xfs: require a relatively recent V5 filesystem for LARP mode

[platform/kernel/linux-starfive.git] / fs / xfs / xfs_xattr.c

diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
index 43e5c21..a3975f3 100644 (file)
--- a/fs/xfs/xfs_xattr.c
+++ b/fs/xfs/xfs_xattr.c
@@ -46,6 +46,17 @@ xfs_attr_grab_log_assist(
        if (xfs_sb_version_haslogxattrs(&mp->m_sb))
                return 0;
 
+       /*
+        * Check if the filesystem featureset is new enough to set this log
+        * incompat feature bit.  Strictly speaking, the minimum requirement is
+        * a V5 filesystem for the superblock field, but we'll require rmap
+        * or reflink to avoid having to deal with really old kernels.
+        */
+       if (!xfs_has_reflink(mp) && !xfs_has_rmapbt(mp)) {
+               error = -EOPNOTSUPP;
+               goto drop_incompat;
+       }
+
        /* Enable log-assisted xattrs. */
        error = xfs_add_incompat_log_feature(mp,
                        XFS_SB_FEAT_INCOMPAT_LOG_XATTRS);