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Merge branch 'for-linus-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git...
[mirror_ubuntu-artful-kernel.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 #ifdef CONFIG_FS_DAX
196 init_rwsem(&ei->dax_sem);
197 #endif
198 inode_init_once(&ei->vfs_inode);
199 }
200
201 static int __init init_inodecache(void)
202 {
203 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
204 sizeof(struct ext2_inode_info),
205 0, (SLAB_RECLAIM_ACCOUNT|
206 SLAB_MEM_SPREAD),
207 init_once);
208 if (ext2_inode_cachep == NULL)
209 return -ENOMEM;
210 return 0;
211 }
212
213 static void destroy_inodecache(void)
214 {
215 /*
216 * Make sure all delayed rcu free inodes are flushed before we
217 * destroy cache.
218 */
219 rcu_barrier();
220 kmem_cache_destroy(ext2_inode_cachep);
221 }
222
223 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
224 {
225 struct super_block *sb = root->d_sb;
226 struct ext2_sb_info *sbi = EXT2_SB(sb);
227 struct ext2_super_block *es = sbi->s_es;
228 unsigned long def_mount_opts;
229
230 spin_lock(&sbi->s_lock);
231 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
232
233 if (sbi->s_sb_block != 1)
234 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
235 if (test_opt(sb, MINIX_DF))
236 seq_puts(seq, ",minixdf");
237 if (test_opt(sb, GRPID))
238 seq_puts(seq, ",grpid");
239 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
240 seq_puts(seq, ",nogrpid");
241 if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
242 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
243 seq_printf(seq, ",resuid=%u",
244 from_kuid_munged(&init_user_ns, sbi->s_resuid));
245 }
246 if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
247 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
248 seq_printf(seq, ",resgid=%u",
249 from_kgid_munged(&init_user_ns, sbi->s_resgid));
250 }
251 if (test_opt(sb, ERRORS_RO)) {
252 int def_errors = le16_to_cpu(es->s_errors);
253
254 if (def_errors == EXT2_ERRORS_PANIC ||
255 def_errors == EXT2_ERRORS_CONTINUE) {
256 seq_puts(seq, ",errors=remount-ro");
257 }
258 }
259 if (test_opt(sb, ERRORS_CONT))
260 seq_puts(seq, ",errors=continue");
261 if (test_opt(sb, ERRORS_PANIC))
262 seq_puts(seq, ",errors=panic");
263 if (test_opt(sb, NO_UID32))
264 seq_puts(seq, ",nouid32");
265 if (test_opt(sb, DEBUG))
266 seq_puts(seq, ",debug");
267 if (test_opt(sb, OLDALLOC))
268 seq_puts(seq, ",oldalloc");
269
270 #ifdef CONFIG_EXT2_FS_XATTR
271 if (test_opt(sb, XATTR_USER))
272 seq_puts(seq, ",user_xattr");
273 if (!test_opt(sb, XATTR_USER) &&
274 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
275 seq_puts(seq, ",nouser_xattr");
276 }
277 #endif
278
279 #ifdef CONFIG_EXT2_FS_POSIX_ACL
280 if (test_opt(sb, POSIX_ACL))
281 seq_puts(seq, ",acl");
282 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
283 seq_puts(seq, ",noacl");
284 #endif
285
286 if (test_opt(sb, NOBH))
287 seq_puts(seq, ",nobh");
288
289 #if defined(CONFIG_QUOTA)
290 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
291 seq_puts(seq, ",usrquota");
292
293 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
294 seq_puts(seq, ",grpquota");
295 #endif
296
297 #ifdef CONFIG_FS_DAX
298 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
299 seq_puts(seq, ",xip");
300 if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
301 seq_puts(seq, ",dax");
302 #endif
303
304 if (!test_opt(sb, RESERVATION))
305 seq_puts(seq, ",noreservation");
306
307 spin_unlock(&sbi->s_lock);
308 return 0;
309 }
310
311 #ifdef CONFIG_QUOTA
312 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
313 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
314 static struct dquot **ext2_get_dquots(struct inode *inode)
315 {
316 return EXT2_I(inode)->i_dquot;
317 }
318 #endif
319
320 static const struct super_operations ext2_sops = {
321 .alloc_inode = ext2_alloc_inode,
322 .destroy_inode = ext2_destroy_inode,
323 .write_inode = ext2_write_inode,
324 .evict_inode = ext2_evict_inode,
325 .put_super = ext2_put_super,
326 .sync_fs = ext2_sync_fs,
327 .freeze_fs = ext2_freeze,
328 .unfreeze_fs = ext2_unfreeze,
329 .statfs = ext2_statfs,
330 .remount_fs = ext2_remount,
331 .show_options = ext2_show_options,
332 #ifdef CONFIG_QUOTA
333 .quota_read = ext2_quota_read,
334 .quota_write = ext2_quota_write,
335 .get_dquots = ext2_get_dquots,
336 #endif
337 };
338
339 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
340 u64 ino, u32 generation)
341 {
342 struct inode *inode;
343
344 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
345 return ERR_PTR(-ESTALE);
346 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
347 return ERR_PTR(-ESTALE);
348
349 /*
350 * ext2_iget isn't quite right if the inode is currently unallocated!
351 * However ext2_iget currently does appropriate checks to handle stale
352 * inodes so everything is OK.
