xref: /openbmc/linux/fs/ext2/super.c (revision 84fbfc33)
1 /*
2  *  linux/fs/ext2/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/slab.h>
23 #include <linux/init.h>
24 #include <linux/blkdev.h>
25 #include <linux/parser.h>
26 #include <linux/random.h>
27 #include <linux/buffer_head.h>
28 #include <linux/exportfs.h>
29 #include <linux/vfs.h>
30 #include <linux/seq_file.h>
31 #include <linux/mount.h>
32 #include <linux/log2.h>
33 #include <linux/quotaops.h>
34 #include <linux/uaccess.h>
35 #include <linux/dax.h>
36 #include "ext2.h"
37 #include "xattr.h"
38 #include "acl.h"
39 
40 static void ext2_write_super(struct super_block *sb);
41 static int ext2_remount (struct super_block * sb, int * flags, char * data);
42 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
43 static int ext2_sync_fs(struct super_block *sb, int wait);
44 static int ext2_freeze(struct super_block *sb);
45 static int ext2_unfreeze(struct super_block *sb);
46 
47 void ext2_error(struct super_block *sb, const char *function,
48 		const char *fmt, ...)
49 {
50 	struct va_format vaf;
51 	va_list args;
52 	struct ext2_sb_info *sbi = EXT2_SB(sb);
53 	struct ext2_super_block *es = sbi->s_es;
54 
55 	if (!sb_rdonly(sb)) {
56 		spin_lock(&sbi->s_lock);
57 		sbi->s_mount_state |= EXT2_ERROR_FS;
58 		es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
59 		spin_unlock(&sbi->s_lock);
60 		ext2_sync_super(sb, es, 1);
61 	}
62 
63 	va_start(args, fmt);
64 
65 	vaf.fmt = fmt;
66 	vaf.va = &args;
67 
68 	printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
69 	       sb->s_id, function, &vaf);
70 
71 	va_end(args);
72 
73 	if (test_opt(sb, ERRORS_PANIC))
74 		panic("EXT2-fs: panic from previous error\n");
75 	if (test_opt(sb, ERRORS_RO)) {
76 		ext2_msg(sb, KERN_CRIT,
77 			     "error: remounting filesystem read-only");
78 		sb->s_flags |= MS_RDONLY;
79 	}
80 }
81 
82 void ext2_msg(struct super_block *sb, const char *prefix,
83 		const char *fmt, ...)
84 {
85 	struct va_format vaf;
86 	va_list args;
87 
88 	va_start(args, fmt);
89 
90 	vaf.fmt = fmt;
91 	vaf.va = &args;
92 
93 	printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
94 
95 	va_end(args);
96 }
97 
98 /*
99  * This must be called with sbi->s_lock held.
100  */
101 void ext2_update_dynamic_rev(struct super_block *sb)
102 {
103 	struct ext2_super_block *es = EXT2_SB(sb)->s_es;
104 
105 	if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
106 		return;
107 
108 	ext2_msg(sb, KERN_WARNING,
109 		     "warning: updating to rev %d because of "
110 		     "new feature flag, running e2fsck is recommended",
111 		     EXT2_DYNAMIC_REV);
112 
113 	es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
114 	es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
115 	es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
116 	/* leave es->s_feature_*compat flags alone */
117 	/* es->s_uuid will be set by e2fsck if empty */
118 
119 	/*
120 	 * The rest of the superblock fields should be zero, and if not it
121 	 * means they are likely already in use, so leave them alone.  We
122 	 * can leave it up to e2fsck to clean up any inconsistencies there.
123 	 */
124 }
125 
126 #ifdef CONFIG_QUOTA
127 static int ext2_quota_off(struct super_block *sb, int type);
128 
129 static void ext2_quota_off_umount(struct super_block *sb)
130 {
131 	int type;
132 
133 	for (type = 0; type < MAXQUOTAS; type++)
134 		ext2_quota_off(sb, type);
135 }
136 #else
137 static inline void ext2_quota_off_umount(struct super_block *sb)
138 {
139 }
140 #endif
141 
142 static void ext2_put_super (struct super_block * sb)
143 {
144 	int db_count;
145 	int i;
146 	struct ext2_sb_info *sbi = EXT2_SB(sb);
147 
148 	ext2_quota_off_umount(sb);
149 
150 	if (sbi->s_ea_block_cache) {
151 		ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
152 		sbi->s_ea_block_cache = NULL;
153 	}
154 	if (!sb_rdonly(sb)) {
155 		struct ext2_super_block *es = sbi->s_es;
156 
157 		spin_lock(&sbi->s_lock);
158 		es->s_state = cpu_to_le16(sbi->s_mount_state);
159 		spin_unlock(&sbi->s_lock);
160 		ext2_sync_super(sb, es, 1);
161 	}
162 	db_count = sbi->s_gdb_count;
163 	for (i = 0; i < db_count; i++)
164 		if (sbi->s_group_desc[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 
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 	ei->vfs_inode.i_version = 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 
195 static void ext2_i_callback(struct rcu_head *head)
196 {
197 	struct inode *inode = container_of(head, struct inode, i_rcu);
198 	kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
199 }
200 
201 static void ext2_destroy_inode(struct inode *inode)
202 {
203 	call_rcu(&inode->i_rcu, ext2_i_callback);
204 }
205 
206 static void init_once(void *foo)
207 {
208 	struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
209 
210 	rwlock_init(&ei->i_meta_lock);
211 #ifdef CONFIG_EXT2_FS_XATTR
212 	init_rwsem(&ei->xattr_sem);
213 #endif
214 	mutex_init(&ei->truncate_mutex);
215 #ifdef CONFIG_FS_DAX
216 	init_rwsem(&ei->dax_sem);
217 #endif
218 	inode_init_once(&ei->vfs_inode);
219 }
220 
221 static int __init init_inodecache(void)
222 {
223 	ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
224 					     sizeof(struct ext2_inode_info),
225 					     0, (SLAB_RECLAIM_ACCOUNT|
226 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
227 					     init_once);
228 	if (ext2_inode_cachep == NULL)
229 		return -ENOMEM;
230 	return 0;
231 }
232 
233 static void destroy_inodecache(void)
234 {
235 	/*
236 	 * Make sure all delayed rcu free inodes are flushed before we
237 	 * destroy cache.
