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Merge branch 'kvm-updates/2.6.33' of git://git.kernel.org/pub/scm/virt/kvm/kvm
[linux-2.6/linux-2.6-openrd.git] / fs / ext2 / super.c
blobf9cb54a585ce8298e7b2fb9bf90169f8323de289
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 (%s): error: %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 ext2_msg(sb, KERN_CRIT,
70 "error: remounting filesystem read-only");
71 sb->s_flags |= MS_RDONLY;
72 }
73 }
74
75 void ext2_msg(struct super_block *sb, const char *prefix,
76 const char *fmt, ...)
77 {
78 va_list args;
79
80 va_start(args, fmt);
81 printk("%sEXT2-fs (%s): ", prefix, sb->s_id);
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_msg(sb, KERN_WARNING,
95 "warning: updating to rev %d because of "
96 "new feature flag, 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, struct super_block *sb)
423 {
424 char *p;
425 struct ext2_sb_info *sbi = EXT2_SB(sb);
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 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
509 "not supported");
510 break;
511 #endif
512 #ifdef CONFIG_EXT2_FS_POSIX_ACL
513 case Opt_acl:
514 set_opt(sbi->s_mount_opt, POSIX_ACL);
515 break;
516 case Opt_noacl:
517 clear_opt(sbi->s_mount_opt, POSIX_ACL);
518 break;
519 #else
520 case Opt_acl:
521 case Opt_noacl:
522 ext2_msg(sb, KERN_INFO,
523 "(no)acl options not supported");
524 break;
525 #endif
526 case Opt_xip:
527 #ifdef CONFIG_EXT2_FS_XIP
528 set_opt (sbi->s_mount_opt, XIP);
529 #else
530 ext2_msg(sb, KERN_INFO, "xip option not supported");
531 #endif
532 break;
533
534 #if defined(CONFIG_QUOTA)
535 case Opt_quota:
536 case Opt_usrquota:
537 set_opt(sbi->s_mount_opt, USRQUOTA);
538 break;
539
540 case Opt_grpquota:
541 set_opt(sbi->s_mount_opt, GRPQUOTA);
542 break;
543 #else
544 case Opt_quota:
545 case Opt_usrquota:
546 case Opt_grpquota:
547 ext2_msg(sb, KERN_INFO,
548 "quota operations not supported");
549 break;
550 #endif
551
552 case Opt_reservation:
553 set_opt(sbi->s_mount_opt, RESERVATION);
554 ext2_msg(sb, KERN_INFO, "reservations ON");
555 break;
556 case Opt_noreservation:
557 clear_opt(sbi->s_mount_opt, RESERVATION);
558 ext2_msg(sb, KERN_INFO, "reservations OFF");
559 break;
560 case Opt_ignore:
561 break;
562 default:
563 return 0;
564 }
565 }
566 return 1;
567 }
568
569 static int ext2_setup_super (struct super_block * sb,
570 struct ext2_super_block * es,
571 int read_only)
572 {
573 int res = 0;
574 struct ext2_sb_info *sbi = EXT2_SB(sb);
575
576 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
577 ext2_msg(sb, KERN_ERR,
578 "error: revision level too high, "
579 "forcing read-only mode");
580 res = MS_RDONLY;
581 }
582 if (read_only)
583 return res;
584 if (!(sbi->s_mount_state & EXT2_VALID_FS))
585 ext2_msg(sb, KERN_WARNING,
586 "warning: mounting unchecked fs, "
587 "running e2fsck is recommended");
588 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
589 ext2_msg(sb, KERN_WARNING,
590 "warning: mounting fs with errors, "
591 "running e2fsck is recommended");
592 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
593 le16_to_cpu(es->s_mnt_count) >=
594 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
595 ext2_msg(sb, KERN_WARNING,
596 "warning: maximal mount count reached, "
597 "running e2fsck is recommended");
598 else if (le32_to_cpu(es->s_checkinterval) &&
599 (le32_to_cpu(es->s_lastcheck) +
600 le32_to_cpu(es->s_checkinterval) <= get_seconds()))
601 ext2_msg(sb, KERN_WARNING,
602 "warning: checktime reached, "
603 "running e2fsck is recommended");
604 if (!le16_to_cpu(es->s_max_mnt_count))
605 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
606 le16_add_cpu(&es->s_mnt_count, 1);
607 ext2_write_super(sb);
608 if (test_opt (sb, DEBUG))
609 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
610 "bpg=%lu, ipg=%lu, mo=%04lx]",
611 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
612 sbi->s_frag_size,
613 sbi->s_groups_count,
614 EXT2_BLOCKS_PER_GROUP(sb),
615 EXT2_INODES_PER_GROUP(sb),
616 sbi->s_mount_opt);
617 return res;
618 }
619
620 static int ext2_check_descriptors(struct super_block *sb)
621 {
622 int i;
623 struct ext2_sb_info *sbi = EXT2_SB(sb);
624
625 ext2_debug ("Checking group descriptors");
626
