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arm64: kgdb: Fix single-step exception handling oops
[linux/fpc-iii.git] / fs / ext2 / super.c
blob186912c9bf565c129d9d3bda98443e1c55471783
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 if (sbi->s_mb_cache) {
135 ext2_xattr_destroy_cache(sbi->s_mb_cache);
136 sbi->s_mb_cache = NULL;
137 }
138 if (!(sb->s_flags & MS_RDONLY)) {
139 struct ext2_super_block *es = sbi->s_es;
140
141 spin_lock(&sbi->s_lock);
142 es->s_state = cpu_to_le16(sbi->s_mount_state);
143 spin_unlock(&sbi->s_lock);
144 ext2_sync_super(sb, es, 1);
145 }
146 db_count = sbi->s_gdb_count;
147 for (i = 0; i < db_count; i++)
148 if (sbi->s_group_desc[i])
149 brelse (sbi->s_group_desc[i]);
150 kfree(sbi->s_group_desc);
151 kfree(sbi->s_debts);
152 percpu_counter_destroy(&sbi->s_freeblocks_counter);
153 percpu_counter_destroy(&sbi->s_freeinodes_counter);
154 percpu_counter_destroy(&sbi->s_dirs_counter);
155 brelse (sbi->s_sbh);
156 sb->s_fs_info = NULL;
157 kfree(sbi->s_blockgroup_lock);
158 kfree(sbi);
159 }
160
161 static struct kmem_cache * ext2_inode_cachep;
162
163 static struct inode *ext2_alloc_inode(struct super_block *sb)
164 {
165 struct ext2_inode_info *ei;
166 ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
167 if (!ei)
168 return NULL;
169 ei->i_block_alloc_info = NULL;
170 ei->vfs_inode.i_version = 1;
171 #ifdef CONFIG_QUOTA
172 memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
173 #endif
174
175 return &ei->vfs_inode;
176 }
177
178 static void ext2_i_callback(struct rcu_head *head)
179 {
180 struct inode *inode = container_of(head, struct inode, i_rcu);
181 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
182 }
183
184 static void ext2_destroy_inode(struct inode *inode)
185 {
186 call_rcu(&inode->i_rcu, ext2_i_callback);
187 }
188
189 static void init_once(void *foo)
190 {
191 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
192
193 rwlock_init(&ei->i_meta_lock);
194 #ifdef CONFIG_EXT2_FS_XATTR
195 init_rwsem(&ei->xattr_sem);
196 #endif
197 mutex_init(&ei->truncate_mutex);
198 #ifdef CONFIG_FS_DAX
199 init_rwsem(&ei->dax_sem);
200 #endif
201 inode_init_once(&ei->vfs_inode);
202 }
203
204 static int __init init_inodecache(void)
205 {
206 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
207 sizeof(struct ext2_inode_info),
208 0, (SLAB_RECLAIM_ACCOUNT|
209 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
210 init_once);
211 if (ext2_inode_cachep == NULL)
212 return -ENOMEM;
213 return 0;
214 }
215
216 static void destroy_inodecache(void)
217 {
218 /*
219 * Make sure all delayed rcu free inodes are flushed before we
220 * destroy cache.
221 */
222 rcu_barrier();
223 kmem_cache_destroy(ext2_inode_cachep);
224 }
225
226 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
227 {
228 struct super_block *sb = root->d_sb;
229 struct ext2_sb_info *sbi = EXT2_SB(sb);
230 struct ext2_super_block *es = sbi->s_es;
231 unsigned long def_mount_opts;
232
233 spin_lock(&sbi->s_lock);
234 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
235
236 if (sbi->s_sb_block != 1)
237 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
238 if (test_opt(sb, MINIX_DF))
239 seq_puts(seq, ",minixdf");
240 if (test_opt(sb, GRPID))
241 seq_puts(seq, ",grpid");
242 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
243 seq_puts(seq, ",nogrpid");
244 if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
245 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
246 seq_printf(seq, ",resuid=%u",
247 from_kuid_munged(&init_user_ns, sbi->s_resuid));
248 }
249 if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
250 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
251 seq_printf(seq, ",resgid=%u",
252 from_kgid_munged(&init_user_ns, sbi->s_resgid));
253 }
254 if (test_opt(sb, ERRORS_RO)) {
255 int def_errors = le16_to_cpu(es->s_errors);
256
257 if (def_errors == EXT2_ERRORS_PANIC ||
258 def_errors == EXT2_ERRORS_CONTINUE) {
259 seq_puts(seq, ",errors=remount-ro");
260 }
261 }
262 if (test_opt(sb, ERRORS_CONT))
263 seq_puts(seq, ",errors=continue");
264 if (test_opt(sb, ERRORS_PANIC))
265 seq_puts(seq, ",errors=panic");
266 if (test_opt(sb, NO_UID32))
267 seq_puts(seq, ",nouid32");
268 if (test_opt(sb, DEBUG))
269 seq_puts(seq, ",debug");
270 if (test_opt(sb, OLDALLOC))
271 seq_puts(seq, ",oldalloc");
272
273 #ifdef CONFIG_EXT2_FS_XATTR
274 if (test_opt(sb, XATTR_USER))
275 seq_puts(seq, ",user_xattr");
276 if (!test_opt(sb, XATTR_USER) &&
277 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
278 seq_puts(seq, ",nouser_xattr");
279 }
280 #endif
281
282 #ifdef CONFIG_EXT2_FS_POSIX_ACL
283 if (test_opt(sb, POSIX_ACL))
284 seq_puts(seq, ",acl");
285 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
286 seq_puts(seq, ",noacl");
287 #endif
288
289 if (test_opt(sb, NOBH))
290 seq_puts(seq, ",nobh");
291
292 #if defined(CONFIG_QUOTA)
293 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
294 seq_puts(seq, ",usrquota");
295
296 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
297 seq_puts(seq, ",grpquota");
298 #endif
299
300 #ifdef CONFIG_FS_DAX
301 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
302 seq_puts(seq, ",xip");
303 if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
304 seq_puts(seq, ",dax");
305 #endif
306
307 if (!test_opt(sb, RESERVATION))
308 seq_puts(seq, ",noreservation");
309
310 spin_unlock(&sbi->s_lock);
311 return 0;
312 }
313
314 #ifdef CONFIG_QUOTA
315 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
316 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
317 static struct dquot **ext2_get_dquots(struct inode *inode)
318 {
319 return EXT2_I(inode)->i_dquot;
320 }
321 #endif
322
323 static const struct super_operations ext2_sops = {
324 .alloc_inode = ext2_alloc_inode,
325 .destroy_inode = ext2_destroy_inode,
326 .write_inode = ext2_write_inode,
327 .evict_inode = ext2_evict_inode,
328 .put_super = ext2_put_super,
329 .sync_fs = ext2_sync_fs,
330 .freeze_fs = ext2_freeze,
331 .unfreeze_fs = ext2_unfreeze,
332 .statfs = ext2_statfs,
333 .remount_fs = ext2_remount,
334 .show_options = ext2_show_options,
335 #ifdef CONFIG_QUOTA
336 .quota_read = ext2_quota_read,
337 .quota_write = ext2_quota_write,
338 .get_dquots = ext2_get_dquots,
339 #endif
340 };
341
342 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
343 u64 ino, u32 generation)
344 {
345 struct inode *inode;
346
347 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
348 return ERR_PTR(-ESTALE);
349 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
350 return ERR_PTR(-ESTALE);
351
352 /*
353 * ext2_iget isn't quite right if the inode is currently unallocated!
