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perf_counter, x86: rework counter disable functions
[linux-2.6/mini2440.git] / fs / ext2 / super.c
blob5c4afe652245a9d045825f26f3ad3dbe0a06e13a
1 /*
2 * linux/fs/ext2/super.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/inode.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Big-endian to little-endian byte-swapping/bitmaps by
16 * David S. Miller (davem@caip.rutgers.edu), 1995
17 */
18
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/slab.h>
23 #include <linux/init.h>
24 #include <linux/blkdev.h>
25 #include <linux/parser.h>
26 #include <linux/random.h>
27 #include <linux/buffer_head.h>
28 #include <linux/exportfs.h>
29 #include <linux/smp_lock.h>
30 #include <linux/vfs.h>
31 #include <linux/seq_file.h>
32 #include <linux/mount.h>
33 #include <linux/log2.h>
34 #include <linux/quotaops.h>
35 #include <asm/uaccess.h>
36 #include "ext2.h"
37 #include "xattr.h"
38 #include "acl.h"
39 #include "xip.h"
40
41 static void ext2_sync_super(struct super_block *sb,
42 struct ext2_super_block *es);
43 static int ext2_remount (struct super_block * sb, int * flags, char * data);
44 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
45
46 void ext2_error (struct super_block * sb, const char * function,
47 const char * fmt, ...)
48 {
49 va_list args;
50 struct ext2_sb_info *sbi = EXT2_SB(sb);
51 struct ext2_super_block *es = sbi->s_es;
52
53 if (!(sb->s_flags & MS_RDONLY)) {
54 sbi->s_mount_state |= EXT2_ERROR_FS;
55 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
56 ext2_sync_super(sb, es);
57 }
58
59 va_start(args, fmt);
60 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
61 vprintk(fmt, args);
62 printk("\n");
63 va_end(args);
64
65 if (test_opt(sb, ERRORS_PANIC))
66 panic("EXT2-fs panic from previous error\n");
67 if (test_opt(sb, ERRORS_RO)) {
68 printk("Remounting filesystem read-only\n");
69 sb->s_flags |= MS_RDONLY;
70 }
71 }
72
73 void ext2_warning (struct super_block * sb, const char * function,
74 const char * fmt, ...)
75 {
76 va_list args;
77
78 va_start(args, fmt);
79 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
80 sb->s_id, function);
81 vprintk(fmt, args);
82 printk("\n");
83 va_end(args);
84 }
85
86 void ext2_update_dynamic_rev(struct super_block *sb)
87 {
88 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
89
90 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
91 return;
92
93 ext2_warning(sb, __func__,
94 "updating to rev %d because of new feature flag, "
95 "running e2fsck is recommended",
96 EXT2_DYNAMIC_REV);
97
98 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
99 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
100 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
101 /* leave es->s_feature_*compat flags alone */
102 /* es->s_uuid will be set by e2fsck if empty */
103
104 /*
105 * The rest of the superblock fields should be zero, and if not it
106 * means they are likely already in use, so leave them alone. We
107 * can leave it up to e2fsck to clean up any inconsistencies there.
108 */
109 }
110
111 static void ext2_put_super (struct super_block * sb)
112 {
113 int db_count;
114 int i;
115 struct ext2_sb_info *sbi = EXT2_SB(sb);
116
117 ext2_xattr_put_super(sb);
118 if (!(sb->s_flags & MS_RDONLY)) {
119 struct ext2_super_block *es = sbi->s_es;
120
121 es->s_state = cpu_to_le16(sbi->s_mount_state);
122 ext2_sync_super(sb, es);
123 }
124 db_count = sbi->s_gdb_count;
125 for (i = 0; i < db_count; i++)
126 if (sbi->s_group_desc[i])
127 brelse (sbi->s_group_desc[i]);
128 kfree(sbi->s_group_desc);
129 kfree(sbi->s_debts);
130 percpu_counter_destroy(&sbi->s_freeblocks_counter);
131 percpu_counter_destroy(&sbi->s_freeinodes_counter);
132 percpu_counter_destroy(&sbi->s_dirs_counter);
133 brelse (sbi->s_sbh);
134 sb->s_fs_info = NULL;
135 kfree(sbi->s_blockgroup_lock);
136 kfree(sbi);
137
138 return;
139 }
140
141 static struct kmem_cache * ext2_inode_cachep;
142
143 static struct inode *ext2_alloc_inode(struct super_block *sb)
144 {
145 struct ext2_inode_info *ei;
146 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
147 if (!ei)
148 return NULL;
149 #ifdef CONFIG_EXT2_FS_POSIX_ACL
150 ei->i_acl = EXT2_ACL_NOT_CACHED;
151 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
152 #endif
153 ei->i_block_alloc_info = NULL;
154 ei->vfs_inode.i_version = 1;
155 return &ei->vfs_inode;
156 }
157
158 static void ext2_destroy_inode(struct inode *inode)
159 {
160 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
161 }
162
163 static void init_once(void *foo)
164 {
165 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
166
167 rwlock_init(&ei->i_meta_lock);
168 #ifdef CONFIG_EXT2_FS_XATTR
169 init_rwsem(&ei->xattr_sem);
170 #endif
171 mutex_init(&ei->truncate_mutex);
