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

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

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

diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
index 7f24cb1..c3b5102 100644 (file)
--- a/fs/ntfs/ChangeLog
+++ b/fs/ntfs/ChangeLog
@@ -76,11 +76,10 @@ ToDo/Notes:
        - Truncate {a,c,m}time to the ntfs supported time granularity when
          updating the times in the inode in ntfs_setattr().
        - Fixup handling of sparse, compressed, and encrypted attributes in
-         fs/ntfs/inode.c::ntfs_read_locked_{,attr_,index_}inode().
+         fs/ntfs/inode.c::ntfs_read_locked_{,attr_,index_}inode(),
+         fs/ntfs/aops.c::ntfs_{read,write}page().
        - Make ntfs_write_block() not instantiate sparse blocks if they contain
          only zeroes.
-       - Fixup handling of sparse, compressed, and encrypted attributes in
-         fs/ntfs/aops.c::ntfs_writepage().
        - Optimize fs/ntfs/aops.c::ntfs_write_block() by extending the page
          lock protection over the buffer submission for i/o which allows the
          removal of the get_bh()/put_bh() pairs for each buffer.

diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index 59389a8..2482b67 100644 (file)
--- 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);