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(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(lock: &sbi->s_lock);
62 ext2_sync_super(sb, es, wait: 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(fmt: "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 fmt: "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(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(lock: &sbi->s_lock);
159 es->s_state = cpu_to_le16(sbi->s_mount_state);
160 spin_unlock(lock: &sbi->s_lock);
161 ext2_sync_super(sb, es, wait: 1);
162 }
163 db_count = sbi->s_gdb_count;
164 for (i = 0; i < db_count; i++)
165 brelse(bh: sbi->s_group_desc[i]);
166 kvfree(addr: sbi->s_group_desc);
167 kfree(objp: sbi->s_debts);
168 percpu_counter_destroy(fbc: &sbi->s_freeblocks_counter);
169 percpu_counter_destroy(fbc: &sbi->s_freeinodes_counter);
170 percpu_counter_destroy(fbc: &sbi->s_dirs_counter);
171 brelse (bh: sbi->s_sbh);
172 sb->s_fs_info = NULL;
173 kfree(objp: sbi->s_blockgroup_lock);
174 fs_put_dax(dax_dev: sbi->s_daxdev, NULL);
175 kfree(objp: 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 = alloc_inode_sb(sb, cache: ext2_inode_cachep, GFP_KERNEL);
184 if (!ei)
185 return NULL;
186 ei->i_block_alloc_info = NULL;
187 inode_set_iversion(inode: &ei->vfs_inode, val: 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(s: ext2_inode_cachep, objp: 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 inode_init_once(&ei->vfs_inode);
210}
211
212static int __init init_inodecache(void)
213{
214 ext2_inode_cachep = kmem_cache_create_usercopy(name: "ext2_inode_cache",
215 size: sizeof(struct ext2_inode_info), align: 0,
216 flags: (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
217 SLAB_ACCOUNT),
218 offsetof(struct ext2_inode_info, i_data),
219 sizeof_field(struct ext2_inode_info, i_data),
220 ctor: init_once);
221 if (ext2_inode_cachep == NULL)
222 return -ENOMEM;
223 return 0;
224}
225
226static void destroy_inodecache(void)
227{
228 /*
229 * Make sure all delayed rcu free inodes are flushed before we
230 * destroy cache.
231 */
232 rcu_barrier();
233 kmem_cache_destroy(s: ext2_inode_cachep);
234}
235
236static int ext2_show_options(struct seq_file *seq, struct dentry *root)
237{
238 struct super_block *sb = root->d_sb;
239 struct ext2_sb_info *sbi = EXT2_SB(sb);
240 struct ext2_super_block *es = sbi->s_es;
241 unsigned long def_mount_opts;
242
243 spin_lock(lock: &sbi->s_lock);
244 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
245
246 if (sbi->s_sb_block != 1)
247 seq_printf(m: seq, fmt: ",sb=%lu", sbi->s_sb_block);
248 if (test_opt(sb, MINIX_DF))
249 seq_puts(m: seq, s: ",minixdf");
250 if (test_opt(sb, GRPID))
251 seq_puts(m: seq, s: ",grpid");
252 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
253 seq_puts(m: seq, s: ",nogrpid");
254 if (!uid_eq(left: sbi->s_resuid, right: make_kuid(from: &init_user_ns, EXT2_DEF_RESUID)) ||
255 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
256 seq_printf(m: seq, fmt: ",resuid=%u",
257 from_kuid_munged(to: &init_user_ns, uid: sbi->s_resuid));
258 }
259 if (!gid_eq(left: sbi->s_resgid, right: make_kgid(from: &init_user_ns, EXT2_DEF_RESGID)) ||
260 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
261 seq_printf(m: seq, fmt: ",resgid=%u",
262 from_kgid_munged(to: &init_user_ns, gid: sbi->s_resgid));
263 }
264 if (test_opt(sb, ERRORS_RO)) {
265 int def_errors = le16_to_cpu(es->s_errors);
266
267 if (def_errors == EXT2_ERRORS_PANIC ||
268 def_errors == EXT2_ERRORS_CONTINUE) {
269 seq_puts(m: seq, s: ",errors=remount-ro");
270 }
271 }
272 if (test_opt(sb, ERRORS_CONT))
273 seq_puts(m: seq, s: ",errors=continue");
274 if (test_opt(sb, ERRORS_PANIC))
275 seq_puts(m: seq, s: ",errors=panic");
276 if (test_opt(sb, NO_UID32))
277 seq_puts(m: seq, s: ",nouid32");
278 if (test_opt(sb, DEBUG))
279 seq_puts(m: seq, s: ",debug");
280 if (test_opt(sb, OLDALLOC))
281 seq_puts(m: seq, s: ",oldalloc");
282
283#ifdef CONFIG_EXT2_FS_XATTR
284 if (test_opt(sb, XATTR_USER))
285 seq_puts(m: seq, s: ",user_xattr");
286 if (!test_opt(sb, XATTR_USER) &&
287 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
288 seq_puts(m: seq, s: ",nouser_xattr");
289 }
290#endif
291
292#ifdef CONFIG_EXT2_FS_POSIX_ACL
293 if (test_opt(sb, POSIX_ACL))
294 seq_puts(m: seq, s: ",acl");
295 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
296 seq_puts(m: seq, s: ",noacl");
297#endif
298
299 if (test_opt(sb, USRQUOTA))
300 seq_puts(m: seq, s: ",usrquota");
301
302 if (test_opt(sb, GRPQUOTA))
303 seq_puts(m: seq, s: ",grpquota");
304
305 if (test_opt(sb, XIP))
306 seq_puts(m: seq, s: ",xip");
307
308 if (test_opt(sb, DAX))
309 seq_puts(m: seq, s: ",dax");
310
311 if (!test_opt(sb, RESERVATION))
312 seq_puts(m: seq, s: ",noreservation");
313
314 spin_unlock(lock: &sbi->s_lock);
315 return 0;
316}
317
318#ifdef CONFIG_QUOTA
319static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
320static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
321static int ext2_quota_on(struct super_block *sb, int type, int format_id,
322 const struct path *path);
323static struct dquot **ext2_get_dquots(struct inode *inode)
324{
325 return EXT2_I(inode)->i_dquot;
326}
327
328static const struct quotactl_ops ext2_quotactl_ops = {
329 .quota_on = ext2_quota_on,
330 .quota_off = ext2_quota_off,
331 .quota_sync = dquot_quota_sync,
332 .get_state = dquot_get_state,
333 .set_info = dquot_set_dqinfo,
334 .get_dqblk = dquot_get_dqblk,
335 .set_dqblk = dquot_set_dqblk,
336 .get_nextdqblk = dquot_get_next_dqblk,
337};
338#endif
339
340static const struct super_operations ext2_sops = {
341 .alloc_inode = ext2_alloc_inode,
342 .free_inode = ext2_free_in_core_inode,
343 .write_inode = ext2_write_inode,
344 .evict_inode = ext2_evict_inode,
345 .put_super = ext2_put_super,
346 .sync_fs = ext2_sync_fs,
347 .freeze_fs = ext2_freeze,
348 .unfreeze_fs = ext2_unfreeze,
349 .statfs = ext2_statfs,
350 .remount_fs = ext2_remount,
351 .show_options = ext2_show_options,
352#ifdef CONFIG_QUOTA
353 .quota_read = ext2_quota_read,
354 .quota_write = ext2_quota_write,
355 .get_dquots = ext2_get_dquots,
356#endif
357};
358
359static struct inode *ext2_nfs_get_inode(struct super_block *sb,
360 u64 ino, u32 generation)
361{
362 struct inode *inode;
363
364 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
365 return ERR_PTR(error: -ESTALE);
366 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
367 return ERR_PTR(error: -ESTALE);
368
369 /*
370 * ext2_iget isn't quite right if the inode is currently unallocated!