172 inode_init_once(&ei->vfs_inode);
173 }
174
175 static int init_inodecache(void)
176 {
177 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
178 sizeof(struct ext2_inode_info),
179 0, (SLAB_RECLAIM_ACCOUNT|
180 SLAB_MEM_SPREAD),
181 init_once);
182 if (ext2_inode_cachep == NULL)
183 return -ENOMEM;
184 return 0;
185 }
186
187 static void destroy_inodecache(void)
188 {
189 kmem_cache_destroy(ext2_inode_cachep);
190 }
191
192 static void ext2_clear_inode(struct inode *inode)
193 {
194 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
195 #ifdef CONFIG_EXT2_FS_POSIX_ACL
196 struct ext2_inode_info *ei = EXT2_I(inode);
197
198 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
199 posix_acl_release(ei->i_acl);
200 ei->i_acl = EXT2_ACL_NOT_CACHED;
201 }
202 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
203 posix_acl_release(ei->i_default_acl);
204 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
205 }
206 #endif
207 ext2_discard_reservation(inode);
208 EXT2_I(inode)->i_block_alloc_info = NULL;
209 if (unlikely(rsv))
210 kfree(rsv);
211 }
212
213 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
214 {
215 struct super_block *sb = vfs->mnt_sb;
216 struct ext2_sb_info *sbi = EXT2_SB(sb);
217 struct ext2_super_block *es = sbi->s_es;
218 unsigned long def_mount_opts;
219
220 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
221
222 if (sbi->s_sb_block != 1)
223 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
224 if (test_opt(sb, MINIX_DF))
225 seq_puts(seq, ",minixdf");
226 if (test_opt(sb, GRPID))
227 seq_puts(seq, ",grpid");
228 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
229 seq_puts(seq, ",nogrpid");
230 if (sbi->s_resuid != EXT2_DEF_RESUID ||
231 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
232 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
233 }
234 if (sbi->s_resgid != EXT2_DEF_RESGID ||
235 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
236 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
237 }
238 if (test_opt(sb, ERRORS_RO)) {
239 int def_errors = le16_to_cpu(es->s_errors);
240
241 if (def_errors == EXT2_ERRORS_PANIC ||
242 def_errors == EXT2_ERRORS_CONTINUE) {
243 seq_puts(seq, ",errors=remount-ro");
244 }
245 }
246 if (test_opt(sb, ERRORS_CONT))
247 seq_puts(seq, ",errors=continue");
248 if (test_opt(sb, ERRORS_PANIC))
249 seq_puts(seq, ",errors=panic");
250 if (test_opt(sb, NO_UID32))
251 seq_puts(seq, ",nouid32");
252 if (test_opt(sb, DEBUG))
253 seq_puts(seq, ",debug");
254 if (test_opt(sb, OLDALLOC))
255 seq_puts(seq, ",oldalloc");
256
257 #ifdef CONFIG_EXT2_FS_XATTR
258 if (test_opt(sb, XATTR_USER))
259 seq_puts(seq, ",user_xattr");
260 if (!test_opt(sb, XATTR_USER) &&
261 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
262 seq_puts(seq, ",nouser_xattr");
263 }
264 #endif
265
266 #ifdef CONFIG_EXT2_FS_POSIX_ACL
267 if (test_opt(sb, POSIX_ACL))
268 seq_puts(seq, ",acl");
269 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
270 seq_puts(seq, ",noacl");
271 #endif
272
273 if (test_opt(sb, NOBH))
274 seq_puts(seq, ",nobh");
275
276 #if defined(CONFIG_QUOTA)
277 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
278 seq_puts(seq, ",usrquota");
279
280 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
281 seq_puts(seq, ",grpquota");
282 #endif
283
284 #if defined(CONFIG_EXT2_FS_XIP)
285 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
286 seq_puts(seq, ",xip");
287 #endif
288
289 if (!test_opt(sb, RESERVATION))
290 seq_puts(seq, ",noreservation");
291
292 return 0;
293 }
294
295 #ifdef CONFIG_QUOTA
296 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
297 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
298 #endif
299
300 static const struct super_operations ext2_sops = {
301 .alloc_inode = ext2_alloc_inode,
302 .destroy_inode = ext2_destroy_inode,
303 .write_inode = ext2_write_inode,
304 .delete_inode = ext2_delete_inode,
305 .put_super = ext2_put_super,
306 .write_super = ext2_write_super,
307 .statfs = ext2_statfs,
308 .remount_fs = ext2_remount,
309 .clear_inode = ext2_clear_inode,
310 .show_options = ext2_show_options,
311 #ifdef CONFIG_QUOTA
312 .quota_read = ext2_quota_read,
313 .quota_write = ext2_quota_write,
314 #endif
315 };
316
317 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
318 u64 ino, u32 generation)
319 {
320 struct inode *inode;
321
322 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
323 return ERR_PTR(-ESTALE);
324 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
325 return ERR_PTR(-ESTALE);
326
327 /* iget isn't really right if the inode is currently unallocated!!
328 * ext2_read_inode currently does appropriate checks, but
329 * it might be "neater" to call ext2_get_inode first and check
330 * if the inode is valid.....
