xref: /linux/fs/ext4/super.c (revision a8b70ccf10e38775785d9cb12ead916474549f99)
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 
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 
49 #include "ext4.h"
50 #include "ext4_extents.h"	/* Needed for trace points definition */
51 #include "ext4_jbd2.h"
52 #include "xattr.h"
53 #include "acl.h"
54 #include "mballoc.h"
55 #include "fsmap.h"
56 
57 #define CREATE_TRACE_POINTS
58 #include <trace/events/ext4.h>
59 
60 static struct ext4_lazy_init *ext4_li_info;
61 static struct mutex ext4_li_mtx;
62 static struct ratelimit_state ext4_mount_msg_ratelimit;
63 
64 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
65 			     unsigned long journal_devnum);
66 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
67 static int ext4_commit_super(struct super_block *sb, int sync);
68 static void ext4_mark_recovery_complete(struct super_block *sb,
69 					struct ext4_super_block *es);
70 static void ext4_clear_journal_err(struct super_block *sb,
71 				   struct ext4_super_block *es);
72 static int ext4_sync_fs(struct super_block *sb, int wait);
73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
75 static int ext4_unfreeze(struct super_block *sb);
76 static int ext4_freeze(struct super_block *sb);
77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
78 		       const char *dev_name, void *data);
79 static inline int ext2_feature_set_ok(struct super_block *sb);
80 static inline int ext3_feature_set_ok(struct super_block *sb);
81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 
88 /*
89  * Lock ordering
90  *
91  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
92  * i_mmap_rwsem (inode->i_mmap_rwsem)!
93  *
94  * page fault path:
95  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
96  *   page lock -> i_data_sem (rw)
97  *
98  * buffered write path:
99  * sb_start_write -> i_mutex -> mmap_sem
100  * sb_start_write -> i_mutex -> transaction start -> page lock ->
101  *   i_data_sem (rw)
102  *
103  * truncate:
104  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
105  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
106  *   i_data_sem (rw)
107  *
108  * direct IO:
109  * sb_start_write -> i_mutex -> mmap_sem
110  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
111  *
112  * writepages:
113  * transaction start -> page lock(s) -> i_data_sem (rw)
114  */
115 
116 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
117 static struct file_system_type ext2_fs_type = {
118 	.owner		= THIS_MODULE,
119 	.name		= "ext2",
120 	.mount		= ext4_mount,
121 	.kill_sb	= kill_block_super,
122 	.fs_flags	= FS_REQUIRES_DEV,
123 };
124 MODULE_ALIAS_FS("ext2");
125 MODULE_ALIAS("ext2");
126 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
127 #else
128 #define IS_EXT2_SB(sb) (0)
129 #endif
130 
131 
132 static struct file_system_type ext3_fs_type = {
133 	.owner		= THIS_MODULE,
134 	.name		= "ext3",
135 	.mount		= ext4_mount,
136 	.kill_sb	= kill_block_super,
137 	.fs_flags	= FS_REQUIRES_DEV,
138 };
139 MODULE_ALIAS_FS("ext3");
140 MODULE_ALIAS("ext3");
141 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
142 
143 static int ext4_verify_csum_type(struct super_block *sb,
144 				 struct ext4_super_block *es)
145 {
146 	if (!ext4_has_feature_metadata_csum(sb))
147 		return 1;
148 
149 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
150 }
151 
152 static __le32 ext4_superblock_csum(struct super_block *sb,
153 				   struct ext4_super_block *es)
154 {
155 	struct ext4_sb_info *sbi = EXT4_SB(sb);
156 	int offset = offsetof(struct ext4_super_block, s_checksum);
157 	__u32 csum;
158 
159 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
160 
161 	return cpu_to_le32(csum);
162 }
163 
164 static int ext4_superblock_csum_verify(struct super_block *sb,
165 				       struct ext4_super_block *es)
166 {
167 	if (!ext4_has_metadata_csum(sb))
168 		return 1;
169 
170 	return es->s_checksum == ext4_superblock_csum(sb, es);
171 }
172 
173 void ext4_superblock_csum_set(struct super_block *sb)
174 {
175 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
176 
177 	if (!ext4_has_metadata_csum(sb))
178 		return;
179 
180 	es->s_checksum = ext4_superblock_csum(sb, es);
181 }
182 
183 void *ext4_kvmalloc(size_t size, gfp_t flags)
184 {
185 	void *ret;
186 
187 	ret = kmalloc(size, flags | __GFP_NOWARN);
188 	if (!ret)
189 		ret = __vmalloc(size, flags, PAGE_KERNEL);
190 	return ret;
191 }
192 
193 void *ext4_kvzalloc(size_t size, gfp_t flags)
194 {
195 	void *ret;
196 
197 	ret = kzalloc(size, flags | __GFP_NOWARN);
198 	if (!ret)
199 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
200 	return ret;
201 }
202 
203 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
204 			       struct ext4_group_desc *bg)
205 {
206 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
207 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
208 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
209 }
210 
211 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
212 			       struct ext4_group_desc *bg)
213 {
214 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
215 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
216 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
217 }
218 
219 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
220 			      struct ext4_group_desc *bg)
221 {
222 	return le32_to_cpu(bg->bg_inode_table_lo) |
223 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
224 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
225 }
226 
227 __u32 ext4_free_group_clusters(struct super_block *sb,
228 			       struct ext4_group_desc *bg)
229 {
230 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
231 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
232 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
233 }
234 
235 __u32 ext4_free_inodes_count(struct super_block *sb,
236 			      struct ext4_group_desc *bg)
237 {
238 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
239 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
240 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
241 }
242 
243 __u32 ext4_used_dirs_count(struct super_block *sb,
244 			      struct ext4_group_desc *bg)
245 {
246 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
247 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
248 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
249 }
250 
251 __u32 ext4_itable_unused_count(struct super_block *sb,
252 			      struct ext4_group_desc *bg)
253 {
254 	return le16_to_cpu(bg->bg_itable_unused_lo) |
255 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
256 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
257 }
258 
259 void ext4_block_bitmap_set(struct super_block *sb,
260 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
261 {
262 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
263 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
264 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
265 }
266 
267 void ext4_inode_bitmap_set(struct super_block *sb,
268 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
269 {
270 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
271 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
272 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
273 }
274 
275 void ext4_inode_table_set(struct super_block *sb,
276 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
277 {
278 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
279 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
280 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
281 }
282 
283 void ext4_free_group_clusters_set(struct super_block *sb,
284 				  struct ext4_group_desc *bg, __u32 count)
285 {
286 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
287 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
288 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
289 }
290 
291 void ext4_free_inodes_set(struct super_block *sb,
292 			  struct ext4_group_desc *bg, __u32 count)
293 {
294 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
295 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
296 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
297 }
298 
299 void ext4_used_dirs_set(struct super_block *sb,
300 			  struct ext4_group_desc *bg, __u32 count)
301 {
302 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
303 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
304 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
305 }
306 
307 void ext4_itable_unused_set(struct super_block *sb,
308 			  struct ext4_group_desc *bg, __u32 count)
309 {
310 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
311 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
312 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
313 }
314 
315 
316 static void __save_error_info(struct super_block *sb, const char *func,
317 			    unsigned int line)
318 {
319 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
320 
321 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
322 	if (bdev_read_only(sb->s_bdev))
323 		return;
324 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
325 	es->s_last_error_time = cpu_to_le32(get_seconds());
326 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
327 	es->s_last_error_line = cpu_to_le32(line);
328 	if (!es->s_first_error_time) {
329 		es->s_first_error_time = es->s_last_error_time;
330 		strncpy(es->s_first_error_func, func,
331 			sizeof(es->s_first_error_func));
332 		es->s_first_error_line = cpu_to_le32(line);
333 		es->s_first_error_ino = es->s_last_error_ino;
334 		es->s_first_error_block = es->s_last_error_block;
335 	}
336 	/*
337 	 * Start the daily error reporting function if it hasn't been
338 	 * started already
339 	 */
340 	if (!es->s_error_count)
341 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
342 	le32_add_cpu(&es->s_error_count, 1);
343 }
344 
345 static void save_error_info(struct super_block *sb, const char *func,
346 			    unsigned int line)
347 {
348 	__save_error_info(sb, func, line);
349 	ext4_commit_super(sb, 1);
350 }
351 
352 /*
353  * The del_gendisk() function uninitializes the disk-specific data
354  * structures, including the bdi structure, without telling anyone
355  * else.  Once this happens, any attempt to call mark_buffer_dirty()
356  * (for example, by ext4_commit_super), will cause a kernel OOPS.
357  * This is a kludge to prevent these oops until we can put in a proper
358  * hook in del_gendisk() to inform the VFS and file system layers.
359  */
360 static int block_device_ejected(struct super_block *sb)
361 {
362 	struct inode *bd_inode = sb->s_bdev->bd_inode;
363 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
364 
365 	return bdi->dev == NULL;
366 }
367 
368 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
369 {
370 	struct super_block		*sb = journal->j_private;
371 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
372 	int				error = is_journal_aborted(journal);
373 	struct ext4_journal_cb_entry	*jce;
374 
375 	BUG_ON(txn->t_state == T_FINISHED);
376 
377 	ext4_process_freed_data(sb, txn->t_tid);
378 
379 	spin_lock(&sbi->s_md_lock);
380 	while (!list_empty(&txn->t_private_list)) {
381 		jce = list_entry(txn->t_private_list.next,
382 				 struct ext4_journal_cb_entry, jce_list);
383 		list_del_init(&jce->jce_list);
384 		spin_unlock(&sbi->s_md_lock);
385 		jce->jce_func(sb, jce, error);
386 		spin_lock(&sbi->s_md_lock);
387 	}
388 	spin_unlock(&sbi->s_md_lock);
389 }
390 
391 /* Deal with the reporting of failure conditions on a filesystem such as
392  * inconsistencies detected or read IO failures.
393  *
394  * On ext2, we can store the error state of the filesystem in the
395  * superblock.  That is not possible on ext4, because we may have other
396  * write ordering constraints on the superblock which prevent us from
397  * writing it out straight away; and given that the journal is about to
398  * be aborted, we can't rely on the current, or future, transactions to
399  * write out the superblock safely.
400  *
401  * We'll just use the jbd2_journal_abort() error code to record an error in
402  * the journal instead.  On recovery, the journal will complain about
403  * that error until we've noted it down and cleared it.
404  */
405 
406 static void ext4_handle_error(struct super_block *sb)
407 {
408 	if (sb_rdonly(sb))
409 		return;
410 
411 	if (!test_opt(sb, ERRORS_CONT)) {
412 		journal_t *journal = EXT4_SB(sb)->s_journal;
413 
414 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
415 		if (journal)
416 			jbd2_journal_abort(journal, -EIO);
417 	}
418 	if (test_opt(sb, ERRORS_RO)) {
419 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
420 		/*
421 		 * Make sure updated value of ->s_mount_flags will be visible
422 		 * before ->s_flags update
423 		 */
424 		smp_wmb();
425 		sb->s_flags |= SB_RDONLY;
426 	}
427 	if (test_opt(sb, ERRORS_PANIC)) {
428 		if (EXT4_SB(sb)->s_journal &&
429 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
430 			return;
431 		panic("EXT4-fs (device %s): panic forced after error\n",
432 			sb->s_id);
433 	}
434 }
435 
436 #define ext4_error_ratelimit(sb)					\
437 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
438 			     "EXT4-fs error")
439 
440 void __ext4_error(struct super_block *sb, const char *function,
441 		  unsigned int line, const char *fmt, ...)
442 {
443 	struct va_format vaf;
444 	va_list args;
445 
446 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
447 		return;
448 
449 	trace_ext4_error(sb, function, line);
450 	if (ext4_error_ratelimit(sb)) {
451 		va_start(args, fmt);
452 		vaf.fmt = fmt;
453 		vaf.va = &args;
454 		printk(KERN_CRIT
455 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
456 		       sb->s_id, function, line, current->comm, &vaf);
457 		va_end(args);
458 	}
459 	save_error_info(sb, function, line);
460 	ext4_handle_error(sb);
461 }
462 
463 void __ext4_error_inode(struct inode *inode, const char *function,
464 			unsigned int line, ext4_fsblk_t block,
465 			const char *fmt, ...)
466 {
467 	va_list args;
468 	struct va_format vaf;
469 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
470 
471 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
472 		return;
473 
474 	trace_ext4_error(inode->i_sb, function, line);
475 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
476 	es->s_last_error_block = cpu_to_le64(block);
477 	if (ext4_error_ratelimit(inode->i_sb)) {
478 		va_start(args, fmt);
479 		vaf.fmt = fmt;
480 		vaf.va = &args;
481 		if (block)
482 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
483 			       "inode #%lu: block %llu: comm %s: %pV\n",
484 			       inode->i_sb->s_id, function, line, inode->i_ino,
485 			       block, current->comm, &vaf);
486 		else
487 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
488 			       "inode #%lu: comm %s: %pV\n",
489 			       inode->i_sb->s_id, function, line, inode->i_ino,
490 			       current->comm, &vaf);
491 		va_end(args);
492 	}
493 	save_error_info(inode->i_sb, function, line);
494 	ext4_handle_error(inode->i_sb);
495 }
496 
497 void __ext4_error_file(struct file *file, const char *function,
498 		       unsigned int line, ext4_fsblk_t block,
499 		       const char *fmt, ...)
500 {
501 	va_list args;
502 	struct va_format vaf;
503 	struct ext4_super_block *es;
504 	struct inode *inode = file_inode(file);
505 	char pathname[80], *path;
506 
507 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
508 		return;
509 
510 	trace_ext4_error(inode->i_sb, function, line);
511 	es = EXT4_SB(inode->i_sb)->s_es;
512 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
513 	if (ext4_error_ratelimit(inode->i_sb)) {
514 		path = file_path(file, pathname, sizeof(pathname));
515 		if (IS_ERR(path))
516 			path = "(unknown)";
517 		va_start(args, fmt);
518 		vaf.fmt = fmt;
519 		vaf.va = &args;
520 		if (block)
521 			printk(KERN_CRIT
522 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
523 			       "block %llu: comm %s: path %s: %pV\n",
524 			       inode->i_sb->s_id, function, line, inode->i_ino,
525 			       block, current->comm, path, &vaf);
526 		else
527 			printk(KERN_CRIT
528 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
529 			       "comm %s: path %s: %pV\n",
530 			       inode->i_sb->s_id, function, line, inode->i_ino,
531 			       current->comm, path, &vaf);
532 		va_end(args);
533 	}
534 	save_error_info(inode->i_sb, function, line);
535 	ext4_handle_error(inode->i_sb);
536 }
537 
538 const char *ext4_decode_error(struct super_block *sb, int errno,
539 			      char nbuf[16])
540 {
541 	char *errstr = NULL;
542 
543 	switch (errno) {
544 	case -EFSCORRUPTED:
545 		errstr = "Corrupt filesystem";
546 		break;
547 	case -EFSBADCRC:
548 		errstr = "Filesystem failed CRC";
549 		break;
550 	case -EIO:
551 		errstr = "IO failure";
552 		break;
553 	case -ENOMEM:
554 		errstr = "Out of memory";
555 		break;
556 	case -EROFS:
557 		if (!sb || (EXT4_SB(sb)->s_journal &&
558 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
559 			errstr = "Journal has aborted";
560 		else
561 			errstr = "Readonly filesystem";
562 		break;
563 	default:
564 		/* If the caller passed in an extra buffer for unknown
565 		 * errors, textualise them now.  Else we just return
566 		 * NULL. */
567 		if (nbuf) {
568 			/* Check for truncated error codes... */
569 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
570 				errstr = nbuf;
571 		}
572 		break;
573 	}
574 
575 	return errstr;
576 }
577 
578 /* __ext4_std_error decodes expected errors from journaling functions
579  * automatically and invokes the appropriate error response.  */
580 
581 void __ext4_std_error(struct super_block *sb, const char *function,
582 		      unsigned int line, int errno)
583 {
584 	char nbuf[16];
585 	const char *errstr;
586 
587 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
588 		return;
589 
590 	/* Special case: if the error is EROFS, and we're not already
591 	 * inside a transaction, then there's really no point in logging
592 	 * an error. */
593 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
594 		return;
595 
596 	if (ext4_error_ratelimit(sb)) {
597 		errstr = ext4_decode_error(sb, errno, nbuf);
598 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
599 		       sb->s_id, function, line, errstr);
600 	}
601 
602 	save_error_info(sb, function, line);
603 	ext4_handle_error(sb);
604 }
605 
606 /*
607  * ext4_abort is a much stronger failure handler than ext4_error.  The
608  * abort function may be used to deal with unrecoverable failures such
609  * as journal IO errors or ENOMEM at a critical moment in log management.
610  *
611  * We unconditionally force the filesystem into an ABORT|READONLY state,
612  * unless the error response on the fs has been set to panic in which
613  * case we take the easy way out and panic immediately.
614  */
615 
616 void __ext4_abort(struct super_block *sb, const char *function,
617 		unsigned int line, const char *fmt, ...)
618 {
619 	struct va_format vaf;
620 	va_list args;
621 
622 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
623 		return;
624 
625 	save_error_info(sb, function, line);
626 	va_start(args, fmt);
627 	vaf.fmt = fmt;
628 	vaf.va = &args;
629 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
630 	       sb->s_id, function, line, &vaf);
631 	va_end(args);
632 
633 	if (sb_rdonly(sb) == 0) {
634 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
635 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
636 		/*
637 		 * Make sure updated value of ->s_mount_flags will be visible
638 		 * before ->s_flags update
639 		 */
640 		smp_wmb();
641 		sb->s_flags |= SB_RDONLY;
642 		if (EXT4_SB(sb)->s_journal)
643 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
644 		save_error_info(sb, function, line);
645 	}
646 	if (test_opt(sb, ERRORS_PANIC)) {
647 		if (EXT4_SB(sb)->s_journal &&
648 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
649 			return;
650 		panic("EXT4-fs panic from previous error\n");
651 	}
652 }
653 
654 void __ext4_msg(struct super_block *sb,
655 		const char *prefix, const char *fmt, ...)
656 {
657 	struct va_format vaf;
658 	va_list args;
659 
660 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
661 		return;
662 
663 	va_start(args, fmt);
664 	vaf.fmt = fmt;
665 	vaf.va = &args;
666 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
667 	va_end(args);
668 }
669 
670 #define ext4_warning_ratelimit(sb)					\
671 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
672 			     "EXT4-fs warning")
673 
674 void __ext4_warning(struct super_block *sb, const char *function,
675 		    unsigned int line, const char *fmt, ...)
676 {
677 	struct va_format vaf;
678 	va_list args;
679 
680 	if (!ext4_warning_ratelimit(sb))
681 		return;
682 
683 	va_start(args, fmt);
684 	vaf.fmt = fmt;
685 	vaf.va = &args;
686 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
687 	       sb->s_id, function, line, &vaf);
688 	va_end(args);
689 }
690 
691 void __ext4_warning_inode(const struct inode *inode, const char *function,
692 			  unsigned int line, const char *fmt, ...)
693 {
694 	struct va_format vaf;
695 	va_list args;
696 
697 	if (!ext4_warning_ratelimit(inode->i_sb))
698 		return;
699 
700 	va_start(args, fmt);
701 	vaf.fmt = fmt;
702 	vaf.va = &args;
703 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
704 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
705 	       function, line, inode->i_ino, current->comm, &vaf);
706 	va_end(args);
707 }
708 
709 void __ext4_grp_locked_error(const char *function, unsigned int line,
710 			     struct super_block *sb, ext4_group_t grp,
711 			     unsigned long ino, ext4_fsblk_t block,
712 			     const char *fmt, ...)
713 __releases(bitlock)
714 __acquires(bitlock)
715 {
716 	struct va_format vaf;
717 	va_list args;
718 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
719 
720 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
721 		return;
722 
723 	trace_ext4_error(sb, function, line);
724 	es->s_last_error_ino = cpu_to_le32(ino);
725 	es->s_last_error_block = cpu_to_le64(block);
726 	__save_error_info(sb, function, line);
727 
728 	if (ext4_error_ratelimit(sb)) {
729 		va_start(args, fmt);
730 		vaf.fmt = fmt;
731 		vaf.va = &args;
732 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
733 		       sb->s_id, function, line, grp);
734 		if (ino)
735 			printk(KERN_CONT "inode %lu: ", ino);
736 		if (block)
737 			printk(KERN_CONT "block %llu:",
738 			       (unsigned long long) block);
739 		printk(KERN_CONT "%pV\n", &vaf);
740 		va_end(args);
741 	}
742 
743 	if (test_opt(sb, ERRORS_CONT)) {
744 		ext4_commit_super(sb, 0);
745 		return;
746 	}
747 
748 	ext4_unlock_group(sb, grp);
749 	ext4_commit_super(sb, 1);
750 	ext4_handle_error(sb);
751 	/*
752 	 * We only get here in the ERRORS_RO case; relocking the group
753 	 * may be dangerous, but nothing bad will happen since the
754 	 * filesystem will have already been marked read/only and the
755 	 * journal has been aborted.  We return 1 as a hint to callers
756 	 * who might what to use the return value from
757 	 * ext4_grp_locked_error() to distinguish between the
758 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
759 	 * aggressively from the ext4 function in question, with a
760 	 * more appropriate error code.
761 	 */
762 	ext4_lock_group(sb, grp);
763 	return;
764 }
765 
766 void ext4_update_dynamic_rev(struct super_block *sb)
767 {
768 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
769 
770 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
771 		return;
772 
773 	ext4_warning(sb,
774 		     "updating to rev %d because of new feature flag, "
775 		     "running e2fsck is recommended",
776 		     EXT4_DYNAMIC_REV);
777 
778 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
779 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
780 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
781 	/* leave es->s_feature_*compat flags alone */
782 	/* es->s_uuid will be set by e2fsck if empty */
783 
784 	/*
785 	 * The rest of the superblock fields should be zero, and if not it
786 	 * means they are likely already in use, so leave them alone.  We
787 	 * can leave it up to e2fsck to clean up any inconsistencies there.
