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powerpc/mm: Add SAO Feature bit to the cputable
[linux-2.6/kvm.git] / fs / ext2 / super.c
blobef50cbc792db94668b9d7deecc22c50076511fe4
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 |= cpu_to_le16(EXT2_ERROR_FS);
55 ext2_sync_super(sb, es);
56 }
57
58 va_start(args, fmt);
59 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
60 vprintk(fmt, args);
61 printk("\n");
62 va_end(args);
63
64 if (test_opt(sb, ERRORS_PANIC))
65 panic("EXT2-fs panic from previous error\n");
66 if (test_opt(sb, ERRORS_RO)) {
67 printk("Remounting filesystem read-only\n");
68 sb->s_flags |= MS_RDONLY;
69 }
70 }
71
72 void ext2_warning (struct super_block * sb, const char * function,
73 const char * fmt, ...)
74 {
75 va_list args;
76
77 va_start(args, fmt);
78 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
79 sb->s_id, function);
80 vprintk(fmt, args);
81 printk("\n");
82 va_end(args);
83 }
84
85 void ext2_update_dynamic_rev(struct super_block *sb)
86 {
87 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
88
89 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
90 return;
91
92 ext2_warning(sb, __func__,
93 "updating to rev %d because of new feature flag, "
94 "running e2fsck is recommended",
95 EXT2_DYNAMIC_REV);
96
97 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
98 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
99 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
100 /* leave es->s_feature_*compat flags alone */
101 /* es->s_uuid will be set by e2fsck if empty */
102
103 /*
104 * The rest of the superblock fields should be zero, and if not it
105 * means they are likely already in use, so leave them alone. We
106 * can leave it up to e2fsck to clean up any inconsistencies there.
107 */
108 }
109
110 static void ext2_put_super (struct super_block * sb)
111 {
112 int db_count;
113 int i;
114 struct ext2_sb_info *sbi = EXT2_SB(sb);
115
116 ext2_xattr_put_super(sb);
117 if (!(sb->s_flags & MS_RDONLY)) {
118 struct ext2_super_block *es = sbi->s_es;
119
120 es->s_state = cpu_to_le16(sbi->s_mount_state);
121 ext2_sync_super(sb, es);
122 }
123 db_count = sbi->s_gdb_count;
124 for (i = 0; i < db_count; i++)
125 if (sbi->s_group_desc[i])
126 brelse (sbi->s_group_desc[i]);
127 kfree(sbi->s_group_desc);
128 kfree(sbi->s_debts);
129 percpu_counter_destroy(&sbi->s_freeblocks_counter);
130 percpu_counter_destroy(&sbi->s_freeinodes_counter);
131 percpu_counter_destroy(&sbi->s_dirs_counter);
132 brelse (sbi->s_sbh);
133 sb->s_fs_info = NULL;
134 kfree(sbi);
135
136 return;
137 }
138
139 static struct kmem_cache * ext2_inode_cachep;
140
141 static struct inode *ext2_alloc_inode(struct super_block *sb)
142 {
143 struct ext2_inode_info *ei;
144 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
145 if (!ei)
146 return NULL;
147 #ifdef CONFIG_EXT2_FS_POSIX_ACL
148 ei->i_acl = EXT2_ACL_NOT_CACHED;
149 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
150 #endif
151 ei->i_block_alloc_info = NULL;
152 ei->vfs_inode.i_version = 1;
153 return &ei->vfs_inode;
154 }
155
156 static void ext2_destroy_inode(struct inode *inode)
157 {
158 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
159 }
160
161 static void init_once(struct kmem_cache * cachep, void *foo)
162 {
163 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
164
165 rwlock_init(&ei->i_meta_lock);
166 #ifdef CONFIG_EXT2_FS_XATTR
167 init_rwsem(&ei->xattr_sem);
168 #endif
169 mutex_init(&ei->truncate_mutex);
170 inode_init_once(&ei->vfs_inode);
171 }
172
173 static int init_inodecache(void)
174 {
175 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
176 sizeof(struct ext2_inode_info),
177 0, (SLAB_RECLAIM_ACCOUNT|
178 SLAB_MEM_SPREAD),
179 init_once);
180 if (ext2_inode_cachep == NULL)
181 return -ENOMEM;
182 return 0;
183 }
184
185 static void destroy_inodecache(void)
186 {
187 kmem_cache_destroy(ext2_inode_cachep);
188 }
189
190 static void ext2_clear_inode(struct inode *inode)
191 {
192 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
193 #ifdef CONFIG_EXT2_FS_POSIX_ACL
194 struct ext2_inode_info *ei = EXT2_I(inode);
195
196 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
197 posix_acl_release(ei->i_acl);
198 ei->i_acl = EXT2_ACL_NOT_CACHED;
199 }
200 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
201 posix_acl_release(ei->i_default_acl);
202 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
203 }
204 #endif
205 ext2_discard_reservation(inode);
206 EXT2_I(inode)->i_block_alloc_info = NULL;
207 if (unlikely(rsv))
