xref: /openbmc/linux/fs/ext4/super.c (revision 3e30a927)
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 (ext4_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 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
208 			       struct ext4_group_desc *bg)
209 {
210 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
211 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
212 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
213 }
214 
215 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
216 			       struct ext4_group_desc *bg)
217 {
218 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
219 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
220 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
221 }
222 
223 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
224 			      struct ext4_group_desc *bg)
225 {
226 	return le32_to_cpu(bg->bg_inode_table_lo) |
227 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
228 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
229 }
230 
231 __u32 ext4_free_group_clusters(struct super_block *sb,
232 			       struct ext4_group_desc *bg)
233 {
234 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
235 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
236 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
237 }
238 
239 __u32 ext4_free_inodes_count(struct super_block *sb,
240 			      struct ext4_group_desc *bg)
241 {
242 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
243 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
244 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
245 }
246 
247 __u32 ext4_used_dirs_count(struct super_block *sb,
248 			      struct ext4_group_desc *bg)
249 {
250 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
251 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
252 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
253 }
254 
255 __u32 ext4_itable_unused_count(struct super_block *sb,
256 			      struct ext4_group_desc *bg)
257 {
258 	return le16_to_cpu(bg->bg_itable_unused_lo) |
259 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
260 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
261 }
262 
263 void ext4_block_bitmap_set(struct super_block *sb,
264 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
265 {
266 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
267 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
268 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
269 }
270 
271 void ext4_inode_bitmap_set(struct super_block *sb,
272 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
273 {
274 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
275 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
276 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
277 }
278 
279 void ext4_inode_table_set(struct super_block *sb,
280 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
281 {
282 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
283 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
284 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
285 }
286 
287 void ext4_free_group_clusters_set(struct super_block *sb,
288 				  struct ext4_group_desc *bg, __u32 count)
289 {
290 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
291 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
292 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
293 }
294 
295 void ext4_free_inodes_set(struct super_block *sb,
296 			  struct ext4_group_desc *bg, __u32 count)
297 {
298 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
299 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
300 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
301 }
302 
303 void ext4_used_dirs_set(struct super_block *sb,
304 			  struct ext4_group_desc *bg, __u32 count)
305 {
306 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
307 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
308 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
309 }
310 
311 void ext4_itable_unused_set(struct super_block *sb,
312 			  struct ext4_group_desc *bg, __u32 count)
313 {
314 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
315 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
316 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
317 }
318 
319 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
320 {
321 	time64_t now = ktime_get_real_seconds();
322 
323 	now = clamp_val(now, 0, (1ull << 40) - 1);
324 
325 	*lo = cpu_to_le32(lower_32_bits(now));
326 	*hi = upper_32_bits(now);
327 }
328 
329 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
330 {
331 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
332 }
333 #define ext4_update_tstamp(es, tstamp) \
334 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
335 #define ext4_get_tstamp(es, tstamp) \
336 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
337 
338 static void __save_error_info(struct super_block *sb, const char *func,
339 			    unsigned int line)
340 {
341 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
342 
343 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
344 	if (bdev_read_only(sb->s_bdev))
345 		return;
346 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
347 	ext4_update_tstamp(es, s_last_error_time);
348 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
349 	es->s_last_error_line = cpu_to_le32(line);
350 	if (es->s_last_error_errcode == 0)
351 		es->s_last_error_errcode = EXT4_ERR_EFSCORRUPTED;
352 	if (!es->s_first_error_time) {
353 		es->s_first_error_time = es->s_last_error_time;
354 		es->s_first_error_time_hi = es->s_last_error_time_hi;
355 		strncpy(es->s_first_error_func, func,
356 			sizeof(es->s_first_error_func));
357 		es->s_first_error_line = cpu_to_le32(line);
358 		es->s_first_error_ino = es->s_last_error_ino;
359 		es->s_first_error_block = es->s_last_error_block;
360 		es->s_first_error_errcode = es->s_last_error_errcode;
361 	}
362 	/*
363 	 * Start the daily error reporting function if it hasn't been
364 	 * started already
365 	 */
366 	if (!es->s_error_count)
367 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
368 	le32_add_cpu(&es->s_error_count, 1);
369 }
370 
371 static void save_error_info(struct super_block *sb, const char *func,
372 			    unsigned int line)
373 {
374 	__save_error_info(sb, func, line);
375 	ext4_commit_super(sb, 1);
376 }
377 
378 /*
379  * The del_gendisk() function uninitializes the disk-specific data
380  * structures, including the bdi structure, without telling anyone
381  * else.  Once this happens, any attempt to call mark_buffer_dirty()
382  * (for example, by ext4_commit_super), will cause a kernel OOPS.
383  * This is a kludge to prevent these oops until we can put in a proper
384  * hook in del_gendisk() to inform the VFS and file system layers.
385  */
386 static int block_device_ejected(struct super_block *sb)
387 {
388 	struct inode *bd_inode = sb->s_bdev->bd_inode;
389 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
390 
391 	return bdi->dev == NULL;
392 }
393 
394 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
395 {
396 	struct super_block		*sb = journal->j_private;
397 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
398 	int				error = is_journal_aborted(journal);
399 	struct ext4_journal_cb_entry	*jce;
400 
401 	BUG_ON(txn->t_state == T_FINISHED);
402 
403 	ext4_process_freed_data(sb, txn->t_tid);
404 
405 	spin_lock(&sbi->s_md_lock);
406 	while (!list_empty(&txn->t_private_list)) {
407 		jce = list_entry(txn->t_private_list.next,
408 				 struct ext4_journal_cb_entry, jce_list);
409 		list_del_init(&jce->jce_list);
410 		spin_unlock(&sbi->s_md_lock);
411 		jce->jce_func(sb, jce, error);
412 		spin_lock(&sbi->s_md_lock);
413 	}
414 	spin_unlock(&sbi->s_md_lock);
415 }
416 
417 static bool system_going_down(void)
418 {
419 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
420 		|| system_state == SYSTEM_RESTART;
421 }
422 
423 /* Deal with the reporting of failure conditions on a filesystem such as
424  * inconsistencies detected or read IO failures.
425  *
426  * On ext2, we can store the error state of the filesystem in the
427  * superblock.  That is not possible on ext4, because we may have other
428  * write ordering constraints on the superblock which prevent us from
429  * writing it out straight away; and given that the journal is about to
430  * be aborted, we can't rely on the current, or future, transactions to
431  * write out the superblock safely.
432  *
433  * We'll just use the jbd2_journal_abort() error code to record an error in
434  * the journal instead.  On recovery, the journal will complain about
435  * that error until we've noted it down and cleared it.
436  */
437 
438 static void ext4_handle_error(struct super_block *sb)
439 {
440 	if (test_opt(sb, WARN_ON_ERROR))
441 		WARN_ON_ONCE(1);
442 
443 	if (sb_rdonly(sb))
444 		return;
445 
446 	if (!test_opt(sb, ERRORS_CONT)) {
447 		journal_t *journal = EXT4_SB(sb)->s_journal;
448 
449 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
450 		if (journal)
451 			jbd2_journal_abort(journal, -EIO);
452 	}
453 	/*
454 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
455 	 * could panic during 'reboot -f' as the underlying device got already
456 	 * disabled.
457 	 */
458 	if (test_opt(sb, ERRORS_RO) || system_going_down()) {
459 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
460 		/*
461 		 * Make sure updated value of ->s_mount_flags will be visible
462 		 * before ->s_flags update
463 		 */
464 		smp_wmb();
465 		sb->s_flags |= SB_RDONLY;
466 	} else if (test_opt(sb, ERRORS_PANIC)) {
467 		if (EXT4_SB(sb)->s_journal &&
468 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
469 			return;
470 		panic("EXT4-fs (device %s): panic forced after error\n",
471 			sb->s_id);
472 	}
473 }
474 
475 #define ext4_error_ratelimit(sb)					\
476 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
477 			     "EXT4-fs error")
478 
479 void __ext4_error(struct super_block *sb, const char *function,
480 		  unsigned int line, const char *fmt, ...)
481 {
482 	struct va_format vaf;
483 	va_list args;
484 
485 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
486 		return;
487 
488 	trace_ext4_error(sb, function, line);
489 	if (ext4_error_ratelimit(sb)) {
490 		va_start(args, fmt);
491 		vaf.fmt = fmt;
492 		vaf.va = &args;
493 		printk(KERN_CRIT
494 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
495 		       sb->s_id, function, line, current->comm, &vaf);
496 		va_end(args);
497 	}
498 	save_error_info(sb, function, line);
499 	ext4_handle_error(sb);
500 }
501 
502 void __ext4_error_inode(struct inode *inode, const char *function,
503 			unsigned int line, ext4_fsblk_t block,
504 			const char *fmt, ...)
505 {
506 	va_list args;
507 	struct va_format vaf;
508 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
509 
510 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
511 		return;
512 
513 	trace_ext4_error(inode->i_sb, function, line);
514 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
515 	es->s_last_error_block = cpu_to_le64(block);
516 	if (ext4_error_ratelimit(inode->i_sb)) {
517 		va_start(args, fmt);
518 		vaf.fmt = fmt;
519 		vaf.va = &args;
520 		if (block)
521 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
522 			       "inode #%lu: block %llu: comm %s: %pV\n",
523 			       inode->i_sb->s_id, function, line, inode->i_ino,
524 			       block, current->comm, &vaf);
525 		else
526 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
527 			       "inode #%lu: comm %s: %pV\n",
528 			       inode->i_sb->s_id, function, line, inode->i_ino,
529 			       current->comm, &vaf);
530 		va_end(args);
531 	}
532 	save_error_info(inode->i_sb, function, line);
533 	ext4_handle_error(inode->i_sb);
534 }
535 
536 void __ext4_error_file(struct file *file, const char *function,
537 		       unsigned int line, ext4_fsblk_t block,
538 		       const char *fmt, ...)
539 {
540 	va_list args;
541 	struct va_format vaf;
542 	struct ext4_super_block *es;
543 	struct inode *inode = file_inode(file);
544 	char pathname[80], *path;
545 
546 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
547 		return;
548 
549 	trace_ext4_error(inode->i_sb, function, line);
550 	es = EXT4_SB(inode->i_sb)->s_es;
551 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
552 	if (ext4_error_ratelimit(inode->i_sb)) {
553 		path = file_path(file, pathname, sizeof(pathname));
554 		if (IS_ERR(path))
555 			path = "(unknown)";
556 		va_start(args, fmt);
557 		vaf.fmt = fmt;
558 		vaf.va = &args;
559 		if (block)
560 			printk(KERN_CRIT
561 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
562 			       "block %llu: comm %s: path %s: %pV\n",
563 			       inode->i_sb->s_id, function, line, inode->i_ino,
564 			       block, current->comm, path, &vaf);
565 		else
566 			printk(KERN_CRIT
567 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
568 			       "comm %s: path %s: %pV\n",
569 			       inode->i_sb->s_id, function, line, inode->i_ino,
570 			       current->comm, path, &vaf);
571 		va_end(args);
572 	}
573 	save_error_info(inode->i_sb, function, line);
574 	ext4_handle_error(inode->i_sb);
575 }
576 
577 const char *ext4_decode_error(struct super_block *sb, int errno,
578 			      char nbuf[16])
579 {
580 	char *errstr = NULL;
581 
582 	switch (errno) {
583 	case -EFSCORRUPTED:
584 		errstr = "Corrupt filesystem";
585 		break;
586 	case -EFSBADCRC:
587 		errstr = "Filesystem failed CRC";
588 		break;
589 	case -EIO:
590 		errstr = "IO failure";
591 		break;
592 	case -ENOMEM:
593 		errstr = "Out of memory";
594 		break;
595 	case -EROFS:
596 		if (!sb || (EXT4_SB(sb)->s_journal &&
597 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
598 			errstr = "Journal has aborted";
599 		else
600 			errstr = "Readonly filesystem";
601 		break;
602 	default:
603 		/* If the caller passed in an extra buffer for unknown
604 		 * errors, textualise them now.  Else we just return
605 		 * NULL. */
606 		if (nbuf) {
607 			/* Check for truncated error codes... */
608 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
609 				errstr = nbuf;
610 		}
611 		break;
612 	}
613 
614 	return errstr;
615 }
616 
617 void ext4_set_errno(struct super_block *sb, int err)
618 {
619 	if (err < 0)
620 		err = -err;
621 
622 	switch (err) {
623 	case EIO:
624 		err = EXT4_ERR_EIO;
625 		break;
626 	case ENOMEM:
627 		err = EXT4_ERR_ENOMEM;
628 		break;
629 	case EFSBADCRC:
630 		err = EXT4_ERR_EFSBADCRC;
631 		break;
632 	case EFSCORRUPTED:
633 		err = EXT4_ERR_EFSCORRUPTED;
634 		break;
635 	case ENOSPC:
636 		err = EXT4_ERR_ENOSPC;
637 		break;
638 	case ENOKEY:
639 		err = EXT4_ERR_ENOKEY;
640 		break;
641 	case EROFS:
642 		err = EXT4_ERR_EROFS;
643 		break;
644 	case EFBIG:
645 		err = EXT4_ERR_EFBIG;
646 		break;
647 	case EEXIST:
648 		err = EXT4_ERR_EEXIST;
649 		break;
650 	case ERANGE:
651 		err = EXT4_ERR_ERANGE;
652 		break;
653 	case EOVERFLOW:
654 		err = EXT4_ERR_EOVERFLOW;
655 		break;
656 	case EBUSY:
657 		err = EXT4_ERR_EBUSY;
658 		break;
659 	case ENOTDIR:
660 		err = EXT4_ERR_ENOTDIR;
661 		break;
662 	case ENOTEMPTY:
663 		err = EXT4_ERR_ENOTEMPTY;
664 		break;
665 	case ESHUTDOWN:
666 		err = EXT4_ERR_ESHUTDOWN;
667 		break;
668 	case EFAULT:
669 		err = EXT4_ERR_EFAULT;
670 		break;
671 	default:
672 		err = EXT4_ERR_UNKNOWN;
673 	}
674 	EXT4_SB(sb)->s_es->s_last_error_errcode = err;
675 }
676 
677 /* __ext4_std_error decodes expected errors from journaling functions
678  * automatically and invokes the appropriate error response.  */
679 
680 void __ext4_std_error(struct super_block *sb, const char *function,
681 		      unsigned int line, int errno)
682 {
683 	char nbuf[16];
684 	const char *errstr;
685 
686 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
687 		return;
688 
689 	/* Special case: if the error is EROFS, and we're not already
690 	 * inside a transaction, then there's really no point in logging
691 	 * an error. */
692 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
693 		return;
694 
695 	if (ext4_error_ratelimit(sb)) {
696 		errstr = ext4_decode_error(sb, errno, nbuf);
697 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
698 		       sb->s_id, function, line, errstr);
699 	}
700 
701 	ext4_set_errno(sb, -errno);
702 	save_error_info(sb, function, line);
703 	ext4_handle_error(sb);
704 }
705 
706 /*
707  * ext4_abort is a much stronger failure handler than ext4_error.  The
708  * abort function may be used to deal with unrecoverable failures such
709  * as journal IO errors or ENOMEM at a critical moment in log management.
710  *
711  * We unconditionally force the filesystem into an ABORT|READONLY state,
712  * unless the error response on the fs has been set to panic in which
713  * case we take the easy way out and panic immediately.
714  */
715 
716 void __ext4_abort(struct super_block *sb, const char *function,
717 		unsigned int line, const char *fmt, ...)
718 {
719 	struct va_format vaf;
720 	va_list args;
721 
722 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
723 		return;
724 
725 	save_error_info(sb, function, line);
726 	va_start(args, fmt);
727 	vaf.fmt = fmt;
728 	vaf.va = &args;
729 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
730 	       sb->s_id, function, line, &vaf);
731 	va_end(args);
732 
733 	if (sb_rdonly(sb) == 0) {
734 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
735 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
736 		/*
737 		 * Make sure updated value of ->s_mount_flags will be visible
738 		 * before ->s_flags update
739 		 */
740 		smp_wmb();
741 		sb->s_flags |= SB_RDONLY;
742 		if (EXT4_SB(sb)->s_journal)
743 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
744 		save_error_info(sb, function, line);
745 	}
746 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
747 		if (EXT4_SB(sb)->s_journal &&
748 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
749 			return;
750 		panic("EXT4-fs panic from previous error\n");
751 	}
752 }
753 
754 void __ext4_msg(struct super_block *sb,
755 		const char *prefix, const char *fmt, ...)
756 {
757 	struct va_format vaf;
758 	va_list args;
759 
760 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
761 		return;
762 
763 	va_start(args, fmt);
764 	vaf.fmt = fmt;
765 	vaf.va = &args;
766 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
767 	va_end(args);
768 }
769 
770 #define ext4_warning_ratelimit(sb)					\
771 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
772 			     "EXT4-fs warning")
773 
774 void __ext4_warning(struct super_block *sb, const char *function,
775 		    unsigned int line, const char *fmt, ...)
776 {
777 	struct va_format vaf;
778 	va_list args;
779 
780 	if (!ext4_warning_ratelimit(sb))
781 		return;
782 
783 	va_start(args, fmt);
784 	vaf.fmt = fmt;
785 	vaf.va = &args;
786 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
787 	       sb->s_id, function, line, &vaf);
788 	va_end(args);
789 }
790 
791 void __ext4_warning_inode(const struct inode *inode, const char *function,
792 			  unsigned int line, const char *fmt, ...)
793 {
794 	struct va_format vaf;
795 	va_list args;
796 
797 	if (!ext4_warning_ratelimit(inode->i_sb))
798 		return;
799 
800 	va_start(args, fmt);
801 	vaf.fmt = fmt;
802 	vaf.va = &args;
803 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
804 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
805 	       function, line, inode->i_ino, current->comm, &vaf);
806 	va_end(args);
807 }
808 
809 void __ext4_grp_locked_error(const char *function, unsigned int line,
810 			     struct super_block *sb, ext4_group_t grp,
811 			     unsigned long ino, ext4_fsblk_t block,
812 			     const char *fmt, ...)
813 __releases(bitlock)
814 __acquires(bitlock)
815 {
816 	struct va_format vaf;
817 	va_list args;
818 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
819 
820 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
821 		return;
822 
823 	trace_ext4_error(sb, function, line);
824 	es->s_last_error_ino = cpu_to_le32(ino);
825 	es->s_last_error_block = cpu_to_le64(block);
826 	__save_error_info(sb, function, line);
827 
828 	if (ext4_error_ratelimit(sb)) {
829 		va_start(args, fmt);
830 		vaf.fmt = fmt;
831 		vaf.va = &args;
832 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
833 		       sb->s_id, function, line, grp);
834 		if (ino)
835 			printk(KERN_CONT "inode %lu: ", ino);
836 		if (block)
837 			printk(KERN_CONT "block %llu:",
838 			       (unsigned long long) block);
839 		printk(KERN_CONT "%pV\n", &vaf);
840 		va_end(args);
841 	}
842 
843 	if (test_opt(sb, WARN_ON_ERROR))
844 		WARN_ON_ONCE(1);
845 
846 	if (test_opt(sb, ERRORS_CONT)) {
847 		ext4_commit_super(sb, 0);
848 		return;
849 	}
850 
851 	ext4_unlock_group(sb, grp);
852 	ext4_commit_super(sb, 1);
853 	ext4_handle_error(sb);
854 	/*
855 	 * We only get here in the ERRORS_RO case; relocking the group
856 	 * may be dangerous, but nothing bad will happen since the
857 	 * filesystem will have already been marked read/only and the
858 	 * journal has been aborted.  We return 1 as a hint to callers
859 	 * who might what to use the return value from
860 	 * ext4_grp_locked_error() to distinguish between the
861 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
862 	 * aggressively from the ext4 function in question, with a
863 	 * more appropriate error code.
864 	 */
865 	ext4_lock_group(sb, grp);
866 	return;
867 }
868 
869 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
870 				     ext4_group_t group,
871 				     unsigned int flags)
872 {
873 	struct ext4_sb_info *sbi = EXT4_SB(sb);
874 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
875 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
876 	int ret;
877 
878 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
879 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
880 					    &grp->bb_state);
881 		if (!ret)
882 			percpu_counter_sub(&sbi->s_freeclusters_counter,
883 					   grp->bb_free);
884 	}
885 
886 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
887 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
888 					    &grp->bb_state);
889 		if (!ret && gdp) {
890 			int count;
891 
892 			count = ext4_free_inodes_count(sb, gdp);
893 			percpu_counter_sub(&sbi->s_freeinodes_counter,
894 					   count);
895 		}
896 	}
897 }
898 
899 void ext4_update_dynamic_rev(struct super_block *sb)
900 {
901 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
902 
903 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
904 		return;
905 
906 	ext4_warning(sb,
907 		     "updating to rev %d because of new feature flag, "
908 		     "running e2fsck is recommended",
909 		     EXT4_DYNAMIC_REV);
910 
911 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
912 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
913 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
914 	/* leave es->s_feature_*compat flags alone */
915 	/* es->s_uuid will be set by e2fsck if empty */
916 
917 	/*
918 	 * The rest of the superblock fields should be zero, and if not it
919 	 * means they are likely already in use, so leave them alone.  We
920 	 * can leave it up to e2fsck to clean up any inconsistencies there.
921 	 */
922 }
923 
924 /*
925  * Open the external journal device
926  */
927 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
928 {
929 	struct block_device *bdev;
930 	char b[BDEVNAME_SIZE];
931 
932 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
933 	if (IS_ERR(bdev))
934 		goto fail;
935 	return bdev;
936 
937 fail:
938 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
939 			__bdevname(dev, b), PTR_ERR(bdev));
940 	return NULL;
941 }
942 
943 /*
944  * Release the journal device
945  */
946 static void ext4_blkdev_put(struct block_device *bdev)
947 {
948 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
949 }
950 
951 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
952 {
953 	struct block_device *bdev;
954 	bdev = sbi->journal_bdev;
955 	if (bdev) {
956 		ext4_blkdev_put(bdev);
957 		sbi->journal_bdev = NULL;
958 	}
959 }
960 
961 static inline struct inode *orphan_list_entry(struct list_head *l)
962 {
963 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
964 }
965 
966 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
967 {
968 	struct list_head *l;
969 
970 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
971 		 le32_to_cpu(sbi->s_es->s_last_orphan));
972 
973 	printk(KERN_ERR "sb_info orphan list:\n");
974 	list_for_each(l, &sbi->s_orphan) {
975 		struct inode *inode = orphan_list_entry(l);
976 		printk(KERN_ERR "  "
977 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
978 		       inode->i_sb->s_id, inode->i_ino, inode,
979 		       inode->i_mode, inode->i_nlink,
980 		       NEXT_ORPHAN(inode));
981 	}
982 }
983 
984 #ifdef CONFIG_QUOTA
985 static int ext4_quota_off(struct super_block *sb, int type);
986 
987 static inline void ext4_quota_off_umount(struct super_block *sb)
988 {
989 	int type;
990 
991 	/* Use our quota_off function to clear inode flags etc. */
992 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
993 		ext4_quota_off(sb, type);
994 }
995 
996 /*
997  * This is a helper function which is used in the mount/remount
998  * codepaths (which holds s_umount) to fetch the quota file name.
