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1773 lines
47 KiB
1773 lines
47 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 1991, 1992 Linus Torvalds |
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* Copyright (C) 1994, Karl Keyte: Added support for disk statistics |
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* Elevator latency, (C) 2000 Andrea Arcangeli <[email protected]> SuSE |
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* Queue request tables / lock, selectable elevator, Jens Axboe <[email protected]> |
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* kernel-doc documentation started by NeilBrown <[email protected]> |
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* - July2000 |
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* bio rewrite, highmem i/o, etc, Jens Axboe <[email protected]> - may 2001 |
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*/ |
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|
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/* |
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* This handles all read/write requests to block devices |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/bio.h> |
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#include <linux/blkdev.h> |
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#include <linux/blk-mq.h> |
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#include <linux/blk-pm.h> |
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#include <linux/highmem.h> |
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#include <linux/mm.h> |
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#include <linux/pagemap.h> |
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#include <linux/kernel_stat.h> |
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#include <linux/string.h> |
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#include <linux/init.h> |
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#include <linux/completion.h> |
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#include <linux/slab.h> |
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#include <linux/swap.h> |
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#include <linux/writeback.h> |
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#include <linux/task_io_accounting_ops.h> |
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#include <linux/fault-inject.h> |
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#include <linux/list_sort.h> |
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#include <linux/delay.h> |
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#include <linux/ratelimit.h> |
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#include <linux/pm_runtime.h> |
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#include <linux/blk-cgroup.h> |
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#include <linux/t10-pi.h> |
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#include <linux/debugfs.h> |
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#include <linux/bpf.h> |
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#include <linux/psi.h> |
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#include <linux/sched/sysctl.h> |
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#include <linux/blk-crypto.h> |
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|
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#define CREATE_TRACE_POINTS |
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#include <trace/events/block.h> |
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|
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#include "blk.h" |
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#include "blk-mq.h" |
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#include "blk-mq-sched.h" |
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#include "blk-pm.h" |
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#include "blk-rq-qos.h" |
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|
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struct dentry *blk_debugfs_root; |
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|
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EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap); |
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EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap); |
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EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete); |
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EXPORT_TRACEPOINT_SYMBOL_GPL(block_split); |
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EXPORT_TRACEPOINT_SYMBOL_GPL(block_unplug); |
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EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_insert); |
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|
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DEFINE_IDA(blk_queue_ida); |
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|
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/* |
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* For queue allocation |
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*/ |
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struct kmem_cache *blk_requestq_cachep; |
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|
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/* |
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* Controlling structure to kblockd |
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*/ |
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static struct workqueue_struct *kblockd_workqueue; |
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|
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/** |
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* blk_queue_flag_set - atomically set a queue flag |
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* @flag: flag to be set |
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* @q: request queue |
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*/ |
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void blk_queue_flag_set(unsigned int flag, struct request_queue *q) |
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{ |
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set_bit(flag, &q->queue_flags); |
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} |
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EXPORT_SYMBOL(blk_queue_flag_set); |
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|
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/** |
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* blk_queue_flag_clear - atomically clear a queue flag |
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* @flag: flag to be cleared |
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* @q: request queue |
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*/ |
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void blk_queue_flag_clear(unsigned int flag, struct request_queue *q) |
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{ |
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clear_bit(flag, &q->queue_flags); |
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} |
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EXPORT_SYMBOL(blk_queue_flag_clear); |
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|
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/** |
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* blk_queue_flag_test_and_set - atomically test and set a queue flag |
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* @flag: flag to be set |
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* @q: request queue |
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* |
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* Returns the previous value of @flag - 0 if the flag was not set and 1 if |
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* the flag was already set. |
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*/ |
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bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q) |
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{ |
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return test_and_set_bit(flag, &q->queue_flags); |
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} |
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EXPORT_SYMBOL_GPL(blk_queue_flag_test_and_set); |
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|
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void blk_rq_init(struct request_queue *q, struct request *rq) |
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{ |
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memset(rq, 0, sizeof(*rq)); |
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|
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INIT_LIST_HEAD(&rq->queuelist); |
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rq->q = q; |
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rq->__sector = (sector_t) -1; |
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INIT_HLIST_NODE(&rq->hash); |
