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 kfree(sbi->s_group_desc);
167 kfree(sbi->s_debts);
168 percpu_counter_destroy(&sbi->s_freeblocks_counter);
169 percpu_counter_destroy(&sbi->s_freeinodes_counter);
170 percpu_counter_destroy(&sbi->s_dirs_counter);
171 brelse (sbi->s_sbh);
172 sb->s_fs_info = NULL;
173 kfree(sbi->s_blockgroup_lock);
174 fs_put_dax(sbi->s_daxdev);
175 kfree(sbi);
176 }
177
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 #ifdef CONFIG_FS_DAX
210 init_rwsem(&ei->dax_sem);
211 #endif
212 inode_init_once(&ei->vfs_inode);
213 }
214
init_inodecache(void)215 static int __init init_inodecache(void)
216 {
217 ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
218 sizeof(struct ext2_inode_info), 0,
219 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
220 SLAB_ACCOUNT),
221 offsetof(struct ext2_inode_info, i_data),
222 sizeof_field(struct ext2_inode_info, i_data),
223 init_once);
224 if (ext2_inode_cachep == NULL)
225 return -ENOMEM;
226 return 0;
227 }
228
destroy_inodecache(void)229 static void destroy_inodecache(void)
230 {
231 /*
232 * Make sure all delayed rcu free inodes are flushed before we
233 * destroy cache.
234 */
235 rcu_barrier();
236 kmem_cache_destroy(ext2_inode_cachep);
237 }
238
ext2_show_options(struct seq_file * seq,struct dentry * root)239 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
240 {
241 struct super_block *sb = root->d_sb;
242 struct ext2_sb_info *sbi = EXT2_SB(sb);
243 struct ext2_super_block *es = sbi->s_es;
244 unsigned long def_mount_opts;
245
246 spin_lock(&sbi->s_lock);
247 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
248
249 if (sbi->s_sb_block != 1)
250 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
251 if (test_opt(sb, MINIX_DF))
252 seq_puts(seq, ",minixdf");
253 if (test_opt(sb, GRPID))
254 seq_puts(seq, ",grpid");
255 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
256 seq_puts(seq, ",nogrpid");
257 if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
258 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
259 seq_printf(seq, ",resuid=%u",
260 from_kuid_munged(&init_user_ns, sbi->s_resuid));
261 }
262 if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
263 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
264 seq_printf(seq, ",resgid=%u",
265 from_kgid_munged(&init_user_ns, sbi->s_resgid));
266 }
267 if (test_opt(sb, ERRORS_RO)) {
268 int def_errors = le16_to_cpu(es->s_errors);
269
270 if (def_errors == EXT2_ERRORS_PANIC ||
271 def_errors == EXT2_ERRORS_CONTINUE) {
272 seq_puts(seq, ",errors=remount-ro");
273 }
274 }
275 if (test_opt(sb, ERRORS_CONT))
276 seq_puts(seq, ",errors=continue");
277 if (test_opt(sb, ERRORS_PANIC))
278 seq_puts(seq, ",errors=panic");
279 if (test_opt(sb, NO_UID32))
280 seq_puts(seq, ",nouid32");
281 if (test_opt(sb, DEBUG))
282 seq_puts(seq, ",debug");
283 if (test_opt(sb, OLDALLOC))
284 seq_puts(seq, ",oldalloc");
285
286 #ifdef CONFIG_EXT2_FS_XATTR
287 if (test_opt(sb, XATTR_USER))
288 seq_puts(seq, ",user_xattr");
289 if (!test_opt(sb, XATTR_USER) &&
290 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
291 seq_puts(seq, ",nouser_xattr");
292 }
293 #endif
294
295 #ifdef CONFIG_EXT2_FS_POSIX_ACL
296 if (test_opt(sb, POSIX_ACL))
297 seq_puts(seq, ",acl");
298 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
299 seq_puts(seq, ",noacl");
300 #endif
301
302 if (test_opt(sb, NOBH))
303 seq_puts(seq, ",nobh");
304
305 if (test_opt(sb, USRQUOTA))
306 seq_puts(seq, ",usrquota");
307
308 if (test_opt(sb, GRPQUOTA))
309 seq_puts(seq, ",grpquota");
310
311 if (test_opt(sb, XIP))
312 seq_puts(seq, ",xip");
313
314 if (test_opt(sb, DAX))
315 seq_puts(seq, ",dax");
316
317 if (!test_opt(sb, RESERVATION))
318 seq_puts(seq, ",noreservation");
319
320 spin_unlock(&sbi->s_lock);
321 return 0;
322 }
323
324 #ifdef CONFIG_QUOTA
325 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
326 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
327 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
328 const struct path *path);
ext2_get_dquots(struct inode * inode)329 static struct dquot **ext2_get_dquots(struct inode *inode)
330 {
331 return EXT2_I(inode)->i_dquot;
332 }
333
334 static const struct quotactl_ops ext2_quotactl_ops = {
335 .quota_on = ext2_quota_on,
336 .quota_off = ext2_quota_off,
337 .quota_sync = dquot_quota_sync,
338 .get_state = dquot_get_state,
339 .set_info = dquot_set_dqinfo,
340 .get_dqblk = dquot_get_dqblk,
341 .set_dqblk = dquot_set_dqblk,
342 .get_nextdqblk = dquot_get_next_dqblk,
343 };
344 #endif
345
346 static const struct super_operations ext2_sops = {
347 .alloc_inode = ext2_alloc_inode,
348 .free_inode = ext2_free_in_core_inode,
349 .write_inode = ext2_write_inode,
350 .evict_inode = ext2_evict_inode,
351 .put_super = ext2_put_super,
352 .sync_fs = ext2_sync_fs,
353 .freeze_fs = ext2_freeze,
354 .unfreeze_fs = ext2_unfreeze,
355 .statfs = ext2_statfs,
356 .remount_fs = ext2_remount,
357 .show_options = ext2_show_options,
358 #ifdef CONFIG_QUOTA
359 .quota_read = ext2_quota_read,
360 .quota_write = ext2_quota_write,
361 .get_dquots = ext2_get_dquots,
362 #endif
363 };
364
ext2_nfs_get_inode(struct super_block * sb,u64 ino,u32 generation)365 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
366 u64 ino, u32 generation)
367 {
368 struct inode *inode;
369
370 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
371 return ERR_PTR(-ESTALE);
372 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
373 return ERR_PTR(-ESTALE);
374
375 /*
376 * ext2_iget isn't quite right if the inode is currently unallocated!
