xref: /linux/fs/ext4/super.c (revision 9a3853587c2bb0a38c2ce80a613ace5e84ae4337)
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 #include <linux/iversion.h>
44 
45 #include <linux/kthread.h>
46 #include <linux/freezer.h>
47 
48 #include "ext4.h"
49 #include "ext4_extents.h"	/* Needed for trace points definition */
50 #include "ext4_jbd2.h"
51 #include "xattr.h"
52 #include "acl.h"
53 #include "mballoc.h"
54 #include "fsmap.h"
55 
56 #define CREATE_TRACE_POINTS
57 #include <trace/events/ext4.h>
58 
59 static struct ext4_lazy_init *ext4_li_info;
60 static struct mutex ext4_li_mtx;
61 static struct ratelimit_state ext4_mount_msg_ratelimit;
62 
63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
64 			     unsigned long journal_devnum);
65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
66 static int ext4_commit_super(struct super_block *sb, int sync);
67 static void ext4_mark_recovery_complete(struct super_block *sb,
68 					struct ext4_super_block *es);
69 static void ext4_clear_journal_err(struct super_block *sb,
70 				   struct ext4_super_block *es);
71 static int ext4_sync_fs(struct super_block *sb, int wait);
72 static int ext4_remount(struct super_block *sb, int *flags, char *data);
73 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
74 static int ext4_unfreeze(struct super_block *sb);
75 static int ext4_freeze(struct super_block *sb);
76 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
77 		       const char *dev_name, void *data);
78 static inline int ext2_feature_set_ok(struct super_block *sb);
79 static inline int ext3_feature_set_ok(struct super_block *sb);
80 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
81 static void ext4_destroy_lazyinit_thread(void);
82 static void ext4_unregister_li_request(struct super_block *sb);
83 static void ext4_clear_request_list(void);
84 static struct inode *ext4_get_journal_inode(struct super_block *sb,
85 					    unsigned int journal_inum);
86 
87 /*
88  * Lock ordering
89  *
90  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
91  * i_mmap_rwsem (inode->i_mmap_rwsem)!
92  *
93  * page fault path:
94  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
95  *   page lock -> i_data_sem (rw)
96  *
97  * buffered write path:
98  * sb_start_write -> i_mutex -> mmap_sem
99  * sb_start_write -> i_mutex -> transaction start -> page lock ->
100  *   i_data_sem (rw)
101  *
102  * truncate:
103  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
104  *   i_mmap_rwsem (w) -> page lock
105  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
106  *   transaction start -> i_data_sem (rw)
107  *
108  * direct IO:
109  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
110  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
111  *   transaction start -> i_data_sem (rw)
112  *
113  * writepages:
114  * transaction start -> page lock(s) -> i_data_sem (rw)
115  */
116 
117 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
118 static struct file_system_type ext2_fs_type = {
119 	.owner		= THIS_MODULE,
120 	.name		= "ext2",
121 	.mount		= ext4_mount,
122 	.kill_sb	= kill_block_super,
123 	.fs_flags	= FS_REQUIRES_DEV,
124 };
125 MODULE_ALIAS_FS("ext2");
126 MODULE_ALIAS("ext2");
127 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
128 #else
129 #define IS_EXT2_SB(sb) (0)
130 #endif
131 
132 
133 static struct file_system_type ext3_fs_type = {
134 	.owner		= THIS_MODULE,
135 	.name		= "ext3",
136 	.mount		= ext4_mount,
137 	.kill_sb	= kill_block_super,
138 	.fs_flags	= FS_REQUIRES_DEV,
139 };
140 MODULE_ALIAS_FS("ext3");
141 MODULE_ALIAS("ext3");
142 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
143 
144 static int ext4_verify_csum_type(struct super_block *sb,
145 				 struct ext4_super_block *es)
146 {
147 	if (!ext4_has_feature_metadata_csum(sb))
148 		return 1;
149 
150 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
151 }
152 
153 static __le32 ext4_superblock_csum(struct super_block *sb,
154 				   struct ext4_super_block *es)
155 {
156 	struct ext4_sb_info *sbi = EXT4_SB(sb);
157 	int offset = offsetof(struct ext4_super_block, s_checksum);
158 	__u32 csum;
159 
160 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
161 
162 	return cpu_to_le32(csum);
163 }
164 
165 static int ext4_superblock_csum_verify(struct super_block *sb,
166 				       struct ext4_super_block *es)
167 {
168 	if (!ext4_has_metadata_csum(sb))
169 		return 1;
170 
171 	return es->s_checksum == ext4_superblock_csum(sb, es);
172 }
173 
174 void ext4_superblock_csum_set(struct super_block *sb)
175 {
176 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
177 
178 	if (!ext4_has_metadata_csum(sb))
179 		return;
180 
181 	es->s_checksum = ext4_superblock_csum(sb, es);
182 }
183 
184 void *ext4_kvmalloc(size_t size, gfp_t flags)
185 {
186 	void *ret;
187 
188 	ret = kmalloc(size, flags | __GFP_NOWARN);
189 	if (!ret)
190 		ret = __vmalloc(size, flags, PAGE_KERNEL);
191 	return ret;
192 }
193 
194 void *ext4_kvzalloc(size_t size, gfp_t flags)
195 {
196 	void *ret;
197 
198 	ret = kzalloc(size, flags | __GFP_NOWARN);
199 	if (!ret)
200 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
201 	return ret;
202 }
203 
204 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
205 			       struct ext4_group_desc *bg)
206 {
207 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
208 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
209 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
210 }
211 
212 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
213 			       struct ext4_group_desc *bg)
214 {
215 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
216 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
217 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
218 }
219 
220 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
221 			      struct ext4_group_desc *bg)
222 {
223 	return le32_to_cpu(bg->bg_inode_table_lo) |
224 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
225 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
226 }
227 
228 __u32 ext4_free_group_clusters(struct super_block *sb,
229 			       struct ext4_group_desc *bg)
230 {
231 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
232 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
233 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
234 }
235 
236 __u32 ext4_free_inodes_count(struct super_block *sb,
237 			      struct ext4_group_desc *bg)
238 {
239 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
240 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
241 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
242 }
243 
244 __u32 ext4_used_dirs_count(struct super_block *sb,
245 			      struct ext4_group_desc *bg)
246 {
247 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
248 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
249 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
250 }
251 
252 __u32 ext4_itable_unused_count(struct super_block *sb,
253 			      struct ext4_group_desc *bg)
254 {
255 	return le16_to_cpu(bg->bg_itable_unused_lo) |
256 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
257 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
258 }
259 
260 void ext4_block_bitmap_set(struct super_block *sb,
261 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
262 {
263 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
264 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
265 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
266 }
267 
268 void ext4_inode_bitmap_set(struct super_block *sb,
269 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
270 {
271 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
272 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
273 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
274 }
275 
276 void ext4_inode_table_set(struct super_block *sb,
277 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
278 {
279 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
280 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
281 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
282 }
283 
284 void ext4_free_group_clusters_set(struct super_block *sb,
285 				  struct ext4_group_desc *bg, __u32 count)
286 {
287 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
288 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
289 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
290 }
291 
292 void ext4_free_inodes_set(struct super_block *sb,
293 			  struct ext4_group_desc *bg, __u32 count)
294 {
295 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
296 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
297 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
298 }
299 
300 void ext4_used_dirs_set(struct super_block *sb,
301 			  struct ext4_group_desc *bg, __u32 count)
302 {
303 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
304 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
305 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
306 }
307 
308 void ext4_itable_unused_set(struct super_block *sb,
309 			  struct ext4_group_desc *bg, __u32 count)
310 {
311 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
312 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
313 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
314 }
315 
316 
317 static void __save_error_info(struct super_block *sb, const char *func,
318 			    unsigned int line)
319 {
320 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
321 
322 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
323 	if (bdev_read_only(sb->s_bdev))
324 		return;
325 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
326 	es->s_last_error_time = cpu_to_le32(get_seconds());
327 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
328 	es->s_last_error_line = cpu_to_le32(line);
329 	if (!es->s_first_error_time) {
330 		es->s_first_error_time = es->s_last_error_time;
331 		strncpy(es->s_first_error_func, func,
332 			sizeof(es->s_first_error_func));
333 		es->s_first_error_line = cpu_to_le32(line);
334 		es->s_first_error_ino = es->s_last_error_ino;
335 		es->s_first_error_block = es->s_last_error_block;
336 	}
337 	/*
338 	 * Start the daily error reporting function if it hasn't been
339 	 * started already
340 	 */
341 	if (!es->s_error_count)
342 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
343 	le32_add_cpu(&es->s_error_count, 1);
344 }
345 
346 static void save_error_info(struct super_block *sb, const char *func,
347 			    unsigned int line)
348 {
349 	__save_error_info(sb, func, line);
350 	ext4_commit_super(sb, 1);
351 }
352 
353 /*
354  * The del_gendisk() function uninitializes the disk-specific data
355  * structures, including the bdi structure, without telling anyone
356  * else.  Once this happens, any attempt to call mark_buffer_dirty()
357  * (for example, by ext4_commit_super), will cause a kernel OOPS.
358  * This is a kludge to prevent these oops until we can put in a proper
359  * hook in del_gendisk() to inform the VFS and file system layers.
360  */
361 static int block_device_ejected(struct super_block *sb)
362 {
363 	struct inode *bd_inode = sb->s_bdev->bd_inode;
364 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
365 
366 	return bdi->dev == NULL;
367 }
368 
369 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
370 {
371 	struct super_block		*sb = journal->j_private;
372 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
373 	int				error = is_journal_aborted(journal);
374 	struct ext4_journal_cb_entry	*jce;
375 
376 	BUG_ON(txn->t_state == T_FINISHED);
377 
378 	ext4_process_freed_data(sb, txn->t_tid);
379 
380 	spin_lock(&sbi->s_md_lock);
381 	while (!list_empty(&txn->t_private_list)) {
382 		jce = list_entry(txn->t_private_list.next,
383 				 struct ext4_journal_cb_entry, jce_list);
384 		list_del_init(&jce->jce_list);
385 		spin_unlock(&sbi->s_md_lock);
386 		jce->jce_func(sb, jce, error);
387 		spin_lock(&sbi->s_md_lock);
388 	}
389 	spin_unlock(&sbi->s_md_lock);
390 }
391 
392 /* Deal with the reporting of failure conditions on a filesystem such as
393  * inconsistencies detected or read IO failures.
394  *
395  * On ext2, we can store the error state of the filesystem in the
396  * superblock.  That is not possible on ext4, because we may have other
397  * write ordering constraints on the superblock which prevent us from
398  * writing it out straight away; and given that the journal is about to
399  * be aborted, we can't rely on the current, or future, transactions to
400  * write out the superblock safely.
401  *
402  * We'll just use the jbd2_journal_abort() error code to record an error in
403  * the journal instead.  On recovery, the journal will complain about
404  * that error until we've noted it down and cleared it.
405  */
406 
407 static void ext4_handle_error(struct super_block *sb)
408 {
409 	if (sb_rdonly(sb))
410 		return;
411 
412 	if (!test_opt(sb, ERRORS_CONT)) {
413 		journal_t *journal = EXT4_SB(sb)->s_journal;
414 
415 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
416 		if (journal)
417 			jbd2_journal_abort(journal, -EIO);
418 	}
419 	if (test_opt(sb, ERRORS_RO)) {
420 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
421 		/*
422 		 * Make sure updated value of ->s_mount_flags will be visible
423 		 * before ->s_flags update
424 		 */
425 		smp_wmb();
426 		sb->s_flags |= SB_RDONLY;
427 	}
428 	if (test_opt(sb, ERRORS_PANIC)) {
429 		if (EXT4_SB(sb)->s_journal &&
430 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
431 			return;
432 		panic("EXT4-fs (device %s): panic forced after error\n",
433 			sb->s_id);
434 	}
435 }
436 
437 #define ext4_error_ratelimit(sb)					\
438 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
439 			     "EXT4-fs error")
440 
441 void __ext4_error(struct super_block *sb, const char *function,
442 		  unsigned int line, const char *fmt, ...)
443 {
444 	struct va_format vaf;
445 	va_list args;
446 
447 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
448 		return;
449 
450 	if (ext4_error_ratelimit(sb)) {
451 		va_start(args, fmt);
452 		vaf.fmt = fmt;
453 		vaf.va = &args;
454 		printk(KERN_CRIT
455 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
456 		       sb->s_id, function, line, current->comm, &vaf);
457 		va_end(args);
458 	}
459 	save_error_info(sb, function, line);
460 	ext4_handle_error(sb);
461 }
462 
463 void __ext4_error_inode(struct inode *inode, const char *function,
464 			unsigned int line, ext4_fsblk_t block,
465 			const char *fmt, ...)
466 {
467 	va_list args;
468 	struct va_format vaf;
469 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
470 
471 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
472 		return;
473 
474 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
475 	es->s_last_error_block = cpu_to_le64(block);
476 	if (ext4_error_ratelimit(inode->i_sb)) {
477 		va_start(args, fmt);
478 		vaf.fmt = fmt;
479 		vaf.va = &args;
480 		if (block)
481 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
482 			       "inode #%lu: block %llu: comm %s: %pV\n",
483 			       inode->i_sb->s_id, function, line, inode->i_ino,
484 			       block, current->comm, &vaf);
485 		else
486 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
487 			       "inode #%lu: comm %s: %pV\n",
488 			       inode->i_sb->s_id, function, line, inode->i_ino,
489 			       current->comm, &vaf);
490 		va_end(args);
491 	}
492 	save_error_info(inode->i_sb, function, line);
493 	ext4_handle_error(inode->i_sb);
494 }
495 
496 void __ext4_error_file(struct file *file, const char *function,
497 		       unsigned int line, ext4_fsblk_t block,
498 		       const char *fmt, ...)
499 {
500 	va_list args;
501 	struct va_format vaf;
502 	struct ext4_super_block *es;
503 	struct inode *inode = file_inode(file);
504 	char pathname[80], *path;
505 
506 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
507 		return;
508 
509 	es = EXT4_SB(inode->i_sb)->s_es;
510 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
511 	if (ext4_error_ratelimit(inode->i_sb)) {
512 		path = file_path(file, pathname, sizeof(pathname));
513 		if (IS_ERR(path))
514 			path = "(unknown)";
515 		va_start(args, fmt);
516 		vaf.fmt = fmt;
517 		vaf.va = &args;
518 		if (block)
519 			printk(KERN_CRIT
520 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
521 			       "block %llu: comm %s: path %s: %pV\n",
522 			       inode->i_sb->s_id, function, line, inode->i_ino,
523 			       block, current->comm, path, &vaf);
524 		else
525 			printk(KERN_CRIT
526 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
527 			       "comm %s: path %s: %pV\n",
528 			       inode->i_sb->s_id, function, line, inode->i_ino,
529 			       current->comm, path, &vaf);
530 		va_end(args);
531 	}
532 	save_error_info(inode->i_sb, function, line);
533 	ext4_handle_error(inode->i_sb);
534 }
535 
536 const char *ext4_decode_error(struct super_block *sb, int errno,
537 			      char nbuf[16])
538 {
539 	char *errstr = NULL;
540 
541 	switch (errno) {
542 	case -EFSCORRUPTED:
543 		errstr = "Corrupt filesystem";
544 		break;
545 	case -EFSBADCRC:
546 		errstr = "Filesystem failed CRC";
547 		break;
548 	case -EIO:
549 		errstr = "IO failure";
550 		break;
551 	case -ENOMEM:
552 		errstr = "Out of memory";
553 		break;
554 	case -EROFS:
555 		if (!sb || (EXT4_SB(sb)->s_journal &&
556 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
557 			errstr = "Journal has aborted";
558 		else
559 			errstr = "Readonly filesystem";
560 		break;
561 	default:
562 		/* If the caller passed in an extra buffer for unknown
563 		 * errors, textualise them now.  Else we just return
564 		 * NULL. */
565 		if (nbuf) {
566 			/* Check for truncated error codes... */
567 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
568 				errstr = nbuf;
569 		}
570 		break;
571 	}
572 
573 	return errstr;
574 }
575 
576 /* __ext4_std_error decodes expected errors from journaling functions
577  * automatically and invokes the appropriate error response.  */
578 
579 void __ext4_std_error(struct super_block *sb, const char *function,
580 		      unsigned int line, int errno)
581 {
582 	char nbuf[16];
583 	const char *errstr;
584 
585 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
586 		return;
587 
588 	/* Special case: if the error is EROFS, and we're not already
589 	 * inside a transaction, then there's really no point in logging
590 	 * an error. */
591 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
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_rdonly(sb) == 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 |= SB_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_rdonly(sb) && !aborted) {
893 		ext4_clear_feature_journal_needs_recovery(sb);
894 		es->s_state = cpu_to_le16(sbi->s_mount_state);
895 	}
896 	if (!sb_rdonly(sb))
897 		ext4_commit_super(sb, 1);
898 
899 	for (i = 0; i < sbi->s_gdb_count; i++)
900 		brelse(sbi->s_group_desc[i]);
901 	kvfree(sbi->s_group_desc);
902 	kvfree(sbi->s_flex_groups);
903 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
904 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
905 	percpu_counter_destroy(&sbi->s_dirs_counter);
906 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
907 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
908 #ifdef CONFIG_QUOTA
909 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
910 		kfree(sbi->s_qf_names[i]);
911 #endif
912 
913 	/* Debugging code just in case the in-memory inode orphan list
914 	 * isn't empty.  The on-disk one can be non-empty if we've
915 	 * detected an error and taken the fs readonly, but the
916 	 * in-memory list had better be clean by this point. */
917 	if (!list_empty(&sbi->s_orphan))
918 		dump_orphan_list(sb, sbi);
919 	J_ASSERT(list_empty(&sbi->s_orphan));
920 
921 	sync_blockdev(sb->s_bdev);
922 	invalidate_bdev(sb->s_bdev);
923 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
924 		/*
925 		 * Invalidate the journal device's buffers.  We don't want them
926 		 * floating about in memory - the physical journal device may
927 		 * hotswapped, and it breaks the `ro-after' testing code.
928 		 */
929 		sync_blockdev(sbi->journal_bdev);
930 		invalidate_bdev(sbi->journal_bdev);
931 		ext4_blkdev_remove(sbi);
932 	}
933 	if (sbi->s_ea_inode_cache) {
934 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
935 		sbi->s_ea_inode_cache = NULL;
936 	}
937 	if (sbi->s_ea_block_cache) {
938 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
939 		sbi->s_ea_block_cache = NULL;
940 	}
941 	if (sbi->s_mmp_tsk)
942 		kthread_stop(sbi->s_mmp_tsk);
943 	brelse(sbi->s_sbh);
944 	sb->s_fs_info = NULL;
945 	/*
946 	 * Now that we are completely done shutting down the
947 	 * superblock, we need to actually destroy the kobject.
948 	 */
949 	kobject_put(&sbi->s_kobj);
950 	wait_for_completion(&sbi->s_kobj_unregister);
951 	if (sbi->s_chksum_driver)
952 		crypto_free_shash(sbi->s_chksum_driver);
953 	kfree(sbi->s_blockgroup_lock);
954 	fs_put_dax(sbi->s_daxdev);
955 	kfree(sbi);
956 }
957 
958 static struct kmem_cache *ext4_inode_cachep;
959 
960 /*
961  * Called inside transaction, so use GFP_NOFS
962  */
963 static struct inode *ext4_alloc_inode(struct super_block *sb)
964 {
965 	struct ext4_inode_info *ei;
966 
967 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
968 	if (!ei)
969 		return NULL;
970 
971 	inode_set_iversion(&ei->vfs_inode, 1);
972 	spin_lock_init(&ei->i_raw_lock);
973 	INIT_LIST_HEAD(&ei->i_prealloc_list);
974 	spin_lock_init(&ei->i_prealloc_lock);
975 	ext4_es_init_tree(&ei->i_es_tree);
976 	rwlock_init(&ei->i_es_lock);
977 	INIT_LIST_HEAD(&ei->i_es_list);
978 	ei->i_es_all_nr = 0;
979 	ei->i_es_shk_nr = 0;
980 	ei->i_es_shrink_lblk = 0;
981 	ei->i_reserved_data_blocks = 0;
982 	ei->i_da_metadata_calc_len = 0;
983 	ei->i_da_metadata_calc_last_lblock = 0;
984 	spin_lock_init(&(ei->i_block_reservation_lock));
985 #ifdef CONFIG_QUOTA
986 	ei->i_reserved_quota = 0;
987 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
988 #endif
989 	ei->jinode = NULL;
990 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
991 	spin_lock_init(&ei->i_completed_io_lock);
992 	ei->i_sync_tid = 0;
993 	ei->i_datasync_tid = 0;
994 	atomic_set(&ei->i_unwritten, 0);
995 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
996 	return &ei->vfs_inode;
997 }
998 
999 static int ext4_drop_inode(struct inode *inode)
1000 {
1001 	int drop = generic_drop_inode(inode);
1002 
1003 	trace_ext4_drop_inode(inode, drop);
1004 	return drop;
1005 }
1006 
1007 static void ext4_i_callback(struct rcu_head *head)
1008 {
1009 	struct inode *inode = container_of(head, struct inode, i_rcu);
1010 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1011 }
1012 
1013 static void ext4_destroy_inode(struct inode *inode)
1014 {
1015 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1016 		ext4_msg(inode->i_sb, KERN_ERR,
1017 			 "Inode %lu (%p): orphan list check failed!",
1018 			 inode->i_ino, EXT4_I(inode));
1019 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1020 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1021 				true);
1022 		dump_stack();
1023 	}
1024 	call_rcu(&inode->i_rcu, ext4_i_callback);
1025 }
1026 
1027 static void init_once(void *foo)
1028 {
1029 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1030 
1031 	INIT_LIST_HEAD(&ei->i_orphan);
1032 	init_rwsem(&ei->xattr_sem);
1033 	init_rwsem(&ei->i_data_sem);
1034 	init_rwsem(&ei->i_mmap_sem);
1035 	inode_init_once(&ei->vfs_inode);
1036 }
1037 
1038 static int __init init_inodecache(void)
1039 {
1040 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1041 					     sizeof(struct ext4_inode_info),
1042 					     0, (SLAB_RECLAIM_ACCOUNT|
1043 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1044 					     init_once);
1045 	if (ext4_inode_cachep == NULL)
1046 		return -ENOMEM;
1047 	return 0;
1048 }
1049 
1050 static void destroy_inodecache(void)
1051 {
1052 	/*
1053 	 * Make sure all delayed rcu free inodes are flushed before we
1054 	 * destroy cache.
