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
42 static void ext2_write_super(struct super_block *sb);
43 static int ext2_remount (struct super_block * sb, int * flags, char * data);
44 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
45 static int ext2_sync_fs(struct super_block *sb, int wait);
46 static int ext2_freeze(struct super_block *sb);
47 static int ext2_unfreeze(struct super_block *sb);
48
ext2_error(struct super_block * sb,const char * function,const char * fmt,...)49 void 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
ext2_msg(struct super_block * sb,const char * prefix,const char * fmt,...)84 void 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 */
ext2_update_dynamic_rev(struct super_block * sb)103 void 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
129 static int ext2_quota_off(struct super_block *sb, int type);
130
ext2_quota_off_umount(struct super_block * sb)131 static 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
ext2_quota_off_umount(struct super_block * sb)139 static inline void ext2_quota_off_umount(struct super_block *sb)
140 {
141 }
142 #endif
143
ext2_put_super(struct super_block * sb)144 static 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 kvfree(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, NULL);
175 kfree(sbi);
176 }
177
178 static struct kmem_cache * ext2_inode_cachep;
179
ext2_alloc_inode(struct super_block * sb)180 static struct inode *ext2_alloc_inode(struct super_block *sb)
181 {
182 struct ext2_inode_info *ei;
183 ei = alloc_inode_sb(sb, 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
ext2_free_in_core_inode(struct inode * inode)195 static void ext2_free_in_core_inode(struct inode *inode)
196 {
197 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
198 }
199
init_once(void * foo)200 static 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
init_inodecache(void)212 static int __init init_inodecache(void)
213 {
214 ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
215 sizeof(struct ext2_inode_info), 0,
216 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
217 SLAB_ACCOUNT),
218 offsetof(struct ext2_inode_info, i_data),
219 sizeof_field(struct ext2_inode_info, i_data),
220 init_once);
221 if (ext2_inode_cachep == NULL)
222 return -ENOMEM;
223 return 0;
224 }
225
destroy_inodecache(void)226 static 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(ext2_inode_cachep);
234 }
235
ext2_show_options(struct seq_file * seq,struct dentry * root)236 static 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(&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(seq, ",sb=%lu", sbi->s_sb_block);
248 if (test_opt(sb, MINIX_DF))
249 seq_puts(seq, ",minixdf");
250 if (test_opt(sb, GRPID))
251 seq_puts(seq, ",grpid");
252 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
253 seq_puts(seq, ",nogrpid");
254 if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
255 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
256 seq_printf(seq, ",resuid=%u",
257 from_kuid_munged(&init_user_ns, sbi->s_resuid));
258 }
259 if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
260 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
261 seq_printf(seq, ",resgid=%u",
262 from_kgid_munged(&init_user_ns, sbi->s_resgid));
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(seq, ",errors=remount-ro");
270 }
271 }
272 if (test_opt(sb, ERRORS_CONT))
273 seq_puts(seq, ",errors=continue");
274 if (test_opt(sb, ERRORS_PANIC))
275 seq_puts(seq, ",errors=panic");
276 if (test_opt(sb, NO_UID32))
277 seq_puts(seq, ",nouid32");
278 if (test_opt(sb, DEBUG))
279 seq_puts(seq, ",debug");
280 if (test_opt(sb, OLDALLOC))
281 seq_puts(seq, ",oldalloc");
282
283 #ifdef CONFIG_EXT2_FS_XATTR
284 if (test_opt(sb, XATTR_USER))
285 seq_puts(seq, ",user_xattr");
286 if (!test_opt(sb, XATTR_USER) &&
287 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
288 seq_puts(seq, ",nouser_xattr");
289 }
290 #endif
291
292 #ifdef CONFIG_EXT2_FS_POSIX_ACL
293 if (test_opt(sb, POSIX_ACL))
294 seq_puts(seq, ",acl");
295 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
296 seq_puts(seq, ",noacl");
297 #endif
298
299 if (test_opt(sb, USRQUOTA))
300 seq_puts(seq, ",usrquota");
301
302 if (test_opt(sb, GRPQUOTA))
303 seq_puts(seq, ",grpquota");
304
305 if (test_opt(sb, XIP))
306 seq_puts(seq, ",xip");
307
308 if (test_opt(sb, DAX))
309 seq_puts(seq, ",dax");
310
311 if (!test_opt(sb, RESERVATION))
312 seq_puts(seq, ",noreservation");
313
314 spin_unlock(&sbi->s_lock);
315 return 0;
316 }
317
318 #ifdef CONFIG_QUOTA
319 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
320 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
321 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
322 const struct path *path);
ext2_get_dquots(struct inode * inode)323 static struct dquot **ext2_get_dquots(struct inode *inode)
324 {
325 return EXT2_I(inode)->i_dquot;
326 }
327
328 static const struct quotactl_ops ext2_quotactl_ops = {
329 .quota_on = ext2_quota_on,
330 .quota_off = ext2_quota_off,
331 .quota_sync = dquot_quota_sync,
332 .get_state = dquot_get_state,
333 .set_info = dquot_set_dqinfo,
334 .get_dqblk = dquot_get_dqblk,
335 .set_dqblk = dquot_set_dqblk,
336 .get_nextdqblk = dquot_get_next_dqblk,
337 };
338 #endif
339
340 static const struct super_operations ext2_sops = {
341 .alloc_inode = ext2_alloc_inode,
342 .free_inode = ext2_free_in_core_inode,