377 * However ext2_iget currently does appropriate checks to handle stale
378 * inodes so everything is OK.
379 */
380 inode = ext2_iget(sb, ino);
381 if (IS_ERR(inode))
382 return ERR_CAST(inode);
383 if (generation && inode->i_generation != generation) {
384 /* we didn't find the right inode.. */
385 iput(inode);
386 return ERR_PTR(-ESTALE);
387 }
388 return inode;
389 }
390
ext2_fh_to_dentry(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)391 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
392 int fh_len, int fh_type)
393 {
394 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
395 ext2_nfs_get_inode);
396 }
397
ext2_fh_to_parent(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)398 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
399 int fh_len, int fh_type)
400 {
401 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
402 ext2_nfs_get_inode);
403 }
404
405 static const struct export_operations ext2_export_ops = {
406 .fh_to_dentry = ext2_fh_to_dentry,
407 .fh_to_parent = ext2_fh_to_parent,
408 .get_parent = ext2_get_parent,
409 };
410
get_sb_block(void ** data)411 static unsigned long get_sb_block(void **data)
412 {
413 unsigned long sb_block;
414 char *options = (char *) *data;
415
416 if (!options || strncmp(options, "sb=", 3) != 0)
417 return 1; /* Default location */
418 options += 3;
419 sb_block = simple_strtoul(options, &options, 0);
420 if (*options && *options != ',') {
421 printk("EXT2-fs: Invalid sb specification: %s\n",
422 (char *) *data);
423 return 1;
424 }
425 if (*options == ',')
426 options++;
427 *data = (void *) options;
428 return sb_block;
429 }
430
431 enum {
432 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
433 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
434 Opt_err_ro, Opt_nouid32, Opt_debug,
435 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
436 Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
437 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
438 };
439
440 static const match_table_t tokens = {
441 {Opt_bsd_df, "bsddf"},
442 {Opt_minix_df, "minixdf"},
443 {Opt_grpid, "grpid"},
444 {Opt_grpid, "bsdgroups"},
445 {Opt_nogrpid, "nogrpid"},
446 {Opt_nogrpid, "sysvgroups"},
447 {Opt_resgid, "resgid=%u"},
448 {Opt_resuid, "resuid=%u"},
449 {Opt_sb, "sb=%u"},
450 {Opt_err_cont, "errors=continue"},
451 {Opt_err_panic, "errors=panic"},
452 {Opt_err_ro, "errors=remount-ro"},
453 {Opt_nouid32, "nouid32"},
454 {Opt_debug, "debug"},
455 {Opt_oldalloc, "oldalloc"},
456 {Opt_orlov, "orlov"},
457 {Opt_nobh, "nobh"},
458 {Opt_user_xattr, "user_xattr"},
459 {Opt_nouser_xattr, "nouser_xattr"},
460 {Opt_acl, "acl"},
461 {Opt_noacl, "noacl"},
462 {Opt_xip, "xip"},
463 {Opt_dax, "dax"},
464 {Opt_grpquota, "grpquota"},
465 {Opt_ignore, "noquota"},
466 {Opt_quota, "quota"},
467 {Opt_usrquota, "usrquota"},
468 {Opt_reservation, "reservation"},
469 {Opt_noreservation, "noreservation"},
470 {Opt_err, NULL}
471 };
472
parse_options(char * options,struct super_block * sb,struct ext2_mount_options * opts)473 static int parse_options(char *options, struct super_block *sb,
474 struct ext2_mount_options *opts)
475 {
476 char *p;
477 substring_t args[MAX_OPT_ARGS];
478 int option;
479 kuid_t uid;
480 kgid_t gid;
481
482 if (!options)
483 return 1;
484
485 while ((p = strsep (&options, ",")) != NULL) {
486 int token;
487 if (!*p)
488 continue;
489
490 token = match_token(p, tokens, args);
491 switch (token) {
492 case Opt_bsd_df:
493 clear_opt (opts->s_mount_opt, MINIX_DF);
494 break;
495 case Opt_minix_df:
496 set_opt (opts->s_mount_opt, MINIX_DF);
497 break;
498 case Opt_grpid:
499 set_opt (opts->s_mount_opt, GRPID);
500 break;
501 case Opt_nogrpid:
502 clear_opt (opts->s_mount_opt, GRPID);
503 break;
504 case Opt_resuid:
505 if (match_int(&args[0], &option))
506 return 0;
507 uid = make_kuid(current_user_ns(), option);
508 if (!uid_valid(uid)) {
509 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
510 return 0;
511
512 }
513 opts->s_resuid = uid;
514 break;
515 case Opt_resgid:
516 if (match_int(&args[0], &option))
517 return 0;
518 gid = make_kgid(current_user_ns(), option);
519 if (!gid_valid(gid)) {
520 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
521 return 0;
522 }
523 opts->s_resgid = gid;
524 break;
525 case Opt_sb:
526 /* handled by get_sb_block() instead of here */
527 /* *sb_block = match_int(&args[0]); */
528 break;
529 case Opt_err_panic:
530 clear_opt (opts->s_mount_opt, ERRORS_CONT);
531 clear_opt (opts->s_mount_opt, ERRORS_RO);
532 set_opt (opts->s_mount_opt, ERRORS_PANIC);
533 break;
534 case Opt_err_ro:
535 clear_opt (opts->s_mount_opt, ERRORS_CONT);
536 clear_opt (opts->s_mount_opt, ERRORS_PANIC);
537 set_opt (opts->s_mount_opt, ERRORS_RO);
538 break;
539 case Opt_err_cont:
540 clear_opt (opts->s_mount_opt, ERRORS_RO);
541 clear_opt (opts->s_mount_opt, ERRORS_PANIC);
542 set_opt (opts->s_mount_opt, ERRORS_CONT);
