e2fsprogs/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 "../e2fsck.h"
  38 #include "ext2fs.h"
  39 #include "kernel-jbd.h"
  40
  41 /*
  42  * This function automatically sets up the journal superblock and
  43  * returns it as an allocated block.
  44  */
  45 errcode_t ext2fs_create_journal_superblock(ext2_filsys fs,
  46                                            __u32 size, int flags,
  47                                            char  **ret_jsb)
  48 {
  49         errcode_t               retval;
  50         journal_superblock_t    *jsb;
  51
  52         if (size < 1024)
  53                 return EXT2_ET_JOURNAL_TOO_SMALL;
  54
  55         if ((retval = ext2fs_get_mem(fs->blocksize, &jsb)))
  56                 return retval;
  57
  58         memset (jsb, 0, fs->blocksize);
  59
  60         jsb->s_header.h_magic = htonl(JFS_MAGIC_NUMBER);
  61         if (flags & EXT2_MKJOURNAL_V1_SUPER)
  62                 jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V1);
  63         else
  64                 jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V2);
  65         jsb->s_blocksize = htonl(fs->blocksize);
  66         jsb->s_maxlen = htonl(size);
  67         jsb->s_nr_users = htonl(1);
  68         jsb->s_first = htonl(1);
  69         jsb->s_sequence = htonl(1);
  70         memcpy(jsb->s_uuid, fs->super->s_uuid, sizeof(fs->super->s_uuid));
  71         /*
  72          * If we're creating an external journal device, we need to
  73          * adjust these fields.
  74          */
  75         if (fs->super->s_feature_incompat &
  76             EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
  77                 jsb->s_nr_users = 0;
  78                 if (fs->blocksize == 1024)
  79                         jsb->s_first = htonl(3);
  80                 else
  81                         jsb->s_first = htonl(2);
  82         }
  83
  84         *ret_jsb = (char *) jsb;
  85         return 0;
  86 }
  87
  88 /*
  89  * This function writes a journal using POSIX routines.  It is used
  90  * for creating external journals and creating journals on live
  91  * filesystems.
  92  */
  93 static errcode_t write_journal_file(ext2_filsys fs, char *filename,
  94                                     blk_t size, int flags)
  95 {
  96         errcode_t       retval;
  97         char            *buf = 0;
  98         int             fd, ret_size;
  99         blk_t           i;
 100
 101         if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf)))
 102                 return retval;
 103
 104         /* Open the device or journal file */
 105         if ((fd = open(filename, O_WRONLY)) < 0) {
 106                 retval = errno;
 107                 goto errout;
 108         }
 109
 110         /* Write the superblock out */
 111         retval = EXT2_ET_SHORT_WRITE;
 112         ret_size = write(fd, buf, fs->blocksize);
 113         if (ret_size < 0) {
 114                 retval = errno;
 115                 goto errout;
 116         }
 117         if (ret_size != (int) fs->blocksize)
 118                 goto errout;
 119         memset(buf, 0, fs->blocksize);
 120
 121         for (i = 1; i < size; i++) {
 122                 ret_size = write(fd, buf, fs->blocksize);
 123                 if (ret_size < 0) {
 124                         retval = errno;
 125                         goto errout;
 126                 }
 127                 if (ret_size != (int) fs->blocksize)
 128                         goto errout;
 129         }
 130         close(fd);
 131
 132         retval = 0;
 133 errout:
 134         ext2fs_free_mem(&buf);
 135         return retval;
 136 }
 137
 138 /*
 139  * Helper function for creating the journal using direct I/O routines
 140  */
 141 struct mkjournal_struct {
 142         int             num_blocks;
 143         int             newblocks;
 144         char            *buf;
 145         errcode_t       err;
 146 };
 147
 148 static int mkjournal_proc(ext2_filsys   fs,
 149                            blk_t        *blocknr,
 150                            e2_blkcnt_t  blockcnt,
 151                            blk_t        ref_block EXT2FS_ATTR((unused)),
 152                            int          ref_offset EXT2FS_ATTR((unused)),
 153                            void         *priv_data)
 154 {
 155         struct mkjournal_struct *es = (struct mkjournal_struct *) priv_data;
 156         blk_t   new_blk;
 157         static blk_t    last_blk = 0;
 158         errcode_t       retval;
 159
 160         if (*blocknr) {
 161                 last_blk = *blocknr;
 162                 return 0;
 163         }
 164         retval = ext2fs_new_block(fs, last_blk, 0, &new_blk);
 165         if (retval) {
 166                 es->err = retval;
 167                 return BLOCK_ABORT;
 168         }
 169         if (blockcnt > 0)
 170                 es->num_blocks--;
 171
 172         es->newblocks++;
 173         retval = io_channel_write_blk(fs->io, new_blk, 1, es->buf);
 174
 175         if (blockcnt == 0)
 176                 memset(es->buf, 0, fs->blocksize);
 177
 178         if (retval) {
 179                 es->err = retval;
 180                 return BLOCK_ABORT;
 181         }
 182         *blocknr = new_blk;
 183         last_blk = new_blk;
 184         ext2fs_block_alloc_stats(fs, new_blk, +1);
 185
 186         if (es->num_blocks == 0)
 187                 return (BLOCK_CHANGED | BLOCK_ABORT);
 188         else
 189                 return BLOCK_CHANGED;
 190
 191 }
 192
 193 /*
 194  * This function creates a journal using direct I/O routines.
