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x86: introduce kernel/head32.c
[linux-2.6/mini2440.git] / fs / ext2 / super.c
blob088b011bb97e2882892a766a94b9bcac2894d984
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 <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);
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
45 void ext2_error (struct super_block * sb, const char * function,
46 const char * fmt, ...)
47 {
48 va_list args;
49 struct ext2_sb_info *sbi = EXT2_SB(sb);
50 struct ext2_super_block *es = sbi->s_es;
51
52 if (!(sb->s_flags & MS_RDONLY)) {
53 sbi->s_mount_state |= EXT2_ERROR_FS;
54 es->s_state =
55 cpu_to_le16(le16_to_cpu(es->s_state) | 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, __FUNCTION__,
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(struct kmem_cache * cachep, 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 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 es->s_mnt_count=cpu_to_le16(le16_to_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 unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
626 unsigned long last_block;
627
628 ext2_debug ("Checking group descriptors");
629
630 for (i = 0; i < sbi->s_groups_count; i++) {
631 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
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 first_block += EXT2_BLOCKS_PER_GROUP(sb);
668 }
669 return 1;
670 }
671
672 /*
673 * Maximal file size. There is a direct, and {,double-,triple-}indirect
674 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
675 * We need to be 1 filesystem block less than the 2^32 sector limit.
676 */
677 static loff_t ext2_max_size(int bits)
678 {
679 loff_t res = EXT2_NDIR_BLOCKS;
680 int meta_blocks;
681 loff_t upper_limit;
682
683 /* This is calculated to be the largest file size for a
684 * dense, file such that the total number of
685 * sectors in the file, including data and all indirect blocks,
686 * does not exceed 2^32 -1
687 * __u32 i_blocks representing the total number of
688 * 512 bytes blocks of the file
689 */
690 upper_limit = (1LL << 32) - 1;
691
692 /* total blocks in file system block size */
693 upper_limit >>= (bits - 9);
694
695
696 /* indirect blocks */
697 meta_blocks = 1;
698 /* double indirect blocks */
699 meta_blocks += 1 + (1LL << (bits-2));
700 /* tripple indirect blocks */
701 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
702
703 upper_limit -= meta_blocks;
704 upper_limit <<= bits;
705
706 res += 1LL << (bits-2);
707 res += 1LL << (2*(bits-2));
708 res += 1LL << (3*(bits-2));
709 res <<= bits;
710 if (res > upper_limit)
711 res = upper_limit;
712
713 if (res > MAX_LFS_FILESIZE)
714 res = MAX_LFS_FILESIZE;
715
716 return res;
717 }
718
719 static unsigned long descriptor_loc(struct super_block *sb,
720 unsigned long logic_sb_block,
721 int nr)
722 {
723 struct ext2_sb_info *sbi = EXT2_SB(sb);
724 unsigned long bg, first_data_block, first_meta_bg;
725 int has_super = 0;
726
727 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
728 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
729
730 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
731 nr < first_meta_bg)
732 return (logic_sb_block + nr + 1);
733 bg = sbi->s_desc_per_block * nr;
734 if (ext2_bg_has_super(sb, bg))
735 has_super = 1;
736 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
737 }
738
739 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
740 {
741 struct buffer_head * bh;
742 struct ext2_sb_info * sbi;
743 struct ext2_super_block * es;
744 struct inode *root;
745 unsigned long block;
746 unsigned long sb_block = get_sb_block(&data);
747 unsigned long logic_sb_block;
748 unsigned long offset = 0;
749 unsigned long def_mount_opts;
750 long ret = -EINVAL;
751 int blocksize = BLOCK_SIZE;
752 int db_count;
753 int i, j;
754 __le32 features;
755 int err;
756
757 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
758 if (!sbi)
759 return -ENOMEM;
760 sb->s_fs_info = sbi;
761 sbi->s_sb_block = sb_block;
762
763 /*
764 * See what the current blocksize for the device is, and
765 * use that as the blocksize. Otherwise (or if the blocksize
766 * is smaller than the default) use the default.
767 * This is important for devices that have a hardware
768 * sectorsize that is larger than the default.
