e2fsprogs/old_e2fsprogs/ext2fs/mkjournal.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * mkjournal.c --- make a journal for a filesystem
   4  *
   5  * Copyright (C) 2000 Theodore Ts'o.
   6  *
   7  * %Begin-Header%
   8  * This file may be redistributed under the terms of the GNU Public
   9  * License.
  10  * %End-Header%
  11  */
  12
  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
  36 #include "ext2_fs.h"
  37 #include "../e2p/e2p.h"
  38 #include "../e2fsck.h"
  39 #include "ext2fs.h"
  40 #include "kernel-jbd.h"
  41
  42 /*
  43  * This function automatically sets up the journal superblock and
  44  * returns it as an allocated block.
  45  */
  46 errcode_t ext2fs_create_journal_superblock(ext2_filsys fs,
  47                                            __u32 size, int flags,
  48                                            char  **ret_jsb)
  49 {
  50         errcode_t               retval;
  51         journal_superblock_t    *jsb;
  52
  53         if (size < 1024)
  54                 return EXT2_ET_JOURNAL_TOO_SMALL;
  55
  56         if ((retval = ext2fs_get_mem(fs->blocksize, &jsb)))
  57                 return retval;
  58
  59         memset (jsb, 0, fs->blocksize);
  60
  61         jsb->s_header.h_magic = htonl(JFS_MAGIC_NUMBER);
  62         if (flags & EXT2_MKJOURNAL_V1_SUPER)
  63                 jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V1);
  64         else
  65                 jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V2);
  66         jsb->s_blocksize = htonl(fs->blocksize);
  67         jsb->s_maxlen = htonl(size);
  68         jsb->s_nr_users = htonl(1);
  69         jsb->s_first = htonl(1);
  70         jsb->s_sequence = htonl(1);
  71         memcpy(jsb->s_uuid, fs->super->s_uuid, sizeof(fs->super->s_uuid));
  72         /*
  73          * If we're creating an external journal device, we need to
  74          * adjust these fields.
  75          */
  76         if (fs->super->s_feature_incompat &
  77             EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
  78                 jsb->s_nr_users = 0;
  79                 if (fs->blocksize == 1024)
  80                         jsb->s_first = htonl(3);
  81                 else
  82                         jsb->s_first = htonl(2);
  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 size, int flags)
  96 {
  97         errcode_t       retval;
  98         char            *buf = NULL;
  99         int             fd, ret_size;
 100         blk_t           i;
 101
 102         if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf)))
 103                 return retval;
 104
 105         /* Open the device or journal file */
 106         if ((fd = open(filename, O_WRONLY)) < 0) {
 107                 retval = errno;
 108                 goto errout;
 109         }
 110
 111         /* Write the superblock out */
 112         retval = EXT2_ET_SHORT_WRITE;
 113         ret_size = write(fd, buf, fs->blocksize);
 114         if (ret_size < 0) {
 115                 retval = errno;
 116                 goto errout;
 117         }
 118         if (ret_size != (int) fs->blocksize)
 119                 goto errout;
 120         memset(buf, 0, fs->blocksize);
 121
 122         for (i = 1; i < size; i++) {
 123                 ret_size = write(fd, buf, fs->blocksize);
 124                 if (ret_size < 0) {
 125                         retval = errno;
 126                         goto errout;
 127                 }
 128                 if (ret_size != (int) fs->blocksize)
 129                         goto errout;
 130         }
 131         close(fd);
 132
 133         retval = 0;
 134 errout:
 135         ext2fs_free_mem(&buf);
 136         return retval;
 137 }
 138
 139 /*
 140  * Helper function for creating the journal using direct I/O routines
 141  */
 142 struct mkjournal_struct {
 143         int             num_blocks;
 144         int             newblocks;
 145         char            *buf;
 146         errcode_t       err;
 147 };
 148
 149 static int mkjournal_proc(ext2_filsys   fs,
 150                            blk_t        *blocknr,
 151                            e2_blkcnt_t  blockcnt,
 152                            blk_t        ref_block EXT2FS_ATTR((unused)),
 153                            int          ref_offset EXT2FS_ATTR((unused)),
 154                            void         *priv_data)
 155 {
 156         struct mkjournal_struct *es = (struct mkjournal_struct *) priv_data;
 157         blk_t   new_blk;
 158         static blk_t    last_blk = 0;
 159         errcode_t       retval;
 160
 161         if (*blocknr) {
 162                 last_blk = *blocknr;
 163                 return 0;
