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HID: hiddev: Fix slab-out-of-bounds write in hiddev_ioctl_usage()
[linux/fpc-iii.git] / fs / ext2 / super.c
blob0d44f7ef3c5d0428273edc7ec64065901b9fc880
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/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/slab.h>
23 #include <linux/init.h>
24 #include <linux/blkdev.h>
25 #include <linux/parser.h>
26 #include <linux/random.h>
27 #include <linux/buffer_head.h>
28 #include <linux/exportfs.h>
29 #include <linux/vfs.h>
30 #include <linux/seq_file.h>
31 #include <linux/mount.h>
32 #include <linux/log2.h>
33 #include <linux/quotaops.h>
34 #include <asm/uaccess.h>
35 #include "ext2.h"
36 #include "xattr.h"
37 #include "acl.h"
38
39 static void ext2_sync_super(struct super_block *sb,
40 struct ext2_super_block *es, int wait);
41 static int ext2_remount (struct super_block * sb, int * flags, char * data);
42 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
43 static int ext2_sync_fs(struct super_block *sb, int wait);
44 static int ext2_freeze(struct super_block *sb);
45 static int ext2_unfreeze(struct super_block *sb);
46
47 void ext2_error(struct super_block *sb, const char *function,
48 const char *fmt, ...)
49 {
50 struct va_format vaf;
51 va_list args;
52 struct ext2_sb_info *sbi = EXT2_SB(sb);
53 struct ext2_super_block *es = sbi->s_es;
54
55 if (!(sb->s_flags & MS_RDONLY)) {
56 spin_lock(&sbi->s_lock);
57 sbi->s_mount_state |= EXT2_ERROR_FS;
58 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
59 spin_unlock(&sbi->s_lock);
60 ext2_sync_super(sb, es, 1);
61 }
62
63 va_start(args, fmt);
64
65 vaf.fmt = fmt;
66 vaf.va = &args;
67
68 printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
69 sb->s_id, function, &vaf);
70
71 va_end(args);
72
73 if (test_opt(sb, ERRORS_PANIC))
74 panic("EXT2-fs: panic from previous error\n");
75 if (test_opt(sb, ERRORS_RO)) {
76 ext2_msg(sb, KERN_CRIT,
77 "error: remounting filesystem read-only");
78 sb->s_flags |= MS_RDONLY;
79 }
80 }
81
82 void ext2_msg(struct super_block *sb, const char *prefix,
83 const char *fmt, ...)
84 {
85 struct va_format vaf;
86 va_list args;
87
88 va_start(args, fmt);
89
90 vaf.fmt = fmt;
91 vaf.va = &args;
92
93 printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
94
95 va_end(args);
96 }
97
98 /*
99 * This must be called with sbi->s_lock held.
100 */
101 void ext2_update_dynamic_rev(struct super_block *sb)
102 {
103 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
104
105 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
106 return;
107
108 ext2_msg(sb, KERN_WARNING,
109 "warning: updating to rev %d because of "
110 "new feature flag, running e2fsck is recommended",
111 EXT2_DYNAMIC_REV);
112
113 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
114 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
115 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
116 /* leave es->s_feature_*compat flags alone */
117 /* es->s_uuid will be set by e2fsck if empty */
118
119 /*
120 * The rest of the superblock fields should be zero, and if not it
121 * means they are likely already in use, so leave them alone. We
122 * can leave it up to e2fsck to clean up any inconsistencies there.
123 */
124 }
125
126 static void ext2_put_super (struct super_block * sb)
127 {
128 int db_count;
129 int i;
130 struct ext2_sb_info *sbi = EXT2_SB(sb);
131
132 dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
133
134 ext2_xattr_put_super(sb);
135 if (!(sb->s_flags & MS_RDONLY)) {
136 struct ext2_super_block *es = sbi->s_es;
137
138 spin_lock(&sbi->s_lock);
139 es->s_state = cpu_to_le16(sbi->s_mount_state);
140 spin_unlock(&sbi->s_lock);
141 ext2_sync_super(sb, es, 1);
142 }
143 db_count = sbi->s_gdb_count;
144 for (i = 0; i < db_count; i++)
145 if (sbi->s_group_desc[i])
146 brelse (sbi->s_group_desc[i]);
147 kfree(sbi->s_group_desc);
148 kfree(sbi->s_debts);
149 percpu_counter_destroy(&sbi->s_freeblocks_counter);
150 percpu_counter_destroy(&sbi->s_freeinodes_counter);
151 percpu_counter_destroy(&sbi->s_dirs_counter);
152 brelse (sbi->s_sbh);
153 sb->s_fs_info = NULL;
154 kfree(sbi->s_blockgroup_lock);
155 kfree(sbi);
156 }
157
158 static struct kmem_cache * ext2_inode_cachep;
159
160 static struct inode *ext2_alloc_inode(struct super_block *sb)
161 {
162 struct ext2_inode_info *ei;
163 ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
164 if (!ei)
165 return NULL;
166 ei->i_block_alloc_info = NULL;
167 ei->vfs_inode.i_version = 1;
168 #ifdef CONFIG_QUOTA
169 memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
170 #endif
171
172 return &ei->vfs_inode;
173 }
174
175 static void ext2_i_callback(struct rcu_head *head)
176 {
177 struct inode *inode = container_of(head, struct inode, i_rcu);
178 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
179 }
180
181 static void ext2_destroy_inode(struct inode *inode)
182 {
183 call_rcu(&inode->i_rcu, ext2_i_callback);
184 }
185
186 static void init_once(void *foo)
187 {
188 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
189
190 rwlock_init(&ei->i_meta_lock);
191 #ifdef CONFIG_EXT2_FS_XATTR
192 init_rwsem(&ei->xattr_sem);
193 #endif
194 mutex_init(&ei->truncate_mutex);
195 #ifdef CONFIG_FS_DAX
196 init_rwsem(&ei->dax_sem);
197 #endif
198 inode_init_once(&ei->vfs_inode);
199 }
200
201 static int __init init_inodecache(void)
202 {
203 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
204 sizeof(struct ext2_inode_info),
205 0, (SLAB_RECLAIM_ACCOUNT|
206 SLAB_MEM_SPREAD),
207 init_once);
208 if (ext2_inode_cachep == NULL)
209 return -ENOMEM;
210 return 0;
211 }
212
213 static void destroy_inodecache(void)
214 {
215 /*
216 * Make sure all delayed rcu free inodes are flushed before we
217 * destroy cache.
