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[people/ms/linux.git] / fs / ext2 / super.c
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 <linux/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 loff_t upper_limit;
728
729 /* This is calculated to be the largest file size for a
730 * dense, file such that the total number of
731 * sectors in the file, including data and all indirect blocks,
732 * does not exceed 2^32 -1
733 * __u32 i_blocks representing the total number of
734 * 512 bytes blocks of the file
735 */
736 upper_limit = (1LL << 32) - 1;
737
738 /* total blocks in file system block size */
739 upper_limit >>= (bits - 9);
740
741
742 /* indirect blocks */
743 meta_blocks = 1;
744 /* double indirect blocks */
745 meta_blocks += 1 + (1LL << (bits-2));
746 /* tripple indirect blocks */
747 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
748
749 upper_limit -= meta_blocks;
750 upper_limit <<= bits;
751
752 res += 1LL << (bits-2);
753 res += 1LL << (2*(bits-2));
754 res += 1LL << (3*(bits-2));
755 res <<= bits;
756 if (res > upper_limit)
757 res = upper_limit;
758
759 if (res > MAX_LFS_FILESIZE)
760 res = MAX_LFS_FILESIZE;
761
762 return res;
763 }
764
765 static unsigned long descriptor_loc(struct super_block *sb,
766 unsigned long logic_sb_block,
767 int nr)
768 {
769 struct ext2_sb_info *sbi = EXT2_SB(sb);
770 unsigned long bg, first_meta_bg;
771 int has_super = 0;
772
773 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
774
775 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
776 nr < first_meta_bg)
777 return (logic_sb_block + nr + 1);
778 bg = sbi->s_desc_per_block * nr;
779 if (ext2_bg_has_super(sb, bg))
780 has_super = 1;
781
782 return ext2_group_first_block_no(sb, bg) + has_super;
783 }
784
785 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
786 {
787 struct buffer_head * bh;
788 struct ext2_sb_info * sbi;
789 struct ext2_super_block * es;
790 struct inode *root;
791 unsigned long block;
792 unsigned long sb_block = get_sb_block(&data);
793 unsigned long logic_sb_block;
794 unsigned long offset = 0;
795 unsigned long def_mount_opts;
796 long ret = -EINVAL;
797 int blocksize = BLOCK_SIZE;
798 int db_count;
799 int i, j;
800 __le32 features;
801 int err;
802
803 err = -ENOMEM;
804 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
805 if (!sbi)
806 goto failed;
807
808 sbi->s_blockgroup_lock =
809 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
810 if (!sbi->s_blockgroup_lock) {
811 kfree(sbi);
812 goto failed;
813 }
814 sb->s_fs_info = sbi;
815 sbi->s_sb_block = sb_block;
816
817 spin_lock_init(&sbi->s_lock);
818
819 /*
820 * See what the current blocksize for the device is, and
821 * use that as the blocksize. Otherwise (or if the blocksize
822 * is smaller than the default) use the default.
823 * This is important for devices that have a hardware
824 * sectorsize that is larger than the default.
825 */
826 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
827 if (!blocksize) {
828 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
829 goto failed_sbi;
830 }
831
832 /*
833 * If the superblock doesn't start on a hardware sector boundary,
834 * calculate the offset.
