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Diffstat (limited to 'block/blk-core.c')
-rw-r--r--block/blk-core.c325
1 files changed, 165 insertions, 160 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index b2df55a65250..b9e857f4afe8 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -33,6 +33,7 @@
#include <linux/ratelimit.h>
#include <linux/pm_runtime.h>
#include <linux/blk-cgroup.h>
+#include <linux/debugfs.h>
#define CREATE_TRACE_POINTS
#include <trace/events/block.h>
@@ -42,6 +43,10 @@
#include "blk-mq-sched.h"
#include "blk-wbt.h"
+#ifdef CONFIG_DEBUG_FS
+struct dentry *blk_debugfs_root;
+#endif
+
EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete);
@@ -75,7 +80,7 @@ static void blk_clear_congested(struct request_list *rl, int sync)
* flip its congestion state for events on other blkcgs.
*/
if (rl == &rl->q->root_rl)
- clear_wb_congested(rl->q->backing_dev_info.wb.congested, sync);
+ clear_wb_congested(rl->q->backing_dev_info->wb.congested, sync);
#endif
}
@@ -86,7 +91,7 @@ static void blk_set_congested(struct request_list *rl, int sync)
#else
/* see blk_clear_congested() */
if (rl == &rl->q->root_rl)
- set_wb_congested(rl->q->backing_dev_info.wb.congested, sync);
+ set_wb_congested(rl->q->backing_dev_info->wb.congested, sync);
#endif
}
@@ -105,22 +110,6 @@ void blk_queue_congestion_threshold(struct request_queue *q)
q->nr_congestion_off = nr;
}
-/**
- * blk_get_backing_dev_info - get the address of a queue's backing_dev_info
- * @bdev: device
- *
- * Locates the passed device's request queue and returns the address of its
- * backing_dev_info. This function can only be called if @bdev is opened
- * and the return value is never NULL.
- */
-struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev)
-{
- struct request_queue *q = bdev_get_queue(bdev);
-
- return &q->backing_dev_info;
-}
-EXPORT_SYMBOL(blk_get_backing_dev_info);
-
void blk_rq_init(struct request_queue *q, struct request *rq)
{
memset(rq, 0, sizeof(*rq));
@@ -132,8 +121,6 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
rq->__sector = (sector_t) -1;
INIT_HLIST_NODE(&rq->hash);
RB_CLEAR_NODE(&rq->rb_node);
- rq->cmd = rq->__cmd;
- rq->cmd_len = BLK_MAX_CDB;
rq->tag = -1;
rq->internal_tag = -1;
rq->start_time = jiffies;
@@ -160,10 +147,8 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
void blk_dump_rq_flags(struct request *rq, char *msg)
{
- int bit;
-
- printk(KERN_INFO "%s: dev %s: type=%x, flags=%llx\n", msg,
- rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->cmd_type,
+ 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",
@@ -171,13 +156,6 @@ void blk_dump_rq_flags(struct request *rq, char *msg)
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));
-
- if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
- printk(KERN_INFO " cdb: ");
- for (bit = 0; bit < BLK_MAX_CDB; bit++)
- printk("%02x ", rq->cmd[bit]);
- printk("\n");
- }
}
EXPORT_SYMBOL(blk_dump_rq_flags);
@@ -588,7 +566,7 @@ void blk_cleanup_queue(struct request_queue *q)
blk_flush_integrity();
/* @q won't process any more request, flush async actions */
- del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer);
+ del_timer_sync(&q->backing_dev_info->laptop_mode_wb_timer);
blk_sync_queue(q);
if (q->mq_ops)
@@ -600,7 +578,8 @@ void blk_cleanup_queue(struct request_queue *q)
q->queue_lock = &q->__queue_lock;
spin_unlock_irq(lock);