353 */
354 inode = ext2_iget(sb, ino);
355 if (IS_ERR(inode))
356 return ERR_CAST(inode);
357 if (generation && inode->i_generation != generation) {
358 /* we didn't find the right inode.. */
359 iput(inode);
360 return ERR_PTR(-ESTALE);
361 }
362 return inode;
363 }
364
365 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
366 int fh_len, int fh_type)
367 {
368 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
369 ext2_nfs_get_inode);
370 }
371
372 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
373 int fh_len, int fh_type)
374 {
375 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
376 ext2_nfs_get_inode);
377 }
378
379 static const struct export_operations ext2_export_ops = {
380 .fh_to_dentry = ext2_fh_to_dentry,
381 .fh_to_parent = ext2_fh_to_parent,
382 .get_parent = ext2_get_parent,
383 };
384
385 static unsigned long get_sb_block(void **data)
386 {
387 unsigned long sb_block;
388 char *options = (char *) *data;
389
390 if (!options || strncmp(options, "sb=", 3) != 0)
391 return 1; /* Default location */
392 options += 3;
393 sb_block = simple_strtoul(options, &options, 0);
394 if (*options && *options != ',') {
395 printk("EXT2-fs: Invalid sb specification: %s\n",
396 (char *) *data);
397 return 1;
398 }
399 if (*options == ',')
400 options++;
401 *data = (void *) options;
402 return sb_block;
403 }
404
405 enum {
406 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
407 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
408 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
409 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
410 Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
411 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
412 };
413
414 static const match_table_t tokens = {
415 {Opt_bsd_df, "bsddf"},
416 {Opt_minix_df, "minixdf"},
417 {Opt_grpid, "grpid"},
418 {Opt_grpid, "bsdgroups"},
419 {Opt_nogrpid, "nogrpid"},
420 {Opt_nogrpid, "sysvgroups"},
421 {Opt_resgid, "resgid=%u"},
422 {Opt_resuid, "resuid=%u"},
423 {Opt_sb, "sb=%u"},
424 {Opt_err_cont, "errors=continue"},
425 {Opt_err_panic, "errors=panic"},
426 {Opt_err_ro, "errors=remount-ro"},
427 {Opt_nouid32, "nouid32"},
428 {Opt_nocheck, "check=none"},
429 {Opt_nocheck, "nocheck"},
430 {Opt_debug, "debug"},
431 {Opt_oldalloc, "oldalloc"},
432 {Opt_orlov, "orlov"},
433 {Opt_nobh, "nobh"},
434 {Opt_user_xattr, "user_xattr"},
435 {Opt_nouser_xattr, "nouser_xattr"},
436 {Opt_acl, "acl"},
437 {Opt_noacl, "noacl"},
438 {Opt_xip, "xip"},
439 {Opt_dax, "dax"},
440 {Opt_grpquota, "grpquota"},
441 {Opt_ignore, "noquota"},
442 {Opt_quota, "quota"},
443 {Opt_usrquota, "usrquota"},
444 {Opt_reservation, "reservation"},
445 {Opt_noreservation, "noreservation"},
446 {Opt_err, NULL}
447 };
448
449 static int parse_options(char *options, struct super_block *sb)
450 {
451 char *p;
452 struct ext2_sb_info *sbi = EXT2_SB(sb);
453 substring_t args[MAX_OPT_ARGS];
454 int option;
455 kuid_t uid;
456 kgid_t gid;
457
458 if (!options)
459 return 1;
460
461 while ((p = strsep (&options, ",")) != NULL) {
462 int token;
463 if (!*p)
464 continue;
465
466 token = match_token(p, tokens, args);
467 switch (token) {
468 case Opt_bsd_df:
469 clear_opt (sbi->s_mount_opt, MINIX_DF);
470 break;
471 case Opt_minix_df:
472 set_opt (sbi->s_mount_opt, MINIX_DF);
473 break;
474 case Opt_grpid:
475 set_opt (sbi->s_mount_opt, GRPID);
476 break;
477 case Opt_nogrpid:
478 clear_opt (sbi->s_mount_opt, GRPID);
479 break;
480 case Opt_resuid:
481 if (match_int(&args[0], &option))
482 return 0;
483 uid = make_kuid(current_user_ns(), option);
484 if (!uid_valid(uid)) {
485 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
486 return 0;
487
488 }
489 sbi->s_resuid = uid;
490 break;
491 case Opt_resgid:
492 if (match_int(&args[0], &option))
493 return 0;
494 gid = make_kgid(current_user_ns(), option);
495 if (!gid_valid(gid)) {
496 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
497 return 0;
498 }
499 sbi->s_resgid = gid;
500 break;
501 case Opt_sb:
502 /* handled by get_sb_block() instead of here */
503 /* *sb_block = match_int(&args[0]); */
504 break;
505 case Opt_err_panic:
506 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
507 clear_opt (sbi->s_mount_opt, ERRORS_RO);
508 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
509 break;
510 case Opt_err_ro:
511 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
512 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
513 set_opt (sbi->s_mount_opt, ERRORS_RO);
514 break;
515 case Opt_err_cont:
516 clear_opt (sbi->s_mount_opt, ERRORS_RO);
517 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
518 set_opt (sbi->s_mount_opt, ERRORS_CONT);
519 break;
520 case Opt_nouid32:
521 set_opt (sbi->s_mount_opt, NO_UID32);
522 break;
523 case Opt_nocheck:
524 clear_opt (sbi->s_mount_opt, CHECK);
525 break;
526 case Opt_debug:
527 set_opt (sbi->s_mount_opt, DEBUG);
528 break;
529 case Opt_oldalloc:
530 set_opt (sbi->s_mount_opt, OLDALLOC);
531 break;
532 case Opt_orlov:
533 clear_opt (sbi->s_mount_opt, OLDALLOC);
534 break;
535 case Opt_nobh:
536 set_opt (sbi->s_mount_opt, NOBH);
537 break;
538 #ifdef CONFIG_EXT2_FS_XATTR