238 	 */
239 	rcu_barrier();
240 	kmem_cache_destroy(ext2_inode_cachep);
241 }
242 
243 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
244 {
245 	struct super_block *sb = root->d_sb;
246 	struct ext2_sb_info *sbi = EXT2_SB(sb);
247 	struct ext2_super_block *es = sbi->s_es;
248 	unsigned long def_mount_opts;
249 
250 	spin_lock(&sbi->s_lock);
251 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
252 
253 	if (sbi->s_sb_block != 1)
254 		seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
255 	if (test_opt(sb, MINIX_DF))
256 		seq_puts(seq, ",minixdf");
257 	if (test_opt(sb, GRPID))
258 		seq_puts(seq, ",grpid");
259 	if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
260 		seq_puts(seq, ",nogrpid");
261 	if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
262 	    le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
263 		seq_printf(seq, ",resuid=%u",
264 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
265 	}
266 	if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
267 	    le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
268 		seq_printf(seq, ",resgid=%u",
269 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
270 	}
271 	if (test_opt(sb, ERRORS_RO)) {
272 		int def_errors = le16_to_cpu(es->s_errors);
273 
274 		if (def_errors == EXT2_ERRORS_PANIC ||
275 		    def_errors == EXT2_ERRORS_CONTINUE) {
276 			seq_puts(seq, ",errors=remount-ro");
277 		}
278 	}
279 	if (test_opt(sb, ERRORS_CONT))
280 		seq_puts(seq, ",errors=continue");
281 	if (test_opt(sb, ERRORS_PANIC))
282 		seq_puts(seq, ",errors=panic");
283 	if (test_opt(sb, NO_UID32))
284 		seq_puts(seq, ",nouid32");
285 	if (test_opt(sb, DEBUG))
286 		seq_puts(seq, ",debug");
287 	if (test_opt(sb, OLDALLOC))
288 		seq_puts(seq, ",oldalloc");
289 
290 #ifdef CONFIG_EXT2_FS_XATTR
291 	if (test_opt(sb, XATTR_USER))
292 		seq_puts(seq, ",user_xattr");
293 	if (!test_opt(sb, XATTR_USER) &&
294 	    (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
295 		seq_puts(seq, ",nouser_xattr");
296 	}
297 #endif
298 
299 #ifdef CONFIG_EXT2_FS_POSIX_ACL
300 	if (test_opt(sb, POSIX_ACL))
301 		seq_puts(seq, ",acl");
302 	if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
303 		seq_puts(seq, ",noacl");
304 #endif
305 
306 	if (test_opt(sb, NOBH))
307 		seq_puts(seq, ",nobh");
308 
309 #if defined(CONFIG_QUOTA)
310 	if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
311 		seq_puts(seq, ",usrquota");
312 
313 	if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
314 		seq_puts(seq, ",grpquota");
315 #endif
316 
317 #ifdef CONFIG_FS_DAX
318 	if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
319 		seq_puts(seq, ",xip");
320 	if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
321 		seq_puts(seq, ",dax");
322 #endif
323 
324 	if (!test_opt(sb, RESERVATION))
325 		seq_puts(seq, ",noreservation");
326 
327 	spin_unlock(&sbi->s_lock);
328 	return 0;
329 }
330 
331 #ifdef CONFIG_QUOTA
332 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
333 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
334 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
335 			 const struct path *path);
336 static struct dquot **ext2_get_dquots(struct inode *inode)
337 {
338 	return EXT2_I(inode)->i_dquot;
339 }
340 
341 static const struct quotactl_ops ext2_quotactl_ops = {
342 	.quota_on	= ext2_quota_on,
343 	.quota_off	= ext2_quota_off,
344 	.quota_sync	= dquot_quota_sync,
345 	.get_state	= dquot_get_state,
346 	.set_info	= dquot_set_dqinfo,
347 	.get_dqblk	= dquot_get_dqblk,
348 	.set_dqblk	= dquot_set_dqblk,
349 	.get_nextdqblk	= dquot_get_next_dqblk,
350 };
351 #endif
352 
353 static const struct super_operations ext2_sops = {
354 	.alloc_inode	= ext2_alloc_inode,
355 	.destroy_inode	= ext2_destroy_inode,
356 	.write_inode	= ext2_write_inode,
357 	.evict_inode	= ext2_evict_inode,
358 	.put_super	= ext2_put_super,
359 	.sync_fs	= ext2_sync_fs,
360 	.freeze_fs	= ext2_freeze,
361 	.unfreeze_fs	= ext2_unfreeze,
362 	.statfs		= ext2_statfs,
363 	.remount_fs	= ext2_remount,
364 	.show_options	= ext2_show_options,
365 #ifdef CONFIG_QUOTA
366 	.quota_read	= ext2_quota_read,
367 	.quota_write	= ext2_quota_write,
368 	.get_dquots	= ext2_get_dquots,
369 #endif
370 };
371 
372 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
373 		u64 ino, u32 generation)
374 {
375 	struct inode *inode;
376 
377 	if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
378 		return ERR_PTR(-ESTALE);
379 	if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
380 		return ERR_PTR(-ESTALE);
381 
382 	/*
383 	 * ext2_iget isn't quite right if the inode is currently unallocated!
384 	 * However ext2_iget currently does appropriate checks to handle stale
385 	 * inodes so everything is OK.
386 	 */
387 	inode = ext2_iget(sb, ino);
388 	if (IS_ERR(inode))
389 		return ERR_CAST(inode);
390 	if (generation && inode->i_generation != generation) {
391 		/* we didn't find the right inode.. */
392 		iput(inode);
393 		return ERR_PTR(-ESTALE);
394 	}
395 	return inode;
396 }
397 
398 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
399 		int fh_len, int fh_type)
400 {
401 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
402 				    ext2_nfs_get_inode);
403 }
404 
405 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
406 		int fh_len, int fh_type)
407 {
408 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
409 				    ext2_nfs_get_inode);
410 }
411 
412 static const struct export_operations ext2_export_ops = {
413 	.fh_to_dentry = ext2_fh_to_dentry,
414 	.fh_to_parent = ext2_fh_to_parent,
415 	.get_parent = ext2_get_parent,
416 };
417 
418 static unsigned long get_sb_block(void **data)
419 {
420 	unsigned long 	sb_block;
421 	char 		*options = (char *) *data;
422 
423 	if (!options || strncmp(options, "sb=", 3) != 0)
424 		return 1;	/* Default location */
425 	options += 3;
426 	sb_block = simple_strtoul(options, &options, 0);
427 	if (*options && *options != ',') {
428 		printk("EXT2-fs: Invalid sb specification: %s\n",
429 		       (char *) *data);
430 		return 1;
431 	}
432 	if (*options == ',')
433 		options++;
434 	*data = (void *) options;
435 	return sb_block;
436 }
437 
438 enum {
439 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
440 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
441 	Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