788 	 */
789 }
790 
791 /*
792  * Open the external journal device
793  */
794 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
795 {
796 	struct block_device *bdev;
797 	char b[BDEVNAME_SIZE];
798 
799 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
800 	if (IS_ERR(bdev))
801 		goto fail;
802 	return bdev;
803 
804 fail:
805 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
806 			__bdevname(dev, b), PTR_ERR(bdev));
807 	return NULL;
808 }
809 
810 /*
811  * Release the journal device
812  */
813 static void ext4_blkdev_put(struct block_device *bdev)
814 {
815 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
816 }
817 
818 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
819 {
820 	struct block_device *bdev;
821 	bdev = sbi->journal_bdev;
822 	if (bdev) {
823 		ext4_blkdev_put(bdev);
824 		sbi->journal_bdev = NULL;
825 	}
826 }
827 
828 static inline struct inode *orphan_list_entry(struct list_head *l)
829 {
830 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
831 }
832 
833 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
834 {
835 	struct list_head *l;
836 
837 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
838 		 le32_to_cpu(sbi->s_es->s_last_orphan));
839 
840 	printk(KERN_ERR "sb_info orphan list:\n");
841 	list_for_each(l, &sbi->s_orphan) {
842 		struct inode *inode = orphan_list_entry(l);
843 		printk(KERN_ERR "  "
844 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
845 		       inode->i_sb->s_id, inode->i_ino, inode,
846 		       inode->i_mode, inode->i_nlink,
847 		       NEXT_ORPHAN(inode));
848 	}
849 }
850 
851 #ifdef CONFIG_QUOTA
852 static int ext4_quota_off(struct super_block *sb, int type);
853 
854 static inline void ext4_quota_off_umount(struct super_block *sb)
855 {
856 	int type;
857 
858 	/* Use our quota_off function to clear inode flags etc. */
859 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
860 		ext4_quota_off(sb, type);
861 }
862 #else
863 static inline void ext4_quota_off_umount(struct super_block *sb)
864 {
865 }
866 #endif
867 
868 static void ext4_put_super(struct super_block *sb)
869 {
870 	struct ext4_sb_info *sbi = EXT4_SB(sb);
871 	struct ext4_super_block *es = sbi->s_es;
872 	int aborted = 0;
873 	int i, err;
874 
875 	ext4_unregister_li_request(sb);
876 	ext4_quota_off_umount(sb);
877 
878 	destroy_workqueue(sbi->rsv_conversion_wq);
879 
880 	if (sbi->s_journal) {
881 		aborted = is_journal_aborted(sbi->s_journal);
882 		err = jbd2_journal_destroy(sbi->s_journal);
883 		sbi->s_journal = NULL;
884 		if ((err < 0) && !aborted)
885 			ext4_abort(sb, "Couldn't clean up the journal");
886 	}
887 
888 	ext4_unregister_sysfs(sb);
889 	ext4_es_unregister_shrinker(sbi);
890 	del_timer_sync(&sbi->s_err_report);
891 	ext4_release_system_zone(sb);
892 	ext4_mb_release(sb);
893 	ext4_ext_release(sb);
894 
895 	if (!sb_rdonly(sb) && !aborted) {
896 		ext4_clear_feature_journal_needs_recovery(sb);
897 		es->s_state = cpu_to_le16(sbi->s_mount_state);
898 	}
899 	if (!sb_rdonly(sb))
900 		ext4_commit_super(sb, 1);
901 
902 	for (i = 0; i < sbi->s_gdb_count; i++)
903 		brelse(sbi->s_group_desc[i]);
904 	kvfree(sbi->s_group_desc);
905 	kvfree(sbi->s_flex_groups);
906 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
907 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
908 	percpu_counter_destroy(&sbi->s_dirs_counter);
909 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
910 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
911 #ifdef CONFIG_QUOTA
912 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
913 		kfree(sbi->s_qf_names[i]);
914 #endif
915 
916 	/* Debugging code just in case the in-memory inode orphan list
917 	 * isn't empty.  The on-disk one can be non-empty if we've
918 	 * detected an error and taken the fs readonly, but the
919 	 * in-memory list had better be clean by this point. */
920 	if (!list_empty(&sbi->s_orphan))
921 		dump_orphan_list(sb, sbi);
922 	J_ASSERT(list_empty(&sbi->s_orphan));
923 
924 	sync_blockdev(sb->s_bdev);
925 	invalidate_bdev(sb->s_bdev);
926 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
927 		/*
928 		 * Invalidate the journal device's buffers.  We don't want them
929 		 * floating about in memory - the physical journal device may
930 		 * hotswapped, and it breaks the `ro-after' testing code.
931 		 */
932 		sync_blockdev(sbi->journal_bdev);
933 		invalidate_bdev(sbi->journal_bdev);
934 		ext4_blkdev_remove(sbi);
935 	}
936 	if (sbi->s_ea_inode_cache) {
937 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
938 		sbi->s_ea_inode_cache = NULL;
939 	}
940 	if (sbi->s_ea_block_cache) {
941 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
942 		sbi->s_ea_block_cache = NULL;
943 	}
944 	if (sbi->s_mmp_tsk)
945 		kthread_stop(sbi->s_mmp_tsk);
946 	brelse(sbi->s_sbh);
947 	sb->s_fs_info = NULL;
948 	/*
949 	 * Now that we are completely done shutting down the
950 	 * superblock, we need to actually destroy the kobject.
951 	 */
952 	kobject_put(&sbi->s_kobj);
953 	wait_for_completion(&sbi->s_kobj_unregister);
954 	if (sbi->s_chksum_driver)
955 		crypto_free_shash(sbi->s_chksum_driver);
956 	kfree(sbi->s_blockgroup_lock);
957 	fs_put_dax(sbi->s_daxdev);
958 	kfree(sbi);
959 }
960 
961 static struct kmem_cache *ext4_inode_cachep;
962 
963 /*
964  * Called inside transaction, so use GFP_NOFS
965  */
966 static struct inode *ext4_alloc_inode(struct super_block *sb)
967 {
968 	struct ext4_inode_info *ei;
969 
970 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
971 	if (!ei)
972 		return NULL;
973 
974 	inode_set_iversion(&ei->vfs_inode, 1);
975 	spin_lock_init(&ei->i_raw_lock);
976 	INIT_LIST_HEAD(&ei->i_prealloc_list);
977 	spin_lock_init(&ei->i_prealloc_lock);
978 	ext4_es_init_tree(&ei->i_es_tree);
979 	rwlock_init(&ei->i_es_lock);
980 	INIT_LIST_HEAD(&ei->i_es_list);
981 	ei->i_es_all_nr = 0;
982 	ei->i_es_shk_nr = 0;
983 	ei->i_es_shrink_lblk = 0;
984 	ei->i_reserved_data_blocks = 0;
985 	ei->i_da_metadata_calc_len = 0;
986 	ei->i_da_metadata_calc_last_lblock = 0;
987 	spin_lock_init(&(ei->i_block_reservation_lock));
988 #ifdef CONFIG_QUOTA
989 	ei->i_reserved_quota = 0;
990 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
991 #endif
992 	ei->jinode = NULL;
993 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
994 	spin_lock_init(&ei->i_completed_io_lock);
995 	ei->i_sync_tid = 0;
996 	ei->i_datasync_tid = 0;
997 	atomic_set(&ei->i_unwritten, 0);
998 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
999 	return &ei->vfs_inode;
1000 }
1001 
1002 static int ext4_drop_inode(struct inode *inode)
1003 {
1004 	int drop = generic_drop_inode(inode);
1005 
1006 	trace_ext4_drop_inode(inode, drop);
1007 	return drop;
1008 }
1009 
1010 static void ext4_i_callback(struct rcu_head *head)
1011 {
1012 	struct inode *inode = container_of(head, struct inode, i_rcu);
1013 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1014 }
1015 
1016 static void ext4_destroy_inode(struct inode *inode)
1017 {
1018 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1019 		ext4_msg(inode->i_sb, KERN_ERR,
1020 			 "Inode %lu (%p): orphan list check failed!",
1021 			 inode->i_ino, EXT4_I(inode));
1022 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1023 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1024 				true);
1025 		dump_stack();
1026 	}
1027 	call_rcu(&inode->i_rcu, ext4_i_callback);
1028 }
1029 
1030 static void init_once(void *foo)
1031 {
1032 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1033 
1034 	INIT_LIST_HEAD(&ei->i_orphan);
1035 	init_rwsem(&ei->xattr_sem);
1036 	init_rwsem(&ei->i_data_sem);
1037 	init_rwsem(&ei->i_mmap_sem);
1038 	inode_init_once(&ei->vfs_inode);
1039 }
1040 
1041 static int __init init_inodecache(void)
1042 {
1043 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1044 				sizeof(struct ext4_inode_info), 0,
1045 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1046 					SLAB_ACCOUNT),
1047 				offsetof(struct ext4_inode_info, i_data),
1048 				sizeof_field(struct ext4_inode_info, i_data),
1049 				init_once);
1050 	if (ext4_inode_cachep == NULL)
1051 		return -ENOMEM;
1052 	return 0;
1053 }
1054 
1055 static void destroy_inodecache(void)
1056 {
1057 	/*
1058 	 * Make sure all delayed rcu free inodes are flushed before we
1059 	 * destroy cache.
1060 	 */
1061 	rcu_barrier();
1062 	kmem_cache_destroy(ext4_inode_cachep);
1063 }
1064 
1065 void ext4_clear_inode(struct inode *inode)
1066 {
1067 	invalidate_inode_buffers(inode);
1068 	clear_inode(inode);
1069 	dquot_drop(inode);
1070 	ext4_discard_preallocations(inode);
1071 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1072 	if (EXT4_I(inode)->jinode) {
1073 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1074 					       EXT4_I(inode)->jinode);
1075 		jbd2_free_inode(EXT4_I(inode)->jinode);
1076 		EXT4_I(inode)->jinode = NULL;
1077 	}
1078 	fscrypt_put_encryption_info(inode);
1079 }
1080 
1081 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1082 					u64 ino, u32 generation)
1083 {
1084 	struct inode *inode;
1085 
1086 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1087 		return ERR_PTR(-ESTALE);
1088 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1089 		return ERR_PTR(-ESTALE);
1090 
1091 	/* iget isn't really right if the inode is currently unallocated!!
1092 	 *
1093 	 * ext4_read_inode will return a bad_inode if the inode had been
1094 	 * deleted, so we should be safe.
1095 	 *
1096 	 * Currently we don't know the generation for parent directory, so
1097 	 * a generation of 0 means "accept any"
1098 	 */
1099 	inode = ext4_iget_normal(sb, ino);
1100 	if (IS_ERR(inode))
1101 		return ERR_CAST(inode);
1102 	if (generation && inode->i_generation != generation) {
1103 		iput(inode);
1104 		return ERR_PTR(-ESTALE);
1105 	}
1106 
1107 	return inode;
1108 }
1109 
1110 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1111 					int fh_len, int fh_type)
1112 {
1113 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1114 				    ext4_nfs_get_inode);
1115 }
1116 
1117 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1118 					int fh_len, int fh_type)
1119 {
1120 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1121 				    ext4_nfs_get_inode);
1122 }
1123 
1124 /*
1125  * Try to release metadata pages (indirect blocks, directories) which are
1126  * mapped via the block device.  Since these pages could have journal heads
1127  * which would prevent try_to_free_buffers() from freeing them, we must use
1128  * jbd2 layer's try_to_free_buffers() function to release them.
1129  */
1130 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1131 				 gfp_t wait)
1132 {
1133 	journal_t *journal = EXT4_SB(sb)->s_journal;
1134 
1135 	WARN_ON(PageChecked(page));
1136 	if (!page_has_buffers(page))
1137 		return 0;
1138 	if (journal)
1139 		return jbd2_journal_try_to_free_buffers(journal, page,
1140 						wait & ~__GFP_DIRECT_RECLAIM);
1141 	return try_to_free_buffers(page);
1142 }
1143 
1144 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1145 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1146 {
1147 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1148 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1149 }
1150 
1151 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1152 							void *fs_data)
1153 {
1154 	handle_t *handle = fs_data;
1155 	int res, res2, credits, retries = 0;
1156 
1157 	/*
1158 	 * Encrypting the root directory is not allowed because e2fsck expects
1159 	 * lost+found to exist and be unencrypted, and encrypting the root
1160 	 * directory would imply encrypting the lost+found directory as well as
1161 	 * the filename "lost+found" itself.
1162 	 */
1163 	if (inode->i_ino == EXT4_ROOT_INO)
1164 		return -EPERM;
1165 
1166 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1167 		return -EINVAL;
1168 
1169 	res = ext4_convert_inline_data(inode);
1170 	if (res)
1171 		return res;
1172 
1173 	/*
1174 	 * If a journal handle was specified, then the encryption context is
1175 	 * being set on a new inode via inheritance and is part of a larger
1176 	 * transaction to create the inode.  Otherwise the encryption context is
1177 	 * being set on an existing inode in its own transaction.  Only in the
1178 	 * latter case should the "retry on ENOSPC" logic be used.
1179 	 */
1180 
1181 	if (handle) {
1182 		res = ext4_xattr_set_handle(handle, inode,
1183 					    EXT4_XATTR_INDEX_ENCRYPTION,
1184 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1185 					    ctx, len, 0);
1186 		if (!res) {
1187 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1188 			ext4_clear_inode_state(inode,
1189 					EXT4_STATE_MAY_INLINE_DATA);
1190 			/*
1191 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1192 			 * S_DAX may be disabled
1193 			 */
1194 			ext4_set_inode_flags(inode);
1195 		}
1196 		return res;
1197 	}
1198 
1199 	res = dquot_initialize(inode);
1200 	if (res)
1201 		return res;
1202 retry:
1203 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1204 				     &credits);
1205 	if (res)
1206 		return res;
1207 
1208 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1209 	if (IS_ERR(handle))
1210 		return PTR_ERR(handle);
1211 
1212 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1213 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1214 				    ctx, len, 0);
1215 	if (!res) {
1216 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1217 		/*
1218 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1219 		 * S_DAX may be disabled
1220 		 */
1221 		ext4_set_inode_flags(inode);
1222 		res = ext4_mark_inode_dirty(handle, inode);
1223 		if (res)
1224 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1225 	}
1226 	res2 = ext4_journal_stop(handle);
1227 
1228 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1229 		goto retry;
1230 	if (!res)
1231 		res = res2;
1232 	return res;
1233 }
1234 
1235 static bool ext4_dummy_context(struct inode *inode)
1236 {
1237 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1238 }
1239 
1240 static unsigned ext4_max_namelen(struct inode *inode)
1241 {
1242 	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1243 		EXT4_NAME_LEN;
1244 }
1245 
1246 static const struct fscrypt_operations ext4_cryptops = {
1247 	.key_prefix		= "ext4:",
1248 	.get_context		= ext4_get_context,
1249 	.set_context		= ext4_set_context,
1250 	.dummy_context		= ext4_dummy_context,
1251 	.empty_dir		= ext4_empty_dir,
1252 	.max_namelen		= ext4_max_namelen,
1253 };
1254 #endif
1255 
1256 #ifdef CONFIG_QUOTA
1257 static const char * const quotatypes[] = INITQFNAMES;
1258 #define QTYPE2NAME(t) (quotatypes[t])
1259 
1260 static int ext4_write_dquot(struct dquot *dquot);
1261 static int ext4_acquire_dquot(struct dquot *dquot);
1262 static int ext4_release_dquot(struct dquot *dquot);
1263 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1264 static int ext4_write_info(struct super_block *sb, int type);
1265 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1266 			 const struct path *path);
1267 static int ext4_quota_on_mount(struct super_block *sb, int type);
1268 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1269 			       size_t len, loff_t off);
1270 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1271 				const char *data, size_t len, loff_t off);
1272 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1273 			     unsigned int flags);
1274 static int ext4_enable_quotas(struct super_block *sb);
1275 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1276 
1277 static struct dquot **ext4_get_dquots(struct inode *inode)
1278 {
1279 	return EXT4_I(inode)->i_dquot;
1280 }
1281 
1282 static const struct dquot_operations ext4_quota_operations = {
1283 	.get_reserved_space	= ext4_get_reserved_space,
1284 	.write_dquot		= ext4_write_dquot,
1285 	.acquire_dquot		= ext4_acquire_dquot,
1286 	.release_dquot		= ext4_release_dquot,
1287 	.mark_dirty		= ext4_mark_dquot_dirty,
1288 	.write_info		= ext4_write_info,
1289 	.alloc_dquot		= dquot_alloc,
1290 	.destroy_dquot		= dquot_destroy,
1291 	.get_projid		= ext4_get_projid,
1292 	.get_inode_usage	= ext4_get_inode_usage,
1293 	.get_next_id		= ext4_get_next_id,
1294 };
1295 
1296 static const struct quotactl_ops ext4_qctl_operations = {
1297 	.quota_on	= ext4_quota_on,
1298 	.quota_off	= ext4_quota_off,
1299 	.quota_sync	= dquot_quota_sync,
1300 	.get_state	= dquot_get_state,
1301 	.set_info	= dquot_set_dqinfo,
1302 	.get_dqblk	= dquot_get_dqblk,
1303 	.set_dqblk	= dquot_set_dqblk,
1304 	.get_nextdqblk	= dquot_get_next_dqblk,
1305 };
1306 #endif
1307 
1308 static const struct super_operations ext4_sops = {
1309 	.alloc_inode	= ext4_alloc_inode,
1310 	.destroy_inode	= ext4_destroy_inode,
1311 	.write_inode	= ext4_write_inode,
1312 	.dirty_inode	= ext4_dirty_inode,
1313 	.drop_inode	= ext4_drop_inode,
1314 	.evict_inode	= ext4_evict_inode,
1315 	.put_super	= ext4_put_super,
1316 	.sync_fs	= ext4_sync_fs,
1317 	.freeze_fs	= ext4_freeze,
1318 	.unfreeze_fs	= ext4_unfreeze,
1319 	.statfs		= ext4_statfs,
1320 	.remount_fs	= ext4_remount,
1321 	.show_options	= ext4_show_options,
1322 #ifdef CONFIG_QUOTA
1323 	.quota_read	= ext4_quota_read,
1324 	.quota_write	= ext4_quota_write,
1325 	.get_dquots	= ext4_get_dquots,
1326 #endif
1327 	.bdev_try_to_free_page = bdev_try_to_free_page,
1328 };
1329 
1330 static const struct export_operations ext4_export_ops = {
1331 	.fh_to_dentry = ext4_fh_to_dentry,
1332 	.fh_to_parent = ext4_fh_to_parent,
1333 	.get_parent = ext4_get_parent,
1334 };
1335 
1336 enum {
1337 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1338 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1339 	Opt_nouid32, Opt_debug, Opt_removed,
1340 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1341 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1342 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1343 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1344 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1345 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1346 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1347 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1348 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1349 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1350 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1351 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1352 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1353 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1354 	Opt_dioread_nolock, Opt_dioread_lock,
1355 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1356 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1357 };
1358 
1359 static const match_table_t tokens = {
1360 	{Opt_bsd_df, "bsddf"},
1361 	{Opt_minix_df, "minixdf"},
1362 	{Opt_grpid, "grpid"},
1363 	{Opt_grpid, "bsdgroups"},
1364 	{Opt_nogrpid, "nogrpid"},
1365 	{Opt_nogrpid, "sysvgroups"},
1366 	{Opt_resgid, "resgid=%u"},
1367 	{Opt_resuid, "resuid=%u"},
1368 	{Opt_sb, "sb=%u"},
1369 	{Opt_err_cont, "errors=continue"},
1370 	{Opt_err_panic, "errors=panic"},
1371 	{Opt_err_ro, "errors=remount-ro"},
1372 	{Opt_nouid32, "nouid32"},
1373 	{Opt_debug, "debug"},
1374 	{Opt_removed, "oldalloc"},
1375 	{Opt_removed, "orlov"},
1376 	{Opt_user_xattr, "user_xattr"},
1377 	{Opt_nouser_xattr, "nouser_xattr"},
1378 	{Opt_acl, "acl"},
1379 	{Opt_noacl, "noacl"},
1380 	{Opt_noload, "norecovery"},
1381 	{Opt_noload, "noload"},
1382 	{Opt_removed, "nobh"},
1383 	{Opt_removed, "bh"},
1384 	{Opt_commit, "commit=%u"},
1385 	{Opt_min_batch_time, "min_batch_time=%u"},
1386 	{Opt_max_batch_time, "max_batch_time=%u"},
1387 	{Opt_journal_dev, "journal_dev=%u"},
1388 	{Opt_journal_path, "journal_path=%s"},
1389 	{Opt_journal_checksum, "journal_checksum"},
1390 	{Opt_nojournal_checksum, "nojournal_checksum"},
1391 	{Opt_journal_async_commit, "journal_async_commit"},
1392 	{Opt_abort, "abort"},
1393 	{Opt_data_journal, "data=journal"},
1394 	{Opt_data_ordered, "data=ordered"},
1395 	{Opt_data_writeback, "data=writeback"},
1396 	{Opt_data_err_abort, "data_err=abort"},
1397 	{Opt_data_err_ignore, "data_err=ignore"},
1398 	{Opt_offusrjquota, "usrjquota="},
1399 	{Opt_usrjquota, "usrjquota=%s"},
1400 	{Opt_offgrpjquota, "grpjquota="},
1401 	{Opt_grpjquota, "grpjquota=%s"},
1402 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1403 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1404 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1405 	{Opt_grpquota, "grpquota"},
1406 	{Opt_noquota, "noquota"},
1407 	{Opt_quota, "quota"},
1408 	{Opt_usrquota, "usrquota"},
1409 	{Opt_prjquota, "prjquota"},
1410 	{Opt_barrier, "barrier=%u"},
1411 	{Opt_barrier, "barrier"},
1412 	{Opt_nobarrier, "nobarrier"},
1413 	{Opt_i_version, "i_version"},
1414 	{Opt_dax, "dax"},
1415 	{Opt_stripe, "stripe=%u"},
1416 	{Opt_delalloc, "delalloc"},
1417 	{Opt_lazytime, "lazytime"},
1418 	{Opt_nolazytime, "nolazytime"},
1419 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1420 	{Opt_nodelalloc, "nodelalloc"},
1421 	{Opt_removed, "mblk_io_submit"},
1422 	{Opt_removed, "nomblk_io_submit"},
1423 	{Opt_block_validity, "block_validity"},
1424 	{Opt_noblock_validity, "noblock_validity"},
1425 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1426 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1427 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1428 	{Opt_auto_da_alloc, "auto_da_alloc"},
1429 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1430 	{Opt_dioread_nolock, "dioread_nolock"},
1431 	{Opt_dioread_lock, "dioread_lock"},
1432 	{Opt_discard, "discard"},
1433 	{Opt_nodiscard, "nodiscard"},
1434 	{Opt_init_itable, "init_itable=%u"},
1435 	{Opt_init_itable, "init_itable"},
1436 	{Opt_noinit_itable, "noinit_itable"},
1437 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1438 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1439 	{Opt_nombcache, "nombcache"},
1440 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1441 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1442 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1443 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1444 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1445 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1446 	{Opt_err, NULL},
1447 };
1448 
1449 static ext4_fsblk_t get_sb_block(void **data)
1450 {
1451 	ext4_fsblk_t	sb_block;
1452 	char		*options = (char *) *data;
1453 
1454 	if (!options || strncmp(options, "sb=", 3) != 0)
1455 		return 1;	/* Default location */
1456 
1457 	options += 3;
1458 	/* TODO: use simple_strtoll with >32bit ext4 */
1459 	sb_block = simple_strtoul(options, &options, 0);
1460 	if (*options && *options != ',') {
1461 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1462 		       (char *) *data);
1463 		return 1;
1464 	}
1465 	if (*options == ',')
1466 		options++;
1467 	*data = (void *) options;
1468 
1469 	return sb_block;
1470 }
1471 
1472 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1473 static const char deprecated_msg[] =
1474 	"Mount option \"%s\" will be removed by %s\n"
1475 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1476 
1477 #ifdef CONFIG_QUOTA
1478 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1479 {
1480 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1481 	char *qname;
1482 	int ret = -1;
1483 
1484 	if (sb_any_quota_loaded(sb) &&
1485 		!sbi->s_qf_names[qtype]) {
1486 		ext4_msg(sb, KERN_ERR,
1487 			"Cannot change journaled "
1488 			"quota options when quota turned on");
1489 		return -1;
1490 	}
1491 	if (ext4_has_feature_quota(sb)) {
1492 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1493 			 "ignored when QUOTA feature is enabled");
1494 		return 1;
1495 	}
1496 	qname = match_strdup(args);
1497 	if (!qname) {
1498 		ext4_msg(sb, KERN_ERR,
1499 			"Not enough memory for storing quotafile name");
1500 		return -1;
1501 	}
1502 	if (sbi->s_qf_names[qtype]) {
1503 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1504 			ret = 1;
1505 		else
1506 			ext4_msg(sb, KERN_ERR,
1507 				 "%s quota file already specified",
1508 				 QTYPE2NAME(qtype));
1509 		goto errout;
1510 	}
1511 	if (strchr(qname, '/')) {
1512 		ext4_msg(sb, KERN_ERR,
1513 			"quotafile must be on filesystem root");
1514 		goto errout;
1515 	}
1516 	sbi->s_qf_names[qtype] = qname;
1517 	set_opt(sb, QUOTA);
1518 	return 1;
1519 errout:
1520 	kfree(qname);
1521 	return ret;
1522 }
1523 
1524 static int clear_qf_name(struct super_block *sb, int qtype)
1525 {
1526 
1527 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1528 
1529 	if (sb_any_quota_loaded(sb) &&
1530 		sbi->s_qf_names[qtype]) {
1531 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1532 			" when quota turned on");
1533 		return -1;
1534 	}
1535 	kfree(sbi->s_qf_names[qtype]);
1536 	sbi->s_qf_names[qtype] = NULL;
1537 	return 1;
1538 }
1539 #endif
1540 
1541 #define MOPT_SET	0x0001
1542 #define MOPT_CLEAR	0x0002
1543 #define MOPT_NOSUPPORT	0x0004
1544 #define MOPT_EXPLICIT	0x0008
1545 #define MOPT_CLEAR_ERR	0x0010
1546 #define MOPT_GTE0	0x0020
1547 #ifdef CONFIG_QUOTA
1548 #define MOPT_Q		0
1549 #define MOPT_QFMT	0x0040
1550 #else
1551 #define MOPT_Q		MOPT_NOSUPPORT
1552 #define MOPT_QFMT	MOPT_NOSUPPORT
1553 #endif
1554 #define MOPT_DATAJ	0x0080
1555 #define MOPT_NO_EXT2	0x0100
1556 #define MOPT_NO_EXT3	0x0200
1557 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1558 #define MOPT_STRING	0x0400
1559 
1560 static const struct mount_opts {
1561 	int	token;
1562 	int	mount_opt;
1563 	int	flags;
1564 } ext4_mount_opts[] = {
1565 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1566 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1567 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1568 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1569 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1570 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1571 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1572 	 MOPT_EXT4_ONLY | MOPT_SET},
1573 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1574 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1575 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1576 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1577 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1578 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1579 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1580 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1581 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1582 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1583 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1584 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1585 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1586 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1587 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1588 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1589 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1590 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1591 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1592 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1593 	 MOPT_NO_EXT2},
1594 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1595 	 MOPT_NO_EXT2},
1596 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1597 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1598 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1599 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1600 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1601 	{Opt_commit, 0, MOPT_GTE0},
1602 	{Opt_max_batch_time, 0, MOPT_GTE0},
1603 	{Opt_min_batch_time, 0, MOPT_GTE0},
