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/fs_context.h>
27 #include <linux/fs_parser.h>
28 #include <linux/random.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/seq_file.h>
33 #include <linux/mount.h>
34 #include <linux/log2.h>
35 #include <linux/quotaops.h>
36 #include <linux/uaccess.h>
37 #include <linux/dax.h>
38 #include <linux/iversion.h>
39 #include "ext2.h"
40 #include "xattr.h"
41 #include "acl.h"
42
43 static void ext2_write_super(struct super_block *sb);
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_fc(struct fs_context * fc,const char * prefix,const char * fmt,...)84 static void ext2_msg_fc(struct fs_context *fc, const char *prefix,
85 const char *fmt, ...)
86 {
87 struct va_format vaf;
88 va_list args;
89 const char *s_id;
90
91 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
92 s_id = fc->root->d_sb->s_id;
93 } else {
94 /* get last path component of source */
95 s_id = strrchr(fc->source, '/');
96 if (s_id)
97 s_id++;
98 else
99 s_id = fc->source;
100 }
101 va_start(args, fmt);
102
103 vaf.fmt = fmt;
104 vaf.va = &args;
105
106 printk("%sEXT2-fs (%s): %pV\n", prefix, s_id, &vaf);
107
108 va_end(args);
109 }
110
ext2_msg(struct super_block * sb,const char * prefix,const char * fmt,...)111 void ext2_msg(struct super_block *sb, const char *prefix,
112 const char *fmt, ...)
113 {
114 struct va_format vaf;
115 va_list args;
116
117 va_start(args, fmt);
118
119 vaf.fmt = fmt;
120 vaf.va = &args;
121
122 printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
123
124 va_end(args);
125 }
126
127 /*
128 * This must be called with sbi->s_lock held.
129 */
ext2_update_dynamic_rev(struct super_block * sb)130 void ext2_update_dynamic_rev(struct super_block *sb)
131 {
132 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
133
134 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
135 return;
136
137 ext2_msg(sb, KERN_WARNING,
138 "warning: updating to rev %d because of "
139 "new feature flag, running e2fsck is recommended",
140 EXT2_DYNAMIC_REV);
141
142 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
143 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
144 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
145 /* leave es->s_feature_*compat flags alone */
146 /* es->s_uuid will be set by e2fsck if empty */
147
148 /*
149 * The rest of the superblock fields should be zero, and if not it
150 * means they are likely already in use, so leave them alone. We
151 * can leave it up to e2fsck to clean up any inconsistencies there.
152 */
153 }
154
155 #ifdef CONFIG_QUOTA
156 static int ext2_quota_off(struct super_block *sb, int type);
157
ext2_quota_off_umount(struct super_block * sb)158 static void ext2_quota_off_umount(struct super_block *sb)
159 {
160 int type;
161
162 for (type = 0; type < MAXQUOTAS; type++)
163 ext2_quota_off(sb, type);
164 }
165 #else
ext2_quota_off_umount(struct super_block * sb)166 static inline void ext2_quota_off_umount(struct super_block *sb)
167 {
168 }
169 #endif
170
ext2_put_super(struct super_block * sb)171 static void ext2_put_super (struct super_block * sb)
172 {
173 int db_count;
174 int i;
175 struct ext2_sb_info *sbi = EXT2_SB(sb);
176
177 ext2_quota_off_umount(sb);
178
179 ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
180 sbi->s_ea_block_cache = NULL;
181
182 if (!sb_rdonly(sb)) {
183 struct ext2_super_block *es = sbi->s_es;
184
185 spin_lock(&sbi->s_lock);
186 es->s_state = cpu_to_le16(sbi->s_mount_state);
187 spin_unlock(&sbi->s_lock);
188 ext2_sync_super(sb, es, 1);
189 }
190 db_count = sbi->s_gdb_count;
191 for (i = 0; i < db_count; i++)
192 brelse(sbi->s_group_desc[i]);
193 kvfree(sbi->s_group_desc);
194 kfree(sbi->s_debts);
195 percpu_counter_destroy(&sbi->s_freeblocks_counter);
196 percpu_counter_destroy(&sbi->s_freeinodes_counter);
197 percpu_counter_destroy(&sbi->s_dirs_counter);
198 brelse (sbi->s_sbh);
199 sb->s_fs_info = NULL;
200 kfree(sbi->s_blockgroup_lock);
201 fs_put_dax(sbi->s_daxdev, NULL);
202 kfree(sbi);
203 }
204
205 static struct kmem_cache * ext2_inode_cachep;
206
ext2_alloc_inode(struct super_block * sb)207 static struct inode *ext2_alloc_inode(struct super_block *sb)
208 {
209 struct ext2_inode_info *ei;
210 ei = alloc_inode_sb(sb, ext2_inode_cachep, GFP_KERNEL);
211 if (!ei)
212 return NULL;
213 ei->i_block_alloc_info = NULL;
214 inode_set_iversion(&ei->vfs_inode, 1);
215 #ifdef CONFIG_QUOTA
216 memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
217 #endif
218 mmb_init(&ei->i_metadata_bhs, &ei->vfs_inode.i_data);
219
220 return &ei->vfs_inode;
221 }
222
ext2_free_in_core_inode(struct inode * inode)223 static void ext2_free_in_core_inode(struct inode *inode)
224 {
225 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
226 }
227
init_once(void * foo)228 static void init_once(void *foo)
229 {
230 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
231
232 rwlock_init(&ei->i_meta_lock);
233 #ifdef CONFIG_EXT2_FS_XATTR
234 init_rwsem(&ei->xattr_sem);
235 #endif
236 mutex_init(&ei->truncate_mutex);
237 inode_init_once(&ei->vfs_inode);
238 }
239
init_inodecache(void)240 static int __init init_inodecache(void)
241 {
242 ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
243 sizeof(struct ext2_inode_info), 0,
244 SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
245 offsetof(struct ext2_inode_info, i_data),
246 sizeof_field(struct ext2_inode_info, i_data),
247 init_once);
248 if (ext2_inode_cachep == NULL)
249 return -ENOMEM;
250 return 0;
251 }
252
destroy_inodecache(void)253 static void destroy_inodecache(void)
254 {
255 /*
256 * Make sure all delayed rcu free inodes are flushed before we
257 * destroy cache.
