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x86: convert cpuinfo_x86 array to a per_cpu array
[wrt350n-kernel.git] / fs / ext2 / super.c
blob77bd5f9262f94c4e2da4a012c5f89b50af357dd1
1 /*
2 * linux/fs/ext2/super.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/inode.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Big-endian to little-endian byte-swapping/bitmaps by
16 * David S. Miller (davem@caip.rutgers.edu), 1995
17 */
18
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/slab.h>
23 #include <linux/init.h>
24 #include <linux/blkdev.h>
25 #include <linux/parser.h>
26 #include <linux/random.h>
27 #include <linux/buffer_head.h>
28 #include <linux/exportfs.h>
29 #include <linux/smp_lock.h>
30 #include <linux/vfs.h>
31 #include <linux/seq_file.h>
32 #include <linux/mount.h>
33 #include <linux/log2.h>
34 #include <asm/uaccess.h>
35 #include "ext2.h"
36 #include "xattr.h"
37 #include "acl.h"
38 #include "xip.h"
39
40 static void ext2_sync_super(struct super_block *sb,
41 struct ext2_super_block *es);
42 static int ext2_remount (struct super_block * sb, int * flags, char * data);
43 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
44
45 void ext2_error (struct super_block * sb, const char * function,
46 const char * fmt, ...)
47 {
48 va_list args;
49 struct ext2_sb_info *sbi = EXT2_SB(sb);
50 struct ext2_super_block *es = sbi->s_es;
51
52 if (!(sb->s_flags & MS_RDONLY)) {
53 sbi->s_mount_state |= EXT2_ERROR_FS;
54 es->s_state =
55 cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
56 ext2_sync_super(sb, es);
57 }
58
59 va_start(args, fmt);
60 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
61 vprintk(fmt, args);
62 printk("\n");
63 va_end(args);
64
65 if (test_opt(sb, ERRORS_PANIC))
66 panic("EXT2-fs panic from previous error\n");
67 if (test_opt(sb, ERRORS_RO)) {
68 printk("Remounting filesystem read-only\n");
69 sb->s_flags |= MS_RDONLY;
70 }
71 }
72
73 void ext2_warning (struct super_block * sb, const char * function,
74 const char * fmt, ...)
75 {
76 va_list args;
77
78 va_start(args, fmt);
79 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
80 sb->s_id, function);
81 vprintk(fmt, args);
82 printk("\n");
83 va_end(args);
84 }
85
86 void ext2_update_dynamic_rev(struct super_block *sb)
87 {
88 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
89
90 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
91 return;
92
93 ext2_warning(sb, __FUNCTION__,
94 "updating to rev %d because of new feature flag, "
95 "running e2fsck is recommended",
96 EXT2_DYNAMIC_REV);
97
98 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
99 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
100 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
101 /* leave es->s_feature_*compat flags alone */
102 /* es->s_uuid will be set by e2fsck if empty */
103
104 /*
105 * The rest of the superblock fields should be zero, and if not it
106 * means they are likely already in use, so leave them alone. We
107 * can leave it up to e2fsck to clean up any inconsistencies there.
108 */
109 }
110
111 static void ext2_put_super (struct super_block * sb)
112 {
113 int db_count;
114 int i;
115 struct ext2_sb_info *sbi = EXT2_SB(sb);
116
117 ext2_xattr_put_super(sb);
118 if (!(sb->s_flags & MS_RDONLY)) {
119 struct ext2_super_block *es = sbi->s_es;
120
121 es->s_state = cpu_to_le16(sbi->s_mount_state);
122 ext2_sync_super(sb, es);
123 }
124 db_count = sbi->s_gdb_count;
125 for (i = 0; i < db_count; i++)
126 if (sbi->s_group_desc[i])
127 brelse (sbi->s_group_desc[i]);
128 kfree(sbi->s_group_desc);
129 kfree(sbi->s_debts);
130 percpu_counter_destroy(&sbi->s_freeblocks_counter);
131 percpu_counter_destroy(&sbi->s_freeinodes_counter);
132 percpu_counter_destroy(&sbi->s_dirs_counter);
133 brelse (sbi->s_sbh);
134 sb->s_fs_info = NULL;
135 kfree(sbi);
136
137 return;
138 }
139
140 static struct kmem_cache * ext2_inode_cachep;
141
142 static struct inode *ext2_alloc_inode(struct super_block *sb)
143 {
144 struct ext2_inode_info *ei;
145 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
146 if (!ei)
147 return NULL;
148 #ifdef CONFIG_EXT2_FS_POSIX_ACL
149 ei->i_acl = EXT2_ACL_NOT_CACHED;
150 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
151 #endif
152 ei->i_block_alloc_info = NULL;
153 ei->vfs_inode.i_version = 1;
154 return &ei->vfs_inode;
155 }
156
157 static void ext2_destroy_inode(struct inode *inode)
158 {
159 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
160 }
161
162 static void init_once(struct kmem_cache * cachep, void *foo)
163 {
164 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
165
166 rwlock_init(&ei->i_meta_lock);
167 #ifdef CONFIG_EXT2_FS_XATTR
168 init_rwsem(&ei->xattr_sem);
169 #endif
170 mutex_init(&ei->truncate_mutex);
171 inode_init_once(&ei->vfs_inode);
172 }
173
174 static int init_inodecache(void)
175 {
176 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
177 sizeof(struct ext2_inode_info),