343 .write_inode = ext2_write_inode,
344 .evict_inode = ext2_evict_inode,
345 .put_super = ext2_put_super,
346 .sync_fs = ext2_sync_fs,
347 .freeze_fs = ext2_freeze,
348 .unfreeze_fs = ext2_unfreeze,
349 .statfs = ext2_statfs,
350 .remount_fs = ext2_remount,
351 .show_options = ext2_show_options,
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
ext2_nfs_get_inode(struct super_block * sb,u64 ino,u32 generation)359 static 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(-ESTALE);
366 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
367 return ERR_PTR(-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(inode))
376 return ERR_CAST(inode);
377 if (generation && inode->i_generation != generation) {
378 /* we didn't find the right inode.. */
379 iput(inode);
380 return ERR_PTR(-ESTALE);
381 }
382 return inode;
383 }
384
ext2_fh_to_dentry(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)385 static 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 ext2_nfs_get_inode);
390 }
391
ext2_fh_to_parent(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)392 static 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 ext2_nfs_get_inode);
397 }
398
399 static const struct export_operations ext2_export_ops = {
400 .fh_to_dentry = ext2_fh_to_dentry,
401 .fh_to_parent = ext2_fh_to_parent,
402 .get_parent = ext2_get_parent,
403 };
404
get_sb_block(void ** data)405 static unsigned long get_sb_block(void **data)
406 {
407 unsigned long sb_block;
408 char *options = (char *) *data;
409
410 if (!options || strncmp(options, "sb=", 3) != 0)
411 return 1; /* Default location */
412 options += 3;
413 sb_block = simple_strtoul(options, &options, 0);
414 if (*options && *options != ',') {
415 printk("EXT2-fs: Invalid sb specification: %s\n",
416 (char *) *data);
417 return 1;
418 }
419 if (*options == ',')
420 options++;
421 *data = (void *) options;
422 return sb_block;
423 }
424
425 enum {
426 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
427 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
428 Opt_err_ro, Opt_nouid32, Opt_debug,
429 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
430 Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
431 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
432 };
433
434 static const match_table_t tokens = {
435 {Opt_bsd_df, "bsddf"},
436 {Opt_minix_df, "minixdf"},
437 {Opt_grpid, "grpid"},
438 {Opt_grpid, "bsdgroups"},
439 {Opt_nogrpid, "nogrpid"},
440 {Opt_nogrpid, "sysvgroups"},
441 {Opt_resgid, "resgid=%u"},
442 {Opt_resuid, "resuid=%u"},
443 {Opt_sb, "sb=%u"},
444 {Opt_err_cont, "errors=continue"},
445 {Opt_err_panic, "errors=panic"},
446 {Opt_err_ro, "errors=remount-ro"},
447 {Opt_nouid32, "nouid32"},
448 {Opt_debug, "debug"},
449 {Opt_oldalloc, "oldalloc"},
450 {Opt_orlov, "orlov"},
451 {Opt_nobh, "nobh"},
452 {Opt_user_xattr, "user_xattr"},
453 {Opt_nouser_xattr, "nouser_xattr"},
454 {Opt_acl, "acl"},
455 {Opt_noacl, "noacl"},
456 {Opt_xip, "xip"},
457 {Opt_dax, "dax"},
458 {Opt_grpquota, "grpquota"},
459 {Opt_ignore, "noquota"},
460 {Opt_quota, "quota"},
461 {Opt_usrquota, "usrquota"},
462 {Opt_reservation, "reservation"},
463 {Opt_noreservation, "noreservation"},
464 {Opt_err, NULL}
465 };
466
parse_options(char * options,struct super_block * sb,struct ext2_mount_options * opts)467 static int parse_options(char *options, struct super_block *sb,
468 struct ext2_mount_options *opts)
469 {
470 char *p;
471 substring_t args[MAX_OPT_ARGS];
472 int option;
473 kuid_t uid;
474 kgid_t gid;
475
476 if (!options)
477 return 1;
478
479 while ((p = strsep (&options, ",")) != NULL) {
480 int token;
481 if (!*p)
482 continue;
483
484 token = match_token(p, tokens, args);
485 switch (token) {
486 case Opt_bsd_df:
487 clear_opt (opts->s_mount_opt, MINIX_DF);
488 break;
489 case Opt_minix_df:
490 set_opt (opts->s_mount_opt, MINIX_DF);
491 break;
492 case Opt_grpid:
493 set_opt (opts->s_mount_opt, GRPID);
494 break;
495 case Opt_nogrpid:
496 clear_opt (opts->s_mount_opt, GRPID);
497 break;
498 case Opt_resuid:
499 if (match_int(&args[0], &option))
500 return 0;
501 uid = make_kuid(current_user_ns(), option);
502 if (!uid_valid(uid)) {
503 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
504 return 0;
505
506 }
507 opts->s_resuid = uid;
508 break;
509 case Opt_resgid:
510 if (match_int(&args[0], &option))
511 return 0;
512 gid = make_kgid(current_user_ns(), option);
513 if (!gid_valid(gid)) {
514 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
515 return 0;
516 }
517 opts->s_resgid = gid;
518 break;
519 case Opt_sb:
520 /* handled by get_sb_block() instead of here */
521 /* *sb_block = match_int(&args[0]); */
522 break;
523 case Opt_err_panic:
524 clear_opt (opts->s_mount_opt, ERRORS_CONT);
525 clear_opt (opts->s_mount_opt, ERRORS_RO);
526 set_opt (opts->s_mount_opt, ERRORS_PANIC);
527 break;
528 case Opt_err_ro:
529 clear_opt (opts->s_mount_opt, ERRORS_CONT);
530 clear_opt (opts->s_mount_opt, ERRORS_PANIC);
531 set_opt (opts->s_mount_opt, ERRORS_RO);
532 break;
533 case Opt_err_cont:
534 clear_opt (opts->s_mount_opt, ERRORS_RO);
535 clear_opt (opts->s_mount_opt, ERRORS_PANIC);
536 set_opt (opts->s_mount_opt, ERRORS_CONT);
537 break;
538 case Opt_nouid32:
539 set_opt (opts->s_mount_opt, NO_UID32);
540 break;
541 case Opt_debug:
542 set_opt (opts->s_mount_opt, DEBUG);
543 break;
544 case Opt_oldalloc:
545 set_opt (opts->s_mount_opt, OLDALLOC);
546 break;