258 */
259 rcu_barrier();
260 kmem_cache_destroy(ext2_inode_cachep);
261 }
262
ext2_show_options(struct seq_file * seq,struct dentry * root)263 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
264 {
265 struct super_block *sb = root->d_sb;
266 struct ext2_sb_info *sbi = EXT2_SB(sb);
267 struct ext2_super_block *es = sbi->s_es;
268 unsigned long def_mount_opts;
269
270 spin_lock(&sbi->s_lock);
271 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
272
273 if (sbi->s_sb_block != 1)
274 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
275 if (test_opt(sb, MINIX_DF))
276 seq_puts(seq, ",minixdf");
277 if (test_opt(sb, GRPID))
278 seq_puts(seq, ",grpid");
279 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
280 seq_puts(seq, ",nogrpid");
281 if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
282 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
283 seq_printf(seq, ",resuid=%u",
284 from_kuid_munged(&init_user_ns, sbi->s_resuid));
285 }
286 if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
287 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
288 seq_printf(seq, ",resgid=%u",
289 from_kgid_munged(&init_user_ns, sbi->s_resgid));
290 }
291 if (test_opt(sb, ERRORS_RO)) {
292 int def_errors = le16_to_cpu(es->s_errors);
293
294 if (def_errors == EXT2_ERRORS_PANIC ||
295 def_errors == EXT2_ERRORS_CONTINUE) {
296 seq_puts(seq, ",errors=remount-ro");
297 }
298 }
299 if (test_opt(sb, ERRORS_CONT))
300 seq_puts(seq, ",errors=continue");
301 if (test_opt(sb, ERRORS_PANIC))
302 seq_puts(seq, ",errors=panic");
303 if (test_opt(sb, NO_UID32))
304 seq_puts(seq, ",nouid32");
305 if (test_opt(sb, DEBUG))
306 seq_puts(seq, ",debug");
307 if (test_opt(sb, OLDALLOC))
308 seq_puts(seq, ",oldalloc");
309
310 #ifdef CONFIG_EXT2_FS_XATTR
311 if (test_opt(sb, XATTR_USER))
312 seq_puts(seq, ",user_xattr");
313 if (!test_opt(sb, XATTR_USER) &&
314 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
315 seq_puts(seq, ",nouser_xattr");
316 }
317 #endif
318
319 #ifdef CONFIG_EXT2_FS_POSIX_ACL
320 if (test_opt(sb, POSIX_ACL))
321 seq_puts(seq, ",acl");
322 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
323 seq_puts(seq, ",noacl");
324 #endif
325
326 if (test_opt(sb, USRQUOTA))
327 seq_puts(seq, ",usrquota");
328
329 if (test_opt(sb, GRPQUOTA))
330 seq_puts(seq, ",grpquota");
331
332 if (test_opt(sb, XIP))
333 seq_puts(seq, ",xip");
334
335 if (test_opt(sb, DAX))
336 seq_puts(seq, ",dax");
337
338 if (!test_opt(sb, RESERVATION))
339 seq_puts(seq, ",noreservation");
340
341 spin_unlock(&sbi->s_lock);
342 return 0;
343 }
344
345 #ifdef CONFIG_QUOTA
346 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
347 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
348 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
349 const struct path *path);
ext2_get_dquots(struct inode * inode)350 static struct dquot __rcu **ext2_get_dquots(struct inode *inode)
351 {
352 return EXT2_I(inode)->i_dquot;
353 }
354
355 static const struct quotactl_ops ext2_quotactl_ops = {
356 .quota_on = ext2_quota_on,
357 .quota_off = ext2_quota_off,
358 .quota_sync = dquot_quota_sync,
359 .get_state = dquot_get_state,
360 .set_info = dquot_set_dqinfo,
361 .get_dqblk = dquot_get_dqblk,
362 .set_dqblk = dquot_set_dqblk,
363 .get_nextdqblk = dquot_get_next_dqblk,
364 };
365 #endif
366
367 static const struct super_operations ext2_sops = {
368 .alloc_inode = ext2_alloc_inode,
369 .free_inode = ext2_free_in_core_inode,
370 .write_inode = ext2_write_inode,
371 .evict_inode = ext2_evict_inode,
372 .put_super = ext2_put_super,
373 .sync_fs = ext2_sync_fs,
374 .freeze_fs = ext2_freeze,
375 .unfreeze_fs = ext2_unfreeze,
376 .statfs = ext2_statfs,
377 .show_options = ext2_show_options,
378 #ifdef CONFIG_QUOTA
379 .quota_read = ext2_quota_read,
380 .quota_write = ext2_quota_write,
381 .get_dquots = ext2_get_dquots,
382 #endif
383 };
384
ext2_nfs_get_inode(struct super_block * sb,u64 ino,u32 generation)385 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
386 u64 ino, u32 generation)
387 {
388 struct inode *inode;
389
390 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
391 return ERR_PTR(-ESTALE);
392 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
393 return ERR_PTR(-ESTALE);
394
395 /*
396 * ext2_iget isn't quite right if the inode is currently unallocated!
397 * However ext2_iget currently does appropriate checks to handle stale
398 * inodes so everything is OK.
399 */
400 inode = ext2_iget(sb, ino);
401 if (IS_ERR(inode))
402 return ERR_CAST(inode);
403 if (generation && inode->i_generation != generation) {
404 /* we didn't find the right inode.. */
405 iput(inode);
406 return ERR_PTR(-ESTALE);
407 }
408 return inode;
409 }
410
ext2_fh_to_dentry(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)411 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
412 int fh_len, int fh_type)
413 {
414 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
415 ext2_nfs_get_inode);
416 }
417
ext2_fh_to_parent(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)418 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
419 int fh_len, int fh_type)
420 {
421 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
422 ext2_nfs_get_inode);
423 }
424
425 static const struct export_operations ext2_export_ops = {
426 .encode_fh = generic_encode_ino32_fh,
427 .fh_to_dentry = ext2_fh_to_dentry,
428 .fh_to_parent = ext2_fh_to_parent,
429 .get_parent = ext2_get_parent,
430 };
431
432 enum {
433 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, Opt_resgid, Opt_resuid,
434 Opt_sb, Opt_errors, Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
435 Opt_nobh, Opt_user_xattr, Opt_acl, Opt_xip, Opt_dax, Opt_ignore,
436 Opt_quota, Opt_usrquota, Opt_grpquota, Opt_reservation,
437 };
438
439 static const struct constant_table ext2_param_errors[] = {
440 {"continue", EXT2_MOUNT_ERRORS_CONT},
441 {"panic", EXT2_MOUNT_ERRORS_PANIC},
442 {"remount-ro", EXT2_MOUNT_ERRORS_RO},
443 {}
444 };
445
446 static const struct fs_parameter_spec ext2_param_spec[] = {
