1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/fs/ext2/super.c
5 * Copyright (C) 1992, 1993, 1994, 1995
6 * Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
12 * linux/fs/minix/inode.c
14 * Copyright (C) 1991, 1992 Linus Torvalds
16 * Big-endian to little-endian byte-swapping/bitmaps by
17 * David S. Miller (davem@caip.rutgers.edu), 1995
20 #include <linux/module.h>
21 #include <linux/string.h>
23 #include <linux/slab.h>
24 #include <linux/init.h>
25 #include <linux/blkdev.h>
26 #include <linux/parser.h>
27 #include <linux/random.h>
28 #include <linux/buffer_head.h>
29 #include <linux/exportfs.h>
30 #include <linux/vfs.h>
31 #include <linux/seq_file.h>
32 #include <linux/mount.h>
33 #include <linux/log2.h>
34 #include <linux/quotaops.h>
35 #include <linux/uaccess.h>
36 #include <linux/dax.h>
37 #include <linux/iversion.h>
42 static void ext2_write_super(struct super_block *sb);
43 static int ext2_remount (struct super_block * sb, int * flags, char * data);
44 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
45 static int ext2_sync_fs(struct super_block *sb, int wait);
46 static int ext2_freeze(struct super_block *sb);
47 static int ext2_unfreeze(struct super_block *sb);
49 void ext2_error(struct super_block *sb, const char *function,
54 struct ext2_sb_info *sbi = EXT2_SB(sb);
55 struct ext2_super_block *es = sbi->s_es;
58 spin_lock(&sbi->s_lock);
59 sbi->s_mount_state |= EXT2_ERROR_FS;
60 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
61 spin_unlock(&sbi->s_lock);
62 ext2_sync_super(sb, es, 1);
70 printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
71 sb->s_id, function, &vaf);
75 if (test_opt(sb, ERRORS_PANIC))
76 panic("EXT2-fs: panic from previous error\n");
77 if (!sb_rdonly(sb) && test_opt(sb, ERRORS_RO)) {
78 ext2_msg(sb, KERN_CRIT,
79 "error: remounting filesystem read-only");
80 sb->s_flags |= SB_RDONLY;
84 void ext2_msg(struct super_block *sb, const char *prefix,
95 printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
101 * This must be called with sbi->s_lock held.
103 void ext2_update_dynamic_rev(struct super_block *sb)
105 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
107 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
110 ext2_msg(sb, KERN_WARNING,
111 "warning: updating to rev %d because of "
112 "new feature flag, running e2fsck is recommended",
115 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
116 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
117 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
118 /* leave es->s_feature_*compat flags alone */
119 /* es->s_uuid will be set by e2fsck if empty */
122 * The rest of the superblock fields should be zero, and if not it
123 * means they are likely already in use, so leave them alone. We
124 * can leave it up to e2fsck to clean up any inconsistencies there.
129 static int ext2_quota_off(struct super_block *sb, int type);
131 static void ext2_quota_off_umount(struct super_block *sb)
135 for (type = 0; type < MAXQUOTAS; type++)
136 ext2_quota_off(sb, type);
139 static inline void ext2_quota_off_umount(struct super_block *sb)
144 static void ext2_put_super (struct super_block * sb)
148 struct ext2_sb_info *sbi = EXT2_SB(sb);
150 ext2_quota_off_umount(sb);
152 ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
153 sbi->s_ea_block_cache = NULL;
155 if (!sb_rdonly(sb)) {
156 struct ext2_super_block *es = sbi->s_es;
158 spin_lock(&sbi->s_lock);
159 es->s_state = cpu_to_le16(sbi->s_mount_state);
160 spin_unlock(&sbi->s_lock);
161 ext2_sync_super(sb, es, 1);
163 db_count = sbi->s_gdb_count;
164 for (i = 0; i < db_count; i++)
165 brelse(sbi->s_group_desc[i]);
166 kfree(sbi->s_group_desc);
168 percpu_counter_destroy(&sbi->s_freeblocks_counter);
169 percpu_counter_destroy(&sbi->s_freeinodes_counter);
170 percpu_counter_destroy(&sbi->s_dirs_counter);
172 sb->s_fs_info = NULL;
173 kfree(sbi->s_blockgroup_lock);
174 fs_put_dax(sbi->s_daxdev);
178 static struct kmem_cache * ext2_inode_cachep;
180 static struct inode *ext2_alloc_inode(struct super_block *sb)
182 struct ext2_inode_info *ei;
183 ei = alloc_inode_sb(sb, ext2_inode_cachep, GFP_KERNEL);
186 ei->i_block_alloc_info = NULL;
187 inode_set_iversion(&ei->vfs_inode, 1);
189 memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
192 return &ei->vfs_inode;
195 static void ext2_free_in_core_inode(struct inode *inode)
197 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
200 static void init_once(void *foo)
202 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
204 rwlock_init(&ei->i_meta_lock);