999  */
1000 static inline char *get_qf_name(struct super_block *sb,
1001 				struct ext4_sb_info *sbi,
1002 				int type)
1003 {
1004 	return rcu_dereference_protected(sbi->s_qf_names[type],
1005 					 lockdep_is_held(&sb->s_umount));
1006 }
1007 #else
1008 static inline void ext4_quota_off_umount(struct super_block *sb)
1009 {
1010 }
1011 #endif
1012 
1013 static void ext4_put_super(struct super_block *sb)
1014 {
1015 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1016 	struct ext4_super_block *es = sbi->s_es;
1017 	int aborted = 0;
1018 	int i, err;
1019 
1020 	ext4_unregister_li_request(sb);
1021 	ext4_quota_off_umount(sb);
1022 
1023 	destroy_workqueue(sbi->rsv_conversion_wq);
1024 
1025 	if (sbi->s_journal) {
1026 		aborted = is_journal_aborted(sbi->s_journal);
1027 		err = jbd2_journal_destroy(sbi->s_journal);
1028 		sbi->s_journal = NULL;
1029 		if ((err < 0) && !aborted) {
1030 			ext4_set_errno(sb, -err);
1031 			ext4_abort(sb, "Couldn't clean up the journal");
1032 		}
1033 	}
1034 
1035 	ext4_unregister_sysfs(sb);
1036 	ext4_es_unregister_shrinker(sbi);
1037 	del_timer_sync(&sbi->s_err_report);
1038 	ext4_release_system_zone(sb);
1039 	ext4_mb_release(sb);
1040 	ext4_ext_release(sb);
1041 
1042 	if (!sb_rdonly(sb) && !aborted) {
1043 		ext4_clear_feature_journal_needs_recovery(sb);
1044 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1045 	}
1046 	if (!sb_rdonly(sb))
1047 		ext4_commit_super(sb, 1);
1048 
1049 	for (i = 0; i < sbi->s_gdb_count; i++)
1050 		brelse(sbi->s_group_desc[i]);
1051 	kvfree(sbi->s_group_desc);
1052 	kvfree(sbi->s_flex_groups);
1053 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1054 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1055 	percpu_counter_destroy(&sbi->s_dirs_counter);
1056 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1057 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
1058 #ifdef CONFIG_QUOTA
1059 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1060 		kfree(get_qf_name(sb, sbi, i));
1061 #endif
1062 
1063 	/* Debugging code just in case the in-memory inode orphan list
1064 	 * isn't empty.  The on-disk one can be non-empty if we've
1065 	 * detected an error and taken the fs readonly, but the
1066 	 * in-memory list had better be clean by this point. */
1067 	if (!list_empty(&sbi->s_orphan))
1068 		dump_orphan_list(sb, sbi);
1069 	J_ASSERT(list_empty(&sbi->s_orphan));
1070 
1071 	sync_blockdev(sb->s_bdev);
1072 	invalidate_bdev(sb->s_bdev);
1073 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
1074 		/*
1075 		 * Invalidate the journal device's buffers.  We don't want them
1076 		 * floating about in memory - the physical journal device may
1077 		 * hotswapped, and it breaks the `ro-after' testing code.
1078 		 */
1079 		sync_blockdev(sbi->journal_bdev);
1080 		invalidate_bdev(sbi->journal_bdev);
1081 		ext4_blkdev_remove(sbi);
1082 	}
1083 
1084 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1085 	sbi->s_ea_inode_cache = NULL;
1086 
1087 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1088 	sbi->s_ea_block_cache = NULL;
1089 
1090 	if (sbi->s_mmp_tsk)
1091 		kthread_stop(sbi->s_mmp_tsk);
1092 	brelse(sbi->s_sbh);
1093 	sb->s_fs_info = NULL;
1094 	/*
1095 	 * Now that we are completely done shutting down the
1096 	 * superblock, we need to actually destroy the kobject.
1097 	 */
1098 	kobject_put(&sbi->s_kobj);
1099 	wait_for_completion(&sbi->s_kobj_unregister);
1100 	if (sbi->s_chksum_driver)
1101 		crypto_free_shash(sbi->s_chksum_driver);
1102 	kfree(sbi->s_blockgroup_lock);
1103 	fs_put_dax(sbi->s_daxdev);
1104 #ifdef CONFIG_UNICODE
1105 	utf8_unload(sbi->s_encoding);
1106 #endif
1107 	kfree(sbi);
1108 }
1109 
1110 static struct kmem_cache *ext4_inode_cachep;
1111 
1112 /*
1113  * Called inside transaction, so use GFP_NOFS
1114  */
1115 static struct inode *ext4_alloc_inode(struct super_block *sb)
1116 {
1117 	struct ext4_inode_info *ei;
1118 
1119 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1120 	if (!ei)
1121 		return NULL;
1122 
1123 	inode_set_iversion(&ei->vfs_inode, 1);
1124 	spin_lock_init(&ei->i_raw_lock);
1125 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1126 	spin_lock_init(&ei->i_prealloc_lock);
1127 	ext4_es_init_tree(&ei->i_es_tree);
1128 	rwlock_init(&ei->i_es_lock);
1129 	INIT_LIST_HEAD(&ei->i_es_list);
1130 	ei->i_es_all_nr = 0;
1131 	ei->i_es_shk_nr = 0;
1132 	ei->i_es_shrink_lblk = 0;
1133 	ei->i_reserved_data_blocks = 0;
1134 	spin_lock_init(&(ei->i_block_reservation_lock));
1135 	ext4_init_pending_tree(&ei->i_pending_tree);
1136 #ifdef CONFIG_QUOTA
1137 	ei->i_reserved_quota = 0;
1138 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1139 #endif
1140 	ei->jinode = NULL;
1141 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1142 	spin_lock_init(&ei->i_completed_io_lock);
1143 	ei->i_sync_tid = 0;
1144 	ei->i_datasync_tid = 0;
1145 	atomic_set(&ei->i_unwritten, 0);
1146 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1147 	return &ei->vfs_inode;
1148 }
1149 
1150 static int ext4_drop_inode(struct inode *inode)
1151 {
1152 	int drop = generic_drop_inode(inode);
1153 
1154 	if (!drop)
1155 		drop = fscrypt_drop_inode(inode);
1156 
1157 	trace_ext4_drop_inode(inode, drop);
1158 	return drop;
1159 }
1160 
1161 static void ext4_free_in_core_inode(struct inode *inode)
1162 {
1163 	fscrypt_free_inode(inode);
1164 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1165 }
1166 
1167 static void ext4_destroy_inode(struct inode *inode)
1168 {
1169 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1170 		ext4_msg(inode->i_sb, KERN_ERR,
1171 			 "Inode %lu (%p): orphan list check failed!",
1172 			 inode->i_ino, EXT4_I(inode));
1173 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1174 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1175 				true);
1176 		dump_stack();
1177 	}
1178 }
1179 
1180 static void init_once(void *foo)
1181 {
1182 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1183 
1184 	INIT_LIST_HEAD(&ei->i_orphan);
1185 	init_rwsem(&ei->xattr_sem);
1186 	init_rwsem(&ei->i_data_sem);
1187 	init_rwsem(&ei->i_mmap_sem);
1188 	inode_init_once(&ei->vfs_inode);
1189 }
1190 
1191 static int __init init_inodecache(void)
1192 {
1193 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1194 				sizeof(struct ext4_inode_info), 0,
1195 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1196 					SLAB_ACCOUNT),
1197 				offsetof(struct ext4_inode_info, i_data),
1198 				sizeof_field(struct ext4_inode_info, i_data),
1199 				init_once);
1200 	if (ext4_inode_cachep == NULL)
1201 		return -ENOMEM;
1202 	return 0;
1203 }
1204 
1205 static void destroy_inodecache(void)
1206 {
1207 	/*
1208 	 * Make sure all delayed rcu free inodes are flushed before we
1209 	 * destroy cache.
1210 	 */
1211 	rcu_barrier();
1212 	kmem_cache_destroy(ext4_inode_cachep);
1213 }
1214 
1215 void ext4_clear_inode(struct inode *inode)
1216 {
1217 	invalidate_inode_buffers(inode);
1218 	clear_inode(inode);
1219 	ext4_discard_preallocations(inode);
1220 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1221 	dquot_drop(inode);
1222 	if (EXT4_I(inode)->jinode) {
1223 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1224 					       EXT4_I(inode)->jinode);
1225 		jbd2_free_inode(EXT4_I(inode)->jinode);
1226 		EXT4_I(inode)->jinode = NULL;
1227 	}
1228 	fscrypt_put_encryption_info(inode);
1229 	fsverity_cleanup_inode(inode);
1230 }
1231 
1232 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1233 					u64 ino, u32 generation)
1234 {
1235 	struct inode *inode;
1236 
1237 	/*
1238 	 * Currently we don't know the generation for parent directory, so
1239 	 * a generation of 0 means "accept any"
1240 	 */
1241 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1242 	if (IS_ERR(inode))
1243 		return ERR_CAST(inode);
1244 	if (generation && inode->i_generation != generation) {
1245 		iput(inode);
1246 		return ERR_PTR(-ESTALE);
1247 	}
1248 
1249 	return inode;
1250 }
1251 
1252 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1253 					int fh_len, int fh_type)
1254 {
1255 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1256 				    ext4_nfs_get_inode);
1257 }
1258 
1259 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1260 					int fh_len, int fh_type)
1261 {
1262 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1263 				    ext4_nfs_get_inode);
1264 }
1265 
1266 static int ext4_nfs_commit_metadata(struct inode *inode)
1267 {
1268 	struct writeback_control wbc = {
1269 		.sync_mode = WB_SYNC_ALL
1270 	};
1271 
1272 	trace_ext4_nfs_commit_metadata(inode);
1273 	return ext4_write_inode(inode, &wbc);
1274 }
1275 
1276 /*
1277  * Try to release metadata pages (indirect blocks, directories) which are
1278  * mapped via the block device.  Since these pages could have journal heads
1279  * which would prevent try_to_free_buffers() from freeing them, we must use
1280  * jbd2 layer's try_to_free_buffers() function to release them.
1281  */
1282 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1283 				 gfp_t wait)
1284 {
1285 	journal_t *journal = EXT4_SB(sb)->s_journal;
1286 
1287 	WARN_ON(PageChecked(page));
1288 	if (!page_has_buffers(page))
1289 		return 0;
1290 	if (journal)
1291 		return jbd2_journal_try_to_free_buffers(journal, page,
1292 						wait & ~__GFP_DIRECT_RECLAIM);
1293 	return try_to_free_buffers(page);
1294 }
1295 
1296 #ifdef CONFIG_FS_ENCRYPTION
1297 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1298 {
1299 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1300 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1301 }
1302 
1303 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1304 							void *fs_data)
1305 {
1306 	handle_t *handle = fs_data;
1307 	int res, res2, credits, retries = 0;
1308 
1309 	/*
1310 	 * Encrypting the root directory is not allowed because e2fsck expects
1311 	 * lost+found to exist and be unencrypted, and encrypting the root
1312 	 * directory would imply encrypting the lost+found directory as well as
1313 	 * the filename "lost+found" itself.
1314 	 */
1315 	if (inode->i_ino == EXT4_ROOT_INO)
1316 		return -EPERM;
1317 
1318 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1319 		return -EINVAL;
1320 
1321 	res = ext4_convert_inline_data(inode);
1322 	if (res)
1323 		return res;
1324 
1325 	/*
1326 	 * If a journal handle was specified, then the encryption context is
1327 	 * being set on a new inode via inheritance and is part of a larger
1328 	 * transaction to create the inode.  Otherwise the encryption context is
1329 	 * being set on an existing inode in its own transaction.  Only in the
1330 	 * latter case should the "retry on ENOSPC" logic be used.
1331 	 */
1332 
1333 	if (handle) {
1334 		res = ext4_xattr_set_handle(handle, inode,
1335 					    EXT4_XATTR_INDEX_ENCRYPTION,
1336 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1337 					    ctx, len, 0);
1338 		if (!res) {
1339 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1340 			ext4_clear_inode_state(inode,
1341 					EXT4_STATE_MAY_INLINE_DATA);
1342 			/*
1343 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1344 			 * S_DAX may be disabled
1345 			 */
1346 			ext4_set_inode_flags(inode);
1347 		}
1348 		return res;
1349 	}
1350 
1351 	res = dquot_initialize(inode);
1352 	if (res)
1353 		return res;
1354 retry:
1355 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1356 				     &credits);
1357 	if (res)
1358 		return res;
1359 
1360 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1361 	if (IS_ERR(handle))
1362 		return PTR_ERR(handle);
1363 
1364 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1365 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1366 				    ctx, len, 0);
1367 	if (!res) {
1368 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1369 		/*
1370 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1371 		 * S_DAX may be disabled
1372 		 */
1373 		ext4_set_inode_flags(inode);
1374 		res = ext4_mark_inode_dirty(handle, inode);
1375 		if (res)
1376 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1377 	}
1378 	res2 = ext4_journal_stop(handle);
1379 
1380 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1381 		goto retry;
1382 	if (!res)
1383 		res = res2;
1384 	return res;
1385 }
1386 
1387 static bool ext4_dummy_context(struct inode *inode)
1388 {
1389 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1390 }
1391 
1392 static bool ext4_has_stable_inodes(struct super_block *sb)
1393 {
1394 	return ext4_has_feature_stable_inodes(sb);
1395 }
1396 
1397 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1398 				       int *ino_bits_ret, int *lblk_bits_ret)
1399 {
1400 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1401 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1402 }
1403 
1404 static const struct fscrypt_operations ext4_cryptops = {
1405 	.key_prefix		= "ext4:",
1406 	.get_context		= ext4_get_context,
1407 	.set_context		= ext4_set_context,
1408 	.dummy_context		= ext4_dummy_context,
1409 	.empty_dir		= ext4_empty_dir,
1410 	.max_namelen		= EXT4_NAME_LEN,
1411 	.has_stable_inodes	= ext4_has_stable_inodes,
1412 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1413 };
1414 #endif
1415 
1416 #ifdef CONFIG_QUOTA
1417 static const char * const quotatypes[] = INITQFNAMES;
1418 #define QTYPE2NAME(t) (quotatypes[t])
1419 
1420 static int ext4_write_dquot(struct dquot *dquot);
1421 static int ext4_acquire_dquot(struct dquot *dquot);
1422 static int ext4_release_dquot(struct dquot *dquot);
1423 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1424 static int ext4_write_info(struct super_block *sb, int type);
1425 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1426 			 const struct path *path);
1427 static int ext4_quota_on_mount(struct super_block *sb, int type);
1428 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1429 			       size_t len, loff_t off);
1430 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1431 				const char *data, size_t len, loff_t off);
1432 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1433 			     unsigned int flags);
1434 static int ext4_enable_quotas(struct super_block *sb);
1435 
1436 static struct dquot **ext4_get_dquots(struct inode *inode)
1437 {
1438 	return EXT4_I(inode)->i_dquot;
1439 }
1440 
1441 static const struct dquot_operations ext4_quota_operations = {
1442 	.get_reserved_space	= ext4_get_reserved_space,
1443 	.write_dquot		= ext4_write_dquot,
1444 	.acquire_dquot		= ext4_acquire_dquot,
1445 	.release_dquot		= ext4_release_dquot,
1446 	.mark_dirty		= ext4_mark_dquot_dirty,
1447 	.write_info		= ext4_write_info,
1448 	.alloc_dquot		= dquot_alloc,
1449 	.destroy_dquot		= dquot_destroy,
1450 	.get_projid		= ext4_get_projid,
1451 	.get_inode_usage	= ext4_get_inode_usage,
1452 	.get_next_id		= dquot_get_next_id,
1453 };
1454 
1455 static const struct quotactl_ops ext4_qctl_operations = {
1456 	.quota_on	= ext4_quota_on,
1457 	.quota_off	= ext4_quota_off,
1458 	.quota_sync	= dquot_quota_sync,
1459 	.get_state	= dquot_get_state,
1460 	.set_info	= dquot_set_dqinfo,
1461 	.get_dqblk	= dquot_get_dqblk,
1462 	.set_dqblk	= dquot_set_dqblk,
1463 	.get_nextdqblk	= dquot_get_next_dqblk,
1464 };
1465 #endif
1466 
1467 static const struct super_operations ext4_sops = {
1468 	.alloc_inode	= ext4_alloc_inode,
1469 	.free_inode	= ext4_free_in_core_inode,
1470 	.destroy_inode	= ext4_destroy_inode,
1471 	.write_inode	= ext4_write_inode,
1472 	.dirty_inode	= ext4_dirty_inode,
1473 	.drop_inode	= ext4_drop_inode,
1474 	.evict_inode	= ext4_evict_inode,
1475 	.put_super	= ext4_put_super,
1476 	.sync_fs	= ext4_sync_fs,
1477 	.freeze_fs	= ext4_freeze,
1478 	.unfreeze_fs	= ext4_unfreeze,
1479 	.statfs		= ext4_statfs,
1480 	.remount_fs	= ext4_remount,
1481 	.show_options	= ext4_show_options,
1482 #ifdef CONFIG_QUOTA
1483 	.quota_read	= ext4_quota_read,
1484 	.quota_write	= ext4_quota_write,
1485 	.get_dquots	= ext4_get_dquots,
1486 #endif
1487 	.bdev_try_to_free_page = bdev_try_to_free_page,
1488 };
1489 
1490 static const struct export_operations ext4_export_ops = {
1491 	.fh_to_dentry = ext4_fh_to_dentry,
1492 	.fh_to_parent = ext4_fh_to_parent,
1493 	.get_parent = ext4_get_parent,
1494 	.commit_metadata = ext4_nfs_commit_metadata,
1495 };
1496 
1497 enum {
1498 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1499 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1500 	Opt_nouid32, Opt_debug, Opt_removed,
1501 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1502 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1503 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1504 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1505 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1506 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1507 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1508 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1509 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1510 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1511 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1512 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1513 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1514 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1515 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1516 	Opt_dioread_nolock, Opt_dioread_lock,
1517 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1518 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1519 };
1520 
1521 static const match_table_t tokens = {
1522 	{Opt_bsd_df, "bsddf"},
1523 	{Opt_minix_df, "minixdf"},
1524 	{Opt_grpid, "grpid"},
1525 	{Opt_grpid, "bsdgroups"},
1526 	{Opt_nogrpid, "nogrpid"},
1527 	{Opt_nogrpid, "sysvgroups"},
1528 	{Opt_resgid, "resgid=%u"},
1529 	{Opt_resuid, "resuid=%u"},
1530 	{Opt_sb, "sb=%u"},
1531 	{Opt_err_cont, "errors=continue"},
1532 	{Opt_err_panic, "errors=panic"},
1533 	{Opt_err_ro, "errors=remount-ro"},
1534 	{Opt_nouid32, "nouid32"},
1535 	{Opt_debug, "debug"},
1536 	{Opt_removed, "oldalloc"},
1537 	{Opt_removed, "orlov"},
1538 	{Opt_user_xattr, "user_xattr"},
1539 	{Opt_nouser_xattr, "nouser_xattr"},
1540 	{Opt_acl, "acl"},
1541 	{Opt_noacl, "noacl"},
1542 	{Opt_noload, "norecovery"},
1543 	{Opt_noload, "noload"},
1544 	{Opt_removed, "nobh"},
1545 	{Opt_removed, "bh"},
1546 	{Opt_commit, "commit=%u"},
1547 	{Opt_min_batch_time, "min_batch_time=%u"},
1548 	{Opt_max_batch_time, "max_batch_time=%u"},
1549 	{Opt_journal_dev, "journal_dev=%u"},
1550 	{Opt_journal_path, "journal_path=%s"},
1551 	{Opt_journal_checksum, "journal_checksum"},
1552 	{Opt_nojournal_checksum, "nojournal_checksum"},
1553 	{Opt_journal_async_commit, "journal_async_commit"},
1554 	{Opt_abort, "abort"},
1555 	{Opt_data_journal, "data=journal"},
1556 	{Opt_data_ordered, "data=ordered"},
1557 	{Opt_data_writeback, "data=writeback"},
1558 	{Opt_data_err_abort, "data_err=abort"},
1559 	{Opt_data_err_ignore, "data_err=ignore"},
1560 	{Opt_offusrjquota, "usrjquota="},
1561 	{Opt_usrjquota, "usrjquota=%s"},
1562 	{Opt_offgrpjquota, "grpjquota="},
1563 	{Opt_grpjquota, "grpjquota=%s"},
1564 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1565 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1566 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1567 	{Opt_grpquota, "grpquota"},
1568 	{Opt_noquota, "noquota"},
1569 	{Opt_quota, "quota"},
1570 	{Opt_usrquota, "usrquota"},
1571 	{Opt_prjquota, "prjquota"},
1572 	{Opt_barrier, "barrier=%u"},
1573 	{Opt_barrier, "barrier"},
1574 	{Opt_nobarrier, "nobarrier"},
1575 	{Opt_i_version, "i_version"},
1576 	{Opt_dax, "dax"},
1577 	{Opt_stripe, "stripe=%u"},
1578 	{Opt_delalloc, "delalloc"},
1579 	{Opt_warn_on_error, "warn_on_error"},
1580 	{Opt_nowarn_on_error, "nowarn_on_error"},
1581 	{Opt_lazytime, "lazytime"},
1582 	{Opt_nolazytime, "nolazytime"},
1583 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1584 	{Opt_nodelalloc, "nodelalloc"},
1585 	{Opt_removed, "mblk_io_submit"},
1586 	{Opt_removed, "nomblk_io_submit"},
1587 	{Opt_block_validity, "block_validity"},
1588 	{Opt_noblock_validity, "noblock_validity"},
1589 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1590 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1591 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1592 	{Opt_auto_da_alloc, "auto_da_alloc"},
1593 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1594 	{Opt_dioread_nolock, "dioread_nolock"},
1595 	{Opt_dioread_lock, "nodioread_nolock"},
1596 	{Opt_dioread_lock, "dioread_lock"},
1597 	{Opt_discard, "discard"},
1598 	{Opt_nodiscard, "nodiscard"},
1599 	{Opt_init_itable, "init_itable=%u"},
1600 	{Opt_init_itable, "init_itable"},
1601 	{Opt_noinit_itable, "noinit_itable"},
1602 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1603 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1604 	{Opt_nombcache, "nombcache"},
1605 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1606 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1607 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1608 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1609 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1610 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1611 	{Opt_err, NULL},
1612 };
1613 
1614 static ext4_fsblk_t get_sb_block(void **data)
1615 {
1616 	ext4_fsblk_t	sb_block;
1617 	char		*options = (char *) *data;
1618 
1619 	if (!options || strncmp(options, "sb=", 3) != 0)
1620 		return 1;	/* Default location */
1621 
1622 	options += 3;
1623 	/* TODO: use simple_strtoll with >32bit ext4 */
1624 	sb_block = simple_strtoul(options, &options, 0);
1625 	if (*options && *options != ',') {
1626 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1627 		       (char *) *data);
1628 		return 1;
1629 	}
1630 	if (*options == ',')
1631 		options++;
1632 	*data = (void *) options;
1633 
1634 	return sb_block;
1635 }
1636 
1637 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1638 static const char deprecated_msg[] =
1639 	"Mount option \"%s\" will be removed by %s\n"
1640 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1641 
1642 #ifdef CONFIG_QUOTA
1643 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1644 {
1645 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1646 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1647 	int ret = -1;
1648 
1649 	if (sb_any_quota_loaded(sb) && !old_qname) {
1650 		ext4_msg(sb, KERN_ERR,
1651 			"Cannot change journaled "
1652 			"quota options when quota turned on");
1653 		return -1;
1654 	}
1655 	if (ext4_has_feature_quota(sb)) {
1656 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1657 			 "ignored when QUOTA feature is enabled");
1658 		return 1;
1659 	}
1660 	qname = match_strdup(args);
1661 	if (!qname) {
1662 		ext4_msg(sb, KERN_ERR,
1663 			"Not enough memory for storing quotafile name");
1664 		return -1;
1665 	}
1666 	if (old_qname) {
1667 		if (strcmp(old_qname, qname) == 0)
1668 			ret = 1;
1669 		else
1670 			ext4_msg(sb, KERN_ERR,
1671 				 "%s quota file already specified",
1672 				 QTYPE2NAME(qtype));
1673 		goto errout;
1674 	}
1675 	if (strchr(qname, '/')) {
1676 		ext4_msg(sb, KERN_ERR,
1677 			"quotafile must be on filesystem root");
1678 		goto errout;
1679 	}
1680 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1681 	set_opt(sb, QUOTA);
1682 	return 1;
1683 errout:
1684 	kfree(qname);
1685 	return ret;
1686 }
1687 
1688 static int clear_qf_name(struct super_block *sb, int qtype)
1689 {
1690 
1691 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1692 	char *old_qname = get_qf_name(sb, sbi, qtype);
1693 
1694 	if (sb_any_quota_loaded(sb) && old_qname) {
1695 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1696 			" when quota turned on");
1697 		return -1;
1698 	}
1699 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1700 	synchronize_rcu();
1701 	kfree(old_qname);
1702 	return 1;
1703 }
1704 #endif
1705 
1706 #define MOPT_SET	0x0001
1707 #define MOPT_CLEAR	0x0002
1708 #define MOPT_NOSUPPORT	0x0004
1709 #define MOPT_EXPLICIT	0x0008
1710 #define MOPT_CLEAR_ERR	0x0010
1711 #define MOPT_GTE0	0x0020
1712 #ifdef CONFIG_QUOTA
1713 #define MOPT_Q		0
1714 #define MOPT_QFMT	0x0040
1715 #else
1716 #define MOPT_Q		MOPT_NOSUPPORT
1717 #define MOPT_QFMT	MOPT_NOSUPPORT
1718 #endif
1719 #define MOPT_DATAJ	0x0080
1720 #define MOPT_NO_EXT2	0x0100
1721 #define MOPT_NO_EXT3	0x0200
1722 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1723 #define MOPT_STRING	0x0400
1724 
1725 static const struct mount_opts {
1726 	int	token;
1727 	int	mount_opt;
1728 	int	flags;
1729 } ext4_mount_opts[] = {
1730 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1731 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1732 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1733 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1734 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1735 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1736 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1737 	 MOPT_EXT4_ONLY | MOPT_SET},
1738 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1739 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1740 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1741 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1742 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1743 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1744 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1745 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1746 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1747 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1748 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1749 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1750 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1751 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1752 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1753 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1754 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1755 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1756 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1757 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1758 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1759 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1760 	 MOPT_NO_EXT2},
1761 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1762 	 MOPT_NO_EXT2},
1763 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1764 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1765 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1766 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1767 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1768 	{Opt_commit, 0, MOPT_GTE0},
1769 	{Opt_max_batch_time, 0, MOPT_GTE0},
1770 	{Opt_min_batch_time, 0, MOPT_GTE0},
1771 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1772 	{Opt_init_itable, 0, MOPT_GTE0},
1773 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1774 	{Opt_stripe, 0, MOPT_GTE0},
1775 	{Opt_resuid, 0, MOPT_GTE0},
1776 	{Opt_resgid, 0, MOPT_GTE0},
1777 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1778 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1779 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1780 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1781 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1782 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1783 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1784 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1785 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1786 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1787 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1788 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1789 #else
1790 	{Opt_acl, 0, MOPT_NOSUPPORT},
1791 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1792 #endif
1793 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1794 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1795 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1796 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1797 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1798 							MOPT_SET | MOPT_Q},
1799 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1800 							MOPT_SET | MOPT_Q},
