; |
|
__io_cqring_fill_event(req, req->result, req->compl.cflags); |
|
} |
|
io_commit_cqring(ctx); |
|
spin_unlock_irq(&ctx->completion_lock); |
|
|
|
io_cqring_ev_posted(ctx); |
|
for (i = 0; i < nr; i++) { |
|
req = cs->reqs[i]; |
|
|
|
/* submission and completion refs */ |
|
if (refcount_sub_and_test(2, &req->refs)) |
|
io_req_free_batch(&rb, req, &ctx->submit_state); |
|
} |
|
|
|
io_req_free_batch_finish(ctx, &rb); |
|
cs->nr = 0; |
|
} |
|
|
|
/* |
|
* Drop reference to request, return next in chain (if there is one) if this |
|
* was the last reference to this request. |
|
*/ |
|
static struct io_kiocb *io_put_req_find_next(struct io_kiocb *req) |
|
{ |
|
struct io_kiocb *nxt = NULL; |
|
|
|
if (refcount_dec_and_test(&req->refs)) { |
|
nxt = io_req_find_next(req); |
|
__io_free_req(req); |
|
} |
|
return nxt; |
|
} |
|
|
|
static void io_put_req(struct io_kiocb *req) |
|
{ |
|
if (refcount_dec_and_test(&req->refs)) |
|
io_free_req(req); |
|
} |
|
|
|
static void io_put_req_deferred_cb(struct callback_head *cb) |
|
{ |
|
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); |
|
|
|
io_free_req(req); |
|
} |
|
|
|
static void io_free_req_deferred(struct io_kiocb *req) |
|
{ |
|
int ret; |
|
|
|
req->task_work.func = io_put_req_deferred_cb; |
|
ret = io_req_task_work_add(req); |
|
if (unlikely(ret)) |
|
io_req_task_work_add_fallback(req, io_put_req_deferred_cb); |
|
} |
|
|
|
static inline void io_put_req_deferred(struct io_kiocb *req, int refs) |
|
{ |
|
if (refcount_sub_and_test(refs, &req->refs)) |
|
io_free_req_deferred(req); |
|
} |
|
|
|
static void io_double_put_req(struct io_kiocb *req) |
|
{ |
|
/* drop both submit and complete references */ |
|
if (refcount_sub_and_test(2, &req->refs)) |
|
io_free_req(req); |
|
} |
|
|
|
static unsigned io_cqring_events(struct io_ring_ctx *ctx) |
|
{ |
|
/* See comment at the top of this file */ |
|
smp_rmb(); |
|
return __io_cqring_events(ctx); |
|
} |
|
|
|
static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx) |
|
{ |
|
struct io_rings *rings = ctx->rings; |
|
|
|
/* make sure SQ entry isn't read before tail */ |
|
return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head; |
|
} |
|
|
|
static unsigned int io_put_kbuf(struct io_kiocb *req, struct io_buffer *kbuf) |
|
{ |
|
unsigned int cflags; |
|
|
|
cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT; |
|
cflags |= IORING_CQE_F_BUFFER; |
|
req->flags &= ~REQ_F_BUFFER_SELECTED; |
|
kfree(kbuf); |
|
return cflags; |
|
} |
|
|
|
static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req) |
|
{ |
|
struct io_buffer *kbuf; |
|
|
|
kbuf = (struct io_buffer *) (unsigned long) req->rw.addr; |
|
return io_put_kbuf(req, kbuf); |
|
} |
|
|
|
static inline bool io_run_task_work(void) |
|
{ |
|
/* |
|
* Not safe to run on exiting task, and the task_work handling will |
|
* not add work to such a task. |
|
*/ |
|
if (unlikely(current->flags & PF_EXITING)) |
|
return false; |
|
if (current->task_works) { |
|
__set_current_state(TASK_RUNNING); |
|
task_work_run(); |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
/* |
|
* Find and free completed poll iocbs |
|
*/ |
|
static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, |
|
struct list_head *done) |
|
{ |
|
struct req_batch rb; |
|
struct io_kiocb *req; |
|
|
|
/* order with ->result store in io_complete_rw_iopoll() */ |
|
smp_rmb(); |
|
|
|
io_init_req_batch(&rb); |
|
while (!list_empty(done)) { |
|
int cflags = 0; |
|
|
|
req = list_first_entry(done, struct io_kiocb, inflight_entry); |
|
list_del(&req->inflight_entry); |
|
|
|
if (READ_ONCE(req->result) == -EAGAIN) { |
|
req->iopoll_completed = 0; |
|
if (io_rw_reissue(req)) |
|
continue; |
|
} |
|
|
|
if (req->flags & REQ_F_BUFFER_SELECTED) |
|
cflags = io_put_rw_kbuf(req); |
|
|
|
__io_cqring_fill_event(req, req->result, cflags); |
|
(*nr_events)++; |
|
|
|
if (refcount_dec_and_test(&req->refs)) |
|
io_req_free_batch(&rb, req, &ctx->submit_state); |
|
} |
|
|
|
io_commit_cqring(ctx); |
|
io_cqring_ev_posted_iopoll(ctx); |
|
io_req_free_batch_finish(ctx, &rb); |
|
} |
|
|
|
static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, |
|
long min) |
|
{ |
|
struct io_kiocb *req, *tmp; |
|
LIST_HEAD(done); |
|
bool spin; |
|
int ret; |
|
|
|
/* |
|
* Only spin for completions if we don't have multiple devices hanging |
|
* off our complete list, and we're under the requested amount. |
|
*/ |
|
spin = !ctx->poll_multi_file && *nr_events < min; |
|
|
|
ret = 0; |
|
list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, inflight_entry) { |
|
struct kiocb *kiocb = &req->rw.kiocb; |
|
|
|
/* |
|
* Move completed and retryable entries to our local lists. |
|
* If we find a request that requires polling, break out |
|
* and complete those lists first, if we have entries there. |
|
*/ |
|
if (READ_ONCE(req->iopoll_completed)) { |
|
list_move_tail(&req->inflight_entry, &done); |
|
continue; |
|
} |
|
if (!list_empty(&done)) |
|
break; |
|
|
|
ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin); |
|
if (ret < 0) |
|
break; |
|
|
|
/* iopoll may have completed current req */ |
|
if (READ_ONCE(req->iopoll_completed)) |
|
list_move_tail(&req->inflight_entry, &done); |
|
|
|
if (ret && spin) |
|
spin = false; |
|
ret = 0; |
|
} |
|
|
|
if (!list_empty(&done)) |
|
io_iopoll_complete(ctx, nr_events, &done); |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* Poll for a minimum of 'min' events. Note that if min == 0 we consider that a |
|
* non-spinning poll check - we'll still enter the driver poll loop, but only |
|
* as a non-spinning completion check. |
|
*/ |
|
static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events, |
|
long min) |
|
{ |
|
while (!list_empty(&ctx->iopoll_list) && !need_resched()) { |
|
int ret; |
|
|
|
ret = io_do_iopoll(ctx, nr_events, min); |
|
if (ret < 0) |
|
return ret; |
|
if (*nr_events >= min) |
|
return 0; |
|
} |
|
|
|
return 1; |
|
} |
|
|
|
/* |
|
* We can't just wait for polled events to come to us, we have to actively |
|
* find and complete them. |
|
*/ |
|
static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx) |
|
{ |
|
if (!(ctx->flags & IORING_SETUP_IOPOLL)) |
|
return; |
|
|
|
mutex_lock(&ctx->uring_lock); |
|
while (!list_empty(&ctx->iopoll_list)) { |
|
unsigned int nr_events = 0; |
|
|
|
io_do_iopoll(ctx, &nr_events, 0); |
|
|
|
/* let it sleep and repeat later if can't complete a request */ |
|
if (nr_events == 0) |
|
break; |
|
/* |
|
* Ensure we allow local-to-the-cpu processing to take place, |
|
* in this case we need to ensure that we reap all events. |
|
* Also let task_work, etc. to progress by releasing the mutex |
|
*/ |
|
if (need_resched()) { |
|
mutex_unlock(&ctx->uring_lock); |
|
cond_resched(); |
|
mutex_lock(&ctx->uring_lock); |
|
} |
|
} |
|
mutex_unlock(&ctx->uring_lock); |
|
} |
|
|
|
static int io_iopoll_check(struct io_ring_ctx *ctx, long min) |
|
{ |
|
unsigned int nr_events = 0; |
|
int iters = 0, ret = 0; |
|
|
|
/* |
|
* We disallow the app entering submit/complete with polling, but we |
|
* still need to lock the ring to prevent racing with polled issue |
|
* that got punted to a workqueue. |
|
*/ |
|
mutex_lock(&ctx->uring_lock); |
|
do { |
|
/* |
|
* Don't enter poll loop if we already have events pending. |
|
* If we do, we can potentially be spinning for commands that |
|
* already triggered a CQE (eg in error). |
|
*/ |
|
if (test_bit(0, &ctx->cq_check_overflow)) |
|
__io_cqring_overflow_flush(ctx, false, NULL, NULL); |
|
if (io_cqring_events(ctx)) |
|
break; |
|
|
|
/* |
|
* If a submit got punted to a workqueue, we can have the |
|
* application entering polling for a command before it gets |
|
* issued. That app will hold the uring_lock for the duration |
|
* of the poll right here, so we need to take a breather every |
|
* now and then to ensure that the issue has a chance to add |
|
* the poll to the issued list. Otherwise we can spin here |
|
* forever, while the workqueue is stuck trying to acquire the |
|
* very same mutex. |
|
*/ |
|
if (!(++iters & 7)) { |
|
mutex_unlock(&ctx->uring_lock); |
|
io_run_task_work(); |
|
mutex_lock(&ctx->uring_lock); |
|
} |
|
|
|
ret = io_iopoll_getevents(ctx, &nr_events, min); |
|
if (ret <= 0) |
|
break; |
|
ret = 0; |
|
} while (min && !nr_events && !need_resched()); |
|
|
|
mutex_unlock(&ctx->uring_lock); |
|
return ret; |
|
} |
|
|
|
static void kiocb_end_write(struct io_kiocb *req) |
|
{ |
|
/* |
|
* Tell lockdep we inherited freeze protection from submission |
|
* thread. |
|
*/ |
|
if (req->flags & REQ_F_ISREG) { |
|
struct inode *inode = file_inode(req->file); |
|
|
|
__sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE); |
|
} |
|
file_end_write(req->file); |
|
} |
|
|
|
#ifdef CONFIG_BLOCK |
|
static bool io_resubmit_prep(struct io_kiocb *req) |
|
{ |
|
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; |
|
int rw, ret; |
|
struct iov_iter iter; |
|
|
|
/* already prepared */ |
|
if (req->async_data) |
|
return true; |
|
|
|
switch (req->opcode) { |
|
case IORING_OP_READV: |
|
case IORING_OP_READ_FIXED: |
|
case IORING_OP_READ: |
|
rw = READ; |
|
break; |
|
case IORING_OP_WRITEV: |
|
case IORING_OP_WRITE_FIXED: |
|
case IORING_OP_WRITE: |
|
rw = WRITE; |
|
break; |
|
default: |
|
printk_once(KERN_WARNING "io_uring: bad opcode in resubmit %d\n", |
|
req->opcode); |
|
return false; |
|
} |
|
|
|
ret = io_import_iovec(rw, req, &iovec, &iter, false); |
|
if (ret < 0) |
|
return false; |
|
return !io_setup_async_rw(req, iovec, inline_vecs, &iter, false); |
|
} |
|
|
|
static bool io_rw_should_reissue(struct io_kiocb *req) |
|
{ |
|
umode_t mode = file_inode(req->file)->i_mode; |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
if (!S_ISBLK(mode) && !S_ISREG(mode)) |
|
return false; |
|
if ((req->flags & REQ_F_NOWAIT) || (io_wq_current_is_worker() && |
|
!(ctx->flags & IORING_SETUP_IOPOLL))) |
|
return false; |
|
/* |
|
* If ref is dying, we might be running poll reap from the exit work. |
|
* Don't attempt to reissue from that path, just let it fail with |
|
* -EAGAIN. |
|
*/ |
|
if (percpu_ref_is_dying(&ctx->refs)) |
|
return false; |
|
return true; |
|
} |
|
#else |
|
static bool io_rw_should_reissue(struct io_kiocb *req) |
|
{ |
|
return false; |
|
} |
|
#endif |
|
|
|
static bool io_rw_reissue(struct io_kiocb *req) |
|
{ |
|
#ifdef CONFIG_BLOCK |
|
if (!io_rw_should_reissue(req)) |
|
return false; |
|
|
|
lockdep_assert_held(&req->ctx->uring_lock); |
|
|
|
if (io_resubmit_prep(req)) { |
|
refcount_inc(&req->refs); |
|
io_queue_async_work(req); |
|
return true; |
|
} |
|
req_set_fail_links(req); |
|
#endif |
|
return false; |
|
} |
|
|
|
static void __io_complete_rw(struct io_kiocb *req, long res, long res2, |
|
unsigned int issue_flags) |
|
{ |
|
int cflags = 0; |
|
|
|
if (req->rw.kiocb.ki_flags & IOCB_WRITE) |
|
kiocb_end_write(req); |
|
if ((res == -EAGAIN || res == -EOPNOTSUPP) && io_rw_should_reissue(req)) { |
|
req->flags |= REQ_F_REISSUE; |
|
return; |
|
} |
|
if (res != req->result) |
|
req_set_fail_links(req); |
|
if (req->flags & REQ_F_BUFFER_SELECTED) |
|
cflags = io_put_rw_kbuf(req); |
|
__io_req_complete(req, issue_flags, res, cflags); |
|
} |
|
|
|
static void io_complete_rw(struct kiocb *kiocb, long res, long res2) |
|
{ |
|
struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); |
|
|
|
__io_complete_rw(req, res, res2, 0); |
|
} |
|
|
|
static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2) |
|
{ |
|
struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); |
|
|
|
#ifdef CONFIG_BLOCK |
|
/* Rewind iter, if we have one. iopoll path resubmits as usual */ |
|
if (res == -EAGAIN && io_rw_should_reissue(req)) { |
|
struct io_async_rw *rw = req->async_data; |
|
|
|
if (rw) |
|
iov_iter_revert(&rw->iter, |
|
req->result - iov_iter_count(&rw->iter)); |
|
else if (!io_resubmit_prep(req)) |
|
res = -EIO; |
|
} |
|
#endif |
|
|
|
if (kiocb->ki_flags & IOCB_WRITE) |
|
kiocb_end_write(req); |
|
|
|
if (res != -EAGAIN && res != req->result) |
|
req_set_fail_links(req); |
|
|
|
WRITE_ONCE(req->result, res); |
|
/* order with io_poll_complete() checking ->result */ |
|
smp_wmb(); |
|
WRITE_ONCE(req->iopoll_completed, 1); |
|
} |
|
|
|
/* |
|
* After the iocb has been issued, it's safe to be found on the poll list. |
|
* Adding the kiocb to the list AFTER submission ensures that we don't |
|
* find it from a io_iopoll_getevents() thread before the issuer is done |
|
* accessing the kiocb cookie. |
|
*/ |
|
static void io_iopoll_req_issued(struct io_kiocb *req, bool in_async) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
/* |
|
* Track whether we have multiple files in our lists. This will impact |
|
* how we do polling eventually, not spinning if we're on potentially |
|
* different devices. |
|
*/ |
|
if (list_empty(&ctx->iopoll_list)) { |
|
ctx->poll_multi_file = false; |
|
} else if (!ctx->poll_multi_file) { |
|
struct io_kiocb *list_req; |
|
|
|
list_req = list_first_entry(&ctx->iopoll_list, struct io_kiocb, |
|
inflight_entry); |
|
if (list_req->file != req->file) |
|
ctx->poll_multi_file = true; |
|
} |
|
|
|
/* |
|
* For fast devices, IO may have already completed. If it has, add |
|
* it to the front so we find it first. |
|
*/ |
|
if (READ_ONCE(req->iopoll_completed)) |
|
list_add(&req->inflight_entry, &ctx->iopoll_list); |
|
else |
|
list_add_tail(&req->inflight_entry, &ctx->iopoll_list); |
|
|
|
/* |
|
* If IORING_SETUP_SQPOLL is enabled, sqes are either handled in sq thread |
|
* task context or in io worker task context. If current task context is |
|
* sq thread, we don't need to check whether should wake up sq thread. |
|
*/ |
|
if (in_async && (ctx->flags & IORING_SETUP_SQPOLL) && |
|
wq_has_sleeper(&ctx->sq_data->wait)) |
|
wake_up(&ctx->sq_data->wait); |
|
} |
|
|
|
static inline void io_state_file_put(struct io_submit_state *state) |
|
{ |
|
if (state->file_refs) { |
|
fput_many(state->file, state->file_refs); |
|
state->file_refs = 0; |
|
} |
|
} |
|
|
|
/* |
|
* Get as many references to a file as we have IOs left in this submission, |
|
* assuming most submissions are for one file, or at least that each file |
|
* has more than one submission. |
|
*/ |
|
static struct file *__io_file_get(struct io_submit_state *state, int fd) |
|
{ |
|
if (!state) |
|
return fget(fd); |
|
|
|
if (state->file_refs) { |
|
if (state->fd == fd) { |
|
state->file_refs--; |
|
return state->file; |
|
} |
|
io_state_file_put(state); |
|
} |
|
state->file = fget_many(fd, state->ios_left); |
|
if (unlikely(!state->file)) |
|
return NULL; |
|
|
|
state->fd = fd; |
|
state->file_refs = state->ios_left - 1; |
|
return state->file; |
|
} |
|
|
|
static bool io_bdev_nowait(struct block_device *bdev) |
|
{ |
|
return !bdev || blk_queue_nowait(bdev_get_queue(bdev)); |
|
} |
|
|
|
/* |
|
* If we tracked the file through the SCM inflight mechanism, we could support |
|
* any file. For now, just ensure that anything potentially problematic is done |
|
* inline. |
|
*/ |
|
static bool io_file_supports_async(struct file *file, int rw) |
|
{ |
|
umode_t mode = file_inode(file)->i_mode; |
|
|
|
if (S_ISBLK(mode)) { |
|
if (IS_ENABLED(CONFIG_BLOCK) && |
|
io_bdev_nowait(I_BDEV(file->f_mapping->host))) |
|
return true; |
|
return false; |
|
} |
|
if (S_ISCHR(mode) || S_ISSOCK(mode)) |
|
return true; |
|
if (S_ISREG(mode)) { |
|
if (IS_ENABLED(CONFIG_BLOCK) && |
|
io_bdev_nowait(file->f_inode->i_sb->s_bdev) && |
|
file->f_op != &io_uring_fops) |
|
return true; |
|
return false; |
|
} |
|
|
|
/* any ->read/write should understand O_NONBLOCK */ |
|
if (file->f_flags & O_NONBLOCK) |
|
return true; |
|
|
|
if (!(file->f_mode & FMODE_NOWAIT)) |
|
return false; |
|
|
|
if (rw == READ) |
|
return file->f_op->read_iter != NULL; |
|
|
|
return file->f_op->write_iter != NULL; |
|
} |
|
|
|
static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct kiocb *kiocb = &req->rw.kiocb; |
|
struct file *file = req->file; |
|
unsigned ioprio; |
|
int ret; |
|
|
|
if (S_ISREG(file_inode(file)->i_mode)) |
|
req->flags |= REQ_F_ISREG; |
|
|
|
kiocb->ki_pos = READ_ONCE(sqe->off); |
|
if (kiocb->ki_pos == -1 && !(file->f_mode & FMODE_STREAM)) { |
|
req->flags |= REQ_F_CUR_POS; |
|
kiocb->ki_pos = file->f_pos; |
|
} |
|
kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp)); |
|
kiocb->ki_flags = iocb_flags(kiocb->ki_filp); |
|
ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags)); |
|
if (unlikely(ret)) |
|
return ret; |
|
|
|
/* don't allow async punt for O_NONBLOCK or RWF_NOWAIT */ |
|
if ((kiocb->ki_flags & IOCB_NOWAIT) || (file->f_flags & O_NONBLOCK)) |
|
req->flags |= REQ_F_NOWAIT; |
|
|
|
ioprio = READ_ONCE(sqe->ioprio); |
|
if (ioprio) { |
|
ret = ioprio_check_cap(ioprio); |
|
if (ret) |
|
return ret; |
|
|
|
kiocb->ki_ioprio = ioprio; |
|
} else |
|
kiocb->ki_ioprio = get_current_ioprio(); |
|
|
|
if (ctx->flags & IORING_SETUP_IOPOLL) { |
|
if (!(kiocb->ki_flags & IOCB_DIRECT) || |
|
!kiocb->ki_filp->f_op->iopoll) |
|
return -EOPNOTSUPP; |
|
|
|
kiocb->ki_flags |= IOCB_HIPRI; |
|
kiocb->ki_complete = io_complete_rw_iopoll; |
|
req->iopoll_completed = 0; |
|
} else { |
|
if (kiocb->ki_flags & IOCB_HIPRI) |
|
return -EINVAL; |
|
kiocb->ki_complete = io_complete_rw; |
|
} |
|
|
|
req->rw.addr = READ_ONCE(sqe->addr); |
|
req->rw.len = READ_ONCE(sqe->len); |
|
req->buf_index = READ_ONCE(sqe->buf_index); |
|
return 0; |
|
} |
|
|
|
static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) |
|
{ |
|
switch (ret) { |
|
case -EIOCBQUEUED: |
|
break; |
|
case -ERESTARTSYS: |
|
case -ERESTARTNOINTR: |
|
case -ERESTARTNOHAND: |
|
case -ERESTART_RESTARTBLOCK: |
|
/* |
|
* We can't just restart the syscall, since previously |
|
* submitted sqes may already be in progress. Just fail this |
|
* IO with EINTR. |
|
*/ |
|
ret = -EINTR; |
|
fallthrough; |
|
default: |
|
kiocb->ki_complete(kiocb, ret, 0); |
|
} |
|
} |
|
|
|
static void kiocb_done(struct kiocb *kiocb, ssize_t ret, |
|
unsigned int issue_flags) |
|
{ |
|
struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); |
|
struct io_async_rw *io = req->async_data; |
|
bool check_reissue = kiocb->ki_complete == io_complete_rw; |
|
|
|
/* add previously done IO, if any */ |
|
if (io && io->bytes_done > 0) { |
|
if (ret < 0) |
|
ret = io->bytes_done; |
|
else |
|
ret += io->bytes_done; |
|
} |
|
|
|
if (req->flags & REQ_F_CUR_POS) |
|
req->file->f_pos = kiocb->ki_pos; |
|
if (ret >= 0 && kiocb->ki_complete == io_complete_rw) |
|
__io_complete_rw(req, ret, 0, issue_flags); |
|
else |
|
io_rw_done(kiocb, ret); |
|
|
|
if (check_reissue && req->flags & REQ_F_REISSUE) { |
|
req->flags &= ~REQ_F_REISSUE; |
|
if (!io_rw_reissue(req)) { |
|
int cflags = 0; |
|
|
|
req_set_fail_links(req); |
|
if (req->flags & REQ_F_BUFFER_SELECTED) |
|
cflags = io_put_rw_kbuf(req); |
|
__io_req_complete(req, issue_flags, ret, cflags); |
|
} |
|
} |
|
} |
|
|
|
static int io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
size_t len = req->rw.len; |
|
struct io_mapped_ubuf *imu; |
|
u16 index, buf_index = req->buf_index; |
|
size_t offset; |
|
u64 buf_addr; |
|
|
|
if (unlikely(buf_index >= ctx->nr_user_bufs)) |
|
return -EFAULT; |
|
index = array_index_nospec(buf_index, ctx->nr_user_bufs); |
|
imu = &ctx->user_bufs[index]; |
|
buf_addr = req->rw.addr; |
|
|
|
/* overflow */ |
|
if (buf_addr + len < buf_addr) |
|
return -EFAULT; |
|
/* not inside the mapped region */ |
|
if (buf_addr < imu->ubuf || buf_addr + len > imu->ubuf + imu->len) |
|
return -EFAULT; |
|
|
|
/* |
|
* May not be a start of buffer, set size appropriately |
|
* and advance us to the beginning. |
|
*/ |
|
offset = buf_addr - imu->ubuf; |
|
iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len); |
|
|
|
if (offset) { |
|
/* |
|
* Don't use iov_iter_advance() here, as it's really slow for |
|
* using the latter parts of a big fixed buffer - it iterates |
|
* over each segment manually. We can cheat a bit here, because |
|
* we know that: |
|
* |
|
* 1) it's a BVEC iter, we set it up |
|
* 2) all bvecs are PAGE_SIZE in size, except potentially the |
|
* first and last bvec |
|
* |
|
* So just find our index, and adjust the iterator afterwards. |
|
* If the offset is within the first bvec (or the whole first |
|
* bvec, just use iov_iter_advance(). This makes it easier |
|
* since we can just skip the first segment, which may not |
|
* be PAGE_SIZE aligned. |
|
*/ |
|
const struct bio_vec *bvec = imu->bvec; |
|
|
|
if (offset <= bvec->bv_len) { |
|
iov_iter_advance(iter, offset); |
|
} else { |
|
unsigned long seg_skip; |
|
|
|
/* skip first vec */ |
|
offset -= bvec->bv_len; |
|
seg_skip = 1 + (offset >> PAGE_SHIFT); |
|
|
|
iter->bvec = bvec + seg_skip; |
|
iter->nr_segs -= seg_skip; |
|
iter->count -= bvec->bv_len + offset; |
|
iter->iov_offset = offset & ~PAGE_MASK; |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock) |
|
{ |
|
if (needs_lock) |
|
mutex_unlock(&ctx->uring_lock); |
|
} |
|
|
|
static void io_ring_submit_lock(struct io_ring_ctx *ctx, bool needs_lock) |
|
{ |
|
/* |
|
* "Normal" inline submissions always hold the uring_lock, since we |
|
* grab it from the system call. Same is true for the SQPOLL offload. |
|
* The only exception is when we've detached the request and issue it |
|
* from an async worker thread, grab the lock for that case. |
|
*/ |
|
if (needs_lock) |
|
mutex_lock(&ctx->uring_lock); |
|
} |
|
|
|
static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len, |
|
int bgid, struct io_buffer *kbuf, |
|
bool needs_lock) |
|
{ |
|
struct io_buffer *head; |
|
|
|
if (req->flags & REQ_F_BUFFER_SELECTED) |
|
return kbuf; |
|
|
|
io_ring_submit_lock(req->ctx, needs_lock); |
|
|
|
lockdep_assert_held(&req->ctx->uring_lock); |
|
|
|
head = xa_load(&req->ctx->io_buffers, bgid); |
|
if (head) { |
|
if (!list_empty(&head->list)) { |
|
kbuf = list_last_entry(&head->list, struct io_buffer, |
|
list); |
|
list_del(&kbuf->list); |
|
} else { |
|
kbuf = head; |
|
xa_erase(&req->ctx->io_buffers, bgid); |
|
} |
|
if (*len > kbuf->len) |
|
*len = kbuf->len; |
|
} else { |
|
kbuf = ERR_PTR(-ENOBUFS); |
|
} |
|
|
|
io_ring_submit_unlock(req->ctx, needs_lock); |
|
|
|
return kbuf; |
|
} |
|
|
|
static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len, |
|
bool needs_lock) |
|
{ |
|
struct io_buffer *kbuf; |
|
u16 bgid; |
|
|
|
kbuf = (struct io_buffer *) (unsigned long) req->rw.addr; |
|
bgid = req->buf_index; |
|
kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock); |
|
if (IS_ERR(kbuf)) |
|
return kbuf; |
|
req->rw.addr = (u64) (unsigned long) kbuf; |
|
req->flags |= REQ_F_BUFFER_SELECTED; |
|
return u64_to_user_ptr(kbuf->addr); |
|
} |
|
|
|
#ifdef CONFIG_COMPAT |
|
static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov, |
|
bool needs_lock) |
|
{ |
|
struct compat_iovec __user *uiov; |
|
compat_ssize_t clen; |
|
void __user *buf; |
|
ssize_t len; |
|
|
|
uiov = u64_to_user_ptr(req->rw.addr); |
|
if (!access_ok(uiov, sizeof(*uiov))) |
|
return -EFAULT; |
|
if (__get_user(clen, &uiov->iov_len)) |
|
return -EFAULT; |
|
if (clen < 0) |
|
return -EINVAL; |
|
|
|
len = clen; |
|
buf = io_rw_buffer_select(req, &len, needs_lock); |
|
if (IS_ERR(buf)) |
|
return PTR_ERR(buf); |
|
iov[0].iov_base = buf; |
|
iov[0].iov_len = (compat_size_t) len; |
|
return 0; |
|
} |
|
#endif |
|
|
|
static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov, |
|
bool needs_lock) |
|
{ |
|
struct iovec __user *uiov = u64_to_user_ptr(req->rw.addr); |
|
void __user *buf; |
|
ssize_t len; |
|
|
|
if (copy_from_user(iov, uiov, sizeof(*uiov))) |
|
return -EFAULT; |
|
|
|
len = iov[0].iov_len; |
|
if (len < 0) |
|
return -EINVAL; |
|
buf = io_rw_buffer_select(req, &len, needs_lock); |
|
if (IS_ERR(buf)) |
|
return PTR_ERR(buf); |
|
iov[0].iov_base = buf; |
|
iov[0].iov_len = len; |
|
return 0; |
|
} |
|
|
|
static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov, |
|
bool needs_lock) |
|
{ |
|
if (req->flags & REQ_F_BUFFER_SELECTED) { |
|
struct io_buffer *kbuf; |
|
|
|
kbuf = (struct io_buffer *) (unsigned long) req->rw.addr; |
|
iov[0].iov_base = u64_to_user_ptr(kbuf->addr); |
|
iov[0].iov_len = kbuf->len; |
|
return 0; |
|
} |
|
if (req->rw.len != 1) |
|
return -EINVAL; |
|
|
|
#ifdef CONFIG_COMPAT |
|
if (req->ctx->compat) |
|
return io_compat_import(req, iov, needs_lock); |
|
#endif |
|
|
|
return __io_iov_buffer_select(req, iov, needs_lock); |
|
} |
|
|
|
static int io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec, |
|
struct iov_iter *iter, bool needs_lock) |
|
{ |
|
void __user *buf = u64_to_user_ptr(req->rw.addr); |
|
size_t sqe_len = req->rw.len; |
|
u8 opcode = req->opcode; |
|
ssize_t ret; |
|
|
|
if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) { |
|
*iovec = NULL; |
|
return io_import_fixed(req, rw, iter); |
|
} |
|
|
|
/* buffer index only valid with fixed read/write, or buffer select */ |
|
if (req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT)) |
|
return -EINVAL; |
|
|
|
if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) { |
|
if (req->flags & REQ_F_BUFFER_SELECT) { |
|
buf = io_rw_buffer_select(req, &sqe_len, needs_lock); |
|
if (IS_ERR(buf)) |
|
return PTR_ERR(buf); |
|
req->rw.len = sqe_len; |
|
} |
|
|
|
ret = import_single_range(rw, buf, sqe_len, *iovec, iter); |
|
*iovec = NULL; |
|
return ret; |
|
} |
|
|
|
if (req->flags & REQ_F_BUFFER_SELECT) { |
|
ret = io_iov_buffer_select(req, *iovec, needs_lock); |
|
if (!ret) |
|
iov_iter_init(iter, rw, *iovec, 1, (*iovec)->iov_len); |
|
*iovec = NULL; |
|
return ret; |
|
} |
|
|
|
return __import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter, |
|
req->ctx->compat); |
|
} |
|
|
|
static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb) |
|
{ |
|
return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos; |
|
} |
|
|
|
/* |
|
* For files that don't have ->read_iter() and ->write_iter(), handle them |
|
* by looping over ->read() or ->write() manually. |
|
*/ |
|
static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter) |
|
{ |
|
struct kiocb *kiocb = &req->rw.kiocb; |
|
struct file *file = req->file; |
|
ssize_t ret = 0; |
|
|
|
/* |
|
* Don't support polled IO through this interface, and we can't |
|
* support non-blocking either. For the latter, this just causes |
|
* the kiocb to be handled from an async context. |
|
*/ |
|
if (kiocb->ki_flags & IOCB_HIPRI) |
|
return -EOPNOTSUPP; |
|
if (kiocb->ki_flags & IOCB_NOWAIT) |
|
return -EAGAIN; |
|
|
|
while (iov_iter_count(iter)) { |
|
struct iovec iovec; |
|
ssize_t nr; |
|
|
|
if (!iov_iter_is_bvec(iter)) { |
|
iovec = iov_iter_iovec(iter); |
|
} else { |
|
iovec.iov_base = u64_to_user_ptr(req->rw.addr); |
|
iovec.iov_len = req->rw.len; |
|
} |
|
|
|
if (rw == READ) { |
|