178 0, (SLAB_RECLAIM_ACCOUNT|
179 SLAB_MEM_SPREAD),
180 init_once);
181 if (ext2_inode_cachep == NULL)
182 return -ENOMEM;
183 return 0;
184 }
185
186 static void destroy_inodecache(void)
187 {
188 kmem_cache_destroy(ext2_inode_cachep);
189 }
190
191 static void ext2_clear_inode(struct inode *inode)
192 {
193 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
194 #ifdef CONFIG_EXT2_FS_POSIX_ACL
195 struct ext2_inode_info *ei = EXT2_I(inode);
196
197 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
198 posix_acl_release(ei->i_acl);
199 ei->i_acl = EXT2_ACL_NOT_CACHED;
200 }
201 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
202 posix_acl_release(ei->i_default_acl);
203 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
204 }
205 #endif
206 ext2_discard_reservation(inode);
207 EXT2_I(inode)->i_block_alloc_info = NULL;
208 if (unlikely(rsv))
209 kfree(rsv);
210 }
211
212 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
213 {
214 struct super_block *sb = vfs->mnt_sb;
215 struct ext2_sb_info *sbi = EXT2_SB(sb);
216 struct ext2_super_block *es = sbi->s_es;
217 unsigned long def_mount_opts;
218
219 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
220
221 if (sbi->s_sb_block != 1)
222 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
223 if (test_opt(sb, MINIX_DF))
224 seq_puts(seq, ",minixdf");
225 if (test_opt(sb, GRPID))
226 seq_puts(seq, ",grpid");
227 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
228 seq_puts(seq, ",nogrpid");
229 if (sbi->s_resuid != EXT2_DEF_RESUID ||
230 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
231 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
232 }
233 if (sbi->s_resgid != EXT2_DEF_RESGID ||
234 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
235 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
236 }
237 if (test_opt(sb, ERRORS_CONT)) {
238 int def_errors = le16_to_cpu(es->s_errors);
239
240 if (def_errors == EXT2_ERRORS_PANIC ||
241 def_errors == EXT2_ERRORS_RO) {
242 seq_puts(seq, ",errors=continue");
243 }
244 }
245 if (test_opt(sb, ERRORS_RO))
246 seq_puts(seq, ",errors=remount-ro");
247 if (test_opt(sb, ERRORS_PANIC))
248 seq_puts(seq, ",errors=panic");
249 if (test_opt(sb, NO_UID32))
250 seq_puts(seq, ",nouid32");
251 if (test_opt(sb, DEBUG))
252 seq_puts(seq, ",debug");
253 if (test_opt(sb, OLDALLOC))
254 seq_puts(seq, ",oldalloc");
255
256 #ifdef CONFIG_EXT2_FS_XATTR
257 if (test_opt(sb, XATTR_USER))
258 seq_puts(seq, ",user_xattr");
259 if (!test_opt(sb, XATTR_USER) &&
260 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
261 seq_puts(seq, ",nouser_xattr");
262 }
263 #endif
264
265 #ifdef CONFIG_EXT2_FS_POSIX_ACL
266 if (test_opt(sb, POSIX_ACL))
267 seq_puts(seq, ",acl");
268 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
269 seq_puts(seq, ",noacl");
270 #endif
271
272 if (test_opt(sb, NOBH))
273 seq_puts(seq, ",nobh");
274
275 #if defined(CONFIG_QUOTA)
276 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
277 seq_puts(seq, ",usrquota");
278
279 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
280 seq_puts(seq, ",grpquota");
281 #endif
282
283 #if defined(CONFIG_EXT2_FS_XIP)
284 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
285 seq_puts(seq, ",xip");
286 #endif
287
288 return 0;
289 }
290
291 #ifdef CONFIG_QUOTA
292 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
293 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
294 #endif
295
296 static const struct super_operations ext2_sops = {
297 .alloc_inode = ext2_alloc_inode,
298 .destroy_inode = ext2_destroy_inode,
299 .read_inode = ext2_read_inode,
300 .write_inode = ext2_write_inode,
301 .delete_inode = ext2_delete_inode,
302 .put_super = ext2_put_super,
303 .write_super = ext2_write_super,
304 .statfs = ext2_statfs,
305 .remount_fs = ext2_remount,
306 .clear_inode = ext2_clear_inode,
307 .show_options = ext2_show_options,
308 #ifdef CONFIG_QUOTA
309 .quota_read = ext2_quota_read,
310 .quota_write = ext2_quota_write,
311 #endif
312 };
313
314 static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp)
315 {
316 __u32 *objp = vobjp;
317 unsigned long ino = objp[0];
318 __u32 generation = objp[1];
319 struct inode *inode;
320 struct dentry *result;
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 = iget(sb, ino);
333 if (inode == NULL)
334 return ERR_PTR(-ENOMEM);
335 if (is_bad_inode(inode) ||
336 (generation && inode->i_generation != generation)) {
337 /* we didn't find the right inode.. */
338 iput(inode);
339 return ERR_PTR(-ESTALE);
340 }
341 /* now to find a dentry.
342 * If possible, get a well-connected one
343 */
344 result = d_alloc_anon(inode);
345 if (!result) {
346 iput(inode);
347 return ERR_PTR(-ENOMEM);
348 }
349 return result;
350 }
351
352 /* Yes, most of these are left as NULL!!
353 * A NULL value implies the default, which works with ext2-like file
354 * systems, but can be improved upon.
355 * Currently only get_parent is required.
