lib/ext2fs/mkjournal.c

   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 Library
   8  * General Public License, version 2.
   9  * %End-Header%
  10  */
  11
  12 #include "config.h"
  13 #include <stdio.h>
  14 #include <string.h>
  15 #if HAVE_UNISTD_H
  16 #include <unistd.h>
  17 #endif
  18 #if HAVE_ERRNO_H
  19 #include <errno.h>
  20 #endif
  21 #include <fcntl.h>
  22 #include <time.h>
  23 #if HAVE_SYS_STAT_H
  24 #include <sys/stat.h>
  25 #endif
  26 #if HAVE_SYS_TYPES_H
  27 #include <sys/types.h>
  28 #endif
  29 #if HAVE_SYS_IOCTL_H
  30 #include <sys/ioctl.h>
  31 #endif
  32 #if HAVE_NETINET_IN_H
  33 #include <netinet/in.h>
  34 #endif
  35 #ifdef __linux__
  36 #include <sys/utsname.h>
  37 #define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))
  38 #endif
  39
  40 #include "ext2_fs.h"
  41 #include "e2p/e2p.h"
  42 #include "ext2fs.h"
  43 #include "jfs_user.h"
  44
  45 /*
  46  * This function automatically sets up the journal superblock and
  47  * returns it as an allocated block.
  48  */
  49 errcode_t ext2fs_create_journal_superblock(ext2_filsys fs,
  50                                            __u32 num_blocks, int flags,
  51                                            char  **ret_jsb)
  52 {
  53         errcode_t               retval;
  54         journal_superblock_t    *jsb;
  55
  56         if (num_blocks < JFS_MIN_JOURNAL_BLOCKS)
  57                 return EXT2_ET_JOURNAL_TOO_SMALL;
  58
  59         if ((retval = ext2fs_get_mem(fs->blocksize, &jsb)))
  60                 return retval;
  61
  62         memset (jsb, 0, fs->blocksize);
  63
  64         jsb->s_header.h_magic = htonl(JFS_MAGIC_NUMBER);
  65         if (flags & EXT2_MKJOURNAL_V1_SUPER)
  66                 jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V1);
  67         else
  68                 jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V2);
  69         jsb->s_blocksize = htonl(fs->blocksize);
  70         jsb->s_maxlen = htonl(num_blocks);
  71         jsb->s_nr_users = htonl(1);
  72         jsb->s_first = htonl(1);
  73         jsb->s_sequence = htonl(1);
  74         memcpy(jsb->s_uuid, fs->super->s_uuid, sizeof(fs->super->s_uuid));
  75         /*
  76          * If we're creating an external journal device, we need to
  77          * adjust these fields.
  78          */
  79         if (fs->super->s_feature_incompat &
  80             EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
  81                 jsb->s_nr_users = 0;
  82                 jsb->s_first = htonl(ext2fs_journal_sb_start(fs->blocksize) + 1);
  83         }
  84
  85         *ret_jsb = (char *) jsb;
  86         return 0;
  87 }
  88
  89 /*
  90  * This function writes a journal using POSIX routines.  It is used
  91  * for creating external journals and creating journals on live
  92  * filesystems.
  93  */
  94 static errcode_t write_journal_file(ext2_filsys fs, char *filename,
  95                                     blk_t num_blocks, int flags)
  96 {
  97         errcode_t       retval;
  98         char            *buf = 0;
  99         int             fd, ret_size;
 100         blk_t           i;
 101
 102         if ((retval = ext2fs_create_journal_superblock(fs, num_blocks, flags,
 103                                                        &buf)))
 104                 return retval;
 105
 106         /* Open the device or journal file */
 107         if ((fd = open(filename, O_WRONLY)) < 0) {
 108                 retval = errno;
 109                 goto errfree;
 110         }
 111
 112         /* Write the superblock out */
 113         retval = EXT2_ET_SHORT_WRITE;
 114         ret_size = write(fd, buf, fs->blocksize);
 115         if (ret_size < 0) {
 116                 retval = errno;
 117                 goto errout;
 118         }
 119         if (ret_size != (int) fs->blocksize)
 120                 goto errout;
 121         memset(buf, 0, fs->blocksize);
 122
 123         if (flags & EXT2_MKJOURNAL_LAZYINIT)
 124                 goto success;
 125
 126         for (i = 1; i < num_blocks; i++) {
 127                 ret_size = write(fd, buf, fs->blocksize);
 128                 if (ret_size < 0) {
 129                         retval = errno;
 130                         goto errout;
 131                 }
 132                 if (ret_size != (int) fs->blocksize)
 133                         goto errout;
 134         }
 135
 136 success:
 137         retval = 0;
 138 errout:
 139         close(fd);
 140 errfree:
 141         ext2fs_free_mem(&buf);
 142         return retval;
 143 }
 144
 145 /*
 146  * Convenience function which zeros out _num_ blocks starting at
 147  * _blk_.  In case of an error, the details of the error is returned
 148  * via _ret_blk_ and _ret_count_ if they are non-NULL pointers.