nr = file->f_op->read(file, iovec.iov_base, |
|
iovec.iov_len, io_kiocb_ppos(kiocb)); |
|
} else { |
|
nr = file->f_op->write(file, iovec.iov_base, |
|
iovec.iov_len, io_kiocb_ppos(kiocb)); |
|
} |
|
|
|
if (nr < 0) { |
|
if (!ret) |
|
ret = nr; |
|
break; |
|
} |
|
ret += nr; |
|
if (nr != iovec.iov_len) |
|
break; |
|
req->rw.len -= nr; |
|
req->rw.addr += nr; |
|
iov_iter_advance(iter, nr); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec, |
|
const struct iovec *fast_iov, struct iov_iter *iter) |
|
{ |
|
struct io_async_rw *rw = req->async_data; |
|
|
|
memcpy(&rw->iter, iter, sizeof(*iter)); |
|
rw->free_iovec = iovec; |
|
rw->bytes_done = 0; |
|
/* can only be fixed buffers, no need to do anything */ |
|
if (iov_iter_is_bvec(iter)) |
|
return; |
|
if (!iovec) { |
|
unsigned iov_off = 0; |
|
|
|
rw->iter.iov = rw->fast_iov; |
|
if (iter->iov != fast_iov) { |
|
iov_off = iter->iov - fast_iov; |
|
rw->iter.iov += iov_off; |
|
} |
|
if (rw->fast_iov != fast_iov) |
|
memcpy(rw->fast_iov + iov_off, fast_iov + iov_off, |
|
sizeof(struct iovec) * iter->nr_segs); |
|
} else { |
|
req->flags |= REQ_F_NEED_CLEANUP; |
|
} |
|
} |
|
|
|
static inline int __io_alloc_async_data(struct io_kiocb *req) |
|
{ |
|
WARN_ON_ONCE(!io_op_defs[req->opcode].async_size); |
|
req->async_data = kmalloc(io_op_defs[req->opcode].async_size, GFP_KERNEL); |
|
return req->async_data == NULL; |
|
} |
|
|
|
static int io_alloc_async_data(struct io_kiocb *req) |
|
{ |
|
if (!io_op_defs[req->opcode].needs_async_data) |
|
return 0; |
|
|
|
return __io_alloc_async_data(req); |
|
} |
|
|
|
static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec, |
|
const struct iovec *fast_iov, |
|
struct iov_iter *iter, bool force) |
|
{ |
|
if (!force && !io_op_defs[req->opcode].needs_async_data) |
|
return 0; |
|
if (!req->async_data) { |
|
if (__io_alloc_async_data(req)) { |
|
kfree(iovec); |
|
return -ENOMEM; |
|
} |
|
|
|
io_req_map_rw(req, iovec, fast_iov, iter); |
|
} |
|
return 0; |
|
} |
|
|
|
static inline int io_rw_prep_async(struct io_kiocb *req, int rw) |
|
{ |
|
struct io_async_rw *iorw = req->async_data; |
|
struct iovec *iov = iorw->fast_iov; |
|
int ret; |
|
|
|
ret = io_import_iovec(rw, req, &iov, &iorw->iter, false); |
|
if (unlikely(ret < 0)) |
|
return ret; |
|
|
|
iorw->bytes_done = 0; |
|
iorw->free_iovec = iov; |
|
if (iov) |
|
req->flags |= REQ_F_NEED_CLEANUP; |
|
return 0; |
|
} |
|
|
|
static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
if (unlikely(!(req->file->f_mode & FMODE_READ))) |
|
return -EBADF; |
|
return io_prep_rw(req, sqe); |
|
} |
|
|
|
/* |
|
* This is our waitqueue callback handler, registered through lock_page_async() |
|
* when we initially tried to do the IO with the iocb armed our waitqueue. |
|
* This gets called when the page is unlocked, and we generally expect that to |
|
* happen when the page IO is completed and the page is now uptodate. This will |
|
* queue a task_work based retry of the operation, attempting to copy the data |
|
* again. If the latter fails because the page was NOT uptodate, then we will |
|
* do a thread based blocking retry of the operation. That's the unexpected |
|
* slow path. |
|
*/ |
|
static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode, |
|
int sync, void *arg) |
|
{ |
|
struct wait_page_queue *wpq; |
|
struct io_kiocb *req = wait->private; |
|
struct wait_page_key *key = arg; |
|
|
|
wpq = container_of(wait, struct wait_page_queue, wait); |
|
|
|
if (!wake_page_match(wpq, key)) |
|
return 0; |
|
|
|
req->rw.kiocb.ki_flags &= ~IOCB_WAITQ; |
|
list_del_init(&wait->entry); |
|
|
|
/* submit ref gets dropped, acquire a new one */ |
|
refcount_inc(&req->refs); |
|
io_req_task_queue(req); |
|
return 1; |
|
} |
|
|
|
/* |
|
* This controls whether a given IO request should be armed for async page |
|
* based retry. If we return false here, the request is handed to the async |
|
* worker threads for retry. If we're doing buffered reads on a regular file, |
|
* we prepare a private wait_page_queue entry and retry the operation. This |
|
* will either succeed because the page is now uptodate and unlocked, or it |
|
* will register a callback when the page is unlocked at IO completion. Through |
|
* that callback, io_uring uses task_work to setup a retry of the operation. |
|
* That retry will attempt the buffered read again. The retry will generally |
|
* succeed, or in rare cases where it fails, we then fall back to using the |
|
* async worker threads for a blocking retry. |
|
*/ |
|
static bool io_rw_should_retry(struct io_kiocb *req) |
|
{ |
|
struct io_async_rw *rw = req->async_data; |
|
struct wait_page_queue *wait = &rw->wpq; |
|
struct kiocb *kiocb = &req->rw.kiocb; |
|
|
|
/* never retry for NOWAIT, we just complete with -EAGAIN */ |
|
if (req->flags & REQ_F_NOWAIT) |
|
return false; |
|
|
|
/* Only for buffered IO */ |
|
if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI)) |
|
return false; |
|
|
|
/* |
|
* just use poll if we can, and don't attempt if the fs doesn't |
|
* support callback based unlocks |
|
*/ |
|
if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC)) |
|
return false; |
|
|
|
wait->wait.func = io_async_buf_func; |
|
wait->wait.private = req; |
|
wait->wait.flags = 0; |
|
INIT_LIST_HEAD(&wait->wait.entry); |
|
kiocb->ki_flags |= IOCB_WAITQ; |
|
kiocb->ki_flags &= ~IOCB_NOWAIT; |
|
kiocb->ki_waitq = wait; |
|
return true; |
|
} |
|
|
|
static int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter) |
|
{ |
|
if (req->file->f_op->read_iter) |
|
return call_read_iter(req->file, &req->rw.kiocb, iter); |
|
else if (req->file->f_op->read) |
|
return loop_rw_iter(READ, req, iter); |
|
else |
|
return -EINVAL; |
|
} |
|
|
|
static int io_read(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; |
|
struct kiocb *kiocb = &req->rw.kiocb; |
|
struct iov_iter __iter, *iter = &__iter; |
|
struct io_async_rw *rw = req->async_data; |
|
ssize_t io_size, ret, ret2; |
|
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; |
|
|
|
if (rw) { |
|
iter = &rw->iter; |
|
iovec = NULL; |
|
} else { |
|
ret = io_import_iovec(READ, req, &iovec, iter, !force_nonblock); |
|
if (ret < 0) |
|
return ret; |
|
} |
|
io_size = iov_iter_count(iter); |
|
req->result = io_size; |
|
|
|
/* Ensure we clear previously set non-block flag */ |
|
if (!force_nonblock) |
|
kiocb->ki_flags &= ~IOCB_NOWAIT; |
|
else |
|
kiocb->ki_flags |= IOCB_NOWAIT; |
|
|
|
/* If the file doesn't support async, just async punt */ |
|
if (force_nonblock && !io_file_supports_async(req->file, READ)) { |
|
ret = io_setup_async_rw(req, iovec, inline_vecs, iter, true); |
|
return ret ?: -EAGAIN; |
|
} |
|
|
|
ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), io_size); |
|
if (unlikely(ret)) { |
|
kfree(iovec); |
|
return ret; |
|
} |
|
|
|
ret = io_iter_do_read(req, iter); |
|
|
|
if (ret == -EAGAIN || (req->flags & REQ_F_REISSUE)) { |
|
req->flags &= ~REQ_F_REISSUE; |
|
/* IOPOLL retry should happen for io-wq threads */ |
|
if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
goto done; |
|
/* no retry on NONBLOCK nor RWF_NOWAIT */ |
|
if (req->flags & REQ_F_NOWAIT) |
|
goto done; |
|
/* some cases will consume bytes even on error returns */ |
|
iov_iter_revert(iter, io_size - iov_iter_count(iter)); |
|
ret = 0; |
|
} else if (ret == -EIOCBQUEUED) { |
|
goto out_free; |
|
} else if (ret <= 0 || ret == io_size || !force_nonblock || |
|
(req->flags & REQ_F_NOWAIT) || !(req->flags & REQ_F_ISREG)) { |
|
/* read all, failed, already did sync or don't want to retry */ |
|
goto done; |
|
} |
|
|
|
ret2 = io_setup_async_rw(req, iovec, inline_vecs, iter, true); |
|
if (ret2) |
|
return ret2; |
|
|
|
iovec = NULL; |
|
rw = req->async_data; |
|
/* now use our persistent iterator, if we aren't already */ |
|
iter = &rw->iter; |
|
|
|
do { |
|
io_size -= ret; |
|
rw->bytes_done += ret; |
|
/* if we can retry, do so with the callbacks armed */ |
|
if (!io_rw_should_retry(req)) { |
|
kiocb->ki_flags &= ~IOCB_WAITQ; |
|
return -EAGAIN; |
|
} |
|
|
|
/* |
|
* Now retry read with the IOCB_WAITQ parts set in the iocb. If |
|
* we get -EIOCBQUEUED, then we'll get a notification when the |
|
* desired page gets unlocked. We can also get a partial read |
|
* here, and if we do, then just retry at the new offset. |
|
*/ |
|
ret = io_iter_do_read(req, iter); |
|
if (ret == -EIOCBQUEUED) |
|
return 0; |
|
/* we got some bytes, but not all. retry. */ |
|
kiocb->ki_flags &= ~IOCB_WAITQ; |
|
} while (ret > 0 && ret < io_size); |
|
done: |
|
kiocb_done(kiocb, ret, issue_flags); |
|
out_free: |
|
/* it's faster to check here then delegate to kfree */ |
|
if (iovec) |
|
kfree(iovec); |
|
return 0; |
|
} |
|
|
|
static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
if (unlikely(!(req->file->f_mode & FMODE_WRITE))) |
|
return -EBADF; |
|
return io_prep_rw(req, sqe); |
|
} |
|
|
|
static int io_write(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; |
|
struct kiocb *kiocb = &req->rw.kiocb; |
|
struct iov_iter __iter, *iter = &__iter; |
|
struct io_async_rw *rw = req->async_data; |
|
ssize_t ret, ret2, io_size; |
|
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; |
|
|
|
if (rw) { |
|
iter = &rw->iter; |
|
iovec = NULL; |
|
} else { |
|
ret = io_import_iovec(WRITE, req, &iovec, iter, !force_nonblock); |
|
if (ret < 0) |
|
return ret; |
|
} |
|
io_size = iov_iter_count(iter); |
|
req->result = io_size; |
|
|
|
/* Ensure we clear previously set non-block flag */ |
|
if (!force_nonblock) |
|
kiocb->ki_flags &= ~IOCB_NOWAIT; |
|
else |
|
kiocb->ki_flags |= IOCB_NOWAIT; |
|
|
|
/* If the file doesn't support async, just async punt */ |
|
if (force_nonblock && !io_file_supports_async(req->file, WRITE)) |
|
goto copy_iov; |
|
|
|
/* file path doesn't support NOWAIT for non-direct_IO */ |
|
if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) && |
|
(req->flags & REQ_F_ISREG)) |
|
goto copy_iov; |
|
|
|
ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), io_size); |
|
if (unlikely(ret)) |
|
goto out_free; |
|
|
|
/* |
|
* Open-code file_start_write here to grab freeze protection, |
|
* which will be released by another thread in |
|
* io_complete_rw(). Fool lockdep by telling it the lock got |
|
* released so that it doesn't complain about the held lock when |
|
* we return to userspace. |
|
*/ |
|
if (req->flags & REQ_F_ISREG) { |
|
sb_start_write(file_inode(req->file)->i_sb); |
|
__sb_writers_release(file_inode(req->file)->i_sb, |
|
SB_FREEZE_WRITE); |
|
} |
|
kiocb->ki_flags |= IOCB_WRITE; |
|
|
|
if (req->file->f_op->write_iter) |
|
ret2 = call_write_iter(req->file, kiocb, iter); |
|
else if (req->file->f_op->write) |
|
ret2 = loop_rw_iter(WRITE, req, iter); |
|
else |
|
ret2 = -EINVAL; |
|
|
|
if (req->flags & REQ_F_REISSUE) { |
|
req->flags &= ~REQ_F_REISSUE; |
|
ret2 = -EAGAIN; |
|
} |
|
|
|
/* |
|
* Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just |
|
* retry them without IOCB_NOWAIT. |
|
*/ |
|
if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT)) |
|
ret2 = -EAGAIN; |
|
/* no retry on NONBLOCK nor RWF_NOWAIT */ |
|
if (ret2 == -EAGAIN && (req->flags & REQ_F_NOWAIT)) |
|
goto done; |
|
if (!force_nonblock || ret2 != -EAGAIN) { |
|
/* IOPOLL retry should happen for io-wq threads */ |
|
if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN) |
|
goto copy_iov; |
|
done: |
|
kiocb_done(kiocb, ret2, issue_flags); |
|
} else { |
|
copy_iov: |
|
/* some cases will consume bytes even on error returns */ |
|
iov_iter_revert(iter, io_size - iov_iter_count(iter)); |
|
ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false); |
|
return ret ?: -EAGAIN; |
|
} |
|
out_free: |
|
/* it's reportedly faster than delegating the null check to kfree() */ |
|
if (iovec) |
|
kfree(iovec); |
|
return ret; |
|
} |
|
|
|
static int io_renameat_prep(struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_rename *ren = &req->rename; |
|
const char __user *oldf, *newf; |
|
|
|
if (unlikely(req->flags & REQ_F_FIXED_FILE)) |
|
return -EBADF; |
|
|
|
ren->old_dfd = READ_ONCE(sqe->fd); |
|
oldf = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
|
newf = u64_to_user_ptr(READ_ONCE(sqe->addr2)); |
|
ren->new_dfd = READ_ONCE(sqe->len); |
|
ren->flags = READ_ONCE(sqe->rename_flags); |
|
|
|
ren->oldpath = getname(oldf); |
|
if (IS_ERR(ren->oldpath)) |
|
return PTR_ERR(ren->oldpath); |
|
|
|
ren->newpath = getname(newf); |
|
if (IS_ERR(ren->newpath)) { |
|
putname(ren->oldpath); |
|
return PTR_ERR(ren->newpath); |
|
} |
|
|
|
req->flags |= REQ_F_NEED_CLEANUP; |
|
return 0; |
|
} |
|
|
|
static int io_renameat(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_rename *ren = &req->rename; |
|
int ret; |
|
|
|
if (issue_flags & IO_URING_F_NONBLOCK) |
|
return -EAGAIN; |
|
|
|
ret = do_renameat2(ren->old_dfd, ren->oldpath, ren->new_dfd, |
|
ren->newpath, ren->flags); |
|
|
|
req->flags &= ~REQ_F_NEED_CLEANUP; |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_req_complete(req, ret); |
|
return 0; |
|
} |
|
|
|
static int io_unlinkat_prep(struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_unlink *un = &req->unlink; |
|
const char __user *fname; |
|
|
|
if (unlikely(req->flags & REQ_F_FIXED_FILE)) |
|
return -EBADF; |
|
|
|
un->dfd = READ_ONCE(sqe->fd); |
|
|
|
un->flags = READ_ONCE(sqe->unlink_flags); |
|
if (un->flags & ~AT_REMOVEDIR) |
|
return -EINVAL; |
|
|
|
fname = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
|
un->filename = getname(fname); |
|
if (IS_ERR(un->filename)) |
|
return PTR_ERR(un->filename); |
|
|
|
req->flags |= REQ_F_NEED_CLEANUP; |
|
return 0; |
|
} |
|
|
|
static int io_unlinkat(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_unlink *un = &req->unlink; |
|
int ret; |
|
|
|
if (issue_flags & IO_URING_F_NONBLOCK) |
|
return -EAGAIN; |
|
|
|
if (un->flags & AT_REMOVEDIR) |
|
ret = do_rmdir(un->dfd, un->filename); |
|
else |
|
ret = do_unlinkat(un->dfd, un->filename); |
|
|
|
req->flags &= ~REQ_F_NEED_CLEANUP; |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_req_complete(req, ret); |
|
return 0; |
|
} |
|
|
|
static int io_shutdown_prep(struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
#if defined(CONFIG_NET) |
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
if (sqe->ioprio || sqe->off || sqe->addr || sqe->rw_flags || |
|
sqe->buf_index) |
|
return -EINVAL; |
|
|
|
req->shutdown.how = READ_ONCE(sqe->len); |
|
return 0; |
|
#else |
|
return -EOPNOTSUPP; |
|
#endif |
|
} |
|
|
|
static int io_shutdown(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
#if defined(CONFIG_NET) |
|
struct socket *sock; |
|
int ret; |
|
|
|
if (issue_flags & IO_URING_F_NONBLOCK) |
|
return -EAGAIN; |
|
|
|
sock = sock_from_file(req->file); |
|
if (unlikely(!sock)) |
|
return -ENOTSOCK; |
|
|
|
ret = __sys_shutdown_sock(sock, req->shutdown.how); |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_req_complete(req, ret); |
|
return 0; |
|
#else |
|
return -EOPNOTSUPP; |
|
#endif |
|
} |
|
|
|
static int __io_splice_prep(struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_splice* sp = &req->splice; |
|
unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL; |
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
|
|
sp->file_in = NULL; |
|
sp->len = READ_ONCE(sqe->len); |
|
sp->flags = READ_ONCE(sqe->splice_flags); |
|
|
|
if (unlikely(sp->flags & ~valid_flags)) |
|
return -EINVAL; |
|
|
|
sp->file_in = io_file_get(NULL, req, READ_ONCE(sqe->splice_fd_in), |
|
(sp->flags & SPLICE_F_FD_IN_FIXED)); |
|
if (!sp->file_in) |
|
return -EBADF; |
|
req->flags |= REQ_F_NEED_CLEANUP; |
|
|
|
if (!S_ISREG(file_inode(sp->file_in)->i_mode)) { |
|
/* |
|
* Splice operation will be punted aync, and here need to |
|
* modify io_wq_work.flags, so initialize io_wq_work firstly. |
|
*/ |
|
req->work.flags |= IO_WQ_WORK_UNBOUND; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int io_tee_prep(struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off)) |
|
return -EINVAL; |
|
return __io_splice_prep(req, sqe); |
|
} |
|
|
|
static int io_tee(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_splice *sp = &req->splice; |
|
struct file *in = sp->file_in; |
|
struct file *out = sp->file_out; |
|
unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED; |
|
long ret = 0; |
|
|
|
if (issue_flags & IO_URING_F_NONBLOCK) |
|
return -EAGAIN; |
|
if (sp->len) |
|
ret = do_tee(in, out, sp->len, flags); |
|
|
|
io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED)); |
|
req->flags &= ~REQ_F_NEED_CLEANUP; |
|
|
|
if (ret != sp->len) |
|
req_set_fail_links(req); |
|
io_req_complete(req, ret); |
|
return 0; |
|
} |
|
|
|
static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_splice* sp = &req->splice; |
|
|
|
sp->off_in = READ_ONCE(sqe->splice_off_in); |
|
sp->off_out = READ_ONCE(sqe->off); |
|
return __io_splice_prep(req, sqe); |
|
} |
|
|
|
static int io_splice(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_splice *sp = &req->splice; |
|
struct file *in = sp->file_in; |
|
struct file *out = sp->file_out; |
|
unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED; |
|
loff_t *poff_in, *poff_out; |
|
long ret = 0; |
|
|
|
if (issue_flags & IO_URING_F_NONBLOCK) |
|
return -EAGAIN; |
|
|
|
poff_in = (sp->off_in == -1) ? NULL : &sp->off_in; |
|
poff_out = (sp->off_out == -1) ? NULL : &sp->off_out; |
|
|
|
if (sp->len) |
|
ret = do_splice(in, poff_in, out, poff_out, sp->len, flags); |
|
|
|
io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED)); |
|
req->flags &= ~REQ_F_NEED_CLEANUP; |
|
|
|
if (ret != sp->len) |
|
req_set_fail_links(req); |
|
io_req_complete(req, ret); |
|
return 0; |
|
} |
|
|
|
/* |
|
* IORING_OP_NOP just posts a completion event, nothing else. |
|
*/ |
|
static int io_nop(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
|
|
__io_req_complete(req, issue_flags, 0, 0); |
|
return 0; |
|
} |
|
|
|
static int io_fsync_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
if (!req->file) |
|
return -EBADF; |
|
|
|
if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index)) |
|
return -EINVAL; |
|
|
|
req->sync.flags = READ_ONCE(sqe->fsync_flags); |
|
if (unlikely(req->sync.flags & ~IORING_FSYNC_DATASYNC)) |
|
return -EINVAL; |
|
|
|
req->sync.off = READ_ONCE(sqe->off); |
|
req->sync.len = READ_ONCE(sqe->len); |
|
return 0; |
|
} |
|
|
|
static int io_fsync(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
loff_t end = req->sync.off + req->sync.len; |
|
int ret; |
|
|
|
/* fsync always requires a blocking context */ |
|
if (issue_flags & IO_URING_F_NONBLOCK) |
|
return -EAGAIN; |
|
|
|
ret = vfs_fsync_range(req->file, req->sync.off, |
|
end > 0 ? end : LLONG_MAX, |
|
req->sync.flags & IORING_FSYNC_DATASYNC); |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_req_complete(req, ret); |
|
return 0; |
|
} |
|
|
|
static int io_fallocate_prep(struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
if (sqe->ioprio || sqe->buf_index || sqe->rw_flags) |
|
return -EINVAL; |
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
|
|
req->sync.off = READ_ONCE(sqe->off); |
|
req->sync.len = READ_ONCE(sqe->addr); |
|
req->sync.mode = READ_ONCE(sqe->len); |
|
return 0; |
|
} |
|
|
|
static int io_fallocate(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
int ret; |
|
|
|
/* fallocate always requiring blocking context */ |
|
if (issue_flags & IO_URING_F_NONBLOCK) |
|
return -EAGAIN; |
|
ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off, |
|
req->sync.len); |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_req_complete(req, ret); |
|
return 0; |
|
} |
|
|
|
static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
const char __user *fname; |
|
int ret; |
|
|
|
if (unlikely(sqe->ioprio || sqe->buf_index)) |
|
return -EINVAL; |
|
if (unlikely(req->flags & REQ_F_FIXED_FILE)) |
|
return -EBADF; |
|
|
|
/* open.how should be already initialised */ |
|
if (!(req->open.how.flags & O_PATH) && force_o_largefile()) |
|
req->open.how.flags |= O_LARGEFILE; |
|
|
|
req->open.dfd = READ_ONCE(sqe->fd); |
|
fname = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
|
req->open.filename = getname(fname); |
|
if (IS_ERR(req->open.filename)) { |
|
ret = PTR_ERR(req->open.filename); |
|
req->open.filename = NULL; |
|
return ret; |
|
} |
|
req->open.nofile = rlimit(RLIMIT_NOFILE); |
|
req->flags |= REQ_F_NEED_CLEANUP; |
|
return 0; |
|
} |
|
|
|
static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
u64 flags, mode; |
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
mode = READ_ONCE(sqe->len); |
|
flags = READ_ONCE(sqe->open_flags); |
|
req->open.how = build_open_how(flags, mode); |
|
return __io_openat_prep(req, sqe); |
|
} |
|
|
|
static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
struct open_how __user *how; |
|
size_t len; |
|
int ret; |
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
how = u64_to_user_ptr(READ_ONCE(sqe->addr2)); |
|
len = READ_ONCE(sqe->len); |
|
if (len < OPEN_HOW_SIZE_VER0) |
|
return -EINVAL; |
|
|
|
ret = copy_struct_from_user(&req->open.how, sizeof(req->open.how), how, |
|
len); |
|
if (ret) |
|
return ret; |
|
|
|
return __io_openat_prep(req, sqe); |
|
} |
|
|
|
static int io_openat2(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct open_flags op; |
|
struct file *file; |
|
bool nonblock_set; |
|
bool resolve_nonblock; |
|
int ret; |
|
|
|
ret = build_open_flags(&req->open.how, &op); |
|
if (ret) |
|
goto err; |
|
nonblock_set = op.open_flag & O_NONBLOCK; |
|
resolve_nonblock = req->open.how.resolve & RESOLVE_CACHED; |
|
if (issue_flags & IO_URING_F_NONBLOCK) { |
|
/* |
|
* Don't bother trying for O_TRUNC, O_CREAT, or O_TMPFILE open, |
|
* it'll always -EAGAIN |
|
*/ |
|
if (req->open.how.flags & (O_TRUNC | O_CREAT | O_TMPFILE)) |
|
return -EAGAIN; |
|
op.lookup_flags |= LOOKUP_CACHED; |
|
op.open_flag |= O_NONBLOCK; |
|
} |
|
|
|
ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile); |
|
if (ret < 0) |
|
goto err; |
|
|
|
file = do_filp_open(req->open.dfd, req->open.filename, &op); |
|
/* only retry if RESOLVE_CACHED wasn't already set by application */ |
|
if ((!resolve_nonblock && (issue_flags & IO_URING_F_NONBLOCK)) && |
|
file == ERR_PTR(-EAGAIN)) { |
|
/* |
|
* We could hang on to this 'fd', but seems like marginal |
|
* gain for something that is now known to be a slower path. |
|
* So just put it, and we'll get a new one when we retry. |
|
*/ |
|
put_unused_fd(ret); |
|
return -EAGAIN; |
|
} |
|
|
|
if (IS_ERR(file)) { |
|
put_unused_fd(ret); |
|
ret = PTR_ERR(file); |
|
} else { |
|
if ((issue_flags & IO_URING_F_NONBLOCK) && !nonblock_set) |
|
file->f_flags &= ~O_NONBLOCK; |
|
fsnotify_open(file); |
|
fd_install(ret, file); |
|
} |
|
err: |
|
putname(req->open.filename); |
|
req->flags &= ~REQ_F_NEED_CLEANUP; |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_req_complete(req, ret); |
|
return 0; |
|
} |
|
|
|
static int io_openat(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
return io_openat2(req, issue_flags); |
|
} |
|
|
|
static int io_remove_buffers_prep(struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_provide_buf *p = &req->pbuf; |
|
u64 tmp; |
|
|
|
if (sqe->ioprio || sqe->rw_flags || sqe->addr || sqe->len || sqe->off) |
|
return -EINVAL; |
|
|
|
tmp = READ_ONCE(sqe->fd); |
|
if (!tmp || tmp > USHRT_MAX) |
|
return -EINVAL; |
|
|
|
memset(p, 0, sizeof(*p)); |
|
p->nbufs = tmp; |
|
p->bgid = READ_ONCE(sqe->buf_group); |
|
return 0; |
|
} |
|
|
|
static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf, |
|
int bgid, unsigned nbufs) |
|
{ |
|
unsigned i = 0; |
|
|
|
/* shouldn't happen */ |
|
if (!nbufs) |
|
return 0; |
|
|
|
/* the head kbuf is the list itself */ |
|
while (!list_empty(&buf->list)) { |
|
struct io_buffer *nxt; |
|
|
|
nxt = list_first_entry(&buf->list, struct io_buffer, list); |
|
list_del(&nxt->list); |
|
kfree(nxt); |
|
if (++i == nbufs) |
|
return i; |
|
} |
|
i++; |
|
kfree(buf); |
|
xa_erase(&ctx->io_buffers, bgid); |
|
|
|
return i; |
|
} |
|
|
|
static int io_remove_buffers(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_provide_buf *p = &req->pbuf; |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct io_buffer *head; |
|
int ret = 0; |
|
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; |
|
|
|
io_ring_submit_lock(ctx, !force_nonblock); |
|
|
|
lockdep_assert_held(&ctx->uring_lock); |
|
|
|
ret = -ENOENT; |
|
head = xa_load(&ctx->io_buffers, p->bgid); |
|
if (head) |
|
ret = __io_remove_buffers(ctx, head, p->bgid, p->nbufs); |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
|
|
/* need to hold the lock to complete IOPOLL requests */ |
|
if (ctx->flags & IORING_SETUP_IOPOLL) { |
|
__io_req_complete(req, issue_flags, ret, 0); |
|
io_ring_submit_unlock(ctx, !force_nonblock); |
|
} else { |
|
io_ring_submit_unlock(ctx, !force_nonblock); |
|
__io_req_complete(req, issue_flags, ret, 0); |
|
} |
|
return 0; |
|
} |
|
|
|
static int io_provide_buffers_prep(struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
unsigned long size, tmp_check; |
|
struct io_provide_buf *p = &req->pbuf; |
|
u64 tmp; |
|
|
|
if (sqe->ioprio || sqe->rw_flags) |
|
return -EINVAL; |
|
|
|
tmp = READ_ONCE(sqe->fd); |
|
if (!tmp || tmp > USHRT_MAX) |
|
return -E2BIG; |
|
p->nbufs = tmp; |
|
p->addr = READ_ONCE(sqe->addr); |
|
p->len = READ_ONCE(sqe->len); |
|
|
|
if (check_mul_overflow((unsigned long)p->len, (unsigned long)p->nbufs, |
|
&size)) |
|
return -EOVERFLOW; |
|
if (check_add_overflow((unsigned long)p->addr, size, &tmp_check)) |
|
return -EOVERFLOW; |
|
|
|
size = (unsigned long)p->len * p->nbufs; |
|
if (!access_ok(u64_to_user_ptr(p->addr), size)) |
|
return -EFAULT; |
|
|
|
p->bgid = READ_ONCE(sqe->buf_group); |
|
tmp = READ_ONCE(sqe->off); |
|
if (tmp > USHRT_MAX) |
|
return -E2BIG; |
|
p->bid = tmp; |
|
return 0; |
|
} |
|
|
|
static int io_add_buffers(struct io_provide_buf *pbuf, struct io_buffer **head) |
|
{ |
|
struct io_buffer *buf; |
|
u64 addr = pbuf->addr; |
|
int i, bid = pbuf->bid; |
|
|
|
for (i = 0; i < pbuf->nbufs; i++) { |
|
buf = kmalloc(sizeof(*buf), GFP_KERNEL); |
|
if (!buf) |
|
break; |
|
|
|
buf->addr = addr; |
|
buf->len = min_t(__u32, pbuf->len, MAX_RW_COUNT); |
|
buf->bid = bid; |
|
addr += pbuf->len; |
|
bid++; |
|
if (!*head) { |
|
INIT_LIST_HEAD(&buf->list); |
|
*head = buf; |
|
} else { |
|
list_add_tail(&buf->list, &(*head)->list); |
|
} |
|
} |
|
|
|
return i ? i : -ENOMEM; |
|
} |
|
|
|
static int io_provide_buffers(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_provide_buf *p = &req->pbuf; |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct io_buffer *head, *list; |
|
int ret = 0; |
|
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; |
|
|
|
io_ring_submit_lock(ctx, !force_nonblock); |
|
|
|
