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Merge branch 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...
[deliverable/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 <asm/uaccess.h>
35 #include "ext2.h"
36 #include "xattr.h"
37 #include "acl.h"
38
39 static void ext2_sync_super(struct super_block *sb,
40 struct ext2_super_block *es, int wait);
41 static int ext2_remount (struct super_block * sb, int * flags, char * data);
42 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
43 static int ext2_sync_fs(struct super_block *sb, int wait);
44 static int ext2_freeze(struct super_block *sb);
45 static int ext2_unfreeze(struct super_block *sb);
46
47 void ext2_error(struct super_block *sb, const char *function,
48 const char *fmt, ...)
49 {
50 struct va_format vaf;
51 va_list args;
52 struct ext2_sb_info *sbi = EXT2_SB(sb);
53 struct ext2_super_block *es = sbi->s_es;
54
55 if (!(sb->s_flags & MS_RDONLY)) {
56 spin_lock(&sbi->s_lock);
57 sbi->s_mount_state |= EXT2_ERROR_FS;
58 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
59 spin_unlock(&sbi->s_lock);
60 ext2_sync_super(sb, es, 1);
61 }
62
63 va_start(args, fmt);
64
65 vaf.fmt = fmt;
66 vaf.va = &args;
67
68 printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
69 sb->s_id, function, &vaf);
70
71 va_end(args);
72
73 if (test_opt(sb, ERRORS_PANIC))
74 panic("EXT2-fs: panic from previous error\n");
75 if (test_opt(sb, ERRORS_RO)) {
76 ext2_msg(sb, KERN_CRIT,
77 "error: remounting filesystem read-only");
78 sb->s_flags |= MS_RDONLY;
79 }
80 }
81
82 void ext2_msg(struct super_block *sb, const char *prefix,
83 const char *fmt, ...)
84 {
85 struct va_format vaf;
86 va_list args;
87
88 va_start(args, fmt);
89
90 vaf.fmt = fmt;
91 vaf.va = &args;
92
93 printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
94
95 va_end(args);
96 }
97
98 /*
99 * This must be called with sbi->s_lock held.
100 */
101 void ext2_update_dynamic_rev(struct super_block *sb)
102 {
103 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
104
105 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
106 return;
107
108 ext2_msg(sb, KERN_WARNING,
109 "warning: updating to rev %d because of "
110 "new feature flag, running e2fsck is recommended",
111 EXT2_DYNAMIC_REV);
112
113 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
114 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
115 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
116 /* leave es->s_feature_*compat flags alone */
117 /* es->s_uuid will be set by e2fsck if empty */
118
119 /*
120 * The rest of the superblock fields should be zero, and if not it
121 * means they are likely already in use, so leave them alone. We
122 * can leave it up to e2fsck to clean up any inconsistencies there.
123 */
124 }
125
126 static void ext2_put_super (struct super_block * sb)
127 {
128 int db_count;
129 int i;
130 struct ext2_sb_info *sbi = EXT2_SB(sb);
131
132 dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
133
134 ext2_xattr_put_super(sb);
135 if (!(sb->s_flags & MS_RDONLY)) {
136 struct ext2_super_block *es = sbi->s_es;
137
138 spin_lock(&sbi->s_lock);
139 es->s_state = cpu_to_le16(sbi->s_mount_state);
140 spin_unlock(&sbi->s_lock);
141 ext2_sync_super(sb, es, 1);
142 }
143 db_count = sbi->s_gdb_count;
144 for (i = 0; i < db_count; i++)
145 if (sbi->s_group_desc[i])
146 brelse (sbi->s_group_desc[i]);
147 kfree(sbi->s_group_desc);
148 kfree(sbi->s_debts);
149 percpu_counter_destroy(&sbi->s_freeblocks_counter);
150 percpu_counter_destroy(&sbi->s_freeinodes_counter);
151 percpu_counter_destroy(&sbi->s_dirs_counter);
152 brelse (sbi->s_sbh);
153 sb->s_fs_info = NULL;
154 kfree(sbi->s_blockgroup_lock);
155 kfree(sbi);
156 }
157
158 static struct kmem_cache * ext2_inode_cachep;
159
160 static struct inode *ext2_alloc_inode(struct super_block *sb)
161 {
162 struct ext2_inode_info *ei;
163 ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
164 if (!ei)
165 return NULL;
166 ei->i_block_alloc_info = NULL;
167 ei->vfs_inode.i_version = 1;
168 #ifdef CONFIG_QUOTA
169 memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
170 #endif
171
172 return &ei->vfs_inode;
173 }
174
175 static void ext2_i_callback(struct rcu_head *head)
176 {
177 struct inode *inode = container_of(head, struct inode, i_rcu);
178 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
179 }
180
181 static void ext2_destroy_inode(struct inode *inode)
182 {
183 call_rcu(&inode->i_rcu, ext2_i_callback);
184 }
185
186 static void init_once(void *foo)
187 {
188 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
189
190 rwlock_init(&ei->i_meta_lock);
191 #ifdef CONFIG_EXT2_FS_XATTR
192 init_rwsem(&ei->xattr_sem);
193 #endif
194 mutex_init(&ei->truncate_mutex);
195 inode_init_once(&ei->vfs_inode);
196 }
197
198 static int __init init_inodecache(void)
199 {
200 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
201 sizeof(struct ext2_inode_info),
202 0, (SLAB_RECLAIM_ACCOUNT|
203 SLAB_MEM_SPREAD),
204 init_once);
205 if (ext2_inode_cachep == NULL)
206 return -ENOMEM;
207 return 0;
208 }
209
210 static void destroy_inodecache(void)
211 {
212 /*
213 * Make sure all delayed rcu free inodes are flushed before we
214 * destroy cache.