205 #ifdef CONFIG_EXT2_FS_XATTR
206 init_rwsem(&ei->xattr_sem);
208 mutex_init(&ei->truncate_mutex);
209 inode_init_once(&ei->vfs_inode);
212 static int __init init_inodecache(void)
214 ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
215 sizeof(struct ext2_inode_info), 0,
216 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
218 offsetof(struct ext2_inode_info, i_data),
219 sizeof_field(struct ext2_inode_info, i_data),
221 if (ext2_inode_cachep == NULL)
226 static void destroy_inodecache(void)
229 * Make sure all delayed rcu free inodes are flushed before we
233 kmem_cache_destroy(ext2_inode_cachep);
236 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
238 struct super_block *sb = root->d_sb;
239 struct ext2_sb_info *sbi = EXT2_SB(sb);
240 struct ext2_super_block *es = sbi->s_es;
241 unsigned long def_mount_opts;
243 spin_lock(&sbi->s_lock);
244 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
246 if (sbi->s_sb_block != 1)
247 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
248 if (test_opt(sb, MINIX_DF))
249 seq_puts(seq, ",minixdf");
250 if (test_opt(sb, GRPID))
251 seq_puts(seq, ",grpid");
252 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
253 seq_puts(seq, ",nogrpid");
254 if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
255 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
256 seq_printf(seq, ",resuid=%u",
257 from_kuid_munged(&init_user_ns, sbi->s_resuid));
259 if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
260 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
261 seq_printf(seq, ",resgid=%u",
262 from_kgid_munged(&init_user_ns, sbi->s_resgid));
264 if (test_opt(sb, ERRORS_RO)) {
265 int def_errors = le16_to_cpu(es->s_errors);
267 if (def_errors == EXT2_ERRORS_PANIC ||
268 def_errors == EXT2_ERRORS_CONTINUE) {
269 seq_puts(seq, ",errors=remount-ro");
272 if (test_opt(sb, ERRORS_CONT))
273 seq_puts(seq, ",errors=continue");
274 if (test_opt(sb, ERRORS_PANIC))
275 seq_puts(seq, ",errors=panic");
276 if (test_opt(sb, NO_UID32))
277 seq_puts(seq, ",nouid32");
278 if (test_opt(sb, DEBUG))
279 seq_puts(seq, ",debug");
280 if (test_opt(sb, OLDALLOC))
281 seq_puts(seq, ",oldalloc");
283 #ifdef CONFIG_EXT2_FS_XATTR
284 if (test_opt(sb, XATTR_USER))
285 seq_puts(seq, ",user_xattr");
286 if (!test_opt(sb, XATTR_USER) &&
287 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
288 seq_puts(seq, ",nouser_xattr");
292 #ifdef CONFIG_EXT2_FS_POSIX_ACL
293 if (test_opt(sb, POSIX_ACL))
294 seq_puts(seq, ",acl");
295 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
296 seq_puts(seq, ",noacl");
299 if (test_opt(sb, USRQUOTA))
300 seq_puts(seq, ",usrquota");
302 if (test_opt(sb, GRPQUOTA))
303 seq_puts(seq, ",grpquota");
305 if (test_opt(sb, XIP))
306 seq_puts(seq, ",xip");
308 if (test_opt(sb, DAX))
309 seq_puts(seq, ",dax");
311 if (!test_opt(sb, RESERVATION))
312 seq_puts(seq, ",noreservation");
314 spin_unlock(&sbi->s_lock);
319 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
320 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
321 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
322 const struct path *path);
323 static struct dquot **ext2_get_dquots(struct inode *inode)
325 return EXT2_I(inode)->i_dquot;
328 static const struct quotactl_ops ext2_quotactl_ops = {
329 .quota_on = ext2_quota_on,
330 .quota_off = ext2_quota_off,
331 .quota_sync = dquot_quota_sync,
332 .get_state = dquot_get_state,
333 .set_info = dquot_set_dqinfo,
334 .get_dqblk = dquot_get_dqblk,
335 .set_dqblk = dquot_set_dqblk,
336 .get_nextdqblk = dquot_get_next_dqblk,
340 static const struct super_operations ext2_sops = {
341 .alloc_inode = ext2_alloc_inode,
342 .free_inode = ext2_free_in_core_inode,
343 .write_inode = ext2_write_inode,
344 .evict_inode = ext2_evict_inode,
345 .put_super = ext2_put_super,
346 .sync_fs = ext2_sync_fs,
347 .freeze_fs = ext2_freeze,
348 .unfreeze_fs = ext2_unfreeze,
349 .statfs = ext2_statfs,
350 .remount_fs = ext2_remount,
351 .show_options = ext2_show_options,
353 .quota_read = ext2_quota_read,
354 .quota_write = ext2_quota_write,
355 .get_dquots = ext2_get_dquots,
359 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
360 u64 ino, u32 generation)
364 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
365 return ERR_PTR(-ESTALE);
366 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
367 return ERR_PTR(-ESTALE);
370 * ext2_iget isn't quite right if the inode is currently unallocated!
371 * However ext2_iget currently does appropriate checks to handle stale
372 * inodes so everything is OK.
