xref: /linux/fs/ext4/super.c (revision 507e190946297c34a27d9366b0661d5e506fdd03)
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 	kfree(sbi);
955 }
956 
957 static struct kmem_cache *ext4_inode_cachep;
958 
959 /*
960  * Called inside transaction, so use GFP_NOFS
961  */
962 static struct inode *ext4_alloc_inode(struct super_block *sb)
963 {
964 	struct ext4_inode_info *ei;
965 
966 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
967 	if (!ei)
968 		return NULL;
969 
970 	ei->vfs_inode.i_version = 1;
971 	spin_lock_init(&ei->i_raw_lock);
972 	INIT_LIST_HEAD(&ei->i_prealloc_list);
973 	spin_lock_init(&ei->i_prealloc_lock);
974 	ext4_es_init_tree(&ei->i_es_tree);
975 	rwlock_init(&ei->i_es_lock);
976 	INIT_LIST_HEAD(&ei->i_es_list);
977 	ei->i_es_all_nr = 0;
978 	ei->i_es_shk_nr = 0;
979 	ei->i_es_shrink_lblk = 0;
980 	ei->i_reserved_data_blocks = 0;
981 	ei->i_da_metadata_calc_len = 0;
982 	ei->i_da_metadata_calc_last_lblock = 0;
983 	spin_lock_init(&(ei->i_block_reservation_lock));
984 #ifdef CONFIG_QUOTA
985 	ei->i_reserved_quota = 0;
986 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
987 #endif
988 	ei->jinode = NULL;
989 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
990 	spin_lock_init(&ei->i_completed_io_lock);
991 	ei->i_sync_tid = 0;
992 	ei->i_datasync_tid = 0;
993 	atomic_set(&ei->i_unwritten, 0);
994 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
995 	return &ei->vfs_inode;
996 }
997 
998 static int ext4_drop_inode(struct inode *inode)
999 {
1000 	int drop = generic_drop_inode(inode);
1001 
1002 	trace_ext4_drop_inode(inode, drop);
1003 	return drop;
1004 }
1005 
1006 static void ext4_i_callback(struct rcu_head *head)
1007 {
1008 	struct inode *inode = container_of(head, struct inode, i_rcu);
1009 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1010 }
1011 
1012 static void ext4_destroy_inode(struct inode *inode)
1013 {
1014 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1015 		ext4_msg(inode->i_sb, KERN_ERR,
1016 			 "Inode %lu (%p): orphan list check failed!",
1017 			 inode->i_ino, EXT4_I(inode));
1018 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1019 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1020 				true);
1021 		dump_stack();
1022 	}
1023 	call_rcu(&inode->i_rcu, ext4_i_callback);
1024 }
1025 
1026 static void init_once(void *foo)
1027 {
1028 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1029 
1030 	INIT_LIST_HEAD(&ei->i_orphan);
1031 	init_rwsem(&ei->xattr_sem);
1032 	init_rwsem(&ei->i_data_sem);
1033 	init_rwsem(&ei->i_mmap_sem);
1034 	inode_init_once(&ei->vfs_inode);
1035 }
1036 
1037 static int __init init_inodecache(void)
1038 {
1039 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1040 					     sizeof(struct ext4_inode_info),
1041 					     0, (SLAB_RECLAIM_ACCOUNT|
1042 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1043 					     init_once);
1044 	if (ext4_inode_cachep == NULL)
1045 		return -ENOMEM;
1046 	return 0;
1047 }
1048 
1049 static void destroy_inodecache(void)
1050 {
1051 	/*
1052 	 * Make sure all delayed rcu free inodes are flushed before we
1053 	 * destroy cache.
1054 	 */
1055 	rcu_barrier();
1056 	kmem_cache_destroy(ext4_inode_cachep);
1057 }
1058 
1059 void ext4_clear_inode(struct inode *inode)
1060 {
1061 	invalidate_inode_buffers(inode);
1062 	clear_inode(inode);
1063 	dquot_drop(inode);
1064 	ext4_discard_preallocations(inode);
1065 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1066 	if (EXT4_I(inode)->jinode) {
1067 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1068 					       EXT4_I(inode)->jinode);
1069 		jbd2_free_inode(EXT4_I(inode)->jinode);
1070 		EXT4_I(inode)->jinode = NULL;
1071 	}
1072 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1073 	fscrypt_put_encryption_info(inode, NULL);
1074 #endif
1075 }
1076 
1077 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1078 					u64 ino, u32 generation)
1079 {
1080 	struct inode *inode;
1081 
1082 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1083 		return ERR_PTR(-ESTALE);
1084 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1085 		return ERR_PTR(-ESTALE);
1086 
1087 	/* iget isn't really right if the inode is currently unallocated!!
1088 	 *
1089 	 * ext4_read_inode will return a bad_inode if the inode had been
1090 	 * deleted, so we should be safe.
1091 	 *
1092 	 * Currently we don't know the generation for parent directory, so
1093 	 * a generation of 0 means "accept any"
1094 	 */
1095 	inode = ext4_iget_normal(sb, ino);
1096 	if (IS_ERR(inode))
1097 		return ERR_CAST(inode);
1098 	if (generation && inode->i_generation != generation) {
1099 		iput(inode);
1100 		return ERR_PTR(-ESTALE);
1101 	}
1102 
1103 	return inode;
1104 }
1105 
1106 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1107 					int fh_len, int fh_type)
1108 {
1109 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1110 				    ext4_nfs_get_inode);
1111 }
1112 
1113 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1114 					int fh_len, int fh_type)
1115 {
1116 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1117 				    ext4_nfs_get_inode);
1118 }
1119 
1120 /*
1121  * Try to release metadata pages (indirect blocks, directories) which are
1122  * mapped via the block device.  Since these pages could have journal heads
1123  * which would prevent try_to_free_buffers() from freeing them, we must use
1124  * jbd2 layer's try_to_free_buffers() function to release them.
1125  */
1126 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1127 				 gfp_t wait)
1128 {
1129 	journal_t *journal = EXT4_SB(sb)->s_journal;
1130 
1131 	WARN_ON(PageChecked(page));
1132 	if (!page_has_buffers(page))
1133 		return 0;
1134 	if (journal)
1135 		return jbd2_journal_try_to_free_buffers(journal, page,
1136 						wait & ~__GFP_DIRECT_RECLAIM);
1137 	return try_to_free_buffers(page);
1138 }
1139 
1140 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1141 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1142 {
1143 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1144 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1145 }
1146 
1147 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1148 							void *fs_data)
1149 {
1150 	handle_t *handle = fs_data;
1151 	int res, res2, credits, retries = 0;
1152 
1153 	/*
1154 	 * Encrypting the root directory is not allowed because e2fsck expects
1155 	 * lost+found to exist and be unencrypted, and encrypting the root
1156 	 * directory would imply encrypting the lost+found directory as well as
1157 	 * the filename "lost+found" itself.
1158 	 */
1159 	if (inode->i_ino == EXT4_ROOT_INO)
1160 		return -EPERM;
1161 
1162 	res = ext4_convert_inline_data(inode);
1163 	if (res)
1164 		return res;
1165 
1166 	/*
1167 	 * If a journal handle was specified, then the encryption context is
1168 	 * being set on a new inode via inheritance and is part of a larger
1169 	 * transaction to create the inode.  Otherwise the encryption context is
1170 	 * being set on an existing inode in its own transaction.  Only in the
1171 	 * latter case should the "retry on ENOSPC" logic be used.
1172 	 */
1173 
1174 	if (handle) {
1175 		res = ext4_xattr_set_handle(handle, inode,
1176 					    EXT4_XATTR_INDEX_ENCRYPTION,
1177 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1178 					    ctx, len, 0);
1179 		if (!res) {
1180 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1181 			ext4_clear_inode_state(inode,
1182 					EXT4_STATE_MAY_INLINE_DATA);
1183 			/*
1184 			 * Update inode->i_flags - e.g. S_DAX may get disabled
1185 			 */
1186 			ext4_set_inode_flags(inode);
1187 		}
1188 		return res;
1189 	}
1190 
1191 	res = dquot_initialize(inode);
1192 	if (res)
1193 		return res;
1194 retry:
1195 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1196 				     &credits);
1197 	if (res)
1198 		return res;
1199 
1200 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1201 	if (IS_ERR(handle))
1202 		return PTR_ERR(handle);
1203 
1204 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1205 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1206 				    ctx, len, 0);
1207 	if (!res) {
1208 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1209 		/* Update inode->i_flags - e.g. S_DAX may get disabled */
1210 		ext4_set_inode_flags(inode);
1211 		res = ext4_mark_inode_dirty(handle, inode);
1212 		if (res)
1213 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1214 	}
1215 	res2 = ext4_journal_stop(handle);
1216 
1217 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1218 		goto retry;
1219 	if (!res)
1220 		res = res2;
1221 	return res;
1222 }
1223 
1224 static bool ext4_dummy_context(struct inode *inode)
1225 {
1226 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1227 }
1228 
1229 static unsigned ext4_max_namelen(struct inode *inode)
1230 {
1231 	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1232 		EXT4_NAME_LEN;
1233 }
1234 
1235 static const struct fscrypt_operations ext4_cryptops = {
1236 	.key_prefix		= "ext4:",
1237 	.get_context		= ext4_get_context,
1238 	.set_context		= ext4_set_context,
1239 	.dummy_context		= ext4_dummy_context,
1240 	.is_encrypted		= ext4_encrypted_inode,
1241 	.empty_dir		= ext4_empty_dir,
1242 	.max_namelen		= ext4_max_namelen,
1243 };
1244 #else
1245 static const struct fscrypt_operations ext4_cryptops = {
1246 	.is_encrypted		= ext4_encrypted_inode,
1247 };
1248 #endif
1249 
1250 #ifdef CONFIG_QUOTA
1251 static const char * const quotatypes[] = INITQFNAMES;
1252 #define QTYPE2NAME(t) (quotatypes[t])
1253 
1254 static int ext4_write_dquot(struct dquot *dquot);
1255 static int ext4_acquire_dquot(struct dquot *dquot);
1256 static int ext4_release_dquot(struct dquot *dquot);
1257 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1258 static int ext4_write_info(struct super_block *sb, int type);
1259 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1260 			 const struct path *path);
1261 static int ext4_quota_on_mount(struct super_block *sb, int type);
1262 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1263 			       size_t len, loff_t off);
1264 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1265 				const char *data, size_t len, loff_t off);
1266 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1267 			     unsigned int flags);
1268 static int ext4_enable_quotas(struct super_block *sb);
1269 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1270 
1271 static struct dquot **ext4_get_dquots(struct inode *inode)
1272 {
1273 	return EXT4_I(inode)->i_dquot;
1274 }
1275 
1276 static const struct dquot_operations ext4_quota_operations = {
1277 	.get_reserved_space	= ext4_get_reserved_space,
1278 	.write_dquot		= ext4_write_dquot,
1279 	.acquire_dquot		= ext4_acquire_dquot,
1280 	.release_dquot		= ext4_release_dquot,
1281 	.mark_dirty		= ext4_mark_dquot_dirty,
1282 	.write_info		= ext4_write_info,
1283 	.alloc_dquot		= dquot_alloc,
1284 	.destroy_dquot		= dquot_destroy,
1285 	.get_projid		= ext4_get_projid,
1286 	.get_inode_usage	= ext4_get_inode_usage,
1287 	.get_next_id		= ext4_get_next_id,
1288 };
1289 
1290 static const struct quotactl_ops ext4_qctl_operations = {
1291 	.quota_on	= ext4_quota_on,
1292 	.quota_off	= ext4_quota_off,
1293 	.quota_sync	= dquot_quota_sync,
1294 	.get_state	= dquot_get_state,
1295 	.set_info	= dquot_set_dqinfo,
1296 	.get_dqblk	= dquot_get_dqblk,
1297 	.set_dqblk	= dquot_set_dqblk,
1298 	.get_nextdqblk	= dquot_get_next_dqblk,
1299 };
1300 #endif
1301 
1302 static const struct super_operations ext4_sops = {
1303 	.alloc_inode	= ext4_alloc_inode,
1304 	.destroy_inode	= ext4_destroy_inode,
1305 	.write_inode	= ext4_write_inode,
1306 	.dirty_inode	= ext4_dirty_inode,
1307 	.drop_inode	= ext4_drop_inode,
1308 	.evict_inode	= ext4_evict_inode,
1309 	.put_super	= ext4_put_super,
1310 	.sync_fs	= ext4_sync_fs,
1311 	.freeze_fs	= ext4_freeze,
1312 	.unfreeze_fs	= ext4_unfreeze,
1313 	.statfs		= ext4_statfs,
1314 	.remount_fs	= ext4_remount,
1315 	.show_options	= ext4_show_options,
1316 #ifdef CONFIG_QUOTA
1317 	.quota_read	= ext4_quota_read,
1318 	.quota_write	= ext4_quota_write,
1319 	.get_dquots	= ext4_get_dquots,
1320 #endif
1321 	.bdev_try_to_free_page = bdev_try_to_free_page,
1322 };
1323 
1324 static const struct export_operations ext4_export_ops = {
1325 	.fh_to_dentry = ext4_fh_to_dentry,
1326 	.fh_to_parent = ext4_fh_to_parent,
1327 	.get_parent = ext4_get_parent,
1328 };
1329 
1330 enum {
1331 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1332 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1333 	Opt_nouid32, Opt_debug, Opt_removed,
1334 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1335 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1336 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1337 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1338 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1339 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1340 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1341 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1342 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1343 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1344 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1345 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1346 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1347 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1348 	Opt_dioread_nolock, Opt_dioread_lock,
1349 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1350 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1351 };
1352 
1353 static const match_table_t tokens = {
1354 	{Opt_bsd_df, "bsddf"},
1355 	{Opt_minix_df, "minixdf"},
1356 	{Opt_grpid, "grpid"},
1357 	{Opt_grpid, "bsdgroups"},
1358 	{Opt_nogrpid, "nogrpid"},
1359 	{Opt_nogrpid, "sysvgroups"},
1360 	{Opt_resgid, "resgid=%u"},
1361 	{Opt_resuid, "resuid=%u"},
1362 	{Opt_sb, "sb=%u"},
1363 	{Opt_err_cont, "errors=continue"},
1364 	{Opt_err_panic, "errors=panic"},
1365 	{Opt_err_ro, "errors=remount-ro"},
1366 	{Opt_nouid32, "nouid32"},
1367 	{Opt_debug, "debug"},
1368 	{Opt_removed, "oldalloc"},
1369 	{Opt_removed, "orlov"},
1370 	{Opt_user_xattr, "user_xattr"},
1371 	{Opt_nouser_xattr, "nouser_xattr"},
1372 	{Opt_acl, "acl"},
1373 	{Opt_noacl, "noacl"},
1374 	{Opt_noload, "norecovery"},
1375 	{Opt_noload, "noload"},
1376 	{Opt_removed, "nobh"},
1377 	{Opt_removed, "bh"},
1378 	{Opt_commit, "commit=%u"},
1379 	{Opt_min_batch_time, "min_batch_time=%u"},
1380 	{Opt_max_batch_time, "max_batch_time=%u"},
1381 	{Opt_journal_dev, "journal_dev=%u"},
1382 	{Opt_journal_path, "journal_path=%s"},
1383 	{Opt_journal_checksum, "journal_checksum"},
1384 	{Opt_nojournal_checksum, "nojournal_checksum"},
1385 	{Opt_journal_async_commit, "journal_async_commit"},
1386 	{Opt_abort, "abort"},
1387 	{Opt_data_journal, "data=journal"},
1388 	{Opt_data_ordered, "data=ordered"},
1389 	{Opt_data_writeback, "data=writeback"},
1390 	{Opt_data_err_abort, "data_err=abort"},
1391 	{Opt_data_err_ignore, "data_err=ignore"},
1392 	{Opt_offusrjquota, "usrjquota="},
1393 	{Opt_usrjquota, "usrjquota=%s"},
1394 	{Opt_offgrpjquota, "grpjquota="},
1395 	{Opt_grpjquota, "grpjquota=%s"},
1396 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1397 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1398 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1399 	{Opt_grpquota, "grpquota"},
1400 	{Opt_noquota, "noquota"},
1401 	{Opt_quota, "quota"},
1402 	{Opt_usrquota, "usrquota"},
1403 	{Opt_prjquota, "prjquota"},
1404 	{Opt_barrier, "barrier=%u"},
1405 	{Opt_barrier, "barrier"},
1406 	{Opt_nobarrier, "nobarrier"},
1407 	{Opt_i_version, "i_version"},
1408 	{Opt_dax, "dax"},
1409 	{Opt_stripe, "stripe=%u"},
1410 	{Opt_delalloc, "delalloc"},
1411 	{Opt_lazytime, "lazytime"},
1412 	{Opt_nolazytime, "nolazytime"},
1413 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1414 	{Opt_nodelalloc, "nodelalloc"},
1415 	{Opt_removed, "mblk_io_submit"},
1416 	{Opt_removed, "nomblk_io_submit"},
1417 	{Opt_block_validity, "block_validity"},
1418 	{Opt_noblock_validity, "noblock_validity"},
1419 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1420 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1421 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1422 	{Opt_auto_da_alloc, "auto_da_alloc"},
1423 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1424 	{Opt_dioread_nolock, "dioread_nolock"},
1425 	{Opt_dioread_lock, "dioread_lock"},
1426 	{Opt_discard, "discard"},
1427 	{Opt_nodiscard, "nodiscard"},
1428 	{Opt_init_itable, "init_itable=%u"},
1429 	{Opt_init_itable, "init_itable"},
1430 	{Opt_noinit_itable, "noinit_itable"},
1431 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1432 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1433 	{Opt_nombcache, "nombcache"},
1434 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1435 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1436 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1437 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1438 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1439 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1440 	{Opt_err, NULL},
1441 };
1442 
1443 static ext4_fsblk_t get_sb_block(void **data)
1444 {
1445 	ext4_fsblk_t	sb_block;
1446 	char		*options = (char *) *data;
1447 
1448 	if (!options || strncmp(options, "sb=", 3) != 0)
1449 		return 1;	/* Default location */
1450 
1451 	options += 3;
1452 	/* TODO: use simple_strtoll with >32bit ext4 */
1453 	sb_block = simple_strtoul(options, &options, 0);
1454 	if (*options && *options != ',') {
1455 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1456 		       (char *) *data);
1457 		return 1;
1458 	}
1459 	if (*options == ',')
1460 		options++;
1461 	*data = (void *) options;
1462 
1463 	return sb_block;
1464 }
1465 
1466 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1467 static const char deprecated_msg[] =
1468 	"Mount option \"%s\" will be removed by %s\n"
1469 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1470 
1471 #ifdef CONFIG_QUOTA
1472 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1473 {
1474 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1475 	char *qname;
1476 	int ret = -1;
1477 
1478 	if (sb_any_quota_loaded(sb) &&
1479 		!sbi->s_qf_names[qtype]) {
1480 		ext4_msg(sb, KERN_ERR,
1481 			"Cannot change journaled "
1482 			"quota options when quota turned on");
1483 		return -1;
1484 	}
1485 	if (ext4_has_feature_quota(sb)) {
1486 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1487 			 "ignored when QUOTA feature is enabled");
1488 		return 1;
1489 	}
1490 	qname = match_strdup(args);
1491 	if (!qname) {
1492 		ext4_msg(sb, KERN_ERR,
1493 			"Not enough memory for storing quotafile name");
1494 		return -1;
1495 	}
1496 	if (sbi->s_qf_names[qtype]) {
1497 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1498 			ret = 1;
1499 		else
1500 			ext4_msg(sb, KERN_ERR,
1501 				 "%s quota file already specified",
1502 				 QTYPE2NAME(qtype));
1503 		goto errout;
1504 	}
1505 	if (strchr(qname, '/')) {
1506 		ext4_msg(sb, KERN_ERR,
1507 			"quotafile must be on filesystem root");
1508 		goto errout;
1509 	}
1510 	sbi->s_qf_names[qtype] = qname;
1511 	set_opt(sb, QUOTA);
1512 	return 1;
1513 errout:
1514 	kfree(qname);
1515 	return ret;
1516 }
1517 
1518 static int clear_qf_name(struct super_block *sb, int qtype)
1519 {
1520 
1521 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1522 
1523 	if (sb_any_quota_loaded(sb) &&
1524 		sbi->s_qf_names[qtype]) {
1525 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1526 			" when quota turned on");
1527 		return -1;
1528 	}
1529 	kfree(sbi->s_qf_names[qtype]);
1530 	sbi->s_qf_names[qtype] = NULL;
1531 	return 1;
1532 }
1533 #endif
1534 
1535 #define MOPT_SET	0x0001
1536 #define MOPT_CLEAR	0x0002
1537 #define MOPT_NOSUPPORT	0x0004
1538 #define MOPT_EXPLICIT	0x0008
1539 #define MOPT_CLEAR_ERR	0x0010
1540 #define MOPT_GTE0	0x0020
1541 #ifdef CONFIG_QUOTA
1542 #define MOPT_Q		0
1543 #define MOPT_QFMT	0x0040
1544 #else
1545 #define MOPT_Q		MOPT_NOSUPPORT
1546 #define MOPT_QFMT	MOPT_NOSUPPORT
1547 #endif
1548 #define MOPT_DATAJ	0x0080
1549 #define MOPT_NO_EXT2	0x0100
