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Blackfin arch: Add Support for Peripheral PortMux and resouce allocation
[linux-2.6/openmoko-kernel.git] / fs / ext2 / super.c
blob5de5061eb331c811c9ed0c9baab5f75655c7ae99
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/smp_lock.h>
29 #include <linux/vfs.h>
30 #include <linux/seq_file.h>
31 #include <linux/mount.h>
32 #include <asm/uaccess.h>
33 #include "ext2.h"
34 #include "xattr.h"
35 #include "acl.h"
36 #include "xip.h"
37
38 static void ext2_sync_super(struct super_block *sb,
39 struct ext2_super_block *es);
40 static int ext2_remount (struct super_block * sb, int * flags, char * data);
41 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
42
43 void ext2_error (struct super_block * sb, const char * function,
44 const char * fmt, ...)
45 {
46 va_list args;
47 struct ext2_sb_info *sbi = EXT2_SB(sb);
48 struct ext2_super_block *es = sbi->s_es;
49
50 if (!(sb->s_flags & MS_RDONLY)) {
51 sbi->s_mount_state |= EXT2_ERROR_FS;
52 es->s_state =
53 cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
54 ext2_sync_super(sb, es);
55 }
56
57 va_start(args, fmt);
58 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
59 vprintk(fmt, args);
60 printk("\n");
61 va_end(args);
62
63 if (test_opt(sb, ERRORS_PANIC))
64 panic("EXT2-fs panic from previous error\n");
65 if (test_opt(sb, ERRORS_RO)) {
66 printk("Remounting filesystem read-only\n");
67 sb->s_flags |= MS_RDONLY;
68 }
69 }
70
71 void ext2_warning (struct super_block * sb, const char * function,
72 const char * fmt, ...)
73 {
74 va_list args;
75
76 va_start(args, fmt);
77 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
78 sb->s_id, function);
79 vprintk(fmt, args);
80 printk("\n");
81 va_end(args);
82 }
83
84 void ext2_update_dynamic_rev(struct super_block *sb)
85 {
86 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
87
88 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
89 return;
90
91 ext2_warning(sb, __FUNCTION__,
92 "updating to rev %d because of new feature flag, "
93 "running e2fsck is recommended",
94 EXT2_DYNAMIC_REV);
95
96 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
97 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
98 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
99 /* leave es->s_feature_*compat flags alone */
100 /* es->s_uuid will be set by e2fsck if empty */
101
102 /*
103 * The rest of the superblock fields should be zero, and if not it
104 * means they are likely already in use, so leave them alone. We
105 * can leave it up to e2fsck to clean up any inconsistencies there.
106 */
107 }
108
109 static void ext2_put_super (struct super_block * sb)
110 {
111 int db_count;
112 int i;
113 struct ext2_sb_info *sbi = EXT2_SB(sb);
114
115 ext2_xattr_put_super(sb);
116 if (!(sb->s_flags & MS_RDONLY)) {
117 struct ext2_super_block *es = sbi->s_es;
118
119 es->s_state = cpu_to_le16(sbi->s_mount_state);
120 ext2_sync_super(sb, es);
121 }
122 db_count = sbi->s_gdb_count;
123 for (i = 0; i < db_count; i++)
124 if (sbi->s_group_desc[i])
125 brelse (sbi->s_group_desc[i]);
126 kfree(sbi->s_group_desc);
127 kfree(sbi->s_debts);
128 percpu_counter_destroy(&sbi->s_freeblocks_counter);
129 percpu_counter_destroy(&sbi->s_freeinodes_counter);
130 percpu_counter_destroy(&sbi->s_dirs_counter);
131 brelse (sbi->s_sbh);
132 sb->s_fs_info = NULL;
133 kfree(sbi);
134
135 return;
136 }
137
138 static struct kmem_cache * ext2_inode_cachep;
139
140 static struct inode *ext2_alloc_inode(struct super_block *sb)
141 {
142 struct ext2_inode_info *ei;
143 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
144 if (!ei)
145 return NULL;
146 #ifdef CONFIG_EXT2_FS_POSIX_ACL
147 ei->i_acl = EXT2_ACL_NOT_CACHED;
148 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
149 #endif
150 ei->vfs_inode.i_version = 1;
151 return &ei->vfs_inode;
152 }
153
154 static void ext2_destroy_inode(struct inode *inode)
155 {
156 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
157 }
158
159 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
160 {
161 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
162
163 rwlock_init(&ei->i_meta_lock);
164 #ifdef CONFIG_EXT2_FS_XATTR
165 init_rwsem(&ei->xattr_sem);
166 #endif
167 inode_init_once(&ei->vfs_inode);
168 }
169
170 static int init_inodecache(void)
171 {
172 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
173 sizeof(struct ext2_inode_info),
174 0, (SLAB_RECLAIM_ACCOUNT|
175 SLAB_MEM_SPREAD),
176 init_once, NULL);
177 if (ext2_inode_cachep == NULL)
178 return -ENOMEM;
179 return 0;
180 }
181
182 static void destroy_inodecache(void)
183 {
184 kmem_cache_destroy(ext2_inode_cachep);