447 fsparam_flag ("bsddf", Opt_bsd_df),
448 fsparam_flag ("minixdf", Opt_minix_df),
449 fsparam_flag ("grpid", Opt_grpid),
450 fsparam_flag ("bsdgroups", Opt_grpid),
451 fsparam_flag ("nogrpid", Opt_nogrpid),
452 fsparam_flag ("sysvgroups", Opt_nogrpid),
453 fsparam_gid ("resgid", Opt_resgid),
454 fsparam_uid ("resuid", Opt_resuid),
455 fsparam_u32 ("sb", Opt_sb),
456 fsparam_enum ("errors", Opt_errors, ext2_param_errors),
457 fsparam_flag ("nouid32", Opt_nouid32),
458 fsparam_flag ("debug", Opt_debug),
459 fsparam_flag ("oldalloc", Opt_oldalloc),
460 fsparam_flag ("orlov", Opt_orlov),
461 fsparam_flag ("nobh", Opt_nobh),
462 fsparam_flag_no ("user_xattr", Opt_user_xattr),
463 fsparam_flag_no ("acl", Opt_acl),
464 fsparam_flag ("xip", Opt_xip),
465 fsparam_flag ("dax", Opt_dax),
466 fsparam_flag ("grpquota", Opt_grpquota),
467 fsparam_flag ("noquota", Opt_ignore),
468 fsparam_flag ("quota", Opt_quota),
469 fsparam_flag ("usrquota", Opt_usrquota),
470 fsparam_flag_no ("reservation", Opt_reservation),
471 {}
472 };
473
474 #define EXT2_SPEC_s_resuid (1 << 0)
475 #define EXT2_SPEC_s_resgid (1 << 1)
476
477 struct ext2_fs_context {
478 unsigned long vals_s_flags; /* Bits to set in s_flags */
479 unsigned long mask_s_flags; /* Bits changed in s_flags */
480 unsigned int vals_s_mount_opt;
481 unsigned int mask_s_mount_opt;
482 kuid_t s_resuid;
483 kgid_t s_resgid;
484 unsigned long s_sb_block;
485 unsigned int spec;
486
487 };
488
ctx_set_mount_opt(struct ext2_fs_context * ctx,unsigned long flag)489 static inline void ctx_set_mount_opt(struct ext2_fs_context *ctx,
490 unsigned long flag)
491 {
492 ctx->mask_s_mount_opt |= flag;
493 ctx->vals_s_mount_opt |= flag;
494 }
495
ctx_clear_mount_opt(struct ext2_fs_context * ctx,unsigned long flag)496 static inline void ctx_clear_mount_opt(struct ext2_fs_context *ctx,
497 unsigned long flag)
498 {
499 ctx->mask_s_mount_opt |= flag;
500 ctx->vals_s_mount_opt &= ~flag;
501 }
502
503 static inline unsigned long
ctx_test_mount_opt(struct ext2_fs_context * ctx,unsigned long flag)504 ctx_test_mount_opt(struct ext2_fs_context *ctx, unsigned long flag)
505 {
506 return (ctx->vals_s_mount_opt & flag);
507 }
508
509 static inline bool
ctx_parsed_mount_opt(struct ext2_fs_context * ctx,unsigned long flag)510 ctx_parsed_mount_opt(struct ext2_fs_context *ctx, unsigned long flag)
511 {
512 return (ctx->mask_s_mount_opt & flag);
513 }
514
ext2_free_fc(struct fs_context * fc)515 static void ext2_free_fc(struct fs_context *fc)
516 {
517 kfree(fc->fs_private);
518 }
519
ext2_parse_param(struct fs_context * fc,struct fs_parameter * param)520 static int ext2_parse_param(struct fs_context *fc, struct fs_parameter *param)
521 {
522 struct ext2_fs_context *ctx = fc->fs_private;
523 int opt;
524 struct fs_parse_result result;
525
526 opt = fs_parse(fc, ext2_param_spec, param, &result);
527 if (opt < 0)
528 return opt;
529
530 switch (opt) {
531 case Opt_bsd_df:
532 ctx_clear_mount_opt(ctx, EXT2_MOUNT_MINIX_DF);
533 break;
534 case Opt_minix_df:
535 ctx_set_mount_opt(ctx, EXT2_MOUNT_MINIX_DF);
536 break;
537 case Opt_grpid:
538 ctx_set_mount_opt(ctx, EXT2_MOUNT_GRPID);
539 break;
540 case Opt_nogrpid:
541 ctx_clear_mount_opt(ctx, EXT2_MOUNT_GRPID);
542 break;
543 case Opt_resuid:
544 ctx->s_resuid = result.uid;
545 ctx->spec |= EXT2_SPEC_s_resuid;
546 break;
547 case Opt_resgid:
548 ctx->s_resgid = result.gid;
549 ctx->spec |= EXT2_SPEC_s_resgid;
550 break;
551 case Opt_sb:
552 /* Note that this is silently ignored on remount */
553 ctx->s_sb_block = result.uint_32;
554 break;
555 case Opt_errors:
556 ctx_clear_mount_opt(ctx, EXT2_MOUNT_ERRORS_MASK);
557 ctx_set_mount_opt(ctx, result.uint_32);
558 break;
559 case Opt_nouid32:
560 ctx_set_mount_opt(ctx, EXT2_MOUNT_NO_UID32);
561 break;
562 case Opt_debug:
563 ctx_set_mount_opt(ctx, EXT2_MOUNT_DEBUG);
564 break;
565 case Opt_oldalloc:
566 ctx_set_mount_opt(ctx, EXT2_MOUNT_OLDALLOC);
567 break;
568 case Opt_orlov:
569 ctx_clear_mount_opt(ctx, EXT2_MOUNT_OLDALLOC);
570 break;
571 case Opt_nobh:
572 ext2_msg_fc(fc, KERN_INFO, "nobh option not supported\n");
573 break;
574 #ifdef CONFIG_EXT2_FS_XATTR
575 case Opt_user_xattr:
576 if (!result.negated)
577 ctx_set_mount_opt(ctx, EXT2_MOUNT_XATTR_USER);
578 else
579 ctx_clear_mount_opt(ctx, EXT2_MOUNT_XATTR_USER);
580 break;
581 #else
582 case Opt_user_xattr:
583 ext2_msg_fc(fc, KERN_INFO, "(no)user_xattr options not supported");
584 break;
585 #endif
586 #ifdef CONFIG_EXT2_FS_POSIX_ACL
587 case Opt_acl:
588 if (!result.negated)
589 ctx_set_mount_opt(ctx, EXT2_MOUNT_POSIX_ACL);
590 else
591 ctx_clear_mount_opt(ctx, EXT2_MOUNT_POSIX_ACL);
592 break;
593 #else
594 case Opt_acl:
595 ext2_msg_fc(fc, KERN_INFO, "(no)acl options not supported");
596 break;
597 #endif
598 case Opt_xip:
599 ext2_msg_fc(fc, KERN_INFO, "use dax instead of xip");
600 ctx_set_mount_opt(ctx, EXT2_MOUNT_XIP);
601 fallthrough;
602 case Opt_dax:
603 #ifdef CONFIG_FS_DAX
604 ext2_msg_fc(fc, KERN_WARNING,
605 "DAX enabled. Warning: DAX support in ext2 driver is deprecated"
606 " and will be removed at the end of 2025. Please use ext4 driver instead.");
607 ctx_set_mount_opt(ctx, EXT2_MOUNT_DAX);
608 #else
609 ext2_msg_fc(fc, KERN_INFO, "dax option not supported");
610 #endif
611 break;
612
613 #if defined(CONFIG_QUOTA)
614 case Opt_quota:
615 case Opt_usrquota:
616 ctx_set_mount_opt(ctx, EXT2_MOUNT_USRQUOTA);
617 break;
618
619 case Opt_grpquota:
620 ctx_set_mount_opt(ctx, EXT2_MOUNT_GRPQUOTA);
621 break;
622 #else
623 case Opt_quota:
624 case Opt_usrquota:
625 case Opt_grpquota:
626 ext2_msg_fc(fc, KERN_INFO, "quota operations not supported");
627 break;
628 #endif
629 case Opt_reservation:
630 if (!result.negated) {
631 ctx_set_mount_opt(ctx, EXT2_MOUNT_RESERVATION);
632 ext2_msg_fc(fc, KERN_INFO, "reservations ON");
633 } else {
634 ctx_clear_mount_opt(ctx, EXT2_MOUNT_RESERVATION);
635 ext2_msg_fc(fc, KERN_INFO, "reservations OFF");
636 }
637 break;
638 case Opt_ignore:
639 break;
640 default:
641 return -EINVAL;
642 }
643 return 0;
644 }
645
ext2_setup_super(struct super_block * sb,struct ext2_super_block * es,int read_only)646 static int ext2_setup_super (struct super_block * sb,
647 struct ext2_super_block * es,
648 int read_only)
649 {
650 int res = 0;
651 struct ext2_sb_info *sbi = EXT2_SB(sb);
652
653 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
654 ext2_msg(sb, KERN_ERR,
655 "error: revision level too high, "
656 "forcing read-only mode");
657 res = SB_RDONLY;
658 }
659 if (read_only)
660 return res;
661 if (!(sbi->s_mount_state & EXT2_VALID_FS))
662 ext2_msg(sb, KERN_WARNING,
663 "warning: mounting unchecked fs, "
664 "running e2fsck is recommended");
665 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
666 ext2_msg(sb, KERN_WARNING,
667 "warning: mounting fs with errors, "
668 "running e2fsck is recommended");
669 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
670 le16_to_cpu(es->s_mnt_count) >=
671 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
672 ext2_msg(sb, KERN_WARNING,
673 "warning: maximal mount count reached, "
674 "running e2fsck is recommended");
675 else if (le32_to_cpu(es->s_checkinterval) &&
676 (le32_to_cpu(es->s_lastcheck) +
677 le32_to_cpu(es->s_checkinterval) <=
678 ktime_get_real_seconds()))
679 ext2_msg(sb, KERN_WARNING,
680 "warning: checktime reached, "
681 "running e2fsck is recommended");
682 if (!le16_to_cpu(es->s_max_mnt_count))
683 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
684 le16_add_cpu(&es->s_mnt_count, 1);
685 if (test_opt (sb, DEBUG))
686 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, gc=%lu, "
687 "bpg=%lu, ipg=%lu, mo=%04lx]",
688 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
689 sbi->s_groups_count,
690 EXT2_BLOCKS_PER_GROUP(sb),
691 EXT2_INODES_PER_GROUP(sb),
692 sbi->s_mount_opt);
693 return res;
694 }
695
ext2_check_descriptors(struct super_block * sb)696 static int ext2_check_descriptors(struct super_block *sb)
697 {
698 int i;
699 struct ext2_sb_info *sbi = EXT2_SB(sb);
700
701 ext2_debug ("Checking group descriptors");
702
703 for (i = 0; i < sbi->s_groups_count; i++) {
704 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
705 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
706 ext2_fsblk_t last_block = ext2_group_last_block_no(sb, i);
707
708 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
709 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
710 {
711 ext2_error (sb, "ext2_check_descriptors",
712 "Block bitmap for group %d"
713 " not in group (block %lu)!",
714 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
715 return 0;
716 }
717 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
718 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
719 {
720 ext2_error (sb, "ext2_check_descriptors",
721 "Inode bitmap for group %d"
722 " not in group (block %lu)!",
723 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
724 return 0;
725 }
726 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
727 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
728 last_block)
729 {
730 ext2_error (sb, "ext2_check_descriptors",
731 "Inode table for group %d"
732 " not in group (block %lu)!",
733 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
734 return 0;
735 }
736 }
737 return 1;
738 }
739
740 /*
741 * Maximal file size. There is a direct, and {,double-,triple-}indirect
742 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
743 * We need to be 1 filesystem block less than the 2^32 sector limit.
744 */
ext2_max_size(int bits)745 static loff_t ext2_max_size(int bits)
746 {
747 loff_t res = EXT2_NDIR_BLOCKS;
748 int meta_blocks;
749 unsigned int upper_limit;
750 unsigned int ppb = 1 << (bits-2);
751
752 /* This is calculated to be the largest file size for a
753 * dense, file such that the total number of
754 * sectors in the file, including data and all indirect blocks,
755 * does not exceed 2^32 -1
756 * __u32 i_blocks representing the total number of
757 * 512 bytes blocks of the file
758 */
759 upper_limit = (1LL << 32) - 1;
760
761 /* total blocks in file system block size */
762 upper_limit >>= (bits - 9);
763
764 /* Compute how many blocks we can address by block tree */
765 res += 1LL << (bits-2);
766 res += 1LL << (2*(bits-2));
767 res += 1LL << (3*(bits-2));
768 /* Compute how many metadata blocks are needed */
769 meta_blocks = 1;
770 meta_blocks += 1 + ppb;
771 meta_blocks += 1 + ppb + ppb * ppb;
772 /* Does block tree limit file size? */
773 if (res + meta_blocks <= upper_limit)
774 goto check_lfs;
775
776 res = upper_limit;
777 /* How many metadata blocks are needed for addressing upper_limit? */
778 upper_limit -= EXT2_NDIR_BLOCKS;
779 /* indirect blocks */
780 meta_blocks = 1;
781 upper_limit -= ppb;
782 /* double indirect blocks */
783 if (upper_limit < ppb * ppb) {
784 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
785 res -= meta_blocks;
786 goto check_lfs;
787 }
788 meta_blocks += 1 + ppb;
789 upper_limit -= ppb * ppb;
790 /* tripple indirect blocks for the rest */
791 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
792 DIV_ROUND_UP(upper_limit, ppb*ppb);
793 res -= meta_blocks;
794 check_lfs:
795 res <<= bits;
796 if (res > MAX_LFS_FILESIZE)
797 res = MAX_LFS_FILESIZE;
798
799 return res;
800 }
801
descriptor_loc(struct super_block * sb,unsigned long logic_sb_block,int nr)802 static unsigned long descriptor_loc(struct super_block *sb,
803 unsigned long logic_sb_block,
804 int nr)
805 {
806 struct ext2_sb_info *sbi = EXT2_SB(sb);
807 unsigned long bg, first_meta_bg;
808
809 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
810
811 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
812 nr < first_meta_bg)
813 return (logic_sb_block + nr + 1);
814 bg = sbi->s_desc_per_block * nr;
815
816 return ext2_group_first_block_no(sb, bg) + ext2_bg_has_super(sb, bg);
817 }
818
819 /*
820 * Set all mount options either from defaults on disk, or from parsed
821 * options. Parsed/specified options override on-disk defaults.
