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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_nocheck, 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_nocheck, "check=none"},
455 	{Opt_nocheck, "nocheck"},
456 	{Opt_debug, "debug"},
457 	{Opt_oldalloc, "oldalloc"},
458 	{Opt_orlov, "orlov"},
459 	{Opt_nobh, "nobh"},
460 	{Opt_user_xattr, "user_xattr"},
461 	{Opt_nouser_xattr, "nouser_xattr"},
462 	{Opt_acl, "acl"},
463 	{Opt_noacl, "noacl"},
464 	{Opt_xip, "xip"},
465 	{Opt_dax, "dax"},
466 	{Opt_grpquota, "grpquota"},
467 	{Opt_ignore, "noquota"},
468 	{Opt_quota, "quota"},
469 	{Opt_usrquota, "usrquota"},
470 	{Opt_reservation, "reservation"},
471 	{Opt_noreservation, "noreservation"},
472 	{Opt_err, NULL}
473 };
474 
parse_options(char * options,struct super_block * sb,struct ext2_mount_options * opts)475 static int parse_options(char *options, struct super_block *sb,
476 			 struct ext2_mount_options *opts)
477 {
478 	char *p;
479 	substring_t args[MAX_OPT_ARGS];
480 	int option;
481 	kuid_t uid;
482 	kgid_t gid;
483 
484 	if (!options)
485 		return 1;
486 
487 	while ((p = strsep (&options, ",")) != NULL) {
488 		int token;
489 		if (!*p)
490 			continue;
491 
492 		token = match_token(p, tokens, args);
493 		switch (token) {
494 		case Opt_bsd_df:
495 			clear_opt (opts->s_mount_opt, MINIX_DF);
496 			break;
497 		case Opt_minix_df:
498 			set_opt (opts->s_mount_opt, MINIX_DF);
499 			break;
500 		case Opt_grpid:
501 			set_opt (opts->s_mount_opt, GRPID);
502 			break;
503 		case Opt_nogrpid:
504 			clear_opt (opts->s_mount_opt, GRPID);
505 			break;
506 		case Opt_resuid:
507 			if (match_int(&args[0], &option))
508 				return 0;
509 			uid = make_kuid(current_user_ns(), option);
510 			if (!uid_valid(uid)) {
511 				ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
512 				return 0;
513 
514 			}
515 			opts->s_resuid = uid;
516 			break;
517 		case Opt_resgid:
518 			if (match_int(&args[0], &option))
519 				return 0;
520 			gid = make_kgid(current_user_ns(), option);
521 			if (!gid_valid(gid)) {
522 				ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
523 				return 0;
524 			}
525 			opts->s_resgid = gid;
526 			break;
527 		case Opt_sb:
528 			/* handled by get_sb_block() instead of here */
529 			/* *sb_block = match_int(&args[0]); */
530 			break;
531 		case Opt_err_panic:
532 			clear_opt (opts->s_mount_opt, ERRORS_CONT);
533 			clear_opt (opts->s_mount_opt, ERRORS_RO);
534 			set_opt (opts->s_mount_opt, ERRORS_PANIC);
535 			break;
536 		case Opt_err_ro:
537 			clear_opt (opts->s_mount_opt, ERRORS_CONT);
538 			clear_opt (opts->s_mount_opt, ERRORS_PANIC);
539 			set_opt (opts->s_mount_opt, ERRORS_RO);
540 			break;
541 		case Opt_err_cont:
542 			clear_opt (opts->s_mount_opt, ERRORS_RO);
543 			clear_opt (opts->s_mount_opt, ERRORS_PANIC);
544 			set_opt (opts->s_mount_opt, ERRORS_CONT);
545 			break;
546 		case Opt_nouid32:
547 			set_opt (opts->s_mount_opt, NO_UID32);
548 			break;
549 		case Opt_nocheck:
550 			ext2_msg(sb, KERN_WARNING,
551 				"Option nocheck/check=none is deprecated and"
552 				" will be removed in June 2020.");
553 			clear_opt (opts->s_mount_opt, CHECK);
554 			break;
555 		case Opt_debug:
556 			set_opt (opts->s_mount_opt, DEBUG);
557 			break;
558 		case Opt_oldalloc:
559 			set_opt (opts->s_mount_opt, OLDALLOC);
560 			break;
561 		case Opt_orlov:
562 			clear_opt (opts->s_mount_opt, OLDALLOC);
563 			break;
564 		case Opt_nobh:
565 			set_opt (opts->s_mount_opt, NOBH);
566 			break;
567 #ifdef CONFIG_EXT2_FS_XATTR
568 		case Opt_user_xattr:
569 			set_opt (opts->s_mount_opt, XATTR_USER);
570 			break;
571 		case Opt_nouser_xattr:
572 			clear_opt (opts->s_mount_opt, XATTR_USER);
573 			break;
574 #else
575 		case Opt_user_xattr:
576 		case Opt_nouser_xattr:
577 			ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
578 				"not supported");
579 			break;
580 #endif
581 #ifdef CONFIG_EXT2_FS_POSIX_ACL
582 		case Opt_acl:
583 			set_opt(opts->s_mount_opt, POSIX_ACL);
584 			break;
585 		case Opt_noacl:
586 			clear_opt(opts->s_mount_opt, POSIX_ACL);
587 			break;
588 #else
589 		case Opt_acl:
590 		case Opt_noacl:
591 			ext2_msg(sb, KERN_INFO,
592 				"(no)acl options not supported");
593 			break;
594 #endif
595 		case Opt_xip:
596 			ext2_msg(sb, KERN_INFO, "use dax instead of xip");
597 			set_opt(opts->s_mount_opt, XIP);
598 			/* Fall through */
599 		case Opt_dax:
600 #ifdef CONFIG_FS_DAX
601 			ext2_msg(sb, KERN_WARNING,
602 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
603 			set_opt(opts->s_mount_opt, DAX);
604 #else
605 			ext2_msg(sb, KERN_INFO, "dax option not supported");
606 #endif
607 			break;