354 * However ext2_iget currently does appropriate checks to handle stale
355 * inodes so everything is OK.
356 */
357 inode = ext2_iget(sb, ino);
358 if (IS_ERR(inode))
359 return ERR_CAST(inode);
360 if (generation && inode->i_generation != generation) {
361 /* we didn't find the right inode.. */
362 iput(inode);
363 return ERR_PTR(-ESTALE);
364 }
365 return inode;
366 }
367
368 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
369 int fh_len, int fh_type)
370 {
371 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
372 ext2_nfs_get_inode);
373 }
374
375 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
376 int fh_len, int fh_type)
377 {
378 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
379 ext2_nfs_get_inode);
380 }
381
382 static const struct export_operations ext2_export_ops = {
383 .fh_to_dentry = ext2_fh_to_dentry,
384 .fh_to_parent = ext2_fh_to_parent,
385 .get_parent = ext2_get_parent,
386 };
387
388 static unsigned long get_sb_block(void **data)
389 {
390 unsigned long sb_block;
391 char *options = (char *) *data;
392
393 if (!options || strncmp(options, "sb=", 3) != 0)
394 return 1; /* Default location */
395 options += 3;
396 sb_block = simple_strtoul(options, &options, 0);
397 if (*options && *options != ',') {
398 printk("EXT2-fs: Invalid sb specification: %s\n",
399 (char *) *data);
400 return 1;
401 }
402 if (*options == ',')
403 options++;
404 *data = (void *) options;
405 return sb_block;
406 }
407
408 enum {
409 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
410 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
411 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
412 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
413 Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
414 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
415 };
416
417 static const match_table_t tokens = {
418 {Opt_bsd_df, "bsddf"},
419 {Opt_minix_df, "minixdf"},
420 {Opt_grpid, "grpid"},
421 {Opt_grpid, "bsdgroups"},
422 {Opt_nogrpid, "nogrpid"},
423 {Opt_nogrpid, "sysvgroups"},
424 {Opt_resgid, "resgid=%u"},
425 {Opt_resuid, "resuid=%u"},
426 {Opt_sb, "sb=%u"},
427 {Opt_err_cont, "errors=continue"},
428 {Opt_err_panic, "errors=panic"},
429 {Opt_err_ro, "errors=remount-ro"},
430 {Opt_nouid32, "nouid32"},
431 {Opt_nocheck, "check=none"},
432 {Opt_nocheck, "nocheck"},
433 {Opt_debug, "debug"},
434 {Opt_oldalloc, "oldalloc"},
435 {Opt_orlov, "orlov"},
436 {Opt_nobh, "nobh"},
437 {Opt_user_xattr, "user_xattr"},
438 {Opt_nouser_xattr, "nouser_xattr"},
439 {Opt_acl, "acl"},
440 {Opt_noacl, "noacl"},
441 {Opt_xip, "xip"},
442 {Opt_dax, "dax"},
443 {Opt_grpquota, "grpquota"},
444 {Opt_ignore, "noquota"},
445 {Opt_quota, "quota"},
446 {Opt_usrquota, "usrquota"},
447 {Opt_reservation, "reservation"},
448 {Opt_noreservation, "noreservation"},
449 {Opt_err, NULL}
450 };
451
452 static int parse_options(char *options, struct super_block *sb)
453 {
454 char *p;
455 struct ext2_sb_info *sbi = EXT2_SB(sb);
456 substring_t args[MAX_OPT_ARGS];
457 int option;
458 kuid_t uid;
459 kgid_t gid;
460
461 if (!options)
462 return 1;
463
464 while ((p = strsep (&options, ",")) != NULL) {
465 int token;
466 if (!*p)
467 continue;
468
469 token = match_token(p, tokens, args);
470 switch (token) {
471 case Opt_bsd_df:
472 clear_opt (sbi->s_mount_opt, MINIX_DF);
473 break;
474 case Opt_minix_df:
475 set_opt (sbi->s_mount_opt, MINIX_DF);
476 break;
477 case Opt_grpid:
478 set_opt (sbi->s_mount_opt, GRPID);
479 break;
480 case Opt_nogrpid:
481 clear_opt (sbi->s_mount_opt, GRPID);
482 break;
483 case Opt_resuid:
484 if (match_int(&args[0], &option))
485 return 0;
486 uid = make_kuid(current_user_ns(), option);
487 if (!uid_valid(uid)) {
488 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
489 return 0;
490
491 }
492 sbi->s_resuid = uid;
493 break;
494 case Opt_resgid:
495 if (match_int(&args[0], &option))
496 return 0;
497 gid = make_kgid(current_user_ns(), option);
498 if (!gid_valid(gid)) {
499 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
500 return 0;
501 }
502 sbi->s_resgid = gid;
503 break;
504 case Opt_sb:
505 /* handled by get_sb_block() instead of here */
506 /* *sb_block = match_int(&args[0]); */
507 break;
508 case Opt_err_panic:
509 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
510 clear_opt (sbi->s_mount_opt, ERRORS_RO);
511 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
512 break;
513 case Opt_err_ro:
514 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
515 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
516 set_opt (sbi->s_mount_opt, ERRORS_RO);
517 break;
518 case Opt_err_cont:
519 clear_opt (sbi->s_mount_opt, ERRORS_RO);
520 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
521 set_opt (sbi->s_mount_opt, ERRORS_CONT);
522 break;
523 case Opt_nouid32:
524 set_opt (sbi->s_mount_opt, NO_UID32);
525 break;
526 case Opt_nocheck:
527 clear_opt (sbi->s_mount_opt, CHECK);
528 break;
529 case Opt_debug:
530 set_opt (sbi->s_mount_opt, DEBUG);
531 break;
532 case Opt_oldalloc:
533 set_opt (sbi->s_mount_opt, OLDALLOC);
534 break;
535 case Opt_orlov:
536 clear_opt (sbi->s_mount_opt, OLDALLOC);
537 break;
538 case Opt_nobh:
539 set_opt (sbi->s_mount_opt, NOBH);
540 break;
541 #ifdef CONFIG_EXT2_FS_XATTR
