1 /*
2 * linux/fs/ext2/super.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/inode.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Big-endian to little-endian byte-swapping/bitmaps by
16 * David S. Miller (davem@caip.rutgers.edu), 1995
17 */
18
19 #include <linux/config.h>
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/ext2_fs.h>
24 #include <linux/slab.h>
25 #include <linux/init.h>
26 #include <linux/locks.h>
27 #include <asm/uaccess.h>
28
29
30
31 static char error_buf[1024];
32
33 void ext2_error (struct super_block * sb, const char * function,
34 const char * fmt, ...)
35 {
36 va_list args;
37
38 if (!(sb->s_flags & MS_RDONLY)) {
39 sb->u.ext2_sb.s_mount_state |= EXT2_ERROR_FS;
40 sb->u.ext2_sb.s_es->s_state =
41 cpu_to_le16(le16_to_cpu(sb->u.ext2_sb.s_es->s_state) | EXT2_ERROR_FS);
42 mark_buffer_dirty(sb->u.ext2_sb.s_sbh);
43 sb->s_dirt = 1;
44 }
45 va_start (args, fmt);
46 vsprintf (error_buf, fmt, args);
47 va_end (args);
48 if (test_opt (sb, ERRORS_PANIC) ||
49 (le16_to_cpu(sb->u.ext2_sb.s_es->s_errors) == EXT2_ERRORS_PANIC &&
50 !test_opt (sb, ERRORS_CONT) && !test_opt (sb, ERRORS_RO)))
51 panic ("EXT2-fs panic (device %s): %s: %s\n",
52 bdevname(sb->s_dev), function, error_buf);
53 printk (KERN_CRIT "EXT2-fs error (device %s): %s: %s\n",
54 bdevname(sb->s_dev), function, error_buf);
55 if (test_opt (sb, ERRORS_RO) ||
56 (le16_to_cpu(sb->u.ext2_sb.s_es->s_errors) == EXT2_ERRORS_RO &&
57 !test_opt (sb, ERRORS_CONT) && !test_opt (sb, ERRORS_PANIC))) {
58 printk ("Remounting filesystem read-only\n");
59 sb->s_flags |= MS_RDONLY;
60 }
61 }
62
63 NORET_TYPE void ext2_panic (struct super_block * sb, const char * function,
64 const char * fmt, ...)
65 {
66 va_list args;
67
68 if (!(sb->s_flags & MS_RDONLY)) {
69 sb->u.ext2_sb.s_mount_state |= EXT2_ERROR_FS;
70 sb->u.ext2_sb.s_es->s_state =
71 cpu_to_le16(le16_to_cpu(sb->u.ext2_sb.s_es->s_state) | EXT2_ERROR_FS);
72 mark_buffer_dirty(sb->u.ext2_sb.s_sbh);
73 sb->s_dirt = 1;
74 }
75 va_start (args, fmt);
76 vsprintf (error_buf, fmt, args);
77 va_end (args);
78 /* this is to prevent panic from syncing this filesystem */
79 if (sb->s_lock)
80 sb->s_lock=0;
81 sb->s_flags |= MS_RDONLY;
82 panic ("EXT2-fs panic (device %s): %s: %s\n",
83 bdevname(sb->s_dev), function, error_buf);
84 }
85
86 void ext2_warning (struct super_block * sb, const char * function,
87 const char * fmt, ...)
88 {
89 va_list args;
90
91 va_start (args, fmt);
92 vsprintf (error_buf, fmt, args);
93 va_end (args);
94 printk (KERN_WARNING "EXT2-fs warning (device %s): %s: %s\n",
95 bdevname(sb->s_dev), function, error_buf);
96 }
97
98 void ext2_update_dynamic_rev(struct super_block *sb)
99 {
100 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
101
102 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
103 return;
104
105 ext2_warning(sb, __FUNCTION__,
106 "updating to rev %d because of new feature flag, "
107 "running e2fsck is recommended",
108 EXT2_DYNAMIC_REV);
109
110 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
111 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
112 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
113 /* leave es->s_feature_*compat flags alone */
114 /* es->s_uuid will be set by e2fsck if empty */
115
116 /*
117 * The rest of the superblock fields should be zero, and if not it
118 * means they are likely already in use, so leave them alone. We
119 * can leave it up to e2fsck to clean up any inconsistencies there.