627 for (i = 0; i < sbi->s_groups_count; i++) {
628 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
629 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
630 ext2_fsblk_t last_block;
631
632 if (i == sbi->s_groups_count - 1)
633 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
634 else
635 last_block = first_block +
636 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
637
638 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
639 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
640 {
641 ext2_error (sb, "ext2_check_descriptors",
642 "Block bitmap for group %d"
643 " not in group (block %lu)!",
644 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
645 return 0;
646 }
647 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
648 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
649 {
650 ext2_error (sb, "ext2_check_descriptors",
651 "Inode bitmap for group %d"
652 " not in group (block %lu)!",
653 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
654 return 0;
655 }
656 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
657 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
658 last_block)
659 {
660 ext2_error (sb, "ext2_check_descriptors",
661 "Inode table for group %d"
662 " not in group (block %lu)!",
663 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
664 return 0;
665 }
666 }
667 return 1;
668 }
669
670 /*
671 * Maximal file size. There is a direct, and {,double-,triple-}indirect
672 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
673 * We need to be 1 filesystem block less than the 2^32 sector limit.
674 */
675 static loff_t ext2_max_size(int bits)
676 {
677 loff_t res = EXT2_NDIR_BLOCKS;
678 int meta_blocks;
679 loff_t upper_limit;
680
681 /* This is calculated to be the largest file size for a
682 * dense, file such that the total number of
683 * sectors in the file, including data and all indirect blocks,
684 * does not exceed 2^32 -1
685 * __u32 i_blocks representing the total number of
686 * 512 bytes blocks of the file
687 */
688 upper_limit = (1LL << 32) - 1;
689
690 /* total blocks in file system block size */
691 upper_limit >>= (bits - 9);
692
693
694 /* indirect blocks */
695 meta_blocks = 1;
696 /* double indirect blocks */
697 meta_blocks += 1 + (1LL << (bits-2));
698 /* tripple indirect blocks */
699 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
700
701 upper_limit -= meta_blocks;
702 upper_limit <<= bits;
703
704 res += 1LL << (bits-2);
705 res += 1LL << (2*(bits-2));
706 res += 1LL << (3*(bits-2));
707 res <<= bits;
708 if (res > upper_limit)
709 res = upper_limit;
710
711 if (res > MAX_LFS_FILESIZE)
712 res = MAX_LFS_FILESIZE;
713
714 return res;
715 }
716
717 static unsigned long descriptor_loc(struct super_block *sb,
718 unsigned long logic_sb_block,
719 int nr)
720 {
721 struct ext2_sb_info *sbi = EXT2_SB(sb);
722 unsigned long bg, first_meta_bg;
723 int has_super = 0;
724
725 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
726
727 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
728 nr < first_meta_bg)
729 return (logic_sb_block + nr + 1);
730 bg = sbi->s_desc_per_block * nr;
731 if (ext2_bg_has_super(sb, bg))
732 has_super = 1;
733
734 return ext2_group_first_block_no(sb, bg) + has_super;
735 }
736
737 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
738 {
739 struct buffer_head * bh;
740 struct ext2_sb_info * sbi;
741 struct ext2_super_block * es;
742 struct inode *root;
743 unsigned long block;
744 unsigned long sb_block = get_sb_block(&data);
745 unsigned long logic_sb_block;
746 unsigned long offset = 0;
747 unsigned long def_mount_opts;
748 long ret = -EINVAL;
749 int blocksize = BLOCK_SIZE;
750 int db_count;
751 int i, j;
752 __le32 features;
753 int err;
754
755 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
756 if (!sbi)
757 return -ENOMEM;
758
759 sbi->s_blockgroup_lock =
760 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
761 if (!sbi->s_blockgroup_lock) {
762 kfree(sbi);
763 return -ENOMEM;
764 }
765 sb->s_fs_info = sbi;
766 sbi->s_sb_block = sb_block;
767
768 /*
769 * See what the current blocksize for the device is, and
770 * use that as the blocksize. Otherwise (or if the blocksize
771 * is smaller than the default) use the default.