185 }
186
187 static void ext2_clear_inode(struct inode *inode)
188 {
189 #ifdef CONFIG_EXT2_FS_POSIX_ACL
190 struct ext2_inode_info *ei = EXT2_I(inode);
191
192 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
193 posix_acl_release(ei->i_acl);
194 ei->i_acl = EXT2_ACL_NOT_CACHED;
195 }
196 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
197 posix_acl_release(ei->i_default_acl);
198 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
199 }
200 #endif
201 }
202
203 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
204 {
205 struct ext2_sb_info *sbi = EXT2_SB(vfs->mnt_sb);
206
207 if (sbi->s_mount_opt & EXT2_MOUNT_GRPID)
208 seq_puts(seq, ",grpid");
209
210 #if defined(CONFIG_QUOTA)
211 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
212 seq_puts(seq, ",usrquota");
213
214 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
215 seq_puts(seq, ",grpquota");
216 #endif
217
218 #if defined(CONFIG_EXT2_FS_XIP)
219 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
220 seq_puts(seq, ",xip");
221 #endif
222
223 return 0;
224 }
225
226 #ifdef CONFIG_QUOTA
227 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
228 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
229 #endif
230
231 static const struct super_operations ext2_sops = {
232 .alloc_inode = ext2_alloc_inode,
233 .destroy_inode = ext2_destroy_inode,
234 .read_inode = ext2_read_inode,
235 .write_inode = ext2_write_inode,
236 .put_inode = ext2_put_inode,
237 .delete_inode = ext2_delete_inode,
238 .put_super = ext2_put_super,
239 .write_super = ext2_write_super,
240 .statfs = ext2_statfs,
241 .remount_fs = ext2_remount,
242 .clear_inode = ext2_clear_inode,
243 .show_options = ext2_show_options,
244 #ifdef CONFIG_QUOTA
245 .quota_read = ext2_quota_read,
246 .quota_write = ext2_quota_write,
247 #endif
248 };
249
250 static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp)
251 {
252 __u32 *objp = vobjp;
253 unsigned long ino = objp[0];
254 __u32 generation = objp[1];
255 struct inode *inode;
256 struct dentry *result;
257
258 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
259 return ERR_PTR(-ESTALE);
260 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
261 return ERR_PTR(-ESTALE);
262
263 /* iget isn't really right if the inode is currently unallocated!!
264 * ext2_read_inode currently does appropriate checks, but
265 * it might be "neater" to call ext2_get_inode first and check
266 * if the inode is valid.....
267 */
268 inode = iget(sb, ino);
269 if (inode == NULL)
270 return ERR_PTR(-ENOMEM);
271 if (is_bad_inode(inode) ||
272 (generation && inode->i_generation != generation)) {
273 /* we didn't find the right inode.. */
274 iput(inode);
275 return ERR_PTR(-ESTALE);
276 }
277 /* now to find a dentry.
278 * If possible, get a well-connected one
279 */
280 result = d_alloc_anon(inode);
281 if (!result) {
282 iput(inode);
283 return ERR_PTR(-ENOMEM);
284 }
285 return result;
286 }
287
288 /* Yes, most of these are left as NULL!!
289 * A NULL value implies the default, which works with ext2-like file
290 * systems, but can be improved upon.
291 * Currently only get_parent is required.
292 */
293 static struct export_operations ext2_export_ops = {
294 .get_parent = ext2_get_parent,
295 .get_dentry = ext2_get_dentry,
296 };
297
298 static unsigned long get_sb_block(void **data)
299 {
300 unsigned long sb_block;
301 char *options = (char *) *data;
302
303 if (!options || strncmp(options, "sb=", 3) != 0)
304 return 1; /* Default location */
305 options += 3;
306 sb_block = simple_strtoul(options, &options, 0);
307 if (*options && *options != ',') {
308 printk("EXT2-fs: Invalid sb specification: %s\n",
309 (char *) *data);
310 return 1;
311 }
312 if (*options == ',')
313 options++;
314 *data = (void *) options;
315 return sb_block;
316 }
317
318 enum {
319 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
320 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
321 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
322 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
323 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
324 Opt_usrquota, Opt_grpquota
325 };
326
327 static match_table_t tokens = {
328 {Opt_bsd_df, "bsddf"},
329 {Opt_minix_df, "minixdf"},
330 {Opt_grpid, "grpid"},
331 {Opt_grpid, "bsdgroups"},
332 {Opt_nogrpid, "nogrpid"},
333 {Opt_nogrpid, "sysvgroups"},
334 {Opt_resgid, "resgid=%u"},
335 {Opt_resuid, "resuid=%u"},
336 {Opt_sb, "sb=%u"},
337 {Opt_err_cont, "errors=continue"},
338 {Opt_err_panic, "errors=panic"},
339 {Opt_err_ro, "errors=remount-ro"},
340 {Opt_nouid32, "nouid32"},
341 {Opt_nocheck, "check=none"},
342 {Opt_nocheck, "nocheck"},
