xref: /openbmc/linux/fs/ext4/super.c (revision 95298d63)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/cleancache.h>
43 #include <linux/uaccess.h>
44 #include <linux/iversion.h>
45 #include <linux/unicode.h>
46 #include <linux/part_stat.h>
47 #include <linux/kthread.h>
48 #include <linux/freezer.h>
49 
50 #include "ext4.h"
51 #include "ext4_extents.h"	/* Needed for trace points definition */
52 #include "ext4_jbd2.h"
53 #include "xattr.h"
54 #include "acl.h"
55 #include "mballoc.h"
56 #include "fsmap.h"
57 
58 #define CREATE_TRACE_POINTS
59 #include <trace/events/ext4.h>
60 
61 static struct ext4_lazy_init *ext4_li_info;
62 static struct mutex ext4_li_mtx;
63 static struct ratelimit_state ext4_mount_msg_ratelimit;
64 
65 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
66 			     unsigned long journal_devnum);
67 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
68 static int ext4_commit_super(struct super_block *sb, int sync);
69 static void ext4_mark_recovery_complete(struct super_block *sb,
70 					struct ext4_super_block *es);
71 static void ext4_clear_journal_err(struct super_block *sb,
72 				   struct ext4_super_block *es);
73 static int ext4_sync_fs(struct super_block *sb, int wait);
74 static int ext4_remount(struct super_block *sb, int *flags, char *data);
75 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
76 static int ext4_unfreeze(struct super_block *sb);
77 static int ext4_freeze(struct super_block *sb);
78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
79 		       const char *dev_name, void *data);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
83 static void ext4_destroy_lazyinit_thread(void);
84 static void ext4_unregister_li_request(struct super_block *sb);
85 static void ext4_clear_request_list(void);
86 static struct inode *ext4_get_journal_inode(struct super_block *sb,
87 					    unsigned int journal_inum);
88 
89 /*
90  * Lock ordering
91  *
92  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
93  * i_mmap_rwsem (inode->i_mmap_rwsem)!
94  *
95  * page fault path:
96  * mmap_lock -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
97  *   page lock -> i_data_sem (rw)
98  *
99  * buffered write path:
100  * sb_start_write -> i_mutex -> mmap_lock
101  * sb_start_write -> i_mutex -> transaction start -> page lock ->
102  *   i_data_sem (rw)
103  *
104  * truncate:
105  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
106  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
107  *   i_data_sem (rw)
108  *
109  * direct IO:
110  * sb_start_write -> i_mutex -> mmap_lock
111  * sb_start_write -> i_mutex -> 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 /*
145  * This works like sb_bread() except it uses ERR_PTR for error
146  * returns.  Currently with sb_bread it's impossible to distinguish
147  * between ENOMEM and EIO situations (since both result in a NULL
148  * return.
149  */
150 struct buffer_head *
151 ext4_sb_bread(struct super_block *sb, sector_t block, int op_flags)
152 {
153 	struct buffer_head *bh = sb_getblk(sb, block);
154 
155 	if (bh == NULL)
156 		return ERR_PTR(-ENOMEM);
157 	if (ext4_buffer_uptodate(bh))
158 		return bh;
159 	ll_rw_block(REQ_OP_READ, REQ_META | op_flags, 1, &bh);
160 	wait_on_buffer(bh);
161 	if (buffer_uptodate(bh))
162 		return bh;
163 	put_bh(bh);
164 	return ERR_PTR(-EIO);
165 }
166 
167 static int ext4_verify_csum_type(struct super_block *sb,
168 				 struct ext4_super_block *es)
169 {
170 	if (!ext4_has_feature_metadata_csum(sb))
171 		return 1;
172 
173 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
174 }
175 
176 static __le32 ext4_superblock_csum(struct super_block *sb,
177 				   struct ext4_super_block *es)
178 {
179 	struct ext4_sb_info *sbi = EXT4_SB(sb);
180 	int offset = offsetof(struct ext4_super_block, s_checksum);
181 	__u32 csum;
182 
183 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
184 
185 	return cpu_to_le32(csum);
186 }
187 
188 static int ext4_superblock_csum_verify(struct super_block *sb,
189 				       struct ext4_super_block *es)
190 {
191 	if (!ext4_has_metadata_csum(sb))
192 		return 1;
193 
194 	return es->s_checksum == ext4_superblock_csum(sb, es);
195 }
196 
197 void ext4_superblock_csum_set(struct super_block *sb)
198 {
199 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
200 
201 	if (!ext4_has_metadata_csum(sb))
202 		return;
203 
204 	es->s_checksum = ext4_superblock_csum(sb, es);
205 }
206 
207 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
208 			       struct ext4_group_desc *bg)
209 {
210 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
211 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
212 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
213 }
214 
215 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
216 			       struct ext4_group_desc *bg)
217 {
218 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
219 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
220 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
221 }
222 
223 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
224 			      struct ext4_group_desc *bg)
225 {
226 	return le32_to_cpu(bg->bg_inode_table_lo) |
227 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
228 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
229 }
230 
231 __u32 ext4_free_group_clusters(struct super_block *sb,
232 			       struct ext4_group_desc *bg)
233 {
234 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
235 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
236 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
237 }
238 
239 __u32 ext4_free_inodes_count(struct super_block *sb,
240 			      struct ext4_group_desc *bg)
241 {
242 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
243 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
244 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
245 }
246 
247 __u32 ext4_used_dirs_count(struct super_block *sb,
248 			      struct ext4_group_desc *bg)
249 {
250 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
251 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
252 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
253 }
254 
255 __u32 ext4_itable_unused_count(struct super_block *sb,
256 			      struct ext4_group_desc *bg)
257 {
258 	return le16_to_cpu(bg->bg_itable_unused_lo) |
259 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
260 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
261 }
262 
263 void ext4_block_bitmap_set(struct super_block *sb,
264 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
265 {
266 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
267 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
268 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
269 }
270 
271 void ext4_inode_bitmap_set(struct super_block *sb,
272 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
273 {
274 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
275 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
276 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
277 }
278 
279 void ext4_inode_table_set(struct super_block *sb,
280 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
281 {
282 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
283 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
284 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
285 }
286 
287 void ext4_free_group_clusters_set(struct super_block *sb,
288 				  struct ext4_group_desc *bg, __u32 count)
289 {
290 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
291 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
292 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
293 }
294 
295 void ext4_free_inodes_set(struct super_block *sb,
296 			  struct ext4_group_desc *bg, __u32 count)
297 {
298 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
299 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
300 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
301 }
302 
303 void ext4_used_dirs_set(struct super_block *sb,
304 			  struct ext4_group_desc *bg, __u32 count)
305 {
306 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
307 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
308 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
309 }
310 
311 void ext4_itable_unused_set(struct super_block *sb,
312 			  struct ext4_group_desc *bg, __u32 count)
313 {
314 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
315 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
316 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
317 }
318 
319 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
320 {
321 	time64_t now = ktime_get_real_seconds();
322 
323 	now = clamp_val(now, 0, (1ull << 40) - 1);
324 
325 	*lo = cpu_to_le32(lower_32_bits(now));
326 	*hi = upper_32_bits(now);
327 }
328 
329 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
330 {
331 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
332 }
333 #define ext4_update_tstamp(es, tstamp) \
334 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
335 #define ext4_get_tstamp(es, tstamp) \
336 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
337 
338 static void __save_error_info(struct super_block *sb, int error,
339 			      __u32 ino, __u64 block,
340 			      const char *func, unsigned int line)
341 {
342 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
343 	int err;
344 
345 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
346 	if (bdev_read_only(sb->s_bdev))
347 		return;
348 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
349 	ext4_update_tstamp(es, s_last_error_time);
350 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
351 	es->s_last_error_line = cpu_to_le32(line);
352 	es->s_last_error_ino = cpu_to_le32(ino);
353 	es->s_last_error_block = cpu_to_le64(block);
354 	switch (error) {
355 	case EIO:
356 		err = EXT4_ERR_EIO;
357 		break;
358 	case ENOMEM:
359 		err = EXT4_ERR_ENOMEM;
360 		break;
361 	case EFSBADCRC:
362 		err = EXT4_ERR_EFSBADCRC;
363 		break;
364 	case 0:
365 	case EFSCORRUPTED:
366 		err = EXT4_ERR_EFSCORRUPTED;
367 		break;
368 	case ENOSPC:
369 		err = EXT4_ERR_ENOSPC;
370 		break;
371 	case ENOKEY:
372 		err = EXT4_ERR_ENOKEY;
373 		break;
374 	case EROFS:
375 		err = EXT4_ERR_EROFS;
376 		break;
377 	case EFBIG:
378 		err = EXT4_ERR_EFBIG;
379 		break;
380 	case EEXIST:
381 		err = EXT4_ERR_EEXIST;
382 		break;
383 	case ERANGE:
384 		err = EXT4_ERR_ERANGE;
385 		break;
386 	case EOVERFLOW:
387 		err = EXT4_ERR_EOVERFLOW;
388 		break;
389 	case EBUSY:
390 		err = EXT4_ERR_EBUSY;
391 		break;
392 	case ENOTDIR:
393 		err = EXT4_ERR_ENOTDIR;
394 		break;
395 	case ENOTEMPTY:
396 		err = EXT4_ERR_ENOTEMPTY;
397 		break;
398 	case ESHUTDOWN:
399 		err = EXT4_ERR_ESHUTDOWN;
400 		break;
401 	case EFAULT:
402 		err = EXT4_ERR_EFAULT;
403 		break;
404 	default:
405 		err = EXT4_ERR_UNKNOWN;
406 	}
407 	es->s_last_error_errcode = err;
408 	if (!es->s_first_error_time) {
409 		es->s_first_error_time = es->s_last_error_time;
410 		es->s_first_error_time_hi = es->s_last_error_time_hi;
411 		strncpy(es->s_first_error_func, func,
412 			sizeof(es->s_first_error_func));
413 		es->s_first_error_line = cpu_to_le32(line);
414 		es->s_first_error_ino = es->s_last_error_ino;
415 		es->s_first_error_block = es->s_last_error_block;
416 		es->s_first_error_errcode = es->s_last_error_errcode;
417 	}
418 	/*
419 	 * Start the daily error reporting function if it hasn't been
420 	 * started already
421 	 */
422 	if (!es->s_error_count)
423 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
424 	le32_add_cpu(&es->s_error_count, 1);
425 }
426 
427 static void save_error_info(struct super_block *sb, int error,
428 			    __u32 ino, __u64 block,
429 			    const char *func, unsigned int line)
430 {
431 	__save_error_info(sb, error, ino, block, func, line);
432 	if (!bdev_read_only(sb->s_bdev))
433 		ext4_commit_super(sb, 1);
434 }
435 
436 /*
437  * The del_gendisk() function uninitializes the disk-specific data
438  * structures, including the bdi structure, without telling anyone
439  * else.  Once this happens, any attempt to call mark_buffer_dirty()
440  * (for example, by ext4_commit_super), will cause a kernel OOPS.
441  * This is a kludge to prevent these oops until we can put in a proper
442  * hook in del_gendisk() to inform the VFS and file system layers.
443  */
444 static int block_device_ejected(struct super_block *sb)
445 {
446 	struct inode *bd_inode = sb->s_bdev->bd_inode;
447 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
448 
449 	return bdi->dev == NULL;
450 }
451 
452 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
453 {
454 	struct super_block		*sb = journal->j_private;
455 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
456 	int				error = is_journal_aborted(journal);
457 	struct ext4_journal_cb_entry	*jce;
458 
459 	BUG_ON(txn->t_state == T_FINISHED);
460 
461 	ext4_process_freed_data(sb, txn->t_tid);
462 
463 	spin_lock(&sbi->s_md_lock);
464 	while (!list_empty(&txn->t_private_list)) {
465 		jce = list_entry(txn->t_private_list.next,
466 				 struct ext4_journal_cb_entry, jce_list);
467 		list_del_init(&jce->jce_list);
468 		spin_unlock(&sbi->s_md_lock);
469 		jce->jce_func(sb, jce, error);
470 		spin_lock(&sbi->s_md_lock);
471 	}
472 	spin_unlock(&sbi->s_md_lock);
473 }
474 
475 static bool system_going_down(void)
476 {
477 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
478 		|| system_state == SYSTEM_RESTART;
479 }
480 
481 /* Deal with the reporting of failure conditions on a filesystem such as
482  * inconsistencies detected or read IO failures.
483  *
484  * On ext2, we can store the error state of the filesystem in the
485  * superblock.  That is not possible on ext4, because we may have other
486  * write ordering constraints on the superblock which prevent us from
487  * writing it out straight away; and given that the journal is about to
488  * be aborted, we can't rely on the current, or future, transactions to
489  * write out the superblock safely.
490  *
491  * We'll just use the jbd2_journal_abort() error code to record an error in
492  * the journal instead.  On recovery, the journal will complain about
493  * that error until we've noted it down and cleared it.
494  */
495 
496 static void ext4_handle_error(struct super_block *sb)
497 {
498 	if (test_opt(sb, WARN_ON_ERROR))
499 		WARN_ON_ONCE(1);
500 
501 	if (sb_rdonly(sb))
502 		return;
503 
504 	if (!test_opt(sb, ERRORS_CONT)) {
505 		journal_t *journal = EXT4_SB(sb)->s_journal;
506 
507 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
508 		if (journal)
509 			jbd2_journal_abort(journal, -EIO);
510 	}
511 	/*
512 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
513 	 * could panic during 'reboot -f' as the underlying device got already
514 	 * disabled.
515 	 */
516 	if (test_opt(sb, ERRORS_RO) || system_going_down()) {
517 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
518 		/*
519 		 * Make sure updated value of ->s_mount_flags will be visible
520 		 * before ->s_flags update
521 		 */
522 		smp_wmb();
523 		sb->s_flags |= SB_RDONLY;
524 	} else if (test_opt(sb, ERRORS_PANIC)) {
525 		panic("EXT4-fs (device %s): panic forced after error\n",
526 			sb->s_id);
527 	}
528 }
529 
530 #define ext4_error_ratelimit(sb)					\
531 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
532 			     "EXT4-fs error")
533 
534 void __ext4_error(struct super_block *sb, const char *function,
535 		  unsigned int line, int error, __u64 block,
536 		  const char *fmt, ...)
537 {
538 	struct va_format vaf;
539 	va_list args;
540 
541 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
542 		return;
543 
544 	trace_ext4_error(sb, function, line);
545 	if (ext4_error_ratelimit(sb)) {
546 		va_start(args, fmt);
547 		vaf.fmt = fmt;
548 		vaf.va = &args;
549 		printk(KERN_CRIT
550 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
551 		       sb->s_id, function, line, current->comm, &vaf);
552 		va_end(args);
553 	}
554 	save_error_info(sb, error, 0, block, function, line);
555 	ext4_handle_error(sb);
556 }
557 
558 void __ext4_error_inode(struct inode *inode, const char *function,
559 			unsigned int line, ext4_fsblk_t block, int error,
560 			const char *fmt, ...)
561 {
562 	va_list args;
563 	struct va_format vaf;
564 
565 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
566 		return;
567 
568 	trace_ext4_error(inode->i_sb, function, line);
569 	if (ext4_error_ratelimit(inode->i_sb)) {
570 		va_start(args, fmt);
571 		vaf.fmt = fmt;
572 		vaf.va = &args;
573 		if (block)
574 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
575 			       "inode #%lu: block %llu: comm %s: %pV\n",
576 			       inode->i_sb->s_id, function, line, inode->i_ino,
577 			       block, current->comm, &vaf);
578 		else
579 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
580 			       "inode #%lu: comm %s: %pV\n",
581 			       inode->i_sb->s_id, function, line, inode->i_ino,
582 			       current->comm, &vaf);
583 		va_end(args);
584 	}
585 	save_error_info(inode->i_sb, error, inode->i_ino, block,
586 			function, line);
587 	ext4_handle_error(inode->i_sb);
588 }
589 
590 void __ext4_error_file(struct file *file, const char *function,
591 		       unsigned int line, ext4_fsblk_t block,
592 		       const char *fmt, ...)
593 {
594 	va_list args;
595 	struct va_format vaf;
596 	struct inode *inode = file_inode(file);
597 	char pathname[80], *path;
598 
599 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
600 		return;
601 
602 	trace_ext4_error(inode->i_sb, function, line);
603 	if (ext4_error_ratelimit(inode->i_sb)) {
604 		path = file_path(file, pathname, sizeof(pathname));
605 		if (IS_ERR(path))
606 			path = "(unknown)";
607 		va_start(args, fmt);
608 		vaf.fmt = fmt;
609 		vaf.va = &args;
610 		if (block)
611 			printk(KERN_CRIT
612 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
613 			       "block %llu: comm %s: path %s: %pV\n",
614 			       inode->i_sb->s_id, function, line, inode->i_ino,
615 			       block, current->comm, path, &vaf);
616 		else
617 			printk(KERN_CRIT
618 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
619 			       "comm %s: path %s: %pV\n",
620 			       inode->i_sb->s_id, function, line, inode->i_ino,
621 			       current->comm, path, &vaf);
622 		va_end(args);
623 	}
624 	save_error_info(inode->i_sb, EFSCORRUPTED, inode->i_ino, block,
625 			function, line);
626 	ext4_handle_error(inode->i_sb);
627 }
628 
629 const char *ext4_decode_error(struct super_block *sb, int errno,
630 			      char nbuf[16])
631 {
632 	char *errstr = NULL;
633 
634 	switch (errno) {
635 	case -EFSCORRUPTED:
636 		errstr = "Corrupt filesystem";
637 		break;
638 	case -EFSBADCRC:
639 		errstr = "Filesystem failed CRC";
640 		break;
641 	case -EIO:
642 		errstr = "IO failure";
643 		break;
644 	case -ENOMEM:
645 		errstr = "Out of memory";
646 		break;
647 	case -EROFS:
648 		if (!sb || (EXT4_SB(sb)->s_journal &&
649 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
650 			errstr = "Journal has aborted";
651 		else
652 			errstr = "Readonly filesystem";
653 		break;
654 	default:
655 		/* If the caller passed in an extra buffer for unknown
656 		 * errors, textualise them now.  Else we just return
657 		 * NULL. */
658 		if (nbuf) {
659 			/* Check for truncated error codes... */
660 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
661 				errstr = nbuf;
662 		}
663 		break;
664 	}
665 
666 	return errstr;
667 }
668 
669 /* __ext4_std_error decodes expected errors from journaling functions
670  * automatically and invokes the appropriate error response.  */
671 
672 void __ext4_std_error(struct super_block *sb, const char *function,
673 		      unsigned int line, int errno)
674 {
675 	char nbuf[16];
676 	const char *errstr;
677 
678 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
679 		return;
680 
681 	/* Special case: if the error is EROFS, and we're not already
682 	 * inside a transaction, then there's really no point in logging
683 	 * an error. */
684 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
685 		return;
686 
687 	if (ext4_error_ratelimit(sb)) {
688 		errstr = ext4_decode_error(sb, errno, nbuf);
689 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
690 		       sb->s_id, function, line, errstr);
691 	}
692 
693 	save_error_info(sb, -errno, 0, 0, function, line);
694 	ext4_handle_error(sb);
695 }
696 
697 /*
698  * ext4_abort is a much stronger failure handler than ext4_error.  The
699  * abort function may be used to deal with unrecoverable failures such
700  * as journal IO errors or ENOMEM at a critical moment in log management.
701  *
702  * We unconditionally force the filesystem into an ABORT|READONLY state,
703  * unless the error response on the fs has been set to panic in which
704  * case we take the easy way out and panic immediately.