1604 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1605 	{Opt_init_itable, 0, MOPT_GTE0},
1606 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1607 	{Opt_stripe, 0, MOPT_GTE0},
1608 	{Opt_resuid, 0, MOPT_GTE0},
1609 	{Opt_resgid, 0, MOPT_GTE0},
1610 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1611 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1612 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1613 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1614 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1615 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1616 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1617 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1618 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1619 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1620 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1621 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1622 #else
1623 	{Opt_acl, 0, MOPT_NOSUPPORT},
1624 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1625 #endif
1626 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1627 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1628 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1629 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1630 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1631 							MOPT_SET | MOPT_Q},
1632 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1633 							MOPT_SET | MOPT_Q},
1634 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1635 							MOPT_SET | MOPT_Q},
1636 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1637 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1638 							MOPT_CLEAR | MOPT_Q},
1639 	{Opt_usrjquota, 0, MOPT_Q},
1640 	{Opt_grpjquota, 0, MOPT_Q},
1641 	{Opt_offusrjquota, 0, MOPT_Q},
1642 	{Opt_offgrpjquota, 0, MOPT_Q},
1643 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1644 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1645 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1646 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1647 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1648 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1649 	{Opt_err, 0, 0}
1650 };
1651 
1652 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1653 			    substring_t *args, unsigned long *journal_devnum,
1654 			    unsigned int *journal_ioprio, int is_remount)
1655 {
1656 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1657 	const struct mount_opts *m;
1658 	kuid_t uid;
1659 	kgid_t gid;
1660 	int arg = 0;
1661 
1662 #ifdef CONFIG_QUOTA
1663 	if (token == Opt_usrjquota)
1664 		return set_qf_name(sb, USRQUOTA, &args[0]);
1665 	else if (token == Opt_grpjquota)
1666 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1667 	else if (token == Opt_offusrjquota)
1668 		return clear_qf_name(sb, USRQUOTA);
1669 	else if (token == Opt_offgrpjquota)
1670 		return clear_qf_name(sb, GRPQUOTA);
1671 #endif
1672 	switch (token) {
1673 	case Opt_noacl:
1674 	case Opt_nouser_xattr:
1675 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1676 		break;
1677 	case Opt_sb:
1678 		return 1;	/* handled by get_sb_block() */
1679 	case Opt_removed:
1680 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1681 		return 1;
1682 	case Opt_abort:
1683 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1684 		return 1;
1685 	case Opt_i_version:
1686 		sb->s_flags |= SB_I_VERSION;
1687 		return 1;
1688 	case Opt_lazytime:
1689 		sb->s_flags |= SB_LAZYTIME;
1690 		return 1;
1691 	case Opt_nolazytime:
1692 		sb->s_flags &= ~SB_LAZYTIME;
1693 		return 1;
1694 	}
1695 
1696 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1697 		if (token == m->token)
1698 			break;
1699 
1700 	if (m->token == Opt_err) {
1701 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1702 			 "or missing value", opt);
1703 		return -1;
1704 	}
1705 
1706 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1707 		ext4_msg(sb, KERN_ERR,
1708 			 "Mount option \"%s\" incompatible with ext2", opt);
1709 		return -1;
1710 	}
1711 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1712 		ext4_msg(sb, KERN_ERR,
1713 			 "Mount option \"%s\" incompatible with ext3", opt);
1714 		return -1;
1715 	}
1716 
1717 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1718 		return -1;
1719 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1720 		return -1;
1721 	if (m->flags & MOPT_EXPLICIT) {
1722 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1723 			set_opt2(sb, EXPLICIT_DELALLOC);
1724 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1725 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1726 		} else
1727 			return -1;
1728 	}
1729 	if (m->flags & MOPT_CLEAR_ERR)
1730 		clear_opt(sb, ERRORS_MASK);
1731 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1732 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1733 			 "options when quota turned on");
1734 		return -1;
1735 	}
1736 
1737 	if (m->flags & MOPT_NOSUPPORT) {
1738 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1739 	} else if (token == Opt_commit) {
1740 		if (arg == 0)
1741 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1742 		sbi->s_commit_interval = HZ * arg;
1743 	} else if (token == Opt_debug_want_extra_isize) {
1744 		sbi->s_want_extra_isize = arg;
1745 	} else if (token == Opt_max_batch_time) {
1746 		sbi->s_max_batch_time = arg;
1747 	} else if (token == Opt_min_batch_time) {
1748 		sbi->s_min_batch_time = arg;
1749 	} else if (token == Opt_inode_readahead_blks) {
1750 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1751 			ext4_msg(sb, KERN_ERR,
1752 				 "EXT4-fs: inode_readahead_blks must be "
1753 				 "0 or a power of 2 smaller than 2^31");
1754 			return -1;
1755 		}
1756 		sbi->s_inode_readahead_blks = arg;
1757 	} else if (token == Opt_init_itable) {
1758 		set_opt(sb, INIT_INODE_TABLE);
1759 		if (!args->from)
1760 			arg = EXT4_DEF_LI_WAIT_MULT;
1761 		sbi->s_li_wait_mult = arg;
1762 	} else if (token == Opt_max_dir_size_kb) {
1763 		sbi->s_max_dir_size_kb = arg;
1764 	} else if (token == Opt_stripe) {
1765 		sbi->s_stripe = arg;
1766 	} else if (token == Opt_resuid) {
1767 		uid = make_kuid(current_user_ns(), arg);
1768 		if (!uid_valid(uid)) {
1769 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1770 			return -1;
1771 		}
1772 		sbi->s_resuid = uid;
1773 	} else if (token == Opt_resgid) {
1774 		gid = make_kgid(current_user_ns(), arg);
1775 		if (!gid_valid(gid)) {
1776 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1777 			return -1;
1778 		}
1779 		sbi->s_resgid = gid;
1780 	} else if (token == Opt_journal_dev) {
1781 		if (is_remount) {
1782 			ext4_msg(sb, KERN_ERR,
1783 				 "Cannot specify journal on remount");
1784 			return -1;
1785 		}
1786 		*journal_devnum = arg;
1787 	} else if (token == Opt_journal_path) {
1788 		char *journal_path;
1789 		struct inode *journal_inode;
1790 		struct path path;
1791 		int error;
1792 
1793 		if (is_remount) {
1794 			ext4_msg(sb, KERN_ERR,
1795 				 "Cannot specify journal on remount");
1796 			return -1;
1797 		}
1798 		journal_path = match_strdup(&args[0]);
1799 		if (!journal_path) {
1800 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1801 				"journal device string");
1802 			return -1;
1803 		}
1804 
1805 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1806 		if (error) {
1807 			ext4_msg(sb, KERN_ERR, "error: could not find "
1808 				"journal device path: error %d", error);
1809 			kfree(journal_path);
1810 			return -1;
1811 		}
1812 
1813 		journal_inode = d_inode(path.dentry);
1814 		if (!S_ISBLK(journal_inode->i_mode)) {
1815 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1816 				"is not a block device", journal_path);
1817 			path_put(&path);
1818 			kfree(journal_path);
1819 			return -1;
1820 		}
1821 
1822 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1823 		path_put(&path);
1824 		kfree(journal_path);
1825 	} else if (token == Opt_journal_ioprio) {
1826 		if (arg > 7) {
1827 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1828 				 " (must be 0-7)");
1829 			return -1;
1830 		}
1831 		*journal_ioprio =
1832 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1833 	} else if (token == Opt_test_dummy_encryption) {
1834 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1835 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1836 		ext4_msg(sb, KERN_WARNING,
1837 			 "Test dummy encryption mode enabled");
1838 #else
1839 		ext4_msg(sb, KERN_WARNING,
1840 			 "Test dummy encryption mount option ignored");
1841 #endif
1842 	} else if (m->flags & MOPT_DATAJ) {
1843 		if (is_remount) {
1844 			if (!sbi->s_journal)
1845 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1846 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1847 				ext4_msg(sb, KERN_ERR,
1848 					 "Cannot change data mode on remount");
1849 				return -1;
1850 			}
1851 		} else {
1852 			clear_opt(sb, DATA_FLAGS);
1853 			sbi->s_mount_opt |= m->mount_opt;
1854 		}
1855 #ifdef CONFIG_QUOTA
1856 	} else if (m->flags & MOPT_QFMT) {
1857 		if (sb_any_quota_loaded(sb) &&
1858 		    sbi->s_jquota_fmt != m->mount_opt) {
1859 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1860 				 "quota options when quota turned on");
1861 			return -1;
1862 		}
1863 		if (ext4_has_feature_quota(sb)) {
1864 			ext4_msg(sb, KERN_INFO,
1865 				 "Quota format mount options ignored "
1866 				 "when QUOTA feature is enabled");
1867 			return 1;
1868 		}
1869 		sbi->s_jquota_fmt = m->mount_opt;
1870 #endif
1871 	} else if (token == Opt_dax) {
1872 #ifdef CONFIG_FS_DAX
1873 		ext4_msg(sb, KERN_WARNING,
1874 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1875 			sbi->s_mount_opt |= m->mount_opt;
1876 #else
1877 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1878 		return -1;
1879 #endif
1880 	} else if (token == Opt_data_err_abort) {
1881 		sbi->s_mount_opt |= m->mount_opt;
1882 	} else if (token == Opt_data_err_ignore) {
1883 		sbi->s_mount_opt &= ~m->mount_opt;
1884 	} else {
1885 		if (!args->from)
1886 			arg = 1;
1887 		if (m->flags & MOPT_CLEAR)
1888 			arg = !arg;
1889 		else if (unlikely(!(m->flags & MOPT_SET))) {
1890 			ext4_msg(sb, KERN_WARNING,
1891 				 "buggy handling of option %s", opt);
1892 			WARN_ON(1);
1893 			return -1;
1894 		}
1895 		if (arg != 0)
1896 			sbi->s_mount_opt |= m->mount_opt;
1897 		else
1898 			sbi->s_mount_opt &= ~m->mount_opt;
1899 	}
1900 	return 1;
1901 }
1902 
1903 static int parse_options(char *options, struct super_block *sb,
1904 			 unsigned long *journal_devnum,
1905 			 unsigned int *journal_ioprio,
1906 			 int is_remount)
1907 {
1908 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1909 	char *p;
1910 	substring_t args[MAX_OPT_ARGS];
1911 	int token;
1912 
1913 	if (!options)
1914 		return 1;
1915 
1916 	while ((p = strsep(&options, ",")) != NULL) {
1917 		if (!*p)
1918 			continue;
1919 		/*
1920 		 * Initialize args struct so we know whether arg was
1921 		 * found; some options take optional arguments.
1922 		 */
1923 		args[0].to = args[0].from = NULL;
1924 		token = match_token(p, tokens, args);
1925 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1926 				     journal_ioprio, is_remount) < 0)
1927 			return 0;
1928 	}
1929 #ifdef CONFIG_QUOTA
1930 	/*
1931 	 * We do the test below only for project quotas. 'usrquota' and
1932 	 * 'grpquota' mount options are allowed even without quota feature
1933 	 * to support legacy quotas in quota files.
1934 	 */
1935 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1936 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1937 			 "Cannot enable project quota enforcement.");
1938 		return 0;
1939 	}
1940 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1941 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1942 			clear_opt(sb, USRQUOTA);
1943 
1944 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1945 			clear_opt(sb, GRPQUOTA);
1946 
1947 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1948 			ext4_msg(sb, KERN_ERR, "old and new quota "
1949 					"format mixing");
1950 			return 0;
1951 		}
1952 
1953 		if (!sbi->s_jquota_fmt) {
1954 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1955 					"not specified");
1956 			return 0;
1957 		}
1958 	}
1959 #endif
1960 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1961 		int blocksize =
1962 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1963 
1964 		if (blocksize < PAGE_SIZE) {
1965 			ext4_msg(sb, KERN_ERR, "can't mount with "
1966 				 "dioread_nolock if block size != PAGE_SIZE");
1967 			return 0;
1968 		}
1969 	}
1970 	return 1;
1971 }
1972 
1973 static inline void ext4_show_quota_options(struct seq_file *seq,
1974 					   struct super_block *sb)
1975 {
1976 #if defined(CONFIG_QUOTA)
1977 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1978 
1979 	if (sbi->s_jquota_fmt) {
1980 		char *fmtname = "";
1981 
1982 		switch (sbi->s_jquota_fmt) {
1983 		case QFMT_VFS_OLD:
1984 			fmtname = "vfsold";
1985 			break;
1986 		case QFMT_VFS_V0:
1987 			fmtname = "vfsv0";
1988 			break;
1989 		case QFMT_VFS_V1:
1990 			fmtname = "vfsv1";
1991 			break;
1992 		}
1993 		seq_printf(seq, ",jqfmt=%s", fmtname);
1994 	}
1995 
1996 	if (sbi->s_qf_names[USRQUOTA])
1997 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1998 
1999 	if (sbi->s_qf_names[GRPQUOTA])
2000 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
2001 #endif
2002 }
2003 
2004 static const char *token2str(int token)
2005 {
2006 	const struct match_token *t;
2007 
2008 	for (t = tokens; t->token != Opt_err; t++)
2009 		if (t->token == token && !strchr(t->pattern, '='))
2010 			break;
2011 	return t->pattern;
2012 }
2013 
2014 /*
2015  * Show an option if
2016  *  - it's set to a non-default value OR
2017  *  - if the per-sb default is different from the global default
2018  */
2019 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2020 			      int nodefs)
2021 {
2022 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2023 	struct ext4_super_block *es = sbi->s_es;
2024 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2025 	const struct mount_opts *m;
2026 	char sep = nodefs ? '\n' : ',';
2027 
2028 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2029 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2030 
2031 	if (sbi->s_sb_block != 1)
2032 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2033 
2034 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2035 		int want_set = m->flags & MOPT_SET;
2036 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2037 		    (m->flags & MOPT_CLEAR_ERR))
2038 			continue;
2039 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2040 			continue; /* skip if same as the default */
2041 		if ((want_set &&
2042 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2043 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2044 			continue; /* select Opt_noFoo vs Opt_Foo */
2045 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2046 	}
2047 
2048 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2049 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2050 		SEQ_OPTS_PRINT("resuid=%u",
2051 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2052 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2053 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2054 		SEQ_OPTS_PRINT("resgid=%u",
2055 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2056 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2057 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2058 		SEQ_OPTS_PUTS("errors=remount-ro");
2059 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2060 		SEQ_OPTS_PUTS("errors=continue");
2061 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2062 		SEQ_OPTS_PUTS("errors=panic");
2063 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2064 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2065 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2066 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2067 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2068 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2069 	if (sb->s_flags & SB_I_VERSION)
2070 		SEQ_OPTS_PUTS("i_version");
2071 	if (nodefs || sbi->s_stripe)
2072 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2073 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2074 			(sbi->s_mount_opt ^ def_mount_opt)) {
2075 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2076 			SEQ_OPTS_PUTS("data=journal");
2077 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2078 			SEQ_OPTS_PUTS("data=ordered");
2079 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2080 			SEQ_OPTS_PUTS("data=writeback");
2081 	}
2082 	if (nodefs ||
2083 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2084 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2085 			       sbi->s_inode_readahead_blks);
2086 
2087 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2088 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2089 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2090 	if (nodefs || sbi->s_max_dir_size_kb)
2091 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2092 	if (test_opt(sb, DATA_ERR_ABORT))
2093 		SEQ_OPTS_PUTS("data_err=abort");
2094 
2095 	ext4_show_quota_options(seq, sb);
2096 	return 0;
2097 }
2098 
2099 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2100 {
2101 	return _ext4_show_options(seq, root->d_sb, 0);
2102 }
2103 
2104 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2105 {
2106 	struct super_block *sb = seq->private;
2107 	int rc;
2108 
2109 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2110 	rc = _ext4_show_options(seq, sb, 1);
2111 	seq_puts(seq, "\n");
2112 	return rc;
2113 }
2114 
2115 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2116 			    int read_only)
2117 {
2118 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2119 	int res = 0;
2120 
2121 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2122 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2123 			 "forcing read-only mode");
2124 		res = SB_RDONLY;
2125 	}
2126 	if (read_only)
2127 		goto done;
2128 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2129 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2130 			 "running e2fsck is recommended");
2131 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2132 		ext4_msg(sb, KERN_WARNING,
2133 			 "warning: mounting fs with errors, "
2134 			 "running e2fsck is recommended");
2135 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2136 		 le16_to_cpu(es->s_mnt_count) >=
2137 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2138 		ext4_msg(sb, KERN_WARNING,
2139 			 "warning: maximal mount count reached, "
2140 			 "running e2fsck is recommended");
2141 	else if (le32_to_cpu(es->s_checkinterval) &&
2142 		(le32_to_cpu(es->s_lastcheck) +
2143 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2144 		ext4_msg(sb, KERN_WARNING,
2145 			 "warning: checktime reached, "
2146 			 "running e2fsck is recommended");
2147 	if (!sbi->s_journal)
2148 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2149 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2150 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2151 	le16_add_cpu(&es->s_mnt_count, 1);
2152 	es->s_mtime = cpu_to_le32(get_seconds());
2153 	ext4_update_dynamic_rev(sb);
2154 	if (sbi->s_journal)
2155 		ext4_set_feature_journal_needs_recovery(sb);
2156 
2157 	ext4_commit_super(sb, 1);
2158 done:
2159 	if (test_opt(sb, DEBUG))
2160 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2161 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2162 			sb->s_blocksize,
2163 			sbi->s_groups_count,
2164 			EXT4_BLOCKS_PER_GROUP(sb),
2165 			EXT4_INODES_PER_GROUP(sb),
2166 			sbi->s_mount_opt, sbi->s_mount_opt2);
2167 
2168 	cleancache_init_fs(sb);
2169 	return res;
2170 }
2171 
2172 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2173 {
2174 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2175 	struct flex_groups *new_groups;
2176 	int size;
2177 
2178 	if (!sbi->s_log_groups_per_flex)
2179 		return 0;
2180 
2181 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2182 	if (size <= sbi->s_flex_groups_allocated)
2183 		return 0;
2184 
2185 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2186 	new_groups = kvzalloc(size, GFP_KERNEL);
2187 	if (!new_groups) {
2188 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2189 			 size / (int) sizeof(struct flex_groups));
2190 		return -ENOMEM;
2191 	}
2192 
2193 	if (sbi->s_flex_groups) {
2194 		memcpy(new_groups, sbi->s_flex_groups,
2195 		       (sbi->s_flex_groups_allocated *
2196 			sizeof(struct flex_groups)));
2197 		kvfree(sbi->s_flex_groups);
2198 	}
2199 	sbi->s_flex_groups = new_groups;
2200 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2201 	return 0;
2202 }
2203 
2204 static int ext4_fill_flex_info(struct super_block *sb)
2205 {
2206 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2207 	struct ext4_group_desc *gdp = NULL;
2208 	ext4_group_t flex_group;
2209 	int i, err;
2210 
2211 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2212 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2213 		sbi->s_log_groups_per_flex = 0;
2214 		return 1;
2215 	}
2216 
2217 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2218 	if (err)
2219 		goto failed;
2220 
2221 	for (i = 0; i < sbi->s_groups_count; i++) {
2222 		gdp = ext4_get_group_desc(sb, i, NULL);
2223 
2224 		flex_group = ext4_flex_group(sbi, i);
2225 		atomic_add(ext4_free_inodes_count(sb, gdp),
2226 			   &sbi->s_flex_groups[flex_group].free_inodes);
2227 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2228 			     &sbi->s_flex_groups[flex_group].free_clusters);
2229 		atomic_add(ext4_used_dirs_count(sb, gdp),
2230 			   &sbi->s_flex_groups[flex_group].used_dirs);
2231 	}
2232 
2233 	return 1;
2234 failed:
2235 	return 0;
2236 }
2237 
2238 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2239 				   struct ext4_group_desc *gdp)
2240 {
2241 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2242 	__u16 crc = 0;
2243 	__le32 le_group = cpu_to_le32(block_group);
2244 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2245 
2246 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2247 		/* Use new metadata_csum algorithm */
2248 		__u32 csum32;
2249 		__u16 dummy_csum = 0;
2250 
2251 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2252 				     sizeof(le_group));
2253 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2254 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2255 				     sizeof(dummy_csum));
2256 		offset += sizeof(dummy_csum);
2257 		if (offset < sbi->s_desc_size)
2258 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2259 					     sbi->s_desc_size - offset);
2260 
2261 		crc = csum32 & 0xFFFF;
2262 		goto out;
2263 	}
2264 
2265 	/* old crc16 code */
2266 	if (!ext4_has_feature_gdt_csum(sb))
2267 		return 0;
2268 
2269 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2270 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2271 	crc = crc16(crc, (__u8 *)gdp, offset);
2272 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2273 	/* for checksum of struct ext4_group_desc do the rest...*/
2274 	if (ext4_has_feature_64bit(sb) &&
2275 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2276 		crc = crc16(crc, (__u8 *)gdp + offset,
2277 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2278 				offset);
2279 
2280 out:
2281 	return cpu_to_le16(crc);
2282 }
2283 
2284 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2285 				struct ext4_group_desc *gdp)
2286 {
2287 	if (ext4_has_group_desc_csum(sb) &&
2288 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2289 		return 0;
2290 
2291 	return 1;
2292 }
2293 
2294 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2295 			      struct ext4_group_desc *gdp)
2296 {
2297 	if (!ext4_has_group_desc_csum(sb))
2298 		return;
2299 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2300 }
2301 
2302 /* Called at mount-time, super-block is locked */
2303 static int ext4_check_descriptors(struct super_block *sb,
2304 				  ext4_fsblk_t sb_block,
2305 				  ext4_group_t *first_not_zeroed)
2306 {
2307 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2308 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2309 	ext4_fsblk_t last_block;
2310 	ext4_fsblk_t block_bitmap;
2311 	ext4_fsblk_t inode_bitmap;
2312 	ext4_fsblk_t inode_table;
2313 	int flexbg_flag = 0;
2314 	ext4_group_t i, grp = sbi->s_groups_count;
2315 
2316 	if (ext4_has_feature_flex_bg(sb))
2317 		flexbg_flag = 1;
2318 
2319 	ext4_debug("Checking group descriptors");
2320 
2321 	for (i = 0; i < sbi->s_groups_count; i++) {
2322 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2323 
2324 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2325 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2326 		else
2327 			last_block = first_block +
2328 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2329 
2330 		if ((grp == sbi->s_groups_count) &&
2331 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2332 			grp = i;
2333 
2334 		block_bitmap = ext4_block_bitmap(sb, gdp);
2335 		if (block_bitmap == sb_block) {
2336 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2337 				 "Block bitmap for group %u overlaps "
2338 				 "superblock", i);
2339 			if (!sb_rdonly(sb))
2340 				return 0;
2341 		}
2342 		if (block_bitmap < first_block || block_bitmap > last_block) {
2343 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2344 			       "Block bitmap for group %u not in group "
2345 			       "(block %llu)!", i, block_bitmap);
2346 			return 0;
2347 		}
2348 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2349 		if (inode_bitmap == sb_block) {
2350 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2351 				 "Inode bitmap for group %u overlaps "
2352 				 "superblock", i);
2353 			if (!sb_rdonly(sb))
2354 				return 0;
2355 		}
2356 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2357 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2358 			       "Inode bitmap for group %u not in group "
2359 			       "(block %llu)!", i, inode_bitmap);
2360 			return 0;
2361 		}
2362 		inode_table = ext4_inode_table(sb, gdp);
2363 		if (inode_table == sb_block) {
2364 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2365 				 "Inode table for group %u overlaps "
2366 				 "superblock", i);
2367 			if (!sb_rdonly(sb))
2368 				return 0;
2369 		}
2370 		if (inode_table < first_block ||
2371 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2372 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2373 			       "Inode table for group %u not in group "
2374 			       "(block %llu)!", i, inode_table);
2375 			return 0;
2376 		}
2377 		ext4_lock_group(sb, i);
2378 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2379 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2380 				 "Checksum for group %u failed (%u!=%u)",
2381 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2382 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2383 			if (!sb_rdonly(sb)) {
2384 				ext4_unlock_group(sb, i);
2385 				return 0;
2386 			}
2387 		}
2388 		ext4_unlock_group(sb, i);
2389 		if (!flexbg_flag)
2390 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2391 	}
2392 	if (NULL != first_not_zeroed)
2393 		*first_not_zeroed = grp;
2394 	return 1;
2395 }
2396 
2397 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2398  * the superblock) which were deleted from all directories, but held open by
2399  * a process at the time of a crash.  We walk the list and try to delete these
2400  * inodes at recovery time (only with a read-write filesystem).