 149  * Returns 0 on success, and an error code on an error.
 150  *
 151  * As a special case, if the first argument is NULL, then it will
 152  * attempt to free the static zeroizing buffer.  (This is to keep
 153  * programs that check for memory leaks happy.)
 154  */
 155 #define STRIDE_LENGTH 8
 156 errcode_t ext2fs_zero_blocks2(ext2_filsys fs, blk64_t blk, int num,
 157                               blk64_t *ret_blk, int *ret_count)
 158 {
 159         int             j, count;
 160         static char     *buf;
 161         errcode_t       retval;
 162
 163         /* If fs is null, clean up the static buffer and return */
 164         if (!fs) {
 165                 if (buf) {
 166                         free(buf);
 167                         buf = 0;
 168                 }
 169                 return 0;
 170         }
 171         /* Allocate the zeroizing buffer if necessary */
 172         if (!buf) {
 173                 buf = malloc(fs->blocksize * STRIDE_LENGTH);
 174                 if (!buf)
 175                         return ENOMEM;
 176                 memset(buf, 0, fs->blocksize * STRIDE_LENGTH);
 177         }
 178         /* OK, do the write loop */
 179         j=0;
 180         while (j < num) {
 181                 if (blk % STRIDE_LENGTH) {
 182                         count = STRIDE_LENGTH - (blk % STRIDE_LENGTH);
 183                         if (count > (num - j))
 184                                 count = num - j;
 185                 } else {
 186                         count = num - j;
 187                         if (count > STRIDE_LENGTH)
 188                                 count = STRIDE_LENGTH;
 189                 }
 190                 retval = io_channel_write_blk64(fs->io, blk, count, buf);
 191                 if (retval) {
 192                         if (ret_count)
 193                                 *ret_count = count;
 194                         if (ret_blk)
 195                                 *ret_blk = blk;
 196                         return retval;
 197                 }
 198                 j += count; blk += count;
 199         }
 200         return 0;
 201 }
 202
 203 errcode_t ext2fs_zero_blocks(ext2_filsys fs, blk_t blk, int num,
 204                              blk_t *ret_blk, int *ret_count)
 205 {
 206         blk64_t ret_blk2;
 207         errcode_t retval;
 208
 209         retval = ext2fs_zero_blocks2(fs, blk, num, &ret_blk2, ret_count);
 210         if (retval)
 211                 *ret_blk = (blk_t) ret_blk2;
 212         return retval;
 213 }
 214
 215 /*
 216  * Helper function for creating the journal using direct I/O routines
 217  */
 218 struct mkjournal_struct {
 219         int             num_blocks;
 220         int             newblocks;
 221         blk64_t         goal;
 222         blk64_t         blk_to_zero;
 223         int             zero_count;
 224         int             flags;
 225         char            *buf;
 226         errcode_t       err;
 227 };
 228
 229 static int mkjournal_proc(ext2_filsys   fs,
 230                           blk64_t       *blocknr,
 231                           e2_blkcnt_t   blockcnt,
 232                           blk64_t       ref_block EXT2FS_ATTR((unused)),
 233                           int           ref_offset EXT2FS_ATTR((unused)),
 234                           void          *priv_data)
 235 {
 236         struct mkjournal_struct *es = (struct mkjournal_struct *) priv_data;
 237         blk64_t new_blk;
 238         errcode_t       retval;
 239
 240         if (*blocknr) {
 241                 es->goal = *blocknr;
 242                 return 0;
 243         }
 244         if (blockcnt &&