374 inode = ext2_iget(sb, ino);
376 return ERR_CAST(inode);
377 if (generation && inode->i_generation != generation) {
378 /* we didn't find the right inode.. */
380 return ERR_PTR(-ESTALE);
385 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
386 int fh_len, int fh_type)
388 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
392 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
393 int fh_len, int fh_type)
395 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
399 static const struct export_operations ext2_export_ops = {
400 .fh_to_dentry = ext2_fh_to_dentry,
401 .fh_to_parent = ext2_fh_to_parent,
402 .get_parent = ext2_get_parent,
405 static unsigned long get_sb_block(void **data)
407 unsigned long sb_block;
408 char *options = (char *) *data;
410 if (!options || strncmp(options, "sb=", 3) != 0)
411 return 1; /* Default location */
413 sb_block = simple_strtoul(options, &options, 0);
414 if (*options && *options != ',') {
415 printk("EXT2-fs: Invalid sb specification: %s\n",
421 *data = (void *) options;
426 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
427 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
428 Opt_err_ro, Opt_nouid32, Opt_debug,
429 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
430 Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
431 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
434 static const match_table_t tokens = {
435 {Opt_bsd_df, "bsddf"},
436 {Opt_minix_df, "minixdf"},
437 {Opt_grpid, "grpid"},
438 {Opt_grpid, "bsdgroups"},
439 {Opt_nogrpid, "nogrpid"},
440 {Opt_nogrpid, "sysvgroups"},
441 {Opt_resgid, "resgid=%u"},
442 {Opt_resuid, "resuid=%u"},
444 {Opt_err_cont, "errors=continue"},
445 {Opt_err_panic, "errors=panic"},
446 {Opt_err_ro, "errors=remount-ro"},
447 {Opt_nouid32, "nouid32"},
448 {Opt_debug, "debug"},
449 {Opt_oldalloc, "oldalloc"},
450 {Opt_orlov, "orlov"},
452 {Opt_user_xattr, "user_xattr"},
453 {Opt_nouser_xattr, "nouser_xattr"},
455 {Opt_noacl, "noacl"},
458 {Opt_grpquota, "grpquota"},
459 {Opt_ignore, "noquota"},
460 {Opt_quota, "quota"},
461 {Opt_usrquota, "usrquota"},
462 {Opt_reservation, "reservation"},
463 {Opt_noreservation, "noreservation"},
467 static int parse_options(char *options, struct super_block *sb,
468 struct ext2_mount_options *opts)
471 substring_t args[MAX_OPT_ARGS];
479 while ((p = strsep (&options, ",")) != NULL) {
484 token = match_token(p, tokens, args);
487 clear_opt (opts->s_mount_opt, MINIX_DF);
490 set_opt (opts->s_mount_opt, MINIX_DF);
493 set_opt (opts->s_mount_opt, GRPID);
496 clear_opt (opts->s_mount_opt, GRPID);
499 if (match_int(&args[0], &option))
501 uid = make_kuid(current_user_ns(), option);
502 if (!uid_valid(uid)) {
503 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
507 opts->s_resuid = uid;
510 if (match_int(&args[0], &option))
512 gid = make_kgid(current_user_ns(), option);
513 if (!gid_valid(gid)) {
514 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
517 opts->s_resgid = gid;
520 /* handled by get_sb_block() instead of here */
521 /* *sb_block = match_int(&args[0]); */
524 clear_opt (opts->s_mount_opt, ERRORS_CONT);
525 clear_opt (opts->s_mount_opt, ERRORS_RO);
526 set_opt (opts->s_mount_opt, ERRORS_PANIC);
529 clear_opt (opts->s_mount_opt, ERRORS_CONT);
530 clear_opt (opts->s_mount_opt, ERRORS_PANIC);
531 set_opt (opts->s_mount_opt, ERRORS_RO);
534 clear_opt (opts->s_mount_opt, ERRORS_RO);
535 clear_opt (opts->s_mount_opt, ERRORS_PANIC);
536 set_opt (opts->s_mount_opt, ERRORS_CONT);
539 set_opt (opts->s_mount_opt, NO_UID32);
542 set_opt (opts->s_mount_opt, DEBUG);
545 set_opt (opts->s_mount_opt, OLDALLOC);
548 clear_opt (opts->s_mount_opt, OLDALLOC);
551 ext2_msg(sb, KERN_INFO,
552 "nobh option not supported");
554 #ifdef CONFIG_EXT2_FS_XATTR
556 set_opt (opts->s_mount_opt, XATTR_USER);
558 case Opt_nouser_xattr:
559 clear_opt (opts->s_mount_opt, XATTR_USER);
563 case Opt_nouser_xattr:
564 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
568 #ifdef CONFIG_EXT2_FS_POSIX_ACL
570 set_opt(opts->s_mount_opt, POSIX_ACL);
573 clear_opt(opts->s_mount_opt, POSIX_ACL);
578 ext2_msg(sb, KERN_INFO,
579 "(no)acl options not supported");
583 ext2_msg(sb, KERN_INFO, "use dax instead of xip");
584 set_opt(opts->s_mount_opt, XIP);
588 ext2_msg(sb, KERN_WARNING,
589 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
590 set_opt(opts->s_mount_opt, DAX);
592 ext2_msg(sb, KERN_INFO, "dax option not supported");
596 #if defined(CONFIG_QUOTA)
599 set_opt(opts->s_mount_opt, USRQUOTA);
603 set_opt(opts->s_mount_opt, GRPQUOTA);
609 ext2_msg(sb, KERN_INFO,
610 "quota operations not supported");
614 case Opt_reservation:
615 set_opt(opts->s_mount_opt, RESERVATION);
616 ext2_msg(sb, KERN_INFO, "reservations ON");
618 case Opt_noreservation:
619 clear_opt(opts->s_mount_opt, RESERVATION);
620 ext2_msg(sb, KERN_INFO, "reservations OFF");
631 static int ext2_setup_super (struct super_block * sb,
632 struct ext2_super_block * es,
636 struct ext2_sb_info *sbi = EXT2_SB(sb);
638 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
639 ext2_msg(sb, KERN_ERR,
640 "error: revision level too high, "
641 "forcing read-only mode");
646 if (!(sbi->s_mount_state & EXT2_VALID_FS))
647 ext2_msg(sb, KERN_WARNING,
648 "warning: mounting unchecked fs, "