442 	Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
443 	Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
444 	Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
445 };
446 
447 static const match_table_t tokens = {
448 	{Opt_bsd_df, "bsddf"},
449 	{Opt_minix_df, "minixdf"},
450 	{Opt_grpid, "grpid"},
451 	{Opt_grpid, "bsdgroups"},
452 	{Opt_nogrpid, "nogrpid"},
453 	{Opt_nogrpid, "sysvgroups"},
454 	{Opt_resgid, "resgid=%u"},
455 	{Opt_resuid, "resuid=%u"},
456 	{Opt_sb, "sb=%u"},
457 	{Opt_err_cont, "errors=continue"},
458 	{Opt_err_panic, "errors=panic"},
459 	{Opt_err_ro, "errors=remount-ro"},
460 	{Opt_nouid32, "nouid32"},
461 	{Opt_nocheck, "check=none"},
462 	{Opt_nocheck, "nocheck"},
463 	{Opt_debug, "debug"},
464 	{Opt_oldalloc, "oldalloc"},
465 	{Opt_orlov, "orlov"},
466 	{Opt_nobh, "nobh"},
467 	{Opt_user_xattr, "user_xattr"},
468 	{Opt_nouser_xattr, "nouser_xattr"},
469 	{Opt_acl, "acl"},
470 	{Opt_noacl, "noacl"},
471 	{Opt_xip, "xip"},
472 	{Opt_dax, "dax"},
473 	{Opt_grpquota, "grpquota"},
474 	{Opt_ignore, "noquota"},
475 	{Opt_quota, "quota"},
476 	{Opt_usrquota, "usrquota"},
477 	{Opt_reservation, "reservation"},
478 	{Opt_noreservation, "noreservation"},
479 	{Opt_err, NULL}
480 };
481 
482 static int parse_options(char *options, struct super_block *sb)
483 {
484 	char *p;
485 	struct ext2_sb_info *sbi = EXT2_SB(sb);
486 	substring_t args[MAX_OPT_ARGS];
487 	int option;
488 	kuid_t uid;
489 	kgid_t gid;
490 
491 	if (!options)
492 		return 1;
493 
494 	while ((p = strsep (&options, ",")) != NULL) {
495 		int token;
496 		if (!*p)
497 			continue;
498 
499 		token = match_token(p, tokens, args);
500 		switch (token) {
501 		case Opt_bsd_df:
502 			clear_opt (sbi->s_mount_opt, MINIX_DF);
503 			break;
504 		case Opt_minix_df:
505 			set_opt (sbi->s_mount_opt, MINIX_DF);
506 			break;
507 		case Opt_grpid:
508 			set_opt (sbi->s_mount_opt, GRPID);
509 			break;
510 		case Opt_nogrpid:
511 			clear_opt (sbi->s_mount_opt, GRPID);
512 			break;
513 		case Opt_resuid:
514 			if (match_int(&args[0], &option))
515 				return 0;
516 			uid = make_kuid(current_user_ns(), option);
517 			if (!uid_valid(uid)) {
518 				ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
519 				return 0;
520 
521 			}
522 			sbi->s_resuid = uid;
523 			break;
524 		case Opt_resgid:
525 			if (match_int(&args[0], &option))
526 				return 0;
527 			gid = make_kgid(current_user_ns(), option);
528 			if (!gid_valid(gid)) {
529 				ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
530 				return 0;
531 			}
532 			sbi->s_resgid = gid;
533 			break;
534 		case Opt_sb:
535 			/* handled by get_sb_block() instead of here */
536 			/* *sb_block = match_int(&args[0]); */
537 			break;
538 		case Opt_err_panic:
539 			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
540 			clear_opt (sbi->s_mount_opt, ERRORS_RO);
541 			set_opt (sbi->s_mount_opt, ERRORS_PANIC);
542 			break;
543 		case Opt_err_ro:
544 			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
545 			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
546 			set_opt (sbi->s_mount_opt, ERRORS_RO);
547 			break;
548 		case Opt_err_cont:
549 			clear_opt (sbi->s_mount_opt, ERRORS_RO);
550 			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
551 			set_opt (sbi->s_mount_opt, ERRORS_CONT);
552 			break;
553 		case Opt_nouid32:
554 			set_opt (sbi->s_mount_opt, NO_UID32);
555 			break;
556 		case Opt_nocheck:
557 			clear_opt (sbi->s_mount_opt, CHECK);
558 			break;
559 		case Opt_debug:
560 			set_opt (sbi->s_mount_opt, DEBUG);
561 			break;
562 		case Opt_oldalloc:
563 			set_opt (sbi->s_mount_opt, OLDALLOC);
564 			break;
565 		case Opt_orlov:
566 			clear_opt (sbi->s_mount_opt, OLDALLOC);
567 			break;
568 		case Opt_nobh:
569 			set_opt (sbi->s_mount_opt, NOBH);
570 			break;
571 #ifdef CONFIG_EXT2_FS_XATTR
572 		case Opt_user_xattr:
573 			set_opt (sbi->s_mount_opt, XATTR_USER);
574 			break;
575 		case Opt_nouser_xattr:
576 			clear_opt (sbi->s_mount_opt, XATTR_USER);
577 			break;
578 #else
579 		case Opt_user_xattr:
580 		case Opt_nouser_xattr:
581 			ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
582 				"not supported");
583 			break;
584 #endif
585 #ifdef CONFIG_EXT2_FS_POSIX_ACL
586 		case Opt_acl:
587 			set_opt(sbi->s_mount_opt, POSIX_ACL);
588 			break;
589 		case Opt_noacl:
590 			clear_opt(sbi->s_mount_opt, POSIX_ACL);
591 			break;
592 #else
593 		case Opt_acl:
594 		case Opt_noacl:
595 			ext2_msg(sb, KERN_INFO,
596 				"(no)acl options not supported");
597 			break;
598 #endif
599 		case Opt_xip:
600 			ext2_msg(sb, KERN_INFO, "use dax instead of xip");
601 			set_opt(sbi->s_mount_opt, XIP);
602 			/* Fall through */
603 		case Opt_dax:
604 #ifdef CONFIG_FS_DAX
605 			ext2_msg(sb, KERN_WARNING,
606 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
607 			set_opt(sbi->s_mount_opt, DAX);
608 #else
609 			ext2_msg(sb, 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 			set_opt(sbi->s_mount_opt, USRQUOTA);
617 			break;
618 
619 		case Opt_grpquota:
620 			set_opt(sbi->s_mount_opt, GRPQUOTA);
621 			break;
622 #else
623 		case Opt_quota:
624 		case Opt_usrquota:
625 		case Opt_grpquota:
626 			ext2_msg(sb, KERN_INFO,
627 				"quota operations not supported");
628 			break;
629 #endif
630 
631 		case Opt_reservation:
632 			set_opt(sbi->s_mount_opt, RESERVATION);
633 			ext2_msg(sb, KERN_INFO, "reservations ON");
634 			break;
635 		case Opt_noreservation:
636 			clear_opt(sbi->s_mount_opt, RESERVATION);
637 			ext2_msg(sb, KERN_INFO, "reservations OFF");
638 			break;
639 		case Opt_ignore:
640 			break;
641 		default:
642 			return 0;
643 		}
644 	}
645 	return 1;
646 }
647 
648 static int ext2_setup_super (struct super_block * sb,
649 			      struct ext2_super_block * es,
650 			      int read_only)
651 {
652 	int res = 0;
653 	struct ext2_sb_info *sbi = EXT2_SB(sb);
654 
655 	if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
656 		ext2_msg(sb, KERN_ERR,
657 			"error: revision level too high, "
658 			"forcing read-only mode");
659 		res = MS_RDONLY;
660 	}
661 	if (read_only)
662 		return res;
663 	if (!(sbi->s_mount_state & EXT2_VALID_FS))
664 		ext2_msg(sb, KERN_WARNING,
665 			"warning: mounting unchecked fs, "
666 			"running e2fsck is recommended");
667 	else if ((sbi->s_mount_state & EXT2_ERROR_FS))
668 		ext2_msg(sb, KERN_WARNING,
