5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Joseph Qi <joseph.qi@linux.alibaba.com>
commit 12c2ab42dbe227956c765e2674364bfca5de0533 upstream.
In o2hb_region_inc_user(), o2hb_dependent_users is incremented
unconditionally before calling o2hb_region_pin(). If the pin fails, the
counter is never decremented and any partially-pinned regions are never
unpinned, since the caller does not call o2hb_region_dec_user() on error.
The leaked counter causes subsequent o2hb_region_inc_user() calls to skip
pinning entirely (the > 1 check), leaving heartbeat regions unprotected.
Fix by rolling back on failure: call o2hb_region_unpin(NULL) to release
any partially-pinned regions and decrement o2hb_dependent_users to restore
the pre-increment state.
Link: https://lore.kernel.org/20260722124933.430554-4-joseph.qi@linux.alibaba.com (local)
Fixes: 58a3158a5d17 ("ocfs2/cluster: Pin/unpin o2hb regions")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <redacted>
Cc: Changwei Ge <redacted>
Cc: Jun Piao <redacted>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: <redacted>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ocfs2/cluster/heartbeat.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
--- a/fs/ocfs2/cluster/heartbeat.c
+++ b/fs/ocfs2/cluster/heartbeat.c
@@ -2441,8 +2441,13 @@ static int o2hb_region_inc_user(const ch
goto unlock;
if (bitmap_weight(o2hb_quorum_region_bitmap,
- O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF)
+ O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF) {
ret = o2hb_region_pin(NULL, false);
+ if (ret) {
+ o2hb_region_unpin(NULL);
+ o2hb_dependent_users--;
+ }
+ }
unlock:
spin_unlock(&o2hb_live_lock);