xref: /linux/fs/ext4/super.c (revision 6faadbbb7f9da70ce484f98f72223c20125a1009)
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->s_flags & MS_RDONLY)
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 |= MS_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 &&
591 	    (sb->s_flags & MS_RDONLY))
592 		return;
593 
594 	if (ext4_error_ratelimit(sb)) {
595 		errstr = ext4_decode_error(sb, errno, nbuf);
596 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
597 		       sb->s_id, function, line, errstr);
598 	}
599 
600 	save_error_info(sb, function, line);
601 	ext4_handle_error(sb);
602 }
603 
604 /*
605  * ext4_abort is a much stronger failure handler than ext4_error.  The
606  * abort function may be used to deal with unrecoverable failures such
607  * as journal IO errors or ENOMEM at a critical moment in log management.
608  *
609  * We unconditionally force the filesystem into an ABORT|READONLY state,
610  * unless the error response on the fs has been set to panic in which
611  * case we take the easy way out and panic immediately.
612  */
613 
614 void __ext4_abort(struct super_block *sb, const char *function,
615 		unsigned int line, const char *fmt, ...)
616 {
617 	struct va_format vaf;
618 	va_list args;
619 
620 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
621 		return;
622 
623 	save_error_info(sb, function, line);
624 	va_start(args, fmt);
625 	vaf.fmt = fmt;
626 	vaf.va = &args;
627 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
628 	       sb->s_id, function, line, &vaf);
629 	va_end(args);
630 
631 	if ((sb->s_flags & MS_RDONLY) == 0) {
632 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
633 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
634 		/*
635 		 * Make sure updated value of ->s_mount_flags will be visible
636 		 * before ->s_flags update
637 		 */
638 		smp_wmb();
639 		sb->s_flags |= MS_RDONLY;
640 		if (EXT4_SB(sb)->s_journal)
641 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
642 		save_error_info(sb, function, line);
643 	}
644 	if (test_opt(sb, ERRORS_PANIC)) {
645 		if (EXT4_SB(sb)->s_journal &&
646 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
647 			return;
648 		panic("EXT4-fs panic from previous error\n");
649 	}
650 }
651 
652 void __ext4_msg(struct super_block *sb,
653 		const char *prefix, const char *fmt, ...)
654 {
655 	struct va_format vaf;
656 	va_list args;
657 
658 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
659 		return;
660 
661 	va_start(args, fmt);
662 	vaf.fmt = fmt;
663 	vaf.va = &args;
664 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
665 	va_end(args);
666 }
667 
668 #define ext4_warning_ratelimit(sb)					\
669 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
670 			     "EXT4-fs warning")
671 
672 void __ext4_warning(struct super_block *sb, const char *function,
673 		    unsigned int line, const char *fmt, ...)
674 {
675 	struct va_format vaf;
676 	va_list args;
677 
678 	if (!ext4_warning_ratelimit(sb))
679 		return;
680 
681 	va_start(args, fmt);
682 	vaf.fmt = fmt;
683 	vaf.va = &args;
684 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
685 	       sb->s_id, function, line, &vaf);
686 	va_end(args);
687 }
688 
689 void __ext4_warning_inode(const struct inode *inode, const char *function,
690 			  unsigned int line, const char *fmt, ...)
691 {
692 	struct va_format vaf;
693 	va_list args;
694 
695 	if (!ext4_warning_ratelimit(inode->i_sb))
696 		return;
697 
698 	va_start(args, fmt);
699 	vaf.fmt = fmt;
700 	vaf.va = &args;
701 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
702 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
703 	       function, line, inode->i_ino, current->comm, &vaf);
704 	va_end(args);
705 }
706 
707 void __ext4_grp_locked_error(const char *function, unsigned int line,
708 			     struct super_block *sb, ext4_group_t grp,
709 			     unsigned long ino, ext4_fsblk_t block,
710 			     const char *fmt, ...)
711 __releases(bitlock)
712 __acquires(bitlock)
713 {
714 	struct va_format vaf;
715 	va_list args;
716 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
717 
718 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
719 		return;
720 
721 	es->s_last_error_ino = cpu_to_le32(ino);
722 	es->s_last_error_block = cpu_to_le64(block);
723 	__save_error_info(sb, function, line);
724 
725 	if (ext4_error_ratelimit(sb)) {
726 		va_start(args, fmt);
727 		vaf.fmt = fmt;
728 		vaf.va = &args;
729 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
730 		       sb->s_id, function, line, grp);
731 		if (ino)
732 			printk(KERN_CONT "inode %lu: ", ino);
733 		if (block)
734 			printk(KERN_CONT "block %llu:",
735 			       (unsigned long long) block);
736 		printk(KERN_CONT "%pV\n", &vaf);
737 		va_end(args);
738 	}
739 
740 	if (test_opt(sb, ERRORS_CONT)) {
741 		ext4_commit_super(sb, 0);
742 		return;
743 	}
744 
745 	ext4_unlock_group(sb, grp);
746 	ext4_handle_error(sb);
747 	/*
748 	 * We only get here in the ERRORS_RO case; relocking the group
749 	 * may be dangerous, but nothing bad will happen since the
750 	 * filesystem will have already been marked read/only and the
751 	 * journal has been aborted.  We return 1 as a hint to callers
752 	 * who might what to use the return value from
753 	 * ext4_grp_locked_error() to distinguish between the
754 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
755 	 * aggressively from the ext4 function in question, with a
756 	 * more appropriate error code.
757 	 */
758 	ext4_lock_group(sb, grp);
759 	return;
760 }
761 
762 void ext4_update_dynamic_rev(struct super_block *sb)
763 {
764 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
765 
766 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
767 		return;
768 
769 	ext4_warning(sb,
770 		     "updating to rev %d because of new feature flag, "
771 		     "running e2fsck is recommended",
772 		     EXT4_DYNAMIC_REV);
773 
774 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
775 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
776 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
777 	/* leave es->s_feature_*compat flags alone */
778 	/* es->s_uuid will be set by e2fsck if empty */
779 
780 	/*
781 	 * The rest of the superblock fields should be zero, and if not it
782 	 * means they are likely already in use, so leave them alone.  We
783 	 * can leave it up to e2fsck to clean up any inconsistencies there.
784 	 */
785 }
786 
787 /*
788  * Open the external journal device
789  */
790 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
791 {
792 	struct block_device *bdev;
793 	char b[BDEVNAME_SIZE];
794 
795 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
796 	if (IS_ERR(bdev))
797 		goto fail;
798 	return bdev;
799 
800 fail:
801 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
802 			__bdevname(dev, b), PTR_ERR(bdev));
803 	return NULL;
804 }
805 
806 /*
807  * Release the journal device
808  */
809 static void ext4_blkdev_put(struct block_device *bdev)
810 {
811 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
812 }
813 
814 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
815 {
816 	struct block_device *bdev;
817 	bdev = sbi->journal_bdev;
818 	if (bdev) {
819 		ext4_blkdev_put(bdev);
820 		sbi->journal_bdev = NULL;
821 	}
822 }
823 
824 static inline struct inode *orphan_list_entry(struct list_head *l)
825 {
826 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
827 }
828 
829 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
830 {
831 	struct list_head *l;
832 
833 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
834 		 le32_to_cpu(sbi->s_es->s_last_orphan));
835 
836 	printk(KERN_ERR "sb_info orphan list:\n");
837 	list_for_each(l, &sbi->s_orphan) {
838 		struct inode *inode = orphan_list_entry(l);
839 		printk(KERN_ERR "  "
840 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
841 		       inode->i_sb->s_id, inode->i_ino, inode,
842 		       inode->i_mode, inode->i_nlink,
843 		       NEXT_ORPHAN(inode));
844 	}
845 }
846 
847 #ifdef CONFIG_QUOTA
848 static int ext4_quota_off(struct super_block *sb, int type);
849 
850 static inline void ext4_quota_off_umount(struct super_block *sb)
851 {
852 	int type;
853 
854 	/* Use our quota_off function to clear inode flags etc. */
855 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
856 		ext4_quota_off(sb, type);
857 }
858 #else
859 static inline void ext4_quota_off_umount(struct super_block *sb)
860 {
861 }
862 #endif
863 
864 static void ext4_put_super(struct super_block *sb)
865 {
866 	struct ext4_sb_info *sbi = EXT4_SB(sb);
867 	struct ext4_super_block *es = sbi->s_es;
868 	int aborted = 0;
869 	int i, err;
870 
871 	ext4_unregister_li_request(sb);
872 	ext4_quota_off_umount(sb);
873 
874 	flush_workqueue(sbi->rsv_conversion_wq);
875 	destroy_workqueue(sbi->rsv_conversion_wq);
876 
877 	if (sbi->s_journal) {
878 		aborted = is_journal_aborted(sbi->s_journal);
879 		err = jbd2_journal_destroy(sbi->s_journal);
880 		sbi->s_journal = NULL;
881 		if ((err < 0) && !aborted)
882 			ext4_abort(sb, "Couldn't clean up the journal");
883 	}
884 
885 	ext4_unregister_sysfs(sb);
886 	ext4_es_unregister_shrinker(sbi);
887 	del_timer_sync(&sbi->s_err_report);
888 	ext4_release_system_zone(sb);
889 	ext4_mb_release(sb);
890 	ext4_ext_release(sb);
891 
892 	if (!(sb->s_flags & MS_RDONLY) && !aborted) {
893 		ext4_clear_feature_journal_needs_recovery(sb);
894 		es->s_state = cpu_to_le16(sbi->s_mount_state);
895 	}
896 	if (!(sb->s_flags & MS_RDONLY))
897 		ext4_commit_super(sb, 1);
898 
899 	for (i = 0; i < sbi->s_gdb_count; i++)
900 		brelse(sbi->s_group_desc[i]);
901 	kvfree(sbi->s_group_desc);
902 	kvfree(sbi->s_flex_groups);
903 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
904 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
905 	percpu_counter_destroy(&sbi->s_dirs_counter);
906 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
907 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
908 #ifdef CONFIG_QUOTA
909 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
910 		kfree(sbi->s_qf_names[i]);
911 #endif
912 
913 	/* Debugging code just in case the in-memory inode orphan list
914 	 * isn't empty.  The on-disk one can be non-empty if we've
915 	 * detected an error and taken the fs readonly, but the
916 	 * in-memory list had better be clean by this point. */
917 	if (!list_empty(&sbi->s_orphan))
918 		dump_orphan_list(sb, sbi);
919 	J_ASSERT(list_empty(&sbi->s_orphan));
920 
921 	sync_blockdev(sb->s_bdev);
922 	invalidate_bdev(sb->s_bdev);
923 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
924 		/*
925 		 * Invalidate the journal device's buffers.  We don't want them
926 		 * floating about in memory - the physical journal device may
927 		 * hotswapped, and it breaks the `ro-after' testing code.
928 		 */
929 		sync_blockdev(sbi->journal_bdev);
930 		invalidate_bdev(sbi->journal_bdev);
931 		ext4_blkdev_remove(sbi);
932 	}
933 	if (sbi->s_ea_inode_cache) {
934 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
935 		sbi->s_ea_inode_cache = NULL;
936 	}
937 	if (sbi->s_ea_block_cache) {
938 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
939 		sbi->s_ea_block_cache = NULL;
940 	}
941 	if (sbi->s_mmp_tsk)
942 		kthread_stop(sbi->s_mmp_tsk);
943 	brelse(sbi->s_sbh);
944 	sb->s_fs_info = NULL;
945 	/*
946 	 * Now that we are completely done shutting down the
947 	 * superblock, we need to actually destroy the kobject.
948 	 */
949 	kobject_put(&sbi->s_kobj);
950 	wait_for_completion(&sbi->s_kobj_unregister);
951 	if (sbi->s_chksum_driver)
952 		crypto_free_shash(sbi->s_chksum_driver);
953 	kfree(sbi->s_blockgroup_lock);
954 	fs_put_dax(sbi->s_daxdev);
955 	kfree(sbi);
956 }
957 
958 static struct kmem_cache *ext4_inode_cachep;
959 
960 /*
961  * Called inside transaction, so use GFP_NOFS
962  */
963 static struct inode *ext4_alloc_inode(struct super_block *sb)
964 {
965 	struct ext4_inode_info *ei;
966 
967 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
968 	if (!ei)
969 		return NULL;
970 
971 	ei->vfs_inode.i_version = 1;
972 	spin_lock_init(&ei->i_raw_lock);
973 	INIT_LIST_HEAD(&ei->i_prealloc_list);
974 	spin_lock_init(&ei->i_prealloc_lock);
975 	ext4_es_init_tree(&ei->i_es_tree);
976 	rwlock_init(&ei->i_es_lock);
977 	INIT_LIST_HEAD(&ei->i_es_list);
978 	ei->i_es_all_nr = 0;
979 	ei->i_es_shk_nr = 0;
980 	ei->i_es_shrink_lblk = 0;
981 	ei->i_reserved_data_blocks = 0;
982 	ei->i_da_metadata_calc_len = 0;
983 	ei->i_da_metadata_calc_last_lblock = 0;
984 	spin_lock_init(&(ei->i_block_reservation_lock));
985 #ifdef CONFIG_QUOTA
986 	ei->i_reserved_quota = 0;
987 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
988 #endif
989 	ei->jinode = NULL;
990 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
991 	spin_lock_init(&ei->i_completed_io_lock);
992 	ei->i_sync_tid = 0;
993 	ei->i_datasync_tid = 0;
994 	atomic_set(&ei->i_unwritten, 0);
995 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
996 	return &ei->vfs_inode;
997 }
998 
999 static int ext4_drop_inode(struct inode *inode)
1000 {
1001 	int drop = generic_drop_inode(inode);
1002 
1003 	trace_ext4_drop_inode(inode, drop);
1004 	return drop;
1005 }
1006 
1007 static void ext4_i_callback(struct rcu_head *head)
1008 {
1009 	struct inode *inode = container_of(head, struct inode, i_rcu);
1010 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1011 }
1012 
1013 static void ext4_destroy_inode(struct inode *inode)
1014 {
1015 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1016 		ext4_msg(inode->i_sb, KERN_ERR,
1017 			 "Inode %lu (%p): orphan list check failed!",
1018 			 inode->i_ino, EXT4_I(inode));
1019 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1020 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1021 				true);
1022 		dump_stack();
1023 	}
1024 	call_rcu(&inode->i_rcu, ext4_i_callback);
1025 }
1026 
1027 static void init_once(void *foo)
1028 {
1029 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1030 
1031 	INIT_LIST_HEAD(&ei->i_orphan);
1032 	init_rwsem(&ei->xattr_sem);
1033 	init_rwsem(&ei->i_data_sem);
1034 	init_rwsem(&ei->i_mmap_sem);
1035 	inode_init_once(&ei->vfs_inode);
1036 }
1037 
1038 static int __init init_inodecache(void)
1039 {
1040 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1041 					     sizeof(struct ext4_inode_info),
1042 					     0, (SLAB_RECLAIM_ACCOUNT|
1043 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1044 					     init_once);
1045 	if (ext4_inode_cachep == NULL)
1046 		return -ENOMEM;
1047 	return 0;
1048 }
1049 
1050 static void destroy_inodecache(void)
1051 {
1052 	/*
1053 	 * Make sure all delayed rcu free inodes are flushed before we
1054 	 * destroy cache.
1055 	 */
1056 	rcu_barrier();
1057 	kmem_cache_destroy(ext4_inode_cachep);
1058 }
1059 
1060 void ext4_clear_inode(struct inode *inode)
1061 {
1062 	invalidate_inode_buffers(inode);
1063 	clear_inode(inode);
1064 	dquot_drop(inode);
1065 	ext4_discard_preallocations(inode);
1066 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1067 	if (EXT4_I(inode)->jinode) {
1068 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1069 					       EXT4_I(inode)->jinode);
1070 		jbd2_free_inode(EXT4_I(inode)->jinode);
1071 		EXT4_I(inode)->jinode = NULL;
1072 	}
1073 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1074 	fscrypt_put_encryption_info(inode, NULL);
1075 #endif
1076 }
1077 
1078 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1079 					u64 ino, u32 generation)
1080 {
1081 	struct inode *inode;
1082 
1083 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1084 		return ERR_PTR(-ESTALE);
1085 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1086 		return ERR_PTR(-ESTALE);
1087 
1088 	/* iget isn't really right if the inode is currently unallocated!!
1089 	 *
1090 	 * ext4_read_inode will return a bad_inode if the inode had been
1091 	 * deleted, so we should be safe.
1092 	 *
1093 	 * Currently we don't know the generation for parent directory, so
1094 	 * a generation of 0 means "accept any"
1095 	 */
1096 	inode = ext4_iget_normal(sb, ino);
1097 	if (IS_ERR(inode))
1098 		return ERR_CAST(inode);
1099 	if (generation && inode->i_generation != generation) {
1100 		iput(inode);
1101 		return ERR_PTR(-ESTALE);
1102 	}
1103 
1104 	return inode;
1105 }
1106 
1107 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1108 					int fh_len, int fh_type)
1109 {
1110 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1111 				    ext4_nfs_get_inode);
1112 }
1113 
1114 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1115 					int fh_len, int fh_type)
1116 {
1117 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1118 				    ext4_nfs_get_inode);
1119 }
1120 
1121 /*
1122  * Try to release metadata pages (indirect blocks, directories) which are
1123  * mapped via the block device.  Since these pages could have journal heads
1124  * which would prevent try_to_free_buffers() from freeing them, we must use
1125  * jbd2 layer's try_to_free_buffers() function to release them.
1126  */
1127 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1128 				 gfp_t wait)
1129 {
1130 	journal_t *journal = EXT4_SB(sb)->s_journal;
1131 
1132 	WARN_ON(PageChecked(page));
1133 	if (!page_has_buffers(page))
1134 		return 0;
1135 	if (journal)
1136 		return jbd2_journal_try_to_free_buffers(journal, page,
1137 						wait & ~__GFP_DIRECT_RECLAIM);
1138 	return try_to_free_buffers(page);
1139 }
1140 
1141 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1142 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1143 {
1144 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1145 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1146 }
1147 
1148 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1149 							void *fs_data)
1150 {
1151 	handle_t *handle = fs_data;
1152 	int res, res2, credits, retries = 0;
1153 
1154 	/*
1155 	 * Encrypting the root directory is not allowed because e2fsck expects
1156 	 * lost+found to exist and be unencrypted, and encrypting the root
1157 	 * directory would imply encrypting the lost+found directory as well as
1158 	 * the filename "lost+found" itself.
1159 	 */
1160 	if (inode->i_ino == EXT4_ROOT_INO)
1161 		return -EPERM;
1162 
1163 	res = ext4_convert_inline_data(inode);
1164 	if (res)
1165 		return res;
1166 
1167 	/*
1168 	 * If a journal handle was specified, then the encryption context is
1169 	 * being set on a new inode via inheritance and is part of a larger
1170 	 * transaction to create the inode.  Otherwise the encryption context is
1171 	 * being set on an existing inode in its own transaction.  Only in the
1172 	 * latter case should the "retry on ENOSPC" logic be used.