822 */
ext2_set_options(struct fs_context * fc,struct ext2_sb_info * sbi)823 static void ext2_set_options(struct fs_context *fc, struct ext2_sb_info *sbi)
824 {
825 struct ext2_fs_context *ctx = fc->fs_private;
826 struct ext2_super_block *es = sbi->s_es;
827 unsigned long def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
828
829 /* Copy parsed mount options to sbi */
830 sbi->s_mount_opt = ctx->vals_s_mount_opt;
831
832 /* Use in-superblock defaults only if not specified during parsing */
833 if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_DEBUG) &&
834 def_mount_opts & EXT2_DEFM_DEBUG)
835 set_opt(sbi->s_mount_opt, DEBUG);
836
837 if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_GRPID) &&
838 def_mount_opts & EXT2_DEFM_BSDGROUPS)
839 set_opt(sbi->s_mount_opt, GRPID);
840
841 if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_NO_UID32) &&
842 def_mount_opts & EXT2_DEFM_UID16)
843 set_opt(sbi->s_mount_opt, NO_UID32);
844
845 #ifdef CONFIG_EXT2_FS_XATTR
846 if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_XATTR_USER) &&
847 def_mount_opts & EXT2_DEFM_XATTR_USER)
848 set_opt(sbi->s_mount_opt, XATTR_USER);
849 #endif
850 #ifdef CONFIG_EXT2_FS_POSIX_ACL
851 if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_POSIX_ACL) &&
852 def_mount_opts & EXT2_DEFM_ACL)
853 set_opt(sbi->s_mount_opt, POSIX_ACL);
854 #endif
855
856 if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_ERRORS_MASK)) {
857 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
858 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
859 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
860 set_opt(sbi->s_mount_opt, ERRORS_CONT);
861 else
862 set_opt(sbi->s_mount_opt, ERRORS_RO);
863 }
864
865 if (ctx->spec & EXT2_SPEC_s_resuid)
866 sbi->s_resuid = ctx->s_resuid;
867 else
868 sbi->s_resuid = make_kuid(&init_user_ns,
869 le16_to_cpu(es->s_def_resuid));
870
871 if (ctx->spec & EXT2_SPEC_s_resgid)
872 sbi->s_resgid = ctx->s_resgid;
873 else
874 sbi->s_resgid = make_kgid(&init_user_ns,
875 le16_to_cpu(es->s_def_resgid));
876 }
877
ext2_fill_super(struct super_block * sb,struct fs_context * fc)878 static int ext2_fill_super(struct super_block *sb, struct fs_context *fc)
879 {
880 struct ext2_fs_context *ctx = fc->fs_private;
881 int silent = fc->sb_flags & SB_SILENT;
882 struct buffer_head * bh;
883 struct ext2_sb_info * sbi;
884 struct ext2_super_block * es;
885 struct inode *root;
886 unsigned long block;
887 unsigned long sb_block = ctx->s_sb_block;
888 unsigned long logic_sb_block;
889 unsigned long offset = 0;
890 long ret = -ENOMEM;
891 int blocksize = BLOCK_SIZE;
892 int db_count;
893 int i, j;
894 __le32 features;
895 int err;
896
897 sbi = kzalloc_obj(*sbi);
898 if (!sbi)
899 return -ENOMEM;
900
901 sbi->s_blockgroup_lock =
902 kzalloc_obj(struct blockgroup_lock);
903 if (!sbi->s_blockgroup_lock) {
904 kfree(sbi);
905 return -ENOMEM;
906 }
907 sb->s_fs_info = sbi;
908 sbi->s_sb_block = sb_block;
909 sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
910 NULL, NULL);
911
912 spin_lock_init(&sbi->s_lock);
913 ret = -EINVAL;
914
915 /*
916 * See what the current blocksize for the device is, and
917 * use that as the blocksize. Otherwise (or if the blocksize
918 * is smaller than the default) use the default.
919 * This is important for devices that have a hardware
920 * sectorsize that is larger than the default.
921 */
922 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
923 if (!blocksize) {
924 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
925 goto failed_sbi;
926 }
927
928 /*
929 * If the superblock doesn't start on a hardware sector boundary,
930 * calculate the offset.
931 */
932 if (blocksize != BLOCK_SIZE) {
933 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
934 offset = (sb_block*BLOCK_SIZE) % blocksize;
935 } else {
936 logic_sb_block = sb_block;
937 }
938
939 if (!(bh = sb_bread(sb, logic_sb_block))) {
940 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
941 goto failed_sbi;
942 }
943 /*
944 * Note: s_es must be initialized as soon as possible because
945 * some ext2 macro-instructions depend on its value
946 */
947 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
948 sbi->s_es = es;
949 sb->s_magic = le16_to_cpu(es->s_magic);
950
951 if (sb->s_magic != EXT2_SUPER_MAGIC)
952 goto cantfind_ext2;
953
954 ext2_set_options(fc, sbi);
955
956 sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
957 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
958 sb->s_iflags |= SB_I_CGROUPWB;
959
960 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
961 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
962 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
963 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
964 ext2_msg(sb, KERN_WARNING,
965 "warning: feature flags set on rev 0 fs, "
966 "running e2fsck is recommended");
967 /*
968 * Check feature flags regardless of the revision level, since we
969 * previously didn't change the revision level when setting the flags,
970 * so there is a chance incompat flags are set on a rev 0 filesystem.
971 */
972 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
973 if (features) {
974 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
975 "unsupported optional features (%x)",
976 le32_to_cpu(features));
977 goto failed_mount;
978 }
979 if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
980 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
981 "unsupported optional features (%x)",
982 le32_to_cpu(features));
983 goto failed_mount;
984 }
985
986 if (le32_to_cpu(es->s_log_block_size) >
987 (EXT2_MAX_BLOCK_LOG_SIZE - BLOCK_SIZE_BITS)) {
988 ext2_msg(sb, KERN_ERR,
989 "Invalid log block size: %u",
990 le32_to_cpu(es->s_log_block_size));
991 goto failed_mount;
992 }
993 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
994
995 if (test_opt(sb, DAX)) {
996 if (!sbi->s_daxdev) {
997 ext2_msg(sb, KERN_ERR,
998 "DAX unsupported by block device. Turning off DAX.");
999 clear_opt(sbi->s_mount_opt, DAX);
1000 } else if (blocksize != PAGE_SIZE) {
1001 ext2_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
1002 clear_opt(sbi->s_mount_opt, DAX);
1003 }
1004 }
1005
1006 /* If the blocksize doesn't match, re-read the thing.. */
1007 if (sb->s_blocksize != blocksize) {
1008 brelse(bh);
1009
1010 if (!sb_set_blocksize(sb, blocksize)) {
1011 ext2_msg(sb, KERN_ERR,
1012 "error: bad blocksize %d", blocksize);
1013 goto failed_sbi;
1014 }
1015
1016 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
1017 offset = (sb_block*BLOCK_SIZE) % blocksize;
1018 bh = sb_bread(sb, logic_sb_block);
1019 if(!bh) {
1020 ext2_msg(sb, KERN_ERR, "error: couldn't read"
1021 "superblock on 2nd try");
1022 goto failed_sbi;
1023 }
1024 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
1025 sbi->s_es = es;
1026 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
1027 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
1028 goto failed_mount;
1029 }
1030 }
1031
1032 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
1033 sb->s_max_links = EXT2_LINK_MAX;
1034 sb->s_time_min = S32_MIN;
1035 sb->s_time_max = S32_MAX;
1036
1037 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
1038 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
1039 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
1040 } else {
1041 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1042 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1043 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
1044 !is_power_of_2(sbi->s_inode_size) ||
1045 (sbi->s_inode_size > blocksize)) {
1046 ext2_msg(sb, KERN_ERR,
1047 "error: unsupported inode size: %d",
1048 sbi->s_inode_size);
1049 goto failed_mount;
1050 }
1051 }
1052
1053 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1054 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1055
1056 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1057 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1058 goto cantfind_ext2;
1059 sbi->s_itb_per_group = sbi->s_inodes_per_group /
1060 sbi->s_inodes_per_block;
1061 sbi->s_desc_per_block = sb->s_blocksize /
1062 sizeof (struct ext2_group_desc);
1063 sbi->s_sbh = bh;
