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airport: remove useless return in a function returning void
[linux/fpc-iii.git] / fs / ext2 / super.c
blob647cd888ac87c8933a168e3ff05ca6dbe201e786
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 <linux/log2.h>
34 #include <linux/quotaops.h>
35 #include <asm/uaccess.h>
36 #include "ext2.h"
37 #include "xattr.h"
38 #include "acl.h"
39 #include "xip.h"
40
41 static void ext2_sync_super(struct super_block *sb,
42 struct ext2_super_block *es);
43 static int ext2_remount (struct super_block * sb, int * flags, char * data);
44 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
45
46 void ext2_error (struct super_block * sb, const char * function,
47 const char * fmt, ...)
48 {
49 va_list args;
50 struct ext2_sb_info *sbi = EXT2_SB(sb);
51 struct ext2_super_block *es = sbi->s_es;
52
53 if (!(sb->s_flags & MS_RDONLY)) {
54 sbi->s_mount_state |= EXT2_ERROR_FS;
55 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
56 ext2_sync_super(sb, es);
57 }
58
59 va_start(args, fmt);
60 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
61 vprintk(fmt, args);
62 printk("\n");
63 va_end(args);
64
65 if (test_opt(sb, ERRORS_PANIC))
66 panic("EXT2-fs panic from previous error\n");
67 if (test_opt(sb, ERRORS_RO)) {
68 printk("Remounting filesystem read-only\n");
69 sb->s_flags |= MS_RDONLY;
70 }
71 }
72
73 void ext2_warning (struct super_block * sb, const char * function,
74 const char * fmt, ...)
75 {
76 va_list args;
77
78 va_start(args, fmt);
79 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
80 sb->s_id, function);
81 vprintk(fmt, args);
82 printk("\n");
83 va_end(args);
84 }
85
86 void ext2_update_dynamic_rev(struct super_block *sb)
87 {
88 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
89
90 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
91 return;
92
93 ext2_warning(sb, __func__,
94 "updating to rev %d because of new feature flag, "
95 "running e2fsck is recommended",
96 EXT2_DYNAMIC_REV);
97
98 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
99 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
100 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
101 /* leave es->s_feature_*compat flags alone */
102 /* es->s_uuid will be set by e2fsck if empty */
103
104 /*
105 * The rest of the superblock fields should be zero, and if not it
106 * means they are likely already in use, so leave them alone. We
107 * can leave it up to e2fsck to clean up any inconsistencies there.
108 */
109 }
110
111 static void ext2_put_super (struct super_block * sb)
112 {
113 int db_count;
114 int i;
115 struct ext2_sb_info *sbi = EXT2_SB(sb);
116
117 ext2_xattr_put_super(sb);
118 if (!(sb->s_flags & MS_RDONLY)) {
119 struct ext2_super_block *es = sbi->s_es;
120
121 es->s_state = cpu_to_le16(sbi->s_mount_state);
122 ext2_sync_super(sb, es);
123 }
124 db_count = sbi->s_gdb_count;
125 for (i = 0; i < db_count; i++)
126 if (sbi->s_group_desc[i])
127 brelse (sbi->s_group_desc[i]);
128 kfree(sbi->s_group_desc);
129 kfree(sbi->s_debts);
130 percpu_counter_destroy(&sbi->s_freeblocks_counter);
131 percpu_counter_destroy(&sbi->s_freeinodes_counter);
132 percpu_counter_destroy(&sbi->s_dirs_counter);
133 brelse (sbi->s_sbh);
134 sb->s_fs_info = NULL;
135 kfree(sbi);
136
137 return;
138 }
139
140 static struct kmem_cache * ext2_inode_cachep;
141
142 static struct inode *ext2_alloc_inode(struct super_block *sb)
143 {
144 struct ext2_inode_info *ei;
145 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
146 if (!ei)
147 return NULL;
148 #ifdef CONFIG_EXT2_FS_POSIX_ACL
149 ei->i_acl = EXT2_ACL_NOT_CACHED;
150 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
151 #endif
152 ei->i_block_alloc_info = NULL;
153 ei->vfs_inode.i_version = 1;
154 return &ei->vfs_inode;
155 }
156
157 static void ext2_destroy_inode(struct inode *inode)
158 {
159 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
160 }
161
162 static void init_once(void *foo)
163 {
164 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
165
166 rwlock_init(&ei->i_meta_lock);
167 #ifdef CONFIG_EXT2_FS_XATTR
168 init_rwsem(&ei->xattr_sem);
169 #endif
170 mutex_init(&ei->truncate_mutex);
171 inode_init_once(&ei->vfs_inode);
172 }
173
174 static int init_inodecache(void)
175 {
176 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
177 sizeof(struct ext2_inode_info),
178 0, (SLAB_RECLAIM_ACCOUNT|
179 SLAB_MEM_SPREAD),
180 init_once);
181 if (ext2_inode_cachep == NULL)
182 return -ENOMEM;
183 return 0;
184 }
185
186 static void destroy_inodecache(void)
187 {
188 kmem_cache_destroy(ext2_inode_cachep);
189 }
190
191 static void ext2_clear_inode(struct inode *inode)
192 {
193 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
194 #ifdef CONFIG_EXT2_FS_POSIX_ACL
195 struct ext2_inode_info *ei = EXT2_I(inode);
196
197 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
198 posix_acl_release(ei->i_acl);