1173 	 */
1174 
1175 	if (handle) {
1176 		res = ext4_xattr_set_handle(handle, inode,
1177 					    EXT4_XATTR_INDEX_ENCRYPTION,
1178 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1179 					    ctx, len, 0);
1180 		if (!res) {
1181 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1182 			ext4_clear_inode_state(inode,
1183 					EXT4_STATE_MAY_INLINE_DATA);
1184 			/*
1185 			 * Update inode->i_flags - e.g. S_DAX may get disabled
1186 			 */
1187 			ext4_set_inode_flags(inode);
1188 		}
1189 		return res;
1190 	}
1191 
1192 	res = dquot_initialize(inode);
1193 	if (res)
1194 		return res;
1195 retry:
1196 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1197 				     &credits);
1198 	if (res)
1199 		return res;
1200 
1201 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1202 	if (IS_ERR(handle))
1203 		return PTR_ERR(handle);
1204 
1205 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1206 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1207 				    ctx, len, 0);
1208 	if (!res) {
1209 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1210 		/* Update inode->i_flags - e.g. S_DAX may get disabled */
1211 		ext4_set_inode_flags(inode);
1212 		res = ext4_mark_inode_dirty(handle, inode);
1213 		if (res)
1214 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1215 	}
1216 	res2 = ext4_journal_stop(handle);
1217 
1218 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1219 		goto retry;
1220 	if (!res)
1221 		res = res2;
1222 	return res;
1223 }
1224 
1225 static bool ext4_dummy_context(struct inode *inode)
1226 {
1227 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1228 }
1229 
1230 static unsigned ext4_max_namelen(struct inode *inode)
1231 {
1232 	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1233 		EXT4_NAME_LEN;
1234 }
1235 
1236 static const struct fscrypt_operations ext4_cryptops = {
1237 	.key_prefix		= "ext4:",
1238 	.get_context		= ext4_get_context,
1239 	.set_context		= ext4_set_context,
1240 	.dummy_context		= ext4_dummy_context,
1241 	.is_encrypted		= ext4_encrypted_inode,
1242 	.empty_dir		= ext4_empty_dir,
1243 	.max_namelen		= ext4_max_namelen,
1244 };
1245 #else
1246 static const struct fscrypt_operations ext4_cryptops = {
1247 	.is_encrypted		= ext4_encrypted_inode,
1248 };
1249 #endif
1250 
1251 #ifdef CONFIG_QUOTA
1252 static const char * const quotatypes[] = INITQFNAMES;
1253 #define QTYPE2NAME(t) (quotatypes[t])
1254 
1255 static int ext4_write_dquot(struct dquot *dquot);
1256 static int ext4_acquire_dquot(struct dquot *dquot);
1257 static int ext4_release_dquot(struct dquot *dquot);
1258 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1259 static int ext4_write_info(struct super_block *sb, int type);
1260 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1261 			 const struct path *path);
1262 static int ext4_quota_on_mount(struct super_block *sb, int type);
1263 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1264 			       size_t len, loff_t off);
1265 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1266 				const char *data, size_t len, loff_t off);
1267 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1268 			     unsigned int flags);
1269 static int ext4_enable_quotas(struct super_block *sb);
1270 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1271 
1272 static struct dquot **ext4_get_dquots(struct inode *inode)
1273 {
1274 	return EXT4_I(inode)->i_dquot;
1275 }
1276 
1277 static const struct dquot_operations ext4_quota_operations = {
1278 	.get_reserved_space	= ext4_get_reserved_space,
1279 	.write_dquot		= ext4_write_dquot,
1280 	.acquire_dquot		= ext4_acquire_dquot,
1281 	.release_dquot		= ext4_release_dquot,
1282 	.mark_dirty		= ext4_mark_dquot_dirty,
1283 	.write_info		= ext4_write_info,
1284 	.alloc_dquot		= dquot_alloc,
1285 	.destroy_dquot		= dquot_destroy,
1286 	.get_projid		= ext4_get_projid,
1287 	.get_inode_usage	= ext4_get_inode_usage,
1288 	.get_next_id		= ext4_get_next_id,
1289 };
1290 
1291 static const struct quotactl_ops ext4_qctl_operations = {
1292 	.quota_on	= ext4_quota_on,
1293 	.quota_off	= ext4_quota_off,
1294 	.quota_sync	= dquot_quota_sync,
1295 	.get_state	= dquot_get_state,
1296 	.set_info	= dquot_set_dqinfo,
1297 	.get_dqblk	= dquot_get_dqblk,
1298 	.set_dqblk	= dquot_set_dqblk,
1299 	.get_nextdqblk	= dquot_get_next_dqblk,
1300 };
1301 #endif
1302 
1303 static const struct super_operations ext4_sops = {
1304 	.alloc_inode	= ext4_alloc_inode,
1305 	.destroy_inode	= ext4_destroy_inode,
1306 	.write_inode	= ext4_write_inode,
1307 	.dirty_inode	= ext4_dirty_inode,
1308 	.drop_inode	= ext4_drop_inode,
1309 	.evict_inode	= ext4_evict_inode,
1310 	.put_super	= ext4_put_super,
1311 	.sync_fs	= ext4_sync_fs,
1312 	.freeze_fs	= ext4_freeze,
1313 	.unfreeze_fs	= ext4_unfreeze,
1314 	.statfs		= ext4_statfs,
1315 	.remount_fs	= ext4_remount,
1316 	.show_options	= ext4_show_options,
1317 #ifdef CONFIG_QUOTA
1318 	.quota_read	= ext4_quota_read,
1319 	.quota_write	= ext4_quota_write,
1320 	.get_dquots	= ext4_get_dquots,
1321 #endif
1322 	.bdev_try_to_free_page = bdev_try_to_free_page,
1323 };
1324 
1325 static const struct export_operations ext4_export_ops = {
1326 	.fh_to_dentry = ext4_fh_to_dentry,
1327 	.fh_to_parent = ext4_fh_to_parent,
1328 	.get_parent = ext4_get_parent,
1329 };
1330 
1331 enum {
1332 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1333 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1334 	Opt_nouid32, Opt_debug, Opt_removed,
1335 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1336 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1337 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1338 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1339 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1340 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1341 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1342 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1343 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1344 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1345 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1346 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1347 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1348 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1349 	Opt_dioread_nolock, Opt_dioread_lock,
1350 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1351 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1352 };
1353 
1354 static const match_table_t tokens = {
1355 	{Opt_bsd_df, "bsddf"},
1356 	{Opt_minix_df, "minixdf"},
1357 	{Opt_grpid, "grpid"},
1358 	{Opt_grpid, "bsdgroups"},
1359 	{Opt_nogrpid, "nogrpid"},
1360 	{Opt_nogrpid, "sysvgroups"},
1361 	{Opt_resgid, "resgid=%u"},
1362 	{Opt_resuid, "resuid=%u"},
1363 	{Opt_sb, "sb=%u"},
1364 	{Opt_err_cont, "errors=continue"},
1365 	{Opt_err_panic, "errors=panic"},
1366 	{Opt_err_ro, "errors=remount-ro"},
1367 	{Opt_nouid32, "nouid32"},
1368 	{Opt_debug, "debug"},
1369 	{Opt_removed, "oldalloc"},
1370 	{Opt_removed, "orlov"},
1371 	{Opt_user_xattr, "user_xattr"},
1372 	{Opt_nouser_xattr, "nouser_xattr"},
1373 	{Opt_acl, "acl"},
1374 	{Opt_noacl, "noacl"},
1375 	{Opt_noload, "norecovery"},
1376 	{Opt_noload, "noload"},
1377 	{Opt_removed, "nobh"},
1378 	{Opt_removed, "bh"},
1379 	{Opt_commit, "commit=%u"},
1380 	{Opt_min_batch_time, "min_batch_time=%u"},
1381 	{Opt_max_batch_time, "max_batch_time=%u"},
1382 	{Opt_journal_dev, "journal_dev=%u"},
1383 	{Opt_journal_path, "journal_path=%s"},
1384 	{Opt_journal_checksum, "journal_checksum"},
1385 	{Opt_nojournal_checksum, "nojournal_checksum"},
1386 	{Opt_journal_async_commit, "journal_async_commit"},
1387 	{Opt_abort, "abort"},
1388 	{Opt_data_journal, "data=journal"},
1389 	{Opt_data_ordered, "data=ordered"},
1390 	{Opt_data_writeback, "data=writeback"},
1391 	{Opt_data_err_abort, "data_err=abort"},
1392 	{Opt_data_err_ignore, "data_err=ignore"},
1393 	{Opt_offusrjquota, "usrjquota="},
1394 	{Opt_usrjquota, "usrjquota=%s"},
1395 	{Opt_offgrpjquota, "grpjquota="},
1396 	{Opt_grpjquota, "grpjquota=%s"},
1397 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1398 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1399 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1400 	{Opt_grpquota, "grpquota"},
1401 	{Opt_noquota, "noquota"},
1402 	{Opt_quota, "quota"},
1403 	{Opt_usrquota, "usrquota"},
1404 	{Opt_prjquota, "prjquota"},
1405 	{Opt_barrier, "barrier=%u"},
1406 	{Opt_barrier, "barrier"},
1407 	{Opt_nobarrier, "nobarrier"},
1408 	{Opt_i_version, "i_version"},
1409 	{Opt_dax, "dax"},
1410 	{Opt_stripe, "stripe=%u"},
1411 	{Opt_delalloc, "delalloc"},
1412 	{Opt_lazytime, "lazytime"},
1413 	{Opt_nolazytime, "nolazytime"},
1414 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1415 	{Opt_nodelalloc, "nodelalloc"},
1416 	{Opt_removed, "mblk_io_submit"},
1417 	{Opt_removed, "nomblk_io_submit"},
1418 	{Opt_block_validity, "block_validity"},
1419 	{Opt_noblock_validity, "noblock_validity"},
1420 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1421 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1422 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1423 	{Opt_auto_da_alloc, "auto_da_alloc"},
1424 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1425 	{Opt_dioread_nolock, "dioread_nolock"},
1426 	{Opt_dioread_lock, "dioread_lock"},
1427 	{Opt_discard, "discard"},
1428 	{Opt_nodiscard, "nodiscard"},
1429 	{Opt_init_itable, "init_itable=%u"},
1430 	{Opt_init_itable, "init_itable"},
1431 	{Opt_noinit_itable, "noinit_itable"},
1432 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1433 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1434 	{Opt_nombcache, "nombcache"},
1435 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1436 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1437 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1438 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1439 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1440 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1441 	{Opt_err, NULL},
1442 };
1443 
1444 static ext4_fsblk_t get_sb_block(void **data)
1445 {
1446 	ext4_fsblk_t	sb_block;
1447 	char		*options = (char *) *data;
1448 
1449 	if (!options || strncmp(options, "sb=", 3) != 0)
1450 		return 1;	/* Default location */
1451 
1452 	options += 3;
1453 	/* TODO: use simple_strtoll with >32bit ext4 */
1454 	sb_block = simple_strtoul(options, &options, 0);
1455 	if (*options && *options != ',') {
1456 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1457 		       (char *) *data);
1458 		return 1;
1459 	}
1460 	if (*options == ',')
1461 		options++;
1462 	*data = (void *) options;
1463 
1464 	return sb_block;
1465 }
1466 
1467 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1468 static const char deprecated_msg[] =
1469 	"Mount option \"%s\" will be removed by %s\n"
1470 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1471 
1472 #ifdef CONFIG_QUOTA
1473 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1474 {
1475 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1476 	char *qname;
1477 	int ret = -1;
1478 
1479 	if (sb_any_quota_loaded(sb) &&
1480 		!sbi->s_qf_names[qtype]) {
1481 		ext4_msg(sb, KERN_ERR,
1482 			"Cannot change journaled "
1483 			"quota options when quota turned on");
1484 		return -1;
1485 	}
1486 	if (ext4_has_feature_quota(sb)) {
1487 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1488 			 "ignored when QUOTA feature is enabled");
1489 		return 1;
1490 	}
1491 	qname = match_strdup(args);
1492 	if (!qname) {
1493 		ext4_msg(sb, KERN_ERR,
1494 			"Not enough memory for storing quotafile name");
1495 		return -1;
1496 	}
1497 	if (sbi->s_qf_names[qtype]) {
1498 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1499 			ret = 1;
1500 		else
1501 			ext4_msg(sb, KERN_ERR,
1502 				 "%s quota file already specified",
1503 				 QTYPE2NAME(qtype));
1504 		goto errout;
1505 	}
1506 	if (strchr(qname, '/')) {
1507 		ext4_msg(sb, KERN_ERR,
1508 			"quotafile must be on filesystem root");
1509 		goto errout;
1510 	}
1511 	sbi->s_qf_names[qtype] = qname;
1512 	set_opt(sb, QUOTA);
1513 	return 1;
1514 errout:
1515 	kfree(qname);
1516 	return ret;
1517 }
1518 
1519 static int clear_qf_name(struct super_block *sb, int qtype)
1520 {
1521 
1522 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1523 
1524 	if (sb_any_quota_loaded(sb) &&
1525 		sbi->s_qf_names[qtype]) {
1526 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1527 			" when quota turned on");
1528 		return -1;
1529 	}
1530 	kfree(sbi->s_qf_names[qtype]);
1531 	sbi->s_qf_names[qtype] = NULL;
1532 	return 1;
1533 }
1534 #endif
1535 
1536 #define MOPT_SET	0x0001
1537 #define MOPT_CLEAR	0x0002
1538 #define MOPT_NOSUPPORT	0x0004
1539 #define MOPT_EXPLICIT	0x0008
1540 #define MOPT_CLEAR_ERR	0x0010
1541 #define MOPT_GTE0	0x0020
1542 #ifdef CONFIG_QUOTA
1543 #define MOPT_Q		0
1544 #define MOPT_QFMT	0x0040
1545 #else
1546 #define MOPT_Q		MOPT_NOSUPPORT
1547 #define MOPT_QFMT	MOPT_NOSUPPORT
1548 #endif
1549 #define MOPT_DATAJ	0x0080
1550 #define MOPT_NO_EXT2	0x0100
1551 #define MOPT_NO_EXT3	0x0200
1552 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1553 #define MOPT_STRING	0x0400
1554 
1555 static const struct mount_opts {
1556 	int	token;
1557 	int	mount_opt;
1558 	int	flags;
1559 } ext4_mount_opts[] = {
1560 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1561 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1562 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1563 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1564 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1565 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1566 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1567 	 MOPT_EXT4_ONLY | MOPT_SET},
1568 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1569 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1570 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1571 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1572 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1573 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1574 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1575 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1576 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1577 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1578 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1579 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1580 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1581 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1582 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1583 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1584 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1585 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1586 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1587 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1588 	 MOPT_NO_EXT2},
1589 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1590 	 MOPT_NO_EXT2},
1591 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1592 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1593 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1594 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1595 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1596 	{Opt_commit, 0, MOPT_GTE0},
1597 	{Opt_max_batch_time, 0, MOPT_GTE0},
1598 	{Opt_min_batch_time, 0, MOPT_GTE0},
1599 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1600 	{Opt_init_itable, 0, MOPT_GTE0},
1601 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1602 	{Opt_stripe, 0, MOPT_GTE0},
1603 	{Opt_resuid, 0, MOPT_GTE0},
1604 	{Opt_resgid, 0, MOPT_GTE0},
1605 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1606 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1607 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1608 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1609 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1610 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1611 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1612 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1613 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1614 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1615 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1616 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1617 #else
1618 	{Opt_acl, 0, MOPT_NOSUPPORT},
1619 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1620 #endif
1621 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1622 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1623 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1624 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1625 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1626 							MOPT_SET | MOPT_Q},
1627 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1628 							MOPT_SET | MOPT_Q},
1629 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1630 							MOPT_SET | MOPT_Q},
1631 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1632 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1633 							MOPT_CLEAR | MOPT_Q},
1634 	{Opt_usrjquota, 0, MOPT_Q},
1635 	{Opt_grpjquota, 0, MOPT_Q},
1636 	{Opt_offusrjquota, 0, MOPT_Q},
1637 	{Opt_offgrpjquota, 0, MOPT_Q},
1638 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1639 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1640 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1641 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1642 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1643 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1644 	{Opt_err, 0, 0}
1645 };
1646 
1647 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1648 			    substring_t *args, unsigned long *journal_devnum,
1649 			    unsigned int *journal_ioprio, int is_remount)
1650 {
1651 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1652 	const struct mount_opts *m;
1653 	kuid_t uid;
1654 	kgid_t gid;
1655 	int arg = 0;
1656 
1657 #ifdef CONFIG_QUOTA
1658 	if (token == Opt_usrjquota)
1659 		return set_qf_name(sb, USRQUOTA, &args[0]);
1660 	else if (token == Opt_grpjquota)
1661 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1662 	else if (token == Opt_offusrjquota)
1663 		return clear_qf_name(sb, USRQUOTA);
1664 	else if (token == Opt_offgrpjquota)
1665 		return clear_qf_name(sb, GRPQUOTA);
1666 #endif
1667 	switch (token) {
1668 	case Opt_noacl:
1669 	case Opt_nouser_xattr:
1670 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1671 		break;
1672 	case Opt_sb:
1673 		return 1;	/* handled by get_sb_block() */
1674 	case Opt_removed:
1675 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1676 		return 1;
1677 	case Opt_abort:
1678 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1679 		return 1;
1680 	case Opt_i_version:
1681 		sb->s_flags |= MS_I_VERSION;
1682 		return 1;
1683 	case Opt_lazytime:
1684 		sb->s_flags |= MS_LAZYTIME;
1685 		return 1;
1686 	case Opt_nolazytime:
1687 		sb->s_flags &= ~MS_LAZYTIME;
1688 		return 1;
1689 	}
1690 
1691 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1692 		if (token == m->token)
1693 			break;
1694 
1695 	if (m->token == Opt_err) {
1696 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1697 			 "or missing value", opt);
1698 		return -1;
1699 	}
1700 
1701 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1702 		ext4_msg(sb, KERN_ERR,
1703 			 "Mount option \"%s\" incompatible with ext2", opt);
1704 		return -1;
1705 	}
1706 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1707 		ext4_msg(sb, KERN_ERR,
1708 			 "Mount option \"%s\" incompatible with ext3", opt);
1709 		return -1;
1710 	}
1711 
1712 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1713 		return -1;
1714 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1715 		return -1;
1716 	if (m->flags & MOPT_EXPLICIT) {
1717 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1718 			set_opt2(sb, EXPLICIT_DELALLOC);
1719 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1720 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1721 		} else
1722 			return -1;
1723 	}
1724 	if (m->flags & MOPT_CLEAR_ERR)
1725 		clear_opt(sb, ERRORS_MASK);
1726 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1727 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1728 			 "options when quota turned on");
1729 		return -1;
1730 	}
1731 
1732 	if (m->flags & MOPT_NOSUPPORT) {
1733 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1734 	} else if (token == Opt_commit) {
1735 		if (arg == 0)
1736 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1737 		sbi->s_commit_interval = HZ * arg;
1738 	} else if (token == Opt_debug_want_extra_isize) {
1739 		sbi->s_want_extra_isize = arg;
1740 	} else if (token == Opt_max_batch_time) {
1741 		sbi->s_max_batch_time = arg;
1742 	} else if (token == Opt_min_batch_time) {
1743 		sbi->s_min_batch_time = arg;
1744 	} else if (token == Opt_inode_readahead_blks) {
1745 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1746 			ext4_msg(sb, KERN_ERR,
1747 				 "EXT4-fs: inode_readahead_blks must be "
1748 				 "0 or a power of 2 smaller than 2^31");
1749 			return -1;
1750 		}
1751 		sbi->s_inode_readahead_blks = arg;
1752 	} else if (token == Opt_init_itable) {
1753 		set_opt(sb, INIT_INODE_TABLE);
1754 		if (!args->from)
1755 			arg = EXT4_DEF_LI_WAIT_MULT;
1756 		sbi->s_li_wait_mult = arg;
1757 	} else if (token == Opt_max_dir_size_kb) {
1758 		sbi->s_max_dir_size_kb = arg;
1759 	} else if (token == Opt_stripe) {
1760 		sbi->s_stripe = arg;
1761 	} else if (token == Opt_resuid) {
1762 		uid = make_kuid(current_user_ns(), arg);
1763 		if (!uid_valid(uid)) {
1764 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1765 			return -1;
1766 		}
1767 		sbi->s_resuid = uid;
1768 	} else if (token == Opt_resgid) {
1769 		gid = make_kgid(current_user_ns(), arg);
1770 		if (!gid_valid(gid)) {
1771 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1772 			return -1;
1773 		}
1774 		sbi->s_resgid = gid;
1775 	} else if (token == Opt_journal_dev) {
1776 		if (is_remount) {
1777 			ext4_msg(sb, KERN_ERR,
1778 				 "Cannot specify journal on remount");
1779 			return -1;
1780 		}
1781 		*journal_devnum = arg;
1782 	} else if (token == Opt_journal_path) {
1783 		char *journal_path;
1784 		struct inode *journal_inode;
1785 		struct path path;
1786 		int error;
1787 
1788 		if (is_remount) {
1789 			ext4_msg(sb, KERN_ERR,
1790 				 "Cannot specify journal on remount");
1791 			return -1;
1792 		}
1793 		journal_path = match_strdup(&args[0]);
1794 		if (!journal_path) {
1795 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1796 				"journal device string");
1797 			return -1;
1798 		}
1799 
1800 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1801 		if (error) {
1802 			ext4_msg(sb, KERN_ERR, "error: could not find "
1803 				"journal device path: error %d", error);
1804 			kfree(journal_path);
1805 			return -1;
1806 		}
1807 
1808 		journal_inode = d_inode(path.dentry);
1809 		if (!S_ISBLK(journal_inode->i_mode)) {
1810 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1811 				"is not a block device", journal_path);
1812 			path_put(&path);
1813 			kfree(journal_path);
1814 			return -1;
1815 		}
1816 
1817 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1818 		path_put(&path);
1819 		kfree(journal_path);
1820 	} else if (token == Opt_journal_ioprio) {
1821 		if (arg > 7) {
1822 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1823 				 " (must be 0-7)");
1824 			return -1;
1825 		}
1826 		*journal_ioprio =
1827 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1828 	} else if (token == Opt_test_dummy_encryption) {
1829 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1830 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1831 		ext4_msg(sb, KERN_WARNING,
1832 			 "Test dummy encryption mode enabled");
1833 #else
1834 		ext4_msg(sb, KERN_WARNING,
1835 			 "Test dummy encryption mount option ignored");
1836 #endif
1837 	} else if (m->flags & MOPT_DATAJ) {
1838 		if (is_remount) {
1839 			if (!sbi->s_journal)
1840 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1841 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1842 				ext4_msg(sb, KERN_ERR,
1843 					 "Cannot change data mode on remount");
1844 				return -1;
1845 			}
1846 		} else {
1847 			clear_opt(sb, DATA_FLAGS);
1848 			sbi->s_mount_opt |= m->mount_opt;
1849 		}
1850 #ifdef CONFIG_QUOTA
1851 	} else if (m->flags & MOPT_QFMT) {
1852 		if (sb_any_quota_loaded(sb) &&
1853 		    sbi->s_jquota_fmt != m->mount_opt) {
1854 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1855 				 "quota options when quota turned on");
1856 			return -1;
1857 		}
1858 		if (ext4_has_feature_quota(sb)) {
1859 			ext4_msg(sb, KERN_INFO,
1860 				 "Quota format mount options ignored "
1861 				 "when QUOTA feature is enabled");
1862 			return 1;
1863 		}
1864 		sbi->s_jquota_fmt = m->mount_opt;
1865 #endif
1866 	} else if (token == Opt_dax) {
1867 #ifdef CONFIG_FS_DAX
1868 		ext4_msg(sb, KERN_WARNING,
1869 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1870 			sbi->s_mount_opt |= m->mount_opt;
1871 #else
1872 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1873 		return -1;
1874 #endif
1875 	} else if (token == Opt_data_err_abort) {
1876 		sbi->s_mount_opt |= m->mount_opt;
1877 	} else if (token == Opt_data_err_ignore) {
1878 		sbi->s_mount_opt &= ~m->mount_opt;
1879 	} else {
1880 		if (!args->from)
1881 			arg = 1;
1882 		if (m->flags & MOPT_CLEAR)
1883 			arg = !arg;
1884 		else if (unlikely(!(m->flags & MOPT_SET))) {
1885 			ext4_msg(sb, KERN_WARNING,
1886 				 "buggy handling of option %s", opt);
1887 			WARN_ON(1);
1888 			return -1;
1889 		}
1890 		if (arg != 0)
1891 			sbi->s_mount_opt |= m->mount_opt;
1892 		else
1893 			sbi->s_mount_opt &= ~m->mount_opt;
1894 	}
1895 	return 1;
1896 }
1897 
1898 static int parse_options(char *options, struct super_block *sb,
1899 			 unsigned long *journal_devnum,
1900 			 unsigned int *journal_ioprio,
1901 			 int is_remount)
1902 {
1903 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1904 	char *p;
1905 	substring_t args[MAX_OPT_ARGS];
1906 	int token;
1907 
1908 	if (!options)
1909 		return 1;
1910 
1911 	while ((p = strsep(&options, ",")) != NULL) {
1912 		if (!*p)
1913 			continue;
1914 		/*
1915 		 * Initialize args struct so we know whether arg was
1916 		 * found; some options take optional arguments.