772 * This is important for devices that have a hardware
773 * sectorsize that is larger than the default.
774 */
775 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
776 if (!blocksize) {
777 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
778 goto failed_sbi;
779 }
780
781 /*
782 * If the superblock doesn't start on a hardware sector boundary,
783 * calculate the offset.
784 */
785 if (blocksize != BLOCK_SIZE) {
786 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
787 offset = (sb_block*BLOCK_SIZE) % blocksize;
788 } else {
789 logic_sb_block = sb_block;
790 }
791
792 if (!(bh = sb_bread(sb, logic_sb_block))) {
793 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
794 goto failed_sbi;
795 }
796 /*
797 * Note: s_es must be initialized as soon as possible because
798 * some ext2 macro-instructions depend on its value
799 */
800 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
801 sbi->s_es = es;
802 sb->s_magic = le16_to_cpu(es->s_magic);
803
804 if (sb->s_magic != EXT2_SUPER_MAGIC)
805 goto cantfind_ext2;
806
807 /* Set defaults before we parse the mount options */
808 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
809 if (def_mount_opts & EXT2_DEFM_DEBUG)
810 set_opt(sbi->s_mount_opt, DEBUG);
811 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
812 set_opt(sbi->s_mount_opt, GRPID);
813 if (def_mount_opts & EXT2_DEFM_UID16)
814 set_opt(sbi->s_mount_opt, NO_UID32);
815 #ifdef CONFIG_EXT2_FS_XATTR
816 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
817 set_opt(sbi->s_mount_opt, XATTR_USER);
818 #endif
819 #ifdef CONFIG_EXT2_FS_POSIX_ACL
820 if (def_mount_opts & EXT2_DEFM_ACL)
821 set_opt(sbi->s_mount_opt, POSIX_ACL);
822 #endif
823
824 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
825 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
826 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
827 set_opt(sbi->s_mount_opt, ERRORS_CONT);
828 else
829 set_opt(sbi->s_mount_opt, ERRORS_RO);
830
831 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
832 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
833
834 set_opt(sbi->s_mount_opt, RESERVATION);
835
836 if (!parse_options((char *) data, sb))
837 goto failed_mount;
838
839 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
840 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
841 MS_POSIXACL : 0);
842
843 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
844 EXT2_MOUNT_XIP if not */
845
846 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
847 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
848 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
849 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
850 ext2_msg(sb, KERN_WARNING,
851 "warning: feature flags set on rev 0 fs, "
852 "running e2fsck is recommended");
853 /*
854 * Check feature flags regardless of the revision level, since we
855 * previously didn't change the revision level when setting the flags,
856 * so there is a chance incompat flags are set on a rev 0 filesystem.
