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Staging: wlags49_h25: Makefile: remove unneeded stuff
[zen-stable.git] / fs / ext2 / super.c
blob1dd62ed35b8511efece6cd6733eb960185f9ec28
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 if (sb->s_dirt)
134 ext2_write_super(sb);
135
136 ext2_xattr_put_super(sb);
137 if (!(sb->s_flags & MS_RDONLY)) {
138 struct ext2_super_block *es = sbi->s_es;
139
140 spin_lock(&sbi->s_lock);
141 es->s_state = cpu_to_le16(sbi->s_mount_state);
142 spin_unlock(&sbi->s_lock);
143 ext2_sync_super(sb, es, 1);
144 }
145 db_count = sbi->s_gdb_count;
146 for (i = 0; i < db_count; i++)
147 if (sbi->s_group_desc[i])
148 brelse (sbi->s_group_desc[i]);
149 kfree(sbi->s_group_desc);
150 kfree(sbi->s_debts);
151 percpu_counter_destroy(&sbi->s_freeblocks_counter);
152 percpu_counter_destroy(&sbi->s_freeinodes_counter);
153 percpu_counter_destroy(&sbi->s_dirs_counter);
154 brelse (sbi->s_sbh);
155 sb->s_fs_info = NULL;
156 kfree(sbi->s_blockgroup_lock);
157 kfree(sbi);
158 }
159
160 static struct kmem_cache * ext2_inode_cachep;
161
162 static struct inode *ext2_alloc_inode(struct super_block *sb)
163 {
164 struct ext2_inode_info *ei;
165 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
166 if (!ei)
167 return NULL;
168 ei->i_block_alloc_info = NULL;
169 ei->vfs_inode.i_version = 1;
170 return &ei->vfs_inode;
171 }
172
173 static void ext2_i_callback(struct rcu_head *head)
174 {
175 struct inode *inode = container_of(head, struct inode, i_rcu);
176 INIT_LIST_HEAD(&inode->i_dentry);
177 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
178 }
179
180 static void ext2_destroy_inode(struct inode *inode)
181 {
182 call_rcu(&inode->i_rcu, ext2_i_callback);
183 }
184
185 static void init_once(void *foo)
186 {
187 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
188
189 rwlock_init(&ei->i_meta_lock);
190 #ifdef CONFIG_EXT2_FS_XATTR
191 init_rwsem(&ei->xattr_sem);
192 #endif
193 mutex_init(&ei->truncate_mutex);
194 inode_init_once(&ei->vfs_inode);
195 }
196
197 static int init_inodecache(void)
198 {
199 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
200 sizeof(struct ext2_inode_info),
201 0, (SLAB_RECLAIM_ACCOUNT|
202 SLAB_MEM_SPREAD),
203 init_once);
204 if (ext2_inode_cachep == NULL)
205 return -ENOMEM;
206 return 0;
207 }
208
209 static void destroy_inodecache(void)
210 {
211 kmem_cache_destroy(ext2_inode_cachep);
212 }
213
214 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
215 {
216 struct super_block *sb = vfs->mnt_sb;
217 struct ext2_sb_info *sbi = EXT2_SB(sb);
218 struct ext2_super_block *es = sbi->s_es;
219 unsigned long def_mount_opts;
220
221 spin_lock(&sbi->s_lock);
222 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
223
224 if (sbi->s_sb_block != 1)
225 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
226 if (test_opt(sb, MINIX_DF))
227 seq_puts(seq, ",minixdf");
228 if (test_opt(sb, GRPID))
229 seq_puts(seq, ",grpid");
230 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
231 seq_puts(seq, ",nogrpid");
232 if (sbi->s_resuid != EXT2_DEF_RESUID ||
233 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
234 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
235 }
236 if (sbi->s_resgid != EXT2_DEF_RESGID ||
237 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
238 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
239 }
240 if (test_opt(sb, ERRORS_RO)) {
241 int def_errors = le16_to_cpu(es->s_errors);
242
243 if (def_errors == EXT2_ERRORS_PANIC ||
244 def_errors == EXT2_ERRORS_CONTINUE) {
245 seq_puts(seq, ",errors=remount-ro");
246 }
247 }
248 if (test_opt(sb, ERRORS_CONT))
249 seq_puts(seq, ",errors=continue");
250 if (test_opt(sb, ERRORS_PANIC))
251 seq_puts(seq, ",errors=panic");
252 if (test_opt(sb, NO_UID32))
253 seq_puts(seq, ",nouid32");
254 if (test_opt(sb, DEBUG))
255 seq_puts(seq, ",debug");
256 if (test_opt(sb, OLDALLOC))
257 seq_puts(seq, ",oldalloc");
258
259 #ifdef CONFIG_EXT2_FS_XATTR
260 if (test_opt(sb, XATTR_USER))
261 seq_puts(seq, ",user_xattr");
262 if (!test_opt(sb, XATTR_USER) &&
263 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
264 seq_puts(seq, ",nouser_xattr");
265 }
266 #endif
267
268 #ifdef CONFIG_EXT2_FS_POSIX_ACL
269 if (test_opt(sb, POSIX_ACL))
270 seq_puts(seq, ",acl");
271 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
272 seq_puts(seq, ",noacl");
273 #endif
274
275 if (test_opt(sb, NOBH))
276 seq_puts(seq, ",nobh");
277
278 #if defined(CONFIG_QUOTA)
279 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
280 seq_puts(seq, ",usrquota");
281
282 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
283 seq_puts(seq, ",grpquota");
284 #endif
285
286 #if defined(CONFIG_EXT2_FS_XIP)
287 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
288 seq_puts(seq, ",xip");
289 #endif
290
291 if (!test_opt(sb, RESERVATION))
292 seq_puts(seq, ",noreservation");
293
294 spin_unlock(&sbi->s_lock);
295 return 0;
296 }
297
298 #ifdef CONFIG_QUOTA
299 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
300 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
301 #endif
302
303 static const struct super_operations ext2_sops = {
304 .alloc_inode = ext2_alloc_inode,
305 .destroy_inode = ext2_destroy_inode,
306 .write_inode = ext2_write_inode,
307 .evict_inode = ext2_evict_inode,
308 .put_super = ext2_put_super,
309 .write_super = ext2_write_super,
310 .sync_fs = ext2_sync_fs,
311 .statfs = ext2_statfs,
312 .remount_fs = ext2_remount,
313 .show_options = ext2_show_options,
314 #ifdef CONFIG_QUOTA
315 .quota_read = ext2_quota_read,
316 .quota_write = ext2_quota_write,
317 #endif
318 };
319
320 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
321 u64 ino, u32 generation)
322 {
323 struct inode *inode;
324
325 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
326 return ERR_PTR(-ESTALE);
327 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
328 return ERR_PTR(-ESTALE);
329
330 /* iget isn't really right if the inode is currently unallocated!!
