xref: /linux/fs/ext4/super.c (revision e15d5a53ea3239e537d3a0c4bdfce8a4ea4e0da6)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/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/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/cleancache.h>
43 #include <linux/uaccess.h>
44 #include <linux/iversion.h>
45 #include <linux/unicode.h>
46 
47 #include <linux/kthread.h>
48 #include <linux/freezer.h>
49 
50 #include "ext4.h"
51 #include "ext4_extents.h"	/* Needed for trace points definition */
52 #include "ext4_jbd2.h"
53 #include "xattr.h"
54 #include "acl.h"
55 #include "mballoc.h"
56 #include "fsmap.h"
57 
58 #define CREATE_TRACE_POINTS
59 #include <trace/events/ext4.h>
60 
61 static struct ext4_lazy_init *ext4_li_info;
62 static struct mutex ext4_li_mtx;
63 static struct ratelimit_state ext4_mount_msg_ratelimit;
64 
65 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
66 			     unsigned long journal_devnum);
67 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
68 static int ext4_commit_super(struct super_block *sb, int sync);
69 static void ext4_mark_recovery_complete(struct super_block *sb,
70 					struct ext4_super_block *es);
71 static void ext4_clear_journal_err(struct super_block *sb,
72 				   struct ext4_super_block *es);
73 static int ext4_sync_fs(struct super_block *sb, int wait);
74 static int ext4_remount(struct super_block *sb, int *flags, char *data);
75 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
76 static int ext4_unfreeze(struct super_block *sb);
77 static int ext4_freeze(struct super_block *sb);
78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
79 		       const char *dev_name, void *data);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
83 static void ext4_destroy_lazyinit_thread(void);
84 static void ext4_unregister_li_request(struct super_block *sb);
85 static void ext4_clear_request_list(void);
86 static struct inode *ext4_get_journal_inode(struct super_block *sb,
87 					    unsigned int journal_inum);
88 
89 /*
90  * Lock ordering
91  *
92  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
93  * i_mmap_rwsem (inode->i_mmap_rwsem)!
94  *
95  * page fault path:
96  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
97  *   page lock -> i_data_sem (rw)
98  *
99  * buffered write path:
100  * sb_start_write -> i_mutex -> mmap_sem
101  * sb_start_write -> i_mutex -> transaction start -> page lock ->
102  *   i_data_sem (rw)
103  *
104  * truncate:
105  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
106  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
107  *   i_data_sem (rw)
108  *
109  * direct IO:
110  * sb_start_write -> i_mutex -> mmap_sem
111  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
112  *
113  * writepages:
114  * transaction start -> page lock(s) -> i_data_sem (rw)
115  */
116 
117 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
118 static struct file_system_type ext2_fs_type = {
119 	.owner		= THIS_MODULE,
120 	.name		= "ext2",
121 	.mount		= ext4_mount,
122 	.kill_sb	= kill_block_super,
123 	.fs_flags	= FS_REQUIRES_DEV,
124 };
125 MODULE_ALIAS_FS("ext2");
126 MODULE_ALIAS("ext2");
127 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
128 #else
129 #define IS_EXT2_SB(sb) (0)
130 #endif
131 
132 
133 static struct file_system_type ext3_fs_type = {
134 	.owner		= THIS_MODULE,
135 	.name		= "ext3",
136 	.mount		= ext4_mount,
137 	.kill_sb	= kill_block_super,
138 	.fs_flags	= FS_REQUIRES_DEV,
139 };
140 MODULE_ALIAS_FS("ext3");
141 MODULE_ALIAS("ext3");
142 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
143 
144 /*
145  * This works like sb_bread() except it uses ERR_PTR for error
146  * returns.  Currently with sb_bread it's impossible to distinguish
147  * between ENOMEM and EIO situations (since both result in a NULL
148  * return.
149  */
150 struct buffer_head *
151 ext4_sb_bread(struct super_block *sb, sector_t block, int op_flags)
152 {
153 	struct buffer_head *bh = sb_getblk(sb, block);
154 
155 	if (bh == NULL)
156 		return ERR_PTR(-ENOMEM);
157 	if (buffer_uptodate(bh))
158 		return bh;
159 	ll_rw_block(REQ_OP_READ, REQ_META | op_flags, 1, &bh);
160 	wait_on_buffer(bh);
161 	if (buffer_uptodate(bh))
162 		return bh;
163 	put_bh(bh);
164 	return ERR_PTR(-EIO);
165 }
166 
167 static int ext4_verify_csum_type(struct super_block *sb,
168 				 struct ext4_super_block *es)
169 {
170 	if (!ext4_has_feature_metadata_csum(sb))
171 		return 1;
172 
173 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
174 }
175 
176 static __le32 ext4_superblock_csum(struct super_block *sb,
177 				   struct ext4_super_block *es)
178 {
179 	struct ext4_sb_info *sbi = EXT4_SB(sb);
180 	int offset = offsetof(struct ext4_super_block, s_checksum);
181 	__u32 csum;
182 
183 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
184 
185 	return cpu_to_le32(csum);
186 }
187 
188 static int ext4_superblock_csum_verify(struct super_block *sb,
189 				       struct ext4_super_block *es)
190 {
191 	if (!ext4_has_metadata_csum(sb))
192 		return 1;
193 
194 	return es->s_checksum == ext4_superblock_csum(sb, es);
195 }
196 
197 void ext4_superblock_csum_set(struct super_block *sb)
198 {
199 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
200 
201 	if (!ext4_has_metadata_csum(sb))
202 		return;
203 
204 	es->s_checksum = ext4_superblock_csum(sb, es);
205 }
206 
207 void *ext4_kvmalloc(size_t size, gfp_t flags)
208 {
209 	void *ret;
210 
211 	ret = kmalloc(size, flags | __GFP_NOWARN);
212 	if (!ret)
213 		ret = __vmalloc(size, flags, PAGE_KERNEL);
214 	return ret;
215 }
216 
217 void *ext4_kvzalloc(size_t size, gfp_t flags)
218 {
219 	void *ret;
220 
221 	ret = kzalloc(size, flags | __GFP_NOWARN);
222 	if (!ret)
223 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
224 	return ret;
225 }
226 
227 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
228 			       struct ext4_group_desc *bg)
229 {
230 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
231 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
232 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
233 }
234 
235 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
236 			       struct ext4_group_desc *bg)
237 {
238 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
239 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
240 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
241 }
242 
243 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
244 			      struct ext4_group_desc *bg)
245 {
246 	return le32_to_cpu(bg->bg_inode_table_lo) |
247 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
248 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
249 }
250 
251 __u32 ext4_free_group_clusters(struct super_block *sb,
252 			       struct ext4_group_desc *bg)
253 {
254 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
255 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
256 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
257 }
258 
259 __u32 ext4_free_inodes_count(struct super_block *sb,
260 			      struct ext4_group_desc *bg)
261 {
262 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
263 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
264 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
265 }
266 
267 __u32 ext4_used_dirs_count(struct super_block *sb,
268 			      struct ext4_group_desc *bg)
269 {
270 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
271 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
272 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
273 }
274 
275 __u32 ext4_itable_unused_count(struct super_block *sb,
276 			      struct ext4_group_desc *bg)
277 {
278 	return le16_to_cpu(bg->bg_itable_unused_lo) |
279 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
280 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
281 }
282 
283 void ext4_block_bitmap_set(struct super_block *sb,
284 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
285 {
286 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
287 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
288 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
289 }
290 
291 void ext4_inode_bitmap_set(struct super_block *sb,
292 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
293 {
294 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
295 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
296 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
297 }
298 
299 void ext4_inode_table_set(struct super_block *sb,
300 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
301 {
302 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
303 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
304 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
305 }
306 
307 void ext4_free_group_clusters_set(struct super_block *sb,
308 				  struct ext4_group_desc *bg, __u32 count)
309 {
310 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
311 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
312 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
313 }
314 
315 void ext4_free_inodes_set(struct super_block *sb,
316 			  struct ext4_group_desc *bg, __u32 count)
317 {
318 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
319 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
320 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
321 }
322 
323 void ext4_used_dirs_set(struct super_block *sb,
324 			  struct ext4_group_desc *bg, __u32 count)
325 {
326 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
327 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
328 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
329 }
330 
331 void ext4_itable_unused_set(struct super_block *sb,
332 			  struct ext4_group_desc *bg, __u32 count)
333 {
334 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
335 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
336 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
337 }
338 
339 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
340 {
341 	time64_t now = ktime_get_real_seconds();
342 
343 	now = clamp_val(now, 0, (1ull << 40) - 1);
344 
345 	*lo = cpu_to_le32(lower_32_bits(now));
346 	*hi = upper_32_bits(now);
347 }
348 
349 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
350 {
351 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
352 }
353 #define ext4_update_tstamp(es, tstamp) \
354 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
355 #define ext4_get_tstamp(es, tstamp) \
356 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
357 
358 static void __save_error_info(struct super_block *sb, const char *func,
359 			    unsigned int line)
360 {
361 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
362 
363 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
364 	if (bdev_read_only(sb->s_bdev))
365 		return;
366 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
367 	ext4_update_tstamp(es, s_last_error_time);
368 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
369 	es->s_last_error_line = cpu_to_le32(line);
370 	if (!es->s_first_error_time) {
371 		es->s_first_error_time = es->s_last_error_time;
372 		es->s_first_error_time_hi = es->s_last_error_time_hi;
373 		strncpy(es->s_first_error_func, func,
374 			sizeof(es->s_first_error_func));
375 		es->s_first_error_line = cpu_to_le32(line);
376 		es->s_first_error_ino = es->s_last_error_ino;
377 		es->s_first_error_block = es->s_last_error_block;
378 	}
379 	/*
380 	 * Start the daily error reporting function if it hasn't been
381 	 * started already
382 	 */
383 	if (!es->s_error_count)
384 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
385 	le32_add_cpu(&es->s_error_count, 1);
386 }
387 
388 static void save_error_info(struct super_block *sb, const char *func,
389 			    unsigned int line)
390 {
391 	__save_error_info(sb, func, line);
392 	ext4_commit_super(sb, 1);
393 }
394 
395 /*
396  * The del_gendisk() function uninitializes the disk-specific data
397  * structures, including the bdi structure, without telling anyone
398  * else.  Once this happens, any attempt to call mark_buffer_dirty()
399  * (for example, by ext4_commit_super), will cause a kernel OOPS.
400  * This is a kludge to prevent these oops until we can put in a proper
401  * hook in del_gendisk() to inform the VFS and file system layers.
402  */
403 static int block_device_ejected(struct super_block *sb)
404 {
405 	struct inode *bd_inode = sb->s_bdev->bd_inode;
406 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
407 
408 	return bdi->dev == NULL;
409 }
410 
411 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
412 {
413 	struct super_block		*sb = journal->j_private;
414 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
415 	int				error = is_journal_aborted(journal);
416 	struct ext4_journal_cb_entry	*jce;
417 
418 	BUG_ON(txn->t_state == T_FINISHED);
419 
420 	ext4_process_freed_data(sb, txn->t_tid);
421 
422 	spin_lock(&sbi->s_md_lock);
423 	while (!list_empty(&txn->t_private_list)) {
424 		jce = list_entry(txn->t_private_list.next,
425 				 struct ext4_journal_cb_entry, jce_list);
426 		list_del_init(&jce->jce_list);
427 		spin_unlock(&sbi->s_md_lock);
428 		jce->jce_func(sb, jce, error);
429 		spin_lock(&sbi->s_md_lock);
430 	}
431 	spin_unlock(&sbi->s_md_lock);
432 }
433 
434 static bool system_going_down(void)
435 {
436 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
437 		|| system_state == SYSTEM_RESTART;
438 }
439 
440 /* Deal with the reporting of failure conditions on a filesystem such as
441  * inconsistencies detected or read IO failures.
442  *
443  * On ext2, we can store the error state of the filesystem in the
444  * superblock.  That is not possible on ext4, because we may have other
445  * write ordering constraints on the superblock which prevent us from
446  * writing it out straight away; and given that the journal is about to
447  * be aborted, we can't rely on the current, or future, transactions to
448  * write out the superblock safely.
449  *
450  * We'll just use the jbd2_journal_abort() error code to record an error in
451  * the journal instead.  On recovery, the journal will complain about
452  * that error until we've noted it down and cleared it.
453  */
454 
455 static void ext4_handle_error(struct super_block *sb)
456 {
457 	if (test_opt(sb, WARN_ON_ERROR))
458 		WARN_ON_ONCE(1);
459 
460 	if (sb_rdonly(sb))
461 		return;
462 
463 	if (!test_opt(sb, ERRORS_CONT)) {
464 		journal_t *journal = EXT4_SB(sb)->s_journal;
465 
466 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
467 		if (journal)
468 			jbd2_journal_abort(journal, -EIO);
469 	}
470 	/*
471 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
472 	 * could panic during 'reboot -f' as the underlying device got already
473 	 * disabled.
474 	 */
475 	if (test_opt(sb, ERRORS_RO) || system_going_down()) {
476 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
477 		/*
478 		 * Make sure updated value of ->s_mount_flags will be visible
479 		 * before ->s_flags update
480 		 */
481 		smp_wmb();
482 		sb->s_flags |= SB_RDONLY;
483 	} else if (test_opt(sb, ERRORS_PANIC)) {
484 		if (EXT4_SB(sb)->s_journal &&
485 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
486 			return;
487 		panic("EXT4-fs (device %s): panic forced after error\n",
488 			sb->s_id);
489 	}
490 }
491 
492 #define ext4_error_ratelimit(sb)					\
493 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
494 			     "EXT4-fs error")
495 
496 void __ext4_error(struct super_block *sb, const char *function,
497 		  unsigned int line, const char *fmt, ...)
498 {
499 	struct va_format vaf;
500 	va_list args;
501 
502 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
503 		return;
504 
505 	trace_ext4_error(sb, function, line);
506 	if (ext4_error_ratelimit(sb)) {
507 		va_start(args, fmt);
508 		vaf.fmt = fmt;
509 		vaf.va = &args;
510 		printk(KERN_CRIT
511 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
512 		       sb->s_id, function, line, current->comm, &vaf);
513 		va_end(args);
514 	}
515 	save_error_info(sb, function, line);
516 	ext4_handle_error(sb);
517 }
518 
519 void __ext4_error_inode(struct inode *inode, const char *function,
520 			unsigned int line, ext4_fsblk_t block,
521 			const char *fmt, ...)
522 {
523 	va_list args;
524 	struct va_format vaf;
525 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
526 
527 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
528 		return;
529 
530 	trace_ext4_error(inode->i_sb, function, line);
531 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
532 	es->s_last_error_block = cpu_to_le64(block);
533 	if (ext4_error_ratelimit(inode->i_sb)) {
534 		va_start(args, fmt);
535 		vaf.fmt = fmt;
536 		vaf.va = &args;
537 		if (block)
538 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
539 			       "inode #%lu: block %llu: comm %s: %pV\n",
540 			       inode->i_sb->s_id, function, line, inode->i_ino,
541 			       block, current->comm, &vaf);
542 		else
543 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
544 			       "inode #%lu: comm %s: %pV\n",
545 			       inode->i_sb->s_id, function, line, inode->i_ino,
546 			       current->comm, &vaf);
547 		va_end(args);
548 	}
549 	save_error_info(inode->i_sb, function, line);
550 	ext4_handle_error(inode->i_sb);
551 }
552 
553 void __ext4_error_file(struct file *file, const char *function,
554 		       unsigned int line, ext4_fsblk_t block,
555 		       const char *fmt, ...)
556 {
557 	va_list args;
558 	struct va_format vaf;
559 	struct ext4_super_block *es;
560 	struct inode *inode = file_inode(file);
561 	char pathname[80], *path;
562 
563 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
564 		return;
565 
566 	trace_ext4_error(inode->i_sb, function, line);
567 	es = EXT4_SB(inode->i_sb)->s_es;
568 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
569 	if (ext4_error_ratelimit(inode->i_sb)) {
570 		path = file_path(file, pathname, sizeof(pathname));
571 		if (IS_ERR(path))
572 			path = "(unknown)";
573 		va_start(args, fmt);
574 		vaf.fmt = fmt;
575 		vaf.va = &args;
576 		if (block)
577 			printk(KERN_CRIT
578 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
579 			       "block %llu: comm %s: path %s: %pV\n",
580 			       inode->i_sb->s_id, function, line, inode->i_ino,
581 			       block, current->comm, path, &vaf);
582 		else
583 			printk(KERN_CRIT
584 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
585 			       "comm %s: path %s: %pV\n",
586 			       inode->i_sb->s_id, function, line, inode->i_ino,
587 			       current->comm, path, &vaf);
588 		va_end(args);
589 	}
590 	save_error_info(inode->i_sb, function, line);
591 	ext4_handle_error(inode->i_sb);
592 }
593 
594 const char *ext4_decode_error(struct super_block *sb, int errno,
595 			      char nbuf[16])
596 {
597 	char *errstr = NULL;
598 
599 	switch (errno) {
600 	case -EFSCORRUPTED:
601 		errstr = "Corrupt filesystem";
602 		break;
603 	case -EFSBADCRC:
604 		errstr = "Filesystem failed CRC";
605 		break;
606 	case -EIO:
607 		errstr = "IO failure";
608 		break;
609 	case -ENOMEM:
610 		errstr = "Out of memory";
611 		break;
612 	case -EROFS:
613 		if (!sb || (EXT4_SB(sb)->s_journal &&
614 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
615 			errstr = "Journal has aborted";
616 		else
617 			errstr = "Readonly filesystem";
618 		break;
619 	default:
620 		/* If the caller passed in an extra buffer for unknown
621 		 * errors, textualise them now.  Else we just return
622 		 * NULL. */
623 		if (nbuf) {
624 			/* Check for truncated error codes... */
625 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
626 				errstr = nbuf;
627 		}
628 		break;
629 	}
630 
631 	return errstr;
632 }
633 
634 /* __ext4_std_error decodes expected errors from journaling functions
635  * automatically and invokes the appropriate error response.  */
636 
637 void __ext4_std_error(struct super_block *sb, const char *function,
638 		      unsigned int line, int errno)
639 {
640 	char nbuf[16];
641 	const char *errstr;
642 
643 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
644 		return;
645 
646 	/* Special case: if the error is EROFS, and we're not already
647 	 * inside a transaction, then there's really no point in logging
648 	 * an error. */
649 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
650 		return;
651 
652 	if (ext4_error_ratelimit(sb)) {
653 		errstr = ext4_decode_error(sb, errno, nbuf);
654 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
655 		       sb->s_id, function, line, errstr);
656 	}
657 
658 	save_error_info(sb, function, line);
659 	ext4_handle_error(sb);
660 }
661 
662 /*
663  * ext4_abort is a much stronger failure handler than ext4_error.  The
664  * abort function may be used to deal with unrecoverable failures such
665  * as journal IO errors or ENOMEM at a critical moment in log management.
666  *
667  * We unconditionally force the filesystem into an ABORT|READONLY state,
668  * unless the error response on the fs has been set to panic in which
669  * case we take the easy way out and panic immediately.
670  */
671 
672 void __ext4_abort(struct super_block *sb, const char *function,
673 		unsigned int line, const char *fmt, ...)
674 {
675 	struct va_format vaf;
676 	va_list args;
677 
678 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
679 		return;
680 
681 	save_error_info(sb, function, line);
682 	va_start(args, fmt);
683 	vaf.fmt = fmt;
684 	vaf.va = &args;
685 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
686 	       sb->s_id, function, line, &vaf);
687 	va_end(args);
688 
689 	if (sb_rdonly(sb) == 0) {
690 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
691 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
692 		/*
693 		 * Make sure updated value of ->s_mount_flags will be visible
694 		 * before ->s_flags update
695 		 */
696 		smp_wmb();
697 		sb->s_flags |= SB_RDONLY;
698 		if (EXT4_SB(sb)->s_journal)
699 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
700 		save_error_info(sb, function, line);
701 	}
702 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
703 		if (EXT4_SB(sb)->s_journal &&
704 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
705 			return;
706 		panic("EXT4-fs panic from previous error\n");
707 	}
708 }
709 
710 void __ext4_msg(struct super_block *sb,
711 		const char *prefix, const char *fmt, ...)
712 {
713 	struct va_format vaf;
714 	va_list args;
715 
716 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
717 		return;
718 
719 	va_start(args, fmt);
720 	vaf.fmt = fmt;
721 	vaf.va = &args;
722 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
723 	va_end(args);
724 }
725 
726 #define ext4_warning_ratelimit(sb)					\
727 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
728 			     "EXT4-fs warning")
729 
730 void __ext4_warning(struct super_block *sb, const char *function,
731 		    unsigned int line, const char *fmt, ...)
732 {
733 	struct va_format vaf;
734 	va_list args;
735 
736 	if (!ext4_warning_ratelimit(sb))
737 		return;
738 
739 	va_start(args, fmt);
740 	vaf.fmt = fmt;
741 	vaf.va = &args;
742 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
743 	       sb->s_id, function, line, &vaf);
744 	va_end(args);
745 }
746 
747 void __ext4_warning_inode(const struct inode *inode, const char *function,
748 			  unsigned int line, const char *fmt, ...)
749 {
750 	struct va_format vaf;
751 	va_list args;
752 
753 	if (!ext4_warning_ratelimit(inode->i_sb))
754 		return;
755 
756 	va_start(args, fmt);
757 	vaf.fmt = fmt;
758 	vaf.va = &args;
759 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
760 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
761 	       function, line, inode->i_ino, current->comm, &vaf);
762 	va_end(args);
763 }
764 
765 void __ext4_grp_locked_error(const char *function, unsigned int line,
766 			     struct super_block *sb, ext4_group_t grp,
767 			     unsigned long ino, ext4_fsblk_t block,
768 			     const char *fmt, ...)
769 __releases(bitlock)
770 __acquires(bitlock)
771 {
772 	struct va_format vaf;
773 	va_list args;
774 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
775 
776 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
777 		return;
778 
779 	trace_ext4_error(sb, function, line);
780 	es->s_last_error_ino = cpu_to_le32(ino);
781 	es->s_last_error_block = cpu_to_le64(block);
782 	__save_error_info(sb, function, line);
783 
784 	if (ext4_error_ratelimit(sb)) {
785 		va_start(args, fmt);
786 		vaf.fmt = fmt;
787 		vaf.va = &args;
788 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
789 		       sb->s_id, function, line, grp);
790 		if (ino)
791 			printk(KERN_CONT "inode %lu: ", ino);
792 		if (block)
793 			printk(KERN_CONT "block %llu:",
794 			       (unsigned long long) block);
795 		printk(KERN_CONT "%pV\n", &vaf);
796 		va_end(args);
797 	}
798 
799 	if (test_opt(sb, WARN_ON_ERROR))
800 		WARN_ON_ONCE(1);
801 
802 	if (test_opt(sb, ERRORS_CONT)) {
803 		ext4_commit_super(sb, 0);
804 		return;
805 	}
806 
807 	ext4_unlock_group(sb, grp);
808 	ext4_commit_super(sb, 1);
809 	ext4_handle_error(sb);
810 	/*
811 	 * We only get here in the ERRORS_RO case; relocking the group
812 	 * may be dangerous, but nothing bad will happen since the
813 	 * filesystem will have already been marked read/only and the
814 	 * journal has been aborted.  We return 1 as a hint to callers
815 	 * who might what to use the return value from
816 	 * ext4_grp_locked_error() to distinguish between the
817 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
818 	 * aggressively from the ext4 function in question, with a
819 	 * more appropriate error code.
820 	 */
821 	ext4_lock_group(sb, grp);
822 	return;
823 }
824 
825 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
826 				     ext4_group_t group,
827 				     unsigned int flags)
828 {
829 	struct ext4_sb_info *sbi = EXT4_SB(sb);
830 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
831 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
832 	int ret;
833 
834 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
835 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
836 					    &grp->bb_state);
837 		if (!ret)
838 			percpu_counter_sub(&sbi->s_freeclusters_counter,
839 					   grp->bb_free);
840 	}
841 
842 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
843 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
844 					    &grp->bb_state);
845 		if (!ret && gdp) {
846 			int count;
847 
848 			count = ext4_free_inodes_count(sb, gdp);
849 			percpu_counter_sub(&sbi->s_freeinodes_counter,
850 					   count);
851 		}
852 	}
853 }
854 
855 void ext4_update_dynamic_rev(struct super_block *sb)
856 {
857 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
858 
859 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
860 		return;
861 
862 	ext4_warning(sb,
863 		     "updating to rev %d because of new feature flag, "
864 		     "running e2fsck is recommended",
865 		     EXT4_DYNAMIC_REV);
866 
867 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
868 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
869 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
870 	/* leave es->s_feature_*compat flags alone */
871 	/* es->s_uuid will be set by e2fsck if empty */
872 
873 	/*
874 	 * The rest of the superblock fields should be zero, and if not it
875 	 * means they are likely already in use, so leave them alone.  We
876 	 * can leave it up to e2fsck to clean up any inconsistencies there.
