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[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 #include "xip.h"
39
40 static void ext2_sync_super(struct super_block *sb,
41 struct ext2_super_block *es, int wait);
42 static int ext2_remount (struct super_block * sb, int * flags, char * data);
43 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
44 static int ext2_sync_fs(struct super_block *sb, int wait);
45 static int ext2_freeze(struct super_block *sb);
46 static int ext2_unfreeze(struct super_block *sb);
47
48 void ext2_error(struct super_block *sb, const char *function,
49 const char *fmt, ...)
50 {
51 struct va_format vaf;
52 va_list args;
53 struct ext2_sb_info *sbi = EXT2_SB(sb);
54 struct ext2_super_block *es = sbi->s_es;
55
56 if (!(sb->s_flags & MS_RDONLY)) {
57 spin_lock(&sbi->s_lock);
58 sbi->s_mount_state |= EXT2_ERROR_FS;
59 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
60 spin_unlock(&sbi->s_lock);
61 ext2_sync_super(sb, es, 1);
62 }
63
64 va_start(args, fmt);
65
66 vaf.fmt = fmt;
67 vaf.va = &args;
68
69 printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
70 sb->s_id, function, &vaf);
71
72 va_end(args);
73
74 if (test_opt(sb, ERRORS_PANIC))
75 panic("EXT2-fs: panic from previous error\n");
76 if (test_opt(sb, ERRORS_RO)) {
77 ext2_msg(sb, KERN_CRIT,
78 "error: remounting filesystem read-only");
79 sb->s_flags |= MS_RDONLY;
80 }
81 }
82
83 void ext2_msg(struct super_block *sb, const char *prefix,
84 const char *fmt, ...)
85 {
86 struct va_format vaf;
87 va_list args;
88
89 va_start(args, fmt);
90
91 vaf.fmt = fmt;
92 vaf.va = &args;
93
94 printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
95
96 va_end(args);
97 }
98
99 /*
100 * This must be called with sbi->s_lock held.
101 */
102 void ext2_update_dynamic_rev(struct super_block *sb)
103 {
104 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
105
106 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
107 return;
108
109 ext2_msg(sb, KERN_WARNING,
110 "warning: updating to rev %d because of "
111 "new feature flag, running e2fsck is recommended",
112 EXT2_DYNAMIC_REV);
113
114 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
115 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
116 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
117 /* leave es->s_feature_*compat flags alone */
118 /* es->s_uuid will be set by e2fsck if empty */
119
120 /*
121 * The rest of the superblock fields should be zero, and if not it
122 * means they are likely already in use, so leave them alone. We
123 * can leave it up to e2fsck to clean up any inconsistencies there.
124 */
125 }
126
127 static void ext2_put_super (struct super_block * sb)
128 {
129 int db_count;
130 int i;
131 struct ext2_sb_info *sbi = EXT2_SB(sb);
132
133 dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
134
135 ext2_xattr_put_super(sb);
136 if (!(sb->s_flags & MS_RDONLY)) {
137 struct ext2_super_block *es = sbi->s_es;
138
139 spin_lock(&sbi->s_lock);
140 es->s_state = cpu_to_le16(sbi->s_mount_state);
141 spin_unlock(&sbi->s_lock);
142 ext2_sync_super(sb, es, 1);
143 }
144 db_count = sbi->s_gdb_count;
145 for (i = 0; i < db_count; i++)
146 if (sbi->s_group_desc[i])
147 brelse (sbi->s_group_desc[i]);
148 kfree(sbi->s_group_desc);
149 kfree(sbi->s_debts);
150 percpu_counter_destroy(&sbi->s_freeblocks_counter);
151 percpu_counter_destroy(&sbi->s_freeinodes_counter);
152 percpu_counter_destroy(&sbi->s_dirs_counter);
153 brelse (sbi->s_sbh);
154 sb->s_fs_info = NULL;
155 kfree(sbi->s_blockgroup_lock);
156 kfree(sbi);
157 }
158
159 static struct kmem_cache * ext2_inode_cachep;
160
161 static struct inode *ext2_alloc_inode(struct super_block *sb)
162 {
163 struct ext2_inode_info *ei;
164 ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
165 if (!ei)
166 return NULL;
167 ei->i_block_alloc_info = NULL;
168 ei->vfs_inode.i_version = 1;
169 return &ei->vfs_inode;
170 }
171
172 static void ext2_i_callback(struct rcu_head *head)
173 {
174 struct inode *inode = container_of(head, struct inode, i_rcu);
175 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
176 }
177
178 static void ext2_destroy_inode(struct inode *inode)
179 {
180 call_rcu(&inode->i_rcu, ext2_i_callback);
181 }
182
183 static void init_once(void *foo)
184 {
185 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
186
187 rwlock_init(&ei->i_meta_lock);
188 #ifdef CONFIG_EXT2_FS_XATTR
189 init_rwsem(&ei->xattr_sem);
190 #endif
191 mutex_init(&ei->truncate_mutex);
192 inode_init_once(&ei->vfs_inode);
193 }
194
195 static int __init init_inodecache(void)
196 {
197 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
198 sizeof(struct ext2_inode_info),
199 0, (SLAB_RECLAIM_ACCOUNT|
200 SLAB_MEM_SPREAD),
201 init_once);
202 if (ext2_inode_cachep == NULL)
203 return -ENOMEM;
204 return 0;
205 }
206
207 static void destroy_inodecache(void)
208 {
209 /*
210 * Make sure all delayed rcu free inodes are flushed before we
211 * destroy cache.