1801 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1802 							MOPT_SET | MOPT_Q},
1803 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1804 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1805 							MOPT_CLEAR | MOPT_Q},
1806 	{Opt_usrjquota, 0, MOPT_Q},
1807 	{Opt_grpjquota, 0, MOPT_Q},
1808 	{Opt_offusrjquota, 0, MOPT_Q},
1809 	{Opt_offgrpjquota, 0, MOPT_Q},
1810 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1811 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1812 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1813 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1814 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1815 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1816 	{Opt_err, 0, 0}
1817 };
1818 
1819 #ifdef CONFIG_UNICODE
1820 static const struct ext4_sb_encodings {
1821 	__u16 magic;
1822 	char *name;
1823 	char *version;
1824 } ext4_sb_encoding_map[] = {
1825 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
1826 };
1827 
1828 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
1829 				 const struct ext4_sb_encodings **encoding,
1830 				 __u16 *flags)
1831 {
1832 	__u16 magic = le16_to_cpu(es->s_encoding);
1833 	int i;
1834 
1835 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1836 		if (magic == ext4_sb_encoding_map[i].magic)
1837 			break;
1838 
1839 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
1840 		return -EINVAL;
1841 
1842 	*encoding = &ext4_sb_encoding_map[i];
1843 	*flags = le16_to_cpu(es->s_encoding_flags);
1844 
1845 	return 0;
1846 }
1847 #endif
1848 
1849 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1850 			    substring_t *args, unsigned long *journal_devnum,
1851 			    unsigned int *journal_ioprio, int is_remount)
1852 {
1853 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1854 	const struct mount_opts *m;
1855 	kuid_t uid;
1856 	kgid_t gid;
1857 	int arg = 0;
1858 
1859 #ifdef CONFIG_QUOTA
1860 	if (token == Opt_usrjquota)
1861 		return set_qf_name(sb, USRQUOTA, &args[0]);
1862 	else if (token == Opt_grpjquota)
1863 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1864 	else if (token == Opt_offusrjquota)
1865 		return clear_qf_name(sb, USRQUOTA);
1866 	else if (token == Opt_offgrpjquota)
1867 		return clear_qf_name(sb, GRPQUOTA);
1868 #endif
1869 	switch (token) {
1870 	case Opt_noacl:
1871 	case Opt_nouser_xattr:
1872 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1873 		break;
1874 	case Opt_sb:
1875 		return 1;	/* handled by get_sb_block() */
1876 	case Opt_removed:
1877 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1878 		return 1;
1879 	case Opt_abort:
1880 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1881 		return 1;
1882 	case Opt_i_version:
1883 		sb->s_flags |= SB_I_VERSION;
1884 		return 1;
1885 	case Opt_lazytime:
1886 		sb->s_flags |= SB_LAZYTIME;
1887 		return 1;
1888 	case Opt_nolazytime:
1889 		sb->s_flags &= ~SB_LAZYTIME;
1890 		return 1;
1891 	}
1892 
1893 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1894 		if (token == m->token)
1895 			break;
1896 
1897 	if (m->token == Opt_err) {
1898 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1899 			 "or missing value", opt);
1900 		return -1;
1901 	}
1902 
1903 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1904 		ext4_msg(sb, KERN_ERR,
1905 			 "Mount option \"%s\" incompatible with ext2", opt);
1906 		return -1;
1907 	}
1908 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1909 		ext4_msg(sb, KERN_ERR,
1910 			 "Mount option \"%s\" incompatible with ext3", opt);
1911 		return -1;
1912 	}
1913 
1914 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1915 		return -1;
1916 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1917 		return -1;
1918 	if (m->flags & MOPT_EXPLICIT) {
1919 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1920 			set_opt2(sb, EXPLICIT_DELALLOC);
1921 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1922 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1923 		} else
1924 			return -1;
1925 	}
1926 	if (m->flags & MOPT_CLEAR_ERR)
1927 		clear_opt(sb, ERRORS_MASK);
1928 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1929 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1930 			 "options when quota turned on");
1931 		return -1;
1932 	}
1933 
1934 	if (m->flags & MOPT_NOSUPPORT) {
1935 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1936 	} else if (token == Opt_commit) {
1937 		if (arg == 0)
1938 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1939 		else if (arg > INT_MAX / HZ) {
1940 			ext4_msg(sb, KERN_ERR,
1941 				 "Invalid commit interval %d, "
1942 				 "must be smaller than %d",
1943 				 arg, INT_MAX / HZ);
1944 			return -1;
1945 		}
1946 		sbi->s_commit_interval = HZ * arg;
1947 	} else if (token == Opt_debug_want_extra_isize) {
1948 		if ((arg & 1) ||
1949 		    (arg < 4) ||
1950 		    (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
1951 			ext4_msg(sb, KERN_ERR,
1952 				 "Invalid want_extra_isize %d", arg);
1953 			return -1;
1954 		}
1955 		sbi->s_want_extra_isize = arg;
1956 	} else if (token == Opt_max_batch_time) {
1957 		sbi->s_max_batch_time = arg;
1958 	} else if (token == Opt_min_batch_time) {
1959 		sbi->s_min_batch_time = arg;
1960 	} else if (token == Opt_inode_readahead_blks) {
1961 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1962 			ext4_msg(sb, KERN_ERR,
1963 				 "EXT4-fs: inode_readahead_blks must be "
1964 				 "0 or a power of 2 smaller than 2^31");
1965 			return -1;
1966 		}
1967 		sbi->s_inode_readahead_blks = arg;
1968 	} else if (token == Opt_init_itable) {
1969 		set_opt(sb, INIT_INODE_TABLE);
1970 		if (!args->from)
1971 			arg = EXT4_DEF_LI_WAIT_MULT;
1972 		sbi->s_li_wait_mult = arg;
1973 	} else if (token == Opt_max_dir_size_kb) {
1974 		sbi->s_max_dir_size_kb = arg;
1975 	} else if (token == Opt_stripe) {
1976 		sbi->s_stripe = arg;
1977 	} else if (token == Opt_resuid) {
1978 		uid = make_kuid(current_user_ns(), arg);
1979 		if (!uid_valid(uid)) {
1980 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1981 			return -1;
1982 		}
1983 		sbi->s_resuid = uid;
1984 	} else if (token == Opt_resgid) {
1985 		gid = make_kgid(current_user_ns(), arg);
1986 		if (!gid_valid(gid)) {
1987 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1988 			return -1;
1989 		}
1990 		sbi->s_resgid = gid;
1991 	} else if (token == Opt_journal_dev) {
1992 		if (is_remount) {
1993 			ext4_msg(sb, KERN_ERR,
1994 				 "Cannot specify journal on remount");
1995 			return -1;
1996 		}
1997 		*journal_devnum = arg;
1998 	} else if (token == Opt_journal_path) {
1999 		char *journal_path;
2000 		struct inode *journal_inode;
2001 		struct path path;
2002 		int error;
2003 
2004 		if (is_remount) {
2005 			ext4_msg(sb, KERN_ERR,
2006 				 "Cannot specify journal on remount");
2007 			return -1;
2008 		}
2009 		journal_path = match_strdup(&args[0]);
2010 		if (!journal_path) {
2011 			ext4_msg(sb, KERN_ERR, "error: could not dup "
2012 				"journal device string");
2013 			return -1;
2014 		}
2015 
2016 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
2017 		if (error) {
2018 			ext4_msg(sb, KERN_ERR, "error: could not find "
2019 				"journal device path: error %d", error);
2020 			kfree(journal_path);
2021 			return -1;
2022 		}
2023 
2024 		journal_inode = d_inode(path.dentry);
2025 		if (!S_ISBLK(journal_inode->i_mode)) {
2026 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
2027 				"is not a block device", journal_path);
2028 			path_put(&path);
2029 			kfree(journal_path);
2030 			return -1;
2031 		}
2032 
2033 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
2034 		path_put(&path);
2035 		kfree(journal_path);
2036 	} else if (token == Opt_journal_ioprio) {
2037 		if (arg > 7) {
2038 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
2039 				 " (must be 0-7)");
2040 			return -1;
2041 		}
2042 		*journal_ioprio =
2043 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
2044 	} else if (token == Opt_test_dummy_encryption) {
2045 #ifdef CONFIG_FS_ENCRYPTION
2046 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
2047 		ext4_msg(sb, KERN_WARNING,
2048 			 "Test dummy encryption mode enabled");
2049 #else
2050 		ext4_msg(sb, KERN_WARNING,
2051 			 "Test dummy encryption mount option ignored");
2052 #endif
2053 	} else if (m->flags & MOPT_DATAJ) {
2054 		if (is_remount) {
2055 			if (!sbi->s_journal)
2056 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2057 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2058 				ext4_msg(sb, KERN_ERR,
2059 					 "Cannot change data mode on remount");
2060 				return -1;
2061 			}
2062 		} else {
2063 			clear_opt(sb, DATA_FLAGS);
2064 			sbi->s_mount_opt |= m->mount_opt;
2065 		}
2066 #ifdef CONFIG_QUOTA
2067 	} else if (m->flags & MOPT_QFMT) {
2068 		if (sb_any_quota_loaded(sb) &&
2069 		    sbi->s_jquota_fmt != m->mount_opt) {
2070 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2071 				 "quota options when quota turned on");
2072 			return -1;
2073 		}
2074 		if (ext4_has_feature_quota(sb)) {
2075 			ext4_msg(sb, KERN_INFO,
2076 				 "Quota format mount options ignored "
2077 				 "when QUOTA feature is enabled");
2078 			return 1;
2079 		}
2080 		sbi->s_jquota_fmt = m->mount_opt;
2081 #endif
2082 	} else if (token == Opt_dax) {
2083 #ifdef CONFIG_FS_DAX
2084 		ext4_msg(sb, KERN_WARNING,
2085 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2086 		sbi->s_mount_opt |= m->mount_opt;
2087 #else
2088 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2089 		return -1;
2090 #endif
2091 	} else if (token == Opt_data_err_abort) {
2092 		sbi->s_mount_opt |= m->mount_opt;
2093 	} else if (token == Opt_data_err_ignore) {
2094 		sbi->s_mount_opt &= ~m->mount_opt;
2095 	} else {
2096 		if (!args->from)
2097 			arg = 1;
2098 		if (m->flags & MOPT_CLEAR)
2099 			arg = !arg;
2100 		else if (unlikely(!(m->flags & MOPT_SET))) {
2101 			ext4_msg(sb, KERN_WARNING,
2102 				 "buggy handling of option %s", opt);
2103 			WARN_ON(1);
2104 			return -1;
2105 		}
2106 		if (arg != 0)
2107 			sbi->s_mount_opt |= m->mount_opt;
2108 		else
2109 			sbi->s_mount_opt &= ~m->mount_opt;
2110 	}
2111 	return 1;
2112 }
2113 
2114 static int parse_options(char *options, struct super_block *sb,
2115 			 unsigned long *journal_devnum,
2116 			 unsigned int *journal_ioprio,
2117 			 int is_remount)
2118 {
2119 	struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2120 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2121 	substring_t args[MAX_OPT_ARGS];
2122 	int token;
2123 
2124 	if (!options)
2125 		return 1;
2126 
2127 	while ((p = strsep(&options, ",")) != NULL) {
2128 		if (!*p)
2129 			continue;
2130 		/*
2131 		 * Initialize args struct so we know whether arg was
2132 		 * found; some options take optional arguments.
2133 		 */
2134 		args[0].to = args[0].from = NULL;
2135 		token = match_token(p, tokens, args);
2136 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2137 				     journal_ioprio, is_remount) < 0)
2138 			return 0;
2139 	}
2140 #ifdef CONFIG_QUOTA
2141 	/*
2142 	 * We do the test below only for project quotas. 'usrquota' and
2143 	 * 'grpquota' mount options are allowed even without quota feature
2144 	 * to support legacy quotas in quota files.
2145 	 */
2146 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2147 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2148 			 "Cannot enable project quota enforcement.");
2149 		return 0;
2150 	}
2151 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2152 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2153 	if (usr_qf_name || grp_qf_name) {
2154 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2155 			clear_opt(sb, USRQUOTA);
2156 
2157 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2158 			clear_opt(sb, GRPQUOTA);
2159 
2160 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2161 			ext4_msg(sb, KERN_ERR, "old and new quota "
2162 					"format mixing");
2163 			return 0;
2164 		}
2165 
2166 		if (!sbi->s_jquota_fmt) {
2167 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2168 					"not specified");
2169 			return 0;
2170 		}
2171 	}
2172 #endif
2173 	return 1;
2174 }
2175 
2176 static inline void ext4_show_quota_options(struct seq_file *seq,
2177 					   struct super_block *sb)
2178 {
2179 #if defined(CONFIG_QUOTA)
2180 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2181 	char *usr_qf_name, *grp_qf_name;
2182 
2183 	if (sbi->s_jquota_fmt) {
2184 		char *fmtname = "";
2185 
2186 		switch (sbi->s_jquota_fmt) {
2187 		case QFMT_VFS_OLD:
2188 			fmtname = "vfsold";
2189 			break;
2190 		case QFMT_VFS_V0:
2191 			fmtname = "vfsv0";
2192 			break;
2193 		case QFMT_VFS_V1:
2194 			fmtname = "vfsv1";
2195 			break;
2196 		}
2197 		seq_printf(seq, ",jqfmt=%s", fmtname);
2198 	}
2199 
2200 	rcu_read_lock();
2201 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2202 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2203 	if (usr_qf_name)
2204 		seq_show_option(seq, "usrjquota", usr_qf_name);
2205 	if (grp_qf_name)
2206 		seq_show_option(seq, "grpjquota", grp_qf_name);
2207 	rcu_read_unlock();
2208 #endif
2209 }
2210 
2211 static const char *token2str(int token)
2212 {
2213 	const struct match_token *t;
2214 
2215 	for (t = tokens; t->token != Opt_err; t++)
2216 		if (t->token == token && !strchr(t->pattern, '='))
2217 			break;
2218 	return t->pattern;
2219 }
2220 
2221 /*
2222  * Show an option if
2223  *  - it's set to a non-default value OR
2224  *  - if the per-sb default is different from the global default
2225  */
2226 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2227 			      int nodefs)
2228 {
2229 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2230 	struct ext4_super_block *es = sbi->s_es;
2231 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2232 	const struct mount_opts *m;
2233 	char sep = nodefs ? '\n' : ',';
2234 
2235 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2236 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2237 
2238 	if (sbi->s_sb_block != 1)
2239 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2240 
2241 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2242 		int want_set = m->flags & MOPT_SET;
2243 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2244 		    (m->flags & MOPT_CLEAR_ERR))
2245 			continue;
2246 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2247 			continue; /* skip if same as the default */
2248 		if ((want_set &&
2249 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2250 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2251 			continue; /* select Opt_noFoo vs Opt_Foo */
2252 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2253 	}
2254 
2255 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2256 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2257 		SEQ_OPTS_PRINT("resuid=%u",
2258 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2259 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2260 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2261 		SEQ_OPTS_PRINT("resgid=%u",
2262 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2263 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2264 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2265 		SEQ_OPTS_PUTS("errors=remount-ro");
2266 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2267 		SEQ_OPTS_PUTS("errors=continue");
2268 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2269 		SEQ_OPTS_PUTS("errors=panic");
2270 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2271 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2272 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2273 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2274 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2275 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2276 	if (sb->s_flags & SB_I_VERSION)
2277 		SEQ_OPTS_PUTS("i_version");
2278 	if (nodefs || sbi->s_stripe)
2279 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2280 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2281 			(sbi->s_mount_opt ^ def_mount_opt)) {
2282 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2283 			SEQ_OPTS_PUTS("data=journal");
2284 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2285 			SEQ_OPTS_PUTS("data=ordered");
2286 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2287 			SEQ_OPTS_PUTS("data=writeback");
2288 	}
2289 	if (nodefs ||
2290 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2291 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2292 			       sbi->s_inode_readahead_blks);
2293 
2294 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2295 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2296 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2297 	if (nodefs || sbi->s_max_dir_size_kb)
2298 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2299 	if (test_opt(sb, DATA_ERR_ABORT))
2300 		SEQ_OPTS_PUTS("data_err=abort");
2301 	if (DUMMY_ENCRYPTION_ENABLED(sbi))
2302 		SEQ_OPTS_PUTS("test_dummy_encryption");
2303 
2304 	ext4_show_quota_options(seq, sb);
2305 	return 0;
2306 }
2307 
2308 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2309 {
2310 	return _ext4_show_options(seq, root->d_sb, 0);
2311 }
2312 
2313 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2314 {
2315 	struct super_block *sb = seq->private;
2316 	int rc;
2317 
2318 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2319 	rc = _ext4_show_options(seq, sb, 1);
2320 	seq_puts(seq, "\n");
2321 	return rc;
2322 }
2323 
2324 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2325 			    int read_only)
2326 {
2327 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2328 	int err = 0;
2329 
2330 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2331 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2332 			 "forcing read-only mode");
2333 		err = -EROFS;
2334 	}
2335 	if (read_only)
2336 		goto done;
2337 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2338 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2339 			 "running e2fsck is recommended");
2340 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2341 		ext4_msg(sb, KERN_WARNING,
2342 			 "warning: mounting fs with errors, "
2343 			 "running e2fsck is recommended");
2344 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2345 		 le16_to_cpu(es->s_mnt_count) >=
2346 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2347 		ext4_msg(sb, KERN_WARNING,
2348 			 "warning: maximal mount count reached, "
2349 			 "running e2fsck is recommended");
2350 	else if (le32_to_cpu(es->s_checkinterval) &&
2351 		 (ext4_get_tstamp(es, s_lastcheck) +
2352 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2353 		ext4_msg(sb, KERN_WARNING,
2354 			 "warning: checktime reached, "
2355 			 "running e2fsck is recommended");
2356 	if (!sbi->s_journal)
2357 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2358 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2359 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2360 	le16_add_cpu(&es->s_mnt_count, 1);
2361 	ext4_update_tstamp(es, s_mtime);
2362 	if (sbi->s_journal)
2363 		ext4_set_feature_journal_needs_recovery(sb);
2364 
2365 	err = ext4_commit_super(sb, 1);
2366 done:
2367 	if (test_opt(sb, DEBUG))
2368 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2369 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2370 			sb->s_blocksize,
2371 			sbi->s_groups_count,
2372 			EXT4_BLOCKS_PER_GROUP(sb),
2373 			EXT4_INODES_PER_GROUP(sb),
2374 			sbi->s_mount_opt, sbi->s_mount_opt2);
2375 
2376 	cleancache_init_fs(sb);
2377 	return err;
2378 }
2379 
2380 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2381 {
2382 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2383 	struct flex_groups *new_groups;
2384 	int size;
2385 
2386 	if (!sbi->s_log_groups_per_flex)
2387 		return 0;
2388 
2389 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2390 	if (size <= sbi->s_flex_groups_allocated)
2391 		return 0;
2392 
2393 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2394 	new_groups = kvzalloc(size, GFP_KERNEL);
2395 	if (!new_groups) {
2396 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2397 			 size / (int) sizeof(struct flex_groups));
2398 		return -ENOMEM;
2399 	}
2400 
2401 	if (sbi->s_flex_groups) {
2402 		memcpy(new_groups, sbi->s_flex_groups,
2403 		       (sbi->s_flex_groups_allocated *
2404 			sizeof(struct flex_groups)));
2405 		kvfree(sbi->s_flex_groups);
2406 	}
2407 	sbi->s_flex_groups = new_groups;
2408 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2409 	return 0;
2410 }
2411 
2412 static int ext4_fill_flex_info(struct super_block *sb)
2413 {
2414 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2415 	struct ext4_group_desc *gdp = NULL;
2416 	ext4_group_t flex_group;
2417 	int i, err;
2418 
2419 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2420 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2421 		sbi->s_log_groups_per_flex = 0;
2422 		return 1;
2423 	}
2424 
2425 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2426 	if (err)
2427 		goto failed;
2428 
2429 	for (i = 0; i < sbi->s_groups_count; i++) {
2430 		gdp = ext4_get_group_desc(sb, i, NULL);
2431 
2432 		flex_group = ext4_flex_group(sbi, i);
2433 		atomic_add(ext4_free_inodes_count(sb, gdp),
2434 			   &sbi->s_flex_groups[flex_group].free_inodes);
2435 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2436 			     &sbi->s_flex_groups[flex_group].free_clusters);
2437 		atomic_add(ext4_used_dirs_count(sb, gdp),
2438 			   &sbi->s_flex_groups[flex_group].used_dirs);
2439 	}
2440 
2441 	return 1;
2442 failed:
2443 	return 0;
2444 }
2445 
2446 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2447 				   struct ext4_group_desc *gdp)
2448 {
2449 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2450 	__u16 crc = 0;
2451 	__le32 le_group = cpu_to_le32(block_group);
2452 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2453 
2454 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2455 		/* Use new metadata_csum algorithm */
2456 		__u32 csum32;
2457 		__u16 dummy_csum = 0;
2458 
2459 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2460 				     sizeof(le_group));
2461 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2462 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2463 				     sizeof(dummy_csum));
2464 		offset += sizeof(dummy_csum);
2465 		if (offset < sbi->s_desc_size)
2466 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2467 					     sbi->s_desc_size - offset);
2468 
2469 		crc = csum32 & 0xFFFF;
2470 		goto out;
2471 	}
2472 
2473 	/* old crc16 code */
2474 	if (!ext4_has_feature_gdt_csum(sb))
2475 		return 0;
2476 
2477 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2478 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2479 	crc = crc16(crc, (__u8 *)gdp, offset);
2480 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2481 	/* for checksum of struct ext4_group_desc do the rest...*/
2482 	if (ext4_has_feature_64bit(sb) &&
2483 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2484 		crc = crc16(crc, (__u8 *)gdp + offset,
2485 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2486 				offset);
2487 
2488 out:
2489 	return cpu_to_le16(crc);
2490 }
2491 
2492 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2493 				struct ext4_group_desc *gdp)
2494 {
2495 	if (ext4_has_group_desc_csum(sb) &&
2496 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2497 		return 0;
2498 
2499 	return 1;
2500 }
2501 
2502 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2503 			      struct ext4_group_desc *gdp)
2504 {
2505 	if (!ext4_has_group_desc_csum(sb))
2506 		return;
2507 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2508 }
2509 
2510 /* Called at mount-time, super-block is locked */
2511 static int ext4_check_descriptors(struct super_block *sb,
2512 				  ext4_fsblk_t sb_block,
2513 				  ext4_group_t *first_not_zeroed)
2514 {
2515 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2516 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2517 	ext4_fsblk_t last_block;
2518 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2519 	ext4_fsblk_t block_bitmap;
2520 	ext4_fsblk_t inode_bitmap;
2521 	ext4_fsblk_t inode_table;
2522 	int flexbg_flag = 0;
2523 	ext4_group_t i, grp = sbi->s_groups_count;
2524 
2525 	if (ext4_has_feature_flex_bg(sb))
2526 		flexbg_flag = 1;
2527 
2528 	ext4_debug("Checking group descriptors");
2529 
2530 	for (i = 0; i < sbi->s_groups_count; i++) {
2531 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2532 
2533 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2534 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2535 		else
2536 			last_block = first_block +
2537 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2538 
2539 		if ((grp == sbi->s_groups_count) &&
2540 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2541 			grp = i;
2542 
2543 		block_bitmap = ext4_block_bitmap(sb, gdp);
2544 		if (block_bitmap == sb_block) {
2545 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2546 				 "Block bitmap for group %u overlaps "
2547 				 "superblock", i);
2548 			if (!sb_rdonly(sb))
2549 				return 0;
2550 		}
2551 		if (block_bitmap >= sb_block + 1 &&
2552 		    block_bitmap <= last_bg_block) {
2553 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2554 				 "Block bitmap for group %u overlaps "
2555 				 "block group descriptors", i);
2556 			if (!sb_rdonly(sb))
2557 				return 0;
2558 		}
2559 		if (block_bitmap < first_block || block_bitmap > last_block) {
2560 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2561 			       "Block bitmap for group %u not in group "
2562 			       "(block %llu)!", i, block_bitmap);
2563 			return 0;
2564 		}
2565 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2566 		if (inode_bitmap == sb_block) {
2567 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2568 				 "Inode bitmap for group %u overlaps "
2569 				 "superblock", i);
2570 			if (!sb_rdonly(sb))
2571 				return 0;
2572 		}
2573 		if (inode_bitmap >= sb_block + 1 &&
2574 		    inode_bitmap <= last_bg_block) {
2575 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2576 				 "Inode bitmap for group %u overlaps "
2577 				 "block group descriptors", i);
2578 			if (!sb_rdonly(sb))
2579 				return 0;
2580 		}
2581 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2582 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2583 			       "Inode bitmap for group %u not in group "
2584 			       "(block %llu)!", i, inode_bitmap);
2585 			return 0;
2586 		}
2587 		inode_table = ext4_inode_table(sb, gdp);
2588 		if (inode_table == sb_block) {
2589 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2590 				 "Inode table for group %u overlaps "
2591 				 "superblock", i);
2592 			if (!sb_rdonly(sb))
2593 				return 0;
2594 		}
2595 		if (inode_table >= sb_block + 1 &&
2596 		    inode_table <= last_bg_block) {
2597 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2598 				 "Inode table for group %u overlaps "
2599 				 "block group descriptors", i);
2600 			if (!sb_rdonly(sb))
2601 				return 0;
2602 		}
2603 		if (inode_table < first_block ||
2604 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2605 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2606 			       "Inode table for group %u not in group "
2607 			       "(block %llu)!", i, inode_table);
2608 			return 0;
2609 		}
2610 		ext4_lock_group(sb, i);
2611 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2612 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2613 				 "Checksum for group %u failed (%u!=%u)",
2614 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2615 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2616 			if (!sb_rdonly(sb)) {
2617 				ext4_unlock_group(sb, i);
2618 				return 0;
2619 			}
2620 		}
2621 		ext4_unlock_group(sb, i);
2622 		if (!flexbg_flag)
2623 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2624 	}
2625 	if (NULL != first_not_zeroed)
2626 		*first_not_zeroed = grp;
2627 	return 1;
2628 }
2629 
2630 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2631  * the superblock) which were deleted from all directories, but held open by
2632  * a process at the time of a crash.  We walk the list and try to delete these
2633  * inodes at recovery time (only with a read-write filesystem).