1055 	 */
1056 	rcu_barrier();
1057 	kmem_cache_destroy(ext4_inode_cachep);
1058 }
1059 
1060 void ext4_clear_inode(struct inode *inode)
1061 {
1062 	invalidate_inode_buffers(inode);
1063 	clear_inode(inode);
1064 	dquot_drop(inode);
1065 	ext4_discard_preallocations(inode);
1066 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1067 	if (EXT4_I(inode)->jinode) {
1068 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1069 					       EXT4_I(inode)->jinode);
1070 		jbd2_free_inode(EXT4_I(inode)->jinode);
1071 		EXT4_I(inode)->jinode = NULL;
1072 	}
1073 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1074 	fscrypt_put_encryption_info(inode, NULL);
1075 #endif
1076 }
1077 
1078 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1079 					u64 ino, u32 generation)
1080 {
1081 	struct inode *inode;
1082 
1083 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1084 		return ERR_PTR(-ESTALE);
1085 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1086 		return ERR_PTR(-ESTALE);
1087 
1088 	/* iget isn't really right if the inode is currently unallocated!!
1089 	 *
1090 	 * ext4_read_inode will return a bad_inode if the inode had been
1091 	 * deleted, so we should be safe.
1092 	 *
1093 	 * Currently we don't know the generation for parent directory, so
1094 	 * a generation of 0 means "accept any"
1095 	 */
1096 	inode = ext4_iget_normal(sb, ino);
1097 	if (IS_ERR(inode))
1098 		return ERR_CAST(inode);
1099 	if (generation && inode->i_generation != generation) {
1100 		iput(inode);
1101 		return ERR_PTR(-ESTALE);
1102 	}
1103 
1104 	return inode;
1105 }
1106 
1107 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1108 					int fh_len, int fh_type)
1109 {
1110 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1111 				    ext4_nfs_get_inode);
1112 }
1113 
1114 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1115 					int fh_len, int fh_type)
1116 {
1117 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1118 				    ext4_nfs_get_inode);
1119 }
1120 
1121 /*
1122  * Try to release metadata pages (indirect blocks, directories) which are
1123  * mapped via the block device.  Since these pages could have journal heads
1124  * which would prevent try_to_free_buffers() from freeing them, we must use
1125  * jbd2 layer's try_to_free_buffers() function to release them.
1126  */
1127 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1128 				 gfp_t wait)
1129 {
1130 	journal_t *journal = EXT4_SB(sb)->s_journal;
1131 
1132 	WARN_ON(PageChecked(page));
1133 	if (!page_has_buffers(page))
1134 		return 0;
1135 	if (journal)
1136 		return jbd2_journal_try_to_free_buffers(journal, page,
1137 						wait & ~__GFP_DIRECT_RECLAIM);
1138 	return try_to_free_buffers(page);
1139 }
1140 
1141 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1142 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1143 {
1144 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1145 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1146 }
1147 
1148 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1149 							void *fs_data)
1150 {
1151 	handle_t *handle = fs_data;
1152 	int res, res2, credits, retries = 0;
1153 
1154 	/*
1155 	 * Encrypting the root directory is not allowed because e2fsck expects
1156 	 * lost+found to exist and be unencrypted, and encrypting the root
1157 	 * directory would imply encrypting the lost+found directory as well as
1158 	 * the filename "lost+found" itself.
1159 	 */
1160 	if (inode->i_ino == EXT4_ROOT_INO)
1161 		return -EPERM;
1162 
1163 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1164 		return -EINVAL;
1165 
1166 	res = ext4_convert_inline_data(inode);
1167 	if (res)
1168 		return res;
1169 
1170 	/*
1171 	 * If a journal handle was specified, then the encryption context is
1172 	 * being set on a new inode via inheritance and is part of a larger
1173 	 * transaction to create the inode.  Otherwise the encryption context is
1174 	 * being set on an existing inode in its own transaction.  Only in the
1175 	 * latter case should the "retry on ENOSPC" logic be used.
1176 	 */
1177 
1178 	if (handle) {
1179 		res = ext4_xattr_set_handle(handle, inode,
1180 					    EXT4_XATTR_INDEX_ENCRYPTION,
1181 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1182 					    ctx, len, 0);
1183 		if (!res) {
1184 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1185 			ext4_clear_inode_state(inode,
1186 					EXT4_STATE_MAY_INLINE_DATA);
1187 			/*
1188 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1189 			 * S_DAX may be disabled
1190 			 */
1191 			ext4_set_inode_flags(inode);
1192 		}
1193 		return res;
1194 	}
1195 
1196 	res = dquot_initialize(inode);
1197 	if (res)
1198 		return res;
1199 retry:
1200 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1201 				     &credits);
1202 	if (res)
1203 		return res;
1204 
1205 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1206 	if (IS_ERR(handle))
1207 		return PTR_ERR(handle);
1208 
1209 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1210 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1211 				    ctx, len, 0);
1212 	if (!res) {
1213 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1214 		/*
1215 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1216 		 * S_DAX may be disabled
1217 		 */
1218 		ext4_set_inode_flags(inode);
1219 		res = ext4_mark_inode_dirty(handle, inode);
1220 		if (res)
1221 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1222 	}
1223 	res2 = ext4_journal_stop(handle);
1224 
1225 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1226 		goto retry;
1227 	if (!res)
1228 		res = res2;
1229 	return res;
1230 }
1231 
1232 static bool ext4_dummy_context(struct inode *inode)
1233 {
1234 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1235 }
1236 
1237 static unsigned ext4_max_namelen(struct inode *inode)
1238 {
1239 	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1240 		EXT4_NAME_LEN;
1241 }
1242 
1243 static const struct fscrypt_operations ext4_cryptops = {
1244 	.key_prefix		= "ext4:",
1245 	.get_context		= ext4_get_context,
1246 	.set_context		= ext4_set_context,
1247 	.dummy_context		= ext4_dummy_context,
1248 	.empty_dir		= ext4_empty_dir,
1249 	.max_namelen		= ext4_max_namelen,
1250 };
1251 #endif
1252 
1253 #ifdef CONFIG_QUOTA
1254 static const char * const quotatypes[] = INITQFNAMES;
1255 #define QTYPE2NAME(t) (quotatypes[t])
1256 
1257 static int ext4_write_dquot(struct dquot *dquot);
1258 static int ext4_acquire_dquot(struct dquot *dquot);
1259 static int ext4_release_dquot(struct dquot *dquot);
1260 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1261 static int ext4_write_info(struct super_block *sb, int type);
1262 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1263 			 const struct path *path);
1264 static int ext4_quota_on_mount(struct super_block *sb, int type);
1265 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1266 			       size_t len, loff_t off);
1267 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1268 				const char *data, size_t len, loff_t off);
1269 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1270 			     unsigned int flags);
1271 static int ext4_enable_quotas(struct super_block *sb);
1272 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1273 
1274 static struct dquot **ext4_get_dquots(struct inode *inode)
1275 {
1276 	return EXT4_I(inode)->i_dquot;
1277 }
1278 
1279 static const struct dquot_operations ext4_quota_operations = {
1280 	.get_reserved_space	= ext4_get_reserved_space,
1281 	.write_dquot		= ext4_write_dquot,
1282 	.acquire_dquot		= ext4_acquire_dquot,
1283 	.release_dquot		= ext4_release_dquot,
1284 	.mark_dirty		= ext4_mark_dquot_dirty,
1285 	.write_info		= ext4_write_info,
1286 	.alloc_dquot		= dquot_alloc,
1287 	.destroy_dquot		= dquot_destroy,
1288 	.get_projid		= ext4_get_projid,
1289 	.get_inode_usage	= ext4_get_inode_usage,
1290 	.get_next_id		= ext4_get_next_id,
1291 };
1292 
1293 static const struct quotactl_ops ext4_qctl_operations = {
1294 	.quota_on	= ext4_quota_on,
1295 	.quota_off	= ext4_quota_off,
1296 	.quota_sync	= dquot_quota_sync,
1297 	.get_state	= dquot_get_state,
1298 	.set_info	= dquot_set_dqinfo,
1299 	.get_dqblk	= dquot_get_dqblk,
1300 	.set_dqblk	= dquot_set_dqblk,
1301 	.get_nextdqblk	= dquot_get_next_dqblk,
1302 };
1303 #endif
1304 
1305 static const struct super_operations ext4_sops = {
1306 	.alloc_inode	= ext4_alloc_inode,
1307 	.destroy_inode	= ext4_destroy_inode,
1308 	.write_inode	= ext4_write_inode,
1309 	.dirty_inode	= ext4_dirty_inode,
1310 	.drop_inode	= ext4_drop_inode,
1311 	.evict_inode	= ext4_evict_inode,
1312 	.put_super	= ext4_put_super,
1313 	.sync_fs	= ext4_sync_fs,
1314 	.freeze_fs	= ext4_freeze,
1315 	.unfreeze_fs	= ext4_unfreeze,
1316 	.statfs		= ext4_statfs,
1317 	.remount_fs	= ext4_remount,
1318 	.show_options	= ext4_show_options,
1319 #ifdef CONFIG_QUOTA
1320 	.quota_read	= ext4_quota_read,
1321 	.quota_write	= ext4_quota_write,
1322 	.get_dquots	= ext4_get_dquots,
1323 #endif
1324 	.bdev_try_to_free_page = bdev_try_to_free_page,
1325 };
1326 
1327 static const struct export_operations ext4_export_ops = {
1328 	.fh_to_dentry = ext4_fh_to_dentry,
1329 	.fh_to_parent = ext4_fh_to_parent,
1330 	.get_parent = ext4_get_parent,
1331 };
1332 
1333 enum {
1334 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1335 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1336 	Opt_nouid32, Opt_debug, Opt_removed,
1337 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1338 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1339 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1340 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1341 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1342 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1343 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1344 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1345 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1346 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1347 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1348 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1349 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1350 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1351 	Opt_dioread_nolock, Opt_dioread_lock,
1352 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1353 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1354 };
1355 
1356 static const match_table_t tokens = {
1357 	{Opt_bsd_df, "bsddf"},
1358 	{Opt_minix_df, "minixdf"},
1359 	{Opt_grpid, "grpid"},
1360 	{Opt_grpid, "bsdgroups"},
1361 	{Opt_nogrpid, "nogrpid"},
1362 	{Opt_nogrpid, "sysvgroups"},
1363 	{Opt_resgid, "resgid=%u"},
1364 	{Opt_resuid, "resuid=%u"},
1365 	{Opt_sb, "sb=%u"},
1366 	{Opt_err_cont, "errors=continue"},
1367 	{Opt_err_panic, "errors=panic"},
1368 	{Opt_err_ro, "errors=remount-ro"},
1369 	{Opt_nouid32, "nouid32"},
1370 	{Opt_debug, "debug"},
1371 	{Opt_removed, "oldalloc"},
1372 	{Opt_removed, "orlov"},
1373 	{Opt_user_xattr, "user_xattr"},
1374 	{Opt_nouser_xattr, "nouser_xattr"},
1375 	{Opt_acl, "acl"},
1376 	{Opt_noacl, "noacl"},
1377 	{Opt_noload, "norecovery"},
1378 	{Opt_noload, "noload"},
1379 	{Opt_removed, "nobh"},
1380 	{Opt_removed, "bh"},
1381 	{Opt_commit, "commit=%u"},
1382 	{Opt_min_batch_time, "min_batch_time=%u"},
1383 	{Opt_max_batch_time, "max_batch_time=%u"},
1384 	{Opt_journal_dev, "journal_dev=%u"},
1385 	{Opt_journal_path, "journal_path=%s"},
1386 	{Opt_journal_checksum, "journal_checksum"},
1387 	{Opt_nojournal_checksum, "nojournal_checksum"},
1388 	{Opt_journal_async_commit, "journal_async_commit"},
1389 	{Opt_abort, "abort"},
1390 	{Opt_data_journal, "data=journal"},
1391 	{Opt_data_ordered, "data=ordered"},
1392 	{Opt_data_writeback, "data=writeback"},
1393 	{Opt_data_err_abort, "data_err=abort"},
1394 	{Opt_data_err_ignore, "data_err=ignore"},
1395 	{Opt_offusrjquota, "usrjquota="},
1396 	{Opt_usrjquota, "usrjquota=%s"},
1397 	{Opt_offgrpjquota, "grpjquota="},
1398 	{Opt_grpjquota, "grpjquota=%s"},
1399 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1400 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1401 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1402 	{Opt_grpquota, "grpquota"},
1403 	{Opt_noquota, "noquota"},
1404 	{Opt_quota, "quota"},
1405 	{Opt_usrquota, "usrquota"},
1406 	{Opt_prjquota, "prjquota"},
1407 	{Opt_barrier, "barrier=%u"},
1408 	{Opt_barrier, "barrier"},
1409 	{Opt_nobarrier, "nobarrier"},
1410 	{Opt_i_version, "i_version"},
1411 	{Opt_dax, "dax"},
1412 	{Opt_stripe, "stripe=%u"},
1413 	{Opt_delalloc, "delalloc"},
1414 	{Opt_lazytime, "lazytime"},
1415 	{Opt_nolazytime, "nolazytime"},
1416 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1417 	{Opt_nodelalloc, "nodelalloc"},
1418 	{Opt_removed, "mblk_io_submit"},
1419 	{Opt_removed, "nomblk_io_submit"},
1420 	{Opt_block_validity, "block_validity"},
1421 	{Opt_noblock_validity, "noblock_validity"},
1422 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1423 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1424 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1425 	{Opt_auto_da_alloc, "auto_da_alloc"},
1426 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1427 	{Opt_dioread_nolock, "dioread_nolock"},
1428 	{Opt_dioread_lock, "dioread_lock"},
1429 	{Opt_discard, "discard"},
1430 	{Opt_nodiscard, "nodiscard"},
1431 	{Opt_init_itable, "init_itable=%u"},
1432 	{Opt_init_itable, "init_itable"},
1433 	{Opt_noinit_itable, "noinit_itable"},
1434 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1435 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1436 	{Opt_nombcache, "nombcache"},
1437 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1438 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1439 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1440 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1441 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1442 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1443 	{Opt_err, NULL},
1444 };
1445 
1446 static ext4_fsblk_t get_sb_block(void **data)
1447 {
1448 	ext4_fsblk_t	sb_block;
1449 	char		*options = (char *) *data;
1450 
1451 	if (!options || strncmp(options, "sb=", 3) != 0)
1452 		return 1;	/* Default location */
1453 
1454 	options += 3;
1455 	/* TODO: use simple_strtoll with >32bit ext4 */
1456 	sb_block = simple_strtoul(options, &options, 0);
1457 	if (*options && *options != ',') {
1458 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1459 		       (char *) *data);
1460 		return 1;
1461 	}
1462 	if (*options == ',')
1463 		options++;
1464 	*data = (void *) options;
1465 
1466 	return sb_block;
1467 }
1468 
1469 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1470 static const char deprecated_msg[] =
1471 	"Mount option \"%s\" will be removed by %s\n"
1472 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1473 
1474 #ifdef CONFIG_QUOTA
1475 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1476 {
1477 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1478 	char *qname;
1479 	int ret = -1;
1480 
1481 	if (sb_any_quota_loaded(sb) &&
1482 		!sbi->s_qf_names[qtype]) {
1483 		ext4_msg(sb, KERN_ERR,
1484 			"Cannot change journaled "
1485 			"quota options when quota turned on");
1486 		return -1;
1487 	}
1488 	if (ext4_has_feature_quota(sb)) {
1489 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1490 			 "ignored when QUOTA feature is enabled");
1491 		return 1;
1492 	}
1493 	qname = match_strdup(args);
1494 	if (!qname) {
1495 		ext4_msg(sb, KERN_ERR,
1496 			"Not enough memory for storing quotafile name");
1497 		return -1;
1498 	}
1499 	if (sbi->s_qf_names[qtype]) {
1500 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1501 			ret = 1;
1502 		else
1503 			ext4_msg(sb, KERN_ERR,
1504 				 "%s quota file already specified",
1505 				 QTYPE2NAME(qtype));
1506 		goto errout;
1507 	}
1508 	if (strchr(qname, '/')) {
1509 		ext4_msg(sb, KERN_ERR,
1510 			"quotafile must be on filesystem root");
1511 		goto errout;
1512 	}
1513 	sbi->s_qf_names[qtype] = qname;
1514 	set_opt(sb, QUOTA);
1515 	return 1;
1516 errout:
1517 	kfree(qname);
1518 	return ret;
1519 }
1520 
1521 static int clear_qf_name(struct super_block *sb, int qtype)
1522 {
1523 
1524 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1525 
1526 	if (sb_any_quota_loaded(sb) &&
1527 		sbi->s_qf_names[qtype]) {
1528 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1529 			" when quota turned on");
1530 		return -1;
1531 	}
1532 	kfree(sbi->s_qf_names[qtype]);
1533 	sbi->s_qf_names[qtype] = NULL;
1534 	return 1;
1535 }
1536 #endif
1537 
1538 #define MOPT_SET	0x0001
1539 #define MOPT_CLEAR	0x0002
1540 #define MOPT_NOSUPPORT	0x0004
1541 #define MOPT_EXPLICIT	0x0008
1542 #define MOPT_CLEAR_ERR	0x0010
1543 #define MOPT_GTE0	0x0020
1544 #ifdef CONFIG_QUOTA
1545 #define MOPT_Q		0
1546 #define MOPT_QFMT	0x0040
1547 #else
1548 #define MOPT_Q		MOPT_NOSUPPORT
1549 #define MOPT_QFMT	MOPT_NOSUPPORT
1550 #endif
1551 #define MOPT_DATAJ	0x0080
1552 #define MOPT_NO_EXT2	0x0100
1553 #define MOPT_NO_EXT3	0x0200
1554 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1555 #define MOPT_STRING	0x0400
1556 
1557 static const struct mount_opts {
1558 	int	token;
1559 	int	mount_opt;
1560 	int	flags;
1561 } ext4_mount_opts[] = {
1562 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1563 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1564 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1565 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1566 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1567 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1568 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1569 	 MOPT_EXT4_ONLY | MOPT_SET},
1570 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1571 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1572 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1573 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1574 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1575 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1576 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1577 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1578 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1579 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1580 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1581 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1582 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1583 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1584 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1585 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1586 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1587 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1588 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1589 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1590 	 MOPT_NO_EXT2},
1591 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1592 	 MOPT_NO_EXT2},
1593 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1594 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1595 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1596 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1597 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1598 	{Opt_commit, 0, MOPT_GTE0},
1599 	{Opt_max_batch_time, 0, MOPT_GTE0},
1600 	{Opt_min_batch_time, 0, MOPT_GTE0},
1601 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1602 	{Opt_init_itable, 0, MOPT_GTE0},
1603 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1604 	{Opt_stripe, 0, MOPT_GTE0},
1605 	{Opt_resuid, 0, MOPT_GTE0},
1606 	{Opt_resgid, 0, MOPT_GTE0},
1607 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1608 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1609 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1610 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1611 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1612 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1613 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1614 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1615 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1616 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1617 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1618 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1619 #else
1620 	{Opt_acl, 0, MOPT_NOSUPPORT},
1621 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1622 #endif
1623 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1624 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1625 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1626 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1627 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1628 							MOPT_SET | MOPT_Q},
1629 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1630 							MOPT_SET | MOPT_Q},
1631 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1632 							MOPT_SET | MOPT_Q},
1633 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1634 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1635 							MOPT_CLEAR | MOPT_Q},
1636 	{Opt_usrjquota, 0, MOPT_Q},
1637 	{Opt_grpjquota, 0, MOPT_Q},
1638 	{Opt_offusrjquota, 0, MOPT_Q},
1639 	{Opt_offgrpjquota, 0, MOPT_Q},
1640 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1641 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1642 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1643 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1644 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1645 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1646 	{Opt_err, 0, 0}
1647 };
1648 
1649 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1650 			    substring_t *args, unsigned long *journal_devnum,
1651 			    unsigned int *journal_ioprio, int is_remount)
1652 {
1653 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1654 	const struct mount_opts *m;
1655 	kuid_t uid;
1656 	kgid_t gid;
1657 	int arg = 0;
1658 
1659 #ifdef CONFIG_QUOTA
1660 	if (token == Opt_usrjquota)
1661 		return set_qf_name(sb, USRQUOTA, &args[0]);
1662 	else if (token == Opt_grpjquota)
1663 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1664 	else if (token == Opt_offusrjquota)
1665 		return clear_qf_name(sb, USRQUOTA);
1666 	else if (token == Opt_offgrpjquota)
1667 		return clear_qf_name(sb, GRPQUOTA);
1668 #endif
1669 	switch (token) {
1670 	case Opt_noacl:
1671 	case Opt_nouser_xattr:
1672 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1673 		break;
1674 	case Opt_sb:
1675 		return 1;	/* handled by get_sb_block() */
1676 	case Opt_removed:
1677 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1678 		return 1;
1679 	case Opt_abort:
1680 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1681 		return 1;
1682 	case Opt_i_version:
1683 		sb->s_flags |= SB_I_VERSION;
1684 		return 1;
1685 	case Opt_lazytime:
1686 		sb->s_flags |= SB_LAZYTIME;
1687 		return 1;
1688 	case Opt_nolazytime:
1689 		sb->s_flags &= ~SB_LAZYTIME;
1690 		return 1;
1691 	}
1692 
1693 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1694 		if (token == m->token)
1695 			break;
1696 
1697 	if (m->token == Opt_err) {
1698 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1699 			 "or missing value", opt);
1700 		return -1;
1701 	}
1702 
1703 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1704 		ext4_msg(sb, KERN_ERR,
1705 			 "Mount option \"%s\" incompatible with ext2", opt);
1706 		return -1;
1707 	}
1708 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1709 		ext4_msg(sb, KERN_ERR,