857 */
858 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
859 if (features) {
860 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
861 "unsupported optional features (%x)",
862 le32_to_cpu(features));
863 goto failed_mount;
864 }
865 if (!(sb->s_flags & MS_RDONLY) &&
866 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
867 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
868 "unsupported optional features (%x)",
869 le32_to_cpu(features));
870 goto failed_mount;
871 }
872
873 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
874
875 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
876 if (!silent)
877 ext2_msg(sb, KERN_ERR,
878 "error: unsupported blocksize for xip");
879 goto failed_mount;
880 }
881
882 /* If the blocksize doesn't match, re-read the thing.. */
883 if (sb->s_blocksize != blocksize) {
884 brelse(bh);
885
886 if (!sb_set_blocksize(sb, blocksize)) {
887 ext2_msg(sb, KERN_ERR, "error: blocksize is too small");
888 goto failed_sbi;
889 }
890
891 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
892 offset = (sb_block*BLOCK_SIZE) % blocksize;
893 bh = sb_bread(sb, logic_sb_block);
894 if(!bh) {
895 ext2_msg(sb, KERN_ERR, "error: couldn't read"
896 "superblock on 2nd try");
897 goto failed_sbi;
898 }
899 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
900 sbi->s_es = es;
901 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
902 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
903 goto failed_mount;
904 }
905 }
906
907 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
908
909 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
910 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
911 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
912 } else {
913 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
914 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
915 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
916 !is_power_of_2(sbi->s_inode_size) ||
917 (sbi->s_inode_size > blocksize)) {
918 ext2_msg(sb, KERN_ERR,
919 "error: unsupported inode size: %d",
920 sbi->s_inode_size);
921 goto failed_mount;
922 }
923 }
924
925 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
926 le32_to_cpu(es->s_log_frag_size);
927 if (sbi->s_frag_size == 0)
928 goto cantfind_ext2;
929 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
930
931 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
932 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
933 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
934
935 if (EXT2_INODE_SIZE(sb) == 0)
936 goto cantfind_ext2;
937 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
938 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
939 goto cantfind_ext2;
940 sbi->s_itb_per_group = sbi->s_inodes_per_group /
941 sbi->s_inodes_per_block;
942 sbi->s_desc_per_block = sb->s_blocksize /
943 sizeof (struct ext2_group_desc);
944 sbi->s_sbh = bh;
945 sbi->s_mount_state = le16_to_cpu(es->s_state);
946 sbi->s_addr_per_block_bits =
947 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
948 sbi->s_desc_per_block_bits =
949 ilog2 (EXT2_DESC_PER_BLOCK(sb));
950
951 if (sb->s_magic != EXT2_SUPER_MAGIC)
952 goto cantfind_ext2;
953
954 if (sb->s_blocksize != bh->b_size) {
955 if (!silent)
956 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
957 goto failed_mount;
958 }
959
960 if (sb->s_blocksize != sbi->s_frag_size) {
961 ext2_msg(sb, KERN_ERR,
962 "error: fragsize %lu != blocksize %lu"
963 "(not supported yet)",
964 sbi->s_frag_size, sb->s_blocksize);
965 goto failed_mount;
966 }
967
968 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
969 ext2_msg(sb, KERN_ERR,
970 "error: #blocks per group too big: %lu",
971 sbi->s_blocks_per_group);
972 goto failed_mount;
973 }
974 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
975 ext2_msg(sb, KERN_ERR,
976 "error: #fragments per group too big: %lu",
977 sbi->s_frags_per_group);
978 goto failed_mount;
979 }
980 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
981 ext2_msg(sb, KERN_ERR,
982 "error: #inodes per group too big: %lu",
983 sbi->s_inodes_per_group);
984 goto failed_mount;
985 }
986
987 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
988 goto cantfind_ext2;
989 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
990 le32_to_cpu(es->s_first_data_block) - 1)
991 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
992 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
993 EXT2_DESC_PER_BLOCK(sb);
994 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
995 if (sbi->s_group_desc == NULL) {
996 ext2_msg(sb, KERN_ERR, "error: not enough memory");
997 goto failed_mount;
998 }
999 bgl_lock_init(sbi->s_blockgroup_lock);
1000 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1001 if (!sbi->s_debts) {
1002 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1003 goto failed_mount_group_desc;
1004 }
1005 for (i = 0; i < db_count; i++) {
1006 block = descriptor_loc(sb, logic_sb_block, i);
1007 sbi->s_group_desc[i] = sb_bread(sb, block);
1008 if (!sbi->s_group_desc[i]) {
1009 for (j = 0; j < i; j++)
1010 brelse (sbi->s_group_desc[j]);
1011 ext2_msg(sb, KERN_ERR,
1012 "error: unable to read group descriptors");
1013 goto failed_mount_group_desc;
1014 }
1015 }
1016 if (!ext2_check_descriptors (sb)) {
1017 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1018 goto failed_mount2;
1019 }
1020 sbi->s_gdb_count = db_count;
1021 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1022 spin_lock_init(&sbi->s_next_gen_lock);
1023
1024 /* per fileystem reservation list head & lock */
1025 spin_lock_init(&sbi->s_rsv_window_lock);
1026 sbi->s_rsv_window_root = RB_ROOT;
1027 /*
1028 * Add a single, static dummy reservation to the start of the
1029 * reservation window list --- it gives us a placeholder for
1030 * append-at-start-of-list which makes the allocation logic
1031 * _much_ simpler.