199 ei->i_acl = EXT2_ACL_NOT_CACHED;
200 }
201 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
202 posix_acl_release(ei->i_default_acl);
203 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
204 }
205 #endif
206 ext2_discard_reservation(inode);
207 EXT2_I(inode)->i_block_alloc_info = NULL;
208 if (unlikely(rsv))
209 kfree(rsv);
210 }
211
212 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
213 {
214 struct super_block *sb = vfs->mnt_sb;
215 struct ext2_sb_info *sbi = EXT2_SB(sb);
216 struct ext2_super_block *es = sbi->s_es;
217 unsigned long def_mount_opts;
218
219 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
220
221 if (sbi->s_sb_block != 1)
222 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
223 if (test_opt(sb, MINIX_DF))
224 seq_puts(seq, ",minixdf");
225 if (test_opt(sb, GRPID))
226 seq_puts(seq, ",grpid");
227 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
228 seq_puts(seq, ",nogrpid");
229 if (sbi->s_resuid != EXT2_DEF_RESUID ||
230 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
231 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
232 }
233 if (sbi->s_resgid != EXT2_DEF_RESGID ||
234 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
235 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
236 }
237 if (test_opt(sb, ERRORS_RO)) {
238 int def_errors = le16_to_cpu(es->s_errors);
239
240 if (def_errors == EXT2_ERRORS_PANIC ||
241 def_errors == EXT2_ERRORS_CONTINUE) {
242 seq_puts(seq, ",errors=remount-ro");
243 }
244 }
245 if (test_opt(sb, ERRORS_CONT))
246 seq_puts(seq, ",errors=continue");
247 if (test_opt(sb, ERRORS_PANIC))
248 seq_puts(seq, ",errors=panic");
249 if (test_opt(sb, NO_UID32))
250 seq_puts(seq, ",nouid32");
251 if (test_opt(sb, DEBUG))
252 seq_puts(seq, ",debug");
253 if (test_opt(sb, OLDALLOC))
254 seq_puts(seq, ",oldalloc");
255
256 #ifdef CONFIG_EXT2_FS_XATTR
257 if (test_opt(sb, XATTR_USER))
258 seq_puts(seq, ",user_xattr");
259 if (!test_opt(sb, XATTR_USER) &&
260 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
261 seq_puts(seq, ",nouser_xattr");
262 }
263 #endif
264
265 #ifdef CONFIG_EXT2_FS_POSIX_ACL
266 if (test_opt(sb, POSIX_ACL))
267 seq_puts(seq, ",acl");
268 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
269 seq_puts(seq, ",noacl");
270 #endif
271
272 if (test_opt(sb, NOBH))
273 seq_puts(seq, ",nobh");
274
275 #if defined(CONFIG_QUOTA)
276 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
277 seq_puts(seq, ",usrquota");
278
279 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
280 seq_puts(seq, ",grpquota");
281 #endif
282
283 #if defined(CONFIG_EXT2_FS_XIP)
284 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
285 seq_puts(seq, ",xip");
286 #endif
287
288 if (!test_opt(sb, RESERVATION))
289 seq_puts(seq, ",noreservation");
290
291 return 0;
292 }
293
294 #ifdef CONFIG_QUOTA
295 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
296 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
297 #endif
298
299 static const struct super_operations ext2_sops = {
300 .alloc_inode = ext2_alloc_inode,
301 .destroy_inode = ext2_destroy_inode,
302 .write_inode = ext2_write_inode,
303 .delete_inode = ext2_delete_inode,
304 .put_super = ext2_put_super,
305 .write_super = ext2_write_super,
306 .statfs = ext2_statfs,
307 .remount_fs = ext2_remount,
308 .clear_inode = ext2_clear_inode,
309 .show_options = ext2_show_options,
310 #ifdef CONFIG_QUOTA
311 .quota_read = ext2_quota_read,
312 .quota_write = ext2_quota_write,
313 #endif
314 };
315
316 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
317 u64 ino, u32 generation)
318 {
319 struct inode *inode;
320
321 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
322 return ERR_PTR(-ESTALE);
323 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
324 return ERR_PTR(-ESTALE);
325
326 /* iget isn't really right if the inode is currently unallocated!!
327 * ext2_read_inode currently does appropriate checks, but
328 * it might be "neater" to call ext2_get_inode first and check
329 * if the inode is valid.....
330 */
331 inode = ext2_iget(sb, ino);
332 if (IS_ERR(inode))
333 return ERR_CAST(inode);
334 if (generation && inode->i_generation != generation) {
335 /* we didn't find the right inode.. */
336 iput(inode);
337 return ERR_PTR(-ESTALE);
338 }
339 return inode;
340 }
341
342 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
343 int fh_len, int fh_type)
344 {
345 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
346 ext2_nfs_get_inode);
347 }
348
349 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
350 int fh_len, int fh_type)
351 {
352 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
353 ext2_nfs_get_inode);
354 }
355
356 /* Yes, most of these are left as NULL!!
357 * A NULL value implies the default, which works with ext2-like file
358 * systems, but can be improved upon.
359 * Currently only get_parent is required.