331 * ext2_read_inode currently does appropriate checks, but
332 * it might be "neater" to call ext2_get_inode first and check
333 * if the inode is valid.....
334 */
335 inode = ext2_iget(sb, ino);
336 if (IS_ERR(inode))
337 return ERR_CAST(inode);
338 if (generation && inode->i_generation != generation) {
339 /* we didn't find the right inode.. */
340 iput(inode);
341 return ERR_PTR(-ESTALE);
342 }
343 return inode;
344 }
345
346 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
347 int fh_len, int fh_type)
348 {
349 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
350 ext2_nfs_get_inode);
351 }
352
353 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
354 int fh_len, int fh_type)
355 {
356 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
357 ext2_nfs_get_inode);
358 }
359
360 /* Yes, most of these are left as NULL!!
361 * A NULL value implies the default, which works with ext2-like file
362 * systems, but can be improved upon.
363 * Currently only get_parent is required.
364 */
365 static const struct export_operations ext2_export_ops = {
366 .fh_to_dentry = ext2_fh_to_dentry,
367 .fh_to_parent = ext2_fh_to_parent,
368 .get_parent = ext2_get_parent,
369 };
370
371 static unsigned long get_sb_block(void **data)
372 {
373 unsigned long sb_block;
374 char *options = (char *) *data;
375
376 if (!options || strncmp(options, "sb=", 3) != 0)
377 return 1; /* Default location */
378 options += 3;
379 sb_block = simple_strtoul(options, &options, 0);
380 if (*options && *options != ',') {
381 printk("EXT2-fs: Invalid sb specification: %s\n",
382 (char *) *data);
383 return 1;
384 }
385 if (*options == ',')
386 options++;
387 *data = (void *) options;
388 return sb_block;
389 }
390
391 enum {
392 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
393 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
394 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
395 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
396 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
397 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
398 };
399
400 static const match_table_t tokens = {
401 {Opt_bsd_df, "bsddf"},
402 {Opt_minix_df, "minixdf"},
403 {Opt_grpid, "grpid"},
404 {Opt_grpid, "bsdgroups"},
405 {Opt_nogrpid, "nogrpid"},
406 {Opt_nogrpid, "sysvgroups"},
407 {Opt_resgid, "resgid=%u"},
408 {Opt_resuid, "resuid=%u"},
409 {Opt_sb, "sb=%u"},
410 {Opt_err_cont, "errors=continue"},
411 {Opt_err_panic, "errors=panic"},
412 {Opt_err_ro, "errors=remount-ro"},
413 {Opt_nouid32, "nouid32"},
414 {Opt_nocheck, "check=none"},
415 {Opt_nocheck, "nocheck"},
416 {Opt_debug, "debug"},
417 {Opt_oldalloc, "oldalloc"},
418 {Opt_orlov, "orlov"},
419 {Opt_nobh, "nobh"},
420 {Opt_user_xattr, "user_xattr"},
421 {Opt_nouser_xattr, "nouser_xattr"},
422 {Opt_acl, "acl"},
423 {Opt_noacl, "noacl"},
424 {Opt_xip, "xip"},
425 {Opt_grpquota, "grpquota"},
426 {Opt_ignore, "noquota"},
427 {Opt_quota, "quota"},
428 {Opt_usrquota, "usrquota"},
429 {Opt_reservation, "reservation"},
430 {Opt_noreservation, "noreservation"},
431 {Opt_err, NULL}
432 };
433
434 static int parse_options(char *options, struct super_block *sb)
435 {
436 char *p;
437 struct ext2_sb_info *sbi = EXT2_SB(sb);
438 substring_t args[MAX_OPT_ARGS];
439 int option;
440
441 if (!options)
442 return 1;
443
444 while ((p = strsep (&options, ",")) != NULL) {
445 int token;
446 if (!*p)
447 continue;
448
449 token = match_token(p, tokens, args);
450 switch (token) {
451 case Opt_bsd_df:
452 clear_opt (sbi->s_mount_opt, MINIX_DF);
453 break;
454 case Opt_minix_df:
455 set_opt (sbi->s_mount_opt, MINIX_DF);
456 break;
457 case Opt_grpid:
458 set_opt (sbi->s_mount_opt, GRPID);
459 break;
460 case Opt_nogrpid:
461 clear_opt (sbi->s_mount_opt, GRPID);
462 break;
463 case Opt_resuid:
464 if (match_int(&args[0], &option))
465 return 0;
466 sbi->s_resuid = option;
467 break;
468 case Opt_resgid:
469 if (match_int(&args[0], &option))
470 return 0;
471 sbi->s_resgid = option;
472 break;
473 case Opt_sb:
474 /* handled by get_sb_block() instead of here */
475 /* *sb_block = match_int(&args[0]); */
476 break;
477 case Opt_err_panic:
478 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
479 clear_opt (sbi->s_mount_opt, ERRORS_RO);
480 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
481 break;
482 case Opt_err_ro:
483 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
484 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
485 set_opt (sbi->s_mount_opt, ERRORS_RO);
486 break;
487 case Opt_err_cont:
488 clear_opt (sbi->s_mount_opt, ERRORS_RO);
489 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
490 set_opt (sbi->s_mount_opt, ERRORS_CONT);
491 break;
492 case Opt_nouid32:
493 set_opt (sbi->s_mount_opt, NO_UID32);
494 break;
495 case Opt_nocheck:
496 clear_opt (sbi->s_mount_opt, CHECK);
497 break;
498 case Opt_debug:
499 set_opt (sbi->s_mount_opt, DEBUG);
500 break;
501 case Opt_oldalloc:
502 set_opt (sbi->s_mount_opt, OLDALLOC);
503 break;
504 case Opt_orlov:
505 clear_opt (sbi->s_mount_opt, OLDALLOC);
506 break;
507 case Opt_nobh:
508 set_opt (sbi->s_mount_opt, NOBH);
