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2315 lines
52 KiB
2315 lines
52 KiB
/* |
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FUSE: Filesystem in Userspace |
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Copyright (C) 2001-2008 Miklos Szeredi <[email protected]> |
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|
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This program can be distributed under the terms of the GNU GPL. |
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See the file COPYING. |
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*/ |
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|
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#include "fuse_i.h" |
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|
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#include <linux/init.h> |
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#include <linux/module.h> |
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#include <linux/poll.h> |
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#include <linux/sched/signal.h> |
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#include <linux/uio.h> |
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#include <linux/miscdevice.h> |
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#include <linux/pagemap.h> |
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#include <linux/file.h> |
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#include <linux/slab.h> |
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#include <linux/pipe_fs_i.h> |
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#include <linux/swap.h> |
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#include <linux/splice.h> |
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#include <linux/sched.h> |
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|
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MODULE_ALIAS_MISCDEV(FUSE_MINOR); |
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MODULE_ALIAS("devname:fuse"); |
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|
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/* Ordinary requests have even IDs, while interrupts IDs are odd */ |
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#define FUSE_INT_REQ_BIT (1ULL << 0) |
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#define FUSE_REQ_ID_STEP (1ULL << 1) |
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|
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static struct kmem_cache *fuse_req_cachep; |
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|
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static struct fuse_dev *fuse_get_dev(struct file *file) |
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{ |
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/* |
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* Lockless access is OK, because file->private data is set |
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* once during mount and is valid until the file is released. |
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*/ |
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return READ_ONCE(file->private_data); |
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} |
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|
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static void fuse_request_init(struct fuse_mount *fm, struct fuse_req *req) |
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{ |
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INIT_LIST_HEAD(&req->list); |
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INIT_LIST_HEAD(&req->intr_entry); |
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init_waitqueue_head(&req->waitq); |
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refcount_set(&req->count, 1); |
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__set_bit(FR_PENDING, &req->flags); |
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req->fm = fm; |
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} |
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|
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static struct fuse_req *fuse_request_alloc(struct fuse_mount *fm, gfp_t flags) |
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{ |
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struct fuse_req *req = kmem_cache_zalloc(fuse_req_cachep, flags); |
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if (req) |
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fuse_request_init(fm, req); |
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|
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return req; |
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} |
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|
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static void fuse_request_free(struct fuse_req *req) |
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{ |
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kmem_cache_free(fuse_req_cachep, req); |
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} |
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|
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static void __fuse_get_request(struct fuse_req *req) |
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{ |
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refcount_inc(&req->count); |
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} |
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|
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/* Must be called with > 1 refcount */ |
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static void __fuse_put_request(struct fuse_req *req) |
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{ |
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refcount_dec(&req->count); |
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} |
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|
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void fuse_set_initialized(struct fuse_conn *fc) |
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{ |
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/* Make sure stores before this are seen on another CPU */ |
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smp_wmb(); |
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fc->initialized = 1; |
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} |
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|
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static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background) |
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{ |
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return !fc->initialized || (for_background && fc->blocked); |
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} |
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|
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static void fuse_drop_waiting(struct fuse_conn *fc) |
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{ |
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/* |
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* lockess check of fc->connected is okay, because atomic_dec_and_test() |
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* provides a memory barrier mached with the one in fuse_wait_aborted() |
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* to ensure no wake-up is missed. |
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*/ |
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if (atomic_dec_and_test(&fc->num_waiting) && |
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!READ_ONCE(fc->connected)) { |
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/* wake up aborters */ |
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wake_up_all(&fc->blocked_waitq); |
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} |
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} |
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|
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static void fuse_put_request(struct fuse_req *req); |
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|
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static struct fuse_req *fuse_get_req(struct fuse_mount *fm, bool for_background) |
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{ |
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struct fuse_conn *fc = fm->fc; |
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struct fuse_req *req; |
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int err; |
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atomic_inc(&fc->num_waiting); |
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|
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if (fuse_block_alloc(fc, for_background)) { |
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err = -EINTR; |
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if (wait_event_killable_exclusive(fc->blocked_waitq, |
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!fuse_block_alloc(fc, for_background))) |
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goto out; |
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} |
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/* Matches smp_wmb() in fuse_set_initialized() */ |
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smp_rmb(); |
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|
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err = -ENOTCONN; |
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if (!fc->connected) |
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goto out; |
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|
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err = -ECONNREFUSED; |
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if (fc->conn_error) |
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goto out; |
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|
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req = fuse_request_alloc(fm, GFP_KERNEL); |
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err = -ENOMEM; |
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if (!req) { |
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if (for_background) |