1064 sbi->s_mount_state = le16_to_cpu(es->s_state);
1065 sbi->s_addr_per_block_bits =
1066 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1067 sbi->s_desc_per_block_bits =
1068 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1069
1070 if (sb->s_magic != EXT2_SUPER_MAGIC)
1071 goto cantfind_ext2;
1072
1073 if (sb->s_blocksize != bh->b_size) {
1074 if (!silent)
1075 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1076 goto failed_mount;
1077 }
1078
1079 if (es->s_log_frag_size != es->s_log_block_size) {
1080 ext2_msg(sb, KERN_ERR,
1081 "error: fragsize log %u != blocksize log %u",
1082 le32_to_cpu(es->s_log_frag_size), sb->s_blocksize_bits);
1083 goto failed_mount;
1084 }
1085
1086 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1087 ext2_msg(sb, KERN_ERR,
1088 "error: #blocks per group too big: %lu",
1089 sbi->s_blocks_per_group);
1090 goto failed_mount;
1091 }
1092 /* At least inode table, bitmaps, and sb have to fit in one group */
1093 if (sbi->s_blocks_per_group <= sbi->s_itb_per_group + 3) {
1094 ext2_msg(sb, KERN_ERR,
1095 "error: #blocks per group smaller than metadata size: %lu <= %lu",
1096 sbi->s_blocks_per_group, sbi->s_inodes_per_group + 3);
1097 goto failed_mount;
1098 }
1099 if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
1100 sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1101 ext2_msg(sb, KERN_ERR,
1102 "error: invalid #inodes per group: %lu",
1103 sbi->s_inodes_per_group);
1104 goto failed_mount;
1105 }
1106 if (sb_bdev_nr_blocks(sb) < le32_to_cpu(es->s_blocks_count)) {
1107 ext2_msg(sb, KERN_ERR,
1108 "bad geometry: block count %u exceeds size of device (%u blocks)",
1109 le32_to_cpu(es->s_blocks_count),
1110 (unsigned)sb_bdev_nr_blocks(sb));
1111 goto failed_mount;
1112 }
1113
1114 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1115 le32_to_cpu(es->s_first_data_block) - 1)
1116 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1117 if ((u64)sbi->s_groups_count * sbi->s_inodes_per_group !=
1118 le32_to_cpu(es->s_inodes_count)) {
1119 ext2_msg(sb, KERN_ERR, "error: invalid #inodes: %u vs computed %llu",
1120 le32_to_cpu(es->s_inodes_count),
1121 (u64)sbi->s_groups_count * sbi->s_inodes_per_group);
1122 goto failed_mount;
1123 }
1124 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1125 EXT2_DESC_PER_BLOCK(sb);
1126 sbi->s_group_desc = kvmalloc_objs(struct buffer_head *, db_count);
1127 if (sbi->s_group_desc == NULL) {
1128 ret = -ENOMEM;
1129 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1130 goto failed_mount;
1131 }
1132 bgl_lock_init(sbi->s_blockgroup_lock);
1133 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1134 if (!sbi->s_debts) {
1135 ret = -ENOMEM;
1136 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1137 goto failed_mount_group_desc;
1138 }
1139 for (i = 0; i < db_count; i++) {
1140 block = descriptor_loc(sb, logic_sb_block, i);
1141 sbi->s_group_desc[i] = sb_bread(sb, block);
1142 if (!sbi->s_group_desc[i]) {
1143 for (j = 0; j < i; j++)
1144 brelse (sbi->s_group_desc[j]);
1145 ext2_msg(sb, KERN_ERR,
1146 "error: unable to read group descriptors");
1147 goto failed_mount_group_desc;
1148 }
1149 }
1150 if (!ext2_check_descriptors (sb)) {
1151 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1152 goto failed_mount2;
1153 }
1154 sbi->s_gdb_count = db_count;
1155 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1156 spin_lock_init(&sbi->s_next_gen_lock);
1157
1158 /* per filesystem reservation list head & lock */
1159 spin_lock_init(&sbi->s_rsv_window_lock);
1160 sbi->s_rsv_window_root = RB_ROOT;
1161 /*
1162 * Add a single, static dummy reservation to the start of the
1163 * reservation window list --- it gives us a placeholder for
1164 * append-at-start-of-list which makes the allocation logic
1165 * _much_ simpler.
1166 */
1167 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1168 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1169 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1170 sbi->s_rsv_window_head.rsv_goal_size = 0;
1171 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1172
1173 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1174 ext2_count_free_blocks(sb), GFP_KERNEL);
1175 if (!err) {
1176 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1177 ext2_count_free_inodes(sb), GFP_KERNEL);
1178 }
1179 if (!err) {
1180 err = percpu_counter_init(&sbi->s_dirs_counter,
1181 ext2_count_dirs(sb), GFP_KERNEL);
1182 }
1183 if (err) {
1184 ret = err;
1185 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1186 goto failed_mount3;
1187 }
1188
1189 #ifdef CONFIG_EXT2_FS_XATTR
1190 sbi->s_ea_block_cache = ext2_xattr_create_cache();
1191 if (!sbi->s_ea_block_cache) {
1192 ret = -ENOMEM;
1193 ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1194 goto failed_mount3;
1195 }
1196 #endif
1197 /*
1198 * set up enough so that it can read an inode
1199 */
1200 sb->s_op = &ext2_sops;
1201 sb->s_export_op = &ext2_export_ops;
1202 sb->s_xattr = ext2_xattr_handlers;
1203
1204 #ifdef CONFIG_QUOTA
1205 sb->dq_op = &dquot_operations;
1206 sb->s_qcop = &ext2_quotactl_ops;
1207 sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1208 #endif
1209
1210 root = ext2_iget(sb, EXT2_ROOT_INO);
1211 if (IS_ERR(root)) {
1212 ret = PTR_ERR(root);
1213 goto failed_mount3;
1214 }
1215 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1216 iput(root);
1217 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1218 goto failed_mount3;
1219 }
1220
1221 sb->s_root = d_make_root(root);
1222 if (!sb->s_root) {
1223 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1224 ret = -ENOMEM;
1225 goto failed_mount3;
1226 }
1227 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1228 ext2_msg(sb, KERN_WARNING,
1229 "warning: mounting ext3 filesystem as ext2");
1230 if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1231 sb->s_flags |= SB_RDONLY;
1232 ext2_write_super(sb);
1233 return 0;
1234
1235 cantfind_ext2:
1236 if (!silent)
1237 ext2_msg(sb, KERN_ERR,
1238 "error: can't find an ext2 filesystem on dev %s.",
1239 sb->s_id);
1240 goto failed_mount;
1241 failed_mount3:
1242 ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1243 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1244 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1245 percpu_counter_destroy(&sbi->s_dirs_counter);
1246 failed_mount2:
1247 for (i = 0; i < db_count; i++)
1248 brelse(sbi->s_group_desc[i]);
1249 failed_mount_group_desc:
1250 kvfree(sbi->s_group_desc);
1251 kfree(sbi->s_debts);
1252 failed_mount:
1253 brelse(bh);
1254 failed_sbi:
1255 fs_put_dax(sbi->s_daxdev, NULL);
1256 sb->s_fs_info = NULL;
1257 kfree(sbi->s_blockgroup_lock);
1258 kfree(sbi);
1259 return ret;
1260 }
1261
ext2_clear_super_error(struct super_block * sb)1262 static void ext2_clear_super_error(struct super_block *sb)
1263 {
1264 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1265
1266 if (buffer_write_io_error(sbh)) {
1267 /*
1268 * Oh, dear. A previous attempt to write the
1269 * superblock failed. This could happen because the
1270 * USB device was yanked out. Or it could happen to
1271 * be a transient write error and maybe the block will
1272 * be remapped. Nothing we can do but to retry the
1273 * write and hope for the best.
1274 */
1275 ext2_msg(sb, KERN_ERR,
1276 "previous I/O error to superblock detected");
1277 clear_buffer_write_io_error(sbh);
1278 set_buffer_uptodate(sbh);
1279 }
1280 }
1281
ext2_sync_super(struct super_block * sb,struct ext2_super_block * es,int wait)1282 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1283 int wait)
1284 {
1285 ext2_clear_super_error(sb);
1286 spin_lock(&EXT2_SB(sb)->s_lock);
1287 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1288 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1289 es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1290 /* unlock before we do IO */
1291 spin_unlock(&EXT2_SB(sb)->s_lock);
1292 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1293 if (wait)
1294 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1295 }
1296
1297 /*
1298 * In the second extended file system, it is not necessary to
1299 * write the super block since we use a mapping of the
1300 * disk super block in a buffer.