769 */
770 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
771 if (!blocksize) {
772 printk ("EXT2-fs: unable to set blocksize\n");
773 goto failed_sbi;
774 }
775
776 /*
777 * If the superblock doesn't start on a hardware sector boundary,
778 * calculate the offset.
779 */
780 if (blocksize != BLOCK_SIZE) {
781 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
782 offset = (sb_block*BLOCK_SIZE) % blocksize;
783 } else {
784 logic_sb_block = sb_block;
785 }
786
787 if (!(bh = sb_bread(sb, logic_sb_block))) {
788 printk ("EXT2-fs: unable to read superblock\n");
789 goto failed_sbi;
790 }
791 /*
792 * Note: s_es must be initialized as soon as possible because
793 * some ext2 macro-instructions depend on its value
794 */
795 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
796 sbi->s_es = es;
797 sb->s_magic = le16_to_cpu(es->s_magic);
798
799 if (sb->s_magic != EXT2_SUPER_MAGIC)
800 goto cantfind_ext2;
801
802 /* Set defaults before we parse the mount options */
803 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
804 if (def_mount_opts & EXT2_DEFM_DEBUG)
805 set_opt(sbi->s_mount_opt, DEBUG);
806 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
807 set_opt(sbi->s_mount_opt, GRPID);
808 if (def_mount_opts & EXT2_DEFM_UID16)
809 set_opt(sbi->s_mount_opt, NO_UID32);
810 #ifdef CONFIG_EXT2_FS_XATTR
811 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
812 set_opt(sbi->s_mount_opt, XATTR_USER);
813 #endif
814 #ifdef CONFIG_EXT2_FS_POSIX_ACL
815 if (def_mount_opts & EXT2_DEFM_ACL)
816 set_opt(sbi->s_mount_opt, POSIX_ACL);
817 #endif
818
819 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
820 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
821 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
822 set_opt(sbi->s_mount_opt, ERRORS_CONT);
823 else
824 set_opt(sbi->s_mount_opt, ERRORS_RO);
825
826 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
827 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
828
829 set_opt(sbi->s_mount_opt, RESERVATION);
830
831 if (!parse_options ((char *) data, sbi))
832 goto failed_mount;
833
834 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
835 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
836 MS_POSIXACL : 0);
837
838 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
839 EXT2_MOUNT_XIP if not */
840
841 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
842 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
843 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
844 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
845 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
846 "running e2fsck is recommended\n");
847 /*
848 * Check feature flags regardless of the revision level, since we
849 * previously didn't change the revision level when setting the flags,
850 * so there is a chance incompat flags are set on a rev 0 filesystem.
851 */
852 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
853 if (features) {
854 printk("EXT2-fs: %s: couldn't mount because of "
855 "unsupported optional features (%x).\n",
856 sb->s_id, le32_to_cpu(features));
857 goto failed_mount;
858 }
859 if (!(sb->s_flags & MS_RDONLY) &&
860 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
861 printk("EXT2-fs: %s: couldn't mount RDWR because of "
862 "unsupported optional features (%x).\n",
863 sb->s_id, le32_to_cpu(features));
864 goto failed_mount;
865 }
866
867 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
868
869 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
870 if (!silent)
871 printk("XIP: Unsupported blocksize\n");
872 goto failed_mount;
873 }
874
875 /* If the blocksize doesn't match, re-read the thing.. */
876 if (sb->s_blocksize != blocksize) {
877 brelse(bh);
878
879 if (!sb_set_blocksize(sb, blocksize)) {
880 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
881 goto failed_sbi;
882 }
883
884 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
885 offset = (sb_block*BLOCK_SIZE) % blocksize;
886 bh = sb_bread(sb, logic_sb_block);
887 if(!bh) {
888 printk("EXT2-fs: Couldn't read superblock on "
889 "2nd try.\n");
890 goto failed_sbi;
891 }
892 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
893 sbi->s_es = es;
894 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
895 printk ("EXT2-fs: Magic mismatch, very weird !\n");
