NTFS: Fixup handling of sparse, compressed, and encrypted attributes in

      fs/ntfs/aops.c::ntfs_readpage().

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

1 files changed, 24 insertions, 17 deletions

diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index 59389a8801bc..2482b677a82a 100644
--- a/fs/ntfs/aops.c
+++ b/fs/ntfs/aops.c
@@ -379,31 +379,38 @@ retry_readpage:
                 return 0;
         }
         ni = NTFS_I(page->mapping->host);
-
+        /*
+         * Only $DATA attributes can be encrypted and only unnamed $DATA
+         * attributes can be compressed.  Index root can have the flags set but
+         * this means to create compressed/encrypted files, not that the
+         * attribute is compressed/encrypted.
+         */
+        if (ni->type != AT_INDEX_ROOT) {
+                /* If attribute is encrypted, deny access, just like NT4. */
+                if (NInoEncrypted(ni)) {
+                        BUG_ON(ni->type != AT_DATA);
+                        err = -EACCES;
+                        goto err_out;
+                }
+                /* Compressed data streams are handled in compress.c. */
+                if (NInoNonResident(ni) && NInoCompressed(ni)) {
+                        BUG_ON(ni->type != AT_DATA);
+                        BUG_ON(ni->name_len);
+                        return ntfs_read_compressed_block(page);
+                }
+        }
         /* NInoNonResident() == NInoIndexAllocPresent() */
         if (NInoNonResident(ni)) {
-                /*
-                 * Only unnamed $DATA attributes can be compressed or
-                 * encrypted.
-                 */
-                if (ni->type == AT_DATA && !ni->name_len) {
-                        /* If file is encrypted, deny access, just like NT4. */
-                        if (NInoEncrypted(ni)) {
-                                err = -EACCES;
-                                goto err_out;
-                        }
-                        /* Compressed data streams are handled in compress.c. */
-                        if (NInoCompressed(ni))
-                                return ntfs_read_compressed_block(page);
-                }
-                /* Normal data stream. */
+                /* Normal, non-resident data stream. */
                 return ntfs_read_block(page);
         }
         /*
          * Attribute is resident, implying it is not compressed or encrypted.
          * This also means the attribute is smaller than an mft record and
          * hence smaller than a page, so can simply zero out any pages with
-         * index above 0.
+         * index above 0.  Note the attribute can actually be marked compressed
+         * but if it is resident the actual data is not compressed so we are
+         * ok to ignore the compressed flag here.
          */
         if (unlikely(page->index > 0)) {
                 kaddr = kmap_atomic(page, KM_USER0);