Theodore Ts'o | 342d847 | 2001-07-02 11:54:09 -0400 | [diff] [blame] | 1 | /* |
| 2 | * ext_attr.c --- extended attribute blocks |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3 | * |
Theodore Ts'o | 0684a4f | 2002-08-17 10:19:44 -0400 | [diff] [blame] | 4 | * Copyright (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org> |
| 5 | * |
| 6 | * Copyright (C) 2002 Theodore Ts'o. |
Theodore Ts'o | 342d847 | 2001-07-02 11:54:09 -0400 | [diff] [blame] | 7 | * |
| 8 | * %Begin-Header% |
Theodore Ts'o | 543547a | 2010-05-17 21:31:56 -0400 | [diff] [blame] | 9 | * This file may be redistributed under the terms of the GNU Library |
| 10 | * General Public License, version 2. |
Theodore Ts'o | 342d847 | 2001-07-02 11:54:09 -0400 | [diff] [blame] | 11 | * %End-Header% |
| 12 | */ |
| 13 | |
Theodore Ts'o | d1154eb | 2011-09-18 17:34:37 -0400 | [diff] [blame] | 14 | #include "config.h" |
Theodore Ts'o | 342d847 | 2001-07-02 11:54:09 -0400 | [diff] [blame] | 15 | #include <stdio.h> |
| 16 | #if HAVE_UNISTD_H |
| 17 | #include <unistd.h> |
| 18 | #endif |
| 19 | #include <string.h> |
| 20 | #include <time.h> |
| 21 | |
| 22 | #include "ext2_fs.h" |
| 23 | #include "ext2_ext_attr.h" |
| 24 | |
| 25 | #include "ext2fs.h" |
| 26 | |
Andreas Dilger | fefaef3 | 2008-02-02 01:16:32 -0700 | [diff] [blame] | 27 | #define NAME_HASH_SHIFT 5 |
| 28 | #define VALUE_HASH_SHIFT 16 |
| 29 | |
| 30 | /* |
| 31 | * ext2_xattr_hash_entry() |
| 32 | * |
| 33 | * Compute the hash of an extended attribute. |
| 34 | */ |
| 35 | __u32 ext2fs_ext_attr_hash_entry(struct ext2_ext_attr_entry *entry, void *data) |
| 36 | { |
| 37 | __u32 hash = 0; |
| 38 | char *name = ((char *) entry) + sizeof(struct ext2_ext_attr_entry); |
| 39 | int n; |
| 40 | |
| 41 | for (n = 0; n < entry->e_name_len; n++) { |
| 42 | hash = (hash << NAME_HASH_SHIFT) ^ |
| 43 | (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ |
| 44 | *name++; |
| 45 | } |
| 46 | |
| 47 | /* The hash needs to be calculated on the data in little-endian. */ |
| 48 | if (entry->e_value_block == 0 && entry->e_value_size != 0) { |
| 49 | __u32 *value = (__u32 *)data; |
| 50 | for (n = (entry->e_value_size + EXT2_EXT_ATTR_ROUND) >> |
| 51 | EXT2_EXT_ATTR_PAD_BITS; n; n--) { |
| 52 | hash = (hash << VALUE_HASH_SHIFT) ^ |
| 53 | (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ |
| 54 | ext2fs_le32_to_cpu(*value++); |
| 55 | } |
| 56 | } |
| 57 | |
| 58 | return hash; |
| 59 | } |
| 60 | |
| 61 | #undef NAME_HASH_SHIFT |
| 62 | #undef VALUE_HASH_SHIFT |
| 63 | |
Jose R. Santos | b91f14b | 2009-06-01 16:15:40 -0400 | [diff] [blame] | 64 | errcode_t ext2fs_read_ext_attr2(ext2_filsys fs, blk64_t block, void *buf) |