360 */
361 static const struct export_operations ext2_export_ops = {
362 .fh_to_dentry = ext2_fh_to_dentry,
363 .fh_to_parent = ext2_fh_to_parent,
364 .get_parent = ext2_get_parent,
365 };
366
367 static unsigned long get_sb_block(void **data)
368 {
369 unsigned long sb_block;
370 char *options = (char *) *data;
371
372 if (!options || strncmp(options, "sb=", 3) != 0)
373 return 1; /* Default location */
374 options += 3;
375 sb_block = simple_strtoul(options, &options, 0);
376 if (*options && *options != ',') {
377 printk("EXT2-fs: Invalid sb specification: %s\n",
378 (char *) *data);
379 return 1;
380 }
381 if (*options == ',')
382 options++;
383 *data = (void *) options;
384 return sb_block;
385 }
386
387 enum {
388 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
389 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
390 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
391 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
392 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
393 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
394 };
395
396 static const match_table_t tokens = {
397 {Opt_bsd_df, "bsddf"},
398 {Opt_minix_df, "minixdf"},
399 {Opt_grpid, "grpid"},
400 {Opt_grpid, "bsdgroups"},
401 {Opt_nogrpid, "nogrpid"},
402 {Opt_nogrpid, "sysvgroups"},
403 {Opt_resgid, "resgid=%u"},
404 {Opt_resuid, "resuid=%u"},
405 {Opt_sb, "sb=%u"},
406 {Opt_err_cont, "errors=continue"},
407 {Opt_err_panic, "errors=panic"},
408 {Opt_err_ro, "errors=remount-ro"},
409 {Opt_nouid32, "nouid32"},
410 {Opt_nocheck, "check=none"},
411 {Opt_nocheck, "nocheck"},
412 {Opt_debug, "debug"},
413 {Opt_oldalloc, "oldalloc"},
414 {Opt_orlov, "orlov"},
415 {Opt_nobh, "nobh"},
416 {Opt_user_xattr, "user_xattr"},
417 {Opt_nouser_xattr, "nouser_xattr"},
418 {Opt_acl, "acl"},
419 {Opt_noacl, "noacl"},
420 {Opt_xip, "xip"},
421 {Opt_grpquota, "grpquota"},
422 {Opt_ignore, "noquota"},
423 {Opt_quota, "quota"},
424 {Opt_usrquota, "usrquota"},
425 {Opt_reservation, "reservation"},
426 {Opt_noreservation, "noreservation"},
427 {Opt_err, NULL}
428 };
429
430 static int parse_options (char * options,
431 struct ext2_sb_info *sbi)
432 {
433 char * p;
434 substring_t args[MAX_OPT_ARGS];
435 int option;
436
437 if (!options)
438 return 1;
439
440 while ((p = strsep (&options, ",")) != NULL) {
441 int token;
442 if (!*p)
443 continue;
444
445 token = match_token(p, tokens, args);
446 switch (token) {
447 case Opt_bsd_df:
448 clear_opt (sbi->s_mount_opt, MINIX_DF);
449 break;
450 case Opt_minix_df:
451 set_opt (sbi->s_mount_opt, MINIX_DF);
452 break;
453 case Opt_grpid:
454 set_opt (sbi->s_mount_opt, GRPID);
455 break;
456 case Opt_nogrpid:
457 clear_opt (sbi->s_mount_opt, GRPID);
458 break;
459 case Opt_resuid:
460 if (match_int(&args[0], &option))
461 return 0;
462 sbi->s_resuid = option;
463 break;
464 case Opt_resgid:
465 if (match_int(&args[0], &option))
466 return 0;
467 sbi->s_resgid = option;
468 break;
469 case Opt_sb:
470 /* handled by get_sb_block() instead of here */
471 /* *sb_block = match_int(&args[0]); */
472 break;
473 case Opt_err_panic:
474 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
475 clear_opt (sbi->s_mount_opt, ERRORS_RO);
476 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
477 break;
478 case Opt_err_ro:
479 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
480 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
481 set_opt (sbi->s_mount_opt, ERRORS_RO);
482 break;
483 case Opt_err_cont:
484 clear_opt (sbi->s_mount_opt, ERRORS_RO);
485 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
486 set_opt (sbi->s_mount_opt, ERRORS_CONT);
487 break;
488 case Opt_nouid32:
489 set_opt (sbi->s_mount_opt, NO_UID32);
490 break;
491 case Opt_nocheck:
492 clear_opt (sbi->s_mount_opt, CHECK);
493 break;
494 case Opt_debug:
495 set_opt (sbi->s_mount_opt, DEBUG);
496 break;
497 case Opt_oldalloc:
498 set_opt (sbi->s_mount_opt, OLDALLOC);
499 break;
500 case Opt_orlov:
501 clear_opt (sbi->s_mount_opt, OLDALLOC);
502 break;
503 case Opt_nobh:
504 set_opt (sbi->s_mount_opt, NOBH);
505 break;
506 #ifdef CONFIG_EXT2_FS_XATTR
507 case Opt_user_xattr:
508 set_opt (sbi->s_mount_opt, XATTR_USER);
509 break;
510 case Opt_nouser_xattr:
511 clear_opt (sbi->s_mount_opt, XATTR_USER);
512 break;
513 #else
514 case Opt_user_xattr:
515 case Opt_nouser_xattr:
516 printk("EXT2 (no)user_xattr options not supported\n");
517 break;
518 #endif
519 #ifdef CONFIG_EXT2_FS_POSIX_ACL
520 case Opt_acl:
521 set_opt(sbi->s_mount_opt, POSIX_ACL);
522 break;
523 case Opt_noacl:
524 clear_opt(sbi->s_mount_opt, POSIX_ACL);
525 break;
526 #else
527 case Opt_acl:
528 case Opt_noacl:
529 printk("EXT2 (no)acl options not supported\n");
530 break;
531 #endif
532 case Opt_xip:
533 #ifdef CONFIG_EXT2_FS_XIP
534 set_opt (sbi->s_mount_opt, XIP);
535 #else
536 printk("EXT2 xip option not supported\n");
537 #endif
538 break;
539
540 #if defined(CONFIG_QUOTA)
541 case Opt_quota:
542 case Opt_usrquota:
543 set_opt(sbi->s_mount_opt, USRQUOTA);
544 break;
545
546 case Opt_grpquota:
547 set_opt(sbi->s_mount_opt, GRPQUOTA);
548 break;
549 #else
550 case Opt_quota:
551 case Opt_usrquota:
552 case Opt_grpquota:
553 printk(KERN_ERR
554 "EXT2-fs: quota operations not supported.\n");
555
556 break;
557 #endif
558
559 case Opt_reservation:
560 set_opt(sbi->s_mount_opt, RESERVATION);
561 printk("reservations ON\n");
562 break;
563 case Opt_noreservation:
564 clear_opt(sbi->s_mount_opt, RESERVATION);
565 printk("reservations OFF\n");
566 break;
567 case Opt_ignore:
568 break;
569 default:
570 return 0;
571 }
572 }
573 return 1;
574 }
575
576 static int ext2_setup_super (struct super_block * sb,
577 struct ext2_super_block * es,
578 int read_only)
579 {
580 int res = 0;
581 struct ext2_sb_info *sbi = EXT2_SB(sb);