509 break;
510 #ifdef CONFIG_EXT2_FS_XATTR
511 case Opt_user_xattr:
512 set_opt (sbi->s_mount_opt, XATTR_USER);
513 break;
514 case Opt_nouser_xattr:
515 clear_opt (sbi->s_mount_opt, XATTR_USER);
516 break;
517 #else
518 case Opt_user_xattr:
519 case Opt_nouser_xattr:
520 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
521 "not supported");
522 break;
523 #endif
524 #ifdef CONFIG_EXT2_FS_POSIX_ACL
525 case Opt_acl:
526 set_opt(sbi->s_mount_opt, POSIX_ACL);
527 break;
528 case Opt_noacl:
529 clear_opt(sbi->s_mount_opt, POSIX_ACL);
530 break;
531 #else
532 case Opt_acl:
533 case Opt_noacl:
534 ext2_msg(sb, KERN_INFO,
535 "(no)acl options not supported");
536 break;
537 #endif
538 case Opt_xip:
539 #ifdef CONFIG_EXT2_FS_XIP
540 set_opt (sbi->s_mount_opt, XIP);
541 #else
542 ext2_msg(sb, KERN_INFO, "xip option not supported");
543 #endif
544 break;
545
546 #if defined(CONFIG_QUOTA)
547 case Opt_quota:
548 case Opt_usrquota:
549 set_opt(sbi->s_mount_opt, USRQUOTA);
550 break;
551
552 case Opt_grpquota:
553 set_opt(sbi->s_mount_opt, GRPQUOTA);
554 break;
555 #else
556 case Opt_quota:
557 case Opt_usrquota:
558 case Opt_grpquota:
559 ext2_msg(sb, KERN_INFO,
560 "quota operations not supported");
561 break;
562 #endif
563
564 case Opt_reservation:
565 set_opt(sbi->s_mount_opt, RESERVATION);
566 ext2_msg(sb, KERN_INFO, "reservations ON");
567 break;
568 case Opt_noreservation:
569 clear_opt(sbi->s_mount_opt, RESERVATION);
570 ext2_msg(sb, KERN_INFO, "reservations OFF");
571 break;
572 case Opt_ignore:
573 break;
574 default:
575 return 0;
576 }
577 }
578 return 1;
579 }
580
581 static int ext2_setup_super (struct super_block * sb,
582 struct ext2_super_block * es,
583 int read_only)
584 {
585 int res = 0;
586 struct ext2_sb_info *sbi = EXT2_SB(sb);
587
588 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
589 ext2_msg(sb, KERN_ERR,
590 "error: revision level too high, "
591 "forcing read-only mode");
592 res = MS_RDONLY;
593 }
594 if (read_only)
595 return res;
596 if (!(sbi->s_mount_state & EXT2_VALID_FS))
597 ext2_msg(sb, KERN_WARNING,
598 "warning: mounting unchecked fs, "
599 "running e2fsck is recommended");
600 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
601 ext2_msg(sb, KERN_WARNING,
602 "warning: mounting fs with errors, "
603 "running e2fsck is recommended");
604 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
605 le16_to_cpu(es->s_mnt_count) >=
606 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
607 ext2_msg(sb, KERN_WARNING,
608 "warning: maximal mount count reached, "
609 "running e2fsck is recommended");
610 else if (le32_to_cpu(es->s_checkinterval) &&
611 (le32_to_cpu(es->s_lastcheck) +
612 le32_to_cpu(es->s_checkinterval) <= get_seconds()))
613 ext2_msg(sb, KERN_WARNING,
614 "warning: checktime reached, "
615 "running e2fsck is recommended");
616 if (!le16_to_cpu(es->s_max_mnt_count))
617 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
618 le16_add_cpu(&es->s_mnt_count, 1);
619 if (test_opt (sb, DEBUG))
620 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
621 "bpg=%lu, ipg=%lu, mo=%04lx]",
622 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
623 sbi->s_frag_size,
624 sbi->s_groups_count,
625 EXT2_BLOCKS_PER_GROUP(sb),
626 EXT2_INODES_PER_GROUP(sb),
627 sbi->s_mount_opt);
628 return res;
629 }
630
631 static int ext2_check_descriptors(struct super_block *sb)
632 {
633 int i;
634 struct ext2_sb_info *sbi = EXT2_SB(sb);
635
636 ext2_debug ("Checking group descriptors");
637
638 for (i = 0; i < sbi->s_groups_count; i++) {
639 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
640 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
641 ext2_fsblk_t last_block;
642
643 if (i == sbi->s_groups_count - 1)
644 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
645 else
646 last_block = first_block +
647 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
648
649 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
650 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
651 {
652 ext2_error (sb, "ext2_check_descriptors",
653 "Block bitmap for group %d"
654 " not in group (block %lu)!",
655 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
656 return 0;
657 }
658 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
659 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
660 {
661 ext2_error (sb, "ext2_check_descriptors",
662 "Inode bitmap for group %d"
663 " not in group (block %lu)!",
664 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
665 return 0;
666 }
667 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
668 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
669 last_block)
670 {
671 ext2_error (sb, "ext2_check_descriptors",
672 "Inode table for group %d"
673 " not in group (block %lu)!",
674 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
675 return 0;
676 }
677 }
678 return 1;
679 }
680
681 /*
682 * Maximal file size. There is a direct, and {,double-,triple-}indirect
683 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
684 * We need to be 1 filesystem block less than the 2^32 sector limit.
