Track in-progress writes on the merging snapshot device and delay merging the chunk until all writes to that chunk finish. Signed-off-by: Mikulas Patocka Reviewed-by: Mike Snitzer --- drivers/md/dm-snap.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) Index: linux-2.6.31-fast-new-2/drivers/md/dm-snap.c =================================================================== --- linux-2.6.31-fast-new-2.orig/drivers/md/dm-snap.c 2009-10-16 21:48:37.000000000 +0200 +++ linux-2.6.31-fast-new-2/drivers/md/dm-snap.c 2009-10-16 21:48:39.000000000 +0200 @@ -713,7 +713,8 @@ static void snapshot_merge_process(struc s->merge_write_interlock_n = 1; up_write(&s->lock); - /* !!! FIXME: wait until writes to this chunk drain */ + while (__chunk_is_tracked(s, old_chunk)) + msleep(1); dm_kcopyd_copy(s->kcopyd_client, &src, 1, &dest, 0, merge_callback, s); return; @@ -1489,7 +1490,11 @@ static int snapshot_merge_map(struct dm_ r = DM_MAPIO_SUBMITTED; goto out_unlock; } + remap_exception(s, e, bio, chunk); + + if (bio_rw(bio) == WRITE) + map_context->ptr = track_chunk(s, chunk); goto out_unlock; }