218 */
219 rcu_barrier();
220 kmem_cache_destroy(ext2_inode_cachep);
221 }
222
223 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
224 {
225 struct super_block *sb = root->d_sb;
226 struct ext2_sb_info *sbi = EXT2_SB(sb);
227 struct ext2_super_block *es = sbi->s_es;
228 unsigned long def_mount_opts;
229
230 spin_lock(&sbi->s_lock);
231 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
232
233 if (sbi->s_sb_block != 1)
234 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
235 if (test_opt(sb, MINIX_DF))
236 seq_puts(seq, ",minixdf");
237 if (test_opt(sb, GRPID))
238 seq_puts(seq, ",grpid");
239 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
240 seq_puts(seq, ",nogrpid");
241 if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
242 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
243 seq_printf(seq, ",resuid=%u",
244 from_kuid_munged(&init_user_ns, sbi->s_resuid));
245 }
246 if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
247 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
248 seq_printf(seq, ",resgid=%u",
249 from_kgid_munged(&init_user_ns, sbi->s_resgid));
250 }
251 if (test_opt(sb, ERRORS_RO)) {
252 int def_errors = le16_to_cpu(es->s_errors);
253
254 if (def_errors == EXT2_ERRORS_PANIC ||
255 def_errors == EXT2_ERRORS_CONTINUE) {
256 seq_puts(seq, ",errors=remount-ro");
257 }
258 }
259 if (test_opt(sb, ERRORS_CONT))
260 seq_puts(seq, ",errors=continue");
261 if (test_opt(sb, ERRORS_PANIC))
262 seq_puts(seq, ",errors=panic");
263 if (test_opt(sb, NO_UID32))
264 seq_puts(seq, ",nouid32");
265 if (test_opt(sb, DEBUG))
266 seq_puts(seq, ",debug");
267 if (test_opt(sb, OLDALLOC))
268 seq_puts(seq, ",oldalloc");
269
270 #ifdef CONFIG_EXT2_FS_XATTR
271 if (test_opt(sb, XATTR_USER))
272 seq_puts(seq, ",user_xattr");
273 if (!test_opt(sb, XATTR_USER) &&
274 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
275 seq_puts(seq, ",nouser_xattr");
276 }
277 #endif
278
279 #ifdef CONFIG_EXT2_FS_POSIX_ACL
280 if (test_opt(sb, POSIX_ACL))
281 seq_puts(seq, ",acl");
282 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
283 seq_puts(seq, ",noacl");
284 #endif
285
286 if (test_opt(sb, NOBH))
287 seq_puts(seq, ",nobh");
288
289 #if defined(CONFIG_QUOTA)
290 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
291 seq_puts(seq, ",usrquota");
292
293 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
294 seq_puts(seq, ",grpquota");
295 #endif
296
297 #ifdef CONFIG_FS_DAX
298 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
299 seq_puts(seq, ",xip");
300 if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
301 seq_puts(seq, ",dax");
302 #endif
303
304 if (!test_opt(sb, RESERVATION))
305 seq_puts(seq, ",noreservation");
306
307 spin_unlock(&sbi->s_lock);
308 return 0;
309 }
310
311 #ifdef CONFIG_QUOTA
312 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
313 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
314 static struct dquot **ext2_get_dquots(struct inode *inode)
315 {
316 return EXT2_I(inode)->i_dquot;
317 }
318 #endif
319
320 static const struct super_operations ext2_sops = {
321 .alloc_inode = ext2_alloc_inode,
322 .destroy_inode = ext2_destroy_inode,
323 .write_inode = ext2_write_inode,
324 .evict_inode = ext2_evict_inode,
325 .put_super = ext2_put_super,
326 .sync_fs = ext2_sync_fs,
327 .freeze_fs = ext2_freeze,
328 .unfreeze_fs = ext2_unfreeze,
329 .statfs = ext2_statfs,
330 .remount_fs = ext2_remount,
331 .show_options = ext2_show_options,
332 #ifdef CONFIG_QUOTA
333 .quota_read = ext2_quota_read,
334 .quota_write = ext2_quota_write,
335 .get_dquots = ext2_get_dquots,
336 #endif
337 };
338
339 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
340 u64 ino, u32 generation)
341 {
342 struct inode *inode;
343
344 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
345 return ERR_PTR(-ESTALE);
346 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
347 return ERR_PTR(-ESTALE);
348
349 /*
350 * ext2_iget isn't quite right if the inode is currently unallocated!
351 * However ext2_iget currently does appropriate checks to handle stale
352 * inodes so everything is OK.