542 case Opt_user_xattr:
543 set_opt (sbi->s_mount_opt, XATTR_USER);
544 break;
545 case Opt_nouser_xattr:
546 clear_opt (sbi->s_mount_opt, XATTR_USER);
547 break;
548 #else
549 case Opt_user_xattr:
550 case Opt_nouser_xattr:
551 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
552 "not supported");
553 break;
554 #endif
555 #ifdef CONFIG_EXT2_FS_POSIX_ACL
556 case Opt_acl:
557 set_opt(sbi->s_mount_opt, POSIX_ACL);
558 break;
559 case Opt_noacl:
560 clear_opt(sbi->s_mount_opt, POSIX_ACL);
561 break;
562 #else
563 case Opt_acl:
564 case Opt_noacl:
565 ext2_msg(sb, KERN_INFO,
566 "(no)acl options not supported");
567 break;
568 #endif
569 case Opt_xip:
570 ext2_msg(sb, KERN_INFO, "use dax instead of xip");
571 set_opt(sbi->s_mount_opt, XIP);
572 /* Fall through */
573 case Opt_dax:
574 #ifdef CONFIG_FS_DAX
575 ext2_msg(sb, KERN_WARNING,
576 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
577 set_opt(sbi->s_mount_opt, DAX);
578 #else
579 ext2_msg(sb, KERN_INFO, "dax option not supported");
580 #endif
581 break;
582
583 #if defined(CONFIG_QUOTA)
584 case Opt_quota:
585 case Opt_usrquota:
586 set_opt(sbi->s_mount_opt, USRQUOTA);
587 break;
588
589 case Opt_grpquota:
590 set_opt(sbi->s_mount_opt, GRPQUOTA);
591 break;
592 #else
593 case Opt_quota:
594 case Opt_usrquota:
595 case Opt_grpquota:
596 ext2_msg(sb, KERN_INFO,
597 "quota operations not supported");
598 break;
599 #endif
600
601 case Opt_reservation:
602 set_opt(sbi->s_mount_opt, RESERVATION);
603 ext2_msg(sb, KERN_INFO, "reservations ON");
604 break;
605 case Opt_noreservation:
606 clear_opt(sbi->s_mount_opt, RESERVATION);
607 ext2_msg(sb, KERN_INFO, "reservations OFF");
608 break;
609 case Opt_ignore:
610 break;
611 default:
612 return 0;
613 }
614 }
615 return 1;
616 }
617
618 static int ext2_setup_super (struct super_block * sb,
619 struct ext2_super_block * es,
620 int read_only)
621 {
622 int res = 0;
623 struct ext2_sb_info *sbi = EXT2_SB(sb);
624
625 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
626 ext2_msg(sb, KERN_ERR,
627 "error: revision level too high, "
628 "forcing read-only mode");
629 res = MS_RDONLY;
630 }
631 if (read_only)
632 return res;
633 if (!(sbi->s_mount_state & EXT2_VALID_FS))
634 ext2_msg(sb, KERN_WARNING,
635 "warning: mounting unchecked fs, "
636 "running e2fsck is recommended");
637 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
638 ext2_msg(sb, KERN_WARNING,
639 "warning: mounting fs with errors, "
640 "running e2fsck is recommended");
641 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
642 le16_to_cpu(es->s_mnt_count) >=
643 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
644 ext2_msg(sb, KERN_WARNING,
645 "warning: maximal mount count reached, "
646 "running e2fsck is recommended");
647 else if (le32_to_cpu(es->s_checkinterval) &&
648 (le32_to_cpu(es->s_lastcheck) +
649 le32_to_cpu(es->s_checkinterval) <= get_seconds()))
650 ext2_msg(sb, KERN_WARNING,
651 "warning: checktime reached, "
652 "running e2fsck is recommended");
653 if (!le16_to_cpu(es->s_max_mnt_count))
654 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
655 le16_add_cpu(&es->s_mnt_count, 1);
656 if (test_opt (sb, DEBUG))
657 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
658 "bpg=%lu, ipg=%lu, mo=%04lx]",
659 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
660 sbi->s_frag_size,
661 sbi->s_groups_count,
662 EXT2_BLOCKS_PER_GROUP(sb),
663 EXT2_INODES_PER_GROUP(sb),
664 sbi->s_mount_opt);
665 return res;
666 }
667
668 static int ext2_check_descriptors(struct super_block *sb)
669 {
670 int i;
671 struct ext2_sb_info *sbi = EXT2_SB(sb);
672
673 ext2_debug ("Checking group descriptors");
674
675 for (i = 0; i < sbi->s_groups_count; i++) {
676 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
677 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
678 ext2_fsblk_t last_block;
679
680 if (i == sbi->s_groups_count - 1)
681 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
682 else
683 last_block = first_block +
684 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
685
686 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
687 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
688 {
689 ext2_error (sb, "ext2_check_descriptors",
690 "Block bitmap for group %d"
691 " not in group (block %lu)!",
692 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
693 return 0;
694 }
695 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
696 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
697 {
698 ext2_error (sb, "ext2_check_descriptors",
699 "Inode bitmap for group %d"
700 " not in group (block %lu)!",
701 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
702 return 0;
703 }
704 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
705 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
706 last_block)
707 {
708 ext2_error (sb, "ext2_check_descriptors",
709 "Inode table for group %d"
710 " not in group (block %lu)!",
711 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
712 return 0;
713 }
714 }
715 return 1;
716 }
717
718 /*
719 * Maximal file size. There is a direct, and {,double-,triple-}indirect
720 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
721 * We need to be 1 filesystem block less than the 2^32 sector limit.
