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Merge git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb
[pv_ops_mirror.git] / fs / ext2 / super.c
blob154e25f13d772235e7c7d242a0b5e6fdbf977cd7
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 inode *ext2_nfs_get_inode(struct super_block *sb,
315 u64 ino, u32 generation)
316 {
317 struct inode *inode;
318
319 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
320 return ERR_PTR(-ESTALE);
321 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
322 return ERR_PTR(-ESTALE);
323
324 /* iget isn't really right if the inode is currently unallocated!!
325 * ext2_read_inode currently does appropriate checks, but
326 * it might be "neater" to call ext2_get_inode first and check
327 * if the inode is valid.....
328 */
329 inode = iget(sb, ino);
330 if (inode == NULL)
331 return ERR_PTR(-ENOMEM);
332 if (is_bad_inode(inode) ||
333 (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 es->s_mnt_count=cpu_to_le16(le16_to_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 int desc_block = 0;
624 struct ext2_sb_info *sbi = EXT2_SB(sb);
625 unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
626 unsigned long last_block;
627 struct ext2_group_desc * gdp = NULL;
628
629 ext2_debug ("Checking group descriptors");
630
631 for (i = 0; i < sbi->s_groups_count; i++)
632 {
633 if (i == sbi->s_groups_count - 1)
634 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
635 else
636 last_block = first_block +
637 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
638
639 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
640 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
641 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
642 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
643 {
644 ext2_error (sb, "ext2_check_descriptors",
645 "Block bitmap for group %d"
646 " not in group (block %lu)!",
647 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
648 return 0;
649 }
650 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
651 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
652 {
653 ext2_error (sb, "ext2_check_descriptors",
654 "Inode bitmap for group %d"
655 " not in group (block %lu)!",
656 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
657 return 0;
658 }
659 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
660 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
661 last_block)
662 {
663 ext2_error (sb, "ext2_check_descriptors",
664 "Inode table for group %d"
665 " not in group (block %lu)!",
666 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
667 return 0;
668 }
669 first_block += EXT2_BLOCKS_PER_GROUP(sb);
670 gdp++;
671 }
672 return 1;
673 }
674
675 /*
676 * Maximal file size. There is a direct, and {,double-,triple-}indirect
677 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
678 * We need to be 1 filesystem block less than the 2^32 sector limit.
679 */
680 static loff_t ext2_max_size(int bits)
681 {
682 loff_t res = EXT2_NDIR_BLOCKS;
683 /* This constant is calculated to be the largest file size for a
684 * dense, 4k-blocksize file such that the total number of
685 * sectors in the file, including data and all indirect blocks,
686 * does not exceed 2^32. */
687 const loff_t upper_limit = 0x1ff7fffd000LL;
688
689 res += 1LL << (bits-2);
690 res += 1LL << (2*(bits-2));
691 res += 1LL << (3*(bits-2));
692 res <<= bits;
693 if (res > upper_limit)
694 res = upper_limit;
695 return res;
696 }
697
698 static unsigned long descriptor_loc(struct super_block *sb,
699 unsigned long logic_sb_block,
700 int nr)
701 {
702 struct ext2_sb_info *sbi = EXT2_SB(sb);
703 unsigned long bg, first_data_block, first_meta_bg;
704 int has_super = 0;
705
706 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
707 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
708
709 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
710 nr < first_meta_bg)
711 return (logic_sb_block + nr + 1);
712 bg = sbi->s_desc_per_block * nr;
713 if (ext2_bg_has_super(sb, bg))
714 has_super = 1;
715 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
716 }
717
718 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
719 {
720 struct buffer_head * bh;
721 struct ext2_sb_info * sbi;
722 struct ext2_super_block * es;
723 struct inode *root;
724 unsigned long block;
725 unsigned long sb_block = get_sb_block(&data);
726 unsigned long logic_sb_block;
727 unsigned long offset = 0;
728 unsigned long def_mount_opts;
729 int blocksize = BLOCK_SIZE;
730 int db_count;
731 int i, j;
732 __le32 features;
733 int err;
734
735 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
736 if (!sbi)
737 return -ENOMEM;
738 sb->s_fs_info = sbi;
739 sbi->s_sb_block = sb_block;
740
741 /*
742 * See what the current blocksize for the device is, and
743 * use that as the blocksize. Otherwise (or if the blocksize
744 * is smaller than the default) use the default.
