{
        struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
 
-       lock_super(sb);
+       lock_buffer(HFS_SB(sb)->mdb_bh);
        if (test_and_clear_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags)) {
                /* These parameters may have been modified, so write them back */
                mdb->drLsMod = hfs_mtime();
                                     &mdb->drXTFlSize, NULL);
                hfs_inode_write_fork(HFS_SB(sb)->cat_tree->inode, mdb->drCTExtRec,
                                     &mdb->drCTFlSize, NULL);
+
+               lock_buffer(HFS_SB(sb)->alt_mdb_bh);
                memcpy(HFS_SB(sb)->alt_mdb, HFS_SB(sb)->mdb, HFS_SECTOR_SIZE);
                HFS_SB(sb)->alt_mdb->drAtrb |= cpu_to_be16(HFS_SB_ATTRIB_UNMNT);
                HFS_SB(sb)->alt_mdb->drAtrb &= cpu_to_be16(~HFS_SB_ATTRIB_INCNSTNT);
+               unlock_buffer(HFS_SB(sb)->alt_mdb_bh);
+
                mark_buffer_dirty(HFS_SB(sb)->alt_mdb_bh);
                sync_dirty_buffer(HFS_SB(sb)->alt_mdb_bh);
        }
                                break;
                        }
                        len = min((int)sb->s_blocksize - off, size);
+
+                       lock_buffer(bh);
                        memcpy(bh->b_data + off, ptr, len);
+                       unlock_buffer(bh);
+
                        mark_buffer_dirty(bh);
                        brelse(bh);
                        block++;
                        size -= len;
                }
        }
-       unlock_super(sb);
+       unlock_buffer(HFS_SB(sb)->mdb_bh);
 }
 
 void hfs_mdb_close(struct super_block *sb)