- bdi_unregister(&q->backing_dev_info);
+ bdi_unregister(q->backing_dev_info);
+ put_disk_devt(q->disk_devt);
/* @q is and will stay empty, shutdown and put */
blk_put_queue(q);
@@ -608,17 +587,41 @@ void blk_cleanup_queue(struct request_queue *q)
EXPORT_SYMBOL(blk_cleanup_queue);
/* Allocate memory local to the request queue */
-static void *alloc_request_struct(gfp_t gfp_mask, void *data)
+static void *alloc_request_simple(gfp_t gfp_mask, void *data)
{
- int nid = (int)(long)data;
- return kmem_cache_alloc_node(request_cachep, gfp_mask, nid);
+ struct request_queue *q = data;
+
+ return kmem_cache_alloc_node(request_cachep, gfp_mask, q->node);
}
-static void free_request_struct(void *element, void *unused)
+static void free_request_simple(void *element, void *data)
{
kmem_cache_free(request_cachep, element);
}
+static void *alloc_request_size(gfp_t gfp_mask, void *data)
+{
+ struct request_queue *q = data;
+ struct request *rq;
+
+ rq = kmalloc_node(sizeof(struct request) + q->cmd_size, gfp_mask,
+ q->node);
+ if (rq && q->init_rq_fn && q->init_rq_fn(q, rq, gfp_mask) < 0) {
+ kfree(rq);
+ rq = NULL;
+ }
+ return rq;
+}
+
+static void free_request_size(void *element, void *data)
+{
+ struct request_queue *q = data;
+
+ if (q->exit_rq_fn)
+ q->exit_rq_fn(q, element);
+ kfree(element);
+}
+
int blk_init_rl(struct request_list *rl, struct request_queue *q,
gfp_t gfp_mask)
{
@@ -631,10 +634,15 @@ int blk_init_rl(struct request_list *rl, struct request_queue *q,
init_waitqueue_head(&rl->wait[BLK_RW_SYNC]);
init_waitqueue_head(&rl->wait[BLK_RW_ASYNC]);
- rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ, alloc_request_struct,
- free_request_struct,
- (void *)(long)q->node, gfp_mask,
- q->node);
+ if (q->cmd_size) {
+ rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ,
+ alloc_request_size, free_request_size,
+ q, gfp_mask, q->node);
+ } else {
+ rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ,
+ alloc_request_simple, free_request_simple,
+ q, gfp_mask, q->node);
+ }
if (!rl->rq_pool)
return -ENOMEM;
@@ -697,7 +705,6 @@ static void blk_rq_timed_out_timer(unsigned long data)
struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
{
struct request_queue *q;
- int err;
q = kmem_cache_alloc_node(blk_requestq_cachep,
gfp_mask | __GFP_ZERO, node_id);
@@ -712,17 +719,17 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
if (!q->bio_split)
goto fail_id;
- q->backing_dev_info.ra_pages =
+ q->backing_dev_info = bdi_alloc_node(gfp_mask, node_id);
+ if (!q->backing_dev_info)
+ goto fail_split;
+
+ q->backing_dev_info->ra_pages =
(VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
- q->backing_dev_info.capabilities = BDI_CAP_CGROUP_WRITEBACK;
- q->backing_dev_info.name = "block";
+ q->backing_dev_info->capabilities = BDI_CAP_CGROUP_WRITEBACK;
+ q->backing_dev_info->name = "block";
q->node = node_id;
- err = bdi_init(&q->backing_dev_info);
- if (err)
- goto fail_split;
-
- setup_timer(&q->backing_dev_info.laptop_mode_wb_timer,
+ setup_timer(&q->backing_dev_info->laptop_mode_wb_timer,
laptop_mode_timer_fn, (unsigned long) q);
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
INIT_LIST_HEAD(&q->queue_head);
@@ -772,7 +779,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
fail_ref:
percpu_ref_exit(&q->q_usage_counter);
fail_bdi:
- bdi_destroy(&q->backing_dev_info);
+ bdi_put(q->backing_dev_info);
fail_split:
bioset_free(q->bio_split);
fail_id:
@@ -825,15 +832,19 @@ EXPORT_SYMBOL(blk_init_queue);
struct request_queue *
blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
{
- struct request_queue *uninit_q, *q;
+ struct request_queue *q;
- uninit_q = blk_alloc_queue_node(GFP_KERNEL, node_id);
- if (!uninit_q)
+ q = blk_alloc_queue_node(GFP_KERNEL, node_id);
+ if (!q)
return NULL;
- q = blk_init_allocated_queue(uninit_q, rfn, lock);
- if (!q)
- blk_cleanup_queue(uninit_q);
+ q->request_fn = rfn;
+ if (lock)
+ q->queue_lock = lock;
+ if (blk_init_allocated_queue(q) < 0) {
+ blk_cleanup_queue(q);
+ return NULL;
+ }
return q;
}
@@ -841,30 +852,22 @@ EXPORT_SYMBOL(blk_init_queue_node);
static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio);
-struct request_queue *
-blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn,
- spinlock_t *lock)
-{
- if (!q)
- return NULL;
- q->fq = blk_alloc_flush_queue(q, NUMA_NO_NODE, 0);
+int blk_init_allocated_queue(struct request_queue *q)
+{
+ q->fq = blk_alloc_flush_queue(q, NUMA_NO_NODE, q->cmd_size);
if (!q->fq)
- return NULL;
+ return -ENOMEM;
+
+ if (q->init_rq_fn && q->init_rq_fn(q, q->fq->flush_rq, GFP_KERNEL))
+ goto out_free_flush_queue;
if (blk_init_rl(&q->root_rl, q, GFP_KERNEL))
- goto fail;
+ goto out_exit_flush_rq;
INIT_WORK(&q->timeout_work, blk_timeout_work);
- q->request_fn = rfn;
- q->prep_rq_fn = NULL;
- q->unprep_rq_fn = NULL;
q->queue_flags |= QUEUE_FLAG_DEFAULT;
- /* Override internal queue lock with supplied lock pointer */
- if (lock)
- q->queue_lock = lock;
-
/*
* This also sets hw/phys segments, boundary and size
*/
@@ -878,17 +881,19 @@ blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn,
/* init elevator */
if (elevator_init(q, NULL)) {
mutex_unlock(&q->sysfs_lock);
- goto fail;
+ goto out_exit_flush_rq;
}
mutex_unlock(&q->sysfs_lock);
+ return 0;
- return q;
-
-fail:
+out_exit_flush_rq:
+ if (q->exit_rq_fn)
+ q->exit_rq_fn(q, q->fq->flush_rq);
+out_free_flush_queue:
blk_free_flush_queue(q->fq);
wbt_exit(q);
- return NULL;
+ return -ENOMEM;
}
EXPORT_SYMBOL(blk_init_allocated_queue);
@@ -1024,25 +1029,6 @@ int blk_update_nr_requests(struct request_queue *q, unsigned int nr)
return 0;
}
-/*
- * Determine if elevator data should be initialized when allocating the
- * request associated with @bio.
- */
-static bool blk_rq_should_init_elevator(struct bio *bio)
-{
- if (!bio)
- return true;
-
- /*
- * Flush requests do not use the elevator so skip initialization.
- * This allows a request to share the flush and elevator data.
- */
- if (op_is_flush(bio->bi_opf))
- return false;
-
- return true;
-}
-
/**
* __get_request - get a free request
* @rl: request list to allocate from
@@ -1121,10 +1107,13 @@ static struct request *__get_request(struct request_list *rl, unsigned int op,
* request is freed. This guarantees icq's won't be destroyed and
* makes creating new ones safe.
*
+ * Flush requests do not use the elevator so skip initialization.
+ * This allows a request to share the flush and elevator data.
+ *
* Also, lookup icq while holding queue_lock. If it doesn't exist,
* it will be created after releasing queue_lock.
*/
- if (blk_rq_should_init_elevator(bio) && !blk_queue_bypass(q)) {
+ if (!op_is_flush(op) && !blk_queue_bypass(q)) {
rq_flags |= RQF_ELVPRIV;
q->nr_rqs_elvpriv++;
if (et->icq_cache && ioc)
@@ -1184,7 +1173,7 @@ fail_elvpriv:
* disturb iosched and blkcg but weird is bettern than dead.