745 * This is important for devices that have a hardware
746 * sectorsize that is larger than the default.
747 */
748 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
749 if (!blocksize) {
750 printk ("EXT2-fs: unable to set blocksize\n");
751 goto failed_sbi;
752 }
753
754 /*
755 * If the superblock doesn't start on a hardware sector boundary,
756 * calculate the offset.
757 */
758 if (blocksize != BLOCK_SIZE) {
759 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
760 offset = (sb_block*BLOCK_SIZE) % blocksize;
761 } else {
762 logic_sb_block = sb_block;
763 }
764
765 if (!(bh = sb_bread(sb, logic_sb_block))) {
766 printk ("EXT2-fs: unable to read superblock\n");
767 goto failed_sbi;
768 }
769 /*
770 * Note: s_es must be initialized as soon as possible because
771 * some ext2 macro-instructions depend on its value
772 */
773 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
774 sbi->s_es = es;
775 sb->s_magic = le16_to_cpu(es->s_magic);
776
777 if (sb->s_magic != EXT2_SUPER_MAGIC)
778 goto cantfind_ext2;
779
780 /* Set defaults before we parse the mount options */
781 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
782 if (def_mount_opts & EXT2_DEFM_DEBUG)
783 set_opt(sbi->s_mount_opt, DEBUG);
784 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
785 set_opt(sbi->s_mount_opt, GRPID);
786 if (def_mount_opts & EXT2_DEFM_UID16)
787 set_opt(sbi->s_mount_opt, NO_UID32);
788 #ifdef CONFIG_EXT2_FS_XATTR
789 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
790 set_opt(sbi->s_mount_opt, XATTR_USER);
791 #endif
792 #ifdef CONFIG_EXT2_FS_POSIX_ACL
793 if (def_mount_opts & EXT2_DEFM_ACL)
794 set_opt(sbi->s_mount_opt, POSIX_ACL);
795 #endif
796
797 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
798 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
799 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
800 set_opt(sbi->s_mount_opt, ERRORS_RO);
801 else
802 set_opt(sbi->s_mount_opt, ERRORS_CONT);
803
804 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
805 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
806
807 set_opt(sbi->s_mount_opt, RESERVATION);
808
809 if (!parse_options ((char *) data, sbi))
810 goto failed_mount;
811
812 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
813 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
814 MS_POSIXACL : 0);
815
816 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
817 EXT2_MOUNT_XIP if not */
818
819 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
820 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
821 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
822 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
823 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
824 "running e2fsck is recommended\n");
825 /*
826 * Check feature flags regardless of the revision level, since we
827 * previously didn't change the revision level when setting the flags,
828 * so there is a chance incompat flags are set on a rev 0 filesystem.
829 */
830 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
831 if (features) {
832 printk("EXT2-fs: %s: couldn't mount because of "
833 "unsupported optional features (%x).\n",
834 sb->s_id, le32_to_cpu(features));
835 goto failed_mount;
836 }
837 if (!(sb->s_flags & MS_RDONLY) &&
838 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
839 printk("EXT2-fs: %s: couldn't mount RDWR because of "
840 "unsupported optional features (%x).\n",
841 sb->s_id, le32_to_cpu(features));
842 goto failed_mount;
843 }
844
845 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
846
847 if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) ||
848 (sb->s_blocksize != blocksize))) {
849 if (!silent)
850 printk("XIP: Unsupported blocksize\n");
851 goto failed_mount;
852 }
853
854 /* If the blocksize doesn't match, re-read the thing.. */
855 if (sb->s_blocksize != blocksize) {
856 brelse(bh);
857
858 if (!sb_set_blocksize(sb, blocksize)) {
859 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
860 goto failed_sbi;
861 }
862
863 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
864 offset = (sb_block*BLOCK_SIZE) % blocksize;
865 bh = sb_bread(sb, logic_sb_block);
866 if(!bh) {
867 printk("EXT2-fs: Couldn't read superblock on "
868 "2nd try.\n");
869 goto failed_sbi;
870 }
871 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
872 sbi->s_es = es;