371 * However ext2_iget currently does appropriate checks to handle stale
372 * inodes so everything is OK.
373 */
374 inode = ext2_iget(sb, ino);
375 if (IS_ERR(ptr: inode))
376 return ERR_CAST(ptr: inode);
377 if (generation && inode->i_generation != generation) {
378 /* we didn't find the right inode.. */
379 iput(inode);
380 return ERR_PTR(error: -ESTALE);
381 }
382 return inode;
383}
384
385static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
386 int fh_len, int fh_type)
387{
388 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
389 get_inode: ext2_nfs_get_inode);
390}
391
392static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
393 int fh_len, int fh_type)
394{
395 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
396 get_inode: ext2_nfs_get_inode);
397}
398
399static const struct export_operations ext2_export_ops = {
400 .encode_fh = generic_encode_ino32_fh,
401 .fh_to_dentry = ext2_fh_to_dentry,
402 .fh_to_parent = ext2_fh_to_parent,
403 .get_parent = ext2_get_parent,
404};
405
406static unsigned long get_sb_block(void **data)
407{
408 unsigned long sb_block;
409 char *options = (char *) *data;
410
411 if (!options || strncmp(options, "sb=", 3) != 0)
412 return 1; /* Default location */
413 options += 3;
414 sb_block = simple_strtoul(options, &options, 0);
415 if (*options && *options != ',') {
416 printk("EXT2-fs: Invalid sb specification: %s\n",
417 (char *) *data);
418 return 1;
419 }
420 if (*options == ',')
421 options++;
422 *data = (void *) options;
423 return sb_block;
424}
425
426enum {
427 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
428 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
429 Opt_err_ro, Opt_nouid32, Opt_debug,
430 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
431 Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
432 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
433};
434
435static const match_table_t tokens = {
436 {Opt_bsd_df, "bsddf"},
437 {Opt_minix_df, "minixdf"},
438 {Opt_grpid, "grpid"},
439 {Opt_grpid, "bsdgroups"},
440 {Opt_nogrpid, "nogrpid"},
441 {Opt_nogrpid, "sysvgroups"},
442 {Opt_resgid, "resgid=%u"},
443 {Opt_resuid, "resuid=%u"},
444 {Opt_sb, "sb=%u"},
445 {Opt_err_cont, "errors=continue"},
446 {Opt_err_panic, "errors=panic"},
447 {Opt_err_ro, "errors=remount-ro"},
448 {Opt_nouid32, "nouid32"},
449 {Opt_debug, "debug"},
450 {Opt_oldalloc, "oldalloc"},
451 {Opt_orlov, "orlov"},
452 {Opt_nobh, "nobh"},
453 {Opt_user_xattr, "user_xattr"},
454 {Opt_nouser_xattr, "nouser_xattr"},
455 {Opt_acl, "acl"},
456 {Opt_noacl, "noacl"},
457 {Opt_xip, "xip"},
458 {Opt_dax, "dax"},
459 {Opt_grpquota, "grpquota"},
460 {Opt_ignore, "noquota"},
461 {Opt_quota, "quota"},
462 {Opt_usrquota, "usrquota"},
463 {Opt_reservation, "reservation"},
464 {Opt_noreservation, "noreservation"},
465 {Opt_err, NULL}
466};
467
468static int parse_options(char *options, struct super_block *sb,
469 struct ext2_mount_options *opts)
470{
471 char *p;
472 substring_t args[MAX_OPT_ARGS];
473 int option;
474 kuid_t uid;
475 kgid_t gid;
476
477 if (!options)
478 return 1;
479
480 while ((p = strsep (&options, ",")) != NULL) {
481 int token;
482 if (!*p)
483 continue;
484
485 token = match_token(p, table: tokens, args);
486 switch (token) {
487 case Opt_bsd_df:
488 clear_opt (opts->s_mount_opt, MINIX_DF);
489 break;
490 case Opt_minix_df:
491 set_opt (opts->s_mount_opt, MINIX_DF);
492 break;
493 case Opt_grpid:
494 set_opt (opts->s_mount_opt, GRPID);
495 break;
496 case Opt_nogrpid:
497 clear_opt (opts->s_mount_opt, GRPID);
498 break;
499 case Opt_resuid:
500 if (match_int(&args[0], result: &option))
501 return 0;
502 uid = make_kuid(current_user_ns(), uid: option);
503 if (!uid_valid(uid)) {
504 ext2_msg(sb, KERN_ERR, fmt: "Invalid uid value %d", option);
505 return 0;
506
507 }
508 opts->s_resuid = uid;
509 break;
510 case Opt_resgid:
511 if (match_int(&args[0], result: &option))
512 return 0;
513 gid = make_kgid(current_user_ns(), gid: option);
514 if (!gid_valid(gid)) {
515 ext2_msg(sb, KERN_ERR, fmt: "Invalid gid value %d", option);
516 return 0;
517 }
518 opts->s_resgid = gid;
519 break;
520 case Opt_sb:
521 /* handled by get_sb_block() instead of here */
522 /* *sb_block = match_int(&args[0]); */
523 break;
524 case Opt_err_panic:
525 clear_opt (opts->s_mount_opt, ERRORS_CONT);
526 clear_opt (opts->s_mount_opt, ERRORS_RO);
527 set_opt (opts->s_mount_opt, ERRORS_PANIC);
528 break;
529 case Opt_err_ro:
530 clear_opt (opts->s_mount_opt, ERRORS_CONT);
531 clear_opt (opts->s_mount_opt, ERRORS_PANIC);
532 set_opt (opts->s_mount_opt, ERRORS_RO);
533 break;
534 case Opt_err_cont:
535 clear_opt (opts->s_mount_opt, ERRORS_RO);
536 clear_opt (opts->s_mount_opt, ERRORS_PANIC);
537 set_opt (opts->s_mount_opt, ERRORS_CONT);
538 break;
539 case Opt_nouid32:
540 set_opt (opts->s_mount_opt, NO_UID32);
541 break;
542 case Opt_debug:
543 set_opt (opts->s_mount_opt, DEBUG);
544 break;
545 case Opt_oldalloc:
546 set_opt (opts->s_mount_opt, OLDALLOC);
547 break;
548 case Opt_orlov:
549 clear_opt (opts->s_mount_opt, OLDALLOC);
550 break;
551 case Opt_nobh:
552 ext2_msg(sb, KERN_INFO,
553 fmt: "nobh option not supported");
554 break;
555#ifdef CONFIG_EXT2_FS_XATTR
