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 */
ext2fs_create_journal_superblock(ext2_filsys fs,__u32 size,int flags,char ** ret_jsb)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, &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 */
write_journal_file(ext2_filsys fs,char * filename,blk_t size,int flags)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 fd, ret_size;
98 blk_t i;
99
100 if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf)))
101 return retval;
102
103 /* Open the device or journal file */
104 if ((fd = open(filename, O_WRONLY)) < 0) {
105 retval = errno;
106 goto errout;
107 }
108
109 /* Write the superblock out */
110 retval = EXT2_ET_SHORT_WRITE;
111 ret_size = write(fd, buf, fs->blocksize);
112 if (ret_size < 0) {
113 retval = errno;
114 goto errout;
115 }
116 if (ret_size != (int) fs->blocksize)
117 goto errout;
118 memset(buf, 0, fs->blocksize);
119
120 for (i = 1; i < size; i++) {
121 ret_size = write(fd, buf, fs->blocksize);
122 if (ret_size < 0) {
123 retval = errno;
124 goto errout;
125 }
126 if (ret_size != (int) fs->blocksize)
127 goto errout;
128 }
129 close(fd);
130
131 retval = 0;
132 errout:
133 ext2fs_free_mem(&buf);
134 return retval;
135 }
136
137 /*
138 * Helper function for creating the journal using direct I/O routines
139 */
140 struct mkjournal_struct {
141 int num_blocks;
142 int newblocks;
143 char *buf;
144 errcode_t err;
145 };
146
mkjournal_proc(ext2_filsys fs,blk_t * blocknr,e2_blkcnt_t blockcnt,blk_t ref_block EXT2FS_ATTR ((unused)),int ref_offset EXT2FS_ATTR ((unused)),void * priv_data)147 static int mkjournal_proc(ext2_filsys fs,
148 blk_t *blocknr,
149 e2_blkcnt_t blockcnt,
150 blk_t ref_block EXT2FS_ATTR((unused)),
151 int ref_offset EXT2FS_ATTR((unused)),
152 void *priv_data)
153 {
154 struct mkjournal_struct *es = (struct mkjournal_struct *) priv_data;
155 blk_t new_blk;
156 static blk_t last_blk = 0;
157 errcode_t retval;
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_block_alloc_stats(fs, new_blk, +1);
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 creates a journal using direct I/O routines.
194 */
write_journal_inode(ext2_filsys fs,ext2_ino_t journal_ino,blk_t size,int flags)195 static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino,
196 blk_t size, int flags)
197 {
198 char *buf;
199 errcode_t retval;
200 struct ext2_inode inode;
201 struct mkjournal_struct es;
202
203 if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf)))
204 return retval;
205
206 if ((retval = ext2fs_read_bitmaps(fs)))
207 return retval;
208
209 if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
210 return retval;
211
212 if (inode.i_blocks > 0)
213 return EEXIST;
214
215 es.num_blocks = size;
216 es.newblocks = 0;
217 es.buf = buf;
218 es.err = 0;
219
220 retval = ext2fs_block_iterate2(fs, journal_ino, BLOCK_FLAG_APPEND,
221 0, mkjournal_proc, &es);
222 if (es.err) {
223 retval = es.err;
224 goto errout;
225 }
226
227 if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
228 goto errout;
229
230 inode.i_size += fs->blocksize * size;
231 inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
232 inode.i_mtime = inode.i_ctime = fs->now ? fs->now : time(0);
233 inode.i_links_count = 1;
234 inode.i_mode = LINUX_S_IFREG | 0600;
235
236 if ((retval = ext2fs_write_inode(fs, journal_ino, &inode)))
237 goto errout;
238 retval = 0;
239
240 memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
241 fs->super->s_jnl_blocks[16] = inode.i_size;
242 fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
243 ext2fs_mark_super_dirty(fs);
244
245 errout:
246 ext2fs_free_mem(&buf);
247 return retval;
248 }
249
250 /*
251 * Find a reasonable journal file size (in blocks) given the number of blocks
252 * in the filesystem. For very small filesystems, it is not reasonable to
253 * have a journal that fills more than half of the filesystem.
