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Diffstat (limited to 'drivers/md/dm-rq.c')
-rw-r--r--drivers/md/dm-rq.c104
1 files changed, 67 insertions, 37 deletions
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index ee48230a2952..182b67947dad 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -73,15 +73,24 @@ static void dm_old_start_queue(struct request_queue *q)
spin_unlock_irqrestore(q->queue_lock, flags);
}
+static void dm_mq_start_queue(struct request_queue *q)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ queue_flag_clear(QUEUE_FLAG_STOPPED, q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ blk_mq_start_stopped_hw_queues(q, true);
+ blk_mq_kick_requeue_list(q);
+}
+
void dm_start_queue(struct request_queue *q)
{
if (!q->mq_ops)
dm_old_start_queue(q);
- else {
- queue_flag_clear_unlocked(QUEUE_FLAG_STOPPED, q);
- blk_mq_start_stopped_hw_queues(q, true);
- blk_mq_kick_requeue_list(q);
- }
+ else
+ dm_mq_start_queue(q);
}
static void dm_old_stop_queue(struct request_queue *q)
@@ -89,27 +98,35 @@ static void dm_old_stop_queue(struct request_queue *q)
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
+ if (!blk_queue_stopped(q))
+ blk_stop_queue(q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+}
+
+static void dm_mq_stop_queue(struct request_queue *q)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
if (blk_queue_stopped(q)) {
spin_unlock_irqrestore(q->queue_lock, flags);
return;
}
- blk_stop_queue(q);
+ queue_flag_set(QUEUE_FLAG_STOPPED, q);
spin_unlock_irqrestore(q->queue_lock, flags);
+
+ /* Avoid that requeuing could restart the queue. */
+ blk_mq_cancel_requeue_work(q);
+ blk_mq_stop_hw_queues(q);
}
void dm_stop_queue(struct request_queue *q)
{
if (!q->mq_ops)
dm_old_stop_queue(q);
- else {
- spin_lock_irq(q->queue_lock);
- queue_flag_set(QUEUE_FLAG_STOPPED, q);
- spin_unlock_irq(q->queue_lock);
-
- blk_mq_cancel_requeue_work(q);
- blk_mq_stop_hw_queues(q);
- }
+ else
+ dm_mq_stop_queue(q);
}
static struct dm_rq_target_io *alloc_old_rq_tio(struct mapped_device *md,
@@ -319,21 +336,32 @@ static void dm_old_requeue_request(struct request *rq)
spin_unlock_irqrestore(q->queue_lock, flags);
}
-static void dm_mq_requeue_request(struct request *rq)
+static void __dm_mq_kick_requeue_list(struct request_queue *q, unsigned long msecs)
{
- struct request_queue *q = rq->q;
unsigned long flags;
- blk_mq_requeue_request(rq);
spin_lock_irqsave(q->queue_lock, flags);
if (!blk_queue_stopped(q))
- blk_mq_kick_requeue_list(q);
+ blk_mq_delay_kick_requeue_list(q, msecs);
spin_unlock_irqrestore(q->queue_lock, flags);
}
-static void dm_requeue_original_request(struct mapped_device *md,
- struct request *rq)
+void dm_mq_kick_requeue_list(struct mapped_device *md)
+{
+ __dm_mq_kick_requeue_list(dm_get_md_queue(md), 0);
+}
+EXPORT_SYMBOL(dm_mq_kick_requeue_list);
+
+static void dm_mq_delay_requeue_request(struct request *rq, unsigned long msecs)
+{
+ blk_mq_requeue_request(rq);
+ __dm_mq_kick_requeue_list(rq->q, msecs);
+}
+
+static void dm_requeue_original_request(struct dm_rq_target_io *tio, bool delay_requeue)
{
+ struct mapped_device *md = tio->md;
+ struct request *rq = tio->orig;
int rw = rq_data_dir(rq);
rq_end_stats(md, rq);
@@ -342,7 +370,7 @@ static void dm_requeue_original_request(struct mapped_device *md,
if (!rq->q->mq_ops)
dm_old_requeue_request(rq);
else
- dm_mq_requeue_request(rq);
+ dm_mq_delay_requeue_request(rq, delay_requeue ? 5000 : 0);