 245             (EXT2FS_B2C(fs, es->goal) == EXT2FS_B2C(fs, es->goal+1)))
 246                 new_blk = es->goal+1;
 247         else {
 248                 es->goal &= ~EXT2FS_CLUSTER_MASK(fs);
 249                 retval = ext2fs_new_block2(fs, es->goal, 0, &new_blk);
 250                 if (retval) {
 251                         es->err = retval;
 252                         return BLOCK_ABORT;
 253                 }
 254                 ext2fs_block_alloc_stats2(fs, new_blk, +1);
 255                 es->newblocks++;
 256         }
 257         if (blockcnt >= 0)
 258                 es->num_blocks--;
 259
 260         retval = 0;
 261         if (blockcnt <= 0)
 262                 retval = io_channel_write_blk64(fs->io, new_blk, 1, es->buf);
 263         else if (!(es->flags & EXT2_MKJOURNAL_LAZYINIT)) {
 264                 if (es->zero_count) {
 265                         if ((es->blk_to_zero + es->zero_count == new_blk) &&
 266                             (es->zero_count < 1024))
 267                                 es->zero_count++;
 268                         else {
 269                                 retval = ext2fs_zero_blocks2(fs,
 270                                                              es->blk_to_zero,
 271                                                              es->zero_count,
 272                                                              0, 0);
 273                                 es->zero_count = 0;
 274                         }
 275                 }
 276                 if (es->zero_count == 0) {
 277                         es->blk_to_zero = new_blk;
 278                         es->zero_count = 1;
 279                 }
 280         }
 281
 282         if (blockcnt == 0)
 283                 memset(es->buf, 0, fs->blocksize);
 284
 285         if (retval) {
 286                 es->err = retval;
 287                 return BLOCK_ABORT;
 288         }
 289         *blocknr = es->goal = new_blk;
 290
 291         if (es->num_blocks == 0)
 292                 return (BLOCK_CHANGED | BLOCK_ABORT);
 293         else
 294                 return BLOCK_CHANGED;
 295
 296 }
 297
 298 /*
 299  * Calculate the initial goal block to be roughly at the middle of the
 300  * filesystem.  Pick a group that has the largest number of free
 301  * blocks.
 302  */
 303 static blk64_t get_midpoint_journal_block(ext2_filsys fs)
 304 {
 305         dgrp_t  group, start, end, i, log_flex;
 306
 307         group = ext2fs_group_of_blk2(fs, (ext2fs_blocks_count(fs->super) -
 308                                          fs->super->s_first_data_block) / 2);
 309         log_flex = 1 << fs->super->s_log_groups_per_flex;
 310         if (fs->super->s_log_groups_per_flex && (group > log_flex)) {
 311                 group = group & ~(log_flex - 1);
 312                 while ((group < fs->group_desc_count) &&
 313                        ext2fs_bg_free_blocks_count(fs, group) == 0)
 314                         group++;
 315                 if (group == fs->group_desc_count)
 316                         group = 0;
 317                 start = group;
 318         } else
 319                 start = (group > 0) ? group-1 : group;
 320         end = ((group+1) < fs->group_desc_count) ? group+1 : group;
 321         group = start;
 322         for (i = start + 1; i <= end; i++)
 323                 if (ext2fs_bg_free_blocks_count(fs, i) >
 324                     ext2fs_bg_free_blocks_count(fs, group))
 325                         group = i;
 326         return ext2fs_group_first_block2(fs, group);
 327 }
 328
 329 /*
 330  * This function creates a journal using direct I/O routines.