lockdep_assert_held(&ctx->uring_lock); |
|
|
|
list = head = xa_load(&ctx->io_buffers, p->bgid); |
|
|
|
ret = io_add_buffers(p, &head); |
|
if (ret >= 0 && !list) { |
|
ret = xa_insert(&ctx->io_buffers, p->bgid, head, GFP_KERNEL); |
|
if (ret < 0) |
|
__io_remove_buffers(ctx, head, p->bgid, -1U); |
|
} |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
|
|
/* need to hold the lock to complete IOPOLL requests */ |
|
if (ctx->flags & IORING_SETUP_IOPOLL) { |
|
__io_req_complete(req, issue_flags, ret, 0); |
|
io_ring_submit_unlock(ctx, !force_nonblock); |
|
} else { |
|
io_ring_submit_unlock(ctx, !force_nonblock); |
|
__io_req_complete(req, issue_flags, ret, 0); |
|
} |
|
return 0; |
|
} |
|
|
|
static int io_epoll_ctl_prep(struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
#if defined(CONFIG_EPOLL) |
|
if (sqe->ioprio || sqe->buf_index) |
|
return -EINVAL; |
|
if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL))) |
|
return -EINVAL; |
|
|
|
req->epoll.epfd = READ_ONCE(sqe->fd); |
|
req->epoll.op = READ_ONCE(sqe->len); |
|
req->epoll.fd = READ_ONCE(sqe->off); |
|
|
|
if (ep_op_has_event(req->epoll.op)) { |
|
struct epoll_event __user *ev; |
|
|
|
ev = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
|
if (copy_from_user(&req->epoll.event, ev, sizeof(*ev))) |
|
return -EFAULT; |
|
} |
|
|
|
return 0; |
|
#else |
|
return -EOPNOTSUPP; |
|
#endif |
|
} |
|
|
|
static int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
#if defined(CONFIG_EPOLL) |
|
struct io_epoll *ie = &req->epoll; |
|
int ret; |
|
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; |
|
|
|
ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock); |
|
if (force_nonblock && ret == -EAGAIN) |
|
return -EAGAIN; |
|
|
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
__io_req_complete(req, issue_flags, ret, 0); |
|
return 0; |
|
#else |
|
return -EOPNOTSUPP; |
|
#endif |
|
} |
|
|
|
static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU) |
|
if (sqe->ioprio || sqe->buf_index || sqe->off) |
|
return -EINVAL; |
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
|
|
req->madvise.addr = READ_ONCE(sqe->addr); |
|
req->madvise.len = READ_ONCE(sqe->len); |
|
req->madvise.advice = READ_ONCE(sqe->fadvise_advice); |
|
return 0; |
|
#else |
|
return -EOPNOTSUPP; |
|
#endif |
|
} |
|
|
|
static int io_madvise(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU) |
|
struct io_madvise *ma = &req->madvise; |
|
int ret; |
|
|
|
if (issue_flags & IO_URING_F_NONBLOCK) |
|
return -EAGAIN; |
|
|
|
ret = do_madvise(current->mm, ma->addr, ma->len, ma->advice); |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_req_complete(req, ret); |
|
return 0; |
|
#else |
|
return -EOPNOTSUPP; |
|
#endif |
|
} |
|
|
|
static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
if (sqe->ioprio || sqe->buf_index || sqe->addr) |
|
return -EINVAL; |
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
|
|
req->fadvise.offset = READ_ONCE(sqe->off); |
|
req->fadvise.len = READ_ONCE(sqe->len); |
|
req->fadvise.advice = READ_ONCE(sqe->fadvise_advice); |
|
return 0; |
|
} |
|
|
|
static int io_fadvise(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_fadvise *fa = &req->fadvise; |
|
int ret; |
|
|
|
if (issue_flags & IO_URING_F_NONBLOCK) { |
|
switch (fa->advice) { |
|
case POSIX_FADV_NORMAL: |
|
case POSIX_FADV_RANDOM: |
|
case POSIX_FADV_SEQUENTIAL: |
|
break; |
|
default: |
|
return -EAGAIN; |
|
} |
|
} |
|
|
|
ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice); |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_req_complete(req, ret); |
|
return 0; |
|
} |
|
|
|
static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL))) |
|
return -EINVAL; |
|
if (sqe->ioprio || sqe->buf_index) |
|
return -EINVAL; |
|
if (req->flags & REQ_F_FIXED_FILE) |
|
return -EBADF; |
|
|
|
req->statx.dfd = READ_ONCE(sqe->fd); |
|
req->statx.mask = READ_ONCE(sqe->len); |
|
req->statx.filename = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
|
req->statx.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2)); |
|
req->statx.flags = READ_ONCE(sqe->statx_flags); |
|
|
|
return 0; |
|
} |
|
|
|
static int io_statx(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_statx *ctx = &req->statx; |
|
int ret; |
|
|
|
if (issue_flags & IO_URING_F_NONBLOCK) { |
|
/* only need file table for an actual valid fd */ |
|
if (ctx->dfd == -1 || ctx->dfd == AT_FDCWD) |
|
req->flags |= REQ_F_NO_FILE_TABLE; |
|
return -EAGAIN; |
|
} |
|
|
|
ret = do_statx(ctx->dfd, ctx->filename, ctx->flags, ctx->mask, |
|
ctx->buffer); |
|
|
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_req_complete(req, ret); |
|
return 0; |
|
} |
|
|
|
static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
if (sqe->ioprio || sqe->off || sqe->addr || sqe->len || |
|
sqe->rw_flags || sqe->buf_index) |
|
return -EINVAL; |
|
if (req->flags & REQ_F_FIXED_FILE) |
|
return -EBADF; |
|
|
|
req->close.fd = READ_ONCE(sqe->fd); |
|
return 0; |
|
} |
|
|
|
static int io_close(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct files_struct *files = current->files; |
|
struct io_close *close = &req->close; |
|
struct fdtable *fdt; |
|
struct file *file; |
|
int ret; |
|
|
|
file = NULL; |
|
ret = -EBADF; |
|
spin_lock(&files->file_lock); |
|
fdt = files_fdtable(files); |
|
if (close->fd >= fdt->max_fds) { |
|
spin_unlock(&files->file_lock); |
|
goto err; |
|
} |
|
file = fdt->fd[close->fd]; |
|
if (!file) { |
|
spin_unlock(&files->file_lock); |
|
goto err; |
|
} |
|
|
|
if (file->f_op == &io_uring_fops) { |
|
spin_unlock(&files->file_lock); |
|
file = NULL; |
|
goto err; |
|
} |
|
|
|
/* if the file has a flush method, be safe and punt to async */ |
|
if (file->f_op->flush && (issue_flags & IO_URING_F_NONBLOCK)) { |
|
spin_unlock(&files->file_lock); |
|
return -EAGAIN; |
|
} |
|
|
|
ret = __close_fd_get_file(close->fd, &file); |
|
spin_unlock(&files->file_lock); |
|
if (ret < 0) { |
|
if (ret == -ENOENT) |
|
ret = -EBADF; |
|
goto err; |
|
} |
|
|
|
/* No ->flush() or already async, safely close from here */ |
|
ret = filp_close(file, current->files); |
|
err: |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
if (file) |
|
fput(file); |
|
__io_req_complete(req, issue_flags, ret, 0); |
|
return 0; |
|
} |
|
|
|
static int io_sfr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index)) |
|
return -EINVAL; |
|
|
|
req->sync.off = READ_ONCE(sqe->off); |
|
req->sync.len = READ_ONCE(sqe->len); |
|
req->sync.flags = READ_ONCE(sqe->sync_range_flags); |
|
return 0; |
|
} |
|
|
|
static int io_sync_file_range(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
int ret; |
|
|
|
/* sync_file_range always requires a blocking context */ |
|
if (issue_flags & IO_URING_F_NONBLOCK) |
|
return -EAGAIN; |
|
|
|
ret = sync_file_range(req->file, req->sync.off, req->sync.len, |
|
req->sync.flags); |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_req_complete(req, ret); |
|
return 0; |
|
} |
|
|
|
#if defined(CONFIG_NET) |
|
static int io_setup_async_msg(struct io_kiocb *req, |
|
struct io_async_msghdr *kmsg) |
|
{ |
|
struct io_async_msghdr *async_msg = req->async_data; |
|
|
|
if (async_msg) |
|
return -EAGAIN; |
|
if (io_alloc_async_data(req)) { |
|
kfree(kmsg->free_iov); |
|
return -ENOMEM; |
|
} |
|
async_msg = req->async_data; |
|
req->flags |= REQ_F_NEED_CLEANUP; |
|
memcpy(async_msg, kmsg, sizeof(*kmsg)); |
|
async_msg->msg.msg_name = &async_msg->addr; |
|
/* if were using fast_iov, set it to the new one */ |
|
if (!async_msg->free_iov) |
|
async_msg->msg.msg_iter.iov = async_msg->fast_iov; |
|
|
|
return -EAGAIN; |
|
} |
|
|
|
static int io_sendmsg_copy_hdr(struct io_kiocb *req, |
|
struct io_async_msghdr *iomsg) |
|
{ |
|
iomsg->msg.msg_name = &iomsg->addr; |
|
iomsg->free_iov = iomsg->fast_iov; |
|
return sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg, |
|
req->sr_msg.msg_flags, &iomsg->free_iov); |
|
} |
|
|
|
static int io_sendmsg_prep_async(struct io_kiocb *req) |
|
{ |
|
int ret; |
|
|
|
if (!io_op_defs[req->opcode].needs_async_data) |
|
return 0; |
|
ret = io_sendmsg_copy_hdr(req, req->async_data); |
|
if (!ret) |
|
req->flags |= REQ_F_NEED_CLEANUP; |
|
return ret; |
|
} |
|
|
|
static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_sr_msg *sr = &req->sr_msg; |
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
|
|
sr->msg_flags = READ_ONCE(sqe->msg_flags); |
|
sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
|
sr->len = READ_ONCE(sqe->len); |
|
|
|
#ifdef CONFIG_COMPAT |
|
if (req->ctx->compat) |
|
sr->msg_flags |= MSG_CMSG_COMPAT; |
|
#endif |
|
return 0; |
|
} |
|
|
|
static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_async_msghdr iomsg, *kmsg; |
|
struct socket *sock; |
|
unsigned flags; |
|
int min_ret = 0; |
|
int ret; |
|
|
|
sock = sock_from_file(req->file); |
|
if (unlikely(!sock)) |
|
return -ENOTSOCK; |
|
|
|
kmsg = req->async_data; |
|
if (!kmsg) { |
|
ret = io_sendmsg_copy_hdr(req, &iomsg); |
|
if (ret) |
|
return ret; |
|
kmsg = &iomsg; |
|
} |
|
|
|
flags = req->sr_msg.msg_flags | MSG_NOSIGNAL; |
|
if (flags & MSG_DONTWAIT) |
|
req->flags |= REQ_F_NOWAIT; |
|
else if (issue_flags & IO_URING_F_NONBLOCK) |
|
flags |= MSG_DONTWAIT; |
|
|
|
if (flags & MSG_WAITALL) |
|
min_ret = iov_iter_count(&kmsg->msg.msg_iter); |
|
|
|
ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags); |
|
if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN) |
|
return io_setup_async_msg(req, kmsg); |
|
if (ret == -ERESTARTSYS) |
|
ret = -EINTR; |
|
|
|
/* fast path, check for non-NULL to avoid function call */ |
|
if (kmsg->free_iov) |
|
kfree(kmsg->free_iov); |
|
req->flags &= ~REQ_F_NEED_CLEANUP; |
|
if (ret < min_ret) |
|
req_set_fail_links(req); |
|
__io_req_complete(req, issue_flags, ret, 0); |
|
return 0; |
|
} |
|
|
|
static int io_send(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_sr_msg *sr = &req->sr_msg; |
|
struct msghdr msg; |
|
struct iovec iov; |
|
struct socket *sock; |
|
unsigned flags; |
|
int min_ret = 0; |
|
int ret; |
|
|
|
sock = sock_from_file(req->file); |
|
if (unlikely(!sock)) |
|
return -ENOTSOCK; |
|
|
|
ret = import_single_range(WRITE, sr->buf, sr->len, &iov, &msg.msg_iter); |
|
if (unlikely(ret)) |
|
return ret; |
|
|
|
msg.msg_name = NULL; |
|
msg.msg_control = NULL; |
|
msg.msg_controllen = 0; |
|
msg.msg_namelen = 0; |
|
|
|
flags = req->sr_msg.msg_flags | MSG_NOSIGNAL; |
|
if (flags & MSG_DONTWAIT) |
|
req->flags |= REQ_F_NOWAIT; |
|
else if (issue_flags & IO_URING_F_NONBLOCK) |
|
flags |= MSG_DONTWAIT; |
|
|
|
if (flags & MSG_WAITALL) |
|
min_ret = iov_iter_count(&msg.msg_iter); |
|
|
|
msg.msg_flags = flags; |
|
ret = sock_sendmsg(sock, &msg); |
|
if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN) |
|
return -EAGAIN; |
|
if (ret == -ERESTARTSYS) |
|
ret = -EINTR; |
|
|
|
if (ret < min_ret) |
|
req_set_fail_links(req); |
|
__io_req_complete(req, issue_flags, ret, 0); |
|
return 0; |
|
} |
|
|
|
static int __io_recvmsg_copy_hdr(struct io_kiocb *req, |
|
struct io_async_msghdr *iomsg) |
|
{ |
|
struct io_sr_msg *sr = &req->sr_msg; |
|
struct iovec __user *uiov; |
|
size_t iov_len; |
|
int ret; |
|
|
|
ret = __copy_msghdr_from_user(&iomsg->msg, sr->umsg, |
|
&iomsg->uaddr, &uiov, &iov_len); |
|
if (ret) |
|
return ret; |
|
|
|
if (req->flags & REQ_F_BUFFER_SELECT) { |
|
if (iov_len > 1) |
|
return -EINVAL; |
|
if (copy_from_user(iomsg->fast_iov, uiov, sizeof(*uiov))) |
|
return -EFAULT; |
|
sr->len = iomsg->fast_iov[0].iov_len; |
|
iomsg->free_iov = NULL; |
|
} else { |
|
iomsg->free_iov = iomsg->fast_iov; |
|
ret = __import_iovec(READ, uiov, iov_len, UIO_FASTIOV, |
|
&iomsg->free_iov, &iomsg->msg.msg_iter, |
|
false); |
|
if (ret > 0) |
|
ret = 0; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
#ifdef CONFIG_COMPAT |
|
static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req, |
|
struct io_async_msghdr *iomsg) |
|
{ |
|
struct compat_msghdr __user *msg_compat; |
|
struct io_sr_msg *sr = &req->sr_msg; |
|
struct compat_iovec __user *uiov; |
|
compat_uptr_t ptr; |
|
compat_size_t len; |
|
int ret; |
|
|
|
msg_compat = (struct compat_msghdr __user *) sr->umsg; |
|
ret = __get_compat_msghdr(&iomsg->msg, msg_compat, &iomsg->uaddr, |
|
&ptr, &len); |
|
if (ret) |
|
return ret; |
|
|
|
uiov = compat_ptr(ptr); |
|
if (req->flags & REQ_F_BUFFER_SELECT) { |
|
compat_ssize_t clen; |
|
|
|
if (len > 1) |
|
return -EINVAL; |
|
if (!access_ok(uiov, sizeof(*uiov))) |
|
return -EFAULT; |
|
if (__get_user(clen, &uiov->iov_len)) |
|
return -EFAULT; |
|
if (clen < 0) |
|
return -EINVAL; |
|
sr->len = clen; |
|
iomsg->free_iov = NULL; |
|
} else { |
|
iomsg->free_iov = iomsg->fast_iov; |
|
ret = __import_iovec(READ, (struct iovec __user *)uiov, len, |
|
UIO_FASTIOV, &iomsg->free_iov, |
|
&iomsg->msg.msg_iter, true); |
|
if (ret < 0) |
|
return ret; |
|
} |
|
|
|
return 0; |
|
} |
|
#endif |
|
|
|
static int io_recvmsg_copy_hdr(struct io_kiocb *req, |
|
struct io_async_msghdr *iomsg) |
|
{ |
|
iomsg->msg.msg_name = &iomsg->addr; |
|
|
|
#ifdef CONFIG_COMPAT |
|
if (req->ctx->compat) |
|
return __io_compat_recvmsg_copy_hdr(req, iomsg); |
|
#endif |
|
|
|
return __io_recvmsg_copy_hdr(req, iomsg); |
|
} |
|
|
|
static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req, |
|
bool needs_lock) |
|
{ |
|
struct io_sr_msg *sr = &req->sr_msg; |
|
struct io_buffer *kbuf; |
|
|
|
kbuf = io_buffer_select(req, &sr->len, sr->bgid, sr->kbuf, needs_lock); |
|
if (IS_ERR(kbuf)) |
|
return kbuf; |
|
|
|
sr->kbuf = kbuf; |
|
req->flags |= REQ_F_BUFFER_SELECTED; |
|
return kbuf; |
|
} |
|
|
|
static inline unsigned int io_put_recv_kbuf(struct io_kiocb *req) |
|
{ |
|
return io_put_kbuf(req, req->sr_msg.kbuf); |
|
} |
|
|
|
static int io_recvmsg_prep_async(struct io_kiocb *req) |
|
{ |
|
int ret; |
|
|
|
if (!io_op_defs[req->opcode].needs_async_data) |
|
return 0; |
|
ret = io_recvmsg_copy_hdr(req, req->async_data); |
|
if (!ret) |
|
req->flags |= REQ_F_NEED_CLEANUP; |
|
return ret; |
|
} |
|
|
|
static int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_sr_msg *sr = &req->sr_msg; |
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
|
|
sr->msg_flags = READ_ONCE(sqe->msg_flags); |
|
sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
|
sr->len = READ_ONCE(sqe->len); |
|
sr->bgid = READ_ONCE(sqe->buf_group); |
|
|
|
#ifdef CONFIG_COMPAT |
|
if (req->ctx->compat) |
|
sr->msg_flags |= MSG_CMSG_COMPAT; |
|
#endif |
|
return 0; |
|
} |
|
|
|
static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_async_msghdr iomsg, *kmsg; |
|
struct socket *sock; |
|
struct io_buffer *kbuf; |
|
unsigned flags; |
|
int min_ret = 0; |
|
int ret, cflags = 0; |
|
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; |
|
|
|
sock = sock_from_file(req->file); |
|
if (unlikely(!sock)) |
|
return -ENOTSOCK; |
|
|
|
kmsg = req->async_data; |
|
if (!kmsg) { |
|
ret = io_recvmsg_copy_hdr(req, &iomsg); |
|
if (ret) |
|
return ret; |
|
kmsg = &iomsg; |
|
} |
|
|
|
if (req->flags & REQ_F_BUFFER_SELECT) { |
|
kbuf = io_recv_buffer_select(req, !force_nonblock); |
|
if (IS_ERR(kbuf)) |
|
return PTR_ERR(kbuf); |
|
kmsg->fast_iov[0].iov_base = u64_to_user_ptr(kbuf->addr); |
|
kmsg->fast_iov[0].iov_len = req->sr_msg.len; |
|
iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->fast_iov, |
|
1, req->sr_msg.len); |
|
} |
|
|
|
flags = req->sr_msg.msg_flags | MSG_NOSIGNAL; |
|
if (flags & MSG_DONTWAIT) |
|
req->flags |= REQ_F_NOWAIT; |
|
else if (force_nonblock) |
|
flags |= MSG_DONTWAIT; |
|
|
|
if (flags & MSG_WAITALL) |
|
min_ret = iov_iter_count(&kmsg->msg.msg_iter); |
|
|
|
ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg, |
|
kmsg->uaddr, flags); |
|
if (force_nonblock && ret == -EAGAIN) |
|
return io_setup_async_msg(req, kmsg); |
|
if (ret == -ERESTARTSYS) |
|
ret = -EINTR; |
|
|
|
if (req->flags & REQ_F_BUFFER_SELECTED) |
|
cflags = io_put_recv_kbuf(req); |
|
/* fast path, check for non-NULL to avoid function call */ |
|
if (kmsg->free_iov) |
|
kfree(kmsg->free_iov); |
|
req->flags &= ~REQ_F_NEED_CLEANUP; |
|
if (ret < min_ret || ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC)))) |
|
req_set_fail_links(req); |
|
__io_req_complete(req, issue_flags, ret, cflags); |
|
return 0; |
|
} |
|
|
|
static int io_recv(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_buffer *kbuf; |
|
struct io_sr_msg *sr = &req->sr_msg; |
|
struct msghdr msg; |
|
void __user *buf = sr->buf; |
|
struct socket *sock; |
|
struct iovec iov; |
|
unsigned flags; |
|
int min_ret = 0; |
|
int ret, cflags = 0; |
|
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; |
|
|
|
sock = sock_from_file(req->file); |
|
if (unlikely(!sock)) |
|
return -ENOTSOCK; |
|
|
|
if (req->flags & REQ_F_BUFFER_SELECT) { |
|
kbuf = io_recv_buffer_select(req, !force_nonblock); |
|
if (IS_ERR(kbuf)) |
|
return PTR_ERR(kbuf); |
|
buf = u64_to_user_ptr(kbuf->addr); |
|
} |
|
|
|
ret = import_single_range(READ, buf, sr->len, &iov, &msg.msg_iter); |
|
if (unlikely(ret)) |
|
goto out_free; |
|
|
|
msg.msg_name = NULL; |
|
msg.msg_control = NULL; |
|
msg.msg_controllen = 0; |
|
msg.msg_namelen = 0; |
|
msg.msg_iocb = NULL; |
|
msg.msg_flags = 0; |
|
|
|
flags = req->sr_msg.msg_flags | MSG_NOSIGNAL; |
|
if (flags & MSG_DONTWAIT) |
|
req->flags |= REQ_F_NOWAIT; |
|
else if (force_nonblock) |
|
flags |= MSG_DONTWAIT; |
|
|
|
if (flags & MSG_WAITALL) |
|
min_ret = iov_iter_count(&msg.msg_iter); |
|
|
|
ret = sock_recvmsg(sock, &msg, flags); |
|
if (force_nonblock && ret == -EAGAIN) |
|
return -EAGAIN; |
|
if (ret == -ERESTARTSYS) |
|
ret = -EINTR; |
|
out_free: |
|
if (req->flags & REQ_F_BUFFER_SELECTED) |
|
cflags = io_put_recv_kbuf(req); |
|
if (ret < min_ret || ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC)))) |
|
req_set_fail_links(req); |
|
__io_req_complete(req, issue_flags, ret, cflags); |
|
return 0; |
|
} |
|
|
|
static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_accept *accept = &req->accept; |
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
if (sqe->ioprio || sqe->len || sqe->buf_index) |
|
return -EINVAL; |
|
|
|
accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
|
accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2)); |
|
accept->flags = READ_ONCE(sqe->accept_flags); |
|
accept->nofile = rlimit(RLIMIT_NOFILE); |
|
return 0; |
|
} |
|
|
|
static int io_accept(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_accept *accept = &req->accept; |
|
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; |
|
unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0; |
|
int ret; |
|
|
|
if (req->file->f_flags & O_NONBLOCK) |
|
req->flags |= REQ_F_NOWAIT; |
|
|
|
ret = __sys_accept4_file(req->file, file_flags, accept->addr, |
|
accept->addr_len, accept->flags, |
|
accept->nofile); |
|
if (ret == -EAGAIN && force_nonblock) |
|
return -EAGAIN; |
|
if (ret < 0) { |
|
if (ret == -ERESTARTSYS) |
|
ret = -EINTR; |
|
req_set_fail_links(req); |
|
} |
|
__io_req_complete(req, issue_flags, ret, 0); |
|
return 0; |
|
} |
|
|
|
static int io_connect_prep_async(struct io_kiocb *req) |
|
{ |
|
struct io_async_connect *io = req->async_data; |
|
struct io_connect *conn = &req->connect; |
|
|
|
return move_addr_to_kernel(conn->addr, conn->addr_len, &io->address); |
|
} |
|
|
|
static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_connect *conn = &req->connect; |
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags) |
|
return -EINVAL; |
|
|
|
conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
|
conn->addr_len = READ_ONCE(sqe->addr2); |
|
return 0; |
|
} |
|
|
|
static int io_connect(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_async_connect __io, *io; |
|
unsigned file_flags; |
|
int ret; |
|
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; |
|
|
|
if (req->async_data) { |
|
io = req->async_data; |
|
} else { |
|
ret = move_addr_to_kernel(req->connect.addr, |
|
req->connect.addr_len, |
|
&__io.address); |
|
if (ret) |
|
goto out; |
|
io = &__io; |
|
} |
|
|
|
file_flags = force_nonblock ? O_NONBLOCK : 0; |
|
|
|
ret = __sys_connect_file(req->file, &io->address, |
|
req->connect.addr_len, file_flags); |
|
if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) { |
|
if (req->async_data) |
|
return -EAGAIN; |
|
if (io_alloc_async_data(req)) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
memcpy(req->async_data, &__io, sizeof(__io)); |
|
return -EAGAIN; |
|
} |
|
if (ret == -ERESTARTSYS) |
|
ret = -EINTR; |
|
out: |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
__io_req_complete(req, issue_flags, ret, 0); |
|
return 0; |
|
} |
|
#else /* !CONFIG_NET */ |
|
#define IO_NETOP_FN(op) \ |
|
static int io_##op(struct io_kiocb *req, unsigned int issue_flags) \ |
|
{ \ |
|
return -EOPNOTSUPP; \ |
|
} |
|
|
|
#define IO_NETOP_PREP(op) \ |
|
IO_NETOP_FN(op) \ |
|
static int io_##op##_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) \ |
|
{ \ |
|
return -EOPNOTSUPP; \ |
|
} \ |
|
|
|
#define IO_NETOP_PREP_ASYNC(op) \ |
|
IO_NETOP_PREP(op) \ |
|
static int io_##op##_prep_async(struct io_kiocb *req) \ |
|
{ \ |
|
return -EOPNOTSUPP; \ |
|
} |
|
|
|
IO_NETOP_PREP_ASYNC(sendmsg); |
|
IO_NETOP_PREP_ASYNC(recvmsg); |
|
IO_NETOP_PREP_ASYNC(connect); |
|
IO_NETOP_PREP(accept); |
|
IO_NETOP_FN(send); |
|
IO_NETOP_FN(recv); |
|
#endif /* CONFIG_NET */ |
|
|
|
struct io_poll_table { |
|
struct poll_table_struct pt; |
|
struct io_kiocb *req; |
|
int error; |
|
}; |
|
|
|
static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll, |
|
__poll_t mask, task_work_func_t func) |
|
{ |
|
int ret; |
|
|
|
/* for instances that support it check for an event match first: */ |
|
if (mask && !(mask & poll->events)) |
|
return 0; |
|
|
|
trace_io_uring_task_add(req->ctx, req->opcode, req->user_data, mask); |
|
|
|
list_del_init(&poll->wait.entry); |
|
|
|
req->result = mask; |
|
req->task_work.func = func; |
|
percpu_ref_get(&req->ctx->refs); |
|
|
|
/* |
|
* If this fails, then the task is exiting. When a task exits, the |
|
* work gets canceled, so just cancel this request as well instead |
|
* of executing it. We can't safely execute it anyway, as we may not |
|
* have the needed state needed for it anyway. |
|
*/ |
|
ret = io_req_task_work_add(req); |
|
if (unlikely(ret)) { |
|
WRITE_ONCE(poll->canceled, true); |
|
io_req_task_work_add_fallback(req, func); |
|
} |
|
return 1; |
|
} |
|
|
|
static bool io_poll_rewait(struct io_kiocb *req, struct io_poll_iocb *poll) |
|
__acquires(&req->ctx->completion_lock) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
if (!req->result && !READ_ONCE(poll->canceled)) { |
|
struct poll_table_struct pt = { ._key = poll->events }; |
|
|
|
req->result = vfs_poll(req->file, &pt) & poll->events; |
|
} |
|
|
|
spin_lock_irq(&ctx->completion_lock); |
|
if (!req->result && !READ_ONCE(poll->canceled)) { |
|
add_wait_queue(poll->head, &poll->wait); |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
static struct io_poll_iocb *io_poll_get_double(struct io_kiocb *req) |
|
{ |
|
/* pure poll stashes this in ->async_data, poll driven retry elsewhere */ |
|
if (req->opcode == IORING_OP_POLL_ADD) |
|
return req->async_data; |
|
return req->apoll->double_poll; |
|
} |
|
|
|
static struct io_poll_iocb *io_poll_get_single(struct io_kiocb *req) |
|
{ |
|
if (req->opcode == IORING_OP_POLL_ADD) |
|
return &req->poll; |
|
return &req->apoll->poll; |
|
} |
|
|
|
static void io_poll_remove_double(struct io_kiocb *req) |
|
{ |
|
struct io_poll_iocb *poll = io_poll_get_double(req); |
|
|
|
lockdep_assert_held(&req->ctx->completion_lock); |
|
|
|
if (poll && poll->head) { |
|
struct wait_queue_head *head = poll->head; |
|
|
|
spin_lock(&head->lock); |
|
list_del_init(&poll->wait.entry); |
|
if (poll->wait.private) |
|
refcount_dec(&req->refs); |
|
poll->head = NULL; |
|
spin_unlock(&head->lock); |
|
} |
|
} |
|
|
|
static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
io_poll_remove_double(req); |
|
req->poll.done = true; |
|
io_cqring_fill_event(req, error ? error : mangle_poll(mask)); |
|
io_commit_cqring(ctx); |
|
} |
|
|
|
static void io_poll_task_func(struct callback_head *cb) |
|
{ |
|
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct io_kiocb *nxt; |
|
|
|
if (io_poll_rewait(req, &req->poll)) { |
|
spin_unlock_irq(&ctx->completion_lock); |
|
} else { |
|
hash_del(&req->hash_node); |
|
io_poll_complete(req, req->result, 0); |
|
spin_unlock_irq(&ctx->completion_lock); |
|
|
|
nxt = io_put_req_find_next(req); |
|
io_cqring_ev_posted(ctx); |
|
if (nxt) |
|
__io_req_task_submit(nxt); |
|
} |
|
|
|
percpu_ref_put(&ctx->refs); |
|
} |
|
|
|
static int io_poll_double_wake(struct wait_queue_entry *wait, unsigned mode, |
|
int sync, void *key) |
|
{ |
|
struct io_kiocb *req = wait->private; |
|
struct io_poll_iocb *poll = io_poll_get_single(req); |
|
__poll_t mask = key_to_poll(key); |
|
|
|
/* for instances that support it check for an event match first: */ |
|
if (mask && !(mask & poll->events)) |
|
return 0; |
|
|
|
list_del_init(&wait->entry); |
|
|
|
if (poll && poll->head) { |
|
bool done; |
|
|
|
spin_lock(&poll->head->lock); |
|
done = list_empty(&poll->wait.entry); |
|
if (!done) |
|
list_del_init(&poll->wait.entry); |
|
/* make sure double remove sees this as being gone */ |
|
wait->private = NULL; |
|
spin_unlock(&poll->head->lock); |
|
if (!done) { |
|
/* use wait func handler, so it matches the rq type */ |
|
poll->wait.func(&poll->wait, mode, sync, key); |
|
} |
|
} |
|
refcount_dec(&req->refs); |
|
return 1; |
|
} |
|
|
|
static void io_init_poll_iocb(struct io_poll_iocb *poll, __poll_t events, |
|
wait_queue_func_t wake_func) |
|
{ |
|
poll->head = NULL; |
|
poll->done = false; |
|
poll->canceled = false; |
|
poll->events = events; |
|
INIT_LIST_HEAD(&poll->wait.entry); |
|
init_waitqueue_func_entry(&poll->wait, wake_func); |
|
} |
|
|
|
static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt, |
|
struct wait_queue_head *head, |
|
struct io_poll_iocb **poll_ptr) |
|
{ |
|
struct io_kiocb *req = pt->req; |
|
|
|
/* |
|
* If poll->head is already set, it's because the file being polled |
|
* uses multiple waitqueues for poll handling (eg one for read, one |
|
* for write). Setup a separate io_poll_iocb if this happens. |
|
*/ |
|
if (unlikely(poll->head)) { |
|
struct io_poll_iocb *poll_one = poll; |
|
|
|
/* already have a 2nd entry, fail a third attempt */ |
|
if (*poll_ptr) { |
|
pt->error = -EINVAL; |
|
return; |
|
} |
|
/* double add on the same waitqueue head, ignore */ |
|
if (poll->head == head) |
|
return; |
|
poll = kmalloc(sizeof(*poll), GFP_ATOMIC); |
|
if (!poll) { |
|
pt->error = -ENOMEM; |
|
return; |
|
} |
|
io_init_poll_iocb(poll, poll_one->events, io_poll_double_wake); |
|
refcount_inc(&req->refs); |
|
poll->wait.private = req; |