539 case Opt_user_xattr:
540 set_opt (sbi->s_mount_opt, XATTR_USER);
541 break;
542 case Opt_nouser_xattr:
543 clear_opt (sbi->s_mount_opt, XATTR_USER);
544 break;
545 #else
546 case Opt_user_xattr:
547 case Opt_nouser_xattr:
548 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
549 "not supported");
550 break;
551 #endif
552 #ifdef CONFIG_EXT2_FS_POSIX_ACL
553 case Opt_acl:
554 set_opt(sbi->s_mount_opt, POSIX_ACL);
555 break;
556 case Opt_noacl:
557 clear_opt(sbi->s_mount_opt, POSIX_ACL);
558 break;
559 #else
560 case Opt_acl:
561 case Opt_noacl:
562 ext2_msg(sb, KERN_INFO,
563 "(no)acl options not supported");
564 break;
565 #endif
566 case Opt_xip:
567 ext2_msg(sb, KERN_INFO, "use dax instead of xip");
568 set_opt(sbi->s_mount_opt, XIP);
569 /* Fall through */
570 case Opt_dax:
571 #ifdef CONFIG_FS_DAX
572 set_opt(sbi->s_mount_opt, DAX);
573 #else
574 ext2_msg(sb, KERN_INFO, "dax option not supported");
575 #endif
576 break;
577
578 #if defined(CONFIG_QUOTA)
579 case Opt_quota:
580 case Opt_usrquota:
581 set_opt(sbi->s_mount_opt, USRQUOTA);
582 break;
583
584 case Opt_grpquota:
585 set_opt(sbi->s_mount_opt, GRPQUOTA);
586 break;
587 #else
588 case Opt_quota:
589 case Opt_usrquota:
590 case Opt_grpquota:
591 ext2_msg(sb, KERN_INFO,
592 "quota operations not supported");
593 break;
594 #endif
595
596 case Opt_reservation:
597 set_opt(sbi->s_mount_opt, RESERVATION);
598 ext2_msg(sb, KERN_INFO, "reservations ON");
599 break;
600 case Opt_noreservation:
601 clear_opt(sbi->s_mount_opt, RESERVATION);
602 ext2_msg(sb, KERN_INFO, "reservations OFF");
603 break;
604 case Opt_ignore:
605 break;
606 default:
607 return 0;
608 }
609 }
610 return 1;
611 }
612
613 static int ext2_setup_super (struct super_block * sb,
614 struct ext2_super_block * es,
615 int read_only)
616 {
617 int res = 0;
618 struct ext2_sb_info *sbi = EXT2_SB(sb);
619
620 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
621 ext2_msg(sb, KERN_ERR,
622 "error: revision level too high, "
623 "forcing read-only mode");
624 res = MS_RDONLY;
625 }
626 if (read_only)
627 return res;
628 if (!(sbi->s_mount_state & EXT2_VALID_FS))
629 ext2_msg(sb, KERN_WARNING,
630 "warning: mounting unchecked fs, "
631 "running e2fsck is recommended");
632 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
633 ext2_msg(sb, KERN_WARNING,
634 "warning: mounting fs with errors, "
635 "running e2fsck is recommended");
636 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
637 le16_to_cpu(es->s_mnt_count) >=
638 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
639 ext2_msg(sb, KERN_WARNING,
640 "warning: maximal mount count reached, "
641 "running e2fsck is recommended");
642 else if (le32_to_cpu(es->s_checkinterval) &&
643 (le32_to_cpu(es->s_lastcheck) +
644 le32_to_cpu(es->s_checkinterval) <= get_seconds()))
645 ext2_msg(sb, KERN_WARNING,
646 "warning: checktime reached, "
647 "running e2fsck is recommended");
648 if (!le16_to_cpu(es->s_max_mnt_count))
649 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
650 le16_add_cpu(&es->s_mnt_count, 1);
651 if (test_opt (sb, DEBUG))
652 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
653 "bpg=%lu, ipg=%lu, mo=%04lx]",
654 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
655 sbi->s_frag_size,
656 sbi->s_groups_count,
657 EXT2_BLOCKS_PER_GROUP(sb),
658 EXT2_INODES_PER_GROUP(sb),
659 sbi->s_mount_opt);
660 return res;
661 }
662
663 static int ext2_check_descriptors(struct super_block *sb)
664 {
665 int i;
666 struct ext2_sb_info *sbi = EXT2_SB(sb);
667
668 ext2_debug ("Checking group descriptors");
669
670 for (i = 0; i < sbi->s_groups_count; i++) {
671 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
672 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
673 ext2_fsblk_t last_block;
674
675 if (i == sbi->s_groups_count - 1)
676 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
677 else
678 last_block = first_block +
679 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
680
681 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
682 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
683 {
684 ext2_error (sb, "ext2_check_descriptors",
685 "Block bitmap for group %d"
686 " not in group (block %lu)!",
687 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
688 return 0;
689 }
690 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
691 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
692 {
693 ext2_error (sb, "ext2_check_descriptors",
694 "Inode bitmap for group %d"
695 " not in group (block %lu)!",
696 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
697 return 0;
698 }
699 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
700 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
701 last_block)
702 {
703 ext2_error (sb, "ext2_check_descriptors",
704 "Inode table for group %d"
705 " not in group (block %lu)!",
706 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
707 return 0;
708 }
709 }
710 return 1;
711 }
712
713 /*
714 * Maximal file size. There is a direct, and {,double-,triple-}indirect
715 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
716 * We need to be 1 filesystem block less than the 2^32 sector limit.
