mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 10:04:12 +08:00
7cc2623d1c
Although the original intent was to use blk_update_request() in stacking block drivers only, it is used much more widely today. Reflect this in the documentation block above this function. See also: * commit32fab448e5
("block: add request update interface"). * commit2e60e02297
("block: clean up request completion API"). * commited6565e734
("block: handle partial completions for special payload requests"). Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20210519175226.8853-1-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
1789 lines
47 KiB
C
1789 lines
47 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
* Copyright (C) 1994, Karl Keyte: Added support for disk statistics
|
|
* Elevator latency, (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
|
|
* Queue request tables / lock, selectable elevator, Jens Axboe <axboe@suse.de>
|
|
* kernel-doc documentation started by NeilBrown <neilb@cse.unsw.edu.au>
|
|
* - July2000
|
|
* bio rewrite, highmem i/o, etc, Jens Axboe <axboe@suse.de> - may 2001
|
|
*/
|
|
|
|
/*
|
|
* This handles all read/write requests to block devices
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/backing-dev.h>
|
|
#include <linux/bio.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/blk-mq.h>
|
|
#include <linux/blk-pm.h>
|
|
#include <linux/highmem.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/kernel_stat.h>
|
|
#include <linux/string.h>
|
|
#include <linux/init.h>
|
|
#include <linux/completion.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/swap.h>
|
|
#include <linux/writeback.h>
|
|
#include <linux/task_io_accounting_ops.h>
|
|
#include <linux/fault-inject.h>
|
|
#include <linux/list_sort.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/ratelimit.h>
|
|
#include <linux/pm_runtime.h>
|
|
#include <linux/blk-cgroup.h>
|
|
#include <linux/t10-pi.h>
|
|
#include <linux/debugfs.h>
|
|
#include <linux/bpf.h>
|
|
#include <linux/psi.h>
|
|
#include <linux/sched/sysctl.h>
|
|
#include <linux/blk-crypto.h>
|
|
|
|
#define CREATE_TRACE_POINTS
|
|
#include <trace/events/block.h>
|
|
|
|
#include "blk.h"
|
|
#include "blk-mq.h"
|
|
#include "blk-mq-sched.h"
|
|
#include "blk-pm.h"
|
|
#include "blk-rq-qos.h"
|
|
|
|
struct dentry *blk_debugfs_root;
|
|
|
|
EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
|
|
EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
|
|
EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete);
|
|
EXPORT_TRACEPOINT_SYMBOL_GPL(block_split);
|
|
EXPORT_TRACEPOINT_SYMBOL_GPL(block_unplug);
|
|
EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_insert);
|
|
|
|
DEFINE_IDA(blk_queue_ida);
|
|
|
|
/*
|
|
* For queue allocation
|
|
*/
|
|
struct kmem_cache *blk_requestq_cachep;
|
|
|
|
/*
|
|
* Controlling structure to kblockd
|
|
*/
|
|
static struct workqueue_struct *kblockd_workqueue;
|
|
|
|
/**
|
|
* blk_queue_flag_set - atomically set a queue flag
|
|
* @flag: flag to be set
|
|
* @q: request queue
|
|
*/
|
|
void blk_queue_flag_set(unsigned int flag, struct request_queue *q)
|
|
{
|
|
set_bit(flag, &q->queue_flags);
|
|
}
|
|
EXPORT_SYMBOL(blk_queue_flag_set);
|
|
|
|
/**
|
|
* blk_queue_flag_clear - atomically clear a queue flag
|
|
* @flag: flag to be cleared
|
|
* @q: request queue
|
|
*/
|
|
void blk_queue_flag_clear(unsigned int flag, struct request_queue *q)
|
|
{
|
|
clear_bit(flag, &q->queue_flags);
|
|
}
|
|
EXPORT_SYMBOL(blk_queue_flag_clear);
|
|
|
|
/**
|
|
* blk_queue_flag_test_and_set - atomically test and set a queue flag
|
|
* @flag: flag to be set
|
|
* @q: request queue
|
|
*
|
|
* Returns the previous value of @flag - 0 if the flag was not set and 1 if
|
|
* the flag was already set.
