From 42d6a8ce3c3f70bf77a40ace385f59e1b5b9918f Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Sun, 19 Oct 2014 07:52:44 -0400 Subject: [PATCH] dm thin: refactor requeue_io to eliminate spinlock bouncing Also refactor some other bio_list erroring helpers. Signed-off-by: Mike Snitzer --- drivers/md/dm-thin.c | 43 +++++++++++++++++++++++-------------------- 1 file changed, 23 insertions(+), 20 deletions(-) diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 575e3ed723cc..fb05f6a4bbfd 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -457,21 +457,32 @@ struct dm_thin_endio_hook { struct rb_node rb_node; }; -static void requeue_bio_list(struct thin_c *tc, struct bio_list *master) +static void __merge_bio_list(struct bio_list *bios, struct bio_list *master) +{ + bio_list_merge(bios, master); + bio_list_init(master); +} + +static void error_bio_list(struct bio_list *bios, int error) { struct bio *bio; + + while ((bio = bio_list_pop(bios))) + bio_endio(bio, error); +} + +static void error_thin_bio_list(struct thin_c *tc, struct bio_list *master, int error) +{ struct bio_list bios; unsigned long flags; bio_list_init(&bios); spin_lock_irqsave(&tc->lock, flags); - bio_list_merge(&bios, master); - bio_list_init(master); + __merge_bio_list(&bios, master); spin_unlock_irqrestore(&tc->lock, flags); - while ((bio = bio_list_pop(&bios))) - bio_endio(bio, DM_ENDIO_REQUEUE); + error_bio_list(&bios, error); } static void requeue_deferred_cells(struct thin_c *tc) @@ -493,26 +504,18 @@ static void requeue_deferred_cells(struct thin_c *tc) static void requeue_io(struct thin_c *tc) { - requeue_bio_list(tc, &tc->deferred_bio_list); - requeue_bio_list(tc, &tc->retry_on_resume_list); - requeue_deferred_cells(tc); -} - -static void error_thin_retry_list(struct thin_c *tc) -{ - struct bio *bio; - unsigned long flags; struct bio_list bios; + unsigned long flags; bio_list_init(&bios); spin_lock_irqsave(&tc->lock, flags); - bio_list_merge(&bios, &tc->retry_on_resume_list); - bio_list_init(&tc->retry_on_resume_list); + __merge_bio_list(&bios, &tc->deferred_bio_list); + __merge_bio_list(&bios, &tc->retry_on_resume_list); spin_unlock_irqrestore(&tc->lock, flags); - while ((bio = bio_list_pop(&bios))) - bio_io_error(bio); + error_bio_list(&bios, DM_ENDIO_REQUEUE); + requeue_deferred_cells(tc); } static void error_retry_list(struct pool *pool) @@ -521,7 +524,7 @@ static void error_retry_list(struct pool *pool) rcu_read_lock(); list_for_each_entry_rcu(tc, &pool->active_thins, list) - error_thin_retry_list(tc); + error_thin_bio_list(tc, &tc->retry_on_resume_list, -EIO); rcu_read_unlock(); } @@ -1752,7 +1755,7 @@ static void process_thin_deferred_bios(struct thin_c *tc) unsigned count = 0; if (tc->requeue_mode) { - requeue_bio_list(tc, &tc->deferred_bio_list); + error_thin_bio_list(tc, &tc->deferred_bio_list, DM_ENDIO_REQUEUE); return; } -- 2.20.1