Push lock_super() into the ->remount_fs() of filesystems that care about it

Note that since we can't run into contention between remount_fs and write_super
(due to exclusion on s_umount), we have to care only about filesystems that
touch lock_super() on their own.  Out of those ext3, ext4, hpfs, sysv and ufs
do need it; fat doesn't since its ->remount_fs() only accesses assign-once
data (basically, it's "we have no atime on directories and only have atime on
files for vfat; force nodiratime and possibly noatime into *flags").

[folded a build fix from hch]

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

1 files changed, 10 insertions, 1 deletions

diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index 2b4d2b6..a5ecabf 100644
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -1181,6 +1181,7 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
 	unsigned new_mount_opt, ufstype;
 	unsigned flags;
 	
+	lock_super(sb);
 	uspi = UFS_SB(sb)->s_uspi;
 	flags = UFS_SB(sb)->s_flags;
 	usb1 = ubh_get_usb_first(uspi);
@@ -1193,17 +1194,21 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
 	ufstype = UFS_SB(sb)->s_mount_opt & UFS_MOUNT_UFSTYPE;
 	new_mount_opt = 0;
 	ufs_set_opt (new_mount_opt, ONERROR_LOCK);
-	if (!ufs_parse_options (data, &new_mount_opt))
+	if (!ufs_parse_options (data, &new_mount_opt)) {
+		unlock_super(sb);
 		return -EINVAL;
+	}
 	if (!(new_mount_opt & UFS_MOUNT_UFSTYPE)) {
 		new_mount_opt |= ufstype;
 	} else if ((new_mount_opt & UFS_MOUNT_UFSTYPE) != ufstype) {
 		printk("ufstype can't be changed during remount\n");
+		unlock_super(sb);
 		return -EINVAL;
 	}
 
 	if ((*mount_flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
 		UFS_SB(sb)->s_mount_opt = new_mount_opt;
+		unlock_super(sb);
 		return 0;
 	}
 	
@@ -1228,6 +1233,7 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
 #ifndef CONFIG_UFS_FS_WRITE
 		printk("ufs was compiled with read-only support, "
 		"can't be mounted as read-write\n");
+		unlock_super(sb);
 		return -EINVAL;
 #else
 		if (ufstype != UFS_MOUNT_UFSTYPE_SUN && 
@@ -1236,16 +1242,19 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
 		    ufstype != UFS_MOUNT_UFSTYPE_SUNx86 &&
 		    ufstype != UFS_MOUNT_UFSTYPE_UFS2) {
 			printk("this ufstype is read-only supported\n");
+			unlock_super(sb);
 			return -EINVAL;
 		}
 		if (!ufs_read_cylinder_structures(sb)) {
 			printk("failed during remounting\n");
+			unlock_super(sb);
 			return -EPERM;
 		}
 		sb->s_flags &= ~MS_RDONLY;
 #endif
 	}
 	UFS_SB(sb)->s_mount_opt = new_mount_opt;
+	unlock_super(sb);
 	return 0;
 }