2 * linux/fs/ext2/super.c
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)
11 * linux/fs/minix/inode.c
13 * Copyright (C) 1991, 1992 Linus Torvalds
15 * Big-endian to little-endian byte-swapping/bitmaps by
16 * David S. Miller (davem@caip.rutgers.edu), 1995
19 #include <linux/module.h>
20 #include <linux/string.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/vfs.h>
30 #include <linux/seq_file.h>
31 #include <linux/mount.h>
32 #include <linux/log2.h>
33 #include <linux/quotaops.h>
34 #include <asm/uaccess.h>
40 static void ext2_sync_super(struct super_block *sb,
41 struct ext2_super_block *es, int wait);
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 static int ext2_sync_fs(struct super_block *sb, int wait);
46 void ext2_error (struct super_block * sb, const char * function,
47 const char * fmt, ...)
50 struct ext2_sb_info *sbi = EXT2_SB(sb);
51 struct ext2_super_block *es = sbi->s_es;
53 if (!(sb->s_flags & MS_RDONLY)) {
54 spin_lock(&sbi->s_lock);
55 sbi->s_mount_state |= EXT2_ERROR_FS;
56 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
57 spin_unlock(&sbi->s_lock);
58 ext2_sync_super(sb, es, 1);
62 printk(KERN_CRIT "EXT2-fs (%s): error: %s: ", sb->s_id, function);
67 if (test_opt(sb, ERRORS_PANIC))
68 panic("EXT2-fs: panic from previous error\n");
69 if (test_opt(sb, ERRORS_RO)) {
70 ext2_msg(sb, KERN_CRIT,
71 "error: remounting filesystem read-only");
72 sb->s_flags |= MS_RDONLY;
76 void ext2_msg(struct super_block *sb, const char *prefix,
82 printk("%sEXT2-fs (%s): ", prefix, sb->s_id);
89 * This must be called with sbi->s_lock held.
91 void ext2_update_dynamic_rev(struct super_block *sb)
93 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
95 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
98 ext2_msg(sb, KERN_WARNING,
99 "warning: updating to rev %d because of "
100 "new feature flag, running e2fsck is recommended",
103 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
104 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
105 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
106 /* leave es->s_feature_*compat flags alone */
107 /* es->s_uuid will be set by e2fsck if empty */
110 * The rest of the superblock fields should be zero, and if not it
111 * means they are likely already in use, so leave them alone. We
112 * can leave it up to e2fsck to clean up any inconsistencies there.
116 static void ext2_put_super (struct super_block * sb)
120 struct ext2_sb_info *sbi = EXT2_SB(sb);
122 dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
125 ext2_write_super(sb);
127 ext2_xattr_put_super(sb);
128 if (!(sb->s_flags & MS_RDONLY)) {
129 struct ext2_super_block *es = sbi->s_es;
131 spin_lock(&sbi->s_lock);
132 es->s_state = cpu_to_le16(sbi->s_mount_state);
133 spin_unlock(&sbi->s_lock);
134 ext2_sync_super(sb, es, 1);
136 db_count = sbi->s_gdb_count;
137 for (i = 0; i < db_count; i++)
138 if (sbi->s_group_desc[i])
139 brelse (sbi->s_group_desc[i]);
140 kfree(sbi->s_group_desc);
142 percpu_counter_destroy(&sbi->s_freeblocks_counter);
143 percpu_counter_destroy(&sbi->s_freeinodes_counter);
144 percpu_counter_destroy(&sbi->s_dirs_counter);
146 sb->s_fs_info = NULL;
147 kfree(sbi->s_blockgroup_lock);
151 static struct kmem_cache * ext2_inode_cachep;
153 static struct inode *ext2_alloc_inode(struct super_block *sb)
155 struct ext2_inode_info *ei;
156 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
159 ei->i_block_alloc_info = NULL;
160 ei->vfs_inode.i_version = 1;
161 return &ei->vfs_inode;
164 static void ext2_i_callback(struct rcu_head *head)
166 struct inode *inode = container_of(head, struct inode, i_rcu);
167 INIT_LIST_HEAD(&inode->i_dentry);
168 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
171 static void ext2_destroy_inode(struct inode *inode)
173 call_rcu(&inode->i_rcu, ext2_i_callback);
176 static void init_once(void *foo)
178 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
180 rwlock_init(&ei->i_meta_lock);
181 #ifdef CONFIG_EXT2_FS_XATTR
182 init_rwsem(&ei->xattr_sem);
184 mutex_init(&ei->truncate_mutex);
185 inode_init_once(&ei->vfs_inode);
188 static int init_inodecache(void)
190 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
191 sizeof(struct ext2_inode_info),
192 0, (SLAB_RECLAIM_ACCOUNT|
