From 4afdd680f7c106e1c87b6dd7af9751c282ecb4b0 Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Fri, 27 Jul 2012 15:08:14 +0100 Subject: dm thin: reduce number of metadata commits Reduce the number of metadata commits by using dm_thin_changed_this_transaction to check if metadata was changed on a per thin device granularity. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- drivers/md/dm-thin.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index bc9d08c0218b..98c50f9626d8 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -707,6 +707,12 @@ static void remap_to_origin(struct thin_c *tc, struct bio *bio) bio->bi_bdev = tc->origin_dev->bdev; } +static int bio_triggers_commit(struct thin_c *tc, struct bio *bio) +{ + return (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) && + dm_thin_changed_this_transaction(tc->td); +} + static void issue(struct thin_c *tc, struct bio *bio) { struct pool *pool = tc->pool; @@ -716,7 +722,7 @@ static void issue(struct thin_c *tc, struct bio *bio) * Batch together any FUA/FLUSH bios we find and then issue * a single commit for them in process_deferred_bios(). */ - if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) { + if (bio_triggers_commit(tc, bio)) { spin_lock_irqsave(&pool->lock, flags); bio_list_add(&pool->deferred_flush_bios, bio); spin_unlock_irqrestore(&pool->lock, flags); -- cgit v1.2.3