208 kfree(rsv);
209 }
210
211 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
212 {
213 struct super_block *sb = vfs->mnt_sb;
214 struct ext2_sb_info *sbi = EXT2_SB(sb);
215 struct ext2_super_block *es = sbi->s_es;
216 unsigned long def_mount_opts;
217
218 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
219
220 if (sbi->s_sb_block != 1)
221 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
222 if (test_opt(sb, MINIX_DF))
223 seq_puts(seq, ",minixdf");
224 if (test_opt(sb, GRPID))
225 seq_puts(seq, ",grpid");
226 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
227 seq_puts(seq, ",nogrpid");
228 if (sbi->s_resuid != EXT2_DEF_RESUID ||
229 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
230 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
231 }
232 if (sbi->s_resgid != EXT2_DEF_RESGID ||
233 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
234 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
235 }
236 if (test_opt(sb, ERRORS_RO)) {
237 int def_errors = le16_to_cpu(es->s_errors);
238
239 if (def_errors == EXT2_ERRORS_PANIC ||
240 def_errors == EXT2_ERRORS_CONTINUE) {
241 seq_puts(seq, ",errors=remount-ro");
242 }
243 }
244 if (test_opt(sb, ERRORS_CONT))
245 seq_puts(seq, ",errors=continue");
246 if (test_opt(sb, ERRORS_PANIC))
247 seq_puts(seq, ",errors=panic");
248 if (test_opt(sb, NO_UID32))
249 seq_puts(seq, ",nouid32");
250 if (test_opt(sb, DEBUG))
251 seq_puts(seq, ",debug");
252 if (test_opt(sb, OLDALLOC))
253 seq_puts(seq, ",oldalloc");
254
255 #ifdef CONFIG_EXT2_FS_XATTR
256 if (test_opt(sb, XATTR_USER))
257 seq_puts(seq, ",user_xattr");
258 if (!test_opt(sb, XATTR_USER) &&
259 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
260 seq_puts(seq, ",nouser_xattr");
261 }
262 #endif
263
264 #ifdef CONFIG_EXT2_FS_POSIX_ACL
265 if (test_opt(sb, POSIX_ACL))
266 seq_puts(seq, ",acl");
267 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
268 seq_puts(seq, ",noacl");
269 #endif
270
271 if (test_opt(sb, NOBH))
272 seq_puts(seq, ",nobh");
273
274 #if defined(CONFIG_QUOTA)
275 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
276 seq_puts(seq, ",usrquota");
277
278 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
279 seq_puts(seq, ",grpquota");
280 #endif
281
282 #if defined(CONFIG_EXT2_FS_XIP)
283 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
284 seq_puts(seq, ",xip");
285 #endif
286
287 if (!test_opt(sb, RESERVATION))
288 seq_puts(seq, ",noreservation");
289
290 return 0;
291 }
292
293 #ifdef CONFIG_QUOTA
294 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
295 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
296 #endif
297
298 static const struct super_operations ext2_sops = {
299 .alloc_inode = ext2_alloc_inode,
300 .destroy_inode = ext2_destroy_inode,
301 .write_inode = ext2_write_inode,
302 .delete_inode = ext2_delete_inode,
303 .put_super = ext2_put_super,
304 .write_super = ext2_write_super,
305 .statfs = ext2_statfs,
306 .remount_fs = ext2_remount,
307 .clear_inode = ext2_clear_inode,
308 .show_options = ext2_show_options,
309 #ifdef CONFIG_QUOTA
310 .quota_read = ext2_quota_read,
311 .quota_write = ext2_quota_write,
312 #endif
313 };
314
315 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
316 u64 ino, u32 generation)
317 {
318 struct inode *inode;
319
320 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
321 return ERR_PTR(-ESTALE);
322 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
323 return ERR_PTR(-ESTALE);
324
325 /* iget isn't really right if the inode is currently unallocated!!
326 * ext2_read_inode currently does appropriate checks, but
327 * it might be "neater" to call ext2_get_inode first and check
328 * if the inode is valid.....
329 */
330 inode = ext2_iget(sb, ino);
331 if (IS_ERR(inode))
332 return ERR_CAST(inode);
333 if (generation && inode->i_generation != generation) {
334 /* we didn't find the right inode.. */
335 iput(inode);
336 return ERR_PTR(-ESTALE);
337 }
338 return inode;
339 }
340
341 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
342 int fh_len, int fh_type)
343 {
344 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
345 ext2_nfs_get_inode);
346 }
347
348 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
349 int fh_len, int fh_type)
350 {
351 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
352 ext2_nfs_get_inode);
353 }
354
355 /* Yes, most of these are left as NULL!!
356 * A NULL value implies the default, which works with ext2-like file
357 * systems, but can be improved upon.
358 * Currently only get_parent is required.