215 */
216 rcu_barrier();
217 kmem_cache_destroy(ext2_inode_cachep);
218 }
219
220 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
221 {
222 struct super_block *sb = root->d_sb;
223 struct ext2_sb_info *sbi = EXT2_SB(sb);
224 struct ext2_super_block *es = sbi->s_es;
225 unsigned long def_mount_opts;
226
227 spin_lock(&sbi->s_lock);
228 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
229
230 if (sbi->s_sb_block != 1)
231 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
232 if (test_opt(sb, MINIX_DF))
233 seq_puts(seq, ",minixdf");
234 if (test_opt(sb, GRPID))
235 seq_puts(seq, ",grpid");
236 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
237 seq_puts(seq, ",nogrpid");
238 if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
239 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
240 seq_printf(seq, ",resuid=%u",
241 from_kuid_munged(&init_user_ns, sbi->s_resuid));
242 }
243 if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
244 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
245 seq_printf(seq, ",resgid=%u",
246 from_kgid_munged(&init_user_ns, sbi->s_resgid));
247 }
248 if (test_opt(sb, ERRORS_RO)) {
249 int def_errors = le16_to_cpu(es->s_errors);
250
251 if (def_errors == EXT2_ERRORS_PANIC ||
252 def_errors == EXT2_ERRORS_CONTINUE) {
253 seq_puts(seq, ",errors=remount-ro");
254 }
255 }
256 if (test_opt(sb, ERRORS_CONT))
257 seq_puts(seq, ",errors=continue");
258 if (test_opt(sb, ERRORS_PANIC))
259 seq_puts(seq, ",errors=panic");
260 if (test_opt(sb, NO_UID32))
261 seq_puts(seq, ",nouid32");
262 if (test_opt(sb, DEBUG))
263 seq_puts(seq, ",debug");
264 if (test_opt(sb, OLDALLOC))
265 seq_puts(seq, ",oldalloc");
266
267 #ifdef CONFIG_EXT2_FS_XATTR
268 if (test_opt(sb, XATTR_USER))
269 seq_puts(seq, ",user_xattr");
270 if (!test_opt(sb, XATTR_USER) &&
271 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
272 seq_puts(seq, ",nouser_xattr");
273 }
274 #endif
275
276 #ifdef CONFIG_EXT2_FS_POSIX_ACL
277 if (test_opt(sb, POSIX_ACL))
278 seq_puts(seq, ",acl");
279 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
280 seq_puts(seq, ",noacl");
281 #endif
282
283 if (test_opt(sb, NOBH))
284 seq_puts(seq, ",nobh");
285
286 #if defined(CONFIG_QUOTA)
287 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
288 seq_puts(seq, ",usrquota");
289
290 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
291 seq_puts(seq, ",grpquota");
292 #endif
293
294 #ifdef CONFIG_FS_DAX
295 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
296 seq_puts(seq, ",xip");
297 if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
298 seq_puts(seq, ",dax");
299 #endif
300
301 if (!test_opt(sb, RESERVATION))
302 seq_puts(seq, ",noreservation");
303
304 spin_unlock(&sbi->s_lock);
305 return 0;
306 }
307
308 #ifdef CONFIG_QUOTA
309 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
310 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
311 static struct dquot **ext2_get_dquots(struct inode *inode)
312 {
313 return EXT2_I(inode)->i_dquot;
314 }
315 #endif
316
317 static const struct super_operations ext2_sops = {
318 .alloc_inode = ext2_alloc_inode,
319 .destroy_inode = ext2_destroy_inode,
320 .write_inode = ext2_write_inode,
321 .evict_inode = ext2_evict_inode,
322 .put_super = ext2_put_super,
323 .sync_fs = ext2_sync_fs,
324 .freeze_fs = ext2_freeze,
325 .unfreeze_fs = ext2_unfreeze,
326 .statfs = ext2_statfs,
327 .remount_fs = ext2_remount,
328 .show_options = ext2_show_options,
329 #ifdef CONFIG_QUOTA
330 .quota_read = ext2_quota_read,
331 .quota_write = ext2_quota_write,
332 .get_dquots = ext2_get_dquots,
333 #endif
334 };
335
336 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
337 u64 ino, u32 generation)
338 {
339 struct inode *inode;
340
341 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
342 return ERR_PTR(-ESTALE);
343 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
344 return ERR_PTR(-ESTALE);
345
346 /*
347 * ext2_iget isn't quite right if the inode is currently unallocated!
348 * However ext2_iget currently does appropriate checks to handle stale
349 * inodes so everything is OK.
350 */
351 inode = ext2_iget(sb, ino);
352 if (IS_ERR(inode))
353 return ERR_CAST(inode);
354 if (generation && inode->i_generation != generation) {
355 /* we didn't find the right inode.. */
356 iput(inode);
357 return ERR_PTR(-ESTALE);
358 }
359 return inode;
360 }
361
362 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
363 int fh_len, int fh_type)
364 {
365 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
366 ext2_nfs_get_inode);
367 }
368
369 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
370 int fh_len, int fh_type)
371 {
372 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
373 ext2_nfs_get_inode);
374 }
375
376 static const struct export_operations ext2_export_ops = {
377 .fh_to_dentry = ext2_fh_to_dentry,
378 .fh_to_parent = ext2_fh_to_parent,
379 .get_parent = ext2_get_parent,
380 };
381
382 static unsigned long get_sb_block(void **data)
383 {
384 unsigned long sb_block;
385 char *options = (char *) *data;
386
387 if (!options || strncmp(options, "sb=", 3) != 0)
388 return 1; /* Default location */
389 options += 3;
390 sb_block = simple_strtoul(options, &options, 0);
391 if (*options && *options != ',') {
392 printk("EXT2-fs: Invalid sb specification: %s\n",
393 (char *) *data);
394 return 1;
395 }
396 if (*options == ',')
397 options++;
398 *data = (void *) options;
399 return sb_block;
400 }
401
402 enum {
403 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
404 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
405 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
406 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