877 	 */
878 }
879 
880 /*
881  * Open the external journal device
882  */
883 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
884 {
885 	struct block_device *bdev;
886 	char b[BDEVNAME_SIZE];
887 
888 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
889 	if (IS_ERR(bdev))
890 		goto fail;
891 	return bdev;
892 
893 fail:
894 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
895 			__bdevname(dev, b), PTR_ERR(bdev));
896 	return NULL;
897 }
898 
899 /*
900  * Release the journal device
901  */
902 static void ext4_blkdev_put(struct block_device *bdev)
903 {
904 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
905 }
906 
907 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
908 {
909 	struct block_device *bdev;
910 	bdev = sbi->journal_bdev;
911 	if (bdev) {
912 		ext4_blkdev_put(bdev);
913 		sbi->journal_bdev = NULL;
914 	}
915 }
916 
917 static inline struct inode *orphan_list_entry(struct list_head *l)
918 {
919 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
920 }
921 
922 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
923 {
924 	struct list_head *l;
925 
926 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
927 		 le32_to_cpu(sbi->s_es->s_last_orphan));
928 
929 	printk(KERN_ERR "sb_info orphan list:\n");
930 	list_for_each(l, &sbi->s_orphan) {
931 		struct inode *inode = orphan_list_entry(l);
932 		printk(KERN_ERR "  "
933 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
934 		       inode->i_sb->s_id, inode->i_ino, inode,
935 		       inode->i_mode, inode->i_nlink,
936 		       NEXT_ORPHAN(inode));
937 	}
938 }
939 
940 #ifdef CONFIG_QUOTA
941 static int ext4_quota_off(struct super_block *sb, int type);
942 
943 static inline void ext4_quota_off_umount(struct super_block *sb)
944 {
945 	int type;
946 
947 	/* Use our quota_off function to clear inode flags etc. */
948 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
949 		ext4_quota_off(sb, type);
950 }
951 
952 /*
953  * This is a helper function which is used in the mount/remount
954  * codepaths (which holds s_umount) to fetch the quota file name.
955  */
956 static inline char *get_qf_name(struct super_block *sb,
957 				struct ext4_sb_info *sbi,
958 				int type)
959 {
960 	return rcu_dereference_protected(sbi->s_qf_names[type],
961 					 lockdep_is_held(&sb->s_umount));
962 }
963 #else
964 static inline void ext4_quota_off_umount(struct super_block *sb)
965 {
966 }
967 #endif
968 
969 static void ext4_put_super(struct super_block *sb)
970 {
971 	struct ext4_sb_info *sbi = EXT4_SB(sb);
972 	struct ext4_super_block *es = sbi->s_es;
973 	int aborted = 0;
974 	int i, err;
975 
976 	ext4_unregister_li_request(sb);
977 	ext4_quota_off_umount(sb);
978 
979 	destroy_workqueue(sbi->rsv_conversion_wq);
980 
981 	if (sbi->s_journal) {
982 		aborted = is_journal_aborted(sbi->s_journal);
983 		err = jbd2_journal_destroy(sbi->s_journal);
984 		sbi->s_journal = NULL;
985 		if ((err < 0) && !aborted)
986 			ext4_abort(sb, "Couldn't clean up the journal");
987 	}
988 
989 	ext4_unregister_sysfs(sb);
990 	ext4_es_unregister_shrinker(sbi);
991 	del_timer_sync(&sbi->s_err_report);
992 	ext4_release_system_zone(sb);
993 	ext4_mb_release(sb);
994 	ext4_ext_release(sb);
995 
996 	if (!sb_rdonly(sb) && !aborted) {
997 		ext4_clear_feature_journal_needs_recovery(sb);
998 		es->s_state = cpu_to_le16(sbi->s_mount_state);
999 	}
1000 	if (!sb_rdonly(sb))
1001 		ext4_commit_super(sb, 1);
1002 
1003 	for (i = 0; i < sbi->s_gdb_count; i++)
1004 		brelse(sbi->s_group_desc[i]);
1005 	kvfree(sbi->s_group_desc);
1006 	kvfree(sbi->s_flex_groups);
1007 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1008 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1009 	percpu_counter_destroy(&sbi->s_dirs_counter);
1010 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1011 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
1012 #ifdef CONFIG_QUOTA
1013 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1014 		kfree(get_qf_name(sb, sbi, i));
1015 #endif
1016 
1017 	/* Debugging code just in case the in-memory inode orphan list
1018 	 * isn't empty.  The on-disk one can be non-empty if we've
1019 	 * detected an error and taken the fs readonly, but the
1020 	 * in-memory list had better be clean by this point. */
1021 	if (!list_empty(&sbi->s_orphan))
1022 		dump_orphan_list(sb, sbi);
1023 	J_ASSERT(list_empty(&sbi->s_orphan));
1024 
1025 	sync_blockdev(sb->s_bdev);
1026 	invalidate_bdev(sb->s_bdev);
1027 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
1028 		/*
1029 		 * Invalidate the journal device's buffers.  We don't want them
1030 		 * floating about in memory - the physical journal device may
1031 		 * hotswapped, and it breaks the `ro-after' testing code.
1032 		 */
1033 		sync_blockdev(sbi->journal_bdev);
1034 		invalidate_bdev(sbi->journal_bdev);
1035 		ext4_blkdev_remove(sbi);
1036 	}
1037 
1038 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1039 	sbi->s_ea_inode_cache = NULL;
1040 
1041 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1042 	sbi->s_ea_block_cache = NULL;
1043 
1044 	if (sbi->s_mmp_tsk)
1045 		kthread_stop(sbi->s_mmp_tsk);
1046 	brelse(sbi->s_sbh);
1047 	sb->s_fs_info = NULL;
1048 	/*
1049 	 * Now that we are completely done shutting down the
1050 	 * superblock, we need to actually destroy the kobject.
1051 	 */
1052 	kobject_put(&sbi->s_kobj);
1053 	wait_for_completion(&sbi->s_kobj_unregister);
1054 	if (sbi->s_chksum_driver)
1055 		crypto_free_shash(sbi->s_chksum_driver);
1056 	kfree(sbi->s_blockgroup_lock);
1057 	fs_put_dax(sbi->s_daxdev);
1058 #ifdef CONFIG_UNICODE
1059 	utf8_unload(sbi->s_encoding);
1060 #endif
1061 	kfree(sbi);
1062 }
1063 
1064 static struct kmem_cache *ext4_inode_cachep;
1065 
1066 /*
1067  * Called inside transaction, so use GFP_NOFS
1068  */
1069 static struct inode *ext4_alloc_inode(struct super_block *sb)
1070 {
1071 	struct ext4_inode_info *ei;
1072 
1073 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1074 	if (!ei)
1075 		return NULL;
1076 
1077 	inode_set_iversion(&ei->vfs_inode, 1);
1078 	spin_lock_init(&ei->i_raw_lock);
1079 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1080 	spin_lock_init(&ei->i_prealloc_lock);
1081 	ext4_es_init_tree(&ei->i_es_tree);
1082 	rwlock_init(&ei->i_es_lock);
1083 	INIT_LIST_HEAD(&ei->i_es_list);
1084 	ei->i_es_all_nr = 0;
1085 	ei->i_es_shk_nr = 0;
1086 	ei->i_es_shrink_lblk = 0;
1087 	ei->i_reserved_data_blocks = 0;
1088 	ei->i_da_metadata_calc_len = 0;
1089 	ei->i_da_metadata_calc_last_lblock = 0;
1090 	spin_lock_init(&(ei->i_block_reservation_lock));
1091 	ext4_init_pending_tree(&ei->i_pending_tree);
1092 #ifdef CONFIG_QUOTA
1093 	ei->i_reserved_quota = 0;
1094 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1095 #endif
1096 	ei->jinode = NULL;
1097 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1098 	spin_lock_init(&ei->i_completed_io_lock);
1099 	ei->i_sync_tid = 0;
1100 	ei->i_datasync_tid = 0;
1101 	atomic_set(&ei->i_unwritten, 0);
1102 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1103 	return &ei->vfs_inode;
1104 }
1105 
1106 static int ext4_drop_inode(struct inode *inode)
1107 {
1108 	int drop = generic_drop_inode(inode);
1109 
1110 	trace_ext4_drop_inode(inode, drop);
1111 	return drop;
1112 }
1113 
1114 static void ext4_free_in_core_inode(struct inode *inode)
1115 {
1116 	fscrypt_free_inode(inode);
1117 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1118 }
1119 
1120 static void ext4_destroy_inode(struct inode *inode)
1121 {
1122 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1123 		ext4_msg(inode->i_sb, KERN_ERR,
1124 			 "Inode %lu (%p): orphan list check failed!",
1125 			 inode->i_ino, EXT4_I(inode));
1126 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1127 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1128 				true);
1129 		dump_stack();
1130 	}
1131 }
1132 
1133 static void init_once(void *foo)
1134 {
1135 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1136 
1137 	INIT_LIST_HEAD(&ei->i_orphan);
1138 	init_rwsem(&ei->xattr_sem);
1139 	init_rwsem(&ei->i_data_sem);
1140 	init_rwsem(&ei->i_mmap_sem);
1141 	inode_init_once(&ei->vfs_inode);
1142 }
1143 
1144 static int __init init_inodecache(void)
1145 {
1146 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1147 				sizeof(struct ext4_inode_info), 0,
1148 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1149 					SLAB_ACCOUNT),
1150 				offsetof(struct ext4_inode_info, i_data),
1151 				sizeof_field(struct ext4_inode_info, i_data),
1152 				init_once);
1153 	if (ext4_inode_cachep == NULL)
1154 		return -ENOMEM;
1155 	return 0;
1156 }
1157 
1158 static void destroy_inodecache(void)
1159 {
1160 	/*
1161 	 * Make sure all delayed rcu free inodes are flushed before we
1162 	 * destroy cache.
1163 	 */
1164 	rcu_barrier();
1165 	kmem_cache_destroy(ext4_inode_cachep);
1166 }
1167 
1168 void ext4_clear_inode(struct inode *inode)
1169 {
1170 	invalidate_inode_buffers(inode);
1171 	clear_inode(inode);
1172 	dquot_drop(inode);
1173 	ext4_discard_preallocations(inode);
1174 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1175 	if (EXT4_I(inode)->jinode) {
1176 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1177 					       EXT4_I(inode)->jinode);
1178 		jbd2_free_inode(EXT4_I(inode)->jinode);
1179 		EXT4_I(inode)->jinode = NULL;
1180 	}
1181 	fscrypt_put_encryption_info(inode);
1182 }
1183 
1184 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1185 					u64 ino, u32 generation)
1186 {
1187 	struct inode *inode;
1188 
1189 	/*
1190 	 * Currently we don't know the generation for parent directory, so
1191 	 * a generation of 0 means "accept any"
1192 	 */
1193 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1194 	if (IS_ERR(inode))
1195 		return ERR_CAST(inode);
1196 	if (generation && inode->i_generation != generation) {
1197 		iput(inode);
1198 		return ERR_PTR(-ESTALE);
1199 	}
1200 
1201 	return inode;
1202 }
1203 
1204 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1205 					int fh_len, int fh_type)
1206 {
1207 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1208 				    ext4_nfs_get_inode);
1209 }
1210 
1211 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1212 					int fh_len, int fh_type)
1213 {
1214 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1215 				    ext4_nfs_get_inode);
1216 }
1217 
1218 static int ext4_nfs_commit_metadata(struct inode *inode)
1219 {
1220 	struct writeback_control wbc = {
1221 		.sync_mode = WB_SYNC_ALL
1222 	};
1223 
1224 	trace_ext4_nfs_commit_metadata(inode);
1225 	return ext4_write_inode(inode, &wbc);
1226 }
1227 
1228 /*
1229  * Try to release metadata pages (indirect blocks, directories) which are
1230  * mapped via the block device.  Since these pages could have journal heads
1231  * which would prevent try_to_free_buffers() from freeing them, we must use
1232  * jbd2 layer's try_to_free_buffers() function to release them.
1233  */
1234 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1235 				 gfp_t wait)
1236 {
1237 	journal_t *journal = EXT4_SB(sb)->s_journal;
1238 
1239 	WARN_ON(PageChecked(page));
1240 	if (!page_has_buffers(page))
1241 		return 0;
1242 	if (journal)
1243 		return jbd2_journal_try_to_free_buffers(journal, page,
1244 						wait & ~__GFP_DIRECT_RECLAIM);
1245 	return try_to_free_buffers(page);
1246 }
1247 
1248 #ifdef CONFIG_FS_ENCRYPTION
1249 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1250 {
1251 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1252 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1253 }
1254 
1255 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1256 							void *fs_data)
1257 {
1258 	handle_t *handle = fs_data;
1259 	int res, res2, credits, retries = 0;
1260 
1261 	/*
1262 	 * Encrypting the root directory is not allowed because e2fsck expects
1263 	 * lost+found to exist and be unencrypted, and encrypting the root
1264 	 * directory would imply encrypting the lost+found directory as well as
1265 	 * the filename "lost+found" itself.
1266 	 */
1267 	if (inode->i_ino == EXT4_ROOT_INO)
1268 		return -EPERM;
1269 
1270 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1271 		return -EINVAL;
1272 
1273 	res = ext4_convert_inline_data(inode);
1274 	if (res)
1275 		return res;
1276 
1277 	/*
1278 	 * If a journal handle was specified, then the encryption context is
1279 	 * being set on a new inode via inheritance and is part of a larger
1280 	 * transaction to create the inode.  Otherwise the encryption context is
1281 	 * being set on an existing inode in its own transaction.  Only in the
1282 	 * latter case should the "retry on ENOSPC" logic be used.
1283 	 */
1284 
1285 	if (handle) {
1286 		res = ext4_xattr_set_handle(handle, inode,
1287 					    EXT4_XATTR_INDEX_ENCRYPTION,
1288 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1289 					    ctx, len, 0);
1290 		if (!res) {
1291 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1292 			ext4_clear_inode_state(inode,
1293 					EXT4_STATE_MAY_INLINE_DATA);
1294 			/*
1295 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1296 			 * S_DAX may be disabled
1297 			 */
1298 			ext4_set_inode_flags(inode);
1299 		}
1300 		return res;
1301 	}
1302 
1303 	res = dquot_initialize(inode);
1304 	if (res)
1305 		return res;
1306 retry:
1307 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1308 				     &credits);
1309 	if (res)
1310 		return res;
1311 
1312 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1313 	if (IS_ERR(handle))
1314 		return PTR_ERR(handle);
1315 
1316 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1317 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1318 				    ctx, len, 0);
1319 	if (!res) {
1320 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1321 		/*
1322 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1323 		 * S_DAX may be disabled
1324 		 */
1325 		ext4_set_inode_flags(inode);
1326 		res = ext4_mark_inode_dirty(handle, inode);
1327 		if (res)
1328 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1329 	}
1330 	res2 = ext4_journal_stop(handle);
1331 
1332 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1333 		goto retry;
1334 	if (!res)
1335 		res = res2;
1336 	return res;
1337 }
1338 
1339 static bool ext4_dummy_context(struct inode *inode)
1340 {
1341 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1342 }
1343 
1344 static const struct fscrypt_operations ext4_cryptops = {
1345 	.key_prefix		= "ext4:",
1346 	.get_context		= ext4_get_context,
1347 	.set_context		= ext4_set_context,
1348 	.dummy_context		= ext4_dummy_context,
1349 	.empty_dir		= ext4_empty_dir,
1350 	.max_namelen		= EXT4_NAME_LEN,
1351 };
1352 #endif
1353 
1354 #ifdef CONFIG_QUOTA
1355 static const char * const quotatypes[] = INITQFNAMES;
1356 #define QTYPE2NAME(t) (quotatypes[t])
1357 
1358 static int ext4_write_dquot(struct dquot *dquot);
1359 static int ext4_acquire_dquot(struct dquot *dquot);
1360 static int ext4_release_dquot(struct dquot *dquot);
1361 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1362 static int ext4_write_info(struct super_block *sb, int type);
1363 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1364 			 const struct path *path);
1365 static int ext4_quota_on_mount(struct super_block *sb, int type);
1366 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1367 			       size_t len, loff_t off);
1368 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1369 				const char *data, size_t len, loff_t off);
1370 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1371 			     unsigned int flags);
1372 static int ext4_enable_quotas(struct super_block *sb);
1373 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1374 
1375 static struct dquot **ext4_get_dquots(struct inode *inode)
1376 {
1377 	return EXT4_I(inode)->i_dquot;
1378 }
1379 
1380 static const struct dquot_operations ext4_quota_operations = {
1381 	.get_reserved_space	= ext4_get_reserved_space,
1382 	.write_dquot		= ext4_write_dquot,
1383 	.acquire_dquot		= ext4_acquire_dquot,
1384 	.release_dquot		= ext4_release_dquot,
1385 	.mark_dirty		= ext4_mark_dquot_dirty,
1386 	.write_info		= ext4_write_info,
1387 	.alloc_dquot		= dquot_alloc,
1388 	.destroy_dquot		= dquot_destroy,
1389 	.get_projid		= ext4_get_projid,
1390 	.get_inode_usage	= ext4_get_inode_usage,
1391 	.get_next_id		= ext4_get_next_id,
1392 };
1393 
1394 static const struct quotactl_ops ext4_qctl_operations = {
1395 	.quota_on	= ext4_quota_on,
1396 	.quota_off	= ext4_quota_off,
1397 	.quota_sync	= dquot_quota_sync,
1398 	.get_state	= dquot_get_state,
1399 	.set_info	= dquot_set_dqinfo,
1400 	.get_dqblk	= dquot_get_dqblk,
1401 	.set_dqblk	= dquot_set_dqblk,
1402 	.get_nextdqblk	= dquot_get_next_dqblk,
1403 };
1404 #endif
1405 
1406 static const struct super_operations ext4_sops = {
1407 	.alloc_inode	= ext4_alloc_inode,
1408 	.free_inode	= ext4_free_in_core_inode,
1409 	.destroy_inode	= ext4_destroy_inode,
1410 	.write_inode	= ext4_write_inode,
1411 	.dirty_inode	= ext4_dirty_inode,
1412 	.drop_inode	= ext4_drop_inode,
1413 	.evict_inode	= ext4_evict_inode,
1414 	.put_super	= ext4_put_super,
1415 	.sync_fs	= ext4_sync_fs,
1416 	.freeze_fs	= ext4_freeze,
1417 	.unfreeze_fs	= ext4_unfreeze,
1418 	.statfs		= ext4_statfs,
1419 	.remount_fs	= ext4_remount,
1420 	.show_options	= ext4_show_options,
1421 #ifdef CONFIG_QUOTA
1422 	.quota_read	= ext4_quota_read,
1423 	.quota_write	= ext4_quota_write,
1424 	.get_dquots	= ext4_get_dquots,
1425 #endif
1426 	.bdev_try_to_free_page = bdev_try_to_free_page,
1427 };
1428 
1429 static const struct export_operations ext4_export_ops = {
1430 	.fh_to_dentry = ext4_fh_to_dentry,
1431 	.fh_to_parent = ext4_fh_to_parent,
1432 	.get_parent = ext4_get_parent,
1433 	.commit_metadata = ext4_nfs_commit_metadata,
1434 };
1435 
1436 enum {
1437 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1438 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1439 	Opt_nouid32, Opt_debug, Opt_removed,
1440 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1441 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1442 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1443 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1444 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1445 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1446 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1447 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1448 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1449 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1450 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1451 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1452 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1453 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1454 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1455 	Opt_dioread_nolock, Opt_dioread_lock,
1456 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1457 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1458 };
1459 
1460 static const match_table_t tokens = {
1461 	{Opt_bsd_df, "bsddf"},
1462 	{Opt_minix_df, "minixdf"},
1463 	{Opt_grpid, "grpid"},
1464 	{Opt_grpid, "bsdgroups"},
1465 	{Opt_nogrpid, "nogrpid"},
1466 	{Opt_nogrpid, "sysvgroups"},
1467 	{Opt_resgid, "resgid=%u"},
1468 	{Opt_resuid, "resuid=%u"},
1469 	{Opt_sb, "sb=%u"},
1470 	{Opt_err_cont, "errors=continue"},
1471 	{Opt_err_panic, "errors=panic"},
1472 	{Opt_err_ro, "errors=remount-ro"},
1473 	{Opt_nouid32, "nouid32"},
1474 	{Opt_debug, "debug"},
1475 	{Opt_removed, "oldalloc"},
1476 	{Opt_removed, "orlov"},
1477 	{Opt_user_xattr, "user_xattr"},
1478 	{Opt_nouser_xattr, "nouser_xattr"},
1479 	{Opt_acl, "acl"},
1480 	{Opt_noacl, "noacl"},
1481 	{Opt_noload, "norecovery"},
1482 	{Opt_noload, "noload"},
1483 	{Opt_removed, "nobh"},
1484 	{Opt_removed, "bh"},
1485 	{Opt_commit, "commit=%u"},
1486 	{Opt_min_batch_time, "min_batch_time=%u"},
1487 	{Opt_max_batch_time, "max_batch_time=%u"},
1488 	{Opt_journal_dev, "journal_dev=%u"},
1489 	{Opt_journal_path, "journal_path=%s"},
1490 	{Opt_journal_checksum, "journal_checksum"},
1491 	{Opt_nojournal_checksum, "nojournal_checksum"},
1492 	{Opt_journal_async_commit, "journal_async_commit"},
1493 	{Opt_abort, "abort"},
1494 	{Opt_data_journal, "data=journal"},
1495 	{Opt_data_ordered, "data=ordered"},
1496 	{Opt_data_writeback, "data=writeback"},
1497 	{Opt_data_err_abort, "data_err=abort"},
1498 	{Opt_data_err_ignore, "data_err=ignore"},
1499 	{Opt_offusrjquota, "usrjquota="},
1500 	{Opt_usrjquota, "usrjquota=%s"},
1501 	{Opt_offgrpjquota, "grpjquota="},
1502 	{Opt_grpjquota, "grpjquota=%s"},
1503 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1504 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1505 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1506 	{Opt_grpquota, "grpquota"},
1507 	{Opt_noquota, "noquota"},
1508 	{Opt_quota, "quota"},
1509 	{Opt_usrquota, "usrquota"},
1510 	{Opt_prjquota, "prjquota"},
1511 	{Opt_barrier, "barrier=%u"},
1512 	{Opt_barrier, "barrier"},
1513 	{Opt_nobarrier, "nobarrier"},
1514 	{Opt_i_version, "i_version"},
1515 	{Opt_dax, "dax"},
1516 	{Opt_stripe, "stripe=%u"},
1517 	{Opt_delalloc, "delalloc"},
1518 	{Opt_warn_on_error, "warn_on_error"},
1519 	{Opt_nowarn_on_error, "nowarn_on_error"},
1520 	{Opt_lazytime, "lazytime"},
1521 	{Opt_nolazytime, "nolazytime"},
1522 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1523 	{Opt_nodelalloc, "nodelalloc"},
1524 	{Opt_removed, "mblk_io_submit"},
1525 	{Opt_removed, "nomblk_io_submit"},
1526 	{Opt_block_validity, "block_validity"},
1527 	{Opt_noblock_validity, "noblock_validity"},
1528 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1529 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1530 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1531 	{Opt_auto_da_alloc, "auto_da_alloc"},
1532 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1533 	{Opt_dioread_nolock, "dioread_nolock"},
1534 	{Opt_dioread_lock, "dioread_lock"},
1535 	{Opt_discard, "discard"},
1536 	{Opt_nodiscard, "nodiscard"},
1537 	{Opt_init_itable, "init_itable=%u"},
1538 	{Opt_init_itable, "init_itable"},
1539 	{Opt_noinit_itable, "noinit_itable"},
1540 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1541 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1542 	{Opt_nombcache, "nombcache"},
1543 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1544 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1545 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1546 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1547 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1548 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1549 	{Opt_err, NULL},
1550 };
1551 
1552 static ext4_fsblk_t get_sb_block(void **data)
1553 {
1554 	ext4_fsblk_t	sb_block;
1555 	char		*options = (char *) *data;
1556 
1557 	if (!options || strncmp(options, "sb=", 3) != 0)
1558 		return 1;	/* Default location */
1559 
1560 	options += 3;
1561 	/* TODO: use simple_strtoll with >32bit ext4 */
1562 	sb_block = simple_strtoul(options, &options, 0);
1563 	if (*options && *options != ',') {
1564 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1565 		       (char *) *data);
1566 		return 1;
1567 	}
1568 	if (*options == ',')
1569 		options++;
1570 	*data = (void *) options;
1571 
1572 	return sb_block;
1573 }
1574 
1575 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1576 static const char deprecated_msg[] =
1577 	"Mount option \"%s\" will be removed by %s\n"
1578 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1579 
1580 #ifdef CONFIG_QUOTA
1581 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1582 {
1583 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1584 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1585 	int ret = -1;
1586 
1587 	if (sb_any_quota_loaded(sb) && !old_qname) {
1588 		ext4_msg(sb, KERN_ERR,
1589 			"Cannot change journaled "
1590 			"quota options when quota turned on");
1591 		return -1;
1592 	}
1593 	if (ext4_has_feature_quota(sb)) {
1594 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1595 			 "ignored when QUOTA feature is enabled");
1596 		return 1;
1597 	}
1598 	qname = match_strdup(args);
1599 	if (!qname) {
1600 		ext4_msg(sb, KERN_ERR,
1601 			"Not enough memory for storing quotafile name");
1602 		return -1;
1603 	}
1604 	if (old_qname) {
1605 		if (strcmp(old_qname, qname) == 0)
1606 			ret = 1;
1607 		else
1608 			ext4_msg(sb, KERN_ERR,
1609 				 "%s quota file already specified",
1610 				 QTYPE2NAME(qtype));
1611 		goto errout;
1612 	}
1613 	if (strchr(qname, '/')) {
1614 		ext4_msg(sb, KERN_ERR,
1615 			"quotafile must be on filesystem root");
1616 		goto errout;
1617 	}
1618 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1619 	set_opt(sb, QUOTA);
1620 	return 1;
1621 errout:
1622 	kfree(qname);
1623 	return ret;
1624 }
1625 
1626 static int clear_qf_name(struct super_block *sb, int qtype)
1627 {
1628 
1629 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1630 	char *old_qname = get_qf_name(sb, sbi, qtype);
1631 
1632 	if (sb_any_quota_loaded(sb) && old_qname) {
1633 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1634 			" when quota turned on");
1635 		return -1;
1636 	}
1637 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1638 	synchronize_rcu();
1639 	kfree(old_qname);
1640 	return 1;
1641 }
1642 #endif
1643 
1644 #define MOPT_SET	0x0001
1645 #define MOPT_CLEAR	0x0002
1646 #define MOPT_NOSUPPORT	0x0004
1647 #define MOPT_EXPLICIT	0x0008
1648 #define MOPT_CLEAR_ERR	0x0010
1649 #define MOPT_GTE0	0x0020
1650 #ifdef CONFIG_QUOTA
1651 #define MOPT_Q		0
1652 #define MOPT_QFMT	0x0040
1653 #else
1654 #define MOPT_Q		MOPT_NOSUPPORT
1655 #define MOPT_QFMT	MOPT_NOSUPPORT
1656 #endif
1657 #define MOPT_DATAJ	0x0080
1658 #define MOPT_NO_EXT2	0x0100
1659 #define MOPT_NO_EXT3	0x0200
1660 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1661 #define MOPT_STRING	0x0400
1662 
1663 static const struct mount_opts {
1664 	int	token;
1665 	int	mount_opt;
1666 	int	flags;
1667 } ext4_mount_opts[] = {
1668 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1669 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1670 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1671 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1672 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1673 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1674 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1675 	 MOPT_EXT4_ONLY | MOPT_SET},
1676 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1677 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1678 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1679 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1680 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1681 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1682 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1683 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1684 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1685 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1686 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1687 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1688 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1689 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1690 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1691 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1692 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1693 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1694 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1695 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1696 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1697 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1698 	 MOPT_NO_EXT2},
1699 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1700 	 MOPT_NO_EXT2},
1701 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1702 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1703 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1704 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1705 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1706 	{Opt_commit, 0, MOPT_GTE0},
1707 	{Opt_max_batch_time, 0, MOPT_GTE0},
1708 	{Opt_min_batch_time, 0, MOPT_GTE0},
1709 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1710 	{Opt_init_itable, 0, MOPT_GTE0},
1711 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1712 	{Opt_stripe, 0, MOPT_GTE0},
1713 	{Opt_resuid, 0, MOPT_GTE0},
1714 	{Opt_resgid, 0, MOPT_GTE0},
1715 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1716 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1717 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1718 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1719 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1720 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1721 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1722 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1723 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1724 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1725 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1726 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1727 #else