717 */
718 static loff_t ext2_max_size(int bits)
719 {
720 loff_t res = EXT2_NDIR_BLOCKS;
721 int meta_blocks;
722 loff_t upper_limit;
723
724 /* This is calculated to be the largest file size for a
725 * dense, file such that the total number of
726 * sectors in the file, including data and all indirect blocks,
727 * does not exceed 2^32 -1
728 * __u32 i_blocks representing the total number of
729 * 512 bytes blocks of the file
730 */
731 upper_limit = (1LL << 32) - 1;
732
733 /* total blocks in file system block size */
734 upper_limit >>= (bits - 9);
735
736
737 /* indirect blocks */
738 meta_blocks = 1;
739 /* double indirect blocks */
740 meta_blocks += 1 + (1LL << (bits-2));
741 /* tripple indirect blocks */
742 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
743
744 upper_limit -= meta_blocks;
745 upper_limit <<= bits;
746
747 res += 1LL << (bits-2);
748 res += 1LL << (2*(bits-2));
749 res += 1LL << (3*(bits-2));
750 res <<= bits;
751 if (res > upper_limit)
752 res = upper_limit;
753
754 if (res > MAX_LFS_FILESIZE)
755 res = MAX_LFS_FILESIZE;
756
757 return res;
758 }
759
760 static unsigned long descriptor_loc(struct super_block *sb,
761 unsigned long logic_sb_block,
762 int nr)
763 {
764 struct ext2_sb_info *sbi = EXT2_SB(sb);
765 unsigned long bg, first_meta_bg;
766 int has_super = 0;
767
768 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
769
770 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
771 nr < first_meta_bg)
772 return (logic_sb_block + nr + 1);
773 bg = sbi->s_desc_per_block * nr;
774 if (ext2_bg_has_super(sb, bg))
775 has_super = 1;
776
777 return ext2_group_first_block_no(sb, bg) + has_super;
778 }
779
780 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
781 {
782 struct buffer_head * bh;
783 struct ext2_sb_info * sbi;
784 struct ext2_super_block * es;
785 struct inode *root;
786 unsigned long block;
787 unsigned long sb_block = get_sb_block(&data);
788 unsigned long logic_sb_block;
789 unsigned long offset = 0;
790 unsigned long def_mount_opts;
791 long ret = -EINVAL;
792 int blocksize = BLOCK_SIZE;
793 int db_count;
794 int i, j;
795 __le32 features;
796 int err;
797
798 err = -ENOMEM;
799 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
800 if (!sbi)
801 goto failed;
802
803 sbi->s_blockgroup_lock =
804 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
805 if (!sbi->s_blockgroup_lock) {
806 kfree(sbi);
807 goto failed;
808 }
809 sb->s_fs_info = sbi;
810 sbi->s_sb_block = sb_block;
811
812 spin_lock_init(&sbi->s_lock);
813
814 /*
815 * See what the current blocksize for the device is, and
816 * use that as the blocksize. Otherwise (or if the blocksize
817 * is smaller than the default) use the default.
818 * This is important for devices that have a hardware
819 * sectorsize that is larger than the default.
820 */
821 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
822 if (!blocksize) {
823 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
824 goto failed_sbi;
825 }
826
827 /*
828 * If the superblock doesn't start on a hardware sector boundary,
829 * calculate the offset.
830 */
831 if (blocksize != BLOCK_SIZE) {
832 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
833 offset = (sb_block*BLOCK_SIZE) % blocksize;
834 } else {
835 logic_sb_block = sb_block;
836 }
837
838 if (!(bh = sb_bread(sb, logic_sb_block))) {
839 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
840 goto failed_sbi;
841 }
842 /*
843 * Note: s_es must be initialized as soon as possible because
844 * some ext2 macro-instructions depend on its value
845 */
846 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
847 sbi->s_es = es;
848 sb->s_magic = le16_to_cpu(es->s_magic);
849
850 if (sb->s_magic != EXT2_SUPER_MAGIC)
851 goto cantfind_ext2;
852
853 /* Set defaults before we parse the mount options */
854 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
855 if (def_mount_opts & EXT2_DEFM_DEBUG)
856 set_opt(sbi->s_mount_opt, DEBUG);
857 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
858 set_opt(sbi->s_mount_opt, GRPID);
859 if (def_mount_opts & EXT2_DEFM_UID16)
860 set_opt(sbi->s_mount_opt, NO_UID32);
861 #ifdef CONFIG_EXT2_FS_XATTR
862 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
863 set_opt(sbi->s_mount_opt, XATTR_USER);
864 #endif
865 #ifdef CONFIG_EXT2_FS_POSIX_ACL
866 if (def_mount_opts & EXT2_DEFM_ACL)
867 set_opt(sbi->s_mount_opt, POSIX_ACL);
868 #endif
869
870 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
871 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
872 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
873 set_opt(sbi->s_mount_opt, ERRORS_CONT);
874 else
875 set_opt(sbi->s_mount_opt, ERRORS_RO);
876
877 sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
878 sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
879
880 set_opt(sbi->s_mount_opt, RESERVATION);
881
882 if (!parse_options((char *) data, sb))
883 goto failed_mount;
884
885 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
886 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
887 MS_POSIXACL : 0);
888 sb->s_iflags |= SB_I_CGROUPWB;
889
890 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
891 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
892 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
893 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
894 ext2_msg(sb, KERN_WARNING,
895 "warning: feature flags set on rev 0 fs, "
896 "running e2fsck is recommended");
897 /*
898 * Check feature flags regardless of the revision level, since we
899 * previously didn't change the revision level when setting the flags,
900 * so there is a chance incompat flags are set on a rev 0 filesystem.