1710 			 "Mount option \"%s\" incompatible with ext3", opt);
1711 		return -1;
1712 	}
1713 
1714 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1715 		return -1;
1716 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1717 		return -1;
1718 	if (m->flags & MOPT_EXPLICIT) {
1719 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1720 			set_opt2(sb, EXPLICIT_DELALLOC);
1721 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1722 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1723 		} else
1724 			return -1;
1725 	}
1726 	if (m->flags & MOPT_CLEAR_ERR)
1727 		clear_opt(sb, ERRORS_MASK);
1728 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1729 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1730 			 "options when quota turned on");
1731 		return -1;
1732 	}
1733 
1734 	if (m->flags & MOPT_NOSUPPORT) {
1735 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1736 	} else if (token == Opt_commit) {
1737 		if (arg == 0)
1738 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1739 		sbi->s_commit_interval = HZ * arg;
1740 	} else if (token == Opt_debug_want_extra_isize) {
1741 		sbi->s_want_extra_isize = arg;
1742 	} else if (token == Opt_max_batch_time) {
1743 		sbi->s_max_batch_time = arg;
1744 	} else if (token == Opt_min_batch_time) {
1745 		sbi->s_min_batch_time = arg;
1746 	} else if (token == Opt_inode_readahead_blks) {
1747 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1748 			ext4_msg(sb, KERN_ERR,
1749 				 "EXT4-fs: inode_readahead_blks must be "
1750 				 "0 or a power of 2 smaller than 2^31");
1751 			return -1;
1752 		}
1753 		sbi->s_inode_readahead_blks = arg;
1754 	} else if (token == Opt_init_itable) {
1755 		set_opt(sb, INIT_INODE_TABLE);
1756 		if (!args->from)
1757 			arg = EXT4_DEF_LI_WAIT_MULT;
1758 		sbi->s_li_wait_mult = arg;
1759 	} else if (token == Opt_max_dir_size_kb) {
1760 		sbi->s_max_dir_size_kb = arg;
1761 	} else if (token == Opt_stripe) {
1762 		sbi->s_stripe = arg;
1763 	} else if (token == Opt_resuid) {
1764 		uid = make_kuid(current_user_ns(), arg);
1765 		if (!uid_valid(uid)) {
1766 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1767 			return -1;
1768 		}
1769 		sbi->s_resuid = uid;
1770 	} else if (token == Opt_resgid) {
1771 		gid = make_kgid(current_user_ns(), arg);
1772 		if (!gid_valid(gid)) {
1773 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1774 			return -1;
1775 		}
1776 		sbi->s_resgid = gid;
1777 	} else if (token == Opt_journal_dev) {
1778 		if (is_remount) {
1779 			ext4_msg(sb, KERN_ERR,
1780 				 "Cannot specify journal on remount");
1781 			return -1;
1782 		}
1783 		*journal_devnum = arg;
1784 	} else if (token == Opt_journal_path) {
1785 		char *journal_path;
1786 		struct inode *journal_inode;
1787 		struct path path;
1788 		int error;
1789 
1790 		if (is_remount) {
1791 			ext4_msg(sb, KERN_ERR,
1792 				 "Cannot specify journal on remount");
1793 			return -1;
1794 		}
1795 		journal_path = match_strdup(&args[0]);
1796 		if (!journal_path) {
1797 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1798 				"journal device string");
1799 			return -1;
1800 		}
1801 
1802 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1803 		if (error) {
1804 			ext4_msg(sb, KERN_ERR, "error: could not find "
1805 				"journal device path: error %d", error);
1806 			kfree(journal_path);
1807 			return -1;
1808 		}
1809 
1810 		journal_inode = d_inode(path.dentry);
1811 		if (!S_ISBLK(journal_inode->i_mode)) {
1812 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1813 				"is not a block device", journal_path);
1814 			path_put(&path);
1815 			kfree(journal_path);
1816 			return -1;
1817 		}
1818 
1819 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1820 		path_put(&path);
1821 		kfree(journal_path);
1822 	} else if (token == Opt_journal_ioprio) {
1823 		if (arg > 7) {
1824 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1825 				 " (must be 0-7)");
1826 			return -1;
1827 		}
1828 		*journal_ioprio =
1829 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1830 	} else if (token == Opt_test_dummy_encryption) {
1831 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1832 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1833 		ext4_msg(sb, KERN_WARNING,
1834 			 "Test dummy encryption mode enabled");
1835 #else
1836 		ext4_msg(sb, KERN_WARNING,
1837 			 "Test dummy encryption mount option ignored");
1838 #endif
1839 	} else if (m->flags & MOPT_DATAJ) {
1840 		if (is_remount) {
1841 			if (!sbi->s_journal)
1842 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1843 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1844 				ext4_msg(sb, KERN_ERR,
1845 					 "Cannot change data mode on remount");
1846 				return -1;
1847 			}
1848 		} else {
1849 			clear_opt(sb, DATA_FLAGS);
1850 			sbi->s_mount_opt |= m->mount_opt;
1851 		}
1852 #ifdef CONFIG_QUOTA
1853 	} else if (m->flags & MOPT_QFMT) {
1854 		if (sb_any_quota_loaded(sb) &&
1855 		    sbi->s_jquota_fmt != m->mount_opt) {
1856 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1857 				 "quota options when quota turned on");
1858 			return -1;
1859 		}
1860 		if (ext4_has_feature_quota(sb)) {
1861 			ext4_msg(sb, KERN_INFO,
1862 				 "Quota format mount options ignored "
1863 				 "when QUOTA feature is enabled");
1864 			return 1;
1865 		}
1866 		sbi->s_jquota_fmt = m->mount_opt;
1867 #endif
1868 	} else if (token == Opt_dax) {
1869 #ifdef CONFIG_FS_DAX
1870 		ext4_msg(sb, KERN_WARNING,
1871 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1872 			sbi->s_mount_opt |= m->mount_opt;
1873 #else
1874 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1875 		return -1;
1876 #endif
1877 	} else if (token == Opt_data_err_abort) {
1878 		sbi->s_mount_opt |= m->mount_opt;
1879 	} else if (token == Opt_data_err_ignore) {
1880 		sbi->s_mount_opt &= ~m->mount_opt;
1881 	} else {
1882 		if (!args->from)
1883 			arg = 1;
1884 		if (m->flags & MOPT_CLEAR)
1885 			arg = !arg;
1886 		else if (unlikely(!(m->flags & MOPT_SET))) {
1887 			ext4_msg(sb, KERN_WARNING,
1888 				 "buggy handling of option %s", opt);
1889 			WARN_ON(1);
1890 			return -1;
1891 		}
1892 		if (arg != 0)
1893 			sbi->s_mount_opt |= m->mount_opt;
1894 		else
1895 			sbi->s_mount_opt &= ~m->mount_opt;
1896 	}
1897 	return 1;
1898 }
1899 
1900 static int parse_options(char *options, struct super_block *sb,
1901 			 unsigned long *journal_devnum,
1902 			 unsigned int *journal_ioprio,
1903 			 int is_remount)
1904 {
1905 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1906 	char *p;
1907 	substring_t args[MAX_OPT_ARGS];
1908 	int token;
1909 
1910 	if (!options)
1911 		return 1;
1912 
1913 	while ((p = strsep(&options, ",")) != NULL) {
1914 		if (!*p)
1915 			continue;
1916 		/*
1917 		 * Initialize args struct so we know whether arg was
1918 		 * found; some options take optional arguments.
1919 		 */
1920 		args[0].to = args[0].from = NULL;
1921 		token = match_token(p, tokens, args);
1922 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1923 				     journal_ioprio, is_remount) < 0)
1924 			return 0;
1925 	}
1926 #ifdef CONFIG_QUOTA
1927 	/*
1928 	 * We do the test below only for project quotas. 'usrquota' and
1929 	 * 'grpquota' mount options are allowed even without quota feature
1930 	 * to support legacy quotas in quota files.
1931 	 */
1932 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1933 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1934 			 "Cannot enable project quota enforcement.");
1935 		return 0;
1936 	}
1937 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1938 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1939 			clear_opt(sb, USRQUOTA);
1940 
1941 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1942 			clear_opt(sb, GRPQUOTA);
1943 
1944 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1945 			ext4_msg(sb, KERN_ERR, "old and new quota "
1946 					"format mixing");
1947 			return 0;
1948 		}
1949 
1950 		if (!sbi->s_jquota_fmt) {
1951 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1952 					"not specified");
1953 			return 0;
1954 		}
1955 	}
1956 #endif
1957 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1958 		int blocksize =
1959 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1960 
1961 		if (blocksize < PAGE_SIZE) {
1962 			ext4_msg(sb, KERN_ERR, "can't mount with "
1963 				 "dioread_nolock if block size != PAGE_SIZE");
1964 			return 0;
1965 		}
1966 	}
1967 	return 1;
1968 }
1969 
1970 static inline void ext4_show_quota_options(struct seq_file *seq,
1971 					   struct super_block *sb)
1972 {
1973 #if defined(CONFIG_QUOTA)
1974 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1975 
1976 	if (sbi->s_jquota_fmt) {
1977 		char *fmtname = "";
1978 
1979 		switch (sbi->s_jquota_fmt) {
1980 		case QFMT_VFS_OLD:
1981 			fmtname = "vfsold";
1982 			break;
1983 		case QFMT_VFS_V0:
1984 			fmtname = "vfsv0";
1985 			break;
1986 		case QFMT_VFS_V1:
1987 			fmtname = "vfsv1";
1988 			break;
1989 		}
1990 		seq_printf(seq, ",jqfmt=%s", fmtname);
1991 	}
1992 
1993 	if (sbi->s_qf_names[USRQUOTA])
1994 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1995 
1996 	if (sbi->s_qf_names[GRPQUOTA])
1997 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1998 #endif
1999 }
2000 
2001 static const char *token2str(int token)
2002 {
2003 	const struct match_token *t;
2004 
2005 	for (t = tokens; t->token != Opt_err; t++)
2006 		if (t->token == token && !strchr(t->pattern, '='))
2007 			break;
2008 	return t->pattern;
2009 }
2010 
2011 /*
2012  * Show an option if
2013  *  - it's set to a non-default value OR
2014  *  - if the per-sb default is different from the global default
2015  */
2016 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2017 			      int nodefs)
2018 {
2019 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2020 	struct ext4_super_block *es = sbi->s_es;
2021 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
2022 	const struct mount_opts *m;
2023 	char sep = nodefs ? '\n' : ',';
2024 
2025 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2026 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2027 
2028 	if (sbi->s_sb_block != 1)
2029 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2030 
2031 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2032 		int want_set = m->flags & MOPT_SET;
2033 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2034 		    (m->flags & MOPT_CLEAR_ERR))
2035 			continue;
2036 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2037 			continue; /* skip if same as the default */
2038 		if ((want_set &&
2039 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2040 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2041 			continue; /* select Opt_noFoo vs Opt_Foo */
2042 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2043 	}
2044 
2045 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2046 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2047 		SEQ_OPTS_PRINT("resuid=%u",
2048 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2049 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2050 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2051 		SEQ_OPTS_PRINT("resgid=%u",
2052 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2053 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2054 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2055 		SEQ_OPTS_PUTS("errors=remount-ro");
2056 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2057 		SEQ_OPTS_PUTS("errors=continue");
2058 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2059 		SEQ_OPTS_PUTS("errors=panic");
2060 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2061 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2062 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2063 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2064 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2065 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2066 	if (sb->s_flags & SB_I_VERSION)
2067 		SEQ_OPTS_PUTS("i_version");
2068 	if (nodefs || sbi->s_stripe)
2069 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2070 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2071 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2072 			SEQ_OPTS_PUTS("data=journal");
2073 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2074 			SEQ_OPTS_PUTS("data=ordered");
2075 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2076 			SEQ_OPTS_PUTS("data=writeback");
2077 	}
2078 	if (nodefs ||
2079 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2080 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2081 			       sbi->s_inode_readahead_blks);
2082 
2083 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2084 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2085 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2086 	if (nodefs || sbi->s_max_dir_size_kb)
2087 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2088 	if (test_opt(sb, DATA_ERR_ABORT))
2089 		SEQ_OPTS_PUTS("data_err=abort");
2090 
2091 	ext4_show_quota_options(seq, sb);
2092 	return 0;
2093 }
2094 
2095 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2096 {
2097 	return _ext4_show_options(seq, root->d_sb, 0);
2098 }
2099 
2100 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2101 {
2102 	struct super_block *sb = seq->private;
2103 	int rc;
2104 
2105 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2106 	rc = _ext4_show_options(seq, sb, 1);
2107 	seq_puts(seq, "\n");
2108 	return rc;
2109 }
2110 
2111 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2112 			    int read_only)
2113 {
2114 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2115 	int res = 0;
2116 
2117 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2118 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2119 			 "forcing read-only mode");
2120 		res = SB_RDONLY;
2121 	}
2122 	if (read_only)
2123 		goto done;
2124 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2125 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2126 			 "running e2fsck is recommended");
2127 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2128 		ext4_msg(sb, KERN_WARNING,
2129 			 "warning: mounting fs with errors, "
2130 			 "running e2fsck is recommended");
2131 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2132 		 le16_to_cpu(es->s_mnt_count) >=
2133 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2134 		ext4_msg(sb, KERN_WARNING,
2135 			 "warning: maximal mount count reached, "
2136 			 "running e2fsck is recommended");
2137 	else if (le32_to_cpu(es->s_checkinterval) &&
2138 		(le32_to_cpu(es->s_lastcheck) +
2139 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2140 		ext4_msg(sb, KERN_WARNING,
2141 			 "warning: checktime reached, "
2142 			 "running e2fsck is recommended");
2143 	if (!sbi->s_journal)
2144 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2145 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2146 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2147 	le16_add_cpu(&es->s_mnt_count, 1);
2148 	es->s_mtime = cpu_to_le32(get_seconds());
2149 	ext4_update_dynamic_rev(sb);
2150 	if (sbi->s_journal)
2151 		ext4_set_feature_journal_needs_recovery(sb);
2152 
2153 	ext4_commit_super(sb, 1);
2154 done:
2155 	if (test_opt(sb, DEBUG))
2156 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2157 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2158 			sb->s_blocksize,
2159 			sbi->s_groups_count,
2160 			EXT4_BLOCKS_PER_GROUP(sb),
2161 			EXT4_INODES_PER_GROUP(sb),
2162 			sbi->s_mount_opt, sbi->s_mount_opt2);
2163 
2164 	cleancache_init_fs(sb);
2165 	return res;
2166 }
2167 
2168 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2169 {
2170 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2171 	struct flex_groups *new_groups;
2172 	int size;
2173 
2174 	if (!sbi->s_log_groups_per_flex)
2175 		return 0;
2176 
2177 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2178 	if (size <= sbi->s_flex_groups_allocated)
2179 		return 0;
2180 
2181 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2182 	new_groups = kvzalloc(size, GFP_KERNEL);
2183 	if (!new_groups) {
2184 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2185 			 size / (int) sizeof(struct flex_groups));
2186 		return -ENOMEM;
2187 	}
2188 
2189 	if (sbi->s_flex_groups) {
2190 		memcpy(new_groups, sbi->s_flex_groups,
2191 		       (sbi->s_flex_groups_allocated *
2192 			sizeof(struct flex_groups)));
2193 		kvfree(sbi->s_flex_groups);
2194 	}
2195 	sbi->s_flex_groups = new_groups;
2196 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2197 	return 0;
2198 }
2199 
2200 static int ext4_fill_flex_info(struct super_block *sb)
2201 {
2202 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2203 	struct ext4_group_desc *gdp = NULL;
2204 	ext4_group_t flex_group;
2205 	int i, err;
2206 
2207 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2208 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2209 		sbi->s_log_groups_per_flex = 0;
2210 		return 1;
2211 	}
2212 
2213 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2214 	if (err)
2215 		goto failed;
2216 
2217 	for (i = 0; i < sbi->s_groups_count; i++) {
2218 		gdp = ext4_get_group_desc(sb, i, NULL);
2219 
2220 		flex_group = ext4_flex_group(sbi, i);
2221 		atomic_add(ext4_free_inodes_count(sb, gdp),
2222 			   &sbi->s_flex_groups[flex_group].free_inodes);
2223 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2224 			     &sbi->s_flex_groups[flex_group].free_clusters);
2225 		atomic_add(ext4_used_dirs_count(sb, gdp),
2226 			   &sbi->s_flex_groups[flex_group].used_dirs);
2227 	}
2228 
2229 	return 1;
2230 failed:
2231 	return 0;
2232 }
2233 
2234 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2235 				   struct ext4_group_desc *gdp)
2236 {
2237 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2238 	__u16 crc = 0;
2239 	__le32 le_group = cpu_to_le32(block_group);
2240 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2241 
2242 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2243 		/* Use new metadata_csum algorithm */
2244 		__u32 csum32;
2245 		__u16 dummy_csum = 0;
2246 
2247 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2248 				     sizeof(le_group));
2249 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2250 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2251 				     sizeof(dummy_csum));
2252 		offset += sizeof(dummy_csum);
2253 		if (offset < sbi->s_desc_size)
2254 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2255 					     sbi->s_desc_size - offset);
2256 
2257 		crc = csum32 & 0xFFFF;
2258 		goto out;
2259 	}
2260 
2261 	/* old crc16 code */
2262 	if (!ext4_has_feature_gdt_csum(sb))
2263 		return 0;
2264 
2265 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2266 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2267 	crc = crc16(crc, (__u8 *)gdp, offset);
2268 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2269 	/* for checksum of struct ext4_group_desc do the rest...*/
2270 	if (ext4_has_feature_64bit(sb) &&
2271 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2272 		crc = crc16(crc, (__u8 *)gdp + offset,
2273 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2274 				offset);
2275 
2276 out:
2277 	return cpu_to_le16(crc);
2278 }
2279 
2280 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2281 				struct ext4_group_desc *gdp)
2282 {
2283 	if (ext4_has_group_desc_csum(sb) &&
2284 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2285 		return 0;
2286 
2287 	return 1;
2288 }
2289 
2290 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2291 			      struct ext4_group_desc *gdp)
2292 {
2293 	if (!ext4_has_group_desc_csum(sb))
2294 		return;
2295 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2296 }
2297 
2298 /* Called at mount-time, super-block is locked */
2299 static int ext4_check_descriptors(struct super_block *sb,
2300 				  ext4_fsblk_t sb_block,
2301 				  ext4_group_t *first_not_zeroed)
2302 {
2303 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2304 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2305 	ext4_fsblk_t last_block;
2306 	ext4_fsblk_t block_bitmap;
2307 	ext4_fsblk_t inode_bitmap;
2308 	ext4_fsblk_t inode_table;
2309 	int flexbg_flag = 0;
2310 	ext4_group_t i, grp = sbi->s_groups_count;
2311 
2312 	if (ext4_has_feature_flex_bg(sb))
2313 		flexbg_flag = 1;
2314 
2315 	ext4_debug("Checking group descriptors");
2316 
2317 	for (i = 0; i < sbi->s_groups_count; i++) {
2318 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2319 
2320 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2321 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2322 		else
2323 			last_block = first_block +
2324 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2325 
2326 		if ((grp == sbi->s_groups_count) &&
2327 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2328 			grp = i;
2329 
2330 		block_bitmap = ext4_block_bitmap(sb, gdp);
2331 		if (block_bitmap == sb_block) {
2332 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2333 				 "Block bitmap for group %u overlaps "
2334 				 "superblock", i);
2335 		}
2336 		if (block_bitmap < first_block || block_bitmap > last_block) {
2337 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2338 			       "Block bitmap for group %u not in group "
2339 			       "(block %llu)!", i, block_bitmap);
2340 			return 0;
2341 		}
2342 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2343 		if (inode_bitmap == sb_block) {
2344 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2345 				 "Inode bitmap for group %u overlaps "
2346 				 "superblock", i);
2347 		}
2348 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2349 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2350 			       "Inode bitmap for group %u not in group "
2351 			       "(block %llu)!", i, inode_bitmap);
2352 			return 0;
2353 		}
2354 		inode_table = ext4_inode_table(sb, gdp);
2355 		if (inode_table == sb_block) {
2356 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2357 				 "Inode table for group %u overlaps "
2358 				 "superblock", i);
2359 		}
2360 		if (inode_table < first_block ||
2361 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2362 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2363 			       "Inode table for group %u not in group "
2364 			       "(block %llu)!", i, inode_table);
2365 			return 0;
2366 		}
2367 		ext4_lock_group(sb, i);
2368 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2369 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2370 				 "Checksum for group %u failed (%u!=%u)",
2371 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2372 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2373 			if (!sb_rdonly(sb)) {
2374 				ext4_unlock_group(sb, i);
2375 				return 0;
2376 			}
2377 		}
2378 		ext4_unlock_group(sb, i);
2379 		if (!flexbg_flag)
2380 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2381 	}
2382 	if (NULL != first_not_zeroed)
2383 		*first_not_zeroed = grp;
2384 	return 1;
2385 }
2386 
2387 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2388  * the superblock) which were deleted from all directories, but held open by
2389  * a process at the time of a crash.  We walk the list and try to delete these
2390  * inodes at recovery time (only with a read-write filesystem).
2391  *
2392  * In order to keep the orphan inode chain consistent during traversal (in
2393  * case of crash during recovery), we link each inode into the superblock
2394  * orphan list_head and handle it the same way as an inode deletion during
2395  * normal operation (which journals the operations for us).