835 */
836 if (blocksize != BLOCK_SIZE) {
837 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
838 offset = (sb_block*BLOCK_SIZE) % blocksize;
839 } else {
840 logic_sb_block = sb_block;
841 }
842
843 if (!(bh = sb_bread(sb, logic_sb_block))) {
844 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
845 goto failed_sbi;
846 }
847 /*
848 * Note: s_es must be initialized as soon as possible because
849 * some ext2 macro-instructions depend on its value
850 */
851 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
852 sbi->s_es = es;
853 sb->s_magic = le16_to_cpu(es->s_magic);
854
855 if (sb->s_magic != EXT2_SUPER_MAGIC)
856 goto cantfind_ext2;
857
858 /* Set defaults before we parse the mount options */
859 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
860 if (def_mount_opts & EXT2_DEFM_DEBUG)
861 set_opt(sbi->s_mount_opt, DEBUG);
862 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
863 set_opt(sbi->s_mount_opt, GRPID);
864 if (def_mount_opts & EXT2_DEFM_UID16)
865 set_opt(sbi->s_mount_opt, NO_UID32);
866 #ifdef CONFIG_EXT2_FS_XATTR
867 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
868 set_opt(sbi->s_mount_opt, XATTR_USER);
869 #endif
870 #ifdef CONFIG_EXT2_FS_POSIX_ACL
871 if (def_mount_opts & EXT2_DEFM_ACL)
872 set_opt(sbi->s_mount_opt, POSIX_ACL);
873 #endif
874
875 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
876 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
877 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
878 set_opt(sbi->s_mount_opt, ERRORS_CONT);
879 else
880 set_opt(sbi->s_mount_opt, ERRORS_RO);
881
882 sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
883 sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
884
885 set_opt(sbi->s_mount_opt, RESERVATION);
886
887 if (!parse_options((char *) data, sb))
888 goto failed_mount;
889
890 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
891 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
892 MS_POSIXACL : 0);
893 sb->s_iflags |= SB_I_CGROUPWB;
894
895 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
896 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
897 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
898 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
899 ext2_msg(sb, KERN_WARNING,
900 "warning: feature flags set on rev 0 fs, "
901 "running e2fsck is recommended");
902 /*
903 * Check feature flags regardless of the revision level, since we
904 * previously didn't change the revision level when setting the flags,
905 * so there is a chance incompat flags are set on a rev 0 filesystem.
906 */
907 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
908 if (features) {
909 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
910 "unsupported optional features (%x)",
911 le32_to_cpu(features));
912 goto failed_mount;
913 }
914 if (!(sb->s_flags & MS_RDONLY) &&
915 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
916 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
917 "unsupported optional features (%x)",
918 le32_to_cpu(features));
919 goto failed_mount;
920 }
921
922 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
923
924 if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
925 err = bdev_dax_supported(sb, blocksize);
926 if (err)
927 goto failed_mount;
928 }
929
930 /* If the blocksize doesn't match, re-read the thing.. */
931 if (sb->s_blocksize != blocksize) {
932 brelse(bh);
933
934 if (!sb_set_blocksize(sb, blocksize)) {
935 ext2_msg(sb, KERN_ERR,
936 "error: bad blocksize %d", blocksize);
937 goto failed_sbi;
938 }
939
940 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
941 offset = (sb_block*BLOCK_SIZE) % blocksize;
942 bh = sb_bread(sb, logic_sb_block);
943 if(!bh) {
944 ext2_msg(sb, KERN_ERR, "error: couldn't read"
945 "superblock on 2nd try");
946 goto failed_sbi;
947 }
948 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
949 sbi->s_es = es;
950 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
951 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
952 goto failed_mount;
953 }
954 }
955
956 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
957 sb->s_max_links = EXT2_LINK_MAX;
958
959 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
960 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
