diff options
| author | Mike Snitzer <snitzer@redhat.com> | 2017-06-20 19:14:30 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-11 16:19:47 +0100 |
| commit | bb97a65730f975743b2d95b5cecadc5a254c0159 (patch) | |
| tree | 325a85bcf5facf5f4b22c8e711e467d3ced6d5b4 | |
| parent | e7f17d033e58acce9df40bc44ed804720417ca2e (diff) | |
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 <yizhan@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/md/dm-io.c | 1 |
1 files changed, 1 insertions, 0 deletions
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; } |