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[mirror_ubuntu-zesty-kernel.git] / fs / ext2 / super.c
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 kmem_cache_t * 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, SLAB_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, kmem_cache_t * cachep, unsigned long flags)
160 {
161 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
162
163 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
164 SLAB_CTOR_CONSTRUCTOR) {
165 rwlock_init(&ei->i_meta_lock);
166 #ifdef CONFIG_EXT2_FS_XATTR
167 init_rwsem(&ei->xattr_sem);
168 #endif
169 inode_init_once(&ei->vfs_inode);
170 }
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, NULL);
180 if (ext2_inode_cachep == NULL)
181 return -ENOMEM;
182 return 0;
183 }
184
185 static void destroy_inodecache(void)
186 {
187 if (kmem_cache_destroy(ext2_inode_cachep))
188 printk(KERN_INFO "ext2_inode_cache: not all structures were freed\n");
189 }
190
191 static void ext2_clear_inode(struct inode *inode)
192 {
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 }
206
207 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
208 {
209 struct ext2_sb_info *sbi = EXT2_SB(vfs->mnt_sb);
210
211 if (sbi->s_mount_opt & EXT2_MOUNT_GRPID)
212 seq_puts(seq, ",grpid");
213
214 #if defined(CONFIG_QUOTA)
215 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
216 seq_puts(seq, ",usrquota");
217
218 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
219 seq_puts(seq, ",grpquota");
220 #endif
221
222 #if defined(CONFIG_EXT2_FS_XIP)
223 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
224 seq_puts(seq, ",xip");
225 #endif
226
227 return 0;
228 }
229
230 #ifdef CONFIG_QUOTA
231 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
232 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
233 #endif
234
235 static struct super_operations ext2_sops = {
236 .alloc_inode = ext2_alloc_inode,
237 .destroy_inode = ext2_destroy_inode,
238 .read_inode = ext2_read_inode,
239 .write_inode = ext2_write_inode,
240 .put_inode = ext2_put_inode,
241 .delete_inode = ext2_delete_inode,
242 .put_super = ext2_put_super,
243 .write_super = ext2_write_super,
244 .statfs = ext2_statfs,
245 .remount_fs = ext2_remount,
246 .clear_inode = ext2_clear_inode,
247 .show_options = ext2_show_options,
248 #ifdef CONFIG_QUOTA
249 .quota_read = ext2_quota_read,
250 .quota_write = ext2_quota_write,
251 #endif
252 };
253
254 static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp)
255 {
256 __u32 *objp = vobjp;
257 unsigned long ino = objp[0];
258 __u32 generation = objp[1];
259 struct inode *inode;
260 struct dentry *result;
261
262 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
263 return ERR_PTR(-ESTALE);
264 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
265 return ERR_PTR(-ESTALE);
266
267 /* iget isn't really right if the inode is currently unallocated!!
268 * ext2_read_inode currently does appropriate checks, but
269 * it might be "neater" to call ext2_get_inode first and check
270 * if the inode is valid.....
271 */
272 inode = iget(sb, ino);
273 if (inode == NULL)
274 return ERR_PTR(-ENOMEM);
275 if (is_bad_inode(inode) ||
276 (generation && inode->i_generation != generation)) {
277 /* we didn't find the right inode.. */
278 iput(inode);
279 return ERR_PTR(-ESTALE);
280 }
281 /* now to find a dentry.
282 * If possible, get a well-connected one
283 */
284 result = d_alloc_anon(inode);
285 if (!result) {
286 iput(inode);
287 return ERR_PTR(-ENOMEM);
288 }
289 return result;
290 }
291
292 /* Yes, most of these are left as NULL!!
293 * A NULL value implies the default, which works with ext2-like file
294 * systems, but can be improved upon.
295 * Currently only get_parent is required.
