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>

fs/ntfs/ChangeLog

@@ -84,6 +84,10 @@ ToDo/Notes:
 	- Make fs/ntfs/namei.c::ntfs_get_{parent,dentry} static and move the
 	  definition of ntfs_export_ops from fs/ntfs/super.c to namei.c.  Also,
 	  declare ntfs_export_ops in fs/ntfs/ntfs.h.
+	- 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.
 
 2.1.22 - Many bug and race fixes and error handling improvements.
 

fs/ntfs/inode.c

@@ -1016,26 +1016,31 @@ skip_large_dir_stuff:
 		/* Setup the state. */
 		if (a->non_resident) {
 			NInoSetNonResident(ni);
-			if (a->flags & ATTR_COMPRESSION_MASK) {
-				NInoSetCompressed(ni);
-				if (vol->cluster_size > 4096) {
-					ntfs_error(vi->i_sb, "Found "
-						"compressed data but "
-						"compression is disabled due "
-						"to cluster size (%i) > 4kiB.",
-						vol->cluster_size);
-					goto unm_err_out;
-				}
-				if ((a->flags & ATTR_COMPRESSION_MASK)
-						!= ATTR_IS_COMPRESSED) {
-					ntfs_error(vi->i_sb, "Found "
-						"unknown compression method or "
-						"corrupt file.");
-					goto unm_err_out;
+			if (a->flags & (ATTR_COMPRESSION_MASK |
+					ATTR_IS_SPARSE)) {
+				if (a->flags & ATTR_COMPRESSION_MASK) {
+					NInoSetCompressed(ni);
+					if (vol->cluster_size > 4096) {
+						ntfs_error(vi->i_sb, "Found "
+							"compressed data but "
+							"compression is "
+							"disabled due to "
+							"cluster size (%i) > "
+							"4kiB.",
+							vol->cluster_size);
+						goto unm_err_out;
+					}
+					if ((a->flags & ATTR_COMPRESSION_MASK)
+							!= ATTR_IS_COMPRESSED) {
+						ntfs_error(vi->i_sb, "Found "
+							"unknown compression "
+							"method or corrupt "
+							"file.");
+						goto unm_err_out;
+					}
 				}
-				ni->itype.compressed.block_clusters = 1U <<
-						a->data.non_resident.
-						compression_unit;
+				if (a->flags & ATTR_IS_SPARSE)
+					NInoSetSparse(ni);
 				if (a->data.non_resident.compression_unit !=
 						4) {
 					ntfs_error(vi->i_sb, "Found "
@@ -1047,12 +1052,19 @@ skip_large_dir_stuff:
 					err = -EOPNOTSUPP;
 					goto unm_err_out;
 				}
+				ni->itype.compressed.block_clusters = 1U <<
+						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_size) - 1;
+				ni->itype.compressed.size = sle64_to_cpu(
+						a->data.non_resident.
+						compressed_size);
 			}
 			if (a->flags & ATTR_IS_ENCRYPTED) {
 				if (a->flags & ATTR_COMPRESSION_MASK) {
@@ -1062,27 +1074,19 @@ skip_large_dir_stuff:
 				}
 				NInoSetEncrypted(ni);
 			}
-			if (a->flags & ATTR_IS_SPARSE)
-				NInoSetSparse(ni);
 			if (a->data.non_resident.lowest_vcn) {
 				ntfs_error(vi->i_sb, "First extent of $DATA "
 						"attribute has non zero "
 						"lowest_vcn.");
 				goto unm_err_out;
 			}
-			/* Setup all the sizes. */
 			vi->i_size = sle64_to_cpu(
 					a->data.non_resident.data_size);
 			ni->initialized_size = sle64_to_cpu(
 					a->data.non_resident.initialized_size);
 			ni->allocated_size = sle64_to_cpu(
 					a->data.non_resident.allocated_size);
-			if (NInoCompressed(ni))
-				ni->itype.compressed.size = sle64_to_cpu(
-						a->data.non_resident.
-						compressed_size);
 		} else { /* Resident attribute. */
-			/* Setup all the sizes. */
 			vi->i_size = ni->initialized_size = le32_to_cpu(
 					a->data.resident.value_length);
 			ni->allocated_size = le32_to_cpu(a->length) -
@@ -1120,11 +1124,10 @@ no_data_attr_special_case:
 	 * sizes of all non-resident attributes present to give us the Linux
 	 * correct size that should go into i_blocks (after division by 512).
 	 */
-	if (S_ISDIR(vi->i_mode) || !NInoCompressed(ni))
-		vi->i_blocks = ni->allocated_size >> 9;
-	else
+	if (S_ISREG(vi->i_mode) && (NInoCompressed(ni) || NInoSparse(ni)))
 		vi->i_blocks = ni->itype.compressed.size >> 9;
-
+	else
+		vi->i_blocks = ni->allocated_size >> 9;
 	ntfs_debug("Done.");
 	return 0;
 