961 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
962 } else {
963 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
964 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
965 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
966 !is_power_of_2(sbi->s_inode_size) ||
967 (sbi->s_inode_size > blocksize)) {
968 ext2_msg(sb, KERN_ERR,
969 "error: unsupported inode size: %d",
970 sbi->s_inode_size);
971 goto failed_mount;
972 }
973 }
974
975 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
976 le32_to_cpu(es->s_log_frag_size);
977 if (sbi->s_frag_size == 0)
978 goto cantfind_ext2;
979 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
980
981 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
982 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
983 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
984
985 if (EXT2_INODE_SIZE(sb) == 0)
986 goto cantfind_ext2;
987 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
988 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
989 goto cantfind_ext2;
990 sbi->s_itb_per_group = sbi->s_inodes_per_group /
991 sbi->s_inodes_per_block;
992 sbi->s_desc_per_block = sb->s_blocksize /
993 sizeof (struct ext2_group_desc);
994 sbi->s_sbh = bh;
995 sbi->s_mount_state = le16_to_cpu(es->s_state);
996 sbi->s_addr_per_block_bits =
997 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
998 sbi->s_desc_per_block_bits =
999 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1000
1001 if (sb->s_magic != EXT2_SUPER_MAGIC)
1002 goto cantfind_ext2;
1003
1004 if (sb->s_blocksize != bh->b_size) {
1005 if (!silent)
1006 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1007 goto failed_mount;
1008 }
1009
1010 if (sb->s_blocksize != sbi->s_frag_size) {
1011 ext2_msg(sb, KERN_ERR,
1012 "error: fragsize %lu != blocksize %lu"
1013 "(not supported yet)",
1014 sbi->s_frag_size, sb->s_blocksize);
1015 goto failed_mount;
1016 }
1017
1018 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1019 ext2_msg(sb, KERN_ERR,
1020 "error: #blocks per group too big: %lu",
1021 sbi->s_blocks_per_group);
1022 goto failed_mount;
1023 }
1024 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1025 ext2_msg(sb, KERN_ERR,
1026 "error: #fragments per group too big: %lu",
1027 sbi->s_frags_per_group);
1028 goto failed_mount;
1029 }
1030 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1031 ext2_msg(sb, KERN_ERR,
1032 "error: #inodes per group too big: %lu",
1033 sbi->s_inodes_per_group);
1034 goto failed_mount;
1035 }
1036
1037 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1038 goto cantfind_ext2;
1039 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1040 le32_to_cpu(es->s_first_data_block) - 1)
1041 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1042 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1043 EXT2_DESC_PER_BLOCK(sb);
1044 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1045 if (sbi->s_group_desc == NULL) {
1046 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1047 goto failed_mount;
1048 }
1049 bgl_lock_init(sbi->s_blockgroup_lock);
1050 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1051 if (!sbi->s_debts) {
1052 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1053 goto failed_mount_group_desc;
1054 }
1055 for (i = 0; i < db_count; i++) {
1056 block = descriptor_loc(sb, logic_sb_block, i);
1057 sbi->s_group_desc[i] = sb_bread(sb, block);
1058 if (!sbi->s_group_desc[i]) {
1059 for (j = 0; j < i; j++)
1060 brelse (sbi->s_group_desc[j]);
1061 ext2_msg(sb, KERN_ERR,
1062 "error: unable to read group descriptors");
1063 goto failed_mount_group_desc;
1064 }
1065 }
1066 if (!ext2_check_descriptors (sb)) {
1067 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1068 goto failed_mount2;
1069 }
1070 sbi->s_gdb_count = db_count;
1071 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1072 spin_lock_init(&sbi->s_next_gen_lock);
1073
1074 /* per fileystem reservation list head & lock */
1075 spin_lock_init(&sbi->s_rsv_window_lock);
1076 sbi->s_rsv_window_root = RB_ROOT;
1077 /*
1078 * Add a single, static dummy reservation to the start of the
1079 * reservation window list --- it gives us a placeholder for
1080 * append-at-start-of-list which makes the allocation logic
1081 * _much_ simpler.