296 */
297 static struct export_operations ext2_export_ops = {
298 .get_parent = ext2_get_parent,
299 .get_dentry = ext2_get_dentry,
300 };
301
302 static unsigned long get_sb_block(void **data)
303 {
304 unsigned long sb_block;
305 char *options = (char *) *data;
306
307 if (!options || strncmp(options, "sb=", 3) != 0)
308 return 1; /* Default location */
309 options += 3;
310 sb_block = simple_strtoul(options, &options, 0);
311 if (*options && *options != ',') {
312 printk("EXT2-fs: Invalid sb specification: %s\n",
313 (char *) *data);
314 return 1;
315 }
316 if (*options == ',')
317 options++;
318 *data = (void *) options;
319 return sb_block;
320 }
321
322 enum {
323 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
324 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
325 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
326 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
327 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
328 Opt_usrquota, Opt_grpquota
329 };
330
331 static match_table_t tokens = {
332 {Opt_bsd_df, "bsddf"},
333 {Opt_minix_df, "minixdf"},
334 {Opt_grpid, "grpid"},
335 {Opt_grpid, "bsdgroups"},
336 {Opt_nogrpid, "nogrpid"},
337 {Opt_nogrpid, "sysvgroups"},
338 {Opt_resgid, "resgid=%u"},
339 {Opt_resuid, "resuid=%u"},
340 {Opt_sb, "sb=%u"},
341 {Opt_err_cont, "errors=continue"},
342 {Opt_err_panic, "errors=panic"},
343 {Opt_err_ro, "errors=remount-ro"},
344 {Opt_nouid32, "nouid32"},
345 {Opt_nocheck, "check=none"},
346 {Opt_nocheck, "nocheck"},
347 {Opt_debug, "debug"},
348 {Opt_oldalloc, "oldalloc"},
349 {Opt_orlov, "orlov"},
350 {Opt_nobh, "nobh"},
351 {Opt_user_xattr, "user_xattr"},
352 {Opt_nouser_xattr, "nouser_xattr"},
353 {Opt_acl, "acl"},
354 {Opt_noacl, "noacl"},
355 {Opt_xip, "xip"},
356 {Opt_grpquota, "grpquota"},
357 {Opt_ignore, "noquota"},
358 {Opt_quota, "quota"},
359 {Opt_usrquota, "usrquota"},
360 {Opt_err, NULL}
361 };
362
363 static int parse_options (char * options,
364 struct ext2_sb_info *sbi)
365 {
366 char * p;
367 substring_t args[MAX_OPT_ARGS];
368 unsigned long kind = EXT2_MOUNT_ERRORS_CONT;
369 int option;
370
371 if (!options)
372 return 1;
373
374 while ((p = strsep (&options, ",")) != NULL) {
375 int token;
376 if (!*p)
377 continue;
378
379 token = match_token(p, tokens, args);
380 switch (token) {
381 case Opt_bsd_df:
382 clear_opt (sbi->s_mount_opt, MINIX_DF);
383 break;
384 case Opt_minix_df:
385 set_opt (sbi->s_mount_opt, MINIX_DF);
386 break;
387 case Opt_grpid:
388 set_opt (sbi->s_mount_opt, GRPID);
389 break;
390 case Opt_nogrpid:
391 clear_opt (sbi->s_mount_opt, GRPID);
392 break;
393 case Opt_resuid:
394 if (match_int(&args[0], &option))
395 return 0;
396 sbi->s_resuid = option;
397 break;
398 case Opt_resgid:
399 if (match_int(&args[0], &option))
400 return 0;
401 sbi->s_resgid = option;
402 break;
403 case Opt_sb:
404 /* handled by get_sb_block() instead of here */
405 /* *sb_block = match_int(&args[0]); */
406 break;
407 case Opt_err_panic:
408 kind = EXT2_MOUNT_ERRORS_PANIC;
409 break;
410 case Opt_err_ro:
411 kind = EXT2_MOUNT_ERRORS_RO;
412 break;
413 case Opt_err_cont:
414 kind = EXT2_MOUNT_ERRORS_CONT;
415 break;
416 case Opt_nouid32:
417 set_opt (sbi->s_mount_opt, NO_UID32);
418 break;
419 case Opt_nocheck:
420 clear_opt (sbi->s_mount_opt, CHECK);