331 */
332 inode = ext2_iget(sb, ino);
333 if (IS_ERR(inode))
334 return ERR_CAST(inode);
335 if (generation && inode->i_generation != generation) {
336 /* we didn't find the right inode.. */
337 iput(inode);
338 return ERR_PTR(-ESTALE);
339 }
340 return inode;
341 }
342
343 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
344 int fh_len, int fh_type)
345 {
346 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
347 ext2_nfs_get_inode);
348 }
349
350 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
351 int fh_len, int fh_type)
352 {
353 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
354 ext2_nfs_get_inode);
355 }
356
357 /* Yes, most of these are left as NULL!!
358 * A NULL value implies the default, which works with ext2-like file
359 * systems, but can be improved upon.
360 * Currently only get_parent is required.
361 */
362 static const struct export_operations ext2_export_ops = {
363 .fh_to_dentry = ext2_fh_to_dentry,
364 .fh_to_parent = ext2_fh_to_parent,
365 .get_parent = ext2_get_parent,
366 };
367
368 static unsigned long get_sb_block(void **data)
369 {
370 unsigned long sb_block;
371 char *options = (char *) *data;
372
373 if (!options || strncmp(options, "sb=", 3) != 0)
374 return 1; /* Default location */
375 options += 3;
376 sb_block = simple_strtoul(options, &options, 0);
377 if (*options && *options != ',') {
378 printk("EXT2-fs: Invalid sb specification: %s\n",
379 (char *) *data);
380 return 1;
381 }
382 if (*options == ',')
383 options++;
384 *data = (void *) options;
385 return sb_block;
386 }
387
388 enum {
389 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
390 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
391 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
392 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
393 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
394 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
395 };
396
397 static const match_table_t tokens = {
398 {Opt_bsd_df, "bsddf"},
399 {Opt_minix_df, "minixdf"},
400 {Opt_grpid, "grpid"},
401 {Opt_grpid, "bsdgroups"},
402 {Opt_nogrpid, "nogrpid"},
403 {Opt_nogrpid, "sysvgroups"},
404 {Opt_resgid, "resgid=%u"},
405 {Opt_resuid, "resuid=%u"},
406 {Opt_sb, "sb=%u"},
407 {Opt_err_cont, "errors=continue"},
408 {Opt_err_panic, "errors=panic"},
409 {Opt_err_ro, "errors=remount-ro"},
410 {Opt_nouid32, "nouid32"},
411 {Opt_nocheck, "check=none"},
412 {Opt_nocheck, "nocheck"},
413 {Opt_debug, "debug"},
414 {Opt_oldalloc, "oldalloc"},
415 {Opt_orlov, "orlov"},
416 {Opt_nobh, "nobh"},
417 {Opt_user_xattr, "user_xattr"},
418 {Opt_nouser_xattr, "nouser_xattr"},
419 {Opt_acl, "acl"},
420 {Opt_noacl, "noacl"},
421 {Opt_xip, "xip"},
422 {Opt_grpquota, "grpquota"},
423 {Opt_ignore, "noquota"},
424 {Opt_quota, "quota"},
425 {Opt_usrquota, "usrquota"},
426 {Opt_reservation, "reservation"},
427 {Opt_noreservation, "noreservation"},
428 {Opt_err, NULL}
429 };
430
431 static int parse_options (char * options,
432 struct ext2_sb_info *sbi)
433 {
434 char * p;
435 substring_t args[MAX_OPT_ARGS];
436 int option;
437
438 if (!options)
439 return 1;
440
441 while ((p = strsep (&options, ",")) != NULL) {
442 int token;
443 if (!*p)
444 continue;
445
446 token = match_token(p, tokens, args);
447 switch (token) {
448 case Opt_bsd_df:
449 clear_opt (sbi->s_mount_opt, MINIX_DF);
450 break;
451 case Opt_minix_df:
452 set_opt (sbi->s_mount_opt, MINIX_DF);
453 break;
454 case Opt_grpid:
455 set_opt (sbi->s_mount_opt, GRPID);
456 break;
457 case Opt_nogrpid:
458 clear_opt (sbi->s_mount_opt, GRPID);
459 break;
460 case Opt_resuid:
461 if (match_int(&args[0], &option))
462 return 0;
463 sbi->s_resuid = option;
464 break;
465 case Opt_resgid:
466 if (match_int(&args[0], &option))
467 return 0;
468 sbi->s_resgid = option;
469 break;
470 case Opt_sb:
471 /* handled by get_sb_block() instead of here */
472 /* *sb_block = match_int(&args[0]); */
473 break;
474 case Opt_err_panic:
475 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
476 clear_opt (sbi->s_mount_opt, ERRORS_RO);
477 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
478 break;
479 case Opt_err_ro:
480 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
481 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
482 set_opt (sbi->s_mount_opt, ERRORS_RO);
483 break;
484 case Opt_err_cont:
485 clear_opt (sbi->s_mount_opt, ERRORS_RO);
486 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
487 set_opt (sbi->s_mount_opt, ERRORS_CONT);
488 break;
489 case Opt_nouid32:
490 set_opt (sbi->s_mount_opt, NO_UID32);
491 break;
492 case Opt_nocheck:
493 clear_opt (sbi->s_mount_opt, CHECK);
494 break;
495 case Opt_debug:
496 set_opt (sbi->s_mount_opt, DEBUG);
497 break;
498 case Opt_oldalloc:
499 set_opt (sbi->s_mount_opt, OLDALLOC);
500 break;
501 case Opt_orlov:
502 clear_opt (sbi->s_mount_opt, OLDALLOC);
503 break;
504 case Opt_nobh:
505 set_opt (sbi->s_mount_opt, NOBH);
506 break;
507 #ifdef CONFIG_EXT2_FS_XATTR
508 case Opt_user_xattr:
509 set_opt (sbi->s_mount_opt, XATTR_USER);
510 break;
511 case Opt_nouser_xattr:
512 clear_opt (sbi->s_mount_opt, XATTR_USER);
513 break;
514 #else
515 case Opt_user_xattr:
516 case Opt_nouser_xattr:
517 printk("EXT2 (no)user_xattr options not supported\n");
518 break;
519 #endif
