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KVM: Prevent kvm_init from corrupting debugfs structures
[linux-2.6/verdex.git] / fs / ext2 / super.c
blob1a9ffee47d56c545dcc9420680178fb32ea6c374
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 static int ext2_sync_fs(struct super_block *sb, int wait);
46
47 void ext2_error (struct super_block * sb, const char * function,
48 const char * fmt, ...)
49 {
50 va_list args;
51 struct ext2_sb_info *sbi = EXT2_SB(sb);
52 struct ext2_super_block *es = sbi->s_es;
53
54 if (!(sb->s_flags & MS_RDONLY)) {
55 sbi->s_mount_state |= EXT2_ERROR_FS;
56 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
57 ext2_sync_super(sb, es);
58 }
59
60 va_start(args, fmt);
61 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
62 vprintk(fmt, args);
63 printk("\n");
64 va_end(args);
65
66 if (test_opt(sb, ERRORS_PANIC))
67 panic("EXT2-fs panic from previous error\n");
68 if (test_opt(sb, ERRORS_RO)) {
69 printk("Remounting filesystem read-only\n");
70 sb->s_flags |= MS_RDONLY;
71 }
72 }
73
74 void ext2_warning (struct super_block * sb, const char * function,
75 const char * fmt, ...)
76 {
77 va_list args;
78
79 va_start(args, fmt);
80 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
81 sb->s_id, function);
82 vprintk(fmt, args);
83 printk("\n");
84 va_end(args);
85 }
86
87 void ext2_update_dynamic_rev(struct super_block *sb)
88 {
89 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
90
91 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
92 return;
93
94 ext2_warning(sb, __func__,
95 "updating to rev %d because of new feature flag, "
96 "running e2fsck is recommended",
97 EXT2_DYNAMIC_REV);
98
99 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
100 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
101 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
102 /* leave es->s_feature_*compat flags alone */
103 /* es->s_uuid will be set by e2fsck if empty */
104
105 /*
106 * The rest of the superblock fields should be zero, and if not it
107 * means they are likely already in use, so leave them alone. We
108 * can leave it up to e2fsck to clean up any inconsistencies there.
109 */
110 }
111
112 static void ext2_put_super (struct super_block * sb)
113 {
114 int db_count;
115 int i;
116 struct ext2_sb_info *sbi = EXT2_SB(sb);
117
118 lock_kernel();
119
120 if (sb->s_dirt)
121 ext2_write_super(sb);
122
123 ext2_xattr_put_super(sb);
124 if (!(sb->s_flags & MS_RDONLY)) {
125 struct ext2_super_block *es = sbi->s_es;
126
127 es->s_state = cpu_to_le16(sbi->s_mount_state);
128 ext2_sync_super(sb, es);
129 }
130 db_count = sbi->s_gdb_count;
131 for (i = 0; i < db_count; i++)
132 if (sbi->s_group_desc[i])
133 brelse (sbi->s_group_desc[i]);
134 kfree(sbi->s_group_desc);
135 kfree(sbi->s_debts);
136 percpu_counter_destroy(&sbi->s_freeblocks_counter);
137 percpu_counter_destroy(&sbi->s_freeinodes_counter);
138 percpu_counter_destroy(&sbi->s_dirs_counter);
139 brelse (sbi->s_sbh);
140 sb->s_fs_info = NULL;
141 kfree(sbi->s_blockgroup_lock);
142 kfree(sbi);
143
144 unlock_kernel();
145 }
146
147 static struct kmem_cache * ext2_inode_cachep;
148
149 static struct inode *ext2_alloc_inode(struct super_block *sb)
150 {
151 struct ext2_inode_info *ei;
152 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
153 if (!ei)
154 return NULL;
155 ei->i_block_alloc_info = NULL;
156 ei->vfs_inode.i_version = 1;
157 return &ei->vfs_inode;
158 }
159
160 static void ext2_destroy_inode(struct inode *inode)
161 {
162 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
163 }
164
165 static void init_once(void *foo)
166 {
167 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
168
169 rwlock_init(&ei->i_meta_lock);
170 #ifdef CONFIG_EXT2_FS_XATTR
171 init_rwsem(&ei->xattr_sem);
172 #endif
173 mutex_init(&ei->truncate_mutex);
174 inode_init_once(&ei->vfs_inode);
175 }
176
177 static int init_inodecache(void)
178 {
179 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
180 sizeof(struct ext2_inode_info),
181 0, (SLAB_RECLAIM_ACCOUNT|
182 SLAB_MEM_SPREAD),
183 init_once);
184 if (ext2_inode_cachep == NULL)
185 return -ENOMEM;
186 return 0;
187 }
188
189 static void destroy_inodecache(void)
190 {
191 kmem_cache_destroy(ext2_inode_cachep);
192 }
193
194 static void ext2_clear_inode(struct inode *inode)
195 {
196 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
197 ext2_discard_reservation(inode);
198 EXT2_I(inode)->i_block_alloc_info = NULL;
199 if (unlikely(rsv))
200 kfree(rsv);
201 }
202