896 goto failed_mount;
897 }
898 }
899
900 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
901
902 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
903 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
904 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
905 } else {
906 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
907 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
908 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
909 !is_power_of_2(sbi->s_inode_size) ||
910 (sbi->s_inode_size > blocksize)) {
911 printk ("EXT2-fs: unsupported inode size: %d\n",
912 sbi->s_inode_size);
913 goto failed_mount;
914 }
915 }
916
917 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
918 le32_to_cpu(es->s_log_frag_size);
919 if (sbi->s_frag_size == 0)
920 goto cantfind_ext2;
921 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
922
923 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
924 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
925 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
926
927 if (EXT2_INODE_SIZE(sb) == 0)
928 goto cantfind_ext2;
929 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
930 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
931 goto cantfind_ext2;
932 sbi->s_itb_per_group = sbi->s_inodes_per_group /
933 sbi->s_inodes_per_block;
934 sbi->s_desc_per_block = sb->s_blocksize /
935 sizeof (struct ext2_group_desc);
936 sbi->s_sbh = bh;
937 sbi->s_mount_state = le16_to_cpu(es->s_state);
938 sbi->s_addr_per_block_bits =
939 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
940 sbi->s_desc_per_block_bits =
941 ilog2 (EXT2_DESC_PER_BLOCK(sb));
942
943 if (sb->s_magic != EXT2_SUPER_MAGIC)
944 goto cantfind_ext2;
945
946 if (sb->s_blocksize != bh->b_size) {
947 if (!silent)
948 printk ("VFS: Unsupported blocksize on dev "
949 "%s.\n", sb->s_id);
950 goto failed_mount;
951 }
952
953 if (sb->s_blocksize != sbi->s_frag_size) {
954 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
955 sbi->s_frag_size, sb->s_blocksize);
956 goto failed_mount;
957 }
958
959 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
960 printk ("EXT2-fs: #blocks per group too big: %lu\n",
961 sbi->s_blocks_per_group);
962 goto failed_mount;
963 }
964 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
965 printk ("EXT2-fs: #fragments per group too big: %lu\n",
966 sbi->s_frags_per_group);
967 goto failed_mount;
968 }
969 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
970 printk ("EXT2-fs: #inodes per group too big: %lu\n",
971 sbi->s_inodes_per_group);
972 goto failed_mount;
973 }
974
975 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
976 goto cantfind_ext2;
977 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
978 le32_to_cpu(es->s_first_data_block) - 1)
979 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
980 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
981 EXT2_DESC_PER_BLOCK(sb);
982 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
983 if (sbi->s_group_desc == NULL) {
984 printk ("EXT2-fs: not enough memory\n");
985 goto failed_mount;
986 }
987 bgl_lock_init(&sbi->s_blockgroup_lock);
988 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
989 if (!sbi->s_debts) {
990 printk ("EXT2-fs: not enough memory\n");
991 goto failed_mount_group_desc;
992 }
993 for (i = 0; i < db_count; i++) {
994 block = descriptor_loc(sb, logic_sb_block, i);
995 sbi->s_group_desc[i] = sb_bread(sb, block);
996 if (!sbi->s_group_desc[i]) {
997 for (j = 0; j < i; j++)
998 brelse (sbi->s_group_desc[j]);
999 printk ("EXT2-fs: unable to read group descriptors\n");
1000 goto failed_mount_group_desc;
1001 }
1002 }
1003 if (!ext2_check_descriptors (sb)) {
1004 printk ("EXT2-fs: group descriptors corrupted!\n");
1005 goto failed_mount2;
1006 }
1007 sbi->s_gdb_count = db_count;
1008 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1009 spin_lock_init(&sbi->s_next_gen_lock);
1010
1011 /* per fileystem reservation list head & lock */
1012 spin_lock_init(&sbi->s_rsv_window_lock);
1013 sbi->s_rsv_window_root = RB_ROOT;
1014 /*
1015 * Add a single, static dummy reservation to the start of the
1016 * reservation window list --- it gives us a placeholder for
1017 * append-at-start-of-list which makes the allocation logic
1018 * _much_ simpler.
