ocfs2: cluster: fix o2hb_dependent_users leak on pin failure

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
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 <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

0 files changed, 0 insertions, 0 deletions