722 */
723 static loff_t ext2_max_size(int bits)
724 {
725 loff_t res = EXT2_NDIR_BLOCKS;
726 int meta_blocks;
727 unsigned int upper_limit;
728 unsigned int ppb = 1 << (bits-2);
729
730 /* This is calculated to be the largest file size for a
731 * dense, file such that the total number of
732 * sectors in the file, including data and all indirect blocks,
733 * does not exceed 2^32 -1
734 * __u32 i_blocks representing the total number of
735 * 512 bytes blocks of the file
736 */
737 upper_limit = (1LL << 32) - 1;
738
739 /* total blocks in file system block size */
740 upper_limit >>= (bits - 9);
741
742 /* Compute how many blocks we can address by block tree */
743 res += 1LL << (bits-2);
744 res += 1LL << (2*(bits-2));
745 res += 1LL << (3*(bits-2));
746 /* Does block tree limit file size? */
747 if (res < upper_limit)
748 goto check_lfs;
749
750 res = upper_limit;
751 /* How many metadata blocks are needed for addressing upper_limit? */
752 upper_limit -= EXT2_NDIR_BLOCKS;
753 /* indirect blocks */
754 meta_blocks = 1;
755 upper_limit -= ppb;
756 /* double indirect blocks */
757 if (upper_limit < ppb * ppb) {
758 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
759 res -= meta_blocks;
760 goto check_lfs;
761 }
762 meta_blocks += 1 + ppb;
763 upper_limit -= ppb * ppb;
764 /* tripple indirect blocks for the rest */
765 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
766 DIV_ROUND_UP(upper_limit, ppb*ppb);
767 res -= meta_blocks;
768 check_lfs:
769 res <<= bits;
770 if (res > MAX_LFS_FILESIZE)
771 res = MAX_LFS_FILESIZE;
772
773 return res;
774 }
775
776 static unsigned long descriptor_loc(struct super_block *sb,
777 unsigned long logic_sb_block,
778 int nr)
779 {
780 struct ext2_sb_info *sbi = EXT2_SB(sb);
781 unsigned long bg, first_meta_bg;
782 int has_super = 0;
783
784 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
785
786 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
787 nr < first_meta_bg)
788 return (logic_sb_block + nr + 1);
789 bg = sbi->s_desc_per_block * nr;
790 if (ext2_bg_has_super(sb, bg))
791 has_super = 1;
792
793 return ext2_group_first_block_no(sb, bg) + has_super;
794 }
795
796 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
797 {
798 struct buffer_head * bh;
799 struct ext2_sb_info * sbi;
800 struct ext2_super_block * es;
801 struct inode *root;
802 unsigned long block;
803 unsigned long sb_block = get_sb_block(&data);
804 unsigned long logic_sb_block;
805 unsigned long offset = 0;
806 unsigned long def_mount_opts;
807 long ret = -EINVAL;
808 int blocksize = BLOCK_SIZE;
809 int db_count;
810 int i, j;
811 __le32 features;
812 int err;
813
814 err = -ENOMEM;
815 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
816 if (!sbi)
817 goto failed;
818
819 sbi->s_blockgroup_lock =
820 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
821 if (!sbi->s_blockgroup_lock) {
822 kfree(sbi);
823 goto failed;
824 }
825 sb->s_fs_info = sbi;
826 sbi->s_sb_block = sb_block;
827
828 spin_lock_init(&sbi->s_lock);
829
830 /*
831 * See what the current blocksize for the device is, and
832 * use that as the blocksize. Otherwise (or if the blocksize
833 * is smaller than the default) use the default.
834 * This is important for devices that have a hardware
835 * sectorsize that is larger than the default.
836 */
837 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
838 if (!blocksize) {
839 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
840 goto failed_sbi;
841 }
842
843 /*
844 * If the superblock doesn't start on a hardware sector boundary,
845 * calculate the offset.