520 #ifdef CONFIG_EXT2_FS_POSIX_ACL
521 case Opt_acl:
522 set_opt(sbi->s_mount_opt, POSIX_ACL);
523 break;
524 case Opt_noacl:
525 clear_opt(sbi->s_mount_opt, POSIX_ACL);
526 break;
527 #else
528 case Opt_acl:
529 case Opt_noacl:
530 printk("EXT2 (no)acl options not supported\n");
531 break;
532 #endif
533 case Opt_xip:
534 #ifdef CONFIG_EXT2_FS_XIP
535 set_opt (sbi->s_mount_opt, XIP);
536 #else
537 printk("EXT2 xip option not supported\n");
538 #endif
539 break;
540
541 #if defined(CONFIG_QUOTA)
542 case Opt_quota:
543 case Opt_usrquota:
544 set_opt(sbi->s_mount_opt, USRQUOTA);
545 break;
546
547 case Opt_grpquota:
548 set_opt(sbi->s_mount_opt, GRPQUOTA);
549 break;
550 #else
551 case Opt_quota:
552 case Opt_usrquota:
553 case Opt_grpquota:
554 printk(KERN_ERR
555 "EXT2-fs: quota operations not supported.\n");
556
557 break;
558 #endif
559
560 case Opt_reservation:
561 set_opt(sbi->s_mount_opt, RESERVATION);
562 printk("reservations ON\n");
563 break;
564 case Opt_noreservation:
565 clear_opt(sbi->s_mount_opt, RESERVATION);
566 printk("reservations OFF\n");
567 break;
568 case Opt_ignore:
569 break;
570 default:
571 return 0;
572 }
573 }
574 return 1;
575 }
576
577 static int ext2_setup_super (struct super_block * sb,
578 struct ext2_super_block * es,
579 int read_only)
580 {
581 int res = 0;
582 struct ext2_sb_info *sbi = EXT2_SB(sb);
583
584 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
585 printk ("EXT2-fs warning: revision level too high, "
586 "forcing read-only mode\n");
587 res = MS_RDONLY;
588 }
589 if (read_only)
590 return res;
591 if (!(sbi->s_mount_state & EXT2_VALID_FS))
592 printk ("EXT2-fs warning: mounting unchecked fs, "
593 "running e2fsck is recommended\n");
594 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
595 printk ("EXT2-fs warning: mounting fs with errors, "
596 "running e2fsck is recommended\n");
597 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
598 le16_to_cpu(es->s_mnt_count) >=
599 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
600 printk ("EXT2-fs warning: maximal mount count reached, "
601 "running e2fsck is recommended\n");
602 else if (le32_to_cpu(es->s_checkinterval) &&
603 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
604 printk ("EXT2-fs warning: checktime reached, "
605 "running e2fsck is recommended\n");
606 if (!le16_to_cpu(es->s_max_mnt_count))
607 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
608 le16_add_cpu(&es->s_mnt_count, 1);
609 ext2_write_super(sb);
610 if (test_opt (sb, DEBUG))
611 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
612 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
613 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
614 sbi->s_frag_size,
615 sbi->s_groups_count,
616 EXT2_BLOCKS_PER_GROUP(sb),
617 EXT2_INODES_PER_GROUP(sb),
618 sbi->s_mount_opt);
619 return res;
620 }
621
622 static int ext2_check_descriptors(struct super_block *sb)
623 {
624 int i;
625 struct ext2_sb_info *sbi = EXT2_SB(sb);
626
627 ext2_debug ("Checking group descriptors");
628
629 for (i = 0; i < sbi->s_groups_count; i++) {
630 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
631 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
632 ext2_fsblk_t last_block;
633
634 if (i == sbi->s_groups_count - 1)
635 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
636 else
637 last_block = first_block +
638 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
639
640 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
641 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
642 {
643 ext2_error (sb, "ext2_check_descriptors",
644 "Block bitmap for group %d"
645 " not in group (block %lu)!",
646 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
647 return 0;
648 }
649 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
650 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
651 {
652 ext2_error (sb, "ext2_check_descriptors",
653 "Inode bitmap for group %d"
654 " not in group (block %lu)!",
655 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
656 return 0;
657 }
658 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
659 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
660 last_block)
661 {
662 ext2_error (sb, "ext2_check_descriptors",
663 "Inode table for group %d"
664 " not in group (block %lu)!",
665 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
666 return 0;
667 }
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_meta_bg;
725 int has_super = 0;
726
727 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
728
729 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
730 nr < first_meta_bg)
731 return (logic_sb_block + nr + 1);
732 bg = sbi->s_desc_per_block * nr;
733 if (ext2_bg_has_super(sb, bg))
734 has_super = 1;
735
736 return ext2_group_first_block_no(sb, bg) + has_super;
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
761 sbi->s_blockgroup_lock =
762 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
763 if (!sbi->s_blockgroup_lock) {
764 kfree(sbi);
765 return -ENOMEM;
766 }
767 sb->s_fs_info = sbi;
768 sbi->s_sb_block = sb_block;
769
770 /*
771 * See what the current blocksize for the device is, and
772 * use that as the blocksize. Otherwise (or if the blocksize
773 * is smaller than the default) use the default.