@@ -1226,14 +1229,13 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 					"linux-ntfs-dev@lists.sourceforge.net");
 			goto unm_err_out;
 		}
-		/* Resident attribute.  Setup all the sizes. */
 		vi->i_size = ni->initialized_size = le32_to_cpu(
 				a->data.resident.value_length);
 		ni->allocated_size = le32_to_cpu(a->length) -
 				le16_to_cpu(a->data.resident.value_offset);
 		if (vi->i_size > ni->allocated_size) {
-			ntfs_error(vi->i_sb, "Resident data attribute is "
-					"corrupt (size exceeds allocation).");
+			ntfs_error(vi->i_sb, "Resident attribute is corrupt "
+					"(size exceeds allocation).");
 			goto unm_err_out;
 		}
 	} else {
@@ -1249,43 +1251,50 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 					"the mapping pairs array.");
 			goto unm_err_out;
 		}
-		if (a->flags & ATTR_COMPRESSION_MASK) {
+		if (a->flags & (ATTR_COMPRESSION_MASK | ATTR_IS_SPARSE)) {
+			if (a->flags & ATTR_COMPRESSION_MASK) {
+				NInoSetCompressed(ni);
+				if ((ni->type != AT_DATA) || (ni->type ==
+						AT_DATA && ni->name_len)) {
+					ntfs_error(vi->i_sb, "Found compressed "
+							"non-data or named "
+							"data attribute.  "
+							"Please report you "
+							"saw this message to "
+							"linux-ntfs-dev@lists."
+							"sourceforge.net");
+					goto unm_err_out;
+				}
+				if (vol->cluster_size > 4096) {
+					ntfs_error(vi->i_sb, "Found compressed "
+							"attribute but "
+							"compression is "
+							"disabled due to "
+							"cluster size (%i) > "
+							"4kiB.",
+							vol->cluster_size);
+					goto unm_err_out;
+				}
+				if ((a->flags & ATTR_COMPRESSION_MASK) !=
+						ATTR_IS_COMPRESSED) {
+					ntfs_error(vi->i_sb, "Found unknown "
+							"compression method.");
+					goto unm_err_out;
+				}
+			}
 			if (NInoMstProtected(ni)) {
 				ntfs_error(vi->i_sb, "Found mst protected "
 						"attribute but the attribute "
-						"is compressed.  Please report "
-						"you saw this message to "
-						"linux-ntfs-dev@lists."
-						"sourceforge.net");
-				goto unm_err_out;
-			}
-			NInoSetCompressed(ni);
-			if ((ni->type != AT_DATA) || (ni->type == AT_DATA &&
-					ni->name_len)) {
-				ntfs_error(vi->i_sb, "Found compressed "
-						"non-data or named data "
-						"attribute.  Please report "
-						"you saw this message to "
+						"is %s.  Please report you "
+						"saw this message to "
 						"linux-ntfs-dev@lists."
-						"sourceforge.net");
-				goto unm_err_out;
-			}
-			if (vol->cluster_size > 4096) {
-				ntfs_error(vi->i_sb, "Found compressed "
-						"attribute but compression is "
-						"disabled due to cluster size "
-						"(%i) > 4kiB.",
-						vol->cluster_size);
-				goto unm_err_out;
-			}
-			if ((a->flags & ATTR_COMPRESSION_MASK) !=
-					ATTR_IS_COMPRESSED) {
-				ntfs_error(vi->i_sb, "Found unknown "
-						"compression method.");
+						"sourceforge.net",
+						NInoCompressed(ni) ?
+						"compressed" : "sparse");
 				goto unm_err_out;
 			}
-			ni->itype.compressed.block_clusters = 1U <<
-					a->data.non_resident.compression_unit;
+			if (a->flags & ATTR_IS_SPARSE)
+				NInoSetSparse(ni);
 			if (a->data.non_resident.compression_unit != 4) {
 				ntfs_error(vi->i_sb, "Found nonstandard "
 						"compression unit (%u instead "
@@ -1295,11 +1304,15 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 				err = -EOPNOTSUPP;
 				goto unm_err_out;
 			}
+			ni->itype.compressed.block_clusters = 1U <<
+					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.size = sle64_to_cpu(
+					a->data.non_resident.compressed_size);
 		}
 		if (a->flags & ATTR_IS_ENCRYPTED) {
 			if (a->flags & ATTR_COMPRESSION_MASK) {
@@ -1318,34 +1331,17 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 			}
 			NInoSetEncrypted(ni);
 		}
-		if (a->flags & ATTR_IS_SPARSE) {
-			if (NInoMstProtected(ni)) {
-				ntfs_error(vi->i_sb, "Found mst protected "
-						"attribute but the attribute "
-						"is sparse.  Please report "
-						"you saw this message to "
-						"linux-ntfs-dev@lists."
-						"sourceforge.net");
-				goto unm_err_out;
-			}
-			NInoSetSparse(ni);
-		}
 		if (a->data.non_resident.lowest_vcn) {
 			ntfs_error(vi->i_sb, "First extent of attribute has "
 					"non-zero lowest_vcn.");
 			goto unm_err_out;
 		}
-		/* Setup all the sizes. */
 		vi->i_size = sle64_to_cpu(a->data.non_resident.data_size);
 		ni->initialized_size = sle64_to_cpu(
 				a->data.non_resident.initialized_size);
 		ni->allocated_size = sle64_to_cpu(
 				a->data.non_resident.allocated_size);
-		if (NInoCompressed(ni))
-			ni->itype.compressed.size = sle64_to_cpu(
-					a->data.non_resident.compressed_size);
 	}
-
 	/* Setup the operations for this attribute inode. */
 	vi->i_op = NULL;
 	vi->i_fop = NULL;
@@ -1353,12 +1349,10 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 		vi->i_mapping->a_ops = &ntfs_mst_aops;
 	else
 		vi->i_mapping->a_ops = &ntfs_aops;
-
-	if (!NInoCompressed(ni))
-		vi->i_blocks = ni->allocated_size >> 9;
-	else
+	if (NInoCompressed(ni) || NInoSparse(ni))
 		vi->i_blocks = ni->itype.compressed.size >> 9;
-
+	else
+		vi->i_blocks = ni->allocated_size >> 9;
 	/*
 	 * Make sure the base inode doesn't go away and attach it to the
 	 * attribute inode.
@@ -1643,7 +1637,6 @@ skip_large_index_stuff:
 	vi->i_fop = NULL;
 	vi->i_mapping->a_ops = &ntfs_mst_aops;
 	vi->i_blocks = ni->allocated_size >> 9;
-
 	/*
 	 * Make sure the base inode doesn't go away and attach it to the
 	 * index inode.
@@ -1728,7 +1721,6 @@ int ntfs_read_inode_mount(struct inode *vi)
 	ni->type = AT_DATA;
 	ni->name = NULL;
 	ni->name_len = 0;
-
 	/*
 	 * This sets up our little cheat allowing us to reuse the async read io
 	 * completion handler for directories.

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;