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