1082 */
1083 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1084 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1085 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1086 sbi->s_rsv_window_head.rsv_goal_size = 0;
1087 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1088
1089 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1090 ext2_count_free_blocks(sb), GFP_KERNEL);
1091 if (!err) {
1092 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1093 ext2_count_free_inodes(sb), GFP_KERNEL);
1094 }
1095 if (!err) {
1096 err = percpu_counter_init(&sbi->s_dirs_counter,
1097 ext2_count_dirs(sb), GFP_KERNEL);
1098 }
1099 if (err) {
1100 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1101 goto failed_mount3;
1102 }
1103
1104 #ifdef CONFIG_EXT2_FS_XATTR
1105 sbi->s_mb_cache = ext2_xattr_create_cache();
1106 if (!sbi->s_mb_cache) {
1107 ext2_msg(sb, KERN_ERR, "Failed to create an mb_cache");
1108 goto failed_mount3;
1109 }
1110 #endif
1111 /*
1112 * set up enough so that it can read an inode
1113 */
1114 sb->s_op = &ext2_sops;
1115 sb->s_export_op = &ext2_export_ops;
1116 sb->s_xattr = ext2_xattr_handlers;
1117
1118 #ifdef CONFIG_QUOTA
1119 sb->dq_op = &dquot_operations;
1120 sb->s_qcop = &dquot_quotactl_ops;
1121 sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1122 #endif
1123
1124 root = ext2_iget(sb, EXT2_ROOT_INO);
1125 if (IS_ERR(root)) {
1126 ret = PTR_ERR(root);
1127 goto failed_mount3;
1128 }
1129 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1130 iput(root);
1131 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1132 goto failed_mount3;
1133 }
1134
1135 sb->s_root = d_make_root(root);
1136 if (!sb->s_root) {
1137 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1138 ret = -ENOMEM;
1139 goto failed_mount3;
1140 }
1141 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1142 ext2_msg(sb, KERN_WARNING,
1143 "warning: mounting ext3 filesystem as ext2");
1144 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1145 sb->s_flags |= MS_RDONLY;
1146 ext2_write_super(sb);
1147 return 0;
1148
1149 cantfind_ext2:
1150 if (!silent)
1151 ext2_msg(sb, KERN_ERR,
1152 "error: can't find an ext2 filesystem on dev %s.",
1153 sb->s_id);
1154 goto failed_mount;
1155 failed_mount3:
1156 if (sbi->s_mb_cache)
1157 ext2_xattr_destroy_cache(sbi->s_mb_cache);
1158 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1159 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1160 percpu_counter_destroy(&sbi->s_dirs_counter);
1161 failed_mount2:
1162 for (i = 0; i < db_count; i++)
1163 brelse(sbi->s_group_desc[i]);
1164 failed_mount_group_desc:
1165 kfree(sbi->s_group_desc);
1166 kfree(sbi->s_debts);
1167 failed_mount:
1168 brelse(bh);
1169 failed_sbi:
1170 sb->s_fs_info = NULL;
1171 kfree(sbi->s_blockgroup_lock);
1172 kfree(sbi);
1173 failed:
1174 return ret;
1175 }
1176
1177 static void ext2_clear_super_error(struct super_block *sb)
1178 {
1179 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1180
1181 if (buffer_write_io_error(sbh)) {
1182 /*
1183 * Oh, dear. A previous attempt to write the
1184 * superblock failed. This could happen because the
1185 * USB device was yanked out. Or it could happen to
1186 * be a transient write error and maybe the block will
1187 * be remapped. Nothing we can do but to retry the
1188 * write and hope for the best.
1189 */
1190 ext2_msg(sb, KERN_ERR,
1191 "previous I/O error to superblock detected\n");
1192 clear_buffer_write_io_error(sbh);
1193 set_buffer_uptodate(sbh);
1194 }
1195 }
1196
1197 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1198 int wait)
1199 {
1200 ext2_clear_super_error(sb);
1201 spin_lock(&EXT2_SB(sb)->s_lock);
1202 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1203 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1204 es->s_wtime = cpu_to_le32(get_seconds());
1205 /* unlock before we do IO */
1206 spin_unlock(&EXT2_SB(sb)->s_lock);
1207 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1208 if (wait)
1209 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1210 }
1211
1212 /*
1213 * In the second extended file system, it is not necessary to
1214 * write the super block since we use a mapping of the
1215 * disk super block in a buffer.
1216 *
1217 * However, this function is still used to set the fs valid
1218 * flags to 0. We need to set this flag to 0 since the fs
1219 * may have been checked while mounted and e2fsck may have
1220 * set s_state to EXT2_VALID_FS after some corrections.