774 * This is important for devices that have a hardware
775 * sectorsize that is larger than the default.
776 */
777 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
778 if (!blocksize) {
779 printk ("EXT2-fs: unable to set blocksize\n");
780 goto failed_sbi;
781 }
782
783 /*
784 * If the superblock doesn't start on a hardware sector boundary,
785 * calculate the offset.
786 */
787 if (blocksize != BLOCK_SIZE) {
788 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
789 offset = (sb_block*BLOCK_SIZE) % blocksize;
790 } else {
791 logic_sb_block = sb_block;
792 }
793
794 if (!(bh = sb_bread(sb, logic_sb_block))) {
795 printk ("EXT2-fs: unable to read superblock\n");
796 goto failed_sbi;
797 }
798 /*
799 * Note: s_es must be initialized as soon as possible because
800 * some ext2 macro-instructions depend on its value
801 */
802 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
803 sbi->s_es = es;
804 sb->s_magic = le16_to_cpu(es->s_magic);
805
806 if (sb->s_magic != EXT2_SUPER_MAGIC)
807 goto cantfind_ext2;
808
809 /* Set defaults before we parse the mount options */
810 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
811 if (def_mount_opts & EXT2_DEFM_DEBUG)
812 set_opt(sbi->s_mount_opt, DEBUG);
813 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
814 set_opt(sbi->s_mount_opt, GRPID);
815 if (def_mount_opts & EXT2_DEFM_UID16)
816 set_opt(sbi->s_mount_opt, NO_UID32);
817 #ifdef CONFIG_EXT2_FS_XATTR
818 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
819 set_opt(sbi->s_mount_opt, XATTR_USER);
820 #endif
821 #ifdef CONFIG_EXT2_FS_POSIX_ACL
822 if (def_mount_opts & EXT2_DEFM_ACL)
823 set_opt(sbi->s_mount_opt, POSIX_ACL);
824 #endif
825
826 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
827 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
828 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
829 set_opt(sbi->s_mount_opt, ERRORS_CONT);
830 else
831 set_opt(sbi->s_mount_opt, ERRORS_RO);
832
833 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
834 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
835
836 set_opt(sbi->s_mount_opt, RESERVATION);
837
838 if (!parse_options ((char *) data, sbi))
839 goto failed_mount;
840
841 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
842 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
843 MS_POSIXACL : 0);
844
845 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
846 EXT2_MOUNT_XIP if not */
847
848 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
849 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
850 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
851 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
852 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
853 "running e2fsck is recommended\n");
854 /*
855 * Check feature flags regardless of the revision level, since we
856 * previously didn't change the revision level when setting the flags,
857 * so there is a chance incompat flags are set on a rev 0 filesystem.
858 */
859 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
860 if (features) {
861 printk("EXT2-fs: %s: couldn't mount because of "
862 "unsupported optional features (%x).\n",
863 sb->s_id, le32_to_cpu(features));
864 goto failed_mount;
865 }
866 if (!(sb->s_flags & MS_RDONLY) &&
867 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
868 printk("EXT2-fs: %s: couldn't mount RDWR because of "
869 "unsupported optional features (%x).\n",
870 sb->s_id, le32_to_cpu(features));
871 goto failed_mount;
872 }
873
874 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
875
876 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
877 if (!silent)
878 printk("XIP: Unsupported blocksize\n");
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 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
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 printk("EXT2-fs: Couldn't read superblock on "
896 "2nd try.\n");
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 printk ("EXT2-fs: Magic mismatch, very weird !\n");
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 printk ("EXT2-fs: unsupported inode size: %d\n",
919 sbi->s_inode_size);
920 goto failed_mount;
921 }
922 }
923
924 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
925 le32_to_cpu(es->s_log_frag_size);
926 if (sbi->s_frag_size == 0)
927 goto cantfind_ext2;
928 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
929
930 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
931 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
932 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
933
934 if (EXT2_INODE_SIZE(sb) == 0)
935 goto cantfind_ext2;
936 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
937 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
938 goto cantfind_ext2;
939 sbi->s_itb_per_group = sbi->s_inodes_per_group /
940 sbi->s_inodes_per_block;
941 sbi->s_desc_per_block = sb->s_blocksize /
942 sizeof (struct ext2_group_desc);
943 sbi->s_sbh = bh;
944 sbi->s_mount_state = le16_to_cpu(es->s_state);
945 sbi->s_addr_per_block_bits =
946 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
947 sbi->s_desc_per_block_bits =
948 ilog2 (EXT2_DESC_PER_BLOCK(sb));
949
950 if (sb->s_magic != EXT2_SUPER_MAGIC)
951 goto cantfind_ext2;
952
953 if (sb->s_blocksize != bh->b_size) {
954 if (!silent)
955 printk ("VFS: Unsupported blocksize on dev "
956 "%s.\n", sb->s_id);
957 goto failed_mount;