543 break;
544 case Opt_nouid32:
545 set_opt (opts->s_mount_opt, NO_UID32);
546 break;
547 case Opt_debug:
548 set_opt (opts->s_mount_opt, DEBUG);
549 break;
550 case Opt_oldalloc:
551 set_opt (opts->s_mount_opt, OLDALLOC);
552 break;
553 case Opt_orlov:
554 clear_opt (opts->s_mount_opt, OLDALLOC);
555 break;
556 case Opt_nobh:
557 set_opt (opts->s_mount_opt, NOBH);
558 break;
559 #ifdef CONFIG_EXT2_FS_XATTR
560 case Opt_user_xattr:
561 set_opt (opts->s_mount_opt, XATTR_USER);
562 break;
563 case Opt_nouser_xattr:
564 clear_opt (opts->s_mount_opt, XATTR_USER);
565 break;
566 #else
567 case Opt_user_xattr:
568 case Opt_nouser_xattr:
569 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
570 "not supported");
571 break;
572 #endif
573 #ifdef CONFIG_EXT2_FS_POSIX_ACL
574 case Opt_acl:
575 set_opt(opts->s_mount_opt, POSIX_ACL);
576 break;
577 case Opt_noacl:
578 clear_opt(opts->s_mount_opt, POSIX_ACL);
579 break;
580 #else
581 case Opt_acl:
582 case Opt_noacl:
583 ext2_msg(sb, KERN_INFO,
584 "(no)acl options not supported");
585 break;
586 #endif
587 case Opt_xip:
588 ext2_msg(sb, KERN_INFO, "use dax instead of xip");
589 set_opt(opts->s_mount_opt, XIP);
590 fallthrough;
591 case Opt_dax:
592 #ifdef CONFIG_FS_DAX
593 ext2_msg(sb, KERN_WARNING,
594 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
595 set_opt(opts->s_mount_opt, DAX);
596 #else
597 ext2_msg(sb, KERN_INFO, "dax option not supported");
598 #endif
599 break;
600
601 #if defined(CONFIG_QUOTA)
602 case Opt_quota:
603 case Opt_usrquota:
604 set_opt(opts->s_mount_opt, USRQUOTA);
605 break;
606
607 case Opt_grpquota:
608 set_opt(opts->s_mount_opt, GRPQUOTA);
609 break;
610 #else
611 case Opt_quota:
612 case Opt_usrquota:
613 case Opt_grpquota:
614 ext2_msg(sb, KERN_INFO,
615 "quota operations not supported");
616 break;
617 #endif
618
619 case Opt_reservation:
620 set_opt(opts->s_mount_opt, RESERVATION);
621 ext2_msg(sb, KERN_INFO, "reservations ON");
622 break;
623 case Opt_noreservation:
624 clear_opt(opts->s_mount_opt, RESERVATION);
625 ext2_msg(sb, KERN_INFO, "reservations OFF");
626 break;
627 case Opt_ignore:
628 break;
629 default:
630 return 0;
631 }
632 }
633 return 1;
634 }
635
ext2_setup_super(struct super_block * sb,struct ext2_super_block * es,int read_only)636 static int ext2_setup_super (struct super_block * sb,
637 struct ext2_super_block * es,
638 int read_only)
639 {
640 int res = 0;
641 struct ext2_sb_info *sbi = EXT2_SB(sb);
642
643 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
644 ext2_msg(sb, KERN_ERR,
645 "error: revision level too high, "
646 "forcing read-only mode");
647 res = SB_RDONLY;
648 }
649 if (read_only)
650 return res;
651 if (!(sbi->s_mount_state & EXT2_VALID_FS))
652 ext2_msg(sb, KERN_WARNING,
653 "warning: mounting unchecked fs, "
654 "running e2fsck is recommended");
655 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
656 ext2_msg(sb, KERN_WARNING,
657 "warning: mounting fs with errors, "
658 "running e2fsck is recommended");
659 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
660 le16_to_cpu(es->s_mnt_count) >=
661 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
662 ext2_msg(sb, KERN_WARNING,
663 "warning: maximal mount count reached, "
664 "running e2fsck is recommended");
665 else if (le32_to_cpu(es->s_checkinterval) &&
666 (le32_to_cpu(es->s_lastcheck) +
667 le32_to_cpu(es->s_checkinterval) <=
668 ktime_get_real_seconds()))
669 ext2_msg(sb, KERN_WARNING,
670 "warning: checktime reached, "
671 "running e2fsck is recommended");
672 if (!le16_to_cpu(es->s_max_mnt_count))
673 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
674 le16_add_cpu(&es->s_mnt_count, 1);
675 if (test_opt (sb, DEBUG))
676 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
677 "bpg=%lu, ipg=%lu, mo=%04lx]",
678 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
679 sbi->s_frag_size,
680 sbi->s_groups_count,
681 EXT2_BLOCKS_PER_GROUP(sb),
682 EXT2_INODES_PER_GROUP(sb),
683 sbi->s_mount_opt);
684 return res;
685 }
686
ext2_check_descriptors(struct super_block * sb)687 static int ext2_check_descriptors(struct super_block *sb)
688 {
689 int i;
690 struct ext2_sb_info *sbi = EXT2_SB(sb);
691
692 ext2_debug ("Checking group descriptors");
693
694 for (i = 0; i < sbi->s_groups_count; i++) {
695 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
696 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
697 ext2_fsblk_t last_block = ext2_group_last_block_no(sb, i);
698
699 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
700 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
701 {
702 ext2_error (sb, "ext2_check_descriptors",
703 "Block bitmap for group %d"
704 " not in group (block %lu)!",
705 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
706 return 0;
707 }
708 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
709 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
710 {