2396  *
2397  * We only do an iget() and an iput() on each inode, which is very safe if we
2398  * accidentally point at an in-use or already deleted inode.  The worst that
2399  * can happen in this case is that we get a "bit already cleared" message from
2400  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2401  * e2fsck was run on this filesystem, and it must have already done the orphan
2402  * inode cleanup for us, so we can safely abort without any further action.
2403  */
2404 static void ext4_orphan_cleanup(struct super_block *sb,
2405 				struct ext4_super_block *es)
2406 {
2407 	unsigned int s_flags = sb->s_flags;
2408 	int ret, nr_orphans = 0, nr_truncates = 0;
2409 #ifdef CONFIG_QUOTA
2410 	int quota_update = 0;
2411 	int i;
2412 #endif
2413 	if (!es->s_last_orphan) {
2414 		jbd_debug(4, "no orphan inodes to clean up\n");
2415 		return;
2416 	}
2417 
2418 	if (bdev_read_only(sb->s_bdev)) {
2419 		ext4_msg(sb, KERN_ERR, "write access "
2420 			"unavailable, skipping orphan cleanup");
2421 		return;
2422 	}
2423 
2424 	/* Check if feature set would not allow a r/w mount */
2425 	if (!ext4_feature_set_ok(sb, 0)) {
2426 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2427 			 "unknown ROCOMPAT features");
2428 		return;
2429 	}
2430 
2431 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2432 		/* don't clear list on RO mount w/ errors */
2433 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2434 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2435 				  "clearing orphan list.\n");
2436 			es->s_last_orphan = 0;
2437 		}
2438 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2439 		return;
2440 	}
2441 
2442 	if (s_flags & SB_RDONLY) {
2443 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2444 		sb->s_flags &= ~SB_RDONLY;
2445 	}
2446 #ifdef CONFIG_QUOTA
2447 	/* Needed for iput() to work correctly and not trash data */
2448 	sb->s_flags |= SB_ACTIVE;
2449 
2450 	/*
2451 	 * Turn on quotas which were not enabled for read-only mounts if
2452 	 * filesystem has quota feature, so that they are updated correctly.
2453 	 */
2454 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2455 		int ret = ext4_enable_quotas(sb);
2456 
2457 		if (!ret)
2458 			quota_update = 1;
2459 		else
2460 			ext4_msg(sb, KERN_ERR,
2461 				"Cannot turn on quotas: error %d", ret);
2462 	}
2463 
2464 	/* Turn on journaled quotas used for old sytle */
2465 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2466 		if (EXT4_SB(sb)->s_qf_names[i]) {
2467 			int ret = ext4_quota_on_mount(sb, i);
2468 
2469 			if (!ret)
2470 				quota_update = 1;
2471 			else
2472 				ext4_msg(sb, KERN_ERR,
2473 					"Cannot turn on journaled "
2474 					"quota: type %d: error %d", i, ret);
2475 		}
2476 	}
2477 #endif
2478 
2479 	while (es->s_last_orphan) {
2480 		struct inode *inode;
2481 
2482 		/*
2483 		 * We may have encountered an error during cleanup; if
2484 		 * so, skip the rest.
2485 		 */
2486 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2487 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2488 			es->s_last_orphan = 0;
2489 			break;
2490 		}
2491 
2492 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2493 		if (IS_ERR(inode)) {
2494 			es->s_last_orphan = 0;
2495 			break;
2496 		}
2497 
2498 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2499 		dquot_initialize(inode);
2500 		if (inode->i_nlink) {
2501 			if (test_opt(sb, DEBUG))
2502 				ext4_msg(sb, KERN_DEBUG,
2503 					"%s: truncating inode %lu to %lld bytes",
2504 					__func__, inode->i_ino, inode->i_size);
2505 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2506 				  inode->i_ino, inode->i_size);
2507 			inode_lock(inode);
2508 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2509 			ret = ext4_truncate(inode);
2510 			if (ret)
2511 				ext4_std_error(inode->i_sb, ret);
2512 			inode_unlock(inode);
2513 			nr_truncates++;
2514 		} else {
2515 			if (test_opt(sb, DEBUG))
2516 				ext4_msg(sb, KERN_DEBUG,
2517 					"%s: deleting unreferenced inode %lu",
2518 					__func__, inode->i_ino);
2519 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2520 				  inode->i_ino);
2521 			nr_orphans++;
2522 		}
2523 		iput(inode);  /* The delete magic happens here! */
2524 	}
2525 
2526 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2527 
2528 	if (nr_orphans)
2529 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2530 		       PLURAL(nr_orphans));
2531 	if (nr_truncates)
2532 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2533 		       PLURAL(nr_truncates));
2534 #ifdef CONFIG_QUOTA
2535 	/* Turn off quotas if they were enabled for orphan cleanup */
2536 	if (quota_update) {
2537 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2538 			if (sb_dqopt(sb)->files[i])
2539 				dquot_quota_off(sb, i);
2540 		}
2541 	}
2542 #endif
2543 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2544 }
2545 
2546 /*
2547  * Maximal extent format file size.
2548  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2549  * extent format containers, within a sector_t, and within i_blocks
2550  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2551  * so that won't be a limiting factor.
2552  *
2553  * However there is other limiting factor. We do store extents in the form
2554  * of starting block and length, hence the resulting length of the extent
2555  * covering maximum file size must fit into on-disk format containers as
2556  * well. Given that length is always by 1 unit bigger than max unit (because
2557  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2558  *
2559  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2560  */
2561 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2562 {
2563 	loff_t res;
2564 	loff_t upper_limit = MAX_LFS_FILESIZE;
2565 
2566 	/* small i_blocks in vfs inode? */
2567 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2568 		/*
2569 		 * CONFIG_LBDAF is not enabled implies the inode
2570 		 * i_block represent total blocks in 512 bytes
2571 		 * 32 == size of vfs inode i_blocks * 8
2572 		 */
2573 		upper_limit = (1LL << 32) - 1;
2574 
2575 		/* total blocks in file system block size */
2576 		upper_limit >>= (blkbits - 9);
2577 		upper_limit <<= blkbits;
2578 	}
2579 
2580 	/*
2581 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2582 	 * by one fs block, so ee_len can cover the extent of maximum file
2583 	 * size
2584 	 */
2585 	res = (1LL << 32) - 1;
2586 	res <<= blkbits;
2587 
2588 	/* Sanity check against vm- & vfs- imposed limits */
2589 	if (res > upper_limit)
2590 		res = upper_limit;
2591 
2592 	return res;
2593 }
2594 
2595 /*
2596  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2597  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2598  * We need to be 1 filesystem block less than the 2^48 sector limit.
2599  */
2600 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2601 {
2602 	loff_t res = EXT4_NDIR_BLOCKS;
2603 	int meta_blocks;
2604 	loff_t upper_limit;
2605 	/* This is calculated to be the largest file size for a dense, block
2606 	 * mapped file such that the file's total number of 512-byte sectors,
2607 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2608 	 *
2609 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2610 	 * number of 512-byte sectors of the file.
2611 	 */
2612 
2613 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2614 		/*
2615 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2616 		 * the inode i_block field represents total file blocks in
2617 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2618 		 */
2619 		upper_limit = (1LL << 32) - 1;
2620 
2621 		/* total blocks in file system block size */
2622 		upper_limit >>= (bits - 9);
2623 
2624 	} else {
2625 		/*
2626 		 * We use 48 bit ext4_inode i_blocks
2627 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2628 		 * represent total number of blocks in
2629 		 * file system block size
2630 		 */
2631 		upper_limit = (1LL << 48) - 1;
2632 
2633 	}
2634 
2635 	/* indirect blocks */
2636 	meta_blocks = 1;
2637 	/* double indirect blocks */
2638 	meta_blocks += 1 + (1LL << (bits-2));
2639 	/* tripple indirect blocks */
2640 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2641 
2642 	upper_limit -= meta_blocks;
2643 	upper_limit <<= bits;
2644 
2645 	res += 1LL << (bits-2);
2646 	res += 1LL << (2*(bits-2));
2647 	res += 1LL << (3*(bits-2));
2648 	res <<= bits;
2649 	if (res > upper_limit)
2650 		res = upper_limit;
2651 
2652 	if (res > MAX_LFS_FILESIZE)
2653 		res = MAX_LFS_FILESIZE;
2654 
2655 	return res;
2656 }
2657 
2658 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2659 				   ext4_fsblk_t logical_sb_block, int nr)
2660 {
2661 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2662 	ext4_group_t bg, first_meta_bg;
2663 	int has_super = 0;
2664 
2665 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2666 
2667 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2668 		return logical_sb_block + nr + 1;
2669 	bg = sbi->s_desc_per_block * nr;
2670 	if (ext4_bg_has_super(sb, bg))
2671 		has_super = 1;
2672 
2673 	/*
2674 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2675 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2676 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2677 	 * compensate.
2678 	 */
2679 	if (sb->s_blocksize == 1024 && nr == 0 &&
2680 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2681 		has_super++;
2682 
2683 	return (has_super + ext4_group_first_block_no(sb, bg));
2684 }
2685 
2686 /**
2687  * ext4_get_stripe_size: Get the stripe size.
2688  * @sbi: In memory super block info
2689  *
2690  * If we have specified it via mount option, then
2691  * use the mount option value. If the value specified at mount time is
2692  * greater than the blocks per group use the super block value.
2693  * If the super block value is greater than blocks per group return 0.
2694  * Allocator needs it be less than blocks per group.
2695  *
2696  */
2697 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2698 {
2699 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2700 	unsigned long stripe_width =
2701 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2702 	int ret;
2703 
2704 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2705 		ret = sbi->s_stripe;
2706 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2707 		ret = stripe_width;
2708 	else if (stride && stride <= sbi->s_blocks_per_group)
2709 		ret = stride;
2710 	else
2711 		ret = 0;
2712 
2713 	/*
2714 	 * If the stripe width is 1, this makes no sense and
2715 	 * we set it to 0 to turn off stripe handling code.
2716 	 */
2717 	if (ret <= 1)
2718 		ret = 0;
2719 
2720 	return ret;
2721 }
2722 
2723 /*
2724  * Check whether this filesystem can be mounted based on
2725  * the features present and the RDONLY/RDWR mount requested.
2726  * Returns 1 if this filesystem can be mounted as requested,
2727  * 0 if it cannot be.
2728  */
2729 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2730 {
2731 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2732 		ext4_msg(sb, KERN_ERR,
2733 			"Couldn't mount because of "
2734 			"unsupported optional features (%x)",
2735 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2736 			~EXT4_FEATURE_INCOMPAT_SUPP));
2737 		return 0;
2738 	}
2739 
2740 	if (readonly)
2741 		return 1;
2742 
2743 	if (ext4_has_feature_readonly(sb)) {
2744 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2745 		sb->s_flags |= SB_RDONLY;
2746 		return 1;
2747 	}
2748 
2749 	/* Check that feature set is OK for a read-write mount */
2750 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2751 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2752 			 "unsupported optional features (%x)",
2753 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2754 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2755 		return 0;
2756 	}
2757 	/*
2758 	 * Large file size enabled file system can only be mounted
2759 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2760 	 */
2761 	if (ext4_has_feature_huge_file(sb)) {
2762 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2763 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2764 				 "cannot be mounted RDWR without "
2765 				 "CONFIG_LBDAF");
2766 			return 0;
2767 		}
2768 	}
2769 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2770 		ext4_msg(sb, KERN_ERR,
2771 			 "Can't support bigalloc feature without "
2772 			 "extents feature\n");
2773 		return 0;
2774 	}
2775 
2776 #ifndef CONFIG_QUOTA
2777 	if (ext4_has_feature_quota(sb) && !readonly) {
2778 		ext4_msg(sb, KERN_ERR,
2779 			 "Filesystem with quota feature cannot be mounted RDWR "
2780 			 "without CONFIG_QUOTA");
2781 		return 0;
2782 	}
2783 	if (ext4_has_feature_project(sb) && !readonly) {
2784 		ext4_msg(sb, KERN_ERR,
2785 			 "Filesystem with project quota feature cannot be mounted RDWR "
2786 			 "without CONFIG_QUOTA");
2787 		return 0;
2788 	}
2789 #endif  /* CONFIG_QUOTA */
2790 	return 1;
2791 }
2792 
2793 /*
2794  * This function is called once a day if we have errors logged
2795  * on the file system
2796  */
2797 static void print_daily_error_info(struct timer_list *t)
2798 {
2799 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2800 	struct super_block *sb = sbi->s_sb;
2801 	struct ext4_super_block *es = sbi->s_es;
2802 
2803 	if (es->s_error_count)
2804 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2805 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2806 			 le32_to_cpu(es->s_error_count));
2807 	if (es->s_first_error_time) {
2808 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2809 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2810 		       (int) sizeof(es->s_first_error_func),
2811 		       es->s_first_error_func,
2812 		       le32_to_cpu(es->s_first_error_line));
2813 		if (es->s_first_error_ino)
2814 			printk(KERN_CONT ": inode %u",
2815 			       le32_to_cpu(es->s_first_error_ino));
2816 		if (es->s_first_error_block)
2817 			printk(KERN_CONT ": block %llu", (unsigned long long)
2818 			       le64_to_cpu(es->s_first_error_block));
2819 		printk(KERN_CONT "\n");
2820 	}
2821 	if (es->s_last_error_time) {
2822 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2823 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2824 		       (int) sizeof(es->s_last_error_func),
2825 		       es->s_last_error_func,
2826 		       le32_to_cpu(es->s_last_error_line));
2827 		if (es->s_last_error_ino)
2828 			printk(KERN_CONT ": inode %u",
2829 			       le32_to_cpu(es->s_last_error_ino));
2830 		if (es->s_last_error_block)
2831 			printk(KERN_CONT ": block %llu", (unsigned long long)
2832 			       le64_to_cpu(es->s_last_error_block));
2833 		printk(KERN_CONT "\n");
2834 	}
2835 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2836 }
2837 
2838 /* Find next suitable group and run ext4_init_inode_table */
2839 static int ext4_run_li_request(struct ext4_li_request *elr)
2840 {
2841 	struct ext4_group_desc *gdp = NULL;
2842 	ext4_group_t group, ngroups;
2843 	struct super_block *sb;
2844 	unsigned long timeout = 0;
2845 	int ret = 0;
2846 
2847 	sb = elr->lr_super;
2848 	ngroups = EXT4_SB(sb)->s_groups_count;
2849 
2850 	for (group = elr->lr_next_group; group < ngroups; group++) {
2851 		gdp = ext4_get_group_desc(sb, group, NULL);
2852 		if (!gdp) {
2853 			ret = 1;
2854 			break;
2855 		}
2856 
2857 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2858 			break;
2859 	}
2860 
2861 	if (group >= ngroups)
2862 		ret = 1;
2863 
2864 	if (!ret) {
2865 		timeout = jiffies;
2866 		ret = ext4_init_inode_table(sb, group,
2867 					    elr->lr_timeout ? 0 : 1);
2868 		if (elr->lr_timeout == 0) {
2869 			timeout = (jiffies - timeout) *
2870 				  elr->lr_sbi->s_li_wait_mult;
2871 			elr->lr_timeout = timeout;
2872 		}
2873 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2874 		elr->lr_next_group = group + 1;
2875 	}
2876 	return ret;
2877 }
2878 
2879 /*
2880  * Remove lr_request from the list_request and free the
2881  * request structure. Should be called with li_list_mtx held
2882  */
2883 static void ext4_remove_li_request(struct ext4_li_request *elr)
2884 {
2885 	struct ext4_sb_info *sbi;
2886 
2887 	if (!elr)
2888 		return;
2889 
2890 	sbi = elr->lr_sbi;
2891 
2892 	list_del(&elr->lr_request);
2893 	sbi->s_li_request = NULL;
2894 	kfree(elr);
2895 }
2896 
2897 static void ext4_unregister_li_request(struct super_block *sb)
2898 {
2899 	mutex_lock(&ext4_li_mtx);
2900 	if (!ext4_li_info) {
2901 		mutex_unlock(&ext4_li_mtx);
2902 		return;
2903 	}
2904 
2905 	mutex_lock(&ext4_li_info->li_list_mtx);
2906 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2907 	mutex_unlock(&ext4_li_info->li_list_mtx);
2908 	mutex_unlock(&ext4_li_mtx);
2909 }
2910 
2911 static struct task_struct *ext4_lazyinit_task;
2912 
2913 /*
2914  * This is the function where ext4lazyinit thread lives. It walks
2915  * through the request list searching for next scheduled filesystem.
2916  * When such a fs is found, run the lazy initialization request
2917  * (ext4_rn_li_request) and keep track of the time spend in this
2918  * function. Based on that time we compute next schedule time of
2919  * the request. When walking through the list is complete, compute
2920  * next waking time and put itself into sleep.
2921  */
2922 static int ext4_lazyinit_thread(void *arg)
2923 {
2924 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2925 	struct list_head *pos, *n;
2926 	struct ext4_li_request *elr;
2927 	unsigned long next_wakeup, cur;
2928 
2929 	BUG_ON(NULL == eli);
2930 
2931 cont_thread:
2932 	while (true) {
2933 		next_wakeup = MAX_JIFFY_OFFSET;
2934 
2935 		mutex_lock(&eli->li_list_mtx);
2936 		if (list_empty(&eli->li_request_list)) {
2937 			mutex_unlock(&eli->li_list_mtx);
2938 			goto exit_thread;
2939 		}
2940 		list_for_each_safe(pos, n, &eli->li_request_list) {
2941 			int err = 0;
2942 			int progress = 0;
2943 			elr = list_entry(pos, struct ext4_li_request,
2944 					 lr_request);
2945 
2946 			if (time_before(jiffies, elr->lr_next_sched)) {
2947 				if (time_before(elr->lr_next_sched, next_wakeup))
2948 					next_wakeup = elr->lr_next_sched;
2949 				continue;
2950 			}
2951 			if (down_read_trylock(&elr->lr_super->s_umount)) {
2952 				if (sb_start_write_trylock(elr->lr_super)) {
2953 					progress = 1;
2954 					/*
2955 					 * We hold sb->s_umount, sb can not
2956 					 * be removed from the list, it is
2957 					 * now safe to drop li_list_mtx
2958 					 */
2959 					mutex_unlock(&eli->li_list_mtx);
2960 					err = ext4_run_li_request(elr);
2961 					sb_end_write(elr->lr_super);
2962 					mutex_lock(&eli->li_list_mtx);
2963 					n = pos->next;
2964 				}
2965 				up_read((&elr->lr_super->s_umount));
2966 			}
2967 			/* error, remove the lazy_init job */
2968 			if (err) {
2969 				ext4_remove_li_request(elr);
2970 				continue;
2971 			}
2972 			if (!progress) {
2973 				elr->lr_next_sched = jiffies +
2974 					(prandom_u32()
2975 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2976 			}
2977 			if (time_before(elr->lr_next_sched, next_wakeup))
2978 				next_wakeup = elr->lr_next_sched;
2979 		}
2980 		mutex_unlock(&eli->li_list_mtx);
2981 
2982 		try_to_freeze();
2983 
2984 		cur = jiffies;
2985 		if ((time_after_eq(cur, next_wakeup)) ||
2986 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2987 			cond_resched();
2988 			continue;
2989 		}
2990 
2991 		schedule_timeout_interruptible(next_wakeup - cur);
2992 
2993 		if (kthread_should_stop()) {
2994 			ext4_clear_request_list();
2995 			goto exit_thread;
2996 		}
2997 	}
2998 
2999 exit_thread:
3000 	/*
3001 	 * It looks like the request list is empty, but we need
3002 	 * to check it under the li_list_mtx lock, to prevent any
3003 	 * additions into it, and of course we should lock ext4_li_mtx
3004 	 * to atomically free the list and ext4_li_info, because at
3005 	 * this point another ext4 filesystem could be registering
3006 	 * new one.
3007 	 */
3008 	mutex_lock(&ext4_li_mtx);
3009 	mutex_lock(&eli->li_list_mtx);
3010 	if (!list_empty(&eli->li_request_list)) {
3011 		mutex_unlock(&eli->li_list_mtx);
3012 		mutex_unlock(&ext4_li_mtx);
3013 		goto cont_thread;
3014 	}
3015 	mutex_unlock(&eli->li_list_mtx);
3016 	kfree(ext4_li_info);
3017 	ext4_li_info = NULL;
3018 	mutex_unlock(&ext4_li_mtx);
3019 
3020 	return 0;
3021 }
3022 
3023 static void ext4_clear_request_list(void)
3024 {
3025 	struct list_head *pos, *n;
3026 	struct ext4_li_request *elr;
3027 
3028 	mutex_lock(&ext4_li_info->li_list_mtx);
3029 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3030 		elr = list_entry(pos, struct ext4_li_request,
3031 				 lr_request);
3032 		ext4_remove_li_request(elr);
3033 	}
3034 	mutex_unlock(&ext4_li_info->li_list_mtx);
3035 }
3036 
3037 static int ext4_run_lazyinit_thread(void)
3038 {
3039 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3040 					 ext4_li_info, "ext4lazyinit");
3041 	if (IS_ERR(ext4_lazyinit_task)) {
3042 		int err = PTR_ERR(ext4_lazyinit_task);
3043 		ext4_clear_request_list();
3044 		kfree(ext4_li_info);
3045 		ext4_li_info = NULL;
3046 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3047 				 "initialization thread\n",
3048 				 err);
3049 		return err;
3050 	}
3051 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3052 	return 0;
3053 }
3054 
3055 /*
3056  * Check whether it make sense to run itable init. thread or not.
3057  * If there is at least one uninitialized inode table, return
3058  * corresponding group number, else the loop goes through all
3059  * groups and return total number of groups.