556 case Opt_user_xattr:
557 set_opt (opts->s_mount_opt, XATTR_USER);
558 break;
559 case Opt_nouser_xattr:
560 clear_opt (opts->s_mount_opt, XATTR_USER);
561 break;
562#else
563 case Opt_user_xattr:
564 case Opt_nouser_xattr:
565 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
566 "not supported");
567 break;
568#endif
569#ifdef CONFIG_EXT2_FS_POSIX_ACL
570 case Opt_acl:
571 set_opt(opts->s_mount_opt, POSIX_ACL);
572 break;
573 case Opt_noacl:
574 clear_opt(opts->s_mount_opt, POSIX_ACL);
575 break;
576#else
577 case Opt_acl:
578 case Opt_noacl:
579 ext2_msg(sb, KERN_INFO,
580 "(no)acl options not supported");
581 break;
582#endif
583 case Opt_xip:
584 ext2_msg(sb, KERN_INFO, fmt: "use dax instead of xip");
585 set_opt(opts->s_mount_opt, XIP);
586 fallthrough;
587 case Opt_dax:
588#ifdef CONFIG_FS_DAX
589 ext2_msg(sb, KERN_WARNING,
590 fmt: "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
591 set_opt(opts->s_mount_opt, DAX);
592#else
593 ext2_msg(sb, KERN_INFO, "dax option not supported");
594#endif
595 break;
596
597#if defined(CONFIG_QUOTA)
598 case Opt_quota:
599 case Opt_usrquota:
600 set_opt(opts->s_mount_opt, USRQUOTA);
601 break;
602
603 case Opt_grpquota:
604 set_opt(opts->s_mount_opt, GRPQUOTA);
605 break;
606#else
607 case Opt_quota:
608 case Opt_usrquota:
609 case Opt_grpquota:
610 ext2_msg(sb, KERN_INFO,
611 "quota operations not supported");
612 break;
613#endif
614
615 case Opt_reservation:
616 set_opt(opts->s_mount_opt, RESERVATION);
617 ext2_msg(sb, KERN_INFO, fmt: "reservations ON");
618 break;
619 case Opt_noreservation:
620 clear_opt(opts->s_mount_opt, RESERVATION);
621 ext2_msg(sb, KERN_INFO, fmt: "reservations OFF");
622 break;
623 case Opt_ignore:
624 break;
625 default:
626 return 0;
627 }
628 }
629 return 1;
630}
631
632static int ext2_setup_super (struct super_block * sb,
633 struct ext2_super_block * es,
634 int read_only)
635{
636 int res = 0;
637 struct ext2_sb_info *sbi = EXT2_SB(sb);
638
639 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
640 ext2_msg(sb, KERN_ERR,
641 fmt: "error: revision level too high, "
642 "forcing read-only mode");
643 res = SB_RDONLY;
644 }
645 if (read_only)
646 return res;
647 if (!(sbi->s_mount_state & EXT2_VALID_FS))
648 ext2_msg(sb, KERN_WARNING,
649 fmt: "warning: mounting unchecked fs, "
650 "running e2fsck is recommended");
651 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
652 ext2_msg(sb, KERN_WARNING,
653 fmt: "warning: mounting fs with errors, "
654 "running e2fsck is recommended");
655 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
656 le16_to_cpu(es->s_mnt_count) >=
657 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
658 ext2_msg(sb, KERN_WARNING,
659 fmt: "warning: maximal mount count reached, "
660 "running e2fsck is recommended");
661 else if (le32_to_cpu(es->s_checkinterval) &&
662 (le32_to_cpu(es->s_lastcheck) +
663 le32_to_cpu(es->s_checkinterval) <=
664 ktime_get_real_seconds()))
665 ext2_msg(sb, KERN_WARNING,
666 fmt: "warning: checktime reached, "
667 "running e2fsck is recommended");
668 if (!le16_to_cpu(es->s_max_mnt_count))
669 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
670 le16_add_cpu(var: &es->s_mnt_count, val: 1);
671 if (test_opt (sb, DEBUG))
672 ext2_msg(sb, KERN_INFO, fmt: "%s, %s, bs=%lu, gc=%lu, "
673 "bpg=%lu, ipg=%lu, mo=%04lx]",
674 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
675 sbi->s_groups_count,
676 EXT2_BLOCKS_PER_GROUP(sb),
677 EXT2_INODES_PER_GROUP(sb),
678 sbi->s_mount_opt);
679 return res;
680}
681
682static int ext2_check_descriptors(struct super_block *sb)
683{
684 int i;
685 struct ext2_sb_info *sbi = EXT2_SB(sb);
686
687 ext2_debug ("Checking group descriptors");
688
689 for (i = 0; i < sbi->s_groups_count; i++) {
690 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, block_group: i, NULL);
691 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, group_no: i);
692 ext2_fsblk_t last_block = ext2_group_last_block_no(sb, group_no: i);
693
694 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
695 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
696 {
697 ext2_error (sb, function: "ext2_check_descriptors",
698 fmt: "Block bitmap for group %d"
699 " not in group (block %lu)!",
700 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
701 return 0;
702 }
703 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
704 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
705 {
706 ext2_error (sb, function: "ext2_check_descriptors",
707 fmt: "Inode bitmap for group %d"
708 " not in group (block %lu)!",
709 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
710 return 0;
711 }
712 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
713 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
714 last_block)
715 {
716 ext2_error (sb, function: "ext2_check_descriptors",
717 fmt: "Inode table for group %d"
718 " not in group (block %lu)!",
719 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
720 return 0;
721 }
722 }
723 return 1;
724}
725
726/*
727 * Maximal file size. There is a direct, and {,double-,triple-}indirect
728 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
729 * We need to be 1 filesystem block less than the 2^32 sector limit.