359 */
360 static const struct export_operations ext2_export_ops = {
361 .fh_to_dentry = ext2_fh_to_dentry,
362 .fh_to_parent = ext2_fh_to_parent,
363 .get_parent = ext2_get_parent,
364 };
365
366 static unsigned long get_sb_block(void **data)
367 {
368 unsigned long sb_block;
369 char *options = (char *) *data;
370
371 if (!options || strncmp(options, "sb=", 3) != 0)
372 return 1; /* Default location */
373 options += 3;
374 sb_block = simple_strtoul(options, &options, 0);
375 if (*options && *options != ',') {
376 printk("EXT2-fs: Invalid sb specification: %s\n",
377 (char *) *data);
378 return 1;
379 }
380 if (*options == ',')
381 options++;
382 *data = (void *) options;
383 return sb_block;
384 }
385
386 enum {
387 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
388 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
389 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
390 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
391 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
392 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
393 };
394
395 static match_table_t tokens = {
396 {Opt_bsd_df, "bsddf"},
397 {Opt_minix_df, "minixdf"},
398 {Opt_grpid, "grpid"},
399 {Opt_grpid, "bsdgroups"},
400 {Opt_nogrpid, "nogrpid"},
401 {Opt_nogrpid, "sysvgroups"},
402 {Opt_resgid, "resgid=%u"},
403 {Opt_resuid, "resuid=%u"},
404 {Opt_sb, "sb=%u"},
405 {Opt_err_cont, "errors=continue"},
406 {Opt_err_panic, "errors=panic"},
407 {Opt_err_ro, "errors=remount-ro"},
408 {Opt_nouid32, "nouid32"},
409 {Opt_nocheck, "check=none"},
410 {Opt_nocheck, "nocheck"},
411 {Opt_debug, "debug"},
412 {Opt_oldalloc, "oldalloc"},
413 {Opt_orlov, "orlov"},
414 {Opt_nobh, "nobh"},
415 {Opt_user_xattr, "user_xattr"},
416 {Opt_nouser_xattr, "nouser_xattr"},
417 {Opt_acl, "acl"},
418 {Opt_noacl, "noacl"},
419 {Opt_xip, "xip"},
420 {Opt_grpquota, "grpquota"},
421 {Opt_ignore, "noquota"},
422 {Opt_quota, "quota"},
423 {Opt_usrquota, "usrquota"},
424 {Opt_reservation, "reservation"},
425 {Opt_noreservation, "noreservation"},
426 {Opt_err, NULL}
427 };
428
429 static int parse_options (char * options,
430 struct ext2_sb_info *sbi)
431 {
432 char * p;
433 substring_t args[MAX_OPT_ARGS];
434 int option;
435
436 if (!options)
437 return 1;
438
439 while ((p = strsep (&options, ",")) != NULL) {
440 int token;
441 if (!*p)
442 continue;
443
444 token = match_token(p, tokens, args);
445 switch (token) {
446 case Opt_bsd_df:
447 clear_opt (sbi->s_mount_opt, MINIX_DF);
448 break;
449 case Opt_minix_df:
450 set_opt (sbi->s_mount_opt, MINIX_DF);
451 break;
452 case Opt_grpid:
453 set_opt (sbi->s_mount_opt, GRPID);
454 break;
455 case Opt_nogrpid:
456 clear_opt (sbi->s_mount_opt, GRPID);
457 break;
458 case Opt_resuid:
459 if (match_int(&args[0], &option))
460 return 0;
461 sbi->s_resuid = option;
462 break;
463 case Opt_resgid:
464 if (match_int(&args[0], &option))
465 return 0;
466 sbi->s_resgid = option;
467 break;
468 case Opt_sb:
469 /* handled by get_sb_block() instead of here */
470 /* *sb_block = match_int(&args[0]); */
471 break;
472 case Opt_err_panic:
473 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
474 clear_opt (sbi->s_mount_opt, ERRORS_RO);
475 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
476 break;
477 case Opt_err_ro:
478 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
479 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
480 set_opt (sbi->s_mount_opt, ERRORS_RO);
481 break;
482 case Opt_err_cont:
483 clear_opt (sbi->s_mount_opt, ERRORS_RO);
484 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
485 set_opt (sbi->s_mount_opt, ERRORS_CONT);
486 break;
487 case Opt_nouid32:
488 set_opt (sbi->s_mount_opt, NO_UID32);
489 break;
490 case Opt_nocheck:
491 clear_opt (sbi->s_mount_opt, CHECK);
492 break;