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wake_up(&fc->blocked_waitq); |
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goto out; |
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} |
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|
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req->in.h.uid = from_kuid(fc->user_ns, current_fsuid()); |
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req->in.h.gid = from_kgid(fc->user_ns, current_fsgid()); |
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req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns); |
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|
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__set_bit(FR_WAITING, &req->flags); |
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if (for_background) |
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__set_bit(FR_BACKGROUND, &req->flags); |
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|
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if (unlikely(req->in.h.uid == ((uid_t)-1) || |
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req->in.h.gid == ((gid_t)-1))) { |
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fuse_put_request(req); |
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return ERR_PTR(-EOVERFLOW); |
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} |
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return req; |
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|
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out: |
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fuse_drop_waiting(fc); |
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return ERR_PTR(err); |
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} |
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|
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static void fuse_put_request(struct fuse_req *req) |
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{ |
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struct fuse_conn *fc = req->fm->fc; |
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|
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if (refcount_dec_and_test(&req->count)) { |
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if (test_bit(FR_BACKGROUND, &req->flags)) { |
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/* |
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* We get here in the unlikely case that a background |
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* request was allocated but not sent |
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*/ |
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spin_lock(&fc->bg_lock); |
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if (!fc->blocked) |
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wake_up(&fc->blocked_waitq); |
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spin_unlock(&fc->bg_lock); |
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} |
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|
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if (test_bit(FR_WAITING, &req->flags)) { |
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__clear_bit(FR_WAITING, &req->flags); |
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fuse_drop_waiting(fc); |
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} |
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|
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fuse_request_free(req); |
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} |
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} |
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|
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unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args) |
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{ |
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unsigned nbytes = 0; |
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unsigned i; |
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|
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for (i = 0; i < numargs; i++) |
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nbytes += args[i].size; |
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|
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return nbytes; |
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} |
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EXPORT_SYMBOL_GPL(fuse_len_args); |
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|
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u64 fuse_get_unique(struct fuse_iqueue *fiq) |
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{ |
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fiq->reqctr += FUSE_REQ_ID_STEP; |
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return fiq->reqctr; |
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} |
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EXPORT_SYMBOL_GPL(fuse_get_unique); |
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|
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static unsigned int fuse_req_hash(u64 unique) |
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{ |
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return hash_long(unique & ~FUSE_INT_REQ_BIT, FUSE_PQ_HASH_BITS); |
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} |
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|
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/** |
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* A new request is available, wake fiq->waitq |
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*/ |
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static void fuse_dev_wake_and_unlock(struct fuse_iqueue *fiq) |
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__releases(fiq->lock) |
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{ |
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wake_up(&fiq->waitq); |
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kill_fasync(&fiq->fasync, SIGIO, POLL_IN); |
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spin_unlock(&fiq->lock); |
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} |
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|
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const struct fuse_iqueue_ops fuse_dev_fiq_ops = { |
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.wake_forget_and_unlock = fuse_dev_wake_and_unlock, |
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.wake_interrupt_and_unlock = fuse_dev_wake_and_unlock, |
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.wake_pending_and_unlock = fuse_dev_wake_and_unlock, |
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}; |
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EXPORT_SYMBOL_GPL(fuse_dev_fiq_ops); |
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|
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static void queue_request_and_unlock(struct fuse_iqueue *fiq, |
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struct fuse_req *req) |
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__releases(fiq->lock) |
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{ |
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req->in.h.len = sizeof(struct fuse_in_header) + |
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fuse_len_args(req->args->in_numargs, |
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(struct fuse_arg *) req->args->in_args); |
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list_add_tail(&req->list, &fiq->pending); |
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fiq->ops->wake_pending_and_unlock(fiq); |
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} |
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|
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void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget, |
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u64 nodeid, u64 nlookup) |
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{ |
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struct fuse_iqueue *fiq = &fc->iq; |
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|
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forget->forget_one.nodeid = nodeid; |
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forget->forget_one.nlookup = nlookup; |
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spin_lock(&fiq->lock); |
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if (fiq->connected) { |
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fiq->forget_list_tail->next = forget; |
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fiq->forget_list_tail = forget; |
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fiq->ops->wake_forget_and_unlock(fiq); |
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} else { |
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kfree(forget); |
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spin_unlock(&fiq->lock); |
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} |
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} |
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|
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static void flush_bg_queue(struct fuse_conn *fc) |
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{ |
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struct fuse_iqueue *fiq = &fc->iq; |
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|
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while (fc->active_background < fc->max_background && |
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!list_empty(&fc->bg_queue)) { |
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struct fuse_req *req; |
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req = list_first_entry(&fc->bg_queue, struct fuse_req, list); |
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list_del(&req->list); |
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fc->active_background++; |
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spin_lock(&fiq->lock); |
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req->in.h.unique = fuse_get_unique(fiq); |
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queue_request_and_unlock(fiq, req); |
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} |