356 */
357 static struct export_operations ext2_export_ops = {
358 .get_parent = ext2_get_parent,
359 .get_dentry = ext2_get_dentry,
360 };
361
362 static unsigned long get_sb_block(void **data)
363 {
364 unsigned long sb_block;
365 char *options = (char *) *data;
366
367 if (!options || strncmp(options, "sb=", 3) != 0)
368 return 1; /* Default location */
369 options += 3;
370 sb_block = simple_strtoul(options, &options, 0);
371 if (*options && *options != ',') {
372 printk("EXT2-fs: Invalid sb specification: %s\n",
373 (char *) *data);
374 return 1;
375 }
376 if (*options == ',')
377 options++;
378 *data = (void *) options;
379 return sb_block;
380 }
381
382 enum {
383 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
384 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
385 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
386 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
387 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
388 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
389 };
390
391 static match_table_t tokens = {
392 {Opt_bsd_df, "bsddf"},
393 {Opt_minix_df, "minixdf"},
394 {Opt_grpid, "grpid"},
395 {Opt_grpid, "bsdgroups"},
396 {Opt_nogrpid, "nogrpid"},
397 {Opt_nogrpid, "sysvgroups"},
398 {Opt_resgid, "resgid=%u"},
399 {Opt_resuid, "resuid=%u"},
400 {Opt_sb, "sb=%u"},
401 {Opt_err_cont, "errors=continue"},
402 {Opt_err_panic, "errors=panic"},
403 {Opt_err_ro, "errors=remount-ro"},
404 {Opt_nouid32, "nouid32"},
405 {Opt_nocheck, "check=none"},
406 {Opt_nocheck, "nocheck"},
407 {Opt_debug, "debug"},
408 {Opt_oldalloc, "oldalloc"},
409 {Opt_orlov, "orlov"},
410 {Opt_nobh, "nobh"},
411 {Opt_user_xattr, "user_xattr"},
412 {Opt_nouser_xattr, "nouser_xattr"},
413 {Opt_acl, "acl"},
414 {Opt_noacl, "noacl"},
415 {Opt_xip, "xip"},
416 {Opt_grpquota, "grpquota"},
417 {Opt_ignore, "noquota"},
418 {Opt_quota, "quota"},
419 {Opt_usrquota, "usrquota"},
420 {Opt_reservation, "reservation"},
421 {Opt_noreservation, "noreservation"},
422 {Opt_err, NULL}
423 };
424
425 static int parse_options (char * options,
426 struct ext2_sb_info *sbi)
427 {
428 char * p;
429 substring_t args[MAX_OPT_ARGS];
430 int option;
431
432 if (!options)
433 return 1;
434
435 while ((p = strsep (&options, ",")) != NULL) {
436 int token;
437 if (!*p)
438 continue;
439
440 token = match_token(p, tokens, args);
441 switch (token) {
442 case Opt_bsd_df:
443 clear_opt (sbi->s_mount_opt, MINIX_DF);
444 break;
445 case Opt_minix_df:
446 set_opt (sbi->s_mount_opt, MINIX_DF);
447 break;
448 case Opt_grpid:
449 set_opt (sbi->s_mount_opt, GRPID);
450 break;
451 case Opt_nogrpid:
452 clear_opt (sbi->s_mount_opt, GRPID);
453 break;
454 case Opt_resuid:
455 if (match_int(&args[0], &option))
456 return 0;
457 sbi->s_resuid = option;
458 break;
459 case Opt_resgid:
460 if (match_int(&args[0], &option))
461 return 0;
462 sbi->s_resgid = option;
463 break;
464 case Opt_sb:
465 /* handled by get_sb_block() instead of here */
466 /* *sb_block = match_int(&args[0]); */
467 break;
468 case Opt_err_panic:
469 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
470 clear_opt (sbi->s_mount_opt, ERRORS_RO);
471 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
472 break;
473 case Opt_err_ro:
474 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
475 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
476 set_opt (sbi->s_mount_opt, ERRORS_RO);
477 break;
478 case Opt_err_cont:
479 clear_opt (sbi->s_mount_opt, ERRORS_RO);
480 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
481 set_opt (sbi->s_mount_opt, ERRORS_CONT);
482 break;
483 case Opt_nouid32:
484 set_opt (sbi->s_mount_opt, NO_UID32);
485 break;
486 case Opt_nocheck:
487 clear_opt (sbi->s_mount_opt, CHECK);
488 break;
489 case Opt_debug:
490 set_opt (sbi->s_mount_opt, DEBUG);
491 break;
492 case Opt_oldalloc:
493 set_opt (sbi->s_mount_opt, OLDALLOC);
494 break;
495 case Opt_orlov:
496 clear_opt (sbi->s_mount_opt, OLDALLOC);
497 break;
498 case Opt_nobh:
499 set_opt (sbi->s_mount_opt, NOBH);
500 break;
501 #ifdef CONFIG_EXT2_FS_XATTR
502 case Opt_user_xattr:
503 set_opt (sbi->s_mount_opt, XATTR_USER);
504 break;
505 case Opt_nouser_xattr:
506 clear_opt (sbi->s_mount_opt, XATTR_USER);
507 break;
508 #else
509 case Opt_user_xattr:
510 case Opt_nouser_xattr:
511 printk("EXT2 (no)user_xattr options not supported\n");
512 break;
513 #endif
514 #ifdef CONFIG_EXT2_FS_POSIX_ACL
515 case Opt_acl:
516 set_opt(sbi->s_mount_opt, POSIX_ACL);
517 break;
518 case Opt_noacl:
519 clear_opt(sbi->s_mount_opt, POSIX_ACL);
520 break;
521 #else
522 case Opt_acl:
523 case Opt_noacl:
524 printk("EXT2 (no)acl options not supported\n");
525 break;
526 #endif
527 case Opt_xip:
528 #ifdef CONFIG_EXT2_FS_XIP
529 set_opt (sbi->s_mount_opt, XIP);
530 #else
531 printk("EXT2 xip option not supported\n");
532 #endif
533 break;
534
535 #if defined(CONFIG_QUOTA)
536 case Opt_quota:
537 case Opt_usrquota:
538 set_opt(sbi->s_mount_opt, USRQUOTA);
539 break;
540
541 case Opt_grpquota:
542 set_opt(sbi->s_mount_opt, GRPQUOTA);
543 break;
544 #else
545 case Opt_quota:
546 case Opt_usrquota:
547 case Opt_grpquota:
548 printk(KERN_ERR
549 "EXT2-fs: quota operations not supported.\n");
550
551 break;
552 #endif
553
554 case Opt_reservation:
555 set_opt(sbi->s_mount_opt, RESERVATION);
556 printk("reservations ON\n");
557 break;
558 case Opt_noreservation:
559 clear_opt(sbi->s_mount_opt, RESERVATION);
560 printk("reservations OFF\n");
561 break;
562 case Opt_ignore:
563 break;
564 default:
565 return 0;
566 }
567 }
568 return 1;
569 }
570
571 static int ext2_setup_super (struct super_block * sb,