195 if (ext2_inode_cachep == NULL)
200 static void destroy_inodecache(void)
202 kmem_cache_destroy(ext2_inode_cachep);
205 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
207 struct super_block *sb = vfs->mnt_sb;
208 struct ext2_sb_info *sbi = EXT2_SB(sb);
209 struct ext2_super_block *es = sbi->s_es;
210 unsigned long def_mount_opts;
212 spin_lock(&sbi->s_lock);
213 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
215 if (sbi->s_sb_block != 1)
216 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
217 if (test_opt(sb, MINIX_DF))
218 seq_puts(seq, ",minixdf");
219 if (test_opt(sb, GRPID))
220 seq_puts(seq, ",grpid");
221 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
222 seq_puts(seq, ",nogrpid");
223 if (sbi->s_resuid != EXT2_DEF_RESUID ||
224 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
225 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
227 if (sbi->s_resgid != EXT2_DEF_RESGID ||
228 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
229 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
231 if (test_opt(sb, ERRORS_RO)) {
232 int def_errors = le16_to_cpu(es->s_errors);
234 if (def_errors == EXT2_ERRORS_PANIC ||
235 def_errors == EXT2_ERRORS_CONTINUE) {
236 seq_puts(seq, ",errors=remount-ro");
239 if (test_opt(sb, ERRORS_CONT))
240 seq_puts(seq, ",errors=continue");
241 if (test_opt(sb, ERRORS_PANIC))
242 seq_puts(seq, ",errors=panic");
243 if (test_opt(sb, NO_UID32))
244 seq_puts(seq, ",nouid32");
245 if (test_opt(sb, DEBUG))
246 seq_puts(seq, ",debug");
247 if (test_opt(sb, OLDALLOC))
248 seq_puts(seq, ",oldalloc");
250 #ifdef CONFIG_EXT2_FS_XATTR
251 if (test_opt(sb, XATTR_USER))
252 seq_puts(seq, ",user_xattr");
253 if (!test_opt(sb, XATTR_USER) &&
254 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
255 seq_puts(seq, ",nouser_xattr");
259 #ifdef CONFIG_EXT2_FS_POSIX_ACL
260 if (test_opt(sb, POSIX_ACL))
261 seq_puts(seq, ",acl");
262 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
263 seq_puts(seq, ",noacl");
266 if (test_opt(sb, NOBH))
267 seq_puts(seq, ",nobh");
269 #if defined(CONFIG_QUOTA)
270 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
271 seq_puts(seq, ",usrquota");
273 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
274 seq_puts(seq, ",grpquota");
277 #if defined(CONFIG_EXT2_FS_XIP)
278 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
279 seq_puts(seq, ",xip");
282 if (!test_opt(sb, RESERVATION))
283 seq_puts(seq, ",noreservation");
285 spin_unlock(&sbi->s_lock);
290 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
291 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
294 static const struct super_operations ext2_sops = {
295 .alloc_inode = ext2_alloc_inode,
296 .destroy_inode = ext2_destroy_inode,
297 .write_inode = ext2_write_inode,
298 .evict_inode = ext2_evict_inode,
299 .put_super = ext2_put_super,
300 .write_super = ext2_write_super,
301 .sync_fs = ext2_sync_fs,
302 .statfs = ext2_statfs,
303 .remount_fs = ext2_remount,
304 .show_options = ext2_show_options,
306 .quota_read = ext2_quota_read,
307 .quota_write = ext2_quota_write,
311 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
312 u64 ino, u32 generation)
316 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
317 return ERR_PTR(-ESTALE);
318 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
319 return ERR_PTR(-ESTALE);
321 /* iget isn't really right if the inode is currently unallocated!!
322 * ext2_read_inode currently does appropriate checks, but
323 * it might be "neater" to call ext2_get_inode first and check
324 * if the inode is valid.....
326 inode = ext2_iget(sb, ino);
328 return ERR_CAST(inode);
329 if (generation && inode->i_generation != generation) {
330 /* we didn't find the right inode.. */
332 return ERR_PTR(-ESTALE);
337 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
338 int fh_len, int fh_type)
340 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
344 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
345 int fh_len, int fh_type)
347 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
351 /* Yes, most of these are left as NULL!!
352 * A NULL value implies the default, which works with ext2-like file
353 * systems, but can be improved upon.
354 * Currently only get_parent is required.
