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);
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 = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
184 if (!ei)
185 return NULL;
186 ei->i_block_alloc_info = NULL;
187 inode_set_iversion(&ei->vfs_inode, 1);
188 #ifdef CONFIG_QUOTA
189 memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
190 #endif
191
192 return &ei->vfs_inode;
193 }
194
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, NOBH))
300 seq_puts(seq, ",nobh");
301
302 if (test_opt(sb, USRQUOTA))
303 seq_puts(seq, ",usrquota");
304
305 if (test_opt(sb, GRPQUOTA))
306 seq_puts(seq, ",grpquota");
307
308 if (test_opt(sb, XIP))
309 seq_puts(seq, ",xip");
310
311 if (test_opt(sb, DAX))
312 seq_puts(seq, ",dax");
313
314 if (!test_opt(sb, RESERVATION))
315 seq_puts(seq, ",noreservation");
316
317 spin_unlock(&sbi->s_lock);
318 return 0;
319 }
320
321 #ifdef CONFIG_QUOTA
322 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
323 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
324 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
325 const struct path *path);
ext2_get_dquots(struct inode * inode)326 static struct dquot **ext2_get_dquots(struct inode *inode)
327 {
328 return EXT2_I(inode)->i_dquot;
329 }
330
331 static const struct quotactl_ops ext2_quotactl_ops = {
332 .quota_on = ext2_quota_on,
333 .quota_off = ext2_quota_off,
334 .quota_sync = dquot_quota_sync,
335 .get_state = dquot_get_state,
336 .set_info = dquot_set_dqinfo,
337 .get_dqblk = dquot_get_dqblk,
338 .set_dqblk = dquot_set_dqblk,
339 .get_nextdqblk = dquot_get_next_dqblk,
340 };
341 #endif
342
343 static const struct super_operations ext2_sops = {
344 .alloc_inode = ext2_alloc_inode,
345 .free_inode = ext2_free_in_core_inode,
346 .write_inode = ext2_write_inode,
347 .evict_inode = ext2_evict_inode,
348 .put_super = ext2_put_super,
349 .sync_fs = ext2_sync_fs,
350 .freeze_fs = ext2_freeze,
351 .unfreeze_fs = ext2_unfreeze,
352 .statfs = ext2_statfs,
353 .remount_fs = ext2_remount,
354 .show_options = ext2_show_options,
355 #ifdef CONFIG_QUOTA
356 .quota_read = ext2_quota_read,
357 .quota_write = ext2_quota_write,
358 .get_dquots = ext2_get_dquots,
359 #endif
360 };
361
ext2_nfs_get_inode(struct super_block * sb,u64 ino,u32 generation)362 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
363 u64 ino, u32 generation)
364 {
365 struct inode *inode;
366
367 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
368 return ERR_PTR(-ESTALE);
369 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
370 return ERR_PTR(-ESTALE);
371
372 /*
373 * ext2_iget isn't quite right if the inode is currently unallocated!
374 * However ext2_iget currently does appropriate checks to handle stale
375 * inodes so everything is OK.
376 */
377 inode = ext2_iget(sb, ino);
378 if (IS_ERR(inode))
379 return ERR_CAST(inode);
380 if (generation && inode->i_generation != generation) {
381 /* we didn't find the right inode.. */
382 iput(inode);
383 return ERR_PTR(-ESTALE);
384 }
385 return inode;
386 }
387
ext2_fh_to_dentry(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)388 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
389 int fh_len, int fh_type)
390 {
391 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
392 ext2_nfs_get_inode);
393 }
394
ext2_fh_to_parent(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)395 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
396 int fh_len, int fh_type)
397 {
398 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
399 ext2_nfs_get_inode);
400 }
401
402 static const struct export_operations ext2_export_ops = {
403 .fh_to_dentry = ext2_fh_to_dentry,
404 .fh_to_parent = ext2_fh_to_parent,
405 .get_parent = ext2_get_parent,
406 };
407
get_sb_block(void ** data)408 static unsigned long get_sb_block(void **data)
409 {
410 unsigned long sb_block;
411 char *options = (char *) *data;
412
413 if (!options || strncmp(options, "sb=", 3) != 0)
414 return 1; /* Default location */
415 options += 3;
416 sb_block = simple_strtoul(options, &options, 0);
417 if (*options && *options != ',') {
418 printk("EXT2-fs: Invalid sb specification: %s\n",
419 (char *) *data);
420 return 1;
421 }
422 if (*options == ',')
423 options++;
424 *data = (void *) options;
425 return sb_block;
426 }
427
428 enum {
429 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
430 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