1221 */
1222 static int ext2_sync_fs(struct super_block *sb, int wait)
1223 {
1224 struct ext2_sb_info *sbi = EXT2_SB(sb);
1225 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1226
1227 /*
1228 * Write quota structures to quota file, sync_blockdev() will write
1229 * them to disk later
1230 */
1231 dquot_writeback_dquots(sb, -1);
1232
1233 spin_lock(&sbi->s_lock);
1234 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1235 ext2_debug("setting valid to 0\n");
1236 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1237 }
1238 spin_unlock(&sbi->s_lock);
1239 ext2_sync_super(sb, es, wait);
1240 return 0;
1241 }
1242
1243 static int ext2_freeze(struct super_block *sb)
1244 {
1245 struct ext2_sb_info *sbi = EXT2_SB(sb);
1246
1247 /*
1248 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1249 * because we have unattached inodes and thus filesystem is not fully
1250 * consistent.
1251 */
1252 if (atomic_long_read(&sb->s_remove_count)) {
1253 ext2_sync_fs(sb, 1);
1254 return 0;
1255 }
1256 /* Set EXT2_FS_VALID flag */
1257 spin_lock(&sbi->s_lock);
1258 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1259 spin_unlock(&sbi->s_lock);
1260 ext2_sync_super(sb, sbi->s_es, 1);
1261
1262 return 0;
1263 }
1264
1265 static int ext2_unfreeze(struct super_block *sb)
1266 {
1267 /* Just write sb to clear EXT2_VALID_FS flag */
1268 ext2_write_super(sb);
1269
1270 return 0;
1271 }
1272
1273 void ext2_write_super(struct super_block *sb)
1274 {
1275 if (!(sb->s_flags & MS_RDONLY))
1276 ext2_sync_fs(sb, 1);
1277 }
1278
1279 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1280 {
1281 struct ext2_sb_info * sbi = EXT2_SB(sb);
1282 struct ext2_super_block * es;
1283 struct ext2_mount_options old_opts;
1284 unsigned long old_sb_flags;
1285 int err;
1286
1287 sync_filesystem(sb);
1288 spin_lock(&sbi->s_lock);
1289
1290 /* Store the old options */
1291 old_sb_flags = sb->s_flags;
1292 old_opts.s_mount_opt = sbi->s_mount_opt;
1293 old_opts.s_resuid = sbi->s_resuid;
1294 old_opts.s_resgid = sbi->s_resgid;
1295
1296 /*
1297 * Allow the "check" option to be passed as a remount option.
1298 */
1299 if (!parse_options(data, sb)) {
1300 err = -EINVAL;
1301 goto restore_opts;
1302 }
1303
1304 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1305 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1306
1307 es = sbi->s_es;
1308 if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1309 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1310 "dax flag with busy inodes while remounting");
1311 sbi->s_mount_opt ^= EXT2_MOUNT_DAX;
1312 }
1313 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1314 spin_unlock(&sbi->s_lock);
1315 return 0;
1316 }
1317 if (*flags & MS_RDONLY) {
1318 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1319 !(sbi->s_mount_state & EXT2_VALID_FS)) {
1320 spin_unlock(&sbi->s_lock);
1321 return 0;
1322 }
1323
1324 /*
1325 * OK, we are remounting a valid rw partition rdonly, so set
1326 * the rdonly flag and then mark the partition as valid again.
1327 */
1328 es->s_state = cpu_to_le16(sbi->s_mount_state);
1329 es->s_mtime = cpu_to_le32(get_seconds());
1330 spin_unlock(&sbi->s_lock);
1331
1332 err = dquot_suspend(sb, -1);
1333 if (err < 0) {
1334 spin_lock(&sbi->s_lock);
1335 goto restore_opts;
1336 }
1337
1338 ext2_sync_super(sb, es, 1);
1339 } else {
1340 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1341 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1342 if (ret) {
1343 ext2_msg(sb, KERN_WARNING,
1344 "warning: couldn't remount RDWR because of "
1345 "unsupported optional features (%x).",
1346 le32_to_cpu(ret));
1347 err = -EROFS;
1348 goto restore_opts;
1349 }
1350 /*
1351 * Mounting a RDONLY partition read-write, so reread and
1352 * store the current valid flag. (It may have been changed
1353 * by e2fsck since we originally mounted the partition.)