343 {Opt_debug, "debug"},
344 {Opt_oldalloc, "oldalloc"},
345 {Opt_orlov, "orlov"},
346 {Opt_nobh, "nobh"},
347 {Opt_user_xattr, "user_xattr"},
348 {Opt_nouser_xattr, "nouser_xattr"},
349 {Opt_acl, "acl"},
350 {Opt_noacl, "noacl"},
351 {Opt_xip, "xip"},
352 {Opt_grpquota, "grpquota"},
353 {Opt_ignore, "noquota"},
354 {Opt_quota, "quota"},
355 {Opt_usrquota, "usrquota"},
356 {Opt_err, NULL}
357 };
358
359 static int parse_options (char * options,
360 struct ext2_sb_info *sbi)
361 {
362 char * p;
363 substring_t args[MAX_OPT_ARGS];
364 int option;
365
366 if (!options)
367 return 1;
368
369 while ((p = strsep (&options, ",")) != NULL) {
370 int token;
371 if (!*p)
372 continue;
373
374 token = match_token(p, tokens, args);
375 switch (token) {
376 case Opt_bsd_df:
377 clear_opt (sbi->s_mount_opt, MINIX_DF);
378 break;
379 case Opt_minix_df:
380 set_opt (sbi->s_mount_opt, MINIX_DF);
381 break;
382 case Opt_grpid:
383 set_opt (sbi->s_mount_opt, GRPID);
384 break;
385 case Opt_nogrpid:
386 clear_opt (sbi->s_mount_opt, GRPID);
387 break;
388 case Opt_resuid:
389 if (match_int(&args[0], &option))
390 return 0;
391 sbi->s_resuid = option;
392 break;
393 case Opt_resgid:
394 if (match_int(&args[0], &option))
395 return 0;
396 sbi->s_resgid = option;
397 break;
398 case Opt_sb:
399 /* handled by get_sb_block() instead of here */
400 /* *sb_block = match_int(&args[0]); */
401 break;
402 case Opt_err_panic:
403 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
404 clear_opt (sbi->s_mount_opt, ERRORS_RO);
405 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
406 break;
407 case Opt_err_ro:
408 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
409 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
410 set_opt (sbi->s_mount_opt, ERRORS_RO);
411 break;
412 case Opt_err_cont:
413 clear_opt (sbi->s_mount_opt, ERRORS_RO);
414 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
415 set_opt (sbi->s_mount_opt, ERRORS_CONT);
416 break;
417 case Opt_nouid32:
418 set_opt (sbi->s_mount_opt, NO_UID32);
419 break;
420 case Opt_nocheck:
421 clear_opt (sbi->s_mount_opt, CHECK);
422 break;
423 case Opt_debug:
424 set_opt (sbi->s_mount_opt, DEBUG);
425 break;
426 case Opt_oldalloc:
427 set_opt (sbi->s_mount_opt, OLDALLOC);
428 break;
429 case Opt_orlov:
430 clear_opt (sbi->s_mount_opt, OLDALLOC);
431 break;
432 case Opt_nobh:
433 set_opt (sbi->s_mount_opt, NOBH);
434 break;
435 #ifdef CONFIG_EXT2_FS_XATTR
436 case Opt_user_xattr:
437 set_opt (sbi->s_mount_opt, XATTR_USER);
438 break;
439 case Opt_nouser_xattr:
440 clear_opt (sbi->s_mount_opt, XATTR_USER);
441 break;
442 #else
443 case Opt_user_xattr:
444 case Opt_nouser_xattr:
445 printk("EXT2 (no)user_xattr options not supported\n");
446 break;
447 #endif
448 #ifdef CONFIG_EXT2_FS_POSIX_ACL
449 case Opt_acl:
450 set_opt(sbi->s_mount_opt, POSIX_ACL);
451 break;
452 case Opt_noacl:
453 clear_opt(sbi->s_mount_opt, POSIX_ACL);
454 break;
455 #else
456 case Opt_acl:
457 case Opt_noacl:
458 printk("EXT2 (no)acl options not supported\n");
459 break;
460 #endif
461 case Opt_xip:
462 #ifdef CONFIG_EXT2_FS_XIP
463 set_opt (sbi->s_mount_opt, XIP);
464 #else
465 printk("EXT2 xip option not supported\n");
466 #endif
467 break;
468
469 #if defined(CONFIG_QUOTA)
470 case Opt_quota:
471 case Opt_usrquota:
472 set_opt(sbi->s_mount_opt, USRQUOTA);
473 break;
474
475 case Opt_grpquota:
476 set_opt(sbi->s_mount_opt, GRPQUOTA);
477 break;
478 #else
479 case Opt_quota:
480 case Opt_usrquota:
481 case Opt_grpquota:
482 printk(KERN_ERR
483 "EXT2-fs: quota operations not supported.\n");
484
485 break;
486 #endif
487
488 case Opt_ignore:
489 break;
490 default:
491 return 0;
492 }
493 }
494 return 1;
495 }
496
497 static int ext2_setup_super (struct super_block * sb,
498 struct ext2_super_block * es,
499 int read_only)
500 {
501 int res = 0;
502 struct ext2_sb_info *sbi = EXT2_SB(sb);
503
504 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
505 printk ("EXT2-fs warning: revision level too high, "
506 "forcing read-only mode\n");
507 res = MS_RDONLY;
508 }
509 if (read_only)
510 return res;
511 if (!(sbi->s_mount_state & EXT2_VALID_FS))
512 printk ("EXT2-fs warning: mounting unchecked fs, "
513 "running e2fsck is recommended\n");
514 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
515 printk ("EXT2-fs warning: mounting fs with errors, "
516 "running e2fsck is recommended\n");
517 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
518 le16_to_cpu(es->s_mnt_count) >=
519 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
520 printk ("EXT2-fs warning: maximal mount count reached, "
521 "running e2fsck is recommended\n");