120 */
121 }
122
123 void ext2_put_super (struct super_block * sb)
124 {
125 int db_count;
126 int i;
127
128 if (!(sb->s_flags & MS_RDONLY)) {
129 sb->u.ext2_sb.s_es->s_state = le16_to_cpu(sb->u.ext2_sb.s_mount_state);
130 mark_buffer_dirty(sb->u.ext2_sb.s_sbh);
131 }
132 db_count = EXT2_SB(sb)->s_gdb_count;
133 for (i = 0; i < db_count; i++)
134 if (sb->u.ext2_sb.s_group_desc[i])
135 brelse (sb->u.ext2_sb.s_group_desc[i]);
136 kfree(sb->u.ext2_sb.s_group_desc);
137 for (i = 0; i < EXT2_MAX_GROUP_LOADED; i++)
138 if (sb->u.ext2_sb.s_inode_bitmap[i])
139 brelse (sb->u.ext2_sb.s_inode_bitmap[i]);
140 for (i = 0; i < EXT2_MAX_GROUP_LOADED; i++)
141 if (sb->u.ext2_sb.s_block_bitmap[i])
142 brelse (sb->u.ext2_sb.s_block_bitmap[i]);
143 brelse (sb->u.ext2_sb.s_sbh);
144
145 return;
146 }
147
148 static struct super_operations ext2_sops = {
149 read_inode: ext2_read_inode,
150 write_inode: ext2_write_inode,
151 put_inode: ext2_put_inode,
152 delete_inode: ext2_delete_inode,
153 put_super: ext2_put_super,
154 write_super: ext2_write_super,
155 statfs: ext2_statfs,
156 remount_fs: ext2_remount,
157 };
158
159 /*
160 * This function has been shamelessly adapted from the msdos fs
161 */
162 static int parse_options (char * options, unsigned long * sb_block,
163 unsigned short *resuid, unsigned short * resgid,
164 unsigned long * mount_options)
165 {
166 char * this_char;
167 char * value;
168
169 if (!options)
170 return 1;
171 for (this_char = strtok (options, ",");
172 this_char != NULL;
173 this_char = strtok (NULL, ",")) {
174 if ((value = strchr (this_char, '=')) != NULL)
175 *value++ = 0;
176 if (!strcmp (this_char, "bsddf"))
177 clear_opt (*mount_options, MINIX_DF);
178 else if (!strcmp (this_char, "nouid32")) {
179 set_opt (*mount_options, NO_UID32);
180 }
181 else if (!strcmp (this_char, "check")) {
182 if (!value || !*value || !strcmp (value, "none"))
183 clear_opt (*mount_options, CHECK);
184 else
185 #ifdef CONFIG_EXT2_CHECK
186 set_opt (*mount_options, CHECK);
187 #else
188 printk("EXT2 Check option not supported\n");
189 #endif
190 }
191 else if (!strcmp (this_char, "debug"))
192 set_opt (*mount_options, DEBUG);
193 else if (!strcmp (this_char, "errors")) {
194 if (!value || !*value) {
195 printk ("EXT2-fs: the errors option requires "
196 "an argument\n");
197 return 0;
198 }
199 if (!strcmp (value, "continue")) {
200 clear_opt (*mount_options, ERRORS_RO);
201 clear_opt (*mount_options, ERRORS_PANIC);
202 set_opt (*mount_options, ERRORS_CONT);
203 }
204 else if (!strcmp (value, "remount-ro")) {
205 clear_opt (*mount_options, ERRORS_CONT);
206 clear_opt (*mount_options, ERRORS_PANIC);
207 set_opt (*mount_options, ERRORS_RO);
208 }
209 else if (!strcmp (value, "panic")) {
210 clear_opt (*mount_options, ERRORS_CONT);
211 clear_opt (*mount_options, ERRORS_RO);
212 set_opt (*mount_options, ERRORS_PANIC);
213 }
214 else {
215 printk ("EXT2-fs: Invalid errors option: %s\n",
216 value);
217 return 0;
218 }
219 }
220 else if (!strcmp (this_char, "grpid") ||
221 !strcmp (this_char, "bsdgroups"))
222 set_opt (*mount_options, GRPID);
223 else if (!strcmp (this_char, "minixdf"))
224 set_opt (*mount_options, MINIX_DF);
225 else if (!strcmp (this_char, "nocheck"))