958 }
959
960 if (sb->s_blocksize != sbi->s_frag_size) {
961 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
962 sbi->s_frag_size, sb->s_blocksize);
963 goto failed_mount;
964 }
965
966 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
967 printk ("EXT2-fs: #blocks per group too big: %lu\n",
968 sbi->s_blocks_per_group);
969 goto failed_mount;
970 }
971 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
972 printk ("EXT2-fs: #fragments per group too big: %lu\n",
973 sbi->s_frags_per_group);
974 goto failed_mount;
975 }
976 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
977 printk ("EXT2-fs: #inodes per group too big: %lu\n",
978 sbi->s_inodes_per_group);
979 goto failed_mount;
980 }
981
982 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
983 goto cantfind_ext2;
984 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
985 le32_to_cpu(es->s_first_data_block) - 1)
986 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
987 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
988 EXT2_DESC_PER_BLOCK(sb);
989 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
990 if (sbi->s_group_desc == NULL) {
991 printk ("EXT2-fs: not enough memory\n");
992 goto failed_mount;
993 }
994 bgl_lock_init(sbi->s_blockgroup_lock);
995 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
996 if (!sbi->s_debts) {
997 printk ("EXT2-fs: not enough memory\n");
998 goto failed_mount_group_desc;
999 }
1000 for (i = 0; i < db_count; i++) {
1001 block = descriptor_loc(sb, logic_sb_block, i);
1002 sbi->s_group_desc[i] = sb_bread(sb, block);
1003 if (!sbi->s_group_desc[i]) {
1004 for (j = 0; j < i; j++)
1005 brelse (sbi->s_group_desc[j]);
1006 printk ("EXT2-fs: unable to read group descriptors\n");
1007 goto failed_mount_group_desc;
1008 }
1009 }
1010 if (!ext2_check_descriptors (sb)) {
1011 printk ("EXT2-fs: group descriptors corrupted!\n");
1012 goto failed_mount2;
1013 }
1014 sbi->s_gdb_count = db_count;
1015 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1016 spin_lock_init(&sbi->s_next_gen_lock);
1017
1018 /* per fileystem reservation list head & lock */
1019 spin_lock_init(&sbi->s_rsv_window_lock);
1020 sbi->s_rsv_window_root = RB_ROOT;
1021 /*
1022 * Add a single, static dummy reservation to the start of the
1023 * reservation window list --- it gives us a placeholder for
1024 * append-at-start-of-list which makes the allocation logic
1025 * _much_ simpler.
1026 */
1027 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1028 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1029 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1030 sbi->s_rsv_window_head.rsv_goal_size = 0;
1031 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1032
1033 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1034 ext2_count_free_blocks(sb));
1035 if (!err) {
1036 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1037 ext2_count_free_inodes(sb));
1038 }
1039 if (!err) {
1040 err = percpu_counter_init(&sbi->s_dirs_counter,
1041 ext2_count_dirs(sb));
1042 }
1043 if (err) {
1044 printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1045 goto failed_mount3;
1046 }
1047 /*
1048 * set up enough so that it can read an inode
1049 */
1050 sb->s_op = &ext2_sops;
1051 sb->s_export_op = &ext2_export_ops;
1052 sb->s_xattr = ext2_xattr_handlers;
1053 root = ext2_iget(sb, EXT2_ROOT_INO);
1054 if (IS_ERR(root)) {
1055 ret = PTR_ERR(root);
1056 goto failed_mount3;
1057 }
1058 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1059 iput(root);
1060 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1061 goto failed_mount3;
1062 }
1063
1064 sb->s_root = d_alloc_root(root);
1065 if (!sb->s_root) {
1066 iput(root);
1067 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1068 ret = -ENOMEM;
1069 goto failed_mount3;
1070 }
1071 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1072 ext2_warning(sb, __func__,
1073 "mounting ext3 filesystem as ext2");
1074 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1075 return 0;
1076
1077 cantfind_ext2:
1078 if (!silent)
1079 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1080 sb->s_id);
1081 goto failed_mount;
1082 failed_mount3:
1083 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1084 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1085 percpu_counter_destroy(&sbi->s_dirs_counter);
1086 failed_mount2:
1087 for (i = 0; i < db_count; i++)
1088 brelse(sbi->s_group_desc[i]);
1089 failed_mount_group_desc:
1090 kfree(sbi->s_group_desc);
1091 kfree(sbi->s_debts);
1092 failed_mount:
1093 brelse(bh);
1094 failed_sbi:
1095 sb->s_fs_info = NULL;
1096 kfree(sbi);
1097 return ret;
1098 }
1099
1100 static void ext2_commit_super (struct super_block * sb,
1101 struct ext2_super_block * es)
1102 {
1103 es->s_wtime = cpu_to_le32(get_seconds());
1104 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1105 sb->s_dirt = 0;
1106 }
1107
1108 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1109 {
1110 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1111 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1112 es->s_wtime = cpu_to_le32(get_seconds());
1113 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1114 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1115 sb->s_dirt = 0;
1116 }
1117
1118 /*
1119 * In the second extended file system, it is not necessary to
1120 * write the super block since we use a mapping of the
1121 * disk super block in a buffer.