493 case Opt_debug:
494 set_opt (sbi->s_mount_opt, DEBUG);
495 break;
496 case Opt_oldalloc:
497 set_opt (sbi->s_mount_opt, OLDALLOC);
498 break;
499 case Opt_orlov:
500 clear_opt (sbi->s_mount_opt, OLDALLOC);
501 break;
502 case Opt_nobh:
503 set_opt (sbi->s_mount_opt, NOBH);
504 break;
505 #ifdef CONFIG_EXT2_FS_XATTR
506 case Opt_user_xattr:
507 set_opt (sbi->s_mount_opt, XATTR_USER);
508 break;
509 case Opt_nouser_xattr:
510 clear_opt (sbi->s_mount_opt, XATTR_USER);
511 break;
512 #else
513 case Opt_user_xattr:
514 case Opt_nouser_xattr:
515 printk("EXT2 (no)user_xattr options not supported\n");
516 break;
517 #endif
518 #ifdef CONFIG_EXT2_FS_POSIX_ACL
519 case Opt_acl:
520 set_opt(sbi->s_mount_opt, POSIX_ACL);
521 break;
522 case Opt_noacl:
523 clear_opt(sbi->s_mount_opt, POSIX_ACL);
524 break;
525 #else
526 case Opt_acl:
527 case Opt_noacl:
528 printk("EXT2 (no)acl options not supported\n");
529 break;
530 #endif
531 case Opt_xip:
532 #ifdef CONFIG_EXT2_FS_XIP
533 set_opt (sbi->s_mount_opt, XIP);
534 #else
535 printk("EXT2 xip option not supported\n");
536 #endif
537 break;
538
539 #if defined(CONFIG_QUOTA)
540 case Opt_quota:
541 case Opt_usrquota:
542 set_opt(sbi->s_mount_opt, USRQUOTA);
543 break;
544
545 case Opt_grpquota:
546 set_opt(sbi->s_mount_opt, GRPQUOTA);
547 break;
548 #else
549 case Opt_quota:
550 case Opt_usrquota:
551 case Opt_grpquota:
552 printk(KERN_ERR
553 "EXT2-fs: quota operations not supported.\n");
554
555 break;
556 #endif
557
558 case Opt_reservation:
559 set_opt(sbi->s_mount_opt, RESERVATION);
560 printk("reservations ON\n");
561 break;
562 case Opt_noreservation:
563 clear_opt(sbi->s_mount_opt, RESERVATION);
564 printk("reservations OFF\n");
565 break;
566 case Opt_ignore:
567 break;
568 default:
569 return 0;
570 }
571 }
572 return 1;
573 }
574
575 static int ext2_setup_super (struct super_block * sb,
576 struct ext2_super_block * es,
577 int read_only)
578 {
579 int res = 0;
580 struct ext2_sb_info *sbi = EXT2_SB(sb);
581
582 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
583 printk ("EXT2-fs warning: revision level too high, "
584 "forcing read-only mode\n");
585 res = MS_RDONLY;
586 }
587 if (read_only)
588 return res;
589 if (!(sbi->s_mount_state & EXT2_VALID_FS))
590 printk ("EXT2-fs warning: mounting unchecked fs, "
591 "running e2fsck is recommended\n");
592 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
593 printk ("EXT2-fs warning: mounting fs with errors, "
594 "running e2fsck is recommended\n");
595 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
596 le16_to_cpu(es->s_mnt_count) >=
597 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
598 printk ("EXT2-fs warning: maximal mount count reached, "
599 "running e2fsck is recommended\n");
600 else if (le32_to_cpu(es->s_checkinterval) &&
601 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
602 printk ("EXT2-fs warning: checktime reached, "
603 "running e2fsck is recommended\n");
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 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
610 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
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 sb->s_fs_info = sbi;
759 sbi->s_sb_block = sb_block;
760
761 /*
762 * See what the current blocksize for the device is, and
763 * use that as the blocksize. Otherwise (or if the blocksize
764 * is smaller than the default) use the default.
765 * This is important for devices that have a hardware
766 * sectorsize that is larger than the default.
767 */
768 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
769 if (!blocksize) {
770 printk ("EXT2-fs: unable to set blocksize\n");
771 goto failed_sbi;
772 }
773
774 /*
775 * If the superblock doesn't start on a hardware sector boundary,
776 * calculate the offset.