1550 #define MOPT_NO_EXT3	0x0200
1551 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1552 #define MOPT_STRING	0x0400
1553 
1554 static const struct mount_opts {
1555 	int	token;
1556 	int	mount_opt;
1557 	int	flags;
1558 } ext4_mount_opts[] = {
1559 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1560 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1561 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1562 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1563 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1564 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1565 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1566 	 MOPT_EXT4_ONLY | MOPT_SET},
1567 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1568 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1569 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1570 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1571 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1572 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1573 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1574 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1575 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1576 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1577 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1578 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1579 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1580 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1581 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1582 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1583 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1584 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1585 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1586 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1587 	 MOPT_NO_EXT2},
1588 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1589 	 MOPT_NO_EXT2},
1590 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1591 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1592 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1593 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1594 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1595 	{Opt_commit, 0, MOPT_GTE0},
1596 	{Opt_max_batch_time, 0, MOPT_GTE0},
1597 	{Opt_min_batch_time, 0, MOPT_GTE0},
1598 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1599 	{Opt_init_itable, 0, MOPT_GTE0},
1600 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1601 	{Opt_stripe, 0, MOPT_GTE0},
1602 	{Opt_resuid, 0, MOPT_GTE0},
1603 	{Opt_resgid, 0, MOPT_GTE0},
1604 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1605 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1606 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1607 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1608 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1609 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1610 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1611 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1612 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1613 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1614 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1615 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1616 #else
1617 	{Opt_acl, 0, MOPT_NOSUPPORT},
1618 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1619 #endif
1620 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1621 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1622 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1623 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1624 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1625 							MOPT_SET | MOPT_Q},
1626 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1627 							MOPT_SET | MOPT_Q},
1628 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1629 							MOPT_SET | MOPT_Q},
1630 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1631 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1632 							MOPT_CLEAR | MOPT_Q},
1633 	{Opt_usrjquota, 0, MOPT_Q},
1634 	{Opt_grpjquota, 0, MOPT_Q},
1635 	{Opt_offusrjquota, 0, MOPT_Q},
1636 	{Opt_offgrpjquota, 0, MOPT_Q},
1637 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1638 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1639 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1640 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1641 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1642 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1643 	{Opt_err, 0, 0}
1644 };
1645 
1646 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1647 			    substring_t *args, unsigned long *journal_devnum,
1648 			    unsigned int *journal_ioprio, int is_remount)
1649 {
1650 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1651 	const struct mount_opts *m;
1652 	kuid_t uid;
1653 	kgid_t gid;
1654 	int arg = 0;
1655 
1656 #ifdef CONFIG_QUOTA
1657 	if (token == Opt_usrjquota)
1658 		return set_qf_name(sb, USRQUOTA, &args[0]);
1659 	else if (token == Opt_grpjquota)
1660 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1661 	else if (token == Opt_offusrjquota)
1662 		return clear_qf_name(sb, USRQUOTA);
1663 	else if (token == Opt_offgrpjquota)
1664 		return clear_qf_name(sb, GRPQUOTA);
1665 #endif
1666 	switch (token) {
1667 	case Opt_noacl:
1668 	case Opt_nouser_xattr:
1669 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1670 		break;
1671 	case Opt_sb:
1672 		return 1;	/* handled by get_sb_block() */
1673 	case Opt_removed:
1674 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1675 		return 1;
1676 	case Opt_abort:
1677 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1678 		return 1;
1679 	case Opt_i_version:
1680 		sb->s_flags |= MS_I_VERSION;
1681 		return 1;
1682 	case Opt_lazytime:
1683 		sb->s_flags |= MS_LAZYTIME;
1684 		return 1;
1685 	case Opt_nolazytime:
1686 		sb->s_flags &= ~MS_LAZYTIME;
1687 		return 1;
1688 	}
1689 
1690 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1691 		if (token == m->token)
1692 			break;
1693 
1694 	if (m->token == Opt_err) {
1695 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1696 			 "or missing value", opt);
1697 		return -1;
1698 	}
1699 
1700 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1701 		ext4_msg(sb, KERN_ERR,
1702 			 "Mount option \"%s\" incompatible with ext2", opt);
1703 		return -1;
1704 	}
1705 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1706 		ext4_msg(sb, KERN_ERR,
1707 			 "Mount option \"%s\" incompatible with ext3", opt);
1708 		return -1;
1709 	}
1710 
1711 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1712 		return -1;
1713 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1714 		return -1;
1715 	if (m->flags & MOPT_EXPLICIT) {
1716 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1717 			set_opt2(sb, EXPLICIT_DELALLOC);
1718 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1719 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1720 		} else
1721 			return -1;
1722 	}
1723 	if (m->flags & MOPT_CLEAR_ERR)
1724 		clear_opt(sb, ERRORS_MASK);
1725 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1726 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1727 			 "options when quota turned on");
1728 		return -1;
1729 	}
1730 
1731 	if (m->flags & MOPT_NOSUPPORT) {
1732 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1733 	} else if (token == Opt_commit) {
1734 		if (arg == 0)
1735 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1736 		sbi->s_commit_interval = HZ * arg;
1737 	} else if (token == Opt_debug_want_extra_isize) {
1738 		sbi->s_want_extra_isize = arg;
1739 	} else if (token == Opt_max_batch_time) {
1740 		sbi->s_max_batch_time = arg;
1741 	} else if (token == Opt_min_batch_time) {
1742 		sbi->s_min_batch_time = arg;
1743 	} else if (token == Opt_inode_readahead_blks) {
1744 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1745 			ext4_msg(sb, KERN_ERR,
1746 				 "EXT4-fs: inode_readahead_blks must be "
1747 				 "0 or a power of 2 smaller than 2^31");
1748 			return -1;
1749 		}
1750 		sbi->s_inode_readahead_blks = arg;
1751 	} else if (token == Opt_init_itable) {
1752 		set_opt(sb, INIT_INODE_TABLE);
1753 		if (!args->from)
1754 			arg = EXT4_DEF_LI_WAIT_MULT;
1755 		sbi->s_li_wait_mult = arg;
1756 	} else if (token == Opt_max_dir_size_kb) {
1757 		sbi->s_max_dir_size_kb = arg;
1758 	} else if (token == Opt_stripe) {
1759 		sbi->s_stripe = arg;
1760 	} else if (token == Opt_resuid) {
1761 		uid = make_kuid(current_user_ns(), arg);
1762 		if (!uid_valid(uid)) {
1763 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1764 			return -1;
1765 		}
1766 		sbi->s_resuid = uid;
1767 	} else if (token == Opt_resgid) {
1768 		gid = make_kgid(current_user_ns(), arg);
1769 		if (!gid_valid(gid)) {
1770 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1771 			return -1;
1772 		}
1773 		sbi->s_resgid = gid;
1774 	} else if (token == Opt_journal_dev) {
1775 		if (is_remount) {
1776 			ext4_msg(sb, KERN_ERR,
1777 				 "Cannot specify journal on remount");
1778 			return -1;
1779 		}
1780 		*journal_devnum = arg;
1781 	} else if (token == Opt_journal_path) {
1782 		char *journal_path;
1783 		struct inode *journal_inode;
1784 		struct path path;
1785 		int error;
1786 
1787 		if (is_remount) {
1788 			ext4_msg(sb, KERN_ERR,
1789 				 "Cannot specify journal on remount");
1790 			return -1;
1791 		}
1792 		journal_path = match_strdup(&args[0]);
1793 		if (!journal_path) {
1794 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1795 				"journal device string");
1796 			return -1;
1797 		}
1798 
1799 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1800 		if (error) {
1801 			ext4_msg(sb, KERN_ERR, "error: could not find "
1802 				"journal device path: error %d", error);
1803 			kfree(journal_path);
1804 			return -1;
1805 		}
1806 
1807 		journal_inode = d_inode(path.dentry);
1808 		if (!S_ISBLK(journal_inode->i_mode)) {
1809 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1810 				"is not a block device", journal_path);
1811 			path_put(&path);
1812 			kfree(journal_path);
1813 			return -1;
1814 		}
1815 
1816 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1817 		path_put(&path);
1818 		kfree(journal_path);
1819 	} else if (token == Opt_journal_ioprio) {
1820 		if (arg > 7) {
1821 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1822 				 " (must be 0-7)");
1823 			return -1;
1824 		}
1825 		*journal_ioprio =
1826 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1827 	} else if (token == Opt_test_dummy_encryption) {
1828 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1829 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1830 		ext4_msg(sb, KERN_WARNING,
1831 			 "Test dummy encryption mode enabled");
1832 #else
1833 		ext4_msg(sb, KERN_WARNING,
1834 			 "Test dummy encryption mount option ignored");
1835 #endif
1836 	} else if (m->flags & MOPT_DATAJ) {
1837 		if (is_remount) {
1838 			if (!sbi->s_journal)
1839 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1840 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1841 				ext4_msg(sb, KERN_ERR,
1842 					 "Cannot change data mode on remount");
1843 				return -1;
1844 			}
1845 		} else {
1846 			clear_opt(sb, DATA_FLAGS);
1847 			sbi->s_mount_opt |= m->mount_opt;
1848 		}
1849 #ifdef CONFIG_QUOTA
1850 	} else if (m->flags & MOPT_QFMT) {
1851 		if (sb_any_quota_loaded(sb) &&
1852 		    sbi->s_jquota_fmt != m->mount_opt) {
1853 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1854 				 "quota options when quota turned on");
1855 			return -1;
1856 		}
1857 		if (ext4_has_feature_quota(sb)) {
1858 			ext4_msg(sb, KERN_INFO,
1859 				 "Quota format mount options ignored "
1860 				 "when QUOTA feature is enabled");
1861 			return 1;
1862 		}
1863 		sbi->s_jquota_fmt = m->mount_opt;
1864 #endif
1865 	} else if (token == Opt_dax) {
1866 #ifdef CONFIG_FS_DAX
1867 		ext4_msg(sb, KERN_WARNING,
1868 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1869 			sbi->s_mount_opt |= m->mount_opt;
1870 #else
1871 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1872 		return -1;
1873 #endif
1874 	} else if (token == Opt_data_err_abort) {
1875 		sbi->s_mount_opt |= m->mount_opt;
1876 	} else if (token == Opt_data_err_ignore) {
1877 		sbi->s_mount_opt &= ~m->mount_opt;
1878 	} else {
1879 		if (!args->from)
1880 			arg = 1;
1881 		if (m->flags & MOPT_CLEAR)
1882 			arg = !arg;
1883 		else if (unlikely(!(m->flags & MOPT_SET))) {
1884 			ext4_msg(sb, KERN_WARNING,
1885 				 "buggy handling of option %s", opt);
1886 			WARN_ON(1);
1887 			return -1;
1888 		}
1889 		if (arg != 0)
1890 			sbi->s_mount_opt |= m->mount_opt;
1891 		else
1892 			sbi->s_mount_opt &= ~m->mount_opt;
1893 	}
1894 	return 1;
1895 }
1896 
1897 static int parse_options(char *options, struct super_block *sb,
1898 			 unsigned long *journal_devnum,
1899 			 unsigned int *journal_ioprio,
1900 			 int is_remount)
1901 {
1902 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1903 	char *p;
1904 	substring_t args[MAX_OPT_ARGS];
1905 	int token;
1906 
1907 	if (!options)
1908 		return 1;
1909 
1910 	while ((p = strsep(&options, ",")) != NULL) {
1911 		if (!*p)
1912 			continue;
1913 		/*
1914 		 * Initialize args struct so we know whether arg was
1915 		 * found; some options take optional arguments.
1916 		 */
1917 		args[0].to = args[0].from = NULL;
1918 		token = match_token(p, tokens, args);
1919 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1920 				     journal_ioprio, is_remount) < 0)
1921 			return 0;
1922 	}
1923 #ifdef CONFIG_QUOTA
1924 	/*
1925 	 * We do the test below only for project quotas. 'usrquota' and
1926 	 * 'grpquota' mount options are allowed even without quota feature
1927 	 * to support legacy quotas in quota files.
1928 	 */
1929 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1930 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1931 			 "Cannot enable project quota enforcement.");
1932 		return 0;
1933 	}
1934 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1935 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1936 			clear_opt(sb, USRQUOTA);
1937 
1938 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1939 			clear_opt(sb, GRPQUOTA);
1940 
1941 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1942 			ext4_msg(sb, KERN_ERR, "old and new quota "
1943 					"format mixing");
1944 			return 0;
1945 		}
1946 
1947 		if (!sbi->s_jquota_fmt) {
1948 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1949 					"not specified");
1950 			return 0;
1951 		}
1952 	}
1953 #endif
1954 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1955 		int blocksize =
1956 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1957 
1958 		if (blocksize < PAGE_SIZE) {
1959 			ext4_msg(sb, KERN_ERR, "can't mount with "
1960 				 "dioread_nolock if block size != PAGE_SIZE");
1961 			return 0;
1962 		}
1963 	}
1964 	return 1;
1965 }
1966 
1967 static inline void ext4_show_quota_options(struct seq_file *seq,
1968 					   struct super_block *sb)
1969 {
1970 #if defined(CONFIG_QUOTA)
1971 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1972 
1973 	if (sbi->s_jquota_fmt) {
1974 		char *fmtname = "";
1975 
1976 		switch (sbi->s_jquota_fmt) {
1977 		case QFMT_VFS_OLD:
1978 			fmtname = "vfsold";
1979 			break;
1980 		case QFMT_VFS_V0:
1981 			fmtname = "vfsv0";
1982 			break;
1983 		case QFMT_VFS_V1:
1984 			fmtname = "vfsv1";
1985 			break;
1986 		}
1987 		seq_printf(seq, ",jqfmt=%s", fmtname);
1988 	}
1989 
1990 	if (sbi->s_qf_names[USRQUOTA])
1991 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1992 
1993 	if (sbi->s_qf_names[GRPQUOTA])
1994 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1995 #endif
1996 }
1997 
1998 static const char *token2str(int token)
1999 {
2000 	const struct match_token *t;
2001 
2002 	for (t = tokens; t->token != Opt_err; t++)
2003 		if (t->token == token && !strchr(t->pattern, '='))
2004 			break;
2005 	return t->pattern;
2006 }
2007 
2008 /*
2009  * Show an option if
2010  *  - it's set to a non-default value OR
2011  *  - if the per-sb default is different from the global default
2012  */
2013 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2014 			      int nodefs)
2015 {
2016 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2017 	struct ext4_super_block *es = sbi->s_es;
2018 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
2019 	const struct mount_opts *m;
2020 	char sep = nodefs ? '\n' : ',';
2021 
2022 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2023 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2024 
2025 	if (sbi->s_sb_block != 1)
2026 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2027 
2028 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2029 		int want_set = m->flags & MOPT_SET;
2030 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2031 		    (m->flags & MOPT_CLEAR_ERR))
2032 			continue;
2033 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2034 			continue; /* skip if same as the default */
2035 		if ((want_set &&
2036 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2037 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2038 			continue; /* select Opt_noFoo vs Opt_Foo */
2039 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2040 	}
2041 
2042 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2043 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2044 		SEQ_OPTS_PRINT("resuid=%u",
2045 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2046 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2047 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2048 		SEQ_OPTS_PRINT("resgid=%u",
2049 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2050 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2051 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2052 		SEQ_OPTS_PUTS("errors=remount-ro");
2053 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2054 		SEQ_OPTS_PUTS("errors=continue");
2055 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2056 		SEQ_OPTS_PUTS("errors=panic");
2057 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2058 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2059 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2060 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2061 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2062 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2063 	if (sb->s_flags & MS_I_VERSION)
2064 		SEQ_OPTS_PUTS("i_version");
2065 	if (nodefs || sbi->s_stripe)
2066 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2067 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2068 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2069 			SEQ_OPTS_PUTS("data=journal");
2070 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2071 			SEQ_OPTS_PUTS("data=ordered");
2072 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2073 			SEQ_OPTS_PUTS("data=writeback");
2074 	}
2075 	if (nodefs ||
2076 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2077 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2078 			       sbi->s_inode_readahead_blks);
2079 
2080 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2081 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2082 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2083 	if (nodefs || sbi->s_max_dir_size_kb)
2084 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2085 	if (test_opt(sb, DATA_ERR_ABORT))
2086 		SEQ_OPTS_PUTS("data_err=abort");
2087 
2088 	ext4_show_quota_options(seq, sb);
2089 	return 0;
2090 }
2091 
2092 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2093 {
2094 	return _ext4_show_options(seq, root->d_sb, 0);
2095 }
2096 
2097 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2098 {
2099 	struct super_block *sb = seq->private;
2100 	int rc;
2101 
2102 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2103 	rc = _ext4_show_options(seq, sb, 1);
2104 	seq_puts(seq, "\n");
2105 	return rc;
2106 }
2107 
2108 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2109 			    int read_only)
2110 {
2111 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2112 	int res = 0;
2113 