356 static const struct export_operations ext2_export_ops = {
357 .fh_to_dentry = ext2_fh_to_dentry,
358 .fh_to_parent = ext2_fh_to_parent,
359 .get_parent = ext2_get_parent,
362 static unsigned long get_sb_block(void **data)
364 unsigned long sb_block;
365 char *options = (char *) *data;
367 if (!options || strncmp(options, "sb=", 3) != 0)
368 return 1; /* Default location */
370 sb_block = simple_strtoul(options, &options, 0);
371 if (*options && *options != ',') {
372 printk("EXT2-fs: Invalid sb specification: %s\n",
378 *data = (void *) options;
383 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
384 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
385 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
386 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
387 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
388 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
391 static const match_table_t tokens = {
392 {Opt_bsd_df, "bsddf"},
393 {Opt_minix_df, "minixdf"},
394 {Opt_grpid, "grpid"},
395 {Opt_grpid, "bsdgroups"},
396 {Opt_nogrpid, "nogrpid"},
397 {Opt_nogrpid, "sysvgroups"},
398 {Opt_resgid, "resgid=%u"},
399 {Opt_resuid, "resuid=%u"},
401 {Opt_err_cont, "errors=continue"},
402 {Opt_err_panic, "errors=panic"},
403 {Opt_err_ro, "errors=remount-ro"},
404 {Opt_nouid32, "nouid32"},
405 {Opt_nocheck, "check=none"},
406 {Opt_nocheck, "nocheck"},
407 {Opt_debug, "debug"},
408 {Opt_oldalloc, "oldalloc"},
409 {Opt_orlov, "orlov"},
411 {Opt_user_xattr, "user_xattr"},
412 {Opt_nouser_xattr, "nouser_xattr"},
414 {Opt_noacl, "noacl"},
416 {Opt_grpquota, "grpquota"},
417 {Opt_ignore, "noquota"},
418 {Opt_quota, "quota"},
419 {Opt_usrquota, "usrquota"},
420 {Opt_reservation, "reservation"},
421 {Opt_noreservation, "noreservation"},
425 static int parse_options(char *options, struct super_block *sb)
428 struct ext2_sb_info *sbi = EXT2_SB(sb);
429 substring_t args[MAX_OPT_ARGS];
435 while ((p = strsep (&options, ",")) != NULL) {
440 token = match_token(p, tokens, args);
443 clear_opt (sbi->s_mount_opt, MINIX_DF);
446 set_opt (sbi->s_mount_opt, MINIX_DF);
449 set_opt (sbi->s_mount_opt, GRPID);
452 clear_opt (sbi->s_mount_opt, GRPID);
455 if (match_int(&args[0], &option))
457 sbi->s_resuid = option;
460 if (match_int(&args[0], &option))
462 sbi->s_resgid = option;
465 /* handled by get_sb_block() instead of here */
466 /* *sb_block = match_int(&args[0]); */
469 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
470 clear_opt (sbi->s_mount_opt, ERRORS_RO);
471 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
474 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
475 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
476 set_opt (sbi->s_mount_opt, ERRORS_RO);
479 clear_opt (sbi->s_mount_opt, ERRORS_RO);
480 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
481 set_opt (sbi->s_mount_opt, ERRORS_CONT);
484 set_opt (sbi->s_mount_opt, NO_UID32);
487 clear_opt (sbi->s_mount_opt, CHECK);
490 set_opt (sbi->s_mount_opt, DEBUG);
493 set_opt (sbi->s_mount_opt, OLDALLOC);
496 clear_opt (sbi->s_mount_opt, OLDALLOC);
499 set_opt (sbi->s_mount_opt, NOBH);
501 #ifdef CONFIG_EXT2_FS_XATTR
503 set_opt (sbi->s_mount_opt, XATTR_USER);
505 case Opt_nouser_xattr:
506 clear_opt (sbi->s_mount_opt, XATTR_USER);
510 case Opt_nouser_xattr:
511 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
515 #ifdef CONFIG_EXT2_FS_POSIX_ACL
517 set_opt(sbi->s_mount_opt, POSIX_ACL);
520 clear_opt(sbi->s_mount_opt, POSIX_ACL);
525 ext2_msg(sb, KERN_INFO,
526 "(no)acl options not supported");
530 #ifdef CONFIG_EXT2_FS_XIP
531 set_opt (sbi->s_mount_opt, XIP);
533 ext2_msg(sb, KERN_INFO, "xip option not supported");
537 #if defined(CONFIG_QUOTA)
540 set_opt(sbi->s_mount_opt, USRQUOTA);
544 set_opt(sbi->s_mount_opt, GRPQUOTA);
550 ext2_msg(sb, KERN_INFO,
551 "quota operations not supported");
555 case Opt_reservation:
556 set_opt(sbi->s_mount_opt, RESERVATION);
557 ext2_msg(sb, KERN_INFO, "reservations ON");
559 case Opt_noreservation:
560 clear_opt(sbi->s_mount_opt, RESERVATION);
561 ext2_msg(sb, KERN_INFO, "reservations OFF");
572 static int ext2_setup_super (struct super_block * sb,
573 struct ext2_super_block * es,
577 struct ext2_sb_info *sbi = EXT2_SB(sb);
579 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
580 ext2_msg(sb, KERN_ERR,
581 "error: revision level too high, "
582 "forcing read-only mode");
587 if (!(sbi->s_mount_state & EXT2_VALID_FS))
588 ext2_msg(sb, KERN_WARNING,
589 "warning: mounting unchecked fs, "
590 "running e2fsck is recommended");
591 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
592 ext2_msg(sb, KERN_WARNING,