1917 		 */
1918 		args[0].to = args[0].from = NULL;
1919 		token = match_token(p, tokens, args);
1920 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1921 				     journal_ioprio, is_remount) < 0)
1922 			return 0;
1923 	}
1924 #ifdef CONFIG_QUOTA
1925 	/*
1926 	 * We do the test below only for project quotas. 'usrquota' and
1927 	 * 'grpquota' mount options are allowed even without quota feature
1928 	 * to support legacy quotas in quota files.
1929 	 */
1930 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1931 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1932 			 "Cannot enable project quota enforcement.");
1933 		return 0;
1934 	}
1935 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1936 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1937 			clear_opt(sb, USRQUOTA);
1938 
1939 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1940 			clear_opt(sb, GRPQUOTA);
1941 
1942 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1943 			ext4_msg(sb, KERN_ERR, "old and new quota "
1944 					"format mixing");
1945 			return 0;
1946 		}
1947 
1948 		if (!sbi->s_jquota_fmt) {
1949 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1950 					"not specified");
1951 			return 0;
1952 		}
1953 	}
1954 #endif
1955 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1956 		int blocksize =
1957 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1958 
1959 		if (blocksize < PAGE_SIZE) {
1960 			ext4_msg(sb, KERN_ERR, "can't mount with "
1961 				 "dioread_nolock if block size != PAGE_SIZE");
1962 			return 0;
1963 		}
1964 	}
1965 	return 1;
1966 }
1967 
1968 static inline void ext4_show_quota_options(struct seq_file *seq,
1969 					   struct super_block *sb)
1970 {
1971 #if defined(CONFIG_QUOTA)
1972 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1973 
1974 	if (sbi->s_jquota_fmt) {
1975 		char *fmtname = "";
1976 
1977 		switch (sbi->s_jquota_fmt) {
1978 		case QFMT_VFS_OLD:
1979 			fmtname = "vfsold";
1980 			break;
1981 		case QFMT_VFS_V0:
1982 			fmtname = "vfsv0";
1983 			break;
1984 		case QFMT_VFS_V1:
1985 			fmtname = "vfsv1";
1986 			break;
1987 		}
1988 		seq_printf(seq, ",jqfmt=%s", fmtname);
1989 	}
1990 
1991 	if (sbi->s_qf_names[USRQUOTA])
1992 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1993 
1994 	if (sbi->s_qf_names[GRPQUOTA])
1995 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1996 #endif
1997 }
1998 
1999 static const char *token2str(int token)
2000 {
2001 	const struct match_token *t;
2002 
2003 	for (t = tokens; t->token != Opt_err; t++)
2004 		if (t->token == token && !strchr(t->pattern, '='))
2005 			break;
2006 	return t->pattern;
2007 }
2008 
2009 /*
2010  * Show an option if
2011  *  - it's set to a non-default value OR
2012  *  - if the per-sb default is different from the global default
2013  */
2014 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2015 			      int nodefs)
2016 {
2017 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2018 	struct ext4_super_block *es = sbi->s_es;
2019 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
2020 	const struct mount_opts *m;
2021 	char sep = nodefs ? '\n' : ',';
2022 
2023 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2024 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2025 
2026 	if (sbi->s_sb_block != 1)
2027 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2028 
2029 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2030 		int want_set = m->flags & MOPT_SET;
2031 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2032 		    (m->flags & MOPT_CLEAR_ERR))
2033 			continue;
2034 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2035 			continue; /* skip if same as the default */
2036 		if ((want_set &&
2037 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2038 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2039 			continue; /* select Opt_noFoo vs Opt_Foo */
2040 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2041 	}
2042 
2043 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2044 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2045 		SEQ_OPTS_PRINT("resuid=%u",
2046 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2047 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2048 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2049 		SEQ_OPTS_PRINT("resgid=%u",
2050 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2051 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2052 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2053 		SEQ_OPTS_PUTS("errors=remount-ro");
2054 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2055 		SEQ_OPTS_PUTS("errors=continue");
2056 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2057 		SEQ_OPTS_PUTS("errors=panic");
2058 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2059 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2060 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2061 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2062 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2063 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2064 	if (sb->s_flags & MS_I_VERSION)
2065 		SEQ_OPTS_PUTS("i_version");
2066 	if (nodefs || sbi->s_stripe)
2067 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2068 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2069 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2070 			SEQ_OPTS_PUTS("data=journal");
2071 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2072 			SEQ_OPTS_PUTS("data=ordered");
2073 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2074 			SEQ_OPTS_PUTS("data=writeback");
2075 	}
2076 	if (nodefs ||
2077 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2078 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2079 			       sbi->s_inode_readahead_blks);
2080 
2081 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2082 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2083 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2084 	if (nodefs || sbi->s_max_dir_size_kb)
2085 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2086 	if (test_opt(sb, DATA_ERR_ABORT))
2087 		SEQ_OPTS_PUTS("data_err=abort");
2088 
2089 	ext4_show_quota_options(seq, sb);
2090 	return 0;
2091 }
2092 
2093 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2094 {
2095 	return _ext4_show_options(seq, root->d_sb, 0);
2096 }
2097 
2098 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2099 {
2100 	struct super_block *sb = seq->private;
2101 	int rc;
2102 
2103 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2104 	rc = _ext4_show_options(seq, sb, 1);
2105 	seq_puts(seq, "\n");
2106 	return rc;
2107 }
2108 
2109 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2110 			    int read_only)
2111 {
2112 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2113 	int res = 0;
2114 
2115 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2116 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2117 			 "forcing read-only mode");
2118 		res = MS_RDONLY;
2119 	}
2120 	if (read_only)
2121 		goto done;
2122 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2123 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2124 			 "running e2fsck is recommended");
2125 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2126 		ext4_msg(sb, KERN_WARNING,
2127 			 "warning: mounting fs with errors, "
2128 			 "running e2fsck is recommended");
2129 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2130 		 le16_to_cpu(es->s_mnt_count) >=
2131 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2132 		ext4_msg(sb, KERN_WARNING,
2133 			 "warning: maximal mount count reached, "
2134 			 "running e2fsck is recommended");
2135 	else if (le32_to_cpu(es->s_checkinterval) &&
2136 		(le32_to_cpu(es->s_lastcheck) +
2137 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2138 		ext4_msg(sb, KERN_WARNING,
2139 			 "warning: checktime reached, "
2140 			 "running e2fsck is recommended");
2141 	if (!sbi->s_journal)
2142 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2143 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2144 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2145 	le16_add_cpu(&es->s_mnt_count, 1);
2146 	es->s_mtime = cpu_to_le32(get_seconds());
2147 	ext4_update_dynamic_rev(sb);
2148 	if (sbi->s_journal)
2149 		ext4_set_feature_journal_needs_recovery(sb);
2150 
2151 	ext4_commit_super(sb, 1);
2152 done:
2153 	if (test_opt(sb, DEBUG))
2154 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2155 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2156 			sb->s_blocksize,
2157 			sbi->s_groups_count,
2158 			EXT4_BLOCKS_PER_GROUP(sb),
2159 			EXT4_INODES_PER_GROUP(sb),
2160 			sbi->s_mount_opt, sbi->s_mount_opt2);
2161 
2162 	cleancache_init_fs(sb);
2163 	return res;
2164 }
2165 
2166 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2167 {
2168 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2169 	struct flex_groups *new_groups;
2170 	int size;
2171 
2172 	if (!sbi->s_log_groups_per_flex)
2173 		return 0;
2174 
2175 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2176 	if (size <= sbi->s_flex_groups_allocated)
2177 		return 0;
2178 
2179 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2180 	new_groups = kvzalloc(size, GFP_KERNEL);
2181 	if (!new_groups) {
2182 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2183 			 size / (int) sizeof(struct flex_groups));
2184 		return -ENOMEM;
2185 	}
2186 
2187 	if (sbi->s_flex_groups) {
2188 		memcpy(new_groups, sbi->s_flex_groups,
2189 		       (sbi->s_flex_groups_allocated *
2190 			sizeof(struct flex_groups)));
2191 		kvfree(sbi->s_flex_groups);
2192 	}
2193 	sbi->s_flex_groups = new_groups;
2194 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2195 	return 0;
2196 }
2197 
2198 static int ext4_fill_flex_info(struct super_block *sb)
2199 {
2200 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2201 	struct ext4_group_desc *gdp = NULL;
2202 	ext4_group_t flex_group;
2203 	int i, err;
2204 
2205 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2206 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2207 		sbi->s_log_groups_per_flex = 0;
2208 		return 1;
2209 	}
2210 
2211 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2212 	if (err)
2213 		goto failed;
2214 
2215 	for (i = 0; i < sbi->s_groups_count; i++) {
2216 		gdp = ext4_get_group_desc(sb, i, NULL);
2217 
2218 		flex_group = ext4_flex_group(sbi, i);
2219 		atomic_add(ext4_free_inodes_count(sb, gdp),
2220 			   &sbi->s_flex_groups[flex_group].free_inodes);
2221 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2222 			     &sbi->s_flex_groups[flex_group].free_clusters);
2223 		atomic_add(ext4_used_dirs_count(sb, gdp),
2224 			   &sbi->s_flex_groups[flex_group].used_dirs);
2225 	}
2226 
2227 	return 1;
2228 failed:
2229 	return 0;
2230 }
2231 
2232 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2233 				   struct ext4_group_desc *gdp)
2234 {
2235 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2236 	__u16 crc = 0;
2237 	__le32 le_group = cpu_to_le32(block_group);
2238 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2239 
2240 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2241 		/* Use new metadata_csum algorithm */
2242 		__u32 csum32;
2243 		__u16 dummy_csum = 0;
2244 
2245 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2246 				     sizeof(le_group));
2247 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2248 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2249 				     sizeof(dummy_csum));
2250 		offset += sizeof(dummy_csum);
2251 		if (offset < sbi->s_desc_size)
2252 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2253 					     sbi->s_desc_size - offset);
2254 
2255 		crc = csum32 & 0xFFFF;
2256 		goto out;
2257 	}
2258 
2259 	/* old crc16 code */
2260 	if (!ext4_has_feature_gdt_csum(sb))
2261 		return 0;
2262 
2263 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2264 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2265 	crc = crc16(crc, (__u8 *)gdp, offset);
2266 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2267 	/* for checksum of struct ext4_group_desc do the rest...*/
2268 	if (ext4_has_feature_64bit(sb) &&
2269 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2270 		crc = crc16(crc, (__u8 *)gdp + offset,
2271 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2272 				offset);
2273 
2274 out:
2275 	return cpu_to_le16(crc);
2276 }
2277 
2278 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2279 				struct ext4_group_desc *gdp)
2280 {
2281 	if (ext4_has_group_desc_csum(sb) &&
2282 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2283 		return 0;
2284 
2285 	return 1;
2286 }
2287 
2288 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2289 			      struct ext4_group_desc *gdp)
2290 {
2291 	if (!ext4_has_group_desc_csum(sb))
2292 		return;
2293 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2294 }
2295 
2296 /* Called at mount-time, super-block is locked */
2297 static int ext4_check_descriptors(struct super_block *sb,
2298 				  ext4_fsblk_t sb_block,
2299 				  ext4_group_t *first_not_zeroed)
2300 {
2301 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2302 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2303 	ext4_fsblk_t last_block;
2304 	ext4_fsblk_t block_bitmap;
2305 	ext4_fsblk_t inode_bitmap;
2306 	ext4_fsblk_t inode_table;
2307 	int flexbg_flag = 0;
2308 	ext4_group_t i, grp = sbi->s_groups_count;
2309 
2310 	if (ext4_has_feature_flex_bg(sb))
2311 		flexbg_flag = 1;
2312 
2313 	ext4_debug("Checking group descriptors");
2314 
2315 	for (i = 0; i < sbi->s_groups_count; i++) {
2316 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2317 
2318 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2319 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2320 		else
2321 			last_block = first_block +
2322 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2323 
2324 		if ((grp == sbi->s_groups_count) &&
2325 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2326 			grp = i;
2327 
2328 		block_bitmap = ext4_block_bitmap(sb, gdp);
2329 		if (block_bitmap == sb_block) {
2330 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2331 				 "Block bitmap for group %u overlaps "
2332 				 "superblock", i);
2333 		}
2334 		if (block_bitmap < first_block || block_bitmap > last_block) {
2335 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2336 			       "Block bitmap for group %u not in group "
2337 			       "(block %llu)!", i, block_bitmap);
2338 			return 0;
2339 		}
2340 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2341 		if (inode_bitmap == sb_block) {
2342 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2343 				 "Inode bitmap for group %u overlaps "
2344 				 "superblock", i);
2345 		}
2346 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2347 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2348 			       "Inode bitmap for group %u not in group "
2349 			       "(block %llu)!", i, inode_bitmap);
2350 			return 0;
2351 		}
2352 		inode_table = ext4_inode_table(sb, gdp);
2353 		if (inode_table == sb_block) {
2354 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2355 				 "Inode table for group %u overlaps "
2356 				 "superblock", i);
2357 		}
2358 		if (inode_table < first_block ||
2359 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2360 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2361 			       "Inode table for group %u not in group "
2362 			       "(block %llu)!", i, inode_table);
2363 			return 0;
2364 		}
2365 		ext4_lock_group(sb, i);
2366 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2367 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2368 				 "Checksum for group %u failed (%u!=%u)",
2369 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2370 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2371 			if (!(sb->s_flags & MS_RDONLY)) {
2372 				ext4_unlock_group(sb, i);
2373 				return 0;
2374 			}
2375 		}
2376 		ext4_unlock_group(sb, i);
2377 		if (!flexbg_flag)
2378 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2379 	}
2380 	if (NULL != first_not_zeroed)
2381 		*first_not_zeroed = grp;
2382 	return 1;
2383 }
2384 
2385 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2386  * the superblock) which were deleted from all directories, but held open by
2387  * a process at the time of a crash.  We walk the list and try to delete these
2388  * inodes at recovery time (only with a read-write filesystem).
2389  *
2390  * In order to keep the orphan inode chain consistent during traversal (in
2391  * case of crash during recovery), we link each inode into the superblock
2392  * orphan list_head and handle it the same way as an inode deletion during
2393  * normal operation (which journals the operations for us).
2394  *
2395  * We only do an iget() and an iput() on each inode, which is very safe if we
2396  * accidentally point at an in-use or already deleted inode.  The worst that
2397  * can happen in this case is that we get a "bit already cleared" message from
2398  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2399  * e2fsck was run on this filesystem, and it must have already done the orphan
2400  * inode cleanup for us, so we can safely abort without any further action.
2401  */
2402 static void ext4_orphan_cleanup(struct super_block *sb,
2403 				struct ext4_super_block *es)
2404 {
2405 	unsigned int s_flags = sb->s_flags;
2406 	int ret, nr_orphans = 0, nr_truncates = 0;
2407 #ifdef CONFIG_QUOTA
2408 	int quota_update = 0;
2409 	int i;
2410 #endif
2411 	if (!es->s_last_orphan) {
2412 		jbd_debug(4, "no orphan inodes to clean up\n");
2413 		return;
2414 	}
2415 
2416 	if (bdev_read_only(sb->s_bdev)) {
2417 		ext4_msg(sb, KERN_ERR, "write access "
2418 			"unavailable, skipping orphan cleanup");
2419 		return;
2420 	}
2421 
2422 	/* Check if feature set would not allow a r/w mount */
2423 	if (!ext4_feature_set_ok(sb, 0)) {
2424 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2425 			 "unknown ROCOMPAT features");
2426 		return;
2427 	}
2428 
2429 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2430 		/* don't clear list on RO mount w/ errors */
2431 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2432 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2433 				  "clearing orphan list.\n");
2434 			es->s_last_orphan = 0;
2435 		}
2436 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2437 		return;
2438 	}
2439 
2440 	if (s_flags & MS_RDONLY) {
2441 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2442 		sb->s_flags &= ~MS_RDONLY;
2443 	}
2444 #ifdef CONFIG_QUOTA
2445 	/* Needed for iput() to work correctly and not trash data */
2446 	sb->s_flags |= MS_ACTIVE;
2447 
2448 	/*
2449 	 * Turn on quotas which were not enabled for read-only mounts if
2450 	 * filesystem has quota feature, so that they are updated correctly.
2451 	 */
2452 	if (ext4_has_feature_quota(sb) && (s_flags & MS_RDONLY)) {
2453 		int ret = ext4_enable_quotas(sb);
2454 
2455 		if (!ret)
2456 			quota_update = 1;
2457 		else
2458 			ext4_msg(sb, KERN_ERR,
2459 				"Cannot turn on quotas: error %d", ret);
2460 	}
2461 
2462 	/* Turn on journaled quotas used for old sytle */
2463 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2464 		if (EXT4_SB(sb)->s_qf_names[i]) {
2465 			int ret = ext4_quota_on_mount(sb, i);
2466 
2467 			if (!ret)
2468 				quota_update = 1;
2469 			else
2470 				ext4_msg(sb, KERN_ERR,
2471 					"Cannot turn on journaled "
2472 					"quota: type %d: error %d", i, ret);
2473 		}
2474 	}
2475 #endif
2476 
2477 	while (es->s_last_orphan) {
2478 		struct inode *inode;
2479 
2480 		/*
2481 		 * We may have encountered an error during cleanup; if
2482 		 * so, skip the rest.
2483 		 */
2484 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2485 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2486 			es->s_last_orphan = 0;
2487 			break;
2488 		}
2489 
2490 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2491 		if (IS_ERR(inode)) {
2492 			es->s_last_orphan = 0;
2493 			break;
2494 		}
2495 
2496 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2497 		dquot_initialize(inode);
2498 		if (inode->i_nlink) {
2499 			if (test_opt(sb, DEBUG))
2500 				ext4_msg(sb, KERN_DEBUG,
2501 					"%s: truncating inode %lu to %lld bytes",
2502 					__func__, inode->i_ino, inode->i_size);
2503 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2504 				  inode->i_ino, inode->i_size);
2505 			inode_lock(inode);
2506 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2507 			ret = ext4_truncate(inode);
2508 			if (ret)
2509 				ext4_std_error(inode->i_sb, ret);
2510 			inode_unlock(inode);
2511 			nr_truncates++;
2512 		} else {
2513 			if (test_opt(sb, DEBUG))
2514 				ext4_msg(sb, KERN_DEBUG,
2515 					"%s: deleting unreferenced inode %lu",
2516 					__func__, inode->i_ino);
2517 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2518 				  inode->i_ino);
2519 			nr_orphans++;
2520 		}
2521 		iput(inode);  /* The delete magic happens here! */
2522 	}
2523 
2524 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2525 
2526 	if (nr_orphans)
2527 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2528 		       PLURAL(nr_orphans));
2529 	if (nr_truncates)
2530 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2531 		       PLURAL(nr_truncates));
2532 #ifdef CONFIG_QUOTA
2533 	/* Turn off quotas if they were enabled for orphan cleanup */
2534 	if (quota_update) {
2535 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2536 			if (sb_dqopt(sb)->files[i])
2537 				dquot_quota_off(sb, i);
2538 		}
2539 	}
2540 #endif
2541 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2542 }
2543 
2544 /*
2545  * Maximal extent format file size.