1728 	{Opt_acl, 0, MOPT_NOSUPPORT},
1729 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1730 #endif
1731 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1732 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1733 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1734 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1735 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1736 							MOPT_SET | MOPT_Q},
1737 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1738 							MOPT_SET | MOPT_Q},
1739 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1740 							MOPT_SET | MOPT_Q},
1741 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1742 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1743 							MOPT_CLEAR | MOPT_Q},
1744 	{Opt_usrjquota, 0, MOPT_Q},
1745 	{Opt_grpjquota, 0, MOPT_Q},
1746 	{Opt_offusrjquota, 0, MOPT_Q},
1747 	{Opt_offgrpjquota, 0, MOPT_Q},
1748 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1749 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1750 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1751 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1752 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1753 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1754 	{Opt_err, 0, 0}
1755 };
1756 
1757 #ifdef CONFIG_UNICODE
1758 static const struct ext4_sb_encodings {
1759 	__u16 magic;
1760 	char *name;
1761 	char *version;
1762 } ext4_sb_encoding_map[] = {
1763 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
1764 };
1765 
1766 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
1767 				 const struct ext4_sb_encodings **encoding,
1768 				 __u16 *flags)
1769 {
1770 	__u16 magic = le16_to_cpu(es->s_encoding);
1771 	int i;
1772 
1773 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1774 		if (magic == ext4_sb_encoding_map[i].magic)
1775 			break;
1776 
1777 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
1778 		return -EINVAL;
1779 
1780 	*encoding = &ext4_sb_encoding_map[i];
1781 	*flags = le16_to_cpu(es->s_encoding_flags);
1782 
1783 	return 0;
1784 }
1785 #endif
1786 
1787 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1788 			    substring_t *args, unsigned long *journal_devnum,
1789 			    unsigned int *journal_ioprio, int is_remount)
1790 {
1791 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1792 	const struct mount_opts *m;
1793 	kuid_t uid;
1794 	kgid_t gid;
1795 	int arg = 0;
1796 
1797 #ifdef CONFIG_QUOTA
1798 	if (token == Opt_usrjquota)
1799 		return set_qf_name(sb, USRQUOTA, &args[0]);
1800 	else if (token == Opt_grpjquota)
1801 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1802 	else if (token == Opt_offusrjquota)
1803 		return clear_qf_name(sb, USRQUOTA);
1804 	else if (token == Opt_offgrpjquota)
1805 		return clear_qf_name(sb, GRPQUOTA);
1806 #endif
1807 	switch (token) {
1808 	case Opt_noacl:
1809 	case Opt_nouser_xattr:
1810 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1811 		break;
1812 	case Opt_sb:
1813 		return 1;	/* handled by get_sb_block() */
1814 	case Opt_removed:
1815 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1816 		return 1;
1817 	case Opt_abort:
1818 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1819 		return 1;
1820 	case Opt_i_version:
1821 		sb->s_flags |= SB_I_VERSION;
1822 		return 1;
1823 	case Opt_lazytime:
1824 		sb->s_flags |= SB_LAZYTIME;
1825 		return 1;
1826 	case Opt_nolazytime:
1827 		sb->s_flags &= ~SB_LAZYTIME;
1828 		return 1;
1829 	}
1830 
1831 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1832 		if (token == m->token)
1833 			break;
1834 
1835 	if (m->token == Opt_err) {
1836 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1837 			 "or missing value", opt);
1838 		return -1;
1839 	}
1840 
1841 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1842 		ext4_msg(sb, KERN_ERR,
1843 			 "Mount option \"%s\" incompatible with ext2", opt);
1844 		return -1;
1845 	}
1846 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1847 		ext4_msg(sb, KERN_ERR,
1848 			 "Mount option \"%s\" incompatible with ext3", opt);
1849 		return -1;
1850 	}
1851 
1852 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1853 		return -1;
1854 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1855 		return -1;
1856 	if (m->flags & MOPT_EXPLICIT) {
1857 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1858 			set_opt2(sb, EXPLICIT_DELALLOC);
1859 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1860 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1861 		} else
1862 			return -1;
1863 	}
1864 	if (m->flags & MOPT_CLEAR_ERR)
1865 		clear_opt(sb, ERRORS_MASK);
1866 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1867 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1868 			 "options when quota turned on");
1869 		return -1;
1870 	}
1871 
1872 	if (m->flags & MOPT_NOSUPPORT) {
1873 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1874 	} else if (token == Opt_commit) {
1875 		if (arg == 0)
1876 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1877 		sbi->s_commit_interval = HZ * arg;
1878 	} else if (token == Opt_debug_want_extra_isize) {
1879 		sbi->s_want_extra_isize = arg;
1880 	} else if (token == Opt_max_batch_time) {
1881 		sbi->s_max_batch_time = arg;
1882 	} else if (token == Opt_min_batch_time) {
1883 		sbi->s_min_batch_time = arg;
1884 	} else if (token == Opt_inode_readahead_blks) {
1885 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1886 			ext4_msg(sb, KERN_ERR,
1887 				 "EXT4-fs: inode_readahead_blks must be "
1888 				 "0 or a power of 2 smaller than 2^31");
1889 			return -1;
1890 		}
1891 		sbi->s_inode_readahead_blks = arg;
1892 	} else if (token == Opt_init_itable) {
1893 		set_opt(sb, INIT_INODE_TABLE);
1894 		if (!args->from)
1895 			arg = EXT4_DEF_LI_WAIT_MULT;
1896 		sbi->s_li_wait_mult = arg;
1897 	} else if (token == Opt_max_dir_size_kb) {
1898 		sbi->s_max_dir_size_kb = arg;
1899 	} else if (token == Opt_stripe) {
1900 		sbi->s_stripe = arg;
1901 	} else if (token == Opt_resuid) {
1902 		uid = make_kuid(current_user_ns(), arg);
1903 		if (!uid_valid(uid)) {
1904 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1905 			return -1;
1906 		}
1907 		sbi->s_resuid = uid;
1908 	} else if (token == Opt_resgid) {
1909 		gid = make_kgid(current_user_ns(), arg);
1910 		if (!gid_valid(gid)) {
1911 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1912 			return -1;
1913 		}
1914 		sbi->s_resgid = gid;
1915 	} else if (token == Opt_journal_dev) {
1916 		if (is_remount) {
1917 			ext4_msg(sb, KERN_ERR,
1918 				 "Cannot specify journal on remount");
1919 			return -1;
1920 		}
1921 		*journal_devnum = arg;
1922 	} else if (token == Opt_journal_path) {
1923 		char *journal_path;
1924 		struct inode *journal_inode;
1925 		struct path path;
1926 		int error;
1927 
1928 		if (is_remount) {
1929 			ext4_msg(sb, KERN_ERR,
1930 				 "Cannot specify journal on remount");
1931 			return -1;
1932 		}
1933 		journal_path = match_strdup(&args[0]);
1934 		if (!journal_path) {
1935 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1936 				"journal device string");
1937 			return -1;
1938 		}
1939 
1940 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1941 		if (error) {
1942 			ext4_msg(sb, KERN_ERR, "error: could not find "
1943 				"journal device path: error %d", error);
1944 			kfree(journal_path);
1945 			return -1;
1946 		}
1947 
1948 		journal_inode = d_inode(path.dentry);
1949 		if (!S_ISBLK(journal_inode->i_mode)) {
1950 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1951 				"is not a block device", journal_path);
1952 			path_put(&path);
1953 			kfree(journal_path);
1954 			return -1;
1955 		}
1956 
1957 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1958 		path_put(&path);
1959 		kfree(journal_path);
1960 	} else if (token == Opt_journal_ioprio) {
1961 		if (arg > 7) {
1962 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1963 				 " (must be 0-7)");
1964 			return -1;
1965 		}
1966 		*journal_ioprio =
1967 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1968 	} else if (token == Opt_test_dummy_encryption) {
1969 #ifdef CONFIG_FS_ENCRYPTION
1970 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1971 		ext4_msg(sb, KERN_WARNING,
1972 			 "Test dummy encryption mode enabled");
1973 #else
1974 		ext4_msg(sb, KERN_WARNING,
1975 			 "Test dummy encryption mount option ignored");
1976 #endif
1977 	} else if (m->flags & MOPT_DATAJ) {
1978 		if (is_remount) {
1979 			if (!sbi->s_journal)
1980 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1981 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1982 				ext4_msg(sb, KERN_ERR,
1983 					 "Cannot change data mode on remount");
1984 				return -1;
1985 			}
1986 		} else {
1987 			clear_opt(sb, DATA_FLAGS);
1988 			sbi->s_mount_opt |= m->mount_opt;
1989 		}
1990 #ifdef CONFIG_QUOTA
1991 	} else if (m->flags & MOPT_QFMT) {
1992 		if (sb_any_quota_loaded(sb) &&
1993 		    sbi->s_jquota_fmt != m->mount_opt) {
1994 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1995 				 "quota options when quota turned on");
1996 			return -1;
1997 		}
1998 		if (ext4_has_feature_quota(sb)) {
1999 			ext4_msg(sb, KERN_INFO,
2000 				 "Quota format mount options ignored "
2001 				 "when QUOTA feature is enabled");
2002 			return 1;
2003 		}
2004 		sbi->s_jquota_fmt = m->mount_opt;
2005 #endif
2006 	} else if (token == Opt_dax) {
2007 #ifdef CONFIG_FS_DAX
2008 		ext4_msg(sb, KERN_WARNING,
2009 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2010 		sbi->s_mount_opt |= m->mount_opt;
2011 #else
2012 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2013 		return -1;
2014 #endif
2015 	} else if (token == Opt_data_err_abort) {
2016 		sbi->s_mount_opt |= m->mount_opt;
2017 	} else if (token == Opt_data_err_ignore) {
2018 		sbi->s_mount_opt &= ~m->mount_opt;
2019 	} else {
2020 		if (!args->from)
2021 			arg = 1;
2022 		if (m->flags & MOPT_CLEAR)
2023 			arg = !arg;
2024 		else if (unlikely(!(m->flags & MOPT_SET))) {
2025 			ext4_msg(sb, KERN_WARNING,
2026 				 "buggy handling of option %s", opt);
2027 			WARN_ON(1);
2028 			return -1;
2029 		}
2030 		if (arg != 0)
2031 			sbi->s_mount_opt |= m->mount_opt;
2032 		else
2033 			sbi->s_mount_opt &= ~m->mount_opt;
2034 	}
2035 	return 1;
2036 }
2037 
2038 static int parse_options(char *options, struct super_block *sb,
2039 			 unsigned long *journal_devnum,
2040 			 unsigned int *journal_ioprio,
2041 			 int is_remount)
2042 {
2043 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2044 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2045 	substring_t args[MAX_OPT_ARGS];
2046 	int token;
2047 
2048 	if (!options)
2049 		return 1;
2050 
2051 	while ((p = strsep(&options, ",")) != NULL) {
2052 		if (!*p)
2053 			continue;
2054 		/*
2055 		 * Initialize args struct so we know whether arg was
2056 		 * found; some options take optional arguments.
2057 		 */
2058 		args[0].to = args[0].from = NULL;
2059 		token = match_token(p, tokens, args);
2060 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2061 				     journal_ioprio, is_remount) < 0)
2062 			return 0;
2063 	}
2064 #ifdef CONFIG_QUOTA
2065 	/*
2066 	 * We do the test below only for project quotas. 'usrquota' and
2067 	 * 'grpquota' mount options are allowed even without quota feature
2068 	 * to support legacy quotas in quota files.
2069 	 */
2070 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2071 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2072 			 "Cannot enable project quota enforcement.");
2073 		return 0;
2074 	}
2075 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2076 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2077 	if (usr_qf_name || grp_qf_name) {
2078 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2079 			clear_opt(sb, USRQUOTA);
2080 
2081 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2082 			clear_opt(sb, GRPQUOTA);
2083 
2084 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2085 			ext4_msg(sb, KERN_ERR, "old and new quota "
2086 					"format mixing");
2087 			return 0;
2088 		}
2089 
2090 		if (!sbi->s_jquota_fmt) {
2091 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2092 					"not specified");
2093 			return 0;
2094 		}
2095 	}
2096 #endif
2097 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2098 		int blocksize =
2099 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2100 
2101 		if (blocksize < PAGE_SIZE) {
2102 			ext4_msg(sb, KERN_ERR, "can't mount with "
2103 				 "dioread_nolock if block size != PAGE_SIZE");
2104 			return 0;
2105 		}
2106 	}
2107 	return 1;
2108 }
2109 
2110 static inline void ext4_show_quota_options(struct seq_file *seq,
2111 					   struct super_block *sb)
2112 {
2113 #if defined(CONFIG_QUOTA)
2114 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2115 	char *usr_qf_name, *grp_qf_name;
2116 
2117 	if (sbi->s_jquota_fmt) {
2118 		char *fmtname = "";
2119 
2120 		switch (sbi->s_jquota_fmt) {
2121 		case QFMT_VFS_OLD:
2122 			fmtname = "vfsold";
2123 			break;
2124 		case QFMT_VFS_V0:
2125 			fmtname = "vfsv0";
2126 			break;
2127 		case QFMT_VFS_V1:
2128 			fmtname = "vfsv1";
2129 			break;
2130 		}
2131 		seq_printf(seq, ",jqfmt=%s", fmtname);
2132 	}
2133 
2134 	rcu_read_lock();
2135 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2136 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2137 	if (usr_qf_name)
2138 		seq_show_option(seq, "usrjquota", usr_qf_name);
2139 	if (grp_qf_name)
2140 		seq_show_option(seq, "grpjquota", grp_qf_name);
2141 	rcu_read_unlock();
2142 #endif
2143 }
2144 
2145 static const char *token2str(int token)
2146 {
2147 	const struct match_token *t;
2148 
2149 	for (t = tokens; t->token != Opt_err; t++)
2150 		if (t->token == token && !strchr(t->pattern, '='))
2151 			break;
2152 	return t->pattern;
2153 }
2154 
2155 /*
2156  * Show an option if
2157  *  - it's set to a non-default value OR
2158  *  - if the per-sb default is different from the global default
2159  */
2160 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2161 			      int nodefs)
2162 {
2163 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2164 	struct ext4_super_block *es = sbi->s_es;
2165 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2166 	const struct mount_opts *m;
2167 	char sep = nodefs ? '\n' : ',';
2168 
2169 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2170 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2171 
2172 	if (sbi->s_sb_block != 1)
2173 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2174 
2175 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2176 		int want_set = m->flags & MOPT_SET;
2177 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2178 		    (m->flags & MOPT_CLEAR_ERR))
2179 			continue;
2180 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2181 			continue; /* skip if same as the default */
2182 		if ((want_set &&
2183 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2184 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2185 			continue; /* select Opt_noFoo vs Opt_Foo */
2186 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2187 	}
2188 
2189 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2190 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2191 		SEQ_OPTS_PRINT("resuid=%u",
2192 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2193 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2194 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2195 		SEQ_OPTS_PRINT("resgid=%u",
2196 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2197 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2198 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2199 		SEQ_OPTS_PUTS("errors=remount-ro");
2200 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2201 		SEQ_OPTS_PUTS("errors=continue");
2202 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2203 		SEQ_OPTS_PUTS("errors=panic");
2204 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2205 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2206 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2207 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2208 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2209 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2210 	if (sb->s_flags & SB_I_VERSION)
2211 		SEQ_OPTS_PUTS("i_version");
2212 	if (nodefs || sbi->s_stripe)
2213 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2214 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2215 			(sbi->s_mount_opt ^ def_mount_opt)) {
2216 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2217 			SEQ_OPTS_PUTS("data=journal");
2218 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2219 			SEQ_OPTS_PUTS("data=ordered");
2220 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2221 			SEQ_OPTS_PUTS("data=writeback");
2222 	}
2223 	if (nodefs ||
2224 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2225 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2226 			       sbi->s_inode_readahead_blks);
2227 
2228 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2229 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2230 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2231 	if (nodefs || sbi->s_max_dir_size_kb)
2232 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2233 	if (test_opt(sb, DATA_ERR_ABORT))
2234 		SEQ_OPTS_PUTS("data_err=abort");
2235 	if (DUMMY_ENCRYPTION_ENABLED(sbi))
2236 		SEQ_OPTS_PUTS("test_dummy_encryption");
2237 
2238 	ext4_show_quota_options(seq, sb);
2239 	return 0;
2240 }
2241 
2242 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2243 {
2244 	return _ext4_show_options(seq, root->d_sb, 0);
2245 }
2246 
2247 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2248 {
2249 	struct super_block *sb = seq->private;
2250 	int rc;
2251 
2252 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2253 	rc = _ext4_show_options(seq, sb, 1);
2254 	seq_puts(seq, "\n");
2255 	return rc;
2256 }
2257 
2258 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2259 			    int read_only)
2260 {
2261 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2262 	int err = 0;
2263 
2264 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2265 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2266 			 "forcing read-only mode");
2267 		err = -EROFS;
2268 	}
2269 	if (read_only)
2270 		goto done;
2271 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2272 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2273 			 "running e2fsck is recommended");
2274 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2275 		ext4_msg(sb, KERN_WARNING,
2276 			 "warning: mounting fs with errors, "
2277 			 "running e2fsck is recommended");
2278 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2279 		 le16_to_cpu(es->s_mnt_count) >=
2280 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2281 		ext4_msg(sb, KERN_WARNING,
2282 			 "warning: maximal mount count reached, "
2283 			 "running e2fsck is recommended");
2284 	else if (le32_to_cpu(es->s_checkinterval) &&
2285 		 (ext4_get_tstamp(es, s_lastcheck) +
2286 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2287 		ext4_msg(sb, KERN_WARNING,
2288 			 "warning: checktime reached, "
2289 			 "running e2fsck is recommended");
2290 	if (!sbi->s_journal)
2291 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2292 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2293 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2294 	le16_add_cpu(&es->s_mnt_count, 1);
2295 	ext4_update_tstamp(es, s_mtime);
2296 	if (sbi->s_journal)
2297 		ext4_set_feature_journal_needs_recovery(sb);
2298 
2299 	err = ext4_commit_super(sb, 1);
2300 done:
2301 	if (test_opt(sb, DEBUG))
2302 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2303 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2304 			sb->s_blocksize,
2305 			sbi->s_groups_count,
2306 			EXT4_BLOCKS_PER_GROUP(sb),
2307 			EXT4_INODES_PER_GROUP(sb),
2308 			sbi->s_mount_opt, sbi->s_mount_opt2);
2309 
2310 	cleancache_init_fs(sb);
2311 	return err;
2312 }
2313 
2314 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2315 {
2316 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2317 	struct flex_groups *new_groups;
2318 	int size;
2319 
2320 	if (!sbi->s_log_groups_per_flex)
2321 		return 0;
2322 
2323 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2324 	if (size <= sbi->s_flex_groups_allocated)
2325 		return 0;
2326 
2327 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2328 	new_groups = kvzalloc(size, GFP_KERNEL);
2329 	if (!new_groups) {
2330 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2331 			 size / (int) sizeof(struct flex_groups));
2332 		return -ENOMEM;
2333 	}
2334 
2335 	if (sbi->s_flex_groups) {
2336 		memcpy(new_groups, sbi->s_flex_groups,
2337 		       (sbi->s_flex_groups_allocated *
2338 			sizeof(struct flex_groups)));
2339 		kvfree(sbi->s_flex_groups);
2340 	}
2341 	sbi->s_flex_groups = new_groups;
2342 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2343 	return 0;
2344 }
2345 
2346 static int ext4_fill_flex_info(struct super_block *sb)
2347 {
2348 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2349 	struct ext4_group_desc *gdp = NULL;
2350 	ext4_group_t flex_group;
2351 	int i, err;
2352 
2353 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2354 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2355 		sbi->s_log_groups_per_flex = 0;
2356 		return 1;
2357 	}
2358 
2359 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2360 	if (err)
2361 		goto failed;
2362 
2363 	for (i = 0; i < sbi->s_groups_count; i++) {
2364 		gdp = ext4_get_group_desc(sb, i, NULL);
2365 
2366 		flex_group = ext4_flex_group(sbi, i);
2367 		atomic_add(ext4_free_inodes_count(sb, gdp),
2368 			   &sbi->s_flex_groups[flex_group].free_inodes);
2369 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2370 			     &sbi->s_flex_groups[flex_group].free_clusters);
2371 		atomic_add(ext4_used_dirs_count(sb, gdp),
2372 			   &sbi->s_flex_groups[flex_group].used_dirs);
2373 	}
2374 
2375 	return 1;
2376 failed:
2377 	return 0;
2378 }
2379 
2380 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2381 				   struct ext4_group_desc *gdp)
2382 {
2383 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2384 	__u16 crc = 0;
2385 	__le32 le_group = cpu_to_le32(block_group);
2386 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2387 
2388 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2389 		/* Use new metadata_csum algorithm */
2390 		__u32 csum32;
2391 		__u16 dummy_csum = 0;
2392 
2393 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2394 				     sizeof(le_group));
2395 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2396 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2397 				     sizeof(dummy_csum));
2398 		offset += sizeof(dummy_csum);
2399 		if (offset < sbi->s_desc_size)
2400 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2401 					     sbi->s_desc_size - offset);
2402 
2403 		crc = csum32 & 0xFFFF;
2404 		goto out;
2405 	}
2406 
2407 	/* old crc16 code */
2408 	if (!ext4_has_feature_gdt_csum(sb))
2409 		return 0;
2410 
2411 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2412 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2413 	crc = crc16(crc, (__u8 *)gdp, offset);
2414 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2415 	/* for checksum of struct ext4_group_desc do the rest...*/
2416 	if (ext4_has_feature_64bit(sb) &&
2417 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2418 		crc = crc16(crc, (__u8 *)gdp + offset,
2419 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2420 				offset);
2421 
2422 out:
2423 	return cpu_to_le16(crc);
2424 }
2425 
2426 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2427 				struct ext4_group_desc *gdp)
2428 {
2429 	if (ext4_has_group_desc_csum(sb) &&
2430 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2431 		return 0;
2432 
2433 	return 1;
2434 }
2435 
2436 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2437 			      struct ext4_group_desc *gdp)
2438 {
2439 	if (!ext4_has_group_desc_csum(sb))
2440 		return;
2441 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2442 }
2443 
2444 /* Called at mount-time, super-block is locked */
2445 static int ext4_check_descriptors(struct super_block *sb,
2446 				  ext4_fsblk_t sb_block,
2447 				  ext4_group_t *first_not_zeroed)
2448 {
2449 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2450 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2451 	ext4_fsblk_t last_block;
2452 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2453 	ext4_fsblk_t block_bitmap;
2454 	ext4_fsblk_t inode_bitmap;
2455 	ext4_fsblk_t inode_table;
2456 	int flexbg_flag = 0;
2457 	ext4_group_t i, grp = sbi->s_groups_count;
2458 
2459 	if (ext4_has_feature_flex_bg(sb))
2460 		flexbg_flag = 1;
2461 
2462 	ext4_debug("Checking group descriptors");
2463 
2464 	for (i = 0; i < sbi->s_groups_count; i++) {
2465 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2466 
2467 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2468 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2469 		else
2470 			last_block = first_block +
2471 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2472 
2473 		if ((grp == sbi->s_groups_count) &&
2474 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2475 			grp = i;
2476 
2477 		block_bitmap = ext4_block_bitmap(sb, gdp);
2478 		if (block_bitmap == sb_block) {
2479 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2480 				 "Block bitmap for group %u overlaps "
2481 				 "superblock", i);
2482 			if (!sb_rdonly(sb))
2483 				return 0;
2484 		}
2485 		if (block_bitmap >= sb_block + 1 &&
2486 		    block_bitmap <= last_bg_block) {
2487 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2488 				 "Block bitmap for group %u overlaps "
2489 				 "block group descriptors", i);
2490 			if (!sb_rdonly(sb))
2491 				return 0;
2492 		}
2493 		if (block_bitmap < first_block || block_bitmap > last_block) {
2494 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2495 			       "Block bitmap for group %u not in group "
2496 			       "(block %llu)!", i, block_bitmap);
2497 			return 0;
2498 		}
2499 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2500 		if (inode_bitmap == sb_block) {
2501 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2502 				 "Inode bitmap for group %u overlaps "
2503 				 "superblock", i);
2504 			if (!sb_rdonly(sb))
2505 				return 0;
2506 		}
2507 		if (inode_bitmap >= sb_block + 1 &&
2508 		    inode_bitmap <= last_bg_block) {
2509 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2510 				 "Inode bitmap for group %u overlaps "
2511 				 "block group descriptors", i);
2512 			if (!sb_rdonly(sb))
2513 				return 0;
2514 		}
2515 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2516 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2517 			       "Inode bitmap for group %u not in group "
2518 			       "(block %llu)!", i, inode_bitmap);
2519 			return 0;
2520 		}
2521 		inode_table = ext4_inode_table(sb, gdp);
2522 		if (inode_table == sb_block) {
2523 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2524 				 "Inode table for group %u overlaps "
2525 				 "superblock", i);
2526 			if (!sb_rdonly(sb))
2527 				return 0;
2528 		}
2529 		if (inode_table >= sb_block + 1 &&
2530 		    inode_table <= last_bg_block) {
2531 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2532 				 "Inode table for group %u overlaps "
2533 				 "block group descriptors", i);
2534 			if (!sb_rdonly(sb))
2535 				return 0;
2536 		}
2537 		if (inode_table < first_block ||
2538 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2539 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2540 			       "Inode table for group %u not in group "
2541 			       "(block %llu)!", i, inode_table);
2542 			return 0;
2543 		}
2544 		ext4_lock_group(sb, i);
2545 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2546 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2547 				 "Checksum for group %u failed (%u!=%u)",
2548 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2549 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2550 			if (!sb_rdonly(sb)) {
2551 				ext4_unlock_group(sb, i);
2552 				return 0;
2553 			}
2554 		}
2555 		ext4_unlock_group(sb, i);
2556 		if (!flexbg_flag)
2557 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2558 	}
2559 	if (NULL != first_not_zeroed)
2560 		*first_not_zeroed = grp;
2561 	return 1;
2562 }
2563 
2564 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2565  * the superblock) which were deleted from all directories, but held open by
2566  * a process at the time of a crash.  We walk the list and try to delete these
2567  * inodes at recovery time (only with a read-write filesystem).