2634  *
2635  * In order to keep the orphan inode chain consistent during traversal (in
2636  * case of crash during recovery), we link each inode into the superblock
2637  * orphan list_head and handle it the same way as an inode deletion during
2638  * normal operation (which journals the operations for us).
2639  *
2640  * We only do an iget() and an iput() on each inode, which is very safe if we
2641  * accidentally point at an in-use or already deleted inode.  The worst that
2642  * can happen in this case is that we get a "bit already cleared" message from
2643  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2644  * e2fsck was run on this filesystem, and it must have already done the orphan
2645  * inode cleanup for us, so we can safely abort without any further action.
2646  */
2647 static void ext4_orphan_cleanup(struct super_block *sb,
2648 				struct ext4_super_block *es)
2649 {
2650 	unsigned int s_flags = sb->s_flags;
2651 	int ret, nr_orphans = 0, nr_truncates = 0;
2652 #ifdef CONFIG_QUOTA
2653 	int quota_update = 0;
2654 	int i;
2655 #endif
2656 	if (!es->s_last_orphan) {
2657 		jbd_debug(4, "no orphan inodes to clean up\n");
2658 		return;
2659 	}
2660 
2661 	if (bdev_read_only(sb->s_bdev)) {
2662 		ext4_msg(sb, KERN_ERR, "write access "
2663 			"unavailable, skipping orphan cleanup");
2664 		return;
2665 	}
2666 
2667 	/* Check if feature set would not allow a r/w mount */
2668 	if (!ext4_feature_set_ok(sb, 0)) {
2669 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2670 			 "unknown ROCOMPAT features");
2671 		return;
2672 	}
2673 
2674 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2675 		/* don't clear list on RO mount w/ errors */
2676 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2677 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2678 				  "clearing orphan list.\n");
2679 			es->s_last_orphan = 0;
2680 		}
2681 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2682 		return;
2683 	}
2684 
2685 	if (s_flags & SB_RDONLY) {
2686 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2687 		sb->s_flags &= ~SB_RDONLY;
2688 	}
2689 #ifdef CONFIG_QUOTA
2690 	/* Needed for iput() to work correctly and not trash data */
2691 	sb->s_flags |= SB_ACTIVE;
2692 
2693 	/*
2694 	 * Turn on quotas which were not enabled for read-only mounts if
2695 	 * filesystem has quota feature, so that they are updated correctly.
2696 	 */
2697 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2698 		int ret = ext4_enable_quotas(sb);
2699 
2700 		if (!ret)
2701 			quota_update = 1;
2702 		else
2703 			ext4_msg(sb, KERN_ERR,
2704 				"Cannot turn on quotas: error %d", ret);
2705 	}
2706 
2707 	/* Turn on journaled quotas used for old sytle */
2708 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2709 		if (EXT4_SB(sb)->s_qf_names[i]) {
2710 			int ret = ext4_quota_on_mount(sb, i);
2711 
2712 			if (!ret)
2713 				quota_update = 1;
2714 			else
2715 				ext4_msg(sb, KERN_ERR,
2716 					"Cannot turn on journaled "
2717 					"quota: type %d: error %d", i, ret);
2718 		}
2719 	}
2720 #endif
2721 
2722 	while (es->s_last_orphan) {
2723 		struct inode *inode;
2724 
2725 		/*
2726 		 * We may have encountered an error during cleanup; if
2727 		 * so, skip the rest.
2728 		 */
2729 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2730 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2731 			es->s_last_orphan = 0;
2732 			break;
2733 		}
2734 
2735 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2736 		if (IS_ERR(inode)) {
2737 			es->s_last_orphan = 0;
2738 			break;
2739 		}
2740 
2741 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2742 		dquot_initialize(inode);
2743 		if (inode->i_nlink) {
2744 			if (test_opt(sb, DEBUG))
2745 				ext4_msg(sb, KERN_DEBUG,
2746 					"%s: truncating inode %lu to %lld bytes",
2747 					__func__, inode->i_ino, inode->i_size);
2748 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2749 				  inode->i_ino, inode->i_size);
2750 			inode_lock(inode);
2751 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2752 			ret = ext4_truncate(inode);
2753 			if (ret)
2754 				ext4_std_error(inode->i_sb, ret);
2755 			inode_unlock(inode);
2756 			nr_truncates++;
2757 		} else {
2758 			if (test_opt(sb, DEBUG))
2759 				ext4_msg(sb, KERN_DEBUG,
2760 					"%s: deleting unreferenced inode %lu",
2761 					__func__, inode->i_ino);
2762 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2763 				  inode->i_ino);
2764 			nr_orphans++;
2765 		}
2766 		iput(inode);  /* The delete magic happens here! */
2767 	}
2768 
2769 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2770 
2771 	if (nr_orphans)
2772 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2773 		       PLURAL(nr_orphans));
2774 	if (nr_truncates)
2775 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2776 		       PLURAL(nr_truncates));
2777 #ifdef CONFIG_QUOTA
2778 	/* Turn off quotas if they were enabled for orphan cleanup */
2779 	if (quota_update) {
2780 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2781 			if (sb_dqopt(sb)->files[i])
2782 				dquot_quota_off(sb, i);
2783 		}
2784 	}
2785 #endif
2786 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2787 }
2788 
2789 /*
2790  * Maximal extent format file size.
2791  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2792  * extent format containers, within a sector_t, and within i_blocks
2793  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2794  * so that won't be a limiting factor.
2795  *
2796  * However there is other limiting factor. We do store extents in the form
2797  * of starting block and length, hence the resulting length of the extent
2798  * covering maximum file size must fit into on-disk format containers as
2799  * well. Given that length is always by 1 unit bigger than max unit (because
2800  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2801  *
2802  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2803  */
2804 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2805 {
2806 	loff_t res;
2807 	loff_t upper_limit = MAX_LFS_FILESIZE;
2808 
2809 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
2810 
2811 	if (!has_huge_files) {
2812 		upper_limit = (1LL << 32) - 1;
2813 
2814 		/* total blocks in file system block size */
2815 		upper_limit >>= (blkbits - 9);
2816 		upper_limit <<= blkbits;
2817 	}
2818 
2819 	/*
2820 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2821 	 * by one fs block, so ee_len can cover the extent of maximum file
2822 	 * size
2823 	 */
2824 	res = (1LL << 32) - 1;
2825 	res <<= blkbits;
2826 
2827 	/* Sanity check against vm- & vfs- imposed limits */
2828 	if (res > upper_limit)
2829 		res = upper_limit;
2830 
2831 	return res;
2832 }
2833 
2834 /*
2835  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2836  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2837  * We need to be 1 filesystem block less than the 2^48 sector limit.
2838  */
2839 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2840 {
2841 	loff_t res = EXT4_NDIR_BLOCKS;
2842 	int meta_blocks;
2843 	loff_t upper_limit;
2844 	/* This is calculated to be the largest file size for a dense, block
2845 	 * mapped file such that the file's total number of 512-byte sectors,
2846 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2847 	 *
2848 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2849 	 * number of 512-byte sectors of the file.
2850 	 */
2851 
2852 	if (!has_huge_files) {
2853 		/*
2854 		 * !has_huge_files or implies that the inode i_block field
2855 		 * represents total file blocks in 2^32 512-byte sectors ==
2856 		 * size of vfs inode i_blocks * 8
2857 		 */
2858 		upper_limit = (1LL << 32) - 1;
2859 
2860 		/* total blocks in file system block size */
2861 		upper_limit >>= (bits - 9);
2862 
2863 	} else {
2864 		/*
2865 		 * We use 48 bit ext4_inode i_blocks
2866 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2867 		 * represent total number of blocks in
2868 		 * file system block size
2869 		 */
2870 		upper_limit = (1LL << 48) - 1;
2871 
2872 	}
2873 
2874 	/* indirect blocks */
2875 	meta_blocks = 1;
2876 	/* double indirect blocks */
2877 	meta_blocks += 1 + (1LL << (bits-2));
2878 	/* tripple indirect blocks */
2879 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2880 
2881 	upper_limit -= meta_blocks;
2882 	upper_limit <<= bits;
2883 
2884 	res += 1LL << (bits-2);
2885 	res += 1LL << (2*(bits-2));
2886 	res += 1LL << (3*(bits-2));
2887 	res <<= bits;
2888 	if (res > upper_limit)
2889 		res = upper_limit;
2890 
2891 	if (res > MAX_LFS_FILESIZE)
2892 		res = MAX_LFS_FILESIZE;
2893 
2894 	return res;
2895 }
2896 
2897 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2898 				   ext4_fsblk_t logical_sb_block, int nr)
2899 {
2900 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2901 	ext4_group_t bg, first_meta_bg;
2902 	int has_super = 0;
2903 
2904 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2905 
2906 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2907 		return logical_sb_block + nr + 1;
2908 	bg = sbi->s_desc_per_block * nr;
2909 	if (ext4_bg_has_super(sb, bg))
2910 		has_super = 1;
2911 
2912 	/*
2913 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2914 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2915 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2916 	 * compensate.
2917 	 */
2918 	if (sb->s_blocksize == 1024 && nr == 0 &&
2919 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2920 		has_super++;
2921 
2922 	return (has_super + ext4_group_first_block_no(sb, bg));
2923 }
2924 
2925 /**
2926  * ext4_get_stripe_size: Get the stripe size.
2927  * @sbi: In memory super block info
2928  *
2929  * If we have specified it via mount option, then
2930  * use the mount option value. If the value specified at mount time is
2931  * greater than the blocks per group use the super block value.
2932  * If the super block value is greater than blocks per group return 0.
2933  * Allocator needs it be less than blocks per group.
2934  *
2935  */
2936 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2937 {
2938 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2939 	unsigned long stripe_width =
2940 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2941 	int ret;
2942 
2943 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2944 		ret = sbi->s_stripe;
2945 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2946 		ret = stripe_width;
2947 	else if (stride && stride <= sbi->s_blocks_per_group)
2948 		ret = stride;
2949 	else
2950 		ret = 0;
2951 
2952 	/*
2953 	 * If the stripe width is 1, this makes no sense and
2954 	 * we set it to 0 to turn off stripe handling code.
2955 	 */
2956 	if (ret <= 1)
2957 		ret = 0;
2958 
2959 	return ret;
2960 }
2961 
2962 /*
2963  * Check whether this filesystem can be mounted based on
2964  * the features present and the RDONLY/RDWR mount requested.
2965  * Returns 1 if this filesystem can be mounted as requested,
2966  * 0 if it cannot be.
2967  */
2968 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2969 {
2970 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2971 		ext4_msg(sb, KERN_ERR,
2972 			"Couldn't mount because of "
2973 			"unsupported optional features (%x)",
2974 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2975 			~EXT4_FEATURE_INCOMPAT_SUPP));
2976 		return 0;
2977 	}
2978 
2979 #ifndef CONFIG_UNICODE
2980 	if (ext4_has_feature_casefold(sb)) {
2981 		ext4_msg(sb, KERN_ERR,
2982 			 "Filesystem with casefold feature cannot be "
2983 			 "mounted without CONFIG_UNICODE");
2984 		return 0;
2985 	}
2986 #endif
2987 
2988 	if (readonly)
2989 		return 1;
2990 
2991 	if (ext4_has_feature_readonly(sb)) {
2992 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2993 		sb->s_flags |= SB_RDONLY;
2994 		return 1;
2995 	}
2996 
2997 	/* Check that feature set is OK for a read-write mount */
2998 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2999 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3000 			 "unsupported optional features (%x)",
3001 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3002 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3003 		return 0;
3004 	}
3005 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3006 		ext4_msg(sb, KERN_ERR,
3007 			 "Can't support bigalloc feature without "
3008 			 "extents feature\n");
3009 		return 0;
3010 	}
3011 
3012 #ifndef CONFIG_QUOTA
3013 	if (ext4_has_feature_quota(sb) && !readonly) {
3014 		ext4_msg(sb, KERN_ERR,
3015 			 "Filesystem with quota feature cannot be mounted RDWR "
3016 			 "without CONFIG_QUOTA");
3017 		return 0;
3018 	}
3019 	if (ext4_has_feature_project(sb) && !readonly) {
3020 		ext4_msg(sb, KERN_ERR,
3021 			 "Filesystem with project quota feature cannot be mounted RDWR "
3022 			 "without CONFIG_QUOTA");
3023 		return 0;
3024 	}
3025 #endif  /* CONFIG_QUOTA */
3026 	return 1;
3027 }
3028 
3029 /*
3030  * This function is called once a day if we have errors logged
3031  * on the file system
3032  */
3033 static void print_daily_error_info(struct timer_list *t)
3034 {
3035 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3036 	struct super_block *sb = sbi->s_sb;
3037 	struct ext4_super_block *es = sbi->s_es;
3038 
3039 	if (es->s_error_count)
3040 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3041 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3042 			 le32_to_cpu(es->s_error_count));
3043 	if (es->s_first_error_time) {
3044 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3045 		       sb->s_id,
3046 		       ext4_get_tstamp(es, s_first_error_time),
3047 		       (int) sizeof(es->s_first_error_func),
3048 		       es->s_first_error_func,
3049 		       le32_to_cpu(es->s_first_error_line));
3050 		if (es->s_first_error_ino)
3051 			printk(KERN_CONT ": inode %u",
3052 			       le32_to_cpu(es->s_first_error_ino));
3053 		if (es->s_first_error_block)
3054 			printk(KERN_CONT ": block %llu", (unsigned long long)
3055 			       le64_to_cpu(es->s_first_error_block));
3056 		printk(KERN_CONT "\n");
3057 	}
3058 	if (es->s_last_error_time) {
3059 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3060 		       sb->s_id,
3061 		       ext4_get_tstamp(es, s_last_error_time),
3062 		       (int) sizeof(es->s_last_error_func),
3063 		       es->s_last_error_func,
3064 		       le32_to_cpu(es->s_last_error_line));
3065 		if (es->s_last_error_ino)
3066 			printk(KERN_CONT ": inode %u",
3067 			       le32_to_cpu(es->s_last_error_ino));
3068 		if (es->s_last_error_block)
3069 			printk(KERN_CONT ": block %llu", (unsigned long long)
3070 			       le64_to_cpu(es->s_last_error_block));
3071 		printk(KERN_CONT "\n");
3072 	}
3073 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3074 }
3075 
3076 /* Find next suitable group and run ext4_init_inode_table */
3077 static int ext4_run_li_request(struct ext4_li_request *elr)
3078 {
3079 	struct ext4_group_desc *gdp = NULL;
3080 	ext4_group_t group, ngroups;
3081 	struct super_block *sb;
3082 	unsigned long timeout = 0;
3083 	int ret = 0;
3084 
3085 	sb = elr->lr_super;
3086 	ngroups = EXT4_SB(sb)->s_groups_count;
3087 
3088 	for (group = elr->lr_next_group; group < ngroups; group++) {
3089 		gdp = ext4_get_group_desc(sb, group, NULL);
3090 		if (!gdp) {
3091 			ret = 1;
3092 			break;
3093 		}
3094 
3095 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3096 			break;
3097 	}
3098 
3099 	if (group >= ngroups)
3100 		ret = 1;
3101 
3102 	if (!ret) {
3103 		timeout = jiffies;
3104 		ret = ext4_init_inode_table(sb, group,
3105 					    elr->lr_timeout ? 0 : 1);
3106 		if (elr->lr_timeout == 0) {
3107 			timeout = (jiffies - timeout) *
3108 				  elr->lr_sbi->s_li_wait_mult;
3109 			elr->lr_timeout = timeout;
3110 		}
3111 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3112 		elr->lr_next_group = group + 1;
3113 	}
3114 	return ret;
3115 }
3116 
3117 /*
3118  * Remove lr_request from the list_request and free the
3119  * request structure. Should be called with li_list_mtx held
3120  */
3121 static void ext4_remove_li_request(struct ext4_li_request *elr)
3122 {
3123 	struct ext4_sb_info *sbi;
3124 
3125 	if (!elr)
3126 		return;
3127 
3128 	sbi = elr->lr_sbi;
3129 
3130 	list_del(&elr->lr_request);
3131 	sbi->s_li_request = NULL;
3132 	kfree(elr);
3133 }
3134 
3135 static void ext4_unregister_li_request(struct super_block *sb)
3136 {
3137 	mutex_lock(&ext4_li_mtx);
3138 	if (!ext4_li_info) {
3139 		mutex_unlock(&ext4_li_mtx);
3140 		return;
3141 	}
3142 
3143 	mutex_lock(&ext4_li_info->li_list_mtx);
3144 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3145 	mutex_unlock(&ext4_li_info->li_list_mtx);
3146 	mutex_unlock(&ext4_li_mtx);
3147 }
3148 
3149 static struct task_struct *ext4_lazyinit_task;
3150 
3151 /*
3152  * This is the function where ext4lazyinit thread lives. It walks
3153  * through the request list searching for next scheduled filesystem.
3154  * When such a fs is found, run the lazy initialization request
3155  * (ext4_rn_li_request) and keep track of the time spend in this
3156  * function. Based on that time we compute next schedule time of
3157  * the request. When walking through the list is complete, compute
3158  * next waking time and put itself into sleep.
3159  */
3160 static int ext4_lazyinit_thread(void *arg)
3161 {
3162 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3163 	struct list_head *pos, *n;
3164 	struct ext4_li_request *elr;
3165 	unsigned long next_wakeup, cur;
3166 
3167 	BUG_ON(NULL == eli);
3168 
3169 cont_thread:
3170 	while (true) {
3171 		next_wakeup = MAX_JIFFY_OFFSET;
3172 
3173 		mutex_lock(&eli->li_list_mtx);
3174 		if (list_empty(&eli->li_request_list)) {
3175 			mutex_unlock(&eli->li_list_mtx);
3176 			goto exit_thread;
3177 		}
3178 		list_for_each_safe(pos, n, &eli->li_request_list) {
3179 			int err = 0;
3180 			int progress = 0;
3181 			elr = list_entry(pos, struct ext4_li_request,
3182 					 lr_request);
3183 
3184 			if (time_before(jiffies, elr->lr_next_sched)) {
3185 				if (time_before(elr->lr_next_sched, next_wakeup))
3186 					next_wakeup = elr->lr_next_sched;
3187 				continue;
3188 			}
3189 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3190 				if (sb_start_write_trylock(elr->lr_super)) {
3191 					progress = 1;
3192 					/*
3193 					 * We hold sb->s_umount, sb can not
3194 					 * be removed from the list, it is
3195 					 * now safe to drop li_list_mtx
3196 					 */
3197 					mutex_unlock(&eli->li_list_mtx);
3198 					err = ext4_run_li_request(elr);
3199 					sb_end_write(elr->lr_super);
3200 					mutex_lock(&eli->li_list_mtx);
3201 					n = pos->next;
3202 				}
3203 				up_read((&elr->lr_super->s_umount));
3204 			}
3205 			/* error, remove the lazy_init job */
3206 			if (err) {
3207 				ext4_remove_li_request(elr);
3208 				continue;
3209 			}
3210 			if (!progress) {
3211 				elr->lr_next_sched = jiffies +
3212 					(prandom_u32()
3213 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3214 			}
3215 			if (time_before(elr->lr_next_sched, next_wakeup))
3216 				next_wakeup = elr->lr_next_sched;
3217 		}
3218 		mutex_unlock(&eli->li_list_mtx);
3219 
3220 		try_to_freeze();
3221 
3222 		cur = jiffies;
3223 		if ((time_after_eq(cur, next_wakeup)) ||
3224 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3225 			cond_resched();
3226 			continue;
3227 		}
3228 
3229 		schedule_timeout_interruptible(next_wakeup - cur);
3230 
3231 		if (kthread_should_stop()) {
3232 			ext4_clear_request_list();
3233 			goto exit_thread;
3234 		}
3235 	}
3236 
3237 exit_thread:
3238 	/*
3239 	 * It looks like the request list is empty, but we need
3240 	 * to check it under the li_list_mtx lock, to prevent any
3241 	 * additions into it, and of course we should lock ext4_li_mtx
3242 	 * to atomically free the list and ext4_li_info, because at
3243 	 * this point another ext4 filesystem could be registering
3244 	 * new one.