2546  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2547  * extent format containers, within a sector_t, and within i_blocks
2548  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2549  * so that won't be a limiting factor.
2550  *
2551  * However there is other limiting factor. We do store extents in the form
2552  * of starting block and length, hence the resulting length of the extent
2553  * covering maximum file size must fit into on-disk format containers as
2554  * well. Given that length is always by 1 unit bigger than max unit (because
2555  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2556  *
2557  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2558  */
2559 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2560 {
2561 	loff_t res;
2562 	loff_t upper_limit = MAX_LFS_FILESIZE;
2563 
2564 	/* small i_blocks in vfs inode? */
2565 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2566 		/*
2567 		 * CONFIG_LBDAF is not enabled implies the inode
2568 		 * i_block represent total blocks in 512 bytes
2569 		 * 32 == size of vfs inode i_blocks * 8
2570 		 */
2571 		upper_limit = (1LL << 32) - 1;
2572 
2573 		/* total blocks in file system block size */
2574 		upper_limit >>= (blkbits - 9);
2575 		upper_limit <<= blkbits;
2576 	}
2577 
2578 	/*
2579 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2580 	 * by one fs block, so ee_len can cover the extent of maximum file
2581 	 * size
2582 	 */
2583 	res = (1LL << 32) - 1;
2584 	res <<= blkbits;
2585 
2586 	/* Sanity check against vm- & vfs- imposed limits */
2587 	if (res > upper_limit)
2588 		res = upper_limit;
2589 
2590 	return res;
2591 }
2592 
2593 /*
2594  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2595  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2596  * We need to be 1 filesystem block less than the 2^48 sector limit.
2597  */
2598 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2599 {
2600 	loff_t res = EXT4_NDIR_BLOCKS;
2601 	int meta_blocks;
2602 	loff_t upper_limit;
2603 	/* This is calculated to be the largest file size for a dense, block
2604 	 * mapped file such that the file's total number of 512-byte sectors,
2605 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2606 	 *
2607 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2608 	 * number of 512-byte sectors of the file.
2609 	 */
2610 
2611 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2612 		/*
2613 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2614 		 * the inode i_block field represents total file blocks in
2615 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2616 		 */
2617 		upper_limit = (1LL << 32) - 1;
2618 
2619 		/* total blocks in file system block size */
2620 		upper_limit >>= (bits - 9);
2621 
2622 	} else {
2623 		/*
2624 		 * We use 48 bit ext4_inode i_blocks
2625 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2626 		 * represent total number of blocks in
2627 		 * file system block size
2628 		 */
2629 		upper_limit = (1LL << 48) - 1;
2630 
2631 	}
2632 
2633 	/* indirect blocks */
2634 	meta_blocks = 1;
2635 	/* double indirect blocks */
2636 	meta_blocks += 1 + (1LL << (bits-2));
2637 	/* tripple indirect blocks */
2638 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2639 
2640 	upper_limit -= meta_blocks;
2641 	upper_limit <<= bits;
2642 
2643 	res += 1LL << (bits-2);
2644 	res += 1LL << (2*(bits-2));
2645 	res += 1LL << (3*(bits-2));
2646 	res <<= bits;
2647 	if (res > upper_limit)
2648 		res = upper_limit;
2649 
2650 	if (res > MAX_LFS_FILESIZE)
2651 		res = MAX_LFS_FILESIZE;
2652 
2653 	return res;
2654 }
2655 
2656 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2657 				   ext4_fsblk_t logical_sb_block, int nr)
2658 {
2659 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2660 	ext4_group_t bg, first_meta_bg;
2661 	int has_super = 0;
2662 
2663 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2664 
2665 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2666 		return logical_sb_block + nr + 1;
2667 	bg = sbi->s_desc_per_block * nr;
2668 	if (ext4_bg_has_super(sb, bg))
2669 		has_super = 1;
2670 
2671 	/*
2672 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2673 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2674 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2675 	 * compensate.
2676 	 */
2677 	if (sb->s_blocksize == 1024 && nr == 0 &&
2678 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2679 		has_super++;
2680 
2681 	return (has_super + ext4_group_first_block_no(sb, bg));
2682 }
2683 
2684 /**
2685  * ext4_get_stripe_size: Get the stripe size.
2686  * @sbi: In memory super block info
2687  *
2688  * If we have specified it via mount option, then
2689  * use the mount option value. If the value specified at mount time is
2690  * greater than the blocks per group use the super block value.
2691  * If the super block value is greater than blocks per group return 0.
2692  * Allocator needs it be less than blocks per group.
2693  *
2694  */
2695 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2696 {
2697 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2698 	unsigned long stripe_width =
2699 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2700 	int ret;
2701 
2702 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2703 		ret = sbi->s_stripe;
2704 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2705 		ret = stripe_width;
2706 	else if (stride && stride <= sbi->s_blocks_per_group)
2707 		ret = stride;
2708 	else
2709 		ret = 0;
2710 
2711 	/*
2712 	 * If the stripe width is 1, this makes no sense and
2713 	 * we set it to 0 to turn off stripe handling code.
2714 	 */
2715 	if (ret <= 1)
2716 		ret = 0;
2717 
2718 	return ret;
2719 }
2720 
2721 /*
2722  * Check whether this filesystem can be mounted based on
2723  * the features present and the RDONLY/RDWR mount requested.
2724  * Returns 1 if this filesystem can be mounted as requested,
2725  * 0 if it cannot be.
2726  */
2727 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2728 {
2729 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2730 		ext4_msg(sb, KERN_ERR,
2731 			"Couldn't mount because of "
2732 			"unsupported optional features (%x)",
2733 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2734 			~EXT4_FEATURE_INCOMPAT_SUPP));
2735 		return 0;
2736 	}
2737 
2738 	if (readonly)
2739 		return 1;
2740 
2741 	if (ext4_has_feature_readonly(sb)) {
2742 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2743 		sb->s_flags |= MS_RDONLY;
2744 		return 1;
2745 	}
2746 
2747 	/* Check that feature set is OK for a read-write mount */
2748 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2749 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2750 			 "unsupported optional features (%x)",
2751 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2752 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2753 		return 0;
2754 	}
2755 	/*
2756 	 * Large file size enabled file system can only be mounted
2757 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2758 	 */
2759 	if (ext4_has_feature_huge_file(sb)) {
2760 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2761 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2762 				 "cannot be mounted RDWR without "
2763 				 "CONFIG_LBDAF");
2764 			return 0;
2765 		}
2766 	}
2767 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2768 		ext4_msg(sb, KERN_ERR,
2769 			 "Can't support bigalloc feature without "
2770 			 "extents feature\n");
2771 		return 0;
2772 	}
2773 
2774 #ifndef CONFIG_QUOTA
2775 	if (ext4_has_feature_quota(sb) && !readonly) {
2776 		ext4_msg(sb, KERN_ERR,
2777 			 "Filesystem with quota feature cannot be mounted RDWR "
2778 			 "without CONFIG_QUOTA");
2779 		return 0;
2780 	}
2781 	if (ext4_has_feature_project(sb) && !readonly) {
2782 		ext4_msg(sb, KERN_ERR,
2783 			 "Filesystem with project quota feature cannot be mounted RDWR "
2784 			 "without CONFIG_QUOTA");
2785 		return 0;
2786 	}
2787 #endif  /* CONFIG_QUOTA */
2788 	return 1;
2789 }
2790 
2791 /*
2792  * This function is called once a day if we have errors logged
2793  * on the file system
2794  */
2795 static void print_daily_error_info(unsigned long arg)
2796 {
2797 	struct super_block *sb = (struct super_block *) arg;
2798 	struct ext4_sb_info *sbi;
2799 	struct ext4_super_block *es;
2800 
2801 	sbi = EXT4_SB(sb);
2802 	es = sbi->s_es;
2803 
2804 	if (es->s_error_count)
2805 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2806 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2807 			 le32_to_cpu(es->s_error_count));
2808 	if (es->s_first_error_time) {
2809 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2810 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2811 		       (int) sizeof(es->s_first_error_func),
2812 		       es->s_first_error_func,
2813 		       le32_to_cpu(es->s_first_error_line));
2814 		if (es->s_first_error_ino)
2815 			printk(KERN_CONT ": inode %u",
2816 			       le32_to_cpu(es->s_first_error_ino));
2817 		if (es->s_first_error_block)
2818 			printk(KERN_CONT ": block %llu", (unsigned long long)
2819 			       le64_to_cpu(es->s_first_error_block));
2820 		printk(KERN_CONT "\n");
2821 	}
2822 	if (es->s_last_error_time) {
2823 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2824 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2825 		       (int) sizeof(es->s_last_error_func),
2826 		       es->s_last_error_func,
2827 		       le32_to_cpu(es->s_last_error_line));
2828 		if (es->s_last_error_ino)
2829 			printk(KERN_CONT ": inode %u",
2830 			       le32_to_cpu(es->s_last_error_ino));
2831 		if (es->s_last_error_block)
2832 			printk(KERN_CONT ": block %llu", (unsigned long long)
2833 			       le64_to_cpu(es->s_last_error_block));
2834 		printk(KERN_CONT "\n");
2835 	}
2836 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2837 }
2838 
2839 /* Find next suitable group and run ext4_init_inode_table */
2840 static int ext4_run_li_request(struct ext4_li_request *elr)
2841 {
2842 	struct ext4_group_desc *gdp = NULL;
2843 	ext4_group_t group, ngroups;
2844 	struct super_block *sb;
2845 	unsigned long timeout = 0;
2846 	int ret = 0;
2847 
2848 	sb = elr->lr_super;
2849 	ngroups = EXT4_SB(sb)->s_groups_count;
2850 
2851 	for (group = elr->lr_next_group; group < ngroups; group++) {
2852 		gdp = ext4_get_group_desc(sb, group, NULL);
2853 		if (!gdp) {
2854 			ret = 1;
2855 			break;
2856 		}
2857 
2858 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2859 			break;
2860 	}
2861 
2862 	if (group >= ngroups)
2863 		ret = 1;
2864 
2865 	if (!ret) {
2866 		timeout = jiffies;
2867 		ret = ext4_init_inode_table(sb, group,
2868 					    elr->lr_timeout ? 0 : 1);
2869 		if (elr->lr_timeout == 0) {
2870 			timeout = (jiffies - timeout) *
2871 				  elr->lr_sbi->s_li_wait_mult;
2872 			elr->lr_timeout = timeout;
2873 		}
2874 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2875 		elr->lr_next_group = group + 1;
2876 	}
2877 	return ret;
2878 }
2879 
2880 /*
2881  * Remove lr_request from the list_request and free the
2882  * request structure. Should be called with li_list_mtx held
2883  */
2884 static void ext4_remove_li_request(struct ext4_li_request *elr)
2885 {
2886 	struct ext4_sb_info *sbi;
2887 
2888 	if (!elr)
2889 		return;
2890 
2891 	sbi = elr->lr_sbi;
2892 
2893 	list_del(&elr->lr_request);
2894 	sbi->s_li_request = NULL;
2895 	kfree(elr);
2896 }
2897 
2898 static void ext4_unregister_li_request(struct super_block *sb)
2899 {
2900 	mutex_lock(&ext4_li_mtx);
2901 	if (!ext4_li_info) {
2902 		mutex_unlock(&ext4_li_mtx);
2903 		return;
2904 	}
2905 
2906 	mutex_lock(&ext4_li_info->li_list_mtx);
2907 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2908 	mutex_unlock(&ext4_li_info->li_list_mtx);
2909 	mutex_unlock(&ext4_li_mtx);
2910 }
2911 
2912 static struct task_struct *ext4_lazyinit_task;
2913 
2914 /*
2915  * This is the function where ext4lazyinit thread lives. It walks
2916  * through the request list searching for next scheduled filesystem.
2917  * When such a fs is found, run the lazy initialization request
2918  * (ext4_rn_li_request) and keep track of the time spend in this
2919  * function. Based on that time we compute next schedule time of
2920  * the request. When walking through the list is complete, compute
2921  * next waking time and put itself into sleep.
2922  */
2923 static int ext4_lazyinit_thread(void *arg)
2924 {
2925 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2926 	struct list_head *pos, *n;
2927 	struct ext4_li_request *elr;
2928 	unsigned long next_wakeup, cur;
2929 
2930 	BUG_ON(NULL == eli);
2931 
2932 cont_thread:
2933 	while (true) {
2934 		next_wakeup = MAX_JIFFY_OFFSET;
2935 
2936 		mutex_lock(&eli->li_list_mtx);
2937 		if (list_empty(&eli->li_request_list)) {
2938 			mutex_unlock(&eli->li_list_mtx);
2939 			goto exit_thread;
2940 		}
2941 		list_for_each_safe(pos, n, &eli->li_request_list) {
2942 			int err = 0;
2943 			int progress = 0;
2944 			elr = list_entry(pos, struct ext4_li_request,
2945 					 lr_request);
2946 
2947 			if (time_before(jiffies, elr->lr_next_sched)) {
2948 				if (time_before(elr->lr_next_sched, next_wakeup))
2949 					next_wakeup = elr->lr_next_sched;
2950 				continue;
2951 			}
2952 			if (down_read_trylock(&elr->lr_super->s_umount)) {
2953 				if (sb_start_write_trylock(elr->lr_super)) {
2954 					progress = 1;
2955 					/*
2956 					 * We hold sb->s_umount, sb can not
2957 					 * be removed from the list, it is
2958 					 * now safe to drop li_list_mtx
2959 					 */
2960 					mutex_unlock(&eli->li_list_mtx);
2961 					err = ext4_run_li_request(elr);
2962 					sb_end_write(elr->lr_super);
2963 					mutex_lock(&eli->li_list_mtx);
2964 					n = pos->next;
2965 				}
2966 				up_read((&elr->lr_super->s_umount));
2967 			}
2968 			/* error, remove the lazy_init job */
2969 			if (err) {
2970 				ext4_remove_li_request(elr);
2971 				continue;
2972 			}
2973 			if (!progress) {
2974 				elr->lr_next_sched = jiffies +
2975 					(prandom_u32()
2976 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2977 			}
2978 			if (time_before(elr->lr_next_sched, next_wakeup))
2979 				next_wakeup = elr->lr_next_sched;
2980 		}
2981 		mutex_unlock(&eli->li_list_mtx);
2982 
2983 		try_to_freeze();
2984 
2985 		cur = jiffies;
2986 		if ((time_after_eq(cur, next_wakeup)) ||
2987 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2988 			cond_resched();
2989 			continue;
2990 		}
2991 
2992 		schedule_timeout_interruptible(next_wakeup - cur);
2993 
2994 		if (kthread_should_stop()) {
2995 			ext4_clear_request_list();
2996 			goto exit_thread;
2997 		}
2998 	}
2999 
3000 exit_thread:
3001 	/*
3002 	 * It looks like the request list is empty, but we need
3003 	 * to check it under the li_list_mtx lock, to prevent any
3004 	 * additions into it, and of course we should lock ext4_li_mtx
3005 	 * to atomically free the list and ext4_li_info, because at
3006 	 * this point another ext4 filesystem could be registering
3007 	 * new one.
3008 	 */
3009 	mutex_lock(&ext4_li_mtx);
3010 	mutex_lock(&eli->li_list_mtx);
3011 	if (!list_empty(&eli->li_request_list)) {
3012 		mutex_unlock(&eli->li_list_mtx);
3013 		mutex_unlock(&ext4_li_mtx);
3014 		goto cont_thread;
3015 	}
3016 	mutex_unlock(&eli->li_list_mtx);
3017 	kfree(ext4_li_info);
3018 	ext4_li_info = NULL;
3019 	mutex_unlock(&ext4_li_mtx);
3020 
3021 	return 0;
3022 }
3023 
3024 static void ext4_clear_request_list(void)
3025 {
3026 	struct list_head *pos, *n;
3027 	struct ext4_li_request *elr;
3028 
3029 	mutex_lock(&ext4_li_info->li_list_mtx);
3030 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3031 		elr = list_entry(pos, struct ext4_li_request,
3032 				 lr_request);
3033 		ext4_remove_li_request(elr);
3034 	}
3035 	mutex_unlock(&ext4_li_info->li_list_mtx);
3036 }
3037 
3038 static int ext4_run_lazyinit_thread(void)
3039 {
3040 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3041 					 ext4_li_info, "ext4lazyinit");
3042 	if (IS_ERR(ext4_lazyinit_task)) {
3043 		int err = PTR_ERR(ext4_lazyinit_task);
3044 		ext4_clear_request_list();
3045 		kfree(ext4_li_info);
3046 		ext4_li_info = NULL;
3047 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3048 				 "initialization thread\n",
3049 				 err);
3050 		return err;
3051 	}
3052 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3053 	return 0;
3054 }
3055 
3056 /*
3057  * Check whether it make sense to run itable init. thread or not.
3058  * If there is at least one uninitialized inode table, return
3059  * corresponding group number, else the loop goes through all
3060  * groups and return total number of groups.
3061  */
3062 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3063 {
3064 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3065 	struct ext4_group_desc *gdp = NULL;
3066 
3067 	for (group = 0; group < ngroups; group++) {
3068 		gdp = ext4_get_group_desc(sb, group, NULL);
3069 		if (!gdp)
3070 			continue;
3071 
3072 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3073 			break;
3074 	}
3075 
3076 	return group;
3077 }
3078 
3079 static int ext4_li_info_new(void)
3080 {
3081 	struct ext4_lazy_init *eli = NULL;
3082 
3083 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3084 	if (!eli)
3085 		return -ENOMEM;
3086 
3087 	INIT_LIST_HEAD(&eli->li_request_list);
3088 	mutex_init(&eli->li_list_mtx);
3089 
3090 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3091 
3092 	ext4_li_info = eli;
3093 
3094 	return 0;
3095 }
3096 
3097 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3098 					    ext4_group_t start)
3099 {
3100 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3101 	struct ext4_li_request *elr;
3102 
3103 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3104 	if (!elr)
3105 		return NULL;
3106 
3107 	elr->lr_super = sb;
3108 	elr->lr_sbi = sbi;
3109 	elr->lr_next_group = start;
3110 
3111 	/*
3112 	 * Randomize first schedule time of the request to
3113 	 * spread the inode table initialization requests
3114 	 * better.
3115 	 */
3116 	elr->lr_next_sched = jiffies + (prandom_u32() %
3117 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3118 	return elr;
3119 }
3120 
3121 int ext4_register_li_request(struct super_block *sb,
3122 			     ext4_group_t first_not_zeroed)
3123 {
3124 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3125 	struct ext4_li_request *elr = NULL;
3126 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3127 	int ret = 0;
3128 
3129 	mutex_lock(&ext4_li_mtx);
3130 	if (sbi->s_li_request != NULL) {
3131 		/*
3132 		 * Reset timeout so it can be computed again, because
3133 		 * s_li_wait_mult might have changed.
3134 		 */
3135 		sbi->s_li_request->lr_timeout = 0;
3136 		goto out;
3137 	}
3138 
3139 	if (first_not_zeroed == ngroups ||
3140 	    (sb->s_flags & MS_RDONLY) ||
3141 	    !test_opt(sb, INIT_INODE_TABLE))
3142 		goto out;
3143 
3144 	elr = ext4_li_request_new(sb, first_not_zeroed);
3145 	if (!elr) {
3146 		ret = -ENOMEM;
3147 		goto out;
3148 	}
3149 
3150 	if (NULL == ext4_li_info) {
3151 		ret = ext4_li_info_new();
3152 		if (ret)
3153 			goto out;
3154 	}
3155 
3156 	mutex_lock(&ext4_li_info->li_list_mtx);
3157 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3158 	mutex_unlock(&ext4_li_info->li_list_mtx);
3159 
3160 	sbi->s_li_request = elr;
3161 	/*
3162 	 * set elr to NULL here since it has been inserted to
3163 	 * the request_list and the removal and free of it is
3164 	 * handled by ext4_clear_request_list from now on.
3165 	 */
3166 	elr = NULL;
3167 
3168 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3169 		ret = ext4_run_lazyinit_thread();
3170 		if (ret)
3171 			goto out;
3172 	}
3173 out:
3174 	mutex_unlock(&ext4_li_mtx);
3175 	if (ret)
3176 		kfree(elr);
3177 	return ret;
3178 }
3179 
3180 /*
3181  * We do not need to lock anything since this is called on
3182  * module unload.
3183  */
3184 static void ext4_destroy_lazyinit_thread(void)
3185 {
3186 	/*
3187 	 * If thread exited earlier
3188 	 * there's nothing to be done.