407 Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
408 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
409 };
410
411 static const match_table_t tokens = {
412 {Opt_bsd_df, "bsddf"},
413 {Opt_minix_df, "minixdf"},
414 {Opt_grpid, "grpid"},
415 {Opt_grpid, "bsdgroups"},
416 {Opt_nogrpid, "nogrpid"},
417 {Opt_nogrpid, "sysvgroups"},
418 {Opt_resgid, "resgid=%u"},
419 {Opt_resuid, "resuid=%u"},
420 {Opt_sb, "sb=%u"},
421 {Opt_err_cont, "errors=continue"},
422 {Opt_err_panic, "errors=panic"},
423 {Opt_err_ro, "errors=remount-ro"},
424 {Opt_nouid32, "nouid32"},
425 {Opt_nocheck, "check=none"},
426 {Opt_nocheck, "nocheck"},
427 {Opt_debug, "debug"},
428 {Opt_oldalloc, "oldalloc"},
429 {Opt_orlov, "orlov"},
430 {Opt_nobh, "nobh"},
431 {Opt_user_xattr, "user_xattr"},
432 {Opt_nouser_xattr, "nouser_xattr"},
433 {Opt_acl, "acl"},
434 {Opt_noacl, "noacl"},
435 {Opt_xip, "xip"},
436 {Opt_dax, "dax"},
437 {Opt_grpquota, "grpquota"},
438 {Opt_ignore, "noquota"},
439 {Opt_quota, "quota"},
440 {Opt_usrquota, "usrquota"},
441 {Opt_reservation, "reservation"},
442 {Opt_noreservation, "noreservation"},
443 {Opt_err, NULL}
444 };
445
446 static int parse_options(char *options, struct super_block *sb)
447 {
448 char *p;
449 struct ext2_sb_info *sbi = EXT2_SB(sb);
450 substring_t args[MAX_OPT_ARGS];
451 int option;
452 kuid_t uid;
453 kgid_t gid;
454
455 if (!options)
456 return 1;
457
458 while ((p = strsep (&options, ",")) != NULL) {
459 int token;
460 if (!*p)
461 continue;
462
463 token = match_token(p, tokens, args);
464 switch (token) {
465 case Opt_bsd_df:
466 clear_opt (sbi->s_mount_opt, MINIX_DF);
467 break;
468 case Opt_minix_df:
469 set_opt (sbi->s_mount_opt, MINIX_DF);
470 break;
471 case Opt_grpid:
472 set_opt (sbi->s_mount_opt, GRPID);
473 break;
474 case Opt_nogrpid:
475 clear_opt (sbi->s_mount_opt, GRPID);
476 break;
477 case Opt_resuid:
478 if (match_int(&args[0], &option))
479 return 0;
480 uid = make_kuid(current_user_ns(), option);
481 if (!uid_valid(uid)) {
482 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
483 return 0;
484
485 }
486 sbi->s_resuid = uid;
487 break;
488 case Opt_resgid:
489 if (match_int(&args[0], &option))
490 return 0;
491 gid = make_kgid(current_user_ns(), option);
492 if (!gid_valid(gid)) {
493 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
494 return 0;
495 }
496 sbi->s_resgid = gid;
497 break;
498 case Opt_sb:
499 /* handled by get_sb_block() instead of here */
500 /* *sb_block = match_int(&args[0]); */
501 break;
502 case Opt_err_panic:
503 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
504 clear_opt (sbi->s_mount_opt, ERRORS_RO);
505 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
506 break;
507 case Opt_err_ro:
508 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
509 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
510 set_opt (sbi->s_mount_opt, ERRORS_RO);
511 break;
512 case Opt_err_cont:
513 clear_opt (sbi->s_mount_opt, ERRORS_RO);
514 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
515 set_opt (sbi->s_mount_opt, ERRORS_CONT);
516 break;
517 case Opt_nouid32:
518 set_opt (sbi->s_mount_opt, NO_UID32);
519 break;
520 case Opt_nocheck:
521 clear_opt (sbi->s_mount_opt, CHECK);
522 break;
523 case Opt_debug:
524 set_opt (sbi->s_mount_opt, DEBUG);
525 break;
526 case Opt_oldalloc:
527 set_opt (sbi->s_mount_opt, OLDALLOC);
528 break;
529 case Opt_orlov:
530 clear_opt (sbi->s_mount_opt, OLDALLOC);
531 break;
532 case Opt_nobh:
533 set_opt (sbi->s_mount_opt, NOBH);
534 break;
535 #ifdef CONFIG_EXT2_FS_XATTR
536 case Opt_user_xattr:
537 set_opt (sbi->s_mount_opt, XATTR_USER);
538 break;
539 case Opt_nouser_xattr:
540 clear_opt (sbi->s_mount_opt, XATTR_USER);
541 break;
542 #else
543 case Opt_user_xattr:
544 case Opt_nouser_xattr:
545 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
546 "not supported");
547 break;
548 #endif
549 #ifdef CONFIG_EXT2_FS_POSIX_ACL
550 case Opt_acl:
551 set_opt(sbi->s_mount_opt, POSIX_ACL);
552 break;
553 case Opt_noacl:
554 clear_opt(sbi->s_mount_opt, POSIX_ACL);
555 break;
556 #else
557 case Opt_acl:
558 case Opt_noacl:
559 ext2_msg(sb, KERN_INFO,
560 "(no)acl options not supported");
561 break;
562 #endif
563 case Opt_xip:
564 ext2_msg(sb, KERN_INFO, "use dax instead of xip");
565 set_opt(sbi->s_mount_opt, XIP);
566 /* Fall through */
567 case Opt_dax:
568 #ifdef CONFIG_FS_DAX
569 set_opt(sbi->s_mount_opt, DAX);
570 #else
571 ext2_msg(sb, KERN_INFO, "dax option not supported");
572 #endif
573 break;
574
575 #if defined(CONFIG_QUOTA)
576 case Opt_quota:
577 case Opt_usrquota:
578 set_opt(sbi->s_mount_opt, USRQUOTA);
579 break;
580
581 case Opt_grpquota:
582 set_opt(sbi->s_mount_opt, GRPQUOTA);
583 break;
584 #else
585 case Opt_quota:
586 case Opt_usrquota:
587 case Opt_grpquota:
588 ext2_msg(sb, KERN_INFO,
589 "quota operations not supported");
590 break;
591 #endif
592
593 case Opt_reservation:
594 set_opt(sbi->s_mount_opt, RESERVATION);
595 ext2_msg(sb, KERN_INFO, "reservations ON");
596 break;
597 case Opt_noreservation:
598 clear_opt(sbi->s_mount_opt, RESERVATION);
599 ext2_msg(sb, KERN_INFO, "reservations OFF");
600 break;
601 case Opt_ignore:
602 break;
603 default:
604 return 0;
605 }
606 }
607 return 1;
608 }
609
610 static int ext2_setup_super (struct super_block * sb,
611 struct ext2_super_block * es,
612 int read_only)
613 {
614 int res = 0;
615 struct ext2_sb_info *sbi = EXT2_SB(sb);
616
617 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
618 ext2_msg(sb, KERN_ERR,
619 "error: revision level too high, "
620 "forcing read-only mode");
621 res = MS_RDONLY;
622 }
623 if (read_only)
624 return res;
625 if (!(sbi->s_mount_state & EXT2_VALID_FS))
626 ext2_msg(sb, KERN_WARNING,