669 			"warning: mounting fs with errors, "
670 			"running e2fsck is recommended");
671 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
672 		 le16_to_cpu(es->s_mnt_count) >=
673 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
674 		ext2_msg(sb, KERN_WARNING,
675 			"warning: maximal mount count reached, "
676 			"running e2fsck is recommended");
677 	else if (le32_to_cpu(es->s_checkinterval) &&
678 		(le32_to_cpu(es->s_lastcheck) +
679 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
680 		ext2_msg(sb, KERN_WARNING,
681 			"warning: checktime reached, "
682 			"running e2fsck is recommended");
683 	if (!le16_to_cpu(es->s_max_mnt_count))
684 		es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
685 	le16_add_cpu(&es->s_mnt_count, 1);
686 	if (test_opt (sb, DEBUG))
687 		ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
688 			"bpg=%lu, ipg=%lu, mo=%04lx]",
689 			EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
690 			sbi->s_frag_size,
691 			sbi->s_groups_count,
692 			EXT2_BLOCKS_PER_GROUP(sb),
693 			EXT2_INODES_PER_GROUP(sb),
694 			sbi->s_mount_opt);
695 	return res;
696 }
697 
698 static int ext2_check_descriptors(struct super_block *sb)
699 {
700 	int i;
701 	struct ext2_sb_info *sbi = EXT2_SB(sb);
702 
703 	ext2_debug ("Checking group descriptors");
704 
705 	for (i = 0; i < sbi->s_groups_count; i++) {
706 		struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
707 		ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
708 		ext2_fsblk_t last_block;
709 
710 		if (i == sbi->s_groups_count - 1)
711 			last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
712 		else
713 			last_block = first_block +
714 				(EXT2_BLOCKS_PER_GROUP(sb) - 1);
715 
716 		if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
717 		    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
718 		{
719 			ext2_error (sb, "ext2_check_descriptors",
720 				    "Block bitmap for group %d"
721 				    " not in group (block %lu)!",
722 				    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
723 			return 0;
724 		}
725 		if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
726 		    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
727 		{
728 			ext2_error (sb, "ext2_check_descriptors",
729 				    "Inode bitmap for group %d"
730 				    " not in group (block %lu)!",
731 				    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
732 			return 0;
733 		}
734 		if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
735 		    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
736 		    last_block)
737 		{
738 			ext2_error (sb, "ext2_check_descriptors",
739 				    "Inode table for group %d"
740 				    " not in group (block %lu)!",
741 				    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
742 			return 0;
743 		}
744 	}
745 	return 1;
746 }
747 
748 /*
749  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
750  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
751  * We need to be 1 filesystem block less than the 2^32 sector limit.
752  */
753 static loff_t ext2_max_size(int bits)
754 {
755 	loff_t res = EXT2_NDIR_BLOCKS;
756 	int meta_blocks;
757 	loff_t upper_limit;
758 
759 	/* This is calculated to be the largest file size for a
760 	 * dense, file such that the total number of
761 	 * sectors in the file, including data and all indirect blocks,
762 	 * does not exceed 2^32 -1
763 	 * __u32 i_blocks representing the total number of
764 	 * 512 bytes blocks of the file
765 	 */
766 	upper_limit = (1LL << 32) - 1;
767 
768 	/* total blocks in file system block size */
769 	upper_limit >>= (bits - 9);
770 
771 
772 	/* indirect blocks */
773 	meta_blocks = 1;
774 	/* double indirect blocks */
775 	meta_blocks += 1 + (1LL << (bits-2));
776 	/* tripple indirect blocks */
777 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
778 
779 	upper_limit -= meta_blocks;
780 	upper_limit <<= bits;
781 
782 	res += 1LL << (bits-2);
783 	res += 1LL << (2*(bits-2));
784 	res += 1LL << (3*(bits-2));
785 	res <<= bits;
786 	if (res > upper_limit)
787 		res = upper_limit;
788 
789 	if (res > MAX_LFS_FILESIZE)
790 		res = MAX_LFS_FILESIZE;
791 
792 	return res;
793 }
794 
795 static unsigned long descriptor_loc(struct super_block *sb,
796 				    unsigned long logic_sb_block,
797 				    int nr)
798 {
799 	struct ext2_sb_info *sbi = EXT2_SB(sb);
800 	unsigned long bg, first_meta_bg;
801 	int has_super = 0;
802 
803 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
804 
805 	if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
806 	    nr < first_meta_bg)
807 		return (logic_sb_block + nr + 1);
808 	bg = sbi->s_desc_per_block * nr;
809 	if (ext2_bg_has_super(sb, bg))
810 		has_super = 1;
811 
812 	return ext2_group_first_block_no(sb, bg) + has_super;
813 }
814 
815 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
816 {
817 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
818 	struct buffer_head * bh;
819 	struct ext2_sb_info * sbi;
820 	struct ext2_super_block * es;
821 	struct inode *root;
822 	unsigned long block;
823 	unsigned long sb_block = get_sb_block(&data);
824 	unsigned long logic_sb_block;
825 	unsigned long offset = 0;
826 	unsigned long def_mount_opts;
827 	long ret = -EINVAL;
828 	int blocksize = BLOCK_SIZE;
829 	int db_count;
830 	int i, j;
831 	__le32 features;
832 	int err;
833 
834 	err = -ENOMEM;
835 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
836 	if (!sbi)
837 		goto failed;
838 
839 	sbi->s_blockgroup_lock =
840 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
841 	if (!sbi->s_blockgroup_lock) {
842 		kfree(sbi);
843 		goto failed;
844 	}
845 	sb->s_fs_info = sbi;
846 	sbi->s_sb_block = sb_block;
847 	sbi->s_daxdev = dax_dev;
848 
849 	spin_lock_init(&sbi->s_lock);
850 
851 	/*
852 	 * See what the current blocksize for the device is, and
853 	 * use that as the blocksize.  Otherwise (or if the blocksize
854 	 * is smaller than the default) use the default.
855 	 * This is important for devices that have a hardware
856 	 * sectorsize that is larger than the default.
857 	 */
858 	blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
859 	if (!blocksize) {
860 		ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
861 		goto failed_sbi;
862 	}
863 
864 	/*
865 	 * If the superblock doesn't start on a hardware sector boundary,
866 	 * calculate the offset.