649 "running e2fsck is recommended");
650 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
651 ext2_msg(sb, KERN_WARNING,
652 "warning: mounting fs with errors, "
653 "running e2fsck is recommended");
654 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
655 le16_to_cpu(es->s_mnt_count) >=
656 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
657 ext2_msg(sb, KERN_WARNING,
658 "warning: maximal mount count reached, "
659 "running e2fsck is recommended");
660 else if (le32_to_cpu(es->s_checkinterval) &&
661 (le32_to_cpu(es->s_lastcheck) +
662 le32_to_cpu(es->s_checkinterval) <=
663 ktime_get_real_seconds()))
664 ext2_msg(sb, KERN_WARNING,
665 "warning: checktime reached, "
666 "running e2fsck is recommended");
667 if (!le16_to_cpu(es->s_max_mnt_count))
668 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
669 le16_add_cpu(&es->s_mnt_count, 1);
670 if (test_opt (sb, DEBUG))
671 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
672 "bpg=%lu, ipg=%lu, mo=%04lx]",
673 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
676 EXT2_BLOCKS_PER_GROUP(sb),
677 EXT2_INODES_PER_GROUP(sb),
682 static int ext2_check_descriptors(struct super_block *sb)
685 struct ext2_sb_info *sbi = EXT2_SB(sb);
687 ext2_debug ("Checking group descriptors");
689 for (i = 0; i < sbi->s_groups_count; i++) {
690 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
691 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
692 ext2_fsblk_t last_block = ext2_group_last_block_no(sb, i);
694 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
695 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
697 ext2_error (sb, "ext2_check_descriptors",
698 "Block bitmap for group %d"
699 " not in group (block %lu)!",
700 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
703 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
704 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
706 ext2_error (sb, "ext2_check_descriptors",
707 "Inode bitmap for group %d"
708 " not in group (block %lu)!",
709 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
712 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
713 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
716 ext2_error (sb, "ext2_check_descriptors",
717 "Inode table for group %d"
718 " not in group (block %lu)!",
719 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
727 * Maximal file size. There is a direct, and {,double-,triple-}indirect
728 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
729 * We need to be 1 filesystem block less than the 2^32 sector limit.
731 static loff_t ext2_max_size(int bits)
733 loff_t res = EXT2_NDIR_BLOCKS;
735 unsigned int upper_limit;
736 unsigned int ppb = 1 << (bits-2);
738 /* This is calculated to be the largest file size for a
739 * dense, file such that the total number of
740 * sectors in the file, including data and all indirect blocks,
741 * does not exceed 2^32 -1
742 * __u32 i_blocks representing the total number of
743 * 512 bytes blocks of the file
745 upper_limit = (1LL << 32) - 1;
747 /* total blocks in file system block size */
748 upper_limit >>= (bits - 9);
750 /* Compute how many blocks we can address by block tree */
751 res += 1LL << (bits-2);
752 res += 1LL << (2*(bits-2));
753 res += 1LL << (3*(bits-2));
754 /* Compute how many metadata blocks are needed */
756 meta_blocks += 1 + ppb;
757 meta_blocks += 1 + ppb + ppb * ppb;
758 /* Does block tree limit file size? */
759 if (res + meta_blocks <= upper_limit)
763 /* How many metadata blocks are needed for addressing upper_limit? */
764 upper_limit -= EXT2_NDIR_BLOCKS;
765 /* indirect blocks */
768 /* double indirect blocks */
769 if (upper_limit < ppb * ppb) {
770 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
774 meta_blocks += 1 + ppb;
775 upper_limit -= ppb * ppb;
776 /* tripple indirect blocks for the rest */
777 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
778 DIV_ROUND_UP(upper_limit, ppb*ppb);
782 if (res > MAX_LFS_FILESIZE)
783 res = MAX_LFS_FILESIZE;
788 static unsigned long descriptor_loc(struct super_block *sb,
789 unsigned long logic_sb_block,
792 struct ext2_sb_info *sbi = EXT2_SB(sb);
793 unsigned long bg, first_meta_bg;
795 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
797 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
799 return (logic_sb_block + nr + 1);
800 bg = sbi->s_desc_per_block * nr;
802 return ext2_group_first_block_no(sb, bg) + ext2_bg_has_super(sb, bg);
805 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
807 struct buffer_head * bh;
808 struct ext2_sb_info * sbi;
809 struct ext2_super_block * es;
812 unsigned long sb_block = get_sb_block(&data);
813 unsigned long logic_sb_block;
814 unsigned long offset = 0;
815 unsigned long def_mount_opts;
817 int blocksize = BLOCK_SIZE;
822 struct ext2_mount_options opts;
824 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
828 sbi->s_blockgroup_lock =
829 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
830 if (!sbi->s_blockgroup_lock) {
835 sbi->s_sb_block = sb_block;
836 sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off);
838 spin_lock_init(&sbi->s_lock);
842 * See what the current blocksize for the device is, and
843 * use that as the blocksize. Otherwise (or if the blocksize
844 * is smaller than the default) use the default.