1032 */
1033 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1034 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1035 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1036 sbi->s_rsv_window_head.rsv_goal_size = 0;
1037 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1038
1039 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1040 ext2_count_free_blocks(sb));
1041 if (!err) {
1042 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1043 ext2_count_free_inodes(sb));
1044 }
1045 if (!err) {
1046 err = percpu_counter_init(&sbi->s_dirs_counter,
1047 ext2_count_dirs(sb));
1048 }
1049 if (err) {
1050 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1051 goto failed_mount3;
1052 }
1053 /*
1054 * set up enough so that it can read an inode
1055 */
1056 sb->s_op = &ext2_sops;
1057 sb->s_export_op = &ext2_export_ops;
1058 sb->s_xattr = ext2_xattr_handlers;
1059 root = ext2_iget(sb, EXT2_ROOT_INO);
1060 if (IS_ERR(root)) {
1061 ret = PTR_ERR(root);
1062 goto failed_mount3;
1063 }
1064 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1065 iput(root);
1066 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1067 goto failed_mount3;
1068 }
1069
1070 sb->s_root = d_alloc_root(root);
1071 if (!sb->s_root) {
1072 iput(root);
1073 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1074 ret = -ENOMEM;
1075 goto failed_mount3;
1076 }
1077 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1078 ext2_msg(sb, KERN_WARNING,
1079 "warning: mounting ext3 filesystem as ext2");
1080 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1081 return 0;
1082
1083 cantfind_ext2:
1084 if (!silent)
1085 ext2_msg(sb, KERN_ERR,
1086 "error: can't find an ext2 filesystem on dev %s.",
1087 sb->s_id);
1088 goto failed_mount;
1089 failed_mount3:
1090 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1091 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1092 percpu_counter_destroy(&sbi->s_dirs_counter);
1093 failed_mount2:
1094 for (i = 0; i < db_count; i++)
1095 brelse(sbi->s_group_desc[i]);
1096 failed_mount_group_desc:
1097 kfree(sbi->s_group_desc);
1098 kfree(sbi->s_debts);
1099 failed_mount:
1100 brelse(bh);
1101 failed_sbi:
1102 sb->s_fs_info = NULL;
1103 kfree(sbi->s_blockgroup_lock);
1104 kfree(sbi);
1105 return ret;
1106 }
1107
1108 static void ext2_clear_super_error(struct super_block *sb)
1109 {
1110 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1111
1112 if (buffer_write_io_error(sbh)) {
1113 /*
1114 * Oh, dear. A previous attempt to write the
1115 * superblock failed. This could happen because the
1116 * USB device was yanked out. Or it could happen to
1117 * be a transient write error and maybe the block will
1118 * be remapped. Nothing we can do but to retry the
1119 * write and hope for the best.