 331  */
 332 static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino,
 333                                      blk_t num_blocks, blk64_t goal, int flags)
 334 {
 335         char                    *buf;
 336         errcode_t               retval;
 337         struct ext2_inode       inode;
 338         unsigned long long      inode_size;
 339         struct mkjournal_struct es;
 340
 341         if ((retval = ext2fs_create_journal_superblock(fs, num_blocks, flags,
 342                                                        &buf)))
 343                 return retval;
 344
 345         if ((retval = ext2fs_read_bitmaps(fs)))
 346                 goto out2;
 347
 348         if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
 349                 goto out2;
 350
 351         if (inode.i_blocks > 0) {
 352                 retval = EEXIST;
 353                 goto out2;
 354         }
 355
 356         es.num_blocks = num_blocks;
 357         es.newblocks = 0;
 358         es.buf = buf;
 359         es.err = 0;
 360         es.flags = flags;
 361         es.zero_count = 0;
 362         es.goal = (goal != ~0ULL) ? goal : get_midpoint_journal_block(fs);
 363
 364         if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS) {
 365                 inode.i_flags |= EXT4_EXTENTS_FL;
 366                 if ((retval = ext2fs_write_inode(fs, journal_ino, &inode)))
 367                         goto out2;
 368         }
 369
 370         retval = ext2fs_block_iterate3(fs, journal_ino, BLOCK_FLAG_APPEND,
 371                                        0, mkjournal_proc, &es);
 372         if (es.err) {
 373                 retval = es.err;
 374                 goto errout;
 375         }
 376         if (es.zero_count) {
 377                 retval = ext2fs_zero_blocks2(fs, es.blk_to_zero,
 378                                             es.zero_count, 0, 0);
 379                 if (retval)
 380                         goto errout;
 381         }
 382
 383         if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
 384                 goto errout;
 385
 386         inode_size = (unsigned long long)fs->blocksize * num_blocks;
 387         ext2fs_iblk_add_blocks(fs, &inode, es.newblocks);
 388         inode.i_mtime = inode.i_ctime = fs->now ? fs->now : time(0);
 389         inode.i_links_count = 1;
 390         inode.i_mode = LINUX_S_IFREG | 0600;
 391         retval = ext2fs_inode_size_set(fs, &inode, inode_size);
 392         if (retval)
 393                 goto errout;
 394
 395         if ((retval = ext2fs_write_new_inode(fs, journal_ino, &inode)))
 396                 goto errout;
 397         retval = 0;
 398
 399         memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
 400         fs->super->s_jnl_blocks[15] = inode.i_size_high;
 401         fs->super->s_jnl_blocks[16] = inode.i_size;
 402         fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
 403         ext2fs_mark_super_dirty(fs);
 404
 405 errout:
 406         ext2fs_zero_blocks2(0, 0, 0, 0, 0);
 407 out2:
 408         ext2fs_free_mem(&buf);
 409         return retval;
 410 }
 411
 412 #ifdef __linux__
 413 static int parse_version_number(const char *s)
 414 {
 415         int     major, minor, rev;
 416         char    *endptr;
 417         const char *cp = s;
 418
 419         if (!s)
 420                 return 0;
 421         major = strtol(cp, &endptr, 10);
 422         if (cp == endptr || *endptr != '.')
 423                 return 0;
 424         cp = endptr + 1;
 425         minor = strtol(cp, &endptr, 10);
 426         if (cp == endptr || *endptr != '.')
 427                 return 0;
 428         cp = endptr + 1;
 429         rev = strtol(cp, &endptr, 10);
 430         if (cp == endptr)
 431                 return 0;
 432         return KERNEL_VERSION(major, minor, rev);
 433 }
 434
 435 int ext2fs_is_before_linux_ver(unsigned int major, unsigned int minor,
 436                                unsigned int rev)
 437 {
 438         struct          utsname ut;
 439         static int      linux_version_code = -1;
 440
 441         if (uname(&ut)) {
 442                 perror("uname");
 443                 exit(1);
 444         }
 445         if (linux_version_code < 0)
 446                 linux_version_code = parse_version_number(ut.release);
 447         if (linux_version_code == 0)
 448                 return 0;
 449
 450         return linux_version_code < KERNEL_VERSION(major, minor, rev);
 451 }
 452 #else
 453 int ext2fs_is_before_linux_ver(unsigned int major, unsigned int minor,
 454                                unsigned int rev)
 455 {
 456         return 0;
 457 }
 458 #endif
 459
 460 /*
 461  * Find a reasonable journal file size (in blocks) given the number of blocks
 462  * in the filesystem.  For very small filesystems, it is not reasonable to
 463  * have a journal that fills more than half of the filesystem.