2568  *
2569  * In order to keep the orphan inode chain consistent during traversal (in
2570  * case of crash during recovery), we link each inode into the superblock
2571  * orphan list_head and handle it the same way as an inode deletion during
2572  * normal operation (which journals the operations for us).
2573  *
2574  * We only do an iget() and an iput() on each inode, which is very safe if we
2575  * accidentally point at an in-use or already deleted inode.  The worst that
2576  * can happen in this case is that we get a "bit already cleared" message from
2577  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2578  * e2fsck was run on this filesystem, and it must have already done the orphan
2579  * inode cleanup for us, so we can safely abort without any further action.
2580  */
2581 static void ext4_orphan_cleanup(struct super_block *sb,
2582 				struct ext4_super_block *es)
2583 {
2584 	unsigned int s_flags = sb->s_flags;
2585 	int ret, nr_orphans = 0, nr_truncates = 0;
2586 #ifdef CONFIG_QUOTA
2587 	int quota_update = 0;
2588 	int i;
2589 #endif
2590 	if (!es->s_last_orphan) {
2591 		jbd_debug(4, "no orphan inodes to clean up\n");
2592 		return;
2593 	}
2594 
2595 	if (bdev_read_only(sb->s_bdev)) {
2596 		ext4_msg(sb, KERN_ERR, "write access "
2597 			"unavailable, skipping orphan cleanup");
2598 		return;
2599 	}
2600 
2601 	/* Check if feature set would not allow a r/w mount */
2602 	if (!ext4_feature_set_ok(sb, 0)) {
2603 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2604 			 "unknown ROCOMPAT features");
2605 		return;
2606 	}
2607 
2608 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2609 		/* don't clear list on RO mount w/ errors */
2610 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2611 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2612 				  "clearing orphan list.\n");
2613 			es->s_last_orphan = 0;
2614 		}
2615 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2616 		return;
2617 	}
2618 
2619 	if (s_flags & SB_RDONLY) {
2620 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2621 		sb->s_flags &= ~SB_RDONLY;
2622 	}
2623 #ifdef CONFIG_QUOTA
2624 	/* Needed for iput() to work correctly and not trash data */
2625 	sb->s_flags |= SB_ACTIVE;
2626 
2627 	/*
2628 	 * Turn on quotas which were not enabled for read-only mounts if
2629 	 * filesystem has quota feature, so that they are updated correctly.
2630 	 */
2631 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2632 		int ret = ext4_enable_quotas(sb);
2633 
2634 		if (!ret)
2635 			quota_update = 1;
2636 		else
2637 			ext4_msg(sb, KERN_ERR,
2638 				"Cannot turn on quotas: error %d", ret);
2639 	}
2640 
2641 	/* Turn on journaled quotas used for old sytle */
2642 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2643 		if (EXT4_SB(sb)->s_qf_names[i]) {
2644 			int ret = ext4_quota_on_mount(sb, i);
2645 
2646 			if (!ret)
2647 				quota_update = 1;
2648 			else
2649 				ext4_msg(sb, KERN_ERR,
2650 					"Cannot turn on journaled "
2651 					"quota: type %d: error %d", i, ret);
2652 		}
2653 	}
2654 #endif
2655 
2656 	while (es->s_last_orphan) {
2657 		struct inode *inode;
2658 
2659 		/*
2660 		 * We may have encountered an error during cleanup; if
2661 		 * so, skip the rest.
2662 		 */
2663 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2664 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2665 			es->s_last_orphan = 0;
2666 			break;
2667 		}
2668 
2669 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2670 		if (IS_ERR(inode)) {
2671 			es->s_last_orphan = 0;
2672 			break;
2673 		}
2674 
2675 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2676 		dquot_initialize(inode);
2677 		if (inode->i_nlink) {
2678 			if (test_opt(sb, DEBUG))
2679 				ext4_msg(sb, KERN_DEBUG,
2680 					"%s: truncating inode %lu to %lld bytes",
2681 					__func__, inode->i_ino, inode->i_size);
2682 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2683 				  inode->i_ino, inode->i_size);
2684 			inode_lock(inode);
2685 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2686 			ret = ext4_truncate(inode);
2687 			if (ret)
2688 				ext4_std_error(inode->i_sb, ret);
2689 			inode_unlock(inode);
2690 			nr_truncates++;
2691 		} else {
2692 			if (test_opt(sb, DEBUG))
2693 				ext4_msg(sb, KERN_DEBUG,
2694 					"%s: deleting unreferenced inode %lu",
2695 					__func__, inode->i_ino);
2696 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2697 				  inode->i_ino);
2698 			nr_orphans++;
2699 		}
2700 		iput(inode);  /* The delete magic happens here! */
2701 	}
2702 
2703 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2704 
2705 	if (nr_orphans)
2706 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2707 		       PLURAL(nr_orphans));
2708 	if (nr_truncates)
2709 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2710 		       PLURAL(nr_truncates));
2711 #ifdef CONFIG_QUOTA
2712 	/* Turn off quotas if they were enabled for orphan cleanup */
2713 	if (quota_update) {
2714 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2715 			if (sb_dqopt(sb)->files[i])
2716 				dquot_quota_off(sb, i);
2717 		}
2718 	}
2719 #endif
2720 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2721 }
2722 
2723 /*
2724  * Maximal extent format file size.
2725  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2726  * extent format containers, within a sector_t, and within i_blocks
2727  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2728  * so that won't be a limiting factor.
2729  *
2730  * However there is other limiting factor. We do store extents in the form
2731  * of starting block and length, hence the resulting length of the extent
2732  * covering maximum file size must fit into on-disk format containers as
2733  * well. Given that length is always by 1 unit bigger than max unit (because
2734  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2735  *
2736  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2737  */
2738 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2739 {
2740 	loff_t res;
2741 	loff_t upper_limit = MAX_LFS_FILESIZE;
2742 
2743 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
2744 
2745 	if (!has_huge_files) {
2746 		upper_limit = (1LL << 32) - 1;
2747 
2748 		/* total blocks in file system block size */
2749 		upper_limit >>= (blkbits - 9);
2750 		upper_limit <<= blkbits;
2751 	}
2752 
2753 	/*
2754 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2755 	 * by one fs block, so ee_len can cover the extent of maximum file
2756 	 * size
2757 	 */
2758 	res = (1LL << 32) - 1;
2759 	res <<= blkbits;
2760 
2761 	/* Sanity check against vm- & vfs- imposed limits */
2762 	if (res > upper_limit)
2763 		res = upper_limit;
2764 
2765 	return res;
2766 }
2767 
2768 /*
2769  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2770  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2771  * We need to be 1 filesystem block less than the 2^48 sector limit.
2772  */
2773 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2774 {
2775 	loff_t res = EXT4_NDIR_BLOCKS;
2776 	int meta_blocks;
2777 	loff_t upper_limit;
2778 	/* This is calculated to be the largest file size for a dense, block
2779 	 * mapped file such that the file's total number of 512-byte sectors,
2780 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2781 	 *
2782 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2783 	 * number of 512-byte sectors of the file.
2784 	 */
2785 
2786 	if (!has_huge_files) {
2787 		/*
2788 		 * !has_huge_files or implies that the inode i_block field
2789 		 * represents total file blocks in 2^32 512-byte sectors ==
2790 		 * size of vfs inode i_blocks * 8
2791 		 */
2792 		upper_limit = (1LL << 32) - 1;
2793 
2794 		/* total blocks in file system block size */
2795 		upper_limit >>= (bits - 9);
2796 
2797 	} else {
2798 		/*
2799 		 * We use 48 bit ext4_inode i_blocks
2800 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2801 		 * represent total number of blocks in
2802 		 * file system block size
2803 		 */
2804 		upper_limit = (1LL << 48) - 1;
2805 
2806 	}
2807 
2808 	/* indirect blocks */
2809 	meta_blocks = 1;
2810 	/* double indirect blocks */
2811 	meta_blocks += 1 + (1LL << (bits-2));
2812 	/* tripple indirect blocks */
2813 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2814 
2815 	upper_limit -= meta_blocks;
2816 	upper_limit <<= bits;
2817 
2818 	res += 1LL << (bits-2);
2819 	res += 1LL << (2*(bits-2));
2820 	res += 1LL << (3*(bits-2));
2821 	res <<= bits;
2822 	if (res > upper_limit)
2823 		res = upper_limit;
2824 
2825 	if (res > MAX_LFS_FILESIZE)
2826 		res = MAX_LFS_FILESIZE;
2827 
2828 	return res;
2829 }
2830 
2831 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2832 				   ext4_fsblk_t logical_sb_block, int nr)
2833 {
2834 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2835 	ext4_group_t bg, first_meta_bg;
2836 	int has_super = 0;
2837 
2838 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2839 
2840 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2841 		return logical_sb_block + nr + 1;
2842 	bg = sbi->s_desc_per_block * nr;
2843 	if (ext4_bg_has_super(sb, bg))
2844 		has_super = 1;
2845 
2846 	/*
2847 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2848 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2849 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2850 	 * compensate.
2851 	 */
2852 	if (sb->s_blocksize == 1024 && nr == 0 &&
2853 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2854 		has_super++;
2855 
2856 	return (has_super + ext4_group_first_block_no(sb, bg));
2857 }
2858 
2859 /**
2860  * ext4_get_stripe_size: Get the stripe size.
2861  * @sbi: In memory super block info
2862  *
2863  * If we have specified it via mount option, then
2864  * use the mount option value. If the value specified at mount time is
2865  * greater than the blocks per group use the super block value.
2866  * If the super block value is greater than blocks per group return 0.
2867  * Allocator needs it be less than blocks per group.
2868  *
2869  */
2870 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2871 {
2872 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2873 	unsigned long stripe_width =
2874 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2875 	int ret;
2876 
2877 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2878 		ret = sbi->s_stripe;
2879 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2880 		ret = stripe_width;
2881 	else if (stride && stride <= sbi->s_blocks_per_group)
2882 		ret = stride;
2883 	else
2884 		ret = 0;
2885 
2886 	/*
2887 	 * If the stripe width is 1, this makes no sense and
2888 	 * we set it to 0 to turn off stripe handling code.
2889 	 */
2890 	if (ret <= 1)
2891 		ret = 0;
2892 
2893 	return ret;
2894 }
2895 
2896 /*
2897  * Check whether this filesystem can be mounted based on
2898  * the features present and the RDONLY/RDWR mount requested.
2899  * Returns 1 if this filesystem can be mounted as requested,
2900  * 0 if it cannot be.
2901  */
2902 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2903 {
2904 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2905 		ext4_msg(sb, KERN_ERR,
2906 			"Couldn't mount because of "
2907 			"unsupported optional features (%x)",
2908 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2909 			~EXT4_FEATURE_INCOMPAT_SUPP));
2910 		return 0;
2911 	}
2912 
2913 #ifndef CONFIG_UNICODE
2914 	if (ext4_has_feature_casefold(sb)) {
2915 		ext4_msg(sb, KERN_ERR,
2916 			 "Filesystem with casefold feature cannot be "
2917 			 "mounted without CONFIG_UNICODE");
2918 		return 0;
2919 	}
2920 #endif
2921 
2922 	if (readonly)
2923 		return 1;
2924 
2925 	if (ext4_has_feature_readonly(sb)) {
2926 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2927 		sb->s_flags |= SB_RDONLY;
2928 		return 1;
2929 	}
2930 
2931 	/* Check that feature set is OK for a read-write mount */
2932 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2933 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2934 			 "unsupported optional features (%x)",
2935 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2936 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2937 		return 0;
2938 	}
2939 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2940 		ext4_msg(sb, KERN_ERR,
2941 			 "Can't support bigalloc feature without "
2942 			 "extents feature\n");
2943 		return 0;
2944 	}
2945 
2946 #ifndef CONFIG_QUOTA
2947 	if (ext4_has_feature_quota(sb) && !readonly) {
2948 		ext4_msg(sb, KERN_ERR,
2949 			 "Filesystem with quota feature cannot be mounted RDWR "
2950 			 "without CONFIG_QUOTA");
2951 		return 0;
2952 	}
2953 	if (ext4_has_feature_project(sb) && !readonly) {
2954 		ext4_msg(sb, KERN_ERR,
2955 			 "Filesystem with project quota feature cannot be mounted RDWR "
2956 			 "without CONFIG_QUOTA");
2957 		return 0;
2958 	}
2959 #endif  /* CONFIG_QUOTA */
2960 	return 1;
2961 }
2962 
2963 /*
2964  * This function is called once a day if we have errors logged
2965  * on the file system
2966  */
2967 static void print_daily_error_info(struct timer_list *t)
2968 {
2969 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2970 	struct super_block *sb = sbi->s_sb;
2971 	struct ext4_super_block *es = sbi->s_es;
2972 
2973 	if (es->s_error_count)
2974 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2975 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2976 			 le32_to_cpu(es->s_error_count));
2977 	if (es->s_first_error_time) {
2978 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
2979 		       sb->s_id,
2980 		       ext4_get_tstamp(es, s_first_error_time),
2981 		       (int) sizeof(es->s_first_error_func),
2982 		       es->s_first_error_func,
2983 		       le32_to_cpu(es->s_first_error_line));
2984 		if (es->s_first_error_ino)
2985 			printk(KERN_CONT ": inode %u",
2986 			       le32_to_cpu(es->s_first_error_ino));
2987 		if (es->s_first_error_block)
2988 			printk(KERN_CONT ": block %llu", (unsigned long long)
2989 			       le64_to_cpu(es->s_first_error_block));
2990 		printk(KERN_CONT "\n");
2991 	}
2992 	if (es->s_last_error_time) {
2993 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
2994 		       sb->s_id,
2995 		       ext4_get_tstamp(es, s_last_error_time),
2996 		       (int) sizeof(es->s_last_error_func),
2997 		       es->s_last_error_func,
2998 		       le32_to_cpu(es->s_last_error_line));
2999 		if (es->s_last_error_ino)
3000 			printk(KERN_CONT ": inode %u",
3001 			       le32_to_cpu(es->s_last_error_ino));
3002 		if (es->s_last_error_block)
3003 			printk(KERN_CONT ": block %llu", (unsigned long long)
3004 			       le64_to_cpu(es->s_last_error_block));
3005 		printk(KERN_CONT "\n");
3006 	}
3007 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3008 }
3009 
3010 /* Find next suitable group and run ext4_init_inode_table */
3011 static int ext4_run_li_request(struct ext4_li_request *elr)
3012 {
3013 	struct ext4_group_desc *gdp = NULL;
3014 	ext4_group_t group, ngroups;
3015 	struct super_block *sb;
3016 	unsigned long timeout = 0;
3017 	int ret = 0;
3018 
3019 	sb = elr->lr_super;
3020 	ngroups = EXT4_SB(sb)->s_groups_count;
3021 
3022 	for (group = elr->lr_next_group; group < ngroups; group++) {
3023 		gdp = ext4_get_group_desc(sb, group, NULL);
3024 		if (!gdp) {
3025 			ret = 1;
3026 			break;
3027 		}
3028 
3029 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3030 			break;
3031 	}
3032 
3033 	if (group >= ngroups)
3034 		ret = 1;
3035 
3036 	if (!ret) {
3037 		timeout = jiffies;
3038 		ret = ext4_init_inode_table(sb, group,
3039 					    elr->lr_timeout ? 0 : 1);
3040 		if (elr->lr_timeout == 0) {
3041 			timeout = (jiffies - timeout) *
3042 				  elr->lr_sbi->s_li_wait_mult;
3043 			elr->lr_timeout = timeout;
3044 		}
3045 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3046 		elr->lr_next_group = group + 1;
3047 	}
3048 	return ret;
3049 }
3050 
3051 /*
3052  * Remove lr_request from the list_request and free the
3053  * request structure. Should be called with li_list_mtx held
3054  */
3055 static void ext4_remove_li_request(struct ext4_li_request *elr)
3056 {
3057 	struct ext4_sb_info *sbi;
3058 
3059 	if (!elr)
3060 		return;
3061 
3062 	sbi = elr->lr_sbi;
3063 
3064 	list_del(&elr->lr_request);
3065 	sbi->s_li_request = NULL;
3066 	kfree(elr);
3067 }
3068 
3069 static void ext4_unregister_li_request(struct super_block *sb)
3070 {
3071 	mutex_lock(&ext4_li_mtx);
3072 	if (!ext4_li_info) {
3073 		mutex_unlock(&ext4_li_mtx);
3074 		return;
3075 	}
3076 
3077 	mutex_lock(&ext4_li_info->li_list_mtx);
3078 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3079 	mutex_unlock(&ext4_li_info->li_list_mtx);
3080 	mutex_unlock(&ext4_li_mtx);
3081 }
3082 
3083 static struct task_struct *ext4_lazyinit_task;
3084 
3085 /*
3086  * This is the function where ext4lazyinit thread lives. It walks
3087  * through the request list searching for next scheduled filesystem.
3088  * When such a fs is found, run the lazy initialization request
3089  * (ext4_rn_li_request) and keep track of the time spend in this
3090  * function. Based on that time we compute next schedule time of
3091  * the request. When walking through the list is complete, compute
3092  * next waking time and put itself into sleep.
