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allow coexistance of N build and AC build.
[tomato.git] / release / src-rt-6.x / linux / linux-2.6 / fs / ext2 / super.c
blob8ddf74988e3984dd31797ea7084043a4a5ca1914
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/smp_lock.h>
30 #include <linux/vfs.h>
31 #include <linux/seq_file.h>
32 #include <linux/mount.h>
33 #include <asm/uaccess.h>
34 #include "ext2.h"
35 #include "xattr.h"
36 #include "acl.h"
37 #include "xip.h"
38
39 static void ext2_sync_super(struct super_block *sb,
40 struct ext2_super_block *es);
41 static int ext2_remount (struct super_block * sb, int * flags, char * data);
42 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
43
44 void ext2_error (struct super_block * sb, const char * function,
45 const char * fmt, ...)
46 {
47 va_list args;
48 struct ext2_sb_info *sbi = EXT2_SB(sb);
49 struct ext2_super_block *es = sbi->s_es;
50
51 if (!(sb->s_flags & MS_RDONLY)) {
52 sbi->s_mount_state |= EXT2_ERROR_FS;
53 es->s_state =
54 cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
55 ext2_sync_super(sb, es);
56 }
57
58 va_start(args, fmt);
59 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
60 vprintk(fmt, args);
61 printk("\n");
62 va_end(args);
63
64 if (test_opt(sb, ERRORS_PANIC))
65 panic("EXT2-fs panic from previous error\n");
66 if (test_opt(sb, ERRORS_RO)) {
67 printk("Remounting filesystem read-only\n");
68 sb->s_flags |= MS_RDONLY;
69 }
70 }
71
72 void ext2_warning (struct super_block * sb, const char * function,
73 const char * fmt, ...)
74 {
75 va_list args;
76
77 va_start(args, fmt);
78 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
79 sb->s_id, function);
80 vprintk(fmt, args);
81 printk("\n");
82 va_end(args);
83 }
84
85 void ext2_update_dynamic_rev(struct super_block *sb)
86 {
87 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
88
89 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
90 return;
91
92 ext2_warning(sb, __FUNCTION__,
93 "updating to rev %d because of new feature flag, "
94 "running e2fsck is recommended",
95 EXT2_DYNAMIC_REV);
96
97 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
98 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
99 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
100 /* leave es->s_feature_*compat flags alone */
101 /* es->s_uuid will be set by e2fsck if empty */
102
103 /*
104 * The rest of the superblock fields should be zero, and if not it
105 * means they are likely already in use, so leave them alone. We
106 * can leave it up to e2fsck to clean up any inconsistencies there.
107 */
108 }
109
110 static void ext2_put_super (struct super_block * sb)
111 {
112 int db_count;
113 int i;
114 struct ext2_sb_info *sbi = EXT2_SB(sb);
115
116 ext2_xattr_put_super(sb);
117 if (!(sb->s_flags & MS_RDONLY)) {
118 struct ext2_super_block *es = sbi->s_es;
119
120 es->s_state = cpu_to_le16(sbi->s_mount_state);
121 ext2_sync_super(sb, es);
122 }
123 db_count = sbi->s_gdb_count;
124 for (i = 0; i < db_count; i++)
125 if (sbi->s_group_desc[i])
126 brelse (sbi->s_group_desc[i]);
127 kfree(sbi->s_group_desc);
128 kfree(sbi->s_debts);
129 percpu_counter_destroy(&sbi->s_freeblocks_counter);
130 percpu_counter_destroy(&sbi->s_freeinodes_counter);
131 percpu_counter_destroy(&sbi->s_dirs_counter);
132 brelse (sbi->s_sbh);
133 sb->s_fs_info = NULL;
134 kfree(sbi);
135
136 return;
137 }
138
139 static struct kmem_cache * ext2_inode_cachep;
140
141 static struct inode *ext2_alloc_inode(struct super_block *sb)
142 {
143 struct ext2_inode_info *ei;
144 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
145 if (!ei)
146 return NULL;
147 #ifdef CONFIG_EXT2_FS_POSIX_ACL
148 ei->i_acl = EXT2_ACL_NOT_CACHED;
149 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
150 #endif
151 ei->i_block_alloc_info = NULL;
152 ei->vfs_inode.i_version = 1;
153 return &ei->vfs_inode;
154 }
155
156 static void ext2_destroy_inode(struct inode *inode)
157 {
158 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
159 }
160
161 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
162 {
163 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
164
165 rwlock_init(&ei->i_meta_lock);
166 #ifdef CONFIG_EXT2_FS_XATTR
167 init_rwsem(&ei->xattr_sem);
168 #endif
169 mutex_init(&ei->truncate_mutex);
170 inode_init_once(&ei->vfs_inode);
171 }
172
173 static int init_inodecache(void)
174 {
175 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
176 sizeof(struct ext2_inode_info),
177 0, (SLAB_RECLAIM_ACCOUNT|
178 SLAB_MEM_SPREAD),
179 init_once, NULL);
180 if (ext2_inode_cachep == NULL)
181 return -ENOMEM;
182 return 0;
183 }
184
185 static void destroy_inodecache(void)
186 {
187 kmem_cache_destroy(ext2_inode_cachep);
188 }
189
190 static void ext2_clear_inode(struct inode *inode)
191 {
192 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
193 #ifdef CONFIG_EXT2_FS_POSIX_ACL
194 struct ext2_inode_info *ei = EXT2_I(inode);
195