522 else if (le32_to_cpu(es->s_checkinterval) &&
523 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
524 printk ("EXT2-fs warning: checktime reached, "
525 "running e2fsck is recommended\n");
526 if (!le16_to_cpu(es->s_max_mnt_count))
527 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
528 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
529 ext2_write_super(sb);
530 if (test_opt (sb, DEBUG))
531 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
532 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
533 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
534 sbi->s_frag_size,
535 sbi->s_groups_count,
536 EXT2_BLOCKS_PER_GROUP(sb),
537 EXT2_INODES_PER_GROUP(sb),
538 sbi->s_mount_opt);
539 return res;
540 }
541
542 static int ext2_check_descriptors (struct super_block * sb)
543 {
544 int i;
545 int desc_block = 0;
546 struct ext2_sb_info *sbi = EXT2_SB(sb);
547 unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
548 unsigned long last_block;
549 struct ext2_group_desc * gdp = NULL;
550
551 ext2_debug ("Checking group descriptors");
552
553 for (i = 0; i < sbi->s_groups_count; i++)
554 {
555 if (i == sbi->s_groups_count - 1)
556 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
557 else
558 last_block = first_block +
559 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
560
561 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
562 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
563 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
564 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
565 {
566 ext2_error (sb, "ext2_check_descriptors",
567 "Block bitmap for group %d"
568 " not in group (block %lu)!",
569 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
570 return 0;
571 }
572 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
573 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
574 {
575 ext2_error (sb, "ext2_check_descriptors",
576 "Inode bitmap for group %d"
577 " not in group (block %lu)!",
578 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
579 return 0;
580 }
581 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
582 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >
583 last_block)
584 {
585 ext2_error (sb, "ext2_check_descriptors",
586 "Inode table for group %d"
587 " not in group (block %lu)!",
588 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
589 return 0;
590 }
591 first_block += EXT2_BLOCKS_PER_GROUP(sb);
592 gdp++;
593 }
594 return 1;
595 }
596
597 /*
598 * Maximal file size. There is a direct, and {,double-,triple-}indirect
599 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
600 * We need to be 1 filesystem block less than the 2^32 sector limit.
601 */
602 static loff_t ext2_max_size(int bits)
603 {
604 loff_t res = EXT2_NDIR_BLOCKS;
605 /* This constant is calculated to be the largest file size for a
606 * dense, 4k-blocksize file such that the total number of
607 * sectors in the file, including data and all indirect blocks,
608 * does not exceed 2^32. */
609 const loff_t upper_limit = 0x1ff7fffd000LL;
610
611 res += 1LL << (bits-2);
612 res += 1LL << (2*(bits-2));
613 res += 1LL << (3*(bits-2));
614 res <<= bits;
615 if (res > upper_limit)
616 res = upper_limit;
617 return res;
618 }
619
620 static unsigned long descriptor_loc(struct super_block *sb,
621 unsigned long logic_sb_block,
622 int nr)
623 {
624 struct ext2_sb_info *sbi = EXT2_SB(sb);
625 unsigned long bg, first_data_block, first_meta_bg;
626 int has_super = 0;
627
628 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
629 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
630
631 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
632 nr < first_meta_bg)
633 return (logic_sb_block + nr + 1);
634 bg = sbi->s_desc_per_block * nr;
635 if (ext2_bg_has_super(sb, bg))
636 has_super = 1;
637 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
638 }
639
640 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
641 {
642 struct buffer_head * bh;
643 struct ext2_sb_info * sbi;
644 struct ext2_super_block * es;
645 struct inode *root;
646 unsigned long block;
647 unsigned long sb_block = get_sb_block(&data);
648 unsigned long logic_sb_block;
649 unsigned long offset = 0;
650 unsigned long def_mount_opts;
651 int blocksize = BLOCK_SIZE;
652 int db_count;
653 int i, j;
654 __le32 features;
655
656 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
657 if (!sbi)
658 return -ENOMEM;
659 sb->s_fs_info = sbi;
660
661 /*
662 * See what the current blocksize for the device is, and
663 * use that as the blocksize. Otherwise (or if the blocksize
664 * is smaller than the default) use the default.