608 
609 #if defined(CONFIG_QUOTA)
610 		case Opt_quota:
611 		case Opt_usrquota:
612 			set_opt(opts->s_mount_opt, USRQUOTA);
613 			break;
614 
615 		case Opt_grpquota:
616 			set_opt(opts->s_mount_opt, GRPQUOTA);
617 			break;
618 #else
619 		case Opt_quota:
620 		case Opt_usrquota:
621 		case Opt_grpquota:
622 			ext2_msg(sb, KERN_INFO,
623 				"quota operations not supported");
624 			break;
625 #endif
626 
627 		case Opt_reservation:
628 			set_opt(opts->s_mount_opt, RESERVATION);
629 			ext2_msg(sb, KERN_INFO, "reservations ON");
630 			break;
631 		case Opt_noreservation:
632 			clear_opt(opts->s_mount_opt, RESERVATION);
633 			ext2_msg(sb, KERN_INFO, "reservations OFF");
634 			break;
635 		case Opt_ignore:
636 			break;
637 		default:
638 			return 0;
639 		}
640 	}
641 	return 1;
642 }
643 
ext2_setup_super(struct super_block * sb,struct ext2_super_block * es,int read_only)644 static int ext2_setup_super (struct super_block * sb,
645 			      struct ext2_super_block * es,
646 			      int read_only)
647 {
648 	int res = 0;
649 	struct ext2_sb_info *sbi = EXT2_SB(sb);
650 
651 	if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
652 		ext2_msg(sb, KERN_ERR,
653 			"error: revision level too high, "
654 			"forcing read-only mode");
655 		res = SB_RDONLY;
656 	}
657 	if (read_only)
658 		return res;
659 	if (!(sbi->s_mount_state & EXT2_VALID_FS))
660 		ext2_msg(sb, KERN_WARNING,
661 			"warning: mounting unchecked fs, "
662 			"running e2fsck is recommended");
663 	else if ((sbi->s_mount_state & EXT2_ERROR_FS))
664 		ext2_msg(sb, KERN_WARNING,
665 			"warning: mounting fs with errors, "
666 			"running e2fsck is recommended");
667 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
668 		 le16_to_cpu(es->s_mnt_count) >=
669 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
670 		ext2_msg(sb, KERN_WARNING,
671 			"warning: maximal mount count reached, "
672 			"running e2fsck is recommended");
673 	else if (le32_to_cpu(es->s_checkinterval) &&
674 		(le32_to_cpu(es->s_lastcheck) +
675 			le32_to_cpu(es->s_checkinterval) <=
676 			ktime_get_real_seconds()))
677 		ext2_msg(sb, KERN_WARNING,
678 			"warning: checktime reached, "
679 			"running e2fsck is recommended");
680 	if (!le16_to_cpu(es->s_max_mnt_count))
681 		es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
682 	le16_add_cpu(&es->s_mnt_count, 1);
683 	if (test_opt (sb, DEBUG))
684 		ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, gc=%lu, "
685 			"bpg=%lu, ipg=%lu, mo=%04lx]",
686 			EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
687 			sbi->s_groups_count,
688 			EXT2_BLOCKS_PER_GROUP(sb),
689 			EXT2_INODES_PER_GROUP(sb),
690 			sbi->s_mount_opt);
691 	return res;
692 }
693 
ext2_check_descriptors(struct super_block * sb)694 static int ext2_check_descriptors(struct super_block *sb)
695 {
696 	int i;
697 	struct ext2_sb_info *sbi = EXT2_SB(sb);
698 
699 	ext2_debug ("Checking group descriptors");
700 
701 	for (i = 0; i < sbi->s_groups_count; i++) {
702 		struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
703 		ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
704 		ext2_fsblk_t last_block;
705 
706 		if (i == sbi->s_groups_count - 1)
707 			last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
708 		else
709 			last_block = first_block +
710 				(EXT2_BLOCKS_PER_GROUP(sb) - 1);
711 
712 		if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
713 		    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
714 		{
715 			ext2_error (sb, "ext2_check_descriptors",
716 				    "Block bitmap for group %d"
717 				    " not in group (block %lu)!",
718 				    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
719 			return 0;
720 		}
721 		if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
722 		    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
723 		{
724 			ext2_error (sb, "ext2_check_descriptors",
725 				    "Inode bitmap for group %d"
726 				    " not in group (block %lu)!",
727 				    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
728 			return 0;
729 		}
730 		if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
731 		    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
732 		    last_block)
733 		{
734 			ext2_error (sb, "ext2_check_descriptors",
735 				    "Inode table for group %d"
736 				    " not in group (block %lu)!",
737 				    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
738 			return 0;
739 		}
740 	}
741 	return 1;
742 }
743 
744 /*
745  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
746  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
747  * We need to be 1 filesystem block less than the 2^32 sector limit.
