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>
This commit is contained in:
Al Viro 2010-01-16 13:01:26 -05:00
parent df1a1ad297
commit 7b43a79f32

View file

@ -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);