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/config.h>
20 #include <linux/module.h>
21 #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/smp_lock.h>
29 #include <linux/vfs.h>
30 #include <asm/uaccess.h>
35 static void ext2_sync_super(struct super_block *sb,
36 struct ext2_super_block *es);
37 static int ext2_remount (struct super_block * sb, int * flags, char * data);
38 static int ext2_statfs (struct super_block * sb, struct kstatfs * buf);
40 void ext2_error (struct super_block * sb, const char * function,
41 const char * fmt, ...)
44 struct ext2_sb_info *sbi = EXT2_SB(sb);
45 struct ext2_super_block *es = sbi->s_es;
47 if (!(sb->s_flags & MS_RDONLY)) {
48 sbi->s_mount_state |= EXT2_ERROR_FS;
50 cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
51 ext2_sync_super(sb, es);
55 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
60 if (test_opt(sb, ERRORS_PANIC))
61 panic("EXT2-fs panic from previous error\n");
62 if (test_opt(sb, ERRORS_RO)) {
63 printk("Remounting filesystem read-only\n");
64 sb->s_flags |= MS_RDONLY;
68 void ext2_warning (struct super_block * sb, const char * function,
69 const char * fmt, ...)
74 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
81 void ext2_update_dynamic_rev(struct super_block *sb)
83 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
85 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
88 ext2_warning(sb, __FUNCTION__,
89 "updating to rev %d because of new feature flag, "
90 "running e2fsck is recommended",
93 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
94 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
95 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
96 /* leave es->s_feature_*compat flags alone */
97 /* es->s_uuid will be set by e2fsck if empty */
100 * The rest of the superblock fields should be zero, and if not it
101 * means they are likely already in use, so leave them alone. We
102 * can leave it up to e2fsck to clean up any inconsistencies there.
106 static void ext2_put_super (struct super_block * sb)
110 struct ext2_sb_info *sbi = EXT2_SB(sb);
112 ext2_xattr_put_super(sb);
113 if (!(sb->s_flags & MS_RDONLY)) {
114 struct ext2_super_block *es = sbi->s_es;
116 es->s_state = cpu_to_le16(sbi->s_mount_state);
117 ext2_sync_super(sb, es);
119 db_count = sbi->s_gdb_count;
120 for (i = 0; i < db_count; i++)
121 if (sbi->s_group_desc[i])
122 brelse (sbi->s_group_desc[i]);
123 kfree(sbi->s_group_desc);
125 percpu_counter_destroy(&sbi->s_freeblocks_counter);
126 percpu_counter_destroy(&sbi->s_freeinodes_counter);
127 percpu_counter_destroy(&sbi->s_dirs_counter);
129 sb->s_fs_info = NULL;
135 static kmem_cache_t * ext2_inode_cachep;
137 static struct inode *ext2_alloc_inode(struct super_block *sb)
139 struct ext2_inode_info *ei;
140 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, SLAB_KERNEL);
143 #ifdef CONFIG_EXT2_FS_POSIX_ACL
144 ei->i_acl = EXT2_ACL_NOT_CACHED;
145 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
147 ei->vfs_inode.i_version = 1;
148 return &ei->vfs_inode;
151 static void ext2_destroy_inode(struct inode *inode)
153 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
156 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
158 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
160 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
161 SLAB_CTOR_CONSTRUCTOR) {
162 rwlock_init(&ei->i_meta_lock);
163 #ifdef CONFIG_EXT2_FS_XATTR
164 init_rwsem(&ei->xattr_sem);
166 inode_init_once(&ei->vfs_inode);
170 static int init_inodecache(void)
172 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
173 sizeof(struct ext2_inode_info),
174 0, SLAB_RECLAIM_ACCOUNT,
176 if (ext2_inode_cachep == NULL)
181 static void destroy_inodecache(void)
183 if (kmem_cache_destroy(ext2_inode_cachep))
184 printk(KERN_INFO "ext2_inode_cache: not all structures were freed\n");
187 static void ext2_clear_inode(struct inode *inode)
189 #ifdef CONFIG_EXT2_FS_POSIX_ACL
190 struct ext2_inode_info *ei = EXT2_I(inode);
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;
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;
204 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
205 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
208 static struct super_operations ext2_sops = {
209 .alloc_inode = ext2_alloc_inode,
210 .destroy_inode = ext2_destroy_inode,
211 .read_inode = ext2_read_inode,
212 .write_inode = ext2_write_inode,
213 .put_inode = ext2_put_inode,
214 .delete_inode = ext2_delete_inode,
215 .put_super = ext2_put_super,
216 .write_super = ext2_write_super,
217 .statfs = ext2_statfs,
218 .remount_fs = ext2_remount,
219 .clear_inode = ext2_clear_inode,
221 .quota_read = ext2_quota_read,
222 .quota_write = ext2_quota_write,
226 /* Yes, most of these are left as NULL!!