2114 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2115 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2116 			 "forcing read-only mode");
2117 		res = MS_RDONLY;
2118 	}
2119 	if (read_only)
2120 		goto done;
2121 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2122 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2123 			 "running e2fsck is recommended");
2124 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2125 		ext4_msg(sb, KERN_WARNING,
2126 			 "warning: mounting fs with errors, "
2127 			 "running e2fsck is recommended");
2128 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2129 		 le16_to_cpu(es->s_mnt_count) >=
2130 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2131 		ext4_msg(sb, KERN_WARNING,
2132 			 "warning: maximal mount count reached, "
2133 			 "running e2fsck is recommended");
2134 	else if (le32_to_cpu(es->s_checkinterval) &&
2135 		(le32_to_cpu(es->s_lastcheck) +
2136 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2137 		ext4_msg(sb, KERN_WARNING,
2138 			 "warning: checktime reached, "
2139 			 "running e2fsck is recommended");
2140 	if (!sbi->s_journal)
2141 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2142 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2143 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2144 	le16_add_cpu(&es->s_mnt_count, 1);
2145 	es->s_mtime = cpu_to_le32(get_seconds());
2146 	ext4_update_dynamic_rev(sb);
2147 	if (sbi->s_journal)
2148 		ext4_set_feature_journal_needs_recovery(sb);
2149 
2150 	ext4_commit_super(sb, 1);
2151 done:
2152 	if (test_opt(sb, DEBUG))
2153 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2154 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2155 			sb->s_blocksize,
2156 			sbi->s_groups_count,
2157 			EXT4_BLOCKS_PER_GROUP(sb),
2158 			EXT4_INODES_PER_GROUP(sb),
2159 			sbi->s_mount_opt, sbi->s_mount_opt2);
2160 
2161 	cleancache_init_fs(sb);
2162 	return res;
2163 }
2164 
2165 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2166 {
2167 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2168 	struct flex_groups *new_groups;
2169 	int size;
2170 
2171 	if (!sbi->s_log_groups_per_flex)
2172 		return 0;
2173 
2174 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2175 	if (size <= sbi->s_flex_groups_allocated)
2176 		return 0;
2177 
2178 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2179 	new_groups = kvzalloc(size, GFP_KERNEL);
2180 	if (!new_groups) {
2181 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2182 			 size / (int) sizeof(struct flex_groups));
2183 		return -ENOMEM;
2184 	}
2185 
2186 	if (sbi->s_flex_groups) {
2187 		memcpy(new_groups, sbi->s_flex_groups,
2188 		       (sbi->s_flex_groups_allocated *
2189 			sizeof(struct flex_groups)));
2190 		kvfree(sbi->s_flex_groups);
2191 	}
2192 	sbi->s_flex_groups = new_groups;
2193 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2194 	return 0;
2195 }
2196 
2197 static int ext4_fill_flex_info(struct super_block *sb)
2198 {
2199 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2200 	struct ext4_group_desc *gdp = NULL;
2201 	ext4_group_t flex_group;
2202 	int i, err;
2203 
2204 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2205 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2206 		sbi->s_log_groups_per_flex = 0;
2207 		return 1;
2208 	}
2209 
2210 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2211 	if (err)
2212 		goto failed;
2213 
2214 	for (i = 0; i < sbi->s_groups_count; i++) {
2215 		gdp = ext4_get_group_desc(sb, i, NULL);
2216 
2217 		flex_group = ext4_flex_group(sbi, i);
2218 		atomic_add(ext4_free_inodes_count(sb, gdp),
2219 			   &sbi->s_flex_groups[flex_group].free_inodes);
2220 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2221 			     &sbi->s_flex_groups[flex_group].free_clusters);
2222 		atomic_add(ext4_used_dirs_count(sb, gdp),
2223 			   &sbi->s_flex_groups[flex_group].used_dirs);
2224 	}
2225 
2226 	return 1;
2227 failed:
2228 	return 0;
2229 }
2230 
2231 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2232 				   struct ext4_group_desc *gdp)
2233 {
2234 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2235 	__u16 crc = 0;
2236 	__le32 le_group = cpu_to_le32(block_group);
2237 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2238 
2239 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2240 		/* Use new metadata_csum algorithm */
2241 		__u32 csum32;
2242 		__u16 dummy_csum = 0;
2243 
2244 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2245 				     sizeof(le_group));
2246 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2247 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2248 				     sizeof(dummy_csum));
2249 		offset += sizeof(dummy_csum);
2250 		if (offset < sbi->s_desc_size)
2251 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2252 					     sbi->s_desc_size - offset);
2253 
2254 		crc = csum32 & 0xFFFF;
2255 		goto out;
2256 	}
2257 
2258 	/* old crc16 code */
2259 	if (!ext4_has_feature_gdt_csum(sb))
2260 		return 0;
2261 
2262 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2263 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2264 	crc = crc16(crc, (__u8 *)gdp, offset);
2265 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2266 	/* for checksum of struct ext4_group_desc do the rest...*/
2267 	if (ext4_has_feature_64bit(sb) &&
2268 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2269 		crc = crc16(crc, (__u8 *)gdp + offset,
2270 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2271 				offset);
2272 
2273 out:
2274 	return cpu_to_le16(crc);
2275 }
2276 
2277 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2278 				struct ext4_group_desc *gdp)
2279 {
2280 	if (ext4_has_group_desc_csum(sb) &&
2281 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2282 		return 0;
2283 
2284 	return 1;
2285 }
2286 
2287 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2288 			      struct ext4_group_desc *gdp)
2289 {
2290 	if (!ext4_has_group_desc_csum(sb))
2291 		return;
2292 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2293 }
2294 
2295 /* Called at mount-time, super-block is locked */
2296 static int ext4_check_descriptors(struct super_block *sb,
2297 				  ext4_fsblk_t sb_block,
2298 				  ext4_group_t *first_not_zeroed)
2299 {
2300 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2301 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2302 	ext4_fsblk_t last_block;
2303 	ext4_fsblk_t block_bitmap;
2304 	ext4_fsblk_t inode_bitmap;
2305 	ext4_fsblk_t inode_table;
2306 	int flexbg_flag = 0;
2307 	ext4_group_t i, grp = sbi->s_groups_count;
2308 
2309 	if (ext4_has_feature_flex_bg(sb))
2310 		flexbg_flag = 1;
2311 
2312 	ext4_debug("Checking group descriptors");
2313 
2314 	for (i = 0; i < sbi->s_groups_count; i++) {
2315 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2316 
2317 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2318 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2319 		else
2320 			last_block = first_block +
2321 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2322 
2323 		if ((grp == sbi->s_groups_count) &&
2324 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2325 			grp = i;
2326 
2327 		block_bitmap = ext4_block_bitmap(sb, gdp);
2328 		if (block_bitmap == sb_block) {
2329 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2330 				 "Block bitmap for group %u overlaps "
2331 				 "superblock", i);
2332 		}
2333 		if (block_bitmap < first_block || block_bitmap > last_block) {
2334 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2335 			       "Block bitmap for group %u not in group "
2336 			       "(block %llu)!", i, block_bitmap);
2337 			return 0;
2338 		}
2339 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2340 		if (inode_bitmap == sb_block) {
2341 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2342 				 "Inode bitmap for group %u overlaps "
2343 				 "superblock", i);
2344 		}
2345 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2346 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2347 			       "Inode bitmap for group %u not in group "
2348 			       "(block %llu)!", i, inode_bitmap);
2349 			return 0;
2350 		}
2351 		inode_table = ext4_inode_table(sb, gdp);
2352 		if (inode_table == sb_block) {
2353 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2354 				 "Inode table for group %u overlaps "
2355 				 "superblock", i);
2356 		}
2357 		if (inode_table < first_block ||
2358 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2359 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2360 			       "Inode table for group %u not in group "
2361 			       "(block %llu)!", i, inode_table);
2362 			return 0;
2363 		}
2364 		ext4_lock_group(sb, i);
2365 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2366 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2367 				 "Checksum for group %u failed (%u!=%u)",
2368 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2369 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2370 			if (!(sb->s_flags & MS_RDONLY)) {
2371 				ext4_unlock_group(sb, i);
2372 				return 0;
2373 			}
2374 		}
2375 		ext4_unlock_group(sb, i);
2376 		if (!flexbg_flag)
2377 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2378 	}
2379 	if (NULL != first_not_zeroed)
2380 		*first_not_zeroed = grp;
2381 	return 1;
2382 }
2383 
2384 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2385  * the superblock) which were deleted from all directories, but held open by
2386  * a process at the time of a crash.  We walk the list and try to delete these
2387  * inodes at recovery time (only with a read-write filesystem).
2388  *
2389  * In order to keep the orphan inode chain consistent during traversal (in
2390  * case of crash during recovery), we link each inode into the superblock
2391  * orphan list_head and handle it the same way as an inode deletion during
2392  * normal operation (which journals the operations for us).
2393  *
2394  * We only do an iget() and an iput() on each inode, which is very safe if we
2395  * accidentally point at an in-use or already deleted inode.  The worst that
2396  * can happen in this case is that we get a "bit already cleared" message from
2397  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2398  * e2fsck was run on this filesystem, and it must have already done the orphan
2399  * inode cleanup for us, so we can safely abort without any further action.
2400  */
2401 static void ext4_orphan_cleanup(struct super_block *sb,
2402 				struct ext4_super_block *es)
2403 {
2404 	unsigned int s_flags = sb->s_flags;
2405 	int ret, nr_orphans = 0, nr_truncates = 0;
2406 #ifdef CONFIG_QUOTA
2407 	int i;
2408 #endif
2409 	if (!es->s_last_orphan) {
2410 		jbd_debug(4, "no orphan inodes to clean up\n");
2411 		return;
2412 	}
2413 
2414 	if (bdev_read_only(sb->s_bdev)) {
2415 		ext4_msg(sb, KERN_ERR, "write access "
2416 			"unavailable, skipping orphan cleanup");
2417 		return;
2418 	}
2419 
2420 	/* Check if feature set would not allow a r/w mount */
2421 	if (!ext4_feature_set_ok(sb, 0)) {
2422 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2423 			 "unknown ROCOMPAT features");
2424 		return;
2425 	}
2426 
2427 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2428 		/* don't clear list on RO mount w/ errors */
2429 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2430 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2431 				  "clearing orphan list.\n");
2432 			es->s_last_orphan = 0;
2433 		}
2434 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2435 		return;
2436 	}
2437 
2438 	if (s_flags & MS_RDONLY) {
2439 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2440 		sb->s_flags &= ~MS_RDONLY;
2441 	}
2442 #ifdef CONFIG_QUOTA
2443 	/* Needed for iput() to work correctly and not trash data */
2444 	sb->s_flags |= MS_ACTIVE;
2445 	/* Turn on quotas so that they are updated correctly */
2446 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2447 		if (EXT4_SB(sb)->s_qf_names[i]) {
2448 			int ret = ext4_quota_on_mount(sb, i);
2449 			if (ret < 0)
2450 				ext4_msg(sb, KERN_ERR,
2451 					"Cannot turn on journaled "
2452 					"quota: error %d", ret);
2453 		}
2454 	}
2455 #endif
2456 
2457 	while (es->s_last_orphan) {
2458 		struct inode *inode;
2459 
2460 		/*
2461 		 * We may have encountered an error during cleanup; if
2462 		 * so, skip the rest.
2463 		 */
2464 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2465 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2466 			es->s_last_orphan = 0;
2467 			break;
2468 		}
2469 
2470 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2471 		if (IS_ERR(inode)) {
2472 			es->s_last_orphan = 0;
2473 			break;
2474 		}
2475 
2476 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2477 		dquot_initialize(inode);
2478 		if (inode->i_nlink) {
2479 			if (test_opt(sb, DEBUG))
2480 				ext4_msg(sb, KERN_DEBUG,
2481 					"%s: truncating inode %lu to %lld bytes",
2482 					__func__, inode->i_ino, inode->i_size);
2483 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2484 				  inode->i_ino, inode->i_size);
2485 			inode_lock(inode);
2486 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2487 			ret = ext4_truncate(inode);
2488 			if (ret)
2489 				ext4_std_error(inode->i_sb, ret);
2490 			inode_unlock(inode);
2491 			nr_truncates++;
2492 		} else {
2493 			if (test_opt(sb, DEBUG))
2494 				ext4_msg(sb, KERN_DEBUG,
2495 					"%s: deleting unreferenced inode %lu",
2496 					__func__, inode->i_ino);
2497 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2498 				  inode->i_ino);
2499 			nr_orphans++;
2500 		}
2501 		iput(inode);  /* The delete magic happens here! */
2502 	}
2503 
2504 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2505 
2506 	if (nr_orphans)
2507 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2508 		       PLURAL(nr_orphans));
2509 	if (nr_truncates)
2510 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2511 		       PLURAL(nr_truncates));
2512 #ifdef CONFIG_QUOTA
2513 	/* Turn quotas off */
2514 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2515 		if (sb_dqopt(sb)->files[i])
2516 			dquot_quota_off(sb, i);
2517 	}
2518 #endif
2519 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2520 }
2521 
2522 /*
2523  * Maximal extent format file size.
2524  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2525  * extent format containers, within a sector_t, and within i_blocks
2526  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2527  * so that won't be a limiting factor.
2528  *
2529  * However there is other limiting factor. We do store extents in the form
2530  * of starting block and length, hence the resulting length of the extent
2531  * covering maximum file size must fit into on-disk format containers as
2532  * well. Given that length is always by 1 unit bigger than max unit (because
2533  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2534  *
2535  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2536  */
2537 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2538 {
2539 	loff_t res;
2540 	loff_t upper_limit = MAX_LFS_FILESIZE;
2541 
2542 	/* small i_blocks in vfs inode? */
2543 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2544 		/*
2545 		 * CONFIG_LBDAF is not enabled implies the inode
2546 		 * i_block represent total blocks in 512 bytes
2547 		 * 32 == size of vfs inode i_blocks * 8
2548 		 */
2549 		upper_limit = (1LL << 32) - 1;
2550 
2551 		/* total blocks in file system block size */
2552 		upper_limit >>= (blkbits - 9);
2553 		upper_limit <<= blkbits;
2554 	}
2555 
2556 	/*
2557 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2558 	 * by one fs block, so ee_len can cover the extent of maximum file
2559 	 * size
2560 	 */
2561 	res = (1LL << 32) - 1;
2562 	res <<= blkbits;
2563 
2564 	/* Sanity check against vm- & vfs- imposed limits */
2565 	if (res > upper_limit)
2566 		res = upper_limit;
2567 
2568 	return res;
2569 }
2570 
2571 /*
2572  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2573  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2574  * We need to be 1 filesystem block less than the 2^48 sector limit.
2575  */
2576 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2577 {
2578 	loff_t res = EXT4_NDIR_BLOCKS;
2579 	int meta_blocks;
2580 	loff_t upper_limit;
2581 	/* This is calculated to be the largest file size for a dense, block
2582 	 * mapped file such that the file's total number of 512-byte sectors,
2583 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2584 	 *
2585 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2586 	 * number of 512-byte sectors of the file.
2587 	 */
2588 
2589 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2590 		/*
2591 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2592 		 * the inode i_block field represents total file blocks in
2593 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2594 		 */
2595 		upper_limit = (1LL << 32) - 1;
2596 
2597 		/* total blocks in file system block size */
2598 		upper_limit >>= (bits - 9);
2599 
2600 	} else {
2601 		/*
2602 		 * We use 48 bit ext4_inode i_blocks
2603 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2604 		 * represent total number of blocks in
2605 		 * file system block size
2606 		 */
2607 		upper_limit = (1LL << 48) - 1;
2608 
2609 	}
2610 
2611 	/* indirect blocks */
2612 	meta_blocks = 1;
2613 	/* double indirect blocks */
2614 	meta_blocks += 1 + (1LL << (bits-2));
2615 	/* tripple indirect blocks */
2616 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2617 
2618 	upper_limit -= meta_blocks;
2619 	upper_limit <<= bits;
2620 
2621 	res += 1LL << (bits-2);
2622 	res += 1LL << (2*(bits-2));
2623 	res += 1LL << (3*(bits-2));
2624 	res <<= bits;
2625 	if (res > upper_limit)
2626 		res = upper_limit;
2627 
2628 	if (res > MAX_LFS_FILESIZE)
2629 		res = MAX_LFS_FILESIZE;
2630 
2631 	return res;
2632 }
2633 
2634 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2635 				   ext4_fsblk_t logical_sb_block, int nr)
2636 {
2637 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2638 	ext4_group_t bg, first_meta_bg;
2639 	int has_super = 0;
2640 
2641 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2642 
2643 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2644 		return logical_sb_block + nr + 1;
2645 	bg = sbi->s_desc_per_block * nr;
2646 	if (ext4_bg_has_super(sb, bg))
2647 		has_super = 1;
2648 
2649 	/*
2650 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2651 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2652 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2653 	 * compensate.
2654 	 */
2655 	if (sb->s_blocksize == 1024 && nr == 0 &&
2656 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2657 		has_super++;
2658 
2659 	return (has_super + ext4_group_first_block_no(sb, bg));
2660 }
2661 
2662 /**
2663  * ext4_get_stripe_size: Get the stripe size.
2664  * @sbi: In memory super block info
2665  *
2666  * If we have specified it via mount option, then
2667  * use the mount option value. If the value specified at mount time is
2668  * greater than the blocks per group use the super block value.
2669  * If the super block value is greater than blocks per group return 0.
2670  * Allocator needs it be less than blocks per group.
2671  *
2672  */
2673 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2674 {
2675 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2676 	unsigned long stripe_width =
2677 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2678 	int ret;
2679 
2680 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2681 		ret = sbi->s_stripe;
2682 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2683 		ret = stripe_width;
2684 	else if (stride && stride <= sbi->s_blocks_per_group)
2685 		ret = stride;
2686 	else
2687 		ret = 0;
2688 
2689 	/*
2690 	 * If the stripe width is 1, this makes no sense and
2691 	 * we set it to 0 to turn off stripe handling code.
2692 	 */
2693 	if (ret <= 1)
2694 		ret = 0;
2695 
2696 	return ret;
2697 }
2698 
2699 /*
2700  * Check whether this filesystem can be mounted based on
2701  * the features present and the RDONLY/RDWR mount requested.
2702  * Returns 1 if this filesystem can be mounted as requested,
2703  * 0 if it cannot be.