3093  */
3094 static int ext4_lazyinit_thread(void *arg)
3095 {
3096 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3097 	struct list_head *pos, *n;
3098 	struct ext4_li_request *elr;
3099 	unsigned long next_wakeup, cur;
3100 
3101 	BUG_ON(NULL == eli);
3102 
3103 cont_thread:
3104 	while (true) {
3105 		next_wakeup = MAX_JIFFY_OFFSET;
3106 
3107 		mutex_lock(&eli->li_list_mtx);
3108 		if (list_empty(&eli->li_request_list)) {
3109 			mutex_unlock(&eli->li_list_mtx);
3110 			goto exit_thread;
3111 		}
3112 		list_for_each_safe(pos, n, &eli->li_request_list) {
3113 			int err = 0;
3114 			int progress = 0;
3115 			elr = list_entry(pos, struct ext4_li_request,
3116 					 lr_request);
3117 
3118 			if (time_before(jiffies, elr->lr_next_sched)) {
3119 				if (time_before(elr->lr_next_sched, next_wakeup))
3120 					next_wakeup = elr->lr_next_sched;
3121 				continue;
3122 			}
3123 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3124 				if (sb_start_write_trylock(elr->lr_super)) {
3125 					progress = 1;
3126 					/*
3127 					 * We hold sb->s_umount, sb can not
3128 					 * be removed from the list, it is
3129 					 * now safe to drop li_list_mtx
3130 					 */
3131 					mutex_unlock(&eli->li_list_mtx);
3132 					err = ext4_run_li_request(elr);
3133 					sb_end_write(elr->lr_super);
3134 					mutex_lock(&eli->li_list_mtx);
3135 					n = pos->next;
3136 				}
3137 				up_read((&elr->lr_super->s_umount));
3138 			}
3139 			/* error, remove the lazy_init job */
3140 			if (err) {
3141 				ext4_remove_li_request(elr);
3142 				continue;
3143 			}
3144 			if (!progress) {
3145 				elr->lr_next_sched = jiffies +
3146 					(prandom_u32()
3147 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3148 			}
3149 			if (time_before(elr->lr_next_sched, next_wakeup))
3150 				next_wakeup = elr->lr_next_sched;
3151 		}
3152 		mutex_unlock(&eli->li_list_mtx);
3153 
3154 		try_to_freeze();
3155 
3156 		cur = jiffies;
3157 		if ((time_after_eq(cur, next_wakeup)) ||
3158 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3159 			cond_resched();
3160 			continue;
3161 		}
3162 
3163 		schedule_timeout_interruptible(next_wakeup - cur);
3164 
3165 		if (kthread_should_stop()) {
3166 			ext4_clear_request_list();
3167 			goto exit_thread;
3168 		}
3169 	}
3170 
3171 exit_thread:
3172 	/*
3173 	 * It looks like the request list is empty, but we need
3174 	 * to check it under the li_list_mtx lock, to prevent any
3175 	 * additions into it, and of course we should lock ext4_li_mtx
3176 	 * to atomically free the list and ext4_li_info, because at
3177 	 * this point another ext4 filesystem could be registering
3178 	 * new one.
3179 	 */
3180 	mutex_lock(&ext4_li_mtx);
3181 	mutex_lock(&eli->li_list_mtx);
3182 	if (!list_empty(&eli->li_request_list)) {
3183 		mutex_unlock(&eli->li_list_mtx);
3184 		mutex_unlock(&ext4_li_mtx);
3185 		goto cont_thread;
3186 	}
3187 	mutex_unlock(&eli->li_list_mtx);
3188 	kfree(ext4_li_info);
3189 	ext4_li_info = NULL;
3190 	mutex_unlock(&ext4_li_mtx);
3191 
3192 	return 0;
3193 }
3194 
3195 static void ext4_clear_request_list(void)
3196 {
3197 	struct list_head *pos, *n;
3198 	struct ext4_li_request *elr;
3199 
3200 	mutex_lock(&ext4_li_info->li_list_mtx);
3201 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3202 		elr = list_entry(pos, struct ext4_li_request,
3203 				 lr_request);
3204 		ext4_remove_li_request(elr);
3205 	}
3206 	mutex_unlock(&ext4_li_info->li_list_mtx);
3207 }
3208 
3209 static int ext4_run_lazyinit_thread(void)
3210 {
3211 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3212 					 ext4_li_info, "ext4lazyinit");
3213 	if (IS_ERR(ext4_lazyinit_task)) {
3214 		int err = PTR_ERR(ext4_lazyinit_task);
3215 		ext4_clear_request_list();
3216 		kfree(ext4_li_info);
3217 		ext4_li_info = NULL;
3218 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3219 				 "initialization thread\n",
3220 				 err);
3221 		return err;
3222 	}
3223 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3224 	return 0;
3225 }
3226 
3227 /*
3228  * Check whether it make sense to run itable init. thread or not.
3229  * If there is at least one uninitialized inode table, return
3230  * corresponding group number, else the loop goes through all
3231  * groups and return total number of groups.
3232  */
3233 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3234 {
3235 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3236 	struct ext4_group_desc *gdp = NULL;
3237 
3238 	if (!ext4_has_group_desc_csum(sb))
3239 		return ngroups;
3240 
3241 	for (group = 0; group < ngroups; group++) {
3242 		gdp = ext4_get_group_desc(sb, group, NULL);
3243 		if (!gdp)
3244 			continue;
3245 
3246 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3247 			break;
3248 	}
3249 
3250 	return group;
3251 }
3252 
3253 static int ext4_li_info_new(void)
3254 {
3255 	struct ext4_lazy_init *eli = NULL;
3256 
3257 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3258 	if (!eli)
3259 		return -ENOMEM;
3260 
3261 	INIT_LIST_HEAD(&eli->li_request_list);
3262 	mutex_init(&eli->li_list_mtx);
3263 
3264 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3265 
3266 	ext4_li_info = eli;
3267 
3268 	return 0;
3269 }
3270 
3271 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3272 					    ext4_group_t start)
3273 {
3274 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3275 	struct ext4_li_request *elr;
3276 
3277 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3278 	if (!elr)
3279 		return NULL;
3280 
3281 	elr->lr_super = sb;
3282 	elr->lr_sbi = sbi;
3283 	elr->lr_next_group = start;
3284 
3285 	/*
3286 	 * Randomize first schedule time of the request to
3287 	 * spread the inode table initialization requests
3288 	 * better.
3289 	 */
3290 	elr->lr_next_sched = jiffies + (prandom_u32() %
3291 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3292 	return elr;
3293 }
3294 
3295 int ext4_register_li_request(struct super_block *sb,
3296 			     ext4_group_t first_not_zeroed)
3297 {
3298 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3299 	struct ext4_li_request *elr = NULL;
3300 	ext4_group_t ngroups = sbi->s_groups_count;
3301 	int ret = 0;
3302 
3303 	mutex_lock(&ext4_li_mtx);
3304 	if (sbi->s_li_request != NULL) {
3305 		/*
3306 		 * Reset timeout so it can be computed again, because
3307 		 * s_li_wait_mult might have changed.
3308 		 */
3309 		sbi->s_li_request->lr_timeout = 0;
3310 		goto out;
3311 	}
3312 
3313 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3314 	    !test_opt(sb, INIT_INODE_TABLE))
3315 		goto out;
3316 
3317 	elr = ext4_li_request_new(sb, first_not_zeroed);
3318 	if (!elr) {
3319 		ret = -ENOMEM;
3320 		goto out;
3321 	}
3322 
3323 	if (NULL == ext4_li_info) {
3324 		ret = ext4_li_info_new();
3325 		if (ret)
3326 			goto out;
3327 	}
3328 
3329 	mutex_lock(&ext4_li_info->li_list_mtx);
3330 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3331 	mutex_unlock(&ext4_li_info->li_list_mtx);
3332 
3333 	sbi->s_li_request = elr;
3334 	/*
3335 	 * set elr to NULL here since it has been inserted to
3336 	 * the request_list and the removal and free of it is
3337 	 * handled by ext4_clear_request_list from now on.
3338 	 */
3339 	elr = NULL;
3340 
3341 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3342 		ret = ext4_run_lazyinit_thread();
3343 		if (ret)
3344 			goto out;
3345 	}
3346 out:
3347 	mutex_unlock(&ext4_li_mtx);
3348 	if (ret)
3349 		kfree(elr);
3350 	return ret;
3351 }
3352 
3353 /*
3354  * We do not need to lock anything since this is called on
3355  * module unload.
3356  */
3357 static void ext4_destroy_lazyinit_thread(void)
3358 {
3359 	/*
3360 	 * If thread exited earlier
3361 	 * there's nothing to be done.
3362 	 */
3363 	if (!ext4_li_info || !ext4_lazyinit_task)
3364 		return;
3365 
3366 	kthread_stop(ext4_lazyinit_task);
3367 }
3368 
3369 static int set_journal_csum_feature_set(struct super_block *sb)
3370 {
3371 	int ret = 1;
3372 	int compat, incompat;
3373 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3374 
3375 	if (ext4_has_metadata_csum(sb)) {
3376 		/* journal checksum v3 */
3377 		compat = 0;
3378 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3379 	} else {
3380 		/* journal checksum v1 */
3381 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3382 		incompat = 0;
3383 	}
3384 
3385 	jbd2_journal_clear_features(sbi->s_journal,
3386 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3387 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3388 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3389 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3390 		ret = jbd2_journal_set_features(sbi->s_journal,
3391 				compat, 0,
3392 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3393 				incompat);
3394 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3395 		ret = jbd2_journal_set_features(sbi->s_journal,
3396 				compat, 0,
3397 				incompat);
3398 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3399 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3400 	} else {
3401 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3402 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3403 	}
3404 
3405 	return ret;
3406 }
3407 
3408 /*
3409  * Note: calculating the overhead so we can be compatible with
3410  * historical BSD practice is quite difficult in the face of
3411  * clusters/bigalloc.  This is because multiple metadata blocks from
3412  * different block group can end up in the same allocation cluster.
3413  * Calculating the exact overhead in the face of clustered allocation
3414  * requires either O(all block bitmaps) in memory or O(number of block
3415  * groups**2) in time.  We will still calculate the superblock for
3416  * older file systems --- and if we come across with a bigalloc file
3417  * system with zero in s_overhead_clusters the estimate will be close to
3418  * correct especially for very large cluster sizes --- but for newer
3419  * file systems, it's better to calculate this figure once at mkfs
3420  * time, and store it in the superblock.  If the superblock value is
3421  * present (even for non-bigalloc file systems), we will use it.
3422  */
3423 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3424 			  char *buf)
3425 {
3426 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3427 	struct ext4_group_desc	*gdp;
3428 	ext4_fsblk_t		first_block, last_block, b;
3429 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3430 	int			s, j, count = 0;
3431 
3432 	if (!ext4_has_feature_bigalloc(sb))
3433 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3434 			sbi->s_itb_per_group + 2);
3435 
3436 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3437 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3438 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3439 	for (i = 0; i < ngroups; i++) {
3440 		gdp = ext4_get_group_desc(sb, i, NULL);
3441 		b = ext4_block_bitmap(sb, gdp);
3442 		if (b >= first_block && b <= last_block) {
3443 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3444 			count++;
3445 		}
3446 		b = ext4_inode_bitmap(sb, gdp);
3447 		if (b >= first_block && b <= last_block) {
3448 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3449 			count++;
3450 		}
3451 		b = ext4_inode_table(sb, gdp);
3452 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3453 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3454 				int c = EXT4_B2C(sbi, b - first_block);
3455 				ext4_set_bit(c, buf);
3456 				count++;
3457 			}
3458 		if (i != grp)
3459 			continue;
3460 		s = 0;
3461 		if (ext4_bg_has_super(sb, grp)) {
3462 			ext4_set_bit(s++, buf);
3463 			count++;
3464 		}
3465 		j = ext4_bg_num_gdb(sb, grp);
3466 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3467 			ext4_error(sb, "Invalid number of block group "
3468 				   "descriptor blocks: %d", j);
3469 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3470 		}
3471 		count += j;
3472 		for (; j > 0; j--)
3473 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3474 	}
3475 	if (!count)
3476 		return 0;
3477 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3478 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3479 }
3480 
3481 /*
3482  * Compute the overhead and stash it in sbi->s_overhead
3483  */
3484 int ext4_calculate_overhead(struct super_block *sb)
3485 {
3486 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3487 	struct ext4_super_block *es = sbi->s_es;
3488 	struct inode *j_inode;
3489 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3490 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3491 	ext4_fsblk_t overhead = 0;
3492 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3493 
3494 	if (!buf)
3495 		return -ENOMEM;
3496 
3497 	/*
3498 	 * Compute the overhead (FS structures).  This is constant
3499 	 * for a given filesystem unless the number of block groups
3500 	 * changes so we cache the previous value until it does.
3501 	 */
3502 
3503 	/*
3504 	 * All of the blocks before first_data_block are overhead
3505 	 */
3506 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3507 
3508 	/*
3509 	 * Add the overhead found in each block group
3510 	 */
3511 	for (i = 0; i < ngroups; i++) {
3512 		int blks;
3513 
3514 		blks = count_overhead(sb, i, buf);
3515 		overhead += blks;
3516 		if (blks)
3517 			memset(buf, 0, PAGE_SIZE);
3518 		cond_resched();
3519 	}
3520 
3521 	/*
3522 	 * Add the internal journal blocks whether the journal has been
3523 	 * loaded or not
3524 	 */
3525 	if (sbi->s_journal && !sbi->journal_bdev)
3526 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3527 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3528 		j_inode = ext4_get_journal_inode(sb, j_inum);
3529 		if (j_inode) {
3530 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3531 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3532 			iput(j_inode);
3533 		} else {
3534 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3535 		}
3536 	}
3537 	sbi->s_overhead = overhead;
3538 	smp_wmb();
3539 	free_page((unsigned long) buf);
3540 	return 0;
3541 }
3542 
3543 static void ext4_clamp_want_extra_isize(struct super_block *sb)
3544 {
3545 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3546 	struct ext4_super_block *es = sbi->s_es;
3547 
3548 	/* determine the minimum size of new large inodes, if present */
3549 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
3550 	    sbi->s_want_extra_isize == 0) {
3551 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3552 						     EXT4_GOOD_OLD_INODE_SIZE;
3553 		if (ext4_has_feature_extra_isize(sb)) {
3554 			if (sbi->s_want_extra_isize <
3555 			    le16_to_cpu(es->s_want_extra_isize))
3556 				sbi->s_want_extra_isize =
3557 					le16_to_cpu(es->s_want_extra_isize);
3558 			if (sbi->s_want_extra_isize <
3559 			    le16_to_cpu(es->s_min_extra_isize))
3560 				sbi->s_want_extra_isize =
3561 					le16_to_cpu(es->s_min_extra_isize);
3562 		}
3563 	}
3564 	/* Check if enough inode space is available */
3565 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3566 							sbi->s_inode_size) {
3567 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3568 						       EXT4_GOOD_OLD_INODE_SIZE;
3569 		ext4_msg(sb, KERN_INFO,
3570 			 "required extra inode space not available");
3571 	}
3572 }
3573 
3574 static void ext4_set_resv_clusters(struct super_block *sb)
3575 {
3576 	ext4_fsblk_t resv_clusters;
3577 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3578 
3579 	/*
3580 	 * There's no need to reserve anything when we aren't using extents.
3581 	 * The space estimates are exact, there are no unwritten extents,
3582 	 * hole punching doesn't need new metadata... This is needed especially
3583 	 * to keep ext2/3 backward compatibility.
3584 	 */
3585 	if (!ext4_has_feature_extents(sb))
3586 		return;
3587 	/*
3588 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3589 	 * This should cover the situations where we can not afford to run
3590 	 * out of space like for example punch hole, or converting
3591 	 * unwritten extents in delalloc path. In most cases such
3592 	 * allocation would require 1, or 2 blocks, higher numbers are
3593 	 * very rare.
3594 	 */
3595 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3596 			 sbi->s_cluster_bits);
3597 
3598 	do_div(resv_clusters, 50);
3599 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3600 
3601 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3602 }
3603 
3604 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3605 {
3606 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3607 	char *orig_data = kstrdup(data, GFP_KERNEL);
3608 	struct buffer_head *bh;
3609 	struct ext4_super_block *es = NULL;
3610 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3611 	ext4_fsblk_t block;
3612 	ext4_fsblk_t sb_block = get_sb_block(&data);
3613 	ext4_fsblk_t logical_sb_block;
3614 	unsigned long offset = 0;
3615 	unsigned long journal_devnum = 0;
3616 	unsigned long def_mount_opts;
3617 	struct inode *root;
3618 	const char *descr;
3619 	int ret = -ENOMEM;
3620 	int blocksize, clustersize;
3621 	unsigned int db_count;
3622 	unsigned int i;
3623 	int needs_recovery, has_huge_files, has_bigalloc;
3624 	__u64 blocks_count;
3625 	int err = 0;
3626 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3627 	ext4_group_t first_not_zeroed;
3628 
3629 	if ((data && !orig_data) || !sbi)
3630 		goto out_free_base;
3631 
3632 	sbi->s_daxdev = dax_dev;
3633 	sbi->s_blockgroup_lock =
3634 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3635 	if (!sbi->s_blockgroup_lock)
3636 		goto out_free_base;
3637 
3638 	sb->s_fs_info = sbi;
3639 	sbi->s_sb = sb;
3640 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3641 	sbi->s_sb_block = sb_block;
3642 	if (sb->s_bdev->bd_part)
3643 		sbi->s_sectors_written_start =
3644 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3645 
3646 	/* Cleanup superblock name */
3647 	strreplace(sb->s_id, '/', '!');
3648 
3649 	/* -EINVAL is default */
3650 	ret = -EINVAL;
3651 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3652 	if (!blocksize) {
3653 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3654 		goto out_fail;
3655 	}
3656 
3657 	/*
3658 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3659 	 * block sizes.  We need to calculate the offset from buffer start.
3660 	 */
3661 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3662 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3663 		offset = do_div(logical_sb_block, blocksize);
3664 	} else {
3665 		logical_sb_block = sb_block;
3666 	}
3667 
3668 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3669 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3670 		goto out_fail;
3671 	}
3672 	/*
3673 	 * Note: s_es must be initialized as soon as possible because
3674 	 *       some ext4 macro-instructions depend on its value
3675 	 */
3676 	es = (struct ext4_super_block *) (bh->b_data + offset);
3677 	sbi->s_es = es;
3678 	sb->s_magic = le16_to_cpu(es->s_magic);
3679 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3680 		goto cantfind_ext4;
3681 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3682 
3683 	/* Warn if metadata_csum and gdt_csum are both set. */
3684 	if (ext4_has_feature_metadata_csum(sb) &&
3685 	    ext4_has_feature_gdt_csum(sb))
3686 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3687 			     "redundant flags; please run fsck.");
3688 
3689 	/* Check for a known checksum algorithm */
3690 	if (!ext4_verify_csum_type(sb, es)) {
3691 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3692 			 "unknown checksum algorithm.");
3693 		silent = 1;
3694 		goto cantfind_ext4;
3695 	}
3696 
3697 	/* Load the checksum driver */
3698 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3699 	if (IS_ERR(sbi->s_chksum_driver)) {
3700 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3701 		ret = PTR_ERR(sbi->s_chksum_driver);
3702 		sbi->s_chksum_driver = NULL;
3703 		goto failed_mount;
3704 	}
3705 
3706 	/* Check superblock checksum */
3707 	if (!ext4_superblock_csum_verify(sb, es)) {
3708 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3709 			 "invalid superblock checksum.  Run e2fsck?");
3710 		silent = 1;
3711 		ret = -EFSBADCRC;
3712 		goto cantfind_ext4;
3713 	}
3714 
3715 	/* Precompute checksum seed for all metadata */
3716 	if (ext4_has_feature_csum_seed(sb))
3717 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3718 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3719 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3720 					       sizeof(es->s_uuid));
3721 
3722 	/* Set defaults before we parse the mount options */
3723 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3724 	set_opt(sb, INIT_INODE_TABLE);
3725 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3726 		set_opt(sb, DEBUG);
3727 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3728 		set_opt(sb, GRPID);
3729 	if (def_mount_opts & EXT4_DEFM_UID16)
3730 		set_opt(sb, NO_UID32);
3731 	/* xattr user namespace & acls are now defaulted on */
3732 	set_opt(sb, XATTR_USER);
3733 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3734 	set_opt(sb, POSIX_ACL);
3735 #endif
3736 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3737 	if (ext4_has_metadata_csum(sb))
3738 		set_opt(sb, JOURNAL_CHECKSUM);
3739 
3740 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3741 		set_opt(sb, JOURNAL_DATA);
3742 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3743 		set_opt(sb, ORDERED_DATA);
3744 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3745 		set_opt(sb, WRITEBACK_DATA);
3746 
3747 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3748 		set_opt(sb, ERRORS_PANIC);
3749 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3750 		set_opt(sb, ERRORS_CONT);
3751 	else
3752 		set_opt(sb, ERRORS_RO);
3753 	/* block_validity enabled by default; disable with noblock_validity */
3754 	set_opt(sb, BLOCK_VALIDITY);
3755 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3756 		set_opt(sb, DISCARD);
3757 
3758 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3759 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3760 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3761 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3762 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3763 
3764 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3765 		set_opt(sb, BARRIER);
3766 
3767 	/*
3768 	 * enable delayed allocation by default
3769 	 * Use -o nodelalloc to turn it off
3770 	 */
3771 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3772 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3773 		set_opt(sb, DELALLOC);
3774 
3775 	/*
3776 	 * set default s_li_wait_mult for lazyinit, for the case there is
3777 	 * no mount option specified.
3778 	 */
3779 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3780 
3781 	if (sbi->s_es->s_mount_opts[0]) {
3782 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3783 					      sizeof(sbi->s_es->s_mount_opts),
3784 					      GFP_KERNEL);
3785 		if (!s_mount_opts)
3786 			goto failed_mount;
3787 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3788 				   &journal_ioprio, 0)) {
3789 			ext4_msg(sb, KERN_WARNING,
3790 				 "failed to parse options in superblock: %s",
3791 				 s_mount_opts);
3792 		}
3793 		kfree(s_mount_opts);
3794 	}
3795 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3796 	if (!parse_options((char *) data, sb, &journal_devnum,
3797 			   &journal_ioprio, 0))
3798 		goto failed_mount;
3799 
3800 #ifdef CONFIG_UNICODE
3801 	if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
3802 		const struct ext4_sb_encodings *encoding_info;
3803 		struct unicode_map *encoding;
3804 		__u16 encoding_flags;
3805 
3806 		if (ext4_has_feature_encrypt(sb)) {
3807 			ext4_msg(sb, KERN_ERR,
3808 				 "Can't mount with encoding and encryption");
3809 			goto failed_mount;
3810 		}
3811 
3812 		if (ext4_sb_read_encoding(es, &encoding_info,
3813 					  &encoding_flags)) {
3814 			ext4_msg(sb, KERN_ERR,
3815 				 "Encoding requested by superblock is unknown");
3816 			goto failed_mount;
3817 		}
3818 
3819 		encoding = utf8_load(encoding_info->version);
3820 		if (IS_ERR(encoding)) {
3821 			ext4_msg(sb, KERN_ERR,
3822 				 "can't mount with superblock charset: %s-%s "
3823 				 "not supported by the kernel. flags: 0x%x.",
3824 				 encoding_info->name, encoding_info->version,
3825 				 encoding_flags);
3826 			goto failed_mount;
3827 		}
3828 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
3829 			 "%s-%s with flags 0x%hx", encoding_info->name,
3830 			 encoding_info->version?:"\b", encoding_flags);
3831 
3832 		sbi->s_encoding = encoding;
3833 		sbi->s_encoding_flags = encoding_flags;
3834 	}
3835 #endif
3836 
3837 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3838 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3839 			    "with data=journal disables delayed "
3840 			    "allocation and O_DIRECT support!\n");
3841 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3842 			ext4_msg(sb, KERN_ERR, "can't mount with "
3843 				 "both data=journal and delalloc");
3844 			goto failed_mount;
3845 		}
3846 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3847 			ext4_msg(sb, KERN_ERR, "can't mount with "
3848 				 "both data=journal and dioread_nolock");
3849 			goto failed_mount;
3850 		}
3851 		if (test_opt(sb, DAX)) {
3852 			ext4_msg(sb, KERN_ERR, "can't mount with "
3853 				 "both data=journal and dax");
3854 			goto failed_mount;
3855 		}
3856 		if (ext4_has_feature_encrypt(sb)) {
3857 			ext4_msg(sb, KERN_WARNING,
3858 				 "encrypted files will use data=ordered "
3859 				 "instead of data journaling mode");
3860 		}
3861 		if (test_opt(sb, DELALLOC))
3862 			clear_opt(sb, DELALLOC);
3863 	} else {
3864 		sb->s_iflags |= SB_I_CGROUPWB;
3865 	}
3866 
3867 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3868 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3869 
3870 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3871 	    (ext4_has_compat_features(sb) ||
3872 	     ext4_has_ro_compat_features(sb) ||
3873 	     ext4_has_incompat_features(sb)))
3874 		ext4_msg(sb, KERN_WARNING,
3875 		       "feature flags set on rev 0 fs, "
3876 		       "running e2fsck is recommended");
3877 
3878 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3879 		set_opt2(sb, HURD_COMPAT);
3880 		if (ext4_has_feature_64bit(sb)) {
3881 			ext4_msg(sb, KERN_ERR,
3882 				 "The Hurd can't support 64-bit file systems");
3883 			goto failed_mount;
3884 		}
3885 
3886 		/*
3887 		 * ea_inode feature uses l_i_version field which is not
3888 		 * available in HURD_COMPAT mode.