547 case Opt_orlov:
548 clear_opt (opts->s_mount_opt, OLDALLOC);
549 break;
550 case Opt_nobh:
551 ext2_msg(sb, KERN_INFO,
552 "nobh option not supported");
553 break;
554 #ifdef CONFIG_EXT2_FS_XATTR
555 case Opt_user_xattr:
556 set_opt (opts->s_mount_opt, XATTR_USER);
557 break;
558 case Opt_nouser_xattr:
559 clear_opt (opts->s_mount_opt, XATTR_USER);
560 break;
561 #else
562 case Opt_user_xattr:
563 case Opt_nouser_xattr:
564 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
565 "not supported");
566 break;
567 #endif
568 #ifdef CONFIG_EXT2_FS_POSIX_ACL
569 case Opt_acl:
570 set_opt(opts->s_mount_opt, POSIX_ACL);
571 break;
572 case Opt_noacl:
573 clear_opt(opts->s_mount_opt, POSIX_ACL);
574 break;
575 #else
576 case Opt_acl:
577 case Opt_noacl:
578 ext2_msg(sb, KERN_INFO,
579 "(no)acl options not supported");
580 break;
581 #endif
582 case Opt_xip:
583 ext2_msg(sb, KERN_INFO, "use dax instead of xip");
584 set_opt(opts->s_mount_opt, XIP);
585 fallthrough;
586 case Opt_dax:
587 #ifdef CONFIG_FS_DAX
588 ext2_msg(sb, KERN_WARNING,
589 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
590 set_opt(opts->s_mount_opt, DAX);
591 #else
592 ext2_msg(sb, KERN_INFO, "dax option not supported");
593 #endif
594 break;
595
596 #if defined(CONFIG_QUOTA)
597 case Opt_quota:
598 case Opt_usrquota:
599 set_opt(opts->s_mount_opt, USRQUOTA);
600 break;
601
602 case Opt_grpquota:
603 set_opt(opts->s_mount_opt, GRPQUOTA);
604 break;
605 #else
606 case Opt_quota:
607 case Opt_usrquota:
608 case Opt_grpquota:
609 ext2_msg(sb, KERN_INFO,
610 "quota operations not supported");
611 break;
612 #endif
613
614 case Opt_reservation:
615 set_opt(opts->s_mount_opt, RESERVATION);
616 ext2_msg(sb, KERN_INFO, "reservations ON");
617 break;
618 case Opt_noreservation:
619 clear_opt(opts->s_mount_opt, RESERVATION);
620 ext2_msg(sb, KERN_INFO, "reservations OFF");
621 break;
622 case Opt_ignore:
623 break;
624 default:
625 return 0;
626 }
627 }
628 return 1;
629 }
630
ext2_setup_super(struct super_block * sb,struct ext2_super_block * es,int read_only)631 static int ext2_setup_super (struct super_block * sb,
632 struct ext2_super_block * es,
633 int read_only)
634 {
635 int res = 0;
636 struct ext2_sb_info *sbi = EXT2_SB(sb);
637
638 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
639 ext2_msg(sb, KERN_ERR,
640 "error: revision level too high, "
641 "forcing read-only mode");
642 res = SB_RDONLY;
643 }
644 if (read_only)
645 return res;
646 if (!(sbi->s_mount_state & EXT2_VALID_FS))
647 ext2_msg(sb, KERN_WARNING,
648 "warning: mounting unchecked fs, "
649 "running e2fsck is recommended");
650 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
651 ext2_msg(sb, KERN_WARNING,
652 "warning: mounting fs with errors, "
653 "running e2fsck is recommended");
654 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
655 le16_to_cpu(es->s_mnt_count) >=
656 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
657 ext2_msg(sb, KERN_WARNING,
658 "warning: maximal mount count reached, "
659 "running e2fsck is recommended");
660 else if (le32_to_cpu(es->s_checkinterval) &&
661 (le32_to_cpu(es->s_lastcheck) +
662 le32_to_cpu(es->s_checkinterval) <=
663 ktime_get_real_seconds()))
664 ext2_msg(sb, KERN_WARNING,
665 "warning: checktime reached, "
666 "running e2fsck is recommended");
667 if (!le16_to_cpu(es->s_max_mnt_count))
668 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
669 le16_add_cpu(&es->s_mnt_count, 1);
670 if (test_opt (sb, DEBUG))
671 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, gc=%lu, "
672 "bpg=%lu, ipg=%lu, mo=%04lx]",
673 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
674 sbi->s_groups_count,
675 EXT2_BLOCKS_PER_GROUP(sb),
676 EXT2_INODES_PER_GROUP(sb),
677 sbi->s_mount_opt);
678 return res;
679 }
680
ext2_check_descriptors(struct super_block * sb)681 static int ext2_check_descriptors(struct super_block *sb)
682 {
683 int i;
684 struct ext2_sb_info *sbi = EXT2_SB(sb);
685
686 ext2_debug ("Checking group descriptors");
687
688 for (i = 0; i < sbi->s_groups_count; i++) {
689 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
690 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
691 ext2_fsblk_t last_block = ext2_group_last_block_no(sb, i);
692
693 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
694 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
695 {
696 ext2_error (sb, "ext2_check_descriptors",
697 "Block bitmap for group %d"
698 " not in group (block %lu)!",
699 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
700 return 0;
701 }
702 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
703 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
704 {
705 ext2_error (sb, "ext2_check_descriptors",
706 "Inode bitmap for group %d"
707 " not in group (block %lu)!",
708 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
709 return 0;
710 }
711 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
712 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
713 last_block)
714 {
715 ext2_error (sb, "ext2_check_descriptors",
716 "Inode table for group %d"
717 " not in group (block %lu)!",
718 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
719 return 0;
720 }
721 }
722 return 1;
723 }
724
725 /*
726 * Maximal file size. There is a direct, and {,double-,triple-}indirect
727 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
728 * We need to be 1 filesystem block less than the 2^32 sector limit.