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RB_CLEAR_NODE(&rq->rb_node); |
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rq->tag = BLK_MQ_NO_TAG; |
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rq->internal_tag = BLK_MQ_NO_TAG; |
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rq->start_time_ns = ktime_get_ns(); |
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rq->part = NULL; |
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blk_crypto_rq_set_defaults(rq); |
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} |
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EXPORT_SYMBOL(blk_rq_init); |
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|
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#define REQ_OP_NAME(name) [REQ_OP_##name] = #name |
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static const char *const blk_op_name[] = { |
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REQ_OP_NAME(READ), |
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REQ_OP_NAME(WRITE), |
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REQ_OP_NAME(FLUSH), |
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REQ_OP_NAME(DISCARD), |
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REQ_OP_NAME(SECURE_ERASE), |
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REQ_OP_NAME(ZONE_RESET), |
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REQ_OP_NAME(ZONE_RESET_ALL), |
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REQ_OP_NAME(ZONE_OPEN), |
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REQ_OP_NAME(ZONE_CLOSE), |
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REQ_OP_NAME(ZONE_FINISH), |
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REQ_OP_NAME(ZONE_APPEND), |
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REQ_OP_NAME(WRITE_SAME), |
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REQ_OP_NAME(WRITE_ZEROES), |
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REQ_OP_NAME(DRV_IN), |
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REQ_OP_NAME(DRV_OUT), |
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}; |
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#undef REQ_OP_NAME |
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|
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/** |
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* blk_op_str - Return string XXX in the REQ_OP_XXX. |
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* @op: REQ_OP_XXX. |
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* |
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* Description: Centralize block layer function to convert REQ_OP_XXX into |
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* string format. Useful in the debugging and tracing bio or request. For |
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* invalid REQ_OP_XXX it returns string "UNKNOWN". |
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*/ |
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inline const char *blk_op_str(unsigned int op) |
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{ |
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const char *op_str = "UNKNOWN"; |
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|
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if (op < ARRAY_SIZE(blk_op_name) && blk_op_name[op]) |
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op_str = blk_op_name[op]; |
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return op_str; |
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} |
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EXPORT_SYMBOL_GPL(blk_op_str); |
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|
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static const struct { |
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int errno; |
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const char *name; |
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} blk_errors[] = { |
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[BLK_STS_OK] = { 0, "" }, |
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[BLK_STS_NOTSUPP] = { -EOPNOTSUPP, "operation not supported" }, |
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[BLK_STS_TIMEOUT] = { -ETIMEDOUT, "timeout" }, |
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[BLK_STS_NOSPC] = { -ENOSPC, "critical space allocation" }, |
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[BLK_STS_TRANSPORT] = { -ENOLINK, "recoverable transport" }, |
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[BLK_STS_TARGET] = { -EREMOTEIO, "critical target" }, |
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[BLK_STS_NEXUS] = { -EBADE, "critical nexus" }, |
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[BLK_STS_MEDIUM] = { -ENODATA, "critical medium" }, |
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[BLK_STS_PROTECTION] = { -EILSEQ, "protection" }, |
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[BLK_STS_RESOURCE] = { -ENOMEM, "kernel resource" }, |
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[BLK_STS_DEV_RESOURCE] = { -EBUSY, "device resource" }, |
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[BLK_STS_AGAIN] = { -EAGAIN, "nonblocking retry" }, |
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|
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/* device mapper special case, should not leak out: */ |
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[BLK_STS_DM_REQUEUE] = { -EREMCHG, "dm internal retry" }, |
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|
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/* zone device specific errors */ |
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[BLK_STS_ZONE_OPEN_RESOURCE] = { -ETOOMANYREFS, "open zones exceeded" }, |
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[BLK_STS_ZONE_ACTIVE_RESOURCE] = { -EOVERFLOW, "active zones exceeded" }, |
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|
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/* everything else not covered above: */ |
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[BLK_STS_IOERR] = { -EIO, "I/O" }, |
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}; |
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|
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blk_status_t errno_to_blk_status(int errno) |
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{ |
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int i; |
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|
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for (i = 0; i < ARRAY_SIZE(blk_errors); i++) { |
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if (blk_errors[i].errno == errno) |
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return (__force blk_status_t)i; |
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} |
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|
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return BLK_STS_IOERR; |
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} |
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EXPORT_SYMBOL_GPL(errno_to_blk_status); |
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|
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int blk_status_to_errno(blk_status_t status) |
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{ |
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int idx = (__force int)status; |
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|
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if (WARN_ON_ONCE(idx >= ARRAY_SIZE(blk_errors))) |
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return -EIO; |
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return blk_errors[idx].errno; |
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} |
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EXPORT_SYMBOL_GPL(blk_status_to_errno); |
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|
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static void print_req_error(struct request *req, blk_status_t status, |
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const char *caller) |
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{ |
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int idx = (__force int)status; |
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|
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if (WARN_ON_ONCE(idx >= ARRAY_SIZE(blk_errors))) |
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return; |
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|
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printk_ratelimited(KERN_ERR |
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"%s: %s error, dev %s, sector %llu op 0x%x:(%s) flags 0x%x " |
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"phys_seg %u prio class %u\n", |
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caller, blk_errors[idx].name, |
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req->rq_disk ? req->rq_disk->disk_name : "?", |
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blk_rq_pos(req), req_op(req), blk_op_str(req_op(req)), |