2704  */
2705 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2706 {
2707 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2708 		ext4_msg(sb, KERN_ERR,
2709 			"Couldn't mount because of "
2710 			"unsupported optional features (%x)",
2711 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2712 			~EXT4_FEATURE_INCOMPAT_SUPP));
2713 		return 0;
2714 	}
2715 
2716 	if (readonly)
2717 		return 1;
2718 
2719 	if (ext4_has_feature_readonly(sb)) {
2720 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2721 		sb->s_flags |= MS_RDONLY;
2722 		return 1;
2723 	}
2724 
2725 	/* Check that feature set is OK for a read-write mount */
2726 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2727 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2728 			 "unsupported optional features (%x)",
2729 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2730 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2731 		return 0;
2732 	}
2733 	/*
2734 	 * Large file size enabled file system can only be mounted
2735 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2736 	 */
2737 	if (ext4_has_feature_huge_file(sb)) {
2738 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2739 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2740 				 "cannot be mounted RDWR without "
2741 				 "CONFIG_LBDAF");
2742 			return 0;
2743 		}
2744 	}
2745 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2746 		ext4_msg(sb, KERN_ERR,
2747 			 "Can't support bigalloc feature without "
2748 			 "extents feature\n");
2749 		return 0;
2750 	}
2751 
2752 #ifndef CONFIG_QUOTA
2753 	if (ext4_has_feature_quota(sb) && !readonly) {
2754 		ext4_msg(sb, KERN_ERR,
2755 			 "Filesystem with quota feature cannot be mounted RDWR "
2756 			 "without CONFIG_QUOTA");
2757 		return 0;
2758 	}
2759 	if (ext4_has_feature_project(sb) && !readonly) {
2760 		ext4_msg(sb, KERN_ERR,
2761 			 "Filesystem with project quota feature cannot be mounted RDWR "
2762 			 "without CONFIG_QUOTA");
2763 		return 0;
2764 	}
2765 #endif  /* CONFIG_QUOTA */
2766 	return 1;
2767 }
2768 
2769 /*
2770  * This function is called once a day if we have errors logged
2771  * on the file system
2772  */
2773 static void print_daily_error_info(unsigned long arg)
2774 {
2775 	struct super_block *sb = (struct super_block *) arg;
2776 	struct ext4_sb_info *sbi;
2777 	struct ext4_super_block *es;
2778 
2779 	sbi = EXT4_SB(sb);
2780 	es = sbi->s_es;
2781 
2782 	if (es->s_error_count)
2783 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2784 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2785 			 le32_to_cpu(es->s_error_count));
2786 	if (es->s_first_error_time) {
2787 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2788 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2789 		       (int) sizeof(es->s_first_error_func),
2790 		       es->s_first_error_func,
2791 		       le32_to_cpu(es->s_first_error_line));
2792 		if (es->s_first_error_ino)
2793 			printk(KERN_CONT ": inode %u",
2794 			       le32_to_cpu(es->s_first_error_ino));
2795 		if (es->s_first_error_block)
2796 			printk(KERN_CONT ": block %llu", (unsigned long long)
2797 			       le64_to_cpu(es->s_first_error_block));
2798 		printk(KERN_CONT "\n");
2799 	}
2800 	if (es->s_last_error_time) {
2801 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2802 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2803 		       (int) sizeof(es->s_last_error_func),
2804 		       es->s_last_error_func,
2805 		       le32_to_cpu(es->s_last_error_line));
2806 		if (es->s_last_error_ino)
2807 			printk(KERN_CONT ": inode %u",
2808 			       le32_to_cpu(es->s_last_error_ino));
2809 		if (es->s_last_error_block)
2810 			printk(KERN_CONT ": block %llu", (unsigned long long)
2811 			       le64_to_cpu(es->s_last_error_block));
2812 		printk(KERN_CONT "\n");
2813 	}
2814 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2815 }
2816 
2817 /* Find next suitable group and run ext4_init_inode_table */
2818 static int ext4_run_li_request(struct ext4_li_request *elr)
2819 {
2820 	struct ext4_group_desc *gdp = NULL;
2821 	ext4_group_t group, ngroups;
2822 	struct super_block *sb;
2823 	unsigned long timeout = 0;
2824 	int ret = 0;
2825 
2826 	sb = elr->lr_super;
2827 	ngroups = EXT4_SB(sb)->s_groups_count;
2828 
2829 	for (group = elr->lr_next_group; group < ngroups; group++) {
2830 		gdp = ext4_get_group_desc(sb, group, NULL);
2831 		if (!gdp) {
2832 			ret = 1;
2833 			break;
2834 		}
2835 
2836 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2837 			break;
2838 	}
2839 
2840 	if (group >= ngroups)
2841 		ret = 1;
2842 
2843 	if (!ret) {
2844 		timeout = jiffies;
2845 		ret = ext4_init_inode_table(sb, group,
2846 					    elr->lr_timeout ? 0 : 1);
2847 		if (elr->lr_timeout == 0) {
2848 			timeout = (jiffies - timeout) *
2849 				  elr->lr_sbi->s_li_wait_mult;
2850 			elr->lr_timeout = timeout;
2851 		}
2852 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2853 		elr->lr_next_group = group + 1;
2854 	}
2855 	return ret;
2856 }
2857 
2858 /*
2859  * Remove lr_request from the list_request and free the
2860  * request structure. Should be called with li_list_mtx held
2861  */
2862 static void ext4_remove_li_request(struct ext4_li_request *elr)
2863 {
2864 	struct ext4_sb_info *sbi;
2865 
2866 	if (!elr)
2867 		return;
2868 
2869 	sbi = elr->lr_sbi;
2870 
2871 	list_del(&elr->lr_request);
2872 	sbi->s_li_request = NULL;
2873 	kfree(elr);
2874 }
2875 
2876 static void ext4_unregister_li_request(struct super_block *sb)
2877 {
2878 	mutex_lock(&ext4_li_mtx);
2879 	if (!ext4_li_info) {
2880 		mutex_unlock(&ext4_li_mtx);
2881 		return;
2882 	}
2883 
2884 	mutex_lock(&ext4_li_info->li_list_mtx);
2885 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2886 	mutex_unlock(&ext4_li_info->li_list_mtx);
2887 	mutex_unlock(&ext4_li_mtx);
2888 }
2889 
2890 static struct task_struct *ext4_lazyinit_task;
2891 
2892 /*
2893  * This is the function where ext4lazyinit thread lives. It walks
2894  * through the request list searching for next scheduled filesystem.
2895  * When such a fs is found, run the lazy initialization request
2896  * (ext4_rn_li_request) and keep track of the time spend in this
2897  * function. Based on that time we compute next schedule time of
2898  * the request. When walking through the list is complete, compute
2899  * next waking time and put itself into sleep.
2900  */
2901 static int ext4_lazyinit_thread(void *arg)
2902 {
2903 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2904 	struct list_head *pos, *n;
2905 	struct ext4_li_request *elr;
2906 	unsigned long next_wakeup, cur;
2907 
2908 	BUG_ON(NULL == eli);
2909 
2910 cont_thread:
2911 	while (true) {
2912 		next_wakeup = MAX_JIFFY_OFFSET;
2913 
2914 		mutex_lock(&eli->li_list_mtx);
2915 		if (list_empty(&eli->li_request_list)) {
2916 			mutex_unlock(&eli->li_list_mtx);
2917 			goto exit_thread;
2918 		}
2919 		list_for_each_safe(pos, n, &eli->li_request_list) {
2920 			int err = 0;
2921 			int progress = 0;
2922 			elr = list_entry(pos, struct ext4_li_request,
2923 					 lr_request);
2924 
2925 			if (time_before(jiffies, elr->lr_next_sched)) {
2926 				if (time_before(elr->lr_next_sched, next_wakeup))
2927 					next_wakeup = elr->lr_next_sched;
2928 				continue;
2929 			}
2930 			if (down_read_trylock(&elr->lr_super->s_umount)) {
2931 				if (sb_start_write_trylock(elr->lr_super)) {
2932 					progress = 1;
2933 					/*
2934 					 * We hold sb->s_umount, sb can not
2935 					 * be removed from the list, it is
2936 					 * now safe to drop li_list_mtx
2937 					 */
2938 					mutex_unlock(&eli->li_list_mtx);
2939 					err = ext4_run_li_request(elr);
2940 					sb_end_write(elr->lr_super);
2941 					mutex_lock(&eli->li_list_mtx);
2942 					n = pos->next;
2943 				}
2944 				up_read((&elr->lr_super->s_umount));
2945 			}
2946 			/* error, remove the lazy_init job */
2947 			if (err) {
2948 				ext4_remove_li_request(elr);
2949 				continue;
2950 			}
2951 			if (!progress) {
2952 				elr->lr_next_sched = jiffies +
2953 					(prandom_u32()
2954 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2955 			}
2956 			if (time_before(elr->lr_next_sched, next_wakeup))
2957 				next_wakeup = elr->lr_next_sched;
2958 		}
2959 		mutex_unlock(&eli->li_list_mtx);
2960 
2961 		try_to_freeze();
2962 
2963 		cur = jiffies;
2964 		if ((time_after_eq(cur, next_wakeup)) ||
2965 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2966 			cond_resched();
2967 			continue;
2968 		}
2969 
2970 		schedule_timeout_interruptible(next_wakeup - cur);
2971 
2972 		if (kthread_should_stop()) {
2973 			ext4_clear_request_list();
2974 			goto exit_thread;
2975 		}
2976 	}
2977 
2978 exit_thread:
2979 	/*
2980 	 * It looks like the request list is empty, but we need
2981 	 * to check it under the li_list_mtx lock, to prevent any
2982 	 * additions into it, and of course we should lock ext4_li_mtx
2983 	 * to atomically free the list and ext4_li_info, because at
2984 	 * this point another ext4 filesystem could be registering
2985 	 * new one.
2986 	 */
2987 	mutex_lock(&ext4_li_mtx);
2988 	mutex_lock(&eli->li_list_mtx);
2989 	if (!list_empty(&eli->li_request_list)) {
2990 		mutex_unlock(&eli->li_list_mtx);
2991 		mutex_unlock(&ext4_li_mtx);
2992 		goto cont_thread;
2993 	}
2994 	mutex_unlock(&eli->li_list_mtx);
2995 	kfree(ext4_li_info);
2996 	ext4_li_info = NULL;
2997 	mutex_unlock(&ext4_li_mtx);
2998 
2999 	return 0;
3000 }
3001 
3002 static void ext4_clear_request_list(void)
3003 {
3004 	struct list_head *pos, *n;
3005 	struct ext4_li_request *elr;
3006 
3007 	mutex_lock(&ext4_li_info->li_list_mtx);
3008 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3009 		elr = list_entry(pos, struct ext4_li_request,
3010 				 lr_request);
3011 		ext4_remove_li_request(elr);
3012 	}
3013 	mutex_unlock(&ext4_li_info->li_list_mtx);
3014 }
3015 
3016 static int ext4_run_lazyinit_thread(void)
3017 {
3018 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3019 					 ext4_li_info, "ext4lazyinit");
3020 	if (IS_ERR(ext4_lazyinit_task)) {
3021 		int err = PTR_ERR(ext4_lazyinit_task);
3022 		ext4_clear_request_list();
3023 		kfree(ext4_li_info);
3024 		ext4_li_info = NULL;
3025 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3026 				 "initialization thread\n",
3027 				 err);
3028 		return err;
3029 	}
3030 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3031 	return 0;
3032 }
3033 
3034 /*
3035  * Check whether it make sense to run itable init. thread or not.
3036  * If there is at least one uninitialized inode table, return
3037  * corresponding group number, else the loop goes through all
3038  * groups and return total number of groups.
3039  */
3040 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3041 {
3042 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3043 	struct ext4_group_desc *gdp = NULL;
3044 
3045 	for (group = 0; group < ngroups; group++) {
3046 		gdp = ext4_get_group_desc(sb, group, NULL);
3047 		if (!gdp)
3048 			continue;
3049 
3050 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3051 			break;
3052 	}
3053 
3054 	return group;
3055 }
3056 
3057 static int ext4_li_info_new(void)
3058 {
3059 	struct ext4_lazy_init *eli = NULL;
3060 
3061 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3062 	if (!eli)
3063 		return -ENOMEM;
3064 
3065 	INIT_LIST_HEAD(&eli->li_request_list);
3066 	mutex_init(&eli->li_list_mtx);
3067 
3068 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3069 
3070 	ext4_li_info = eli;
3071 
3072 	return 0;
3073 }
3074 
3075 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3076 					    ext4_group_t start)
3077 {
3078 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3079 	struct ext4_li_request *elr;
3080 
3081 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3082 	if (!elr)
3083 		return NULL;
3084 
3085 	elr->lr_super = sb;
3086 	elr->lr_sbi = sbi;
3087 	elr->lr_next_group = start;
3088 
3089 	/*
3090 	 * Randomize first schedule time of the request to
3091 	 * spread the inode table initialization requests
3092 	 * better.
3093 	 */
3094 	elr->lr_next_sched = jiffies + (prandom_u32() %
3095 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3096 	return elr;
3097 }
3098 
3099 int ext4_register_li_request(struct super_block *sb,
3100 			     ext4_group_t first_not_zeroed)
3101 {
3102 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3103 	struct ext4_li_request *elr = NULL;
3104 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3105 	int ret = 0;
3106 
3107 	mutex_lock(&ext4_li_mtx);
3108 	if (sbi->s_li_request != NULL) {
3109 		/*
3110 		 * Reset timeout so it can be computed again, because
3111 		 * s_li_wait_mult might have changed.
3112 		 */
3113 		sbi->s_li_request->lr_timeout = 0;
3114 		goto out;
3115 	}
3116 
3117 	if (first_not_zeroed == ngroups ||
3118 	    (sb->s_flags & MS_RDONLY) ||
3119 	    !test_opt(sb, INIT_INODE_TABLE))
3120 		goto out;
3121 
3122 	elr = ext4_li_request_new(sb, first_not_zeroed);
3123 	if (!elr) {
3124 		ret = -ENOMEM;
3125 		goto out;
3126 	}
3127 
3128 	if (NULL == ext4_li_info) {
3129 		ret = ext4_li_info_new();
3130 		if (ret)
3131 			goto out;
3132 	}
3133 
3134 	mutex_lock(&ext4_li_info->li_list_mtx);
3135 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3136 	mutex_unlock(&ext4_li_info->li_list_mtx);
3137 
3138 	sbi->s_li_request = elr;
3139 	/*
3140 	 * set elr to NULL here since it has been inserted to
3141 	 * the request_list and the removal and free of it is
3142 	 * handled by ext4_clear_request_list from now on.
3143 	 */
3144 	elr = NULL;
3145 
3146 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3147 		ret = ext4_run_lazyinit_thread();
3148 		if (ret)
3149 			goto out;
3150 	}
3151 out:
3152 	mutex_unlock(&ext4_li_mtx);
3153 	if (ret)
3154 		kfree(elr);
3155 	return ret;
3156 }
3157 
3158 /*
3159  * We do not need to lock anything since this is called on
3160  * module unload.
3161  */
3162 static void ext4_destroy_lazyinit_thread(void)
3163 {
3164 	/*
3165 	 * If thread exited earlier
3166 	 * there's nothing to be done.
3167 	 */
3168 	if (!ext4_li_info || !ext4_lazyinit_task)
3169 		return;
3170 
3171 	kthread_stop(ext4_lazyinit_task);
3172 }
3173 
3174 static int set_journal_csum_feature_set(struct super_block *sb)
3175 {
3176 	int ret = 1;
3177 	int compat, incompat;
3178 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3179 
3180 	if (ext4_has_metadata_csum(sb)) {
3181 		/* journal checksum v3 */
3182 		compat = 0;
3183 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3184 	} else {
3185 		/* journal checksum v1 */
3186 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3187 		incompat = 0;
3188 	}
3189 
3190 	jbd2_journal_clear_features(sbi->s_journal,
3191 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3192 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3193 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3194 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3195 		ret = jbd2_journal_set_features(sbi->s_journal,
3196 				compat, 0,
3197 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3198 				incompat);
3199 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3200 		ret = jbd2_journal_set_features(sbi->s_journal,
3201 				compat, 0,
3202 				incompat);
3203 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3204 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3205 	} else {
3206 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3207 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3208 	}
3209 
3210 	return ret;
3211 }
3212 
3213 /*
3214  * Note: calculating the overhead so we can be compatible with
3215  * historical BSD practice is quite difficult in the face of
3216  * clusters/bigalloc.  This is because multiple metadata blocks from
3217  * different block group can end up in the same allocation cluster.
3218  * Calculating the exact overhead in the face of clustered allocation
3219  * requires either O(all block bitmaps) in memory or O(number of block
3220  * groups**2) in time.  We will still calculate the superblock for
3221  * older file systems --- and if we come across with a bigalloc file
3222  * system with zero in s_overhead_clusters the estimate will be close to
3223  * correct especially for very large cluster sizes --- but for newer
3224  * file systems, it's better to calculate this figure once at mkfs
3225  * time, and store it in the superblock.  If the superblock value is
3226  * present (even for non-bigalloc file systems), we will use it.
3227  */
3228 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3229 			  char *buf)
3230 {
3231 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3232 	struct ext4_group_desc	*gdp;
3233 	ext4_fsblk_t		first_block, last_block, b;
3234 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3235 	int			s, j, count = 0;
3236 
3237 	if (!ext4_has_feature_bigalloc(sb))
3238 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3239 			sbi->s_itb_per_group + 2);
3240 
3241 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3242 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3243 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3244 	for (i = 0; i < ngroups; i++) {
3245 		gdp = ext4_get_group_desc(sb, i, NULL);
3246 		b = ext4_block_bitmap(sb, gdp);
3247 		if (b >= first_block && b <= last_block) {
3248 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3249 			count++;
3250 		}
3251 		b = ext4_inode_bitmap(sb, gdp);
3252 		if (b >= first_block && b <= last_block) {
3253 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3254 			count++;
3255 		}
3256 		b = ext4_inode_table(sb, gdp);
3257 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3258 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3259 				int c = EXT4_B2C(sbi, b - first_block);
3260 				ext4_set_bit(c, buf);
3261 				count++;
3262 			}
3263 		if (i != grp)
3264 			continue;
3265 		s = 0;
3266 		if (ext4_bg_has_super(sb, grp)) {
3267 			ext4_set_bit(s++, buf);
3268 			count++;
3269 		}
3270 		j = ext4_bg_num_gdb(sb, grp);
3271 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3272 			ext4_error(sb, "Invalid number of block group "
3273 				   "descriptor blocks: %d", j);
3274 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3275 		}
3276 		count += j;
3277 		for (; j > 0; j--)
3278 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3279 	}
3280 	if (!count)
3281 		return 0;
3282 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3283 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3284 }
3285 
3286 /*
3287  * Compute the overhead and stash it in sbi->s_overhead
3288  */
3289 int ext4_calculate_overhead(struct super_block *sb)
3290 {
3291 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3292 	struct ext4_super_block *es = sbi->s_es;
3293 	struct inode *j_inode;
3294 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3295 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3296 	ext4_fsblk_t overhead = 0;
3297 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3298 
3299 	if (!buf)
3300 		return -ENOMEM;
3301 
3302 	/*
3303 	 * Compute the overhead (FS structures).  This is constant
3304 	 * for a given filesystem unless the number of block groups
3305 	 * changes so we cache the previous value until it does.
3306 	 */
3307 
3308 	/*
3309 	 * All of the blocks before first_data_block are overhead
3310 	 */
3311 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3312 
3313 	/*
3314 	 * Add the overhead found in each block group
3315 	 */
3316 	for (i = 0; i < ngroups; i++) {
3317 		int blks;
3318 
3319 		blks = count_overhead(sb, i, buf);
3320 		overhead += blks;
3321 		if (blks)
3322 			memset(buf, 0, PAGE_SIZE);
3323 		cond_resched();
3324 	}
3325 
3326 	/*
3327 	 * Add the internal journal blocks whether the journal has been
3328 	 * loaded or not
3329 	 */
3330 	if (sbi->s_journal && !sbi->journal_bdev)
3331 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3332 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3333 		j_inode = ext4_get_journal_inode(sb, j_inum);
3334 		if (j_inode) {
3335 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3336 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3337 			iput(j_inode);
3338 		} else {
3339 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3340 		}
3341 	}
3342 	sbi->s_overhead = overhead;
3343 	smp_wmb();
3344 	free_page((unsigned long) buf);
3345 	return 0;
3346 }
3347 
3348 static void ext4_set_resv_clusters(struct super_block *sb)
3349 {
3350 	ext4_fsblk_t resv_clusters;
3351 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3352 
3353 	/*
3354 	 * There's no need to reserve anything when we aren't using extents.
3355 	 * The space estimates are exact, there are no unwritten extents,
3356 	 * hole punching doesn't need new metadata... This is needed especially
3357 	 * to keep ext2/3 backward compatibility.
3358 	 */
3359 	if (!ext4_has_feature_extents(sb))
3360 		return;
3361 	/*
3362 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3363 	 * This should cover the situations where we can not afford to run
3364 	 * out of space like for example punch hole, or converting
3365 	 * unwritten extents in delalloc path. In most cases such
3366 	 * allocation would require 1, or 2 blocks, higher numbers are
3367 	 * very rare.