203 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
204 {
205 struct super_block *sb = vfs->mnt_sb;
206 struct ext2_sb_info *sbi = EXT2_SB(sb);
207 struct ext2_super_block *es = sbi->s_es;
208 unsigned long def_mount_opts;
209
210 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
211
212 if (sbi->s_sb_block != 1)
213 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
214 if (test_opt(sb, MINIX_DF))
215 seq_puts(seq, ",minixdf");
216 if (test_opt(sb, GRPID))
217 seq_puts(seq, ",grpid");
218 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
219 seq_puts(seq, ",nogrpid");
220 if (sbi->s_resuid != EXT2_DEF_RESUID ||
221 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
222 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
223 }
224 if (sbi->s_resgid != EXT2_DEF_RESGID ||
225 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
226 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
227 }
228 if (test_opt(sb, ERRORS_RO)) {
229 int def_errors = le16_to_cpu(es->s_errors);
230
231 if (def_errors == EXT2_ERRORS_PANIC ||
232 def_errors == EXT2_ERRORS_CONTINUE) {
233 seq_puts(seq, ",errors=remount-ro");
234 }
235 }
236 if (test_opt(sb, ERRORS_CONT))
237 seq_puts(seq, ",errors=continue");
238 if (test_opt(sb, ERRORS_PANIC))
239 seq_puts(seq, ",errors=panic");
240 if (test_opt(sb, NO_UID32))
241 seq_puts(seq, ",nouid32");
242 if (test_opt(sb, DEBUG))
243 seq_puts(seq, ",debug");
244 if (test_opt(sb, OLDALLOC))
245 seq_puts(seq, ",oldalloc");
246
247 #ifdef CONFIG_EXT2_FS_XATTR
248 if (test_opt(sb, XATTR_USER))
249 seq_puts(seq, ",user_xattr");
250 if (!test_opt(sb, XATTR_USER) &&
251 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
252 seq_puts(seq, ",nouser_xattr");
253 }
254 #endif
255
256 #ifdef CONFIG_EXT2_FS_POSIX_ACL
257 if (test_opt(sb, POSIX_ACL))
258 seq_puts(seq, ",acl");
259 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
260 seq_puts(seq, ",noacl");
261 #endif
262
263 if (test_opt(sb, NOBH))
264 seq_puts(seq, ",nobh");
265
266 #if defined(CONFIG_QUOTA)
267 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
268 seq_puts(seq, ",usrquota");
269
270 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
271 seq_puts(seq, ",grpquota");
272 #endif
273
274 #if defined(CONFIG_EXT2_FS_XIP)
275 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
276 seq_puts(seq, ",xip");
277 #endif
278
279 if (!test_opt(sb, RESERVATION))
280 seq_puts(seq, ",noreservation");
281
282 return 0;
283 }
284
285 #ifdef CONFIG_QUOTA
286 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
287 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
288 #endif
289
290 static const struct super_operations ext2_sops = {
291 .alloc_inode = ext2_alloc_inode,
292 .destroy_inode = ext2_destroy_inode,
293 .write_inode = ext2_write_inode,
294 .delete_inode = ext2_delete_inode,
295 .put_super = ext2_put_super,
296 .write_super = ext2_write_super,
297 .sync_fs = ext2_sync_fs,
298 .statfs = ext2_statfs,
299 .remount_fs = ext2_remount,
300 .clear_inode = ext2_clear_inode,
301 .show_options = ext2_show_options,
302 #ifdef CONFIG_QUOTA
303 .quota_read = ext2_quota_read,
304 .quota_write = ext2_quota_write,
305 #endif
306 };
307
308 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
309 u64 ino, u32 generation)
310 {
311 struct inode *inode;
312
313 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
314 return ERR_PTR(-ESTALE);
315 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
316 return ERR_PTR(-ESTALE);
317
318 /* iget isn't really right if the inode is currently unallocated!!
319 * ext2_read_inode currently does appropriate checks, but
320 * it might be "neater" to call ext2_get_inode first and check
321 * if the inode is valid.....
322 */
323 inode = ext2_iget(sb, ino);
324 if (IS_ERR(inode))
325 return ERR_CAST(inode);
326 if (generation && inode->i_generation != generation) {
327 /* we didn't find the right inode.. */
328 iput(inode);
329 return ERR_PTR(-ESTALE);
330 }
331 return inode;
332 }
333
334 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
335 int fh_len, int fh_type)
336 {
337 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
338 ext2_nfs_get_inode);
339 }
340
341 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
342 int fh_len, int fh_type)
343 {
344 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
345 ext2_nfs_get_inode);
346 }
347
348 /* Yes, most of these are left as NULL!!
349 * A NULL value implies the default, which works with ext2-like file
350 * systems, but can be improved upon.
351 * Currently only get_parent is required.