748  */
ext2_max_size(int bits)749 static loff_t ext2_max_size(int bits)
750 {
751 	loff_t res = EXT2_NDIR_BLOCKS;
752 	int meta_blocks;
753 	unsigned int upper_limit;
754 	unsigned int ppb = 1 << (bits-2);
755 
756 	/* This is calculated to be the largest file size for a
757 	 * dense, file such that the total number of
758 	 * sectors in the file, including data and all indirect blocks,
759 	 * does not exceed 2^32 -1
760 	 * __u32 i_blocks representing the total number of
761 	 * 512 bytes blocks of the file
762 	 */
763 	upper_limit = (1LL << 32) - 1;
764 
765 	/* total blocks in file system block size */
766 	upper_limit >>= (bits - 9);
767 
768 	/* Compute how many blocks we can address by block tree */
769 	res += 1LL << (bits-2);
770 	res += 1LL << (2*(bits-2));
771 	res += 1LL << (3*(bits-2));
772 	/* Compute how many metadata blocks are needed */
773 	meta_blocks = 1;
774 	meta_blocks += 1 + ppb;
775 	meta_blocks += 1 + ppb + ppb * ppb;
776 	/* Does block tree limit file size? */
777 	if (res + meta_blocks <= upper_limit)
778 		goto check_lfs;
779 
780 	res = upper_limit;
781 	/* How many metadata blocks are needed for addressing upper_limit? */
782 	upper_limit -= EXT2_NDIR_BLOCKS;
783 	/* indirect blocks */
784 	meta_blocks = 1;
785 	upper_limit -= ppb;
786 	/* double indirect blocks */
787 	if (upper_limit < ppb * ppb) {
788 		meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
789 		res -= meta_blocks;
790 		goto check_lfs;
791 	}
792 	meta_blocks += 1 + ppb;
793 	upper_limit -= ppb * ppb;
794 	/* tripple indirect blocks for the rest */
795 	meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
796 		DIV_ROUND_UP(upper_limit, ppb*ppb);
797 	res -= meta_blocks;
798 check_lfs:
799 	res <<= bits;
800 	if (res > MAX_LFS_FILESIZE)
801 		res = MAX_LFS_FILESIZE;
802 
803 	return res;
804 }
805 
descriptor_loc(struct super_block * sb,unsigned long logic_sb_block,int nr)806 static unsigned long descriptor_loc(struct super_block *sb,
807 				    unsigned long logic_sb_block,
808 				    int nr)
809 {
810 	struct ext2_sb_info *sbi = EXT2_SB(sb);
811 	unsigned long bg, first_meta_bg;
812 	int has_super = 0;
813 
814 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
815 
816 	if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
817 	    nr < first_meta_bg)
818 		return (logic_sb_block + nr + 1);
819 	bg = sbi->s_desc_per_block * nr;
820 	if (ext2_bg_has_super(sb, bg))
821 		has_super = 1;
822 
823 	return ext2_group_first_block_no(sb, bg) + has_super;
824 }
825 
ext2_fill_super(struct super_block * sb,void * data,int silent)826 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
827 {
828 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
829 	struct buffer_head * bh;
830 	struct ext2_sb_info * sbi;
831 	struct ext2_super_block * es;
832 	struct inode *root;
833 	unsigned long block;
834 	unsigned long sb_block = get_sb_block(&data);
835 	unsigned long logic_sb_block;
836 	unsigned long offset = 0;
837 	unsigned long def_mount_opts;
838 	long ret = -ENOMEM;
839 	int blocksize = BLOCK_SIZE;
840 	int db_count;
841 	int i, j;
842 	__le32 features;
843 	int err;
844 	struct ext2_mount_options opts;
845 
846 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
847 	if (!sbi)
848 		goto failed;
849 
850 	sbi->s_blockgroup_lock =
851 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
852 	if (!sbi->s_blockgroup_lock) {
853 		kfree(sbi);
854 		goto failed;
855 	}
856 	sb->s_fs_info = sbi;
857 	sbi->s_sb_block = sb_block;
858 	sbi->s_daxdev = dax_dev;
859 
860 	spin_lock_init(&sbi->s_lock);
861 	ret = -EINVAL;
862 
863 	/*
864 	 * See what the current blocksize for the device is, and
865 	 * use that as the blocksize.  Otherwise (or if the blocksize
866 	 * is smaller than the default) use the default.
867 	 * This is important for devices that have a hardware
868 	 * sectorsize that is larger than the default.
869 	 */
870 	blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
871 	if (!blocksize) {
872 		ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
873 		goto failed_sbi;
874 	}
875 
876 	/*
877 	 * If the superblock doesn't start on a hardware sector boundary,
878 	 * calculate the offset.
