NTFS: Fix comparison of $MFT and $MFTMirr to not bail out when there are

      unused, invalid mft records which are the same in both $MFT and
      $MFTMirr.

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

2 files changed, 28 insertions, 13 deletions

diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
index 8df10700a930..548d9059a697 100644
--- a/fs/ntfs/ChangeLog
+++ b/fs/ntfs/ChangeLog
@@ -28,6 +28,9 @@ ToDo/Notes:
           continued the attribute lookup loop instead of aborting it.
         - Use buffer_migrate_page() for the ->migratepage function of all ntfs
           address space operations.
+        - Fix comparison of $MFT and $MFTMirr to not bail out when there are
+          unused, invalid mft records which are the same in both $MFT and
+          $MFTMirr.
 
 2.1.26 - Minor bug fixes and updates.
 
diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
index 71c58eca580e..fd4aecc5548e 100644
--- a/fs/ntfs/super.c
+++ b/fs/ntfs/super.c
@@ -1099,26 +1099,38 @@ static BOOL check_mft_mirror(ntfs_volume *vol)
                         kmirr = page_address(mirr_page);
                         ++index;
                 }
-                /* Make sure the record is ok. */
-                if (ntfs_is_baad_recordp((le32*)kmft)) {
-                        ntfs_error(sb, "Incomplete multi sector transfer "
-                                        "detected in mft record %i.", i);
+                /* Do not check the record if it is not in use. */
+                if (((MFT_RECORD*)kmft)->flags & MFT_RECORD_IN_USE) {
+                        /* Make sure the record is ok. */
+                        if (ntfs_is_baad_recordp((le32*)kmft)) {
+                                ntfs_error(sb, "Incomplete multi sector "
+                                                "transfer detected in mft "
+                                                "record %i.", i);
 mm_unmap_out:
-                        ntfs_unmap_page(mirr_page);
+                                ntfs_unmap_page(mirr_page);
 mft_unmap_out:
-                        ntfs_unmap_page(mft_page);
-                        return FALSE;
+                                ntfs_unmap_page(mft_page);
+                                return FALSE;
+                        }
                 }
-                if (ntfs_is_baad_recordp((le32*)kmirr)) {
-                        ntfs_error(sb, "Incomplete multi sector transfer "
-                                        "detected in mft mirror record %i.", i);
-                        goto mm_unmap_out;
+                /* Do not check the mirror record if it is not in use. */
+                if (((MFT_RECORD*)kmirr)->flags & MFT_RECORD_IN_USE) {
+                        if (ntfs_is_baad_recordp((le32*)kmirr)) {
+                                ntfs_error(sb, "Incomplete multi sector "
+                                                "transfer detected in mft "
+                                                "mirror record %i.", i);
+                                goto mm_unmap_out;
+                        }
                 }
                 /* Get the amount of data in the current record. */
                 bytes = le32_to_cpu(((MFT_RECORD*)kmft)->bytes_in_use);
-                if (!bytes || bytes > vol->mft_record_size) {
+                if (bytes < sizeof(MFT_RECORD_OLD) ||
+                                bytes > vol->mft_record_size ||
+                                ntfs_is_baad_recordp((le32*)kmft)) {
                         bytes = le32_to_cpu(((MFT_RECORD*)kmirr)->bytes_in_use);
-                        if (!bytes || bytes > vol->mft_record_size)
+                        if (bytes < sizeof(MFT_RECORD_OLD) ||
+                                        bytes > vol->mft_record_size ||
+                                        ntfs_is_baad_recordp((le32*)kmirr))
                                 bytes = vol->mft_record_size;
                 }
                 /* Compare the two records. */