705  */
706 
707 void __ext4_abort(struct super_block *sb, const char *function,
708 		  unsigned int line, int error, const char *fmt, ...)
709 {
710 	struct va_format vaf;
711 	va_list args;
712 
713 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
714 		return;
715 
716 	save_error_info(sb, error, 0, 0, function, line);
717 	va_start(args, fmt);
718 	vaf.fmt = fmt;
719 	vaf.va = &args;
720 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
721 	       sb->s_id, function, line, &vaf);
722 	va_end(args);
723 
724 	if (sb_rdonly(sb) == 0) {
725 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
726 		if (EXT4_SB(sb)->s_journal)
727 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
728 
729 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
730 		/*
731 		 * Make sure updated value of ->s_mount_flags will be visible
732 		 * before ->s_flags update
733 		 */
734 		smp_wmb();
735 		sb->s_flags |= SB_RDONLY;
736 	}
737 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down())
738 		panic("EXT4-fs panic from previous error\n");
739 }
740 
741 void __ext4_msg(struct super_block *sb,
742 		const char *prefix, const char *fmt, ...)
743 {
744 	struct va_format vaf;
745 	va_list args;
746 
747 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
748 		return;
749 
750 	va_start(args, fmt);
751 	vaf.fmt = fmt;
752 	vaf.va = &args;
753 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
754 	va_end(args);
755 }
756 
757 #define ext4_warning_ratelimit(sb)					\
758 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
759 			     "EXT4-fs warning")
760 
761 void __ext4_warning(struct super_block *sb, const char *function,
762 		    unsigned int line, const char *fmt, ...)
763 {
764 	struct va_format vaf;
765 	va_list args;
766 
767 	if (!ext4_warning_ratelimit(sb))
768 		return;
769 
770 	va_start(args, fmt);
771 	vaf.fmt = fmt;
772 	vaf.va = &args;
773 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
774 	       sb->s_id, function, line, &vaf);
775 	va_end(args);
776 }
777 
778 void __ext4_warning_inode(const struct inode *inode, const char *function,
779 			  unsigned int line, const char *fmt, ...)
780 {
781 	struct va_format vaf;
782 	va_list args;
783 
784 	if (!ext4_warning_ratelimit(inode->i_sb))
785 		return;
786 
787 	va_start(args, fmt);
788 	vaf.fmt = fmt;
789 	vaf.va = &args;
790 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
791 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
792 	       function, line, inode->i_ino, current->comm, &vaf);
793 	va_end(args);
794 }
795 
796 void __ext4_grp_locked_error(const char *function, unsigned int line,
797 			     struct super_block *sb, ext4_group_t grp,
798 			     unsigned long ino, ext4_fsblk_t block,
799 			     const char *fmt, ...)
800 __releases(bitlock)
801 __acquires(bitlock)
802 {
803 	struct va_format vaf;
804 	va_list args;
805 
806 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
807 		return;
808 
809 	trace_ext4_error(sb, function, line);
810 	__save_error_info(sb, EFSCORRUPTED, ino, block, function, line);
811 
812 	if (ext4_error_ratelimit(sb)) {
813 		va_start(args, fmt);
814 		vaf.fmt = fmt;
815 		vaf.va = &args;
816 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
817 		       sb->s_id, function, line, grp);
818 		if (ino)
819 			printk(KERN_CONT "inode %lu: ", ino);
820 		if (block)
821 			printk(KERN_CONT "block %llu:",
822 			       (unsigned long long) block);
823 		printk(KERN_CONT "%pV\n", &vaf);
824 		va_end(args);
825 	}
826 
827 	if (test_opt(sb, WARN_ON_ERROR))
828 		WARN_ON_ONCE(1);
829 
830 	if (test_opt(sb, ERRORS_CONT)) {
831 		ext4_commit_super(sb, 0);
832 		return;
833 	}
834 
835 	ext4_unlock_group(sb, grp);
836 	ext4_commit_super(sb, 1);
837 	ext4_handle_error(sb);
838 	/*
839 	 * We only get here in the ERRORS_RO case; relocking the group
840 	 * may be dangerous, but nothing bad will happen since the
841 	 * filesystem will have already been marked read/only and the
842 	 * journal has been aborted.  We return 1 as a hint to callers
843 	 * who might what to use the return value from
844 	 * ext4_grp_locked_error() to distinguish between the
845 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
846 	 * aggressively from the ext4 function in question, with a
847 	 * more appropriate error code.
848 	 */
849 	ext4_lock_group(sb, grp);
850 	return;
851 }
852 
853 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
854 				     ext4_group_t group,
855 				     unsigned int flags)
856 {
857 	struct ext4_sb_info *sbi = EXT4_SB(sb);
858 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
859 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
860 	int ret;
861 
862 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
863 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
864 					    &grp->bb_state);
865 		if (!ret)
866 			percpu_counter_sub(&sbi->s_freeclusters_counter,
867 					   grp->bb_free);
868 	}
869 
870 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
871 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
872 					    &grp->bb_state);
873 		if (!ret && gdp) {
874 			int count;
875 
876 			count = ext4_free_inodes_count(sb, gdp);
877 			percpu_counter_sub(&sbi->s_freeinodes_counter,
878 					   count);
879 		}
880 	}
881 }
882 
883 void ext4_update_dynamic_rev(struct super_block *sb)
884 {
885 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
886 
887 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
888 		return;
889 
890 	ext4_warning(sb,
891 		     "updating to rev %d because of new feature flag, "
892 		     "running e2fsck is recommended",
893 		     EXT4_DYNAMIC_REV);
894 
895 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
896 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
897 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
898 	/* leave es->s_feature_*compat flags alone */
899 	/* es->s_uuid will be set by e2fsck if empty */
900 
901 	/*
902 	 * The rest of the superblock fields should be zero, and if not it
903 	 * means they are likely already in use, so leave them alone.  We
904 	 * can leave it up to e2fsck to clean up any inconsistencies there.
905 	 */
906 }
907 
908 /*
909  * Open the external journal device
910  */
911 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
912 {
913 	struct block_device *bdev;
914 
915 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
916 	if (IS_ERR(bdev))
917 		goto fail;
918 	return bdev;
919 
920 fail:
921 	ext4_msg(sb, KERN_ERR,
922 		 "failed to open journal device unknown-block(%u,%u) %ld",
923 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
924 	return NULL;
925 }
926 
927 /*
928  * Release the journal device
929  */
930 static void ext4_blkdev_put(struct block_device *bdev)
931 {
932 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
933 }
934 
935 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
936 {
937 	struct block_device *bdev;
938 	bdev = sbi->journal_bdev;
939 	if (bdev) {
940 		ext4_blkdev_put(bdev);
941 		sbi->journal_bdev = NULL;
942 	}
943 }
944 
945 static inline struct inode *orphan_list_entry(struct list_head *l)
946 {
947 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
948 }
949 
950 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
951 {
952 	struct list_head *l;
953 
954 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
955 		 le32_to_cpu(sbi->s_es->s_last_orphan));
956 
957 	printk(KERN_ERR "sb_info orphan list:\n");
958 	list_for_each(l, &sbi->s_orphan) {
959 		struct inode *inode = orphan_list_entry(l);
960 		printk(KERN_ERR "  "
961 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
962 		       inode->i_sb->s_id, inode->i_ino, inode,
963 		       inode->i_mode, inode->i_nlink,
964 		       NEXT_ORPHAN(inode));
965 	}
966 }
967 
968 #ifdef CONFIG_QUOTA
969 static int ext4_quota_off(struct super_block *sb, int type);
970 
971 static inline void ext4_quota_off_umount(struct super_block *sb)
972 {
973 	int type;
974 
975 	/* Use our quota_off function to clear inode flags etc. */
976 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
977 		ext4_quota_off(sb, type);
978 }
979 
980 /*
981  * This is a helper function which is used in the mount/remount
982  * codepaths (which holds s_umount) to fetch the quota file name.
983  */
984 static inline char *get_qf_name(struct super_block *sb,
985 				struct ext4_sb_info *sbi,
986 				int type)
987 {
988 	return rcu_dereference_protected(sbi->s_qf_names[type],
989 					 lockdep_is_held(&sb->s_umount));
990 }
991 #else
992 static inline void ext4_quota_off_umount(struct super_block *sb)
993 {
994 }
995 #endif
996 
997 static void ext4_put_super(struct super_block *sb)
998 {
999 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1000 	struct ext4_super_block *es = sbi->s_es;
1001 	struct buffer_head **group_desc;
1002 	struct flex_groups **flex_groups;
1003 	int aborted = 0;
1004 	int i, err;
1005 
1006 	ext4_unregister_li_request(sb);
1007 	ext4_quota_off_umount(sb);
1008 
1009 	destroy_workqueue(sbi->rsv_conversion_wq);
1010 
1011 	/*
1012 	 * Unregister sysfs before destroying jbd2 journal.
1013 	 * Since we could still access attr_journal_task attribute via sysfs
1014 	 * path which could have sbi->s_journal->j_task as NULL
1015 	 */
1016 	ext4_unregister_sysfs(sb);
1017 
1018 	if (sbi->s_journal) {
1019 		aborted = is_journal_aborted(sbi->s_journal);
1020 		err = jbd2_journal_destroy(sbi->s_journal);
1021 		sbi->s_journal = NULL;
1022 		if ((err < 0) && !aborted) {
1023 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1024 		}
1025 	}
1026 
1027 	ext4_es_unregister_shrinker(sbi);
1028 	del_timer_sync(&sbi->s_err_report);
1029 	ext4_release_system_zone(sb);
1030 	ext4_mb_release(sb);
1031 	ext4_ext_release(sb);
1032 
1033 	if (!sb_rdonly(sb) && !aborted) {
1034 		ext4_clear_feature_journal_needs_recovery(sb);
1035 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1036 	}
1037 	if (!sb_rdonly(sb))
1038 		ext4_commit_super(sb, 1);
1039 
1040 	rcu_read_lock();
1041 	group_desc = rcu_dereference(sbi->s_group_desc);
1042 	for (i = 0; i < sbi->s_gdb_count; i++)
1043 		brelse(group_desc[i]);
1044 	kvfree(group_desc);
1045 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1046 	if (flex_groups) {
1047 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1048 			kvfree(flex_groups[i]);
1049 		kvfree(flex_groups);
1050 	}
1051 	rcu_read_unlock();
1052 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1053 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1054 	percpu_counter_destroy(&sbi->s_dirs_counter);
1055 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1056 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1057 #ifdef CONFIG_QUOTA
1058 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1059 		kfree(get_qf_name(sb, sbi, i));
1060 #endif
1061 
1062 	/* Debugging code just in case the in-memory inode orphan list
1063 	 * isn't empty.  The on-disk one can be non-empty if we've
1064 	 * detected an error and taken the fs readonly, but the
1065 	 * in-memory list had better be clean by this point. */
1066 	if (!list_empty(&sbi->s_orphan))
1067 		dump_orphan_list(sb, sbi);
1068 	J_ASSERT(list_empty(&sbi->s_orphan));
1069 
1070 	sync_blockdev(sb->s_bdev);
1071 	invalidate_bdev(sb->s_bdev);
1072 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
1073 		/*
1074 		 * Invalidate the journal device's buffers.  We don't want them
1075 		 * floating about in memory - the physical journal device may
1076 		 * hotswapped, and it breaks the `ro-after' testing code.
1077 		 */
1078 		sync_blockdev(sbi->journal_bdev);
1079 		invalidate_bdev(sbi->journal_bdev);
1080 		ext4_blkdev_remove(sbi);
1081 	}
1082 
1083 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1084 	sbi->s_ea_inode_cache = NULL;
1085 
1086 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1087 	sbi->s_ea_block_cache = NULL;
1088 
1089 	if (sbi->s_mmp_tsk)
1090 		kthread_stop(sbi->s_mmp_tsk);
1091 	brelse(sbi->s_sbh);
1092 	sb->s_fs_info = NULL;
1093 	/*
1094 	 * Now that we are completely done shutting down the
1095 	 * superblock, we need to actually destroy the kobject.
1096 	 */
1097 	kobject_put(&sbi->s_kobj);
1098 	wait_for_completion(&sbi->s_kobj_unregister);
1099 	if (sbi->s_chksum_driver)
1100 		crypto_free_shash(sbi->s_chksum_driver);
1101 	kfree(sbi->s_blockgroup_lock);
1102 	fs_put_dax(sbi->s_daxdev);
1103 	fscrypt_free_dummy_context(&sbi->s_dummy_enc_ctx);
1104 #ifdef CONFIG_UNICODE
1105 	utf8_unload(sbi->s_encoding);
1106 #endif
1107 	kfree(sbi);
1108 }
1109 
1110 static struct kmem_cache *ext4_inode_cachep;
1111 
1112 /*
1113  * Called inside transaction, so use GFP_NOFS
1114  */
1115 static struct inode *ext4_alloc_inode(struct super_block *sb)
1116 {
1117 	struct ext4_inode_info *ei;
1118 
1119 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1120 	if (!ei)
1121 		return NULL;
1122 
1123 	inode_set_iversion(&ei->vfs_inode, 1);
1124 	spin_lock_init(&ei->i_raw_lock);
1125 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1126 	spin_lock_init(&ei->i_prealloc_lock);
1127 	ext4_es_init_tree(&ei->i_es_tree);
1128 	rwlock_init(&ei->i_es_lock);
1129 	INIT_LIST_HEAD(&ei->i_es_list);
1130 	ei->i_es_all_nr = 0;
1131 	ei->i_es_shk_nr = 0;
1132 	ei->i_es_shrink_lblk = 0;
1133 	ei->i_reserved_data_blocks = 0;
1134 	spin_lock_init(&(ei->i_block_reservation_lock));
1135 	ext4_init_pending_tree(&ei->i_pending_tree);
1136 #ifdef CONFIG_QUOTA
1137 	ei->i_reserved_quota = 0;
1138 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1139 #endif
1140 	ei->jinode = NULL;
1141 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1142 	spin_lock_init(&ei->i_completed_io_lock);
1143 	ei->i_sync_tid = 0;
1144 	ei->i_datasync_tid = 0;
1145 	atomic_set(&ei->i_unwritten, 0);
1146 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1147 	return &ei->vfs_inode;
1148 }
1149 
1150 static int ext4_drop_inode(struct inode *inode)
1151 {
1152 	int drop = generic_drop_inode(inode);
1153 
1154 	if (!drop)
1155 		drop = fscrypt_drop_inode(inode);
1156 
1157 	trace_ext4_drop_inode(inode, drop);
1158 	return drop;
1159 }
1160 
1161 static void ext4_free_in_core_inode(struct inode *inode)
1162 {
1163 	fscrypt_free_inode(inode);
1164 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1165 }
1166 
1167 static void ext4_destroy_inode(struct inode *inode)
1168 {
1169 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1170 		ext4_msg(inode->i_sb, KERN_ERR,
1171 			 "Inode %lu (%p): orphan list check failed!",
1172 			 inode->i_ino, EXT4_I(inode));
1173 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1174 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1175 				true);
1176 		dump_stack();
1177 	}
1178 }
1179 
1180 static void init_once(void *foo)
1181 {
1182 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1183 
1184 	INIT_LIST_HEAD(&ei->i_orphan);
1185 	init_rwsem(&ei->xattr_sem);
1186 	init_rwsem(&ei->i_data_sem);
1187 	init_rwsem(&ei->i_mmap_sem);
1188 	inode_init_once(&ei->vfs_inode);
1189 }
1190 
1191 static int __init init_inodecache(void)
1192 {
1193 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1194 				sizeof(struct ext4_inode_info), 0,
1195 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1196 					SLAB_ACCOUNT),
1197 				offsetof(struct ext4_inode_info, i_data),
1198 				sizeof_field(struct ext4_inode_info, i_data),
1199 				init_once);
1200 	if (ext4_inode_cachep == NULL)
1201 		return -ENOMEM;
1202 	return 0;
1203 }
1204 
1205 static void destroy_inodecache(void)
1206 {
1207 	/*
1208 	 * Make sure all delayed rcu free inodes are flushed before we
1209 	 * destroy cache.
1210 	 */
1211 	rcu_barrier();
1212 	kmem_cache_destroy(ext4_inode_cachep);
1213 }
1214 
1215 void ext4_clear_inode(struct inode *inode)
1216 {
1217 	invalidate_inode_buffers(inode);
1218 	clear_inode(inode);
1219 	ext4_discard_preallocations(inode);
1220 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1221 	dquot_drop(inode);
1222 	if (EXT4_I(inode)->jinode) {
1223 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1224 					       EXT4_I(inode)->jinode);
1225 		jbd2_free_inode(EXT4_I(inode)->jinode);
1226 		EXT4_I(inode)->jinode = NULL;
1227 	}
1228 	fscrypt_put_encryption_info(inode);
1229 	fsverity_cleanup_inode(inode);
1230 }
1231 
1232 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1233 					u64 ino, u32 generation)
1234 {
1235 	struct inode *inode;
1236 
1237 	/*
1238 	 * Currently we don't know the generation for parent directory, so
1239 	 * a generation of 0 means "accept any"
1240 	 */
1241 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1242 	if (IS_ERR(inode))
1243 		return ERR_CAST(inode);
1244 	if (generation && inode->i_generation != generation) {
1245 		iput(inode);
1246 		return ERR_PTR(-ESTALE);
1247 	}
1248 
1249 	return inode;
1250 }
1251 
1252 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1253 					int fh_len, int fh_type)
1254 {
1255 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1256 				    ext4_nfs_get_inode);
1257 }
1258 
1259 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1260 					int fh_len, int fh_type)
1261 {
1262 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1263 				    ext4_nfs_get_inode);
1264 }
1265 
1266 static int ext4_nfs_commit_metadata(struct inode *inode)
1267 {
1268 	struct writeback_control wbc = {
1269 		.sync_mode = WB_SYNC_ALL
1270 	};
1271 
1272 	trace_ext4_nfs_commit_metadata(inode);
1273 	return ext4_write_inode(inode, &wbc);
1274 }
1275 
1276 /*
1277  * Try to release metadata pages (indirect blocks, directories) which are
1278  * mapped via the block device.  Since these pages could have journal heads
1279  * which would prevent try_to_free_buffers() from freeing them, we must use
1280  * jbd2 layer's try_to_free_buffers() function to release them.
1281  */
1282 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1283 				 gfp_t wait)
1284 {
1285 	journal_t *journal = EXT4_SB(sb)->s_journal;
1286 
1287 	WARN_ON(PageChecked(page));
1288 	if (!page_has_buffers(page))
1289 		return 0;
1290 	if (journal)
1291 		return jbd2_journal_try_to_free_buffers(journal, page,
1292 						wait & ~__GFP_DIRECT_RECLAIM);
1293 	return try_to_free_buffers(page);
1294 }
1295 
1296 #ifdef CONFIG_FS_ENCRYPTION
1297 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1298 {
1299 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1300 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1301 }
1302 
1303 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1304 							void *fs_data)
1305 {
1306 	handle_t *handle = fs_data;
1307 	int res, res2, credits, retries = 0;
1308 
1309 	/*
1310 	 * Encrypting the root directory is not allowed because e2fsck expects
1311 	 * lost+found to exist and be unencrypted, and encrypting the root
1312 	 * directory would imply encrypting the lost+found directory as well as
1313 	 * the filename "lost+found" itself.