572 struct ext2_super_block * es,
573 int read_only)
574 {
575 int res = 0;
576 struct ext2_sb_info *sbi = EXT2_SB(sb);
577
578 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
579 printk ("EXT2-fs warning: revision level too high, "
580 "forcing read-only mode\n");
581 res = MS_RDONLY;
582 }
583 if (read_only)
584 return res;
585 if (!(sbi->s_mount_state & EXT2_VALID_FS))
586 printk ("EXT2-fs warning: mounting unchecked fs, "
587 "running e2fsck is recommended\n");
588 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
589 printk ("EXT2-fs warning: mounting fs with errors, "
590 "running e2fsck is recommended\n");
591 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
592 le16_to_cpu(es->s_mnt_count) >=
593 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
594 printk ("EXT2-fs warning: maximal mount count reached, "
595 "running e2fsck is recommended\n");
596 else if (le32_to_cpu(es->s_checkinterval) &&
597 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
598 printk ("EXT2-fs warning: checktime reached, "
599 "running e2fsck is recommended\n");
600 if (!le16_to_cpu(es->s_max_mnt_count))
601 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
602 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
603 ext2_write_super(sb);
604 if (test_opt (sb, DEBUG))
605 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
606 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
607 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
608 sbi->s_frag_size,
609 sbi->s_groups_count,
610 EXT2_BLOCKS_PER_GROUP(sb),
611 EXT2_INODES_PER_GROUP(sb),
612 sbi->s_mount_opt);
613 return res;
614 }
615
616 static int ext2_check_descriptors (struct super_block * sb)
617 {
618 int i;
619 int desc_block = 0;
620 struct ext2_sb_info *sbi = EXT2_SB(sb);
621 unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
622 unsigned long last_block;
623 struct ext2_group_desc * gdp = NULL;
624
625 ext2_debug ("Checking group descriptors");
626
627 for (i = 0; i < sbi->s_groups_count; i++)
628 {
629 if (i == sbi->s_groups_count - 1)
630 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
631 else
632 last_block = first_block +
633 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
634
635 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
636 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
637 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
638 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
639 {
640 ext2_error (sb, "ext2_check_descriptors",
641 "Block bitmap for group %d"
642 " not in group (block %lu)!",
643 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
644 return 0;
645 }
646 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
647 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
648 {
649 ext2_error (sb, "ext2_check_descriptors",
650 "Inode bitmap for group %d"
651 " not in group (block %lu)!",
652 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
653 return 0;
654 }
655 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
656 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
657 last_block)
658 {
659 ext2_error (sb, "ext2_check_descriptors",
660 "Inode table for group %d"
661 " not in group (block %lu)!",
662 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
663 return 0;
664 }
665 first_block += EXT2_BLOCKS_PER_GROUP(sb);
666 gdp++;
667 }
668 return 1;
669 }
670
671 /*
672 * Maximal file size. There is a direct, and {,double-,triple-}indirect
673 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
674 * We need to be 1 filesystem block less than the 2^32 sector limit.
675 */
676 static loff_t ext2_max_size(int bits)
677 {
678 loff_t res = EXT2_NDIR_BLOCKS;
679 /* This constant is calculated to be the largest file size for a
680 * dense, 4k-blocksize file such that the total number of
681 * sectors in the file, including data and all indirect blocks,
682 * does not exceed 2^32. */
683 const loff_t upper_limit = 0x1ff7fffd000LL;
684
685 res += 1LL << (bits-2);
686 res += 1LL << (2*(bits-2));
687 res += 1LL << (3*(bits-2));
688 res <<= bits;
689 if (res > upper_limit)
690 res = upper_limit;
691 return res;
692 }
693
694 static unsigned long descriptor_loc(struct super_block *sb,
695 unsigned long logic_sb_block,
696 int nr)
697 {
698 struct ext2_sb_info *sbi = EXT2_SB(sb);
699 unsigned long bg, first_data_block, first_meta_bg;
700 int has_super = 0;
701
702 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
703 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
704
705 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
706 nr < first_meta_bg)
707 return (logic_sb_block + nr + 1);
708 bg = sbi->s_desc_per_block * nr;
709 if (ext2_bg_has_super(sb, bg))
710 has_super = 1;
711 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
712 }
713
714 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
715 {
716 struct buffer_head * bh;
717 struct ext2_sb_info * sbi;
718 struct ext2_super_block * es;
719 struct inode *root;
720 unsigned long block;
721 unsigned long sb_block = get_sb_block(&data);
722 unsigned long logic_sb_block;
723 unsigned long offset = 0;
724 unsigned long def_mount_opts;
725 int blocksize = BLOCK_SIZE;
726 int db_count;
727 int i, j;
728 __le32 features;
729 int err;
730
731 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
732 if (!sbi)
733 return -ENOMEM;
734 sb->s_fs_info = sbi;
735 sbi->s_sb_block = sb_block;
736
737 /*
738 * See what the current blocksize for the device is, and
739 * use that as the blocksize. Otherwise (or if the blocksize
740 * is smaller than the default) use the default.