431 Opt_err_ro, Opt_nouid32, Opt_debug,
432 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
433 Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
434 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
435 };
436
437 static const match_table_t tokens = {
438 {Opt_bsd_df, "bsddf"},
439 {Opt_minix_df, "minixdf"},
440 {Opt_grpid, "grpid"},
441 {Opt_grpid, "bsdgroups"},
442 {Opt_nogrpid, "nogrpid"},
443 {Opt_nogrpid, "sysvgroups"},
444 {Opt_resgid, "resgid=%u"},
445 {Opt_resuid, "resuid=%u"},
446 {Opt_sb, "sb=%u"},
447 {Opt_err_cont, "errors=continue"},
448 {Opt_err_panic, "errors=panic"},
449 {Opt_err_ro, "errors=remount-ro"},
450 {Opt_nouid32, "nouid32"},
451 {Opt_debug, "debug"},
452 {Opt_oldalloc, "oldalloc"},
453 {Opt_orlov, "orlov"},
454 {Opt_nobh, "nobh"},
455 {Opt_user_xattr, "user_xattr"},
456 {Opt_nouser_xattr, "nouser_xattr"},
457 {Opt_acl, "acl"},
458 {Opt_noacl, "noacl"},
459 {Opt_xip, "xip"},
460 {Opt_dax, "dax"},
461 {Opt_grpquota, "grpquota"},
462 {Opt_ignore, "noquota"},
463 {Opt_quota, "quota"},
464 {Opt_usrquota, "usrquota"},
465 {Opt_reservation, "reservation"},
466 {Opt_noreservation, "noreservation"},
467 {Opt_err, NULL}
468 };
469
parse_options(char * options,struct super_block * sb,struct ext2_mount_options * opts)470 static int parse_options(char *options, struct super_block *sb,
471 struct ext2_mount_options *opts)
472 {
473 char *p;
474 substring_t args[MAX_OPT_ARGS];
475 int option;
476 kuid_t uid;
477 kgid_t gid;
478
479 if (!options)
480 return 1;
481
482 while ((p = strsep (&options, ",")) != NULL) {
483 int token;
484 if (!*p)
485 continue;
486
487 token = match_token(p, tokens, args);
488 switch (token) {
489 case Opt_bsd_df:
490 clear_opt (opts->s_mount_opt, MINIX_DF);
491 break;
492 case Opt_minix_df:
493 set_opt (opts->s_mount_opt, MINIX_DF);
494 break;
495 case Opt_grpid:
496 set_opt (opts->s_mount_opt, GRPID);
497 break;
498 case Opt_nogrpid:
499 clear_opt (opts->s_mount_opt, GRPID);
500 break;
501 case Opt_resuid:
502 if (match_int(&args[0], &option))
503 return 0;
504 uid = make_kuid(current_user_ns(), option);
505 if (!uid_valid(uid)) {
506 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
507 return 0;
508
509 }
510 opts->s_resuid = uid;
511 break;
512 case Opt_resgid:
513 if (match_int(&args[0], &option))
514 return 0;
515 gid = make_kgid(current_user_ns(), option);
516 if (!gid_valid(gid)) {
517 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
518 return 0;
519 }
520 opts->s_resgid = gid;
521 break;
522 case Opt_sb:
523 /* handled by get_sb_block() instead of here */
524 /* *sb_block = match_int(&args[0]); */
525 break;
526 case Opt_err_panic:
527 clear_opt (opts->s_mount_opt, ERRORS_CONT);
528 clear_opt (opts->s_mount_opt, ERRORS_RO);
529 set_opt (opts->s_mount_opt, ERRORS_PANIC);
530 break;
531 case Opt_err_ro:
532 clear_opt (opts->s_mount_opt, ERRORS_CONT);
533 clear_opt (opts->s_mount_opt, ERRORS_PANIC);
534 set_opt (opts->s_mount_opt, ERRORS_RO);
535 break;
536 case Opt_err_cont:
537 clear_opt (opts->s_mount_opt, ERRORS_RO);
538 clear_opt (opts->s_mount_opt, ERRORS_PANIC);
539 set_opt (opts->s_mount_opt, ERRORS_CONT);
540 break;
541 case Opt_nouid32:
542 set_opt (opts->s_mount_opt, NO_UID32);
543 break;
544 case Opt_debug:
545 set_opt (opts->s_mount_opt, DEBUG);
546 break;
547 case Opt_oldalloc:
548 set_opt (opts->s_mount_opt, OLDALLOC);
549 break;
550 case Opt_orlov:
551 clear_opt (opts->s_mount_opt, OLDALLOC);
552 break;
553 case Opt_nobh:
554 set_opt (opts->s_mount_opt, NOBH);
555 break;
556 #ifdef CONFIG_EXT2_FS_XATTR
557 case Opt_user_xattr:
558 set_opt (opts->s_mount_opt, XATTR_USER);
559 break;
560 case Opt_nouser_xattr:
561 clear_opt (opts->s_mount_opt, XATTR_USER);
562 break;
563 #else
564 case Opt_user_xattr:
565 case Opt_nouser_xattr:
566 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
567 "not supported");
568 break;
569 #endif
570 #ifdef CONFIG_EXT2_FS_POSIX_ACL
571 case Opt_acl:
572 set_opt(opts->s_mount_opt, POSIX_ACL);
573 break;
574 case Opt_noacl:
575 clear_opt(opts->s_mount_opt, POSIX_ACL);
576 break;
577 #else
578 case Opt_acl:
579 case Opt_noacl:
580 ext2_msg(sb, KERN_INFO,
581 "(no)acl options not supported");
582 break;
583 #endif
584 case Opt_xip:
585 ext2_msg(sb, KERN_INFO, "use dax instead of xip");
586 set_opt(opts->s_mount_opt, XIP);
587 fallthrough;
588 case Opt_dax:
589 #ifdef CONFIG_FS_DAX