1314 	 */
1315 	if (inode->i_ino == EXT4_ROOT_INO)
1316 		return -EPERM;
1317 
1318 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1319 		return -EINVAL;
1320 
1321 	if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
1322 		return -EOPNOTSUPP;
1323 
1324 	res = ext4_convert_inline_data(inode);
1325 	if (res)
1326 		return res;
1327 
1328 	/*
1329 	 * If a journal handle was specified, then the encryption context is
1330 	 * being set on a new inode via inheritance and is part of a larger
1331 	 * transaction to create the inode.  Otherwise the encryption context is
1332 	 * being set on an existing inode in its own transaction.  Only in the
1333 	 * latter case should the "retry on ENOSPC" logic be used.
1334 	 */
1335 
1336 	if (handle) {
1337 		res = ext4_xattr_set_handle(handle, inode,
1338 					    EXT4_XATTR_INDEX_ENCRYPTION,
1339 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1340 					    ctx, len, 0);
1341 		if (!res) {
1342 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1343 			ext4_clear_inode_state(inode,
1344 					EXT4_STATE_MAY_INLINE_DATA);
1345 			/*
1346 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1347 			 * S_DAX may be disabled
1348 			 */
1349 			ext4_set_inode_flags(inode, false);
1350 		}
1351 		return res;
1352 	}
1353 
1354 	res = dquot_initialize(inode);
1355 	if (res)
1356 		return res;
1357 retry:
1358 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1359 				     &credits);
1360 	if (res)
1361 		return res;
1362 
1363 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1364 	if (IS_ERR(handle))
1365 		return PTR_ERR(handle);
1366 
1367 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1368 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1369 				    ctx, len, 0);
1370 	if (!res) {
1371 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1372 		/*
1373 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1374 		 * S_DAX may be disabled
1375 		 */
1376 		ext4_set_inode_flags(inode, false);
1377 		res = ext4_mark_inode_dirty(handle, inode);
1378 		if (res)
1379 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1380 	}
1381 	res2 = ext4_journal_stop(handle);
1382 
1383 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1384 		goto retry;
1385 	if (!res)
1386 		res = res2;
1387 	return res;
1388 }
1389 
1390 static const union fscrypt_context *
1391 ext4_get_dummy_context(struct super_block *sb)
1392 {
1393 	return EXT4_SB(sb)->s_dummy_enc_ctx.ctx;
1394 }
1395 
1396 static bool ext4_has_stable_inodes(struct super_block *sb)
1397 {
1398 	return ext4_has_feature_stable_inodes(sb);
1399 }
1400 
1401 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1402 				       int *ino_bits_ret, int *lblk_bits_ret)
1403 {
1404 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1405 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1406 }
1407 
1408 static const struct fscrypt_operations ext4_cryptops = {
1409 	.key_prefix		= "ext4:",
1410 	.get_context		= ext4_get_context,
1411 	.set_context		= ext4_set_context,
1412 	.get_dummy_context	= ext4_get_dummy_context,
1413 	.empty_dir		= ext4_empty_dir,
1414 	.max_namelen		= EXT4_NAME_LEN,
1415 	.has_stable_inodes	= ext4_has_stable_inodes,
1416 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1417 };
1418 #endif
1419 
1420 #ifdef CONFIG_QUOTA
1421 static const char * const quotatypes[] = INITQFNAMES;
1422 #define QTYPE2NAME(t) (quotatypes[t])
1423 
1424 static int ext4_write_dquot(struct dquot *dquot);
1425 static int ext4_acquire_dquot(struct dquot *dquot);
1426 static int ext4_release_dquot(struct dquot *dquot);
1427 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1428 static int ext4_write_info(struct super_block *sb, int type);
1429 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1430 			 const struct path *path);
1431 static int ext4_quota_on_mount(struct super_block *sb, int type);
1432 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1433 			       size_t len, loff_t off);
1434 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1435 				const char *data, size_t len, loff_t off);
1436 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1437 			     unsigned int flags);
1438 static int ext4_enable_quotas(struct super_block *sb);
1439 
1440 static struct dquot **ext4_get_dquots(struct inode *inode)
1441 {
1442 	return EXT4_I(inode)->i_dquot;
1443 }
1444 
1445 static const struct dquot_operations ext4_quota_operations = {
1446 	.get_reserved_space	= ext4_get_reserved_space,
1447 	.write_dquot		= ext4_write_dquot,
1448 	.acquire_dquot		= ext4_acquire_dquot,
1449 	.release_dquot		= ext4_release_dquot,
1450 	.mark_dirty		= ext4_mark_dquot_dirty,
1451 	.write_info		= ext4_write_info,
1452 	.alloc_dquot		= dquot_alloc,
1453 	.destroy_dquot		= dquot_destroy,
1454 	.get_projid		= ext4_get_projid,
1455 	.get_inode_usage	= ext4_get_inode_usage,
1456 	.get_next_id		= dquot_get_next_id,
1457 };
1458 
1459 static const struct quotactl_ops ext4_qctl_operations = {
1460 	.quota_on	= ext4_quota_on,
1461 	.quota_off	= ext4_quota_off,
1462 	.quota_sync	= dquot_quota_sync,
1463 	.get_state	= dquot_get_state,
1464 	.set_info	= dquot_set_dqinfo,
1465 	.get_dqblk	= dquot_get_dqblk,
1466 	.set_dqblk	= dquot_set_dqblk,
1467 	.get_nextdqblk	= dquot_get_next_dqblk,
1468 };
1469 #endif
1470 
1471 static const struct super_operations ext4_sops = {
1472 	.alloc_inode	= ext4_alloc_inode,
1473 	.free_inode	= ext4_free_in_core_inode,
1474 	.destroy_inode	= ext4_destroy_inode,
1475 	.write_inode	= ext4_write_inode,
1476 	.dirty_inode	= ext4_dirty_inode,
1477 	.drop_inode	= ext4_drop_inode,
1478 	.evict_inode	= ext4_evict_inode,
1479 	.put_super	= ext4_put_super,
1480 	.sync_fs	= ext4_sync_fs,
1481 	.freeze_fs	= ext4_freeze,
1482 	.unfreeze_fs	= ext4_unfreeze,
1483 	.statfs		= ext4_statfs,
1484 	.remount_fs	= ext4_remount,
1485 	.show_options	= ext4_show_options,
1486 #ifdef CONFIG_QUOTA
1487 	.quota_read	= ext4_quota_read,
1488 	.quota_write	= ext4_quota_write,
1489 	.get_dquots	= ext4_get_dquots,
1490 #endif
1491 	.bdev_try_to_free_page = bdev_try_to_free_page,
1492 };
1493 
1494 static const struct export_operations ext4_export_ops = {
1495 	.fh_to_dentry = ext4_fh_to_dentry,
1496 	.fh_to_parent = ext4_fh_to_parent,
1497 	.get_parent = ext4_get_parent,
1498 	.commit_metadata = ext4_nfs_commit_metadata,
1499 };
1500 
1501 enum {
1502 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1503 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1504 	Opt_nouid32, Opt_debug, Opt_removed,
1505 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1506 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1507 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1508 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1509 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1510 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1511 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1512 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1513 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1514 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1515 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1516 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1517 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1518 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1519 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1520 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1521 	Opt_dioread_nolock, Opt_dioread_lock,
1522 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1523 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1524 };
1525 
1526 static const match_table_t tokens = {
1527 	{Opt_bsd_df, "bsddf"},
1528 	{Opt_minix_df, "minixdf"},
1529 	{Opt_grpid, "grpid"},
1530 	{Opt_grpid, "bsdgroups"},
1531 	{Opt_nogrpid, "nogrpid"},
1532 	{Opt_nogrpid, "sysvgroups"},
1533 	{Opt_resgid, "resgid=%u"},
1534 	{Opt_resuid, "resuid=%u"},
1535 	{Opt_sb, "sb=%u"},
1536 	{Opt_err_cont, "errors=continue"},
1537 	{Opt_err_panic, "errors=panic"},
1538 	{Opt_err_ro, "errors=remount-ro"},
1539 	{Opt_nouid32, "nouid32"},
1540 	{Opt_debug, "debug"},
1541 	{Opt_removed, "oldalloc"},
1542 	{Opt_removed, "orlov"},
1543 	{Opt_user_xattr, "user_xattr"},
1544 	{Opt_nouser_xattr, "nouser_xattr"},
1545 	{Opt_acl, "acl"},
1546 	{Opt_noacl, "noacl"},
1547 	{Opt_noload, "norecovery"},
1548 	{Opt_noload, "noload"},
1549 	{Opt_removed, "nobh"},
1550 	{Opt_removed, "bh"},
1551 	{Opt_commit, "commit=%u"},
1552 	{Opt_min_batch_time, "min_batch_time=%u"},
1553 	{Opt_max_batch_time, "max_batch_time=%u"},
1554 	{Opt_journal_dev, "journal_dev=%u"},
1555 	{Opt_journal_path, "journal_path=%s"},
1556 	{Opt_journal_checksum, "journal_checksum"},
1557 	{Opt_nojournal_checksum, "nojournal_checksum"},
1558 	{Opt_journal_async_commit, "journal_async_commit"},
1559 	{Opt_abort, "abort"},
1560 	{Opt_data_journal, "data=journal"},
1561 	{Opt_data_ordered, "data=ordered"},
1562 	{Opt_data_writeback, "data=writeback"},
1563 	{Opt_data_err_abort, "data_err=abort"},
1564 	{Opt_data_err_ignore, "data_err=ignore"},
1565 	{Opt_offusrjquota, "usrjquota="},
1566 	{Opt_usrjquota, "usrjquota=%s"},
1567 	{Opt_offgrpjquota, "grpjquota="},
1568 	{Opt_grpjquota, "grpjquota=%s"},
1569 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1570 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1571 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1572 	{Opt_grpquota, "grpquota"},
1573 	{Opt_noquota, "noquota"},
1574 	{Opt_quota, "quota"},
1575 	{Opt_usrquota, "usrquota"},
1576 	{Opt_prjquota, "prjquota"},
1577 	{Opt_barrier, "barrier=%u"},
1578 	{Opt_barrier, "barrier"},
1579 	{Opt_nobarrier, "nobarrier"},
1580 	{Opt_i_version, "i_version"},
1581 	{Opt_dax, "dax"},
1582 	{Opt_dax_always, "dax=always"},
1583 	{Opt_dax_inode, "dax=inode"},
1584 	{Opt_dax_never, "dax=never"},
1585 	{Opt_stripe, "stripe=%u"},
1586 	{Opt_delalloc, "delalloc"},
1587 	{Opt_warn_on_error, "warn_on_error"},
1588 	{Opt_nowarn_on_error, "nowarn_on_error"},
1589 	{Opt_lazytime, "lazytime"},
1590 	{Opt_nolazytime, "nolazytime"},
1591 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1592 	{Opt_nodelalloc, "nodelalloc"},
1593 	{Opt_removed, "mblk_io_submit"},
1594 	{Opt_removed, "nomblk_io_submit"},
1595 	{Opt_block_validity, "block_validity"},
1596 	{Opt_noblock_validity, "noblock_validity"},
1597 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1598 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1599 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1600 	{Opt_auto_da_alloc, "auto_da_alloc"},
1601 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1602 	{Opt_dioread_nolock, "dioread_nolock"},
1603 	{Opt_dioread_lock, "nodioread_nolock"},
1604 	{Opt_dioread_lock, "dioread_lock"},
1605 	{Opt_discard, "discard"},
1606 	{Opt_nodiscard, "nodiscard"},
1607 	{Opt_init_itable, "init_itable=%u"},
1608 	{Opt_init_itable, "init_itable"},
1609 	{Opt_noinit_itable, "noinit_itable"},
1610 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1611 	{Opt_test_dummy_encryption, "test_dummy_encryption=%s"},
1612 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1613 	{Opt_nombcache, "nombcache"},
1614 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1615 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1616 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1617 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1618 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1619 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1620 	{Opt_err, NULL},
1621 };
1622 
1623 static ext4_fsblk_t get_sb_block(void **data)
1624 {
1625 	ext4_fsblk_t	sb_block;
1626 	char		*options = (char *) *data;
1627 
1628 	if (!options || strncmp(options, "sb=", 3) != 0)
1629 		return 1;	/* Default location */
1630 
1631 	options += 3;
1632 	/* TODO: use simple_strtoll with >32bit ext4 */
1633 	sb_block = simple_strtoul(options, &options, 0);
1634 	if (*options && *options != ',') {
1635 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1636 		       (char *) *data);
1637 		return 1;
1638 	}
1639 	if (*options == ',')
1640 		options++;
1641 	*data = (void *) options;
1642 
1643 	return sb_block;
1644 }
1645 
1646 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1647 static const char deprecated_msg[] =
1648 	"Mount option \"%s\" will be removed by %s\n"
1649 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1650 
1651 #ifdef CONFIG_QUOTA
1652 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1653 {
1654 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1655 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1656 	int ret = -1;
1657 
1658 	if (sb_any_quota_loaded(sb) && !old_qname) {
1659 		ext4_msg(sb, KERN_ERR,
1660 			"Cannot change journaled "
1661 			"quota options when quota turned on");
1662 		return -1;
1663 	}
1664 	if (ext4_has_feature_quota(sb)) {
1665 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1666 			 "ignored when QUOTA feature is enabled");
1667 		return 1;
1668 	}
1669 	qname = match_strdup(args);
1670 	if (!qname) {
1671 		ext4_msg(sb, KERN_ERR,
1672 			"Not enough memory for storing quotafile name");
1673 		return -1;
1674 	}
1675 	if (old_qname) {
1676 		if (strcmp(old_qname, qname) == 0)
1677 			ret = 1;
1678 		else
1679 			ext4_msg(sb, KERN_ERR,
1680 				 "%s quota file already specified",
1681 				 QTYPE2NAME(qtype));
1682 		goto errout;
1683 	}
1684 	if (strchr(qname, '/')) {
1685 		ext4_msg(sb, KERN_ERR,
1686 			"quotafile must be on filesystem root");
1687 		goto errout;
1688 	}
1689 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1690 	set_opt(sb, QUOTA);
1691 	return 1;
1692 errout:
1693 	kfree(qname);
1694 	return ret;
1695 }
1696 
1697 static int clear_qf_name(struct super_block *sb, int qtype)
1698 {
1699 
1700 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1701 	char *old_qname = get_qf_name(sb, sbi, qtype);
1702 
1703 	if (sb_any_quota_loaded(sb) && old_qname) {
1704 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1705 			" when quota turned on");
1706 		return -1;
1707 	}
1708 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1709 	synchronize_rcu();
1710 	kfree(old_qname);
1711 	return 1;
1712 }
1713 #endif
1714 
1715 #define MOPT_SET	0x0001
1716 #define MOPT_CLEAR	0x0002
1717 #define MOPT_NOSUPPORT	0x0004
1718 #define MOPT_EXPLICIT	0x0008
1719 #define MOPT_CLEAR_ERR	0x0010
1720 #define MOPT_GTE0	0x0020
1721 #ifdef CONFIG_QUOTA
1722 #define MOPT_Q		0
1723 #define MOPT_QFMT	0x0040
1724 #else
1725 #define MOPT_Q		MOPT_NOSUPPORT
1726 #define MOPT_QFMT	MOPT_NOSUPPORT
1727 #endif
1728 #define MOPT_DATAJ	0x0080
1729 #define MOPT_NO_EXT2	0x0100
1730 #define MOPT_NO_EXT3	0x0200
1731 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1732 #define MOPT_STRING	0x0400
1733 #define MOPT_SKIP	0x0800
1734 
1735 static const struct mount_opts {
1736 	int	token;
1737 	int	mount_opt;
1738 	int	flags;
1739 } ext4_mount_opts[] = {
1740 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1741 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1742 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1743 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1744 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1745 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1746 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1747 	 MOPT_EXT4_ONLY | MOPT_SET},
1748 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1749 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1750 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1751 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1752 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1753 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1754 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1755 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1756 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1757 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1758 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1759 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1760 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1761 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1762 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1763 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1764 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1765 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1766 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1767 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1768 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1769 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1770 	 MOPT_NO_EXT2},
1771 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1772 	 MOPT_NO_EXT2},
1773 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1774 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1775 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1776 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1777 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1778 	{Opt_commit, 0, MOPT_GTE0},
1779 	{Opt_max_batch_time, 0, MOPT_GTE0},
1780 	{Opt_min_batch_time, 0, MOPT_GTE0},
1781 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1782 	{Opt_init_itable, 0, MOPT_GTE0},
1783 	{Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP},
1784 	{Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS,
1785 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1786 	{Opt_dax_inode, EXT4_MOUNT2_DAX_INODE,
1787 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1788 	{Opt_dax_never, EXT4_MOUNT2_DAX_NEVER,
1789 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1790 	{Opt_stripe, 0, MOPT_GTE0},
1791 	{Opt_resuid, 0, MOPT_GTE0},
1792 	{Opt_resgid, 0, MOPT_GTE0},
1793 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1794 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1795 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1796 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1797 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1798 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1799 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1800 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1801 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1802 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1803 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1804 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1805 #else
1806 	{Opt_acl, 0, MOPT_NOSUPPORT},
1807 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1808 #endif
1809 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1810 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1811 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1812 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1813 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1814 							MOPT_SET | MOPT_Q},
1815 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1816 							MOPT_SET | MOPT_Q},
1817 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1818 							MOPT_SET | MOPT_Q},
1819 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1820 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1821 							MOPT_CLEAR | MOPT_Q},
1822 	{Opt_usrjquota, 0, MOPT_Q},
1823 	{Opt_grpjquota, 0, MOPT_Q},
1824 	{Opt_offusrjquota, 0, MOPT_Q},
1825 	{Opt_offgrpjquota, 0, MOPT_Q},
1826 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1827 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1828 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1829 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1830 	{Opt_test_dummy_encryption, 0, MOPT_STRING},
1831 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1832 	{Opt_err, 0, 0}
1833 };
1834 
1835 #ifdef CONFIG_UNICODE
1836 static const struct ext4_sb_encodings {
1837 	__u16 magic;
1838 	char *name;
1839 	char *version;
1840 } ext4_sb_encoding_map[] = {
1841 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
1842 };
1843 
1844 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
1845 				 const struct ext4_sb_encodings **encoding,
1846 				 __u16 *flags)
1847 {
1848 	__u16 magic = le16_to_cpu(es->s_encoding);
1849 	int i;
1850 
1851 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1852 		if (magic == ext4_sb_encoding_map[i].magic)
1853 			break;
1854 
1855 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
1856 		return -EINVAL;
1857 
1858 	*encoding = &ext4_sb_encoding_map[i];
1859 	*flags = le16_to_cpu(es->s_encoding_flags);
1860 
1861 	return 0;
1862 }
1863 #endif
1864 
1865 static int ext4_set_test_dummy_encryption(struct super_block *sb,
1866 					  const char *opt,
1867 					  const substring_t *arg,
1868 					  bool is_remount)
1869 {
1870 #ifdef CONFIG_FS_ENCRYPTION
1871 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1872 	int err;
1873 
1874 	/*
1875 	 * This mount option is just for testing, and it's not worthwhile to
1876 	 * implement the extra complexity (e.g. RCU protection) that would be
1877 	 * needed to allow it to be set or changed during remount.  We do allow
1878 	 * it to be specified during remount, but only if there is no change.