879 	 */
880 	if (blocksize != BLOCK_SIZE) {
881 		logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
882 		offset = (sb_block*BLOCK_SIZE) % blocksize;
883 	} else {
884 		logic_sb_block = sb_block;
885 	}
886 
887 	if (!(bh = sb_bread(sb, logic_sb_block))) {
888 		ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
889 		goto failed_sbi;
890 	}
891 	/*
892 	 * Note: s_es must be initialized as soon as possible because
893 	 *       some ext2 macro-instructions depend on its value
894 	 */
895 	es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
896 	sbi->s_es = es;
897 	sb->s_magic = le16_to_cpu(es->s_magic);
898 
899 	if (sb->s_magic != EXT2_SUPER_MAGIC)
900 		goto cantfind_ext2;
901 
902 	opts.s_mount_opt = 0;
903 	/* Set defaults before we parse the mount options */
904 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
905 	if (def_mount_opts & EXT2_DEFM_DEBUG)
906 		set_opt(opts.s_mount_opt, DEBUG);
907 	if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
908 		set_opt(opts.s_mount_opt, GRPID);
909 	if (def_mount_opts & EXT2_DEFM_UID16)
910 		set_opt(opts.s_mount_opt, NO_UID32);
911 #ifdef CONFIG_EXT2_FS_XATTR
912 	if (def_mount_opts & EXT2_DEFM_XATTR_USER)
913 		set_opt(opts.s_mount_opt, XATTR_USER);
914 #endif
915 #ifdef CONFIG_EXT2_FS_POSIX_ACL
916 	if (def_mount_opts & EXT2_DEFM_ACL)
917 		set_opt(opts.s_mount_opt, POSIX_ACL);
918 #endif
919 
920 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
921 		set_opt(opts.s_mount_opt, ERRORS_PANIC);
922 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
923 		set_opt(opts.s_mount_opt, ERRORS_CONT);
924 	else
925 		set_opt(opts.s_mount_opt, ERRORS_RO);
926 
927 	opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
928 	opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
929 
930 	set_opt(opts.s_mount_opt, RESERVATION);
931 
932 	if (!parse_options((char *) data, sb, &opts))
933 		goto failed_mount;
934 
935 	sbi->s_mount_opt = opts.s_mount_opt;
936 	sbi->s_resuid = opts.s_resuid;
937 	sbi->s_resgid = opts.s_resgid;
938 
939 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
940 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
941 	sb->s_iflags |= SB_I_CGROUPWB;
942 
943 	if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
944 	    (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
945 	     EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
946 	     EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
947 		ext2_msg(sb, KERN_WARNING,
948 			"warning: feature flags set on rev 0 fs, "
949 			"running e2fsck is recommended");
950 	/*
951 	 * Check feature flags regardless of the revision level, since we
952 	 * previously didn't change the revision level when setting the flags,
953 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
954 	 */
955 	features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
956 	if (features) {
957 		ext2_msg(sb, KERN_ERR,	"error: couldn't mount because of "
958 		       "unsupported optional features (%x)",
959 			le32_to_cpu(features));
960 		goto failed_mount;
961 	}
962 	if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
963 		ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
964 		       "unsupported optional features (%x)",
965 		       le32_to_cpu(features));
966 		goto failed_mount;
967 	}
968 
969 	if (le32_to_cpu(es->s_log_block_size) >
970 	    (EXT2_MAX_BLOCK_LOG_SIZE - BLOCK_SIZE_BITS)) {
971 		ext2_msg(sb, KERN_ERR,
972 			 "Invalid log block size: %u",
973 			 le32_to_cpu(es->s_log_block_size));
974 		goto failed_mount;
975 	}
976 	blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
977 
978 	if (test_opt(sb, DAX)) {
979 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
980 			ext2_msg(sb, KERN_ERR,
981 				"DAX unsupported by block device. Turning off DAX.");
982 			clear_opt(sbi->s_mount_opt, DAX);
983 		}
984 	}
985 
986 	/* If the blocksize doesn't match, re-read the thing.. */
987 	if (sb->s_blocksize != blocksize) {
988 		brelse(bh);
989 
990 		if (!sb_set_blocksize(sb, blocksize)) {
991 			ext2_msg(sb, KERN_ERR,
992 				"error: bad blocksize %d", blocksize);
993 			goto failed_sbi;
994 		}
995 
996 		logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
997 		offset = (sb_block*BLOCK_SIZE) % blocksize;
998 		bh = sb_bread(sb, logic_sb_block);
999 		if(!bh) {
1000 			ext2_msg(sb, KERN_ERR, "error: couldn't read"
1001 				"superblock on 2nd try");
1002 			goto failed_sbi;
1003 		}
1004 		es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
1005 		sbi->s_es = es;
1006 		if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
1007 			ext2_msg(sb, KERN_ERR, "error: magic mismatch");
1008 			goto failed_mount;
1009 		}
1010 	}
1011 
1012 	sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
1013 	sb->s_max_links = EXT2_LINK_MAX;
1014 	sb->s_time_min = S32_MIN;
1015 	sb->s_time_max = S32_MAX;
1016 
1017 	if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
1018 		sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
1019 		sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
1020 	} else {
1021 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1022 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1023 		if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
1024 		    !is_power_of_2(sbi->s_inode_size) ||
1025 		    (sbi->s_inode_size > blocksize)) {
1026 			ext2_msg(sb, KERN_ERR,
1027 				"error: unsupported inode size: %d",
1028 				sbi->s_inode_size);
1029 			goto failed_mount;
1030 		}
1031 	}
1032 
1033 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1034 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1035 
1036 	sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1037 	if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1038 		goto cantfind_ext2;
1039 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
1040 					sbi->s_inodes_per_block;
1041 	sbi->s_desc_per_block = sb->s_blocksize /
1042 					sizeof (struct ext2_group_desc);
1043 	sbi->s_sbh = bh;
1044 	sbi->s_mount_state = le16_to_cpu(es->s_state);
1045 	sbi->s_addr_per_block_bits =
1046 		ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1047 	sbi->s_desc_per_block_bits =
1048 		ilog2 (EXT2_DESC_PER_BLOCK(sb));
1049 
1050 	if (sb->s_magic != EXT2_SUPER_MAGIC)
1051 		goto cantfind_ext2;
1052 
1053 	if (sb->s_blocksize != bh->b_size) {
1054 		if (!silent)
1055 			ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1056 		goto failed_mount;
1057 	}
1058 
1059 	if (es->s_log_frag_size != es->s_log_block_size) {