226 clear_opt (*mount_options, CHECK);
227 else if (!strcmp (this_char, "nogrpid") ||
228 !strcmp (this_char, "sysvgroups"))
229 clear_opt (*mount_options, GRPID);
230 else if (!strcmp (this_char, "resgid")) {
231 if (!value || !*value) {
232 printk ("EXT2-fs: the resgid option requires "
233 "an argument\n");
234 return 0;
235 }
236 *resgid = simple_strtoul (value, &value, 0);
237 if (*value) {
238 printk ("EXT2-fs: Invalid resgid option: %s\n",
239 value);
240 return 0;
241 }
242 }
243 else if (!strcmp (this_char, "resuid")) {
244 if (!value || !*value) {
245 printk ("EXT2-fs: the resuid option requires "
246 "an argument");
247 return 0;
248 }
249 *resuid = simple_strtoul (value, &value, 0);
250 if (*value) {
251 printk ("EXT2-fs: Invalid resuid option: %s\n",
252 value);
253 return 0;
254 }
255 }
256 else if (!strcmp (this_char, "sb")) {
257 if (!value || !*value) {
258 printk ("EXT2-fs: the sb option requires "
259 "an argument");
260 return 0;
261 }
262 *sb_block = simple_strtoul (value, &value, 0);
263 if (*value) {
264 printk ("EXT2-fs: Invalid sb option: %s\n",
265 value);
266 return 0;
267 }
268 }
269 /* Silently ignore the quota options */
270 else if (!strcmp (this_char, "grpquota")
271 || !strcmp (this_char, "noquota")
272 || !strcmp (this_char, "quota")
273 || !strcmp (this_char, "usrquota"))
274 /* Don't do anything ;-) */ ;
275 else {
276 printk ("EXT2-fs: Unrecognized mount option %s\n", this_char);
277 return 0;
278 }
279 }
280 return 1;
281 }
282
283 static int ext2_setup_super (struct super_block * sb,
284 struct ext2_super_block * es,
285 int read_only)
286 {
287 int res = 0;
288 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
289 printk ("EXT2-fs warning: revision level too high, "
290 "forcing read-only mode\n");
291 res = MS_RDONLY;
292 }
293 if (read_only)
294 return res;
295 if (!(sb->u.ext2_sb.s_mount_state & EXT2_VALID_FS))
296 printk ("EXT2-fs warning: mounting unchecked fs, "
297 "running e2fsck is recommended\n");
298 else if ((sb->u.ext2_sb.s_mount_state & EXT2_ERROR_FS))
299 printk ("EXT2-fs warning: mounting fs with errors, "
300 "running e2fsck is recommended\n");
301 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
302 le16_to_cpu(es->s_mnt_count) >=
303 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
304 printk ("EXT2-fs warning: maximal mount count reached, "
305 "running e2fsck is recommended\n");
306 else if (le32_to_cpu(es->s_checkinterval) &&
307 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= CURRENT_TIME))
308 printk ("EXT2-fs warning: checktime reached, "
309 "running e2fsck is recommended\n");
310 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT2_VALID_FS);
311 if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
312 es->s_max_mnt_count = (__s16) cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
313 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
314 es->s_mtime = cpu_to_le32(CURRENT_TIME);
315 mark_buffer_dirty(sb->u.ext2_sb.s_sbh);
316 sb->s_dirt = 1;
317 if (test_opt (sb, DEBUG))
318 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
319 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
320 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
