1 /* 2 * mkjournal.c --- make a journal for a filesystem 3 * 4 * Copyright (C) 2000 Theodore Ts'o. 5 * 6 * %Begin-Header% 7 * This file may be redistributed under the terms of the GNU Public 8 * License. 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 #if HAVE_ERRNO_H 18 #include <errno.h> 19 #endif 20 #include <fcntl.h> 21 #include <time.h> 22 #if HAVE_SYS_STAT_H 23 #include <sys/stat.h> 24 #endif 25 #if HAVE_SYS_TYPES_H 26 #include <sys/types.h> 27 #endif 28 #if HAVE_SYS_IOCTL_H 29 #include <sys/ioctl.h> 30 #endif 31 #if HAVE_NETINET_IN_H 32 #include <netinet/in.h> 33 #endif 34 35 #include "ext2_fs.h" 36 #include "e2p/e2p.h" 37 #include "ext2fs.h" 38 #include "jfs_user.h" 39 40 /* 41 * This function automatically sets up the journal superblock and 42 * returns it as an allocated block. 43 */ 44 errcode_t ext2fs_create_journal_superblock(ext2_filsys fs, 45 __u32 size, int flags, 46 char **ret_jsb) 47 { 48 errcode_t retval; 49 journal_superblock_t *jsb; 50 51 if (size < 1024) 52 return EXT2_ET_JOURNAL_TOO_SMALL; 53 54 if ((retval = ext2fs_get_mem(fs->blocksize, &jsb))) 55 return retval; 56 57 memset (jsb, 0, fs->blocksize); 58 59 jsb->s_header.h_magic = htonl(JFS_MAGIC_NUMBER); 60 if (flags & EXT2_MKJOURNAL_V1_SUPER) 61 jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V1); 62 else 63 jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V2); 64 jsb->s_blocksize = htonl(fs->blocksize); 65 jsb->s_maxlen = htonl(size); 66 jsb->s_nr_users = htonl(1); 67 jsb->s_first = htonl(1); 68 jsb->s_sequence = htonl(1); 69 memcpy(jsb->s_uuid, fs->super->s_uuid, sizeof(fs->super->s_uuid)); 70 /* 71 * If we're creating an external journal device, we need to 72 * adjust these fields. 73 */ 74 if (fs->super->s_feature_incompat & 75 EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) { 76 jsb->s_nr_users = 0; 77 if (fs->blocksize == 1024) 78 jsb->s_first = htonl(3); 79 else 80 jsb->s_first = htonl(2); 81 } 82 83 *ret_jsb = (char *) jsb; 84 return 0; 85 } 86 87 /* 88 * This function writes a journal using POSIX routines. It is used 89 * for creating external journals and creating journals on live 90 * filesystems. 91 */ 92 static errcode_t write_journal_file(ext2_filsys fs, char *filename, 93 blk_t size, int flags) 94 { 95 errcode_t retval; 96 char *buf = 0; 97 int fd, ret_size; 98 blk_t i; 99 100 if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf))) 101 return retval; 102 103 /* Open the device or journal file */ 104 if ((fd = open(filename, O_WRONLY)) < 0) { 105 retval = errno; 106 goto errout; 107 } 108 109 /* Write the superblock out */ 110 retval = EXT2_ET_SHORT_WRITE; 111 ret_size = write(fd, buf, fs->blocksize); 112 if (ret_size < 0) { 113 retval = errno; 114 goto errout; 115 } 116 if (ret_size != (int) fs->blocksize) 117 goto errout; 118 memset(buf, 0, fs->blocksize); 119 120 for (i = 1; i < size; i++) { 121 ret_size = write(fd, buf, fs->blocksize); 122 if (ret_size < 0) { 123 retval = errno; 124 goto errout; 125 } 126 if (ret_size != (int) fs->blocksize) 127 goto errout; 128 } 129 close(fd); 130 131 retval = 0; 132 errout: 133 ext2fs_free_mem(&buf); 134 return retval; 135 } 136 137 /* 138 * Helper function for creating the journal using direct I/O routines 139 */ 140 struct mkjournal_struct { 141 int num_blocks; 142 int newblocks; 143 char *buf; 144 errcode_t err; 145 }; 146 147 static int mkjournal_proc(ext2_filsys fs, 148 blk_t *blocknr, 149 e2_blkcnt_t blockcnt, 150 blk_t ref_block EXT2FS_ATTR((unused)), 151 int ref_offset EXT2FS_ATTR((unused)), 152 void *priv_data) 153 { 154 struct mkjournal_struct *es = (struct mkjournal_struct *) priv_data; 155 blk_t new_blk; 156 static blk_t last_blk = 0; 157 errcode_t retval; 158 159 if (*blocknr) { 160 last_blk = *blocknr; 161 return 0; 162 } 163 retval = ext2fs_new_block(fs, last_blk, 0, &new_blk); 164 if (retval) { 165 es->err = retval; 166 return BLOCK_ABORT; 167 } 168 if (blockcnt > 0) 169 es->num_blocks--; 170 171 es->newblocks++; 172 retval = io_channel_write_blk(fs->io, new_blk, 1, es->buf); 173 174 if (blockcnt == 0) 175 memset(es->buf, 0, fs->blocksize); 176 177 if (retval) { 178 es->err = retval; 179 return BLOCK_ABORT; 180 } 181 *blocknr = new_blk; 182 last_blk = new_blk; 183 ext2fs_block_alloc_stats(fs, new_blk, +1); 184 185 if (es->num_blocks == 0) 186 return (BLOCK_CHANGED | BLOCK_ABORT); 187 else 188 return BLOCK_CHANGED; 189 190 } 191 192 /* 193 * This function creates a journal using direct I/O routines. 194 */ 195 static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino, 196 blk_t size, int flags) 197 { 198 char *buf; 199 errcode_t retval; 200 struct ext2_inode inode; 201 struct mkjournal_struct es; 202 203 if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf))) 204 return retval; 205 206 if ((retval = ext2fs_read_bitmaps(fs))) 207 return retval; 208 209 if ((retval = ext2fs_read_inode(fs, journal_ino, &inode))) 210 return retval; 211 212 if (inode.i_blocks > 0) 213 return EEXIST; 214 215 es.num_blocks = size; 216 es.newblocks = 0; 217 es.buf = buf; 218 es.err = 0; 219 220 retval = ext2fs_block_iterate2(fs, journal_ino, BLOCK_FLAG_APPEND, 221 0, mkjournal_proc, &es); 222 if (es.err) { 223 retval = es.err; 224 goto errout; 225 } 226 227 if ((retval = ext2fs_read_inode(fs, journal_ino, &inode))) 228 goto errout; 229 230 inode.i_size += fs->blocksize * size; 231 inode.i_blocks += (fs->blocksize / 512) * es.newblocks; 232 inode.i_mtime = inode.i_ctime = fs->now ? fs->now : time(0); 233 inode.i_links_count = 1; 234 inode.i_mode = LINUX_S_IFREG | 0600; 235 236 if ((retval = ext2fs_write_inode(fs, journal_ino, &inode))) 237 goto errout; 238 retval = 0; 239 240 memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4); 241 fs->super->s_jnl_blocks[16] = inode.i_size; 242 fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS; 243 ext2fs_mark_super_dirty(fs); 244 245 errout: 246 ext2fs_free_mem(&buf); 247 return retval; 248 } 249 250 /* 251 * Find a reasonable journal file size (in blocks) given the number of blocks 252 * in the filesystem. For very small filesystems, it is not reasonable to 253 * have a journal that fills more than half of the filesystem. 254 */ 255 int ext2fs_default_journal_size(__u64 blocks) 256 { 257 if (blocks < 2048) 258 return -1; 259 if (blocks < 32768) 260 return (1024); 261 if (blocks < 256*1024) 262 return (4096); 263 if (blocks < 512*1024) 264 return (8192); 265 if (blocks < 1024*1024) 266 return (16384); 267 return 32768; 268 } 269 270 /* 271 * This function adds a journal device to a filesystem 272 */ 273 errcode_t ext2fs_add_journal_device(ext2_filsys fs, ext2_filsys journal_dev) 274 { 275 struct stat st; 276 errcode_t retval; 277 char buf[1024]; 278 journal_superblock_t *jsb; 279 int start; 280 __u32 i, nr_users; 281 282 /* Make sure the device exists and is a block device */ 283 if (stat(journal_dev->device_name, &st) < 0) 284 return errno; 285 286 if (!S_ISBLK(st.st_mode)) 287 return EXT2_ET_JOURNAL_NOT_BLOCK; /* Must be a block device */ 288 289 /* Get the journal superblock */ 290 start = 1; 291 if (journal_dev->blocksize == 1024) 292 start++; 293 if ((retval = io_channel_read_blk(journal_dev->io, start, -1024, buf))) 294 return retval; 295 296 jsb = (journal_superblock_t *) buf; 297 if ((jsb->s_header.h_magic != (unsigned) ntohl(JFS_MAGIC_NUMBER)) || 298 (jsb->s_header.h_blocktype != (unsigned) ntohl(JFS_SUPERBLOCK_V2))) 299 return EXT2_ET_NO_JOURNAL_SB; 300 301 if (ntohl(jsb->s_blocksize) != (unsigned long) fs->blocksize) 302 return EXT2_ET_UNEXPECTED_BLOCK_SIZE; 303 304 /* Check and see if this filesystem