741 * This is important for devices that have a hardware
742 * sectorsize that is larger than the default.
743 */
744 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
745 if (!blocksize) {
746 printk ("EXT2-fs: unable to set blocksize\n");
747 goto failed_sbi;
748 }
749
750 /*
751 * If the superblock doesn't start on a hardware sector boundary,
752 * calculate the offset.
753 */
754 if (blocksize != BLOCK_SIZE) {
755 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
756 offset = (sb_block*BLOCK_SIZE) % blocksize;
757 } else {
758 logic_sb_block = sb_block;
759 }
760
761 if (!(bh = sb_bread(sb, logic_sb_block))) {
762 printk ("EXT2-fs: unable to read superblock\n");
763 goto failed_sbi;
764 }
765 /*
766 * Note: s_es must be initialized as soon as possible because
767 * some ext2 macro-instructions depend on its value
768 */
769 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
770 sbi->s_es = es;
771 sb->s_magic = le16_to_cpu(es->s_magic);
772
773 if (sb->s_magic != EXT2_SUPER_MAGIC)
774 goto cantfind_ext2;
775
776 /* Set defaults before we parse the mount options */
777 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
778 if (def_mount_opts & EXT2_DEFM_DEBUG)
779 set_opt(sbi->s_mount_opt, DEBUG);
780 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
781 set_opt(sbi->s_mount_opt, GRPID);
782 if (def_mount_opts & EXT2_DEFM_UID16)
783 set_opt(sbi->s_mount_opt, NO_UID32);
784 #ifdef CONFIG_EXT2_FS_XATTR
785 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
786 set_opt(sbi->s_mount_opt, XATTR_USER);
787 #endif
788 #ifdef CONFIG_EXT2_FS_POSIX_ACL
789 if (def_mount_opts & EXT2_DEFM_ACL)
790 set_opt(sbi->s_mount_opt, POSIX_ACL);
791 #endif
792
793 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
794 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
795 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
796 set_opt(sbi->s_mount_opt, ERRORS_RO);
797 else
798 set_opt(sbi->s_mount_opt, ERRORS_CONT);
799
800 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
801 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
802
803 set_opt(sbi->s_mount_opt, RESERVATION);
804
805 if (!parse_options ((char *) data, sbi))
806 goto failed_mount;
807
808 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
809 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
810 MS_POSIXACL : 0);
811
812 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
813 EXT2_MOUNT_XIP if not */
814
815 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
816 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
817 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
818 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
819 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
820 "running e2fsck is recommended\n");
821 /*
822 * Check feature flags regardless of the revision level, since we
823 * previously didn't change the revision level when setting the flags,
824 * so there is a chance incompat flags are set on a rev 0 filesystem.
825 */
826 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
827 if (features) {
828 printk("EXT2-fs: %s: couldn't mount because of "
829 "unsupported optional features (%x).\n",
830 sb->s_id, le32_to_cpu(features));
831 goto failed_mount;
832 }
833 if (!(sb->s_flags & MS_RDONLY) &&
834 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
835 printk("EXT2-fs: %s: couldn't mount RDWR because of "
836 "unsupported optional features (%x).\n",
837 sb->s_id, le32_to_cpu(features));
838 goto failed_mount;
839 }
840
841 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
842
843 if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) ||
844 (sb->s_blocksize != blocksize))) {
845 if (!silent)
846 printk("XIP: Unsupported blocksize\n");
847 goto failed_mount;
848 }
849
850 /* If the blocksize doesn't match, re-read the thing.. */
851 if (sb->s_blocksize != blocksize) {
852 brelse(bh);
853
854 if (!sb_set_blocksize(sb, blocksize)) {
855 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
856 goto failed_sbi;
857 }
858
859 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
860 offset = (sb_block*BLOCK_SIZE) % blocksize;
861 bh = sb_bread(sb, logic_sb_block);
862 if(!bh) {
863 printk("EXT2-fs: Couldn't read superblock on "
864 "2nd try.\n");
865 goto failed_sbi;
866 }
867 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
868 sbi->s_es = es;
869 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
870 printk ("EXT2-fs: Magic mismatch, very weird !\n");
871 goto failed_mount;
872 }
873 }
874
875 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
876
877 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
878 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
879 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
880 } else {
881 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
882 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
883 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
884 !is_power_of_2(sbi->s_inode_size) ||
885 (sbi->s_inode_size > blocksize)) {
886 printk ("EXT2-fs: unsupported inode size: %d\n",
887 sbi->s_inode_size);
888 goto failed_mount;
889 }
890 }
891
892 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
893 le32_to_cpu(es->s_log_frag_size);
894 if (sbi->s_frag_size == 0)
895 goto cantfind_ext2;
896 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
897
898 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
899 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
900 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
901
902 if (EXT2_INODE_SIZE(sb) == 0)
903 goto cantfind_ext2;
904 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
905 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
906 goto cantfind_ext2;
907 sbi->s_itb_per_group = sbi->s_inodes_per_group /
908 sbi->s_inodes_per_block;
909 sbi->s_desc_per_block = sb->s_blocksize /