3189 	 */
3190 	if (!ext4_li_info || !ext4_lazyinit_task)
3191 		return;
3192 
3193 	kthread_stop(ext4_lazyinit_task);
3194 }
3195 
3196 static int set_journal_csum_feature_set(struct super_block *sb)
3197 {
3198 	int ret = 1;
3199 	int compat, incompat;
3200 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3201 
3202 	if (ext4_has_metadata_csum(sb)) {
3203 		/* journal checksum v3 */
3204 		compat = 0;
3205 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3206 	} else {
3207 		/* journal checksum v1 */
3208 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3209 		incompat = 0;
3210 	}
3211 
3212 	jbd2_journal_clear_features(sbi->s_journal,
3213 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3214 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3215 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3216 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3217 		ret = jbd2_journal_set_features(sbi->s_journal,
3218 				compat, 0,
3219 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3220 				incompat);
3221 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3222 		ret = jbd2_journal_set_features(sbi->s_journal,
3223 				compat, 0,
3224 				incompat);
3225 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3226 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3227 	} else {
3228 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3229 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3230 	}
3231 
3232 	return ret;
3233 }
3234 
3235 /*
3236  * Note: calculating the overhead so we can be compatible with
3237  * historical BSD practice is quite difficult in the face of
3238  * clusters/bigalloc.  This is because multiple metadata blocks from
3239  * different block group can end up in the same allocation cluster.
3240  * Calculating the exact overhead in the face of clustered allocation
3241  * requires either O(all block bitmaps) in memory or O(number of block
3242  * groups**2) in time.  We will still calculate the superblock for
3243  * older file systems --- and if we come across with a bigalloc file
3244  * system with zero in s_overhead_clusters the estimate will be close to
3245  * correct especially for very large cluster sizes --- but for newer
3246  * file systems, it's better to calculate this figure once at mkfs
3247  * time, and store it in the superblock.  If the superblock value is
3248  * present (even for non-bigalloc file systems), we will use it.
3249  */
3250 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3251 			  char *buf)
3252 {
3253 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3254 	struct ext4_group_desc	*gdp;
3255 	ext4_fsblk_t		first_block, last_block, b;
3256 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3257 	int			s, j, count = 0;
3258 
3259 	if (!ext4_has_feature_bigalloc(sb))
3260 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3261 			sbi->s_itb_per_group + 2);
3262 
3263 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3264 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3265 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3266 	for (i = 0; i < ngroups; i++) {
3267 		gdp = ext4_get_group_desc(sb, i, NULL);
3268 		b = ext4_block_bitmap(sb, gdp);
3269 		if (b >= first_block && b <= last_block) {
3270 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3271 			count++;
3272 		}
3273 		b = ext4_inode_bitmap(sb, gdp);
3274 		if (b >= first_block && b <= last_block) {
3275 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3276 			count++;
3277 		}
3278 		b = ext4_inode_table(sb, gdp);
3279 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3280 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3281 				int c = EXT4_B2C(sbi, b - first_block);
3282 				ext4_set_bit(c, buf);
3283 				count++;
3284 			}
3285 		if (i != grp)
3286 			continue;
3287 		s = 0;
3288 		if (ext4_bg_has_super(sb, grp)) {
3289 			ext4_set_bit(s++, buf);
3290 			count++;
3291 		}
3292 		j = ext4_bg_num_gdb(sb, grp);
3293 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3294 			ext4_error(sb, "Invalid number of block group "
3295 				   "descriptor blocks: %d", j);
3296 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3297 		}
3298 		count += j;
3299 		for (; j > 0; j--)
3300 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3301 	}
3302 	if (!count)
3303 		return 0;
3304 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3305 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3306 }
3307 
3308 /*
3309  * Compute the overhead and stash it in sbi->s_overhead
3310  */
3311 int ext4_calculate_overhead(struct super_block *sb)
3312 {
3313 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3314 	struct ext4_super_block *es = sbi->s_es;
3315 	struct inode *j_inode;
3316 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3317 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3318 	ext4_fsblk_t overhead = 0;
3319 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3320 
3321 	if (!buf)
3322 		return -ENOMEM;
3323 
3324 	/*
3325 	 * Compute the overhead (FS structures).  This is constant
3326 	 * for a given filesystem unless the number of block groups
3327 	 * changes so we cache the previous value until it does.
3328 	 */
3329 
3330 	/*
3331 	 * All of the blocks before first_data_block are overhead
3332 	 */
3333 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3334 
3335 	/*
3336 	 * Add the overhead found in each block group
3337 	 */
3338 	for (i = 0; i < ngroups; i++) {
3339 		int blks;
3340 
3341 		blks = count_overhead(sb, i, buf);
3342 		overhead += blks;
3343 		if (blks)
3344 			memset(buf, 0, PAGE_SIZE);
3345 		cond_resched();
3346 	}
3347 
3348 	/*
3349 	 * Add the internal journal blocks whether the journal has been
3350 	 * loaded or not
3351 	 */
3352 	if (sbi->s_journal && !sbi->journal_bdev)
3353 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3354 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3355 		j_inode = ext4_get_journal_inode(sb, j_inum);
3356 		if (j_inode) {
3357 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3358 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3359 			iput(j_inode);
3360 		} else {
3361 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3362 		}
3363 	}
3364 	sbi->s_overhead = overhead;
3365 	smp_wmb();
3366 	free_page((unsigned long) buf);
3367 	return 0;
3368 }
3369 
3370 static void ext4_set_resv_clusters(struct super_block *sb)
3371 {
3372 	ext4_fsblk_t resv_clusters;
3373 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3374 
3375 	/*
3376 	 * There's no need to reserve anything when we aren't using extents.
3377 	 * The space estimates are exact, there are no unwritten extents,
3378 	 * hole punching doesn't need new metadata... This is needed especially
3379 	 * to keep ext2/3 backward compatibility.
3380 	 */
3381 	if (!ext4_has_feature_extents(sb))
3382 		return;
3383 	/*
3384 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3385 	 * This should cover the situations where we can not afford to run
3386 	 * out of space like for example punch hole, or converting
3387 	 * unwritten extents in delalloc path. In most cases such
3388 	 * allocation would require 1, or 2 blocks, higher numbers are
3389 	 * very rare.
3390 	 */
3391 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3392 			 sbi->s_cluster_bits);
3393 
3394 	do_div(resv_clusters, 50);
3395 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3396 
3397 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3398 }
3399 
3400 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3401 {
3402 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3403 	char *orig_data = kstrdup(data, GFP_KERNEL);
3404 	struct buffer_head *bh;
3405 	struct ext4_super_block *es = NULL;
3406 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3407 	ext4_fsblk_t block;
3408 	ext4_fsblk_t sb_block = get_sb_block(&data);
3409 	ext4_fsblk_t logical_sb_block;
3410 	unsigned long offset = 0;
3411 	unsigned long journal_devnum = 0;
3412 	unsigned long def_mount_opts;
3413 	struct inode *root;
3414 	const char *descr;
3415 	int ret = -ENOMEM;
3416 	int blocksize, clustersize;
3417 	unsigned int db_count;
3418 	unsigned int i;
3419 	int needs_recovery, has_huge_files, has_bigalloc;
3420 	__u64 blocks_count;
3421 	int err = 0;
3422 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3423 	ext4_group_t first_not_zeroed;
3424 
3425 	if ((data && !orig_data) || !sbi)
3426 		goto out_free_base;
3427 
3428 	sbi->s_daxdev = dax_dev;
3429 	sbi->s_blockgroup_lock =
3430 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3431 	if (!sbi->s_blockgroup_lock)
3432 		goto out_free_base;
3433 
3434 	sb->s_fs_info = sbi;
3435 	sbi->s_sb = sb;
3436 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3437 	sbi->s_sb_block = sb_block;
3438 	if (sb->s_bdev->bd_part)
3439 		sbi->s_sectors_written_start =
3440 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3441 
3442 	/* Cleanup superblock name */
3443 	strreplace(sb->s_id, '/', '!');
3444 
3445 	/* -EINVAL is default */
3446 	ret = -EINVAL;
3447 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3448 	if (!blocksize) {
3449 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3450 		goto out_fail;
3451 	}
3452 
3453 	/*
3454 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3455 	 * block sizes.  We need to calculate the offset from buffer start.
3456 	 */
3457 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3458 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3459 		offset = do_div(logical_sb_block, blocksize);
3460 	} else {
3461 		logical_sb_block = sb_block;
3462 	}
3463 
3464 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3465 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3466 		goto out_fail;
3467 	}
3468 	/*
3469 	 * Note: s_es must be initialized as soon as possible because
3470 	 *       some ext4 macro-instructions depend on its value
3471 	 */
3472 	es = (struct ext4_super_block *) (bh->b_data + offset);
3473 	sbi->s_es = es;
3474 	sb->s_magic = le16_to_cpu(es->s_magic);
3475 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3476 		goto cantfind_ext4;
3477 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3478 
3479 	/* Warn if metadata_csum and gdt_csum are both set. */
3480 	if (ext4_has_feature_metadata_csum(sb) &&
3481 	    ext4_has_feature_gdt_csum(sb))
3482 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3483 			     "redundant flags; please run fsck.");
3484 
3485 	/* Check for a known checksum algorithm */
3486 	if (!ext4_verify_csum_type(sb, es)) {
3487 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3488 			 "unknown checksum algorithm.");
3489 		silent = 1;
3490 		goto cantfind_ext4;
3491 	}
3492 
3493 	/* Load the checksum driver */
3494 	if (ext4_has_feature_metadata_csum(sb) ||
3495 	    ext4_has_feature_ea_inode(sb)) {
3496 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3497 		if (IS_ERR(sbi->s_chksum_driver)) {
3498 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3499 			ret = PTR_ERR(sbi->s_chksum_driver);
3500 			sbi->s_chksum_driver = NULL;
3501 			goto failed_mount;
3502 		}
3503 	}
3504 
3505 	/* Check superblock checksum */
3506 	if (!ext4_superblock_csum_verify(sb, es)) {
3507 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3508 			 "invalid superblock checksum.  Run e2fsck?");
3509 		silent = 1;
3510 		ret = -EFSBADCRC;
3511 		goto cantfind_ext4;
3512 	}
3513 
3514 	/* Precompute checksum seed for all metadata */
3515 	if (ext4_has_feature_csum_seed(sb))
3516 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3517 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3518 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3519 					       sizeof(es->s_uuid));
3520 
3521 	/* Set defaults before we parse the mount options */
3522 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3523 	set_opt(sb, INIT_INODE_TABLE);
3524 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3525 		set_opt(sb, DEBUG);
3526 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3527 		set_opt(sb, GRPID);
3528 	if (def_mount_opts & EXT4_DEFM_UID16)
3529 		set_opt(sb, NO_UID32);
3530 	/* xattr user namespace & acls are now defaulted on */
3531 	set_opt(sb, XATTR_USER);
3532 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3533 	set_opt(sb, POSIX_ACL);
3534 #endif
3535 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3536 	if (ext4_has_metadata_csum(sb))
3537 		set_opt(sb, JOURNAL_CHECKSUM);
3538 
3539 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3540 		set_opt(sb, JOURNAL_DATA);
3541 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3542 		set_opt(sb, ORDERED_DATA);
3543 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3544 		set_opt(sb, WRITEBACK_DATA);
3545 
3546 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3547 		set_opt(sb, ERRORS_PANIC);
3548 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3549 		set_opt(sb, ERRORS_CONT);
3550 	else
3551 		set_opt(sb, ERRORS_RO);
3552 	/* block_validity enabled by default; disable with noblock_validity */
3553 	set_opt(sb, BLOCK_VALIDITY);
3554 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3555 		set_opt(sb, DISCARD);
3556 
3557 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3558 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3559 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3560 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3561 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3562 
3563 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3564 		set_opt(sb, BARRIER);
3565 
3566 	/*
3567 	 * enable delayed allocation by default
3568 	 * Use -o nodelalloc to turn it off
3569 	 */
3570 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3571 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3572 		set_opt(sb, DELALLOC);
3573 
3574 	/*
3575 	 * set default s_li_wait_mult for lazyinit, for the case there is
3576 	 * no mount option specified.
3577 	 */
3578 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3579 
3580 	if (sbi->s_es->s_mount_opts[0]) {
3581 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3582 					      sizeof(sbi->s_es->s_mount_opts),
3583 					      GFP_KERNEL);
3584 		if (!s_mount_opts)
3585 			goto failed_mount;
3586 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3587 				   &journal_ioprio, 0)) {
3588 			ext4_msg(sb, KERN_WARNING,
3589 				 "failed to parse options in superblock: %s",
3590 				 s_mount_opts);
3591 		}
3592 		kfree(s_mount_opts);
3593 	}
3594 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3595 	if (!parse_options((char *) data, sb, &journal_devnum,
3596 			   &journal_ioprio, 0))
3597 		goto failed_mount;
3598 
3599 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3600 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3601 			    "with data=journal disables delayed "
3602 			    "allocation and O_DIRECT support!\n");
3603 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3604 			ext4_msg(sb, KERN_ERR, "can't mount with "
3605 				 "both data=journal and delalloc");
3606 			goto failed_mount;
3607 		}
3608 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3609 			ext4_msg(sb, KERN_ERR, "can't mount with "
3610 				 "both data=journal and dioread_nolock");
3611 			goto failed_mount;
3612 		}
3613 		if (test_opt(sb, DAX)) {
3614 			ext4_msg(sb, KERN_ERR, "can't mount with "
3615 				 "both data=journal and dax");
3616 			goto failed_mount;
3617 		}
3618 		if (ext4_has_feature_encrypt(sb)) {
3619 			ext4_msg(sb, KERN_WARNING,
3620 				 "encrypted files will use data=ordered "
3621 				 "instead of data journaling mode");
3622 		}
3623 		if (test_opt(sb, DELALLOC))
3624 			clear_opt(sb, DELALLOC);
3625 	} else {
3626 		sb->s_iflags |= SB_I_CGROUPWB;
3627 	}
3628 
3629 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3630 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3631 
3632 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3633 	    (ext4_has_compat_features(sb) ||
3634 	     ext4_has_ro_compat_features(sb) ||
3635 	     ext4_has_incompat_features(sb)))
3636 		ext4_msg(sb, KERN_WARNING,
3637 		       "feature flags set on rev 0 fs, "
3638 		       "running e2fsck is recommended");
3639 
3640 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3641 		set_opt2(sb, HURD_COMPAT);
3642 		if (ext4_has_feature_64bit(sb)) {
3643 			ext4_msg(sb, KERN_ERR,
3644 				 "The Hurd can't support 64-bit file systems");
3645 			goto failed_mount;
3646 		}
3647 
3648 		/*
3649 		 * ea_inode feature uses l_i_version field which is not
3650 		 * available in HURD_COMPAT mode.
3651 		 */
3652 		if (ext4_has_feature_ea_inode(sb)) {
3653 			ext4_msg(sb, KERN_ERR,
3654 				 "ea_inode feature is not supported for Hurd");
3655 			goto failed_mount;
3656 		}
3657 	}
3658 
3659 	if (IS_EXT2_SB(sb)) {
3660 		if (ext2_feature_set_ok(sb))
3661 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3662 				 "using the ext4 subsystem");
3663 		else {
3664 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3665 				 "to feature incompatibilities");
3666 			goto failed_mount;
3667 		}
3668 	}
3669 
3670 	if (IS_EXT3_SB(sb)) {
3671 		if (ext3_feature_set_ok(sb))
3672 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3673 				 "using the ext4 subsystem");
3674 		else {
3675 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3676 				 "to feature incompatibilities");
3677 			goto failed_mount;
3678 		}
3679 	}
3680 
3681 	/*
3682 	 * Check feature flags regardless of the revision level, since we
3683 	 * previously didn't change the revision level when setting the flags,
3684 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3685 	 */
3686 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3687 		goto failed_mount;
3688 
3689 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3690 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3691 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3692 		ext4_msg(sb, KERN_ERR,
3693 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3694 			 blocksize, le32_to_cpu(es->s_log_block_size));
3695 		goto failed_mount;
3696 	}
3697 	if (le32_to_cpu(es->s_log_block_size) >
3698 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3699 		ext4_msg(sb, KERN_ERR,
3700 			 "Invalid log block size: %u",
3701 			 le32_to_cpu(es->s_log_block_size));
3702 		goto failed_mount;
3703 	}
3704 
3705 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3706 		ext4_msg(sb, KERN_ERR,
3707 			 "Number of reserved GDT blocks insanely large: %d",
3708 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3709 		goto failed_mount;
3710 	}
3711 
3712 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3713 		err = bdev_dax_supported(sb, blocksize);
3714 		if (err)
3715 			goto failed_mount;
3716 	}
3717 
3718 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3719 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3720 			 es->s_encryption_level);
3721 		goto failed_mount;
3722 	}
3723 
3724 	if (sb->s_blocksize != blocksize) {
3725 		/* Validate the filesystem blocksize */
3726 		if (!sb_set_blocksize(sb, blocksize)) {
3727 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3728 					blocksize);
3729 			goto failed_mount;
3730 		}
3731 
3732 		brelse(bh);
3733 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3734 		offset = do_div(logical_sb_block, blocksize);
3735 		bh = sb_bread_unmovable(sb, logical_sb_block);
3736 		if (!bh) {
3737 			ext4_msg(sb, KERN_ERR,
3738 			       "Can't read superblock on 2nd try");
3739 			goto failed_mount;
3740 		}
3741 		es = (struct ext4_super_block *)(bh->b_data + offset);
3742 		sbi->s_es = es;
3743 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3744 			ext4_msg(sb, KERN_ERR,
3745 			       "Magic mismatch, very weird!");
3746 			goto failed_mount;
3747 		}
3748 	}
3749 
3750 	has_huge_files = ext4_has_feature_huge_file(sb);
3751 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3752 						      has_huge_files);
3753 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3754 
3755 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3756 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3757 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3758 	} else {
3759 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3760 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3761 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3762 		    (!is_power_of_2(sbi->s_inode_size)) ||
3763 		    (sbi->s_inode_size > blocksize)) {
3764 			ext4_msg(sb, KERN_ERR,
3765 			       "unsupported inode size: %d",
3766 			       sbi->s_inode_size);
3767 			goto failed_mount;
3768 		}
3769 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3770 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3771 	}
3772 
3773 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3774 	if (ext4_has_feature_64bit(sb)) {
3775 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3776 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3777 		    !is_power_of_2(sbi->s_desc_size)) {
3778 			ext4_msg(sb, KERN_ERR,
3779 			       "unsupported descriptor size %lu",
3780 			       sbi->s_desc_size);
3781 			goto failed_mount;
3782 		}
3783 	} else
3784 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3785 
3786 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3787 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3788 
3789 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3790 	if (sbi->s_inodes_per_block == 0)
3791 		goto cantfind_ext4;
3792 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3793 	    sbi->s_inodes_per_group > blocksize * 8) {
3794 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3795 			 sbi->s_blocks_per_group);
3796 		goto failed_mount;
3797 	}
3798 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3799 					sbi->s_inodes_per_block;
3800 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3801 	sbi->s_sbh = bh;
3802 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3803 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3804 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3805 
3806 	for (i = 0; i < 4; i++)
3807 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3808 	sbi->s_def_hash_version = es->s_def_hash_version;
3809 	if (ext4_has_feature_dir_index(sb)) {
3810 		i = le32_to_cpu(es->s_flags);
3811 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3812 			sbi->s_hash_unsigned = 3;
3813 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3814 #ifdef __CHAR_UNSIGNED__
3815 			if (!(sb->s_flags & MS_RDONLY))
3816 				es->s_flags |=
3817 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3818 			sbi->s_hash_unsigned = 3;
3819 #else
3820 			if (!(sb->s_flags & MS_RDONLY))
3821 				es->s_flags |=
3822 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3823 #endif
3824 		}
3825 	}
3826 
3827 	/* Handle clustersize */
3828 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3829 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3830 	if (has_bigalloc) {
3831 		if (clustersize < blocksize) {
3832 			ext4_msg(sb, KERN_ERR,
3833 				 "cluster size (%d) smaller than "
3834 				 "block size (%d)", clustersize, blocksize);
3835 			goto failed_mount;
3836 		}
3837 		if (le32_to_cpu(es->s_log_cluster_size) >
3838 		    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3839 			ext4_msg(sb, KERN_ERR,
3840 				 "Invalid log cluster size: %u",
3841 				 le32_to_cpu(es->s_log_cluster_size));
3842 			goto failed_mount;
3843 		}
3844 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3845 			le32_to_cpu(es->s_log_block_size);
3846 		sbi->s_clusters_per_group =
3847 			le32_to_cpu(es->s_clusters_per_group);
3848 		if (sbi->s_clusters_per_group > blocksize * 8) {
3849 			ext4_msg(sb, KERN_ERR,
3850 				 "#clusters per group too big: %lu",
3851 				 sbi->s_clusters_per_group);
3852 			goto failed_mount;
3853 		}
3854 		if (sbi->s_blocks_per_group !=
3855 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3856 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3857 				 "clusters per group (%lu) inconsistent",
3858 				 sbi->s_blocks_per_group,
3859 				 sbi->s_clusters_per_group);
3860 			goto failed_mount;
3861 		}
3862 	} else {
3863 		if (clustersize != blocksize) {
3864 			ext4_warning(sb, "fragment/cluster size (%d) != "
3865 				     "block size (%d)", clustersize,
3866 				     blocksize);
3867 			clustersize = blocksize;
3868 		}
3869 		if (sbi->s_blocks_per_group > blocksize * 8) {
3870 			ext4_msg(sb, KERN_ERR,
3871 				 "#blocks per group too big: %lu",
3872 				 sbi->s_blocks_per_group);
3873 			goto failed_mount;
3874 		}
3875 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3876 		sbi->s_cluster_bits = 0;
3877 	}
3878 	sbi->s_cluster_ratio = clustersize / blocksize;
3879 
3880 	/* Do we have standard group size of clustersize * 8 blocks ? */
3881 	if (sbi->s_blocks_per_group == clustersize << 3)
3882 		set_opt2(sb, STD_GROUP_SIZE);
3883 
3884 	/*
3885 	 * Test whether we have more sectors than will fit in sector_t,
3886 	 * and whether the max offset is addressable by the page cache.
3887 	 */
3888 	err = generic_check_addressable(sb->s_blocksize_bits,
3889 					ext4_blocks_count(es));
3890 	if (err) {
3891 		ext4_msg(sb, KERN_ERR, "filesystem"
3892 			 " too large to mount safely on this system");
3893 		if (sizeof(sector_t) < 8)
3894 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3895 		goto failed_mount;
3896 	}
3897 
3898 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3899 		goto cantfind_ext4;
3900 
3901 	/* check blocks count against device size */
3902 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3903 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3904 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3905 		       "exceeds size of device (%llu blocks)",
3906 		       ext4_blocks_count(es), blocks_count);
3907 		goto failed_mount;
3908 	}
3909 
3910 	/*
3911 	 * It makes no sense for the first data block to be beyond the end
3912 	 * of the filesystem.
3913 	 */
3914 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3915 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3916 			 "block %u is beyond end of filesystem (%llu)",
3917 			 le32_to_cpu(es->s_first_data_block),
3918 			 ext4_blocks_count(es));
3919 		goto failed_mount;
3920 	}
3921 	blocks_count = (ext4_blocks_count(es) -
3922 			le32_to_cpu(es->s_first_data_block) +
3923 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3924 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3925 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3926 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3927 		       "(block count %llu, first data block %u, "
3928 		       "blocks per group %lu)", sbi->s_groups_count,
3929 		       ext4_blocks_count(es),
3930 		       le32_to_cpu(es->s_first_data_block),
3931 		       EXT4_BLOCKS_PER_GROUP(sb));
3932 		goto failed_mount;
3933 	}
3934 	sbi->s_groups_count = blocks_count;
3935 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3936 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3937 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3938 		   EXT4_DESC_PER_BLOCK(sb);
3939 	if (ext4_has_feature_meta_bg(sb)) {
3940 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3941 			ext4_msg(sb, KERN_WARNING,
3942 				 "first meta block group too large: %u "
3943 				 "(group descriptor block count %u)",
3944 				 le32_to_cpu(es->s_first_meta_bg), db_count);
3945 			goto failed_mount;
3946 		}
3947 	}
3948 	sbi->s_group_desc = kvmalloc(db_count *
3949 					  sizeof(struct buffer_head *),
3950 					  GFP_KERNEL);
3951 	if (sbi->s_group_desc == NULL) {
3952 		ext4_msg(sb, KERN_ERR, "not enough memory");
3953 		ret = -ENOMEM;
3954 		goto failed_mount;
3955 	}
3956 
3957 	bgl_lock_init(sbi->s_blockgroup_lock);
3958 
3959 	/* Pre-read the descriptors into the buffer cache */
3960 	for (i = 0; i < db_count; i++) {
3961 		block = descriptor_loc(sb, logical_sb_block, i);
3962 		sb_breadahead(sb, block);
3963 	}
3964 
3965 	for (i = 0; i < db_count; i++) {
3966 		block = descriptor_loc(sb, logical_sb_block, i);
3967 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3968 		if (!sbi->s_group_desc[i]) {
3969 			ext4_msg(sb, KERN_ERR,
3970 			       "can't read group descriptor %d", i);
3971 			db_count = i;
3972 			goto failed_mount2;
3973 		}
3974 	}
3975 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3976 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3977 		ret = -EFSCORRUPTED;
3978 		goto failed_mount2;
3979 	}
3980 
3981 	sbi->s_gdb_count = db_count;
3982 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3983 	spin_lock_init(&sbi->s_next_gen_lock);
3984 
3985 	setup_timer(&sbi->s_err_report, print_daily_error_info,
3986 		(unsigned long) sb);
3987 
3988 	/* Register extent status tree shrinker */
3989 	if (ext4_es_register_shrinker(sbi))
3990 		goto failed_mount3;
3991 
3992 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3993 	sbi->s_extent_max_zeroout_kb = 32;
3994 
3995 	/*
3996 	 * set up enough so that it can read an inode
3997 	 */
3998 	sb->s_op = &ext4_sops;
3999 	sb->s_export_op = &ext4_export_ops;
4000 	sb->s_xattr = ext4_xattr_handlers;
4001 	sb->s_cop = &ext4_cryptops;
4002 #ifdef CONFIG_QUOTA
4003 	sb->dq_op = &ext4_quota_operations;
4004 	if (ext4_has_feature_quota(sb))
4005 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4006 	else
4007 		sb->s_qcop = &ext4_qctl_operations;
4008 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4009 #endif
4010 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4011 
4012 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4013 	mutex_init(&sbi->s_orphan_lock);
4014 
4015 	sb->s_root = NULL;
4016 
4017 	needs_recovery = (es->s_last_orphan != 0 ||
4018 			  ext4_has_feature_journal_needs_recovery(sb));
4019 
4020 	if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
4021 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4022 			goto failed_mount3a;
4023 
4024 	/*
4025 	 * The first inode we look at is the journal inode.  Don't try
4026 	 * root first: it may be modified in the journal!
4027 	 */
4028 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4029 		err = ext4_load_journal(sb, es, journal_devnum);
4030 		if (err)
4031 			goto failed_mount3a;
4032 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
4033 		   ext4_has_feature_journal_needs_recovery(sb)) {
4034 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4035 		       "suppressed and not mounted read-only");
4036 		goto failed_mount_wq;
4037 	} else {
4038 		/* Nojournal mode, all journal mount options are illegal */
4039 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4040 			ext4_msg(sb, KERN_ERR, "can't mount with "
4041 				 "journal_checksum, fs mounted w/o journal");
4042 			goto failed_mount_wq;
4043 		}
4044 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4045 			ext4_msg(sb, KERN_ERR, "can't mount with "
4046 				 "journal_async_commit, fs mounted w/o journal");
4047 			goto failed_mount_wq;
4048 		}
4049 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4050 			ext4_msg(sb, KERN_ERR, "can't mount with "
4051 				 "commit=%lu, fs mounted w/o journal",
4052 				 sbi->s_commit_interval / HZ);
4053 			goto failed_mount_wq;
4054 		}
4055 		if (EXT4_MOUNT_DATA_FLAGS &
4056 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4057 			ext4_msg(sb, KERN_ERR, "can't mount with "
4058 				 "data=, fs mounted w/o journal");
4059 			goto failed_mount_wq;
4060 		}
4061 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4062 		clear_opt(sb, JOURNAL_CHECKSUM);
4063 		clear_opt(sb, DATA_FLAGS);
4064 		sbi->s_journal = NULL;
4065 		needs_recovery = 0;
4066 		goto no_journal;
4067 	}
4068 
4069 	if (ext4_has_feature_64bit(sb) &&
4070 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4071 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4072 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4073 		goto failed_mount_wq;
4074 	}
4075 
4076 	if (!set_journal_csum_feature_set(sb)) {
4077 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4078 			 "feature set");
4079 		goto failed_mount_wq;
4080 	}
4081 
4082 	/* We have now updated the journal if required, so we can
4083 	 * validate the data journaling mode. */
4084 	switch (test_opt(sb, DATA_FLAGS)) {
4085 	case 0:
4086 		/* No mode set, assume a default based on the journal
4087 		 * capabilities: ORDERED_DATA if the journal can
4088 		 * cope, else JOURNAL_DATA
4089 		 */
4090 		if (jbd2_journal_check_available_features
4091 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4092 			set_opt(sb, ORDERED_DATA);
4093 		else
4094 			set_opt(sb, JOURNAL_DATA);
4095 		break;
4096 
4097 	case EXT4_MOUNT_ORDERED_DATA:
4098 	case EXT4_MOUNT_WRITEBACK_DATA:
4099 		if (!jbd2_journal_check_available_features
4100 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4101 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4102 			       "requested data journaling mode");
4103 			goto failed_mount_wq;
4104 		}
4105 	default:
4106 		break;
4107 	}
4108 
4109 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4110 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4111 		ext4_msg(sb, KERN_ERR, "can't mount with "
4112 			"journal_async_commit in data=ordered mode");
4113 		goto failed_mount_wq;
4114 	}
4115 
4116 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4117 
4118 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4119 
4120 no_journal:
4121 	if (!test_opt(sb, NO_MBCACHE)) {
4122 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4123 		if (!sbi->s_ea_block_cache) {
4124 			ext4_msg(sb, KERN_ERR,
4125 				 "Failed to create ea_block_cache");
4126 			goto failed_mount_wq;
4127 		}
4128 
4129 		if (ext4_has_feature_ea_inode(sb)) {
4130 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4131 			if (!sbi->s_ea_inode_cache) {
4132 				ext4_msg(sb, KERN_ERR,
4133 					 "Failed to create ea_inode_cache");
4134 				goto failed_mount_wq;
4135 			}
4136 		}
4137 	}
4138 
4139 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4140 	    (blocksize != PAGE_SIZE)) {
4141 		ext4_msg(sb, KERN_ERR,
4142 			 "Unsupported blocksize for fs encryption");
4143 		goto failed_mount_wq;
4144 	}
4145 
4146 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
4147 	    !ext4_has_feature_encrypt(sb)) {
4148 		ext4_set_feature_encrypt(sb);
4149 		ext4_commit_super(sb, 1);
4150 	}
4151 
4152 	/*
4153 	 * Get the # of file system overhead blocks from the
4154 	 * superblock if present.
4155 	 */
4156 	if (es->s_overhead_clusters)
4157 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4158 	else {
4159 		err = ext4_calculate_overhead(sb);
4160 		if (err)
4161 			goto failed_mount_wq;
4162 	}
4163 
4164 	/*
4165 	 * The maximum number of concurrent works can be high and
4166 	 * concurrency isn't really necessary.  Limit it to 1.
4167 	 */
4168 	EXT4_SB(sb)->rsv_conversion_wq =
4169 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4170 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4171 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4172 		ret = -ENOMEM;
4173 		goto failed_mount4;
4174 	}
4175 
4176 	/*
4177 	 * The jbd2_journal_load will have done any necessary log recovery,
4178 	 * so we can safely mount the rest of the filesystem now.
4179 	 */
4180 
4181 	root = ext4_iget(sb, EXT4_ROOT_INO);
4182 	if (IS_ERR(root)) {
4183 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4184 		ret = PTR_ERR(root);
4185 		root = NULL;
4186 		goto failed_mount4;
4187 	}
4188 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4189 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4190 		iput(root);
4191 		goto failed_mount4;
4192 	}
4193 	sb->s_root = d_make_root(root);
4194 	if (!sb->s_root) {
4195 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4196 		ret = -ENOMEM;
4197 		goto failed_mount4;
4198 	}
4199 
4200 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4201 		sb->s_flags |= MS_RDONLY;
4202 
4203 	/* determine the minimum size of new large inodes, if present */
4204 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4205 	    sbi->s_want_extra_isize == 0) {
4206 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4207 						     EXT4_GOOD_OLD_INODE_SIZE;
4208 		if (ext4_has_feature_extra_isize(sb)) {
4209 			if (sbi->s_want_extra_isize <
4210 			    le16_to_cpu(es->s_want_extra_isize))
4211 				sbi->s_want_extra_isize =
4212 					le16_to_cpu(es->s_want_extra_isize);
4213 			if (sbi->s_want_extra_isize <
4214 			    le16_to_cpu(es->s_min_extra_isize))
4215 				sbi->s_want_extra_isize =
4216 					le16_to_cpu(es->s_min_extra_isize);
4217 		}
4218 	}
4219 	/* Check if enough inode space is available */
4220 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4221 							sbi->s_inode_size) {
4222 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4223 						       EXT4_GOOD_OLD_INODE_SIZE;
4224 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4225 			 "available");
4226 	}
4227 
4228 	ext4_set_resv_clusters(sb);
4229 
4230 	err = ext4_setup_system_zone(sb);
4231 	if (err) {
4232 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4233 			 "zone (%d)", err);
4234 		goto failed_mount4a;
4235 	}
4236 
4237 	ext4_ext_init(sb);
4238 	err = ext4_mb_init(sb);
4239 	if (err) {
4240 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4241 			 err);
4242 		goto failed_mount5;
4243 	}
4244 
4245 	block = ext4_count_free_clusters(sb);
4246 	ext4_free_blocks_count_set(sbi->s_es,
4247 				   EXT4_C2B(sbi, block));
4248 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4249 				  GFP_KERNEL);
4250 	if (!err) {
4251 		unsigned long freei = ext4_count_free_inodes(sb);
4252 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4253 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4254 					  GFP_KERNEL);
4255 	}
4256 	if (!err)
4257 		err = percpu_counter_init(&sbi->s_dirs_counter,
4258 					  ext4_count_dirs(sb), GFP_KERNEL);
4259 	if (!err)
4260 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4261 					  GFP_KERNEL);
4262 	if (!err)
4263 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4264 
4265 	if (err) {
4266 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4267 		goto failed_mount6;
4268 	}
4269 
4270 	if (ext4_has_feature_flex_bg(sb))
4271 		if (!ext4_fill_flex_info(sb)) {
4272 			ext4_msg(sb, KERN_ERR,
4273 			       "unable to initialize "
4274 			       "flex_bg meta info!");
4275 			goto failed_mount6;
4276 		}
4277 
4278 	err = ext4_register_li_request(sb, first_not_zeroed);
4279 	if (err)
4280 		goto failed_mount6;
4281 
4282 	err = ext4_register_sysfs(sb);
4283 	if (err)
4284 		goto failed_mount7;
4285 
4286 #ifdef CONFIG_QUOTA
4287 	/* Enable quota usage during mount. */
4288 	if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4289 		err = ext4_enable_quotas(sb);
4290 		if (err)
4291 			goto failed_mount8;
4292 	}
4293 #endif  /* CONFIG_QUOTA */
4294 
4295 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4296 	ext4_orphan_cleanup(sb, es);
4297 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4298 	if (needs_recovery) {
4299 		ext4_msg(sb, KERN_INFO, "recovery complete");
4300 		ext4_mark_recovery_complete(sb, es);
4301 	}
4302 	if (EXT4_SB(sb)->s_journal) {
4303 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4304 			descr = " journalled data mode";
4305 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4306 			descr = " ordered data mode";
4307 		else
4308 			descr = " writeback data mode";
4309 	} else
4310 		descr = "out journal";
4311 
4312 	if (test_opt(sb, DISCARD)) {
4313 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4314 		if (!blk_queue_discard(q))
4315 			ext4_msg(sb, KERN_WARNING,
4316 				 "mounting with \"discard\" option, but "
4317 				 "the device does not support discard");
4318 	}
4319 
4320 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4321 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4322 			 "Opts: %.*s%s%s", descr,
4323 			 (int) sizeof(sbi->s_es->s_mount_opts),
4324 			 sbi->s_es->s_mount_opts,
4325 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4326 
4327 	if (es->s_error_count)
4328 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4329 
4330 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4331 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4332 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4333 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4334 
4335 	kfree(orig_data);
4336 	return 0;
4337 
4338 cantfind_ext4:
4339 	if (!silent)
4340 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4341 	goto failed_mount;
4342 
4343 #ifdef CONFIG_QUOTA
4344 failed_mount8:
4345 	ext4_unregister_sysfs(sb);
4346 #endif
4347 failed_mount7:
4348 	ext4_unregister_li_request(sb);
4349 failed_mount6:
4350 	ext4_mb_release(sb);
4351 	if (sbi->s_flex_groups)
4352 		kvfree(sbi->s_flex_groups);
4353 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4354 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4355 	percpu_counter_destroy(&sbi->s_dirs_counter);
4356 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4357 failed_mount5:
4358 	ext4_ext_release(sb);
4359 	ext4_release_system_zone(sb);
4360 failed_mount4a:
4361 	dput(sb->s_root);
4362 	sb->s_root = NULL;
4363 failed_mount4:
4364 	ext4_msg(sb, KERN_ERR, "mount failed");
4365 	if (EXT4_SB(sb)->rsv_conversion_wq)
4366 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4367 failed_mount_wq:
4368 	if (sbi->s_ea_inode_cache) {
4369 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4370 		sbi->s_ea_inode_cache = NULL;
4371 	}
4372 	if (sbi->s_ea_block_cache) {
4373 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4374 		sbi->s_ea_block_cache = NULL;
4375 	}
4376 	if (sbi->s_journal) {
4377 		jbd2_journal_destroy(sbi->s_journal);
4378 		sbi->s_journal = NULL;
4379 	}
4380 failed_mount3a:
4381 	ext4_es_unregister_shrinker(sbi);
4382 failed_mount3:
4383 	del_timer_sync(&sbi->s_err_report);
4384 	if (sbi->s_mmp_tsk)
4385 		kthread_stop(sbi->s_mmp_tsk);
4386 failed_mount2:
4387 	for (i = 0; i < db_count; i++)
4388 		brelse(sbi->s_group_desc[i]);
4389 	kvfree(sbi->s_group_desc);
4390 failed_mount:
4391 	if (sbi->s_chksum_driver)
4392 		crypto_free_shash(sbi->s_chksum_driver);
4393 #ifdef CONFIG_QUOTA
4394 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4395 		kfree(sbi->s_qf_names[i]);
4396 #endif
4397 	ext4_blkdev_remove(sbi);
4398 	brelse(bh);
4399 out_fail:
4400 	sb->s_fs_info = NULL;
4401 	kfree(sbi->s_blockgroup_lock);
4402 out_free_base:
4403 	kfree(sbi);
4404 	kfree(orig_data);
4405 	fs_put_dax(dax_dev);
4406 	return err ? err : ret;
4407 }
4408 
4409 /*
4410  * Setup any per-fs journal parameters now.  We'll do this both on
4411  * initial mount, once the journal has been initialised but before we've
4412  * done any recovery; and again on any subsequent remount.
4413  */
4414 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4415 {
4416 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4417 
4418 	journal->j_commit_interval = sbi->s_commit_interval;
4419 	journal->j_min_batch_time = sbi->s_min_batch_time;
4420 	journal->j_max_batch_time = sbi->s_max_batch_time;
4421 
4422 	write_lock(&journal->j_state_lock);
4423 	if (test_opt(sb, BARRIER))
4424 		journal->j_flags |= JBD2_BARRIER;
4425 	else
4426 		journal->j_flags &= ~JBD2_BARRIER;
4427 	if (test_opt(sb, DATA_ERR_ABORT))
4428 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4429 	else
4430 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4431 	write_unlock(&journal->j_state_lock);
4432 }
4433 
4434 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4435 					     unsigned int journal_inum)
4436 {
4437 	struct inode *journal_inode;
4438 
4439 	/*
4440 	 * Test for the existence of a valid inode on disk.  Bad things
4441 	 * happen if we iget() an unused inode, as the subsequent iput()
4442 	 * will try to delete it.