3368 	 */
3369 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3370 			 sbi->s_cluster_bits);
3371 
3372 	do_div(resv_clusters, 50);
3373 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3374 
3375 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3376 }
3377 
3378 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3379 {
3380 	char *orig_data = kstrdup(data, GFP_KERNEL);
3381 	struct buffer_head *bh;
3382 	struct ext4_super_block *es = NULL;
3383 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3384 	ext4_fsblk_t block;
3385 	ext4_fsblk_t sb_block = get_sb_block(&data);
3386 	ext4_fsblk_t logical_sb_block;
3387 	unsigned long offset = 0;
3388 	unsigned long journal_devnum = 0;
3389 	unsigned long def_mount_opts;
3390 	struct inode *root;
3391 	const char *descr;
3392 	int ret = -ENOMEM;
3393 	int blocksize, clustersize;
3394 	unsigned int db_count;
3395 	unsigned int i;
3396 	int needs_recovery, has_huge_files, has_bigalloc;
3397 	__u64 blocks_count;
3398 	int err = 0;
3399 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3400 	ext4_group_t first_not_zeroed;
3401 
3402 	if ((data && !orig_data) || !sbi)
3403 		goto out_free_base;
3404 
3405 	sbi->s_blockgroup_lock =
3406 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3407 	if (!sbi->s_blockgroup_lock)
3408 		goto out_free_base;
3409 
3410 	sb->s_fs_info = sbi;
3411 	sbi->s_sb = sb;
3412 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3413 	sbi->s_sb_block = sb_block;
3414 	if (sb->s_bdev->bd_part)
3415 		sbi->s_sectors_written_start =
3416 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3417 
3418 	/* Cleanup superblock name */
3419 	strreplace(sb->s_id, '/', '!');
3420 
3421 	/* -EINVAL is default */
3422 	ret = -EINVAL;
3423 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3424 	if (!blocksize) {
3425 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3426 		goto out_fail;
3427 	}
3428 
3429 	/*
3430 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3431 	 * block sizes.  We need to calculate the offset from buffer start.
3432 	 */
3433 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3434 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3435 		offset = do_div(logical_sb_block, blocksize);
3436 	} else {
3437 		logical_sb_block = sb_block;
3438 	}
3439 
3440 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3441 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3442 		goto out_fail;
3443 	}
3444 	/*
3445 	 * Note: s_es must be initialized as soon as possible because
3446 	 *       some ext4 macro-instructions depend on its value
3447 	 */
3448 	es = (struct ext4_super_block *) (bh->b_data + offset);
3449 	sbi->s_es = es;
3450 	sb->s_magic = le16_to_cpu(es->s_magic);
3451 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3452 		goto cantfind_ext4;
3453 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3454 
3455 	/* Warn if metadata_csum and gdt_csum are both set. */
3456 	if (ext4_has_feature_metadata_csum(sb) &&
3457 	    ext4_has_feature_gdt_csum(sb))
3458 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3459 			     "redundant flags; please run fsck.");
3460 
3461 	/* Check for a known checksum algorithm */
3462 	if (!ext4_verify_csum_type(sb, es)) {
3463 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3464 			 "unknown checksum algorithm.");
3465 		silent = 1;
3466 		goto cantfind_ext4;
3467 	}
3468 
3469 	/* Load the checksum driver */
3470 	if (ext4_has_feature_metadata_csum(sb) ||
3471 	    ext4_has_feature_ea_inode(sb)) {
3472 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3473 		if (IS_ERR(sbi->s_chksum_driver)) {
3474 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3475 			ret = PTR_ERR(sbi->s_chksum_driver);
3476 			sbi->s_chksum_driver = NULL;
3477 			goto failed_mount;
3478 		}
3479 	}
3480 
3481 	/* Check superblock checksum */
3482 	if (!ext4_superblock_csum_verify(sb, es)) {
3483 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3484 			 "invalid superblock checksum.  Run e2fsck?");
3485 		silent = 1;
3486 		ret = -EFSBADCRC;
3487 		goto cantfind_ext4;
3488 	}
3489 
3490 	/* Precompute checksum seed for all metadata */
3491 	if (ext4_has_feature_csum_seed(sb))
3492 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3493 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3494 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3495 					       sizeof(es->s_uuid));
3496 
3497 	/* Set defaults before we parse the mount options */
3498 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3499 	set_opt(sb, INIT_INODE_TABLE);
3500 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3501 		set_opt(sb, DEBUG);
3502 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3503 		set_opt(sb, GRPID);
3504 	if (def_mount_opts & EXT4_DEFM_UID16)
3505 		set_opt(sb, NO_UID32);
3506 	/* xattr user namespace & acls are now defaulted on */
3507 	set_opt(sb, XATTR_USER);
3508 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3509 	set_opt(sb, POSIX_ACL);
3510 #endif
3511 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3512 	if (ext4_has_metadata_csum(sb))
3513 		set_opt(sb, JOURNAL_CHECKSUM);
3514 
3515 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3516 		set_opt(sb, JOURNAL_DATA);
3517 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3518 		set_opt(sb, ORDERED_DATA);
3519 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3520 		set_opt(sb, WRITEBACK_DATA);
3521 
3522 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3523 		set_opt(sb, ERRORS_PANIC);
3524 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3525 		set_opt(sb, ERRORS_CONT);
3526 	else
3527 		set_opt(sb, ERRORS_RO);
3528 	/* block_validity enabled by default; disable with noblock_validity */
3529 	set_opt(sb, BLOCK_VALIDITY);
3530 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3531 		set_opt(sb, DISCARD);
3532 
3533 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3534 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3535 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3536 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3537 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3538 
3539 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3540 		set_opt(sb, BARRIER);
3541 
3542 	/*
3543 	 * enable delayed allocation by default
3544 	 * Use -o nodelalloc to turn it off
3545 	 */
3546 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3547 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3548 		set_opt(sb, DELALLOC);
3549 
3550 	/*
3551 	 * set default s_li_wait_mult for lazyinit, for the case there is
3552 	 * no mount option specified.
3553 	 */
3554 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3555 
3556 	if (sbi->s_es->s_mount_opts[0]) {
3557 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3558 					      sizeof(sbi->s_es->s_mount_opts),
3559 					      GFP_KERNEL);
3560 		if (!s_mount_opts)
3561 			goto failed_mount;
3562 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3563 				   &journal_ioprio, 0)) {
3564 			ext4_msg(sb, KERN_WARNING,
3565 				 "failed to parse options in superblock: %s",
3566 				 s_mount_opts);
3567 		}
3568 		kfree(s_mount_opts);
3569 	}
3570 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3571 	if (!parse_options((char *) data, sb, &journal_devnum,
3572 			   &journal_ioprio, 0))
3573 		goto failed_mount;
3574 
3575 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3576 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3577 			    "with data=journal disables delayed "
3578 			    "allocation and O_DIRECT support!\n");
3579 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3580 			ext4_msg(sb, KERN_ERR, "can't mount with "
3581 				 "both data=journal and delalloc");
3582 			goto failed_mount;
3583 		}
3584 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3585 			ext4_msg(sb, KERN_ERR, "can't mount with "
3586 				 "both data=journal and dioread_nolock");
3587 			goto failed_mount;
3588 		}
3589 		if (test_opt(sb, DAX)) {
3590 			ext4_msg(sb, KERN_ERR, "can't mount with "
3591 				 "both data=journal and dax");
3592 			goto failed_mount;
3593 		}
3594 		if (ext4_has_feature_encrypt(sb)) {
3595 			ext4_msg(sb, KERN_WARNING,
3596 				 "encrypted files will use data=ordered "
3597 				 "instead of data journaling mode");
3598 		}
3599 		if (test_opt(sb, DELALLOC))
3600 			clear_opt(sb, DELALLOC);
3601 	} else {
3602 		sb->s_iflags |= SB_I_CGROUPWB;
3603 	}
3604 
3605 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3606 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3607 
3608 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3609 	    (ext4_has_compat_features(sb) ||
3610 	     ext4_has_ro_compat_features(sb) ||
3611 	     ext4_has_incompat_features(sb)))
3612 		ext4_msg(sb, KERN_WARNING,
3613 		       "feature flags set on rev 0 fs, "
3614 		       "running e2fsck is recommended");
3615 
3616 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3617 		set_opt2(sb, HURD_COMPAT);
3618 		if (ext4_has_feature_64bit(sb)) {
3619 			ext4_msg(sb, KERN_ERR,
3620 				 "The Hurd can't support 64-bit file systems");
3621 			goto failed_mount;
3622 		}
3623 
3624 		/*
3625 		 * ea_inode feature uses l_i_version field which is not
3626 		 * available in HURD_COMPAT mode.
3627 		 */
3628 		if (ext4_has_feature_ea_inode(sb)) {
3629 			ext4_msg(sb, KERN_ERR,
3630 				 "ea_inode feature is not supported for Hurd");
3631 			goto failed_mount;
3632 		}
3633 	}
3634 
3635 	if (IS_EXT2_SB(sb)) {
3636 		if (ext2_feature_set_ok(sb))
3637 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3638 				 "using the ext4 subsystem");
3639 		else {
3640 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3641 				 "to feature incompatibilities");
3642 			goto failed_mount;
3643 		}
3644 	}
3645 
3646 	if (IS_EXT3_SB(sb)) {
3647 		if (ext3_feature_set_ok(sb))
3648 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3649 				 "using the ext4 subsystem");
3650 		else {
3651 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3652 				 "to feature incompatibilities");
3653 			goto failed_mount;
3654 		}
3655 	}
3656 
3657 	/*
3658 	 * Check feature flags regardless of the revision level, since we
3659 	 * previously didn't change the revision level when setting the flags,
3660 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3661 	 */
3662 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3663 		goto failed_mount;
3664 
3665 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3666 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3667 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3668 		ext4_msg(sb, KERN_ERR,
3669 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3670 			 blocksize, le32_to_cpu(es->s_log_block_size));
3671 		goto failed_mount;
3672 	}
3673 	if (le32_to_cpu(es->s_log_block_size) >
3674 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3675 		ext4_msg(sb, KERN_ERR,
3676 			 "Invalid log block size: %u",
3677 			 le32_to_cpu(es->s_log_block_size));
3678 		goto failed_mount;
3679 	}
3680 
3681 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3682 		ext4_msg(sb, KERN_ERR,
3683 			 "Number of reserved GDT blocks insanely large: %d",
3684 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3685 		goto failed_mount;
3686 	}
3687 
3688 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3689 		err = bdev_dax_supported(sb, blocksize);
3690 		if (err)
3691 			goto failed_mount;
3692 	}
3693 
3694 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3695 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3696 			 es->s_encryption_level);
3697 		goto failed_mount;
3698 	}
3699 
3700 	if (sb->s_blocksize != blocksize) {
3701 		/* Validate the filesystem blocksize */
3702 		if (!sb_set_blocksize(sb, blocksize)) {
3703 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3704 					blocksize);
3705 			goto failed_mount;
3706 		}
3707 
3708 		brelse(bh);
3709 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3710 		offset = do_div(logical_sb_block, blocksize);
3711 		bh = sb_bread_unmovable(sb, logical_sb_block);
3712 		if (!bh) {
3713 			ext4_msg(sb, KERN_ERR,
3714 			       "Can't read superblock on 2nd try");
3715 			goto failed_mount;
3716 		}
3717 		es = (struct ext4_super_block *)(bh->b_data + offset);
3718 		sbi->s_es = es;
3719 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3720 			ext4_msg(sb, KERN_ERR,
3721 			       "Magic mismatch, very weird!");
3722 			goto failed_mount;
3723 		}
3724 	}
3725 
3726 	has_huge_files = ext4_has_feature_huge_file(sb);
3727 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3728 						      has_huge_files);
3729 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3730 
3731 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3732 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3733 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3734 	} else {
3735 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3736 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3737 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3738 		    (!is_power_of_2(sbi->s_inode_size)) ||
3739 		    (sbi->s_inode_size > blocksize)) {
3740 			ext4_msg(sb, KERN_ERR,
3741 			       "unsupported inode size: %d",
3742 			       sbi->s_inode_size);
3743 			goto failed_mount;
3744 		}
3745 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3746 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3747 	}
3748 
3749 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3750 	if (ext4_has_feature_64bit(sb)) {
3751 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3752 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3753 		    !is_power_of_2(sbi->s_desc_size)) {
3754 			ext4_msg(sb, KERN_ERR,
3755 			       "unsupported descriptor size %lu",
3756 			       sbi->s_desc_size);
3757 			goto failed_mount;
3758 		}
3759 	} else
3760 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3761 
3762 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3763 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3764 
3765 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3766 	if (sbi->s_inodes_per_block == 0)
3767 		goto cantfind_ext4;
3768 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3769 	    sbi->s_inodes_per_group > blocksize * 8) {
3770 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3771 			 sbi->s_blocks_per_group);
3772 		goto failed_mount;
3773 	}
3774 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3775 					sbi->s_inodes_per_block;
3776 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3777 	sbi->s_sbh = bh;
3778 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3779 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3780 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3781 
3782 	for (i = 0; i < 4; i++)
3783 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3784 	sbi->s_def_hash_version = es->s_def_hash_version;
3785 	if (ext4_has_feature_dir_index(sb)) {
3786 		i = le32_to_cpu(es->s_flags);
3787 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3788 			sbi->s_hash_unsigned = 3;
3789 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3790 #ifdef __CHAR_UNSIGNED__
3791 			if (!(sb->s_flags & MS_RDONLY))
3792 				es->s_flags |=
3793 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3794 			sbi->s_hash_unsigned = 3;
3795 #else
3796 			if (!(sb->s_flags & MS_RDONLY))
3797 				es->s_flags |=
3798 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3799 #endif
3800 		}
3801 	}
3802 
3803 	/* Handle clustersize */
3804 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3805 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3806 	if (has_bigalloc) {
3807 		if (clustersize < blocksize) {
3808 			ext4_msg(sb, KERN_ERR,
3809 				 "cluster size (%d) smaller than "
3810 				 "block size (%d)", clustersize, blocksize);
3811 			goto failed_mount;
3812 		}
3813 		if (le32_to_cpu(es->s_log_cluster_size) >
3814 		    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3815 			ext4_msg(sb, KERN_ERR,
3816 				 "Invalid log cluster size: %u",
3817 				 le32_to_cpu(es->s_log_cluster_size));
3818 			goto failed_mount;
3819 		}
3820 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3821 			le32_to_cpu(es->s_log_block_size);
3822 		sbi->s_clusters_per_group =
3823 			le32_to_cpu(es->s_clusters_per_group);
3824 		if (sbi->s_clusters_per_group > blocksize * 8) {
3825 			ext4_msg(sb, KERN_ERR,
3826 				 "#clusters per group too big: %lu",
3827 				 sbi->s_clusters_per_group);
3828 			goto failed_mount;
3829 		}
3830 		if (sbi->s_blocks_per_group !=
3831 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3832 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3833 				 "clusters per group (%lu) inconsistent",
3834 				 sbi->s_blocks_per_group,
3835 				 sbi->s_clusters_per_group);
3836 			goto failed_mount;
3837 		}
3838 	} else {
3839 		if (clustersize != blocksize) {
3840 			ext4_warning(sb, "fragment/cluster size (%d) != "
3841 				     "block size (%d)", clustersize,
3842 				     blocksize);
3843 			clustersize = blocksize;
3844 		}
3845 		if (sbi->s_blocks_per_group > blocksize * 8) {
3846 			ext4_msg(sb, KERN_ERR,
3847 				 "#blocks per group too big: %lu",
3848 				 sbi->s_blocks_per_group);
3849 			goto failed_mount;
3850 		}
3851 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3852 		sbi->s_cluster_bits = 0;
3853 	}
3854 	sbi->s_cluster_ratio = clustersize / blocksize;
3855 
3856 	/* Do we have standard group size of clustersize * 8 blocks ? */
3857 	if (sbi->s_blocks_per_group == clustersize << 3)
3858 		set_opt2(sb, STD_GROUP_SIZE);
3859 
3860 	/*
3861 	 * Test whether we have more sectors than will fit in sector_t,
3862 	 * and whether the max offset is addressable by the page cache.
3863 	 */
3864 	err = generic_check_addressable(sb->s_blocksize_bits,
3865 					ext4_blocks_count(es));
3866 	if (err) {
3867 		ext4_msg(sb, KERN_ERR, "filesystem"
3868 			 " too large to mount safely on this system");
3869 		if (sizeof(sector_t) < 8)
3870 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3871 		goto failed_mount;
3872 	}
3873 
3874 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3875 		goto cantfind_ext4;
3876 
3877 	/* check blocks count against device size */
3878 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3879 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3880 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3881 		       "exceeds size of device (%llu blocks)",
3882 		       ext4_blocks_count(es), blocks_count);
3883 		goto failed_mount;
3884 	}
3885 
3886 	/*
3887 	 * It makes no sense for the first data block to be beyond the end
3888 	 * of the filesystem.
3889 	 */
3890 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3891 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3892 			 "block %u is beyond end of filesystem (%llu)",
3893 			 le32_to_cpu(es->s_first_data_block),
3894 			 ext4_blocks_count(es));
3895 		goto failed_mount;
3896 	}
3897 	blocks_count = (ext4_blocks_count(es) -
3898 			le32_to_cpu(es->s_first_data_block) +
3899 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3900 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3901 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3902 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3903 		       "(block count %llu, first data block %u, "
3904 		       "blocks per group %lu)", sbi->s_groups_count,
3905 		       ext4_blocks_count(es),
3906 		       le32_to_cpu(es->s_first_data_block),
3907 		       EXT4_BLOCKS_PER_GROUP(sb));
3908 		goto failed_mount;
3909 	}
3910 	sbi->s_groups_count = blocks_count;
3911 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3912 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3913 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3914 		   EXT4_DESC_PER_BLOCK(sb);
3915 	if (ext4_has_feature_meta_bg(sb)) {
3916 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3917 			ext4_msg(sb, KERN_WARNING,
3918 				 "first meta block group too large: %u "
3919 				 "(group descriptor block count %u)",
3920 				 le32_to_cpu(es->s_first_meta_bg), db_count);
3921 			goto failed_mount;
3922 		}
3923 	}
3924 	sbi->s_group_desc = kvmalloc(db_count *
3925 					  sizeof(struct buffer_head *),
3926 					  GFP_KERNEL);
3927 	if (sbi->s_group_desc == NULL) {
3928 		ext4_msg(sb, KERN_ERR, "not enough memory");
3929 		ret = -ENOMEM;
3930 		goto failed_mount;
3931 	}
3932 
3933 	bgl_lock_init(sbi->s_blockgroup_lock);
3934 
3935 	/* Pre-read the descriptors into the buffer cache */
3936 	for (i = 0; i < db_count; i++) {
3937 		block = descriptor_loc(sb, logical_sb_block, i);
3938 		sb_breadahead(sb, block);
3939 	}
3940 
3941 	for (i = 0; i < db_count; i++) {
3942 		block = descriptor_loc(sb, logical_sb_block, i);
3943 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3944 		if (!sbi->s_group_desc[i]) {
3945 			ext4_msg(sb, KERN_ERR,
3946 			       "can't read group descriptor %d", i);
3947 			db_count = i;
3948 			goto failed_mount2;
3949 		}
3950 	}
3951 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3952 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3953 		ret = -EFSCORRUPTED;
3954 		goto failed_mount2;
3955 	}
3956 
3957 	sbi->s_gdb_count = db_count;
3958 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3959 	spin_lock_init(&sbi->s_next_gen_lock);
3960 
3961 	setup_timer(&sbi->s_err_report, print_daily_error_info,
3962 		(unsigned long) sb);
3963 
3964 	/* Register extent status tree shrinker */
3965 	if (ext4_es_register_shrinker(sbi))
3966 		goto failed_mount3;
3967 
3968 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3969 	sbi->s_extent_max_zeroout_kb = 32;
3970 
3971 	/*
3972 	 * set up enough so that it can read an inode
3973 	 */
3974 	sb->s_op = &ext4_sops;
3975 	sb->s_export_op = &ext4_export_ops;
3976 	sb->s_xattr = ext4_xattr_handlers;
3977 	sb->s_cop = &ext4_cryptops;
3978 #ifdef CONFIG_QUOTA
3979 	sb->dq_op = &ext4_quota_operations;
3980 	if (ext4_has_feature_quota(sb))
3981 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
3982 	else
3983 		sb->s_qcop = &ext4_qctl_operations;
3984 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3985 #endif
3986 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3987 
3988 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3989 	mutex_init(&sbi->s_orphan_lock);
3990 
3991 	sb->s_root = NULL;
3992 
3993 	needs_recovery = (es->s_last_orphan != 0 ||
3994 			  ext4_has_feature_journal_needs_recovery(sb));
3995 
3996 	if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3997 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3998 			goto failed_mount3a;
3999 
4000 	/*
4001 	 * The first inode we look at is the journal inode.  Don't try
4002 	 * root first: it may be modified in the journal!