Theodore Ts'o | 342d847 | 2001-07-02 11:54:09 -0400 | [diff] [blame] | 65 | { |
| 66 | errcode_t retval; |
Theodore Ts'o | 342d847 | 2001-07-02 11:54:09 -0400 | [diff] [blame] | 67 | |
Jose R. Santos | b91f14b | 2009-06-01 16:15:40 -0400 | [diff] [blame] | 68 | retval = io_channel_read_blk64(fs->io, block, 1, buf); |
Theodore Ts'o | 342d847 | 2001-07-02 11:54:09 -0400 | [diff] [blame] | 69 | if (retval) |
| 70 | return retval; |
Theodore Ts'o | 126a291 | 2007-08-11 01:56:48 -0400 | [diff] [blame] | 71 | #ifdef WORDS_BIGENDIAN |
| 72 | ext2fs_swap_ext_attr(buf, buf, fs->blocksize, 1); |
Theodore Ts'o | 342d847 | 2001-07-02 11:54:09 -0400 | [diff] [blame] | 73 | #endif |
| 74 | return 0; |
| 75 | } |
| 76 | |
Jose R. Santos | b91f14b | 2009-06-01 16:15:40 -0400 | [diff] [blame] | 77 | errcode_t ext2fs_read_ext_attr(ext2_filsys fs, blk_t block, void *buf) |
| 78 | { |
| 79 | return ext2fs_read_ext_attr2(fs, block, buf); |
| 80 | } |
| 81 | |
| 82 | errcode_t ext2fs_write_ext_attr2(ext2_filsys fs, blk64_t block, void *inbuf) |
Theodore Ts'o | 342d847 | 2001-07-02 11:54:09 -0400 | [diff] [blame] | 83 | { |
| 84 | errcode_t retval; |
Theodore Ts'o | 4ea7bd0 | 2001-12-16 23:23:37 -0500 | [diff] [blame] | 85 | char *write_buf; |
Eric Sandeen | d0f196d | 2011-09-16 15:49:20 -0500 | [diff] [blame] | 86 | #ifdef WORDS_BIGENDIAN |
Theodore Ts'o | 342d847 | 2001-07-02 11:54:09 -0400 | [diff] [blame] | 87 | char *buf = NULL; |
Theodore Ts'o | 342d847 | 2001-07-02 11:54:09 -0400 | [diff] [blame] | 88 | |
Theodore Ts'o | 126a291 | 2007-08-11 01:56:48 -0400 | [diff] [blame] | 89 | retval = ext2fs_get_mem(fs->blocksize, &buf); |
| 90 | if (retval) |
| 91 | return retval; |
| 92 | write_buf = buf; |
| 93 | ext2fs_swap_ext_attr(buf, inbuf, fs->blocksize, 1); |
| 94 | #else |
| 95 | write_buf = (char *) inbuf; |
Theodore Ts'o | 342d847 | 2001-07-02 11:54:09 -0400 | [diff] [blame] | 96 | #endif |
Jose R. Santos | b91f14b | 2009-06-01 16:15:40 -0400 | [diff] [blame] | 97 | retval = io_channel_write_blk64(fs->io, block, 1, write_buf); |
Eric Sandeen | d0f196d | 2011-09-16 15:49:20 -0500 | [diff] [blame] | 98 | #ifdef WORDS_BIGENDIAN |
| 99 | ext2fs_free_mem(&buf); |
| 100 | #endif |
Theodore Ts'o | 241f7d2 | 2001-07-20 14:17:19 -0400 | [diff] [blame] | 101 | if (!retval) |
| 102 | ext2fs_mark_changed(fs); |
Theodore Ts'o | 342d847 | 2001-07-02 11:54:09 -0400 | [diff] [blame] | 103 | return retval; |
| 104 | } |
Theodore Ts'o | 0684a4f | 2002-08-17 10:19:44 -0400 | [diff] [blame] | 105 | |
