1 files changed, 6 insertions, 3 deletions

diff --git a/fs/xfs/xfs_bmap.h b/fs/xfs/xfs_bmap.h
index b13569a6179b..71ec9b6ecdfc 100644
--- a/fs/xfs/xfs_bmap.h
+++ b/fs/xfs/xfs_bmap.h
@@ -74,9 +74,12 @@ typedef	struct xfs_bmap_free
 #define XFS_BMAPI_IGSTATE       0x080   /* Ignore state - */
                                         /* combine contig. space */
 #define XFS_BMAPI_CONTIG        0x100   /* must allocate only one extent */
-#define XFS_BMAPI_CONVERT       0x200   /* unwritten extent conversion - */
-                                        /* need write cache flushing and no */
-                                        /* additional allocation alignments */
+/*
+ * unwritten extent conversion - this needs write cache flushing and no additional
+ * allocation alignments. When specified with XFS_BMAPI_PREALLOC it converts
+ * from written to unwritten, otherwise convert from unwritten to written.
+ */
+#define XFS_BMAPI_CONVERT       0x200
 
 #define XFS_BMAPI_FLAGS \
         { XFS_BMAPI_WRITE,      "WRITE" }, \