3060  */
3061 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3062 {
3063 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3064 	struct ext4_group_desc *gdp = NULL;
3065 
3066 	for (group = 0; group < ngroups; group++) {
3067 		gdp = ext4_get_group_desc(sb, group, NULL);
3068 		if (!gdp)
3069 			continue;
3070 
3071 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3072 			break;
3073 	}
3074 
3075 	return group;
3076 }
3077 
3078 static int ext4_li_info_new(void)
3079 {
3080 	struct ext4_lazy_init *eli = NULL;
3081 
3082 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3083 	if (!eli)
3084 		return -ENOMEM;
3085 
3086 	INIT_LIST_HEAD(&eli->li_request_list);
3087 	mutex_init(&eli->li_list_mtx);
3088 
3089 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3090 
3091 	ext4_li_info = eli;
3092 
3093 	return 0;
3094 }
3095 
3096 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3097 					    ext4_group_t start)
3098 {
3099 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3100 	struct ext4_li_request *elr;
3101 
3102 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3103 	if (!elr)
3104 		return NULL;
3105 
3106 	elr->lr_super = sb;
3107 	elr->lr_sbi = sbi;
3108 	elr->lr_next_group = start;
3109 
3110 	/*
3111 	 * Randomize first schedule time of the request to
3112 	 * spread the inode table initialization requests
3113 	 * better.
3114 	 */
3115 	elr->lr_next_sched = jiffies + (prandom_u32() %
3116 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3117 	return elr;
3118 }
3119 
3120 int ext4_register_li_request(struct super_block *sb,
3121 			     ext4_group_t first_not_zeroed)
3122 {
3123 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3124 	struct ext4_li_request *elr = NULL;
3125 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3126 	int ret = 0;
3127 
3128 	mutex_lock(&ext4_li_mtx);
3129 	if (sbi->s_li_request != NULL) {
3130 		/*
3131 		 * Reset timeout so it can be computed again, because
3132 		 * s_li_wait_mult might have changed.
3133 		 */
3134 		sbi->s_li_request->lr_timeout = 0;
3135 		goto out;
3136 	}
3137 
3138 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3139 	    !test_opt(sb, INIT_INODE_TABLE))
3140 		goto out;
3141 
3142 	elr = ext4_li_request_new(sb, first_not_zeroed);
3143 	if (!elr) {
3144 		ret = -ENOMEM;
3145 		goto out;
3146 	}
3147 
3148 	if (NULL == ext4_li_info) {
3149 		ret = ext4_li_info_new();
3150 		if (ret)
3151 			goto out;
3152 	}
3153 
3154 	mutex_lock(&ext4_li_info->li_list_mtx);
3155 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3156 	mutex_unlock(&ext4_li_info->li_list_mtx);
3157 
3158 	sbi->s_li_request = elr;
3159 	/*
3160 	 * set elr to NULL here since it has been inserted to
3161 	 * the request_list and the removal and free of it is
3162 	 * handled by ext4_clear_request_list from now on.
3163 	 */
3164 	elr = NULL;
3165 
3166 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3167 		ret = ext4_run_lazyinit_thread();
3168 		if (ret)
3169 			goto out;
3170 	}
3171 out:
3172 	mutex_unlock(&ext4_li_mtx);
3173 	if (ret)
3174 		kfree(elr);
3175 	return ret;
3176 }
3177 
3178 /*
3179  * We do not need to lock anything since this is called on
3180  * module unload.
3181  */
3182 static void ext4_destroy_lazyinit_thread(void)
3183 {
3184 	/*
3185 	 * If thread exited earlier
3186 	 * there's nothing to be done.
3187 	 */
3188 	if (!ext4_li_info || !ext4_lazyinit_task)
3189 		return;
3190 
3191 	kthread_stop(ext4_lazyinit_task);
3192 }
3193 
3194 static int set_journal_csum_feature_set(struct super_block *sb)
3195 {
3196 	int ret = 1;
3197 	int compat, incompat;
3198 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3199 
3200 	if (ext4_has_metadata_csum(sb)) {
3201 		/* journal checksum v3 */
3202 		compat = 0;
3203 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3204 	} else {
3205 		/* journal checksum v1 */
3206 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3207 		incompat = 0;
3208 	}
3209 
3210 	jbd2_journal_clear_features(sbi->s_journal,
3211 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3212 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3213 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3214 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3215 		ret = jbd2_journal_set_features(sbi->s_journal,
3216 				compat, 0,
3217 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3218 				incompat);
3219 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3220 		ret = jbd2_journal_set_features(sbi->s_journal,
3221 				compat, 0,
3222 				incompat);
3223 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3224 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3225 	} else {
3226 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3227 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3228 	}
3229 
3230 	return ret;
3231 }
3232 
3233 /*
3234  * Note: calculating the overhead so we can be compatible with
3235  * historical BSD practice is quite difficult in the face of
3236  * clusters/bigalloc.  This is because multiple metadata blocks from
3237  * different block group can end up in the same allocation cluster.
3238  * Calculating the exact overhead in the face of clustered allocation
3239  * requires either O(all block bitmaps) in memory or O(number of block
3240  * groups**2) in time.  We will still calculate the superblock for
3241  * older file systems --- and if we come across with a bigalloc file
3242  * system with zero in s_overhead_clusters the estimate will be close to
3243  * correct especially for very large cluster sizes --- but for newer
3244  * file systems, it's better to calculate this figure once at mkfs
3245  * time, and store it in the superblock.  If the superblock value is
3246  * present (even for non-bigalloc file systems), we will use it.
3247  */
3248 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3249 			  char *buf)
3250 {
3251 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3252 	struct ext4_group_desc	*gdp;
3253 	ext4_fsblk_t		first_block, last_block, b;
3254 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3255 	int			s, j, count = 0;
3256 
3257 	if (!ext4_has_feature_bigalloc(sb))
3258 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3259 			sbi->s_itb_per_group + 2);
3260 
3261 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3262 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3263 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3264 	for (i = 0; i < ngroups; i++) {
3265 		gdp = ext4_get_group_desc(sb, i, NULL);
3266 		b = ext4_block_bitmap(sb, gdp);
3267 		if (b >= first_block && b <= last_block) {
3268 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3269 			count++;
3270 		}
3271 		b = ext4_inode_bitmap(sb, gdp);
3272 		if (b >= first_block && b <= last_block) {
3273 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3274 			count++;
3275 		}
3276 		b = ext4_inode_table(sb, gdp);
3277 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3278 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3279 				int c = EXT4_B2C(sbi, b - first_block);
3280 				ext4_set_bit(c, buf);
3281 				count++;
3282 			}
3283 		if (i != grp)
3284 			continue;
3285 		s = 0;
3286 		if (ext4_bg_has_super(sb, grp)) {
3287 			ext4_set_bit(s++, buf);
3288 			count++;
3289 		}
3290 		j = ext4_bg_num_gdb(sb, grp);
3291 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3292 			ext4_error(sb, "Invalid number of block group "
3293 				   "descriptor blocks: %d", j);
3294 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3295 		}
3296 		count += j;
3297 		for (; j > 0; j--)
3298 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3299 	}
3300 	if (!count)
3301 		return 0;
3302 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3303 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3304 }
3305 
3306 /*
3307  * Compute the overhead and stash it in sbi->s_overhead
3308  */
3309 int ext4_calculate_overhead(struct super_block *sb)
3310 {
3311 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3312 	struct ext4_super_block *es = sbi->s_es;
3313 	struct inode *j_inode;
3314 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3315 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3316 	ext4_fsblk_t overhead = 0;
3317 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3318 
3319 	if (!buf)
3320 		return -ENOMEM;
3321 
3322 	/*
3323 	 * Compute the overhead (FS structures).  This is constant
3324 	 * for a given filesystem unless the number of block groups
3325 	 * changes so we cache the previous value until it does.
3326 	 */
3327 
3328 	/*
3329 	 * All of the blocks before first_data_block are overhead
3330 	 */
3331 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3332 
3333 	/*
3334 	 * Add the overhead found in each block group
3335 	 */
3336 	for (i = 0; i < ngroups; i++) {
3337 		int blks;
3338 
3339 		blks = count_overhead(sb, i, buf);
3340 		overhead += blks;
3341 		if (blks)
3342 			memset(buf, 0, PAGE_SIZE);
3343 		cond_resched();
3344 	}
3345 
3346 	/*
3347 	 * Add the internal journal blocks whether the journal has been
3348 	 * loaded or not
3349 	 */
3350 	if (sbi->s_journal && !sbi->journal_bdev)
3351 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3352 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3353 		j_inode = ext4_get_journal_inode(sb, j_inum);
3354 		if (j_inode) {
3355 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3356 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3357 			iput(j_inode);
3358 		} else {
3359 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3360 		}
3361 	}
3362 	sbi->s_overhead = overhead;
3363 	smp_wmb();
3364 	free_page((unsigned long) buf);
3365 	return 0;
3366 }
3367 
3368 static void ext4_set_resv_clusters(struct super_block *sb)
3369 {
3370 	ext4_fsblk_t resv_clusters;
3371 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3372 
3373 	/*
3374 	 * There's no need to reserve anything when we aren't using extents.
3375 	 * The space estimates are exact, there are no unwritten extents,
3376 	 * hole punching doesn't need new metadata... This is needed especially
3377 	 * to keep ext2/3 backward compatibility.
3378 	 */
3379 	if (!ext4_has_feature_extents(sb))
3380 		return;
3381 	/*
3382 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3383 	 * This should cover the situations where we can not afford to run
3384 	 * out of space like for example punch hole, or converting
3385 	 * unwritten extents in delalloc path. In most cases such
3386 	 * allocation would require 1, or 2 blocks, higher numbers are
3387 	 * very rare.
3388 	 */
3389 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3390 			 sbi->s_cluster_bits);
3391 
3392 	do_div(resv_clusters, 50);
3393 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3394 
3395 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3396 }
3397 
3398 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3399 {
3400 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3401 	char *orig_data = kstrdup(data, GFP_KERNEL);
3402 	struct buffer_head *bh;
3403 	struct ext4_super_block *es = NULL;
3404 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3405 	ext4_fsblk_t block;
3406 	ext4_fsblk_t sb_block = get_sb_block(&data);
3407 	ext4_fsblk_t logical_sb_block;
3408 	unsigned long offset = 0;
3409 	unsigned long journal_devnum = 0;
3410 	unsigned long def_mount_opts;
3411 	struct inode *root;
3412 	const char *descr;
3413 	int ret = -ENOMEM;
3414 	int blocksize, clustersize;
3415 	unsigned int db_count;
3416 	unsigned int i;
3417 	int needs_recovery, has_huge_files, has_bigalloc;
3418 	__u64 blocks_count;
3419 	int err = 0;
3420 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3421 	ext4_group_t first_not_zeroed;
3422 
3423 	if ((data && !orig_data) || !sbi)
3424 		goto out_free_base;
3425 
3426 	sbi->s_daxdev = dax_dev;
3427 	sbi->s_blockgroup_lock =
3428 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3429 	if (!sbi->s_blockgroup_lock)
3430 		goto out_free_base;
3431 
3432 	sb->s_fs_info = sbi;
3433 	sbi->s_sb = sb;
3434 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3435 	sbi->s_sb_block = sb_block;
3436 	if (sb->s_bdev->bd_part)
3437 		sbi->s_sectors_written_start =
3438 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3439 
3440 	/* Cleanup superblock name */
3441 	strreplace(sb->s_id, '/', '!');
3442 
3443 	/* -EINVAL is default */
3444 	ret = -EINVAL;
3445 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3446 	if (!blocksize) {
3447 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3448 		goto out_fail;
3449 	}
3450 
3451 	/*
3452 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3453 	 * block sizes.  We need to calculate the offset from buffer start.
3454 	 */
3455 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3456 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3457 		offset = do_div(logical_sb_block, blocksize);
3458 	} else {
3459 		logical_sb_block = sb_block;
3460 	}
3461 
3462 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3463 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3464 		goto out_fail;
3465 	}
3466 	/*
3467 	 * Note: s_es must be initialized as soon as possible because
3468 	 *       some ext4 macro-instructions depend on its value
3469 	 */
3470 	es = (struct ext4_super_block *) (bh->b_data + offset);
3471 	sbi->s_es = es;
3472 	sb->s_magic = le16_to_cpu(es->s_magic);
3473 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3474 		goto cantfind_ext4;
3475 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3476 
3477 	/* Warn if metadata_csum and gdt_csum are both set. */
3478 	if (ext4_has_feature_metadata_csum(sb) &&
3479 	    ext4_has_feature_gdt_csum(sb))
3480 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3481 			     "redundant flags; please run fsck.");
3482 
3483 	/* Check for a known checksum algorithm */
3484 	if (!ext4_verify_csum_type(sb, es)) {
3485 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3486 			 "unknown checksum algorithm.");
3487 		silent = 1;
3488 		goto cantfind_ext4;
3489 	}
3490 
3491 	/* Load the checksum driver */
3492 	if (ext4_has_feature_metadata_csum(sb) ||
3493 	    ext4_has_feature_ea_inode(sb)) {
3494 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3495 		if (IS_ERR(sbi->s_chksum_driver)) {
3496 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3497 			ret = PTR_ERR(sbi->s_chksum_driver);
3498 			sbi->s_chksum_driver = NULL;
3499 			goto failed_mount;
3500 		}
3501 	}
3502 
3503 	/* Check superblock checksum */
3504 	if (!ext4_superblock_csum_verify(sb, es)) {
3505 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3506 			 "invalid superblock checksum.  Run e2fsck?");
3507 		silent = 1;
3508 		ret = -EFSBADCRC;
3509 		goto cantfind_ext4;
3510 	}
3511 
3512 	/* Precompute checksum seed for all metadata */
3513 	if (ext4_has_feature_csum_seed(sb))
3514 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3515 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3516 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3517 					       sizeof(es->s_uuid));
3518 
3519 	/* Set defaults before we parse the mount options */
3520 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3521 	set_opt(sb, INIT_INODE_TABLE);
3522 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3523 		set_opt(sb, DEBUG);
3524 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3525 		set_opt(sb, GRPID);
3526 	if (def_mount_opts & EXT4_DEFM_UID16)
3527 		set_opt(sb, NO_UID32);
3528 	/* xattr user namespace & acls are now defaulted on */
3529 	set_opt(sb, XATTR_USER);
3530 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3531 	set_opt(sb, POSIX_ACL);
3532 #endif
3533 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3534 	if (ext4_has_metadata_csum(sb))
3535 		set_opt(sb, JOURNAL_CHECKSUM);
3536 
3537 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3538 		set_opt(sb, JOURNAL_DATA);
3539 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3540 		set_opt(sb, ORDERED_DATA);
3541 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3542 		set_opt(sb, WRITEBACK_DATA);
3543 
3544 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3545 		set_opt(sb, ERRORS_PANIC);
3546 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3547 		set_opt(sb, ERRORS_CONT);
3548 	else
3549 		set_opt(sb, ERRORS_RO);
3550 	/* block_validity enabled by default; disable with noblock_validity */
3551 	set_opt(sb, BLOCK_VALIDITY);
3552 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3553 		set_opt(sb, DISCARD);
3554 
3555 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3556 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3557 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3558 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3559 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3560 
3561 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3562 		set_opt(sb, BARRIER);
3563 
3564 	/*
3565 	 * enable delayed allocation by default
3566 	 * Use -o nodelalloc to turn it off
3567 	 */
3568 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3569 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3570 		set_opt(sb, DELALLOC);
3571 
3572 	/*
3573 	 * set default s_li_wait_mult for lazyinit, for the case there is
3574 	 * no mount option specified.
3575 	 */
3576 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3577 
3578 	if (sbi->s_es->s_mount_opts[0]) {
3579 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3580 					      sizeof(sbi->s_es->s_mount_opts),
3581 					      GFP_KERNEL);
3582 		if (!s_mount_opts)
3583 			goto failed_mount;
3584 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3585 				   &journal_ioprio, 0)) {
3586 			ext4_msg(sb, KERN_WARNING,
3587 				 "failed to parse options in superblock: %s",
3588 				 s_mount_opts);
3589 		}
3590 		kfree(s_mount_opts);
3591 	}
3592 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3593 	if (!parse_options((char *) data, sb, &journal_devnum,
3594 			   &journal_ioprio, 0))
3595 		goto failed_mount;
3596 
3597 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3598 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3599 			    "with data=journal disables delayed "
3600 			    "allocation and O_DIRECT support!\n");
3601 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3602 			ext4_msg(sb, KERN_ERR, "can't mount with "
3603 				 "both data=journal and delalloc");
3604 			goto failed_mount;
3605 		}
3606 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3607 			ext4_msg(sb, KERN_ERR, "can't mount with "
3608 				 "both data=journal and dioread_nolock");
3609 			goto failed_mount;
3610 		}
3611 		if (test_opt(sb, DAX)) {
3612 			ext4_msg(sb, KERN_ERR, "can't mount with "
3613 				 "both data=journal and dax");
3614 			goto failed_mount;
3615 		}
3616 		if (ext4_has_feature_encrypt(sb)) {
3617 			ext4_msg(sb, KERN_WARNING,
3618 				 "encrypted files will use data=ordered "
3619 				 "instead of data journaling mode");
3620 		}
3621 		if (test_opt(sb, DELALLOC))
3622 			clear_opt(sb, DELALLOC);
3623 	} else {
3624 		sb->s_iflags |= SB_I_CGROUPWB;
3625 	}
3626 
3627 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3628 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3629 
3630 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3631 	    (ext4_has_compat_features(sb) ||
3632 	     ext4_has_ro_compat_features(sb) ||
3633 	     ext4_has_incompat_features(sb)))
3634 		ext4_msg(sb, KERN_WARNING,
3635 		       "feature flags set on rev 0 fs, "
3636 		       "running e2fsck is recommended");
3637 
3638 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3639 		set_opt2(sb, HURD_COMPAT);
3640 		if (ext4_has_feature_64bit(sb)) {
3641 			ext4_msg(sb, KERN_ERR,
3642 				 "The Hurd can't support 64-bit file systems");
3643 			goto failed_mount;
3644 		}
3645 
3646 		/*
3647 		 * ea_inode feature uses l_i_version field which is not
3648 		 * available in HURD_COMPAT mode.
3649 		 */
3650 		if (ext4_has_feature_ea_inode(sb)) {
3651 			ext4_msg(sb, KERN_ERR,
3652 				 "ea_inode feature is not supported for Hurd");
3653 			goto failed_mount;
3654 		}
3655 	}
3656 
3657 	if (IS_EXT2_SB(sb)) {
3658 		if (ext2_feature_set_ok(sb))
3659 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3660 				 "using the ext4 subsystem");
3661 		else {
3662 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3663 				 "to feature incompatibilities");
3664 			goto failed_mount;
3665 		}
3666 	}
3667 
3668 	if (IS_EXT3_SB(sb)) {
3669 		if (ext3_feature_set_ok(sb))
3670 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3671 				 "using the ext4 subsystem");
3672 		else {
3673 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3674 				 "to feature incompatibilities");
3675 			goto failed_mount;
3676 		}
3677 	}
3678 
3679 	/*
3680 	 * Check feature flags regardless of the revision level, since we
3681 	 * previously didn't change the revision level when setting the flags,
3682 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3683 	 */
3684 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3685 		goto failed_mount;
3686 
3687 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3688 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3689 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3690 		ext4_msg(sb, KERN_ERR,
3691 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3692 			 blocksize, le32_to_cpu(es->s_log_block_size));
3693 		goto failed_mount;
3694 	}
3695 	if (le32_to_cpu(es->s_log_block_size) >
3696 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3697 		ext4_msg(sb, KERN_ERR,
3698 			 "Invalid log block size: %u",
3699 			 le32_to_cpu(es->s_log_block_size));
3700 		goto failed_mount;
3701 	}
3702 
3703 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3704 		ext4_msg(sb, KERN_ERR,
3705 			 "Number of reserved GDT blocks insanely large: %d",
3706 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3707 		goto failed_mount;
3708 	}
3709 
3710 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3711 		if (ext4_has_feature_inline_data(sb)) {
3712 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3713 					" that may contain inline data");
3714 			goto failed_mount;
3715 		}
3716 		err = bdev_dax_supported(sb, blocksize);
3717 		if (err)
3718 			goto failed_mount;
3719 	}
3720 
3721 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3722 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3723 			 es->s_encryption_level);
3724 		goto failed_mount;
3725 	}
3726 
3727 	if (sb->s_blocksize != blocksize) {
3728 		/* Validate the filesystem blocksize */
3729 		if (!sb_set_blocksize(sb, blocksize)) {
3730 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3731 					blocksize);
3732 			goto failed_mount;
3733 		}
3734 
3735 		brelse(bh);
3736 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3737 		offset = do_div(logical_sb_block, blocksize);
3738 		bh = sb_bread_unmovable(sb, logical_sb_block);
3739 		if (!bh) {
3740 			ext4_msg(sb, KERN_ERR,
3741 			       "Can't read superblock on 2nd try");
3742 			goto failed_mount;
3743 		}
3744 		es = (struct ext4_super_block *)(bh->b_data + offset);
3745 		sbi->s_es = es;
3746 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3747 			ext4_msg(sb, KERN_ERR,
3748 			       "Magic mismatch, very weird!");
3749 			goto failed_mount;
3750 		}
3751 	}
3752 
3753 	has_huge_files = ext4_has_feature_huge_file(sb);
3754 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3755 						      has_huge_files);
3756 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3757 
3758 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3759 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3760 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3761 	} else {
3762 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3763 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3764 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3765 		    (!is_power_of_2(sbi->s_inode_size)) ||
3766 		    (sbi->s_inode_size > blocksize)) {
3767 			ext4_msg(sb, KERN_ERR,
3768 			       "unsupported inode size: %d",
3769 			       sbi->s_inode_size);
3770 			goto failed_mount;
3771 		}
3772 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3773 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3774 	}
3775 
3776 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3777 	if (ext4_has_feature_64bit(sb)) {
3778 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3779 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3780 		    !is_power_of_2(sbi->s_desc_size)) {
3781 			ext4_msg(sb, KERN_ERR,
3782 			       "unsupported descriptor size %lu",
3783 			       sbi->s_desc_size);
3784 			goto failed_mount;
3785 		}
3786 	} else
3787 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3788 
3789 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3790 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3791 
3792 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3793 	if (sbi->s_inodes_per_block == 0)
3794 		goto cantfind_ext4;
3795 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3796 	    sbi->s_inodes_per_group > blocksize * 8) {
3797 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3798 			 sbi->s_blocks_per_group);
3799 		goto failed_mount;
3800 	}
3801 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3802 					sbi->s_inodes_per_block;
3803 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3804 	sbi->s_sbh = bh;
3805 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3806 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3807 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3808 
3809 	for (i = 0; i < 4; i++)
3810 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3811 	sbi->s_def_hash_version = es->s_def_hash_version;
3812 	if (ext4_has_feature_dir_index(sb)) {
3813 		i = le32_to_cpu(es->s_flags);
3814 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3815 			sbi->s_hash_unsigned = 3;
3816 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3817 #ifdef __CHAR_UNSIGNED__
3818 			if (!sb_rdonly(sb))
3819 				es->s_flags |=
3820 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3821 			sbi->s_hash_unsigned = 3;
3822 #else
3823 			if (!sb_rdonly(sb))
3824 				es->s_flags |=
3825 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3826 #endif
3827 		}
3828 	}
3829 
3830 	/* Handle clustersize */
3831 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3832 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3833 	if (has_bigalloc) {
3834 		if (clustersize < blocksize) {
3835 			ext4_msg(sb, KERN_ERR,
3836 				 "cluster size (%d) smaller than "
3837 				 "block size (%d)", clustersize, blocksize);
3838 			goto failed_mount;
3839 		}
3840 		if (le32_to_cpu(es->s_log_cluster_size) >
3841 		    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3842 			ext4_msg(sb, KERN_ERR,
3843 				 "Invalid log cluster size: %u",
3844 				 le32_to_cpu(es->s_log_cluster_size));
3845 			goto failed_mount;
3846 		}
3847 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3848 			le32_to_cpu(es->s_log_block_size);
3849 		sbi->s_clusters_per_group =
3850 			le32_to_cpu(es->s_clusters_per_group);
3851 		if (sbi->s_clusters_per_group > blocksize * 8) {
3852 			ext4_msg(sb, KERN_ERR,
3853 				 "#clusters per group too big: %lu",
3854 				 sbi->s_clusters_per_group);
3855 			goto failed_mount;
3856 		}
3857 		if (sbi->s_blocks_per_group !=
3858 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3859 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3860 				 "clusters per group (%lu) inconsistent",
3861 				 sbi->s_blocks_per_group,
3862 				 sbi->s_clusters_per_group);
3863 			goto failed_mount;
3864 		}
3865 	} else {
3866 		if (clustersize != blocksize) {
3867 			ext4_warning(sb, "fragment/cluster size (%d) != "
3868 				     "block size (%d)", clustersize,
3869 				     blocksize);
3870 			clustersize = blocksize;
3871 		}
3872 		if (sbi->s_blocks_per_group > blocksize * 8) {
3873 			ext4_msg(sb, KERN_ERR,
3874 				 "#blocks per group too big: %lu",
3875 				 sbi->s_blocks_per_group);
3876 			goto failed_mount;
3877 		}
3878 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3879 		sbi->s_cluster_bits = 0;
3880 	}
3881 	sbi->s_cluster_ratio = clustersize / blocksize;
3882 
3883 	/* Do we have standard group size of clustersize * 8 blocks ? */
3884 	if (sbi->s_blocks_per_group == clustersize << 3)
3885 		set_opt2(sb, STD_GROUP_SIZE);
3886 
3887 	/*
3888 	 * Test whether we have more sectors than will fit in sector_t,
3889 	 * and whether the max offset is addressable by the page cache.