4443 	 */
4444 	journal_inode = ext4_iget(sb, journal_inum);
4445 	if (IS_ERR(journal_inode)) {
4446 		ext4_msg(sb, KERN_ERR, "no journal found");
4447 		return NULL;
4448 	}
4449 	if (!journal_inode->i_nlink) {
4450 		make_bad_inode(journal_inode);
4451 		iput(journal_inode);
4452 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4453 		return NULL;
4454 	}
4455 
4456 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4457 		  journal_inode, journal_inode->i_size);
4458 	if (!S_ISREG(journal_inode->i_mode)) {
4459 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4460 		iput(journal_inode);
4461 		return NULL;
4462 	}
4463 	return journal_inode;
4464 }
4465 
4466 static journal_t *ext4_get_journal(struct super_block *sb,
4467 				   unsigned int journal_inum)
4468 {
4469 	struct inode *journal_inode;
4470 	journal_t *journal;
4471 
4472 	BUG_ON(!ext4_has_feature_journal(sb));
4473 
4474 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4475 	if (!journal_inode)
4476 		return NULL;
4477 
4478 	journal = jbd2_journal_init_inode(journal_inode);
4479 	if (!journal) {
4480 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4481 		iput(journal_inode);
4482 		return NULL;
4483 	}
4484 	journal->j_private = sb;
4485 	ext4_init_journal_params(sb, journal);
4486 	return journal;
4487 }
4488 
4489 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4490 				       dev_t j_dev)
4491 {
4492 	struct buffer_head *bh;
4493 	journal_t *journal;
4494 	ext4_fsblk_t start;
4495 	ext4_fsblk_t len;
4496 	int hblock, blocksize;
4497 	ext4_fsblk_t sb_block;
4498 	unsigned long offset;
4499 	struct ext4_super_block *es;
4500 	struct block_device *bdev;
4501 
4502 	BUG_ON(!ext4_has_feature_journal(sb));
4503 
4504 	bdev = ext4_blkdev_get(j_dev, sb);
4505 	if (bdev == NULL)
4506 		return NULL;
4507 
4508 	blocksize = sb->s_blocksize;
4509 	hblock = bdev_logical_block_size(bdev);
4510 	if (blocksize < hblock) {
4511 		ext4_msg(sb, KERN_ERR,
4512 			"blocksize too small for journal device");
4513 		goto out_bdev;
4514 	}
4515 
4516 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4517 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4518 	set_blocksize(bdev, blocksize);
4519 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4520 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4521 		       "external journal");
4522 		goto out_bdev;
4523 	}
4524 
4525 	es = (struct ext4_super_block *) (bh->b_data + offset);
4526 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4527 	    !(le32_to_cpu(es->s_feature_incompat) &
4528 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4529 		ext4_msg(sb, KERN_ERR, "external journal has "
4530 					"bad superblock");
4531 		brelse(bh);
4532 		goto out_bdev;
4533 	}
4534 
4535 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4536 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4537 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4538 		ext4_msg(sb, KERN_ERR, "external journal has "
4539 				       "corrupt superblock");
4540 		brelse(bh);
4541 		goto out_bdev;
4542 	}
4543 
4544 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4545 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4546 		brelse(bh);
4547 		goto out_bdev;
4548 	}
4549 
4550 	len = ext4_blocks_count(es);
4551 	start = sb_block + 1;
4552 	brelse(bh);	/* we're done with the superblock */
4553 
4554 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4555 					start, len, blocksize);
4556 	if (!journal) {
4557 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4558 		goto out_bdev;
4559 	}
4560 	journal->j_private = sb;
4561 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4562 	wait_on_buffer(journal->j_sb_buffer);
4563 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4564 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4565 		goto out_journal;
4566 	}
4567 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4568 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4569 					"user (unsupported) - %d",
4570 			be32_to_cpu(journal->j_superblock->s_nr_users));
4571 		goto out_journal;
4572 	}
4573 	EXT4_SB(sb)->journal_bdev = bdev;
4574 	ext4_init_journal_params(sb, journal);
4575 	return journal;
4576 
4577 out_journal:
4578 	jbd2_journal_destroy(journal);
4579 out_bdev:
4580 	ext4_blkdev_put(bdev);
4581 	return NULL;
4582 }
4583 
4584 static int ext4_load_journal(struct super_block *sb,
4585 			     struct ext4_super_block *es,
4586 			     unsigned long journal_devnum)
4587 {
4588 	journal_t *journal;
4589 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4590 	dev_t journal_dev;
4591 	int err = 0;
4592 	int really_read_only;
4593 
4594 	BUG_ON(!ext4_has_feature_journal(sb));
4595 
4596 	if (journal_devnum &&
4597 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4598 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4599 			"numbers have changed");
4600 		journal_dev = new_decode_dev(journal_devnum);
4601 	} else
4602 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4603 
4604 	really_read_only = bdev_read_only(sb->s_bdev);
4605 
4606 	/*
4607 	 * Are we loading a blank journal or performing recovery after a
4608 	 * crash?  For recovery, we need to check in advance whether we
4609 	 * can get read-write access to the device.
4610 	 */
4611 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4612 		if (sb->s_flags & MS_RDONLY) {
4613 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4614 					"required on readonly filesystem");
4615 			if (really_read_only) {
4616 				ext4_msg(sb, KERN_ERR, "write access "
4617 					"unavailable, cannot proceed");
4618 				return -EROFS;
4619 			}
4620 			ext4_msg(sb, KERN_INFO, "write access will "
4621 			       "be enabled during recovery");
4622 		}
4623 	}
4624 
4625 	if (journal_inum && journal_dev) {
4626 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4627 		       "and inode journals!");
4628 		return -EINVAL;
4629 	}
4630 
4631 	if (journal_inum) {
4632 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4633 			return -EINVAL;
4634 	} else {
4635 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4636 			return -EINVAL;
4637 	}
4638 
4639 	if (!(journal->j_flags & JBD2_BARRIER))
4640 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4641 
4642 	if (!ext4_has_feature_journal_needs_recovery(sb))
4643 		err = jbd2_journal_wipe(journal, !really_read_only);
4644 	if (!err) {
4645 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4646 		if (save)
4647 			memcpy(save, ((char *) es) +
4648 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4649 		err = jbd2_journal_load(journal);
4650 		if (save)
4651 			memcpy(((char *) es) + EXT4_S_ERR_START,
4652 			       save, EXT4_S_ERR_LEN);
4653 		kfree(save);
4654 	}
4655 
4656 	if (err) {
4657 		ext4_msg(sb, KERN_ERR, "error loading journal");
4658 		jbd2_journal_destroy(journal);
4659 		return err;
4660 	}
4661 
4662 	EXT4_SB(sb)->s_journal = journal;
4663 	ext4_clear_journal_err(sb, es);
4664 
4665 	if (!really_read_only && journal_devnum &&
4666 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4667 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4668 
4669 		/* Make sure we flush the recovery flag to disk. */
4670 		ext4_commit_super(sb, 1);
4671 	}
4672 
4673 	return 0;
4674 }
4675 
4676 static int ext4_commit_super(struct super_block *sb, int sync)
4677 {
4678 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4679 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4680 	int error = 0;
4681 
4682 	if (!sbh || block_device_ejected(sb))
4683 		return error;
4684 	/*
4685 	 * If the file system is mounted read-only, don't update the
4686 	 * superblock write time.  This avoids updating the superblock
4687 	 * write time when we are mounting the root file system
4688 	 * read/only but we need to replay the journal; at that point,
4689 	 * for people who are east of GMT and who make their clock
4690 	 * tick in localtime for Windows bug-for-bug compatibility,
4691 	 * the clock is set in the future, and this will cause e2fsck
4692 	 * to complain and force a full file system check.
4693 	 */
4694 	if (!(sb->s_flags & MS_RDONLY))
4695 		es->s_wtime = cpu_to_le32(get_seconds());
4696 	if (sb->s_bdev->bd_part)
4697 		es->s_kbytes_written =
4698 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4699 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4700 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4701 	else
4702 		es->s_kbytes_written =
4703 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4704 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4705 		ext4_free_blocks_count_set(es,
4706 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4707 				&EXT4_SB(sb)->s_freeclusters_counter)));
4708 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4709 		es->s_free_inodes_count =
4710 			cpu_to_le32(percpu_counter_sum_positive(
4711 				&EXT4_SB(sb)->s_freeinodes_counter));
4712 	BUFFER_TRACE(sbh, "marking dirty");
4713 	ext4_superblock_csum_set(sb);
4714 	if (sync)
4715 		lock_buffer(sbh);
4716 	if (buffer_write_io_error(sbh)) {
4717 		/*
4718 		 * Oh, dear.  A previous attempt to write the
4719 		 * superblock failed.  This could happen because the
4720 		 * USB device was yanked out.  Or it could happen to
4721 		 * be a transient write error and maybe the block will
4722 		 * be remapped.  Nothing we can do but to retry the
4723 		 * write and hope for the best.
4724 		 */
4725 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4726 		       "superblock detected");
4727 		clear_buffer_write_io_error(sbh);
4728 		set_buffer_uptodate(sbh);
4729 	}
4730 	mark_buffer_dirty(sbh);
4731 	if (sync) {
4732 		unlock_buffer(sbh);
4733 		error = __sync_dirty_buffer(sbh,
4734 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4735 		if (error)
4736 			return error;
4737 
4738 		error = buffer_write_io_error(sbh);
4739 		if (error) {
4740 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4741 			       "superblock");
4742 			clear_buffer_write_io_error(sbh);
4743 			set_buffer_uptodate(sbh);
4744 		}
4745 	}
4746 	return error;
4747 }
4748 
4749 /*
4750  * Have we just finished recovery?  If so, and if we are mounting (or
4751  * remounting) the filesystem readonly, then we will end up with a
4752  * consistent fs on disk.  Record that fact.
4753  */
4754 static void ext4_mark_recovery_complete(struct super_block *sb,
4755 					struct ext4_super_block *es)
4756 {
4757 	journal_t *journal = EXT4_SB(sb)->s_journal;
4758 
4759 	if (!ext4_has_feature_journal(sb)) {
4760 		BUG_ON(journal != NULL);
4761 		return;
4762 	}
4763 	jbd2_journal_lock_updates(journal);
4764 	if (jbd2_journal_flush(journal) < 0)
4765 		goto out;
4766 
4767 	if (ext4_has_feature_journal_needs_recovery(sb) &&
4768 	    sb->s_flags & MS_RDONLY) {
4769 		ext4_clear_feature_journal_needs_recovery(sb);
4770 		ext4_commit_super(sb, 1);
4771 	}
4772 
4773 out:
4774 	jbd2_journal_unlock_updates(journal);
4775 }
4776 
4777 /*
4778  * If we are mounting (or read-write remounting) a filesystem whose journal
4779  * has recorded an error from a previous lifetime, move that error to the
4780  * main filesystem now.
4781  */
4782 static void ext4_clear_journal_err(struct super_block *sb,
4783 				   struct ext4_super_block *es)
4784 {
4785 	journal_t *journal;
4786 	int j_errno;
4787 	const char *errstr;
4788 
4789 	BUG_ON(!ext4_has_feature_journal(sb));
4790 
4791 	journal = EXT4_SB(sb)->s_journal;
4792 
4793 	/*
4794 	 * Now check for any error status which may have been recorded in the
4795 	 * journal by a prior ext4_error() or ext4_abort()
4796 	 */
4797 
4798 	j_errno = jbd2_journal_errno(journal);
4799 	if (j_errno) {
4800 		char nbuf[16];
4801 
4802 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4803 		ext4_warning(sb, "Filesystem error recorded "
4804 			     "from previous mount: %s", errstr);
4805 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4806 
4807 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4808 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4809 		ext4_commit_super(sb, 1);
4810 
4811 		jbd2_journal_clear_err(journal);
4812 		jbd2_journal_update_sb_errno(journal);
4813 	}
4814 }
4815 
4816 /*
4817  * Force the running and committing transactions to commit,
4818  * and wait on the commit.
4819  */
4820 int ext4_force_commit(struct super_block *sb)
4821 {
4822 	journal_t *journal;
4823 
4824 	if (sb->s_flags & MS_RDONLY)
4825 		return 0;
4826 
4827 	journal = EXT4_SB(sb)->s_journal;
4828 	return ext4_journal_force_commit(journal);
4829 }
4830 
4831 static int ext4_sync_fs(struct super_block *sb, int wait)
4832 {
4833 	int ret = 0;
4834 	tid_t target;
4835 	bool needs_barrier = false;
4836 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4837 
4838 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
4839 		return 0;
4840 
4841 	trace_ext4_sync_fs(sb, wait);
4842 	flush_workqueue(sbi->rsv_conversion_wq);
4843 	/*
4844 	 * Writeback quota in non-journalled quota case - journalled quota has
4845 	 * no dirty dquots
4846 	 */
4847 	dquot_writeback_dquots(sb, -1);
4848 	/*
4849 	 * Data writeback is possible w/o journal transaction, so barrier must
4850 	 * being sent at the end of the function. But we can skip it if
4851 	 * transaction_commit will do it for us.
4852 	 */
4853 	if (sbi->s_journal) {
4854 		target = jbd2_get_latest_transaction(sbi->s_journal);
4855 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4856 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4857 			needs_barrier = true;
4858 
4859 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4860 			if (wait)
4861 				ret = jbd2_log_wait_commit(sbi->s_journal,
4862 							   target);
4863 		}
4864 	} else if (wait && test_opt(sb, BARRIER))
4865 		needs_barrier = true;
4866 	if (needs_barrier) {
4867 		int err;
4868 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4869 		if (!ret)
4870 			ret = err;
4871 	}
4872 
4873 	return ret;
4874 }
4875 
4876 /*
4877  * LVM calls this function before a (read-only) snapshot is created.  This
4878  * gives us a chance to flush the journal completely and mark the fs clean.
4879  *
4880  * Note that only this function cannot bring a filesystem to be in a clean
4881  * state independently. It relies on upper layer to stop all data & metadata
4882  * modifications.
4883  */
4884 static int ext4_freeze(struct super_block *sb)
4885 {
4886 	int error = 0;
4887 	journal_t *journal;
4888 
4889 	if (sb->s_flags & MS_RDONLY)
4890 		return 0;
4891 
4892 	journal = EXT4_SB(sb)->s_journal;
4893 
4894 	if (journal) {
4895 		/* Now we set up the journal barrier. */
4896 		jbd2_journal_lock_updates(journal);
4897 
4898 		/*
4899 		 * Don't clear the needs_recovery flag if we failed to
4900 		 * flush the journal.
4901 		 */
4902 		error = jbd2_journal_flush(journal);
4903 		if (error < 0)
4904 			goto out;
4905 
4906 		/* Journal blocked and flushed, clear needs_recovery flag. */
4907 		ext4_clear_feature_journal_needs_recovery(sb);
4908 	}
4909 
4910 	error = ext4_commit_super(sb, 1);
4911 out:
4912 	if (journal)
4913 		/* we rely on upper layer to stop further updates */
4914 		jbd2_journal_unlock_updates(journal);
4915 	return error;
4916 }
4917 
4918 /*
4919  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4920  * flag here, even though the filesystem is not technically dirty yet.
4921  */
4922 static int ext4_unfreeze(struct super_block *sb)
4923 {
4924 	if ((sb->s_flags & MS_RDONLY) || ext4_forced_shutdown(EXT4_SB(sb)))
4925 		return 0;
4926 
4927 	if (EXT4_SB(sb)->s_journal) {
4928 		/* Reset the needs_recovery flag before the fs is unlocked. */
4929 		ext4_set_feature_journal_needs_recovery(sb);
4930 	}
4931 
4932 	ext4_commit_super(sb, 1);
4933 	return 0;
4934 }
4935 
4936 /*
4937  * Structure to save mount options for ext4_remount's benefit
4938  */
4939 struct ext4_mount_options {
4940 	unsigned long s_mount_opt;
4941 	unsigned long s_mount_opt2;
4942 	kuid_t s_resuid;
4943 	kgid_t s_resgid;
4944 	unsigned long s_commit_interval;
4945 	u32 s_min_batch_time, s_max_batch_time;
4946 #ifdef CONFIG_QUOTA
4947 	int s_jquota_fmt;
4948 	char *s_qf_names[EXT4_MAXQUOTAS];
4949 #endif
4950 };
4951 
4952 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4953 {
4954 	struct ext4_super_block *es;
4955 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4956 	unsigned long old_sb_flags;
4957 	struct ext4_mount_options old_opts;
4958 	int enable_quota = 0;
4959 	ext4_group_t g;
4960 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4961 	int err = 0;
4962 #ifdef CONFIG_QUOTA
4963 	int i, j;
4964 #endif
4965 	char *orig_data = kstrdup(data, GFP_KERNEL);
4966 
4967 	/* Store the original options */
4968 	old_sb_flags = sb->s_flags;
4969 	old_opts.s_mount_opt = sbi->s_mount_opt;
4970 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4971 	old_opts.s_resuid = sbi->s_resuid;
4972 	old_opts.s_resgid = sbi->s_resgid;
4973 	old_opts.s_commit_interval = sbi->s_commit_interval;
4974 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4975 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4976 #ifdef CONFIG_QUOTA
4977 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4978 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4979 		if (sbi->s_qf_names[i]) {
4980 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4981 							 GFP_KERNEL);
4982 			if (!old_opts.s_qf_names[i]) {
4983 				for (j = 0; j < i; j++)
4984 					kfree(old_opts.s_qf_names[j]);
4985 				kfree(orig_data);
4986 				return -ENOMEM;
4987 			}
4988 		} else
4989 			old_opts.s_qf_names[i] = NULL;
4990 #endif
4991 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4992 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4993 
4994 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4995 		err = -EINVAL;
4996 		goto restore_opts;
4997 	}
4998 
4999 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5000 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5001 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5002 			 "during remount not supported; ignoring");
5003 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5004 	}
5005 
5006 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5007 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5008 			ext4_msg(sb, KERN_ERR, "can't mount with "
5009 				 "both data=journal and delalloc");
5010 			err = -EINVAL;
5011 			goto restore_opts;
5012 		}
5013 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5014 			ext4_msg(sb, KERN_ERR, "can't mount with "
5015 				 "both data=journal and dioread_nolock");
5016 			err = -EINVAL;
5017 			goto restore_opts;
5018 		}
5019 		if (test_opt(sb, DAX)) {
5020 			ext4_msg(sb, KERN_ERR, "can't mount with "
5021 				 "both data=journal and dax");
5022 			err = -EINVAL;
5023 			goto restore_opts;
5024 		}
5025 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5026 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5027 			ext4_msg(sb, KERN_ERR, "can't mount with "
5028 				"journal_async_commit in data=ordered mode");
5029 			err = -EINVAL;
5030 			goto restore_opts;
5031 		}
5032 	}
5033 
5034 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5035 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5036 		err = -EINVAL;
5037 		goto restore_opts;
5038 	}
5039 
5040 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5041 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5042 			"dax flag with busy inodes while remounting");
5043 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5044 	}
5045 
5046 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5047 		ext4_abort(sb, "Abort forced by user");
5048 
5049 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
5050 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
5051 
5052 	es = sbi->s_es;
5053 
5054 	if (sbi->s_journal) {
5055 		ext4_init_journal_params(sb, sbi->s_journal);
5056 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5057 	}
5058 
5059 	if (*flags & MS_LAZYTIME)
5060 		sb->s_flags |= MS_LAZYTIME;
5061 
5062 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
5063 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5064 			err = -EROFS;
5065 			goto restore_opts;
5066 		}
5067 
5068 		if (*flags & MS_RDONLY) {
5069 			err = sync_filesystem(sb);
5070 			if (err < 0)
5071 				goto restore_opts;
5072 			err = dquot_suspend(sb, -1);
5073 			if (err < 0)
5074 				goto restore_opts;
5075 
5076 			/*
5077 			 * First of all, the unconditional stuff we have to do
5078 			 * to disable replay of the journal when we next remount
5079 			 */
5080 			sb->s_flags |= MS_RDONLY;
5081 
5082 			/*
5083 			 * OK, test if we are remounting a valid rw partition
5084 			 * readonly, and if so set the rdonly flag and then
5085 			 * mark the partition as valid again.
5086 			 */
5087 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5088 			    (sbi->s_mount_state & EXT4_VALID_FS))
5089 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5090 
5091 			if (sbi->s_journal)
5092 				ext4_mark_recovery_complete(sb, es);
5093 		} else {
5094 			/* Make sure we can mount this feature set readwrite */
5095 			if (ext4_has_feature_readonly(sb) ||
5096 			    !ext4_feature_set_ok(sb, 0)) {
5097 				err = -EROFS;
5098 				goto restore_opts;
5099 			}
5100 			/*
5101 			 * Make sure the group descriptor checksums
5102 			 * are sane.  If they aren't, refuse to remount r/w.
5103 			 */
5104 			for (g = 0; g < sbi->s_groups_count; g++) {
5105 				struct ext4_group_desc *gdp =
5106 					ext4_get_group_desc(sb, g, NULL);
5107 
5108 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5109 					ext4_msg(sb, KERN_ERR,
5110 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5111 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5112 					       le16_to_cpu(gdp->bg_checksum));
5113 					err = -EFSBADCRC;
5114 					goto restore_opts;
5115 				}
5116 			}
5117 
5118 			/*
5119 			 * If we have an unprocessed orphan list hanging
5120 			 * around from a previously readonly bdev mount,
5121 			 * require a full umount/remount for now.
5122 			 */
5123 			if (es->s_last_orphan) {
5124 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5125 				       "remount RDWR because of unprocessed "
5126 				       "orphan inode list.  Please "
5127 				       "umount/remount instead");
5128 				err = -EINVAL;
5129 				goto restore_opts;
5130 			}
5131 
5132 			/*
5133 			 * Mounting a RDONLY partition read-write, so reread
5134 			 * and store the current valid flag.  (It may have
5135 			 * been changed by e2fsck since we originally mounted
5136 			 * the partition.)