901 */
902 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
903 if (features) {
904 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
905 "unsupported optional features (%x)",
906 le32_to_cpu(features));
907 goto failed_mount;
908 }
909 if (!(sb->s_flags & MS_RDONLY) &&
910 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
911 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
912 "unsupported optional features (%x)",
913 le32_to_cpu(features));
914 goto failed_mount;
915 }
916
917 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
918
919 if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
920 if (blocksize != PAGE_SIZE) {
921 ext2_msg(sb, KERN_ERR,
922 "error: unsupported blocksize for dax");
923 goto failed_mount;
924 }
925 if (!sb->s_bdev->bd_disk->fops->direct_access) {
926 ext2_msg(sb, KERN_ERR,
927 "error: device does not support dax");
928 goto failed_mount;
929 }
930 }
931
932 /* If the blocksize doesn't match, re-read the thing.. */
933 if (sb->s_blocksize != blocksize) {
934 brelse(bh);
935
936 if (!sb_set_blocksize(sb, blocksize)) {
937 ext2_msg(sb, KERN_ERR,
938 "error: bad blocksize %d", blocksize);
939 goto failed_sbi;
940 }
941
942 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
943 offset = (sb_block*BLOCK_SIZE) % blocksize;
944 bh = sb_bread(sb, logic_sb_block);
945 if(!bh) {
946 ext2_msg(sb, KERN_ERR, "error: couldn't read"
947 "superblock on 2nd try");
948 goto failed_sbi;
949 }
950 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
951 sbi->s_es = es;
952 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
953 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
954 goto failed_mount;
955 }
956 }
957
958 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
959 sb->s_max_links = EXT2_LINK_MAX;
960
961 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
962 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
963 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
964 } else {
965 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
966 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
967 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
968 !is_power_of_2(sbi->s_inode_size) ||
969 (sbi->s_inode_size > blocksize)) {
970 ext2_msg(sb, KERN_ERR,
971 "error: unsupported inode size: %d",
972 sbi->s_inode_size);
973 goto failed_mount;
974 }
975 }
976
977 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
978 le32_to_cpu(es->s_log_frag_size);
979 if (sbi->s_frag_size == 0)
980 goto cantfind_ext2;
981 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
982
983 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
984 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
985 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
986
987 if (EXT2_INODE_SIZE(sb) == 0)
988 goto cantfind_ext2;
989 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
990 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
991 goto cantfind_ext2;
992 sbi->s_itb_per_group = sbi->s_inodes_per_group /
993 sbi->s_inodes_per_block;
994 sbi->s_desc_per_block = sb->s_blocksize /
995 sizeof (struct ext2_group_desc);
996 sbi->s_sbh = bh;
997 sbi->s_mount_state = le16_to_cpu(es->s_state);
998 sbi->s_addr_per_block_bits =
999 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1000 sbi->s_desc_per_block_bits =
1001 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1002
1003 if (sb->s_magic != EXT2_SUPER_MAGIC)
1004 goto cantfind_ext2;
1005
1006 if (sb->s_blocksize != bh->b_size) {
1007 if (!silent)
1008 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1009 goto failed_mount;
1010 }
1011
1012 if (sb->s_blocksize != sbi->s_frag_size) {
1013 ext2_msg(sb, KERN_ERR,
1014 "error: fragsize %lu != blocksize %lu"
1015 "(not supported yet)",
1016 sbi->s_frag_size, sb->s_blocksize);
1017 goto failed_mount;
1018 }
1019
1020 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1021 ext2_msg(sb, KERN_ERR,
1022 "error: #blocks per group too big: %lu",
1023 sbi->s_blocks_per_group);
1024 goto failed_mount;
1025 }
1026 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1027 ext2_msg(sb, KERN_ERR,
1028 "error: #fragments per group too big: %lu",
1029 sbi->s_frags_per_group);
1030 goto failed_mount;
1031 }
1032 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1033 ext2_msg(sb, KERN_ERR,
1034 "error: #inodes per group too big: %lu",
1035 sbi->s_inodes_per_group);
1036 goto failed_mount;
1037 }
1038
1039 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1040 goto cantfind_ext2;
1041 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1042 le32_to_cpu(es->s_first_data_block) - 1)
1043 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1044 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1045 EXT2_DESC_PER_BLOCK(sb);
1046 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1047 if (sbi->s_group_desc == NULL) {
1048 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1049 goto failed_mount;
1050 }
1051 bgl_lock_init(sbi->s_blockgroup_lock);
1052 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1053 if (!sbi->s_debts) {
1054 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1055 goto failed_mount_group_desc;
1056 }
1057 for (i = 0; i < db_count; i++) {
1058 block = descriptor_loc(sb, logic_sb_block, i);
1059 sbi->s_group_desc[i] = sb_bread(sb, block);
1060 if (!sbi->s_group_desc[i]) {
1061 for (j = 0; j < i; j++)
1062 brelse (sbi->s_group_desc[j]);
1063 ext2_msg(sb, KERN_ERR,
1064 "error: unable to read group descriptors");
1065 goto failed_mount_group_desc;
1066 }
1067 }
1068 if (!ext2_check_descriptors (sb)) {
1069 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1070 goto failed_mount2;
1071 }
1072 sbi->s_gdb_count = db_count;
1073 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1074 spin_lock_init(&sbi->s_next_gen_lock);
1075
1076 /* per fileystem reservation list head & lock */
1077 spin_lock_init(&sbi->s_rsv_window_lock);
1078 sbi->s_rsv_window_root = RB_ROOT;
1079 /*
1080 * Add a single, static dummy reservation to the start of the
1081 * reservation window list --- it gives us a placeholder for
1082 * append-at-start-of-list which makes the allocation logic
1083 * _much_ simpler.