593 "warning: mounting fs with errors, "
594 "running e2fsck is recommended");
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 ext2_msg(sb, KERN_WARNING,
599 "warning: maximal mount count reached, "
600 "running e2fsck is recommended");
601 else if (le32_to_cpu(es->s_checkinterval) &&
602 (le32_to_cpu(es->s_lastcheck) +
603 le32_to_cpu(es->s_checkinterval) <= get_seconds()))
604 ext2_msg(sb, KERN_WARNING,
605 "warning: checktime reached, "
606 "running e2fsck is recommended");
607 if (!le16_to_cpu(es->s_max_mnt_count))
608 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
609 le16_add_cpu(&es->s_mnt_count, 1);
610 if (test_opt (sb, DEBUG))
611 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
612 "bpg=%lu, ipg=%lu, mo=%04lx]",
613 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
616 EXT2_BLOCKS_PER_GROUP(sb),
617 EXT2_INODES_PER_GROUP(sb),
622 static int ext2_check_descriptors(struct super_block *sb)
625 struct ext2_sb_info *sbi = EXT2_SB(sb);
627 ext2_debug ("Checking group descriptors");
629 for (i = 0; i < sbi->s_groups_count; i++) {
630 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
631 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
632 ext2_fsblk_t last_block;
634 if (i == sbi->s_groups_count - 1)
635 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
637 last_block = first_block +
638 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
640 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
641 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
643 ext2_error (sb, "ext2_check_descriptors",
644 "Block bitmap for group %d"
645 " not in group (block %lu)!",
646 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
649 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
650 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
652 ext2_error (sb, "ext2_check_descriptors",
653 "Inode bitmap for group %d"
654 " not in group (block %lu)!",
655 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
658 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
659 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
662 ext2_error (sb, "ext2_check_descriptors",
663 "Inode table for group %d"
664 " not in group (block %lu)!",
665 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
673 * Maximal file size. There is a direct, and {,double-,triple-}indirect
674 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
675 * We need to be 1 filesystem block less than the 2^32 sector limit.
677 static loff_t ext2_max_size(int bits)
679 loff_t res = EXT2_NDIR_BLOCKS;
683 /* This is calculated to be the largest file size for a
684 * dense, file such that the total number of
685 * sectors in the file, including data and all indirect blocks,
686 * does not exceed 2^32 -1
687 * __u32 i_blocks representing the total number of
688 * 512 bytes blocks of the file
690 upper_limit = (1LL << 32) - 1;
692 /* total blocks in file system block size */
693 upper_limit >>= (bits - 9);
696 /* indirect blocks */
698 /* double indirect blocks */
699 meta_blocks += 1 + (1LL << (bits-2));
700 /* tripple indirect blocks */
701 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
703 upper_limit -= meta_blocks;
704 upper_limit <<= bits;
706 res += 1LL << (bits-2);
707 res += 1LL << (2*(bits-2));
708 res += 1LL << (3*(bits-2));
710 if (res > upper_limit)
713 if (res > MAX_LFS_FILESIZE)
714 res = MAX_LFS_FILESIZE;
719 static unsigned long descriptor_loc(struct super_block *sb,
720 unsigned long logic_sb_block,
723 struct ext2_sb_info *sbi = EXT2_SB(sb);
724 unsigned long bg, first_meta_bg;
727 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
729 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
731 return (logic_sb_block + nr + 1);
732 bg = sbi->s_desc_per_block * nr;
733 if (ext2_bg_has_super(sb, bg))
736 return ext2_group_first_block_no(sb, bg) + has_super;
739 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
741 struct buffer_head * bh;
742 struct ext2_sb_info * sbi;
743 struct ext2_super_block * es;
746 unsigned long sb_block = get_sb_block(&data);
747 unsigned long logic_sb_block;
748 unsigned long offset = 0;
749 unsigned long def_mount_opts;
751 int blocksize = BLOCK_SIZE;
758 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
762 sbi->s_blockgroup_lock =
763 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
764 if (!sbi->s_blockgroup_lock) {
769 sbi->s_sb_block = sb_block;
771 spin_lock_init(&sbi->s_lock);
774 * See what the current blocksize for the device is, and
775 * use that as the blocksize. Otherwise (or if the blocksize
776 * is smaller than the default) use the default.