353 */
354 inode = ext2_iget(sb, ino);
355 if (IS_ERR(inode))
356 return ERR_CAST(inode);
357 if (generation && inode->i_generation != generation) {
358 /* we didn't find the right inode.. */
359 iput(inode);
360 return ERR_PTR(-ESTALE);
361 }
362 return inode;
363 }
364
365 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
366 int fh_len, int fh_type)
367 {
368 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
369 ext2_nfs_get_inode);
370 }
371
372 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
373 int fh_len, int fh_type)
374 {
375 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
376 ext2_nfs_get_inode);
377 }
378
379 static const struct export_operations ext2_export_ops = {
380 .fh_to_dentry = ext2_fh_to_dentry,
381 .fh_to_parent = ext2_fh_to_parent,
382 .get_parent = ext2_get_parent,
383 };
384
385 static unsigned long get_sb_block(void **data)
386 {
387 unsigned long sb_block;
388 char *options = (char *) *data;
389
390 if (!options || strncmp(options, "sb=", 3) != 0)
391 return 1; /* Default location */
392 options += 3;
393 sb_block = simple_strtoul(options, &options, 0);
394 if (*options && *options != ',') {
395 printk("EXT2-fs: Invalid sb specification: %s\n",
396 (char *) *data);
397 return 1;
398 }
399 if (*options == ',')
400 options++;
401 *data = (void *) options;
402 return sb_block;
403 }
404
405 enum {
406 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
407 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
408 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
409 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
410 Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
411 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
412 };
413
414 static const match_table_t tokens = {
415 {Opt_bsd_df, "bsddf"},
416 {Opt_minix_df, "minixdf"},
417 {Opt_grpid, "grpid"},
418 {Opt_grpid, "bsdgroups"},
419 {Opt_nogrpid, "nogrpid"},
420 {Opt_nogrpid, "sysvgroups"},
421 {Opt_resgid, "resgid=%u"},
422 {Opt_resuid, "resuid=%u"},
423 {Opt_sb, "sb=%u"},
424 {Opt_err_cont, "errors=continue"},
425 {Opt_err_panic, "errors=panic"},
426 {Opt_err_ro, "errors=remount-ro"},
427 {Opt_nouid32, "nouid32"},
428 {Opt_nocheck, "check=none"},
429 {Opt_nocheck, "nocheck"},
430 {Opt_debug, "debug"},
431 {Opt_oldalloc, "oldalloc"},
432 {Opt_orlov, "orlov"},
433 {Opt_nobh, "nobh"},
434 {Opt_user_xattr, "user_xattr"},
435 {Opt_nouser_xattr, "nouser_xattr"},
436 {Opt_acl, "acl"},
437 {Opt_noacl, "noacl"},
438 {Opt_xip, "xip"},
439 {Opt_dax, "dax"},
440 {Opt_grpquota, "grpquota"},
441 {Opt_ignore, "noquota"},
442 {Opt_quota, "quota"},
443 {Opt_usrquota, "usrquota"},
444 {Opt_reservation, "reservation"},
445 {Opt_noreservation, "noreservation"},
446 {Opt_err, NULL}
447 };
448
449 static int parse_options(char *options, struct super_block *sb)
450 {
451 char *p;
452 struct ext2_sb_info *sbi = EXT2_SB(sb);
453 substring_t args[MAX_OPT_ARGS];
454 int option;
455 kuid_t uid;
456 kgid_t gid;
457
458 if (!options)
459 return 1;
460
461 while ((p = strsep (&options, ",")) != NULL) {
462 int token;
463 if (!*p)
464 continue;
465
466 token = match_token(p, tokens, args);
467 switch (token) {
468 case Opt_bsd_df:
469 clear_opt (sbi->s_mount_opt, MINIX_DF);
470 break;
471 case Opt_minix_df:
472 set_opt (sbi->s_mount_opt, MINIX_DF);
473 break;
474 case Opt_grpid:
475 set_opt (sbi->s_mount_opt, GRPID);
476 break;
477 case Opt_nogrpid:
478 clear_opt (sbi->s_mount_opt, GRPID);
479 break;
480 case Opt_resuid:
481 if (match_int(&args[0], &option))
482 return 0;
483 uid = make_kuid(current_user_ns(), option);
484 if (!uid_valid(uid)) {
485 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
486 return 0;
487
488 }
489 sbi->s_resuid = uid;
490 break;
491 case Opt_resgid:
492 if (match_int(&args[0], &option))
493 return 0;
494 gid = make_kgid(current_user_ns(), option);
495 if (!gid_valid(gid)) {
496 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
497 return 0;
498 }
499 sbi->s_resgid = gid;
500 break;
501 case Opt_sb:
502 /* handled by get_sb_block() instead of here */
503 /* *sb_block = match_int(&args[0]); */
504 break;
505 case Opt_err_panic:
506 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
507 clear_opt (sbi->s_mount_opt, ERRORS_RO);
508 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
509 break;
510 case Opt_err_ro:
511 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
512 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
513 set_opt (sbi->s_mount_opt, ERRORS_RO);
514 break;
515 case Opt_err_cont:
516 clear_opt (sbi->s_mount_opt, ERRORS_RO);
517 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
518 set_opt (sbi->s_mount_opt, ERRORS_CONT);
519 break;
520 case Opt_nouid32:
521 set_opt (sbi->s_mount_opt, NO_UID32);
522 break;
523 case Opt_nocheck:
524 clear_opt (sbi->s_mount_opt, CHECK);
525 break;
526 case Opt_debug:
527 set_opt (sbi->s_mount_opt, DEBUG);
528 break;
529 case Opt_oldalloc:
530 set_opt (sbi->s_mount_opt, OLDALLOC);
531 break;
532 case Opt_orlov:
533 clear_opt (sbi->s_mount_opt, OLDALLOC);
534 break;
535 case Opt_nobh:
536 set_opt (sbi->s_mount_opt, NOBH);
537 break;
538 #ifdef CONFIG_EXT2_FS_XATTR
539 case Opt_user_xattr:
540 set_opt (sbi->s_mount_opt, XATTR_USER);
541 break;
542 case Opt_nouser_xattr:
543 clear_opt (sbi->s_mount_opt, XATTR_USER);
544 break;
545 #else
546 case Opt_user_xattr:
547 case Opt_nouser_xattr:
548 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
549 "not supported");
550 break;
551 #endif
552 #ifdef CONFIG_EXT2_FS_POSIX_ACL
553 case Opt_acl:
554 set_opt(sbi->s_mount_opt, POSIX_ACL);
555 break;
556 case Opt_noacl:
557 clear_opt(sbi->s_mount_opt, POSIX_ACL);
558 break;
559 #else
560 case Opt_acl:
561 case Opt_noacl:
562 ext2_msg(sb, KERN_INFO,
563 "(no)acl options not supported");
564 break;
565 #endif
566 case Opt_xip:
567 ext2_msg(sb, KERN_INFO, "use dax instead of xip");
568 set_opt(sbi->s_mount_opt, XIP);
569 /* Fall through */
570 case Opt_dax:
571 #ifdef CONFIG_FS_DAX
572 ext2_msg(sb, KERN_WARNING,
573 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
574 set_opt(sbi->s_mount_opt, DAX);
575 #else
576 ext2_msg(sb, KERN_INFO, "dax option not supported");
577 #endif
578 break;
579
580 #if defined(CONFIG_QUOTA)
581 case Opt_quota:
582 case Opt_usrquota:
583 set_opt(sbi->s_mount_opt, USRQUOTA);
584 break;
585
586 case Opt_grpquota:
587 set_opt(sbi->s_mount_opt, GRPQUOTA);
588 break;
589 #else
590 case Opt_quota:
591 case Opt_usrquota:
592 case Opt_grpquota:
593 ext2_msg(sb, KERN_INFO,
594 "quota operations not supported");
595 break;
596 #endif
597
598 case Opt_reservation:
599 set_opt(sbi->s_mount_opt, RESERVATION);
600 ext2_msg(sb, KERN_INFO, "reservations ON");
601 break;
602 case Opt_noreservation:
603 clear_opt(sbi->s_mount_opt, RESERVATION);
604 ext2_msg(sb, KERN_INFO, "reservations OFF");
