rw_bitmaps.c revision 5ea3c825929b01739b9b876378c38846aa4b1f13
1/* 2 * rw_bitmaps.c --- routines to read and write the inode and block bitmaps. 3 * 4 * Copyright (C) 1993, 1994, 1994, 1996 Theodore Ts'o. 5 * 6 * %Begin-Header% 7 * This file may be redistributed under the terms of the GNU Library 8 * General Public License, version 2. 9 * %End-Header% 10 */ 11 12#include <stdio.h> 13#include <string.h> 14#if HAVE_UNISTD_H 15#include <unistd.h> 16#endif 17#include <fcntl.h> 18#include <time.h> 19#ifdef HAVE_SYS_STAT_H 20#include <sys/stat.h> 21#endif 22#ifdef HAVE_SYS_TYPES_H 23#include <sys/types.h> 24#endif 25 26#include "ext2_fs.h" 27#include "ext2fs.h" 28#include "e2image.h" 29 30static errcode_t write_bitmaps(ext2_filsys fs, int do_inode, int do_block) 31{ 32 dgrp_t i; 33 unsigned int j; 34 int block_nbytes, inode_nbytes; 35 unsigned int nbits; 36 errcode_t retval; 37 char *block_buf = NULL, *inode_buf = NULL; 38 int csum_flag = 0; 39 blk64_t blk; 40 blk64_t blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block); 41 ext2_ino_t ino_itr = 1; 42 43 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 44 45 if (!(fs->flags & EXT2_FLAG_RW)) 46 return EXT2_ET_RO_FILSYS; 47 48 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 49 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) 50 csum_flag = 1; 51 52 inode_nbytes = block_nbytes = 0; 53 if (do_block) { 54 block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8; 55 retval = ext2fs_get_memalign(fs->blocksize, fs->blocksize, 56 &block_buf); 57 if (retval) 58 goto errout; 59 memset(block_buf, 0xff, fs->blocksize); 60 } 61 if (do_inode) { 62 inode_nbytes = (size_t) 63 ((EXT2_INODES_PER_GROUP(fs->super)+7) / 8); 64 retval = ext2fs_get_memalign(fs->blocksize, fs->blocksize, 65 &inode_buf); 66 if (retval) 67 goto errout; 68 memset(inode_buf, 0xff, fs->blocksize); 69 } 70 71 for (i = 0; i < fs->group_desc_count; i++) { 72 if (!do_block) 73 goto skip_block_bitmap; 74 75 if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT) 76 ) 77 goto skip_this_block_bitmap; 78 79 retval = ext2fs_get_block_bitmap_range2(fs->block_map, 80 blk_itr, block_nbytes << 3, block_buf); 81 if (retval) 82 goto errout; 83 84 if (i == fs->group_desc_count - 1) { 85 /* Force bitmap padding for the last group */ 86 nbits = EXT2FS_NUM_B2C(fs, 87 ((ext2fs_blocks_count(fs->super) 88 - (__u64) fs->super->s_first_data_block) 89 % (__u64) EXT2_BLOCKS_PER_GROUP(fs->super))); 90 if (nbits) 91 for (j = nbits; j < fs->blocksize * 8; j++) 92 ext2fs_set_bit(j, block_buf); 93 } 94 blk = ext2fs_block_bitmap_loc(fs, i); 95 if (blk) { 96 retval = io_channel_write_blk64(fs->io, blk, 1, 97 block_buf); 98 if (retval) { 99 retval = EXT2_ET_BLOCK_BITMAP_WRITE; 100 goto errout; 101 } 102 } 103 skip_this_block_bitmap: 104 blk_itr += block_nbytes << 3; 105 skip_block_bitmap: 106 107 if (!do_inode) 108 continue; 109 110 if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT) 111 ) 112 goto skip_this_inode_bitmap; 113 114 retval = ext2fs_get_inode_bitmap_range2(fs->inode_map, 115 ino_itr, inode_nbytes << 3, inode_buf); 116 if (retval) 117 goto errout; 118 119 blk = ext2fs_inode_bitmap_loc(fs, i); 120 if (blk) { 121 retval = io_channel_write_blk64(fs->io, blk, 1, 122 inode_buf); 123 if (retval) { 124 retval = EXT2_ET_INODE_BITMAP_WRITE; 125 goto errout; 126 } 127 } 128 skip_this_inode_bitmap: 129 ino_itr += inode_nbytes << 3; 130 131 } 132 if (do_block) { 133 fs->flags &= ~EXT2_FLAG_BB_DIRTY; 134 ext2fs_free_mem(&block_buf); 135 } 136 if (do_inode) { 137 fs->flags &= ~EXT2_FLAG_IB_DIRTY; 138 ext2fs_free_mem(&inode_buf); 139 } 140 return 0; 141errout: 142 if (inode_buf) 143 ext2fs_free_mem(&inode_buf); 144 if (block_buf) 145 ext2fs_free_mem(&block_buf); 146 return retval; 147} 148 149static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block) 150{ 151 dgrp_t i; 152 char *block_bitmap = 0, *inode_bitmap = 0; 153 char *buf; 154 errcode_t retval; 155 int block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8; 156 int inode_nbytes = EXT2_INODES_PER_GROUP(fs->super) / 8; 157 int csum_flag = 0; 158 int do_image = fs->flags & EXT2_FLAG_IMAGE_FILE; 159 unsigned int cnt; 160 blk64_t blk; 161 blk64_t blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block); 162 blk64_t blk_cnt; 163 ext2_ino_t ino_itr = 1; 164 ext2_ino_t ino_cnt; 165 166 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 167 168 fs->write_bitmaps = ext2fs_write_bitmaps; 169 170 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 171 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) 172 csum_flag = 1; 173 174 retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf); 175 if (retval) 176 return retval; 177 if (do_block) { 178 if (fs->block_map) 179 ext2fs_free_block_bitmap(fs->block_map); 180 strcpy(buf, "block bitmap for "); 181 strcat(buf, fs->device_name); 182 retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map); 183 if (retval) 184 goto cleanup; 185 if (do_image) 186 retval = ext2fs_get_mem(fs->blocksize, &block_bitmap); 187 else 188 retval = ext2fs_get_memalign((unsigned) block_nbytes, 189 fs->blocksize, 190 &block_bitmap); 191 192 if (retval) 193 goto cleanup; 194 } else 195 block_nbytes = 0; 196 if (do_inode) { 197 if (fs->inode_map) 198 ext2fs_free_inode_bitmap(fs->inode_map); 199 strcpy(buf, "inode bitmap for "); 200 strcat(buf, fs->device_name); 201 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map); 202 if (retval) 203 goto cleanup; 204 retval = ext2fs_get_mem(do_image ? fs->blocksize : 205 (unsigned) inode_nbytes, &inode_bitmap); 206 if (retval) 207 goto cleanup; 208 } else 209 inode_nbytes = 0; 210 ext2fs_free_mem(&buf); 211 212 if (fs->flags & EXT2_FLAG_IMAGE_FILE) { 213 blk = (fs->image_header->offset_inodemap / fs->blocksize); 214 ino_cnt = fs->super->s_inodes_count; 215 while (inode_nbytes > 0) { 216 retval = io_channel_read_blk64(fs->image_io, blk++, 217 1, inode_bitmap); 218 if (retval) 219 goto cleanup; 220 cnt = fs->blocksize << 3; 221 if (cnt > ino_cnt) 222 cnt = ino_cnt; 223 retval = ext2fs_set_inode_bitmap_range2(fs->inode_map, 224 ino_itr, cnt, inode_bitmap); 225 if (retval) 226 goto cleanup; 227 ino_itr += fs->blocksize << 3; 228 ino_cnt -= fs->blocksize << 3; 229 inode_nbytes -= fs->blocksize; 230 } 231 blk = (fs->image_header->offset_blockmap / 232 fs->blocksize); 233 blk_cnt = (blk64_t)EXT2_CLUSTERS_PER_GROUP(fs->super) * 234 fs->group_desc_count; 235 while (block_nbytes > 0) { 236 retval = io_channel_read_blk64(fs->image_io, blk++, 237 1, block_bitmap); 238 if (retval) 239 goto cleanup; 240 cnt = fs->blocksize << 3; 241 if (cnt > blk_cnt) 242 cnt = blk_cnt; 243 retval = ext2fs_set_block_bitmap_range2(fs->block_map, 244 blk_itr, cnt, block_bitmap); 245 if (retval) 246 goto cleanup; 247 blk_itr += fs->blocksize << 3; 248 blk_cnt -= fs->blocksize << 3; 249 block_nbytes -= fs->blocksize; 250 } 251 goto success_cleanup; 252 } 253 254 for (i = 0; i < fs->group_desc_count; i++) { 255 if (block_bitmap) { 256 blk = ext2fs_block_bitmap_loc(fs, i); 257 if (csum_flag && 258 ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT) && 259 ext2fs_group_desc_csum_verify(fs, i)) 260 blk = 0; 261 if (blk) { 262 retval = io_channel_read_blk64(fs->io, blk, 263 -block_nbytes, block_bitmap); 264 if (retval) { 265 retval = EXT2_ET_BLOCK_BITMAP_READ; 266 goto cleanup; 267 } 268 } else 269 memset(block_bitmap, 0, block_nbytes); 270 cnt = block_nbytes << 3; 271 retval = ext2fs_set_block_bitmap_range2(fs->block_map, 272 blk_itr, cnt, block_bitmap); 273 if (retval) 274 goto cleanup; 275 blk_itr += block_nbytes << 3; 276 } 277 if (inode_bitmap) { 278 blk = ext2fs_inode_bitmap_loc(fs, i); 279 if (csum_flag && 280 ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT) && 281 ext2fs_group_desc_csum_verify(fs, i)) 282 blk = 0; 283 if (blk) { 284 retval = io_channel_read_blk64(fs->io, blk, 285 -inode_nbytes, inode_bitmap); 286 if (retval) { 287 retval = EXT2_ET_INODE_BITMAP_READ; 288 goto cleanup; 289 } 290 } else 291 memset(inode_bitmap, 0, inode_nbytes); 292 cnt = inode_nbytes << 3; 293 retval = ext2fs_set_inode_bitmap_range2(fs->inode_map, 294 ino_itr, cnt, inode_bitmap); 295 if (retval) 296 goto cleanup; 297 ino_itr += inode_nbytes << 3; 298 } 299 } 300success_cleanup: 301 if (inode_bitmap) 302 ext2fs_free_mem(&inode_bitmap); 303 if (block_bitmap) 304 ext2fs_free_mem(&block_bitmap); 305 return 0; 306 307cleanup: 308 if (do_block) { 309 ext2fs_free_mem(&fs->block_map); 310 fs->block_map = 0; 311 } 312 if (do_inode) { 313 ext2fs_free_mem(&fs->inode_map); 314 fs->inode_map = 0; 315 } 316 if (inode_bitmap) 317 ext2fs_free_mem(&inode_bitmap); 318 if (block_bitmap) 319 ext2fs_free_mem(&block_bitmap); 320 if (buf) 321 ext2fs_free_mem(&buf); 322 return retval; 323} 324 325errcode_t ext2fs_read_inode_bitmap(ext2_filsys fs) 326{ 327 return read_bitmaps(fs, 1, 0); 328} 329 330errcode_t ext2fs_read_block_bitmap(ext2_filsys fs) 331{ 332 return read_bitmaps(fs, 0, 1); 333} 334 335errcode_t ext2fs_write_inode_bitmap(ext2_filsys fs) 336{ 337 return write_bitmaps(fs, 1, 0); 338} 339 340errcode_t ext2fs_write_block_bitmap (ext2_filsys fs) 341{ 342 return write_bitmaps(fs, 0, 1); 343} 344 345errcode_t ext2fs_read_bitmaps(ext2_filsys fs) 346{ 347 if (fs->inode_map && fs->block_map) 348 return 0; 349 350 return read_bitmaps(fs, !fs->inode_map, !fs->block_map); 351} 352 353errcode_t ext2fs_write_bitmaps(ext2_filsys fs) 354{ 355 int do_inode = fs->inode_map && ext2fs_test_ib_dirty(fs); 356 int do_block = fs->block_map && ext2fs_test_bb_dirty(fs); 357 358 if (!do_inode && !do_block) 359 return 0; 360 361 return write_bitmaps(fs, do_inode, do_block); 362} 363