685 */
686 static loff_t ext2_max_size(int bits)
687 {
688 loff_t res = EXT2_NDIR_BLOCKS;
689 int meta_blocks;
690 loff_t upper_limit;
691
692 /* This is calculated to be the largest file size for a
693 * dense, file such that the total number of
694 * sectors in the file, including data and all indirect blocks,
695 * does not exceed 2^32 -1
696 * __u32 i_blocks representing the total number of
697 * 512 bytes blocks of the file
698 */
699 upper_limit = (1LL << 32) - 1;
700
701 /* total blocks in file system block size */
702 upper_limit >>= (bits - 9);
703
704
705 /* indirect blocks */
706 meta_blocks = 1;
707 /* double indirect blocks */
708 meta_blocks += 1 + (1LL << (bits-2));
709 /* tripple indirect blocks */
710 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
711
712 upper_limit -= meta_blocks;
713 upper_limit <<= bits;
714
715 res += 1LL << (bits-2);
716 res += 1LL << (2*(bits-2));
717 res += 1LL << (3*(bits-2));
718 res <<= bits;
719 if (res > upper_limit)
720 res = upper_limit;
721
722 if (res > MAX_LFS_FILESIZE)
723 res = MAX_LFS_FILESIZE;
724
725 return res;
726 }
727
728 static unsigned long descriptor_loc(struct super_block *sb,
729 unsigned long logic_sb_block,
730 int nr)
731 {
732 struct ext2_sb_info *sbi = EXT2_SB(sb);
733 unsigned long bg, first_meta_bg;
734 int has_super = 0;
735
736 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
737
738 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
739 nr < first_meta_bg)
740 return (logic_sb_block + nr + 1);
741 bg = sbi->s_desc_per_block * nr;
742 if (ext2_bg_has_super(sb, bg))
743 has_super = 1;
744
745 return ext2_group_first_block_no(sb, bg) + has_super;
746 }
747
748 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
749 {
750 struct buffer_head * bh;
751 struct ext2_sb_info * sbi;
752 struct ext2_super_block * es;
753 struct inode *root;
754 unsigned long block;
755 unsigned long sb_block = get_sb_block(&data);
756 unsigned long logic_sb_block;
757 unsigned long offset = 0;
758 unsigned long def_mount_opts;
759 long ret = -EINVAL;
760 int blocksize = BLOCK_SIZE;
761 int db_count;
762 int i, j;
763 __le32 features;
764 int err;
765
766 err = -ENOMEM;
767 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
768 if (!sbi)
769 goto failed_unlock;
770
771 sbi->s_blockgroup_lock =
772 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
773 if (!sbi->s_blockgroup_lock) {
774 kfree(sbi);
775 goto failed_unlock;
776 }
777 sb->s_fs_info = sbi;
778 sbi->s_sb_block = sb_block;
779
780 spin_lock_init(&sbi->s_lock);
781
782 /*
783 * See what the current blocksize for the device is, and
784 * use that as the blocksize. Otherwise (or if the blocksize
785 * is smaller than the default) use the default.
786 * This is important for devices that have a hardware
787 * sectorsize that is larger than the default.
788 */
789 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
790 if (!blocksize) {
791 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
792 goto failed_sbi;
793 }
794
795 /*
796 * If the superblock doesn't start on a hardware sector boundary,
797 * calculate the offset.