1060 		ext2_msg(sb, KERN_ERR,
1061 			"error: fragsize log %u != blocksize log %u",
1062 			le32_to_cpu(es->s_log_frag_size), sb->s_blocksize_bits);
1063 		goto failed_mount;
1064 	}
1065 
1066 	if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1067 		ext2_msg(sb, KERN_ERR,
1068 			"error: #blocks per group too big: %lu",
1069 			sbi->s_blocks_per_group);
1070 		goto failed_mount;
1071 	}
1072 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
1073 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1074 		ext2_msg(sb, KERN_ERR,
1075 			"error: invalid #inodes per group: %lu",
1076 			sbi->s_inodes_per_group);
1077 		goto failed_mount;
1078 	}
1079 
1080 	if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1081 		goto cantfind_ext2;
1082 	sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1083 				le32_to_cpu(es->s_first_data_block) - 1)
1084 					/ EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1085 	if ((u64)sbi->s_groups_count * sbi->s_inodes_per_group !=
1086 	    le32_to_cpu(es->s_inodes_count)) {
1087 		ext2_msg(sb, KERN_ERR, "error: invalid #inodes: %u vs computed %llu",
1088 			 le32_to_cpu(es->s_inodes_count),
1089 			 (u64)sbi->s_groups_count * sbi->s_inodes_per_group);
1090 		goto failed_mount;
1091 	}
1092 	db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1093 		   EXT2_DESC_PER_BLOCK(sb);
1094 	sbi->s_group_desc = kmalloc_array (db_count,
1095 					   sizeof(struct buffer_head *),
1096 					   GFP_KERNEL);
1097 	if (sbi->s_group_desc == NULL) {
1098 		ret = -ENOMEM;
1099 		ext2_msg(sb, KERN_ERR, "error: not enough memory");
1100 		goto failed_mount;
1101 	}
1102 	bgl_lock_init(sbi->s_blockgroup_lock);
1103 	sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1104 	if (!sbi->s_debts) {
1105 		ret = -ENOMEM;
1106 		ext2_msg(sb, KERN_ERR, "error: not enough memory");
1107 		goto failed_mount_group_desc;
1108 	}
1109 	for (i = 0; i < db_count; i++) {
1110 		block = descriptor_loc(sb, logic_sb_block, i);
1111 		sbi->s_group_desc[i] = sb_bread(sb, block);
1112 		if (!sbi->s_group_desc[i]) {
1113 			for (j = 0; j < i; j++)
1114 				brelse (sbi->s_group_desc[j]);
1115 			ext2_msg(sb, KERN_ERR,
1116 				"error: unable to read group descriptors");
1117 			goto failed_mount_group_desc;
1118 		}
1119 	}
1120 	if (!ext2_check_descriptors (sb)) {
1121 		ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1122 		goto failed_mount2;
1123 	}
1124 	sbi->s_gdb_count = db_count;
1125 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1126 	spin_lock_init(&sbi->s_next_gen_lock);
1127 
1128 	/* per fileystem reservation list head & lock */
1129 	spin_lock_init(&sbi->s_rsv_window_lock);
1130 	sbi->s_rsv_window_root = RB_ROOT;
1131 	/*
1132 	 * Add a single, static dummy reservation to the start of the
1133 	 * reservation window list --- it gives us a placeholder for
1134 	 * append-at-start-of-list which makes the allocation logic
1135 	 * _much_ simpler.
1136 	 */
1137 	sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1138 	sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1139 	sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1140 	sbi->s_rsv_window_head.rsv_goal_size = 0;
1141 	ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1142 
1143 	err = percpu_counter_init(&sbi->s_freeblocks_counter,
1144 				ext2_count_free_blocks(sb), GFP_KERNEL);
1145 	if (!err) {
1146 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
1147 				ext2_count_free_inodes(sb), GFP_KERNEL);
1148 	}
1149 	if (!err) {
1150 		err = percpu_counter_init(&sbi->s_dirs_counter,
1151 				ext2_count_dirs(sb), GFP_KERNEL);
1152 	}
1153 	if (err) {
1154 		ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1155 		goto failed_mount3;
1156 	}
1157 
1158 #ifdef CONFIG_EXT2_FS_XATTR
1159 	sbi->s_ea_block_cache = ext2_xattr_create_cache();
1160 	if (!sbi->s_ea_block_cache) {
1161 		ret = -ENOMEM;
1162 		ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1163 		goto failed_mount3;
1164 	}
1165 #endif
1166 	/*
1167 	 * set up enough so that it can read an inode
1168 	 */
1169 	sb->s_op = &ext2_sops;
1170 	sb->s_export_op = &ext2_export_ops;
1171 	sb->s_xattr = ext2_xattr_handlers;
1172 
1173 #ifdef CONFIG_QUOTA
1174 	sb->dq_op = &dquot_operations;
1175 	sb->s_qcop = &ext2_quotactl_ops;
1176 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1177 #endif
1178 
1179 	root = ext2_iget(sb, EXT2_ROOT_INO);
1180 	if (IS_ERR(root)) {
1181 		ret = PTR_ERR(root);
1182 		goto failed_mount3;
1183 	}
1184 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1185 		iput(root);
1186 		ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1187 		goto failed_mount3;
1188 	}
1189 
1190 	sb->s_root = d_make_root(root);
1191 	if (!sb->s_root) {
1192 		ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1193 		ret = -ENOMEM;
1194 		goto failed_mount3;
1195 	}
1196 	if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1197 		ext2_msg(sb, KERN_WARNING,
1198 			"warning: mounting ext3 filesystem as ext2");
1199 	if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1200 		sb->s_flags |= SB_RDONLY;
1201 	ext2_write_super(sb);
1202 	return 0;
1203 
1204 cantfind_ext2:
1205 	if (!silent)
1206 		ext2_msg(sb, KERN_ERR,
1207 			"error: can't find an ext2 filesystem on dev %s.",
1208 			sb->s_id);
1209 	goto failed_mount;
1210 failed_mount3:
1211 	ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1212 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
1213 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1214 	percpu_counter_destroy(&sbi->s_dirs_counter);
1215 failed_mount2:
1216 	for (i = 0; i < db_count; i++)
1217 		brelse(sbi->s_group_desc[i]);
1218 failed_mount_group_desc:
1219 	kfree(sbi->s_group_desc);
1220 	kfree(sbi->s_debts);
1221 failed_mount:
1222 	brelse(bh);
1223 failed_sbi:
1224 	sb->s_fs_info = NULL;
1225 	kfree(sbi->s_blockgroup_lock);
1226 	kfree(sbi);
1227 failed:
1228 	fs_put_dax(dax_dev);
1229 	return ret;
1230 }
1231 
ext2_clear_super_error(struct super_block * sb)1232 static void ext2_clear_super_error(struct super_block *sb)
1233 {
1234 	struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1235 
1236 	if (buffer_write_io_error(sbh)) {
1237 		/*
1238 		 * Oh, dear.  A previous attempt to write the
1239 		 * superblock failed.  This could happen because the
1240 		 * USB device was yanked out.  Or it could happen to
1241 		 * be a transient write error and maybe the block will
1242 		 * be remapped.  Nothing we can do but to retry the
1243 		 * write and hope for the best.