421 break;
422 case Opt_debug:
423 set_opt (sbi->s_mount_opt, DEBUG);
424 break;
425 case Opt_oldalloc:
426 set_opt (sbi->s_mount_opt, OLDALLOC);
427 break;
428 case Opt_orlov:
429 clear_opt (sbi->s_mount_opt, OLDALLOC);
430 break;
431 case Opt_nobh:
432 set_opt (sbi->s_mount_opt, NOBH);
433 break;
434 #ifdef CONFIG_EXT2_FS_XATTR
435 case Opt_user_xattr:
436 set_opt (sbi->s_mount_opt, XATTR_USER);
437 break;
438 case Opt_nouser_xattr:
439 clear_opt (sbi->s_mount_opt, XATTR_USER);
440 break;
441 #else
442 case Opt_user_xattr:
443 case Opt_nouser_xattr:
444 printk("EXT2 (no)user_xattr options not supported\n");
445 break;
446 #endif
447 #ifdef CONFIG_EXT2_FS_POSIX_ACL
448 case Opt_acl:
449 set_opt(sbi->s_mount_opt, POSIX_ACL);
450 break;
451 case Opt_noacl:
452 clear_opt(sbi->s_mount_opt, POSIX_ACL);
453 break;
454 #else
455 case Opt_acl:
456 case Opt_noacl:
457 printk("EXT2 (no)acl options not supported\n");
458 break;
459 #endif
460 case Opt_xip:
461 #ifdef CONFIG_EXT2_FS_XIP
462 set_opt (sbi->s_mount_opt, XIP);
463 #else
464 printk("EXT2 xip option not supported\n");
465 #endif
466 break;
467
468 #if defined(CONFIG_QUOTA)
469 case Opt_quota:
470 case Opt_usrquota:
471 set_opt(sbi->s_mount_opt, USRQUOTA);
472 break;
473
474 case Opt_grpquota:
475 set_opt(sbi->s_mount_opt, GRPQUOTA);
476 break;
477 #else
478 case Opt_quota:
479 case Opt_usrquota:
480 case Opt_grpquota:
481 printk(KERN_ERR
482 "EXT2-fs: quota operations not supported.\n");
483
484 break;
485 #endif
486
487 case Opt_ignore:
488 break;
489 default:
490 return 0;
491 }
492 }
493 sbi->s_mount_opt |= kind;
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 block = le32_to_cpu(sbi->s_es->s_first_data_block);
548 struct ext2_group_desc * gdp = NULL;
549
550 ext2_debug ("Checking group descriptors");
551
552 for (i = 0; i < sbi->s_groups_count; i++)
553 {
554 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
555 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
556 if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
557 le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
558 {
559 ext2_error (sb, "ext2_check_descriptors",
560 "Block bitmap for group %d"
561 " not in group (block %lu)!",
562 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
563 return 0;
564 }
565 if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
566 le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
567 {
568 ext2_error (sb, "ext2_check_descriptors",
569 "Inode bitmap for group %d"
570 " not in group (block %lu)!",
571 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
572 return 0;
573 }
574 if (le32_to_cpu(gdp->bg_inode_table) < block ||
575 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
576 block + EXT2_BLOCKS_PER_GROUP(sb))
577 {
578 ext2_error (sb, "ext2_check_descriptors",
579 "Inode table for group %d"
580 " not in group (block %lu)!",
581 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
582 return 0;
583 }
584 block += EXT2_BLOCKS_PER_GROUP(sb);
585 gdp++;
586 }
587 return 1;
588 }
589
590 #define log2(n) ffz(~(n))
591
592 /*
593 * Maximal file size. There is a direct, and {,double-,triple-}indirect
594 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
595 * We need to be 1 filesystem block less than the 2^32 sector limit.