867 	 */
868 	if (blocksize != BLOCK_SIZE) {
869 		logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
870 		offset = (sb_block*BLOCK_SIZE) % blocksize;
871 	} else {
872 		logic_sb_block = sb_block;
873 	}
874 
875 	if (!(bh = sb_bread(sb, logic_sb_block))) {
876 		ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
877 		goto failed_sbi;
878 	}
879 	/*
880 	 * Note: s_es must be initialized as soon as possible because
881 	 *       some ext2 macro-instructions depend on its value
882 	 */
883 	es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
884 	sbi->s_es = es;
885 	sb->s_magic = le16_to_cpu(es->s_magic);
886 
887 	if (sb->s_magic != EXT2_SUPER_MAGIC)
888 		goto cantfind_ext2;
889 
890 	/* Set defaults before we parse the mount options */
891 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
892 	if (def_mount_opts & EXT2_DEFM_DEBUG)
893 		set_opt(sbi->s_mount_opt, DEBUG);
894 	if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
895 		set_opt(sbi->s_mount_opt, GRPID);
896 	if (def_mount_opts & EXT2_DEFM_UID16)
897 		set_opt(sbi->s_mount_opt, NO_UID32);
898 #ifdef CONFIG_EXT2_FS_XATTR
899 	if (def_mount_opts & EXT2_DEFM_XATTR_USER)
900 		set_opt(sbi->s_mount_opt, XATTR_USER);
901 #endif
902 #ifdef CONFIG_EXT2_FS_POSIX_ACL
903 	if (def_mount_opts & EXT2_DEFM_ACL)
904 		set_opt(sbi->s_mount_opt, POSIX_ACL);
905 #endif
906 
907 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
908 		set_opt(sbi->s_mount_opt, ERRORS_PANIC);
909 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
910 		set_opt(sbi->s_mount_opt, ERRORS_CONT);
911 	else
912 		set_opt(sbi->s_mount_opt, ERRORS_RO);
913 
914 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
915 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
916 
917 	set_opt(sbi->s_mount_opt, RESERVATION);
918 
919 	if (!parse_options((char *) data, sb))
920 		goto failed_mount;
921 
922 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
923 		((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
924 		 MS_POSIXACL : 0);
925 	sb->s_iflags |= SB_I_CGROUPWB;
926 
927 	if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
928 	    (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
929 	     EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
930 	     EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
931 		ext2_msg(sb, KERN_WARNING,
932 			"warning: feature flags set on rev 0 fs, "
933 			"running e2fsck is recommended");
934 	/*
935 	 * Check feature flags regardless of the revision level, since we
936 	 * previously didn't change the revision level when setting the flags,
937 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
938 	 */
939 	features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
940 	if (features) {
941 		ext2_msg(sb, KERN_ERR,	"error: couldn't mount because of "
942 		       "unsupported optional features (%x)",
943 			le32_to_cpu(features));
944 		goto failed_mount;
945 	}
946 	if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
947 		ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
948 		       "unsupported optional features (%x)",
949 		       le32_to_cpu(features));
950 		goto failed_mount;
951 	}
952 
953 	blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
954 
955 	if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
956 		err = bdev_dax_supported(sb, blocksize);
957 		if (err)
958 			goto failed_mount;
959 	}
960 
961 	/* If the blocksize doesn't match, re-read the thing.. */
962 	if (sb->s_blocksize != blocksize) {
963 		brelse(bh);
964 
965 		if (!sb_set_blocksize(sb, blocksize)) {
966 			ext2_msg(sb, KERN_ERR,
967 				"error: bad blocksize %d", blocksize);
968 			goto failed_sbi;
969 		}
970 
971 		logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
972 		offset = (sb_block*BLOCK_SIZE) % blocksize;
973 		bh = sb_bread(sb, logic_sb_block);
974 		if(!bh) {
975 			ext2_msg(sb, KERN_ERR, "error: couldn't read"
976 				"superblock on 2nd try");
977 			goto failed_sbi;
978 		}
979 		es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
980 		sbi->s_es = es;
981 		if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
982 			ext2_msg(sb, KERN_ERR, "error: magic mismatch");
983 			goto failed_mount;
984 		}
985 	}
986 
987 	sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
988 	sb->s_max_links = EXT2_LINK_MAX;
989 
990 	if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
991 		sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
992 		sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
993 	} else {
994 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
995 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
996 		if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
997 		    !is_power_of_2(sbi->s_inode_size) ||
998 		    (sbi->s_inode_size > blocksize)) {
999 			ext2_msg(sb, KERN_ERR,
1000 				"error: unsupported inode size: %d",
1001 				sbi->s_inode_size);
1002 			goto failed_mount;
1003 		}
1004 	}
1005 
1006 	sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1007 				   le32_to_cpu(es->s_log_frag_size);
1008 	if (sbi->s_frag_size == 0)
1009 		goto cantfind_ext2;
1010 	sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1011 
1012 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1013 	sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1014 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1015 
1016 	if (EXT2_INODE_SIZE(sb) == 0)
1017 		goto cantfind_ext2;
1018 	sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1019 	if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1020 		goto cantfind_ext2;
1021 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
1022 					sbi->s_inodes_per_block;
1023 	sbi->s_desc_per_block = sb->s_blocksize /
1024 					sizeof (struct ext2_group_desc);
1025 	sbi->s_sbh = bh;
1026 	sbi->s_mount_state = le16_to_cpu(es->s_state);
1027 	sbi->s_addr_per_block_bits =
1028 		ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1029 	sbi->s_desc_per_block_bits =
1030 		ilog2 (EXT2_DESC_PER_BLOCK(sb));
1031 
1032 	if (sb->s_magic != EXT2_SUPER_MAGIC)
1033 		goto cantfind_ext2;
1034 
1035 	if (sb->s_blocksize != bh->b_size) {
1036 		if (!silent)
1037 			ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1038 		goto failed_mount;
1039 	}
1040 
1041 	if (sb->s_blocksize != sbi->s_frag_size) {
1042 		ext2_msg(sb, KERN_ERR,
1043 			"error: fragsize %lu != blocksize %lu"
1044 			"(not supported yet)",
1045 			sbi->s_frag_size, sb->s_blocksize);
1046 		goto failed_mount;
1047 	}
1048 
1049 	if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1050 		ext2_msg(sb, KERN_ERR,
1051 			"error: #blocks per group too big: %lu",
1052 			sbi->s_blocks_per_group);
1053 		goto failed_mount;
1054 	}
1055 	if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1056 		ext2_msg(sb, KERN_ERR,
1057 			"error: #fragments per group too big: %lu",
1058 			sbi->s_frags_per_group);
1059 		goto failed_mount;
1060 	}
1061 	if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1062 		ext2_msg(sb, KERN_ERR,
1063 			"error: #inodes per group too big: %lu",
1064 			sbi->s_inodes_per_group);
1065 		goto failed_mount;
1066 	}
1067 
1068 	if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1069 		goto cantfind_ext2;
1070  	sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1071  				le32_to_cpu(es->s_first_data_block) - 1)
1072  					/ EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1073 	db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1074 		   EXT2_DESC_PER_BLOCK(sb);
1075 	sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1076 	if (sbi->s_group_desc == NULL) {
1077 		ext2_msg(sb, KERN_ERR, "error: not enough memory");
1078 		goto failed_mount;
1079 	}
1080 	bgl_lock_init(sbi->s_blockgroup_lock);
1081 	sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1082 	if (!sbi->s_debts) {
1083 		ext2_msg(sb, KERN_ERR, "error: not enough memory");
1084 		goto failed_mount_group_desc;
1085 	}
1086 	for (i = 0; i < db_count; i++) {
1087 		block = descriptor_loc(sb, logic_sb_block, i);
1088 		sbi->s_group_desc[i] = sb_bread(sb, block);
1089 		if (!sbi->s_group_desc[i]) {
1090 			for (j = 0; j < i; j++)
1091 				brelse (sbi->s_group_desc[j]);
1092 			ext2_msg(sb, KERN_ERR,
1093 				"error: unable to read group descriptors");
1094 			goto failed_mount_group_desc;
1095 		}
1096 	}
1097 	if (!ext2_check_descriptors (sb)) {
1098 		ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1099 		goto failed_mount2;
1100 	}
1101 	sbi->s_gdb_count = db_count;
1102 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1103 	spin_lock_init(&sbi->s_next_gen_lock);
1104 
1105 	/* per fileystem reservation list head & lock */
1106 	spin_lock_init(&sbi->s_rsv_window_lock);
1107 	sbi->s_rsv_window_root = RB_ROOT;
1108 	/*
1109 	 * Add a single, static dummy reservation to the start of the
1110 	 * reservation window list --- it gives us a placeholder for
1111 	 * append-at-start-of-list which makes the allocation logic
1112 	 * _much_ simpler.