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req->cmd_flags & ~REQ_OP_MASK, |
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req->nr_phys_segments, |
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IOPRIO_PRIO_CLASS(req->ioprio)); |
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} |
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|
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static void req_bio_endio(struct request *rq, struct bio *bio, |
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unsigned int nbytes, blk_status_t error) |
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{ |
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if (error) |
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bio->bi_status = error; |
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|
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if (unlikely(rq->rq_flags & RQF_QUIET)) |
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bio_set_flag(bio, BIO_QUIET); |
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bio_advance(bio, nbytes); |
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if (req_op(rq) == REQ_OP_ZONE_APPEND && error == BLK_STS_OK) { |
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/* |
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* Partial zone append completions cannot be supported as the |
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* BIO fragments may end up not being written sequentially. |
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*/ |
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if (bio->bi_iter.bi_size) |
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bio->bi_status = BLK_STS_IOERR; |
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else |
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bio->bi_iter.bi_sector = rq->__sector; |
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} |
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|
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/* don't actually finish bio if it's part of flush sequence */ |
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if (bio->bi_iter.bi_size == 0 && !(rq->rq_flags & RQF_FLUSH_SEQ)) |
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bio_endio(bio); |
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} |
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|
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void blk_dump_rq_flags(struct request *rq, char *msg) |
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{ |
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printk(KERN_INFO "%s: dev %s: flags=%llx\n", msg, |
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rq->rq_disk ? rq->rq_disk->disk_name : "?", |
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(unsigned long long) rq->cmd_flags); |
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|
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printk(KERN_INFO " sector %llu, nr/cnr %u/%u\n", |
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(unsigned long long)blk_rq_pos(rq), |
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blk_rq_sectors(rq), blk_rq_cur_sectors(rq)); |
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printk(KERN_INFO " bio %p, biotail %p, len %u\n", |
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rq->bio, rq->biotail, blk_rq_bytes(rq)); |
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} |
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EXPORT_SYMBOL(blk_dump_rq_flags); |
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|
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/** |
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* blk_sync_queue - cancel any pending callbacks on a queue |
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* @q: the queue |
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* |
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* Description: |
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* The block layer may perform asynchronous callback activity |
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* on a queue, such as calling the unplug function after a timeout. |
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* A block device may call blk_sync_queue to ensure that any |
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* such activity is cancelled, thus allowing it to release resources |
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* that the callbacks might use. The caller must already have made sure |
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* that its ->submit_bio will not re-add plugging prior to calling |
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* this function. |
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* |
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* This function does not cancel any asynchronous activity arising |
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* out of elevator or throttling code. That would require elevator_exit() |
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* and blkcg_exit_queue() to be called with queue lock initialized. |
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* |
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*/ |
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void blk_sync_queue(struct request_queue *q) |
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{ |
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del_timer_sync(&q->timeout); |
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cancel_work_sync(&q->timeout_work); |
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} |
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EXPORT_SYMBOL(blk_sync_queue); |
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|
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/** |
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* blk_set_pm_only - increment pm_only counter |
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* @q: request queue pointer |
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*/ |
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void blk_set_pm_only(struct request_queue *q) |
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{ |
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atomic_inc(&q->pm_only); |
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} |
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EXPORT_SYMBOL_GPL(blk_set_pm_only); |
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|
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void blk_clear_pm_only(struct request_queue *q) |
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{ |
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int pm_only; |
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|
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pm_only = atomic_dec_return(&q->pm_only); |
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WARN_ON_ONCE(pm_only < 0); |
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if (pm_only == 0) |
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wake_up_all(&q->mq_freeze_wq); |
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} |
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EXPORT_SYMBOL_GPL(blk_clear_pm_only); |
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|
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/** |
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* blk_put_queue - decrement the request_queue refcount |
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* @q: the request_queue structure to decrement the refcount for |
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* |
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* Decrements the refcount of the request_queue kobject. When this reaches 0 |
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* we'll have blk_release_queue() called. |
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* |
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* Context: Any context, but the last reference must not be dropped from |
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* atomic context. |
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*/ |
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void blk_put_queue(struct request_queue *q) |
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{ |
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kobject_put(&q->kobj); |
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} |
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EXPORT_SYMBOL(blk_put_queue); |
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|
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void blk_set_queue_dying(struct request_queue *q) |
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{ |
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blk_queue_flag_set(QUEUE_FLAG_DYING, q); |
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|
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/* |
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* When queue DYING flag is set, we need to block new req |
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* entering queue, so we call blk_freeze_queue_start() to |
