| From 2b5460d3cf35a95a03a598ac53c0423d15dca6a4 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 6 Aug 2020 23:18:09 -0700 |
| Subject: ocfs2: fix unbalanced locking |
| |
| From: Pavel Machek <pavel@ucw.cz> |
| |
| [ Upstream commit 57c720d4144a9c2b88105c3e8f7b0e97e4b5cc93 ] |
| |
| 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. |
| |
| Fixes: 4cd9973f9ff6 ("ocfs2: avoid inode removal while nfsd is accessing it") |
| Signed-off-by: Pavel Machek (CIP) <pavel@denx.de> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| 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> |
| Link: http://lkml.kernel.org/r/20200724124443.GA28164@duo.ucw.cz |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| fs/ocfs2/dlmglue.c | 8 +++++++- |
| 1 file changed, 7 insertions(+), 1 deletion(-) |
| |
| diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c |
| index 751bc4dc74663..8e3a369086dbd 100644 |
| --- a/fs/ocfs2/dlmglue.c |
| +++ b/fs/ocfs2/dlmglue.c |
| @@ -2871,9 +2871,15 @@ int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex) |
| |
| 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; |
| } |
| |
| -- |
| 2.25.1 |
| |
