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 "ext2fs.h"
  39 #include "jfs_dat.h"
  40
  41 static void init_journal_superblock(journal_superblock_t *jsb,
  42                                     __u32 blocksize, __u32 size)
  43 {
  44         jsb->s_header.h_magic = htonl(JFS_MAGIC_NUMBER);
  45         jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK);
  46         jsb->s_header.h_sequence = 0;
  47         jsb->s_blocksize = htonl(blocksize);
  48         jsb->s_maxlen = htonl(size);
  49         jsb->s_first = htonl(1);
  50         jsb->s_sequence = htonl(1);
  51         jsb->s_start = 0;
  52 }
  53
  54 /*
  55  * This function adds a journal device to a filesystem
  56  */
  57 errcode_t ext2fs_add_journal_device(ext2_filsys fs, char *device,
  58                                     blk_t size)
  59 {
  60         journal_superblock_t    jsb;
  61         struct stat     st;
  62         errcode_t       retval;
  63         char            *buf = 0;
  64         blk_t           dev_size;
  65         int             i, fd, ret_size;
  66
  67         /* Make sure the device exists and is a block device */
  68         if (stat(device, &st) < 0)
  69                 return errno;
  70         if (!S_ISBLK(st.st_mode))
  71                 return EXT2_JOURNAL_NOT_BLOCK;  /* Must be a block device */
  72
  73         /* Get the size of the device */
  74         if ((retval = ext2fs_get_device_size(device, fs->blocksize,
  75                                              &dev_size)))
  76                 return retval;
  77
  78         if (!size)
  79                 size = dev_size; /* Default to the size of the device */
  80         else if (size > dev_size)
  81                 return EINVAL;  /* Requested size bigger than device */
  82
  83         init_journal_superblock(&jsb, fs->blocksize, size);
  84
  85         /* Create a block buffer */
  86         buf = malloc(fs->blocksize);
  87         if (!buf)
  88                 return ENOMEM;
  89
  90         /* Open the device */
  91         if ((fd = open(device, O_WRONLY)) < 0) {
  92                 retval = errno;
  93                 goto errout;
  94         }
  95
  96         /* Write the superblock out */
  97         memset(buf, 0, fs->blocksize);
  98         memcpy(buf, &jsb, sizeof(jsb));
  99         retval = EXT2_ET_SHORT_WRITE;
 100         ret_size = write(fd, buf, fs->blocksize);
 101         if (ret_size < 0) {
 102                 errno = retval;
 103                 goto errout;
 104         }
 105         if (ret_size != fs->blocksize)
 106                 goto errout;
 107         memset(buf, 0, fs->blocksize);
 108
 109         for (i=1; i < size; i++) {
 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         }
 118         close(fd);
 119
 120         fs->super->s_journal_dev = st.st_rdev;
 121         fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 122         ext2fs_mark_super_dirty(fs);
 123
 124         return 0;
 125 errout:
 126         if (buf)
 127                 free(buf);
 128         return retval;
 129 }
 130
 131 /*
 132  * Helper function for creating the journal in the filesystem
 133  */
 134 struct mkjournal_struct {
 135         int             num_blocks;
 136         int             newblocks;
 137         char            *buf;
 138         errcode_t       err;
 139 };
 140
 141 static int mkjournal_proc(ext2_filsys           fs,
 142                            blk_t                *blocknr,
 143                            e2_blkcnt_t          blockcnt,
 144                            blk_t                ref_block,
 145                            int                  ref_offset,
 146                            void                 *priv_data)
 147 {
 148         struct mkjournal_struct *es = (struct mkjournal_struct *) priv_data;
 149         blk_t   new_blk;
 150         static blk_t    last_blk = 0;
 151         char            *block;
 152         errcode_t       retval;
 153         int             group;
 154
 155         if (*blocknr) {
 156                 last_blk = *blocknr;
 157                 return 0;
 158         }
 159         retval = ext2fs_new_block(fs, last_blk, 0, &new_blk);