4003 	 */
4004 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4005 		err = ext4_load_journal(sb, es, journal_devnum);
4006 		if (err)
4007 			goto failed_mount3a;
4008 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
4009 		   ext4_has_feature_journal_needs_recovery(sb)) {
4010 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4011 		       "suppressed and not mounted read-only");
4012 		goto failed_mount_wq;
4013 	} else {
4014 		/* Nojournal mode, all journal mount options are illegal */
4015 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4016 			ext4_msg(sb, KERN_ERR, "can't mount with "
4017 				 "journal_checksum, fs mounted w/o journal");
4018 			goto failed_mount_wq;
4019 		}
4020 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4021 			ext4_msg(sb, KERN_ERR, "can't mount with "
4022 				 "journal_async_commit, fs mounted w/o journal");
4023 			goto failed_mount_wq;
4024 		}
4025 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4026 			ext4_msg(sb, KERN_ERR, "can't mount with "
4027 				 "commit=%lu, fs mounted w/o journal",
4028 				 sbi->s_commit_interval / HZ);
4029 			goto failed_mount_wq;
4030 		}
4031 		if (EXT4_MOUNT_DATA_FLAGS &
4032 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4033 			ext4_msg(sb, KERN_ERR, "can't mount with "
4034 				 "data=, fs mounted w/o journal");
4035 			goto failed_mount_wq;
4036 		}
4037 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4038 		clear_opt(sb, JOURNAL_CHECKSUM);
4039 		clear_opt(sb, DATA_FLAGS);
4040 		sbi->s_journal = NULL;
4041 		needs_recovery = 0;
4042 		goto no_journal;
4043 	}
4044 
4045 	if (ext4_has_feature_64bit(sb) &&
4046 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4047 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4048 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4049 		goto failed_mount_wq;
4050 	}
4051 
4052 	if (!set_journal_csum_feature_set(sb)) {
4053 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4054 			 "feature set");
4055 		goto failed_mount_wq;
4056 	}
4057 
4058 	/* We have now updated the journal if required, so we can
4059 	 * validate the data journaling mode. */
4060 	switch (test_opt(sb, DATA_FLAGS)) {
4061 	case 0:
4062 		/* No mode set, assume a default based on the journal
4063 		 * capabilities: ORDERED_DATA if the journal can
4064 		 * cope, else JOURNAL_DATA
4065 		 */
4066 		if (jbd2_journal_check_available_features
4067 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4068 			set_opt(sb, ORDERED_DATA);
4069 		else
4070 			set_opt(sb, JOURNAL_DATA);
4071 		break;
4072 
4073 	case EXT4_MOUNT_ORDERED_DATA:
4074 	case EXT4_MOUNT_WRITEBACK_DATA:
4075 		if (!jbd2_journal_check_available_features
4076 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4077 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4078 			       "requested data journaling mode");
4079 			goto failed_mount_wq;
4080 		}
4081 	default:
4082 		break;
4083 	}
4084 
4085 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4086 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4087 		ext4_msg(sb, KERN_ERR, "can't mount with "
4088 			"journal_async_commit in data=ordered mode");
4089 		goto failed_mount_wq;
4090 	}
4091 
4092 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4093 
4094 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4095 
4096 no_journal:
4097 	if (!test_opt(sb, NO_MBCACHE)) {
4098 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4099 		if (!sbi->s_ea_block_cache) {
4100 			ext4_msg(sb, KERN_ERR,
4101 				 "Failed to create ea_block_cache");
4102 			goto failed_mount_wq;
4103 		}
4104 
4105 		if (ext4_has_feature_ea_inode(sb)) {
4106 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4107 			if (!sbi->s_ea_inode_cache) {
4108 				ext4_msg(sb, KERN_ERR,
4109 					 "Failed to create ea_inode_cache");
4110 				goto failed_mount_wq;
4111 			}
4112 		}
4113 	}
4114 
4115 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4116 	    (blocksize != PAGE_SIZE)) {
4117 		ext4_msg(sb, KERN_ERR,
4118 			 "Unsupported blocksize for fs encryption");
4119 		goto failed_mount_wq;
4120 	}
4121 
4122 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
4123 	    !ext4_has_feature_encrypt(sb)) {
4124 		ext4_set_feature_encrypt(sb);
4125 		ext4_commit_super(sb, 1);
4126 	}
4127 
4128 	/*
4129 	 * Get the # of file system overhead blocks from the
4130 	 * superblock if present.
4131 	 */
4132 	if (es->s_overhead_clusters)
4133 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4134 	else {
4135 		err = ext4_calculate_overhead(sb);
4136 		if (err)
4137 			goto failed_mount_wq;
4138 	}
4139 
4140 	/*
4141 	 * The maximum number of concurrent works can be high and
4142 	 * concurrency isn't really necessary.  Limit it to 1.
4143 	 */
4144 	EXT4_SB(sb)->rsv_conversion_wq =
4145 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4146 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4147 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4148 		ret = -ENOMEM;
4149 		goto failed_mount4;
4150 	}
4151 
4152 	/*
4153 	 * The jbd2_journal_load will have done any necessary log recovery,
4154 	 * so we can safely mount the rest of the filesystem now.
4155 	 */
4156 
4157 	root = ext4_iget(sb, EXT4_ROOT_INO);
4158 	if (IS_ERR(root)) {
4159 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4160 		ret = PTR_ERR(root);
4161 		root = NULL;
4162 		goto failed_mount4;
4163 	}
4164 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4165 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4166 		iput(root);
4167 		goto failed_mount4;
4168 	}
4169 	sb->s_root = d_make_root(root);
4170 	if (!sb->s_root) {
4171 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4172 		ret = -ENOMEM;
4173 		goto failed_mount4;
4174 	}
4175 
4176 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4177 		sb->s_flags |= MS_RDONLY;
4178 
4179 	/* determine the minimum size of new large inodes, if present */
4180 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4181 	    sbi->s_want_extra_isize == 0) {
4182 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4183 						     EXT4_GOOD_OLD_INODE_SIZE;
4184 		if (ext4_has_feature_extra_isize(sb)) {
4185 			if (sbi->s_want_extra_isize <
4186 			    le16_to_cpu(es->s_want_extra_isize))
4187 				sbi->s_want_extra_isize =
4188 					le16_to_cpu(es->s_want_extra_isize);
4189 			if (sbi->s_want_extra_isize <
4190 			    le16_to_cpu(es->s_min_extra_isize))
4191 				sbi->s_want_extra_isize =
4192 					le16_to_cpu(es->s_min_extra_isize);
4193 		}
4194 	}
4195 	/* Check if enough inode space is available */
4196 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4197 							sbi->s_inode_size) {
4198 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4199 						       EXT4_GOOD_OLD_INODE_SIZE;
4200 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4201 			 "available");
4202 	}
4203 
4204 	ext4_set_resv_clusters(sb);
4205 
4206 	err = ext4_setup_system_zone(sb);
4207 	if (err) {
4208 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4209 			 "zone (%d)", err);
4210 		goto failed_mount4a;
4211 	}
4212 
4213 	ext4_ext_init(sb);
4214 	err = ext4_mb_init(sb);
4215 	if (err) {
4216 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4217 			 err);
4218 		goto failed_mount5;
4219 	}
4220 
4221 	block = ext4_count_free_clusters(sb);
4222 	ext4_free_blocks_count_set(sbi->s_es,
4223 				   EXT4_C2B(sbi, block));
4224 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4225 				  GFP_KERNEL);
4226 	if (!err) {
4227 		unsigned long freei = ext4_count_free_inodes(sb);
4228 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4229 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4230 					  GFP_KERNEL);
4231 	}
4232 	if (!err)
4233 		err = percpu_counter_init(&sbi->s_dirs_counter,
4234 					  ext4_count_dirs(sb), GFP_KERNEL);
4235 	if (!err)
4236 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4237 					  GFP_KERNEL);
4238 	if (!err)
4239 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4240 
4241 	if (err) {
4242 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4243 		goto failed_mount6;
4244 	}
4245 
4246 	if (ext4_has_feature_flex_bg(sb))
4247 		if (!ext4_fill_flex_info(sb)) {
4248 			ext4_msg(sb, KERN_ERR,
4249 			       "unable to initialize "
4250 			       "flex_bg meta info!");
4251 			goto failed_mount6;
4252 		}
4253 
4254 	err = ext4_register_li_request(sb, first_not_zeroed);
4255 	if (err)
4256 		goto failed_mount6;
4257 
4258 	err = ext4_register_sysfs(sb);
4259 	if (err)
4260 		goto failed_mount7;
4261 
4262 #ifdef CONFIG_QUOTA
4263 	/* Enable quota usage during mount. */
4264 	if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4265 		err = ext4_enable_quotas(sb);
4266 		if (err)
4267 			goto failed_mount8;
4268 	}
4269 #endif  /* CONFIG_QUOTA */
4270 
4271 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4272 	ext4_orphan_cleanup(sb, es);
4273 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4274 	if (needs_recovery) {
4275 		ext4_msg(sb, KERN_INFO, "recovery complete");
4276 		ext4_mark_recovery_complete(sb, es);
4277 	}
4278 	if (EXT4_SB(sb)->s_journal) {
4279 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4280 			descr = " journalled data mode";
4281 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4282 			descr = " ordered data mode";
4283 		else
4284 			descr = " writeback data mode";
4285 	} else
4286 		descr = "out journal";
4287 
4288 	if (test_opt(sb, DISCARD)) {
4289 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4290 		if (!blk_queue_discard(q))
4291 			ext4_msg(sb, KERN_WARNING,
4292 				 "mounting with \"discard\" option, but "
4293 				 "the device does not support discard");
4294 	}
4295 
4296 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4297 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4298 			 "Opts: %.*s%s%s", descr,
4299 			 (int) sizeof(sbi->s_es->s_mount_opts),
4300 			 sbi->s_es->s_mount_opts,
4301 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4302 
4303 	if (es->s_error_count)
4304 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4305 
4306 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4307 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4308 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4309 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4310 
4311 	kfree(orig_data);
4312 	return 0;
4313 
4314 cantfind_ext4:
4315 	if (!silent)
4316 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4317 	goto failed_mount;
4318 
4319 #ifdef CONFIG_QUOTA
4320 failed_mount8:
4321 	ext4_unregister_sysfs(sb);
4322 #endif
4323 failed_mount7:
4324 	ext4_unregister_li_request(sb);
4325 failed_mount6:
4326 	ext4_mb_release(sb);
4327 	if (sbi->s_flex_groups)
4328 		kvfree(sbi->s_flex_groups);
4329 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4330 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4331 	percpu_counter_destroy(&sbi->s_dirs_counter);
4332 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4333 failed_mount5:
4334 	ext4_ext_release(sb);
4335 	ext4_release_system_zone(sb);
4336 failed_mount4a:
4337 	dput(sb->s_root);
4338 	sb->s_root = NULL;
4339 failed_mount4:
4340 	ext4_msg(sb, KERN_ERR, "mount failed");
4341 	if (EXT4_SB(sb)->rsv_conversion_wq)
4342 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4343 failed_mount_wq:
4344 	if (sbi->s_ea_inode_cache) {
4345 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4346 		sbi->s_ea_inode_cache = NULL;
4347 	}
4348 	if (sbi->s_ea_block_cache) {
4349 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4350 		sbi->s_ea_block_cache = NULL;
4351 	}
4352 	if (sbi->s_journal) {
4353 		jbd2_journal_destroy(sbi->s_journal);
4354 		sbi->s_journal = NULL;
4355 	}
4356 failed_mount3a:
4357 	ext4_es_unregister_shrinker(sbi);
4358 failed_mount3:
4359 	del_timer_sync(&sbi->s_err_report);
4360 	if (sbi->s_mmp_tsk)
4361 		kthread_stop(sbi->s_mmp_tsk);
4362 failed_mount2:
4363 	for (i = 0; i < db_count; i++)
4364 		brelse(sbi->s_group_desc[i]);
4365 	kvfree(sbi->s_group_desc);
4366 failed_mount:
4367 	if (sbi->s_chksum_driver)
4368 		crypto_free_shash(sbi->s_chksum_driver);
4369 #ifdef CONFIG_QUOTA
4370 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4371 		kfree(sbi->s_qf_names[i]);
4372 #endif
4373 	ext4_blkdev_remove(sbi);
4374 	brelse(bh);
4375 out_fail:
4376 	sb->s_fs_info = NULL;
4377 	kfree(sbi->s_blockgroup_lock);
4378 out_free_base:
4379 	kfree(sbi);
4380 	kfree(orig_data);
4381 	return err ? err : ret;
4382 }
4383 
4384 /*
4385  * Setup any per-fs journal parameters now.  We'll do this both on
4386  * initial mount, once the journal has been initialised but before we've
4387  * done any recovery; and again on any subsequent remount.
4388  */
4389 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4390 {
4391 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4392 
4393 	journal->j_commit_interval = sbi->s_commit_interval;
4394 	journal->j_min_batch_time = sbi->s_min_batch_time;
4395 	journal->j_max_batch_time = sbi->s_max_batch_time;
4396 
4397 	write_lock(&journal->j_state_lock);
4398 	if (test_opt(sb, BARRIER))
4399 		journal->j_flags |= JBD2_BARRIER;
4400 	else
4401 		journal->j_flags &= ~JBD2_BARRIER;
4402 	if (test_opt(sb, DATA_ERR_ABORT))
4403 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4404 	else
4405 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4406 	write_unlock(&journal->j_state_lock);
4407 }
4408 
4409 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4410 					     unsigned int journal_inum)
4411 {
4412 	struct inode *journal_inode;
4413 
4414 	/*
4415 	 * Test for the existence of a valid inode on disk.  Bad things
4416 	 * happen if we iget() an unused inode, as the subsequent iput()
4417 	 * will try to delete it.
4418 	 */
4419 	journal_inode = ext4_iget(sb, journal_inum);
4420 	if (IS_ERR(journal_inode)) {
4421 		ext4_msg(sb, KERN_ERR, "no journal found");
4422 		return NULL;
4423 	}
4424 	if (!journal_inode->i_nlink) {
4425 		make_bad_inode(journal_inode);
4426 		iput(journal_inode);
4427 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4428 		return NULL;
4429 	}
4430 
4431 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4432 		  journal_inode, journal_inode->i_size);
4433 	if (!S_ISREG(journal_inode->i_mode)) {
4434 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4435 		iput(journal_inode);
4436 		return NULL;
4437 	}
4438 	return journal_inode;
4439 }
4440 
4441 static journal_t *ext4_get_journal(struct super_block *sb,
4442 				   unsigned int journal_inum)
4443 {
4444 	struct inode *journal_inode;
4445 	journal_t *journal;
4446 
4447 	BUG_ON(!ext4_has_feature_journal(sb));
4448 
4449 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4450 	if (!journal_inode)
4451 		return NULL;
4452 
4453 	journal = jbd2_journal_init_inode(journal_inode);
4454 	if (!journal) {
4455 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4456 		iput(journal_inode);
4457 		return NULL;
4458 	}
4459 	journal->j_private = sb;
4460 	ext4_init_journal_params(sb, journal);
4461 	return journal;
4462 }
4463 
4464 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4465 				       dev_t j_dev)
4466 {
4467 	struct buffer_head *bh;
4468 	journal_t *journal;
4469 	ext4_fsblk_t start;
4470 	ext4_fsblk_t len;
4471 	int hblock, blocksize;
4472 	ext4_fsblk_t sb_block;
4473 	unsigned long offset;
4474 	struct ext4_super_block *es;
4475 	struct block_device *bdev;
4476 
4477 	BUG_ON(!ext4_has_feature_journal(sb));
4478 
4479 	bdev = ext4_blkdev_get(j_dev, sb);
4480 	if (bdev == NULL)
4481 		return NULL;
4482 
4483 	blocksize = sb->s_blocksize;
4484 	hblock = bdev_logical_block_size(bdev);
4485 	if (blocksize < hblock) {
4486 		ext4_msg(sb, KERN_ERR,
4487 			"blocksize too small for journal device");
4488 		goto out_bdev;
4489 	}
4490 
4491 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4492 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4493 	set_blocksize(bdev, blocksize);
4494 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4495 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4496 		       "external journal");
4497 		goto out_bdev;
4498 	}
4499 
4500 	es = (struct ext4_super_block *) (bh->b_data + offset);
4501 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4502 	    !(le32_to_cpu(es->s_feature_incompat) &
4503 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4504 		ext4_msg(sb, KERN_ERR, "external journal has "
4505 					"bad superblock");
4506 		brelse(bh);
4507 		goto out_bdev;
4508 	}
4509 
4510 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4511 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4512 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4513 		ext4_msg(sb, KERN_ERR, "external journal has "
4514 				       "corrupt superblock");
4515 		brelse(bh);
4516 		goto out_bdev;
4517 	}
4518 
4519 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4520 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4521 		brelse(bh);
4522 		goto out_bdev;
4523 	}
4524 
4525 	len = ext4_blocks_count(es);
4526 	start = sb_block + 1;
4527 	brelse(bh);	/* we're done with the superblock */
4528 
4529 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4530 					start, len, blocksize);
4531 	if (!journal) {
4532 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4533 		goto out_bdev;
4534 	}
4535 	journal->j_private = sb;
4536 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4537 	wait_on_buffer(journal->j_sb_buffer);
4538 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4539 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4540 		goto out_journal;
4541 	}
4542 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4543 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4544 					"user (unsupported) - %d",
4545 			be32_to_cpu(journal->j_superblock->s_nr_users));
4546 		goto out_journal;
4547 	}
4548 	EXT4_SB(sb)->journal_bdev = bdev;
4549 	ext4_init_journal_params(sb, journal);
4550 	return journal;
4551 
4552 out_journal:
4553 	jbd2_journal_destroy(journal);
4554 out_bdev:
4555 	ext4_blkdev_put(bdev);
4556 	return NULL;
4557 }
4558 
4559 static int ext4_load_journal(struct super_block *sb,
4560 			     struct ext4_super_block *es,
4561 			     unsigned long journal_devnum)
4562 {
4563 	journal_t *journal;
4564 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4565 	dev_t journal_dev;
4566 	int err = 0;
4567 	int really_read_only;
4568 
4569 	BUG_ON(!ext4_has_feature_journal(sb));
4570 
4571 	if (journal_devnum &&
4572 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4573 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4574 			"numbers have changed");
4575 		journal_dev = new_decode_dev(journal_devnum);
4576 	} else
4577 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4578 
4579 	really_read_only = bdev_read_only(sb->s_bdev);
4580 
4581 	/*
4582 	 * Are we loading a blank journal or performing recovery after a
4583 	 * crash?  For recovery, we need to check in advance whether we
4584 	 * can get read-write access to the device.