321 sb->u.ext2_sb.s_frag_size,
322 sb->u.ext2_sb.s_groups_count,
323 EXT2_BLOCKS_PER_GROUP(sb),
324 EXT2_INODES_PER_GROUP(sb),
325 sb->u.ext2_sb.s_mount_opt);
326 #ifdef CONFIG_EXT2_CHECK
327 if (test_opt (sb, CHECK)) {
328 ext2_check_blocks_bitmap (sb);
329 ext2_check_inodes_bitmap (sb);
330 }
331 #endif
332 return res;
333 }
334
335 static int ext2_check_descriptors (struct super_block * sb)
336 {
337 int i;
338 int desc_block = 0;
339 unsigned long block = le32_to_cpu(sb->u.ext2_sb.s_es->s_first_data_block);
340 struct ext2_group_desc * gdp = NULL;
341
342 ext2_debug ("Checking group descriptors");
343
344 for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++)
345 {
346 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
347 gdp = (struct ext2_group_desc *) sb->u.ext2_sb.s_group_desc[desc_block++]->b_data;
348 if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
349 le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
350 {
351 ext2_error (sb, "ext2_check_descriptors",
352 "Block bitmap for group %d"
353 " not in group (block %lu)!",
354 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
355 return 0;
356 }
357 if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
358 le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
359 {
360 ext2_error (sb, "ext2_check_descriptors",
361 "Inode bitmap for group %d"
362 " not in group (block %lu)!",
363 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
364 return 0;
365 }
366 if (le32_to_cpu(gdp->bg_inode_table) < block ||
367 le32_to_cpu(gdp->bg_inode_table) + sb->u.ext2_sb.s_itb_per_group >=
368 block + EXT2_BLOCKS_PER_GROUP(sb))
369 {
370 ext2_error (sb, "ext2_check_descriptors",
371 "Inode table for group %d"
372 " not in group (block %lu)!",
373 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
374 return 0;
375 }
376 block += EXT2_BLOCKS_PER_GROUP(sb);
377 gdp++;
378 }
379 return 1;
380 }
381
382 #define log2(n) ffz(~(n))
383
384 struct super_block * ext2_read_super (struct super_block * sb, void * data,
385 int silent)
386 {
387 struct buffer_head * bh;
388 struct ext2_super_block * es;
389 unsigned long sb_block = 1;
390 unsigned short resuid = EXT2_DEF_RESUID;
391 unsigned short resgid = EXT2_DEF_RESGID;
392 unsigned long logic_sb_block = 1;
393 unsigned long offset = 0;
394 kdev_t dev = sb->s_dev;
395 int blocksize = BLOCK_SIZE;
396 int hblock;
397 int db_count;
398 int i, j;
399
400 /*
401 * See what the current blocksize for the device is, and
402 * use that as the blocksize. Otherwise (or if the blocksize
403 * is smaller than the default) use the default.
404 * This is important for devices that have a hardware
405 * sectorsize that is larger than the default.
406 */
407 blocksize = get_hardblocksize(dev);
408 if( blocksize == 0 || blocksize < BLOCK_SIZE )
409 {
410 blocksize = BLOCK_SIZE;
411 }
412
413 sb->u.ext2_sb.s_mount_opt = 0;
414 if (!parse_options ((char *) data, &sb_block, &resuid, &resgid,
415 &sb->u.ext2_sb.s_mount_opt)) {
416 return NULL;
417 }
418
419 set_blocksize (dev, blocksize);
420
421 /*
422 * If the superblock doesn't start on a sector boundary,
423 * calculate the offset. FIXME(eric) this doesn't make sense
424 * that we would have to do this.