2401  *
2402  * In order to keep the orphan inode chain consistent during traversal (in
2403  * case of crash during recovery), we link each inode into the superblock
2404  * orphan list_head and handle it the same way as an inode deletion during
2405  * normal operation (which journals the operations for us).
2406  *
2407  * We only do an iget() and an iput() on each inode, which is very safe if we
2408  * accidentally point at an in-use or already deleted inode.  The worst that
2409  * can happen in this case is that we get a "bit already cleared" message from
2410  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2411  * e2fsck was run on this filesystem, and it must have already done the orphan
2412  * inode cleanup for us, so we can safely abort without any further action.
2413  */
2414 static void ext4_orphan_cleanup(struct super_block *sb,
2415 				struct ext4_super_block *es)
2416 {
2417 	unsigned int s_flags = sb->s_flags;
2418 	int ret, nr_orphans = 0, nr_truncates = 0;
2419 #ifdef CONFIG_QUOTA
2420 	int quota_update = 0;
2421 	int i;
2422 #endif
2423 	if (!es->s_last_orphan) {
2424 		jbd_debug(4, "no orphan inodes to clean up\n");
2425 		return;
2426 	}
2427 
2428 	if (bdev_read_only(sb->s_bdev)) {
2429 		ext4_msg(sb, KERN_ERR, "write access "
2430 			"unavailable, skipping orphan cleanup");
2431 		return;
2432 	}
2433 
2434 	/* Check if feature set would not allow a r/w mount */
2435 	if (!ext4_feature_set_ok(sb, 0)) {
2436 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2437 			 "unknown ROCOMPAT features");
2438 		return;
2439 	}
2440 
2441 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2442 		/* don't clear list on RO mount w/ errors */
2443 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2444 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2445 				  "clearing orphan list.\n");
2446 			es->s_last_orphan = 0;
2447 		}
2448 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2449 		return;
2450 	}
2451 
2452 	if (s_flags & SB_RDONLY) {
2453 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2454 		sb->s_flags &= ~SB_RDONLY;
2455 	}
2456 #ifdef CONFIG_QUOTA
2457 	/* Needed for iput() to work correctly and not trash data */
2458 	sb->s_flags |= SB_ACTIVE;
2459 
2460 	/*
2461 	 * Turn on quotas which were not enabled for read-only mounts if
2462 	 * filesystem has quota feature, so that they are updated correctly.
2463 	 */
2464 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2465 		int ret = ext4_enable_quotas(sb);
2466 
2467 		if (!ret)
2468 			quota_update = 1;
2469 		else
2470 			ext4_msg(sb, KERN_ERR,
2471 				"Cannot turn on quotas: error %d", ret);
2472 	}
2473 
2474 	/* Turn on journaled quotas used for old sytle */
2475 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2476 		if (EXT4_SB(sb)->s_qf_names[i]) {
2477 			int ret = ext4_quota_on_mount(sb, i);
2478 
2479 			if (!ret)
2480 				quota_update = 1;
2481 			else
2482 				ext4_msg(sb, KERN_ERR,
2483 					"Cannot turn on journaled "
2484 					"quota: type %d: error %d", i, ret);
2485 		}
2486 	}
2487 #endif
2488 
2489 	while (es->s_last_orphan) {
2490 		struct inode *inode;
2491 
2492 		/*
2493 		 * We may have encountered an error during cleanup; if
2494 		 * so, skip the rest.
2495 		 */
2496 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2497 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2498 			es->s_last_orphan = 0;
2499 			break;
2500 		}
2501 
2502 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2503 		if (IS_ERR(inode)) {
2504 			es->s_last_orphan = 0;
2505 			break;
2506 		}
2507 
2508 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2509 		dquot_initialize(inode);
2510 		if (inode->i_nlink) {
2511 			if (test_opt(sb, DEBUG))
2512 				ext4_msg(sb, KERN_DEBUG,
2513 					"%s: truncating inode %lu to %lld bytes",
2514 					__func__, inode->i_ino, inode->i_size);
2515 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2516 				  inode->i_ino, inode->i_size);
2517 			inode_lock(inode);
2518 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2519 			ret = ext4_truncate(inode);
2520 			if (ret)
2521 				ext4_std_error(inode->i_sb, ret);
2522 			inode_unlock(inode);
2523 			nr_truncates++;
2524 		} else {
2525 			if (test_opt(sb, DEBUG))
2526 				ext4_msg(sb, KERN_DEBUG,
2527 					"%s: deleting unreferenced inode %lu",
2528 					__func__, inode->i_ino);
2529 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2530 				  inode->i_ino);
2531 			nr_orphans++;
2532 		}
2533 		iput(inode);  /* The delete magic happens here! */
2534 	}
2535 
2536 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2537 
2538 	if (nr_orphans)
2539 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2540 		       PLURAL(nr_orphans));
2541 	if (nr_truncates)
2542 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2543 		       PLURAL(nr_truncates));
2544 #ifdef CONFIG_QUOTA
2545 	/* Turn off quotas if they were enabled for orphan cleanup */
2546 	if (quota_update) {
2547 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2548 			if (sb_dqopt(sb)->files[i])
2549 				dquot_quota_off(sb, i);
2550 		}
2551 	}
2552 #endif
2553 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2554 }
2555 
2556 /*
2557  * Maximal extent format file size.
2558  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2559  * extent format containers, within a sector_t, and within i_blocks
2560  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2561  * so that won't be a limiting factor.
2562  *
2563  * However there is other limiting factor. We do store extents in the form
2564  * of starting block and length, hence the resulting length of the extent
2565  * covering maximum file size must fit into on-disk format containers as
2566  * well. Given that length is always by 1 unit bigger than max unit (because
2567  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2568  *
2569  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2570  */
2571 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2572 {
2573 	loff_t res;
2574 	loff_t upper_limit = MAX_LFS_FILESIZE;
2575 
2576 	/* small i_blocks in vfs inode? */
2577 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2578 		/*
2579 		 * CONFIG_LBDAF is not enabled implies the inode
2580 		 * i_block represent total blocks in 512 bytes
2581 		 * 32 == size of vfs inode i_blocks * 8
2582 		 */
2583 		upper_limit = (1LL << 32) - 1;
2584 
2585 		/* total blocks in file system block size */
2586 		upper_limit >>= (blkbits - 9);
2587 		upper_limit <<= blkbits;
2588 	}
2589 
2590 	/*
2591 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2592 	 * by one fs block, so ee_len can cover the extent of maximum file
2593 	 * size
2594 	 */
2595 	res = (1LL << 32) - 1;
2596 	res <<= blkbits;
2597 
2598 	/* Sanity check against vm- & vfs- imposed limits */
2599 	if (res > upper_limit)
2600 		res = upper_limit;
2601 
2602 	return res;
2603 }
2604 
2605 /*
2606  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2607  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2608  * We need to be 1 filesystem block less than the 2^48 sector limit.
2609  */
2610 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2611 {
2612 	loff_t res = EXT4_NDIR_BLOCKS;
2613 	int meta_blocks;
2614 	loff_t upper_limit;
2615 	/* This is calculated to be the largest file size for a dense, block
2616 	 * mapped file such that the file's total number of 512-byte sectors,
2617 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2618 	 *
2619 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2620 	 * number of 512-byte sectors of the file.
2621 	 */
2622 
2623 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2624 		/*
2625 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2626 		 * the inode i_block field represents total file blocks in
2627 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2628 		 */
2629 		upper_limit = (1LL << 32) - 1;
2630 
2631 		/* total blocks in file system block size */
2632 		upper_limit >>= (bits - 9);
2633 
2634 	} else {
2635 		/*
2636 		 * We use 48 bit ext4_inode i_blocks
2637 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2638 		 * represent total number of blocks in
2639 		 * file system block size
2640 		 */
2641 		upper_limit = (1LL << 48) - 1;
2642 
2643 	}
2644 
2645 	/* indirect blocks */
2646 	meta_blocks = 1;
2647 	/* double indirect blocks */
2648 	meta_blocks += 1 + (1LL << (bits-2));
2649 	/* tripple indirect blocks */
2650 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2651 
2652 	upper_limit -= meta_blocks;
2653 	upper_limit <<= bits;
2654 
2655 	res += 1LL << (bits-2);
2656 	res += 1LL << (2*(bits-2));
2657 	res += 1LL << (3*(bits-2));
2658 	res <<= bits;
2659 	if (res > upper_limit)
2660 		res = upper_limit;
2661 
2662 	if (res > MAX_LFS_FILESIZE)
2663 		res = MAX_LFS_FILESIZE;
2664 
2665 	return res;
2666 }
2667 
2668 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2669 				   ext4_fsblk_t logical_sb_block, int nr)
2670 {
2671 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2672 	ext4_group_t bg, first_meta_bg;
2673 	int has_super = 0;
2674 
2675 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2676 
2677 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2678 		return logical_sb_block + nr + 1;
2679 	bg = sbi->s_desc_per_block * nr;
2680 	if (ext4_bg_has_super(sb, bg))
2681 		has_super = 1;
2682 
2683 	/*
2684 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2685 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2686 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2687 	 * compensate.
2688 	 */
2689 	if (sb->s_blocksize == 1024 && nr == 0 &&
2690 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2691 		has_super++;
2692 
2693 	return (has_super + ext4_group_first_block_no(sb, bg));
2694 }
2695 
2696 /**
2697  * ext4_get_stripe_size: Get the stripe size.
2698  * @sbi: In memory super block info
2699  *
2700  * If we have specified it via mount option, then
2701  * use the mount option value. If the value specified at mount time is
2702  * greater than the blocks per group use the super block value.
2703  * If the super block value is greater than blocks per group return 0.
2704  * Allocator needs it be less than blocks per group.
2705  *
2706  */
2707 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2708 {
2709 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2710 	unsigned long stripe_width =
2711 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2712 	int ret;
2713 
2714 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2715 		ret = sbi->s_stripe;
2716 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2717 		ret = stripe_width;
2718 	else if (stride && stride <= sbi->s_blocks_per_group)
2719 		ret = stride;
2720 	else
2721 		ret = 0;
2722 
2723 	/*
2724 	 * If the stripe width is 1, this makes no sense and
2725 	 * we set it to 0 to turn off stripe handling code.
2726 	 */
2727 	if (ret <= 1)
2728 		ret = 0;
2729 
2730 	return ret;
2731 }
2732 
2733 /*
2734  * Check whether this filesystem can be mounted based on
2735  * the features present and the RDONLY/RDWR mount requested.
2736  * Returns 1 if this filesystem can be mounted as requested,
2737  * 0 if it cannot be.
2738  */
2739 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2740 {
2741 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2742 		ext4_msg(sb, KERN_ERR,
2743 			"Couldn't mount because of "
2744 			"unsupported optional features (%x)",
2745 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2746 			~EXT4_FEATURE_INCOMPAT_SUPP));
2747 		return 0;
2748 	}
2749 
2750 	if (readonly)
2751 		return 1;
2752 
2753 	if (ext4_has_feature_readonly(sb)) {
2754 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2755 		sb->s_flags |= SB_RDONLY;
2756 		return 1;
2757 	}
2758 
2759 	/* Check that feature set is OK for a read-write mount */
2760 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2761 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2762 			 "unsupported optional features (%x)",
2763 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2764 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2765 		return 0;
2766 	}
2767 	/*
2768 	 * Large file size enabled file system can only be mounted
2769 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2770 	 */
2771 	if (ext4_has_feature_huge_file(sb)) {
2772 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2773 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2774 				 "cannot be mounted RDWR without "
2775 				 "CONFIG_LBDAF");
2776 			return 0;
2777 		}
2778 	}
2779 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2780 		ext4_msg(sb, KERN_ERR,
2781 			 "Can't support bigalloc feature without "
2782 			 "extents feature\n");
2783 		return 0;
2784 	}
2785 
2786 #ifndef CONFIG_QUOTA
2787 	if (ext4_has_feature_quota(sb) && !readonly) {
2788 		ext4_msg(sb, KERN_ERR,
2789 			 "Filesystem with quota feature cannot be mounted RDWR "
2790 			 "without CONFIG_QUOTA");
2791 		return 0;
2792 	}
2793 	if (ext4_has_feature_project(sb) && !readonly) {
2794 		ext4_msg(sb, KERN_ERR,
2795 			 "Filesystem with project quota feature cannot be mounted RDWR "
2796 			 "without CONFIG_QUOTA");
2797 		return 0;
2798 	}
2799 #endif  /* CONFIG_QUOTA */
2800 	return 1;
2801 }
2802 
2803 /*
2804  * This function is called once a day if we have errors logged
2805  * on the file system
2806  */
2807 static void print_daily_error_info(struct timer_list *t)
2808 {
2809 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2810 	struct super_block *sb = sbi->s_sb;
2811 	struct ext4_super_block *es = sbi->s_es;
2812 
2813 	if (es->s_error_count)
2814 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2815 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2816 			 le32_to_cpu(es->s_error_count));
2817 	if (es->s_first_error_time) {
2818 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2819 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2820 		       (int) sizeof(es->s_first_error_func),
2821 		       es->s_first_error_func,
2822 		       le32_to_cpu(es->s_first_error_line));
2823 		if (es->s_first_error_ino)
2824 			printk(KERN_CONT ": inode %u",
2825 			       le32_to_cpu(es->s_first_error_ino));
2826 		if (es->s_first_error_block)
2827 			printk(KERN_CONT ": block %llu", (unsigned long long)
2828 			       le64_to_cpu(es->s_first_error_block));
2829 		printk(KERN_CONT "\n");
2830 	}
2831 	if (es->s_last_error_time) {
2832 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2833 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2834 		       (int) sizeof(es->s_last_error_func),
2835 		       es->s_last_error_func,
2836 		       le32_to_cpu(es->s_last_error_line));
2837 		if (es->s_last_error_ino)
2838 			printk(KERN_CONT ": inode %u",
2839 			       le32_to_cpu(es->s_last_error_ino));
2840 		if (es->s_last_error_block)
2841 			printk(KERN_CONT ": block %llu", (unsigned long long)
2842 			       le64_to_cpu(es->s_last_error_block));
2843 		printk(KERN_CONT "\n");
2844 	}
2845 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2846 }
2847 
2848 /* Find next suitable group and run ext4_init_inode_table */
2849 static int ext4_run_li_request(struct ext4_li_request *elr)
2850 {
2851 	struct ext4_group_desc *gdp = NULL;
2852 	ext4_group_t group, ngroups;
2853 	struct super_block *sb;
2854 	unsigned long timeout = 0;
2855 	int ret = 0;
2856 
2857 	sb = elr->lr_super;
2858 	ngroups = EXT4_SB(sb)->s_groups_count;
2859 
2860 	for (group = elr->lr_next_group; group < ngroups; group++) {
2861 		gdp = ext4_get_group_desc(sb, group, NULL);
2862 		if (!gdp) {
2863 			ret = 1;
2864 			break;
2865 		}
2866 
2867 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2868 			break;
2869 	}
2870 
2871 	if (group >= ngroups)
2872 		ret = 1;
2873 
2874 	if (!ret) {
2875 		timeout = jiffies;
2876 		ret = ext4_init_inode_table(sb, group,
2877 					    elr->lr_timeout ? 0 : 1);
2878 		if (elr->lr_timeout == 0) {
2879 			timeout = (jiffies - timeout) *
2880 				  elr->lr_sbi->s_li_wait_mult;
2881 			elr->lr_timeout = timeout;
2882 		}
2883 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2884 		elr->lr_next_group = group + 1;
2885 	}
2886 	return ret;
2887 }
2888 
2889 /*
2890  * Remove lr_request from the list_request and free the
2891  * request structure. Should be called with li_list_mtx held
2892  */
2893 static void ext4_remove_li_request(struct ext4_li_request *elr)
2894 {
2895 	struct ext4_sb_info *sbi;
2896 
2897 	if (!elr)
2898 		return;
2899 
2900 	sbi = elr->lr_sbi;
2901 
2902 	list_del(&elr->lr_request);
2903 	sbi->s_li_request = NULL;
2904 	kfree(elr);
2905 }
2906 
2907 static void ext4_unregister_li_request(struct super_block *sb)
2908 {
2909 	mutex_lock(&ext4_li_mtx);
2910 	if (!ext4_li_info) {
2911 		mutex_unlock(&ext4_li_mtx);
2912 		return;
2913 	}
2914 
2915 	mutex_lock(&ext4_li_info->li_list_mtx);
2916 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2917 	mutex_unlock(&ext4_li_info->li_list_mtx);
2918 	mutex_unlock(&ext4_li_mtx);
2919 }
2920 
2921 static struct task_struct *ext4_lazyinit_task;
2922 
2923 /*
2924  * This is the function where ext4lazyinit thread lives. It walks
2925  * through the request list searching for next scheduled filesystem.
2926  * When such a fs is found, run the lazy initialization request
2927  * (ext4_rn_li_request) and keep track of the time spend in this
2928  * function. Based on that time we compute next schedule time of
2929  * the request. When walking through the list is complete, compute
2930  * next waking time and put itself into sleep.
