linux-kernel - [PATCH 1/1] fs: fix lock imbalance in do_remount

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Date:	Wed, 13 May 2009 21:21:12 +0200
From:	Jiri Slaby <jirislaby@...il.com>
To:	viro@...iv.linux.org.uk
Cc:	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	Jiri Slaby <jirislaby@...il.com>
Subject: [PATCH 1/1] fs: fix lock imbalance in do_remount_sb()

Commit "Push BKL down into do_remount_sb()" pushed un/lock_kernel
into do_remount_sb but forgets to unlock it on fail paths. Fix
that.

Signed-off-by: Jiri Slaby <jirislaby@...il.com>
---
 fs/super.c |   12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/fs/super.c b/fs/super.c
index e4a0c5b..a64f362 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -548,18 +548,24 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force)
 	if ((flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY)) {
 		if (force)
 			mark_files_ro(sb);
-		else if (!fs_may_remount_ro(sb))
+		else if (!fs_may_remount_ro(sb)) {
+			unlock_kernel();
 			return -EBUSY;
+		}
 		retval = vfs_dq_off(sb, 1);
-		if (retval < 0 && retval != -ENOSYS)
+		if (retval < 0 && retval != -ENOSYS) {
+			unlock_kernel();
 			return -EBUSY;
+		}
 	}
 	remount_rw = !(flags & MS_RDONLY) && (sb->s_flags & MS_RDONLY);
 
 	if (sb->s_op->remount_fs) {
 		retval = sb->s_op->remount_fs(sb, &flags, data);
-		if (retval)
+		if (retval) {
+			unlock_kernel();
 			return retval;
+		}
 	}
 	sb->s_flags = (sb->s_flags & ~MS_RMT_MASK) | (flags & MS_RMT_MASK);
 	unlock_kernel();
-- 
1.6.3
caught by stanse
--
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