605 break;
606 case Opt_ignore:
607 break;
608 default:
609 return 0;
610 }
611 }
612 return 1;
613 }
614
615 static int ext2_setup_super (struct super_block * sb,
616 struct ext2_super_block * es,
617 int read_only)
618 {
619 int res = 0;
620 struct ext2_sb_info *sbi = EXT2_SB(sb);
621
622 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
623 ext2_msg(sb, KERN_ERR,
624 "error: revision level too high, "
625 "forcing read-only mode");
626 res = MS_RDONLY;
627 }
628 if (read_only)
629 return res;
630 if (!(sbi->s_mount_state & EXT2_VALID_FS))
631 ext2_msg(sb, KERN_WARNING,
632 "warning: mounting unchecked fs, "
633 "running e2fsck is recommended");
634 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
635 ext2_msg(sb, KERN_WARNING,
636 "warning: mounting fs with errors, "
637 "running e2fsck is recommended");
638 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
639 le16_to_cpu(es->s_mnt_count) >=
640 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
641 ext2_msg(sb, KERN_WARNING,
642 "warning: maximal mount count reached, "
643 "running e2fsck is recommended");
644 else if (le32_to_cpu(es->s_checkinterval) &&
645 (le32_to_cpu(es->s_lastcheck) +
646 le32_to_cpu(es->s_checkinterval) <= get_seconds()))
647 ext2_msg(sb, KERN_WARNING,
648 "warning: checktime reached, "
649 "running e2fsck is recommended");
650 if (!le16_to_cpu(es->s_max_mnt_count))
651 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
652 le16_add_cpu(&es->s_mnt_count, 1);
653 if (test_opt (sb, DEBUG))
654 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
655 "bpg=%lu, ipg=%lu, mo=%04lx]",
656 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
657 sbi->s_frag_size,
658 sbi->s_groups_count,
659 EXT2_BLOCKS_PER_GROUP(sb),
660 EXT2_INODES_PER_GROUP(sb),
661 sbi->s_mount_opt);
662 return res;
663 }
664
665 static int ext2_check_descriptors(struct super_block *sb)
666 {
667 int i;
668 struct ext2_sb_info *sbi = EXT2_SB(sb);
669
670 ext2_debug ("Checking group descriptors");
671
672 for (i = 0; i < sbi->s_groups_count; i++) {
673 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
674 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
675 ext2_fsblk_t last_block;
676
677 if (i == sbi->s_groups_count - 1)
678 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
679 else
680 last_block = first_block +
681 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
682
683 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
684 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
685 {
686 ext2_error (sb, "ext2_check_descriptors",
687 "Block bitmap for group %d"
688 " not in group (block %lu)!",
689 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
690 return 0;
691 }
692 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
693 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
694 {
695 ext2_error (sb, "ext2_check_descriptors",
696 "Inode bitmap for group %d"
697 " not in group (block %lu)!",
698 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
699 return 0;
700 }
701 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
702 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
703 last_block)
704 {
705 ext2_error (sb, "ext2_check_descriptors",
706 "Inode table for group %d"
707 " not in group (block %lu)!",
708 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
709 return 0;
710 }
711 }
712 return 1;
713 }
714
715 /*
716 * Maximal file size. There is a direct, and {,double-,triple-}indirect
717 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
718 * We need to be 1 filesystem block less than the 2^32 sector limit.
719 */
720 static loff_t ext2_max_size(int bits)
721 {
722 loff_t res = EXT2_NDIR_BLOCKS;
723 int meta_blocks;
724 unsigned int upper_limit;
725 unsigned int ppb = 1 << (bits-2);
726
727 /* This is calculated to be the largest file size for a
728 * dense, file such that the total number of
729 * sectors in the file, including data and all indirect blocks,
730 * does not exceed 2^32 -1
731 * __u32 i_blocks representing the total number of
732 * 512 bytes blocks of the file
733 */
734 upper_limit = (1LL << 32) - 1;
735
736 /* total blocks in file system block size */
737 upper_limit >>= (bits - 9);
738
739 /* Compute how many blocks we can address by block tree */
740 res += 1LL << (bits-2);
741 res += 1LL << (2*(bits-2));
742 res += 1LL << (3*(bits-2));
743 /* Does block tree limit file size? */
744 if (res < upper_limit)
745 goto check_lfs;
746
747 res = upper_limit;
748 /* How many metadata blocks are needed for addressing upper_limit? */
749 upper_limit -= EXT2_NDIR_BLOCKS;
750 /* indirect blocks */
751 meta_blocks = 1;
752 upper_limit -= ppb;
753 /* double indirect blocks */
754 if (upper_limit < ppb * ppb) {
755 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
756 res -= meta_blocks;
757 goto check_lfs;
758 }
759 meta_blocks += 1 + ppb;
760 upper_limit -= ppb * ppb;
761 /* tripple indirect blocks for the rest */
762 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
763 DIV_ROUND_UP(upper_limit, ppb*ppb);
764 res -= meta_blocks;
765 check_lfs:
766 res <<= bits;
767 if (res > MAX_LFS_FILESIZE)
768 res = MAX_LFS_FILESIZE;
769
770 return res;
771 }
772
773 static unsigned long descriptor_loc(struct super_block *sb,
774 unsigned long logic_sb_block,
775 int nr)
776 {
777 struct ext2_sb_info *sbi = EXT2_SB(sb);
778 unsigned long bg, first_meta_bg;
779 int has_super = 0;
780
781 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
782
783 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
784 nr < first_meta_bg)
785 return (logic_sb_block + nr + 1);
786 bg = sbi->s_desc_per_block * nr;
787 if (ext2_bg_has_super(sb, bg))
788 has_super = 1;
789
790 return ext2_group_first_block_no(sb, bg) + has_super;
791 }
792
793 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
794 {
795 struct buffer_head * bh;
796 struct ext2_sb_info * sbi;
797 struct ext2_super_block * es;
798 struct inode *root;
799 unsigned long block;
800 unsigned long sb_block = get_sb_block(&data);
801 unsigned long logic_sb_block;
802 unsigned long offset = 0;
803 unsigned long def_mount_opts;
804 long ret = -EINVAL;
805 int blocksize = BLOCK_SIZE;
806 int db_count;
807 int i, j;
808 __le32 features;
809 int err;
810
811 err = -ENOMEM;
812 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
813 if (!sbi)
814 goto failed;
815
816 sbi->s_blockgroup_lock =
817 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
818 if (!sbi->s_blockgroup_lock) {
819 kfree(sbi);
820 goto failed;
821 }
822 sb->s_fs_info = sbi;
823 sbi->s_sb_block = sb_block;
824
825 spin_lock_init(&sbi->s_lock);
826
827 /*
828 * See what the current blocksize for the device is, and
829 * use that as the blocksize. Otherwise (or if the blocksize
830 * is smaller than the default) use the default.