777 * This is important for devices that have a hardware
778 * sectorsize that is larger than the default.
780 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
782 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
787 * If the superblock doesn't start on a hardware sector boundary,
788 * calculate the offset.
790 if (blocksize != BLOCK_SIZE) {
791 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
792 offset = (sb_block*BLOCK_SIZE) % blocksize;
794 logic_sb_block = sb_block;
797 if (!(bh = sb_bread(sb, logic_sb_block))) {
798 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
802 * Note: s_es must be initialized as soon as possible because
803 * some ext2 macro-instructions depend on its value
805 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
807 sb->s_magic = le16_to_cpu(es->s_magic);
809 if (sb->s_magic != EXT2_SUPER_MAGIC)
812 /* Set defaults before we parse the mount options */
813 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
814 if (def_mount_opts & EXT2_DEFM_DEBUG)
815 set_opt(sbi->s_mount_opt, DEBUG);
816 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
817 set_opt(sbi->s_mount_opt, GRPID);
818 if (def_mount_opts & EXT2_DEFM_UID16)
819 set_opt(sbi->s_mount_opt, NO_UID32);
820 #ifdef CONFIG_EXT2_FS_XATTR
821 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
822 set_opt(sbi->s_mount_opt, XATTR_USER);
824 #ifdef CONFIG_EXT2_FS_POSIX_ACL
825 if (def_mount_opts & EXT2_DEFM_ACL)
826 set_opt(sbi->s_mount_opt, POSIX_ACL);
829 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
830 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
831 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
832 set_opt(sbi->s_mount_opt, ERRORS_CONT);
834 set_opt(sbi->s_mount_opt, ERRORS_RO);
836 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
837 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
839 set_opt(sbi->s_mount_opt, RESERVATION);
841 if (!parse_options((char *) data, sb))
844 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
845 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
848 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
849 EXT2_MOUNT_XIP if not */
851 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
852 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
853 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
854 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
855 ext2_msg(sb, KERN_WARNING,
856 "warning: feature flags set on rev 0 fs, "
857 "running e2fsck is recommended");
859 * Check feature flags regardless of the revision level, since we
860 * previously didn't change the revision level when setting the flags,
861 * so there is a chance incompat flags are set on a rev 0 filesystem.
863 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
865 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
866 "unsupported optional features (%x)",
867 le32_to_cpu(features));
870 if (!(sb->s_flags & MS_RDONLY) &&
871 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
872 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
873 "unsupported optional features (%x)",
874 le32_to_cpu(features));
878 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
880 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
882 ext2_msg(sb, KERN_ERR,
883 "error: unsupported blocksize for xip");
887 /* If the blocksize doesn't match, re-read the thing.. */
888 if (sb->s_blocksize != blocksize) {
891 if (!sb_set_blocksize(sb, blocksize)) {
892 ext2_msg(sb, KERN_ERR, "error: blocksize is too small");
896 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
897 offset = (sb_block*BLOCK_SIZE) % blocksize;
898 bh = sb_bread(sb, logic_sb_block);
900 ext2_msg(sb, KERN_ERR, "error: couldn't read"
901 "superblock on 2nd try");
904 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
906 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
907 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
912 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
914 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
915 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
916 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
918 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
919 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
920 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
921 !is_power_of_2(sbi->s_inode_size) ||
922 (sbi->s_inode_size > blocksize)) {
923 ext2_msg(sb, KERN_ERR,
924 "error: unsupported inode size: %d",
930 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
931 le32_to_cpu(es->s_log_frag_size);
932 if (sbi->s_frag_size == 0)
934 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
936 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
937 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
938 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
940 if (EXT2_INODE_SIZE(sb) == 0)
942 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
943 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
945 sbi->s_itb_per_group = sbi->s_inodes_per_group /