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} |
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|
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/* |
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* This function is called when a request is finished. Either a reply |
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* has arrived or it was aborted (and not yet sent) or some error |
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* occurred during communication with userspace, or the device file |
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* was closed. The requester thread is woken up (if still waiting), |
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* the 'end' callback is called if given, else the reference to the |
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* request is released |
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*/ |
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void fuse_request_end(struct fuse_req *req) |
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{ |
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struct fuse_mount *fm = req->fm; |
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struct fuse_conn *fc = fm->fc; |
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struct fuse_iqueue *fiq = &fc->iq; |
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if (test_and_set_bit(FR_FINISHED, &req->flags)) |
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goto put_request; |
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/* |
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* test_and_set_bit() implies smp_mb() between bit |
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* changing and below intr_entry check. Pairs with |
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* smp_mb() from queue_interrupt(). |
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*/ |
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if (!list_empty(&req->intr_entry)) { |
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spin_lock(&fiq->lock); |
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list_del_init(&req->intr_entry); |
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spin_unlock(&fiq->lock); |
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} |
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WARN_ON(test_bit(FR_PENDING, &req->flags)); |
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WARN_ON(test_bit(FR_SENT, &req->flags)); |
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if (test_bit(FR_BACKGROUND, &req->flags)) { |
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spin_lock(&fc->bg_lock); |
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clear_bit(FR_BACKGROUND, &req->flags); |
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if (fc->num_background == fc->max_background) { |
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fc->blocked = 0; |
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wake_up(&fc->blocked_waitq); |
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} else if (!fc->blocked) { |
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/* |
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* Wake up next waiter, if any. It's okay to use |
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* waitqueue_active(), as we've already synced up |
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* fc->blocked with waiters with the wake_up() call |
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* above. |
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*/ |
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if (waitqueue_active(&fc->blocked_waitq)) |
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wake_up(&fc->blocked_waitq); |
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} |
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if (fc->num_background == fc->congestion_threshold && fm->sb) { |
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clear_bdi_congested(fm->sb->s_bdi, BLK_RW_SYNC); |
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clear_bdi_congested(fm->sb->s_bdi, BLK_RW_ASYNC); |
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} |
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fc->num_background--; |
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fc->active_background--; |
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flush_bg_queue(fc); |
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spin_unlock(&fc->bg_lock); |
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} else { |
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/* Wake up waiter sleeping in request_wait_answer() */ |
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wake_up(&req->waitq); |
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} |
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|
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if (test_bit(FR_ASYNC, &req->flags)) |
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req->args->end(fm, req->args, req->out.h.error); |
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put_request: |
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fuse_put_request(req); |
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} |
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EXPORT_SYMBOL_GPL(fuse_request_end); |
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static int queue_interrupt(struct fuse_req *req) |
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{ |
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struct fuse_iqueue *fiq = &req->fm->fc->iq; |
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|
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spin_lock(&fiq->lock); |
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/* Check for we've sent request to interrupt this req */ |
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if (unlikely(!test_bit(FR_INTERRUPTED, &req->flags))) { |
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spin_unlock(&fiq->lock); |
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return -EINVAL; |
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} |
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|
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if (list_empty(&req->intr_entry)) { |
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list_add_tail(&req->intr_entry, &fiq->interrupts); |
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/* |
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* Pairs with smp_mb() implied by test_and_set_bit() |
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* from fuse_request_end(). |
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*/ |
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smp_mb(); |
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if (test_bit(FR_FINISHED, &req->flags)) { |
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list_del_init(&req->intr_entry); |
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spin_unlock(&fiq->lock); |
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return 0; |
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} |
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fiq->ops->wake_interrupt_and_unlock(fiq); |
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} else { |
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spin_unlock(&fiq->lock); |
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} |
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return 0; |
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} |
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|
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static void request_wait_answer(struct fuse_req *req) |
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{ |
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struct fuse_conn *fc = req->fm->fc; |
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struct fuse_iqueue *fiq = &fc->iq; |
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int err; |
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|
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if (!fc->no_interrupt) { |
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/* Any signal may interrupt this */ |
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err = wait_event_interruptible(req->waitq, |
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test_bit(FR_FINISHED, &req->flags)); |
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if (!err) |
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return; |
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|
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set_bit(FR_INTERRUPTED, &req->flags); |
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/* matches barrier in fuse_dev_do_read() */ |
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smp_mb__after_atomic(); |
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if (test_bit(FR_SENT, &req->flags)) |
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queue_interrupt(req); |
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} |
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|
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if (!test_bit(FR_FORCE, &req->flags)) { |
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/* Only fatal signals may interrupt this */ |
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err = wait_event_killable(req->waitq, |
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test_bit(FR_FINISHED, &req->flags)); |
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if (!err) |
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return; |
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|
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spin_lock(&fiq->lock); |
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/* Request is not yet in userspace, bail out */ |
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if (test_bit(FR_PENDING, &req->flags)) { |
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list_del(&req->list); |
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spin_unlock(&fiq->lock); |
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__fuse_put_request(req); |
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req->out.h.error = -EINTR; |