777 */
778 if (blocksize != BLOCK_SIZE) {
779 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
780 offset = (sb_block*BLOCK_SIZE) % blocksize;
781 } else {
782 logic_sb_block = sb_block;
783 }
784
785 if (!(bh = sb_bread(sb, logic_sb_block))) {
786 printk ("EXT2-fs: unable to read superblock\n");
787 goto failed_sbi;
788 }
789 /*
790 * Note: s_es must be initialized as soon as possible because
791 * some ext2 macro-instructions depend on its value
792 */
793 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
794 sbi->s_es = es;
795 sb->s_magic = le16_to_cpu(es->s_magic);
796
797 if (sb->s_magic != EXT2_SUPER_MAGIC)
798 goto cantfind_ext2;
799
800 /* Set defaults before we parse the mount options */
801 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
802 if (def_mount_opts & EXT2_DEFM_DEBUG)
803 set_opt(sbi->s_mount_opt, DEBUG);
804 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
805 set_opt(sbi->s_mount_opt, GRPID);
806 if (def_mount_opts & EXT2_DEFM_UID16)
807 set_opt(sbi->s_mount_opt, NO_UID32);
808 #ifdef CONFIG_EXT2_FS_XATTR
809 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
810 set_opt(sbi->s_mount_opt, XATTR_USER);
811 #endif
812 #ifdef CONFIG_EXT2_FS_POSIX_ACL
813 if (def_mount_opts & EXT2_DEFM_ACL)
814 set_opt(sbi->s_mount_opt, POSIX_ACL);
815 #endif
816
817 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
818 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
819 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
820 set_opt(sbi->s_mount_opt, ERRORS_CONT);
821 else
822 set_opt(sbi->s_mount_opt, ERRORS_RO);
823
824 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
825 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
826
827 set_opt(sbi->s_mount_opt, RESERVATION);
828
829 if (!parse_options ((char *) data, sbi))
830 goto failed_mount;
831
832 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
833 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
834 MS_POSIXACL : 0);
835
836 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
837 EXT2_MOUNT_XIP if not */
838
839 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
840 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
841 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
842 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
843 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
844 "running e2fsck is recommended\n");
845 /*
846 * Check feature flags regardless of the revision level, since we
847 * previously didn't change the revision level when setting the flags,
848 * so there is a chance incompat flags are set on a rev 0 filesystem.
849 */
850 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
851 if (features) {
852 printk("EXT2-fs: %s: couldn't mount because of "
853 "unsupported optional features (%x).\n",
854 sb->s_id, le32_to_cpu(features));
855 goto failed_mount;
856 }
857 if (!(sb->s_flags & MS_RDONLY) &&
858 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
859 printk("EXT2-fs: %s: couldn't mount RDWR because of "
860 "unsupported optional features (%x).\n",
861 sb->s_id, le32_to_cpu(features));
862 goto failed_mount;
863 }
864
865 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
866
867 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
868 if (!silent)
869 printk("XIP: Unsupported blocksize\n");
870 goto failed_mount;
871 }
872
873 /* If the blocksize doesn't match, re-read the thing.. */
874 if (sb->s_blocksize != blocksize) {
875 brelse(bh);
876
877 if (!sb_set_blocksize(sb, blocksize)) {
878 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
879 goto failed_sbi;
880 }
881
882 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
883 offset = (sb_block*BLOCK_SIZE) % blocksize;
884 bh = sb_bread(sb, logic_sb_block);
885 if(!bh) {
886 printk("EXT2-fs: Couldn't read superblock on "
887 "2nd try.\n");
888 goto failed_sbi;
889 }
890 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
891 sbi->s_es = es;
892 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
893 printk ("EXT2-fs: Magic mismatch, very weird !\n");
894 goto failed_mount;
895 }
896 }
897
898 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
899
900 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
901 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
902 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
903 } else {
904 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
905 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
906 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
907 !is_power_of_2(sbi->s_inode_size) ||
908 (sbi->s_inode_size > blocksize)) {
909 printk ("EXT2-fs: unsupported inode size: %d\n",
910 sbi->s_inode_size);
911 goto failed_mount;
912 }
913 }
914
915 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
916 le32_to_cpu(es->s_log_frag_size);
917 if (sbi->s_frag_size == 0)
918 goto cantfind_ext2;
919 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
920
921 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
922 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
923 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
924
925 if (EXT2_INODE_SIZE(sb) == 0)
926 goto cantfind_ext2;
927 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
928 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
929 goto cantfind_ext2;
930 sbi->s_itb_per_group = sbi->s_inodes_per_group /
931 sbi->s_inodes_per_block;
932 sbi->s_desc_per_block = sb->s_blocksize /
933 sizeof (struct ext2_group_desc);
934 sbi->s_sbh = bh;
935 sbi->s_mount_state = le16_to_cpu(es->s_state);
936 sbi->s_addr_per_block_bits =
937 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
938 sbi->s_desc_per_block_bits =
939 ilog2 (EXT2_DESC_PER_BLOCK(sb));
940
941 if (sb->s_magic != EXT2_SUPER_MAGIC)
942 goto cantfind_ext2;
943
944 if (sb->s_blocksize != bh->b_size) {