|
*poll_ptr = poll; |
|
} |
|
|
|
pt->error = 0; |
|
poll->head = head; |
|
|
|
if (poll->events & EPOLLEXCLUSIVE) |
|
add_wait_queue_exclusive(head, &poll->wait); |
|
else |
|
add_wait_queue(head, &poll->wait); |
|
} |
|
|
|
static void io_async_queue_proc(struct file *file, struct wait_queue_head *head, |
|
struct poll_table_struct *p) |
|
{ |
|
struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); |
|
struct async_poll *apoll = pt->req->apoll; |
|
|
|
__io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll); |
|
} |
|
|
|
static void io_async_task_func(struct callback_head *cb) |
|
{ |
|
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); |
|
struct async_poll *apoll = req->apoll; |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
trace_io_uring_task_run(req->ctx, req->opcode, req->user_data); |
|
|
|
if (io_poll_rewait(req, &apoll->poll)) { |
|
spin_unlock_irq(&ctx->completion_lock); |
|
percpu_ref_put(&ctx->refs); |
|
return; |
|
} |
|
|
|
/* If req is still hashed, it cannot have been canceled. Don't check. */ |
|
if (hash_hashed(&req->hash_node)) |
|
hash_del(&req->hash_node); |
|
|
|
io_poll_remove_double(req); |
|
spin_unlock_irq(&ctx->completion_lock); |
|
|
|
if (!READ_ONCE(apoll->poll.canceled)) |
|
__io_req_task_submit(req); |
|
else |
|
__io_req_task_cancel(req, -ECANCELED); |
|
|
|
percpu_ref_put(&ctx->refs); |
|
kfree(apoll->double_poll); |
|
kfree(apoll); |
|
} |
|
|
|
static int io_async_wake(struct wait_queue_entry *wait, unsigned mode, int sync, |
|
void *key) |
|
{ |
|
struct io_kiocb *req = wait->private; |
|
struct io_poll_iocb *poll = &req->apoll->poll; |
|
|
|
trace_io_uring_poll_wake(req->ctx, req->opcode, req->user_data, |
|
key_to_poll(key)); |
|
|
|
return __io_async_wake(req, poll, key_to_poll(key), io_async_task_func); |
|
} |
|
|
|
static void io_poll_req_insert(struct io_kiocb *req) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct hlist_head *list; |
|
|
|
list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)]; |
|
hlist_add_head(&req->hash_node, list); |
|
} |
|
|
|
static __poll_t __io_arm_poll_handler(struct io_kiocb *req, |
|
struct io_poll_iocb *poll, |
|
struct io_poll_table *ipt, __poll_t mask, |
|
wait_queue_func_t wake_func) |
|
__acquires(&ctx->completion_lock) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
bool cancel = false; |
|
|
|
INIT_HLIST_NODE(&req->hash_node); |
|
io_init_poll_iocb(poll, mask, wake_func); |
|
poll->file = req->file; |
|
poll->wait.private = req; |
|
|
|
ipt->pt._key = mask; |
|
ipt->req = req; |
|
ipt->error = -EINVAL; |
|
|
|
mask = vfs_poll(req->file, &ipt->pt) & poll->events; |
|
|
|
spin_lock_irq(&ctx->completion_lock); |
|
if (likely(poll->head)) { |
|
spin_lock(&poll->head->lock); |
|
if (unlikely(list_empty(&poll->wait.entry))) { |
|
if (ipt->error) |
|
cancel = true; |
|
ipt->error = 0; |
|
mask = 0; |
|
} |
|
if (mask || ipt->error) |
|
list_del_init(&poll->wait.entry); |
|
else if (cancel) |
|
WRITE_ONCE(poll->canceled, true); |
|
else if (!poll->done) /* actually waiting for an event */ |
|
io_poll_req_insert(req); |
|
spin_unlock(&poll->head->lock); |
|
} |
|
|
|
return mask; |
|
} |
|
|
|
static bool io_arm_poll_handler(struct io_kiocb *req) |
|
{ |
|
const struct io_op_def *def = &io_op_defs[req->opcode]; |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct async_poll *apoll; |
|
struct io_poll_table ipt; |
|
__poll_t mask, ret; |
|
int rw; |
|
|
|
if (!req->file || !file_can_poll(req->file)) |
|
return false; |
|
if (req->flags & REQ_F_POLLED) |
|
return false; |
|
if (def->pollin) |
|
rw = READ; |
|
else if (def->pollout) |
|
rw = WRITE; |
|
else |
|
return false; |
|
/* if we can't nonblock try, then no point in arming a poll handler */ |
|
if (!io_file_supports_async(req->file, rw)) |
|
return false; |
|
|
|
apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC); |
|
if (unlikely(!apoll)) |
|
return false; |
|
apoll->double_poll = NULL; |
|
|
|
req->flags |= REQ_F_POLLED; |
|
req->apoll = apoll; |
|
|
|
mask = 0; |
|
if (def->pollin) |
|
mask |= POLLIN | POLLRDNORM; |
|
if (def->pollout) |
|
mask |= POLLOUT | POLLWRNORM; |
|
|
|
/* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */ |
|
if ((req->opcode == IORING_OP_RECVMSG) && |
|
(req->sr_msg.msg_flags & MSG_ERRQUEUE)) |
|
mask &= ~POLLIN; |
|
|
|
mask |= POLLERR | POLLPRI; |
|
|
|
ipt.pt._qproc = io_async_queue_proc; |
|
|
|
ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask, |
|
io_async_wake); |
|
if (ret || ipt.error) { |
|
io_poll_remove_double(req); |
|
spin_unlock_irq(&ctx->completion_lock); |
|
kfree(apoll->double_poll); |
|
kfree(apoll); |
|
return false; |
|
} |
|
spin_unlock_irq(&ctx->completion_lock); |
|
trace_io_uring_poll_arm(ctx, req->opcode, req->user_data, mask, |
|
apoll->poll.events); |
|
return true; |
|
} |
|
|
|
static bool __io_poll_remove_one(struct io_kiocb *req, |
|
struct io_poll_iocb *poll) |
|
{ |
|
bool do_complete = false; |
|
|
|
spin_lock(&poll->head->lock); |
|
WRITE_ONCE(poll->canceled, true); |
|
if (!list_empty(&poll->wait.entry)) { |
|
list_del_init(&poll->wait.entry); |
|
do_complete = true; |
|
} |
|
spin_unlock(&poll->head->lock); |
|
hash_del(&req->hash_node); |
|
return do_complete; |
|
} |
|
|
|
static bool io_poll_remove_one(struct io_kiocb *req) |
|
{ |
|
bool do_complete; |
|
|
|
io_poll_remove_double(req); |
|
|
|
if (req->opcode == IORING_OP_POLL_ADD) { |
|
do_complete = __io_poll_remove_one(req, &req->poll); |
|
} else { |
|
struct async_poll *apoll = req->apoll; |
|
|
|
/* non-poll requests have submit ref still */ |
|
do_complete = __io_poll_remove_one(req, &apoll->poll); |
|
if (do_complete) { |
|
io_put_req(req); |
|
kfree(apoll->double_poll); |
|
kfree(apoll); |
|
} |
|
} |
|
|
|
if (do_complete) { |
|
io_cqring_fill_event(req, -ECANCELED); |
|
io_commit_cqring(req->ctx); |
|
req_set_fail_links(req); |
|
io_put_req_deferred(req, 1); |
|
} |
|
|
|
return do_complete; |
|
} |
|
|
|
/* |
|
* Returns true if we found and killed one or more poll requests |
|
*/ |
|
static bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk, |
|
struct files_struct *files) |
|
{ |
|
struct hlist_node *tmp; |
|
struct io_kiocb *req; |
|
int posted = 0, i; |
|
|
|
spin_lock_irq(&ctx->completion_lock); |
|
for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) { |
|
struct hlist_head *list; |
|
|
|
list = &ctx->cancel_hash[i]; |
|
hlist_for_each_entry_safe(req, tmp, list, hash_node) { |
|
if (io_match_task(req, tsk, files)) |
|
posted += io_poll_remove_one(req); |
|
} |
|
} |
|
spin_unlock_irq(&ctx->completion_lock); |
|
|
|
if (posted) |
|
io_cqring_ev_posted(ctx); |
|
|
|
return posted != 0; |
|
} |
|
|
|
static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr) |
|
{ |
|
struct hlist_head *list; |
|
struct io_kiocb *req; |
|
|
|
list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)]; |
|
hlist_for_each_entry(req, list, hash_node) { |
|
if (sqe_addr != req->user_data) |
|
continue; |
|
if (io_poll_remove_one(req)) |
|
return 0; |
|
return -EALREADY; |
|
} |
|
|
|
return -ENOENT; |
|
} |
|
|
|
static int io_poll_remove_prep(struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index || |
|
sqe->poll_events) |
|
return -EINVAL; |
|
|
|
req->poll_remove.addr = READ_ONCE(sqe->addr); |
|
return 0; |
|
} |
|
|
|
/* |
|
* Find a running poll command that matches one specified in sqe->addr, |
|
* and remove it if found. |
|
*/ |
|
static int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
int ret; |
|
|
|
spin_lock_irq(&ctx->completion_lock); |
|
ret = io_poll_cancel(ctx, req->poll_remove.addr); |
|
spin_unlock_irq(&ctx->completion_lock); |
|
|
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_req_complete(req, ret); |
|
return 0; |
|
} |
|
|
|
static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, |
|
void *key) |
|
{ |
|
struct io_kiocb *req = wait->private; |
|
struct io_poll_iocb *poll = &req->poll; |
|
|
|
return __io_async_wake(req, poll, key_to_poll(key), io_poll_task_func); |
|
} |
|
|
|
static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head, |
|
struct poll_table_struct *p) |
|
{ |
|
struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); |
|
|
|
__io_queue_proc(&pt->req->poll, pt, head, (struct io_poll_iocb **) &pt->req->async_data); |
|
} |
|
|
|
static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_poll_iocb *poll = &req->poll; |
|
u32 events; |
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index) |
|
return -EINVAL; |
|
|
|
events = READ_ONCE(sqe->poll32_events); |
|
#ifdef __BIG_ENDIAN |
|
events = swahw32(events); |
|
#endif |
|
poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP | |
|
(events & EPOLLEXCLUSIVE); |
|
return 0; |
|
} |
|
|
|
static int io_poll_add(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_poll_iocb *poll = &req->poll; |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct io_poll_table ipt; |
|
__poll_t mask; |
|
|
|
ipt.pt._qproc = io_poll_queue_proc; |
|
|
|
mask = __io_arm_poll_handler(req, &req->poll, &ipt, poll->events, |
|
io_poll_wake); |
|
|
|
if (mask) { /* no async, we'd stolen it */ |
|
ipt.error = 0; |
|
io_poll_complete(req, mask, 0); |
|
} |
|
spin_unlock_irq(&ctx->completion_lock); |
|
|
|
if (mask) { |
|
io_cqring_ev_posted(ctx); |
|
io_put_req(req); |
|
} |
|
return ipt.error; |
|
} |
|
|
|
static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer) |
|
{ |
|
struct io_timeout_data *data = container_of(timer, |
|
struct io_timeout_data, timer); |
|
struct io_kiocb *req = data->req; |
|
struct io_ring_ctx *ctx = req->ctx; |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&ctx->completion_lock, flags); |
|
list_del_init(&req->timeout.list); |
|
atomic_set(&req->ctx->cq_timeouts, |
|
atomic_read(&req->ctx->cq_timeouts) + 1); |
|
|
|
io_cqring_fill_event(req, -ETIME); |
|
io_commit_cqring(ctx); |
|
spin_unlock_irqrestore(&ctx->completion_lock, flags); |
|
|
|
io_cqring_ev_posted(ctx); |
|
req_set_fail_links(req); |
|
io_put_req(req); |
|
return HRTIMER_NORESTART; |
|
} |
|
|
|
static struct io_kiocb *io_timeout_extract(struct io_ring_ctx *ctx, |
|
__u64 user_data) |
|
{ |
|
struct io_timeout_data *io; |
|
struct io_kiocb *req; |
|
int ret = -ENOENT; |
|
|
|
list_for_each_entry(req, &ctx->timeout_list, timeout.list) { |
|
if (user_data == req->user_data) { |
|
ret = 0; |
|
break; |
|
} |
|
} |
|
|
|
if (ret == -ENOENT) |
|
return ERR_PTR(ret); |
|
|
|
io = req->async_data; |
|
ret = hrtimer_try_to_cancel(&io->timer); |
|
if (ret == -1) |
|
return ERR_PTR(-EALREADY); |
|
list_del_init(&req->timeout.list); |
|
return req; |
|
} |
|
|
|
static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data) |
|
{ |
|
struct io_kiocb *req = io_timeout_extract(ctx, user_data); |
|
|
|
if (IS_ERR(req)) |
|
return PTR_ERR(req); |
|
|
|
req_set_fail_links(req); |
|
io_cqring_fill_event(req, -ECANCELED); |
|
io_put_req_deferred(req, 1); |
|
return 0; |
|
} |
|
|
|
static int io_timeout_update(struct io_ring_ctx *ctx, __u64 user_data, |
|
struct timespec64 *ts, enum hrtimer_mode mode) |
|
{ |
|
struct io_kiocb *req = io_timeout_extract(ctx, user_data); |
|
struct io_timeout_data *data; |
|
|
|
if (IS_ERR(req)) |
|
return PTR_ERR(req); |
|
|
|
req->timeout.off = 0; /* noseq */ |
|
data = req->async_data; |
|
list_add_tail(&req->timeout.list, &ctx->timeout_list); |
|
hrtimer_init(&data->timer, CLOCK_MONOTONIC, mode); |
|
data->timer.function = io_timeout_fn; |
|
hrtimer_start(&data->timer, timespec64_to_ktime(*ts), mode); |
|
return 0; |
|
} |
|
|
|
static int io_timeout_remove_prep(struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_timeout_rem *tr = &req->timeout_rem; |
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT))) |
|
return -EINVAL; |
|
if (sqe->ioprio || sqe->buf_index || sqe->len) |
|
return -EINVAL; |
|
|
|
tr->addr = READ_ONCE(sqe->addr); |
|
tr->flags = READ_ONCE(sqe->timeout_flags); |
|
if (tr->flags & IORING_TIMEOUT_UPDATE) { |
|
if (tr->flags & ~(IORING_TIMEOUT_UPDATE|IORING_TIMEOUT_ABS)) |
|
return -EINVAL; |
|
if (get_timespec64(&tr->ts, u64_to_user_ptr(sqe->addr2))) |
|
return -EFAULT; |
|
} else if (tr->flags) { |
|
/* timeout removal doesn't support flags */ |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static inline enum hrtimer_mode io_translate_timeout_mode(unsigned int flags) |
|
{ |
|
return (flags & IORING_TIMEOUT_ABS) ? HRTIMER_MODE_ABS |
|
: HRTIMER_MODE_REL; |
|
} |
|
|
|
/* |
|
* Remove or update an existing timeout command |
|
*/ |
|
static int io_timeout_remove(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_timeout_rem *tr = &req->timeout_rem; |
|
struct io_ring_ctx *ctx = req->ctx; |
|
int ret; |
|
|
|
spin_lock_irq(&ctx->completion_lock); |
|
if (!(req->timeout_rem.flags & IORING_TIMEOUT_UPDATE)) |
|
ret = io_timeout_cancel(ctx, tr->addr); |
|
else |
|
ret = io_timeout_update(ctx, tr->addr, &tr->ts, |
|
io_translate_timeout_mode(tr->flags)); |
|
|
|
io_cqring_fill_event(req, ret); |
|
io_commit_cqring(ctx); |
|
spin_unlock_irq(&ctx->completion_lock); |
|
io_cqring_ev_posted(ctx); |
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_put_req(req); |
|
return 0; |
|
} |
|
|
|
static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
|
bool is_timeout_link) |
|
{ |
|
struct io_timeout_data *data; |
|
unsigned flags; |
|
u32 off = READ_ONCE(sqe->off); |
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
if (sqe->ioprio || sqe->buf_index || sqe->len != 1) |
|
return -EINVAL; |
|
if (off && is_timeout_link) |
|
return -EINVAL; |
|
flags = READ_ONCE(sqe->timeout_flags); |
|
if (flags & ~IORING_TIMEOUT_ABS) |
|
return -EINVAL; |
|
|
|
req->timeout.off = off; |
|
|
|
if (!req->async_data && io_alloc_async_data(req)) |
|
return -ENOMEM; |
|
|
|
data = req->async_data; |
|
data->req = req; |
|
|
|
if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr))) |
|
return -EFAULT; |
|
|
|
data->mode = io_translate_timeout_mode(flags); |
|
hrtimer_init(&data->timer, CLOCK_MONOTONIC, data->mode); |
|
if (is_timeout_link) |
|
io_req_track_inflight(req); |
|
return 0; |
|
} |
|
|
|
static int io_timeout(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct io_timeout_data *data = req->async_data; |
|
struct list_head *entry; |
|
u32 tail, off = req->timeout.off; |
|
|
|
spin_lock_irq(&ctx->completion_lock); |
|
|
|
/* |
|
* sqe->off holds how many events that need to occur for this |
|
* timeout event to be satisfied. If it isn't set, then this is |
|
* a pure timeout request, sequence isn't used. |
|
*/ |
|
if (io_is_timeout_noseq(req)) { |
|
entry = ctx->timeout_list.prev; |
|
goto add; |
|
} |
|
|
|
tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts); |
|
req->timeout.target_seq = tail + off; |
|
|
|
/* Update the last seq here in case io_flush_timeouts() hasn't. |
|
* This is safe because ->completion_lock is held, and submissions |
|
* and completions are never mixed in the same ->completion_lock section. |
|
*/ |
|
ctx->cq_last_tm_flush = tail; |
|
|
|
/* |
|
* Insertion sort, ensuring the first entry in the list is always |
|
* the one we need first. |
|
*/ |
|
list_for_each_prev(entry, &ctx->timeout_list) { |
|
struct io_kiocb *nxt = list_entry(entry, struct io_kiocb, |
|
timeout.list); |
|
|
|
if (io_is_timeout_noseq(nxt)) |
|
continue; |
|
/* nxt.seq is behind @tail, otherwise would've been completed */ |
|
if (off >= nxt->timeout.target_seq - tail) |
|
break; |
|
} |
|
add: |
|
list_add(&req->timeout.list, entry); |
|
data->timer.function = io_timeout_fn; |
|
hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode); |
|
spin_unlock_irq(&ctx->completion_lock); |
|
return 0; |
|
} |
|
|
|
struct io_cancel_data { |
|
struct io_ring_ctx *ctx; |
|
u64 user_data; |
|
}; |
|
|
|
static bool io_cancel_cb(struct io_wq_work *work, void *data) |
|
{ |
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work); |
|
struct io_cancel_data *cd = data; |
|
|
|
return req->ctx == cd->ctx && req->user_data == cd->user_data; |
|
} |
|
|
|
static int io_async_cancel_one(struct io_uring_task *tctx, u64 user_data, |
|
struct io_ring_ctx *ctx) |
|
{ |
|
struct io_cancel_data data = { .ctx = ctx, .user_data = user_data, }; |
|
enum io_wq_cancel cancel_ret; |
|
int ret = 0; |
|
|
|
if (!tctx || !tctx->io_wq) |
|
return -ENOENT; |
|
|
|
cancel_ret = io_wq_cancel_cb(tctx->io_wq, io_cancel_cb, &data, false); |
|
switch (cancel_ret) { |
|
case IO_WQ_CANCEL_OK: |
|
ret = 0; |
|
break; |
|
case IO_WQ_CANCEL_RUNNING: |
|
ret = -EALREADY; |
|
break; |
|
case IO_WQ_CANCEL_NOTFOUND: |
|
ret = -ENOENT; |
|
break; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static void io_async_find_and_cancel(struct io_ring_ctx *ctx, |
|
struct io_kiocb *req, __u64 sqe_addr, |
|
int success_ret) |
|
{ |
|
unsigned long flags; |
|
int ret; |
|
|
|
ret = io_async_cancel_one(req->task->io_uring, sqe_addr, ctx); |
|
if (ret != -ENOENT) { |
|
spin_lock_irqsave(&ctx->completion_lock, flags); |
|
goto done; |
|
} |
|
|
|
spin_lock_irqsave(&ctx->completion_lock, flags); |
|
ret = io_timeout_cancel(ctx, sqe_addr); |
|
if (ret != -ENOENT) |
|
goto done; |
|
ret = io_poll_cancel(ctx, sqe_addr); |
|
done: |
|
if (!ret) |
|
ret = success_ret; |
|
io_cqring_fill_event(req, ret); |
|
io_commit_cqring(ctx); |
|
spin_unlock_irqrestore(&ctx->completion_lock, flags); |
|
io_cqring_ev_posted(ctx); |
|
|
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_put_req(req); |
|
} |
|
|
|
static int io_async_cancel_prep(struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
|
return -EINVAL; |
|
if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT))) |
|
return -EINVAL; |
|
if (sqe->ioprio || sqe->off || sqe->len || sqe->cancel_flags) |
|
return -EINVAL; |
|
|
|
req->cancel.addr = READ_ONCE(sqe->addr); |
|
return 0; |
|
} |
|
|
|
static int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
u64 sqe_addr = req->cancel.addr; |
|
struct io_tctx_node *node; |
|
int ret; |
|
|
|
/* tasks should wait for their io-wq threads, so safe w/o sync */ |
|
ret = io_async_cancel_one(req->task->io_uring, sqe_addr, ctx); |
|
spin_lock_irq(&ctx->completion_lock); |
|
if (ret != -ENOENT) |
|
goto done; |
|
ret = io_timeout_cancel(ctx, sqe_addr); |
|
if (ret != -ENOENT) |
|
goto done; |
|
ret = io_poll_cancel(ctx, sqe_addr); |
|
if (ret != -ENOENT) |
|
goto done; |
|
spin_unlock_irq(&ctx->completion_lock); |
|
|
|
/* slow path, try all io-wq's */ |
|
io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK)); |
|
ret = -ENOENT; |
|
list_for_each_entry(node, &ctx->tctx_list, ctx_node) { |
|
struct io_uring_task *tctx = node->task->io_uring; |
|
|
|
if (!tctx || !tctx->io_wq) |
|
continue; |
|
ret = io_async_cancel_one(tctx, req->cancel.addr, ctx); |
|
if (ret != -ENOENT) |
|
break; |
|
} |
|
io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK)); |
|
|
|
spin_lock_irq(&ctx->completion_lock); |
|
done: |
|
io_cqring_fill_event(req, ret); |
|
io_commit_cqring(ctx); |
|
spin_unlock_irq(&ctx->completion_lock); |
|
io_cqring_ev_posted(ctx); |
|
|
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
io_put_req(req); |
|
return 0; |
|
} |
|
|
|
static int io_rsrc_update_prep(struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
if (unlikely(req->ctx->flags & IORING_SETUP_SQPOLL)) |
|
return -EINVAL; |
|
if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT))) |
|
return -EINVAL; |
|
if (sqe->ioprio || sqe->rw_flags) |
|
return -EINVAL; |
|
|
|
req->rsrc_update.offset = READ_ONCE(sqe->off); |
|
req->rsrc_update.nr_args = READ_ONCE(sqe->len); |
|
if (!req->rsrc_update.nr_args) |
|
return -EINVAL; |
|
req->rsrc_update.arg = READ_ONCE(sqe->addr); |
|
return 0; |
|
} |
|
|
|
static int io_files_update(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct io_uring_rsrc_update up; |
|
int ret; |
|
|
|
if (issue_flags & IO_URING_F_NONBLOCK) |
|
return -EAGAIN; |
|
|
|
up.offset = req->rsrc_update.offset; |
|
up.data = req->rsrc_update.arg; |
|
|
|
mutex_lock(&ctx->uring_lock); |
|
ret = __io_sqe_files_update(ctx, &up, req->rsrc_update.nr_args); |
|
mutex_unlock(&ctx->uring_lock); |
|
|
|
if (ret < 0) |
|
req_set_fail_links(req); |
|
__io_req_complete(req, issue_flags, ret, 0); |
|
return 0; |
|
} |
|
|
|
static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
|
{ |
|
switch (req->opcode) { |
|
case IORING_OP_NOP: |
|
return 0; |
|
case IORING_OP_READV: |
|
case IORING_OP_READ_FIXED: |
|
case IORING_OP_READ: |
|
return io_read_prep(req, sqe); |
|
case IORING_OP_WRITEV: |
|
case IORING_OP_WRITE_FIXED: |
|
case IORING_OP_WRITE: |
|
return io_write_prep(req, sqe); |
|
case IORING_OP_POLL_ADD: |
|
return io_poll_add_prep(req, sqe); |
|
case IORING_OP_POLL_REMOVE: |
|
return io_poll_remove_prep(req, sqe); |
|
case IORING_OP_FSYNC: |
|
return io_fsync_prep(req, sqe); |
|
case IORING_OP_SYNC_FILE_RANGE: |
|
return io_sfr_prep(req, sqe); |
|
case IORING_OP_SENDMSG: |
|
case IORING_OP_SEND: |
|
return io_sendmsg_prep(req, sqe); |
|
case IORING_OP_RECVMSG: |
|
case IORING_OP_RECV: |
|
return io_recvmsg_prep(req, sqe); |
|
case IORING_OP_CONNECT: |
|
return io_connect_prep(req, sqe); |
|
case IORING_OP_TIMEOUT: |
|
return io_timeout_prep(req, sqe, false); |
|
case IORING_OP_TIMEOUT_REMOVE: |
|
return io_timeout_remove_prep(req, sqe); |
|
case IORING_OP_ASYNC_CANCEL: |
|
return io_async_cancel_prep(req, sqe); |
|
case IORING_OP_LINK_TIMEOUT: |
|
return io_timeout_prep(req, sqe, true); |
|
case IORING_OP_ACCEPT: |
|
return io_accept_prep(req, sqe); |
|
case IORING_OP_FALLOCATE: |
|
return io_fallocate_prep(req, sqe); |
|
case IORING_OP_OPENAT: |
|
return io_openat_prep(req, sqe); |
|
case IORING_OP_CLOSE: |
|
return io_close_prep(req, sqe); |
|
case IORING_OP_FILES_UPDATE: |
|
return io_rsrc_update_prep(req, sqe); |
|
case IORING_OP_STATX: |
|
return io_statx_prep(req, sqe); |
|
case IORING_OP_FADVISE: |
|
return io_fadvise_prep(req, sqe); |
|
case IORING_OP_MADVISE: |
|
return io_madvise_prep(req, sqe); |
|
case IORING_OP_OPENAT2: |
|
return io_openat2_prep(req, sqe); |
|
case IORING_OP_EPOLL_CTL: |
|
return io_epoll_ctl_prep(req, sqe); |
|
case IORING_OP_SPLICE: |
|
return io_splice_prep(req, sqe); |
|
case IORING_OP_PROVIDE_BUFFERS: |
|
return io_provide_buffers_prep(req, sqe); |
|
case IORING_OP_REMOVE_BUFFERS: |
|
return io_remove_buffers_prep(req, sqe); |
|
case IORING_OP_TEE: |
|
return io_tee_prep(req, sqe); |
|
case IORING_OP_SHUTDOWN: |
|
return io_shutdown_prep(req, sqe); |
|
case IORING_OP_RENAMEAT: |
|
return io_renameat_prep(req, sqe); |
|
case IORING_OP_UNLINKAT: |
|
return io_unlinkat_prep(req, sqe); |
|
} |
|
|
|
printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n", |
|
req->opcode); |
|
return-EINVAL; |
|
} |
|
|
|
static int io_req_prep_async(struct io_kiocb *req) |
|
{ |
|
switch (req->opcode) { |
|
case IORING_OP_READV: |
|
case IORING_OP_READ_FIXED: |
|
case IORING_OP_READ: |
|
return io_rw_prep_async(req, READ); |
|
case IORING_OP_WRITEV: |
|
case IORING_OP_WRITE_FIXED: |
|
case IORING_OP_WRITE: |
|
return io_rw_prep_async(req, WRITE); |
|
case IORING_OP_SENDMSG: |
|
case IORING_OP_SEND: |
|
return io_sendmsg_prep_async(req); |
|
case IORING_OP_RECVMSG: |
|
case IORING_OP_RECV: |
|
return io_recvmsg_prep_async(req); |
|
case IORING_OP_CONNECT: |
|
return io_connect_prep_async(req); |
|
} |
|
return 0; |
|
} |
|
|
|
static int io_req_defer_prep(struct io_kiocb *req) |
|
{ |
|
if (!io_op_defs[req->opcode].needs_async_data) |
|
return 0; |
|
/* some opcodes init it during the inital prep */ |
|
if (req->async_data) |
|
return 0; |
|
if (__io_alloc_async_data(req)) |
|
return -EAGAIN; |
|
return io_req_prep_async(req); |
|
} |
|
|
|
static u32 io_get_sequence(struct io_kiocb *req) |
|
{ |
|
struct io_kiocb *pos; |
|
struct io_ring_ctx *ctx = req->ctx; |
|
u32 total_submitted, nr_reqs = 0; |
|
|
|
io_for_each_link(pos, req) |
|
nr_reqs++; |
|
|
|
total_submitted = ctx->cached_sq_head - ctx->cached_sq_dropped; |
|
return total_submitted - nr_reqs; |
|
} |
|
|
|
static int io_req_defer(struct io_kiocb *req) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct io_defer_entry *de; |
|
int ret; |
|
u32 seq; |
|
|
|
/* Still need defer if there is pending req in defer list. */ |
|
if (likely(list_empty_careful(&ctx->defer_list) && |
|
!(req->flags & REQ_F_IO_DRAIN))) |
|
return 0; |
|
|
|
seq = io_get_sequence(req); |
|
/* Still a chance to pass the sequence check */ |
|
if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list)) |
|
return 0; |
|
|
|
ret = io_req_defer_prep(req); |
|
if (ret) |
|
return ret; |
|
io_prep_async_link(req); |
|
de = kmalloc(sizeof(*de), GFP_KERNEL); |
|
if (!de) |
|
return -ENOMEM; |
|
|
|
spin_lock_irq(&ctx->completion_lock); |
|
if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) { |
|
spin_unlock_irq(&ctx->completion_lock); |
|
kfree(de); |
|
io_queue_async_work(req); |
|
return -EIOCBQUEUED; |
|
} |
|
|
|
trace_io_uring_defer(ctx, req, req->user_data); |
|
de->req = req; |
|
de->seq = seq; |
|
list_add_tail(&de->list, &ctx->defer_list); |
|
spin_unlock_irq(&ctx->completion_lock); |
|
return -EIOCBQUEUED; |
|
} |
|
|
|
static void __io_clean_op(struct io_kiocb *req) |
|
{ |
|
if (req->flags & REQ_F_BUFFER_SELECTED) { |
|
switch (req->opcode) { |
|
case IORING_OP_READV: |
|
case IORING_OP_READ_FIXED: |
|
case IORING_OP_READ: |
|
kfree((void *)(unsigned long)req->rw.addr); |
|
break; |
|
case IORING_OP_RECVMSG: |
|
case IORING_OP_RECV: |
|
kfree(req->sr_msg.kbuf); |
|
break; |
|
} |
|
req->flags &= ~REQ_F_BUFFER_SELECTED; |
|
} |
|
|
|
if (req->flags & REQ_F_NEED_CLEANUP) { |
|
switch (req->opcode) { |
|
case IORING_OP_READV: |
|
case IORING_OP_READ_FIXED: |
|
case IORING_OP_READ: |
|
case IORING_OP_WRITEV: |
|
case IORING_OP_WRITE_FIXED: |
|
case IORING_OP_WRITE: { |
|
struct io_async_rw *io = req->async_data; |
|
if (io->free_iovec) |
|
kfree(io->free_iovec); |
|
break; |
|
} |
|
case IORING_OP_RECVMSG: |
|
case IORING_OP_SENDMSG: { |
|
struct io_async_msghdr *io = req->async_data; |
|
|
|
kfree(io->free_iov); |
|
break; |
|
} |
|
case IORING_OP_SPLICE: |
|
case IORING_OP_TEE: |
|
io_put_file(req, req->splice.file_in, |
|
(req->splice.flags & SPLICE_F_FD_IN_FIXED)); |
|
break; |
|
case IORING_OP_OPENAT: |
|
case IORING_OP_OPENAT2: |
|
if (req->open.filename) |
|
putname(req->open.filename); |
|
break; |
|
case IORING_OP_RENAMEAT: |
|
putname(req->rename.oldpath); |
|
putname(req->rename.newpath); |
|
break; |
|
case IORING_OP_UNLINKAT: |
|
putname(req->unlink.filename); |
|
break; |
|
} |
|
req->flags &= ~REQ_F_NEED_CLEANUP; |
|
} |
|
} |
|
|
|
static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
const struct cred *creds = NULL; |
|
int ret; |
|
|
|
if (req->work.creds && req->work.creds != current_cred()) |
|
creds = override_creds(req->work.creds); |