352 */
353 static const struct export_operations ext2_export_ops = {
354 .fh_to_dentry = ext2_fh_to_dentry,
355 .fh_to_parent = ext2_fh_to_parent,
356 .get_parent = ext2_get_parent,
357 };
358
359 static unsigned long get_sb_block(void **data)
360 {
361 unsigned long sb_block;
362 char *options = (char *) *data;
363
364 if (!options || strncmp(options, "sb=", 3) != 0)
365 return 1; /* Default location */
366 options += 3;
367 sb_block = simple_strtoul(options, &options, 0);
368 if (*options && *options != ',') {
369 printk("EXT2-fs: Invalid sb specification: %s\n",
370 (char *) *data);
371 return 1;
372 }
373 if (*options == ',')
374 options++;
375 *data = (void *) options;
376 return sb_block;
377 }
378
379 enum {
380 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
381 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
382 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
383 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
384 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
385 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
386 };
387
388 static const match_table_t tokens = {
389 {Opt_bsd_df, "bsddf"},
390 {Opt_minix_df, "minixdf"},
391 {Opt_grpid, "grpid"},
392 {Opt_grpid, "bsdgroups"},
393 {Opt_nogrpid, "nogrpid"},
394 {Opt_nogrpid, "sysvgroups"},
395 {Opt_resgid, "resgid=%u"},
396 {Opt_resuid, "resuid=%u"},
397 {Opt_sb, "sb=%u"},
398 {Opt_err_cont, "errors=continue"},
399 {Opt_err_panic, "errors=panic"},
400 {Opt_err_ro, "errors=remount-ro"},
401 {Opt_nouid32, "nouid32"},
402 {Opt_nocheck, "check=none"},
403 {Opt_nocheck, "nocheck"},
404 {Opt_debug, "debug"},
405 {Opt_oldalloc, "oldalloc"},
406 {Opt_orlov, "orlov"},
407 {Opt_nobh, "nobh"},
408 {Opt_user_xattr, "user_xattr"},
409 {Opt_nouser_xattr, "nouser_xattr"},
410 {Opt_acl, "acl"},
411 {Opt_noacl, "noacl"},
412 {Opt_xip, "xip"},
413 {Opt_grpquota, "grpquota"},
414 {Opt_ignore, "noquota"},
415 {Opt_quota, "quota"},
416 {Opt_usrquota, "usrquota"},
417 {Opt_reservation, "reservation"},
418 {Opt_noreservation, "noreservation"},
419 {Opt_err, NULL}
420 };
421
422 static int parse_options (char * options,
423 struct ext2_sb_info *sbi)
424 {
425 char * p;
426 substring_t args[MAX_OPT_ARGS];
427 int option;
428
429 if (!options)
430 return 1;
431
432 while ((p = strsep (&options, ",")) != NULL) {
433 int token;
434 if (!*p)
435 continue;
436
437 token = match_token(p, tokens, args);
438 switch (token) {
439 case Opt_bsd_df:
440 clear_opt (sbi->s_mount_opt, MINIX_DF);
441 break;
442 case Opt_minix_df:
443 set_opt (sbi->s_mount_opt, MINIX_DF);
444 break;
445 case Opt_grpid:
446 set_opt (sbi->s_mount_opt, GRPID);
447 break;
448 case Opt_nogrpid:
449 clear_opt (sbi->s_mount_opt, GRPID);
450 break;
451 case Opt_resuid:
452 if (match_int(&args[0], &option))
453 return 0;
454 sbi->s_resuid = option;
455 break;
456 case Opt_resgid:
457 if (match_int(&args[0], &option))
458 return 0;
459 sbi->s_resgid = option;
460 break;
461 case Opt_sb:
462 /* handled by get_sb_block() instead of here */
463 /* *sb_block = match_int(&args[0]); */
464 break;
465 case Opt_err_panic:
466 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
467 clear_opt (sbi->s_mount_opt, ERRORS_RO);
468 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
469 break;
470 case Opt_err_ro:
471 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
472 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
473 set_opt (sbi->s_mount_opt, ERRORS_RO);
474 break;
475 case Opt_err_cont:
476 clear_opt (sbi->s_mount_opt, ERRORS_RO);
477 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
478 set_opt (sbi->s_mount_opt, ERRORS_CONT);
479 break;
480 case Opt_nouid32:
481 set_opt (sbi->s_mount_opt, NO_UID32);
482 break;
483 case Opt_nocheck:
484 clear_opt (sbi->s_mount_opt, CHECK);
485 break;
486 case Opt_debug:
487 set_opt (sbi->s_mount_opt, DEBUG);
488 break;
489 case Opt_oldalloc:
490 set_opt (sbi->s_mount_opt, OLDALLOC);
491 break;
492 case Opt_orlov:
493 clear_opt (sbi->s_mount_opt, OLDALLOC);
494 break;
495 case Opt_nobh:
496 set_opt (sbi->s_mount_opt, NOBH);
497 break;
498 #ifdef CONFIG_EXT2_FS_XATTR
499 case Opt_user_xattr:
500 set_opt (sbi->s_mount_opt, XATTR_USER);
501 break;
502 case Opt_nouser_xattr:
503 clear_opt (sbi->s_mount_opt, XATTR_USER);
504 break;
505 #else
506 case Opt_user_xattr:
507 case Opt_nouser_xattr:
508 printk("EXT2 (no)user_xattr options not supported\n");
509 break;
510 #endif
511 #ifdef CONFIG_EXT2_FS_POSIX_ACL
512 case Opt_acl:
513 set_opt(sbi->s_mount_opt, POSIX_ACL);
514 break;
515 case Opt_noacl:
516 clear_opt(sbi->s_mount_opt, POSIX_ACL);
517 break;
518 #else
519 case Opt_acl:
520 case Opt_noacl:
521 printk("EXT2 (no)acl options not supported\n");
522 break;
523 #endif
524 case Opt_xip:
525 #ifdef CONFIG_EXT2_FS_XIP
526 set_opt (sbi->s_mount_opt, XIP);
527 #else
528 printk("EXT2 xip option not supported\n");
529 #endif
530 break;
531
532 #if defined(CONFIG_QUOTA)
533 case Opt_quota:
534 case Opt_usrquota:
535 set_opt(sbi->s_mount_opt, USRQUOTA);
536 break;
537
538 case Opt_grpquota:
539 set_opt(sbi->s_mount_opt, GRPQUOTA);
540 break;
541 #else
542 case Opt_quota:
543 case Opt_usrquota:
544 case Opt_grpquota:
545 printk(KERN_ERR
546 "EXT2-fs: quota operations not supported.\n");
547
548 break;
549 #endif
550
551 case Opt_reservation:
552 set_opt(sbi->s_mount_opt, RESERVATION);
553 printk("reservations ON\n");
554 break;
555 case Opt_noreservation:
556 clear_opt(sbi->s_mount_opt, RESERVATION);
557 printk("reservations OFF\n");
558 break;
559 case Opt_ignore:
560 break;
561 default:
562 return 0;
563 }
564 }
565 return 1;
566 }
567
568 static int ext2_setup_super (struct super_block * sb,
569 struct ext2_super_block * es,
570 int read_only)
571 {
572 int res = 0;
573 struct ext2_sb_info *sbi = EXT2_SB(sb);
574
575 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