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return; |
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} |
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spin_unlock(&fiq->lock); |
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} |
|
|
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/* |
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* Either request is already in userspace, or it was forced. |
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* Wait it out. |
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*/ |
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wait_event(req->waitq, test_bit(FR_FINISHED, &req->flags)); |
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} |
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|
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static void __fuse_request_send(struct fuse_req *req) |
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{ |
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struct fuse_iqueue *fiq = &req->fm->fc->iq; |
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|
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BUG_ON(test_bit(FR_BACKGROUND, &req->flags)); |
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spin_lock(&fiq->lock); |
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if (!fiq->connected) { |
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spin_unlock(&fiq->lock); |
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req->out.h.error = -ENOTCONN; |
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} else { |
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req->in.h.unique = fuse_get_unique(fiq); |
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/* acquire extra reference, since request is still needed |
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after fuse_request_end() */ |
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__fuse_get_request(req); |
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queue_request_and_unlock(fiq, req); |
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|
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request_wait_answer(req); |
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/* Pairs with smp_wmb() in fuse_request_end() */ |
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smp_rmb(); |
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} |
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} |
|
|
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static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args) |
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{ |
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if (fc->minor < 4 && args->opcode == FUSE_STATFS) |
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args->out_args[0].size = FUSE_COMPAT_STATFS_SIZE; |
|
|
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if (fc->minor < 9) { |
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switch (args->opcode) { |
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case FUSE_LOOKUP: |
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case FUSE_CREATE: |
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case FUSE_MKNOD: |
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case FUSE_MKDIR: |
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case FUSE_SYMLINK: |
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case FUSE_LINK: |
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args->out_args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; |
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break; |
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case FUSE_GETATTR: |
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case FUSE_SETATTR: |
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args->out_args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; |
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break; |
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} |
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} |
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if (fc->minor < 12) { |
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switch (args->opcode) { |
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case FUSE_CREATE: |
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args->in_args[0].size = sizeof(struct fuse_open_in); |
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break; |
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case FUSE_MKNOD: |
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args->in_args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE; |
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break; |
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} |
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} |
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} |
|
|
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static void fuse_force_creds(struct fuse_req *req) |
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{ |
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struct fuse_conn *fc = req->fm->fc; |
|
|
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req->in.h.uid = from_kuid_munged(fc->user_ns, current_fsuid()); |
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req->in.h.gid = from_kgid_munged(fc->user_ns, current_fsgid()); |
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req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns); |
|
} |
|
|
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static void fuse_args_to_req(struct fuse_req *req, struct fuse_args *args) |
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{ |
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req->in.h.opcode = args->opcode; |
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req->in.h.nodeid = args->nodeid; |
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req->args = args; |
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if (args->end) |
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__set_bit(FR_ASYNC, &req->flags); |
|
} |
|
|
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ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args) |
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{ |
|
struct fuse_conn *fc = fm->fc; |
|
struct fuse_req *req; |
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ssize_t ret; |
|
|
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if (args->force) { |
|
atomic_inc(&fc->num_waiting); |
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req = fuse_request_alloc(fm, GFP_KERNEL | __GFP_NOFAIL); |
|
|
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if (!args->nocreds) |
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fuse_force_creds(req); |
|
|
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__set_bit(FR_WAITING, &req->flags); |
|
__set_bit(FR_FORCE, &req->flags); |
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} else { |
|
WARN_ON(args->nocreds); |
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req = fuse_get_req(fm, false); |
|
if (IS_ERR(req)) |
|
return PTR_ERR(req); |
|
} |
|
|
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/* Needs to be done after fuse_get_req() so that fc->minor is valid */ |
|
fuse_adjust_compat(fc, args); |
|
fuse_args_to_req(req, args); |
|
|
|
if (!args->noreply) |
|
__set_bit(FR_ISREPLY, &req->flags); |
|
__fuse_request_send(req); |
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ret = req->out.h.error; |
|
if (!ret && args->out_argvar) { |
|
BUG_ON(args->out_numargs == 0); |
|
ret = args->out_args[args->out_numargs - 1].size; |
|
} |
|
fuse_put_request(req); |
|
|
|
return ret; |
|
} |
|
|
|
static bool fuse_request_queue_background(struct fuse_req *req) |
|
{ |
|
struct fuse_mount *fm = req->fm; |
|
struct fuse_conn *fc = fm->fc; |
|
bool queued = false; |
|
|
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WARN_ON(!test_bit(FR_BACKGROUND, &req->flags)); |
|
if (!test_bit(FR_WAITING, &req->flags)) { |
|
__set_bit(FR_WAITING, &req->flags); |
|
atomic_inc(&fc->num_waiting); |
|
} |
|
__set_bit(FR_ISREPLY, &req->flags); |
|
spin_lock(&fc->bg_lock); |
|
if (likely(fc->connected)) { |
|
fc->num_background++; |
|
if (fc->num_background == fc->max_background) |
|
fc->blocked = 1; |
|
if (fc->num_background == fc->congestion_threshold && fm->sb) { |
|
set_bdi_congested(fm->sb->s_bdi, BLK_RW_SYNC); |
|
set_bdi_congested(fm->sb->s_bdi, BLK_RW_ASYNC); |
|
} |
|
list_add_tail(&req->list, &fc->bg_queue); |
|
flush_bg_queue(fc); |
|
queued = true; |
|
} |
|
spin_unlock(&fc->bg_lock); |
|
|
|
return queued; |
|
} |
|
|
|
int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args, |
|
gfp_t gfp_flags) |
|
{ |
|
struct fuse_req *req; |
|
|
|
if (args->force) { |
|
WARN_ON(!args->nocreds); |
|
req = fuse_request_alloc(fm, gfp_flags); |
|
if (!req) |
|
return -ENOMEM; |
|
__set_bit(FR_BACKGROUND, &req->flags); |
|
} else { |
|
WARN_ON(args->nocreds); |
|
req = fuse_get_req(fm, true); |
|
if (IS_ERR(req)) |
|
return PTR_ERR(req); |
|
} |
|
|
|
fuse_args_to_req(req, args); |
|
|
|
if (!fuse_request_queue_background(req)) { |
|
fuse_put_request(req); |
|
return -ENOTCONN; |
|
} |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(fuse_simple_background); |
|
|
|
static int fuse_simple_notify_reply(struct fuse_mount *fm, |
|
struct fuse_args *args, u64 unique) |
|
{ |
|
struct fuse_req *req; |
|
struct fuse_iqueue *fiq = &fm->fc->iq; |
|
int err = 0; |
|
|
|
req = fuse_get_req(fm, false); |
|
if (IS_ERR(req)) |
|
return PTR_ERR(req); |
|
|
|
__clear_bit(FR_ISREPLY, &req->flags); |
|
req->in.h.unique = unique; |
|
|
|
fuse_args_to_req(req, args); |
|
|
|
spin_lock(&fiq->lock); |
|
if (fiq->connected) { |
|
queue_request_and_unlock(fiq, req); |
|
} else { |
|
err = -ENODEV; |
|
spin_unlock(&fiq->lock); |
|
fuse_put_request(req); |
|
} |
|
|
|
return err; |
|
} |
|
|
|
/* |
|
* Lock the request. Up to the next unlock_request() there mustn't be |
|
* anything that could cause a page-fault. If the request was already |
|
* aborted bail out. |
|
*/ |
|
static int lock_request(struct fuse_req *req) |
|
{ |
|
int err = 0; |
|
if (req) { |
|
spin_lock(&req->waitq.lock); |
|
if (test_bit(FR_ABORTED, &req->flags)) |
|
err = -ENOENT; |
|
else |
|
set_bit(FR_LOCKED, &req->flags); |
|
spin_unlock(&req->waitq.lock); |
|
} |
|
return err; |