1122 *
1123 * However, this function is still used to set the fs valid
1124 * flags to 0. We need to set this flag to 0 since the fs
1125 * may have been checked while mounted and e2fsck may have
1126 * set s_state to EXT2_VALID_FS after some corrections.
1127 */
1128
1129 void ext2_write_super (struct super_block * sb)
1130 {
1131 struct ext2_super_block * es;
1132 lock_kernel();
1133 if (!(sb->s_flags & MS_RDONLY)) {
1134 es = EXT2_SB(sb)->s_es;
1135
1136 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1137 ext2_debug ("setting valid to 0\n");
1138 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1139 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1140 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1141 es->s_mtime = cpu_to_le32(get_seconds());
1142 ext2_sync_super(sb, es);
1143 } else
1144 ext2_commit_super (sb, es);
1145 }
1146 sb->s_dirt = 0;
1147 unlock_kernel();
1148 }
1149
1150 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1151 {
1152 struct ext2_sb_info * sbi = EXT2_SB(sb);
1153 struct ext2_super_block * es;
1154 unsigned long old_mount_opt = sbi->s_mount_opt;
1155 struct ext2_mount_options old_opts;
1156 unsigned long old_sb_flags;
1157 int err;
1158
1159 /* Store the old options */
1160 old_sb_flags = sb->s_flags;
1161 old_opts.s_mount_opt = sbi->s_mount_opt;
1162 old_opts.s_resuid = sbi->s_resuid;
1163 old_opts.s_resgid = sbi->s_resgid;
1164
1165 /*
1166 * Allow the "check" option to be passed as a remount option.
1167 */
1168 if (!parse_options (data, sbi)) {
1169 err = -EINVAL;
1170 goto restore_opts;
1171 }
1172
1173 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1174 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1175
1176 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1177 EXT2_MOUNT_XIP if not */
1178
1179 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1180 printk("XIP: Unsupported blocksize\n");
1181 err = -EINVAL;
1182 goto restore_opts;
1183 }
1184
1185 es = sbi->s_es;
1186 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1187 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1188 invalidate_inodes(sb)) {
1189 ext2_warning(sb, __func__, "refusing change of xip flag "
1190 "with busy inodes while remounting");
1191 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1192 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1193 }
1194 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1195 return 0;
1196 if (*flags & MS_RDONLY) {
1197 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1198 !(sbi->s_mount_state & EXT2_VALID_FS))
1199 return 0;
1200 /*
1201 * OK, we are remounting a valid rw partition rdonly, so set
1202 * the rdonly flag and then mark the partition as valid again.
1203 */
1204 es->s_state = cpu_to_le16(sbi->s_mount_state);
1205 es->s_mtime = cpu_to_le32(get_seconds());
1206 } else {
1207 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1208 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1209 if (ret) {
1210 printk("EXT2-fs: %s: couldn't remount RDWR because of "
1211 "unsupported optional features (%x).\n",
1212 sb->s_id, le32_to_cpu(ret));
1213 err = -EROFS;
1214 goto restore_opts;
1215 }
1216 /*
1217 * Mounting a RDONLY partition read-write, so reread and
1218 * store the current valid flag. (It may have been changed
1219 * by e2fsck since we originally mounted the partition.)
1220 */
1221 sbi->s_mount_state = le16_to_cpu(es->s_state);
1222 if (!ext2_setup_super (sb, es, 0))
1223 sb->s_flags &= ~MS_RDONLY;
1224 }
1225 ext2_sync_super(sb, es);
1226 return 0;
1227 restore_opts:
1228 sbi->s_mount_opt = old_opts.s_mount_opt;
1229 sbi->s_resuid = old_opts.s_resuid;
1230 sbi->s_resgid = old_opts.s_resgid;
1231 sb->s_flags = old_sb_flags;
1232 return err;
1233 }
1234
1235 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1236 {
1237 struct super_block *sb = dentry->d_sb;
1238 struct ext2_sb_info *sbi = EXT2_SB(sb);
1239 struct ext2_super_block *es = sbi->s_es;
1240 u64 fsid;
1241
1242 if (test_opt (sb, MINIX_DF))
1243 sbi->s_overhead_last = 0;
1244 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1245 unsigned long i, overhead = 0;
1246 smp_rmb();
1247
1248 /*
1249 * Compute the overhead (FS structures). This is constant
1250 * for a given filesystem unless the number of block groups
1251 * changes so we cache the previous value until it does.
1252 */
1253
1254 /*
1255 * All of the blocks before first_data_block are
1256 * overhead
1257 */
1258 overhead = le32_to_cpu(es->s_first_data_block);
1259
1260 /*
1261 * Add the overhead attributed to the superblock and
1262 * block group descriptors. If the sparse superblocks
1263 * feature is turned on, then not all groups have this.
1264 */
1265 for (i = 0; i < sbi->s_groups_count; i++)
1266 overhead += ext2_bg_has_super(sb, i) +
1267 ext2_bg_num_gdb(sb, i);
1268
1269 /*
1270 * Every block group has an inode bitmap, a block
1271 * bitmap, and an inode table.
