[PATCH] dm clone: balance ios_in_flight on fail-mode I/O kills

[Samuel Moelius]

dm-clone increments ios_in_flight before mapping a bio.  When the target
is in fail mode, map() returns DM_MAPIO_KILL and the device-mapper core
completes the bio without calling the target end_io hook.

That leaves ios_in_flight permanently elevated for each killed bio. The
target can then wait for in-flight I/O that will never complete.

Drop the ios_in_flight reference before returning DM_MAPIO_KILL from the
fail-mode path.

Assisted-by: Codex:gpt-5.5-cyber-preview
Signed-off-by: Samuel Moelius <sam.moelius@xxxxxxxxxxxxxxx>
---
 drivers/md/dm-clone-target.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-clone-target.c b/drivers/md/dm-clone-target.c
index c0f9b93983d4..701e03dc2685 100644
--- a/drivers/md/dm-clone-target.c
+++ b/drivers/md/dm-clone-target.c
@@ -1316,11 +1316,11 @@ static int clone_map(struct dm_target *ti, struct bio *bio)
 	struct clone *clone = ti->private;
 	unsigned long region_nr;
 
-	atomic_inc(&clone->ios_in_flight);
-
 	if (unlikely(get_clone_mode(clone) == CM_FAIL))
 		return DM_MAPIO_KILL;
 
+	atomic_inc(&clone->ios_in_flight);
+
 	/*
 	 * REQ_PREFLUSH bios carry no data:
 	 *
-- 
2.43.0