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* prevent I/O from crossing blk_queue_enter(). |
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*/ |
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blk_freeze_queue_start(q); |
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|
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if (queue_is_mq(q)) |
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blk_mq_wake_waiters(q); |
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|
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/* Make blk_queue_enter() reexamine the DYING flag. */ |
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wake_up_all(&q->mq_freeze_wq); |
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} |
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EXPORT_SYMBOL_GPL(blk_set_queue_dying); |
|
|
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/** |
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* blk_cleanup_queue - shutdown a request queue |
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* @q: request queue to shutdown |
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* |
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* Mark @q DYING, drain all pending requests, mark @q DEAD, destroy and |
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* put it. All future requests will be failed immediately with -ENODEV. |
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* |
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* Context: can sleep |
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*/ |
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void blk_cleanup_queue(struct request_queue *q) |
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{ |
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/* cannot be called from atomic context */ |
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might_sleep(); |
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|
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WARN_ON_ONCE(blk_queue_registered(q)); |
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|
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/* mark @q DYING, no new request or merges will be allowed afterwards */ |
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blk_set_queue_dying(q); |
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|
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blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q); |
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blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q); |
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|
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/* |
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* Drain all requests queued before DYING marking. Set DEAD flag to |
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* prevent that blk_mq_run_hw_queues() accesses the hardware queues |
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* after draining finished. |
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*/ |
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blk_freeze_queue(q); |
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|
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rq_qos_exit(q); |
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|
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blk_queue_flag_set(QUEUE_FLAG_DEAD, q); |
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|
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/* for synchronous bio-based driver finish in-flight integrity i/o */ |
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blk_flush_integrity(); |
|
|
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blk_sync_queue(q); |
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if (queue_is_mq(q)) |
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blk_mq_exit_queue(q); |
|
|
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/* |
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* In theory, request pool of sched_tags belongs to request queue. |
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* However, the current implementation requires tag_set for freeing |
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* requests, so free the pool now. |
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* |
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* Queue has become frozen, there can't be any in-queue requests, so |
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* it is safe to free requests now. |
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*/ |
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mutex_lock(&q->sysfs_lock); |
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if (q->elevator) |
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blk_mq_sched_free_requests(q); |
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mutex_unlock(&q->sysfs_lock); |
|
|
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percpu_ref_exit(&q->q_usage_counter); |
|
|
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/* @q is and will stay empty, shutdown and put */ |
|
blk_put_queue(q); |
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} |
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EXPORT_SYMBOL(blk_cleanup_queue); |
|
|
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/** |
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* blk_queue_enter() - try to increase q->q_usage_counter |
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* @q: request queue pointer |
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* @flags: BLK_MQ_REQ_NOWAIT and/or BLK_MQ_REQ_PM |
|
*/ |
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int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) |
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{ |
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const bool pm = flags & BLK_MQ_REQ_PM; |
|
|
|
while (true) { |
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bool success = false; |
|
|
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rcu_read_lock(); |
|
if (percpu_ref_tryget_live(&q->q_usage_counter)) { |
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/* |
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* The code that increments the pm_only counter is |
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* responsible for ensuring that that counter is |
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* globally visible before the queue is unfrozen. |
|
*/ |
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if ((pm && queue_rpm_status(q) != RPM_SUSPENDED) || |
|
!blk_queue_pm_only(q)) { |
|
success = true; |
|
} else { |
|
percpu_ref_put(&q->q_usage_counter); |
|
} |
|
} |
|
rcu_read_unlock(); |
|
|
|
if (success) |
|
return 0; |
|
|
|
if (flags & BLK_MQ_REQ_NOWAIT) |
|
return -EBUSY; |
|
|
|
/* |
|
* read pair of barrier in blk_freeze_queue_start(), |
|
* we need to order reading __PERCPU_REF_DEAD flag of |
|
* .q_usage_counter and reading .mq_freeze_depth or |
|
* queue dying flag, otherwise the following wait may |
|
* never return if the two reads are reordered. |
|
*/ |
|
smp_rmb(); |
|
|
|
wait_event(q->mq_freeze_wq, |
|
(!q->mq_freeze_depth && |
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blk_pm_resume_queue(pm, q)) || |
|
blk_queue_dying(q)); |
|
if (blk_queue_dying(q)) |
|
return -ENODEV; |
|
} |
|
} |
|
|
|
static inline int bio_queue_enter(struct bio *bio) |
|
{ |
|
struct request_queue *q = bio->bi_bdev->bd_disk->queue; |
|
bool nowait = bio->bi_opf & REQ_NOWAIT; |
|
int ret; |
|
|
|
ret = blk_queue_enter(q, nowait ? BLK_MQ_REQ_NOWAIT : 0); |
|
if (unlikely(ret)) { |
|
if (nowait && !blk_queue_dying(q)) |
|
bio_wouldblock_error(bio); |
|
else |
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bio_io_error(bio); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
void blk_queue_exit(struct request_queue *q) |
|
{ |
|
percpu_ref_put(&q->q_usage_counter); |
|
} |
|
|
|
static void blk_queue_usage_counter_release(struct percpu_ref *ref) |
|
{ |
|
struct request_queue *q = |
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container_of(ref, struct request_queue, q_usage_counter); |
|
|
|
wake_up_all(&q->mq_freeze_wq); |
|
} |
|
|
|
static void blk_rq_timed_out_timer(struct timer_list *t) |
|
{ |
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struct request_queue *q = from_timer(q, t, timeout); |
|
|
|
kblockd_schedule_work(&q->timeout_work); |
|
} |
|
|
|
static void blk_timeout_work(struct work_struct *work) |
|
{ |
|
} |
|
|
|
struct request_queue *blk_alloc_queue(int node_id) |
|
{ |
|
struct request_queue *q; |
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int ret; |
|
|
|
q = kmem_cache_alloc_node(blk_requestq_cachep, |
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GFP_KERNEL | __GFP_ZERO, node_id); |
|
if (!q) |
|
return NULL; |
|
|
|
q->last_merge = NULL; |
|
|
|
q->id = ida_simple_get(&blk_queue_ida, 0, 0, GFP_KERNEL); |
|
if (q->id < 0) |
|
goto fail_q; |
|
|
|
ret = bioset_init(&q->bio_split, BIO_POOL_SIZE, 0, 0); |
|
if (ret) |
|
goto fail_id; |
|
|