590 ext2_msg(sb, KERN_WARNING,
591 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
592 set_opt(opts->s_mount_opt, DAX);
593 #else
594 ext2_msg(sb, KERN_INFO, "dax option not supported");
595 #endif
596 break;
597
598 #if defined(CONFIG_QUOTA)
599 case Opt_quota:
600 case Opt_usrquota:
601 set_opt(opts->s_mount_opt, USRQUOTA);
602 break;
603
604 case Opt_grpquota:
605 set_opt(opts->s_mount_opt, GRPQUOTA);
606 break;
607 #else
608 case Opt_quota:
609 case Opt_usrquota:
610 case Opt_grpquota:
611 ext2_msg(sb, KERN_INFO,
612 "quota operations not supported");
613 break;
614 #endif
615
616 case Opt_reservation:
617 set_opt(opts->s_mount_opt, RESERVATION);
618 ext2_msg(sb, KERN_INFO, "reservations ON");
619 break;
620 case Opt_noreservation:
621 clear_opt(opts->s_mount_opt, RESERVATION);
622 ext2_msg(sb, KERN_INFO, "reservations OFF");
623 break;
624 case Opt_ignore:
625 break;
626 default:
627 return 0;
628 }
629 }
630 return 1;
631 }
632
ext2_setup_super(struct super_block * sb,struct ext2_super_block * es,int read_only)633 static int ext2_setup_super (struct super_block * sb,
634 struct ext2_super_block * es,
635 int read_only)
636 {
637 int res = 0;
638 struct ext2_sb_info *sbi = EXT2_SB(sb);
639
640 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
641 ext2_msg(sb, KERN_ERR,
642 "error: revision level too high, "
643 "forcing read-only mode");
644 res = SB_RDONLY;
645 }
646 if (read_only)
647 return res;
648 if (!(sbi->s_mount_state & EXT2_VALID_FS))
649 ext2_msg(sb, KERN_WARNING,
650 "warning: mounting unchecked fs, "
651 "running e2fsck is recommended");
652 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
653 ext2_msg(sb, KERN_WARNING,
654 "warning: mounting fs with errors, "
655 "running e2fsck is recommended");
656 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
657 le16_to_cpu(es->s_mnt_count) >=
658 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
659 ext2_msg(sb, KERN_WARNING,
660 "warning: maximal mount count reached, "
661 "running e2fsck is recommended");
662 else if (le32_to_cpu(es->s_checkinterval) &&
663 (le32_to_cpu(es->s_lastcheck) +
664 le32_to_cpu(es->s_checkinterval) <=
665 ktime_get_real_seconds()))
666 ext2_msg(sb, KERN_WARNING,
667 "warning: checktime reached, "
668 "running e2fsck is recommended");
669 if (!le16_to_cpu(es->s_max_mnt_count))
670 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
671 le16_add_cpu(&es->s_mnt_count, 1);
672 if (test_opt (sb, DEBUG))
673 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, gc=%lu, "
674 "bpg=%lu, ipg=%lu, mo=%04lx]",
675 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
676 sbi->s_groups_count,
677 EXT2_BLOCKS_PER_GROUP(sb),
678 EXT2_INODES_PER_GROUP(sb),
679 sbi->s_mount_opt);
680 return res;
681 }
682
ext2_check_descriptors(struct super_block * sb)683 static int ext2_check_descriptors(struct super_block *sb)
684 {
685 int i;
686 struct ext2_sb_info *sbi = EXT2_SB(sb);
687
688 ext2_debug ("Checking group descriptors");
689
690 for (i = 0; i < sbi->s_groups_count; i++) {
691 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
692 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
693 ext2_fsblk_t last_block = ext2_group_last_block_no(sb, i);
694
695 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
696 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
697 {
698 ext2_error (sb, "ext2_check_descriptors",
699 "Block bitmap for group %d"
700 " not in group (block %lu)!",
701 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
702 return 0;
703 }
704 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
705 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
706 {
707 ext2_error (sb, "ext2_check_descriptors",
708 "Inode bitmap for group %d"
709 " not in group (block %lu)!",
710 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
711 return 0;
712 }
713 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
714 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
715 last_block)
716 {
717 ext2_error (sb, "ext2_check_descriptors",
718 "Inode table for group %d"
719 " not in group (block %lu)!",
720 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
721 return 0;
722 }
723 }
724 return 1;
725 }
726
727 /*
728 * Maximal file size. There is a direct, and {,double-,triple-}indirect
729 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
730 * We need to be 1 filesystem block less than the 2^32 sector limit.
731 */
ext2_max_size(int bits)732 static loff_t ext2_max_size(int bits)
733 {
734 loff_t res = EXT2_NDIR_BLOCKS;
735 int meta_blocks;
736 unsigned int upper_limit;
737 unsigned int ppb = 1 << (bits-2);
738
739 /* This is calculated to be the largest file size for a
740 * dense, file such that the total number of
741 * sectors in the file, including data and all indirect blocks,
742 * does not exceed 2^32 -1
743 * __u32 i_blocks representing the total number of
744 * 512 bytes blocks of the file
745 */
746 upper_limit = (1LL << 32) - 1;
747
748 /* total blocks in file system block size */
749 upper_limit >>= (bits - 9);
750
751 /* Compute how many blocks we can address by block tree */
752 res += 1LL << (bits-2);
753 res += 1LL << (2*(bits-2));
754 res += 1LL << (3*(bits-2));
755 /* Compute how many metadata blocks are needed */
756 meta_blocks = 1;
757 meta_blocks += 1 + ppb;
758 meta_blocks += 1 + ppb + ppb * ppb;
759 /* Does block tree limit file size? */
760 if (res + meta_blocks <= upper_limit)
761 goto check_lfs;
762
763 res = upper_limit;
764 /* How many metadata blocks are needed for addressing upper_limit? */
765 upper_limit -= EXT2_NDIR_BLOCKS;
766 /* indirect blocks */
767 meta_blocks = 1;
768 upper_limit -= ppb;
769 /* double indirect blocks */
770 if (upper_limit < ppb * ppb) {
771 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
772 res -= meta_blocks;
773 goto check_lfs;
774 }
775 meta_blocks += 1 + ppb;
776 upper_limit -= ppb * ppb;
777 /* tripple indirect blocks for the rest */
778 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
779 DIV_ROUND_UP(upper_limit, ppb*ppb);
780 res -= meta_blocks;
781 check_lfs:
782 res <<= bits;
783 if (res > MAX_LFS_FILESIZE)
784 res = MAX_LFS_FILESIZE;
785
786 return res;
787 }
788
descriptor_loc(struct super_block * sb,unsigned long logic_sb_block,int nr)789 static unsigned long descriptor_loc(struct super_block *sb,
790 unsigned long logic_sb_block,
791 int nr)
792 {
793 struct ext2_sb_info *sbi = EXT2_SB(sb);
794 unsigned long bg, first_meta_bg;
795
796 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
797
798 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
799 nr < first_meta_bg)
800 return (logic_sb_block + nr + 1);
801 bg = sbi->s_desc_per_block * nr;
802
803 return ext2_group_first_block_no(sb, bg) + ext2_bg_has_super(sb, bg);
804 }
805
ext2_fill_super(struct super_block * sb,void * data,int silent)806 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
807 {
808 struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
809 struct buffer_head * bh;
810 struct ext2_sb_info * sbi;
811 struct ext2_super_block * es;
812 struct inode *root;
813 unsigned long block;
814 unsigned long sb_block = get_sb_block(&data);
815 unsigned long logic_sb_block;
816 unsigned long offset = 0;
817 unsigned long def_mount_opts;
818 long ret = -ENOMEM;
819 int blocksize = BLOCK_SIZE;
820 int db_count;
821 int i, j;
822 __le32 features;
823 int err;
824 struct ext2_mount_options opts;
825
826 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
827 if (!sbi)
828 goto failed;
829
830 sbi->s_blockgroup_lock =
831 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
832 if (!sbi->s_blockgroup_lock) {
833 kfree(sbi);
834 goto failed;
835 }
836 sb->s_fs_info = sbi;
837 sbi->s_sb_block = sb_block;
838 sbi->s_daxdev = dax_dev;
839
840 spin_lock_init(&sbi->s_lock);
841 ret = -EINVAL;
842
843 /*
844 * See what the current blocksize for the device is, and
845 * use that as the blocksize. Otherwise (or if the blocksize
846 * is smaller than the default) use the default.
847 * This is important for devices that have a hardware
848 * sectorsize that is larger than the default.
849 */
850 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
851 if (!blocksize) {
852 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
853 goto failed_sbi;
854 }
855
856 /*
857 * If the superblock doesn't start on a hardware sector boundary,
858 * calculate the offset.
859 */
860 if (blocksize != BLOCK_SIZE) {
861 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
862 offset = (sb_block*BLOCK_SIZE) % blocksize;
863 } else {
864 logic_sb_block = sb_block;
865 }
866
867 if (!(bh = sb_bread(sb, logic_sb_block))) {
868 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
869 goto failed_sbi;
870 }
871 /*
872 * Note: s_es must be initialized as soon as possible because
873 * some ext2 macro-instructions depend on its value
874 */
875 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
876 sbi->s_es = es;
877 sb->s_magic = le16_to_cpu(es->s_magic);
878
879 if (sb->s_magic != EXT2_SUPER_MAGIC)
880 goto cantfind_ext2;
881
882 opts.s_mount_opt = 0;
883 /* Set defaults before we parse the mount options */
884 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
885 if (def_mount_opts & EXT2_DEFM_DEBUG)
886 set_opt(opts.s_mount_opt, DEBUG);
887 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
888 set_opt(opts.s_mount_opt, GRPID);
889 if (def_mount_opts & EXT2_DEFM_UID16)
890 set_opt(opts.s_mount_opt, NO_UID32);
891 #ifdef CONFIG_EXT2_FS_XATTR
892 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
893 set_opt(opts.s_mount_opt, XATTR_USER);
894 #endif
895 #ifdef CONFIG_EXT2_FS_POSIX_ACL
896 if (def_mount_opts & EXT2_DEFM_ACL)
897 set_opt(opts.s_mount_opt, POSIX_ACL);
898 #endif
899
900 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
901 set_opt(opts.s_mount_opt, ERRORS_PANIC);
902 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
903 set_opt(opts.s_mount_opt, ERRORS_CONT);
904 else
905 set_opt(opts.s_mount_opt, ERRORS_RO);
906
907 opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
908 opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
909
910 set_opt(opts.s_mount_opt, RESERVATION);
911
912 if (!parse_options((char *) data, sb, &opts))
913 goto failed_mount;
914
915 sbi->s_mount_opt = opts.s_mount_opt;
916 sbi->s_resuid = opts.s_resuid;
917 sbi->s_resgid = opts.s_resgid;
918
919 sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
920 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
921 sb->s_iflags |= SB_I_CGROUPWB;
922
923 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
924 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
925 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
926 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
927 ext2_msg(sb, KERN_WARNING,
928 "warning: feature flags set on rev 0 fs, "
929 "running e2fsck is recommended");
930 /*
931 * Check feature flags regardless of the revision level, since we
932 * previously didn't change the revision level when setting the flags,
933 * so there is a chance incompat flags are set on a rev 0 filesystem.
