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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/ext2/super.c
4 *
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)
9 *
10 * from
11 *
12 * linux/fs/minix/inode.c
13 *
14 * Copyright (C) 1991, 1992 Linus Torvalds
15 *
16 * Big-endian to little-endian byte-swapping/bitmaps by
17 * David S. Miller (davem@caip.rutgers.edu), 1995
18 */
19
20#include <linux/module.h>
21#include <linux/string.h>
22#include <linux/fs.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>
38#include "ext2.h"
39#include "xattr.h"
40#include "acl.h"
41
42static void ext2_write_super(struct super_block *sb);
43static int ext2_remount (struct super_block * sb, int * flags, char * data);
44static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
45static int ext2_sync_fs(struct super_block *sb, int wait);
46static int ext2_freeze(struct super_block *sb);
47static int ext2_unfreeze(struct super_block *sb);
48
49void ext2_error(struct super_block *sb, const char *function,
50 const char *fmt, ...)
51{
52 struct va_format vaf;
53 va_list args;
54 struct ext2_sb_info *sbi = EXT2_SB(sb);
55 struct ext2_super_block *es = sbi->s_es;
56
57 if (!sb_rdonly(sb)) {
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);
63 }
64
65 va_start(args, fmt);
66
67 vaf.fmt = fmt;
68 vaf.va = &args;
69
70 printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
71 sb->s_id, function, &vaf);
72
73 va_end(args);
74
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;
81 }
82}
83
84void ext2_msg(struct super_block *sb, const char *prefix,
85 const char *fmt, ...)
86{
87 struct va_format vaf;
88 va_list args;
89
90 va_start(args, fmt);
91
92 vaf.fmt = fmt;
93 vaf.va = &args;
94
95 printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
96
97 va_end(args);
98}
99
100/*
101 * This must be called with sbi->s_lock held.
102 */
103void ext2_update_dynamic_rev(struct super_block *sb)
104{
105 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
106
107 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
108 return;
109
110 ext2_msg(sb, KERN_WARNING,
111 "warning: updating to rev %d because of "
112 "new feature flag, running e2fsck is recommended",
113 EXT2_DYNAMIC_REV);
114
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 */
120
121 /*
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.
125 */
126}
127
128#ifdef CONFIG_QUOTA
129static int ext2_quota_off(struct super_block *sb, int type);
130
131static void ext2_quota_off_umount(struct super_block *sb)
132{
133 int type;
134
135 for (type = 0; type < MAXQUOTAS; type++)
136 ext2_quota_off(sb, type);
137}
138#else
139static inline void ext2_quota_off_umount(struct super_block *sb)
140{
141}
142#endif
143
144static void ext2_put_super (struct super_block * sb)
145{
146 int db_count;
147 int i;
148 struct ext2_sb_info *sbi = EXT2_SB(sb);
149
150 ext2_quota_off_umount(sb);
151
152 ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
153 sbi->s_ea_block_cache = NULL;
154
155 if (!sb_rdonly(sb)) {
156 struct ext2_super_block *es = sbi->s_es;
157
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);
162 }
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);
167 kfree(sbi->s_debts);
168 percpu_counter_destroy(&sbi->s_freeblocks_counter);
169 percpu_counter_destroy(&sbi->s_freeinodes_counter);
170 percpu_counter_destroy(&sbi->s_dirs_counter);
171 brelse (sbi->s_sbh);
172 sb->s_fs_info = NULL;
173 kfree(sbi->s_blockgroup_lock);
174 fs_put_dax(sbi->s_daxdev);
175 kfree(sbi);
176}
177
178static struct kmem_cache * ext2_inode_cachep;
179
180static struct inode *ext2_alloc_inode(struct super_block *sb)
181{
182 struct ext2_inode_info *ei;
183 ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
184 if (!ei)
185 return NULL;
186 ei->i_block_alloc_info = NULL;
187 inode_set_iversion(&ei->vfs_inode, 1);
188#ifdef CONFIG_QUOTA
189 memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
190#endif
191
192 return &ei->vfs_inode;
193}
194
195static void ext2_free_in_core_inode(struct inode *inode)
196{
197 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
198}
199
200static void init_once(void *foo)
201{
202 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
203
204 rwlock_init(&ei->i_meta_lock);
205#ifdef CONFIG_EXT2_FS_XATTR
206 init_rwsem(&ei->xattr_sem);
207#endif
208 mutex_init(&ei->truncate_mutex);
209#ifdef CONFIG_FS_DAX
210 init_rwsem(&ei->dax_sem);
211#endif
212 inode_init_once(&ei->vfs_inode);
213}
214
215static int __init init_inodecache(void)
216{
217 ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
218 sizeof(struct ext2_inode_info), 0,
219 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
220 SLAB_ACCOUNT),
221 offsetof(struct ext2_inode_info, i_data),
222 sizeof_field(struct ext2_inode_info, i_data),
223 init_once);
224 if (ext2_inode_cachep == NULL)
225 return -ENOMEM;
226 return 0;
227}
228
229static void destroy_inodecache(void)
230{
231 /*
232 * Make sure all delayed rcu free inodes are flushed before we
233 * destroy cache.
234 */
235 rcu_barrier();
236 kmem_cache_destroy(ext2_inode_cachep);
237}
238
239static int ext2_show_options(struct seq_file *seq, struct dentry *root)
240{
241 struct super_block *sb = root->d_sb;
242 struct ext2_sb_info *sbi = EXT2_SB(sb);
243 struct ext2_super_block *es = sbi->s_es;
244 unsigned long def_mount_opts;
245
246 spin_lock(&sbi->s_lock);
247 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
248
249 if (sbi->s_sb_block != 1)
250 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
251 if (test_opt(sb, MINIX_DF))
252 seq_puts(seq, ",minixdf");
253 if (test_opt(sb, GRPID))
254 seq_puts(seq, ",grpid");
255 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
256 seq_puts(seq, ",nogrpid");
257 if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
258 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
259 seq_printf(seq, ",resuid=%u",
260 from_kuid_munged(&init_user_ns, sbi->s_resuid));
261 }
262 if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
263 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
264 seq_printf(seq, ",resgid=%u",
265 from_kgid_munged(&init_user_ns, sbi->s_resgid));
266 }
267 if (test_opt(sb, ERRORS_RO)) {
268 int def_errors = le16_to_cpu(es->s_errors);
269
270 if (def_errors == EXT2_ERRORS_PANIC ||
271 def_errors == EXT2_ERRORS_CONTINUE) {
272 seq_puts(seq, ",errors=remount-ro");
273 }
274 }
275 if (test_opt(sb, ERRORS_CONT))
276 seq_puts(seq, ",errors=continue");
277 if (test_opt(sb, ERRORS_PANIC))
278 seq_puts(seq, ",errors=panic");
279 if (test_opt(sb, NO_UID32))
280 seq_puts(seq, ",nouid32");
281 if (test_opt(sb, DEBUG))
282 seq_puts(seq, ",debug");
283 if (test_opt(sb, OLDALLOC))
284 seq_puts(seq, ",oldalloc");
285
286#ifdef CONFIG_EXT2_FS_XATTR
287 if (test_opt(sb, XATTR_USER))
288 seq_puts(seq, ",user_xattr");
289 if (!test_opt(sb, XATTR_USER) &&
290 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
291 seq_puts(seq, ",nouser_xattr");
292 }
293#endif
294
295#ifdef CONFIG_EXT2_FS_POSIX_ACL
296 if (test_opt(sb, POSIX_ACL))
297 seq_puts(seq, ",acl");
298 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
299 seq_puts(seq, ",noacl");
300#endif
301
302 if (test_opt(sb, NOBH))
303 seq_puts(seq, ",nobh");
304
305 if (test_opt(sb, USRQUOTA))
306 seq_puts(seq, ",usrquota");
307
308 if (test_opt(sb, GRPQUOTA))
309 seq_puts(seq, ",grpquota");
310
311 if (test_opt(sb, XIP))
312 seq_puts(seq, ",xip");
313
314 if (test_opt(sb, DAX))
315 seq_puts(seq, ",dax");
316
317 if (!test_opt(sb, RESERVATION))
318 seq_puts(seq, ",noreservation");
319
320 spin_unlock(&sbi->s_lock);
321 return 0;
322}
323
324#ifdef CONFIG_QUOTA
325static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
326static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
327static int ext2_quota_on(struct super_block *sb, int type, int format_id,
328 const struct path *path);
329static struct dquot **ext2_get_dquots(struct inode *inode)
330{
331 return EXT2_I(inode)->i_dquot;
332}
333
334static const struct quotactl_ops ext2_quotactl_ops = {
335 .quota_on = ext2_quota_on,
336 .quota_off = ext2_quota_off,
337 .quota_sync = dquot_quota_sync,
338 .get_state = dquot_get_state,
339 .set_info = dquot_set_dqinfo,
340 .get_dqblk = dquot_get_dqblk,
341 .set_dqblk = dquot_set_dqblk,
342 .get_nextdqblk = dquot_get_next_dqblk,
343};
344#endif
345
346static const struct super_operations ext2_sops = {
347 .alloc_inode = ext2_alloc_inode,
348 .free_inode = ext2_free_in_core_inode,
349 .write_inode = ext2_write_inode,
350 .evict_inode = ext2_evict_inode,
351 .put_super = ext2_put_super,
352 .sync_fs = ext2_sync_fs,
353 .freeze_fs = ext2_freeze,
354 .unfreeze_fs = ext2_unfreeze,
355 .statfs = ext2_statfs,
356 .remount_fs = ext2_remount,
357 .show_options = ext2_show_options,
358#ifdef CONFIG_QUOTA
359 .quota_read = ext2_quota_read,
360 .quota_write = ext2_quota_write,
361 .get_dquots = ext2_get_dquots,
362#endif
363};
364
365static struct inode *ext2_nfs_get_inode(struct super_block *sb,
366 u64 ino, u32 generation)
367{
368 struct inode *inode;
369
370 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
371 return ERR_PTR(-ESTALE);
372 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
373 return ERR_PTR(-ESTALE);
374
375 /*
376 * ext2_iget isn't quite right if the inode is currently unallocated!
377 * However ext2_iget currently does appropriate checks to handle stale
378 * inodes so everything is OK.
