Theodore Ts'o | 3839e65 | 1997-04-26 13:21:57 +0000 | [diff] [blame] | 1 | /* |
| 2 | * block.c --- iterate over all blocks in an inode |
| 3 | * |
| 4 | * Copyright (C) 1993 Theodore Ts'o. This file may be redistributed |
| 5 | * under the terms of the GNU Public License. |
| 6 | */ |
| 7 | |
| 8 | #include <stdio.h> |
| 9 | #include <string.h> |
| 10 | #include <unistd.h> |
| 11 | #include <stdlib.h> |
Theodore Ts'o | f3db356 | 1997-04-26 13:34:30 +0000 | [diff] [blame^] | 12 | |
Theodore Ts'o | 3839e65 | 1997-04-26 13:21:57 +0000 | [diff] [blame] | 13 | #include <linux/ext2_fs.h> |
| 14 | |
| 15 | #include "ext2fs.h" |
| 16 | |
| 17 | struct block_context { |
| 18 | ext2_filsys fs; |
| 19 | int (*func)(ext2_filsys fs, |
| 20 | blk_t *blocknr, |
| 21 | int bcount, |
| 22 | void *private); |
| 23 | int bcount; |
| 24 | int bsize; |
| 25 | int flags; |
| 26 | errcode_t errcode; |
| 27 | char *ind_buf; |
| 28 | char *dind_buf; |
| 29 | char *tind_buf; |
| 30 | void *private; |
| 31 | }; |
| 32 | |
| 33 | static int block_iterate_ind(blk_t *ind_block, struct block_context *ctx) |
| 34 | { |
| 35 | int ret = 0, changed = 0; |
| 36 | int i, flags; |
| 37 | blk_t *block_nr; |
| 38 | |
| 39 | if (!(ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE)) |
| 40 | ret = (*ctx->func)(ctx->fs, ind_block, -1, ctx->private); |
| 41 | if (!*ind_block || (ret & BLOCK_ABORT)) |
| 42 | return ret; |
Theodore Ts'o | f3db356 | 1997-04-26 13:34:30 +0000 | [diff] [blame^] | 43 | if (*ind_block >= ctx->fs->super->s_blocks_count || |
| 44 | *ind_block < ctx->fs->super->s_first_data_block) { |
| 45 | ctx->errcode = EXT2_ET_BAD_IND_BLOCK; |
| 46 | ret |= BLOCK_ERROR; |
| 47 | return ret; |
| 48 | } |
Theodore Ts'o | 3839e65 | 1997-04-26 13:21:57 +0000 | [diff] [blame] | 49 | ctx->errcode = io_channel_read_blk(ctx->fs->io, *ind_block, |
| 50 | 1, ctx->ind_buf); |
| 51 | if (ctx->errcode) { |
| 52 | ret |= BLOCK_ERROR; |
| 53 | return ret; |
| 54 | } |
| 55 | for (i = 0; i < (ctx->fs->blocksize >> 2); i++, ctx->bcount++) { |
| 56 | block_nr = (blk_t *) ctx->ind_buf + i; |
| 57 | if (*block_nr || (ctx->flags & BLOCK_FLAG_APPEND)) { |
| 58 | flags = (*ctx->func)(ctx->fs, block_nr, ctx->bcount, |
| 59 | ctx->private); |
| 60 | changed |= flags & BLOCK_CHANGED; |
| 61 | if (flags & BLOCK_ABORT) { |
| 62 | ret |= BLOCK_ABORT; |
| 63 | break; |
| 64 | } |
| 65 | } |
| 66 | } |
| 67 | if (changed) { |
| 68 | ctx->errcode = io_channel_write_blk(ctx->fs->io, *ind_block, |
| 69 | 1, ctx->ind_buf); |
| 70 | if (ctx->errcode) |
| 71 | ret |= BLOCK_ERROR | BLOCK_ABORT; |
| 72 | } |
| 73 | if ((ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE) && |
| 74 | !(ret & BLOCK_ABORT)) |
| 75 | ret |= (*ctx->func)(ctx->fs, ind_block, -1, ctx->private); |
| 76 | return ret; |
| 77 | } |
| 78 | |
| 79 | static int block_iterate_dind(blk_t *dind_block, struct block_context *ctx) |
| 80 | { |
| 81 | int ret = 0, changed = 0; |
| 82 | int i, flags; |
| 83 | blk_t *block_nr; |
| 84 | |
