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authorMike Snitzer <snitzer@redhat.com>2017-06-20 19:14:30 -0400
committerMike Snitzer <snitzer@redhat.com>2017-06-21 12:04:50 -0400
commitfeb7695fe9fb83084aa29de0094774f4c9d4c9fc (patch)
treedbdc175a3abd214ec6cef8531d07944407610421 /drivers
parent7def52b78a5fda14864aab9b6fd14f09a4d4ff72 (diff)
downloadlinux-stericsson-feb7695fe9fb83084aa29de0094774f4c9d4c9fc.tar.gz
dm io: fix duplicate bio completion due to missing ref count
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/md/dm-io.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 3702e502466d..8d5ca30f6551 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -317,8 +317,8 @@ static void do_region(int op, int op_flags, unsigned region,
else if (op == REQ_OP_WRITE_SAME)
special_cmd_max_sectors = q->limits.max_write_same_sectors;
if ((op == REQ_OP_DISCARD || op == REQ_OP_WRITE_ZEROES ||
- op == REQ_OP_WRITE_SAME) &&
- special_cmd_max_sectors == 0) {
+ op == REQ_OP_WRITE_SAME) && special_cmd_max_sectors == 0) {
+ atomic_inc(&io->count);
dec_count(io, region, -EOPNOTSUPP);
return;
}