910 sizeof (struct ext2_group_desc);
911 sbi->s_sbh = bh;
912 sbi->s_mount_state = le16_to_cpu(es->s_state);
913 sbi->s_addr_per_block_bits =
914 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
915 sbi->s_desc_per_block_bits =
916 ilog2 (EXT2_DESC_PER_BLOCK(sb));
917
918 if (sb->s_magic != EXT2_SUPER_MAGIC)
919 goto cantfind_ext2;
920
921 if (sb->s_blocksize != bh->b_size) {
922 if (!silent)
923 printk ("VFS: Unsupported blocksize on dev "
924 "%s.\n", sb->s_id);
925 goto failed_mount;
926 }
927
928 if (sb->s_blocksize != sbi->s_frag_size) {
929 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
930 sbi->s_frag_size, sb->s_blocksize);
931 goto failed_mount;
932 }
933
934 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
935 printk ("EXT2-fs: #blocks per group too big: %lu\n",
936 sbi->s_blocks_per_group);
937 goto failed_mount;
938 }
939 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
940 printk ("EXT2-fs: #fragments per group too big: %lu\n",
941 sbi->s_frags_per_group);
942 goto failed_mount;
943 }
944 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
945 printk ("EXT2-fs: #inodes per group too big: %lu\n",
946 sbi->s_inodes_per_group);
947 goto failed_mount;
948 }
949
950 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
951 goto cantfind_ext2;
952 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
953 le32_to_cpu(es->s_first_data_block) - 1)
954 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
955 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
956 EXT2_DESC_PER_BLOCK(sb);
957 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
958 if (sbi->s_group_desc == NULL) {
959 printk ("EXT2-fs: not enough memory\n");
960 goto failed_mount;
961 }
962 bgl_lock_init(&sbi->s_blockgroup_lock);
963 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
964 if (!sbi->s_debts) {
965 printk ("EXT2-fs: not enough memory\n");
966 goto failed_mount_group_desc;
967 }
968 for (i = 0; i < db_count; i++) {
969 block = descriptor_loc(sb, logic_sb_block, i);
970 sbi->s_group_desc[i] = sb_bread(sb, block);
971 if (!sbi->s_group_desc[i]) {
972 for (j = 0; j < i; j++)
973 brelse (sbi->s_group_desc[j]);
974 printk ("EXT2-fs: unable to read group descriptors\n");
975 goto failed_mount_group_desc;
976 }
977 }
978 if (!ext2_check_descriptors (sb)) {
979 printk ("EXT2-fs: group descriptors corrupted!\n");
980 goto failed_mount2;
981 }
982 sbi->s_gdb_count = db_count;
983 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
984 spin_lock_init(&sbi->s_next_gen_lock);
985
986 /* per fileystem reservation list head & lock */
987 spin_lock_init(&sbi->s_rsv_window_lock);
988 sbi->s_rsv_window_root = RB_ROOT;
989 /*
990 * Add a single, static dummy reservation to the start of the
991 * reservation window list --- it gives us a placeholder for
992 * append-at-start-of-list which makes the allocation logic
993 * _much_ simpler.
994 */
995 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
996 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
997 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
998 sbi->s_rsv_window_head.rsv_goal_size = 0;
999 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1000
1001 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1002 ext2_count_free_blocks(sb));
1003 if (!err) {
1004 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1005 ext2_count_free_inodes(sb));
1006 }
1007 if (!err) {
1008 err = percpu_counter_init(&sbi->s_dirs_counter,
1009 ext2_count_dirs(sb));
1010 }
1011 if (err) {
1012 printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1013 goto failed_mount3;
1014 }
1015 /*
1016 * set up enough so that it can read an inode
1017 */
1018 sb->s_op = &ext2_sops;
1019 sb->s_export_op = &ext2_export_ops;
1020 sb->s_xattr = ext2_xattr_handlers;
1021 root = iget(sb, EXT2_ROOT_INO);
1022 sb->s_root = d_alloc_root(root);
1023 if (!sb->s_root) {
1024 iput(root);
1025 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1026 goto failed_mount3;
1027 }
1028 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1029 dput(sb->s_root);
1030 sb->s_root = NULL;
1031 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1032 goto failed_mount3;
1033 }
1034 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1035 ext2_warning(sb, __FUNCTION__,
1036 "mounting ext3 filesystem as ext2");
1037 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1038 return 0;
1039
1040 cantfind_ext2:
1041 if (!silent)
1042 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1043 sb->s_id);
1044 goto failed_mount;
1045 failed_mount3:
1046 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1047 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1048 percpu_counter_destroy(&sbi->s_dirs_counter);
1049 failed_mount2:
1050 for (i = 0; i < db_count; i++)
1051 brelse(sbi->s_group_desc[i]);
1052 failed_mount_group_desc:
1053 kfree(sbi->s_group_desc);
1054 kfree(sbi->s_debts);
1055 failed_mount:
1056 brelse(bh);
1057 failed_sbi:
1058 sb->s_fs_info = NULL;
1059 kfree(sbi);
1060 return -EINVAL;
1061 }
1062
1063 static void ext2_commit_super (struct super_block * sb,
1064 struct ext2_super_block * es)
1065 {
1066 es->s_wtime = cpu_to_le32(get_seconds());
1067 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1068 sb->s_dirt = 0;
1069 }
1070
1071 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1072 {
1073 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1074 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1075 es->s_wtime = cpu_to_le32(get_seconds());
1076 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1077 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1078 sb->s_dirt = 0;
1079 }
1080
1081 /*
1082 * In the second extended file system, it is not necessary to
1083 * write the super block since we use a mapping of the
1084 * disk super block in a buffer.