665 * This is important for devices that have a hardware
666 * sectorsize that is larger than the default.
667 */
668 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
669 if (!blocksize) {
670 printk ("EXT2-fs: unable to set blocksize\n");
671 goto failed_sbi;
672 }
673
674 /*
675 * If the superblock doesn't start on a hardware sector boundary,
676 * calculate the offset.
677 */
678 if (blocksize != BLOCK_SIZE) {
679 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
680 offset = (sb_block*BLOCK_SIZE) % blocksize;
681 } else {
682 logic_sb_block = sb_block;
683 }
684
685 if (!(bh = sb_bread(sb, logic_sb_block))) {
686 printk ("EXT2-fs: unable to read superblock\n");
687 goto failed_sbi;
688 }
689 /*
690 * Note: s_es must be initialized as soon as possible because
691 * some ext2 macro-instructions depend on its value
692 */
693 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
694 sbi->s_es = es;
695 sb->s_magic = le16_to_cpu(es->s_magic);
696
697 if (sb->s_magic != EXT2_SUPER_MAGIC)
698 goto cantfind_ext2;
699
700 /* Set defaults before we parse the mount options */
701 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
702 if (def_mount_opts & EXT2_DEFM_DEBUG)
703 set_opt(sbi->s_mount_opt, DEBUG);
704 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
705 set_opt(sbi->s_mount_opt, GRPID);
706 if (def_mount_opts & EXT2_DEFM_UID16)
707 set_opt(sbi->s_mount_opt, NO_UID32);
708 #ifdef CONFIG_EXT2_FS_XATTR
709 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
710 set_opt(sbi->s_mount_opt, XATTR_USER);
711 #endif
712 #ifdef CONFIG_EXT2_FS_POSIX_ACL
713 if (def_mount_opts & EXT2_DEFM_ACL)
714 set_opt(sbi->s_mount_opt, POSIX_ACL);
715 #endif
716
717 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
718 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
719 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
720 set_opt(sbi->s_mount_opt, ERRORS_RO);
721 else
722 set_opt(sbi->s_mount_opt, ERRORS_CONT);
723
724 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
725 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
726
727 if (!parse_options ((char *) data, sbi))
728 goto failed_mount;
729
730 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
731 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
732 MS_POSIXACL : 0);
733
734 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
735 EXT2_MOUNT_XIP if not */
736
737 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
738 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
739 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
740 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
741 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
742 "running e2fsck is recommended\n");
743 /*
744 * Check feature flags regardless of the revision level, since we
745 * previously didn't change the revision level when setting the flags,
746 * so there is a chance incompat flags are set on a rev 0 filesystem.
747 */
748 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
749 if (features) {
750 printk("EXT2-fs: %s: couldn't mount because of "
751 "unsupported optional features (%x).\n",
752 sb->s_id, le32_to_cpu(features));
753 goto failed_mount;
754 }
755 if (!(sb->s_flags & MS_RDONLY) &&
756 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
757 printk("EXT2-fs: %s: couldn't mount RDWR because of "
758 "unsupported optional features (%x).\n",
759 sb->s_id, le32_to_cpu(features));
760 goto failed_mount;
761 }
762
763 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
764
765 if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) ||
766 (sb->s_blocksize != blocksize))) {
767 if (!silent)
768 printk("XIP: Unsupported blocksize\n");
769 goto failed_mount;
770 }
771
772 /* If the blocksize doesn't match, re-read the thing.. */
773 if (sb->s_blocksize != blocksize) {
774 brelse(bh);
775
776 if (!sb_set_blocksize(sb, blocksize)) {
777 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
778 goto failed_sbi;
779 }
780
781 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
782 offset = (sb_block*BLOCK_SIZE) % blocksize;
783 bh = sb_bread(sb, logic_sb_block);
784 if(!bh) {
785 printk("EXT2-fs: Couldn't read superblock on "
786 "2nd try.\n");
787 goto failed_sbi;
788 }
789 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
790 sbi->s_es = es;
791 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
792 printk ("EXT2-fs: Magic mismatch, very weird !\n");
793 goto failed_mount;
794 }
795 }
796
797 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
798
799 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
800 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
801 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
802 } else {
803 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
804 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
805 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
806 (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
807 (sbi->s_inode_size > blocksize)) {
808 printk ("EXT2-fs: unsupported inode size: %d\n",
809 sbi->s_inode_size);
810 goto failed_mount;
811 }
812 }
813
814 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
815 le32_to_cpu(es->s_log_frag_size);
816 if (sbi->s_frag_size == 0)
817 goto cantfind_ext2;
818 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
819
820 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
821 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