730 */
731static loff_t ext2_max_size(int bits)
732{
733 loff_t res = EXT2_NDIR_BLOCKS;
734 int meta_blocks;
735 unsigned int upper_limit;
736 unsigned int ppb = 1 << (bits-2);
737
738 /* This is calculated to be the largest file size for a
739 * dense, file such that the total number of
740 * sectors in the file, including data and all indirect blocks,
741 * does not exceed 2^32 -1
742 * __u32 i_blocks representing the total number of
743 * 512 bytes blocks of the file
744 */
745 upper_limit = (1LL << 32) - 1;
746
747 /* total blocks in file system block size */
748 upper_limit >>= (bits - 9);
749
750 /* Compute how many blocks we can address by block tree */
751 res += 1LL << (bits-2);
752 res += 1LL << (2*(bits-2));
753 res += 1LL << (3*(bits-2));
754 /* Compute how many metadata blocks are needed */
755 meta_blocks = 1;
756 meta_blocks += 1 + ppb;
757 meta_blocks += 1 + ppb + ppb * ppb;
758 /* Does block tree limit file size? */
759 if (res + meta_blocks <= upper_limit)
760 goto check_lfs;
761
762 res = upper_limit;
763 /* How many metadata blocks are needed for addressing upper_limit? */
764 upper_limit -= EXT2_NDIR_BLOCKS;
765 /* indirect blocks */
766 meta_blocks = 1;
767 upper_limit -= ppb;
768 /* double indirect blocks */
769 if (upper_limit < ppb * ppb) {
770 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
771 res -= meta_blocks;
772 goto check_lfs;
773 }
774 meta_blocks += 1 + ppb;
775 upper_limit -= ppb * ppb;
776 /* tripple indirect blocks for the rest */
777 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
778 DIV_ROUND_UP(upper_limit, ppb*ppb);
779 res -= meta_blocks;
780check_lfs:
781 res <<= bits;
782 if (res > MAX_LFS_FILESIZE)
783 res = MAX_LFS_FILESIZE;
784
785 return res;
786}
787
788static unsigned long descriptor_loc(struct super_block *sb,
789 unsigned long logic_sb_block,
790 int nr)
791{
792 struct ext2_sb_info *sbi = EXT2_SB(sb);
793 unsigned long bg, first_meta_bg;
794
795 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
796
797 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
798 nr < first_meta_bg)
799 return (logic_sb_block + nr + 1);
800 bg = sbi->s_desc_per_block * nr;
801
802 return ext2_group_first_block_no(sb, group_no: bg) + ext2_bg_has_super(sb, group: bg);
803}
804
805static int ext2_fill_super(struct super_block *sb, void *data, int silent)
806{
807 struct buffer_head * bh;
808 struct ext2_sb_info * sbi;
809 struct ext2_super_block * es;
810 struct inode *root;
811 unsigned long block;
812 unsigned long sb_block = get_sb_block(data: &data);
813 unsigned long logic_sb_block;
814 unsigned long offset = 0;
815 unsigned long def_mount_opts;
816 long ret = -ENOMEM;
817 int blocksize = BLOCK_SIZE;
818 int db_count;
819 int i, j;
820 __le32 features;
821 int err;
822 struct ext2_mount_options opts;
823
824 sbi = kzalloc(size: sizeof(*sbi), GFP_KERNEL);
825 if (!sbi)
826 return -ENOMEM;
827
828 sbi->s_blockgroup_lock =
829 kzalloc(size: sizeof(struct blockgroup_lock), GFP_KERNEL);
830 if (!sbi->s_blockgroup_lock) {
831 kfree(objp: sbi);
832 return -ENOMEM;
833 }
834 sb->s_fs_info = sbi;
835 sbi->s_sb_block = sb_block;
836 sbi->s_daxdev = fs_dax_get_by_bdev(bdev: sb->s_bdev, start_off: &sbi->s_dax_part_off,
837 NULL, NULL);
838
839 spin_lock_init(&sbi->s_lock);
840 ret = -EINVAL;
841
842 /*
843 * See what the current blocksize for the device is, and
844 * use that as the blocksize. Otherwise (or if the blocksize
845 * is smaller than the default) use the default.
846 * This is important for devices that have a hardware
847 * sectorsize that is larger than the default.
848 */
849 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
850 if (!blocksize) {
851 ext2_msg(sb, KERN_ERR, fmt: "error: unable to set blocksize");
852 goto failed_sbi;
853 }
854
855 /*
856 * If the superblock doesn't start on a hardware sector boundary,
857 * calculate the offset.
858 */
859 if (blocksize != BLOCK_SIZE) {
860 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
861 offset = (sb_block*BLOCK_SIZE) % blocksize;
862 } else {
863 logic_sb_block = sb_block;
864 }
865
866 if (!(bh = sb_bread(sb, block: logic_sb_block))) {
867 ext2_msg(sb, KERN_ERR, fmt: "error: unable to read superblock");
868 goto failed_sbi;
869 }
870 /*
871 * Note: s_es must be initialized as soon as possible because
872 * some ext2 macro-instructions depend on its value
873 */
874 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
875 sbi->s_es = es;
876 sb->s_magic = le16_to_cpu(es->s_magic);
877
878 if (sb->s_magic != EXT2_SUPER_MAGIC)
879 goto cantfind_ext2;
880
881 opts.s_mount_opt = 0;
882 /* Set defaults before we parse the mount options */
883 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
884 if (def_mount_opts & EXT2_DEFM_DEBUG)
885 set_opt(opts.s_mount_opt, DEBUG);
886 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
887 set_opt(opts.s_mount_opt, GRPID);
888 if (def_mount_opts & EXT2_DEFM_UID16)
889 set_opt(opts.s_mount_opt, NO_UID32);
890#ifdef CONFIG_EXT2_FS_XATTR
891 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
892 set_opt(opts.s_mount_opt, XATTR_USER);
893#endif
894#ifdef CONFIG_EXT2_FS_POSIX_ACL
895 if (def_mount_opts & EXT2_DEFM_ACL)
896 set_opt(opts.s_mount_opt, POSIX_ACL);
897#endif
898
899 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
900 set_opt(opts.s_mount_opt, ERRORS_PANIC);
901 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
902 set_opt(opts.s_mount_opt, ERRORS_CONT);
903 else
904 set_opt(opts.s_mount_opt, ERRORS_RO);
905
906 opts.s_resuid = make_kuid(from: &init_user_ns, le16_to_cpu(es->s_def_resuid));
907 opts.s_resgid = make_kgid(from: &init_user_ns, le16_to_cpu(es->s_def_resgid));
908
909 set_opt(opts.s_mount_opt, RESERVATION);
910
911 if (!parse_options(options: (char *) data, sb, opts: &opts))
912 goto failed_mount;
913
914 sbi->s_mount_opt = opts.s_mount_opt;
915 sbi->s_resuid = opts.s_resuid;
916 sbi->s_resgid = opts.s_resgid;
917
918 sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
919 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
920 sb->s_iflags |= SB_I_CGROUPWB;
921
922 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
923 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
924 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
925 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
926 ext2_msg(sb, KERN_WARNING,
927 fmt: "warning: feature flags set on rev 0 fs, "
928 "running e2fsck is recommended");
929 /*
930 * Check feature flags regardless of the revision level, since we
931 * previously didn't change the revision level when setting the flags,
932 * so there is a chance incompat flags are set on a rev 0 filesystem.