|
|
|
switch (req->opcode) { |
|
case IORING_OP_NOP: |
|
ret = io_nop(req, issue_flags); |
|
break; |
|
case IORING_OP_READV: |
|
case IORING_OP_READ_FIXED: |
|
case IORING_OP_READ: |
|
ret = io_read(req, issue_flags); |
|
break; |
|
case IORING_OP_WRITEV: |
|
case IORING_OP_WRITE_FIXED: |
|
case IORING_OP_WRITE: |
|
ret = io_write(req, issue_flags); |
|
break; |
|
case IORING_OP_FSYNC: |
|
ret = io_fsync(req, issue_flags); |
|
break; |
|
case IORING_OP_POLL_ADD: |
|
ret = io_poll_add(req, issue_flags); |
|
break; |
|
case IORING_OP_POLL_REMOVE: |
|
ret = io_poll_remove(req, issue_flags); |
|
break; |
|
case IORING_OP_SYNC_FILE_RANGE: |
|
ret = io_sync_file_range(req, issue_flags); |
|
break; |
|
case IORING_OP_SENDMSG: |
|
ret = io_sendmsg(req, issue_flags); |
|
break; |
|
case IORING_OP_SEND: |
|
ret = io_send(req, issue_flags); |
|
break; |
|
case IORING_OP_RECVMSG: |
|
ret = io_recvmsg(req, issue_flags); |
|
break; |
|
case IORING_OP_RECV: |
|
ret = io_recv(req, issue_flags); |
|
break; |
|
case IORING_OP_TIMEOUT: |
|
ret = io_timeout(req, issue_flags); |
|
break; |
|
case IORING_OP_TIMEOUT_REMOVE: |
|
ret = io_timeout_remove(req, issue_flags); |
|
break; |
|
case IORING_OP_ACCEPT: |
|
ret = io_accept(req, issue_flags); |
|
break; |
|
case IORING_OP_CONNECT: |
|
ret = io_connect(req, issue_flags); |
|
break; |
|
case IORING_OP_ASYNC_CANCEL: |
|
ret = io_async_cancel(req, issue_flags); |
|
break; |
|
case IORING_OP_FALLOCATE: |
|
ret = io_fallocate(req, issue_flags); |
|
break; |
|
case IORING_OP_OPENAT: |
|
ret = io_openat(req, issue_flags); |
|
break; |
|
case IORING_OP_CLOSE: |
|
ret = io_close(req, issue_flags); |
|
break; |
|
case IORING_OP_FILES_UPDATE: |
|
ret = io_files_update(req, issue_flags); |
|
break; |
|
case IORING_OP_STATX: |
|
ret = io_statx(req, issue_flags); |
|
break; |
|
case IORING_OP_FADVISE: |
|
ret = io_fadvise(req, issue_flags); |
|
break; |
|
case IORING_OP_MADVISE: |
|
ret = io_madvise(req, issue_flags); |
|
break; |
|
case IORING_OP_OPENAT2: |
|
ret = io_openat2(req, issue_flags); |
|
break; |
|
case IORING_OP_EPOLL_CTL: |
|
ret = io_epoll_ctl(req, issue_flags); |
|
break; |
|
case IORING_OP_SPLICE: |
|
ret = io_splice(req, issue_flags); |
|
break; |
|
case IORING_OP_PROVIDE_BUFFERS: |
|
ret = io_provide_buffers(req, issue_flags); |
|
break; |
|
case IORING_OP_REMOVE_BUFFERS: |
|
ret = io_remove_buffers(req, issue_flags); |
|
break; |
|
case IORING_OP_TEE: |
|
ret = io_tee(req, issue_flags); |
|
break; |
|
case IORING_OP_SHUTDOWN: |
|
ret = io_shutdown(req, issue_flags); |
|
break; |
|
case IORING_OP_RENAMEAT: |
|
ret = io_renameat(req, issue_flags); |
|
break; |
|
case IORING_OP_UNLINKAT: |
|
ret = io_unlinkat(req, issue_flags); |
|
break; |
|
default: |
|
ret = -EINVAL; |
|
break; |
|
} |
|
|
|
if (creds) |
|
revert_creds(creds); |
|
|
|
if (ret) |
|
return ret; |
|
|
|
/* If the op doesn't have a file, we're not polling for it */ |
|
if ((ctx->flags & IORING_SETUP_IOPOLL) && req->file) { |
|
const bool in_async = io_wq_current_is_worker(); |
|
|
|
/* workqueue context doesn't hold uring_lock, grab it now */ |
|
if (in_async) |
|
mutex_lock(&ctx->uring_lock); |
|
|
|
io_iopoll_req_issued(req, in_async); |
|
|
|
if (in_async) |
|
mutex_unlock(&ctx->uring_lock); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void io_wq_submit_work(struct io_wq_work *work) |
|
{ |
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work); |
|
struct io_kiocb *timeout; |
|
int ret = 0; |
|
|
|
timeout = io_prep_linked_timeout(req); |
|
if (timeout) |
|
io_queue_linked_timeout(timeout); |
|
|
|
if (work->flags & IO_WQ_WORK_CANCEL) |
|
ret = -ECANCELED; |
|
|
|
if (!ret) { |
|
do { |
|
ret = io_issue_sqe(req, 0); |
|
/* |
|
* We can get EAGAIN for polled IO even though we're |
|
* forcing a sync submission from here, since we can't |
|
* wait for request slots on the block side. |
|
*/ |
|
if (ret != -EAGAIN) |
|
break; |
|
cond_resched(); |
|
} while (1); |
|
} |
|
|
|
/* avoid locking problems by failing it from a clean context */ |
|
if (ret) { |
|
/* io-wq is going to take one down */ |
|
refcount_inc(&req->refs); |
|
io_req_task_queue_fail(req, ret); |
|
} |
|
} |
|
|
|
static inline struct file *io_file_from_index(struct io_ring_ctx *ctx, |
|
int index) |
|
{ |
|
struct fixed_rsrc_table *table; |
|
|
|
table = &ctx->file_data->table[index >> IORING_FILE_TABLE_SHIFT]; |
|
return table->files[index & IORING_FILE_TABLE_MASK]; |
|
} |
|
|
|
static struct file *io_file_get(struct io_submit_state *state, |
|
struct io_kiocb *req, int fd, bool fixed) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct file *file; |
|
|
|
if (fixed) { |
|
if (unlikely((unsigned int)fd >= ctx->nr_user_files)) |
|
return NULL; |
|
fd = array_index_nospec(fd, ctx->nr_user_files); |
|
file = io_file_from_index(ctx, fd); |
|
io_set_resource_node(req); |
|
} else { |
|
trace_io_uring_file_get(ctx, fd); |
|
file = __io_file_get(state, fd); |
|
} |
|
|
|
if (file && unlikely(file->f_op == &io_uring_fops)) |
|
io_req_track_inflight(req); |
|
return file; |
|
} |
|
|
|
static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer) |
|
{ |
|
struct io_timeout_data *data = container_of(timer, |
|
struct io_timeout_data, timer); |
|
struct io_kiocb *prev, *req = data->req; |
|
struct io_ring_ctx *ctx = req->ctx; |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&ctx->completion_lock, flags); |
|
prev = req->timeout.head; |
|
req->timeout.head = NULL; |
|
|
|
/* |
|
* We don't expect the list to be empty, that will only happen if we |
|
* race with the completion of the linked work. |
|
*/ |
|
if (prev && refcount_inc_not_zero(&prev->refs)) |
|
io_remove_next_linked(prev); |
|
else |
|
prev = NULL; |
|
spin_unlock_irqrestore(&ctx->completion_lock, flags); |
|
|
|
if (prev) { |
|
io_async_find_and_cancel(ctx, req, prev->user_data, -ETIME); |
|
io_put_req_deferred(prev, 1); |
|
} else { |
|
io_req_complete_post(req, -ETIME, 0); |
|
io_put_req_deferred(req, 1); |
|
} |
|
return HRTIMER_NORESTART; |
|
} |
|
|
|
static void __io_queue_linked_timeout(struct io_kiocb *req) |
|
{ |
|
/* |
|
* If the back reference is NULL, then our linked request finished |
|
* before we got a chance to setup the timer |
|
*/ |
|
if (req->timeout.head) { |
|
struct io_timeout_data *data = req->async_data; |
|
|
|
data->timer.function = io_link_timeout_fn; |
|
hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), |
|
data->mode); |
|
} |
|
} |
|
|
|
static void io_queue_linked_timeout(struct io_kiocb *req) |
|
{ |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
spin_lock_irq(&ctx->completion_lock); |
|
__io_queue_linked_timeout(req); |
|
spin_unlock_irq(&ctx->completion_lock); |
|
|
|
/* drop submission reference */ |
|
io_put_req(req); |
|
} |
|
|
|
static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req) |
|
{ |
|
struct io_kiocb *nxt = req->link; |
|
|
|
if (!nxt || (req->flags & REQ_F_LINK_TIMEOUT) || |
|
nxt->opcode != IORING_OP_LINK_TIMEOUT) |
|
return NULL; |
|
|
|
nxt->timeout.head = req; |
|
nxt->flags |= REQ_F_LTIMEOUT_ACTIVE; |
|
req->flags |= REQ_F_LINK_TIMEOUT; |
|
return nxt; |
|
} |
|
|
|
static void __io_queue_sqe(struct io_kiocb *req) |
|
{ |
|
struct io_kiocb *linked_timeout = io_prep_linked_timeout(req); |
|
int ret; |
|
|
|
ret = io_issue_sqe(req, IO_URING_F_NONBLOCK|IO_URING_F_COMPLETE_DEFER); |
|
|
|
/* |
|
* We async punt it if the file wasn't marked NOWAIT, or if the file |
|
* doesn't support non-blocking read/write attempts |
|
*/ |
|
if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) { |
|
if (!io_arm_poll_handler(req)) { |
|
/* |
|
* Queued up for async execution, worker will release |
|
* submit reference when the iocb is actually submitted. |
|
*/ |
|
io_queue_async_work(req); |
|
} |
|
} else if (likely(!ret)) { |
|
/* drop submission reference */ |
|
if (req->flags & REQ_F_COMPLETE_INLINE) { |
|
struct io_ring_ctx *ctx = req->ctx; |
|
struct io_comp_state *cs = &ctx->submit_state.comp; |
|
|
|
cs->reqs[cs->nr++] = req; |
|
if (cs->nr == ARRAY_SIZE(cs->reqs)) |
|
io_submit_flush_completions(cs, ctx); |
|
} else { |
|
io_put_req(req); |
|
} |
|
} else { |
|
req_set_fail_links(req); |
|
io_put_req(req); |
|
io_req_complete(req, ret); |
|
} |
|
if (linked_timeout) |
|
io_queue_linked_timeout(linked_timeout); |
|
} |
|
|
|
static void io_queue_sqe(struct io_kiocb *req) |
|
{ |
|
int ret; |
|
|
|
ret = io_req_defer(req); |
|
if (ret) { |
|
if (ret != -EIOCBQUEUED) { |
|
fail_req: |
|
req_set_fail_links(req); |
|
io_put_req(req); |
|
io_req_complete(req, ret); |
|
} |
|
} else if (req->flags & REQ_F_FORCE_ASYNC) { |
|
ret = io_req_defer_prep(req); |
|
if (unlikely(ret)) |
|
goto fail_req; |
|
io_queue_async_work(req); |
|
} else { |
|
__io_queue_sqe(req); |
|
} |
|
} |
|
|
|
/* |
|
* Check SQE restrictions (opcode and flags). |
|
* |
|
* Returns 'true' if SQE is allowed, 'false' otherwise. |
|
*/ |
|
static inline bool io_check_restriction(struct io_ring_ctx *ctx, |
|
struct io_kiocb *req, |
|
unsigned int sqe_flags) |
|
{ |
|
if (!ctx->restricted) |
|
return true; |
|
|
|
if (!test_bit(req->opcode, ctx->restrictions.sqe_op)) |
|
return false; |
|
|
|
if ((sqe_flags & ctx->restrictions.sqe_flags_required) != |
|
ctx->restrictions.sqe_flags_required) |
|
return false; |
|
|
|
if (sqe_flags & ~(ctx->restrictions.sqe_flags_allowed | |
|
ctx->restrictions.sqe_flags_required)) |
|
return false; |
|
|
|
return true; |
|
} |
|
|
|
static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_submit_state *state; |
|
unsigned int sqe_flags; |
|
int personality, ret = 0; |
|
|
|
req->opcode = READ_ONCE(sqe->opcode); |
|
/* same numerical values with corresponding REQ_F_*, safe to copy */ |
|
req->flags = sqe_flags = READ_ONCE(sqe->flags); |
|
req->user_data = READ_ONCE(sqe->user_data); |
|
req->async_data = NULL; |
|
req->file = NULL; |
|
req->ctx = ctx; |
|
req->link = NULL; |
|
req->fixed_rsrc_refs = NULL; |
|
/* one is dropped after submission, the other at completion */ |
|
refcount_set(&req->refs, 2); |
|
req->task = current; |
|
req->result = 0; |
|
req->work.list.next = NULL; |
|
req->work.creds = NULL; |
|
req->work.flags = 0; |
|
|
|
/* enforce forwards compatibility on users */ |
|
if (unlikely(sqe_flags & ~SQE_VALID_FLAGS)) { |
|
req->flags = 0; |
|
return -EINVAL; |
|
} |
|
|
|
if (unlikely(req->opcode >= IORING_OP_LAST)) |
|
return -EINVAL; |
|
|
|
if (unlikely(!io_check_restriction(ctx, req, sqe_flags))) |
|
return -EACCES; |
|
|
|
if ((sqe_flags & IOSQE_BUFFER_SELECT) && |
|
!io_op_defs[req->opcode].buffer_select) |
|
return -EOPNOTSUPP; |
|
|
|
personality = READ_ONCE(sqe->personality); |
|
if (personality) { |
|
req->work.creds = xa_load(&ctx->personalities, personality); |
|
if (!req->work.creds) |
|
return -EINVAL; |
|
get_cred(req->work.creds); |
|
} |
|
state = &ctx->submit_state; |
|
|
|
/* |
|
* Plug now if we have more than 1 IO left after this, and the target |
|
* is potentially a read/write to block based storage. |
|
*/ |
|
if (!state->plug_started && state->ios_left > 1 && |
|
io_op_defs[req->opcode].plug) { |
|
blk_start_plug(&state->plug); |
|
state->plug_started = true; |
|
} |
|
|
|
if (io_op_defs[req->opcode].needs_file) { |
|
bool fixed = req->flags & REQ_F_FIXED_FILE; |
|
|
|
req->file = io_file_get(state, req, READ_ONCE(sqe->fd), fixed); |
|
if (unlikely(!req->file)) |
|
ret = -EBADF; |
|
} |
|
|
|
state->ios_left--; |
|
return ret; |
|
} |
|
|
|
static int io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, |
|
const struct io_uring_sqe *sqe) |
|
{ |
|
struct io_submit_link *link = &ctx->submit_state.link; |
|
int ret; |
|
|
|
ret = io_init_req(ctx, req, sqe); |
|
if (unlikely(ret)) { |
|
fail_req: |
|
if (link->head) { |
|
/* fail even hard links since we don't submit */ |
|
link->head->flags |= REQ_F_FAIL_LINK; |
|
io_put_req(link->head); |
|
io_req_complete(link->head, -ECANCELED); |
|
link->head = NULL; |
|
} |
|
io_put_req(req); |
|
io_req_complete(req, ret); |
|
return ret; |
|
} |
|
ret = io_req_prep(req, sqe); |
|
if (unlikely(ret)) |
|
goto fail_req; |
|
|
|
/* don't need @sqe from now on */ |
|
trace_io_uring_submit_sqe(ctx, req->opcode, req->user_data, |
|
true, ctx->flags & IORING_SETUP_SQPOLL); |
|
|
|
/* |
|
* If we already have a head request, queue this one for async |
|
* submittal once the head completes. If we don't have a head but |
|
* IOSQE_IO_LINK is set in the sqe, start a new head. This one will be |
|
* submitted sync once the chain is complete. If none of those |
|
* conditions are true (normal request), then just queue it. |
|
*/ |
|
if (link->head) { |
|
struct io_kiocb *head = link->head; |
|
|
|
/* |
|
* Taking sequential execution of a link, draining both sides |
|
* of the link also fullfils IOSQE_IO_DRAIN semantics for all |
|
* requests in the link. So, it drains the head and the |
|
* next after the link request. The last one is done via |
|
* drain_next flag to persist the effect across calls. |
|
*/ |
|
if (req->flags & REQ_F_IO_DRAIN) { |
|
head->flags |= REQ_F_IO_DRAIN; |
|
ctx->drain_next = 1; |
|
} |
|
ret = io_req_defer_prep(req); |
|
if (unlikely(ret)) |
|
goto fail_req; |
|
trace_io_uring_link(ctx, req, head); |
|
link->last->link = req; |
|
link->last = req; |
|
|
|
/* last request of a link, enqueue the link */ |
|
if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) { |
|
io_queue_sqe(head); |
|
link->head = NULL; |
|
} |
|
} else { |
|
if (unlikely(ctx->drain_next)) { |
|
req->flags |= REQ_F_IO_DRAIN; |
|
ctx->drain_next = 0; |
|
} |
|
if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) { |
|
link->head = req; |
|
link->last = req; |
|
} else { |
|
io_queue_sqe(req); |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Batched submission is done, ensure local IO is flushed out. |
|
*/ |
|
static void io_submit_state_end(struct io_submit_state *state, |
|
struct io_ring_ctx *ctx) |
|
{ |
|
if (state->link.head) |
|
io_queue_sqe(state->link.head); |
|
if (state->comp.nr) |
|
io_submit_flush_completions(&state->comp, ctx); |
|
if (state->plug_started) |
|
blk_finish_plug(&state->plug); |
|
io_state_file_put(state); |
|
} |
|
|
|
/* |
|
* Start submission side cache. |
|
*/ |
|
static void io_submit_state_start(struct io_submit_state *state, |
|
unsigned int max_ios) |
|
{ |
|
state->plug_started = false; |
|
state->ios_left = max_ios; |
|
/* set only head, no need to init link_last in advance */ |
|
state->link.head = NULL; |
|
} |
|
|
|
static void io_commit_sqring(struct io_ring_ctx *ctx) |
|
{ |
|
struct io_rings *rings = ctx->rings; |
|
|
|
/* |
|
* Ensure any loads from the SQEs are done at this point, |
|
* since once we write the new head, the application could |
|
* write new data to them. |
|
*/ |
|
smp_store_release(&rings->sq.head, ctx->cached_sq_head); |
|
} |
|
|
|
/* |
|
* Fetch an sqe, if one is available. Note that sqe_ptr will point to memory |
|
* that is mapped by userspace. This means that care needs to be taken to |
|
* ensure that reads are stable, as we cannot rely on userspace always |
|
* being a good citizen. If members of the sqe are validated and then later |
|
* used, it's important that those reads are done through READ_ONCE() to |
|
* prevent a re-load down the line. |
|
*/ |
|
static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx) |
|
{ |
|
u32 *sq_array = ctx->sq_array; |
|
unsigned head; |
|
|
|
/* |
|
* The cached sq head (or cq tail) serves two purposes: |
|
* |
|
* 1) allows us to batch the cost of updating the user visible |
|
* head updates. |
|
* 2) allows the kernel side to track the head on its own, even |
|
* though the application is the one updating it. |
|
*/ |
|
head = READ_ONCE(sq_array[ctx->cached_sq_head++ & ctx->sq_mask]); |
|
if (likely(head < ctx->sq_entries)) |
|
return &ctx->sq_sqes[head]; |
|
|
|
/* drop invalid entries */ |
|
ctx->cached_sq_dropped++; |
|
WRITE_ONCE(ctx->rings->sq_dropped, ctx->cached_sq_dropped); |
|
return NULL; |
|
} |
|
|
|
static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr) |
|
{ |
|
int submitted = 0; |
|
|
|
/* if we have a backlog and couldn't flush it all, return BUSY */ |
|
if (test_bit(0, &ctx->sq_check_overflow)) { |
|
if (!__io_cqring_overflow_flush(ctx, false, NULL, NULL)) |
|
return -EBUSY; |
|
} |
|
|
|
/* make sure SQ entry isn't read before tail */ |
|
nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx)); |
|
|
|
if (!percpu_ref_tryget_many(&ctx->refs, nr)) |
|
return -EAGAIN; |
|
|
|
percpu_counter_add(¤t->io_uring->inflight, nr); |
|
refcount_add(nr, ¤t->usage); |
|
io_submit_state_start(&ctx->submit_state, nr); |
|
|
|
while (submitted < nr) { |
|
const struct io_uring_sqe *sqe; |
|
struct io_kiocb *req; |
|
|
|
req = io_alloc_req(ctx); |
|
if (unlikely(!req)) { |
|
if (!submitted) |
|
submitted = -EAGAIN; |
|
break; |
|
} |
|
sqe = io_get_sqe(ctx); |
|
if (unlikely(!sqe)) { |
|
kmem_cache_free(req_cachep, req); |
|
break; |
|
} |
|
/* will complete beyond this point, count as submitted */ |
|
submitted++; |
|
if (io_submit_sqe(ctx, req, sqe)) |
|
break; |
|
} |
|
|
|
if (unlikely(submitted != nr)) { |
|
int ref_used = (submitted == -EAGAIN) ? 0 : submitted; |
|
struct io_uring_task *tctx = current->io_uring; |
|
int unused = nr - ref_used; |
|
|
|
percpu_ref_put_many(&ctx->refs, unused); |
|
percpu_counter_sub(&tctx->inflight, unused); |
|
put_task_struct_many(current, unused); |
|
} |
|
|
|
io_submit_state_end(&ctx->submit_state, ctx); |
|
/* Commit SQ ring head once we've consumed and submitted all SQEs */ |
|
io_commit_sqring(ctx); |
|
|
|
return submitted; |
|
} |
|
|
|
static inline void io_ring_set_wakeup_flag(struct io_ring_ctx *ctx) |
|
{ |
|
/* Tell userspace we may need a wakeup call */ |
|
spin_lock_irq(&ctx->completion_lock); |
|
ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP; |
|
spin_unlock_irq(&ctx->completion_lock); |
|
} |
|
|
|
static inline void io_ring_clear_wakeup_flag(struct io_ring_ctx *ctx) |
|
{ |
|
spin_lock_irq(&ctx->completion_lock); |
|
ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP; |
|
spin_unlock_irq(&ctx->completion_lock); |
|
} |
|
|
|
static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries) |
|
{ |
|
unsigned int to_submit; |
|
int ret = 0; |
|
|
|
to_submit = io_sqring_entries(ctx); |
|
/* if we're handling multiple rings, cap submit size for fairness */ |
|
if (cap_entries && to_submit > 8) |
|
to_submit = 8; |
|
|
|
if (!list_empty(&ctx->iopoll_list) || to_submit) { |
|
unsigned nr_events = 0; |
|
|
|
mutex_lock(&ctx->uring_lock); |
|
if (!list_empty(&ctx->iopoll_list)) |
|
io_do_iopoll(ctx, &nr_events, 0); |
|
|
|
/* |
|
* Don't submit if refs are dying, good for io_uring_register(), |
|
* but also it is relied upon by io_ring_exit_work() |
|
*/ |
|
if (to_submit && likely(!percpu_ref_is_dying(&ctx->refs)) && |
|
!(ctx->flags & IORING_SETUP_R_DISABLED)) |
|
ret = io_submit_sqes(ctx, to_submit); |
|
mutex_unlock(&ctx->uring_lock); |
|
} |
|
|
|
if (!io_sqring_full(ctx) && wq_has_sleeper(&ctx->sqo_sq_wait)) |
|
wake_up(&ctx->sqo_sq_wait); |
|
|
|
return ret; |
|
} |
|
|
|
static void io_sqd_update_thread_idle(struct io_sq_data *sqd) |
|
{ |
|
struct io_ring_ctx *ctx; |
|
unsigned sq_thread_idle = 0; |
|
|
|
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { |
|
if (sq_thread_idle < ctx->sq_thread_idle) |
|
sq_thread_idle = ctx->sq_thread_idle; |
|
} |
|
|
|
sqd->sq_thread_idle = sq_thread_idle; |
|
} |
|
|
|
static int io_sq_thread(void *data) |
|
{ |
|
struct io_sq_data *sqd = data; |
|
struct io_ring_ctx *ctx; |
|
unsigned long timeout = 0; |
|
char buf[TASK_COMM_LEN]; |
|
DEFINE_WAIT(wait); |
|
|
|
snprintf(buf, sizeof(buf), "iou-sqp-%d", sqd->task_pid); |
|
set_task_comm(current, buf); |
|
current->pf_io_worker = NULL; |
|
|
|
if (sqd->sq_cpu != -1) |
|
set_cpus_allowed_ptr(current, cpumask_of(sqd->sq_cpu)); |
|
else |
|
set_cpus_allowed_ptr(current, cpu_online_mask); |
|
current->flags |= PF_NO_SETAFFINITY; |
|
|
|
mutex_lock(&sqd->lock); |
|
/* a user may had exited before the thread started */ |
|
io_run_task_work_head(&sqd->park_task_work); |
|
|
|
while (!test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state)) { |
|
int ret; |
|
bool cap_entries, sqt_spin, needs_sched; |
|
|
|
if (test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state) || |
|
signal_pending(current)) { |
|
bool did_sig = false; |
|
|
|
mutex_unlock(&sqd->lock); |
|
if (signal_pending(current)) { |
|
struct ksignal ksig; |
|
|
|
did_sig = get_signal(&ksig); |
|
} |
|
cond_resched(); |
|
mutex_lock(&sqd->lock); |
|
io_run_task_work(); |
|
io_run_task_work_head(&sqd->park_task_work); |
|
if (did_sig) |
|
break; |
|
timeout = jiffies + sqd->sq_thread_idle; |
|
continue; |
|
} |
|
sqt_spin = false; |
|
cap_entries = !list_is_singular(&sqd->ctx_list); |
|
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { |
|
const struct cred *creds = NULL; |
|
|
|
if (ctx->sq_creds != current_cred()) |
|
creds = override_creds(ctx->sq_creds); |
|
ret = __io_sq_thread(ctx, cap_entries); |
|
if (creds) |
|
revert_creds(creds); |
|
if (!sqt_spin && (ret > 0 || !list_empty(&ctx->iopoll_list))) |
|
sqt_spin = true; |
|
} |
|
|
|
if (sqt_spin || !time_after(jiffies, timeout)) { |
|
io_run_task_work(); |
|
cond_resched(); |
|
if (sqt_spin) |
|
timeout = jiffies + sqd->sq_thread_idle; |
|
continue; |
|
} |
|
|
|
needs_sched = true; |
|
prepare_to_wait(&sqd->wait, &wait, TASK_INTERRUPTIBLE); |
|
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { |
|
if ((ctx->flags & IORING_SETUP_IOPOLL) && |
|
!list_empty_careful(&ctx->iopoll_list)) { |
|
needs_sched = false; |
|
break; |
|
} |
|
if (io_sqring_entries(ctx)) { |
|
needs_sched = false; |
|
break; |
|
} |
|
} |
|
|
|
if (needs_sched && !test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state)) { |
|
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) |
|
io_ring_set_wakeup_flag(ctx); |
|
|
|
mutex_unlock(&sqd->lock); |
|
schedule(); |
|
mutex_lock(&sqd->lock); |
|
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) |
|
io_ring_clear_wakeup_flag(ctx); |
|
} |
|
|
|
finish_wait(&sqd->wait, &wait); |
|
io_run_task_work_head(&sqd->park_task_work); |
|
timeout = jiffies + sqd->sq_thread_idle; |
|
} |
|
|
|
io_uring_cancel_sqpoll(sqd); |
|
sqd->thread = NULL; |
|
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) |
|
io_ring_set_wakeup_flag(ctx); |
|
io_run_task_work(); |
|
io_run_task_work_head(&sqd->park_task_work); |
|
mutex_unlock(&sqd->lock); |
|
|
|
complete(&sqd->exited); |
|
do_exit(0); |
|
} |
|
|
|
struct io_wait_queue { |
|
struct wait_queue_entry wq; |
|
struct io_ring_ctx *ctx; |
|
unsigned to_wait; |
|
unsigned nr_timeouts; |
|
}; |
|
|
|
static inline bool io_should_wake(struct io_wait_queue *iowq) |
|
{ |
|
struct io_ring_ctx *ctx = iowq->ctx; |
|
|
|
/* |
|
* Wake up if we have enough events, or if a timeout occurred since we |
|
* started waiting. For timeouts, we always want to return to userspace, |
|
* regardless of event count. |
|
*/ |
|
return io_cqring_events(ctx) >= iowq->to_wait || |
|
atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts; |
|
} |
|
|
|
static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode, |
|
int wake_flags, void *key) |
|
{ |
|
struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue, |
|
wq); |
|
|
|
/* |
|
* Cannot safely flush overflowed CQEs from here, ensure we wake up |
|
* the task, and the next invocation will do it. |
|
*/ |
|
if (io_should_wake(iowq) || test_bit(0, &iowq->ctx->cq_check_overflow)) |
|
return autoremove_wake_function(curr, mode, wake_flags, key); |
|
return -1; |
|
} |
|
|
|
static int io_run_task_work_sig(void) |
|
{ |
|
if (io_run_task_work()) |
|
return 1; |
|
if (!signal_pending(current)) |
|
return 0; |
|
if (test_thread_flag(TIF_NOTIFY_SIGNAL)) |
|
return -ERESTARTSYS; |
|
return -EINTR; |
|
} |
|
|
|
/* when returns >0, the caller should retry */ |
|
static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, |
|
struct io_wait_queue *iowq, |
|
signed long *timeout) |
|
{ |
|
int ret; |
|
|
|
/* make sure we run task_work before checking for signals */ |
|
ret = io_run_task_work_sig(); |
|
if (ret || io_should_wake(iowq)) |
|
return ret; |
|
/* let the caller flush overflows, retry */ |
|
if (test_bit(0, &ctx->cq_check_overflow)) |
|
return 1; |
|
|
|
*timeout = schedule_timeout(*timeout); |
|
return !*timeout ? -ETIME : 1; |
|
} |
|
|
|
/* |
|
* Wait until events become available, if we don't already have some. The |
|
* application must reap them itself, as they reside on the shared cq ring. |
|
*/ |
|
static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, |
|
const sigset_t __user *sig, size_t sigsz, |
|
struct __kernel_timespec __user *uts) |
|
{ |
|
struct io_wait_queue iowq = { |
|
.wq = { |
|
.private = current, |
|
.func = io_wake_function, |
|
.entry = LIST_HEAD_INIT(iowq.wq.entry), |
|
}, |
|
.ctx = ctx, |
|
.to_wait = min_events, |
|
}; |
|
struct io_rings *rings = ctx->rings; |
|
signed long timeout = MAX_SCHEDULE_TIMEOUT; |
|
int ret; |
|
|
|
do { |
|
io_cqring_overflow_flush(ctx, false, NULL, NULL); |
|
if (io_cqring_events(ctx) >= min_events) |
|
return 0; |
|
if (!io_run_task_work()) |
|
break; |
|
} while (1); |
|
|
|
if (sig) { |
|
#ifdef CONFIG_COMPAT |
|
if (in_compat_syscall()) |
|
ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig, |
|
sigsz); |
|
else |
|
#endif |
|
ret = set_user_sigmask(sig, sigsz); |
|
|
|
if (ret) |
|
return ret; |
|
} |
|
|
|
if (uts) { |
|
struct timespec64 ts; |
|
|
|
if (get_timespec64(&ts, uts)) |
|
return -EFAULT; |
|
timeout = timespec64_to_jiffies(&ts); |
|
} |
|
|
|
iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts); |
|
trace_io_uring_cqring_wait(ctx, min_events); |
|
do { |
|
/* if we can't even flush overflow, don't wait for more */ |
|
if (!io_cqring_overflow_flush(ctx, false, NULL, NULL)) { |
|
ret = -EBUSY; |
|
break; |
|
} |
|
prepare_to_wait_exclusive(&ctx->wait, &iowq.wq, |
|
TASK_INTERRUPTIBLE); |
|
ret = io_cqring_wait_schedule(ctx, &iowq, &timeout); |
|
finish_wait(&ctx->wait, &iowq.wq); |
|
cond_resched(); |
|
} while (ret > 0); |
|
|
|
restore_saved_sigmask_unless(ret == -EINTR); |
|
|
|
return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0; |
|
} |
|
|
|
static void __io_sqe_files_unregister(struct io_ring_ctx *ctx) |
|
{ |
|
#if defined(CONFIG_UNIX) |
|
if (ctx->ring_sock) { |
|
struct sock *sock = ctx->ring_sock->sk; |
|
struct sk_buff *skb; |
|
|
|
while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL) |
|
kfree_skb(skb); |
|
} |
|
#else |
|
int i; |
|
|
|
for (i = 0; i < ctx->nr_user_files; i++) { |
|
struct file *file; |
|
|
|
file = io_file_from_index(ctx, i); |
|
if (file) |
|
fput(file); |
|
} |
|
#endif |
|
} |
|
|
|