627 "warning: mounting unchecked fs, "
628 "running e2fsck is recommended");
629 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
630 ext2_msg(sb, KERN_WARNING,
631 "warning: mounting fs with errors, "
632 "running e2fsck is recommended");
633 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
634 le16_to_cpu(es->s_mnt_count) >=
635 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
636 ext2_msg(sb, KERN_WARNING,
637 "warning: maximal mount count reached, "
638 "running e2fsck is recommended");
639 else if (le32_to_cpu(es->s_checkinterval) &&
640 (le32_to_cpu(es->s_lastcheck) +
641 le32_to_cpu(es->s_checkinterval) <= get_seconds()))
642 ext2_msg(sb, KERN_WARNING,
643 "warning: checktime reached, "
644 "running e2fsck is recommended");
645 if (!le16_to_cpu(es->s_max_mnt_count))
646 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
647 le16_add_cpu(&es->s_mnt_count, 1);
648 if (test_opt (sb, DEBUG))
649 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
650 "bpg=%lu, ipg=%lu, mo=%04lx]",
651 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
652 sbi->s_frag_size,
653 sbi->s_groups_count,
654 EXT2_BLOCKS_PER_GROUP(sb),
655 EXT2_INODES_PER_GROUP(sb),
656 sbi->s_mount_opt);
657 return res;
658 }
659
660 static int ext2_check_descriptors(struct super_block *sb)
661 {
662 int i;
663 struct ext2_sb_info *sbi = EXT2_SB(sb);
664
665 ext2_debug ("Checking group descriptors");
666
667 for (i = 0; i < sbi->s_groups_count; i++) {
668 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
669 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
670 ext2_fsblk_t last_block;
671
672 if (i == sbi->s_groups_count - 1)
673 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
674 else
675 last_block = first_block +
676 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
677
678 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
679 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
680 {
681 ext2_error (sb, "ext2_check_descriptors",
682 "Block bitmap for group %d"
683 " not in group (block %lu)!",
684 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
685 return 0;
686 }
687 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
688 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
689 {
690 ext2_error (sb, "ext2_check_descriptors",
691 "Inode bitmap for group %d"
692 " not in group (block %lu)!",
693 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
694 return 0;
695 }
696 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
697 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
698 last_block)
699 {
700 ext2_error (sb, "ext2_check_descriptors",
701 "Inode table for group %d"
702 " not in group (block %lu)!",
703 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
704 return 0;
705 }
706 }
707 return 1;
708 }
709
710 /*
711 * Maximal file size. There is a direct, and {,double-,triple-}indirect
712 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
713 * We need to be 1 filesystem block less than the 2^32 sector limit.
714 */
715 static loff_t ext2_max_size(int bits)
716 {
717 loff_t res = EXT2_NDIR_BLOCKS;
718 int meta_blocks;
719 loff_t upper_limit;
720
721 /* This is calculated to be the largest file size for a
722 * dense, file such that the total number of
723 * sectors in the file, including data and all indirect blocks,
724 * does not exceed 2^32 -1
725 * __u32 i_blocks representing the total number of
726 * 512 bytes blocks of the file
727 */
728 upper_limit = (1LL << 32) - 1;
729
730 /* total blocks in file system block size */
731 upper_limit >>= (bits - 9);
732
733
734 /* indirect blocks */
735 meta_blocks = 1;
736 /* double indirect blocks */
737 meta_blocks += 1 + (1LL << (bits-2));
738 /* tripple indirect blocks */
739 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
740
741 upper_limit -= meta_blocks;
742 upper_limit <<= bits;
743
744 res += 1LL << (bits-2);
745 res += 1LL << (2*(bits-2));
746 res += 1LL << (3*(bits-2));
747 res <<= bits;
748 if (res > upper_limit)
749 res = upper_limit;
750
751 if (res > MAX_LFS_FILESIZE)
752 res = MAX_LFS_FILESIZE;
753
754 return res;
755 }
756
757 static unsigned long descriptor_loc(struct super_block *sb,
758 unsigned long logic_sb_block,
759 int nr)
760 {
761 struct ext2_sb_info *sbi = EXT2_SB(sb);
762 unsigned long bg, first_meta_bg;
763 int has_super = 0;
764
765 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
766
767 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
768 nr < first_meta_bg)
769 return (logic_sb_block + nr + 1);
770 bg = sbi->s_desc_per_block * nr;
771 if (ext2_bg_has_super(sb, bg))
772 has_super = 1;
773
774 return ext2_group_first_block_no(sb, bg) + has_super;
775 }
776
777 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
778 {
779 struct buffer_head * bh;
780 struct ext2_sb_info * sbi;
781 struct ext2_super_block * es;
782 struct inode *root;
783 unsigned long block;
784 unsigned long sb_block = get_sb_block(&data);
785 unsigned long logic_sb_block;
786 unsigned long offset = 0;
787 unsigned long def_mount_opts;
788 long ret = -EINVAL;
789 int blocksize = BLOCK_SIZE;
790 int db_count;
791 int i, j;
792 __le32 features;
793 int err;
794
795 err = -ENOMEM;
796 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
797 if (!sbi)
798 goto failed;
799
800 sbi->s_blockgroup_lock =
801 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
802 if (!sbi->s_blockgroup_lock) {
803 kfree(sbi);
804 goto failed;
805 }
806 sb->s_fs_info = sbi;
807 sbi->s_sb_block = sb_block;
808
809 spin_lock_init(&sbi->s_lock);
810
811 /*
812 * See what the current blocksize for the device is, and
813 * use that as the blocksize. Otherwise (or if the blocksize
814 * is smaller than the default) use the default.
