From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 16 Jan 2010 18:01:26 +0000 (-0500)
Subject: mnt_flags fixes in do_remount()
X-Git-Tag: v2.6.33-rc5~25^2~2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7b43a79f32c0a05e7562043af98e25c05c89b18e;p=platform%2Fkernel%2Flinux-exynos.git

mnt_flags fixes in do_remount()

* need vfsmount_lock over modifying it
* need to preserve MNT_SHARED/MNT_UNBINDABLE

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/fs/namespace.c b/fs/namespace.c
index 4de493e..779293e 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1536,8 +1536,12 @@ static int do_remount(struct path *path, int flags, int mnt_flags,
 		err = change_mount_flags(path->mnt, flags);
 	else
 		err = do_remount_sb(sb, flags, data, 0);
-	if (!err)
+	if (!err) {
+		spin_lock(&vfsmount_lock);
+		mnt_flags |= path->mnt->mnt_flags & MNT_PNODE_MASK;
 		path->mnt->mnt_flags = mnt_flags;
+		spin_unlock(&vfsmount_lock);
+	}
 	up_write(&sb->s_umount);
 	if (!err) {
 		security_sb_post_remount(path->mnt, flags, data);