1113 	 */
1114 	sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1115 	sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1116 	sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1117 	sbi->s_rsv_window_head.rsv_goal_size = 0;
1118 	ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1119 
1120 	err = percpu_counter_init(&sbi->s_freeblocks_counter,
1121 				ext2_count_free_blocks(sb), GFP_KERNEL);
1122 	if (!err) {
1123 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
1124 				ext2_count_free_inodes(sb), GFP_KERNEL);
1125 	}
1126 	if (!err) {
1127 		err = percpu_counter_init(&sbi->s_dirs_counter,
1128 				ext2_count_dirs(sb), GFP_KERNEL);
1129 	}
1130 	if (err) {
1131 		ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1132 		goto failed_mount3;
1133 	}
1134 
1135 #ifdef CONFIG_EXT2_FS_XATTR
1136 	sbi->s_ea_block_cache = ext2_xattr_create_cache();
1137 	if (!sbi->s_ea_block_cache) {
1138 		ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1139 		goto failed_mount3;
1140 	}
1141 #endif
1142 	/*
1143 	 * set up enough so that it can read an inode
1144 	 */
1145 	sb->s_op = &ext2_sops;
1146 	sb->s_export_op = &ext2_export_ops;
1147 	sb->s_xattr = ext2_xattr_handlers;
1148 
1149 #ifdef CONFIG_QUOTA
1150 	sb->dq_op = &dquot_operations;
1151 	sb->s_qcop = &ext2_quotactl_ops;
1152 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1153 #endif
1154 
1155 	root = ext2_iget(sb, EXT2_ROOT_INO);
1156 	if (IS_ERR(root)) {
1157 		ret = PTR_ERR(root);
1158 		goto failed_mount3;
1159 	}
1160 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1161 		iput(root);
1162 		ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1163 		goto failed_mount3;
1164 	}
1165 
1166 	sb->s_root = d_make_root(root);
1167 	if (!sb->s_root) {
1168 		ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1169 		ret = -ENOMEM;
1170 		goto failed_mount3;
1171 	}
1172 	if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1173 		ext2_msg(sb, KERN_WARNING,
1174 			"warning: mounting ext3 filesystem as ext2");
1175 	if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1176 		sb->s_flags |= MS_RDONLY;
1177 	ext2_write_super(sb);
1178 	return 0;
1179 
1180 cantfind_ext2:
1181 	if (!silent)
1182 		ext2_msg(sb, KERN_ERR,
1183 			"error: can't find an ext2 filesystem on dev %s.",
1184 			sb->s_id);
1185 	goto failed_mount;
1186 failed_mount3:
1187 	if (sbi->s_ea_block_cache)
1188 		ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1189 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
1190 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1191 	percpu_counter_destroy(&sbi->s_dirs_counter);
1192 failed_mount2:
1193 	for (i = 0; i < db_count; i++)
1194 		brelse(sbi->s_group_desc[i]);
1195 failed_mount_group_desc:
1196 	kfree(sbi->s_group_desc);
1197 	kfree(sbi->s_debts);
1198 failed_mount:
1199 	brelse(bh);
1200 failed_sbi:
1201 	sb->s_fs_info = NULL;
1202 	kfree(sbi->s_blockgroup_lock);
1203 	kfree(sbi);
1204 failed:
1205 	fs_put_dax(dax_dev);
1206 	return ret;
1207 }
1208 
1209 static void ext2_clear_super_error(struct super_block *sb)
1210 {
1211 	struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1212 
1213 	if (buffer_write_io_error(sbh)) {
1214 		/*
1215 		 * Oh, dear.  A previous attempt to write the
1216 		 * superblock failed.  This could happen because the
1217 		 * USB device was yanked out.  Or it could happen to
1218 		 * be a transient write error and maybe the block will
1219 		 * be remapped.  Nothing we can do but to retry the
1220 		 * write and hope for the best.
1221 		 */
1222 		ext2_msg(sb, KERN_ERR,
1223 		       "previous I/O error to superblock detected\n");
1224 		clear_buffer_write_io_error(sbh);
1225 		set_buffer_uptodate(sbh);
1226 	}
1227 }
1228 
1229 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1230 		     int wait)
1231 {
1232 	ext2_clear_super_error(sb);
1233 	spin_lock(&EXT2_SB(sb)->s_lock);
1234 	es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1235 	es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1236 	es->s_wtime = cpu_to_le32(get_seconds());
1237 	/* unlock before we do IO */
1238 	spin_unlock(&EXT2_SB(sb)->s_lock);
1239 	mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1240 	if (wait)
1241 		sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1242 }
1243 
1244 /*
1245  * In the second extended file system, it is not necessary to
1246  * write the super block since we use a mapping of the
1247  * disk super block in a buffer.
1248  *
1249  * However, this function is still used to set the fs valid
1250  * flags to 0.  We need to set this flag to 0 since the fs
1251  * may have been checked while mounted and e2fsck may have
1252  * set s_state to EXT2_VALID_FS after some corrections.