822 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
823
824 if (EXT2_INODE_SIZE(sb) == 0)
825 goto cantfind_ext2;
826 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
827 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
828 goto cantfind_ext2;
829 sbi->s_itb_per_group = sbi->s_inodes_per_group /
830 sbi->s_inodes_per_block;
831 sbi->s_desc_per_block = sb->s_blocksize /
832 sizeof (struct ext2_group_desc);
833 sbi->s_sbh = bh;
834 sbi->s_mount_state = le16_to_cpu(es->s_state);
835 sbi->s_addr_per_block_bits =
836 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
837 sbi->s_desc_per_block_bits =
838 ilog2 (EXT2_DESC_PER_BLOCK(sb));
839
840 if (sb->s_magic != EXT2_SUPER_MAGIC)
841 goto cantfind_ext2;
842
843 if (sb->s_blocksize != bh->b_size) {
844 if (!silent)
845 printk ("VFS: Unsupported blocksize on dev "
846 "%s.\n", sb->s_id);
847 goto failed_mount;
848 }
849
850 if (sb->s_blocksize != sbi->s_frag_size) {
851 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
852 sbi->s_frag_size, sb->s_blocksize);
853 goto failed_mount;
854 }
855
856 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
857 printk ("EXT2-fs: #blocks per group too big: %lu\n",
858 sbi->s_blocks_per_group);
859 goto failed_mount;
860 }
861 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
862 printk ("EXT2-fs: #fragments per group too big: %lu\n",
863 sbi->s_frags_per_group);
864 goto failed_mount;
865 }
866 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
867 printk ("EXT2-fs: #inodes per group too big: %lu\n",
868 sbi->s_inodes_per_group);
869 goto failed_mount;
870 }
871
872 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
873 goto cantfind_ext2;
874 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
875 le32_to_cpu(es->s_first_data_block) - 1)
876 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
877 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
878 EXT2_DESC_PER_BLOCK(sb);
879 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
880 if (sbi->s_group_desc == NULL) {
881 printk ("EXT2-fs: not enough memory\n");
882 goto failed_mount;
883 }
884 bgl_lock_init(&sbi->s_blockgroup_lock);
885 sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts),
886 GFP_KERNEL);
887 if (!sbi->s_debts) {
888 printk ("EXT2-fs: not enough memory\n");
889 goto failed_mount_group_desc;
890 }
891 memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts));
892 for (i = 0; i < db_count; i++) {
893 block = descriptor_loc(sb, logic_sb_block, i);
894 sbi->s_group_desc[i] = sb_bread(sb, block);
895 if (!sbi->s_group_desc[i]) {
896 for (j = 0; j < i; j++)
897 brelse (sbi->s_group_desc[j]);
898 printk ("EXT2-fs: unable to read group descriptors\n");
899 goto failed_mount_group_desc;
900 }
901 }
902 if (!ext2_check_descriptors (sb)) {
903 printk ("EXT2-fs: group descriptors corrupted!\n");
904 goto failed_mount2;
905 }
906 sbi->s_gdb_count = db_count;
907 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
908 spin_lock_init(&sbi->s_next_gen_lock);
909
910 percpu_counter_init(&sbi->s_freeblocks_counter,
911 ext2_count_free_blocks(sb));
912 percpu_counter_init(&sbi->s_freeinodes_counter,
913 ext2_count_free_inodes(sb));
914 percpu_counter_init(&sbi->s_dirs_counter,
915 ext2_count_dirs(sb));
916 /*
917 * set up enough so that it can read an inode
918 */
919 sb->s_op = &ext2_sops;
920 sb->s_export_op = &ext2_export_ops;
921 sb->s_xattr = ext2_xattr_handlers;
922 root = iget(sb, EXT2_ROOT_INO);
923 sb->s_root = d_alloc_root(root);
924 if (!sb->s_root) {
925 iput(root);
926 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
927 goto failed_mount3;
928 }
929 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
930 dput(sb->s_root);
931 sb->s_root = NULL;
932 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
933 goto failed_mount3;
934 }
935 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
936 ext2_warning(sb, __FUNCTION__,
937 "mounting ext3 filesystem as ext2");
938 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
939 return 0;
940
941 cantfind_ext2:
942 if (!silent)
943 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
944 sb->s_id);
945 goto failed_mount;
946 failed_mount3:
947 percpu_counter_destroy(&sbi->s_freeblocks_counter);
948 percpu_counter_destroy(&sbi->s_freeinodes_counter);
949 percpu_counter_destroy(&sbi->s_dirs_counter);
950 failed_mount2:
951 for (i = 0; i < db_count; i++)
952 brelse(sbi->s_group_desc[i]);
953 failed_mount_group_desc:
954 kfree(sbi->s_group_desc);
955 kfree(sbi->s_debts);
956 failed_mount:
957 brelse(bh);
958 failed_sbi:
959 sb->s_fs_info = NULL;
960 kfree(sbi);
961 return -EINVAL;
962 }
963
964 static void ext2_commit_super (struct super_block * sb,
965 struct ext2_super_block * es)
966 {
967 es->s_wtime = cpu_to_le32(get_seconds());
968 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
969 sb->s_dirt = 0;
970 }
971
972 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
973 {
974 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
975 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
976 es->s_wtime = cpu_to_le32(get_seconds());
977 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
978 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
979 sb->s_dirt = 0;
980 }
981
982 /*
983 * In the second extended file system, it is not necessary to
984 * write the super block since we use a mapping of the
985 * disk super block in a buffer.