rq_completed(md, rw, false);
}
@@ -372,7 +400,7 @@ static void dm_done(struct request *clone, int error, bool mapped)
return;
else if (r == DM_ENDIO_REQUEUE)
/* The target wants to requeue the I/O */
- dm_requeue_original_request(tio->md, tio->orig);
+ dm_requeue_original_request(tio, false);
else {
DMWARN("unimplemented target endio return value: %d", r);
BUG();
@@ -612,20 +640,23 @@ static int dm_old_prep_fn(struct request_queue *q, struct request *rq)
/*
* Returns:
- * 0 : the request has been processed
- * DM_MAPIO_REQUEUE : the original request needs to be requeued
+ * DM_MAPIO_* : the request has been processed as indicated
+ * DM_MAPIO_REQUEUE : the original request needs to be immediately requeued
* < 0 : the request was completed due to failure
*/
-static int map_request(struct dm_rq_target_io *tio, struct request *rq,
- struct mapped_device *md)
+static int map_request(struct dm_rq_target_io *tio)
{
int r;
struct dm_target *ti = tio->ti;
+ struct mapped_device *md = tio->md;
+ struct request *rq = tio->orig;
struct request *clone = NULL;
if (tio->clone) {
clone = tio->clone;
r = ti->type->map_rq(ti, clone, &tio->info);
+ if (r == DM_MAPIO_DELAY_REQUEUE)
+ return DM_MAPIO_REQUEUE; /* .request_fn requeue is always immediate */
} else {
r = ti->type->clone_and_map_rq(ti, rq, &tio->info, &clone);
if (r < 0) {
@@ -633,9 +664,8 @@ static int map_request(struct dm_rq_target_io *tio, struct request *rq,
dm_kill_unmapped_request(rq, r);
return r;
}
- if (r != DM_MAPIO_REMAPPED)
- return r;
- if (setup_clone(clone, rq, tio, GFP_ATOMIC)) {
+ if (r == DM_MAPIO_REMAPPED &&
+ setup_clone(clone, rq, tio, GFP_ATOMIC)) {
/* -ENOMEM */
ti->type->release_clone_rq(clone);
return DM_MAPIO_REQUEUE;
@@ -654,7 +684,10 @@ static int map_request(struct dm_rq_target_io *tio, struct request *rq,
break;
case DM_MAPIO_REQUEUE:
/* The target wants to requeue the I/O */
- dm_requeue_original_request(md, tio->orig);
+ break;
+ case DM_MAPIO_DELAY_REQUEUE:
+ /* The target wants to requeue the I/O after a delay */
+ dm_requeue_original_request(tio, true);
break;
default:
if (r > 0) {
@@ -664,10 +697,9 @@ static int map_request(struct dm_rq_target_io *tio, struct request *rq,
/* The target wants to complete the I/O */
dm_kill_unmapped_request(rq, r);
- return r;
}
- return 0;
+ return r;
}
static void dm_start_request(struct mapped_device *md, struct request *orig)
@@ -706,11 +738,9 @@ static void dm_start_request(struct mapped_device *md, struct request *orig)
static void map_tio_request(struct kthread_work *work)
{
struct dm_rq_target_io *tio = container_of(work, struct dm_rq_target_io, work);
- struct request *rq = tio->orig;
- struct mapped_device *md = tio->md;
- if (map_request(tio, rq, md) == DM_MAPIO_REQUEUE)
- dm_requeue_original_request(md, rq);
+ if (map_request(tio) == DM_MAPIO_REQUEUE)
+ dm_requeue_original_request(tio, false);
}
ssize_t dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device *md, char *buf)
@@ -896,7 +926,7 @@ static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
tio->ti = ti;
/* Direct call is fine since .queue_rq allows allocations */
- if (map_request(tio, rq, md) == DM_MAPIO_REQUEUE) {
+ if (map_request(tio) == DM_MAPIO_REQUEUE) {
/* Undo dm_start_request() before requeuing */
rq_end_stats(md, rq);
rq_completed(md, rq_data_dir(rq), false);
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-18 20:33:17 +0000