576 printk ("EXT2-fs warning: revision level too high, "
577 "forcing read-only mode\n");
578 res = MS_RDONLY;
579 }
580 if (read_only)
581 return res;
582 if (!(sbi->s_mount_state & EXT2_VALID_FS))
583 printk ("EXT2-fs warning: mounting unchecked fs, "
584 "running e2fsck is recommended\n");
585 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
586 printk ("EXT2-fs warning: mounting fs with errors, "
587 "running e2fsck is recommended\n");
588 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
589 le16_to_cpu(es->s_mnt_count) >=
590 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
591 printk ("EXT2-fs warning: maximal mount count reached, "
592 "running e2fsck is recommended\n");
593 else if (le32_to_cpu(es->s_checkinterval) &&
594 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
595 printk ("EXT2-fs warning: checktime reached, "
596 "running e2fsck is recommended\n");
597 if (!le16_to_cpu(es->s_max_mnt_count))
598 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
599 le16_add_cpu(&es->s_mnt_count, 1);
600 ext2_write_super(sb);
601 if (test_opt (sb, DEBUG))
602 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
603 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
604 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
605 sbi->s_frag_size,
606 sbi->s_groups_count,
607 EXT2_BLOCKS_PER_GROUP(sb),
608 EXT2_INODES_PER_GROUP(sb),
609 sbi->s_mount_opt);
610 return res;
611 }
612
613 static int ext2_check_descriptors(struct super_block *sb)
614 {
615 int i;
616 struct ext2_sb_info *sbi = EXT2_SB(sb);
617
618 ext2_debug ("Checking group descriptors");
619
620 for (i = 0; i < sbi->s_groups_count; i++) {
621 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
622 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
623 ext2_fsblk_t last_block;
624
625 if (i == sbi->s_groups_count - 1)
626 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
627 else
628 last_block = first_block +
629 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
630
631 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
632 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
633 {
634 ext2_error (sb, "ext2_check_descriptors",
635 "Block bitmap for group %d"
636 " not in group (block %lu)!",
637 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
638 return 0;
639 }
640 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
641 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
642 {
643 ext2_error (sb, "ext2_check_descriptors",
644 "Inode bitmap for group %d"
645 " not in group (block %lu)!",
646 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
647 return 0;
648 }
649 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
650 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
651 last_block)
652 {
653 ext2_error (sb, "ext2_check_descriptors",
654 "Inode table for group %d"
655 " not in group (block %lu)!",
656 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
657 return 0;
658 }
659 }
660 return 1;
661 }
662
663 /*
664 * Maximal file size. There is a direct, and {,double-,triple-}indirect
665 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
666 * We need to be 1 filesystem block less than the 2^32 sector limit.
667 */
668 static loff_t ext2_max_size(int bits)
669 {
670 loff_t res = EXT2_NDIR_BLOCKS;
671 int meta_blocks;
672 loff_t upper_limit;
673
674 /* This is calculated to be the largest file size for a
675 * dense, file such that the total number of
676 * sectors in the file, including data and all indirect blocks,
677 * does not exceed 2^32 -1
678 * __u32 i_blocks representing the total number of
679 * 512 bytes blocks of the file
680 */
681 upper_limit = (1LL << 32) - 1;
682
683 /* total blocks in file system block size */
684 upper_limit >>= (bits - 9);
685
686
687 /* indirect blocks */
688 meta_blocks = 1;
689 /* double indirect blocks */
690 meta_blocks += 1 + (1LL << (bits-2));
691 /* tripple indirect blocks */
692 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
693
694 upper_limit -= meta_blocks;
695 upper_limit <<= bits;
696
697 res += 1LL << (bits-2);
698 res += 1LL << (2*(bits-2));
699 res += 1LL << (3*(bits-2));
700 res <<= bits;
701 if (res > upper_limit)
702 res = upper_limit;
703
704 if (res > MAX_LFS_FILESIZE)
705 res = MAX_LFS_FILESIZE;
706
707 return res;
708 }
709
710 static unsigned long descriptor_loc(struct super_block *sb,
711 unsigned long logic_sb_block,
712 int nr)
713 {
714 struct ext2_sb_info *sbi = EXT2_SB(sb);
715 unsigned long bg, first_meta_bg;
716 int has_super = 0;
717
718 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
719
720 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
721 nr < first_meta_bg)
722 return (logic_sb_block + nr + 1);
723 bg = sbi->s_desc_per_block * nr;
724 if (ext2_bg_has_super(sb, bg))
725 has_super = 1;
726
727 return ext2_group_first_block_no(sb, bg) + has_super;
728 }
729
730 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
731 {
732 struct buffer_head * bh;
733 struct ext2_sb_info * sbi;
734 struct ext2_super_block * es;
735 struct inode *root;
736 unsigned long block;
737 unsigned long sb_block = get_sb_block(&data);
738 unsigned long logic_sb_block;
739 unsigned long offset = 0;
740 unsigned long def_mount_opts;
741 long ret = -EINVAL;
742 int blocksize = BLOCK_SIZE;
743 int db_count;
744 int i, j;
745 __le32 features;
746 int err;
747
748 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
749 if (!sbi)
750 return -ENOMEM;
751
752 sbi->s_blockgroup_lock =
753 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
754 if (!sbi->s_blockgroup_lock) {
755 kfree(sbi);
756 return -ENOMEM;
757 }
758 sb->s_fs_info = sbi;
759 sbi->s_sb_block = sb_block;
760
761 /*
762 * See what the current blocksize for the device is, and
763 * use that as the blocksize. Otherwise (or if the blocksize
764 * is smaller than the default) use the default.