596 */
597 static loff_t ext2_max_size(int bits)
598 {
599 loff_t res = EXT2_NDIR_BLOCKS;
600 /* This constant is calculated to be the largest file size for a
601 * dense, 4k-blocksize file such that the total number of
602 * sectors in the file, including data and all indirect blocks,
603 * does not exceed 2^32. */
604 const loff_t upper_limit = 0x1ff7fffd000LL;
605
606 res += 1LL << (bits-2);
607 res += 1LL << (2*(bits-2));
608 res += 1LL << (3*(bits-2));
609 res <<= bits;
610 if (res > upper_limit)
611 res = upper_limit;
612 return res;
613 }
614
615 static unsigned long descriptor_loc(struct super_block *sb,
616 unsigned long logic_sb_block,
617 int nr)
618 {
619 struct ext2_sb_info *sbi = EXT2_SB(sb);
620 unsigned long bg, first_data_block, first_meta_bg;
621 int has_super = 0;
622
623 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
624 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
625
626 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
627 nr < first_meta_bg)
628 return (logic_sb_block + nr + 1);
629 bg = sbi->s_desc_per_block * nr;
630 if (ext2_bg_has_super(sb, bg))
631 has_super = 1;
632 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
633 }
634
635 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
636 {
637 struct buffer_head * bh;
638 struct ext2_sb_info * sbi;
639 struct ext2_super_block * es;
640 struct inode *root;
641 unsigned long block;
642 unsigned long sb_block = get_sb_block(&data);
643 unsigned long logic_sb_block;
644 unsigned long offset = 0;
645 unsigned long def_mount_opts;
646 int blocksize = BLOCK_SIZE;
647 int db_count;
648 int i, j;
649 __le32 features;
650
651 sbi = kmalloc(sizeof(*sbi), GFP_KERNEL);
652 if (!sbi)
653 return -ENOMEM;
654 sb->s_fs_info = sbi;
655 memset(sbi, 0, sizeof(*sbi));
656
657 /*
658 * See what the current blocksize for the device is, and
659 * use that as the blocksize. Otherwise (or if the blocksize
660 * is smaller than the default) use the default.
661 * This is important for devices that have a hardware
662 * sectorsize that is larger than the default.
663 */
664 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
665 if (!blocksize) {
666 printk ("EXT2-fs: unable to set blocksize\n");
667 goto failed_sbi;
668 }
669
670 /*
671 * If the superblock doesn't start on a hardware sector boundary,
672 * calculate the offset.
673 */
674 if (blocksize != BLOCK_SIZE) {
675 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
676 offset = (sb_block*BLOCK_SIZE) % blocksize;
677 } else {
678 logic_sb_block = sb_block;
679 }
680
681 if (!(bh = sb_bread(sb, logic_sb_block))) {
682 printk ("EXT2-fs: unable to read superblock\n");
683 goto failed_sbi;
684 }
685 /*
686 * Note: s_es must be initialized as soon as possible because
687 * some ext2 macro-instructions depend on its value
688 */
689 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
690 sbi->s_es = es;
691 sb->s_magic = le16_to_cpu(es->s_magic);
692
693 if (sb->s_magic != EXT2_SUPER_MAGIC)
694 goto cantfind_ext2;
695
696 /* Set defaults before we parse the mount options */
697 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
698 if (def_mount_opts & EXT2_DEFM_DEBUG)
699 set_opt(sbi->s_mount_opt, DEBUG);
700 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
701 set_opt(sbi->s_mount_opt, GRPID);
702 if (def_mount_opts & EXT2_DEFM_UID16)
703 set_opt(sbi->s_mount_opt, NO_UID32);
704 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
705 set_opt(sbi->s_mount_opt, XATTR_USER);
706 if (def_mount_opts & EXT2_DEFM_ACL)
707 set_opt(sbi->s_mount_opt, POSIX_ACL);
708
709 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
710 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
711 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
712 set_opt(sbi->s_mount_opt, ERRORS_RO);
713
714 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
715 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
716
717 if (!parse_options ((char *) data, sbi))
718 goto failed_mount;
719
720 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
721 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
722 MS_POSIXACL : 0);
723
724 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
725 EXT2_MOUNT_XIP if not */
726
727 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
728 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
729 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
730 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
731 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
732 "running e2fsck is recommended\n");
733 /*
734 * Check feature flags regardless of the revision level, since we
735 * previously didn't change the revision level when setting the flags,
736 * so there is a chance incompat flags are set on a rev 0 filesystem.