798 */
799 if (blocksize != BLOCK_SIZE) {
800 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
801 offset = (sb_block*BLOCK_SIZE) % blocksize;
802 } else {
803 logic_sb_block = sb_block;
804 }
805
806 if (!(bh = sb_bread(sb, logic_sb_block))) {
807 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
808 goto failed_sbi;
809 }
810 /*
811 * Note: s_es must be initialized as soon as possible because
812 * some ext2 macro-instructions depend on its value
813 */
814 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
815 sbi->s_es = es;
816 sb->s_magic = le16_to_cpu(es->s_magic);
817
818 if (sb->s_magic != EXT2_SUPER_MAGIC)
819 goto cantfind_ext2;
820
821 /* Set defaults before we parse the mount options */
822 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
823 if (def_mount_opts & EXT2_DEFM_DEBUG)
824 set_opt(sbi->s_mount_opt, DEBUG);
825 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
826 set_opt(sbi->s_mount_opt, GRPID);
827 if (def_mount_opts & EXT2_DEFM_UID16)
828 set_opt(sbi->s_mount_opt, NO_UID32);
829 #ifdef CONFIG_EXT2_FS_XATTR
830 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
831 set_opt(sbi->s_mount_opt, XATTR_USER);
832 #endif
833 #ifdef CONFIG_EXT2_FS_POSIX_ACL
834 if (def_mount_opts & EXT2_DEFM_ACL)
835 set_opt(sbi->s_mount_opt, POSIX_ACL);
836 #endif
837
838 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
839 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
840 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
841 set_opt(sbi->s_mount_opt, ERRORS_CONT);
842 else
843 set_opt(sbi->s_mount_opt, ERRORS_RO);
844
845 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
846 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
847
848 set_opt(sbi->s_mount_opt, RESERVATION);
849
850 if (!parse_options((char *) data, sb))
851 goto failed_mount;
852
853 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
854 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
855 MS_POSIXACL : 0);
856
857 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
858 EXT2_MOUNT_XIP if not */
859
860 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
861 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
862 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
863 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
864 ext2_msg(sb, KERN_WARNING,
865 "warning: feature flags set on rev 0 fs, "
866 "running e2fsck is recommended");
867 /*
868 * Check feature flags regardless of the revision level, since we
869 * previously didn't change the revision level when setting the flags,
870 * so there is a chance incompat flags are set on a rev 0 filesystem.
871 */
872 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
873 if (features) {
874 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
875 "unsupported optional features (%x)",
876 le32_to_cpu(features));
877 goto failed_mount;
878 }
879 if (!(sb->s_flags & MS_RDONLY) &&
880 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
881 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
882 "unsupported optional features (%x)",
883 le32_to_cpu(features));
884 goto failed_mount;
885 }
886
887 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
888
889 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
890 if (!silent)
891 ext2_msg(sb, KERN_ERR,
892 "error: unsupported blocksize for xip");
893 goto failed_mount;
894 }
895
896 /* If the blocksize doesn't match, re-read the thing.. */
897 if (sb->s_blocksize != blocksize) {
898 brelse(bh);
899
900 if (!sb_set_blocksize(sb, blocksize)) {
901 ext2_msg(sb, KERN_ERR,
902 "error: bad blocksize %d", blocksize);
903 goto failed_sbi;
904 }
905
906 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
907 offset = (sb_block*BLOCK_SIZE) % blocksize;
908 bh = sb_bread(sb, logic_sb_block);
909 if(!bh) {
910 ext2_msg(sb, KERN_ERR, "error: couldn't read"
911 "superblock on 2nd try");
912 goto failed_sbi;
913 }
914 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
915 sbi->s_es = es;
916 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
917 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
918 goto failed_mount;
919 }
920 }
921
922 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
923
924 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
925 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
926 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
927 } else {
928 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
929 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
930 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
931 !is_power_of_2(sbi->s_inode_size) ||
932 (sbi->s_inode_size > blocksize)) {
933 ext2_msg(sb, KERN_ERR,
934 "error: unsupported inode size: %d",
935 sbi->s_inode_size);
936 goto failed_mount;
937 }
938 }
939
940 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
941 le32_to_cpu(es->s_log_frag_size);
942 if (sbi->s_frag_size == 0)
943 goto cantfind_ext2;
944 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
945
946 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
947 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
948 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
949
950 if (EXT2_INODE_SIZE(sb) == 0)
951 goto cantfind_ext2;
952 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
953 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
954 goto cantfind_ext2;
955 sbi->s_itb_per_group = sbi->s_inodes_per_group /
956 sbi->s_inodes_per_block;
957 sbi->s_desc_per_block = sb->s_blocksize /
958 sizeof (struct ext2_group_desc);
959 sbi->s_sbh = bh;
960 sbi->s_mount_state = le16_to_cpu(es->s_state);
961 sbi->s_addr_per_block_bits =
962 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
963 sbi->s_desc_per_block_bits =
964 ilog2 (EXT2_DESC_PER_BLOCK(sb));
965
966 if (sb->s_magic != EXT2_SUPER_MAGIC)
967 goto cantfind_ext2;
968
969 if (sb->s_blocksize != bh->b_size) {
970 if (!silent)
971 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
972 goto failed_mount;
973 }
974
975 if (sb->s_blocksize != sbi->s_frag_size) {
976 ext2_msg(sb, KERN_ERR,
977 "error: fragsize %lu != blocksize %lu"
978 "(not supported yet)",
979 sbi->s_frag_size, sb->s_blocksize);
980 goto failed_mount;
981 }
982
983 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
984 ext2_msg(sb, KERN_ERR,
985 "error: #blocks per group too big: %lu",
986 sbi->s_blocks_per_group);
987 goto failed_mount;
988 }
989 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
990 ext2_msg(sb, KERN_ERR,
991 "error: #fragments per group too big: %lu",
992 sbi->s_frags_per_group);
993 goto failed_mount;
994 }
995 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
996 ext2_msg(sb, KERN_ERR,
997 "error: #inodes per group too big: %lu",
998 sbi->s_inodes_per_group);
999 goto failed_mount;
1000 }
1001
1002 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1003 goto cantfind_ext2;
1004 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1005 le32_to_cpu(es->s_first_data_block) - 1)
1006 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1007 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1008 EXT2_DESC_PER_BLOCK(sb);
1009 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1010 if (sbi->s_group_desc == NULL) {
1011 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1012 goto failed_mount;
1013 }
1014 bgl_lock_init(sbi->s_blockgroup_lock);
1015 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1016 if (!sbi->s_debts) {
1017 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1018 goto failed_mount_group_desc;
1019 }
1020 for (i = 0; i < db_count; i++) {
1021 block = descriptor_loc(sb, logic_sb_block, i);
1022 sbi->s_group_desc[i] = sb_bread(sb, block);
1023 if (!sbi->s_group_desc[i]) {
1024 for (j = 0; j < i; j++)
1025 brelse (sbi->s_group_desc[j]);
1026 ext2_msg(sb, KERN_ERR,
1027 "error: unable to read group descriptors");
1028 goto failed_mount_group_desc;
1029 }
1030 }
1031 if (!ext2_check_descriptors (sb)) {
1032 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1033 goto failed_mount2;
1034 }
1035 sbi->s_gdb_count = db_count;
1036 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1037 spin_lock_init(&sbi->s_next_gen_lock);
1038
1039 /* per fileystem reservation list head & lock */
1040 spin_lock_init(&sbi->s_rsv_window_lock);
1041 sbi->s_rsv_window_root = RB_ROOT;
1042 /*
1043 * Add a single, static dummy reservation to the start of the
1044 * reservation window list --- it gives us a placeholder for
1045 * append-at-start-of-list which makes the allocation logic
1046 * _much_ simpler.