933 */
934 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
935 if (features) {
936 ext2_msg(sb, KERN_ERR, fmt: "error: couldn't mount because of "
937 "unsupported optional features (%x)",
938 le32_to_cpu(features));
939 goto failed_mount;
940 }
941 if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
942 ext2_msg(sb, KERN_ERR, fmt: "error: couldn't mount RDWR because of "
943 "unsupported optional features (%x)",
944 le32_to_cpu(features));
945 goto failed_mount;
946 }
947
948 if (le32_to_cpu(es->s_log_block_size) >
949 (EXT2_MAX_BLOCK_LOG_SIZE - BLOCK_SIZE_BITS)) {
950 ext2_msg(sb, KERN_ERR,
951 fmt: "Invalid log block size: %u",
952 le32_to_cpu(es->s_log_block_size));
953 goto failed_mount;
954 }
955 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
956
957 if (test_opt(sb, DAX)) {
958 if (!sbi->s_daxdev) {
959 ext2_msg(sb, KERN_ERR,
960 fmt: "DAX unsupported by block device. Turning off DAX.");
961 clear_opt(sbi->s_mount_opt, DAX);
962 } else if (blocksize != PAGE_SIZE) {
963 ext2_msg(sb, KERN_ERR, fmt: "unsupported blocksize for DAX\n");
964 clear_opt(sbi->s_mount_opt, DAX);
965 }
966 }
967
968 /* If the blocksize doesn't match, re-read the thing.. */
969 if (sb->s_blocksize != blocksize) {
970 brelse(bh);
971
972 if (!sb_set_blocksize(sb, blocksize)) {
973 ext2_msg(sb, KERN_ERR,
974 fmt: "error: bad blocksize %d", blocksize);
975 goto failed_sbi;
976 }
977
978 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
979 offset = (sb_block*BLOCK_SIZE) % blocksize;
980 bh = sb_bread(sb, block: logic_sb_block);
981 if(!bh) {
982 ext2_msg(sb, KERN_ERR, fmt: "error: couldn't read"
983 "superblock on 2nd try");
984 goto failed_sbi;
985 }
986 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
987 sbi->s_es = es;
988 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
989 ext2_msg(sb, KERN_ERR, fmt: "error: magic mismatch");
990 goto failed_mount;
991 }
992 }
993
994 sb->s_maxbytes = ext2_max_size(bits: sb->s_blocksize_bits);
995 sb->s_max_links = EXT2_LINK_MAX;
996 sb->s_time_min = S32_MIN;
997 sb->s_time_max = S32_MAX;
998
999 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
1000 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
1001 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
1002 } else {
1003 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1004 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1005 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
1006 !is_power_of_2(n: sbi->s_inode_size) ||
1007 (sbi->s_inode_size > blocksize)) {
1008 ext2_msg(sb, KERN_ERR,
1009 fmt: "error: unsupported inode size: %d",
1010 sbi->s_inode_size);
1011 goto failed_mount;
1012 }
1013 }
1014
1015 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1016 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1017
1018 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1019 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1020 goto cantfind_ext2;
1021 sbi->s_itb_per_group = sbi->s_inodes_per_group /
1022 sbi->s_inodes_per_block;
1023 sbi->s_desc_per_block = sb->s_blocksize /
1024 sizeof (struct ext2_group_desc);
1025 sbi->s_sbh = bh;
1026 sbi->s_mount_state = le16_to_cpu(es->s_state);
1027 sbi->s_addr_per_block_bits =
1028 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1029 sbi->s_desc_per_block_bits =
1030 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1031
1032 if (sb->s_magic != EXT2_SUPER_MAGIC)
1033 goto cantfind_ext2;
1034
1035 if (sb->s_blocksize != bh->b_size) {
1036 if (!silent)
1037 ext2_msg(sb, KERN_ERR, fmt: "error: unsupported blocksize");
1038 goto failed_mount;
1039 }
1040
1041 if (es->s_log_frag_size != es->s_log_block_size) {
1042 ext2_msg(sb, KERN_ERR,
1043 fmt: "error: fragsize log %u != blocksize log %u",
1044 le32_to_cpu(es->s_log_frag_size), sb->s_blocksize_bits);
1045 goto failed_mount;
1046 }
1047
1048 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1049 ext2_msg(sb, KERN_ERR,
1050 fmt: "error: #blocks per group too big: %lu",
1051 sbi->s_blocks_per_group);
1052 goto failed_mount;
1053 }
1054 /* At least inode table, bitmaps, and sb have to fit in one group */
1055 if (sbi->s_blocks_per_group <= sbi->s_itb_per_group + 3) {
1056 ext2_msg(sb, KERN_ERR,
1057 fmt: "error: #blocks per group smaller than metadata size: %lu <= %lu",
1058 sbi->s_blocks_per_group, sbi->s_inodes_per_group + 3);
1059 goto failed_mount;
1060 }
1061 if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
1062 sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1063 ext2_msg(sb, KERN_ERR,
1064 fmt: "error: invalid #inodes per group: %lu",
1065 sbi->s_inodes_per_group);
1066 goto failed_mount;
1067 }
1068 if (sb_bdev_nr_blocks(sb) < le32_to_cpu(es->s_blocks_count)) {
1069 ext2_msg(sb, KERN_ERR,
1070 fmt: "bad geometry: block count %u exceeds size of device (%u blocks)",
1071 le32_to_cpu(es->s_blocks_count),
1072 (unsigned)sb_bdev_nr_blocks(sb));
1073 goto failed_mount;
1074 }
1075
1076 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1077 le32_to_cpu(es->s_first_data_block) - 1)
1078 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1079 if ((u64)sbi->s_groups_count * sbi->s_inodes_per_group !=
1080 le32_to_cpu(es->s_inodes_count)) {
1081 ext2_msg(sb, KERN_ERR, fmt: "error: invalid #inodes: %u vs computed %llu",
1082 le32_to_cpu(es->s_inodes_count),
1083 (u64)sbi->s_groups_count * sbi->s_inodes_per_group);
1084 goto failed_mount;
1085 }
1086 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1087 EXT2_DESC_PER_BLOCK(sb);
1088 sbi->s_group_desc = kvmalloc_array(n: db_count,
1089 size: sizeof(struct buffer_head *),
1090 GFP_KERNEL);
1091 if (sbi->s_group_desc == NULL) {
1092 ret = -ENOMEM;
1093 ext2_msg(sb, KERN_ERR, fmt: "error: not enough memory");
1094 goto failed_mount;
1095 }
1096 bgl_lock_init(bgl: sbi->s_blockgroup_lock);
1097 sbi->s_debts = kcalloc(n: sbi->s_groups_count, size: sizeof(*sbi->s_debts), GFP_KERNEL);
1098 if (!sbi->s_debts) {
1099 ret = -ENOMEM;
1100 ext2_msg(sb, KERN_ERR, fmt: "error: not enough memory");
1101 goto failed_mount_group_desc;
1102 }
1103 for (i = 0; i < db_count; i++) {
1104 block = descriptor_loc(sb, logic_sb_block, nr: i);
1105 sbi->s_group_desc[i] = sb_bread(sb, block);
1106 if (!sbi->s_group_desc[i]) {
1107 for (j = 0; j < i; j++)
1108 brelse (bh: sbi->s_group_desc[j]);
1109 ext2_msg(sb, KERN_ERR,
1110 fmt: "error: unable to read group descriptors");
1111 goto failed_mount_group_desc;
1112 }
1113 }
1114 if (!ext2_check_descriptors (sb)) {
1115 ext2_msg(sb, KERN_ERR, fmt: "group descriptors corrupted");
1116 goto failed_mount2;
1117 }
1118 sbi->s_gdb_count = db_count;
1119 get_random_bytes(buf: &sbi->s_next_generation, len: sizeof(u32));
1120 spin_lock_init(&sbi->s_next_gen_lock);
1121
1122 /* per filesystem reservation list head & lock */
1123 spin_lock_init(&sbi->s_rsv_window_lock);
1124 sbi->s_rsv_window_root = RB_ROOT;
1125 /*
1126 * Add a single, static dummy reservation to the start of the
1127 * reservation window list --- it gives us a placeholder for
1128 * append-at-start-of-list which makes the allocation logic
1129 * _much_ simpler.