1244 		 */
1245 		ext2_msg(sb, KERN_ERR,
1246 		       "previous I/O error to superblock detected");
1247 		clear_buffer_write_io_error(sbh);
1248 		set_buffer_uptodate(sbh);
1249 	}
1250 }
1251 
ext2_sync_super(struct super_block * sb,struct ext2_super_block * es,int wait)1252 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1253 		     int wait)
1254 {
1255 	ext2_clear_super_error(sb);
1256 	spin_lock(&EXT2_SB(sb)->s_lock);
1257 	es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1258 	es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1259 	es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1260 	/* unlock before we do IO */
1261 	spin_unlock(&EXT2_SB(sb)->s_lock);
1262 	mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1263 	if (wait)
1264 		sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1265 }
1266 
1267 /*
1268  * In the second extended file system, it is not necessary to
1269  * write the super block since we use a mapping of the
1270  * disk super block in a buffer.
1271  *
1272  * However, this function is still used to set the fs valid
1273  * flags to 0.  We need to set this flag to 0 since the fs
1274  * may have been checked while mounted and e2fsck may have
1275  * set s_state to EXT2_VALID_FS after some corrections.
1276  */
ext2_sync_fs(struct super_block * sb,int wait)1277 static int ext2_sync_fs(struct super_block *sb, int wait)
1278 {
1279 	struct ext2_sb_info *sbi = EXT2_SB(sb);
1280 	struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1281 
1282 	/*
1283 	 * Write quota structures to quota file, sync_blockdev() will write
1284 	 * them to disk later
1285 	 */
1286 	dquot_writeback_dquots(sb, -1);
1287 
1288 	spin_lock(&sbi->s_lock);
1289 	if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1290 		ext2_debug("setting valid to 0\n");
1291 		es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1292 	}
1293 	spin_unlock(&sbi->s_lock);
1294 	ext2_sync_super(sb, es, wait);
1295 	return 0;
1296 }
1297 
ext2_freeze(struct super_block * sb)1298 static int ext2_freeze(struct super_block *sb)
1299 {
1300 	struct ext2_sb_info *sbi = EXT2_SB(sb);
1301 
1302 	/*
1303 	 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1304 	 * because we have unattached inodes and thus filesystem is not fully
1305 	 * consistent.
1306 	 */
1307 	if (atomic_long_read(&sb->s_remove_count)) {
1308 		ext2_sync_fs(sb, 1);
1309 		return 0;
1310 	}
1311 	/* Set EXT2_FS_VALID flag */
1312 	spin_lock(&sbi->s_lock);
1313 	sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1314 	spin_unlock(&sbi->s_lock);
1315 	ext2_sync_super(sb, sbi->s_es, 1);
1316 
1317 	return 0;
1318 }
1319 
ext2_unfreeze(struct super_block * sb)1320 static int ext2_unfreeze(struct super_block *sb)
1321 {
1322 	/* Just write sb to clear EXT2_VALID_FS flag */
1323 	ext2_write_super(sb);
1324 
1325 	return 0;
1326 }
1327 
ext2_write_super(struct super_block * sb)1328 static void ext2_write_super(struct super_block *sb)
1329 {
1330 	if (!sb_rdonly(sb))
1331 		ext2_sync_fs(sb, 1);
1332 }
1333 
ext2_remount(struct super_block * sb,int * flags,char * data)1334 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1335 {
1336 	struct ext2_sb_info * sbi = EXT2_SB(sb);
1337 	struct ext2_super_block * es;
1338 	struct ext2_mount_options new_opts;
1339 	int err;
1340 
1341 	sync_filesystem(sb);
1342 
1343 	spin_lock(&sbi->s_lock);
1344 	new_opts.s_mount_opt = sbi->s_mount_opt;
1345 	new_opts.s_resuid = sbi->s_resuid;
1346 	new_opts.s_resgid = sbi->s_resgid;
1347 	spin_unlock(&sbi->s_lock);
1348 
1349 	if (!parse_options(data, sb, &new_opts))
1350 		return -EINVAL;
1351 
1352 	spin_lock(&sbi->s_lock);
1353 	es = sbi->s_es;
1354 	if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1355 		ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1356 			 "dax flag with busy inodes while remounting");
1357 		new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1358 	}
1359 	if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1360 		goto out_set;
1361 	if (*flags & SB_RDONLY) {
1362 		if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1363 		    !(sbi->s_mount_state & EXT2_VALID_FS))
1364 			goto out_set;
1365 
1366 		/*
1367 		 * OK, we are remounting a valid rw partition rdonly, so set
1368 		 * the rdonly flag and then mark the partition as valid again.