425 */
426 if (blocksize != BLOCK_SIZE) {
427 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
428 offset = (sb_block*BLOCK_SIZE) % blocksize;
429 }
430
431 if (!(bh = bread (dev, logic_sb_block, blocksize))) {
432 printk ("EXT2-fs: unable to read superblock\n");
433 return NULL;
434 }
435 /*
436 * Note: s_es must be initialized s_es as soon as possible because
437 * some ext2 macro-instructions depend on its value
438 */
439 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
440 sb->u.ext2_sb.s_es = es;
441 sb->s_magic = le16_to_cpu(es->s_magic);
442 if (sb->s_magic != EXT2_SUPER_MAGIC) {
443 if (!silent)
444 printk ("VFS: Can't find an ext2 filesystem on dev "
445 "%s.\n", bdevname(dev));
446 failed_mount:
447 if (bh)
448 brelse(bh);
449 return NULL;
450 }
451 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
452 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
453 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
454 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
455 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
456 "running e2fsck is recommended\n");
457 /*
458 * Check feature flags regardless of the revision level, since we
459 * previously didn't change the revision level when setting the flags,
460 * so there is a chance incompat flags are set on a rev 0 filesystem.
461 */
462 if ((i = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))) {
463 printk("EXT2-fs: %s: couldn't mount because of "
464 "unsupported optional features (%x).\n",
465 bdevname(dev), i);
466 goto failed_mount;
467 }
468 if (!(sb->s_flags & MS_RDONLY) &&
469 (i = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
470 printk("EXT2-fs: %s: couldn't mount RDWR because of "
471 "unsupported optional features (%x).\n",
472 bdevname(dev), i);
473 goto failed_mount;
474 }
475 sb->s_blocksize_bits =
476 le32_to_cpu(EXT2_SB(sb)->s_es->s_log_block_size) + 10;
477 sb->s_blocksize = 1 << sb->s_blocksize_bits;
478 if (sb->s_blocksize != BLOCK_SIZE &&
479 (sb->s_blocksize == 1024 || sb->s_blocksize == 2048 ||
480 sb->s_blocksize == 4096)) {
481 /*
482 * Make sure the blocksize for the filesystem is larger
483 * than the hardware sectorsize for the machine.
484 */
485 hblock = get_hardblocksize(dev);
486 if( (hblock != 0)
487 && (sb->s_blocksize < hblock) )
488 {
489 printk("EXT2-fs: blocksize too small for device.\n");
490 goto failed_mount;
491 }
492
493 brelse (bh);
494 set_blocksize (dev, sb->s_blocksize);
495 logic_sb_block = (sb_block*BLOCK_SIZE) / sb->s_blocksize;
496 offset = (sb_block*BLOCK_SIZE) % sb->s_blocksize;
497 bh = bread (dev, logic_sb_block, sb->s_blocksize);
498 if(!bh) {
499 printk("EXT2-fs: Couldn't read superblock on "
500 "2nd try.\n");
501 goto failed_mount;
502 }
503 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
504 sb->u.ext2_sb.s_es = es;
505 if (es->s_magic != le16_to_cpu(EXT2_SUPER_MAGIC)) {
506 printk ("EXT2-fs: Magic mismatch, very weird !\n");
507 goto failed_mount;
508 }
509 }
510 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
511 sb->u.ext2_sb.s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