2931  */
2932 static int ext4_lazyinit_thread(void *arg)
2933 {
2934 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2935 	struct list_head *pos, *n;
2936 	struct ext4_li_request *elr;
2937 	unsigned long next_wakeup, cur;
2938 
2939 	BUG_ON(NULL == eli);
2940 
2941 cont_thread:
2942 	while (true) {
2943 		next_wakeup = MAX_JIFFY_OFFSET;
2944 
2945 		mutex_lock(&eli->li_list_mtx);
2946 		if (list_empty(&eli->li_request_list)) {
2947 			mutex_unlock(&eli->li_list_mtx);
2948 			goto exit_thread;
2949 		}
2950 		list_for_each_safe(pos, n, &eli->li_request_list) {
2951 			int err = 0;
2952 			int progress = 0;
2953 			elr = list_entry(pos, struct ext4_li_request,
2954 					 lr_request);
2955 
2956 			if (time_before(jiffies, elr->lr_next_sched)) {
2957 				if (time_before(elr->lr_next_sched, next_wakeup))
2958 					next_wakeup = elr->lr_next_sched;
2959 				continue;
2960 			}
2961 			if (down_read_trylock(&elr->lr_super->s_umount)) {
2962 				if (sb_start_write_trylock(elr->lr_super)) {
2963 					progress = 1;
2964 					/*
2965 					 * We hold sb->s_umount, sb can not
2966 					 * be removed from the list, it is
2967 					 * now safe to drop li_list_mtx
2968 					 */
2969 					mutex_unlock(&eli->li_list_mtx);
2970 					err = ext4_run_li_request(elr);
2971 					sb_end_write(elr->lr_super);
2972 					mutex_lock(&eli->li_list_mtx);
2973 					n = pos->next;
2974 				}
2975 				up_read((&elr->lr_super->s_umount));
2976 			}
2977 			/* error, remove the lazy_init job */
2978 			if (err) {
2979 				ext4_remove_li_request(elr);
2980 				continue;
2981 			}
2982 			if (!progress) {
2983 				elr->lr_next_sched = jiffies +
2984 					(prandom_u32()
2985 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2986 			}
2987 			if (time_before(elr->lr_next_sched, next_wakeup))
2988 				next_wakeup = elr->lr_next_sched;
2989 		}
2990 		mutex_unlock(&eli->li_list_mtx);
2991 
2992 		try_to_freeze();
2993 
2994 		cur = jiffies;
2995 		if ((time_after_eq(cur, next_wakeup)) ||
2996 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2997 			cond_resched();
2998 			continue;
2999 		}
3000 
3001 		schedule_timeout_interruptible(next_wakeup - cur);
3002 
3003 		if (kthread_should_stop()) {
3004 			ext4_clear_request_list();
3005 			goto exit_thread;
3006 		}
3007 	}
3008 
3009 exit_thread:
3010 	/*
3011 	 * It looks like the request list is empty, but we need
3012 	 * to check it under the li_list_mtx lock, to prevent any
3013 	 * additions into it, and of course we should lock ext4_li_mtx
3014 	 * to atomically free the list and ext4_li_info, because at
3015 	 * this point another ext4 filesystem could be registering
3016 	 * new one.
3017 	 */
3018 	mutex_lock(&ext4_li_mtx);
3019 	mutex_lock(&eli->li_list_mtx);
3020 	if (!list_empty(&eli->li_request_list)) {
3021 		mutex_unlock(&eli->li_list_mtx);
3022 		mutex_unlock(&ext4_li_mtx);
3023 		goto cont_thread;
3024 	}
3025 	mutex_unlock(&eli->li_list_mtx);
3026 	kfree(ext4_li_info);
3027 	ext4_li_info = NULL;
3028 	mutex_unlock(&ext4_li_mtx);
3029 
3030 	return 0;
3031 }
3032 
3033 static void ext4_clear_request_list(void)
3034 {
3035 	struct list_head *pos, *n;
3036 	struct ext4_li_request *elr;
3037 
3038 	mutex_lock(&ext4_li_info->li_list_mtx);
3039 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3040 		elr = list_entry(pos, struct ext4_li_request,
3041 				 lr_request);
3042 		ext4_remove_li_request(elr);
3043 	}
3044 	mutex_unlock(&ext4_li_info->li_list_mtx);
3045 }
3046 
3047 static int ext4_run_lazyinit_thread(void)
3048 {
3049 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3050 					 ext4_li_info, "ext4lazyinit");
3051 	if (IS_ERR(ext4_lazyinit_task)) {
3052 		int err = PTR_ERR(ext4_lazyinit_task);
3053 		ext4_clear_request_list();
3054 		kfree(ext4_li_info);
3055 		ext4_li_info = NULL;
3056 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3057 				 "initialization thread\n",
3058 				 err);
3059 		return err;
3060 	}
3061 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3062 	return 0;
3063 }
3064 
3065 /*
3066  * Check whether it make sense to run itable init. thread or not.
3067  * If there is at least one uninitialized inode table, return
3068  * corresponding group number, else the loop goes through all
3069  * groups and return total number of groups.
3070  */
3071 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3072 {
3073 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3074 	struct ext4_group_desc *gdp = NULL;
3075 
3076 	for (group = 0; group < ngroups; group++) {
3077 		gdp = ext4_get_group_desc(sb, group, NULL);
3078 		if (!gdp)
3079 			continue;
3080 
3081 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3082 			break;
3083 	}
3084 
3085 	return group;
3086 }
3087 
3088 static int ext4_li_info_new(void)
3089 {
3090 	struct ext4_lazy_init *eli = NULL;
3091 
3092 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3093 	if (!eli)
3094 		return -ENOMEM;
3095 
3096 	INIT_LIST_HEAD(&eli->li_request_list);
3097 	mutex_init(&eli->li_list_mtx);
3098 
3099 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3100 
3101 	ext4_li_info = eli;
3102 
3103 	return 0;
3104 }
3105 
3106 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3107 					    ext4_group_t start)
3108 {
3109 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3110 	struct ext4_li_request *elr;
3111 
3112 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3113 	if (!elr)
3114 		return NULL;
3115 
3116 	elr->lr_super = sb;
3117 	elr->lr_sbi = sbi;
3118 	elr->lr_next_group = start;
3119 
3120 	/*
3121 	 * Randomize first schedule time of the request to
3122 	 * spread the inode table initialization requests
3123 	 * better.
3124 	 */
3125 	elr->lr_next_sched = jiffies + (prandom_u32() %
3126 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3127 	return elr;
3128 }
3129 
3130 int ext4_register_li_request(struct super_block *sb,
3131 			     ext4_group_t first_not_zeroed)
3132 {
3133 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3134 	struct ext4_li_request *elr = NULL;
3135 	ext4_group_t ngroups = sbi->s_groups_count;
3136 	int ret = 0;
3137 
3138 	mutex_lock(&ext4_li_mtx);
3139 	if (sbi->s_li_request != NULL) {
3140 		/*
3141 		 * Reset timeout so it can be computed again, because
3142 		 * s_li_wait_mult might have changed.
3143 		 */
3144 		sbi->s_li_request->lr_timeout = 0;
3145 		goto out;
3146 	}
3147 
3148 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3149 	    !test_opt(sb, INIT_INODE_TABLE))
3150 		goto out;
3151 
3152 	elr = ext4_li_request_new(sb, first_not_zeroed);
3153 	if (!elr) {
3154 		ret = -ENOMEM;
3155 		goto out;
3156 	}
3157 
3158 	if (NULL == ext4_li_info) {
3159 		ret = ext4_li_info_new();
3160 		if (ret)
3161 			goto out;
3162 	}
3163 
3164 	mutex_lock(&ext4_li_info->li_list_mtx);
3165 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3166 	mutex_unlock(&ext4_li_info->li_list_mtx);
3167 
3168 	sbi->s_li_request = elr;
3169 	/*
3170 	 * set elr to NULL here since it has been inserted to
3171 	 * the request_list and the removal and free of it is
3172 	 * handled by ext4_clear_request_list from now on.
3173 	 */
3174 	elr = NULL;
3175 
3176 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3177 		ret = ext4_run_lazyinit_thread();
3178 		if (ret)
3179 			goto out;
3180 	}
3181 out:
3182 	mutex_unlock(&ext4_li_mtx);
3183 	if (ret)
3184 		kfree(elr);
3185 	return ret;
3186 }
3187 
3188 /*
3189  * We do not need to lock anything since this is called on
3190  * module unload.
3191  */
3192 static void ext4_destroy_lazyinit_thread(void)
3193 {
3194 	/*
3195 	 * If thread exited earlier
3196 	 * there's nothing to be done.
3197 	 */
3198 	if (!ext4_li_info || !ext4_lazyinit_task)
3199 		return;
3200 
3201 	kthread_stop(ext4_lazyinit_task);
3202 }
3203 
3204 static int set_journal_csum_feature_set(struct super_block *sb)
3205 {
3206 	int ret = 1;
3207 	int compat, incompat;
3208 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3209 
3210 	if (ext4_has_metadata_csum(sb)) {
3211 		/* journal checksum v3 */
3212 		compat = 0;
3213 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3214 	} else {
3215 		/* journal checksum v1 */
3216 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3217 		incompat = 0;
3218 	}
3219 
3220 	jbd2_journal_clear_features(sbi->s_journal,
3221 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3222 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3223 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3224 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3225 		ret = jbd2_journal_set_features(sbi->s_journal,
3226 				compat, 0,
3227 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3228 				incompat);
3229 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3230 		ret = jbd2_journal_set_features(sbi->s_journal,
3231 				compat, 0,
3232 				incompat);
3233 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3234 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3235 	} else {
3236 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3237 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3238 	}
3239 
3240 	return ret;
3241 }
3242 
3243 /*
3244  * Note: calculating the overhead so we can be compatible with
3245  * historical BSD practice is quite difficult in the face of
3246  * clusters/bigalloc.  This is because multiple metadata blocks from
3247  * different block group can end up in the same allocation cluster.
3248  * Calculating the exact overhead in the face of clustered allocation
3249  * requires either O(all block bitmaps) in memory or O(number of block
3250  * groups**2) in time.  We will still calculate the superblock for
3251  * older file systems --- and if we come across with a bigalloc file
3252  * system with zero in s_overhead_clusters the estimate will be close to
3253  * correct especially for very large cluster sizes --- but for newer
3254  * file systems, it's better to calculate this figure once at mkfs
3255  * time, and store it in the superblock.  If the superblock value is
3256  * present (even for non-bigalloc file systems), we will use it.
3257  */
3258 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3259 			  char *buf)
3260 {
3261 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3262 	struct ext4_group_desc	*gdp;
3263 	ext4_fsblk_t		first_block, last_block, b;
3264 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3265 	int			s, j, count = 0;
3266 
3267 	if (!ext4_has_feature_bigalloc(sb))
3268 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3269 			sbi->s_itb_per_group + 2);
3270 
3271 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3272 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3273 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3274 	for (i = 0; i < ngroups; i++) {
3275 		gdp = ext4_get_group_desc(sb, i, NULL);
3276 		b = ext4_block_bitmap(sb, gdp);
3277 		if (b >= first_block && b <= last_block) {
3278 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3279 			count++;
3280 		}
3281 		b = ext4_inode_bitmap(sb, gdp);
3282 		if (b >= first_block && b <= last_block) {
3283 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3284 			count++;
3285 		}
3286 		b = ext4_inode_table(sb, gdp);
3287 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3288 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3289 				int c = EXT4_B2C(sbi, b - first_block);
3290 				ext4_set_bit(c, buf);
3291 				count++;
3292 			}
3293 		if (i != grp)
3294 			continue;
3295 		s = 0;
3296 		if (ext4_bg_has_super(sb, grp)) {
3297 			ext4_set_bit(s++, buf);
3298 			count++;
3299 		}
3300 		j = ext4_bg_num_gdb(sb, grp);
3301 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3302 			ext4_error(sb, "Invalid number of block group "
3303 				   "descriptor blocks: %d", j);
3304 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3305 		}
3306 		count += j;
3307 		for (; j > 0; j--)
3308 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3309 	}
3310 	if (!count)
3311 		return 0;
3312 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3313 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3314 }
3315 
3316 /*
3317  * Compute the overhead and stash it in sbi->s_overhead
3318  */
3319 int ext4_calculate_overhead(struct super_block *sb)
3320 {
3321 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3322 	struct ext4_super_block *es = sbi->s_es;
3323 	struct inode *j_inode;
3324 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3325 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3326 	ext4_fsblk_t overhead = 0;
3327 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3328 
3329 	if (!buf)
3330 		return -ENOMEM;
3331 
3332 	/*
3333 	 * Compute the overhead (FS structures).  This is constant
3334 	 * for a given filesystem unless the number of block groups
3335 	 * changes so we cache the previous value until it does.
3336 	 */
3337 
3338 	/*
3339 	 * All of the blocks before first_data_block are overhead
3340 	 */
3341 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3342 
3343 	/*
3344 	 * Add the overhead found in each block group
3345 	 */
3346 	for (i = 0; i < ngroups; i++) {
3347 		int blks;
3348 
3349 		blks = count_overhead(sb, i, buf);
3350 		overhead += blks;
3351 		if (blks)
3352 			memset(buf, 0, PAGE_SIZE);
3353 		cond_resched();
3354 	}
3355 
3356 	/*
3357 	 * Add the internal journal blocks whether the journal has been
3358 	 * loaded or not
3359 	 */
3360 	if (sbi->s_journal && !sbi->journal_bdev)
3361 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3362 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3363 		j_inode = ext4_get_journal_inode(sb, j_inum);
3364 		if (j_inode) {
3365 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3366 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3367 			iput(j_inode);
3368 		} else {
3369 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3370 		}
3371 	}
3372 	sbi->s_overhead = overhead;
3373 	smp_wmb();
3374 	free_page((unsigned long) buf);
3375 	return 0;
3376 }
3377 
3378 static void ext4_set_resv_clusters(struct super_block *sb)
3379 {
3380 	ext4_fsblk_t resv_clusters;
3381 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3382 
3383 	/*
3384 	 * There's no need to reserve anything when we aren't using extents.
3385 	 * The space estimates are exact, there are no unwritten extents,
3386 	 * hole punching doesn't need new metadata... This is needed especially
3387 	 * to keep ext2/3 backward compatibility.
3388 	 */
3389 	if (!ext4_has_feature_extents(sb))
3390 		return;
3391 	/*
3392 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3393 	 * This should cover the situations where we can not afford to run
3394 	 * out of space like for example punch hole, or converting
3395 	 * unwritten extents in delalloc path. In most cases such
3396 	 * allocation would require 1, or 2 blocks, higher numbers are
3397 	 * very rare.
3398 	 */
3399 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3400 			 sbi->s_cluster_bits);
3401 
3402 	do_div(resv_clusters, 50);
3403 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3404 
3405 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3406 }
3407 
3408 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3409 {
3410 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3411 	char *orig_data = kstrdup(data, GFP_KERNEL);
3412 	struct buffer_head *bh;
3413 	struct ext4_super_block *es = NULL;
3414 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3415 	ext4_fsblk_t block;
3416 	ext4_fsblk_t sb_block = get_sb_block(&data);
3417 	ext4_fsblk_t logical_sb_block;
3418 	unsigned long offset = 0;
3419 	unsigned long journal_devnum = 0;
3420 	unsigned long def_mount_opts;
3421 	struct inode *root;
3422 	const char *descr;
3423 	int ret = -ENOMEM;
3424 	int blocksize, clustersize;
3425 	unsigned int db_count;
3426 	unsigned int i;
3427 	int needs_recovery, has_huge_files, has_bigalloc;
3428 	__u64 blocks_count;
3429 	int err = 0;
3430 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3431 	ext4_group_t first_not_zeroed;
3432 
3433 	if ((data && !orig_data) || !sbi)
3434 		goto out_free_base;
3435 
3436 	sbi->s_daxdev = dax_dev;
3437 	sbi->s_blockgroup_lock =
3438 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3439 	if (!sbi->s_blockgroup_lock)
3440 		goto out_free_base;
3441 
3442 	sb->s_fs_info = sbi;
3443 	sbi->s_sb = sb;
3444 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3445 	sbi->s_sb_block = sb_block;
3446 	if (sb->s_bdev->bd_part)
3447 		sbi->s_sectors_written_start =
3448 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3449 
3450 	/* Cleanup superblock name */
3451 	strreplace(sb->s_id, '/', '!');
3452 
3453 	/* -EINVAL is default */
3454 	ret = -EINVAL;
3455 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3456 	if (!blocksize) {
3457 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3458 		goto out_fail;
3459 	}
3460 
3461 	/*
3462 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3463 	 * block sizes.  We need to calculate the offset from buffer start.
3464 	 */
3465 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3466 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3467 		offset = do_div(logical_sb_block, blocksize);
3468 	} else {
3469 		logical_sb_block = sb_block;
3470 	}
3471 
3472 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3473 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3474 		goto out_fail;
3475 	}
3476 	/*
3477 	 * Note: s_es must be initialized as soon as possible because
3478 	 *       some ext4 macro-instructions depend on its value
3479 	 */
3480 	es = (struct ext4_super_block *) (bh->b_data + offset);
3481 	sbi->s_es = es;
3482 	sb->s_magic = le16_to_cpu(es->s_magic);
3483 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3484 		goto cantfind_ext4;
3485 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3486 
3487 	/* Warn if metadata_csum and gdt_csum are both set. */
3488 	if (ext4_has_feature_metadata_csum(sb) &&
3489 	    ext4_has_feature_gdt_csum(sb))
3490 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3491 			     "redundant flags; please run fsck.");
3492 
3493 	/* Check for a known checksum algorithm */
3494 	if (!ext4_verify_csum_type(sb, es)) {
3495 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3496 			 "unknown checksum algorithm.");
3497 		silent = 1;
3498 		goto cantfind_ext4;
3499 	}
3500 
3501 	/* Load the checksum driver */
3502 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3503 	if (IS_ERR(sbi->s_chksum_driver)) {
3504 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3505 		ret = PTR_ERR(sbi->s_chksum_driver);
3506 		sbi->s_chksum_driver = NULL;
3507 		goto failed_mount;
3508 	}
3509 
3510 	/* Check superblock checksum */
3511 	if (!ext4_superblock_csum_verify(sb, es)) {
3512 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3513 			 "invalid superblock checksum.  Run e2fsck?");
3514 		silent = 1;
3515 		ret = -EFSBADCRC;
3516 		goto cantfind_ext4;
3517 	}
3518 
3519 	/* Precompute checksum seed for all metadata */
3520 	if (ext4_has_feature_csum_seed(sb))
3521 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3522 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3523 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3524 					       sizeof(es->s_uuid));
3525 
3526 	/* Set defaults before we parse the mount options */
3527 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3528 	set_opt(sb, INIT_INODE_TABLE);
3529 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3530 		set_opt(sb, DEBUG);
3531 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3532 		set_opt(sb, GRPID);
3533 	if (def_mount_opts & EXT4_DEFM_UID16)
3534 		set_opt(sb, NO_UID32);
3535 	/* xattr user namespace & acls are now defaulted on */
3536 	set_opt(sb, XATTR_USER);
3537 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3538 	set_opt(sb, POSIX_ACL);
3539 #endif
3540 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3541 	if (ext4_has_metadata_csum(sb))
3542 		set_opt(sb, JOURNAL_CHECKSUM);
3543 
3544 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3545 		set_opt(sb, JOURNAL_DATA);
3546 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3547 		set_opt(sb, ORDERED_DATA);
3548 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3549 		set_opt(sb, WRITEBACK_DATA);
3550 
3551 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3552 		set_opt(sb, ERRORS_PANIC);
3553 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3554 		set_opt(sb, ERRORS_CONT);
3555 	else
3556 		set_opt(sb, ERRORS_RO);
3557 	/* block_validity enabled by default; disable with noblock_validity */
3558 	set_opt(sb, BLOCK_VALIDITY);
3559 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3560 		set_opt(sb, DISCARD);
3561 
3562 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3563 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3564 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3565 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3566 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3567 
3568 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3569 		set_opt(sb, BARRIER);
3570 
3571 	/*
3572 	 * enable delayed allocation by default
3573 	 * Use -o nodelalloc to turn it off
3574 	 */
3575 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3576 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3577 		set_opt(sb, DELALLOC);
3578 
3579 	/*
3580 	 * set default s_li_wait_mult for lazyinit, for the case there is
3581 	 * no mount option specified.
3582 	 */
3583 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3584 
3585 	if (sbi->s_es->s_mount_opts[0]) {
3586 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3587 					      sizeof(sbi->s_es->s_mount_opts),
3588 					      GFP_KERNEL);
3589 		if (!s_mount_opts)
3590 			goto failed_mount;
3591 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3592 				   &journal_ioprio, 0)) {
3593 			ext4_msg(sb, KERN_WARNING,
3594 				 "failed to parse options in superblock: %s",
3595 				 s_mount_opts);
3596 		}
3597 		kfree(s_mount_opts);
3598 	}
3599 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3600 	if (!parse_options((char *) data, sb, &journal_devnum,
3601 			   &journal_ioprio, 0))
3602 		goto failed_mount;
3603 
3604 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3605 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3606 			    "with data=journal disables delayed "
3607 			    "allocation and O_DIRECT support!\n");
3608 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3609 			ext4_msg(sb, KERN_ERR, "can't mount with "
3610 				 "both data=journal and delalloc");
3611 			goto failed_mount;
3612 		}
3613 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3614 			ext4_msg(sb, KERN_ERR, "can't mount with "
3615 				 "both data=journal and dioread_nolock");
3616 			goto failed_mount;
3617 		}
3618 		if (test_opt(sb, DAX)) {
3619 			ext4_msg(sb, KERN_ERR, "can't mount with "
3620 				 "both data=journal and dax");
3621 			goto failed_mount;
3622 		}
3623 		if (ext4_has_feature_encrypt(sb)) {
3624 			ext4_msg(sb, KERN_WARNING,
3625 				 "encrypted files will use data=ordered "
3626 				 "instead of data journaling mode");
3627 		}
3628 		if (test_opt(sb, DELALLOC))
3629 			clear_opt(sb, DELALLOC);
3630 	} else {
3631 		sb->s_iflags |= SB_I_CGROUPWB;
3632 	}
3633 
3634 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3635 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3636 
3637 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3638 	    (ext4_has_compat_features(sb) ||
3639 	     ext4_has_ro_compat_features(sb) ||
3640 	     ext4_has_incompat_features(sb)))
3641 		ext4_msg(sb, KERN_WARNING,
3642 		       "feature flags set on rev 0 fs, "
3643 		       "running e2fsck is recommended");
3644 
3645 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3646 		set_opt2(sb, HURD_COMPAT);
3647 		if (ext4_has_feature_64bit(sb)) {
3648 			ext4_msg(sb, KERN_ERR,
3649 				 "The Hurd can't support 64-bit file systems");
3650 			goto failed_mount;
3651 		}
3652 
3653 		/*
3654 		 * ea_inode feature uses l_i_version field which is not
3655 		 * available in HURD_COMPAT mode.
3656 		 */
3657 		if (ext4_has_feature_ea_inode(sb)) {
3658 			ext4_msg(sb, KERN_ERR,
3659 				 "ea_inode feature is not supported for Hurd");
3660 			goto failed_mount;
3661 		}
3662 	}
3663 
3664 	if (IS_EXT2_SB(sb)) {
3665 		if (ext2_feature_set_ok(sb))
3666 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3667 				 "using the ext4 subsystem");
3668 		else {
3669 			/*
3670 			 * If we're probing be silent, if this looks like
3671 			 * it's actually an ext[34] filesystem.
3672 			 */
3673 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3674 				goto failed_mount;
3675 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3676 				 "to feature incompatibilities");
3677 			goto failed_mount;
3678 		}
3679 	}
3680 
3681 	if (IS_EXT3_SB(sb)) {
3682 		if (ext3_feature_set_ok(sb))
3683 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3684 				 "using the ext4 subsystem");
3685 		else {
3686 			/*
3687 			 * If we're probing be silent, if this looks like
3688 			 * it's actually an ext4 filesystem.