711 ext2_error (sb, "ext2_check_descriptors",
712 "Inode bitmap for group %d"
713 " not in group (block %lu)!",
714 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
715 return 0;
716 }
717 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
718 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
719 last_block)
720 {
721 ext2_error (sb, "ext2_check_descriptors",
722 "Inode table for group %d"
723 " not in group (block %lu)!",
724 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
725 return 0;
726 }
727 }
728 return 1;
729 }
730
731 /*
732 * Maximal file size. There is a direct, and {,double-,triple-}indirect
733 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
734 * We need to be 1 filesystem block less than the 2^32 sector limit.
735 */
ext2_max_size(int bits)736 static loff_t ext2_max_size(int bits)
737 {
738 loff_t res = EXT2_NDIR_BLOCKS;
739 int meta_blocks;
740 unsigned int upper_limit;
741 unsigned int ppb = 1 << (bits-2);
742
743 /* This is calculated to be the largest file size for a
744 * dense, file such that the total number of
745 * sectors in the file, including data and all indirect blocks,
746 * does not exceed 2^32 -1
747 * __u32 i_blocks representing the total number of
748 * 512 bytes blocks of the file
749 */
750 upper_limit = (1LL << 32) - 1;
751
752 /* total blocks in file system block size */
753 upper_limit >>= (bits - 9);
754
755 /* Compute how many blocks we can address by block tree */
756 res += 1LL << (bits-2);
757 res += 1LL << (2*(bits-2));
758 res += 1LL << (3*(bits-2));
759 /* Does block tree limit file size? */
760 if (res < 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 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
950
951 if (test_opt(sb, DAX)) {
952 if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
953 ext2_msg(sb, KERN_ERR,
954 "DAX unsupported by block device. Turning off DAX.");
955 clear_opt(sbi->s_mount_opt, DAX);
956 }
957 }
958
959 /* If the blocksize doesn't match, re-read the thing.. */
960 if (sb->s_blocksize != blocksize) {
961 brelse(bh);
962
963 if (!sb_set_blocksize(sb, blocksize)) {
964 ext2_msg(sb, KERN_ERR,
965 "error: bad blocksize %d", blocksize);
966 goto failed_sbi;
967 }
968
969 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
970 offset = (sb_block*BLOCK_SIZE) % blocksize;
971 bh = sb_bread(sb, logic_sb_block);
972 if(!bh) {
973 ext2_msg(sb, KERN_ERR, "error: couldn't read"
974 "superblock on 2nd try");
975 goto failed_sbi;
976 }
977 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
978 sbi->s_es = es;
979 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
980 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
981 goto failed_mount;
982 }
983 }
984
985 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
986 sb->s_max_links = EXT2_LINK_MAX;
987 sb->s_time_min = S32_MIN;
988 sb->s_time_max = S32_MAX;
989
990 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
991 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
992 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
993 } else {
994 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
995 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
996 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
997 !is_power_of_2(sbi->s_inode_size) ||
998 (sbi->s_inode_size > blocksize)) {
999 ext2_msg(sb, KERN_ERR,
1000 "error: unsupported inode size: %d",
1001 sbi->s_inode_size);
1002 goto failed_mount;
1003 }
1004 }
1005
1006 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1007 le32_to_cpu(es->s_log_frag_size);
1008 if (sbi->s_frag_size == 0)
1009 goto cantfind_ext2;
1010 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1011
1012 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1013 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1014 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1015
1016 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1017 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1018 goto cantfind_ext2;
1019 sbi->s_itb_per_group = sbi->s_inodes_per_group /
1020 sbi->s_inodes_per_block;
1021 sbi->s_desc_per_block = sb->s_blocksize /
1022 sizeof (struct ext2_group_desc);
1023 sbi->s_sbh = bh;
1024 sbi->s_mount_state = le16_to_cpu(es->s_state);
1025 sbi->s_addr_per_block_bits =
1026 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1027 sbi->s_desc_per_block_bits =
1028 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1029
1030 if (sb->s_magic != EXT2_SUPER_MAGIC)
1031 goto cantfind_ext2;
1032
1033 if (sb->s_blocksize != bh->b_size) {
1034 if (!silent)
1035 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1036 goto failed_mount;
1037 }
1038
1039 if (sb->s_blocksize != sbi->s_frag_size) {
1040 ext2_msg(sb, KERN_ERR,
1041 "error: fragsize %lu != blocksize %lu"
1042 "(not supported yet)",
1043 sbi->s_frag_size, sb->s_blocksize);
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_frags_per_group > sb->s_blocksize * 8) {