1047 */
1048 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1049 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1050 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1051 sbi->s_rsv_window_head.rsv_goal_size = 0;
1052 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1053
1054 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1055 ext2_count_free_blocks(sb));
1056 if (!err) {
1057 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1058 ext2_count_free_inodes(sb));
1059 }
1060 if (!err) {
1061 err = percpu_counter_init(&sbi->s_dirs_counter,
1062 ext2_count_dirs(sb));
1063 }
1064 if (err) {
1065 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1066 goto failed_mount3;
1067 }
1068 /*
1069 * set up enough so that it can read an inode
1070 */
1071 sb->s_op = &ext2_sops;
1072 sb->s_export_op = &ext2_export_ops;
1073 sb->s_xattr = ext2_xattr_handlers;
1074
1075 #ifdef CONFIG_QUOTA
1076 sb->dq_op = &dquot_operations;
1077 sb->s_qcop = &dquot_quotactl_ops;
1078 #endif
1079
1080 root = ext2_iget(sb, EXT2_ROOT_INO);
1081 if (IS_ERR(root)) {
1082 ret = PTR_ERR(root);
1083 goto failed_mount3;
1084 }
1085 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1086 iput(root);
1087 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1088 goto failed_mount3;
1089 }
1090
1091 sb->s_root = d_alloc_root(root);
1092 if (!sb->s_root) {
1093 iput(root);
1094 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1095 ret = -ENOMEM;
1096 goto failed_mount3;
1097 }
1098 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1099 ext2_msg(sb, KERN_WARNING,
1100 "warning: mounting ext3 filesystem as ext2");
1101 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1102 sb->s_flags |= MS_RDONLY;
1103 ext2_write_super(sb);
1104 return 0;
1105
1106 cantfind_ext2:
1107 if (!silent)
1108 ext2_msg(sb, KERN_ERR,
1109 "error: can't find an ext2 filesystem on dev %s.",
1110 sb->s_id);
1111 goto failed_mount;
1112 failed_mount3:
1113 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1114 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1115 percpu_counter_destroy(&sbi->s_dirs_counter);
1116 failed_mount2:
1117 for (i = 0; i < db_count; i++)
1118 brelse(sbi->s_group_desc[i]);
1119 failed_mount_group_desc:
1120 kfree(sbi->s_group_desc);
1121 kfree(sbi->s_debts);
1122 failed_mount:
1123 brelse(bh);
1124 failed_sbi:
1125 sb->s_fs_info = NULL;
1126 kfree(sbi->s_blockgroup_lock);
1127 kfree(sbi);
1128 failed_unlock:
1129 return ret;
1130 }
1131
1132 static void ext2_clear_super_error(struct super_block *sb)
1133 {
1134 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1135
1136 if (buffer_write_io_error(sbh)) {
1137 /*
1138 * Oh, dear. A previous attempt to write the
1139 * superblock failed. This could happen because the
1140 * USB device was yanked out. Or it could happen to
1141 * be a transient write error and maybe the block will
1142 * be remapped. Nothing we can do but to retry the
1143 * write and hope for the best.
1144 */
1145 ext2_msg(sb, KERN_ERR,
1146 "previous I/O error to superblock detected\n");
1147 clear_buffer_write_io_error(sbh);
1148 set_buffer_uptodate(sbh);
1149 }
1150 }
1151
1152 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1153 int wait)
1154 {
1155 ext2_clear_super_error(sb);
1156 spin_lock(&EXT2_SB(sb)->s_lock);
1157 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1158 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1159 es->s_wtime = cpu_to_le32(get_seconds());
1160 /* unlock before we do IO */
1161 spin_unlock(&EXT2_SB(sb)->s_lock);
1162 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1163 if (wait)
1164 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1165 sb->s_dirt = 0;
1166 }
1167
1168 /*
1169 * In the second extended file system, it is not necessary to
1170 * write the super block since we use a mapping of the
1171 * disk super block in a buffer.
1172 *
1173 * However, this function is still used to set the fs valid
1174 * flags to 0. We need to set this flag to 0 since the fs
1175 * may have been checked while mounted and e2fsck may have
1176 * set s_state to EXT2_VALID_FS after some corrections.