765 * This is important for devices that have a hardware
766 * sectorsize that is larger than the default.
767 */
768 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
769 if (!blocksize) {
770 printk ("EXT2-fs: unable to set blocksize\n");
771 goto failed_sbi;
772 }
773
774 /*
775 * If the superblock doesn't start on a hardware sector boundary,
776 * calculate the offset.
777 */
778 if (blocksize != BLOCK_SIZE) {
779 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
780 offset = (sb_block*BLOCK_SIZE) % blocksize;
781 } else {
782 logic_sb_block = sb_block;
783 }
784
785 if (!(bh = sb_bread(sb, logic_sb_block))) {
786 printk ("EXT2-fs: unable to read superblock\n");
787 goto failed_sbi;
788 }
789 /*
790 * Note: s_es must be initialized as soon as possible because
791 * some ext2 macro-instructions depend on its value
792 */
793 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
794 sbi->s_es = es;
795 sb->s_magic = le16_to_cpu(es->s_magic);
796
797 if (sb->s_magic != EXT2_SUPER_MAGIC)
798 goto cantfind_ext2;
799
800 /* Set defaults before we parse the mount options */
801 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
802 if (def_mount_opts & EXT2_DEFM_DEBUG)
803 set_opt(sbi->s_mount_opt, DEBUG);
804 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
805 set_opt(sbi->s_mount_opt, GRPID);
806 if (def_mount_opts & EXT2_DEFM_UID16)
807 set_opt(sbi->s_mount_opt, NO_UID32);
808 #ifdef CONFIG_EXT2_FS_XATTR
809 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
810 set_opt(sbi->s_mount_opt, XATTR_USER);
811 #endif
812 #ifdef CONFIG_EXT2_FS_POSIX_ACL
813 if (def_mount_opts & EXT2_DEFM_ACL)
814 set_opt(sbi->s_mount_opt, POSIX_ACL);
815 #endif
816
817 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
818 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
819 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
820 set_opt(sbi->s_mount_opt, ERRORS_CONT);
821 else
822 set_opt(sbi->s_mount_opt, ERRORS_RO);
823
824 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
825 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
826
827 set_opt(sbi->s_mount_opt, RESERVATION);
828
829 if (!parse_options ((char *) data, sbi))
830 goto failed_mount;
831
832 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
833 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
834 MS_POSIXACL : 0);
835
836 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
837 EXT2_MOUNT_XIP if not */
838
839 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
840 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
841 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
842 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
843 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
844 "running e2fsck is recommended\n");
845 /*
846 * Check feature flags regardless of the revision level, since we
847 * previously didn't change the revision level when setting the flags,
848 * so there is a chance incompat flags are set on a rev 0 filesystem.
849 */
850 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
851 if (features) {
852 printk("EXT2-fs: %s: couldn't mount because of "
853 "unsupported optional features (%x).\n",
854 sb->s_id, le32_to_cpu(features));
855 goto failed_mount;
856 }
857 if (!(sb->s_flags & MS_RDONLY) &&
858 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
859 printk("EXT2-fs: %s: couldn't mount RDWR because of "
860 "unsupported optional features (%x).\n",
861 sb->s_id, le32_to_cpu(features));
862 goto failed_mount;
863 }
864
865 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
866
867 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
868 if (!silent)
869 printk("XIP: Unsupported blocksize\n");
870 goto failed_mount;
871 }
872
873 /* If the blocksize doesn't match, re-read the thing.. */
874 if (sb->s_blocksize != blocksize) {
875 brelse(bh);
876
877 if (!sb_set_blocksize(sb, blocksize)) {
878 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
879 goto failed_sbi;
880 }
881
882 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
883 offset = (sb_block*BLOCK_SIZE) % blocksize;
884 bh = sb_bread(sb, logic_sb_block);
885 if(!bh) {
886 printk("EXT2-fs: Couldn't read superblock on "
887 "2nd try.\n");
888 goto failed_sbi;
889 }
890 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
891 sbi->s_es = es;
892 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
893 printk ("EXT2-fs: Magic mismatch, very weird !\n");
894 goto failed_mount;
895 }
896 }
897
898 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
899
900 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
901 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
902 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
903 } else {
904 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
905 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
906 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
907 !is_power_of_2(sbi->s_inode_size) ||
908 (sbi->s_inode_size > blocksize)) {
909 printk ("EXT2-fs: unsupported inode size: %d\n",
910 sbi->s_inode_size);
911 goto failed_mount;
912 }
913 }
914
915 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
916 le32_to_cpu(es->s_log_frag_size);
917 if (sbi->s_frag_size == 0)
918 goto cantfind_ext2;