1301 *
1302 * However, this function is still used to set the fs valid
1303 * flags to 0. We need to set this flag to 0 since the fs
1304 * may have been checked while mounted and e2fsck may have
1305 * set s_state to EXT2_VALID_FS after some corrections.
1306 */
ext2_sync_fs(struct super_block * sb,int wait)1307 static int ext2_sync_fs(struct super_block *sb, int wait)
1308 {
1309 struct ext2_sb_info *sbi = EXT2_SB(sb);
1310 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1311
1312 /*
1313 * Write quota structures to quota file, sync_blockdev() will write
1314 * them to disk later
1315 */
1316 dquot_writeback_dquots(sb, -1);
1317
1318 spin_lock(&sbi->s_lock);
1319 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1320 ext2_debug("setting valid to 0\n");
1321 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1322 }
1323 spin_unlock(&sbi->s_lock);
1324 ext2_sync_super(sb, es, wait);
1325 return 0;
1326 }
1327
ext2_freeze(struct super_block * sb)1328 static int ext2_freeze(struct super_block *sb)
1329 {
1330 struct ext2_sb_info *sbi = EXT2_SB(sb);
1331
1332 /*
1333 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1334 * because we have unattached inodes and thus filesystem is not fully
1335 * consistent.
1336 */
1337 if (atomic_long_read(&sb->s_remove_count)) {
1338 ext2_sync_fs(sb, 1);
1339 return 0;
1340 }
1341 /* Set EXT2_FS_VALID flag */
1342 spin_lock(&sbi->s_lock);
1343 sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1344 spin_unlock(&sbi->s_lock);
1345 ext2_sync_super(sb, sbi->s_es, 1);
1346
1347 return 0;
1348 }
1349
ext2_unfreeze(struct super_block * sb)1350 static int ext2_unfreeze(struct super_block *sb)
1351 {
1352 /* Just write sb to clear EXT2_VALID_FS flag */
1353 ext2_write_super(sb);
1354
1355 return 0;
1356 }
1357
ext2_write_super(struct super_block * sb)1358 static void ext2_write_super(struct super_block *sb)
1359 {
1360 if (!sb_rdonly(sb))
1361 ext2_sync_fs(sb, 1);
1362 }
1363
ext2_reconfigure(struct fs_context * fc)1364 static int ext2_reconfigure(struct fs_context *fc)
1365 {
1366 struct ext2_fs_context *ctx = fc->fs_private;
1367 struct super_block *sb = fc->root->d_sb;
1368 struct ext2_sb_info * sbi = EXT2_SB(sb);
1369 struct ext2_super_block * es;
1370 struct ext2_mount_options new_opts;
1371 int flags = fc->sb_flags;
1372 int err;
1373
1374 sync_filesystem(sb);
1375
1376 new_opts.s_mount_opt = ctx->vals_s_mount_opt;
1377 new_opts.s_resuid = ctx->s_resuid;
1378 new_opts.s_resgid = ctx->s_resgid;
1379
1380 spin_lock(&sbi->s_lock);
1381 es = sbi->s_es;
1382 if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1383 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1384 "dax flag with busy inodes while remounting");
1385 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1386 }
1387 if ((bool)(flags & SB_RDONLY) == sb_rdonly(sb))
1388 goto out_set;
1389 if (flags & SB_RDONLY) {
1390 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1391 !(sbi->s_mount_state & EXT2_VALID_FS))
1392 goto out_set;
1393
1394 /*
1395 * OK, we are remounting a valid rw partition rdonly, so set
1396 * the rdonly flag and then mark the partition as valid again.
1397 */
1398 es->s_state = cpu_to_le16(sbi->s_mount_state);
1399 es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1400 spin_unlock(&sbi->s_lock);
1401
1402 err = dquot_suspend(sb, -1);
1403 if (err < 0)
1404 return err;
1405
1406 ext2_sync_super(sb, es, 1);
1407 } else {
1408 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1409 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1410 if (ret) {
1411 spin_unlock(&sbi->s_lock);
1412 ext2_msg(sb, KERN_WARNING,
1413 "warning: couldn't remount RDWR because of "
1414 "unsupported optional features (%x).",
1415 le32_to_cpu(ret));
1416 return -EROFS;
1417 }
1418 /*
1419 * Mounting a RDONLY partition read-write, so reread and
1420 * store the current valid flag. (It may have been changed
1421 * by e2fsck since we originally mounted the partition.)
1422 */
1423 sbi->s_mount_state = le16_to_cpu(es->s_state);
1424 if (!ext2_setup_super (sb, es, 0))
1425 sb->s_flags &= ~SB_RDONLY;
1426 spin_unlock(&sbi->s_lock);
1427
1428 ext2_write_super(sb);
1429
1430 dquot_resume(sb, -1);
1431 }
1432
1433 spin_lock(&sbi->s_lock);
1434 out_set:
1435 sbi->s_mount_opt = new_opts.s_mount_opt;
1436 sbi->s_resuid = new_opts.s_resuid;
1437 sbi->s_resgid = new_opts.s_resgid;
1438 sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1439 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
1440 spin_unlock(&sbi->s_lock);
1441
1442 return 0;
1443 }
1444
ext2_statfs(struct dentry * dentry,struct kstatfs * buf)1445 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1446 {
1447 struct super_block *sb = dentry->d_sb;
1448 struct ext2_sb_info *sbi = EXT2_SB(sb);
1449 struct ext2_super_block *es = sbi->s_es;
1450
1451 spin_lock(&sbi->s_lock);
1452
1453 if (test_opt (sb, MINIX_DF))
1454 sbi->s_overhead_last = 0;
1455 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1456 unsigned long i, overhead = 0;
1457 smp_rmb();
1458
1459 /*
1460 * Compute the overhead (FS structures). This is constant
1461 * for a given filesystem unless the number of block groups
1462 * changes so we cache the previous value until it does.
1463 */
1464
1465 /*
1466 * All of the blocks before first_data_block are
1467 * overhead
1468 */
1469 overhead = le32_to_cpu(es->s_first_data_block);
1470
1471 /*
1472 * Add the overhead attributed to the superblock and
1473 * block group descriptors. If the sparse superblocks
1474 * feature is turned on, then not all groups have this.
1475 */
1476 for (i = 0; i < sbi->s_groups_count; i++)
1477 overhead += ext2_bg_has_super(sb, i) +
1478 ext2_bg_num_gdb(sb, i);
1479
1480 /*
1481 * Every block group has an inode bitmap, a block
1482 * bitmap, and an inode table.