3245 	 */
3246 	mutex_lock(&ext4_li_mtx);
3247 	mutex_lock(&eli->li_list_mtx);
3248 	if (!list_empty(&eli->li_request_list)) {
3249 		mutex_unlock(&eli->li_list_mtx);
3250 		mutex_unlock(&ext4_li_mtx);
3251 		goto cont_thread;
3252 	}
3253 	mutex_unlock(&eli->li_list_mtx);
3254 	kfree(ext4_li_info);
3255 	ext4_li_info = NULL;
3256 	mutex_unlock(&ext4_li_mtx);
3257 
3258 	return 0;
3259 }
3260 
3261 static void ext4_clear_request_list(void)
3262 {
3263 	struct list_head *pos, *n;
3264 	struct ext4_li_request *elr;
3265 
3266 	mutex_lock(&ext4_li_info->li_list_mtx);
3267 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3268 		elr = list_entry(pos, struct ext4_li_request,
3269 				 lr_request);
3270 		ext4_remove_li_request(elr);
3271 	}
3272 	mutex_unlock(&ext4_li_info->li_list_mtx);
3273 }
3274 
3275 static int ext4_run_lazyinit_thread(void)
3276 {
3277 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3278 					 ext4_li_info, "ext4lazyinit");
3279 	if (IS_ERR(ext4_lazyinit_task)) {
3280 		int err = PTR_ERR(ext4_lazyinit_task);
3281 		ext4_clear_request_list();
3282 		kfree(ext4_li_info);
3283 		ext4_li_info = NULL;
3284 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3285 				 "initialization thread\n",
3286 				 err);
3287 		return err;
3288 	}
3289 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3290 	return 0;
3291 }
3292 
3293 /*
3294  * Check whether it make sense to run itable init. thread or not.
3295  * If there is at least one uninitialized inode table, return
3296  * corresponding group number, else the loop goes through all
3297  * groups and return total number of groups.
3298  */
3299 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3300 {
3301 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3302 	struct ext4_group_desc *gdp = NULL;
3303 
3304 	if (!ext4_has_group_desc_csum(sb))
3305 		return ngroups;
3306 
3307 	for (group = 0; group < ngroups; group++) {
3308 		gdp = ext4_get_group_desc(sb, group, NULL);
3309 		if (!gdp)
3310 			continue;
3311 
3312 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3313 			break;
3314 	}
3315 
3316 	return group;
3317 }
3318 
3319 static int ext4_li_info_new(void)
3320 {
3321 	struct ext4_lazy_init *eli = NULL;
3322 
3323 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3324 	if (!eli)
3325 		return -ENOMEM;
3326 
3327 	INIT_LIST_HEAD(&eli->li_request_list);
3328 	mutex_init(&eli->li_list_mtx);
3329 
3330 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3331 
3332 	ext4_li_info = eli;
3333 
3334 	return 0;
3335 }
3336 
3337 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3338 					    ext4_group_t start)
3339 {
3340 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3341 	struct ext4_li_request *elr;
3342 
3343 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3344 	if (!elr)
3345 		return NULL;
3346 
3347 	elr->lr_super = sb;
3348 	elr->lr_sbi = sbi;
3349 	elr->lr_next_group = start;
3350 
3351 	/*
3352 	 * Randomize first schedule time of the request to
3353 	 * spread the inode table initialization requests
3354 	 * better.
3355 	 */
3356 	elr->lr_next_sched = jiffies + (prandom_u32() %
3357 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3358 	return elr;
3359 }
3360 
3361 int ext4_register_li_request(struct super_block *sb,
3362 			     ext4_group_t first_not_zeroed)
3363 {
3364 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3365 	struct ext4_li_request *elr = NULL;
3366 	ext4_group_t ngroups = sbi->s_groups_count;
3367 	int ret = 0;
3368 
3369 	mutex_lock(&ext4_li_mtx);
3370 	if (sbi->s_li_request != NULL) {
3371 		/*
3372 		 * Reset timeout so it can be computed again, because
3373 		 * s_li_wait_mult might have changed.
3374 		 */
3375 		sbi->s_li_request->lr_timeout = 0;
3376 		goto out;
3377 	}
3378 
3379 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3380 	    !test_opt(sb, INIT_INODE_TABLE))
3381 		goto out;
3382 
3383 	elr = ext4_li_request_new(sb, first_not_zeroed);
3384 	if (!elr) {
3385 		ret = -ENOMEM;
3386 		goto out;
3387 	}
3388 
3389 	if (NULL == ext4_li_info) {
3390 		ret = ext4_li_info_new();
3391 		if (ret)
3392 			goto out;
3393 	}
3394 
3395 	mutex_lock(&ext4_li_info->li_list_mtx);
3396 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3397 	mutex_unlock(&ext4_li_info->li_list_mtx);
3398 
3399 	sbi->s_li_request = elr;
3400 	/*
3401 	 * set elr to NULL here since it has been inserted to
3402 	 * the request_list and the removal and free of it is
3403 	 * handled by ext4_clear_request_list from now on.
3404 	 */
3405 	elr = NULL;
3406 
3407 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3408 		ret = ext4_run_lazyinit_thread();
3409 		if (ret)
3410 			goto out;
3411 	}
3412 out:
3413 	mutex_unlock(&ext4_li_mtx);
3414 	if (ret)
3415 		kfree(elr);
3416 	return ret;
3417 }
3418 
3419 /*
3420  * We do not need to lock anything since this is called on
3421  * module unload.
3422  */
3423 static void ext4_destroy_lazyinit_thread(void)
3424 {
3425 	/*
3426 	 * If thread exited earlier
3427 	 * there's nothing to be done.
3428 	 */
3429 	if (!ext4_li_info || !ext4_lazyinit_task)
3430 		return;
3431 
3432 	kthread_stop(ext4_lazyinit_task);
3433 }
3434 
3435 static int set_journal_csum_feature_set(struct super_block *sb)
3436 {
3437 	int ret = 1;
3438 	int compat, incompat;
3439 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3440 
3441 	if (ext4_has_metadata_csum(sb)) {
3442 		/* journal checksum v3 */
3443 		compat = 0;
3444 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3445 	} else {
3446 		/* journal checksum v1 */
3447 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3448 		incompat = 0;
3449 	}
3450 
3451 	jbd2_journal_clear_features(sbi->s_journal,
3452 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3453 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3454 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3455 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3456 		ret = jbd2_journal_set_features(sbi->s_journal,
3457 				compat, 0,
3458 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3459 				incompat);
3460 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3461 		ret = jbd2_journal_set_features(sbi->s_journal,
3462 				compat, 0,
3463 				incompat);
3464 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3465 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3466 	} else {
3467 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3468 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3469 	}
3470 
3471 	return ret;
3472 }
3473 
3474 /*
3475  * Note: calculating the overhead so we can be compatible with
3476  * historical BSD practice is quite difficult in the face of
3477  * clusters/bigalloc.  This is because multiple metadata blocks from
3478  * different block group can end up in the same allocation cluster.
3479  * Calculating the exact overhead in the face of clustered allocation
3480  * requires either O(all block bitmaps) in memory or O(number of block
3481  * groups**2) in time.  We will still calculate the superblock for
3482  * older file systems --- and if we come across with a bigalloc file
3483  * system with zero in s_overhead_clusters the estimate will be close to
3484  * correct especially for very large cluster sizes --- but for newer
3485  * file systems, it's better to calculate this figure once at mkfs
3486  * time, and store it in the superblock.  If the superblock value is
3487  * present (even for non-bigalloc file systems), we will use it.
3488  */
3489 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3490 			  char *buf)
3491 {
3492 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3493 	struct ext4_group_desc	*gdp;
3494 	ext4_fsblk_t		first_block, last_block, b;
3495 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3496 	int			s, j, count = 0;
3497 
3498 	if (!ext4_has_feature_bigalloc(sb))
3499 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3500 			sbi->s_itb_per_group + 2);
3501 
3502 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3503 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3504 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3505 	for (i = 0; i < ngroups; i++) {
3506 		gdp = ext4_get_group_desc(sb, i, NULL);
3507 		b = ext4_block_bitmap(sb, gdp);
3508 		if (b >= first_block && b <= last_block) {
3509 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3510 			count++;
3511 		}
3512 		b = ext4_inode_bitmap(sb, gdp);
3513 		if (b >= first_block && b <= last_block) {
3514 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3515 			count++;
3516 		}
3517 		b = ext4_inode_table(sb, gdp);
3518 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3519 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3520 				int c = EXT4_B2C(sbi, b - first_block);
3521 				ext4_set_bit(c, buf);
3522 				count++;
3523 			}
3524 		if (i != grp)
3525 			continue;
3526 		s = 0;
3527 		if (ext4_bg_has_super(sb, grp)) {
3528 			ext4_set_bit(s++, buf);
3529 			count++;
3530 		}
3531 		j = ext4_bg_num_gdb(sb, grp);
3532 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3533 			ext4_error(sb, "Invalid number of block group "
3534 				   "descriptor blocks: %d", j);
3535 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3536 		}
3537 		count += j;
3538 		for (; j > 0; j--)
3539 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3540 	}
3541 	if (!count)
3542 		return 0;
3543 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3544 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3545 }
3546 
3547 /*
3548  * Compute the overhead and stash it in sbi->s_overhead
3549  */
3550 int ext4_calculate_overhead(struct super_block *sb)
3551 {
3552 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3553 	struct ext4_super_block *es = sbi->s_es;
3554 	struct inode *j_inode;
3555 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3556 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3557 	ext4_fsblk_t overhead = 0;
3558 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3559 
3560 	if (!buf)
3561 		return -ENOMEM;
3562 
3563 	/*
3564 	 * Compute the overhead (FS structures).  This is constant
3565 	 * for a given filesystem unless the number of block groups
3566 	 * changes so we cache the previous value until it does.
3567 	 */
3568 
3569 	/*
3570 	 * All of the blocks before first_data_block are overhead
3571 	 */
3572 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3573 
3574 	/*
3575 	 * Add the overhead found in each block group
3576 	 */
3577 	for (i = 0; i < ngroups; i++) {
3578 		int blks;
3579 
3580 		blks = count_overhead(sb, i, buf);
3581 		overhead += blks;
3582 		if (blks)
3583 			memset(buf, 0, PAGE_SIZE);
3584 		cond_resched();
3585 	}
3586 
3587 	/*
3588 	 * Add the internal journal blocks whether the journal has been
3589 	 * loaded or not
3590 	 */
3591 	if (sbi->s_journal && !sbi->journal_bdev)
3592 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3593 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3594 		j_inode = ext4_get_journal_inode(sb, j_inum);
3595 		if (j_inode) {
3596 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3597 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3598 			iput(j_inode);
3599 		} else {
3600 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3601 		}
3602 	}
3603 	sbi->s_overhead = overhead;
3604 	smp_wmb();
3605 	free_page((unsigned long) buf);
3606 	return 0;
3607 }
3608 
3609 static void ext4_set_resv_clusters(struct super_block *sb)
3610 {
3611 	ext4_fsblk_t resv_clusters;
3612 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3613 
3614 	/*
3615 	 * There's no need to reserve anything when we aren't using extents.
3616 	 * The space estimates are exact, there are no unwritten extents,
3617 	 * hole punching doesn't need new metadata... This is needed especially
3618 	 * to keep ext2/3 backward compatibility.
3619 	 */
3620 	if (!ext4_has_feature_extents(sb))
3621 		return;
3622 	/*
3623 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3624 	 * This should cover the situations where we can not afford to run
3625 	 * out of space like for example punch hole, or converting
3626 	 * unwritten extents in delalloc path. In most cases such
3627 	 * allocation would require 1, or 2 blocks, higher numbers are
3628 	 * very rare.
3629 	 */
3630 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3631 			 sbi->s_cluster_bits);
3632 
3633 	do_div(resv_clusters, 50);
3634 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3635 
3636 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3637 }
3638 
3639 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3640 {
3641 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3642 	char *orig_data = kstrdup(data, GFP_KERNEL);
3643 	struct buffer_head *bh;
3644 	struct ext4_super_block *es = NULL;
3645 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3646 	ext4_fsblk_t block;
3647 	ext4_fsblk_t sb_block = get_sb_block(&data);
3648 	ext4_fsblk_t logical_sb_block;
3649 	unsigned long offset = 0;
3650 	unsigned long journal_devnum = 0;
3651 	unsigned long def_mount_opts;
3652 	struct inode *root;
3653 	const char *descr;
3654 	int ret = -ENOMEM;
3655 	int blocksize, clustersize;
3656 	unsigned int db_count;
3657 	unsigned int i;
3658 	int needs_recovery, has_huge_files, has_bigalloc;
3659 	__u64 blocks_count;
3660 	int err = 0;
3661 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3662 	ext4_group_t first_not_zeroed;
3663 
3664 	if ((data && !orig_data) || !sbi)
3665 		goto out_free_base;
3666 
3667 	sbi->s_daxdev = dax_dev;
3668 	sbi->s_blockgroup_lock =
3669 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3670 	if (!sbi->s_blockgroup_lock)
3671 		goto out_free_base;
3672 
3673 	sb->s_fs_info = sbi;
3674 	sbi->s_sb = sb;
3675 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3676 	sbi->s_sb_block = sb_block;
3677 	if (sb->s_bdev->bd_part)
3678 		sbi->s_sectors_written_start =
3679 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3680 
3681 	/* Cleanup superblock name */
3682 	strreplace(sb->s_id, '/', '!');
3683 
3684 	/* -EINVAL is default */
3685 	ret = -EINVAL;
3686 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3687 	if (!blocksize) {
3688 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3689 		goto out_fail;
3690 	}
3691 
3692 	/*
3693 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3694 	 * block sizes.  We need to calculate the offset from buffer start.
3695 	 */
3696 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3697 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3698 		offset = do_div(logical_sb_block, blocksize);
3699 	} else {
3700 		logical_sb_block = sb_block;
3701 	}
3702 
3703 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3704 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3705 		goto out_fail;
3706 	}
3707 	/*
3708 	 * Note: s_es must be initialized as soon as possible because
3709 	 *       some ext4 macro-instructions depend on its value
3710 	 */
3711 	es = (struct ext4_super_block *) (bh->b_data + offset);
3712 	sbi->s_es = es;
3713 	sb->s_magic = le16_to_cpu(es->s_magic);
3714 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3715 		goto cantfind_ext4;
3716 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3717 
3718 	/* Warn if metadata_csum and gdt_csum are both set. */
3719 	if (ext4_has_feature_metadata_csum(sb) &&
3720 	    ext4_has_feature_gdt_csum(sb))
3721 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3722 			     "redundant flags; please run fsck.");
3723 
3724 	/* Check for a known checksum algorithm */
3725 	if (!ext4_verify_csum_type(sb, es)) {
3726 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3727 			 "unknown checksum algorithm.");
3728 		silent = 1;
3729 		goto cantfind_ext4;
3730 	}
3731 
3732 	/* Load the checksum driver */
3733 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3734 	if (IS_ERR(sbi->s_chksum_driver)) {
3735 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3736 		ret = PTR_ERR(sbi->s_chksum_driver);
3737 		sbi->s_chksum_driver = NULL;
3738 		goto failed_mount;
3739 	}
3740 
3741 	/* Check superblock checksum */
3742 	if (!ext4_superblock_csum_verify(sb, es)) {
3743 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3744 			 "invalid superblock checksum.  Run e2fsck?");
3745 		silent = 1;
3746 		ret = -EFSBADCRC;
3747 		goto cantfind_ext4;
3748 	}
3749 
3750 	/* Precompute checksum seed for all metadata */
3751 	if (ext4_has_feature_csum_seed(sb))
3752 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3753 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3754 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3755 					       sizeof(es->s_uuid));
3756 
3757 	/* Set defaults before we parse the mount options */
3758 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3759 	set_opt(sb, INIT_INODE_TABLE);
3760 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3761 		set_opt(sb, DEBUG);
3762 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3763 		set_opt(sb, GRPID);
3764 	if (def_mount_opts & EXT4_DEFM_UID16)
3765 		set_opt(sb, NO_UID32);
3766 	/* xattr user namespace & acls are now defaulted on */
3767 	set_opt(sb, XATTR_USER);
3768 	set_opt(sb, DIOREAD_NOLOCK);
3769 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3770 	set_opt(sb, POSIX_ACL);
3771 #endif
3772 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3773 	if (ext4_has_metadata_csum(sb))
3774 		set_opt(sb, JOURNAL_CHECKSUM);
3775 
3776 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3777 		set_opt(sb, JOURNAL_DATA);
3778 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3779 		set_opt(sb, ORDERED_DATA);
3780 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3781 		set_opt(sb, WRITEBACK_DATA);
3782 
3783 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3784 		set_opt(sb, ERRORS_PANIC);
3785 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3786 		set_opt(sb, ERRORS_CONT);
3787 	else
3788 		set_opt(sb, ERRORS_RO);
3789 	/* block_validity enabled by default; disable with noblock_validity */
3790 	set_opt(sb, BLOCK_VALIDITY);
3791 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3792 		set_opt(sb, DISCARD);
3793 
3794 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3795 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3796 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3797 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3798 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3799 
3800 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3801 		set_opt(sb, BARRIER);
3802 
3803 	/*
3804 	 * enable delayed allocation by default
3805 	 * Use -o nodelalloc to turn it off
3806 	 */
3807 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3808 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3809 		set_opt(sb, DELALLOC);
3810 
3811 	/*
3812 	 * set default s_li_wait_mult for lazyinit, for the case there is
3813 	 * no mount option specified.
3814 	 */
3815 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3816 
3817 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3818 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3819 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3820 	} else {
3821 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3822 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3823 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3824 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3825 				 sbi->s_first_ino);
3826 			goto failed_mount;
3827 		}
3828 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3829 		    (!is_power_of_2(sbi->s_inode_size)) ||
3830 		    (sbi->s_inode_size > blocksize)) {
3831 			ext4_msg(sb, KERN_ERR,
3832 			       "unsupported inode size: %d",
3833 			       sbi->s_inode_size);
3834 			goto failed_mount;
3835 		}
3836 		/*
3837 		 * i_atime_extra is the last extra field available for
3838 		 * [acm]times in struct ext4_inode. Checking for that
3839 		 * field should suffice to ensure we have extra space
3840 		 * for all three.
3841 		 */
3842 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
3843 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
3844 			sb->s_time_gran = 1;
3845 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
3846 		} else {
3847 			sb->s_time_gran = NSEC_PER_SEC;
3848 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
3849 		}
3850 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
3851 	}
3852 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3853 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3854 			EXT4_GOOD_OLD_INODE_SIZE;
3855 		if (ext4_has_feature_extra_isize(sb)) {
3856 			unsigned v, max = (sbi->s_inode_size -
3857 					   EXT4_GOOD_OLD_INODE_SIZE);
3858 
3859 			v = le16_to_cpu(es->s_want_extra_isize);
3860 			if (v > max) {
3861 				ext4_msg(sb, KERN_ERR,
3862 					 "bad s_want_extra_isize: %d", v);
3863 				goto failed_mount;
3864 			}
3865 			if (sbi->s_want_extra_isize < v)
3866 				sbi->s_want_extra_isize = v;
3867 
3868 			v = le16_to_cpu(es->s_min_extra_isize);
3869 			if (v > max) {
3870 				ext4_msg(sb, KERN_ERR,
3871 					 "bad s_min_extra_isize: %d", v);
3872 				goto failed_mount;
3873 			}
3874 			if (sbi->s_want_extra_isize < v)
3875 				sbi->s_want_extra_isize = v;
3876 		}
3877 	}
3878 
3879 	if (sbi->s_es->s_mount_opts[0]) {
3880 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3881 					      sizeof(sbi->s_es->s_mount_opts),
3882 					      GFP_KERNEL);
3883 		if (!s_mount_opts)
3884 			goto failed_mount;
3885 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3886 				   &journal_ioprio, 0)) {
3887 			ext4_msg(sb, KERN_WARNING,
3888 				 "failed to parse options in superblock: %s",
3889 				 s_mount_opts);
3890 		}
3891 		kfree(s_mount_opts);
3892 	}
3893 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3894 	if (!parse_options((char *) data, sb, &journal_devnum,
3895 			   &journal_ioprio, 0))
3896 		goto failed_mount;
3897 
3898 #ifdef CONFIG_UNICODE
3899 	if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
3900 		const struct ext4_sb_encodings *encoding_info;
3901 		struct unicode_map *encoding;
3902 		__u16 encoding_flags;
3903 
3904 		if (ext4_has_feature_encrypt(sb)) {
3905 			ext4_msg(sb, KERN_ERR,
3906 				 "Can't mount with encoding and encryption");
3907 			goto failed_mount;
3908 		}
3909 
3910 		if (ext4_sb_read_encoding(es, &encoding_info,
3911 					  &encoding_flags)) {
3912 			ext4_msg(sb, KERN_ERR,
3913 				 "Encoding requested by superblock is unknown");
3914 			goto failed_mount;
3915 		}
3916 
3917 		encoding = utf8_load(encoding_info->version);
3918 		if (IS_ERR(encoding)) {
3919 			ext4_msg(sb, KERN_ERR,
3920 				 "can't mount with superblock charset: %s-%s "
3921 				 "not supported by the kernel. flags: 0x%x.",
3922 				 encoding_info->name, encoding_info->version,
3923 				 encoding_flags);
3924 			goto failed_mount;
3925 		}
3926 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
3927 			 "%s-%s with flags 0x%hx", encoding_info->name,
3928 			 encoding_info->version?:"\b", encoding_flags);
3929 
3930 		sbi->s_encoding = encoding;
3931 		sbi->s_encoding_flags = encoding_flags;
3932 	}
3933 #endif
3934 
3935 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3936 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, and O_DIRECT support!\n");
3937 		clear_opt(sb, DIOREAD_NOLOCK);
3938 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3939 			ext4_msg(sb, KERN_ERR, "can't mount with "
3940 				 "both data=journal and delalloc");
3941 			goto failed_mount;
3942 		}
3943 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3944 			ext4_msg(sb, KERN_ERR, "can't mount with "
3945 				 "both data=journal and dioread_nolock");
3946 			goto failed_mount;
3947 		}
3948 		if (test_opt(sb, DAX)) {
3949 			ext4_msg(sb, KERN_ERR, "can't mount with "
3950 				 "both data=journal and dax");
3951 			goto failed_mount;
3952 		}
3953 		if (ext4_has_feature_encrypt(sb)) {
3954 			ext4_msg(sb, KERN_WARNING,
3955 				 "encrypted files will use data=ordered "
3956 				 "instead of data journaling mode");
3957 		}
3958 		if (test_opt(sb, DELALLOC))
3959 			clear_opt(sb, DELALLOC);
3960 	} else {
3961 		sb->s_iflags |= SB_I_CGROUPWB;
3962 	}
3963 
3964 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3965 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3966 
3967 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3968 	    (ext4_has_compat_features(sb) ||
3969 	     ext4_has_ro_compat_features(sb) ||
3970 	     ext4_has_incompat_features(sb)))
3971 		ext4_msg(sb, KERN_WARNING,
3972 		       "feature flags set on rev 0 fs, "
3973 		       "running e2fsck is recommended");
3974 
3975 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3976 		set_opt2(sb, HURD_COMPAT);
3977 		if (ext4_has_feature_64bit(sb)) {
3978 			ext4_msg(sb, KERN_ERR,
3979 				 "The Hurd can't support 64-bit file systems");
3980 			goto failed_mount;
3981 		}
3982 
3983 		/*
3984 		 * ea_inode feature uses l_i_version field which is not
3985 		 * available in HURD_COMPAT mode.