196 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
197 posix_acl_release(ei->i_acl);
198 ei->i_acl = EXT2_ACL_NOT_CACHED;
199 }
200 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
201 posix_acl_release(ei->i_default_acl);
202 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
203 }
204 #endif
205 ext2_discard_reservation(inode);
206 EXT2_I(inode)->i_block_alloc_info = NULL;
207 if (unlikely(rsv))
208 kfree(rsv);
209 }
210
211 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
212 {
213 struct ext2_sb_info *sbi = EXT2_SB(vfs->mnt_sb);
214
215 if (sbi->s_mount_opt & EXT2_MOUNT_GRPID)
216 seq_puts(seq, ",grpid");
217
218 #if defined(CONFIG_QUOTA)
219 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
220 seq_puts(seq, ",usrquota");
221
222 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
223 seq_puts(seq, ",grpquota");
224 #endif
225
226 #if defined(CONFIG_EXT2_FS_XIP)
227 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
228 seq_puts(seq, ",xip");
229 #endif
230
231 return 0;
232 }
233
234 #ifdef CONFIG_QUOTA
235 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
236 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
237 #endif
238
239 static const struct super_operations ext2_sops = {
240 .alloc_inode = ext2_alloc_inode,
241 .destroy_inode = ext2_destroy_inode,
242 .read_inode = ext2_read_inode,
243 .write_inode = ext2_write_inode,
244 .delete_inode = ext2_delete_inode,
245 .put_super = ext2_put_super,
246 .write_super = ext2_write_super,
247 .statfs = ext2_statfs,
248 .remount_fs = ext2_remount,
249 .clear_inode = ext2_clear_inode,
250 .show_options = ext2_show_options,
251 #ifdef CONFIG_QUOTA
252 .quota_read = ext2_quota_read,
253 .quota_write = ext2_quota_write,
254 #endif
255 };
256
257 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
258 u64 ino, u32 generation)
259 {
260 struct inode *inode;
261
262 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
263 return ERR_PTR(-ESTALE);
264 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
265 return ERR_PTR(-ESTALE);
266
267 /* iget isn't really right if the inode is currently unallocated!!
268 * ext2_read_inode currently does appropriate checks, but
269 * it might be "neater" to call ext2_get_inode first and check
270 * if the inode is valid.....
271 */
272 inode = iget(sb, ino);
273 if (inode == NULL)
274 return ERR_PTR(-ENOMEM);
275 if (is_bad_inode(inode) ||
276 (generation && inode->i_generation != generation)) {
277 /* we didn't find the right inode.. */
278 iput(inode);
279 return ERR_PTR(-ESTALE);
280 }
281 return inode;
282 }
283
284 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
285 int fh_len, int fh_type)
286 {
287 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
288 ext2_nfs_get_inode);
289 }
290
291 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
292 int fh_len, int fh_type)
293 {
294 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
295 ext2_nfs_get_inode);
296 }
297
298 /* Yes, most of these are left as NULL!!
299 * A NULL value implies the default, which works with ext2-like file
300 * systems, but can be improved upon.
301 * Currently only get_parent is required.
302 */
303 static const struct export_operations ext2_export_ops = {
304 .fh_to_dentry = ext2_fh_to_dentry,
305 .fh_to_parent = ext2_fh_to_parent,
306 .get_parent = ext2_get_parent,
307 };
308
309 static unsigned long get_sb_block(void **data)
310 {
311 unsigned long sb_block;
312 char *options = (char *) *data;
313
314 if (!options || strncmp(options, "sb=", 3) != 0)
315 return 1; /* Default location */
316 options += 3;
317 sb_block = simple_strtoul(options, &options, 0);
318 if (*options && *options != ',') {
319 printk("EXT2-fs: Invalid sb specification: %s\n",
320 (char *) *data);
321 return 1;
322 }
323 if (*options == ',')
324 options++;
325 *data = (void *) options;
326 return sb_block;
327 }
328
329 enum {
330 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
331 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
332 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
333 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
334 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
335 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
336 };
337
338 static match_table_t tokens = {
339 {Opt_bsd_df, "bsddf"},
340 {Opt_minix_df, "minixdf"},
341 {Opt_grpid, "grpid"},
342 {Opt_grpid, "bsdgroups"},
343 {Opt_nogrpid, "nogrpid"},
344 {Opt_nogrpid, "sysvgroups"},
345 {Opt_resgid, "resgid=%u"},
346 {Opt_resuid, "resuid=%u"},
347 {Opt_sb, "sb=%u"},
348 {Opt_err_cont, "errors=continue"},
349 {Opt_err_panic, "errors=panic"},
350 {Opt_err_ro, "errors=remount-ro"},
351 {Opt_nouid32, "nouid32"},
352 {Opt_nocheck, "check=none"},
353 {Opt_nocheck, "nocheck"},
354 {Opt_debug, "debug"},
355 {Opt_oldalloc, "oldalloc"},
356 {Opt_orlov, "orlov"},
357 {Opt_nobh, "nobh"},
358 {Opt_user_xattr, "user_xattr"},
359 {Opt_nouser_xattr, "nouser_xattr"},
360 {Opt_acl, "acl"},
361 {Opt_noacl, "noacl"},