*/
printk_ratelimited(KERN_WARNING "%s: dev %s: request aux data allocation failed, iosched may be disturbed\n",
- __func__, dev_name(q->backing_dev_info.dev));
+ __func__, dev_name(q->backing_dev_info->dev));
rq->rq_flags &= ~RQF_ELVPRIV;
rq->elv.icq = NULL;
@@ -1278,8 +1267,6 @@ static struct request *blk_old_get_request(struct request_queue *q, int rw,
{
struct request *rq;
- BUG_ON(rw != READ && rw != WRITE);
-
/* create ioc upfront */
create_io_context(gfp_mask, q->node);
@@ -1309,18 +1296,6 @@ struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask)
EXPORT_SYMBOL(blk_get_request);
/**
- * blk_rq_set_block_pc - initialize a request to type BLOCK_PC
- * @rq: request to be initialized
- *
- */
-void blk_rq_set_block_pc(struct request *rq)
-{
- rq->cmd_type = REQ_TYPE_BLOCK_PC;
- memset(rq->__cmd, 0, sizeof(rq->__cmd));
-}
-EXPORT_SYMBOL(blk_rq_set_block_pc);
-
-/**
* blk_requeue_request - put a request back on queue
* @q: request queue where request should be inserted
* @rq: request to be inserted
@@ -1510,6 +1485,30 @@ bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
return true;
}
+bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
+ struct bio *bio)
+{
+ unsigned short segments = blk_rq_nr_discard_segments(req);
+
+ if (segments >= queue_max_discard_segments(q))
+ goto no_merge;
+ if (blk_rq_sectors(req) + bio_sectors(bio) >
+ blk_rq_get_max_sectors(req, blk_rq_pos(req)))
+ goto no_merge;
+
+ req->biotail->bi_next = bio;
+ req->biotail = bio;
+ req->__data_len += bio->bi_iter.bi_size;
+ req->ioprio = ioprio_best(req->ioprio, bio_prio(bio));
+ req->nr_phys_segments = segments + 1;
+
+ blk_account_io_start(req, false);
+ return true;
+no_merge:
+ req_set_nomerge(q, req);
+ return false;
+}
+
/**
* blk_attempt_plug_merge - try to merge with %current's plugged list
* @q: request_queue new bio is being queued at
@@ -1538,12 +1537,11 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
{
struct blk_plug *plug;
struct request *rq;
- bool ret = false;
struct list_head *plug_list;
plug = current->plug;
if (!plug)
- goto out;
+ return false;
*request_count = 0;
if (q->mq_ops)
@@ -1552,7 +1550,7 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
plug_list = &plug->list;
list_for_each_entry_reverse(rq, plug_list, queuelist) {
- int el_ret;
+ bool merged = false;
if (rq->q == q) {
(*request_count)++;
@@ -1568,19 +1566,25 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
if (rq->q != q || !blk_rq_merge_ok(rq, bio))
continue;
- el_ret = blk_try_merge(rq, bio);
- if (el_ret == ELEVATOR_BACK_MERGE) {
- ret = bio_attempt_back_merge(q, rq, bio);
- if (ret)
- break;
- } else if (el_ret == ELEVATOR_FRONT_MERGE) {
- ret = bio_attempt_front_merge(q, rq, bio);
- if (ret)
- break;
+ switch (blk_try_merge(rq, bio)) {
+ case ELEVATOR_BACK_MERGE:
+ merged = bio_attempt_back_merge(q, rq, bio);
+ break;
+ case ELEVATOR_FRONT_MERGE:
+ merged = bio_attempt_front_merge(q, rq, bio);
+ break;
+ case ELEVATOR_DISCARD_MERGE:
+ merged = bio_attempt_discard_merge(q, rq, bio);
+ break;
+ default:
+ break;
}
+
+ if (merged)
+ return true;
}
-out:
- return ret;
+
+ return false;
}
unsigned int blk_plug_queued_count(struct request_queue *q)
@@ -1609,7 +1613,6 @@ out:
void init_request_from_bio(struct request *req, struct bio *bio)
{
- req->cmd_type = REQ_TYPE_FS;
if (bio->bi_opf & REQ_RAHEAD)
req->cmd_flags |= REQ_FAILFAST_MASK;
@@ -1623,8 +1626,8 @@ void init_request_from_bio(struct request *req, struct bio *bio)
static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio)
{
struct blk_plug *plug;
