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 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, (void **) &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             i, fd, ret_size;
  98
  99         if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf)))
 100                 return retval;
 101
 102         /* Open the device or journal file */
 103         if ((fd = open(filename, O_WRONLY)) < 0) {
 104                 retval = errno;
 105                 goto errout;
 106         }
 107
 108         /* Write the superblock out */
 109         retval = EXT2_ET_SHORT_WRITE;
 110         ret_size = write(fd, buf, fs->blocksize);
 111         if (ret_size < 0) {
 112                 retval = errno;
 113                 goto errout;
 114         }
 115         if (ret_size != fs->blocksize)
 116                 goto errout;
 117         memset(buf, 0, fs->blocksize);
 118
 119         for (i = 1; i < size; i++) {
 120                 ret_size = write(fd, buf, fs->blocksize);
 121                 if (ret_size < 0) {
 122                         retval = errno;
 123                         goto errout;
 124                 }
 125                 if (ret_size != fs->blocksize)
 126                         goto errout;
 127         }
 128         close(fd);
 129
 130         retval = 0;
 131 errout:
 132         ext2fs_free_mem((void **) &buf);
 133         return retval;
 134 }
 135
 136 /*
 137  * Helper function for creating the journal using direct I/O routines
 138  */
 139 struct mkjournal_struct {
 140         int             num_blocks;
 141         int             newblocks;
 142         char            *buf;
 143         errcode_t       err;
 144 };
 145
 146 static int mkjournal_proc(ext2_filsys           fs,
 147                            blk_t                *blocknr,
 148                            e2_blkcnt_t          blockcnt,
 149                            blk_t                ref_block,
 150                            int                  ref_offset,
 151                            void                 *priv_data)
 152 {
 153         struct mkjournal_struct *es = (struct mkjournal_struct *) priv_data;
 154         blk_t   new_blk;
 155         static blk_t    last_blk = 0;
 156         errcode_t       retval;
 157         int             group;
 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_mark_block_bitmap(fs->block_map, new_blk);
 184         ext2fs_mark_bb_dirty(fs);
 185         group = ext2fs_group_of_blk(fs, new_blk);
 186         fs->group_desc[group].bg_free_blocks_count--;
 187         fs->super->s_free_blocks_count--;
 188         ext2fs_mark_super_dirty(fs);
 189
 190         if (es->num_blocks == 0)
 191                 return (BLOCK_CHANGED | BLOCK_ABORT);
 192         else
 193                 return BLOCK_CHANGED;
 194
 195 }
 196
 197 /*
 198  * This function creates a journal using direct I/O routines.
 199  */
 200 static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino,
 201                                      blk_t size, int flags)
 202 {
 203         char                    *buf;
 204         errcode_t               retval;
 205         struct ext2_inode       inode;
 206         struct mkjournal_struct es;
 207
 208         if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf)))
 209                 return retval;
 210
 211         if ((retval = ext2fs_read_bitmaps(fs)))
 212                 return retval;
 213
 214         if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
 215                 return retval;
 216
 217         if (inode.i_blocks > 0)
 218                 return EEXIST;
 219
 220         es.num_blocks = size;
 221         es.newblocks = 0;
 222         es.buf = buf;
 223         es.err = 0;
 224
 225         retval = ext2fs_block_iterate2(fs, journal_ino, BLOCK_FLAG_APPEND,
 226                                        0, mkjournal_proc, &es);
 227         if (es.err) {
 228                 retval = es.err;
 229                 goto errout;
 230         }
 231
 232         if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
 233                 goto errout;
 234
 235         inode.i_size += fs->blocksize * size;
 236         inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
 237         inode.i_mtime = inode.i_ctime = time(0);
 238         inode.i_links_count = 1;
 239         inode.i_mode = LINUX_S_IFREG | 0600;
 240
 241         if ((retval = ext2fs_write_inode(fs, journal_ino, &inode)))
 242                 goto errout;
 243         retval = 0;
 244
 245 errout:
 246         ext2fs_free_mem((void **) &buf);
 247         return retval;
 248 }
 249
 250 /*
 251  * This function adds a journal device to a filesystem
 252  */
 253 errcode_t ext2fs_add_journal_device(ext2_filsys fs, ext2_filsys journal_dev)
 254 {
 255         struct stat     st;
 256         errcode_t       retval;
 257         char            buf[1024];
 258         journal_superblock_t    *jsb;
 259         int             i, start;
 260         __u32           nr_users;
 261
 262         /* Make sure the device exists and is a block device */
 263         if (stat(journal_dev->device_name, &st) < 0)
 264                 return errno;
 265
 266         if (!S_ISBLK(st.st_mode))
 267                 return EXT2_ET_JOURNAL_NOT_BLOCK; /* Must be a block device */
 268