5137 			 */
5138 			if (sbi->s_journal)
5139 				ext4_clear_journal_err(sb, es);
5140 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5141 			if (!ext4_setup_super(sb, es, 0))
5142 				sb->s_flags &= ~MS_RDONLY;
5143 			if (ext4_has_feature_mmp(sb))
5144 				if (ext4_multi_mount_protect(sb,
5145 						le64_to_cpu(es->s_mmp_block))) {
5146 					err = -EROFS;
5147 					goto restore_opts;
5148 				}
5149 			enable_quota = 1;
5150 		}
5151 	}
5152 
5153 	/*
5154 	 * Reinitialize lazy itable initialization thread based on
5155 	 * current settings
5156 	 */
5157 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5158 		ext4_unregister_li_request(sb);
5159 	else {
5160 		ext4_group_t first_not_zeroed;
5161 		first_not_zeroed = ext4_has_uninit_itable(sb);
5162 		ext4_register_li_request(sb, first_not_zeroed);
5163 	}
5164 
5165 	ext4_setup_system_zone(sb);
5166 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5167 		ext4_commit_super(sb, 1);
5168 
5169 #ifdef CONFIG_QUOTA
5170 	/* Release old quota file names */
5171 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5172 		kfree(old_opts.s_qf_names[i]);
5173 	if (enable_quota) {
5174 		if (sb_any_quota_suspended(sb))
5175 			dquot_resume(sb, -1);
5176 		else if (ext4_has_feature_quota(sb)) {
5177 			err = ext4_enable_quotas(sb);
5178 			if (err)
5179 				goto restore_opts;
5180 		}
5181 	}
5182 #endif
5183 
5184 	*flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5185 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5186 	kfree(orig_data);
5187 	return 0;
5188 
5189 restore_opts:
5190 	sb->s_flags = old_sb_flags;
5191 	sbi->s_mount_opt = old_opts.s_mount_opt;
5192 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5193 	sbi->s_resuid = old_opts.s_resuid;
5194 	sbi->s_resgid = old_opts.s_resgid;
5195 	sbi->s_commit_interval = old_opts.s_commit_interval;
5196 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5197 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5198 #ifdef CONFIG_QUOTA
5199 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5200 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5201 		kfree(sbi->s_qf_names[i]);
5202 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5203 	}
5204 #endif
5205 	kfree(orig_data);
5206 	return err;
5207 }
5208 
5209 #ifdef CONFIG_QUOTA
5210 static int ext4_statfs_project(struct super_block *sb,
5211 			       kprojid_t projid, struct kstatfs *buf)
5212 {
5213 	struct kqid qid;
5214 	struct dquot *dquot;
5215 	u64 limit;
5216 	u64 curblock;
5217 
5218 	qid = make_kqid_projid(projid);
5219 	dquot = dqget(sb, qid);
5220 	if (IS_ERR(dquot))
5221 		return PTR_ERR(dquot);
5222 	spin_lock(&dquot->dq_dqb_lock);
5223 
5224 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5225 		 dquot->dq_dqb.dqb_bsoftlimit :
5226 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5227 	if (limit && buf->f_blocks > limit) {
5228 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5229 		buf->f_blocks = limit;
5230 		buf->f_bfree = buf->f_bavail =
5231 			(buf->f_blocks > curblock) ?
5232 			 (buf->f_blocks - curblock) : 0;
5233 	}
5234 
5235 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5236 		dquot->dq_dqb.dqb_isoftlimit :
5237 		dquot->dq_dqb.dqb_ihardlimit;
5238 	if (limit && buf->f_files > limit) {
5239 		buf->f_files = limit;
5240 		buf->f_ffree =
5241 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5242 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5243 	}
5244 
5245 	spin_unlock(&dquot->dq_dqb_lock);
5246 	dqput(dquot);
5247 	return 0;
5248 }
5249 #endif
5250 
5251 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5252 {
5253 	struct super_block *sb = dentry->d_sb;
5254 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5255 	struct ext4_super_block *es = sbi->s_es;
5256 	ext4_fsblk_t overhead = 0, resv_blocks;
5257 	u64 fsid;
5258 	s64 bfree;
5259 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5260 
5261 	if (!test_opt(sb, MINIX_DF))
5262 		overhead = sbi->s_overhead;
5263 
5264 	buf->f_type = EXT4_SUPER_MAGIC;
5265 	buf->f_bsize = sb->s_blocksize;
5266 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5267 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5268 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5269 	/* prevent underflow in case that few free space is available */
5270 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5271 	buf->f_bavail = buf->f_bfree -
5272 			(ext4_r_blocks_count(es) + resv_blocks);
5273 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5274 		buf->f_bavail = 0;
5275 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5276 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5277 	buf->f_namelen = EXT4_NAME_LEN;
5278 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5279 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5280 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5281 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5282 
5283 #ifdef CONFIG_QUOTA
5284 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5285 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5286 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5287 #endif
5288 	return 0;
5289 }
5290 
5291 
5292 #ifdef CONFIG_QUOTA
5293 
5294 /*
5295  * Helper functions so that transaction is started before we acquire dqio_sem
5296  * to keep correct lock ordering of transaction > dqio_sem
5297  */
5298 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5299 {
5300 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5301 }
5302 
5303 static int ext4_write_dquot(struct dquot *dquot)
5304 {
5305 	int ret, err;
5306 	handle_t *handle;
5307 	struct inode *inode;
5308 
5309 	inode = dquot_to_inode(dquot);
5310 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5311 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5312 	if (IS_ERR(handle))
5313 		return PTR_ERR(handle);
5314 	ret = dquot_commit(dquot);
5315 	err = ext4_journal_stop(handle);
5316 	if (!ret)
5317 		ret = err;
5318 	return ret;
5319 }
5320 
5321 static int ext4_acquire_dquot(struct dquot *dquot)
5322 {
5323 	int ret, err;
5324 	handle_t *handle;
5325 
5326 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5327 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5328 	if (IS_ERR(handle))
5329 		return PTR_ERR(handle);
5330 	ret = dquot_acquire(dquot);
5331 	err = ext4_journal_stop(handle);
5332 	if (!ret)
5333 		ret = err;
5334 	return ret;
5335 }
5336 
5337 static int ext4_release_dquot(struct dquot *dquot)
5338 {
5339 	int ret, err;
5340 	handle_t *handle;
5341 
5342 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5343 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5344 	if (IS_ERR(handle)) {
5345 		/* Release dquot anyway to avoid endless cycle in dqput() */
5346 		dquot_release(dquot);
5347 		return PTR_ERR(handle);
5348 	}
5349 	ret = dquot_release(dquot);
5350 	err = ext4_journal_stop(handle);
5351 	if (!ret)
5352 		ret = err;
5353 	return ret;
5354 }
5355 
5356 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5357 {
5358 	struct super_block *sb = dquot->dq_sb;
5359 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5360 
5361 	/* Are we journaling quotas? */
5362 	if (ext4_has_feature_quota(sb) ||
5363 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5364 		dquot_mark_dquot_dirty(dquot);
5365 		return ext4_write_dquot(dquot);
5366 	} else {
5367 		return dquot_mark_dquot_dirty(dquot);
5368 	}
5369 }
5370 
5371 static int ext4_write_info(struct super_block *sb, int type)
5372 {
5373 	int ret, err;
5374 	handle_t *handle;
5375 
5376 	/* Data block + inode block */
5377 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5378 	if (IS_ERR(handle))
5379 		return PTR_ERR(handle);
5380 	ret = dquot_commit_info(sb, type);
5381 	err = ext4_journal_stop(handle);
5382 	if (!ret)
5383 		ret = err;
5384 	return ret;
5385 }
5386 
5387 /*
5388  * Turn on quotas during mount time - we need to find
5389  * the quota file and such...
5390  */
5391 static int ext4_quota_on_mount(struct super_block *sb, int type)
5392 {
5393 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5394 					EXT4_SB(sb)->s_jquota_fmt, type);
5395 }
5396 
5397 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5398 {
5399 	struct ext4_inode_info *ei = EXT4_I(inode);
5400 
5401 	/* The first argument of lockdep_set_subclass has to be
5402 	 * *exactly* the same as the argument to init_rwsem() --- in
5403 	 * this case, in init_once() --- or lockdep gets unhappy
5404 	 * because the name of the lock is set using the
5405 	 * stringification of the argument to init_rwsem().
5406 	 */
5407 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5408 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5409 }
5410 
5411 /*
5412  * Standard function to be called on quota_on
5413  */
5414 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5415 			 const struct path *path)
5416 {
5417 	int err;
5418 
5419 	if (!test_opt(sb, QUOTA))
5420 		return -EINVAL;
5421 
5422 	/* Quotafile not on the same filesystem? */
5423 	if (path->dentry->d_sb != sb)
5424 		return -EXDEV;
5425 	/* Journaling quota? */
5426 	if (EXT4_SB(sb)->s_qf_names[type]) {
5427 		/* Quotafile not in fs root? */
5428 		if (path->dentry->d_parent != sb->s_root)
5429 			ext4_msg(sb, KERN_WARNING,
5430 				"Quota file not on filesystem root. "
5431 				"Journaled quota will not work");
5432 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5433 	} else {
5434 		/*
5435 		 * Clear the flag just in case mount options changed since
5436 		 * last time.
5437 		 */
5438 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5439 	}
5440 
5441 	/*
5442 	 * When we journal data on quota file, we have to flush journal to see
5443 	 * all updates to the file when we bypass pagecache...
5444 	 */
5445 	if (EXT4_SB(sb)->s_journal &&
5446 	    ext4_should_journal_data(d_inode(path->dentry))) {
5447 		/*
5448 		 * We don't need to lock updates but journal_flush() could
5449 		 * otherwise be livelocked...
5450 		 */
5451 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5452 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5453 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5454 		if (err)
5455 			return err;
5456 	}
5457 
5458 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5459 	err = dquot_quota_on(sb, type, format_id, path);
5460 	if (err) {
5461 		lockdep_set_quota_inode(path->dentry->d_inode,
5462 					     I_DATA_SEM_NORMAL);
5463 	} else {
5464 		struct inode *inode = d_inode(path->dentry);
5465 		handle_t *handle;
5466 
5467 		/*
5468 		 * Set inode flags to prevent userspace from messing with quota
5469 		 * files. If this fails, we return success anyway since quotas
5470 		 * are already enabled and this is not a hard failure.
5471 		 */
5472 		inode_lock(inode);
5473 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5474 		if (IS_ERR(handle))
5475 			goto unlock_inode;
5476 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5477 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5478 				S_NOATIME | S_IMMUTABLE);
5479 		ext4_mark_inode_dirty(handle, inode);
5480 		ext4_journal_stop(handle);
5481 	unlock_inode:
5482 		inode_unlock(inode);
5483 	}
5484 	return err;
5485 }
5486 
5487 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5488 			     unsigned int flags)
5489 {
5490 	int err;
5491 	struct inode *qf_inode;
5492 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5493 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5494 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5495 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5496 	};
5497 
5498 	BUG_ON(!ext4_has_feature_quota(sb));
5499 
5500 	if (!qf_inums[type])
5501 		return -EPERM;
5502 
5503 	qf_inode = ext4_iget(sb, qf_inums[type]);
5504 	if (IS_ERR(qf_inode)) {
5505 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5506 		return PTR_ERR(qf_inode);
5507 	}
5508 
5509 	/* Don't account quota for quota files to avoid recursion */
5510 	qf_inode->i_flags |= S_NOQUOTA;
5511 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5512 	err = dquot_enable(qf_inode, type, format_id, flags);
5513 	iput(qf_inode);
5514 	if (err)
5515 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5516 
5517 	return err;
5518 }
5519 
5520 /* Enable usage tracking for all quota types. */
5521 static int ext4_enable_quotas(struct super_block *sb)
5522 {
5523 	int type, err = 0;
5524 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5525 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5526 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5527 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5528 	};
5529 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5530 		test_opt(sb, USRQUOTA),
5531 		test_opt(sb, GRPQUOTA),
5532 		test_opt(sb, PRJQUOTA),
5533 	};
5534 
5535 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5536 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5537 		if (qf_inums[type]) {
5538 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5539 				DQUOT_USAGE_ENABLED |
5540 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5541 			if (err) {
5542 				for (type--; type >= 0; type--)
5543 					dquot_quota_off(sb, type);
5544 
5545 				ext4_warning(sb,
5546 					"Failed to enable quota tracking "
5547 					"(type=%d, err=%d). Please run "
5548 					"e2fsck to fix.", type, err);
5549 				return err;
5550 			}
5551 		}
5552 	}
5553 	return 0;
5554 }
5555 
5556 static int ext4_quota_off(struct super_block *sb, int type)
5557 {
5558 	struct inode *inode = sb_dqopt(sb)->files[type];
5559 	handle_t *handle;
5560 	int err;
5561 
5562 	/* Force all delayed allocation blocks to be allocated.
5563 	 * Caller already holds s_umount sem */
5564 	if (test_opt(sb, DELALLOC))
5565 		sync_filesystem(sb);
5566 
5567 	if (!inode || !igrab(inode))
5568 		goto out;
5569 
5570 	err = dquot_quota_off(sb, type);
5571 	if (err || ext4_has_feature_quota(sb))
5572 		goto out_put;
5573 
5574 	inode_lock(inode);
5575 	/*
5576 	 * Update modification times of quota files when userspace can
5577 	 * start looking at them. If we fail, we return success anyway since
5578 	 * this is not a hard failure and quotas are already disabled.
5579 	 */
5580 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5581 	if (IS_ERR(handle))
5582 		goto out_unlock;
5583 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5584 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5585 	inode->i_mtime = inode->i_ctime = current_time(inode);
5586 	ext4_mark_inode_dirty(handle, inode);
5587 	ext4_journal_stop(handle);
5588 out_unlock:
5589 	inode_unlock(inode);
5590 out_put:
5591 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5592 	iput(inode);
5593 	return err;
5594 out:
5595 	return dquot_quota_off(sb, type);
5596 }
5597 
5598 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5599  * acquiring the locks... As quota files are never truncated and quota code
5600  * itself serializes the operations (and no one else should touch the files)
5601  * we don't have to be afraid of races */
5602 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5603 			       size_t len, loff_t off)
5604 {
5605 	struct inode *inode = sb_dqopt(sb)->files[type];
5606 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5607 	int offset = off & (sb->s_blocksize - 1);
5608 	int tocopy;
5609 	size_t toread;
5610 	struct buffer_head *bh;
5611 	loff_t i_size = i_size_read(inode);
5612 
5613 	if (off > i_size)
5614 		return 0;
5615 	if (off+len > i_size)
5616 		len = i_size-off;
5617 	toread = len;
5618 	while (toread > 0) {
5619 		tocopy = sb->s_blocksize - offset < toread ?
5620 				sb->s_blocksize - offset : toread;
5621 		bh = ext4_bread(NULL, inode, blk, 0);
5622 		if (IS_ERR(bh))
5623 			return PTR_ERR(bh);
5624 		if (!bh)	/* A hole? */
5625 			memset(data, 0, tocopy);
5626 		else
5627 			memcpy(data, bh->b_data+offset, tocopy);
5628 		brelse(bh);
5629 		offset = 0;
5630 		toread -= tocopy;
5631 		data += tocopy;
5632 		blk++;
5633 	}
5634 	return len;
5635 }
5636 
5637 /* Write to quotafile (we know the transaction is already started and has
5638  * enough credits) */
5639 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5640 				const char *data, size_t len, loff_t off)
5641 {
5642 	struct inode *inode = sb_dqopt(sb)->files[type];
5643 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5644 	int err, offset = off & (sb->s_blocksize - 1);
5645 	int retries = 0;
5646 	struct buffer_head *bh;
5647 	handle_t *handle = journal_current_handle();
5648 
5649 	if (EXT4_SB(sb)->s_journal && !handle) {
5650 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5651 			" cancelled because transaction is not started",
5652 			(unsigned long long)off, (unsigned long long)len);
5653 		return -EIO;
5654 	}
5655 	/*
5656 	 * Since we account only one data block in transaction credits,
5657 	 * then it is impossible to cross a block boundary.
5658 	 */
5659 	if (sb->s_blocksize - offset < len) {
5660 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5661 			" cancelled because not block aligned",
5662 			(unsigned long long)off, (unsigned long long)len);
5663 		return -EIO;
5664 	}
5665 
5666 	do {
5667 		bh = ext4_bread(handle, inode, blk,
5668 				EXT4_GET_BLOCKS_CREATE |
5669 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5670 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5671 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5672 	if (IS_ERR(bh))
5673 		return PTR_ERR(bh);
5674 	if (!bh)
5675 		goto out;
5676 	BUFFER_TRACE(bh, "get write access");
5677 	err = ext4_journal_get_write_access(handle, bh);
5678 	if (err) {
5679 		brelse(bh);
5680 		return err;
5681 	}
5682 	lock_buffer(bh);
5683 	memcpy(bh->b_data+offset, data, len);
5684 	flush_dcache_page(bh->b_page);
5685 	unlock_buffer(bh);
5686 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5687 	brelse(bh);
5688 out:
5689 	if (inode->i_size < off + len) {
5690 		i_size_write(inode, off + len);
5691 		EXT4_I(inode)->i_disksize = inode->i_size;
5692 		ext4_mark_inode_dirty(handle, inode);
5693 	}
5694 	return len;
5695 }
5696 
5697 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5698 {
5699 	const struct quota_format_ops	*ops;
5700 
5701 	if (!sb_has_quota_loaded(sb, qid->type))
5702 		return -ESRCH;
5703 	ops = sb_dqopt(sb)->ops[qid->type];
5704 	if (!ops || !ops->get_next_id)
5705 		return -ENOSYS;
5706 	return dquot_get_next_id(sb, qid);
5707 }
5708 #endif
5709 
5710 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5711 		       const char *dev_name, void *data)
5712 {
5713 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5714 }
5715 
5716 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5717 static inline void register_as_ext2(void)
5718 {
5719 	int err = register_filesystem(&ext2_fs_type);
5720 	if (err)
5721 		printk(KERN_WARNING
5722 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5723 }
5724 
5725 static inline void unregister_as_ext2(void)
5726 {
5727 	unregister_filesystem(&ext2_fs_type);
5728 }
5729 
5730 static inline int ext2_feature_set_ok(struct super_block *sb)
5731 {
5732 	if (ext4_has_unknown_ext2_incompat_features(sb))
5733 		return 0;
5734 	if (sb->s_flags & MS_RDONLY)
5735 		return 1;
5736 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5737 		return 0;
5738 	return 1;
5739 }
5740 #else
5741 static inline void register_as_ext2(void) { }
5742 static inline void unregister_as_ext2(void) { }
5743 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5744 #endif
5745 
5746 static inline void register_as_ext3(void)
5747 {
5748 	int err = register_filesystem(&ext3_fs_type);
5749 	if (err)
5750 		printk(KERN_WARNING
5751 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5752 }
5753 
5754 static inline void unregister_as_ext3(void)
5755 {
5756 	unregister_filesystem(&ext3_fs_type);
5757 }
5758 
5759 static inline int ext3_feature_set_ok(struct super_block *sb)
5760 {
5761 	if (ext4_has_unknown_ext3_incompat_features(sb))
5762 		return 0;
5763 	if (!ext4_has_feature_journal(sb))
5764 		return 0;
5765 	if (sb->s_flags & MS_RDONLY)
5766 		return 1;
5767 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5768 		return 0;
5769 	return 1;
5770 }
5771 
5772 static struct file_system_type ext4_fs_type = {
5773 	.owner		= THIS_MODULE,
5774 	.name		= "ext4",
5775 	.mount		= ext4_mount,
5776 	.kill_sb	= kill_block_super,
5777 	.fs_flags	= FS_REQUIRES_DEV,
5778 };
5779 MODULE_ALIAS_FS("ext4");
5780 
5781 /* Shared across all ext4 file systems */
5782 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5783 
5784 static int __init ext4_init_fs(void)
5785 {
5786 	int i, err;
5787 
5788 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5789 	ext4_li_info = NULL;
5790 	mutex_init(&ext4_li_mtx);
5791 
5792 	/* Build-time check for flags consistency */
5793 	ext4_check_flag_values();
5794 
5795 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5796 		init_waitqueue_head(&ext4__ioend_wq[i]);
5797 
5798 	err = ext4_init_es();
5799 	if (err)
5800 		return err;
5801 
5802 	err = ext4_init_pageio();
5803 	if (err)
5804 		goto out5;
5805 
5806 	err = ext4_init_system_zone();
5807 	if (err)
5808 		goto out4;
5809 
5810 	err = ext4_init_sysfs();
5811 	if (err)
5812 		goto out3;
5813 
5814 	err = ext4_init_mballoc();
5815 	if (err)
5816 		goto out2;
5817 	err = init_inodecache();
5818 	if (err)
5819 		goto out1;
5820 	register_as_ext3();
5821 	register_as_ext2();
5822 	err = register_filesystem(&ext4_fs_type);
5823 	if (err)
5824 		goto out;
5825 
5826 	return 0;
5827 out:
5828 	unregister_as_ext2();
5829 	unregister_as_ext3();
5830 	destroy_inodecache();
5831 out1:
5832 	ext4_exit_mballoc();
5833 out2:
5834 	ext4_exit_sysfs();
5835 out3:
5836 	ext4_exit_system_zone();
5837 out4:
5838 	ext4_exit_pageio();
5839 out5:
5840 	ext4_exit_es();
5841 
5842 	return err;
5843 }
5844 
5845 static void __exit ext4_exit_fs(void)
5846 {
5847 	ext4_destroy_lazyinit_thread();
5848 	unregister_as_ext2();
5849 	unregister_as_ext3();
5850 	unregister_filesystem(&ext4_fs_type);
5851 	destroy_inodecache();
5852 	ext4_exit_mballoc();
5853 	ext4_exit_sysfs();
5854 	ext4_exit_system_zone();
5855 	ext4_exit_pageio();
5856 	ext4_exit_es();
5857 }
5858 
5859 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5860 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5861 MODULE_LICENSE("GPL");
5862 module_init(ext4_init_fs)
5863 module_exit(ext4_exit_fs)
5864