1054 ext2_msg(sb, KERN_ERR,
1055 "error: #fragments per group too big: %lu",
1056 sbi->s_frags_per_group);
1057 goto failed_mount;
1058 }
1059 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1060 ext2_msg(sb, KERN_ERR,
1061 "error: #inodes per group too big: %lu",
1062 sbi->s_inodes_per_group);
1063 goto failed_mount;
1064 }
1065
1066 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1067 goto cantfind_ext2;
1068 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1069 le32_to_cpu(es->s_first_data_block) - 1)
1070 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1071 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1072 EXT2_DESC_PER_BLOCK(sb);
1073 sbi->s_group_desc = kmalloc_array(db_count,
1074 sizeof(struct buffer_head *),
1075 GFP_KERNEL);
1076 if (sbi->s_group_desc == NULL) {
1077 ret = -ENOMEM;
1078 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1079 goto failed_mount;
1080 }
1081 bgl_lock_init(sbi->s_blockgroup_lock);
1082 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1083 if (!sbi->s_debts) {
1084 ret = -ENOMEM;
1085 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1086 goto failed_mount_group_desc;
1087 }
1088 for (i = 0; i < db_count; i++) {
1089 block = descriptor_loc(sb, logic_sb_block, i);
1090 sbi->s_group_desc[i] = sb_bread(sb, block);
1091 if (!sbi->s_group_desc[i]) {
1092 for (j = 0; j < i; j++)
1093 brelse (sbi->s_group_desc[j]);
1094 ext2_msg(sb, KERN_ERR,
1095 "error: unable to read group descriptors");
1096 goto failed_mount_group_desc;
1097 }
1098 }
1099 if (!ext2_check_descriptors (sb)) {
1100 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1101 goto failed_mount2;
1102 }
1103 sbi->s_gdb_count = db_count;
1104 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1105 spin_lock_init(&sbi->s_next_gen_lock);
1106
1107 /* per filesystem reservation list head & lock */
1108 spin_lock_init(&sbi->s_rsv_window_lock);
1109 sbi->s_rsv_window_root = RB_ROOT;
1110 /*
1111 * Add a single, static dummy reservation to the start of the
1112 * reservation window list --- it gives us a placeholder for
1113 * append-at-start-of-list which makes the allocation logic
1114 * _much_ simpler.
1115 */
1116 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1117 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1118 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1119 sbi->s_rsv_window_head.rsv_goal_size = 0;
1120 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1121
1122 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1123 ext2_count_free_blocks(sb), GFP_KERNEL);
1124 if (!err) {
1125 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1126 ext2_count_free_inodes(sb), GFP_KERNEL);
1127 }
1128 if (!err) {
1129 err = percpu_counter_init(&sbi->s_dirs_counter,
1130 ext2_count_dirs(sb), GFP_KERNEL);
1131 }
1132 if (err) {
1133 ret = err;
1134 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1135 goto failed_mount3;
1136 }
1137
1138 #ifdef CONFIG_EXT2_FS_XATTR
1139 sbi->s_ea_block_cache = ext2_xattr_create_cache();
1140 if (!sbi->s_ea_block_cache) {
1141 ret = -ENOMEM;
1142 ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1143 goto failed_mount3;
1144 }
1145 #endif
1146 /*
1147 * set up enough so that it can read an inode
1148 */
1149 sb->s_op = &ext2_sops;
1150 sb->s_export_op = &ext2_export_ops;
1151 sb->s_xattr = ext2_xattr_handlers;
1152
1153 #ifdef CONFIG_QUOTA
1154 sb->dq_op = &dquot_operations;
1155 sb->s_qcop = &ext2_quotactl_ops;
1156 sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1157 #endif
1158
1159 root = ext2_iget(sb, EXT2_ROOT_INO);
1160 if (IS_ERR(root)) {
1161 ret = PTR_ERR(root);
1162 goto failed_mount3;
1163 }
1164 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1165 iput(root);
1166 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1167 goto failed_mount3;
1168 }
1169
1170 sb->s_root = d_make_root(root);
1171 if (!sb->s_root) {
1172 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1173 ret = -ENOMEM;
1174 goto failed_mount3;
1175 }
1176 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1177 ext2_msg(sb, KERN_WARNING,
1178 "warning: mounting ext3 filesystem as ext2");
1179 if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1180 sb->s_flags |= SB_RDONLY;
1181 ext2_write_super(sb);
1182 return 0;
1183
1184 cantfind_ext2:
1185 if (!silent)
1186 ext2_msg(sb, KERN_ERR,
1187 "error: can't find an ext2 filesystem on dev %s.",
1188 sb->s_id);
1189 goto failed_mount;
1190 failed_mount3:
1191 ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1192 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1193 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1194 percpu_counter_destroy(&sbi->s_dirs_counter);
1195 failed_mount2:
1196 for (i = 0; i < db_count; i++)
1197 brelse(sbi->s_group_desc[i]);
1198 failed_mount_group_desc:
1199 kfree(sbi->s_group_desc);
1200 kfree(sbi->s_debts);