1120 */
1121 printk(KERN_ERR "EXT2-fs: %s previous I/O error to "
1122 "superblock detected", sb->s_id);
1123 clear_buffer_write_io_error(sbh);
1124 set_buffer_uptodate(sbh);
1125 }
1126 }
1127
1128 static void ext2_commit_super (struct super_block * sb,
1129 struct ext2_super_block * es)
1130 {
1131 ext2_clear_super_error(sb);
1132 es->s_wtime = cpu_to_le32(get_seconds());
1133 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1134 sb->s_dirt = 0;
1135 }
1136
1137 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1138 {
1139 ext2_clear_super_error(sb);
1140 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1141 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1142 es->s_wtime = cpu_to_le32(get_seconds());
1143 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1144 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1145 sb->s_dirt = 0;
1146 }
1147
1148 /*
1149 * In the second extended file system, it is not necessary to
1150 * write the super block since we use a mapping of the
1151 * disk super block in a buffer.
1152 *
1153 * However, this function is still used to set the fs valid
1154 * flags to 0. We need to set this flag to 0 since the fs
1155 * may have been checked while mounted and e2fsck may have
1156 * set s_state to EXT2_VALID_FS after some corrections.
1157 */
1158
1159 static int ext2_sync_fs(struct super_block *sb, int wait)
1160 {
1161 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1162 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1163
1164 lock_kernel();
1165 if (buffer_write_io_error(sbh)) {
1166 /*
1167 * Oh, dear. A previous attempt to write the
1168 * superblock failed. This could happen because the
1169 * USB device was yanked out. Or it could happen to
1170 * be a transient write error and maybe the block will
1171 * be remapped. Nothing we can do but to retry the
1172 * write and hope for the best.
1173 */
1174 ext2_msg(sb, KERN_ERR,
1175 "previous I/O error to superblock detected\n");
1176 clear_buffer_write_io_error(sbh);
1177 set_buffer_uptodate(sbh);
1178 }
1179
1180 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1181 ext2_debug("setting valid to 0\n");
1182 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1183 es->s_free_blocks_count =
1184 cpu_to_le32(ext2_count_free_blocks(sb));
1185 es->s_free_inodes_count =
1186 cpu_to_le32(ext2_count_free_inodes(sb));
1187 es->s_mtime = cpu_to_le32(get_seconds());
1188 ext2_sync_super(sb, es);
1189 } else {
1190 ext2_commit_super(sb, es);
1191 }
1192 sb->s_dirt = 0;
1193 unlock_kernel();
1194
1195 return 0;
1196 }
1197
1198
1199 void ext2_write_super(struct super_block *sb)
1200 {
1201 if (!(sb->s_flags & MS_RDONLY))
1202 ext2_sync_fs(sb, 1);
1203 else
1204 sb->s_dirt = 0;
1205 }
1206
1207 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1208 {
1209 struct ext2_sb_info * sbi = EXT2_SB(sb);
1210 struct ext2_super_block * es;
1211 unsigned long old_mount_opt = sbi->s_mount_opt;
1212 struct ext2_mount_options old_opts;
1213 unsigned long old_sb_flags;
1214 int err;
1215
1216 lock_kernel();
1217
1218 /* Store the old options */
1219 old_sb_flags = sb->s_flags;
1220 old_opts.s_mount_opt = sbi->s_mount_opt;
1221 old_opts.s_resuid = sbi->s_resuid;
1222 old_opts.s_resgid = sbi->s_resgid;
1223
1224 /*
1225 * Allow the "check" option to be passed as a remount option.
1226 */
1227 if (!parse_options(data, sb)) {
1228 err = -EINVAL;
1229 goto restore_opts;
1230 }
1231
1232 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1233 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1234
1235 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1236 EXT2_MOUNT_XIP if not */
1237
1238 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1239 ext2_msg(sb, KERN_WARNING,
1240 "warning: unsupported blocksize for xip");
1241 err = -EINVAL;
1242 goto restore_opts;
1243 }
1244
1245 es = sbi->s_es;
1246 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1247 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1248 invalidate_inodes(sb)) {
1249 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1250 "xip flag with busy inodes while remounting");
1251 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1252 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1253 }
1254 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1255 unlock_kernel();
1256 return 0;
1257 }
1258 if (*flags & MS_RDONLY) {
1259 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1260 !(sbi->s_mount_state & EXT2_VALID_FS)) {
1261 unlock_kernel();
1262 return 0;
1263 }
1264 /*
1265 * OK, we are remounting a valid rw partition rdonly, so set
1266 * the rdonly flag and then mark the partition as valid again.
