git.maemo.org Git - busybox4maemo/blob - e2fsprogs/old_e2fsprogs/ext2fs/ext_attr.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * ext_attr.c --- extended attribute blocks
   4  *
   5  * Copyright (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
   6  *
   7  * Copyright (C) 2002 Theodore Ts'o.
   8  *
   9  * %Begin-Header%
  10  * This file may be redistributed under the terms of the GNU Public
  11  * License.
  12  * %End-Header%
  13  */
  14
  15 #include <stdio.h>
  16 #include <unistd.h>
  17 #include <string.h>
  18 #include <time.h>
  19
  20 #include "ext2_fs.h"
  21 #include "ext2_ext_attr.h"
  22 #include "ext2fs.h"
  23
  24 errcode_t ext2fs_read_ext_attr(ext2_filsys fs, blk_t block, void *buf)
  25 {
  26         errcode_t       retval;
  27
  28         retval = io_channel_read_blk(fs->io, block, 1, buf);
  29         if (retval)
  30                 return retval;
  31 #if BB_BIG_ENDIAN
  32         if ((fs->flags & (EXT2_FLAG_SWAP_BYTES|
  33                           EXT2_FLAG_SWAP_BYTES_READ)) != 0)
  34                 ext2fs_swap_ext_attr(buf, buf, fs->blocksize, 1);
  35 #endif
  36         return 0;
  37 }
  38
  39 errcode_t ext2fs_write_ext_attr(ext2_filsys fs, blk_t block, void *inbuf)
  40 {
  41         errcode_t       retval;
  42         char            *write_buf;
  43         char            *buf = NULL;
  44
  45         if (BB_BIG_ENDIAN && ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
  46             (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))) {
  47                 retval = ext2fs_get_mem(fs->blocksize, &buf);
  48                 if (retval)
  49                         return retval;
  50                 write_buf = buf;
  51                 ext2fs_swap_ext_attr(buf, inbuf, fs->blocksize, 1);
  52         } else
  53                 write_buf = (char *) inbuf;
  54         retval = io_channel_write_blk(fs->io, block, 1, write_buf);
  55         if (buf)
  56                 ext2fs_free_mem(&buf);
  57         if (!retval)
  58                 ext2fs_mark_changed(fs);
  59         return retval;
  60 }
  61
  62 /*
  63  * This function adjusts the reference count of the EA block.
  64  */
  65 errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, blk_t blk,
  66                                     char *block_buf, int adjust,
  67                                     __u32 *newcount)
  68 {
  69         errcode_t       retval;
  70         struct ext2_ext_attr_header *header;
  71         char    *buf = 0;
  72
  73         if ((blk >= fs->super->s_blocks_count) ||
  74             (blk < fs->super->s_first_data_block))
  75                 return EXT2_ET_BAD_EA_BLOCK_NUM;
  76
  77         if (!block_buf) {
  78                 retval = ext2fs_get_mem(fs->blocksize, &buf);
  79                 if (retval)
  80                         return retval;
  81                 block_buf = buf;
  82         }
  83
  84         retval = ext2fs_read_ext_attr(fs, blk, block_buf);
  85         if (retval)
  86                 goto errout;
  87
  88         header = (struct ext2_ext_attr_header *) block_buf;
  89         header->h_refcount += adjust;
  90         if (newcount)
  91                 *newcount = header->h_refcount;
  92
  93         retval = ext2fs_write_ext_attr(fs, blk, block_buf);
  94         if (retval)
  95                 goto errout;
  96
  97 errout:
  98         if (buf)
  99                 ext2fs_free_mem(&buf);
 100         return retval;
 101 }