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dm thin: fix deadlock in __requeue_bio_list

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The spin lock in requeue_io() was held for too long, allowing deadlock.
Don't worry, due to other issues addressed in the following "dm thin:
fix noflush suspend IO queueing" commit, this code was never called.

Fix this by taking the spin lock for a much shorter period of time.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Joe Thornber 2014-03-03 15:46:42 +00:00 committed by Mike Snitzer
parent 3e1a069909
commit 18adc57779
1 changed files with 7 additions and 6 deletions
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13
drivers/md/dm-thin.c
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@ -369,14 +369,18 @@ struct dm_thin_endio_hook {
struct dm_thin_new_mapping *overwrite_mapping; struct dm_thin_new_mapping *overwrite_mapping;
}; };
static void __requeue_bio_list(struct thin_c *tc, struct bio_list *master) static void requeue_bio_list(struct thin_c *tc, struct bio_list *master)
{ {
struct bio *bio; struct bio *bio;
struct bio_list bios; struct bio_list bios;
unsigned long flags;
bio_list_init(&bios); bio_list_init(&bios);
spin_lock_irqsave(&tc->pool->lock, flags);
bio_list_merge(&bios, master); bio_list_merge(&bios, master);
bio_list_init(master); bio_list_init(master);
spin_unlock_irqrestore(&tc->pool->lock, flags);
while ((bio = bio_list_pop(&bios))) { while ((bio = bio_list_pop(&bios))) {
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook)); struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
@ -391,12 +395,9 @@ static void __requeue_bio_list(struct thin_c *tc, struct bio_list *master)
static void requeue_io(struct thin_c *tc) static void requeue_io(struct thin_c *tc)
{ {
struct pool *pool = tc->pool; struct pool *pool = tc->pool;
unsigned long flags;
spin_lock_irqsave(&pool->lock, flags); requeue_bio_list(tc, &pool->deferred_bios);
__requeue_bio_list(tc, &pool->deferred_bios); requeue_bio_list(tc, &pool->retry_on_resume_list);
__requeue_bio_list(tc, &pool->retry_on_resume_list);
spin_unlock_irqrestore(&pool->lock, flags);
} }
static void error_retry_list(struct pool *pool) static void error_retry_list(struct pool *pool)