212 */
213 rcu_barrier();
214 kmem_cache_destroy(ext2_inode_cachep);
215 }
216
217 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
218 {
219 struct super_block *sb = root->d_sb;
220 struct ext2_sb_info *sbi = EXT2_SB(sb);
221 struct ext2_super_block *es = sbi->s_es;
222 unsigned long def_mount_opts;
223
224 spin_lock(&sbi->s_lock);
225 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
226
227 if (sbi->s_sb_block != 1)
228 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
229 if (test_opt(sb, MINIX_DF))
230 seq_puts(seq, ",minixdf");
231 if (test_opt(sb, GRPID))
232 seq_puts(seq, ",grpid");
233 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
234 seq_puts(seq, ",nogrpid");
235 if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
236 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
237 seq_printf(seq, ",resuid=%u",
238 from_kuid_munged(&init_user_ns, sbi->s_resuid));
239 }
240 if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
241 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
242 seq_printf(seq, ",resgid=%u",
243 from_kgid_munged(&init_user_ns, sbi->s_resgid));
244 }
245 if (test_opt(sb, ERRORS_RO)) {
246 int def_errors = le16_to_cpu(es->s_errors);
247
248 if (def_errors == EXT2_ERRORS_PANIC ||
249 def_errors == EXT2_ERRORS_CONTINUE) {
250 seq_puts(seq, ",errors=remount-ro");
251 }
252 }
253 if (test_opt(sb, ERRORS_CONT))
254 seq_puts(seq, ",errors=continue");
255 if (test_opt(sb, ERRORS_PANIC))
256 seq_puts(seq, ",errors=panic");
257 if (test_opt(sb, NO_UID32))
258 seq_puts(seq, ",nouid32");
259 if (test_opt(sb, DEBUG))
260 seq_puts(seq, ",debug");
261 if (test_opt(sb, OLDALLOC))
262 seq_puts(seq, ",oldalloc");
263
264 #ifdef CONFIG_EXT2_FS_XATTR
265 if (test_opt(sb, XATTR_USER))
266 seq_puts(seq, ",user_xattr");
267 if (!test_opt(sb, XATTR_USER) &&
268 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
269 seq_puts(seq, ",nouser_xattr");
270 }
271 #endif
272
273 #ifdef CONFIG_EXT2_FS_POSIX_ACL
274 if (test_opt(sb, POSIX_ACL))
275 seq_puts(seq, ",acl");
276 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
277 seq_puts(seq, ",noacl");
278 #endif
279
280 if (test_opt(sb, NOBH))
281 seq_puts(seq, ",nobh");
282
283 #if defined(CONFIG_QUOTA)
284 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
285 seq_puts(seq, ",usrquota");
286
287 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
288 seq_puts(seq, ",grpquota");
289 #endif
290
291 #if defined(CONFIG_EXT2_FS_XIP)
292 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
293 seq_puts(seq, ",xip");
294 #endif
295
296 if (!test_opt(sb, RESERVATION))
297 seq_puts(seq, ",noreservation");
298
299 spin_unlock(&sbi->s_lock);
300 return 0;
301 }
302
303 #ifdef CONFIG_QUOTA
304 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
305 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
306 #endif
307
308 static const struct super_operations ext2_sops = {
309 .alloc_inode = ext2_alloc_inode,
310 .destroy_inode = ext2_destroy_inode,
311 .write_inode = ext2_write_inode,
312 .evict_inode = ext2_evict_inode,
313 .put_super = ext2_put_super,
314 .sync_fs = ext2_sync_fs,
315 .freeze_fs = ext2_freeze,
316 .unfreeze_fs = ext2_unfreeze,
317 .statfs = ext2_statfs,
318 .remount_fs = ext2_remount,
319 .show_options = ext2_show_options,
320 #ifdef CONFIG_QUOTA
321 .quota_read = ext2_quota_read,
322 .quota_write = ext2_quota_write,
323 #endif
324 };
325
326 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
327 u64 ino, u32 generation)
328 {
329 struct inode *inode;
330
331 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
332 return ERR_PTR(-ESTALE);
333 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
334 return ERR_PTR(-ESTALE);
335
336 /*
337 * ext2_iget isn't quite right if the inode is currently unallocated!
338 * However ext2_iget currently does appropriate checks to handle stale
339 * inodes so everything is OK.
340 */
341 inode = ext2_iget(sb, ino);
342 if (IS_ERR(inode))
343 return ERR_CAST(inode);
344 if (generation && inode->i_generation != generation) {
345 /* we didn't find the right inode.. */
346 iput(inode);
347 return ERR_PTR(-ESTALE);
348 }
349 return inode;
350 }
351
352 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
353 int fh_len, int fh_type)
354 {
355 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
356 ext2_nfs_get_inode);
357 }
358
359 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
360 int fh_len, int fh_type)
361 {
362 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
363 ext2_nfs_get_inode);
364 }
365
366 static const struct export_operations ext2_export_ops = {
367 .fh_to_dentry = ext2_fh_to_dentry,
368 .fh_to_parent = ext2_fh_to_parent,
369 .get_parent = ext2_get_parent,
370 };
371
372 static unsigned long get_sb_block(void **data)
373 {
374 unsigned long sb_block;
375 char *options = (char *) *data;
376
377 if (!options || strncmp(options, "sb=", 3) != 0)
378 return 1; /* Default location */
379 options += 3;
380 sb_block = simple_strtoul(options, &options, 0);
381 if (*options && *options != ',') {
382 printk("EXT2-fs: Invalid sb specification: %s\n",
383 (char *) *data);
384 return 1;
385 }
386 if (*options == ',')
387 options++;
388 *data = (void *) options;
389 return sb_block;
390 }
391
392 enum {
393 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
394 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
395 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
396 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
397 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
398 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
399 };
400
401 static const match_table_t tokens = {
402 {Opt_bsd_df, "bsddf"},
403 {Opt_minix_df, "minixdf"},