1253  */
1254 static int ext2_sync_fs(struct super_block *sb, int wait)
1255 {
1256 	struct ext2_sb_info *sbi = EXT2_SB(sb);
1257 	struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1258 
1259 	/*
1260 	 * Write quota structures to quota file, sync_blockdev() will write
1261 	 * them to disk later
1262 	 */
1263 	dquot_writeback_dquots(sb, -1);
1264 
1265 	spin_lock(&sbi->s_lock);
1266 	if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1267 		ext2_debug("setting valid to 0\n");
1268 		es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1269 	}
1270 	spin_unlock(&sbi->s_lock);
1271 	ext2_sync_super(sb, es, wait);
1272 	return 0;
1273 }
1274 
1275 static int ext2_freeze(struct super_block *sb)
1276 {
1277 	struct ext2_sb_info *sbi = EXT2_SB(sb);
1278 
1279 	/*
1280 	 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1281 	 * because we have unattached inodes and thus filesystem is not fully
1282 	 * consistent.
1283 	 */
1284 	if (atomic_long_read(&sb->s_remove_count)) {
1285 		ext2_sync_fs(sb, 1);
1286 		return 0;
1287 	}
1288 	/* Set EXT2_FS_VALID flag */
1289 	spin_lock(&sbi->s_lock);
1290 	sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1291 	spin_unlock(&sbi->s_lock);
1292 	ext2_sync_super(sb, sbi->s_es, 1);
1293 
1294 	return 0;
1295 }
1296 
1297 static int ext2_unfreeze(struct super_block *sb)
1298 {
1299 	/* Just write sb to clear EXT2_VALID_FS flag */
1300 	ext2_write_super(sb);
1301 
1302 	return 0;
1303 }
1304 
1305 static void ext2_write_super(struct super_block *sb)
1306 {
1307 	if (!sb_rdonly(sb))
1308 		ext2_sync_fs(sb, 1);
1309 }
1310 
1311 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1312 {
1313 	struct ext2_sb_info * sbi = EXT2_SB(sb);
1314 	struct ext2_super_block * es;
1315 	struct ext2_mount_options old_opts;
1316 	unsigned long old_sb_flags;
1317 	int err;
1318 
1319 	sync_filesystem(sb);
1320 	spin_lock(&sbi->s_lock);
1321 
1322 	/* Store the old options */
1323 	old_sb_flags = sb->s_flags;
1324 	old_opts.s_mount_opt = sbi->s_mount_opt;
1325 	old_opts.s_resuid = sbi->s_resuid;
1326 	old_opts.s_resgid = sbi->s_resgid;
1327 
1328 	/*
1329 	 * Allow the "check" option to be passed as a remount option.
1330 	 */
1331 	if (!parse_options(data, sb)) {
1332 		err = -EINVAL;
1333 		goto restore_opts;
1334 	}
1335 
1336 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1337 		((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1338 
1339 	es = sbi->s_es;
1340 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1341 		ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1342 			 "dax flag with busy inodes while remounting");
1343 		sbi->s_mount_opt ^= EXT2_MOUNT_DAX;
1344 	}
1345 	if ((bool)(*flags & MS_RDONLY) == sb_rdonly(sb)) {
1346 		spin_unlock(&sbi->s_lock);
1347 		return 0;
1348 	}
1349 	if (*flags & MS_RDONLY) {
1350 		if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1351 		    !(sbi->s_mount_state & EXT2_VALID_FS)) {
1352 			spin_unlock(&sbi->s_lock);
1353 			return 0;
1354 		}
1355 
1356 		/*
1357 		 * OK, we are remounting a valid rw partition rdonly, so set
1358 		 * the rdonly flag and then mark the partition as valid again.
1359 		 */
1360 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1361 		es->s_mtime = cpu_to_le32(get_seconds());
1362 		spin_unlock(&sbi->s_lock);
1363 
1364 		err = dquot_suspend(sb, -1);
1365 		if (err < 0) {
1366 			spin_lock(&sbi->s_lock);
1367 			goto restore_opts;
1368 		}
1369 
1370 		ext2_sync_super(sb, es, 1);
1371 	} else {
1372 		__le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1373 					       ~EXT2_FEATURE_RO_COMPAT_SUPP);
1374 		if (ret) {
1375 			ext2_msg(sb, KERN_WARNING,
1376 				"warning: couldn't remount RDWR because of "
1377 				"unsupported optional features (%x).",
1378 				le32_to_cpu(ret));
1379 			err = -EROFS;
1380 			goto restore_opts;
1381 		}
1382 		/*
1383 		 * Mounting a RDONLY partition read-write, so reread and
1384 		 * store the current valid flag.  (It may have been changed
1385 		 * by e2fsck since we originally mounted the partition.)
1386 		 */
1387 		sbi->s_mount_state = le16_to_cpu(es->s_state);
1388 		if (!ext2_setup_super (sb, es, 0))
1389 			sb->s_flags &= ~MS_RDONLY;
1390 		spin_unlock(&sbi->s_lock);
1391 
1392 		ext2_write_super(sb);
1393 
1394 		dquot_resume(sb, -1);
1395 	}
1396 
1397 	return 0;
1398 restore_opts:
1399 	sbi->s_mount_opt = old_opts.s_mount_opt;
1400 	sbi->s_resuid = old_opts.s_resuid;
1401 	sbi->s_resgid = old_opts.s_resgid;
1402 	sb->s_flags = old_sb_flags;
1403 	spin_unlock(&sbi->s_lock);
1404 	return err;
1405 }
1406 
1407 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1408 {
1409 	struct super_block *sb = dentry->d_sb;
1410 	struct ext2_sb_info *sbi = EXT2_SB(sb);
1411 	struct ext2_super_block *es = sbi->s_es;
1412 	u64 fsid;
1413 
1414 	spin_lock(&sbi->s_lock);
1415 
1416 	if (test_opt (sb, MINIX_DF))
1417 		sbi->s_overhead_last = 0;
1418 	else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1419 		unsigned long i, overhead = 0;
1420 		smp_rmb();
1421 
1422 		/*
1423 		 * Compute the overhead (FS structures). This is constant
1424 		 * for a given filesystem unless the number of block groups
1425 		 * changes so we cache the previous value until it does.
1426 		 */
1427 
1428 		/*
1429 		 * All of the blocks before first_data_block are
1430 		 * overhead
1431 		 */
1432 		overhead = le32_to_cpu(es->s_first_data_block);
1433 
1434 		/*
1435 		 * Add the overhead attributed to the superblock and
1436 		 * block group descriptors.  If the sparse superblocks
1437 		 * feature is turned on, then not all groups have this.
1438 		 */
1439 		for (i = 0; i < sbi->s_groups_count; i++)
1440 			overhead += ext2_bg_has_super(sb, i) +
1441 				ext2_bg_num_gdb(sb, i);
1442 
1443 		/*
1444 		 * Every block group has an inode bitmap, a block
1445 		 * bitmap, and an inode table.