has already been added */ 305 nr_users = ntohl(jsb->s_nr_users); 306 for (i=0; i < nr_users; i++) { 307 if (memcmp(fs->super->s_uuid, 308 &jsb->s_users[i*16], 16) == 0) 309 break; 310 } 311 if (i >= nr_users) { 312 memcpy(&jsb->s_users[nr_users*16], 313 fs->super->s_uuid, 16); 314 jsb->s_nr_users = htonl(nr_users+1); 315 } 316 317 /* Writeback the journal superblock */ 318 if ((retval = io_channel_write_blk(journal_dev->io, start, -1024, buf))) 319 return retval; 320 321 fs->super->s_journal_inum = 0; 322 fs->super->s_journal_dev = st.st_rdev; 323 memcpy(fs->super->s_journal_uuid, jsb->s_uuid, 324 sizeof(fs->super->s_journal_uuid)); 325 fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL; 326 ext2fs_mark_super_dirty(fs); 327 return 0; 328 } 329 330 /* 331 * This function adds a journal inode to a filesystem, using either 332 * POSIX routines if the filesystem is mounted, or using direct I/O 333 * functions if it is not. 334 */ 335 errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t size, int flags) 336 { 337 errcode_t retval; 338 ext2_ino_t journal_ino; 339 struct stat st; 340 char jfile[1024]; 341 int mount_flags, f; 342 int fd = -1; 343 344 if ((retval = ext2fs_check_mount_point(fs->device_name, &mount_flags, 345 jfile, sizeof(jfile)-10))) 346 return retval; 347 348 if (mount_flags & EXT2_MF_MOUNTED) { 349 strcat(jfile, "/.journal"); 350 351 /* 352 * If .../.journal already exists, make sure any 353 * immutable or append-only flags are cleared. 354 */ 355 #if defined(HAVE_CHFLAGS) && defined(UF_NODUMP) 356 (void) chflags (jfile, 0); 357 #else 358 #if HAVE_EXT2_IOCTLS 359 fd = open(jfile, O_RDONLY); 360 if (fd >= 0) { 361 f = 0; 362 ioctl(fd, EXT2_IOC_SETFLAGS, &f); 363 close(fd); 364 } 365 #endif 366 #endif 367 368 /* Create the journal file */ 369 if ((fd = open(jfile, O_CREAT|O_WRONLY, 0600)) < 0) 370 return errno; 371 372 if ((retval = write_journal_file(fs, jfile, size, flags))) 373 goto errout; 374 375 /* Get inode number of the journal file */ 376 if (fstat(fd, &st) < 0) 377 goto errout; 378 379 #if defined(HAVE_CHFLAGS) && defined(UF_NODUMP) 380 retval = fchflags (fd, UF_NODUMP|UF_IMMUTABLE); 381 #else 382 #if HAVE_EXT2_IOCTLS 383 f = EXT2_NODUMP_FL | EXT2_IMMUTABLE_FL; 384 retval = ioctl(fd, EXT2_IOC_SETFLAGS, &f); 385 #endif 386 #endif 387 if (retval) 388 goto errout; 389 390 close(fd); 391 journal_ino = st.st_ino; 392 } else { 393 if ((mount_flags & EXT2_MF_BUSY) && 394 !(fs->flags & EXT2_FLAG_EXCLUSIVE)) { 395 retval = EBUSY; 396 goto errout; 397 } 398 journal_ino = EXT2_JOURNAL_INO; 399 if ((retval = write_journal_inode(fs, journal_ino, 400 size, flags))) 401 return retval; 402 } 403 404 fs->super->s_journal_inum = journal_ino; 405 fs->super->s_journal_dev = 0; 406 memset(fs->super->s_journal_uuid, 0, 407 sizeof(fs->super->s_journal_uuid)); 408 fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL; 409 410 ext2fs_mark_super_dirty(fs); 411 return 0; 412 errout: 413 if (fd > 0) 414 close(fd); 415 return retval; 416 } 417 418 #ifdef DEBUG 419 main(int argc, char **argv) 420 { 421 errcode_t retval; 422 char *device_name; 423 ext2_filsys fs; 424 425 if (argc < 2) { 426 fprintf(stderr, "Usage: %s filesystem\n", argv[0]); 427 exit(1); 428 } 429 device_name = argv[1]; 430 431 retval = ext2fs_open (device_name, EXT2_FLAG_RW, 0, 0, 432 unix_io_manager, &fs); 433 if (retval) { 434 com_err(argv[0], retval, "while opening %s", device_name); 435 exit(1); 436 } 437 438 retval = ext2fs_add_journal_inode(fs, 1024); 439 if (retval) { 440 com_err(argv[0], retval, "while adding journal to %s", 441 device_name); 442 exit(1); 443 } 444 retval = ext2fs_flush(fs); 445 if (retval) { 446 printf("Warning, had trouble writing out superblocks.\n"); 447 } 448 ext2fs_close(fs); 449 exit(0); 450 451 } 452 #endif 453