3689 			 */
3690 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3691 				goto failed_mount;
3692 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3693 				 "to feature incompatibilities");
3694 			goto failed_mount;
3695 		}
3696 	}
3697 
3698 	/*
3699 	 * Check feature flags regardless of the revision level, since we
3700 	 * previously didn't change the revision level when setting the flags,
3701 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3702 	 */
3703 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3704 		goto failed_mount;
3705 
3706 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3707 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3708 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3709 		ext4_msg(sb, KERN_ERR,
3710 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3711 			 blocksize, le32_to_cpu(es->s_log_block_size));
3712 		goto failed_mount;
3713 	}
3714 	if (le32_to_cpu(es->s_log_block_size) >
3715 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3716 		ext4_msg(sb, KERN_ERR,
3717 			 "Invalid log block size: %u",
3718 			 le32_to_cpu(es->s_log_block_size));
3719 		goto failed_mount;
3720 	}
3721 
3722 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3723 		ext4_msg(sb, KERN_ERR,
3724 			 "Number of reserved GDT blocks insanely large: %d",
3725 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3726 		goto failed_mount;
3727 	}
3728 
3729 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3730 		if (ext4_has_feature_inline_data(sb)) {
3731 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3732 					" that may contain inline data");
3733 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
3734 		}
3735 		err = bdev_dax_supported(sb, blocksize);
3736 		if (err) {
3737 			ext4_msg(sb, KERN_ERR,
3738 				"DAX unsupported by block device. Turning off DAX.");
3739 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
3740 		}
3741 	}
3742 
3743 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3744 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3745 			 es->s_encryption_level);
3746 		goto failed_mount;
3747 	}
3748 
3749 	if (sb->s_blocksize != blocksize) {
3750 		/* Validate the filesystem blocksize */
3751 		if (!sb_set_blocksize(sb, blocksize)) {
3752 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3753 					blocksize);
3754 			goto failed_mount;
3755 		}
3756 
3757 		brelse(bh);
3758 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3759 		offset = do_div(logical_sb_block, blocksize);
3760 		bh = sb_bread_unmovable(sb, logical_sb_block);
3761 		if (!bh) {
3762 			ext4_msg(sb, KERN_ERR,
3763 			       "Can't read superblock on 2nd try");
3764 			goto failed_mount;
3765 		}
3766 		es = (struct ext4_super_block *)(bh->b_data + offset);
3767 		sbi->s_es = es;
3768 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3769 			ext4_msg(sb, KERN_ERR,
3770 			       "Magic mismatch, very weird!");
3771 			goto failed_mount;
3772 		}
3773 	}
3774 
3775 	has_huge_files = ext4_has_feature_huge_file(sb);
3776 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3777 						      has_huge_files);
3778 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3779 
3780 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3781 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3782 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3783 	} else {
3784 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3785 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3786 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3787 		    (!is_power_of_2(sbi->s_inode_size)) ||
3788 		    (sbi->s_inode_size > blocksize)) {
3789 			ext4_msg(sb, KERN_ERR,
3790 			       "unsupported inode size: %d",
3791 			       sbi->s_inode_size);
3792 			goto failed_mount;
3793 		}
3794 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3795 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3796 	}
3797 
3798 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3799 	if (ext4_has_feature_64bit(sb)) {
3800 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3801 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3802 		    !is_power_of_2(sbi->s_desc_size)) {
3803 			ext4_msg(sb, KERN_ERR,
3804 			       "unsupported descriptor size %lu",
3805 			       sbi->s_desc_size);
3806 			goto failed_mount;
3807 		}
3808 	} else
3809 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3810 
3811 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3812 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3813 
3814 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3815 	if (sbi->s_inodes_per_block == 0)
3816 		goto cantfind_ext4;
3817 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3818 	    sbi->s_inodes_per_group > blocksize * 8) {
3819 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3820 			 sbi->s_blocks_per_group);
3821 		goto failed_mount;
3822 	}
3823 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3824 					sbi->s_inodes_per_block;
3825 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3826 	sbi->s_sbh = bh;
3827 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3828 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3829 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3830 
3831 	for (i = 0; i < 4; i++)
3832 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3833 	sbi->s_def_hash_version = es->s_def_hash_version;
3834 	if (ext4_has_feature_dir_index(sb)) {
3835 		i = le32_to_cpu(es->s_flags);
3836 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3837 			sbi->s_hash_unsigned = 3;
3838 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3839 #ifdef __CHAR_UNSIGNED__
3840 			if (!sb_rdonly(sb))
3841 				es->s_flags |=
3842 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3843 			sbi->s_hash_unsigned = 3;
3844 #else
3845 			if (!sb_rdonly(sb))
3846 				es->s_flags |=
3847 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3848 #endif
3849 		}
3850 	}
3851 
3852 	/* Handle clustersize */
3853 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3854 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3855 	if (has_bigalloc) {
3856 		if (clustersize < blocksize) {
3857 			ext4_msg(sb, KERN_ERR,
3858 				 "cluster size (%d) smaller than "
3859 				 "block size (%d)", clustersize, blocksize);
3860 			goto failed_mount;
3861 		}
3862 		if (le32_to_cpu(es->s_log_cluster_size) >
3863 		    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3864 			ext4_msg(sb, KERN_ERR,
3865 				 "Invalid log cluster size: %u",
3866 				 le32_to_cpu(es->s_log_cluster_size));
3867 			goto failed_mount;
3868 		}
3869 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3870 			le32_to_cpu(es->s_log_block_size);
3871 		sbi->s_clusters_per_group =
3872 			le32_to_cpu(es->s_clusters_per_group);
3873 		if (sbi->s_clusters_per_group > blocksize * 8) {
3874 			ext4_msg(sb, KERN_ERR,
3875 				 "#clusters per group too big: %lu",
3876 				 sbi->s_clusters_per_group);
3877 			goto failed_mount;
3878 		}
3879 		if (sbi->s_blocks_per_group !=
3880 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3881 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3882 				 "clusters per group (%lu) inconsistent",
3883 				 sbi->s_blocks_per_group,
3884 				 sbi->s_clusters_per_group);
3885 			goto failed_mount;
3886 		}
3887 	} else {
3888 		if (clustersize != blocksize) {
3889 			ext4_warning(sb, "fragment/cluster size (%d) != "
3890 				     "block size (%d)", clustersize,
3891 				     blocksize);
3892 			clustersize = blocksize;
3893 		}
3894 		if (sbi->s_blocks_per_group > blocksize * 8) {
3895 			ext4_msg(sb, KERN_ERR,
3896 				 "#blocks per group too big: %lu",
3897 				 sbi->s_blocks_per_group);
3898 			goto failed_mount;
3899 		}
3900 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3901 		sbi->s_cluster_bits = 0;
3902 	}
3903 	sbi->s_cluster_ratio = clustersize / blocksize;
3904 
3905 	/* Do we have standard group size of clustersize * 8 blocks ? */
3906 	if (sbi->s_blocks_per_group == clustersize << 3)
3907 		set_opt2(sb, STD_GROUP_SIZE);
3908 
3909 	/*
3910 	 * Test whether we have more sectors than will fit in sector_t,
3911 	 * and whether the max offset is addressable by the page cache.
3912 	 */
3913 	err = generic_check_addressable(sb->s_blocksize_bits,
3914 					ext4_blocks_count(es));
3915 	if (err) {
3916 		ext4_msg(sb, KERN_ERR, "filesystem"
3917 			 " too large to mount safely on this system");
3918 		if (sizeof(sector_t) < 8)
3919 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3920 		goto failed_mount;
3921 	}
3922 
3923 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3924 		goto cantfind_ext4;
3925 
3926 	/* check blocks count against device size */
3927 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3928 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3929 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3930 		       "exceeds size of device (%llu blocks)",
3931 		       ext4_blocks_count(es), blocks_count);
3932 		goto failed_mount;
3933 	}
3934 
3935 	/*
3936 	 * It makes no sense for the first data block to be beyond the end
3937 	 * of the filesystem.
3938 	 */
3939 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3940 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3941 			 "block %u is beyond end of filesystem (%llu)",
3942 			 le32_to_cpu(es->s_first_data_block),
3943 			 ext4_blocks_count(es));
3944 		goto failed_mount;
3945 	}
3946 	blocks_count = (ext4_blocks_count(es) -
3947 			le32_to_cpu(es->s_first_data_block) +
3948 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3949 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3950 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3951 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3952 		       "(block count %llu, first data block %u, "
3953 		       "blocks per group %lu)", sbi->s_groups_count,
3954 		       ext4_blocks_count(es),
3955 		       le32_to_cpu(es->s_first_data_block),
3956 		       EXT4_BLOCKS_PER_GROUP(sb));
3957 		goto failed_mount;
3958 	}
3959 	sbi->s_groups_count = blocks_count;
3960 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3961 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3962 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3963 		   EXT4_DESC_PER_BLOCK(sb);
3964 	if (ext4_has_feature_meta_bg(sb)) {
3965 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3966 			ext4_msg(sb, KERN_WARNING,
3967 				 "first meta block group too large: %u "
3968 				 "(group descriptor block count %u)",
3969 				 le32_to_cpu(es->s_first_meta_bg), db_count);
3970 			goto failed_mount;
3971 		}
3972 	}
3973 	sbi->s_group_desc = kvmalloc(db_count *
3974 					  sizeof(struct buffer_head *),
3975 					  GFP_KERNEL);
3976 	if (sbi->s_group_desc == NULL) {
3977 		ext4_msg(sb, KERN_ERR, "not enough memory");
3978 		ret = -ENOMEM;
3979 		goto failed_mount;
3980 	}
3981 
3982 	bgl_lock_init(sbi->s_blockgroup_lock);
3983 
3984 	/* Pre-read the descriptors into the buffer cache */
3985 	for (i = 0; i < db_count; i++) {
3986 		block = descriptor_loc(sb, logical_sb_block, i);
3987 		sb_breadahead(sb, block);
3988 	}
3989 
3990 	for (i = 0; i < db_count; i++) {
3991 		block = descriptor_loc(sb, logical_sb_block, i);
3992 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3993 		if (!sbi->s_group_desc[i]) {
3994 			ext4_msg(sb, KERN_ERR,
3995 			       "can't read group descriptor %d", i);
3996 			db_count = i;
3997 			goto failed_mount2;
3998 		}
3999 	}
4000 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4001 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4002 		ret = -EFSCORRUPTED;
4003 		goto failed_mount2;
4004 	}
4005 
4006 	sbi->s_gdb_count = db_count;
4007 
4008 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4009 
4010 	/* Register extent status tree shrinker */
4011 	if (ext4_es_register_shrinker(sbi))
4012 		goto failed_mount3;
4013 
4014 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4015 	sbi->s_extent_max_zeroout_kb = 32;
4016 
4017 	/*
4018 	 * set up enough so that it can read an inode
4019 	 */
4020 	sb->s_op = &ext4_sops;
4021 	sb->s_export_op = &ext4_export_ops;
4022 	sb->s_xattr = ext4_xattr_handlers;
4023 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4024 	sb->s_cop = &ext4_cryptops;
4025 #endif
4026 #ifdef CONFIG_QUOTA
4027 	sb->dq_op = &ext4_quota_operations;
4028 	if (ext4_has_feature_quota(sb))
4029 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4030 	else
4031 		sb->s_qcop = &ext4_qctl_operations;
4032 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4033 #endif
4034 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4035 
4036 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4037 	mutex_init(&sbi->s_orphan_lock);
4038 
4039 	sb->s_root = NULL;
4040 
4041 	needs_recovery = (es->s_last_orphan != 0 ||
4042 			  ext4_has_feature_journal_needs_recovery(sb));
4043 
4044 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4045 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4046 			goto failed_mount3a;
4047 
4048 	/*
4049 	 * The first inode we look at is the journal inode.  Don't try
4050 	 * root first: it may be modified in the journal!
4051 	 */
4052 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4053 		err = ext4_load_journal(sb, es, journal_devnum);
4054 		if (err)
4055 			goto failed_mount3a;
4056 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4057 		   ext4_has_feature_journal_needs_recovery(sb)) {
4058 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4059 		       "suppressed and not mounted read-only");
4060 		goto failed_mount_wq;
4061 	} else {
4062 		/* Nojournal mode, all journal mount options are illegal */
4063 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4064 			ext4_msg(sb, KERN_ERR, "can't mount with "
4065 				 "journal_checksum, fs mounted w/o journal");
4066 			goto failed_mount_wq;
4067 		}
4068 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4069 			ext4_msg(sb, KERN_ERR, "can't mount with "
4070 				 "journal_async_commit, fs mounted w/o journal");
4071 			goto failed_mount_wq;
4072 		}
4073 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4074 			ext4_msg(sb, KERN_ERR, "can't mount with "
4075 				 "commit=%lu, fs mounted w/o journal",
4076 				 sbi->s_commit_interval / HZ);
4077 			goto failed_mount_wq;
4078 		}
4079 		if (EXT4_MOUNT_DATA_FLAGS &
4080 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4081 			ext4_msg(sb, KERN_ERR, "can't mount with "
4082 				 "data=, fs mounted w/o journal");
4083 			goto failed_mount_wq;
4084 		}
4085 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4086 		clear_opt(sb, JOURNAL_CHECKSUM);
4087 		clear_opt(sb, DATA_FLAGS);
4088 		sbi->s_journal = NULL;
4089 		needs_recovery = 0;
4090 		goto no_journal;
4091 	}
4092 
4093 	if (ext4_has_feature_64bit(sb) &&
4094 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4095 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4096 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4097 		goto failed_mount_wq;
4098 	}
4099 
4100 	if (!set_journal_csum_feature_set(sb)) {
4101 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4102 			 "feature set");
4103 		goto failed_mount_wq;
4104 	}
4105 
4106 	/* We have now updated the journal if required, so we can
4107 	 * validate the data journaling mode. */
4108 	switch (test_opt(sb, DATA_FLAGS)) {
4109 	case 0:
4110 		/* No mode set, assume a default based on the journal
4111 		 * capabilities: ORDERED_DATA if the journal can
4112 		 * cope, else JOURNAL_DATA
4113 		 */
4114 		if (jbd2_journal_check_available_features
4115 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4116 			set_opt(sb, ORDERED_DATA);
4117 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4118 		} else {
4119 			set_opt(sb, JOURNAL_DATA);
4120 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4121 		}
4122 		break;
4123 
4124 	case EXT4_MOUNT_ORDERED_DATA:
4125 	case EXT4_MOUNT_WRITEBACK_DATA:
4126 		if (!jbd2_journal_check_available_features
4127 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4128 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4129 			       "requested data journaling mode");
4130 			goto failed_mount_wq;
4131 		}
4132 	default:
4133 		break;
4134 	}
4135 
4136 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4137 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4138 		ext4_msg(sb, KERN_ERR, "can't mount with "
4139 			"journal_async_commit in data=ordered mode");
4140 		goto failed_mount_wq;
4141 	}
4142 
4143 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4144 
4145 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4146 
4147 no_journal:
4148 	if (!test_opt(sb, NO_MBCACHE)) {
4149 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4150 		if (!sbi->s_ea_block_cache) {
4151 			ext4_msg(sb, KERN_ERR,
4152 				 "Failed to create ea_block_cache");
4153 			goto failed_mount_wq;
4154 		}
4155 
4156 		if (ext4_has_feature_ea_inode(sb)) {
4157 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4158 			if (!sbi->s_ea_inode_cache) {
4159 				ext4_msg(sb, KERN_ERR,
4160 					 "Failed to create ea_inode_cache");
4161 				goto failed_mount_wq;
4162 			}
4163 		}
4164 	}
4165 
4166 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4167 	    (blocksize != PAGE_SIZE)) {
4168 		ext4_msg(sb, KERN_ERR,
4169 			 "Unsupported blocksize for fs encryption");
4170 		goto failed_mount_wq;
4171 	}
4172 
4173 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4174 	    !ext4_has_feature_encrypt(sb)) {
4175 		ext4_set_feature_encrypt(sb);
4176 		ext4_commit_super(sb, 1);
4177 	}
4178 
4179 	/*
4180 	 * Get the # of file system overhead blocks from the
4181 	 * superblock if present.
4182 	 */
4183 	if (es->s_overhead_clusters)
4184 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4185 	else {
4186 		err = ext4_calculate_overhead(sb);
4187 		if (err)
4188 			goto failed_mount_wq;
4189 	}
4190 
4191 	/*
4192 	 * The maximum number of concurrent works can be high and
4193 	 * concurrency isn't really necessary.  Limit it to 1.
4194 	 */
4195 	EXT4_SB(sb)->rsv_conversion_wq =
4196 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4197 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4198 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4199 		ret = -ENOMEM;
4200 		goto failed_mount4;
4201 	}
4202 
4203 	/*
4204 	 * The jbd2_journal_load will have done any necessary log recovery,
4205 	 * so we can safely mount the rest of the filesystem now.
4206 	 */
4207 
4208 	root = ext4_iget(sb, EXT4_ROOT_INO);
4209 	if (IS_ERR(root)) {
4210 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4211 		ret = PTR_ERR(root);
4212 		root = NULL;
4213 		goto failed_mount4;
4214 	}
4215 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4216 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4217 		iput(root);
4218 		goto failed_mount4;
4219 	}
4220 	sb->s_root = d_make_root(root);
4221 	if (!sb->s_root) {
4222 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4223 		ret = -ENOMEM;
4224 		goto failed_mount4;
4225 	}
4226 
4227 	if (ext4_setup_super(sb, es, sb_rdonly(sb)))
4228 		sb->s_flags |= SB_RDONLY;
4229 
4230 	/* determine the minimum size of new large inodes, if present */
4231 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4232 	    sbi->s_want_extra_isize == 0) {
4233 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4234 						     EXT4_GOOD_OLD_INODE_SIZE;
4235 		if (ext4_has_feature_extra_isize(sb)) {
4236 			if (sbi->s_want_extra_isize <
4237 			    le16_to_cpu(es->s_want_extra_isize))
4238 				sbi->s_want_extra_isize =
4239 					le16_to_cpu(es->s_want_extra_isize);
4240 			if (sbi->s_want_extra_isize <
4241 			    le16_to_cpu(es->s_min_extra_isize))
4242 				sbi->s_want_extra_isize =
4243 					le16_to_cpu(es->s_min_extra_isize);
4244 		}
4245 	}
4246 	/* Check if enough inode space is available */
4247 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4248 							sbi->s_inode_size) {
4249 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4250 						       EXT4_GOOD_OLD_INODE_SIZE;
4251 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4252 			 "available");
4253 	}
4254 
4255 	ext4_set_resv_clusters(sb);
4256 
4257 	err = ext4_setup_system_zone(sb);
4258 	if (err) {
4259 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4260 			 "zone (%d)", err);
4261 		goto failed_mount4a;
4262 	}
4263 
4264 	ext4_ext_init(sb);
4265 	err = ext4_mb_init(sb);
4266 	if (err) {
4267 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4268 			 err);
4269 		goto failed_mount5;
4270 	}
4271 
4272 	block = ext4_count_free_clusters(sb);
4273 	ext4_free_blocks_count_set(sbi->s_es,
4274 				   EXT4_C2B(sbi, block));
4275 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4276 				  GFP_KERNEL);
4277 	if (!err) {
4278 		unsigned long freei = ext4_count_free_inodes(sb);
4279 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4280 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4281 					  GFP_KERNEL);
4282 	}
4283 	if (!err)
4284 		err = percpu_counter_init(&sbi->s_dirs_counter,
4285 					  ext4_count_dirs(sb), GFP_KERNEL);
4286 	if (!err)
4287 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4288 					  GFP_KERNEL);
4289 	if (!err)
4290 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4291 
4292 	if (err) {
4293 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4294 		goto failed_mount6;
4295 	}
4296 
4297 	if (ext4_has_feature_flex_bg(sb))
4298 		if (!ext4_fill_flex_info(sb)) {
4299 			ext4_msg(sb, KERN_ERR,
4300 			       "unable to initialize "
4301 			       "flex_bg meta info!");
4302 			goto failed_mount6;
4303 		}
4304 
4305 	err = ext4_register_li_request(sb, first_not_zeroed);
4306 	if (err)
4307 		goto failed_mount6;
4308 
4309 	err = ext4_register_sysfs(sb);
4310 	if (err)
4311 		goto failed_mount7;
4312 
4313 #ifdef CONFIG_QUOTA
4314 	/* Enable quota usage during mount. */
4315 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4316 		err = ext4_enable_quotas(sb);
4317 		if (err)
4318 			goto failed_mount8;
4319 	}
4320 #endif  /* CONFIG_QUOTA */
4321 
4322 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4323 	ext4_orphan_cleanup(sb, es);
4324 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4325 	if (needs_recovery) {
4326 		ext4_msg(sb, KERN_INFO, "recovery complete");
4327 		ext4_mark_recovery_complete(sb, es);
4328 	}
4329 	if (EXT4_SB(sb)->s_journal) {
4330 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4331 			descr = " journalled data mode";
4332 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4333 			descr = " ordered data mode";
4334 		else
4335 			descr = " writeback data mode";
4336 	} else
4337 		descr = "out journal";
4338 
4339 	if (test_opt(sb, DISCARD)) {
4340 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4341 		if (!blk_queue_discard(q))
4342 			ext4_msg(sb, KERN_WARNING,
4343 				 "mounting with \"discard\" option, but "
4344 				 "the device does not support discard");
4345 	}
4346 
4347 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4348 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4349 			 "Opts: %.*s%s%s", descr,
4350 			 (int) sizeof(sbi->s_es->s_mount_opts),
4351 			 sbi->s_es->s_mount_opts,
4352 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4353 
4354 	if (es->s_error_count)
4355 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4356 
4357 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4358 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4359 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4360 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4361 
4362 	kfree(orig_data);
4363 	return 0;
4364 
4365 cantfind_ext4:
4366 	if (!silent)
4367 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4368 	goto failed_mount;
4369 
4370 #ifdef CONFIG_QUOTA
4371 failed_mount8:
4372 	ext4_unregister_sysfs(sb);
4373 #endif
4374 failed_mount7:
4375 	ext4_unregister_li_request(sb);
4376 failed_mount6:
4377 	ext4_mb_release(sb);
4378 	if (sbi->s_flex_groups)
4379 		kvfree(sbi->s_flex_groups);
4380 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4381 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4382 	percpu_counter_destroy(&sbi->s_dirs_counter);
4383 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4384 failed_mount5:
4385 	ext4_ext_release(sb);
4386 	ext4_release_system_zone(sb);
4387 failed_mount4a:
4388 	dput(sb->s_root);
4389 	sb->s_root = NULL;
4390 failed_mount4:
4391 	ext4_msg(sb, KERN_ERR, "mount failed");
4392 	if (EXT4_SB(sb)->rsv_conversion_wq)
4393 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4394 failed_mount_wq:
4395 	if (sbi->s_ea_inode_cache) {
4396 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4397 		sbi->s_ea_inode_cache = NULL;
4398 	}
4399 	if (sbi->s_ea_block_cache) {
4400 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4401 		sbi->s_ea_block_cache = NULL;
4402 	}
4403 	if (sbi->s_journal) {
4404 		jbd2_journal_destroy(sbi->s_journal);
4405 		sbi->s_journal = NULL;
4406 	}
4407 failed_mount3a:
4408 	ext4_es_unregister_shrinker(sbi);
4409 failed_mount3:
4410 	del_timer_sync(&sbi->s_err_report);
4411 	if (sbi->s_mmp_tsk)
4412 		kthread_stop(sbi->s_mmp_tsk);
4413 failed_mount2:
4414 	for (i = 0; i < db_count; i++)
4415 		brelse(sbi->s_group_desc[i]);
4416 	kvfree(sbi->s_group_desc);
4417 failed_mount:
4418 	if (sbi->s_chksum_driver)
4419 		crypto_free_shash(sbi->s_chksum_driver);
4420 #ifdef CONFIG_QUOTA
4421 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4422 		kfree(sbi->s_qf_names[i]);
4423 #endif
4424 	ext4_blkdev_remove(sbi);
4425 	brelse(bh);
4426 out_fail:
4427 	sb->s_fs_info = NULL;
4428 	kfree(sbi->s_blockgroup_lock);
4429 out_free_base:
4430 	kfree(sbi);
4431 	kfree(orig_data);
4432 	fs_put_dax(dax_dev);
4433 	return err ? err : ret;
4434 }
4435 
4436 /*
4437  * Setup any per-fs journal parameters now.  We'll do this both on
4438  * initial mount, once the journal has been initialised but before we've
4439  * done any recovery; and again on any subsequent remount.