582
583 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
584 printk ("EXT2-fs warning: revision level too high, "
585 "forcing read-only mode\n");
586 res = MS_RDONLY;
587 }
588 if (read_only)
589 return res;
590 if (!(sbi->s_mount_state & EXT2_VALID_FS))
591 printk ("EXT2-fs warning: mounting unchecked fs, "
592 "running e2fsck is recommended\n");
593 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
594 printk ("EXT2-fs warning: mounting fs with errors, "
595 "running e2fsck is recommended\n");
596 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
597 le16_to_cpu(es->s_mnt_count) >=
598 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
599 printk ("EXT2-fs warning: maximal mount count reached, "
600 "running e2fsck is recommended\n");
601 else if (le32_to_cpu(es->s_checkinterval) &&
602 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
603 printk ("EXT2-fs warning: checktime reached, "
604 "running e2fsck is recommended\n");
605 if (!le16_to_cpu(es->s_max_mnt_count))
606 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
607 le16_add_cpu(&es->s_mnt_count, 1);
608 ext2_write_super(sb);
609 if (test_opt (sb, DEBUG))
610 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
611 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
612 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
613 sbi->s_frag_size,
614 sbi->s_groups_count,
615 EXT2_BLOCKS_PER_GROUP(sb),
616 EXT2_INODES_PER_GROUP(sb),
617 sbi->s_mount_opt);
618 return res;
619 }
620
621 static int ext2_check_descriptors(struct super_block *sb)
622 {
623 int i;
624 struct ext2_sb_info *sbi = EXT2_SB(sb);
625
626 ext2_debug ("Checking group descriptors");
627
628 for (i = 0; i < sbi->s_groups_count; i++) {
629 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
630 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
631 ext2_fsblk_t last_block;
632
633 if (i == sbi->s_groups_count - 1)
634 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
635 else
636 last_block = first_block +
637 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
638
639 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
640 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
641 {
642 ext2_error (sb, "ext2_check_descriptors",
643 "Block bitmap for group %d"
644 " not in group (block %lu)!",
645 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
646 return 0;
647 }
648 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
649 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
650 {
651 ext2_error (sb, "ext2_check_descriptors",
652 "Inode bitmap for group %d"
653 " not in group (block %lu)!",
654 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
655 return 0;
656 }
657 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
658 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
659 last_block)
660 {
661 ext2_error (sb, "ext2_check_descriptors",
662 "Inode table for group %d"
663 " not in group (block %lu)!",
664 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
665 return 0;
666 }
667 }
668 return 1;
669 }
670
671 /*
672 * Maximal file size. There is a direct, and {,double-,triple-}indirect
673 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
674 * We need to be 1 filesystem block less than the 2^32 sector limit.
675 */
676 static loff_t ext2_max_size(int bits)
677 {
678 loff_t res = EXT2_NDIR_BLOCKS;
679 int meta_blocks;
680 loff_t upper_limit;
681
682 /* This is calculated to be the largest file size for a
683 * dense, file such that the total number of
684 * sectors in the file, including data and all indirect blocks,
685 * does not exceed 2^32 -1
686 * __u32 i_blocks representing the total number of
687 * 512 bytes blocks of the file
688 */
689 upper_limit = (1LL << 32) - 1;
690
691 /* total blocks in file system block size */
692 upper_limit >>= (bits - 9);
693
694
695 /* indirect blocks */
696 meta_blocks = 1;
697 /* double indirect blocks */
698 meta_blocks += 1 + (1LL << (bits-2));
699 /* tripple indirect blocks */
700 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
701
702 upper_limit -= meta_blocks;
703 upper_limit <<= bits;
704
705 res += 1LL << (bits-2);
706 res += 1LL << (2*(bits-2));
707 res += 1LL << (3*(bits-2));
708 res <<= bits;
709 if (res > upper_limit)
710 res = upper_limit;
711
712 if (res > MAX_LFS_FILESIZE)
713 res = MAX_LFS_FILESIZE;
714
715 return res;
716 }
717
718 static unsigned long descriptor_loc(struct super_block *sb,
719 unsigned long logic_sb_block,
720 int nr)
721 {
722 struct ext2_sb_info *sbi = EXT2_SB(sb);
723 unsigned long bg, first_meta_bg;
724 int has_super = 0;
725
726 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
727
728 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
729 nr < first_meta_bg)
730 return (logic_sb_block + nr + 1);
731 bg = sbi->s_desc_per_block * nr;
732 if (ext2_bg_has_super(sb, bg))
733 has_super = 1;
734
735 return ext2_group_first_block_no(sb, bg) + has_super;
736 }
737
738 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
739 {
740 struct buffer_head * bh;
741 struct ext2_sb_info * sbi;
742 struct ext2_super_block * es;
743 struct inode *root;
744 unsigned long block;
745 unsigned long sb_block = get_sb_block(&data);
746 unsigned long logic_sb_block;
747 unsigned long offset = 0;
748 unsigned long def_mount_opts;
749 long ret = -EINVAL;
750 int blocksize = BLOCK_SIZE;
751 int db_count;
752 int i, j;
753 __le32 features;
754 int err;
755
756 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
757 if (!sbi)
758 return -ENOMEM;
759 sb->s_fs_info = sbi;
760 sbi->s_sb_block = sb_block;
761
762 /*
763 * See what the current blocksize for the device is, and
764 * use that as the blocksize. Otherwise (or if the blocksize
765 * is smaller than the default) use the default.