static void io_rsrc_data_ref_zero(struct percpu_ref *ref) |
|
{ |
|
struct fixed_rsrc_data *data; |
|
|
|
data = container_of(ref, struct fixed_rsrc_data, refs); |
|
complete(&data->done); |
|
} |
|
|
|
static inline void io_rsrc_ref_lock(struct io_ring_ctx *ctx) |
|
{ |
|
spin_lock_bh(&ctx->rsrc_ref_lock); |
|
} |
|
|
|
static inline void io_rsrc_ref_unlock(struct io_ring_ctx *ctx) |
|
{ |
|
spin_unlock_bh(&ctx->rsrc_ref_lock); |
|
} |
|
|
|
static void io_sqe_rsrc_set_node(struct io_ring_ctx *ctx, |
|
struct fixed_rsrc_data *rsrc_data, |
|
struct fixed_rsrc_ref_node *ref_node) |
|
{ |
|
io_rsrc_ref_lock(ctx); |
|
rsrc_data->node = ref_node; |
|
list_add_tail(&ref_node->node, &ctx->rsrc_ref_list); |
|
io_rsrc_ref_unlock(ctx); |
|
percpu_ref_get(&rsrc_data->refs); |
|
} |
|
|
|
static void io_sqe_rsrc_kill_node(struct io_ring_ctx *ctx, struct fixed_rsrc_data *data) |
|
{ |
|
struct fixed_rsrc_ref_node *ref_node = NULL; |
|
|
|
io_rsrc_ref_lock(ctx); |
|
ref_node = data->node; |
|
data->node = NULL; |
|
io_rsrc_ref_unlock(ctx); |
|
if (ref_node) |
|
percpu_ref_kill(&ref_node->refs); |
|
} |
|
|
|
static int io_rsrc_ref_quiesce(struct fixed_rsrc_data *data, |
|
struct io_ring_ctx *ctx, |
|
void (*rsrc_put)(struct io_ring_ctx *ctx, |
|
struct io_rsrc_put *prsrc)) |
|
{ |
|
struct fixed_rsrc_ref_node *backup_node; |
|
int ret; |
|
|
|
if (data->quiesce) |
|
return -ENXIO; |
|
|
|
data->quiesce = true; |
|
do { |
|
ret = -ENOMEM; |
|
backup_node = alloc_fixed_rsrc_ref_node(ctx); |
|
if (!backup_node) |
|
break; |
|
backup_node->rsrc_data = data; |
|
backup_node->rsrc_put = rsrc_put; |
|
|
|
io_sqe_rsrc_kill_node(ctx, data); |
|
percpu_ref_kill(&data->refs); |
|
flush_delayed_work(&ctx->rsrc_put_work); |
|
|
|
ret = wait_for_completion_interruptible(&data->done); |
|
if (!ret) |
|
break; |
|
|
|
percpu_ref_resurrect(&data->refs); |
|
io_sqe_rsrc_set_node(ctx, data, backup_node); |
|
backup_node = NULL; |
|
reinit_completion(&data->done); |
|
mutex_unlock(&ctx->uring_lock); |
|
ret = io_run_task_work_sig(); |
|
mutex_lock(&ctx->uring_lock); |
|
} while (ret >= 0); |
|
data->quiesce = false; |
|
|
|
if (backup_node) |
|
destroy_fixed_rsrc_ref_node(backup_node); |
|
return ret; |
|
} |
|
|
|
static struct fixed_rsrc_data *alloc_fixed_rsrc_data(struct io_ring_ctx *ctx) |
|
{ |
|
struct fixed_rsrc_data *data; |
|
|
|
data = kzalloc(sizeof(*data), GFP_KERNEL); |
|
if (!data) |
|
return NULL; |
|
|
|
if (percpu_ref_init(&data->refs, io_rsrc_data_ref_zero, |
|
PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) { |
|
kfree(data); |
|
return NULL; |
|
} |
|
data->ctx = ctx; |
|
init_completion(&data->done); |
|
return data; |
|
} |
|
|
|
static void free_fixed_rsrc_data(struct fixed_rsrc_data *data) |
|
{ |
|
percpu_ref_exit(&data->refs); |
|
kfree(data->table); |
|
kfree(data); |
|
} |
|
|
|
static int io_sqe_files_unregister(struct io_ring_ctx *ctx) |
|
{ |
|
struct fixed_rsrc_data *data = ctx->file_data; |
|
unsigned nr_tables, i; |
|
int ret; |
|
|
|
/* |
|
* percpu_ref_is_dying() is to stop parallel files unregister |
|
* Since we possibly drop uring lock later in this function to |
|
* run task work. |
|
*/ |
|
if (!data || percpu_ref_is_dying(&data->refs)) |
|
return -ENXIO; |
|
ret = io_rsrc_ref_quiesce(data, ctx, io_ring_file_put); |
|
if (ret) |
|
return ret; |
|
|
|
__io_sqe_files_unregister(ctx); |
|
nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE); |
|
for (i = 0; i < nr_tables; i++) |
|
kfree(data->table[i].files); |
|
free_fixed_rsrc_data(data); |
|
ctx->file_data = NULL; |
|
ctx->nr_user_files = 0; |
|
return 0; |
|
} |
|
|
|
static void io_sq_thread_unpark(struct io_sq_data *sqd) |
|
__releases(&sqd->lock) |
|
{ |
|
WARN_ON_ONCE(sqd->thread == current); |
|
|
|
/* |
|
* Do the dance but not conditional clear_bit() because it'd race with |
|
* other threads incrementing park_pending and setting the bit. |
|
*/ |
|
clear_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); |
|
if (atomic_dec_return(&sqd->park_pending)) |
|
set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); |
|
mutex_unlock(&sqd->lock); |
|
} |
|
|
|
static void io_sq_thread_park(struct io_sq_data *sqd) |
|
__acquires(&sqd->lock) |
|
{ |
|
WARN_ON_ONCE(sqd->thread == current); |
|
|
|
atomic_inc(&sqd->park_pending); |
|
set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); |
|
mutex_lock(&sqd->lock); |
|
if (sqd->thread) |
|
wake_up_process(sqd->thread); |
|
} |
|
|
|
static void io_sq_thread_stop(struct io_sq_data *sqd) |
|
{ |
|
WARN_ON_ONCE(sqd->thread == current); |
|
|
|
mutex_lock(&sqd->lock); |
|
set_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); |
|
if (sqd->thread) |
|
wake_up_process(sqd->thread); |
|
mutex_unlock(&sqd->lock); |
|
wait_for_completion(&sqd->exited); |
|
} |
|
|
|
static void io_put_sq_data(struct io_sq_data *sqd) |
|
{ |
|
if (refcount_dec_and_test(&sqd->refs)) { |
|
WARN_ON_ONCE(atomic_read(&sqd->park_pending)); |
|
|
|
io_sq_thread_stop(sqd); |
|
kfree(sqd); |
|
} |
|
} |
|
|
|
static void io_sq_thread_finish(struct io_ring_ctx *ctx) |
|
{ |
|
struct io_sq_data *sqd = ctx->sq_data; |
|
|
|
if (sqd) { |
|
io_sq_thread_park(sqd); |
|
list_del_init(&ctx->sqd_list); |
|
io_sqd_update_thread_idle(sqd); |
|
io_sq_thread_unpark(sqd); |
|
|
|
io_put_sq_data(sqd); |
|
ctx->sq_data = NULL; |
|
} |
|
} |
|
|
|
static struct io_sq_data *io_attach_sq_data(struct io_uring_params *p) |
|
{ |
|
struct io_ring_ctx *ctx_attach; |
|
struct io_sq_data *sqd; |
|
struct fd f; |
|
|
|
f = fdget(p->wq_fd); |
|
if (!f.file) |
|
return ERR_PTR(-ENXIO); |
|
if (f.file->f_op != &io_uring_fops) { |
|
fdput(f); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
ctx_attach = f.file->private_data; |
|
sqd = ctx_attach->sq_data; |
|
if (!sqd) { |
|
fdput(f); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
if (sqd->task_tgid != current->tgid) { |
|
fdput(f); |
|
return ERR_PTR(-EPERM); |
|
} |
|
|
|
refcount_inc(&sqd->refs); |
|
fdput(f); |
|
return sqd; |
|
} |
|
|
|
static struct io_sq_data *io_get_sq_data(struct io_uring_params *p, |
|
bool *attached) |
|
{ |
|
struct io_sq_data *sqd; |
|
|
|
*attached = false; |
|
if (p->flags & IORING_SETUP_ATTACH_WQ) { |
|
sqd = io_attach_sq_data(p); |
|
if (!IS_ERR(sqd)) { |
|
*attached = true; |
|
return sqd; |
|
} |
|
/* fall through for EPERM case, setup new sqd/task */ |
|
if (PTR_ERR(sqd) != -EPERM) |
|
return sqd; |
|
} |
|
|
|
sqd = kzalloc(sizeof(*sqd), GFP_KERNEL); |
|
if (!sqd) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
atomic_set(&sqd->park_pending, 0); |
|
refcount_set(&sqd->refs, 1); |
|
INIT_LIST_HEAD(&sqd->ctx_list); |
|
mutex_init(&sqd->lock); |
|
init_waitqueue_head(&sqd->wait); |
|
init_completion(&sqd->exited); |
|
return sqd; |
|
} |
|
|
|
#if defined(CONFIG_UNIX) |
|
/* |
|
* Ensure the UNIX gc is aware of our file set, so we are certain that |
|
* the io_uring can be safely unregistered on process exit, even if we have |
|
* loops in the file referencing. |
|
*/ |
|
static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset) |
|
{ |
|
struct sock *sk = ctx->ring_sock->sk; |
|
struct scm_fp_list *fpl; |
|
struct sk_buff *skb; |
|
int i, nr_files; |
|
|
|
fpl = kzalloc(sizeof(*fpl), GFP_KERNEL); |
|
if (!fpl) |
|
return -ENOMEM; |
|
|
|
skb = alloc_skb(0, GFP_KERNEL); |
|
if (!skb) { |
|
kfree(fpl); |
|
return -ENOMEM; |
|
} |
|
|
|
skb->sk = sk; |
|
|
|
nr_files = 0; |
|
fpl->user = get_uid(current_user()); |
|
for (i = 0; i < nr; i++) { |
|
struct file *file = io_file_from_index(ctx, i + offset); |
|
|
|
if (!file) |
|
continue; |
|
fpl->fp[nr_files] = get_file(file); |
|
unix_inflight(fpl->user, fpl->fp[nr_files]); |
|
nr_files++; |
|
} |
|
|
|
if (nr_files) { |
|
fpl->max = SCM_MAX_FD; |
|
fpl->count = nr_files; |
|
UNIXCB(skb).fp = fpl; |
|
skb->destructor = unix_destruct_scm; |
|
refcount_add(skb->truesize, &sk->sk_wmem_alloc); |
|
skb_queue_head(&sk->sk_receive_queue, skb); |
|
|
|
for (i = 0; i < nr_files; i++) |
|
fput(fpl->fp[i]); |
|
} else { |
|
kfree_skb(skb); |
|
kfree(fpl); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* If UNIX sockets are enabled, fd passing can cause a reference cycle which |
|
* causes regular reference counting to break down. We rely on the UNIX |
|
* garbage collection to take care of this problem for us. |
|
*/ |
|
static int io_sqe_files_scm(struct io_ring_ctx *ctx) |
|
{ |
|
unsigned left, total; |
|
int ret = 0; |
|
|
|
total = 0; |
|
left = ctx->nr_user_files; |
|
while (left) { |
|
unsigned this_files = min_t(unsigned, left, SCM_MAX_FD); |
|
|
|
ret = __io_sqe_files_scm(ctx, this_files, total); |
|
if (ret) |
|
break; |
|
left -= this_files; |
|
total += this_files; |
|
} |
|
|
|
if (!ret) |
|
return 0; |
|
|
|
while (total < ctx->nr_user_files) { |
|
struct file *file = io_file_from_index(ctx, total); |
|
|
|
if (file) |
|
fput(file); |
|
total++; |
|
} |
|
|
|
return ret; |
|
} |
|
#else |
|
static int io_sqe_files_scm(struct io_ring_ctx *ctx) |
|
{ |
|
return 0; |
|
} |
|
#endif |
|
|
|
static int io_sqe_alloc_file_tables(struct fixed_rsrc_data *file_data, |
|
unsigned nr_tables, unsigned nr_files) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < nr_tables; i++) { |
|
struct fixed_rsrc_table *table = &file_data->table[i]; |
|
unsigned this_files; |
|
|
|
this_files = min(nr_files, IORING_MAX_FILES_TABLE); |
|
table->files = kcalloc(this_files, sizeof(struct file *), |
|
GFP_KERNEL); |
|
if (!table->files) |
|
break; |
|
nr_files -= this_files; |
|
} |
|
|
|
if (i == nr_tables) |
|
return 0; |
|
|
|
for (i = 0; i < nr_tables; i++) { |
|
struct fixed_rsrc_table *table = &file_data->table[i]; |
|
kfree(table->files); |
|
} |
|
return 1; |
|
} |
|
|
|
static void io_ring_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc) |
|
{ |
|
struct file *file = prsrc->file; |
|
#if defined(CONFIG_UNIX) |
|
struct sock *sock = ctx->ring_sock->sk; |
|
struct sk_buff_head list, *head = &sock->sk_receive_queue; |
|
struct sk_buff *skb; |
|
int i; |
|
|
|
__skb_queue_head_init(&list); |
|
|
|
/* |
|
* Find the skb that holds this file in its SCM_RIGHTS. When found, |
|
* remove this entry and rearrange the file array. |
|
*/ |
|
skb = skb_dequeue(head); |
|
while (skb) { |
|
struct scm_fp_list *fp; |
|
|
|
fp = UNIXCB(skb).fp; |
|
for (i = 0; i < fp->count; i++) { |
|
int left; |
|
|
|
if (fp->fp[i] != file) |
|
continue; |
|
|
|
unix_notinflight(fp->user, fp->fp[i]); |
|
left = fp->count - 1 - i; |
|
if (left) { |
|
memmove(&fp->fp[i], &fp->fp[i + 1], |
|
left * sizeof(struct file *)); |
|
} |
|
fp->count--; |
|
if (!fp->count) { |
|
kfree_skb(skb); |
|
skb = NULL; |
|
} else { |
|
__skb_queue_tail(&list, skb); |
|
} |
|
fput(file); |
|
file = NULL; |
|
break; |
|
} |
|
|
|
if (!file) |
|
break; |
|
|
|
__skb_queue_tail(&list, skb); |
|
|
|
skb = skb_dequeue(head); |
|
} |
|
|
|
if (skb_peek(&list)) { |
|
spin_lock_irq(&head->lock); |
|
while ((skb = __skb_dequeue(&list)) != NULL) |
|
__skb_queue_tail(head, skb); |
|
spin_unlock_irq(&head->lock); |
|
} |
|
#else |
|
fput(file); |
|
#endif |
|
} |
|
|
|
static void __io_rsrc_put_work(struct fixed_rsrc_ref_node *ref_node) |
|
{ |
|
struct fixed_rsrc_data *rsrc_data = ref_node->rsrc_data; |
|
struct io_ring_ctx *ctx = rsrc_data->ctx; |
|
struct io_rsrc_put *prsrc, *tmp; |
|
|
|
list_for_each_entry_safe(prsrc, tmp, &ref_node->rsrc_list, list) { |
|
list_del(&prsrc->list); |
|
ref_node->rsrc_put(ctx, prsrc); |
|
kfree(prsrc); |
|
} |
|
|
|
percpu_ref_exit(&ref_node->refs); |
|
kfree(ref_node); |
|
percpu_ref_put(&rsrc_data->refs); |
|
} |
|
|
|
static void io_rsrc_put_work(struct work_struct *work) |
|
{ |
|
struct io_ring_ctx *ctx; |
|
struct llist_node *node; |
|
|
|
ctx = container_of(work, struct io_ring_ctx, rsrc_put_work.work); |
|
node = llist_del_all(&ctx->rsrc_put_llist); |
|
|
|
while (node) { |
|
struct fixed_rsrc_ref_node *ref_node; |
|
struct llist_node *next = node->next; |
|
|
|
ref_node = llist_entry(node, struct fixed_rsrc_ref_node, llist); |
|
__io_rsrc_put_work(ref_node); |
|
node = next; |
|
} |
|
} |
|
|
|
static struct file **io_fixed_file_slot(struct fixed_rsrc_data *file_data, |
|
unsigned i) |
|
{ |
|
struct fixed_rsrc_table *table; |
|
|
|
table = &file_data->table[i >> IORING_FILE_TABLE_SHIFT]; |
|
return &table->files[i & IORING_FILE_TABLE_MASK]; |
|
} |
|
|
|
static void io_rsrc_node_ref_zero(struct percpu_ref *ref) |
|
{ |
|
struct fixed_rsrc_ref_node *ref_node; |
|
struct fixed_rsrc_data *data; |
|
struct io_ring_ctx *ctx; |
|
bool first_add = false; |
|
int delay = HZ; |
|
|
|
ref_node = container_of(ref, struct fixed_rsrc_ref_node, refs); |
|
data = ref_node->rsrc_data; |
|
ctx = data->ctx; |
|
|
|
io_rsrc_ref_lock(ctx); |
|
ref_node->done = true; |
|
|
|
while (!list_empty(&ctx->rsrc_ref_list)) { |
|
ref_node = list_first_entry(&ctx->rsrc_ref_list, |
|
struct fixed_rsrc_ref_node, node); |
|
/* recycle ref nodes in order */ |
|
if (!ref_node->done) |
|
break; |
|
list_del(&ref_node->node); |
|
first_add |= llist_add(&ref_node->llist, &ctx->rsrc_put_llist); |
|
} |
|
io_rsrc_ref_unlock(ctx); |
|
|
|
if (percpu_ref_is_dying(&data->refs)) |
|
delay = 0; |
|
|
|
if (!delay) |
|
mod_delayed_work(system_wq, &ctx->rsrc_put_work, 0); |
|
else if (first_add) |
|
queue_delayed_work(system_wq, &ctx->rsrc_put_work, delay); |
|
} |
|
|
|
static struct fixed_rsrc_ref_node *alloc_fixed_rsrc_ref_node( |
|
struct io_ring_ctx *ctx) |
|
{ |
|
struct fixed_rsrc_ref_node *ref_node; |
|
|
|
ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL); |
|
if (!ref_node) |
|
return NULL; |
|
|
|
if (percpu_ref_init(&ref_node->refs, io_rsrc_node_ref_zero, |
|
0, GFP_KERNEL)) { |
|
kfree(ref_node); |
|
return NULL; |
|
} |
|
INIT_LIST_HEAD(&ref_node->node); |
|
INIT_LIST_HEAD(&ref_node->rsrc_list); |
|
ref_node->done = false; |
|
return ref_node; |
|
} |
|
|
|
static void init_fixed_file_ref_node(struct io_ring_ctx *ctx, |
|
struct fixed_rsrc_ref_node *ref_node) |
|
{ |
|
ref_node->rsrc_data = ctx->file_data; |
|
ref_node->rsrc_put = io_ring_file_put; |
|
} |
|
|
|
static void destroy_fixed_rsrc_ref_node(struct fixed_rsrc_ref_node *ref_node) |
|
{ |
|
percpu_ref_exit(&ref_node->refs); |
|
kfree(ref_node); |
|
} |
|
|
|
|
|
static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, |
|
unsigned nr_args) |
|
{ |
|
__s32 __user *fds = (__s32 __user *) arg; |
|
unsigned nr_tables, i; |
|
struct file *file; |
|
int fd, ret = -ENOMEM; |
|
struct fixed_rsrc_ref_node *ref_node; |
|
struct fixed_rsrc_data *file_data; |
|
|
|
if (ctx->file_data) |
|
return -EBUSY; |
|
if (!nr_args) |
|
return -EINVAL; |
|
if (nr_args > IORING_MAX_FIXED_FILES) |
|
return -EMFILE; |
|
|
|
file_data = alloc_fixed_rsrc_data(ctx); |
|
if (!file_data) |
|
return -ENOMEM; |
|
ctx->file_data = file_data; |
|
|
|
nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE); |
|
file_data->table = kcalloc(nr_tables, sizeof(*file_data->table), |
|
GFP_KERNEL); |
|
if (!file_data->table) |
|
goto out_free; |
|
|
|
if (io_sqe_alloc_file_tables(file_data, nr_tables, nr_args)) |
|
goto out_free; |
|
|
|
for (i = 0; i < nr_args; i++, ctx->nr_user_files++) { |
|
if (copy_from_user(&fd, &fds[i], sizeof(fd))) { |
|
ret = -EFAULT; |
|
goto out_fput; |
|
} |
|
/* allow sparse sets */ |
|
if (fd == -1) |
|
continue; |
|
|
|
file = fget(fd); |
|
ret = -EBADF; |
|
if (!file) |
|
goto out_fput; |
|
|
|
/* |
|
* Don't allow io_uring instances to be registered. If UNIX |
|
* isn't enabled, then this causes a reference cycle and this |
|
* instance can never get freed. If UNIX is enabled we'll |
|
* handle it just fine, but there's still no point in allowing |
|
* a ring fd as it doesn't support regular read/write anyway. |
|
*/ |
|
if (file->f_op == &io_uring_fops) { |
|
fput(file); |
|
goto out_fput; |
|
} |
|
*io_fixed_file_slot(file_data, i) = file; |
|
} |
|
|
|
ret = io_sqe_files_scm(ctx); |
|
if (ret) { |
|
io_sqe_files_unregister(ctx); |
|
return ret; |
|
} |
|
|
|
ref_node = alloc_fixed_rsrc_ref_node(ctx); |
|
if (!ref_node) { |
|
io_sqe_files_unregister(ctx); |
|
return -ENOMEM; |
|
} |
|
init_fixed_file_ref_node(ctx, ref_node); |
|
|
|
io_sqe_rsrc_set_node(ctx, file_data, ref_node); |
|
return ret; |
|
out_fput: |
|
for (i = 0; i < ctx->nr_user_files; i++) { |
|
file = io_file_from_index(ctx, i); |
|
if (file) |
|
fput(file); |
|
} |
|
for (i = 0; i < nr_tables; i++) |
|
kfree(file_data->table[i].files); |
|
ctx->nr_user_files = 0; |
|
out_free: |
|
free_fixed_rsrc_data(ctx->file_data); |
|
ctx->file_data = NULL; |
|
return ret; |
|
} |
|
|
|
static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file, |
|
int index) |
|
{ |
|
#if defined(CONFIG_UNIX) |
|
struct sock *sock = ctx->ring_sock->sk; |
|
struct sk_buff_head *head = &sock->sk_receive_queue; |
|
struct sk_buff *skb; |
|
|
|
/* |
|
* See if we can merge this file into an existing skb SCM_RIGHTS |
|
* file set. If there's no room, fall back to allocating a new skb |
|
* and filling it in. |
|
*/ |
|
spin_lock_irq(&head->lock); |
|
skb = skb_peek(head); |
|
if (skb) { |
|
struct scm_fp_list *fpl = UNIXCB(skb).fp; |
|
|
|
if (fpl->count < SCM_MAX_FD) { |
|
__skb_unlink(skb, head); |
|
spin_unlock_irq(&head->lock); |
|
fpl->fp[fpl->count] = get_file(file); |
|
unix_inflight(fpl->user, fpl->fp[fpl->count]); |
|
fpl->count++; |
|
spin_lock_irq(&head->lock); |
|
__skb_queue_head(head, skb); |
|
} else { |
|
skb = NULL; |
|
} |
|
} |
|
spin_unlock_irq(&head->lock); |
|
|
|
if (skb) { |
|
fput(file); |
|
return 0; |
|
} |
|
|
|
return __io_sqe_files_scm(ctx, 1, index); |
|
#else |
|
return 0; |
|
#endif |
|
} |
|
|
|
static int io_queue_rsrc_removal(struct fixed_rsrc_data *data, void *rsrc) |
|
{ |
|
struct io_rsrc_put *prsrc; |
|
struct fixed_rsrc_ref_node *ref_node = data->node; |
|
|
|
prsrc = kzalloc(sizeof(*prsrc), GFP_KERNEL); |
|
if (!prsrc) |
|
return -ENOMEM; |
|
|
|
prsrc->rsrc = rsrc; |
|
list_add(&prsrc->list, &ref_node->rsrc_list); |
|
|
|
return 0; |
|
} |
|
|
|
static inline int io_queue_file_removal(struct fixed_rsrc_data *data, |
|
struct file *file) |
|
{ |
|
return io_queue_rsrc_removal(data, (void *)file); |
|
} |
|
|
|
static int __io_sqe_files_update(struct io_ring_ctx *ctx, |
|
struct io_uring_rsrc_update *up, |
|
unsigned nr_args) |
|
{ |
|
struct fixed_rsrc_data *data = ctx->file_data; |
|
struct fixed_rsrc_ref_node *ref_node; |
|
struct file *file, **file_slot; |
|
__s32 __user *fds; |
|
int fd, i, err; |
|
__u32 done; |
|
bool needs_switch = false; |
|
|
|
if (check_add_overflow(up->offset, nr_args, &done)) |
|
return -EOVERFLOW; |
|
if (done > ctx->nr_user_files) |
|
return -EINVAL; |
|
|
|
ref_node = alloc_fixed_rsrc_ref_node(ctx); |
|
if (!ref_node) |
|
return -ENOMEM; |
|
init_fixed_file_ref_node(ctx, ref_node); |
|
|
|
fds = u64_to_user_ptr(up->data); |
|
for (done = 0; done < nr_args; done++) { |
|
err = 0; |
|
if (copy_from_user(&fd, &fds[done], sizeof(fd))) { |
|
err = -EFAULT; |
|
break; |
|
} |
|
if (fd == IORING_REGISTER_FILES_SKIP) |
|
continue; |
|
|
|
i = array_index_nospec(up->offset + done, ctx->nr_user_files); |
|
file_slot = io_fixed_file_slot(ctx->file_data, i); |
|
|
|
if (*file_slot) { |
|
err = io_queue_file_removal(data, *file_slot); |
|
if (err) |
|
break; |
|
*file_slot = NULL; |
|
needs_switch = true; |
|
} |
|
if (fd != -1) { |
|
file = fget(fd); |
|
if (!file) { |
|
err = -EBADF; |
|
break; |
|
} |
|
/* |
|
* Don't allow io_uring instances to be registered. If |
|
* UNIX isn't enabled, then this causes a reference |
|
* cycle and this instance can never get freed. If UNIX |
|
* is enabled we'll handle it just fine, but there's |
|
* still no point in allowing a ring fd as it doesn't |
|
* support regular read/write anyway. |
|
*/ |
|
if (file->f_op == &io_uring_fops) { |
|
fput(file); |
|
err = -EBADF; |
|
break; |
|
} |
|
*file_slot = file; |
|
err = io_sqe_file_register(ctx, file, i); |
|
if (err) { |
|
*file_slot = NULL; |
|
fput(file); |
|
break; |
|
} |
|
} |
|
} |
|
|
|
if (needs_switch) { |
|
percpu_ref_kill(&data->node->refs); |
|
io_sqe_rsrc_set_node(ctx, data, ref_node); |
|
} else |
|
destroy_fixed_rsrc_ref_node(ref_node); |
|
|
|
return done ? done : err; |
|
} |
|
|
|
static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg, |
|
unsigned nr_args) |
|
{ |
|
struct io_uring_rsrc_update up; |
|
|
|
if (!ctx->file_data) |
|
return -ENXIO; |
|
if (!nr_args) |
|
return -EINVAL; |
|
if (copy_from_user(&up, arg, sizeof(up))) |
|
return -EFAULT; |
|
if (up.resv) |
|
return -EINVAL; |
|
|
|
return __io_sqe_files_update(ctx, &up, nr_args); |
|
} |
|
|
|
static struct io_wq_work *io_free_work(struct io_wq_work *work) |
|
{ |
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work); |
|
|
|
req = io_put_req_find_next(req); |
|
return req ? &req->work : NULL; |
|
} |
|
|
|
static struct io_wq *io_init_wq_offload(struct io_ring_ctx *ctx) |
|
{ |
|
struct io_wq_hash *hash; |
|
struct io_wq_data data; |
|
unsigned int concurrency; |
|
|
|
hash = ctx->hash_map; |
|
if (!hash) { |
|
hash = kzalloc(sizeof(*hash), GFP_KERNEL); |
|
if (!hash) |
|
return ERR_PTR(-ENOMEM); |
|
refcount_set(&hash->refs, 1); |
|
init_waitqueue_head(&hash->wait); |
|
ctx->hash_map = hash; |
|
} |
|
|
|
data.hash = hash; |
|
data.free_work = io_free_work; |
|
data.do_work = io_wq_submit_work; |
|
|
|
/* Do QD, or 4 * CPUS, whatever is smallest */ |
|
concurrency = min(ctx->sq_entries, 4 * num_online_cpus()); |
|
|
|
return io_wq_create(concurrency, &data); |
|
} |
|
|
|
static int io_uring_alloc_task_context(struct task_struct *task, |
|
struct io_ring_ctx *ctx) |
|
{ |
|
struct io_uring_task *tctx; |
|
int ret; |
|
|
|
tctx = kmalloc(sizeof(*tctx), GFP_KERNEL); |
|
if (unlikely(!tctx)) |
|
return -ENOMEM; |
|
|
|
ret = percpu_counter_init(&tctx->inflight, 0, GFP_KERNEL); |
|
if (unlikely(ret)) { |
|
kfree(tctx); |
|
return ret; |
|
} |
|
|
|
tctx->io_wq = io_init_wq_offload(ctx); |
|
if (IS_ERR(tctx->io_wq)) { |
|
ret = PTR_ERR(tctx->io_wq); |
|
percpu_counter_destroy(&tctx->inflight); |
|
kfree(tctx); |
|
return ret; |
|
} |
|
|
|
xa_init(&tctx->xa); |
|
init_waitqueue_head(&tctx->wait); |
|
tctx->last = NULL; |
|
atomic_set(&tctx->in_idle, 0); |
|
task->io_uring = tctx; |
|
spin_lock_init(&tctx->task_lock); |
|
INIT_WQ_LIST(&tctx->task_list); |
|
tctx->task_state = 0; |
|
init_task_work(&tctx->task_work, tctx_task_work); |
|
return 0; |
|
} |
|
|
|
void __io_uring_free(struct task_struct *tsk) |
|
{ |
|
struct io_uring_task *tctx = tsk->io_uring; |
|
|
|
WARN_ON_ONCE(!xa_empty(&tctx->xa)); |
|
WARN_ON_ONCE(tctx->io_wq); |
|
|
|
percpu_counter_destroy(&tctx->inflight); |
|
kfree(tctx); |
|
tsk->io_uring = NULL; |
|
} |
|
|
|
static int io_sq_offload_create(struct io_ring_ctx *ctx, |
|
struct io_uring_params *p) |
|
{ |
|
int ret; |
|
|
|
/* Retain compatibility with failing for an invalid attach attempt */ |
|
if ((ctx->flags & (IORING_SETUP_ATTACH_WQ | IORING_SETUP_SQPOLL)) == |
|
IORING_SETUP_ATTACH_WQ) { |
|
struct fd f; |
|
|
|
f = fdget(p->wq_fd); |
|
if (!f.file) |
|
return -ENXIO; |
|
if (f.file->f_op != &io_uring_fops) { |
|
fdput(f); |
|
return -EINVAL; |
|
} |
|
fdput(f); |
|
} |
|
if (ctx->flags & IORING_SETUP_SQPOLL) { |
|
struct task_struct *tsk; |
|
struct io_sq_data *sqd; |
|
bool attached; |
|
|
|
ret = -EPERM; |
|
if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_NICE)) |
|
goto err; |
|
|
|
sqd = io_get_sq_data(p, &attached); |
|
if (IS_ERR(sqd)) { |
|
ret = PTR_ERR(sqd); |
|
goto err; |
|
} |
|
|
|
ctx->sq_creds = get_current_cred(); |
|
ctx->sq_data = sqd; |
|
ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle); |
|
if (!ctx->sq_thread_idle) |
|
ctx->sq_thread_idle = HZ; |
|
|
|
ret = 0; |
|
io_sq_thread_park(sqd); |
|
list_add(&ctx->sqd_list, &sqd->ctx_list); |
|
io_sqd_update_thread_idle(sqd); |
|
/* don't attach to a dying SQPOLL thread, would be racy */ |
|
if (attached && !sqd->thread) |
|
ret = -ENXIO; |
|
io_sq_thread_unpark(sqd); |
|
|
|
if (ret < 0) |
|
goto err; |
|
if (attached) |
|
return 0; |
|
|
|
if (p->flags & IORING_SETUP_SQ_AFF) { |
|
int cpu = p->sq_thread_cpu; |
|
|
|
ret = -EINVAL; |
|
if (cpu >= nr_cpu_ids) |
|
goto err_sqpoll; |
|
if (!cpu_online(cpu)) |
|
goto err_sqpoll; |
|
|
|
sqd->sq_cpu = cpu; |
|
} else { |
|
sqd->sq_cpu = -1; |
|
} |
|
|
|
sqd->task_pid = current->pid; |
|
sqd->task_tgid = current->tgid; |
|
tsk = create_io_thread(io_sq_thread, sqd, NUMA_NO_NODE); |
|
if (IS_ERR(tsk)) { |
|
ret = PTR_ERR(tsk); |
|
goto err_sqpoll; |
|
} |
|
|
|
sqd->thread = tsk; |
|
ret = io_uring_alloc_task_context(tsk, ctx); |
|
wake_up_new_task(tsk); |
|
if (ret) |
|
goto err; |
|
} else if (p->flags & IORING_SETUP_SQ_AFF) { |
|
/* Can't have SQ_AFF without SQPOLL */ |
|
ret = -EINVAL; |
|
goto err; |
|
} |
|
|
|
return 0; |
|
err: |
|
io_sq_thread_finish(ctx); |
|
return ret; |
|
err_sqpoll: |
|
complete(&ctx->sq_data->exited); |
|
goto err; |
|
} |
|
|
|
static inline void __io_unaccount_mem(struct user_struct *user, |
|
unsigned long nr_pages) |
|
{ |
|
atomic_long_sub(nr_pages, &user->locked_vm); |
|
} |
|
|
|
static inline int __io_account_mem(struct user_struct *user, |
|
unsigned long nr_pages) |
|
{ |
|
unsigned long page_limit, cur_pages, new_pages; |
|
|
|
/* Don't allow more pages than we can safely lock */ |
|
page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; |
|
|
|
do { |
|
cur_pages = atomic_long_read(&user->locked_vm); |
|
new_pages = cur_pages + nr_pages; |
|
if (new_pages > page_limit) |
|
return -ENOMEM; |
|
} while (atomic_long_cmpxchg(&user->locked_vm, cur_pages, |
|
new_pages) != cur_pages); |
|
|
|
return 0; |
|
} |
|
|
|
static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages) |
|
{ |
|
if (ctx->user) |
|
__io_unaccount_mem(ctx->user, nr_pages); |
|
|
|
if (ctx->mm_account) |
|
atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm); |
|
} |
|
|
|
static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages) |
|
{ |
|
int ret; |
|
|
|
if (ctx->user) { |
|
ret = __io_account_mem(ctx->user, nr_pages); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
if (ctx->mm_account) |
|
atomic64_add(nr_pages, &ctx->mm_account->pinned_vm); |
|
|
|
return 0; |
|
} |
|
|
|
static void io_mem_free(void *ptr) |
|
{ |
|
struct page *page; |
|
|
|
if (!ptr) |
|
return; |
|
|
|
page = virt_to_head_page(ptr); |
|
if (put_page_testzero(page)) |
|
free_compound_page(page); |
|
} |
|
|
|
static void *io_mem_alloc(size_t size) |
|
{ |
|
gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP | |
|
__GFP_NORETRY | __GFP_ACCOUNT; |
|
|
|
return (void *) __get_free_pages(gfp_flags, get_order(size)); |
|
} |
|
|
|
static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries, |
|
size_t *sq_offset) |
|
{ |
|
struct io_rings *rings; |
|
size_t off, sq_array_size; |