3986 		 */
3987 		if (ext4_has_feature_ea_inode(sb)) {
3988 			ext4_msg(sb, KERN_ERR,
3989 				 "ea_inode feature is not supported for Hurd");
3990 			goto failed_mount;
3991 		}
3992 	}
3993 
3994 	if (IS_EXT2_SB(sb)) {
3995 		if (ext2_feature_set_ok(sb))
3996 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3997 				 "using the ext4 subsystem");
3998 		else {
3999 			/*
4000 			 * If we're probing be silent, if this looks like
4001 			 * it's actually an ext[34] filesystem.
4002 			 */
4003 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4004 				goto failed_mount;
4005 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4006 				 "to feature incompatibilities");
4007 			goto failed_mount;
4008 		}
4009 	}
4010 
4011 	if (IS_EXT3_SB(sb)) {
4012 		if (ext3_feature_set_ok(sb))
4013 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4014 				 "using the ext4 subsystem");
4015 		else {
4016 			/*
4017 			 * If we're probing be silent, if this looks like
4018 			 * it's actually an ext4 filesystem.
4019 			 */
4020 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4021 				goto failed_mount;
4022 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4023 				 "to feature incompatibilities");
4024 			goto failed_mount;
4025 		}
4026 	}
4027 
4028 	/*
4029 	 * Check feature flags regardless of the revision level, since we
4030 	 * previously didn't change the revision level when setting the flags,
4031 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4032 	 */
4033 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4034 		goto failed_mount;
4035 
4036 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4037 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
4038 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
4039 		ext4_msg(sb, KERN_ERR,
4040 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
4041 			 blocksize, le32_to_cpu(es->s_log_block_size));
4042 		goto failed_mount;
4043 	}
4044 	if (le32_to_cpu(es->s_log_block_size) >
4045 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4046 		ext4_msg(sb, KERN_ERR,
4047 			 "Invalid log block size: %u",
4048 			 le32_to_cpu(es->s_log_block_size));
4049 		goto failed_mount;
4050 	}
4051 	if (le32_to_cpu(es->s_log_cluster_size) >
4052 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4053 		ext4_msg(sb, KERN_ERR,
4054 			 "Invalid log cluster size: %u",
4055 			 le32_to_cpu(es->s_log_cluster_size));
4056 		goto failed_mount;
4057 	}
4058 
4059 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4060 		ext4_msg(sb, KERN_ERR,
4061 			 "Number of reserved GDT blocks insanely large: %d",
4062 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4063 		goto failed_mount;
4064 	}
4065 
4066 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
4067 		if (ext4_has_feature_inline_data(sb)) {
4068 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4069 					" that may contain inline data");
4070 			goto failed_mount;
4071 		}
4072 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
4073 			ext4_msg(sb, KERN_ERR,
4074 				"DAX unsupported by block device.");
4075 			goto failed_mount;
4076 		}
4077 	}
4078 
4079 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4080 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4081 			 es->s_encryption_level);
4082 		goto failed_mount;
4083 	}
4084 
4085 	if (sb->s_blocksize != blocksize) {
4086 		/* Validate the filesystem blocksize */
4087 		if (!sb_set_blocksize(sb, blocksize)) {
4088 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4089 					blocksize);
4090 			goto failed_mount;
4091 		}
4092 
4093 		brelse(bh);
4094 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4095 		offset = do_div(logical_sb_block, blocksize);
4096 		bh = sb_bread_unmovable(sb, logical_sb_block);
4097 		if (!bh) {
4098 			ext4_msg(sb, KERN_ERR,
4099 			       "Can't read superblock on 2nd try");
4100 			goto failed_mount;
4101 		}
4102 		es = (struct ext4_super_block *)(bh->b_data + offset);
4103 		sbi->s_es = es;
4104 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4105 			ext4_msg(sb, KERN_ERR,
4106 			       "Magic mismatch, very weird!");
4107 			goto failed_mount;
4108 		}
4109 	}
4110 
4111 	has_huge_files = ext4_has_feature_huge_file(sb);
4112 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4113 						      has_huge_files);
4114 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4115 
4116 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4117 	if (ext4_has_feature_64bit(sb)) {
4118 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4119 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4120 		    !is_power_of_2(sbi->s_desc_size)) {
4121 			ext4_msg(sb, KERN_ERR,
4122 			       "unsupported descriptor size %lu",
4123 			       sbi->s_desc_size);
4124 			goto failed_mount;
4125 		}
4126 	} else
4127 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4128 
4129 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4130 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4131 
4132 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4133 	if (sbi->s_inodes_per_block == 0)
4134 		goto cantfind_ext4;
4135 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4136 	    sbi->s_inodes_per_group > blocksize * 8) {
4137 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4138 			 sbi->s_blocks_per_group);
4139 		goto failed_mount;
4140 	}
4141 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4142 					sbi->s_inodes_per_block;
4143 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4144 	sbi->s_sbh = bh;
4145 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4146 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4147 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4148 
4149 	for (i = 0; i < 4; i++)
4150 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4151 	sbi->s_def_hash_version = es->s_def_hash_version;
4152 	if (ext4_has_feature_dir_index(sb)) {
4153 		i = le32_to_cpu(es->s_flags);
4154 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4155 			sbi->s_hash_unsigned = 3;
4156 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4157 #ifdef __CHAR_UNSIGNED__
4158 			if (!sb_rdonly(sb))
4159 				es->s_flags |=
4160 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4161 			sbi->s_hash_unsigned = 3;
4162 #else
4163 			if (!sb_rdonly(sb))
4164 				es->s_flags |=
4165 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4166 #endif
4167 		}
4168 	}
4169 
4170 	/* Handle clustersize */
4171 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4172 	has_bigalloc = ext4_has_feature_bigalloc(sb);
4173 	if (has_bigalloc) {
4174 		if (clustersize < blocksize) {
4175 			ext4_msg(sb, KERN_ERR,
4176 				 "cluster size (%d) smaller than "
4177 				 "block size (%d)", clustersize, blocksize);
4178 			goto failed_mount;
4179 		}
4180 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4181 			le32_to_cpu(es->s_log_block_size);
4182 		sbi->s_clusters_per_group =
4183 			le32_to_cpu(es->s_clusters_per_group);
4184 		if (sbi->s_clusters_per_group > blocksize * 8) {
4185 			ext4_msg(sb, KERN_ERR,
4186 				 "#clusters per group too big: %lu",
4187 				 sbi->s_clusters_per_group);
4188 			goto failed_mount;
4189 		}
4190 		if (sbi->s_blocks_per_group !=
4191 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4192 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4193 				 "clusters per group (%lu) inconsistent",
4194 				 sbi->s_blocks_per_group,
4195 				 sbi->s_clusters_per_group);
4196 			goto failed_mount;
4197 		}
4198 	} else {
4199 		if (clustersize != blocksize) {
4200 			ext4_msg(sb, KERN_ERR,
4201 				 "fragment/cluster size (%d) != "
4202 				 "block size (%d)", clustersize, blocksize);
4203 			goto failed_mount;
4204 		}
4205 		if (sbi->s_blocks_per_group > blocksize * 8) {
4206 			ext4_msg(sb, KERN_ERR,
4207 				 "#blocks per group too big: %lu",
4208 				 sbi->s_blocks_per_group);
4209 			goto failed_mount;
4210 		}
4211 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4212 		sbi->s_cluster_bits = 0;
4213 	}
4214 	sbi->s_cluster_ratio = clustersize / blocksize;
4215 
4216 	/* Do we have standard group size of clustersize * 8 blocks ? */
4217 	if (sbi->s_blocks_per_group == clustersize << 3)
4218 		set_opt2(sb, STD_GROUP_SIZE);
4219 
4220 	/*
4221 	 * Test whether we have more sectors than will fit in sector_t,
4222 	 * and whether the max offset is addressable by the page cache.
4223 	 */
4224 	err = generic_check_addressable(sb->s_blocksize_bits,
4225 					ext4_blocks_count(es));
4226 	if (err) {
4227 		ext4_msg(sb, KERN_ERR, "filesystem"
4228 			 " too large to mount safely on this system");
4229 		goto failed_mount;
4230 	}
4231 
4232 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4233 		goto cantfind_ext4;
4234 
4235 	/* check blocks count against device size */
4236 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4237 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4238 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4239 		       "exceeds size of device (%llu blocks)",
4240 		       ext4_blocks_count(es), blocks_count);
4241 		goto failed_mount;
4242 	}
4243 
4244 	/*
4245 	 * It makes no sense for the first data block to be beyond the end
4246 	 * of the filesystem.
4247 	 */
4248 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4249 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4250 			 "block %u is beyond end of filesystem (%llu)",
4251 			 le32_to_cpu(es->s_first_data_block),
4252 			 ext4_blocks_count(es));
4253 		goto failed_mount;
4254 	}
4255 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4256 	    (sbi->s_cluster_ratio == 1)) {
4257 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4258 			 "block is 0 with a 1k block and cluster size");
4259 		goto failed_mount;
4260 	}
4261 
4262 	blocks_count = (ext4_blocks_count(es) -
4263 			le32_to_cpu(es->s_first_data_block) +
4264 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4265 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4266 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4267 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4268 		       "(block count %llu, first data block %u, "
4269 		       "blocks per group %lu)", sbi->s_groups_count,
4270 		       ext4_blocks_count(es),
4271 		       le32_to_cpu(es->s_first_data_block),
4272 		       EXT4_BLOCKS_PER_GROUP(sb));
4273 		goto failed_mount;
4274 	}
4275 	sbi->s_groups_count = blocks_count;
4276 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4277 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4278 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4279 	    le32_to_cpu(es->s_inodes_count)) {
4280 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4281 			 le32_to_cpu(es->s_inodes_count),
4282 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4283 		ret = -EINVAL;
4284 		goto failed_mount;
4285 	}
4286 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4287 		   EXT4_DESC_PER_BLOCK(sb);
4288 	if (ext4_has_feature_meta_bg(sb)) {
4289 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4290 			ext4_msg(sb, KERN_WARNING,
4291 				 "first meta block group too large: %u "
4292 				 "(group descriptor block count %u)",
4293 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4294 			goto failed_mount;
4295 		}
4296 	}
4297 	sbi->s_group_desc = kvmalloc_array(db_count,
4298 					   sizeof(struct buffer_head *),
4299 					   GFP_KERNEL);
4300 	if (sbi->s_group_desc == NULL) {
4301 		ext4_msg(sb, KERN_ERR, "not enough memory");
4302 		ret = -ENOMEM;
4303 		goto failed_mount;
4304 	}
4305 
4306 	bgl_lock_init(sbi->s_blockgroup_lock);
4307 
4308 	/* Pre-read the descriptors into the buffer cache */
4309 	for (i = 0; i < db_count; i++) {
4310 		block = descriptor_loc(sb, logical_sb_block, i);
4311 		sb_breadahead(sb, block);
4312 	}
4313 
4314 	for (i = 0; i < db_count; i++) {
4315 		block = descriptor_loc(sb, logical_sb_block, i);
4316 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4317 		if (!sbi->s_group_desc[i]) {
4318 			ext4_msg(sb, KERN_ERR,
4319 			       "can't read group descriptor %d", i);
4320 			db_count = i;
4321 			goto failed_mount2;
4322 		}
4323 	}
4324 	sbi->s_gdb_count = db_count;
4325 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4326 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4327 		ret = -EFSCORRUPTED;
4328 		goto failed_mount2;
4329 	}
4330 
4331 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4332 
4333 	/* Register extent status tree shrinker */
4334 	if (ext4_es_register_shrinker(sbi))
4335 		goto failed_mount3;
4336 
4337 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4338 	sbi->s_extent_max_zeroout_kb = 32;
4339 
4340 	/*
4341 	 * set up enough so that it can read an inode
4342 	 */
4343 	sb->s_op = &ext4_sops;
4344 	sb->s_export_op = &ext4_export_ops;
4345 	sb->s_xattr = ext4_xattr_handlers;
4346 #ifdef CONFIG_FS_ENCRYPTION
4347 	sb->s_cop = &ext4_cryptops;
4348 #endif
4349 #ifdef CONFIG_FS_VERITY
4350 	sb->s_vop = &ext4_verityops;
4351 #endif
4352 #ifdef CONFIG_QUOTA
4353 	sb->dq_op = &ext4_quota_operations;
4354 	if (ext4_has_feature_quota(sb))
4355 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4356 	else
4357 		sb->s_qcop = &ext4_qctl_operations;
4358 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4359 #endif
4360 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4361 
4362 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4363 	mutex_init(&sbi->s_orphan_lock);
4364 
4365 	sb->s_root = NULL;
4366 
4367 	needs_recovery = (es->s_last_orphan != 0 ||
4368 			  ext4_has_feature_journal_needs_recovery(sb));
4369 
4370 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4371 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4372 			goto failed_mount3a;
4373 
4374 	/*
4375 	 * The first inode we look at is the journal inode.  Don't try
4376 	 * root first: it may be modified in the journal!
4377 	 */
4378 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4379 		err = ext4_load_journal(sb, es, journal_devnum);
4380 		if (err)
4381 			goto failed_mount3a;
4382 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4383 		   ext4_has_feature_journal_needs_recovery(sb)) {
4384 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4385 		       "suppressed and not mounted read-only");
4386 		goto failed_mount_wq;
4387 	} else {
4388 		/* Nojournal mode, all journal mount options are illegal */
4389 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4390 			ext4_msg(sb, KERN_ERR, "can't mount with "
4391 				 "journal_checksum, fs mounted w/o journal");
4392 			goto failed_mount_wq;
4393 		}
4394 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4395 			ext4_msg(sb, KERN_ERR, "can't mount with "
4396 				 "journal_async_commit, fs mounted w/o journal");
4397 			goto failed_mount_wq;
4398 		}
4399 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4400 			ext4_msg(sb, KERN_ERR, "can't mount with "
4401 				 "commit=%lu, fs mounted w/o journal",
4402 				 sbi->s_commit_interval / HZ);
4403 			goto failed_mount_wq;
4404 		}
4405 		if (EXT4_MOUNT_DATA_FLAGS &
4406 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4407 			ext4_msg(sb, KERN_ERR, "can't mount with "
4408 				 "data=, fs mounted w/o journal");
4409 			goto failed_mount_wq;
4410 		}
4411 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4412 		clear_opt(sb, JOURNAL_CHECKSUM);
4413 		clear_opt(sb, DATA_FLAGS);
4414 		sbi->s_journal = NULL;
4415 		needs_recovery = 0;
4416 		goto no_journal;
4417 	}
4418 
4419 	if (ext4_has_feature_64bit(sb) &&
4420 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4421 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4422 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4423 		goto failed_mount_wq;
4424 	}
4425 
4426 	if (!set_journal_csum_feature_set(sb)) {
4427 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4428 			 "feature set");
4429 		goto failed_mount_wq;
4430 	}
4431 
4432 	/* We have now updated the journal if required, so we can
4433 	 * validate the data journaling mode. */
4434 	switch (test_opt(sb, DATA_FLAGS)) {
4435 	case 0:
4436 		/* No mode set, assume a default based on the journal
4437 		 * capabilities: ORDERED_DATA if the journal can
4438 		 * cope, else JOURNAL_DATA
4439 		 */
4440 		if (jbd2_journal_check_available_features
4441 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4442 			set_opt(sb, ORDERED_DATA);
4443 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4444 		} else {
4445 			set_opt(sb, JOURNAL_DATA);
4446 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4447 		}
4448 		break;
4449 
4450 	case EXT4_MOUNT_ORDERED_DATA:
4451 	case EXT4_MOUNT_WRITEBACK_DATA:
4452 		if (!jbd2_journal_check_available_features
4453 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4454 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4455 			       "requested data journaling mode");
4456 			goto failed_mount_wq;
4457 		}
4458 	default:
4459 		break;
4460 	}
4461 
4462 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4463 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4464 		ext4_msg(sb, KERN_ERR, "can't mount with "
4465 			"journal_async_commit in data=ordered mode");
4466 		goto failed_mount_wq;
4467 	}
4468 
4469 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4470 
4471 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4472 
4473 no_journal:
4474 	if (!test_opt(sb, NO_MBCACHE)) {
4475 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4476 		if (!sbi->s_ea_block_cache) {
4477 			ext4_msg(sb, KERN_ERR,
4478 				 "Failed to create ea_block_cache");
4479 			goto failed_mount_wq;
4480 		}
4481 
4482 		if (ext4_has_feature_ea_inode(sb)) {
4483 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4484 			if (!sbi->s_ea_inode_cache) {
4485 				ext4_msg(sb, KERN_ERR,
4486 					 "Failed to create ea_inode_cache");
4487 				goto failed_mount_wq;
4488 			}
4489 		}
4490 	}
4491 
4492 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4493 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4494 		goto failed_mount_wq;
4495 	}
4496 
4497 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4498 	    !ext4_has_feature_encrypt(sb)) {
4499 		ext4_set_feature_encrypt(sb);
4500 		ext4_commit_super(sb, 1);
4501 	}
4502 
4503 	/*
4504 	 * Get the # of file system overhead blocks from the
4505 	 * superblock if present.
4506 	 */
4507 	if (es->s_overhead_clusters)
4508 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4509 	else {
4510 		err = ext4_calculate_overhead(sb);
4511 		if (err)
4512 			goto failed_mount_wq;
4513 	}
4514 
4515 	/*
4516 	 * The maximum number of concurrent works can be high and
4517 	 * concurrency isn't really necessary.  Limit it to 1.
4518 	 */
4519 	EXT4_SB(sb)->rsv_conversion_wq =
4520 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4521 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4522 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4523 		ret = -ENOMEM;
4524 		goto failed_mount4;
4525 	}
4526 
4527 	/*
4528 	 * The jbd2_journal_load will have done any necessary log recovery,
4529 	 * so we can safely mount the rest of the filesystem now.
4530 	 */
4531 
4532 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4533 	if (IS_ERR(root)) {
4534 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4535 		ret = PTR_ERR(root);
4536 		root = NULL;
4537 		goto failed_mount4;
4538 	}
4539 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4540 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4541 		iput(root);
4542 		goto failed_mount4;
4543 	}
4544 
4545 #ifdef CONFIG_UNICODE
4546 	if (sbi->s_encoding)
4547 		sb->s_d_op = &ext4_dentry_ops;
4548 #endif
4549 
4550 	sb->s_root = d_make_root(root);
4551 	if (!sb->s_root) {
4552 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4553 		ret = -ENOMEM;
4554 		goto failed_mount4;
4555 	}
4556 
4557 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4558 	if (ret == -EROFS) {
4559 		sb->s_flags |= SB_RDONLY;
4560 		ret = 0;
4561 	} else if (ret)
4562 		goto failed_mount4a;
4563 
4564 	ext4_set_resv_clusters(sb);
4565 
4566 	err = ext4_setup_system_zone(sb);
4567 	if (err) {
4568 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4569 			 "zone (%d)", err);
4570 		goto failed_mount4a;
4571 	}
4572 
4573 	ext4_ext_init(sb);
4574 	err = ext4_mb_init(sb);
4575 	if (err) {
4576 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4577 			 err);
4578 		goto failed_mount5;
4579 	}
4580 
4581 	block = ext4_count_free_clusters(sb);
4582 	ext4_free_blocks_count_set(sbi->s_es,
4583 				   EXT4_C2B(sbi, block));
4584 	ext4_superblock_csum_set(sb);
4585 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4586 				  GFP_KERNEL);
4587 	if (!err) {
4588 		unsigned long freei = ext4_count_free_inodes(sb);
4589 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4590 		ext4_superblock_csum_set(sb);
4591 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4592 					  GFP_KERNEL);
4593 	}
4594 	if (!err)
4595 		err = percpu_counter_init(&sbi->s_dirs_counter,
4596 					  ext4_count_dirs(sb), GFP_KERNEL);
4597 	if (!err)
4598 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4599 					  GFP_KERNEL);
4600 	if (!err)
4601 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4602 
4603 	if (err) {
4604 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4605 		goto failed_mount6;
4606 	}
4607 
4608 	if (ext4_has_feature_flex_bg(sb))
4609 		if (!ext4_fill_flex_info(sb)) {
4610 			ext4_msg(sb, KERN_ERR,
4611 			       "unable to initialize "
4612 			       "flex_bg meta info!");
4613 			goto failed_mount6;
4614 		}
4615 
4616 	err = ext4_register_li_request(sb, first_not_zeroed);
4617 	if (err)
4618 		goto failed_mount6;
4619 
4620 	err = ext4_register_sysfs(sb);
4621 	if (err)
4622 		goto failed_mount7;
4623 
4624 #ifdef CONFIG_QUOTA
4625 	/* Enable quota usage during mount. */
4626 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4627 		err = ext4_enable_quotas(sb);
4628 		if (err)
4629 			goto failed_mount8;
4630 	}
4631 #endif  /* CONFIG_QUOTA */
4632 
4633 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4634 	ext4_orphan_cleanup(sb, es);
4635 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4636 	if (needs_recovery) {
4637 		ext4_msg(sb, KERN_INFO, "recovery complete");
4638 		ext4_mark_recovery_complete(sb, es);
4639 	}
4640 	if (EXT4_SB(sb)->s_journal) {
4641 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4642 			descr = " journalled data mode";
4643 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4644 			descr = " ordered data mode";
4645 		else
4646 			descr = " writeback data mode";
4647 	} else
4648 		descr = "out journal";
4649 
4650 	if (test_opt(sb, DISCARD)) {
4651 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4652 		if (!blk_queue_discard(q))
4653 			ext4_msg(sb, KERN_WARNING,
4654 				 "mounting with \"discard\" option, but "
4655 				 "the device does not support discard");
4656 	}
4657 
4658 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4659 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4660 			 "Opts: %.*s%s%s", descr,
4661 			 (int) sizeof(sbi->s_es->s_mount_opts),
4662 			 sbi->s_es->s_mount_opts,
4663 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4664 
4665 	if (es->s_error_count)
4666 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4667 
4668 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4669 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4670 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4671 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4672 
4673 	kfree(orig_data);
4674 	return 0;
4675 
4676 cantfind_ext4:
4677 	if (!silent)
4678 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4679 	goto failed_mount;
4680 
4681 #ifdef CONFIG_QUOTA
4682 failed_mount8:
4683 	ext4_unregister_sysfs(sb);
4684 #endif
4685 failed_mount7:
4686 	ext4_unregister_li_request(sb);
4687 failed_mount6:
4688 	ext4_mb_release(sb);
4689 	if (sbi->s_flex_groups)
4690 		kvfree(sbi->s_flex_groups);
4691 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4692 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4693 	percpu_counter_destroy(&sbi->s_dirs_counter);
4694 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4695 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
4696 failed_mount5:
4697 	ext4_ext_release(sb);
4698 	ext4_release_system_zone(sb);
4699 failed_mount4a:
4700 	dput(sb->s_root);
4701 	sb->s_root = NULL;
4702 failed_mount4:
4703 	ext4_msg(sb, KERN_ERR, "mount failed");
4704 	if (EXT4_SB(sb)->rsv_conversion_wq)
4705 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4706 failed_mount_wq:
4707 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4708 	sbi->s_ea_inode_cache = NULL;
4709 
4710 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4711 	sbi->s_ea_block_cache = NULL;
4712 
4713 	if (sbi->s_journal) {
4714 		jbd2_journal_destroy(sbi->s_journal);
4715 		sbi->s_journal = NULL;
4716 	}
4717 failed_mount3a:
4718 	ext4_es_unregister_shrinker(sbi);
4719 failed_mount3:
4720 	del_timer_sync(&sbi->s_err_report);
4721 	if (sbi->s_mmp_tsk)
4722 		kthread_stop(sbi->s_mmp_tsk);
4723 failed_mount2:
4724 	for (i = 0; i < db_count; i++)
4725 		brelse(sbi->s_group_desc[i]);
4726 	kvfree(sbi->s_group_desc);
4727 failed_mount:
4728 	if (sbi->s_chksum_driver)
4729 		crypto_free_shash(sbi->s_chksum_driver);
4730 
4731 #ifdef CONFIG_UNICODE
4732 	utf8_unload(sbi->s_encoding);
4733 #endif
4734 
4735 #ifdef CONFIG_QUOTA
4736 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4737 		kfree(get_qf_name(sb, sbi, i));
4738 #endif
4739 	ext4_blkdev_remove(sbi);
4740 	brelse(bh);
4741 out_fail:
4742 	sb->s_fs_info = NULL;
4743 	kfree(sbi->s_blockgroup_lock);
4744 out_free_base:
4745 	kfree(sbi);
4746 	kfree(orig_data);
4747 	fs_put_dax(dax_dev);
4748 	return err ? err : ret;
4749 }
4750 
4751 /*
4752  * Setup any per-fs journal parameters now.  We'll do this both on
4753  * initial mount, once the journal has been initialised but before we've
4754  * done any recovery; and again on any subsequent remount.