766 * This is important for devices that have a hardware
767 * sectorsize that is larger than the default.
768 */
769 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
770 if (!blocksize) {
771 printk ("EXT2-fs: unable to set blocksize\n");
772 goto failed_sbi;
773 }
774
775 /*
776 * If the superblock doesn't start on a hardware sector boundary,
777 * calculate the offset.
778 */
779 if (blocksize != BLOCK_SIZE) {
780 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
781 offset = (sb_block*BLOCK_SIZE) % blocksize;
782 } else {
783 logic_sb_block = sb_block;
784 }
785
786 if (!(bh = sb_bread(sb, logic_sb_block))) {
787 printk ("EXT2-fs: unable to read superblock\n");
788 goto failed_sbi;
789 }
790 /*
791 * Note: s_es must be initialized as soon as possible because
792 * some ext2 macro-instructions depend on its value
793 */
794 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
795 sbi->s_es = es;
796 sb->s_magic = le16_to_cpu(es->s_magic);
797
798 if (sb->s_magic != EXT2_SUPER_MAGIC)
799 goto cantfind_ext2;
800
801 /* Set defaults before we parse the mount options */
802 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
803 if (def_mount_opts & EXT2_DEFM_DEBUG)
804 set_opt(sbi->s_mount_opt, DEBUG);
805 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
806 set_opt(sbi->s_mount_opt, GRPID);
807 if (def_mount_opts & EXT2_DEFM_UID16)
808 set_opt(sbi->s_mount_opt, NO_UID32);
809 #ifdef CONFIG_EXT2_FS_XATTR
810 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
811 set_opt(sbi->s_mount_opt, XATTR_USER);
812 #endif
813 #ifdef CONFIG_EXT2_FS_POSIX_ACL
814 if (def_mount_opts & EXT2_DEFM_ACL)
815 set_opt(sbi->s_mount_opt, POSIX_ACL);
816 #endif
817
818 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
819 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
820 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
821 set_opt(sbi->s_mount_opt, ERRORS_CONT);
822 else
823 set_opt(sbi->s_mount_opt, ERRORS_RO);
824
825 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
826 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
827
828 set_opt(sbi->s_mount_opt, RESERVATION);
829
830 if (!parse_options ((char *) data, sbi))
831 goto failed_mount;
832
833 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
834 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
835 MS_POSIXACL : 0);
836
837 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
838 EXT2_MOUNT_XIP if not */
839
840 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
841 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
842 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
843 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
844 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
845 "running e2fsck is recommended\n");
846 /*
847 * Check feature flags regardless of the revision level, since we
848 * previously didn't change the revision level when setting the flags,
849 * so there is a chance incompat flags are set on a rev 0 filesystem.
850 */
851 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
852 if (features) {
853 printk("EXT2-fs: %s: couldn't mount because of "
854 "unsupported optional features (%x).\n",
855 sb->s_id, le32_to_cpu(features));
856 goto failed_mount;
857 }
858 if (!(sb->s_flags & MS_RDONLY) &&
859 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
860 printk("EXT2-fs: %s: couldn't mount RDWR because of "
861 "unsupported optional features (%x).\n",
862 sb->s_id, le32_to_cpu(features));
863 goto failed_mount;
864 }
865
866 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
867
868 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
869 if (!silent)
870 printk("XIP: Unsupported blocksize\n");
871 goto failed_mount;
872 }
873
874 /* If the blocksize doesn't match, re-read the thing.. */
875 if (sb->s_blocksize != blocksize) {
876 brelse(bh);
877
878 if (!sb_set_blocksize(sb, blocksize)) {
879 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
880 goto failed_sbi;
881 }
882
883 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
884 offset = (sb_block*BLOCK_SIZE) % blocksize;
885 bh = sb_bread(sb, logic_sb_block);
886 if(!bh) {
887 printk("EXT2-fs: Couldn't read superblock on "
888 "2nd try.\n");
889 goto failed_sbi;
890 }
891 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
892 sbi->s_es = es;
893 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
894 printk ("EXT2-fs: Magic mismatch, very weird !\n");
895 goto failed_mount;
896 }
897 }
898
899 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
900
901 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
902 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
903 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
904 } else {
905 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
906 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
907 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
908 !is_power_of_2(sbi->s_inode_size) ||
909 (sbi->s_inode_size > blocksize)) {
910 printk ("EXT2-fs: unsupported inode size: %d\n",
911 sbi->s_inode_size);
912 goto failed_mount;
913 }
914 }
915
916 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
917 le32_to_cpu(es->s_log_frag_size);
918 if (sbi->s_frag_size == 0)
919 goto cantfind_ext2;
920 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
921
922 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
923 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
924 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
925
926 if (EXT2_INODE_SIZE(sb) == 0)
927 goto cantfind_ext2;
928 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
929 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
930 goto cantfind_ext2;
931 sbi->s_itb_per_group = sbi->s_inodes_per_group /
932 sbi->s_inodes_per_block;
933 sbi->s_desc_per_block = sb->s_blocksize /
934 sizeof (struct ext2_group_desc);
935 sbi->s_sbh = bh;