846 */
847 if (blocksize != BLOCK_SIZE) {
848 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
849 offset = (sb_block*BLOCK_SIZE) % blocksize;
850 } else {
851 logic_sb_block = sb_block;
852 }
853
854 if (!(bh = sb_bread(sb, logic_sb_block))) {
855 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
856 goto failed_sbi;
857 }
858 /*
859 * Note: s_es must be initialized as soon as possible because
860 * some ext2 macro-instructions depend on its value
861 */
862 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
863 sbi->s_es = es;
864 sb->s_magic = le16_to_cpu(es->s_magic);
865
866 if (sb->s_magic != EXT2_SUPER_MAGIC)
867 goto cantfind_ext2;
868
869 /* Set defaults before we parse the mount options */
870 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
871 if (def_mount_opts & EXT2_DEFM_DEBUG)
872 set_opt(sbi->s_mount_opt, DEBUG);
873 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
874 set_opt(sbi->s_mount_opt, GRPID);
875 if (def_mount_opts & EXT2_DEFM_UID16)
876 set_opt(sbi->s_mount_opt, NO_UID32);
877 #ifdef CONFIG_EXT2_FS_XATTR
878 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
879 set_opt(sbi->s_mount_opt, XATTR_USER);
880 #endif
881 #ifdef CONFIG_EXT2_FS_POSIX_ACL
882 if (def_mount_opts & EXT2_DEFM_ACL)
883 set_opt(sbi->s_mount_opt, POSIX_ACL);
884 #endif
885
886 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
887 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
888 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
889 set_opt(sbi->s_mount_opt, ERRORS_CONT);
890 else
891 set_opt(sbi->s_mount_opt, ERRORS_RO);
892
893 sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
894 sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
895
896 set_opt(sbi->s_mount_opt, RESERVATION);
897
898 if (!parse_options((char *) data, sb))
899 goto failed_mount;
900
901 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
902 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
903 MS_POSIXACL : 0);
904 sb->s_iflags |= SB_I_CGROUPWB;
905
906 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
907 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
908 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
909 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
910 ext2_msg(sb, KERN_WARNING,
911 "warning: feature flags set on rev 0 fs, "
912 "running e2fsck is recommended");
913 /*
914 * Check feature flags regardless of the revision level, since we
915 * previously didn't change the revision level when setting the flags,
916 * so there is a chance incompat flags are set on a rev 0 filesystem.
917 */
918 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
919 if (features) {
920 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
921 "unsupported optional features (%x)",
922 le32_to_cpu(features));
923 goto failed_mount;
924 }
925 if (!(sb->s_flags & MS_RDONLY) &&
926 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
927 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
928 "unsupported optional features (%x)",
929 le32_to_cpu(features));
930 goto failed_mount;
931 }
932
933 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
934
935 if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
936 err = bdev_dax_supported(sb, blocksize);
937 if (err)
938 goto failed_mount;
939 }
940
941 /* If the blocksize doesn't match, re-read the thing.. */
942 if (sb->s_blocksize != blocksize) {
943 brelse(bh);
944
945 if (!sb_set_blocksize(sb, blocksize)) {
946 ext2_msg(sb, KERN_ERR,
947 "error: bad blocksize %d", blocksize);
948 goto failed_sbi;
949 }
950
951 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
952 offset = (sb_block*BLOCK_SIZE) % blocksize;
953 bh = sb_bread(sb, logic_sb_block);
954 if(!bh) {
955 ext2_msg(sb, KERN_ERR, "error: couldn't read"
956 "superblock on 2nd try");
957 goto failed_sbi;
958 }
959 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
960 sbi->s_es = es;
961 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
962 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
963 goto failed_mount;
964 }
965 }
966
967 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
968 sb->s_max_links = EXT2_LINK_MAX;
969
970 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
971 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
972 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
973 } else {
974 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
975 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
976 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
977 !is_power_of_2(sbi->s_inode_size) ||
978 (sbi->s_inode_size > blocksize)) {
979 ext2_msg(sb, KERN_ERR,
980 "error: unsupported inode size: %d",
981 sbi->s_inode_size);
982 goto failed_mount;
983 }
984 }
985
986 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
987 le32_to_cpu(es->s_log_frag_size);
988 if (sbi->s_frag_size == 0)
989 goto cantfind_ext2;
990 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
991
992 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
993 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
994 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
995
996 if (EXT2_INODE_SIZE(sb) == 0)
997 goto cantfind_ext2;
998 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
999 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1000 goto cantfind_ext2;
1001 sbi->s_itb_per_group = sbi->s_inodes_per_group /
1002 sbi->s_inodes_per_block;
1003 sbi->s_desc_per_block = sb->s_blocksize /
1004 sizeof (struct ext2_group_desc);
1005 sbi->s_sbh = bh;
1006 sbi->s_mount_state = le16_to_cpu(es->s_state);
1007 sbi->s_addr_per_block_bits =
1008 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1009 sbi->s_desc_per_block_bits =
1010 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1011
1012 if (sb->s_magic != EXT2_SUPER_MAGIC)
1013 goto cantfind_ext2;
1014
1015 if (sb->s_blocksize != bh->b_size) {
1016 if (!silent)
1017 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1018 goto failed_mount;
1019 }
1020
1021 if (sb->s_blocksize != sbi->s_frag_size) {
1022 ext2_msg(sb, KERN_ERR,
1023 "error: fragsize %lu != blocksize %lu"
1024 "(not supported yet)",
1025 sbi->s_frag_size, sb->s_blocksize);
1026 goto failed_mount;
1027 }
1028
1029 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1030 ext2_msg(sb, KERN_ERR,
1031 "error: #blocks per group too big: %lu",
1032 sbi->s_blocks_per_group);
1033 goto failed_mount;
1034 }
1035 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1036 ext2_msg(sb, KERN_ERR,
1037 "error: #fragments per group too big: %lu",
1038 sbi->s_frags_per_group);
1039 goto failed_mount;
1040 }
1041 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1042 ext2_msg(sb, KERN_ERR,
1043 "error: #inodes per group too big: %lu",
1044 sbi->s_inodes_per_group);
1045 goto failed_mount;
1046 }
1047
1048 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1049 goto cantfind_ext2;
1050 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1051 le32_to_cpu(es->s_first_data_block) - 1)
1052 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1053 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1054 EXT2_DESC_PER_BLOCK(sb);
1055 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1056 if (sbi->s_group_desc == NULL) {
1057 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1058 goto failed_mount;
1059 }
1060 bgl_lock_init(sbi->s_blockgroup_lock);
1061 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1062 if (!sbi->s_debts) {
1063 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1064 goto failed_mount_group_desc;
1065 }
1066 for (i = 0; i < db_count; i++) {
1067 block = descriptor_loc(sb, logic_sb_block, i);
1068 sbi->s_group_desc[i] = sb_bread(sb, block);
1069 if (!sbi->s_group_desc[i]) {
1070 for (j = 0; j < i; j++)
1071 brelse (sbi->s_group_desc[j]);
1072 ext2_msg(sb, KERN_ERR,
1073 "error: unable to read group descriptors");
1074 goto failed_mount_group_desc;
1075 }
1076 }
1077 if (!ext2_check_descriptors (sb)) {
1078 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1079 goto failed_mount2;
1080 }
1081 sbi->s_gdb_count = db_count;
1082 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1083 spin_lock_init(&sbi->s_next_gen_lock);
1084
1085 /* per fileystem reservation list head & lock */
1086 spin_lock_init(&sbi->s_rsv_window_lock);
1087 sbi->s_rsv_window_root = RB_ROOT;
1088 /*
1089 * Add a single, static dummy reservation to the start of the
1090 * reservation window list --- it gives us a placeholder for
1091 * append-at-start-of-list which makes the allocation logic
1092 * _much_ simpler.