815 * This is important for devices that have a hardware
816 * sectorsize that is larger than the default.
817 */
818 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
819 if (!blocksize) {
820 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
821 goto failed_sbi;
822 }
823
824 /*
825 * If the superblock doesn't start on a hardware sector boundary,
826 * calculate the offset.
827 */
828 if (blocksize != BLOCK_SIZE) {
829 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
830 offset = (sb_block*BLOCK_SIZE) % blocksize;
831 } else {
832 logic_sb_block = sb_block;
833 }
834
835 if (!(bh = sb_bread(sb, logic_sb_block))) {
836 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
837 goto failed_sbi;
838 }
839 /*
840 * Note: s_es must be initialized as soon as possible because
841 * some ext2 macro-instructions depend on its value
842 */
843 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
844 sbi->s_es = es;
845 sb->s_magic = le16_to_cpu(es->s_magic);
846
847 if (sb->s_magic != EXT2_SUPER_MAGIC)
848 goto cantfind_ext2;
849
850 /* Set defaults before we parse the mount options */
851 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
852 if (def_mount_opts & EXT2_DEFM_DEBUG)
853 set_opt(sbi->s_mount_opt, DEBUG);
854 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
855 set_opt(sbi->s_mount_opt, GRPID);
856 if (def_mount_opts & EXT2_DEFM_UID16)
857 set_opt(sbi->s_mount_opt, NO_UID32);
858 #ifdef CONFIG_EXT2_FS_XATTR
859 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
860 set_opt(sbi->s_mount_opt, XATTR_USER);
861 #endif
862 #ifdef CONFIG_EXT2_FS_POSIX_ACL
863 if (def_mount_opts & EXT2_DEFM_ACL)
864 set_opt(sbi->s_mount_opt, POSIX_ACL);
865 #endif
866
867 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
868 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
869 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
870 set_opt(sbi->s_mount_opt, ERRORS_CONT);
871 else
872 set_opt(sbi->s_mount_opt, ERRORS_RO);
873
874 sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
875 sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
876
877 set_opt(sbi->s_mount_opt, RESERVATION);
878
879 if (!parse_options((char *) data, sb))
880 goto failed_mount;
881
882 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
883 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
884 MS_POSIXACL : 0);
885 sb->s_iflags |= SB_I_CGROUPWB;
886
887 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
888 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
889 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
890 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
891 ext2_msg(sb, KERN_WARNING,
892 "warning: feature flags set on rev 0 fs, "
893 "running e2fsck is recommended");
894 /*
895 * Check feature flags regardless of the revision level, since we
896 * previously didn't change the revision level when setting the flags,
897 * so there is a chance incompat flags are set on a rev 0 filesystem.
898 */
899 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
900 if (features) {
901 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
902 "unsupported optional features (%x)",
903 le32_to_cpu(features));
904 goto failed_mount;
905 }
906 if (!(sb->s_flags & MS_RDONLY) &&
907 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
908 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
909 "unsupported optional features (%x)",
910 le32_to_cpu(features));
911 goto failed_mount;
912 }
913
914 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
915
916 if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
917 if (blocksize != PAGE_SIZE) {
918 ext2_msg(sb, KERN_ERR,
919 "error: unsupported blocksize for dax");
920 goto failed_mount;
921 }
922 if (!sb->s_bdev->bd_disk->fops->direct_access) {
923 ext2_msg(sb, KERN_ERR,
924 "error: device does not support dax");
925 goto failed_mount;
926 }
927 }
928
929 /* If the blocksize doesn't match, re-read the thing.. */
930 if (sb->s_blocksize != blocksize) {
931 brelse(bh);
932
933 if (!sb_set_blocksize(sb, blocksize)) {
934 ext2_msg(sb, KERN_ERR,
935 "error: bad blocksize %d", blocksize);
936 goto failed_sbi;
937 }
938
939 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
940 offset = (sb_block*BLOCK_SIZE) % blocksize;
941 bh = sb_bread(sb, logic_sb_block);
942 if(!bh) {
943 ext2_msg(sb, KERN_ERR, "error: couldn't read"
944 "superblock on 2nd try");
945 goto failed_sbi;
946 }
947 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
948 sbi->s_es = es;
949 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
950 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
951 goto failed_mount;
952 }
953 }
954
955 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
956 sb->s_max_links = EXT2_LINK_MAX;
957
958 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
959 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
960 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
961 } else {
962 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
963 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
964 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
965 !is_power_of_2(sbi->s_inode_size) ||
966 (sbi->s_inode_size > blocksize)) {
967 ext2_msg(sb, KERN_ERR,
968 "error: unsupported inode size: %d",
969 sbi->s_inode_size);
970 goto failed_mount;
971 }
972 }
973
974 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
975 le32_to_cpu(es->s_log_frag_size);
976 if (sbi->s_frag_size == 0)
977 goto cantfind_ext2;
978 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
979
980 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
981 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
982 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
983
984 if (EXT2_INODE_SIZE(sb) == 0)
985 goto cantfind_ext2;
986 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
987 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
988 goto cantfind_ext2;
989 sbi->s_itb_per_group = sbi->s_inodes_per_group /
990 sbi->s_inodes_per_block;
991 sbi->s_desc_per_block = sb->s_blocksize /
992 sizeof (struct ext2_group_desc);
993 sbi->s_sbh = bh;
994 sbi->s_mount_state = le16_to_cpu(es->s_state);
995 sbi->s_addr_per_block_bits =
996 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
997 sbi->s_desc_per_block_bits =
998 ilog2 (EXT2_DESC_PER_BLOCK(sb));
999
1000 if (sb->s_magic != EXT2_SUPER_MAGIC)
1001 goto cantfind_ext2;
1002
1003 if (sb->s_blocksize != bh->b_size) {
1004 if (!silent)
1005 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1006 goto failed_mount;