3890 	 */
3891 	err = generic_check_addressable(sb->s_blocksize_bits,
3892 					ext4_blocks_count(es));
3893 	if (err) {
3894 		ext4_msg(sb, KERN_ERR, "filesystem"
3895 			 " too large to mount safely on this system");
3896 		if (sizeof(sector_t) < 8)
3897 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3898 		goto failed_mount;
3899 	}
3900 
3901 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3902 		goto cantfind_ext4;
3903 
3904 	/* check blocks count against device size */
3905 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3906 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3907 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3908 		       "exceeds size of device (%llu blocks)",
3909 		       ext4_blocks_count(es), blocks_count);
3910 		goto failed_mount;
3911 	}
3912 
3913 	/*
3914 	 * It makes no sense for the first data block to be beyond the end
3915 	 * of the filesystem.
3916 	 */
3917 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3918 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3919 			 "block %u is beyond end of filesystem (%llu)",
3920 			 le32_to_cpu(es->s_first_data_block),
3921 			 ext4_blocks_count(es));
3922 		goto failed_mount;
3923 	}
3924 	blocks_count = (ext4_blocks_count(es) -
3925 			le32_to_cpu(es->s_first_data_block) +
3926 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3927 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3928 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3929 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3930 		       "(block count %llu, first data block %u, "
3931 		       "blocks per group %lu)", sbi->s_groups_count,
3932 		       ext4_blocks_count(es),
3933 		       le32_to_cpu(es->s_first_data_block),
3934 		       EXT4_BLOCKS_PER_GROUP(sb));
3935 		goto failed_mount;
3936 	}
3937 	sbi->s_groups_count = blocks_count;
3938 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3939 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3940 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3941 		   EXT4_DESC_PER_BLOCK(sb);
3942 	if (ext4_has_feature_meta_bg(sb)) {
3943 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3944 			ext4_msg(sb, KERN_WARNING,
3945 				 "first meta block group too large: %u "
3946 				 "(group descriptor block count %u)",
3947 				 le32_to_cpu(es->s_first_meta_bg), db_count);
3948 			goto failed_mount;
3949 		}
3950 	}
3951 	sbi->s_group_desc = kvmalloc(db_count *
3952 					  sizeof(struct buffer_head *),
3953 					  GFP_KERNEL);
3954 	if (sbi->s_group_desc == NULL) {
3955 		ext4_msg(sb, KERN_ERR, "not enough memory");
3956 		ret = -ENOMEM;
3957 		goto failed_mount;
3958 	}
3959 
3960 	bgl_lock_init(sbi->s_blockgroup_lock);
3961 
3962 	/* Pre-read the descriptors into the buffer cache */
3963 	for (i = 0; i < db_count; i++) {
3964 		block = descriptor_loc(sb, logical_sb_block, i);
3965 		sb_breadahead(sb, block);
3966 	}
3967 
3968 	for (i = 0; i < db_count; i++) {
3969 		block = descriptor_loc(sb, logical_sb_block, i);
3970 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3971 		if (!sbi->s_group_desc[i]) {
3972 			ext4_msg(sb, KERN_ERR,
3973 			       "can't read group descriptor %d", i);
3974 			db_count = i;
3975 			goto failed_mount2;
3976 		}
3977 	}
3978 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3979 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3980 		ret = -EFSCORRUPTED;
3981 		goto failed_mount2;
3982 	}
3983 
3984 	sbi->s_gdb_count = db_count;
3985 
3986 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
3987 
3988 	/* Register extent status tree shrinker */
3989 	if (ext4_es_register_shrinker(sbi))
3990 		goto failed_mount3;
3991 
3992 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3993 	sbi->s_extent_max_zeroout_kb = 32;
3994 
3995 	/*
3996 	 * set up enough so that it can read an inode
3997 	 */
3998 	sb->s_op = &ext4_sops;
3999 	sb->s_export_op = &ext4_export_ops;
4000 	sb->s_xattr = ext4_xattr_handlers;
4001 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4002 	sb->s_cop = &ext4_cryptops;
4003 #endif
4004 #ifdef CONFIG_QUOTA
4005 	sb->dq_op = &ext4_quota_operations;
4006 	if (ext4_has_feature_quota(sb))
4007 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4008 	else
4009 		sb->s_qcop = &ext4_qctl_operations;
4010 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4011 #endif
4012 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4013 
4014 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4015 	mutex_init(&sbi->s_orphan_lock);
4016 
4017 	sb->s_root = NULL;
4018 
4019 	needs_recovery = (es->s_last_orphan != 0 ||
4020 			  ext4_has_feature_journal_needs_recovery(sb));
4021 
4022 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4023 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4024 			goto failed_mount3a;
4025 
4026 	/*
4027 	 * The first inode we look at is the journal inode.  Don't try
4028 	 * root first: it may be modified in the journal!
4029 	 */
4030 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4031 		err = ext4_load_journal(sb, es, journal_devnum);
4032 		if (err)
4033 			goto failed_mount3a;
4034 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4035 		   ext4_has_feature_journal_needs_recovery(sb)) {
4036 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4037 		       "suppressed and not mounted read-only");
4038 		goto failed_mount_wq;
4039 	} else {
4040 		/* Nojournal mode, all journal mount options are illegal */
4041 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4042 			ext4_msg(sb, KERN_ERR, "can't mount with "
4043 				 "journal_checksum, fs mounted w/o journal");
4044 			goto failed_mount_wq;
4045 		}
4046 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4047 			ext4_msg(sb, KERN_ERR, "can't mount with "
4048 				 "journal_async_commit, fs mounted w/o journal");
4049 			goto failed_mount_wq;
4050 		}
4051 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4052 			ext4_msg(sb, KERN_ERR, "can't mount with "
4053 				 "commit=%lu, fs mounted w/o journal",
4054 				 sbi->s_commit_interval / HZ);
4055 			goto failed_mount_wq;
4056 		}
4057 		if (EXT4_MOUNT_DATA_FLAGS &
4058 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4059 			ext4_msg(sb, KERN_ERR, "can't mount with "
4060 				 "data=, fs mounted w/o journal");
4061 			goto failed_mount_wq;
4062 		}
4063 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4064 		clear_opt(sb, JOURNAL_CHECKSUM);
4065 		clear_opt(sb, DATA_FLAGS);
4066 		sbi->s_journal = NULL;
4067 		needs_recovery = 0;
4068 		goto no_journal;
4069 	}
4070 
4071 	if (ext4_has_feature_64bit(sb) &&
4072 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4073 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4074 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4075 		goto failed_mount_wq;
4076 	}
4077 
4078 	if (!set_journal_csum_feature_set(sb)) {
4079 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4080 			 "feature set");
4081 		goto failed_mount_wq;
4082 	}
4083 
4084 	/* We have now updated the journal if required, so we can
4085 	 * validate the data journaling mode. */
4086 	switch (test_opt(sb, DATA_FLAGS)) {
4087 	case 0:
4088 		/* No mode set, assume a default based on the journal
4089 		 * capabilities: ORDERED_DATA if the journal can
4090 		 * cope, else JOURNAL_DATA
4091 		 */
4092 		if (jbd2_journal_check_available_features
4093 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4094 			set_opt(sb, ORDERED_DATA);
4095 		else
4096 			set_opt(sb, JOURNAL_DATA);
4097 		break;
4098 
4099 	case EXT4_MOUNT_ORDERED_DATA:
4100 	case EXT4_MOUNT_WRITEBACK_DATA:
4101 		if (!jbd2_journal_check_available_features
4102 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4103 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4104 			       "requested data journaling mode");
4105 			goto failed_mount_wq;
4106 		}
4107 	default:
4108 		break;
4109 	}
4110 
4111 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4112 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4113 		ext4_msg(sb, KERN_ERR, "can't mount with "
4114 			"journal_async_commit in data=ordered mode");
4115 		goto failed_mount_wq;
4116 	}
4117 
4118 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4119 
4120 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4121 
4122 no_journal:
4123 	if (!test_opt(sb, NO_MBCACHE)) {
4124 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4125 		if (!sbi->s_ea_block_cache) {
4126 			ext4_msg(sb, KERN_ERR,
4127 				 "Failed to create ea_block_cache");
4128 			goto failed_mount_wq;
4129 		}
4130 
4131 		if (ext4_has_feature_ea_inode(sb)) {
4132 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4133 			if (!sbi->s_ea_inode_cache) {
4134 				ext4_msg(sb, KERN_ERR,
4135 					 "Failed to create ea_inode_cache");
4136 				goto failed_mount_wq;
4137 			}
4138 		}
4139 	}
4140 
4141 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4142 	    (blocksize != PAGE_SIZE)) {
4143 		ext4_msg(sb, KERN_ERR,
4144 			 "Unsupported blocksize for fs encryption");
4145 		goto failed_mount_wq;
4146 	}
4147 
4148 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4149 	    !ext4_has_feature_encrypt(sb)) {
4150 		ext4_set_feature_encrypt(sb);
4151 		ext4_commit_super(sb, 1);
4152 	}
4153 
4154 	/*
4155 	 * Get the # of file system overhead blocks from the
4156 	 * superblock if present.
4157 	 */
4158 	if (es->s_overhead_clusters)
4159 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4160 	else {
4161 		err = ext4_calculate_overhead(sb);
4162 		if (err)
4163 			goto failed_mount_wq;
4164 	}
4165 
4166 	/*
4167 	 * The maximum number of concurrent works can be high and
4168 	 * concurrency isn't really necessary.  Limit it to 1.
4169 	 */
4170 	EXT4_SB(sb)->rsv_conversion_wq =
4171 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4172 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4173 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4174 		ret = -ENOMEM;
4175 		goto failed_mount4;
4176 	}
4177 
4178 	/*
4179 	 * The jbd2_journal_load will have done any necessary log recovery,
4180 	 * so we can safely mount the rest of the filesystem now.
4181 	 */
4182 
4183 	root = ext4_iget(sb, EXT4_ROOT_INO);
4184 	if (IS_ERR(root)) {
4185 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4186 		ret = PTR_ERR(root);
4187 		root = NULL;
4188 		goto failed_mount4;
4189 	}
4190 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4191 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4192 		iput(root);
4193 		goto failed_mount4;
4194 	}
4195 	sb->s_root = d_make_root(root);
4196 	if (!sb->s_root) {
4197 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4198 		ret = -ENOMEM;
4199 		goto failed_mount4;
4200 	}
4201 
4202 	if (ext4_setup_super(sb, es, sb_rdonly(sb)))
4203 		sb->s_flags |= SB_RDONLY;
4204 
4205 	/* determine the minimum size of new large inodes, if present */
4206 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4207 	    sbi->s_want_extra_isize == 0) {
4208 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4209 						     EXT4_GOOD_OLD_INODE_SIZE;
4210 		if (ext4_has_feature_extra_isize(sb)) {
4211 			if (sbi->s_want_extra_isize <
4212 			    le16_to_cpu(es->s_want_extra_isize))
4213 				sbi->s_want_extra_isize =
4214 					le16_to_cpu(es->s_want_extra_isize);
4215 			if (sbi->s_want_extra_isize <
4216 			    le16_to_cpu(es->s_min_extra_isize))
4217 				sbi->s_want_extra_isize =
4218 					le16_to_cpu(es->s_min_extra_isize);
4219 		}
4220 	}
4221 	/* Check if enough inode space is available */
4222 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4223 							sbi->s_inode_size) {
4224 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4225 						       EXT4_GOOD_OLD_INODE_SIZE;
4226 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4227 			 "available");
4228 	}
4229 
4230 	ext4_set_resv_clusters(sb);
4231 
4232 	err = ext4_setup_system_zone(sb);
4233 	if (err) {
4234 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4235 			 "zone (%d)", err);
4236 		goto failed_mount4a;
4237 	}
4238 
4239 	ext4_ext_init(sb);
4240 	err = ext4_mb_init(sb);
4241 	if (err) {
4242 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4243 			 err);
4244 		goto failed_mount5;
4245 	}
4246 
4247 	block = ext4_count_free_clusters(sb);
4248 	ext4_free_blocks_count_set(sbi->s_es,
4249 				   EXT4_C2B(sbi, block));
4250 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4251 				  GFP_KERNEL);
4252 	if (!err) {
4253 		unsigned long freei = ext4_count_free_inodes(sb);
4254 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4255 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4256 					  GFP_KERNEL);
4257 	}
4258 	if (!err)
4259 		err = percpu_counter_init(&sbi->s_dirs_counter,
4260 					  ext4_count_dirs(sb), GFP_KERNEL);
4261 	if (!err)
4262 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4263 					  GFP_KERNEL);
4264 	if (!err)
4265 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4266 
4267 	if (err) {
4268 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4269 		goto failed_mount6;
4270 	}
4271 
4272 	if (ext4_has_feature_flex_bg(sb))
4273 		if (!ext4_fill_flex_info(sb)) {
4274 			ext4_msg(sb, KERN_ERR,
4275 			       "unable to initialize "
4276 			       "flex_bg meta info!");
4277 			goto failed_mount6;
4278 		}
4279 
4280 	err = ext4_register_li_request(sb, first_not_zeroed);
4281 	if (err)
4282 		goto failed_mount6;
4283 
4284 	err = ext4_register_sysfs(sb);
4285 	if (err)
4286 		goto failed_mount7;
4287 
4288 #ifdef CONFIG_QUOTA
4289 	/* Enable quota usage during mount. */
4290 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4291 		err = ext4_enable_quotas(sb);
4292 		if (err)
4293 			goto failed_mount8;
4294 	}
4295 #endif  /* CONFIG_QUOTA */
4296 
4297 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4298 	ext4_orphan_cleanup(sb, es);
4299 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4300 	if (needs_recovery) {
4301 		ext4_msg(sb, KERN_INFO, "recovery complete");
4302 		ext4_mark_recovery_complete(sb, es);
4303 	}
4304 	if (EXT4_SB(sb)->s_journal) {
4305 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4306 			descr = " journalled data mode";
4307 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4308 			descr = " ordered data mode";
4309 		else
4310 			descr = " writeback data mode";
4311 	} else
4312 		descr = "out journal";
4313 
4314 	if (test_opt(sb, DISCARD)) {
4315 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4316 		if (!blk_queue_discard(q))
4317 			ext4_msg(sb, KERN_WARNING,
4318 				 "mounting with \"discard\" option, but "
4319 				 "the device does not support discard");
4320 	}
4321 
4322 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4323 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4324 			 "Opts: %.*s%s%s", descr,
4325 			 (int) sizeof(sbi->s_es->s_mount_opts),
4326 			 sbi->s_es->s_mount_opts,
4327 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4328 
4329 	if (es->s_error_count)
4330 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4331 
4332 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4333 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4334 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4335 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4336 
4337 	kfree(orig_data);
4338 	return 0;
4339 
4340 cantfind_ext4:
4341 	if (!silent)
4342 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4343 	goto failed_mount;
4344 
4345 #ifdef CONFIG_QUOTA
4346 failed_mount8:
4347 	ext4_unregister_sysfs(sb);
4348 #endif
4349 failed_mount7:
4350 	ext4_unregister_li_request(sb);
4351 failed_mount6:
4352 	ext4_mb_release(sb);
4353 	if (sbi->s_flex_groups)
4354 		kvfree(sbi->s_flex_groups);
4355 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4356 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4357 	percpu_counter_destroy(&sbi->s_dirs_counter);
4358 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4359 failed_mount5:
4360 	ext4_ext_release(sb);
4361 	ext4_release_system_zone(sb);
4362 failed_mount4a:
4363 	dput(sb->s_root);
4364 	sb->s_root = NULL;
4365 failed_mount4:
4366 	ext4_msg(sb, KERN_ERR, "mount failed");
4367 	if (EXT4_SB(sb)->rsv_conversion_wq)
4368 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4369 failed_mount_wq:
4370 	if (sbi->s_ea_inode_cache) {
4371 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4372 		sbi->s_ea_inode_cache = NULL;
4373 	}
4374 	if (sbi->s_ea_block_cache) {
4375 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4376 		sbi->s_ea_block_cache = NULL;
4377 	}
4378 	if (sbi->s_journal) {
4379 		jbd2_journal_destroy(sbi->s_journal);
4380 		sbi->s_journal = NULL;
4381 	}
4382 failed_mount3a:
4383 	ext4_es_unregister_shrinker(sbi);
4384 failed_mount3:
4385 	del_timer_sync(&sbi->s_err_report);
4386 	if (sbi->s_mmp_tsk)
4387 		kthread_stop(sbi->s_mmp_tsk);
4388 failed_mount2:
4389 	for (i = 0; i < db_count; i++)
4390 		brelse(sbi->s_group_desc[i]);
4391 	kvfree(sbi->s_group_desc);
4392 failed_mount:
4393 	if (sbi->s_chksum_driver)
4394 		crypto_free_shash(sbi->s_chksum_driver);
4395 #ifdef CONFIG_QUOTA
4396 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4397 		kfree(sbi->s_qf_names[i]);
4398 #endif
4399 	ext4_blkdev_remove(sbi);
4400 	brelse(bh);
4401 out_fail:
4402 	sb->s_fs_info = NULL;
4403 	kfree(sbi->s_blockgroup_lock);
4404 out_free_base:
4405 	kfree(sbi);
4406 	kfree(orig_data);
4407 	fs_put_dax(dax_dev);
4408 	return err ? err : ret;
4409 }
4410 
4411 /*
4412  * Setup any per-fs journal parameters now.  We'll do this both on
4413  * initial mount, once the journal has been initialised but before we've
4414  * done any recovery; and again on any subsequent remount.
4415  */
4416 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4417 {
4418 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4419 
4420 	journal->j_commit_interval = sbi->s_commit_interval;
4421 	journal->j_min_batch_time = sbi->s_min_batch_time;
4422 	journal->j_max_batch_time = sbi->s_max_batch_time;
4423 
4424 	write_lock(&journal->j_state_lock);
4425 	if (test_opt(sb, BARRIER))
4426 		journal->j_flags |= JBD2_BARRIER;
4427 	else
4428 		journal->j_flags &= ~JBD2_BARRIER;
4429 	if (test_opt(sb, DATA_ERR_ABORT))
4430 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4431 	else
4432 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4433 	write_unlock(&journal->j_state_lock);
4434 }
4435 
4436 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4437 					     unsigned int journal_inum)
4438 {
4439 	struct inode *journal_inode;
4440 
4441 	/*
4442 	 * Test for the existence of a valid inode on disk.  Bad things
4443 	 * happen if we iget() an unused inode, as the subsequent iput()
4444 	 * will try to delete it.
