NTFS: Add support for sparse files which have a compression unit of 0.

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

1 files changed, 17 insertions, 8 deletions

diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index a92b9e9db91d..7a568eb7d80f 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -1695,7 +1695,9 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni, const u32 data_size)
                         a->data.non_resident.initialized_size =
                         cpu_to_sle64(attr_size);
         if (NInoSparse(ni) || NInoCompressed(ni)) {
-                a->data.non_resident.compression_unit = 4;
+                a->data.non_resident.compression_unit = 0;
+                if (NInoCompressed(ni) || vol->major_ver < 3)
+                        a->data.non_resident.compression_unit = 4;
                 a->data.non_resident.compressed_size =
                                 a->data.non_resident.allocated_size;
         } else
@@ -1714,13 +1716,20 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni, const u32 data_size)
         ni->allocated_size = new_size;
         if (NInoSparse(ni) || NInoCompressed(ni)) {
                 ni->itype.compressed.size = ni->allocated_size;
-                ni->itype.compressed.block_size = 1U <<
-                                (a->data.non_resident.compression_unit +
-                                vol->cluster_size_bits);
-                ni->itype.compressed.block_size_bits =
-                                ffs(ni->itype.compressed.block_size) - 1;
-                ni->itype.compressed.block_clusters = 1U <<
-                                a->data.non_resident.compression_unit;
+                if (a->data.non_resident.compression_unit) {
+                        ni->itype.compressed.block_size = 1U << (a->data.
+                                        non_resident.compression_unit +
+                                        vol->cluster_size_bits);
+                        ni->itype.compressed.block_size_bits =
+                                        ffs(ni->itype.compressed.block_size) -
+                                        1;
+                        ni->itype.compressed.block_clusters = 1U <<
+                                        a->data.non_resident.compression_unit;
+                } else {
+                        ni->itype.compressed.block_size = 0;
+                        ni->itype.compressed.block_size_bits = 0;
+                        ni->itype.compressed.block_clusters = 0;
+                }
                 vi->i_blocks = ni->itype.compressed.size >> 9;
         } else
                 vi->i_blocks = ni->allocated_size >> 9;