1007 }
1008
1009 if (sb->s_blocksize != sbi->s_frag_size) {
1010 ext2_msg(sb, KERN_ERR,
1011 "error: fragsize %lu != blocksize %lu"
1012 "(not supported yet)",
1013 sbi->s_frag_size, sb->s_blocksize);
1014 goto failed_mount;
1015 }
1016
1017 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1018 ext2_msg(sb, KERN_ERR,
1019 "error: #blocks per group too big: %lu",
1020 sbi->s_blocks_per_group);
1021 goto failed_mount;
1022 }
1023 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1024 ext2_msg(sb, KERN_ERR,
1025 "error: #fragments per group too big: %lu",
1026 sbi->s_frags_per_group);
1027 goto failed_mount;
1028 }
1029 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1030 ext2_msg(sb, KERN_ERR,
1031 "error: #inodes per group too big: %lu",
1032 sbi->s_inodes_per_group);
1033 goto failed_mount;
1034 }
1035
1036 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1037 goto cantfind_ext2;
1038 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1039 le32_to_cpu(es->s_first_data_block) - 1)
1040 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1041 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1042 EXT2_DESC_PER_BLOCK(sb);
1043 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1044 if (sbi->s_group_desc == NULL) {
1045 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1046 goto failed_mount;
1047 }
1048 bgl_lock_init(sbi->s_blockgroup_lock);
1049 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1050 if (!sbi->s_debts) {
1051 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1052 goto failed_mount_group_desc;
1053 }
1054 for (i = 0; i < db_count; i++) {
1055 block = descriptor_loc(sb, logic_sb_block, i);
1056 sbi->s_group_desc[i] = sb_bread(sb, block);
1057 if (!sbi->s_group_desc[i]) {
1058 for (j = 0; j < i; j++)
1059 brelse (sbi->s_group_desc[j]);
1060 ext2_msg(sb, KERN_ERR,
1061 "error: unable to read group descriptors");
1062 goto failed_mount_group_desc;
1063 }
1064 }
1065 if (!ext2_check_descriptors (sb)) {
1066 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1067 goto failed_mount2;
1068 }
1069 sbi->s_gdb_count = db_count;
1070 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1071 spin_lock_init(&sbi->s_next_gen_lock);
1072
1073 /* per fileystem reservation list head & lock */
1074 spin_lock_init(&sbi->s_rsv_window_lock);
1075 sbi->s_rsv_window_root = RB_ROOT;
1076 /*
1077 * Add a single, static dummy reservation to the start of the
1078 * reservation window list --- it gives us a placeholder for
1079 * append-at-start-of-list which makes the allocation logic
1080 * _much_ simpler.
1081 */
1082 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1083 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1084 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1085 sbi->s_rsv_window_head.rsv_goal_size = 0;
1086 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1087
1088 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1089 ext2_count_free_blocks(sb), GFP_KERNEL);
1090 if (!err) {
1091 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1092 ext2_count_free_inodes(sb), GFP_KERNEL);
1093 }
1094 if (!err) {
1095 err = percpu_counter_init(&sbi->s_dirs_counter,
1096 ext2_count_dirs(sb), GFP_KERNEL);
1097 }
1098 if (err) {
1099 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1100 goto failed_mount3;
1101 }
1102 /*
1103 * set up enough so that it can read an inode
1104 */
1105 sb->s_op = &ext2_sops;
1106 sb->s_export_op = &ext2_export_ops;
1107 sb->s_xattr = ext2_xattr_handlers;
1108
1109 #ifdef CONFIG_QUOTA
1110 sb->dq_op = &dquot_operations;
1111 sb->s_qcop = &dquot_quotactl_ops;
1112 sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1113 #endif
1114
1115 root = ext2_iget(sb, EXT2_ROOT_INO);
1116 if (IS_ERR(root)) {
1117 ret = PTR_ERR(root);
1118 goto failed_mount3;
1119 }
1120 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1121 iput(root);
1122 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1123 goto failed_mount3;
1124 }
1125
1126 sb->s_root = d_make_root(root);
1127 if (!sb->s_root) {
1128 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1129 ret = -ENOMEM;
1130 goto failed_mount3;
1131 }
1132 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1133 ext2_msg(sb, KERN_WARNING,
1134 "warning: mounting ext3 filesystem as ext2");
1135 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1136 sb->s_flags |= MS_RDONLY;
1137 ext2_write_super(sb);
1138 return 0;
1139
1140 cantfind_ext2:
1141 if (!silent)
1142 ext2_msg(sb, KERN_ERR,
1143 "error: can't find an ext2 filesystem on dev %s.",
1144 sb->s_id);
1145 goto failed_mount;
1146 failed_mount3:
1147 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1148 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1149 percpu_counter_destroy(&sbi->s_dirs_counter);
1150 failed_mount2:
1151 for (i = 0; i < db_count; i++)
1152 brelse(sbi->s_group_desc[i]);
1153 failed_mount_group_desc:
1154 kfree(sbi->s_group_desc);
1155 kfree(sbi->s_debts);
1156 failed_mount:
1157 brelse(bh);
1158 failed_sbi:
1159 sb->s_fs_info = NULL;
1160 kfree(sbi->s_blockgroup_lock);
1161 kfree(sbi);
1162 failed:
1163 return ret;
1164 }
1165
1166 static void ext2_clear_super_error(struct super_block *sb)
1167 {
1168 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1169
1170 if (buffer_write_io_error(sbh)) {
1171 /*
1172 * Oh, dear. A previous attempt to write the
1173 * superblock failed. This could happen because the
1174 * USB device was yanked out. Or it could happen to
1175 * be a transient write error and maybe the block will
1176 * be remapped. Nothing we can do but to retry the
1177 * write and hope for the best.
1178 */
1179 ext2_msg(sb, KERN_ERR,
1180 "previous I/O error to superblock detected\n");
1181 clear_buffer_write_io_error(sbh);
1182 set_buffer_uptodate(sbh);
1183 }
1184 }
1185
1186 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1187 int wait)
1188 {
1189 ext2_clear_super_error(sb);
1190 spin_lock(&EXT2_SB(sb)->s_lock);
1191 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1192 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1193 es->s_wtime = cpu_to_le32(get_seconds());
1194 /* unlock before we do IO */
1195 spin_unlock(&EXT2_SB(sb)->s_lock);
1196 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1197 if (wait)
1198 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1199 }
1200
1201 /*
1202 * In the second extended file system, it is not necessary to
1203 * write the super block since we use a mapping of the
1204 * disk super block in a buffer.