1130 */
1131 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1132 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1133 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1134 sbi->s_rsv_window_head.rsv_goal_size = 0;
1135 ext2_rsv_window_add(sb, rsv: &sbi->s_rsv_window_head);
1136
1137 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1138 ext2_count_free_blocks(sb), GFP_KERNEL);
1139 if (!err) {
1140 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1141 ext2_count_free_inodes(sb), GFP_KERNEL);
1142 }
1143 if (!err) {
1144 err = percpu_counter_init(&sbi->s_dirs_counter,
1145 ext2_count_dirs(sb), GFP_KERNEL);
1146 }
1147 if (err) {
1148 ret = err;
1149 ext2_msg(sb, KERN_ERR, fmt: "error: insufficient memory");
1150 goto failed_mount3;
1151 }
1152
1153#ifdef CONFIG_EXT2_FS_XATTR
1154 sbi->s_ea_block_cache = ext2_xattr_create_cache();
1155 if (!sbi->s_ea_block_cache) {
1156 ret = -ENOMEM;
1157 ext2_msg(sb, KERN_ERR, fmt: "Failed to create ea_block_cache");
1158 goto failed_mount3;
1159 }
1160#endif
1161 /*
1162 * set up enough so that it can read an inode
1163 */
1164 sb->s_op = &ext2_sops;
1165 sb->s_export_op = &ext2_export_ops;
1166 sb->s_xattr = ext2_xattr_handlers;
1167
1168#ifdef CONFIG_QUOTA
1169 sb->dq_op = &dquot_operations;
1170 sb->s_qcop = &ext2_quotactl_ops;
1171 sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1172#endif
1173
1174 root = ext2_iget(sb, EXT2_ROOT_INO);
1175 if (IS_ERR(ptr: root)) {
1176 ret = PTR_ERR(ptr: root);
1177 goto failed_mount3;
1178 }
1179 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1180 iput(root);
1181 ext2_msg(sb, KERN_ERR, fmt: "error: corrupt root inode, run e2fsck");
1182 goto failed_mount3;
1183 }
1184
1185 sb->s_root = d_make_root(root);
1186 if (!sb->s_root) {
1187 ext2_msg(sb, KERN_ERR, fmt: "error: get root inode failed");
1188 ret = -ENOMEM;
1189 goto failed_mount3;
1190 }
1191 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1192 ext2_msg(sb, KERN_WARNING,
1193 fmt: "warning: mounting ext3 filesystem as ext2");
1194 if (ext2_setup_super (sb, es, read_only: sb_rdonly(sb)))
1195 sb->s_flags |= SB_RDONLY;
1196 ext2_write_super(sb);
1197 return 0;
1198
1199cantfind_ext2:
1200 if (!silent)
1201 ext2_msg(sb, KERN_ERR,
1202 fmt: "error: can't find an ext2 filesystem on dev %s.",
1203 sb->s_id);
1204 goto failed_mount;
1205failed_mount3:
1206 ext2_xattr_destroy_cache(cache: sbi->s_ea_block_cache);
1207 percpu_counter_destroy(fbc: &sbi->s_freeblocks_counter);
1208 percpu_counter_destroy(fbc: &sbi->s_freeinodes_counter);
1209 percpu_counter_destroy(fbc: &sbi->s_dirs_counter);
1210failed_mount2:
1211 for (i = 0; i < db_count; i++)
1212 brelse(bh: sbi->s_group_desc[i]);
1213failed_mount_group_desc:
1214 kvfree(addr: sbi->s_group_desc);
1215 kfree(objp: sbi->s_debts);
1216failed_mount:
1217 brelse(bh);
1218failed_sbi:
1219 fs_put_dax(dax_dev: sbi->s_daxdev, NULL);
1220 sb->s_fs_info = NULL;
1221 kfree(objp: sbi->s_blockgroup_lock);
1222 kfree(objp: sbi);
1223 return ret;
1224}
1225
1226static void ext2_clear_super_error(struct super_block *sb)
1227{
1228 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1229
1230 if (buffer_write_io_error(bh: sbh)) {
1231 /*
1232 * Oh, dear. A previous attempt to write the
1233 * superblock failed. This could happen because the
1234 * USB device was yanked out. Or it could happen to
1235 * be a transient write error and maybe the block will
1236 * be remapped. Nothing we can do but to retry the
1237 * write and hope for the best.
1238 */
1239 ext2_msg(sb, KERN_ERR,
1240 fmt: "previous I/O error to superblock detected");
1241 clear_buffer_write_io_error(bh: sbh);
1242 set_buffer_uptodate(sbh);
1243 }
1244}
1245
1246void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1247 int wait)
1248{
1249 ext2_clear_super_error(sb);
1250 spin_lock(lock: &EXT2_SB(sb)->s_lock);
1251 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1252 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1253 es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1254 /* unlock before we do IO */
1255 spin_unlock(lock: &EXT2_SB(sb)->s_lock);
1256 mark_buffer_dirty(bh: EXT2_SB(sb)->s_sbh);
1257 if (wait)
1258 sync_dirty_buffer(bh: EXT2_SB(sb)->s_sbh);
1259}
1260
1261/*
1262 * In the second extended file system, it is not necessary to
1263 * write the super block since we use a mapping of the
1264 * disk super block in a buffer.