1201 failed_mount:
1202 brelse(bh);
1203 failed_sbi:
1204 sb->s_fs_info = NULL;
1205 kfree(sbi->s_blockgroup_lock);
1206 kfree(sbi);
1207 failed:
1208 fs_put_dax(dax_dev);
1209 return ret;
1210 }
1211
ext2_clear_super_error(struct super_block * sb)1212 static void ext2_clear_super_error(struct super_block *sb)
1213 {
1214 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1215
1216 if (buffer_write_io_error(sbh)) {
1217 /*
1218 * Oh, dear. A previous attempt to write the
1219 * superblock failed. This could happen because the
1220 * USB device was yanked out. Or it could happen to
1221 * be a transient write error and maybe the block will
1222 * be remapped. Nothing we can do but to retry the
1223 * write and hope for the best.
1224 */
1225 ext2_msg(sb, KERN_ERR,
1226 "previous I/O error to superblock detected");
1227 clear_buffer_write_io_error(sbh);
1228 set_buffer_uptodate(sbh);
1229 }
1230 }
1231
ext2_sync_super(struct super_block * sb,struct ext2_super_block * es,int wait)1232 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1233 int wait)
1234 {
1235 ext2_clear_super_error(sb);
1236 spin_lock(&EXT2_SB(sb)->s_lock);
1237 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1238 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1239 es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1240 /* unlock before we do IO */
1241 spin_unlock(&EXT2_SB(sb)->s_lock);
1242 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1243 if (wait)
1244 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1245 }
1246
1247 /*
1248 * In the second extended file system, it is not necessary to
1249 * write the super block since we use a mapping of the
1250 * disk super block in a buffer.
1251 *
1252 * However, this function is still used to set the fs valid
1253 * flags to 0. We need to set this flag to 0 since the fs
1254 * may have been checked while mounted and e2fsck may have
1255 * set s_state to EXT2_VALID_FS after some corrections.
1256 */
ext2_sync_fs(struct super_block * sb,int wait)1257 static int ext2_sync_fs(struct super_block *sb, int wait)
1258 {
1259 struct ext2_sb_info *sbi = EXT2_SB(sb);
1260 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1261
1262 /*
1263 * Write quota structures to quota file, sync_blockdev() will write
1264 * them to disk later
1265 */
1266 dquot_writeback_dquots(sb, -1);
1267
1268 spin_lock(&sbi->s_lock);
1269 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1270 ext2_debug("setting valid to 0\n");
1271 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1272 }
1273 spin_unlock(&sbi->s_lock);
1274 ext2_sync_super(sb, es, wait);
1275 return 0;
1276 }
1277
ext2_freeze(struct super_block * sb)1278 static int ext2_freeze(struct super_block *sb)
1279 {
1280 struct ext2_sb_info *sbi = EXT2_SB(sb);
1281
1282 /*
1283 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1284 * because we have unattached inodes and thus filesystem is not fully
1285 * consistent.
1286 */
1287 if (atomic_long_read(&sb->s_remove_count)) {
1288 ext2_sync_fs(sb, 1);
1289 return 0;
1290 }
1291 /* Set EXT2_FS_VALID flag */
1292 spin_lock(&sbi->s_lock);
1293 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1294 spin_unlock(&sbi->s_lock);
1295 ext2_sync_super(sb, sbi->s_es, 1);
1296
1297 return 0;
1298 }
1299
ext2_unfreeze(struct super_block * sb)1300 static int ext2_unfreeze(struct super_block *sb)
1301 {
1302 /* Just write sb to clear EXT2_VALID_FS flag */
1303 ext2_write_super(sb);
1304
1305 return 0;
1306 }
1307
ext2_write_super(struct super_block * sb)1308 static void ext2_write_super(struct super_block *sb)
1309 {
1310 if (!sb_rdonly(sb))
1311 ext2_sync_fs(sb, 1);
1312 }
1313
ext2_remount(struct super_block * sb,int * flags,char * data)1314 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1315 {
1316 struct ext2_sb_info * sbi = EXT2_SB(sb);
1317 struct ext2_super_block * es;
1318 struct ext2_mount_options new_opts;
1319 int err;
1320
1321 sync_filesystem(sb);
1322
1323 spin_lock(&sbi->s_lock);
1324 new_opts.s_mount_opt = sbi->s_mount_opt;
1325 new_opts.s_resuid = sbi->s_resuid;
1326 new_opts.s_resgid = sbi->s_resgid;
1327 spin_unlock(&sbi->s_lock);
1328
1329 if (!parse_options(data, sb, &new_opts))
1330 return -EINVAL;
1331
1332 spin_lock(&sbi->s_lock);
1333 es = sbi->s_es;
1334 if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1335 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1336 "dax flag with busy inodes while remounting");
1337 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1338 }
1339 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1340 goto out_set;
1341 if (*flags & SB_RDONLY) {
1342 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1343 !(sbi->s_mount_state & EXT2_VALID_FS))
1344 goto out_set;
1345
1346 /*
1347 * OK, we are remounting a valid rw partition rdonly, so set
1348 * the rdonly flag and then mark the partition as valid again.