831 * This is important for devices that have a hardware
832 * sectorsize that is larger than the default.
833 */
834 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
835 if (!blocksize) {
836 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
837 goto failed_sbi;
838 }
839
840 /*
841 * If the superblock doesn't start on a hardware sector boundary,
842 * calculate the offset.
843 */
844 if (blocksize != BLOCK_SIZE) {
845 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
846 offset = (sb_block*BLOCK_SIZE) % blocksize;
847 } else {
848 logic_sb_block = sb_block;
849 }
850
851 if (!(bh = sb_bread(sb, logic_sb_block))) {
852 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
853 goto failed_sbi;
854 }
855 /*
856 * Note: s_es must be initialized as soon as possible because
857 * some ext2 macro-instructions depend on its value
858 */
859 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
860 sbi->s_es = es;
861 sb->s_magic = le16_to_cpu(es->s_magic);
862
863 if (sb->s_magic != EXT2_SUPER_MAGIC)
864 goto cantfind_ext2;
865
866 /* Set defaults before we parse the mount options */
867 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
868 if (def_mount_opts & EXT2_DEFM_DEBUG)
869 set_opt(sbi->s_mount_opt, DEBUG);
870 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
871 set_opt(sbi->s_mount_opt, GRPID);
872 if (def_mount_opts & EXT2_DEFM_UID16)
873 set_opt(sbi->s_mount_opt, NO_UID32);
874 #ifdef CONFIG_EXT2_FS_XATTR
875 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
876 set_opt(sbi->s_mount_opt, XATTR_USER);
877 #endif
878 #ifdef CONFIG_EXT2_FS_POSIX_ACL
879 if (def_mount_opts & EXT2_DEFM_ACL)
880 set_opt(sbi->s_mount_opt, POSIX_ACL);
881 #endif
882
883 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
884 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
885 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
886 set_opt(sbi->s_mount_opt, ERRORS_CONT);
887 else
888 set_opt(sbi->s_mount_opt, ERRORS_RO);
889
890 sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
891 sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
892
893 set_opt(sbi->s_mount_opt, RESERVATION);
894
895 if (!parse_options((char *) data, sb))
896 goto failed_mount;
897
898 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
899 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
900 MS_POSIXACL : 0);
901 sb->s_iflags |= SB_I_CGROUPWB;
902
903 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
904 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
905 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
906 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
907 ext2_msg(sb, KERN_WARNING,
908 "warning: feature flags set on rev 0 fs, "
909 "running e2fsck is recommended");
910 /*
911 * Check feature flags regardless of the revision level, since we
912 * previously didn't change the revision level when setting the flags,
913 * so there is a chance incompat flags are set on a rev 0 filesystem.
914 */
915 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
916 if (features) {
917 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
918 "unsupported optional features (%x)",
919 le32_to_cpu(features));
920 goto failed_mount;
921 }
922 if (!(sb->s_flags & MS_RDONLY) &&
923 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
924 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
925 "unsupported optional features (%x)",
926 le32_to_cpu(features));
927 goto failed_mount;
928 }
929
930 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
931
932 if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
933 if (blocksize != PAGE_SIZE) {
934 ext2_msg(sb, KERN_ERR,
935 "error: unsupported blocksize for dax");
936 goto failed_mount;
937 }
938 if (!sb->s_bdev->bd_disk->fops->direct_access) {
939 ext2_msg(sb, KERN_ERR,
940 "error: device does not support dax");
941 goto failed_mount;
942 }
943 }
944
945 /* If the blocksize doesn't match, re-read the thing.. */
946 if (sb->s_blocksize != blocksize) {
947 brelse(bh);
948
949 if (!sb_set_blocksize(sb, blocksize)) {
950 ext2_msg(sb, KERN_ERR,
951 "error: bad blocksize %d", blocksize);
952 goto failed_sbi;
953 }
954
955 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
956 offset = (sb_block*BLOCK_SIZE) % blocksize;
957 bh = sb_bread(sb, logic_sb_block);
958 if(!bh) {
959 ext2_msg(sb, KERN_ERR, "error: couldn't read"
960 "superblock on 2nd try");
961 goto failed_sbi;
962 }
963 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
964 sbi->s_es = es;
965 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
966 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
967 goto failed_mount;
968 }
969 }
970
971 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
972 sb->s_max_links = EXT2_LINK_MAX;
973
974 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
975 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
976 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
977 } else {
978 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
979 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
980 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
981 !is_power_of_2(sbi->s_inode_size) ||
982 (sbi->s_inode_size > blocksize)) {
983 ext2_msg(sb, KERN_ERR,
984 "error: unsupported inode size: %d",
985 sbi->s_inode_size);
986 goto failed_mount;
987 }
988 }
989
990 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
991 le32_to_cpu(es->s_log_frag_size);
992 if (sbi->s_frag_size == 0)
993 goto cantfind_ext2;
994 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
995
996 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
997 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
998 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
999
1000 if (EXT2_INODE_SIZE(sb) == 0)
1001 goto cantfind_ext2;
1002 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1003 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1004 goto cantfind_ext2;
1005 sbi->s_itb_per_group = sbi->s_inodes_per_group /
1006 sbi->s_inodes_per_block;
1007 sbi->s_desc_per_block = sb->s_blocksize /
1008 sizeof (struct ext2_group_desc);