1265 *
1266 * However, this function is still used to set the fs valid
1267 * flags to 0. We need to set this flag to 0 since the fs
1268 * may have been checked while mounted and e2fsck may have
1269 * set s_state to EXT2_VALID_FS after some corrections.
1270 */
1271static int ext2_sync_fs(struct super_block *sb, int wait)
1272{
1273 struct ext2_sb_info *sbi = EXT2_SB(sb);
1274 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1275
1276 /*
1277 * Write quota structures to quota file, sync_blockdev() will write
1278 * them to disk later
1279 */
1280 dquot_writeback_dquots(sb, type: -1);
1281
1282 spin_lock(lock: &sbi->s_lock);
1283 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1284 ext2_debug("setting valid to 0\n");
1285 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1286 }
1287 spin_unlock(lock: &sbi->s_lock);
1288 ext2_sync_super(sb, es, wait);
1289 return 0;
1290}
1291
1292static int ext2_freeze(struct super_block *sb)
1293{
1294 struct ext2_sb_info *sbi = EXT2_SB(sb);
1295
1296 /*
1297 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1298 * because we have unattached inodes and thus filesystem is not fully
1299 * consistent.
1300 */
1301 if (atomic_long_read(v: &sb->s_remove_count)) {
1302 ext2_sync_fs(sb, wait: 1);
1303 return 0;
1304 }
1305 /* Set EXT2_FS_VALID flag */
1306 spin_lock(lock: &sbi->s_lock);
1307 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1308 spin_unlock(lock: &sbi->s_lock);
1309 ext2_sync_super(sb, es: sbi->s_es, wait: 1);
1310
1311 return 0;
1312}
1313
1314static int ext2_unfreeze(struct super_block *sb)
1315{
1316 /* Just write sb to clear EXT2_VALID_FS flag */
1317 ext2_write_super(sb);
1318
1319 return 0;
1320}
1321
1322static void ext2_write_super(struct super_block *sb)
1323{
1324 if (!sb_rdonly(sb))
1325 ext2_sync_fs(sb, wait: 1);
1326}
1327
1328static int ext2_remount (struct super_block * sb, int * flags, char * data)
1329{
1330 struct ext2_sb_info * sbi = EXT2_SB(sb);
1331 struct ext2_super_block * es;
1332 struct ext2_mount_options new_opts;
1333 int err;
1334
1335 sync_filesystem(sb);
1336
1337 spin_lock(lock: &sbi->s_lock);
1338 new_opts.s_mount_opt = sbi->s_mount_opt;
1339 new_opts.s_resuid = sbi->s_resuid;
1340 new_opts.s_resgid = sbi->s_resgid;
1341 spin_unlock(lock: &sbi->s_lock);
1342
1343 if (!parse_options(options: data, sb, opts: &new_opts))
1344 return -EINVAL;
1345
1346 spin_lock(lock: &sbi->s_lock);
1347 es = sbi->s_es;
1348 if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1349 ext2_msg(sb, KERN_WARNING, fmt: "warning: refusing change of "
1350 "dax flag with busy inodes while remounting");
1351 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1352 }
1353 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1354 goto out_set;
1355 if (*flags & SB_RDONLY) {
1356 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1357 !(sbi->s_mount_state & EXT2_VALID_FS))
1358 goto out_set;
1359
1360 /*
1361 * OK, we are remounting a valid rw partition rdonly, so set
1362 * the rdonly flag and then mark the partition as valid again.
1363 */
1364 es->s_state = cpu_to_le16(sbi->s_mount_state);
1365 es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1366 spin_unlock(lock: &sbi->s_lock);
1367
1368 err = dquot_suspend(sb, type: -1);
1369 if (err < 0)
1370 return err;
1371
1372 ext2_sync_super(sb, es, wait: 1);
1373 } else {
1374 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1375 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1376 if (ret) {
1377 spin_unlock(lock: &sbi->s_lock);
1378 ext2_msg(sb, KERN_WARNING,
1379 fmt: "warning: couldn't remount RDWR because of "
1380 "unsupported optional features (%x).",
1381 le32_to_cpu(ret));
1382 return -EROFS;
1383 }
1384 /*
1385 * Mounting a RDONLY partition read-write, so reread and
1386 * store the current valid flag. (It may have been changed
1387 * by e2fsck since we originally mounted the partition.)
1388 */
1389 sbi->s_mount_state = le16_to_cpu(es->s_state);
1390 if (!ext2_setup_super (sb, es, read_only: 0))
1391 sb->s_flags &= ~SB_RDONLY;
1392 spin_unlock(lock: &sbi->s_lock);
1393
1394 ext2_write_super(sb);
1395
1396 dquot_resume(sb, type: -1);
1397 }
1398
1399 spin_lock(lock: &sbi->s_lock);
1400out_set:
1401 sbi->s_mount_opt = new_opts.s_mount_opt;
1402 sbi->s_resuid = new_opts.s_resuid;
1403 sbi->s_resgid = new_opts.s_resgid;
1404 sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1405 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
1406 spin_unlock(lock: &sbi->s_lock);
1407
1408 return 0;
1409}
1410
1411static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1412{
1413 struct super_block *sb = dentry->d_sb;
1414 struct ext2_sb_info *sbi = EXT2_SB(sb);
1415 struct ext2_super_block *es = sbi->s_es;
1416
1417 spin_lock(lock: &sbi->s_lock);
1418
1419 if (test_opt (sb, MINIX_DF))
1420 sbi->s_overhead_last = 0;
1421 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1422 unsigned long i, overhead = 0;
1423 smp_rmb();
1424
1425 /*
1426 * Compute the overhead (FS structures). This is constant
1427 * for a given filesystem unless the number of block groups
1428 * changes so we cache the previous value until it does.
1429 */
1430
1431 /*
1432 * All of the blocks before first_data_block are
1433 * overhead
1434 */
1435 overhead = le32_to_cpu(es->s_first_data_block);
1436
1437 /*
1438 * Add the overhead attributed to the superblock and
1439 * block group descriptors. If the sparse superblocks
1440 * feature is turned on, then not all groups have this.
1441 */
1442 for (i = 0; i < sbi->s_groups_count; i++)
1443 overhead += ext2_bg_has_super(sb, group: i) +
1444 ext2_bg_num_gdb(sb, group: i);
1445
1446 /*
1447 * Every block group has an inode bitmap, a block
1448 * bitmap, and an inode table.