1084 */
1085 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1086 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1087 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1088 sbi->s_rsv_window_head.rsv_goal_size = 0;
1089 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1090
1091 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1092 ext2_count_free_blocks(sb), GFP_KERNEL);
1093 if (!err) {
1094 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1095 ext2_count_free_inodes(sb), GFP_KERNEL);
1096 }
1097 if (!err) {
1098 err = percpu_counter_init(&sbi->s_dirs_counter,
1099 ext2_count_dirs(sb), GFP_KERNEL);
1100 }
1101 if (err) {
1102 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1103 goto failed_mount3;
1104 }
1105 /*
1106 * set up enough so that it can read an inode
1107 */
1108 sb->s_op = &ext2_sops;
1109 sb->s_export_op = &ext2_export_ops;
1110 sb->s_xattr = ext2_xattr_handlers;
1111
1112 #ifdef CONFIG_QUOTA
1113 sb->dq_op = &dquot_operations;
1114 sb->s_qcop = &dquot_quotactl_ops;
1115 sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1116 #endif
1117
1118 root = ext2_iget(sb, EXT2_ROOT_INO);
1119 if (IS_ERR(root)) {
1120 ret = PTR_ERR(root);
1121 goto failed_mount3;
1122 }
1123 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1124 iput(root);
1125 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1126 goto failed_mount3;
1127 }
1128
1129 sb->s_root = d_make_root(root);
1130 if (!sb->s_root) {
1131 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1132 ret = -ENOMEM;
1133 goto failed_mount3;
1134 }
1135 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1136 ext2_msg(sb, KERN_WARNING,
1137 "warning: mounting ext3 filesystem as ext2");
1138 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1139 sb->s_flags |= MS_RDONLY;
1140 ext2_write_super(sb);
1141 return 0;
1142
1143 cantfind_ext2:
1144 if (!silent)
1145 ext2_msg(sb, KERN_ERR,
1146 "error: can't find an ext2 filesystem on dev %s.",
1147 sb->s_id);
1148 goto failed_mount;
1149 failed_mount3:
1150 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1151 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1152 percpu_counter_destroy(&sbi->s_dirs_counter);
1153 failed_mount2:
1154 for (i = 0; i < db_count; i++)
1155 brelse(sbi->s_group_desc[i]);
1156 failed_mount_group_desc:
1157 kfree(sbi->s_group_desc);
1158 kfree(sbi->s_debts);
1159 failed_mount:
1160 brelse(bh);
1161 failed_sbi:
1162 sb->s_fs_info = NULL;
1163 kfree(sbi->s_blockgroup_lock);
1164 kfree(sbi);
1165 failed:
1166 return ret;
1167 }
1168
1169 static void ext2_clear_super_error(struct super_block *sb)
1170 {
1171 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1172
1173 if (buffer_write_io_error(sbh)) {
1174 /*
1175 * Oh, dear. A previous attempt to write the
1176 * superblock failed. This could happen because the
1177 * USB device was yanked out. Or it could happen to
1178 * be a transient write error and maybe the block will
1179 * be remapped. Nothing we can do but to retry the
1180 * write and hope for the best.
1181 */
1182 ext2_msg(sb, KERN_ERR,
1183 "previous I/O error to superblock detected\n");
1184 clear_buffer_write_io_error(sbh);
1185 set_buffer_uptodate(sbh);
1186 }
1187 }
1188
1189 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1190 int wait)
1191 {
1192 ext2_clear_super_error(sb);
1193 spin_lock(&EXT2_SB(sb)->s_lock);
1194 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1195 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1196 es->s_wtime = cpu_to_le32(get_seconds());
1197 /* unlock before we do IO */
1198 spin_unlock(&EXT2_SB(sb)->s_lock);
1199 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1200 if (wait)
1201 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1202 }
1203
1204 /*
1205 * In the second extended file system, it is not necessary to
1206 * write the super block since we use a mapping of the
1207 * disk super block in a buffer.
1208 *
1209 * However, this function is still used to set the fs valid
1210 * flags to 0. We need to set this flag to 0 since the fs
1211 * may have been checked while mounted and e2fsck may have
1212 * set s_state to EXT2_VALID_FS after some corrections.
1213 */
1214 static int ext2_sync_fs(struct super_block *sb, int wait)
1215 {
1216 struct ext2_sb_info *sbi = EXT2_SB(sb);
1217 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1218
1219 /*
1220 * Write quota structures to quota file, sync_blockdev() will write
1221 * them to disk later
1222 */
1223 dquot_writeback_dquots(sb, -1);
1224
1225 spin_lock(&sbi->s_lock);
1226 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1227 ext2_debug("setting valid to 0\n");
1228 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1229 }
1230 spin_unlock(&sbi->s_lock);
1231 ext2_sync_super(sb, es, wait);
1232 return 0;
1233 }
1234
1235 static int ext2_freeze(struct super_block *sb)
1236 {
1237 struct ext2_sb_info *sbi = EXT2_SB(sb);
1238
1239 /*
1240 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1241 * because we have unattached inodes and thus filesystem is not fully
1242 * consistent.