|
|
|
off = struct_size(rings, cqes, cq_entries); |
|
if (off == SIZE_MAX) |
|
return SIZE_MAX; |
|
|
|
#ifdef CONFIG_SMP |
|
off = ALIGN(off, SMP_CACHE_BYTES); |
|
if (off == 0) |
|
return SIZE_MAX; |
|
#endif |
|
|
|
if (sq_offset) |
|
*sq_offset = off; |
|
|
|
sq_array_size = array_size(sizeof(u32), sq_entries); |
|
if (sq_array_size == SIZE_MAX) |
|
return SIZE_MAX; |
|
|
|
if (check_add_overflow(off, sq_array_size, &off)) |
|
return SIZE_MAX; |
|
|
|
return off; |
|
} |
|
|
|
static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx) |
|
{ |
|
int i, j; |
|
|
|
if (!ctx->user_bufs) |
|
return -ENXIO; |
|
|
|
for (i = 0; i < ctx->nr_user_bufs; i++) { |
|
struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; |
|
|
|
for (j = 0; j < imu->nr_bvecs; j++) |
|
unpin_user_page(imu->bvec[j].bv_page); |
|
|
|
if (imu->acct_pages) |
|
io_unaccount_mem(ctx, imu->acct_pages); |
|
kvfree(imu->bvec); |
|
imu->nr_bvecs = 0; |
|
} |
|
|
|
kfree(ctx->user_bufs); |
|
ctx->user_bufs = NULL; |
|
ctx->nr_user_bufs = 0; |
|
return 0; |
|
} |
|
|
|
static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst, |
|
void __user *arg, unsigned index) |
|
{ |
|
struct iovec __user *src; |
|
|
|
#ifdef CONFIG_COMPAT |
|
if (ctx->compat) { |
|
struct compat_iovec __user *ciovs; |
|
struct compat_iovec ciov; |
|
|
|
ciovs = (struct compat_iovec __user *) arg; |
|
if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov))) |
|
return -EFAULT; |
|
|
|
dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base); |
|
dst->iov_len = ciov.iov_len; |
|
return 0; |
|
} |
|
#endif |
|
src = (struct iovec __user *) arg; |
|
if (copy_from_user(dst, &src[index], sizeof(*dst))) |
|
return -EFAULT; |
|
return 0; |
|
} |
|
|
|
/* |
|
* Not super efficient, but this is just a registration time. And we do cache |
|
* the last compound head, so generally we'll only do a full search if we don't |
|
* match that one. |
|
* |
|
* We check if the given compound head page has already been accounted, to |
|
* avoid double accounting it. This allows us to account the full size of the |
|
* page, not just the constituent pages of a huge page. |
|
*/ |
|
static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages, |
|
int nr_pages, struct page *hpage) |
|
{ |
|
int i, j; |
|
|
|
/* check current page array */ |
|
for (i = 0; i < nr_pages; i++) { |
|
if (!PageCompound(pages[i])) |
|
continue; |
|
if (compound_head(pages[i]) == hpage) |
|
return true; |
|
} |
|
|
|
/* check previously registered pages */ |
|
for (i = 0; i < ctx->nr_user_bufs; i++) { |
|
struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; |
|
|
|
for (j = 0; j < imu->nr_bvecs; j++) { |
|
if (!PageCompound(imu->bvec[j].bv_page)) |
|
continue; |
|
if (compound_head(imu->bvec[j].bv_page) == hpage) |
|
return true; |
|
} |
|
} |
|
|
|
return false; |
|
} |
|
|
|
static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages, |
|
int nr_pages, struct io_mapped_ubuf *imu, |
|
struct page **last_hpage) |
|
{ |
|
int i, ret; |
|
|
|
for (i = 0; i < nr_pages; i++) { |
|
if (!PageCompound(pages[i])) { |
|
imu->acct_pages++; |
|
} else { |
|
struct page *hpage; |
|
|
|
hpage = compound_head(pages[i]); |
|
if (hpage == *last_hpage) |
|
continue; |
|
*last_hpage = hpage; |
|
if (headpage_already_acct(ctx, pages, i, hpage)) |
|
continue; |
|
imu->acct_pages += page_size(hpage) >> PAGE_SHIFT; |
|
} |
|
} |
|
|
|
if (!imu->acct_pages) |
|
return 0; |
|
|
|
ret = io_account_mem(ctx, imu->acct_pages); |
|
if (ret) |
|
imu->acct_pages = 0; |
|
return ret; |
|
} |
|
|
|
static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov, |
|
struct io_mapped_ubuf *imu, |
|
struct page **last_hpage) |
|
{ |
|
struct vm_area_struct **vmas = NULL; |
|
struct page **pages = NULL; |
|
unsigned long off, start, end, ubuf; |
|
size_t size; |
|
int ret, pret, nr_pages, i; |
|
|
|
ubuf = (unsigned long) iov->iov_base; |
|
end = (ubuf + iov->iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
|
start = ubuf >> PAGE_SHIFT; |
|
nr_pages = end - start; |
|
|
|
ret = -ENOMEM; |
|
|
|
pages = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL); |
|
if (!pages) |
|
goto done; |
|
|
|
vmas = kvmalloc_array(nr_pages, sizeof(struct vm_area_struct *), |
|
GFP_KERNEL); |
|
if (!vmas) |
|
goto done; |
|
|
|
imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec), |
|
GFP_KERNEL); |
|
if (!imu->bvec) |
|
goto done; |
|
|
|
ret = 0; |
|
mmap_read_lock(current->mm); |
|
pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM, |
|
pages, vmas); |
|
if (pret == nr_pages) { |
|
/* don't support file backed memory */ |
|
for (i = 0; i < nr_pages; i++) { |
|
struct vm_area_struct *vma = vmas[i]; |
|
|
|
if (vma->vm_file && |
|
!is_file_hugepages(vma->vm_file)) { |
|
ret = -EOPNOTSUPP; |
|
break; |
|
} |
|
} |
|
} else { |
|
ret = pret < 0 ? pret : -EFAULT; |
|
} |
|
mmap_read_unlock(current->mm); |
|
if (ret) { |
|
/* |
|
* if we did partial map, or found file backed vmas, |
|
* release any pages we did get |
|
*/ |
|
if (pret > 0) |
|
unpin_user_pages(pages, pret); |
|
kvfree(imu->bvec); |
|
goto done; |
|
} |
|
|
|
ret = io_buffer_account_pin(ctx, pages, pret, imu, last_hpage); |
|
if (ret) { |
|
unpin_user_pages(pages, pret); |
|
kvfree(imu->bvec); |
|
goto done; |
|
} |
|
|
|
off = ubuf & ~PAGE_MASK; |
|
size = iov->iov_len; |
|
for (i = 0; i < nr_pages; i++) { |
|
size_t vec_len; |
|
|
|
vec_len = min_t(size_t, size, PAGE_SIZE - off); |
|
imu->bvec[i].bv_page = pages[i]; |
|
imu->bvec[i].bv_len = vec_len; |
|
imu->bvec[i].bv_offset = off; |
|
off = 0; |
|
size -= vec_len; |
|
} |
|
/* store original address for later verification */ |
|
imu->ubuf = ubuf; |
|
imu->len = iov->iov_len; |
|
imu->nr_bvecs = nr_pages; |
|
ret = 0; |
|
done: |
|
kvfree(pages); |
|
kvfree(vmas); |
|
return ret; |
|
} |
|
|
|
static int io_buffers_map_alloc(struct io_ring_ctx *ctx, unsigned int nr_args) |
|
{ |
|
if (ctx->user_bufs) |
|
return -EBUSY; |
|
if (!nr_args || nr_args > UIO_MAXIOV) |
|
return -EINVAL; |
|
|
|
ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf), |
|
GFP_KERNEL); |
|
if (!ctx->user_bufs) |
|
return -ENOMEM; |
|
|
|
return 0; |
|
} |
|
|
|
static int io_buffer_validate(struct iovec *iov) |
|
{ |
|
/* |
|
* Don't impose further limits on the size and buffer |
|
* constraints here, we'll -EINVAL later when IO is |
|
* submitted if they are wrong. |
|
*/ |
|
if (!iov->iov_base || !iov->iov_len) |
|
return -EFAULT; |
|
|
|
/* arbitrary limit, but we need something */ |
|
if (iov->iov_len > SZ_1G) |
|
return -EFAULT; |
|
|
|
return 0; |
|
} |
|
|
|
static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, |
|
unsigned int nr_args) |
|
{ |
|
int i, ret; |
|
struct iovec iov; |
|
struct page *last_hpage = NULL; |
|
|
|
ret = io_buffers_map_alloc(ctx, nr_args); |
|
if (ret) |
|
return ret; |
|
|
|
for (i = 0; i < nr_args; i++) { |
|
struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; |
|
|
|
ret = io_copy_iov(ctx, &iov, arg, i); |
|
if (ret) |
|
break; |
|
|
|
ret = io_buffer_validate(&iov); |
|
if (ret) |
|
break; |
|
|
|
ret = io_sqe_buffer_register(ctx, &iov, imu, &last_hpage); |
|
if (ret) |
|
break; |
|
|
|
ctx->nr_user_bufs++; |
|
} |
|
|
|
if (ret) |
|
io_sqe_buffers_unregister(ctx); |
|
|
|
return ret; |
|
} |
|
|
|
static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg) |
|
{ |
|
__s32 __user *fds = arg; |
|
int fd; |
|
|
|
if (ctx->cq_ev_fd) |
|
return -EBUSY; |
|
|
|
if (copy_from_user(&fd, fds, sizeof(*fds))) |
|
return -EFAULT; |
|
|
|
ctx->cq_ev_fd = eventfd_ctx_fdget(fd); |
|
if (IS_ERR(ctx->cq_ev_fd)) { |
|
int ret = PTR_ERR(ctx->cq_ev_fd); |
|
ctx->cq_ev_fd = NULL; |
|
return ret; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int io_eventfd_unregister(struct io_ring_ctx *ctx) |
|
{ |
|
if (ctx->cq_ev_fd) { |
|
eventfd_ctx_put(ctx->cq_ev_fd); |
|
ctx->cq_ev_fd = NULL; |
|
return 0; |
|
} |
|
|
|
return -ENXIO; |
|
} |
|
|
|
static void io_destroy_buffers(struct io_ring_ctx *ctx) |
|
{ |
|
struct io_buffer *buf; |
|
unsigned long index; |
|
|
|
xa_for_each(&ctx->io_buffers, index, buf) |
|
__io_remove_buffers(ctx, buf, index, -1U); |
|
} |
|
|
|
static void io_req_cache_free(struct list_head *list, struct task_struct *tsk) |
|
{ |
|
struct io_kiocb *req, *nxt; |
|
|
|
list_for_each_entry_safe(req, nxt, list, compl.list) { |
|
if (tsk && req->task != tsk) |
|
continue; |
|
list_del(&req->compl.list); |
|
kmem_cache_free(req_cachep, req); |
|
} |
|
} |
|
|
|
static void io_req_caches_free(struct io_ring_ctx *ctx) |
|
{ |
|
struct io_submit_state *submit_state = &ctx->submit_state; |
|
struct io_comp_state *cs = &ctx->submit_state.comp; |
|
|
|
mutex_lock(&ctx->uring_lock); |
|
|
|
if (submit_state->free_reqs) { |
|
kmem_cache_free_bulk(req_cachep, submit_state->free_reqs, |
|
submit_state->reqs); |
|
submit_state->free_reqs = 0; |
|
} |
|
|
|
spin_lock_irq(&ctx->completion_lock); |
|
list_splice_init(&cs->locked_free_list, &cs->free_list); |
|
cs->locked_free_nr = 0; |
|
spin_unlock_irq(&ctx->completion_lock); |
|
|
|
io_req_cache_free(&cs->free_list, NULL); |
|
|
|
mutex_unlock(&ctx->uring_lock); |
|
} |
|
|
|
static void io_ring_ctx_free(struct io_ring_ctx *ctx) |
|
{ |
|
/* |
|
* Some may use context even when all refs and requests have been put, |
|
* and they are free to do so while still holding uring_lock or |
|
* completion_lock, see __io_req_task_submit(). Wait for them to finish. |
|
*/ |
|
mutex_lock(&ctx->uring_lock); |
|
mutex_unlock(&ctx->uring_lock); |
|
spin_lock_irq(&ctx->completion_lock); |
|
spin_unlock_irq(&ctx->completion_lock); |
|
|
|
io_sq_thread_finish(ctx); |
|
io_sqe_buffers_unregister(ctx); |
|
|
|
if (ctx->mm_account) { |
|
mmdrop(ctx->mm_account); |
|
ctx->mm_account = NULL; |
|
} |
|
|
|
mutex_lock(&ctx->uring_lock); |
|
io_sqe_files_unregister(ctx); |
|
mutex_unlock(&ctx->uring_lock); |
|
io_eventfd_unregister(ctx); |
|
io_destroy_buffers(ctx); |
|
if (ctx->sq_creds) |
|
put_cred(ctx->sq_creds); |
|
|
|
#if defined(CONFIG_UNIX) |
|
if (ctx->ring_sock) { |
|
ctx->ring_sock->file = NULL; /* so that iput() is called */ |
|
sock_release(ctx->ring_sock); |
|
} |
|
#endif |
|
|
|
io_mem_free(ctx->rings); |
|
io_mem_free(ctx->sq_sqes); |
|
|
|
percpu_ref_exit(&ctx->refs); |
|
free_uid(ctx->user); |
|
io_req_caches_free(ctx); |
|
if (ctx->hash_map) |
|
io_wq_put_hash(ctx->hash_map); |
|
kfree(ctx->cancel_hash); |
|
kfree(ctx); |
|
} |
|
|
|
static __poll_t io_uring_poll(struct file *file, poll_table *wait) |
|
{ |
|
struct io_ring_ctx *ctx = file->private_data; |
|
__poll_t mask = 0; |
|
|
|
poll_wait(file, &ctx->cq_wait, wait); |
|
/* |
|
* synchronizes with barrier from wq_has_sleeper call in |
|
* io_commit_cqring |
|
*/ |
|
smp_rmb(); |
|
if (!io_sqring_full(ctx)) |
|
mask |= EPOLLOUT | EPOLLWRNORM; |
|
|
|
/* |
|
* Don't flush cqring overflow list here, just do a simple check. |
|
* Otherwise there could possible be ABBA deadlock: |
|
* CPU0 CPU1 |
|
* ---- ---- |
|
* lock(&ctx->uring_lock); |
|
* lock(&ep->mtx); |
|
* lock(&ctx->uring_lock); |
|
* lock(&ep->mtx); |
|
* |
|
* Users may get EPOLLIN meanwhile seeing nothing in cqring, this |
|
* pushs them to do the flush. |
|
*/ |
|
if (io_cqring_events(ctx) || test_bit(0, &ctx->cq_check_overflow)) |
|
mask |= EPOLLIN | EPOLLRDNORM; |
|
|
|
return mask; |
|
} |
|
|
|
static int io_uring_fasync(int fd, struct file *file, int on) |
|
{ |
|
struct io_ring_ctx *ctx = file->private_data; |
|
|
|
return fasync_helper(fd, file, on, &ctx->cq_fasync); |
|
} |
|
|
|
static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id) |
|
{ |
|
const struct cred *creds; |
|
|
|
creds = xa_erase(&ctx->personalities, id); |
|
if (creds) { |
|
put_cred(creds); |
|
return 0; |
|
} |
|
|
|
return -EINVAL; |
|
} |
|
|
|
static inline bool io_run_ctx_fallback(struct io_ring_ctx *ctx) |
|
{ |
|
return io_run_task_work_head(&ctx->exit_task_work); |
|
} |
|
|
|
struct io_tctx_exit { |
|
struct callback_head task_work; |
|
struct completion completion; |
|
struct io_ring_ctx *ctx; |
|
}; |
|
|
|
static void io_tctx_exit_cb(struct callback_head *cb) |
|
{ |
|
struct io_uring_task *tctx = current->io_uring; |
|
struct io_tctx_exit *work; |
|
|
|
work = container_of(cb, struct io_tctx_exit, task_work); |
|
/* |
|
* When @in_idle, we're in cancellation and it's racy to remove the |
|
* node. It'll be removed by the end of cancellation, just ignore it. |
|
*/ |
|
if (!atomic_read(&tctx->in_idle)) |
|
io_uring_del_task_file((unsigned long)work->ctx); |
|
complete(&work->completion); |
|
} |
|
|
|
static bool io_cancel_ctx_cb(struct io_wq_work *work, void *data) |
|
{ |
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work); |
|
|
|
return req->ctx == data; |
|
} |
|
|
|
static void io_ring_exit_work(struct work_struct *work) |
|
{ |
|
struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, exit_work); |
|
unsigned long timeout = jiffies + HZ * 60 * 5; |
|
struct io_tctx_exit exit; |
|
struct io_tctx_node *node; |
|
int ret; |
|
|
|
/* |
|
* If we're doing polled IO and end up having requests being |
|
* submitted async (out-of-line), then completions can come in while |
|
* we're waiting for refs to drop. We need to reap these manually, |
|
* as nobody else will be looking for them. |
|
*/ |
|
do { |
|
io_uring_try_cancel_requests(ctx, NULL, NULL); |
|
if (ctx->sq_data) { |
|
struct io_sq_data *sqd = ctx->sq_data; |
|
struct task_struct *tsk; |
|
|
|
io_sq_thread_park(sqd); |
|
tsk = sqd->thread; |
|
if (tsk && tsk->io_uring && tsk->io_uring->io_wq) |
|
io_wq_cancel_cb(tsk->io_uring->io_wq, |
|
io_cancel_ctx_cb, ctx, true); |
|
io_sq_thread_unpark(sqd); |
|
} |
|
|
|
WARN_ON_ONCE(time_after(jiffies, timeout)); |
|
} while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20)); |
|
|
|
mutex_lock(&ctx->uring_lock); |
|
while (!list_empty(&ctx->tctx_list)) { |
|
WARN_ON_ONCE(time_after(jiffies, timeout)); |
|
|
|
node = list_first_entry(&ctx->tctx_list, struct io_tctx_node, |
|
ctx_node); |
|
exit.ctx = ctx; |
|
init_completion(&exit.completion); |
|
init_task_work(&exit.task_work, io_tctx_exit_cb); |
|
ret = task_work_add(node->task, &exit.task_work, TWA_SIGNAL); |
|
if (WARN_ON_ONCE(ret)) |
|
continue; |
|
wake_up_process(node->task); |
|
|
|
mutex_unlock(&ctx->uring_lock); |
|
wait_for_completion(&exit.completion); |
|
cond_resched(); |
|
mutex_lock(&ctx->uring_lock); |
|
} |
|
mutex_unlock(&ctx->uring_lock); |
|
|
|
io_ring_ctx_free(ctx); |
|
} |
|
|
|
/* Returns true if we found and killed one or more timeouts */ |
|
static bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk, |
|
struct files_struct *files) |
|
{ |
|
struct io_kiocb *req, *tmp; |
|
int canceled = 0; |
|
|
|
spin_lock_irq(&ctx->completion_lock); |
|
list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) { |
|
if (io_match_task(req, tsk, files)) { |
|
io_kill_timeout(req, -ECANCELED); |
|
canceled++; |
|
} |
|
} |
|
if (canceled != 0) |
|
io_commit_cqring(ctx); |
|
spin_unlock_irq(&ctx->completion_lock); |
|
if (canceled != 0) |
|
io_cqring_ev_posted(ctx); |
|
return canceled != 0; |
|
} |
|
|
|
static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) |
|
{ |
|
unsigned long index; |
|
struct creds *creds; |
|
|
|
mutex_lock(&ctx->uring_lock); |
|
percpu_ref_kill(&ctx->refs); |
|
/* if force is set, the ring is going away. always drop after that */ |
|
ctx->cq_overflow_flushed = 1; |
|
if (ctx->rings) |
|
__io_cqring_overflow_flush(ctx, true, NULL, NULL); |
|
xa_for_each(&ctx->personalities, index, creds) |
|
io_unregister_personality(ctx, index); |
|
mutex_unlock(&ctx->uring_lock); |
|
|
|
io_kill_timeouts(ctx, NULL, NULL); |
|
io_poll_remove_all(ctx, NULL, NULL); |
|
|
|
/* if we failed setting up the ctx, we might not have any rings */ |
|
io_iopoll_try_reap_events(ctx); |
|
|
|
INIT_WORK(&ctx->exit_work, io_ring_exit_work); |
|
/* |
|
* Use system_unbound_wq to avoid spawning tons of event kworkers |
|
* if we're exiting a ton of rings at the same time. It just adds |
|
* noise and overhead, there's no discernable change in runtime |
|
* over using system_wq. |
|
*/ |
|
queue_work(system_unbound_wq, &ctx->exit_work); |
|
} |
|
|
|
static int io_uring_release(struct inode *inode, struct file *file) |
|
{ |
|
struct io_ring_ctx *ctx = file->private_data; |
|
|
|
file->private_data = NULL; |
|
io_ring_ctx_wait_and_kill(ctx); |
|
return 0; |
|
} |
|
|
|
struct io_task_cancel { |
|
struct task_struct *task; |
|
struct files_struct *files; |
|
}; |
|
|
|
static bool io_cancel_task_cb(struct io_wq_work *work, void *data) |
|
{ |
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work); |
|
struct io_task_cancel *cancel = data; |
|
bool ret; |
|
|
|
if (cancel->files && (req->flags & REQ_F_LINK_TIMEOUT)) { |
|
unsigned long flags; |
|
struct io_ring_ctx *ctx = req->ctx; |
|
|
|
/* protect against races with linked timeouts */ |
|
spin_lock_irqsave(&ctx->completion_lock, flags); |
|
ret = io_match_task(req, cancel->task, cancel->files); |
|
spin_unlock_irqrestore(&ctx->completion_lock, flags); |
|
} else { |
|
ret = io_match_task(req, cancel->task, cancel->files); |
|
} |
|
return ret; |
|
} |
|
|
|
static bool io_cancel_defer_files(struct io_ring_ctx *ctx, |
|
struct task_struct *task, |
|
struct files_struct *files) |
|
{ |
|
struct io_defer_entry *de; |
|
LIST_HEAD(list); |
|
|
|
spin_lock_irq(&ctx->completion_lock); |
|
list_for_each_entry_reverse(de, &ctx->defer_list, list) { |
|
if (io_match_task(de->req, task, files)) { |
|
list_cut_position(&list, &ctx->defer_list, &de->list); |
|
break; |
|
} |
|
} |
|
spin_unlock_irq(&ctx->completion_lock); |
|
if (list_empty(&list)) |
|
return false; |
|
|
|
while (!list_empty(&list)) { |
|
de = list_first_entry(&list, struct io_defer_entry, list); |
|
list_del_init(&de->list); |
|
req_set_fail_links(de->req); |
|
io_put_req(de->req); |
|
io_req_complete(de->req, -ECANCELED); |
|
kfree(de); |
|
} |
|
return true; |
|
} |
|
|
|
static bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx) |
|
{ |
|
struct io_tctx_node *node; |
|
enum io_wq_cancel cret; |
|
bool ret = false; |
|
|
|
mutex_lock(&ctx->uring_lock); |
|
list_for_each_entry(node, &ctx->tctx_list, ctx_node) { |
|
struct io_uring_task *tctx = node->task->io_uring; |
|
|
|
/* |
|
* io_wq will stay alive while we hold uring_lock, because it's |
|
* killed after ctx nodes, which requires to take the lock. |
|
*/ |
|
if (!tctx || !tctx->io_wq) |
|
continue; |
|
cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_ctx_cb, ctx, true); |
|
ret |= (cret != IO_WQ_CANCEL_NOTFOUND); |
|
} |
|
mutex_unlock(&ctx->uring_lock); |
|
|
|
return ret; |
|
} |
|
|
|
static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx, |
|
struct task_struct *task, |
|
struct files_struct *files) |
|
{ |
|
struct io_task_cancel cancel = { .task = task, .files = files, }; |
|
struct io_uring_task *tctx = task ? task->io_uring : NULL; |
|
|
|
while (1) { |
|
enum io_wq_cancel cret; |
|
bool ret = false; |
|
|
|
if (!task) { |
|
ret |= io_uring_try_cancel_iowq(ctx); |
|
} else if (tctx && tctx->io_wq) { |
|
/* |
|
* Cancels requests of all rings, not only @ctx, but |
|
* it's fine as the task is in exit/exec. |
|
*/ |
|
cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_task_cb, |
|
&cancel, true); |
|
ret |= (cret != IO_WQ_CANCEL_NOTFOUND); |
|
} |
|
|
|
/* SQPOLL thread does its own polling */ |
|
if ((!(ctx->flags & IORING_SETUP_SQPOLL) && !files) || |
|
(ctx->sq_data && ctx->sq_data->thread == current)) { |
|
while (!list_empty_careful(&ctx->iopoll_list)) { |
|
io_iopoll_try_reap_events(ctx); |
|
ret = true; |
|
} |
|
} |
|
|
|
ret |= io_cancel_defer_files(ctx, task, files); |
|
ret |= io_poll_remove_all(ctx, task, files); |
|
ret |= io_kill_timeouts(ctx, task, files); |
|
ret |= io_run_task_work(); |
|
ret |= io_run_ctx_fallback(ctx); |
|
io_cqring_overflow_flush(ctx, true, task, files); |
|
if (!ret) |
|
break; |
|
cond_resched(); |
|
} |
|
} |
|
|
|
static int io_uring_count_inflight(struct io_ring_ctx *ctx, |
|
struct task_struct *task, |
|
struct files_struct *files) |
|
{ |
|
struct io_kiocb *req; |
|
int cnt = 0; |
|
|
|
spin_lock_irq(&ctx->inflight_lock); |
|
list_for_each_entry(req, &ctx->inflight_list, inflight_entry) |
|
cnt += io_match_task(req, task, files); |
|
spin_unlock_irq(&ctx->inflight_lock); |
|
return cnt; |
|
} |
|
|
|
static void io_uring_cancel_files(struct io_ring_ctx *ctx, |
|
struct task_struct *task, |
|
struct files_struct *files) |
|
{ |
|
while (!list_empty_careful(&ctx->inflight_list)) { |
|
DEFINE_WAIT(wait); |
|
int inflight; |
|
|
|
inflight = io_uring_count_inflight(ctx, task, files); |
|
if (!inflight) |
|
break; |
|
|
|
io_uring_try_cancel_requests(ctx, task, files); |
|
|
|
prepare_to_wait(&task->io_uring->wait, &wait, |
|
TASK_UNINTERRUPTIBLE); |
|
if (inflight == io_uring_count_inflight(ctx, task, files)) |
|
schedule(); |
|
finish_wait(&task->io_uring->wait, &wait); |
|
} |
|
} |
|
|
|
/* |
|
* Note that this task has used io_uring. We use it for cancelation purposes. |
|
*/ |
|
static int io_uring_add_task_file(struct io_ring_ctx *ctx) |
|
{ |
|
struct io_uring_task *tctx = current->io_uring; |
|
struct io_tctx_node *node; |
|
int ret; |
|
|
|
if (unlikely(!tctx)) { |
|
ret = io_uring_alloc_task_context(current, ctx); |
|
if (unlikely(ret)) |
|
return ret; |
|
tctx = current->io_uring; |
|
} |
|
if (tctx->last != ctx) { |
|
void *old = xa_load(&tctx->xa, (unsigned long)ctx); |
|
|
|
if (!old) { |
|
node = kmalloc(sizeof(*node), GFP_KERNEL); |
|
if (!node) |
|
return -ENOMEM; |
|
node->ctx = ctx; |
|
node->task = current; |
|
|
|
ret = xa_err(xa_store(&tctx->xa, (unsigned long)ctx, |
|
node, GFP_KERNEL)); |
|
if (ret) { |
|
kfree(node); |
|
return ret; |
|
} |
|
|
|
mutex_lock(&ctx->uring_lock); |
|
list_add(&node->ctx_node, &ctx->tctx_list); |
|
mutex_unlock(&ctx->uring_lock); |
|
} |
|
tctx->last = ctx; |
|
} |
|
return 0; |
|
} |
|
|
|
/* |
|
* Remove this io_uring_file -> task mapping. |
|
*/ |
|
static void io_uring_del_task_file(unsigned long index) |
|
{ |
|
struct io_uring_task *tctx = current->io_uring; |
|
struct io_tctx_node *node; |
|
|
|
if (!tctx) |
|
return; |
|
node = xa_erase(&tctx->xa, index); |
|
if (!node) |
|
return; |
|
|
|
WARN_ON_ONCE(current != node->task); |
|
WARN_ON_ONCE(list_empty(&node->ctx_node)); |
|
|
|
mutex_lock(&node->ctx->uring_lock); |
|
list_del(&node->ctx_node); |
|
mutex_unlock(&node->ctx->uring_lock); |
|
|
|
if (tctx->last == node->ctx) |
|
tctx->last = NULL; |
|
kfree(node); |
|
} |
|
|
|
static void io_uring_clean_tctx(struct io_uring_task *tctx) |
|
{ |
|
struct io_tctx_node *node; |
|
unsigned long index; |
|
|
|
xa_for_each(&tctx->xa, index, node) |
|
io_uring_del_task_file(index); |
|
if (tctx->io_wq) { |
|
io_wq_put_and_exit(tctx->io_wq); |
|
tctx->io_wq = NULL; |
|
} |
|
} |
|
|
|
static s64 tctx_inflight(struct io_uring_task *tctx) |
|
{ |
|
return percpu_counter_sum(&tctx->inflight); |
|
} |
|
|
|
static void io_sqpoll_cancel_cb(struct callback_head *cb) |
|
{ |
|
struct io_tctx_exit *work = container_of(cb, struct io_tctx_exit, task_work); |
|
struct io_sq_data *sqd = work->ctx->sq_data; |
|
|
|
if (sqd->thread) |
|
io_uring_cancel_sqpoll(sqd); |
|
list_del_init(&work->ctx->sqd_list); |
|
complete(&work->completion); |
|
} |
|
|
|
static void io_sqpoll_cancel_sync(struct io_ring_ctx *ctx) |
|
{ |
|
struct io_sq_data *sqd = ctx->sq_data; |
|
struct io_tctx_exit work = { .ctx = ctx, }; |
|
struct task_struct *task; |
|
|
|
io_sq_thread_park(sqd); |
|
io_sqd_update_thread_idle(sqd); |
|
task = sqd->thread; |
|
if (task) { |
|
init_completion(&work.completion); |
|
init_task_work(&work.task_work, io_sqpoll_cancel_cb); |
|
io_task_work_add_head(&sqd->park_task_work, &work.task_work); |
|
wake_up_process(task); |
|
} else { |
|
list_del_init(&ctx->sqd_list); |
|
} |
|
io_sq_thread_unpark(sqd); |
|
|
|
if (task) |
|
wait_for_completion(&work.completion); |
|
} |
|
|
|
void __io_uring_files_cancel(struct files_struct *files) |
|
{ |
|
struct io_uring_task *tctx = current->io_uring; |
|
struct io_tctx_node *node; |
|
unsigned long index; |
|
|
|
/* make sure overflow events are dropped */ |
|
atomic_inc(&tctx->in_idle); |
|
xa_for_each(&tctx->xa, index, node) { |
|
struct io_ring_ctx *ctx = node->ctx; |
|
|
|
if (ctx->sq_data) { |
|
io_sqpoll_cancel_sync(ctx); |
|
continue; |
|
} |
|
io_uring_cancel_files(ctx, current, files); |
|
if (!files) |
|
io_uring_try_cancel_requests(ctx, current, NULL); |
|
} |
|
atomic_dec(&tctx->in_idle); |
|
|
|
if (files) |
|
io_uring_clean_tctx(tctx); |
|
} |
|
|
|
/* should only be called by SQPOLL task */ |
|
static void io_uring_cancel_sqpoll(struct io_sq_data *sqd) |
|
{ |
|
struct io_uring_task *tctx = current->io_uring; |
|
struct io_ring_ctx *ctx; |
|
s64 inflight; |
|
DEFINE_WAIT(wait); |
|
|
|
if (!current->io_uring) |
|
return; |
|
WARN_ON_ONCE(!sqd || sqd->thread != current); |
|
|
|
atomic_inc(&tctx->in_idle); |
|
do { |
|
/* read completions before cancelations */ |
|
inflight = tctx_inflight(tctx); |
|
if (!inflight) |
|
break; |
|
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) |
|
io_uring_try_cancel_requests(ctx, current, NULL); |
|
|
|
prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE); |
|
/* |
|
* If we've seen completions, retry without waiting. This |
|
* avoids a race where a completion comes in before we did |
|
* prepare_to_wait(). |
|
*/ |
|
if (inflight == tctx_inflight(tctx)) |
|
schedule(); |
|
finish_wait(&tctx->wait, &wait); |
|
} while (1); |
|
atomic_dec(&tctx->in_idle); |
|
} |
|
|
|
/* |
|
* Find any io_uring fd that this task has registered or done IO on, and cancel |
|
* requests. |
|
*/ |
|
void __io_uring_task_cancel(void) |
|
{ |
|
struct io_uring_task *tctx = current->io_uring; |
|
DEFINE_WAIT(wait); |
|
s64 inflight; |
|
|
|
/* make sure overflow events are dropped */ |
|
atomic_inc(&tctx->in_idle); |
|
__io_uring_files_cancel(NULL); |
|
|
|
do { |
|
/* read completions before cancelations */ |
|
inflight = tctx_inflight(tctx); |
|
if (!inflight) |
|
break; |
|
__io_uring_files_cancel(NULL); |
|
|
|
prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE); |
|
|
|
/* |
|
* If we've seen completions, retry without waiting. This |
|
* avoids a race where a completion comes in before we did |
|
* prepare_to_wait(). |
|
*/ |
|
if (inflight == tctx_inflight(tctx)) |
|
schedule(); |
|
finish_wait(&tctx->wait, &wait); |
|
} while (1); |
|
|
|
atomic_dec(&tctx->in_idle); |
|
|
|
io_uring_clean_tctx(tctx); |
|
/* all current's requests should be gone, we can kill tctx */ |
|
__io_uring_free(current); |
|
} |
|
|
|
static void *io_uring_validate_mmap_request(struct file *file, |
|
loff_t pgoff, size_t sz) |
|
{ |
|