1019 */
1020 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1021 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1022 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1023 sbi->s_rsv_window_head.rsv_goal_size = 0;
1024 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1025
1026 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1027 ext2_count_free_blocks(sb));
1028 if (!err) {
1029 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1030 ext2_count_free_inodes(sb));
1031 }
1032 if (!err) {
1033 err = percpu_counter_init(&sbi->s_dirs_counter,
1034 ext2_count_dirs(sb));
1035 }
1036 if (err) {
1037 printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1038 goto failed_mount3;
1039 }
1040 /*
1041 * set up enough so that it can read an inode
1042 */
1043 sb->s_op = &ext2_sops;
1044 sb->s_export_op = &ext2_export_ops;
1045 sb->s_xattr = ext2_xattr_handlers;
1046 root = ext2_iget(sb, EXT2_ROOT_INO);
1047 if (IS_ERR(root)) {
1048 ret = PTR_ERR(root);
1049 goto failed_mount3;
1050 }
1051 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1052 iput(root);
1053 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1054 goto failed_mount3;
1055 }
1056
1057 sb->s_root = d_alloc_root(root);
1058 if (!sb->s_root) {
1059 iput(root);
1060 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1061 ret = -ENOMEM;
1062 goto failed_mount3;
1063 }
1064 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1065 ext2_warning(sb, __FUNCTION__,
1066 "mounting ext3 filesystem as ext2");
1067 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1068 return 0;
1069
1070 cantfind_ext2:
1071 if (!silent)
1072 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1073 sb->s_id);
1074 goto failed_mount;
1075 failed_mount3:
1076 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1077 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1078 percpu_counter_destroy(&sbi->s_dirs_counter);
1079 failed_mount2:
1080 for (i = 0; i < db_count; i++)
1081 brelse(sbi->s_group_desc[i]);
1082 failed_mount_group_desc:
1083 kfree(sbi->s_group_desc);
1084 kfree(sbi->s_debts);
1085 failed_mount:
1086 brelse(bh);
1087 failed_sbi:
1088 sb->s_fs_info = NULL;
1089 kfree(sbi);
1090 return ret;
1091 }
1092
1093 static void ext2_commit_super (struct super_block * sb,
1094 struct ext2_super_block * es)
1095 {
1096 es->s_wtime = cpu_to_le32(get_seconds());
1097 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1098 sb->s_dirt = 0;
1099 }
1100
1101 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1102 {
1103 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1104 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1105 es->s_wtime = cpu_to_le32(get_seconds());
1106 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1107 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1108 sb->s_dirt = 0;
1109 }
1110
1111 /*
1112 * In the second extended file system, it is not necessary to
1113 * write the super block since we use a mapping of the
1114 * disk super block in a buffer.
1115 *
1116 * However, this function is still used to set the fs valid
1117 * flags to 0. We need to set this flag to 0 since the fs
1118 * may have been checked while mounted and e2fsck may have
1119 * set s_state to EXT2_VALID_FS after some corrections.
1120 */
1121
1122 void ext2_write_super (struct super_block * sb)
1123 {
1124 struct ext2_super_block * es;
1125 lock_kernel();
1126 if (!(sb->s_flags & MS_RDONLY)) {
1127 es = EXT2_SB(sb)->s_es;
1128
1129 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
1130 ext2_debug ("setting valid to 0\n");
1131 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
1132 ~EXT2_VALID_FS);
1133 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1134 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1135 es->s_mtime = cpu_to_le32(get_seconds());
1136 ext2_sync_super(sb, es);
1137 } else
1138 ext2_commit_super (sb, es);
1139 }
1140 sb->s_dirt = 0;
1141 unlock_kernel();
1142 }
1143
1144 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1145 {
1146 struct ext2_sb_info * sbi = EXT2_SB(sb);
1147 struct ext2_super_block * es;
1148 unsigned long old_mount_opt = sbi->s_mount_opt;
1149 struct ext2_mount_options old_opts;
1150 unsigned long old_sb_flags;
1151 int err;
1152
1153 /* Store the old options */
1154 old_sb_flags = sb->s_flags;
1155 old_opts.s_mount_opt = sbi->s_mount_opt;
1156 old_opts.s_resuid = sbi->s_resuid;
1157 old_opts.s_resgid = sbi->s_resgid;
1158
1159 /*
1160 * Allow the "check" option to be passed as a remount option.