729 */
ext2_max_size(int bits)730 static loff_t ext2_max_size(int bits)
731 {
732 loff_t res = EXT2_NDIR_BLOCKS;
733 int meta_blocks;
734 unsigned int upper_limit;
735 unsigned int ppb = 1 << (bits-2);
736
737 /* This is calculated to be the largest file size for a
738 * dense, file such that the total number of
739 * sectors in the file, including data and all indirect blocks,
740 * does not exceed 2^32 -1
741 * __u32 i_blocks representing the total number of
742 * 512 bytes blocks of the file
743 */
744 upper_limit = (1LL << 32) - 1;
745
746 /* total blocks in file system block size */
747 upper_limit >>= (bits - 9);
748
749 /* Compute how many blocks we can address by block tree */
750 res += 1LL << (bits-2);
751 res += 1LL << (2*(bits-2));
752 res += 1LL << (3*(bits-2));
753 /* Compute how many metadata blocks are needed */
754 meta_blocks = 1;
755 meta_blocks += 1 + ppb;
756 meta_blocks += 1 + ppb + ppb * ppb;
757 /* Does block tree limit file size? */
758 if (res + meta_blocks <= upper_limit)
759 goto check_lfs;
760
761 res = upper_limit;
762 /* How many metadata blocks are needed for addressing upper_limit? */
763 upper_limit -= EXT2_NDIR_BLOCKS;
764 /* indirect blocks */
765 meta_blocks = 1;
766 upper_limit -= ppb;
767 /* double indirect blocks */
768 if (upper_limit < ppb * ppb) {
769 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
770 res -= meta_blocks;
771 goto check_lfs;
772 }
773 meta_blocks += 1 + ppb;
774 upper_limit -= ppb * ppb;
775 /* tripple indirect blocks for the rest */
776 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
777 DIV_ROUND_UP(upper_limit, ppb*ppb);
778 res -= meta_blocks;
779 check_lfs:
780 res <<= bits;
781 if (res > MAX_LFS_FILESIZE)
782 res = MAX_LFS_FILESIZE;
783
784 return res;
785 }
786
descriptor_loc(struct super_block * sb,unsigned long logic_sb_block,int nr)787 static unsigned long descriptor_loc(struct super_block *sb,
788 unsigned long logic_sb_block,
789 int nr)
790 {
791 struct ext2_sb_info *sbi = EXT2_SB(sb);
792 unsigned long bg, first_meta_bg;
793
794 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
795
796 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
797 nr < first_meta_bg)
798 return (logic_sb_block + nr + 1);
799 bg = sbi->s_desc_per_block * nr;
800
801 return ext2_group_first_block_no(sb, bg) + ext2_bg_has_super(sb, bg);
802 }
803
ext2_fill_super(struct super_block * sb,void * data,int silent)804 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
805 {
806 struct buffer_head * bh;
807 struct ext2_sb_info * sbi;
808 struct ext2_super_block * es;
809 struct inode *root;
810 unsigned long block;
811 unsigned long sb_block = get_sb_block(&data);
812 unsigned long logic_sb_block;
813 unsigned long offset = 0;
814 unsigned long def_mount_opts;
815 long ret = -ENOMEM;
816 int blocksize = BLOCK_SIZE;
817 int db_count;
818 int i, j;
819 __le32 features;
820 int err;
821 struct ext2_mount_options opts;
822
823 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
824 if (!sbi)
825 return -ENOMEM;
826
827 sbi->s_blockgroup_lock =
828 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
829 if (!sbi->s_blockgroup_lock) {
830 kfree(sbi);
831 return -ENOMEM;
832 }
833 sb->s_fs_info = sbi;
834 sbi->s_sb_block = sb_block;
835 sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
836 NULL, NULL);
837
838 spin_lock_init(&sbi->s_lock);
839 ret = -EINVAL;
840
841 /*
842 * See what the current blocksize for the device is, and
843 * use that as the blocksize. Otherwise (or if the blocksize
844 * is smaller than the default) use the default.
845 * This is important for devices that have a hardware
846 * sectorsize that is larger than the default.
847 */
848 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
849 if (!blocksize) {
850 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
851 goto failed_sbi;
852 }
853
854 /*
855 * If the superblock doesn't start on a hardware sector boundary,
856 * calculate the offset.
857 */
858 if (blocksize != BLOCK_SIZE) {
859 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
860 offset = (sb_block*BLOCK_SIZE) % blocksize;
861 } else {
862 logic_sb_block = sb_block;
863 }
864
865 if (!(bh = sb_bread(sb, logic_sb_block))) {
866 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
867 goto failed_sbi;
868 }
869 /*
870 * Note: s_es must be initialized as soon as possible because
871 * some ext2 macro-instructions depend on its value
872 */
873 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
874 sbi->s_es = es;
875 sb->s_magic = le16_to_cpu(es->s_magic);
876
877 if (sb->s_magic != EXT2_SUPER_MAGIC)
878 goto cantfind_ext2;
879
880 opts.s_mount_opt = 0;
881 /* Set defaults before we parse the mount options */
882 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
883 if (def_mount_opts & EXT2_DEFM_DEBUG)
884 set_opt(opts.s_mount_opt, DEBUG);
885 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
886 set_opt(opts.s_mount_opt, GRPID);
887 if (def_mount_opts & EXT2_DEFM_UID16)
888 set_opt(opts.s_mount_opt, NO_UID32);
889 #ifdef CONFIG_EXT2_FS_XATTR
890 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
891 set_opt(opts.s_mount_opt, XATTR_USER);
892 #endif
893 #ifdef CONFIG_EXT2_FS_POSIX_ACL
894 if (def_mount_opts & EXT2_DEFM_ACL)
895 set_opt(opts.s_mount_opt, POSIX_ACL);
896 #endif
897
898 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
899 set_opt(opts.s_mount_opt, ERRORS_PANIC);
900 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
901 set_opt(opts.s_mount_opt, ERRORS_CONT);
902 else
903 set_opt(opts.s_mount_opt, ERRORS_RO);
904
905 opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
906 opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
907
908 set_opt(opts.s_mount_opt, RESERVATION);
909
910 if (!parse_options((char *) data, sb, &opts))
911 goto failed_mount;
912
913 sbi->s_mount_opt = opts.s_mount_opt;
914 sbi->s_resuid = opts.s_resuid;
915 sbi->s_resgid = opts.s_resgid;
916
917 sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
918 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
919 sb->s_iflags |= SB_I_CGROUPWB;
920
921 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
922 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
923 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
924 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
925 ext2_msg(sb, KERN_WARNING,
926 "warning: feature flags set on rev 0 fs, "
927 "running e2fsck is recommended");
928 /*
929 * Check feature flags regardless of the revision level, since we
930 * previously didn't change the revision level when setting the flags,
931 * so there is a chance incompat flags are set on a rev 0 filesystem.