227 * A NULL value implies the default, which works with ext2-like file
228 * systems, but can be improved upon.
229 * Currently only get_parent is required.
231 struct dentry *ext2_get_parent(struct dentry *child);
232 static struct export_operations ext2_export_ops = {
233 .get_parent = ext2_get_parent,
236 static unsigned long get_sb_block(void **data)
238 unsigned long sb_block;
239 char *options = (char *) *data;
241 if (!options || strncmp(options, "sb=", 3) != 0)
242 return 1; /* Default location */
244 sb_block = simple_strtoul(options, &options, 0);
245 if (*options && *options != ',') {
246 printk("EXT2-fs: Invalid sb specification: %s\n",
252 *data = (void *) options;
257 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
258 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
259 Opt_nouid32, Opt_check, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov, Opt_nobh,
260 Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl, Opt_tagxid,
264 static match_table_t tokens = {
265 {Opt_bsd_df, "bsddf"},
266 {Opt_minix_df, "minixdf"},
267 {Opt_grpid, "grpid"},
268 {Opt_grpid, "bsdgroups"},
269 {Opt_nogrpid, "nogrpid"},
270 {Opt_nogrpid, "sysvgroups"},
271 {Opt_resgid, "resgid=%u"},
272 {Opt_resuid, "resuid=%u"},
274 {Opt_err_cont, "errors=continue"},
275 {Opt_err_panic, "errors=panic"},
276 {Opt_err_ro, "errors=remount-ro"},
277 {Opt_nouid32, "nouid32"},
278 {Opt_nocheck, "check=none"},
279 {Opt_nocheck, "nocheck"},
280 {Opt_check, "check"},
281 {Opt_debug, "debug"},
282 {Opt_oldalloc, "oldalloc"},
283 {Opt_orlov, "orlov"},
285 {Opt_user_xattr, "user_xattr"},
286 {Opt_nouser_xattr, "nouser_xattr"},
288 {Opt_noacl, "noacl"},
289 {Opt_tagxid, "tagxid"},
290 {Opt_ignore, "grpquota"},
291 {Opt_ignore, "noquota"},
292 {Opt_ignore, "quota"},
293 {Opt_ignore, "usrquota"},
297 static int parse_options (char * options,
298 struct ext2_sb_info *sbi)
301 substring_t args[MAX_OPT_ARGS];
302 unsigned long kind = EXT2_MOUNT_ERRORS_CONT;
308 while ((p = strsep (&options, ",")) != NULL) {
313 token = match_token(p, tokens, args);
316 clear_opt (sbi->s_mount_opt, MINIX_DF);
319 set_opt (sbi->s_mount_opt, MINIX_DF);
322 set_opt (sbi->s_mount_opt, GRPID);
325 clear_opt (sbi->s_mount_opt, GRPID);
328 if (match_int(&args[0], &option))
330 sbi->s_resuid = option;
333 if (match_int(&args[0], &option))
335 sbi->s_resgid = option;
338 /* handled by get_sb_block() instead of here */
339 /* *sb_block = match_int(&args[0]); */
342 kind = EXT2_MOUNT_ERRORS_PANIC;
345 kind = EXT2_MOUNT_ERRORS_RO;
348 kind = EXT2_MOUNT_ERRORS_CONT;
351 set_opt (sbi->s_mount_opt, NO_UID32);
353 #ifndef CONFIG_INOXID_NONE
355 set_opt (sbi->s_mount_opt, TAG_XID);
359 #ifdef CONFIG_EXT2_CHECK
360 set_opt (sbi->s_mount_opt, CHECK);
362 printk("EXT2 Check option not supported\n");
366 clear_opt (sbi->s_mount_opt, CHECK);
369 set_opt (sbi->s_mount_opt, DEBUG);
372 set_opt (sbi->s_mount_opt, OLDALLOC);
375 clear_opt (sbi->s_mount_opt, OLDALLOC);
378 set_opt (sbi->s_mount_opt, NOBH);
380 #ifdef CONFIG_EXT2_FS_XATTR
382 set_opt (sbi->s_mount_opt, XATTR_USER);
384 case Opt_nouser_xattr:
385 clear_opt (sbi->s_mount_opt, XATTR_USER);
389 case Opt_nouser_xattr:
390 printk("EXT2 (no)user_xattr options not supported\n");
393 #ifdef CONFIG_EXT2_FS_POSIX_ACL
395 set_opt(sbi->s_mount_opt, POSIX_ACL);