 160         if (retval) {
 161                 es->err = retval;
 162                 return BLOCK_ABORT;
 163         }
 164         if (blockcnt > 0)
 165                 es->num_blocks--;
 166
 167         es->newblocks++;
 168         retval = io_channel_write_blk(fs->io, new_blk, 1, es->buf);
 169
 170         if (blockcnt == 0)
 171                 memset(es->buf, 0, fs->blocksize);
 172
 173         if (retval) {
 174                 es->err = retval;
 175                 return BLOCK_ABORT;
 176         }
 177         *blocknr = new_blk;
 178         ext2fs_mark_block_bitmap(fs->block_map, new_blk);
 179         ext2fs_mark_bb_dirty(fs);
 180         group = ext2fs_group_of_blk(fs, new_blk);
 181         fs->group_desc[group].bg_free_blocks_count--;
 182         fs->super->s_free_blocks_count--;
 183         ext2fs_mark_super_dirty(fs);
 184
 185         if (es->num_blocks == 0)
 186                 return (BLOCK_CHANGED | BLOCK_ABORT);
 187         else
 188                 return BLOCK_CHANGED;
 189
 190 }
 191
 192 /*
 193  * This function adds a journal inode to a filesystem
 194  */
 195 errcode_t ext2fs_add_journal_fs(ext2_filsys fs, blk_t size)
 196 {
 197         journal_superblock_t    jsb;
 198         errcode_t               retval;
 199         struct ext2_inode       inode;
 200         struct mkjournal_struct es;
 201         char                    *buf;
 202
 203         init_journal_superblock(&jsb, fs->blocksize, size);
 204
 205         if ((retval = ext2fs_read_bitmaps(fs)))
 206                 return retval;
 207
 208         if ((retval = ext2fs_read_inode(fs, EXT2_JOURNAL_INO, &inode)))
 209                 return retval;
 210
 211         if (inode.i_blocks > 0)
 212                 return EEXIST;
 213
 214         /* Create the block buffer */
 215         buf = malloc(fs->blocksize);
 216         if (!buf)
 217                 return ENOMEM;
 218
 219         memset(buf, 0, fs->blocksize);
 220         memcpy(buf, &jsb, sizeof(jsb));
 221
 222         es.num_blocks = size;
 223         es.newblocks = 0;
 224         es.buf = buf;
 225         es.err = 0;
 226
 227         retval = ext2fs_block_iterate2(fs, EXT2_JOURNAL_INO, BLOCK_FLAG_APPEND,
 228                                        0, mkjournal_proc, &es);
 229         free(buf);
 230         if (es.err)
 231                 return es.err;
 232
 233         if ((retval = ext2fs_read_inode(fs, EXT2_JOURNAL_INO, &inode)))
 234                 return retval;
 235
 236         inode.i_size += fs->blocksize * size;
 237         inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
 238         inode.i_mtime = inode.i_ctime = time(0);
 239         inode.i_links_count = 1;
 240         inode.i_mode = LINUX_S_IFREG | 0600;
 241
 242         if ((retval = ext2fs_write_inode(fs, EXT2_JOURNAL_INO, &inode)))
 243                 return retval;
 244
 245         fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 246         fs->super->s_journal_inum = EXT2_JOURNAL_INO;
 247
 248         ext2fs_mark_super_dirty(fs);
 249         return 0;
 250 }
 251
 252 #ifdef DEBUG
 253 main(int argc, char **argv)
 254 {
 255         errcode_t       retval;
 256         char            *device_name;
 257         ext2_filsys     fs;
 258
 259         if (argc < 2) {
 260                 fprintf(stderr, "Usage: %s filesystem\n", argv[0]);
 261                 exit(1);
 262         }
 263         device_name = argv[1];
 264
 265         retval = ext2fs_open (device_name, EXT2_FLAG_RW, 0, 0,
 266                               unix_io_manager, &fs);
 267         if (retval) {
 268                 com_err(argv[0], retval, "while opening %s", device_name);
 269                 exit(1);
 270         }
 271
 272         retval = ext2fs_add_journal_fs(fs, 1024);
 273         if (retval) {
 274                 com_err(argv[0], retval, "while adding journal to %s",
 275                         device_name);
 276                 exit(1);
 277         }
 278         retval = ext2fs_flush(fs);
 279         if (retval) {
 280                 printf("Warning, had trouble writing out superblocks.\n");
 281         }
 282         ext2fs_close(fs);
 283         exit(0);
 284
 285 }
 286 #endif