ocfs2: Checksum and ECC for directory blocks.

Use the db_check field of ocfs2_dir_block_trailer to crc/ecc the
dirblocks.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 35 insertions, 2 deletions

diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index 1efd0ab680cf..f2c4098cf337 100644
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -48,6 +48,7 @@
 #include "ocfs2.h"
 
 #include "alloc.h"
+#include "blockcheck.h"
 #include "dir.h"
 #include "dlmglue.h"
 #include "extent_map.h"
@@ -107,6 +108,17 @@ static inline unsigned int ocfs2_dir_trailer_blk_off(struct super_block *sb)
 
 #define ocfs2_trailer_from_bh(_bh, _sb) ((struct ocfs2_dir_block_trailer *) ((_bh)->b_data + ocfs2_dir_trailer_blk_off((_sb))))
 
+/* XXX ocfs2_block_dqtrailer() is similar but not quite - can we make
+ * them more consistent? */
+struct ocfs2_dir_block_trailer *ocfs2_dir_trailer_from_size(int blocksize,
+                                                            void *data)
+{
+        char *p = data;
+
+        p += blocksize - sizeof(struct ocfs2_dir_block_trailer);
+        return (struct ocfs2_dir_block_trailer *)p;
+}
+
 /*
  * XXX: This is executed once on every dirent. We should consider optimizing
  * it.
@@ -268,14 +280,35 @@ out:
 static int ocfs2_validate_dir_block(struct super_block *sb,
                                     struct buffer_head *bh)
 {
+        int rc;
+        struct ocfs2_dir_block_trailer *trailer =
+                ocfs2_trailer_from_bh(bh, sb);
+
+
         /*
-         * Nothing yet.  We don't validate dirents here, that's handled
+         * We don't validate dirents here, that's handled
          * in-place when the code walks them.
          */
         mlog(0, "Validating dirblock %llu\n",
              (unsigned long long)bh->b_blocknr);
 
-        return 0;
+        BUG_ON(!buffer_uptodate(bh));
+
+        /*
+         * If the ecc fails, we return the error but otherwise
+         * leave the filesystem running.  We know any error is
+         * local to this block.
+         *
+         * Note that we are safe to call this even if the directory
+         * doesn't have a trailer.  Filesystems without metaecc will do
+         * nothing, and filesystems with it will have one.
+         */
+        rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &trailer->db_check);
+        if (rc)
+                mlog(ML_ERROR, "Checksum failed for dinode %llu\n",
+                     (unsigned long long)bh->b_blocknr);
+
+        return rc;
 }
 
 /*