873 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
874 printk ("EXT2-fs: Magic mismatch, very weird !\n");
875 goto failed_mount;
876 }
877 }
878
879 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
880
881 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
882 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
883 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
884 } else {
885 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
886 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
887 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
888 !is_power_of_2(sbi->s_inode_size) ||
889 (sbi->s_inode_size > blocksize)) {
890 printk ("EXT2-fs: unsupported inode size: %d\n",
891 sbi->s_inode_size);
892 goto failed_mount;
893 }
894 }
895
896 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
897 le32_to_cpu(es->s_log_frag_size);
898 if (sbi->s_frag_size == 0)
899 goto cantfind_ext2;
900 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
901
902 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
903 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
904 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
905
906 if (EXT2_INODE_SIZE(sb) == 0)
907 goto cantfind_ext2;
908 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
909 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
910 goto cantfind_ext2;
911 sbi->s_itb_per_group = sbi->s_inodes_per_group /
912 sbi->s_inodes_per_block;
913 sbi->s_desc_per_block = sb->s_blocksize /
914 sizeof (struct ext2_group_desc);
915 sbi->s_sbh = bh;
916 sbi->s_mount_state = le16_to_cpu(es->s_state);
917 sbi->s_addr_per_block_bits =
918 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
919 sbi->s_desc_per_block_bits =
920 ilog2 (EXT2_DESC_PER_BLOCK(sb));
921
922 if (sb->s_magic != EXT2_SUPER_MAGIC)
923 goto cantfind_ext2;
924
925 if (sb->s_blocksize != bh->b_size) {
926 if (!silent)
927 printk ("VFS: Unsupported blocksize on dev "
928 "%s.\n", sb->s_id);
929 goto failed_mount;
930 }
931
932 if (sb->s_blocksize != sbi->s_frag_size) {
933 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
934 sbi->s_frag_size, sb->s_blocksize);
935 goto failed_mount;
936 }
937
938 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
939 printk ("EXT2-fs: #blocks per group too big: %lu\n",
940 sbi->s_blocks_per_group);
941 goto failed_mount;
942 }
943 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
944 printk ("EXT2-fs: #fragments per group too big: %lu\n",
945 sbi->s_frags_per_group);
946 goto failed_mount;
947 }
948 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
949 printk ("EXT2-fs: #inodes per group too big: %lu\n",
950 sbi->s_inodes_per_group);
951 goto failed_mount;
952 }
953
954 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
955 goto cantfind_ext2;
956 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
957 le32_to_cpu(es->s_first_data_block) - 1)
958 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
959 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
960 EXT2_DESC_PER_BLOCK(sb);
961 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
962 if (sbi->s_group_desc == NULL) {
963 printk ("EXT2-fs: not enough memory\n");
964 goto failed_mount;
965 }
966 bgl_lock_init(&sbi->s_blockgroup_lock);
967 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
968 if (!sbi->s_debts) {
969 printk ("EXT2-fs: not enough memory\n");
970 goto failed_mount_group_desc;
971 }
972 for (i = 0; i < db_count; i++) {
973 block = descriptor_loc(sb, logic_sb_block, i);
974 sbi->s_group_desc[i] = sb_bread(sb, block);
975 if (!sbi->s_group_desc[i]) {
976 for (j = 0; j < i; j++)
977 brelse (sbi->s_group_desc[j]);
978 printk ("EXT2-fs: unable to read group descriptors\n");
979 goto failed_mount_group_desc;
980 }
981 }
982 if (!ext2_check_descriptors (sb)) {
983 printk ("EXT2-fs: group descriptors corrupted!\n");
984 goto failed_mount2;
985 }
986 sbi->s_gdb_count = db_count;
987 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
988 spin_lock_init(&sbi->s_next_gen_lock);
989
990 /* per fileystem reservation list head & lock */
991 spin_lock_init(&sbi->s_rsv_window_lock);
992 sbi->s_rsv_window_root = RB_ROOT;
993 /*
994 * Add a single, static dummy reservation to the start of the
995 * reservation window list --- it gives us a placeholder for
996 * append-at-start-of-list which makes the allocation logic
997 * _much_ simpler.