4585 	 */
4586 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4587 		if (sb->s_flags & MS_RDONLY) {
4588 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4589 					"required on readonly filesystem");
4590 			if (really_read_only) {
4591 				ext4_msg(sb, KERN_ERR, "write access "
4592 					"unavailable, cannot proceed");
4593 				return -EROFS;
4594 			}
4595 			ext4_msg(sb, KERN_INFO, "write access will "
4596 			       "be enabled during recovery");
4597 		}
4598 	}
4599 
4600 	if (journal_inum && journal_dev) {
4601 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4602 		       "and inode journals!");
4603 		return -EINVAL;
4604 	}
4605 
4606 	if (journal_inum) {
4607 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4608 			return -EINVAL;
4609 	} else {
4610 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4611 			return -EINVAL;
4612 	}
4613 
4614 	if (!(journal->j_flags & JBD2_BARRIER))
4615 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4616 
4617 	if (!ext4_has_feature_journal_needs_recovery(sb))
4618 		err = jbd2_journal_wipe(journal, !really_read_only);
4619 	if (!err) {
4620 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4621 		if (save)
4622 			memcpy(save, ((char *) es) +
4623 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4624 		err = jbd2_journal_load(journal);
4625 		if (save)
4626 			memcpy(((char *) es) + EXT4_S_ERR_START,
4627 			       save, EXT4_S_ERR_LEN);
4628 		kfree(save);
4629 	}
4630 
4631 	if (err) {
4632 		ext4_msg(sb, KERN_ERR, "error loading journal");
4633 		jbd2_journal_destroy(journal);
4634 		return err;
4635 	}
4636 
4637 	EXT4_SB(sb)->s_journal = journal;
4638 	ext4_clear_journal_err(sb, es);
4639 
4640 	if (!really_read_only && journal_devnum &&
4641 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4642 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4643 
4644 		/* Make sure we flush the recovery flag to disk. */
4645 		ext4_commit_super(sb, 1);
4646 	}
4647 
4648 	return 0;
4649 }
4650 
4651 static int ext4_commit_super(struct super_block *sb, int sync)
4652 {
4653 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4654 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4655 	int error = 0;
4656 
4657 	if (!sbh || block_device_ejected(sb))
4658 		return error;
4659 	/*
4660 	 * If the file system is mounted read-only, don't update the
4661 	 * superblock write time.  This avoids updating the superblock
4662 	 * write time when we are mounting the root file system
4663 	 * read/only but we need to replay the journal; at that point,
4664 	 * for people who are east of GMT and who make their clock
4665 	 * tick in localtime for Windows bug-for-bug compatibility,
4666 	 * the clock is set in the future, and this will cause e2fsck
4667 	 * to complain and force a full file system check.
4668 	 */
4669 	if (!(sb->s_flags & MS_RDONLY))
4670 		es->s_wtime = cpu_to_le32(get_seconds());
4671 	if (sb->s_bdev->bd_part)
4672 		es->s_kbytes_written =
4673 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4674 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4675 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4676 	else
4677 		es->s_kbytes_written =
4678 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4679 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4680 		ext4_free_blocks_count_set(es,
4681 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4682 				&EXT4_SB(sb)->s_freeclusters_counter)));
4683 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4684 		es->s_free_inodes_count =
4685 			cpu_to_le32(percpu_counter_sum_positive(
4686 				&EXT4_SB(sb)->s_freeinodes_counter));
4687 	BUFFER_TRACE(sbh, "marking dirty");
4688 	ext4_superblock_csum_set(sb);
4689 	if (sync)
4690 		lock_buffer(sbh);
4691 	if (buffer_write_io_error(sbh)) {
4692 		/*
4693 		 * Oh, dear.  A previous attempt to write the
4694 		 * superblock failed.  This could happen because the
4695 		 * USB device was yanked out.  Or it could happen to
4696 		 * be a transient write error and maybe the block will
4697 		 * be remapped.  Nothing we can do but to retry the
4698 		 * write and hope for the best.
4699 		 */
4700 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4701 		       "superblock detected");
4702 		clear_buffer_write_io_error(sbh);
4703 		set_buffer_uptodate(sbh);
4704 	}
4705 	mark_buffer_dirty(sbh);
4706 	if (sync) {
4707 		unlock_buffer(sbh);
4708 		error = __sync_dirty_buffer(sbh,
4709 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4710 		if (error)
4711 			return error;
4712 
4713 		error = buffer_write_io_error(sbh);
4714 		if (error) {
4715 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4716 			       "superblock");
4717 			clear_buffer_write_io_error(sbh);
4718 			set_buffer_uptodate(sbh);
4719 		}
4720 	}
4721 	return error;
4722 }
4723 
4724 /*
4725  * Have we just finished recovery?  If so, and if we are mounting (or
4726  * remounting) the filesystem readonly, then we will end up with a
4727  * consistent fs on disk.  Record that fact.
4728  */
4729 static void ext4_mark_recovery_complete(struct super_block *sb,
4730 					struct ext4_super_block *es)
4731 {
4732 	journal_t *journal = EXT4_SB(sb)->s_journal;
4733 
4734 	if (!ext4_has_feature_journal(sb)) {
4735 		BUG_ON(journal != NULL);
4736 		return;
4737 	}
4738 	jbd2_journal_lock_updates(journal);
4739 	if (jbd2_journal_flush(journal) < 0)
4740 		goto out;
4741 
4742 	if (ext4_has_feature_journal_needs_recovery(sb) &&
4743 	    sb->s_flags & MS_RDONLY) {
4744 		ext4_clear_feature_journal_needs_recovery(sb);
4745 		ext4_commit_super(sb, 1);
4746 	}
4747 
4748 out:
4749 	jbd2_journal_unlock_updates(journal);
4750 }
4751 
4752 /*
4753  * If we are mounting (or read-write remounting) a filesystem whose journal
4754  * has recorded an error from a previous lifetime, move that error to the
4755  * main filesystem now.
4756  */
4757 static void ext4_clear_journal_err(struct super_block *sb,
4758 				   struct ext4_super_block *es)
4759 {
4760 	journal_t *journal;
4761 	int j_errno;
4762 	const char *errstr;
4763 
4764 	BUG_ON(!ext4_has_feature_journal(sb));
4765 
4766 	journal = EXT4_SB(sb)->s_journal;
4767 
4768 	/*
4769 	 * Now check for any error status which may have been recorded in the
4770 	 * journal by a prior ext4_error() or ext4_abort()
4771 	 */
4772 
4773 	j_errno = jbd2_journal_errno(journal);
4774 	if (j_errno) {
4775 		char nbuf[16];
4776 
4777 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4778 		ext4_warning(sb, "Filesystem error recorded "
4779 			     "from previous mount: %s", errstr);
4780 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4781 
4782 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4783 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4784 		ext4_commit_super(sb, 1);
4785 
4786 		jbd2_journal_clear_err(journal);
4787 		jbd2_journal_update_sb_errno(journal);
4788 	}
4789 }
4790 
4791 /*
4792  * Force the running and committing transactions to commit,
4793  * and wait on the commit.
4794  */
4795 int ext4_force_commit(struct super_block *sb)
4796 {
4797 	journal_t *journal;
4798 
4799 	if (sb->s_flags & MS_RDONLY)
4800 		return 0;
4801 
4802 	journal = EXT4_SB(sb)->s_journal;
4803 	return ext4_journal_force_commit(journal);
4804 }
4805 
4806 static int ext4_sync_fs(struct super_block *sb, int wait)
4807 {
4808 	int ret = 0;
4809 	tid_t target;
4810 	bool needs_barrier = false;
4811 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4812 
4813 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
4814 		return 0;
4815 
4816 	trace_ext4_sync_fs(sb, wait);
4817 	flush_workqueue(sbi->rsv_conversion_wq);
4818 	/*
4819 	 * Writeback quota in non-journalled quota case - journalled quota has
4820 	 * no dirty dquots
4821 	 */
4822 	dquot_writeback_dquots(sb, -1);
4823 	/*
4824 	 * Data writeback is possible w/o journal transaction, so barrier must
4825 	 * being sent at the end of the function. But we can skip it if
4826 	 * transaction_commit will do it for us.
4827 	 */
4828 	if (sbi->s_journal) {
4829 		target = jbd2_get_latest_transaction(sbi->s_journal);
4830 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4831 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4832 			needs_barrier = true;
4833 
4834 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4835 			if (wait)
4836 				ret = jbd2_log_wait_commit(sbi->s_journal,
4837 							   target);
4838 		}
4839 	} else if (wait && test_opt(sb, BARRIER))
4840 		needs_barrier = true;
4841 	if (needs_barrier) {
4842 		int err;
4843 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4844 		if (!ret)
4845 			ret = err;
4846 	}
4847 
4848 	return ret;
4849 }
4850 
4851 /*
4852  * LVM calls this function before a (read-only) snapshot is created.  This
4853  * gives us a chance to flush the journal completely and mark the fs clean.
4854  *
4855  * Note that only this function cannot bring a filesystem to be in a clean
4856  * state independently. It relies on upper layer to stop all data & metadata
4857  * modifications.
4858  */
4859 static int ext4_freeze(struct super_block *sb)
4860 {
4861 	int error = 0;
4862 	journal_t *journal;
4863 
4864 	if (sb->s_flags & MS_RDONLY)
4865 		return 0;
4866 
4867 	journal = EXT4_SB(sb)->s_journal;
4868 
4869 	if (journal) {
4870 		/* Now we set up the journal barrier. */
4871 		jbd2_journal_lock_updates(journal);
4872 
4873 		/*
4874 		 * Don't clear the needs_recovery flag if we failed to
4875 		 * flush the journal.
4876 		 */
4877 		error = jbd2_journal_flush(journal);
4878 		if (error < 0)
4879 			goto out;
4880 
4881 		/* Journal blocked and flushed, clear needs_recovery flag. */
4882 		ext4_clear_feature_journal_needs_recovery(sb);
4883 	}
4884 
4885 	error = ext4_commit_super(sb, 1);
4886 out:
4887 	if (journal)
4888 		/* we rely on upper layer to stop further updates */
4889 		jbd2_journal_unlock_updates(journal);
4890 	return error;
4891 }
4892 
4893 /*
4894  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4895  * flag here, even though the filesystem is not technically dirty yet.
4896  */
4897 static int ext4_unfreeze(struct super_block *sb)
4898 {
4899 	if ((sb->s_flags & MS_RDONLY) || ext4_forced_shutdown(EXT4_SB(sb)))
4900 		return 0;
4901 
4902 	if (EXT4_SB(sb)->s_journal) {
4903 		/* Reset the needs_recovery flag before the fs is unlocked. */
4904 		ext4_set_feature_journal_needs_recovery(sb);
4905 	}
4906 
4907 	ext4_commit_super(sb, 1);
4908 	return 0;
4909 }
4910 
4911 /*
4912  * Structure to save mount options for ext4_remount's benefit
4913  */
4914 struct ext4_mount_options {
4915 	unsigned long s_mount_opt;
4916 	unsigned long s_mount_opt2;
4917 	kuid_t s_resuid;
4918 	kgid_t s_resgid;
4919 	unsigned long s_commit_interval;
4920 	u32 s_min_batch_time, s_max_batch_time;
4921 #ifdef CONFIG_QUOTA
4922 	int s_jquota_fmt;
4923 	char *s_qf_names[EXT4_MAXQUOTAS];
4924 #endif
4925 };
4926 
4927 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4928 {
4929 	struct ext4_super_block *es;
4930 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4931 	unsigned long old_sb_flags;
4932 	struct ext4_mount_options old_opts;
4933 	int enable_quota = 0;
4934 	ext4_group_t g;
4935 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4936 	int err = 0;
4937 #ifdef CONFIG_QUOTA
4938 	int i, j;
4939 #endif
4940 	char *orig_data = kstrdup(data, GFP_KERNEL);
4941 
4942 	/* Store the original options */
4943 	old_sb_flags = sb->s_flags;
4944 	old_opts.s_mount_opt = sbi->s_mount_opt;
4945 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4946 	old_opts.s_resuid = sbi->s_resuid;
4947 	old_opts.s_resgid = sbi->s_resgid;
4948 	old_opts.s_commit_interval = sbi->s_commit_interval;
4949 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4950 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4951 #ifdef CONFIG_QUOTA
4952 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4953 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4954 		if (sbi->s_qf_names[i]) {
4955 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4956 							 GFP_KERNEL);
4957 			if (!old_opts.s_qf_names[i]) {
4958 				for (j = 0; j < i; j++)
4959 					kfree(old_opts.s_qf_names[j]);
4960 				kfree(orig_data);
4961 				return -ENOMEM;
4962 			}
4963 		} else
4964 			old_opts.s_qf_names[i] = NULL;
4965 #endif
4966 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4967 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4968 
4969 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4970 		err = -EINVAL;
4971 		goto restore_opts;
4972 	}
4973 
4974 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4975 	    test_opt(sb, JOURNAL_CHECKSUM)) {
4976 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4977 			 "during remount not supported; ignoring");
4978 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4979 	}
4980 
4981 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4982 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4983 			ext4_msg(sb, KERN_ERR, "can't mount with "
4984 				 "both data=journal and delalloc");
4985 			err = -EINVAL;
4986 			goto restore_opts;
4987 		}
4988 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4989 			ext4_msg(sb, KERN_ERR, "can't mount with "
4990 				 "both data=journal and dioread_nolock");
4991 			err = -EINVAL;
4992 			goto restore_opts;
4993 		}
4994 		if (test_opt(sb, DAX)) {
4995 			ext4_msg(sb, KERN_ERR, "can't mount with "
4996 				 "both data=journal and dax");
4997 			err = -EINVAL;
4998 			goto restore_opts;
4999 		}
5000 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5001 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5002 			ext4_msg(sb, KERN_ERR, "can't mount with "
5003 				"journal_async_commit in data=ordered mode");
5004 			err = -EINVAL;
5005 			goto restore_opts;
5006 		}
5007 	}
5008 
5009 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5010 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5011 		err = -EINVAL;
5012 		goto restore_opts;
5013 	}
5014 
5015 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5016 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5017 			"dax flag with busy inodes while remounting");
5018 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5019 	}
5020 
5021 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5022 		ext4_abort(sb, "Abort forced by user");
5023 
5024 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
5025 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
5026 
5027 	es = sbi->s_es;
5028 
5029 	if (sbi->s_journal) {
5030 		ext4_init_journal_params(sb, sbi->s_journal);
5031 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5032 	}
5033 
5034 	if (*flags & MS_LAZYTIME)
5035 		sb->s_flags |= MS_LAZYTIME;
5036 
5037 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
5038 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5039 			err = -EROFS;
5040 			goto restore_opts;
5041 		}
5042 
5043 		if (*flags & MS_RDONLY) {
5044 			err = sync_filesystem(sb);
5045 			if (err < 0)
5046 				goto restore_opts;
5047 			err = dquot_suspend(sb, -1);
5048 			if (err < 0)
5049 				goto restore_opts;
5050 
5051 			/*
5052 			 * First of all, the unconditional stuff we have to do
5053 			 * to disable replay of the journal when we next remount
5054 			 */
5055 			sb->s_flags |= MS_RDONLY;
5056 
5057 			/*
5058 			 * OK, test if we are remounting a valid rw partition
5059 			 * readonly, and if so set the rdonly flag and then
5060 			 * mark the partition as valid again.
5061 			 */
5062 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5063 			    (sbi->s_mount_state & EXT4_VALID_FS))
5064 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5065 
5066 			if (sbi->s_journal)
5067 				ext4_mark_recovery_complete(sb, es);
5068 		} else {
5069 			/* Make sure we can mount this feature set readwrite */
5070 			if (ext4_has_feature_readonly(sb) ||
5071 			    !ext4_feature_set_ok(sb, 0)) {
5072 				err = -EROFS;
5073 				goto restore_opts;
5074 			}
5075 			/*
5076 			 * Make sure the group descriptor checksums
5077 			 * are sane.  If they aren't, refuse to remount r/w.
5078 			 */
5079 			for (g = 0; g < sbi->s_groups_count; g++) {
5080 				struct ext4_group_desc *gdp =
5081 					ext4_get_group_desc(sb, g, NULL);
5082 
5083 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5084 					ext4_msg(sb, KERN_ERR,
5085 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5086 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5087 					       le16_to_cpu(gdp->bg_checksum));
5088 					err = -EFSBADCRC;
5089 					goto restore_opts;
5090 				}
5091 			}
5092 
5093 			/*
5094 			 * If we have an unprocessed orphan list hanging
5095 			 * around from a previously readonly bdev mount,
5096 			 * require a full umount/remount for now.
5097 			 */
5098 			if (es->s_last_orphan) {
5099 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5100 				       "remount RDWR because of unprocessed "
5101 				       "orphan inode list.  Please "
5102 				       "umount/remount instead");
5103 				err = -EINVAL;
5104 				goto restore_opts;
5105 			}
5106 
5107 			/*
5108 			 * Mounting a RDONLY partition read-write, so reread
5109 			 * and store the current valid flag.  (It may have
5110 			 * been changed by e2fsck since we originally mounted
5111 			 * the partition.)
5112 			 */
5113 			if (sbi->s_journal)
5114 				ext4_clear_journal_err(sb, es);
5115 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5116 			if (!ext4_setup_super(sb, es, 0))
5117 				sb->s_flags &= ~MS_RDONLY;
5118 			if (ext4_has_feature_mmp(sb))
5119 				if (ext4_multi_mount_protect(sb,
5120 						le64_to_cpu(es->s_mmp_block))) {
5121 					err = -EROFS;
5122 					goto restore_opts;
5123 				}
5124 			enable_quota = 1;
5125 		}
5126 	}
5127 
5128 	/*
5129 	 * Reinitialize lazy itable initialization thread based on
5130 	 * current settings
5131 	 */
5132 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5133 		ext4_unregister_li_request(sb);
5134 	else {
5135 		ext4_group_t first_not_zeroed;
5136 		first_not_zeroed = ext4_has_uninit_itable(sb);
5137 		ext4_register_li_request(sb, first_not_zeroed);
5138 	}
5139 
5140 	ext4_setup_system_zone(sb);
5141 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5142 		ext4_commit_super(sb, 1);
5143 
5144 #ifdef CONFIG_QUOTA
5145 	/* Release old quota file names */
5146 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5147 		kfree(old_opts.s_qf_names[i]);
5148 	if (enable_quota) {
5149 		if (sb_any_quota_suspended(sb))
5150 			dquot_resume(sb, -1);
5151 		else if (ext4_has_feature_quota(sb)) {
5152 			err = ext4_enable_quotas(sb);
5153 			if (err)
5154 				goto restore_opts;
5155 		}
5156 	}
5157 #endif
5158 
5159 	*flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5160 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5161 	kfree(orig_data);
5162 	return 0;
5163 
5164 restore_opts:
5165 	sb->s_flags = old_sb_flags;
5166 	sbi->s_mount_opt = old_opts.s_mount_opt;
5167 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5168 	sbi->s_resuid = old_opts.s_resuid;
5169 	sbi->s_resgid = old_opts.s_resgid;
5170 	sbi->s_commit_interval = old_opts.s_commit_interval;
5171 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5172 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5173 #ifdef CONFIG_QUOTA
5174 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5175 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5176 		kfree(sbi->s_qf_names[i]);
5177 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5178 	}
5179 #endif
5180 	kfree(orig_data);
5181 	return err;
5182 }
5183 
5184 #ifdef CONFIG_QUOTA
5185 static int ext4_statfs_project(struct super_block *sb,
5186 			       kprojid_t projid, struct kstatfs *buf)
5187 {
5188 	struct kqid qid;
5189 	struct dquot *dquot;
5190 	u64 limit;
5191 	u64 curblock;
5192 
5193 	qid = make_kqid_projid(projid);
5194 	dquot = dqget(sb, qid);
5195 	if (IS_ERR(dquot))
5196 		return PTR_ERR(dquot);
5197 	spin_lock(&dq_data_lock);
5198 
5199 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5200 		 dquot->dq_dqb.dqb_bsoftlimit :
5201 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5202 	if (limit && buf->f_blocks > limit) {
5203 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5204 		buf->f_blocks = limit;
5205 		buf->f_bfree = buf->f_bavail =
5206 			(buf->f_blocks > curblock) ?