379 */
380 inode = ext2_iget(sb, ino);
381 if (IS_ERR(inode))
382 return ERR_CAST(inode);
383 if (generation && inode->i_generation != generation) {
384 /* we didn't find the right inode.. */
385 iput(inode);
386 return ERR_PTR(-ESTALE);
387 }
388 return inode;
389}
390
391static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
392 int fh_len, int fh_type)
393{
394 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
395 ext2_nfs_get_inode);
396}
397
398static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
399 int fh_len, int fh_type)
400{
401 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
402 ext2_nfs_get_inode);
403}
404
405static const struct export_operations ext2_export_ops = {
406 .fh_to_dentry = ext2_fh_to_dentry,
407 .fh_to_parent = ext2_fh_to_parent,
408 .get_parent = ext2_get_parent,
409};
410
411static unsigned long get_sb_block(void **data)
412{
413 unsigned long sb_block;
414 char *options = (char *) *data;
415
416 if (!options || strncmp(options, "sb=", 3) != 0)
417 return 1; /* Default location */
418 options += 3;
419 sb_block = simple_strtoul(options, &options, 0);
420 if (*options && *options != ',') {
421 printk("EXT2-fs: Invalid sb specification: %s\n",
422 (char *) *data);
423 return 1;
424 }
425 if (*options == ',')
426 options++;
427 *data = (void *) options;
428 return sb_block;
429}
430
431enum {
432 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
433 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
434 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
435 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
436 Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
437 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
438};
439
440static const match_table_t tokens = {
441 {Opt_bsd_df, "bsddf"},
442 {Opt_minix_df, "minixdf"},
443 {Opt_grpid, "grpid"},
444 {Opt_grpid, "bsdgroups"},
445 {Opt_nogrpid, "nogrpid"},
446 {Opt_nogrpid, "sysvgroups"},
447 {Opt_resgid, "resgid=%u"},
448 {Opt_resuid, "resuid=%u"},
449 {Opt_sb, "sb=%u"},
450 {Opt_err_cont, "errors=continue"},
451 {Opt_err_panic, "errors=panic"},
452 {Opt_err_ro, "errors=remount-ro"},
453 {Opt_nouid32, "nouid32"},
454 {Opt_nocheck, "check=none"},
455 {Opt_nocheck, "nocheck"},
456 {Opt_debug, "debug"},
457 {Opt_oldalloc, "oldalloc"},
458 {Opt_orlov, "orlov"},
459 {Opt_nobh, "nobh"},
460 {Opt_user_xattr, "user_xattr"},
461 {Opt_nouser_xattr, "nouser_xattr"},
462 {Opt_acl, "acl"},
463 {Opt_noacl, "noacl"},
464 {Opt_xip, "xip"},
465 {Opt_dax, "dax"},
466 {Opt_grpquota, "grpquota"},
467 {Opt_ignore, "noquota"},
468 {Opt_quota, "quota"},
469 {Opt_usrquota, "usrquota"},
470 {Opt_reservation, "reservation"},
471 {Opt_noreservation, "noreservation"},
472 {Opt_err, NULL}
473};
474
475static int parse_options(char *options, struct super_block *sb,
476 struct ext2_mount_options *opts)
477{
478 char *p;
479 substring_t args[MAX_OPT_ARGS];
480 int option;
481 kuid_t uid;
482 kgid_t gid;
483
484 if (!options)
485 return 1;
486
487 while ((p = strsep (&options, ",")) != NULL) {
488 int token;
489 if (!*p)
490 continue;
491
492 token = match_token(p, tokens, args);
493 switch (token) {
494 case Opt_bsd_df:
495 clear_opt (opts->s_mount_opt, MINIX_DF);
496 break;
497 case Opt_minix_df:
498 set_opt (opts->s_mount_opt, MINIX_DF);
499 break;
500 case Opt_grpid:
501 set_opt (opts->s_mount_opt, GRPID);
502 break;
503 case Opt_nogrpid:
504 clear_opt (opts->s_mount_opt, GRPID);
505 break;
506 case Opt_resuid:
507 if (match_int(&args[0], &option))
508 return 0;
509 uid = make_kuid(current_user_ns(), option);
510 if (!uid_valid(uid)) {
511 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
512 return 0;
513
514 }
515 opts->s_resuid = uid;
516 break;
517 case Opt_resgid:
518 if (match_int(&args[0], &option))
519 return 0;
520 gid = make_kgid(current_user_ns(), option);
521 if (!gid_valid(gid)) {
522 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
523 return 0;
524 }
525 opts->s_resgid = gid;
526 break;
527 case Opt_sb:
528 /* handled by get_sb_block() instead of here */
529 /* *sb_block = match_int(&args[0]); */
530 break;
531 case Opt_err_panic:
532 clear_opt (opts->s_mount_opt, ERRORS_CONT);
533 clear_opt (opts->s_mount_opt, ERRORS_RO);
534 set_opt (opts->s_mount_opt, ERRORS_PANIC);
535 break;
536 case Opt_err_ro:
537 clear_opt (opts->s_mount_opt, ERRORS_CONT);
538 clear_opt (opts->s_mount_opt, ERRORS_PANIC);
539 set_opt (opts->s_mount_opt, ERRORS_RO);
540 break;
541 case Opt_err_cont:
542 clear_opt (opts->s_mount_opt, ERRORS_RO);
543 clear_opt (opts->s_mount_opt, ERRORS_PANIC);
544 set_opt (opts->s_mount_opt, ERRORS_CONT);
545 break;
546 case Opt_nouid32:
547 set_opt (opts->s_mount_opt, NO_UID32);
548 break;
549 case Opt_nocheck:
550 ext2_msg(sb, KERN_WARNING,
551 "Option nocheck/check=none is deprecated and"
552 " will be removed in June 2020.");
553 clear_opt (opts->s_mount_opt, CHECK);
554 break;
555 case Opt_debug:
556 set_opt (opts->s_mount_opt, DEBUG);
557 break;
558 case Opt_oldalloc:
559 set_opt (opts->s_mount_opt, OLDALLOC);
560 break;
561 case Opt_orlov:
562 clear_opt (opts->s_mount_opt, OLDALLOC);
563 break;
564 case Opt_nobh:
565 set_opt (opts->s_mount_opt, NOBH);
566 break;
567#ifdef CONFIG_EXT2_FS_XATTR
568 case Opt_user_xattr:
569 set_opt (opts->s_mount_opt, XATTR_USER);
570 break;
571 case Opt_nouser_xattr:
572 clear_opt (opts->s_mount_opt, XATTR_USER);
573 break;
574#else
575 case Opt_user_xattr:
576 case Opt_nouser_xattr:
577 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
578 "not supported");
579 break;
580#endif
581#ifdef CONFIG_EXT2_FS_POSIX_ACL
582 case Opt_acl:
583 set_opt(opts->s_mount_opt, POSIX_ACL);
584 break;
585 case Opt_noacl:
586 clear_opt(opts->s_mount_opt, POSIX_ACL);
587 break;
588#else
589 case Opt_acl:
590 case Opt_noacl:
591 ext2_msg(sb, KERN_INFO,
592 "(no)acl options not supported");
593 break;
594#endif
595 case Opt_xip:
596 ext2_msg(sb, KERN_INFO, "use dax instead of xip");
597 set_opt(opts->s_mount_opt, XIP);
598 /* Fall through */
599 case Opt_dax:
600#ifdef CONFIG_FS_DAX
601 ext2_msg(sb, KERN_WARNING,
602 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
603 set_opt(opts->s_mount_opt, DAX);
604#else
605 ext2_msg(sb, KERN_INFO, "dax option not supported");
606#endif
607 break;
608
609#if defined(CONFIG_QUOTA)
610 case Opt_quota:
611 case Opt_usrquota:
612 set_opt(opts->s_mount_opt, USRQUOTA);
613 break;
614
615 case Opt_grpquota:
616 set_opt(opts->s_mount_opt, GRPQUOTA);
617 break;
618#else
619 case Opt_quota:
620 case Opt_usrquota:
621 case Opt_grpquota:
622 ext2_msg(sb, KERN_INFO,
623 "quota operations not supported");
624 break;
625#endif
626
627 case Opt_reservation:
628 set_opt(opts->s_mount_opt, RESERVATION);
629 ext2_msg(sb, KERN_INFO, "reservations ON");
630 break;
631 case Opt_noreservation:
632 clear_opt(opts->s_mount_opt, RESERVATION);
633 ext2_msg(sb, KERN_INFO, "reservations OFF");
634 break;
635 case Opt_ignore:
636 break;
637 default:
638 return 0;
639 }
640 }
641 return 1;
642}
643
644static int ext2_setup_super (struct super_block * sb,
645 struct ext2_super_block * es,
646 int read_only)
647{
648 int res = 0;
649 struct ext2_sb_info *sbi = EXT2_SB(sb);
650
651 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
652 ext2_msg(sb, KERN_ERR,
653 "error: revision level too high, "
654 "forcing read-only mode");
655 res = SB_RDONLY;
656 }
657 if (read_only)
658 return res;
659 if (!(sbi->s_mount_state & EXT2_VALID_FS))
660 ext2_msg(sb, KERN_WARNING,
661 "warning: mounting unchecked fs, "
662 "running e2fsck is recommended");
663 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
664 ext2_msg(sb, KERN_WARNING,
665 "warning: mounting fs with errors, "
666 "running e2fsck is recommended");
667 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
668 le16_to_cpu(es->s_mnt_count) >=
669 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
670 ext2_msg(sb, KERN_WARNING,
671 "warning: maximal mount count reached, "
672 "running e2fsck is recommended");
673 else if (le32_to_cpu(es->s_checkinterval) &&
674 (le32_to_cpu(es->s_lastcheck) +
675 le32_to_cpu(es->s_checkinterval) <=
676 ktime_get_real_seconds()))
677 ext2_msg(sb, KERN_WARNING,
678 "warning: checktime reached, "
679 "running e2fsck is recommended");
680 if (!le16_to_cpu(es->s_max_mnt_count))
681 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
682 le16_add_cpu(&es->s_mnt_count, 1);
683 if (test_opt (sb, DEBUG))
684 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
685 "bpg=%lu, ipg=%lu, mo=%04lx]",
686 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
687 sbi->s_frag_size,
688 sbi->s_groups_count,
689 EXT2_BLOCKS_PER_GROUP(sb),
690 EXT2_INODES_PER_GROUP(sb),
691 sbi->s_mount_opt);
692 return res;
693}
694
695static int ext2_check_descriptors(struct super_block *sb)
696{
697 int i;
698 struct ext2_sb_info *sbi = EXT2_SB(sb);
699
700 ext2_debug ("Checking group descriptors");
701
702 for (i = 0; i < sbi->s_groups_count; i++) {
703 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
704 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
705 ext2_fsblk_t last_block;
706
707 if (i == sbi->s_groups_count - 1)
708 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
709 else
710 last_block = first_block +
711 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
712
713 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
714 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
715 {
716 ext2_error (sb, "ext2_check_descriptors",
717 "Block bitmap for group %d"
718 " not in group (block %lu)!",
719 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
720 return 0;
721 }
722 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
723 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
724 {
725 ext2_error (sb, "ext2_check_descriptors",
726 "Inode bitmap for group %d"
727 " not in group (block %lu)!",
728 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
729 return 0;
730 }
731 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
732 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
733 last_block)
734 {
735 ext2_error (sb, "ext2_check_descriptors",
736 "Inode table for group %d"
737 " not in group (block %lu)!",
738 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
739 return 0;
740 }
741 }
742 return 1;
743}
744
745/*
746 * Maximal file size. There is a direct, and {,double-,triple-}indirect
747 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
748 * We need to be 1 filesystem block less than the 2^32 sector limit.
749 */
750static loff_t ext2_max_size(int bits)
751{
752 loff_t res = EXT2_NDIR_BLOCKS;
753 int meta_blocks;
754 unsigned int upper_limit;
755 unsigned int ppb = 1 << (bits-2);
756
757 /* This is calculated to be the largest file size for a
758 * dense, file such that the total number of
759 * sectors in the file, including data and all indirect blocks,
760 * does not exceed 2^32 -1
761 * __u32 i_blocks representing the total number of
762 * 512 bytes blocks of the file
763 */
764 upper_limit = (1LL << 32) - 1;
765
766 /* total blocks in file system block size */
767 upper_limit >>= (bits - 9);
768
769 /* Compute how many blocks we can address by block tree */
770 res += 1LL << (bits-2);
771 res += 1LL << (2*(bits-2));
772 res += 1LL << (3*(bits-2));
773 /* Does block tree limit file size? */
774 if (res < upper_limit)
775 goto check_lfs;
776
777 res = upper_limit;
778 /* How many metadata blocks are needed for addressing upper_limit? */
779 upper_limit -= EXT2_NDIR_BLOCKS;
780 /* indirect blocks */
781 meta_blocks = 1;
782 upper_limit -= ppb;
783 /* double indirect blocks */
784 if (upper_limit < ppb * ppb) {
785 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
786 res -= meta_blocks;
787 goto check_lfs;
788 }
789 meta_blocks += 1 + ppb;
790 upper_limit -= ppb * ppb;
791 /* tripple indirect blocks for the rest */
792 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
793 DIV_ROUND_UP(upper_limit, ppb*ppb);
794 res -= meta_blocks;
795check_lfs:
796 res <<= bits;
797 if (res > MAX_LFS_FILESIZE)
798 res = MAX_LFS_FILESIZE;
799
800 return res;
801}
802
803static unsigned long descriptor_loc(struct super_block *sb,
804 unsigned long logic_sb_block,
805 int nr)
806{
807 struct ext2_sb_info *sbi = EXT2_SB(sb);
808 unsigned long bg, first_meta_bg;
809 int has_super = 0;
810
811 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
812
813 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
814 nr < first_meta_bg)
815 return (logic_sb_block + nr + 1);
816 bg = sbi->s_desc_per_block * nr;
817 if (ext2_bg_has_super(sb, bg))
818 has_super = 1;
819
820 return ext2_group_first_block_no(sb, bg) + has_super;
821}
822
823static int ext2_fill_super(struct super_block *sb, void *data, int silent)
824{
825 struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
826 struct buffer_head * bh;
827 struct ext2_sb_info * sbi;
828 struct ext2_super_block * es;
829 struct inode *root;
830 unsigned long block;
831 unsigned long sb_block = get_sb_block(&data);
832 unsigned long logic_sb_block;
833 unsigned long offset = 0;
834 unsigned long def_mount_opts;
835 long ret = -ENOMEM;
836 int blocksize = BLOCK_SIZE;
837 int db_count;
838 int i, j;
839 __le32 features;
840 int err;
841 struct ext2_mount_options opts;
842
843 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
844 if (!sbi)
845 goto failed;
846
847 sbi->s_blockgroup_lock =
848 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
849 if (!sbi->s_blockgroup_lock) {
850 kfree(sbi);
851 goto failed;
852 }
853 sb->s_fs_info = sbi;
854 sbi->s_sb_block = sb_block;
855 sbi->s_daxdev = dax_dev;
856
857 spin_lock_init(&sbi->s_lock);
858 ret = -EINVAL;
859
860 /*
861 * See what the current blocksize for the device is, and
862 * use that as the blocksize. Otherwise (or if the blocksize
863 * is smaller than the default) use the default.