919 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
920
921 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
922 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
923 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
924
925 if (EXT2_INODE_SIZE(sb) == 0)
926 goto cantfind_ext2;
927 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
928 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
929 goto cantfind_ext2;
930 sbi->s_itb_per_group = sbi->s_inodes_per_group /
931 sbi->s_inodes_per_block;
932 sbi->s_desc_per_block = sb->s_blocksize /
933 sizeof (struct ext2_group_desc);
934 sbi->s_sbh = bh;
935 sbi->s_mount_state = le16_to_cpu(es->s_state);
936 sbi->s_addr_per_block_bits =
937 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
938 sbi->s_desc_per_block_bits =
939 ilog2 (EXT2_DESC_PER_BLOCK(sb));
940
941 if (sb->s_magic != EXT2_SUPER_MAGIC)
942 goto cantfind_ext2;
943
944 if (sb->s_blocksize != bh->b_size) {
945 if (!silent)
946 printk ("VFS: Unsupported blocksize on dev "
947 "%s.\n", sb->s_id);
948 goto failed_mount;
949 }
950
951 if (sb->s_blocksize != sbi->s_frag_size) {
952 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
953 sbi->s_frag_size, sb->s_blocksize);
954 goto failed_mount;
955 }
956
957 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
958 printk ("EXT2-fs: #blocks per group too big: %lu\n",
959 sbi->s_blocks_per_group);
960 goto failed_mount;
961 }
962 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
963 printk ("EXT2-fs: #fragments per group too big: %lu\n",
964 sbi->s_frags_per_group);
965 goto failed_mount;
966 }
967 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
968 printk ("EXT2-fs: #inodes per group too big: %lu\n",
969 sbi->s_inodes_per_group);
970 goto failed_mount;
971 }
972
973 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
974 goto cantfind_ext2;
975 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
976 le32_to_cpu(es->s_first_data_block) - 1)
977 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
978 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
979 EXT2_DESC_PER_BLOCK(sb);
980 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
981 if (sbi->s_group_desc == NULL) {
982 printk ("EXT2-fs: not enough memory\n");
983 goto failed_mount;
984 }
985 bgl_lock_init(sbi->s_blockgroup_lock);
986 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
987 if (!sbi->s_debts) {
988 printk ("EXT2-fs: not enough memory\n");
989 goto failed_mount_group_desc;
990 }
991 for (i = 0; i < db_count; i++) {
992 block = descriptor_loc(sb, logic_sb_block, i);
993 sbi->s_group_desc[i] = sb_bread(sb, block);
994 if (!sbi->s_group_desc[i]) {
995 for (j = 0; j < i; j++)
996 brelse (sbi->s_group_desc[j]);
997 printk ("EXT2-fs: unable to read group descriptors\n");
998 goto failed_mount_group_desc;
999 }
1000 }
1001 if (!ext2_check_descriptors (sb)) {
1002 printk ("EXT2-fs: group descriptors corrupted!\n");
1003 goto failed_mount2;
1004 }
1005 sbi->s_gdb_count = db_count;
1006 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1007 spin_lock_init(&sbi->s_next_gen_lock);
1008
1009 /* per fileystem reservation list head & lock */
1010 spin_lock_init(&sbi->s_rsv_window_lock);
1011 sbi->s_rsv_window_root = RB_ROOT;
1012 /*
1013 * Add a single, static dummy reservation to the start of the
1014 * reservation window list --- it gives us a placeholder for
1015 * append-at-start-of-list which makes the allocation logic
1016 * _much_ simpler.
1017 */
1018 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1019 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1020 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1021 sbi->s_rsv_window_head.rsv_goal_size = 0;
1022 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1023
1024 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1025 ext2_count_free_blocks(sb));
1026 if (!err) {
1027 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1028 ext2_count_free_inodes(sb));
1029 }
1030 if (!err) {
1031 err = percpu_counter_init(&sbi->s_dirs_counter,
1032 ext2_count_dirs(sb));
1033 }
1034 if (err) {
1035 printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1036 goto failed_mount3;
1037 }
1038 /*
1039 * set up enough so that it can read an inode
1040 */
1041 sb->s_op = &ext2_sops;
1042 sb->s_export_op = &ext2_export_ops;
1043 sb->s_xattr = ext2_xattr_handlers;
1044 root = ext2_iget(sb, EXT2_ROOT_INO);
1045 if (IS_ERR(root)) {
1046 ret = PTR_ERR(root);
1047 goto failed_mount3;
1048 }
1049 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1050 iput(root);
1051 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1052 goto failed_mount3;
1053 }
1054
1055 sb->s_root = d_alloc_root(root);
1056 if (!sb->s_root) {
1057 iput(root);
1058 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1059 ret = -ENOMEM;
1060 goto failed_mount3;
1061 }
1062 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1063 ext2_warning(sb, __func__,
1064 "mounting ext3 filesystem as ext2");
1065 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1066 return 0;
1067
1068 cantfind_ext2:
1069 if (!silent)
1070 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1071 sb->s_id);
1072 goto failed_mount;
1073 failed_mount3:
1074 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1075 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1076 percpu_counter_destroy(&sbi->s_dirs_counter);
1077 failed_mount2:
1078 for (i = 0; i < db_count; i++)
1079 brelse(sbi->s_group_desc[i]);
1080 failed_mount_group_desc:
1081 kfree(sbi->s_group_desc);
1082 kfree(sbi->s_debts);
1083 failed_mount:
1084 brelse(bh);
1085 failed_sbi:
1086 sb->s_fs_info = NULL;
1087 kfree(sbi->s_blockgroup_lock);
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 static int ext2_sync_fs(struct super_block *sb, int wait)
1122 {
1123 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1124
1125 lock_kernel();
1126 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1127 ext2_debug("setting valid to 0\n");
1128 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1129 es->s_free_blocks_count =
1130 cpu_to_le32(ext2_count_free_blocks(sb));
1131 es->s_free_inodes_count =
1132 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 return 0;
1142 }
1143
1144
1145 void ext2_write_super(struct super_block *sb)
1146 {
1147 if (!(sb->s_flags & MS_RDONLY))
1148 ext2_sync_fs(sb, 1);
1149 else
1150 sb->s_dirt = 0;
1151 }
1152
1153 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1154 {
1155 struct ext2_sb_info * sbi = EXT2_SB(sb);
1156 struct ext2_super_block * es;
1157 unsigned long old_mount_opt = sbi->s_mount_opt;
1158 struct ext2_mount_options old_opts;
1159 unsigned long old_sb_flags;
1160 int err;
1161
1162 lock_kernel();
1163
1164 /* Store the old options */
1165 old_sb_flags = sb->s_flags;
1166 old_opts.s_mount_opt = sbi->s_mount_opt;
1167 old_opts.s_resuid = sbi->s_resuid;
1168 old_opts.s_resgid = sbi->s_resgid;
1169
1170 /*
1171 * Allow the "check" option to be passed as a remount option.
1172 */
1173 if (!parse_options (data, sbi)) {
1174 err = -EINVAL;
1175 goto restore_opts;
1176 }
1177
1178 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1179 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1180
1181 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1182 EXT2_MOUNT_XIP if not */
1183
1184 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1185 printk("XIP: Unsupported blocksize\n");
1186 err = -EINVAL;
1187 goto restore_opts;
1188 }
1189
1190 es = sbi->s_es;
1191 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1192 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1193 invalidate_inodes(sb)) {
1194 ext2_warning(sb, __func__, "refusing change of xip flag "
1195 "with busy inodes while remounting");
1196 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1197 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1198 }
1199 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1200 unlock_kernel();
1201 return 0;
1202 }
1203 if (*flags & MS_RDONLY) {
1204 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1205 !(sbi->s_mount_state & EXT2_VALID_FS)) {
1206 unlock_kernel();
1207 return 0;
1208 }
1209 /*
1210 * OK, we are remounting a valid rw partition rdonly, so set
1211 * the rdonly flag and then mark the partition as valid again.
1212 */
1213 es->s_state = cpu_to_le16(sbi->s_mount_state);
1214 es->s_mtime = cpu_to_le32(get_seconds());
1215 } else {
1216 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1217 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1218 if (ret) {
1219 printk("EXT2-fs: %s: couldn't remount RDWR because of "
1220 "unsupported optional features (%x).\n",
1221 sb->s_id, le32_to_cpu(ret));
1222 err = -EROFS;
1223 goto restore_opts;
1224 }
1225 /*
1226 * Mounting a RDONLY partition read-write, so reread and
1227 * store the current valid flag. (It may have been changed
1228 * by e2fsck since we originally mounted the partition.)
1229 */
1230 sbi->s_mount_state = le16_to_cpu(es->s_state);
1231 if (!ext2_setup_super (sb, es, 0))
1232 sb->s_flags &= ~MS_RDONLY;
1233 }
1234 ext2_sync_super(sb, es);
1235 unlock_kernel();
1236 return 0;
1237 restore_opts:
1238 sbi->s_mount_opt = old_opts.s_mount_opt;
1239 sbi->s_resuid = old_opts.s_resuid;
1240 sbi->s_resgid = old_opts.s_resgid;
1241 sb->s_flags = old_sb_flags;
1242 unlock_kernel();
1243 return err;
1244 }
1245
1246 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1247 {
1248 struct super_block *sb = dentry->d_sb;
1249 struct ext2_sb_info *sbi = EXT2_SB(sb);
1250 struct ext2_super_block *es = sbi->s_es;
1251 u64 fsid;
1252
1253 if (test_opt (sb, MINIX_DF))
1254 sbi->s_overhead_last = 0;
1255 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1256 unsigned long i, overhead = 0;
1257 smp_rmb();
1258
1259 /*
1260 * Compute the overhead (FS structures). This is constant
1261 * for a given filesystem unless the number of block groups
1262 * changes so we cache the previous value until it does.
1263 */
1264
1265 /*
1266 * All of the blocks before first_data_block are
1267 * overhead
1268 */
1269 overhead = le32_to_cpu(es->s_first_data_block);
1270
1271 /*
1272 * Add the overhead attributed to the superblock and
1273 * block group descriptors. If the sparse superblocks
1274 * feature is turned on, then not all groups have this.
1275 */
1276 for (i = 0; i < sbi->s_groups_count; i++)
1277 overhead += ext2_bg_has_super(sb, i) +
1278 ext2_bg_num_gdb(sb, i);
1279
1280 /*
1281 * Every block group has an inode bitmap, a block
1282 * bitmap, and an inode table.