1243 */
1244 if (atomic_long_read(&sb->s_remove_count)) {
1245 ext2_sync_fs(sb, 1);
1246 return 0;
1247 }
1248 /* Set EXT2_FS_VALID flag */
1249 spin_lock(&sbi->s_lock);
1250 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1251 spin_unlock(&sbi->s_lock);
1252 ext2_sync_super(sb, sbi->s_es, 1);
1253
1254 return 0;
1255 }
1256
1257 static int ext2_unfreeze(struct super_block *sb)
1258 {
1259 /* Just write sb to clear EXT2_VALID_FS flag */
1260 ext2_write_super(sb);
1261
1262 return 0;
1263 }
1264
1265 void ext2_write_super(struct super_block *sb)
1266 {
1267 if (!(sb->s_flags & MS_RDONLY))
1268 ext2_sync_fs(sb, 1);
1269 }
1270
1271 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1272 {
1273 struct ext2_sb_info * sbi = EXT2_SB(sb);
1274 struct ext2_super_block * es;
1275 struct ext2_mount_options old_opts;
1276 unsigned long old_sb_flags;
1277 int err;
1278
1279 sync_filesystem(sb);
1280 spin_lock(&sbi->s_lock);
1281
1282 /* Store the old options */
1283 old_sb_flags = sb->s_flags;
1284 old_opts.s_mount_opt = sbi->s_mount_opt;
1285 old_opts.s_resuid = sbi->s_resuid;
1286 old_opts.s_resgid = sbi->s_resgid;
1287
1288 /*
1289 * Allow the "check" option to be passed as a remount option.
1290 */
1291 if (!parse_options(data, sb)) {
1292 err = -EINVAL;
1293 goto restore_opts;
1294 }
1295
1296 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1297 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1298
1299 es = sbi->s_es;
1300 if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1301 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1302 "dax flag with busy inodes while remounting");
1303 sbi->s_mount_opt ^= EXT2_MOUNT_DAX;
1304 }
1305 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1306 spin_unlock(&sbi->s_lock);
1307 return 0;
1308 }
1309 if (*flags & MS_RDONLY) {
1310 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1311 !(sbi->s_mount_state & EXT2_VALID_FS)) {
1312 spin_unlock(&sbi->s_lock);
1313 return 0;
1314 }
1315
1316 /*
1317 * OK, we are remounting a valid rw partition rdonly, so set
1318 * the rdonly flag and then mark the partition as valid again.
1319 */
1320 es->s_state = cpu_to_le16(sbi->s_mount_state);
1321 es->s_mtime = cpu_to_le32(get_seconds());
1322 spin_unlock(&sbi->s_lock);
1323
1324 err = dquot_suspend(sb, -1);
1325 if (err < 0) {
1326 spin_lock(&sbi->s_lock);
1327 goto restore_opts;
1328 }
1329
1330 ext2_sync_super(sb, es, 1);
1331 } else {
1332 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1333 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1334 if (ret) {
1335 ext2_msg(sb, KERN_WARNING,
1336 "warning: couldn't remount RDWR because of "
1337 "unsupported optional features (%x).",
1338 le32_to_cpu(ret));
1339 err = -EROFS;
1340 goto restore_opts;
1341 }
1342 /*
1343 * Mounting a RDONLY partition read-write, so reread and
1344 * store the current valid flag. (It may have been changed
1345 * by e2fsck since we originally mounted the partition.)
1346 */
1347 sbi->s_mount_state = le16_to_cpu(es->s_state);
1348 if (!ext2_setup_super (sb, es, 0))
1349 sb->s_flags &= ~MS_RDONLY;
1350 spin_unlock(&sbi->s_lock);
1351
1352 ext2_write_super(sb);
1353
1354 dquot_resume(sb, -1);
1355 }
1356
1357 return 0;
1358 restore_opts:
1359 sbi->s_mount_opt = old_opts.s_mount_opt;
1360 sbi->s_resuid = old_opts.s_resuid;
1361 sbi->s_resgid = old_opts.s_resgid;
1362 sb->s_flags = old_sb_flags;
1363 spin_unlock(&sbi->s_lock);
1364 return err;
1365 }
1366
1367 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1368 {
1369 struct super_block *sb = dentry->d_sb;
1370 struct ext2_sb_info *sbi = EXT2_SB(sb);
1371 struct ext2_super_block *es = sbi->s_es;
1372 u64 fsid;
1373
1374 spin_lock(&sbi->s_lock);
1375
1376 if (test_opt (sb, MINIX_DF))
1377 sbi->s_overhead_last = 0;
1378 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1379 unsigned long i, overhead = 0;
1380 smp_rmb();
1381
1382 /*
1383 * Compute the overhead (FS structures). This is constant
1384 * for a given filesystem unless the number of block groups
1385 * changes so we cache the previous value until it does.
1386 */
1387
1388 /*
1389 * All of the blocks before first_data_block are
1390 * overhead
1391 */
1392 overhead = le32_to_cpu(es->s_first_data_block);
1393
1394 /*
1395 * Add the overhead attributed to the superblock and
1396 * block group descriptors. If the sparse superblocks
1397 * feature is turned on, then not all groups have this.
1398 */
1399 for (i = 0; i < sbi->s_groups_count; i++)
1400 overhead += ext2_bg_has_super(sb, i) +
1401 ext2_bg_num_gdb(sb, i);
1402
1403 /*
1404 * Every block group has an inode bitmap, a block
1405 * bitmap, and an inode table.