845 * This is important for devices that have a hardware
846 * sectorsize that is larger than the default.
848 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
850 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
855 * If the superblock doesn't start on a hardware sector boundary,
856 * calculate the offset.
858 if (blocksize != BLOCK_SIZE) {
859 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
860 offset = (sb_block*BLOCK_SIZE) % blocksize;
862 logic_sb_block = sb_block;
865 if (!(bh = sb_bread(sb, logic_sb_block))) {
866 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
870 * Note: s_es must be initialized as soon as possible because
871 * some ext2 macro-instructions depend on its value
873 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
875 sb->s_magic = le16_to_cpu(es->s_magic);
877 if (sb->s_magic != EXT2_SUPER_MAGIC)
880 opts.s_mount_opt = 0;
881 /* Set defaults before we parse the mount options */
882 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
883 if (def_mount_opts & EXT2_DEFM_DEBUG)
884 set_opt(opts.s_mount_opt, DEBUG);
885 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
886 set_opt(opts.s_mount_opt, GRPID);
887 if (def_mount_opts & EXT2_DEFM_UID16)
888 set_opt(opts.s_mount_opt, NO_UID32);
889 #ifdef CONFIG_EXT2_FS_XATTR
890 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
891 set_opt(opts.s_mount_opt, XATTR_USER);
893 #ifdef CONFIG_EXT2_FS_POSIX_ACL
894 if (def_mount_opts & EXT2_DEFM_ACL)
895 set_opt(opts.s_mount_opt, POSIX_ACL);
898 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
899 set_opt(opts.s_mount_opt, ERRORS_PANIC);
900 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
901 set_opt(opts.s_mount_opt, ERRORS_CONT);
903 set_opt(opts.s_mount_opt, ERRORS_RO);
905 opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
906 opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
908 set_opt(opts.s_mount_opt, RESERVATION);
910 if (!parse_options((char *) data, sb, &opts))
913 sbi->s_mount_opt = opts.s_mount_opt;
914 sbi->s_resuid = opts.s_resuid;
915 sbi->s_resgid = opts.s_resgid;
917 sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
918 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
919 sb->s_iflags |= SB_I_CGROUPWB;
921 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
922 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
923 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
924 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
925 ext2_msg(sb, KERN_WARNING,
926 "warning: feature flags set on rev 0 fs, "
927 "running e2fsck is recommended");
929 * Check feature flags regardless of the revision level, since we
930 * previously didn't change the revision level when setting the flags,
931 * so there is a chance incompat flags are set on a rev 0 filesystem.
933 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
935 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
936 "unsupported optional features (%x)",
937 le32_to_cpu(features));
940 if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
941 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
942 "unsupported optional features (%x)",
943 le32_to_cpu(features));
947 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
949 if (test_opt(sb, DAX)) {
950 if (!sbi->s_daxdev) {
951 ext2_msg(sb, KERN_ERR,
952 "DAX unsupported by block device. Turning off DAX.");
953 clear_opt(sbi->s_mount_opt, DAX);
954 } else if (blocksize != PAGE_SIZE) {
955 ext2_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
956 clear_opt(sbi->s_mount_opt, DAX);
960 /* If the blocksize doesn't match, re-read the thing.. */
961 if (sb->s_blocksize != blocksize) {
964 if (!sb_set_blocksize(sb, blocksize)) {
965 ext2_msg(sb, KERN_ERR,
966 "error: bad blocksize %d", blocksize);
970 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
971 offset = (sb_block*BLOCK_SIZE) % blocksize;
972 bh = sb_bread(sb, logic_sb_block);
974 ext2_msg(sb, KERN_ERR, "error: couldn't read"
975 "superblock on 2nd try");
978 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
980 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
981 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
986 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
987 sb->s_max_links = EXT2_LINK_MAX;
988 sb->s_time_min = S32_MIN;
989 sb->s_time_max = S32_MAX;
991 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
992 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
993 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
995 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
996 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
997 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
998 !is_power_of_2(sbi->s_inode_size) ||
999 (sbi->s_inode_size > blocksize)) {
1000 ext2_msg(sb, KERN_ERR,
1001 "error: unsupported inode size: %d",
1007 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1008 le32_to_cpu(es->s_log_frag_size);
1009 if (sbi->s_frag_size == 0)
1011 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1013 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1014 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1015 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1017 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1018 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1020 sbi->s_itb_per_group = sbi->s_inodes_per_group /
1021 sbi->s_inodes_per_block;
1022 sbi->s_desc_per_block = sb->s_blocksize /
1023 sizeof (struct ext2_group_desc);
1025 sbi->s_mount_state = le16_to_cpu(es->s_state);
1026 sbi->s_addr_per_block_bits =