 164         }
 165         retval = ext2fs_new_block(fs, last_blk, 0, &new_blk);
 166         if (retval) {
 167                 es->err = retval;
 168                 return BLOCK_ABORT;
 169         }
 170         if (blockcnt > 0)
 171                 es->num_blocks--;
 172
 173         es->newblocks++;
 174         retval = io_channel_write_blk(fs->io, new_blk, 1, es->buf);
 175
 176         if (blockcnt == 0)
 177                 memset(es->buf, 0, fs->blocksize);
 178
 179         if (retval) {
 180                 es->err = retval;
 181                 return BLOCK_ABORT;
 182         }
 183         *blocknr = new_blk;
 184         last_blk = new_blk;
 185         ext2fs_block_alloc_stats(fs, new_blk, +1);
 186
 187         if (es->num_blocks == 0)
 188                 return (BLOCK_CHANGED | BLOCK_ABORT);
 189         else
 190                 return BLOCK_CHANGED;
 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(NULL);
 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         retval = ext2fs_check_mount_point(fs->device_name, &mount_flags,
 325                                                jfile, sizeof(jfile)-10);
 326         if (retval)
 327                 return retval;
 328
 329         if (mount_flags & EXT2_MF_MOUNTED) {
 330                 strcat(jfile, "/.journal");
 331
 332                 /*
 333                  * If .../.journal already exists, make sure any
 334                  * immutable or append-only flags are cleared.
 335                  */
 336 #if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
 337                 (void) chflags (jfile, 0);
 338 #else
 339 #if HAVE_EXT2_IOCTLS
 340                 fd = open(jfile, O_RDONLY);
 341                 if (fd >= 0) {
 342                         f = 0;
 343                         ioctl(fd, EXT2_IOC_SETFLAGS, &f);
 344                         close(fd);
 345                 }
 346 #endif
 347 #endif
 348
 349                 /* Create the journal file */
 350                 if ((fd = open(jfile, O_CREAT|O_WRONLY, 0600)) < 0)
 351                         return errno;
 352
 353                 if ((retval = write_journal_file(fs, jfile, size, flags)))
 354                         goto errout;
 355
 356                 /* Get inode number of the journal file */
 357                 if (fstat(fd, &st) < 0)
 358                         goto errout;
 359
 360 #if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
 361                 retval = fchflags (fd, UF_NODUMP|UF_IMMUTABLE);
 362 #else
 363 #if HAVE_EXT2_IOCTLS
 364                 f = EXT2_NODUMP_FL | EXT2_IMMUTABLE_FL;
 365                 retval = ioctl(fd, EXT2_IOC_SETFLAGS, &f);
 366 #endif
 367 #endif
 368                 if (retval)
 369                         goto errout;
 370
 371                 close(fd);
 372                 journal_ino = st.st_ino;
 373         } else {
 374                 journal_ino = EXT2_JOURNAL_INO;
 375                 if ((retval = write_journal_inode(fs, journal_ino,
 376                                                   size, flags)))
 377                         return retval;
 378         }
 379
 380         fs->super->s_journal_inum = journal_ino;
 381         fs->super->s_journal_dev = 0;
 382         memset(fs->super->s_journal_uuid, 0,
 383                sizeof(fs->super->s_journal_uuid));
 384         fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 385
 386         ext2fs_mark_super_dirty(fs);
 387         return 0;
 388 errout:
 389         close(fd);
 390         return retval;
 391 }
 392
 393 #ifdef DEBUG
 394 main(int argc, char **argv)
 395 {
 396         errcode_t       retval;
 397         char            *device_name;
 398         ext2_filsys     fs;
 399
 400         if (argc < 2) {
 401                 fprintf(stderr, "Usage: %s filesystem\n", argv[0]);
 402                 exit(1);
 403         }
 404         device_name = argv[1];
 405
 406         retval = ext2fs_open (device_name, EXT2_FLAG_RW, 0, 0,
 407                               unix_io_manager, &fs);
 408         if (retval) {
 409                 com_err(argv[0], retval, "while opening %s", device_name);
 410                 exit(1);
 411         }
 412
 413         retval = ext2fs_add_journal_inode(fs, 1024);
 414         if (retval) {
 415                 com_err(argv[0], retval, "while adding journal to %s",
 416                         device_name);
 417                 exit(1);
 418         }
 419         retval = ext2fs_flush(fs);
 420         if (retval) {
 421                 printf("Warning, had trouble writing out superblocks.\n");
 422         }
 423         ext2fs_close(fs);
 424         exit(0);
 425 }
 426 #endif