4440  */
4441 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4442 {
4443 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4444 
4445 	journal->j_commit_interval = sbi->s_commit_interval;
4446 	journal->j_min_batch_time = sbi->s_min_batch_time;
4447 	journal->j_max_batch_time = sbi->s_max_batch_time;
4448 
4449 	write_lock(&journal->j_state_lock);
4450 	if (test_opt(sb, BARRIER))
4451 		journal->j_flags |= JBD2_BARRIER;
4452 	else
4453 		journal->j_flags &= ~JBD2_BARRIER;
4454 	if (test_opt(sb, DATA_ERR_ABORT))
4455 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4456 	else
4457 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4458 	write_unlock(&journal->j_state_lock);
4459 }
4460 
4461 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4462 					     unsigned int journal_inum)
4463 {
4464 	struct inode *journal_inode;
4465 
4466 	/*
4467 	 * Test for the existence of a valid inode on disk.  Bad things
4468 	 * happen if we iget() an unused inode, as the subsequent iput()
4469 	 * will try to delete it.
4470 	 */
4471 	journal_inode = ext4_iget(sb, journal_inum);
4472 	if (IS_ERR(journal_inode)) {
4473 		ext4_msg(sb, KERN_ERR, "no journal found");
4474 		return NULL;
4475 	}
4476 	if (!journal_inode->i_nlink) {
4477 		make_bad_inode(journal_inode);
4478 		iput(journal_inode);
4479 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4480 		return NULL;
4481 	}
4482 
4483 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4484 		  journal_inode, journal_inode->i_size);
4485 	if (!S_ISREG(journal_inode->i_mode)) {
4486 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4487 		iput(journal_inode);
4488 		return NULL;
4489 	}
4490 	return journal_inode;
4491 }
4492 
4493 static journal_t *ext4_get_journal(struct super_block *sb,
4494 				   unsigned int journal_inum)
4495 {
4496 	struct inode *journal_inode;
4497 	journal_t *journal;
4498 
4499 	BUG_ON(!ext4_has_feature_journal(sb));
4500 
4501 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4502 	if (!journal_inode)
4503 		return NULL;
4504 
4505 	journal = jbd2_journal_init_inode(journal_inode);
4506 	if (!journal) {
4507 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4508 		iput(journal_inode);
4509 		return NULL;
4510 	}
4511 	journal->j_private = sb;
4512 	ext4_init_journal_params(sb, journal);
4513 	return journal;
4514 }
4515 
4516 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4517 				       dev_t j_dev)
4518 {
4519 	struct buffer_head *bh;
4520 	journal_t *journal;
4521 	ext4_fsblk_t start;
4522 	ext4_fsblk_t len;
4523 	int hblock, blocksize;
4524 	ext4_fsblk_t sb_block;
4525 	unsigned long offset;
4526 	struct ext4_super_block *es;
4527 	struct block_device *bdev;
4528 
4529 	BUG_ON(!ext4_has_feature_journal(sb));
4530 
4531 	bdev = ext4_blkdev_get(j_dev, sb);
4532 	if (bdev == NULL)
4533 		return NULL;
4534 
4535 	blocksize = sb->s_blocksize;
4536 	hblock = bdev_logical_block_size(bdev);
4537 	if (blocksize < hblock) {
4538 		ext4_msg(sb, KERN_ERR,
4539 			"blocksize too small for journal device");
4540 		goto out_bdev;
4541 	}
4542 
4543 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4544 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4545 	set_blocksize(bdev, blocksize);
4546 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4547 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4548 		       "external journal");
4549 		goto out_bdev;
4550 	}
4551 
4552 	es = (struct ext4_super_block *) (bh->b_data + offset);
4553 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4554 	    !(le32_to_cpu(es->s_feature_incompat) &
4555 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4556 		ext4_msg(sb, KERN_ERR, "external journal has "
4557 					"bad superblock");
4558 		brelse(bh);
4559 		goto out_bdev;
4560 	}
4561 
4562 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4563 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4564 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4565 		ext4_msg(sb, KERN_ERR, "external journal has "
4566 				       "corrupt superblock");
4567 		brelse(bh);
4568 		goto out_bdev;
4569 	}
4570 
4571 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4572 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4573 		brelse(bh);
4574 		goto out_bdev;
4575 	}
4576 
4577 	len = ext4_blocks_count(es);
4578 	start = sb_block + 1;
4579 	brelse(bh);	/* we're done with the superblock */
4580 
4581 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4582 					start, len, blocksize);
4583 	if (!journal) {
4584 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4585 		goto out_bdev;
4586 	}
4587 	journal->j_private = sb;
4588 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4589 	wait_on_buffer(journal->j_sb_buffer);
4590 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4591 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4592 		goto out_journal;
4593 	}
4594 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4595 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4596 					"user (unsupported) - %d",
4597 			be32_to_cpu(journal->j_superblock->s_nr_users));
4598 		goto out_journal;
4599 	}
4600 	EXT4_SB(sb)->journal_bdev = bdev;
4601 	ext4_init_journal_params(sb, journal);
4602 	return journal;
4603 
4604 out_journal:
4605 	jbd2_journal_destroy(journal);
4606 out_bdev:
4607 	ext4_blkdev_put(bdev);
4608 	return NULL;
4609 }
4610 
4611 static int ext4_load_journal(struct super_block *sb,
4612 			     struct ext4_super_block *es,
4613 			     unsigned long journal_devnum)
4614 {
4615 	journal_t *journal;
4616 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4617 	dev_t journal_dev;
4618 	int err = 0;
4619 	int really_read_only;
4620 
4621 	BUG_ON(!ext4_has_feature_journal(sb));
4622 
4623 	if (journal_devnum &&
4624 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4625 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4626 			"numbers have changed");
4627 		journal_dev = new_decode_dev(journal_devnum);
4628 	} else
4629 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4630 
4631 	really_read_only = bdev_read_only(sb->s_bdev);
4632 
4633 	/*
4634 	 * Are we loading a blank journal or performing recovery after a
4635 	 * crash?  For recovery, we need to check in advance whether we
4636 	 * can get read-write access to the device.
4637 	 */
4638 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4639 		if (sb_rdonly(sb)) {
4640 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4641 					"required on readonly filesystem");
4642 			if (really_read_only) {
4643 				ext4_msg(sb, KERN_ERR, "write access "
4644 					"unavailable, cannot proceed "
4645 					"(try mounting with noload)");
4646 				return -EROFS;
4647 			}
4648 			ext4_msg(sb, KERN_INFO, "write access will "
4649 			       "be enabled during recovery");
4650 		}
4651 	}
4652 
4653 	if (journal_inum && journal_dev) {
4654 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4655 		       "and inode journals!");
4656 		return -EINVAL;
4657 	}
4658 
4659 	if (journal_inum) {
4660 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4661 			return -EINVAL;
4662 	} else {
4663 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4664 			return -EINVAL;
4665 	}
4666 
4667 	if (!(journal->j_flags & JBD2_BARRIER))
4668 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4669 
4670 	if (!ext4_has_feature_journal_needs_recovery(sb))
4671 		err = jbd2_journal_wipe(journal, !really_read_only);
4672 	if (!err) {
4673 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4674 		if (save)
4675 			memcpy(save, ((char *) es) +
4676 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4677 		err = jbd2_journal_load(journal);
4678 		if (save)
4679 			memcpy(((char *) es) + EXT4_S_ERR_START,
4680 			       save, EXT4_S_ERR_LEN);
4681 		kfree(save);
4682 	}
4683 
4684 	if (err) {
4685 		ext4_msg(sb, KERN_ERR, "error loading journal");
4686 		jbd2_journal_destroy(journal);
4687 		return err;
4688 	}
4689 
4690 	EXT4_SB(sb)->s_journal = journal;
4691 	ext4_clear_journal_err(sb, es);
4692 
4693 	if (!really_read_only && journal_devnum &&
4694 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4695 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4696 
4697 		/* Make sure we flush the recovery flag to disk. */
4698 		ext4_commit_super(sb, 1);
4699 	}
4700 
4701 	return 0;
4702 }
4703 
4704 static int ext4_commit_super(struct super_block *sb, int sync)
4705 {
4706 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4707 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4708 	int error = 0;
4709 
4710 	if (!sbh || block_device_ejected(sb))
4711 		return error;
4712 	/*
4713 	 * If the file system is mounted read-only, don't update the
4714 	 * superblock write time.  This avoids updating the superblock
4715 	 * write time when we are mounting the root file system
4716 	 * read/only but we need to replay the journal; at that point,
4717 	 * for people who are east of GMT and who make their clock
4718 	 * tick in localtime for Windows bug-for-bug compatibility,
4719 	 * the clock is set in the future, and this will cause e2fsck
4720 	 * to complain and force a full file system check.
4721 	 */
4722 	if (!(sb->s_flags & SB_RDONLY))
4723 		es->s_wtime = cpu_to_le32(get_seconds());
4724 	if (sb->s_bdev->bd_part)
4725 		es->s_kbytes_written =
4726 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4727 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4728 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4729 	else
4730 		es->s_kbytes_written =
4731 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4732 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4733 		ext4_free_blocks_count_set(es,
4734 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4735 				&EXT4_SB(sb)->s_freeclusters_counter)));
4736 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4737 		es->s_free_inodes_count =
4738 			cpu_to_le32(percpu_counter_sum_positive(
4739 				&EXT4_SB(sb)->s_freeinodes_counter));
4740 	BUFFER_TRACE(sbh, "marking dirty");
4741 	ext4_superblock_csum_set(sb);
4742 	if (sync)
4743 		lock_buffer(sbh);
4744 	if (buffer_write_io_error(sbh)) {
4745 		/*
4746 		 * Oh, dear.  A previous attempt to write the
4747 		 * superblock failed.  This could happen because the
4748 		 * USB device was yanked out.  Or it could happen to
4749 		 * be a transient write error and maybe the block will
4750 		 * be remapped.  Nothing we can do but to retry the
4751 		 * write and hope for the best.
4752 		 */
4753 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4754 		       "superblock detected");
4755 		clear_buffer_write_io_error(sbh);
4756 		set_buffer_uptodate(sbh);
4757 	}
4758 	mark_buffer_dirty(sbh);
4759 	if (sync) {
4760 		unlock_buffer(sbh);
4761 		error = __sync_dirty_buffer(sbh,
4762 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4763 		if (error)
4764 			return error;
4765 
4766 		error = buffer_write_io_error(sbh);
4767 		if (error) {
4768 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4769 			       "superblock");
4770 			clear_buffer_write_io_error(sbh);
4771 			set_buffer_uptodate(sbh);
4772 		}
4773 	}
4774 	return error;
4775 }
4776 
4777 /*
4778  * Have we just finished recovery?  If so, and if we are mounting (or
4779  * remounting) the filesystem readonly, then we will end up with a
4780  * consistent fs on disk.  Record that fact.
4781  */
4782 static void ext4_mark_recovery_complete(struct super_block *sb,
4783 					struct ext4_super_block *es)
4784 {
4785 	journal_t *journal = EXT4_SB(sb)->s_journal;
4786 
4787 	if (!ext4_has_feature_journal(sb)) {
4788 		BUG_ON(journal != NULL);
4789 		return;
4790 	}
4791 	jbd2_journal_lock_updates(journal);
4792 	if (jbd2_journal_flush(journal) < 0)
4793 		goto out;
4794 
4795 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
4796 		ext4_clear_feature_journal_needs_recovery(sb);
4797 		ext4_commit_super(sb, 1);
4798 	}
4799 
4800 out:
4801 	jbd2_journal_unlock_updates(journal);
4802 }
4803 
4804 /*
4805  * If we are mounting (or read-write remounting) a filesystem whose journal
4806  * has recorded an error from a previous lifetime, move that error to the
4807  * main filesystem now.
4808  */
4809 static void ext4_clear_journal_err(struct super_block *sb,
4810 				   struct ext4_super_block *es)
4811 {
4812 	journal_t *journal;
4813 	int j_errno;
4814 	const char *errstr;
4815 
4816 	BUG_ON(!ext4_has_feature_journal(sb));
4817 
4818 	journal = EXT4_SB(sb)->s_journal;
4819 
4820 	/*
4821 	 * Now check for any error status which may have been recorded in the
4822 	 * journal by a prior ext4_error() or ext4_abort()
4823 	 */
4824 
4825 	j_errno = jbd2_journal_errno(journal);
4826 	if (j_errno) {
4827 		char nbuf[16];
4828 
4829 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4830 		ext4_warning(sb, "Filesystem error recorded "
4831 			     "from previous mount: %s", errstr);
4832 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4833 
4834 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4835 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4836 		ext4_commit_super(sb, 1);
4837 
4838 		jbd2_journal_clear_err(journal);
4839 		jbd2_journal_update_sb_errno(journal);
4840 	}
4841 }
4842 
4843 /*
4844  * Force the running and committing transactions to commit,
4845  * and wait on the commit.
4846  */
4847 int ext4_force_commit(struct super_block *sb)
4848 {
4849 	journal_t *journal;
4850 
4851 	if (sb_rdonly(sb))
4852 		return 0;
4853 
4854 	journal = EXT4_SB(sb)->s_journal;
4855 	return ext4_journal_force_commit(journal);
4856 }
4857 
4858 static int ext4_sync_fs(struct super_block *sb, int wait)
4859 {
4860 	int ret = 0;
4861 	tid_t target;
4862 	bool needs_barrier = false;
4863 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4864 
4865 	if (unlikely(ext4_forced_shutdown(sbi)))
4866 		return 0;
4867 
4868 	trace_ext4_sync_fs(sb, wait);
4869 	flush_workqueue(sbi->rsv_conversion_wq);
4870 	/*
4871 	 * Writeback quota in non-journalled quota case - journalled quota has
4872 	 * no dirty dquots
4873 	 */
4874 	dquot_writeback_dquots(sb, -1);
4875 	/*
4876 	 * Data writeback is possible w/o journal transaction, so barrier must
4877 	 * being sent at the end of the function. But we can skip it if
4878 	 * transaction_commit will do it for us.
4879 	 */
4880 	if (sbi->s_journal) {
4881 		target = jbd2_get_latest_transaction(sbi->s_journal);
4882 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4883 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4884 			needs_barrier = true;
4885 
4886 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4887 			if (wait)
4888 				ret = jbd2_log_wait_commit(sbi->s_journal,
4889 							   target);
4890 		}
4891 	} else if (wait && test_opt(sb, BARRIER))
4892 		needs_barrier = true;
4893 	if (needs_barrier) {
4894 		int err;
4895 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4896 		if (!ret)
4897 			ret = err;
4898 	}
4899 
4900 	return ret;
4901 }
4902 
4903 /*
4904  * LVM calls this function before a (read-only) snapshot is created.  This
4905  * gives us a chance to flush the journal completely and mark the fs clean.
4906  *
4907  * Note that only this function cannot bring a filesystem to be in a clean
4908  * state independently. It relies on upper layer to stop all data & metadata
4909  * modifications.
4910  */
4911 static int ext4_freeze(struct super_block *sb)
4912 {
4913 	int error = 0;
4914 	journal_t *journal;
4915 
4916 	if (sb_rdonly(sb))
4917 		return 0;
4918 
4919 	journal = EXT4_SB(sb)->s_journal;
4920 
4921 	if (journal) {
4922 		/* Now we set up the journal barrier. */
4923 		jbd2_journal_lock_updates(journal);
4924 
4925 		/*
4926 		 * Don't clear the needs_recovery flag if we failed to
4927 		 * flush the journal.
4928 		 */
4929 		error = jbd2_journal_flush(journal);
4930 		if (error < 0)
4931 			goto out;
4932 
4933 		/* Journal blocked and flushed, clear needs_recovery flag. */
4934 		ext4_clear_feature_journal_needs_recovery(sb);
4935 	}
4936 
4937 	error = ext4_commit_super(sb, 1);
4938 out:
4939 	if (journal)
4940 		/* we rely on upper layer to stop further updates */
4941 		jbd2_journal_unlock_updates(journal);
4942 	return error;
4943 }
4944 
4945 /*
4946  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4947  * flag here, even though the filesystem is not technically dirty yet.
4948  */
4949 static int ext4_unfreeze(struct super_block *sb)
4950 {
4951 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
4952 		return 0;
4953 
4954 	if (EXT4_SB(sb)->s_journal) {
4955 		/* Reset the needs_recovery flag before the fs is unlocked. */
4956 		ext4_set_feature_journal_needs_recovery(sb);
4957 	}
4958 
4959 	ext4_commit_super(sb, 1);
4960 	return 0;
4961 }
4962 
4963 /*
4964  * Structure to save mount options for ext4_remount's benefit
4965  */
4966 struct ext4_mount_options {
4967 	unsigned long s_mount_opt;
4968 	unsigned long s_mount_opt2;
4969 	kuid_t s_resuid;
4970 	kgid_t s_resgid;
4971 	unsigned long s_commit_interval;
4972 	u32 s_min_batch_time, s_max_batch_time;
4973 #ifdef CONFIG_QUOTA
4974 	int s_jquota_fmt;
4975 	char *s_qf_names[EXT4_MAXQUOTAS];
4976 #endif
4977 };
4978 
4979 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4980 {
4981 	struct ext4_super_block *es;
4982 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4983 	unsigned long old_sb_flags;
4984 	struct ext4_mount_options old_opts;
4985 	int enable_quota = 0;
4986 	ext4_group_t g;
4987 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4988 	int err = 0;
4989 #ifdef CONFIG_QUOTA
4990 	int i, j;
4991 #endif
4992 	char *orig_data = kstrdup(data, GFP_KERNEL);
4993 
4994 	/* Store the original options */
4995 	old_sb_flags = sb->s_flags;
4996 	old_opts.s_mount_opt = sbi->s_mount_opt;
4997 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4998 	old_opts.s_resuid = sbi->s_resuid;
4999 	old_opts.s_resgid = sbi->s_resgid;
5000 	old_opts.s_commit_interval = sbi->s_commit_interval;
5001 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5002 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5003 #ifdef CONFIG_QUOTA
5004 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5005 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5006 		if (sbi->s_qf_names[i]) {
5007 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
5008 							 GFP_KERNEL);
5009 			if (!old_opts.s_qf_names[i]) {
5010 				for (j = 0; j < i; j++)
5011 					kfree(old_opts.s_qf_names[j]);
5012 				kfree(orig_data);
5013 				return -ENOMEM;
5014 			}
5015 		} else
5016 			old_opts.s_qf_names[i] = NULL;
5017 #endif
5018 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5019 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5020 
5021 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5022 		err = -EINVAL;
5023 		goto restore_opts;
5024 	}
5025 
5026 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5027 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5028 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5029 			 "during remount not supported; ignoring");
5030 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5031 	}
5032 
5033 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5034 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5035 			ext4_msg(sb, KERN_ERR, "can't mount with "
5036 				 "both data=journal and delalloc");
5037 			err = -EINVAL;
5038 			goto restore_opts;
5039 		}
5040 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5041 			ext4_msg(sb, KERN_ERR, "can't mount with "
5042 				 "both data=journal and dioread_nolock");
5043 			err = -EINVAL;
5044 			goto restore_opts;
5045 		}
5046 		if (test_opt(sb, DAX)) {
5047 			ext4_msg(sb, KERN_ERR, "can't mount with "
5048 				 "both data=journal and dax");
5049 			err = -EINVAL;
5050 			goto restore_opts;
5051 		}
5052 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5053 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5054 			ext4_msg(sb, KERN_ERR, "can't mount with "
5055 				"journal_async_commit in data=ordered mode");
5056 			err = -EINVAL;
5057 			goto restore_opts;
5058 		}
5059 	}
5060 
5061 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5062 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5063 		err = -EINVAL;
5064 		goto restore_opts;
5065 	}
5066 
5067 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5068 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5069 			"dax flag with busy inodes while remounting");
5070 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5071 	}
5072 
5073 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5074 		ext4_abort(sb, "Abort forced by user");
5075 
5076 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5077 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5078 
5079 	es = sbi->s_es;
5080 
5081 	if (sbi->s_journal) {
5082 		ext4_init_journal_params(sb, sbi->s_journal);
5083 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5084 	}
5085 
5086 	if (*flags & SB_LAZYTIME)
5087 		sb->s_flags |= SB_LAZYTIME;
5088 
5089 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5090 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5091 			err = -EROFS;
5092 			goto restore_opts;
5093 		}
5094 
5095 		if (*flags & SB_RDONLY) {
5096 			err = sync_filesystem(sb);
5097 			if (err < 0)
5098 				goto restore_opts;
5099 			err = dquot_suspend(sb, -1);
5100 			if (err < 0)
5101 				goto restore_opts;
5102 
5103 			/*
5104 			 * First of all, the unconditional stuff we have to do
5105 			 * to disable replay of the journal when we next remount
5106 			 */
5107 			sb->s_flags |= SB_RDONLY;
5108 
5109 			/*
5110 			 * OK, test if we are remounting a valid rw partition
5111 			 * readonly, and if so set the rdonly flag and then
5112 			 * mark the partition as valid again.
5113 			 */
5114 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5115 			    (sbi->s_mount_state & EXT4_VALID_FS))
5116 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5117 
5118 			if (sbi->s_journal)
5119 				ext4_mark_recovery_complete(sb, es);
5120 		} else {
5121 			/* Make sure we can mount this feature set readwrite */
5122 			if (ext4_has_feature_readonly(sb) ||
5123 			    !ext4_feature_set_ok(sb, 0)) {
5124 				err = -EROFS;
5125 				goto restore_opts;
5126 			}
5127 			/*
5128 			 * Make sure the group descriptor checksums
5129 			 * are sane.  If they aren't, refuse to remount r/w.