3889 		 */
3890 		if (ext4_has_feature_ea_inode(sb)) {
3891 			ext4_msg(sb, KERN_ERR,
3892 				 "ea_inode feature is not supported for Hurd");
3893 			goto failed_mount;
3894 		}
3895 	}
3896 
3897 	if (IS_EXT2_SB(sb)) {
3898 		if (ext2_feature_set_ok(sb))
3899 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3900 				 "using the ext4 subsystem");
3901 		else {
3902 			/*
3903 			 * If we're probing be silent, if this looks like
3904 			 * it's actually an ext[34] filesystem.
3905 			 */
3906 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3907 				goto failed_mount;
3908 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3909 				 "to feature incompatibilities");
3910 			goto failed_mount;
3911 		}
3912 	}
3913 
3914 	if (IS_EXT3_SB(sb)) {
3915 		if (ext3_feature_set_ok(sb))
3916 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3917 				 "using the ext4 subsystem");
3918 		else {
3919 			/*
3920 			 * If we're probing be silent, if this looks like
3921 			 * it's actually an ext4 filesystem.
3922 			 */
3923 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3924 				goto failed_mount;
3925 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3926 				 "to feature incompatibilities");
3927 			goto failed_mount;
3928 		}
3929 	}
3930 
3931 	/*
3932 	 * Check feature flags regardless of the revision level, since we
3933 	 * previously didn't change the revision level when setting the flags,
3934 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3935 	 */
3936 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3937 		goto failed_mount;
3938 
3939 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3940 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3941 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3942 		ext4_msg(sb, KERN_ERR,
3943 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3944 			 blocksize, le32_to_cpu(es->s_log_block_size));
3945 		goto failed_mount;
3946 	}
3947 	if (le32_to_cpu(es->s_log_block_size) >
3948 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3949 		ext4_msg(sb, KERN_ERR,
3950 			 "Invalid log block size: %u",
3951 			 le32_to_cpu(es->s_log_block_size));
3952 		goto failed_mount;
3953 	}
3954 	if (le32_to_cpu(es->s_log_cluster_size) >
3955 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3956 		ext4_msg(sb, KERN_ERR,
3957 			 "Invalid log cluster size: %u",
3958 			 le32_to_cpu(es->s_log_cluster_size));
3959 		goto failed_mount;
3960 	}
3961 
3962 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3963 		ext4_msg(sb, KERN_ERR,
3964 			 "Number of reserved GDT blocks insanely large: %d",
3965 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3966 		goto failed_mount;
3967 	}
3968 
3969 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3970 		if (ext4_has_feature_inline_data(sb)) {
3971 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3972 					" that may contain inline data");
3973 			goto failed_mount;
3974 		}
3975 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
3976 			ext4_msg(sb, KERN_ERR,
3977 				"DAX unsupported by block device.");
3978 			goto failed_mount;
3979 		}
3980 	}
3981 
3982 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3983 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3984 			 es->s_encryption_level);
3985 		goto failed_mount;
3986 	}
3987 
3988 	if (sb->s_blocksize != blocksize) {
3989 		/* Validate the filesystem blocksize */
3990 		if (!sb_set_blocksize(sb, blocksize)) {
3991 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3992 					blocksize);
3993 			goto failed_mount;
3994 		}
3995 
3996 		brelse(bh);
3997 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3998 		offset = do_div(logical_sb_block, blocksize);
3999 		bh = sb_bread_unmovable(sb, logical_sb_block);
4000 		if (!bh) {
4001 			ext4_msg(sb, KERN_ERR,
4002 			       "Can't read superblock on 2nd try");
4003 			goto failed_mount;
4004 		}
4005 		es = (struct ext4_super_block *)(bh->b_data + offset);
4006 		sbi->s_es = es;
4007 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4008 			ext4_msg(sb, KERN_ERR,
4009 			       "Magic mismatch, very weird!");
4010 			goto failed_mount;
4011 		}
4012 	}
4013 
4014 	has_huge_files = ext4_has_feature_huge_file(sb);
4015 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4016 						      has_huge_files);
4017 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4018 
4019 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4020 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4021 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4022 	} else {
4023 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4024 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4025 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4026 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4027 				 sbi->s_first_ino);
4028 			goto failed_mount;
4029 		}
4030 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4031 		    (!is_power_of_2(sbi->s_inode_size)) ||
4032 		    (sbi->s_inode_size > blocksize)) {
4033 			ext4_msg(sb, KERN_ERR,
4034 			       "unsupported inode size: %d",
4035 			       sbi->s_inode_size);
4036 			goto failed_mount;
4037 		}
4038 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
4039 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
4040 	}
4041 
4042 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4043 	if (ext4_has_feature_64bit(sb)) {
4044 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4045 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4046 		    !is_power_of_2(sbi->s_desc_size)) {
4047 			ext4_msg(sb, KERN_ERR,
4048 			       "unsupported descriptor size %lu",
4049 			       sbi->s_desc_size);
4050 			goto failed_mount;
4051 		}
4052 	} else
4053 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4054 
4055 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4056 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4057 
4058 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4059 	if (sbi->s_inodes_per_block == 0)
4060 		goto cantfind_ext4;
4061 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4062 	    sbi->s_inodes_per_group > blocksize * 8) {
4063 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4064 			 sbi->s_blocks_per_group);
4065 		goto failed_mount;
4066 	}
4067 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4068 					sbi->s_inodes_per_block;
4069 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4070 	sbi->s_sbh = bh;
4071 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4072 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4073 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4074 
4075 	for (i = 0; i < 4; i++)
4076 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4077 	sbi->s_def_hash_version = es->s_def_hash_version;
4078 	if (ext4_has_feature_dir_index(sb)) {
4079 		i = le32_to_cpu(es->s_flags);
4080 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4081 			sbi->s_hash_unsigned = 3;
4082 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4083 #ifdef __CHAR_UNSIGNED__
4084 			if (!sb_rdonly(sb))
4085 				es->s_flags |=
4086 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4087 			sbi->s_hash_unsigned = 3;
4088 #else
4089 			if (!sb_rdonly(sb))
4090 				es->s_flags |=
4091 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4092 #endif
4093 		}
4094 	}
4095 
4096 	/* Handle clustersize */
4097 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4098 	has_bigalloc = ext4_has_feature_bigalloc(sb);
4099 	if (has_bigalloc) {
4100 		if (clustersize < blocksize) {
4101 			ext4_msg(sb, KERN_ERR,
4102 				 "cluster size (%d) smaller than "
4103 				 "block size (%d)", clustersize, blocksize);
4104 			goto failed_mount;
4105 		}
4106 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4107 			le32_to_cpu(es->s_log_block_size);
4108 		sbi->s_clusters_per_group =
4109 			le32_to_cpu(es->s_clusters_per_group);
4110 		if (sbi->s_clusters_per_group > blocksize * 8) {
4111 			ext4_msg(sb, KERN_ERR,
4112 				 "#clusters per group too big: %lu",
4113 				 sbi->s_clusters_per_group);
4114 			goto failed_mount;
4115 		}
4116 		if (sbi->s_blocks_per_group !=
4117 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4118 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4119 				 "clusters per group (%lu) inconsistent",
4120 				 sbi->s_blocks_per_group,
4121 				 sbi->s_clusters_per_group);
4122 			goto failed_mount;
4123 		}
4124 	} else {
4125 		if (clustersize != blocksize) {
4126 			ext4_msg(sb, KERN_ERR,
4127 				 "fragment/cluster size (%d) != "
4128 				 "block size (%d)", clustersize, blocksize);
4129 			goto failed_mount;
4130 		}
4131 		if (sbi->s_blocks_per_group > blocksize * 8) {
4132 			ext4_msg(sb, KERN_ERR,
4133 				 "#blocks per group too big: %lu",
4134 				 sbi->s_blocks_per_group);
4135 			goto failed_mount;
4136 		}
4137 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4138 		sbi->s_cluster_bits = 0;
4139 	}
4140 	sbi->s_cluster_ratio = clustersize / blocksize;
4141 
4142 	/* Do we have standard group size of clustersize * 8 blocks ? */
4143 	if (sbi->s_blocks_per_group == clustersize << 3)
4144 		set_opt2(sb, STD_GROUP_SIZE);
4145 
4146 	/*
4147 	 * Test whether we have more sectors than will fit in sector_t,
4148 	 * and whether the max offset is addressable by the page cache.
4149 	 */
4150 	err = generic_check_addressable(sb->s_blocksize_bits,
4151 					ext4_blocks_count(es));
4152 	if (err) {
4153 		ext4_msg(sb, KERN_ERR, "filesystem"
4154 			 " too large to mount safely on this system");
4155 		goto failed_mount;
4156 	}
4157 
4158 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4159 		goto cantfind_ext4;
4160 
4161 	/* check blocks count against device size */
4162 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4163 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4164 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4165 		       "exceeds size of device (%llu blocks)",
4166 		       ext4_blocks_count(es), blocks_count);
4167 		goto failed_mount;
4168 	}
4169 
4170 	/*
4171 	 * It makes no sense for the first data block to be beyond the end
4172 	 * of the filesystem.
4173 	 */
4174 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4175 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4176 			 "block %u is beyond end of filesystem (%llu)",
4177 			 le32_to_cpu(es->s_first_data_block),
4178 			 ext4_blocks_count(es));
4179 		goto failed_mount;
4180 	}
4181 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4182 	    (sbi->s_cluster_ratio == 1)) {
4183 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4184 			 "block is 0 with a 1k block and cluster size");
4185 		goto failed_mount;
4186 	}
4187 
4188 	blocks_count = (ext4_blocks_count(es) -
4189 			le32_to_cpu(es->s_first_data_block) +
4190 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4191 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4192 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4193 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4194 		       "(block count %llu, first data block %u, "
4195 		       "blocks per group %lu)", sbi->s_groups_count,
4196 		       ext4_blocks_count(es),
4197 		       le32_to_cpu(es->s_first_data_block),
4198 		       EXT4_BLOCKS_PER_GROUP(sb));
4199 		goto failed_mount;
4200 	}
4201 	sbi->s_groups_count = blocks_count;
4202 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4203 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4204 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4205 	    le32_to_cpu(es->s_inodes_count)) {
4206 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4207 			 le32_to_cpu(es->s_inodes_count),
4208 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4209 		ret = -EINVAL;
4210 		goto failed_mount;
4211 	}
4212 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4213 		   EXT4_DESC_PER_BLOCK(sb);
4214 	if (ext4_has_feature_meta_bg(sb)) {
4215 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4216 			ext4_msg(sb, KERN_WARNING,
4217 				 "first meta block group too large: %u "
4218 				 "(group descriptor block count %u)",
4219 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4220 			goto failed_mount;
4221 		}
4222 	}
4223 	sbi->s_group_desc = kvmalloc_array(db_count,
4224 					   sizeof(struct buffer_head *),
4225 					   GFP_KERNEL);
4226 	if (sbi->s_group_desc == NULL) {
4227 		ext4_msg(sb, KERN_ERR, "not enough memory");
4228 		ret = -ENOMEM;
4229 		goto failed_mount;
4230 	}
4231 
4232 	bgl_lock_init(sbi->s_blockgroup_lock);
4233 
4234 	/* Pre-read the descriptors into the buffer cache */
4235 	for (i = 0; i < db_count; i++) {
4236 		block = descriptor_loc(sb, logical_sb_block, i);
4237 		sb_breadahead(sb, block);
4238 	}
4239 
4240 	for (i = 0; i < db_count; i++) {
4241 		block = descriptor_loc(sb, logical_sb_block, i);
4242 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4243 		if (!sbi->s_group_desc[i]) {
4244 			ext4_msg(sb, KERN_ERR,
4245 			       "can't read group descriptor %d", i);
4246 			db_count = i;
4247 			goto failed_mount2;
4248 		}
4249 	}
4250 	sbi->s_gdb_count = db_count;
4251 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4252 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4253 		ret = -EFSCORRUPTED;
4254 		goto failed_mount2;
4255 	}
4256 
4257 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4258 
4259 	/* Register extent status tree shrinker */
4260 	if (ext4_es_register_shrinker(sbi))
4261 		goto failed_mount3;
4262 
4263 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4264 	sbi->s_extent_max_zeroout_kb = 32;
4265 
4266 	/*
4267 	 * set up enough so that it can read an inode
4268 	 */
4269 	sb->s_op = &ext4_sops;
4270 	sb->s_export_op = &ext4_export_ops;
4271 	sb->s_xattr = ext4_xattr_handlers;
4272 #ifdef CONFIG_FS_ENCRYPTION
4273 	sb->s_cop = &ext4_cryptops;
4274 #endif
4275 #ifdef CONFIG_QUOTA
4276 	sb->dq_op = &ext4_quota_operations;
4277 	if (ext4_has_feature_quota(sb))
4278 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4279 	else
4280 		sb->s_qcop = &ext4_qctl_operations;
4281 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4282 #endif
4283 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4284 
4285 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4286 	mutex_init(&sbi->s_orphan_lock);
4287 
4288 	sb->s_root = NULL;
4289 
4290 	needs_recovery = (es->s_last_orphan != 0 ||
4291 			  ext4_has_feature_journal_needs_recovery(sb));
4292 
4293 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4294 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4295 			goto failed_mount3a;
4296 
4297 	/*
4298 	 * The first inode we look at is the journal inode.  Don't try
4299 	 * root first: it may be modified in the journal!
4300 	 */
4301 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4302 		err = ext4_load_journal(sb, es, journal_devnum);
4303 		if (err)
4304 			goto failed_mount3a;
4305 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4306 		   ext4_has_feature_journal_needs_recovery(sb)) {
4307 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4308 		       "suppressed and not mounted read-only");
4309 		goto failed_mount_wq;
4310 	} else {
4311 		/* Nojournal mode, all journal mount options are illegal */
4312 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4313 			ext4_msg(sb, KERN_ERR, "can't mount with "
4314 				 "journal_checksum, fs mounted w/o journal");
4315 			goto failed_mount_wq;
4316 		}
4317 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4318 			ext4_msg(sb, KERN_ERR, "can't mount with "
4319 				 "journal_async_commit, fs mounted w/o journal");
4320 			goto failed_mount_wq;
4321 		}
4322 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4323 			ext4_msg(sb, KERN_ERR, "can't mount with "
4324 				 "commit=%lu, fs mounted w/o journal",
4325 				 sbi->s_commit_interval / HZ);
4326 			goto failed_mount_wq;
4327 		}
4328 		if (EXT4_MOUNT_DATA_FLAGS &
4329 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4330 			ext4_msg(sb, KERN_ERR, "can't mount with "
4331 				 "data=, fs mounted w/o journal");
4332 			goto failed_mount_wq;
4333 		}
4334 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4335 		clear_opt(sb, JOURNAL_CHECKSUM);
4336 		clear_opt(sb, DATA_FLAGS);
4337 		sbi->s_journal = NULL;
4338 		needs_recovery = 0;
4339 		goto no_journal;
4340 	}
4341 
4342 	if (ext4_has_feature_64bit(sb) &&
4343 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4344 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4345 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4346 		goto failed_mount_wq;
4347 	}
4348 
4349 	if (!set_journal_csum_feature_set(sb)) {
4350 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4351 			 "feature set");
4352 		goto failed_mount_wq;
4353 	}
4354 
4355 	/* We have now updated the journal if required, so we can
4356 	 * validate the data journaling mode. */
4357 	switch (test_opt(sb, DATA_FLAGS)) {
4358 	case 0:
4359 		/* No mode set, assume a default based on the journal
4360 		 * capabilities: ORDERED_DATA if the journal can
4361 		 * cope, else JOURNAL_DATA
4362 		 */
4363 		if (jbd2_journal_check_available_features
4364 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4365 			set_opt(sb, ORDERED_DATA);
4366 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4367 		} else {
4368 			set_opt(sb, JOURNAL_DATA);
4369 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4370 		}
4371 		break;
4372 
4373 	case EXT4_MOUNT_ORDERED_DATA:
4374 	case EXT4_MOUNT_WRITEBACK_DATA:
4375 		if (!jbd2_journal_check_available_features
4376 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4377 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4378 			       "requested data journaling mode");
4379 			goto failed_mount_wq;
4380 		}
4381 	default:
4382 		break;
4383 	}
4384 
4385 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4386 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4387 		ext4_msg(sb, KERN_ERR, "can't mount with "
4388 			"journal_async_commit in data=ordered mode");
4389 		goto failed_mount_wq;
4390 	}
4391 
4392 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4393 
4394 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4395 
4396 no_journal:
4397 	if (!test_opt(sb, NO_MBCACHE)) {
4398 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4399 		if (!sbi->s_ea_block_cache) {
4400 			ext4_msg(sb, KERN_ERR,
4401 				 "Failed to create ea_block_cache");
4402 			goto failed_mount_wq;
4403 		}
4404 
4405 		if (ext4_has_feature_ea_inode(sb)) {
4406 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4407 			if (!sbi->s_ea_inode_cache) {
4408 				ext4_msg(sb, KERN_ERR,
4409 					 "Failed to create ea_inode_cache");
4410 				goto failed_mount_wq;
4411 			}
4412 		}
4413 	}
4414 
4415 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4416 	    (blocksize != PAGE_SIZE)) {
4417 		ext4_msg(sb, KERN_ERR,
4418 			 "Unsupported blocksize for fs encryption");
4419 		goto failed_mount_wq;
4420 	}
4421 
4422 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4423 	    !ext4_has_feature_encrypt(sb)) {
4424 		ext4_set_feature_encrypt(sb);
4425 		ext4_commit_super(sb, 1);
4426 	}
4427 
4428 	/*
4429 	 * Get the # of file system overhead blocks from the
4430 	 * superblock if present.
4431 	 */
4432 	if (es->s_overhead_clusters)
4433 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4434 	else {
4435 		err = ext4_calculate_overhead(sb);
4436 		if (err)
4437 			goto failed_mount_wq;
4438 	}
4439 
4440 	/*
4441 	 * The maximum number of concurrent works can be high and
4442 	 * concurrency isn't really necessary.  Limit it to 1.
4443 	 */
4444 	EXT4_SB(sb)->rsv_conversion_wq =
4445 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4446 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4447 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4448 		ret = -ENOMEM;
4449 		goto failed_mount4;
4450 	}
4451 
4452 	/*
4453 	 * The jbd2_journal_load will have done any necessary log recovery,
4454 	 * so we can safely mount the rest of the filesystem now.
4455 	 */
4456 
4457 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4458 	if (IS_ERR(root)) {
4459 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4460 		ret = PTR_ERR(root);
4461 		root = NULL;
4462 		goto failed_mount4;
4463 	}
4464 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4465 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4466 		iput(root);
4467 		goto failed_mount4;
4468 	}
4469 
4470 #ifdef CONFIG_UNICODE
4471 	if (sbi->s_encoding)
4472 		sb->s_d_op = &ext4_dentry_ops;
4473 #endif
4474 
4475 	sb->s_root = d_make_root(root);
4476 	if (!sb->s_root) {
4477 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4478 		ret = -ENOMEM;
4479 		goto failed_mount4;
4480 	}
4481 
4482 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4483 	if (ret == -EROFS) {
4484 		sb->s_flags |= SB_RDONLY;
4485 		ret = 0;
4486 	} else if (ret)
4487 		goto failed_mount4a;
4488 
4489 	ext4_clamp_want_extra_isize(sb);
4490 
4491 	ext4_set_resv_clusters(sb);
4492 
4493 	err = ext4_setup_system_zone(sb);
4494 	if (err) {
4495 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4496 			 "zone (%d)", err);
4497 		goto failed_mount4a;
4498 	}
4499 
4500 	ext4_ext_init(sb);
4501 	err = ext4_mb_init(sb);
4502 	if (err) {
4503 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4504 			 err);
4505 		goto failed_mount5;
4506 	}
4507 
4508 	block = ext4_count_free_clusters(sb);
4509 	ext4_free_blocks_count_set(sbi->s_es,
4510 				   EXT4_C2B(sbi, block));
4511 	ext4_superblock_csum_set(sb);
4512 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4513 				  GFP_KERNEL);
4514 	if (!err) {
4515 		unsigned long freei = ext4_count_free_inodes(sb);
4516 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4517 		ext4_superblock_csum_set(sb);
4518 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4519 					  GFP_KERNEL);
4520 	}
4521 	if (!err)
4522 		err = percpu_counter_init(&sbi->s_dirs_counter,
4523 					  ext4_count_dirs(sb), GFP_KERNEL);
4524 	if (!err)
4525 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4526 					  GFP_KERNEL);
4527 	if (!err)
4528 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4529 
4530 	if (err) {
4531 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4532 		goto failed_mount6;
4533 	}
4534 
4535 	if (ext4_has_feature_flex_bg(sb))
4536 		if (!ext4_fill_flex_info(sb)) {
4537 			ext4_msg(sb, KERN_ERR,
4538 			       "unable to initialize "
4539 			       "flex_bg meta info!");
4540 			goto failed_mount6;
4541 		}
4542 
4543 	err = ext4_register_li_request(sb, first_not_zeroed);
4544 	if (err)
4545 		goto failed_mount6;
4546 
4547 	err = ext4_register_sysfs(sb);
4548 	if (err)
4549 		goto failed_mount7;
4550 
4551 #ifdef CONFIG_QUOTA
4552 	/* Enable quota usage during mount. */
4553 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4554 		err = ext4_enable_quotas(sb);
4555 		if (err)
4556 			goto failed_mount8;
4557 	}
4558 #endif  /* CONFIG_QUOTA */
4559 
4560 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4561 	ext4_orphan_cleanup(sb, es);
4562 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4563 	if (needs_recovery) {
4564 		ext4_msg(sb, KERN_INFO, "recovery complete");
4565 		ext4_mark_recovery_complete(sb, es);
4566 	}
4567 	if (EXT4_SB(sb)->s_journal) {
4568 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4569 			descr = " journalled data mode";
4570 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4571 			descr = " ordered data mode";
4572 		else
4573 			descr = " writeback data mode";
4574 	} else
4575 		descr = "out journal";
4576 
4577 	if (test_opt(sb, DISCARD)) {
4578 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4579 		if (!blk_queue_discard(q))
4580 			ext4_msg(sb, KERN_WARNING,
4581 				 "mounting with \"discard\" option, but "
4582 				 "the device does not support discard");
4583 	}
4584 
4585 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4586 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4587 			 "Opts: %.*s%s%s", descr,
4588 			 (int) sizeof(sbi->s_es->s_mount_opts),
4589 			 sbi->s_es->s_mount_opts,
4590 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4591 
4592 	if (es->s_error_count)
4593 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4594 
4595 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4596 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4597 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4598 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4599 
4600 	kfree(orig_data);
4601 	return 0;
4602 
4603 cantfind_ext4:
4604 	if (!silent)
4605 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4606 	goto failed_mount;
4607 
4608 #ifdef CONFIG_QUOTA
4609 failed_mount8:
4610 	ext4_unregister_sysfs(sb);
4611 #endif
4612 failed_mount7:
4613 	ext4_unregister_li_request(sb);
4614 failed_mount6:
4615 	ext4_mb_release(sb);
4616 	if (sbi->s_flex_groups)
4617 		kvfree(sbi->s_flex_groups);
4618 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4619 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4620 	percpu_counter_destroy(&sbi->s_dirs_counter);
4621 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4622 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
4623 failed_mount5:
4624 	ext4_ext_release(sb);
4625 	ext4_release_system_zone(sb);
4626 failed_mount4a:
4627 	dput(sb->s_root);
4628 	sb->s_root = NULL;
4629 failed_mount4:
4630 	ext4_msg(sb, KERN_ERR, "mount failed");
4631 	if (EXT4_SB(sb)->rsv_conversion_wq)
4632 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4633 failed_mount_wq:
4634 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4635 	sbi->s_ea_inode_cache = NULL;
4636 
4637 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4638 	sbi->s_ea_block_cache = NULL;
4639 
4640 	if (sbi->s_journal) {
4641 		jbd2_journal_destroy(sbi->s_journal);
4642 		sbi->s_journal = NULL;
4643 	}
4644 failed_mount3a:
4645 	ext4_es_unregister_shrinker(sbi);
4646 failed_mount3:
4647 	del_timer_sync(&sbi->s_err_report);
4648 	if (sbi->s_mmp_tsk)
4649 		kthread_stop(sbi->s_mmp_tsk);
4650 failed_mount2:
4651 	for (i = 0; i < db_count; i++)
4652 		brelse(sbi->s_group_desc[i]);
4653 	kvfree(sbi->s_group_desc);
4654 failed_mount:
4655 	if (sbi->s_chksum_driver)
4656 		crypto_free_shash(sbi->s_chksum_driver);
4657 
4658 #ifdef CONFIG_UNICODE
4659 	utf8_unload(sbi->s_encoding);
4660 #endif
4661 
4662 #ifdef CONFIG_QUOTA
4663 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4664 		kfree(get_qf_name(sb, sbi, i));
4665 #endif
4666 	ext4_blkdev_remove(sbi);
4667 	brelse(bh);
4668 out_fail:
4669 	sb->s_fs_info = NULL;
4670 	kfree(sbi->s_blockgroup_lock);
4671 out_free_base:
4672 	kfree(sbi);
4673 	kfree(orig_data);
4674 	fs_put_dax(dax_dev);
4675 	return err ? err : ret;
4676 }
4677 
4678 /*
4679  * Setup any per-fs journal parameters now.  We'll do this both on
4680  * initial mount, once the journal has been initialised but before we've
4681  * done any recovery; and again on any subsequent remount.
