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 <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Joe Thornber 2012-07-27 15:08:14 +01:00 committed by Alasdair G Kergon
parent 40db5a5376
commit 4afdd680f7

View file

@ -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);