946 sbi->s_inodes_per_block;
947 sbi->s_desc_per_block = sb->s_blocksize /
948 sizeof (struct ext2_group_desc);
950 sbi->s_mount_state = le16_to_cpu(es->s_state);
951 sbi->s_addr_per_block_bits =
952 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
953 sbi->s_desc_per_block_bits =
954 ilog2 (EXT2_DESC_PER_BLOCK(sb));
956 if (sb->s_magic != EXT2_SUPER_MAGIC)
959 if (sb->s_blocksize != bh->b_size) {
961 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
965 if (sb->s_blocksize != sbi->s_frag_size) {
966 ext2_msg(sb, KERN_ERR,
967 "error: fragsize %lu != blocksize %lu"
968 "(not supported yet)",
969 sbi->s_frag_size, sb->s_blocksize);
973 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
974 ext2_msg(sb, KERN_ERR,
975 "error: #blocks per group too big: %lu",
976 sbi->s_blocks_per_group);
979 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
980 ext2_msg(sb, KERN_ERR,
981 "error: #fragments per group too big: %lu",
982 sbi->s_frags_per_group);
985 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
986 ext2_msg(sb, KERN_ERR,
987 "error: #inodes per group too big: %lu",
988 sbi->s_inodes_per_group);
992 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
994 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
995 le32_to_cpu(es->s_first_data_block) - 1)
996 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
997 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
998 EXT2_DESC_PER_BLOCK(sb);
999 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1000 if (sbi->s_group_desc == NULL) {
1001 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1004 bgl_lock_init(sbi->s_blockgroup_lock);
1005 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1006 if (!sbi->s_debts) {
1007 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1008 goto failed_mount_group_desc;
1010 for (i = 0; i < db_count; i++) {
1011 block = descriptor_loc(sb, logic_sb_block, i);
1012 sbi->s_group_desc[i] = sb_bread(sb, block);
1013 if (!sbi->s_group_desc[i]) {
1014 for (j = 0; j < i; j++)
1015 brelse (sbi->s_group_desc[j]);
1016 ext2_msg(sb, KERN_ERR,
1017 "error: unable to read group descriptors");
1018 goto failed_mount_group_desc;
1021 if (!ext2_check_descriptors (sb)) {
1022 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1025 sbi->s_gdb_count = db_count;
1026 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1027 spin_lock_init(&sbi->s_next_gen_lock);
1029 /* per fileystem reservation list head & lock */
1030 spin_lock_init(&sbi->s_rsv_window_lock);
1031 sbi->s_rsv_window_root = RB_ROOT;
1033 * Add a single, static dummy reservation to the start of the
1034 * reservation window list --- it gives us a placeholder for
1035 * append-at-start-of-list which makes the allocation logic
1038 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1039 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1040 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1041 sbi->s_rsv_window_head.rsv_goal_size = 0;
1042 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1044 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1045 ext2_count_free_blocks(sb));
1047 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1048 ext2_count_free_inodes(sb));
1051 err = percpu_counter_init(&sbi->s_dirs_counter,
1052 ext2_count_dirs(sb));
1055 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1059 * set up enough so that it can read an inode
1061 sb->s_op = &ext2_sops;
1062 sb->s_export_op = &ext2_export_ops;
1063 sb->s_xattr = ext2_xattr_handlers;
1066 sb->dq_op = &dquot_operations;
1067 sb->s_qcop = &dquot_quotactl_ops;
1070 root = ext2_iget(sb, EXT2_ROOT_INO);
1072 ret = PTR_ERR(root);
1075 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1077 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1081 sb->s_root = d_alloc_root(root);
1084 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1088 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1089 ext2_msg(sb, KERN_WARNING,
1090 "warning: mounting ext3 filesystem as ext2");
1091 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1092 sb->s_flags |= MS_RDONLY;
1093 ext2_write_super(sb);
1098 ext2_msg(sb, KERN_ERR,
1099 "error: can't find an ext2 filesystem on dev %s.",
1103 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1104 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1105 percpu_counter_destroy(&sbi->s_dirs_counter);
1107 for (i = 0; i < db_count; i++)
1108 brelse(sbi->s_group_desc[i]);
1109 failed_mount_group_desc:
1110 kfree(sbi->s_group_desc);
1111 kfree(sbi->s_debts);
1115 sb->s_fs_info = NULL;
1116 kfree(sbi->s_blockgroup_lock);
1122 static void ext2_clear_super_error(struct super_block *sb)
1124 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1126 if (buffer_write_io_error(sbh)) {
1128 * Oh, dear. A previous attempt to write the
1129 * superblock failed. This could happen because the
1130 * USB device was yanked out. Or it could happen to
1131 * be a transient write error and maybe the block will
1132 * be remapped. Nothing we can do but to retry the
1133 * write and hope for the best.