398 clear_opt(sbi->s_mount_opt, POSIX_ACL);
403 printk("EXT2 (no)acl options not supported\n");
412 sbi->s_mount_opt |= kind;
416 static int ext2_setup_super (struct super_block * sb,
417 struct ext2_super_block * es,
421 struct ext2_sb_info *sbi = EXT2_SB(sb);
423 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
424 printk ("EXT2-fs warning: revision level too high, "
425 "forcing read-only mode\n");
430 if (!(sbi->s_mount_state & EXT2_VALID_FS))
431 printk ("EXT2-fs warning: mounting unchecked fs, "
432 "running e2fsck is recommended\n");
433 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
434 printk ("EXT2-fs warning: mounting fs with errors, "
435 "running e2fsck is recommended\n");
436 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
437 le16_to_cpu(es->s_mnt_count) >=
438 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
439 printk ("EXT2-fs warning: maximal mount count reached, "
440 "running e2fsck is recommended\n");
441 else if (le32_to_cpu(es->s_checkinterval) &&
442 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
443 printk ("EXT2-fs warning: checktime reached, "
444 "running e2fsck is recommended\n");
445 if (!le16_to_cpu(es->s_max_mnt_count))
446 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
447 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
448 ext2_write_super(sb);
449 if (test_opt (sb, DEBUG))
450 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
451 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
452 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
455 EXT2_BLOCKS_PER_GROUP(sb),
456 EXT2_INODES_PER_GROUP(sb),
458 #ifdef CONFIG_EXT2_CHECK
459 if (test_opt (sb, CHECK)) {
460 ext2_check_blocks_bitmap (sb);
461 ext2_check_inodes_bitmap (sb);
467 static int ext2_check_descriptors (struct super_block * sb)
471 struct ext2_sb_info *sbi = EXT2_SB(sb);
472 unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block);
473 struct ext2_group_desc * gdp = NULL;
475 ext2_debug ("Checking group descriptors");
477 for (i = 0; i < sbi->s_groups_count; i++)
479 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
480 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
481 if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
482 le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
484 ext2_error (sb, "ext2_check_descriptors",
485 "Block bitmap for group %d"
486 " not in group (block %lu)!",
487 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
490 if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
491 le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
493 ext2_error (sb, "ext2_check_descriptors",
494 "Inode bitmap for group %d"
495 " not in group (block %lu)!",
496 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
499 if (le32_to_cpu(gdp->bg_inode_table) < block ||
500 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
501 block + EXT2_BLOCKS_PER_GROUP(sb))
503 ext2_error (sb, "ext2_check_descriptors",
504 "Inode table for group %d"
505 " not in group (block %lu)!",
506 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
509 block += EXT2_BLOCKS_PER_GROUP(sb);
515 #define log2(n) ffz(~(n))
518 * Maximal file size. There is a direct, and {,double-,triple-}indirect
519 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
520 * We need to be 1 filesystem block less than the 2^32 sector limit.