934 */
935 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
936 if (features) {
937 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
938 "unsupported optional features (%x)",
939 le32_to_cpu(features));
940 goto failed_mount;
941 }
942 if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
943 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
944 "unsupported optional features (%x)",
945 le32_to_cpu(features));
946 goto failed_mount;
947 }
948
949 if (le32_to_cpu(es->s_log_block_size) >
950 (EXT2_MAX_BLOCK_LOG_SIZE - BLOCK_SIZE_BITS)) {
951 ext2_msg(sb, KERN_ERR,
952 "Invalid log block size: %u",
953 le32_to_cpu(es->s_log_block_size));
954 goto failed_mount;
955 }
956 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
957
958 if (test_opt(sb, DAX)) {
959 if (!dax_supported(dax_dev, sb->s_bdev, blocksize, 0,
960 bdev_nr_sectors(sb->s_bdev))) {
961 ext2_msg(sb, KERN_ERR,
962 "DAX unsupported by block device. Turning off DAX.");
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 if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
1054 sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1055 ext2_msg(sb, KERN_ERR,
1056 "error: invalid #inodes per group: %lu",
1057 sbi->s_inodes_per_group);
1058 goto failed_mount;
1059 }
1060
1061 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1062 goto cantfind_ext2;
1063 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1064 le32_to_cpu(es->s_first_data_block) - 1)
1065 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1066 if ((u64)sbi->s_groups_count * sbi->s_inodes_per_group !=
1067 le32_to_cpu(es->s_inodes_count)) {
1068 ext2_msg(sb, KERN_ERR, "error: invalid #inodes: %u vs computed %llu",
1069 le32_to_cpu(es->s_inodes_count),
1070 (u64)sbi->s_groups_count * sbi->s_inodes_per_group);
1071 goto failed_mount;
1072 }
1073 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1074 EXT2_DESC_PER_BLOCK(sb);
1075 sbi->s_group_desc = kvmalloc_array(db_count,
1076 sizeof(struct buffer_head *),
1077 GFP_KERNEL);
1078 if (sbi->s_group_desc == NULL) {
1079 ret = -ENOMEM;
1080 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1081 goto failed_mount;
1082 }
1083 bgl_lock_init(sbi->s_blockgroup_lock);
1084 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1085 if (!sbi->s_debts) {
1086 ret = -ENOMEM;
1087 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1088 goto failed_mount_group_desc;
1089 }
1090 for (i = 0; i < db_count; i++) {
1091 block = descriptor_loc(sb, logic_sb_block, i);
1092 sbi->s_group_desc[i] = sb_bread(sb, block);
1093 if (!sbi->s_group_desc[i]) {
1094 for (j = 0; j < i; j++)
1095 brelse (sbi->s_group_desc[j]);
1096 ext2_msg(sb, KERN_ERR,
1097 "error: unable to read group descriptors");
1098 goto failed_mount_group_desc;
1099 }
1100 }
1101 if (!ext2_check_descriptors (sb)) {
1102 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1103 goto failed_mount2;
1104 }
1105 sbi->s_gdb_count = db_count;
1106 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1107 spin_lock_init(&sbi->s_next_gen_lock);
1108
1109 /* per filesystem reservation list head & lock */
1110 spin_lock_init(&sbi->s_rsv_window_lock);
1111 sbi->s_rsv_window_root = RB_ROOT;
1112 /*
1113 * Add a single, static dummy reservation to the start of the
1114 * reservation window list --- it gives us a placeholder for
1115 * append-at-start-of-list which makes the allocation logic
1116 * _much_ simpler.
1117 */
1118 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1119 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1120 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1121 sbi->s_rsv_window_head.rsv_goal_size = 0;
1122 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1123
1124 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1125 ext2_count_free_blocks(sb), GFP_KERNEL);
1126 if (!err) {
1127 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1128 ext2_count_free_inodes(sb), GFP_KERNEL);
1129 }
1130 if (!err) {
1131 err = percpu_counter_init(&sbi->s_dirs_counter,
1132 ext2_count_dirs(sb), GFP_KERNEL);
1133 }
1134 if (err) {
1135 ret = err;
1136 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1137 goto failed_mount3;
1138 }
1139
1140 #ifdef CONFIG_EXT2_FS_XATTR
1141 sbi->s_ea_block_cache = ext2_xattr_create_cache();
1142 if (!sbi->s_ea_block_cache) {
1143 ret = -ENOMEM;
1144 ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1145 goto failed_mount3;
1146 }
1147 #endif
1148 /*
1149 * set up enough so that it can read an inode
1150 */
1151 sb->s_op = &ext2_sops;
1152 sb->s_export_op = &ext2_export_ops;
1153 sb->s_xattr = ext2_xattr_handlers;
1154
1155 #ifdef CONFIG_QUOTA
1156 sb->dq_op = &dquot_operations;
1157 sb->s_qcop = &ext2_quotactl_ops;
1158 sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1159 #endif
1160
1161 root = ext2_iget(sb, EXT2_ROOT_INO);
1162 if (IS_ERR(root)) {
1163 ret = PTR_ERR(root);
1164 goto failed_mount3;
1165 }
1166 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1167 iput(root);
1168 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1169 goto failed_mount3;
1170 }
1171
1172 sb->s_root = d_make_root(root);
1173 if (!sb->s_root) {
1174 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1175 ret = -ENOMEM;
1176 goto failed_mount3;
1177 }
1178 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1179 ext2_msg(sb, KERN_WARNING,
1180 "warning: mounting ext3 filesystem as ext2");
1181 if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1182 sb->s_flags |= SB_RDONLY;
1183 ext2_write_super(sb);