1093 */
1094 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1095 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1096 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1097 sbi->s_rsv_window_head.rsv_goal_size = 0;
1098 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1099
1100 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1101 ext2_count_free_blocks(sb), GFP_KERNEL);
1102 if (!err) {
1103 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1104 ext2_count_free_inodes(sb), GFP_KERNEL);
1105 }
1106 if (!err) {
1107 err = percpu_counter_init(&sbi->s_dirs_counter,
1108 ext2_count_dirs(sb), GFP_KERNEL);
1109 }
1110 if (err) {
1111 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1112 goto failed_mount3;
1113 }
1114
1115 #ifdef CONFIG_EXT2_FS_XATTR
1116 sbi->s_mb_cache = ext2_xattr_create_cache();
1117 if (!sbi->s_mb_cache) {
1118 ext2_msg(sb, KERN_ERR, "Failed to create an mb_cache");
1119 goto failed_mount3;
1120 }
1121 #endif
1122 /*
1123 * set up enough so that it can read an inode
1124 */
1125 sb->s_op = &ext2_sops;
1126 sb->s_export_op = &ext2_export_ops;
1127 sb->s_xattr = ext2_xattr_handlers;
1128
1129 #ifdef CONFIG_QUOTA
1130 sb->dq_op = &dquot_operations;
1131 sb->s_qcop = &dquot_quotactl_ops;
1132 sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1133 #endif
1134
1135 root = ext2_iget(sb, EXT2_ROOT_INO);
1136 if (IS_ERR(root)) {
1137 ret = PTR_ERR(root);
1138 goto failed_mount3;
1139 }
1140 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1141 iput(root);
1142 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1143 goto failed_mount3;
1144 }
1145
1146 sb->s_root = d_make_root(root);
1147 if (!sb->s_root) {
1148 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1149 ret = -ENOMEM;
1150 goto failed_mount3;
1151 }
1152 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1153 ext2_msg(sb, KERN_WARNING,
1154 "warning: mounting ext3 filesystem as ext2");
1155 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1156 sb->s_flags |= MS_RDONLY;
1157 ext2_write_super(sb);
1158 return 0;
1159
1160 cantfind_ext2:
1161 if (!silent)
1162 ext2_msg(sb, KERN_ERR,
1163 "error: can't find an ext2 filesystem on dev %s.",
1164 sb->s_id);
1165 goto failed_mount;
1166 failed_mount3:
1167 if (sbi->s_mb_cache)
1168 ext2_xattr_destroy_cache(sbi->s_mb_cache);
1169 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1170 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1171 percpu_counter_destroy(&sbi->s_dirs_counter);
1172 failed_mount2:
1173 for (i = 0; i < db_count; i++)
1174 brelse(sbi->s_group_desc[i]);
1175 failed_mount_group_desc:
1176 kfree(sbi->s_group_desc);
1177 kfree(sbi->s_debts);
1178 failed_mount:
1179 brelse(bh);
1180 failed_sbi:
1181 sb->s_fs_info = NULL;
1182 kfree(sbi->s_blockgroup_lock);
1183 kfree(sbi);
1184 failed:
1185 return ret;
1186 }
1187
1188 static void ext2_clear_super_error(struct super_block *sb)
1189 {
1190 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1191
1192 if (buffer_write_io_error(sbh)) {
1193 /*
1194 * Oh, dear. A previous attempt to write the
1195 * superblock failed. This could happen because the
1196 * USB device was yanked out. Or it could happen to
1197 * be a transient write error and maybe the block will
1198 * be remapped. Nothing we can do but to retry the
1199 * write and hope for the best.
1200 */
1201 ext2_msg(sb, KERN_ERR,
1202 "previous I/O error to superblock detected\n");
1203 clear_buffer_write_io_error(sbh);
1204 set_buffer_uptodate(sbh);
1205 }
1206 }
1207
1208 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1209 int wait)
1210 {
1211 ext2_clear_super_error(sb);
1212 spin_lock(&EXT2_SB(sb)->s_lock);
1213 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1214 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1215 es->s_wtime = cpu_to_le32(get_seconds());
1216 /* unlock before we do IO */
1217 spin_unlock(&EXT2_SB(sb)->s_lock);
1218 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1219 if (wait)
1220 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1221 }
1222
1223 /*
1224 * In the second extended file system, it is not necessary to
1225 * write the super block since we use a mapping of the
1226 * disk super block in a buffer.
1227 *
1228 * However, this function is still used to set the fs valid
1229 * flags to 0. We need to set this flag to 0 since the fs
1230 * may have been checked while mounted and e2fsck may have
1231 * set s_state to EXT2_VALID_FS after some corrections.