362 {Opt_xip, "xip"},
363 {Opt_grpquota, "grpquota"},
364 {Opt_ignore, "noquota"},
365 {Opt_quota, "quota"},
366 {Opt_usrquota, "usrquota"},
367 {Opt_reservation, "reservation"},
368 {Opt_noreservation, "noreservation"},
369 {Opt_err, NULL}
370 };
371
372 static int parse_options (char * options,
373 struct ext2_sb_info *sbi)
374 {
375 char * p;
376 substring_t args[MAX_OPT_ARGS];
377 int option;
378
379 if (!options)
380 return 1;
381
382 while ((p = strsep (&options, ",")) != NULL) {
383 int token;
384 if (!*p)
385 continue;
386
387 token = match_token(p, tokens, args);
388 switch (token) {
389 case Opt_bsd_df:
390 clear_opt (sbi->s_mount_opt, MINIX_DF);
391 break;
392 case Opt_minix_df:
393 set_opt (sbi->s_mount_opt, MINIX_DF);
394 break;
395 case Opt_grpid:
396 set_opt (sbi->s_mount_opt, GRPID);
397 break;
398 case Opt_nogrpid:
399 clear_opt (sbi->s_mount_opt, GRPID);
400 break;
401 case Opt_resuid:
402 if (match_int(&args[0], &option))
403 return 0;
404 sbi->s_resuid = option;
405 break;
406 case Opt_resgid:
407 if (match_int(&args[0], &option))
408 return 0;
409 sbi->s_resgid = option;
410 break;
411 case Opt_sb:
412 /* handled by get_sb_block() instead of here */
413 /* *sb_block = match_int(&args[0]); */
414 break;
415 case Opt_err_panic:
416 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
417 clear_opt (sbi->s_mount_opt, ERRORS_RO);
418 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
419 break;
420 case Opt_err_ro:
421 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
422 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
423 set_opt (sbi->s_mount_opt, ERRORS_RO);
424 break;
425 case Opt_err_cont:
426 clear_opt (sbi->s_mount_opt, ERRORS_RO);
427 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
428 set_opt (sbi->s_mount_opt, ERRORS_CONT);
429 break;
430 case Opt_nouid32:
431 set_opt (sbi->s_mount_opt, NO_UID32);
432 break;
433 case Opt_nocheck:
434 clear_opt (sbi->s_mount_opt, CHECK);
435 break;
436 case Opt_debug:
437 set_opt (sbi->s_mount_opt, DEBUG);
438 break;
439 case Opt_oldalloc:
440 set_opt (sbi->s_mount_opt, OLDALLOC);
441 break;
442 case Opt_orlov:
443 clear_opt (sbi->s_mount_opt, OLDALLOC);
444 break;
445 case Opt_nobh:
446 set_opt (sbi->s_mount_opt, NOBH);
447 break;
448 #ifdef CONFIG_EXT2_FS_XATTR
449 case Opt_user_xattr:
450 set_opt (sbi->s_mount_opt, XATTR_USER);
451 break;
452 case Opt_nouser_xattr:
453 clear_opt (sbi->s_mount_opt, XATTR_USER);
454 break;
455 #else
456 case Opt_user_xattr:
457 case Opt_nouser_xattr:
458 printk("EXT2 (no)user_xattr options not supported\n");
459 break;
460 #endif
461 #ifdef CONFIG_EXT2_FS_POSIX_ACL
462 case Opt_acl:
463 set_opt(sbi->s_mount_opt, POSIX_ACL);
464 break;
465 case Opt_noacl:
466 clear_opt(sbi->s_mount_opt, POSIX_ACL);
467 break;
468 #else
469 case Opt_acl:
470 case Opt_noacl:
471 printk("EXT2 (no)acl options not supported\n");
472 break;
473 #endif
474 case Opt_xip:
475 #ifdef CONFIG_EXT2_FS_XIP
476 set_opt (sbi->s_mount_opt, XIP);
477 #else
478 printk("EXT2 xip option not supported\n");
479 #endif
480 break;
481
482 #if defined(CONFIG_QUOTA)
483 case Opt_quota:
484 case Opt_usrquota:
485 set_opt(sbi->s_mount_opt, USRQUOTA);
486 break;
487
488 case Opt_grpquota:
489 set_opt(sbi->s_mount_opt, GRPQUOTA);
490 break;
491 #else
492 case Opt_quota:
493 case Opt_usrquota:
494 case Opt_grpquota:
495 printk(KERN_ERR
496 "EXT2-fs: quota operations not supported.\n");
497
498 break;
499 #endif
500
501 case Opt_reservation:
502 set_opt(sbi->s_mount_opt, RESERVATION);
503 printk("reservations ON\n");
504 break;
505 case Opt_noreservation:
506 clear_opt(sbi->s_mount_opt, RESERVATION);
507 printk("reservations OFF\n");
508 break;
509 case Opt_ignore:
510 break;
511 default:
512 return 0;
513 }
514 }
515 return 1;
516 }
517
518 static int ext2_setup_super (struct super_block * sb,
519 struct ext2_super_block * es,
520 int read_only)
521 {
522 int res = 0;
523 struct ext2_sb_info *sbi = EXT2_SB(sb);
524
525 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
526 printk ("EXT2-fs warning: revision level too high, "
527 "forcing read-only mode\n");
528 res = MS_RDONLY;
529 }
530 if (read_only)
531 return res;
532 if (!(sbi->s_mount_state & EXT2_VALID_FS))
533 printk ("EXT2-fs warning: mounting unchecked fs, "
534 "running e2fsck is recommended\n");
535 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
536 printk ("EXT2-fs warning: mounting fs with errors, "
537 "running e2fsck is recommended\n");
538 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
539 le16_to_cpu(es->s_mnt_count) >=
540 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
541 printk ("EXT2-fs warning: maximal mount count reached, "
542 "running e2fsck is recommended\n");
543 else if (le32_to_cpu(es->s_checkinterval) &&
544 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
545 printk ("EXT2-fs warning: checktime reached, "
546 "running e2fsck is recommended\n");
547 if (!le16_to_cpu(es->s_max_mnt_count))