522 static loff_t ext2_max_size(int bits)
524 loff_t res = EXT2_NDIR_BLOCKS;
525 /* This constant is calculated to be the largest file size for a
526 * dense, 4k-blocksize file such that the total number of
527 * sectors in the file, including data and all indirect blocks,
528 * does not exceed 2^32. */
529 const loff_t upper_limit = 0x1ff7fffd000LL;
531 res += 1LL << (bits-2);
532 res += 1LL << (2*(bits-2));
533 res += 1LL << (3*(bits-2));
535 if (res > upper_limit)
540 static unsigned long descriptor_loc(struct super_block *sb,
541 unsigned long logic_sb_block,
544 struct ext2_sb_info *sbi = EXT2_SB(sb);
545 unsigned long bg, first_data_block, first_meta_bg;
548 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
549 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
551 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
553 return (logic_sb_block + nr + 1);
554 bg = sbi->s_desc_per_block * nr;
555 if (ext2_bg_has_super(sb, bg))
557 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
560 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
562 struct buffer_head * bh;
563 struct ext2_sb_info * sbi;
564 struct ext2_super_block * es;
567 unsigned long sb_block = get_sb_block(&data);
568 unsigned long logic_sb_block;
569 unsigned long offset = 0;
570 unsigned long def_mount_opts;
571 int blocksize = BLOCK_SIZE;
576 sbi = kmalloc(sizeof(*sbi), GFP_KERNEL);
580 memset(sbi, 0, sizeof(*sbi));
583 * See what the current blocksize for the device is, and
584 * use that as the blocksize. Otherwise (or if the blocksize
585 * is smaller than the default) use the default.
586 * This is important for devices that have a hardware
587 * sectorsize that is larger than the default.
589 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
591 printk ("EXT2-fs: unable to set blocksize\n");
596 * If the superblock doesn't start on a hardware sector boundary,
597 * calculate the offset.
599 if (blocksize != BLOCK_SIZE) {
600 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
601 offset = (sb_block*BLOCK_SIZE) % blocksize;
603 logic_sb_block = sb_block;
606 if (!(bh = sb_bread(sb, logic_sb_block))) {
607 printk ("EXT2-fs: unable to read superblock\n");
611 * Note: s_es must be initialized as soon as possible because
612 * some ext2 macro-instructions depend on its value
614 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
616 sb->s_magic = le16_to_cpu(es->s_magic);
618 if (sb->s_magic != EXT2_SUPER_MAGIC)
621 /* Set defaults before we parse the mount options */
622 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
623 if (def_mount_opts & EXT2_DEFM_DEBUG)
624 set_opt(sbi->s_mount_opt, DEBUG);
625 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
626 set_opt(sbi->s_mount_opt, GRPID);
627 if (def_mount_opts & EXT2_DEFM_UID16)
628 set_opt(sbi->s_mount_opt, NO_UID32);
629 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
630 set_opt(sbi->s_mount_opt, XATTR_USER);
631 if (def_mount_opts & EXT2_DEFM_ACL)
632 set_opt(sbi->s_mount_opt, POSIX_ACL);
634 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
635 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
636 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
637 set_opt(sbi->s_mount_opt, ERRORS_RO);
639 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
640 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
642 if (!parse_options ((char *) data, sbi))
645 if (EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_TAG_XID)
646 sb->s_flags |= MS_TAGXID;
647 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
648 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
651 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
652 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
653 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
654 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
655 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
656 "running e2fsck is recommended\n");
658 * Check feature flags regardless of the revision level, since we
659 * previously didn't change the revision level when setting the flags,
660 * so there is a chance incompat flags are set on a rev 0 filesystem.
