The xfs_quota returns ENOSYS when remove command is executed.
Reproducable with following steps.
    # mount -t xfs -o uquota /dev/sda7 /mnt/mp1
    # xfs_quota -x -c off -c remove
    XFS_QUOTARM: Function not implemented.
The remove command is allowed during quotaoff, but xfs_fs_set_xstate()
checks whether quota is running, and it leads to ENOSYS.
To solve this problem, add a check for X_QUOTARM.
Signed-off-by: Ryota Yamauchi <r-yamauchi@vf.jp.nec.com>
Signed-off-by: Utako Kusaka <u-kusaka@wm.jp.nec.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
 
        if (sb->s_flags & MS_RDONLY)
                return -EROFS;
-       if (!XFS_IS_QUOTA_RUNNING(mp))
+       if (op != Q_XQUOTARM && !XFS_IS_QUOTA_RUNNING(mp))
                return -ENOSYS;
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;