1879 	 */
1880 	if (is_remount && !sbi->s_dummy_enc_ctx.ctx) {
1881 		ext4_msg(sb, KERN_WARNING,
1882 			 "Can't set test_dummy_encryption on remount");
1883 		return -1;
1884 	}
1885 	err = fscrypt_set_test_dummy_encryption(sb, arg, &sbi->s_dummy_enc_ctx);
1886 	if (err) {
1887 		if (err == -EEXIST)
1888 			ext4_msg(sb, KERN_WARNING,
1889 				 "Can't change test_dummy_encryption on remount");
1890 		else if (err == -EINVAL)
1891 			ext4_msg(sb, KERN_WARNING,
1892 				 "Value of option \"%s\" is unrecognized", opt);
1893 		else
1894 			ext4_msg(sb, KERN_WARNING,
1895 				 "Error processing option \"%s\" [%d]",
1896 				 opt, err);
1897 		return -1;
1898 	}
1899 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
1900 #else
1901 	ext4_msg(sb, KERN_WARNING,
1902 		 "Test dummy encryption mount option ignored");
1903 #endif
1904 	return 1;
1905 }
1906 
1907 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1908 			    substring_t *args, unsigned long *journal_devnum,
1909 			    unsigned int *journal_ioprio, int is_remount)
1910 {
1911 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1912 	const struct mount_opts *m;
1913 	kuid_t uid;
1914 	kgid_t gid;
1915 	int arg = 0;
1916 
1917 #ifdef CONFIG_QUOTA
1918 	if (token == Opt_usrjquota)
1919 		return set_qf_name(sb, USRQUOTA, &args[0]);
1920 	else if (token == Opt_grpjquota)
1921 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1922 	else if (token == Opt_offusrjquota)
1923 		return clear_qf_name(sb, USRQUOTA);
1924 	else if (token == Opt_offgrpjquota)
1925 		return clear_qf_name(sb, GRPQUOTA);
1926 #endif
1927 	switch (token) {
1928 	case Opt_noacl:
1929 	case Opt_nouser_xattr:
1930 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1931 		break;
1932 	case Opt_sb:
1933 		return 1;	/* handled by get_sb_block() */
1934 	case Opt_removed:
1935 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1936 		return 1;
1937 	case Opt_abort:
1938 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1939 		return 1;
1940 	case Opt_i_version:
1941 		sb->s_flags |= SB_I_VERSION;
1942 		return 1;
1943 	case Opt_lazytime:
1944 		sb->s_flags |= SB_LAZYTIME;
1945 		return 1;
1946 	case Opt_nolazytime:
1947 		sb->s_flags &= ~SB_LAZYTIME;
1948 		return 1;
1949 	}
1950 
1951 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1952 		if (token == m->token)
1953 			break;
1954 
1955 	if (m->token == Opt_err) {
1956 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1957 			 "or missing value", opt);
1958 		return -1;
1959 	}
1960 
1961 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1962 		ext4_msg(sb, KERN_ERR,
1963 			 "Mount option \"%s\" incompatible with ext2", opt);
1964 		return -1;
1965 	}
1966 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1967 		ext4_msg(sb, KERN_ERR,
1968 			 "Mount option \"%s\" incompatible with ext3", opt);
1969 		return -1;
1970 	}
1971 
1972 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1973 		return -1;
1974 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1975 		return -1;
1976 	if (m->flags & MOPT_EXPLICIT) {
1977 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1978 			set_opt2(sb, EXPLICIT_DELALLOC);
1979 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1980 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1981 		} else
1982 			return -1;
1983 	}
1984 	if (m->flags & MOPT_CLEAR_ERR)
1985 		clear_opt(sb, ERRORS_MASK);
1986 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1987 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1988 			 "options when quota turned on");
1989 		return -1;
1990 	}
1991 
1992 	if (m->flags & MOPT_NOSUPPORT) {
1993 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1994 	} else if (token == Opt_commit) {
1995 		if (arg == 0)
1996 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1997 		else if (arg > INT_MAX / HZ) {
1998 			ext4_msg(sb, KERN_ERR,
1999 				 "Invalid commit interval %d, "
2000 				 "must be smaller than %d",
2001 				 arg, INT_MAX / HZ);
2002 			return -1;
2003 		}
2004 		sbi->s_commit_interval = HZ * arg;
2005 	} else if (token == Opt_debug_want_extra_isize) {
2006 		if ((arg & 1) ||
2007 		    (arg < 4) ||
2008 		    (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
2009 			ext4_msg(sb, KERN_ERR,
2010 				 "Invalid want_extra_isize %d", arg);
2011 			return -1;
2012 		}
2013 		sbi->s_want_extra_isize = arg;
2014 	} else if (token == Opt_max_batch_time) {
2015 		sbi->s_max_batch_time = arg;
2016 	} else if (token == Opt_min_batch_time) {
2017 		sbi->s_min_batch_time = arg;
2018 	} else if (token == Opt_inode_readahead_blks) {
2019 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
2020 			ext4_msg(sb, KERN_ERR,
2021 				 "EXT4-fs: inode_readahead_blks must be "
2022 				 "0 or a power of 2 smaller than 2^31");
2023 			return -1;
2024 		}
2025 		sbi->s_inode_readahead_blks = arg;
2026 	} else if (token == Opt_init_itable) {
2027 		set_opt(sb, INIT_INODE_TABLE);
2028 		if (!args->from)
2029 			arg = EXT4_DEF_LI_WAIT_MULT;
2030 		sbi->s_li_wait_mult = arg;
2031 	} else if (token == Opt_max_dir_size_kb) {
2032 		sbi->s_max_dir_size_kb = arg;
2033 	} else if (token == Opt_stripe) {
2034 		sbi->s_stripe = arg;
2035 	} else if (token == Opt_resuid) {
2036 		uid = make_kuid(current_user_ns(), arg);
2037 		if (!uid_valid(uid)) {
2038 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
2039 			return -1;
2040 		}
2041 		sbi->s_resuid = uid;
2042 	} else if (token == Opt_resgid) {
2043 		gid = make_kgid(current_user_ns(), arg);
2044 		if (!gid_valid(gid)) {
2045 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
2046 			return -1;
2047 		}
2048 		sbi->s_resgid = gid;
2049 	} else if (token == Opt_journal_dev) {
2050 		if (is_remount) {
2051 			ext4_msg(sb, KERN_ERR,
2052 				 "Cannot specify journal on remount");
2053 			return -1;
2054 		}
2055 		*journal_devnum = arg;
2056 	} else if (token == Opt_journal_path) {
2057 		char *journal_path;
2058 		struct inode *journal_inode;
2059 		struct path path;
2060 		int error;
2061 
2062 		if (is_remount) {
2063 			ext4_msg(sb, KERN_ERR,
2064 				 "Cannot specify journal on remount");
2065 			return -1;
2066 		}
2067 		journal_path = match_strdup(&args[0]);
2068 		if (!journal_path) {
2069 			ext4_msg(sb, KERN_ERR, "error: could not dup "
2070 				"journal device string");
2071 			return -1;
2072 		}
2073 
2074 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
2075 		if (error) {
2076 			ext4_msg(sb, KERN_ERR, "error: could not find "
2077 				"journal device path: error %d", error);
2078 			kfree(journal_path);
2079 			return -1;
2080 		}
2081 
2082 		journal_inode = d_inode(path.dentry);
2083 		if (!S_ISBLK(journal_inode->i_mode)) {
2084 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
2085 				"is not a block device", journal_path);
2086 			path_put(&path);
2087 			kfree(journal_path);
2088 			return -1;
2089 		}
2090 
2091 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
2092 		path_put(&path);
2093 		kfree(journal_path);
2094 	} else if (token == Opt_journal_ioprio) {
2095 		if (arg > 7) {
2096 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
2097 				 " (must be 0-7)");
2098 			return -1;
2099 		}
2100 		*journal_ioprio =
2101 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
2102 	} else if (token == Opt_test_dummy_encryption) {
2103 		return ext4_set_test_dummy_encryption(sb, opt, &args[0],
2104 						      is_remount);
2105 	} else if (m->flags & MOPT_DATAJ) {
2106 		if (is_remount) {
2107 			if (!sbi->s_journal)
2108 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2109 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2110 				ext4_msg(sb, KERN_ERR,
2111 					 "Cannot change data mode on remount");
2112 				return -1;
2113 			}
2114 		} else {
2115 			clear_opt(sb, DATA_FLAGS);
2116 			sbi->s_mount_opt |= m->mount_opt;
2117 		}
2118 #ifdef CONFIG_QUOTA
2119 	} else if (m->flags & MOPT_QFMT) {
2120 		if (sb_any_quota_loaded(sb) &&
2121 		    sbi->s_jquota_fmt != m->mount_opt) {
2122 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2123 				 "quota options when quota turned on");
2124 			return -1;
2125 		}
2126 		if (ext4_has_feature_quota(sb)) {
2127 			ext4_msg(sb, KERN_INFO,
2128 				 "Quota format mount options ignored "
2129 				 "when QUOTA feature is enabled");
2130 			return 1;
2131 		}
2132 		sbi->s_jquota_fmt = m->mount_opt;
2133 #endif
2134 	} else if (token == Opt_dax || token == Opt_dax_always ||
2135 		   token == Opt_dax_inode || token == Opt_dax_never) {
2136 #ifdef CONFIG_FS_DAX
2137 		switch (token) {
2138 		case Opt_dax:
2139 		case Opt_dax_always:
2140 			if (is_remount &&
2141 			    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2142 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2143 			fail_dax_change_remount:
2144 				ext4_msg(sb, KERN_ERR, "can't change "
2145 					 "dax mount option while remounting");
2146 				return -1;
2147 			}
2148 			if (is_remount &&
2149 			    (test_opt(sb, DATA_FLAGS) ==
2150 			     EXT4_MOUNT_JOURNAL_DATA)) {
2151 				    ext4_msg(sb, KERN_ERR, "can't mount with "
2152 					     "both data=journal and dax");
2153 				    return -1;
2154 			}
2155 			ext4_msg(sb, KERN_WARNING,
2156 				"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2157 			sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS;
2158 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2159 			break;
2160 		case Opt_dax_never:
2161 			if (is_remount &&
2162 			    (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2163 			     (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS)))
2164 				goto fail_dax_change_remount;
2165 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2166 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2167 			break;
2168 		case Opt_dax_inode:
2169 			if (is_remount &&
2170 			    ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2171 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2172 			     !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE)))
2173 				goto fail_dax_change_remount;
2174 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2175 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2176 			/* Strictly for printing options */
2177 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_INODE;
2178 			break;
2179 		}
2180 #else
2181 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2182 		sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2183 		sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2184 		return -1;
2185 #endif
2186 	} else if (token == Opt_data_err_abort) {
2187 		sbi->s_mount_opt |= m->mount_opt;
2188 	} else if (token == Opt_data_err_ignore) {
2189 		sbi->s_mount_opt &= ~m->mount_opt;
2190 	} else {
2191 		if (!args->from)
2192 			arg = 1;
2193 		if (m->flags & MOPT_CLEAR)
2194 			arg = !arg;
2195 		else if (unlikely(!(m->flags & MOPT_SET))) {
2196 			ext4_msg(sb, KERN_WARNING,
2197 				 "buggy handling of option %s", opt);
2198 			WARN_ON(1);
2199 			return -1;
2200 		}
2201 		if (arg != 0)
2202 			sbi->s_mount_opt |= m->mount_opt;
2203 		else
2204 			sbi->s_mount_opt &= ~m->mount_opt;
2205 	}
2206 	return 1;
2207 }
2208 
2209 static int parse_options(char *options, struct super_block *sb,
2210 			 unsigned long *journal_devnum,
2211 			 unsigned int *journal_ioprio,
2212 			 int is_remount)
2213 {
2214 	struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2215 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2216 	substring_t args[MAX_OPT_ARGS];
2217 	int token;
2218 
2219 	if (!options)
2220 		return 1;
2221 
2222 	while ((p = strsep(&options, ",")) != NULL) {
2223 		if (!*p)
2224 			continue;
2225 		/*
2226 		 * Initialize args struct so we know whether arg was
2227 		 * found; some options take optional arguments.
2228 		 */
2229 		args[0].to = args[0].from = NULL;
2230 		token = match_token(p, tokens, args);
2231 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2232 				     journal_ioprio, is_remount) < 0)
2233 			return 0;
2234 	}
2235 #ifdef CONFIG_QUOTA
2236 	/*
2237 	 * We do the test below only for project quotas. 'usrquota' and
2238 	 * 'grpquota' mount options are allowed even without quota feature
2239 	 * to support legacy quotas in quota files.
2240 	 */
2241 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2242 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2243 			 "Cannot enable project quota enforcement.");
2244 		return 0;
2245 	}
2246 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2247 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2248 	if (usr_qf_name || grp_qf_name) {
2249 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2250 			clear_opt(sb, USRQUOTA);
2251 
2252 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2253 			clear_opt(sb, GRPQUOTA);
2254 
2255 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2256 			ext4_msg(sb, KERN_ERR, "old and new quota "
2257 					"format mixing");
2258 			return 0;
2259 		}
2260 
2261 		if (!sbi->s_jquota_fmt) {
2262 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2263 					"not specified");
2264 			return 0;
2265 		}
2266 	}
2267 #endif
2268 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2269 		int blocksize =
2270 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2271 		if (blocksize < PAGE_SIZE)
2272 			ext4_msg(sb, KERN_WARNING, "Warning: mounting with an "
2273 				 "experimental mount option 'dioread_nolock' "
2274 				 "for blocksize < PAGE_SIZE");
2275 	}
2276 	return 1;
2277 }
2278 
2279 static inline void ext4_show_quota_options(struct seq_file *seq,
2280 					   struct super_block *sb)
2281 {
2282 #if defined(CONFIG_QUOTA)
2283 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2284 	char *usr_qf_name, *grp_qf_name;
2285 
2286 	if (sbi->s_jquota_fmt) {
2287 		char *fmtname = "";
2288 
2289 		switch (sbi->s_jquota_fmt) {
2290 		case QFMT_VFS_OLD:
2291 			fmtname = "vfsold";
2292 			break;
2293 		case QFMT_VFS_V0:
2294 			fmtname = "vfsv0";
2295 			break;
2296 		case QFMT_VFS_V1:
2297 			fmtname = "vfsv1";
2298 			break;
2299 		}
2300 		seq_printf(seq, ",jqfmt=%s", fmtname);
2301 	}
2302 
2303 	rcu_read_lock();
2304 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2305 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2306 	if (usr_qf_name)
2307 		seq_show_option(seq, "usrjquota", usr_qf_name);
2308 	if (grp_qf_name)
2309 		seq_show_option(seq, "grpjquota", grp_qf_name);
2310 	rcu_read_unlock();
2311 #endif
2312 }
2313 
2314 static const char *token2str(int token)
2315 {
2316 	const struct match_token *t;
2317 
2318 	for (t = tokens; t->token != Opt_err; t++)
2319 		if (t->token == token && !strchr(t->pattern, '='))
2320 			break;
2321 	return t->pattern;
2322 }
2323 
2324 /*
2325  * Show an option if
2326  *  - it's set to a non-default value OR
2327  *  - if the per-sb default is different from the global default
2328  */
2329 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2330 			      int nodefs)
2331 {
2332 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2333 	struct ext4_super_block *es = sbi->s_es;
2334 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2335 	const struct mount_opts *m;
2336 	char sep = nodefs ? '\n' : ',';
2337 
2338 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2339 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2340 
2341 	if (sbi->s_sb_block != 1)
2342 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2343 
2344 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2345 		int want_set = m->flags & MOPT_SET;
2346 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2347 		    (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP)
2348 			continue;
2349 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2350 			continue; /* skip if same as the default */
2351 		if ((want_set &&
2352 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2353 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2354 			continue; /* select Opt_noFoo vs Opt_Foo */
2355 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2356 	}
2357 
2358 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2359 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2360 		SEQ_OPTS_PRINT("resuid=%u",
2361 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2362 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2363 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2364 		SEQ_OPTS_PRINT("resgid=%u",
2365 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2366 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2367 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2368 		SEQ_OPTS_PUTS("errors=remount-ro");
2369 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2370 		SEQ_OPTS_PUTS("errors=continue");
2371 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2372 		SEQ_OPTS_PUTS("errors=panic");
2373 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2374 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2375 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2376 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2377 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2378 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2379 	if (sb->s_flags & SB_I_VERSION)
2380 		SEQ_OPTS_PUTS("i_version");
2381 	if (nodefs || sbi->s_stripe)
2382 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2383 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2384 			(sbi->s_mount_opt ^ def_mount_opt)) {
2385 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2386 			SEQ_OPTS_PUTS("data=journal");
2387 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2388 			SEQ_OPTS_PUTS("data=ordered");
2389 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2390 			SEQ_OPTS_PUTS("data=writeback");
2391 	}
2392 	if (nodefs ||
2393 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2394 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2395 			       sbi->s_inode_readahead_blks);
2396 
2397 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2398 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2399 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2400 	if (nodefs || sbi->s_max_dir_size_kb)
2401 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2402 	if (test_opt(sb, DATA_ERR_ABORT))
2403 		SEQ_OPTS_PUTS("data_err=abort");
2404 
2405 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2406 
2407 	if (test_opt(sb, DAX_ALWAYS)) {
2408 		if (IS_EXT2_SB(sb))
2409 			SEQ_OPTS_PUTS("dax");
2410 		else
2411 			SEQ_OPTS_PUTS("dax=always");
2412 	} else if (test_opt2(sb, DAX_NEVER)) {
2413 		SEQ_OPTS_PUTS("dax=never");
2414 	} else if (test_opt2(sb, DAX_INODE)) {
2415 		SEQ_OPTS_PUTS("dax=inode");
2416 	}
2417 
2418 	ext4_show_quota_options(seq, sb);
2419 	return 0;
2420 }
2421 
2422 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2423 {
2424 	return _ext4_show_options(seq, root->d_sb, 0);
2425 }
2426 
2427 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2428 {
2429 	struct super_block *sb = seq->private;
2430 	int rc;
2431 
2432 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2433 	rc = _ext4_show_options(seq, sb, 1);
2434 	seq_puts(seq, "\n");
2435 	return rc;
2436 }
2437 
2438 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2439 			    int read_only)
2440 {
2441 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2442 	int err = 0;
2443 
2444 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2445 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2446 			 "forcing read-only mode");
2447 		err = -EROFS;
2448 		goto done;
2449 	}
2450 	if (read_only)
2451 		goto done;
2452 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2453 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2454 			 "running e2fsck is recommended");
2455 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2456 		ext4_msg(sb, KERN_WARNING,
2457 			 "warning: mounting fs with errors, "
2458 			 "running e2fsck is recommended");
2459 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2460 		 le16_to_cpu(es->s_mnt_count) >=
2461 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2462 		ext4_msg(sb, KERN_WARNING,
2463 			 "warning: maximal mount count reached, "
2464 			 "running e2fsck is recommended");
2465 	else if (le32_to_cpu(es->s_checkinterval) &&
2466 		 (ext4_get_tstamp(es, s_lastcheck) +
2467 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2468 		ext4_msg(sb, KERN_WARNING,
2469 			 "warning: checktime reached, "
2470 			 "running e2fsck is recommended");
2471 	if (!sbi->s_journal)
2472 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2473 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2474 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2475 	le16_add_cpu(&es->s_mnt_count, 1);
2476 	ext4_update_tstamp(es, s_mtime);
2477 	if (sbi->s_journal)