| 85 | if (!(ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE)) |
| 86 | ret = (*ctx->func)(ctx->fs, dind_block, -2, ctx->private); |
| 87 | if (!*dind_block || (ret & BLOCK_ABORT)) |
| 88 | return ret; |
Theodore Ts'o | f3db356 | 1997-04-26 13:34:30 +0000 | [diff] [blame^] | 89 | if (*dind_block >= ctx->fs->super->s_blocks_count || |
| 90 | *dind_block < ctx->fs->super->s_first_data_block) { |
| 91 | ctx->errcode = EXT2_ET_BAD_DIND_BLOCK; |
| 92 | ret |= BLOCK_ERROR; |
| 93 | return ret; |
| 94 | } |
Theodore Ts'o | 3839e65 | 1997-04-26 13:21:57 +0000 | [diff] [blame] | 95 | ctx->errcode = io_channel_read_blk(ctx->fs->io, *dind_block, |
| 96 | 1, ctx->dind_buf); |
| 97 | if (ctx->errcode) { |
| 98 | ret |= BLOCK_ERROR; |
| 99 | return ret; |
| 100 | } |
| 101 | for (i = 0; i < (ctx->fs->blocksize >> 2); i++) { |
| 102 | block_nr = (blk_t *) ctx->dind_buf + i; |
| 103 | if (*block_nr || (ctx->flags & BLOCK_FLAG_APPEND)) { |
| 104 | flags = block_iterate_ind(block_nr, ctx); |
| 105 | changed |= flags & BLOCK_CHANGED; |
| 106 | if (flags & (BLOCK_ABORT | BLOCK_ERROR)) { |
| 107 | ret |= flags & (BLOCK_ABORT | BLOCK_ERROR); |
| 108 | break; |
| 109 | } |
| 110 | } |
| 111 | } |
| 112 | if (changed) { |
| 113 | ctx->errcode = io_channel_write_blk(ctx->fs->io, *dind_block, |
| 114 | 1, ctx->dind_buf); |
| 115 | if (ctx->errcode) |
| 116 | ret |= BLOCK_ERROR | BLOCK_ABORT; |
| 117 | } |
| 118 | if ((ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE) && |
| 119 | !(ret & BLOCK_ABORT)) |
| 120 | ret |= (*ctx->func)(ctx->fs, dind_block, -2, ctx->private); |
| 121 | return ret; |
| 122 | } |
| 123 | |
| 124 | static int block_iterate_tind(blk_t *tind_block, struct block_context *ctx) |
| 125 | { |
| 126 | int ret = 0, changed = 0; |
| 127 | int i, flags; |
| 128 | blk_t *block_nr; |
| 129 | |
| 130 | if (!(ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE)) |
| 131 | ret = (*ctx->func)(ctx->fs, tind_block, -3, ctx->private); |
| 132 | if (!*tind_block || (ret & BLOCK_ABORT)) |
| 133 | return ret; |
Theodore Ts'o | f3db356 | 1997-04-26 13:34:30 +0000 | [diff] [blame^] | 134 | if (*tind_block >= ctx->fs->super->s_blocks_count || |
| 135 | *tind_block < ctx->fs->super->s_first_data_block) { |
| 136 | ctx->errcode = EXT2_ET_BAD_TIND_BLOCK; |
| 137 | ret |= BLOCK_ERROR; |
| 138 | return ret; |
| 139 | } |
Theodore Ts'o | 3839e65 | 1997-04-26 13:21:57 +0000 | [diff] [blame] | 140 | ctx->errcode = io_channel_read_blk(ctx->fs->io, *tind_block, |
| 141 | 1, ctx->tind_buf); |
| 142 | if (ctx->errcode) { |
| 143 | ret |= BLOCK_ERROR; |
| 144 | return ret; |
| 145 | } |
| 146 | for (i = 0; i < (ctx->fs->blocksize >> 2); i++) { |
| 147 | block_nr = (blk_t *) ctx->tind_buf + i; |
| 148 | if (*block_nr || (ctx->flags & BLOCK_FLAG_APPEND)) { |
| 149 | flags = block_iterate_dind(block_nr, ctx); |
| 150 | if (flags & (BLOCK_ABORT | BLOCK_ERROR)) { |
| 151 | ret |= flags & (BLOCK_ABORT | BLOCK_ERROR); |
| 152 | break; |
| 153 | } |
| 154 | } |
| 155 | } |
| 156 | if (changed) { |
