From bb97a65730f975743b2d95b5cecadc5a254c0159 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Tue, 20 Jun 2017 19:14:30 -0400 Subject: dm io: fix duplicate bio completion due to missing ref count commit feb7695fe9fb83084aa29de0094774f4c9d4c9fc upstream. If only a subset of the devices associated with multiple regions support a given special operation (eg. DISCARD) then the dec_count() that is used to set error for the region must increment the io->count. Otherwise, when the dec_count() is called it can cause the dm-io caller's bio to be completed multiple times. As was reported against the dm-mirror target that had mirror legs with a mix of discard capabilities. Bug: https://bugzilla.kernel.org/show_bug.cgi?id=196077 Reported-by: Zhang Yi Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-io.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/md/dm-io.c') diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c index 81c5e1a1f363..1b84d2890fbf 100644 --- a/drivers/md/dm-io.c +++ b/drivers/md/dm-io.c @@ -300,6 +300,7 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, else if (rw & REQ_WRITE_SAME) special_cmd_max_sectors = q->limits.max_write_same_sectors; if ((rw & (REQ_DISCARD | REQ_WRITE_SAME)) && special_cmd_max_sectors == 0) { + atomic_inc(&io->count); dec_count(io, region, -EOPNOTSUPP); return; } -- cgit v1.2.3