936 sbi->s_mount_state = le16_to_cpu(es->s_state);
937 sbi->s_addr_per_block_bits =
938 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
939 sbi->s_desc_per_block_bits =
940 ilog2 (EXT2_DESC_PER_BLOCK(sb));
941
942 if (sb->s_magic != EXT2_SUPER_MAGIC)
943 goto cantfind_ext2;
944
945 if (sb->s_blocksize != bh->b_size) {
946 if (!silent)
947 printk ("VFS: Unsupported blocksize on dev "
948 "%s.\n", sb->s_id);
949 goto failed_mount;
950 }
951
952 if (sb->s_blocksize != sbi->s_frag_size) {
953 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
954 sbi->s_frag_size, sb->s_blocksize);
955 goto failed_mount;
956 }
957
958 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
959 printk ("EXT2-fs: #blocks per group too big: %lu\n",
960 sbi->s_blocks_per_group);
961 goto failed_mount;
962 }
963 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
964 printk ("EXT2-fs: #fragments per group too big: %lu\n",
965 sbi->s_frags_per_group);
966 goto failed_mount;
967 }
968 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
969 printk ("EXT2-fs: #inodes per group too big: %lu\n",
970 sbi->s_inodes_per_group);
971 goto failed_mount;
972 }
973
974 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
975 goto cantfind_ext2;
976 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
977 le32_to_cpu(es->s_first_data_block) - 1)
978 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
979 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
980 EXT2_DESC_PER_BLOCK(sb);
981 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
982 if (sbi->s_group_desc == NULL) {
983 printk ("EXT2-fs: not enough memory\n");
984 goto failed_mount;
985 }
986 bgl_lock_init(&sbi->s_blockgroup_lock);
987 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
988 if (!sbi->s_debts) {
989 printk ("EXT2-fs: not enough memory\n");
990 goto failed_mount_group_desc;
991 }
992 for (i = 0; i < db_count; i++) {
993 block = descriptor_loc(sb, logic_sb_block, i);
994 sbi->s_group_desc[i] = sb_bread(sb, block);
995 if (!sbi->s_group_desc[i]) {
996 for (j = 0; j < i; j++)
997 brelse (sbi->s_group_desc[j]);
998 printk ("EXT2-fs: unable to read group descriptors\n");
999 goto failed_mount_group_desc;
1000 }
1001 }
1002 if (!ext2_check_descriptors (sb)) {
1003 printk ("EXT2-fs: group descriptors corrupted!\n");
1004 goto failed_mount2;
1005 }
1006 sbi->s_gdb_count = db_count;
1007 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1008 spin_lock_init(&sbi->s_next_gen_lock);
1009
1010 /* per fileystem reservation list head & lock */
1011 spin_lock_init(&sbi->s_rsv_window_lock);
1012 sbi->s_rsv_window_root = RB_ROOT;
1013 /*
1014 * Add a single, static dummy reservation to the start of the
1015 * reservation window list --- it gives us a placeholder for
1016 * append-at-start-of-list which makes the allocation logic
1017 * _much_ simpler.
1018 */
1019 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1020 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1021 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1022 sbi->s_rsv_window_head.rsv_goal_size = 0;
1023 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1024
1025 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1026 ext2_count_free_blocks(sb));
1027 if (!err) {
1028 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1029 ext2_count_free_inodes(sb));
1030 }
1031 if (!err) {
1032 err = percpu_counter_init(&sbi->s_dirs_counter,
1033 ext2_count_dirs(sb));
1034 }
1035 if (err) {
1036 printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1037 goto failed_mount3;
1038 }
1039 /*
1040 * set up enough so that it can read an inode
1041 */
1042 sb->s_op = &ext2_sops;
1043 sb->s_export_op = &ext2_export_ops;
1044 sb->s_xattr = ext2_xattr_handlers;
1045 root = ext2_iget(sb, EXT2_ROOT_INO);
1046 if (IS_ERR(root)) {
1047 ret = PTR_ERR(root);
1048 goto failed_mount3;
1049 }
1050 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1051 iput(root);
1052 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1053 goto failed_mount3;
1054 }
1055
1056 sb->s_root = d_alloc_root(root);
1057 if (!sb->s_root) {
1058 iput(root);
1059 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1060 ret = -ENOMEM;
1061 goto failed_mount3;
1062 }
1063 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1064 ext2_warning(sb, __func__,
1065 "mounting ext3 filesystem as ext2");
1066 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1067 return 0;
1068
1069 cantfind_ext2:
1070 if (!silent)
1071 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1072 sb->s_id);
1073 goto failed_mount;
1074 failed_mount3:
1075 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1076 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1077 percpu_counter_destroy(&sbi->s_dirs_counter);
1078 failed_mount2:
1079 for (i = 0; i < db_count; i++)
1080 brelse(sbi->s_group_desc[i]);
1081 failed_mount_group_desc:
1082 kfree(sbi->s_group_desc);
1083 kfree(sbi->s_debts);
1084 failed_mount:
1085 brelse(bh);
1086 failed_sbi:
1087 sb->s_fs_info = NULL;
1088 kfree(sbi);
1089 return ret;
1090 }
1091
1092 static void ext2_commit_super (struct super_block * sb,
1093 struct ext2_super_block * es)
1094 {
1095 es->s_wtime = cpu_to_le32(get_seconds());
1096 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1097 sb->s_dirt = 0;
1098 }
1099
1100 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1101 {
1102 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1103 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1104 es->s_wtime = cpu_to_le32(get_seconds());
1105 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1106 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1107 sb->s_dirt = 0;
1108 }
1109
1110 /*
1111 * In the second extended file system, it is not necessary to
1112 * write the super block since we use a mapping of the
1113 * disk super block in a buffer.