1232 */
1233 static int ext2_sync_fs(struct super_block *sb, int wait)
1234 {
1235 struct ext2_sb_info *sbi = EXT2_SB(sb);
1236 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1237
1238 /*
1239 * Write quota structures to quota file, sync_blockdev() will write
1240 * them to disk later
1241 */
1242 dquot_writeback_dquots(sb, -1);
1243
1244 spin_lock(&sbi->s_lock);
1245 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1246 ext2_debug("setting valid to 0\n");
1247 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1248 }
1249 spin_unlock(&sbi->s_lock);
1250 ext2_sync_super(sb, es, wait);
1251 return 0;
1252 }
1253
1254 static int ext2_freeze(struct super_block *sb)
1255 {
1256 struct ext2_sb_info *sbi = EXT2_SB(sb);
1257
1258 /*
1259 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1260 * because we have unattached inodes and thus filesystem is not fully
1261 * consistent.
1262 */
1263 if (atomic_long_read(&sb->s_remove_count)) {
1264 ext2_sync_fs(sb, 1);
1265 return 0;
1266 }
1267 /* Set EXT2_FS_VALID flag */
1268 spin_lock(&sbi->s_lock);
1269 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1270 spin_unlock(&sbi->s_lock);
1271 ext2_sync_super(sb, sbi->s_es, 1);
1272
1273 return 0;
1274 }
1275
1276 static int ext2_unfreeze(struct super_block *sb)
1277 {
1278 /* Just write sb to clear EXT2_VALID_FS flag */
1279 ext2_write_super(sb);
1280
1281 return 0;
1282 }
1283
1284 void ext2_write_super(struct super_block *sb)
1285 {
1286 if (!(sb->s_flags & MS_RDONLY))
1287 ext2_sync_fs(sb, 1);
1288 }
1289
1290 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1291 {
1292 struct ext2_sb_info * sbi = EXT2_SB(sb);
1293 struct ext2_super_block * es;
1294 struct ext2_mount_options old_opts;
1295 unsigned long old_sb_flags;
1296 int err;
1297
1298 sync_filesystem(sb);
1299 spin_lock(&sbi->s_lock);
1300
1301 /* Store the old options */
1302 old_sb_flags = sb->s_flags;
1303 old_opts.s_mount_opt = sbi->s_mount_opt;
1304 old_opts.s_resuid = sbi->s_resuid;
1305 old_opts.s_resgid = sbi->s_resgid;
1306
1307 /*
1308 * Allow the "check" option to be passed as a remount option.
1309 */
1310 if (!parse_options(data, sb)) {
1311 err = -EINVAL;
1312 goto restore_opts;
1313 }
1314
1315 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1316 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1317
1318 es = sbi->s_es;
1319 if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1320 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1321 "dax flag with busy inodes while remounting");
1322 sbi->s_mount_opt ^= EXT2_MOUNT_DAX;
1323 }
1324 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1325 spin_unlock(&sbi->s_lock);
1326 return 0;
1327 }
1328 if (*flags & MS_RDONLY) {
1329 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1330 !(sbi->s_mount_state & EXT2_VALID_FS)) {
1331 spin_unlock(&sbi->s_lock);
1332 return 0;
1333 }
1334
1335 /*
1336 * OK, we are remounting a valid rw partition rdonly, so set
1337 * the rdonly flag and then mark the partition as valid again.
1338 */
1339 es->s_state = cpu_to_le16(sbi->s_mount_state);
1340 es->s_mtime = cpu_to_le32(get_seconds());
1341 spin_unlock(&sbi->s_lock);
1342
1343 err = dquot_suspend(sb, -1);
1344 if (err < 0) {
1345 spin_lock(&sbi->s_lock);
1346 goto restore_opts;
1347 }
1348
1349 ext2_sync_super(sb, es, 1);
1350 } else {
1351 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1352 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1353 if (ret) {
1354 ext2_msg(sb, KERN_WARNING,
1355 "warning: couldn't remount RDWR because of "
1356 "unsupported optional features (%x).",
1357 le32_to_cpu(ret));
1358 err = -EROFS;
1359 goto restore_opts;
1360 }
1361 /*
1362 * Mounting a RDONLY partition read-write, so reread and
1363 * store the current valid flag. (It may have been changed
1364 * by e2fsck since we originally mounted the partition.)
1365 */
1366 sbi->s_mount_state = le16_to_cpu(es->s_state);
1367 if (!ext2_setup_super (sb, es, 0))
1368 sb->s_flags &= ~MS_RDONLY;
1369 spin_unlock(&sbi->s_lock);
1370
1371 ext2_write_super(sb);
1372
1373 dquot_resume(sb, -1);
1374 }
1375
1376 return 0;
1377 restore_opts:
1378 sbi->s_mount_opt = old_opts.s_mount_opt;
1379 sbi->s_resuid = old_opts.s_resuid;
1380 sbi->s_resgid = old_opts.s_resgid;
1381 sb->s_flags = old_sb_flags;
1382 spin_unlock(&sbi->s_lock);
1383 return err;
1384 }
1385
1386 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1387 {
1388 struct super_block *sb = dentry->d_sb;
1389 struct ext2_sb_info *sbi = EXT2_SB(sb);
1390 struct ext2_super_block *es = sbi->s_es;
1391 u64 fsid;
1392
1393 spin_lock(&sbi->s_lock);
1394
1395 if (test_opt (sb, MINIX_DF))
1396 sbi->s_overhead_last = 0;
1397 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1398 unsigned long i, overhead = 0;
1399 smp_rmb();
1400
1401 /*
1402 * Compute the overhead (FS structures). This is constant
1403 * for a given filesystem unless the number of block groups
1404 * changes so we cache the previous value until it does.
1405 */
1406
1407 /*
1408 * All of the blocks before first_data_block are
1409 * overhead
1410 */
1411 overhead = le32_to_cpu(es->s_first_data_block);
1412
1413 /*
1414 * Add the overhead attributed to the superblock and
1415 * block group descriptors. If the sparse superblocks
1416 * feature is turned on, then not all groups have this.