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q->stats = blk_alloc_queue_stats(); |
|
if (!q->stats) |
|
goto fail_split; |
|
|
|
q->node = node_id; |
|
|
|
atomic_set(&q->nr_active_requests_shared_sbitmap, 0); |
|
|
|
timer_setup(&q->timeout, blk_rq_timed_out_timer, 0); |
|
INIT_WORK(&q->timeout_work, blk_timeout_work); |
|
INIT_LIST_HEAD(&q->icq_list); |
|
#ifdef CONFIG_BLK_CGROUP |
|
INIT_LIST_HEAD(&q->blkg_list); |
|
#endif |
|
|
|
kobject_init(&q->kobj, &blk_queue_ktype); |
|
|
|
mutex_init(&q->debugfs_mutex); |
|
mutex_init(&q->sysfs_lock); |
|
mutex_init(&q->sysfs_dir_lock); |
|
spin_lock_init(&q->queue_lock); |
|
|
|
init_waitqueue_head(&q->mq_freeze_wq); |
|
mutex_init(&q->mq_freeze_lock); |
|
|
|
/* |
|
* Init percpu_ref in atomic mode so that it's faster to shutdown. |
|
* See blk_register_queue() for details. |
|
*/ |
|
if (percpu_ref_init(&q->q_usage_counter, |
|
blk_queue_usage_counter_release, |
|
PERCPU_REF_INIT_ATOMIC, GFP_KERNEL)) |
|
goto fail_stats; |
|
|
|
if (blkcg_init_queue(q)) |
|
goto fail_ref; |
|
|
|
blk_queue_dma_alignment(q, 511); |
|
blk_set_default_limits(&q->limits); |
|
q->nr_requests = BLKDEV_MAX_RQ; |
|
|
|
return q; |
|
|
|
fail_ref: |
|
percpu_ref_exit(&q->q_usage_counter); |
|
fail_stats: |
|
blk_free_queue_stats(q->stats); |
|
fail_split: |
|
bioset_exit(&q->bio_split); |
|
fail_id: |
|
ida_simple_remove(&blk_queue_ida, q->id); |
|
fail_q: |
|
kmem_cache_free(blk_requestq_cachep, q); |
|
return NULL; |
|
} |
|
|
|
/** |
|
* blk_get_queue - increment the request_queue refcount |
|
* @q: the request_queue structure to increment the refcount for |
|
* |
|
* Increment the refcount of the request_queue kobject. |
|
* |
|
* Context: Any context. |
|
*/ |
|
bool blk_get_queue(struct request_queue *q) |
|
{ |
|
if (likely(!blk_queue_dying(q))) { |
|
__blk_get_queue(q); |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
EXPORT_SYMBOL(blk_get_queue); |
|
|
|
/** |
|
* blk_get_request - allocate a request |
|
* @q: request queue to allocate a request for |
|
* @op: operation (REQ_OP_*) and REQ_* flags, e.g. REQ_SYNC. |
|
* @flags: BLK_MQ_REQ_* flags, e.g. BLK_MQ_REQ_NOWAIT. |
|
*/ |
|
struct request *blk_get_request(struct request_queue *q, unsigned int op, |
|
blk_mq_req_flags_t flags) |
|
{ |
|
struct request *req; |
|
|
|
WARN_ON_ONCE(op & REQ_NOWAIT); |
|
WARN_ON_ONCE(flags & ~(BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_PM)); |
|
|
|
req = blk_mq_alloc_request(q, op, flags); |
|
if (!IS_ERR(req) && q->mq_ops->initialize_rq_fn) |
|
q->mq_ops->initialize_rq_fn(req); |
|
|
|
return req; |
|
} |
|
EXPORT_SYMBOL(blk_get_request); |
|
|
|
void blk_put_request(struct request *req) |
|
{ |
|
blk_mq_free_request(req); |
|
} |
|
EXPORT_SYMBOL(blk_put_request); |
|
|
|
static void handle_bad_sector(struct bio *bio, sector_t maxsector) |
|
{ |
|
char b[BDEVNAME_SIZE]; |
|
|
|
pr_info_ratelimited("attempt to access beyond end of device\n" |
|
"%s: rw=%d, want=%llu, limit=%llu\n", |
|
bio_devname(bio, b), bio->bi_opf, |
|
bio_end_sector(bio), maxsector); |
|
} |
|
|
|
#ifdef CONFIG_FAIL_MAKE_REQUEST |
|
|
|
static DECLARE_FAULT_ATTR(fail_make_request); |
|
|
|
static int __init setup_fail_make_request(char *str) |
|
{ |
|
return setup_fault_attr(&fail_make_request, str); |
|
} |
|
__setup("fail_make_request=", setup_fail_make_request); |
|
|
|
static bool should_fail_request(struct block_device *part, unsigned int bytes) |
|
{ |
|
return part->bd_make_it_fail && should_fail(&fail_make_request, bytes); |
|
} |
|
|
|
static int __init fail_make_request_debugfs(void) |
|
{ |
|
struct dentry *dir = fault_create_debugfs_attr("fail_make_request", |
|
NULL, &fail_make_request); |
|
|
|
return PTR_ERR_OR_ZERO(dir); |
|
} |
|
|
|
late_initcall(fail_make_request_debugfs); |
|
|
|
#else /* CONFIG_FAIL_MAKE_REQUEST */ |
|
|
|
static inline bool should_fail_request(struct block_device *part, |
|
unsigned int bytes) |
|
{ |
|
return false; |
|
} |
|
|
|
#endif /* CONFIG_FAIL_MAKE_REQUEST */ |
|
|
|
static inline bool bio_check_ro(struct bio *bio) |
|
{ |
|
if (op_is_write(bio_op(bio)) && bdev_read_only(bio->bi_bdev)) { |
|
char b[BDEVNAME_SIZE]; |
|
|
|
if (op_is_flush(bio->bi_opf) && !bio_sectors(bio)) |
|
return false; |
|
|
|
WARN_ONCE(1, |
|
"Trying to write to read-only block-device %s (partno %d)\n", |
|
bio_devname(bio, b), bio->bi_bdev->bd_partno); |
|
/* Older lvm-tools actually trigger this */ |
|
return false; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
static noinline int should_fail_bio(struct bio *bio) |
|
{ |
|
if (should_fail_request(bdev_whole(bio->bi_bdev), bio->bi_iter.bi_size)) |
|
return -EIO; |
|
return 0; |
|
} |
|
ALLOW_ERROR_INJECTION(should_fail_bio, ERRNO); |
|
|
|
/* |
|
* Check whether this bio extends beyond the end of the device or partition. |
|
* This may well happen - the kernel calls bread() without checking the size of |
|
* the device, e.g., when mounting a file system. |
|
*/ |
|
static inline int bio_check_eod(struct bio *bio) |
|
{ |
|
sector_t maxsector = bdev_nr_sectors(bio->bi_bdev); |
|
unsigned int nr_sectors = bio_sectors(bio); |
|
|
|
if (nr_sectors && maxsector && |
|
(nr_sectors > maxsector || |
|
bio->bi_iter.bi_sector > maxsector - nr_sectors)) { |
|
handle_bad_sector(bio, maxsector); |
|
return -EIO; |
|
} |
|
return 0; |
|
} |
|
|
|
/* |
|
* Remap block n of partition p to block n+start(p) of the disk. |
|
*/ |
|
static int blk_partition_remap(struct bio *bio) |
|
{ |
|
struct block_device *p = bio->bi_bdev; |
|
|
|
if (unlikely(should_fail_request(p, bio->bi_iter.bi_size))) |
|
return -EIO; |
|
if (bio_sectors(bio)) { |
|
bio->bi_iter.bi_sector += p->bd_start_sect; |
|
trace_block_bio_remap(bio, p->bd_dev, |
|
bio->bi_iter.bi_sector - |
|
p->bd_start_sect); |
|
} |
|
bio_set_flag(bio, BIO_REMAPPED); |
|
return 0; |
|
} |
|
|
|
/* |
|
* Check write append to a zoned block device. |
|
*/ |
|
static inline blk_status_t blk_check_zone_append(struct request_queue *q, |
|
struct bio *bio) |
|
{ |
|
sector_t pos = bio->bi_iter.bi_sector; |
|
int nr_sectors = bio_sectors(bio); |
|
|
|
/* Only applicable to zoned block devices */ |
|
if (!blk_queue_is_zoned(q)) |
|
return BLK_STS_NOTSUPP; |
|
|
|
/* The bio sector must point to the start of a sequential zone */ |
|
if (pos & (blk_queue_zone_sectors(q) - 1) || |
|
!blk_queue_zone_is_seq(q, pos)) |
|
return BLK_STS_IOERR; |
|
|
|
/* |
|
* Not allowed to cross zone boundaries. Otherwise, the BIO will be |
|
* split and could result in non-contiguous sectors being written in |
|
* different zones. |
|
*/ |
|
if (nr_sectors > q->limits.chunk_sectors) |
|
return BLK_STS_IOERR; |
|
|
|
/* Make sure the BIO is small enough and will not get split */ |
|
if (nr_sectors > q->limits.max_zone_append_sectors) |
|
return BLK_STS_IOERR; |
|
|
|
bio->bi_opf |= REQ_NOMERGE; |
|
|
|
return BLK_STS_OK; |
|
} |
|
|
|
static noinline_for_stack bool submit_bio_checks(struct bio *bio) |
|
{ |
|
struct block_device *bdev = bio->bi_bdev; |
|
struct request_queue *q = bdev->bd_disk->queue; |
|
blk_status_t status = BLK_STS_IOERR; |
|
struct blk_plug *plug; |
|
|
|
might_sleep(); |
|
|
|
plug = blk_mq_plug(q, bio); |
|
if (plug && plug->nowait) |
|
bio->bi_opf |= REQ_NOWAIT; |
|
|
|
/* |
|
* For a REQ_NOWAIT based request, return -EOPNOTSUPP |
|
* if queue does not support NOWAIT. |
|
*/ |
|
if ((bio->bi_opf & REQ_NOWAIT) && !blk_queue_nowait(q)) |
|
goto not_supported; |
|
|
|
if (should_fail_bio(bio)) |
|
goto end_io; |
|
if (unlikely(bio_check_ro(bio))) |
|
goto end_io; |
|
if (!bio_flagged(bio, BIO_REMAPPED)) { |
|
if (unlikely(bio_check_eod(bio))) |
|
goto end_io; |
|
if (bdev->bd_partno && unlikely(blk_partition_remap(bio))) |
|
goto end_io; |
|
} |
|
|
|
/* |
|
* Filter flush bio's early so that bio based drivers without flush |
|
* support don't have to worry about them. |
|
*/ |
|
if (op_is_flush(bio->bi_opf) && |
|
!test_bit(QUEUE_FLAG_WC, &q->queue_flags)) { |
|
bio->bi_opf &= ~(REQ_PREFLUSH | REQ_FUA); |
|
if (!bio_sectors(bio)) { |
|
status = BLK_STS_OK; |
|
goto end_io; |
|
} |
|
} |
|
|
|
if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) |
|
bio_clear_hipri(bio); |
|
|
|
switch (bio_op(bio)) { |
|
case REQ_OP_DISCARD: |
|
if (!blk_queue_discard(q)) |
|
goto not_supported; |
|
break; |
|
case REQ_OP_SECURE_ERASE: |
|
if (!blk_queue_secure_erase(q)) |
|
goto not_supported; |
|
break; |
|
case REQ_OP_WRITE_SAME: |
|
if (!q->limits.max_write_same_sectors) |
|
goto not_supported; |
|
break; |
|
case REQ_OP_ZONE_APPEND: |
|
status = blk_check_zone_append(q, bio); |
|
if (status != BLK_STS_OK) |
|
goto end_io; |
|
break; |
|
case REQ_OP_ZONE_RESET: |
|
case REQ_OP_ZONE_OPEN: |
|
case REQ_OP_ZONE_CLOSE: |
|
case REQ_OP_ZONE_FINISH: |
|
if (!blk_queue_is_zoned(q)) |
|
goto not_supported; |
|
break; |
|
case REQ_OP_ZONE_RESET_ALL: |
|
if (!blk_queue_is_zoned(q) || !blk_queue_zone_resetall(q)) |
|
goto not_supported; |
|
break; |
|
case REQ_OP_WRITE_ZEROES: |
|
if (!q->limits.max_write_zeroes_sectors) |
|
goto not_supported; |
|
break; |
|
default: |
|
break; |
|
} |
|
|
|
/* |
|
* Various block parts want %current->io_context, so allocate it up |
|
* front rather than dealing with lots of pain to allocate it only |
|
* where needed. This may fail and the block layer knows how to live |
|
* with it. |