|
|
*/
|
|
bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q)
|
|
{
|
|
return test_and_set_bit(flag, &q->queue_flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_queue_flag_test_and_set);
|
|
|
|
void blk_rq_init(struct request_queue *q, struct request *rq)
|
|
{
|
|
memset(rq, 0, sizeof(*rq));
|
|
|
|
INIT_LIST_HEAD(&rq->queuelist);
|
|
rq->q = q;
|
|
rq->__sector = (sector_t) -1;
|
|
INIT_HLIST_NODE(&rq->hash);
|
|
RB_CLEAR_NODE(&rq->rb_node);
|
|
rq->tag = BLK_MQ_NO_TAG;
|
|
rq->internal_tag = BLK_MQ_NO_TAG;
|
|
rq->start_time_ns = ktime_get_ns();
|
|
rq->part = NULL;
|
|
refcount_set(&rq->ref, 1);
|
|
blk_crypto_rq_set_defaults(rq);
|
|
}
|
|
EXPORT_SYMBOL(blk_rq_init);
|
|
|
|
#define REQ_OP_NAME(name) [REQ_OP_##name] = #name
|
|
static const char *const blk_op_name[] = {
|
|
REQ_OP_NAME(READ),
|
|
REQ_OP_NAME(WRITE),
|
|
REQ_OP_NAME(FLUSH),
|
|
REQ_OP_NAME(DISCARD),
|
|
REQ_OP_NAME(SECURE_ERASE),
|
|
REQ_OP_NAME(ZONE_RESET),
|
|
REQ_OP_NAME(ZONE_RESET_ALL),
|
|
REQ_OP_NAME(ZONE_OPEN),
|
|
REQ_OP_NAME(ZONE_CLOSE),
|
|
REQ_OP_NAME(ZONE_FINISH),
|
|
REQ_OP_NAME(ZONE_APPEND),
|
|
REQ_OP_NAME(WRITE_SAME),
|
|
REQ_OP_NAME(WRITE_ZEROES),
|
|
REQ_OP_NAME(SCSI_IN),
|
|
REQ_OP_NAME(SCSI_OUT),
|
|
REQ_OP_NAME(DRV_IN),
|
|
REQ_OP_NAME(DRV_OUT),
|
|
};
|
|
#undef REQ_OP_NAME
|
|
|
|
/**
|
|
* blk_op_str - Return string XXX in the REQ_OP_XXX.
|
|
* @op: REQ_OP_XXX.
|
|
*
|
|
* Description: Centralize block layer function to convert REQ_OP_XXX into
|
|
* string format. Useful in the debugging and tracing bio or request. For
|
|
* invalid REQ_OP_XXX it returns string "UNKNOWN".
|
|
*/
|
|
inline const char *blk_op_str(unsigned int op)
|
|
{
|
|
const char *op_str = "UNKNOWN";
|
|
|
|
if (op < ARRAY_SIZE(blk_op_name) && blk_op_name[op])
|
|
op_str = blk_op_name[op];
|
|
|
|
return op_str;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_op_str);
|
|
|
|
static const struct {
|
|
int errno;
|
|
const char *name;
|
|
} blk_errors[] = {
|
|
[BLK_STS_OK] = { 0, "" },
|
|
[BLK_STS_NOTSUPP] = { -EOPNOTSUPP, "operation not supported" },
|
|
[BLK_STS_TIMEOUT] = { -ETIMEDOUT, "timeout" },
|
|
[BLK_STS_NOSPC] = { -ENOSPC, "critical space allocation" },
|
|
[BLK_STS_TRANSPORT] = { -ENOLINK, "recoverable transport" },
|
|
[BLK_STS_TARGET] = { -EREMOTEIO, "critical target" },
|
|
[BLK_STS_NEXUS] = { -EBADE, "critical nexus" },