struct io_ring_ctx *ctx = file->private_data; |
|
loff_t offset = pgoff << PAGE_SHIFT; |
|
struct page *page; |
|
void *ptr; |
|
|
|
switch (offset) { |
|
case IORING_OFF_SQ_RING: |
|
case IORING_OFF_CQ_RING: |
|
ptr = ctx->rings; |
|
break; |
|
case IORING_OFF_SQES: |
|
ptr = ctx->sq_sqes; |
|
break; |
|
default: |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
page = virt_to_head_page(ptr); |
|
if (sz > page_size(page)) |
|
return ERR_PTR(-EINVAL); |
|
|
|
return ptr; |
|
} |
|
|
|
#ifdef CONFIG_MMU |
|
|
|
static int io_uring_mmap(struct file *file, struct vm_area_struct *vma) |
|
{ |
|
size_t sz = vma->vm_end - vma->vm_start; |
|
unsigned long pfn; |
|
void *ptr; |
|
|
|
ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz); |
|
if (IS_ERR(ptr)) |
|
return PTR_ERR(ptr); |
|
|
|
pfn = virt_to_phys(ptr) >> PAGE_SHIFT; |
|
return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot); |
|
} |
|
|
|
#else /* !CONFIG_MMU */ |
|
|
|
static int io_uring_mmap(struct file *file, struct vm_area_struct *vma) |
|
{ |
|
return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -EINVAL; |
|
} |
|
|
|
static unsigned int io_uring_nommu_mmap_capabilities(struct file *file) |
|
{ |
|
return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE; |
|
} |
|
|
|
static unsigned long io_uring_nommu_get_unmapped_area(struct file *file, |
|
unsigned long addr, unsigned long len, |
|
unsigned long pgoff, unsigned long flags) |
|
{ |
|
void *ptr; |
|
|
|
ptr = io_uring_validate_mmap_request(file, pgoff, len); |
|
if (IS_ERR(ptr)) |
|
return PTR_ERR(ptr); |
|
|
|
return (unsigned long) ptr; |
|
} |
|
|
|
#endif /* !CONFIG_MMU */ |
|
|
|
static int io_sqpoll_wait_sq(struct io_ring_ctx *ctx) |
|
{ |
|
DEFINE_WAIT(wait); |
|
|
|
do { |
|
if (!io_sqring_full(ctx)) |
|
break; |
|
prepare_to_wait(&ctx->sqo_sq_wait, &wait, TASK_INTERRUPTIBLE); |
|
|
|
if (!io_sqring_full(ctx)) |
|
break; |
|
schedule(); |
|
} while (!signal_pending(current)); |
|
|
|
finish_wait(&ctx->sqo_sq_wait, &wait); |
|
return 0; |
|
} |
|
|
|
static int io_get_ext_arg(unsigned flags, const void __user *argp, size_t *argsz, |
|
struct __kernel_timespec __user **ts, |
|
const sigset_t __user **sig) |
|
{ |
|
struct io_uring_getevents_arg arg; |
|
|
|
/* |
|
* If EXT_ARG isn't set, then we have no timespec and the argp pointer |
|
* is just a pointer to the sigset_t. |
|
*/ |
|
if (!(flags & IORING_ENTER_EXT_ARG)) { |
|
*sig = (const sigset_t __user *) argp; |
|
*ts = NULL; |
|
return 0; |
|
} |
|
|
|
/* |
|
* EXT_ARG is set - ensure we agree on the size of it and copy in our |
|
* timespec and sigset_t pointers if good. |
|
*/ |
|
if (*argsz != sizeof(arg)) |
|
return -EINVAL; |
|
if (copy_from_user(&arg, argp, sizeof(arg))) |
|
return -EFAULT; |
|
*sig = u64_to_user_ptr(arg.sigmask); |
|
*argsz = arg.sigmask_sz; |
|
*ts = u64_to_user_ptr(arg.ts); |
|
return 0; |
|
} |
|
|
|
SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, |
|
u32, min_complete, u32, flags, const void __user *, argp, |
|
size_t, argsz) |
|
{ |
|
struct io_ring_ctx *ctx; |
|
long ret = -EBADF; |
|
int submitted = 0; |
|
struct fd f; |
|
|
|
io_run_task_work(); |
|
|
|
if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP | |
|
IORING_ENTER_SQ_WAIT | IORING_ENTER_EXT_ARG)) |
|
return -EINVAL; |
|
|
|
f = fdget(fd); |
|
if (!f.file) |
|
return -EBADF; |
|
|
|
ret = -EOPNOTSUPP; |
|
if (f.file->f_op != &io_uring_fops) |
|
goto out_fput; |
|
|
|
ret = -ENXIO; |
|
ctx = f.file->private_data; |
|
if (!percpu_ref_tryget(&ctx->refs)) |
|
goto out_fput; |
|
|
|
ret = -EBADFD; |
|
if (ctx->flags & IORING_SETUP_R_DISABLED) |
|
goto out; |
|
|
|
/* |
|
* For SQ polling, the thread will do all submissions and completions. |
|
* Just return the requested submit count, and wake the thread if |
|
* we were asked to. |
|
*/ |
|
ret = 0; |
|
if (ctx->flags & IORING_SETUP_SQPOLL) { |
|
io_cqring_overflow_flush(ctx, false, NULL, NULL); |
|
|
|
ret = -EOWNERDEAD; |
|
if (unlikely(ctx->sq_data->thread == NULL)) { |
|
goto out; |
|
} |
|
if (flags & IORING_ENTER_SQ_WAKEUP) |
|
wake_up(&ctx->sq_data->wait); |
|
if (flags & IORING_ENTER_SQ_WAIT) { |
|
ret = io_sqpoll_wait_sq(ctx); |
|
if (ret) |
|
goto out; |
|
} |
|
submitted = to_submit; |
|
} else if (to_submit) { |
|
ret = io_uring_add_task_file(ctx); |
|
if (unlikely(ret)) |
|
goto out; |
|
mutex_lock(&ctx->uring_lock); |
|
submitted = io_submit_sqes(ctx, to_submit); |
|
mutex_unlock(&ctx->uring_lock); |
|
|
|
if (submitted != to_submit) |
|
goto out; |
|
} |
|
if (flags & IORING_ENTER_GETEVENTS) { |
|
const sigset_t __user *sig; |
|
struct __kernel_timespec __user *ts; |
|
|
|
ret = io_get_ext_arg(flags, argp, &argsz, &ts, &sig); |
|
if (unlikely(ret)) |
|
goto out; |
|
|
|
min_complete = min(min_complete, ctx->cq_entries); |
|
|
|
/* |
|
* When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user |
|
* space applications don't need to do io completion events |
|
* polling again, they can rely on io_sq_thread to do polling |
|
* work, which can reduce cpu usage and uring_lock contention. |
|
*/ |
|
if (ctx->flags & IORING_SETUP_IOPOLL && |
|
!(ctx->flags & IORING_SETUP_SQPOLL)) { |
|
ret = io_iopoll_check(ctx, min_complete); |
|
} else { |
|
ret = io_cqring_wait(ctx, min_complete, sig, argsz, ts); |
|
} |
|
} |
|
|
|
out: |
|
percpu_ref_put(&ctx->refs); |
|
out_fput: |
|
fdput(f); |
|
return submitted ? submitted : ret; |
|
} |
|
|
|
#ifdef CONFIG_PROC_FS |
|
static int io_uring_show_cred(struct seq_file *m, unsigned int id, |
|
const struct cred *cred) |
|
{ |
|
struct user_namespace *uns = seq_user_ns(m); |
|
struct group_info *gi; |
|
kernel_cap_t cap; |
|
unsigned __capi; |
|
int g; |
|
|
|
seq_printf(m, "%5d\n", id); |
|
seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid)); |
|
seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid)); |
|
seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid)); |
|
seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid)); |
|
seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid)); |
|
seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid)); |
|
seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid)); |
|
seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid)); |
|
seq_puts(m, "\n\tGroups:\t"); |
|
gi = cred->group_info; |
|
for (g = 0; g < gi->ngroups; g++) { |
|
seq_put_decimal_ull(m, g ? " " : "", |
|
from_kgid_munged(uns, gi->gid[g])); |
|
} |
|
seq_puts(m, "\n\tCapEff:\t"); |
|
cap = cred->cap_effective; |
|
CAP_FOR_EACH_U32(__capi) |
|
seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8); |
|
seq_putc(m, '\n'); |
|
return 0; |
|
} |
|
|
|
static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m) |
|
{ |
|
struct io_sq_data *sq = NULL; |
|
bool has_lock; |
|
int i; |
|
|
|
/* |
|
* Avoid ABBA deadlock between the seq lock and the io_uring mutex, |
|
* since fdinfo case grabs it in the opposite direction of normal use |
|
* cases. If we fail to get the lock, we just don't iterate any |
|
* structures that could be going away outside the io_uring mutex. |
|
*/ |
|
has_lock = mutex_trylock(&ctx->uring_lock); |
|
|
|
if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) { |
|
sq = ctx->sq_data; |
|
if (!sq->thread) |
|
sq = NULL; |
|
} |
|
|
|
seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1); |
|
seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1); |
|
seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files); |
|
for (i = 0; has_lock && i < ctx->nr_user_files; i++) { |
|
struct file *f = *io_fixed_file_slot(ctx->file_data, i); |
|
|
|
if (f) |
|
seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname); |
|
else |
|
seq_printf(m, "%5u: <none>\n", i); |
|
} |
|
seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs); |
|
for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) { |
|
struct io_mapped_ubuf *buf = &ctx->user_bufs[i]; |
|
|
|
seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, |
|
(unsigned int) buf->len); |
|
} |
|
if (has_lock && !xa_empty(&ctx->personalities)) { |
|
unsigned long index; |
|
const struct cred *cred; |
|
|
|
seq_printf(m, "Personalities:\n"); |
|
xa_for_each(&ctx->personalities, index, cred) |
|
io_uring_show_cred(m, index, cred); |
|
} |
|
seq_printf(m, "PollList:\n"); |
|
spin_lock_irq(&ctx->completion_lock); |
|
for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) { |
|
struct hlist_head *list = &ctx->cancel_hash[i]; |
|
struct io_kiocb *req; |
|
|
|
hlist_for_each_entry(req, list, hash_node) |
|
seq_printf(m, " op=%d, task_works=%d\n", req->opcode, |
|
req->task->task_works != NULL); |
|
} |
|
spin_unlock_irq(&ctx->completion_lock); |
|
if (has_lock) |
|
mutex_unlock(&ctx->uring_lock); |
|
} |
|
|
|
static void io_uring_show_fdinfo(struct seq_file *m, struct file *f) |
|
{ |
|
struct io_ring_ctx *ctx = f->private_data; |
|
|
|
if (percpu_ref_tryget(&ctx->refs)) { |
|
__io_uring_show_fdinfo(ctx, m); |
|
percpu_ref_put(&ctx->refs); |
|
} |
|
} |
|
#endif |
|
|
|
static const struct file_operations io_uring_fops = { |
|
.release = io_uring_release, |
|
.mmap = io_uring_mmap, |
|
#ifndef CONFIG_MMU |
|
.get_unmapped_area = io_uring_nommu_get_unmapped_area, |
|
.mmap_capabilities = io_uring_nommu_mmap_capabilities, |
|
#endif |
|
.poll = io_uring_poll, |
|
.fasync = io_uring_fasync, |
|
#ifdef CONFIG_PROC_FS |
|
.show_fdinfo = io_uring_show_fdinfo, |
|
#endif |
|
}; |
|
|
|
static int io_allocate_scq_urings(struct io_ring_ctx *ctx, |
|
struct io_uring_params *p) |
|
{ |
|
struct io_rings *rings; |
|
size_t size, sq_array_offset; |
|
|
|
/* make sure these are sane, as we already accounted them */ |
|
ctx->sq_entries = p->sq_entries; |
|
ctx->cq_entries = p->cq_entries; |
|
|
|
size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset); |
|
if (size == SIZE_MAX) |
|
return -EOVERFLOW; |
|
|
|
rings = io_mem_alloc(size); |
|
if (!rings) |
|
return -ENOMEM; |
|
|
|
ctx->rings = rings; |
|
ctx->sq_array = (u32 *)((char *)rings + sq_array_offset); |
|
rings->sq_ring_mask = p->sq_entries - 1; |
|
rings->cq_ring_mask = p->cq_entries - 1; |
|
rings->sq_ring_entries = p->sq_entries; |
|
rings->cq_ring_entries = p->cq_entries; |
|
ctx->sq_mask = rings->sq_ring_mask; |
|
ctx->cq_mask = rings->cq_ring_mask; |
|
|
|
size = array_size(sizeof(struct io_uring_sqe), p->sq_entries); |
|
if (size == SIZE_MAX) { |
|
io_mem_free(ctx->rings); |
|
ctx->rings = NULL; |
|
return -EOVERFLOW; |
|
} |
|
|
|
ctx->sq_sqes = io_mem_alloc(size); |
|
if (!ctx->sq_sqes) { |
|
io_mem_free(ctx->rings); |
|
ctx->rings = NULL; |
|
return -ENOMEM; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file) |
|
{ |
|
int ret, fd; |
|
|
|
fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC); |
|
if (fd < 0) |
|
return fd; |
|
|
|
ret = io_uring_add_task_file(ctx); |
|
if (ret) { |
|
put_unused_fd(fd); |
|
return ret; |
|
} |
|
fd_install(fd, file); |
|
return fd; |
|
} |
|
|
|
/* |
|
* Allocate an anonymous fd, this is what constitutes the application |
|
* visible backing of an io_uring instance. The application mmaps this |
|
* fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled, |
|
* we have to tie this fd to a socket for file garbage collection purposes. |
|
*/ |
|
static struct file *io_uring_get_file(struct io_ring_ctx *ctx) |
|
{ |
|
struct file *file; |
|
#if defined(CONFIG_UNIX) |
|
int ret; |
|
|
|
ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP, |
|
&ctx->ring_sock); |
|
if (ret) |
|
return ERR_PTR(ret); |
|
#endif |
|
|
|
file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx, |
|
O_RDWR | O_CLOEXEC); |
|
#if defined(CONFIG_UNIX) |
|
if (IS_ERR(file)) { |
|
sock_release(ctx->ring_sock); |
|
ctx->ring_sock = NULL; |
|
} else { |
|
ctx->ring_sock->file = file; |
|
} |
|
#endif |
|
return file; |
|
} |
|
|
|
static int io_uring_create(unsigned entries, struct io_uring_params *p, |
|
struct io_uring_params __user *params) |
|
{ |
|
struct io_ring_ctx *ctx; |
|
struct file *file; |
|
int ret; |
|
|
|
if (!entries) |
|
return -EINVAL; |
|
if (entries > IORING_MAX_ENTRIES) { |
|
if (!(p->flags & IORING_SETUP_CLAMP)) |
|
return -EINVAL; |
|
entries = IORING_MAX_ENTRIES; |
|
} |
|
|
|
/* |
|
* Use twice as many entries for the CQ ring. It's possible for the |
|
* application to drive a higher depth than the size of the SQ ring, |
|
* since the sqes are only used at submission time. This allows for |
|
* some flexibility in overcommitting a bit. If the application has |
|
* set IORING_SETUP_CQSIZE, it will have passed in the desired number |
|
* of CQ ring entries manually. |
|
*/ |
|
p->sq_entries = roundup_pow_of_two(entries); |
|
if (p->flags & IORING_SETUP_CQSIZE) { |
|
/* |
|
* If IORING_SETUP_CQSIZE is set, we do the same roundup |
|
* to a power-of-two, if it isn't already. We do NOT impose |
|
* any cq vs sq ring sizing. |
|
*/ |
|
if (!p->cq_entries) |
|
return -EINVAL; |
|
if (p->cq_entries > IORING_MAX_CQ_ENTRIES) { |
|
if (!(p->flags & IORING_SETUP_CLAMP)) |
|
return -EINVAL; |
|
p->cq_entries = IORING_MAX_CQ_ENTRIES; |
|
} |
|
p->cq_entries = roundup_pow_of_two(p->cq_entries); |
|
if (p->cq_entries < p->sq_entries) |
|
return -EINVAL; |
|
} else { |
|
p->cq_entries = 2 * p->sq_entries; |
|
} |
|
|
|
ctx = io_ring_ctx_alloc(p); |
|
if (!ctx) |
|
return -ENOMEM; |
|
ctx->compat = in_compat_syscall(); |
|
if (!capable(CAP_IPC_LOCK)) |
|
ctx->user = get_uid(current_user()); |
|
|
|
/* |
|
* This is just grabbed for accounting purposes. When a process exits, |
|
* the mm is exited and dropped before the files, hence we need to hang |
|
* on to this mm purely for the purposes of being able to unaccount |
|
* memory (locked/pinned vm). It's not used for anything else. |
|
*/ |
|
mmgrab(current->mm); |
|
ctx->mm_account = current->mm; |
|
|
|
ret = io_allocate_scq_urings(ctx, p); |
|
if (ret) |
|
goto err; |
|
|
|
ret = io_sq_offload_create(ctx, p); |
|
if (ret) |
|
goto err; |
|
|
|
memset(&p->sq_off, 0, sizeof(p->sq_off)); |
|
p->sq_off.head = offsetof(struct io_rings, sq.head); |
|
p->sq_off.tail = offsetof(struct io_rings, sq.tail); |
|
p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask); |
|
p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries); |
|
p->sq_off.flags = offsetof(struct io_rings, sq_flags); |
|
p->sq_off.dropped = offsetof(struct io_rings, sq_dropped); |
|
p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings; |
|
|
|
memset(&p->cq_off, 0, sizeof(p->cq_off)); |
|
p->cq_off.head = offsetof(struct io_rings, cq.head); |
|
p->cq_off.tail = offsetof(struct io_rings, cq.tail); |
|
p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask); |
|
p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries); |
|
p->cq_off.overflow = offsetof(struct io_rings, cq_overflow); |
|
p->cq_off.cqes = offsetof(struct io_rings, cqes); |
|
p->cq_off.flags = offsetof(struct io_rings, cq_flags); |
|
|
|
p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP | |
|
IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS | |
|
IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL | |
|
IORING_FEAT_POLL_32BITS | IORING_FEAT_SQPOLL_NONFIXED | |
|
IORING_FEAT_EXT_ARG | IORING_FEAT_NATIVE_WORKERS; |
|
|
|
if (copy_to_user(params, p, sizeof(*p))) { |
|
ret = -EFAULT; |
|
goto err; |
|
} |
|
|
|
file = io_uring_get_file(ctx); |
|
if (IS_ERR(file)) { |
|
ret = PTR_ERR(file); |
|
goto err; |
|
} |
|
|
|
/* |
|
* Install ring fd as the very last thing, so we don't risk someone |
|
* having closed it before we finish setup |
|
*/ |
|
ret = io_uring_install_fd(ctx, file); |
|
if (ret < 0) { |
|
/* fput will clean it up */ |
|
fput(file); |
|
return ret; |
|
} |
|
|
|
trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags); |
|
return ret; |
|
err: |
|
io_ring_ctx_wait_and_kill(ctx); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Sets up an aio uring context, and returns the fd. Applications asks for a |
|
* ring size, we return the actual sq/cq ring sizes (among other things) in the |
|
* params structure passed in. |
|
*/ |
|
static long io_uring_setup(u32 entries, struct io_uring_params __user *params) |
|
{ |
|
struct io_uring_params p; |
|
int i; |
|
|
|
if (copy_from_user(&p, params, sizeof(p))) |
|
return -EFAULT; |
|
for (i = 0; i < ARRAY_SIZE(p.resv); i++) { |
|
if (p.resv[i]) |
|
return -EINVAL; |
|
} |
|
|
|
if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL | |
|
IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE | |
|
IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ | |
|
IORING_SETUP_R_DISABLED)) |
|
return -EINVAL; |
|
|
|
return io_uring_create(entries, &p, params); |
|
} |
|
|
|
SYSCALL_DEFINE2(io_uring_setup, u32, entries, |
|
struct io_uring_params __user *, params) |
|
{ |
|
return io_uring_setup(entries, params); |
|
} |
|
|
|
static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args) |
|
{ |
|
struct io_uring_probe *p; |
|
size_t size; |
|
int i, ret; |
|
|
|
size = struct_size(p, ops, nr_args); |
|
if (size == SIZE_MAX) |
|
return -EOVERFLOW; |
|
p = kzalloc(size, GFP_KERNEL); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
ret = -EFAULT; |
|
if (copy_from_user(p, arg, size)) |
|
goto out; |
|
ret = -EINVAL; |
|
if (memchr_inv(p, 0, size)) |
|
goto out; |
|
|
|
p->last_op = IORING_OP_LAST - 1; |
|
if (nr_args > IORING_OP_LAST) |
|
nr_args = IORING_OP_LAST; |
|
|
|
for (i = 0; i < nr_args; i++) { |
|
p->ops[i].op = i; |
|
if (!io_op_defs[i].not_supported) |
|
p->ops[i].flags = IO_URING_OP_SUPPORTED; |
|
} |
|
p->ops_len = i; |
|
|
|
ret = 0; |
|
if (copy_to_user(arg, p, size)) |
|
ret = -EFAULT; |
|
out: |
|
kfree(p); |
|
return ret; |
|
} |
|
|
|
static int io_register_personality(struct io_ring_ctx *ctx) |
|
{ |
|
const struct cred *creds; |
|
u32 id; |
|
int ret; |
|
|
|
creds = get_current_cred(); |
|
|
|
ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)creds, |
|
XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL); |
|
if (!ret) |
|
return id; |
|
put_cred(creds); |
|
return ret; |
|
} |
|
|
|
static int io_register_restrictions(struct io_ring_ctx *ctx, void __user *arg, |
|
unsigned int nr_args) |
|
{ |
|
struct io_uring_restriction *res; |
|
size_t size; |
|
int i, ret; |
|
|
|
/* Restrictions allowed only if rings started disabled */ |
|
if (!(ctx->flags & IORING_SETUP_R_DISABLED)) |
|
return -EBADFD; |
|
|
|
/* We allow only a single restrictions registration */ |
|
if (ctx->restrictions.registered) |
|
return -EBUSY; |
|
|
|
if (!arg || nr_args > IORING_MAX_RESTRICTIONS) |
|
return -EINVAL; |
|
|
|
size = array_size(nr_args, sizeof(*res)); |
|
if (size == SIZE_MAX) |
|
return -EOVERFLOW; |
|
|
|
res = memdup_user(arg, size); |
|
if (IS_ERR(res)) |
|
return PTR_ERR(res); |
|
|
|
ret = 0; |
|
|
|
for (i = 0; i < nr_args; i++) { |
|
switch (res[i].opcode) { |
|
case IORING_RESTRICTION_REGISTER_OP: |
|
if (res[i].register_op >= IORING_REGISTER_LAST) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
__set_bit(res[i].register_op, |
|
ctx->restrictions.register_op); |
|
break; |
|
case IORING_RESTRICTION_SQE_OP: |
|
if (res[i].sqe_op >= IORING_OP_LAST) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
__set_bit(res[i].sqe_op, ctx->restrictions.sqe_op); |
|
break; |
|
case IORING_RESTRICTION_SQE_FLAGS_ALLOWED: |
|
ctx->restrictions.sqe_flags_allowed = res[i].sqe_flags; |
|
break; |
|
case IORING_RESTRICTION_SQE_FLAGS_REQUIRED: |
|
ctx->restrictions.sqe_flags_required = res[i].sqe_flags; |
|
break; |
|
default: |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
} |
|
|
|
out: |
|
/* Reset all restrictions if an error happened */ |
|
if (ret != 0) |
|
memset(&ctx->restrictions, 0, sizeof(ctx->restrictions)); |
|
else |
|
ctx->restrictions.registered = true; |
|
|
|
kfree(res); |
|
return ret; |
|
} |
|
|
|
static int io_register_enable_rings(struct io_ring_ctx *ctx) |
|
{ |
|
if (!(ctx->flags & IORING_SETUP_R_DISABLED)) |
|
return -EBADFD; |
|
|
|
if (ctx->restrictions.registered) |
|
ctx->restricted = 1; |
|
|
|
ctx->flags &= ~IORING_SETUP_R_DISABLED; |
|
if (ctx->sq_data && wq_has_sleeper(&ctx->sq_data->wait)) |
|
wake_up(&ctx->sq_data->wait); |
|
return 0; |
|
} |
|
|
|
static bool io_register_op_must_quiesce(int op) |
|
{ |
|
switch (op) { |
|
case IORING_UNREGISTER_FILES: |
|
case IORING_REGISTER_FILES_UPDATE: |
|
case IORING_REGISTER_PROBE: |
|
case IORING_REGISTER_PERSONALITY: |
|
case IORING_UNREGISTER_PERSONALITY: |
|
return false; |
|
default: |
|
return true; |
|
} |
|
} |
|
|
|
static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, |
|
void __user *arg, unsigned nr_args) |
|
__releases(ctx->uring_lock) |
|
__acquires(ctx->uring_lock) |
|
{ |
|
int ret; |
|
|
|
/* |
|
* We're inside the ring mutex, if the ref is already dying, then |
|
* someone else killed the ctx or is already going through |
|
* io_uring_register(). |
|
*/ |
|
if (percpu_ref_is_dying(&ctx->refs)) |
|
return -ENXIO; |
|
|
|
if (io_register_op_must_quiesce(opcode)) { |
|
percpu_ref_kill(&ctx->refs); |
|
|
|
/* |
|
* Drop uring mutex before waiting for references to exit. If |
|
* another thread is currently inside io_uring_enter() it might |
|
* need to grab the uring_lock to make progress. If we hold it |
|
* here across the drain wait, then we can deadlock. It's safe |
|
* to drop the mutex here, since no new references will come in |
|
* after we've killed the percpu ref. |
|
*/ |
|
mutex_unlock(&ctx->uring_lock); |
|
do { |
|
ret = wait_for_completion_interruptible(&ctx->ref_comp); |
|
if (!ret) |
|
break; |
|
ret = io_run_task_work_sig(); |
|
if (ret < 0) |
|
break; |
|
} while (1); |
|
|
|
mutex_lock(&ctx->uring_lock); |
|
|
|
if (ret) { |
|
percpu_ref_resurrect(&ctx->refs); |
|
goto out_quiesce; |
|
} |
|
} |
|
|
|
if (ctx->restricted) { |
|
if (opcode >= IORING_REGISTER_LAST) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
if (!test_bit(opcode, ctx->restrictions.register_op)) { |
|
ret = -EACCES; |
|
goto out; |
|
} |
|
} |
|
|
|
switch (opcode) { |
|
case IORING_REGISTER_BUFFERS: |
|
ret = io_sqe_buffers_register(ctx, arg, nr_args); |
|
break; |
|
case IORING_UNREGISTER_BUFFERS: |
|
ret = -EINVAL; |
|
if (arg || nr_args) |
|
break; |
|
ret = io_sqe_buffers_unregister(ctx); |
|
break; |
|
case IORING_REGISTER_FILES: |
|
ret = io_sqe_files_register(ctx, arg, nr_args); |
|
break; |
|
case IORING_UNREGISTER_FILES: |
|
ret = -EINVAL; |
|
if (arg || nr_args) |
|
break; |
|
ret = io_sqe_files_unregister(ctx); |
|
break; |
|
case IORING_REGISTER_FILES_UPDATE: |
|
ret = io_sqe_files_update(ctx, arg, nr_args); |
|
break; |
|
case IORING_REGISTER_EVENTFD: |
|
case IORING_REGISTER_EVENTFD_ASYNC: |
|
ret = -EINVAL; |
|
if (nr_args != 1) |
|
break; |
|
ret = io_eventfd_register(ctx, arg); |
|
if (ret) |
|
break; |
|
if (opcode == IORING_REGISTER_EVENTFD_ASYNC) |
|
ctx->eventfd_async = 1; |
|
else |
|
ctx->eventfd_async = 0; |
|
break; |
|
case IORING_UNREGISTER_EVENTFD: |
|
ret = -EINVAL; |
|
if (arg || nr_args) |
|
break; |
|
ret = io_eventfd_unregister(ctx); |
|
break; |
|
case IORING_REGISTER_PROBE: |
|
ret = -EINVAL; |
|
if (!arg || nr_args > 256) |
|
break; |
|
ret = io_probe(ctx, arg, nr_args); |
|
break; |
|
case IORING_REGISTER_PERSONALITY: |
|
ret = -EINVAL; |
|
if (arg || nr_args) |
|
break; |
|
ret = io_register_personality(ctx); |
|
break; |
|
case IORING_UNREGISTER_PERSONALITY: |
|
ret = -EINVAL; |
|
if (arg) |
|
break; |
|
ret = io_unregister_personality(ctx, nr_args); |
|
break; |
|
case IORING_REGISTER_ENABLE_RINGS: |
|
ret = -EINVAL; |
|
if (arg || nr_args) |
|
break; |
|
ret = io_register_enable_rings(ctx); |
|
break; |
|
case IORING_REGISTER_RESTRICTIONS: |
|
ret = io_register_restrictions(ctx, arg, nr_args); |
|
break; |
|
default: |
|
ret = -EINVAL; |
|
break; |
|
} |
|
|
|
out: |
|
if (io_register_op_must_quiesce(opcode)) { |
|
/* bring the ctx back to life */ |
|
percpu_ref_reinit(&ctx->refs); |
|
out_quiesce: |
|
reinit_completion(&ctx->ref_comp); |
|
} |
|
return ret; |
|
} |
|
|
|
SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, |
|
void __user *, arg, unsigned int, nr_args) |
|
{ |
|
struct io_ring_ctx *ctx; |
|
long ret = -EBADF; |
|
struct fd f; |
|
|
|
f = fdget(fd); |
|
if (!f.file) |
|
return -EBADF; |
|
|
|
ret = -EOPNOTSUPP; |
|
if (f.file->f_op != &io_uring_fops) |
|
goto out_fput; |
|
|
|
ctx = f.file->private_data; |
|
|
|
io_run_task_work(); |
|
|
|
mutex_lock(&ctx->uring_lock); |
|
ret = __io_uring_register(ctx, opcode, arg, nr_args); |
|
mutex_unlock(&ctx->uring_lock); |
|
trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs, |
|
ctx->cq_ev_fd != NULL, ret); |
|
out_fput: |
|
fdput(f); |
|
return ret; |
|
} |
|
|
|
static int __init io_uring_init(void) |
|
{ |
|
#define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \ |
|
BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \ |
|
BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \ |
|
} while (0) |
|
|
|
#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \ |
|
__BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename) |
|
BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64); |
|
BUILD_BUG_SQE_ELEM(0, __u8, opcode); |
|
BUILD_BUG_SQE_ELEM(1, __u8, flags); |
|
BUILD_BUG_SQE_ELEM(2, __u16, ioprio); |
|
BUILD_BUG_SQE_ELEM(4, __s32, fd); |
|
BUILD_BUG_SQE_ELEM(8, __u64, off); |
|
BUILD_BUG_SQE_ELEM(8, __u64, addr2); |
|
BUILD_BUG_SQE_ELEM(16, __u64, addr); |
|
BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in); |
|
BUILD_BUG_SQE_ELEM(24, __u32, len); |
|
BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags); |
|
BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags); |
|
BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags); |
|
BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags); |
|
BUILD_BUG_SQE_ELEM(28, /* compat */ __u16, poll_events); |
|
BUILD_BUG_SQE_ELEM(28, __u32, poll32_events); |
|
BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags); |
|
BUILD_BUG_SQE_ELEM(28, __u32, msg_flags); |
|
BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags); |
|
BUILD_BUG_SQE_ELEM(28, __u32, accept_flags); |
|
BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags); |
|
BUILD_BUG_SQE_ELEM(28, __u32, open_flags); |
|
BUILD_BUG_SQE_ELEM(28, __u32, statx_flags); |
|
BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice); |
|
BUILD_BUG_SQE_ELEM(28, __u32, splice_flags); |
|
BUILD_BUG_SQE_ELEM(32, __u64, user_data); |
|
BUILD_BUG_SQE_ELEM(40, __u16, buf_index); |
|
BUILD_BUG_SQE_ELEM(42, __u16, personality); |
|
BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in); |
|
|
|
BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST); |
|
BUILD_BUG_ON(__REQ_F_LAST_BIT >= 8 * sizeof(int)); |
|
req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC | |
|
SLAB_ACCOUNT); |
|
return 0; |
|
}; |
|
__initcall(io_uring_init);
|
|
|