 269         /* Get the journal superblock */
 270         start = 1;
 271         if (journal_dev->blocksize == 1024)
 272                 start++;
 273         if ((retval = io_channel_read_blk(journal_dev->io, start, -1024, buf)))
 274                 return retval;
 275
 276         jsb = (journal_superblock_t *) buf;
 277         if ((jsb->s_header.h_magic != (unsigned) ntohl(JFS_MAGIC_NUMBER)) ||
 278             (jsb->s_header.h_blocktype != (unsigned) ntohl(JFS_SUPERBLOCK_V2)))
 279                 return EXT2_ET_NO_JOURNAL_SB;
 280
 281         if (ntohl(jsb->s_blocksize) != fs->blocksize)
 282                 return EXT2_ET_UNEXPECTED_BLOCK_SIZE;
 283
 284         /* Check and see if this filesystem has already been added */
 285         nr_users = ntohl(jsb->s_nr_users);
 286         for (i=0; i < nr_users; i++) {
 287                 if (memcmp(fs->super->s_uuid,
 288                            &jsb->s_users[i*16], 16) == 0)
 289                         break;
 290         }
 291         if (i >= nr_users) {
 292                 memcpy(&jsb->s_users[nr_users*16],
 293                        fs->super->s_uuid, 16);
 294                 jsb->s_nr_users = htonl(nr_users+1);
 295         }
 296
 297         /* Writeback the journal superblock */
 298         if ((retval = io_channel_write_blk(journal_dev->io, start, -1024, buf)))
 299                 return retval;
 300
 301         fs->super->s_journal_inum = 0;
 302         fs->super->s_journal_dev = st.st_rdev;
 303         memcpy(fs->super->s_journal_uuid, jsb->s_uuid,
 304                sizeof(fs->super->s_journal_uuid));
 305         fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 306         ext2fs_mark_super_dirty(fs);
 307         return 0;
 308 }
 309
 310 /*
 311  * This function adds a journal inode to a filesystem, using either
 312  * POSIX routines if the filesystem is mounted, or using direct I/O
 313  * functions if it is not.
 314  */
 315 errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t size, int flags)
 316 {
 317         errcode_t               retval;
 318         ext2_ino_t              journal_ino;
 319         struct stat             st;
 320         char                    jfile[1024];
 321         int                     fd, mount_flags, f;
 322
 323         if ((retval = ext2fs_check_mount_point(fs->device_name, &mount_flags,
 324                                                jfile, sizeof(jfile)-10)))
 325                 return retval;
 326
 327         if (mount_flags & EXT2_MF_MOUNTED) {
 328                 strcat(jfile, "/.journal");
 329
 330                 /* Create the journal file */
 331                 if ((fd = open(jfile, O_CREAT|O_WRONLY, 0600)) < 0)
 332                         return errno;
 333
 334                 if ((retval = write_journal_file(fs, jfile, size, flags)))
 335                         goto errout;
 336
 337                 /* Get inode number of the journal file */
 338                 if (fstat(fd, &st) < 0)
 339                         goto errout;
 340
 341 #if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
 342                 retval = fchflags (fd, UF_NODUMP|UF_IMMUTABLE);
 343 #else
 344 #if HAVE_EXT2_IOCTLS
 345                 f = EXT2_NODUMP_FL | EXT2_IMMUTABLE_FL;;
 346                 retval = ioctl(fd, EXT2_IOC_SETFLAGS, &f);
 347 #endif
 348 #endif
 349                 if (retval)
 350                         goto errout;
 351
 352                 close(fd);
 353                 journal_ino = st.st_ino;
 354         } else {
 355                 journal_ino = EXT2_JOURNAL_INO;
 356                 if ((retval = write_journal_inode(fs, journal_ino,
 357                                                   size, flags)))
 358                         return retval;
 359         }
 360
 361         fs->super->s_journal_inum = journal_ino;
 362         fs->super->s_journal_dev = 0;
 363         memset(fs->super->s_journal_uuid, 0,
 364                sizeof(fs->super->s_journal_uuid));
 365         fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 366
 367         ext2fs_mark_super_dirty(fs);
 368         return 0;
 369 errout:
 370         close(fd);
 371         return retval;
 372 }
 373
 374 #ifdef DEBUG
 375 main(int argc, char **argv)
 376 {
 377         errcode_t       retval;
 378         char            *device_name;
 379         ext2_filsys     fs;
 380
 381         if (argc < 2) {
 382                 fprintf(stderr, "Usage: %s filesystem\n", argv[0]);
 383                 exit(1);
 384         }
 385         device_name = argv[1];
 386
 387         retval = ext2fs_open (device_name, EXT2_FLAG_RW, 0, 0,
 388                               unix_io_manager, &fs);
 389         if (retval) {
 390                 com_err(argv[0], retval, "while opening %s", device_name);
 391                 exit(1);
 392         }
 393
 394         retval = ext2fs_add_journal_inode(fs, 1024);
 395         if (retval) {
 396                 com_err(argv[0], retval, "while adding journal to %s",
 397                         device_name);
 398                 exit(1);
 399         }
 400         retval = ext2fs_flush(fs);
 401         if (retval) {
 402                 printf("Warning, had trouble writing out superblocks.\n");
 403         }
 404         ext2fs_close(fs);
 405         exit(0);
 406
 407 }
 408 #endif