| 157 | ctx->errcode = io_channel_write_blk(ctx->fs->io, *tind_block, |
| 158 | 1, ctx->tind_buf); |
| 159 | if (ctx->errcode) |
| 160 | ret |= BLOCK_ERROR | BLOCK_ABORT; |
| 161 | } |
| 162 | if ((ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE) && |
| 163 | !(ret & BLOCK_ABORT)) |
| 164 | ret |= (*ctx->func)(ctx->fs, tind_block, -3, ctx->private); |
| 165 | |
| 166 | return ret; |
| 167 | } |
| 168 | |
| 169 | errcode_t ext2fs_block_iterate(ext2_filsys fs, |
| 170 | ino_t ino, |
| 171 | int flags, |
| 172 | char *block_buf, |
| 173 | int (*func)(ext2_filsys fs, |
| 174 | blk_t *blocknr, |
| 175 | int blockcnt, |
| 176 | void *private), |
| 177 | void *private) |
| 178 | { |
| 179 | int i; |
| 180 | int ret = 0; |
| 181 | struct block_context ctx; |
| 182 | blk_t blocks[EXT2_N_BLOCKS]; /* directory data blocks */ |
| 183 | struct ext2_inode inode; |
| 184 | errcode_t retval; |
| 185 | |
Theodore Ts'o | f3db356 | 1997-04-26 13:34:30 +0000 | [diff] [blame^] | 186 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
| 187 | |
Theodore Ts'o | 3839e65 | 1997-04-26 13:21:57 +0000 | [diff] [blame] | 188 | ret = ext2fs_get_blocks(fs, ino, blocks); |
| 189 | if (ret) |
| 190 | return ret; |
| 191 | |
| 192 | ctx.fs = fs; |
| 193 | ctx.func = func; |
| 194 | ctx.private = private; |
| 195 | ctx.bcount = 0; |
| 196 | ctx.flags = flags; |
| 197 | if (block_buf) { |
| 198 | ctx.ind_buf = block_buf; |
| 199 | } else { |
| 200 | ctx.ind_buf = malloc(fs->blocksize * 3); |
| 201 | if (!ctx.ind_buf) |
| 202 | return ENOMEM; |
| 203 | } |
| 204 | ctx.dind_buf = ctx.ind_buf + fs->blocksize; |
| 205 | ctx.tind_buf = ctx.dind_buf + fs->blocksize; |
| 206 | |
| 207 | for (i = 0; i < EXT2_NDIR_BLOCKS ; i++, ctx.bcount++) { |
| 208 | if (blocks[i] || (flags & BLOCK_FLAG_APPEND)) { |
| 209 | ret |= (*func)(fs, &blocks[i], ctx.bcount, private); |
| 210 | if (ret & BLOCK_ABORT) |
| 211 | goto abort; |
| 212 | } |
| 213 | } |
| 214 | if (*(blocks + EXT2_IND_BLOCK) || (flags & BLOCK_FLAG_APPEND)) { |
| 215 | ret |= block_iterate_ind(blocks + EXT2_IND_BLOCK, &ctx); |
| 216 | if (ret & BLOCK_ABORT) |
| 217 | goto abort; |
| 218 | } |
| 219 | if (*(blocks + EXT2_DIND_BLOCK) || (flags & BLOCK_FLAG_APPEND)) { |
| 220 | ret |= block_iterate_dind(blocks + EXT2_DIND_BLOCK, &ctx); |
| 221 | if (ret & BLOCK_ABORT) |
| 222 | goto abort; |
| 223 | } |
| 224 | if (*(blocks + EXT2_TIND_BLOCK) || (flags & BLOCK_FLAG_APPEND)) |
| 225 | ret |= block_iterate_tind(blocks + EXT2_TIND_BLOCK, &ctx); |
| 226 | |
| 227 | abort: |
| 228 | if (ret & BLOCK_CHANGED) { |
| 229 | retval = ext2fs_read_inode(fs, ino, &inode); |
| 230 | if (retval) |
| 231 | return retval; |
| 232 | for (i=0; i < EXT2_N_BLOCKS; i++) |
| 233 | inode.i_block[i] = blocks[i]; |
| 234 | retval = ext2fs_write_inode(fs, ino, &inode); |
| 235 | if (retval) |
| 236 | return retval; |
| 237 | } |
| 238 | |
| 239 | if (!block_buf) |
| 240 | free(ctx.ind_buf); |
| 241 | |
| 242 | return (ret & BLOCK_ERROR) ? ctx.errcode : 0; |
| 243 | } |