xfs: validate the realtime geometry in xfs_validate_sb_common
[linux-2.6-block.git] / fs / xfs / libxfs / xfs_sb.c
index 00266de58954e2c769138d3e175d123494c345df..c526c5e5ab76773b40025e5917b64cc34c5cab41 100644 (file)
@@ -328,6 +328,38 @@ xfs_validate_sb_common(
                return -EFSCORRUPTED;
        }
 
+       /* Validate the realtime geometry; stolen from xfs_repair */
+       if (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE ||
+           sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) {
+               xfs_notice(mp,
+                       "realtime extent sanity check failed");
+               return -EFSCORRUPTED;
+       }
+
+       if (sbp->sb_rblocks == 0) {
+               if (sbp->sb_rextents != 0 || sbp->sb_rbmblocks != 0 ||
+                   sbp->sb_rextslog != 0 || sbp->sb_frextents != 0) {
+                       xfs_notice(mp,
+                               "realtime zeroed geometry check failed");
+                       return -EFSCORRUPTED;
+               }
+       } else {
+               uint64_t        rexts;
+               uint64_t        rbmblocks;
+
+               rexts = div_u64(sbp->sb_rblocks, sbp->sb_rextsize);
+               rbmblocks = howmany_64(sbp->sb_rextents,
+                                      NBBY * sbp->sb_blocksize);
+
+               if (sbp->sb_rextents != rexts ||
+                   sbp->sb_rextslog != xfs_highbit32(sbp->sb_rextents) ||
+                   sbp->sb_rbmblocks != rbmblocks) {
+                       xfs_notice(mp,
+                               "realtime geometry sanity check failed");
+                       return -EFSCORRUPTED;
+               }
+       }
+
        if (sbp->sb_unit) {
                if (!xfs_sb_version_hasdalign(sbp) ||
                    sbp->sb_unit > sbp->sb_width ||