2478 		ext4_set_feature_journal_needs_recovery(sb);
2479 
2480 	err = ext4_commit_super(sb, 1);
2481 done:
2482 	if (test_opt(sb, DEBUG))
2483 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2484 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2485 			sb->s_blocksize,
2486 			sbi->s_groups_count,
2487 			EXT4_BLOCKS_PER_GROUP(sb),
2488 			EXT4_INODES_PER_GROUP(sb),
2489 			sbi->s_mount_opt, sbi->s_mount_opt2);
2490 
2491 	cleancache_init_fs(sb);
2492 	return err;
2493 }
2494 
2495 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2496 {
2497 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2498 	struct flex_groups **old_groups, **new_groups;
2499 	int size, i, j;
2500 
2501 	if (!sbi->s_log_groups_per_flex)
2502 		return 0;
2503 
2504 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2505 	if (size <= sbi->s_flex_groups_allocated)
2506 		return 0;
2507 
2508 	new_groups = kvzalloc(roundup_pow_of_two(size *
2509 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
2510 	if (!new_groups) {
2511 		ext4_msg(sb, KERN_ERR,
2512 			 "not enough memory for %d flex group pointers", size);
2513 		return -ENOMEM;
2514 	}
2515 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2516 		new_groups[i] = kvzalloc(roundup_pow_of_two(
2517 					 sizeof(struct flex_groups)),
2518 					 GFP_KERNEL);
2519 		if (!new_groups[i]) {
2520 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
2521 				kvfree(new_groups[j]);
2522 			kvfree(new_groups);
2523 			ext4_msg(sb, KERN_ERR,
2524 				 "not enough memory for %d flex groups", size);
2525 			return -ENOMEM;
2526 		}
2527 	}
2528 	rcu_read_lock();
2529 	old_groups = rcu_dereference(sbi->s_flex_groups);
2530 	if (old_groups)
2531 		memcpy(new_groups, old_groups,
2532 		       (sbi->s_flex_groups_allocated *
2533 			sizeof(struct flex_groups *)));
2534 	rcu_read_unlock();
2535 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2536 	sbi->s_flex_groups_allocated = size;
2537 	if (old_groups)
2538 		ext4_kvfree_array_rcu(old_groups);
2539 	return 0;
2540 }
2541 
2542 static int ext4_fill_flex_info(struct super_block *sb)
2543 {
2544 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2545 	struct ext4_group_desc *gdp = NULL;
2546 	struct flex_groups *fg;
2547 	ext4_group_t flex_group;
2548 	int i, err;
2549 
2550 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2551 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2552 		sbi->s_log_groups_per_flex = 0;
2553 		return 1;
2554 	}
2555 
2556 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2557 	if (err)
2558 		goto failed;
2559 
2560 	for (i = 0; i < sbi->s_groups_count; i++) {
2561 		gdp = ext4_get_group_desc(sb, i, NULL);
2562 
2563 		flex_group = ext4_flex_group(sbi, i);
2564 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2565 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2566 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2567 			     &fg->free_clusters);
2568 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2569 	}
2570 
2571 	return 1;
2572 failed:
2573 	return 0;
2574 }
2575 
2576 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2577 				   struct ext4_group_desc *gdp)
2578 {
2579 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2580 	__u16 crc = 0;
2581 	__le32 le_group = cpu_to_le32(block_group);
2582 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2583 
2584 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2585 		/* Use new metadata_csum algorithm */
2586 		__u32 csum32;
2587 		__u16 dummy_csum = 0;
2588 
2589 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2590 				     sizeof(le_group));
2591 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2592 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2593 				     sizeof(dummy_csum));
2594 		offset += sizeof(dummy_csum);
2595 		if (offset < sbi->s_desc_size)
2596 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2597 					     sbi->s_desc_size - offset);
2598 
2599 		crc = csum32 & 0xFFFF;
2600 		goto out;
2601 	}
2602 
2603 	/* old crc16 code */
2604 	if (!ext4_has_feature_gdt_csum(sb))
2605 		return 0;
2606 
2607 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2608 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2609 	crc = crc16(crc, (__u8 *)gdp, offset);
2610 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2611 	/* for checksum of struct ext4_group_desc do the rest...*/
2612 	if (ext4_has_feature_64bit(sb) &&
2613 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2614 		crc = crc16(crc, (__u8 *)gdp + offset,
2615 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2616 				offset);
2617 
2618 out:
2619 	return cpu_to_le16(crc);
2620 }
2621 
2622 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2623 				struct ext4_group_desc *gdp)
2624 {
2625 	if (ext4_has_group_desc_csum(sb) &&
2626 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2627 		return 0;
2628 
2629 	return 1;
2630 }
2631 
2632 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2633 			      struct ext4_group_desc *gdp)
2634 {
2635 	if (!ext4_has_group_desc_csum(sb))
2636 		return;
2637 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2638 }
2639 
2640 /* Called at mount-time, super-block is locked */
2641 static int ext4_check_descriptors(struct super_block *sb,
2642 				  ext4_fsblk_t sb_block,
2643 				  ext4_group_t *first_not_zeroed)
2644 {
2645 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2646 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2647 	ext4_fsblk_t last_block;
2648 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2649 	ext4_fsblk_t block_bitmap;
2650 	ext4_fsblk_t inode_bitmap;
2651 	ext4_fsblk_t inode_table;
2652 	int flexbg_flag = 0;
2653 	ext4_group_t i, grp = sbi->s_groups_count;
2654 
2655 	if (ext4_has_feature_flex_bg(sb))
2656 		flexbg_flag = 1;
2657 
2658 	ext4_debug("Checking group descriptors");
2659 
2660 	for (i = 0; i < sbi->s_groups_count; i++) {
2661 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2662 
2663 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2664 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2665 		else
2666 			last_block = first_block +
2667 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2668 
2669 		if ((grp == sbi->s_groups_count) &&
2670 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2671 			grp = i;
2672 
2673 		block_bitmap = ext4_block_bitmap(sb, gdp);
2674 		if (block_bitmap == sb_block) {
2675 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2676 				 "Block bitmap for group %u overlaps "
2677 				 "superblock", i);
2678 			if (!sb_rdonly(sb))
2679 				return 0;
2680 		}
2681 		if (block_bitmap >= sb_block + 1 &&
2682 		    block_bitmap <= last_bg_block) {
2683 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2684 				 "Block bitmap for group %u overlaps "
2685 				 "block group descriptors", i);
2686 			if (!sb_rdonly(sb))
2687 				return 0;
2688 		}
2689 		if (block_bitmap < first_block || block_bitmap > last_block) {
2690 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2691 			       "Block bitmap for group %u not in group "
2692 			       "(block %llu)!", i, block_bitmap);
2693 			return 0;
2694 		}
2695 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2696 		if (inode_bitmap == sb_block) {
2697 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2698 				 "Inode bitmap for group %u overlaps "
2699 				 "superblock", i);
2700 			if (!sb_rdonly(sb))
2701 				return 0;
2702 		}
2703 		if (inode_bitmap >= sb_block + 1 &&
2704 		    inode_bitmap <= last_bg_block) {
2705 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2706 				 "Inode bitmap for group %u overlaps "
2707 				 "block group descriptors", i);
2708 			if (!sb_rdonly(sb))
2709 				return 0;
2710 		}
2711 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2712 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2713 			       "Inode bitmap for group %u not in group "
2714 			       "(block %llu)!", i, inode_bitmap);
2715 			return 0;
2716 		}
2717 		inode_table = ext4_inode_table(sb, gdp);
2718 		if (inode_table == sb_block) {
2719 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2720 				 "Inode table for group %u overlaps "
2721 				 "superblock", i);
2722 			if (!sb_rdonly(sb))
2723 				return 0;
2724 		}
2725 		if (inode_table >= sb_block + 1 &&
2726 		    inode_table <= last_bg_block) {
2727 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2728 				 "Inode table for group %u overlaps "
2729 				 "block group descriptors", i);
2730 			if (!sb_rdonly(sb))
2731 				return 0;
2732 		}
2733 		if (inode_table < first_block ||
2734 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2735 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2736 			       "Inode table for group %u not in group "
2737 			       "(block %llu)!", i, inode_table);
2738 			return 0;
2739 		}
2740 		ext4_lock_group(sb, i);
2741 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2742 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2743 				 "Checksum for group %u failed (%u!=%u)",
2744 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2745 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2746 			if (!sb_rdonly(sb)) {
2747 				ext4_unlock_group(sb, i);
2748 				return 0;
2749 			}
2750 		}
2751 		ext4_unlock_group(sb, i);
2752 		if (!flexbg_flag)
2753 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2754 	}
2755 	if (NULL != first_not_zeroed)
2756 		*first_not_zeroed = grp;
2757 	return 1;
2758 }
2759 
2760 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2761  * the superblock) which were deleted from all directories, but held open by
2762  * a process at the time of a crash.  We walk the list and try to delete these
2763  * inodes at recovery time (only with a read-write filesystem).
2764  *
2765  * In order to keep the orphan inode chain consistent during traversal (in
2766  * case of crash during recovery), we link each inode into the superblock
2767  * orphan list_head and handle it the same way as an inode deletion during
2768  * normal operation (which journals the operations for us).
2769  *
2770  * We only do an iget() and an iput() on each inode, which is very safe if we
2771  * accidentally point at an in-use or already deleted inode.  The worst that
2772  * can happen in this case is that we get a "bit already cleared" message from
2773  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2774  * e2fsck was run on this filesystem, and it must have already done the orphan
2775  * inode cleanup for us, so we can safely abort without any further action.
2776  */
2777 static void ext4_orphan_cleanup(struct super_block *sb,
2778 				struct ext4_super_block *es)
2779 {
2780 	unsigned int s_flags = sb->s_flags;
2781 	int ret, nr_orphans = 0, nr_truncates = 0;
2782 #ifdef CONFIG_QUOTA
2783 	int quota_update = 0;
2784 	int i;
2785 #endif
2786 	if (!es->s_last_orphan) {
2787 		jbd_debug(4, "no orphan inodes to clean up\n");
2788 		return;
2789 	}
2790 
2791 	if (bdev_read_only(sb->s_bdev)) {
2792 		ext4_msg(sb, KERN_ERR, "write access "
2793 			"unavailable, skipping orphan cleanup");
2794 		return;
2795 	}
2796 
2797 	/* Check if feature set would not allow a r/w mount */
2798 	if (!ext4_feature_set_ok(sb, 0)) {
2799 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2800 			 "unknown ROCOMPAT features");
2801 		return;
2802 	}
2803 
2804 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2805 		/* don't clear list on RO mount w/ errors */
2806 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2807 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2808 				  "clearing orphan list.\n");
2809 			es->s_last_orphan = 0;
2810 		}
2811 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2812 		return;
2813 	}
2814 
2815 	if (s_flags & SB_RDONLY) {
2816 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2817 		sb->s_flags &= ~SB_RDONLY;
2818 	}
2819 #ifdef CONFIG_QUOTA
2820 	/* Needed for iput() to work correctly and not trash data */
2821 	sb->s_flags |= SB_ACTIVE;
2822 
2823 	/*
2824 	 * Turn on quotas which were not enabled for read-only mounts if
2825 	 * filesystem has quota feature, so that they are updated correctly.
2826 	 */
2827 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2828 		int ret = ext4_enable_quotas(sb);
2829 
2830 		if (!ret)
2831 			quota_update = 1;
2832 		else
2833 			ext4_msg(sb, KERN_ERR,
2834 				"Cannot turn on quotas: error %d", ret);
2835 	}
2836 
2837 	/* Turn on journaled quotas used for old sytle */
2838 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2839 		if (EXT4_SB(sb)->s_qf_names[i]) {
2840 			int ret = ext4_quota_on_mount(sb, i);
2841 
2842 			if (!ret)
2843 				quota_update = 1;
2844 			else
2845 				ext4_msg(sb, KERN_ERR,
2846 					"Cannot turn on journaled "
2847 					"quota: type %d: error %d", i, ret);
2848 		}
2849 	}
2850 #endif
2851 
2852 	while (es->s_last_orphan) {
2853 		struct inode *inode;
2854 
2855 		/*
2856 		 * We may have encountered an error during cleanup; if
2857 		 * so, skip the rest.
2858 		 */
2859 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2860 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2861 			es->s_last_orphan = 0;
2862 			break;
2863 		}
2864 
2865 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2866 		if (IS_ERR(inode)) {
2867 			es->s_last_orphan = 0;
2868 			break;
2869 		}
2870 
2871 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2872 		dquot_initialize(inode);
2873 		if (inode->i_nlink) {
2874 			if (test_opt(sb, DEBUG))
2875 				ext4_msg(sb, KERN_DEBUG,
2876 					"%s: truncating inode %lu to %lld bytes",
2877 					__func__, inode->i_ino, inode->i_size);
2878 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2879 				  inode->i_ino, inode->i_size);
2880 			inode_lock(inode);
2881 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2882 			ret = ext4_truncate(inode);
2883 			if (ret)
2884 				ext4_std_error(inode->i_sb, ret);
2885 			inode_unlock(inode);
2886 			nr_truncates++;
2887 		} else {
2888 			if (test_opt(sb, DEBUG))
2889 				ext4_msg(sb, KERN_DEBUG,
2890 					"%s: deleting unreferenced inode %lu",
2891 					__func__, inode->i_ino);
2892 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2893 				  inode->i_ino);
2894 			nr_orphans++;
2895 		}
2896 		iput(inode);  /* The delete magic happens here! */
2897 	}
2898 
2899 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2900 
2901 	if (nr_orphans)
2902 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2903 		       PLURAL(nr_orphans));
2904 	if (nr_truncates)
2905 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2906 		       PLURAL(nr_truncates));
2907 #ifdef CONFIG_QUOTA
2908 	/* Turn off quotas if they were enabled for orphan cleanup */
2909 	if (quota_update) {
2910 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2911 			if (sb_dqopt(sb)->files[i])
2912 				dquot_quota_off(sb, i);
2913 		}
2914 	}
2915 #endif
2916 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2917 }
2918 
2919 /*
2920  * Maximal extent format file size.
2921  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2922  * extent format containers, within a sector_t, and within i_blocks
2923  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2924  * so that won't be a limiting factor.
2925  *
2926  * However there is other limiting factor. We do store extents in the form
2927  * of starting block and length, hence the resulting length of the extent
2928  * covering maximum file size must fit into on-disk format containers as
2929  * well. Given that length is always by 1 unit bigger than max unit (because
2930  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2931  *
2932  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2933  */
2934 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2935 {
2936 	loff_t res;
2937 	loff_t upper_limit = MAX_LFS_FILESIZE;
2938 
2939 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
2940 
2941 	if (!has_huge_files) {
2942 		upper_limit = (1LL << 32) - 1;
2943 
2944 		/* total blocks in file system block size */
2945 		upper_limit >>= (blkbits - 9);
2946 		upper_limit <<= blkbits;
2947 	}
2948 
2949 	/*
2950 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2951 	 * by one fs block, so ee_len can cover the extent of maximum file
2952 	 * size
2953 	 */
2954 	res = (1LL << 32) - 1;
2955 	res <<= blkbits;
2956 
2957 	/* Sanity check against vm- & vfs- imposed limits */
2958 	if (res > upper_limit)
2959 		res = upper_limit;
2960 
2961 	return res;
2962 }
2963 
2964 /*
2965  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2966  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2967  * We need to be 1 filesystem block less than the 2^48 sector limit.
2968  */
2969 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2970 {
2971 	loff_t res = EXT4_NDIR_BLOCKS;
2972 	int meta_blocks;
2973 	loff_t upper_limit;
2974 	/* This is calculated to be the largest file size for a dense, block
2975 	 * mapped file such that the file's total number of 512-byte sectors,
2976 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2977 	 *
2978 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2979 	 * number of 512-byte sectors of the file.
2980 	 */
2981 
2982 	if (!has_huge_files) {
2983 		/*
2984 		 * !has_huge_files or implies that the inode i_block field
2985 		 * represents total file blocks in 2^32 512-byte sectors ==
2986 		 * size of vfs inode i_blocks * 8
2987 		 */
2988 		upper_limit = (1LL << 32) - 1;
2989 
2990 		/* total blocks in file system block size */
2991 		upper_limit >>= (bits - 9);
2992 
2993 	} else {
2994 		/*
2995 		 * We use 48 bit ext4_inode i_blocks
2996 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2997 		 * represent total number of blocks in
2998 		 * file system block size
2999 		 */
3000 		upper_limit = (1LL << 48) - 1;
3001 
3002 	}
3003 
3004 	/* indirect blocks */
3005 	meta_blocks = 1;
3006 	/* double indirect blocks */
3007 	meta_blocks += 1 + (1LL << (bits-2));
3008 	/* tripple indirect blocks */
3009 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
3010 
3011 	upper_limit -= meta_blocks;
3012 	upper_limit <<= bits;
3013 
3014 	res += 1LL << (bits-2);
3015 	res += 1LL << (2*(bits-2));
3016 	res += 1LL << (3*(bits-2));
3017 	res <<= bits;
3018 	if (res > upper_limit)
3019 		res = upper_limit;
3020 
3021 	if (res > MAX_LFS_FILESIZE)
3022 		res = MAX_LFS_FILESIZE;
3023 
3024 	return res;
3025 }
3026 
3027 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3028 				   ext4_fsblk_t logical_sb_block, int nr)
3029 {
3030 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3031 	ext4_group_t bg, first_meta_bg;
3032 	int has_super = 0;
3033 
3034 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3035 
3036 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3037 		return logical_sb_block + nr + 1;
3038 	bg = sbi->s_desc_per_block * nr;
3039 	if (ext4_bg_has_super(sb, bg))
3040 		has_super = 1;
3041 
3042 	/*
3043 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3044 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3045 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3046 	 * compensate.
3047 	 */
3048 	if (sb->s_blocksize == 1024 && nr == 0 &&
3049 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3050 		has_super++;
3051 
3052 	return (has_super + ext4_group_first_block_no(sb, bg));
3053 }
3054 
3055 /**
3056  * ext4_get_stripe_size: Get the stripe size.
3057  * @sbi: In memory super block info
3058  *
3059  * If we have specified it via mount option, then
3060  * use the mount option value. If the value specified at mount time is
3061  * greater than the blocks per group use the super block value.
3062  * If the super block value is greater than blocks per group return 0.
3063  * Allocator needs it be less than blocks per group.
3064  *
3065  */
3066 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3067 {
3068 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3069 	unsigned long stripe_width =
3070 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3071 	int ret;
3072 
3073 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3074 		ret = sbi->s_stripe;
3075 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3076 		ret = stripe_width;
3077 	else if (stride && stride <= sbi->s_blocks_per_group)
3078 		ret = stride;
3079 	else
3080 		ret = 0;
3081 
3082 	/*
3083 	 * If the stripe width is 1, this makes no sense and
3084 	 * we set it to 0 to turn off stripe handling code.
3085 	 */
3086 	if (ret <= 1)
3087 		ret = 0;
3088 
3089 	return ret;
3090 }
3091 
3092 /*
3093  * Check whether this filesystem can be mounted based on
3094  * the features present and the RDONLY/RDWR mount requested.
3095  * Returns 1 if this filesystem can be mounted as requested,
3096  * 0 if it cannot be.