737 */
738 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
739 if (features) {
740 printk("EXT2-fs: %s: couldn't mount because of "
741 "unsupported optional features (%x).\n",
742 sb->s_id, le32_to_cpu(features));
743 goto failed_mount;
744 }
745 if (!(sb->s_flags & MS_RDONLY) &&
746 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
747 printk("EXT2-fs: %s: couldn't mount RDWR because of "
748 "unsupported optional features (%x).\n",
749 sb->s_id, le32_to_cpu(features));
750 goto failed_mount;
751 }
752
753 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
754
755 if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) ||
756 (sb->s_blocksize != blocksize))) {
757 if (!silent)
758 printk("XIP: Unsupported blocksize\n");
759 goto failed_mount;
760 }
761
762 /* If the blocksize doesn't match, re-read the thing.. */
763 if (sb->s_blocksize != blocksize) {
764 brelse(bh);
765
766 if (!sb_set_blocksize(sb, blocksize)) {
767 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
768 goto failed_sbi;
769 }
770
771 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
772 offset = (sb_block*BLOCK_SIZE) % blocksize;
773 bh = sb_bread(sb, logic_sb_block);
774 if(!bh) {
775 printk("EXT2-fs: Couldn't read superblock on "
776 "2nd try.\n");
777 goto failed_sbi;
778 }
779 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
780 sbi->s_es = es;
781 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
782 printk ("EXT2-fs: Magic mismatch, very weird !\n");
783 goto failed_mount;
784 }
785 }
786
787 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
788
789 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
790 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
791 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
792 } else {
793 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
794 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
795 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
796 (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
797 (sbi->s_inode_size > blocksize)) {
798 printk ("EXT2-fs: unsupported inode size: %d\n",
799 sbi->s_inode_size);
800 goto failed_mount;
801 }
802 }
803
804 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
805 le32_to_cpu(es->s_log_frag_size);
806 if (sbi->s_frag_size == 0)
807 goto cantfind_ext2;
808 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
809
810 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
811 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
812 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
813
814 if (EXT2_INODE_SIZE(sb) == 0)
815 goto cantfind_ext2;
816 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
817 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
818 goto cantfind_ext2;
819 sbi->s_itb_per_group = sbi->s_inodes_per_group /
820 sbi->s_inodes_per_block;
821 sbi->s_desc_per_block = sb->s_blocksize /
822 sizeof (struct ext2_group_desc);
823 sbi->s_sbh = bh;
824 sbi->s_mount_state = le16_to_cpu(es->s_state);
825 sbi->s_addr_per_block_bits =
826 log2 (EXT2_ADDR_PER_BLOCK(sb));
827 sbi->s_desc_per_block_bits =
828 log2 (EXT2_DESC_PER_BLOCK(sb));
829
830 if (sb->s_magic != EXT2_SUPER_MAGIC)
831 goto cantfind_ext2;
832
833 if (sb->s_blocksize != bh->b_size) {
834 if (!silent)
835 printk ("VFS: Unsupported blocksize on dev "
836 "%s.\n", sb->s_id);
837 goto failed_mount;
838 }
839
840 if (sb->s_blocksize != sbi->s_frag_size) {
841 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
842 sbi->s_frag_size, sb->s_blocksize);
843 goto failed_mount;
844 }
845
846 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
847 printk ("EXT2-fs: #blocks per group too big: %lu\n",
848 sbi->s_blocks_per_group);
849 goto failed_mount;
850 }
851 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
852 printk ("EXT2-fs: #fragments per group too big: %lu\n",
853 sbi->s_frags_per_group);
854 goto failed_mount;
855 }
856 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
857 printk ("EXT2-fs: #inodes per group too big: %lu\n",
858 sbi->s_inodes_per_group);
859 goto failed_mount;
860 }
861
862 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
863 goto cantfind_ext2;
864 sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
865 le32_to_cpu(es->s_first_data_block) +
866 EXT2_BLOCKS_PER_GROUP(sb) - 1) /
867 EXT2_BLOCKS_PER_GROUP(sb);
868 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
869 EXT2_DESC_PER_BLOCK(sb);
870 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
871 if (sbi->s_group_desc == NULL) {
872 printk ("EXT2-fs: not enough memory\n");
873 goto failed_mount;
874 }
875 bgl_lock_init(&sbi->s_blockgroup_lock);
876 sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts),