1027 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1028 sbi->s_desc_per_block_bits =
1029 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1031 if (sb->s_magic != EXT2_SUPER_MAGIC)
1034 if (sb->s_blocksize != bh->b_size) {
1036 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1040 if (sb->s_blocksize != sbi->s_frag_size) {
1041 ext2_msg(sb, KERN_ERR,
1042 "error: fragsize %lu != blocksize %lu"
1043 "(not supported yet)",
1044 sbi->s_frag_size, sb->s_blocksize);
1048 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1049 ext2_msg(sb, KERN_ERR,
1050 "error: #blocks per group too big: %lu",
1051 sbi->s_blocks_per_group);
1054 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1055 ext2_msg(sb, KERN_ERR,
1056 "error: #fragments per group too big: %lu",
1057 sbi->s_frags_per_group);
1060 if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
1061 sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1062 ext2_msg(sb, KERN_ERR,
1063 "error: invalid #inodes per group: %lu",
1064 sbi->s_inodes_per_group);
1068 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1070 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1071 le32_to_cpu(es->s_first_data_block) - 1)
1072 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1073 if ((u64)sbi->s_groups_count * sbi->s_inodes_per_group !=
1074 le32_to_cpu(es->s_inodes_count)) {
1075 ext2_msg(sb, KERN_ERR, "error: invalid #inodes: %u vs computed %llu",
1076 le32_to_cpu(es->s_inodes_count),
1077 (u64)sbi->s_groups_count * sbi->s_inodes_per_group);
1080 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1081 EXT2_DESC_PER_BLOCK(sb);
1082 sbi->s_group_desc = kmalloc_array(db_count,
1083 sizeof(struct buffer_head *),
1085 if (sbi->s_group_desc == NULL) {
1087 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1090 bgl_lock_init(sbi->s_blockgroup_lock);
1091 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1092 if (!sbi->s_debts) {
1094 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1095 goto failed_mount_group_desc;
1097 for (i = 0; i < db_count; i++) {
1098 block = descriptor_loc(sb, logic_sb_block, i);
1099 sbi->s_group_desc[i] = sb_bread(sb, block);
1100 if (!sbi->s_group_desc[i]) {
1101 for (j = 0; j < i; j++)
1102 brelse (sbi->s_group_desc[j]);
1103 ext2_msg(sb, KERN_ERR,
1104 "error: unable to read group descriptors");
1105 goto failed_mount_group_desc;
1108 if (!ext2_check_descriptors (sb)) {
1109 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1112 sbi->s_gdb_count = db_count;
1113 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1114 spin_lock_init(&sbi->s_next_gen_lock);
1116 /* per filesystem reservation list head & lock */
1117 spin_lock_init(&sbi->s_rsv_window_lock);
1118 sbi->s_rsv_window_root = RB_ROOT;
1120 * Add a single, static dummy reservation to the start of the
1121 * reservation window list --- it gives us a placeholder for
1122 * append-at-start-of-list which makes the allocation logic
1125 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1126 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1127 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1128 sbi->s_rsv_window_head.rsv_goal_size = 0;
1129 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1131 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1132 ext2_count_free_blocks(sb), GFP_KERNEL);
1134 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1135 ext2_count_free_inodes(sb), GFP_KERNEL);
1138 err = percpu_counter_init(&sbi->s_dirs_counter,
1139 ext2_count_dirs(sb), GFP_KERNEL);
1143 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1147 #ifdef CONFIG_EXT2_FS_XATTR
1148 sbi->s_ea_block_cache = ext2_xattr_create_cache();
1149 if (!sbi->s_ea_block_cache) {
1151 ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1156 * set up enough so that it can read an inode
1158 sb->s_op = &ext2_sops;
1159 sb->s_export_op = &ext2_export_ops;
1160 sb->s_xattr = ext2_xattr_handlers;
1163 sb->dq_op = &dquot_operations;
1164 sb->s_qcop = &ext2_quotactl_ops;
1165 sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1168 root = ext2_iget(sb, EXT2_ROOT_INO);
1170 ret = PTR_ERR(root);
1173 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1175 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1179 sb->s_root = d_make_root(root);
1181 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1185 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1186 ext2_msg(sb, KERN_WARNING,
1187 "warning: mounting ext3 filesystem as ext2");
1188 if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1189 sb->s_flags |= SB_RDONLY;
1190 ext2_write_super(sb);
1195 ext2_msg(sb, KERN_ERR,
1196 "error: can't find an ext2 filesystem on dev %s.",
1200 ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1201 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1202 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1203 percpu_counter_destroy(&sbi->s_dirs_counter);
1205 for (i = 0; i < db_count; i++)
1206 brelse(sbi->s_group_desc[i]);
1207 failed_mount_group_desc:
1208 kfree(sbi->s_group_desc);
1209 kfree(sbi->s_debts);
1213 fs_put_dax(sbi->s_daxdev);
1214 sb->s_fs_info = NULL;
1215 kfree(sbi->s_blockgroup_lock);
1220 static void ext2_clear_super_error(struct super_block *sb)
1222 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1224 if (buffer_write_io_error(sbh)) {
1226 * Oh, dear. A previous attempt to write the
1227 * superblock failed. This could happen because the
1228 * USB device was yanked out. Or it could happen to
1229 * be a transient write error and maybe the block will
1230 * be remapped. Nothing we can do but to retry the
1231 * write and hope for the best.