 464  */
 465 int ext2fs_default_journal_size(__u64 num_blocks)
 466 {
 467         if (num_blocks < 2048)
 468                 return -1;
 469         if (num_blocks <= 8192)
 470                 return (1024);
 471         if (num_blocks < 32768)
 472                 return (2048);
 473         if (num_blocks < 256*1024)
 474                 return (4096);
 475         if (num_blocks < 512*1024)
 476                 return (8192);
 477         if (num_blocks < 1024*1024)
 478                 return (16384);
 479         return 32768;
 480 }
 481
 482 int ext2fs_journal_sb_start(int blocksize)
 483 {
 484         if (blocksize == EXT2_MIN_BLOCK_SIZE)
 485                 return 2;
 486         return 1;
 487 }
 488
 489 /*
 490  * This function adds a journal device to a filesystem
 491  */
 492 errcode_t ext2fs_add_journal_device(ext2_filsys fs, ext2_filsys journal_dev)
 493 {
 494         struct stat     st;
 495         errcode_t       retval;
 496         char            buf[SUPERBLOCK_SIZE];
 497         journal_superblock_t    *jsb;
 498         int             start;
 499         __u32           i, nr_users;
 500
 501         /* Make sure the device exists and is a block device */
 502         if (stat(journal_dev->device_name, &st) < 0)
 503                 return errno;
 504
 505         if (!S_ISBLK(st.st_mode))
 506                 return EXT2_ET_JOURNAL_NOT_BLOCK; /* Must be a block device */
 507
 508         /* Get the journal superblock */
 509         start = ext2fs_journal_sb_start(journal_dev->blocksize);
 510         if ((retval = io_channel_read_blk64(journal_dev->io, start,
 511                                             -SUPERBLOCK_SIZE,
 512                                             buf)))
 513                 return retval;
 514
 515         jsb = (journal_superblock_t *) buf;
 516         if ((jsb->s_header.h_magic != (unsigned) ntohl(JFS_MAGIC_NUMBER)) ||
 517             (jsb->s_header.h_blocktype != (unsigned) ntohl(JFS_SUPERBLOCK_V2)))
 518                 return EXT2_ET_NO_JOURNAL_SB;
 519
 520         if (ntohl(jsb->s_blocksize) != (unsigned long) fs->blocksize)
 521                 return EXT2_ET_UNEXPECTED_BLOCK_SIZE;
 522
 523         /* Check and see if this filesystem has already been added */
 524         nr_users = ntohl(jsb->s_nr_users);
 525         for (i=0; i < nr_users; i++) {
 526                 if (memcmp(fs->super->s_uuid,
 527                            &jsb->s_users[i*16], 16) == 0)
 528                         break;
 529         }
 530         if (i >= nr_users) {
 531                 memcpy(&jsb->s_users[nr_users*16],
 532                        fs->super->s_uuid, 16);
 533                 jsb->s_nr_users = htonl(nr_users+1);
 534         }
 535
 536         /* Writeback the journal superblock */
 537         if ((retval = io_channel_write_blk64(journal_dev->io, start,
 538                                             -SUPERBLOCK_SIZE, buf)))
 539                 return retval;
 540
 541         fs->super->s_journal_inum = 0;
 542         fs->super->s_journal_dev = st.st_rdev;
 543         memcpy(fs->super->s_journal_uuid, jsb->s_uuid,
 544                sizeof(fs->super->s_journal_uuid));
 545         fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 546         ext2fs_mark_super_dirty(fs);
 547         return 0;
 548 }
 549
 550 /*
 551  * This function adds a journal inode to a filesystem, using either
 552  * POSIX routines if the filesystem is mounted, or using direct I/O
 553  * functions if it is not.
 554  */
 555 errcode_t ext2fs_add_journal_inode2(ext2_filsys fs, blk_t num_blocks,
 556                                     blk64_t goal, int flags)
 557 {
 558         errcode_t               retval;
 559         ext2_ino_t              journal_ino;
 560         struct stat             st;
 561         char                    jfile[1024];
 562         int                     mount_flags;
 563         int                     fd = -1;
 564
 565         if (flags & EXT2_MKJOURNAL_NO_MNT_CHECK)
 566                 mount_flags = 0;
 567         else if ((retval = ext2fs_check_mount_point(fs->device_name,
 568                                                     &mount_flags,
 569                                                     jfile, sizeof(jfile)-10)))
 570                 return retval;
 571
 572         if (mount_flags & EXT2_MF_MOUNTED) {
 573 #if HAVE_EXT2_IOCTLS
 574                 int f = 0;
 575 #endif
 576                 strcat(jfile, "/.journal");
 577
 578                 /*
 579                  * If .../.journal already exists, make sure any
 580                  * immutable or append-only flags are cleared.