1161 */
1162 if (!parse_options (data, sbi)) {
1163 err = -EINVAL;
1164 goto restore_opts;
1165 }
1166
1167 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1168 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1169
1170 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1171 EXT2_MOUNT_XIP if not */
1172
1173 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1174 printk("XIP: Unsupported blocksize\n");
1175 err = -EINVAL;
1176 goto restore_opts;
1177 }
1178
1179 es = sbi->s_es;
1180 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1181 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1182 invalidate_inodes(sb))
1183 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
1184 "xip remain in cache (no functional problem)");
1185 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1186 return 0;
1187 if (*flags & MS_RDONLY) {
1188 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1189 !(sbi->s_mount_state & EXT2_VALID_FS))
1190 return 0;
1191 /*
1192 * OK, we are remounting a valid rw partition rdonly, so set
1193 * the rdonly flag and then mark the partition as valid again.
1194 */
1195 es->s_state = cpu_to_le16(sbi->s_mount_state);
1196 es->s_mtime = cpu_to_le32(get_seconds());
1197 } else {
1198 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1199 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1200 if (ret) {
1201 printk("EXT2-fs: %s: couldn't remount RDWR because of "
1202 "unsupported optional features (%x).\n",
1203 sb->s_id, le32_to_cpu(ret));
1204 err = -EROFS;
1205 goto restore_opts;
1206 }
1207 /*
1208 * Mounting a RDONLY partition read-write, so reread and
1209 * store the current valid flag. (It may have been changed
1210 * by e2fsck since we originally mounted the partition.)
1211 */
1212 sbi->s_mount_state = le16_to_cpu(es->s_state);
1213 if (!ext2_setup_super (sb, es, 0))
1214 sb->s_flags &= ~MS_RDONLY;
1215 }
1216 ext2_sync_super(sb, es);
1217 return 0;
1218 restore_opts:
1219 sbi->s_mount_opt = old_opts.s_mount_opt;
1220 sbi->s_resuid = old_opts.s_resuid;
1221 sbi->s_resgid = old_opts.s_resgid;
1222 sb->s_flags = old_sb_flags;
1223 return err;
1224 }
1225
1226 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1227 {
1228 struct super_block *sb = dentry->d_sb;
1229 struct ext2_sb_info *sbi = EXT2_SB(sb);
1230 struct ext2_super_block *es = sbi->s_es;
1231 u64 fsid;
1232
1233 if (test_opt (sb, MINIX_DF))
1234 sbi->s_overhead_last = 0;
1235 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1236 unsigned long i, overhead = 0;
1237 smp_rmb();
1238
1239 /*
1240 * Compute the overhead (FS structures). This is constant
1241 * for a given filesystem unless the number of block groups
1242 * changes so we cache the previous value until it does.
1243 */
1244
1245 /*
1246 * All of the blocks before first_data_block are
1247 * overhead
1248 */
1249 overhead = le32_to_cpu(es->s_first_data_block);
1250
1251 /*
1252 * Add the overhead attributed to the superblock and
1253 * block group descriptors. If the sparse superblocks
1254 * feature is turned on, then not all groups have this.
1255 */
1256 for (i = 0; i < sbi->s_groups_count; i++)
1257 overhead += ext2_bg_has_super(sb, i) +
1258 ext2_bg_num_gdb(sb, i);
1259
1260 /*
1261 * Every block group has an inode bitmap, a block
1262 * bitmap, and an inode table.
1263 */
1264 overhead += (sbi->s_groups_count *
1265 (2 + sbi->s_itb_per_group));
1266 sbi->s_overhead_last = overhead;
1267 smp_wmb();
1268 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1269 }
1270
1271 buf->f_type = EXT2_SUPER_MAGIC;
1272 buf->f_bsize = sb->s_blocksize;
1273 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1274 buf->f_bfree = ext2_count_free_blocks(sb);
1275 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1276 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1277 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1278 buf->f_bavail = 0;
1279 buf->f_files = le32_to_cpu(es->s_inodes_count);
1280 buf->f_ffree = ext2_count_free_inodes(sb);
1281 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1282 buf->f_namelen = EXT2_NAME_LEN;
1283 fsid = le64_to_cpup((void *)es->s_uuid) ^
1284 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1285 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1286 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1287 return 0;
1288 }
1289
1290 static int ext2_get_sb(struct file_system_type *fs_type,
1291 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1292 {
1293 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1294 }
1295
1296 #ifdef CONFIG_QUOTA
1297
1298 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1299 * acquiring the locks... As quota files are never truncated and quota code
1300 * itself serializes the operations (and noone else should touch the files)
1301 * we don't have to be afraid of races */
1302 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1303 size_t len, loff_t off)
1304 {
1305 struct inode *inode = sb_dqopt(sb)->files[type];
1306 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1307 int err = 0;
1308 int offset = off & (sb->s_blocksize - 1);
1309 int tocopy;
1310 size_t toread;
1311 struct buffer_head tmp_bh;
1312 struct buffer_head *bh;
1313 loff_t i_size = i_size_read(inode);
1314
1315 if (off > i_size)
1316 return 0;
1317 if (off+len > i_size)
1318 len = i_size-off;
1319 toread = len;
1320 while (toread > 0) {
1321 tocopy = sb->s_blocksize - offset < toread ?