548 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
549 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
550 ext2_write_super(sb);
551 if (test_opt (sb, DEBUG))
552 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
553 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
554 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
555 sbi->s_frag_size,
556 sbi->s_groups_count,
557 EXT2_BLOCKS_PER_GROUP(sb),
558 EXT2_INODES_PER_GROUP(sb),
559 sbi->s_mount_opt);
560 return res;
561 }
562
563 static int ext2_check_descriptors (struct super_block * sb)
564 {
565 int i;
566 int desc_block = 0;
567 struct ext2_sb_info *sbi = EXT2_SB(sb);
568 struct ext2_group_desc * gdp = NULL;
569
570 ext2_debug ("Checking group descriptors");
571
572 for (i = 0; i < sbi->s_groups_count; i++)
573 {
574 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
575 ext2_fsblk_t last_block;
576
577 if (i == sbi->s_groups_count - 1)
578 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
579 else
580 last_block = first_block +
581 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
582
583 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
584 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
585 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
586 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
587 {
588 ext2_error (sb, "ext2_check_descriptors",
589 "Block bitmap for group %d"
590 " not in group (block %lu)!",
591 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
592 return 0;
593 }
594 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
595 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
596 {
597 ext2_error (sb, "ext2_check_descriptors",
598 "Inode bitmap for group %d"
599 " not in group (block %lu)!",
600 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
601 return 0;
602 }
603 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
604 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
605 last_block)
606 {
607 ext2_error (sb, "ext2_check_descriptors",
608 "Inode table for group %d"
609 " not in group (block %lu)!",
610 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
611 return 0;
612 }
613 gdp++;
614 }
615 return 1;
616 }
617
618 /*
619 * Maximal file size. There is a direct, and {,double-,triple-}indirect
620 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
621 * We need to be 1 filesystem block less than the 2^32 sector limit.
622 */
623 static loff_t ext2_max_size(int bits)
624 {
625 loff_t res = EXT2_NDIR_BLOCKS;
626 int meta_blocks;
627 loff_t upper_limit;
628
629 /* This is calculated to be the largest file size for a
630 * dense, file such that the total number of
631 * sectors in the file, including data and all indirect blocks,
632 * does not exceed 2^32 -1
633 * __u32 i_blocks representing the total number of
634 * 512 bytes blocks of the file
635 */
636 upper_limit = (1LL << 32) - 1;
637
638 /* total blocks in file system block size */
639 upper_limit >>= (bits - 9);
640
641
642 /* indirect blocks */
643 meta_blocks = 1;
644 /* double indirect blocks */
645 meta_blocks += 1 + (1LL << (bits-2));
646 /* tripple indirect blocks */
647 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
648
649 upper_limit -= meta_blocks;
650 upper_limit <<= bits;
651
652 res += 1LL << (bits-2);
653 res += 1LL << (2*(bits-2));
654 res += 1LL << (3*(bits-2));
655 res <<= bits;
656 if (res > upper_limit)
657 res = upper_limit;
658
659 if (res > MAX_LFS_FILESIZE)
660 res = MAX_LFS_FILESIZE;
661
662 return res;
663 }
664
665 static unsigned long descriptor_loc(struct super_block *sb,
666 unsigned long logic_sb_block,
667 int nr)
668 {
669 struct ext2_sb_info *sbi = EXT2_SB(sb);
670 unsigned long bg, first_meta_bg;
671 int has_super = 0;
672
673 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
674
675 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
676 nr < first_meta_bg)
677 return (logic_sb_block + nr + 1);
678 bg = sbi->s_desc_per_block * nr;
679 if (ext2_bg_has_super(sb, bg))
680 has_super = 1;
681
682 return ext2_group_first_block_no(sb, bg) + has_super;
683 }
684
685 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
686 {
687 struct buffer_head * bh;
688 struct ext2_sb_info * sbi;
689 struct ext2_super_block * es;
690 struct inode *root;
691 unsigned long block;
692 unsigned long sb_block = get_sb_block(&data);
693 unsigned long logic_sb_block;
694 unsigned long offset = 0;
695 unsigned long def_mount_opts;
696 int blocksize = BLOCK_SIZE;
697 int db_count;
698 int i, j;
699 __le32 features;
700
701 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
702 if (!sbi)
703 return -ENOMEM;
704 sb->s_fs_info = sbi;
705
706 /*
707 * See what the current blocksize for the device is, and
708 * use that as the blocksize. Otherwise (or if the blocksize
709 * is smaller than the default) use the default.
710 * This is important for devices that have a hardware
711 * sectorsize that is larger than the default.
