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- // 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/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_bio_queue);
- EXPORT_TRACEPOINT_SYMBOL_GPL(block_getrq);
- EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_insert);
- EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_issue);
- EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_merge);
- EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_requeue);
- EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_complete);
- 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;
- 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 || !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 &&
- (pm || (blk_pm_request_resume(q),
- !blk_queue_pm_only(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_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, BIOSET_NEED_BVECS);
- 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;
- }
- EXPORT_SYMBOL(blk_alloc_queue);
- /**
- * 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 hd_struct *part, unsigned int bytes)
- {
- return part->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 hd_struct *part,
- unsigned int bytes)
- {
- return false;
- }
- #endif /* CONFIG_FAIL_MAKE_REQUEST */
- static inline bool bio_check_ro(struct bio *bio, struct hd_struct *part)
- {
- const int op = bio_op(bio);
- if (part->policy && op_is_write(op)) {
- 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), part->partno);
- /* Older lvm-tools actually trigger this */
- return false;
- }
- return false;
- }
- static noinline int should_fail_bio(struct bio *bio)
- {
- if (should_fail_request(&bio->bi_disk->part0, 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)
- {
- 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 inline int blk_partition_remap(struct bio *bio)
- {
- struct hd_struct *p;
- int ret = -EIO;
- rcu_read_lock();
- p = __disk_get_part(bio->bi_disk, bio->bi_partno);
- if (unlikely(!p))
- goto out;
- if (unlikely(should_fail_request(p, bio->bi_iter.bi_size)))
- goto out;
- if (unlikely(bio_check_ro(bio, p)))
- goto out;
- if (bio_sectors(bio)) {
- if (bio_check_eod(bio, part_nr_sects_read(p)))
- goto out;
- bio->bi_iter.bi_sector += p->start_sect;
- trace_block_bio_remap(bio->bi_disk->queue, bio, part_devt(p),
- bio->bi_iter.bi_sector - p->start_sect);
- }
- bio->bi_partno = 0;
- ret = 0;
- out:
- rcu_read_unlock();
- return ret;
- }
- /*
- * 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 request_queue *q = bio->bi_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 (bio->bi_partno) {
- if (unlikely(blk_partition_remap(bio)))
- goto end_io;
- } else {
- if (unlikely(bio_check_ro(bio, &bio->bi_disk->part0)))
- goto end_io;
- if (unlikely(bio_check_eod(bio, get_capacity(bio->bi_disk))))
- 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))
- return false;
- blk_cgroup_bio_start(bio);
- blkcg_bio_issue_init(bio);
- if (!bio_flagged(bio, BIO_TRACE_COMPLETION)) {
- trace_block_bio_queue(q, 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_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_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_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_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_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_disk and bi_partno fields.
- *
- * 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_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 (unlikely(block_dump)) {
- char b[BDEVNAME_SIZE];
- printk(KERN_DEBUG "%s(%d): %s block %Lu on %s (%u sectors)\n",
- current->comm, task_pid_nr(current),
- op_is_write(bio_op(bio)) ? "WRITE" : "READ",
- (unsigned long long)bio->bi_iter.bi_sector,
- bio_devname(bio, b), 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;
- }
- /*
- * queue's settings related to segment counting like q->bounce_pfn
- * may differ from that of other stacking queues.
- * Recalculate it to check the request correctly on this queue's
- * limitation.
- */
- 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 hd_struct *part, unsigned long now, bool end)
- {
- unsigned long stamp;
- again:
- stamp = READ_ONCE(part->stamp);
- if (unlikely(stamp != now)) {
- if (likely(cmpxchg(&part->stamp, stamp, now) == stamp))
- __part_stat_add(part, io_ticks, end ? now - stamp : 1);
- }
- if (part->partno) {
- part = &part_to_disk(part)->part0;
- 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));
- struct hd_struct *part;
- part_stat_lock();
- part = req->part;
- part_stat_add(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));
- struct hd_struct *part;
- part_stat_lock();
- part = req->part;
- update_io_ticks(part, jiffies, true);
- part_stat_inc(part, ios[sgrp]);
- part_stat_add(part, nsecs[sgrp], now - req->start_time_ns);
- part_stat_unlock();
- hd_struct_put(part);
- }
- }
- void blk_account_io_start(struct request *rq)
- {
- if (!blk_do_io_stat(rq))
- return;
- rq->part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq));
- part_stat_lock();
- update_io_ticks(rq->part, jiffies, false);
- part_stat_unlock();
- }
- static unsigned long __part_start_io_acct(struct hd_struct *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;
- }
- unsigned long part_start_io_acct(struct gendisk *disk, struct hd_struct **part,
- struct bio *bio)
- {
- *part = disk_map_sector_rcu(disk, bio->bi_iter.bi_sector);
- return __part_start_io_acct(*part, bio_sectors(bio), bio_op(bio));
- }
- EXPORT_SYMBOL_GPL(part_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 hd_struct *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 part_end_io_acct(struct hd_struct *part, struct bio *bio,
- unsigned long start_time)
- {
- __part_end_io_acct(part, bio_op(bio), start_time);
- hd_struct_put(part);
- }
- EXPORT_SYMBOL_GPL(part_end_io_acct);
- 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 - Special helper function for request stacking drivers
- * @req: the request being processed
- * @error: block status code
- * @nr_bytes: number of bytes to complete @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.
- *
- * This special helper function is only for request stacking drivers
- * (e.g. request-based dm) so that they can handle partial completion.
- * Actual device drivers should use blk_mq_end_request instead.
- *
- * 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 both
- * blk_rq_bytes() and in blk_update_request().
- *
- * 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;
- }
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