3097  */
3098 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
3099 {
3100 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3101 		ext4_msg(sb, KERN_ERR,
3102 			"Couldn't mount because of "
3103 			"unsupported optional features (%x)",
3104 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3105 			~EXT4_FEATURE_INCOMPAT_SUPP));
3106 		return 0;
3107 	}
3108 
3109 #ifndef CONFIG_UNICODE
3110 	if (ext4_has_feature_casefold(sb)) {
3111 		ext4_msg(sb, KERN_ERR,
3112 			 "Filesystem with casefold feature cannot be "
3113 			 "mounted without CONFIG_UNICODE");
3114 		return 0;
3115 	}
3116 #endif
3117 
3118 	if (readonly)
3119 		return 1;
3120 
3121 	if (ext4_has_feature_readonly(sb)) {
3122 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3123 		sb->s_flags |= SB_RDONLY;
3124 		return 1;
3125 	}
3126 
3127 	/* Check that feature set is OK for a read-write mount */
3128 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3129 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3130 			 "unsupported optional features (%x)",
3131 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3132 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3133 		return 0;
3134 	}
3135 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3136 		ext4_msg(sb, KERN_ERR,
3137 			 "Can't support bigalloc feature without "
3138 			 "extents feature\n");
3139 		return 0;
3140 	}
3141 
3142 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3143 	if (!readonly && (ext4_has_feature_quota(sb) ||
3144 			  ext4_has_feature_project(sb))) {
3145 		ext4_msg(sb, KERN_ERR,
3146 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3147 		return 0;
3148 	}
3149 #endif  /* CONFIG_QUOTA */
3150 	return 1;
3151 }
3152 
3153 /*
3154  * This function is called once a day if we have errors logged
3155  * on the file system
3156  */
3157 static void print_daily_error_info(struct timer_list *t)
3158 {
3159 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3160 	struct super_block *sb = sbi->s_sb;
3161 	struct ext4_super_block *es = sbi->s_es;
3162 
3163 	if (es->s_error_count)
3164 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3165 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3166 			 le32_to_cpu(es->s_error_count));
3167 	if (es->s_first_error_time) {
3168 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3169 		       sb->s_id,
3170 		       ext4_get_tstamp(es, s_first_error_time),
3171 		       (int) sizeof(es->s_first_error_func),
3172 		       es->s_first_error_func,
3173 		       le32_to_cpu(es->s_first_error_line));
3174 		if (es->s_first_error_ino)
3175 			printk(KERN_CONT ": inode %u",
3176 			       le32_to_cpu(es->s_first_error_ino));
3177 		if (es->s_first_error_block)
3178 			printk(KERN_CONT ": block %llu", (unsigned long long)
3179 			       le64_to_cpu(es->s_first_error_block));
3180 		printk(KERN_CONT "\n");
3181 	}
3182 	if (es->s_last_error_time) {
3183 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3184 		       sb->s_id,
3185 		       ext4_get_tstamp(es, s_last_error_time),
3186 		       (int) sizeof(es->s_last_error_func),
3187 		       es->s_last_error_func,
3188 		       le32_to_cpu(es->s_last_error_line));
3189 		if (es->s_last_error_ino)
3190 			printk(KERN_CONT ": inode %u",
3191 			       le32_to_cpu(es->s_last_error_ino));
3192 		if (es->s_last_error_block)
3193 			printk(KERN_CONT ": block %llu", (unsigned long long)
3194 			       le64_to_cpu(es->s_last_error_block));
3195 		printk(KERN_CONT "\n");
3196 	}
3197 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3198 }
3199 
3200 /* Find next suitable group and run ext4_init_inode_table */
3201 static int ext4_run_li_request(struct ext4_li_request *elr)
3202 {
3203 	struct ext4_group_desc *gdp = NULL;
3204 	ext4_group_t group, ngroups;
3205 	struct super_block *sb;
3206 	unsigned long timeout = 0;
3207 	int ret = 0;
3208 
3209 	sb = elr->lr_super;
3210 	ngroups = EXT4_SB(sb)->s_groups_count;
3211 
3212 	for (group = elr->lr_next_group; group < ngroups; group++) {
3213 		gdp = ext4_get_group_desc(sb, group, NULL);
3214 		if (!gdp) {
3215 			ret = 1;
3216 			break;
3217 		}
3218 
3219 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3220 			break;
3221 	}
3222 
3223 	if (group >= ngroups)
3224 		ret = 1;
3225 
3226 	if (!ret) {
3227 		timeout = jiffies;
3228 		ret = ext4_init_inode_table(sb, group,
3229 					    elr->lr_timeout ? 0 : 1);
3230 		if (elr->lr_timeout == 0) {
3231 			timeout = (jiffies - timeout) *
3232 				  elr->lr_sbi->s_li_wait_mult;
3233 			elr->lr_timeout = timeout;
3234 		}
3235 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3236 		elr->lr_next_group = group + 1;
3237 	}
3238 	return ret;
3239 }
3240 
3241 /*
3242  * Remove lr_request from the list_request and free the
3243  * request structure. Should be called with li_list_mtx held
3244  */
3245 static void ext4_remove_li_request(struct ext4_li_request *elr)
3246 {
3247 	struct ext4_sb_info *sbi;
3248 
3249 	if (!elr)
3250 		return;
3251 
3252 	sbi = elr->lr_sbi;
3253 
3254 	list_del(&elr->lr_request);
3255 	sbi->s_li_request = NULL;
3256 	kfree(elr);
3257 }
3258 
3259 static void ext4_unregister_li_request(struct super_block *sb)
3260 {
3261 	mutex_lock(&ext4_li_mtx);
3262 	if (!ext4_li_info) {
3263 		mutex_unlock(&ext4_li_mtx);
3264 		return;
3265 	}
3266 
3267 	mutex_lock(&ext4_li_info->li_list_mtx);
3268 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3269 	mutex_unlock(&ext4_li_info->li_list_mtx);
3270 	mutex_unlock(&ext4_li_mtx);
3271 }
3272 
3273 static struct task_struct *ext4_lazyinit_task;
3274 
3275 /*
3276  * This is the function where ext4lazyinit thread lives. It walks
3277  * through the request list searching for next scheduled filesystem.
3278  * When such a fs is found, run the lazy initialization request
3279  * (ext4_rn_li_request) and keep track of the time spend in this
3280  * function. Based on that time we compute next schedule time of
3281  * the request. When walking through the list is complete, compute
3282  * next waking time and put itself into sleep.
3283  */
3284 static int ext4_lazyinit_thread(void *arg)
3285 {
3286 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3287 	struct list_head *pos, *n;
3288 	struct ext4_li_request *elr;
3289 	unsigned long next_wakeup, cur;
3290 
3291 	BUG_ON(NULL == eli);
3292 
3293 cont_thread:
3294 	while (true) {
3295 		next_wakeup = MAX_JIFFY_OFFSET;
3296 
3297 		mutex_lock(&eli->li_list_mtx);
3298 		if (list_empty(&eli->li_request_list)) {
3299 			mutex_unlock(&eli->li_list_mtx);
3300 			goto exit_thread;
3301 		}
3302 		list_for_each_safe(pos, n, &eli->li_request_list) {
3303 			int err = 0;
3304 			int progress = 0;
3305 			elr = list_entry(pos, struct ext4_li_request,
3306 					 lr_request);
3307 
3308 			if (time_before(jiffies, elr->lr_next_sched)) {
3309 				if (time_before(elr->lr_next_sched, next_wakeup))
3310 					next_wakeup = elr->lr_next_sched;
3311 				continue;
3312 			}
3313 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3314 				if (sb_start_write_trylock(elr->lr_super)) {
3315 					progress = 1;
3316 					/*
3317 					 * We hold sb->s_umount, sb can not
3318 					 * be removed from the list, it is
3319 					 * now safe to drop li_list_mtx
3320 					 */
3321 					mutex_unlock(&eli->li_list_mtx);
3322 					err = ext4_run_li_request(elr);
3323 					sb_end_write(elr->lr_super);
3324 					mutex_lock(&eli->li_list_mtx);
3325 					n = pos->next;
3326 				}
3327 				up_read((&elr->lr_super->s_umount));
3328 			}
3329 			/* error, remove the lazy_init job */
3330 			if (err) {
3331 				ext4_remove_li_request(elr);
3332 				continue;
3333 			}
3334 			if (!progress) {
3335 				elr->lr_next_sched = jiffies +
3336 					(prandom_u32()
3337 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3338 			}
3339 			if (time_before(elr->lr_next_sched, next_wakeup))
3340 				next_wakeup = elr->lr_next_sched;
3341 		}
3342 		mutex_unlock(&eli->li_list_mtx);
3343 
3344 		try_to_freeze();
3345 
3346 		cur = jiffies;
3347 		if ((time_after_eq(cur, next_wakeup)) ||
3348 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3349 			cond_resched();
3350 			continue;
3351 		}
3352 
3353 		schedule_timeout_interruptible(next_wakeup - cur);
3354 
3355 		if (kthread_should_stop()) {
3356 			ext4_clear_request_list();
3357 			goto exit_thread;
3358 		}
3359 	}
3360 
3361 exit_thread:
3362 	/*
3363 	 * It looks like the request list is empty, but we need
3364 	 * to check it under the li_list_mtx lock, to prevent any
3365 	 * additions into it, and of course we should lock ext4_li_mtx
3366 	 * to atomically free the list and ext4_li_info, because at
3367 	 * this point another ext4 filesystem could be registering
3368 	 * new one.
3369 	 */
3370 	mutex_lock(&ext4_li_mtx);
3371 	mutex_lock(&eli->li_list_mtx);
3372 	if (!list_empty(&eli->li_request_list)) {
3373 		mutex_unlock(&eli->li_list_mtx);
3374 		mutex_unlock(&ext4_li_mtx);
3375 		goto cont_thread;
3376 	}
3377 	mutex_unlock(&eli->li_list_mtx);
3378 	kfree(ext4_li_info);
3379 	ext4_li_info = NULL;
3380 	mutex_unlock(&ext4_li_mtx);
3381 
3382 	return 0;
3383 }
3384 
3385 static void ext4_clear_request_list(void)
3386 {
3387 	struct list_head *pos, *n;
3388 	struct ext4_li_request *elr;
3389 
3390 	mutex_lock(&ext4_li_info->li_list_mtx);
3391 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3392 		elr = list_entry(pos, struct ext4_li_request,
3393 				 lr_request);
3394 		ext4_remove_li_request(elr);
3395 	}
3396 	mutex_unlock(&ext4_li_info->li_list_mtx);
3397 }
3398 
3399 static int ext4_run_lazyinit_thread(void)
3400 {
3401 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3402 					 ext4_li_info, "ext4lazyinit");
3403 	if (IS_ERR(ext4_lazyinit_task)) {
3404 		int err = PTR_ERR(ext4_lazyinit_task);
3405 		ext4_clear_request_list();
3406 		kfree(ext4_li_info);
3407 		ext4_li_info = NULL;
3408 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3409 				 "initialization thread\n",
3410 				 err);
3411 		return err;
3412 	}
3413 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3414 	return 0;
3415 }
3416 
3417 /*
3418  * Check whether it make sense to run itable init. thread or not.
3419  * If there is at least one uninitialized inode table, return
3420  * corresponding group number, else the loop goes through all
3421  * groups and return total number of groups.
3422  */
3423 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3424 {
3425 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3426 	struct ext4_group_desc *gdp = NULL;
3427 
3428 	if (!ext4_has_group_desc_csum(sb))
3429 		return ngroups;
3430 
3431 	for (group = 0; group < ngroups; group++) {
3432 		gdp = ext4_get_group_desc(sb, group, NULL);
3433 		if (!gdp)
3434 			continue;
3435 
3436 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3437 			break;
3438 	}
3439 
3440 	return group;
3441 }
3442 
3443 static int ext4_li_info_new(void)
3444 {
3445 	struct ext4_lazy_init *eli = NULL;
3446 
3447 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3448 	if (!eli)
3449 		return -ENOMEM;
3450 
3451 	INIT_LIST_HEAD(&eli->li_request_list);
3452 	mutex_init(&eli->li_list_mtx);
3453 
3454 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3455 
3456 	ext4_li_info = eli;
3457 
3458 	return 0;
3459 }
3460 
3461 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3462 					    ext4_group_t start)
3463 {
3464 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3465 	struct ext4_li_request *elr;
3466 
3467 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3468 	if (!elr)
3469 		return NULL;
3470 
3471 	elr->lr_super = sb;
3472 	elr->lr_sbi = sbi;
3473 	elr->lr_next_group = start;
3474 
3475 	/*
3476 	 * Randomize first schedule time of the request to
3477 	 * spread the inode table initialization requests
3478 	 * better.
3479 	 */
3480 	elr->lr_next_sched = jiffies + (prandom_u32() %
3481 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3482 	return elr;
3483 }
3484 
3485 int ext4_register_li_request(struct super_block *sb,
3486 			     ext4_group_t first_not_zeroed)
3487 {
3488 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3489 	struct ext4_li_request *elr = NULL;
3490 	ext4_group_t ngroups = sbi->s_groups_count;
3491 	int ret = 0;
3492 
3493 	mutex_lock(&ext4_li_mtx);
3494 	if (sbi->s_li_request != NULL) {
3495 		/*
3496 		 * Reset timeout so it can be computed again, because
3497 		 * s_li_wait_mult might have changed.
3498 		 */
3499 		sbi->s_li_request->lr_timeout = 0;
3500 		goto out;
3501 	}
3502 
3503 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3504 	    !test_opt(sb, INIT_INODE_TABLE))
3505 		goto out;
3506 
3507 	elr = ext4_li_request_new(sb, first_not_zeroed);
3508 	if (!elr) {
3509 		ret = -ENOMEM;
3510 		goto out;
3511 	}
3512 
3513 	if (NULL == ext4_li_info) {
3514 		ret = ext4_li_info_new();
3515 		if (ret)
3516 			goto out;
3517 	}
3518 
3519 	mutex_lock(&ext4_li_info->li_list_mtx);
3520 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3521 	mutex_unlock(&ext4_li_info->li_list_mtx);
3522 
3523 	sbi->s_li_request = elr;
3524 	/*
3525 	 * set elr to NULL here since it has been inserted to
3526 	 * the request_list and the removal and free of it is
3527 	 * handled by ext4_clear_request_list from now on.
3528 	 */
3529 	elr = NULL;
3530 
3531 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3532 		ret = ext4_run_lazyinit_thread();
3533 		if (ret)
3534 			goto out;
3535 	}
3536 out:
3537 	mutex_unlock(&ext4_li_mtx);
3538 	if (ret)
3539 		kfree(elr);
3540 	return ret;
3541 }
3542 
3543 /*
3544  * We do not need to lock anything since this is called on
3545  * module unload.
3546  */
3547 static void ext4_destroy_lazyinit_thread(void)
3548 {
3549 	/*
3550 	 * If thread exited earlier
3551 	 * there's nothing to be done.
3552 	 */
3553 	if (!ext4_li_info || !ext4_lazyinit_task)
3554 		return;
3555 
3556 	kthread_stop(ext4_lazyinit_task);
3557 }
3558 
3559 static int set_journal_csum_feature_set(struct super_block *sb)
3560 {
3561 	int ret = 1;
3562 	int compat, incompat;
3563 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3564 
3565 	if (ext4_has_metadata_csum(sb)) {
3566 		/* journal checksum v3 */
3567 		compat = 0;
3568 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3569 	} else {
3570 		/* journal checksum v1 */
3571 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3572 		incompat = 0;
3573 	}
3574 
3575 	jbd2_journal_clear_features(sbi->s_journal,
3576 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3577 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3578 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3579 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3580 		ret = jbd2_journal_set_features(sbi->s_journal,
3581 				compat, 0,
3582 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3583 				incompat);
3584 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3585 		ret = jbd2_journal_set_features(sbi->s_journal,
3586 				compat, 0,
3587 				incompat);
3588 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3589 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3590 	} else {
3591 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3592 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3593 	}
3594 
3595 	return ret;
3596 }
3597 
3598 /*
3599  * Note: calculating the overhead so we can be compatible with
3600  * historical BSD practice is quite difficult in the face of
3601  * clusters/bigalloc.  This is because multiple metadata blocks from
3602  * different block group can end up in the same allocation cluster.
3603  * Calculating the exact overhead in the face of clustered allocation
3604  * requires either O(all block bitmaps) in memory or O(number of block
3605  * groups**2) in time.  We will still calculate the superblock for
3606  * older file systems --- and if we come across with a bigalloc file
3607  * system with zero in s_overhead_clusters the estimate will be close to
3608  * correct especially for very large cluster sizes --- but for newer
3609  * file systems, it's better to calculate this figure once at mkfs
3610  * time, and store it in the superblock.  If the superblock value is
3611  * present (even for non-bigalloc file systems), we will use it.
3612  */
3613 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3614 			  char *buf)
3615 {
3616 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3617 	struct ext4_group_desc	*gdp;
3618 	ext4_fsblk_t		first_block, last_block, b;
3619 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3620 	int			s, j, count = 0;
3621 
3622 	if (!ext4_has_feature_bigalloc(sb))
3623 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3624 			sbi->s_itb_per_group + 2);
3625 
3626 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3627 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3628 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3629 	for (i = 0; i < ngroups; i++) {
3630 		gdp = ext4_get_group_desc(sb, i, NULL);
3631 		b = ext4_block_bitmap(sb, gdp);
3632 		if (b >= first_block && b <= last_block) {
3633 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3634 			count++;
3635 		}
3636 		b = ext4_inode_bitmap(sb, gdp);
3637 		if (b >= first_block && b <= last_block) {
3638 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3639 			count++;
3640 		}
3641 		b = ext4_inode_table(sb, gdp);
3642 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3643 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3644 				int c = EXT4_B2C(sbi, b - first_block);
3645 				ext4_set_bit(c, buf);
3646 				count++;
3647 			}
3648 		if (i != grp)
3649 			continue;
3650 		s = 0;
3651 		if (ext4_bg_has_super(sb, grp)) {
3652 			ext4_set_bit(s++, buf);
3653 			count++;
3654 		}
3655 		j = ext4_bg_num_gdb(sb, grp);
3656 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3657 			ext4_error(sb, "Invalid number of block group "
3658 				   "descriptor blocks: %d", j);
3659 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3660 		}
3661 		count += j;
3662 		for (; j > 0; j--)
3663 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3664 	}
3665 	if (!count)
3666 		return 0;
3667 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3668 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3669 }
3670 
3671 /*
3672  * Compute the overhead and stash it in sbi->s_overhead
3673  */
3674 int ext4_calculate_overhead(struct super_block *sb)
3675 {
3676 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3677 	struct ext4_super_block *es = sbi->s_es;
3678 	struct inode *j_inode;
3679 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3680 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3681 	ext4_fsblk_t overhead = 0;
3682 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3683 
3684 	if (!buf)
3685 		return -ENOMEM;
3686 
3687 	/*
3688 	 * Compute the overhead (FS structures).  This is constant
3689 	 * for a given filesystem unless the number of block groups
3690 	 * changes so we cache the previous value until it does.
3691 	 */
3692 
3693 	/*
3694 	 * All of the blocks before first_data_block are overhead
3695 	 */
3696 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3697 
3698 	/*
3699 	 * Add the overhead found in each block group
3700 	 */
3701 	for (i = 0; i < ngroups; i++) {
3702 		int blks;
3703 
3704 		blks = count_overhead(sb, i, buf);
3705 		overhead += blks;
3706 		if (blks)
3707 			memset(buf, 0, PAGE_SIZE);
3708 		cond_resched();
3709 	}
3710 
3711 	/*
3712 	 * Add the internal journal blocks whether the journal has been
3713 	 * loaded or not
3714 	 */
3715 	if (sbi->s_journal && !sbi->journal_bdev)
3716 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3717 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
3718 		/* j_inum for internal journal is non-zero */
3719 		j_inode = ext4_get_journal_inode(sb, j_inum);
3720 		if (j_inode) {
3721 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3722 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3723 			iput(j_inode);
3724 		} else {
3725 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3726 		}
3727 	}
3728 	sbi->s_overhead = overhead;
3729 	smp_wmb();
3730 	free_page((unsigned long) buf);
3731 	return 0;
3732 }
3733 
3734 static void ext4_set_resv_clusters(struct super_block *sb)
3735 {
3736 	ext4_fsblk_t resv_clusters;
3737 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3738 
3739 	/*
3740 	 * There's no need to reserve anything when we aren't using extents.
3741 	 * The space estimates are exact, there are no unwritten extents,
3742 	 * hole punching doesn't need new metadata... This is needed especially
3743 	 * to keep ext2/3 backward compatibility.