998 */
999 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1000 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1001 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1002 sbi->s_rsv_window_head.rsv_goal_size = 0;
1003 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1004
1005 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1006 ext2_count_free_blocks(sb));
1007 if (!err) {
1008 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1009 ext2_count_free_inodes(sb));
1010 }
1011 if (!err) {
1012 err = percpu_counter_init(&sbi->s_dirs_counter,
1013 ext2_count_dirs(sb));
1014 }
1015 if (err) {
1016 printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1017 goto failed_mount3;
1018 }
1019 /*
1020 * set up enough so that it can read an inode
1021 */
1022 sb->s_op = &ext2_sops;
1023 sb->s_export_op = &ext2_export_ops;
1024 sb->s_xattr = ext2_xattr_handlers;
1025 root = iget(sb, EXT2_ROOT_INO);
1026 sb->s_root = d_alloc_root(root);
1027 if (!sb->s_root) {
1028 iput(root);
1029 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1030 goto failed_mount3;
1031 }
1032 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1033 dput(sb->s_root);
1034 sb->s_root = NULL;
1035 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1036 goto failed_mount3;
1037 }
1038 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1039 ext2_warning(sb, __FUNCTION__,
1040 "mounting ext3 filesystem as ext2");
1041 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1042 return 0;
1043
1044 cantfind_ext2:
1045 if (!silent)
1046 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1047 sb->s_id);
1048 goto failed_mount;
1049 failed_mount3:
1050 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1051 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1052 percpu_counter_destroy(&sbi->s_dirs_counter);
1053 failed_mount2:
1054 for (i = 0; i < db_count; i++)
1055 brelse(sbi->s_group_desc[i]);
1056 failed_mount_group_desc:
1057 kfree(sbi->s_group_desc);
1058 kfree(sbi->s_debts);
1059 failed_mount:
1060 brelse(bh);
1061 failed_sbi:
1062 sb->s_fs_info = NULL;
1063 kfree(sbi);
1064 return -EINVAL;
1065 }
1066
1067 static void ext2_commit_super (struct super_block * sb,
1068 struct ext2_super_block * es)
1069 {
1070 es->s_wtime = cpu_to_le32(get_seconds());
1071 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1072 sb->s_dirt = 0;
1073 }
1074
1075 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1076 {
1077 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1078 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1079 es->s_wtime = cpu_to_le32(get_seconds());
1080 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1081 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1082 sb->s_dirt = 0;
1083 }
1084
1085 /*
1086 * In the second extended file system, it is not necessary to
1087 * write the super block since we use a mapping of the
1088 * disk super block in a buffer.
1089 *
1090 * However, this function is still used to set the fs valid
1091 * flags to 0. We need to set this flag to 0 since the fs
1092 * may have been checked while mounted and e2fsck may have
1093 * set s_state to EXT2_VALID_FS after some corrections.
1094 */
1095
1096 void ext2_write_super (struct super_block * sb)
1097 {
1098 struct ext2_super_block * es;
1099 lock_kernel();
1100 if (!(sb->s_flags & MS_RDONLY)) {
1101 es = EXT2_SB(sb)->s_es;
1102
1103 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
1104 ext2_debug ("setting valid to 0\n");
1105 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
1106 ~EXT2_VALID_FS);
1107 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1108 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1109 es->s_mtime = cpu_to_le32(get_seconds());
1110 ext2_sync_super(sb, es);
1111 } else
1112 ext2_commit_super (sb, es);
1113 }
1114 sb->s_dirt = 0;
1115 unlock_kernel();
1116 }
1117
1118 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1119 {
1120 struct ext2_sb_info * sbi = EXT2_SB(sb);
1121 struct ext2_super_block * es;
1122 unsigned long old_mount_opt = sbi->s_mount_opt;
1123 struct ext2_mount_options old_opts;
1124 unsigned long old_sb_flags;
1125 int err;
1126
1127 /* Store the old options */
1128 old_sb_flags = sb->s_flags;
1129 old_opts.s_mount_opt = sbi->s_mount_opt;
1130 old_opts.s_resuid = sbi->s_resuid;
1131 old_opts.s_resgid = sbi->s_resgid;
1132
1133 /*
1134 * Allow the "check" option to be passed as a remount option.
