| 1 | /*
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| 2 | * alloc.c --- allocate new inodes, blocks for ext2fs
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| 3 | *
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| 4 | * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
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| 5 | *
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| 6 | * %Begin-Header%
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| 7 | * This file may be redistributed under the terms of the GNU Public
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| 8 | * License.
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| 9 | * %End-Header%
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| 10 | *
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| 11 | */
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| 12 |
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| 13 | #include <stdio.h>
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| 14 | #if HAVE_UNISTD_H
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| 15 | #include <unistd.h>
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| 16 | #endif
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| 17 | #include <time.h>
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| 18 | #include <string.h>
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| 19 | #if HAVE_SYS_STAT_H
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| 20 | #include <sys/stat.h>
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| 21 | #endif
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| 22 | #if HAVE_SYS_TYPES_H
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| 23 | #include <sys/types.h>
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| 24 | #endif
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| 25 |
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| 26 | #include "ext2_fs.h"
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| 27 | #include "ext2fs.h"
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| 28 |
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| 29 | /*
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| 30 | * Right now, just search forward from the parent directory's block
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| 31 | * group to find the next free inode.
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| 32 | *
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| 33 | * Should have a special policy for directories.
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| 34 | */
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| 35 | errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir,
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| 36 | int mode EXT2FS_ATTR((unused)),
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| 37 | ext2fs_inode_bitmap map, ext2_ino_t *ret)
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| 38 | {
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| 39 | ext2_ino_t dir_group = 0;
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| 40 | ext2_ino_t i;
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| 41 | ext2_ino_t start_inode;
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| 42 |
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| 43 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
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| 44 |
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| 45 | if (!map)
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| 46 | map = fs->inode_map;
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| 47 | if (!map)
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| 48 | return EXT2_ET_NO_INODE_BITMAP;
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| 49 |
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| 50 | if (dir > 0)
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| 51 | dir_group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super);
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| 52 |
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| 53 | start_inode = (dir_group * EXT2_INODES_PER_GROUP(fs->super)) + 1;
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| 54 | if (start_inode < EXT2_FIRST_INODE(fs->super))
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| 55 | start_inode = EXT2_FIRST_INODE(fs->super);
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| 56 | i = start_inode;
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| 57 |
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| 58 | do {
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| 59 | if (!ext2fs_fast_test_inode_bitmap(map, i))
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| 60 | break;
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| 61 | i++;
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| 62 | if (i > fs->super->s_inodes_count)
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| 63 | i = EXT2_FIRST_INODE(fs->super);
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| 64 | } while (i != start_inode);
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| 65 |
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| 66 | if (ext2fs_test_inode_bitmap(map, i))
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| 67 | return EXT2_ET_INODE_ALLOC_FAIL;
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| 68 | *ret = i;
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| 69 | return 0;
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| 70 | }
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| 71 |
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| 72 | /*
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| 73 | * Stupid algorithm --- we now just search forward starting from the
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| 74 | * goal. Should put in a smarter one someday....
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| 75 | */
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| 76 | errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal,
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| 77 | ext2fs_block_bitmap map, blk_t *ret)
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| 78 | {
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| 79 | blk_t i;
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| 80 |
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| 81 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
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| 82 |
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| 83 | if (!map)
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| 84 | map = fs->block_map;
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| 85 | if (!map)
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| 86 | return EXT2_ET_NO_BLOCK_BITMAP;
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| 87 | if (!goal || (goal >= fs->super->s_blocks_count))
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| 88 | goal = fs->super->s_first_data_block;
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| 89 | i = goal;
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| 90 | do {
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| 91 | if (!ext2fs_fast_test_block_bitmap(map, i)) {
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| 92 | *ret = i;
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| 93 | return 0;
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| 94 | }
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| 95 | i++;
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| 96 | if (i >= fs->super->s_blocks_count)
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| 97 | i = fs->super->s_first_data_block;
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| 98 | } while (i != goal);
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| 99 | return EXT2_ET_BLOCK_ALLOC_FAIL;
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| 100 | }
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| 101 |
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| 102 | /*
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| 103 | * This function zeros out the allocated block, and updates all of the
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| 104 | * appropriate filesystem records.
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| 105 | */
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| 106 | errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
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| 107 | char *block_buf, blk_t *ret)
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| 108 | {
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| 109 | errcode_t retval;
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| 110 | blk_t block;
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| 111 | char *buf = 0;
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| 112 |
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| 113 | if (!block_buf) {
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| 114 | retval = ext2fs_get_mem(fs->blocksize, &buf);
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| 115 | if (retval)
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| 116 | return retval;
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| 117 | block_buf = buf;
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| 118 | }
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| 119 | memset(block_buf, 0, fs->blocksize);
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| 120 |
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| 121 | if (!fs->block_map) {
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| 122 | retval = ext2fs_read_block_bitmap(fs);
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| 123 | if (retval)
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| 124 | goto fail;
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| 125 | }
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| 126 |
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| 127 | retval = ext2fs_new_block(fs, goal, 0, &block);
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| 128 | if (retval)
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| 129 | goto fail;
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| 130 |
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| 131 | retval = io_channel_write_blk(fs->io, block, 1, block_buf);
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| 132 | if (retval)
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| 133 | goto fail;
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| 134 |
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| 135 | ext2fs_block_alloc_stats(fs, block, +1);
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| 136 | *ret = block;
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| 137 | return 0;
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| 138 |
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| 139 | fail:
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| 140 | if (buf)
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| 141 | ext2fs_free_mem(&buf);
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| 142 | return retval;
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| 143 | }
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| 144 |
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| 145 | errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish,
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| 146 | int num, ext2fs_block_bitmap map, blk_t *ret)
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| 147 | {
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| 148 | blk_t b = start;
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| 149 |
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| 150 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
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| 151 |
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| 152 | if (!map)
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| 153 | map = fs->block_map;
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| 154 | if (!map)
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| 155 | return EXT2_ET_NO_BLOCK_BITMAP;
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| 156 | if (!b)
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| 157 | b = fs->super->s_first_data_block;
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| 158 | if (!finish)
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| 159 | finish = start;
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| 160 | if (!num)
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| 161 | num = 1;
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| 162 | do {
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| 163 | if (b+num-1 > fs->super->s_blocks_count)
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| 164 | b = fs->super->s_first_data_block;
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| 165 | if (ext2fs_fast_test_block_bitmap_range(map, b, num)) {
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| 166 | *ret = b;
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| 167 | return 0;
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| 168 | }
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| 169 | b++;
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| 170 | } while (b != finish);
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| 171 | return EXT2_ET_BLOCK_ALLOC_FAIL;
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| 172 | }
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| 173 |
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