|
|
[BLK_STS_MEDIUM] = { -ENODATA, "critical medium" },
|
|
[BLK_STS_PROTECTION] = { -EILSEQ, "protection" },
|
|
[BLK_STS_RESOURCE] = { -ENOMEM, "kernel resource" },
|
|
[BLK_STS_DEV_RESOURCE] = { -EBUSY, "device resource" },
|
|
[BLK_STS_AGAIN] = { -EAGAIN, "nonblocking retry" },
|
|
|
|
/* device mapper special case, should not leak out: */
|
|
[BLK_STS_DM_REQUEUE] = { -EREMCHG, "dm internal retry" },
|
|
|
|
/* zone device specific errors */
|
|
[BLK_STS_ZONE_OPEN_RESOURCE] = { -ETOOMANYREFS, "open zones exceeded" },
|
|
[BLK_STS_ZONE_ACTIVE_RESOURCE] = { -EOVERFLOW, "active zones exceeded" },
|
|
|
|
/* everything else not covered above: */
|
|
[BLK_STS_IOERR] = { -EIO, "I/O" },
|
|
};
|
|
|
|
blk_status_t errno_to_blk_status(int errno)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(blk_errors); i++) {
|
|
if (blk_errors[i].errno == errno)
|
|
return (__force blk_status_t)i;
|
|
}
|
|
|
|
return BLK_STS_IOERR;
|
|
}
|
|
EXPORT_SYMBOL_GPL(errno_to_blk_status);
|
|
|
|
int blk_status_to_errno(blk_status_t status)
|
|
{
|
|
int idx = (__force int)status;
|
|
|
|
if (WARN_ON_ONCE(idx >= ARRAY_SIZE(blk_errors)))
|
|
return -EIO;
|
|
return blk_errors[idx].errno;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_status_to_errno);
|
|
|
|
static void print_req_error(struct request *req, blk_status_t status,
|
|
const char *caller)
|
|
{
|
|
int idx = (__force int)status;
|
|
|
|
if (WARN_ON_ONCE(idx >= ARRAY_SIZE(blk_errors)))
|
|
return;
|
|
|
|
printk_ratelimited(KERN_ERR
|
|
"%s: %s error, dev %s, sector %llu op 0x%x:(%s) flags 0x%x "
|
|
"phys_seg %u prio class %u\n",
|
|
caller, blk_errors[idx].name,
|
|
req->rq_disk ? req->rq_disk->disk_name : "?",
|
|
blk_rq_pos(req), req_op(req), blk_op_str(req_op(req)),
|
|
req->cmd_flags & ~REQ_OP_MASK,
|
|
req->nr_phys_segments,
|
|
IOPRIO_PRIO_CLASS(req->ioprio));
|
|
}
|
|
|
|
static void req_bio_endio(struct request *rq, struct bio *bio,
|
|
unsigned int nbytes, blk_status_t error)
|
|
{
|
|
if (error)
|
|
bio->bi_status = error;
|
|
|
|
if (unlikely(rq->rq_flags & RQF_QUIET))
|
|
bio_set_flag(bio, BIO_QUIET);
|
|
|
|
bio_advance(bio, nbytes);
|
|
|
|
if (req_op(rq) == REQ_OP_ZONE_APPEND && error == BLK_STS_OK) {
|
|
/*
|
|
* Partial zone append completions cannot be supported as the
|
|
* BIO fragments may end up not being written sequentially.