1354 */
1355 sbi->s_mount_state = le16_to_cpu(es->s_state);
1356 if (!ext2_setup_super (sb, es, 0))
1357 sb->s_flags &= ~MS_RDONLY;
1358 spin_unlock(&sbi->s_lock);
1359
1360 ext2_write_super(sb);
1361
1362 dquot_resume(sb, -1);
1363 }
1364
1365 return 0;
1366 restore_opts:
1367 sbi->s_mount_opt = old_opts.s_mount_opt;
1368 sbi->s_resuid = old_opts.s_resuid;
1369 sbi->s_resgid = old_opts.s_resgid;
1370 sb->s_flags = old_sb_flags;
1371 spin_unlock(&sbi->s_lock);
1372 return err;
1373 }
1374
1375 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1376 {
1377 struct super_block *sb = dentry->d_sb;
1378 struct ext2_sb_info *sbi = EXT2_SB(sb);
1379 struct ext2_super_block *es = sbi->s_es;
1380 u64 fsid;
1381
1382 spin_lock(&sbi->s_lock);
1383
1384 if (test_opt (sb, MINIX_DF))
1385 sbi->s_overhead_last = 0;
1386 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1387 unsigned long i, overhead = 0;
1388 smp_rmb();
1389
1390 /*
1391 * Compute the overhead (FS structures). This is constant
1392 * for a given filesystem unless the number of block groups
1393 * changes so we cache the previous value until it does.
1394 */
1395
1396 /*
1397 * All of the blocks before first_data_block are
1398 * overhead
1399 */
1400 overhead = le32_to_cpu(es->s_first_data_block);
1401
1402 /*
1403 * Add the overhead attributed to the superblock and
1404 * block group descriptors. If the sparse superblocks
1405 * feature is turned on, then not all groups have this.
1406 */
1407 for (i = 0; i < sbi->s_groups_count; i++)
1408 overhead += ext2_bg_has_super(sb, i) +
1409 ext2_bg_num_gdb(sb, i);
1410
1411 /*
1412 * Every block group has an inode bitmap, a block
1413 * bitmap, and an inode table.
1414 */
1415 overhead += (sbi->s_groups_count *
1416 (2 + sbi->s_itb_per_group));
1417 sbi->s_overhead_last = overhead;
1418 smp_wmb();
1419 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1420 }
1421
1422 buf->f_type = EXT2_SUPER_MAGIC;
1423 buf->f_bsize = sb->s_blocksize;
1424 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1425 buf->f_bfree = ext2_count_free_blocks(sb);
1426 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1427 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1428 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1429 buf->f_bavail = 0;
1430 buf->f_files = le32_to_cpu(es->s_inodes_count);
1431 buf->f_ffree = ext2_count_free_inodes(sb);
1432 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1433 buf->f_namelen = EXT2_NAME_LEN;
1434 fsid = le64_to_cpup((void *)es->s_uuid) ^
1435 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1436 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1437 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1438 spin_unlock(&sbi->s_lock);
1439 return 0;
1440 }
1441
1442 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1443 int flags, const char *dev_name, void *data)
1444 {
1445 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1446 }
1447
1448 #ifdef CONFIG_QUOTA
1449
1450 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1451 * acquiring the locks... As quota files are never truncated and quota code
1452 * itself serializes the operations (and no one else should touch the files)
1453 * we don't have to be afraid of races */
1454 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1455 size_t len, loff_t off)
1456 {
1457 struct inode *inode = sb_dqopt(sb)->files[type];
1458 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1459 int err = 0;
1460 int offset = off & (sb->s_blocksize - 1);
1461 int tocopy;
1462 size_t toread;
1463 struct buffer_head tmp_bh;
1464 struct buffer_head *bh;
1465 loff_t i_size = i_size_read(inode);
1466
1467 if (off > i_size)
1468 return 0;
1469 if (off+len > i_size)
1470 len = i_size-off;
1471 toread = len;
1472 while (toread > 0) {
1473 tocopy = sb->s_blocksize - offset < toread ?