1135 */
1136 if (!parse_options (data, sbi)) {
1137 err = -EINVAL;
1138 goto restore_opts;
1139 }
1140
1141 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1142 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1143
1144 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1145 EXT2_MOUNT_XIP if not */
1146
1147 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1148 printk("XIP: Unsupported blocksize\n");
1149 err = -EINVAL;
1150 goto restore_opts;
1151 }
1152
1153 es = sbi->s_es;
1154 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1155 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1156 invalidate_inodes(sb))
1157 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
1158 "xip remain in cache (no functional problem)");
1159 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1160 return 0;
1161 if (*flags & MS_RDONLY) {
1162 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1163 !(sbi->s_mount_state & EXT2_VALID_FS))
1164 return 0;
1165 /*
1166 * OK, we are remounting a valid rw partition rdonly, so set
1167 * the rdonly flag and then mark the partition as valid again.
1168 */
1169 es->s_state = cpu_to_le16(sbi->s_mount_state);
1170 es->s_mtime = cpu_to_le32(get_seconds());
1171 } else {
1172 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1173 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1174 if (ret) {
1175 printk("EXT2-fs: %s: couldn't remount RDWR because of "
1176 "unsupported optional features (%x).\n",
1177 sb->s_id, le32_to_cpu(ret));
1178 err = -EROFS;
1179 goto restore_opts;
1180 }
1181 /*
1182 * Mounting a RDONLY partition read-write, so reread and
1183 * store the current valid flag. (It may have been changed
1184 * by e2fsck since we originally mounted the partition.)
1185 */
1186 sbi->s_mount_state = le16_to_cpu(es->s_state);
1187 if (!ext2_setup_super (sb, es, 0))
1188 sb->s_flags &= ~MS_RDONLY;
1189 }
1190 ext2_sync_super(sb, es);
1191 return 0;
1192 restore_opts:
1193 sbi->s_mount_opt = old_opts.s_mount_opt;
1194 sbi->s_resuid = old_opts.s_resuid;
1195 sbi->s_resgid = old_opts.s_resgid;
1196 sb->s_flags = old_sb_flags;
1197 return err;
1198 }
1199
1200 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1201 {
1202 struct super_block *sb = dentry->d_sb;
1203 struct ext2_sb_info *sbi = EXT2_SB(sb);
1204 struct ext2_super_block *es = sbi->s_es;
1205 u64 fsid;
1206
1207 if (test_opt (sb, MINIX_DF))
1208 sbi->s_overhead_last = 0;
1209 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1210 unsigned long i, overhead = 0;
1211 smp_rmb();
1212
1213 /*
1214 * Compute the overhead (FS structures). This is constant
1215 * for a given filesystem unless the number of block groups
1216 * changes so we cache the previous value until it does.
1217 */
1218
1219 /*
1220 * All of the blocks before first_data_block are
1221 * overhead
1222 */
1223 overhead = le32_to_cpu(es->s_first_data_block);
1224
1225 /*
1226 * Add the overhead attributed to the superblock and
1227 * block group descriptors. If the sparse superblocks
1228 * feature is turned on, then not all groups have this.
1229 */
1230 for (i = 0; i < sbi->s_groups_count; i++)
1231 overhead += ext2_bg_has_super(sb, i) +
1232 ext2_bg_num_gdb(sb, i);
1233
1234 /*
1235 * Every block group has an inode bitmap, a block
1236 * bitmap, and an inode table.
1237 */
1238 overhead += (sbi->s_groups_count *
1239 (2 + sbi->s_itb_per_group));
1240 sbi->s_overhead_last = overhead;
1241 smp_wmb();
1242 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1243 }
1244
1245 buf->f_type = EXT2_SUPER_MAGIC;
1246 buf->f_bsize = sb->s_blocksize;
1247 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1248 buf->f_bfree = ext2_count_free_blocks(sb);
1249 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1250 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1251 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1252 buf->f_bavail = 0;
1253 buf->f_files = le32_to_cpu(es->s_inodes_count);
1254 buf->f_ffree = ext2_count_free_inodes(sb);
1255 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1256 buf->f_namelen = EXT2_NAME_LEN;
1257 fsid = le64_to_cpup((void *)es->s_uuid) ^
1258 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1259 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1260 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1261 return 0;
1262 }
1263
1264 static int ext2_get_sb(struct file_system_type *fs_type,
1265 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1266 {
1267 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1268 }
1269
1270 #ifdef CONFIG_QUOTA
1271
1272 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1273 * acquiring the locks... As quota files are never truncated and quota code
1274 * itself serializes the operations (and noone else should touch the files)
1275 * we don't have to be afraid of races */
1276 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1277 size_t len, loff_t off)
1278 {
1279 struct inode *inode = sb_dqopt(sb)->files[type];
1280 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1281 int err = 0;
1282 int offset = off & (sb->s_blocksize - 1);
1283 int tocopy;
1284 size_t toread;
1285 struct buffer_head tmp_bh;
1286 struct buffer_head *bh;
1287 loff_t i_size = i_size_read(inode);
1288
1289 if (off > i_size)
1290 return 0;
1291 if (off+len > i_size)
1292 len = i_size-off;
1293 toread = len;
1294 while (toread > 0) {
1295 tocopy = sb->s_blocksize - offset < toread ?