986 *
987 * However, this function is still used to set the fs valid
988 * flags to 0. We need to set this flag to 0 since the fs
989 * may have been checked while mounted and e2fsck may have
990 * set s_state to EXT2_VALID_FS after some corrections.
991 */
992
993 void ext2_write_super (struct super_block * sb)
994 {
995 struct ext2_super_block * es;
996 lock_kernel();
997 if (!(sb->s_flags & MS_RDONLY)) {
998 es = EXT2_SB(sb)->s_es;
999
1000 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
1001 ext2_debug ("setting valid to 0\n");
1002 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
1003 ~EXT2_VALID_FS);
1004 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1005 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1006 es->s_mtime = cpu_to_le32(get_seconds());
1007 ext2_sync_super(sb, es);
1008 } else
1009 ext2_commit_super (sb, es);
1010 }
1011 sb->s_dirt = 0;
1012 unlock_kernel();
1013 }
1014
1015 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1016 {
1017 struct ext2_sb_info * sbi = EXT2_SB(sb);
1018 struct ext2_super_block * es;
1019 unsigned long old_mount_opt = sbi->s_mount_opt;
1020 struct ext2_mount_options old_opts;
1021 unsigned long old_sb_flags;
1022 int err;
1023
1024 /* Store the old options */
1025 old_sb_flags = sb->s_flags;
1026 old_opts.s_mount_opt = sbi->s_mount_opt;
1027 old_opts.s_resuid = sbi->s_resuid;
1028 old_opts.s_resgid = sbi->s_resgid;
1029
1030 /*
1031 * Allow the "check" option to be passed as a remount option.
1032 */
1033 if (!parse_options (data, sbi)) {
1034 err = -EINVAL;
1035 goto restore_opts;
1036 }
1037
1038 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1039 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1040
1041 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1042 EXT2_MOUNT_XIP if not */
1043
1044 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1045 printk("XIP: Unsupported blocksize\n");
1046 err = -EINVAL;
1047 goto restore_opts;
1048 }
1049
1050 es = sbi->s_es;
1051 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1052 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1053 invalidate_inodes(sb))
1054 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
1055 "xip remain in cache (no functional problem)");
1056 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1057 return 0;
1058 if (*flags & MS_RDONLY) {
1059 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1060 !(sbi->s_mount_state & EXT2_VALID_FS))
1061 return 0;
1062 /*
1063 * OK, we are remounting a valid rw partition rdonly, so set
1064 * the rdonly flag and then mark the partition as valid again.
1065 */
1066 es->s_state = cpu_to_le16(sbi->s_mount_state);
1067 es->s_mtime = cpu_to_le32(get_seconds());
1068 } else {
1069 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1070 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1071 if (ret) {
1072 printk("EXT2-fs: %s: couldn't remount RDWR because of "
1073 "unsupported optional features (%x).\n",
1074 sb->s_id, le32_to_cpu(ret));
1075 err = -EROFS;
1076 goto restore_opts;
1077 }
1078 /*
1079 * Mounting a RDONLY partition read-write, so reread and
1080 * store the current valid flag. (It may have been changed
1081 * by e2fsck since we originally mounted the partition.)
1082 */
1083 sbi->s_mount_state = le16_to_cpu(es->s_state);
1084 if (!ext2_setup_super (sb, es, 0))
1085 sb->s_flags &= ~MS_RDONLY;
1086 }
1087 ext2_sync_super(sb, es);
1088 return 0;
1089 restore_opts:
1090 sbi->s_mount_opt = old_opts.s_mount_opt;
1091 sbi->s_resuid = old_opts.s_resuid;
1092 sbi->s_resgid = old_opts.s_resgid;
1093 sb->s_flags = old_sb_flags;
1094 return err;
1095 }
1096
1097 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1098 {
1099 struct super_block *sb = dentry->d_sb;
1100 struct ext2_sb_info *sbi = EXT2_SB(sb);
1101 struct ext2_super_block *es = sbi->s_es;
1102 unsigned long overhead;
1103 int i;
1104 u64 fsid;
1105
1106 if (test_opt (sb, MINIX_DF))
1107 overhead = 0;
1108 else {
1109 /*
1110 * Compute the overhead (FS structures)
1111 */
1112
1113 /*
1114 * All of the blocks before first_data_block are
1115 * overhead
1116 */
1117 overhead = le32_to_cpu(es->s_first_data_block);
1118
1119 /*
1120 * Add the overhead attributed to the superblock and
1121 * block group descriptors. If the sparse superblocks
1122 * feature is turned on, then not all groups have this.
1123 */
1124 for (i = 0; i < sbi->s_groups_count; i++)
1125 overhead += ext2_bg_has_super(sb, i) +
1126 ext2_bg_num_gdb(sb, i);
1127
1128 /*
1129 * Every block group has an inode bitmap, a block
1130 * bitmap, and an inode table.