1085 *
1086 * However, this function is still used to set the fs valid
1087 * flags to 0. We need to set this flag to 0 since the fs
1088 * may have been checked while mounted and e2fsck may have
1089 * set s_state to EXT2_VALID_FS after some corrections.
1090 */
1091
1092 void ext2_write_super (struct super_block * sb)
1093 {
1094 struct ext2_super_block * es;
1095 lock_kernel();
1096 if (!(sb->s_flags & MS_RDONLY)) {
1097 es = EXT2_SB(sb)->s_es;
1098
1099 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
1100 ext2_debug ("setting valid to 0\n");
1101 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
1102 ~EXT2_VALID_FS);
1103 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1104 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1105 es->s_mtime = cpu_to_le32(get_seconds());
1106 ext2_sync_super(sb, es);
1107 } else
1108 ext2_commit_super (sb, es);
1109 }
1110 sb->s_dirt = 0;
1111 unlock_kernel();
1112 }
1113
1114 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1115 {
1116 struct ext2_sb_info * sbi = EXT2_SB(sb);
1117 struct ext2_super_block * es;
1118 unsigned long old_mount_opt = sbi->s_mount_opt;
1119 struct ext2_mount_options old_opts;
1120 unsigned long old_sb_flags;
1121 int err;
1122
1123 /* Store the old options */
1124 old_sb_flags = sb->s_flags;
1125 old_opts.s_mount_opt = sbi->s_mount_opt;
1126 old_opts.s_resuid = sbi->s_resuid;
1127 old_opts.s_resgid = sbi->s_resgid;
1128
1129 /*
1130 * Allow the "check" option to be passed as a remount option.
1131 */
1132 if (!parse_options (data, sbi)) {
1133 err = -EINVAL;
1134 goto restore_opts;
1135 }
1136
1137 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1138 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1139
1140 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1141 EXT2_MOUNT_XIP if not */
1142
1143 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1144 printk("XIP: Unsupported blocksize\n");
1145 err = -EINVAL;
1146 goto restore_opts;
1147 }
1148
1149 es = sbi->s_es;
1150 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1151 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1152 invalidate_inodes(sb))
1153 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
1154 "xip remain in cache (no functional problem)");
1155 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1156 return 0;
1157 if (*flags & MS_RDONLY) {
1158 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1159 !(sbi->s_mount_state & EXT2_VALID_FS))
1160 return 0;
1161 /*
1162 * OK, we are remounting a valid rw partition rdonly, so set
1163 * the rdonly flag and then mark the partition as valid again.
1164 */
1165 es->s_state = cpu_to_le16(sbi->s_mount_state);
1166 es->s_mtime = cpu_to_le32(get_seconds());
1167 } else {
1168 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1169 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1170 if (ret) {
1171 printk("EXT2-fs: %s: couldn't remount RDWR because of "
1172 "unsupported optional features (%x).\n",
1173 sb->s_id, le32_to_cpu(ret));
1174 err = -EROFS;
1175 goto restore_opts;
1176 }
1177 /*
1178 * Mounting a RDONLY partition read-write, so reread and
1179 * store the current valid flag. (It may have been changed
1180 * by e2fsck since we originally mounted the partition.)
1181 */
1182 sbi->s_mount_state = le16_to_cpu(es->s_state);
1183 if (!ext2_setup_super (sb, es, 0))
1184 sb->s_flags &= ~MS_RDONLY;
1185 }
1186 ext2_sync_super(sb, es);
1187 return 0;
1188 restore_opts:
1189 sbi->s_mount_opt = old_opts.s_mount_opt;
1190 sbi->s_resuid = old_opts.s_resuid;
1191 sbi->s_resgid = old_opts.s_resgid;
1192 sb->s_flags = old_sb_flags;
1193 return err;
1194 }
1195
1196 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1197 {
1198 struct super_block *sb = dentry->d_sb;
1199 struct ext2_sb_info *sbi = EXT2_SB(sb);
1200 struct ext2_super_block *es = sbi->s_es;
1201 u64 fsid;
1202
1203 if (test_opt (sb, MINIX_DF))
1204 sbi->s_overhead_last = 0;
1205 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1206 unsigned long i, overhead = 0;
1207 smp_rmb();
1208
1209 /*
1210 * Compute the overhead (FS structures). This is constant
1211 * for a given filesystem unless the number of block groups
1212 * changes so we cache the previous value until it does.
1213 */
1214
1215 /*
1216 * All of the blocks before first_data_block are
1217 * overhead
1218 */
1219 overhead = le32_to_cpu(es->s_first_data_block);
1220
1221 /*
1222 * Add the overhead attributed to the superblock and
1223 * block group descriptors. If the sparse superblocks
1224 * feature is turned on, then not all groups have this.
