1 files changed, 8 insertions, 7 deletions

diff --git a/fs/ntfs/layout.h b/fs/ntfs/layout.h
index 7cb8806d4559..8d1f1326612f 100644
--- a/fs/ntfs/layout.h
+++ b/fs/ntfs/layout.h
@@ -749,10 +749,11 @@ typedef struct {
                                 record header aligned to 8-byte boundary. */
 /* 34*/                 u8 compression_unit; /* The compression unit expressed
                                 as the log to the base 2 of the number of
-                                clusters in a compression unit. 0 means not
-                                compressed. (This effectively limits the
+                                clusters in a compression unit.  0 means not
+                                compressed.  (This effectively limits the
                                 compression unit size to be a power of two
-                                clusters.) WinNT4 only uses a value of 4. */
+                                clusters.)  WinNT4 only uses a value of 4.
+                                Sparse files also have this set to 4. */
 /* 35*/                 u8 reserved[5];         /* Align to 8-byte boundary. */
 /* The sizes below are only used when lowest_vcn is zero, as otherwise it would
    be difficult to keep them up-to-date.*/
@@ -772,10 +773,10 @@ typedef struct {
                                 data_size. */
 /* sizeof(uncompressed attr) = 64*/
 /* 64*/                 sle64 compressed_size;  /* Byte size of the attribute
-                                value after compression. Only present when
-                                compressed. Always is a multiple of the
-                                cluster size. Represents the actual amount of
-                                disk space being used on the disk. */
+                                value after compression.  Only present when
+                                compressed or sparse.  Always is a multiple of
+                                the cluster size.  Represents the actual amount
+                                of disk space being used on the disk. */
 /* sizeof(compressed attr) = 72*/
                 } __attribute__ ((__packed__)) non_resident;
         } __attribute__ ((__packed__)) data;