|
*/ |
|
if (unlikely(!current->io_context)) |
|
create_task_io_context(current, GFP_ATOMIC, q->node); |
|
|
|
if (blk_throtl_bio(bio)) { |
|
blkcg_bio_issue_init(bio); |
|
return false; |
|
} |
|
|
|
blk_cgroup_bio_start(bio); |
|
blkcg_bio_issue_init(bio); |
|
|
|
if (!bio_flagged(bio, BIO_TRACE_COMPLETION)) { |
|
trace_block_bio_queue(bio); |
|
/* Now that enqueuing has been traced, we need to trace |
|
* completion as well. |
|
*/ |
|
bio_set_flag(bio, BIO_TRACE_COMPLETION); |
|
} |
|
return true; |
|
|
|
not_supported: |
|
status = BLK_STS_NOTSUPP; |
|
end_io: |
|
bio->bi_status = status; |
|
bio_endio(bio); |
|
return false; |
|
} |
|
|
|
static blk_qc_t __submit_bio(struct bio *bio) |
|
{ |
|
struct gendisk *disk = bio->bi_bdev->bd_disk; |
|
blk_qc_t ret = BLK_QC_T_NONE; |
|
|
|
if (blk_crypto_bio_prep(&bio)) { |
|
if (!disk->fops->submit_bio) |
|
return blk_mq_submit_bio(bio); |
|
ret = disk->fops->submit_bio(bio); |
|
} |
|
blk_queue_exit(disk->queue); |
|
return ret; |
|
} |
|
|
|
/* |
|
* The loop in this function may be a bit non-obvious, and so deserves some |
|
* explanation: |
|
* |
|
* - Before entering the loop, bio->bi_next is NULL (as all callers ensure |
|
* that), so we have a list with a single bio. |
|
* - We pretend that we have just taken it off a longer list, so we assign |
|
* bio_list to a pointer to the bio_list_on_stack, thus initialising the |
|
* bio_list of new bios to be added. ->submit_bio() may indeed add some more |
|
* bios through a recursive call to submit_bio_noacct. If it did, we find a |
|
* non-NULL value in bio_list and re-enter the loop from the top. |
|
* - In this case we really did just take the bio of the top of the list (no |
|
* pretending) and so remove it from bio_list, and call into ->submit_bio() |
|
* again. |
|
* |
|
* bio_list_on_stack[0] contains bios submitted by the current ->submit_bio. |
|
* bio_list_on_stack[1] contains bios that were submitted before the current |
|
* ->submit_bio_bio, but that haven't been processed yet. |
|
*/ |
|
static blk_qc_t __submit_bio_noacct(struct bio *bio) |
|
{ |
|
struct bio_list bio_list_on_stack[2]; |
|
blk_qc_t ret = BLK_QC_T_NONE; |
|
|
|
BUG_ON(bio->bi_next); |
|
|
|
bio_list_init(&bio_list_on_stack[0]); |
|
current->bio_list = bio_list_on_stack; |
|
|
|
do { |
|
struct request_queue *q = bio->bi_bdev->bd_disk->queue; |
|
struct bio_list lower, same; |
|
|
|
if (unlikely(bio_queue_enter(bio) != 0)) |
|
continue; |
|
|
|
/* |
|
* Create a fresh bio_list for all subordinate requests. |
|
*/ |
|
bio_list_on_stack[1] = bio_list_on_stack[0]; |
|
bio_list_init(&bio_list_on_stack[0]); |
|
|
|
ret = __submit_bio(bio); |
|
|
|
/* |
|
* Sort new bios into those for a lower level and those for the |
|
* same level. |
|
*/ |
|
bio_list_init(&lower); |
|
bio_list_init(&same); |
|
while ((bio = bio_list_pop(&bio_list_on_stack[0])) != NULL) |
|
if (q == bio->bi_bdev->bd_disk->queue) |
|
bio_list_add(&same, bio); |
|
else |
|
bio_list_add(&lower, bio); |
|
|
|
/* |
|
* Now assemble so we handle the lowest level first. |
|
*/ |
|
bio_list_merge(&bio_list_on_stack[0], &lower); |
|
bio_list_merge(&bio_list_on_stack[0], &same); |
|
bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]); |
|
} while ((bio = bio_list_pop(&bio_list_on_stack[0]))); |
|
|
|
current->bio_list = NULL; |
|
return ret; |
|
} |
|
|
|
static blk_qc_t __submit_bio_noacct_mq(struct bio *bio) |
|
{ |
|
struct bio_list bio_list[2] = { }; |
|
blk_qc_t ret = BLK_QC_T_NONE; |
|
|
|
current->bio_list = bio_list; |
|
|
|
do { |
|
struct gendisk *disk = bio->bi_bdev->bd_disk; |
|
|
|
if (unlikely(bio_queue_enter(bio) != 0)) |
|
continue; |
|
|
|
if (!blk_crypto_bio_prep(&bio)) { |
|
blk_queue_exit(disk->queue); |
|
ret = BLK_QC_T_NONE; |
|
continue; |
|
} |
|
|
|
ret = blk_mq_submit_bio(bio); |
|
} while ((bio = bio_list_pop(&bio_list[0]))); |
|
|
|
current->bio_list = NULL; |
|
return ret; |
|
} |
|
|
|
/** |
|
* submit_bio_noacct - re-submit a bio to the block device layer for I/O |
|
* @bio: The bio describing the location in memory and on the device. |
|
* |
|
* This is a version of submit_bio() that shall only be used for I/O that is |
|
* resubmitted to lower level drivers by stacking block drivers. All file |
|
* systems and other upper level users of the block layer should use |
|
* submit_bio() instead. |
|
*/ |
|
blk_qc_t submit_bio_noacct(struct bio *bio) |
|
{ |
|
if (!submit_bio_checks(bio)) |
|
return BLK_QC_T_NONE; |
|
|
|
/* |
|
* We only want one ->submit_bio to be active at a time, else stack |
|
* usage with stacked devices could be a problem. Use current->bio_list |
|
* to collect a list of requests submited by a ->submit_bio method while |
|
* it is active, and then process them after it returned. |
|
*/ |
|
if (current->bio_list) { |
|
bio_list_add(¤t->bio_list[0], bio); |
|
return BLK_QC_T_NONE; |
|
} |
|
|
|
if (!bio->bi_bdev->bd_disk->fops->submit_bio) |
|
return __submit_bio_noacct_mq(bio); |
|
return __submit_bio_noacct(bio); |
|
} |
|
EXPORT_SYMBOL(submit_bio_noacct); |
|
|
|
/** |
|
* submit_bio - submit a bio to the block device layer for I/O |
|
* @bio: The &struct bio which describes the I/O |
|
* |
|
* submit_bio() is used to submit I/O requests to block devices. It is passed a |
|
* fully set up &struct bio that describes the I/O that needs to be done. The |
|
* bio will be send to the device described by the bi_bdev field. |
|
* |
|
* The success/failure status of the request, along with notification of |
|
* completion, is delivered asynchronously through the ->bi_end_io() callback |
|
* in @bio. The bio must NOT be touched by thecaller until ->bi_end_io() has |
|
* been called. |
|
*/ |
|
blk_qc_t submit_bio(struct bio *bio) |
|
{ |
|
if (blkcg_punt_bio_submit(bio)) |
|
return BLK_QC_T_NONE; |
|
|
|
/* |
|
* If it's a regular read/write or a barrier with data attached, |
|
* go through the normal accounting stuff before submission. |
|
*/ |
|
if (bio_has_data(bio)) { |
|
unsigned int count; |
|
|
|
if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME)) |
|
count = queue_logical_block_size( |
|
bio->bi_bdev->bd_disk->queue) >> 9; |
|
else |
|
count = bio_sectors(bio); |
|
|
|
if (op_is_write(bio_op(bio))) { |
|
count_vm_events(PGPGOUT, count); |
|
} else { |
|
task_io_account_read(bio->bi_iter.bi_size); |
|
count_vm_events(PGPGIN, count); |
|
} |
|
} |
|
|
|
/* |
|
* If we're reading data that is part of the userspace workingset, count |
|
* submission time as memory stall. When the device is congested, or |
|
* the submitting cgroup IO-throttled, submission can be a significant |
|
* part of overall IO time. |
|
*/ |
|
if (unlikely(bio_op(bio) == REQ_OP_READ && |
|
bio_flagged(bio, BIO_WORKINGSET))) { |
|
unsigned long pflags; |
|
blk_qc_t ret; |
|
|
|
psi_memstall_enter(&pflags); |
|
ret = submit_bio_noacct(bio); |
|
psi_memstall_leave(&pflags); |
|
|
|
return ret; |
|
} |
|
|
|
return submit_bio_noacct(bio); |
|
} |
|
EXPORT_SYMBOL(submit_bio); |
|
|
|
/** |
|
* blk_cloned_rq_check_limits - Helper function to check a cloned request |
|
* for the new queue limits |
|
* @q: the queue |
|
* @rq: the request being checked |
|
* |
|
* Description: |
|
* @rq may have been made based on weaker limitations of upper-level queues |
|
* in request stacking drivers, and it may violate the limitation of @q. |
|
* Since the block layer and the underlying device driver trust @rq |
|
* after it is inserted to @q, it should be checked against @q before |
|
* the insertion using this generic function. |
|
* |
|
* Request stacking drivers like request-based dm may change the queue |
|
* limits when retrying requests on other queues. Those requests need |
|
* to be checked against the new queue limits again during dispatch. |
|
*/ |
|
static blk_status_t blk_cloned_rq_check_limits(struct request_queue *q, |
|
struct request *rq) |
|
{ |
|
unsigned int max_sectors = blk_queue_get_max_sectors(q, req_op(rq)); |
|
|
|
if (blk_rq_sectors(rq) > max_sectors) { |
|
/* |
|
* SCSI device does not have a good way to return if |
|
* Write Same/Zero is actually supported. If a device rejects |
|
* a non-read/write command (discard, write same,etc.) the |
|
* low-level device driver will set the relevant queue limit to |
|
* 0 to prevent blk-lib from issuing more of the offending |
|
* operations. Commands queued prior to the queue limit being |
|
* reset need to be completed with BLK_STS_NOTSUPP to avoid I/O |
|
* errors being propagated to upper layers. |
|
*/ |
|
if (max_sectors == 0) |
|
return BLK_STS_NOTSUPP; |
|
|
|
printk(KERN_ERR "%s: over max size limit. (%u > %u)\n", |
|
__func__, blk_rq_sectors(rq), max_sectors); |
|
return BLK_STS_IOERR; |
|
} |
|
|
|
/* |
|
* The queue settings related to segment counting may differ from the |
|
* original queue. |
|
*/ |
|
rq->nr_phys_segments = blk_recalc_rq_segments(rq); |
|
if (rq->nr_phys_segments > queue_max_segments(q)) { |
|
printk(KERN_ERR "%s: over max segments limit. (%hu > %hu)\n", |
|
__func__, rq->nr_phys_segments, queue_max_segments(q)); |
|
return BLK_STS_IOERR; |
|
} |
|
|
|
return BLK_STS_OK; |
|
} |
|
|
|
/** |
|
* blk_insert_cloned_request - Helper for stacking drivers to submit a request |
|
* @q: the queue to submit the request |
|
* @rq: the request being queued |
|
*/ |
|
blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *rq) |
|
{ |
|
blk_status_t ret; |
|
|
|
ret = blk_cloned_rq_check_limits(q, rq); |
|
if (ret != BLK_STS_OK) |
|
return ret; |
|
|
|
if (rq->rq_disk && |
|
should_fail_request(rq->rq_disk->part0, blk_rq_bytes(rq))) |
|
return BLK_STS_IOERR; |
|
|
|
if (blk_crypto_insert_cloned_request(rq)) |
|
return BLK_STS_IOERR; |
|
|
|
if (blk_queue_io_stat(q)) |
|
blk_account_io_start(rq); |
|
|
|
/* |
|
* Since we have a scheduler attached on the top device, |
|
* bypass a potential scheduler on the bottom device for |
|
* insert. |
|
*/ |
|
return blk_mq_request_issue_directly(rq, true); |
|
} |
|
EXPORT_SYMBOL_GPL(blk_insert_cloned_request); |
|
|
|
/** |
|
* blk_rq_err_bytes - determine number of bytes till the next failure boundary |
|
* @rq: request to examine |
|
* |
|
* Description: |
|
* A request could be merge of IOs which require different failure |
|
* handling. This function determines the number of bytes which |
|
* can be failed from the beginning of the request without |
|
* crossing into area which need to be retried further. |
|
* |
|
* Return: |
|
* The number of bytes to fail. |
|
*/ |
|
unsigned int blk_rq_err_bytes(const struct request *rq) |
|
{ |
|
unsigned int ff = rq->cmd_flags & REQ_FAILFAST_MASK; |
|
unsigned int bytes = 0; |
|
struct bio *bio; |
|
|
|
if (!(rq->rq_flags & RQF_MIXED_MERGE)) |
|
return blk_rq_bytes(rq); |
|
|
|
/* |
|
* Currently the only 'mixing' which can happen is between |
|
* different fastfail types. We can safely fail portions |
|
* which have all the failfast bits that the first one has - |
|
* the ones which are at least as eager to fail as the first |
|
* one. |
|
*/ |
|
for (bio = rq->bio; bio; bio = bio->bi_next) { |
|
if ((bio->bi_opf & ff) != ff) |
|
break; |
|
bytes += bio->bi_iter.bi_size; |
|
} |
|
|
|
/* this could lead to infinite loop */ |
|
BUG_ON(blk_rq_bytes(rq) && !bytes); |
|
return bytes; |
|
} |
|
EXPORT_SYMBOL_GPL(blk_rq_err_bytes); |
|
|
|
static void update_io_ticks(struct block_device *part, unsigned long now, |
|
bool end) |
|
{ |
|
unsigned long stamp; |
|
again: |
|
stamp = READ_ONCE(part->bd_stamp); |
|
if (unlikely(time_after(now, stamp))) { |
|
if (likely(cmpxchg(&part->bd_stamp, stamp, now) == stamp)) |
|
__part_stat_add(part, io_ticks, end ? now - stamp : 1); |
|
} |
|
if (part->bd_partno) { |
|
part = bdev_whole(part); |
|
goto again; |
|
} |
|
} |
|
|
|
static void blk_account_io_completion(struct request *req, unsigned int bytes) |
|
{ |
|
if (req->part && blk_do_io_stat(req)) { |
|
const int sgrp = op_stat_group(req_op(req)); |
|
|
|
part_stat_lock(); |
|
part_stat_add(req->part, sectors[sgrp], bytes >> 9); |
|
part_stat_unlock(); |
|
} |
|
} |
|
|
|
void blk_account_io_done(struct request *req, u64 now) |
|
{ |
|
/* |
|
* Account IO completion. flush_rq isn't accounted as a |
|
* normal IO on queueing nor completion. Accounting the |
|
* containing request is enough. |
|
*/ |
|
if (req->part && blk_do_io_stat(req) && |
|
!(req->rq_flags & RQF_FLUSH_SEQ)) { |
|
const int sgrp = op_stat_group(req_op(req)); |
|
|
|
part_stat_lock(); |
|
update_io_ticks(req->part, jiffies, true); |
|
part_stat_inc(req->part, ios[sgrp]); |
|
part_stat_add(req->part, nsecs[sgrp], now - req->start_time_ns); |
|
part_stat_unlock(); |
|
} |
|
} |
|
|
|
void blk_account_io_start(struct request *rq) |
|
{ |
|
if (!blk_do_io_stat(rq)) |
|
return; |
|
|
|
/* passthrough requests can hold bios that do not have ->bi_bdev set */ |
|
if (rq->bio && rq->bio->bi_bdev) |
|
rq->part = rq->bio->bi_bdev; |
|
else |
|
rq->part = rq->rq_disk->part0; |
|
|
|
part_stat_lock(); |
|
update_io_ticks(rq->part, jiffies, false); |
|
part_stat_unlock(); |
|
} |
|
|
|
static unsigned long __part_start_io_acct(struct block_device *part, |
|
unsigned int sectors, unsigned int op) |
|
{ |
|
const int sgrp = op_stat_group(op); |
|
unsigned long now = READ_ONCE(jiffies); |
|
|
|
part_stat_lock(); |
|
update_io_ticks(part, now, false); |
|
part_stat_inc(part, ios[sgrp]); |
|
part_stat_add(part, sectors[sgrp], sectors); |
|
part_stat_local_inc(part, in_flight[op_is_write(op)]); |
|
part_stat_unlock(); |
|
|
|
return now; |
|
} |
|
|
|
/** |
|
* bio_start_io_acct - start I/O accounting for bio based drivers |
|
* @bio: bio to start account for |
|
* |
|
* Returns the start time that should be passed back to bio_end_io_acct(). |
|
*/ |
|
unsigned long bio_start_io_acct(struct bio *bio) |
|
{ |
|
return __part_start_io_acct(bio->bi_bdev, bio_sectors(bio), bio_op(bio)); |
|
} |
|
EXPORT_SYMBOL_GPL(bio_start_io_acct); |
|
|
|
unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors, |
|
unsigned int op) |
|
{ |
|
return __part_start_io_acct(disk->part0, sectors, op); |
|
} |
|
EXPORT_SYMBOL(disk_start_io_acct); |
|
|
|
static void __part_end_io_acct(struct block_device *part, unsigned int op, |
|
unsigned long start_time) |
|
{ |
|
const int sgrp = op_stat_group(op); |
|
unsigned long now = READ_ONCE(jiffies); |
|
unsigned long duration = now - start_time; |
|
|
|
part_stat_lock(); |
|
update_io_ticks(part, now, true); |
|
part_stat_add(part, nsecs[sgrp], jiffies_to_nsecs(duration)); |
|
part_stat_local_dec(part, in_flight[op_is_write(op)]); |
|
part_stat_unlock(); |
|
} |
|
|
|
void bio_end_io_acct_remapped(struct bio *bio, unsigned long start_time, |
|
struct block_device *orig_bdev) |
|
{ |
|
__part_end_io_acct(orig_bdev, bio_op(bio), start_time); |
|
} |
|
EXPORT_SYMBOL_GPL(bio_end_io_acct_remapped); |
|
|
|
void disk_end_io_acct(struct gendisk *disk, unsigned int op, |
|
unsigned long start_time) |
|
{ |
|
__part_end_io_acct(disk->part0, op, start_time); |
|
} |
|
EXPORT_SYMBOL(disk_end_io_acct); |
|
|
|
/* |
|
* Steal bios from a request and add them to a bio list. |
|
* The request must not have been partially completed before. |
|
*/ |
|
void blk_steal_bios(struct bio_list *list, struct request *rq) |
|
{ |
|
if (rq->bio) { |
|
if (list->tail) |
|
list->tail->bi_next = rq->bio; |
|
else |
|
list->head = rq->bio; |
|
list->tail = rq->biotail; |
|
|
|
rq->bio = NULL; |
|
rq->biotail = NULL; |
|
} |
|
|
|
rq->__data_len = 0; |
|
} |
|
EXPORT_SYMBOL_GPL(blk_steal_bios); |
|
|
|
/** |
|
* blk_update_request - Complete multiple bytes without completing the request |
|
* @req: the request being processed |
|
* @error: block status code |
|
* @nr_bytes: number of bytes to complete for @req |
|
* |
|
* Description: |
|
* Ends I/O on a number of bytes attached to @req, but doesn't complete |
|
* the request structure even if @req doesn't have leftover. |
|
* If @req has leftover, sets it up for the next range of segments. |
|
* |
|
* Passing the result of blk_rq_bytes() as @nr_bytes guarantees |
|
* %false return from this function. |
|
* |
|
* Note: |
|
* The RQF_SPECIAL_PAYLOAD flag is ignored on purpose in this function |
|
* except in the consistency check at the end of this function. |
|
* |
|
* Return: |
|
* %false - this request doesn't have any more data |
|
* %true - this request has more data |
|
**/ |
|
bool blk_update_request(struct request *req, blk_status_t error, |
|
unsigned int nr_bytes) |
|
{ |
|
int total_bytes; |
|
|
|
trace_block_rq_complete(req, blk_status_to_errno(error), nr_bytes); |
|
|
|
if (!req->bio) |
|
return false; |
|
|
|
#ifdef CONFIG_BLK_DEV_INTEGRITY |
|
if (blk_integrity_rq(req) && req_op(req) == REQ_OP_READ && |
|
error == BLK_STS_OK) |
|
req->q->integrity.profile->complete_fn(req, nr_bytes); |
|
#endif |
|
|
|
if (unlikely(error && !blk_rq_is_passthrough(req) && |
|
!(req->rq_flags & RQF_QUIET))) |
|
print_req_error(req, error, __func__); |
|
|
|
blk_account_io_completion(req, nr_bytes); |
|
|
|
total_bytes = 0; |
|
while (req->bio) { |
|
struct bio *bio = req->bio; |
|
unsigned bio_bytes = min(bio->bi_iter.bi_size, nr_bytes); |
|
|
|
if (bio_bytes == bio->bi_iter.bi_size) |
|
req->bio = bio->bi_next; |
|
|
|
/* Completion has already been traced */ |
|
bio_clear_flag(bio, BIO_TRACE_COMPLETION); |
|
req_bio_endio(req, bio, bio_bytes, error); |
|
|
|
total_bytes += bio_bytes; |
|
nr_bytes -= bio_bytes; |
|
|
|
if (!nr_bytes) |
|
break; |
|
} |
|
|
|
/* |
|
* completely done |
|
*/ |
|
if (!req->bio) { |
|
/* |
|
* Reset counters so that the request stacking driver |
|
* can find how many bytes remain in the request |
|
* later. |
|
*/ |
|
req->__data_len = 0; |
|
return false; |
|
} |
|
|
|
req->__data_len -= total_bytes; |
|
|
|
/* update sector only for requests with clear definition of sector */ |
|
if (!blk_rq_is_passthrough(req)) |
|
req->__sector += total_bytes >> 9; |
|
|
|
/* mixed attributes always follow the first bio */ |
|
if (req->rq_flags & RQF_MIXED_MERGE) { |
|
req->cmd_flags &= ~REQ_FAILFAST_MASK; |
|
req->cmd_flags |= req->bio->bi_opf & REQ_FAILFAST_MASK; |
|
} |
|
|
|
if (!(req->rq_flags & RQF_SPECIAL_PAYLOAD)) { |
|
/* |
|
* If total number of sectors is less than the first segment |
|
* size, something has gone terribly wrong. |
|
*/ |
|
if (blk_rq_bytes(req) < blk_rq_cur_bytes(req)) { |
|
blk_dump_rq_flags(req, "request botched"); |
|
req->__data_len = blk_rq_cur_bytes(req); |
|
} |
|
|
|
/* recalculate the number of segments */ |
|
req->nr_phys_segments = blk_recalc_rq_segments(req); |
|
} |
|
|
|
return true; |
|
} |
|
EXPORT_SYMBOL_GPL(blk_update_request); |
|
|
|