4445 	 */
4446 	journal_inode = ext4_iget(sb, journal_inum);
4447 	if (IS_ERR(journal_inode)) {
4448 		ext4_msg(sb, KERN_ERR, "no journal found");
4449 		return NULL;
4450 	}
4451 	if (!journal_inode->i_nlink) {
4452 		make_bad_inode(journal_inode);
4453 		iput(journal_inode);
4454 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4455 		return NULL;
4456 	}
4457 
4458 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4459 		  journal_inode, journal_inode->i_size);
4460 	if (!S_ISREG(journal_inode->i_mode)) {
4461 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4462 		iput(journal_inode);
4463 		return NULL;
4464 	}
4465 	return journal_inode;
4466 }
4467 
4468 static journal_t *ext4_get_journal(struct super_block *sb,
4469 				   unsigned int journal_inum)
4470 {
4471 	struct inode *journal_inode;
4472 	journal_t *journal;
4473 
4474 	BUG_ON(!ext4_has_feature_journal(sb));
4475 
4476 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4477 	if (!journal_inode)
4478 		return NULL;
4479 
4480 	journal = jbd2_journal_init_inode(journal_inode);
4481 	if (!journal) {
4482 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4483 		iput(journal_inode);
4484 		return NULL;
4485 	}
4486 	journal->j_private = sb;
4487 	ext4_init_journal_params(sb, journal);
4488 	return journal;
4489 }
4490 
4491 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4492 				       dev_t j_dev)
4493 {
4494 	struct buffer_head *bh;
4495 	journal_t *journal;
4496 	ext4_fsblk_t start;
4497 	ext4_fsblk_t len;
4498 	int hblock, blocksize;
4499 	ext4_fsblk_t sb_block;
4500 	unsigned long offset;
4501 	struct ext4_super_block *es;
4502 	struct block_device *bdev;
4503 
4504 	BUG_ON(!ext4_has_feature_journal(sb));
4505 
4506 	bdev = ext4_blkdev_get(j_dev, sb);
4507 	if (bdev == NULL)
4508 		return NULL;
4509 
4510 	blocksize = sb->s_blocksize;
4511 	hblock = bdev_logical_block_size(bdev);
4512 	if (blocksize < hblock) {
4513 		ext4_msg(sb, KERN_ERR,
4514 			"blocksize too small for journal device");
4515 		goto out_bdev;
4516 	}
4517 
4518 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4519 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4520 	set_blocksize(bdev, blocksize);
4521 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4522 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4523 		       "external journal");
4524 		goto out_bdev;
4525 	}
4526 
4527 	es = (struct ext4_super_block *) (bh->b_data + offset);
4528 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4529 	    !(le32_to_cpu(es->s_feature_incompat) &
4530 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4531 		ext4_msg(sb, KERN_ERR, "external journal has "
4532 					"bad superblock");
4533 		brelse(bh);
4534 		goto out_bdev;
4535 	}
4536 
4537 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4538 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4539 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4540 		ext4_msg(sb, KERN_ERR, "external journal has "
4541 				       "corrupt superblock");
4542 		brelse(bh);
4543 		goto out_bdev;
4544 	}
4545 
4546 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4547 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4548 		brelse(bh);
4549 		goto out_bdev;
4550 	}
4551 
4552 	len = ext4_blocks_count(es);
4553 	start = sb_block + 1;
4554 	brelse(bh);	/* we're done with the superblock */
4555 
4556 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4557 					start, len, blocksize);
4558 	if (!journal) {
4559 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4560 		goto out_bdev;
4561 	}
4562 	journal->j_private = sb;
4563 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4564 	wait_on_buffer(journal->j_sb_buffer);
4565 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4566 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4567 		goto out_journal;
4568 	}
4569 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4570 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4571 					"user (unsupported) - %d",
4572 			be32_to_cpu(journal->j_superblock->s_nr_users));
4573 		goto out_journal;
4574 	}
4575 	EXT4_SB(sb)->journal_bdev = bdev;
4576 	ext4_init_journal_params(sb, journal);
4577 	return journal;
4578 
4579 out_journal:
4580 	jbd2_journal_destroy(journal);
4581 out_bdev:
4582 	ext4_blkdev_put(bdev);
4583 	return NULL;
4584 }
4585 
4586 static int ext4_load_journal(struct super_block *sb,
4587 			     struct ext4_super_block *es,
4588 			     unsigned long journal_devnum)
4589 {
4590 	journal_t *journal;
4591 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4592 	dev_t journal_dev;
4593 	int err = 0;
4594 	int really_read_only;
4595 
4596 	BUG_ON(!ext4_has_feature_journal(sb));
4597 
4598 	if (journal_devnum &&
4599 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4600 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4601 			"numbers have changed");
4602 		journal_dev = new_decode_dev(journal_devnum);
4603 	} else
4604 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4605 
4606 	really_read_only = bdev_read_only(sb->s_bdev);
4607 
4608 	/*
4609 	 * Are we loading a blank journal or performing recovery after a
4610 	 * crash?  For recovery, we need to check in advance whether we
4611 	 * can get read-write access to the device.
4612 	 */
4613 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4614 		if (sb_rdonly(sb)) {
4615 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4616 					"required on readonly filesystem");
4617 			if (really_read_only) {
4618 				ext4_msg(sb, KERN_ERR, "write access "
4619 					"unavailable, cannot proceed "
4620 					"(try mounting with noload)");
4621 				return -EROFS;
4622 			}
4623 			ext4_msg(sb, KERN_INFO, "write access will "
4624 			       "be enabled during recovery");
4625 		}
4626 	}
4627 
4628 	if (journal_inum && journal_dev) {
4629 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4630 		       "and inode journals!");
4631 		return -EINVAL;
4632 	}
4633 
4634 	if (journal_inum) {
4635 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4636 			return -EINVAL;
4637 	} else {
4638 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4639 			return -EINVAL;
4640 	}
4641 
4642 	if (!(journal->j_flags & JBD2_BARRIER))
4643 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4644 
4645 	if (!ext4_has_feature_journal_needs_recovery(sb))
4646 		err = jbd2_journal_wipe(journal, !really_read_only);
4647 	if (!err) {
4648 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4649 		if (save)
4650 			memcpy(save, ((char *) es) +
4651 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4652 		err = jbd2_journal_load(journal);
4653 		if (save)
4654 			memcpy(((char *) es) + EXT4_S_ERR_START,
4655 			       save, EXT4_S_ERR_LEN);
4656 		kfree(save);
4657 	}
4658 
4659 	if (err) {
4660 		ext4_msg(sb, KERN_ERR, "error loading journal");
4661 		jbd2_journal_destroy(journal);
4662 		return err;
4663 	}
4664 
4665 	EXT4_SB(sb)->s_journal = journal;
4666 	ext4_clear_journal_err(sb, es);
4667 
4668 	if (!really_read_only && journal_devnum &&
4669 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4670 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4671 
4672 		/* Make sure we flush the recovery flag to disk. */
4673 		ext4_commit_super(sb, 1);
4674 	}
4675 
4676 	return 0;
4677 }
4678 
4679 static int ext4_commit_super(struct super_block *sb, int sync)
4680 {
4681 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4682 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4683 	int error = 0;
4684 
4685 	if (!sbh || block_device_ejected(sb))
4686 		return error;
4687 	/*
4688 	 * If the file system is mounted read-only, don't update the
4689 	 * superblock write time.  This avoids updating the superblock
4690 	 * write time when we are mounting the root file system
4691 	 * read/only but we need to replay the journal; at that point,
4692 	 * for people who are east of GMT and who make their clock
4693 	 * tick in localtime for Windows bug-for-bug compatibility,
4694 	 * the clock is set in the future, and this will cause e2fsck
4695 	 * to complain and force a full file system check.
4696 	 */
4697 	if (!(sb->s_flags & SB_RDONLY))
4698 		es->s_wtime = cpu_to_le32(get_seconds());
4699 	if (sb->s_bdev->bd_part)
4700 		es->s_kbytes_written =
4701 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4702 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4703 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4704 	else
4705 		es->s_kbytes_written =
4706 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4707 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4708 		ext4_free_blocks_count_set(es,
4709 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4710 				&EXT4_SB(sb)->s_freeclusters_counter)));
4711 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4712 		es->s_free_inodes_count =
4713 			cpu_to_le32(percpu_counter_sum_positive(
4714 				&EXT4_SB(sb)->s_freeinodes_counter));
4715 	BUFFER_TRACE(sbh, "marking dirty");
4716 	ext4_superblock_csum_set(sb);
4717 	if (sync)
4718 		lock_buffer(sbh);
4719 	if (buffer_write_io_error(sbh)) {
4720 		/*
4721 		 * Oh, dear.  A previous attempt to write the
4722 		 * superblock failed.  This could happen because the
4723 		 * USB device was yanked out.  Or it could happen to
4724 		 * be a transient write error and maybe the block will
4725 		 * be remapped.  Nothing we can do but to retry the
4726 		 * write and hope for the best.
4727 		 */
4728 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4729 		       "superblock detected");
4730 		clear_buffer_write_io_error(sbh);
4731 		set_buffer_uptodate(sbh);
4732 	}
4733 	mark_buffer_dirty(sbh);
4734 	if (sync) {
4735 		unlock_buffer(sbh);
4736 		error = __sync_dirty_buffer(sbh,
4737 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4738 		if (error)
4739 			return error;
4740 
4741 		error = buffer_write_io_error(sbh);
4742 		if (error) {
4743 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4744 			       "superblock");
4745 			clear_buffer_write_io_error(sbh);
4746 			set_buffer_uptodate(sbh);
4747 		}
4748 	}
4749 	return error;
4750 }
4751 
4752 /*
4753  * Have we just finished recovery?  If so, and if we are mounting (or
4754  * remounting) the filesystem readonly, then we will end up with a
4755  * consistent fs on disk.  Record that fact.
4756  */
4757 static void ext4_mark_recovery_complete(struct super_block *sb,
4758 					struct ext4_super_block *es)
4759 {
4760 	journal_t *journal = EXT4_SB(sb)->s_journal;
4761 
4762 	if (!ext4_has_feature_journal(sb)) {
4763 		BUG_ON(journal != NULL);
4764 		return;
4765 	}
4766 	jbd2_journal_lock_updates(journal);
4767 	if (jbd2_journal_flush(journal) < 0)
4768 		goto out;
4769 
4770 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
4771 		ext4_clear_feature_journal_needs_recovery(sb);
4772 		ext4_commit_super(sb, 1);
4773 	}
4774 
4775 out:
4776 	jbd2_journal_unlock_updates(journal);
4777 }
4778 
4779 /*
4780  * If we are mounting (or read-write remounting) a filesystem whose journal
4781  * has recorded an error from a previous lifetime, move that error to the
4782  * main filesystem now.
4783  */
4784 static void ext4_clear_journal_err(struct super_block *sb,
4785 				   struct ext4_super_block *es)
4786 {
4787 	journal_t *journal;
4788 	int j_errno;
4789 	const char *errstr;
4790 
4791 	BUG_ON(!ext4_has_feature_journal(sb));
4792 
4793 	journal = EXT4_SB(sb)->s_journal;
4794 
4795 	/*
4796 	 * Now check for any error status which may have been recorded in the
4797 	 * journal by a prior ext4_error() or ext4_abort()
4798 	 */
4799 
4800 	j_errno = jbd2_journal_errno(journal);
4801 	if (j_errno) {
4802 		char nbuf[16];
4803 
4804 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4805 		ext4_warning(sb, "Filesystem error recorded "
4806 			     "from previous mount: %s", errstr);
4807 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4808 
4809 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4810 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4811 		ext4_commit_super(sb, 1);
4812 
4813 		jbd2_journal_clear_err(journal);
4814 		jbd2_journal_update_sb_errno(journal);
4815 	}
4816 }
4817 
4818 /*
4819  * Force the running and committing transactions to commit,
4820  * and wait on the commit.
4821  */
4822 int ext4_force_commit(struct super_block *sb)
4823 {
4824 	journal_t *journal;
4825 
4826 	if (sb_rdonly(sb))
4827 		return 0;
4828 
4829 	journal = EXT4_SB(sb)->s_journal;
4830 	return ext4_journal_force_commit(journal);
4831 }
4832 
4833 static int ext4_sync_fs(struct super_block *sb, int wait)
4834 {
4835 	int ret = 0;
4836 	tid_t target;
4837 	bool needs_barrier = false;
4838 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4839 
4840 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
4841 		return 0;
4842 
4843 	trace_ext4_sync_fs(sb, wait);
4844 	flush_workqueue(sbi->rsv_conversion_wq);
4845 	/*
4846 	 * Writeback quota in non-journalled quota case - journalled quota has
4847 	 * no dirty dquots
4848 	 */
4849 	dquot_writeback_dquots(sb, -1);
4850 	/*
4851 	 * Data writeback is possible w/o journal transaction, so barrier must
4852 	 * being sent at the end of the function. But we can skip it if
4853 	 * transaction_commit will do it for us.
4854 	 */
4855 	if (sbi->s_journal) {
4856 		target = jbd2_get_latest_transaction(sbi->s_journal);
4857 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4858 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4859 			needs_barrier = true;
4860 
4861 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4862 			if (wait)
4863 				ret = jbd2_log_wait_commit(sbi->s_journal,
4864 							   target);
4865 		}
4866 	} else if (wait && test_opt(sb, BARRIER))
4867 		needs_barrier = true;
4868 	if (needs_barrier) {
4869 		int err;
4870 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4871 		if (!ret)
4872 			ret = err;
4873 	}
4874 
4875 	return ret;
4876 }
4877 
4878 /*
4879  * LVM calls this function before a (read-only) snapshot is created.  This
4880  * gives us a chance to flush the journal completely and mark the fs clean.
4881  *
4882  * Note that only this function cannot bring a filesystem to be in a clean
4883  * state independently. It relies on upper layer to stop all data & metadata
4884  * modifications.
4885  */
4886 static int ext4_freeze(struct super_block *sb)
4887 {
4888 	int error = 0;
4889 	journal_t *journal;
4890 
4891 	if (sb_rdonly(sb))
4892 		return 0;
4893 
4894 	journal = EXT4_SB(sb)->s_journal;
4895 
4896 	if (journal) {
4897 		/* Now we set up the journal barrier. */
4898 		jbd2_journal_lock_updates(journal);
4899 
4900 		/*
4901 		 * Don't clear the needs_recovery flag if we failed to
4902 		 * flush the journal.
4903 		 */
4904 		error = jbd2_journal_flush(journal);
4905 		if (error < 0)
4906 			goto out;
4907 
4908 		/* Journal blocked and flushed, clear needs_recovery flag. */
4909 		ext4_clear_feature_journal_needs_recovery(sb);
4910 	}
4911 
4912 	error = ext4_commit_super(sb, 1);
4913 out:
4914 	if (journal)
4915 		/* we rely on upper layer to stop further updates */
4916 		jbd2_journal_unlock_updates(journal);
4917 	return error;
4918 }
4919 
4920 /*
4921  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4922  * flag here, even though the filesystem is not technically dirty yet.
4923  */
4924 static int ext4_unfreeze(struct super_block *sb)
4925 {
4926 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
4927 		return 0;
4928 
4929 	if (EXT4_SB(sb)->s_journal) {
4930 		/* Reset the needs_recovery flag before the fs is unlocked. */
4931 		ext4_set_feature_journal_needs_recovery(sb);
4932 	}
4933 
4934 	ext4_commit_super(sb, 1);
4935 	return 0;
4936 }
4937 
4938 /*
4939  * Structure to save mount options for ext4_remount's benefit
4940  */
4941 struct ext4_mount_options {
4942 	unsigned long s_mount_opt;
4943 	unsigned long s_mount_opt2;
4944 	kuid_t s_resuid;
4945 	kgid_t s_resgid;
4946 	unsigned long s_commit_interval;
4947 	u32 s_min_batch_time, s_max_batch_time;
4948 #ifdef CONFIG_QUOTA
4949 	int s_jquota_fmt;
4950 	char *s_qf_names[EXT4_MAXQUOTAS];
4951 #endif
4952 };
4953 
4954 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4955 {
4956 	struct ext4_super_block *es;
4957 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4958 	unsigned long old_sb_flags;
4959 	struct ext4_mount_options old_opts;
4960 	int enable_quota = 0;
4961 	ext4_group_t g;
4962 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4963 	int err = 0;
4964 #ifdef CONFIG_QUOTA
4965 	int i, j;
4966 #endif
4967 	char *orig_data = kstrdup(data, GFP_KERNEL);
4968 
4969 	/* Store the original options */
4970 	old_sb_flags = sb->s_flags;
4971 	old_opts.s_mount_opt = sbi->s_mount_opt;
4972 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4973 	old_opts.s_resuid = sbi->s_resuid;
4974 	old_opts.s_resgid = sbi->s_resgid;
4975 	old_opts.s_commit_interval = sbi->s_commit_interval;
4976 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4977 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4978 #ifdef CONFIG_QUOTA
4979 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4980 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4981 		if (sbi->s_qf_names[i]) {
4982 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4983 							 GFP_KERNEL);
4984 			if (!old_opts.s_qf_names[i]) {
4985 				for (j = 0; j < i; j++)
4986 					kfree(old_opts.s_qf_names[j]);
4987 				kfree(orig_data);
4988 				return -ENOMEM;
4989 			}
4990 		} else
4991 			old_opts.s_qf_names[i] = NULL;
4992 #endif
4993 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4994 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4995 
4996 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4997 		err = -EINVAL;
4998 		goto restore_opts;
4999 	}
5000 
5001 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5002 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5003 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5004 			 "during remount not supported; ignoring");
5005 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5006 	}
5007 
5008 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5009 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5010 			ext4_msg(sb, KERN_ERR, "can't mount with "
5011 				 "both data=journal and delalloc");
5012 			err = -EINVAL;
5013 			goto restore_opts;
5014 		}
5015 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5016 			ext4_msg(sb, KERN_ERR, "can't mount with "
5017 				 "both data=journal and dioread_nolock");
5018 			err = -EINVAL;
5019 			goto restore_opts;
5020 		}
5021 		if (test_opt(sb, DAX)) {
5022 			ext4_msg(sb, KERN_ERR, "can't mount with "
5023 				 "both data=journal and dax");
5024 			err = -EINVAL;
5025 			goto restore_opts;
5026 		}
5027 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5028 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5029 			ext4_msg(sb, KERN_ERR, "can't mount with "
5030 				"journal_async_commit in data=ordered mode");
5031 			err = -EINVAL;
5032 			goto restore_opts;
5033 		}
5034 	}
5035 
5036 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5037 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5038 		err = -EINVAL;
5039 		goto restore_opts;
5040 	}
5041 
5042 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5043 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5044 			"dax flag with busy inodes while remounting");
5045 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5046 	}
5047 
5048 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5049 		ext4_abort(sb, "Abort forced by user");
5050 
5051 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5052 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5053 
5054 	es = sbi->s_es;
5055 
5056 	if (sbi->s_journal) {
5057 		ext4_init_journal_params(sb, sbi->s_journal);
5058 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5059 	}
5060 
5061 	if (*flags & SB_LAZYTIME)
5062 		sb->s_flags |= SB_LAZYTIME;
5063 
5064 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5065 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5066 			err = -EROFS;
5067 			goto restore_opts;
5068 		}
5069 
5070 		if (*flags & SB_RDONLY) {
5071 			err = sync_filesystem(sb);
5072 			if (err < 0)
5073 				goto restore_opts;
5074 			err = dquot_suspend(sb, -1);
5075 			if (err < 0)
5076 				goto restore_opts;
5077 
5078 			/*
5079 			 * First of all, the unconditional stuff we have to do
5080 			 * to disable replay of the journal when we next remount
5081 			 */
5082 			sb->s_flags |= SB_RDONLY;
5083 
5084 			/*
5085 			 * OK, test if we are remounting a valid rw partition
5086 			 * readonly, and if so set the rdonly flag and then
5087 			 * mark the partition as valid again.
5088 			 */
5089 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5090 			    (sbi->s_mount_state & EXT4_VALID_FS))
5091 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5092 
5093 			if (sbi->s_journal)
5094 				ext4_mark_recovery_complete(sb, es);
5095 		} else {
5096 			/* Make sure we can mount this feature set readwrite */
5097 			if (ext4_has_feature_readonly(sb) ||
5098 			    !ext4_feature_set_ok(sb, 0)) {
5099 				err = -EROFS;
5100 				goto restore_opts;
5101 			}
5102 			/*
5103 			 * Make sure the group descriptor checksums
5104 			 * are sane.  If they aren't, refuse to remount r/w.
5105 			 */
5106 			for (g = 0; g < sbi->s_groups_count; g++) {
5107 				struct ext4_group_desc *gdp =
5108 					ext4_get_group_desc(sb, g, NULL);
5109 
5110 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5111 					ext4_msg(sb, KERN_ERR,
5112 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5113 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5114 					       le16_to_cpu(gdp->bg_checksum));
5115 					err = -EFSBADCRC;
5116 					goto restore_opts;
5117 				}
5118 			}
5119 
5120 			/*
5121 			 * If we have an unprocessed orphan list hanging
5122 			 * around from a previously readonly bdev mount,
5123 			 * require a full umount/remount for now.
5124 			 */
5125 			if (es->s_last_orphan) {
5126 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5127 				       "remount RDWR because of unprocessed "
5128 				       "orphan inode list.  Please "
5129 				       "umount/remount instead");
5130 				err = -EINVAL;
5131 				goto restore_opts;
5132 			}
5133 
5134 			/*
5135 			 * Mounting a RDONLY partition read-write, so reread
5136 			 * and store the current valid flag.  (It may have
5137 			 * been changed by e2fsck since we originally mounted
5138 			 * the partition.)