|
} |
|
|
|
/* |
|
* Unlock request. If it was aborted while locked, caller is responsible |
|
* for unlocking and ending the request. |
|
*/ |
|
static int unlock_request(struct fuse_req *req) |
|
{ |
|
int err = 0; |
|
if (req) { |
|
spin_lock(&req->waitq.lock); |
|
if (test_bit(FR_ABORTED, &req->flags)) |
|
err = -ENOENT; |
|
else |
|
clear_bit(FR_LOCKED, &req->flags); |
|
spin_unlock(&req->waitq.lock); |
|
} |
|
return err; |
|
} |
|
|
|
struct fuse_copy_state { |
|
int write; |
|
struct fuse_req *req; |
|
struct iov_iter *iter; |
|
struct pipe_buffer *pipebufs; |
|
struct pipe_buffer *currbuf; |
|
struct pipe_inode_info *pipe; |
|
unsigned long nr_segs; |
|
struct page *pg; |
|
unsigned len; |
|
unsigned offset; |
|
unsigned move_pages:1; |
|
}; |
|
|
|
static void fuse_copy_init(struct fuse_copy_state *cs, int write, |
|
struct iov_iter *iter) |
|
{ |
|
memset(cs, 0, sizeof(*cs)); |
|
cs->write = write; |
|
cs->iter = iter; |
|
} |
|
|
|
/* Unmap and put previous page of userspace buffer */ |
|
static void fuse_copy_finish(struct fuse_copy_state *cs) |
|
{ |
|
if (cs->currbuf) { |
|
struct pipe_buffer *buf = cs->currbuf; |
|
|
|
if (cs->write) |
|
buf->len = PAGE_SIZE - cs->len; |
|
cs->currbuf = NULL; |
|
} else if (cs->pg) { |
|
if (cs->write) { |
|
flush_dcache_page(cs->pg); |
|
set_page_dirty_lock(cs->pg); |
|
} |
|
put_page(cs->pg); |
|
} |
|
cs->pg = NULL; |
|
} |
|
|
|
/* |
|
* Get another pagefull of userspace buffer, and map it to kernel |
|
* address space, and lock request |
|
*/ |
|
static int fuse_copy_fill(struct fuse_copy_state *cs) |
|
{ |
|
struct page *page; |
|
int err; |
|
|
|
err = unlock_request(cs->req); |
|
if (err) |
|
return err; |
|
|
|
fuse_copy_finish(cs); |
|
if (cs->pipebufs) { |
|
struct pipe_buffer *buf = cs->pipebufs; |
|
|
|
if (!cs->write) { |
|
err = pipe_buf_confirm(cs->pipe, buf); |
|
if (err) |
|
return err; |
|
|
|
BUG_ON(!cs->nr_segs); |
|
cs->currbuf = buf; |
|
cs->pg = buf->page; |
|
cs->offset = buf->offset; |
|
cs->len = buf->len; |
|
cs->pipebufs++; |
|
cs->nr_segs--; |
|
} else { |
|
if (cs->nr_segs >= cs->pipe->max_usage) |
|
return -EIO; |
|
|
|
page = alloc_page(GFP_HIGHUSER); |
|
if (!page) |
|
return -ENOMEM; |
|
|
|
buf->page = page; |
|
buf->offset = 0; |
|
buf->len = 0; |
|
|
|
cs->currbuf = buf; |
|
cs->pg = page; |
|
cs->offset = 0; |
|
cs->len = PAGE_SIZE; |
|
cs->pipebufs++; |
|
cs->nr_segs++; |
|
} |
|
} else { |
|
size_t off; |
|
err = iov_iter_get_pages(cs->iter, &page, PAGE_SIZE, 1, &off); |
|
if (err < 0) |
|
return err; |
|
BUG_ON(!err); |
|
cs->len = err; |
|
cs->offset = off; |
|
cs->pg = page; |
|
iov_iter_advance(cs->iter, err); |
|
} |
|
|
|
return lock_request(cs->req); |
|
} |
|
|
|
/* Do as much copy to/from userspace buffer as we can */ |
|
static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size) |
|
{ |
|
unsigned ncpy = min(*size, cs->len); |
|
if (val) { |
|
void *pgaddr = kmap_atomic(cs->pg); |
|
void *buf = pgaddr + cs->offset; |
|
|
|
if (cs->write) |
|
memcpy(buf, *val, ncpy); |
|
else |
|
memcpy(*val, buf, ncpy); |
|
|
|
kunmap_atomic(pgaddr); |
|
*val += ncpy; |
|
} |
|
*size -= ncpy; |
|
cs->len -= ncpy; |
|
cs->offset += ncpy; |
|
return ncpy; |
|
} |
|
|
|
static int fuse_check_page(struct page *page) |
|
{ |
|
if (page_mapcount(page) || |
|
page->mapping != NULL || |
|
(page->flags & PAGE_FLAGS_CHECK_AT_PREP & |
|
~(1 << PG_locked | |
|
1 << PG_referenced | |
|
1 << PG_uptodate | |
|
1 << PG_lru | |
|
1 << PG_active | |
|
1 << PG_reclaim | |
|
1 << PG_waiters))) { |
|
dump_page(page, "fuse: trying to steal weird page"); |
|
return 1; |
|
} |
|
return 0; |
|
} |
|
|
|
static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep) |
|
{ |
|
int err; |
|
struct page *oldpage = *pagep; |
|
struct page *newpage; |
|
struct pipe_buffer *buf = cs->pipebufs; |
|
|
|
get_page(oldpage); |
|
err = unlock_request(cs->req); |
|
if (err) |
|
goto out_put_old; |
|
|
|
fuse_copy_finish(cs); |
|
|
|
err = pipe_buf_confirm(cs->pipe, buf); |
|
if (err) |
|
goto out_put_old; |
|
|
|
BUG_ON(!cs->nr_segs); |
|
cs->currbuf = buf; |
|
cs->len = buf->len; |
|
cs->pipebufs++; |
|
cs->nr_segs--; |
|
|
|
if (cs->len != PAGE_SIZE) |
|
goto out_fallback; |
|
|
|
if (!pipe_buf_try_steal(cs->pipe, buf)) |
|
goto out_fallback; |
|
|
|
newpage = buf->page; |
|
|
|
if (!PageUptodate(newpage)) |
|
SetPageUptodate(newpage); |
|
|
|
ClearPageMappedToDisk(newpage); |
|
|
|
if (fuse_check_page(newpage) != 0) |
|
goto out_fallback_unlock; |
|
|
|
/* |
|
* This is a new and locked page, it shouldn't be mapped or |
|
* have any special flags on it |
|
*/ |
|
if (WARN_ON(page_mapped(oldpage))) |
|
goto out_fallback_unlock; |
|
if (WARN_ON(page_has_private(oldpage))) |
|
goto out_fallback_unlock; |
|
if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage))) |
|
goto out_fallback_unlock; |
|
if (WARN_ON(PageMlocked(oldpage))) |
|
goto out_fallback_unlock; |
|
|
|
replace_page_cache_page(oldpage, newpage); |
|
|
|
get_page(newpage); |
|
|
|
if (!(buf->flags & PIPE_BUF_FLAG_LRU)) |
|
lru_cache_add(newpage); |
|
|
|
err = 0; |
|
spin_lock(&cs->req->waitq.lock); |
|
if (test_bit(FR_ABORTED, &cs->req->flags)) |
|
err = -ENOENT; |
|
else |
|
*pagep = newpage; |
|
spin_unlock(&cs->req->waitq.lock); |
|
|
|
if (err) { |
|
unlock_page(newpage); |
|
put_page(newpage); |
|
goto out_put_old; |
|
} |
|
|
|
unlock_page(oldpage); |
|
/* Drop ref for ap->pages[] array */ |
|
put_page(oldpage); |
|
cs->len = 0; |
|
|
|
err = 0; |
|
out_put_old: |
|
/* Drop ref obtained in this function */ |
|
put_page(oldpage); |
|
return err; |
|
|
|
out_fallback_unlock: |
|
unlock_page(newpage); |
|
out_fallback: |
|
cs->pg = buf->page; |
|
cs->offset = buf->offset; |
|
|
|
err = lock_request(cs->req); |
|
if (!err) |
|
err = 1; |
|
|
|
goto out_put_old; |
|
} |
|
|
|
static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page, |
|
unsigned offset, unsigned count) |
|
{ |
|
struct pipe_buffer *buf; |
|
int err; |
|
|
|
if (cs->nr_segs >= cs->pipe->max_usage) |
|
return -EIO; |
|
|
|
get_page(page); |
|
err = unlock_request(cs->req); |
|
if (err) { |
|
put_page(page); |
|
return err; |
|
} |
|
|
|
fuse_copy_finish(cs); |
|
|
|
buf = cs->pipebufs; |
|
buf->page = page; |
|
buf->offset = offset; |
|
buf->len = count; |
|
|
|
cs->pipebufs++; |
|
cs->nr_segs++; |
|
cs->len = 0; |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Copy a page in the request to/from the userspace buffer. Must be |
|
* done atomically |
|
*/ |
|
static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep, |
|
unsigned offset, unsigned count, int zeroing) |
|
{ |
|
int err; |
|
struct page *page = *pagep; |
|
|
|
if (page && zeroing && count < PAGE_SIZE) |
|
clear_highpage(page); |
|
|
|
while (count) { |
|
if (cs->write && cs->pipebufs && page) { |
|
return fuse_ref_page(cs, page, offset, count); |
|
} else if (!cs->len) { |
|
if (cs->move_pages && page && |
|
offset == 0 && count == PAGE_SIZE) { |
|
err = fuse_try_move_page(cs, pagep); |
|
if (err <= 0) |
|
return err; |
|
} else { |
|
err = fuse_copy_fill(cs); |
|
if (err) |
|
return err; |
|
} |
|
} |
|
if (page) { |
|
void *mapaddr = kmap_atomic(page); |
|
void *buf = mapaddr + offset; |
|
offset += fuse_copy_do(cs, &buf, &count); |
|
kunmap_atomic(mapaddr); |
|
} else |
|
offset += fuse_copy_do(cs, NULL, &count); |
|
} |
|
if (page && !cs->write) |
|
flush_dcache_page(page); |
|
return 0; |
|
} |
|
|
|
/* Copy pages in the request to/from userspace buffer */ |
|
static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes, |
|
int zeroing) |
|
{ |
|
unsigned i; |
|
struct fuse_req *req = cs->req; |
|
struct fuse_args_pages *ap = container_of(req->args, typeof(*ap), args); |
|
|
|
|
|
for (i = 0; i < ap->num_pages && (nbytes || zeroing); i++) { |
|
int err; |
|
unsigned int offset = ap->descs[i].offset; |
|
unsigned int count = min(nbytes, ap->descs[i].length); |
|
|
|
err = fuse_copy_page(cs, &ap->pages[i], offset, count, zeroing); |
|
if (err) |
|
return err; |
|
|
|
nbytes -= count; |
|
} |
|
return 0; |
|
} |
|
|
|
/* Copy a single argument in the request to/from userspace buffer */ |
|
static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size) |
|
{ |
|
while (size) { |
|
if (!cs->len) { |
|
int err = fuse_copy_fill(cs); |
|
if (err) |
|
return err; |
|
} |
|
fuse_copy_do(cs, &val, &size); |
|
} |
|
return 0; |
|
} |
|
|
|
/* Copy request arguments to/from userspace buffer */ |
|
static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs, |
|
unsigned argpages, struct fuse_arg *args, |
|
int zeroing) |
|
{ |
|
int err = 0; |
|
unsigned i; |
|
|
|
for (i = 0; !err && i < numargs; i++) { |
|
struct fuse_arg *arg = &args[i]; |
|
if (i == numargs - 1 && argpages) |
|
err = fuse_copy_pages(cs, arg->size, zeroing); |
|
else |
|
err = fuse_copy_one(cs, arg->value, arg->size); |
|
} |
|
return err; |
|
} |
|
|
|
static int forget_pending(struct fuse_iqueue *fiq) |
|
{ |
|
return fiq->forget_list_head.next != NULL; |
|
} |
|
|
|
static int request_pending(struct fuse_iqueue *fiq) |
|
{ |
|
return !list_empty(&fiq->pending) || !list_empty(&fiq->interrupts) || |
|
forget_pending(fiq); |
|
} |
|
|
|
/* |
|
* Transfer an interrupt request to userspace |
|
* |
|
* Unlike other requests this is assembled on demand, without a need |
|
* to allocate a separate fuse_req structure. |
|
* |
|
* Called with fiq->lock held, releases it |
|
*/ |
|
static int fuse_read_interrupt(struct fuse_iqueue *fiq, |
|
struct fuse_copy_state *cs, |
|
size_t nbytes, struct fuse_req *req) |
|
__releases(fiq->lock) |
|
{ |
|
struct fuse_in_header ih; |
|
struct fuse_interrupt_in arg; |
|
unsigned reqsize = sizeof(ih) + sizeof(arg); |
|
int err; |
|
|
|
list_del_init(&req->intr_entry); |
|
memset(&ih, 0, sizeof(ih)); |
|
memset(&arg, 0, sizeof(arg)); |
|
ih.len = reqsize; |
|
ih.opcode = FUSE_INTERRUPT; |
|
ih.unique = (req->in.h.unique | FUSE_INT_REQ_BIT); |
|
arg.unique = req->in.h.unique; |
|
|
|
spin_unlock(&fiq->lock); |
|
if (nbytes < reqsize) |
|
return -EINVAL; |
|
|
|
err = fuse_copy_one(cs, &ih, sizeof(ih)); |
|
if (!err) |
|
err = fuse_copy_one(cs, &arg, sizeof(arg)); |
|
fuse_copy_finish(cs); |
|
|
|
return err ? err : reqsize; |
|
} |
|
|
|
struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq, |
|
unsigned int max, |
|
unsigned int *countp) |
|
{ |
|
struct fuse_forget_link *head = fiq->forget_list_head.next; |
|
struct fuse_forget_link **newhead = &head; |
|
unsigned count; |