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE |
|
/** |
|
* rq_flush_dcache_pages - Helper function to flush all pages in a request |
|
* @rq: the request to be flushed |
|
* |
|
* Description: |
|
* Flush all pages in @rq. |
|
*/ |
|
void rq_flush_dcache_pages(struct request *rq) |
|
{ |
|
struct req_iterator iter; |
|
struct bio_vec bvec; |
|
|
|
rq_for_each_segment(bvec, rq, iter) |
|
flush_dcache_page(bvec.bv_page); |
|
} |
|
EXPORT_SYMBOL_GPL(rq_flush_dcache_pages); |
|
#endif |
|
|
|
/** |
|
* blk_lld_busy - Check if underlying low-level drivers of a device are busy |
|
* @q : the queue of the device being checked |
|
* |
|
* Description: |
|
* Check if underlying low-level drivers of a device are busy. |
|
* If the drivers want to export their busy state, they must set own |
|
* exporting function using blk_queue_lld_busy() first. |
|
* |
|
* Basically, this function is used only by request stacking drivers |
|
* to stop dispatching requests to underlying devices when underlying |
|
* devices are busy. This behavior helps more I/O merging on the queue |
|
* of the request stacking driver and prevents I/O throughput regression |
|
* on burst I/O load. |
|
* |
|
* Return: |
|
* 0 - Not busy (The request stacking driver should dispatch request) |
|
* 1 - Busy (The request stacking driver should stop dispatching request) |
|
*/ |
|
int blk_lld_busy(struct request_queue *q) |
|
{ |
|
if (queue_is_mq(q) && q->mq_ops->busy) |
|
return q->mq_ops->busy(q); |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(blk_lld_busy); |
|
|
|
/** |
|
* blk_rq_unprep_clone - Helper function to free all bios in a cloned request |
|
* @rq: the clone request to be cleaned up |
|
* |
|
* Description: |
|
* Free all bios in @rq for a cloned request. |
|
*/ |
|
void blk_rq_unprep_clone(struct request *rq) |
|
{ |
|
struct bio *bio; |
|
|
|
while ((bio = rq->bio) != NULL) { |
|
rq->bio = bio->bi_next; |
|
|
|
bio_put(bio); |
|
} |
|
} |
|
EXPORT_SYMBOL_GPL(blk_rq_unprep_clone); |
|
|
|
/** |
|
* blk_rq_prep_clone - Helper function to setup clone request |
|
* @rq: the request to be setup |
|
* @rq_src: original request to be cloned |
|
* @bs: bio_set that bios for clone are allocated from |
|
* @gfp_mask: memory allocation mask for bio |
|
* @bio_ctr: setup function to be called for each clone bio. |
|
* Returns %0 for success, non %0 for failure. |
|
* @data: private data to be passed to @bio_ctr |
|
* |
|
* Description: |
|
* Clones bios in @rq_src to @rq, and copies attributes of @rq_src to @rq. |
|
* Also, pages which the original bios are pointing to are not copied |
|
* and the cloned bios just point same pages. |
|
* So cloned bios must be completed before original bios, which means |
|
* the caller must complete @rq before @rq_src. |
|
*/ |
|
int blk_rq_prep_clone(struct request *rq, struct request *rq_src, |
|
struct bio_set *bs, gfp_t gfp_mask, |
|
int (*bio_ctr)(struct bio *, struct bio *, void *), |
|
void *data) |
|
{ |
|
struct bio *bio, *bio_src; |
|
|
|
if (!bs) |
|
bs = &fs_bio_set; |
|
|
|
__rq_for_each_bio(bio_src, rq_src) { |
|
bio = bio_clone_fast(bio_src, gfp_mask, bs); |
|
if (!bio) |
|
goto free_and_out; |
|
|
|
if (bio_ctr && bio_ctr(bio, bio_src, data)) |
|
goto free_and_out; |
|
|
|
if (rq->bio) { |
|
rq->biotail->bi_next = bio; |
|
rq->biotail = bio; |
|
} else { |
|
rq->bio = rq->biotail = bio; |
|
} |
|
bio = NULL; |
|
} |
|
|
|
/* Copy attributes of the original request to the clone request. */ |
|
rq->__sector = blk_rq_pos(rq_src); |
|
rq->__data_len = blk_rq_bytes(rq_src); |
|
if (rq_src->rq_flags & RQF_SPECIAL_PAYLOAD) { |
|
rq->rq_flags |= RQF_SPECIAL_PAYLOAD; |
|
rq->special_vec = rq_src->special_vec; |
|
} |
|
rq->nr_phys_segments = rq_src->nr_phys_segments; |
|
rq->ioprio = rq_src->ioprio; |
|
|
|
if (rq->bio && blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask) < 0) |
|
goto free_and_out; |
|
|
|
return 0; |
|
|
|
free_and_out: |
|
if (bio) |
|
bio_put(bio); |
|
blk_rq_unprep_clone(rq); |
|
|
|
return -ENOMEM; |
|
} |
|
EXPORT_SYMBOL_GPL(blk_rq_prep_clone); |
|
|
|
int kblockd_schedule_work(struct work_struct *work) |
|
{ |
|
return queue_work(kblockd_workqueue, work); |
|
} |
|
EXPORT_SYMBOL(kblockd_schedule_work); |
|
|
|
int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, |
|
unsigned long delay) |
|
{ |
|
return mod_delayed_work_on(cpu, kblockd_workqueue, dwork, delay); |
|
} |
|
EXPORT_SYMBOL(kblockd_mod_delayed_work_on); |
|
|
|
/** |
|
* blk_start_plug - initialize blk_plug and track it inside the task_struct |
|
* @plug: The &struct blk_plug that needs to be initialized |
|
* |
|
* Description: |
|
* blk_start_plug() indicates to the block layer an intent by the caller |
|
* to submit multiple I/O requests in a batch. The block layer may use |
|
* this hint to defer submitting I/Os from the caller until blk_finish_plug() |
|
* is called. However, the block layer may choose to submit requests |
|
* before a call to blk_finish_plug() if the number of queued I/Os |
|
* exceeds %BLK_MAX_REQUEST_COUNT, or if the size of the I/O is larger than |
|
* %BLK_PLUG_FLUSH_SIZE. The queued I/Os may also be submitted early if |
|
* the task schedules (see below). |
|
* |
|
* Tracking blk_plug inside the task_struct will help with auto-flushing the |
|
* pending I/O should the task end up blocking between blk_start_plug() and |
|
* blk_finish_plug(). This is important from a performance perspective, but |
|
* also ensures that we don't deadlock. For instance, if the task is blocking |
|
* for a memory allocation, memory reclaim could end up wanting to free a |
|
* page belonging to that request that is currently residing in our private |
|
* plug. By flushing the pending I/O when the process goes to sleep, we avoid |
|
* this kind of deadlock. |
|
*/ |
|
void blk_start_plug(struct blk_plug *plug) |
|
{ |
|
struct task_struct *tsk = current; |
|
|
|
/* |
|
* If this is a nested plug, don't actually assign it. |
|
*/ |
|
if (tsk->plug) |
|
return; |
|
|
|
INIT_LIST_HEAD(&plug->mq_list); |
|
INIT_LIST_HEAD(&plug->cb_list); |
|
plug->rq_count = 0; |
|
plug->multiple_queues = false; |
|
plug->nowait = false; |
|
|
|
/* |
|
* Store ordering should not be needed here, since a potential |
|
* preempt will imply a full memory barrier |
|
*/ |
|
tsk->plug = plug; |
|
} |
|
EXPORT_SYMBOL(blk_start_plug); |
|
|
|
static void flush_plug_callbacks(struct blk_plug *plug, bool from_schedule) |
|
{ |
|
LIST_HEAD(callbacks); |
|
|
|
while (!list_empty(&plug->cb_list)) { |
|
list_splice_init(&plug->cb_list, &callbacks); |
|
|
|
while (!list_empty(&callbacks)) { |
|
struct blk_plug_cb *cb = list_first_entry(&callbacks, |
|
struct blk_plug_cb, |
|
list); |
|
list_del(&cb->list); |
|
cb->callback(cb, from_schedule); |
|
} |
|
} |
|
} |
|
|
|
struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, void *data, |
|
int size) |
|
{ |
|
struct blk_plug *plug = current->plug; |
|
struct blk_plug_cb *cb; |
|
|
|
if (!plug) |
|
return NULL; |
|
|
|
list_for_each_entry(cb, &plug->cb_list, list) |
|
if (cb->callback == unplug && cb->data == data) |
|
return cb; |
|
|
|
/* Not currently on the callback list */ |
|
BUG_ON(size < sizeof(*cb)); |
|
cb = kzalloc(size, GFP_ATOMIC); |
|
if (cb) { |
|
cb->data = data; |
|
cb->callback = unplug; |
|
list_add(&cb->list, &plug->cb_list); |
|
} |
|
return cb; |
|
} |
|
EXPORT_SYMBOL(blk_check_plugged); |
|
|
|
void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule) |
|
{ |
|
flush_plug_callbacks(plug, from_schedule); |
|
|
|
if (!list_empty(&plug->mq_list)) |
|
blk_mq_flush_plug_list(plug, from_schedule); |
|
} |
|
|
|
/** |
|
* blk_finish_plug - mark the end of a batch of submitted I/O |
|
* @plug: The &struct blk_plug passed to blk_start_plug() |
|
* |
|
* Description: |
|
* Indicate that a batch of I/O submissions is complete. This function |
|
* must be paired with an initial call to blk_start_plug(). The intent |
|
* is to allow the block layer to optimize I/O submission. See the |
|
* documentation for blk_start_plug() for more information. |
|
*/ |
|
void blk_finish_plug(struct blk_plug *plug) |
|
{ |
|
if (plug != current->plug) |
|
return; |
|
blk_flush_plug_list(plug, false); |
|
|
|
current->plug = NULL; |
|
} |
|
EXPORT_SYMBOL(blk_finish_plug); |
|
|
|
void blk_io_schedule(void) |
|
{ |
|
/* Prevent hang_check timer from firing at us during very long I/O */ |
|
unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2; |
|
|
|
if (timeout) |
|
io_schedule_timeout(timeout); |
|
else |
|
io_schedule(); |
|
} |
|
EXPORT_SYMBOL_GPL(blk_io_schedule); |
|
|
|
int __init blk_dev_init(void) |
|
{ |
|
BUILD_BUG_ON(REQ_OP_LAST >= (1 << REQ_OP_BITS)); |
|
BUILD_BUG_ON(REQ_OP_BITS + REQ_FLAG_BITS > 8 * |
|
sizeof_field(struct request, cmd_flags)); |
|
BUILD_BUG_ON(REQ_OP_BITS + REQ_FLAG_BITS > 8 * |
|
sizeof_field(struct bio, bi_opf)); |
|
|
|
/* used for unplugging and affects IO latency/throughput - HIGHPRI */ |
|
kblockd_workqueue = alloc_workqueue("kblockd", |
|
WQ_MEM_RECLAIM | WQ_HIGHPRI, 0); |
|
if (!kblockd_workqueue) |
|
panic("Failed to create kblockd\n"); |
|
|
|
blk_requestq_cachep = kmem_cache_create("request_queue", |
|
sizeof(struct request_queue), 0, SLAB_PANIC, NULL); |
|
|
|
blk_debugfs_root = debugfs_create_dir("block", NULL); |
|
|
|
return 0; |
|
}
|
|
|