4755  */
4756 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4757 {
4758 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4759 
4760 	journal->j_commit_interval = sbi->s_commit_interval;
4761 	journal->j_min_batch_time = sbi->s_min_batch_time;
4762 	journal->j_max_batch_time = sbi->s_max_batch_time;
4763 
4764 	write_lock(&journal->j_state_lock);
4765 	if (test_opt(sb, BARRIER))
4766 		journal->j_flags |= JBD2_BARRIER;
4767 	else
4768 		journal->j_flags &= ~JBD2_BARRIER;
4769 	if (test_opt(sb, DATA_ERR_ABORT))
4770 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4771 	else
4772 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4773 	write_unlock(&journal->j_state_lock);
4774 }
4775 
4776 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4777 					     unsigned int journal_inum)
4778 {
4779 	struct inode *journal_inode;
4780 
4781 	/*
4782 	 * Test for the existence of a valid inode on disk.  Bad things
4783 	 * happen if we iget() an unused inode, as the subsequent iput()
4784 	 * will try to delete it.
4785 	 */
4786 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4787 	if (IS_ERR(journal_inode)) {
4788 		ext4_msg(sb, KERN_ERR, "no journal found");
4789 		return NULL;
4790 	}
4791 	if (!journal_inode->i_nlink) {
4792 		make_bad_inode(journal_inode);
4793 		iput(journal_inode);
4794 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4795 		return NULL;
4796 	}
4797 
4798 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4799 		  journal_inode, journal_inode->i_size);
4800 	if (!S_ISREG(journal_inode->i_mode)) {
4801 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4802 		iput(journal_inode);
4803 		return NULL;
4804 	}
4805 	return journal_inode;
4806 }
4807 
4808 static journal_t *ext4_get_journal(struct super_block *sb,
4809 				   unsigned int journal_inum)
4810 {
4811 	struct inode *journal_inode;
4812 	journal_t *journal;
4813 
4814 	BUG_ON(!ext4_has_feature_journal(sb));
4815 
4816 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4817 	if (!journal_inode)
4818 		return NULL;
4819 
4820 	journal = jbd2_journal_init_inode(journal_inode);
4821 	if (!journal) {
4822 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4823 		iput(journal_inode);
4824 		return NULL;
4825 	}
4826 	journal->j_private = sb;
4827 	ext4_init_journal_params(sb, journal);
4828 	return journal;
4829 }
4830 
4831 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4832 				       dev_t j_dev)
4833 {
4834 	struct buffer_head *bh;
4835 	journal_t *journal;
4836 	ext4_fsblk_t start;
4837 	ext4_fsblk_t len;
4838 	int hblock, blocksize;
4839 	ext4_fsblk_t sb_block;
4840 	unsigned long offset;
4841 	struct ext4_super_block *es;
4842 	struct block_device *bdev;
4843 
4844 	BUG_ON(!ext4_has_feature_journal(sb));
4845 
4846 	bdev = ext4_blkdev_get(j_dev, sb);
4847 	if (bdev == NULL)
4848 		return NULL;
4849 
4850 	blocksize = sb->s_blocksize;
4851 	hblock = bdev_logical_block_size(bdev);
4852 	if (blocksize < hblock) {
4853 		ext4_msg(sb, KERN_ERR,
4854 			"blocksize too small for journal device");
4855 		goto out_bdev;
4856 	}
4857 
4858 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4859 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4860 	set_blocksize(bdev, blocksize);
4861 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4862 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4863 		       "external journal");
4864 		goto out_bdev;
4865 	}
4866 
4867 	es = (struct ext4_super_block *) (bh->b_data + offset);
4868 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4869 	    !(le32_to_cpu(es->s_feature_incompat) &
4870 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4871 		ext4_msg(sb, KERN_ERR, "external journal has "
4872 					"bad superblock");
4873 		brelse(bh);
4874 		goto out_bdev;
4875 	}
4876 
4877 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4878 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4879 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4880 		ext4_msg(sb, KERN_ERR, "external journal has "
4881 				       "corrupt superblock");
4882 		brelse(bh);
4883 		goto out_bdev;
4884 	}
4885 
4886 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4887 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4888 		brelse(bh);
4889 		goto out_bdev;
4890 	}
4891 
4892 	len = ext4_blocks_count(es);
4893 	start = sb_block + 1;
4894 	brelse(bh);	/* we're done with the superblock */
4895 
4896 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4897 					start, len, blocksize);
4898 	if (!journal) {
4899 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4900 		goto out_bdev;
4901 	}
4902 	journal->j_private = sb;
4903 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4904 	wait_on_buffer(journal->j_sb_buffer);
4905 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4906 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4907 		goto out_journal;
4908 	}
4909 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4910 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4911 					"user (unsupported) - %d",
4912 			be32_to_cpu(journal->j_superblock->s_nr_users));
4913 		goto out_journal;
4914 	}
4915 	EXT4_SB(sb)->journal_bdev = bdev;
4916 	ext4_init_journal_params(sb, journal);
4917 	return journal;
4918 
4919 out_journal:
4920 	jbd2_journal_destroy(journal);
4921 out_bdev:
4922 	ext4_blkdev_put(bdev);
4923 	return NULL;
4924 }
4925 
4926 static int ext4_load_journal(struct super_block *sb,
4927 			     struct ext4_super_block *es,
4928 			     unsigned long journal_devnum)
4929 {
4930 	journal_t *journal;
4931 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4932 	dev_t journal_dev;
4933 	int err = 0;
4934 	int really_read_only;
4935 
4936 	BUG_ON(!ext4_has_feature_journal(sb));
4937 
4938 	if (journal_devnum &&
4939 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4940 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4941 			"numbers have changed");
4942 		journal_dev = new_decode_dev(journal_devnum);
4943 	} else
4944 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4945 
4946 	really_read_only = bdev_read_only(sb->s_bdev);
4947 
4948 	/*
4949 	 * Are we loading a blank journal or performing recovery after a
4950 	 * crash?  For recovery, we need to check in advance whether we
4951 	 * can get read-write access to the device.
4952 	 */
4953 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4954 		if (sb_rdonly(sb)) {
4955 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4956 					"required on readonly filesystem");
4957 			if (really_read_only) {
4958 				ext4_msg(sb, KERN_ERR, "write access "
4959 					"unavailable, cannot proceed "
4960 					"(try mounting with noload)");
4961 				return -EROFS;
4962 			}
4963 			ext4_msg(sb, KERN_INFO, "write access will "
4964 			       "be enabled during recovery");
4965 		}
4966 	}
4967 
4968 	if (journal_inum && journal_dev) {
4969 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4970 		       "and inode journals!");
4971 		return -EINVAL;
4972 	}
4973 
4974 	if (journal_inum) {
4975 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4976 			return -EINVAL;
4977 	} else {
4978 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4979 			return -EINVAL;
4980 	}
4981 
4982 	if (!(journal->j_flags & JBD2_BARRIER))
4983 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4984 
4985 	if (!ext4_has_feature_journal_needs_recovery(sb))
4986 		err = jbd2_journal_wipe(journal, !really_read_only);
4987 	if (!err) {
4988 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4989 		if (save)
4990 			memcpy(save, ((char *) es) +
4991 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4992 		err = jbd2_journal_load(journal);
4993 		if (save)
4994 			memcpy(((char *) es) + EXT4_S_ERR_START,
4995 			       save, EXT4_S_ERR_LEN);
4996 		kfree(save);
4997 	}
4998 
4999 	if (err) {
5000 		ext4_msg(sb, KERN_ERR, "error loading journal");
5001 		jbd2_journal_destroy(journal);
5002 		return err;
5003 	}
5004 
5005 	EXT4_SB(sb)->s_journal = journal;
5006 	ext4_clear_journal_err(sb, es);
5007 
5008 	if (!really_read_only && journal_devnum &&
5009 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5010 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5011 
5012 		/* Make sure we flush the recovery flag to disk. */
5013 		ext4_commit_super(sb, 1);
5014 	}
5015 
5016 	return 0;
5017 }
5018 
5019 static int ext4_commit_super(struct super_block *sb, int sync)
5020 {
5021 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
5022 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5023 	int error = 0;
5024 
5025 	if (!sbh || block_device_ejected(sb))
5026 		return error;
5027 
5028 	/*
5029 	 * The superblock bh should be mapped, but it might not be if the
5030 	 * device was hot-removed. Not much we can do but fail the I/O.
5031 	 */
5032 	if (!buffer_mapped(sbh))
5033 		return error;
5034 
5035 	/*
5036 	 * If the file system is mounted read-only, don't update the
5037 	 * superblock write time.  This avoids updating the superblock
5038 	 * write time when we are mounting the root file system
5039 	 * read/only but we need to replay the journal; at that point,
5040 	 * for people who are east of GMT and who make their clock
5041 	 * tick in localtime for Windows bug-for-bug compatibility,
5042 	 * the clock is set in the future, and this will cause e2fsck
5043 	 * to complain and force a full file system check.
5044 	 */
5045 	if (!(sb->s_flags & SB_RDONLY))
5046 		ext4_update_tstamp(es, s_wtime);
5047 	if (sb->s_bdev->bd_part)
5048 		es->s_kbytes_written =
5049 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5050 			    ((part_stat_read(sb->s_bdev->bd_part,
5051 					     sectors[STAT_WRITE]) -
5052 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
5053 	else
5054 		es->s_kbytes_written =
5055 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5056 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5057 		ext4_free_blocks_count_set(es,
5058 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5059 				&EXT4_SB(sb)->s_freeclusters_counter)));
5060 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5061 		es->s_free_inodes_count =
5062 			cpu_to_le32(percpu_counter_sum_positive(
5063 				&EXT4_SB(sb)->s_freeinodes_counter));
5064 	BUFFER_TRACE(sbh, "marking dirty");
5065 	ext4_superblock_csum_set(sb);
5066 	if (sync)
5067 		lock_buffer(sbh);
5068 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5069 		/*
5070 		 * Oh, dear.  A previous attempt to write the
5071 		 * superblock failed.  This could happen because the
5072 		 * USB device was yanked out.  Or it could happen to
5073 		 * be a transient write error and maybe the block will
5074 		 * be remapped.  Nothing we can do but to retry the
5075 		 * write and hope for the best.
5076 		 */
5077 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5078 		       "superblock detected");
5079 		clear_buffer_write_io_error(sbh);
5080 		set_buffer_uptodate(sbh);
5081 	}
5082 	mark_buffer_dirty(sbh);
5083 	if (sync) {
5084 		unlock_buffer(sbh);
5085 		error = __sync_dirty_buffer(sbh,
5086 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5087 		if (buffer_write_io_error(sbh)) {
5088 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5089 			       "superblock");
5090 			clear_buffer_write_io_error(sbh);
5091 			set_buffer_uptodate(sbh);
5092 		}
5093 	}
5094 	return error;
5095 }
5096 
5097 /*
5098  * Have we just finished recovery?  If so, and if we are mounting (or
5099  * remounting) the filesystem readonly, then we will end up with a
5100  * consistent fs on disk.  Record that fact.
5101  */
5102 static void ext4_mark_recovery_complete(struct super_block *sb,
5103 					struct ext4_super_block *es)
5104 {
5105 	journal_t *journal = EXT4_SB(sb)->s_journal;
5106 
5107 	if (!ext4_has_feature_journal(sb)) {
5108 		BUG_ON(journal != NULL);
5109 		return;
5110 	}
5111 	jbd2_journal_lock_updates(journal);
5112 	if (jbd2_journal_flush(journal) < 0)
5113 		goto out;
5114 
5115 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5116 		ext4_clear_feature_journal_needs_recovery(sb);
5117 		ext4_commit_super(sb, 1);
5118 	}
5119 
5120 out:
5121 	jbd2_journal_unlock_updates(journal);
5122 }
5123 
5124 /*
5125  * If we are mounting (or read-write remounting) a filesystem whose journal
5126  * has recorded an error from a previous lifetime, move that error to the
5127  * main filesystem now.
5128  */
5129 static void ext4_clear_journal_err(struct super_block *sb,
5130 				   struct ext4_super_block *es)
5131 {
5132 	journal_t *journal;
5133 	int j_errno;
5134 	const char *errstr;
5135 
5136 	BUG_ON(!ext4_has_feature_journal(sb));
5137 
5138 	journal = EXT4_SB(sb)->s_journal;
5139 
5140 	/*
5141 	 * Now check for any error status which may have been recorded in the
5142 	 * journal by a prior ext4_error() or ext4_abort()
5143 	 */
5144 
5145 	j_errno = jbd2_journal_errno(journal);
5146 	if (j_errno) {
5147 		char nbuf[16];
5148 
5149 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5150 		ext4_warning(sb, "Filesystem error recorded "
5151 			     "from previous mount: %s", errstr);
5152 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5153 
5154 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5155 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5156 		ext4_commit_super(sb, 1);
5157 
5158 		jbd2_journal_clear_err(journal);
5159 		jbd2_journal_update_sb_errno(journal);
5160 	}
5161 }
5162 
5163 /*
5164  * Force the running and committing transactions to commit,
5165  * and wait on the commit.
5166  */
5167 int ext4_force_commit(struct super_block *sb)
5168 {
5169 	journal_t *journal;
5170 
5171 	if (sb_rdonly(sb))
5172 		return 0;
5173 
5174 	journal = EXT4_SB(sb)->s_journal;
5175 	return ext4_journal_force_commit(journal);
5176 }
5177 
5178 static int ext4_sync_fs(struct super_block *sb, int wait)
5179 {
5180 	int ret = 0;
5181 	tid_t target;
5182 	bool needs_barrier = false;
5183 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5184 
5185 	if (unlikely(ext4_forced_shutdown(sbi)))
5186 		return 0;
5187 
5188 	trace_ext4_sync_fs(sb, wait);
5189 	flush_workqueue(sbi->rsv_conversion_wq);
5190 	/*
5191 	 * Writeback quota in non-journalled quota case - journalled quota has
5192 	 * no dirty dquots
5193 	 */
5194 	dquot_writeback_dquots(sb, -1);
5195 	/*
5196 	 * Data writeback is possible w/o journal transaction, so barrier must
5197 	 * being sent at the end of the function. But we can skip it if
5198 	 * transaction_commit will do it for us.
5199 	 */
5200 	if (sbi->s_journal) {
5201 		target = jbd2_get_latest_transaction(sbi->s_journal);
5202 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5203 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5204 			needs_barrier = true;
5205 
5206 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5207 			if (wait)
5208 				ret = jbd2_log_wait_commit(sbi->s_journal,
5209 							   target);
5210 		}
5211 	} else if (wait && test_opt(sb, BARRIER))
5212 		needs_barrier = true;
5213 	if (needs_barrier) {
5214 		int err;
5215 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5216 		if (!ret)
5217 			ret = err;
5218 	}
5219 
5220 	return ret;
5221 }
5222 
5223 /*
5224  * LVM calls this function before a (read-only) snapshot is created.  This
5225  * gives us a chance to flush the journal completely and mark the fs clean.
5226  *
5227  * Note that only this function cannot bring a filesystem to be in a clean
5228  * state independently. It relies on upper layer to stop all data & metadata
5229  * modifications.
5230  */
5231 static int ext4_freeze(struct super_block *sb)
5232 {
5233 	int error = 0;
5234 	journal_t *journal;
5235 
5236 	if (sb_rdonly(sb))
5237 		return 0;
5238 
5239 	journal = EXT4_SB(sb)->s_journal;
5240 
5241 	if (journal) {
5242 		/* Now we set up the journal barrier. */
5243 		jbd2_journal_lock_updates(journal);
5244 
5245 		/*
5246 		 * Don't clear the needs_recovery flag if we failed to
5247 		 * flush the journal.
5248 		 */
5249 		error = jbd2_journal_flush(journal);
5250 		if (error < 0)
5251 			goto out;
5252 
5253 		/* Journal blocked and flushed, clear needs_recovery flag. */
5254 		ext4_clear_feature_journal_needs_recovery(sb);
5255 	}
5256 
5257 	error = ext4_commit_super(sb, 1);
5258 out:
5259 	if (journal)
5260 		/* we rely on upper layer to stop further updates */
5261 		jbd2_journal_unlock_updates(journal);
5262 	return error;
5263 }
5264 
5265 /*
5266  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5267  * flag here, even though the filesystem is not technically dirty yet.
5268  */
5269 static int ext4_unfreeze(struct super_block *sb)
5270 {
5271 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5272 		return 0;
5273 
5274 	if (EXT4_SB(sb)->s_journal) {
5275 		/* Reset the needs_recovery flag before the fs is unlocked. */
5276 		ext4_set_feature_journal_needs_recovery(sb);
5277 	}
5278 
5279 	ext4_commit_super(sb, 1);
5280 	return 0;
5281 }
5282 
5283 /*
5284  * Structure to save mount options for ext4_remount's benefit
5285  */
5286 struct ext4_mount_options {
5287 	unsigned long s_mount_opt;
5288 	unsigned long s_mount_opt2;
5289 	kuid_t s_resuid;
5290 	kgid_t s_resgid;
5291 	unsigned long s_commit_interval;
5292 	u32 s_min_batch_time, s_max_batch_time;
5293 #ifdef CONFIG_QUOTA
5294 	int s_jquota_fmt;
5295 	char *s_qf_names[EXT4_MAXQUOTAS];
5296 #endif
5297 };
5298 
5299 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5300 {
5301 	struct ext4_super_block *es;
5302 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5303 	unsigned long old_sb_flags;
5304 	struct ext4_mount_options old_opts;
5305 	int enable_quota = 0;
5306 	ext4_group_t g;
5307 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5308 	int err = 0;
5309 #ifdef CONFIG_QUOTA
5310 	int i, j;
5311 	char *to_free[EXT4_MAXQUOTAS];
5312 #endif
5313 	char *orig_data = kstrdup(data, GFP_KERNEL);
5314 
5315 	if (data && !orig_data)
5316 		return -ENOMEM;
5317 
5318 	/* Store the original options */
5319 	old_sb_flags = sb->s_flags;
5320 	old_opts.s_mount_opt = sbi->s_mount_opt;
5321 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5322 	old_opts.s_resuid = sbi->s_resuid;
5323 	old_opts.s_resgid = sbi->s_resgid;
5324 	old_opts.s_commit_interval = sbi->s_commit_interval;
5325 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5326 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5327 #ifdef CONFIG_QUOTA
5328 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5329 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5330 		if (sbi->s_qf_names[i]) {
5331 			char *qf_name = get_qf_name(sb, sbi, i);
5332 
5333 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5334 			if (!old_opts.s_qf_names[i]) {
5335 				for (j = 0; j < i; j++)
5336 					kfree(old_opts.s_qf_names[j]);
5337 				kfree(orig_data);
5338 				return -ENOMEM;
5339 			}
5340 		} else
5341 			old_opts.s_qf_names[i] = NULL;
5342 #endif
5343 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5344 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5345 
5346 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5347 		err = -EINVAL;
5348 		goto restore_opts;
5349 	}
5350 
5351 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5352 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5353 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5354 			 "during remount not supported; ignoring");
5355 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5356 	}
5357 
5358 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5359 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5360 			ext4_msg(sb, KERN_ERR, "can't mount with "
5361 				 "both data=journal and delalloc");
5362 			err = -EINVAL;
5363 			goto restore_opts;
5364 		}
5365 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5366 			ext4_msg(sb, KERN_ERR, "can't mount with "
5367 				 "both data=journal and dioread_nolock");
5368 			err = -EINVAL;
5369 			goto restore_opts;
5370 		}
5371 		if (test_opt(sb, DAX)) {
5372 			ext4_msg(sb, KERN_ERR, "can't mount with "
5373 				 "both data=journal and dax");
5374 			err = -EINVAL;
5375 			goto restore_opts;
5376 		}
5377 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5378 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5379 			ext4_msg(sb, KERN_ERR, "can't mount with "
5380 				"journal_async_commit in data=ordered mode");
5381 			err = -EINVAL;
5382 			goto restore_opts;
5383 		}
5384 	}
5385 
5386 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5387 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5388 		err = -EINVAL;
5389 		goto restore_opts;
5390 	}
5391 
5392 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5393 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5394 			"dax flag with busy inodes while remounting");
5395 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5396 	}
5397 
5398 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5399 		ext4_abort(sb, "Abort forced by user");
5400 
5401 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5402 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5403 
5404 	es = sbi->s_es;
5405 
5406 	if (sbi->s_journal) {
5407 		ext4_init_journal_params(sb, sbi->s_journal);
5408 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5409 	}
5410 
5411 	if (*flags & SB_LAZYTIME)
5412 		sb->s_flags |= SB_LAZYTIME;
5413 
5414 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5415 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5416 			err = -EROFS;
5417 			goto restore_opts;
5418 		}
5419 
5420 		if (*flags & SB_RDONLY) {
5421 			err = sync_filesystem(sb);
5422 			if (err < 0)
5423 				goto restore_opts;
5424 			err = dquot_suspend(sb, -1);
5425 			if (err < 0)
5426 				goto restore_opts;
5427 
5428 			/*
5429 			 * First of all, the unconditional stuff we have to do
5430 			 * to disable replay of the journal when we next remount
5431 			 */
5432 			sb->s_flags |= SB_RDONLY;
5433 
5434 			/*
5435 			 * OK, test if we are remounting a valid rw partition
5436 			 * readonly, and if so set the rdonly flag and then
5437 			 * mark the partition as valid again.
5438 			 */
5439 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5440 			    (sbi->s_mount_state & EXT4_VALID_FS))
5441 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5442 
5443 			if (sbi->s_journal)
5444 				ext4_mark_recovery_complete(sb, es);
5445 			if (sbi->s_mmp_tsk)
5446 				kthread_stop(sbi->s_mmp_tsk);
5447 		} else {
5448 			/* Make sure we can mount this feature set readwrite */
5449 			if (ext4_has_feature_readonly(sb) ||
5450 			    !ext4_feature_set_ok(sb, 0)) {
5451 				err = -EROFS;
5452 				goto restore_opts;
5453 			}
5454 			/*
5455 			 * Make sure the group descriptor checksums
5456 			 * are sane.  If they aren't, refuse to remount r/w.
5457 			 */
5458 			for (g = 0; g < sbi->s_groups_count; g++) {
5459 				struct ext4_group_desc *gdp =
5460 					ext4_get_group_desc(sb, g, NULL);
5461 
5462 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5463 					ext4_msg(sb, KERN_ERR,
5464 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5465 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5466 					       le16_to_cpu(gdp->bg_checksum));
5467 					err = -EFSBADCRC;
5468 					goto restore_opts;
5469 				}
5470 			}
5471 
5472 			/*
5473 			 * If we have an unprocessed orphan list hanging
5474 			 * around from a previously readonly bdev mount,
5475 			 * require a full umount/remount for now.