1135 ext2_msg(sb, KERN_ERR,
1136 "previous I/O error to superblock detected\n");
1137 clear_buffer_write_io_error(sbh);
1138 set_buffer_uptodate(sbh);
1142 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1145 ext2_clear_super_error(sb);
1146 spin_lock(&EXT2_SB(sb)->s_lock);
1147 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1148 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1149 es->s_wtime = cpu_to_le32(get_seconds());
1150 /* unlock before we do IO */
1151 spin_unlock(&EXT2_SB(sb)->s_lock);
1152 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1154 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1159 * In the second extended file system, it is not necessary to
1160 * write the super block since we use a mapping of the
1161 * disk super block in a buffer.
1163 * However, this function is still used to set the fs valid
1164 * flags to 0. We need to set this flag to 0 since the fs
1165 * may have been checked while mounted and e2fsck may have
1166 * set s_state to EXT2_VALID_FS after some corrections.
1168 static int ext2_sync_fs(struct super_block *sb, int wait)
1170 struct ext2_sb_info *sbi = EXT2_SB(sb);
1171 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1173 spin_lock(&sbi->s_lock);
1174 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1175 ext2_debug("setting valid to 0\n");
1176 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1178 spin_unlock(&sbi->s_lock);
1179 ext2_sync_super(sb, es, wait);
1184 void ext2_write_super(struct super_block *sb)
1186 if (!(sb->s_flags & MS_RDONLY))
1187 ext2_sync_fs(sb, 1);
1192 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1194 struct ext2_sb_info * sbi = EXT2_SB(sb);
1195 struct ext2_super_block * es;
1196 unsigned long old_mount_opt = sbi->s_mount_opt;
1197 struct ext2_mount_options old_opts;
1198 unsigned long old_sb_flags;
1201 spin_lock(&sbi->s_lock);
1203 /* Store the old options */
1204 old_sb_flags = sb->s_flags;
1205 old_opts.s_mount_opt = sbi->s_mount_opt;
1206 old_opts.s_resuid = sbi->s_resuid;
1207 old_opts.s_resgid = sbi->s_resgid;
1210 * Allow the "check" option to be passed as a remount option.
1212 if (!parse_options(data, sb)) {
1217 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1218 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1220 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1221 EXT2_MOUNT_XIP if not */
1223 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1224 ext2_msg(sb, KERN_WARNING,
1225 "warning: unsupported blocksize for xip");
1231 if ((sbi->s_mount_opt ^ old_mount_opt) & EXT2_MOUNT_XIP) {
1232 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1233 "xip flag with busy inodes while remounting");
1234 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1235 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1237 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1238 spin_unlock(&sbi->s_lock);
1241 if (*flags & MS_RDONLY) {
1242 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1243 !(sbi->s_mount_state & EXT2_VALID_FS)) {
1244 spin_unlock(&sbi->s_lock);
1249 * OK, we are remounting a valid rw partition rdonly, so set
1250 * the rdonly flag and then mark the partition as valid again.
1252 es->s_state = cpu_to_le16(sbi->s_mount_state);
1253 es->s_mtime = cpu_to_le32(get_seconds());
1254 spin_unlock(&sbi->s_lock);
1256 err = dquot_suspend(sb, -1);
1258 spin_lock(&sbi->s_lock);
1262 ext2_sync_super(sb, es, 1);
1264 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1265 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1267 ext2_msg(sb, KERN_WARNING,
1268 "warning: couldn't remount RDWR because of "
1269 "unsupported optional features (%x).",
1275 * Mounting a RDONLY partition read-write, so reread and
1276 * store the current valid flag. (It may have been changed
1277 * by e2fsck since we originally mounted the partition.)
1279 sbi->s_mount_state = le16_to_cpu(es->s_state);
1280 if (!ext2_setup_super (sb, es, 0))
1281 sb->s_flags &= ~MS_RDONLY;
1282 spin_unlock(&sbi->s_lock);
1284 ext2_write_super(sb);
1286 dquot_resume(sb, -1);
1291 sbi->s_mount_opt = old_opts.s_mount_opt;
1292 sbi->s_resuid = old_opts.s_resuid;
1293 sbi->s_resgid = old_opts.s_resgid;
1294 sb->s_flags = old_sb_flags;
1295 spin_unlock(&sbi->s_lock);
1299 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1301 struct super_block *sb = dentry->d_sb;
1302 struct ext2_sb_info *sbi = EXT2_SB(sb);
1303 struct ext2_super_block *es = sbi->s_es;
1306 spin_lock(&sbi->s_lock);
1308 if (test_opt (sb, MINIX_DF))
1309 sbi->s_overhead_last = 0;
1310 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1311 unsigned long i, overhead = 0;
1315 * Compute the overhead (FS structures). This is constant
1316 * for a given filesystem unless the number of block groups
1317 * changes so we cache the previous value until it does.
