core/fs/xfs/xfs_dinode.c

   1 /*
   2  * Copyright (c) 2012-2013 Paulo Alcantara <pcacjr@zytor.com>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write the Free Software Foundation,
  15  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  16  */
  17
  18 #include <cache.h>
  19 #include <core.h>
  20 #include <fs.h>
  21
  22 #include "xfs_types.h"
  23 #include "xfs_sb.h"
  24 #include "xfs_ag.h"
  25 #include "misc.h"
  26 #include "xfs.h"
  27
  28 #include "xfs_dinode.h"
  29
  30 xfs_dinode_t *xfs_dinode_get_core(struct fs_info *fs, xfs_ino_t ino)
  31 {
  32     block_t blk;
  33     xfs_dinode_t *core;
  34     uint64_t offset;
  35
  36     xfs_debug("fs %p ino %lu", fs, ino);
  37
  38     blk = ino_to_bytes(fs, ino) >> BLOCK_SHIFT(fs);
  39     offset = XFS_INO_TO_OFFSET(XFS_INFO(fs), ino) << XFS_INFO(fs)->inode_shift;
  40     if (offset > BLOCK_SIZE(fs)) {
  41         xfs_error("Invalid inode offset in block!");
  42         xfs_debug("offset: 0x%llx", offset);
  43         goto out;
  44     }
  45
  46     xfs_debug("blk %llu block offset 0x%llx", blk, blk << BLOCK_SHIFT(fs));
  47     xfs_debug("inode offset in block (in bytes) is 0x%llx", offset);
  48
  49     core = (xfs_dinode_t *)((uint8_t *)get_cache(fs->fs_dev, blk) + offset);
  50     if (be16_to_cpu(core->di_magic) !=
  51         be16_to_cpu(*(uint16_t *)XFS_DINODE_MAGIC)) {
  52         xfs_error("Inode core's magic number does not match!");
  53         xfs_debug("magic number 0x%04x", (be16_to_cpu(core->di_magic)));
  54         goto out;
  55     }
  56
  57     return core;
  58
  59 out:
  60     return NULL;
  61 }