 581                  */
 582 #if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
 583                 (void) chflags (jfile, 0);
 584 #else
 585 #if HAVE_EXT2_IOCTLS
 586                 fd = open(jfile, O_RDONLY);
 587                 if (fd >= 0) {
 588                         retval = ioctl(fd, EXT2_IOC_SETFLAGS, &f);
 589                         close(fd);
 590                         if (retval)
 591                                 return retval;
 592                 }
 593 #endif
 594 #endif
 595
 596                 /* Create the journal file */
 597                 if ((fd = open(jfile, O_CREAT|O_WRONLY, 0600)) < 0)
 598                         return errno;
 599
 600                 /* Note that we can't do lazy journal initialization for mounted
 601                  * filesystems, since the zero writing is also allocating the
 602                  * journal blocks.  We could use fallocate, but not all kernels
 603                  * support that, and creating a journal on a mounted ext2
 604                  * filesystems is extremely rare these days...  Ignore it. */
 605                 flags &= ~EXT2_MKJOURNAL_LAZYINIT;
 606
 607                 if ((retval = write_journal_file(fs, jfile, num_blocks, flags)))
 608                         goto errout;
 609
 610                 /* Get inode number of the journal file */
 611                 if (fstat(fd, &st) < 0) {
 612                         retval = errno;
 613                         goto errout;
 614                 }
 615
 616 #if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
 617                 retval = fchflags (fd, UF_NODUMP|UF_IMMUTABLE);
 618 #else
 619 #if HAVE_EXT2_IOCTLS
 620                 if (ioctl(fd, EXT2_IOC_GETFLAGS, &f) < 0) {
 621                         retval = errno;
 622                         goto errout;
 623                 }
 624                 f |= EXT2_NODUMP_FL | EXT2_IMMUTABLE_FL;
 625                 retval = ioctl(fd, EXT2_IOC_SETFLAGS, &f);
 626 #endif
 627 #endif
 628                 if (retval) {
 629                         retval = errno;
 630                         goto errout;
 631                 }
 632
 633                 if (close(fd) < 0) {
 634                         retval = errno;
 635                         fd = -1;
 636                         goto errout;
 637                 }
 638                 journal_ino = st.st_ino;
 639                 memset(fs->super->s_jnl_blocks, 0,
 640                        sizeof(fs->super->s_jnl_blocks));
 641         } else {
 642                 if ((mount_flags & EXT2_MF_BUSY) &&
 643                     !(fs->flags & EXT2_FLAG_EXCLUSIVE)) {
 644                         retval = EBUSY;
 645                         goto errout;
 646                 }
 647                 journal_ino = EXT2_JOURNAL_INO;
 648                 if ((retval = write_journal_inode(fs, journal_ino,
 649                                                   num_blocks, goal, flags)))
 650                         return retval;
 651         }
 652
 653         fs->super->s_journal_inum = journal_ino;
 654         fs->super->s_journal_dev = 0;
 655         memset(fs->super->s_journal_uuid, 0,
 656                sizeof(fs->super->s_journal_uuid));
 657         fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 658
 659         ext2fs_mark_super_dirty(fs);
 660         return 0;
 661 errout:
 662         if (fd >= 0)
 663                 close(fd);
 664         return retval;
 665 }
 666
 667 errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t num_blocks, int flags)
 668 {
 669         return ext2fs_add_journal_inode2(fs, num_blocks, ~0ULL, flags);
 670 }
 671
 672
 673 #ifdef DEBUG
 674 main(int argc, char **argv)
 675 {
 676         errcode_t       retval;
 677         char            *device_name;
 678         ext2_filsys     fs;
 679
 680         if (argc < 2) {
 681                 fprintf(stderr, "Usage: %s filesystem\n", argv[0]);
 682                 exit(1);
 683         }
 684         device_name = argv[1];
 685
 686         retval = ext2fs_open (device_name, EXT2_FLAG_RW, 0, 0,
 687                               unix_io_manager, &fs);
 688         if (retval) {
 689                 com_err(argv[0], retval, "while opening %s", device_name);
 690                 exit(1);
 691         }
 692
 693         retval = ext2fs_add_journal_inode(fs, JFS_MIN_JOURNAL_BLOCKS, 0);
 694         if (retval) {
 695                 com_err(argv[0], retval, "while adding journal to %s",
 696                         device_name);
 697                 exit(1);
 698         }
 699         retval = ext2fs_flush(fs);
 700         if (retval) {
 701                 printf("Warning, had trouble writing out superblocks.\n");
 702         }
 703         ext2fs_close_free(&fs);
 704         exit(0);
 705
 706 }
 707 #endif