1417 */
1418 for (i = 0; i < sbi->s_groups_count; i++)
1419 overhead += ext2_bg_has_super(sb, i) +
1420 ext2_bg_num_gdb(sb, i);
1421
1422 /*
1423 * Every block group has an inode bitmap, a block
1424 * bitmap, and an inode table.
1425 */
1426 overhead += (sbi->s_groups_count *
1427 (2 + sbi->s_itb_per_group));
1428 sbi->s_overhead_last = overhead;
1429 smp_wmb();
1430 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1431 }
1432
1433 buf->f_type = EXT2_SUPER_MAGIC;
1434 buf->f_bsize = sb->s_blocksize;
1435 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1436 buf->f_bfree = ext2_count_free_blocks(sb);
1437 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1438 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1439 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1440 buf->f_bavail = 0;
1441 buf->f_files = le32_to_cpu(es->s_inodes_count);
1442 buf->f_ffree = ext2_count_free_inodes(sb);
1443 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1444 buf->f_namelen = EXT2_NAME_LEN;
1445 fsid = le64_to_cpup((void *)es->s_uuid) ^
1446 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1447 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1448 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1449 spin_unlock(&sbi->s_lock);
1450 return 0;
1451 }
1452
1453 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1454 int flags, const char *dev_name, void *data)
1455 {
1456 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1457 }
1458
1459 #ifdef CONFIG_QUOTA
1460
1461 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1462 * acquiring the locks... As quota files are never truncated and quota code
1463 * itself serializes the operations (and no one else should touch the files)
1464 * we don't have to be afraid of races */
1465 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1466 size_t len, loff_t off)
1467 {
1468 struct inode *inode = sb_dqopt(sb)->files[type];
1469 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1470 int err = 0;
1471 int offset = off & (sb->s_blocksize - 1);
1472 int tocopy;
1473 size_t toread;
1474 struct buffer_head tmp_bh;
1475 struct buffer_head *bh;
1476 loff_t i_size = i_size_read(inode);
1477
1478 if (off > i_size)
1479 return 0;
1480 if (off+len > i_size)
1481 len = i_size-off;
1482 toread = len;
1483 while (toread > 0) {
1484 tocopy = sb->s_blocksize - offset < toread ?
1485 sb->s_blocksize - offset : toread;
1486
1487 tmp_bh.b_state = 0;
1488 tmp_bh.b_size = sb->s_blocksize;
1489 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1490 if (err < 0)
1491 return err;
1492 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1493 memset(data, 0, tocopy);
1494 else {
1495 bh = sb_bread(sb, tmp_bh.b_blocknr);
1496 if (!bh)
1497 return -EIO;
1498 memcpy(data, bh->b_data+offset, tocopy);
1499 brelse(bh);
1500 }
1501 offset = 0;
1502 toread -= tocopy;
1503 data += tocopy;
1504 blk++;
1505 }
1506 return len;
1507 }
1508
1509 /* Write to quotafile */
1510 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1511 const char *data, size_t len, loff_t off)
1512 {
1513 struct inode *inode = sb_dqopt(sb)->files[type];
1514 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1515 int err = 0;
1516 int offset = off & (sb->s_blocksize - 1);
1517 int tocopy;
1518 size_t towrite = len;
1519 struct buffer_head tmp_bh;
1520 struct buffer_head *bh;
1521
1522 while (towrite > 0) {
1523 tocopy = sb->s_blocksize - offset < towrite ?
1524 sb->s_blocksize - offset : towrite;
1525
1526 tmp_bh.b_state = 0;
1527 tmp_bh.b_size = sb->s_blocksize;
1528 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1529 if (err < 0)
1530 goto out;
1531 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1532 bh = sb_bread(sb, tmp_bh.b_blocknr);
1533 else
1534 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1535 if (unlikely(!bh)) {
1536 err = -EIO;
1537 goto out;
1538 }
1539 lock_buffer(bh);
1540 memcpy(bh->b_data+offset, data, tocopy);
1541 flush_dcache_page(bh->b_page);
1542 set_buffer_uptodate(bh);
1543 mark_buffer_dirty(bh);
1544 unlock_buffer(bh);
1545 brelse(bh);
1546 offset = 0;
1547 towrite -= tocopy;
1548 data += tocopy;
1549 blk++;
1550 }
1551 out:
1552 if (len == towrite)
1553 return err;
1554 if (inode->i_size < off+len-towrite)
1555 i_size_write(inode, off+len-towrite);
1556 inode->i_version++;
1557 inode->i_mtime = inode->i_ctime = current_time(inode);
1558 mark_inode_dirty(inode);
1559 return len - towrite;
1560 }
1561
1562 #endif
1563
1564 static struct file_system_type ext2_fs_type = {
1565 .owner = THIS_MODULE,
1566 .name = "ext2",
1567 .mount = ext2_mount,
1568 .kill_sb = kill_block_super,
1569 .fs_flags = FS_REQUIRES_DEV,
1570 };
1571 MODULE_ALIAS_FS("ext2");
1572
1573 static int __init init_ext2_fs(void)
1574 {
1575 int err;
1576
1577 err = init_inodecache();
1578 if (err)
1579 return err;
1580 err = register_filesystem(&ext2_fs_type);
1581 if (err)
1582 goto out;
1583 return 0;
1584 out:
1585 destroy_inodecache();
1586 return err;
1587 }
1588
1589 static void __exit exit_ext2_fs(void)
1590 {
1591 unregister_filesystem(&ext2_fs_type);
1592 destroy_inodecache();
1593 }
1594
1595 MODULE_AUTHOR("Remy Card and others");
1596 MODULE_DESCRIPTION("Second Extended Filesystem");
1597 MODULE_LICENSE("GPL");
1598 module_init(init_ext2_fs)
1599 module_exit(exit_ext2_fs)
Linux with added FPC-III support