662 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
664 printk("EXT2-fs: %s: couldn't mount because of "
665 "unsupported optional features (%x).\n",
666 sb->s_id, le32_to_cpu(features));
669 if (!(sb->s_flags & MS_RDONLY) &&
670 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
671 printk("EXT2-fs: %s: couldn't mount RDWR because of "
672 "unsupported optional features (%x).\n",
673 sb->s_id, le32_to_cpu(features));
677 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
679 /* If the blocksize doesn't match, re-read the thing.. */
680 if (sb->s_blocksize != blocksize) {
683 if (!sb_set_blocksize(sb, blocksize)) {
684 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
688 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
689 offset = (sb_block*BLOCK_SIZE) % blocksize;
690 bh = sb_bread(sb, logic_sb_block);
692 printk("EXT2-fs: Couldn't read superblock on "
696 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
698 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
699 printk ("EXT2-fs: Magic mismatch, very weird !\n");
704 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
706 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
707 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
708 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
710 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
711 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
712 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
713 (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
714 (sbi->s_inode_size > blocksize)) {
715 printk ("EXT2-fs: unsupported inode size: %d\n",
721 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
722 le32_to_cpu(es->s_log_frag_size);
723 if (sbi->s_frag_size == 0)
725 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
727 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
728 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
729 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
731 if (EXT2_INODE_SIZE(sb) == 0)
733 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
734 if (sbi->s_inodes_per_block == 0)
736 sbi->s_itb_per_group = sbi->s_inodes_per_group /
737 sbi->s_inodes_per_block;
738 sbi->s_desc_per_block = sb->s_blocksize /
739 sizeof (struct ext2_group_desc);
741 sbi->s_mount_state = le16_to_cpu(es->s_state);
742 sbi->s_addr_per_block_bits =
743 log2 (EXT2_ADDR_PER_BLOCK(sb));
744 sbi->s_desc_per_block_bits =
745 log2 (EXT2_DESC_PER_BLOCK(sb));
747 if (sb->s_magic != EXT2_SUPER_MAGIC)
750 if (sb->s_blocksize != bh->b_size) {
752 printk ("VFS: Unsupported blocksize on dev "
757 if (sb->s_blocksize != sbi->s_frag_size) {
758 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
759 sbi->s_frag_size, sb->s_blocksize);
763 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
764 printk ("EXT2-fs: #blocks per group too big: %lu\n",
765 sbi->s_blocks_per_group);
768 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
769 printk ("EXT2-fs: #fragments per group too big: %lu\n",
770 sbi->s_frags_per_group);
773 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
774 printk ("EXT2-fs: #inodes per group too big: %lu\n",
775 sbi->s_inodes_per_group);
779 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
781 sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
782 le32_to_cpu(es->s_first_data_block) +
783 EXT2_BLOCKS_PER_GROUP(sb) - 1) /
784 EXT2_BLOCKS_PER_GROUP(sb);
785 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
786 EXT2_DESC_PER_BLOCK(sb);
787 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
788 if (sbi->s_group_desc == NULL) {
789 printk ("EXT2-fs: not enough memory\n");
792 percpu_counter_init(&sbi->s_freeblocks_counter);
793 percpu_counter_init(&sbi->s_freeinodes_counter);
794 percpu_counter_init(&sbi->s_dirs_counter);
795 bgl_lock_init(&sbi->s_blockgroup_lock);
796 sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts),
799 printk ("EXT2-fs: not enough memory\n");
800 goto failed_mount_group_desc;
802 memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts));
803 for (i = 0; i < db_count; i++) {
804 block = descriptor_loc(sb, logic_sb_block, i);
805 sbi->s_group_desc[i] = sb_bread(sb, block);