877 GFP_KERNEL);
878 if (!sbi->s_debts) {
879 printk ("EXT2-fs: not enough memory\n");
880 goto failed_mount_group_desc;
881 }
882 memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts));
883 for (i = 0; i < db_count; i++) {
884 block = descriptor_loc(sb, logic_sb_block, i);
885 sbi->s_group_desc[i] = sb_bread(sb, block);
886 if (!sbi->s_group_desc[i]) {
887 for (j = 0; j < i; j++)
888 brelse (sbi->s_group_desc[j]);
889 printk ("EXT2-fs: unable to read group descriptors\n");
890 goto failed_mount_group_desc;
891 }
892 }
893 if (!ext2_check_descriptors (sb)) {
894 printk ("EXT2-fs: group descriptors corrupted!\n");
895 goto failed_mount2;
896 }
897 sbi->s_gdb_count = db_count;
898 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
899 spin_lock_init(&sbi->s_next_gen_lock);
900
901 percpu_counter_init(&sbi->s_freeblocks_counter,
902 ext2_count_free_blocks(sb));
903 percpu_counter_init(&sbi->s_freeinodes_counter,
904 ext2_count_free_inodes(sb));
905 percpu_counter_init(&sbi->s_dirs_counter,
906 ext2_count_dirs(sb));
907 /*
908 * set up enough so that it can read an inode
909 */
910 sb->s_op = &ext2_sops;
911 sb->s_export_op = &ext2_export_ops;
912 sb->s_xattr = ext2_xattr_handlers;
913 root = iget(sb, EXT2_ROOT_INO);
914 sb->s_root = d_alloc_root(root);
915 if (!sb->s_root) {
916 iput(root);
917 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
918 goto failed_mount3;
919 }
920 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
921 dput(sb->s_root);
922 sb->s_root = NULL;
923 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
924 goto failed_mount3;
925 }
926 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
927 ext2_warning(sb, __FUNCTION__,
928 "mounting ext3 filesystem as ext2");
929 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
930 return 0;
931
932 cantfind_ext2:
933 if (!silent)
934 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
935 sb->s_id);
936 goto failed_mount;
937 failed_mount3:
938 percpu_counter_destroy(&sbi->s_freeblocks_counter);
939 percpu_counter_destroy(&sbi->s_freeinodes_counter);
940 percpu_counter_destroy(&sbi->s_dirs_counter);
941 failed_mount2:
942 for (i = 0; i < db_count; i++)
943 brelse(sbi->s_group_desc[i]);
944 failed_mount_group_desc:
945 kfree(sbi->s_group_desc);
946 kfree(sbi->s_debts);
947 failed_mount:
948 brelse(bh);
949 failed_sbi:
950 sb->s_fs_info = NULL;
951 kfree(sbi);
952 return -EINVAL;
953 }
954
955 static void ext2_commit_super (struct super_block * sb,
956 struct ext2_super_block * es)
957 {
958 es->s_wtime = cpu_to_le32(get_seconds());
959 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
960 sb->s_dirt = 0;
961 }
962
963 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
964 {
965 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
966 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
967 es->s_wtime = cpu_to_le32(get_seconds());
968 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
969 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
970 sb->s_dirt = 0;
971 }
972
973 /*
974 * In the second extended file system, it is not necessary to
975 * write the super block since we use a mapping of the
976 * disk super block in a buffer.
977 *
978 * However, this function is still used to set the fs valid
979 * flags to 0. We need to set this flag to 0 since the fs
980 * may have been checked while mounted and e2fsck may have
981 * set s_state to EXT2_VALID_FS after some corrections.
982 */
983
984 void ext2_write_super (struct super_block * sb)
985 {
986 struct ext2_super_block * es;
987 lock_kernel();
988 if (!(sb->s_flags & MS_RDONLY)) {
989 es = EXT2_SB(sb)->s_es;
990
991 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
992 ext2_debug ("setting valid to 0\n");
993 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
994 ~EXT2_VALID_FS);
995 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
996 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
997 es->s_mtime = cpu_to_le32(get_seconds());
998 ext2_sync_super(sb, es);
999 } else
1000 ext2_commit_super (sb, es);
1001 }
1002 sb->s_dirt = 0;
1003 unlock_kernel();
1004 }
1005
1006 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1007 {
1008 struct ext2_sb_info * sbi = EXT2_SB(sb);
1009 struct ext2_super_block * es;
1010 unsigned long old_mount_opt = sbi->s_mount_opt;
1011 struct ext2_mount_options old_opts;
1012 unsigned long old_sb_flags;
1013 int err;
1014
1015 /* Store the old options */
1016 old_sb_flags = sb->s_flags;
1017 old_opts.s_mount_opt = sbi->s_mount_opt;
1018 old_opts.s_resuid = sbi->s_resuid;
1019 old_opts.s_resgid = sbi->s_resgid;
1020
1021 /*
1022 * Allow the "check" option to be passed as a remount option.