5476 			 */
5477 			if (es->s_last_orphan) {
5478 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5479 				       "remount RDWR because of unprocessed "
5480 				       "orphan inode list.  Please "
5481 				       "umount/remount instead");
5482 				err = -EINVAL;
5483 				goto restore_opts;
5484 			}
5485 
5486 			/*
5487 			 * Mounting a RDONLY partition read-write, so reread
5488 			 * and store the current valid flag.  (It may have
5489 			 * been changed by e2fsck since we originally mounted
5490 			 * the partition.)
5491 			 */
5492 			if (sbi->s_journal)
5493 				ext4_clear_journal_err(sb, es);
5494 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5495 
5496 			err = ext4_setup_super(sb, es, 0);
5497 			if (err)
5498 				goto restore_opts;
5499 
5500 			sb->s_flags &= ~SB_RDONLY;
5501 			if (ext4_has_feature_mmp(sb))
5502 				if (ext4_multi_mount_protect(sb,
5503 						le64_to_cpu(es->s_mmp_block))) {
5504 					err = -EROFS;
5505 					goto restore_opts;
5506 				}
5507 			enable_quota = 1;
5508 		}
5509 	}
5510 
5511 	/*
5512 	 * Reinitialize lazy itable initialization thread based on
5513 	 * current settings
5514 	 */
5515 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5516 		ext4_unregister_li_request(sb);
5517 	else {
5518 		ext4_group_t first_not_zeroed;
5519 		first_not_zeroed = ext4_has_uninit_itable(sb);
5520 		ext4_register_li_request(sb, first_not_zeroed);
5521 	}
5522 
5523 	ext4_setup_system_zone(sb);
5524 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5525 		err = ext4_commit_super(sb, 1);
5526 		if (err)
5527 			goto restore_opts;
5528 	}
5529 
5530 #ifdef CONFIG_QUOTA
5531 	/* Release old quota file names */
5532 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5533 		kfree(old_opts.s_qf_names[i]);
5534 	if (enable_quota) {
5535 		if (sb_any_quota_suspended(sb))
5536 			dquot_resume(sb, -1);
5537 		else if (ext4_has_feature_quota(sb)) {
5538 			err = ext4_enable_quotas(sb);
5539 			if (err)
5540 				goto restore_opts;
5541 		}
5542 	}
5543 #endif
5544 
5545 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5546 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5547 	kfree(orig_data);
5548 	return 0;
5549 
5550 restore_opts:
5551 	sb->s_flags = old_sb_flags;
5552 	sbi->s_mount_opt = old_opts.s_mount_opt;
5553 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5554 	sbi->s_resuid = old_opts.s_resuid;
5555 	sbi->s_resgid = old_opts.s_resgid;
5556 	sbi->s_commit_interval = old_opts.s_commit_interval;
5557 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5558 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5559 #ifdef CONFIG_QUOTA
5560 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5561 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5562 		to_free[i] = get_qf_name(sb, sbi, i);
5563 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5564 	}
5565 	synchronize_rcu();
5566 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5567 		kfree(to_free[i]);
5568 #endif
5569 	kfree(orig_data);
5570 	return err;
5571 }
5572 
5573 #ifdef CONFIG_QUOTA
5574 static int ext4_statfs_project(struct super_block *sb,
5575 			       kprojid_t projid, struct kstatfs *buf)
5576 {
5577 	struct kqid qid;
5578 	struct dquot *dquot;
5579 	u64 limit;
5580 	u64 curblock;
5581 
5582 	qid = make_kqid_projid(projid);
5583 	dquot = dqget(sb, qid);
5584 	if (IS_ERR(dquot))
5585 		return PTR_ERR(dquot);
5586 	spin_lock(&dquot->dq_dqb_lock);
5587 
5588 	limit = 0;
5589 	if (dquot->dq_dqb.dqb_bsoftlimit &&
5590 	    (!limit || dquot->dq_dqb.dqb_bsoftlimit < limit))
5591 		limit = dquot->dq_dqb.dqb_bsoftlimit;
5592 	if (dquot->dq_dqb.dqb_bhardlimit &&
5593 	    (!limit || dquot->dq_dqb.dqb_bhardlimit < limit))
5594 		limit = dquot->dq_dqb.dqb_bhardlimit;
5595 	limit >>= sb->s_blocksize_bits;
5596 
5597 	if (limit && buf->f_blocks > limit) {
5598 		curblock = (dquot->dq_dqb.dqb_curspace +
5599 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5600 		buf->f_blocks = limit;
5601 		buf->f_bfree = buf->f_bavail =
5602 			(buf->f_blocks > curblock) ?
5603 			 (buf->f_blocks - curblock) : 0;
5604 	}
5605 
5606 	limit = 0;
5607 	if (dquot->dq_dqb.dqb_isoftlimit &&
5608 	    (!limit || dquot->dq_dqb.dqb_isoftlimit < limit))
5609 		limit = dquot->dq_dqb.dqb_isoftlimit;
5610 	if (dquot->dq_dqb.dqb_ihardlimit &&
5611 	    (!limit || dquot->dq_dqb.dqb_ihardlimit < limit))
5612 		limit = dquot->dq_dqb.dqb_ihardlimit;
5613 
5614 	if (limit && buf->f_files > limit) {
5615 		buf->f_files = limit;
5616 		buf->f_ffree =
5617 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5618 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5619 	}
5620 
5621 	spin_unlock(&dquot->dq_dqb_lock);
5622 	dqput(dquot);
5623 	return 0;
5624 }
5625 #endif
5626 
5627 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5628 {
5629 	struct super_block *sb = dentry->d_sb;
5630 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5631 	struct ext4_super_block *es = sbi->s_es;
5632 	ext4_fsblk_t overhead = 0, resv_blocks;
5633 	u64 fsid;
5634 	s64 bfree;
5635 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5636 
5637 	if (!test_opt(sb, MINIX_DF))
5638 		overhead = sbi->s_overhead;
5639 
5640 	buf->f_type = EXT4_SUPER_MAGIC;
5641 	buf->f_bsize = sb->s_blocksize;
5642 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5643 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5644 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5645 	/* prevent underflow in case that few free space is available */
5646 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5647 	buf->f_bavail = buf->f_bfree -
5648 			(ext4_r_blocks_count(es) + resv_blocks);
5649 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5650 		buf->f_bavail = 0;
5651 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5652 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5653 	buf->f_namelen = EXT4_NAME_LEN;
5654 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5655 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5656 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5657 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5658 
5659 #ifdef CONFIG_QUOTA
5660 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5661 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5662 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5663 #endif
5664 	return 0;
5665 }
5666 
5667 
5668 #ifdef CONFIG_QUOTA
5669 
5670 /*
5671  * Helper functions so that transaction is started before we acquire dqio_sem
5672  * to keep correct lock ordering of transaction > dqio_sem
5673  */
5674 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5675 {
5676 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5677 }
5678 
5679 static int ext4_write_dquot(struct dquot *dquot)
5680 {
5681 	int ret, err;
5682 	handle_t *handle;
5683 	struct inode *inode;
5684 
5685 	inode = dquot_to_inode(dquot);
5686 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5687 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5688 	if (IS_ERR(handle))
5689 		return PTR_ERR(handle);
5690 	ret = dquot_commit(dquot);
5691 	err = ext4_journal_stop(handle);
5692 	if (!ret)
5693 		ret = err;
5694 	return ret;
5695 }
5696 
5697 static int ext4_acquire_dquot(struct dquot *dquot)
5698 {
5699 	int ret, err;
5700 	handle_t *handle;
5701 
5702 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5703 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5704 	if (IS_ERR(handle))
5705 		return PTR_ERR(handle);
5706 	ret = dquot_acquire(dquot);
5707 	err = ext4_journal_stop(handle);
5708 	if (!ret)
5709 		ret = err;
5710 	return ret;
5711 }
5712 
5713 static int ext4_release_dquot(struct dquot *dquot)
5714 {
5715 	int ret, err;
5716 	handle_t *handle;
5717 
5718 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5719 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5720 	if (IS_ERR(handle)) {
5721 		/* Release dquot anyway to avoid endless cycle in dqput() */
5722 		dquot_release(dquot);
5723 		return PTR_ERR(handle);
5724 	}
5725 	ret = dquot_release(dquot);
5726 	err = ext4_journal_stop(handle);
5727 	if (!ret)
5728 		ret = err;
5729 	return ret;
5730 }
5731 
5732 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5733 {
5734 	struct super_block *sb = dquot->dq_sb;
5735 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5736 
5737 	/* Are we journaling quotas? */
5738 	if (ext4_has_feature_quota(sb) ||
5739 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5740 		dquot_mark_dquot_dirty(dquot);
5741 		return ext4_write_dquot(dquot);
5742 	} else {
5743 		return dquot_mark_dquot_dirty(dquot);
5744 	}
5745 }
5746 
5747 static int ext4_write_info(struct super_block *sb, int type)
5748 {
5749 	int ret, err;
5750 	handle_t *handle;
5751 
5752 	/* Data block + inode block */
5753 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5754 	if (IS_ERR(handle))
5755 		return PTR_ERR(handle);
5756 	ret = dquot_commit_info(sb, type);
5757 	err = ext4_journal_stop(handle);
5758 	if (!ret)
5759 		ret = err;
5760 	return ret;
5761 }
5762 
5763 /*
5764  * Turn on quotas during mount time - we need to find
5765  * the quota file and such...
5766  */
5767 static int ext4_quota_on_mount(struct super_block *sb, int type)
5768 {
5769 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5770 					EXT4_SB(sb)->s_jquota_fmt, type);
5771 }
5772 
5773 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5774 {
5775 	struct ext4_inode_info *ei = EXT4_I(inode);
5776 
5777 	/* The first argument of lockdep_set_subclass has to be
5778 	 * *exactly* the same as the argument to init_rwsem() --- in
5779 	 * this case, in init_once() --- or lockdep gets unhappy
5780 	 * because the name of the lock is set using the
5781 	 * stringification of the argument to init_rwsem().
5782 	 */
5783 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5784 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5785 }
5786 
5787 /*
5788  * Standard function to be called on quota_on
5789  */
5790 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5791 			 const struct path *path)
5792 {
5793 	int err;
5794 
5795 	if (!test_opt(sb, QUOTA))
5796 		return -EINVAL;
5797 
5798 	/* Quotafile not on the same filesystem? */
5799 	if (path->dentry->d_sb != sb)
5800 		return -EXDEV;
5801 	/* Journaling quota? */
5802 	if (EXT4_SB(sb)->s_qf_names[type]) {
5803 		/* Quotafile not in fs root? */
5804 		if (path->dentry->d_parent != sb->s_root)
5805 			ext4_msg(sb, KERN_WARNING,
5806 				"Quota file not on filesystem root. "
5807 				"Journaled quota will not work");
5808 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5809 	} else {
5810 		/*
5811 		 * Clear the flag just in case mount options changed since
5812 		 * last time.
5813 		 */
5814 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5815 	}
5816 
5817 	/*
5818 	 * When we journal data on quota file, we have to flush journal to see
5819 	 * all updates to the file when we bypass pagecache...
5820 	 */
5821 	if (EXT4_SB(sb)->s_journal &&
5822 	    ext4_should_journal_data(d_inode(path->dentry))) {
5823 		/*
5824 		 * We don't need to lock updates but journal_flush() could
5825 		 * otherwise be livelocked...
5826 		 */
5827 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5828 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5829 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5830 		if (err)
5831 			return err;
5832 	}
5833 
5834 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5835 	err = dquot_quota_on(sb, type, format_id, path);
5836 	if (err) {
5837 		lockdep_set_quota_inode(path->dentry->d_inode,
5838 					     I_DATA_SEM_NORMAL);
5839 	} else {
5840 		struct inode *inode = d_inode(path->dentry);
5841 		handle_t *handle;
5842 
5843 		/*
5844 		 * Set inode flags to prevent userspace from messing with quota
5845 		 * files. If this fails, we return success anyway since quotas
5846 		 * are already enabled and this is not a hard failure.
5847 		 */
5848 		inode_lock(inode);
5849 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5850 		if (IS_ERR(handle))
5851 			goto unlock_inode;
5852 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5853 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5854 				S_NOATIME | S_IMMUTABLE);
5855 		ext4_mark_inode_dirty(handle, inode);
5856 		ext4_journal_stop(handle);
5857 	unlock_inode:
5858 		inode_unlock(inode);
5859 	}
5860 	return err;
5861 }
5862 
5863 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5864 			     unsigned int flags)
5865 {
5866 	int err;
5867 	struct inode *qf_inode;
5868 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5869 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5870 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5871 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5872 	};
5873 
5874 	BUG_ON(!ext4_has_feature_quota(sb));
5875 
5876 	if (!qf_inums[type])
5877 		return -EPERM;
5878 
5879 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5880 	if (IS_ERR(qf_inode)) {
5881 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5882 		return PTR_ERR(qf_inode);
5883 	}
5884 
5885 	/* Don't account quota for quota files to avoid recursion */
5886 	qf_inode->i_flags |= S_NOQUOTA;
5887 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5888 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
5889 	if (err)
5890 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5891 	iput(qf_inode);
5892 
5893 	return err;
5894 }
5895 
5896 /* Enable usage tracking for all quota types. */
5897 static int ext4_enable_quotas(struct super_block *sb)
5898 {
5899 	int type, err = 0;
5900 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5901 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5902 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5903 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5904 	};
5905 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5906 		test_opt(sb, USRQUOTA),
5907 		test_opt(sb, GRPQUOTA),
5908 		test_opt(sb, PRJQUOTA),
5909 	};
5910 
5911 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5912 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5913 		if (qf_inums[type]) {
5914 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5915 				DQUOT_USAGE_ENABLED |
5916 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5917 			if (err) {
5918 				ext4_warning(sb,
5919 					"Failed to enable quota tracking "
5920 					"(type=%d, err=%d). Please run "
5921 					"e2fsck to fix.", type, err);
5922 				for (type--; type >= 0; type--)
5923 					dquot_quota_off(sb, type);
5924 
5925 				return err;
5926 			}
5927 		}
5928 	}
5929 	return 0;
5930 }
5931 
5932 static int ext4_quota_off(struct super_block *sb, int type)
5933 {
5934 	struct inode *inode = sb_dqopt(sb)->files[type];
5935 	handle_t *handle;
5936 	int err;
5937 
5938 	/* Force all delayed allocation blocks to be allocated.
5939 	 * Caller already holds s_umount sem */
5940 	if (test_opt(sb, DELALLOC))
5941 		sync_filesystem(sb);
5942 
5943 	if (!inode || !igrab(inode))
5944 		goto out;
5945 
5946 	err = dquot_quota_off(sb, type);
5947 	if (err || ext4_has_feature_quota(sb))
5948 		goto out_put;
5949 
5950 	inode_lock(inode);
5951 	/*
5952 	 * Update modification times of quota files when userspace can
5953 	 * start looking at them. If we fail, we return success anyway since
5954 	 * this is not a hard failure and quotas are already disabled.
5955 	 */
5956 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5957 	if (IS_ERR(handle))
5958 		goto out_unlock;
5959 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5960 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5961 	inode->i_mtime = inode->i_ctime = current_time(inode);
5962 	ext4_mark_inode_dirty(handle, inode);
5963 	ext4_journal_stop(handle);
5964 out_unlock:
5965 	inode_unlock(inode);
5966 out_put:
5967 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5968 	iput(inode);
5969 	return err;
5970 out:
5971 	return dquot_quota_off(sb, type);
5972 }
5973 
5974 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5975  * acquiring the locks... As quota files are never truncated and quota code
5976  * itself serializes the operations (and no one else should touch the files)
5977  * we don't have to be afraid of races */
5978 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5979 			       size_t len, loff_t off)
5980 {
5981 	struct inode *inode = sb_dqopt(sb)->files[type];
5982 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5983 	int offset = off & (sb->s_blocksize - 1);
5984 	int tocopy;
5985 	size_t toread;
5986 	struct buffer_head *bh;
5987 	loff_t i_size = i_size_read(inode);
5988 
5989 	if (off > i_size)
5990 		return 0;
5991 	if (off+len > i_size)
5992 		len = i_size-off;
5993 	toread = len;
5994 	while (toread > 0) {
5995 		tocopy = sb->s_blocksize - offset < toread ?
5996 				sb->s_blocksize - offset : toread;
5997 		bh = ext4_bread(NULL, inode, blk, 0);
5998 		if (IS_ERR(bh))
5999 			return PTR_ERR(bh);
6000 		if (!bh)	/* A hole? */
6001 			memset(data, 0, tocopy);
6002 		else
6003 			memcpy(data, bh->b_data+offset, tocopy);
6004 		brelse(bh);
6005 		offset = 0;
6006 		toread -= tocopy;
6007 		data += tocopy;
6008 		blk++;
6009 	}
6010 	return len;
6011 }
6012 
6013 /* Write to quotafile (we know the transaction is already started and has
6014  * enough credits) */
6015 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6016 				const char *data, size_t len, loff_t off)
6017 {
6018 	struct inode *inode = sb_dqopt(sb)->files[type];
6019 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6020 	int err, offset = off & (sb->s_blocksize - 1);
6021 	int retries = 0;
6022 	struct buffer_head *bh;
6023 	handle_t *handle = journal_current_handle();
6024 
6025 	if (EXT4_SB(sb)->s_journal && !handle) {
6026 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6027 			" cancelled because transaction is not started",
6028 			(unsigned long long)off, (unsigned long long)len);
6029 		return -EIO;
6030 	}
6031 	/*
6032 	 * Since we account only one data block in transaction credits,
6033 	 * then it is impossible to cross a block boundary.
6034 	 */
6035 	if (sb->s_blocksize - offset < len) {
6036 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6037 			" cancelled because not block aligned",
6038 			(unsigned long long)off, (unsigned long long)len);
6039 		return -EIO;
6040 	}
6041 
6042 	do {
6043 		bh = ext4_bread(handle, inode, blk,
6044 				EXT4_GET_BLOCKS_CREATE |
6045 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6046 	} while (PTR_ERR(bh) == -ENOSPC &&
6047 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6048 	if (IS_ERR(bh))
6049 		return PTR_ERR(bh);
6050 	if (!bh)
6051 		goto out;
6052 	BUFFER_TRACE(bh, "get write access");
6053 	err = ext4_journal_get_write_access(handle, bh);
6054 	if (err) {
6055 		brelse(bh);
6056 		return err;
6057 	}
6058 	lock_buffer(bh);
6059 	memcpy(bh->b_data+offset, data, len);
6060 	flush_dcache_page(bh->b_page);
6061 	unlock_buffer(bh);
6062 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6063 	brelse(bh);
6064 out:
6065 	if (inode->i_size < off + len) {
6066 		i_size_write(inode, off + len);
6067 		EXT4_I(inode)->i_disksize = inode->i_size;
6068 		ext4_mark_inode_dirty(handle, inode);
6069 	}
6070 	return len;
6071 }
6072 #endif
6073 
6074 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6075 		       const char *dev_name, void *data)
6076 {
6077 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6078 }
6079 
6080 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6081 static inline void register_as_ext2(void)
6082 {
6083 	int err = register_filesystem(&ext2_fs_type);
6084 	if (err)
6085 		printk(KERN_WARNING
6086 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6087 }
6088 
6089 static inline void unregister_as_ext2(void)
6090 {
6091 	unregister_filesystem(&ext2_fs_type);
6092 }
6093 
6094 static inline int ext2_feature_set_ok(struct super_block *sb)
6095 {
6096 	if (ext4_has_unknown_ext2_incompat_features(sb))
6097 		return 0;
6098 	if (sb_rdonly(sb))
6099 		return 1;
6100 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6101 		return 0;
6102 	return 1;
6103 }
6104 #else
6105 static inline void register_as_ext2(void) { }
6106 static inline void unregister_as_ext2(void) { }
6107 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6108 #endif
6109 
6110 static inline void register_as_ext3(void)
6111 {
6112 	int err = register_filesystem(&ext3_fs_type);
6113 	if (err)
6114 		printk(KERN_WARNING
6115 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6116 }
6117 
6118 static inline void unregister_as_ext3(void)
6119 {
6120 	unregister_filesystem(&ext3_fs_type);
6121 }
6122 
6123 static inline int ext3_feature_set_ok(struct super_block *sb)
6124 {
6125 	if (ext4_has_unknown_ext3_incompat_features(sb))
6126 		return 0;
6127 	if (!ext4_has_feature_journal(sb))
6128 		return 0;
6129 	if (sb_rdonly(sb))
6130 		return 1;
6131 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6132 		return 0;
6133 	return 1;
6134 }
6135 
6136 static struct file_system_type ext4_fs_type = {
6137 	.owner		= THIS_MODULE,
6138 	.name		= "ext4",
6139 	.mount		= ext4_mount,
6140 	.kill_sb	= kill_block_super,
6141 	.fs_flags	= FS_REQUIRES_DEV,
6142 };
6143 MODULE_ALIAS_FS("ext4");
6144 
6145 /* Shared across all ext4 file systems */
6146 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6147 
6148 static int __init ext4_init_fs(void)
6149 {
6150 	int i, err;
6151 
6152 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6153 	ext4_li_info = NULL;
6154 	mutex_init(&ext4_li_mtx);
6155 
6156 	/* Build-time check for flags consistency */
6157 	ext4_check_flag_values();
6158 
6159 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6160 		init_waitqueue_head(&ext4__ioend_wq[i]);
6161 
6162 	err = ext4_init_es();
6163 	if (err)
6164 		return err;
6165 
6166 	err = ext4_init_pending();
6167 	if (err)
6168 		goto out7;
6169 
6170 	err = ext4_init_post_read_processing();
6171 	if (err)
6172 		goto out6;
6173 
6174 	err = ext4_init_pageio();
6175 	if (err)
6176 		goto out5;
6177 
6178 	err = ext4_init_system_zone();
6179 	if (err)
6180 		goto out4;
6181 
6182 	err = ext4_init_sysfs();
6183 	if (err)
6184 		goto out3;
6185 
6186 	err = ext4_init_mballoc();
6187 	if (err)
6188 		goto out2;
6189 	err = init_inodecache();
6190 	if (err)
6191 		goto out1;
6192 	register_as_ext3();
6193 	register_as_ext2();
6194 	err = register_filesystem(&ext4_fs_type);
6195 	if (err)
6196 		goto out;
6197 
6198 	return 0;
6199 out:
6200 	unregister_as_ext2();
6201 	unregister_as_ext3();
6202 	destroy_inodecache();
6203 out1:
6204 	ext4_exit_mballoc();
6205 out2:
6206 	ext4_exit_sysfs();
6207 out3:
6208 	ext4_exit_system_zone();
6209 out4:
6210 	ext4_exit_pageio();
6211 out5:
6212 	ext4_exit_post_read_processing();
6213 out6:
6214 	ext4_exit_pending();
6215 out7:
6216 	ext4_exit_es();
6217 
6218 	return err;
6219 }
6220 
6221 static void __exit ext4_exit_fs(void)
6222 {
6223 	ext4_destroy_lazyinit_thread();
6224 	unregister_as_ext2();
6225 	unregister_as_ext3();
6226 	unregister_filesystem(&ext4_fs_type);
6227 	destroy_inodecache();
6228 	ext4_exit_mballoc();
6229 	ext4_exit_sysfs();
6230 	ext4_exit_system_zone();
6231 	ext4_exit_pageio();
6232 	ext4_exit_post_read_processing();
6233 	ext4_exit_es();
6234 	ext4_exit_pending();
6235 }
6236 
6237 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6238 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6239 MODULE_LICENSE("GPL");
6240 MODULE_SOFTDEP("pre: crc32c");
6241 module_init(ext4_init_fs)
6242 module_exit(ext4_exit_fs)
6243