932 */
933 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
934 if (features) {
935 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
936 "unsupported optional features (%x)",
937 le32_to_cpu(features));
938 goto failed_mount;
939 }
940 if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
941 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
942 "unsupported optional features (%x)",
943 le32_to_cpu(features));
944 goto failed_mount;
945 }
946
947 if (le32_to_cpu(es->s_log_block_size) >
948 (EXT2_MAX_BLOCK_LOG_SIZE - BLOCK_SIZE_BITS)) {
949 ext2_msg(sb, KERN_ERR,
950 "Invalid log block size: %u",
951 le32_to_cpu(es->s_log_block_size));
952 goto failed_mount;
953 }
954 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
955
956 if (test_opt(sb, DAX)) {
957 if (!sbi->s_daxdev) {
958 ext2_msg(sb, KERN_ERR,
959 "DAX unsupported by block device. Turning off DAX.");
960 clear_opt(sbi->s_mount_opt, DAX);
961 } else if (blocksize != PAGE_SIZE) {
962 ext2_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
963 clear_opt(sbi->s_mount_opt, DAX);
964 }
965 }
966
967 /* If the blocksize doesn't match, re-read the thing.. */
968 if (sb->s_blocksize != blocksize) {
969 brelse(bh);
970
971 if (!sb_set_blocksize(sb, blocksize)) {
972 ext2_msg(sb, KERN_ERR,
973 "error: bad blocksize %d", blocksize);
974 goto failed_sbi;
975 }
976
977 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
978 offset = (sb_block*BLOCK_SIZE) % blocksize;
979 bh = sb_bread(sb, logic_sb_block);
980 if(!bh) {
981 ext2_msg(sb, KERN_ERR, "error: couldn't read"
982 "superblock on 2nd try");
983 goto failed_sbi;
984 }
985 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
986 sbi->s_es = es;
987 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
988 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
989 goto failed_mount;
990 }
991 }
992
993 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
994 sb->s_max_links = EXT2_LINK_MAX;
995 sb->s_time_min = S32_MIN;
996 sb->s_time_max = S32_MAX;
997
998 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
999 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
1000 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
1001 } else {
1002 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1003 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1004 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
1005 !is_power_of_2(sbi->s_inode_size) ||
1006 (sbi->s_inode_size > blocksize)) {
1007 ext2_msg(sb, KERN_ERR,
1008 "error: unsupported inode size: %d",
1009 sbi->s_inode_size);
1010 goto failed_mount;
1011 }
1012 }
1013
1014 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1015 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1016
1017 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1018 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1019 goto cantfind_ext2;
1020 sbi->s_itb_per_group = sbi->s_inodes_per_group /
1021 sbi->s_inodes_per_block;
1022 sbi->s_desc_per_block = sb->s_blocksize /
1023 sizeof (struct ext2_group_desc);
1024 sbi->s_sbh = bh;
1025 sbi->s_mount_state = le16_to_cpu(es->s_state);
1026 sbi->s_addr_per_block_bits =
1027 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1028 sbi->s_desc_per_block_bits =
1029 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1030
1031 if (sb->s_magic != EXT2_SUPER_MAGIC)
1032 goto cantfind_ext2;
1033
1034 if (sb->s_blocksize != bh->b_size) {
1035 if (!silent)
1036 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1037 goto failed_mount;
1038 }
1039
1040 if (es->s_log_frag_size != es->s_log_block_size) {
1041 ext2_msg(sb, KERN_ERR,
1042 "error: fragsize log %u != blocksize log %u",
1043 le32_to_cpu(es->s_log_frag_size), sb->s_blocksize_bits);
1044 goto failed_mount;
1045 }
1046
1047 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1048 ext2_msg(sb, KERN_ERR,
1049 "error: #blocks per group too big: %lu",
1050 sbi->s_blocks_per_group);
1051 goto failed_mount;
1052 }
1053 /* At least inode table, bitmaps, and sb have to fit in one group */
1054 if (sbi->s_blocks_per_group <= sbi->s_itb_per_group + 3) {
1055 ext2_msg(sb, KERN_ERR,
1056 "error: #blocks per group smaller than metadata size: %lu <= %lu",
1057 sbi->s_blocks_per_group, sbi->s_inodes_per_group + 3);
1058 goto failed_mount;
1059 }
1060 if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
1061 sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1062 ext2_msg(sb, KERN_ERR,
1063 "error: invalid #inodes per group: %lu",
1064 sbi->s_inodes_per_group);
1065 goto failed_mount;
1066 }
1067 if (sb_bdev_nr_blocks(sb) < le32_to_cpu(es->s_blocks_count)) {
1068 ext2_msg(sb, KERN_ERR,
1069 "bad geometry: block count %u exceeds size of device (%u blocks)",
1070 le32_to_cpu(es->s_blocks_count),
1071 (unsigned)sb_bdev_nr_blocks(sb));
1072 goto failed_mount;
1073 }
1074
1075 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1076 le32_to_cpu(es->s_first_data_block) - 1)
1077 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1078 if ((u64)sbi->s_groups_count * sbi->s_inodes_per_group !=
1079 le32_to_cpu(es->s_inodes_count)) {
1080 ext2_msg(sb, KERN_ERR, "error: invalid #inodes: %u vs computed %llu",
1081 le32_to_cpu(es->s_inodes_count),
1082 (u64)sbi->s_groups_count * sbi->s_inodes_per_group);
1083 goto failed_mount;
1084 }
1085 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1086 EXT2_DESC_PER_BLOCK(sb);
1087 sbi->s_group_desc = kvmalloc_array(db_count,
1088 sizeof(struct buffer_head *),
1089 GFP_KERNEL);
1090 if (sbi->s_group_desc == NULL) {
1091 ret = -ENOMEM;
1092 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1093 goto failed_mount;
1094 }
1095 bgl_lock_init(sbi->s_blockgroup_lock);
1096 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1097 if (!sbi->s_debts) {
1098 ret = -ENOMEM;
1099 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1100 goto failed_mount_group_desc;
1101 }
1102 for (i = 0; i < db_count; i++) {
1103 block = descriptor_loc(sb, logic_sb_block, i);
1104 sbi->s_group_desc[i] = sb_bread(sb, block);
1105 if (!sbi->s_group_desc[i]) {
1106 for (j = 0; j < i; j++)
1107 brelse (sbi->s_group_desc[j]);
1108 ext2_msg(sb, KERN_ERR,
1109 "error: unable to read group descriptors");
1110 goto failed_mount_group_desc;
1111 }
1112 }
1113 if (!ext2_check_descriptors (sb)) {
1114 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1115 goto failed_mount2;
1116 }
1117 sbi->s_gdb_count = db_count;
1118 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1119 spin_lock_init(&sbi->s_next_gen_lock);
1120
1121 /* per filesystem reservation list head & lock */
1122 spin_lock_init(&sbi->s_rsv_window_lock);
1123 sbi->s_rsv_window_root = RB_ROOT;
1124 /*
1125 * Add a single, static dummy reservation to the start of the
1126 * reservation window list --- it gives us a placeholder for
1127 * append-at-start-of-list which makes the allocation logic
1128 * _much_ simpler.