1369 		 */
1370 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1371 		es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1372 		spin_unlock(&sbi->s_lock);
1373 
1374 		err = dquot_suspend(sb, -1);
1375 		if (err < 0)
1376 			return err;
1377 
1378 		ext2_sync_super(sb, es, 1);
1379 	} else {
1380 		__le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1381 					       ~EXT2_FEATURE_RO_COMPAT_SUPP);
1382 		if (ret) {
1383 			spin_unlock(&sbi->s_lock);
1384 			ext2_msg(sb, KERN_WARNING,
1385 				"warning: couldn't remount RDWR because of "
1386 				"unsupported optional features (%x).",
1387 				le32_to_cpu(ret));
1388 			return -EROFS;
1389 		}
1390 		/*
1391 		 * Mounting a RDONLY partition read-write, so reread and
1392 		 * store the current valid flag.  (It may have been changed
1393 		 * by e2fsck since we originally mounted the partition.)
1394 		 */
1395 		sbi->s_mount_state = le16_to_cpu(es->s_state);
1396 		if (!ext2_setup_super (sb, es, 0))
1397 			sb->s_flags &= ~SB_RDONLY;
1398 		spin_unlock(&sbi->s_lock);
1399 
1400 		ext2_write_super(sb);
1401 
1402 		dquot_resume(sb, -1);
1403 	}
1404 
1405 	spin_lock(&sbi->s_lock);
1406 out_set:
1407 	sbi->s_mount_opt = new_opts.s_mount_opt;
1408 	sbi->s_resuid = new_opts.s_resuid;
1409 	sbi->s_resgid = new_opts.s_resgid;
1410 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1411 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
1412 	spin_unlock(&sbi->s_lock);
1413 
1414 	return 0;
1415 }
1416 
ext2_statfs(struct dentry * dentry,struct kstatfs * buf)1417 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1418 {
1419 	struct super_block *sb = dentry->d_sb;
1420 	struct ext2_sb_info *sbi = EXT2_SB(sb);
1421 	struct ext2_super_block *es = sbi->s_es;
1422 	u64 fsid;
1423 
1424 	spin_lock(&sbi->s_lock);
1425 
1426 	if (test_opt (sb, MINIX_DF))
1427 		sbi->s_overhead_last = 0;
1428 	else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1429 		unsigned long i, overhead = 0;
1430 		smp_rmb();
1431 
1432 		/*
1433 		 * Compute the overhead (FS structures). This is constant
1434 		 * for a given filesystem unless the number of block groups
1435 		 * changes so we cache the previous value until it does.
1436 		 */
1437 
1438 		/*
1439 		 * All of the blocks before first_data_block are
1440 		 * overhead
1441 		 */
1442 		overhead = le32_to_cpu(es->s_first_data_block);
1443 
1444 		/*
1445 		 * Add the overhead attributed to the superblock and
1446 		 * block group descriptors.  If the sparse superblocks
1447 		 * feature is turned on, then not all groups have this.
1448 		 */
1449 		for (i = 0; i < sbi->s_groups_count; i++)
1450 			overhead += ext2_bg_has_super(sb, i) +
1451 				ext2_bg_num_gdb(sb, i);
1452 
1453 		/*
1454 		 * Every block group has an inode bitmap, a block
1455 		 * bitmap, and an inode table.
1456 		 */
1457 		overhead += (sbi->s_groups_count *
1458 			     (2 + sbi->s_itb_per_group));
1459 		sbi->s_overhead_last = overhead;
1460 		smp_wmb();
1461 		sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1462 	}
1463 
1464 	buf->f_type = EXT2_SUPER_MAGIC;
1465 	buf->f_bsize = sb->s_blocksize;
1466 	buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1467 	buf->f_bfree = ext2_count_free_blocks(sb);
1468 	es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1469 	buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1470 	if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1471 		buf->f_bavail = 0;
1472 	buf->f_files = le32_to_cpu(es->s_inodes_count);
1473 	buf->f_ffree = ext2_count_free_inodes(sb);
1474 	es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1475 	buf->f_namelen = EXT2_NAME_LEN;
1476 	fsid = le64_to_cpup((void *)es->s_uuid) ^
1477 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1478 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1479 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1480 	spin_unlock(&sbi->s_lock);
1481 	return 0;
1482 }
1483 
ext2_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)1484 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1485 	int flags, const char *dev_name, void *data)
1486 {
1487 	return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1488 }
1489 
1490 #ifdef CONFIG_QUOTA
1491 
1492 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1493  * acquiring the locks... As quota files are never truncated and quota code
1494  * itself serializes the operations (and no one else should touch the files)
1495  * 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)1496 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1497 			       size_t len, loff_t off)
1498 {
1499 	struct inode *inode = sb_dqopt(sb)->files[type];
1500 	sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1501 	int err = 0;
1502 	int offset = off & (sb->s_blocksize - 1);
1503 	int tocopy;
1504 	size_t toread;
1505 	struct buffer_head tmp_bh;
1506 	struct buffer_head *bh;
1507 	loff_t i_size = i_size_read(inode);
1508 
1509 	if (off > i_size)
1510 		return 0;
1511 	if (off+len > i_size)
1512 		len = i_size-off;
1513 	toread = len;
1514 	while (toread > 0) {
1515 		tocopy = sb->s_blocksize - offset < toread ?