806 if (!sbi->s_group_desc[i]) {
807 for (j = 0; j < i; j++)
808 brelse (sbi->s_group_desc[j]);
809 printk ("EXT2-fs: unable to read group descriptors\n");
810 goto failed_mount_group_desc;
813 if (!ext2_check_descriptors (sb)) {
814 printk ("EXT2-fs: group descriptors corrupted!\n");
818 sbi->s_gdb_count = db_count;
819 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
820 spin_lock_init(&sbi->s_next_gen_lock);
822 * set up enough so that it can read an inode
824 sb->s_op = &ext2_sops;
825 sb->s_export_op = &ext2_export_ops;
826 sb->s_xattr = ext2_xattr_handlers;
827 root = iget(sb, EXT2_ROOT_INO);
828 sb->s_root = d_alloc_root(root);
831 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
834 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
837 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
840 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
841 ext2_warning(sb, __FUNCTION__,
842 "mounting ext3 filesystem as ext2\n");
843 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
844 percpu_counter_mod(&sbi->s_freeblocks_counter,
845 ext2_count_free_blocks(sb));
846 percpu_counter_mod(&sbi->s_freeinodes_counter,
847 ext2_count_free_inodes(sb));
848 percpu_counter_mod(&sbi->s_dirs_counter,
849 ext2_count_dirs(sb));
854 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
859 for (i = 0; i < db_count; i++)
860 brelse(sbi->s_group_desc[i]);
861 failed_mount_group_desc:
862 kfree(sbi->s_group_desc);
867 sb->s_fs_info = NULL;
872 static void ext2_commit_super (struct super_block * sb,
873 struct ext2_super_block * es)
875 es->s_wtime = cpu_to_le32(get_seconds());
876 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
880 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
882 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
883 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
884 es->s_wtime = cpu_to_le32(get_seconds());
885 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
886 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
891 * In the second extended file system, it is not necessary to
892 * write the super block since we use a mapping of the
893 * disk super block in a buffer.
895 * However, this function is still used to set the fs valid
896 * flags to 0. We need to set this flag to 0 since the fs
897 * may have been checked while mounted and e2fsck may have
898 * set s_state to EXT2_VALID_FS after some corrections.
901 void ext2_write_super (struct super_block * sb)
903 struct ext2_super_block * es;
905 if (!(sb->s_flags & MS_RDONLY)) {
906 es = EXT2_SB(sb)->s_es;
908 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
909 ext2_debug ("setting valid to 0\n");
910 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
912 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
913 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
914 es->s_mtime = cpu_to_le32(get_seconds());
915 ext2_sync_super(sb, es);
917 ext2_commit_super (sb, es);
923 static int ext2_remount (struct super_block * sb, int * flags, char * data)
925 struct ext2_sb_info * sbi = EXT2_SB(sb);
926 struct ext2_super_block * es;
929 * Allow the "check" option to be passed as a remount option.
931 if (!parse_options (data, sbi))
934 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
935 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
938 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
940 if (*flags & MS_RDONLY) {
941 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
942 !(sbi->s_mount_state & EXT2_VALID_FS))
945 * OK, we are remounting a valid rw partition rdonly, so set
946 * the rdonly flag and then mark the partition as valid again.
948 es->s_state = cpu_to_le16(sbi->s_mount_state);
949 es->s_mtime = cpu_to_le32(get_seconds());
951 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
952 ~EXT2_FEATURE_RO_COMPAT_SUPP);
954 printk("EXT2-fs: %s: couldn't remount RDWR because of "
955 "unsupported optional features (%x).\n",
956 sb->s_id, le32_to_cpu(ret));
960 * Mounting a RDONLY partition read-write, so reread and
961 * store the current valid flag. (It may have been changed
962 * by e2fsck since we originally mounted the partition.)