1233 ext2_msg(sb, KERN_ERR,
1234 "previous I/O error to superblock detected");
1235 clear_buffer_write_io_error(sbh);
1236 set_buffer_uptodate(sbh);
1240 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1243 ext2_clear_super_error(sb);
1244 spin_lock(&EXT2_SB(sb)->s_lock);
1245 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1246 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1247 es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1248 /* unlock before we do IO */
1249 spin_unlock(&EXT2_SB(sb)->s_lock);
1250 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1252 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1256 * In the second extended file system, it is not necessary to
1257 * write the super block since we use a mapping of the
1258 * disk super block in a buffer.
1260 * However, this function is still used to set the fs valid
1261 * flags to 0. We need to set this flag to 0 since the fs
1262 * may have been checked while mounted and e2fsck may have
1263 * set s_state to EXT2_VALID_FS after some corrections.
1265 static int ext2_sync_fs(struct super_block *sb, int wait)
1267 struct ext2_sb_info *sbi = EXT2_SB(sb);
1268 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1271 * Write quota structures to quota file, sync_blockdev() will write
1272 * them to disk later
1274 dquot_writeback_dquots(sb, -1);
1276 spin_lock(&sbi->s_lock);
1277 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1278 ext2_debug("setting valid to 0\n");
1279 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1281 spin_unlock(&sbi->s_lock);
1282 ext2_sync_super(sb, es, wait);
1286 static int ext2_freeze(struct super_block *sb)
1288 struct ext2_sb_info *sbi = EXT2_SB(sb);
1291 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1292 * because we have unattached inodes and thus filesystem is not fully
1295 if (atomic_long_read(&sb->s_remove_count)) {
1296 ext2_sync_fs(sb, 1);
1299 /* Set EXT2_FS_VALID flag */
1300 spin_lock(&sbi->s_lock);
1301 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1302 spin_unlock(&sbi->s_lock);
1303 ext2_sync_super(sb, sbi->s_es, 1);
1308 static int ext2_unfreeze(struct super_block *sb)
1310 /* Just write sb to clear EXT2_VALID_FS flag */
1311 ext2_write_super(sb);
1316 static void ext2_write_super(struct super_block *sb)
1319 ext2_sync_fs(sb, 1);
1322 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1324 struct ext2_sb_info * sbi = EXT2_SB(sb);
1325 struct ext2_super_block * es;
1326 struct ext2_mount_options new_opts;
1329 sync_filesystem(sb);
1331 spin_lock(&sbi->s_lock);
1332 new_opts.s_mount_opt = sbi->s_mount_opt;
1333 new_opts.s_resuid = sbi->s_resuid;
1334 new_opts.s_resgid = sbi->s_resgid;
1335 spin_unlock(&sbi->s_lock);
1337 if (!parse_options(data, sb, &new_opts))
1340 spin_lock(&sbi->s_lock);
1342 if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1343 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1344 "dax flag with busy inodes while remounting");
1345 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1347 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1349 if (*flags & SB_RDONLY) {
1350 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1351 !(sbi->s_mount_state & EXT2_VALID_FS))
1355 * OK, we are remounting a valid rw partition rdonly, so set
1356 * the rdonly flag and then mark the partition as valid again.
1358 es->s_state = cpu_to_le16(sbi->s_mount_state);
1359 es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1360 spin_unlock(&sbi->s_lock);
1362 err = dquot_suspend(sb, -1);
1366 ext2_sync_super(sb, es, 1);
1368 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1369 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1371 spin_unlock(&sbi->s_lock);
1372 ext2_msg(sb, KERN_WARNING,
1373 "warning: couldn't remount RDWR because of "
1374 "unsupported optional features (%x).",
1379 * Mounting a RDONLY partition read-write, so reread and
1380 * store the current valid flag. (It may have been changed
1381 * by e2fsck since we originally mounted the partition.)
1383 sbi->s_mount_state = le16_to_cpu(es->s_state);
1384 if (!ext2_setup_super (sb, es, 0))
1385 sb->s_flags &= ~SB_RDONLY;
1386 spin_unlock(&sbi->s_lock);
1388 ext2_write_super(sb);
1390 dquot_resume(sb, -1);
1393 spin_lock(&sbi->s_lock);
1395 sbi->s_mount_opt = new_opts.s_mount_opt;
1396 sbi->s_resuid = new_opts.s_resuid;
1397 sbi->s_resgid = new_opts.s_resgid;
1398 sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1399 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
1400 spin_unlock(&sbi->s_lock);
1405 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1407 struct super_block *sb = dentry->d_sb;
1408 struct ext2_sb_info *sbi = EXT2_SB(sb);
1409 struct ext2_super_block *es = sbi->s_es;
1411 spin_lock(&sbi->s_lock);
1413 if (test_opt (sb, MINIX_DF))
1414 sbi->s_overhead_last = 0;
1415 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1416 unsigned long i, overhead = 0;
1420 * Compute the overhead (FS structures). This is constant
1421 * for a given filesystem unless the number of block groups
1422 * changes so we cache the previous value until it does.