1322 sb->s_blocksize - offset : toread;
1323
1324 tmp_bh.b_state = 0;
1325 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1326 if (err < 0)
1327 return err;
1328 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1329 memset(data, 0, tocopy);
1330 else {
1331 bh = sb_bread(sb, tmp_bh.b_blocknr);
1332 if (!bh)
1333 return -EIO;
1334 memcpy(data, bh->b_data+offset, tocopy);
1335 brelse(bh);
1336 }
1337 offset = 0;
1338 toread -= tocopy;
1339 data += tocopy;
1340 blk++;
1341 }
1342 return len;
1343 }
1344
1345 /* Write to quotafile */
1346 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1347 const char *data, size_t len, loff_t off)
1348 {
1349 struct inode *inode = sb_dqopt(sb)->files[type];
1350 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1351 int err = 0;
1352 int offset = off & (sb->s_blocksize - 1);
1353 int tocopy;
1354 size_t towrite = len;
1355 struct buffer_head tmp_bh;
1356 struct buffer_head *bh;
1357
1358 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1359 while (towrite > 0) {
1360 tocopy = sb->s_blocksize - offset < towrite ?
1361 sb->s_blocksize - offset : towrite;
1362
1363 tmp_bh.b_state = 0;
1364 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1365 if (err < 0)
1366 goto out;
1367 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1368 bh = sb_bread(sb, tmp_bh.b_blocknr);
1369 else
1370 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1371 if (!bh) {
1372 err = -EIO;
1373 goto out;
1374 }
1375 lock_buffer(bh);
1376 memcpy(bh->b_data+offset, data, tocopy);
1377 flush_dcache_page(bh->b_page);
1378 set_buffer_uptodate(bh);
1379 mark_buffer_dirty(bh);
1380 unlock_buffer(bh);
1381 brelse(bh);
1382 offset = 0;
1383 towrite -= tocopy;
1384 data += tocopy;
1385 blk++;
1386 }
1387 out:
1388 if (len == towrite)
1389 return err;
1390 if (inode->i_size < off+len-towrite)
1391 i_size_write(inode, off+len-towrite);
1392 inode->i_version++;
1393 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1394 mark_inode_dirty(inode);
1395 mutex_unlock(&inode->i_mutex);
1396 return len - towrite;
1397 }
1398
1399 #endif
1400
1401 static struct file_system_type ext2_fs_type = {
1402 .owner = THIS_MODULE,
1403 .name = "ext2",
1404 .get_sb = ext2_get_sb,
1405 .kill_sb = kill_block_super,
1406 .fs_flags = FS_REQUIRES_DEV,
1407 };
1408
1409 static int __init init_ext2_fs(void)
1410 {
1411 int err = init_ext2_xattr();
1412 if (err)
1413 return err;
1414 err = init_inodecache();
1415 if (err)
1416 goto out1;
1417 err = register_filesystem(&ext2_fs_type);
1418 if (err)
1419 goto out;
1420 return 0;
1421 out:
1422 destroy_inodecache();
1423 out1:
1424 exit_ext2_xattr();
1425 return err;
1426 }
1427
1428 static void __exit exit_ext2_fs(void)
1429 {
1430 unregister_filesystem(&ext2_fs_type);
1431 destroy_inodecache();
1432 exit_ext2_xattr();
1433 }
1434
1435 module_init(init_ext2_fs)
1436 module_exit(exit_ext2_fs)
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