1129 */
1130 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1131 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1132 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1133 sbi->s_rsv_window_head.rsv_goal_size = 0;
1134 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1135
1136 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1137 ext2_count_free_blocks(sb), GFP_KERNEL);
1138 if (!err) {
1139 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1140 ext2_count_free_inodes(sb), GFP_KERNEL);
1141 }
1142 if (!err) {
1143 err = percpu_counter_init(&sbi->s_dirs_counter,
1144 ext2_count_dirs(sb), GFP_KERNEL);
1145 }
1146 if (err) {
1147 ret = err;
1148 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1149 goto failed_mount3;
1150 }
1151
1152 #ifdef CONFIG_EXT2_FS_XATTR
1153 sbi->s_ea_block_cache = ext2_xattr_create_cache();
1154 if (!sbi->s_ea_block_cache) {
1155 ret = -ENOMEM;
1156 ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1157 goto failed_mount3;
1158 }
1159 #endif
1160 /*
1161 * set up enough so that it can read an inode
1162 */
1163 sb->s_op = &ext2_sops;
1164 sb->s_export_op = &ext2_export_ops;
1165 sb->s_xattr = ext2_xattr_handlers;
1166
1167 #ifdef CONFIG_QUOTA
1168 sb->dq_op = &dquot_operations;
1169 sb->s_qcop = &ext2_quotactl_ops;
1170 sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1171 #endif
1172
1173 root = ext2_iget(sb, EXT2_ROOT_INO);
1174 if (IS_ERR(root)) {
1175 ret = PTR_ERR(root);
1176 goto failed_mount3;
1177 }
1178 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1179 iput(root);
1180 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1181 goto failed_mount3;
1182 }
1183
1184 sb->s_root = d_make_root(root);
1185 if (!sb->s_root) {
1186 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1187 ret = -ENOMEM;
1188 goto failed_mount3;
1189 }
1190 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1191 ext2_msg(sb, KERN_WARNING,
1192 "warning: mounting ext3 filesystem as ext2");
1193 if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1194 sb->s_flags |= SB_RDONLY;
1195 ext2_write_super(sb);
1196 return 0;
1197
1198 cantfind_ext2:
1199 if (!silent)
1200 ext2_msg(sb, KERN_ERR,
1201 "error: can't find an ext2 filesystem on dev %s.",
1202 sb->s_id);
1203 goto failed_mount;
1204 failed_mount3:
1205 ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1206 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1207 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1208 percpu_counter_destroy(&sbi->s_dirs_counter);
1209 failed_mount2:
1210 for (i = 0; i < db_count; i++)
1211 brelse(sbi->s_group_desc[i]);
1212 failed_mount_group_desc:
1213 kvfree(sbi->s_group_desc);
1214 kfree(sbi->s_debts);
1215 failed_mount:
1216 brelse(bh);
1217 failed_sbi:
1218 fs_put_dax(sbi->s_daxdev, NULL);
1219 sb->s_fs_info = NULL;
1220 kfree(sbi->s_blockgroup_lock);
1221 kfree(sbi);
1222 return ret;
1223 }
1224
ext2_clear_super_error(struct super_block * sb)1225 static void ext2_clear_super_error(struct super_block *sb)
1226 {
1227 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1228
1229 if (buffer_write_io_error(sbh)) {
1230 /*
1231 * Oh, dear. A previous attempt to write the
1232 * superblock failed. This could happen because the
1233 * USB device was yanked out. Or it could happen to
1234 * be a transient write error and maybe the block will
1235 * be remapped. Nothing we can do but to retry the
1236 * write and hope for the best.
1237 */
1238 ext2_msg(sb, KERN_ERR,
1239 "previous I/O error to superblock detected");
1240 clear_buffer_write_io_error(sbh);
1241 set_buffer_uptodate(sbh);
1242 }
1243 }
1244
ext2_sync_super(struct super_block * sb,struct ext2_super_block * es,int wait)1245 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1246 int wait)
1247 {
1248 ext2_clear_super_error(sb);
1249 spin_lock(&EXT2_SB(sb)->s_lock);
1250 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1251 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1252 es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1253 /* unlock before we do IO */
1254 spin_unlock(&EXT2_SB(sb)->s_lock);
1255 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1256 if (wait)
1257 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1258 }
1259
1260 /*
1261 * In the second extended file system, it is not necessary to
1262 * write the super block since we use a mapping of the
1263 * disk super block in a buffer.
1264 *
1265 * However, this function is still used to set the fs valid
1266 * flags to 0. We need to set this flag to 0 since the fs
1267 * may have been checked while mounted and e2fsck may have
1268 * set s_state to EXT2_VALID_FS after some corrections.
1269 */
ext2_sync_fs(struct super_block * sb,int wait)1270 static int ext2_sync_fs(struct super_block *sb, int wait)
1271 {
1272 struct ext2_sb_info *sbi = EXT2_SB(sb);
1273 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1274
1275 /*
1276 * Write quota structures to quota file, sync_blockdev() will write
1277 * them to disk later
1278 */
1279 dquot_writeback_dquots(sb, -1);
1280
1281 spin_lock(&sbi->s_lock);
1282 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1283 ext2_debug("setting valid to 0\n");
1284 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1285 }
1286 spin_unlock(&sbi->s_lock);
1287 ext2_sync_super(sb, es, wait);
1288 return 0;
1289 }
1290
ext2_freeze(struct super_block * sb)1291 static int ext2_freeze(struct super_block *sb)
1292 {
1293 struct ext2_sb_info *sbi = EXT2_SB(sb);
1294
1295 /*
1296 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1297 * because we have unattached inodes and thus filesystem is not fully
1298 * consistent.
