From 7b010826fbc63bcf1afb11abec4f8810464f02af Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Thu, 12 Jul 2012 15:12:58 +0100 Subject: [PATCH 02/41] dm thin: do not break sharing for a zero length write Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer --- drivers/md/dm-thin.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 14adc48..991e851 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -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; -- 1.7.1