Jose R. Santos | b91f14b | 2009-06-01 16:15:40 -0400 | [diff] [blame] | 106 | errcode_t ext2fs_write_ext_attr(ext2_filsys fs, blk_t block, void *inbuf) |
| 107 | { |
| 108 | return ext2fs_write_ext_attr2(fs, block, inbuf); |
| 109 | } |
| 110 | |
Theodore Ts'o | 0684a4f | 2002-08-17 10:19:44 -0400 | [diff] [blame] | 111 | /* |
| 112 | * This function adjusts the reference count of the EA block. |
| 113 | */ |
Jose R. Santos | b91f14b | 2009-06-01 16:15:40 -0400 | [diff] [blame] | 114 | errcode_t ext2fs_adjust_ea_refcount2(ext2_filsys fs, blk64_t blk, |
Theodore Ts'o | 0684a4f | 2002-08-17 10:19:44 -0400 | [diff] [blame] | 115 | char *block_buf, int adjust, |
| 116 | __u32 *newcount) |
| 117 | { |
| 118 | errcode_t retval; |
| 119 | struct ext2_ext_attr_header *header; |
| 120 | char *buf = 0; |
| 121 | |
Valerie Aurora Henson | 4efbac6 | 2009-09-07 20:46:34 -0400 | [diff] [blame] | 122 | if ((blk >= ext2fs_blocks_count(fs->super)) || |
Theodore Ts'o | 0684a4f | 2002-08-17 10:19:44 -0400 | [diff] [blame] | 123 | (blk < fs->super->s_first_data_block)) |
| 124 | return EXT2_ET_BAD_EA_BLOCK_NUM; |
| 125 | |
| 126 | if (!block_buf) { |
Theodore Ts'o | c4e3d3f | 2003-08-01 09:41:07 -0400 | [diff] [blame] | 127 | retval = ext2fs_get_mem(fs->blocksize, &buf); |
Theodore Ts'o | 0684a4f | 2002-08-17 10:19:44 -0400 | [diff] [blame] | 128 | if (retval) |
| 129 | return retval; |
| 130 | block_buf = buf; |
| 131 | } |
| 132 | |
Jose R. Santos | b91f14b | 2009-06-01 16:15:40 -0400 | [diff] [blame] | 133 | retval = ext2fs_read_ext_attr2(fs, blk, block_buf); |
Theodore Ts'o | 0684a4f | 2002-08-17 10:19:44 -0400 | [diff] [blame] | 134 | if (retval) |
| 135 | goto errout; |
| 136 | |
| 137 | header = (struct ext2_ext_attr_header *) block_buf; |
| 138 | header->h_refcount += adjust; |
| 139 | if (newcount) |
| 140 | *newcount = header->h_refcount; |
| 141 | |
Jose R. Santos | b91f14b | 2009-06-01 16:15:40 -0400 | [diff] [blame] | 142 | retval = ext2fs_write_ext_attr2(fs, blk, block_buf); |
Theodore Ts'o | 0684a4f | 2002-08-17 10:19:44 -0400 | [diff] [blame] | 143 | if (retval) |
| 144 | goto errout; |
| 145 | |
| 146 | errout: |
| 147 | if (buf) |
Theodore Ts'o | c4e3d3f | 2003-08-01 09:41:07 -0400 | [diff] [blame] | 148 | ext2fs_free_mem(&buf); |
Theodore Ts'o | 0684a4f | 2002-08-17 10:19:44 -0400 | [diff] [blame] | 149 | return retval; |
| 150 | } |
Jose R. Santos | b91f14b | 2009-06-01 16:15:40 -0400 | [diff] [blame] | 151 | |
| 152 | errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, blk_t blk, |
| 153 | char *block_buf, int adjust, |
| 154 | __u32 *newcount) |
| 155 | { |
| 156 | return ext2fs_adjust_ea_refcount(fs, blk, block_buf, adjust, newcount); |
| 157 | } |