1299 */
1300 if (atomic_long_read(&sb->s_remove_count)) {
1301 ext2_sync_fs(sb, 1);
1302 return 0;
1303 }
1304 /* Set EXT2_FS_VALID flag */
1305 spin_lock(&sbi->s_lock);
1306 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1307 spin_unlock(&sbi->s_lock);
1308 ext2_sync_super(sb, sbi->s_es, 1);
1309
1310 return 0;
1311 }
1312
ext2_unfreeze(struct super_block * sb)1313 static int ext2_unfreeze(struct super_block *sb)
1314 {
1315 /* Just write sb to clear EXT2_VALID_FS flag */
1316 ext2_write_super(sb);
1317
1318 return 0;
1319 }
1320
ext2_write_super(struct super_block * sb)1321 static void ext2_write_super(struct super_block *sb)
1322 {
1323 if (!sb_rdonly(sb))
1324 ext2_sync_fs(sb, 1);
1325 }
1326
ext2_remount(struct super_block * sb,int * flags,char * data)1327 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1328 {
1329 struct ext2_sb_info * sbi = EXT2_SB(sb);
1330 struct ext2_super_block * es;
1331 struct ext2_mount_options new_opts;
1332 int err;
1333
1334 sync_filesystem(sb);
1335
1336 spin_lock(&sbi->s_lock);
1337 new_opts.s_mount_opt = sbi->s_mount_opt;
1338 new_opts.s_resuid = sbi->s_resuid;
1339 new_opts.s_resgid = sbi->s_resgid;
1340 spin_unlock(&sbi->s_lock);
1341
1342 if (!parse_options(data, sb, &new_opts))
1343 return -EINVAL;
1344
1345 spin_lock(&sbi->s_lock);
1346 es = sbi->s_es;
1347 if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1348 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1349 "dax flag with busy inodes while remounting");
1350 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1351 }
1352 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1353 goto out_set;
1354 if (*flags & SB_RDONLY) {
1355 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1356 !(sbi->s_mount_state & EXT2_VALID_FS))
1357 goto out_set;
1358
1359 /*
1360 * OK, we are remounting a valid rw partition rdonly, so set
1361 * the rdonly flag and then mark the partition as valid again.
1362 */
1363 es->s_state = cpu_to_le16(sbi->s_mount_state);
1364 es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1365 spin_unlock(&sbi->s_lock);
1366
1367 err = dquot_suspend(sb, -1);
1368 if (err < 0)
1369 return err;
1370
1371 ext2_sync_super(sb, es, 1);
1372 } else {
1373 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1374 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1375 if (ret) {
1376 spin_unlock(&sbi->s_lock);
1377 ext2_msg(sb, KERN_WARNING,
1378 "warning: couldn't remount RDWR because of "
1379 "unsupported optional features (%x).",
1380 le32_to_cpu(ret));
1381 return -EROFS;
1382 }
1383 /*
1384 * Mounting a RDONLY partition read-write, so reread and
1385 * store the current valid flag. (It may have been changed
1386 * by e2fsck since we originally mounted the partition.)
1387 */
1388 sbi->s_mount_state = le16_to_cpu(es->s_state);
1389 if (!ext2_setup_super (sb, es, 0))
1390 sb->s_flags &= ~SB_RDONLY;
1391 spin_unlock(&sbi->s_lock);
1392
1393 ext2_write_super(sb);
1394
1395 dquot_resume(sb, -1);
1396 }
1397
1398 spin_lock(&sbi->s_lock);
1399 out_set:
1400 sbi->s_mount_opt = new_opts.s_mount_opt;
1401 sbi->s_resuid = new_opts.s_resuid;
1402 sbi->s_resgid = new_opts.s_resgid;
1403 sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1404 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
1405 spin_unlock(&sbi->s_lock);
1406
1407 return 0;
1408 }
1409
ext2_statfs(struct dentry * dentry,struct kstatfs * buf)1410 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1411 {
1412 struct super_block *sb = dentry->d_sb;
1413 struct ext2_sb_info *sbi = EXT2_SB(sb);
1414 struct ext2_super_block *es = sbi->s_es;
1415
1416 spin_lock(&sbi->s_lock);
1417
1418 if (test_opt (sb, MINIX_DF))
1419 sbi->s_overhead_last = 0;
1420 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1421 unsigned long i, overhead = 0;
1422 smp_rmb();
1423
1424 /*
1425 * Compute the overhead (FS structures). This is constant
1426 * for a given filesystem unless the number of block groups
1427 * changes so we cache the previous value until it does.
1428 */
1429
1430 /*
1431 * All of the blocks before first_data_block are
1432 * overhead
1433 */
1434 overhead = le32_to_cpu(es->s_first_data_block);
1435
1436 /*
1437 * Add the overhead attributed to the superblock and
1438 * block group descriptors. If the sparse superblocks
1439 * feature is turned on, then not all groups have this.
1440 */
1441 for (i = 0; i < sbi->s_groups_count; i++)
1442 overhead += ext2_bg_has_super(sb, i) +
1443 ext2_bg_num_gdb(sb, i);
1444
1445 /*
1446 * Every block group has an inode bitmap, a block
1447 * bitmap, and an inode table.