|
|
*/
|
|
if (bio->bi_iter.bi_size)
|
|
bio->bi_status = BLK_STS_IOERR;
|
|
else
|
|
bio->bi_iter.bi_sector = rq->__sector;
|
|
}
|
|
|
|
/* don't actually finish bio if it's part of flush sequence */
|
|
if (bio->bi_iter.bi_size == 0 && !(rq->rq_flags & RQF_FLUSH_SEQ))
|
|
bio_endio(bio);
|
|
}
|
|
|
|
void blk_dump_rq_flags(struct request *rq, char *msg)
|
|
{
|
|
printk(KERN_INFO "%s: dev %s: flags=%llx\n", msg,
|
|
rq->rq_disk ? rq->rq_disk->disk_name : "?",
|
|
(unsigned long long) rq->cmd_flags);
|
|
|
|
printk(KERN_INFO " sector %llu, nr/cnr %u/%u\n",
|
|
(unsigned long long)blk_rq_pos(rq),
|
|
blk_rq_sectors(rq), blk_rq_cur_sectors(rq));
|
|
printk(KERN_INFO " bio %p, biotail %p, len %u\n",
|
|
rq->bio, rq->biotail, blk_rq_bytes(rq));
|
|
}
|
|
EXPORT_SYMBOL(blk_dump_rq_flags);
|
|
|
|
/**
|
|
* blk_sync_queue - cancel any pending callbacks on a queue
|
|
* @q: the queue
|
|
*
|
|
* Description:
|
|
* The block layer may perform asynchronous callback activity
|
|
* on a queue, such as calling the unplug function after a timeout.
|
|
* A block device may call blk_sync_queue to ensure that any
|
|
* such activity is cancelled, thus allowing it to release resources
|
|
* that the callbacks might use. The caller must already have made sure
|
|
* that its ->submit_bio will not re-add plugging prior to calling
|
|
* this function.
|
|
*
|
|
* This function does not cancel any asynchronous activity arising
|
|
* out of elevator or throttling code. That would require elevator_exit()
|
|
* and blkcg_exit_queue() to be called with queue lock initialized.
|
|
*
|
|
*/
|
|
void blk_sync_queue(struct request_queue *q)
|
|
{
|
|
del_timer_sync(&q->timeout);
|
|
cancel_work_sync(&q->timeout_work);
|
|
}
|
|
EXPORT_SYMBOL(blk_sync_queue);
|
|
|
|
/**
|
|
* blk_set_pm_only - increment pm_only counter
|
|
* @q: request queue pointer
|
|
*/
|
|
void blk_set_pm_only(struct request_queue *q)
|
|
{
|
|
atomic_inc(&q->pm_only);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_set_pm_only);
|
|
|
|
void blk_clear_pm_only(struct request_queue *q)
|
|
{
|
|
int pm_only;
|
|
|
|
pm_only = atomic_dec_return(&q->pm_only);
|
|
WARN_ON_ONCE(pm_only < 0);
|
|
if (pm_only == 0)
|
|
wake_up_all(&q->mq_freeze_wq);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_clear_pm_only);
|
|
|
|
/**
|
|
* blk_put_queue - decrement the request_queue refcount
|
|
* @q: the request_queue structure to decrement the refcount for
|
|
*
|
|
* Decrements the refcount of the request_queue kobject. When this reaches 0
|
|
* we'll have blk_release_queue() called.
|
|
*
|
|
* Context: Any context, but the last reference must not be dropped from
|
|
* atomic context.
|
|
*/
|
|
void blk_put_queue(struct request_queue *q)
|
|
{
|
|
kobject_put(&q->kobj);
|
|
}
|
|
EXPORT_SYMBOL(blk_put_queue);
|
|
|
|
void blk_set_queue_dying(struct request_queue *q)
|
|
{
|
|
blk_queue_flag_set(QUEUE_FLAG_DYING, q);
|
|
|
|
/*
|
|
* When queue DYING flag is set, we need to block new req
|
|
* entering queue, so we call blk_freeze_queue_start() to
|
|
* prevent I/O from crossing blk_queue_enter().
|
|
*/
|
|
blk_freeze_queue_start(q);
|
|
|
|
if (queue_is_mq(q))
|
|
blk_mq_wake_waiters(q);
|
|
|
|
/* Make blk_queue_enter() reexamine the DYING flag. */
|
|
wake_up_all(&q->mq_freeze_wq);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_set_queue_dying);
|
|
|
|
/**
|
|
* blk_cleanup_queue - shutdown a request queue
|
|
* @q: request queue to shutdown
|
|
*
|
|
* Mark @q DYING, drain all pending requests, mark @q DEAD, destroy and
|
|
* put it. All future requests will be failed immediately with -ENODEV.