1349 */
1350 es->s_state = cpu_to_le16(sbi->s_mount_state);
1351 es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1352 spin_unlock(&sbi->s_lock);
1353
1354 err = dquot_suspend(sb, -1);
1355 if (err < 0)
1356 return err;
1357
1358 ext2_sync_super(sb, es, 1);
1359 } else {
1360 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1361 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1362 if (ret) {
1363 spin_unlock(&sbi->s_lock);
1364 ext2_msg(sb, KERN_WARNING,
1365 "warning: couldn't remount RDWR because of "
1366 "unsupported optional features (%x).",
1367 le32_to_cpu(ret));
1368 return -EROFS;
1369 }
1370 /*
1371 * Mounting a RDONLY partition read-write, so reread and
1372 * store the current valid flag. (It may have been changed
1373 * by e2fsck since we originally mounted the partition.)
1374 */
1375 sbi->s_mount_state = le16_to_cpu(es->s_state);
1376 if (!ext2_setup_super (sb, es, 0))
1377 sb->s_flags &= ~SB_RDONLY;
1378 spin_unlock(&sbi->s_lock);
1379
1380 ext2_write_super(sb);
1381
1382 dquot_resume(sb, -1);
1383 }
1384
1385 spin_lock(&sbi->s_lock);
1386 out_set:
1387 sbi->s_mount_opt = new_opts.s_mount_opt;
1388 sbi->s_resuid = new_opts.s_resuid;
1389 sbi->s_resgid = new_opts.s_resgid;
1390 sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1391 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
1392 spin_unlock(&sbi->s_lock);
1393
1394 return 0;
1395 }
1396
ext2_statfs(struct dentry * dentry,struct kstatfs * buf)1397 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1398 {
1399 struct super_block *sb = dentry->d_sb;
1400 struct ext2_sb_info *sbi = EXT2_SB(sb);
1401 struct ext2_super_block *es = sbi->s_es;
1402
1403 spin_lock(&sbi->s_lock);
1404
1405 if (test_opt (sb, MINIX_DF))
1406 sbi->s_overhead_last = 0;
1407 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1408 unsigned long i, overhead = 0;
1409 smp_rmb();
1410
1411 /*
1412 * Compute the overhead (FS structures). This is constant
1413 * for a given filesystem unless the number of block groups
1414 * changes so we cache the previous value until it does.
1415 */
1416
1417 /*
1418 * All of the blocks before first_data_block are
1419 * overhead
1420 */
1421 overhead = le32_to_cpu(es->s_first_data_block);
1422
1423 /*
1424 * Add the overhead attributed to the superblock and
1425 * block group descriptors. If the sparse superblocks
1426 * feature is turned on, then not all groups have this.
1427 */
1428 for (i = 0; i < sbi->s_groups_count; i++)
1429 overhead += ext2_bg_has_super(sb, i) +
1430 ext2_bg_num_gdb(sb, i);
1431
1432 /*
1433 * Every block group has an inode bitmap, a block
1434 * bitmap, and an inode table.
1435 */
1436 overhead += (sbi->s_groups_count *
1437 (2 + sbi->s_itb_per_group));
1438 sbi->s_overhead_last = overhead;
1439 smp_wmb();
1440 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1441 }
1442
1443 buf->f_type = EXT2_SUPER_MAGIC;
1444 buf->f_bsize = sb->s_blocksize;
1445 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1446 buf->f_bfree = ext2_count_free_blocks(sb);
1447 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1448 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1449 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1450 buf->f_bavail = 0;
1451 buf->f_files = le32_to_cpu(es->s_inodes_count);
1452 buf->f_ffree = ext2_count_free_inodes(sb);
1453 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1454 buf->f_namelen = EXT2_NAME_LEN;
1455 buf->f_fsid = uuid_to_fsid(es->s_uuid);
1456 spin_unlock(&sbi->s_lock);
1457 return 0;
1458 }
1459
ext2_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)1460 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1461 int flags, const char *dev_name, void *data)
1462 {
1463 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1464 }
1465
1466 #ifdef CONFIG_QUOTA
1467
1468 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1469 * acquiring the locks... As quota files are never truncated and quota code
1470 * itself serializes the operations (and no one else should touch the files)
1471 * 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)1472 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1473 size_t len, loff_t off)
1474 {
1475 struct inode *inode = sb_dqopt(sb)->files[type];
1476 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1477 int err = 0;
1478 int offset = off & (sb->s_blocksize - 1);
1479 int tocopy;
1480 size_t toread;
1481 struct buffer_head tmp_bh;
1482 struct buffer_head *bh;
1483 loff_t i_size = i_size_read(inode);
1484
1485 if (off > i_size)
1486 return 0;
1487 if (off+len > i_size)
1488 len = i_size-off;
1489 toread = len;
1490 while (toread > 0) {
1491 tocopy = sb->s_blocksize - offset < toread ?