1283 */
1284 overhead += (sbi->s_groups_count *
1285 (2 + sbi->s_itb_per_group));
1286 sbi->s_overhead_last = overhead;
1287 smp_wmb();
1288 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1289 }
1290
1291 buf->f_type = EXT2_SUPER_MAGIC;
1292 buf->f_bsize = sb->s_blocksize;
1293 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1294 buf->f_bfree = ext2_count_free_blocks(sb);
1295 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1296 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1297 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1298 buf->f_bavail = 0;
1299 buf->f_files = le32_to_cpu(es->s_inodes_count);
1300 buf->f_ffree = ext2_count_free_inodes(sb);
1301 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1302 buf->f_namelen = EXT2_NAME_LEN;
1303 fsid = le64_to_cpup((void *)es->s_uuid) ^
1304 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1305 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1306 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1307 return 0;
1308 }
1309
1310 static int ext2_get_sb(struct file_system_type *fs_type,
1311 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1312 {
1313 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1314 }
1315
1316 #ifdef CONFIG_QUOTA
1317
1318 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1319 * acquiring the locks... As quota files are never truncated and quota code
1320 * itself serializes the operations (and noone else should touch the files)
1321 * we don't have to be afraid of races */
1322 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1323 size_t len, loff_t off)
1324 {
1325 struct inode *inode = sb_dqopt(sb)->files[type];
1326 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1327 int err = 0;
1328 int offset = off & (sb->s_blocksize - 1);
1329 int tocopy;
1330 size_t toread;
1331 struct buffer_head tmp_bh;
1332 struct buffer_head *bh;
1333 loff_t i_size = i_size_read(inode);
1334
1335 if (off > i_size)
1336 return 0;
1337 if (off+len > i_size)
1338 len = i_size-off;
1339 toread = len;
1340 while (toread > 0) {
1341 tocopy = sb->s_blocksize - offset < toread ?
1342 sb->s_blocksize - offset : toread;
1343
1344 tmp_bh.b_state = 0;
1345 tmp_bh.b_size = sb->s_blocksize;
1346 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1347 if (err < 0)
1348 return err;
1349 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1350 memset(data, 0, tocopy);
1351 else {
1352 bh = sb_bread(sb, tmp_bh.b_blocknr);
1353 if (!bh)
1354 return -EIO;
1355 memcpy(data, bh->b_data+offset, tocopy);
1356 brelse(bh);
1357 }
1358 offset = 0;
1359 toread -= tocopy;
1360 data += tocopy;
1361 blk++;
1362 }
1363 return len;
1364 }
1365
1366 /* Write to quotafile */
1367 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1368 const char *data, size_t len, loff_t off)
1369 {
1370 struct inode *inode = sb_dqopt(sb)->files[type];
1371 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1372 int err = 0;
1373 int offset = off & (sb->s_blocksize - 1);
1374 int tocopy;
1375 size_t towrite = len;
1376 struct buffer_head tmp_bh;
1377 struct buffer_head *bh;
1378
1379 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1380 while (towrite > 0) {
1381 tocopy = sb->s_blocksize - offset < towrite ?
1382 sb->s_blocksize - offset : towrite;
1383
1384 tmp_bh.b_state = 0;
1385 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1386 if (err < 0)
1387 goto out;
1388 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1389 bh = sb_bread(sb, tmp_bh.b_blocknr);
1390 else
1391 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1392 if (!bh) {
1393 err = -EIO;
1394 goto out;
1395 }
1396 lock_buffer(bh);
1397 memcpy(bh->b_data+offset, data, tocopy);
1398 flush_dcache_page(bh->b_page);
1399 set_buffer_uptodate(bh);
1400 mark_buffer_dirty(bh);
1401 unlock_buffer(bh);
1402 brelse(bh);
1403 offset = 0;
1404 towrite -= tocopy;
1405 data += tocopy;
1406 blk++;
1407 }
1408 out:
1409 if (len == towrite) {
1410 mutex_unlock(&inode->i_mutex);
1411 return err;
1412 }
1413 if (inode->i_size < off+len-towrite)
1414 i_size_write(inode, off+len-towrite);
1415 inode->i_version++;
1416 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1417 mark_inode_dirty(inode);
1418 mutex_unlock(&inode->i_mutex);
1419 return len - towrite;
1420 }
1421
1422 #endif
1423
1424 static struct file_system_type ext2_fs_type = {
1425 .owner = THIS_MODULE,
1426 .name = "ext2",
1427 .get_sb = ext2_get_sb,
1428 .kill_sb = kill_block_super,
1429 .fs_flags = FS_REQUIRES_DEV,
1430 };
1431
1432 static int __init init_ext2_fs(void)
1433 {
1434 int err = init_ext2_xattr();
1435 if (err)
1436 return err;
1437 err = init_inodecache();
1438 if (err)
1439 goto out1;
1440 err = register_filesystem(&ext2_fs_type);
1441 if (err)
1442 goto out;
1443 return 0;
1444 out:
1445 destroy_inodecache();
1446 out1:
1447 exit_ext2_xattr();
1448 return err;
1449 }
1450
1451 static void __exit exit_ext2_fs(void)
1452 {
1453 unregister_filesystem(&ext2_fs_type);
1454 destroy_inodecache();
1455 exit_ext2_xattr();
1456 }
1457
1458 module_init(init_ext2_fs)
1459 module_exit(exit_ext2_fs)
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