5207 			 (buf->f_blocks - curblock) : 0;
5208 	}
5209 
5210 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5211 		dquot->dq_dqb.dqb_isoftlimit :
5212 		dquot->dq_dqb.dqb_ihardlimit;
5213 	if (limit && buf->f_files > limit) {
5214 		buf->f_files = limit;
5215 		buf->f_ffree =
5216 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5217 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5218 	}
5219 
5220 	spin_unlock(&dq_data_lock);
5221 	dqput(dquot);
5222 	return 0;
5223 }
5224 #endif
5225 
5226 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5227 {
5228 	struct super_block *sb = dentry->d_sb;
5229 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5230 	struct ext4_super_block *es = sbi->s_es;
5231 	ext4_fsblk_t overhead = 0, resv_blocks;
5232 	u64 fsid;
5233 	s64 bfree;
5234 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5235 
5236 	if (!test_opt(sb, MINIX_DF))
5237 		overhead = sbi->s_overhead;
5238 
5239 	buf->f_type = EXT4_SUPER_MAGIC;
5240 	buf->f_bsize = sb->s_blocksize;
5241 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5242 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5243 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5244 	/* prevent underflow in case that few free space is available */
5245 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5246 	buf->f_bavail = buf->f_bfree -
5247 			(ext4_r_blocks_count(es) + resv_blocks);
5248 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5249 		buf->f_bavail = 0;
5250 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5251 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5252 	buf->f_namelen = EXT4_NAME_LEN;
5253 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5254 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5255 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5256 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5257 
5258 #ifdef CONFIG_QUOTA
5259 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5260 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5261 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5262 #endif
5263 	return 0;
5264 }
5265 
5266 /* Helper function for writing quotas on sync - we need to start transaction
5267  * before quota file is locked for write. Otherwise the are possible deadlocks:
5268  * Process 1                         Process 2
5269  * ext4_create()                     quota_sync()
5270  *   jbd2_journal_start()                  write_dquot()
5271  *   dquot_initialize()                         down(dqio_mutex)
5272  *     down(dqio_mutex)                    jbd2_journal_start()
5273  *
5274  */
5275 
5276 #ifdef CONFIG_QUOTA
5277 
5278 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5279 {
5280 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5281 }
5282 
5283 static int ext4_write_dquot(struct dquot *dquot)
5284 {
5285 	int ret, err;
5286 	handle_t *handle;
5287 	struct inode *inode;
5288 
5289 	inode = dquot_to_inode(dquot);
5290 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5291 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5292 	if (IS_ERR(handle))
5293 		return PTR_ERR(handle);
5294 	ret = dquot_commit(dquot);
5295 	err = ext4_journal_stop(handle);
5296 	if (!ret)
5297 		ret = err;
5298 	return ret;
5299 }
5300 
5301 static int ext4_acquire_dquot(struct dquot *dquot)
5302 {
5303 	int ret, err;
5304 	handle_t *handle;
5305 
5306 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5307 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5308 	if (IS_ERR(handle))
5309 		return PTR_ERR(handle);
5310 	ret = dquot_acquire(dquot);
5311 	err = ext4_journal_stop(handle);
5312 	if (!ret)
5313 		ret = err;
5314 	return ret;
5315 }
5316 
5317 static int ext4_release_dquot(struct dquot *dquot)
5318 {
5319 	int ret, err;
5320 	handle_t *handle;
5321 
5322 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5323 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5324 	if (IS_ERR(handle)) {
5325 		/* Release dquot anyway to avoid endless cycle in dqput() */
5326 		dquot_release(dquot);
5327 		return PTR_ERR(handle);
5328 	}
5329 	ret = dquot_release(dquot);
5330 	err = ext4_journal_stop(handle);
5331 	if (!ret)
5332 		ret = err;
5333 	return ret;
5334 }
5335 
5336 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5337 {
5338 	struct super_block *sb = dquot->dq_sb;
5339 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5340 
5341 	/* Are we journaling quotas? */
5342 	if (ext4_has_feature_quota(sb) ||
5343 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5344 		dquot_mark_dquot_dirty(dquot);
5345 		return ext4_write_dquot(dquot);
5346 	} else {
5347 		return dquot_mark_dquot_dirty(dquot);
5348 	}
5349 }
5350 
5351 static int ext4_write_info(struct super_block *sb, int type)
5352 {
5353 	int ret, err;
5354 	handle_t *handle;
5355 
5356 	/* Data block + inode block */
5357 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5358 	if (IS_ERR(handle))
5359 		return PTR_ERR(handle);
5360 	ret = dquot_commit_info(sb, type);
5361 	err = ext4_journal_stop(handle);
5362 	if (!ret)
5363 		ret = err;
5364 	return ret;
5365 }
5366 
5367 /*
5368  * Turn on quotas during mount time - we need to find
5369  * the quota file and such...
5370  */
5371 static int ext4_quota_on_mount(struct super_block *sb, int type)
5372 {
5373 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5374 					EXT4_SB(sb)->s_jquota_fmt, type);
5375 }
5376 
5377 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5378 {
5379 	struct ext4_inode_info *ei = EXT4_I(inode);
5380 
5381 	/* The first argument of lockdep_set_subclass has to be
5382 	 * *exactly* the same as the argument to init_rwsem() --- in
5383 	 * this case, in init_once() --- or lockdep gets unhappy
5384 	 * because the name of the lock is set using the
5385 	 * stringification of the argument to init_rwsem().
5386 	 */
5387 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5388 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5389 }
5390 
5391 /*
5392  * Standard function to be called on quota_on
5393  */
5394 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5395 			 const struct path *path)
5396 {
5397 	int err;
5398 
5399 	if (!test_opt(sb, QUOTA))
5400 		return -EINVAL;
5401 
5402 	/* Quotafile not on the same filesystem? */
5403 	if (path->dentry->d_sb != sb)
5404 		return -EXDEV;
5405 	/* Journaling quota? */
5406 	if (EXT4_SB(sb)->s_qf_names[type]) {
5407 		/* Quotafile not in fs root? */
5408 		if (path->dentry->d_parent != sb->s_root)
5409 			ext4_msg(sb, KERN_WARNING,
5410 				"Quota file not on filesystem root. "
5411 				"Journaled quota will not work");
5412 	}
5413 
5414 	/*
5415 	 * When we journal data on quota file, we have to flush journal to see
5416 	 * all updates to the file when we bypass pagecache...
5417 	 */
5418 	if (EXT4_SB(sb)->s_journal &&
5419 	    ext4_should_journal_data(d_inode(path->dentry))) {
5420 		/*
5421 		 * We don't need to lock updates but journal_flush() could
5422 		 * otherwise be livelocked...
5423 		 */
5424 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5425 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5426 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5427 		if (err)
5428 			return err;
5429 	}
5430 
5431 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5432 	err = dquot_quota_on(sb, type, format_id, path);
5433 	if (err) {
5434 		lockdep_set_quota_inode(path->dentry->d_inode,
5435 					     I_DATA_SEM_NORMAL);
5436 	} else {
5437 		struct inode *inode = d_inode(path->dentry);
5438 		handle_t *handle;
5439 
5440 		/*
5441 		 * Set inode flags to prevent userspace from messing with quota
5442 		 * files. If this fails, we return success anyway since quotas
5443 		 * are already enabled and this is not a hard failure.
5444 		 */
5445 		inode_lock(inode);
5446 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5447 		if (IS_ERR(handle))
5448 			goto unlock_inode;
5449 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5450 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5451 				S_NOATIME | S_IMMUTABLE);
5452 		ext4_mark_inode_dirty(handle, inode);
5453 		ext4_journal_stop(handle);
5454 	unlock_inode:
5455 		inode_unlock(inode);
5456 	}
5457 	return err;
5458 }
5459 
5460 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5461 			     unsigned int flags)
5462 {
5463 	int err;
5464 	struct inode *qf_inode;
5465 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5466 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5467 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5468 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5469 	};
5470 
5471 	BUG_ON(!ext4_has_feature_quota(sb));
5472 
5473 	if (!qf_inums[type])
5474 		return -EPERM;
5475 
5476 	qf_inode = ext4_iget(sb, qf_inums[type]);
5477 	if (IS_ERR(qf_inode)) {
5478 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5479 		return PTR_ERR(qf_inode);
5480 	}
5481 
5482 	/* Don't account quota for quota files to avoid recursion */
5483 	qf_inode->i_flags |= S_NOQUOTA;
5484 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5485 	err = dquot_enable(qf_inode, type, format_id, flags);
5486 	iput(qf_inode);
5487 	if (err)
5488 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5489 
5490 	return err;
5491 }
5492 
5493 /* Enable usage tracking for all quota types. */
5494 static int ext4_enable_quotas(struct super_block *sb)
5495 {
5496 	int type, err = 0;
5497 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5498 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5499 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5500 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5501 	};
5502 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5503 		test_opt(sb, USRQUOTA),
5504 		test_opt(sb, GRPQUOTA),
5505 		test_opt(sb, PRJQUOTA),
5506 	};
5507 
5508 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5509 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5510 		if (qf_inums[type]) {
5511 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5512 				DQUOT_USAGE_ENABLED |
5513 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5514 			if (err) {
5515 				ext4_warning(sb,
5516 					"Failed to enable quota tracking "
5517 					"(type=%d, err=%d). Please run "
5518 					"e2fsck to fix.", type, err);
5519 				return err;
5520 			}
5521 		}
5522 	}
5523 	return 0;
5524 }
5525 
5526 static int ext4_quota_off(struct super_block *sb, int type)
5527 {
5528 	struct inode *inode = sb_dqopt(sb)->files[type];
5529 	handle_t *handle;
5530 	int err;
5531 
5532 	/* Force all delayed allocation blocks to be allocated.
5533 	 * Caller already holds s_umount sem */
5534 	if (test_opt(sb, DELALLOC))
5535 		sync_filesystem(sb);
5536 
5537 	if (!inode || !igrab(inode))
5538 		goto out;
5539 
5540 	err = dquot_quota_off(sb, type);
5541 	if (err || ext4_has_feature_quota(sb))
5542 		goto out_put;
5543 
5544 	inode_lock(inode);
5545 	/*
5546 	 * Update modification times of quota files when userspace can
5547 	 * start looking at them. If we fail, we return success anyway since
5548 	 * this is not a hard failure and quotas are already disabled.
5549 	 */
5550 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5551 	if (IS_ERR(handle))
5552 		goto out_unlock;
5553 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5554 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5555 	inode->i_mtime = inode->i_ctime = current_time(inode);
5556 	ext4_mark_inode_dirty(handle, inode);
5557 	ext4_journal_stop(handle);
5558 out_unlock:
5559 	inode_unlock(inode);
5560 out_put:
5561 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5562 	iput(inode);
5563 	return err;
5564 out:
5565 	return dquot_quota_off(sb, type);
5566 }
5567 
5568 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5569  * acquiring the locks... As quota files are never truncated and quota code
5570  * itself serializes the operations (and no one else should touch the files)
5571  * we don't have to be afraid of races */
5572 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5573 			       size_t len, loff_t off)
5574 {
5575 	struct inode *inode = sb_dqopt(sb)->files[type];
5576 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5577 	int offset = off & (sb->s_blocksize - 1);
5578 	int tocopy;
5579 	size_t toread;
5580 	struct buffer_head *bh;
5581 	loff_t i_size = i_size_read(inode);
5582 
5583 	if (off > i_size)
5584 		return 0;
5585 	if (off+len > i_size)
5586 		len = i_size-off;
5587 	toread = len;
5588 	while (toread > 0) {
5589 		tocopy = sb->s_blocksize - offset < toread ?
5590 				sb->s_blocksize - offset : toread;
5591 		bh = ext4_bread(NULL, inode, blk, 0);
5592 		if (IS_ERR(bh))
5593 			return PTR_ERR(bh);
5594 		if (!bh)	/* A hole? */
5595 			memset(data, 0, tocopy);
5596 		else
5597 			memcpy(data, bh->b_data+offset, tocopy);
5598 		brelse(bh);
5599 		offset = 0;
5600 		toread -= tocopy;
5601 		data += tocopy;
5602 		blk++;
5603 	}
5604 	return len;
5605 }
5606 
5607 /* Write to quotafile (we know the transaction is already started and has
5608  * enough credits) */
5609 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5610 				const char *data, size_t len, loff_t off)
5611 {
5612 	struct inode *inode = sb_dqopt(sb)->files[type];
5613 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5614 	int err, offset = off & (sb->s_blocksize - 1);
5615 	int retries = 0;
5616 	struct buffer_head *bh;
5617 	handle_t *handle = journal_current_handle();
5618 
5619 	if (EXT4_SB(sb)->s_journal && !handle) {
5620 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5621 			" cancelled because transaction is not started",
5622 			(unsigned long long)off, (unsigned long long)len);
5623 		return -EIO;
5624 	}
5625 	/*
5626 	 * Since we account only one data block in transaction credits,
5627 	 * then it is impossible to cross a block boundary.
5628 	 */
5629 	if (sb->s_blocksize - offset < len) {
5630 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5631 			" cancelled because not block aligned",
5632 			(unsigned long long)off, (unsigned long long)len);
5633 		return -EIO;
5634 	}
5635 
5636 	do {
5637 		bh = ext4_bread(handle, inode, blk,
5638 				EXT4_GET_BLOCKS_CREATE |
5639 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5640 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5641 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5642 	if (IS_ERR(bh))
5643 		return PTR_ERR(bh);
5644 	if (!bh)
5645 		goto out;
5646 	BUFFER_TRACE(bh, "get write access");
5647 	err = ext4_journal_get_write_access(handle, bh);
5648 	if (err) {
5649 		brelse(bh);
5650 		return err;
5651 	}
5652 	lock_buffer(bh);
5653 	memcpy(bh->b_data+offset, data, len);
5654 	flush_dcache_page(bh->b_page);
5655 	unlock_buffer(bh);
5656 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5657 	brelse(bh);
5658 out:
5659 	if (inode->i_size < off + len) {
5660 		i_size_write(inode, off + len);
5661 		EXT4_I(inode)->i_disksize = inode->i_size;
5662 		ext4_mark_inode_dirty(handle, inode);
5663 	}
5664 	return len;
5665 }
5666 
5667 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5668 {
5669 	const struct quota_format_ops	*ops;
5670 
5671 	if (!sb_has_quota_loaded(sb, qid->type))
5672 		return -ESRCH;
5673 	ops = sb_dqopt(sb)->ops[qid->type];
5674 	if (!ops || !ops->get_next_id)
5675 		return -ENOSYS;
5676 	return dquot_get_next_id(sb, qid);
5677 }
5678 #endif
5679 
5680 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5681 		       const char *dev_name, void *data)
5682 {
5683 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5684 }
5685 
5686 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5687 static inline void register_as_ext2(void)
5688 {
5689 	int err = register_filesystem(&ext2_fs_type);
5690 	if (err)
5691 		printk(KERN_WARNING
5692 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5693 }
5694 
5695 static inline void unregister_as_ext2(void)
5696 {
5697 	unregister_filesystem(&ext2_fs_type);
5698 }
5699 
5700 static inline int ext2_feature_set_ok(struct super_block *sb)
5701 {
5702 	if (ext4_has_unknown_ext2_incompat_features(sb))
5703 		return 0;
5704 	if (sb->s_flags & MS_RDONLY)
5705 		return 1;
5706 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5707 		return 0;
5708 	return 1;
5709 }
5710 #else
5711 static inline void register_as_ext2(void) { }
5712 static inline void unregister_as_ext2(void) { }
5713 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5714 #endif
5715 
5716 static inline void register_as_ext3(void)
5717 {
5718 	int err = register_filesystem(&ext3_fs_type);
5719 	if (err)
5720 		printk(KERN_WARNING
5721 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5722 }
5723 
5724 static inline void unregister_as_ext3(void)
5725 {
5726 	unregister_filesystem(&ext3_fs_type);
5727 }
5728 
5729 static inline int ext3_feature_set_ok(struct super_block *sb)
5730 {
5731 	if (ext4_has_unknown_ext3_incompat_features(sb))
5732 		return 0;
5733 	if (!ext4_has_feature_journal(sb))
5734 		return 0;
5735 	if (sb->s_flags & MS_RDONLY)
5736 		return 1;
5737 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5738 		return 0;
5739 	return 1;
5740 }
5741 
5742 static struct file_system_type ext4_fs_type = {
5743 	.owner		= THIS_MODULE,
5744 	.name		= "ext4",
5745 	.mount		= ext4_mount,
5746 	.kill_sb	= kill_block_super,
5747 	.fs_flags	= FS_REQUIRES_DEV,
5748 };
5749 MODULE_ALIAS_FS("ext4");
5750 
5751 /* Shared across all ext4 file systems */
5752 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5753 
5754 static int __init ext4_init_fs(void)
5755 {
5756 	int i, err;
5757 
5758 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5759 	ext4_li_info = NULL;
5760 	mutex_init(&ext4_li_mtx);
5761 
5762 	/* Build-time check for flags consistency */
5763 	ext4_check_flag_values();
5764 
5765 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5766 		init_waitqueue_head(&ext4__ioend_wq[i]);
5767 
5768 	err = ext4_init_es();
5769 	if (err)
5770 		return err;
5771 
5772 	err = ext4_init_pageio();
5773 	if (err)
5774 		goto out5;
5775 
5776 	err = ext4_init_system_zone();
5777 	if (err)
5778 		goto out4;
5779 
5780 	err = ext4_init_sysfs();
5781 	if (err)
5782 		goto out3;
5783 
5784 	err = ext4_init_mballoc();
5785 	if (err)
5786 		goto out2;
5787 	err = init_inodecache();
5788 	if (err)
5789 		goto out1;
5790 	register_as_ext3();
5791 	register_as_ext2();
5792 	err = register_filesystem(&ext4_fs_type);
5793 	if (err)
5794 		goto out;
5795 
5796 	return 0;
5797 out:
5798 	unregister_as_ext2();
5799 	unregister_as_ext3();
5800 	destroy_inodecache();
5801 out1:
5802 	ext4_exit_mballoc();
5803 out2:
5804 	ext4_exit_sysfs();
5805 out3:
5806 	ext4_exit_system_zone();
5807 out4:
5808 	ext4_exit_pageio();
5809 out5:
5810 	ext4_exit_es();
5811 
5812 	return err;
5813 }
5814 
5815 static void __exit ext4_exit_fs(void)
5816 {
5817 	ext4_destroy_lazyinit_thread();
5818 	unregister_as_ext2();
5819 	unregister_as_ext3();
5820 	unregister_filesystem(&ext4_fs_type);
5821 	destroy_inodecache();
5822 	ext4_exit_mballoc();
5823 	ext4_exit_sysfs();
5824 	ext4_exit_system_zone();
5825 	ext4_exit_pageio();
5826 	ext4_exit_es();
5827 }
5828 
5829 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5830 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5831 MODULE_LICENSE("GPL");
5832 module_init(ext4_init_fs)
5833 module_exit(ext4_exit_fs)
5834