1184 return 0;
1185
1186 cantfind_ext2:
1187 if (!silent)
1188 ext2_msg(sb, KERN_ERR,
1189 "error: can't find an ext2 filesystem on dev %s.",
1190 sb->s_id);
1191 goto failed_mount;
1192 failed_mount3:
1193 ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1194 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1195 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1196 percpu_counter_destroy(&sbi->s_dirs_counter);
1197 failed_mount2:
1198 for (i = 0; i < db_count; i++)
1199 brelse(sbi->s_group_desc[i]);
1200 failed_mount_group_desc:
1201 kvfree(sbi->s_group_desc);
1202 kfree(sbi->s_debts);
1203 failed_mount:
1204 brelse(bh);
1205 failed_sbi:
1206 sb->s_fs_info = NULL;
1207 kfree(sbi->s_blockgroup_lock);
1208 kfree(sbi);
1209 failed:
1210 fs_put_dax(dax_dev);
1211 return ret;
1212 }
1213
ext2_clear_super_error(struct super_block * sb)1214 static void ext2_clear_super_error(struct super_block *sb)
1215 {
1216 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1217
1218 if (buffer_write_io_error(sbh)) {
1219 /*
1220 * Oh, dear. A previous attempt to write the
1221 * superblock failed. This could happen because the
1222 * USB device was yanked out. Or it could happen to
1223 * be a transient write error and maybe the block will
1224 * be remapped. Nothing we can do but to retry the
1225 * write and hope for the best.
1226 */
1227 ext2_msg(sb, KERN_ERR,
1228 "previous I/O error to superblock detected");
1229 clear_buffer_write_io_error(sbh);
1230 set_buffer_uptodate(sbh);
1231 }
1232 }
1233
ext2_sync_super(struct super_block * sb,struct ext2_super_block * es,int wait)1234 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1235 int wait)
1236 {
1237 ext2_clear_super_error(sb);
1238 spin_lock(&EXT2_SB(sb)->s_lock);
1239 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1240 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1241 es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1242 /* unlock before we do IO */
1243 spin_unlock(&EXT2_SB(sb)->s_lock);
1244 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1245 if (wait)
1246 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1247 }
1248
1249 /*
1250 * In the second extended file system, it is not necessary to
1251 * write the super block since we use a mapping of the
1252 * disk super block in a buffer.
1253 *
1254 * However, this function is still used to set the fs valid
1255 * flags to 0. We need to set this flag to 0 since the fs
1256 * may have been checked while mounted and e2fsck may have
1257 * set s_state to EXT2_VALID_FS after some corrections.
1258 */
ext2_sync_fs(struct super_block * sb,int wait)1259 static int ext2_sync_fs(struct super_block *sb, int wait)
1260 {
1261 struct ext2_sb_info *sbi = EXT2_SB(sb);
1262 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1263
1264 /*
1265 * Write quota structures to quota file, sync_blockdev() will write
1266 * them to disk later
1267 */
1268 dquot_writeback_dquots(sb, -1);
1269
1270 spin_lock(&sbi->s_lock);
1271 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1272 ext2_debug("setting valid to 0\n");
1273 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1274 }
1275 spin_unlock(&sbi->s_lock);
1276 ext2_sync_super(sb, es, wait);
1277 return 0;
1278 }
1279
ext2_freeze(struct super_block * sb)1280 static int ext2_freeze(struct super_block *sb)
1281 {
1282 struct ext2_sb_info *sbi = EXT2_SB(sb);
1283
1284 /*
1285 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1286 * because we have unattached inodes and thus filesystem is not fully
1287 * consistent.
1288 */
1289 if (atomic_long_read(&sb->s_remove_count)) {
1290 ext2_sync_fs(sb, 1);
1291 return 0;
1292 }
1293 /* Set EXT2_FS_VALID flag */
1294 spin_lock(&sbi->s_lock);
1295 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1296 spin_unlock(&sbi->s_lock);
1297 ext2_sync_super(sb, sbi->s_es, 1);
1298
1299 return 0;
1300 }
1301
ext2_unfreeze(struct super_block * sb)1302 static int ext2_unfreeze(struct super_block *sb)
1303 {
1304 /* Just write sb to clear EXT2_VALID_FS flag */
1305 ext2_write_super(sb);
1306
1307 return 0;
1308 }
1309
ext2_write_super(struct super_block * sb)1310 static void ext2_write_super(struct super_block *sb)
1311 {
1312 if (!sb_rdonly(sb))
1313 ext2_sync_fs(sb, 1);
1314 }
1315
ext2_remount(struct super_block * sb,int * flags,char * data)1316 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1317 {
1318 struct ext2_sb_info * sbi = EXT2_SB(sb);
1319 struct ext2_super_block * es;
1320 struct ext2_mount_options new_opts;
1321 int err;
1322
1323 sync_filesystem(sb);
1324
1325 spin_lock(&sbi->s_lock);
1326 new_opts.s_mount_opt = sbi->s_mount_opt;
1327 new_opts.s_resuid = sbi->s_resuid;
1328 new_opts.s_resgid = sbi->s_resgid;
1329 spin_unlock(&sbi->s_lock);
1330
1331 if (!parse_options(data, sb, &new_opts))
1332 return -EINVAL;
1333
1334 spin_lock(&sbi->s_lock);
1335 es = sbi->s_es;
1336 if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1337 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1338 "dax flag with busy inodes while remounting");
1339 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1340 }
1341 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1342 goto out_set;
1343 if (*flags & SB_RDONLY) {
1344 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1345 !(sbi->s_mount_state & EXT2_VALID_FS))
1346 goto out_set;
1347
1348 /*
1349 * OK, we are remounting a valid rw partition rdonly, so set
1350 * the rdonly flag and then mark the partition as valid again.