|
|
*
|
|
* Context: can sleep
|
|
*/
|
|
void blk_cleanup_queue(struct request_queue *q)
|
|
{
|
|
/* cannot be called from atomic context */
|
|
might_sleep();
|
|
|
|
WARN_ON_ONCE(blk_queue_registered(q));
|
|
|
|
/* mark @q DYING, no new request or merges will be allowed afterwards */
|
|
blk_set_queue_dying(q);
|
|
|
|
blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q);
|
|
blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
|
|
|
|
/*
|
|
* Drain all requests queued before DYING marking. Set DEAD flag to
|
|
* prevent that blk_mq_run_hw_queues() accesses the hardware queues
|
|
* after draining finished.
|
|
*/
|
|
blk_freeze_queue(q);
|
|
|
|
rq_qos_exit(q);
|
|
|
|
blk_queue_flag_set(QUEUE_FLAG_DEAD, q);
|
|
|
|
/* for synchronous bio-based driver finish in-flight integrity i/o */
|
|
blk_flush_integrity();
|
|
|
|
/* @q won't process any more request, flush async actions */
|
|
del_timer_sync(&q->backing_dev_info->laptop_mode_wb_timer);
|
|
blk_sync_queue(q);
|
|
|
|
if (queue_is_mq(q))
|
|
blk_mq_exit_queue(q);
|
|
|
|
/*
|
|
* In theory, request pool of sched_tags belongs to request queue.
|
|
* However, the current implementation requires tag_set for freeing
|
|
* requests, so free the pool now.
|
|
*
|
|
* Queue has become frozen, there can't be any in-queue requests, so
|
|
* it is safe to free requests now.
|
|
*/
|
|
mutex_lock(&q->sysfs_lock);
|
|
if (q->elevator)
|
|
blk_mq_sched_free_requests(q);
|
|
mutex_unlock(&q->sysfs_lock);
|
|
|
|
percpu_ref_exit(&q->q_usage_counter);
|
|
|
|
/* @q is and will stay empty, shutdown and put */
|
|
blk_put_queue(q);
|
|
}
|
|
EXPORT_SYMBOL(blk_cleanup_queue);
|
|
|
|
/**
|
|
* blk_queue_enter() - try to increase q->q_usage_counter
|
|
* @q: request queue pointer
|
|
* @flags: BLK_MQ_REQ_NOWAIT and/or BLK_MQ_REQ_PM
|
|
*/
|
|
int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
|
|
{
|
|
const bool pm = flags & BLK_MQ_REQ_PM;
|
|
|
|
while (true) {
|
|
bool success = false;
|
|
|
|
rcu_read_lock();
|
|
if (percpu_ref_tryget_live(&q->q_usage_counter)) {
|
|
/*
|
|
* The code that increments the pm_only counter is
|
|
* responsible for ensuring that that counter is
|
|
* globally visible before the queue is unfrozen.
|
|
*/
|
|
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 &&
|
|
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
|
|
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 =
|
|
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)
|
|
{
|
|
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;
|
|
int ret;
|
|
|
|
q = kmem_cache_alloc_node(blk_requestq_cachep,
|
|
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;
|
|
|
|
q->backing_dev_info = bdi_alloc(node_id);
|
|
if (!q->backing_dev_info)
|
|
goto fail_split;
|
|
|
|
q->stats = blk_alloc_queue_stats();
|
|
if (!q->stats)
|
|
goto fail_stats;
|
|
|
|
q->node = node_id;
|
|
|
|
atomic_set(&q->nr_active_requests_shared_sbitmap, 0);
|
|
|
|
timer_setup(&q->backing_dev_info->laptop_mode_wb_timer,
|
|
laptop_mode_timer_fn, 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_bdi;
|
|
|
|
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_bdi:
|
|
blk_free_queue_stats(q->stats);
|
|
fail_stats:
|
|
bdi_put(q->backing_dev_info);
|
|
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->bi_opf &= ~REQ_HIPRI;
|
|
|
|
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(stamp != now)) {
|
|
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;
|
|
}
|