864 * This is important for devices that have a hardware
865 * sectorsize that is larger than the default.
866 */
867 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
868 if (!blocksize) {
869 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
870 goto failed_sbi;
871 }
872
873 /*
874 * If the superblock doesn't start on a hardware sector boundary,
875 * calculate the offset.
876 */
877 if (blocksize != BLOCK_SIZE) {
878 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
879 offset = (sb_block*BLOCK_SIZE) % blocksize;
880 } else {
881 logic_sb_block = sb_block;
882 }
883
884 if (!(bh = sb_bread(sb, logic_sb_block))) {
885 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
886 goto failed_sbi;
887 }
888 /*
889 * Note: s_es must be initialized as soon as possible because
890 * some ext2 macro-instructions depend on its value
891 */
892 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
893 sbi->s_es = es;
894 sb->s_magic = le16_to_cpu(es->s_magic);
895
896 if (sb->s_magic != EXT2_SUPER_MAGIC)
897 goto cantfind_ext2;
898
899 opts.s_mount_opt = 0;
900 /* Set defaults before we parse the mount options */
901 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
902 if (def_mount_opts & EXT2_DEFM_DEBUG)
903 set_opt(opts.s_mount_opt, DEBUG);
904 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
905 set_opt(opts.s_mount_opt, GRPID);
906 if (def_mount_opts & EXT2_DEFM_UID16)
907 set_opt(opts.s_mount_opt, NO_UID32);
908#ifdef CONFIG_EXT2_FS_XATTR
909 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
910 set_opt(opts.s_mount_opt, XATTR_USER);
911#endif
912#ifdef CONFIG_EXT2_FS_POSIX_ACL
913 if (def_mount_opts & EXT2_DEFM_ACL)
914 set_opt(opts.s_mount_opt, POSIX_ACL);
915#endif
916
917 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
918 set_opt(opts.s_mount_opt, ERRORS_PANIC);
919 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
920 set_opt(opts.s_mount_opt, ERRORS_CONT);
921 else
922 set_opt(opts.s_mount_opt, ERRORS_RO);
923
924 opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
925 opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
926
927 set_opt(opts.s_mount_opt, RESERVATION);
928
929 if (!parse_options((char *) data, sb, &opts))
930 goto failed_mount;
931
932 sbi->s_mount_opt = opts.s_mount_opt;
933 sbi->s_resuid = opts.s_resuid;
934 sbi->s_resgid = opts.s_resgid;
935
936 sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
937 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
938 sb->s_iflags |= SB_I_CGROUPWB;
939
940 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
941 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
942 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
943 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
944 ext2_msg(sb, KERN_WARNING,
945 "warning: feature flags set on rev 0 fs, "
946 "running e2fsck is recommended");
947 /*
948 * Check feature flags regardless of the revision level, since we
949 * previously didn't change the revision level when setting the flags,
950 * so there is a chance incompat flags are set on a rev 0 filesystem.
951 */
952 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
953 if (features) {
954 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
955 "unsupported optional features (%x)",
956 le32_to_cpu(features));
957 goto failed_mount;
958 }
959 if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
960 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
961 "unsupported optional features (%x)",
962 le32_to_cpu(features));
963 goto failed_mount;
964 }
965
966 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
967
968 if (test_opt(sb, DAX)) {
969 if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
970 ext2_msg(sb, KERN_ERR,
971 "DAX unsupported by block device. Turning off DAX.");
972 clear_opt(sbi->s_mount_opt, DAX);
973 }
974 }
975
976 /* If the blocksize doesn't match, re-read the thing.. */
977 if (sb->s_blocksize != blocksize) {
978 brelse(bh);
979
980 if (!sb_set_blocksize(sb, blocksize)) {
981 ext2_msg(sb, KERN_ERR,
982 "error: bad blocksize %d", blocksize);
983 goto failed_sbi;
984 }
985
986 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
987 offset = (sb_block*BLOCK_SIZE) % blocksize;
988 bh = sb_bread(sb, logic_sb_block);
989 if(!bh) {
990 ext2_msg(sb, KERN_ERR, "error: couldn't read"
991 "superblock on 2nd try");
992 goto failed_sbi;
993 }
994 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
995 sbi->s_es = es;
996 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
997 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
998 goto failed_mount;
999 }
1000 }
1001
1002 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
1003 sb->s_max_links = EXT2_LINK_MAX;
1004 sb->s_time_min = S32_MIN;
1005 sb->s_time_max = S32_MAX;
1006
1007 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
1008 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
1009 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
1010 } else {
1011 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1012 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1013 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
1014 !is_power_of_2(sbi->s_inode_size) ||
1015 (sbi->s_inode_size > blocksize)) {
1016 ext2_msg(sb, KERN_ERR,
1017 "error: unsupported inode size: %d",
1018 sbi->s_inode_size);
1019 goto failed_mount;
1020 }
1021 }
1022
1023 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1024 le32_to_cpu(es->s_log_frag_size);
1025 if (sbi->s_frag_size == 0)
1026 goto cantfind_ext2;
1027 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1028
1029 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1030 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1031 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1032
1033 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1034 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1035 goto cantfind_ext2;
1036 sbi->s_itb_per_group = sbi->s_inodes_per_group /
1037 sbi->s_inodes_per_block;
1038 sbi->s_desc_per_block = sb->s_blocksize /
1039 sizeof (struct ext2_group_desc);
1040 sbi->s_sbh = bh;
1041 sbi->s_mount_state = le16_to_cpu(es->s_state);
1042 sbi->s_addr_per_block_bits =
1043 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1044 sbi->s_desc_per_block_bits =
1045 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1046
1047 if (sb->s_magic != EXT2_SUPER_MAGIC)
1048 goto cantfind_ext2;
1049
1050 if (sb->s_blocksize != bh->b_size) {
1051 if (!silent)
1052 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1053 goto failed_mount;
1054 }
1055
1056 if (sb->s_blocksize != sbi->s_frag_size) {
1057 ext2_msg(sb, KERN_ERR,
1058 "error: fragsize %lu != blocksize %lu"
1059 "(not supported yet)",
1060 sbi->s_frag_size, sb->s_blocksize);
1061 goto failed_mount;
1062 }
1063
1064 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1065 ext2_msg(sb, KERN_ERR,
1066 "error: #blocks per group too big: %lu",
1067 sbi->s_blocks_per_group);
1068 goto failed_mount;
1069 }
1070 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1071 ext2_msg(sb, KERN_ERR,
1072 "error: #fragments per group too big: %lu",
1073 sbi->s_frags_per_group);
1074 goto failed_mount;
1075 }
1076 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1077 ext2_msg(sb, KERN_ERR,
1078 "error: #inodes per group too big: %lu",
1079 sbi->s_inodes_per_group);
1080 goto failed_mount;
1081 }
1082
1083 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1084 goto cantfind_ext2;
1085 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1086 le32_to_cpu(es->s_first_data_block) - 1)
1087 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1088 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1089 EXT2_DESC_PER_BLOCK(sb);
1090 sbi->s_group_desc = kmalloc_array (db_count,
1091 sizeof(struct buffer_head *),
1092 GFP_KERNEL);
1093 if (sbi->s_group_desc == NULL) {
1094 ret = -ENOMEM;
1095 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1096 goto failed_mount;
1097 }
1098 bgl_lock_init(sbi->s_blockgroup_lock);
1099 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1100 if (!sbi->s_debts) {
1101 ret = -ENOMEM;
1102 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1103 goto failed_mount_group_desc;
1104 }
1105 for (i = 0; i < db_count; i++) {
1106 block = descriptor_loc(sb, logic_sb_block, i);
1107 sbi->s_group_desc[i] = sb_bread(sb, block);
1108 if (!sbi->s_group_desc[i]) {
1109 for (j = 0; j < i; j++)
1110 brelse (sbi->s_group_desc[j]);
1111 ext2_msg(sb, KERN_ERR,
1112 "error: unable to read group descriptors");
1113 goto failed_mount_group_desc;
1114 }
1115 }
1116 if (!ext2_check_descriptors (sb)) {
1117 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1118 goto failed_mount2;
1119 }
1120 sbi->s_gdb_count = db_count;
1121 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1122 spin_lock_init(&sbi->s_next_gen_lock);
1123
1124 /* per fileystem reservation list head & lock */
1125 spin_lock_init(&sbi->s_rsv_window_lock);
1126 sbi->s_rsv_window_root = RB_ROOT;
1127 /*
1128 * Add a single, static dummy reservation to the start of the
1129 * reservation window list --- it gives us a placeholder for
1130 * append-at-start-of-list which makes the allocation logic
1131 * _much_ simpler.
1132 */
1133 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1134 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1135 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1136 sbi->s_rsv_window_head.rsv_goal_size = 0;
1137 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1138
1139 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1140 ext2_count_free_blocks(sb), GFP_KERNEL);
1141 if (!err) {
1142 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1143 ext2_count_free_inodes(sb), GFP_KERNEL);
1144 }
1145 if (!err) {
1146 err = percpu_counter_init(&sbi->s_dirs_counter,
1147 ext2_count_dirs(sb), GFP_KERNEL);
1148 }
1149 if (err) {
1150 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1151 goto failed_mount3;
1152 }
1153
1154#ifdef CONFIG_EXT2_FS_XATTR
1155 sbi->s_ea_block_cache = ext2_xattr_create_cache();
1156 if (!sbi->s_ea_block_cache) {
1157 ret = -ENOMEM;
1158 ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1159 goto failed_mount3;
1160 }
1161#endif
1162 /*
1163 * set up enough so that it can read an inode
1164 */
1165 sb->s_op = &ext2_sops;
1166 sb->s_export_op = &ext2_export_ops;
1167 sb->s_xattr = ext2_xattr_handlers;
1168
1169#ifdef CONFIG_QUOTA
1170 sb->dq_op = &dquot_operations;
1171 sb->s_qcop = &ext2_quotactl_ops;
1172 sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1173#endif
1174
1175 root = ext2_iget(sb, EXT2_ROOT_INO);
1176 if (IS_ERR(root)) {
1177 ret = PTR_ERR(root);
1178 goto failed_mount3;
1179 }
1180 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1181 iput(root);
1182 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1183 goto failed_mount3;
1184 }
1185
1186 sb->s_root = d_make_root(root);
1187 if (!sb->s_root) {
1188 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1189 ret = -ENOMEM;
1190 goto failed_mount3;
1191 }
1192 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1193 ext2_msg(sb, KERN_WARNING,
1194 "warning: mounting ext3 filesystem as ext2");
1195 if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1196 sb->s_flags |= SB_RDONLY;
1197 ext2_write_super(sb);
1198 return 0;
1199
1200cantfind_ext2:
1201 if (!silent)
1202 ext2_msg(sb, KERN_ERR,
1203 "error: can't find an ext2 filesystem on dev %s.",
1204 sb->s_id);
1205 goto failed_mount;
1206failed_mount3:
1207 ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1208 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1209 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1210 percpu_counter_destroy(&sbi->s_dirs_counter);
1211failed_mount2:
1212 for (i = 0; i < db_count; i++)
1213 brelse(sbi->s_group_desc[i]);
1214failed_mount_group_desc:
1215 kfree(sbi->s_group_desc);
1216 kfree(sbi->s_debts);
1217failed_mount:
1218 brelse(bh);
1219failed_sbi:
1220 sb->s_fs_info = NULL;
1221 kfree(sbi->s_blockgroup_lock);
1222 kfree(sbi);
1223failed:
1224 fs_put_dax(dax_dev);
1225 return ret;
1226}
1227
1228static void ext2_clear_super_error(struct super_block *sb)
1229{
1230 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1231
1232 if (buffer_write_io_error(sbh)) {
1233 /*
1234 * Oh, dear. A previous attempt to write the
1235 * superblock failed. This could happen because the
1236 * USB device was yanked out. Or it could happen to
1237 * be a transient write error and maybe the block will
1238 * be remapped. Nothing we can do but to retry the
1239 * write and hope for the best.
