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 2b4d2b6234df..a5ecabfdc976 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;
 }