1177 */
1178 static int ext2_sync_fs(struct super_block *sb, int wait)
1179 {
1180 struct ext2_sb_info *sbi = EXT2_SB(sb);
1181 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1182
1183 spin_lock(&sbi->s_lock);
1184 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1185 ext2_debug("setting valid to 0\n");
1186 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1187 }
1188 spin_unlock(&sbi->s_lock);
1189 ext2_sync_super(sb, es, wait);
1190 return 0;
1191 }
1192
1193
1194 void ext2_write_super(struct super_block *sb)
1195 {
1196 if (!(sb->s_flags & MS_RDONLY))
1197 ext2_sync_fs(sb, 1);
1198 else
1199 sb->s_dirt = 0;
1200 }
1201
1202 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1203 {
1204 struct ext2_sb_info * sbi = EXT2_SB(sb);
1205 struct ext2_super_block * es;
1206 unsigned long old_mount_opt = sbi->s_mount_opt;
1207 struct ext2_mount_options old_opts;
1208 unsigned long old_sb_flags;
1209 int err;
1210
1211 spin_lock(&sbi->s_lock);
1212
1213 /* Store the old options */
1214 old_sb_flags = sb->s_flags;
1215 old_opts.s_mount_opt = sbi->s_mount_opt;
1216 old_opts.s_resuid = sbi->s_resuid;
1217 old_opts.s_resgid = sbi->s_resgid;
1218
1219 /*
1220 * Allow the "check" option to be passed as a remount option.
1221 */
1222 if (!parse_options(data, sb)) {
1223 err = -EINVAL;
1224 goto restore_opts;
1225 }
1226
1227 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1228 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1229
1230 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1231 EXT2_MOUNT_XIP if not */
1232
1233 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1234 ext2_msg(sb, KERN_WARNING,
1235 "warning: unsupported blocksize for xip");
1236 err = -EINVAL;
1237 goto restore_opts;
1238 }
1239
1240 es = sbi->s_es;
1241 if ((sbi->s_mount_opt ^ old_mount_opt) & EXT2_MOUNT_XIP) {
1242 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1243 "xip flag with busy inodes while remounting");
1244 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1245 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1246 }
1247 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1248 spin_unlock(&sbi->s_lock);
1249 return 0;
1250 }
1251 if (*flags & MS_RDONLY) {
1252 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1253 !(sbi->s_mount_state & EXT2_VALID_FS)) {
1254 spin_unlock(&sbi->s_lock);
1255 return 0;
1256 }
1257
1258 /*
1259 * OK, we are remounting a valid rw partition rdonly, so set
1260 * the rdonly flag and then mark the partition as valid again.
1261 */
1262 es->s_state = cpu_to_le16(sbi->s_mount_state);
1263 es->s_mtime = cpu_to_le32(get_seconds());
1264 spin_unlock(&sbi->s_lock);
1265
1266 err = dquot_suspend(sb, -1);
1267 if (err < 0) {
1268 spin_lock(&sbi->s_lock);
1269 goto restore_opts;
1270 }
1271
1272 ext2_sync_super(sb, es, 1);
1273 } else {
1274 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1275 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1276 if (ret) {
1277 ext2_msg(sb, KERN_WARNING,
1278 "warning: couldn't remount RDWR because of "
1279 "unsupported optional features (%x).",
1280 le32_to_cpu(ret));
1281 err = -EROFS;
1282 goto restore_opts;
1283 }
1284 /*
1285 * Mounting a RDONLY partition read-write, so reread and
1286 * store the current valid flag. (It may have been changed
1287 * by e2fsck since we originally mounted the partition.)
1288 */
1289 sbi->s_mount_state = le16_to_cpu(es->s_state);
1290 if (!ext2_setup_super (sb, es, 0))
1291 sb->s_flags &= ~MS_RDONLY;
1292 spin_unlock(&sbi->s_lock);
1293
1294 ext2_write_super(sb);
1295
1296 dquot_resume(sb, -1);
1297 }
1298
1299 return 0;
1300 restore_opts:
1301 sbi->s_mount_opt = old_opts.s_mount_opt;
1302 sbi->s_resuid = old_opts.s_resuid;
1303 sbi->s_resgid = old_opts.s_resgid;
1304 sb->s_flags = old_sb_flags;
1305 spin_unlock(&sbi->s_lock);
1306 return err;
1307 }
1308
1309 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1310 {
1311 struct super_block *sb = dentry->d_sb;
1312 struct ext2_sb_info *sbi = EXT2_SB(sb);
1313 struct ext2_super_block *es = sbi->s_es;
1314 u64 fsid;
1315
1316 spin_lock(&sbi->s_lock);
1317
1318 if (test_opt (sb, MINIX_DF))
1319 sbi->s_overhead_last = 0;
1320 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1321 unsigned long i, overhead = 0;
1322 smp_rmb();
1323
1324 /*
1325 * Compute the overhead (FS structures). This is constant
1326 * for a given filesystem unless the number of block groups
1327 * changes so we cache the previous value until it does.
1328 */
1329
1330 /*
1331 * All of the blocks before first_data_block are
1332 * overhead
1333 */
1334 overhead = le32_to_cpu(es->s_first_data_block);
1335
1336 /*
1337 * Add the overhead attributed to the superblock and
1338 * block group descriptors. If the sparse superblocks
1339 * feature is turned on, then not all groups have this.