1225 */
1226 for (i = 0; i < sbi->s_groups_count; i++)
1227 overhead += ext2_bg_has_super(sb, i) +
1228 ext2_bg_num_gdb(sb, i);
1229
1230 /*
1231 * Every block group has an inode bitmap, a block
1232 * bitmap, and an inode table.
1233 */
1234 overhead += (sbi->s_groups_count *
1235 (2 + sbi->s_itb_per_group));
1236 sbi->s_overhead_last = overhead;
1237 smp_wmb();
1238 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1239 }
1240
1241 buf->f_type = EXT2_SUPER_MAGIC;
1242 buf->f_bsize = sb->s_blocksize;
1243 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1244 buf->f_bfree = ext2_count_free_blocks(sb);
1245 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1246 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1247 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1248 buf->f_bavail = 0;
1249 buf->f_files = le32_to_cpu(es->s_inodes_count);
1250 buf->f_ffree = ext2_count_free_inodes(sb);
1251 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1252 buf->f_namelen = EXT2_NAME_LEN;
1253 fsid = le64_to_cpup((void *)es->s_uuid) ^
1254 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1255 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1256 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1257 return 0;
1258 }
1259
1260 static int ext2_get_sb(struct file_system_type *fs_type,
1261 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1262 {
1263 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1264 }
1265
1266 #ifdef CONFIG_QUOTA
1267
1268 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1269 * acquiring the locks... As quota files are never truncated and quota code
1270 * itself serializes the operations (and noone else should touch the files)
1271 * we don't have to be afraid of races */
1272 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1273 size_t len, loff_t off)
1274 {
1275 struct inode *inode = sb_dqopt(sb)->files[type];
1276 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1277 int err = 0;
1278 int offset = off & (sb->s_blocksize - 1);
1279 int tocopy;
1280 size_t toread;
1281 struct buffer_head tmp_bh;
1282 struct buffer_head *bh;
1283 loff_t i_size = i_size_read(inode);
1284
1285 if (off > i_size)
1286 return 0;
1287 if (off+len > i_size)
1288 len = i_size-off;
1289 toread = len;
1290 while (toread > 0) {
1291 tocopy = sb->s_blocksize - offset < toread ?
1292 sb->s_blocksize - offset : toread;
1293
1294 tmp_bh.b_state = 0;
1295 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1296 if (err < 0)
1297 return err;
1298 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1299 memset(data, 0, tocopy);
1300 else {
1301 bh = sb_bread(sb, tmp_bh.b_blocknr);
1302 if (!bh)
1303 return -EIO;
1304 memcpy(data, bh->b_data+offset, tocopy);
1305 brelse(bh);
1306 }
1307 offset = 0;
1308 toread -= tocopy;
1309 data += tocopy;
1310 blk++;
1311 }
1312 return len;
1313 }
1314
1315 /* Write to quotafile */
1316 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1317 const char *data, size_t len, loff_t off)
1318 {
1319 struct inode *inode = sb_dqopt(sb)->files[type];
1320 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1321 int err = 0;
1322 int offset = off & (sb->s_blocksize - 1);
1323 int tocopy;
1324 size_t towrite = len;
1325 struct buffer_head tmp_bh;
1326 struct buffer_head *bh;
1327
1328 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1329 while (towrite > 0) {
1330 tocopy = sb->s_blocksize - offset < towrite ?
1331 sb->s_blocksize - offset : towrite;
1332
1333 tmp_bh.b_state = 0;
1334 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1335 if (err < 0)
1336 goto out;
1337 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1338 bh = sb_bread(sb, tmp_bh.b_blocknr);
1339 else
1340 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1341 if (!bh) {
1342 err = -EIO;
1343 goto out;
1344 }
1345 lock_buffer(bh);
1346 memcpy(bh->b_data+offset, data, tocopy);
1347 flush_dcache_page(bh->b_page);
1348 set_buffer_uptodate(bh);
1349 mark_buffer_dirty(bh);
1350 unlock_buffer(bh);
1351 brelse(bh);
1352 offset = 0;
1353 towrite -= tocopy;
1354 data += tocopy;
1355 blk++;
1356 }
1357 out:
1358 if (len == towrite)
1359 return err;
1360 if (inode->i_size < off+len-towrite)
1361 i_size_write(inode, off+len-towrite);
1362 inode->i_version++;
1363 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1364 mark_inode_dirty(inode);
1365 mutex_unlock(&inode->i_mutex);
1366 return len - towrite;
1367 }
1368
1369 #endif
1370
1371 static struct file_system_type ext2_fs_type = {
1372 .owner = THIS_MODULE,
1373 .name = "ext2",
1374 .get_sb = ext2_get_sb,
1375 .kill_sb = kill_block_super,
1376 .fs_flags = FS_REQUIRES_DEV,
1377 };
1378
1379 static int __init init_ext2_fs(void)
1380 {
1381 int err = init_ext2_xattr();
1382 if (err)
1383 return err;
1384 err = init_inodecache();
1385 if (err)
1386 goto out1;
1387 err = register_filesystem(&ext2_fs_type);
1388 if (err)
1389 goto out;
1390 return 0;
1391 out:
1392 destroy_inodecache();
1393 out1:
1394 exit_ext2_xattr();
1395 return err;
1396 }
1397
1398 static void __exit exit_ext2_fs(void)
1399 {
1400 unregister_filesystem(&ext2_fs_type);
1401 destroy_inodecache();
1402 exit_ext2_xattr();
1403 }
1404
1405 module_init(init_ext2_fs)
1406 module_exit(exit_ext2_fs)
WRT350N Kernel Patches