404 {Opt_grpid, "grpid"},
405 {Opt_grpid, "bsdgroups"},
406 {Opt_nogrpid, "nogrpid"},
407 {Opt_nogrpid, "sysvgroups"},
408 {Opt_resgid, "resgid=%u"},
409 {Opt_resuid, "resuid=%u"},
410 {Opt_sb, "sb=%u"},
411 {Opt_err_cont, "errors=continue"},
412 {Opt_err_panic, "errors=panic"},
413 {Opt_err_ro, "errors=remount-ro"},
414 {Opt_nouid32, "nouid32"},
415 {Opt_nocheck, "check=none"},
416 {Opt_nocheck, "nocheck"},
417 {Opt_debug, "debug"},
418 {Opt_oldalloc, "oldalloc"},
419 {Opt_orlov, "orlov"},
420 {Opt_nobh, "nobh"},
421 {Opt_user_xattr, "user_xattr"},
422 {Opt_nouser_xattr, "nouser_xattr"},
423 {Opt_acl, "acl"},
424 {Opt_noacl, "noacl"},
425 {Opt_xip, "xip"},
426 {Opt_grpquota, "grpquota"},
427 {Opt_ignore, "noquota"},
428 {Opt_quota, "quota"},
429 {Opt_usrquota, "usrquota"},
430 {Opt_reservation, "reservation"},
431 {Opt_noreservation, "noreservation"},
432 {Opt_err, NULL}
433 };
434
435 static int parse_options(char *options, struct super_block *sb)
436 {
437 char *p;
438 struct ext2_sb_info *sbi = EXT2_SB(sb);
439 substring_t args[MAX_OPT_ARGS];
440 int option;
441 kuid_t uid;
442 kgid_t gid;
443
444 if (!options)
445 return 1;
446
447 while ((p = strsep (&options, ",")) != NULL) {
448 int token;
449 if (!*p)
450 continue;
451
452 token = match_token(p, tokens, args);
453 switch (token) {
454 case Opt_bsd_df:
455 clear_opt (sbi->s_mount_opt, MINIX_DF);
456 break;
457 case Opt_minix_df:
458 set_opt (sbi->s_mount_opt, MINIX_DF);
459 break;
460 case Opt_grpid:
461 set_opt (sbi->s_mount_opt, GRPID);
462 break;
463 case Opt_nogrpid:
464 clear_opt (sbi->s_mount_opt, GRPID);
465 break;
466 case Opt_resuid:
467 if (match_int(&args[0], &option))
468 return 0;
469 uid = make_kuid(current_user_ns(), option);
470 if (!uid_valid(uid)) {
471 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
472 return 0;
473
474 }
475 sbi->s_resuid = uid;
476 break;
477 case Opt_resgid:
478 if (match_int(&args[0], &option))
479 return 0;
480 gid = make_kgid(current_user_ns(), option);
481 if (!gid_valid(gid)) {
482 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
483 return 0;
484 }
485 sbi->s_resgid = gid;
486 break;
487 case Opt_sb:
488 /* handled by get_sb_block() instead of here */
489 /* *sb_block = match_int(&args[0]); */
490 break;
491 case Opt_err_panic:
492 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
493 clear_opt (sbi->s_mount_opt, ERRORS_RO);
494 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
495 break;
496 case Opt_err_ro:
497 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
498 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
499 set_opt (sbi->s_mount_opt, ERRORS_RO);
500 break;
501 case Opt_err_cont:
502 clear_opt (sbi->s_mount_opt, ERRORS_RO);
503 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
504 set_opt (sbi->s_mount_opt, ERRORS_CONT);
505 break;
506 case Opt_nouid32:
507 set_opt (sbi->s_mount_opt, NO_UID32);
508 break;
509 case Opt_nocheck:
510 clear_opt (sbi->s_mount_opt, CHECK);
511 break;
512 case Opt_debug:
513 set_opt (sbi->s_mount_opt, DEBUG);
514 break;
515 case Opt_oldalloc:
516 set_opt (sbi->s_mount_opt, OLDALLOC);
517 break;
518 case Opt_orlov:
519 clear_opt (sbi->s_mount_opt, OLDALLOC);
520 break;
521 case Opt_nobh:
522 set_opt (sbi->s_mount_opt, NOBH);
523 break;
524 #ifdef CONFIG_EXT2_FS_XATTR
525 case Opt_user_xattr:
526 set_opt (sbi->s_mount_opt, XATTR_USER);
527 break;
528 case Opt_nouser_xattr:
529 clear_opt (sbi->s_mount_opt, XATTR_USER);
530 break;
531 #else
532 case Opt_user_xattr:
533 case Opt_nouser_xattr:
534 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
535 "not supported");
536 break;
537 #endif
538 #ifdef CONFIG_EXT2_FS_POSIX_ACL
539 case Opt_acl:
540 set_opt(sbi->s_mount_opt, POSIX_ACL);
541 break;
542 case Opt_noacl:
543 clear_opt(sbi->s_mount_opt, POSIX_ACL);
544 break;
545 #else
546 case Opt_acl:
547 case Opt_noacl:
548 ext2_msg(sb, KERN_INFO,
549 "(no)acl options not supported");
550 break;
551 #endif
552 case Opt_xip:
553 #ifdef CONFIG_EXT2_FS_XIP
554 set_opt (sbi->s_mount_opt, XIP);
555 #else
556 ext2_msg(sb, KERN_INFO, "xip option not supported");
557 #endif
558 break;
559
560 #if defined(CONFIG_QUOTA)
561 case Opt_quota:
562 case Opt_usrquota:
563 set_opt(sbi->s_mount_opt, USRQUOTA);
564 break;
565
566 case Opt_grpquota:
567 set_opt(sbi->s_mount_opt, GRPQUOTA);
568 break;
569 #else
570 case Opt_quota:
571 case Opt_usrquota:
572 case Opt_grpquota:
573 ext2_msg(sb, KERN_INFO,
574 "quota operations not supported");
575 break;
576 #endif
577
578 case Opt_reservation:
579 set_opt(sbi->s_mount_opt, RESERVATION);
580 ext2_msg(sb, KERN_INFO, "reservations ON");
581 break;
582 case Opt_noreservation:
583 clear_opt(sbi->s_mount_opt, RESERVATION);
584 ext2_msg(sb, KERN_INFO, "reservations OFF");
585 break;
586 case Opt_ignore:
587 break;
588 default:
589 return 0;
590 }
591 }
592 return 1;
593 }
594
595 static int ext2_setup_super (struct super_block * sb,
596 struct ext2_super_block * es,
597 int read_only)
598 {
599 int res = 0;
600 struct ext2_sb_info *sbi = EXT2_SB(sb);
601
602 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
603 ext2_msg(sb, KERN_ERR,
604 "error: revision level too high, "
605 "forcing read-only mode");
606 res = MS_RDONLY;
607 }
608 if (read_only)
609 return res;
610 if (!(sbi->s_mount_state & EXT2_VALID_FS))
611 ext2_msg(sb, KERN_WARNING,
612 "warning: mounting unchecked fs, "
613 "running e2fsck is recommended");
614 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
615 ext2_msg(sb, KERN_WARNING,
616 "warning: mounting fs with errors, "
617 "running e2fsck is recommended");
618 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
619 le16_to_cpu(es->s_mnt_count) >=
620 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