945 if (!silent)
946 printk ("VFS: Unsupported blocksize on dev "
947 "%s.\n", sb->s_id);
948 goto failed_mount;
949 }
950
951 if (sb->s_blocksize != sbi->s_frag_size) {
952 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
953 sbi->s_frag_size, sb->s_blocksize);
954 goto failed_mount;
955 }
956
957 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
958 printk ("EXT2-fs: #blocks per group too big: %lu\n",
959 sbi->s_blocks_per_group);
960 goto failed_mount;
961 }
962 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
963 printk ("EXT2-fs: #fragments per group too big: %lu\n",
964 sbi->s_frags_per_group);
965 goto failed_mount;
966 }
967 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
968 printk ("EXT2-fs: #inodes per group too big: %lu\n",
969 sbi->s_inodes_per_group);
970 goto failed_mount;
971 }
972
973 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
974 goto cantfind_ext2;
975 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
976 le32_to_cpu(es->s_first_data_block) - 1)
977 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
978 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
979 EXT2_DESC_PER_BLOCK(sb);
980 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
981 if (sbi->s_group_desc == NULL) {
982 printk ("EXT2-fs: not enough memory\n");
983 goto failed_mount;
984 }
985 bgl_lock_init(&sbi->s_blockgroup_lock);
986 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
987 if (!sbi->s_debts) {
988 printk ("EXT2-fs: not enough memory\n");
989 goto failed_mount_group_desc;
990 }
991 for (i = 0; i < db_count; i++) {
992 block = descriptor_loc(sb, logic_sb_block, i);
993 sbi->s_group_desc[i] = sb_bread(sb, block);
994 if (!sbi->s_group_desc[i]) {
995 for (j = 0; j < i; j++)
996 brelse (sbi->s_group_desc[j]);
997 printk ("EXT2-fs: unable to read group descriptors\n");
998 goto failed_mount_group_desc;
999 }
1000 }
1001 if (!ext2_check_descriptors (sb)) {
1002 printk ("EXT2-fs: group descriptors corrupted!\n");
1003 goto failed_mount2;
1004 }
1005 sbi->s_gdb_count = db_count;
1006 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1007 spin_lock_init(&sbi->s_next_gen_lock);
1008
1009 /* per fileystem reservation list head & lock */
1010 spin_lock_init(&sbi->s_rsv_window_lock);
1011 sbi->s_rsv_window_root = RB_ROOT;
1012 /*
1013 * Add a single, static dummy reservation to the start of the
1014 * reservation window list --- it gives us a placeholder for
1015 * append-at-start-of-list which makes the allocation logic
1016 * _much_ simpler.
1017 */
1018 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1019 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1020 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1021 sbi->s_rsv_window_head.rsv_goal_size = 0;
1022 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1023
1024 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1025 ext2_count_free_blocks(sb));
1026 if (!err) {
1027 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1028 ext2_count_free_inodes(sb));
1029 }
1030 if (!err) {
1031 err = percpu_counter_init(&sbi->s_dirs_counter,
1032 ext2_count_dirs(sb));
1033 }
1034 if (err) {
1035 printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1036 goto failed_mount3;
1037 }
1038 /*
1039 * set up enough so that it can read an inode
1040 */
1041 sb->s_op = &ext2_sops;
1042 sb->s_export_op = &ext2_export_ops;
1043 sb->s_xattr = ext2_xattr_handlers;
1044 root = ext2_iget(sb, EXT2_ROOT_INO);
1045 if (IS_ERR(root)) {
1046 ret = PTR_ERR(root);
1047 goto failed_mount3;
1048 }
1049 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1050 iput(root);
1051 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1052 goto failed_mount3;
1053 }
1054
1055 sb->s_root = d_alloc_root(root);
1056 if (!sb->s_root) {
1057 iput(root);
1058 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1059 ret = -ENOMEM;
1060 goto failed_mount3;
1061 }
1062 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1063 ext2_warning(sb, __func__,
1064 "mounting ext3 filesystem as ext2");
1065 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1066 return 0;
1067
1068 cantfind_ext2:
1069 if (!silent)
1070 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1071 sb->s_id);
1072 goto failed_mount;
1073 failed_mount3:
1074 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1075 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1076 percpu_counter_destroy(&sbi->s_dirs_counter);
1077 failed_mount2:
1078 for (i = 0; i < db_count; i++)
1079 brelse(sbi->s_group_desc[i]);
1080 failed_mount_group_desc:
1081 kfree(sbi->s_group_desc);
1082 kfree(sbi->s_debts);
1083 failed_mount:
1084 brelse(bh);
1085 failed_sbi:
1086 sb->s_fs_info = NULL;
1087 kfree(sbi);
1088 return ret;
1089 }
1090
1091 static void ext2_commit_super (struct super_block * sb,
1092 struct ext2_super_block * es)
1093 {
1094 es->s_wtime = cpu_to_le32(get_seconds());
1095 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1096 sb->s_dirt = 0;
1097 }
1098
1099 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1100 {
1101 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1102 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1103 es->s_wtime = cpu_to_le32(get_seconds());
1104 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1105 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1106 sb->s_dirt = 0;
1107 }
1108
1109 /*
1110 * In the second extended file system, it is not necessary to
1111 * write the super block since we use a mapping of the
1112 * disk super block in a buffer.
1113 *
1114 * However, this function is still used to set the fs valid
1115 * flags to 0. We need to set this flag to 0 since the fs
1116 * may have been checked while mounted and e2fsck may have
1117 * set s_state to EXT2_VALID_FS after some corrections.