1474 sb->s_blocksize - offset : toread;
1475
1476 tmp_bh.b_state = 0;
1477 tmp_bh.b_size = sb->s_blocksize;
1478 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1479 if (err < 0)
1480 return err;
1481 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1482 memset(data, 0, tocopy);
1483 else {
1484 bh = sb_bread(sb, tmp_bh.b_blocknr);
1485 if (!bh)
1486 return -EIO;
1487 memcpy(data, bh->b_data+offset, tocopy);
1488 brelse(bh);
1489 }
1490 offset = 0;
1491 toread -= tocopy;
1492 data += tocopy;
1493 blk++;
1494 }
1495 return len;
1496 }
1497
1498 /* Write to quotafile */
1499 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1500 const char *data, size_t len, loff_t off)
1501 {
1502 struct inode *inode = sb_dqopt(sb)->files[type];
1503 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1504 int err = 0;
1505 int offset = off & (sb->s_blocksize - 1);
1506 int tocopy;
1507 size_t towrite = len;
1508 struct buffer_head tmp_bh;
1509 struct buffer_head *bh;
1510
1511 while (towrite > 0) {
1512 tocopy = sb->s_blocksize - offset < towrite ?
1513 sb->s_blocksize - offset : towrite;
1514
1515 tmp_bh.b_state = 0;
1516 tmp_bh.b_size = sb->s_blocksize;
1517 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1518 if (err < 0)
1519 goto out;
1520 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1521 bh = sb_bread(sb, tmp_bh.b_blocknr);
1522 else
1523 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1524 if (unlikely(!bh)) {
1525 err = -EIO;
1526 goto out;
1527 }
1528 lock_buffer(bh);
1529 memcpy(bh->b_data+offset, data, tocopy);
1530 flush_dcache_page(bh->b_page);
1531 set_buffer_uptodate(bh);
1532 mark_buffer_dirty(bh);
1533 unlock_buffer(bh);
1534 brelse(bh);
1535 offset = 0;
1536 towrite -= tocopy;
1537 data += tocopy;
1538 blk++;
1539 }
1540 out:
1541 if (len == towrite)
1542 return err;
1543 if (inode->i_size < off+len-towrite)
1544 i_size_write(inode, off+len-towrite);
1545 inode->i_version++;
1546 inode->i_mtime = inode->i_ctime = current_time(inode);
1547 mark_inode_dirty(inode);
1548 return len - towrite;
1549 }
1550
1551 #endif
1552
1553 static struct file_system_type ext2_fs_type = {
1554 .owner = THIS_MODULE,
1555 .name = "ext2",
1556 .mount = ext2_mount,
1557 .kill_sb = kill_block_super,
1558 .fs_flags = FS_REQUIRES_DEV,
1559 };
1560 MODULE_ALIAS_FS("ext2");
1561
1562 static int __init init_ext2_fs(void)
1563 {
1564 int err;
1565
1566 err = init_inodecache();
1567 if (err)
1568 return err;
1569 err = register_filesystem(&ext2_fs_type);
1570 if (err)
1571 goto out;
1572 return 0;
1573 out:
1574 destroy_inodecache();
1575 return err;
1576 }
1577
1578 static void __exit exit_ext2_fs(void)
1579 {
1580 unregister_filesystem(&ext2_fs_type);
1581 destroy_inodecache();
1582 }
1583
1584 MODULE_AUTHOR("Remy Card and others");
1585 MODULE_DESCRIPTION("Second Extended Filesystem");
1586 MODULE_LICENSE("GPL");
1587 module_init(init_ext2_fs)
1588 module_exit(exit_ext2_fs)
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