5130 			 */
5131 			for (g = 0; g < sbi->s_groups_count; g++) {
5132 				struct ext4_group_desc *gdp =
5133 					ext4_get_group_desc(sb, g, NULL);
5134 
5135 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5136 					ext4_msg(sb, KERN_ERR,
5137 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5138 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5139 					       le16_to_cpu(gdp->bg_checksum));
5140 					err = -EFSBADCRC;
5141 					goto restore_opts;
5142 				}
5143 			}
5144 
5145 			/*
5146 			 * If we have an unprocessed orphan list hanging
5147 			 * around from a previously readonly bdev mount,
5148 			 * require a full umount/remount for now.
5149 			 */
5150 			if (es->s_last_orphan) {
5151 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5152 				       "remount RDWR because of unprocessed "
5153 				       "orphan inode list.  Please "
5154 				       "umount/remount instead");
5155 				err = -EINVAL;
5156 				goto restore_opts;
5157 			}
5158 
5159 			/*
5160 			 * Mounting a RDONLY partition read-write, so reread
5161 			 * and store the current valid flag.  (It may have
5162 			 * been changed by e2fsck since we originally mounted
5163 			 * the partition.)
5164 			 */
5165 			if (sbi->s_journal)
5166 				ext4_clear_journal_err(sb, es);
5167 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5168 			if (!ext4_setup_super(sb, es, 0))
5169 				sb->s_flags &= ~SB_RDONLY;
5170 			if (ext4_has_feature_mmp(sb))
5171 				if (ext4_multi_mount_protect(sb,
5172 						le64_to_cpu(es->s_mmp_block))) {
5173 					err = -EROFS;
5174 					goto restore_opts;
5175 				}
5176 			enable_quota = 1;
5177 		}
5178 	}
5179 
5180 	/*
5181 	 * Reinitialize lazy itable initialization thread based on
5182 	 * current settings
5183 	 */
5184 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5185 		ext4_unregister_li_request(sb);
5186 	else {
5187 		ext4_group_t first_not_zeroed;
5188 		first_not_zeroed = ext4_has_uninit_itable(sb);
5189 		ext4_register_li_request(sb, first_not_zeroed);
5190 	}
5191 
5192 	ext4_setup_system_zone(sb);
5193 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY))
5194 		ext4_commit_super(sb, 1);
5195 
5196 #ifdef CONFIG_QUOTA
5197 	/* Release old quota file names */
5198 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5199 		kfree(old_opts.s_qf_names[i]);
5200 	if (enable_quota) {
5201 		if (sb_any_quota_suspended(sb))
5202 			dquot_resume(sb, -1);
5203 		else if (ext4_has_feature_quota(sb)) {
5204 			err = ext4_enable_quotas(sb);
5205 			if (err)
5206 				goto restore_opts;
5207 		}
5208 	}
5209 #endif
5210 
5211 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5212 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5213 	kfree(orig_data);
5214 	return 0;
5215 
5216 restore_opts:
5217 	sb->s_flags = old_sb_flags;
5218 	sbi->s_mount_opt = old_opts.s_mount_opt;
5219 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5220 	sbi->s_resuid = old_opts.s_resuid;
5221 	sbi->s_resgid = old_opts.s_resgid;
5222 	sbi->s_commit_interval = old_opts.s_commit_interval;
5223 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5224 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5225 #ifdef CONFIG_QUOTA
5226 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5227 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5228 		kfree(sbi->s_qf_names[i]);
5229 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5230 	}
5231 #endif
5232 	kfree(orig_data);
5233 	return err;
5234 }
5235 
5236 #ifdef CONFIG_QUOTA
5237 static int ext4_statfs_project(struct super_block *sb,
5238 			       kprojid_t projid, struct kstatfs *buf)
5239 {
5240 	struct kqid qid;
5241 	struct dquot *dquot;
5242 	u64 limit;
5243 	u64 curblock;
5244 
5245 	qid = make_kqid_projid(projid);
5246 	dquot = dqget(sb, qid);
5247 	if (IS_ERR(dquot))
5248 		return PTR_ERR(dquot);
5249 	spin_lock(&dquot->dq_dqb_lock);
5250 
5251 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5252 		 dquot->dq_dqb.dqb_bsoftlimit :
5253 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5254 	if (limit && buf->f_blocks > limit) {
5255 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5256 		buf->f_blocks = limit;
5257 		buf->f_bfree = buf->f_bavail =
5258 			(buf->f_blocks > curblock) ?
5259 			 (buf->f_blocks - curblock) : 0;
5260 	}
5261 
5262 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5263 		dquot->dq_dqb.dqb_isoftlimit :
5264 		dquot->dq_dqb.dqb_ihardlimit;
5265 	if (limit && buf->f_files > limit) {
5266 		buf->f_files = limit;
5267 		buf->f_ffree =
5268 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5269 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5270 	}
5271 
5272 	spin_unlock(&dquot->dq_dqb_lock);
5273 	dqput(dquot);
5274 	return 0;
5275 }
5276 #endif
5277 
5278 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5279 {
5280 	struct super_block *sb = dentry->d_sb;
5281 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5282 	struct ext4_super_block *es = sbi->s_es;
5283 	ext4_fsblk_t overhead = 0, resv_blocks;
5284 	u64 fsid;
5285 	s64 bfree;
5286 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5287 
5288 	if (!test_opt(sb, MINIX_DF))
5289 		overhead = sbi->s_overhead;
5290 
5291 	buf->f_type = EXT4_SUPER_MAGIC;
5292 	buf->f_bsize = sb->s_blocksize;
5293 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5294 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5295 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5296 	/* prevent underflow in case that few free space is available */
5297 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5298 	buf->f_bavail = buf->f_bfree -
5299 			(ext4_r_blocks_count(es) + resv_blocks);
5300 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5301 		buf->f_bavail = 0;
5302 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5303 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5304 	buf->f_namelen = EXT4_NAME_LEN;
5305 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5306 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5307 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5308 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5309 
5310 #ifdef CONFIG_QUOTA
5311 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5312 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5313 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5314 #endif
5315 	return 0;
5316 }
5317 
5318 
5319 #ifdef CONFIG_QUOTA
5320 
5321 /*
5322  * Helper functions so that transaction is started before we acquire dqio_sem
5323  * to keep correct lock ordering of transaction > dqio_sem
5324  */
5325 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5326 {
5327 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5328 }
5329 
5330 static int ext4_write_dquot(struct dquot *dquot)
5331 {
5332 	int ret, err;
5333 	handle_t *handle;
5334 	struct inode *inode;
5335 
5336 	inode = dquot_to_inode(dquot);
5337 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5338 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5339 	if (IS_ERR(handle))
5340 		return PTR_ERR(handle);
5341 	ret = dquot_commit(dquot);
5342 	err = ext4_journal_stop(handle);
5343 	if (!ret)
5344 		ret = err;
5345 	return ret;
5346 }
5347 
5348 static int ext4_acquire_dquot(struct dquot *dquot)
5349 {
5350 	int ret, err;
5351 	handle_t *handle;
5352 
5353 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5354 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5355 	if (IS_ERR(handle))
5356 		return PTR_ERR(handle);
5357 	ret = dquot_acquire(dquot);
5358 	err = ext4_journal_stop(handle);
5359 	if (!ret)
5360 		ret = err;
5361 	return ret;
5362 }
5363 
5364 static int ext4_release_dquot(struct dquot *dquot)
5365 {
5366 	int ret, err;
5367 	handle_t *handle;
5368 
5369 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5370 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5371 	if (IS_ERR(handle)) {
5372 		/* Release dquot anyway to avoid endless cycle in dqput() */
5373 		dquot_release(dquot);
5374 		return PTR_ERR(handle);
5375 	}
5376 	ret = dquot_release(dquot);
5377 	err = ext4_journal_stop(handle);
5378 	if (!ret)
5379 		ret = err;
5380 	return ret;
5381 }
5382 
5383 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5384 {
5385 	struct super_block *sb = dquot->dq_sb;
5386 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5387 
5388 	/* Are we journaling quotas? */
5389 	if (ext4_has_feature_quota(sb) ||
5390 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5391 		dquot_mark_dquot_dirty(dquot);
5392 		return ext4_write_dquot(dquot);
5393 	} else {
5394 		return dquot_mark_dquot_dirty(dquot);
5395 	}
5396 }
5397 
5398 static int ext4_write_info(struct super_block *sb, int type)
5399 {
5400 	int ret, err;
5401 	handle_t *handle;
5402 
5403 	/* Data block + inode block */
5404 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5405 	if (IS_ERR(handle))
5406 		return PTR_ERR(handle);
5407 	ret = dquot_commit_info(sb, type);
5408 	err = ext4_journal_stop(handle);
5409 	if (!ret)
5410 		ret = err;
5411 	return ret;
5412 }
5413 
5414 /*
5415  * Turn on quotas during mount time - we need to find
5416  * the quota file and such...
5417  */
5418 static int ext4_quota_on_mount(struct super_block *sb, int type)
5419 {
5420 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5421 					EXT4_SB(sb)->s_jquota_fmt, type);
5422 }
5423 
5424 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5425 {
5426 	struct ext4_inode_info *ei = EXT4_I(inode);
5427 
5428 	/* The first argument of lockdep_set_subclass has to be
5429 	 * *exactly* the same as the argument to init_rwsem() --- in
5430 	 * this case, in init_once() --- or lockdep gets unhappy
5431 	 * because the name of the lock is set using the
5432 	 * stringification of the argument to init_rwsem().
5433 	 */
5434 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5435 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5436 }
5437 
5438 /*
5439  * Standard function to be called on quota_on
5440  */
5441 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5442 			 const struct path *path)
5443 {
5444 	int err;
5445 
5446 	if (!test_opt(sb, QUOTA))
5447 		return -EINVAL;
5448 
5449 	/* Quotafile not on the same filesystem? */
5450 	if (path->dentry->d_sb != sb)
5451 		return -EXDEV;
5452 	/* Journaling quota? */
5453 	if (EXT4_SB(sb)->s_qf_names[type]) {
5454 		/* Quotafile not in fs root? */
5455 		if (path->dentry->d_parent != sb->s_root)
5456 			ext4_msg(sb, KERN_WARNING,
5457 				"Quota file not on filesystem root. "
5458 				"Journaled quota will not work");
5459 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5460 	} else {
5461 		/*
5462 		 * Clear the flag just in case mount options changed since
5463 		 * last time.
5464 		 */
5465 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5466 	}
5467 
5468 	/*
5469 	 * When we journal data on quota file, we have to flush journal to see
5470 	 * all updates to the file when we bypass pagecache...
5471 	 */
5472 	if (EXT4_SB(sb)->s_journal &&
5473 	    ext4_should_journal_data(d_inode(path->dentry))) {
5474 		/*
5475 		 * We don't need to lock updates but journal_flush() could
5476 		 * otherwise be livelocked...
5477 		 */
5478 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5479 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5480 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5481 		if (err)
5482 			return err;
5483 	}
5484 
5485 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5486 	err = dquot_quota_on(sb, type, format_id, path);
5487 	if (err) {
5488 		lockdep_set_quota_inode(path->dentry->d_inode,
5489 					     I_DATA_SEM_NORMAL);
5490 	} else {
5491 		struct inode *inode = d_inode(path->dentry);
5492 		handle_t *handle;
5493 
5494 		/*
5495 		 * Set inode flags to prevent userspace from messing with quota
5496 		 * files. If this fails, we return success anyway since quotas
5497 		 * are already enabled and this is not a hard failure.
5498 		 */
5499 		inode_lock(inode);
5500 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5501 		if (IS_ERR(handle))
5502 			goto unlock_inode;
5503 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5504 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5505 				S_NOATIME | S_IMMUTABLE);
5506 		ext4_mark_inode_dirty(handle, inode);
5507 		ext4_journal_stop(handle);
5508 	unlock_inode:
5509 		inode_unlock(inode);
5510 	}
5511 	return err;
5512 }
5513 
5514 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5515 			     unsigned int flags)
5516 {
5517 	int err;
5518 	struct inode *qf_inode;
5519 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5520 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5521 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5522 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5523 	};
5524 
5525 	BUG_ON(!ext4_has_feature_quota(sb));
5526 
5527 	if (!qf_inums[type])
5528 		return -EPERM;
5529 
5530 	qf_inode = ext4_iget(sb, qf_inums[type]);
5531 	if (IS_ERR(qf_inode)) {
5532 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5533 		return PTR_ERR(qf_inode);
5534 	}
5535 
5536 	/* Don't account quota for quota files to avoid recursion */
5537 	qf_inode->i_flags |= S_NOQUOTA;
5538 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5539 	err = dquot_enable(qf_inode, type, format_id, flags);
5540 	iput(qf_inode);
5541 	if (err)
5542 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5543 
5544 	return err;
5545 }
5546 
5547 /* Enable usage tracking for all quota types. */
5548 static int ext4_enable_quotas(struct super_block *sb)
5549 {
5550 	int type, err = 0;
5551 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5552 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5553 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5554 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5555 	};
5556 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5557 		test_opt(sb, USRQUOTA),
5558 		test_opt(sb, GRPQUOTA),
5559 		test_opt(sb, PRJQUOTA),
5560 	};
5561 
5562 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5563 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5564 		if (qf_inums[type]) {
5565 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5566 				DQUOT_USAGE_ENABLED |
5567 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5568 			if (err) {
5569 				for (type--; type >= 0; type--)
5570 					dquot_quota_off(sb, type);
5571 
5572 				ext4_warning(sb,
5573 					"Failed to enable quota tracking "
5574 					"(type=%d, err=%d). Please run "
5575 					"e2fsck to fix.", type, err);
5576 				return err;
5577 			}
5578 		}
5579 	}
5580 	return 0;
5581 }
5582 
5583 static int ext4_quota_off(struct super_block *sb, int type)
5584 {
5585 	struct inode *inode = sb_dqopt(sb)->files[type];
5586 	handle_t *handle;
5587 	int err;
5588 
5589 	/* Force all delayed allocation blocks to be allocated.
5590 	 * Caller already holds s_umount sem */
5591 	if (test_opt(sb, DELALLOC))
5592 		sync_filesystem(sb);
5593 
5594 	if (!inode || !igrab(inode))
5595 		goto out;
5596 
5597 	err = dquot_quota_off(sb, type);
5598 	if (err || ext4_has_feature_quota(sb))
5599 		goto out_put;
5600 
5601 	inode_lock(inode);
5602 	/*
5603 	 * Update modification times of quota files when userspace can
5604 	 * start looking at them. If we fail, we return success anyway since
5605 	 * this is not a hard failure and quotas are already disabled.
5606 	 */
5607 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5608 	if (IS_ERR(handle))
5609 		goto out_unlock;
5610 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5611 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5612 	inode->i_mtime = inode->i_ctime = current_time(inode);
5613 	ext4_mark_inode_dirty(handle, inode);
5614 	ext4_journal_stop(handle);
5615 out_unlock:
5616 	inode_unlock(inode);
5617 out_put:
5618 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5619 	iput(inode);
5620 	return err;
5621 out:
5622 	return dquot_quota_off(sb, type);
5623 }
5624 
5625 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5626  * acquiring the locks... As quota files are never truncated and quota code
5627  * itself serializes the operations (and no one else should touch the files)
5628  * we don't have to be afraid of races */
5629 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5630 			       size_t len, loff_t off)
5631 {
5632 	struct inode *inode = sb_dqopt(sb)->files[type];
5633 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5634 	int offset = off & (sb->s_blocksize - 1);
5635 	int tocopy;
5636 	size_t toread;
5637 	struct buffer_head *bh;
5638 	loff_t i_size = i_size_read(inode);
5639 
5640 	if (off > i_size)
5641 		return 0;
5642 	if (off+len > i_size)
5643 		len = i_size-off;
5644 	toread = len;
5645 	while (toread > 0) {
5646 		tocopy = sb->s_blocksize - offset < toread ?
5647 				sb->s_blocksize - offset : toread;
5648 		bh = ext4_bread(NULL, inode, blk, 0);
5649 		if (IS_ERR(bh))
5650 			return PTR_ERR(bh);
5651 		if (!bh)	/* A hole? */
5652 			memset(data, 0, tocopy);
5653 		else
5654 			memcpy(data, bh->b_data+offset, tocopy);
5655 		brelse(bh);
5656 		offset = 0;
5657 		toread -= tocopy;
5658 		data += tocopy;
5659 		blk++;
5660 	}
5661 	return len;
5662 }
5663 
5664 /* Write to quotafile (we know the transaction is already started and has
5665  * enough credits) */
5666 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5667 				const char *data, size_t len, loff_t off)
5668 {
5669 	struct inode *inode = sb_dqopt(sb)->files[type];
5670 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5671 	int err, offset = off & (sb->s_blocksize - 1);
5672 	int retries = 0;
5673 	struct buffer_head *bh;
5674 	handle_t *handle = journal_current_handle();
5675 
5676 	if (EXT4_SB(sb)->s_journal && !handle) {
5677 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5678 			" cancelled because transaction is not started",
5679 			(unsigned long long)off, (unsigned long long)len);
5680 		return -EIO;
5681 	}
5682 	/*
5683 	 * Since we account only one data block in transaction credits,
5684 	 * then it is impossible to cross a block boundary.
5685 	 */
5686 	if (sb->s_blocksize - offset < len) {
5687 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5688 			" cancelled because not block aligned",
5689 			(unsigned long long)off, (unsigned long long)len);
5690 		return -EIO;
5691 	}
5692 
5693 	do {
5694 		bh = ext4_bread(handle, inode, blk,
5695 				EXT4_GET_BLOCKS_CREATE |
5696 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5697 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5698 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5699 	if (IS_ERR(bh))
5700 		return PTR_ERR(bh);
5701 	if (!bh)
5702 		goto out;
5703 	BUFFER_TRACE(bh, "get write access");
5704 	err = ext4_journal_get_write_access(handle, bh);
5705 	if (err) {
5706 		brelse(bh);
5707 		return err;
5708 	}
5709 	lock_buffer(bh);
5710 	memcpy(bh->b_data+offset, data, len);
5711 	flush_dcache_page(bh->b_page);
5712 	unlock_buffer(bh);
5713 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5714 	brelse(bh);
5715 out:
5716 	if (inode->i_size < off + len) {
5717 		i_size_write(inode, off + len);
5718 		EXT4_I(inode)->i_disksize = inode->i_size;
5719 		ext4_mark_inode_dirty(handle, inode);
5720 	}
5721 	return len;
5722 }
5723 
5724 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5725 {
5726 	const struct quota_format_ops	*ops;
5727 
5728 	if (!sb_has_quota_loaded(sb, qid->type))
5729 		return -ESRCH;
5730 	ops = sb_dqopt(sb)->ops[qid->type];
5731 	if (!ops || !ops->get_next_id)
5732 		return -ENOSYS;
5733 	return dquot_get_next_id(sb, qid);
5734 }
5735 #endif
5736 
5737 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5738 		       const char *dev_name, void *data)
5739 {
5740 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5741 }
5742 
5743 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5744 static inline void register_as_ext2(void)
5745 {
5746 	int err = register_filesystem(&ext2_fs_type);
5747 	if (err)
5748 		printk(KERN_WARNING
5749 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5750 }
5751 
5752 static inline void unregister_as_ext2(void)
5753 {
5754 	unregister_filesystem(&ext2_fs_type);
5755 }
5756 
5757 static inline int ext2_feature_set_ok(struct super_block *sb)
5758 {
5759 	if (ext4_has_unknown_ext2_incompat_features(sb))
5760 		return 0;
5761 	if (sb_rdonly(sb))
5762 		return 1;
5763 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5764 		return 0;
5765 	return 1;
5766 }
5767 #else
5768 static inline void register_as_ext2(void) { }
5769 static inline void unregister_as_ext2(void) { }
5770 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5771 #endif
5772 
5773 static inline void register_as_ext3(void)
5774 {
5775 	int err = register_filesystem(&ext3_fs_type);
5776 	if (err)
5777 		printk(KERN_WARNING
5778 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5779 }
5780 
5781 static inline void unregister_as_ext3(void)
5782 {
5783 	unregister_filesystem(&ext3_fs_type);
5784 }
5785 
5786 static inline int ext3_feature_set_ok(struct super_block *sb)
5787 {
5788 	if (ext4_has_unknown_ext3_incompat_features(sb))
5789 		return 0;
5790 	if (!ext4_has_feature_journal(sb))
5791 		return 0;
5792 	if (sb_rdonly(sb))
5793 		return 1;
5794 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5795 		return 0;
5796 	return 1;
5797 }
5798 
5799 static struct file_system_type ext4_fs_type = {
5800 	.owner		= THIS_MODULE,
5801 	.name		= "ext4",
5802 	.mount		= ext4_mount,
5803 	.kill_sb	= kill_block_super,
5804 	.fs_flags	= FS_REQUIRES_DEV,
5805 };
5806 MODULE_ALIAS_FS("ext4");
5807 
5808 /* Shared across all ext4 file systems */
5809 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5810 
5811 static int __init ext4_init_fs(void)
5812 {
5813 	int i, err;
5814 
5815 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5816 	ext4_li_info = NULL;
5817 	mutex_init(&ext4_li_mtx);
5818 
5819 	/* Build-time check for flags consistency */
5820 	ext4_check_flag_values();
5821 
5822 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5823 		init_waitqueue_head(&ext4__ioend_wq[i]);
5824 
5825 	err = ext4_init_es();
5826 	if (err)
5827 		return err;
5828 
5829 	err = ext4_init_pageio();
5830 	if (err)
5831 		goto out5;
5832 
5833 	err = ext4_init_system_zone();
5834 	if (err)
5835 		goto out4;
5836 
5837 	err = ext4_init_sysfs();
5838 	if (err)
5839 		goto out3;
5840 
5841 	err = ext4_init_mballoc();
5842 	if (err)
5843 		goto out2;
5844 	err = init_inodecache();
5845 	if (err)
5846 		goto out1;
5847 	register_as_ext3();
5848 	register_as_ext2();
5849 	err = register_filesystem(&ext4_fs_type);
5850 	if (err)
5851 		goto out;
5852 
5853 	return 0;
5854 out:
5855 	unregister_as_ext2();
5856 	unregister_as_ext3();
5857 	destroy_inodecache();
5858 out1:
5859 	ext4_exit_mballoc();
5860 out2:
5861 	ext4_exit_sysfs();
5862 out3:
5863 	ext4_exit_system_zone();
5864 out4:
5865 	ext4_exit_pageio();
5866 out5:
5867 	ext4_exit_es();
5868 
5869 	return err;
5870 }
5871 
5872 static void __exit ext4_exit_fs(void)
5873 {
5874 	ext4_destroy_lazyinit_thread();
5875 	unregister_as_ext2();
5876 	unregister_as_ext3();
5877 	unregister_filesystem(&ext4_fs_type);
5878 	destroy_inodecache();
5879 	ext4_exit_mballoc();
5880 	ext4_exit_sysfs();
5881 	ext4_exit_system_zone();
5882 	ext4_exit_pageio();
5883 	ext4_exit_es();
5884 }
5885 
5886 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5887 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5888 MODULE_LICENSE("GPL");
5889 module_init(ext4_init_fs)
5890 module_exit(ext4_exit_fs)
5891