|
|
|
for (count = 0; *newhead != NULL && count < max; count++) |
|
newhead = &(*newhead)->next; |
|
|
|
fiq->forget_list_head.next = *newhead; |
|
*newhead = NULL; |
|
if (fiq->forget_list_head.next == NULL) |
|
fiq->forget_list_tail = &fiq->forget_list_head; |
|
|
|
if (countp != NULL) |
|
*countp = count; |
|
|
|
return head; |
|
} |
|
EXPORT_SYMBOL(fuse_dequeue_forget); |
|
|
|
static int fuse_read_single_forget(struct fuse_iqueue *fiq, |
|
struct fuse_copy_state *cs, |
|
size_t nbytes) |
|
__releases(fiq->lock) |
|
{ |
|
int err; |
|
struct fuse_forget_link *forget = fuse_dequeue_forget(fiq, 1, NULL); |
|
struct fuse_forget_in arg = { |
|
.nlookup = forget->forget_one.nlookup, |
|
}; |
|
struct fuse_in_header ih = { |
|
.opcode = FUSE_FORGET, |
|
.nodeid = forget->forget_one.nodeid, |
|
.unique = fuse_get_unique(fiq), |
|
.len = sizeof(ih) + sizeof(arg), |
|
}; |
|
|
|
spin_unlock(&fiq->lock); |
|
kfree(forget); |
|
if (nbytes < ih.len) |
|
return -EINVAL; |
|
|
|
err = fuse_copy_one(cs, &ih, sizeof(ih)); |
|
if (!err) |
|
err = fuse_copy_one(cs, &arg, sizeof(arg)); |
|
fuse_copy_finish(cs); |
|
|
|
if (err) |
|
return err; |
|
|
|
return ih.len; |
|
} |
|
|
|
static int fuse_read_batch_forget(struct fuse_iqueue *fiq, |
|
struct fuse_copy_state *cs, size_t nbytes) |
|
__releases(fiq->lock) |
|
{ |
|
int err; |
|
unsigned max_forgets; |
|
unsigned count; |
|
struct fuse_forget_link *head; |
|
struct fuse_batch_forget_in arg = { .count = 0 }; |
|
struct fuse_in_header ih = { |
|
.opcode = FUSE_BATCH_FORGET, |
|
.unique = fuse_get_unique(fiq), |
|
.len = sizeof(ih) + sizeof(arg), |
|
}; |
|
|
|
if (nbytes < ih.len) { |
|
spin_unlock(&fiq->lock); |
|
return -EINVAL; |
|
} |
|
|
|
max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one); |
|
head = fuse_dequeue_forget(fiq, max_forgets, &count); |
|
spin_unlock(&fiq->lock); |
|
|
|
arg.count = count; |
|
ih.len += count * sizeof(struct fuse_forget_one); |
|
err = fuse_copy_one(cs, &ih, sizeof(ih)); |
|
if (!err) |
|
err = fuse_copy_one(cs, &arg, sizeof(arg)); |
|
|
|
while (head) { |
|
struct fuse_forget_link *forget = head; |
|
|
|
if (!err) { |
|
err = fuse_copy_one(cs, &forget->forget_one, |
|
sizeof(forget->forget_one)); |
|
} |
|
head = forget->next; |
|
kfree(forget); |
|
} |
|
|
|
fuse_copy_finish(cs); |
|
|
|
if (err) |
|
return err; |
|
|
|
return ih.len; |
|
} |
|
|
|
static int fuse_read_forget(struct fuse_conn *fc, struct fuse_iqueue *fiq, |
|
struct fuse_copy_state *cs, |
|
size_t nbytes) |
|
__releases(fiq->lock) |
|
{ |
|
if (fc->minor < 16 || fiq->forget_list_head.next->next == NULL) |
|
return fuse_read_single_forget(fiq, cs, nbytes); |
|
else |
|
return fuse_read_batch_forget(fiq, cs, nbytes); |
|
} |
|
|
|
/* |
|
* Read a single request into the userspace filesystem's buffer. This |
|
* function waits until a request is available, then removes it from |
|
* the pending list and copies request data to userspace buffer. If |
|
* no reply is needed (FORGET) or request has been aborted or there |
|
* was an error during the copying then it's finished by calling |
|
* fuse_request_end(). Otherwise add it to the processing list, and set |
|
* the 'sent' flag. |
|
*/ |
|
static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file, |
|
struct fuse_copy_state *cs, size_t nbytes) |
|
{ |
|
ssize_t err; |
|
struct fuse_conn *fc = fud->fc; |
|
struct fuse_iqueue *fiq = &fc->iq; |
|
struct fuse_pqueue *fpq = &fud->pq; |
|
struct fuse_req *req; |
|
struct fuse_args *args; |
|
unsigned reqsize; |
|
unsigned int hash; |
|
|
|
/* |
|
* Require sane minimum read buffer - that has capacity for fixed part |
|
* of any request header + negotiated max_write room for data. |
|
* |
|
* Historically libfuse reserves 4K for fixed header room, but e.g. |
|
* GlusterFS reserves only 80 bytes |
|
* |
|
* = `sizeof(fuse_in_header) + sizeof(fuse_write_in)` |
|
* |
|
* which is the absolute minimum any sane filesystem should be using |
|
* for header room. |
|
*/ |
|
if (nbytes < max_t(size_t, FUSE_MIN_READ_BUFFER, |
|
sizeof(struct fuse_in_header) + |
|
sizeof(struct fuse_write_in) + |
|
fc->max_write)) |
|
return -EINVAL; |
|
|
|
restart: |
|
for (;;) { |
|
spin_lock(&fiq->lock); |
|
if (!fiq->connected || request_pending(fiq)) |
|
break; |
|
spin_unlock(&fiq->lock); |
|
|
|
if (file->f_flags & O_NONBLOCK) |
|
return -EAGAIN; |
|
err = wait_event_interruptible_exclusive(fiq->waitq, |
|
!fiq->connected || request_pending(fiq)); |
|
if (err) |
|
return err; |
|
} |
|
|
|
if (!fiq->connected) { |
|
err = fc->aborted ? -ECONNABORTED : -ENODEV; |
|
goto err_unlock; |
|
} |
|
|
|
if (!list_empty(&fiq->interrupts)) { |
|
req = list_entry(fiq->interrupts.next, struct fuse_req, |
|
intr_entry); |
|
return fuse_read_interrupt(fiq, cs, nbytes, req); |
|
} |
|
|
|
if (forget_pending(fiq)) { |
|
if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0) |
|
return fuse_read_forget(fc, fiq, cs, nbytes); |
|
|
|
if (fiq->forget_batch <= -8) |
|
fiq->forget_batch = 16; |
|
} |
|
|
|
req = list_entry(fiq->pending.next, struct fuse_req, list); |
|
clear_bit(FR_PENDING, &req->flags); |
|
list_del_init(&req->list); |
|
spin_unlock(&fiq->lock); |
|
|
|
args = req->args; |
|
reqsize = req->in.h.len; |
|
|
|
/* If request is too large, reply with an error and restart the read */ |
|
if (nbytes < reqsize) { |
|
req->out.h.error = -EIO; |
|
/* SETXATTR is special, since it may contain too large data */ |
|
if (args->opcode == FUSE_SETXATTR) |
|
req->out.h.error = -E2BIG; |
|
fuse_request_end(req); |
|
goto restart; |
|
} |
|
spin_lock(&fpq->lock); |
|
list_add(&req->list, &fpq->io); |
|
spin_unlock(&fpq->lock); |
|
cs->req = req; |
|
err = fuse_copy_one(cs, &req->in.h, sizeof(req->in.h)); |
|
if (!err) |
|
err = fuse_copy_args(cs, args->in_numargs, args->in_pages, |
|
(struct fuse_arg *) args->in_args, 0); |
|
fuse_copy_finish(cs); |
|
spin_lock(&fpq->lock); |
|
clear_bit(FR_LOCKED, &req->flags); |
|
if (!fpq->connected) { |
|
err = fc->aborted ? -ECONNABORTED : -ENODEV; |
|
goto out_end; |
|
} |
|
if (err) { |
|
req->out.h.error = -EIO; |
|
goto out_end; |
|
} |
|
if (!test_bit(FR_ISREPLY, &req->flags)) { |
|
err = reqsize; |
|
goto out_end; |
|
} |
|
hash = fuse_req_hash(req->in.h.unique); |
|
list_move_tail(&req->list, &fpq->processing[hash]); |
|
__fuse_get_request(req); |
|
set_bit(FR_SENT, &req->flags); |
|
spin_unlock(&fpq->lock); |
|
/* matches barrier in request_wait_answer() */ |
|
smp_mb__after_atomic(); |
|
if (test_bit(FR_INTERRUPTED, &req->flags)) |
|
queue_interrupt(req); |
|
fuse_put_request(req); |
|
|
|
return reqsize; |
|
|
|
out_end: |
|
if (!test_bit(FR_PRIVATE, &req->flags)) |
|
list_del_init(&req->list); |
|
spin_unlock(&fpq->lock); |
|
fuse_request_end(req); |
|
return err; |
|
|
|
err_unlock: |
|
spin_unlock(&fiq->lock); |
|
return err; |
|
} |
|
|
|
static int fuse_dev_open(struct inode *inode, struct file *file) |
|
{ |
|
/* |
|
* The fuse device's file's private_data is used to hold |
|
* the fuse_conn(ection) when it is mounted, and is used to |
|
* keep track of whether the file has been mounted already. |
|
*/ |
|
file->private_data = NULL; |
|
return 0; |
|
} |
|
|
|
static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to) |
|
{ |
|
struct fuse_copy_state cs; |
|
struct file *file = iocb->ki_filp; |
|
struct fuse_dev *fud = fuse_get_dev(file); |
|
|
|
if (!fud) |
|
return -EPERM; |
|
|
|
if (!iter_is_iovec(to)) |
|
return -EINVAL; |
|
|
|
fuse_copy_init(&cs, 1, to); |
|
|
|
return fuse_dev_do_read(fud, file, &cs, iov_iter_count(to)); |
|
} |
|
|
|
static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos, |
|
struct pipe_inode_info *pipe, |
|
size_t len, unsigned int flags) |
|
{ |
|
int total, ret; |
|
int page_nr = 0; |
|
struct pipe_buffer *bufs; |
|
struct fuse_copy_state cs; |
|
struct fuse_dev *fud = fuse_get_dev(in); |
|
|
|
if (!fud) |
|
return -EPERM; |
|
|
|
bufs = kvmalloc_array(pipe->max_usage, sizeof(struct pipe_buffer), |
|
GFP_KERNEL); |
|
if (!bufs) |
|
return -ENOMEM; |
|
|
|
fuse_copy_init(&cs, 1, NULL); |
|
cs.pipebufs = bufs; |
|
cs.pipe = pipe; |
|
ret = fuse_dev_do_read(fud, in, &cs, len); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (pipe_occupancy(pipe->head, pipe->tail) + cs.nr_segs > pipe->max_usage) { |
|
ret = -EIO; |
|
goto out; |
|
} |
|
|
|
for (ret = total = 0; page_nr < cs.nr_segs; total += ret) { |
|
/* |
|
* Need to be careful about this. Having buf->ops in module |
|
* code can Oops if the buffer persists after module unload. |
|
*/ |
|
bufs[page_nr].ops = &nosteal_pipe_buf_ops; |
|
bufs[page_nr].flags = 0; |
|
ret = add_to_pipe(pipe, &bufs[page_nr++]); |
|
if (unlikely(ret < 0)) |
|
break; |
|
} |
|
if (total) |
|
ret = total; |
|
out: |
|
for (; page_nr < cs.nr_segs; page_nr++) |
|
put_page(bufs[page_nr].page); |
|
|
|
kvfree(bufs); |
|
return ret; |
|
} |
|
|
|
static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size, |
|
struct fuse_copy_state *cs) |
|
{ |
|
struct fuse_notify_poll_wakeup_out outarg; |
|
int err = -EINVAL; |
|
|
|
if (size != sizeof(outarg)) |
|
goto err; |
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg)); |
|
if (err) |
|
goto err; |
|
|
|
fuse_copy_finish(cs); |
|
return fuse_notify_poll_wakeup(fc, &outarg); |
|
|
|
err: |
|
fuse_copy_finish(cs); |
|
return err; |
|
} |
|
|
|
static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size, |
|
struct fuse_copy_state *cs) |
|
{ |
|
struct fuse_notify_inval_inode_out outarg; |
|
int err = -EINVAL; |
|
|
|
if (size != sizeof(outarg)) |
|
goto err; |
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg)); |
|
if (err) |
|
goto err; |
|
fuse_copy_finish(cs); |
|
|
|
down_read(&fc->killsb); |
|
err = fuse_reverse_inval_inode(fc, outarg.ino, |
|
outarg.off, outarg.len); |
|
up_read(&fc->killsb); |
|
return err; |
|
|
|
err: |
|
fuse_copy_finish(cs); |
|
return err; |
|
} |
|
|
|
static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size, |
|
struct fuse_copy_state *cs) |
|
{ |
|
struct fuse_notify_inval_entry_out outarg; |
|
int err = -ENOMEM; |
|
char *buf; |
|
struct qstr name; |
|
|
|
buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL); |
|
if (!buf) |
|
goto err; |
|
|
|
err = -EINVAL; |
|
if (size < sizeof(outarg)) |
|
goto err; |
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg)); |
|
if (err) |
|
goto err; |
|
|
|
err = -ENAMETOOLONG; |
|
if (outarg.namelen > FUSE_NAME_MAX) |
|
goto err; |
|
|
|
err = -EINVAL; |
|