1114 *
1115 * However, this function is still used to set the fs valid
1116 * flags to 0. We need to set this flag to 0 since the fs
1117 * may have been checked while mounted and e2fsck may have
1118 * set s_state to EXT2_VALID_FS after some corrections.
1119 */
1120
1121 void ext2_write_super (struct super_block * sb)
1122 {
1123 struct ext2_super_block * es;
1124 lock_kernel();
1125 if (!(sb->s_flags & MS_RDONLY)) {
1126 es = EXT2_SB(sb)->s_es;
1127
1128 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1129 ext2_debug ("setting valid to 0\n");
1130 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1131 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1132 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1133 es->s_mtime = cpu_to_le32(get_seconds());
1134 ext2_sync_super(sb, es);
1135 } else
1136 ext2_commit_super (sb, es);
1137 }
1138 sb->s_dirt = 0;
1139 unlock_kernel();
1140 }
1141
1142 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1143 {
1144 struct ext2_sb_info * sbi = EXT2_SB(sb);
1145 struct ext2_super_block * es;
1146 unsigned long old_mount_opt = sbi->s_mount_opt;
1147 struct ext2_mount_options old_opts;
1148 unsigned long old_sb_flags;
1149 int err;
1150
1151 /* Store the old options */
1152 old_sb_flags = sb->s_flags;
1153 old_opts.s_mount_opt = sbi->s_mount_opt;
1154 old_opts.s_resuid = sbi->s_resuid;
1155 old_opts.s_resgid = sbi->s_resgid;
1156
1157 /*
1158 * Allow the "check" option to be passed as a remount option.
1159 */
1160 if (!parse_options (data, sbi)) {
1161 err = -EINVAL;
1162 goto restore_opts;
1163 }
1164
1165 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1166 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1167
1168 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1169 EXT2_MOUNT_XIP if not */
1170
1171 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1172 printk("XIP: Unsupported blocksize\n");
1173 err = -EINVAL;
1174 goto restore_opts;
1175 }
1176
1177 es = sbi->s_es;
1178 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1179 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1180 invalidate_inodes(sb))
1181 ext2_warning(sb, __func__, "busy inodes while remounting "\
1182 "xip remain in cache (no functional problem)");
1183 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1184 return 0;
1185 if (*flags & MS_RDONLY) {
1186 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1187 !(sbi->s_mount_state & EXT2_VALID_FS))
1188 return 0;
1189 /*
1190 * OK, we are remounting a valid rw partition rdonly, so set
1191 * the rdonly flag and then mark the partition as valid again.
1192 */
1193 es->s_state = cpu_to_le16(sbi->s_mount_state);
1194 es->s_mtime = cpu_to_le32(get_seconds());
1195 } else {
1196 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1197 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1198 if (ret) {
1199 printk("EXT2-fs: %s: couldn't remount RDWR because of "
1200 "unsupported optional features (%x).\n",
1201 sb->s_id, le32_to_cpu(ret));
1202 err = -EROFS;
1203 goto restore_opts;
1204 }
1205 /*
1206 * Mounting a RDONLY partition read-write, so reread and
1207 * store the current valid flag. (It may have been changed
1208 * by e2fsck since we originally mounted the partition.)
1209 */
1210 sbi->s_mount_state = le16_to_cpu(es->s_state);
1211 if (!ext2_setup_super (sb, es, 0))
1212 sb->s_flags &= ~MS_RDONLY;
1213 }
1214 ext2_sync_super(sb, es);
1215 return 0;
1216 restore_opts:
1217 sbi->s_mount_opt = old_opts.s_mount_opt;
1218 sbi->s_resuid = old_opts.s_resuid;
1219 sbi->s_resgid = old_opts.s_resgid;
1220 sb->s_flags = old_sb_flags;
1221 return err;
1222 }
1223
1224 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1225 {
1226 struct super_block *sb = dentry->d_sb;
1227 struct ext2_sb_info *sbi = EXT2_SB(sb);
1228 struct ext2_super_block *es = sbi->s_es;
1229 u64 fsid;
1230
1231 if (test_opt (sb, MINIX_DF))
1232 sbi->s_overhead_last = 0;
1233 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1234 unsigned long i, overhead = 0;
1235 smp_rmb();
1236
1237 /*
1238 * Compute the overhead (FS structures). This is constant
1239 * for a given filesystem unless the number of block groups
1240 * changes so we cache the previous value until it does.
1241 */
1242
1243 /*
1244 * All of the blocks before first_data_block are
1245 * overhead
1246 */
1247 overhead = le32_to_cpu(es->s_first_data_block);
1248
1249 /*
1250 * Add the overhead attributed to the superblock and
1251 * block group descriptors. If the sparse superblocks
1252 * feature is turned on, then not all groups have this.