1406 */
1407 overhead += (sbi->s_groups_count *
1408 (2 + sbi->s_itb_per_group));
1409 sbi->s_overhead_last = overhead;
1410 smp_wmb();
1411 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1412 }
1413
1414 buf->f_type = EXT2_SUPER_MAGIC;
1415 buf->f_bsize = sb->s_blocksize;
1416 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1417 buf->f_bfree = ext2_count_free_blocks(sb);
1418 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1419 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1420 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1421 buf->f_bavail = 0;
1422 buf->f_files = le32_to_cpu(es->s_inodes_count);
1423 buf->f_ffree = ext2_count_free_inodes(sb);
1424 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1425 buf->f_namelen = EXT2_NAME_LEN;
1426 fsid = le64_to_cpup((void *)es->s_uuid) ^
1427 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1428 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1429 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1430 spin_unlock(&sbi->s_lock);
1431 return 0;
1432 }
1433
1434 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1435 int flags, const char *dev_name, void *data)
1436 {
1437 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1438 }
1439
1440 #ifdef CONFIG_QUOTA
1441
1442 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1443 * acquiring the locks... As quota files are never truncated and quota code
1444 * itself serializes the operations (and no one else should touch the files)
1445 * we don't have to be afraid of races */
1446 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1447 size_t len, loff_t off)
1448 {
1449 struct inode *inode = sb_dqopt(sb)->files[type];
1450 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1451 int err = 0;
1452 int offset = off & (sb->s_blocksize - 1);
1453 int tocopy;
1454 size_t toread;
1455 struct buffer_head tmp_bh;
1456 struct buffer_head *bh;
1457 loff_t i_size = i_size_read(inode);
1458
1459 if (off > i_size)
1460 return 0;
1461 if (off+len > i_size)
1462 len = i_size-off;
1463 toread = len;
1464 while (toread > 0) {
1465 tocopy = sb->s_blocksize - offset < toread ?
1466 sb->s_blocksize - offset : toread;
1467
1468 tmp_bh.b_state = 0;
1469 tmp_bh.b_size = sb->s_blocksize;
1470 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1471 if (err < 0)
1472 return err;
1473 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1474 memset(data, 0, tocopy);
1475 else {
1476 bh = sb_bread(sb, tmp_bh.b_blocknr);
1477 if (!bh)
1478 return -EIO;
1479 memcpy(data, bh->b_data+offset, tocopy);
1480 brelse(bh);
1481 }
1482 offset = 0;
1483 toread -= tocopy;
1484 data += tocopy;
1485 blk++;
1486 }
1487 return len;
1488 }
1489
1490 /* Write to quotafile */
1491 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1492 const char *data, size_t len, loff_t off)
1493 {
1494 struct inode *inode = sb_dqopt(sb)->files[type];
1495 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1496 int err = 0;
1497 int offset = off & (sb->s_blocksize - 1);
1498 int tocopy;
1499 size_t towrite = len;
1500 struct buffer_head tmp_bh;
1501 struct buffer_head *bh;
1502
1503 while (towrite > 0) {
1504 tocopy = sb->s_blocksize - offset < towrite ?
1505 sb->s_blocksize - offset : towrite;
1506
1507 tmp_bh.b_state = 0;
1508 tmp_bh.b_size = sb->s_blocksize;
1509 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1510 if (err < 0)
1511 goto out;
1512 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1513 bh = sb_bread(sb, tmp_bh.b_blocknr);
1514 else
1515 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1516 if (unlikely(!bh)) {
1517 err = -EIO;
1518 goto out;
1519 }
1520 lock_buffer(bh);
1521 memcpy(bh->b_data+offset, data, tocopy);
1522 flush_dcache_page(bh->b_page);
1523 set_buffer_uptodate(bh);
1524 mark_buffer_dirty(bh);
1525 unlock_buffer(bh);
1526 brelse(bh);
1527 offset = 0;
1528 towrite -= tocopy;
1529 data += tocopy;
1530 blk++;
1531 }
1532 out:
1533 if (len == towrite)
1534 return err;
1535 if (inode->i_size < off+len-towrite)
1536 i_size_write(inode, off+len-towrite);
1537 inode->i_version++;
1538 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1539 mark_inode_dirty(inode);
1540 return len - towrite;
1541 }
1542
1543 #endif
1544
1545 static struct file_system_type ext2_fs_type = {
1546 .owner = THIS_MODULE,
1547 .name = "ext2",
1548 .mount = ext2_mount,
1549 .kill_sb = kill_block_super,
1550 .fs_flags = FS_REQUIRES_DEV,
1551 };
1552 MODULE_ALIAS_FS("ext2");
1553
1554 static int __init init_ext2_fs(void)
1555 {
1556 int err = init_ext2_xattr();
1557 if (err)
1558 return err;
1559 err = init_inodecache();
1560 if (err)
1561 goto out1;
1562 err = register_filesystem(&ext2_fs_type);
1563 if (err)
1564 goto out;
1565 return 0;
1566 out:
1567 destroy_inodecache();
1568 out1:
1569 exit_ext2_xattr();
1570 return err;
1571 }
1572
1573 static void __exit exit_ext2_fs(void)
1574 {
1575 unregister_filesystem(&ext2_fs_type);
1576 destroy_inodecache();
1577 exit_ext2_xattr();
1578 }
1579
1580 MODULE_AUTHOR("Remy Card and others");
1581 MODULE_DESCRIPTION("Second Extended Filesystem");
1582 MODULE_LICENSE("GPL");
1583 module_init(init_ext2_fs)
1584 module_exit(exit_ext2_fs)
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