712 */
713 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
714 if (!blocksize) {
715 printk ("EXT2-fs: unable to set blocksize\n");
716 goto failed_sbi;
717 }
718
719 /*
720 * If the superblock doesn't start on a hardware sector boundary,
721 * calculate the offset.
722 */
723 if (blocksize != BLOCK_SIZE) {
724 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
725 offset = (sb_block*BLOCK_SIZE) % blocksize;
726 } else {
727 logic_sb_block = sb_block;
728 }
729
730 if (!(bh = sb_bread(sb, logic_sb_block))) {
731 printk ("EXT2-fs: unable to read superblock\n");
732 goto failed_sbi;
733 }
734 /*
735 * Note: s_es must be initialized as soon as possible because
736 * some ext2 macro-instructions depend on its value
737 */
738 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
739 sbi->s_es = es;
740 sb->s_magic = le16_to_cpu(es->s_magic);
741
742 if (sb->s_magic != EXT2_SUPER_MAGIC)
743 goto cantfind_ext2;
744
745 /* Set defaults before we parse the mount options */
746 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
747 if (def_mount_opts & EXT2_DEFM_DEBUG)
748 set_opt(sbi->s_mount_opt, DEBUG);
749 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
750 set_opt(sbi->s_mount_opt, GRPID);
751 if (def_mount_opts & EXT2_DEFM_UID16)
752 set_opt(sbi->s_mount_opt, NO_UID32);
753 #ifdef CONFIG_EXT2_FS_XATTR
754 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
755 set_opt(sbi->s_mount_opt, XATTR_USER);
756 #endif
757 #ifdef CONFIG_EXT2_FS_POSIX_ACL
758 if (def_mount_opts & EXT2_DEFM_ACL)
759 set_opt(sbi->s_mount_opt, POSIX_ACL);
760 #endif
761
762 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
763 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
764 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
765 set_opt(sbi->s_mount_opt, ERRORS_RO);
766 else
767 set_opt(sbi->s_mount_opt, ERRORS_CONT);
768
769 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
770 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
771
772 set_opt(sbi->s_mount_opt, RESERVATION);
773
774 if (!parse_options ((char *) data, sbi))
775 goto failed_mount;
776
777 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
778 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
779 MS_POSIXACL : 0);
780
781 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
782 EXT2_MOUNT_XIP if not */
783
784 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
785 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
786 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
787 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
788 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
789 "running e2fsck is recommended\n");
790 /*
791 * Check feature flags regardless of the revision level, since we
792 * previously didn't change the revision level when setting the flags,
793 * so there is a chance incompat flags are set on a rev 0 filesystem.
794 */
795 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
796 if (features) {
797 printk("EXT2-fs: %s: couldn't mount because of "
798 "unsupported optional features (%x).\n",
799 sb->s_id, le32_to_cpu(features));
800 goto failed_mount;
801 }
802 if (!(sb->s_flags & MS_RDONLY) &&
803 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
804 printk("EXT2-fs: %s: couldn't mount RDWR because of "
805 "unsupported optional features (%x).\n",
806 sb->s_id, le32_to_cpu(features));
807 goto failed_mount;
808 }
809
810 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
811
812 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
813 if (!silent)
814 printk("XIP: Unsupported blocksize\n");
815 goto failed_mount;
816 }
817
818 /* If the blocksize doesn't match, re-read the thing.. */
819 if (sb->s_blocksize != blocksize) {
820 brelse(bh);
821
822 if (!sb_set_blocksize(sb, blocksize)) {
823 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
824 goto failed_sbi;
825 }
826
827 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
828 offset = (sb_block*BLOCK_SIZE) % blocksize;
829 bh = sb_bread(sb, logic_sb_block);
830 if(!bh) {
831 printk("EXT2-fs: Couldn't read superblock on "
832 "2nd try.\n");
833 goto failed_sbi;
834 }
835 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
836 sbi->s_es = es;
837 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
838 printk ("EXT2-fs: Magic mismatch, very weird !\n");
839 goto failed_mount;
840 }
841 }
842
843 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
844
845 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
846 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
847 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
848 } else {
849 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
850 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
851 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
852 (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
853 (sbi->s_inode_size > blocksize)) {
854 printk ("EXT2-fs: unsupported inode size: %d\n",
855 sbi->s_inode_size);
856 goto failed_mount;
857 }
858 }
859
860 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
861 le32_to_cpu(es->s_log_frag_size);
862 if (sbi->s_frag_size == 0)
863 goto cantfind_ext2;
864 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
865
866 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
867 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
868 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
869
870 if (EXT2_INODE_SIZE(sb) == 0)
871 goto cantfind_ext2;
872 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
873 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
874 goto cantfind_ext2;
875 sbi->s_itb_per_group = sbi->s_inodes_per_group /
876 sbi->s_inodes_per_block;
877 sbi->s_desc_per_block = sb->s_blocksize /
878 sizeof (struct ext2_group_desc);
879 sbi->s_sbh = bh;
880 sbi->s_mount_state = le16_to_cpu(es->s_state);
881 sbi->s_addr_per_block_bits =
882 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
883 sbi->s_desc_per_block_bits =
884 ilog2 (EXT2_DESC_PER_BLOCK(sb));
885
886 if (sb->s_magic != EXT2_SUPER_MAGIC)