1023 */
1024 if (!parse_options (data, sbi)) {
1025 err = -EINVAL;
1026 goto restore_opts;
1027 }
1028
1029 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1030 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1031
1032 es = sbi->s_es;
1033 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1034 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1035 invalidate_inodes(sb))
1036 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
1037 "xip remain in cache (no functional problem)");
1038 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1039 return 0;
1040 if (*flags & MS_RDONLY) {
1041 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1042 !(sbi->s_mount_state & EXT2_VALID_FS))
1043 return 0;
1044 /*
1045 * OK, we are remounting a valid rw partition rdonly, so set
1046 * the rdonly flag and then mark the partition as valid again.
1047 */
1048 es->s_state = cpu_to_le16(sbi->s_mount_state);
1049 es->s_mtime = cpu_to_le32(get_seconds());
1050 } else {
1051 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1052 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1053 if (ret) {
1054 printk("EXT2-fs: %s: couldn't remount RDWR because of "
1055 "unsupported optional features (%x).\n",
1056 sb->s_id, le32_to_cpu(ret));
1057 err = -EROFS;
1058 goto restore_opts;
1059 }
1060 /*
1061 * Mounting a RDONLY partition read-write, so reread and
1062 * store the current valid flag. (It may have been changed
1063 * by e2fsck since we originally mounted the partition.)
1064 */
1065 sbi->s_mount_state = le16_to_cpu(es->s_state);
1066 if (!ext2_setup_super (sb, es, 0))
1067 sb->s_flags &= ~MS_RDONLY;
1068 }
1069 ext2_sync_super(sb, es);
1070 return 0;
1071 restore_opts:
1072 sbi->s_mount_opt = old_opts.s_mount_opt;
1073 sbi->s_resuid = old_opts.s_resuid;
1074 sbi->s_resgid = old_opts.s_resgid;
1075 sb->s_flags = old_sb_flags;
1076 return err;
1077 }
1078
1079 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1080 {
1081 struct super_block *sb = dentry->d_sb;
1082 struct ext2_sb_info *sbi = EXT2_SB(sb);
1083 unsigned long overhead;
1084 int i;
1085
1086 lock_super(sb);
1087 if (test_opt (sb, MINIX_DF))
1088 overhead = 0;
1089 else {
1090 /*
1091 * Compute the overhead (FS structures)
1092 */
1093
1094 /*
1095 * All of the blocks before first_data_block are
1096 * overhead
1097 */
1098 overhead = le32_to_cpu(sbi->s_es->s_first_data_block);
1099
1100 /*
1101 * Add the overhead attributed to the superblock and
1102 * block group descriptors. If the sparse superblocks
1103 * feature is turned on, then not all groups have this.
1104 */
1105 for (i = 0; i < sbi->s_groups_count; i++)
1106 overhead += ext2_bg_has_super(sb, i) +
1107 ext2_bg_num_gdb(sb, i);
1108
1109 /*
1110 * Every block group has an inode bitmap, a block
1111 * bitmap, and an inode table.
1112 */
1113 overhead += (sbi->s_groups_count *
1114 (2 + sbi->s_itb_per_group));
1115 }
1116
1117 buf->f_type = EXT2_SUPER_MAGIC;
1118 buf->f_bsize = sb->s_blocksize;
1119 buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead;
1120 buf->f_bfree = ext2_count_free_blocks(sb);
1121 buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count);
1122 if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count))
1123 buf->f_bavail = 0;
1124 buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count);
1125 buf->f_ffree = ext2_count_free_inodes (sb);
1126 buf->f_namelen = EXT2_NAME_LEN;
1127 unlock_super(sb);
1128 return 0;
1129 }
1130
1131 static int ext2_get_sb(struct file_system_type *fs_type,
1132 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1133 {
1134 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1135 }
1136
1137 #ifdef CONFIG_QUOTA
1138
1139 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1140 * acquiring the locks... As quota files are never truncated and quota code
1141 * itself serializes the operations (and noone else should touch the files)
1142 * we don't have to be afraid of races */
1143 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1144 size_t len, loff_t off)
1145 {
1146 struct inode *inode = sb_dqopt(sb)->files[type];
1147 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1148 int err = 0;
1149 int offset = off & (sb->s_blocksize - 1);
1150 int tocopy;
1151 size_t toread;
1152 struct buffer_head tmp_bh;
1153 struct buffer_head *bh;
1154 loff_t i_size = i_size_read(inode);
1155
1156 if (off > i_size)
1157 return 0;
1158 if (off+len > i_size)
1159 len = i_size-off;
1160 toread = len;
1161 while (toread > 0) {
1162 tocopy = sb->s_blocksize - offset < toread ?
