Btrfs: Add checks for last byte in disk to allocator grouping

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a340eeedd6c77ad8f1734e8669c4c02891d574ed..9e0869959cde37bcf15f1efc51d69754ab3a870f 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1611,8 +1611,13 @@ check_pending:
        }
        ins->offset = num_bytes;
        btrfs_free_path(path);
-       if (last_ptr)
+       if (last_ptr) {
                *last_ptr = ins->objectid + ins->offset;
+               if (*last_ptr ==
+                   btrfs_super_total_bytes(&root->fs_info->super_copy)) {
+                       *last_ptr = 0;
+               }
+       }
        return 0;
 
 new_group: