NTFS: Fix handling of sparse attributes in ntfs_attr_make_non_resident().

      Also, add BUG() checks to ntfs_attr_make_non_resident() and
      ntfs_attr_set() to ensure that these functions are never called
      for compressed or encrypted attributes.

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

1 files changed, 36 insertions, 17 deletions

diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index 98b5b96e8397..3f9a4ff42ee5 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -1372,6 +1372,12 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni)
                 return err;
         }
         /*
+         * FIXME: Compressed and encrypted attributes are not supported when
+         * writing and we should never have gotten here for them.
+         */
+        BUG_ON(NInoCompressed(ni));
+        BUG_ON(NInoEncrypted(ni));
+        /*
          * The size needs to be aligned to a cluster boundary for allocation
          * purposes.
          */
@@ -1447,10 +1453,15 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni)
         BUG_ON(a->non_resident);
         /*
          * Calculate new offsets for the name and the mapping pairs array.
-         * We assume the attribute is not compressed or sparse.
          */
-        name_ofs = (offsetof(ATTR_REC,
-                        data.non_resident.compressed_size) + 7) & ~7;
+        if (NInoSparse(ni) || NInoCompressed(ni))
+                name_ofs = (offsetof(ATTR_REC,
+                                data.non_resident.compressed_size) +
+                                sizeof(a->data.non_resident.compressed_size) +
+                                7) & ~7;
+        else
+                name_ofs = (offsetof(ATTR_REC,
+                                data.non_resident.compressed_size) + 7) & ~7;
         mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7;
         /*
          * Determine the size of the resident part of the now non-resident
@@ -1489,24 +1500,23 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni)
                 memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset),
                                 a->name_length * sizeof(ntfschar));
         a->name_offset = cpu_to_le16(name_ofs);
-        /*
-         * FIXME: For now just clear all of these as we do not support them
-         * when writing.
-         */
-        a->flags &= cpu_to_le16(0xffff & ~le16_to_cpu(ATTR_IS_SPARSE |
-                        ATTR_IS_ENCRYPTED | ATTR_COMPRESSION_MASK));
         /* Setup the fields specific to non-resident attributes. */
         a->data.non_resident.lowest_vcn = 0;
         a->data.non_resident.highest_vcn = cpu_to_sle64((new_size - 1) >>
                         vol->cluster_size_bits);
         a->data.non_resident.mapping_pairs_offset = cpu_to_le16(mp_ofs);
-        a->data.non_resident.compression_unit = 0;
         memset(&a->data.non_resident.reserved, 0,
                         sizeof(a->data.non_resident.reserved));
         a->data.non_resident.allocated_size = cpu_to_sle64(new_size);
         a->data.non_resident.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.compressed_size =
+                                a->data.non_resident.allocated_size;
+        } else
+                a->data.non_resident.compression_unit = 0;
         /* Generate the mapping pairs array into the attribute record. */
         err = ntfs_mapping_pairs_build(vol, (u8*)a + mp_ofs,
                         arec_size - mp_ofs, rl, 0, -1, NULL);
@@ -1516,16 +1526,19 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni)
                 goto undo_err_out;
         }
         /* Setup the in-memory attribute structure to be non-resident. */
-        /*
-         * FIXME: For now just clear all of these as we do not support them
-         * when writing.
-         */
-        NInoClearSparse(ni);
-        NInoClearEncrypted(ni);
-        NInoClearCompressed(ni);
         ni->runlist.rl = rl;
         write_lock_irqsave(&ni->size_lock, flags);
         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;
+        }
         write_unlock_irqrestore(&ni->size_lock, flags);
         /*
          * This needs to be last since the address space operations ->readpage
@@ -1673,6 +1686,12 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
         BUG_ON(cnt < 0);
         if (!cnt)
                 goto done;
+        /*
+         * FIXME: Compressed and encrypted attributes are not supported when
+         * writing and we should never have gotten here for them.
+         */
+        BUG_ON(NInoCompressed(ni));
+        BUG_ON(NInoEncrypted(ni));
         mapping = VFS_I(ni)->i_mapping;
         /* Work out the starting index and page offset. */
         idx = ofs >> PAGE_CACHE_SHIFT;