blob: a2ba12d45c2e452fec7ae6df8e2adca5122c7bac
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 = NULL; |
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 | } |
102 |