512 sb->u.ext2_sb.s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
513 } else {
514 sb->u.ext2_sb.s_inode_size = le16_to_cpu(es->s_inode_size);
515 sb->u.ext2_sb.s_first_ino = le32_to_cpu(es->s_first_ino);
516 if (sb->u.ext2_sb.s_inode_size != EXT2_GOOD_OLD_INODE_SIZE) {
517 printk ("EXT2-fs: unsupported inode size: %d\n",
518 sb->u.ext2_sb.s_inode_size);
519 goto failed_mount;
520 }
521 }
522 sb->u.ext2_sb.s_frag_size = EXT2_MIN_FRAG_SIZE <<
523 le32_to_cpu(es->s_log_frag_size);
524 if (sb->u.ext2_sb.s_frag_size)
525 sb->u.ext2_sb.s_frags_per_block = sb->s_blocksize /
526 sb->u.ext2_sb.s_frag_size;
527 else
528 sb->s_magic = 0;
529 sb->u.ext2_sb.s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
530 sb->u.ext2_sb.s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
531 sb->u.ext2_sb.s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
532 sb->u.ext2_sb.s_inodes_per_block = sb->s_blocksize /
533 EXT2_INODE_SIZE(sb);
534 sb->u.ext2_sb.s_itb_per_group = sb->u.ext2_sb.s_inodes_per_group /
535 sb->u.ext2_sb.s_inodes_per_block;
536 sb->u.ext2_sb.s_desc_per_block = sb->s_blocksize /
537 sizeof (struct ext2_group_desc);
538 sb->u.ext2_sb.s_sbh = bh;
539 if (resuid != EXT2_DEF_RESUID)
540 sb->u.ext2_sb.s_resuid = resuid;
541 else
542 sb->u.ext2_sb.s_resuid = le16_to_cpu(es->s_def_resuid);
543 if (resgid != EXT2_DEF_RESGID)
544 sb->u.ext2_sb.s_resgid = resgid;
545 else
546 sb->u.ext2_sb.s_resgid = le16_to_cpu(es->s_def_resgid);
547 sb->u.ext2_sb.s_mount_state = le16_to_cpu(es->s_state);
548 sb->u.ext2_sb.s_addr_per_block_bits =
549 log2 (EXT2_ADDR_PER_BLOCK(sb));
550 sb->u.ext2_sb.s_desc_per_block_bits =
551 log2 (EXT2_DESC_PER_BLOCK(sb));
552 if (sb->s_magic != EXT2_SUPER_MAGIC) {
553 if (!silent)
554 printk ("VFS: Can't find an ext2 filesystem on dev "
555 "%s.\n",
556 bdevname(dev));
557 goto failed_mount;
558 }
559 if (sb->s_blocksize != bh->b_size) {
560 if (!silent)
561 printk ("VFS: Unsupported blocksize on dev "
562 "%s.\n", bdevname(dev));
563 goto failed_mount;
564 }
565
566 if (sb->s_blocksize != sb->u.ext2_sb.s_frag_size) {
567 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
568 sb->u.ext2_sb.s_frag_size, sb->s_blocksize);
569 goto failed_mount;
570 }
571
572 if (sb->u.ext2_sb.s_blocks_per_group > sb->s_blocksize * 8) {
573 printk ("EXT2-fs: #blocks per group too big: %lu\n",
574 sb->u.ext2_sb.s_blocks_per_group);
575 goto failed_mount;
576 }
577 if (sb->u.ext2_sb.s_frags_per_group > sb->s_blocksize * 8) {
578 printk ("EXT2-fs: #fragments per group too big: %lu\n",
579 sb->u.ext2_sb.s_frags_per_group);
580 goto failed_mount;
581 }
582 if (sb->u.ext2_sb.s_inodes_per_group > sb->s_blocksize * 8) {
583 printk ("EXT2-fs: #inodes per group too big: %lu\n",
584 sb->u.ext2_sb.s_inodes_per_group);
585 goto failed_mount;
586 }
587
588 sb->u.ext2_sb.s_groups_count = (le32_to_cpu(es->s_blocks_count) -
589 le32_to_cpu(es->s_first_data_block) +
590 EXT2_BLOCKS_PER_GROUP(sb) - 1) /
591 EXT2_BLOCKS_PER_GROUP(sb);
592 db_count = (sb->u.ext2_sb.s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
593 EXT2_DESC_PER_BLOCK(sb);