887 goto cantfind_ext2;
888
889 if (sb->s_blocksize != bh->b_size) {
890 if (!silent)
891 printk ("VFS: Unsupported blocksize on dev "
892 "%s.\n", sb->s_id);
893 goto failed_mount;
894 }
895
896 if (sb->s_blocksize != sbi->s_frag_size) {
897 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
898 sbi->s_frag_size, sb->s_blocksize);
899 goto failed_mount;
900 }
901
902 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
903 printk ("EXT2-fs: #blocks per group too big: %lu\n",
904 sbi->s_blocks_per_group);
905 goto failed_mount;
906 }
907 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
908 printk ("EXT2-fs: #fragments per group too big: %lu\n",
909 sbi->s_frags_per_group);
910 goto failed_mount;
911 }
912 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
913 printk ("EXT2-fs: #inodes per group too big: %lu\n",
914 sbi->s_inodes_per_group);
915 goto failed_mount;
916 }
917
918 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
919 goto cantfind_ext2;
920 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
921 le32_to_cpu(es->s_first_data_block) - 1)
922 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
923 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
924 EXT2_DESC_PER_BLOCK(sb);
925 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
926 if (sbi->s_group_desc == NULL) {
927 printk ("EXT2-fs: not enough memory\n");
928 goto failed_mount;
929 }
930 bgl_lock_init(&sbi->s_blockgroup_lock);
931 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
932 if (!sbi->s_debts) {
933 printk ("EXT2-fs: not enough memory\n");
934 goto failed_mount_group_desc;
935 }
936 for (i = 0; i < db_count; i++) {
937 block = descriptor_loc(sb, logic_sb_block, i);
938 sbi->s_group_desc[i] = sb_bread(sb, block);
939 if (!sbi->s_group_desc[i]) {
940 for (j = 0; j < i; j++)
941 brelse (sbi->s_group_desc[j]);
942 printk ("EXT2-fs: unable to read group descriptors\n");
943 goto failed_mount_group_desc;
944 }
945 }
946 if (!ext2_check_descriptors (sb)) {
947 printk ("EXT2-fs: group descriptors corrupted!\n");
948 goto failed_mount2;
949 }
950 sbi->s_gdb_count = db_count;
951 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
952 spin_lock_init(&sbi->s_next_gen_lock);
953
954 /* per fileystem reservation list head & lock */
955 spin_lock_init(&sbi->s_rsv_window_lock);
956 sbi->s_rsv_window_root = RB_ROOT;
957 /*
958 * Add a single, static dummy reservation to the start of the
959 * reservation window list --- it gives us a placeholder for
960 * append-at-start-of-list which makes the allocation logic
961 * _much_ simpler.
962 */
963 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
964 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
965 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
966 sbi->s_rsv_window_head.rsv_goal_size = 0;
967 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
968
969 percpu_counter_init(&sbi->s_freeblocks_counter,
970 ext2_count_free_blocks(sb));
971 percpu_counter_init(&sbi->s_freeinodes_counter,
972 ext2_count_free_inodes(sb));
973 percpu_counter_init(&sbi->s_dirs_counter,
974 ext2_count_dirs(sb));
975 /*
976 * set up enough so that it can read an inode
977 */
978 sb->s_op = &ext2_sops;
979 sb->s_export_op = &ext2_export_ops;
980 sb->s_xattr = ext2_xattr_handlers;
981 root = iget(sb, EXT2_ROOT_INO);
982 sb->s_root = d_alloc_root(root);
983 if (!sb->s_root) {
984 iput(root);
985 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
986 goto failed_mount3;
987 }
988 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
989 dput(sb->s_root);
990 sb->s_root = NULL;
991 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
992 goto failed_mount3;
993 }
994 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
995 ext2_warning(sb, __FUNCTION__,
996 "mounting ext3 filesystem as ext2");
997 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
998 return 0;
999
1000 cantfind_ext2:
1001 if (!silent)
1002 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1003 sb->s_id);
1004 goto failed_mount;
1005 failed_mount3:
1006 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1007 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1008 percpu_counter_destroy(&sbi->s_dirs_counter);
1009 failed_mount2:
1010 for (i = 0; i < db_count; i++)
1011 brelse(sbi->s_group_desc[i]);
1012 failed_mount_group_desc:
1013 kfree(sbi->s_group_desc);
1014 kfree(sbi->s_debts);
1015 failed_mount:
1016 brelse(bh);
1017 failed_sbi:
1018 sb->s_fs_info = NULL;
1019 kfree(sbi);
1020 return -EINVAL;
1021 }
1022
1023 static void ext2_clear_super_error(struct super_block *sb)
1024 {
1025 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1026
1027 if (buffer_write_io_error(sbh)) {
1028 /*
1029 * Oh, dear. A previous attempt to write the
1030 * superblock failed. This could happen because the
1031 * USB device was yanked out. Or it could happen to
1032 * be a transient write error and maybe the block will
1033 * be remapped. Nothing we can do but to retry the
1034 * write and hope for the best.
1035 */
1036 printk(KERN_ERR "EXT2-fs: %s previous I/O error to "
1037 "superblock detected", sb->s_id);
1038 clear_buffer_write_io_error(sbh);
1039 set_buffer_uptodate(sbh);
1040 }
1041 }
1042
1043 static void ext2_commit_super (struct super_block * sb,
1044 struct ext2_super_block * es)
1045 {
1046 ext2_clear_super_error(sb);
1047 es->s_wtime = cpu_to_le32(get_seconds());
1048 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1049 sb->s_dirt = 0;
1050 }
1051
1052 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1053 {
1054 ext2_clear_super_error(sb);
1055 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1056 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1057 es->s_wtime = cpu_to_le32(get_seconds());
1058 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1059 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1060 sb->s_dirt = 0;
1061 }
1062
1063 /*
1064 * In the second extended file system, it is not necessary to
1065 * write the super block since we use a mapping of the
1066 * disk super block in a buffer.
