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_NETINET_IN_H
  29 #include <netinet/in.h>
  30 #endif
  31
  32 #if EXT2_FLAT_INCLUDES
  33 #include "ext2_fs.h"
  34 #else
  35 #include <linux/ext2_fs.h>
  36 #endif
  37
  38 #include "e2p/e2p.h"
  39 #include "ext2fs.h"
  40 #include "jfs_user.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, (void **) &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                 jsb->s_first = htonl(1);
  80         }
  81
  82         *ret_jsb = (char *) jsb;
  83         return 0;
  84 }
  85
  86 /*
  87  * This function writes a journal using POSIX routines.  It is used
  88  * for creating external journals and creating journals on live
  89  * filesystems.
  90  */
  91 static errcode_t write_journal_file(ext2_filsys fs, char *filename,
  92                                     blk_t size, int flags)
  93 {
  94         errcode_t       retval;
  95         char            *buf = 0;
  96         int             i, fd, ret_size;
  97
  98         if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf)))
  99                 return retval;
 100
 101         /* Open the device or journal file */
 102         if ((fd = open(filename, O_WRONLY)) < 0) {
 103                 retval = errno;
 104                 goto errout;
 105         }
 106
 107         /* Write the superblock out */
 108         retval = EXT2_ET_SHORT_WRITE;
 109         ret_size = write(fd, buf, fs->blocksize);
 110         if (ret_size < 0) {
 111                 retval = errno;
 112                 goto errout;
 113         }
 114         if (ret_size != fs->blocksize)
 115                 goto errout;
 116         memset(buf, 0, fs->blocksize);
 117
 118         for (i = 1; i < size; i++) {
 119                 ret_size = write(fd, buf, fs->blocksize);
 120                 if (ret_size < 0) {
 121                         retval = errno;
 122                         goto errout;
 123                 }
 124                 if (ret_size != fs->blocksize)
 125                         goto errout;
 126         }
 127         close(fd);
 128
 129         retval = 0;
 130 errout:
 131         ext2fs_free_mem((void **) &buf);
 132         return retval;
 133 }
 134
 135 /*
 136  * Helper function for creating the journal using direct I/O routines
 137  */
 138 struct mkjournal_struct {
 139         int             num_blocks;
 140         int             newblocks;
 141         char            *buf;
 142         errcode_t       err;
 143 };
 144
 145 static int mkjournal_proc(ext2_filsys           fs,
 146                            blk_t                *blocknr,
 147                            e2_blkcnt_t          blockcnt,
 148                            blk_t                ref_block,
 149                            int                  ref_offset,
 150                            void                 *priv_data)
 151 {
 152         struct mkjournal_struct *es = (struct mkjournal_struct *) priv_data;
 153         blk_t   new_blk;
 154         static blk_t    last_blk = 0;
 155         errcode_t       retval;
 156         int             group;
 157
 158         if (*blocknr) {
 159                 last_blk = *blocknr;
 160                 return 0;
 161         }
 162         retval = ext2fs_new_block(fs, last_blk, 0, &new_blk);
 163         if (retval) {
 164                 es->err = retval;
 165                 return BLOCK_ABORT;
 166         }
 167         if (blockcnt > 0)
 168                 es->num_blocks--;
 169
 170         es->newblocks++;
 171         retval = io_channel_write_blk(fs->io, new_blk, 1, es->buf);
 172
 173         if (blockcnt == 0)
 174                 memset(es->buf, 0, fs->blocksize);
 175
 176         if (retval) {
 177                 es->err = retval;
 178                 return BLOCK_ABORT;
 179         }
 180         *blocknr = new_blk;
 181         ext2fs_mark_block_bitmap(fs->block_map, new_blk);
 182         ext2fs_mark_bb_dirty(fs);
 183         group = ext2fs_group_of_blk(fs, new_blk);
 184         fs->group_desc[group].bg_free_blocks_count--;
 185         fs->super->s_free_blocks_count--;
 186         ext2fs_mark_super_dirty(fs);
 187
 188         if (es->num_blocks == 0)
 189                 return (BLOCK_CHANGED | BLOCK_ABORT);
 190         else
 191                 return BLOCK_CHANGED;
 192
 193 }
 194
 195 /*
 196  * This function creates a journal using direct I/O routines.
