diff mbox series

[021/163] ocfs2: fix unbalanced locking

Message ID 20200807061809.D9W48nBXK%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [001/163] mm/memory.c: avoid access flag update TLB flush for retried page fault | expand

Commit Message

Andrew Morton Aug. 7, 2020, 6:18 a.m. UTC 
From: Pavel Machek <pavel@ucw.cz>
Subject: ocfs2: fix unbalanced locking

Based on what fails, function can return with nfs_sync_rwlock either
locked or unlocked. That can not be right.

Always return with lock unlocked on error.

Link: http://lkml.kernel.org/r/20200724124443.GA28164@duo.ucw.cz
Fixes: 4cd9973f9ff6 ("ocfs2: avoid inode removal while nfsd is accessing it")
Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
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: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/ocfs2/dlmglue.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
diff mbox series

Patch

--- a/fs/ocfs2/dlmglue.c~ocfs2-fix-unbalanced-locking
+++ a/fs/ocfs2/dlmglue.c
@@ -2871,9 +2871,15 @@  int ocfs2_nfs_sync_lock(struct ocfs2_sup
 
 	status = ocfs2_cluster_lock(osb, lockres, ex ? LKM_EXMODE : LKM_PRMODE,
 				    0, 0);
-	if (status < 0)
+	if (status < 0) {
 		mlog(ML_ERROR, "lock on nfs sync lock failed %d\n", status);
 
+		if (ex)
+			up_write(&osb->nfs_sync_rwlock);
+		else
+			up_read(&osb->nfs_sync_rwlock);
+	}
+
 	return status;
 }