1267 */
1268 es->s_state = cpu_to_le16(sbi->s_mount_state);
1269 es->s_mtime = cpu_to_le32(get_seconds());
1270 } else {
1271 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1272 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1273 if (ret) {
1274 ext2_msg(sb, KERN_WARNING,
1275 "warning: couldn't remount RDWR because of "
1276 "unsupported optional features (%x).",
1277 le32_to_cpu(ret));
1278 err = -EROFS;
1279 goto restore_opts;
1280 }
1281 /*
1282 * Mounting a RDONLY partition read-write, so reread and
1283 * store the current valid flag. (It may have been changed
1284 * by e2fsck since we originally mounted the partition.)
1285 */
1286 sbi->s_mount_state = le16_to_cpu(es->s_state);
1287 if (!ext2_setup_super (sb, es, 0))
1288 sb->s_flags &= ~MS_RDONLY;
1289 }
1290 ext2_sync_super(sb, es);
1291 unlock_kernel();
1292 return 0;
1293 restore_opts:
1294 sbi->s_mount_opt = old_opts.s_mount_opt;
1295 sbi->s_resuid = old_opts.s_resuid;
1296 sbi->s_resgid = old_opts.s_resgid;
1297 sb->s_flags = old_sb_flags;
1298 unlock_kernel();
1299 return err;
1300 }
1301
1302 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1303 {
1304 struct super_block *sb = dentry->d_sb;
1305 struct ext2_sb_info *sbi = EXT2_SB(sb);
1306 struct ext2_super_block *es = sbi->s_es;
1307 u64 fsid;
1308
1309 if (test_opt (sb, MINIX_DF))
1310 sbi->s_overhead_last = 0;
1311 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1312 unsigned long i, overhead = 0;
1313 smp_rmb();
1314
1315 /*
1316 * Compute the overhead (FS structures). This is constant
1317 * for a given filesystem unless the number of block groups
1318 * changes so we cache the previous value until it does.
1319 */
1320
1321 /*
1322 * All of the blocks before first_data_block are
1323 * overhead
1324 */
1325 overhead = le32_to_cpu(es->s_first_data_block);
1326
1327 /*
1328 * Add the overhead attributed to the superblock and
1329 * block group descriptors. If the sparse superblocks
1330 * feature is turned on, then not all groups have this.
1331 */
1332 for (i = 0; i < sbi->s_groups_count; i++)
1333 overhead += ext2_bg_has_super(sb, i) +
1334 ext2_bg_num_gdb(sb, i);
1335
1336 /*
1337 * Every block group has an inode bitmap, a block
1338 * bitmap, and an inode table.
1339 */
1340 overhead += (sbi->s_groups_count *
1341 (2 + sbi->s_itb_per_group));
1342 sbi->s_overhead_last = overhead;
1343 smp_wmb();
1344 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1345 }
1346
1347 buf->f_type = EXT2_SUPER_MAGIC;
1348 buf->f_bsize = sb->s_blocksize;
1349 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1350 buf->f_bfree = ext2_count_free_blocks(sb);
1351 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1352 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1353 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1354 buf->f_bavail = 0;
1355 buf->f_files = le32_to_cpu(es->s_inodes_count);
1356 buf->f_ffree = ext2_count_free_inodes(sb);
1357 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1358 buf->f_namelen = EXT2_NAME_LEN;
1359 fsid = le64_to_cpup((void *)es->s_uuid) ^
1360 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1361 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1362 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1363 return 0;
1364 }
1365
1366 static int ext2_get_sb(struct file_system_type *fs_type,
1367 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1368 {
1369 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1370 }
1371
1372 #ifdef CONFIG_QUOTA
1373
1374 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1375 * acquiring the locks... As quota files are never truncated and quota code
1376 * itself serializes the operations (and noone else should touch the files)
1377 * we don't have to be afraid of races */
1378 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1379 size_t len, loff_t off)
1380 {
1381 struct inode *inode = sb_dqopt(sb)->files[type];
1382 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1383 int err = 0;
1384 int offset = off & (sb->s_blocksize - 1);
1385 int tocopy;
1386 size_t toread;
1387 struct buffer_head tmp_bh;
1388 struct buffer_head *bh;
1389 loff_t i_size = i_size_read(inode);
1390
1391 if (off > i_size)
1392 return 0;
1393 if (off+len > i_size)
1394 len = i_size-off;
1395 toread = len;
1396 while (toread > 0) {
1397 tocopy = sb->s_blocksize - offset < toread ?