 197  */
 198 static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino,
 199                                      blk_t size, int flags)
 200 {
 201         char                    *buf;
 202         errcode_t               retval;
 203         struct ext2_inode       inode;
 204         struct mkjournal_struct es;
 205
 206         if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf)))
 207                 return retval;
 208
 209         if ((retval = ext2fs_read_bitmaps(fs)))
 210                 return retval;
 211
 212         if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
 213                 return retval;
 214
 215         if (inode.i_blocks > 0)
 216                 return EEXIST;
 217
 218         es.num_blocks = size;
 219         es.newblocks = 0;
 220         es.buf = buf;
 221         es.err = 0;
 222
 223         retval = ext2fs_block_iterate2(fs, journal_ino, BLOCK_FLAG_APPEND,
 224                                        0, mkjournal_proc, &es);
 225         if (es.err) {
 226                 retval = es.err;
 227                 goto errout;
 228         }
 229
 230         if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
 231                 goto errout;
 232
 233         inode.i_size += fs->blocksize * size;
 234         inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
 235         inode.i_mtime = inode.i_ctime = time(0);
 236         inode.i_links_count = 1;
 237         inode.i_mode = LINUX_S_IFREG | 0600;
 238
 239         if ((retval = ext2fs_write_inode(fs, journal_ino, &inode)))
 240                 goto errout;
 241         retval = 0;
 242
 243 errout:
 244         ext2fs_free_mem((void **) &buf);
 245         return retval;
 246 }
 247
 248 /*
 249  * This function adds a journal device to a filesystem
 250  */
 251 errcode_t ext2fs_add_journal_device(ext2_filsys fs, ext2_filsys journal_dev)
 252 {
 253         struct stat     st;
 254         errcode_t       retval;
 255         char            buf[1024];
 256         journal_superblock_t    *jsb;
 257         int             i;
 258         __u32           nr_users;
 259
 260         /* Make sure the device exists and is a block device */
 261         if (stat(journal_dev->device_name, &st) < 0)
 262                 return errno;
 263
 264         if (!S_ISBLK(st.st_mode))
 265                 return EXT2_ET_JOURNAL_NOT_BLOCK; /* Must be a block device */
 266
 267         /* Get the journal superblock */
 268         if ((retval = io_channel_read_blk(journal_dev->io, 1, -1024, buf)))
 269                 return retval;
 270
 271         jsb = (journal_superblock_t *) buf;
 272         if ((jsb->s_header.h_magic != (unsigned) ntohl(JFS_MAGIC_NUMBER)) ||
 273             (jsb->s_header.h_blocktype != (unsigned) ntohl(JFS_SUPERBLOCK_V2)))
 274                 return EXT2_ET_NO_JOURNAL_SB;
 275
 276         if (ntohl(jsb->s_blocksize) != fs->blocksize)
 277                 return EXT2_ET_UNEXPECTED_BLOCK_SIZE;
 278
 279         /* Check and see if this filesystem has already been added */
 280         nr_users = ntohl(jsb->s_nr_users);
 281         for (i=0; i < nr_users; i++) {
 282                 if (memcmp(fs->super->s_uuid,
 283                            &jsb->s_users[i*16], 16) == 0)
 284                         break;
 285         }
 286         if (i >= nr_users) {
 287                 memcpy(&jsb->s_users[nr_users*16],
 288                        fs->super->s_uuid, 16);
 289                 jsb->s_nr_users = htonl(nr_users+1);
 290         }
 291
 292         /* Writeback the journal superblock */
 293         if ((retval = io_channel_write_blk(journal_dev->io, 1, -1024, buf)))
 294                 return retval;
 295
 296         fs->super->s_journal_inum = 0;
 297         fs->super->s_journal_dev = st.st_rdev;
 298         memcpy(fs->super->s_journal_uuid, jsb->s_uuid,
 299                sizeof(fs->super->s_journal_uuid));
 300         fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 301         ext2fs_mark_super_dirty(fs);
 302         return 0;
 303 }
 304
 305 /*
 306  * This function adds a journal inode to a filesystem, using either
 307  * POSIX routines if the filesystem is mounted, or using direct I/O
 308  * functions if it is not.
 309  */
 310 errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t size, int flags)
 311 {
 312         errcode_t               retval;
 313         ext2_ino_t              journal_ino;
 314         struct stat             st;
 315         char                    jfile[1024];
 316         int                     fd, mount_flags;
 317
 318         if ((retval = ext2fs_check_mount_point(fs->device_name, &mount_flags,
 319                                                jfile, sizeof(jfile)-10)))
 320                 return retval;
 321
 322         if (mount_flags & EXT2_MF_MOUNTED) {
 323                 strcat(jfile, "/.journal");
 324
 325                 /* Create the journal file */
 326                 if ((fd = open(jfile, O_CREAT|O_WRONLY, 0600)) < 0)
 327                         return errno;
 328                 close(fd);
 329
 330                 if ((retval = write_journal_file(fs, jfile, size, flags)))
 331                         return retval;
 332
 333                 /* Get inode number of the journal file */
 334                 if (stat(jfile, &st) < 0)
 335                         return errno;
 336
 337                 if ((retval = fsetflags(jfile,
 338                                         EXT2_NODUMP_FL | EXT2_IMMUTABLE_FL)))
 339                         return retval;
 340
 341                 journal_ino = st.st_ino;
 342         } else {
 343                 journal_ino = EXT2_JOURNAL_INO;
 344                 if ((retval = write_journal_inode(fs, journal_ino,
 345                                                   size, flags)))
 346                         return retval;
 347         }
 348
 349         fs->super->s_journal_inum = journal_ino;
 350         fs->super->s_journal_dev = 0;
 351         memset(fs->super->s_journal_uuid, 0,
 352                sizeof(fs->super->s_journal_uuid));
 353         fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 354
 355         ext2fs_mark_super_dirty(fs);
 356         return 0;
 357 }
 358
 359 #ifdef DEBUG
 360 main(int argc, char **argv)
 361 {
 362         errcode_t       retval;
 363         char            *device_name;
 364         ext2_filsys     fs;
 365
 366         if (argc < 2) {
 367                 fprintf(stderr, "Usage: %s filesystem\n", argv[0]);
 368                 exit(1);
 369         }
 370         device_name = argv[1];
 371
 372         retval = ext2fs_open (device_name, EXT2_FLAG_RW, 0, 0,
 373                               unix_io_manager, &fs);
 374         if (retval) {
 375                 com_err(argv[0], retval, "while opening %s", device_name);
 376                 exit(1);
 377         }
 378
 379         retval = ext2fs_add_journal_inode(fs, 1024);
 380         if (retval) {
 381                 com_err(argv[0], retval, "while adding journal to %s",
 382                         device_name);
 383                 exit(1);
 384         }
 385         retval = ext2fs_flush(fs);
 386         if (retval) {
 387                 printf("Warning, had trouble writing out superblocks.\n");
 388         }
 389         ext2fs_close(fs);
 390         exit(0);
 391
 392 }
 393 #endif