1205 *
1206 * However, this function is still used to set the fs valid
1207 * flags to 0. We need to set this flag to 0 since the fs
1208 * may have been checked while mounted and e2fsck may have
1209 * set s_state to EXT2_VALID_FS after some corrections.
1210 */
1211 static int ext2_sync_fs(struct super_block *sb, int wait)
1212 {
1213 struct ext2_sb_info *sbi = EXT2_SB(sb);
1214 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1215
1216 /*
1217 * Write quota structures to quota file, sync_blockdev() will write
1218 * them to disk later
1219 */
1220 dquot_writeback_dquots(sb, -1);
1221
1222 spin_lock(&sbi->s_lock);
1223 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1224 ext2_debug("setting valid to 0\n");
1225 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1226 }
1227 spin_unlock(&sbi->s_lock);
1228 ext2_sync_super(sb, es, wait);
1229 return 0;
1230 }
1231
1232 static int ext2_freeze(struct super_block *sb)
1233 {
1234 struct ext2_sb_info *sbi = EXT2_SB(sb);
1235
1236 /*
1237 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1238 * because we have unattached inodes and thus filesystem is not fully
1239 * consistent.
1240 */
1241 if (atomic_long_read(&sb->s_remove_count)) {
1242 ext2_sync_fs(sb, 1);
1243 return 0;
1244 }
1245 /* Set EXT2_FS_VALID flag */
1246 spin_lock(&sbi->s_lock);
1247 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1248 spin_unlock(&sbi->s_lock);
1249 ext2_sync_super(sb, sbi->s_es, 1);
1250
1251 return 0;
1252 }
1253
1254 static int ext2_unfreeze(struct super_block *sb)
1255 {
1256 /* Just write sb to clear EXT2_VALID_FS flag */
1257 ext2_write_super(sb);
1258
1259 return 0;
1260 }
1261
1262 void ext2_write_super(struct super_block *sb)
1263 {
1264 if (!(sb->s_flags & MS_RDONLY))
1265 ext2_sync_fs(sb, 1);
1266 }
1267
1268 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1269 {
1270 struct ext2_sb_info * sbi = EXT2_SB(sb);
1271 struct ext2_super_block * es;
1272 struct ext2_mount_options old_opts;
1273 unsigned long old_sb_flags;
1274 int err;
1275
1276 sync_filesystem(sb);
1277 spin_lock(&sbi->s_lock);
1278
1279 /* Store the old options */
1280 old_sb_flags = sb->s_flags;
1281 old_opts.s_mount_opt = sbi->s_mount_opt;
1282 old_opts.s_resuid = sbi->s_resuid;
1283 old_opts.s_resgid = sbi->s_resgid;
1284
1285 /*
1286 * Allow the "check" option to be passed as a remount option.
1287 */
1288 if (!parse_options(data, sb)) {
1289 err = -EINVAL;
1290 goto restore_opts;
1291 }
1292
1293 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1294 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1295
1296 es = sbi->s_es;
1297 if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1298 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1299 "dax flag with busy inodes while remounting");
1300 sbi->s_mount_opt ^= EXT2_MOUNT_DAX;
1301 }
1302 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1303 spin_unlock(&sbi->s_lock);
1304 return 0;
1305 }
1306 if (*flags & MS_RDONLY) {
1307 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1308 !(sbi->s_mount_state & EXT2_VALID_FS)) {
1309 spin_unlock(&sbi->s_lock);
1310 return 0;
1311 }
1312
1313 /*
1314 * OK, we are remounting a valid rw partition rdonly, so set
1315 * the rdonly flag and then mark the partition as valid again.
1316 */
1317 es->s_state = cpu_to_le16(sbi->s_mount_state);
1318 es->s_mtime = cpu_to_le32(get_seconds());
1319 spin_unlock(&sbi->s_lock);
1320
1321 err = dquot_suspend(sb, -1);
1322 if (err < 0) {
1323 spin_lock(&sbi->s_lock);
1324 goto restore_opts;
1325 }
1326
1327 ext2_sync_super(sb, es, 1);
1328 } else {
1329 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1330 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1331 if (ret) {
1332 ext2_msg(sb, KERN_WARNING,
1333 "warning: couldn't remount RDWR because of "
1334 "unsupported optional features (%x).",
1335 le32_to_cpu(ret));
1336 err = -EROFS;
1337 goto restore_opts;
1338 }
1339 /*
1340 * Mounting a RDONLY partition read-write, so reread and
1341 * store the current valid flag. (It may have been changed
1342 * by e2fsck since we originally mounted the partition.)
1343 */
1344 sbi->s_mount_state = le16_to_cpu(es->s_state);
1345 if (!ext2_setup_super (sb, es, 0))
1346 sb->s_flags &= ~MS_RDONLY;
1347 spin_unlock(&sbi->s_lock);
1348
1349 ext2_write_super(sb);
1350
1351 dquot_resume(sb, -1);
1352 }
1353
1354 return 0;
1355 restore_opts:
1356 sbi->s_mount_opt = old_opts.s_mount_opt;
1357 sbi->s_resuid = old_opts.s_resuid;
1358 sbi->s_resgid = old_opts.s_resgid;
1359 sb->s_flags = old_sb_flags;
1360 spin_unlock(&sbi->s_lock);
1361 return err;
1362 }
1363
1364 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1365 {
1366 struct super_block *sb = dentry->d_sb;
1367 struct ext2_sb_info *sbi = EXT2_SB(sb);
1368 struct ext2_super_block *es = sbi->s_es;
1369 u64 fsid;
1370
1371 spin_lock(&sbi->s_lock);
1372
1373 if (test_opt (sb, MINIX_DF))
1374 sbi->s_overhead_last = 0;
1375 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1376 unsigned long i, overhead = 0;
1377 smp_rmb();
1378
1379 /*
1380 * Compute the overhead (FS structures). This is constant
1381 * for a given filesystem unless the number of block groups
1382 * changes so we cache the previous value until it does.