1483 */
1484 overhead += (sbi->s_groups_count *
1485 (2 + sbi->s_itb_per_group));
1486 sbi->s_overhead_last = overhead;
1487 smp_wmb();
1488 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1489 }
1490
1491 buf->f_type = EXT2_SUPER_MAGIC;
1492 buf->f_bsize = sb->s_blocksize;
1493 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1494 buf->f_bfree = ext2_count_free_blocks(sb);
1495 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1496 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1497 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1498 buf->f_bavail = 0;
1499 buf->f_files = le32_to_cpu(es->s_inodes_count);
1500 buf->f_ffree = ext2_count_free_inodes(sb);
1501 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1502 buf->f_namelen = EXT2_NAME_LEN;
1503 buf->f_fsid = uuid_to_fsid(es->s_uuid);
1504 spin_unlock(&sbi->s_lock);
1505 return 0;
1506 }
1507
ext2_get_tree(struct fs_context * fc)1508 static int ext2_get_tree(struct fs_context *fc)
1509 {
1510 return get_tree_bdev(fc, ext2_fill_super);
1511 }
1512
1513 #ifdef CONFIG_QUOTA
1514
1515 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1516 * acquiring the locks... As quota files are never truncated and quota code
1517 * itself serializes the operations (and no one else should touch the files)
1518 * 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)1519 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1520 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 toread;
1528 struct buffer_head tmp_bh;
1529 struct buffer_head *bh;
1530 loff_t i_size = i_size_read(inode);
1531
1532 if (off > i_size)
1533 return 0;
1534 if (off+len > i_size)
1535 len = i_size-off;
1536 toread = len;
1537 while (toread > 0) {
1538 tocopy = min_t(size_t, sb->s_blocksize - offset, toread);
1539
1540 tmp_bh.b_state = 0;
1541 tmp_bh.b_size = sb->s_blocksize;
1542 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1543 if (err < 0)
1544 return err;
1545 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1546 memset(data, 0, tocopy);
1547 else {
1548 bh = sb_bread(sb, tmp_bh.b_blocknr);
1549 if (!bh)
1550 return -EIO;
1551 memcpy(data, bh->b_data+offset, tocopy);
1552 brelse(bh);
1553 }
1554 offset = 0;
1555 toread -= tocopy;
1556 data += tocopy;
1557 blk++;
1558 }
1559 return len;
1560 }
1561
1562 /* Write to quotafile */
ext2_quota_write(struct super_block * sb,int type,const char * data,size_t len,loff_t off)1563 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1564 const char *data, size_t len, loff_t off)
1565 {
1566 struct inode *inode = sb_dqopt(sb)->files[type];
1567 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1568 int err = 0;
1569 int offset = off & (sb->s_blocksize - 1);
1570 int tocopy;
1571 size_t towrite = len;
1572 struct buffer_head tmp_bh;
1573 struct buffer_head *bh;
1574
1575 while (towrite > 0) {
1576 tocopy = min_t(size_t, sb->s_blocksize - offset, towrite);
1577
1578 tmp_bh.b_state = 0;
1579 tmp_bh.b_size = sb->s_blocksize;
1580 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1581 if (err < 0)
1582 goto out;
1583 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1584 bh = sb_bread(sb, tmp_bh.b_blocknr);
1585 else
1586 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1587 if (unlikely(!bh)) {
1588 err = -EIO;
1589 goto out;
1590 }
1591 lock_buffer(bh);
1592 memcpy(bh->b_data+offset, data, tocopy);
1593 flush_dcache_folio(bh->b_folio);
1594 set_buffer_uptodate(bh);
1595 mark_buffer_dirty(bh);
1596 unlock_buffer(bh);
1597 brelse(bh);
1598 offset = 0;
1599 towrite -= tocopy;
1600 data += tocopy;
1601 blk++;
1602 }
1603 out:
1604 if (len == towrite)
1605 return err;
1606 if (inode->i_size < off+len-towrite)
1607 i_size_write(inode, off+len-towrite);
1608 inode_inc_iversion(inode);
1609 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
1610 mark_inode_dirty(inode);
1611 return len - towrite;
1612 }
1613
ext2_quota_on(struct super_block * sb,int type,int format_id,const struct path * path)1614 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1615 const struct path *path)
1616 {
1617 int err;
1618 struct inode *inode;
1619
1620 err = dquot_quota_on(sb, type, format_id, path);
1621 if (err)
1622 return err;
1623
1624 inode = d_inode(path->dentry);
1625 inode_lock(inode);
1626 EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1627 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1628 S_NOATIME | S_IMMUTABLE);
1629 inode_unlock(inode);
1630 mark_inode_dirty(inode);
1631
1632 return 0;
1633 }
1634
ext2_quota_off(struct super_block * sb,int type)1635 static int ext2_quota_off(struct super_block *sb, int type)
1636 {
1637 struct inode *inode = sb_dqopt(sb)->files[type];
1638 int err;
1639
1640 if (!inode || !igrab(inode))
1641 goto out;
1642
1643 err = dquot_quota_off(sb, type);
1644 if (err)
1645 goto out_put;
1646
1647 inode_lock(inode);
1648 EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1649 inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1650 inode_unlock(inode);
1651 mark_inode_dirty(inode);
1652 out_put:
1653 iput(inode);
1654 return err;
1655 out:
1656 return dquot_quota_off(sb, type);
1657 }
1658
1659 #endif
1660
1661 static const struct fs_context_operations ext2_context_ops = {
1662 .parse_param = ext2_parse_param,
1663 .get_tree = ext2_get_tree,
1664 .reconfigure = ext2_reconfigure,
1665 .free = ext2_free_fc,
1666 };
1667
ext2_init_fs_context(struct fs_context * fc)1668 static int ext2_init_fs_context(struct fs_context *fc)
1669 {
1670 struct ext2_fs_context *ctx;
1671
1672 ctx = kzalloc_obj(*ctx);
1673 if (!ctx)
1674 return -ENOMEM;
1675
1676 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
1677 struct super_block *sb = fc->root->d_sb;
1678 struct ext2_sb_info *sbi = EXT2_SB(sb);
1679
1680 spin_lock(&sbi->s_lock);
1681 ctx->vals_s_mount_opt = sbi->s_mount_opt;
1682 ctx->vals_s_flags = sb->s_flags;
1683 ctx->s_resuid = sbi->s_resuid;
1684 ctx->s_resgid = sbi->s_resgid;
1685 spin_unlock(&sbi->s_lock);
1686 } else {
1687 ctx->s_sb_block = 1;
1688 ctx_set_mount_opt(ctx, EXT2_MOUNT_RESERVATION);
1689 }
1690
1691 fc->fs_private = ctx;
1692 fc->ops = &ext2_context_ops;
1693
1694 return 0;
1695 }
1696
1697 static struct file_system_type ext2_fs_type = {
1698 .owner = THIS_MODULE,
1699 .name = "ext2",
1700 .kill_sb = kill_block_super,
1701 .fs_flags = FS_REQUIRES_DEV,
1702 .init_fs_context = ext2_init_fs_context,
1703 .parameters = ext2_param_spec,
1704 };
1705 MODULE_ALIAS_FS("ext2");
1706
init_ext2_fs(void)1707 static int __init init_ext2_fs(void)
1708 {
1709 int err;
1710
1711 err = init_inodecache();
1712 if (err)
1713 return err;
1714 err = register_filesystem(&ext2_fs_type);
1715 if (err)
1716 goto out;
1717 return 0;
1718 out:
1719 destroy_inodecache();
1720 return err;
1721 }
1722
exit_ext2_fs(void)1723 static void __exit exit_ext2_fs(void)
1724 {
1725 unregister_filesystem(&ext2_fs_type);
1726 destroy_inodecache();
1727 }
1728
1729 MODULE_AUTHOR("Remy Card and others");
1730 MODULE_DESCRIPTION("Second Extended Filesystem");
1731 MODULE_LICENSE("GPL");
1732 module_init(init_ext2_fs)
1733 module_exit(exit_ext2_fs)
1734