NTFS: Correct sparse file handling. The compressed values need to be

      checked and set in the ntfs inode as done for compressed files
      and the compressed size needs to be used for vfs inode->i_blocks
      instead of the allocated size, again, as done for compressed files.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>

1 files changed, 8 insertions, 7 deletions

diff --git a/fs/ntfs/layout.h b/fs/ntfs/layout.h
index 7cb8806d455..8d1f1326612 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;