1163 sb->s_blocksize - offset : toread;
1164
1165 tmp_bh.b_state = 0;
1166 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1167 if (err)
1168 return err;
1169 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1170 memset(data, 0, tocopy);
1171 else {
1172 bh = sb_bread(sb, tmp_bh.b_blocknr);
1173 if (!bh)
1174 return -EIO;
1175 memcpy(data, bh->b_data+offset, tocopy);
1176 brelse(bh);
1177 }
1178 offset = 0;
1179 toread -= tocopy;
1180 data += tocopy;
1181 blk++;
1182 }
1183 return len;
1184 }
1185
1186 /* Write to quotafile */
1187 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1188 const char *data, size_t len, loff_t off)
1189 {
1190 struct inode *inode = sb_dqopt(sb)->files[type];
1191 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1192 int err = 0;
1193 int offset = off & (sb->s_blocksize - 1);
1194 int tocopy;
1195 size_t towrite = len;
1196 struct buffer_head tmp_bh;
1197 struct buffer_head *bh;
1198
1199 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1200 while (towrite > 0) {
1201 tocopy = sb->s_blocksize - offset < towrite ?
1202 sb->s_blocksize - offset : towrite;
1203
1204 tmp_bh.b_state = 0;
1205 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1206 if (err)
1207 goto out;
1208 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1209 bh = sb_bread(sb, tmp_bh.b_blocknr);
1210 else
1211 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1212 if (!bh) {
1213 err = -EIO;
1214 goto out;
1215 }
1216 lock_buffer(bh);
1217 memcpy(bh->b_data+offset, data, tocopy);
1218 flush_dcache_page(bh->b_page);
1219 set_buffer_uptodate(bh);
1220 mark_buffer_dirty(bh);
1221 unlock_buffer(bh);
1222 brelse(bh);
1223 offset = 0;
1224 towrite -= tocopy;
1225 data += tocopy;
1226 blk++;
1227 }
1228 out:
1229 if (len == towrite)
1230 return err;
1231 if (inode->i_size < off+len-towrite)
1232 i_size_write(inode, off+len-towrite);
1233 inode->i_version++;
1234 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1235 mark_inode_dirty(inode);
1236 mutex_unlock(&inode->i_mutex);
1237 return len - towrite;
1238 }
1239
1240 #endif
1241
1242 static struct file_system_type ext2_fs_type = {
1243 .owner = THIS_MODULE,
1244 .name = "ext2",
1245 .get_sb = ext2_get_sb,
1246 .kill_sb = kill_block_super,
1247 .fs_flags = FS_REQUIRES_DEV,
1248 };
1249
1250 static int __init init_ext2_fs(void)
1251 {
1252 int err = init_ext2_xattr();
1253 if (err)
1254 return err;
1255 err = init_inodecache();
1256 if (err)
1257 goto out1;
1258 err = register_filesystem(&ext2_fs_type);
1259 if (err)
1260 goto out;
1261 return 0;
1262 out:
1263 destroy_inodecache();
1264 out1:
1265 exit_ext2_xattr();
1266 return err;
1267 }
1268
1269 static void __exit exit_ext2_fs(void)
1270 {
1271 unregister_filesystem(&ext2_fs_type);
1272 destroy_inodecache();
1273 exit_ext2_xattr();
1274 }
1275
1276 module_init(init_ext2_fs)
1277 module_exit(exit_ext2_fs)
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