621 ext2_msg(sb, KERN_WARNING,
622 "warning: maximal mount count reached, "
623 "running e2fsck is recommended");
624 else if (le32_to_cpu(es->s_checkinterval) &&
625 (le32_to_cpu(es->s_lastcheck) +
626 le32_to_cpu(es->s_checkinterval) <= get_seconds()))
627 ext2_msg(sb, KERN_WARNING,
628 "warning: checktime reached, "
629 "running e2fsck is recommended");
630 if (!le16_to_cpu(es->s_max_mnt_count))
631 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
632 le16_add_cpu(&es->s_mnt_count, 1);
633 if (test_opt (sb, DEBUG))
634 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
635 "bpg=%lu, ipg=%lu, mo=%04lx]",
636 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
637 sbi->s_frag_size,
638 sbi->s_groups_count,
639 EXT2_BLOCKS_PER_GROUP(sb),
640 EXT2_INODES_PER_GROUP(sb),
641 sbi->s_mount_opt);
642 return res;
643 }
644
645 static int ext2_check_descriptors(struct super_block *sb)
646 {
647 int i;
648 struct ext2_sb_info *sbi = EXT2_SB(sb);
649
650 ext2_debug ("Checking group descriptors");
651
652 for (i = 0; i < sbi->s_groups_count; i++) {
653 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
654 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
655 ext2_fsblk_t last_block;
656
657 if (i == sbi->s_groups_count - 1)
658 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
659 else
660 last_block = first_block +
661 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
662
663 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
664 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
665 {
666 ext2_error (sb, "ext2_check_descriptors",
667 "Block bitmap for group %d"
668 " not in group (block %lu)!",
669 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
670 return 0;
671 }
672 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
673 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
674 {
675 ext2_error (sb, "ext2_check_descriptors",
676 "Inode bitmap for group %d"
677 " not in group (block %lu)!",
678 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
679 return 0;
680 }
681 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
682 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
683 last_block)
684 {
685 ext2_error (sb, "ext2_check_descriptors",
686 "Inode table for group %d"
687 " not in group (block %lu)!",
688 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
689 return 0;
690 }
691 }
692 return 1;
693 }
694
695 /*
696 * Maximal file size. There is a direct, and {,double-,triple-}indirect
697 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
698 * We need to be 1 filesystem block less than the 2^32 sector limit.
699 */
700 static loff_t ext2_max_size(int bits)
701 {
702 loff_t res = EXT2_NDIR_BLOCKS;
703 int meta_blocks;
704 loff_t upper_limit;
705
706 /* This is calculated to be the largest file size for a
707 * dense, file such that the total number of
708 * sectors in the file, including data and all indirect blocks,
709 * does not exceed 2^32 -1
710 * __u32 i_blocks representing the total number of
711 * 512 bytes blocks of the file
712 */
713 upper_limit = (1LL << 32) - 1;
714
715 /* total blocks in file system block size */
716 upper_limit >>= (bits - 9);
717
718
719 /* indirect blocks */
720 meta_blocks = 1;
721 /* double indirect blocks */
722 meta_blocks += 1 + (1LL << (bits-2));
723 /* tripple indirect blocks */
724 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
725
726 upper_limit -= meta_blocks;
727 upper_limit <<= bits;
728
729 res += 1LL << (bits-2);
730 res += 1LL << (2*(bits-2));
731 res += 1LL << (3*(bits-2));
732 res <<= bits;
733 if (res > upper_limit)
734 res = upper_limit;
735
736 if (res > MAX_LFS_FILESIZE)
737 res = MAX_LFS_FILESIZE;
738
739 return res;
740 }
741
742 static unsigned long descriptor_loc(struct super_block *sb,
743 unsigned long logic_sb_block,
744 int nr)
745 {
746 struct ext2_sb_info *sbi = EXT2_SB(sb);
747 unsigned long bg, first_meta_bg;
748 int has_super = 0;
749
750 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
751
752 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
753 nr < first_meta_bg)
754 return (logic_sb_block + nr + 1);
755 bg = sbi->s_desc_per_block * nr;
756 if (ext2_bg_has_super(sb, bg))
757 has_super = 1;
758
759 return ext2_group_first_block_no(sb, bg) + has_super;
760 }
761
762 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
763 {
764 struct buffer_head * bh;
765 struct ext2_sb_info * sbi;
766 struct ext2_super_block * es;
767 struct inode *root;
768 unsigned long block;
769 unsigned long sb_block = get_sb_block(&data);
770 unsigned long logic_sb_block;
771 unsigned long offset = 0;
772 unsigned long def_mount_opts;
773 long ret = -EINVAL;
774 int blocksize = BLOCK_SIZE;
775 int db_count;
776 int i, j;
777 __le32 features;
778 int err;
779
780 err = -ENOMEM;
781 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
782 if (!sbi)
783 goto failed;
784
785 sbi->s_blockgroup_lock =
786 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
787 if (!sbi->s_blockgroup_lock) {
788 kfree(sbi);
789 goto failed;
790 }
791 sb->s_fs_info = sbi;
792 sbi->s_sb_block = sb_block;
793
794 spin_lock_init(&sbi->s_lock);
795
796 /*
797 * See what the current blocksize for the device is, and
798 * use that as the blocksize. Otherwise (or if the blocksize
799 * is smaller than the default) use the default.
800 * This is important for devices that have a hardware
801 * sectorsize that is larger than the default.
802 */
803 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
804 if (!blocksize) {
805 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
806 goto failed_sbi;
807 }
808
809 /*
810 * If the superblock doesn't start on a hardware sector boundary,
811 * calculate the offset.