1351 */
1352 es->s_state = cpu_to_le16(sbi->s_mount_state);
1353 es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1354 spin_unlock(&sbi->s_lock);
1355
1356 err = dquot_suspend(sb, -1);
1357 if (err < 0)
1358 return err;
1359
1360 ext2_sync_super(sb, es, 1);
1361 } else {
1362 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1363 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1364 if (ret) {
1365 spin_unlock(&sbi->s_lock);
1366 ext2_msg(sb, KERN_WARNING,
1367 "warning: couldn't remount RDWR because of "
1368 "unsupported optional features (%x).",
1369 le32_to_cpu(ret));
1370 return -EROFS;
1371 }
1372 /*
1373 * Mounting a RDONLY partition read-write, so reread and
1374 * store the current valid flag. (It may have been changed
1375 * by e2fsck since we originally mounted the partition.)
1376 */
1377 sbi->s_mount_state = le16_to_cpu(es->s_state);
1378 if (!ext2_setup_super (sb, es, 0))
1379 sb->s_flags &= ~SB_RDONLY;
1380 spin_unlock(&sbi->s_lock);
1381
1382 ext2_write_super(sb);
1383
1384 dquot_resume(sb, -1);
1385 }
1386
1387 spin_lock(&sbi->s_lock);
1388 out_set:
1389 sbi->s_mount_opt = new_opts.s_mount_opt;
1390 sbi->s_resuid = new_opts.s_resuid;
1391 sbi->s_resgid = new_opts.s_resgid;
1392 sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1393 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
1394 spin_unlock(&sbi->s_lock);
1395
1396 return 0;
1397 }
1398
ext2_statfs(struct dentry * dentry,struct kstatfs * buf)1399 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1400 {
1401 struct super_block *sb = dentry->d_sb;
1402 struct ext2_sb_info *sbi = EXT2_SB(sb);
1403 struct ext2_super_block *es = sbi->s_es;
1404
1405 spin_lock(&sbi->s_lock);
1406
1407 if (test_opt (sb, MINIX_DF))
1408 sbi->s_overhead_last = 0;
1409 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1410 unsigned long i, overhead = 0;
1411 smp_rmb();
1412
1413 /*
1414 * Compute the overhead (FS structures). This is constant
1415 * for a given filesystem unless the number of block groups
1416 * changes so we cache the previous value until it does.
1417 */
1418
1419 /*
1420 * All of the blocks before first_data_block are
1421 * overhead
1422 */
1423 overhead = le32_to_cpu(es->s_first_data_block);
1424
1425 /*
1426 * Add the overhead attributed to the superblock and
1427 * block group descriptors. If the sparse superblocks
1428 * feature is turned on, then not all groups have this.
1429 */
1430 for (i = 0; i < sbi->s_groups_count; i++)
1431 overhead += ext2_bg_has_super(sb, i) +
1432 ext2_bg_num_gdb(sb, i);
1433
1434 /*
1435 * Every block group has an inode bitmap, a block
1436 * bitmap, and an inode table.
1437 */
1438 overhead += (sbi->s_groups_count *
1439 (2 + sbi->s_itb_per_group));
1440 sbi->s_overhead_last = overhead;
1441 smp_wmb();
1442 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1443 }
1444
1445 buf->f_type = EXT2_SUPER_MAGIC;
1446 buf->f_bsize = sb->s_blocksize;
1447 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1448 buf->f_bfree = ext2_count_free_blocks(sb);
1449 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1450 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1451 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1452 buf->f_bavail = 0;
1453 buf->f_files = le32_to_cpu(es->s_inodes_count);
1454 buf->f_ffree = ext2_count_free_inodes(sb);
1455 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1456 buf->f_namelen = EXT2_NAME_LEN;
1457 buf->f_fsid = uuid_to_fsid(es->s_uuid);
1458 spin_unlock(&sbi->s_lock);
1459 return 0;
1460 }
1461
ext2_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)1462 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1463 int flags, const char *dev_name, void *data)
1464 {
1465 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1466 }
1467
1468 #ifdef CONFIG_QUOTA
1469
1470 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1471 * acquiring the locks... As quota files are never truncated and quota code
1472 * itself serializes the operations (and no one else should touch the files)
1473 * 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)1474 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1475 size_t len, loff_t off)
1476 {
1477 struct inode *inode = sb_dqopt(sb)->files[type];
1478 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1479 int err = 0;
1480 int offset = off & (sb->s_blocksize - 1);
1481 int tocopy;
1482 size_t toread;
1483 struct buffer_head tmp_bh;
1484 struct buffer_head *bh;
1485 loff_t i_size = i_size_read(inode);
1486
1487 if (off > i_size)
1488 return 0;
1489 if (off+len > i_size)
1490 len = i_size-off;
1491 toread = len;
1492 while (toread > 0) {
1493 tocopy = sb->s_blocksize - offset < toread ?