1426 * All of the blocks before first_data_block are
1429 overhead = le32_to_cpu(es->s_first_data_block);
1432 * Add the overhead attributed to the superblock and
1433 * block group descriptors. If the sparse superblocks
1434 * feature is turned on, then not all groups have this.
1436 for (i = 0; i < sbi->s_groups_count; i++)
1437 overhead += ext2_bg_has_super(sb, i) +
1438 ext2_bg_num_gdb(sb, i);
1441 * Every block group has an inode bitmap, a block
1442 * bitmap, and an inode table.
1444 overhead += (sbi->s_groups_count *
1445 (2 + sbi->s_itb_per_group));
1446 sbi->s_overhead_last = overhead;
1448 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1451 buf->f_type = EXT2_SUPER_MAGIC;
1452 buf->f_bsize = sb->s_blocksize;
1453 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1454 buf->f_bfree = ext2_count_free_blocks(sb);
1455 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1456 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1457 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1459 buf->f_files = le32_to_cpu(es->s_inodes_count);
1460 buf->f_ffree = ext2_count_free_inodes(sb);
1461 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1462 buf->f_namelen = EXT2_NAME_LEN;
1463 buf->f_fsid = uuid_to_fsid(es->s_uuid);
1464 spin_unlock(&sbi->s_lock);
1468 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1469 int flags, const char *dev_name, void *data)
1471 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1476 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1477 * acquiring the locks... As quota files are never truncated and quota code
1478 * itself serializes the operations (and no one else should touch the files)
1479 * we don't have to be afraid of races */
1480 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1481 size_t len, loff_t off)
1483 struct inode *inode = sb_dqopt(sb)->files[type];
1484 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1486 int offset = off & (sb->s_blocksize - 1);
1489 struct buffer_head tmp_bh;
1490 struct buffer_head *bh;
1491 loff_t i_size = i_size_read(inode);
1495 if (off+len > i_size)
1498 while (toread > 0) {
1499 tocopy = min_t(size_t, sb->s_blocksize - offset, toread);
1502 tmp_bh.b_size = sb->s_blocksize;
1503 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1506 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1507 memset(data, 0, tocopy);
1509 bh = sb_bread(sb, tmp_bh.b_blocknr);
1512 memcpy(data, bh->b_data+offset, tocopy);
1523 /* Write to quotafile */
1524 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1525 const char *data, size_t len, loff_t off)
1527 struct inode *inode = sb_dqopt(sb)->files[type];
1528 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1530 int offset = off & (sb->s_blocksize - 1);
1532 size_t towrite = len;
1533 struct buffer_head tmp_bh;
1534 struct buffer_head *bh;
1536 while (towrite > 0) {
1537 tocopy = min_t(size_t, sb->s_blocksize - offset, towrite);
1540 tmp_bh.b_size = sb->s_blocksize;
1541 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1544 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1545 bh = sb_bread(sb, tmp_bh.b_blocknr);
1547 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1548 if (unlikely(!bh)) {
1553 memcpy(bh->b_data+offset, data, tocopy);
1554 flush_dcache_page(bh->b_page);
1555 set_buffer_uptodate(bh);
1556 mark_buffer_dirty(bh);
1567 if (inode->i_size < off+len-towrite)
1568 i_size_write(inode, off+len-towrite);
1569 inode_inc_iversion(inode);
1570 inode->i_mtime = inode->i_ctime = current_time(inode);
1571 mark_inode_dirty(inode);
1572 return len - towrite;
1575 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1576 const struct path *path)
1579 struct inode *inode;
1581 err = dquot_quota_on(sb, type, format_id, path);
1585 inode = d_inode(path->dentry);
1587 EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1588 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1589 S_NOATIME | S_IMMUTABLE);
1590 inode_unlock(inode);
1591 mark_inode_dirty(inode);
1596 static int ext2_quota_off(struct super_block *sb, int type)
1598 struct inode *inode = sb_dqopt(sb)->files[type];
1601 if (!inode || !igrab(inode))
1604 err = dquot_quota_off(sb, type);
1609 EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1610 inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1611 inode_unlock(inode);
1612 mark_inode_dirty(inode);
1617 return dquot_quota_off(sb, type);
1622 static struct file_system_type ext2_fs_type = {
1623 .owner = THIS_MODULE,
1625 .mount = ext2_mount,
1626 .kill_sb = kill_block_super,
1627 .fs_flags = FS_REQUIRES_DEV,
1629 MODULE_ALIAS_FS("ext2");
1631 static int __init init_ext2_fs(void)
1635 err = init_inodecache();
1638 err = register_filesystem(&ext2_fs_type);
1643 destroy_inodecache();
1647 static void __exit exit_ext2_fs(void)
1649 unregister_filesystem(&ext2_fs_type);
1650 destroy_inodecache();
1653 MODULE_AUTHOR("Remy Card and others");
1654 MODULE_DESCRIPTION("Second Extended Filesystem");
1655 MODULE_LICENSE("GPL");
1656 module_init(init_ext2_fs)
1657 module_exit(exit_ext2_fs)