1492 sb->s_blocksize - offset : toread;
1493
1494 tmp_bh.b_state = 0;
1495 tmp_bh.b_size = sb->s_blocksize;
1496 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1497 if (err < 0)
1498 return err;
1499 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1500 memset(data, 0, tocopy);
1501 else {
1502 bh = sb_bread(sb, tmp_bh.b_blocknr);
1503 if (!bh)
1504 return -EIO;
1505 memcpy(data, bh->b_data+offset, tocopy);
1506 brelse(bh);
1507 }
1508 offset = 0;
1509 toread -= tocopy;
1510 data += tocopy;
1511 blk++;
1512 }
1513 return len;
1514 }
1515
1516 /* Write to quotafile */
ext2_quota_write(struct super_block * sb,int type,const char * data,size_t len,loff_t off)1517 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1518 const char *data, size_t len, loff_t off)
1519 {
1520 struct inode *inode = sb_dqopt(sb)->files[type];
1521 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1522 int err = 0;
1523 int offset = off & (sb->s_blocksize - 1);
1524 int tocopy;
1525 size_t towrite = len;
1526 struct buffer_head tmp_bh;
1527 struct buffer_head *bh;
1528
1529 while (towrite > 0) {
1530 tocopy = sb->s_blocksize - offset < towrite ?
1531 sb->s_blocksize - offset : towrite;
1532
1533 tmp_bh.b_state = 0;
1534 tmp_bh.b_size = sb->s_blocksize;
1535 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1536 if (err < 0)
1537 goto out;
1538 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1539 bh = sb_bread(sb, tmp_bh.b_blocknr);
1540 else
1541 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1542 if (unlikely(!bh)) {
1543 err = -EIO;
1544 goto out;
1545 }
1546 lock_buffer(bh);
1547 memcpy(bh->b_data+offset, data, tocopy);
1548 flush_dcache_page(bh->b_page);
1549 set_buffer_uptodate(bh);
1550 mark_buffer_dirty(bh);
1551 unlock_buffer(bh);
1552 brelse(bh);
1553 offset = 0;
1554 towrite -= tocopy;
1555 data += tocopy;
1556 blk++;
1557 }
1558 out:
1559 if (len == towrite)
1560 return err;
1561 if (inode->i_size < off+len-towrite)
1562 i_size_write(inode, off+len-towrite);
1563 inode_inc_iversion(inode);
1564 inode->i_mtime = inode->i_ctime = current_time(inode);
1565 mark_inode_dirty(inode);
1566 return len - towrite;
1567 }
1568
ext2_quota_on(struct super_block * sb,int type,int format_id,const struct path * path)1569 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1570 const struct path *path)
1571 {
1572 int err;
1573 struct inode *inode;
1574
1575 err = dquot_quota_on(sb, type, format_id, path);
1576 if (err)
1577 return err;
1578
1579 inode = d_inode(path->dentry);
1580 inode_lock(inode);
1581 EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1582 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1583 S_NOATIME | S_IMMUTABLE);
1584 inode_unlock(inode);
1585 mark_inode_dirty(inode);
1586
1587 return 0;
1588 }
1589
ext2_quota_off(struct super_block * sb,int type)1590 static int ext2_quota_off(struct super_block *sb, int type)
1591 {
1592 struct inode *inode = sb_dqopt(sb)->files[type];
1593 int err;
1594
1595 if (!inode || !igrab(inode))
1596 goto out;
1597
1598 err = dquot_quota_off(sb, type);
1599 if (err)
1600 goto out_put;
1601
1602 inode_lock(inode);
1603 EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1604 inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1605 inode_unlock(inode);
1606 mark_inode_dirty(inode);
1607 out_put:
1608 iput(inode);
1609 return err;
1610 out:
1611 return dquot_quota_off(sb, type);
1612 }
1613
1614 #endif
1615
1616 static struct file_system_type ext2_fs_type = {
1617 .owner = THIS_MODULE,
1618 .name = "ext2",
1619 .mount = ext2_mount,
1620 .kill_sb = kill_block_super,
1621 .fs_flags = FS_REQUIRES_DEV,
1622 };
1623 MODULE_ALIAS_FS("ext2");
1624
init_ext2_fs(void)1625 static int __init init_ext2_fs(void)
1626 {
1627 int err;
1628
1629 err = init_inodecache();
1630 if (err)
1631 return err;
1632 err = register_filesystem(&ext2_fs_type);
1633 if (err)
1634 goto out;
1635 return 0;
1636 out:
1637 destroy_inodecache();
1638 return err;
1639 }
1640
exit_ext2_fs(void)1641 static void __exit exit_ext2_fs(void)
1642 {
1643 unregister_filesystem(&ext2_fs_type);
1644 destroy_inodecache();
1645 }
1646
1647 MODULE_AUTHOR("Remy Card and others");
1648 MODULE_DESCRIPTION("Second Extended Filesystem");
1649 MODULE_LICENSE("GPL");
1650 module_init(init_ext2_fs)
1651 module_exit(exit_ext2_fs)
1652