812 */
813 if (blocksize != BLOCK_SIZE) {
814 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
815 offset = (sb_block*BLOCK_SIZE) % blocksize;
816 } else {
817 logic_sb_block = sb_block;
818 }
819
820 if (!(bh = sb_bread(sb, logic_sb_block))) {
821 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
822 goto failed_sbi;
823 }
824 /*
825 * Note: s_es must be initialized as soon as possible because
826 * some ext2 macro-instructions depend on its value
827 */
828 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
829 sbi->s_es = es;
830 sb->s_magic = le16_to_cpu(es->s_magic);
831
832 if (sb->s_magic != EXT2_SUPER_MAGIC)
833 goto cantfind_ext2;
834
835 /* Set defaults before we parse the mount options */
836 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
837 if (def_mount_opts & EXT2_DEFM_DEBUG)
838 set_opt(sbi->s_mount_opt, DEBUG);
839 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
840 set_opt(sbi->s_mount_opt, GRPID);
841 if (def_mount_opts & EXT2_DEFM_UID16)
842 set_opt(sbi->s_mount_opt, NO_UID32);
843 #ifdef CONFIG_EXT2_FS_XATTR
844 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
845 set_opt(sbi->s_mount_opt, XATTR_USER);
846 #endif
847 #ifdef CONFIG_EXT2_FS_POSIX_ACL
848 if (def_mount_opts & EXT2_DEFM_ACL)
849 set_opt(sbi->s_mount_opt, POSIX_ACL);
850 #endif
851
852 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
853 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
854 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
855 set_opt(sbi->s_mount_opt, ERRORS_CONT);
856 else
857 set_opt(sbi->s_mount_opt, ERRORS_RO);
858
859 sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
860 sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
861
862 set_opt(sbi->s_mount_opt, RESERVATION);
863
864 if (!parse_options((char *) data, sb))
865 goto failed_mount;
866
867 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
868 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
869 MS_POSIXACL : 0);
870
871 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
872 EXT2_MOUNT_XIP if not */
873
874 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
875 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
876 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
877 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
878 ext2_msg(sb, KERN_WARNING,
879 "warning: feature flags set on rev 0 fs, "
880 "running e2fsck is recommended");
881 /*
882 * Check feature flags regardless of the revision level, since we
883 * previously didn't change the revision level when setting the flags,
884 * so there is a chance incompat flags are set on a rev 0 filesystem.
885 */
886 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
887 if (features) {
888 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
889 "unsupported optional features (%x)",
890 le32_to_cpu(features));
891 goto failed_mount;
892 }
893 if (!(sb->s_flags & MS_RDONLY) &&
894 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
895 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
896 "unsupported optional features (%x)",
897 le32_to_cpu(features));
898 goto failed_mount;
899 }
900
901 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
902
903 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
904 if (!silent)
905 ext2_msg(sb, KERN_ERR,
906 "error: unsupported blocksize for xip");
907 goto failed_mount;
908 }
909
910 /* If the blocksize doesn't match, re-read the thing.. */
911 if (sb->s_blocksize != blocksize) {
912 brelse(bh);
913
914 if (!sb_set_blocksize(sb, blocksize)) {
915 ext2_msg(sb, KERN_ERR,
916 "error: bad blocksize %d", blocksize);
917 goto failed_sbi;
918 }
919
920 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
921 offset = (sb_block*BLOCK_SIZE) % blocksize;
922 bh = sb_bread(sb, logic_sb_block);
923 if(!bh) {
924 ext2_msg(sb, KERN_ERR, "error: couldn't read"
925 "superblock on 2nd try");
926 goto failed_sbi;
927 }
928 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
929 sbi->s_es = es;
930 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
931 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
932 goto failed_mount;
933 }
934 }
935
936 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
937 sb->s_max_links = EXT2_LINK_MAX;
938
939 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
940 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
941 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
942 } else {
943 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
944 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
945 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
946 !is_power_of_2(sbi->s_inode_size) ||
947 (sbi->s_inode_size > blocksize)) {
948 ext2_msg(sb, KERN_ERR,
949 "error: unsupported inode size: %d",
950 sbi->s_inode_size);
951 goto failed_mount;
952 }
953 }
954
955 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
956 le32_to_cpu(es->s_log_frag_size);
957 if (sbi->s_frag_size == 0)
958 goto cantfind_ext2;
959 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
960
961 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
962 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
963 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
964
965 if (EXT2_INODE_SIZE(sb) == 0)
966 goto cantfind_ext2;
967 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
968 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
969 goto cantfind_ext2;
970 sbi->s_itb_per_group = sbi->s_inodes_per_group /
971 sbi->s_inodes_per_block;
972 sbi->s_desc_per_block = sb->s_blocksize /
973 sizeof (struct ext2_group_desc);
974 sbi->s_sbh = bh;
975 sbi->s_mount_state = le16_to_cpu(es->s_state);
976 sbi->s_addr_per_block_bits =
977 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
978 sbi->s_desc_per_block_bits =
979 ilog2 (EXT2_DESC_PER_BLOCK(sb));
980
981 if (sb->s_magic != EXT2_SUPER_MAGIC)
982 goto cantfind_ext2;
983
984 if (sb->s_blocksize != bh->b_size) {
985 if (!silent)
986 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
987 goto failed_mount;
988 }
989
990 if (sb->s_blocksize != sbi->s_frag_size) {
991 ext2_msg(sb, KERN_ERR,
992 "error: fragsize %lu != blocksize %lu"
993 "(not supported yet)",
994 sbi->s_frag_size, sb->s_blocksize);
995 goto failed_mount;
996 }
997
998 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
999 ext2_msg(sb, KERN_ERR,
1000 "error: #blocks per group too big: %lu",
1001 sbi->s_blocks_per_group);
1002 goto failed_mount;
1003 }
1004 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1005 ext2_msg(sb, KERN_ERR,
1006 "error: #fragments per group too big: %lu",
1007 sbi->s_frags_per_group);
1008 goto failed_mount;
1009 }
1010 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1011 ext2_msg(sb, KERN_ERR,
1012 "error: #inodes per group too big: %lu",
1013 sbi->s_inodes_per_group);
1014 goto failed_mount;
1015 }
1016
1017 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1018 goto cantfind_ext2;
1019 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1020 le32_to_cpu(es->s_first_data_block) - 1)
1021 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1022 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1023 EXT2_DESC_PER_BLOCK(sb);
1024 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1025 if (sbi->s_group_desc == NULL) {
1026 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1027 goto failed_mount;
1028 }
1029 bgl_lock_init(sbi->s_blockgroup_lock);
1030 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1031 if (!sbi->s_debts) {
1032 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1033 goto failed_mount_group_desc;
1034 }
1035 for (i = 0; i < db_count; i++) {
1036 block = descriptor_loc(sb, logic_sb_block, i);
1037 sbi->s_group_desc[i] = sb_bread(sb, block);
1038 if (!sbi->s_group_desc[i]) {
1039 for (j = 0; j < i; j++)
1040 brelse (sbi->s_group_desc[j]);
1041 ext2_msg(sb, KERN_ERR,
1042 "error: unable to read group descriptors");
1043 goto failed_mount_group_desc;
1044 }
1045 }
1046 if (!ext2_check_descriptors (sb)) {
1047 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1048 goto failed_mount2;
1049 }
1050 sbi->s_gdb_count = db_count;
1051 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1052 spin_lock_init(&sbi->s_next_gen_lock);
1053
1054 /* per fileystem reservation list head & lock */
1055 spin_lock_init(&sbi->s_rsv_window_lock);
1056 sbi->s_rsv_window_root = RB_ROOT;
1057 /*
1058 * Add a single, static dummy reservation to the start of the
1059 * reservation window list --- it gives us a placeholder for
1060 * append-at-start-of-list which makes the allocation logic
1061 * _much_ simpler.