1067 *
1068 * However, this function is still used to set the fs valid
1069 * flags to 0. We need to set this flag to 0 since the fs
1070 * may have been checked while mounted and e2fsck may have
1071 * set s_state to EXT2_VALID_FS after some corrections.
1072 */
1073
1074 void ext2_write_super (struct super_block * sb)
1075 {
1076 struct ext2_super_block * es;
1077 lock_kernel();
1078 if (!(sb->s_flags & MS_RDONLY)) {
1079 es = EXT2_SB(sb)->s_es;
1080
1081 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
1082 ext2_debug ("setting valid to 0\n");
1083 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
1084 ~EXT2_VALID_FS);
1085 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1086 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1087 es->s_mtime = cpu_to_le32(get_seconds());
1088 ext2_sync_super(sb, es);
1089 } else
1090 ext2_commit_super (sb, es);
1091 }
1092 sb->s_dirt = 0;
1093 unlock_kernel();
1094 }
1095
1096 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1097 {
1098 struct ext2_sb_info * sbi = EXT2_SB(sb);
1099 struct ext2_super_block * es;
1100 unsigned long old_mount_opt = sbi->s_mount_opt;
1101 struct ext2_mount_options old_opts;
1102 unsigned long old_sb_flags;
1103 int err;
1104
1105 /* Store the old options */
1106 old_sb_flags = sb->s_flags;
1107 old_opts.s_mount_opt = sbi->s_mount_opt;
1108 old_opts.s_resuid = sbi->s_resuid;
1109 old_opts.s_resgid = sbi->s_resgid;
1110
1111 /*
1112 * Allow the "check" option to be passed as a remount option.
1113 */
1114 if (!parse_options (data, sbi)) {
1115 err = -EINVAL;
1116 goto restore_opts;
1117 }
1118
1119 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1120 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1121
1122 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1123 EXT2_MOUNT_XIP if not */
1124
1125 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1126 printk("XIP: Unsupported blocksize\n");
1127 err = -EINVAL;
1128 goto restore_opts;
1129 }
1130
1131 es = sbi->s_es;
1132 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1133 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1134 invalidate_inodes(sb))
1135 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
1136 "xip remain in cache (no functional problem)");
1137 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1138 return 0;
1139 if (*flags & MS_RDONLY) {
1140 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1141 !(sbi->s_mount_state & EXT2_VALID_FS))
1142 return 0;
1143 /*
1144 * OK, we are remounting a valid rw partition rdonly, so set
1145 * the rdonly flag and then mark the partition as valid again.
1146 */
1147 es->s_state = cpu_to_le16(sbi->s_mount_state);
1148 es->s_mtime = cpu_to_le32(get_seconds());
1149 } else {
1150 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1151 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1152 if (ret) {
1153 printk("EXT2-fs: %s: couldn't remount RDWR because of "
1154 "unsupported optional features (%x).\n",
1155 sb->s_id, le32_to_cpu(ret));
1156 err = -EROFS;
1157 goto restore_opts;
1158 }
1159 /*
1160 * Mounting a RDONLY partition read-write, so reread and
1161 * store the current valid flag. (It may have been changed
1162 * by e2fsck since we originally mounted the partition.)
1163 */
1164 sbi->s_mount_state = le16_to_cpu(es->s_state);
1165 if (!ext2_setup_super (sb, es, 0))
1166 sb->s_flags &= ~MS_RDONLY;
1167 }
1168 ext2_sync_super(sb, es);
1169 return 0;
1170 restore_opts:
1171 sbi->s_mount_opt = old_opts.s_mount_opt;
1172 sbi->s_resuid = old_opts.s_resuid;
1173 sbi->s_resgid = old_opts.s_resgid;
1174 sb->s_flags = old_sb_flags;
1175 return err;
1176 }
1177
1178 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1179 {
1180 struct super_block *sb = dentry->d_sb;
1181 struct ext2_sb_info *sbi = EXT2_SB(sb);
1182 struct ext2_super_block *es = sbi->s_es;
1183 u64 fsid;
1184
1185 if (test_opt (sb, MINIX_DF))
1186 sbi->s_overhead_last = 0;
1187 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1188 unsigned long i, overhead = 0;
1189 smp_rmb();
1190
1191 /*
1192 * Compute the overhead (FS structures). This is constant
1193 * for a given filesystem unless the number of block groups
1194 * changes so we cache the previous value until it does.
1195 */
1196
1197 /*
1198 * All of the blocks before first_data_block are
1199 * overhead
1200 */
1201 overhead = le32_to_cpu(es->s_first_data_block);
1202
1203 /*
1204 * Add the overhead attributed to the superblock and
1205 * block group descriptors. If the sparse superblocks
1206 * feature is turned on, then not all groups have this.
1207 */
1208 for (i = 0; i < sbi->s_groups_count; i++)
1209 overhead += ext2_bg_has_super(sb, i) +
1210 ext2_bg_num_gdb(sb, i);
1211
1212 /*
1213 * Every block group has an inode bitmap, a block
1214 * bitmap, and an inode table.