1321 * All of the blocks before first_data_block are
1324 overhead = le32_to_cpu(es->s_first_data_block);
1327 * Add the overhead attributed to the superblock and
1328 * block group descriptors. If the sparse superblocks
1329 * feature is turned on, then not all groups have this.
1331 for (i = 0; i < sbi->s_groups_count; i++)
1332 overhead += ext2_bg_has_super(sb, i) +
1333 ext2_bg_num_gdb(sb, i);
1336 * Every block group has an inode bitmap, a block
1337 * bitmap, and an inode table.
1339 overhead += (sbi->s_groups_count *
1340 (2 + sbi->s_itb_per_group));
1341 sbi->s_overhead_last = overhead;
1343 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1346 buf->f_type = EXT2_SUPER_MAGIC;
1347 buf->f_bsize = sb->s_blocksize;
1348 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1349 buf->f_bfree = ext2_count_free_blocks(sb);
1350 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1351 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1352 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1354 buf->f_files = le32_to_cpu(es->s_inodes_count);
1355 buf->f_ffree = ext2_count_free_inodes(sb);
1356 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1357 buf->f_namelen = EXT2_NAME_LEN;
1358 fsid = le64_to_cpup((void *)es->s_uuid) ^
1359 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1360 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1361 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1362 spin_unlock(&sbi->s_lock);
1366 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1367 int flags, const char *dev_name, void *data)
1369 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1374 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1375 * acquiring the locks... As quota files are never truncated and quota code
1376 * itself serializes the operations (and noone else should touch the files)
1377 * we don't have to be afraid of races */
1378 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1379 size_t len, loff_t off)
1381 struct inode *inode = sb_dqopt(sb)->files[type];
1382 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1384 int offset = off & (sb->s_blocksize - 1);
1387 struct buffer_head tmp_bh;
1388 struct buffer_head *bh;
1389 loff_t i_size = i_size_read(inode);
1393 if (off+len > i_size)
1396 while (toread > 0) {
1397 tocopy = sb->s_blocksize - offset < toread ?
1398 sb->s_blocksize - offset : toread;
1401 tmp_bh.b_size = sb->s_blocksize;
1402 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1405 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1406 memset(data, 0, tocopy);
1408 bh = sb_bread(sb, tmp_bh.b_blocknr);
1411 memcpy(data, bh->b_data+offset, tocopy);
1422 /* Write to quotafile */
1423 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1424 const char *data, size_t len, loff_t off)
1426 struct inode *inode = sb_dqopt(sb)->files[type];
1427 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1429 int offset = off & (sb->s_blocksize - 1);
1431 size_t towrite = len;
1432 struct buffer_head tmp_bh;
1433 struct buffer_head *bh;
1435 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1436 while (towrite > 0) {
1437 tocopy = sb->s_blocksize - offset < towrite ?
1438 sb->s_blocksize - offset : towrite;
1441 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1444 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1445 bh = sb_bread(sb, tmp_bh.b_blocknr);
1447 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1453 memcpy(bh->b_data+offset, data, tocopy);
1454 flush_dcache_page(bh->b_page);
1455 set_buffer_uptodate(bh);
1456 mark_buffer_dirty(bh);
1465 if (len == towrite) {
1466 mutex_unlock(&inode->i_mutex);
1469 if (inode->i_size < off+len-towrite)
1470 i_size_write(inode, off+len-towrite);
1472 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1473 mark_inode_dirty(inode);
1474 mutex_unlock(&inode->i_mutex);
1475 return len - towrite;
1480 static struct file_system_type ext2_fs_type = {
1481 .owner = THIS_MODULE,
1483 .mount = ext2_mount,
1484 .kill_sb = kill_block_super,
1485 .fs_flags = FS_REQUIRES_DEV,
1488 static int __init init_ext2_fs(void)
1490 int err = init_ext2_xattr();
1493 err = init_inodecache();
1496 err = register_filesystem(&ext2_fs_type);
1501 destroy_inodecache();
1507 static void __exit exit_ext2_fs(void)
1509 unregister_filesystem(&ext2_fs_type);
1510 destroy_inodecache();
1514 module_init(init_ext2_fs)
1515 module_exit(exit_ext2_fs)