1062 */
1063 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1064 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1065 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1066 sbi->s_rsv_window_head.rsv_goal_size = 0;
1067 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1068
1069 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1070 ext2_count_free_blocks(sb), GFP_KERNEL);
1071 if (!err) {
1072 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1073 ext2_count_free_inodes(sb), GFP_KERNEL);
1074 }
1075 if (!err) {
1076 err = percpu_counter_init(&sbi->s_dirs_counter,
1077 ext2_count_dirs(sb), GFP_KERNEL);
1078 }
1079 if (err) {
1080 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1081 goto failed_mount3;
1082 }
1083 /*
1084 * set up enough so that it can read an inode
1085 */
1086 sb->s_op = &ext2_sops;
1087 sb->s_export_op = &ext2_export_ops;
1088 sb->s_xattr = ext2_xattr_handlers;
1089
1090 #ifdef CONFIG_QUOTA
1091 sb->dq_op = &dquot_operations;
1092 sb->s_qcop = &dquot_quotactl_ops;
1093 #endif
1094
1095 root = ext2_iget(sb, EXT2_ROOT_INO);
1096 if (IS_ERR(root)) {
1097 ret = PTR_ERR(root);
1098 goto failed_mount3;
1099 }
1100 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1101 iput(root);
1102 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1103 goto failed_mount3;
1104 }
1105
1106 sb->s_root = d_make_root(root);
1107 if (!sb->s_root) {
1108 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1109 ret = -ENOMEM;
1110 goto failed_mount3;
1111 }
1112 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1113 ext2_msg(sb, KERN_WARNING,
1114 "warning: mounting ext3 filesystem as ext2");
1115 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1116 sb->s_flags |= MS_RDONLY;
1117 ext2_write_super(sb);
1118 return 0;
1119
1120 cantfind_ext2:
1121 if (!silent)
1122 ext2_msg(sb, KERN_ERR,
1123 "error: can't find an ext2 filesystem on dev %s.",
1124 sb->s_id);
1125 goto failed_mount;
1126 failed_mount3:
1127 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1128 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1129 percpu_counter_destroy(&sbi->s_dirs_counter);
1130 failed_mount2:
1131 for (i = 0; i < db_count; i++)
1132 brelse(sbi->s_group_desc[i]);
1133 failed_mount_group_desc:
1134 kfree(sbi->s_group_desc);
1135 kfree(sbi->s_debts);
1136 failed_mount:
1137 brelse(bh);
1138 failed_sbi:
1139 sb->s_fs_info = NULL;
1140 kfree(sbi->s_blockgroup_lock);
1141 kfree(sbi);
1142 failed:
1143 return ret;
1144 }
1145
1146 static void ext2_clear_super_error(struct super_block *sb)
1147 {
1148 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1149
1150 if (buffer_write_io_error(sbh)) {
1151 /*
1152 * Oh, dear. A previous attempt to write the
1153 * superblock failed. This could happen because the
1154 * USB device was yanked out. Or it could happen to
1155 * be a transient write error and maybe the block will
1156 * be remapped. Nothing we can do but to retry the
1157 * write and hope for the best.
1158 */
1159 ext2_msg(sb, KERN_ERR,
1160 "previous I/O error to superblock detected\n");
1161 clear_buffer_write_io_error(sbh);
1162 set_buffer_uptodate(sbh);
1163 }
1164 }
1165
1166 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1167 int wait)
1168 {
1169 ext2_clear_super_error(sb);
1170 spin_lock(&EXT2_SB(sb)->s_lock);
1171 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1172 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1173 es->s_wtime = cpu_to_le32(get_seconds());
1174 /* unlock before we do IO */
1175 spin_unlock(&EXT2_SB(sb)->s_lock);
1176 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1177 if (wait)
1178 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1179 }
1180
1181 /*
1182 * In the second extended file system, it is not necessary to
1183 * write the super block since we use a mapping of the
1184 * disk super block in a buffer.
1185 *
1186 * However, this function is still used to set the fs valid
1187 * flags to 0. We need to set this flag to 0 since the fs
1188 * may have been checked while mounted and e2fsck may have
1189 * set s_state to EXT2_VALID_FS after some corrections.