if (size != sizeof(outarg) + outarg.namelen + 1) |
|
goto err; |
|
|
|
name.name = buf; |
|
name.len = outarg.namelen; |
|
err = fuse_copy_one(cs, buf, outarg.namelen + 1); |
|
if (err) |
|
goto err; |
|
fuse_copy_finish(cs); |
|
buf[outarg.namelen] = 0; |
|
|
|
down_read(&fc->killsb); |
|
err = fuse_reverse_inval_entry(fc, outarg.parent, 0, &name); |
|
up_read(&fc->killsb); |
|
kfree(buf); |
|
return err; |
|
|
|
err: |
|
kfree(buf); |
|
fuse_copy_finish(cs); |
|
return err; |
|
} |
|
|
|
static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size, |
|
struct fuse_copy_state *cs) |
|
{ |
|
struct fuse_notify_delete_out outarg; |
|
int err = -ENOMEM; |
|
char *buf; |
|
struct qstr name; |
|
|
|
buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL); |
|
if (!buf) |
|
goto err; |
|
|
|
err = -EINVAL; |
|
if (size < sizeof(outarg)) |
|
goto err; |
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg)); |
|
if (err) |
|
goto err; |
|
|
|
err = -ENAMETOOLONG; |
|
if (outarg.namelen > FUSE_NAME_MAX) |
|
goto err; |
|
|
|
err = -EINVAL; |
|
if (size != sizeof(outarg) + outarg.namelen + 1) |
|
goto err; |
|
|
|
name.name = buf; |
|
name.len = outarg.namelen; |
|
err = fuse_copy_one(cs, buf, outarg.namelen + 1); |
|
if (err) |
|
goto err; |
|
fuse_copy_finish(cs); |
|
buf[outarg.namelen] = 0; |
|
|
|
down_read(&fc->killsb); |
|
err = fuse_reverse_inval_entry(fc, outarg.parent, outarg.child, &name); |
|
up_read(&fc->killsb); |
|
kfree(buf); |
|
return err; |
|
|
|
err: |
|
kfree(buf); |
|
fuse_copy_finish(cs); |
|
return err; |
|
} |
|
|
|
static int fuse_notify_store(struct fuse_conn *fc, unsigned int size, |
|
struct fuse_copy_state *cs) |
|
{ |
|
struct fuse_notify_store_out outarg; |
|
struct inode *inode; |
|
struct address_space *mapping; |
|
u64 nodeid; |
|
int err; |
|
pgoff_t index; |
|
unsigned int offset; |
|
unsigned int num; |
|
loff_t file_size; |
|
loff_t end; |
|
|
|
err = -EINVAL; |
|
if (size < sizeof(outarg)) |
|
goto out_finish; |
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg)); |
|
if (err) |
|
goto out_finish; |
|
|
|
err = -EINVAL; |
|
if (size - sizeof(outarg) != outarg.size) |
|
goto out_finish; |
|
|
|
nodeid = outarg.nodeid; |
|
|
|
down_read(&fc->killsb); |
|
|
|
err = -ENOENT; |
|
inode = fuse_ilookup(fc, nodeid, NULL); |
|
if (!inode) |
|
goto out_up_killsb; |
|
|
|
mapping = inode->i_mapping; |
|
index = outarg.offset >> PAGE_SHIFT; |
|
offset = outarg.offset & ~PAGE_MASK; |
|
file_size = i_size_read(inode); |
|
end = outarg.offset + outarg.size; |
|
if (end > file_size) { |
|
file_size = end; |
|
fuse_write_update_size(inode, file_size); |
|
} |
|
|
|
num = outarg.size; |
|
while (num) { |
|
struct page *page; |
|
unsigned int this_num; |
|
|
|
err = -ENOMEM; |
|
page = find_or_create_page(mapping, index, |
|
mapping_gfp_mask(mapping)); |
|
if (!page) |
|
goto out_iput; |
|
|
|
this_num = min_t(unsigned, num, PAGE_SIZE - offset); |
|
err = fuse_copy_page(cs, &page, offset, this_num, 0); |
|
if (!err && offset == 0 && |
|
(this_num == PAGE_SIZE || file_size == end)) |
|
SetPageUptodate(page); |
|
unlock_page(page); |
|
put_page(page); |
|
|
|
if (err) |
|
goto out_iput; |
|
|
|
num -= this_num; |
|
offset = 0; |
|
index++; |
|
} |
|
|
|
err = 0; |
|
|
|
out_iput: |
|
iput(inode); |
|
out_up_killsb: |
|
up_read(&fc->killsb); |
|
out_finish: |
|
fuse_copy_finish(cs); |
|
return err; |
|
} |
|
|
|
struct fuse_retrieve_args { |
|
struct fuse_args_pages ap; |
|
struct fuse_notify_retrieve_in inarg; |
|
}; |
|
|
|
static void fuse_retrieve_end(struct fuse_mount *fm, struct fuse_args *args, |
|
int error) |
|
{ |
|
struct fuse_retrieve_args *ra = |
|
container_of(args, typeof(*ra), ap.args); |
|
|
|
release_pages(ra->ap.pages, ra->ap.num_pages); |
|
kfree(ra); |
|
} |
|
|
|
static int fuse_retrieve(struct fuse_mount *fm, struct inode *inode, |
|
struct fuse_notify_retrieve_out *outarg) |
|
{ |
|
int err; |
|
struct address_space *mapping = inode->i_mapping; |
|
pgoff_t index; |
|
loff_t file_size; |
|
unsigned int num; |
|
unsigned int offset; |
|
size_t total_len = 0; |
|
unsigned int num_pages; |
|
struct fuse_conn *fc = fm->fc; |
|
struct fuse_retrieve_args *ra; |
|
size_t args_size = sizeof(*ra); |
|
struct fuse_args_pages *ap; |
|
struct fuse_args *args; |
|
|
|
offset = outarg->offset & ~PAGE_MASK; |
|
file_size = i_size_read(inode); |
|
|
|
num = min(outarg->size, fc->max_write); |
|
if (outarg->offset > file_size) |
|
num = 0; |
|
else if (outarg->offset + num > file_size) |
|
num = file_size - outarg->offset; |
|
|
|
num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; |
|
num_pages = min(num_pages, fc->max_pages); |
|
|
|
args_size += num_pages * (sizeof(ap->pages[0]) + sizeof(ap->descs[0])); |
|
|
|
ra = kzalloc(args_size, GFP_KERNEL); |
|
if (!ra) |
|
return -ENOMEM; |
|
|
|
ap = &ra->ap; |
|
ap->pages = (void *) (ra + 1); |
|
ap->descs = (void *) (ap->pages + num_pages); |
|
|
|
args = &ap->args; |
|
args->nodeid = outarg->nodeid; |
|
args->opcode = FUSE_NOTIFY_REPLY; |
|
args->in_numargs = 2; |
|
args->in_pages = true; |
|
args->end = fuse_retrieve_end; |
|
|
|
index = outarg->offset >> PAGE_SHIFT; |
|
|
|
while (num && ap->num_pages < num_pages) { |
|
struct page *page; |
|
unsigned int this_num; |
|
|
|
page = find_get_page(mapping, index); |
|
if (!page) |
|
break; |
|
|
|
this_num = min_t(unsigned, num, PAGE_SIZE - offset); |
|
ap->pages[ap->num_pages] = page; |
|
ap->descs[ap->num_pages].offset = offset; |
|
ap->descs[ap->num_pages].length = this_num; |
|
ap->num_pages++; |
|
|
|
offset = 0; |
|
num -= this_num; |
|
total_len += this_num; |
|
index++; |
|
} |
|
ra->inarg.offset = outarg->offset; |
|
ra->inarg.size = total_len; |
|
args->in_args[0].size = sizeof(ra->inarg); |
|
args->in_args[0].value = &ra->inarg; |
|
args->in_args[1].size = total_len; |
|
|
|
err = fuse_simple_notify_reply(fm, args, outarg->notify_unique); |
|
if (err) |
|
fuse_retrieve_end(fm, args, err); |
|
|
|
return err; |
|
} |
|
|
|
static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size, |
|
struct fuse_copy_state *cs) |
|
{ |
|
struct fuse_notify_retrieve_out outarg; |
|
struct fuse_mount *fm; |
|
struct inode *inode; |
|
u64 nodeid; |
|
int err; |
|
|
|
err = -EINVAL; |
|
if (size != sizeof(outarg)) |
|
goto copy_finish; |
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg)); |
|
if (err) |
|
goto copy_finish; |
|
|
|
fuse_copy_finish(cs); |
|
|
|
down_read(&fc->killsb); |
|
err = -ENOENT; |
|
nodeid = outarg.nodeid; |
|
|
|
inode = fuse_ilookup(fc, nodeid, &fm); |
|
if (inode) { |
|
err = fuse_retrieve(fm, inode, &outarg); |
|
iput(inode); |
|
} |
|
up_read(&fc->killsb); |
|
|
|
return err; |
|
|
|
copy_finish: |
|
fuse_copy_finish(cs); |
|
return err; |
|
} |
|
|
|
static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code, |
|
unsigned int size, struct fuse_copy_state *cs) |
|
{ |
|
/* Don't try to move pages (yet) */ |
|
cs->move_pages = 0; |
|
|
|
switch (code) { |
|
case FUSE_NOTIFY_POLL: |
|
return fuse_notify_poll(fc, size, cs); |
|
|
|
case FUSE_NOTIFY_INVAL_INODE: |
|
return fuse_notify_inval_inode(fc, size, cs); |
|
|
|
case FUSE_NOTIFY_INVAL_ENTRY: |
|
return fuse_notify_inval_entry(fc, size, cs); |
|
|
|
case FUSE_NOTIFY_STORE: |
|
return fuse_notify_store(fc, size, cs); |
|
|
|
case FUSE_NOTIFY_RETRIEVE: |
|
return fuse_notify_retrieve(fc, size, cs); |
|
|
|
case FUSE_NOTIFY_DELETE: |
|
return fuse_notify_delete(fc, size, cs); |
|
|
|
default: |
|
fuse_copy_finish(cs); |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
/* Look up request on processing list by unique ID */ |
|
static struct fuse_req *request_find(struct fuse_pqueue *fpq, u64 unique) |
|
{ |
|
unsigned int hash = fuse_req_hash(unique); |
|
struct fuse_req *req; |
|
|
|
list_for_each_entry(req, &fpq->processing[hash], list) { |
|
if (req->in.h.unique == unique) |
|
return req; |
|
} |
|
return NULL; |
|
} |
|
|
|
static int copy_out_args(struct fuse_copy_state *cs, struct fuse_args *args, |
|
unsigned nbytes) |
|
{ |
|
unsigned reqsize = sizeof(struct fuse_out_header); |
|
|
|
reqsize += fuse_len_args(args->out_numargs, args->out_args); |
|
|
|
if (reqsize < nbytes || (reqsize > nbytes && !args->out_argvar)) |
|
return -EINVAL; |
|
else if (reqsize > nbytes) { |
|
struct fuse_arg *lastarg = &args->out_args[args->out_numargs-1]; |
|
unsigned diffsize = reqsize - nbytes; |
|
|
|
if (diffsize > lastarg->size) |
|
return -EINVAL; |
|
lastarg->size -= diffsize; |
|
} |
|
return fuse_copy_args(cs, args->out_numargs, args->out_pages, |
|
args->out_args, args->page_zeroing); |
|
} |
|
|
|
/* |
|
* Write a single reply to a request. First the header is copied from |
|
* the write buffer. The request is then searched on the processing |
|
* list by the unique ID found in the header. If found, then remove |
|
* it from the list and copy the rest of the buffer to the request. |
|
* The request is finished by calling fuse_request_end(). |
|
*/ |
|
static ssize_t fuse_dev_do_write(struct fuse_dev *fud, |
|
struct fuse_copy_state *cs, size_t nbytes) |
|
{ |
|
int err; |
|
struct fuse_conn *fc = fud->fc; |
|
struct fuse_pqueue *fpq = &fud->pq; |
|
struct fuse_req *req; |
|
struct fuse_out_header oh; |
|
|
|
err = -EINVAL; |
|
if (nbytes < sizeof(struct fuse_out_header)) |
|
goto out; |
|
|
|
err = fuse_copy_one(cs, &oh, sizeof(oh)); |
|
if (err) |
|
goto copy_finish; |
|
|
|
err = -EINVAL; |
|
if (oh.len != nbytes) |
|
goto copy_finish; |
|
|
|
/* |
|
* Zero oh.unique indicates unsolicited notification message |
|
* and error contains notification code. |
|
*/ |
|
if (!oh.unique) { |
|
err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs); |
|
goto out; |
|
} |
|
|
|
err = -EINVAL; |
|
if (oh.error <= -1000 || oh.error > 0) |
|
goto copy_finish; |
|
|
|
spin_lock(&fpq->lock); |
|
req = NULL; |
|
if (fpq->connected) |
|
req = request_find(fpq, oh.unique & ~FUSE_INT_REQ_BIT); |
|
|
|
err = -ENOENT; |
|
if (!req) { |
|
spin_unlock(&fpq->lock); |
|
goto copy_finish; |
|
} |
|
|
|
/* Is it an interrupt reply ID? */ |
|
if (oh.unique & FUSE_INT_REQ_BIT) { |
|
__fuse_get_request(req); |
|
spin_unlock(&fpq->lock); |
|
|
|
err = 0; |
|
if (nbytes != sizeof(struct fuse_out_header)) |
|
err = -EINVAL; |
|
else if (oh.error == -ENOSYS) |
|
fc->no_interrupt = 1; |
|
else if (oh.error == -EAGAIN) |
|
err = queue_interrupt(req); |
|
|
|
fuse_put_request(req); |
|
|
|
goto copy_finish; |
|
} |
|
|
|
clear_bit(FR_SENT, &req->flags); |
