Commit 60049701 authored Jul 27, 2012 by Joe Thornber Committed by Alasdair G Kergon Jul 27, 2012

dm thin: avoid unnecessarily breaking sharing for flushes



There's no need to break sharing, triggering a copy, for a write that has no
data (i.e. a flush).

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>

parent 905386f8

drivers/md/dm-thin.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1315,7 +1315,7 @@ static void process_shared_bio(struct thin_c tc, struct bio bio,
		if (bio_detain(pool->prison, &key, bio, &cell))
		return;

		if (bio_data_dir(bio) == WRITE)
		if (bio_data_dir(bio) == WRITE && bio->bi_size)
		break_sharing(tc, bio, block, &key, lookup_result, cell);
		else {
		struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr;