ext_attr.c revision 7331196a16e57ef80dd6ae40eeeab14747ce2f5d 
1/*
2 * ext_attr.c --- extended attribute blocks
3 *
4 * Copyright (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
5 *
6 * Copyright (C) 2002 Theodore Ts'o.
7 *
8 * %Begin-Header%
9 * This file may be redistributed under the terms of the GNU Public
10 * License.
11 * %End-Header%
12 */
13
14#include <stdio.h>
15#if HAVE_UNISTD_H
16#include <unistd.h>
17#endif
18#include <string.h>
19#include <time.h>
20
21#include "ext2_fs.h"
22#include "ext2_ext_attr.h"
23
24#include "ext2fs.h"
25
26errcode_t ext2fs_read_ext_attr(ext2_filsys fs, blk_t block, void *buf)
27{
28	errcode_t	retval;
29
30 	retval = io_channel_read_blk(fs->io, block, 1, buf);
31	if (retval)
32		return retval;
33#ifdef EXT2FS_ENABLE_SWAPFS
34	if ((fs->flags & (EXT2_FLAG_SWAP_BYTES|
35			  EXT2_FLAG_SWAP_BYTES_READ)) != 0)
36		ext2fs_swap_ext_attr(buf, buf, fs->blocksize, 1);
37#endif
38	return 0;
39}
40
41errcode_t ext2fs_write_ext_attr(ext2_filsys fs, blk_t block, void *inbuf)
42{
43	errcode_t	retval;
44	char		*write_buf;
45	char		*buf = NULL;
46
47#ifdef EXT2FS_ENABLE_SWAPFS
48	if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
49	    (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE)) {
50		retval = ext2fs_get_mem(fs->blocksize, &buf);
51		if (retval)
52			return retval;
53		write_buf = buf;
54		ext2fs_swap_ext_attr(buf, inbuf, fs->blocksize, 1);
55	} else
56#endif
57		write_buf = (char *) inbuf;
58 	retval = io_channel_write_blk(fs->io, block, 1, write_buf);
59	if (buf)
60		ext2fs_free_mem(&buf);
61	if (!retval)
62		ext2fs_mark_changed(fs);
63	return retval;
64}
65
66/*
67 * This function adjusts the reference count of the EA block.
68 */
69errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, blk_t blk,
70				    char *block_buf, int adjust,
71				    __u32 *newcount)
72{
73	errcode_t	retval;
74	struct ext2_ext_attr_header *header;
75	char	*buf = 0;
76
77	if ((blk >= fs->super->s_blocks_count) ||
78	    (blk < fs->super->s_first_data_block))
79		return EXT2_ET_BAD_EA_BLOCK_NUM;
80
81	if (!block_buf) {
82		retval = ext2fs_get_mem(fs->blocksize, &buf);
83		if (retval)
84			return retval;
85		block_buf = buf;
86	}
87
88	retval = ext2fs_read_ext_attr(fs, blk, block_buf);
89	if (retval)
90		goto errout;
91
92	header = (struct ext2_ext_attr_header *) block_buf;
93	header->h_refcount += adjust;
94	if (newcount)
95		*newcount = header->h_refcount;
96
97	retval = ext2fs_write_ext_attr(fs, blk, block_buf);
98	if (retval)
99		goto errout;
100
101errout:
102	if (buf)
103		ext2fs_free_mem(&buf);
104	return retval;
105}
106