1240 */
1241 ext2_msg(sb, KERN_ERR,
1242 "previous I/O error to superblock detected");
1243 clear_buffer_write_io_error(sbh);
1244 set_buffer_uptodate(sbh);
1245 }
1246}
1247
1248void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1249 int wait)
1250{
1251 ext2_clear_super_error(sb);
1252 spin_lock(&EXT2_SB(sb)->s_lock);
1253 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1254 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1255 es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1256 /* unlock before we do IO */
1257 spin_unlock(&EXT2_SB(sb)->s_lock);
1258 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1259 if (wait)
1260 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1261}
1262
1263/*
1264 * In the second extended file system, it is not necessary to
1265 * write the super block since we use a mapping of the
1266 * disk super block in a buffer.
1267 *
1268 * However, this function is still used to set the fs valid
1269 * flags to 0. We need to set this flag to 0 since the fs
1270 * may have been checked while mounted and e2fsck may have
1271 * set s_state to EXT2_VALID_FS after some corrections.
1272 */
1273static int ext2_sync_fs(struct super_block *sb, int wait)
1274{
1275 struct ext2_sb_info *sbi = EXT2_SB(sb);
1276 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1277
1278 /*
1279 * Write quota structures to quota file, sync_blockdev() will write
1280 * them to disk later
1281 */
1282 dquot_writeback_dquots(sb, -1);
1283
1284 spin_lock(&sbi->s_lock);
1285 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1286 ext2_debug("setting valid to 0\n");
1287 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1288 }
1289 spin_unlock(&sbi->s_lock);
1290 ext2_sync_super(sb, es, wait);
1291 return 0;
1292}
1293
1294static int ext2_freeze(struct super_block *sb)
1295{
1296 struct ext2_sb_info *sbi = EXT2_SB(sb);
1297
1298 /*
1299 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1300 * because we have unattached inodes and thus filesystem is not fully
1301 * consistent.
1302 */
1303 if (atomic_long_read(&sb->s_remove_count)) {
1304 ext2_sync_fs(sb, 1);
1305 return 0;
1306 }
1307 /* Set EXT2_FS_VALID flag */
1308 spin_lock(&sbi->s_lock);
1309 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1310 spin_unlock(&sbi->s_lock);
1311 ext2_sync_super(sb, sbi->s_es, 1);
1312
1313 return 0;
1314}
1315
1316static int ext2_unfreeze(struct super_block *sb)
1317{
1318 /* Just write sb to clear EXT2_VALID_FS flag */
1319 ext2_write_super(sb);
1320
1321 return 0;
1322}
1323
1324static void ext2_write_super(struct super_block *sb)
1325{
1326 if (!sb_rdonly(sb))
1327 ext2_sync_fs(sb, 1);
1328}
1329
1330static int ext2_remount (struct super_block * sb, int * flags, char * data)
1331{
1332 struct ext2_sb_info * sbi = EXT2_SB(sb);
1333 struct ext2_super_block * es;
1334 struct ext2_mount_options new_opts;
1335 int err;
1336
1337 sync_filesystem(sb);
1338
1339 spin_lock(&sbi->s_lock);
1340 new_opts.s_mount_opt = sbi->s_mount_opt;
1341 new_opts.s_resuid = sbi->s_resuid;
1342 new_opts.s_resgid = sbi->s_resgid;
1343 spin_unlock(&sbi->s_lock);
1344
1345 if (!parse_options(data, sb, &new_opts))
1346 return -EINVAL;
1347
1348 spin_lock(&sbi->s_lock);
1349 es = sbi->s_es;
1350 if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1351 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1352 "dax flag with busy inodes while remounting");
1353 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1354 }
1355 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1356 goto out_set;
1357 if (*flags & SB_RDONLY) {
1358 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1359 !(sbi->s_mount_state & EXT2_VALID_FS))
1360 goto out_set;
1361
1362 /*
1363 * OK, we are remounting a valid rw partition rdonly, so set
1364 * the rdonly flag and then mark the partition as valid again.
1365 */
1366 es->s_state = cpu_to_le16(sbi->s_mount_state);
1367 es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1368 spin_unlock(&sbi->s_lock);
1369
1370 err = dquot_suspend(sb, -1);
1371 if (err < 0)
1372 return err;
1373
1374 ext2_sync_super(sb, es, 1);
1375 } else {
1376 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1377 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1378 if (ret) {
1379 spin_unlock(&sbi->s_lock);
1380 ext2_msg(sb, KERN_WARNING,
1381 "warning: couldn't remount RDWR because of "
1382 "unsupported optional features (%x).",
1383 le32_to_cpu(ret));
1384 return -EROFS;
1385 }
1386 /*
1387 * Mounting a RDONLY partition read-write, so reread and
1388 * store the current valid flag. (It may have been changed
1389 * by e2fsck since we originally mounted the partition.)
1390 */
1391 sbi->s_mount_state = le16_to_cpu(es->s_state);
1392 if (!ext2_setup_super (sb, es, 0))
1393 sb->s_flags &= ~SB_RDONLY;
1394 spin_unlock(&sbi->s_lock);
1395
1396 ext2_write_super(sb);
1397
1398 dquot_resume(sb, -1);
1399 }
1400
1401 spin_lock(&sbi->s_lock);
1402out_set:
1403 sbi->s_mount_opt = new_opts.s_mount_opt;
1404 sbi->s_resuid = new_opts.s_resuid;
1405 sbi->s_resgid = new_opts.s_resgid;
1406 sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1407 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
1408 spin_unlock(&sbi->s_lock);
1409
1410 return 0;
1411}
1412
1413static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1414{
1415 struct super_block *sb = dentry->d_sb;
1416 struct ext2_sb_info *sbi = EXT2_SB(sb);
1417 struct ext2_super_block *es = sbi->s_es;
1418 u64 fsid;
1419
1420 spin_lock(&sbi->s_lock);
1421
1422 if (test_opt (sb, MINIX_DF))
1423 sbi->s_overhead_last = 0;
1424 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1425 unsigned long i, overhead = 0;
1426 smp_rmb();
1427
1428 /*
1429 * Compute the overhead (FS structures). This is constant
1430 * for a given filesystem unless the number of block groups
1431 * changes so we cache the previous value until it does.
1432 */
1433
1434 /*
1435 * All of the blocks before first_data_block are
1436 * overhead
1437 */
1438 overhead = le32_to_cpu(es->s_first_data_block);
1439
1440 /*
1441 * Add the overhead attributed to the superblock and
1442 * block group descriptors. If the sparse superblocks
1443 * feature is turned on, then not all groups have this.
1444 */
1445 for (i = 0; i < sbi->s_groups_count; i++)
1446 overhead += ext2_bg_has_super(sb, i) +
1447 ext2_bg_num_gdb(sb, i);
1448
1449 /*
1450 * Every block group has an inode bitmap, a block
1451 * bitmap, and an inode table.
1452 */
1453 overhead += (sbi->s_groups_count *
1454 (2 + sbi->s_itb_per_group));
1455 sbi->s_overhead_last = overhead;
1456 smp_wmb();
1457 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1458 }
1459
1460 buf->f_type = EXT2_SUPER_MAGIC;
1461 buf->f_bsize = sb->s_blocksize;
1462 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1463 buf->f_bfree = ext2_count_free_blocks(sb);
1464 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1465 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1466 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1467 buf->f_bavail = 0;
1468 buf->f_files = le32_to_cpu(es->s_inodes_count);
1469 buf->f_ffree = ext2_count_free_inodes(sb);
1470 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1471 buf->f_namelen = EXT2_NAME_LEN;
1472 fsid = le64_to_cpup((void *)es->s_uuid) ^
1473 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1474 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1475 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1476 spin_unlock(&sbi->s_lock);
1477 return 0;
1478}
1479
1480static struct dentry *ext2_mount(struct file_system_type *fs_type,
1481 int flags, const char *dev_name, void *data)
1482{
1483 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1484}
1485
1486#ifdef CONFIG_QUOTA
1487
1488/* Read data from quotafile - avoid pagecache and such because we cannot afford
1489 * acquiring the locks... As quota files are never truncated and quota code
1490 * itself serializes the operations (and no one else should touch the files)
1491 * we don't have to be afraid of races */
1492static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1493 size_t len, loff_t off)
1494{
1495 struct inode *inode = sb_dqopt(sb)->files[type];
1496 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1497 int err = 0;
1498 int offset = off & (sb->s_blocksize - 1);
1499 int tocopy;
1500 size_t toread;
1501 struct buffer_head tmp_bh;
1502 struct buffer_head *bh;
1503 loff_t i_size = i_size_read(inode);
1504
1505 if (off > i_size)
1506 return 0;
1507 if (off+len > i_size)
1508 len = i_size-off;
1509 toread = len;
1510 while (toread > 0) {
1511 tocopy = sb->s_blocksize - offset < toread ?
1512 sb->s_blocksize - offset : toread;
1513
1514 tmp_bh.b_state = 0;
1515 tmp_bh.b_size = sb->s_blocksize;
1516 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1517 if (err < 0)
1518 return err;
1519 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1520 memset(data, 0, tocopy);
1521 else {
1522 bh = sb_bread(sb, tmp_bh.b_blocknr);
1523 if (!bh)
1524 return -EIO;
1525 memcpy(data, bh->b_data+offset, tocopy);
1526 brelse(bh);
1527 }
1528 offset = 0;
1529 toread -= tocopy;
1530 data += tocopy;
1531 blk++;
1532 }
1533 return len;
1534}
1535
1536/* Write to quotafile */
1537static ssize_t ext2_quota_write(struct super_block *sb, int type,
1538 const char *data, size_t len, loff_t off)
1539{
1540 struct inode *inode = sb_dqopt(sb)->files[type];
1541 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1542 int err = 0;
1543 int offset = off & (sb->s_blocksize - 1);
1544 int tocopy;
1545 size_t towrite = len;
1546 struct buffer_head tmp_bh;
1547 struct buffer_head *bh;
1548
1549 while (towrite > 0) {
1550 tocopy = sb->s_blocksize - offset < towrite ?
1551 sb->s_blocksize - offset : towrite;
1552
1553 tmp_bh.b_state = 0;
1554 tmp_bh.b_size = sb->s_blocksize;
1555 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1556 if (err < 0)
1557 goto out;
1558 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1559 bh = sb_bread(sb, tmp_bh.b_blocknr);
1560 else
1561 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1562 if (unlikely(!bh)) {
1563 err = -EIO;
1564 goto out;
1565 }
1566 lock_buffer(bh);
1567 memcpy(bh->b_data+offset, data, tocopy);
1568 flush_dcache_page(bh->b_page);
1569 set_buffer_uptodate(bh);
1570 mark_buffer_dirty(bh);
1571 unlock_buffer(bh);
1572 brelse(bh);
1573 offset = 0;
1574 towrite -= tocopy;
1575 data += tocopy;
1576 blk++;
1577 }
1578out:
1579 if (len == towrite)
1580 return err;
1581 if (inode->i_size < off+len-towrite)
1582 i_size_write(inode, off+len-towrite);
1583 inode_inc_iversion(inode);
1584 inode->i_mtime = inode->i_ctime = current_time(inode);
1585 mark_inode_dirty(inode);
1586 return len - towrite;
1587}
1588
1589static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1590 const struct path *path)
1591{
1592 int err;
1593 struct inode *inode;
1594
1595 err = dquot_quota_on(sb, type, format_id, path);
1596 if (err)
1597 return err;
1598
1599 inode = d_inode(path->dentry);
1600 inode_lock(inode);
1601 EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1602 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1603 S_NOATIME | S_IMMUTABLE);
1604 inode_unlock(inode);
1605 mark_inode_dirty(inode);
1606
1607 return 0;
1608}
1609
1610static int ext2_quota_off(struct super_block *sb, int type)
1611{
1612 struct inode *inode = sb_dqopt(sb)->files[type];
1613 int err;
1614
1615 if (!inode || !igrab(inode))
1616 goto out;
1617
1618 err = dquot_quota_off(sb, type);
1619 if (err)
1620 goto out_put;
1621
1622 inode_lock(inode);
1623 EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1624 inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1625 inode_unlock(inode);
1626 mark_inode_dirty(inode);
1627out_put:
1628 iput(inode);
1629 return err;
1630out:
1631 return dquot_quota_off(sb, type);
1632}
1633
1634#endif
1635
1636static struct file_system_type ext2_fs_type = {
1637 .owner = THIS_MODULE,
1638 .name = "ext2",
1639 .mount = ext2_mount,
1640 .kill_sb = kill_block_super,
1641 .fs_flags = FS_REQUIRES_DEV,
1642};
1643MODULE_ALIAS_FS("ext2");
1644
1645static int __init init_ext2_fs(void)
1646{
1647 int err;
1648
1649 err = init_inodecache();
1650 if (err)
1651 return err;
1652 err = register_filesystem(&ext2_fs_type);
1653 if (err)
1654 goto out;
1655 return 0;
1656out:
1657 destroy_inodecache();
1658 return err;
1659}
1660
1661static void __exit exit_ext2_fs(void)
1662{
1663 unregister_filesystem(&ext2_fs_type);
1664 destroy_inodecache();
1665}
1666
1667MODULE_AUTHOR("Remy Card and others");
1668MODULE_DESCRIPTION("Second Extended Filesystem");
1669MODULE_LICENSE("GPL");
1670module_init(init_ext2_fs)
1671module_exit(exit_ext2_fs)
1/*
2 * linux/fs/ext2/super.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/inode.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Big-endian to little-endian byte-swapping/bitmaps by
16 * David S. Miller (davem@caip.rutgers.edu), 1995
17 */
18
19#include <linux/module.h>
20#include <linux/string.h>
21#include <linux/fs.h>
22#include <linux/slab.h>
23#include <linux/init.h>
24#include <linux/blkdev.h>
25#include <linux/parser.h>
26#include <linux/random.h>
27#include <linux/buffer_head.h>
28#include <linux/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 <linux/uaccess.h>
35#include "ext2.h"
36#include "xattr.h"
37#include "acl.h"
38
39static void ext2_sync_super(struct super_block *sb,
40 struct ext2_super_block *es, int wait);
41static int ext2_remount (struct super_block * sb, int * flags, char * data);
42static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
43static int ext2_sync_fs(struct super_block *sb, int wait);
44static int ext2_freeze(struct super_block *sb);
45static int ext2_unfreeze(struct super_block *sb);
46
47void ext2_error(struct super_block *sb, const char *function,
48 const char *fmt, ...)