1009 sbi->s_sbh = bh;
1010 sbi->s_mount_state = le16_to_cpu(es->s_state);
1011 sbi->s_addr_per_block_bits =
1012 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1013 sbi->s_desc_per_block_bits =
1014 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1015
1016 if (sb->s_magic != EXT2_SUPER_MAGIC)
1017 goto cantfind_ext2;
1018
1019 if (sb->s_blocksize != bh->b_size) {
1020 if (!silent)
1021 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1022 goto failed_mount;
1023 }
1024
1025 if (sb->s_blocksize != sbi->s_frag_size) {
1026 ext2_msg(sb, KERN_ERR,
1027 "error: fragsize %lu != blocksize %lu"
1028 "(not supported yet)",
1029 sbi->s_frag_size, sb->s_blocksize);
1030 goto failed_mount;
1031 }
1032
1033 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1034 ext2_msg(sb, KERN_ERR,
1035 "error: #blocks per group too big: %lu",
1036 sbi->s_blocks_per_group);
1037 goto failed_mount;
1038 }
1039 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1040 ext2_msg(sb, KERN_ERR,
1041 "error: #fragments per group too big: %lu",
1042 sbi->s_frags_per_group);
1043 goto failed_mount;
1044 }
1045 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1046 ext2_msg(sb, KERN_ERR,
1047 "error: #inodes per group too big: %lu",
1048 sbi->s_inodes_per_group);
1049 goto failed_mount;
1050 }
1051
1052 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1053 goto cantfind_ext2;
1054 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1055 le32_to_cpu(es->s_first_data_block) - 1)
1056 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1057 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1058 EXT2_DESC_PER_BLOCK(sb);
1059 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1060 if (sbi->s_group_desc == NULL) {
1061 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1062 goto failed_mount;
1063 }
1064 bgl_lock_init(sbi->s_blockgroup_lock);
1065 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1066 if (!sbi->s_debts) {
1067 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1068 goto failed_mount_group_desc;
1069 }
1070 for (i = 0; i < db_count; i++) {
1071 block = descriptor_loc(sb, logic_sb_block, i);
1072 sbi->s_group_desc[i] = sb_bread(sb, block);
1073 if (!sbi->s_group_desc[i]) {
1074 for (j = 0; j < i; j++)
1075 brelse (sbi->s_group_desc[j]);
1076 ext2_msg(sb, KERN_ERR,
1077 "error: unable to read group descriptors");
1078 goto failed_mount_group_desc;
1079 }
1080 }
1081 if (!ext2_check_descriptors (sb)) {
1082 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1083 goto failed_mount2;
1084 }
1085 sbi->s_gdb_count = db_count;
1086 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1087 spin_lock_init(&sbi->s_next_gen_lock);
1088
1089 /* per fileystem reservation list head & lock */
1090 spin_lock_init(&sbi->s_rsv_window_lock);
1091 sbi->s_rsv_window_root = RB_ROOT;
1092 /*
1093 * Add a single, static dummy reservation to the start of the
1094 * reservation window list --- it gives us a placeholder for
1095 * append-at-start-of-list which makes the allocation logic
1096 * _much_ simpler.
1097 */
1098 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1099 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1100 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1101 sbi->s_rsv_window_head.rsv_goal_size = 0;
1102 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1103
1104 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1105 ext2_count_free_blocks(sb), GFP_KERNEL);
1106 if (!err) {
1107 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1108 ext2_count_free_inodes(sb), GFP_KERNEL);
1109 }
1110 if (!err) {
1111 err = percpu_counter_init(&sbi->s_dirs_counter,
1112 ext2_count_dirs(sb), GFP_KERNEL);
1113 }
1114 if (err) {
1115 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1116 goto failed_mount3;
1117 }
1118 /*
1119 * set up enough so that it can read an inode
1120 */
1121 sb->s_op = &ext2_sops;
1122 sb->s_export_op = &ext2_export_ops;
1123 sb->s_xattr = ext2_xattr_handlers;
1124
1125 #ifdef CONFIG_QUOTA
1126 sb->dq_op = &dquot_operations;
1127 sb->s_qcop = &dquot_quotactl_ops;
1128 sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1129 #endif
1130
1131 root = ext2_iget(sb, EXT2_ROOT_INO);
1132 if (IS_ERR(root)) {
1133 ret = PTR_ERR(root);
1134 goto failed_mount3;
1135 }
1136 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1137 iput(root);
1138 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1139 goto failed_mount3;
1140 }
1141
1142 sb->s_root = d_make_root(root);
1143 if (!sb->s_root) {
1144 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1145 ret = -ENOMEM;
1146 goto failed_mount3;
1147 }
1148 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1149 ext2_msg(sb, KERN_WARNING,
1150 "warning: mounting ext3 filesystem as ext2");
1151 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1152 sb->s_flags |= MS_RDONLY;
1153 ext2_write_super(sb);
1154 return 0;
1155
1156 cantfind_ext2:
1157 if (!silent)
1158 ext2_msg(sb, KERN_ERR,
1159 "error: can't find an ext2 filesystem on dev %s.",
1160 sb->s_id);
1161 goto failed_mount;
1162 failed_mount3:
1163 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1164 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1165 percpu_counter_destroy(&sbi->s_dirs_counter);
1166 failed_mount2:
1167 for (i = 0; i < db_count; i++)
1168 brelse(sbi->s_group_desc[i]);
1169 failed_mount_group_desc:
1170 kfree(sbi->s_group_desc);
1171 kfree(sbi->s_debts);
1172 failed_mount:
1173 brelse(bh);
1174 failed_sbi:
1175 sb->s_fs_info = NULL;
1176 kfree(sbi->s_blockgroup_lock);
1177 kfree(sbi);
1178 failed:
1179 return ret;
1180 }
1181
1182 static void ext2_clear_super_error(struct super_block *sb)
1183 {
1184 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1185
1186 if (buffer_write_io_error(sbh)) {
1187 /*
1188 * Oh, dear. A previous attempt to write the
1189 * superblock failed. This could happen because the
1190 * USB device was yanked out. Or it could happen to
1191 * be a transient write error and maybe the block will
1192 * be remapped. Nothing we can do but to retry the
1193 * write and hope for the best.