1118 */
1119
1120 void ext2_write_super (struct super_block * sb)
1121 {
1122 struct ext2_super_block * es;
1123 lock_kernel();
1124 if (!(sb->s_flags & MS_RDONLY)) {
1125 es = EXT2_SB(sb)->s_es;
1126
1127 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1128 ext2_debug ("setting valid to 0\n");
1129 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1130 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1131 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1132 es->s_mtime = cpu_to_le32(get_seconds());
1133 ext2_sync_super(sb, es);
1134 } else
1135 ext2_commit_super (sb, es);
1136 }
1137 sb->s_dirt = 0;
1138 unlock_kernel();
1139 }
1140
1141 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1142 {
1143 struct ext2_sb_info * sbi = EXT2_SB(sb);
1144 struct ext2_super_block * es;
1145 unsigned long old_mount_opt = sbi->s_mount_opt;
1146 struct ext2_mount_options old_opts;
1147 unsigned long old_sb_flags;
1148 int err;
1149
1150 /* Store the old options */
1151 old_sb_flags = sb->s_flags;
1152 old_opts.s_mount_opt = sbi->s_mount_opt;
1153 old_opts.s_resuid = sbi->s_resuid;
1154 old_opts.s_resgid = sbi->s_resgid;
1155
1156 /*
1157 * Allow the "check" option to be passed as a remount option.
1158 */
1159 if (!parse_options (data, sbi)) {
1160 err = -EINVAL;
1161 goto restore_opts;
1162 }
1163
1164 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1165 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1166
1167 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1168 EXT2_MOUNT_XIP if not */
1169
1170 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1171 printk("XIP: Unsupported blocksize\n");
1172 err = -EINVAL;
1173 goto restore_opts;
1174 }
1175
1176 es = sbi->s_es;
1177 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1178 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1179 invalidate_inodes(sb))
1180 ext2_warning(sb, __func__, "busy inodes while remounting "\
1181 "xip remain in cache (no functional problem)");
1182 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1183 return 0;
1184 if (*flags & MS_RDONLY) {
1185 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1186 !(sbi->s_mount_state & EXT2_VALID_FS))
1187 return 0;
1188 /*
1189 * OK, we are remounting a valid rw partition rdonly, so set
1190 * the rdonly flag and then mark the partition as valid again.
1191 */
1192 es->s_state = cpu_to_le16(sbi->s_mount_state);
1193 es->s_mtime = cpu_to_le32(get_seconds());
1194 } else {
1195 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1196 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1197 if (ret) {
1198 printk("EXT2-fs: %s: couldn't remount RDWR because of "
1199 "unsupported optional features (%x).\n",
1200 sb->s_id, le32_to_cpu(ret));
1201 err = -EROFS;
1202 goto restore_opts;
1203 }
1204 /*
1205 * Mounting a RDONLY partition read-write, so reread and
1206 * store the current valid flag. (It may have been changed
1207 * by e2fsck since we originally mounted the partition.)
1208 */
1209 sbi->s_mount_state = le16_to_cpu(es->s_state);
1210 if (!ext2_setup_super (sb, es, 0))
1211 sb->s_flags &= ~MS_RDONLY;
1212 }
1213 ext2_sync_super(sb, es);
1214 return 0;
1215 restore_opts:
1216 sbi->s_mount_opt = old_opts.s_mount_opt;
1217 sbi->s_resuid = old_opts.s_resuid;
1218 sbi->s_resgid = old_opts.s_resgid;
1219 sb->s_flags = old_sb_flags;
1220 return err;
1221 }
1222
1223 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1224 {
1225 struct super_block *sb = dentry->d_sb;
1226 struct ext2_sb_info *sbi = EXT2_SB(sb);
1227 struct ext2_super_block *es = sbi->s_es;
1228 u64 fsid;
1229
1230 if (test_opt (sb, MINIX_DF))
1231 sbi->s_overhead_last = 0;
1232 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1233 unsigned long i, overhead = 0;
1234 smp_rmb();
1235
1236 /*
1237 * Compute the overhead (FS structures). This is constant
1238 * for a given filesystem unless the number of block groups
1239 * changes so we cache the previous value until it does.
1240 */
1241
1242 /*
1243 * All of the blocks before first_data_block are
1244 * overhead
1245 */
1246 overhead = le32_to_cpu(es->s_first_data_block);
1247
1248 /*
1249 * Add the overhead attributed to the superblock and
1250 * block group descriptors. If the sparse superblocks
1251 * feature is turned on, then not all groups have this.
1252 */
1253 for (i = 0; i < sbi->s_groups_count; i++)
1254 overhead += ext2_bg_has_super(sb, i) +
1255 ext2_bg_num_gdb(sb, i);
1256
1257 /*
1258 * Every block group has an inode bitmap, a block
1259 * bitmap, and an inode table.