1383 */
1384
1385 /*
1386 * All of the blocks before first_data_block are
1387 * overhead
1388 */
1389 overhead = le32_to_cpu(es->s_first_data_block);
1390
1391 /*
1392 * Add the overhead attributed to the superblock and
1393 * block group descriptors. If the sparse superblocks
1394 * feature is turned on, then not all groups have this.
1395 */
1396 for (i = 0; i < sbi->s_groups_count; i++)
1397 overhead += ext2_bg_has_super(sb, i) +
1398 ext2_bg_num_gdb(sb, i);
1399
1400 /*
1401 * Every block group has an inode bitmap, a block
1402 * bitmap, and an inode table.
1403 */
1404 overhead += (sbi->s_groups_count *
1405 (2 + sbi->s_itb_per_group));
1406 sbi->s_overhead_last = overhead;
1407 smp_wmb();
1408 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1409 }
1410
1411 buf->f_type = EXT2_SUPER_MAGIC;
1412 buf->f_bsize = sb->s_blocksize;
1413 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1414 buf->f_bfree = ext2_count_free_blocks(sb);
1415 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1416 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1417 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1418 buf->f_bavail = 0;
1419 buf->f_files = le32_to_cpu(es->s_inodes_count);
1420 buf->f_ffree = ext2_count_free_inodes(sb);
1421 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1422 buf->f_namelen = EXT2_NAME_LEN;
1423 fsid = le64_to_cpup((void *)es->s_uuid) ^
1424 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1425 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1426 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1427 spin_unlock(&sbi->s_lock);
1428 return 0;
1429 }
1430
1431 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1432 int flags, const char *dev_name, void *data)
1433 {
1434 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1435 }
1436
1437 #ifdef CONFIG_QUOTA
1438
1439 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1440 * acquiring the locks... As quota files are never truncated and quota code
1441 * itself serializes the operations (and no one else should touch the files)
1442 * we don't have to be afraid of races */
1443 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1444 size_t len, loff_t off)
1445 {
1446 struct inode *inode = sb_dqopt(sb)->files[type];
1447 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1448 int err = 0;
1449 int offset = off & (sb->s_blocksize - 1);
1450 int tocopy;
1451 size_t toread;
1452 struct buffer_head tmp_bh;
1453 struct buffer_head *bh;
1454 loff_t i_size = i_size_read(inode);
1455
1456 if (off > i_size)
1457 return 0;
1458 if (off+len > i_size)
1459 len = i_size-off;
1460 toread = len;
1461 while (toread > 0) {
1462 tocopy = sb->s_blocksize - offset < toread ?
1463 sb->s_blocksize - offset : toread;
1464
1465 tmp_bh.b_state = 0;
1466 tmp_bh.b_size = sb->s_blocksize;
1467 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1468 if (err < 0)
1469 return err;
1470 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1471 memset(data, 0, tocopy);
1472 else {
1473 bh = sb_bread(sb, tmp_bh.b_blocknr);
1474 if (!bh)
1475 return -EIO;
1476 memcpy(data, bh->b_data+offset, tocopy);
1477 brelse(bh);
1478 }
1479 offset = 0;
1480 toread -= tocopy;
1481 data += tocopy;
1482 blk++;
1483 }
1484 return len;
1485 }
1486
1487 /* Write to quotafile */
1488 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1489 const char *data, size_t len, loff_t off)
1490 {
1491 struct inode *inode = sb_dqopt(sb)->files[type];
1492 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1493 int err = 0;
1494 int offset = off & (sb->s_blocksize - 1);
1495 int tocopy;
1496 size_t towrite = len;
1497 struct buffer_head tmp_bh;
1498 struct buffer_head *bh;
1499
1500 while (towrite > 0) {
1501 tocopy = sb->s_blocksize - offset < towrite ?
1502 sb->s_blocksize - offset : towrite;
1503
1504 tmp_bh.b_state = 0;
1505 tmp_bh.b_size = sb->s_blocksize;
1506 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1507 if (err < 0)
1508 goto out;
1509 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1510 bh = sb_bread(sb, tmp_bh.b_blocknr);
1511 else
1512 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1513 if (unlikely(!bh)) {
1514 err = -EIO;
1515 goto out;
1516 }
1517 lock_buffer(bh);
1518 memcpy(bh->b_data+offset, data, tocopy);
1519 flush_dcache_page(bh->b_page);
1520 set_buffer_uptodate(bh);
1521 mark_buffer_dirty(bh);
1522 unlock_buffer(bh);
1523 brelse(bh);
1524 offset = 0;
1525 towrite -= tocopy;
1526 data += tocopy;
1527 blk++;
1528 }
1529 out:
1530 if (len == towrite)
1531 return err;
1532 if (inode->i_size < off+len-towrite)
1533 i_size_write(inode, off+len-towrite);
1534 inode->i_version++;
1535 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1536 mark_inode_dirty(inode);
1537 return len - towrite;
1538 }
1539
1540 #endif
1541
1542 static struct file_system_type ext2_fs_type = {
1543 .owner = THIS_MODULE,
1544 .name = "ext2",
1545 .mount = ext2_mount,
1546 .kill_sb = kill_block_super,
1547 .fs_flags = FS_REQUIRES_DEV,
1548 };
1549 MODULE_ALIAS_FS("ext2");
1550
1551 static int __init init_ext2_fs(void)
1552 {
1553 int err = init_ext2_xattr();
1554 if (err)
1555 return err;
1556 err = init_inodecache();
1557 if (err)
1558 goto out1;
1559 err = register_filesystem(&ext2_fs_type);
1560 if (err)
1561 goto out;
1562 return 0;
1563 out:
1564 destroy_inodecache();
1565 out1:
1566 exit_ext2_xattr();
1567 return err;
1568 }
1569
1570 static void __exit exit_ext2_fs(void)
1571 {
1572 unregister_filesystem(&ext2_fs_type);
1573 destroy_inodecache();
1574 exit_ext2_xattr();
1575 }
1576
1577 MODULE_AUTHOR("Remy Card and others");
1578 MODULE_DESCRIPTION("Second Extended Filesystem");
1579 MODULE_LICENSE("GPL");
1580 module_init(init_ext2_fs)
1581 module_exit(exit_ext2_fs)
Linux kernel - Deliverables
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