1131 */
1132 overhead += (sbi->s_groups_count *
1133 (2 + sbi->s_itb_per_group));
1134 }
1135
1136 buf->f_type = EXT2_SUPER_MAGIC;
1137 buf->f_bsize = sb->s_blocksize;
1138 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - overhead;
1139 buf->f_bfree = ext2_count_free_blocks(sb);
1140 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1141 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1142 buf->f_bavail = 0;
1143 buf->f_files = le32_to_cpu(es->s_inodes_count);
1144 buf->f_ffree = ext2_count_free_inodes(sb);
1145 buf->f_namelen = EXT2_NAME_LEN;
1146 fsid = le64_to_cpup((void *)es->s_uuid) ^
1147 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1148 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1149 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1150 return 0;
1151 }
1152
1153 static int ext2_get_sb(struct file_system_type *fs_type,
1154 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1155 {
1156 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1157 }
1158
1159 #ifdef CONFIG_QUOTA
1160
1161 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1162 * acquiring the locks... As quota files are never truncated and quota code
1163 * itself serializes the operations (and noone else should touch the files)
1164 * we don't have to be afraid of races */
1165 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1166 size_t len, loff_t off)
1167 {
1168 struct inode *inode = sb_dqopt(sb)->files[type];
1169 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1170 int err = 0;
1171 int offset = off & (sb->s_blocksize - 1);
1172 int tocopy;
1173 size_t toread;
1174 struct buffer_head tmp_bh;
1175 struct buffer_head *bh;
1176 loff_t i_size = i_size_read(inode);
1177
1178 if (off > i_size)
1179 return 0;
1180 if (off+len > i_size)
1181 len = i_size-off;
1182 toread = len;
1183 while (toread > 0) {
1184 tocopy = sb->s_blocksize - offset < toread ?
1185 sb->s_blocksize - offset : toread;
1186
1187 tmp_bh.b_state = 0;
1188 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1189 if (err)
1190 return err;
1191 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1192 memset(data, 0, tocopy);
1193 else {
1194 bh = sb_bread(sb, tmp_bh.b_blocknr);
1195 if (!bh)
1196 return -EIO;
1197 memcpy(data, bh->b_data+offset, tocopy);
1198 brelse(bh);
1199 }
1200 offset = 0;
1201 toread -= tocopy;
1202 data += tocopy;
1203 blk++;
1204 }
1205 return len;
1206 }
1207
1208 /* Write to quotafile */
1209 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1210 const char *data, size_t len, loff_t off)
1211 {
1212 struct inode *inode = sb_dqopt(sb)->files[type];
1213 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1214 int err = 0;
1215 int offset = off & (sb->s_blocksize - 1);
1216 int tocopy;
1217 size_t towrite = len;
1218 struct buffer_head tmp_bh;
1219 struct buffer_head *bh;
1220
1221 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1222 while (towrite > 0) {
1223 tocopy = sb->s_blocksize - offset < towrite ?
1224 sb->s_blocksize - offset : towrite;
1225
1226 tmp_bh.b_state = 0;
1227 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1228 if (err)
1229 goto out;
1230 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1231 bh = sb_bread(sb, tmp_bh.b_blocknr);
1232 else
1233 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1234 if (!bh) {
1235 err = -EIO;
1236 goto out;
1237 }
1238 lock_buffer(bh);
1239 memcpy(bh->b_data+offset, data, tocopy);
1240 flush_dcache_page(bh->b_page);
1241 set_buffer_uptodate(bh);
1242 mark_buffer_dirty(bh);
1243 unlock_buffer(bh);
1244 brelse(bh);
1245 offset = 0;
1246 towrite -= tocopy;
1247 data += tocopy;
1248 blk++;
1249 }
1250 out:
1251 if (len == towrite)
1252 return err;
1253 if (inode->i_size < off+len-towrite)
1254 i_size_write(inode, off+len-towrite);
1255 inode->i_version++;
1256 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1257 mark_inode_dirty(inode);
1258 mutex_unlock(&inode->i_mutex);
1259 return len - towrite;
1260 }
1261
1262 #endif
1263
1264 static struct file_system_type ext2_fs_type = {
1265 .owner = THIS_MODULE,
1266 .name = "ext2",
1267 .get_sb = ext2_get_sb,
1268 .kill_sb = kill_block_super,
1269 .fs_flags = FS_REQUIRES_DEV,
1270 };
1271
1272 static int __init init_ext2_fs(void)
1273 {
1274 int err = init_ext2_xattr();
1275 if (err)
1276 return err;
1277 err = init_inodecache();
1278 if (err)
1279 goto out1;
1280 err = register_filesystem(&ext2_fs_type);
1281 if (err)
1282 goto out;
1283 return 0;
1284 out:
1285 destroy_inodecache();
1286 out1:
1287 exit_ext2_xattr();
1288 return err;
1289 }
1290
1291 static void __exit exit_ext2_fs(void)
1292 {
1293 unregister_filesystem(&ext2_fs_type);
1294 destroy_inodecache();
1295 exit_ext2_xattr();
1296 }
1297
1298 module_init(init_ext2_fs)
1299 module_exit(exit_ext2_fs)
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