594 sb->u.ext2_sb.s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
595 if (sb->u.ext2_sb.s_group_desc == NULL) {
596 printk ("EXT2-fs: not enough memory\n");
597 goto failed_mount;
598 }
599 for (i = 0; i < db_count; i++) {
600 sb->u.ext2_sb.s_group_desc[i] = bread (dev, logic_sb_block + i + 1,
601 sb->s_blocksize);
602 if (!sb->u.ext2_sb.s_group_desc[i]) {
603 for (j = 0; j < i; j++)
604 brelse (sb->u.ext2_sb.s_group_desc[j]);
605 kfree(sb->u.ext2_sb.s_group_desc);
606 printk ("EXT2-fs: unable to read group descriptors\n");
607 goto failed_mount;
608 }
609 }
610 if (!ext2_check_descriptors (sb)) {
611 for (j = 0; j < db_count; j++)
612 brelse (sb->u.ext2_sb.s_group_desc[j]);
613 kfree(sb->u.ext2_sb.s_group_desc);
614 printk ("EXT2-fs: group descriptors corrupted !\n");
615 goto failed_mount;
616 }
617 for (i = 0; i < EXT2_MAX_GROUP_LOADED; i++) {
618 sb->u.ext2_sb.s_inode_bitmap_number[i] = 0;
619 sb->u.ext2_sb.s_inode_bitmap[i] = NULL;
620 sb->u.ext2_sb.s_block_bitmap_number[i] = 0;
621 sb->u.ext2_sb.s_block_bitmap[i] = NULL;
622 }
623 sb->u.ext2_sb.s_loaded_inode_bitmaps = 0;
624 sb->u.ext2_sb.s_loaded_block_bitmaps = 0;
625 sb->u.ext2_sb.s_gdb_count = db_count;
626 /*
627 * set up enough so that it can read an inode
628 */
629 sb->s_op = &ext2_sops;
630 sb->s_root = d_alloc_root(iget(sb, EXT2_ROOT_INO));
631 if (!sb->s_root) {
632 for (i = 0; i < db_count; i++)
633 if (sb->u.ext2_sb.s_group_desc[i])
634 brelse (sb->u.ext2_sb.s_group_desc[i]);
635 kfree(sb->u.ext2_sb.s_group_desc);
636 brelse (bh);
637 printk ("EXT2-fs: get root inode failed\n");
638 return NULL;
639 }
640 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
641 return sb;
642 }
643
644 static void ext2_commit_super (struct super_block * sb,
645 struct ext2_super_block * es)
646 {
647 es->s_wtime = cpu_to_le32(CURRENT_TIME);
648 mark_buffer_dirty(sb->u.ext2_sb.s_sbh);
649 sb->s_dirt = 0;
650 }
651
652 /*
653 * In the second extended file system, it is not necessary to
654 * write the super block since we use a mapping of the
655 * disk super block in a buffer.
656 *
657 * However, this function is still used to set the fs valid
658 * flags to 0. We need to set this flag to 0 since the fs
659 * may have been checked while mounted and e2fsck may have
660 * set s_state to EXT2_VALID_FS after some corrections.
661 */
662
663 void ext2_write_super (struct super_block * sb)
664 {
665 struct ext2_super_block * es;
666
667 if (!(sb->s_flags & MS_RDONLY)) {
668 es = sb->u.ext2_sb.s_es;
669
670 ext2_debug ("setting valid to 0\n");
671
672 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
673 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT2_VALID_FS);
674 es->s_mtime = cpu_to_le32(CURRENT_TIME);
675 }
676 ext2_commit_super (sb, es);
677 }
678 sb->s_dirt = 0;
679 }
680
681 int ext2_remount (struct super_block * sb, int * flags, char * data)
682 {
683 struct ext2_super_block * es;
684 unsigned short resuid = sb->u.ext2_sb.s_resuid;
685 unsigned short resgid = sb->u.ext2_sb.s_resgid;
686 unsigned long new_mount_opt;
687 unsigned long tmp;
688
689 /*
690 * Allow the "check" option to be passed as a remount option.