1190 */
1191 static int ext2_sync_fs(struct super_block *sb, int wait)
1192 {
1193 struct ext2_sb_info *sbi = EXT2_SB(sb);
1194 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1195
1196 /*
1197 * Write quota structures to quota file, sync_blockdev() will write
1198 * them to disk later
1199 */
1200 dquot_writeback_dquots(sb, -1);
1201
1202 spin_lock(&sbi->s_lock);
1203 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1204 ext2_debug("setting valid to 0\n");
1205 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1206 }
1207 spin_unlock(&sbi->s_lock);
1208 ext2_sync_super(sb, es, wait);
1209 return 0;
1210 }
1211
1212 static int ext2_freeze(struct super_block *sb)
1213 {
1214 struct ext2_sb_info *sbi = EXT2_SB(sb);
1215
1216 /*
1217 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1218 * because we have unattached inodes and thus filesystem is not fully
1219 * consistent.
1220 */
1221 if (atomic_long_read(&sb->s_remove_count)) {
1222 ext2_sync_fs(sb, 1);
1223 return 0;
1224 }
1225 /* Set EXT2_FS_VALID flag */
1226 spin_lock(&sbi->s_lock);
1227 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1228 spin_unlock(&sbi->s_lock);
1229 ext2_sync_super(sb, sbi->s_es, 1);
1230
1231 return 0;
1232 }
1233
1234 static int ext2_unfreeze(struct super_block *sb)
1235 {
1236 /* Just write sb to clear EXT2_VALID_FS flag */
1237 ext2_write_super(sb);
1238
1239 return 0;
1240 }
1241
1242 void ext2_write_super(struct super_block *sb)
1243 {
1244 if (!(sb->s_flags & MS_RDONLY))
1245 ext2_sync_fs(sb, 1);
1246 }
1247
1248 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1249 {
1250 struct ext2_sb_info * sbi = EXT2_SB(sb);
1251 struct ext2_super_block * es;
1252 unsigned long old_mount_opt = sbi->s_mount_opt;
1253 struct ext2_mount_options old_opts;
1254 unsigned long old_sb_flags;
1255 int err;
1256
1257 sync_filesystem(sb);
1258 spin_lock(&sbi->s_lock);
1259
1260 /* Store the old options */
1261 old_sb_flags = sb->s_flags;
1262 old_opts.s_mount_opt = sbi->s_mount_opt;
1263 old_opts.s_resuid = sbi->s_resuid;
1264 old_opts.s_resgid = sbi->s_resgid;
1265
1266 /*
1267 * Allow the "check" option to be passed as a remount option.
1268 */
1269 if (!parse_options(data, sb)) {
1270 err = -EINVAL;
1271 goto restore_opts;
1272 }
1273
1274 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1275 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1276
1277 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1278 EXT2_MOUNT_XIP if not */
1279
1280 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1281 ext2_msg(sb, KERN_WARNING,
1282 "warning: unsupported blocksize for xip");
1283 err = -EINVAL;
1284 goto restore_opts;
1285 }
1286
1287 es = sbi->s_es;
1288 if ((sbi->s_mount_opt ^ old_mount_opt) & EXT2_MOUNT_XIP) {
1289 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1290 "xip flag with busy inodes while remounting");
1291 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1292 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1293 }
1294 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1295 spin_unlock(&sbi->s_lock);
1296 return 0;
1297 }
1298 if (*flags & MS_RDONLY) {
1299 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1300 !(sbi->s_mount_state & EXT2_VALID_FS)) {
1301 spin_unlock(&sbi->s_lock);
1302 return 0;
1303 }
1304
1305 /*
1306 * OK, we are remounting a valid rw partition rdonly, so set
1307 * the rdonly flag and then mark the partition as valid again.
1308 */
1309 es->s_state = cpu_to_le16(sbi->s_mount_state);
1310 es->s_mtime = cpu_to_le32(get_seconds());
1311 spin_unlock(&sbi->s_lock);
1312
1313 err = dquot_suspend(sb, -1);
1314 if (err < 0) {
1315 spin_lock(&sbi->s_lock);
1316 goto restore_opts;
1317 }
1318
1319 ext2_sync_super(sb, es, 1);
1320 } else {
1321 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1322 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1323 if (ret) {
1324 ext2_msg(sb, KERN_WARNING,
1325 "warning: couldn't remount RDWR because of "
1326 "unsupported optional features (%x).",
1327 le32_to_cpu(ret));
1328 err = -EROFS;
1329 goto restore_opts;
1330 }
1331 /*
1332 * Mounting a RDONLY partition read-write, so reread and
1333 * store the current valid flag. (It may have been changed
1334 * by e2fsck since we originally mounted the partition.)
1335 */
1336 sbi->s_mount_state = le16_to_cpu(es->s_state);
1337 if (!ext2_setup_super (sb, es, 0))
1338 sb->s_flags &= ~MS_RDONLY;
1339 spin_unlock(&sbi->s_lock);
1340
1341 ext2_write_super(sb);
1342
1343 dquot_resume(sb, -1);
1344 }
1345
1346 return 0;
1347 restore_opts:
1348 sbi->s_mount_opt = old_opts.s_mount_opt;
1349 sbi->s_resuid = old_opts.s_resuid;
1350 sbi->s_resgid = old_opts.s_resgid;
1351 sb->s_flags = old_sb_flags;
1352 spin_unlock(&sbi->s_lock);
1353 return err;
1354 }
1355
1356 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1357 {
1358 struct super_block *sb = dentry->d_sb;
1359 struct ext2_sb_info *sbi = EXT2_SB(sb);
1360 struct ext2_super_block *es = sbi->s_es;
1361 u64 fsid;
1362
1363 spin_lock(&sbi->s_lock);
1364
1365 if (test_opt (sb, MINIX_DF))
1366 sbi->s_overhead_last = 0;
1367 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1368 unsigned long i, overhead = 0;
1369 smp_rmb();
1370
1371 /*
1372 * Compute the overhead (FS structures). This is constant
1373 * for a given filesystem unless the number of block groups
1374 * changes so we cache the previous value until it does.
1375 */
1376
1377 /*
1378 * All of the blocks before first_data_block are
1379 * overhead
1380 */
1381 overhead = le32_to_cpu(es->s_first_data_block);
1382
1383 /*
1384 * Add the overhead attributed to the superblock and
1385 * block group descriptors. If the sparse superblocks
1386 * feature is turned on, then not all groups have this.