1340 */
1341 for (i = 0; i < sbi->s_groups_count; i++)
1342 overhead += ext2_bg_has_super(sb, i) +
1343 ext2_bg_num_gdb(sb, i);
1344
1345 /*
1346 * Every block group has an inode bitmap, a block
1347 * bitmap, and an inode table.
1348 */
1349 overhead += (sbi->s_groups_count *
1350 (2 + sbi->s_itb_per_group));
1351 sbi->s_overhead_last = overhead;
1352 smp_wmb();
1353 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1354 }
1355
1356 buf->f_type = EXT2_SUPER_MAGIC;
1357 buf->f_bsize = sb->s_blocksize;
1358 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1359 buf->f_bfree = ext2_count_free_blocks(sb);
1360 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1361 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1362 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1363 buf->f_bavail = 0;
1364 buf->f_files = le32_to_cpu(es->s_inodes_count);
1365 buf->f_ffree = ext2_count_free_inodes(sb);
1366 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1367 buf->f_namelen = EXT2_NAME_LEN;
1368 fsid = le64_to_cpup((void *)es->s_uuid) ^
1369 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1370 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1371 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1372 spin_unlock(&sbi->s_lock);
1373 return 0;
1374 }
1375
1376 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1377 int flags, const char *dev_name, void *data)
1378 {
1379 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1380 }
1381
1382 #ifdef CONFIG_QUOTA
1383
1384 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1385 * acquiring the locks... As quota files are never truncated and quota code
1386 * itself serializes the operations (and no one else should touch the files)
1387 * we don't have to be afraid of races */
1388 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1389 size_t len, loff_t off)
1390 {
1391 struct inode *inode = sb_dqopt(sb)->files[type];
1392 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1393 int err = 0;
1394 int offset = off & (sb->s_blocksize - 1);
1395 int tocopy;
1396 size_t toread;
1397 struct buffer_head tmp_bh;
1398 struct buffer_head *bh;
1399 loff_t i_size = i_size_read(inode);
1400
1401 if (off > i_size)
1402 return 0;
1403 if (off+len > i_size)
1404 len = i_size-off;
1405 toread = len;
1406 while (toread > 0) {
1407 tocopy = sb->s_blocksize - offset < toread ?
1408 sb->s_blocksize - offset : toread;
1409
1410 tmp_bh.b_state = 0;
1411 tmp_bh.b_size = sb->s_blocksize;
1412 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1413 if (err < 0)
1414 return err;
1415 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1416 memset(data, 0, tocopy);
1417 else {
1418 bh = sb_bread(sb, tmp_bh.b_blocknr);
1419 if (!bh)
1420 return -EIO;
1421 memcpy(data, bh->b_data+offset, tocopy);
1422 brelse(bh);
1423 }
1424 offset = 0;
1425 toread -= tocopy;
1426 data += tocopy;
1427 blk++;
1428 }
1429 return len;
1430 }
1431
1432 /* Write to quotafile */
1433 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1434 const char *data, size_t len, loff_t off)
1435 {
1436 struct inode *inode = sb_dqopt(sb)->files[type];
1437 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1438 int err = 0;
1439 int offset = off & (sb->s_blocksize - 1);
1440 int tocopy;
1441 size_t towrite = len;
1442 struct buffer_head tmp_bh;
1443 struct buffer_head *bh;
1444
1445 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1446 while (towrite > 0) {
1447 tocopy = sb->s_blocksize - offset < towrite ?
1448 sb->s_blocksize - offset : towrite;
1449
1450 tmp_bh.b_state = 0;
1451 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1452 if (err < 0)
1453 goto out;
1454 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1455 bh = sb_bread(sb, tmp_bh.b_blocknr);
1456 else
1457 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1458 if (!bh) {
1459 err = -EIO;
1460 goto out;
1461 }
1462 lock_buffer(bh);
1463 memcpy(bh->b_data+offset, data, tocopy);
1464 flush_dcache_page(bh->b_page);
1465 set_buffer_uptodate(bh);
1466 mark_buffer_dirty(bh);
1467 unlock_buffer(bh);
1468 brelse(bh);
1469 offset = 0;
1470 towrite -= tocopy;
1471 data += tocopy;
1472 blk++;
1473 }
1474 out:
1475 if (len == towrite) {
1476 mutex_unlock(&inode->i_mutex);
1477 return err;
1478 }
1479 if (inode->i_size < off+len-towrite)
1480 i_size_write(inode, off+len-towrite);
1481 inode->i_version++;
1482 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1483 mark_inode_dirty(inode);
1484 mutex_unlock(&inode->i_mutex);
1485 return len - towrite;
1486 }
1487
1488 #endif
1489
1490 static struct file_system_type ext2_fs_type = {
1491 .owner = THIS_MODULE,
1492 .name = "ext2",
1493 .mount = ext2_mount,
1494 .kill_sb = kill_block_super,
1495 .fs_flags = FS_REQUIRES_DEV,
1496 };
1497
1498 static int __init init_ext2_fs(void)
1499 {
1500 int err = init_ext2_xattr();
1501 if (err)
1502 return err;
1503 err = init_inodecache();
1504 if (err)
1505 goto out1;
1506 err = register_filesystem(&ext2_fs_type);
1507 if (err)
1508 goto out;
1509 return 0;
1510 out:
1511 destroy_inodecache();
1512 out1:
1513 exit_ext2_xattr();
1514 return err;
1515 }
1516
1517 static void __exit exit_ext2_fs(void)
1518 {
1519 unregister_filesystem(&ext2_fs_type);
1520 destroy_inodecache();
1521 exit_ext2_xattr();
1522 }
1523
1524 module_init(init_ext2_fs)
1525 module_exit(exit_ext2_fs)