3744 	 */
3745 	if (!ext4_has_feature_extents(sb))
3746 		return;
3747 	/*
3748 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3749 	 * This should cover the situations where we can not afford to run
3750 	 * out of space like for example punch hole, or converting
3751 	 * unwritten extents in delalloc path. In most cases such
3752 	 * allocation would require 1, or 2 blocks, higher numbers are
3753 	 * very rare.
3754 	 */
3755 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3756 			 sbi->s_cluster_bits);
3757 
3758 	do_div(resv_clusters, 50);
3759 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3760 
3761 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3762 }
3763 
3764 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3765 {
3766 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3767 	char *orig_data = kstrdup(data, GFP_KERNEL);
3768 	struct buffer_head *bh, **group_desc;
3769 	struct ext4_super_block *es = NULL;
3770 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3771 	struct flex_groups **flex_groups;
3772 	ext4_fsblk_t block;
3773 	ext4_fsblk_t sb_block = get_sb_block(&data);
3774 	ext4_fsblk_t logical_sb_block;
3775 	unsigned long offset = 0;
3776 	unsigned long journal_devnum = 0;
3777 	unsigned long def_mount_opts;
3778 	struct inode *root;
3779 	const char *descr;
3780 	int ret = -ENOMEM;
3781 	int blocksize, clustersize;
3782 	unsigned int db_count;
3783 	unsigned int i;
3784 	int needs_recovery, has_huge_files;
3785 	__u64 blocks_count;
3786 	int err = 0;
3787 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3788 	ext4_group_t first_not_zeroed;
3789 
3790 	if ((data && !orig_data) || !sbi)
3791 		goto out_free_base;
3792 
3793 	sbi->s_daxdev = dax_dev;
3794 	sbi->s_blockgroup_lock =
3795 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3796 	if (!sbi->s_blockgroup_lock)
3797 		goto out_free_base;
3798 
3799 	sb->s_fs_info = sbi;
3800 	sbi->s_sb = sb;
3801 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3802 	sbi->s_sb_block = sb_block;
3803 	if (sb->s_bdev->bd_part)
3804 		sbi->s_sectors_written_start =
3805 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3806 
3807 	/* Cleanup superblock name */
3808 	strreplace(sb->s_id, '/', '!');
3809 
3810 	/* -EINVAL is default */
3811 	ret = -EINVAL;
3812 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3813 	if (!blocksize) {
3814 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3815 		goto out_fail;
3816 	}
3817 
3818 	/*
3819 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3820 	 * block sizes.  We need to calculate the offset from buffer start.
3821 	 */
3822 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3823 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3824 		offset = do_div(logical_sb_block, blocksize);
3825 	} else {
3826 		logical_sb_block = sb_block;
3827 	}
3828 
3829 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3830 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3831 		goto out_fail;
3832 	}
3833 	/*
3834 	 * Note: s_es must be initialized as soon as possible because
3835 	 *       some ext4 macro-instructions depend on its value
3836 	 */
3837 	es = (struct ext4_super_block *) (bh->b_data + offset);
3838 	sbi->s_es = es;
3839 	sb->s_magic = le16_to_cpu(es->s_magic);
3840 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3841 		goto cantfind_ext4;
3842 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3843 
3844 	/* Warn if metadata_csum and gdt_csum are both set. */
3845 	if (ext4_has_feature_metadata_csum(sb) &&
3846 	    ext4_has_feature_gdt_csum(sb))
3847 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3848 			     "redundant flags; please run fsck.");
3849 
3850 	/* Check for a known checksum algorithm */
3851 	if (!ext4_verify_csum_type(sb, es)) {
3852 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3853 			 "unknown checksum algorithm.");
3854 		silent = 1;
3855 		goto cantfind_ext4;
3856 	}
3857 
3858 	/* Load the checksum driver */
3859 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3860 	if (IS_ERR(sbi->s_chksum_driver)) {
3861 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3862 		ret = PTR_ERR(sbi->s_chksum_driver);
3863 		sbi->s_chksum_driver = NULL;
3864 		goto failed_mount;
3865 	}
3866 
3867 	/* Check superblock checksum */
3868 	if (!ext4_superblock_csum_verify(sb, es)) {
3869 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3870 			 "invalid superblock checksum.  Run e2fsck?");
3871 		silent = 1;
3872 		ret = -EFSBADCRC;
3873 		goto cantfind_ext4;
3874 	}
3875 
3876 	/* Precompute checksum seed for all metadata */
3877 	if (ext4_has_feature_csum_seed(sb))
3878 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3879 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3880 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3881 					       sizeof(es->s_uuid));
3882 
3883 	/* Set defaults before we parse the mount options */
3884 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3885 	set_opt(sb, INIT_INODE_TABLE);
3886 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3887 		set_opt(sb, DEBUG);
3888 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3889 		set_opt(sb, GRPID);
3890 	if (def_mount_opts & EXT4_DEFM_UID16)
3891 		set_opt(sb, NO_UID32);
3892 	/* xattr user namespace & acls are now defaulted on */
3893 	set_opt(sb, XATTR_USER);
3894 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3895 	set_opt(sb, POSIX_ACL);
3896 #endif
3897 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3898 	if (ext4_has_metadata_csum(sb))
3899 		set_opt(sb, JOURNAL_CHECKSUM);
3900 
3901 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3902 		set_opt(sb, JOURNAL_DATA);
3903 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3904 		set_opt(sb, ORDERED_DATA);
3905 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3906 		set_opt(sb, WRITEBACK_DATA);
3907 
3908 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3909 		set_opt(sb, ERRORS_PANIC);
3910 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3911 		set_opt(sb, ERRORS_CONT);
3912 	else
3913 		set_opt(sb, ERRORS_RO);
3914 	/* block_validity enabled by default; disable with noblock_validity */
3915 	set_opt(sb, BLOCK_VALIDITY);
3916 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3917 		set_opt(sb, DISCARD);
3918 
3919 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3920 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3921 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3922 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3923 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3924 
3925 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3926 		set_opt(sb, BARRIER);
3927 
3928 	/*
3929 	 * enable delayed allocation by default
3930 	 * Use -o nodelalloc to turn it off
3931 	 */
3932 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3933 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3934 		set_opt(sb, DELALLOC);
3935 
3936 	/*
3937 	 * set default s_li_wait_mult for lazyinit, for the case there is
3938 	 * no mount option specified.
3939 	 */
3940 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3941 
3942 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3943 
3944 	if (blocksize == PAGE_SIZE)
3945 		set_opt(sb, DIOREAD_NOLOCK);
3946 
3947 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3948 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3949 		ext4_msg(sb, KERN_ERR,
3950 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3951 			 blocksize, le32_to_cpu(es->s_log_block_size));
3952 		goto failed_mount;
3953 	}
3954 
3955 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3956 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3957 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3958 	} else {
3959 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3960 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3961 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3962 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3963 				 sbi->s_first_ino);
3964 			goto failed_mount;
3965 		}
3966 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3967 		    (!is_power_of_2(sbi->s_inode_size)) ||
3968 		    (sbi->s_inode_size > blocksize)) {
3969 			ext4_msg(sb, KERN_ERR,
3970 			       "unsupported inode size: %d",
3971 			       sbi->s_inode_size);
3972 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
3973 			goto failed_mount;
3974 		}
3975 		/*
3976 		 * i_atime_extra is the last extra field available for
3977 		 * [acm]times in struct ext4_inode. Checking for that
3978 		 * field should suffice to ensure we have extra space
3979 		 * for all three.
3980 		 */
3981 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
3982 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
3983 			sb->s_time_gran = 1;
3984 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
3985 		} else {
3986 			sb->s_time_gran = NSEC_PER_SEC;
3987 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
3988 		}
3989 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
3990 	}
3991 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3992 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3993 			EXT4_GOOD_OLD_INODE_SIZE;
3994 		if (ext4_has_feature_extra_isize(sb)) {
3995 			unsigned v, max = (sbi->s_inode_size -
3996 					   EXT4_GOOD_OLD_INODE_SIZE);
3997 
3998 			v = le16_to_cpu(es->s_want_extra_isize);
3999 			if (v > max) {
4000 				ext4_msg(sb, KERN_ERR,
4001 					 "bad s_want_extra_isize: %d", v);
4002 				goto failed_mount;
4003 			}
4004 			if (sbi->s_want_extra_isize < v)
4005 				sbi->s_want_extra_isize = v;
4006 
4007 			v = le16_to_cpu(es->s_min_extra_isize);
4008 			if (v > max) {
4009 				ext4_msg(sb, KERN_ERR,
4010 					 "bad s_min_extra_isize: %d", v);
4011 				goto failed_mount;
4012 			}
4013 			if (sbi->s_want_extra_isize < v)
4014 				sbi->s_want_extra_isize = v;
4015 		}
4016 	}
4017 
4018 	if (sbi->s_es->s_mount_opts[0]) {
4019 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
4020 					      sizeof(sbi->s_es->s_mount_opts),
4021 					      GFP_KERNEL);
4022 		if (!s_mount_opts)
4023 			goto failed_mount;
4024 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
4025 				   &journal_ioprio, 0)) {
4026 			ext4_msg(sb, KERN_WARNING,
4027 				 "failed to parse options in superblock: %s",
4028 				 s_mount_opts);
4029 		}
4030 		kfree(s_mount_opts);
4031 	}
4032 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4033 	if (!parse_options((char *) data, sb, &journal_devnum,
4034 			   &journal_ioprio, 0))
4035 		goto failed_mount;
4036 
4037 #ifdef CONFIG_UNICODE
4038 	if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
4039 		const struct ext4_sb_encodings *encoding_info;
4040 		struct unicode_map *encoding;
4041 		__u16 encoding_flags;
4042 
4043 		if (ext4_has_feature_encrypt(sb)) {
4044 			ext4_msg(sb, KERN_ERR,
4045 				 "Can't mount with encoding and encryption");
4046 			goto failed_mount;
4047 		}
4048 
4049 		if (ext4_sb_read_encoding(es, &encoding_info,
4050 					  &encoding_flags)) {
4051 			ext4_msg(sb, KERN_ERR,
4052 				 "Encoding requested by superblock is unknown");
4053 			goto failed_mount;
4054 		}
4055 
4056 		encoding = utf8_load(encoding_info->version);
4057 		if (IS_ERR(encoding)) {
4058 			ext4_msg(sb, KERN_ERR,
4059 				 "can't mount with superblock charset: %s-%s "
4060 				 "not supported by the kernel. flags: 0x%x.",
4061 				 encoding_info->name, encoding_info->version,
4062 				 encoding_flags);
4063 			goto failed_mount;
4064 		}
4065 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4066 			 "%s-%s with flags 0x%hx", encoding_info->name,
4067 			 encoding_info->version?:"\b", encoding_flags);
4068 
4069 		sbi->s_encoding = encoding;
4070 		sbi->s_encoding_flags = encoding_flags;
4071 	}
4072 #endif
4073 
4074 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4075 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, and O_DIRECT support!\n");
4076 		/* can't mount with both data=journal and dioread_nolock. */
4077 		clear_opt(sb, DIOREAD_NOLOCK);
4078 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4079 			ext4_msg(sb, KERN_ERR, "can't mount with "
4080 				 "both data=journal and delalloc");
4081 			goto failed_mount;
4082 		}
4083 		if (test_opt(sb, DAX_ALWAYS)) {
4084 			ext4_msg(sb, KERN_ERR, "can't mount with "
4085 				 "both data=journal and dax");
4086 			goto failed_mount;
4087 		}
4088 		if (ext4_has_feature_encrypt(sb)) {
4089 			ext4_msg(sb, KERN_WARNING,
4090 				 "encrypted files will use data=ordered "
4091 				 "instead of data journaling mode");
4092 		}
4093 		if (test_opt(sb, DELALLOC))
4094 			clear_opt(sb, DELALLOC);
4095 	} else {
4096 		sb->s_iflags |= SB_I_CGROUPWB;
4097 	}
4098 
4099 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4100 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4101 
4102 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4103 	    (ext4_has_compat_features(sb) ||
4104 	     ext4_has_ro_compat_features(sb) ||
4105 	     ext4_has_incompat_features(sb)))
4106 		ext4_msg(sb, KERN_WARNING,
4107 		       "feature flags set on rev 0 fs, "
4108 		       "running e2fsck is recommended");
4109 
4110 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4111 		set_opt2(sb, HURD_COMPAT);
4112 		if (ext4_has_feature_64bit(sb)) {
4113 			ext4_msg(sb, KERN_ERR,
4114 				 "The Hurd can't support 64-bit file systems");
4115 			goto failed_mount;
4116 		}
4117 
4118 		/*
4119 		 * ea_inode feature uses l_i_version field which is not
4120 		 * available in HURD_COMPAT mode.
4121 		 */
4122 		if (ext4_has_feature_ea_inode(sb)) {
4123 			ext4_msg(sb, KERN_ERR,
4124 				 "ea_inode feature is not supported for Hurd");
4125 			goto failed_mount;
4126 		}
4127 	}
4128 
4129 	if (IS_EXT2_SB(sb)) {
4130 		if (ext2_feature_set_ok(sb))
4131 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4132 				 "using the ext4 subsystem");
4133 		else {
4134 			/*
4135 			 * If we're probing be silent, if this looks like
4136 			 * it's actually an ext[34] filesystem.
4137 			 */
4138 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4139 				goto failed_mount;
4140 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4141 				 "to feature incompatibilities");
4142 			goto failed_mount;
4143 		}
4144 	}
4145 
4146 	if (IS_EXT3_SB(sb)) {
4147 		if (ext3_feature_set_ok(sb))
4148 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4149 				 "using the ext4 subsystem");
4150 		else {
4151 			/*
4152 			 * If we're probing be silent, if this looks like
4153 			 * it's actually an ext4 filesystem.
4154 			 */
4155 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4156 				goto failed_mount;
4157 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4158 				 "to feature incompatibilities");
4159 			goto failed_mount;
4160 		}
4161 	}
4162 
4163 	/*
4164 	 * Check feature flags regardless of the revision level, since we
4165 	 * previously didn't change the revision level when setting the flags,
4166 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4167 	 */
4168 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4169 		goto failed_mount;
4170 
4171 	if (le32_to_cpu(es->s_log_block_size) >
4172 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4173 		ext4_msg(sb, KERN_ERR,
4174 			 "Invalid log block size: %u",
4175 			 le32_to_cpu(es->s_log_block_size));
4176 		goto failed_mount;
4177 	}
4178 	if (le32_to_cpu(es->s_log_cluster_size) >
4179 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4180 		ext4_msg(sb, KERN_ERR,
4181 			 "Invalid log cluster size: %u",
4182 			 le32_to_cpu(es->s_log_cluster_size));
4183 		goto failed_mount;
4184 	}
4185 
4186 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4187 		ext4_msg(sb, KERN_ERR,
4188 			 "Number of reserved GDT blocks insanely large: %d",
4189 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4190 		goto failed_mount;
4191 	}
4192 
4193 	if (bdev_dax_supported(sb->s_bdev, blocksize))
4194 		set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4195 
4196 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4197 		if (ext4_has_feature_inline_data(sb)) {
4198 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4199 					" that may contain inline data");
4200 			goto failed_mount;
4201 		}
4202 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4203 			ext4_msg(sb, KERN_ERR,
4204 				"DAX unsupported by block device.");
4205 			goto failed_mount;
4206 		}
4207 	}
4208 
4209 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4210 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4211 			 es->s_encryption_level);
4212 		goto failed_mount;
4213 	}
4214 
4215 	if (sb->s_blocksize != blocksize) {
4216 		/* Validate the filesystem blocksize */
4217 		if (!sb_set_blocksize(sb, blocksize)) {
4218 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4219 					blocksize);
4220 			goto failed_mount;
4221 		}
4222 
4223 		brelse(bh);
4224 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4225 		offset = do_div(logical_sb_block, blocksize);
4226 		bh = sb_bread_unmovable(sb, logical_sb_block);
4227 		if (!bh) {
4228 			ext4_msg(sb, KERN_ERR,
4229 			       "Can't read superblock on 2nd try");
4230 			goto failed_mount;
4231 		}
4232 		es = (struct ext4_super_block *)(bh->b_data + offset);
4233 		sbi->s_es = es;
4234 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4235 			ext4_msg(sb, KERN_ERR,
4236 			       "Magic mismatch, very weird!");
4237 			goto failed_mount;
4238 		}
4239 	}
4240 
4241 	has_huge_files = ext4_has_feature_huge_file(sb);
4242 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4243 						      has_huge_files);
4244 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4245 
4246 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4247 	if (ext4_has_feature_64bit(sb)) {
4248 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4249 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4250 		    !is_power_of_2(sbi->s_desc_size)) {
4251 			ext4_msg(sb, KERN_ERR,
4252 			       "unsupported descriptor size %lu",
4253 			       sbi->s_desc_size);
4254 			goto failed_mount;
4255 		}
4256 	} else
4257 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4258 
4259 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4260 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4261 
4262 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4263 	if (sbi->s_inodes_per_block == 0)
4264 		goto cantfind_ext4;
4265 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4266 	    sbi->s_inodes_per_group > blocksize * 8) {
4267 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4268 			 sbi->s_inodes_per_group);
4269 		goto failed_mount;
4270 	}
4271 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4272 					sbi->s_inodes_per_block;
4273 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4274 	sbi->s_sbh = bh;
4275 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4276 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4277 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4278 
4279 	for (i = 0; i < 4; i++)
4280 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4281 	sbi->s_def_hash_version = es->s_def_hash_version;
4282 	if (ext4_has_feature_dir_index(sb)) {
4283 		i = le32_to_cpu(es->s_flags);
4284 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4285 			sbi->s_hash_unsigned = 3;
4286 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4287 #ifdef __CHAR_UNSIGNED__
4288 			if (!sb_rdonly(sb))
4289 				es->s_flags |=
4290 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4291 			sbi->s_hash_unsigned = 3;
4292 #else
4293 			if (!sb_rdonly(sb))
4294 				es->s_flags |=
4295 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4296 #endif
4297 		}
4298 	}
4299 
4300 	/* Handle clustersize */
4301 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4302 	if (ext4_has_feature_bigalloc(sb)) {
4303 		if (clustersize < blocksize) {
4304 			ext4_msg(sb, KERN_ERR,
4305 				 "cluster size (%d) smaller than "
4306 				 "block size (%d)", clustersize, blocksize);
4307 			goto failed_mount;
4308 		}
4309 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4310 			le32_to_cpu(es->s_log_block_size);
4311 		sbi->s_clusters_per_group =
4312 			le32_to_cpu(es->s_clusters_per_group);
4313 		if (sbi->s_clusters_per_group > blocksize * 8) {
4314 			ext4_msg(sb, KERN_ERR,
4315 				 "#clusters per group too big: %lu",
4316 				 sbi->s_clusters_per_group);
4317 			goto failed_mount;
4318 		}
4319 		if (sbi->s_blocks_per_group !=
4320 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4321 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4322 				 "clusters per group (%lu) inconsistent",
4323 				 sbi->s_blocks_per_group,
4324 				 sbi->s_clusters_per_group);
4325 			goto failed_mount;
4326 		}
4327 	} else {
4328 		if (clustersize != blocksize) {
4329 			ext4_msg(sb, KERN_ERR,
4330 				 "fragment/cluster size (%d) != "
4331 				 "block size (%d)", clustersize, blocksize);
4332 			goto failed_mount;
4333 		}
4334 		if (sbi->s_blocks_per_group > blocksize * 8) {
4335 			ext4_msg(sb, KERN_ERR,
4336 				 "#blocks per group too big: %lu",
4337 				 sbi->s_blocks_per_group);
4338 			goto failed_mount;
4339 		}
4340 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4341 		sbi->s_cluster_bits = 0;
4342 	}
4343 	sbi->s_cluster_ratio = clustersize / blocksize;
4344 
4345 	/* Do we have standard group size of clustersize * 8 blocks ? */
4346 	if (sbi->s_blocks_per_group == clustersize << 3)
4347 		set_opt2(sb, STD_GROUP_SIZE);
4348 
4349 	/*
4350 	 * Test whether we have more sectors than will fit in sector_t,
4351 	 * and whether the max offset is addressable by the page cache.