1194 */
1195 ext2_msg(sb, KERN_ERR,
1196 "previous I/O error to superblock detected\n");
1197 clear_buffer_write_io_error(sbh);
1198 set_buffer_uptodate(sbh);
1199 }
1200 }
1201
1202 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1203 int wait)
1204 {
1205 ext2_clear_super_error(sb);
1206 spin_lock(&EXT2_SB(sb)->s_lock);
1207 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1208 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1209 es->s_wtime = cpu_to_le32(get_seconds());
1210 /* unlock before we do IO */
1211 spin_unlock(&EXT2_SB(sb)->s_lock);
1212 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1213 if (wait)
1214 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1215 }
1216
1217 /*
1218 * In the second extended file system, it is not necessary to
1219 * write the super block since we use a mapping of the
1220 * disk super block in a buffer.
1221 *
1222 * However, this function is still used to set the fs valid
1223 * flags to 0. We need to set this flag to 0 since the fs
1224 * may have been checked while mounted and e2fsck may have
1225 * set s_state to EXT2_VALID_FS after some corrections.
1226 */
1227 static int ext2_sync_fs(struct super_block *sb, int wait)
1228 {
1229 struct ext2_sb_info *sbi = EXT2_SB(sb);
1230 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1231
1232 /*
1233 * Write quota structures to quota file, sync_blockdev() will write
1234 * them to disk later
1235 */
1236 dquot_writeback_dquots(sb, -1);
1237
1238 spin_lock(&sbi->s_lock);
1239 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1240 ext2_debug("setting valid to 0\n");
1241 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1242 }
1243 spin_unlock(&sbi->s_lock);
1244 ext2_sync_super(sb, es, wait);
1245 return 0;
1246 }
1247
1248 static int ext2_freeze(struct super_block *sb)
1249 {
1250 struct ext2_sb_info *sbi = EXT2_SB(sb);
1251
1252 /*
1253 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1254 * because we have unattached inodes and thus filesystem is not fully
1255 * consistent.
1256 */
1257 if (atomic_long_read(&sb->s_remove_count)) {
1258 ext2_sync_fs(sb, 1);
1259 return 0;
1260 }
1261 /* Set EXT2_FS_VALID flag */
1262 spin_lock(&sbi->s_lock);
1263 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1264 spin_unlock(&sbi->s_lock);
1265 ext2_sync_super(sb, sbi->s_es, 1);
1266
1267 return 0;
1268 }
1269
1270 static int ext2_unfreeze(struct super_block *sb)
1271 {
1272 /* Just write sb to clear EXT2_VALID_FS flag */
1273 ext2_write_super(sb);
1274
1275 return 0;
1276 }
1277
1278 void ext2_write_super(struct super_block *sb)
1279 {
1280 if (!(sb->s_flags & MS_RDONLY))
1281 ext2_sync_fs(sb, 1);
1282 }
1283
1284 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1285 {
1286 struct ext2_sb_info * sbi = EXT2_SB(sb);
1287 struct ext2_super_block * es;
1288 struct ext2_mount_options old_opts;
1289 unsigned long old_sb_flags;
1290 int err;
1291
1292 sync_filesystem(sb);
1293 spin_lock(&sbi->s_lock);
1294
1295 /* Store the old options */
1296 old_sb_flags = sb->s_flags;
1297 old_opts.s_mount_opt = sbi->s_mount_opt;
1298 old_opts.s_resuid = sbi->s_resuid;
1299 old_opts.s_resgid = sbi->s_resgid;
1300
1301 /*
1302 * Allow the "check" option to be passed as a remount option.
1303 */
1304 if (!parse_options(data, sb)) {
1305 err = -EINVAL;
1306 goto restore_opts;
1307 }
1308
1309 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1310 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1311
1312 es = sbi->s_es;
1313 if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1314 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1315 "dax flag with busy inodes while remounting");
1316 sbi->s_mount_opt ^= EXT2_MOUNT_DAX;
1317 }
1318 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1319 spin_unlock(&sbi->s_lock);
1320 return 0;
1321 }
1322 if (*flags & MS_RDONLY) {
1323 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1324 !(sbi->s_mount_state & EXT2_VALID_FS)) {
1325 spin_unlock(&sbi->s_lock);
1326 return 0;
1327 }
1328
1329 /*
1330 * OK, we are remounting a valid rw partition rdonly, so set
1331 * the rdonly flag and then mark the partition as valid again.
1332 */
1333 es->s_state = cpu_to_le16(sbi->s_mount_state);
1334 es->s_mtime = cpu_to_le32(get_seconds());
1335 spin_unlock(&sbi->s_lock);
1336
1337 err = dquot_suspend(sb, -1);
1338 if (err < 0) {
1339 spin_lock(&sbi->s_lock);
1340 goto restore_opts;
1341 }
1342
1343 ext2_sync_super(sb, es, 1);
1344 } else {
1345 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1346 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1347 if (ret) {
1348 ext2_msg(sb, KERN_WARNING,
1349 "warning: couldn't remount RDWR because of "
1350 "unsupported optional features (%x).",
1351 le32_to_cpu(ret));
1352 err = -EROFS;
1353 goto restore_opts;
1354 }
1355 /*
1356 * Mounting a RDONLY partition read-write, so reread and
1357 * store the current valid flag. (It may have been changed
1358 * by e2fsck since we originally mounted the partition.)
1359 */
1360 sbi->s_mount_state = le16_to_cpu(es->s_state);
1361 if (!ext2_setup_super (sb, es, 0))
1362 sb->s_flags &= ~MS_RDONLY;
1363 spin_unlock(&sbi->s_lock);
1364
1365 ext2_write_super(sb);
1366
1367 dquot_resume(sb, -1);
1368 }
1369
1370 return 0;
1371 restore_opts:
1372 sbi->s_mount_opt = old_opts.s_mount_opt;
1373 sbi->s_resuid = old_opts.s_resuid;
1374 sbi->s_resgid = old_opts.s_resgid;
1375 sb->s_flags = old_sb_flags;
1376 spin_unlock(&sbi->s_lock);
1377 return err;
1378 }
1379
1380 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1381 {
1382 struct super_block *sb = dentry->d_sb;
1383 struct ext2_sb_info *sbi = EXT2_SB(sb);
1384 struct ext2_super_block *es = sbi->s_es;
1385 u64 fsid;
1386
1387 spin_lock(&sbi->s_lock);
1388
1389 if (test_opt (sb, MINIX_DF))
1390 sbi->s_overhead_last = 0;
1391 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1392 unsigned long i, overhead = 0;
1393 smp_rmb();
1394
1395 /*
1396 * Compute the overhead (FS structures). This is constant
1397 * for a given filesystem unless the number of block groups
1398 * changes so we cache the previous value until it does.