|
list_move(&req->list, &fpq->io); |
|
req->out.h = oh; |
|
set_bit(FR_LOCKED, &req->flags); |
|
spin_unlock(&fpq->lock); |
|
cs->req = req; |
|
if (!req->args->page_replace) |
|
cs->move_pages = 0; |
|
|
|
if (oh.error) |
|
err = nbytes != sizeof(oh) ? -EINVAL : 0; |
|
else |
|
err = copy_out_args(cs, req->args, nbytes); |
|
fuse_copy_finish(cs); |
|
|
|
spin_lock(&fpq->lock); |
|
clear_bit(FR_LOCKED, &req->flags); |
|
if (!fpq->connected) |
|
err = -ENOENT; |
|
else if (err) |
|
req->out.h.error = -EIO; |
|
if (!test_bit(FR_PRIVATE, &req->flags)) |
|
list_del_init(&req->list); |
|
spin_unlock(&fpq->lock); |
|
|
|
fuse_request_end(req); |
|
out: |
|
return err ? err : nbytes; |
|
|
|
copy_finish: |
|
fuse_copy_finish(cs); |
|
goto out; |
|
} |
|
|
|
static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from) |
|
{ |
|
struct fuse_copy_state cs; |
|
struct fuse_dev *fud = fuse_get_dev(iocb->ki_filp); |
|
|
|
if (!fud) |
|
return -EPERM; |
|
|
|
if (!iter_is_iovec(from)) |
|
return -EINVAL; |
|
|
|
fuse_copy_init(&cs, 0, from); |
|
|
|
return fuse_dev_do_write(fud, &cs, iov_iter_count(from)); |
|
} |
|
|
|
static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe, |
|
struct file *out, loff_t *ppos, |
|
size_t len, unsigned int flags) |
|
{ |
|
unsigned int head, tail, mask, count; |
|
unsigned nbuf; |
|
unsigned idx; |
|
struct pipe_buffer *bufs; |
|
struct fuse_copy_state cs; |
|
struct fuse_dev *fud; |
|
size_t rem; |
|
ssize_t ret; |
|
|
|
fud = fuse_get_dev(out); |
|
if (!fud) |
|
return -EPERM; |
|
|
|
pipe_lock(pipe); |
|
|
|
head = pipe->head; |
|
tail = pipe->tail; |
|
mask = pipe->ring_size - 1; |
|
count = head - tail; |
|
|
|
bufs = kvmalloc_array(count, sizeof(struct pipe_buffer), GFP_KERNEL); |
|
if (!bufs) { |
|
pipe_unlock(pipe); |
|
return -ENOMEM; |
|
} |
|
|
|
nbuf = 0; |
|
rem = 0; |
|
for (idx = tail; idx != head && rem < len; idx++) |
|
rem += pipe->bufs[idx & mask].len; |
|
|
|
ret = -EINVAL; |
|
if (rem < len) |
|
goto out_free; |
|
|
|
rem = len; |
|
while (rem) { |
|
struct pipe_buffer *ibuf; |
|
struct pipe_buffer *obuf; |
|
|
|
if (WARN_ON(nbuf >= count || tail == head)) |
|
goto out_free; |
|
|
|
ibuf = &pipe->bufs[tail & mask]; |
|
obuf = &bufs[nbuf]; |
|
|
|
if (rem >= ibuf->len) { |
|
*obuf = *ibuf; |
|
ibuf->ops = NULL; |
|
tail++; |
|
pipe->tail = tail; |
|
} else { |
|
if (!pipe_buf_get(pipe, ibuf)) |
|
goto out_free; |
|
|
|
*obuf = *ibuf; |
|
obuf->flags &= ~PIPE_BUF_FLAG_GIFT; |
|
obuf->len = rem; |
|
ibuf->offset += obuf->len; |
|
ibuf->len -= obuf->len; |
|
} |
|
nbuf++; |
|
rem -= obuf->len; |
|
} |
|
pipe_unlock(pipe); |
|
|
|
fuse_copy_init(&cs, 0, NULL); |
|
cs.pipebufs = bufs; |
|
cs.nr_segs = nbuf; |
|
cs.pipe = pipe; |
|
|
|
if (flags & SPLICE_F_MOVE) |
|
cs.move_pages = 1; |
|
|
|
ret = fuse_dev_do_write(fud, &cs, len); |
|
|
|
pipe_lock(pipe); |
|
out_free: |
|
for (idx = 0; idx < nbuf; idx++) |
|
pipe_buf_release(pipe, &bufs[idx]); |
|
pipe_unlock(pipe); |
|
|
|
kvfree(bufs); |
|
return ret; |
|
} |
|
|
|
static __poll_t fuse_dev_poll(struct file *file, poll_table *wait) |
|
{ |
|
__poll_t mask = EPOLLOUT | EPOLLWRNORM; |
|
struct fuse_iqueue *fiq; |
|
struct fuse_dev *fud = fuse_get_dev(file); |
|
|
|
if (!fud) |
|
return EPOLLERR; |
|
|
|
fiq = &fud->fc->iq; |
|
poll_wait(file, &fiq->waitq, wait); |
|
|
|
spin_lock(&fiq->lock); |
|
if (!fiq->connected) |
|
mask = EPOLLERR; |
|
else if (request_pending(fiq)) |
|
mask |= EPOLLIN | EPOLLRDNORM; |
|
spin_unlock(&fiq->lock); |
|
|
|
return mask; |
|
} |
|
|
|
/* Abort all requests on the given list (pending or processing) */ |
|
static void end_requests(struct list_head *head) |
|
{ |
|
while (!list_empty(head)) { |
|
struct fuse_req *req; |
|
req = list_entry(head->next, struct fuse_req, list); |
|
req->out.h.error = -ECONNABORTED; |
|
clear_bit(FR_SENT, &req->flags); |
|
list_del_init(&req->list); |
|
fuse_request_end(req); |
|
} |
|
} |
|
|
|
static void end_polls(struct fuse_conn *fc) |
|
{ |
|
struct rb_node *p; |
|
|
|
p = rb_first(&fc->polled_files); |
|
|
|
while (p) { |
|
struct fuse_file *ff; |
|
ff = rb_entry(p, struct fuse_file, polled_node); |
|
wake_up_interruptible_all(&ff->poll_wait); |
|
|
|
p = rb_next(p); |
|
} |
|
} |
|
|
|
/* |
|
* Abort all requests. |
|
* |
|
* Emergency exit in case of a malicious or accidental deadlock, or just a hung |
|
* filesystem. |
|
* |
|
* The same effect is usually achievable through killing the filesystem daemon |
|
* and all users of the filesystem. The exception is the combination of an |
|
* asynchronous request and the tricky deadlock (see |
|
* Documentation/filesystems/fuse.rst). |
|
* |
|
* Aborting requests under I/O goes as follows: 1: Separate out unlocked |
|
* requests, they should be finished off immediately. Locked requests will be |
|
* finished after unlock; see unlock_request(). 2: Finish off the unlocked |
|
* requests. It is possible that some request will finish before we can. This |
|
* is OK, the request will in that case be removed from the list before we touch |
|
* it. |
|
*/ |
|
void fuse_abort_conn(struct fuse_conn *fc) |
|
{ |
|
struct fuse_iqueue *fiq = &fc->iq; |
|
|
|
spin_lock(&fc->lock); |
|
if (fc->connected) { |
|
struct fuse_dev *fud; |
|
struct fuse_req *req, *next; |
|
LIST_HEAD(to_end); |
|
unsigned int i; |
|
|
|
/* Background queuing checks fc->connected under bg_lock */ |
|
spin_lock(&fc->bg_lock); |
|
fc->connected = 0; |
|
spin_unlock(&fc->bg_lock); |
|
|
|
fuse_set_initialized(fc); |
|
list_for_each_entry(fud, &fc->devices, entry) { |
|
struct fuse_pqueue *fpq = &fud->pq; |
|
|
|
spin_lock(&fpq->lock); |
|
fpq->connected = 0; |
|
list_for_each_entry_safe(req, next, &fpq->io, list) { |
|
req->out.h.error = -ECONNABORTED; |
|
spin_lock(&req->waitq.lock); |
|
set_bit(FR_ABORTED, &req->flags); |
|
if (!test_bit(FR_LOCKED, &req->flags)) { |
|
set_bit(FR_PRIVATE, &req->flags); |
|
__fuse_get_request(req); |
|
list_move(&req->list, &to_end); |
|
} |
|
spin_unlock(&req->waitq.lock); |
|
} |
|
for (i = 0; i < FUSE_PQ_HASH_SIZE; i++) |
|
list_splice_tail_init(&fpq->processing[i], |
|
&to_end); |
|
spin_unlock(&fpq->lock); |
|
} |
|
spin_lock(&fc->bg_lock); |
|
fc->blocked = 0; |
|
fc->max_background = UINT_MAX; |
|
flush_bg_queue(fc); |
|
spin_unlock(&fc->bg_lock); |
|
|
|
spin_lock(&fiq->lock); |
|
fiq->connected = 0; |
|
list_for_each_entry(req, &fiq->pending, list) |
|
clear_bit(FR_PENDING, &req->flags); |
|
list_splice_tail_init(&fiq->pending, &to_end); |
|
while (forget_pending(fiq)) |
|
kfree(fuse_dequeue_forget(fiq, 1, NULL)); |
|
wake_up_all(&fiq->waitq); |
|
spin_unlock(&fiq->lock); |
|
kill_fasync(&fiq->fasync, SIGIO, POLL_IN); |
|
end_polls(fc); |
|
wake_up_all(&fc->blocked_waitq); |
|
spin_unlock(&fc->lock); |
|
|
|
end_requests(&to_end); |
|
} else { |
|
spin_unlock(&fc->lock); |
|
} |
|
} |
|
EXPORT_SYMBOL_GPL(fuse_abort_conn); |
|
|
|
void fuse_wait_aborted(struct fuse_conn *fc) |
|
{ |
|
/* matches implicit memory barrier in fuse_drop_waiting() */ |
|
smp_mb(); |
|
wait_event(fc->blocked_waitq, atomic_read(&fc->num_waiting) == 0); |
|
} |
|
|
|
int fuse_dev_release(struct inode *inode, struct file *file) |
|
{ |
|
struct fuse_dev *fud = fuse_get_dev(file); |
|
|
|
if (fud) { |
|
struct fuse_conn *fc = fud->fc; |
|
struct fuse_pqueue *fpq = &fud->pq; |
|
LIST_HEAD(to_end); |
|
unsigned int i; |
|
|
|
spin_lock(&fpq->lock); |
|
WARN_ON(!list_empty(&fpq->io)); |
|
for (i = 0; i < FUSE_PQ_HASH_SIZE; i++) |
|
list_splice_init(&fpq->processing[i], &to_end); |
|
spin_unlock(&fpq->lock); |
|
|
|
end_requests(&to_end); |
|
|
|
/* Are we the last open device? */ |
|
if (atomic_dec_and_test(&fc->dev_count)) { |
|
WARN_ON(fc->iq.fasync != NULL); |
|
fuse_abort_conn(fc); |
|
} |
|
fuse_dev_free(fud); |
|
} |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(fuse_dev_release); |
|
|
|
static int fuse_dev_fasync(int fd, struct file *file, int on) |
|
{ |
|
struct fuse_dev *fud = fuse_get_dev(file); |
|
|
|
if (!fud) |
|
return -EPERM; |
|
|
|
/* No locking - fasync_helper does its own locking */ |
|
return fasync_helper(fd, file, on, &fud->fc->iq.fasync); |
|
} |
|
|
|
static int fuse_device_clone(struct fuse_conn *fc, struct file *new) |
|
{ |
|
struct fuse_dev *fud; |
|
|
|
if (new->private_data) |
|
return -EINVAL; |
|
|
|
fud = fuse_dev_alloc_install(fc); |
|
if (!fud) |
|
return -ENOMEM; |
|
|
|
new->private_data = fud; |
|
atomic_inc(&fc->dev_count); |
|
|
|
return 0; |
|
} |
|
|
|
static long fuse_dev_ioctl(struct file *file, unsigned int cmd, |
|
unsigned long arg) |
|
{ |
|
int res; |
|
int oldfd; |
|
struct fuse_dev *fud = NULL; |
|
|
|
switch (cmd) { |
|
case FUSE_DEV_IOC_CLONE: |
|
res = -EFAULT; |
|
if (!get_user(oldfd, (__u32 __user *)arg)) { |
|
struct file *old = fget(oldfd); |
|
|
|
res = -EINVAL; |
|
if (old) { |
|
/* |
|
* Check against file->f_op because CUSE |
|
* uses the same ioctl handler. |
|
*/ |
|
if (old->f_op == file->f_op && |
|
old->f_cred->user_ns == file->f_cred->user_ns) |
|
fud = fuse_get_dev(old); |
|
|
|
if (fud) { |
|
mutex_lock(&fuse_mutex); |
|
res = fuse_device_clone(fud->fc, file); |
|
mutex_unlock(&fuse_mutex); |
|
} |
|
fput(old); |
|
} |
|
} |
|
break; |
|
default: |
|
res = -ENOTTY; |
|
break; |
|
} |
|
return res; |
|
} |
|
|
|
const struct file_operations fuse_dev_operations = { |
|
.owner = THIS_MODULE, |
|
.open = fuse_dev_open, |
|
.llseek = no_llseek, |
|
.read_iter = fuse_dev_read, |
|
.splice_read = fuse_dev_splice_read, |
|
.write_iter = fuse_dev_write, |
|
.splice_write = fuse_dev_splice_write, |
|
.poll = fuse_dev_poll, |
|
.release = fuse_dev_release, |
|
.fasync = fuse_dev_fasync, |
|
.unlocked_ioctl = fuse_dev_ioctl, |
|
.compat_ioctl = compat_ptr_ioctl, |
|
}; |
|
EXPORT_SYMBOL_GPL(fuse_dev_operations); |
|
|
|
static struct miscdevice fuse_miscdevice = { |
|
.minor = FUSE_MINOR, |
|
.name = "fuse", |
|
.fops = &fuse_dev_operations, |
|
}; |
|
|
|
int __init fuse_dev_init(void) |
|
{ |
|
int err = -ENOMEM; |
|
fuse_req_cachep = kmem_cache_create("fuse_request", |
|
sizeof(struct fuse_req), |
|
0, 0, NULL); |
|
if (!fuse_req_cachep) |
|
goto out; |
|
|
|
err = misc_register(&fuse_miscdevice); |
|
if (err) |
|
goto out_cache_clean; |
|
|
|
return 0; |
|
|
|
out_cache_clean: |
|
kmem_cache_destroy(fuse_req_cachep); |
|
out: |
|
return err; |
|
} |
|
|
|
void fuse_dev_cleanup(void) |
|
{ |
|
misc_deregister(&fuse_miscdevice); |
|
kmem_cache_destroy(fuse_req_cachep); |
|
}
|
|
|