1446 		 */
1447 		overhead += (sbi->s_groups_count *
1448 			     (2 + sbi->s_itb_per_group));
1449 		sbi->s_overhead_last = overhead;
1450 		smp_wmb();
1451 		sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1452 	}
1453 
1454 	buf->f_type = EXT2_SUPER_MAGIC;
1455 	buf->f_bsize = sb->s_blocksize;
1456 	buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1457 	buf->f_bfree = ext2_count_free_blocks(sb);
1458 	es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1459 	buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1460 	if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1461 		buf->f_bavail = 0;
1462 	buf->f_files = le32_to_cpu(es->s_inodes_count);
1463 	buf->f_ffree = ext2_count_free_inodes(sb);
1464 	es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1465 	buf->f_namelen = EXT2_NAME_LEN;
1466 	fsid = le64_to_cpup((void *)es->s_uuid) ^
1467 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1468 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1469 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1470 	spin_unlock(&sbi->s_lock);
1471 	return 0;
1472 }
1473 
1474 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1475 	int flags, const char *dev_name, void *data)
1476 {
1477 	return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1478 }
1479 
1480 #ifdef CONFIG_QUOTA
1481 
1482 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1483  * acquiring the locks... As quota files are never truncated and quota code
1484  * itself serializes the operations (and no one else should touch the files)
1485  * we don't have to be afraid of races */
1486 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1487 			       size_t len, loff_t off)
1488 {
1489 	struct inode *inode = sb_dqopt(sb)->files[type];
1490 	sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1491 	int err = 0;
1492 	int offset = off & (sb->s_blocksize - 1);
1493 	int tocopy;
1494 	size_t toread;
1495 	struct buffer_head tmp_bh;
1496 	struct buffer_head *bh;
1497 	loff_t i_size = i_size_read(inode);
1498 
1499 	if (off > i_size)
1500 		return 0;
1501 	if (off+len > i_size)
1502 		len = i_size-off;
1503 	toread = len;
1504 	while (toread > 0) {
1505 		tocopy = sb->s_blocksize - offset < toread ?
1506 				sb->s_blocksize - offset : toread;
1507 
1508 		tmp_bh.b_state = 0;
1509 		tmp_bh.b_size = sb->s_blocksize;
1510 		err = ext2_get_block(inode, blk, &tmp_bh, 0);
1511 		if (err < 0)
1512 			return err;
1513 		if (!buffer_mapped(&tmp_bh))	/* A hole? */
1514 			memset(data, 0, tocopy);
1515 		else {
1516 			bh = sb_bread(sb, tmp_bh.b_blocknr);
1517 			if (!bh)
1518 				return -EIO;
1519 			memcpy(data, bh->b_data+offset, tocopy);
1520 			brelse(bh);
1521 		}
1522 		offset = 0;
1523 		toread -= tocopy;
1524 		data += tocopy;
1525 		blk++;
1526 	}
1527 	return len;
1528 }
1529 
1530 /* Write to quotafile */
1531 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1532 				const char *data, size_t len, loff_t off)
1533 {
1534 	struct inode *inode = sb_dqopt(sb)->files[type];
1535 	sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1536 	int err = 0;
1537 	int offset = off & (sb->s_blocksize - 1);
1538 	int tocopy;
1539 	size_t towrite = len;
1540 	struct buffer_head tmp_bh;
1541 	struct buffer_head *bh;
1542 
1543 	while (towrite > 0) {
1544 		tocopy = sb->s_blocksize - offset < towrite ?
1545 				sb->s_blocksize - offset : towrite;
1546 
1547 		tmp_bh.b_state = 0;
1548 		tmp_bh.b_size = sb->s_blocksize;
1549 		err = ext2_get_block(inode, blk, &tmp_bh, 1);
1550 		if (err < 0)
1551 			goto out;
1552 		if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1553 			bh = sb_bread(sb, tmp_bh.b_blocknr);
1554 		else
1555 			bh = sb_getblk(sb, tmp_bh.b_blocknr);
1556 		if (unlikely(!bh)) {
1557 			err = -EIO;
1558 			goto out;
1559 		}
1560 		lock_buffer(bh);
1561 		memcpy(bh->b_data+offset, data, tocopy);
1562 		flush_dcache_page(bh->b_page);
1563 		set_buffer_uptodate(bh);
1564 		mark_buffer_dirty(bh);
1565 		unlock_buffer(bh);
1566 		brelse(bh);
1567 		offset = 0;
1568 		towrite -= tocopy;
1569 		data += tocopy;
1570 		blk++;
1571 	}
1572 out:
1573 	if (len == towrite)
1574 		return err;
1575 	if (inode->i_size < off+len-towrite)
1576 		i_size_write(inode, off+len-towrite);
1577 	inode->i_version++;
1578 	inode->i_mtime = inode->i_ctime = current_time(inode);
1579 	mark_inode_dirty(inode);
1580 	return len - towrite;
1581 }
1582 
1583 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1584 			 const struct path *path)
1585 {
1586 	int err;
1587 	struct inode *inode;
1588 
1589 	err = dquot_quota_on(sb, type, format_id, path);
1590 	if (err)
1591 		return err;
1592 
1593 	inode = d_inode(path->dentry);
1594 	inode_lock(inode);
1595 	EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1596 	inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1597 			S_NOATIME | S_IMMUTABLE);
1598 	inode_unlock(inode);
1599 	mark_inode_dirty(inode);
1600 
1601 	return 0;
1602 }
1603 
1604 static int ext2_quota_off(struct super_block *sb, int type)
1605 {
1606 	struct inode *inode = sb_dqopt(sb)->files[type];
1607 	int err;
1608 
1609 	if (!inode || !igrab(inode))
1610 		goto out;
1611 
1612 	err = dquot_quota_off(sb, type);
1613 	if (err)
1614 		goto out_put;
1615 
1616 	inode_lock(inode);
1617 	EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1618 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1619 	inode_unlock(inode);
1620 	mark_inode_dirty(inode);
1621 out_put:
1622 	iput(inode);
1623 	return err;
1624 out:
1625 	return dquot_quota_off(sb, type);
1626 }
1627 
1628 #endif
1629 
1630 static struct file_system_type ext2_fs_type = {
1631 	.owner		= THIS_MODULE,
1632 	.name		= "ext2",
1633 	.mount		= ext2_mount,
1634 	.kill_sb	= kill_block_super,
1635 	.fs_flags	= FS_REQUIRES_DEV,
1636 };
1637 MODULE_ALIAS_FS("ext2");
1638 
1639 static int __init init_ext2_fs(void)
1640 {
1641 	int err;
1642 
1643 	err = init_inodecache();
1644 	if (err)
1645 		return err;
1646         err = register_filesystem(&ext2_fs_type);
1647 	if (err)
1648 		goto out;
1649 	return 0;
1650 out:
1651 	destroy_inodecache();
1652 	return err;
1653 }
1654 
1655 static void __exit exit_ext2_fs(void)
1656 {
1657 	unregister_filesystem(&ext2_fs_type);
1658 	destroy_inodecache();
1659 }
1660 
1661 MODULE_AUTHOR("Remy Card and others");
1662 MODULE_DESCRIPTION("Second Extended Filesystem");
1663 MODULE_LICENSE("GPL");
1664 module_init(init_ext2_fs)
1665 module_exit(exit_ext2_fs)
1666