1449 */
1450 overhead += (sbi->s_groups_count *
1451 (2 + sbi->s_itb_per_group));
1452 sbi->s_overhead_last = overhead;
1453 smp_wmb();
1454 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1455 }
1456
1457 buf->f_type = EXT2_SUPER_MAGIC;
1458 buf->f_bsize = sb->s_blocksize;
1459 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1460 buf->f_bfree = ext2_count_free_blocks(sb);
1461 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1462 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1463 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1464 buf->f_bavail = 0;
1465 buf->f_files = le32_to_cpu(es->s_inodes_count);
1466 buf->f_ffree = ext2_count_free_inodes(sb);
1467 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1468 buf->f_namelen = EXT2_NAME_LEN;
1469 buf->f_fsid = uuid_to_fsid(uuid: es->s_uuid);
1470 spin_unlock(lock: &sbi->s_lock);
1471 return 0;
1472}
1473
1474static struct dentry *ext2_mount(struct file_system_type *fs_type,
1475 int flags, const char *dev_name, void *data)
1476{
1477 return mount_bdev(fs_type, flags, dev_name, data, fill_super: ext2_fill_super);
1478}
1479
1480#ifdef CONFIG_QUOTA
1481
1482/* Read data from quotafile - avoid pagecache and such because we cannot afford
1483 * acquiring the locks... As quota files are never truncated and quota code
1484 * itself serializes the operations (and no one else should touch the files)
1485 * we don't have to be afraid of races */
1486static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1487 size_t len, loff_t off)
1488{
1489 struct inode *inode = sb_dqopt(sb)->files[type];
1490 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1491 int err = 0;
1492 int offset = off & (sb->s_blocksize - 1);
1493 int tocopy;
1494 size_t toread;
1495 struct buffer_head tmp_bh;
1496 struct buffer_head *bh;
1497 loff_t i_size = i_size_read(inode);
1498
1499 if (off > i_size)
1500 return 0;
1501 if (off+len > i_size)
1502 len = i_size-off;
1503 toread = len;
1504 while (toread > 0) {
1505 tocopy = min_t(size_t, sb->s_blocksize - offset, toread);
1506
1507 tmp_bh.b_state = 0;
1508 tmp_bh.b_size = sb->s_blocksize;
1509 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1510 if (err < 0)
1511 return err;
1512 if (!buffer_mapped(bh: &tmp_bh)) /* A hole? */
1513 memset(data, 0, tocopy);
1514 else {
1515 bh = sb_bread(sb, block: tmp_bh.b_blocknr);
1516 if (!bh)
1517 return -EIO;
1518 memcpy(data, bh->b_data+offset, tocopy);
1519 brelse(bh);
1520 }
1521 offset = 0;
1522 toread -= tocopy;
1523 data += tocopy;
1524 blk++;
1525 }
1526 return len;
1527}
1528
1529/* Write to quotafile */
1530static ssize_t ext2_quota_write(struct super_block *sb, int type,
1531 const char *data, size_t len, loff_t off)
1532{
1533 struct inode *inode = sb_dqopt(sb)->files[type];
1534 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1535 int err = 0;
1536 int offset = off & (sb->s_blocksize - 1);
1537 int tocopy;
1538 size_t towrite = len;
1539 struct buffer_head tmp_bh;
1540 struct buffer_head *bh;
1541
1542 while (towrite > 0) {
1543 tocopy = min_t(size_t, sb->s_blocksize - offset, towrite);
1544
1545 tmp_bh.b_state = 0;
1546 tmp_bh.b_size = sb->s_blocksize;
1547 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1548 if (err < 0)
1549 goto out;
1550 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1551 bh = sb_bread(sb, block: tmp_bh.b_blocknr);
1552 else
1553 bh = sb_getblk(sb, block: tmp_bh.b_blocknr);
1554 if (unlikely(!bh)) {
1555 err = -EIO;
1556 goto out;
1557 }
1558 lock_buffer(bh);
1559 memcpy(bh->b_data+offset, data, tocopy);
1560 flush_dcache_page(page: bh->b_page);
1561 set_buffer_uptodate(bh);
1562 mark_buffer_dirty(bh);
1563 unlock_buffer(bh);
1564 brelse(bh);
1565 offset = 0;
1566 towrite -= tocopy;
1567 data += tocopy;
1568 blk++;
1569 }
1570out:
1571 if (len == towrite)
1572 return err;
1573 if (inode->i_size < off+len-towrite)
1574 i_size_write(inode, i_size: off+len-towrite);
1575 inode_inc_iversion(inode);
1576 inode_set_mtime_to_ts(inode, ts: inode_set_ctime_current(inode));
1577 mark_inode_dirty(inode);
1578 return len - towrite;
1579}
1580
1581static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1582 const struct path *path)
1583{
1584 int err;
1585 struct inode *inode;
1586
1587 err = dquot_quota_on(sb, type, format_id, path);
1588 if (err)
1589 return err;
1590
1591 inode = d_inode(dentry: path->dentry);
1592 inode_lock(inode);
1593 EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1594 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1595 S_NOATIME | S_IMMUTABLE);
1596 inode_unlock(inode);
1597 mark_inode_dirty(inode);
1598
1599 return 0;
1600}
1601
1602static int ext2_quota_off(struct super_block *sb, int type)
1603{
1604 struct inode *inode = sb_dqopt(sb)->files[type];
1605 int err;
1606
1607 if (!inode || !igrab(inode))
1608 goto out;
1609
1610 err = dquot_quota_off(sb, type);
1611 if (err)
1612 goto out_put;
1613
1614 inode_lock(inode);
1615 EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1616 inode_set_flags(inode, flags: 0, S_NOATIME | S_IMMUTABLE);
1617 inode_unlock(inode);
1618 mark_inode_dirty(inode);
1619out_put:
1620 iput(inode);
1621 return err;
1622out:
1623 return dquot_quota_off(sb, type);
1624}
1625
1626#endif
1627
1628static struct file_system_type ext2_fs_type = {
1629 .owner = THIS_MODULE,
1630 .name = "ext2",
1631 .mount = ext2_mount,
1632 .kill_sb = kill_block_super,
1633 .fs_flags = FS_REQUIRES_DEV,
1634};
1635MODULE_ALIAS_FS("ext2");
1636
1637static int __init init_ext2_fs(void)
1638{
1639 int err;
1640
1641 err = init_inodecache();
1642 if (err)
1643 return err;
1644 err = register_filesystem(&ext2_fs_type);
1645 if (err)
1646 goto out;
1647 return 0;
1648out:
1649 destroy_inodecache();
1650 return err;
1651}
1652
1653static void __exit exit_ext2_fs(void)
1654{
1655 unregister_filesystem(&ext2_fs_type);
1656 destroy_inodecache();
1657}
1658
1659MODULE_AUTHOR("Remy Card and others");
1660MODULE_DESCRIPTION("Second Extended Filesystem");
1661MODULE_LICENSE("GPL");
1662module_init(init_ext2_fs)
1663module_exit(exit_ext2_fs)
1664

source code of linux/fs/ext2/super.c