- int el_ret, where = ELEVATOR_INSERT_SORT;
- struct request *req;
+ int where = ELEVATOR_INSERT_SORT;
+ struct request *req, *free;
unsigned int request_count = 0;
unsigned int wb_acct;
@@ -1661,21 +1664,29 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio)
spin_lock_irq(q->queue_lock);
- el_ret = elv_merge(q, &req, bio);
- if (el_ret == ELEVATOR_BACK_MERGE) {
- if (bio_attempt_back_merge(q, req, bio)) {
- elv_bio_merged(q, req, bio);
- if (!attempt_back_merge(q, req))
- elv_merged_request(q, req, el_ret);
- goto out_unlock;
- }
- } else if (el_ret == ELEVATOR_FRONT_MERGE) {
- if (bio_attempt_front_merge(q, req, bio)) {
- elv_bio_merged(q, req, bio);
- if (!attempt_front_merge(q, req))
- elv_merged_request(q, req, el_ret);
- goto out_unlock;
- }
+ switch (elv_merge(q, &req, bio)) {
+ case ELEVATOR_BACK_MERGE:
+ if (!bio_attempt_back_merge(q, req, bio))
+ break;
+ elv_bio_merged(q, req, bio);
+ free = attempt_back_merge(q, req);
+ if (free)
+ __blk_put_request(q, free);
+ else
+ elv_merged_request(q, req, ELEVATOR_BACK_MERGE);
+ goto out_unlock;
+ case ELEVATOR_FRONT_MERGE:
+ if (!bio_attempt_front_merge(q, req, bio))
+ break;
+ elv_bio_merged(q, req, bio);
+ free = attempt_front_merge(q, req);
+ if (free)
+ __blk_put_request(q, free);
+ else
+ elv_merged_request(q, req, ELEVATOR_FRONT_MERGE);
+ goto out_unlock;
+ default:
+ break;
}
get_rq:
@@ -2452,14 +2463,6 @@ void blk_start_request(struct request *req)
wbt_issue(req->q->rq_wb, &req->issue_stat);
}
- /*
- * We are now handing the request to the hardware, initialize
- * resid_len to full count and add the timeout handler.
- */
- req->resid_len = blk_rq_bytes(req);
- if (unlikely(blk_bidi_rq(req)))
- req->next_rq->resid_len = blk_rq_bytes(req->next_rq);
-
BUG_ON(test_bit(REQ_ATOM_COMPLETE, &req->atomic_flags));
blk_add_timer(req);
}
@@ -2530,10 +2533,10 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
* TODO: tj: This is too subtle. It would be better to let
* low level drivers do what they see fit.
*/
- if (req->cmd_type == REQ_TYPE_FS)
+ if (!blk_rq_is_passthrough(req))
req->errors = 0;
- if (error && req->cmd_type == REQ_TYPE_FS &&
+ if (error && !blk_rq_is_passthrough(req) &&
!(req->rq_flags & RQF_QUIET)) {
char *error_type;
@@ -2605,7 +2608,7 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
req->__data_len -= total_bytes;
/* update sector only for requests with clear definition of sector */
- if (req->cmd_type == REQ_TYPE_FS)
+ if (!blk_rq_is_passthrough(req))
req->__sector += total_bytes >> 9;
/* mixed attributes always follow the first bio */
@@ -2683,8 +2686,8 @@ void blk_finish_request(struct request *req, int error)
BUG_ON(blk_queued_rq(req));
- if (unlikely(laptop_mode) && req->cmd_type == REQ_TYPE_FS)
- laptop_io_completion(&req->q->backing_dev_info);
+ if (unlikely(laptop_mode) && !blk_rq_is_passthrough(req))
+ laptop_io_completion(req->q->backing_dev_info);
blk_delete_timer(req);
@@ -3007,8 +3010,6 @@ EXPORT_SYMBOL_GPL(blk_rq_unprep_clone);
static void __blk_rq_prep_clone(struct request *dst, struct request *src)
{
dst->cpu = src->cpu;
- dst->cmd_flags = src->cmd_flags | REQ_NOMERGE;
- dst->cmd_type = src->cmd_type;
dst->__sector = blk_rq_pos(src);
dst->__data_len = blk_rq_bytes(src);
dst->nr_phys_segments = src->nr_phys_segments;
@@ -3484,5 +3485,9 @@ int __init blk_dev_init(void)
blk_requestq_cachep = kmem_cache_create("request_queue",
sizeof(struct request_queue), 0, SLAB_PANIC, NULL);
+#ifdef CONFIG_DEBUG_FS
+ blk_debugfs_root = debugfs_create_dir("block", NULL);
+#endif
+
return 0;
}