1494 sb->s_blocksize - offset : toread;
1495
1496 tmp_bh.b_state = 0;
1497 tmp_bh.b_size = sb->s_blocksize;
1498 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1499 if (err < 0)
1500 return err;
1501 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1502 memset(data, 0, tocopy);
1503 else {
1504 bh = sb_bread(sb, tmp_bh.b_blocknr);
1505 if (!bh)
1506 return -EIO;
1507 memcpy(data, bh->b_data+offset, tocopy);
1508 brelse(bh);
1509 }
1510 offset = 0;
1511 toread -= tocopy;
1512 data += tocopy;
1513 blk++;
1514 }
1515 return len;
1516 }
1517
1518 /* Write to quotafile */
ext2_quota_write(struct super_block * sb,int type,const char * data,size_t len,loff_t off)1519 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1520 const char *data, size_t len, loff_t off)
1521 {
1522 struct inode *inode = sb_dqopt(sb)->files[type];
1523 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1524 int err = 0;
1525 int offset = off & (sb->s_blocksize - 1);
1526 int tocopy;
1527 size_t towrite = len;
1528 struct buffer_head tmp_bh;
1529 struct buffer_head *bh;
1530
1531 while (towrite > 0) {
1532 tocopy = sb->s_blocksize - offset < towrite ?
1533 sb->s_blocksize - offset : towrite;
1534
1535 tmp_bh.b_state = 0;
1536 tmp_bh.b_size = sb->s_blocksize;
1537 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1538 if (err < 0)
1539 goto out;
1540 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1541 bh = sb_bread(sb, tmp_bh.b_blocknr);
1542 else
1543 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1544 if (unlikely(!bh)) {
1545 err = -EIO;
1546 goto out;
1547 }
1548 lock_buffer(bh);
1549 memcpy(bh->b_data+offset, data, tocopy);
1550 flush_dcache_page(bh->b_page);
1551 set_buffer_uptodate(bh);
1552 mark_buffer_dirty(bh);
1553 unlock_buffer(bh);
1554 brelse(bh);
1555 offset = 0;
1556 towrite -= tocopy;
1557 data += tocopy;
1558 blk++;
1559 }
1560 out:
1561 if (len == towrite)
1562 return err;
1563 if (inode->i_size < off+len-towrite)
1564 i_size_write(inode, off+len-towrite);
1565 inode_inc_iversion(inode);
1566 inode->i_mtime = inode->i_ctime = current_time(inode);
1567 mark_inode_dirty(inode);
1568 return len - towrite;
1569 }
1570
ext2_quota_on(struct super_block * sb,int type,int format_id,const struct path * path)1571 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1572 const struct path *path)
1573 {
1574 int err;
1575 struct inode *inode;
1576
1577 err = dquot_quota_on(sb, type, format_id, path);
1578 if (err)
1579 return err;
1580
1581 inode = d_inode(path->dentry);
1582 inode_lock(inode);
1583 EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1584 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1585 S_NOATIME | S_IMMUTABLE);
1586 inode_unlock(inode);
1587 mark_inode_dirty(inode);
1588
1589 return 0;
1590 }
1591
ext2_quota_off(struct super_block * sb,int type)1592 static int ext2_quota_off(struct super_block *sb, int type)
1593 {
1594 struct inode *inode = sb_dqopt(sb)->files[type];
1595 int err;
1596
1597 if (!inode || !igrab(inode))
1598 goto out;
1599
1600 err = dquot_quota_off(sb, type);
1601 if (err)
1602 goto out_put;
1603
1604 inode_lock(inode);
1605 EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1606 inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1607 inode_unlock(inode);
1608 mark_inode_dirty(inode);
1609 out_put:
1610 iput(inode);
1611 return err;
1612 out:
1613 return dquot_quota_off(sb, type);
1614 }
1615
1616 #endif
1617
1618 static struct file_system_type ext2_fs_type = {
1619 .owner = THIS_MODULE,
1620 .name = "ext2",
1621 .mount = ext2_mount,
1622 .kill_sb = kill_block_super,
1623 .fs_flags = FS_REQUIRES_DEV,
1624 };
1625 MODULE_ALIAS_FS("ext2");
1626
init_ext2_fs(void)1627 static int __init init_ext2_fs(void)
1628 {
1629 int err;
1630
1631 err = init_inodecache();
1632 if (err)
1633 return err;
1634 err = register_filesystem(&ext2_fs_type);
1635 if (err)
1636 goto out;
1637 return 0;
1638 out:
1639 destroy_inodecache();
1640 return err;
1641 }
1642
exit_ext2_fs(void)1643 static void __exit exit_ext2_fs(void)
1644 {
1645 unregister_filesystem(&ext2_fs_type);
1646 destroy_inodecache();
1647 }
1648
1649 MODULE_AUTHOR("Remy Card and others");
1650 MODULE_DESCRIPTION("Second Extended Filesystem");
1651 MODULE_LICENSE("GPL");
1652 MODULE_IMPORT_NS(ANDROID_GKI_VFS_EXPORT_ONLY);
1653 module_init(init_ext2_fs)
1654 module_exit(exit_ext2_fs)
1655