1448 */
1449 overhead += (sbi->s_groups_count *
1450 (2 + sbi->s_itb_per_group));
1451 sbi->s_overhead_last = overhead;
1452 smp_wmb();
1453 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1454 }
1455
1456 buf->f_type = EXT2_SUPER_MAGIC;
1457 buf->f_bsize = sb->s_blocksize;
1458 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1459 buf->f_bfree = ext2_count_free_blocks(sb);
1460 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1461 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1462 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1463 buf->f_bavail = 0;
1464 buf->f_files = le32_to_cpu(es->s_inodes_count);
1465 buf->f_ffree = ext2_count_free_inodes(sb);
1466 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1467 buf->f_namelen = EXT2_NAME_LEN;
1468 buf->f_fsid = uuid_to_fsid(es->s_uuid);
1469 spin_unlock(&sbi->s_lock);
1470 return 0;
1471 }
1472
ext2_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)1473 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1474 int flags, const char *dev_name, void *data)
1475 {
1476 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1477 }
1478
1479 #ifdef CONFIG_QUOTA
1480
1481 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1482 * acquiring the locks... As quota files are never truncated and quota code
1483 * itself serializes the operations (and no one else should touch the files)
1484 * we don't have to be afraid of races */
ext2_quota_read(struct super_block * sb,int type,char * data,size_t len,loff_t off)1485 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1486 size_t len, loff_t off)
1487 {
1488 struct inode *inode = sb_dqopt(sb)->files[type];
1489 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1490 int err = 0;
1491 int offset = off & (sb->s_blocksize - 1);
1492 int tocopy;
1493 size_t toread;
1494 struct buffer_head tmp_bh;
1495 struct buffer_head *bh;
1496 loff_t i_size = i_size_read(inode);
1497
1498 if (off > i_size)
1499 return 0;
1500 if (off+len > i_size)
1501 len = i_size-off;
1502 toread = len;
1503 while (toread > 0) {
1504 tocopy = min_t(size_t, sb->s_blocksize - offset, toread);
1505
1506 tmp_bh.b_state = 0;
1507 tmp_bh.b_size = sb->s_blocksize;
1508 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1509 if (err < 0)
1510 return err;
1511 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1512 memset(data, 0, tocopy);
1513 else {
1514 bh = sb_bread(sb, tmp_bh.b_blocknr);
1515 if (!bh)
1516 return -EIO;
1517 memcpy(data, bh->b_data+offset, tocopy);
1518 brelse(bh);
1519 }
1520 offset = 0;
1521 toread -= tocopy;
1522 data += tocopy;
1523 blk++;
1524 }
1525 return len;
1526 }
1527
1528 /* Write to quotafile */
ext2_quota_write(struct super_block * sb,int type,const char * data,size_t len,loff_t off)1529 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1530 const char *data, size_t len, loff_t off)
1531 {
1532 struct inode *inode = sb_dqopt(sb)->files[type];
1533 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1534 int err = 0;
1535 int offset = off & (sb->s_blocksize - 1);
1536 int tocopy;
1537 size_t towrite = len;
1538 struct buffer_head tmp_bh;
1539 struct buffer_head *bh;
1540
1541 while (towrite > 0) {
1542 tocopy = min_t(size_t, sb->s_blocksize - offset, towrite);
1543
1544 tmp_bh.b_state = 0;
1545 tmp_bh.b_size = sb->s_blocksize;
1546 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1547 if (err < 0)
1548 goto out;
1549 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1550 bh = sb_bread(sb, tmp_bh.b_blocknr);
1551 else
1552 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1553 if (unlikely(!bh)) {
1554 err = -EIO;
1555 goto out;
1556 }
1557 lock_buffer(bh);
1558 memcpy(bh->b_data+offset, data, tocopy);
1559 flush_dcache_page(bh->b_page);
1560 set_buffer_uptodate(bh);
1561 mark_buffer_dirty(bh);
1562 unlock_buffer(bh);
1563 brelse(bh);
1564 offset = 0;
1565 towrite -= tocopy;
1566 data += tocopy;
1567 blk++;
1568 }
1569 out:
1570 if (len == towrite)
1571 return err;
1572 if (inode->i_size < off+len-towrite)
1573 i_size_write(inode, off+len-towrite);
1574 inode_inc_iversion(inode);
1575 inode->i_mtime = inode_set_ctime_current(inode);
1576 mark_inode_dirty(inode);
1577 return len - towrite;
1578 }
1579
ext2_quota_on(struct super_block * sb,int type,int format_id,const struct path * path)1580 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1581 const struct path *path)
1582 {
1583 int err;
1584 struct inode *inode;
1585
1586 err = dquot_quota_on(sb, type, format_id, path);
1587 if (err)
1588 return err;
1589
1590 inode = d_inode(path->dentry);
1591 inode_lock(inode);
1592 EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1593 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1594 S_NOATIME | S_IMMUTABLE);
1595 inode_unlock(inode);
1596 mark_inode_dirty(inode);
1597
1598 return 0;
1599 }
1600
ext2_quota_off(struct super_block * sb,int type)1601 static int ext2_quota_off(struct super_block *sb, int type)
1602 {
1603 struct inode *inode = sb_dqopt(sb)->files[type];
1604 int err;
1605
1606 if (!inode || !igrab(inode))
1607 goto out;
1608
1609 err = dquot_quota_off(sb, type);
1610 if (err)
1611 goto out_put;
1612
1613 inode_lock(inode);
1614 EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1615 inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1616 inode_unlock(inode);
1617 mark_inode_dirty(inode);
1618 out_put:
1619 iput(inode);
1620 return err;
1621 out:
1622 return dquot_quota_off(sb, type);
1623 }
1624
1625 #endif
1626
1627 static struct file_system_type ext2_fs_type = {
1628 .owner = THIS_MODULE,
1629 .name = "ext2",
1630 .mount = ext2_mount,
1631 .kill_sb = kill_block_super,
1632 .fs_flags = FS_REQUIRES_DEV,
1633 };
1634 MODULE_ALIAS_FS("ext2");
1635
init_ext2_fs(void)1636 static int __init init_ext2_fs(void)
1637 {
1638 int err;
1639
1640 err = init_inodecache();
1641 if (err)
1642 return err;
1643 err = register_filesystem(&ext2_fs_type);
1644 if (err)
1645 goto out;
1646 return 0;
1647 out:
1648 destroy_inodecache();
1649 return err;
1650 }
1651
exit_ext2_fs(void)1652 static void __exit exit_ext2_fs(void)
1653 {
1654 unregister_filesystem(&ext2_fs_type);
1655 destroy_inodecache();
1656 }
1657
1658 MODULE_AUTHOR("Remy Card and others");
1659 MODULE_DESCRIPTION("Second Extended Filesystem");
1660 MODULE_LICENSE("GPL");
1661 module_init(init_ext2_fs)
1662 module_exit(exit_ext2_fs)
1663