1253 */
1254 for (i = 0; i < sbi->s_groups_count; i++)
1255 overhead += ext2_bg_has_super(sb, i) +
1256 ext2_bg_num_gdb(sb, i);
1257
1258 /*
1259 * Every block group has an inode bitmap, a block
1260 * bitmap, and an inode table.
1261 */
1262 overhead += (sbi->s_groups_count *
1263 (2 + sbi->s_itb_per_group));
1264 sbi->s_overhead_last = overhead;
1265 smp_wmb();
1266 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1267 }
1268
1269 buf->f_type = EXT2_SUPER_MAGIC;
1270 buf->f_bsize = sb->s_blocksize;
1271 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1272 buf->f_bfree = ext2_count_free_blocks(sb);
1273 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1274 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1275 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1276 buf->f_bavail = 0;
1277 buf->f_files = le32_to_cpu(es->s_inodes_count);
1278 buf->f_ffree = ext2_count_free_inodes(sb);
1279 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1280 buf->f_namelen = EXT2_NAME_LEN;
1281 fsid = le64_to_cpup((void *)es->s_uuid) ^
1282 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1283 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1284 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1285 return 0;
1286 }
1287
1288 static int ext2_get_sb(struct file_system_type *fs_type,
1289 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1290 {
1291 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1292 }
1293
1294 #ifdef CONFIG_QUOTA
1295
1296 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1297 * acquiring the locks... As quota files are never truncated and quota code
1298 * itself serializes the operations (and noone else should touch the files)
1299 * we don't have to be afraid of races */
1300 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1301 size_t len, loff_t off)
1302 {
1303 struct inode *inode = sb_dqopt(sb)->files[type];
1304 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1305 int err = 0;
1306 int offset = off & (sb->s_blocksize - 1);
1307 int tocopy;
1308 size_t toread;
1309 struct buffer_head tmp_bh;
1310 struct buffer_head *bh;
1311 loff_t i_size = i_size_read(inode);
1312
1313 if (off > i_size)
1314 return 0;
1315 if (off+len > i_size)
1316 len = i_size-off;
1317 toread = len;
1318 while (toread > 0) {
1319 tocopy = sb->s_blocksize - offset < toread ?
1320 sb->s_blocksize - offset : toread;
1321
1322 tmp_bh.b_state = 0;
1323 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1324 if (err < 0)
1325 return err;
1326 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1327 memset(data, 0, tocopy);
1328 else {
1329 bh = sb_bread(sb, tmp_bh.b_blocknr);
1330 if (!bh)
1331 return -EIO;
1332 memcpy(data, bh->b_data+offset, tocopy);
1333 brelse(bh);
1334 }
1335 offset = 0;
1336 toread -= tocopy;
1337 data += tocopy;
1338 blk++;
1339 }
1340 return len;
1341 }
1342
1343 /* Write to quotafile */
1344 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1345 const char *data, size_t len, loff_t off)
1346 {
1347 struct inode *inode = sb_dqopt(sb)->files[type];
1348 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1349 int err = 0;
1350 int offset = off & (sb->s_blocksize - 1);
1351 int tocopy;
1352 size_t towrite = len;
1353 struct buffer_head tmp_bh;
1354 struct buffer_head *bh;
1355
1356 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1357 while (towrite > 0) {
1358 tocopy = sb->s_blocksize - offset < towrite ?
1359 sb->s_blocksize - offset : towrite;
1360
1361 tmp_bh.b_state = 0;
1362 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1363 if (err < 0)
1364 goto out;
1365 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1366 bh = sb_bread(sb, tmp_bh.b_blocknr);
1367 else
1368 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1369 if (!bh) {
1370 err = -EIO;
1371 goto out;
1372 }
1373 lock_buffer(bh);
1374 memcpy(bh->b_data+offset, data, tocopy);
1375 flush_dcache_page(bh->b_page);
1376 set_buffer_uptodate(bh);
1377 mark_buffer_dirty(bh);
1378 unlock_buffer(bh);
1379 brelse(bh);
1380 offset = 0;
1381 towrite -= tocopy;
1382 data += tocopy;
1383 blk++;
1384 }
1385 out:
1386 if (len == towrite)
1387 return err;
1388 if (inode->i_size < off+len-towrite)
1389 i_size_write(inode, off+len-towrite);
1390 inode->i_version++;
1391 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1392 mark_inode_dirty(inode);
1393 mutex_unlock(&inode->i_mutex);
1394 return len - towrite;
1395 }
1396
1397 #endif
1398
1399 static struct file_system_type ext2_fs_type = {
1400 .owner = THIS_MODULE,
1401 .name = "ext2",
1402 .get_sb = ext2_get_sb,
1403 .kill_sb = kill_block_super,
1404 .fs_flags = FS_REQUIRES_DEV,
1405 };
1406
1407 static int __init init_ext2_fs(void)
1408 {
1409 int err = init_ext2_xattr();
1410 if (err)
1411 return err;
1412 err = init_inodecache();
1413 if (err)
1414 goto out1;
1415 err = register_filesystem(&ext2_fs_type);
1416 if (err)
1417 goto out;
1418 return 0;
1419 out:
1420 destroy_inodecache();
1421 out1:
1422 exit_ext2_xattr();
1423 return err;
1424 }
1425
1426 static void __exit exit_ext2_fs(void)
1427 {
1428 unregister_filesystem(&ext2_fs_type);
1429 destroy_inodecache();
1430 exit_ext2_xattr();
1431 }
1432
1433 module_init(init_ext2_fs)
1434 module_exit(exit_ext2_fs)
Linux with added FPC-III support