49{
50 struct va_format vaf;
51 va_list args;
52 struct ext2_sb_info *sbi = EXT2_SB(sb);
53 struct ext2_super_block *es = sbi->s_es;
54
55 if (!(sb->s_flags & MS_RDONLY)) {
56 spin_lock(&sbi->s_lock);
57 sbi->s_mount_state |= EXT2_ERROR_FS;
58 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
59 spin_unlock(&sbi->s_lock);
60 ext2_sync_super(sb, es, 1);
61 }
62
63 va_start(args, fmt);
64
65 vaf.fmt = fmt;
66 vaf.va = &args;
67
68 printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
69 sb->s_id, function, &vaf);
70
71 va_end(args);
72
73 if (test_opt(sb, ERRORS_PANIC))
74 panic("EXT2-fs: panic from previous error\n");
75 if (test_opt(sb, ERRORS_RO)) {
76 ext2_msg(sb, KERN_CRIT,
77 "error: remounting filesystem read-only");
78 sb->s_flags |= MS_RDONLY;
79 }
80}
81
82void ext2_msg(struct super_block *sb, const char *prefix,
83 const char *fmt, ...)
84{
85 struct va_format vaf;
86 va_list args;
87
88 va_start(args, fmt);
89
90 vaf.fmt = fmt;
91 vaf.va = &args;
92
93 printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
94
95 va_end(args);
96}
97
98/*
99 * This must be called with sbi->s_lock held.
100 */
101void ext2_update_dynamic_rev(struct super_block *sb)
102{
103 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
104
105 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
106 return;
107
108 ext2_msg(sb, KERN_WARNING,
109 "warning: updating to rev %d because of "
110 "new feature flag, running e2fsck is recommended",
111 EXT2_DYNAMIC_REV);
112
113 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
114 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
115 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
116 /* leave es->s_feature_*compat flags alone */
117 /* es->s_uuid will be set by e2fsck if empty */
118
119 /*
120 * The rest of the superblock fields should be zero, and if not it
121 * means they are likely already in use, so leave them alone. We
122 * can leave it up to e2fsck to clean up any inconsistencies there.
123 */
124}
125
126static void ext2_put_super (struct super_block * sb)
127{
128 int db_count;
129 int i;
130 struct ext2_sb_info *sbi = EXT2_SB(sb);
131
132 dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
133
134 if (sbi->s_mb_cache) {
135 ext2_xattr_destroy_cache(sbi->s_mb_cache);
136 sbi->s_mb_cache = NULL;
137 }
138 if (!(sb->s_flags & MS_RDONLY)) {
139 struct ext2_super_block *es = sbi->s_es;
140
141 spin_lock(&sbi->s_lock);
142 es->s_state = cpu_to_le16(sbi->s_mount_state);
143 spin_unlock(&sbi->s_lock);
144 ext2_sync_super(sb, es, 1);
145 }
146 db_count = sbi->s_gdb_count;
147 for (i = 0; i < db_count; i++)
148 if (sbi->s_group_desc[i])
149 brelse (sbi->s_group_desc[i]);
150 kfree(sbi->s_group_desc);
151 kfree(sbi->s_debts);
152 percpu_counter_destroy(&sbi->s_freeblocks_counter);
153 percpu_counter_destroy(&sbi->s_freeinodes_counter);
154 percpu_counter_destroy(&sbi->s_dirs_counter);
155 brelse (sbi->s_sbh);
156 sb->s_fs_info = NULL;
157 kfree(sbi->s_blockgroup_lock);
158 kfree(sbi);
159}
160
161static struct kmem_cache * ext2_inode_cachep;
162
163static struct inode *ext2_alloc_inode(struct super_block *sb)
164{
165 struct ext2_inode_info *ei;
166 ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
167 if (!ei)
168 return NULL;
169 ei->i_block_alloc_info = NULL;
170 ei->vfs_inode.i_version = 1;
171#ifdef CONFIG_QUOTA
172 memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
173#endif
174
175 return &ei->vfs_inode;
176}
177
178static void ext2_i_callback(struct rcu_head *head)
179{
180 struct inode *inode = container_of(head, struct inode, i_rcu);
181 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
182}
183
184static void ext2_destroy_inode(struct inode *inode)
185{
186 call_rcu(&inode->i_rcu, ext2_i_callback);
187}
188
189static void init_once(void *foo)
190{
191 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
192
193 rwlock_init(&ei->i_meta_lock);
194#ifdef CONFIG_EXT2_FS_XATTR
195 init_rwsem(&ei->xattr_sem);
196#endif
197 mutex_init(&ei->truncate_mutex);
198#ifdef CONFIG_FS_DAX
199 init_rwsem(&ei->dax_sem);
200#endif
201 inode_init_once(&ei->vfs_inode);
202}
203
204static int __init init_inodecache(void)
205{
206 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
207 sizeof(struct ext2_inode_info),
208 0, (SLAB_RECLAIM_ACCOUNT|
209 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
210 init_once);
211 if (ext2_inode_cachep == NULL)
212 return -ENOMEM;
213 return 0;
214}
215
216static void destroy_inodecache(void)
217{
218 /*
219 * Make sure all delayed rcu free inodes are flushed before we
220 * destroy cache.
221 */
222 rcu_barrier();
223 kmem_cache_destroy(ext2_inode_cachep);
224}
225
226static int ext2_show_options(struct seq_file *seq, struct dentry *root)
227{
228 struct super_block *sb = root->d_sb;
229 struct ext2_sb_info *sbi = EXT2_SB(sb);
230 struct ext2_super_block *es = sbi->s_es;
231 unsigned long def_mount_opts;
232
233 spin_lock(&sbi->s_lock);
234 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
235
236 if (sbi->s_sb_block != 1)
237 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
238 if (test_opt(sb, MINIX_DF))
239 seq_puts(seq, ",minixdf");
240 if (test_opt(sb, GRPID))
241 seq_puts(seq, ",grpid");
242 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
243 seq_puts(seq, ",nogrpid");
244 if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
245 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
246 seq_printf(seq, ",resuid=%u",
247 from_kuid_munged(&init_user_ns, sbi->s_resuid));
248 }
249 if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
250 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
251 seq_printf(seq, ",resgid=%u",
252 from_kgid_munged(&init_user_ns, sbi->s_resgid));
253 }
254 if (test_opt(sb, ERRORS_RO)) {
255 int def_errors = le16_to_cpu(es->s_errors);
256
257 if (def_errors == EXT2_ERRORS_PANIC ||
258 def_errors == EXT2_ERRORS_CONTINUE) {
259 seq_puts(seq, ",errors=remount-ro");
260 }
261 }
262 if (test_opt(sb, ERRORS_CONT))
263 seq_puts(seq, ",errors=continue");
264 if (test_opt(sb, ERRORS_PANIC))
265 seq_puts(seq, ",errors=panic");
266 if (test_opt(sb, NO_UID32))
267 seq_puts(seq, ",nouid32");
268 if (test_opt(sb, DEBUG))
269 seq_puts(seq, ",debug");
270 if (test_opt(sb, OLDALLOC))
271 seq_puts(seq, ",oldalloc");
272
273#ifdef CONFIG_EXT2_FS_XATTR
274 if (test_opt(sb, XATTR_USER))
275 seq_puts(seq, ",user_xattr");
276 if (!test_opt(sb, XATTR_USER) &&
277 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
278 seq_puts(seq, ",nouser_xattr");
279 }
280#endif
281
282#ifdef CONFIG_EXT2_FS_POSIX_ACL
283 if (test_opt(sb, POSIX_ACL))
284 seq_puts(seq, ",acl");
285 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
286 seq_puts(seq, ",noacl");
287#endif
288
289 if (test_opt(sb, NOBH))
290 seq_puts(seq, ",nobh");
291
292#if defined(CONFIG_QUOTA)
293 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
294 seq_puts(seq, ",usrquota");
295
296 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
297 seq_puts(seq, ",grpquota");
298#endif
299
300#ifdef CONFIG_FS_DAX
301 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
302 seq_puts(seq, ",xip");
303 if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
304 seq_puts(seq, ",dax");
305#endif
306
307 if (!test_opt(sb, RESERVATION))
308 seq_puts(seq, ",noreservation");
309
310 spin_unlock(&sbi->s_lock);
311 return 0;
312}
313
314#ifdef CONFIG_QUOTA
315static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
316static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
317static struct dquot **ext2_get_dquots(struct inode *inode)
318{
319 return EXT2_I(inode)->i_dquot;
320}
321#endif
322
323static const struct super_operations ext2_sops = {
324 .alloc_inode = ext2_alloc_inode,
325 .destroy_inode = ext2_destroy_inode,
326 .write_inode = ext2_write_inode,
327 .evict_inode = ext2_evict_inode,
328 .put_super = ext2_put_super,
329 .sync_fs = ext2_sync_fs,
330 .freeze_fs = ext2_freeze,
331 .unfreeze_fs = ext2_unfreeze,
332 .statfs = ext2_statfs,
333 .remount_fs = ext2_remount,
334 .show_options = ext2_show_options,
335#ifdef CONFIG_QUOTA
336 .quota_read = ext2_quota_read,
337 .quota_write = ext2_quota_write,
338 .get_dquots = ext2_get_dquots,
339#endif
340};
341
342static struct inode *ext2_nfs_get_inode(struct super_block *sb,
343 u64 ino, u32 generation)
344{
345 struct inode *inode;
346
347 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
348 return ERR_PTR(-ESTALE);
349 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
350 return ERR_PTR(-ESTALE);
351
352 /*
353 * ext2_iget isn't quite right if the inode is currently unallocated!
354 * However ext2_iget currently does appropriate checks to handle stale
355 * inodes so everything is OK.