1260 */
1261 overhead += (sbi->s_groups_count *
1262 (2 + sbi->s_itb_per_group));
1263 sbi->s_overhead_last = overhead;
1264 smp_wmb();
1265 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1266 }
1267
1268 buf->f_type = EXT2_SUPER_MAGIC;
1269 buf->f_bsize = sb->s_blocksize;
1270 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1271 buf->f_bfree = ext2_count_free_blocks(sb);
1272 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1273 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1274 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1275 buf->f_bavail = 0;
1276 buf->f_files = le32_to_cpu(es->s_inodes_count);
1277 buf->f_ffree = ext2_count_free_inodes(sb);
1278 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1279 buf->f_namelen = EXT2_NAME_LEN;
1280 fsid = le64_to_cpup((void *)es->s_uuid) ^
1281 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1282 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1283 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1284 return 0;
1285 }
1286
1287 static int ext2_get_sb(struct file_system_type *fs_type,
1288 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1289 {
1290 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1291 }
1292
1293 #ifdef CONFIG_QUOTA
1294
1295 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1296 * acquiring the locks... As quota files are never truncated and quota code
1297 * itself serializes the operations (and noone else should touch the files)
1298 * we don't have to be afraid of races */
1299 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1300 size_t len, loff_t off)
1301 {
1302 struct inode *inode = sb_dqopt(sb)->files[type];
1303 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1304 int err = 0;
1305 int offset = off & (sb->s_blocksize - 1);
1306 int tocopy;
1307 size_t toread;
1308 struct buffer_head tmp_bh;
1309 struct buffer_head *bh;
1310 loff_t i_size = i_size_read(inode);
1311
1312 if (off > i_size)
1313 return 0;
1314 if (off+len > i_size)
1315 len = i_size-off;
1316 toread = len;
1317 while (toread > 0) {
1318 tocopy = sb->s_blocksize - offset < toread ?
1319 sb->s_blocksize - offset : toread;
1320
1321 tmp_bh.b_state = 0;
1322 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1323 if (err < 0)
1324 return err;
1325 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1326 memset(data, 0, tocopy);
1327 else {
1328 bh = sb_bread(sb, tmp_bh.b_blocknr);
1329 if (!bh)
1330 return -EIO;
1331 memcpy(data, bh->b_data+offset, tocopy);
1332 brelse(bh);
1333 }
1334 offset = 0;
1335 toread -= tocopy;
1336 data += tocopy;
1337 blk++;
1338 }
1339 return len;
1340 }
1341
1342 /* Write to quotafile */
1343 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1344 const char *data, size_t len, loff_t off)
1345 {
1346 struct inode *inode = sb_dqopt(sb)->files[type];
1347 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1348 int err = 0;
1349 int offset = off & (sb->s_blocksize - 1);
1350 int tocopy;
1351 size_t towrite = len;
1352 struct buffer_head tmp_bh;
1353 struct buffer_head *bh;
1354
1355 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1356 while (towrite > 0) {
1357 tocopy = sb->s_blocksize - offset < towrite ?
1358 sb->s_blocksize - offset : towrite;
1359
1360 tmp_bh.b_state = 0;
1361 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1362 if (err < 0)
1363 goto out;
1364 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1365 bh = sb_bread(sb, tmp_bh.b_blocknr);
1366 else
1367 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1368 if (!bh) {
1369 err = -EIO;
1370 goto out;
1371 }
1372 lock_buffer(bh);
1373 memcpy(bh->b_data+offset, data, tocopy);
1374 flush_dcache_page(bh->b_page);
1375 set_buffer_uptodate(bh);
1376 mark_buffer_dirty(bh);
1377 unlock_buffer(bh);
1378 brelse(bh);
1379 offset = 0;
1380 towrite -= tocopy;
1381 data += tocopy;
1382 blk++;
1383 }
1384 out:
1385 if (len == towrite)
1386 return err;
1387 if (inode->i_size < off+len-towrite)
1388 i_size_write(inode, off+len-towrite);
1389 inode->i_version++;
1390 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1391 mark_inode_dirty(inode);
1392 mutex_unlock(&inode->i_mutex);
1393 return len - towrite;
1394 }
1395
1396 #endif
1397
1398 static struct file_system_type ext2_fs_type = {
1399 .owner = THIS_MODULE,
1400 .name = "ext2",
1401 .get_sb = ext2_get_sb,
1402 .kill_sb = kill_block_super,
1403 .fs_flags = FS_REQUIRES_DEV,
1404 };
1405
1406 static int __init init_ext2_fs(void)
1407 {
1408 int err = init_ext2_xattr();
1409 if (err)
1410 return err;
1411 err = init_inodecache();
1412 if (err)
1413 goto out1;
1414 err = register_filesystem(&ext2_fs_type);
1415 if (err)
1416 goto out;
1417 return 0;
1418 out:
1419 destroy_inodecache();
1420 out1:
1421 exit_ext2_xattr();
1422 return err;
1423 }
1424
1425 static void __exit exit_ext2_fs(void)
1426 {
1427 unregister_filesystem(&ext2_fs_type);
1428 destroy_inodecache();
1429 exit_ext2_xattr();
1430 }
1431
1432 module_init(init_ext2_fs)
1433 module_exit(exit_ext2_fs)
kernel-based virtual machine