254 */
ext2fs_default_journal_size(__u64 blocks)255 int ext2fs_default_journal_size(__u64 blocks)
256 {
257 if (blocks < 2048)
258 return -1;
259 if (blocks < 32768)
260 return (1024);
261 if (blocks < 256*1024)
262 return (4096);
263 if (blocks < 512*1024)
264 return (8192);
265 if (blocks < 1024*1024)
266 return (16384);
267 return 32768;
268 }
269
270 /*
271 * This function adds a journal device to a filesystem
272 */
ext2fs_add_journal_device(ext2_filsys fs,ext2_filsys journal_dev)273 errcode_t ext2fs_add_journal_device(ext2_filsys fs, ext2_filsys journal_dev)
274 {
275 struct stat st;
276 errcode_t retval;
277 char buf[1024];
278 journal_superblock_t *jsb;
279 int start;
280 __u32 i, nr_users;
281
282 /* Make sure the device exists and is a block device */
283 if (stat(journal_dev->device_name, &st) < 0)
284 return errno;
285
286 if (!S_ISBLK(st.st_mode))
287 return EXT2_ET_JOURNAL_NOT_BLOCK; /* Must be a block device */
288
289 /* Get the journal superblock */
290 start = 1;
291 if (journal_dev->blocksize == 1024)
292 start++;
293 if ((retval = io_channel_read_blk(journal_dev->io, start, -1024, buf)))
294 return retval;
295
296 jsb = (journal_superblock_t *) buf;
297 if ((jsb->s_header.h_magic != (unsigned) ntohl(JFS_MAGIC_NUMBER)) ||
298 (jsb->s_header.h_blocktype != (unsigned) ntohl(JFS_SUPERBLOCK_V2)))
299 return EXT2_ET_NO_JOURNAL_SB;
300
301 if (ntohl(jsb->s_blocksize) != (unsigned long) fs->blocksize)
302 return EXT2_ET_UNEXPECTED_BLOCK_SIZE;
303
304 /* Check and see if this filesystem has already been added */
305 nr_users = ntohl(jsb->s_nr_users);
306 for (i=0; i < nr_users; i++) {
307 if (memcmp(fs->super->s_uuid,
308 &jsb->s_users[i*16], 16) == 0)
309 break;
310 }
311 if (i >= nr_users) {
312 memcpy(&jsb->s_users[nr_users*16],
313 fs->super->s_uuid, 16);
314 jsb->s_nr_users = htonl(nr_users+1);
315 }
316
317 /* Writeback the journal superblock */
318 if ((retval = io_channel_write_blk(journal_dev->io, start, -1024, buf)))
319 return retval;
320
321 fs->super->s_journal_inum = 0;
322 fs->super->s_journal_dev = st.st_rdev;
323 memcpy(fs->super->s_journal_uuid, jsb->s_uuid,
324 sizeof(fs->super->s_journal_uuid));
325 fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
326 ext2fs_mark_super_dirty(fs);
327 return 0;
328 }
329
330 /*
331 * This function adds a journal inode to a filesystem, using either
332 * POSIX routines if the filesystem is mounted, or using direct I/O
333 * functions if it is not.
334 */
ext2fs_add_journal_inode(ext2_filsys fs,blk_t size,int flags)335 errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t size, int flags)
336 {
337 errcode_t retval;
338 ext2_ino_t journal_ino;
339 struct stat st;
340 char jfile[1024];
341 int mount_flags, f;
342 int fd = -1;
343
344 if ((retval = ext2fs_check_mount_point(fs->device_name, &mount_flags,
345 jfile, sizeof(jfile)-10)))
346 return retval;
347
348 if (mount_flags & EXT2_MF_MOUNTED) {
349 strcat(jfile, "/.journal");
350
351 /*
352 * If .../.journal already exists, make sure any
353 * immutable or append-only flags are cleared.
354 */
355 #if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
356 (void) chflags (jfile, 0);
357 #else
358 #if HAVE_EXT2_IOCTLS
359 fd = open(jfile, O_RDONLY);
360 if (fd >= 0) {
361 f = 0;
362 ioctl(fd, EXT2_IOC_SETFLAGS, &f);
363 close(fd);
364 }
365 #endif
366 #endif
367
368 /* Create the journal file */
369 if ((fd = open(jfile, O_CREAT|O_WRONLY, 0600)) < 0)
370 return errno;
371
372 if ((retval = write_journal_file(fs, jfile, size, flags)))
373 goto errout;
374
375 /* Get inode number of the journal file */
376 if (fstat(fd, &st) < 0)
377 goto errout;
378
379 #if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
380 retval = fchflags (fd, UF_NODUMP|UF_IMMUTABLE);
381 #else
382 #if HAVE_EXT2_IOCTLS
383 f = EXT2_NODUMP_FL | EXT2_IMMUTABLE_FL;
384 retval = ioctl(fd, EXT2_IOC_SETFLAGS, &f);
385 #endif
386 #endif
387 if (retval)
388 goto errout;
389
390 close(fd);
391 journal_ino = st.st_ino;
392 } else {
393 if ((mount_flags & EXT2_MF_BUSY) &&
394 !(fs->flags & EXT2_FLAG_EXCLUSIVE)) {
395 retval = EBUSY;
396 goto errout;
397 }
398 journal_ino = EXT2_JOURNAL_INO;
399 if ((retval = write_journal_inode(fs, journal_ino,
400 size, flags)))
401 return retval;
402 }
403
404 fs->super->s_journal_inum = journal_ino;
405 fs->super->s_journal_dev = 0;
406 memset(fs->super->s_journal_uuid, 0,
407 sizeof(fs->super->s_journal_uuid));
408 fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
409
410 ext2fs_mark_super_dirty(fs);
411 return 0;
412 errout:
413 if (fd > 0)
414 close(fd);
415 return retval;
416 }
417
418 #ifdef DEBUG
main(int argc,char ** argv)419 main(int argc, char **argv)
420 {
421 errcode_t retval;
422 char *device_name;
423 ext2_filsys fs;
424
425 if (argc < 2) {
426 fprintf(stderr, "Usage: %s filesystem\n", argv[0]);
427 exit(1);
428 }
429 device_name = argv[1];
430
431 retval = ext2fs_open (device_name, EXT2_FLAG_RW, 0, 0,
432 unix_io_manager, &fs);
433 if (retval) {
434 com_err(argv[0], retval, "while opening %s", device_name);
435 exit(1);
436 }
437
438 retval = ext2fs_add_journal_inode(fs, 1024);
439 if (retval) {
440 com_err(argv[0], retval, "while adding journal to %s",
441 device_name);
442 exit(1);
443 }
444 retval = ext2fs_flush(fs);
445 if (retval) {
446 printf("Warning, had trouble writing out superblocks.\n");
447 }
448 ext2fs_close(fs);
449 exit(0);
450
451 }
452 #endif
453