691 */
692 new_mount_opt = sb->u.ext2_sb.s_mount_opt;
693 if (!parse_options (data, &tmp, &resuid, &resgid,
694 &new_mount_opt))
695 return -EINVAL;
696
697 sb->u.ext2_sb.s_mount_opt = new_mount_opt;
698 sb->u.ext2_sb.s_resuid = resuid;
699 sb->u.ext2_sb.s_resgid = resgid;
700 es = sb->u.ext2_sb.s_es;
701 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
702 return 0;
703 if (*flags & MS_RDONLY) {
704 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
705 !(sb->u.ext2_sb.s_mount_state & EXT2_VALID_FS))
706 return 0;
707 /*
708 * OK, we are remounting a valid rw partition rdonly, so set
709 * the rdonly flag and then mark the partition as valid again.
710 */
711 es->s_state = cpu_to_le16(sb->u.ext2_sb.s_mount_state);
712 es->s_mtime = cpu_to_le32(CURRENT_TIME);
713 mark_buffer_dirty(sb->u.ext2_sb.s_sbh);
714 sb->s_dirt = 1;
715 ext2_commit_super (sb, es);
716 }
717 else {
718 int ret;
719 if ((ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
720 ~EXT2_FEATURE_RO_COMPAT_SUPP))) {
721 printk("EXT2-fs: %s: couldn't remount RDWR because of "
722 "unsupported optional features (%x).\n",
723 bdevname(sb->s_dev), ret);
724 return -EROFS;
725 }
726 /*
727 * Mounting a RDONLY partition read-write, so reread and
728 * store the current valid flag. (It may have been changed
729 * by e2fsck since we originally mounted the partition.)
730 */
731 sb->u.ext2_sb.s_mount_state = le16_to_cpu(es->s_state);
732 if (!ext2_setup_super (sb, es, 0))
733 sb->s_flags &= ~MS_RDONLY;
734 }
735 return 0;
736 }
737
738 int ext2_statfs (struct super_block * sb, struct statfs * buf)
739 {
740 unsigned long overhead;
741 int i;
742
743 if (test_opt (sb, MINIX_DF))
744 overhead = 0;
745 else {
746 /*
747 * Compute the overhead (FS structures)
748 */
749
750 /*
751 * All of the blocks before first_data_block are
752 * overhead
753 */
754 overhead = le32_to_cpu(sb->u.ext2_sb.s_es->s_first_data_block);
755
756 /*
757 * Add the overhead attributed to the superblock and
758 * block group descriptors. If the sparse superblocks
759 * feature is turned on, then not all groups have this.
760 */
761 for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++)
762 overhead += ext2_bg_has_super(sb, i) +
763 ext2_bg_num_gdb(sb, i);
764
765 /*
766 * Every block group has an inode bitmap, a block
767 * bitmap, and an inode table.
768 */
769 overhead += (sb->u.ext2_sb.s_groups_count *
770 (2 + sb->u.ext2_sb.s_itb_per_group));
771 }
772
773 buf->f_type = EXT2_SUPER_MAGIC;
774 buf->f_bsize = sb->s_blocksize;
775 buf->f_blocks = le32_to_cpu(sb->u.ext2_sb.s_es->s_blocks_count) - overhead;
776 buf->f_bfree = ext2_count_free_blocks (sb);
777 buf->f_bavail = buf->f_bfree - le32_to_cpu(sb->u.ext2_sb.s_es->s_r_blocks_count);
778 if (buf->f_bfree < le32_to_cpu(sb->u.ext2_sb.s_es->s_r_blocks_count))
779 buf->f_bavail = 0;
780 buf->f_files = le32_to_cpu(sb->u.ext2_sb.s_es->s_inodes_count);
781 buf->f_ffree = ext2_count_free_inodes (sb);
782 buf->f_namelen = EXT2_NAME_LEN;
783 return 0;
784 }
785
786 static DECLARE_FSTYPE_DEV(ext2_fs_type, "ext2", ext2_read_super);
787
788 static int __init init_ext2_fs(void)
789 {
790 return register_filesystem(&ext2_fs_type);
791 }
792
793 static void __exit exit_ext2_fs(void)
794 {
795 unregister_filesystem(&ext2_fs_type);
796 }
797
798 EXPORT_NO_SYMBOLS;
799
800 module_init(init_ext2_fs)
801 module_exit(exit_ext2_fs)
802
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