356 */
357 inode = ext2_iget(sb, ino);
358 if (IS_ERR(inode))
359 return ERR_CAST(inode);
360 if (generation && inode->i_generation != generation) {
361 /* we didn't find the right inode.. */
362 iput(inode);
363 return ERR_PTR(-ESTALE);
364 }
365 return inode;
366}
367
368static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
369 int fh_len, int fh_type)
370{
371 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
372 ext2_nfs_get_inode);
373}
374
375static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
376 int fh_len, int fh_type)
377{
378 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
379 ext2_nfs_get_inode);
380}
381
382static const struct export_operations ext2_export_ops = {
383 .fh_to_dentry = ext2_fh_to_dentry,
384 .fh_to_parent = ext2_fh_to_parent,
385 .get_parent = ext2_get_parent,
386};
387
388static unsigned long get_sb_block(void **data)
389{
390 unsigned long sb_block;
391 char *options = (char *) *data;
392
393 if (!options || strncmp(options, "sb=", 3) != 0)
394 return 1; /* Default location */
395 options += 3;
396 sb_block = simple_strtoul(options, &options, 0);
397 if (*options && *options != ',') {
398 printk("EXT2-fs: Invalid sb specification: %s\n",
399 (char *) *data);
400 return 1;
401 }
402 if (*options == ',')
403 options++;
404 *data = (void *) options;
405 return sb_block;
406}
407
408enum {
409 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
410 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
411 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
412 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
413 Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
414 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
415};
416
417static const match_table_t tokens = {
418 {Opt_bsd_df, "bsddf"},
419 {Opt_minix_df, "minixdf"},
420 {Opt_grpid, "grpid"},
421 {Opt_grpid, "bsdgroups"},
422 {Opt_nogrpid, "nogrpid"},
423 {Opt_nogrpid, "sysvgroups"},
424 {Opt_resgid, "resgid=%u"},
425 {Opt_resuid, "resuid=%u"},
426 {Opt_sb, "sb=%u"},
427 {Opt_err_cont, "errors=continue"},
428 {Opt_err_panic, "errors=panic"},
429 {Opt_err_ro, "errors=remount-ro"},
430 {Opt_nouid32, "nouid32"},
431 {Opt_nocheck, "check=none"},
432 {Opt_nocheck, "nocheck"},
433 {Opt_debug, "debug"},
434 {Opt_oldalloc, "oldalloc"},
435 {Opt_orlov, "orlov"},
436 {Opt_nobh, "nobh"},
437 {Opt_user_xattr, "user_xattr"},
438 {Opt_nouser_xattr, "nouser_xattr"},
439 {Opt_acl, "acl"},
440 {Opt_noacl, "noacl"},
441 {Opt_xip, "xip"},
442 {Opt_dax, "dax"},
443 {Opt_grpquota, "grpquota"},
444 {Opt_ignore, "noquota"},
445 {Opt_quota, "quota"},
446 {Opt_usrquota, "usrquota"},
447 {Opt_reservation, "reservation"},
448 {Opt_noreservation, "noreservation"},
449 {Opt_err, NULL}
450};
451
452static int parse_options(char *options, struct super_block *sb)
453{
454 char *p;
455 struct ext2_sb_info *sbi = EXT2_SB(sb);
456 substring_t args[MAX_OPT_ARGS];
457 int option;
458 kuid_t uid;
459 kgid_t gid;
460
461 if (!options)
462 return 1;
463
464 while ((p = strsep (&options, ",")) != NULL) {
465 int token;
466 if (!*p)
467 continue;
468
469 token = match_token(p, tokens, args);
470 switch (token) {
471 case Opt_bsd_df:
472 clear_opt (sbi->s_mount_opt, MINIX_DF);
473 break;
474 case Opt_minix_df:
475 set_opt (sbi->s_mount_opt, MINIX_DF);
476 break;
477 case Opt_grpid:
478 set_opt (sbi->s_mount_opt, GRPID);
479 break;
480 case Opt_nogrpid:
481 clear_opt (sbi->s_mount_opt, GRPID);
482 break;
483 case Opt_resuid:
484 if (match_int(&args[0], &option))
485 return 0;
486 uid = make_kuid(current_user_ns(), option);
487 if (!uid_valid(uid)) {
488 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
489 return 0;
490
491 }
492 sbi->s_resuid = uid;
493 break;
494 case Opt_resgid:
495 if (match_int(&args[0], &option))
496 return 0;
497 gid = make_kgid(current_user_ns(), option);
498 if (!gid_valid(gid)) {
499 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
500 return 0;
501 }
502 sbi->s_resgid = gid;
503 break;
504 case Opt_sb:
505 /* handled by get_sb_block() instead of here */
506 /* *sb_block = match_int(&args[0]); */
507 break;
508 case Opt_err_panic:
509 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
510 clear_opt (sbi->s_mount_opt, ERRORS_RO);
511 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
512 break;
513 case Opt_err_ro:
514 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
515 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
516 set_opt (sbi->s_mount_opt, ERRORS_RO);
517 break;
518 case Opt_err_cont:
519 clear_opt (sbi->s_mount_opt, ERRORS_RO);
520 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
521 set_opt (sbi->s_mount_opt, ERRORS_CONT);
522 break;
523 case Opt_nouid32:
524 set_opt (sbi->s_mount_opt, NO_UID32);
525 break;
526 case Opt_nocheck:
527 clear_opt (sbi->s_mount_opt, CHECK);
528 break;
529 case Opt_debug:
530 set_opt (sbi->s_mount_opt, DEBUG);
531 break;
532 case Opt_oldalloc:
533 set_opt (sbi->s_mount_opt, OLDALLOC);
534 break;
535 case Opt_orlov:
536 clear_opt (sbi->s_mount_opt, OLDALLOC);
537 break;
538 case Opt_nobh:
539 set_opt (sbi->s_mount_opt, NOBH);
540 break;
541#ifdef CONFIG_EXT2_FS_XATTR
542 case Opt_user_xattr:
543 set_opt (sbi->s_mount_opt, XATTR_USER);
544 break;
545 case Opt_nouser_xattr:
546 clear_opt (sbi->s_mount_opt, XATTR_USER);
547 break;
548#else
549 case Opt_user_xattr:
550 case Opt_nouser_xattr:
551 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
552 "not supported");
553 break;
554#endif
555#ifdef CONFIG_EXT2_FS_POSIX_ACL
556 case Opt_acl:
557 set_opt(sbi->s_mount_opt, POSIX_ACL);
558 break;
559 case Opt_noacl:
560 clear_opt(sbi->s_mount_opt, POSIX_ACL);
561 break;
562#else
563 case Opt_acl:
564 case Opt_noacl:
565 ext2_msg(sb, KERN_INFO,
566 "(no)acl options not supported");
567 break;
568#endif
569 case Opt_xip:
570 ext2_msg(sb, KERN_INFO, "use dax instead of xip");
571 set_opt(sbi->s_mount_opt, XIP);
572 /* Fall through */
573 case Opt_dax:
574#ifdef CONFIG_FS_DAX
575 ext2_msg(sb, KERN_WARNING,
576 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
577 set_opt(sbi->s_mount_opt, DAX);
578#else
579 ext2_msg(sb, KERN_INFO, "dax option not supported");
580#endif
581 break;
582
583#if defined(CONFIG_QUOTA)
584 case Opt_quota:
585 case Opt_usrquota:
586 set_opt(sbi->s_mount_opt, USRQUOTA);
587 break;
588
589 case Opt_grpquota:
590 set_opt(sbi->s_mount_opt, GRPQUOTA);
591 break;
592#else
593 case Opt_quota:
594 case Opt_usrquota:
595 case Opt_grpquota:
596 ext2_msg(sb, KERN_INFO,
597 "quota operations not supported");
598 break;
599#endif
600
601 case Opt_reservation:
602 set_opt(sbi->s_mount_opt, RESERVATION);
603 ext2_msg(sb, KERN_INFO, "reservations ON");
604 break;
605 case Opt_noreservation:
606 clear_opt(sbi->s_mount_opt, RESERVATION);
607 ext2_msg(sb, KERN_INFO, "reservations OFF");
608 break;
609 case Opt_ignore:
610 break;
611 default:
612 return 0;
613 }
614 }
615 return 1;
616}
617
618static int ext2_setup_super (struct super_block * sb,
619 struct ext2_super_block * es,
620 int read_only)
621{
622 int res = 0;
623 struct ext2_sb_info *sbi = EXT2_SB(sb);
624
625 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
626 ext2_msg(sb, KERN_ERR,
627 "error: revision level too high, "
628 "forcing read-only mode");
629 res = MS_RDONLY;
630 }
631 if (read_only)
632 return res;
633 if (!(sbi->s_mount_state & EXT2_VALID_FS))
634 ext2_msg(sb, KERN_WARNING,
635 "warning: mounting unchecked fs, "
636 "running e2fsck is recommended");
637 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
638 ext2_msg(sb, KERN_WARNING,
639 "warning: mounting fs with errors, "
640 "running e2fsck is recommended");
641 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
642 le16_to_cpu(es->s_mnt_count) >=
643 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
644 ext2_msg(sb, KERN_WARNING,
645 "warning: maximal mount count reached, "
646 "running e2fsck is recommended");
647 else if (le32_to_cpu(es->s_checkinterval) &&
648 (le32_to_cpu(es->s_lastcheck) +
649 le32_to_cpu(es->s_checkinterval) <= get_seconds()))
650 ext2_msg(sb, KERN_WARNING,
651 "warning: checktime reached, "
652 "running e2fsck is recommended");
653 if (!le16_to_cpu(es->s_max_mnt_count))
654 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
655 le16_add_cpu(&es->s_mnt_count, 1);
656 if (test_opt (sb, DEBUG))
657 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
658 "bpg=%lu, ipg=%lu, mo=%04lx]",
659 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
660 sbi->s_frag_size,
661 sbi->s_groups_count,
662 EXT2_BLOCKS_PER_GROUP(sb),
663 EXT2_INODES_PER_GROUP(sb),
664 sbi->s_mount_opt);
665 return res;
666}
667
668static int ext2_check_descriptors(struct super_block *sb)
669{
670 int i;
671 struct ext2_sb_info *sbi = EXT2_SB(sb);
672
673 ext2_debug ("Checking group descriptors");
674
675 for (i = 0; i < sbi->s_groups_count; i++) {
676 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
677 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
678 ext2_fsblk_t last_block;
679
680 if (i == sbi->s_groups_count - 1)
681 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
682 else
683 last_block = first_block +
684 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
685
686 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
687 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
688 {
689 ext2_error (sb, "ext2_check_descriptors",
690 "Block bitmap for group %d"
691 " not in group (block %lu)!",
692 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
693 return 0;
694 }
695 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
696 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
697 {
698 ext2_error (sb, "ext2_check_descriptors",
699 "Inode bitmap for group %d"
700 " not in group (block %lu)!",
701 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
702 return 0;
703 }
704 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
705 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
706 last_block)
707 {
708 ext2_error (sb, "ext2_check_descriptors",
709 "Inode table for group %d"
710 " not in group (block %lu)!",
711 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
712 return 0;
713 }
714 }
715 return 1;
716}
717
718/*
719 * Maximal file size. There is a direct, and {,double-,triple-}indirect
720 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
721 * We need to be 1 filesystem block less than the 2^32 sector limit.
722 */
723static loff_t ext2_max_size(int bits)
724{
725 loff_t res = EXT2_NDIR_BLOCKS;
726 int meta_blocks;
727 loff_t upper_limit;
728
729 /* This is calculated to be the largest file size for a
730 * dense, file such that the total number of
731 * sectors in the file, including data and all indirect blocks,
732 * does not exceed 2^32 -1
733 * __u32 i_blocks representing the total number of
734 * 512 bytes blocks of the file
735 */
736 upper_limit = (1LL << 32) - 1;
737
738 /* total blocks in file system block size */
739 upper_limit >>= (bits - 9);
740
741
742 /* indirect blocks */
743 meta_blocks = 1;
744 /* double indirect blocks */
745 meta_blocks += 1 + (1LL << (bits-2));
746 /* tripple indirect blocks */
747 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
748
749 upper_limit -= meta_blocks;
750 upper_limit <<= bits;
751
752 res += 1LL << (bits-2);
753 res += 1LL << (2*(bits-2));
754 res += 1LL << (3*(bits-2));
755 res <<= bits;
756 if (res > upper_limit)
757 res = upper_limit;
758
759 if (res > MAX_LFS_FILESIZE)
760 res = MAX_LFS_FILESIZE;
761
762 return res;
763}
764
765static unsigned long descriptor_loc(struct super_block *sb,
766 unsigned long logic_sb_block,
767 int nr)
768{
769 struct ext2_sb_info *sbi = EXT2_SB(sb);
770 unsigned long bg, first_meta_bg;
771 int has_super = 0;
772
773 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
774
775 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
776 nr < first_meta_bg)
777 return (logic_sb_block + nr + 1);
778 bg = sbi->s_desc_per_block * nr;
779 if (ext2_bg_has_super(sb, bg))
780 has_super = 1;
781
782 return ext2_group_first_block_no(sb, bg) + has_super;
783}
784
785static int ext2_fill_super(struct super_block *sb, void *data, int silent)
786{
787 struct buffer_head * bh;
788 struct ext2_sb_info * sbi;
789 struct ext2_super_block * es;
790 struct inode *root;
791 unsigned long block;
792 unsigned long sb_block = get_sb_block(&data);
793 unsigned long logic_sb_block;
794 unsigned long offset = 0;
795 unsigned long def_mount_opts;
796 long ret = -EINVAL;
797 int blocksize = BLOCK_SIZE;
798 int db_count;
799 int i, j;
800 __le32 features;
801 int err;
802
803 err = -ENOMEM;
804 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
805 if (!sbi)
806 goto failed;
807
808 sbi->s_blockgroup_lock =
809 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
810 if (!sbi->s_blockgroup_lock) {
811 kfree(sbi);
812 goto failed;
813 }
814 sb->s_fs_info = sbi;
815 sbi->s_sb_block = sb_block;
816
817 spin_lock_init(&sbi->s_lock);
818
819 /*
820 * See what the current blocksize for the device is, and
821 * use that as the blocksize. Otherwise (or if the blocksize
822 * is smaller than the default) use the default.