1387 */
1388 for (i = 0; i < sbi->s_groups_count; i++)
1389 overhead += ext2_bg_has_super(sb, i) +
1390 ext2_bg_num_gdb(sb, i);
1391
1392 /*
1393 * Every block group has an inode bitmap, a block
1394 * bitmap, and an inode table.
1395 */
1396 overhead += (sbi->s_groups_count *
1397 (2 + sbi->s_itb_per_group));
1398 sbi->s_overhead_last = overhead;
1399 smp_wmb();
1400 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1401 }
1402
1403 buf->f_type = EXT2_SUPER_MAGIC;
1404 buf->f_bsize = sb->s_blocksize;
1405 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1406 buf->f_bfree = ext2_count_free_blocks(sb);
1407 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1408 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1409 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1410 buf->f_bavail = 0;
1411 buf->f_files = le32_to_cpu(es->s_inodes_count);
1412 buf->f_ffree = ext2_count_free_inodes(sb);
1413 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1414 buf->f_namelen = EXT2_NAME_LEN;
1415 fsid = le64_to_cpup((void *)es->s_uuid) ^
1416 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1417 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1418 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1419 spin_unlock(&sbi->s_lock);
1420 return 0;
1421 }
1422
1423 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1424 int flags, const char *dev_name, void *data)
1425 {
1426 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1427 }
1428
1429 #ifdef CONFIG_QUOTA
1430
1431 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1432 * acquiring the locks... As quota files are never truncated and quota code
1433 * itself serializes the operations (and no one else should touch the files)
1434 * we don't have to be afraid of races */
1435 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1436 size_t len, loff_t off)
1437 {
1438 struct inode *inode = sb_dqopt(sb)->files[type];
1439 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1440 int err = 0;
1441 int offset = off & (sb->s_blocksize - 1);
1442 int tocopy;
1443 size_t toread;
1444 struct buffer_head tmp_bh;
1445 struct buffer_head *bh;
1446 loff_t i_size = i_size_read(inode);
1447
1448 if (off > i_size)
1449 return 0;
1450 if (off+len > i_size)
1451 len = i_size-off;
1452 toread = len;
1453 while (toread > 0) {
1454 tocopy = sb->s_blocksize - offset < toread ?
1455 sb->s_blocksize - offset : toread;
1456
1457 tmp_bh.b_state = 0;
1458 tmp_bh.b_size = sb->s_blocksize;
1459 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1460 if (err < 0)
1461 return err;
1462 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1463 memset(data, 0, tocopy);
1464 else {
1465 bh = sb_bread(sb, tmp_bh.b_blocknr);
1466 if (!bh)
1467 return -EIO;
1468 memcpy(data, bh->b_data+offset, tocopy);
1469 brelse(bh);
1470 }
1471 offset = 0;
1472 toread -= tocopy;
1473 data += tocopy;
1474 blk++;
1475 }
1476 return len;
1477 }
1478
1479 /* Write to quotafile */
1480 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1481 const char *data, size_t len, loff_t off)
1482 {
1483 struct inode *inode = sb_dqopt(sb)->files[type];
1484 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1485 int err = 0;
1486 int offset = off & (sb->s_blocksize - 1);
1487 int tocopy;
1488 size_t towrite = len;
1489 struct buffer_head tmp_bh;
1490 struct buffer_head *bh;
1491
1492 while (towrite > 0) {
1493 tocopy = sb->s_blocksize - offset < towrite ?
1494 sb->s_blocksize - offset : towrite;
1495
1496 tmp_bh.b_state = 0;
1497 tmp_bh.b_size = sb->s_blocksize;
1498 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1499 if (err < 0)
1500 goto out;
1501 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1502 bh = sb_bread(sb, tmp_bh.b_blocknr);
1503 else
1504 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1505 if (unlikely(!bh)) {
1506 err = -EIO;
1507 goto out;
1508 }
1509 lock_buffer(bh);
1510 memcpy(bh->b_data+offset, data, tocopy);
1511 flush_dcache_page(bh->b_page);
1512 set_buffer_uptodate(bh);
1513 mark_buffer_dirty(bh);
1514 unlock_buffer(bh);
1515 brelse(bh);
1516 offset = 0;
1517 towrite -= tocopy;
1518 data += tocopy;
1519 blk++;
1520 }
1521 out:
1522 if (len == towrite)
1523 return err;
1524 if (inode->i_size < off+len-towrite)
1525 i_size_write(inode, off+len-towrite);
1526 inode->i_version++;
1527 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1528 mark_inode_dirty(inode);
1529 return len - towrite;
1530 }
1531
1532 #endif
1533
1534 static struct file_system_type ext2_fs_type = {
1535 .owner = THIS_MODULE,
1536 .name = "ext2",
1537 .mount = ext2_mount,
1538 .kill_sb = kill_block_super,
1539 .fs_flags = FS_REQUIRES_DEV,
1540 };
1541 MODULE_ALIAS_FS("ext2");
1542
1543 static int __init init_ext2_fs(void)
1544 {
1545 int err = init_ext2_xattr();
1546 if (err)
1547 return err;
1548 err = init_inodecache();
1549 if (err)
1550 goto out1;
1551 err = register_filesystem(&ext2_fs_type);
1552 if (err)
1553 goto out;
1554 return 0;
1555 out:
1556 destroy_inodecache();
1557 out1:
1558 exit_ext2_xattr();
1559 return err;
1560 }
1561
1562 static void __exit exit_ext2_fs(void)
1563 {
1564 unregister_filesystem(&ext2_fs_type);
1565 destroy_inodecache();
1566 exit_ext2_xattr();
1567 }
1568
1569 MODULE_AUTHOR("Remy Card and others");
1570 MODULE_DESCRIPTION("Second Extended Filesystem");
1571 MODULE_LICENSE("GPL");
1572 module_init(init_ext2_fs)
1573 module_exit(exit_ext2_fs)
Linux kernel - Deliverables
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