1399 */
1400
1401 /*
1402 * All of the blocks before first_data_block are
1403 * overhead
1404 */
1405 overhead = le32_to_cpu(es->s_first_data_block);
1406
1407 /*
1408 * Add the overhead attributed to the superblock and
1409 * block group descriptors. If the sparse superblocks
1410 * feature is turned on, then not all groups have this.
1411 */
1412 for (i = 0; i < sbi->s_groups_count; i++)
1413 overhead += ext2_bg_has_super(sb, i) +
1414 ext2_bg_num_gdb(sb, i);
1415
1416 /*
1417 * Every block group has an inode bitmap, a block
1418 * bitmap, and an inode table.
1419 */
1420 overhead += (sbi->s_groups_count *
1421 (2 + sbi->s_itb_per_group));
1422 sbi->s_overhead_last = overhead;
1423 smp_wmb();
1424 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1425 }
1426
1427 buf->f_type = EXT2_SUPER_MAGIC;
1428 buf->f_bsize = sb->s_blocksize;
1429 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1430 buf->f_bfree = ext2_count_free_blocks(sb);
1431 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1432 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1433 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1434 buf->f_bavail = 0;
1435 buf->f_files = le32_to_cpu(es->s_inodes_count);
1436 buf->f_ffree = ext2_count_free_inodes(sb);
1437 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1438 buf->f_namelen = EXT2_NAME_LEN;
1439 fsid = le64_to_cpup((void *)es->s_uuid) ^
1440 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1441 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1442 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1443 spin_unlock(&sbi->s_lock);
1444 return 0;
1445 }
1446
1447 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1448 int flags, const char *dev_name, void *data)
1449 {
1450 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1451 }
1452
1453 #ifdef CONFIG_QUOTA
1454
1455 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1456 * acquiring the locks... As quota files are never truncated and quota code
1457 * itself serializes the operations (and no one else should touch the files)
1458 * we don't have to be afraid of races */
1459 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1460 size_t len, loff_t off)
1461 {
1462 struct inode *inode = sb_dqopt(sb)->files[type];
1463 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1464 int err = 0;
1465 int offset = off & (sb->s_blocksize - 1);
1466 int tocopy;
1467 size_t toread;
1468 struct buffer_head tmp_bh;
1469 struct buffer_head *bh;
1470 loff_t i_size = i_size_read(inode);
1471
1472 if (off > i_size)
1473 return 0;
1474 if (off+len > i_size)
1475 len = i_size-off;
1476 toread = len;
1477 while (toread > 0) {
1478 tocopy = sb->s_blocksize - offset < toread ?
1479 sb->s_blocksize - offset : toread;
1480
1481 tmp_bh.b_state = 0;
1482 tmp_bh.b_size = sb->s_blocksize;
1483 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1484 if (err < 0)
1485 return err;
1486 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1487 memset(data, 0, tocopy);
1488 else {
1489 bh = sb_bread(sb, tmp_bh.b_blocknr);
1490 if (!bh)
1491 return -EIO;
1492 memcpy(data, bh->b_data+offset, tocopy);
1493 brelse(bh);
1494 }
1495 offset = 0;
1496 toread -= tocopy;
1497 data += tocopy;
1498 blk++;
1499 }
1500 return len;
1501 }
1502
1503 /* Write to quotafile */
1504 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1505 const char *data, size_t len, loff_t off)
1506 {
1507 struct inode *inode = sb_dqopt(sb)->files[type];
1508 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1509 int err = 0;
1510 int offset = off & (sb->s_blocksize - 1);
1511 int tocopy;
1512 size_t towrite = len;
1513 struct buffer_head tmp_bh;
1514 struct buffer_head *bh;
1515
1516 while (towrite > 0) {
1517 tocopy = sb->s_blocksize - offset < towrite ?
1518 sb->s_blocksize - offset : towrite;
1519
1520 tmp_bh.b_state = 0;
1521 tmp_bh.b_size = sb->s_blocksize;
1522 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1523 if (err < 0)
1524 goto out;
1525 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1526 bh = sb_bread(sb, tmp_bh.b_blocknr);
1527 else
1528 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1529 if (unlikely(!bh)) {
1530 err = -EIO;
1531 goto out;
1532 }
1533 lock_buffer(bh);
1534 memcpy(bh->b_data+offset, data, tocopy);
1535 flush_dcache_page(bh->b_page);
1536 set_buffer_uptodate(bh);
1537 mark_buffer_dirty(bh);
1538 unlock_buffer(bh);
1539 brelse(bh);
1540 offset = 0;
1541 towrite -= tocopy;
1542 data += tocopy;
1543 blk++;
1544 }
1545 out:
1546 if (len == towrite)
1547 return err;
1548 if (inode->i_size < off+len-towrite)
1549 i_size_write(inode, off+len-towrite);
1550 inode->i_version++;
1551 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1552 mark_inode_dirty(inode);
1553 return len - towrite;
1554 }
1555
1556 #endif
1557
1558 static struct file_system_type ext2_fs_type = {
1559 .owner = THIS_MODULE,
1560 .name = "ext2",
1561 .mount = ext2_mount,
1562 .kill_sb = kill_block_super,
1563 .fs_flags = FS_REQUIRES_DEV,
1564 };
1565 MODULE_ALIAS_FS("ext2");
1566
1567 static int __init init_ext2_fs(void)
1568 {
1569 int err = init_ext2_xattr();
1570 if (err)
1571 return err;
1572 err = init_inodecache();
1573 if (err)
1574 goto out1;
1575 err = register_filesystem(&ext2_fs_type);
1576 if (err)
1577 goto out;
1578 return 0;
1579 out:
1580 destroy_inodecache();
1581 out1:
1582 exit_ext2_xattr();
1583 return err;
1584 }
1585
1586 static void __exit exit_ext2_fs(void)
1587 {
1588 unregister_filesystem(&ext2_fs_type);
1589 destroy_inodecache();
1590 exit_ext2_xattr();
1591 }
1592
1593 MODULE_AUTHOR("Remy Card and others");
1594 MODULE_DESCRIPTION("Second Extended Filesystem");
1595 MODULE_LICENSE("GPL");
1596 module_init(init_ext2_fs)
1597 module_exit(exit_ext2_fs)
Linux with added FPC-III support