823 * This is important for devices that have a hardware
824 * sectorsize that is larger than the default.
825 */
826 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
827 if (!blocksize) {
828 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
829 goto failed_sbi;
830 }
831
832 /*
833 * If the superblock doesn't start on a hardware sector boundary,
834 * calculate the offset.
835 */
836 if (blocksize != BLOCK_SIZE) {
837 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
838 offset = (sb_block*BLOCK_SIZE) % blocksize;
839 } else {
840 logic_sb_block = sb_block;
841 }
842
843 if (!(bh = sb_bread(sb, logic_sb_block))) {
844 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
845 goto failed_sbi;
846 }
847 /*
848 * Note: s_es must be initialized as soon as possible because
849 * some ext2 macro-instructions depend on its value
850 */
851 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
852 sbi->s_es = es;
853 sb->s_magic = le16_to_cpu(es->s_magic);
854
855 if (sb->s_magic != EXT2_SUPER_MAGIC)
856 goto cantfind_ext2;
857
858 /* Set defaults before we parse the mount options */
859 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
860 if (def_mount_opts & EXT2_DEFM_DEBUG)
861 set_opt(sbi->s_mount_opt, DEBUG);
862 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
863 set_opt(sbi->s_mount_opt, GRPID);
864 if (def_mount_opts & EXT2_DEFM_UID16)
865 set_opt(sbi->s_mount_opt, NO_UID32);
866#ifdef CONFIG_EXT2_FS_XATTR
867 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
868 set_opt(sbi->s_mount_opt, XATTR_USER);
869#endif
870#ifdef CONFIG_EXT2_FS_POSIX_ACL
871 if (def_mount_opts & EXT2_DEFM_ACL)
872 set_opt(sbi->s_mount_opt, POSIX_ACL);
873#endif
874
875 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
876 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
877 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
878 set_opt(sbi->s_mount_opt, ERRORS_CONT);
879 else
880 set_opt(sbi->s_mount_opt, ERRORS_RO);
881
882 sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
883 sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
884
885 set_opt(sbi->s_mount_opt, RESERVATION);
886
887 if (!parse_options((char *) data, sb))
888 goto failed_mount;
889
890 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
891 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
892 MS_POSIXACL : 0);
893 sb->s_iflags |= SB_I_CGROUPWB;
894
895 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
896 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
897 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
898 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
899 ext2_msg(sb, KERN_WARNING,
900 "warning: feature flags set on rev 0 fs, "
901 "running e2fsck is recommended");
902 /*
903 * Check feature flags regardless of the revision level, since we
904 * previously didn't change the revision level when setting the flags,
905 * so there is a chance incompat flags are set on a rev 0 filesystem.
906 */
907 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
908 if (features) {
909 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
910 "unsupported optional features (%x)",
911 le32_to_cpu(features));
912 goto failed_mount;
913 }
914 if (!(sb->s_flags & MS_RDONLY) &&
915 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
916 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
917 "unsupported optional features (%x)",
918 le32_to_cpu(features));
919 goto failed_mount;
920 }
921
922 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
923
924 if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
925 err = bdev_dax_supported(sb, blocksize);
926 if (err)
927 goto failed_mount;
928 }
929
930 /* If the blocksize doesn't match, re-read the thing.. */
931 if (sb->s_blocksize != blocksize) {
932 brelse(bh);
933
934 if (!sb_set_blocksize(sb, blocksize)) {
935 ext2_msg(sb, KERN_ERR,
936 "error: bad blocksize %d", blocksize);
937 goto failed_sbi;
938 }
939
940 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
941 offset = (sb_block*BLOCK_SIZE) % blocksize;
942 bh = sb_bread(sb, logic_sb_block);
943 if(!bh) {
944 ext2_msg(sb, KERN_ERR, "error: couldn't read"
945 "superblock on 2nd try");
946 goto failed_sbi;
947 }
948 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
949 sbi->s_es = es;
950 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
951 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
952 goto failed_mount;
953 }
954 }
955
956 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
957 sb->s_max_links = EXT2_LINK_MAX;
958
959 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
960 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
961 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
962 } else {
963 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
964 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
965 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
966 !is_power_of_2(sbi->s_inode_size) ||
967 (sbi->s_inode_size > blocksize)) {
968 ext2_msg(sb, KERN_ERR,
969 "error: unsupported inode size: %d",
970 sbi->s_inode_size);
971 goto failed_mount;
972 }
973 }
974
975 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
976 le32_to_cpu(es->s_log_frag_size);
977 if (sbi->s_frag_size == 0)
978 goto cantfind_ext2;
979 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
980
981 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
982 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
983 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
984
985 if (EXT2_INODE_SIZE(sb) == 0)
986 goto cantfind_ext2;
987 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
988 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
989 goto cantfind_ext2;
990 sbi->s_itb_per_group = sbi->s_inodes_per_group /
991 sbi->s_inodes_per_block;
992 sbi->s_desc_per_block = sb->s_blocksize /
993 sizeof (struct ext2_group_desc);
994 sbi->s_sbh = bh;
995 sbi->s_mount_state = le16_to_cpu(es->s_state);
996 sbi->s_addr_per_block_bits =
997 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
998 sbi->s_desc_per_block_bits =
999 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1000
1001 if (sb->s_magic != EXT2_SUPER_MAGIC)
1002 goto cantfind_ext2;
1003
1004 if (sb->s_blocksize != bh->b_size) {
1005 if (!silent)
1006 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1007 goto failed_mount;
1008 }
1009
1010 if (sb->s_blocksize != sbi->s_frag_size) {
1011 ext2_msg(sb, KERN_ERR,
1012 "error: fragsize %lu != blocksize %lu"
1013 "(not supported yet)",
1014 sbi->s_frag_size, sb->s_blocksize);
1015 goto failed_mount;
1016 }
1017
1018 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1019 ext2_msg(sb, KERN_ERR,
1020 "error: #blocks per group too big: %lu",
1021 sbi->s_blocks_per_group);
1022 goto failed_mount;
1023 }
1024 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1025 ext2_msg(sb, KERN_ERR,
1026 "error: #fragments per group too big: %lu",
1027 sbi->s_frags_per_group);
1028 goto failed_mount;
1029 }
1030 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1031 ext2_msg(sb, KERN_ERR,
1032 "error: #inodes per group too big: %lu",
1033 sbi->s_inodes_per_group);
1034 goto failed_mount;
1035 }
1036
1037 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1038 goto cantfind_ext2;
1039 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1040 le32_to_cpu(es->s_first_data_block) - 1)
1041 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1042 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1043 EXT2_DESC_PER_BLOCK(sb);
1044 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1045 if (sbi->s_group_desc == NULL) {
1046 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1047 goto failed_mount;
1048 }
1049 bgl_lock_init(sbi->s_blockgroup_lock);
1050 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1051 if (!sbi->s_debts) {
1052 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1053 goto failed_mount_group_desc;
1054 }
1055 for (i = 0; i < db_count; i++) {
1056 block = descriptor_loc(sb, logic_sb_block, i);
1057 sbi->s_group_desc[i] = sb_bread(sb, block);
1058 if (!sbi->s_group_desc[i]) {
1059 for (j = 0; j < i; j++)
1060 brelse (sbi->s_group_desc[j]);
1061 ext2_msg(sb, KERN_ERR,
1062 "error: unable to read group descriptors");
1063 goto failed_mount_group_desc;
1064 }
1065 }
1066 if (!ext2_check_descriptors (sb)) {
1067 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1068 goto failed_mount2;
1069 }
1070 sbi->s_gdb_count = db_count;
1071 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1072 spin_lock_init(&sbi->s_next_gen_lock);
1073
1074 /* per fileystem reservation list head & lock */
1075 spin_lock_init(&sbi->s_rsv_window_lock);
1076 sbi->s_rsv_window_root = RB_ROOT;
1077 /*
1078 * Add a single, static dummy reservation to the start of the
1079 * reservation window list --- it gives us a placeholder for
1080 * append-at-start-of-list which makes the allocation logic
1081 * _much_ simpler.
1082 */
1083 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1084 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1085 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1086 sbi->s_rsv_window_head.rsv_goal_size = 0;
1087 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1088
1089 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1090 ext2_count_free_blocks(sb), GFP_KERNEL);
1091 if (!err) {
1092 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1093 ext2_count_free_inodes(sb), GFP_KERNEL);
1094 }
1095 if (!err) {
1096 err = percpu_counter_init(&sbi->s_dirs_counter,
1097 ext2_count_dirs(sb), GFP_KERNEL);
1098 }
1099 if (err) {
1100 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1101 goto failed_mount3;
1102 }
1103
1104#ifdef CONFIG_EXT2_FS_XATTR
1105 sbi->s_mb_cache = ext2_xattr_create_cache();
1106 if (!sbi->s_mb_cache) {
1107 ext2_msg(sb, KERN_ERR, "Failed to create an mb_cache");
1108 goto failed_mount3;
1109 }
1110#endif
1111 /*
1112 * set up enough so that it can read an inode
1113 */
1114 sb->s_op = &ext2_sops;
1115 sb->s_export_op = &ext2_export_ops;
1116 sb->s_xattr = ext2_xattr_handlers;
1117
1118#ifdef CONFIG_QUOTA
1119 sb->dq_op = &dquot_operations;
1120 sb->s_qcop = &dquot_quotactl_ops;
1121 sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1122#endif
1123
1124 root = ext2_iget(sb, EXT2_ROOT_INO);
1125 if (IS_ERR(root)) {
1126 ret = PTR_ERR(root);
1127 goto failed_mount3;
1128 }
1129 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1130 iput(root);
1131 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1132 goto failed_mount3;
1133 }
1134
1135 sb->s_root = d_make_root(root);
1136 if (!sb->s_root) {
1137 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1138 ret = -ENOMEM;
1139 goto failed_mount3;
1140 }
1141 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1142 ext2_msg(sb, KERN_WARNING,
1143 "warning: mounting ext3 filesystem as ext2");
1144 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1145 sb->s_flags |= MS_RDONLY;
1146 ext2_write_super(sb);
1147 return 0;
1148
1149cantfind_ext2:
1150 if (!silent)
1151 ext2_msg(sb, KERN_ERR,
1152 "error: can't find an ext2 filesystem on dev %s.",
1153 sb->s_id);
1154 goto failed_mount;
1155failed_mount3:
1156 if (sbi->s_mb_cache)
1157 ext2_xattr_destroy_cache(sbi->s_mb_cache);
1158 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1159 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1160 percpu_counter_destroy(&sbi->s_dirs_counter);
1161failed_mount2:
1162 for (i = 0; i < db_count; i++)
1163 brelse(sbi->s_group_desc[i]);
1164failed_mount_group_desc:
1165 kfree(sbi->s_group_desc);
1166 kfree(sbi->s_debts);
1167failed_mount:
1168 brelse(bh);
1169failed_sbi:
1170 sb->s_fs_info = NULL;
1171 kfree(sbi->s_blockgroup_lock);
1172 kfree(sbi);
1173failed:
1174 return ret;
1175}
1176
1177static void ext2_clear_super_error(struct super_block *sb)
1178{
1179 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1180
1181 if (buffer_write_io_error(sbh)) {
1182 /*
1183 * Oh, dear. A previous attempt to write the
1184 * superblock failed. This could happen because the
1185 * USB device was yanked out. Or it could happen to
1186 * be a transient write error and maybe the block will
1187 * be remapped. Nothing we can do but to retry the
1188 * write and hope for the best.
