xref: /openbmc/linux/fs/ext4/super.c (revision 68198dca)
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/vmalloc.h>
24 #include <linux/slab.h>
25 #include <linux/init.h>
26 #include <linux/blkdev.h>
27 #include <linux/backing-dev.h>
28 #include <linux/parser.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/ctype.h>
38 #include <linux/log2.h>
39 #include <linux/crc16.h>
40 #include <linux/dax.h>
41 #include <linux/cleancache.h>
42 #include <linux/uaccess.h>
43 
44 #include <linux/kthread.h>
45 #include <linux/freezer.h>
46 
47 #include "ext4.h"
48 #include "ext4_extents.h"	/* Needed for trace points definition */
49 #include "ext4_jbd2.h"
50 #include "xattr.h"
51 #include "acl.h"
52 #include "mballoc.h"
53 #include "fsmap.h"
54 
55 #define CREATE_TRACE_POINTS
56 #include <trace/events/ext4.h>
57 
58 static struct ext4_lazy_init *ext4_li_info;
59 static struct mutex ext4_li_mtx;
60 static struct ratelimit_state ext4_mount_msg_ratelimit;
61 
62 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
63 			     unsigned long journal_devnum);
64 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
65 static int ext4_commit_super(struct super_block *sb, int sync);
66 static void ext4_mark_recovery_complete(struct super_block *sb,
67 					struct ext4_super_block *es);
68 static void ext4_clear_journal_err(struct super_block *sb,
69 				   struct ext4_super_block *es);
70 static int ext4_sync_fs(struct super_block *sb, int wait);
71 static int ext4_remount(struct super_block *sb, int *flags, char *data);
72 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
73 static int ext4_unfreeze(struct super_block *sb);
74 static int ext4_freeze(struct super_block *sb);
75 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
76 		       const char *dev_name, void *data);
77 static inline int ext2_feature_set_ok(struct super_block *sb);
78 static inline int ext3_feature_set_ok(struct super_block *sb);
79 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
80 static void ext4_destroy_lazyinit_thread(void);
81 static void ext4_unregister_li_request(struct super_block *sb);
82 static void ext4_clear_request_list(void);
83 static struct inode *ext4_get_journal_inode(struct super_block *sb,
84 					    unsigned int journal_inum);
85 
86 /*
87  * Lock ordering
88  *
89  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
90  * i_mmap_rwsem (inode->i_mmap_rwsem)!
91  *
92  * page fault path:
93  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
94  *   page lock -> i_data_sem (rw)
95  *
96  * buffered write path:
97  * sb_start_write -> i_mutex -> mmap_sem
98  * sb_start_write -> i_mutex -> transaction start -> page lock ->
99  *   i_data_sem (rw)
100  *
101  * truncate:
102  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
103  *   i_mmap_rwsem (w) -> page lock
104  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
105  *   transaction start -> i_data_sem (rw)
106  *
107  * direct IO:
108  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
109  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
110  *   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 	if (ext4_error_ratelimit(sb)) {
450 		va_start(args, fmt);
451 		vaf.fmt = fmt;
452 		vaf.va = &args;
453 		printk(KERN_CRIT
454 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
455 		       sb->s_id, function, line, current->comm, &vaf);
456 		va_end(args);
457 	}
458 	save_error_info(sb, function, line);
459 	ext4_handle_error(sb);
460 }
461 
462 void __ext4_error_inode(struct inode *inode, const char *function,
463 			unsigned int line, ext4_fsblk_t block,
464 			const char *fmt, ...)
465 {
466 	va_list args;
467 	struct va_format vaf;
468 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
469 
470 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
471 		return;
472 
473 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
474 	es->s_last_error_block = cpu_to_le64(block);
475 	if (ext4_error_ratelimit(inode->i_sb)) {
476 		va_start(args, fmt);
477 		vaf.fmt = fmt;
478 		vaf.va = &args;
479 		if (block)
480 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
481 			       "inode #%lu: block %llu: comm %s: %pV\n",
482 			       inode->i_sb->s_id, function, line, inode->i_ino,
483 			       block, current->comm, &vaf);
484 		else
485 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
486 			       "inode #%lu: comm %s: %pV\n",
487 			       inode->i_sb->s_id, function, line, inode->i_ino,
488 			       current->comm, &vaf);
489 		va_end(args);
490 	}
491 	save_error_info(inode->i_sb, function, line);
492 	ext4_handle_error(inode->i_sb);
493 }
494 
495 void __ext4_error_file(struct file *file, const char *function,
496 		       unsigned int line, ext4_fsblk_t block,
497 		       const char *fmt, ...)
498 {
499 	va_list args;
500 	struct va_format vaf;
501 	struct ext4_super_block *es;
502 	struct inode *inode = file_inode(file);
503 	char pathname[80], *path;
504 
505 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
506 		return;
507 
508 	es = EXT4_SB(inode->i_sb)->s_es;
509 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
510 	if (ext4_error_ratelimit(inode->i_sb)) {
511 		path = file_path(file, pathname, sizeof(pathname));
512 		if (IS_ERR(path))
513 			path = "(unknown)";
514 		va_start(args, fmt);
515 		vaf.fmt = fmt;
516 		vaf.va = &args;
517 		if (block)
518 			printk(KERN_CRIT
519 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
520 			       "block %llu: comm %s: path %s: %pV\n",
521 			       inode->i_sb->s_id, function, line, inode->i_ino,
522 			       block, current->comm, path, &vaf);
523 		else
524 			printk(KERN_CRIT
525 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
526 			       "comm %s: path %s: %pV\n",
527 			       inode->i_sb->s_id, function, line, inode->i_ino,
528 			       current->comm, path, &vaf);
529 		va_end(args);
530 	}
531 	save_error_info(inode->i_sb, function, line);
532 	ext4_handle_error(inode->i_sb);
533 }
534 
535 const char *ext4_decode_error(struct super_block *sb, int errno,
536 			      char nbuf[16])
537 {
538 	char *errstr = NULL;
539 
540 	switch (errno) {
541 	case -EFSCORRUPTED:
542 		errstr = "Corrupt filesystem";
543 		break;
544 	case -EFSBADCRC:
545 		errstr = "Filesystem failed CRC";
546 		break;
547 	case -EIO:
548 		errstr = "IO failure";
549 		break;
550 	case -ENOMEM:
551 		errstr = "Out of memory";
552 		break;
553 	case -EROFS:
554 		if (!sb || (EXT4_SB(sb)->s_journal &&
555 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
556 			errstr = "Journal has aborted";
557 		else
558 			errstr = "Readonly filesystem";
559 		break;
560 	default:
561 		/* If the caller passed in an extra buffer for unknown
562 		 * errors, textualise them now.  Else we just return
563 		 * NULL. */
564 		if (nbuf) {
565 			/* Check for truncated error codes... */
566 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
567 				errstr = nbuf;
568 		}
569 		break;
570 	}
571 
572 	return errstr;
573 }
574 
575 /* __ext4_std_error decodes expected errors from journaling functions
576  * automatically and invokes the appropriate error response.  */
577 
578 void __ext4_std_error(struct super_block *sb, const char *function,
579 		      unsigned int line, int errno)
580 {
581 	char nbuf[16];
582 	const char *errstr;
583 
584 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
585 		return;
586 
587 	/* Special case: if the error is EROFS, and we're not already
588 	 * inside a transaction, then there's really no point in logging
589 	 * an error. */
590 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
591 		return;
592 
593 	if (ext4_error_ratelimit(sb)) {
594 		errstr = ext4_decode_error(sb, errno, nbuf);
595 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
596 		       sb->s_id, function, line, errstr);
597 	}
598 
599 	save_error_info(sb, function, line);
600 	ext4_handle_error(sb);
601 }
602 
603 /*
604  * ext4_abort is a much stronger failure handler than ext4_error.  The
605  * abort function may be used to deal with unrecoverable failures such
606  * as journal IO errors or ENOMEM at a critical moment in log management.
607  *
608  * We unconditionally force the filesystem into an ABORT|READONLY state,
609  * unless the error response on the fs has been set to panic in which
610  * case we take the easy way out and panic immediately.
611  */
612 
613 void __ext4_abort(struct super_block *sb, const char *function,
614 		unsigned int line, const char *fmt, ...)
615 {
616 	struct va_format vaf;
617 	va_list args;
618 
619 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
620 		return;
621 
622 	save_error_info(sb, function, line);
623 	va_start(args, fmt);
624 	vaf.fmt = fmt;
625 	vaf.va = &args;
626 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
627 	       sb->s_id, function, line, &vaf);
628 	va_end(args);
629 
630 	if (sb_rdonly(sb) == 0) {
631 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
632 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
633 		/*
634 		 * Make sure updated value of ->s_mount_flags will be visible
635 		 * before ->s_flags update
636 		 */
637 		smp_wmb();
638 		sb->s_flags |= SB_RDONLY;
639 		if (EXT4_SB(sb)->s_journal)
640 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
641 		save_error_info(sb, function, line);
642 	}
643 	if (test_opt(sb, ERRORS_PANIC)) {
644 		if (EXT4_SB(sb)->s_journal &&
645 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
646 			return;
647 		panic("EXT4-fs panic from previous error\n");
648 	}
649 }
650 
651 void __ext4_msg(struct super_block *sb,
652 		const char *prefix, const char *fmt, ...)
653 {
654 	struct va_format vaf;
655 	va_list args;
656 
657 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
658 		return;
659 
660 	va_start(args, fmt);
661 	vaf.fmt = fmt;
662 	vaf.va = &args;
663 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
664 	va_end(args);
665 }
666 
667 #define ext4_warning_ratelimit(sb)					\
668 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
669 			     "EXT4-fs warning")
670 
671 void __ext4_warning(struct super_block *sb, const char *function,
672 		    unsigned int line, const char *fmt, ...)
673 {
674 	struct va_format vaf;
675 	va_list args;
676 
677 	if (!ext4_warning_ratelimit(sb))
678 		return;
679 
680 	va_start(args, fmt);
681 	vaf.fmt = fmt;
682 	vaf.va = &args;
683 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
684 	       sb->s_id, function, line, &vaf);
685 	va_end(args);
686 }
687 
688 void __ext4_warning_inode(const struct inode *inode, const char *function,
689 			  unsigned int line, const char *fmt, ...)
690 {
691 	struct va_format vaf;
692 	va_list args;
693 
694 	if (!ext4_warning_ratelimit(inode->i_sb))
695 		return;
696 
697 	va_start(args, fmt);
698 	vaf.fmt = fmt;
699 	vaf.va = &args;
700 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
701 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
702 	       function, line, inode->i_ino, current->comm, &vaf);
703 	va_end(args);
704 }
705 
706 void __ext4_grp_locked_error(const char *function, unsigned int line,
707 			     struct super_block *sb, ext4_group_t grp,
708 			     unsigned long ino, ext4_fsblk_t block,
709 			     const char *fmt, ...)
710 __releases(bitlock)
711 __acquires(bitlock)
712 {
713 	struct va_format vaf;
714 	va_list args;
715 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
716 
717 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
718 		return;
719 
720 	es->s_last_error_ino = cpu_to_le32(ino);
721 	es->s_last_error_block = cpu_to_le64(block);
722 	__save_error_info(sb, function, line);
723 
724 	if (ext4_error_ratelimit(sb)) {
725 		va_start(args, fmt);
726 		vaf.fmt = fmt;
727 		vaf.va = &args;
728 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
729 		       sb->s_id, function, line, grp);
730 		if (ino)
731 			printk(KERN_CONT "inode %lu: ", ino);
732 		if (block)
733 			printk(KERN_CONT "block %llu:",
734 			       (unsigned long long) block);
735 		printk(KERN_CONT "%pV\n", &vaf);
736 		va_end(args);
737 	}
738 
739 	if (test_opt(sb, ERRORS_CONT)) {
740 		ext4_commit_super(sb, 0);
741 		return;
742 	}
743 
744 	ext4_unlock_group(sb, grp);
745 	ext4_handle_error(sb);
746 	/*
747 	 * We only get here in the ERRORS_RO case; relocking the group
748 	 * may be dangerous, but nothing bad will happen since the
749 	 * filesystem will have already been marked read/only and the
750 	 * journal has been aborted.  We return 1 as a hint to callers
751 	 * who might what to use the return value from
752 	 * ext4_grp_locked_error() to distinguish between the
753 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
754 	 * aggressively from the ext4 function in question, with a
755 	 * more appropriate error code.
756 	 */
757 	ext4_lock_group(sb, grp);
758 	return;
759 }
760 
761 void ext4_update_dynamic_rev(struct super_block *sb)
762 {
763 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
764 
765 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
766 		return;
767 
768 	ext4_warning(sb,
769 		     "updating to rev %d because of new feature flag, "
770 		     "running e2fsck is recommended",
771 		     EXT4_DYNAMIC_REV);
772 
773 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
774 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
775 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
776 	/* leave es->s_feature_*compat flags alone */
777 	/* es->s_uuid will be set by e2fsck if empty */
778 
779 	/*
780 	 * The rest of the superblock fields should be zero, and if not it
781 	 * means they are likely already in use, so leave them alone.  We
782 	 * can leave it up to e2fsck to clean up any inconsistencies there.
783 	 */
784 }
785 
786 /*
787  * Open the external journal device
788  */
789 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
790 {
791 	struct block_device *bdev;
792 	char b[BDEVNAME_SIZE];
793 
794 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
795 	if (IS_ERR(bdev))
796 		goto fail;
797 	return bdev;
798 
799 fail:
800 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
801 			__bdevname(dev, b), PTR_ERR(bdev));
802 	return NULL;
803 }
804 
805 /*
806  * Release the journal device
807  */
808 static void ext4_blkdev_put(struct block_device *bdev)
809 {
810 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
811 }
812 
813 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
814 {
815 	struct block_device *bdev;
816 	bdev = sbi->journal_bdev;
817 	if (bdev) {
818 		ext4_blkdev_put(bdev);
819 		sbi->journal_bdev = NULL;
820 	}
821 }
822 
823 static inline struct inode *orphan_list_entry(struct list_head *l)
824 {
825 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
826 }
827 
828 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
829 {
830 	struct list_head *l;
831 
832 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
833 		 le32_to_cpu(sbi->s_es->s_last_orphan));
834 
835 	printk(KERN_ERR "sb_info orphan list:\n");
836 	list_for_each(l, &sbi->s_orphan) {
837 		struct inode *inode = orphan_list_entry(l);
838 		printk(KERN_ERR "  "
839 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
840 		       inode->i_sb->s_id, inode->i_ino, inode,
841 		       inode->i_mode, inode->i_nlink,
842 		       NEXT_ORPHAN(inode));
843 	}
844 }
845 
846 #ifdef CONFIG_QUOTA
847 static int ext4_quota_off(struct super_block *sb, int type);
848 
849 static inline void ext4_quota_off_umount(struct super_block *sb)
850 {
851 	int type;
852 
853 	/* Use our quota_off function to clear inode flags etc. */
854 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
855 		ext4_quota_off(sb, type);
856 }
857 #else
858 static inline void ext4_quota_off_umount(struct super_block *sb)
859 {
860 }
861 #endif
862 
863 static void ext4_put_super(struct super_block *sb)
864 {
865 	struct ext4_sb_info *sbi = EXT4_SB(sb);
866 	struct ext4_super_block *es = sbi->s_es;
867 	int aborted = 0;
868 	int i, err;
869 
870 	ext4_unregister_li_request(sb);
871 	ext4_quota_off_umount(sb);
872 
873 	flush_workqueue(sbi->rsv_conversion_wq);
874 	destroy_workqueue(sbi->rsv_conversion_wq);
875 
876 	if (sbi->s_journal) {
877 		aborted = is_journal_aborted(sbi->s_journal);
878 		err = jbd2_journal_destroy(sbi->s_journal);
879 		sbi->s_journal = NULL;
880 		if ((err < 0) && !aborted)
881 			ext4_abort(sb, "Couldn't clean up the journal");
882 	}
883 
884 	ext4_unregister_sysfs(sb);
885 	ext4_es_unregister_shrinker(sbi);
886 	del_timer_sync(&sbi->s_err_report);
887 	ext4_release_system_zone(sb);
888 	ext4_mb_release(sb);
889 	ext4_ext_release(sb);
890 
891 	if (!sb_rdonly(sb) && !aborted) {
892 		ext4_clear_feature_journal_needs_recovery(sb);
893 		es->s_state = cpu_to_le16(sbi->s_mount_state);
894 	}
895 	if (!sb_rdonly(sb))
896 		ext4_commit_super(sb, 1);
897 
898 	for (i = 0; i < sbi->s_gdb_count; i++)
899 		brelse(sbi->s_group_desc[i]);
900 	kvfree(sbi->s_group_desc);
901 	kvfree(sbi->s_flex_groups);
902 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
903 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
904 	percpu_counter_destroy(&sbi->s_dirs_counter);
905 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
906 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
907 #ifdef CONFIG_QUOTA
908 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
909 		kfree(sbi->s_qf_names[i]);
910 #endif
911 
912 	/* Debugging code just in case the in-memory inode orphan list
913 	 * isn't empty.  The on-disk one can be non-empty if we've
914 	 * detected an error and taken the fs readonly, but the
915 	 * in-memory list had better be clean by this point. */
916 	if (!list_empty(&sbi->s_orphan))
917 		dump_orphan_list(sb, sbi);
918 	J_ASSERT(list_empty(&sbi->s_orphan));
919 
920 	sync_blockdev(sb->s_bdev);
921 	invalidate_bdev(sb->s_bdev);
922 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
923 		/*
924 		 * Invalidate the journal device's buffers.  We don't want them
925 		 * floating about in memory - the physical journal device may
926 		 * hotswapped, and it breaks the `ro-after' testing code.
927 		 */
928 		sync_blockdev(sbi->journal_bdev);
929 		invalidate_bdev(sbi->journal_bdev);
930 		ext4_blkdev_remove(sbi);
931 	}
932 	if (sbi->s_ea_inode_cache) {
933 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
934 		sbi->s_ea_inode_cache = NULL;
935 	}
936 	if (sbi->s_ea_block_cache) {
937 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
938 		sbi->s_ea_block_cache = NULL;
939 	}
940 	if (sbi->s_mmp_tsk)
941 		kthread_stop(sbi->s_mmp_tsk);
942 	brelse(sbi->s_sbh);
943 	sb->s_fs_info = NULL;
944 	/*
945 	 * Now that we are completely done shutting down the
946 	 * superblock, we need to actually destroy the kobject.
947 	 */
948 	kobject_put(&sbi->s_kobj);
949 	wait_for_completion(&sbi->s_kobj_unregister);
950 	if (sbi->s_chksum_driver)
951 		crypto_free_shash(sbi->s_chksum_driver);
952 	kfree(sbi->s_blockgroup_lock);
953 	fs_put_dax(sbi->s_daxdev);
954 	kfree(sbi);
955 }
956 
957 static struct kmem_cache *ext4_inode_cachep;
958 
959 /*
960  * Called inside transaction, so use GFP_NOFS
961  */
962 static struct inode *ext4_alloc_inode(struct super_block *sb)
963 {
964 	struct ext4_inode_info *ei;
965 
966 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
967 	if (!ei)
968 		return NULL;
969 
970 	ei->vfs_inode.i_version = 1;
971 	spin_lock_init(&ei->i_raw_lock);
972 	INIT_LIST_HEAD(&ei->i_prealloc_list);
973 	spin_lock_init(&ei->i_prealloc_lock);
974 	ext4_es_init_tree(&ei->i_es_tree);
975 	rwlock_init(&ei->i_es_lock);
976 	INIT_LIST_HEAD(&ei->i_es_list);
977 	ei->i_es_all_nr = 0;
978 	ei->i_es_shk_nr = 0;
979 	ei->i_es_shrink_lblk = 0;
980 	ei->i_reserved_data_blocks = 0;
981 	ei->i_da_metadata_calc_len = 0;
982 	ei->i_da_metadata_calc_last_lblock = 0;
983 	spin_lock_init(&(ei->i_block_reservation_lock));
984 #ifdef CONFIG_QUOTA
985 	ei->i_reserved_quota = 0;
986 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
987 #endif
988 	ei->jinode = NULL;
989 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
990 	spin_lock_init(&ei->i_completed_io_lock);
991 	ei->i_sync_tid = 0;
992 	ei->i_datasync_tid = 0;
993 	atomic_set(&ei->i_unwritten, 0);
994 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
995 	return &ei->vfs_inode;
996 }
997 
998 static int ext4_drop_inode(struct inode *inode)
999 {
1000 	int drop = generic_drop_inode(inode);
1001 
1002 	trace_ext4_drop_inode(inode, drop);
1003 	return drop;
1004 }
1005 
1006 static void ext4_i_callback(struct rcu_head *head)
1007 {
1008 	struct inode *inode = container_of(head, struct inode, i_rcu);
1009 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1010 }
1011 
1012 static void ext4_destroy_inode(struct inode *inode)
1013 {
1014 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1015 		ext4_msg(inode->i_sb, KERN_ERR,
1016 			 "Inode %lu (%p): orphan list check failed!",
1017 			 inode->i_ino, EXT4_I(inode));
1018 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1019 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1020 				true);
1021 		dump_stack();
1022 	}
1023 	call_rcu(&inode->i_rcu, ext4_i_callback);
1024 }
1025 
1026 static void init_once(void *foo)
1027 {
1028 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1029 
1030 	INIT_LIST_HEAD(&ei->i_orphan);
1031 	init_rwsem(&ei->xattr_sem);
1032 	init_rwsem(&ei->i_data_sem);
1033 	init_rwsem(&ei->i_mmap_sem);
1034 	inode_init_once(&ei->vfs_inode);
1035 }
1036 
1037 static int __init init_inodecache(void)
1038 {
1039 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1040 					     sizeof(struct ext4_inode_info),
1041 					     0, (SLAB_RECLAIM_ACCOUNT|
1042 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1043 					     init_once);
1044 	if (ext4_inode_cachep == NULL)
1045 		return -ENOMEM;
1046 	return 0;
1047 }
1048 
1049 static void destroy_inodecache(void)
1050 {
1051 	/*
1052 	 * Make sure all delayed rcu free inodes are flushed before we
1053 	 * destroy cache.
1054 	 */
1055 	rcu_barrier();
1056 	kmem_cache_destroy(ext4_inode_cachep);
1057 }
1058 
1059 void ext4_clear_inode(struct inode *inode)
1060 {
1061 	invalidate_inode_buffers(inode);
1062 	clear_inode(inode);
1063 	dquot_drop(inode);
1064 	ext4_discard_preallocations(inode);
1065 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1066 	if (EXT4_I(inode)->jinode) {
1067 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1068 					       EXT4_I(inode)->jinode);
1069 		jbd2_free_inode(EXT4_I(inode)->jinode);
1070 		EXT4_I(inode)->jinode = NULL;
1071 	}
1072 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1073 	fscrypt_put_encryption_info(inode, NULL);
1074 #endif
1075 }
1076 
1077 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1078 					u64 ino, u32 generation)
1079 {
1080 	struct inode *inode;
1081 
1082 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1083 		return ERR_PTR(-ESTALE);
1084 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1085 		return ERR_PTR(-ESTALE);
1086 
1087 	/* iget isn't really right if the inode is currently unallocated!!
1088 	 *
1089 	 * ext4_read_inode will return a bad_inode if the inode had been
1090 	 * deleted, so we should be safe.
1091 	 *
1092 	 * Currently we don't know the generation for parent directory, so
1093 	 * a generation of 0 means "accept any"
1094 	 */
1095 	inode = ext4_iget_normal(sb, ino);
1096 	if (IS_ERR(inode))
1097 		return ERR_CAST(inode);
1098 	if (generation && inode->i_generation != generation) {
1099 		iput(inode);
1100 		return ERR_PTR(-ESTALE);
1101 	}
1102 
1103 	return inode;
1104 }
1105 
1106 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1107 					int fh_len, int fh_type)
1108 {
1109 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1110 				    ext4_nfs_get_inode);
1111 }
1112 
1113 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1114 					int fh_len, int fh_type)
1115 {
1116 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1117 				    ext4_nfs_get_inode);
1118 }
1119 
1120 /*
1121  * Try to release metadata pages (indirect blocks, directories) which are
1122  * mapped via the block device.  Since these pages could have journal heads
1123  * which would prevent try_to_free_buffers() from freeing them, we must use
1124  * jbd2 layer's try_to_free_buffers() function to release them.
1125  */
1126 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1127 				 gfp_t wait)
1128 {
1129 	journal_t *journal = EXT4_SB(sb)->s_journal;
1130 
1131 	WARN_ON(PageChecked(page));
1132 	if (!page_has_buffers(page))
1133 		return 0;
1134 	if (journal)
1135 		return jbd2_journal_try_to_free_buffers(journal, page,
1136 						wait & ~__GFP_DIRECT_RECLAIM);
1137 	return try_to_free_buffers(page);
1138 }
1139 
1140 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1141 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1142 {
1143 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1144 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1145 }
1146 
1147 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1148 							void *fs_data)
1149 {
1150 	handle_t *handle = fs_data;
1151 	int res, res2, credits, retries = 0;
1152 
1153 	/*
1154 	 * Encrypting the root directory is not allowed because e2fsck expects
1155 	 * lost+found to exist and be unencrypted, and encrypting the root
1156 	 * directory would imply encrypting the lost+found directory as well as
1157 	 * the filename "lost+found" itself.
1158 	 */
1159 	if (inode->i_ino == EXT4_ROOT_INO)
1160 		return -EPERM;
1161 
1162 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1163 		return -EINVAL;
1164 
1165 	res = ext4_convert_inline_data(inode);
1166 	if (res)
1167 		return res;
1168 
1169 	/*
1170 	 * If a journal handle was specified, then the encryption context is
1171 	 * being set on a new inode via inheritance and is part of a larger
1172 	 * transaction to create the inode.  Otherwise the encryption context is
1173 	 * being set on an existing inode in its own transaction.  Only in the
1174 	 * latter case should the "retry on ENOSPC" logic be used.
1175 	 */
1176 
1177 	if (handle) {
1178 		res = ext4_xattr_set_handle(handle, inode,
1179 					    EXT4_XATTR_INDEX_ENCRYPTION,
1180 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1181 					    ctx, len, 0);
1182 		if (!res) {
1183 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1184 			ext4_clear_inode_state(inode,
1185 					EXT4_STATE_MAY_INLINE_DATA);
1186 			/*
1187 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1188 			 * S_DAX may be disabled
1189 			 */
1190 			ext4_set_inode_flags(inode);
1191 		}
1192 		return res;
1193 	}
1194 
1195 	res = dquot_initialize(inode);
1196 	if (res)
1197 		return res;
1198 retry:
1199 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1200 				     &credits);
1201 	if (res)
1202 		return res;
1203 
1204 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1205 	if (IS_ERR(handle))
1206 		return PTR_ERR(handle);
1207 
1208 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1209 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1210 				    ctx, len, 0);
1211 	if (!res) {
1212 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1213 		/*
1214 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1215 		 * S_DAX may be disabled
1216 		 */
1217 		ext4_set_inode_flags(inode);
1218 		res = ext4_mark_inode_dirty(handle, inode);
1219 		if (res)
1220 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1221 	}
1222 	res2 = ext4_journal_stop(handle);
1223 
1224 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1225 		goto retry;
1226 	if (!res)
1227 		res = res2;
1228 	return res;
1229 }
1230 
1231 static bool ext4_dummy_context(struct inode *inode)
1232 {
1233 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1234 }
1235 
1236 static unsigned ext4_max_namelen(struct inode *inode)
1237 {
1238 	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1239 		EXT4_NAME_LEN;
1240 }
1241 
1242 static const struct fscrypt_operations ext4_cryptops = {
1243 	.key_prefix		= "ext4:",
1244 	.get_context		= ext4_get_context,
1245 	.set_context		= ext4_set_context,
1246 	.dummy_context		= ext4_dummy_context,
1247 	.empty_dir		= ext4_empty_dir,
1248 	.max_namelen		= ext4_max_namelen,
1249 };
1250 #endif
1251 
1252 #ifdef CONFIG_QUOTA
1253 static const char * const quotatypes[] = INITQFNAMES;
1254 #define QTYPE2NAME(t) (quotatypes[t])
1255 
1256 static int ext4_write_dquot(struct dquot *dquot);
1257 static int ext4_acquire_dquot(struct dquot *dquot);
1258 static int ext4_release_dquot(struct dquot *dquot);
1259 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1260 static int ext4_write_info(struct super_block *sb, int type);
1261 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1262 			 const struct path *path);
1263 static int ext4_quota_on_mount(struct super_block *sb, int type);
1264 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1265 			       size_t len, loff_t off);
1266 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1267 				const char *data, size_t len, loff_t off);
1268 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1269 			     unsigned int flags);
1270 static int ext4_enable_quotas(struct super_block *sb);
1271 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1272 
1273 static struct dquot **ext4_get_dquots(struct inode *inode)
1274 {
1275 	return EXT4_I(inode)->i_dquot;
1276 }
1277 
1278 static const struct dquot_operations ext4_quota_operations = {
1279 	.get_reserved_space	= ext4_get_reserved_space,
1280 	.write_dquot		= ext4_write_dquot,
1281 	.acquire_dquot		= ext4_acquire_dquot,
1282 	.release_dquot		= ext4_release_dquot,
1283 	.mark_dirty		= ext4_mark_dquot_dirty,
1284 	.write_info		= ext4_write_info,
1285 	.alloc_dquot		= dquot_alloc,
1286 	.destroy_dquot		= dquot_destroy,
1287 	.get_projid		= ext4_get_projid,
1288 	.get_inode_usage	= ext4_get_inode_usage,
1289 	.get_next_id		= ext4_get_next_id,
1290 };
1291 
1292 static const struct quotactl_ops ext4_qctl_operations = {
1293 	.quota_on	= ext4_quota_on,
1294 	.quota_off	= ext4_quota_off,
1295 	.quota_sync	= dquot_quota_sync,
1296 	.get_state	= dquot_get_state,
1297 	.set_info	= dquot_set_dqinfo,
1298 	.get_dqblk	= dquot_get_dqblk,
1299 	.set_dqblk	= dquot_set_dqblk,
1300 	.get_nextdqblk	= dquot_get_next_dqblk,
1301 };
1302 #endif
1303 
1304 static const struct super_operations ext4_sops = {
1305 	.alloc_inode	= ext4_alloc_inode,
1306 	.destroy_inode	= ext4_destroy_inode,
1307 	.write_inode	= ext4_write_inode,
1308 	.dirty_inode	= ext4_dirty_inode,
1309 	.drop_inode	= ext4_drop_inode,
1310 	.evict_inode	= ext4_evict_inode,
1311 	.put_super	= ext4_put_super,
1312 	.sync_fs	= ext4_sync_fs,
1313 	.freeze_fs	= ext4_freeze,
1314 	.unfreeze_fs	= ext4_unfreeze,
1315 	.statfs		= ext4_statfs,
1316 	.remount_fs	= ext4_remount,
1317 	.show_options	= ext4_show_options,
1318 #ifdef CONFIG_QUOTA
1319 	.quota_read	= ext4_quota_read,
1320 	.quota_write	= ext4_quota_write,
1321 	.get_dquots	= ext4_get_dquots,
1322 #endif
1323 	.bdev_try_to_free_page = bdev_try_to_free_page,
1324 };
1325 
1326 static const struct export_operations ext4_export_ops = {
1327 	.fh_to_dentry = ext4_fh_to_dentry,
1328 	.fh_to_parent = ext4_fh_to_parent,
1329 	.get_parent = ext4_get_parent,
1330 };
1331 
1332 enum {
1333 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1334 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1335 	Opt_nouid32, Opt_debug, Opt_removed,
1336 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1337 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1338 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1339 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1340 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1341 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1342 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1343 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1344 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1345 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1346 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1347 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1348 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1349 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1350 	Opt_dioread_nolock, Opt_dioread_lock,
1351 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1352 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1353 };
1354 
1355 static const match_table_t tokens = {
1356 	{Opt_bsd_df, "bsddf"},
1357 	{Opt_minix_df, "minixdf"},
1358 	{Opt_grpid, "grpid"},
1359 	{Opt_grpid, "bsdgroups"},
1360 	{Opt_nogrpid, "nogrpid"},
1361 	{Opt_nogrpid, "sysvgroups"},
1362 	{Opt_resgid, "resgid=%u"},
1363 	{Opt_resuid, "resuid=%u"},
1364 	{Opt_sb, "sb=%u"},
1365 	{Opt_err_cont, "errors=continue"},
1366 	{Opt_err_panic, "errors=panic"},
1367 	{Opt_err_ro, "errors=remount-ro"},
1368 	{Opt_nouid32, "nouid32"},
1369 	{Opt_debug, "debug"},
1370 	{Opt_removed, "oldalloc"},
1371 	{Opt_removed, "orlov"},
1372 	{Opt_user_xattr, "user_xattr"},
1373 	{Opt_nouser_xattr, "nouser_xattr"},
1374 	{Opt_acl, "acl"},
1375 	{Opt_noacl, "noacl"},
1376 	{Opt_noload, "norecovery"},
1377 	{Opt_noload, "noload"},
1378 	{Opt_removed, "nobh"},
1379 	{Opt_removed, "bh"},
1380 	{Opt_commit, "commit=%u"},
1381 	{Opt_min_batch_time, "min_batch_time=%u"},
1382 	{Opt_max_batch_time, "max_batch_time=%u"},
1383 	{Opt_journal_dev, "journal_dev=%u"},
1384 	{Opt_journal_path, "journal_path=%s"},
1385 	{Opt_journal_checksum, "journal_checksum"},
1386 	{Opt_nojournal_checksum, "nojournal_checksum"},
1387 	{Opt_journal_async_commit, "journal_async_commit"},
1388 	{Opt_abort, "abort"},
1389 	{Opt_data_journal, "data=journal"},
1390 	{Opt_data_ordered, "data=ordered"},
1391 	{Opt_data_writeback, "data=writeback"},
1392 	{Opt_data_err_abort, "data_err=abort"},
1393 	{Opt_data_err_ignore, "data_err=ignore"},
1394 	{Opt_offusrjquota, "usrjquota="},
1395 	{Opt_usrjquota, "usrjquota=%s"},
1396 	{Opt_offgrpjquota, "grpjquota="},
1397 	{Opt_grpjquota, "grpjquota=%s"},
1398 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1399 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1400 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1401 	{Opt_grpquota, "grpquota"},
1402 	{Opt_noquota, "noquota"},
1403 	{Opt_quota, "quota"},
1404 	{Opt_usrquota, "usrquota"},
1405 	{Opt_prjquota, "prjquota"},
1406 	{Opt_barrier, "barrier=%u"},
1407 	{Opt_barrier, "barrier"},
1408 	{Opt_nobarrier, "nobarrier"},
1409 	{Opt_i_version, "i_version"},
1410 	{Opt_dax, "dax"},
1411 	{Opt_stripe, "stripe=%u"},
1412 	{Opt_delalloc, "delalloc"},
1413 	{Opt_lazytime, "lazytime"},
1414 	{Opt_nolazytime, "nolazytime"},
1415 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1416 	{Opt_nodelalloc, "nodelalloc"},
1417 	{Opt_removed, "mblk_io_submit"},
1418 	{Opt_removed, "nomblk_io_submit"},
1419 	{Opt_block_validity, "block_validity"},
1420 	{Opt_noblock_validity, "noblock_validity"},
1421 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1422 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1423 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1424 	{Opt_auto_da_alloc, "auto_da_alloc"},
1425 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1426 	{Opt_dioread_nolock, "dioread_nolock"},
1427 	{Opt_dioread_lock, "dioread_lock"},
1428 	{Opt_discard, "discard"},
1429 	{Opt_nodiscard, "nodiscard"},
1430 	{Opt_init_itable, "init_itable=%u"},
1431 	{Opt_init_itable, "init_itable"},
1432 	{Opt_noinit_itable, "noinit_itable"},
1433 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1434 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1435 	{Opt_nombcache, "nombcache"},
1436 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1437 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1438 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1439 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1440 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1441 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1442 	{Opt_err, NULL},
1443 };
1444 
1445 static ext4_fsblk_t get_sb_block(void **data)
1446 {
1447 	ext4_fsblk_t	sb_block;
1448 	char		*options = (char *) *data;
1449 
1450 	if (!options || strncmp(options, "sb=", 3) != 0)
1451 		return 1;	/* Default location */
1452 
1453 	options += 3;
1454 	/* TODO: use simple_strtoll with >32bit ext4 */
1455 	sb_block = simple_strtoul(options, &options, 0);
1456 	if (*options && *options != ',') {
1457 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1458 		       (char *) *data);
1459 		return 1;
1460 	}
1461 	if (*options == ',')
1462 		options++;
1463 	*data = (void *) options;
1464 
1465 	return sb_block;
1466 }
1467 
1468 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1469 static const char deprecated_msg[] =
1470 	"Mount option \"%s\" will be removed by %s\n"
1471 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1472 
1473 #ifdef CONFIG_QUOTA
1474 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1475 {
1476 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1477 	char *qname;
1478 	int ret = -1;
1479 
1480 	if (sb_any_quota_loaded(sb) &&
1481 		!sbi->s_qf_names[qtype]) {
1482 		ext4_msg(sb, KERN_ERR,
1483 			"Cannot change journaled "
1484 			"quota options when quota turned on");
1485 		return -1;
1486 	}
1487 	if (ext4_has_feature_quota(sb)) {
1488 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1489 			 "ignored when QUOTA feature is enabled");
1490 		return 1;
1491 	}
1492 	qname = match_strdup(args);
1493 	if (!qname) {
1494 		ext4_msg(sb, KERN_ERR,
1495 			"Not enough memory for storing quotafile name");
1496 		return -1;
1497 	}
1498 	if (sbi->s_qf_names[qtype]) {
1499 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1500 			ret = 1;
1501 		else
1502 			ext4_msg(sb, KERN_ERR,
1503 				 "%s quota file already specified",
1504 				 QTYPE2NAME(qtype));
1505 		goto errout;
1506 	}
1507 	if (strchr(qname, '/')) {
1508 		ext4_msg(sb, KERN_ERR,
1509 			"quotafile must be on filesystem root");
1510 		goto errout;
1511 	}
1512 	sbi->s_qf_names[qtype] = qname;
1513 	set_opt(sb, QUOTA);
1514 	return 1;
1515 errout:
1516 	kfree(qname);
1517 	return ret;
1518 }
1519 
1520 static int clear_qf_name(struct super_block *sb, int qtype)
1521 {
1522 
1523 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1524 
1525 	if (sb_any_quota_loaded(sb) &&
1526 		sbi->s_qf_names[qtype]) {
1527 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1528 			" when quota turned on");
1529 		return -1;
1530 	}
1531 	kfree(sbi->s_qf_names[qtype]);
1532 	sbi->s_qf_names[qtype] = NULL;
1533 	return 1;
1534 }
1535 #endif
1536 
1537 #define MOPT_SET	0x0001
1538 #define MOPT_CLEAR	0x0002
1539 #define MOPT_NOSUPPORT	0x0004
1540 #define MOPT_EXPLICIT	0x0008
1541 #define MOPT_CLEAR_ERR	0x0010
1542 #define MOPT_GTE0	0x0020
1543 #ifdef CONFIG_QUOTA
1544 #define MOPT_Q		0
1545 #define MOPT_QFMT	0x0040
1546 #else
1547 #define MOPT_Q		MOPT_NOSUPPORT
1548 #define MOPT_QFMT	MOPT_NOSUPPORT
1549 #endif
1550 #define MOPT_DATAJ	0x0080
1551 #define MOPT_NO_EXT2	0x0100
1552 #define MOPT_NO_EXT3	0x0200
1553 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1554 #define MOPT_STRING	0x0400
1555 
1556 static const struct mount_opts {
1557 	int	token;
1558 	int	mount_opt;
1559 	int	flags;
1560 } ext4_mount_opts[] = {
1561 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1562 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1563 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1564 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1565 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1566 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1567 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1568 	 MOPT_EXT4_ONLY | MOPT_SET},
1569 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1570 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1571 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1572 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1573 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1574 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1575 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1576 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1577 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1578 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1579 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1580 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1581 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1582 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1583 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1584 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1585 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1586 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1587 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1588 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1589 	 MOPT_NO_EXT2},
1590 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1591 	 MOPT_NO_EXT2},
1592 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1593 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1594 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1595 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1596 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1597 	{Opt_commit, 0, MOPT_GTE0},
1598 	{Opt_max_batch_time, 0, MOPT_GTE0},
1599 	{Opt_min_batch_time, 0, MOPT_GTE0},
1600 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1601 	{Opt_init_itable, 0, MOPT_GTE0},
1602 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1603 	{Opt_stripe, 0, MOPT_GTE0},
1604 	{Opt_resuid, 0, MOPT_GTE0},
1605 	{Opt_resgid, 0, MOPT_GTE0},
1606 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1607 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1608 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1609 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1610 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1611 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1612 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1613 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1614 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1615 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1616 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1617 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1618 #else
1619 	{Opt_acl, 0, MOPT_NOSUPPORT},
1620 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1621 #endif
1622 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1623 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1624 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1625 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1626 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1627 							MOPT_SET | MOPT_Q},
1628 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1629 							MOPT_SET | MOPT_Q},
1630 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1631 							MOPT_SET | MOPT_Q},
1632 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1633 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1634 							MOPT_CLEAR | MOPT_Q},
1635 	{Opt_usrjquota, 0, MOPT_Q},
1636 	{Opt_grpjquota, 0, MOPT_Q},
1637 	{Opt_offusrjquota, 0, MOPT_Q},
1638 	{Opt_offgrpjquota, 0, MOPT_Q},
1639 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1640 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1641 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1642 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1643 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1644 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1645 	{Opt_err, 0, 0}
1646 };
1647 
1648 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1649 			    substring_t *args, unsigned long *journal_devnum,
1650 			    unsigned int *journal_ioprio, int is_remount)
1651 {
1652 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1653 	const struct mount_opts *m;
1654 	kuid_t uid;
1655 	kgid_t gid;
1656 	int arg = 0;
1657 
1658 #ifdef CONFIG_QUOTA
1659 	if (token == Opt_usrjquota)
1660 		return set_qf_name(sb, USRQUOTA, &args[0]);
1661 	else if (token == Opt_grpjquota)
1662 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1663 	else if (token == Opt_offusrjquota)
1664 		return clear_qf_name(sb, USRQUOTA);
1665 	else if (token == Opt_offgrpjquota)
1666 		return clear_qf_name(sb, GRPQUOTA);
1667 #endif
1668 	switch (token) {
1669 	case Opt_noacl:
1670 	case Opt_nouser_xattr:
1671 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1672 		break;
1673 	case Opt_sb:
1674 		return 1;	/* handled by get_sb_block() */
1675 	case Opt_removed:
1676 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1677 		return 1;
1678 	case Opt_abort:
1679 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1680 		return 1;
1681 	case Opt_i_version:
1682 		sb->s_flags |= SB_I_VERSION;
1683 		return 1;
1684 	case Opt_lazytime:
1685 		sb->s_flags |= SB_LAZYTIME;
1686 		return 1;
1687 	case Opt_nolazytime:
1688 		sb->s_flags &= ~SB_LAZYTIME;
1689 		return 1;
1690 	}
1691 
1692 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1693 		if (token == m->token)
1694 			break;
1695 
1696 	if (m->token == Opt_err) {
1697 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1698 			 "or missing value", opt);
1699 		return -1;
1700 	}
1701 
1702 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1703 		ext4_msg(sb, KERN_ERR,
1704 			 "Mount option \"%s\" incompatible with ext2", opt);
1705 		return -1;
1706 	}
1707 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1708 		ext4_msg(sb, KERN_ERR,
1709 			 "Mount option \"%s\" incompatible with ext3", opt);
1710 		return -1;
1711 	}
1712 
1713 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1714 		return -1;
1715 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1716 		return -1;
1717 	if (m->flags & MOPT_EXPLICIT) {
1718 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1719 			set_opt2(sb, EXPLICIT_DELALLOC);
1720 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1721 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1722 		} else
1723 			return -1;
1724 	}
1725 	if (m->flags & MOPT_CLEAR_ERR)
1726 		clear_opt(sb, ERRORS_MASK);
1727 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1728 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1729 			 "options when quota turned on");
1730 		return -1;
1731 	}
1732 
1733 	if (m->flags & MOPT_NOSUPPORT) {
1734 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1735 	} else if (token == Opt_commit) {
1736 		if (arg == 0)
1737 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1738 		sbi->s_commit_interval = HZ * arg;
1739 	} else if (token == Opt_debug_want_extra_isize) {
1740 		sbi->s_want_extra_isize = arg;
1741 	} else if (token == Opt_max_batch_time) {
1742 		sbi->s_max_batch_time = arg;
1743 	} else if (token == Opt_min_batch_time) {
1744 		sbi->s_min_batch_time = arg;
1745 	} else if (token == Opt_inode_readahead_blks) {
1746 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1747 			ext4_msg(sb, KERN_ERR,
1748 				 "EXT4-fs: inode_readahead_blks must be "
1749 				 "0 or a power of 2 smaller than 2^31");
1750 			return -1;
1751 		}
1752 		sbi->s_inode_readahead_blks = arg;
1753 	} else if (token == Opt_init_itable) {
1754 		set_opt(sb, INIT_INODE_TABLE);
1755 		if (!args->from)
1756 			arg = EXT4_DEF_LI_WAIT_MULT;
1757 		sbi->s_li_wait_mult = arg;
1758 	} else if (token == Opt_max_dir_size_kb) {
1759 		sbi->s_max_dir_size_kb = arg;
1760 	} else if (token == Opt_stripe) {
1761 		sbi->s_stripe = arg;
1762 	} else if (token == Opt_resuid) {
1763 		uid = make_kuid(current_user_ns(), arg);
1764 		if (!uid_valid(uid)) {
1765 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1766 			return -1;
1767 		}
1768 		sbi->s_resuid = uid;
1769 	} else if (token == Opt_resgid) {
1770 		gid = make_kgid(current_user_ns(), arg);
1771 		if (!gid_valid(gid)) {
1772 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1773 			return -1;
1774 		}
1775 		sbi->s_resgid = gid;
1776 	} else if (token == Opt_journal_dev) {
1777 		if (is_remount) {
1778 			ext4_msg(sb, KERN_ERR,
1779 				 "Cannot specify journal on remount");
1780 			return -1;
1781 		}
1782 		*journal_devnum = arg;
1783 	} else if (token == Opt_journal_path) {
1784 		char *journal_path;
1785 		struct inode *journal_inode;
1786 		struct path path;
1787 		int error;
1788 
1789 		if (is_remount) {
1790 			ext4_msg(sb, KERN_ERR,
1791 				 "Cannot specify journal on remount");
1792 			return -1;
1793 		}
1794 		journal_path = match_strdup(&args[0]);
1795 		if (!journal_path) {
1796 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1797 				"journal device string");
1798 			return -1;
1799 		}
1800 
1801 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1802 		if (error) {
1803 			ext4_msg(sb, KERN_ERR, "error: could not find "
1804 				"journal device path: error %d", error);
1805 			kfree(journal_path);
1806 			return -1;
1807 		}
1808 
1809 		journal_inode = d_inode(path.dentry);
1810 		if (!S_ISBLK(journal_inode->i_mode)) {
1811 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1812 				"is not a block device", journal_path);
1813 			path_put(&path);
1814 			kfree(journal_path);
1815 			return -1;
1816 		}
1817 
1818 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1819 		path_put(&path);
1820 		kfree(journal_path);
1821 	} else if (token == Opt_journal_ioprio) {
1822 		if (arg > 7) {
1823 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1824 				 " (must be 0-7)");
1825 			return -1;
1826 		}
1827 		*journal_ioprio =
1828 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1829 	} else if (token == Opt_test_dummy_encryption) {
1830 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1831 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1832 		ext4_msg(sb, KERN_WARNING,
1833 			 "Test dummy encryption mode enabled");
1834 #else
1835 		ext4_msg(sb, KERN_WARNING,
1836 			 "Test dummy encryption mount option ignored");
1837 #endif
1838 	} else if (m->flags & MOPT_DATAJ) {
1839 		if (is_remount) {
1840 			if (!sbi->s_journal)
1841 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1842 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1843 				ext4_msg(sb, KERN_ERR,
1844 					 "Cannot change data mode on remount");
1845 				return -1;
1846 			}
1847 		} else {
1848 			clear_opt(sb, DATA_FLAGS);
1849 			sbi->s_mount_opt |= m->mount_opt;
1850 		}
1851 #ifdef CONFIG_QUOTA
1852 	} else if (m->flags & MOPT_QFMT) {
1853 		if (sb_any_quota_loaded(sb) &&
1854 		    sbi->s_jquota_fmt != m->mount_opt) {
1855 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1856 				 "quota options when quota turned on");
1857 			return -1;
1858 		}
1859 		if (ext4_has_feature_quota(sb)) {
1860 			ext4_msg(sb, KERN_INFO,
1861 				 "Quota format mount options ignored "
1862 				 "when QUOTA feature is enabled");
1863 			return 1;
1864 		}
1865 		sbi->s_jquota_fmt = m->mount_opt;
1866 #endif
1867 	} else if (token == Opt_dax) {
1868 #ifdef CONFIG_FS_DAX
1869 		ext4_msg(sb, KERN_WARNING,
1870 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1871 			sbi->s_mount_opt |= m->mount_opt;
1872 #else
1873 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1874 		return -1;
1875 #endif
1876 	} else if (token == Opt_data_err_abort) {
1877 		sbi->s_mount_opt |= m->mount_opt;
1878 	} else if (token == Opt_data_err_ignore) {
1879 		sbi->s_mount_opt &= ~m->mount_opt;
1880 	} else {
1881 		if (!args->from)
1882 			arg = 1;
1883 		if (m->flags & MOPT_CLEAR)
1884 			arg = !arg;
1885 		else if (unlikely(!(m->flags & MOPT_SET))) {
1886 			ext4_msg(sb, KERN_WARNING,
1887 				 "buggy handling of option %s", opt);
1888 			WARN_ON(1);
1889 			return -1;
1890 		}
1891 		if (arg != 0)
1892 			sbi->s_mount_opt |= m->mount_opt;
1893 		else
1894 			sbi->s_mount_opt &= ~m->mount_opt;
1895 	}
1896 	return 1;
1897 }
1898 
1899 static int parse_options(char *options, struct super_block *sb,
1900 			 unsigned long *journal_devnum,
1901 			 unsigned int *journal_ioprio,
1902 			 int is_remount)
1903 {
1904 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1905 	char *p;
1906 	substring_t args[MAX_OPT_ARGS];
1907 	int token;
1908 
1909 	if (!options)
1910 		return 1;
1911 
1912 	while ((p = strsep(&options, ",")) != NULL) {
1913 		if (!*p)
1914 			continue;
1915 		/*
1916 		 * Initialize args struct so we know whether arg was
1917 		 * found; some options take optional arguments.
1918 		 */
1919 		args[0].to = args[0].from = NULL;
1920 		token = match_token(p, tokens, args);
1921 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1922 				     journal_ioprio, is_remount) < 0)
1923 			return 0;
1924 	}
1925 #ifdef CONFIG_QUOTA
1926 	/*
1927 	 * We do the test below only for project quotas. 'usrquota' and
1928 	 * 'grpquota' mount options are allowed even without quota feature
1929 	 * to support legacy quotas in quota files.
1930 	 */
1931 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1932 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1933 			 "Cannot enable project quota enforcement.");
1934 		return 0;
1935 	}
1936 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1937 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1938 			clear_opt(sb, USRQUOTA);
1939 
1940 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1941 			clear_opt(sb, GRPQUOTA);
1942 
1943 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1944 			ext4_msg(sb, KERN_ERR, "old and new quota "
1945 					"format mixing");
1946 			return 0;
1947 		}
1948 
1949 		if (!sbi->s_jquota_fmt) {
1950 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1951 					"not specified");
1952 			return 0;
1953 		}
1954 	}
1955 #endif
1956 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1957 		int blocksize =
1958 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1959 
1960 		if (blocksize < PAGE_SIZE) {
1961 			ext4_msg(sb, KERN_ERR, "can't mount with "
1962 				 "dioread_nolock if block size != PAGE_SIZE");
1963 			return 0;
1964 		}
1965 	}
1966 	return 1;
1967 }
1968 
1969 static inline void ext4_show_quota_options(struct seq_file *seq,
1970 					   struct super_block *sb)
1971 {
1972 #if defined(CONFIG_QUOTA)
1973 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1974 
1975 	if (sbi->s_jquota_fmt) {
1976 		char *fmtname = "";
1977 
1978 		switch (sbi->s_jquota_fmt) {
1979 		case QFMT_VFS_OLD:
1980 			fmtname = "vfsold";
1981 			break;
1982 		case QFMT_VFS_V0:
1983 			fmtname = "vfsv0";
1984 			break;
1985 		case QFMT_VFS_V1:
1986 			fmtname = "vfsv1";
1987 			break;
1988 		}
1989 		seq_printf(seq, ",jqfmt=%s", fmtname);
1990 	}
1991 
1992 	if (sbi->s_qf_names[USRQUOTA])
1993 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1994 
1995 	if (sbi->s_qf_names[GRPQUOTA])
1996 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1997 #endif
1998 }
1999 
2000 static const char *token2str(int token)
2001 {
2002 	const struct match_token *t;
2003 
2004 	for (t = tokens; t->token != Opt_err; t++)
2005 		if (t->token == token && !strchr(t->pattern, '='))
2006 			break;
2007 	return t->pattern;
2008 }
2009 
2010 /*
2011  * Show an option if
2012  *  - it's set to a non-default value OR
2013  *  - if the per-sb default is different from the global default
2014  */
2015 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2016 			      int nodefs)
2017 {
2018 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2019 	struct ext4_super_block *es = sbi->s_es;
2020 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
2021 	const struct mount_opts *m;
2022 	char sep = nodefs ? '\n' : ',';
2023 
2024 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2025 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2026 
2027 	if (sbi->s_sb_block != 1)
2028 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2029 
2030 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2031 		int want_set = m->flags & MOPT_SET;
2032 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2033 		    (m->flags & MOPT_CLEAR_ERR))
2034 			continue;
2035 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2036 			continue; /* skip if same as the default */
2037 		if ((want_set &&
2038 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2039 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2040 			continue; /* select Opt_noFoo vs Opt_Foo */
2041 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2042 	}
2043 
2044 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2045 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2046 		SEQ_OPTS_PRINT("resuid=%u",
2047 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2048 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2049 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2050 		SEQ_OPTS_PRINT("resgid=%u",
2051 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2052 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2053 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2054 		SEQ_OPTS_PUTS("errors=remount-ro");
2055 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2056 		SEQ_OPTS_PUTS("errors=continue");
2057 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2058 		SEQ_OPTS_PUTS("errors=panic");
2059 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2060 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2061 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2062 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2063 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2064 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2065 	if (sb->s_flags & SB_I_VERSION)
2066 		SEQ_OPTS_PUTS("i_version");
2067 	if (nodefs || sbi->s_stripe)
2068 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2069 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2070 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2071 			SEQ_OPTS_PUTS("data=journal");
2072 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2073 			SEQ_OPTS_PUTS("data=ordered");
2074 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2075 			SEQ_OPTS_PUTS("data=writeback");
2076 	}
2077 	if (nodefs ||
2078 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2079 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2080 			       sbi->s_inode_readahead_blks);
2081 
2082 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2083 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2084 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2085 	if (nodefs || sbi->s_max_dir_size_kb)
2086 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2087 	if (test_opt(sb, DATA_ERR_ABORT))
2088 		SEQ_OPTS_PUTS("data_err=abort");
2089 
2090 	ext4_show_quota_options(seq, sb);
2091 	return 0;
2092 }
2093 
2094 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2095 {
2096 	return _ext4_show_options(seq, root->d_sb, 0);
2097 }
2098 
2099 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2100 {
2101 	struct super_block *sb = seq->private;
2102 	int rc;
2103 
2104 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2105 	rc = _ext4_show_options(seq, sb, 1);
2106 	seq_puts(seq, "\n");
2107 	return rc;
2108 }
2109 
2110 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2111 			    int read_only)
2112 {
2113 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2114 	int res = 0;
2115 
2116 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2117 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2118 			 "forcing read-only mode");
2119 		res = SB_RDONLY;
2120 	}
2121 	if (read_only)
2122 		goto done;
2123 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2124 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2125 			 "running e2fsck is recommended");
2126 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2127 		ext4_msg(sb, KERN_WARNING,
2128 			 "warning: mounting fs with errors, "
2129 			 "running e2fsck is recommended");
2130 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2131 		 le16_to_cpu(es->s_mnt_count) >=
2132 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2133 		ext4_msg(sb, KERN_WARNING,
2134 			 "warning: maximal mount count reached, "
2135 			 "running e2fsck is recommended");
2136 	else if (le32_to_cpu(es->s_checkinterval) &&
2137 		(le32_to_cpu(es->s_lastcheck) +
2138 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2139 		ext4_msg(sb, KERN_WARNING,
2140 			 "warning: checktime reached, "
2141 			 "running e2fsck is recommended");
2142 	if (!sbi->s_journal)
2143 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2144 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2145 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2146 	le16_add_cpu(&es->s_mnt_count, 1);
2147 	es->s_mtime = cpu_to_le32(get_seconds());
2148 	ext4_update_dynamic_rev(sb);
2149 	if (sbi->s_journal)
2150 		ext4_set_feature_journal_needs_recovery(sb);
2151 
2152 	ext4_commit_super(sb, 1);
2153 done:
2154 	if (test_opt(sb, DEBUG))
2155 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2156 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2157 			sb->s_blocksize,
2158 			sbi->s_groups_count,
2159 			EXT4_BLOCKS_PER_GROUP(sb),
2160 			EXT4_INODES_PER_GROUP(sb),
2161 			sbi->s_mount_opt, sbi->s_mount_opt2);
2162 
2163 	cleancache_init_fs(sb);
2164 	return res;
2165 }
2166 
2167 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2168 {
2169 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2170 	struct flex_groups *new_groups;
2171 	int size;
2172 
2173 	if (!sbi->s_log_groups_per_flex)
2174 		return 0;
2175 
2176 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2177 	if (size <= sbi->s_flex_groups_allocated)
2178 		return 0;
2179 
2180 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2181 	new_groups = kvzalloc(size, GFP_KERNEL);
2182 	if (!new_groups) {
2183 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2184 			 size / (int) sizeof(struct flex_groups));
2185 		return -ENOMEM;
2186 	}
2187 
2188 	if (sbi->s_flex_groups) {
2189 		memcpy(new_groups, sbi->s_flex_groups,
2190 		       (sbi->s_flex_groups_allocated *
2191 			sizeof(struct flex_groups)));
2192 		kvfree(sbi->s_flex_groups);
2193 	}
2194 	sbi->s_flex_groups = new_groups;
2195 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2196 	return 0;
2197 }
2198 
2199 static int ext4_fill_flex_info(struct super_block *sb)
2200 {
2201 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2202 	struct ext4_group_desc *gdp = NULL;
2203 	ext4_group_t flex_group;
2204 	int i, err;
2205 
2206 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2207 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2208 		sbi->s_log_groups_per_flex = 0;
2209 		return 1;
2210 	}
2211 
2212 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2213 	if (err)
2214 		goto failed;
2215 
2216 	for (i = 0; i < sbi->s_groups_count; i++) {
2217 		gdp = ext4_get_group_desc(sb, i, NULL);
2218 
2219 		flex_group = ext4_flex_group(sbi, i);
2220 		atomic_add(ext4_free_inodes_count(sb, gdp),
2221 			   &sbi->s_flex_groups[flex_group].free_inodes);
2222 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2223 			     &sbi->s_flex_groups[flex_group].free_clusters);
2224 		atomic_add(ext4_used_dirs_count(sb, gdp),
2225 			   &sbi->s_flex_groups[flex_group].used_dirs);
2226 	}
2227 
2228 	return 1;
2229 failed:
2230 	return 0;
2231 }
2232 
2233 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2234 				   struct ext4_group_desc *gdp)
2235 {
2236 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2237 	__u16 crc = 0;
2238 	__le32 le_group = cpu_to_le32(block_group);
2239 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2240 
2241 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2242 		/* Use new metadata_csum algorithm */
2243 		__u32 csum32;
2244 		__u16 dummy_csum = 0;
2245 
2246 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2247 				     sizeof(le_group));
2248 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2249 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2250 				     sizeof(dummy_csum));
2251 		offset += sizeof(dummy_csum);
2252 		if (offset < sbi->s_desc_size)
2253 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2254 					     sbi->s_desc_size - offset);
2255 
2256 		crc = csum32 & 0xFFFF;
2257 		goto out;
2258 	}
2259 
2260 	/* old crc16 code */
2261 	if (!ext4_has_feature_gdt_csum(sb))
2262 		return 0;
2263 
2264 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2265 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2266 	crc = crc16(crc, (__u8 *)gdp, offset);
2267 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2268 	/* for checksum of struct ext4_group_desc do the rest...*/
2269 	if (ext4_has_feature_64bit(sb) &&
2270 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2271 		crc = crc16(crc, (__u8 *)gdp + offset,
2272 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2273 				offset);
2274 
2275 out:
2276 	return cpu_to_le16(crc);
2277 }
2278 
2279 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2280 				struct ext4_group_desc *gdp)
2281 {
2282 	if (ext4_has_group_desc_csum(sb) &&
2283 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2284 		return 0;
2285 
2286 	return 1;
2287 }
2288 
2289 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2290 			      struct ext4_group_desc *gdp)
2291 {
2292 	if (!ext4_has_group_desc_csum(sb))
2293 		return;
2294 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2295 }
2296 
2297 /* Called at mount-time, super-block is locked */
2298 static int ext4_check_descriptors(struct super_block *sb,
2299 				  ext4_fsblk_t sb_block,
2300 				  ext4_group_t *first_not_zeroed)
2301 {
2302 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2303 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2304 	ext4_fsblk_t last_block;
2305 	ext4_fsblk_t block_bitmap;
2306 	ext4_fsblk_t inode_bitmap;
2307 	ext4_fsblk_t inode_table;
2308 	int flexbg_flag = 0;
2309 	ext4_group_t i, grp = sbi->s_groups_count;
2310 
2311 	if (ext4_has_feature_flex_bg(sb))
2312 		flexbg_flag = 1;
2313 
2314 	ext4_debug("Checking group descriptors");
2315 
2316 	for (i = 0; i < sbi->s_groups_count; i++) {
2317 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2318 
2319 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2320 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2321 		else
2322 			last_block = first_block +
2323 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2324 
2325 		if ((grp == sbi->s_groups_count) &&
2326 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2327 			grp = i;
2328 
2329 		block_bitmap = ext4_block_bitmap(sb, gdp);
2330 		if (block_bitmap == sb_block) {
2331 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2332 				 "Block bitmap for group %u overlaps "
2333 				 "superblock", i);
2334 		}
2335 		if (block_bitmap < first_block || block_bitmap > last_block) {
2336 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2337 			       "Block bitmap for group %u not in group "
2338 			       "(block %llu)!", i, block_bitmap);
2339 			return 0;
2340 		}
2341 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2342 		if (inode_bitmap == sb_block) {
2343 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2344 				 "Inode bitmap for group %u overlaps "
2345 				 "superblock", i);
2346 		}
2347 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2348 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2349 			       "Inode bitmap for group %u not in group "
2350 			       "(block %llu)!", i, inode_bitmap);
2351 			return 0;
2352 		}
2353 		inode_table = ext4_inode_table(sb, gdp);
2354 		if (inode_table == sb_block) {
2355 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2356 				 "Inode table for group %u overlaps "
2357 				 "superblock", i);
2358 		}
2359 		if (inode_table < first_block ||
2360 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2361 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2362 			       "Inode table for group %u not in group "
2363 			       "(block %llu)!", i, inode_table);
2364 			return 0;
2365 		}
2366 		ext4_lock_group(sb, i);
2367 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2368 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2369 				 "Checksum for group %u failed (%u!=%u)",
2370 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2371 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2372 			if (!sb_rdonly(sb)) {
2373 				ext4_unlock_group(sb, i);
2374 				return 0;
2375 			}
2376 		}
2377 		ext4_unlock_group(sb, i);
2378 		if (!flexbg_flag)
2379 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2380 	}
2381 	if (NULL != first_not_zeroed)
2382 		*first_not_zeroed = grp;
2383 	return 1;
2384 }
2385 
2386 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2387  * the superblock) which were deleted from all directories, but held open by
2388  * a process at the time of a crash.  We walk the list and try to delete these
2389  * inodes at recovery time (only with a read-write filesystem).
2390  *
2391  * In order to keep the orphan inode chain consistent during traversal (in
2392  * case of crash during recovery), we link each inode into the superblock
2393  * orphan list_head and handle it the same way as an inode deletion during
2394  * normal operation (which journals the operations for us).
2395  *
2396  * We only do an iget() and an iput() on each inode, which is very safe if we
2397  * accidentally point at an in-use or already deleted inode.  The worst that
2398  * can happen in this case is that we get a "bit already cleared" message from
2399  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2400  * e2fsck was run on this filesystem, and it must have already done the orphan
2401  * inode cleanup for us, so we can safely abort without any further action.
2402  */
2403 static void ext4_orphan_cleanup(struct super_block *sb,
2404 				struct ext4_super_block *es)
2405 {
2406 	unsigned int s_flags = sb->s_flags;
2407 	int ret, nr_orphans = 0, nr_truncates = 0;
2408 #ifdef CONFIG_QUOTA
2409 	int quota_update = 0;
2410 	int i;
2411 #endif
2412 	if (!es->s_last_orphan) {
2413 		jbd_debug(4, "no orphan inodes to clean up\n");
2414 		return;
2415 	}
2416 
2417 	if (bdev_read_only(sb->s_bdev)) {
2418 		ext4_msg(sb, KERN_ERR, "write access "
2419 			"unavailable, skipping orphan cleanup");
2420 		return;
2421 	}
2422 
2423 	/* Check if feature set would not allow a r/w mount */
2424 	if (!ext4_feature_set_ok(sb, 0)) {
2425 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2426 			 "unknown ROCOMPAT features");
2427 		return;
2428 	}
2429 
2430 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2431 		/* don't clear list on RO mount w/ errors */
2432 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2433 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2434 				  "clearing orphan list.\n");
2435 			es->s_last_orphan = 0;
2436 		}
2437 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2438 		return;
2439 	}
2440 
2441 	if (s_flags & SB_RDONLY) {
2442 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2443 		sb->s_flags &= ~SB_RDONLY;
2444 	}
2445 #ifdef CONFIG_QUOTA
2446 	/* Needed for iput() to work correctly and not trash data */
2447 	sb->s_flags |= SB_ACTIVE;
2448 
2449 	/*
2450 	 * Turn on quotas which were not enabled for read-only mounts if
2451 	 * filesystem has quota feature, so that they are updated correctly.
2452 	 */
2453 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2454 		int ret = ext4_enable_quotas(sb);
2455 
2456 		if (!ret)
2457 			quota_update = 1;
2458 		else
2459 			ext4_msg(sb, KERN_ERR,
2460 				"Cannot turn on quotas: error %d", ret);
2461 	}
2462 
2463 	/* Turn on journaled quotas used for old sytle */
2464 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2465 		if (EXT4_SB(sb)->s_qf_names[i]) {
2466 			int ret = ext4_quota_on_mount(sb, i);
2467 
2468 			if (!ret)
2469 				quota_update = 1;
2470 			else
2471 				ext4_msg(sb, KERN_ERR,
2472 					"Cannot turn on journaled "
2473 					"quota: type %d: error %d", i, ret);
2474 		}
2475 	}
2476 #endif
2477 
2478 	while (es->s_last_orphan) {
2479 		struct inode *inode;
2480 
2481 		/*
2482 		 * We may have encountered an error during cleanup; if
2483 		 * so, skip the rest.
2484 		 */
2485 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2486 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2487 			es->s_last_orphan = 0;
2488 			break;
2489 		}
2490 
2491 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2492 		if (IS_ERR(inode)) {
2493 			es->s_last_orphan = 0;
2494 			break;
2495 		}
2496 
2497 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2498 		dquot_initialize(inode);
2499 		if (inode->i_nlink) {
2500 			if (test_opt(sb, DEBUG))
2501 				ext4_msg(sb, KERN_DEBUG,
2502 					"%s: truncating inode %lu to %lld bytes",
2503 					__func__, inode->i_ino, inode->i_size);
2504 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2505 				  inode->i_ino, inode->i_size);
2506 			inode_lock(inode);
2507 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2508 			ret = ext4_truncate(inode);
2509 			if (ret)
2510 				ext4_std_error(inode->i_sb, ret);
2511 			inode_unlock(inode);
2512 			nr_truncates++;
2513 		} else {
2514 			if (test_opt(sb, DEBUG))
2515 				ext4_msg(sb, KERN_DEBUG,
2516 					"%s: deleting unreferenced inode %lu",
2517 					__func__, inode->i_ino);
2518 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2519 				  inode->i_ino);
2520 			nr_orphans++;
2521 		}
2522 		iput(inode);  /* The delete magic happens here! */
2523 	}
2524 
2525 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2526 
2527 	if (nr_orphans)
2528 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2529 		       PLURAL(nr_orphans));
2530 	if (nr_truncates)
2531 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2532 		       PLURAL(nr_truncates));
2533 #ifdef CONFIG_QUOTA
2534 	/* Turn off quotas if they were enabled for orphan cleanup */
2535 	if (quota_update) {
2536 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2537 			if (sb_dqopt(sb)->files[i])
2538 				dquot_quota_off(sb, i);
2539 		}
2540 	}
2541 #endif
2542 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2543 }
2544 
2545 /*
2546  * Maximal extent format file size.
2547  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2548  * extent format containers, within a sector_t, and within i_blocks
2549  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2550  * so that won't be a limiting factor.
2551  *
2552  * However there is other limiting factor. We do store extents in the form
2553  * of starting block and length, hence the resulting length of the extent
2554  * covering maximum file size must fit into on-disk format containers as
2555  * well. Given that length is always by 1 unit bigger than max unit (because
2556  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2557  *
2558  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2559  */
2560 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2561 {
2562 	loff_t res;
2563 	loff_t upper_limit = MAX_LFS_FILESIZE;
2564 
2565 	/* small i_blocks in vfs inode? */
2566 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2567 		/*
2568 		 * CONFIG_LBDAF is not enabled implies the inode
2569 		 * i_block represent total blocks in 512 bytes
2570 		 * 32 == size of vfs inode i_blocks * 8
2571 		 */
2572 		upper_limit = (1LL << 32) - 1;
2573 
2574 		/* total blocks in file system block size */
2575 		upper_limit >>= (blkbits - 9);
2576 		upper_limit <<= blkbits;
2577 	}
2578 
2579 	/*
2580 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2581 	 * by one fs block, so ee_len can cover the extent of maximum file
2582 	 * size
2583 	 */
2584 	res = (1LL << 32) - 1;
2585 	res <<= blkbits;
2586 
2587 	/* Sanity check against vm- & vfs- imposed limits */
2588 	if (res > upper_limit)
2589 		res = upper_limit;
2590 
2591 	return res;
2592 }
2593 
2594 /*
2595  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2596  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2597  * We need to be 1 filesystem block less than the 2^48 sector limit.
2598  */
2599 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2600 {
2601 	loff_t res = EXT4_NDIR_BLOCKS;
2602 	int meta_blocks;
2603 	loff_t upper_limit;
2604 	/* This is calculated to be the largest file size for a dense, block
2605 	 * mapped file such that the file's total number of 512-byte sectors,
2606 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2607 	 *
2608 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2609 	 * number of 512-byte sectors of the file.
2610 	 */
2611 
2612 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2613 		/*
2614 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2615 		 * the inode i_block field represents total file blocks in
2616 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2617 		 */
2618 		upper_limit = (1LL << 32) - 1;
2619 
2620 		/* total blocks in file system block size */
2621 		upper_limit >>= (bits - 9);
2622 
2623 	} else {
2624 		/*
2625 		 * We use 48 bit ext4_inode i_blocks
2626 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2627 		 * represent total number of blocks in
2628 		 * file system block size
2629 		 */
2630 		upper_limit = (1LL << 48) - 1;
2631 
2632 	}
2633 
2634 	/* indirect blocks */
2635 	meta_blocks = 1;
2636 	/* double indirect blocks */
2637 	meta_blocks += 1 + (1LL << (bits-2));
2638 	/* tripple indirect blocks */
2639 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2640 
2641 	upper_limit -= meta_blocks;
2642 	upper_limit <<= bits;
2643 
2644 	res += 1LL << (bits-2);
2645 	res += 1LL << (2*(bits-2));
2646 	res += 1LL << (3*(bits-2));
2647 	res <<= bits;
2648 	if (res > upper_limit)
2649 		res = upper_limit;
2650 
2651 	if (res > MAX_LFS_FILESIZE)
2652 		res = MAX_LFS_FILESIZE;
2653 
2654 	return res;
2655 }
2656 
2657 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2658 				   ext4_fsblk_t logical_sb_block, int nr)
2659 {
2660 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2661 	ext4_group_t bg, first_meta_bg;
2662 	int has_super = 0;
2663 
2664 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2665 
2666 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2667 		return logical_sb_block + nr + 1;
2668 	bg = sbi->s_desc_per_block * nr;
2669 	if (ext4_bg_has_super(sb, bg))
2670 		has_super = 1;
2671 
2672 	/*
2673 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2674 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2675 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2676 	 * compensate.
2677 	 */
2678 	if (sb->s_blocksize == 1024 && nr == 0 &&
2679 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2680 		has_super++;
2681 
2682 	return (has_super + ext4_group_first_block_no(sb, bg));
2683 }
2684 
2685 /**
2686  * ext4_get_stripe_size: Get the stripe size.
2687  * @sbi: In memory super block info
2688  *
2689  * If we have specified it via mount option, then
2690  * use the mount option value. If the value specified at mount time is
2691  * greater than the blocks per group use the super block value.
2692  * If the super block value is greater than blocks per group return 0.
2693  * Allocator needs it be less than blocks per group.
2694  *
2695  */
2696 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2697 {
2698 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2699 	unsigned long stripe_width =
2700 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2701 	int ret;
2702 
2703 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2704 		ret = sbi->s_stripe;
2705 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2706 		ret = stripe_width;
2707 	else if (stride && stride <= sbi->s_blocks_per_group)
2708 		ret = stride;
2709 	else
2710 		ret = 0;
2711 
2712 	/*
2713 	 * If the stripe width is 1, this makes no sense and
2714 	 * we set it to 0 to turn off stripe handling code.
2715 	 */
2716 	if (ret <= 1)
2717 		ret = 0;
2718 
2719 	return ret;
2720 }
2721 
2722 /*
2723  * Check whether this filesystem can be mounted based on
2724  * the features present and the RDONLY/RDWR mount requested.
2725  * Returns 1 if this filesystem can be mounted as requested,
2726  * 0 if it cannot be.
2727  */
2728 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2729 {
2730 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2731 		ext4_msg(sb, KERN_ERR,
2732 			"Couldn't mount because of "
2733 			"unsupported optional features (%x)",
2734 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2735 			~EXT4_FEATURE_INCOMPAT_SUPP));
2736 		return 0;
2737 	}
2738 
2739 	if (readonly)
2740 		return 1;
2741 
2742 	if (ext4_has_feature_readonly(sb)) {
2743 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2744 		sb->s_flags |= SB_RDONLY;
2745 		return 1;
2746 	}
2747 
2748 	/* Check that feature set is OK for a read-write mount */
2749 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2750 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2751 			 "unsupported optional features (%x)",
2752 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2753 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2754 		return 0;
2755 	}
2756 	/*
2757 	 * Large file size enabled file system can only be mounted
2758 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2759 	 */
2760 	if (ext4_has_feature_huge_file(sb)) {
2761 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2762 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2763 				 "cannot be mounted RDWR without "
2764 				 "CONFIG_LBDAF");
2765 			return 0;
2766 		}
2767 	}
2768 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2769 		ext4_msg(sb, KERN_ERR,
2770 			 "Can't support bigalloc feature without "
2771 			 "extents feature\n");
2772 		return 0;
2773 	}
2774 
2775 #ifndef CONFIG_QUOTA
2776 	if (ext4_has_feature_quota(sb) && !readonly) {
2777 		ext4_msg(sb, KERN_ERR,
2778 			 "Filesystem with quota feature cannot be mounted RDWR "
2779 			 "without CONFIG_QUOTA");
2780 		return 0;
2781 	}
2782 	if (ext4_has_feature_project(sb) && !readonly) {
2783 		ext4_msg(sb, KERN_ERR,
2784 			 "Filesystem with project quota feature cannot be mounted RDWR "
2785 			 "without CONFIG_QUOTA");
2786 		return 0;
2787 	}
2788 #endif  /* CONFIG_QUOTA */
2789 	return 1;
2790 }
2791 
2792 /*
2793  * This function is called once a day if we have errors logged
2794  * on the file system
2795  */
2796 static void print_daily_error_info(struct timer_list *t)
2797 {
2798 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2799 	struct super_block *sb = sbi->s_sb;
2800 	struct ext4_super_block *es = sbi->s_es;
2801 
2802 	if (es->s_error_count)
2803 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2804 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2805 			 le32_to_cpu(es->s_error_count));
2806 	if (es->s_first_error_time) {
2807 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2808 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2809 		       (int) sizeof(es->s_first_error_func),
2810 		       es->s_first_error_func,
2811 		       le32_to_cpu(es->s_first_error_line));
2812 		if (es->s_first_error_ino)
2813 			printk(KERN_CONT ": inode %u",
2814 			       le32_to_cpu(es->s_first_error_ino));
2815 		if (es->s_first_error_block)
2816 			printk(KERN_CONT ": block %llu", (unsigned long long)
2817 			       le64_to_cpu(es->s_first_error_block));
2818 		printk(KERN_CONT "\n");
2819 	}
2820 	if (es->s_last_error_time) {
2821 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2822 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2823 		       (int) sizeof(es->s_last_error_func),
2824 		       es->s_last_error_func,
2825 		       le32_to_cpu(es->s_last_error_line));
2826 		if (es->s_last_error_ino)
2827 			printk(KERN_CONT ": inode %u",
2828 			       le32_to_cpu(es->s_last_error_ino));
2829 		if (es->s_last_error_block)
2830 			printk(KERN_CONT ": block %llu", (unsigned long long)
2831 			       le64_to_cpu(es->s_last_error_block));
2832 		printk(KERN_CONT "\n");
2833 	}
2834 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2835 }
2836 
2837 /* Find next suitable group and run ext4_init_inode_table */
2838 static int ext4_run_li_request(struct ext4_li_request *elr)
2839 {
2840 	struct ext4_group_desc *gdp = NULL;
2841 	ext4_group_t group, ngroups;
2842 	struct super_block *sb;
2843 	unsigned long timeout = 0;
2844 	int ret = 0;
2845 
2846 	sb = elr->lr_super;
2847 	ngroups = EXT4_SB(sb)->s_groups_count;
2848 
2849 	for (group = elr->lr_next_group; group < ngroups; group++) {
2850 		gdp = ext4_get_group_desc(sb, group, NULL);
2851 		if (!gdp) {
2852 			ret = 1;
2853 			break;
2854 		}
2855 
2856 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2857 			break;
2858 	}
2859 
2860 	if (group >= ngroups)
2861 		ret = 1;
2862 
2863 	if (!ret) {
2864 		timeout = jiffies;
2865 		ret = ext4_init_inode_table(sb, group,
2866 					    elr->lr_timeout ? 0 : 1);
2867 		if (elr->lr_timeout == 0) {
2868 			timeout = (jiffies - timeout) *
2869 				  elr->lr_sbi->s_li_wait_mult;
2870 			elr->lr_timeout = timeout;
2871 		}
2872 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2873 		elr->lr_next_group = group + 1;
2874 	}
2875 	return ret;
2876 }
2877 
2878 /*
2879  * Remove lr_request from the list_request and free the
2880  * request structure. Should be called with li_list_mtx held
2881  */
2882 static void ext4_remove_li_request(struct ext4_li_request *elr)
2883 {
2884 	struct ext4_sb_info *sbi;
2885 
2886 	if (!elr)
2887 		return;
2888 
2889 	sbi = elr->lr_sbi;
2890 
2891 	list_del(&elr->lr_request);
2892 	sbi->s_li_request = NULL;
2893 	kfree(elr);
2894 }
2895 
2896 static void ext4_unregister_li_request(struct super_block *sb)
2897 {
2898 	mutex_lock(&ext4_li_mtx);
2899 	if (!ext4_li_info) {
2900 		mutex_unlock(&ext4_li_mtx);
2901 		return;
2902 	}
2903 
2904 	mutex_lock(&ext4_li_info->li_list_mtx);
2905 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2906 	mutex_unlock(&ext4_li_info->li_list_mtx);
2907 	mutex_unlock(&ext4_li_mtx);
2908 }
2909 
2910 static struct task_struct *ext4_lazyinit_task;
2911 
2912 /*
2913  * This is the function where ext4lazyinit thread lives. It walks
2914  * through the request list searching for next scheduled filesystem.
2915  * When such a fs is found, run the lazy initialization request
2916  * (ext4_rn_li_request) and keep track of the time spend in this
2917  * function. Based on that time we compute next schedule time of
2918  * the request. When walking through the list is complete, compute
2919  * next waking time and put itself into sleep.
2920  */
2921 static int ext4_lazyinit_thread(void *arg)
2922 {
2923 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2924 	struct list_head *pos, *n;
2925 	struct ext4_li_request *elr;
2926 	unsigned long next_wakeup, cur;
2927 
2928 	BUG_ON(NULL == eli);
2929 
2930 cont_thread:
2931 	while (true) {
2932 		next_wakeup = MAX_JIFFY_OFFSET;
2933 
2934 		mutex_lock(&eli->li_list_mtx);
2935 		if (list_empty(&eli->li_request_list)) {
2936 			mutex_unlock(&eli->li_list_mtx);
2937 			goto exit_thread;
2938 		}
2939 		list_for_each_safe(pos, n, &eli->li_request_list) {
2940 			int err = 0;
2941 			int progress = 0;
2942 			elr = list_entry(pos, struct ext4_li_request,
2943 					 lr_request);
2944 
2945 			if (time_before(jiffies, elr->lr_next_sched)) {
2946 				if (time_before(elr->lr_next_sched, next_wakeup))
2947 					next_wakeup = elr->lr_next_sched;
2948 				continue;
2949 			}
2950 			if (down_read_trylock(&elr->lr_super->s_umount)) {
2951 				if (sb_start_write_trylock(elr->lr_super)) {
2952 					progress = 1;
2953 					/*
2954 					 * We hold sb->s_umount, sb can not
2955 					 * be removed from the list, it is
2956 					 * now safe to drop li_list_mtx
2957 					 */
2958 					mutex_unlock(&eli->li_list_mtx);
2959 					err = ext4_run_li_request(elr);
2960 					sb_end_write(elr->lr_super);
2961 					mutex_lock(&eli->li_list_mtx);
2962 					n = pos->next;
2963 				}
2964 				up_read((&elr->lr_super->s_umount));
2965 			}
2966 			/* error, remove the lazy_init job */
2967 			if (err) {
2968 				ext4_remove_li_request(elr);
2969 				continue;
2970 			}
2971 			if (!progress) {
2972 				elr->lr_next_sched = jiffies +
2973 					(prandom_u32()
2974 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2975 			}
2976 			if (time_before(elr->lr_next_sched, next_wakeup))
2977 				next_wakeup = elr->lr_next_sched;
2978 		}
2979 		mutex_unlock(&eli->li_list_mtx);
2980 
2981 		try_to_freeze();
2982 
2983 		cur = jiffies;
2984 		if ((time_after_eq(cur, next_wakeup)) ||
2985 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2986 			cond_resched();
2987 			continue;
2988 		}
2989 
2990 		schedule_timeout_interruptible(next_wakeup - cur);
2991 
2992 		if (kthread_should_stop()) {
2993 			ext4_clear_request_list();
2994 			goto exit_thread;
2995 		}
2996 	}
2997 
2998 exit_thread:
2999 	/*
3000 	 * It looks like the request list is empty, but we need
3001 	 * to check it under the li_list_mtx lock, to prevent any
3002 	 * additions into it, and of course we should lock ext4_li_mtx
3003 	 * to atomically free the list and ext4_li_info, because at
3004 	 * this point another ext4 filesystem could be registering
3005 	 * new one.
3006 	 */
3007 	mutex_lock(&ext4_li_mtx);
3008 	mutex_lock(&eli->li_list_mtx);
3009 	if (!list_empty(&eli->li_request_list)) {
3010 		mutex_unlock(&eli->li_list_mtx);
3011 		mutex_unlock(&ext4_li_mtx);
3012 		goto cont_thread;
3013 	}
3014 	mutex_unlock(&eli->li_list_mtx);
3015 	kfree(ext4_li_info);
3016 	ext4_li_info = NULL;
3017 	mutex_unlock(&ext4_li_mtx);
3018 
3019 	return 0;
3020 }
3021 
3022 static void ext4_clear_request_list(void)
3023 {
3024 	struct list_head *pos, *n;
3025 	struct ext4_li_request *elr;
3026 
3027 	mutex_lock(&ext4_li_info->li_list_mtx);
3028 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3029 		elr = list_entry(pos, struct ext4_li_request,
3030 				 lr_request);
3031 		ext4_remove_li_request(elr);
3032 	}
3033 	mutex_unlock(&ext4_li_info->li_list_mtx);
3034 }
3035 
3036 static int ext4_run_lazyinit_thread(void)
3037 {
3038 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3039 					 ext4_li_info, "ext4lazyinit");
3040 	if (IS_ERR(ext4_lazyinit_task)) {
3041 		int err = PTR_ERR(ext4_lazyinit_task);
3042 		ext4_clear_request_list();
3043 		kfree(ext4_li_info);
3044 		ext4_li_info = NULL;
3045 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3046 				 "initialization thread\n",
3047 				 err);
3048 		return err;
3049 	}
3050 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3051 	return 0;
3052 }
3053 
3054 /*
3055  * Check whether it make sense to run itable init. thread or not.
3056  * If there is at least one uninitialized inode table, return
3057  * corresponding group number, else the loop goes through all
3058  * groups and return total number of groups.
3059  */
3060 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3061 {
3062 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3063 	struct ext4_group_desc *gdp = NULL;
3064 
3065 	for (group = 0; group < ngroups; group++) {
3066 		gdp = ext4_get_group_desc(sb, group, NULL);
3067 		if (!gdp)
3068 			continue;
3069 
3070 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3071 			break;
3072 	}
3073 
3074 	return group;
3075 }
3076 
3077 static int ext4_li_info_new(void)
3078 {
3079 	struct ext4_lazy_init *eli = NULL;
3080 
3081 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3082 	if (!eli)
3083 		return -ENOMEM;
3084 
3085 	INIT_LIST_HEAD(&eli->li_request_list);
3086 	mutex_init(&eli->li_list_mtx);
3087 
3088 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3089 
3090 	ext4_li_info = eli;
3091 
3092 	return 0;
3093 }
3094 
3095 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3096 					    ext4_group_t start)
3097 {
3098 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3099 	struct ext4_li_request *elr;
3100 
3101 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3102 	if (!elr)
3103 		return NULL;
3104 
3105 	elr->lr_super = sb;
3106 	elr->lr_sbi = sbi;
3107 	elr->lr_next_group = start;
3108 
3109 	/*
3110 	 * Randomize first schedule time of the request to
3111 	 * spread the inode table initialization requests
3112 	 * better.
3113 	 */
3114 	elr->lr_next_sched = jiffies + (prandom_u32() %
3115 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3116 	return elr;
3117 }
3118 
3119 int ext4_register_li_request(struct super_block *sb,
3120 			     ext4_group_t first_not_zeroed)
3121 {
3122 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3123 	struct ext4_li_request *elr = NULL;
3124 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3125 	int ret = 0;
3126 
3127 	mutex_lock(&ext4_li_mtx);
3128 	if (sbi->s_li_request != NULL) {
3129 		/*
3130 		 * Reset timeout so it can be computed again, because
3131 		 * s_li_wait_mult might have changed.
3132 		 */
3133 		sbi->s_li_request->lr_timeout = 0;
3134 		goto out;
3135 	}
3136 
3137 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3138 	    !test_opt(sb, INIT_INODE_TABLE))
3139 		goto out;
3140 
3141 	elr = ext4_li_request_new(sb, first_not_zeroed);
3142 	if (!elr) {
3143 		ret = -ENOMEM;
3144 		goto out;
3145 	}
3146 
3147 	if (NULL == ext4_li_info) {
3148 		ret = ext4_li_info_new();
3149 		if (ret)
3150 			goto out;
3151 	}
3152 
3153 	mutex_lock(&ext4_li_info->li_list_mtx);
3154 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3155 	mutex_unlock(&ext4_li_info->li_list_mtx);
3156 
3157 	sbi->s_li_request = elr;
3158 	/*
3159 	 * set elr to NULL here since it has been inserted to
3160 	 * the request_list and the removal and free of it is
3161 	 * handled by ext4_clear_request_list from now on.
3162 	 */
3163 	elr = NULL;
3164 
3165 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3166 		ret = ext4_run_lazyinit_thread();
3167 		if (ret)
3168 			goto out;
3169 	}
3170 out:
3171 	mutex_unlock(&ext4_li_mtx);
3172 	if (ret)
3173 		kfree(elr);
3174 	return ret;
3175 }
3176 
3177 /*
3178  * We do not need to lock anything since this is called on
3179  * module unload.
3180  */
3181 static void ext4_destroy_lazyinit_thread(void)
3182 {
3183 	/*
3184 	 * If thread exited earlier
3185 	 * there's nothing to be done.
3186 	 */
3187 	if (!ext4_li_info || !ext4_lazyinit_task)
3188 		return;
3189 
3190 	kthread_stop(ext4_lazyinit_task);
3191 }
3192 
3193 static int set_journal_csum_feature_set(struct super_block *sb)
3194 {
3195 	int ret = 1;
3196 	int compat, incompat;
3197 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3198 
3199 	if (ext4_has_metadata_csum(sb)) {
3200 		/* journal checksum v3 */
3201 		compat = 0;
3202 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3203 	} else {
3204 		/* journal checksum v1 */
3205 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3206 		incompat = 0;
3207 	}
3208 
3209 	jbd2_journal_clear_features(sbi->s_journal,
3210 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3211 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3212 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3213 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3214 		ret = jbd2_journal_set_features(sbi->s_journal,
3215 				compat, 0,
3216 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3217 				incompat);
3218 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3219 		ret = jbd2_journal_set_features(sbi->s_journal,
3220 				compat, 0,
3221 				incompat);
3222 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3223 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3224 	} else {
3225 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3226 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3227 	}
3228 
3229 	return ret;
3230 }
3231 
3232 /*
3233  * Note: calculating the overhead so we can be compatible with
3234  * historical BSD practice is quite difficult in the face of
3235  * clusters/bigalloc.  This is because multiple metadata blocks from
3236  * different block group can end up in the same allocation cluster.
3237  * Calculating the exact overhead in the face of clustered allocation
3238  * requires either O(all block bitmaps) in memory or O(number of block
3239  * groups**2) in time.  We will still calculate the superblock for
3240  * older file systems --- and if we come across with a bigalloc file
3241  * system with zero in s_overhead_clusters the estimate will be close to
3242  * correct especially for very large cluster sizes --- but for newer
3243  * file systems, it's better to calculate this figure once at mkfs
3244  * time, and store it in the superblock.  If the superblock value is
3245  * present (even for non-bigalloc file systems), we will use it.
3246  */
3247 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3248 			  char *buf)
3249 {
3250 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3251 	struct ext4_group_desc	*gdp;
3252 	ext4_fsblk_t		first_block, last_block, b;
3253 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3254 	int			s, j, count = 0;
3255 
3256 	if (!ext4_has_feature_bigalloc(sb))
3257 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3258 			sbi->s_itb_per_group + 2);
3259 
3260 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3261 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3262 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3263 	for (i = 0; i < ngroups; i++) {
3264 		gdp = ext4_get_group_desc(sb, i, NULL);
3265 		b = ext4_block_bitmap(sb, gdp);
3266 		if (b >= first_block && b <= last_block) {
3267 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3268 			count++;
3269 		}
3270 		b = ext4_inode_bitmap(sb, gdp);
3271 		if (b >= first_block && b <= last_block) {
3272 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3273 			count++;
3274 		}
3275 		b = ext4_inode_table(sb, gdp);
3276 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3277 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3278 				int c = EXT4_B2C(sbi, b - first_block);
3279 				ext4_set_bit(c, buf);
3280 				count++;
3281 			}
3282 		if (i != grp)
3283 			continue;
3284 		s = 0;
3285 		if (ext4_bg_has_super(sb, grp)) {
3286 			ext4_set_bit(s++, buf);
3287 			count++;
3288 		}
3289 		j = ext4_bg_num_gdb(sb, grp);
3290 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3291 			ext4_error(sb, "Invalid number of block group "
3292 				   "descriptor blocks: %d", j);
3293 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3294 		}
3295 		count += j;
3296 		for (; j > 0; j--)
3297 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3298 	}
3299 	if (!count)
3300 		return 0;
3301 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3302 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3303 }
3304 
3305 /*
3306  * Compute the overhead and stash it in sbi->s_overhead
3307  */
3308 int ext4_calculate_overhead(struct super_block *sb)
3309 {
3310 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3311 	struct ext4_super_block *es = sbi->s_es;
3312 	struct inode *j_inode;
3313 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3314 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3315 	ext4_fsblk_t overhead = 0;
3316 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3317 
3318 	if (!buf)
3319 		return -ENOMEM;
3320 
3321 	/*
3322 	 * Compute the overhead (FS structures).  This is constant
3323 	 * for a given filesystem unless the number of block groups
3324 	 * changes so we cache the previous value until it does.
3325 	 */
3326 
3327 	/*
3328 	 * All of the blocks before first_data_block are overhead
3329 	 */
3330 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3331 
3332 	/*
3333 	 * Add the overhead found in each block group
3334 	 */
3335 	for (i = 0; i < ngroups; i++) {
3336 		int blks;
3337 
3338 		blks = count_overhead(sb, i, buf);
3339 		overhead += blks;
3340 		if (blks)
3341 			memset(buf, 0, PAGE_SIZE);
3342 		cond_resched();
3343 	}
3344 
3345 	/*
3346 	 * Add the internal journal blocks whether the journal has been
3347 	 * loaded or not
3348 	 */
3349 	if (sbi->s_journal && !sbi->journal_bdev)
3350 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3351 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3352 		j_inode = ext4_get_journal_inode(sb, j_inum);
3353 		if (j_inode) {
3354 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3355 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3356 			iput(j_inode);
3357 		} else {
3358 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3359 		}
3360 	}
3361 	sbi->s_overhead = overhead;
3362 	smp_wmb();
3363 	free_page((unsigned long) buf);
3364 	return 0;
3365 }
3366 
3367 static void ext4_set_resv_clusters(struct super_block *sb)
3368 {
3369 	ext4_fsblk_t resv_clusters;
3370 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3371 
3372 	/*
3373 	 * There's no need to reserve anything when we aren't using extents.
3374 	 * The space estimates are exact, there are no unwritten extents,
3375 	 * hole punching doesn't need new metadata... This is needed especially
3376 	 * to keep ext2/3 backward compatibility.
3377 	 */
3378 	if (!ext4_has_feature_extents(sb))
3379 		return;
3380 	/*
3381 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3382 	 * This should cover the situations where we can not afford to run
3383 	 * out of space like for example punch hole, or converting
3384 	 * unwritten extents in delalloc path. In most cases such
3385 	 * allocation would require 1, or 2 blocks, higher numbers are
3386 	 * very rare.
3387 	 */
3388 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3389 			 sbi->s_cluster_bits);
3390 
3391 	do_div(resv_clusters, 50);
3392 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3393 
3394 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3395 }
3396 
3397 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3398 {
3399 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3400 	char *orig_data = kstrdup(data, GFP_KERNEL);
3401 	struct buffer_head *bh;
3402 	struct ext4_super_block *es = NULL;
3403 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3404 	ext4_fsblk_t block;
3405 	ext4_fsblk_t sb_block = get_sb_block(&data);
3406 	ext4_fsblk_t logical_sb_block;
3407 	unsigned long offset = 0;
3408 	unsigned long journal_devnum = 0;
3409 	unsigned long def_mount_opts;
3410 	struct inode *root;
3411 	const char *descr;
3412 	int ret = -ENOMEM;
3413 	int blocksize, clustersize;
3414 	unsigned int db_count;
3415 	unsigned int i;
3416 	int needs_recovery, has_huge_files, has_bigalloc;
3417 	__u64 blocks_count;
3418 	int err = 0;
3419 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3420 	ext4_group_t first_not_zeroed;
3421 
3422 	if ((data && !orig_data) || !sbi)
3423 		goto out_free_base;
3424 
3425 	sbi->s_daxdev = dax_dev;
3426 	sbi->s_blockgroup_lock =
3427 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3428 	if (!sbi->s_blockgroup_lock)
3429 		goto out_free_base;
3430 
3431 	sb->s_fs_info = sbi;
3432 	sbi->s_sb = sb;
3433 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3434 	sbi->s_sb_block = sb_block;
3435 	if (sb->s_bdev->bd_part)
3436 		sbi->s_sectors_written_start =
3437 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3438 
3439 	/* Cleanup superblock name */
3440 	strreplace(sb->s_id, '/', '!');
3441 
3442 	/* -EINVAL is default */
3443 	ret = -EINVAL;
3444 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3445 	if (!blocksize) {
3446 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3447 		goto out_fail;
3448 	}
3449 
3450 	/*
3451 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3452 	 * block sizes.  We need to calculate the offset from buffer start.
3453 	 */
3454 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3455 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3456 		offset = do_div(logical_sb_block, blocksize);
3457 	} else {
3458 		logical_sb_block = sb_block;
3459 	}
3460 
3461 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3462 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3463 		goto out_fail;
3464 	}
3465 	/*
3466 	 * Note: s_es must be initialized as soon as possible because
3467 	 *       some ext4 macro-instructions depend on its value
3468 	 */
3469 	es = (struct ext4_super_block *) (bh->b_data + offset);
3470 	sbi->s_es = es;
3471 	sb->s_magic = le16_to_cpu(es->s_magic);
3472 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3473 		goto cantfind_ext4;
3474 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3475 
3476 	/* Warn if metadata_csum and gdt_csum are both set. */
3477 	if (ext4_has_feature_metadata_csum(sb) &&
3478 	    ext4_has_feature_gdt_csum(sb))
3479 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3480 			     "redundant flags; please run fsck.");
3481 
3482 	/* Check for a known checksum algorithm */
3483 	if (!ext4_verify_csum_type(sb, es)) {
3484 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3485 			 "unknown checksum algorithm.");
3486 		silent = 1;
3487 		goto cantfind_ext4;
3488 	}
3489 
3490 	/* Load the checksum driver */
3491 	if (ext4_has_feature_metadata_csum(sb) ||
3492 	    ext4_has_feature_ea_inode(sb)) {
3493 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3494 		if (IS_ERR(sbi->s_chksum_driver)) {
3495 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3496 			ret = PTR_ERR(sbi->s_chksum_driver);
3497 			sbi->s_chksum_driver = NULL;
3498 			goto failed_mount;
3499 		}
3500 	}
3501 
3502 	/* Check superblock checksum */
3503 	if (!ext4_superblock_csum_verify(sb, es)) {
3504 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3505 			 "invalid superblock checksum.  Run e2fsck?");
3506 		silent = 1;
3507 		ret = -EFSBADCRC;
3508 		goto cantfind_ext4;
3509 	}
3510 
3511 	/* Precompute checksum seed for all metadata */
3512 	if (ext4_has_feature_csum_seed(sb))
3513 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3514 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3515 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3516 					       sizeof(es->s_uuid));
3517 
3518 	/* Set defaults before we parse the mount options */
3519 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3520 	set_opt(sb, INIT_INODE_TABLE);
3521 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3522 		set_opt(sb, DEBUG);
3523 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3524 		set_opt(sb, GRPID);
3525 	if (def_mount_opts & EXT4_DEFM_UID16)
3526 		set_opt(sb, NO_UID32);
3527 	/* xattr user namespace & acls are now defaulted on */
3528 	set_opt(sb, XATTR_USER);
3529 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3530 	set_opt(sb, POSIX_ACL);
3531 #endif
3532 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3533 	if (ext4_has_metadata_csum(sb))
3534 		set_opt(sb, JOURNAL_CHECKSUM);
3535 
3536 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3537 		set_opt(sb, JOURNAL_DATA);
3538 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3539 		set_opt(sb, ORDERED_DATA);
3540 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3541 		set_opt(sb, WRITEBACK_DATA);
3542 
3543 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3544 		set_opt(sb, ERRORS_PANIC);
3545 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3546 		set_opt(sb, ERRORS_CONT);
3547 	else
3548 		set_opt(sb, ERRORS_RO);
3549 	/* block_validity enabled by default; disable with noblock_validity */
3550 	set_opt(sb, BLOCK_VALIDITY);
3551 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3552 		set_opt(sb, DISCARD);
3553 
3554 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3555 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3556 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3557 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3558 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3559 
3560 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3561 		set_opt(sb, BARRIER);
3562 
3563 	/*
3564 	 * enable delayed allocation by default
3565 	 * Use -o nodelalloc to turn it off
3566 	 */
3567 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3568 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3569 		set_opt(sb, DELALLOC);
3570 
3571 	/*
3572 	 * set default s_li_wait_mult for lazyinit, for the case there is
3573 	 * no mount option specified.
3574 	 */
3575 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3576 
3577 	if (sbi->s_es->s_mount_opts[0]) {
3578 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3579 					      sizeof(sbi->s_es->s_mount_opts),
3580 					      GFP_KERNEL);
3581 		if (!s_mount_opts)
3582 			goto failed_mount;
3583 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3584 				   &journal_ioprio, 0)) {
3585 			ext4_msg(sb, KERN_WARNING,
3586 				 "failed to parse options in superblock: %s",
3587 				 s_mount_opts);
3588 		}
3589 		kfree(s_mount_opts);
3590 	}
3591 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3592 	if (!parse_options((char *) data, sb, &journal_devnum,
3593 			   &journal_ioprio, 0))
3594 		goto failed_mount;
3595 
3596 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3597 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3598 			    "with data=journal disables delayed "
3599 			    "allocation and O_DIRECT support!\n");
3600 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3601 			ext4_msg(sb, KERN_ERR, "can't mount with "
3602 				 "both data=journal and delalloc");
3603 			goto failed_mount;
3604 		}
3605 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3606 			ext4_msg(sb, KERN_ERR, "can't mount with "
3607 				 "both data=journal and dioread_nolock");
3608 			goto failed_mount;
3609 		}
3610 		if (test_opt(sb, DAX)) {
3611 			ext4_msg(sb, KERN_ERR, "can't mount with "
3612 				 "both data=journal and dax");
3613 			goto failed_mount;
3614 		}
3615 		if (ext4_has_feature_encrypt(sb)) {
3616 			ext4_msg(sb, KERN_WARNING,
3617 				 "encrypted files will use data=ordered "
3618 				 "instead of data journaling mode");
3619 		}
3620 		if (test_opt(sb, DELALLOC))
3621 			clear_opt(sb, DELALLOC);
3622 	} else {
3623 		sb->s_iflags |= SB_I_CGROUPWB;
3624 	}
3625 
3626 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3627 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3628 
3629 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3630 	    (ext4_has_compat_features(sb) ||
3631 	     ext4_has_ro_compat_features(sb) ||
3632 	     ext4_has_incompat_features(sb)))
3633 		ext4_msg(sb, KERN_WARNING,
3634 		       "feature flags set on rev 0 fs, "
3635 		       "running e2fsck is recommended");
3636 
3637 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3638 		set_opt2(sb, HURD_COMPAT);
3639 		if (ext4_has_feature_64bit(sb)) {
3640 			ext4_msg(sb, KERN_ERR,
3641 				 "The Hurd can't support 64-bit file systems");
3642 			goto failed_mount;
3643 		}
3644 
3645 		/*
3646 		 * ea_inode feature uses l_i_version field which is not
3647 		 * available in HURD_COMPAT mode.
3648 		 */
3649 		if (ext4_has_feature_ea_inode(sb)) {
3650 			ext4_msg(sb, KERN_ERR,
3651 				 "ea_inode feature is not supported for Hurd");
3652 			goto failed_mount;
3653 		}
3654 	}
3655 
3656 	if (IS_EXT2_SB(sb)) {
3657 		if (ext2_feature_set_ok(sb))
3658 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3659 				 "using the ext4 subsystem");
3660 		else {
3661 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3662 				 "to feature incompatibilities");
3663 			goto failed_mount;
3664 		}
3665 	}
3666 
3667 	if (IS_EXT3_SB(sb)) {
3668 		if (ext3_feature_set_ok(sb))
3669 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3670 				 "using the ext4 subsystem");
3671 		else {
3672 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3673 				 "to feature incompatibilities");
3674 			goto failed_mount;
3675 		}
3676 	}
3677 
3678 	/*
3679 	 * Check feature flags regardless of the revision level, since we
3680 	 * previously didn't change the revision level when setting the flags,
3681 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3682 	 */
3683 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3684 		goto failed_mount;
3685 
3686 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3687 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3688 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3689 		ext4_msg(sb, KERN_ERR,
3690 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3691 			 blocksize, le32_to_cpu(es->s_log_block_size));
3692 		goto failed_mount;
3693 	}
3694 	if (le32_to_cpu(es->s_log_block_size) >
3695 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3696 		ext4_msg(sb, KERN_ERR,
3697 			 "Invalid log block size: %u",
3698 			 le32_to_cpu(es->s_log_block_size));
3699 		goto failed_mount;
3700 	}
3701 
3702 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3703 		ext4_msg(sb, KERN_ERR,
3704 			 "Number of reserved GDT blocks insanely large: %d",
3705 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3706 		goto failed_mount;
3707 	}
3708 
3709 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3710 		if (ext4_has_feature_inline_data(sb)) {
3711 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3712 					" that may contain inline data");
3713 			goto failed_mount;
3714 		}
3715 		err = bdev_dax_supported(sb, blocksize);
3716 		if (err)
3717 			goto failed_mount;
3718 	}
3719 
3720 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3721 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3722 			 es->s_encryption_level);
3723 		goto failed_mount;
3724 	}
3725 
3726 	if (sb->s_blocksize != blocksize) {
3727 		/* Validate the filesystem blocksize */
3728 		if (!sb_set_blocksize(sb, blocksize)) {
3729 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3730 					blocksize);
3731 			goto failed_mount;
3732 		}
3733 
3734 		brelse(bh);
3735 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3736 		offset = do_div(logical_sb_block, blocksize);
3737 		bh = sb_bread_unmovable(sb, logical_sb_block);
3738 		if (!bh) {
3739 			ext4_msg(sb, KERN_ERR,
3740 			       "Can't read superblock on 2nd try");
3741 			goto failed_mount;
3742 		}
3743 		es = (struct ext4_super_block *)(bh->b_data + offset);
3744 		sbi->s_es = es;
3745 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3746 			ext4_msg(sb, KERN_ERR,
3747 			       "Magic mismatch, very weird!");
3748 			goto failed_mount;
3749 		}
3750 	}
3751 
3752 	has_huge_files = ext4_has_feature_huge_file(sb);
3753 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3754 						      has_huge_files);
3755 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3756 
3757 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3758 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3759 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3760 	} else {
3761 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3762 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3763 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3764 		    (!is_power_of_2(sbi->s_inode_size)) ||
3765 		    (sbi->s_inode_size > blocksize)) {
3766 			ext4_msg(sb, KERN_ERR,
3767 			       "unsupported inode size: %d",
3768 			       sbi->s_inode_size);
3769 			goto failed_mount;
3770 		}
3771 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3772 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3773 	}
3774 
3775 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3776 	if (ext4_has_feature_64bit(sb)) {
3777 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3778 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3779 		    !is_power_of_2(sbi->s_desc_size)) {
3780 			ext4_msg(sb, KERN_ERR,
3781 			       "unsupported descriptor size %lu",
3782 			       sbi->s_desc_size);
3783 			goto failed_mount;
3784 		}
3785 	} else
3786 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3787 
3788 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3789 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3790 
3791 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3792 	if (sbi->s_inodes_per_block == 0)
3793 		goto cantfind_ext4;
3794 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3795 	    sbi->s_inodes_per_group > blocksize * 8) {
3796 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3797 			 sbi->s_blocks_per_group);
3798 		goto failed_mount;
3799 	}
3800 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3801 					sbi->s_inodes_per_block;
3802 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3803 	sbi->s_sbh = bh;
3804 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3805 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3806 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3807 
3808 	for (i = 0; i < 4; i++)
3809 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3810 	sbi->s_def_hash_version = es->s_def_hash_version;
3811 	if (ext4_has_feature_dir_index(sb)) {
3812 		i = le32_to_cpu(es->s_flags);
3813 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3814 			sbi->s_hash_unsigned = 3;
3815 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3816 #ifdef __CHAR_UNSIGNED__
3817 			if (!sb_rdonly(sb))
3818 				es->s_flags |=
3819 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3820 			sbi->s_hash_unsigned = 3;
3821 #else
3822 			if (!sb_rdonly(sb))
3823 				es->s_flags |=
3824 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3825 #endif
3826 		}
3827 	}
3828 
3829 	/* Handle clustersize */
3830 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3831 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3832 	if (has_bigalloc) {
3833 		if (clustersize < blocksize) {
3834 			ext4_msg(sb, KERN_ERR,
3835 				 "cluster size (%d) smaller than "
3836 				 "block size (%d)", clustersize, blocksize);
3837 			goto failed_mount;
3838 		}
3839 		if (le32_to_cpu(es->s_log_cluster_size) >
3840 		    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3841 			ext4_msg(sb, KERN_ERR,
3842 				 "Invalid log cluster size: %u",
3843 				 le32_to_cpu(es->s_log_cluster_size));
3844 			goto failed_mount;
3845 		}
3846 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3847 			le32_to_cpu(es->s_log_block_size);
3848 		sbi->s_clusters_per_group =
3849 			le32_to_cpu(es->s_clusters_per_group);
3850 		if (sbi->s_clusters_per_group > blocksize * 8) {
3851 			ext4_msg(sb, KERN_ERR,
3852 				 "#clusters per group too big: %lu",
3853 				 sbi->s_clusters_per_group);
3854 			goto failed_mount;
3855 		}
3856 		if (sbi->s_blocks_per_group !=
3857 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3858 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3859 				 "clusters per group (%lu) inconsistent",
3860 				 sbi->s_blocks_per_group,
3861 				 sbi->s_clusters_per_group);
3862 			goto failed_mount;
3863 		}
3864 	} else {
3865 		if (clustersize != blocksize) {
3866 			ext4_warning(sb, "fragment/cluster size (%d) != "
3867 				     "block size (%d)", clustersize,
3868 				     blocksize);
3869 			clustersize = blocksize;
3870 		}
3871 		if (sbi->s_blocks_per_group > blocksize * 8) {
3872 			ext4_msg(sb, KERN_ERR,
3873 				 "#blocks per group too big: %lu",
3874 				 sbi->s_blocks_per_group);
3875 			goto failed_mount;
3876 		}
3877 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3878 		sbi->s_cluster_bits = 0;
3879 	}
3880 	sbi->s_cluster_ratio = clustersize / blocksize;
3881 
3882 	/* Do we have standard group size of clustersize * 8 blocks ? */
3883 	if (sbi->s_blocks_per_group == clustersize << 3)
3884 		set_opt2(sb, STD_GROUP_SIZE);
3885 
3886 	/*
3887 	 * Test whether we have more sectors than will fit in sector_t,
3888 	 * and whether the max offset is addressable by the page cache.
3889 	 */
3890 	err = generic_check_addressable(sb->s_blocksize_bits,
3891 					ext4_blocks_count(es));
3892 	if (err) {
3893 		ext4_msg(sb, KERN_ERR, "filesystem"
3894 			 " too large to mount safely on this system");
3895 		if (sizeof(sector_t) < 8)
3896 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3897 		goto failed_mount;
3898 	}
3899 
3900 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3901 		goto cantfind_ext4;
3902 
3903 	/* check blocks count against device size */
3904 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3905 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3906 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3907 		       "exceeds size of device (%llu blocks)",
3908 		       ext4_blocks_count(es), blocks_count);
3909 		goto failed_mount;
3910 	}
3911 
3912 	/*
3913 	 * It makes no sense for the first data block to be beyond the end
3914 	 * of the filesystem.
3915 	 */
3916 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3917 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3918 			 "block %u is beyond end of filesystem (%llu)",
3919 			 le32_to_cpu(es->s_first_data_block),
3920 			 ext4_blocks_count(es));
3921 		goto failed_mount;
3922 	}
3923 	blocks_count = (ext4_blocks_count(es) -
3924 			le32_to_cpu(es->s_first_data_block) +
3925 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3926 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3927 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3928 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3929 		       "(block count %llu, first data block %u, "
3930 		       "blocks per group %lu)", sbi->s_groups_count,
3931 		       ext4_blocks_count(es),
3932 		       le32_to_cpu(es->s_first_data_block),
3933 		       EXT4_BLOCKS_PER_GROUP(sb));
3934 		goto failed_mount;
3935 	}
3936 	sbi->s_groups_count = blocks_count;
3937 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3938 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3939 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3940 		   EXT4_DESC_PER_BLOCK(sb);
3941 	if (ext4_has_feature_meta_bg(sb)) {
3942 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3943 			ext4_msg(sb, KERN_WARNING,
3944 				 "first meta block group too large: %u "
3945 				 "(group descriptor block count %u)",
3946 				 le32_to_cpu(es->s_first_meta_bg), db_count);
3947 			goto failed_mount;
3948 		}
3949 	}
3950 	sbi->s_group_desc = kvmalloc(db_count *
3951 					  sizeof(struct buffer_head *),
3952 					  GFP_KERNEL);
3953 	if (sbi->s_group_desc == NULL) {
3954 		ext4_msg(sb, KERN_ERR, "not enough memory");
3955 		ret = -ENOMEM;
3956 		goto failed_mount;
3957 	}
3958 
3959 	bgl_lock_init(sbi->s_blockgroup_lock);
3960 
3961 	/* Pre-read the descriptors into the buffer cache */
3962 	for (i = 0; i < db_count; i++) {
3963 		block = descriptor_loc(sb, logical_sb_block, i);
3964 		sb_breadahead(sb, block);
3965 	}
3966 
3967 	for (i = 0; i < db_count; i++) {
3968 		block = descriptor_loc(sb, logical_sb_block, i);
3969 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3970 		if (!sbi->s_group_desc[i]) {
3971 			ext4_msg(sb, KERN_ERR,
3972 			       "can't read group descriptor %d", i);
3973 			db_count = i;
3974 			goto failed_mount2;
3975 		}
3976 	}
3977 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3978 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3979 		ret = -EFSCORRUPTED;
3980 		goto failed_mount2;
3981 	}
3982 
3983 	sbi->s_gdb_count = db_count;
3984 
3985 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
3986 
3987 	/* Register extent status tree shrinker */
3988 	if (ext4_es_register_shrinker(sbi))
3989 		goto failed_mount3;
3990 
3991 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3992 	sbi->s_extent_max_zeroout_kb = 32;
3993 
3994 	/*
3995 	 * set up enough so that it can read an inode
3996 	 */
3997 	sb->s_op = &ext4_sops;
3998 	sb->s_export_op = &ext4_export_ops;
3999 	sb->s_xattr = ext4_xattr_handlers;
4000 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4001 	sb->s_cop = &ext4_cryptops;
4002 #endif
4003 #ifdef CONFIG_QUOTA
4004 	sb->dq_op = &ext4_quota_operations;
4005 	if (ext4_has_feature_quota(sb))
4006 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4007 	else
4008 		sb->s_qcop = &ext4_qctl_operations;
4009 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4010 #endif
4011 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4012 
4013 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4014 	mutex_init(&sbi->s_orphan_lock);
4015 
4016 	sb->s_root = NULL;
4017 
4018 	needs_recovery = (es->s_last_orphan != 0 ||
4019 			  ext4_has_feature_journal_needs_recovery(sb));
4020 
4021 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4022 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4023 			goto failed_mount3a;
4024 
4025 	/*
4026 	 * The first inode we look at is the journal inode.  Don't try
4027 	 * root first: it may be modified in the journal!
4028 	 */
4029 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4030 		err = ext4_load_journal(sb, es, journal_devnum);
4031 		if (err)
4032 			goto failed_mount3a;
4033 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4034 		   ext4_has_feature_journal_needs_recovery(sb)) {
4035 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4036 		       "suppressed and not mounted read-only");
4037 		goto failed_mount_wq;
4038 	} else {
4039 		/* Nojournal mode, all journal mount options are illegal */
4040 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4041 			ext4_msg(sb, KERN_ERR, "can't mount with "
4042 				 "journal_checksum, fs mounted w/o journal");
4043 			goto failed_mount_wq;
4044 		}
4045 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4046 			ext4_msg(sb, KERN_ERR, "can't mount with "
4047 				 "journal_async_commit, fs mounted w/o journal");
4048 			goto failed_mount_wq;
4049 		}
4050 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4051 			ext4_msg(sb, KERN_ERR, "can't mount with "
4052 				 "commit=%lu, fs mounted w/o journal",
4053 				 sbi->s_commit_interval / HZ);
4054 			goto failed_mount_wq;
4055 		}
4056 		if (EXT4_MOUNT_DATA_FLAGS &
4057 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4058 			ext4_msg(sb, KERN_ERR, "can't mount with "
4059 				 "data=, fs mounted w/o journal");
4060 			goto failed_mount_wq;
4061 		}
4062 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4063 		clear_opt(sb, JOURNAL_CHECKSUM);
4064 		clear_opt(sb, DATA_FLAGS);
4065 		sbi->s_journal = NULL;
4066 		needs_recovery = 0;
4067 		goto no_journal;
4068 	}
4069 
4070 	if (ext4_has_feature_64bit(sb) &&
4071 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4072 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4073 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4074 		goto failed_mount_wq;
4075 	}
4076 
4077 	if (!set_journal_csum_feature_set(sb)) {
4078 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4079 			 "feature set");
4080 		goto failed_mount_wq;
4081 	}
4082 
4083 	/* We have now updated the journal if required, so we can
4084 	 * validate the data journaling mode. */
4085 	switch (test_opt(sb, DATA_FLAGS)) {
4086 	case 0:
4087 		/* No mode set, assume a default based on the journal
4088 		 * capabilities: ORDERED_DATA if the journal can
4089 		 * cope, else JOURNAL_DATA
4090 		 */
4091 		if (jbd2_journal_check_available_features
4092 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4093 			set_opt(sb, ORDERED_DATA);
4094 		else
4095 			set_opt(sb, JOURNAL_DATA);
4096 		break;
4097 
4098 	case EXT4_MOUNT_ORDERED_DATA:
4099 	case EXT4_MOUNT_WRITEBACK_DATA:
4100 		if (!jbd2_journal_check_available_features
4101 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4102 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4103 			       "requested data journaling mode");
4104 			goto failed_mount_wq;
4105 		}
4106 	default:
4107 		break;
4108 	}
4109 
4110 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4111 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4112 		ext4_msg(sb, KERN_ERR, "can't mount with "
4113 			"journal_async_commit in data=ordered mode");
4114 		goto failed_mount_wq;
4115 	}
4116 
4117 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4118 
4119 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4120 
4121 no_journal:
4122 	if (!test_opt(sb, NO_MBCACHE)) {
4123 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4124 		if (!sbi->s_ea_block_cache) {
4125 			ext4_msg(sb, KERN_ERR,
4126 				 "Failed to create ea_block_cache");
4127 			goto failed_mount_wq;
4128 		}
4129 
4130 		if (ext4_has_feature_ea_inode(sb)) {
4131 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4132 			if (!sbi->s_ea_inode_cache) {
4133 				ext4_msg(sb, KERN_ERR,
4134 					 "Failed to create ea_inode_cache");
4135 				goto failed_mount_wq;
4136 			}
4137 		}
4138 	}
4139 
4140 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4141 	    (blocksize != PAGE_SIZE)) {
4142 		ext4_msg(sb, KERN_ERR,
4143 			 "Unsupported blocksize for fs encryption");
4144 		goto failed_mount_wq;
4145 	}
4146 
4147 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4148 	    !ext4_has_feature_encrypt(sb)) {
4149 		ext4_set_feature_encrypt(sb);
4150 		ext4_commit_super(sb, 1);
4151 	}
4152 
4153 	/*
4154 	 * Get the # of file system overhead blocks from the
4155 	 * superblock if present.
4156 	 */
4157 	if (es->s_overhead_clusters)
4158 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4159 	else {
4160 		err = ext4_calculate_overhead(sb);
4161 		if (err)
4162 			goto failed_mount_wq;
4163 	}
4164 
4165 	/*
4166 	 * The maximum number of concurrent works can be high and
4167 	 * concurrency isn't really necessary.  Limit it to 1.
4168 	 */
4169 	EXT4_SB(sb)->rsv_conversion_wq =
4170 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4171 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4172 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4173 		ret = -ENOMEM;
4174 		goto failed_mount4;
4175 	}
4176 
4177 	/*
4178 	 * The jbd2_journal_load will have done any necessary log recovery,
4179 	 * so we can safely mount the rest of the filesystem now.
4180 	 */
4181 
4182 	root = ext4_iget(sb, EXT4_ROOT_INO);
4183 	if (IS_ERR(root)) {
4184 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4185 		ret = PTR_ERR(root);
4186 		root = NULL;
4187 		goto failed_mount4;
4188 	}
4189 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4190 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4191 		iput(root);
4192 		goto failed_mount4;
4193 	}
4194 	sb->s_root = d_make_root(root);
4195 	if (!sb->s_root) {
4196 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4197 		ret = -ENOMEM;
4198 		goto failed_mount4;
4199 	}
4200 
4201 	if (ext4_setup_super(sb, es, sb_rdonly(sb)))
4202 		sb->s_flags |= SB_RDONLY;
4203 
4204 	/* determine the minimum size of new large inodes, if present */
4205 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4206 	    sbi->s_want_extra_isize == 0) {
4207 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4208 						     EXT4_GOOD_OLD_INODE_SIZE;
4209 		if (ext4_has_feature_extra_isize(sb)) {
4210 			if (sbi->s_want_extra_isize <
4211 			    le16_to_cpu(es->s_want_extra_isize))
4212 				sbi->s_want_extra_isize =
4213 					le16_to_cpu(es->s_want_extra_isize);
4214 			if (sbi->s_want_extra_isize <
4215 			    le16_to_cpu(es->s_min_extra_isize))
4216 				sbi->s_want_extra_isize =
4217 					le16_to_cpu(es->s_min_extra_isize);
4218 		}
4219 	}
4220 	/* Check if enough inode space is available */
4221 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4222 							sbi->s_inode_size) {
4223 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4224 						       EXT4_GOOD_OLD_INODE_SIZE;
4225 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4226 			 "available");
4227 	}
4228 
4229 	ext4_set_resv_clusters(sb);
4230 
4231 	err = ext4_setup_system_zone(sb);
4232 	if (err) {
4233 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4234 			 "zone (%d)", err);
4235 		goto failed_mount4a;
4236 	}
4237 
4238 	ext4_ext_init(sb);
4239 	err = ext4_mb_init(sb);
4240 	if (err) {
4241 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4242 			 err);
4243 		goto failed_mount5;
4244 	}
4245 
4246 	block = ext4_count_free_clusters(sb);
4247 	ext4_free_blocks_count_set(sbi->s_es,
4248 				   EXT4_C2B(sbi, block));
4249 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4250 				  GFP_KERNEL);
4251 	if (!err) {
4252 		unsigned long freei = ext4_count_free_inodes(sb);
4253 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4254 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4255 					  GFP_KERNEL);
4256 	}
4257 	if (!err)
4258 		err = percpu_counter_init(&sbi->s_dirs_counter,
4259 					  ext4_count_dirs(sb), GFP_KERNEL);
4260 	if (!err)
4261 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4262 					  GFP_KERNEL);
4263 	if (!err)
4264 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4265 
4266 	if (err) {
4267 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4268 		goto failed_mount6;
4269 	}
4270 
4271 	if (ext4_has_feature_flex_bg(sb))
4272 		if (!ext4_fill_flex_info(sb)) {
4273 			ext4_msg(sb, KERN_ERR,
4274 			       "unable to initialize "
4275 			       "flex_bg meta info!");
4276 			goto failed_mount6;
4277 		}
4278 
4279 	err = ext4_register_li_request(sb, first_not_zeroed);
4280 	if (err)
4281 		goto failed_mount6;
4282 
4283 	err = ext4_register_sysfs(sb);
4284 	if (err)
4285 		goto failed_mount7;
4286 
4287 #ifdef CONFIG_QUOTA
4288 	/* Enable quota usage during mount. */
4289 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4290 		err = ext4_enable_quotas(sb);
4291 		if (err)
4292 			goto failed_mount8;
4293 	}
4294 #endif  /* CONFIG_QUOTA */
4295 
4296 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4297 	ext4_orphan_cleanup(sb, es);
4298 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4299 	if (needs_recovery) {
4300 		ext4_msg(sb, KERN_INFO, "recovery complete");
4301 		ext4_mark_recovery_complete(sb, es);
4302 	}
4303 	if (EXT4_SB(sb)->s_journal) {
4304 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4305 			descr = " journalled data mode";
4306 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4307 			descr = " ordered data mode";
4308 		else
4309 			descr = " writeback data mode";
4310 	} else
4311 		descr = "out journal";
4312 
4313 	if (test_opt(sb, DISCARD)) {
4314 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4315 		if (!blk_queue_discard(q))
4316 			ext4_msg(sb, KERN_WARNING,
4317 				 "mounting with \"discard\" option, but "
4318 				 "the device does not support discard");
4319 	}
4320 
4321 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4322 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4323 			 "Opts: %.*s%s%s", descr,
4324 			 (int) sizeof(sbi->s_es->s_mount_opts),
4325 			 sbi->s_es->s_mount_opts,
4326 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4327 
4328 	if (es->s_error_count)
4329 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4330 
4331 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4332 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4333 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4334 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4335 
4336 	kfree(orig_data);
4337 	return 0;
4338 
4339 cantfind_ext4:
4340 	if (!silent)
4341 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4342 	goto failed_mount;
4343 
4344 #ifdef CONFIG_QUOTA
4345 failed_mount8:
4346 	ext4_unregister_sysfs(sb);
4347 #endif
4348 failed_mount7:
4349 	ext4_unregister_li_request(sb);
4350 failed_mount6:
4351 	ext4_mb_release(sb);
4352 	if (sbi->s_flex_groups)
4353 		kvfree(sbi->s_flex_groups);
4354 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4355 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4356 	percpu_counter_destroy(&sbi->s_dirs_counter);
4357 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4358 failed_mount5:
4359 	ext4_ext_release(sb);
4360 	ext4_release_system_zone(sb);
4361 failed_mount4a:
4362 	dput(sb->s_root);
4363 	sb->s_root = NULL;
4364 failed_mount4:
4365 	ext4_msg(sb, KERN_ERR, "mount failed");
4366 	if (EXT4_SB(sb)->rsv_conversion_wq)
4367 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4368 failed_mount_wq:
4369 	if (sbi->s_ea_inode_cache) {
4370 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4371 		sbi->s_ea_inode_cache = NULL;
4372 	}
4373 	if (sbi->s_ea_block_cache) {
4374 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4375 		sbi->s_ea_block_cache = NULL;
4376 	}
4377 	if (sbi->s_journal) {
4378 		jbd2_journal_destroy(sbi->s_journal);
4379 		sbi->s_journal = NULL;
4380 	}
4381 failed_mount3a:
4382 	ext4_es_unregister_shrinker(sbi);
4383 failed_mount3:
4384 	del_timer_sync(&sbi->s_err_report);
4385 	if (sbi->s_mmp_tsk)
4386 		kthread_stop(sbi->s_mmp_tsk);
4387 failed_mount2:
4388 	for (i = 0; i < db_count; i++)
4389 		brelse(sbi->s_group_desc[i]);
4390 	kvfree(sbi->s_group_desc);
4391 failed_mount:
4392 	if (sbi->s_chksum_driver)
4393 		crypto_free_shash(sbi->s_chksum_driver);
4394 #ifdef CONFIG_QUOTA
4395 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4396 		kfree(sbi->s_qf_names[i]);
4397 #endif
4398 	ext4_blkdev_remove(sbi);
4399 	brelse(bh);
4400 out_fail:
4401 	sb->s_fs_info = NULL;
4402 	kfree(sbi->s_blockgroup_lock);
4403 out_free_base:
4404 	kfree(sbi);
4405 	kfree(orig_data);
4406 	fs_put_dax(dax_dev);
4407 	return err ? err : ret;
4408 }
4409 
4410 /*
4411  * Setup any per-fs journal parameters now.  We'll do this both on
4412  * initial mount, once the journal has been initialised but before we've
4413  * done any recovery; and again on any subsequent remount.
4414  */
4415 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4416 {
4417 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4418 
4419 	journal->j_commit_interval = sbi->s_commit_interval;
4420 	journal->j_min_batch_time = sbi->s_min_batch_time;
4421 	journal->j_max_batch_time = sbi->s_max_batch_time;
4422 
4423 	write_lock(&journal->j_state_lock);
4424 	if (test_opt(sb, BARRIER))
4425 		journal->j_flags |= JBD2_BARRIER;
4426 	else
4427 		journal->j_flags &= ~JBD2_BARRIER;
4428 	if (test_opt(sb, DATA_ERR_ABORT))
4429 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4430 	else
4431 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4432 	write_unlock(&journal->j_state_lock);
4433 }
4434 
4435 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4436 					     unsigned int journal_inum)
4437 {
4438 	struct inode *journal_inode;
4439 
4440 	/*
4441 	 * Test for the existence of a valid inode on disk.  Bad things
4442 	 * happen if we iget() an unused inode, as the subsequent iput()
4443 	 * will try to delete it.
4444 	 */
4445 	journal_inode = ext4_iget(sb, journal_inum);
4446 	if (IS_ERR(journal_inode)) {
4447 		ext4_msg(sb, KERN_ERR, "no journal found");
4448 		return NULL;
4449 	}
4450 	if (!journal_inode->i_nlink) {
4451 		make_bad_inode(journal_inode);
4452 		iput(journal_inode);
4453 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4454 		return NULL;
4455 	}
4456 
4457 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4458 		  journal_inode, journal_inode->i_size);
4459 	if (!S_ISREG(journal_inode->i_mode)) {
4460 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4461 		iput(journal_inode);
4462 		return NULL;
4463 	}
4464 	return journal_inode;
4465 }
4466 
4467 static journal_t *ext4_get_journal(struct super_block *sb,
4468 				   unsigned int journal_inum)
4469 {
4470 	struct inode *journal_inode;
4471 	journal_t *journal;
4472 
4473 	BUG_ON(!ext4_has_feature_journal(sb));
4474 
4475 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4476 	if (!journal_inode)
4477 		return NULL;
4478 
4479 	journal = jbd2_journal_init_inode(journal_inode);
4480 	if (!journal) {
4481 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4482 		iput(journal_inode);
4483 		return NULL;
4484 	}
4485 	journal->j_private = sb;
4486 	ext4_init_journal_params(sb, journal);
4487 	return journal;
4488 }
4489 
4490 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4491 				       dev_t j_dev)
4492 {
4493 	struct buffer_head *bh;
4494 	journal_t *journal;
4495 	ext4_fsblk_t start;
4496 	ext4_fsblk_t len;
4497 	int hblock, blocksize;
4498 	ext4_fsblk_t sb_block;
4499 	unsigned long offset;
4500 	struct ext4_super_block *es;
4501 	struct block_device *bdev;
4502 
4503 	BUG_ON(!ext4_has_feature_journal(sb));
4504 
4505 	bdev = ext4_blkdev_get(j_dev, sb);
4506 	if (bdev == NULL)
4507 		return NULL;
4508 
4509 	blocksize = sb->s_blocksize;
4510 	hblock = bdev_logical_block_size(bdev);
4511 	if (blocksize < hblock) {
4512 		ext4_msg(sb, KERN_ERR,
4513 			"blocksize too small for journal device");
4514 		goto out_bdev;
4515 	}
4516 
4517 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4518 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4519 	set_blocksize(bdev, blocksize);
4520 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4521 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4522 		       "external journal");
4523 		goto out_bdev;
4524 	}
4525 
4526 	es = (struct ext4_super_block *) (bh->b_data + offset);
4527 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4528 	    !(le32_to_cpu(es->s_feature_incompat) &
4529 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4530 		ext4_msg(sb, KERN_ERR, "external journal has "
4531 					"bad superblock");
4532 		brelse(bh);
4533 		goto out_bdev;
4534 	}
4535 
4536 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4537 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4538 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4539 		ext4_msg(sb, KERN_ERR, "external journal has "
4540 				       "corrupt superblock");
4541 		brelse(bh);
4542 		goto out_bdev;
4543 	}
4544 
4545 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4546 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4547 		brelse(bh);
4548 		goto out_bdev;
4549 	}
4550 
4551 	len = ext4_blocks_count(es);
4552 	start = sb_block + 1;
4553 	brelse(bh);	/* we're done with the superblock */
4554 
4555 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4556 					start, len, blocksize);
4557 	if (!journal) {
4558 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4559 		goto out_bdev;
4560 	}
4561 	journal->j_private = sb;
4562 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4563 	wait_on_buffer(journal->j_sb_buffer);
4564 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4565 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4566 		goto out_journal;
4567 	}
4568 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4569 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4570 					"user (unsupported) - %d",
4571 			be32_to_cpu(journal->j_superblock->s_nr_users));
4572 		goto out_journal;
4573 	}
4574 	EXT4_SB(sb)->journal_bdev = bdev;
4575 	ext4_init_journal_params(sb, journal);
4576 	return journal;
4577 
4578 out_journal:
4579 	jbd2_journal_destroy(journal);
4580 out_bdev:
4581 	ext4_blkdev_put(bdev);
4582 	return NULL;
4583 }
4584 
4585 static int ext4_load_journal(struct super_block *sb,
4586 			     struct ext4_super_block *es,
4587 			     unsigned long journal_devnum)
4588 {
4589 	journal_t *journal;
4590 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4591 	dev_t journal_dev;
4592 	int err = 0;
4593 	int really_read_only;
4594 
4595 	BUG_ON(!ext4_has_feature_journal(sb));
4596 
4597 	if (journal_devnum &&
4598 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4599 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4600 			"numbers have changed");
4601 		journal_dev = new_decode_dev(journal_devnum);
4602 	} else
4603 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4604 
4605 	really_read_only = bdev_read_only(sb->s_bdev);
4606 
4607 	/*
4608 	 * Are we loading a blank journal or performing recovery after a
4609 	 * crash?  For recovery, we need to check in advance whether we
4610 	 * can get read-write access to the device.
4611 	 */
4612 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4613 		if (sb_rdonly(sb)) {
4614 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4615 					"required on readonly filesystem");
4616 			if (really_read_only) {
4617 				ext4_msg(sb, KERN_ERR, "write access "
4618 					"unavailable, cannot proceed "
4619 					"(try mounting with noload)");
4620 				return -EROFS;
4621 			}
4622 			ext4_msg(sb, KERN_INFO, "write access will "
4623 			       "be enabled during recovery");
4624 		}
4625 	}
4626 
4627 	if (journal_inum && journal_dev) {
4628 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4629 		       "and inode journals!");
4630 		return -EINVAL;
4631 	}
4632 
4633 	if (journal_inum) {
4634 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4635 			return -EINVAL;
4636 	} else {
4637 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4638 			return -EINVAL;
4639 	}
4640 
4641 	if (!(journal->j_flags & JBD2_BARRIER))
4642 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4643 
4644 	if (!ext4_has_feature_journal_needs_recovery(sb))
4645 		err = jbd2_journal_wipe(journal, !really_read_only);
4646 	if (!err) {
4647 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4648 		if (save)
4649 			memcpy(save, ((char *) es) +
4650 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4651 		err = jbd2_journal_load(journal);
4652 		if (save)
4653 			memcpy(((char *) es) + EXT4_S_ERR_START,
4654 			       save, EXT4_S_ERR_LEN);
4655 		kfree(save);
4656 	}
4657 
4658 	if (err) {
4659 		ext4_msg(sb, KERN_ERR, "error loading journal");
4660 		jbd2_journal_destroy(journal);
4661 		return err;
4662 	}
4663 
4664 	EXT4_SB(sb)->s_journal = journal;
4665 	ext4_clear_journal_err(sb, es);
4666 
4667 	if (!really_read_only && journal_devnum &&
4668 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4669 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4670 
4671 		/* Make sure we flush the recovery flag to disk. */
4672 		ext4_commit_super(sb, 1);
4673 	}
4674 
4675 	return 0;
4676 }
4677 
4678 static int ext4_commit_super(struct super_block *sb, int sync)
4679 {
4680 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4681 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4682 	int error = 0;
4683 
4684 	if (!sbh || block_device_ejected(sb))
4685 		return error;
4686 	/*
4687 	 * If the file system is mounted read-only, don't update the
4688 	 * superblock write time.  This avoids updating the superblock
4689 	 * write time when we are mounting the root file system
4690 	 * read/only but we need to replay the journal; at that point,
4691 	 * for people who are east of GMT and who make their clock
4692 	 * tick in localtime for Windows bug-for-bug compatibility,
4693 	 * the clock is set in the future, and this will cause e2fsck
4694 	 * to complain and force a full file system check.
4695 	 */
4696 	if (!(sb->s_flags & SB_RDONLY))
4697 		es->s_wtime = cpu_to_le32(get_seconds());
4698 	if (sb->s_bdev->bd_part)
4699 		es->s_kbytes_written =
4700 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4701 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4702 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4703 	else
4704 		es->s_kbytes_written =
4705 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4706 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4707 		ext4_free_blocks_count_set(es,
4708 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4709 				&EXT4_SB(sb)->s_freeclusters_counter)));
4710 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4711 		es->s_free_inodes_count =
4712 			cpu_to_le32(percpu_counter_sum_positive(
4713 				&EXT4_SB(sb)->s_freeinodes_counter));
4714 	BUFFER_TRACE(sbh, "marking dirty");
4715 	ext4_superblock_csum_set(sb);
4716 	if (sync)
4717 		lock_buffer(sbh);
4718 	if (buffer_write_io_error(sbh)) {
4719 		/*
4720 		 * Oh, dear.  A previous attempt to write the
4721 		 * superblock failed.  This could happen because the
4722 		 * USB device was yanked out.  Or it could happen to
4723 		 * be a transient write error and maybe the block will
4724 		 * be remapped.  Nothing we can do but to retry the
4725 		 * write and hope for the best.
4726 		 */
4727 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4728 		       "superblock detected");
4729 		clear_buffer_write_io_error(sbh);
4730 		set_buffer_uptodate(sbh);
4731 	}
4732 	mark_buffer_dirty(sbh);
4733 	if (sync) {
4734 		unlock_buffer(sbh);
4735 		error = __sync_dirty_buffer(sbh,
4736 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4737 		if (error)
4738 			return error;
4739 
4740 		error = buffer_write_io_error(sbh);
4741 		if (error) {
4742 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4743 			       "superblock");
4744 			clear_buffer_write_io_error(sbh);
4745 			set_buffer_uptodate(sbh);
4746 		}
4747 	}
4748 	return error;
4749 }
4750 
4751 /*
4752  * Have we just finished recovery?  If so, and if we are mounting (or
4753  * remounting) the filesystem readonly, then we will end up with a
4754  * consistent fs on disk.  Record that fact.
4755  */
4756 static void ext4_mark_recovery_complete(struct super_block *sb,
4757 					struct ext4_super_block *es)
4758 {
4759 	journal_t *journal = EXT4_SB(sb)->s_journal;
4760 
4761 	if (!ext4_has_feature_journal(sb)) {
4762 		BUG_ON(journal != NULL);
4763 		return;
4764 	}
4765 	jbd2_journal_lock_updates(journal);
4766 	if (jbd2_journal_flush(journal) < 0)
4767 		goto out;
4768 
4769 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
4770 		ext4_clear_feature_journal_needs_recovery(sb);
4771 		ext4_commit_super(sb, 1);
4772 	}
4773 
4774 out:
4775 	jbd2_journal_unlock_updates(journal);
4776 }
4777 
4778 /*
4779  * If we are mounting (or read-write remounting) a filesystem whose journal
4780  * has recorded an error from a previous lifetime, move that error to the
4781  * main filesystem now.
4782  */
4783 static void ext4_clear_journal_err(struct super_block *sb,
4784 				   struct ext4_super_block *es)
4785 {
4786 	journal_t *journal;
4787 	int j_errno;
4788 	const char *errstr;
4789 
4790 	BUG_ON(!ext4_has_feature_journal(sb));
4791 
4792 	journal = EXT4_SB(sb)->s_journal;
4793 
4794 	/*
4795 	 * Now check for any error status which may have been recorded in the
4796 	 * journal by a prior ext4_error() or ext4_abort()
4797 	 */
4798 
4799 	j_errno = jbd2_journal_errno(journal);
4800 	if (j_errno) {
4801 		char nbuf[16];
4802 
4803 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4804 		ext4_warning(sb, "Filesystem error recorded "
4805 			     "from previous mount: %s", errstr);
4806 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4807 
4808 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4809 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4810 		ext4_commit_super(sb, 1);
4811 
4812 		jbd2_journal_clear_err(journal);
4813 		jbd2_journal_update_sb_errno(journal);
4814 	}
4815 }
4816 
4817 /*
4818  * Force the running and committing transactions to commit,
4819  * and wait on the commit.
4820  */
4821 int ext4_force_commit(struct super_block *sb)
4822 {
4823 	journal_t *journal;
4824 
4825 	if (sb_rdonly(sb))
4826 		return 0;
4827 
4828 	journal = EXT4_SB(sb)->s_journal;
4829 	return ext4_journal_force_commit(journal);
4830 }
4831 
4832 static int ext4_sync_fs(struct super_block *sb, int wait)
4833 {
4834 	int ret = 0;
4835 	tid_t target;
4836 	bool needs_barrier = false;
4837 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4838 
4839 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
4840 		return 0;
4841 
4842 	trace_ext4_sync_fs(sb, wait);
4843 	flush_workqueue(sbi->rsv_conversion_wq);
4844 	/*
4845 	 * Writeback quota in non-journalled quota case - journalled quota has
4846 	 * no dirty dquots
4847 	 */
4848 	dquot_writeback_dquots(sb, -1);
4849 	/*
4850 	 * Data writeback is possible w/o journal transaction, so barrier must
4851 	 * being sent at the end of the function. But we can skip it if
4852 	 * transaction_commit will do it for us.
4853 	 */
4854 	if (sbi->s_journal) {
4855 		target = jbd2_get_latest_transaction(sbi->s_journal);
4856 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4857 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4858 			needs_barrier = true;
4859 
4860 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4861 			if (wait)
4862 				ret = jbd2_log_wait_commit(sbi->s_journal,
4863 							   target);
4864 		}
4865 	} else if (wait && test_opt(sb, BARRIER))
4866 		needs_barrier = true;
4867 	if (needs_barrier) {
4868 		int err;
4869 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4870 		if (!ret)
4871 			ret = err;
4872 	}
4873 
4874 	return ret;
4875 }
4876 
4877 /*
4878  * LVM calls this function before a (read-only) snapshot is created.  This
4879  * gives us a chance to flush the journal completely and mark the fs clean.
4880  *
4881  * Note that only this function cannot bring a filesystem to be in a clean
4882  * state independently. It relies on upper layer to stop all data & metadata
4883  * modifications.
4884  */
4885 static int ext4_freeze(struct super_block *sb)
4886 {
4887 	int error = 0;
4888 	journal_t *journal;
4889 
4890 	if (sb_rdonly(sb))
4891 		return 0;
4892 
4893 	journal = EXT4_SB(sb)->s_journal;
4894 
4895 	if (journal) {
4896 		/* Now we set up the journal barrier. */
4897 		jbd2_journal_lock_updates(journal);
4898 
4899 		/*
4900 		 * Don't clear the needs_recovery flag if we failed to
4901 		 * flush the journal.
4902 		 */
4903 		error = jbd2_journal_flush(journal);
4904 		if (error < 0)
4905 			goto out;
4906 
4907 		/* Journal blocked and flushed, clear needs_recovery flag. */
4908 		ext4_clear_feature_journal_needs_recovery(sb);
4909 	}
4910 
4911 	error = ext4_commit_super(sb, 1);
4912 out:
4913 	if (journal)
4914 		/* we rely on upper layer to stop further updates */
4915 		jbd2_journal_unlock_updates(journal);
4916 	return error;
4917 }
4918 
4919 /*
4920  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4921  * flag here, even though the filesystem is not technically dirty yet.
4922  */
4923 static int ext4_unfreeze(struct super_block *sb)
4924 {
4925 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
4926 		return 0;
4927 
4928 	if (EXT4_SB(sb)->s_journal) {
4929 		/* Reset the needs_recovery flag before the fs is unlocked. */
4930 		ext4_set_feature_journal_needs_recovery(sb);
4931 	}
4932 
4933 	ext4_commit_super(sb, 1);
4934 	return 0;
4935 }
4936 
4937 /*
4938  * Structure to save mount options for ext4_remount's benefit
4939  */
4940 struct ext4_mount_options {
4941 	unsigned long s_mount_opt;
4942 	unsigned long s_mount_opt2;
4943 	kuid_t s_resuid;
4944 	kgid_t s_resgid;
4945 	unsigned long s_commit_interval;
4946 	u32 s_min_batch_time, s_max_batch_time;
4947 #ifdef CONFIG_QUOTA
4948 	int s_jquota_fmt;
4949 	char *s_qf_names[EXT4_MAXQUOTAS];
4950 #endif
4951 };
4952 
4953 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4954 {
4955 	struct ext4_super_block *es;
4956 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4957 	unsigned long old_sb_flags;
4958 	struct ext4_mount_options old_opts;
4959 	int enable_quota = 0;
4960 	ext4_group_t g;
4961 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4962 	int err = 0;
4963 #ifdef CONFIG_QUOTA
4964 	int i, j;
4965 #endif
4966 	char *orig_data = kstrdup(data, GFP_KERNEL);
4967 
4968 	/* Store the original options */
4969 	old_sb_flags = sb->s_flags;
4970 	old_opts.s_mount_opt = sbi->s_mount_opt;
4971 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4972 	old_opts.s_resuid = sbi->s_resuid;
4973 	old_opts.s_resgid = sbi->s_resgid;
4974 	old_opts.s_commit_interval = sbi->s_commit_interval;
4975 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4976 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4977 #ifdef CONFIG_QUOTA
4978 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4979 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4980 		if (sbi->s_qf_names[i]) {
4981 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4982 							 GFP_KERNEL);
4983 			if (!old_opts.s_qf_names[i]) {
4984 				for (j = 0; j < i; j++)
4985 					kfree(old_opts.s_qf_names[j]);
4986 				kfree(orig_data);
4987 				return -ENOMEM;
4988 			}
4989 		} else
4990 			old_opts.s_qf_names[i] = NULL;
4991 #endif
4992 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4993 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4994 
4995 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4996 		err = -EINVAL;
4997 		goto restore_opts;
4998 	}
4999 
5000 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5001 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5002 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5003 			 "during remount not supported; ignoring");
5004 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5005 	}
5006 
5007 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5008 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5009 			ext4_msg(sb, KERN_ERR, "can't mount with "
5010 				 "both data=journal and delalloc");
5011 			err = -EINVAL;
5012 			goto restore_opts;
5013 		}
5014 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5015 			ext4_msg(sb, KERN_ERR, "can't mount with "
5016 				 "both data=journal and dioread_nolock");
5017 			err = -EINVAL;
5018 			goto restore_opts;
5019 		}
5020 		if (test_opt(sb, DAX)) {
5021 			ext4_msg(sb, KERN_ERR, "can't mount with "
5022 				 "both data=journal and dax");
5023 			err = -EINVAL;
5024 			goto restore_opts;
5025 		}
5026 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5027 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5028 			ext4_msg(sb, KERN_ERR, "can't mount with "
5029 				"journal_async_commit in data=ordered mode");
5030 			err = -EINVAL;
5031 			goto restore_opts;
5032 		}
5033 	}
5034 
5035 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5036 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5037 		err = -EINVAL;
5038 		goto restore_opts;
5039 	}
5040 
5041 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5042 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5043 			"dax flag with busy inodes while remounting");
5044 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5045 	}
5046 
5047 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5048 		ext4_abort(sb, "Abort forced by user");
5049 
5050 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5051 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5052 
5053 	es = sbi->s_es;
5054 
5055 	if (sbi->s_journal) {
5056 		ext4_init_journal_params(sb, sbi->s_journal);
5057 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5058 	}
5059 
5060 	if (*flags & SB_LAZYTIME)
5061 		sb->s_flags |= SB_LAZYTIME;
5062 
5063 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5064 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5065 			err = -EROFS;
5066 			goto restore_opts;
5067 		}
5068 
5069 		if (*flags & SB_RDONLY) {
5070 			err = sync_filesystem(sb);
5071 			if (err < 0)
5072 				goto restore_opts;
5073 			err = dquot_suspend(sb, -1);
5074 			if (err < 0)
5075 				goto restore_opts;
5076 
5077 			/*
5078 			 * First of all, the unconditional stuff we have to do
5079 			 * to disable replay of the journal when we next remount
5080 			 */
5081 			sb->s_flags |= SB_RDONLY;
5082 
5083 			/*
5084 			 * OK, test if we are remounting a valid rw partition
5085 			 * readonly, and if so set the rdonly flag and then
5086 			 * mark the partition as valid again.
5087 			 */
5088 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5089 			    (sbi->s_mount_state & EXT4_VALID_FS))
5090 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5091 
5092 			if (sbi->s_journal)
5093 				ext4_mark_recovery_complete(sb, es);
5094 		} else {
5095 			/* Make sure we can mount this feature set readwrite */
5096 			if (ext4_has_feature_readonly(sb) ||
5097 			    !ext4_feature_set_ok(sb, 0)) {
5098 				err = -EROFS;
5099 				goto restore_opts;
5100 			}
5101 			/*
5102 			 * Make sure the group descriptor checksums
5103 			 * are sane.  If they aren't, refuse to remount r/w.
5104 			 */
5105 			for (g = 0; g < sbi->s_groups_count; g++) {
5106 				struct ext4_group_desc *gdp =
5107 					ext4_get_group_desc(sb, g, NULL);
5108 
5109 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5110 					ext4_msg(sb, KERN_ERR,
5111 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5112 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5113 					       le16_to_cpu(gdp->bg_checksum));
5114 					err = -EFSBADCRC;
5115 					goto restore_opts;
5116 				}
5117 			}
5118 
5119 			/*
5120 			 * If we have an unprocessed orphan list hanging
5121 			 * around from a previously readonly bdev mount,
5122 			 * require a full umount/remount for now.
5123 			 */
5124 			if (es->s_last_orphan) {
5125 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5126 				       "remount RDWR because of unprocessed "
5127 				       "orphan inode list.  Please "
5128 				       "umount/remount instead");
5129 				err = -EINVAL;
5130 				goto restore_opts;
5131 			}
5132 
5133 			/*
5134 			 * Mounting a RDONLY partition read-write, so reread
5135 			 * and store the current valid flag.  (It may have
5136 			 * been changed by e2fsck since we originally mounted
5137 			 * the partition.)
5138 			 */
5139 			if (sbi->s_journal)
5140 				ext4_clear_journal_err(sb, es);
5141 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5142 			if (!ext4_setup_super(sb, es, 0))
5143 				sb->s_flags &= ~SB_RDONLY;
5144 			if (ext4_has_feature_mmp(sb))
5145 				if (ext4_multi_mount_protect(sb,
5146 						le64_to_cpu(es->s_mmp_block))) {
5147 					err = -EROFS;
5148 					goto restore_opts;
5149 				}
5150 			enable_quota = 1;
5151 		}
5152 	}
5153 
5154 	/*
5155 	 * Reinitialize lazy itable initialization thread based on
5156 	 * current settings
5157 	 */
5158 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5159 		ext4_unregister_li_request(sb);
5160 	else {
5161 		ext4_group_t first_not_zeroed;
5162 		first_not_zeroed = ext4_has_uninit_itable(sb);
5163 		ext4_register_li_request(sb, first_not_zeroed);
5164 	}
5165 
5166 	ext4_setup_system_zone(sb);
5167 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY))
5168 		ext4_commit_super(sb, 1);
5169 
5170 #ifdef CONFIG_QUOTA
5171 	/* Release old quota file names */
5172 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5173 		kfree(old_opts.s_qf_names[i]);
5174 	if (enable_quota) {
5175 		if (sb_any_quota_suspended(sb))
5176 			dquot_resume(sb, -1);
5177 		else if (ext4_has_feature_quota(sb)) {
5178 			err = ext4_enable_quotas(sb);
5179 			if (err)
5180 				goto restore_opts;
5181 		}
5182 	}
5183 #endif
5184 
5185 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5186 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5187 	kfree(orig_data);
5188 	return 0;
5189 
5190 restore_opts:
5191 	sb->s_flags = old_sb_flags;
5192 	sbi->s_mount_opt = old_opts.s_mount_opt;
5193 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5194 	sbi->s_resuid = old_opts.s_resuid;
5195 	sbi->s_resgid = old_opts.s_resgid;
5196 	sbi->s_commit_interval = old_opts.s_commit_interval;
5197 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5198 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5199 #ifdef CONFIG_QUOTA
5200 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5201 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5202 		kfree(sbi->s_qf_names[i]);
5203 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5204 	}
5205 #endif
5206 	kfree(orig_data);
5207 	return err;
5208 }
5209 
5210 #ifdef CONFIG_QUOTA
5211 static int ext4_statfs_project(struct super_block *sb,
5212 			       kprojid_t projid, struct kstatfs *buf)
5213 {
5214 	struct kqid qid;
5215 	struct dquot *dquot;
5216 	u64 limit;
5217 	u64 curblock;
5218 
5219 	qid = make_kqid_projid(projid);
5220 	dquot = dqget(sb, qid);
5221 	if (IS_ERR(dquot))
5222 		return PTR_ERR(dquot);
5223 	spin_lock(&dquot->dq_dqb_lock);
5224 
5225 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5226 		 dquot->dq_dqb.dqb_bsoftlimit :
5227 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5228 	if (limit && buf->f_blocks > limit) {
5229 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5230 		buf->f_blocks = limit;
5231 		buf->f_bfree = buf->f_bavail =
5232 			(buf->f_blocks > curblock) ?
5233 			 (buf->f_blocks - curblock) : 0;
5234 	}
5235 
5236 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5237 		dquot->dq_dqb.dqb_isoftlimit :
5238 		dquot->dq_dqb.dqb_ihardlimit;
5239 	if (limit && buf->f_files > limit) {
5240 		buf->f_files = limit;
5241 		buf->f_ffree =
5242 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5243 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5244 	}
5245 
5246 	spin_unlock(&dquot->dq_dqb_lock);
5247 	dqput(dquot);
5248 	return 0;
5249 }
5250 #endif
5251 
5252 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5253 {
5254 	struct super_block *sb = dentry->d_sb;
5255 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5256 	struct ext4_super_block *es = sbi->s_es;
5257 	ext4_fsblk_t overhead = 0, resv_blocks;
5258 	u64 fsid;
5259 	s64 bfree;
5260 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5261 
5262 	if (!test_opt(sb, MINIX_DF))
5263 		overhead = sbi->s_overhead;
5264 
5265 	buf->f_type = EXT4_SUPER_MAGIC;
5266 	buf->f_bsize = sb->s_blocksize;
5267 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5268 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5269 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5270 	/* prevent underflow in case that few free space is available */
5271 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5272 	buf->f_bavail = buf->f_bfree -
5273 			(ext4_r_blocks_count(es) + resv_blocks);
5274 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5275 		buf->f_bavail = 0;
5276 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5277 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5278 	buf->f_namelen = EXT4_NAME_LEN;
5279 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5280 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5281 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5282 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5283 
5284 #ifdef CONFIG_QUOTA
5285 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5286 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5287 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5288 #endif
5289 	return 0;
5290 }
5291 
5292 
5293 #ifdef CONFIG_QUOTA
5294 
5295 /*
5296  * Helper functions so that transaction is started before we acquire dqio_sem
5297  * to keep correct lock ordering of transaction > dqio_sem
5298  */
5299 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5300 {
5301 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5302 }
5303 
5304 static int ext4_write_dquot(struct dquot *dquot)
5305 {
5306 	int ret, err;
5307 	handle_t *handle;
5308 	struct inode *inode;
5309 
5310 	inode = dquot_to_inode(dquot);
5311 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5312 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5313 	if (IS_ERR(handle))
5314 		return PTR_ERR(handle);
5315 	ret = dquot_commit(dquot);
5316 	err = ext4_journal_stop(handle);
5317 	if (!ret)
5318 		ret = err;
5319 	return ret;
5320 }
5321 
5322 static int ext4_acquire_dquot(struct dquot *dquot)
5323 {
5324 	int ret, err;
5325 	handle_t *handle;
5326 
5327 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5328 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5329 	if (IS_ERR(handle))
5330 		return PTR_ERR(handle);
5331 	ret = dquot_acquire(dquot);
5332 	err = ext4_journal_stop(handle);
5333 	if (!ret)
5334 		ret = err;
5335 	return ret;
5336 }
5337 
5338 static int ext4_release_dquot(struct dquot *dquot)
5339 {
5340 	int ret, err;
5341 	handle_t *handle;
5342 
5343 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5344 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5345 	if (IS_ERR(handle)) {
5346 		/* Release dquot anyway to avoid endless cycle in dqput() */
5347 		dquot_release(dquot);
5348 		return PTR_ERR(handle);
5349 	}
5350 	ret = dquot_release(dquot);
5351 	err = ext4_journal_stop(handle);
5352 	if (!ret)
5353 		ret = err;
5354 	return ret;
5355 }
5356 
5357 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5358 {
5359 	struct super_block *sb = dquot->dq_sb;
5360 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5361 
5362 	/* Are we journaling quotas? */
5363 	if (ext4_has_feature_quota(sb) ||
5364 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5365 		dquot_mark_dquot_dirty(dquot);
5366 		return ext4_write_dquot(dquot);
5367 	} else {
5368 		return dquot_mark_dquot_dirty(dquot);
5369 	}
5370 }
5371 
5372 static int ext4_write_info(struct super_block *sb, int type)
5373 {
5374 	int ret, err;
5375 	handle_t *handle;
5376 
5377 	/* Data block + inode block */
5378 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5379 	if (IS_ERR(handle))
5380 		return PTR_ERR(handle);
5381 	ret = dquot_commit_info(sb, type);
5382 	err = ext4_journal_stop(handle);
5383 	if (!ret)
5384 		ret = err;
5385 	return ret;
5386 }
5387 
5388 /*
5389  * Turn on quotas during mount time - we need to find
5390  * the quota file and such...
5391  */
5392 static int ext4_quota_on_mount(struct super_block *sb, int type)
5393 {
5394 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5395 					EXT4_SB(sb)->s_jquota_fmt, type);
5396 }
5397 
5398 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5399 {
5400 	struct ext4_inode_info *ei = EXT4_I(inode);
5401 
5402 	/* The first argument of lockdep_set_subclass has to be
5403 	 * *exactly* the same as the argument to init_rwsem() --- in
5404 	 * this case, in init_once() --- or lockdep gets unhappy
5405 	 * because the name of the lock is set using the
5406 	 * stringification of the argument to init_rwsem().
5407 	 */
5408 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5409 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5410 }
5411 
5412 /*
5413  * Standard function to be called on quota_on
5414  */
5415 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5416 			 const struct path *path)
5417 {
5418 	int err;
5419 
5420 	if (!test_opt(sb, QUOTA))
5421 		return -EINVAL;
5422 
5423 	/* Quotafile not on the same filesystem? */
5424 	if (path->dentry->d_sb != sb)
5425 		return -EXDEV;
5426 	/* Journaling quota? */
5427 	if (EXT4_SB(sb)->s_qf_names[type]) {
5428 		/* Quotafile not in fs root? */
5429 		if (path->dentry->d_parent != sb->s_root)
5430 			ext4_msg(sb, KERN_WARNING,
5431 				"Quota file not on filesystem root. "
5432 				"Journaled quota will not work");
5433 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5434 	} else {
5435 		/*
5436 		 * Clear the flag just in case mount options changed since
5437 		 * last time.
5438 		 */
5439 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5440 	}
5441 
5442 	/*
5443 	 * When we journal data on quota file, we have to flush journal to see
5444 	 * all updates to the file when we bypass pagecache...
5445 	 */
5446 	if (EXT4_SB(sb)->s_journal &&
5447 	    ext4_should_journal_data(d_inode(path->dentry))) {
5448 		/*
5449 		 * We don't need to lock updates but journal_flush() could
5450 		 * otherwise be livelocked...
5451 		 */
5452 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5453 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5454 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5455 		if (err)
5456 			return err;
5457 	}
5458 
5459 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5460 	err = dquot_quota_on(sb, type, format_id, path);
5461 	if (err) {
5462 		lockdep_set_quota_inode(path->dentry->d_inode,
5463 					     I_DATA_SEM_NORMAL);
5464 	} else {
5465 		struct inode *inode = d_inode(path->dentry);
5466 		handle_t *handle;
5467 
5468 		/*
5469 		 * Set inode flags to prevent userspace from messing with quota
5470 		 * files. If this fails, we return success anyway since quotas
5471 		 * are already enabled and this is not a hard failure.
5472 		 */
5473 		inode_lock(inode);
5474 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5475 		if (IS_ERR(handle))
5476 			goto unlock_inode;
5477 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5478 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5479 				S_NOATIME | S_IMMUTABLE);
5480 		ext4_mark_inode_dirty(handle, inode);
5481 		ext4_journal_stop(handle);
5482 	unlock_inode:
5483 		inode_unlock(inode);
5484 	}
5485 	return err;
5486 }
5487 
5488 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5489 			     unsigned int flags)
5490 {
5491 	int err;
5492 	struct inode *qf_inode;
5493 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5494 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5495 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5496 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5497 	};
5498 
5499 	BUG_ON(!ext4_has_feature_quota(sb));
5500 
5501 	if (!qf_inums[type])
5502 		return -EPERM;
5503 
5504 	qf_inode = ext4_iget(sb, qf_inums[type]);
5505 	if (IS_ERR(qf_inode)) {
5506 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5507 		return PTR_ERR(qf_inode);
5508 	}
5509 
5510 	/* Don't account quota for quota files to avoid recursion */
5511 	qf_inode->i_flags |= S_NOQUOTA;
5512 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5513 	err = dquot_enable(qf_inode, type, format_id, flags);
5514 	iput(qf_inode);
5515 	if (err)
5516 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5517 
5518 	return err;
5519 }
5520 
5521 /* Enable usage tracking for all quota types. */
5522 static int ext4_enable_quotas(struct super_block *sb)
5523 {
5524 	int type, err = 0;
5525 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5526 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5527 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5528 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5529 	};
5530 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5531 		test_opt(sb, USRQUOTA),
5532 		test_opt(sb, GRPQUOTA),
5533 		test_opt(sb, PRJQUOTA),
5534 	};
5535 
5536 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5537 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5538 		if (qf_inums[type]) {
5539 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5540 				DQUOT_USAGE_ENABLED |
5541 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5542 			if (err) {
5543 				for (type--; type >= 0; type--)
5544 					dquot_quota_off(sb, type);
5545 
5546 				ext4_warning(sb,
5547 					"Failed to enable quota tracking "
5548 					"(type=%d, err=%d). Please run "
5549 					"e2fsck to fix.", type, err);
5550 				return err;
5551 			}
5552 		}
5553 	}
5554 	return 0;
5555 }
5556 
5557 static int ext4_quota_off(struct super_block *sb, int type)
5558 {
5559 	struct inode *inode = sb_dqopt(sb)->files[type];
5560 	handle_t *handle;
5561 	int err;
5562 
5563 	/* Force all delayed allocation blocks to be allocated.
5564 	 * Caller already holds s_umount sem */
5565 	if (test_opt(sb, DELALLOC))
5566 		sync_filesystem(sb);
5567 
5568 	if (!inode || !igrab(inode))
5569 		goto out;
5570 
5571 	err = dquot_quota_off(sb, type);
5572 	if (err || ext4_has_feature_quota(sb))
5573 		goto out_put;
5574 
5575 	inode_lock(inode);
5576 	/*
5577 	 * Update modification times of quota files when userspace can
5578 	 * start looking at them. If we fail, we return success anyway since
5579 	 * this is not a hard failure and quotas are already disabled.
5580 	 */
5581 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5582 	if (IS_ERR(handle))
5583 		goto out_unlock;
5584 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5585 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5586 	inode->i_mtime = inode->i_ctime = current_time(inode);
5587 	ext4_mark_inode_dirty(handle, inode);
5588 	ext4_journal_stop(handle);
5589 out_unlock:
5590 	inode_unlock(inode);
5591 out_put:
5592 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5593 	iput(inode);
5594 	return err;
5595 out:
5596 	return dquot_quota_off(sb, type);
5597 }
5598 
5599 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5600  * acquiring the locks... As quota files are never truncated and quota code
5601  * itself serializes the operations (and no one else should touch the files)
5602  * we don't have to be afraid of races */
5603 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5604 			       size_t len, loff_t off)
5605 {
5606 	struct inode *inode = sb_dqopt(sb)->files[type];
5607 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5608 	int offset = off & (sb->s_blocksize - 1);
5609 	int tocopy;
5610 	size_t toread;
5611 	struct buffer_head *bh;
5612 	loff_t i_size = i_size_read(inode);
5613 
5614 	if (off > i_size)
5615 		return 0;
5616 	if (off+len > i_size)
5617 		len = i_size-off;
5618 	toread = len;
5619 	while (toread > 0) {
5620 		tocopy = sb->s_blocksize - offset < toread ?
5621 				sb->s_blocksize - offset : toread;
5622 		bh = ext4_bread(NULL, inode, blk, 0);
5623 		if (IS_ERR(bh))
5624 			return PTR_ERR(bh);
5625 		if (!bh)	/* A hole? */
5626 			memset(data, 0, tocopy);
5627 		else
5628 			memcpy(data, bh->b_data+offset, tocopy);
5629 		brelse(bh);
5630 		offset = 0;
5631 		toread -= tocopy;
5632 		data += tocopy;
5633 		blk++;
5634 	}
5635 	return len;
5636 }
5637 
5638 /* Write to quotafile (we know the transaction is already started and has
5639  * enough credits) */
5640 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5641 				const char *data, size_t len, loff_t off)
5642 {
5643 	struct inode *inode = sb_dqopt(sb)->files[type];
5644 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5645 	int err, offset = off & (sb->s_blocksize - 1);
5646 	int retries = 0;
5647 	struct buffer_head *bh;
5648 	handle_t *handle = journal_current_handle();
5649 
5650 	if (EXT4_SB(sb)->s_journal && !handle) {
5651 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5652 			" cancelled because transaction is not started",
5653 			(unsigned long long)off, (unsigned long long)len);
5654 		return -EIO;
5655 	}
5656 	/*
5657 	 * Since we account only one data block in transaction credits,
5658 	 * then it is impossible to cross a block boundary.
5659 	 */
5660 	if (sb->s_blocksize - offset < len) {
5661 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5662 			" cancelled because not block aligned",
5663 			(unsigned long long)off, (unsigned long long)len);
5664 		return -EIO;
5665 	}
5666 
5667 	do {
5668 		bh = ext4_bread(handle, inode, blk,
5669 				EXT4_GET_BLOCKS_CREATE |
5670 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5671 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5672 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5673 	if (IS_ERR(bh))
5674 		return PTR_ERR(bh);
5675 	if (!bh)
5676 		goto out;
5677 	BUFFER_TRACE(bh, "get write access");
5678 	err = ext4_journal_get_write_access(handle, bh);
5679 	if (err) {
5680 		brelse(bh);
5681 		return err;
5682 	}
5683 	lock_buffer(bh);
5684 	memcpy(bh->b_data+offset, data, len);
5685 	flush_dcache_page(bh->b_page);
5686 	unlock_buffer(bh);
5687 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5688 	brelse(bh);
5689 out:
5690 	if (inode->i_size < off + len) {
5691 		i_size_write(inode, off + len);
5692 		EXT4_I(inode)->i_disksize = inode->i_size;
5693 		ext4_mark_inode_dirty(handle, inode);
5694 	}
5695 	return len;
5696 }
5697 
5698 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5699 {
5700 	const struct quota_format_ops	*ops;
5701 
5702 	if (!sb_has_quota_loaded(sb, qid->type))
5703 		return -ESRCH;
5704 	ops = sb_dqopt(sb)->ops[qid->type];
5705 	if (!ops || !ops->get_next_id)
5706 		return -ENOSYS;
5707 	return dquot_get_next_id(sb, qid);
5708 }
5709 #endif
5710 
5711 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5712 		       const char *dev_name, void *data)
5713 {
5714 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5715 }
5716 
5717 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5718 static inline void register_as_ext2(void)
5719 {
5720 	int err = register_filesystem(&ext2_fs_type);
5721 	if (err)
5722 		printk(KERN_WARNING
5723 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5724 }
5725 
5726 static inline void unregister_as_ext2(void)
5727 {
5728 	unregister_filesystem(&ext2_fs_type);
5729 }
5730 
5731 static inline int ext2_feature_set_ok(struct super_block *sb)
5732 {
5733 	if (ext4_has_unknown_ext2_incompat_features(sb))
5734 		return 0;
5735 	if (sb_rdonly(sb))
5736 		return 1;
5737 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5738 		return 0;
5739 	return 1;
5740 }
5741 #else
5742 static inline void register_as_ext2(void) { }
5743 static inline void unregister_as_ext2(void) { }
5744 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5745 #endif
5746 
5747 static inline void register_as_ext3(void)
5748 {
5749 	int err = register_filesystem(&ext3_fs_type);
5750 	if (err)
5751 		printk(KERN_WARNING
5752 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5753 }
5754 
5755 static inline void unregister_as_ext3(void)
5756 {
5757 	unregister_filesystem(&ext3_fs_type);
5758 }
5759 
5760 static inline int ext3_feature_set_ok(struct super_block *sb)
5761 {
5762 	if (ext4_has_unknown_ext3_incompat_features(sb))
5763 		return 0;
5764 	if (!ext4_has_feature_journal(sb))
5765 		return 0;
5766 	if (sb_rdonly(sb))
5767 		return 1;
5768 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5769 		return 0;
5770 	return 1;
5771 }
5772 
5773 static struct file_system_type ext4_fs_type = {
5774 	.owner		= THIS_MODULE,
5775 	.name		= "ext4",
5776 	.mount		= ext4_mount,
5777 	.kill_sb	= kill_block_super,
5778 	.fs_flags	= FS_REQUIRES_DEV,
5779 };
5780 MODULE_ALIAS_FS("ext4");
5781 
5782 /* Shared across all ext4 file systems */
5783 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5784 
5785 static int __init ext4_init_fs(void)
5786 {
5787 	int i, err;
5788 
5789 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5790 	ext4_li_info = NULL;
5791 	mutex_init(&ext4_li_mtx);
5792 
5793 	/* Build-time check for flags consistency */
5794 	ext4_check_flag_values();
5795 
5796 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5797 		init_waitqueue_head(&ext4__ioend_wq[i]);
5798 
5799 	err = ext4_init_es();
5800 	if (err)
5801 		return err;
5802 
5803 	err = ext4_init_pageio();
5804 	if (err)
5805 		goto out5;
5806 
5807 	err = ext4_init_system_zone();
5808 	if (err)
5809 		goto out4;
5810 
5811 	err = ext4_init_sysfs();
5812 	if (err)
5813 		goto out3;
5814 
5815 	err = ext4_init_mballoc();
5816 	if (err)
5817 		goto out2;
5818 	err = init_inodecache();
5819 	if (err)
5820 		goto out1;
5821 	register_as_ext3();
5822 	register_as_ext2();
5823 	err = register_filesystem(&ext4_fs_type);
5824 	if (err)
5825 		goto out;
5826 
5827 	return 0;
5828 out:
5829 	unregister_as_ext2();
5830 	unregister_as_ext3();
5831 	destroy_inodecache();
5832 out1:
5833 	ext4_exit_mballoc();
5834 out2:
5835 	ext4_exit_sysfs();
5836 out3:
5837 	ext4_exit_system_zone();
5838 out4:
5839 	ext4_exit_pageio();
5840 out5:
5841 	ext4_exit_es();
5842 
5843 	return err;
5844 }
5845 
5846 static void __exit ext4_exit_fs(void)
5847 {
5848 	ext4_destroy_lazyinit_thread();
5849 	unregister_as_ext2();
5850 	unregister_as_ext3();
5851 	unregister_filesystem(&ext4_fs_type);
5852 	destroy_inodecache();
5853 	ext4_exit_mballoc();
5854 	ext4_exit_sysfs();
5855 	ext4_exit_system_zone();
5856 	ext4_exit_pageio();
5857 	ext4_exit_es();
5858 }
5859 
5860 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5861 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5862 MODULE_LICENSE("GPL");
5863 module_init(ext4_init_fs)
5864 module_exit(ext4_exit_fs)
5865