5139 			 */
5140 			if (sbi->s_journal)
5141 				ext4_clear_journal_err(sb, es);
5142 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5143 			if (!ext4_setup_super(sb, es, 0))
5144 				sb->s_flags &= ~SB_RDONLY;
5145 			if (ext4_has_feature_mmp(sb))
5146 				if (ext4_multi_mount_protect(sb,
5147 						le64_to_cpu(es->s_mmp_block))) {
5148 					err = -EROFS;
5149 					goto restore_opts;
5150 				}
5151 			enable_quota = 1;
5152 		}
5153 	}
5154 
5155 	/*
5156 	 * Reinitialize lazy itable initialization thread based on
5157 	 * current settings
5158 	 */
5159 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5160 		ext4_unregister_li_request(sb);
5161 	else {
5162 		ext4_group_t first_not_zeroed;
5163 		first_not_zeroed = ext4_has_uninit_itable(sb);
5164 		ext4_register_li_request(sb, first_not_zeroed);
5165 	}
5166 
5167 	ext4_setup_system_zone(sb);
5168 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY))
5169 		ext4_commit_super(sb, 1);
5170 
5171 #ifdef CONFIG_QUOTA
5172 	/* Release old quota file names */
5173 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5174 		kfree(old_opts.s_qf_names[i]);
5175 	if (enable_quota) {
5176 		if (sb_any_quota_suspended(sb))
5177 			dquot_resume(sb, -1);
5178 		else if (ext4_has_feature_quota(sb)) {
5179 			err = ext4_enable_quotas(sb);
5180 			if (err)
5181 				goto restore_opts;
5182 		}
5183 	}
5184 #endif
5185 
5186 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5187 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5188 	kfree(orig_data);
5189 	return 0;
5190 
5191 restore_opts:
5192 	sb->s_flags = old_sb_flags;
5193 	sbi->s_mount_opt = old_opts.s_mount_opt;
5194 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5195 	sbi->s_resuid = old_opts.s_resuid;
5196 	sbi->s_resgid = old_opts.s_resgid;
5197 	sbi->s_commit_interval = old_opts.s_commit_interval;
5198 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5199 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5200 #ifdef CONFIG_QUOTA
5201 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5202 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5203 		kfree(sbi->s_qf_names[i]);
5204 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5205 	}
5206 #endif
5207 	kfree(orig_data);
5208 	return err;
5209 }
5210 
5211 #ifdef CONFIG_QUOTA
5212 static int ext4_statfs_project(struct super_block *sb,
5213 			       kprojid_t projid, struct kstatfs *buf)
5214 {
5215 	struct kqid qid;
5216 	struct dquot *dquot;
5217 	u64 limit;
5218 	u64 curblock;
5219 
5220 	qid = make_kqid_projid(projid);
5221 	dquot = dqget(sb, qid);
5222 	if (IS_ERR(dquot))
5223 		return PTR_ERR(dquot);
5224 	spin_lock(&dquot->dq_dqb_lock);
5225 
5226 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5227 		 dquot->dq_dqb.dqb_bsoftlimit :
5228 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5229 	if (limit && buf->f_blocks > limit) {
5230 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5231 		buf->f_blocks = limit;
5232 		buf->f_bfree = buf->f_bavail =
5233 			(buf->f_blocks > curblock) ?
5234 			 (buf->f_blocks - curblock) : 0;
5235 	}
5236 
5237 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5238 		dquot->dq_dqb.dqb_isoftlimit :
5239 		dquot->dq_dqb.dqb_ihardlimit;
5240 	if (limit && buf->f_files > limit) {
5241 		buf->f_files = limit;
5242 		buf->f_ffree =
5243 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5244 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5245 	}
5246 
5247 	spin_unlock(&dquot->dq_dqb_lock);
5248 	dqput(dquot);
5249 	return 0;
5250 }
5251 #endif
5252 
5253 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5254 {
5255 	struct super_block *sb = dentry->d_sb;
5256 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5257 	struct ext4_super_block *es = sbi->s_es;
5258 	ext4_fsblk_t overhead = 0, resv_blocks;
5259 	u64 fsid;
5260 	s64 bfree;
5261 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5262 
5263 	if (!test_opt(sb, MINIX_DF))
5264 		overhead = sbi->s_overhead;
5265 
5266 	buf->f_type = EXT4_SUPER_MAGIC;
5267 	buf->f_bsize = sb->s_blocksize;
5268 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5269 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5270 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5271 	/* prevent underflow in case that few free space is available */
5272 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5273 	buf->f_bavail = buf->f_bfree -
5274 			(ext4_r_blocks_count(es) + resv_blocks);
5275 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5276 		buf->f_bavail = 0;
5277 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5278 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5279 	buf->f_namelen = EXT4_NAME_LEN;
5280 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5281 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5282 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5283 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5284 
5285 #ifdef CONFIG_QUOTA
5286 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5287 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5288 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5289 #endif
5290 	return 0;
5291 }
5292 
5293 
5294 #ifdef CONFIG_QUOTA
5295 
5296 /*
5297  * Helper functions so that transaction is started before we acquire dqio_sem
5298  * to keep correct lock ordering of transaction > dqio_sem
5299  */
5300 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5301 {
5302 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5303 }
5304 
5305 static int ext4_write_dquot(struct dquot *dquot)
5306 {
5307 	int ret, err;
5308 	handle_t *handle;
5309 	struct inode *inode;
5310 
5311 	inode = dquot_to_inode(dquot);
5312 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5313 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5314 	if (IS_ERR(handle))
5315 		return PTR_ERR(handle);
5316 	ret = dquot_commit(dquot);
5317 	err = ext4_journal_stop(handle);
5318 	if (!ret)
5319 		ret = err;
5320 	return ret;
5321 }
5322 
5323 static int ext4_acquire_dquot(struct dquot *dquot)
5324 {
5325 	int ret, err;
5326 	handle_t *handle;
5327 
5328 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5329 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5330 	if (IS_ERR(handle))
5331 		return PTR_ERR(handle);
5332 	ret = dquot_acquire(dquot);
5333 	err = ext4_journal_stop(handle);
5334 	if (!ret)
5335 		ret = err;
5336 	return ret;
5337 }
5338 
5339 static int ext4_release_dquot(struct dquot *dquot)
5340 {
5341 	int ret, err;
5342 	handle_t *handle;
5343 
5344 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5345 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5346 	if (IS_ERR(handle)) {
5347 		/* Release dquot anyway to avoid endless cycle in dqput() */
5348 		dquot_release(dquot);
5349 		return PTR_ERR(handle);
5350 	}
5351 	ret = dquot_release(dquot);
5352 	err = ext4_journal_stop(handle);
5353 	if (!ret)
5354 		ret = err;
5355 	return ret;
5356 }
5357 
5358 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5359 {
5360 	struct super_block *sb = dquot->dq_sb;
5361 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5362 
5363 	/* Are we journaling quotas? */
5364 	if (ext4_has_feature_quota(sb) ||
5365 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5366 		dquot_mark_dquot_dirty(dquot);
5367 		return ext4_write_dquot(dquot);
5368 	} else {
5369 		return dquot_mark_dquot_dirty(dquot);
5370 	}
5371 }
5372 
5373 static int ext4_write_info(struct super_block *sb, int type)
5374 {
5375 	int ret, err;
5376 	handle_t *handle;
5377 
5378 	/* Data block + inode block */
5379 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5380 	if (IS_ERR(handle))
5381 		return PTR_ERR(handle);
5382 	ret = dquot_commit_info(sb, type);
5383 	err = ext4_journal_stop(handle);
5384 	if (!ret)
5385 		ret = err;
5386 	return ret;
5387 }
5388 
5389 /*
5390  * Turn on quotas during mount time - we need to find
5391  * the quota file and such...
5392  */
5393 static int ext4_quota_on_mount(struct super_block *sb, int type)
5394 {
5395 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5396 					EXT4_SB(sb)->s_jquota_fmt, type);
5397 }
5398 
5399 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5400 {
5401 	struct ext4_inode_info *ei = EXT4_I(inode);
5402 
5403 	/* The first argument of lockdep_set_subclass has to be
5404 	 * *exactly* the same as the argument to init_rwsem() --- in
5405 	 * this case, in init_once() --- or lockdep gets unhappy
5406 	 * because the name of the lock is set using the
5407 	 * stringification of the argument to init_rwsem().
5408 	 */
5409 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5410 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5411 }
5412 
5413 /*
5414  * Standard function to be called on quota_on
5415  */
5416 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5417 			 const struct path *path)
5418 {
5419 	int err;
5420 
5421 	if (!test_opt(sb, QUOTA))
5422 		return -EINVAL;
5423 
5424 	/* Quotafile not on the same filesystem? */
5425 	if (path->dentry->d_sb != sb)
5426 		return -EXDEV;
5427 	/* Journaling quota? */
5428 	if (EXT4_SB(sb)->s_qf_names[type]) {
5429 		/* Quotafile not in fs root? */
5430 		if (path->dentry->d_parent != sb->s_root)
5431 			ext4_msg(sb, KERN_WARNING,
5432 				"Quota file not on filesystem root. "
5433 				"Journaled quota will not work");
5434 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5435 	} else {
5436 		/*
5437 		 * Clear the flag just in case mount options changed since
5438 		 * last time.
5439 		 */
5440 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5441 	}
5442 
5443 	/*
5444 	 * When we journal data on quota file, we have to flush journal to see
5445 	 * all updates to the file when we bypass pagecache...
5446 	 */
5447 	if (EXT4_SB(sb)->s_journal &&
5448 	    ext4_should_journal_data(d_inode(path->dentry))) {
5449 		/*
5450 		 * We don't need to lock updates but journal_flush() could
5451 		 * otherwise be livelocked...
5452 		 */
5453 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5454 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5455 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5456 		if (err)
5457 			return err;
5458 	}
5459 
5460 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5461 	err = dquot_quota_on(sb, type, format_id, path);
5462 	if (err) {
5463 		lockdep_set_quota_inode(path->dentry->d_inode,
5464 					     I_DATA_SEM_NORMAL);
5465 	} else {
5466 		struct inode *inode = d_inode(path->dentry);
5467 		handle_t *handle;
5468 
5469 		/*
5470 		 * Set inode flags to prevent userspace from messing with quota
5471 		 * files. If this fails, we return success anyway since quotas
5472 		 * are already enabled and this is not a hard failure.
5473 		 */
5474 		inode_lock(inode);
5475 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5476 		if (IS_ERR(handle))
5477 			goto unlock_inode;
5478 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5479 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5480 				S_NOATIME | S_IMMUTABLE);
5481 		ext4_mark_inode_dirty(handle, inode);
5482 		ext4_journal_stop(handle);
5483 	unlock_inode:
5484 		inode_unlock(inode);
5485 	}
5486 	return err;
5487 }
5488 
5489 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5490 			     unsigned int flags)
5491 {
5492 	int err;
5493 	struct inode *qf_inode;
5494 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5495 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5496 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5497 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5498 	};
5499 
5500 	BUG_ON(!ext4_has_feature_quota(sb));
5501 
5502 	if (!qf_inums[type])
5503 		return -EPERM;
5504 
5505 	qf_inode = ext4_iget(sb, qf_inums[type]);
5506 	if (IS_ERR(qf_inode)) {
5507 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5508 		return PTR_ERR(qf_inode);
5509 	}
5510 
5511 	/* Don't account quota for quota files to avoid recursion */
5512 	qf_inode->i_flags |= S_NOQUOTA;
5513 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5514 	err = dquot_enable(qf_inode, type, format_id, flags);
5515 	iput(qf_inode);
5516 	if (err)
5517 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5518 
5519 	return err;
5520 }
5521 
5522 /* Enable usage tracking for all quota types. */
5523 static int ext4_enable_quotas(struct super_block *sb)
5524 {
5525 	int type, err = 0;
5526 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5527 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5528 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5529 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5530 	};
5531 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5532 		test_opt(sb, USRQUOTA),
5533 		test_opt(sb, GRPQUOTA),
5534 		test_opt(sb, PRJQUOTA),
5535 	};
5536 
5537 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5538 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5539 		if (qf_inums[type]) {
5540 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5541 				DQUOT_USAGE_ENABLED |
5542 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5543 			if (err) {
5544 				for (type--; type >= 0; type--)
5545 					dquot_quota_off(sb, type);
5546 
5547 				ext4_warning(sb,
5548 					"Failed to enable quota tracking "
5549 					"(type=%d, err=%d). Please run "
5550 					"e2fsck to fix.", type, err);
5551 				return err;
5552 			}
5553 		}
5554 	}
5555 	return 0;
5556 }
5557 
5558 static int ext4_quota_off(struct super_block *sb, int type)
5559 {
5560 	struct inode *inode = sb_dqopt(sb)->files[type];
5561 	handle_t *handle;
5562 	int err;
5563 
5564 	/* Force all delayed allocation blocks to be allocated.
5565 	 * Caller already holds s_umount sem */
5566 	if (test_opt(sb, DELALLOC))
5567 		sync_filesystem(sb);
5568 
5569 	if (!inode || !igrab(inode))
5570 		goto out;
5571 
5572 	err = dquot_quota_off(sb, type);
5573 	if (err || ext4_has_feature_quota(sb))
5574 		goto out_put;
5575 
5576 	inode_lock(inode);
5577 	/*
5578 	 * Update modification times of quota files when userspace can
5579 	 * start looking at them. If we fail, we return success anyway since
5580 	 * this is not a hard failure and quotas are already disabled.
5581 	 */
5582 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5583 	if (IS_ERR(handle))
5584 		goto out_unlock;
5585 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5586 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5587 	inode->i_mtime = inode->i_ctime = current_time(inode);
5588 	ext4_mark_inode_dirty(handle, inode);
5589 	ext4_journal_stop(handle);
5590 out_unlock:
5591 	inode_unlock(inode);
5592 out_put:
5593 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5594 	iput(inode);
5595 	return err;
5596 out:
5597 	return dquot_quota_off(sb, type);
5598 }
5599 
5600 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5601  * acquiring the locks... As quota files are never truncated and quota code
5602  * itself serializes the operations (and no one else should touch the files)
5603  * we don't have to be afraid of races */
5604 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5605 			       size_t len, loff_t off)
5606 {
5607 	struct inode *inode = sb_dqopt(sb)->files[type];
5608 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5609 	int offset = off & (sb->s_blocksize - 1);
5610 	int tocopy;
5611 	size_t toread;
5612 	struct buffer_head *bh;
5613 	loff_t i_size = i_size_read(inode);
5614 
5615 	if (off > i_size)
5616 		return 0;
5617 	if (off+len > i_size)
5618 		len = i_size-off;
5619 	toread = len;
5620 	while (toread > 0) {
5621 		tocopy = sb->s_blocksize - offset < toread ?
5622 				sb->s_blocksize - offset : toread;
5623 		bh = ext4_bread(NULL, inode, blk, 0);
5624 		if (IS_ERR(bh))
5625 			return PTR_ERR(bh);
5626 		if (!bh)	/* A hole? */
5627 			memset(data, 0, tocopy);
5628 		else
5629 			memcpy(data, bh->b_data+offset, tocopy);
5630 		brelse(bh);
5631 		offset = 0;
5632 		toread -= tocopy;
5633 		data += tocopy;
5634 		blk++;
5635 	}
5636 	return len;
5637 }
5638 
5639 /* Write to quotafile (we know the transaction is already started and has
5640  * enough credits) */
5641 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5642 				const char *data, size_t len, loff_t off)
5643 {
5644 	struct inode *inode = sb_dqopt(sb)->files[type];
5645 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5646 	int err, offset = off & (sb->s_blocksize - 1);
5647 	int retries = 0;
5648 	struct buffer_head *bh;
5649 	handle_t *handle = journal_current_handle();
5650 
5651 	if (EXT4_SB(sb)->s_journal && !handle) {
5652 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5653 			" cancelled because transaction is not started",
5654 			(unsigned long long)off, (unsigned long long)len);
5655 		return -EIO;
5656 	}
5657 	/*
5658 	 * Since we account only one data block in transaction credits,
5659 	 * then it is impossible to cross a block boundary.
5660 	 */
5661 	if (sb->s_blocksize - offset < len) {
5662 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5663 			" cancelled because not block aligned",
5664 			(unsigned long long)off, (unsigned long long)len);
5665 		return -EIO;
5666 	}
5667 
5668 	do {
5669 		bh = ext4_bread(handle, inode, blk,
5670 				EXT4_GET_BLOCKS_CREATE |
5671 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5672 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5673 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5674 	if (IS_ERR(bh))
5675 		return PTR_ERR(bh);
5676 	if (!bh)
5677 		goto out;
5678 	BUFFER_TRACE(bh, "get write access");
5679 	err = ext4_journal_get_write_access(handle, bh);
5680 	if (err) {
5681 		brelse(bh);
5682 		return err;
5683 	}
5684 	lock_buffer(bh);
5685 	memcpy(bh->b_data+offset, data, len);
5686 	flush_dcache_page(bh->b_page);
5687 	unlock_buffer(bh);
5688 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5689 	brelse(bh);
5690 out:
5691 	if (inode->i_size < off + len) {
5692 		i_size_write(inode, off + len);
5693 		EXT4_I(inode)->i_disksize = inode->i_size;
5694 		ext4_mark_inode_dirty(handle, inode);
5695 	}
5696 	return len;
5697 }
5698 
5699 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5700 {
5701 	const struct quota_format_ops	*ops;
5702 
5703 	if (!sb_has_quota_loaded(sb, qid->type))
5704 		return -ESRCH;
5705 	ops = sb_dqopt(sb)->ops[qid->type];
5706 	if (!ops || !ops->get_next_id)
5707 		return -ENOSYS;
5708 	return dquot_get_next_id(sb, qid);
5709 }
5710 #endif
5711 
5712 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5713 		       const char *dev_name, void *data)
5714 {
5715 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5716 }
5717 
5718 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5719 static inline void register_as_ext2(void)
5720 {
5721 	int err = register_filesystem(&ext2_fs_type);
5722 	if (err)
5723 		printk(KERN_WARNING
5724 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5725 }
5726 
5727 static inline void unregister_as_ext2(void)
5728 {
5729 	unregister_filesystem(&ext2_fs_type);
5730 }
5731 
5732 static inline int ext2_feature_set_ok(struct super_block *sb)
5733 {
5734 	if (ext4_has_unknown_ext2_incompat_features(sb))
5735 		return 0;
5736 	if (sb_rdonly(sb))
5737 		return 1;
5738 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5739 		return 0;
5740 	return 1;
5741 }
5742 #else
5743 static inline void register_as_ext2(void) { }
5744 static inline void unregister_as_ext2(void) { }
5745 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5746 #endif
5747 
5748 static inline void register_as_ext3(void)
5749 {
5750 	int err = register_filesystem(&ext3_fs_type);
5751 	if (err)
5752 		printk(KERN_WARNING
5753 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5754 }
5755 
5756 static inline void unregister_as_ext3(void)
5757 {
5758 	unregister_filesystem(&ext3_fs_type);
5759 }
5760 
5761 static inline int ext3_feature_set_ok(struct super_block *sb)
5762 {
5763 	if (ext4_has_unknown_ext3_incompat_features(sb))
5764 		return 0;
5765 	if (!ext4_has_feature_journal(sb))
5766 		return 0;
5767 	if (sb_rdonly(sb))
5768 		return 1;
5769 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5770 		return 0;
5771 	return 1;
5772 }
5773 
5774 static struct file_system_type ext4_fs_type = {
5775 	.owner		= THIS_MODULE,
5776 	.name		= "ext4",
5777 	.mount		= ext4_mount,
5778 	.kill_sb	= kill_block_super,
5779 	.fs_flags	= FS_REQUIRES_DEV,
5780 };
5781 MODULE_ALIAS_FS("ext4");
5782 
5783 /* Shared across all ext4 file systems */
5784 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5785 
5786 static int __init ext4_init_fs(void)
5787 {
5788 	int i, err;
5789 
5790 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5791 	ext4_li_info = NULL;
5792 	mutex_init(&ext4_li_mtx);
5793 
5794 	/* Build-time check for flags consistency */
5795 	ext4_check_flag_values();
5796 
5797 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5798 		init_waitqueue_head(&ext4__ioend_wq[i]);
5799 
5800 	err = ext4_init_es();
5801 	if (err)
5802 		return err;
5803 
5804 	err = ext4_init_pageio();
5805 	if (err)
5806 		goto out5;
5807 
5808 	err = ext4_init_system_zone();
5809 	if (err)
5810 		goto out4;
5811 
5812 	err = ext4_init_sysfs();
5813 	if (err)
5814 		goto out3;
5815 
5816 	err = ext4_init_mballoc();
5817 	if (err)
5818 		goto out2;
5819 	err = init_inodecache();
5820 	if (err)
5821 		goto out1;
5822 	register_as_ext3();
5823 	register_as_ext2();
5824 	err = register_filesystem(&ext4_fs_type);
5825 	if (err)
5826 		goto out;
5827 
5828 	return 0;
5829 out:
5830 	unregister_as_ext2();
5831 	unregister_as_ext3();
5832 	destroy_inodecache();
5833 out1:
5834 	ext4_exit_mballoc();
5835 out2:
5836 	ext4_exit_sysfs();
5837 out3:
5838 	ext4_exit_system_zone();
5839 out4:
5840 	ext4_exit_pageio();
5841 out5:
5842 	ext4_exit_es();
5843 
5844 	return err;
5845 }
5846 
5847 static void __exit ext4_exit_fs(void)
5848 {
5849 	ext4_destroy_lazyinit_thread();
5850 	unregister_as_ext2();
5851 	unregister_as_ext3();
5852 	unregister_filesystem(&ext4_fs_type);
5853 	destroy_inodecache();
5854 	ext4_exit_mballoc();
5855 	ext4_exit_sysfs();
5856 	ext4_exit_system_zone();
5857 	ext4_exit_pageio();
5858 	ext4_exit_es();
5859 }
5860 
5861 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5862 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5863 MODULE_LICENSE("GPL");
5864 module_init(ext4_init_fs)
5865 module_exit(ext4_exit_fs)
5866