1189 */
1190 ext2_msg(sb, KERN_ERR,
1191 "previous I/O error to superblock detected\n");
1192 clear_buffer_write_io_error(sbh);
1193 set_buffer_uptodate(sbh);
1194 }
1195}
1196
1197static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1198 int wait)
1199{
1200 ext2_clear_super_error(sb);
1201 spin_lock(&EXT2_SB(sb)->s_lock);
1202 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1203 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1204 es->s_wtime = cpu_to_le32(get_seconds());
1205 /* unlock before we do IO */
1206 spin_unlock(&EXT2_SB(sb)->s_lock);
1207 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1208 if (wait)
1209 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1210}
1211
1212/*
1213 * In the second extended file system, it is not necessary to
1214 * write the super block since we use a mapping of the
1215 * disk super block in a buffer.
1216 *
1217 * However, this function is still used to set the fs valid
1218 * flags to 0. We need to set this flag to 0 since the fs
1219 * may have been checked while mounted and e2fsck may have
1220 * set s_state to EXT2_VALID_FS after some corrections.
1221 */
1222static int ext2_sync_fs(struct super_block *sb, int wait)
1223{
1224 struct ext2_sb_info *sbi = EXT2_SB(sb);
1225 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1226
1227 /*
1228 * Write quota structures to quota file, sync_blockdev() will write
1229 * them to disk later
1230 */
1231 dquot_writeback_dquots(sb, -1);
1232
1233 spin_lock(&sbi->s_lock);
1234 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1235 ext2_debug("setting valid to 0\n");
1236 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1237 }
1238 spin_unlock(&sbi->s_lock);
1239 ext2_sync_super(sb, es, wait);
1240 return 0;
1241}
1242
1243static int ext2_freeze(struct super_block *sb)
1244{
1245 struct ext2_sb_info *sbi = EXT2_SB(sb);
1246
1247 /*
1248 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1249 * because we have unattached inodes and thus filesystem is not fully
1250 * consistent.
1251 */
1252 if (atomic_long_read(&sb->s_remove_count)) {
1253 ext2_sync_fs(sb, 1);
1254 return 0;
1255 }
1256 /* Set EXT2_FS_VALID flag */
1257 spin_lock(&sbi->s_lock);
1258 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1259 spin_unlock(&sbi->s_lock);
1260 ext2_sync_super(sb, sbi->s_es, 1);
1261
1262 return 0;
1263}
1264
1265static int ext2_unfreeze(struct super_block *sb)
1266{
1267 /* Just write sb to clear EXT2_VALID_FS flag */
1268 ext2_write_super(sb);
1269
1270 return 0;
1271}
1272
1273void ext2_write_super(struct super_block *sb)
1274{
1275 if (!(sb->s_flags & MS_RDONLY))
1276 ext2_sync_fs(sb, 1);
1277}
1278
1279static int ext2_remount (struct super_block * sb, int * flags, char * data)
1280{
1281 struct ext2_sb_info * sbi = EXT2_SB(sb);
1282 struct ext2_super_block * es;
1283 struct ext2_mount_options old_opts;
1284 unsigned long old_sb_flags;
1285 int err;
1286
1287 sync_filesystem(sb);
1288 spin_lock(&sbi->s_lock);
1289
1290 /* Store the old options */
1291 old_sb_flags = sb->s_flags;
1292 old_opts.s_mount_opt = sbi->s_mount_opt;
1293 old_opts.s_resuid = sbi->s_resuid;
1294 old_opts.s_resgid = sbi->s_resgid;
1295
1296 /*
1297 * Allow the "check" option to be passed as a remount option.
1298 */
1299 if (!parse_options(data, sb)) {
1300 err = -EINVAL;
1301 goto restore_opts;
1302 }
1303
1304 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1305 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1306
1307 es = sbi->s_es;
1308 if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1309 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1310 "dax flag with busy inodes while remounting");
1311 sbi->s_mount_opt ^= EXT2_MOUNT_DAX;
1312 }
1313 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1314 spin_unlock(&sbi->s_lock);
1315 return 0;
1316 }
1317 if (*flags & MS_RDONLY) {
1318 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1319 !(sbi->s_mount_state & EXT2_VALID_FS)) {
1320 spin_unlock(&sbi->s_lock);
1321 return 0;
1322 }
1323
1324 /*
1325 * OK, we are remounting a valid rw partition rdonly, so set
1326 * the rdonly flag and then mark the partition as valid again.
1327 */
1328 es->s_state = cpu_to_le16(sbi->s_mount_state);
1329 es->s_mtime = cpu_to_le32(get_seconds());
1330 spin_unlock(&sbi->s_lock);
1331
1332 err = dquot_suspend(sb, -1);
1333 if (err < 0) {
1334 spin_lock(&sbi->s_lock);
1335 goto restore_opts;
1336 }
1337
1338 ext2_sync_super(sb, es, 1);
1339 } else {
1340 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1341 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1342 if (ret) {
1343 ext2_msg(sb, KERN_WARNING,
1344 "warning: couldn't remount RDWR because of "
1345 "unsupported optional features (%x).",
1346 le32_to_cpu(ret));
1347 err = -EROFS;
1348 goto restore_opts;
1349 }
1350 /*
1351 * Mounting a RDONLY partition read-write, so reread and
1352 * store the current valid flag. (It may have been changed
1353 * by e2fsck since we originally mounted the partition.)
1354 */
1355 sbi->s_mount_state = le16_to_cpu(es->s_state);
1356 if (!ext2_setup_super (sb, es, 0))
1357 sb->s_flags &= ~MS_RDONLY;
1358 spin_unlock(&sbi->s_lock);
1359
1360 ext2_write_super(sb);
1361
1362 dquot_resume(sb, -1);
1363 }
1364
1365 return 0;
1366restore_opts:
1367 sbi->s_mount_opt = old_opts.s_mount_opt;
1368 sbi->s_resuid = old_opts.s_resuid;
1369 sbi->s_resgid = old_opts.s_resgid;
1370 sb->s_flags = old_sb_flags;
1371 spin_unlock(&sbi->s_lock);
1372 return err;
1373}
1374
1375static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1376{
1377 struct super_block *sb = dentry->d_sb;
1378 struct ext2_sb_info *sbi = EXT2_SB(sb);
1379 struct ext2_super_block *es = sbi->s_es;
1380 u64 fsid;
1381
1382 spin_lock(&sbi->s_lock);
1383
1384 if (test_opt (sb, MINIX_DF))
1385 sbi->s_overhead_last = 0;
1386 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1387 unsigned long i, overhead = 0;
1388 smp_rmb();
1389
1390 /*
1391 * Compute the overhead (FS structures). This is constant
1392 * for a given filesystem unless the number of block groups
1393 * changes so we cache the previous value until it does.
1394 */
1395
1396 /*
1397 * All of the blocks before first_data_block are
1398 * overhead
1399 */
1400 overhead = le32_to_cpu(es->s_first_data_block);
1401
1402 /*
1403 * Add the overhead attributed to the superblock and
1404 * block group descriptors. If the sparse superblocks
1405 * feature is turned on, then not all groups have this.
1406 */
1407 for (i = 0; i < sbi->s_groups_count; i++)
1408 overhead += ext2_bg_has_super(sb, i) +
1409 ext2_bg_num_gdb(sb, i);
1410
1411 /*
1412 * Every block group has an inode bitmap, a block
1413 * bitmap, and an inode table.
1414 */
1415 overhead += (sbi->s_groups_count *
1416 (2 + sbi->s_itb_per_group));
1417 sbi->s_overhead_last = overhead;
1418 smp_wmb();
1419 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1420 }
1421
1422 buf->f_type = EXT2_SUPER_MAGIC;
1423 buf->f_bsize = sb->s_blocksize;
1424 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1425 buf->f_bfree = ext2_count_free_blocks(sb);
1426 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1427 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1428 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1429 buf->f_bavail = 0;
1430 buf->f_files = le32_to_cpu(es->s_inodes_count);
1431 buf->f_ffree = ext2_count_free_inodes(sb);
1432 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1433 buf->f_namelen = EXT2_NAME_LEN;
1434 fsid = le64_to_cpup((void *)es->s_uuid) ^
1435 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1436 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1437 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1438 spin_unlock(&sbi->s_lock);
1439 return 0;
1440}
1441
1442static struct dentry *ext2_mount(struct file_system_type *fs_type,
1443 int flags, const char *dev_name, void *data)
1444{
1445 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1446}
1447
1448#ifdef CONFIG_QUOTA
1449
1450/* Read data from quotafile - avoid pagecache and such because we cannot afford
1451 * acquiring the locks... As quota files are never truncated and quota code
1452 * itself serializes the operations (and no one else should touch the files)
1453 * we don't have to be afraid of races */
1454static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1455 size_t len, loff_t off)
1456{
1457 struct inode *inode = sb_dqopt(sb)->files[type];
1458 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1459 int err = 0;
1460 int offset = off & (sb->s_blocksize - 1);
1461 int tocopy;
1462 size_t toread;
1463 struct buffer_head tmp_bh;
1464 struct buffer_head *bh;
1465 loff_t i_size = i_size_read(inode);
1466
1467 if (off > i_size)
1468 return 0;
1469 if (off+len > i_size)
1470 len = i_size-off;
1471 toread = len;
1472 while (toread > 0) {
1473 tocopy = sb->s_blocksize - offset < toread ?
1474 sb->s_blocksize - offset : toread;
1475
1476 tmp_bh.b_state = 0;
1477 tmp_bh.b_size = sb->s_blocksize;
1478 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1479 if (err < 0)
1480 return err;
1481 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1482 memset(data, 0, tocopy);
1483 else {
1484 bh = sb_bread(sb, tmp_bh.b_blocknr);
1485 if (!bh)
1486 return -EIO;
1487 memcpy(data, bh->b_data+offset, tocopy);
1488 brelse(bh);
1489 }
1490 offset = 0;
1491 toread -= tocopy;
1492 data += tocopy;
1493 blk++;
1494 }
1495 return len;
1496}
1497
1498/* Write to quotafile */
1499static ssize_t ext2_quota_write(struct super_block *sb, int type,
1500 const char *data, size_t len, loff_t off)
1501{
1502 struct inode *inode = sb_dqopt(sb)->files[type];
1503 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1504 int err = 0;
1505 int offset = off & (sb->s_blocksize - 1);
1506 int tocopy;
1507 size_t towrite = len;
1508 struct buffer_head tmp_bh;
1509 struct buffer_head *bh;
1510
1511 while (towrite > 0) {
1512 tocopy = sb->s_blocksize - offset < towrite ?
1513 sb->s_blocksize - offset : towrite;
1514
1515 tmp_bh.b_state = 0;
1516 tmp_bh.b_size = sb->s_blocksize;
1517 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1518 if (err < 0)
1519 goto out;
1520 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1521 bh = sb_bread(sb, tmp_bh.b_blocknr);
1522 else
1523 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1524 if (unlikely(!bh)) {
1525 err = -EIO;
1526 goto out;
1527 }
1528 lock_buffer(bh);
1529 memcpy(bh->b_data+offset, data, tocopy);
1530 flush_dcache_page(bh->b_page);
1531 set_buffer_uptodate(bh);
1532 mark_buffer_dirty(bh);
1533 unlock_buffer(bh);
1534 brelse(bh);
1535 offset = 0;
1536 towrite -= tocopy;
1537 data += tocopy;
1538 blk++;
1539 }
1540out:
1541 if (len == towrite)
1542 return err;
1543 if (inode->i_size < off+len-towrite)
1544 i_size_write(inode, off+len-towrite);
1545 inode->i_version++;
1546 inode->i_mtime = inode->i_ctime = current_time(inode);
1547 mark_inode_dirty(inode);
1548 return len - towrite;
1549}
1550
1551#endif
1552
1553static struct file_system_type ext2_fs_type = {
1554 .owner = THIS_MODULE,
1555 .name = "ext2",
1556 .mount = ext2_mount,
1557 .kill_sb = kill_block_super,
1558 .fs_flags = FS_REQUIRES_DEV,
1559};
1560MODULE_ALIAS_FS("ext2");
1561
1562static int __init init_ext2_fs(void)
1563{
1564 int err;
1565
1566 err = init_inodecache();
1567 if (err)
1568 return err;
1569 err = register_filesystem(&ext2_fs_type);
1570 if (err)
1571 goto out;
1572 return 0;
1573out:
1574 destroy_inodecache();
1575 return err;
1576}
1577
1578static void __exit exit_ext2_fs(void)
1579{
1580 unregister_filesystem(&ext2_fs_type);
1581 destroy_inodecache();
1582}
1583
1584MODULE_AUTHOR("Remy Card and others");
1585MODULE_DESCRIPTION("Second Extended Filesystem");
1586MODULE_LICENSE("GPL");
1587module_init(init_ext2_fs)
1588module_exit(exit_ext2_fs)