4682  */
4683 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4684 {
4685 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4686 
4687 	journal->j_commit_interval = sbi->s_commit_interval;
4688 	journal->j_min_batch_time = sbi->s_min_batch_time;
4689 	journal->j_max_batch_time = sbi->s_max_batch_time;
4690 
4691 	write_lock(&journal->j_state_lock);
4692 	if (test_opt(sb, BARRIER))
4693 		journal->j_flags |= JBD2_BARRIER;
4694 	else
4695 		journal->j_flags &= ~JBD2_BARRIER;
4696 	if (test_opt(sb, DATA_ERR_ABORT))
4697 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4698 	else
4699 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4700 	write_unlock(&journal->j_state_lock);
4701 }
4702 
4703 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4704 					     unsigned int journal_inum)
4705 {
4706 	struct inode *journal_inode;
4707 
4708 	/*
4709 	 * Test for the existence of a valid inode on disk.  Bad things
4710 	 * happen if we iget() an unused inode, as the subsequent iput()
4711 	 * will try to delete it.
4712 	 */
4713 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4714 	if (IS_ERR(journal_inode)) {
4715 		ext4_msg(sb, KERN_ERR, "no journal found");
4716 		return NULL;
4717 	}
4718 	if (!journal_inode->i_nlink) {
4719 		make_bad_inode(journal_inode);
4720 		iput(journal_inode);
4721 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4722 		return NULL;
4723 	}
4724 
4725 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4726 		  journal_inode, journal_inode->i_size);
4727 	if (!S_ISREG(journal_inode->i_mode)) {
4728 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4729 		iput(journal_inode);
4730 		return NULL;
4731 	}
4732 	return journal_inode;
4733 }
4734 
4735 static journal_t *ext4_get_journal(struct super_block *sb,
4736 				   unsigned int journal_inum)
4737 {
4738 	struct inode *journal_inode;
4739 	journal_t *journal;
4740 
4741 	BUG_ON(!ext4_has_feature_journal(sb));
4742 
4743 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4744 	if (!journal_inode)
4745 		return NULL;
4746 
4747 	journal = jbd2_journal_init_inode(journal_inode);
4748 	if (!journal) {
4749 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4750 		iput(journal_inode);
4751 		return NULL;
4752 	}
4753 	journal->j_private = sb;
4754 	ext4_init_journal_params(sb, journal);
4755 	return journal;
4756 }
4757 
4758 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4759 				       dev_t j_dev)
4760 {
4761 	struct buffer_head *bh;
4762 	journal_t *journal;
4763 	ext4_fsblk_t start;
4764 	ext4_fsblk_t len;
4765 	int hblock, blocksize;
4766 	ext4_fsblk_t sb_block;
4767 	unsigned long offset;
4768 	struct ext4_super_block *es;
4769 	struct block_device *bdev;
4770 
4771 	BUG_ON(!ext4_has_feature_journal(sb));
4772 
4773 	bdev = ext4_blkdev_get(j_dev, sb);
4774 	if (bdev == NULL)
4775 		return NULL;
4776 
4777 	blocksize = sb->s_blocksize;
4778 	hblock = bdev_logical_block_size(bdev);
4779 	if (blocksize < hblock) {
4780 		ext4_msg(sb, KERN_ERR,
4781 			"blocksize too small for journal device");
4782 		goto out_bdev;
4783 	}
4784 
4785 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4786 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4787 	set_blocksize(bdev, blocksize);
4788 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4789 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4790 		       "external journal");
4791 		goto out_bdev;
4792 	}
4793 
4794 	es = (struct ext4_super_block *) (bh->b_data + offset);
4795 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4796 	    !(le32_to_cpu(es->s_feature_incompat) &
4797 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4798 		ext4_msg(sb, KERN_ERR, "external journal has "
4799 					"bad superblock");
4800 		brelse(bh);
4801 		goto out_bdev;
4802 	}
4803 
4804 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4805 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4806 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4807 		ext4_msg(sb, KERN_ERR, "external journal has "
4808 				       "corrupt superblock");
4809 		brelse(bh);
4810 		goto out_bdev;
4811 	}
4812 
4813 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4814 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4815 		brelse(bh);
4816 		goto out_bdev;
4817 	}
4818 
4819 	len = ext4_blocks_count(es);
4820 	start = sb_block + 1;
4821 	brelse(bh);	/* we're done with the superblock */
4822 
4823 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4824 					start, len, blocksize);
4825 	if (!journal) {
4826 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4827 		goto out_bdev;
4828 	}
4829 	journal->j_private = sb;
4830 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4831 	wait_on_buffer(journal->j_sb_buffer);
4832 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4833 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4834 		goto out_journal;
4835 	}
4836 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4837 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4838 					"user (unsupported) - %d",
4839 			be32_to_cpu(journal->j_superblock->s_nr_users));
4840 		goto out_journal;
4841 	}
4842 	EXT4_SB(sb)->journal_bdev = bdev;
4843 	ext4_init_journal_params(sb, journal);
4844 	return journal;
4845 
4846 out_journal:
4847 	jbd2_journal_destroy(journal);
4848 out_bdev:
4849 	ext4_blkdev_put(bdev);
4850 	return NULL;
4851 }
4852 
4853 static int ext4_load_journal(struct super_block *sb,
4854 			     struct ext4_super_block *es,
4855 			     unsigned long journal_devnum)
4856 {
4857 	journal_t *journal;
4858 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4859 	dev_t journal_dev;
4860 	int err = 0;
4861 	int really_read_only;
4862 
4863 	BUG_ON(!ext4_has_feature_journal(sb));
4864 
4865 	if (journal_devnum &&
4866 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4867 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4868 			"numbers have changed");
4869 		journal_dev = new_decode_dev(journal_devnum);
4870 	} else
4871 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4872 
4873 	really_read_only = bdev_read_only(sb->s_bdev);
4874 
4875 	/*
4876 	 * Are we loading a blank journal or performing recovery after a
4877 	 * crash?  For recovery, we need to check in advance whether we
4878 	 * can get read-write access to the device.
4879 	 */
4880 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4881 		if (sb_rdonly(sb)) {
4882 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4883 					"required on readonly filesystem");
4884 			if (really_read_only) {
4885 				ext4_msg(sb, KERN_ERR, "write access "
4886 					"unavailable, cannot proceed "
4887 					"(try mounting with noload)");
4888 				return -EROFS;
4889 			}
4890 			ext4_msg(sb, KERN_INFO, "write access will "
4891 			       "be enabled during recovery");
4892 		}
4893 	}
4894 
4895 	if (journal_inum && journal_dev) {
4896 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4897 		       "and inode journals!");
4898 		return -EINVAL;
4899 	}
4900 
4901 	if (journal_inum) {
4902 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4903 			return -EINVAL;
4904 	} else {
4905 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4906 			return -EINVAL;
4907 	}
4908 
4909 	if (!(journal->j_flags & JBD2_BARRIER))
4910 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4911 
4912 	if (!ext4_has_feature_journal_needs_recovery(sb))
4913 		err = jbd2_journal_wipe(journal, !really_read_only);
4914 	if (!err) {
4915 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4916 		if (save)
4917 			memcpy(save, ((char *) es) +
4918 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4919 		err = jbd2_journal_load(journal);
4920 		if (save)
4921 			memcpy(((char *) es) + EXT4_S_ERR_START,
4922 			       save, EXT4_S_ERR_LEN);
4923 		kfree(save);
4924 	}
4925 
4926 	if (err) {
4927 		ext4_msg(sb, KERN_ERR, "error loading journal");
4928 		jbd2_journal_destroy(journal);
4929 		return err;
4930 	}
4931 
4932 	EXT4_SB(sb)->s_journal = journal;
4933 	ext4_clear_journal_err(sb, es);
4934 
4935 	if (!really_read_only && journal_devnum &&
4936 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4937 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4938 
4939 		/* Make sure we flush the recovery flag to disk. */
4940 		ext4_commit_super(sb, 1);
4941 	}
4942 
4943 	return 0;
4944 }
4945 
4946 static int ext4_commit_super(struct super_block *sb, int sync)
4947 {
4948 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4949 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4950 	int error = 0;
4951 
4952 	if (!sbh || block_device_ejected(sb))
4953 		return error;
4954 
4955 	/*
4956 	 * The superblock bh should be mapped, but it might not be if the
4957 	 * device was hot-removed. Not much we can do but fail the I/O.
4958 	 */
4959 	if (!buffer_mapped(sbh))
4960 		return error;
4961 
4962 	/*
4963 	 * If the file system is mounted read-only, don't update the
4964 	 * superblock write time.  This avoids updating the superblock
4965 	 * write time when we are mounting the root file system
4966 	 * read/only but we need to replay the journal; at that point,
4967 	 * for people who are east of GMT and who make their clock
4968 	 * tick in localtime for Windows bug-for-bug compatibility,
4969 	 * the clock is set in the future, and this will cause e2fsck
4970 	 * to complain and force a full file system check.
4971 	 */
4972 	if (!(sb->s_flags & SB_RDONLY))
4973 		ext4_update_tstamp(es, s_wtime);
4974 	if (sb->s_bdev->bd_part)
4975 		es->s_kbytes_written =
4976 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4977 			    ((part_stat_read(sb->s_bdev->bd_part,
4978 					     sectors[STAT_WRITE]) -
4979 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4980 	else
4981 		es->s_kbytes_written =
4982 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4983 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4984 		ext4_free_blocks_count_set(es,
4985 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4986 				&EXT4_SB(sb)->s_freeclusters_counter)));
4987 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4988 		es->s_free_inodes_count =
4989 			cpu_to_le32(percpu_counter_sum_positive(
4990 				&EXT4_SB(sb)->s_freeinodes_counter));
4991 	BUFFER_TRACE(sbh, "marking dirty");
4992 	ext4_superblock_csum_set(sb);
4993 	if (sync)
4994 		lock_buffer(sbh);
4995 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
4996 		/*
4997 		 * Oh, dear.  A previous attempt to write the
4998 		 * superblock failed.  This could happen because the
4999 		 * USB device was yanked out.  Or it could happen to
5000 		 * be a transient write error and maybe the block will
5001 		 * be remapped.  Nothing we can do but to retry the
5002 		 * write and hope for the best.
5003 		 */
5004 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5005 		       "superblock detected");
5006 		clear_buffer_write_io_error(sbh);
5007 		set_buffer_uptodate(sbh);
5008 	}
5009 	mark_buffer_dirty(sbh);
5010 	if (sync) {
5011 		unlock_buffer(sbh);
5012 		error = __sync_dirty_buffer(sbh,
5013 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5014 		if (buffer_write_io_error(sbh)) {
5015 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5016 			       "superblock");
5017 			clear_buffer_write_io_error(sbh);
5018 			set_buffer_uptodate(sbh);
5019 		}
5020 	}
5021 	return error;
5022 }
5023 
5024 /*
5025  * Have we just finished recovery?  If so, and if we are mounting (or
5026  * remounting) the filesystem readonly, then we will end up with a
5027  * consistent fs on disk.  Record that fact.
5028  */
5029 static void ext4_mark_recovery_complete(struct super_block *sb,
5030 					struct ext4_super_block *es)
5031 {
5032 	journal_t *journal = EXT4_SB(sb)->s_journal;
5033 
5034 	if (!ext4_has_feature_journal(sb)) {
5035 		BUG_ON(journal != NULL);
5036 		return;
5037 	}
5038 	jbd2_journal_lock_updates(journal);
5039 	if (jbd2_journal_flush(journal) < 0)
5040 		goto out;
5041 
5042 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5043 		ext4_clear_feature_journal_needs_recovery(sb);
5044 		ext4_commit_super(sb, 1);
5045 	}
5046 
5047 out:
5048 	jbd2_journal_unlock_updates(journal);
5049 }
5050 
5051 /*
5052  * If we are mounting (or read-write remounting) a filesystem whose journal
5053  * has recorded an error from a previous lifetime, move that error to the
5054  * main filesystem now.
5055  */
5056 static void ext4_clear_journal_err(struct super_block *sb,
5057 				   struct ext4_super_block *es)
5058 {
5059 	journal_t *journal;
5060 	int j_errno;
5061 	const char *errstr;
5062 
5063 	BUG_ON(!ext4_has_feature_journal(sb));
5064 
5065 	journal = EXT4_SB(sb)->s_journal;
5066 
5067 	/*
5068 	 * Now check for any error status which may have been recorded in the
5069 	 * journal by a prior ext4_error() or ext4_abort()
5070 	 */
5071 
5072 	j_errno = jbd2_journal_errno(journal);
5073 	if (j_errno) {
5074 		char nbuf[16];
5075 
5076 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5077 		ext4_warning(sb, "Filesystem error recorded "
5078 			     "from previous mount: %s", errstr);
5079 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5080 
5081 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5082 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5083 		ext4_commit_super(sb, 1);
5084 
5085 		jbd2_journal_clear_err(journal);
5086 		jbd2_journal_update_sb_errno(journal);
5087 	}
5088 }
5089 
5090 /*
5091  * Force the running and committing transactions to commit,
5092  * and wait on the commit.
5093  */
5094 int ext4_force_commit(struct super_block *sb)
5095 {
5096 	journal_t *journal;
5097 
5098 	if (sb_rdonly(sb))
5099 		return 0;
5100 
5101 	journal = EXT4_SB(sb)->s_journal;
5102 	return ext4_journal_force_commit(journal);
5103 }
5104 
5105 static int ext4_sync_fs(struct super_block *sb, int wait)
5106 {
5107 	int ret = 0;
5108 	tid_t target;
5109 	bool needs_barrier = false;
5110 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5111 
5112 	if (unlikely(ext4_forced_shutdown(sbi)))
5113 		return 0;
5114 
5115 	trace_ext4_sync_fs(sb, wait);
5116 	flush_workqueue(sbi->rsv_conversion_wq);
5117 	/*
5118 	 * Writeback quota in non-journalled quota case - journalled quota has
5119 	 * no dirty dquots
5120 	 */
5121 	dquot_writeback_dquots(sb, -1);
5122 	/*
5123 	 * Data writeback is possible w/o journal transaction, so barrier must
5124 	 * being sent at the end of the function. But we can skip it if
5125 	 * transaction_commit will do it for us.
5126 	 */
5127 	if (sbi->s_journal) {
5128 		target = jbd2_get_latest_transaction(sbi->s_journal);
5129 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5130 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5131 			needs_barrier = true;
5132 
5133 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5134 			if (wait)
5135 				ret = jbd2_log_wait_commit(sbi->s_journal,
5136 							   target);
5137 		}
5138 	} else if (wait && test_opt(sb, BARRIER))
5139 		needs_barrier = true;
5140 	if (needs_barrier) {
5141 		int err;
5142 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5143 		if (!ret)
5144 			ret = err;
5145 	}
5146 
5147 	return ret;
5148 }
5149 
5150 /*
5151  * LVM calls this function before a (read-only) snapshot is created.  This
5152  * gives us a chance to flush the journal completely and mark the fs clean.
5153  *
5154  * Note that only this function cannot bring a filesystem to be in a clean
5155  * state independently. It relies on upper layer to stop all data & metadata
5156  * modifications.
5157  */
5158 static int ext4_freeze(struct super_block *sb)
5159 {
5160 	int error = 0;
5161 	journal_t *journal;
5162 
5163 	if (sb_rdonly(sb))
5164 		return 0;
5165 
5166 	journal = EXT4_SB(sb)->s_journal;
5167 
5168 	if (journal) {
5169 		/* Now we set up the journal barrier. */
5170 		jbd2_journal_lock_updates(journal);
5171 
5172 		/*
5173 		 * Don't clear the needs_recovery flag if we failed to
5174 		 * flush the journal.
5175 		 */
5176 		error = jbd2_journal_flush(journal);
5177 		if (error < 0)
5178 			goto out;
5179 
5180 		/* Journal blocked and flushed, clear needs_recovery flag. */
5181 		ext4_clear_feature_journal_needs_recovery(sb);
5182 	}
5183 
5184 	error = ext4_commit_super(sb, 1);
5185 out:
5186 	if (journal)
5187 		/* we rely on upper layer to stop further updates */
5188 		jbd2_journal_unlock_updates(journal);
5189 	return error;
5190 }
5191 
5192 /*
5193  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5194  * flag here, even though the filesystem is not technically dirty yet.
5195  */
5196 static int ext4_unfreeze(struct super_block *sb)
5197 {
5198 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5199 		return 0;
5200 
5201 	if (EXT4_SB(sb)->s_journal) {
5202 		/* Reset the needs_recovery flag before the fs is unlocked. */
5203 		ext4_set_feature_journal_needs_recovery(sb);
5204 	}
5205 
5206 	ext4_commit_super(sb, 1);
5207 	return 0;
5208 }
5209 
5210 /*
5211  * Structure to save mount options for ext4_remount's benefit
5212  */
5213 struct ext4_mount_options {
5214 	unsigned long s_mount_opt;
5215 	unsigned long s_mount_opt2;
5216 	kuid_t s_resuid;
5217 	kgid_t s_resgid;
5218 	unsigned long s_commit_interval;
5219 	u32 s_min_batch_time, s_max_batch_time;
5220 #ifdef CONFIG_QUOTA
5221 	int s_jquota_fmt;
5222 	char *s_qf_names[EXT4_MAXQUOTAS];
5223 #endif
5224 };
5225 
5226 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5227 {
5228 	struct ext4_super_block *es;
5229 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5230 	unsigned long old_sb_flags;
5231 	struct ext4_mount_options old_opts;
5232 	int enable_quota = 0;
5233 	ext4_group_t g;
5234 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5235 	int err = 0;
5236 #ifdef CONFIG_QUOTA
5237 	int i, j;
5238 	char *to_free[EXT4_MAXQUOTAS];
5239 #endif
5240 	char *orig_data = kstrdup(data, GFP_KERNEL);
5241 
5242 	if (data && !orig_data)
5243 		return -ENOMEM;
5244 
5245 	/* Store the original options */
5246 	old_sb_flags = sb->s_flags;
5247 	old_opts.s_mount_opt = sbi->s_mount_opt;
5248 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5249 	old_opts.s_resuid = sbi->s_resuid;
5250 	old_opts.s_resgid = sbi->s_resgid;
5251 	old_opts.s_commit_interval = sbi->s_commit_interval;
5252 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5253 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5254 #ifdef CONFIG_QUOTA
5255 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5256 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5257 		if (sbi->s_qf_names[i]) {
5258 			char *qf_name = get_qf_name(sb, sbi, i);
5259 
5260 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5261 			if (!old_opts.s_qf_names[i]) {
5262 				for (j = 0; j < i; j++)
5263 					kfree(old_opts.s_qf_names[j]);
5264 				kfree(orig_data);
5265 				return -ENOMEM;
5266 			}
5267 		} else
5268 			old_opts.s_qf_names[i] = NULL;
5269 #endif
5270 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5271 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5272 
5273 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5274 		err = -EINVAL;
5275 		goto restore_opts;
5276 	}
5277 
5278 	ext4_clamp_want_extra_isize(sb);
5279 
5280 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5281 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5282 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5283 			 "during remount not supported; ignoring");
5284 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5285 	}
5286 
5287 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5288 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5289 			ext4_msg(sb, KERN_ERR, "can't mount with "
5290 				 "both data=journal and delalloc");
5291 			err = -EINVAL;
5292 			goto restore_opts;
5293 		}
5294 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5295 			ext4_msg(sb, KERN_ERR, "can't mount with "
5296 				 "both data=journal and dioread_nolock");
5297 			err = -EINVAL;
5298 			goto restore_opts;
5299 		}
5300 		if (test_opt(sb, DAX)) {
5301 			ext4_msg(sb, KERN_ERR, "can't mount with "
5302 				 "both data=journal and dax");
5303 			err = -EINVAL;
5304 			goto restore_opts;
5305 		}
5306 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5307 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5308 			ext4_msg(sb, KERN_ERR, "can't mount with "
5309 				"journal_async_commit in data=ordered mode");
5310 			err = -EINVAL;
5311 			goto restore_opts;
5312 		}
5313 	}
5314 
5315 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5316 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5317 		err = -EINVAL;
5318 		goto restore_opts;
5319 	}
5320 
5321 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5322 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5323 			"dax flag with busy inodes while remounting");
5324 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5325 	}
5326 
5327 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5328 		ext4_abort(sb, "Abort forced by user");
5329 
5330 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5331 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5332 
5333 	es = sbi->s_es;
5334 
5335 	if (sbi->s_journal) {
5336 		ext4_init_journal_params(sb, sbi->s_journal);
5337 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5338 	}
5339 
5340 	if (*flags & SB_LAZYTIME)
5341 		sb->s_flags |= SB_LAZYTIME;
5342 
5343 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5344 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5345 			err = -EROFS;
5346 			goto restore_opts;
5347 		}
5348 
5349 		if (*flags & SB_RDONLY) {
5350 			err = sync_filesystem(sb);
5351 			if (err < 0)
5352 				goto restore_opts;
5353 			err = dquot_suspend(sb, -1);
5354 			if (err < 0)
5355 				goto restore_opts;
5356 
5357 			/*
5358 			 * First of all, the unconditional stuff we have to do
5359 			 * to disable replay of the journal when we next remount
5360 			 */
5361 			sb->s_flags |= SB_RDONLY;
5362 
5363 			/*
5364 			 * OK, test if we are remounting a valid rw partition
5365 			 * readonly, and if so set the rdonly flag and then
5366 			 * mark the partition as valid again.