 195  */
 196 static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino,
 197                                      blk_t size, int flags)
 198 {
 199         char                    *buf;
 200         errcode_t               retval;
 201         struct ext2_inode       inode;
 202         struct mkjournal_struct es;
 203
 204         if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf)))
 205                 return retval;
 206
 207         if ((retval = ext2fs_read_bitmaps(fs)))
 208                 return retval;
 209
 210         if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
 211                 return retval;
 212
 213         if (inode.i_blocks > 0)
 214                 return EEXIST;
 215
 216         es.num_blocks = size;
 217         es.newblocks = 0;
 218         es.buf = buf;
 219         es.err = 0;
 220
 221         retval = ext2fs_block_iterate2(fs, journal_ino, BLOCK_FLAG_APPEND,
 222                                        0, mkjournal_proc, &es);
 223         if (es.err) {
 224                 retval = es.err;
 225                 goto errout;
 226         }
 227
 228         if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
 229                 goto errout;
 230
 231         inode.i_size += fs->blocksize * size;
 232         inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
 233         inode.i_mtime = inode.i_ctime = time(0);
 234         inode.i_links_count = 1;
 235         inode.i_mode = LINUX_S_IFREG | 0600;
 236
 237         if ((retval = ext2fs_write_inode(fs, journal_ino, &inode)))
 238                 goto errout;
 239         retval = 0;
 240
 241         memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
 242         fs->super->s_jnl_blocks[16] = inode.i_size;
 243         fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
 244         ext2fs_mark_super_dirty(fs);
 245
 246 errout:
 247         ext2fs_free_mem(&buf);
 248         return retval;
 249 }
 250
 251 /*
 252  * This function adds a journal device to a filesystem
 253  */
 254 errcode_t ext2fs_add_journal_device(ext2_filsys fs, ext2_filsys journal_dev)
 255 {
 256         struct stat     st;
 257         errcode_t       retval;
 258         char            buf[1024];
 259         journal_superblock_t    *jsb;
 260         int             start;
 261         __u32           i, nr_users;
 262
 263         /* Make sure the device exists and is a block device */
 264         if (stat(journal_dev->device_name, &st) < 0)
 265                 return errno;
 266
 267         if (!S_ISBLK(st.st_mode))
 268                 return EXT2_ET_JOURNAL_NOT_BLOCK; /* Must be a block device */
 269
 270         /* Get the journal superblock */
 271         start = 1;
 272         if (journal_dev->blocksize == 1024)
 273                 start++;
 274         if ((retval = io_channel_read_blk(journal_dev->io, start, -1024, buf)))
 275                 return retval;
 276
 277         jsb = (journal_superblock_t *) buf;
 278         if ((jsb->s_header.h_magic != (unsigned) ntohl(JFS_MAGIC_NUMBER)) ||
 279             (jsb->s_header.h_blocktype != (unsigned) ntohl(JFS_SUPERBLOCK_V2)))
 280                 return EXT2_ET_NO_JOURNAL_SB;
 281
 282         if (ntohl(jsb->s_blocksize) != (unsigned long) fs->blocksize)
 283                 return EXT2_ET_UNEXPECTED_BLOCK_SIZE;
 284
 285         /* Check and see if this filesystem has already been added */
 286         nr_users = ntohl(jsb->s_nr_users);
 287         for (i=0; i < nr_users; i++) {
 288                 if (memcmp(fs->super->s_uuid,
 289                            &jsb->s_users[i*16], 16) == 0)
 290                         break;
 291         }
 292         if (i >= nr_users) {
 293                 memcpy(&jsb->s_users[nr_users*16],
 294                        fs->super->s_uuid, 16);
 295                 jsb->s_nr_users = htonl(nr_users+1);
 296         }
 297
 298         /* Writeback the journal superblock */
 299         if ((retval = io_channel_write_blk(journal_dev->io, start, -1024, buf)))
 300                 return retval;
 301
 302         fs->super->s_journal_inum = 0;
 303         fs->super->s_journal_dev = st.st_rdev;
 304         memcpy(fs->super->s_journal_uuid, jsb->s_uuid,
 305                sizeof(fs->super->s_journal_uuid));
 306         fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 307         ext2fs_mark_super_dirty(fs);
 308         return 0;
 309 }
 310
 311 /*
 312  * This function adds a journal inode to a filesystem, using either
 313  * POSIX routines if the filesystem is mounted, or using direct I/O
 314  * functions if it is not.
