xfs: more swap extent fixes for dynamic fork offsets

[sfrench/cifs-2.6.git] / fs / xfs / xfs_dfrag.c

diff --git a/fs/xfs/xfs_dfrag.c b/fs/xfs/xfs_dfrag.c
index cd27c9d6c71f8b9014183fb504bc5183a8785a56..5bba29a07812cb761a9094e2ca1448491e99fc27 100644 (file)
--- a/fs/xfs/xfs_dfrag.c
+++ b/fs/xfs/xfs_dfrag.c
@@ -177,16 +177,26 @@ xfs_swap_extents_check_format(
            XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) > tip->i_df.if_ext_max)
                return EINVAL;
 
-       /* Check root block of temp in btree form to max in target */
+       /*
+        * If we are in a btree format, check that the temp root block will fit
+        * in the target and that it has enough extents to be in btree format
+        * in the target.
+        *
+        * Note that we have to be careful to allow btree->extent conversions
+        * (a common defrag case) which will occur when the temp inode is in
+        * extent format...
+        */
        if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
-           XFS_IFORK_BOFF(ip) &&
-           tip->i_df.if_broot_bytes > XFS_IFORK_BOFF(ip))
+           ((XFS_IFORK_BOFF(ip) &&
+             tip->i_df.if_broot_bytes > XFS_IFORK_BOFF(ip)) ||
+            XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) <= ip->i_df.if_ext_max))
                return EINVAL;
 
-       /* Check root block of target in btree form to max in temp */
+       /* Reciprocal target->temp btree format checks */
        if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
-           XFS_IFORK_BOFF(tip) &&
-           ip->i_df.if_broot_bytes > XFS_IFORK_BOFF(tip))
+           ((XFS_IFORK_BOFF(tip) &&
+             ip->i_df.if_broot_bytes > XFS_IFORK_BOFF(tip)) ||
+            XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) <= tip->i_df.if_ext_max))
                return EINVAL;
 
        return 0;