1272 */
1273 overhead += (sbi->s_groups_count *
1274 (2 + sbi->s_itb_per_group));
1275 sbi->s_overhead_last = overhead;
1276 smp_wmb();
1277 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1278 }
1279
1280 buf->f_type = EXT2_SUPER_MAGIC;
1281 buf->f_bsize = sb->s_blocksize;
1282 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1283 buf->f_bfree = ext2_count_free_blocks(sb);
1284 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1285 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1286 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1287 buf->f_bavail = 0;
1288 buf->f_files = le32_to_cpu(es->s_inodes_count);
1289 buf->f_ffree = ext2_count_free_inodes(sb);
1290 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1291 buf->f_namelen = EXT2_NAME_LEN;
1292 fsid = le64_to_cpup((void *)es->s_uuid) ^
1293 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1294 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1295 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1296 return 0;
1297 }
1298
1299 static int ext2_get_sb(struct file_system_type *fs_type,
1300 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1301 {
1302 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1303 }
1304
1305 #ifdef CONFIG_QUOTA
1306
1307 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1308 * acquiring the locks... As quota files are never truncated and quota code
1309 * itself serializes the operations (and noone else should touch the files)
1310 * we don't have to be afraid of races */
1311 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1312 size_t len, loff_t off)
1313 {
1314 struct inode *inode = sb_dqopt(sb)->files[type];
1315 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1316 int err = 0;
1317 int offset = off & (sb->s_blocksize - 1);
1318 int tocopy;
1319 size_t toread;
1320 struct buffer_head tmp_bh;
1321 struct buffer_head *bh;
1322 loff_t i_size = i_size_read(inode);
1323
1324 if (off > i_size)
1325 return 0;
1326 if (off+len > i_size)
1327 len = i_size-off;
1328 toread = len;
1329 while (toread > 0) {
1330 tocopy = sb->s_blocksize - offset < toread ?
1331 sb->s_blocksize - offset : toread;
1332
1333 tmp_bh.b_state = 0;
1334 tmp_bh.b_size = sb->s_blocksize;
1335 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1336 if (err < 0)
1337 return err;
1338 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1339 memset(data, 0, tocopy);
1340 else {
1341 bh = sb_bread(sb, tmp_bh.b_blocknr);
1342 if (!bh)
1343 return -EIO;
1344 memcpy(data, bh->b_data+offset, tocopy);
1345 brelse(bh);
1346 }
1347 offset = 0;
1348 toread -= tocopy;
1349 data += tocopy;
1350 blk++;
1351 }
1352 return len;
1353 }
1354
1355 /* Write to quotafile */
1356 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1357 const char *data, size_t len, loff_t off)
1358 {
1359 struct inode *inode = sb_dqopt(sb)->files[type];
1360 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1361 int err = 0;
1362 int offset = off & (sb->s_blocksize - 1);
1363 int tocopy;
1364 size_t towrite = len;
1365 struct buffer_head tmp_bh;
1366 struct buffer_head *bh;
1367
1368 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1369 while (towrite > 0) {
1370 tocopy = sb->s_blocksize - offset < towrite ?
1371 sb->s_blocksize - offset : towrite;
1372
1373 tmp_bh.b_state = 0;
1374 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1375 if (err < 0)
1376 goto out;
1377 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1378 bh = sb_bread(sb, tmp_bh.b_blocknr);
1379 else
1380 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1381 if (!bh) {
1382 err = -EIO;
1383 goto out;
1384 }
1385 lock_buffer(bh);
1386 memcpy(bh->b_data+offset, data, tocopy);
1387 flush_dcache_page(bh->b_page);
1388 set_buffer_uptodate(bh);
1389 mark_buffer_dirty(bh);
1390 unlock_buffer(bh);
1391 brelse(bh);
1392 offset = 0;
1393 towrite -= tocopy;
1394 data += tocopy;
1395 blk++;
1396 }
1397 out:
1398 if (len == towrite) {
1399 mutex_unlock(&inode->i_mutex);
1400 return err;
1401 }
1402 if (inode->i_size < off+len-towrite)
1403 i_size_write(inode, off+len-towrite);
1404 inode->i_version++;
1405 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1406 mark_inode_dirty(inode);
1407 mutex_unlock(&inode->i_mutex);
1408 return len - towrite;
1409 }
1410
1411 #endif
1412
1413 static struct file_system_type ext2_fs_type = {
1414 .owner = THIS_MODULE,
1415 .name = "ext2",
1416 .get_sb = ext2_get_sb,
1417 .kill_sb = kill_block_super,
1418 .fs_flags = FS_REQUIRES_DEV,
1419 };
1420
1421 static int __init init_ext2_fs(void)
1422 {
1423 int err = init_ext2_xattr();
1424 if (err)
1425 return err;
1426 err = init_inodecache();
1427 if (err)
1428 goto out1;
1429 err = register_filesystem(&ext2_fs_type);
1430 if (err)
1431 goto out;
1432 return 0;
1433 out:
1434 destroy_inodecache();
1435 out1:
1436 exit_ext2_xattr();
1437 return err;
1438 }
1439
1440 static void __exit exit_ext2_fs(void)
1441 {
1442 unregister_filesystem(&ext2_fs_type);
1443 destroy_inodecache();
1444 exit_ext2_xattr();
1445 }
1446
1447 module_init(init_ext2_fs)
1448 module_exit(exit_ext2_fs)
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