1296 sb->s_blocksize - offset : toread;
1297
1298 tmp_bh.b_state = 0;
1299 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1300 if (err < 0)
1301 return err;
1302 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1303 memset(data, 0, tocopy);
1304 else {
1305 bh = sb_bread(sb, tmp_bh.b_blocknr);
1306 if (!bh)
1307 return -EIO;
1308 memcpy(data, bh->b_data+offset, tocopy);
1309 brelse(bh);
1310 }
1311 offset = 0;
1312 toread -= tocopy;
1313 data += tocopy;
1314 blk++;
1315 }
1316 return len;
1317 }
1318
1319 /* Write to quotafile */
1320 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1321 const char *data, size_t len, loff_t off)
1322 {
1323 struct inode *inode = sb_dqopt(sb)->files[type];
1324 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1325 int err = 0;
1326 int offset = off & (sb->s_blocksize - 1);
1327 int tocopy;
1328 size_t towrite = len;
1329 struct buffer_head tmp_bh;
1330 struct buffer_head *bh;
1331
1332 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1333 while (towrite > 0) {
1334 tocopy = sb->s_blocksize - offset < towrite ?
1335 sb->s_blocksize - offset : towrite;
1336
1337 tmp_bh.b_state = 0;
1338 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1339 if (err < 0)
1340 goto out;
1341 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1342 bh = sb_bread(sb, tmp_bh.b_blocknr);
1343 else
1344 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1345 if (!bh) {
1346 err = -EIO;
1347 goto out;
1348 }
1349 lock_buffer(bh);
1350 memcpy(bh->b_data+offset, data, tocopy);
1351 flush_dcache_page(bh->b_page);
1352 set_buffer_uptodate(bh);
1353 mark_buffer_dirty(bh);
1354 unlock_buffer(bh);
1355 brelse(bh);
1356 offset = 0;
1357 towrite -= tocopy;
1358 data += tocopy;
1359 blk++;
1360 }
1361 out:
1362 if (len == towrite)
1363 return err;
1364 if (inode->i_size < off+len-towrite)
1365 i_size_write(inode, off+len-towrite);
1366 inode->i_version++;
1367 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1368 mark_inode_dirty(inode);
1369 mutex_unlock(&inode->i_mutex);
1370 return len - towrite;
1371 }
1372
1373 #endif
1374
1375 static struct file_system_type ext2_fs_type = {
1376 .owner = THIS_MODULE,
1377 .name = "ext2",
1378 .get_sb = ext2_get_sb,
1379 .kill_sb = kill_block_super,
1380 .fs_flags = FS_REQUIRES_DEV,
1381 };
1382
1383 static int __init init_ext2_fs(void)
1384 {
1385 int err = init_ext2_xattr();
1386 if (err)
1387 return err;
1388 err = init_inodecache();
1389 if (err)
1390 goto out1;
1391 err = register_filesystem(&ext2_fs_type);
1392 if (err)
1393 goto out;
1394 return 0;
1395 out:
1396 destroy_inodecache();
1397 out1:
1398 exit_ext2_xattr();
1399 return err;
1400 }
1401
1402 static void __exit exit_ext2_fs(void)
1403 {
1404 unregister_filesystem(&ext2_fs_type);
1405 destroy_inodecache();
1406 exit_ext2_xattr();
1407 }
1408
1409 module_init(init_ext2_fs)
1410 module_exit(exit_ext2_fs)
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