1516 				sb->s_blocksize - offset : toread;
1517 
1518 		tmp_bh.b_state = 0;
1519 		tmp_bh.b_size = sb->s_blocksize;
1520 		err = ext2_get_block(inode, blk, &tmp_bh, 0);
1521 		if (err < 0)
1522 			return err;
1523 		if (!buffer_mapped(&tmp_bh))	/* A hole? */
1524 			memset(data, 0, tocopy);
1525 		else {
1526 			bh = sb_bread(sb, tmp_bh.b_blocknr);
1527 			if (!bh)
1528 				return -EIO;
1529 			memcpy(data, bh->b_data+offset, tocopy);
1530 			brelse(bh);
1531 		}
1532 		offset = 0;
1533 		toread -= tocopy;
1534 		data += tocopy;
1535 		blk++;
1536 	}
1537 	return len;
1538 }
1539 
1540 /* Write to quotafile */
ext2_quota_write(struct super_block * sb,int type,const char * data,size_t len,loff_t off)1541 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1542 				const char *data, size_t len, loff_t off)
1543 {
1544 	struct inode *inode = sb_dqopt(sb)->files[type];
1545 	sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1546 	int err = 0;
1547 	int offset = off & (sb->s_blocksize - 1);
1548 	int tocopy;
1549 	size_t towrite = len;
1550 	struct buffer_head tmp_bh;
1551 	struct buffer_head *bh;
1552 
1553 	while (towrite > 0) {
1554 		tocopy = sb->s_blocksize - offset < towrite ?
1555 				sb->s_blocksize - offset : towrite;
1556 
1557 		tmp_bh.b_state = 0;
1558 		tmp_bh.b_size = sb->s_blocksize;
1559 		err = ext2_get_block(inode, blk, &tmp_bh, 1);
1560 		if (err < 0)
1561 			goto out;
1562 		if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1563 			bh = sb_bread(sb, tmp_bh.b_blocknr);
1564 		else
1565 			bh = sb_getblk(sb, tmp_bh.b_blocknr);
1566 		if (unlikely(!bh)) {
1567 			err = -EIO;
1568 			goto out;
1569 		}
1570 		lock_buffer(bh);
1571 		memcpy(bh->b_data+offset, data, tocopy);
1572 		flush_dcache_page(bh->b_page);
1573 		set_buffer_uptodate(bh);
1574 		mark_buffer_dirty(bh);
1575 		unlock_buffer(bh);
1576 		brelse(bh);
1577 		offset = 0;
1578 		towrite -= tocopy;
1579 		data += tocopy;
1580 		blk++;
1581 	}
1582 out:
1583 	if (len == towrite)
1584 		return err;
1585 	if (inode->i_size < off+len-towrite)
1586 		i_size_write(inode, off+len-towrite);
1587 	inode_inc_iversion(inode);
1588 	inode->i_mtime = inode->i_ctime = current_time(inode);
1589 	mark_inode_dirty(inode);
1590 	return len - towrite;
1591 }
1592 
ext2_quota_on(struct super_block * sb,int type,int format_id,const struct path * path)1593 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1594 			 const struct path *path)
1595 {
1596 	int err;
1597 	struct inode *inode;
1598 
1599 	err = dquot_quota_on(sb, type, format_id, path);
1600 	if (err)
1601 		return err;
1602 
1603 	inode = d_inode(path->dentry);
1604 	inode_lock(inode);
1605 	EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1606 	inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1607 			S_NOATIME | S_IMMUTABLE);
1608 	inode_unlock(inode);
1609 	mark_inode_dirty(inode);
1610 
1611 	return 0;
1612 }
1613 
ext2_quota_off(struct super_block * sb,int type)1614 static int ext2_quota_off(struct super_block *sb, int type)
1615 {
1616 	struct inode *inode = sb_dqopt(sb)->files[type];
1617 	int err;
1618 
1619 	if (!inode || !igrab(inode))
1620 		goto out;
1621 
1622 	err = dquot_quota_off(sb, type);
1623 	if (err)
1624 		goto out_put;
1625 
1626 	inode_lock(inode);
1627 	EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1628 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1629 	inode_unlock(inode);
1630 	mark_inode_dirty(inode);
1631 out_put:
1632 	iput(inode);
1633 	return err;
1634 out:
1635 	return dquot_quota_off(sb, type);
1636 }
1637 
1638 #endif
1639 
1640 static struct file_system_type ext2_fs_type = {
1641 	.owner		= THIS_MODULE,
1642 	.name		= "ext2",
1643 	.mount		= ext2_mount,
1644 	.kill_sb	= kill_block_super,
1645 	.fs_flags	= FS_REQUIRES_DEV,
1646 };
1647 MODULE_ALIAS_FS("ext2");
1648 
init_ext2_fs(void)1649 static int __init init_ext2_fs(void)
1650 {
1651 	int err;
1652 
1653 	err = init_inodecache();
1654 	if (err)
1655 		return err;
1656         err = register_filesystem(&ext2_fs_type);
1657 	if (err)
1658 		goto out;
1659 	return 0;
1660 out:
1661 	destroy_inodecache();
1662 	return err;
1663 }
1664 
exit_ext2_fs(void)1665 static void __exit exit_ext2_fs(void)
1666 {
1667 	unregister_filesystem(&ext2_fs_type);
1668 	destroy_inodecache();
1669 }
1670 
1671 MODULE_AUTHOR("Remy Card and others");
1672 MODULE_DESCRIPTION("Second Extended Filesystem");
1673 MODULE_LICENSE("GPL");
1674 module_init(init_ext2_fs)
1675 module_exit(exit_ext2_fs)
1676