964 sbi->s_mount_state = le16_to_cpu(es->s_state);
965 if (!ext2_setup_super (sb, es, 0))
966 sb->s_flags &= ~MS_RDONLY;
968 ext2_sync_super(sb, es);
972 static int ext2_statfs (struct super_block * sb, struct kstatfs * buf)
974 struct ext2_sb_info *sbi = EXT2_SB(sb);
975 unsigned long overhead;
978 if (test_opt (sb, MINIX_DF))
982 * Compute the overhead (FS structures)
986 * All of the blocks before first_data_block are
989 overhead = le32_to_cpu(sbi->s_es->s_first_data_block);
992 * Add the overhead attributed to the superblock and
993 * block group descriptors. If the sparse superblocks
994 * feature is turned on, then not all groups have this.
996 for (i = 0; i < sbi->s_groups_count; i++)
997 overhead += ext2_bg_has_super(sb, i) +
998 ext2_bg_num_gdb(sb, i);
1001 * Every block group has an inode bitmap, a block
1002 * bitmap, and an inode table.
1004 overhead += (sbi->s_groups_count *
1005 (2 + sbi->s_itb_per_group));
1008 buf->f_type = EXT2_SUPER_MAGIC;
1009 buf->f_bsize = sb->s_blocksize;
1010 buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead;
1011 buf->f_bfree = ext2_count_free_blocks(sb);
1012 buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count);
1013 if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count))
1015 buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count);
1016 buf->f_ffree = ext2_count_free_inodes (sb);
1017 buf->f_namelen = EXT2_NAME_LEN;
1021 static struct super_block *ext2_get_sb(struct file_system_type *fs_type,
1022 int flags, const char *dev_name, void *data)
1024 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1029 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1030 * acquiring the locks... As quota files are never truncated and quota code
1031 * itself serializes the operations (and noone else should touch the files)
1032 * we don't have to be afraid of races */
1033 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1034 size_t len, loff_t off)
1036 struct inode *inode = sb_dqopt(sb)->files[type];
1037 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1039 int offset = off & (sb->s_blocksize - 1);
1042 struct buffer_head tmp_bh;
1043 struct buffer_head *bh;
1044 loff_t i_size = i_size_read(inode);
1048 if (off+len > i_size)
1051 while (toread > 0) {
1052 tocopy = sb->s_blocksize - offset < toread ?
1053 sb->s_blocksize - offset : toread;
1056 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1059 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1060 memset(data, 0, tocopy);
1062 bh = sb_bread(sb, tmp_bh.b_blocknr);
1065 memcpy(data, bh->b_data+offset, tocopy);
1076 /* Write to quotafile */
1077 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1078 const char *data, size_t len, loff_t off)
1080 struct inode *inode = sb_dqopt(sb)->files[type];
1081 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1083 int offset = off & (sb->s_blocksize - 1);
1085 size_t towrite = len;
1086 struct buffer_head tmp_bh;
1087 struct buffer_head *bh;
1089 down(&inode->i_sem);
1090 while (towrite > 0) {
1091 tocopy = sb->s_blocksize - offset < towrite ?
1092 sb->s_blocksize - offset : towrite;
1095 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1098 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1099 bh = sb_bread(sb, tmp_bh.b_blocknr);
1101 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1107 memcpy(bh->b_data+offset, data, tocopy);
1108 flush_dcache_page(bh->b_page);
1109 set_buffer_uptodate(bh);
1110 mark_buffer_dirty(bh);
1121 if (inode->i_size < off+len-towrite)
1122 i_size_write(inode, off+len-towrite);
1124 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1125 mark_inode_dirty(inode);
1127 return len - towrite;
1132 static struct file_system_type ext2_fs_type = {
1133 .owner = THIS_MODULE,
1135 .get_sb = ext2_get_sb,
1136 .kill_sb = kill_block_super,
1137 .fs_flags = FS_REQUIRES_DEV,
1140 static int __init init_ext2_fs(void)
1142 int err = init_ext2_xattr();
1145 err = init_inodecache();
1148 err = register_filesystem(&ext2_fs_type);
1153 destroy_inodecache();
1159 static void __exit exit_ext2_fs(void)
1161 unregister_filesystem(&ext2_fs_type);
1162 destroy_inodecache();
1166 module_init(init_ext2_fs)
1167 module_exit(exit_ext2_fs)