 315  */
 316 errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t size, int flags)
 317 {
 318         errcode_t               retval;
 319         ext2_ino_t              journal_ino;
 320         struct stat             st;
 321         char                    jfile[1024];
 322         int                     fd, mount_flags, f;
 323
 324         if ((retval = ext2fs_check_mount_point(fs->device_name, &mount_flags,
 325                                                jfile, sizeof(jfile)-10)))
 326                 return retval;
 327
 328         if (mount_flags & EXT2_MF_MOUNTED) {
 329                 strcat(jfile, "/.journal");
 330
 331                 /*
 332                  * If .../.journal already exists, make sure any
 333                  * immutable or append-only flags are cleared.
 334                  */
 335 #if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
 336                 (void) chflags (jfile, 0);
 337 #else
 338 #if HAVE_EXT2_IOCTLS
 339                 fd = open(jfile, O_RDONLY);
 340                 if (fd >= 0) {
 341                         f = 0;
 342                         ioctl(fd, EXT2_IOC_SETFLAGS, &f);
 343                         close(fd);
 344                 }
 345 #endif
 346 #endif
 347
 348                 /* Create the journal file */
 349                 if ((fd = open(jfile, O_CREAT|O_WRONLY, 0600)) < 0)
 350                         return errno;
 351
 352                 if ((retval = write_journal_file(fs, jfile, size, flags)))
 353                         goto errout;
 354
 355                 /* Get inode number of the journal file */
 356                 if (fstat(fd, &st) < 0)
 357                         goto errout;
 358
 359 #if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
 360                 retval = fchflags (fd, UF_NODUMP|UF_IMMUTABLE);
 361 #else
 362 #if HAVE_EXT2_IOCTLS
 363                 f = EXT2_NODUMP_FL | EXT2_IMMUTABLE_FL;
 364                 retval = ioctl(fd, EXT2_IOC_SETFLAGS, &f);
 365 #endif
 366 #endif
 367                 if (retval)
 368                         goto errout;
 369
 370                 close(fd);
 371                 journal_ino = st.st_ino;
 372         } else {
 373                 journal_ino = EXT2_JOURNAL_INO;
 374                 if ((retval = write_journal_inode(fs, journal_ino,
 375                                                   size, flags)))
 376                         return retval;
 377         }
 378
 379         fs->super->s_journal_inum = journal_ino;
 380         fs->super->s_journal_dev = 0;
 381         memset(fs->super->s_journal_uuid, 0,
 382                sizeof(fs->super->s_journal_uuid));
 383         fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 384
 385         ext2fs_mark_super_dirty(fs);
 386         return 0;
 387 errout:
 388         close(fd);
 389         return retval;
 390 }
 391
 392 #ifdef DEBUG
 393 main(int argc, char **argv)
 394 {
 395         errcode_t       retval;
 396         char            *device_name;
 397         ext2_filsys     fs;
 398
 399         if (argc < 2) {
 400                 fprintf(stderr, "Usage: %s filesystem\n", argv[0]);
 401                 exit(1);
 402         }
 403         device_name = argv[1];
 404
 405         retval = ext2fs_open (device_name, EXT2_FLAG_RW, 0, 0,
 406                               unix_io_manager, &fs);
 407         if (retval) {
 408                 com_err(argv[0], retval, "while opening %s", device_name);
 409                 exit(1);
 410         }
 411
 412         retval = ext2fs_add_journal_inode(fs, 1024);
 413         if (retval) {
 414                 com_err(argv[0], retval, "while adding journal to %s",
 415                         device_name);
 416                 exit(1);
 417         }
 418         retval = ext2fs_flush(fs);
 419         if (retval) {
 420                 printf("Warning, had trouble writing out superblocks.\n");
 421         }
 422         ext2fs_close(fs);
 423         exit(0);
 424
 425 }
 426 #endif