1215 */
1216 overhead += (sbi->s_groups_count *
1217 (2 + sbi->s_itb_per_group));
1218 sbi->s_overhead_last = overhead;
1219 smp_wmb();
1220 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1221 }
1222
1223 buf->f_type = EXT2_SUPER_MAGIC;
1224 buf->f_bsize = sb->s_blocksize;
1225 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1226 buf->f_bfree = ext2_count_free_blocks(sb);
1227 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1228 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1229 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1230 buf->f_bavail = 0;
1231 buf->f_files = le32_to_cpu(es->s_inodes_count);
1232 buf->f_ffree = ext2_count_free_inodes(sb);
1233 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1234 buf->f_namelen = EXT2_NAME_LEN;
1235 fsid = le64_to_cpup((void *)es->s_uuid) ^
1236 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1237 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1238 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1239 return 0;
1240 }
1241
1242 static int ext2_get_sb(struct file_system_type *fs_type,
1243 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1244 {
1245 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1246 }
1247
1248 #ifdef CONFIG_QUOTA
1249
1250 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1251 * acquiring the locks... As quota files are never truncated and quota code
1252 * itself serializes the operations (and noone else should touch the files)
1253 * we don't have to be afraid of races */
1254 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1255 size_t len, loff_t off)
1256 {
1257 struct inode *inode = sb_dqopt(sb)->files[type];
1258 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1259 int err = 0;
1260 int offset = off & (sb->s_blocksize - 1);
1261 int tocopy;
1262 size_t toread;
1263 struct buffer_head tmp_bh;
1264 struct buffer_head *bh;
1265 loff_t i_size = i_size_read(inode);
1266
1267 if (off > i_size)
1268 return 0;
1269 if (off+len > i_size)
1270 len = i_size-off;
1271 toread = len;
1272 while (toread > 0) {
1273 tocopy = sb->s_blocksize - offset < toread ?
1274 sb->s_blocksize - offset : toread;
1275
1276 tmp_bh.b_state = 0;
1277 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1278 if (err < 0)
1279 return err;
1280 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1281 memset(data, 0, tocopy);
1282 else {
1283 bh = sb_bread(sb, tmp_bh.b_blocknr);
1284 if (!bh)
1285 return -EIO;
1286 memcpy(data, bh->b_data+offset, tocopy);
1287 brelse(bh);
1288 }
1289 offset = 0;
1290 toread -= tocopy;
1291 data += tocopy;
1292 blk++;
1293 }
1294 return len;
1295 }
1296
1297 /* Write to quotafile */
1298 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1299 const char *data, size_t len, loff_t off)
1300 {
1301 struct inode *inode = sb_dqopt(sb)->files[type];
1302 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1303 int err = 0;
1304 int offset = off & (sb->s_blocksize - 1);
1305 int tocopy;
1306 size_t towrite = len;
1307 struct buffer_head tmp_bh;
1308 struct buffer_head *bh;
1309
1310 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1311 while (towrite > 0) {
1312 tocopy = sb->s_blocksize - offset < towrite ?
1313 sb->s_blocksize - offset : towrite;
1314
1315 tmp_bh.b_state = 0;
1316 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1317 if (err < 0)
1318 goto out;
1319 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1320 bh = sb_bread(sb, tmp_bh.b_blocknr);
1321 else
1322 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1323 if (!bh) {
1324 err = -EIO;
1325 goto out;
1326 }
1327 lock_buffer(bh);
1328 memcpy(bh->b_data+offset, data, tocopy);
1329 flush_dcache_page(bh->b_page);
1330 set_buffer_uptodate(bh);
1331 mark_buffer_dirty(bh);
1332 unlock_buffer(bh);
1333 brelse(bh);
1334 offset = 0;
1335 towrite -= tocopy;
1336 data += tocopy;
1337 blk++;
1338 }
1339 out:
1340 if (len == towrite)
1341 return err;
1342 if (inode->i_size < off+len-towrite)
1343 i_size_write(inode, off+len-towrite);
1344 inode->i_version++;
1345 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1346 mark_inode_dirty(inode);
1347 mutex_unlock(&inode->i_mutex);
1348 return len - towrite;
1349 }
1350
1351 #endif
1352
1353 static struct file_system_type ext2_fs_type = {
1354 .owner = THIS_MODULE,
1355 .name = "ext2",
1356 .get_sb = ext2_get_sb,
1357 .kill_sb = kill_block_super,
1358 .fs_flags = FS_REQUIRES_DEV,
1359 };
1360
1361 static int __init init_ext2_fs(void)
1362 {
1363 int err = init_ext2_xattr();
1364 if (err)
1365 return err;
1366 err = init_inodecache();
1367 if (err)
1368 goto out1;
1369 err = register_filesystem(&ext2_fs_type);
1370 if (err)
1371 goto out;
1372 return 0;
1373 out:
1374 destroy_inodecache();
1375 out1:
1376 exit_ext2_xattr();
1377 return err;
1378 }
1379
1380 static void __exit exit_ext2_fs(void)
1381 {
1382 unregister_filesystem(&ext2_fs_type);
1383 destroy_inodecache();
1384 exit_ext2_xattr();
1385 }
1386
1387 module_init(init_ext2_fs)
1388 module_exit(exit_ext2_fs)
Tomato firmware and modifications.