1398 sb->s_blocksize - offset : toread;
1399
1400 tmp_bh.b_state = 0;
1401 tmp_bh.b_size = sb->s_blocksize;
1402 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1403 if (err < 0)
1404 return err;
1405 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1406 memset(data, 0, tocopy);
1407 else {
1408 bh = sb_bread(sb, tmp_bh.b_blocknr);
1409 if (!bh)
1410 return -EIO;
1411 memcpy(data, bh->b_data+offset, tocopy);
1412 brelse(bh);
1413 }
1414 offset = 0;
1415 toread -= tocopy;
1416 data += tocopy;
1417 blk++;
1418 }
1419 return len;
1420 }
1421
1422 /* Write to quotafile */
1423 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1424 const char *data, size_t len, loff_t off)
1425 {
1426 struct inode *inode = sb_dqopt(sb)->files[type];
1427 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1428 int err = 0;
1429 int offset = off & (sb->s_blocksize - 1);
1430 int tocopy;
1431 size_t towrite = len;
1432 struct buffer_head tmp_bh;
1433 struct buffer_head *bh;
1434
1435 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1436 while (towrite > 0) {
1437 tocopy = sb->s_blocksize - offset < towrite ?
1438 sb->s_blocksize - offset : towrite;
1439
1440 tmp_bh.b_state = 0;
1441 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1442 if (err < 0)
1443 goto out;
1444 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1445 bh = sb_bread(sb, tmp_bh.b_blocknr);
1446 else
1447 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1448 if (!bh) {
1449 err = -EIO;
1450 goto out;
1451 }
1452 lock_buffer(bh);
1453 memcpy(bh->b_data+offset, data, tocopy);
1454 flush_dcache_page(bh->b_page);
1455 set_buffer_uptodate(bh);
1456 mark_buffer_dirty(bh);
1457 unlock_buffer(bh);
1458 brelse(bh);
1459 offset = 0;
1460 towrite -= tocopy;
1461 data += tocopy;
1462 blk++;
1463 }
1464 out:
1465 if (len == towrite) {
1466 mutex_unlock(&inode->i_mutex);
1467 return err;
1468 }
1469 if (inode->i_size < off+len-towrite)
1470 i_size_write(inode, off+len-towrite);
1471 inode->i_version++;
1472 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1473 mark_inode_dirty(inode);
1474 mutex_unlock(&inode->i_mutex);
1475 return len - towrite;
1476 }
1477
1478 #endif
1479
1480 static struct file_system_type ext2_fs_type = {
1481 .owner = THIS_MODULE,
1482 .name = "ext2",
1483 .get_sb = ext2_get_sb,
1484 .kill_sb = kill_block_super,
1485 .fs_flags = FS_REQUIRES_DEV,
1486 };
1487
1488 static int __init init_ext2_fs(void)
1489 {
1490 int err = init_ext2_xattr();
1491 if (err)
1492 return err;
1493 err = init_inodecache();
1494 if (err)
1495 goto out1;
1496 err = register_filesystem(&ext2_fs_type);
1497 if (err)
1498 goto out;
1499 return 0;
1500 out:
1501 destroy_inodecache();
1502 out1:
1503 exit_ext2_xattr();
1504 return err;
1505 }
1506
1507 static void __exit exit_ext2_fs(void)
1508 {
1509 unregister_filesystem(&ext2_fs_type);
1510 destroy_inodecache();
1511 exit_ext2_xattr();
1512 }
1513
1514 module_init(init_ext2_fs)
1515 module_exit(exit_ext2_fs)
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