5367 			 */
5368 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5369 			    (sbi->s_mount_state & EXT4_VALID_FS))
5370 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5371 
5372 			if (sbi->s_journal)
5373 				ext4_mark_recovery_complete(sb, es);
5374 			if (sbi->s_mmp_tsk)
5375 				kthread_stop(sbi->s_mmp_tsk);
5376 		} else {
5377 			/* Make sure we can mount this feature set readwrite */
5378 			if (ext4_has_feature_readonly(sb) ||
5379 			    !ext4_feature_set_ok(sb, 0)) {
5380 				err = -EROFS;
5381 				goto restore_opts;
5382 			}
5383 			/*
5384 			 * Make sure the group descriptor checksums
5385 			 * are sane.  If they aren't, refuse to remount r/w.
5386 			 */
5387 			for (g = 0; g < sbi->s_groups_count; g++) {
5388 				struct ext4_group_desc *gdp =
5389 					ext4_get_group_desc(sb, g, NULL);
5390 
5391 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5392 					ext4_msg(sb, KERN_ERR,
5393 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5394 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5395 					       le16_to_cpu(gdp->bg_checksum));
5396 					err = -EFSBADCRC;
5397 					goto restore_opts;
5398 				}
5399 			}
5400 
5401 			/*
5402 			 * If we have an unprocessed orphan list hanging
5403 			 * around from a previously readonly bdev mount,
5404 			 * require a full umount/remount for now.
5405 			 */
5406 			if (es->s_last_orphan) {
5407 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5408 				       "remount RDWR because of unprocessed "
5409 				       "orphan inode list.  Please "
5410 				       "umount/remount instead");
5411 				err = -EINVAL;
5412 				goto restore_opts;
5413 			}
5414 
5415 			/*
5416 			 * Mounting a RDONLY partition read-write, so reread
5417 			 * and store the current valid flag.  (It may have
5418 			 * been changed by e2fsck since we originally mounted
5419 			 * the partition.)
5420 			 */
5421 			if (sbi->s_journal)
5422 				ext4_clear_journal_err(sb, es);
5423 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5424 
5425 			err = ext4_setup_super(sb, es, 0);
5426 			if (err)
5427 				goto restore_opts;
5428 
5429 			sb->s_flags &= ~SB_RDONLY;
5430 			if (ext4_has_feature_mmp(sb))
5431 				if (ext4_multi_mount_protect(sb,
5432 						le64_to_cpu(es->s_mmp_block))) {
5433 					err = -EROFS;
5434 					goto restore_opts;
5435 				}
5436 			enable_quota = 1;
5437 		}
5438 	}
5439 
5440 	/*
5441 	 * Reinitialize lazy itable initialization thread based on
5442 	 * current settings
5443 	 */
5444 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5445 		ext4_unregister_li_request(sb);
5446 	else {
5447 		ext4_group_t first_not_zeroed;
5448 		first_not_zeroed = ext4_has_uninit_itable(sb);
5449 		ext4_register_li_request(sb, first_not_zeroed);
5450 	}
5451 
5452 	ext4_setup_system_zone(sb);
5453 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5454 		err = ext4_commit_super(sb, 1);
5455 		if (err)
5456 			goto restore_opts;
5457 	}
5458 
5459 #ifdef CONFIG_QUOTA
5460 	/* Release old quota file names */
5461 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5462 		kfree(old_opts.s_qf_names[i]);
5463 	if (enable_quota) {
5464 		if (sb_any_quota_suspended(sb))
5465 			dquot_resume(sb, -1);
5466 		else if (ext4_has_feature_quota(sb)) {
5467 			err = ext4_enable_quotas(sb);
5468 			if (err)
5469 				goto restore_opts;
5470 		}
5471 	}
5472 #endif
5473 
5474 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5475 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5476 	kfree(orig_data);
5477 	return 0;
5478 
5479 restore_opts:
5480 	sb->s_flags = old_sb_flags;
5481 	sbi->s_mount_opt = old_opts.s_mount_opt;
5482 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5483 	sbi->s_resuid = old_opts.s_resuid;
5484 	sbi->s_resgid = old_opts.s_resgid;
5485 	sbi->s_commit_interval = old_opts.s_commit_interval;
5486 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5487 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5488 #ifdef CONFIG_QUOTA
5489 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5490 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5491 		to_free[i] = get_qf_name(sb, sbi, i);
5492 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5493 	}
5494 	synchronize_rcu();
5495 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5496 		kfree(to_free[i]);
5497 #endif
5498 	kfree(orig_data);
5499 	return err;
5500 }
5501 
5502 #ifdef CONFIG_QUOTA
5503 static int ext4_statfs_project(struct super_block *sb,
5504 			       kprojid_t projid, struct kstatfs *buf)
5505 {
5506 	struct kqid qid;
5507 	struct dquot *dquot;
5508 	u64 limit;
5509 	u64 curblock;
5510 
5511 	qid = make_kqid_projid(projid);
5512 	dquot = dqget(sb, qid);
5513 	if (IS_ERR(dquot))
5514 		return PTR_ERR(dquot);
5515 	spin_lock(&dquot->dq_dqb_lock);
5516 
5517 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5518 		 dquot->dq_dqb.dqb_bsoftlimit :
5519 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5520 	if (limit && buf->f_blocks > limit) {
5521 		curblock = (dquot->dq_dqb.dqb_curspace +
5522 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5523 		buf->f_blocks = limit;
5524 		buf->f_bfree = buf->f_bavail =
5525 			(buf->f_blocks > curblock) ?
5526 			 (buf->f_blocks - curblock) : 0;
5527 	}
5528 
5529 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5530 		dquot->dq_dqb.dqb_isoftlimit :
5531 		dquot->dq_dqb.dqb_ihardlimit;
5532 	if (limit && buf->f_files > limit) {
5533 		buf->f_files = limit;
5534 		buf->f_ffree =
5535 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5536 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5537 	}
5538 
5539 	spin_unlock(&dquot->dq_dqb_lock);
5540 	dqput(dquot);
5541 	return 0;
5542 }
5543 #endif
5544 
5545 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5546 {
5547 	struct super_block *sb = dentry->d_sb;
5548 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5549 	struct ext4_super_block *es = sbi->s_es;
5550 	ext4_fsblk_t overhead = 0, resv_blocks;
5551 	u64 fsid;
5552 	s64 bfree;
5553 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5554 
5555 	if (!test_opt(sb, MINIX_DF))
5556 		overhead = sbi->s_overhead;
5557 
5558 	buf->f_type = EXT4_SUPER_MAGIC;
5559 	buf->f_bsize = sb->s_blocksize;
5560 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5561 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5562 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5563 	/* prevent underflow in case that few free space is available */
5564 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5565 	buf->f_bavail = buf->f_bfree -
5566 			(ext4_r_blocks_count(es) + resv_blocks);
5567 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5568 		buf->f_bavail = 0;
5569 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5570 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5571 	buf->f_namelen = EXT4_NAME_LEN;
5572 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5573 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5574 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5575 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5576 
5577 #ifdef CONFIG_QUOTA
5578 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5579 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5580 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5581 #endif
5582 	return 0;
5583 }
5584 
5585 
5586 #ifdef CONFIG_QUOTA
5587 
5588 /*
5589  * Helper functions so that transaction is started before we acquire dqio_sem
5590  * to keep correct lock ordering of transaction > dqio_sem
5591  */
5592 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5593 {
5594 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5595 }
5596 
5597 static int ext4_write_dquot(struct dquot *dquot)
5598 {
5599 	int ret, err;
5600 	handle_t *handle;
5601 	struct inode *inode;
5602 
5603 	inode = dquot_to_inode(dquot);
5604 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5605 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5606 	if (IS_ERR(handle))
5607 		return PTR_ERR(handle);
5608 	ret = dquot_commit(dquot);
5609 	err = ext4_journal_stop(handle);
5610 	if (!ret)
5611 		ret = err;
5612 	return ret;
5613 }
5614 
5615 static int ext4_acquire_dquot(struct dquot *dquot)
5616 {
5617 	int ret, err;
5618 	handle_t *handle;
5619 
5620 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5621 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5622 	if (IS_ERR(handle))
5623 		return PTR_ERR(handle);
5624 	ret = dquot_acquire(dquot);
5625 	err = ext4_journal_stop(handle);
5626 	if (!ret)
5627 		ret = err;
5628 	return ret;
5629 }
5630 
5631 static int ext4_release_dquot(struct dquot *dquot)
5632 {
5633 	int ret, err;
5634 	handle_t *handle;
5635 
5636 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5637 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5638 	if (IS_ERR(handle)) {
5639 		/* Release dquot anyway to avoid endless cycle in dqput() */
5640 		dquot_release(dquot);
5641 		return PTR_ERR(handle);
5642 	}
5643 	ret = dquot_release(dquot);
5644 	err = ext4_journal_stop(handle);
5645 	if (!ret)
5646 		ret = err;
5647 	return ret;
5648 }
5649 
5650 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5651 {
5652 	struct super_block *sb = dquot->dq_sb;
5653 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5654 
5655 	/* Are we journaling quotas? */
5656 	if (ext4_has_feature_quota(sb) ||
5657 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5658 		dquot_mark_dquot_dirty(dquot);
5659 		return ext4_write_dquot(dquot);
5660 	} else {
5661 		return dquot_mark_dquot_dirty(dquot);
5662 	}
5663 }
5664 
5665 static int ext4_write_info(struct super_block *sb, int type)
5666 {
5667 	int ret, err;
5668 	handle_t *handle;
5669 
5670 	/* Data block + inode block */
5671 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5672 	if (IS_ERR(handle))
5673 		return PTR_ERR(handle);
5674 	ret = dquot_commit_info(sb, type);
5675 	err = ext4_journal_stop(handle);
5676 	if (!ret)
5677 		ret = err;
5678 	return ret;
5679 }
5680 
5681 /*
5682  * Turn on quotas during mount time - we need to find
5683  * the quota file and such...
5684  */
5685 static int ext4_quota_on_mount(struct super_block *sb, int type)
5686 {
5687 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5688 					EXT4_SB(sb)->s_jquota_fmt, type);
5689 }
5690 
5691 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5692 {
5693 	struct ext4_inode_info *ei = EXT4_I(inode);
5694 
5695 	/* The first argument of lockdep_set_subclass has to be
5696 	 * *exactly* the same as the argument to init_rwsem() --- in
5697 	 * this case, in init_once() --- or lockdep gets unhappy
5698 	 * because the name of the lock is set using the
5699 	 * stringification of the argument to init_rwsem().
5700 	 */
5701 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5702 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5703 }
5704 
5705 /*
5706  * Standard function to be called on quota_on
5707  */
5708 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5709 			 const struct path *path)
5710 {
5711 	int err;
5712 
5713 	if (!test_opt(sb, QUOTA))
5714 		return -EINVAL;
5715 
5716 	/* Quotafile not on the same filesystem? */
5717 	if (path->dentry->d_sb != sb)
5718 		return -EXDEV;
5719 	/* Journaling quota? */
5720 	if (EXT4_SB(sb)->s_qf_names[type]) {
5721 		/* Quotafile not in fs root? */
5722 		if (path->dentry->d_parent != sb->s_root)
5723 			ext4_msg(sb, KERN_WARNING,
5724 				"Quota file not on filesystem root. "
5725 				"Journaled quota will not work");
5726 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5727 	} else {
5728 		/*
5729 		 * Clear the flag just in case mount options changed since
5730 		 * last time.
5731 		 */
5732 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5733 	}
5734 
5735 	/*
5736 	 * When we journal data on quota file, we have to flush journal to see
5737 	 * all updates to the file when we bypass pagecache...
5738 	 */
5739 	if (EXT4_SB(sb)->s_journal &&
5740 	    ext4_should_journal_data(d_inode(path->dentry))) {
5741 		/*
5742 		 * We don't need to lock updates but journal_flush() could
5743 		 * otherwise be livelocked...
5744 		 */
5745 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5746 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5747 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5748 		if (err)
5749 			return err;
5750 	}
5751 
5752 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5753 	err = dquot_quota_on(sb, type, format_id, path);
5754 	if (err) {
5755 		lockdep_set_quota_inode(path->dentry->d_inode,
5756 					     I_DATA_SEM_NORMAL);
5757 	} else {
5758 		struct inode *inode = d_inode(path->dentry);
5759 		handle_t *handle;
5760 
5761 		/*
5762 		 * Set inode flags to prevent userspace from messing with quota
5763 		 * files. If this fails, we return success anyway since quotas
5764 		 * are already enabled and this is not a hard failure.
5765 		 */
5766 		inode_lock(inode);
5767 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5768 		if (IS_ERR(handle))
5769 			goto unlock_inode;
5770 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5771 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5772 				S_NOATIME | S_IMMUTABLE);
5773 		ext4_mark_inode_dirty(handle, inode);
5774 		ext4_journal_stop(handle);
5775 	unlock_inode:
5776 		inode_unlock(inode);
5777 	}
5778 	return err;
5779 }
5780 
5781 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5782 			     unsigned int flags)
5783 {
5784 	int err;
5785 	struct inode *qf_inode;
5786 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5787 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5788 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5789 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5790 	};
5791 
5792 	BUG_ON(!ext4_has_feature_quota(sb));
5793 
5794 	if (!qf_inums[type])
5795 		return -EPERM;
5796 
5797 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5798 	if (IS_ERR(qf_inode)) {
5799 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5800 		return PTR_ERR(qf_inode);
5801 	}
5802 
5803 	/* Don't account quota for quota files to avoid recursion */
5804 	qf_inode->i_flags |= S_NOQUOTA;
5805 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5806 	err = dquot_enable(qf_inode, type, format_id, flags);
5807 	if (err)
5808 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5809 	iput(qf_inode);
5810 
5811 	return err;
5812 }
5813 
5814 /* Enable usage tracking for all quota types. */
5815 static int ext4_enable_quotas(struct super_block *sb)
5816 {
5817 	int type, err = 0;
5818 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5819 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5820 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5821 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5822 	};
5823 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5824 		test_opt(sb, USRQUOTA),
5825 		test_opt(sb, GRPQUOTA),
5826 		test_opt(sb, PRJQUOTA),
5827 	};
5828 
5829 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5830 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5831 		if (qf_inums[type]) {
5832 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5833 				DQUOT_USAGE_ENABLED |
5834 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5835 			if (err) {
5836 				ext4_warning(sb,
5837 					"Failed to enable quota tracking "
5838 					"(type=%d, err=%d). Please run "
5839 					"e2fsck to fix.", type, err);
5840 				for (type--; type >= 0; type--)
5841 					dquot_quota_off(sb, type);
5842 
5843 				return err;
5844 			}
5845 		}
5846 	}
5847 	return 0;
5848 }
5849 
5850 static int ext4_quota_off(struct super_block *sb, int type)
5851 {
5852 	struct inode *inode = sb_dqopt(sb)->files[type];
5853 	handle_t *handle;
5854 	int err;
5855 
5856 	/* Force all delayed allocation blocks to be allocated.
5857 	 * Caller already holds s_umount sem */
5858 	if (test_opt(sb, DELALLOC))
5859 		sync_filesystem(sb);
5860 
5861 	if (!inode || !igrab(inode))
5862 		goto out;
5863 
5864 	err = dquot_quota_off(sb, type);
5865 	if (err || ext4_has_feature_quota(sb))
5866 		goto out_put;
5867 
5868 	inode_lock(inode);
5869 	/*
5870 	 * Update modification times of quota files when userspace can
5871 	 * start looking at them. If we fail, we return success anyway since
5872 	 * this is not a hard failure and quotas are already disabled.
5873 	 */
5874 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5875 	if (IS_ERR(handle))
5876 		goto out_unlock;
5877 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5878 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5879 	inode->i_mtime = inode->i_ctime = current_time(inode);
5880 	ext4_mark_inode_dirty(handle, inode);
5881 	ext4_journal_stop(handle);
5882 out_unlock:
5883 	inode_unlock(inode);
5884 out_put:
5885 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5886 	iput(inode);
5887 	return err;
5888 out:
5889 	return dquot_quota_off(sb, type);
5890 }
5891 
5892 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5893  * acquiring the locks... As quota files are never truncated and quota code
5894  * itself serializes the operations (and no one else should touch the files)
5895  * we don't have to be afraid of races */
5896 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5897 			       size_t len, loff_t off)
5898 {
5899 	struct inode *inode = sb_dqopt(sb)->files[type];
5900 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5901 	int offset = off & (sb->s_blocksize - 1);
5902 	int tocopy;
5903 	size_t toread;
5904 	struct buffer_head *bh;
5905 	loff_t i_size = i_size_read(inode);
5906 
5907 	if (off > i_size)
5908 		return 0;
5909 	if (off+len > i_size)
5910 		len = i_size-off;
5911 	toread = len;
5912 	while (toread > 0) {
5913 		tocopy = sb->s_blocksize - offset < toread ?
5914 				sb->s_blocksize - offset : toread;
5915 		bh = ext4_bread(NULL, inode, blk, 0);
5916 		if (IS_ERR(bh))
5917 			return PTR_ERR(bh);
5918 		if (!bh)	/* A hole? */
5919 			memset(data, 0, tocopy);
5920 		else
5921 			memcpy(data, bh->b_data+offset, tocopy);
5922 		brelse(bh);
5923 		offset = 0;
5924 		toread -= tocopy;
5925 		data += tocopy;
5926 		blk++;
5927 	}
5928 	return len;
5929 }
5930 
5931 /* Write to quotafile (we know the transaction is already started and has
5932  * enough credits) */
5933 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5934 				const char *data, size_t len, loff_t off)
5935 {
5936 	struct inode *inode = sb_dqopt(sb)->files[type];
5937 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5938 	int err, offset = off & (sb->s_blocksize - 1);
5939 	int retries = 0;
5940 	struct buffer_head *bh;
5941 	handle_t *handle = journal_current_handle();
5942 
5943 	if (EXT4_SB(sb)->s_journal && !handle) {
5944 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5945 			" cancelled because transaction is not started",
5946 			(unsigned long long)off, (unsigned long long)len);
5947 		return -EIO;
5948 	}
5949 	/*
5950 	 * Since we account only one data block in transaction credits,
5951 	 * then it is impossible to cross a block boundary.
5952 	 */
5953 	if (sb->s_blocksize - offset < len) {
5954 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5955 			" cancelled because not block aligned",
5956 			(unsigned long long)off, (unsigned long long)len);
5957 		return -EIO;
5958 	}
5959 
5960 	do {
5961 		bh = ext4_bread(handle, inode, blk,
5962 				EXT4_GET_BLOCKS_CREATE |
5963 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5964 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5965 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5966 	if (IS_ERR(bh))
5967 		return PTR_ERR(bh);
5968 	if (!bh)
5969 		goto out;
5970 	BUFFER_TRACE(bh, "get write access");
5971 	err = ext4_journal_get_write_access(handle, bh);
5972 	if (err) {
5973 		brelse(bh);
5974 		return err;
5975 	}
5976 	lock_buffer(bh);
5977 	memcpy(bh->b_data+offset, data, len);
5978 	flush_dcache_page(bh->b_page);
5979 	unlock_buffer(bh);
5980 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5981 	brelse(bh);
5982 out:
5983 	if (inode->i_size < off + len) {
5984 		i_size_write(inode, off + len);
5985 		EXT4_I(inode)->i_disksize = inode->i_size;
5986 		ext4_mark_inode_dirty(handle, inode);
5987 	}
5988 	return len;
5989 }
5990 
5991 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5992 {
5993 	const struct quota_format_ops	*ops;
5994 
5995 	if (!sb_has_quota_loaded(sb, qid->type))
5996 		return -ESRCH;
5997 	ops = sb_dqopt(sb)->ops[qid->type];
5998 	if (!ops || !ops->get_next_id)
5999 		return -ENOSYS;
6000 	return dquot_get_next_id(sb, qid);
6001 }
6002 #endif
6003 
6004 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6005 		       const char *dev_name, void *data)
6006 {
6007 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6008 }
6009 
6010 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6011 static inline void register_as_ext2(void)
6012 {
6013 	int err = register_filesystem(&ext2_fs_type);
6014 	if (err)
6015 		printk(KERN_WARNING
6016 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6017 }
6018 
6019 static inline void unregister_as_ext2(void)
6020 {
6021 	unregister_filesystem(&ext2_fs_type);
6022 }
6023 
6024 static inline int ext2_feature_set_ok(struct super_block *sb)
6025 {
6026 	if (ext4_has_unknown_ext2_incompat_features(sb))
6027 		return 0;
6028 	if (sb_rdonly(sb))
6029 		return 1;
6030 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6031 		return 0;
6032 	return 1;
6033 }
6034 #else
6035 static inline void register_as_ext2(void) { }
6036 static inline void unregister_as_ext2(void) { }
6037 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6038 #endif
6039 
6040 static inline void register_as_ext3(void)
6041 {
6042 	int err = register_filesystem(&ext3_fs_type);
6043 	if (err)
6044 		printk(KERN_WARNING
6045 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6046 }
6047 
6048 static inline void unregister_as_ext3(void)
6049 {
6050 	unregister_filesystem(&ext3_fs_type);
6051 }
6052 
6053 static inline int ext3_feature_set_ok(struct super_block *sb)
6054 {
6055 	if (ext4_has_unknown_ext3_incompat_features(sb))
6056 		return 0;
6057 	if (!ext4_has_feature_journal(sb))
6058 		return 0;
6059 	if (sb_rdonly(sb))
6060 		return 1;
6061 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6062 		return 0;
6063 	return 1;
6064 }
6065 
6066 static struct file_system_type ext4_fs_type = {
6067 	.owner		= THIS_MODULE,
6068 	.name		= "ext4",
6069 	.mount		= ext4_mount,
6070 	.kill_sb	= kill_block_super,
6071 	.fs_flags	= FS_REQUIRES_DEV,
6072 };
6073 MODULE_ALIAS_FS("ext4");
6074 
6075 /* Shared across all ext4 file systems */
6076 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6077 
6078 static int __init ext4_init_fs(void)
6079 {
6080 	int i, err;
6081 
6082 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6083 	ext4_li_info = NULL;
6084 	mutex_init(&ext4_li_mtx);
6085 
6086 	/* Build-time check for flags consistency */
6087 	ext4_check_flag_values();
6088 
6089 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6090 		init_waitqueue_head(&ext4__ioend_wq[i]);
6091 
6092 	err = ext4_init_es();
6093 	if (err)
6094 		return err;
6095 
6096 	err = ext4_init_pending();
6097 	if (err)
6098 		goto out6;
6099 
6100 	err = ext4_init_pageio();
6101 	if (err)
6102 		goto out5;
6103 
6104 	err = ext4_init_system_zone();
6105 	if (err)
6106 		goto out4;
6107 
6108 	err = ext4_init_sysfs();
6109 	if (err)
6110 		goto out3;
6111 
6112 	err = ext4_init_mballoc();
6113 	if (err)
6114 		goto out2;
6115 	err = init_inodecache();
6116 	if (err)
6117 		goto out1;
6118 	register_as_ext3();
6119 	register_as_ext2();
6120 	err = register_filesystem(&ext4_fs_type);
6121 	if (err)
6122 		goto out;
6123 
6124 	return 0;
6125 out:
6126 	unregister_as_ext2();
6127 	unregister_as_ext3();
6128 	destroy_inodecache();
6129 out1:
6130 	ext4_exit_mballoc();
6131 out2:
6132 	ext4_exit_sysfs();
6133 out3:
6134 	ext4_exit_system_zone();
6135 out4:
6136 	ext4_exit_pageio();
6137 out5:
6138 	ext4_exit_pending();
6139 out6:
6140 	ext4_exit_es();
6141 
6142 	return err;
6143 }
6144 
6145 static void __exit ext4_exit_fs(void)
6146 {
6147 	ext4_destroy_lazyinit_thread();
6148 	unregister_as_ext2();
6149 	unregister_as_ext3();
6150 	unregister_filesystem(&ext4_fs_type);
6151 	destroy_inodecache();
6152 	ext4_exit_mballoc();
6153 	ext4_exit_sysfs();
6154 	ext4_exit_system_zone();
6155 	ext4_exit_pageio();
6156 	ext4_exit_es();
6157 	ext4_exit_pending();
6158 }
6159 
6160 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6161 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6162 MODULE_LICENSE("GPL");
6163 MODULE_SOFTDEP("pre: crc32c");
6164 module_init(ext4_init_fs)
6165 module_exit(ext4_exit_fs)
6166