4352 	 */
4353 	err = generic_check_addressable(sb->s_blocksize_bits,
4354 					ext4_blocks_count(es));
4355 	if (err) {
4356 		ext4_msg(sb, KERN_ERR, "filesystem"
4357 			 " too large to mount safely on this system");
4358 		goto failed_mount;
4359 	}
4360 
4361 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4362 		goto cantfind_ext4;
4363 
4364 	/* check blocks count against device size */
4365 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4366 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4367 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4368 		       "exceeds size of device (%llu blocks)",
4369 		       ext4_blocks_count(es), blocks_count);
4370 		goto failed_mount;
4371 	}
4372 
4373 	/*
4374 	 * It makes no sense for the first data block to be beyond the end
4375 	 * of the filesystem.
4376 	 */
4377 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4378 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4379 			 "block %u is beyond end of filesystem (%llu)",
4380 			 le32_to_cpu(es->s_first_data_block),
4381 			 ext4_blocks_count(es));
4382 		goto failed_mount;
4383 	}
4384 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4385 	    (sbi->s_cluster_ratio == 1)) {
4386 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4387 			 "block is 0 with a 1k block and cluster size");
4388 		goto failed_mount;
4389 	}
4390 
4391 	blocks_count = (ext4_blocks_count(es) -
4392 			le32_to_cpu(es->s_first_data_block) +
4393 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4394 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4395 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4396 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4397 		       "(block count %llu, first data block %u, "
4398 		       "blocks per group %lu)", blocks_count,
4399 		       ext4_blocks_count(es),
4400 		       le32_to_cpu(es->s_first_data_block),
4401 		       EXT4_BLOCKS_PER_GROUP(sb));
4402 		goto failed_mount;
4403 	}
4404 	sbi->s_groups_count = blocks_count;
4405 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4406 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4407 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4408 	    le32_to_cpu(es->s_inodes_count)) {
4409 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4410 			 le32_to_cpu(es->s_inodes_count),
4411 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4412 		ret = -EINVAL;
4413 		goto failed_mount;
4414 	}
4415 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4416 		   EXT4_DESC_PER_BLOCK(sb);
4417 	if (ext4_has_feature_meta_bg(sb)) {
4418 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4419 			ext4_msg(sb, KERN_WARNING,
4420 				 "first meta block group too large: %u "
4421 				 "(group descriptor block count %u)",
4422 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4423 			goto failed_mount;
4424 		}
4425 	}
4426 	rcu_assign_pointer(sbi->s_group_desc,
4427 			   kvmalloc_array(db_count,
4428 					  sizeof(struct buffer_head *),
4429 					  GFP_KERNEL));
4430 	if (sbi->s_group_desc == NULL) {
4431 		ext4_msg(sb, KERN_ERR, "not enough memory");
4432 		ret = -ENOMEM;
4433 		goto failed_mount;
4434 	}
4435 
4436 	bgl_lock_init(sbi->s_blockgroup_lock);
4437 
4438 	/* Pre-read the descriptors into the buffer cache */
4439 	for (i = 0; i < db_count; i++) {
4440 		block = descriptor_loc(sb, logical_sb_block, i);
4441 		sb_breadahead_unmovable(sb, block);
4442 	}
4443 
4444 	for (i = 0; i < db_count; i++) {
4445 		struct buffer_head *bh;
4446 
4447 		block = descriptor_loc(sb, logical_sb_block, i);
4448 		bh = sb_bread_unmovable(sb, block);
4449 		if (!bh) {
4450 			ext4_msg(sb, KERN_ERR,
4451 			       "can't read group descriptor %d", i);
4452 			db_count = i;
4453 			goto failed_mount2;
4454 		}
4455 		rcu_read_lock();
4456 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4457 		rcu_read_unlock();
4458 	}
4459 	sbi->s_gdb_count = db_count;
4460 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4461 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4462 		ret = -EFSCORRUPTED;
4463 		goto failed_mount2;
4464 	}
4465 
4466 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4467 
4468 	/* Register extent status tree shrinker */
4469 	if (ext4_es_register_shrinker(sbi))
4470 		goto failed_mount3;
4471 
4472 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4473 	sbi->s_extent_max_zeroout_kb = 32;
4474 
4475 	/*
4476 	 * set up enough so that it can read an inode
4477 	 */
4478 	sb->s_op = &ext4_sops;
4479 	sb->s_export_op = &ext4_export_ops;
4480 	sb->s_xattr = ext4_xattr_handlers;
4481 #ifdef CONFIG_FS_ENCRYPTION
4482 	sb->s_cop = &ext4_cryptops;
4483 #endif
4484 #ifdef CONFIG_FS_VERITY
4485 	sb->s_vop = &ext4_verityops;
4486 #endif
4487 #ifdef CONFIG_QUOTA
4488 	sb->dq_op = &ext4_quota_operations;
4489 	if (ext4_has_feature_quota(sb))
4490 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4491 	else
4492 		sb->s_qcop = &ext4_qctl_operations;
4493 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4494 #endif
4495 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4496 
4497 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4498 	mutex_init(&sbi->s_orphan_lock);
4499 
4500 	sb->s_root = NULL;
4501 
4502 	needs_recovery = (es->s_last_orphan != 0 ||
4503 			  ext4_has_feature_journal_needs_recovery(sb));
4504 
4505 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4506 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4507 			goto failed_mount3a;
4508 
4509 	/*
4510 	 * The first inode we look at is the journal inode.  Don't try
4511 	 * root first: it may be modified in the journal!
4512 	 */
4513 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4514 		err = ext4_load_journal(sb, es, journal_devnum);
4515 		if (err)
4516 			goto failed_mount3a;
4517 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4518 		   ext4_has_feature_journal_needs_recovery(sb)) {
4519 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4520 		       "suppressed and not mounted read-only");
4521 		goto failed_mount_wq;
4522 	} else {
4523 		/* Nojournal mode, all journal mount options are illegal */
4524 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4525 			ext4_msg(sb, KERN_ERR, "can't mount with "
4526 				 "journal_checksum, fs mounted w/o journal");
4527 			goto failed_mount_wq;
4528 		}
4529 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4530 			ext4_msg(sb, KERN_ERR, "can't mount with "
4531 				 "journal_async_commit, fs mounted w/o journal");
4532 			goto failed_mount_wq;
4533 		}
4534 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4535 			ext4_msg(sb, KERN_ERR, "can't mount with "
4536 				 "commit=%lu, fs mounted w/o journal",
4537 				 sbi->s_commit_interval / HZ);
4538 			goto failed_mount_wq;
4539 		}
4540 		if (EXT4_MOUNT_DATA_FLAGS &
4541 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4542 			ext4_msg(sb, KERN_ERR, "can't mount with "
4543 				 "data=, fs mounted w/o journal");
4544 			goto failed_mount_wq;
4545 		}
4546 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4547 		clear_opt(sb, JOURNAL_CHECKSUM);
4548 		clear_opt(sb, DATA_FLAGS);
4549 		sbi->s_journal = NULL;
4550 		needs_recovery = 0;
4551 		goto no_journal;
4552 	}
4553 
4554 	if (ext4_has_feature_64bit(sb) &&
4555 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4556 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4557 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4558 		goto failed_mount_wq;
4559 	}
4560 
4561 	if (!set_journal_csum_feature_set(sb)) {
4562 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4563 			 "feature set");
4564 		goto failed_mount_wq;
4565 	}
4566 
4567 	/* We have now updated the journal if required, so we can
4568 	 * validate the data journaling mode. */
4569 	switch (test_opt(sb, DATA_FLAGS)) {
4570 	case 0:
4571 		/* No mode set, assume a default based on the journal
4572 		 * capabilities: ORDERED_DATA if the journal can
4573 		 * cope, else JOURNAL_DATA
4574 		 */
4575 		if (jbd2_journal_check_available_features
4576 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4577 			set_opt(sb, ORDERED_DATA);
4578 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4579 		} else {
4580 			set_opt(sb, JOURNAL_DATA);
4581 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4582 		}
4583 		break;
4584 
4585 	case EXT4_MOUNT_ORDERED_DATA:
4586 	case EXT4_MOUNT_WRITEBACK_DATA:
4587 		if (!jbd2_journal_check_available_features
4588 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4589 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4590 			       "requested data journaling mode");
4591 			goto failed_mount_wq;
4592 		}
4593 	default:
4594 		break;
4595 	}
4596 
4597 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4598 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4599 		ext4_msg(sb, KERN_ERR, "can't mount with "
4600 			"journal_async_commit in data=ordered mode");
4601 		goto failed_mount_wq;
4602 	}
4603 
4604 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4605 
4606 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4607 
4608 no_journal:
4609 	if (!test_opt(sb, NO_MBCACHE)) {
4610 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4611 		if (!sbi->s_ea_block_cache) {
4612 			ext4_msg(sb, KERN_ERR,
4613 				 "Failed to create ea_block_cache");
4614 			goto failed_mount_wq;
4615 		}
4616 
4617 		if (ext4_has_feature_ea_inode(sb)) {
4618 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4619 			if (!sbi->s_ea_inode_cache) {
4620 				ext4_msg(sb, KERN_ERR,
4621 					 "Failed to create ea_inode_cache");
4622 				goto failed_mount_wq;
4623 			}
4624 		}
4625 	}
4626 
4627 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4628 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4629 		goto failed_mount_wq;
4630 	}
4631 
4632 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4633 	    !ext4_has_feature_encrypt(sb)) {
4634 		ext4_set_feature_encrypt(sb);
4635 		ext4_commit_super(sb, 1);
4636 	}
4637 
4638 	/*
4639 	 * Get the # of file system overhead blocks from the
4640 	 * superblock if present.
4641 	 */
4642 	if (es->s_overhead_clusters)
4643 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4644 	else {
4645 		err = ext4_calculate_overhead(sb);
4646 		if (err)
4647 			goto failed_mount_wq;
4648 	}
4649 
4650 	/*
4651 	 * The maximum number of concurrent works can be high and
4652 	 * concurrency isn't really necessary.  Limit it to 1.
4653 	 */
4654 	EXT4_SB(sb)->rsv_conversion_wq =
4655 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4656 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4657 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4658 		ret = -ENOMEM;
4659 		goto failed_mount4;
4660 	}
4661 
4662 	/*
4663 	 * The jbd2_journal_load will have done any necessary log recovery,
4664 	 * so we can safely mount the rest of the filesystem now.
4665 	 */
4666 
4667 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4668 	if (IS_ERR(root)) {
4669 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4670 		ret = PTR_ERR(root);
4671 		root = NULL;
4672 		goto failed_mount4;
4673 	}
4674 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4675 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4676 		iput(root);
4677 		goto failed_mount4;
4678 	}
4679 
4680 #ifdef CONFIG_UNICODE
4681 	if (sbi->s_encoding)
4682 		sb->s_d_op = &ext4_dentry_ops;
4683 #endif
4684 
4685 	sb->s_root = d_make_root(root);
4686 	if (!sb->s_root) {
4687 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4688 		ret = -ENOMEM;
4689 		goto failed_mount4;
4690 	}
4691 
4692 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4693 	if (ret == -EROFS) {
4694 		sb->s_flags |= SB_RDONLY;
4695 		ret = 0;
4696 	} else if (ret)
4697 		goto failed_mount4a;
4698 
4699 	ext4_set_resv_clusters(sb);
4700 
4701 	err = ext4_setup_system_zone(sb);
4702 	if (err) {
4703 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4704 			 "zone (%d)", err);
4705 		goto failed_mount4a;
4706 	}
4707 
4708 	ext4_ext_init(sb);
4709 	err = ext4_mb_init(sb);
4710 	if (err) {
4711 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4712 			 err);
4713 		goto failed_mount5;
4714 	}
4715 
4716 	block = ext4_count_free_clusters(sb);
4717 	ext4_free_blocks_count_set(sbi->s_es,
4718 				   EXT4_C2B(sbi, block));
4719 	ext4_superblock_csum_set(sb);
4720 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4721 				  GFP_KERNEL);
4722 	if (!err) {
4723 		unsigned long freei = ext4_count_free_inodes(sb);
4724 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4725 		ext4_superblock_csum_set(sb);
4726 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4727 					  GFP_KERNEL);
4728 	}
4729 	if (!err)
4730 		err = percpu_counter_init(&sbi->s_dirs_counter,
4731 					  ext4_count_dirs(sb), GFP_KERNEL);
4732 	if (!err)
4733 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4734 					  GFP_KERNEL);
4735 	if (!err)
4736 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
4737 
4738 	if (err) {
4739 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4740 		goto failed_mount6;
4741 	}
4742 
4743 	if (ext4_has_feature_flex_bg(sb))
4744 		if (!ext4_fill_flex_info(sb)) {
4745 			ext4_msg(sb, KERN_ERR,
4746 			       "unable to initialize "
4747 			       "flex_bg meta info!");
4748 			goto failed_mount6;
4749 		}
4750 
4751 	err = ext4_register_li_request(sb, first_not_zeroed);
4752 	if (err)
4753 		goto failed_mount6;
4754 
4755 	err = ext4_register_sysfs(sb);
4756 	if (err)
4757 		goto failed_mount7;
4758 
4759 #ifdef CONFIG_QUOTA
4760 	/* Enable quota usage during mount. */
4761 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4762 		err = ext4_enable_quotas(sb);
4763 		if (err)
4764 			goto failed_mount8;
4765 	}
4766 #endif  /* CONFIG_QUOTA */
4767 
4768 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4769 	ext4_orphan_cleanup(sb, es);
4770 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4771 	if (needs_recovery) {
4772 		ext4_msg(sb, KERN_INFO, "recovery complete");
4773 		ext4_mark_recovery_complete(sb, es);
4774 	}
4775 	if (EXT4_SB(sb)->s_journal) {
4776 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4777 			descr = " journalled data mode";
4778 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4779 			descr = " ordered data mode";
4780 		else
4781 			descr = " writeback data mode";
4782 	} else
4783 		descr = "out journal";
4784 
4785 	if (test_opt(sb, DISCARD)) {
4786 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4787 		if (!blk_queue_discard(q))
4788 			ext4_msg(sb, KERN_WARNING,
4789 				 "mounting with \"discard\" option, but "
4790 				 "the device does not support discard");
4791 	}
4792 
4793 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4794 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4795 			 "Opts: %.*s%s%s", descr,
4796 			 (int) sizeof(sbi->s_es->s_mount_opts),
4797 			 sbi->s_es->s_mount_opts,
4798 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4799 
4800 	if (es->s_error_count)
4801 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4802 
4803 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4804 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4805 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4806 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4807 
4808 	kfree(orig_data);
4809 	return 0;
4810 
4811 cantfind_ext4:
4812 	if (!silent)
4813 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4814 	goto failed_mount;
4815 
4816 #ifdef CONFIG_QUOTA
4817 failed_mount8:
4818 	ext4_unregister_sysfs(sb);
4819 #endif
4820 failed_mount7:
4821 	ext4_unregister_li_request(sb);
4822 failed_mount6:
4823 	ext4_mb_release(sb);
4824 	rcu_read_lock();
4825 	flex_groups = rcu_dereference(sbi->s_flex_groups);
4826 	if (flex_groups) {
4827 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
4828 			kvfree(flex_groups[i]);
4829 		kvfree(flex_groups);
4830 	}
4831 	rcu_read_unlock();
4832 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4833 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4834 	percpu_counter_destroy(&sbi->s_dirs_counter);
4835 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4836 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
4837 failed_mount5:
4838 	ext4_ext_release(sb);
4839 	ext4_release_system_zone(sb);
4840 failed_mount4a:
4841 	dput(sb->s_root);
4842 	sb->s_root = NULL;
4843 failed_mount4:
4844 	ext4_msg(sb, KERN_ERR, "mount failed");
4845 	if (EXT4_SB(sb)->rsv_conversion_wq)
4846 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4847 failed_mount_wq:
4848 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4849 	sbi->s_ea_inode_cache = NULL;
4850 
4851 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4852 	sbi->s_ea_block_cache = NULL;
4853 
4854 	if (sbi->s_journal) {
4855 		jbd2_journal_destroy(sbi->s_journal);
4856 		sbi->s_journal = NULL;
4857 	}
4858 failed_mount3a:
4859 	ext4_es_unregister_shrinker(sbi);
4860 failed_mount3:
4861 	del_timer_sync(&sbi->s_err_report);
4862 	if (sbi->s_mmp_tsk)
4863 		kthread_stop(sbi->s_mmp_tsk);
4864 failed_mount2:
4865 	rcu_read_lock();
4866 	group_desc = rcu_dereference(sbi->s_group_desc);
4867 	for (i = 0; i < db_count; i++)
4868 		brelse(group_desc[i]);
4869 	kvfree(group_desc);
4870 	rcu_read_unlock();
4871 failed_mount:
4872 	if (sbi->s_chksum_driver)
4873 		crypto_free_shash(sbi->s_chksum_driver);
4874 
4875 #ifdef CONFIG_UNICODE
4876 	utf8_unload(sbi->s_encoding);
4877 #endif
4878 
4879 #ifdef CONFIG_QUOTA
4880 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4881 		kfree(get_qf_name(sb, sbi, i));
4882 #endif
4883 	fscrypt_free_dummy_context(&sbi->s_dummy_enc_ctx);
4884 	ext4_blkdev_remove(sbi);
4885 	brelse(bh);
4886 out_fail:
4887 	sb->s_fs_info = NULL;
4888 	kfree(sbi->s_blockgroup_lock);
4889 out_free_base:
4890 	kfree(sbi);
4891 	kfree(orig_data);
4892 	fs_put_dax(dax_dev);
4893 	return err ? err : ret;
4894 }
4895 
4896 /*
4897  * Setup any per-fs journal parameters now.  We'll do this both on
4898  * initial mount, once the journal has been initialised but before we've
4899  * done any recovery; and again on any subsequent remount.
4900  */
4901 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4902 {
4903 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4904 
4905 	journal->j_commit_interval = sbi->s_commit_interval;
4906 	journal->j_min_batch_time = sbi->s_min_batch_time;
4907 	journal->j_max_batch_time = sbi->s_max_batch_time;
4908 
4909 	write_lock(&journal->j_state_lock);
4910 	if (test_opt(sb, BARRIER))
4911 		journal->j_flags |= JBD2_BARRIER;
4912 	else
4913 		journal->j_flags &= ~JBD2_BARRIER;
4914 	if (test_opt(sb, DATA_ERR_ABORT))
4915 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4916 	else
4917 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4918 	write_unlock(&journal->j_state_lock);
4919 }
4920 
4921 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4922 					     unsigned int journal_inum)
4923 {
4924 	struct inode *journal_inode;
4925 
4926 	/*
4927 	 * Test for the existence of a valid inode on disk.  Bad things
4928 	 * happen if we iget() an unused inode, as the subsequent iput()
4929 	 * will try to delete it.
4930 	 */
4931 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4932 	if (IS_ERR(journal_inode)) {
4933 		ext4_msg(sb, KERN_ERR, "no journal found");
4934 		return NULL;
4935 	}
4936 	if (!journal_inode->i_nlink) {
4937 		make_bad_inode(journal_inode);
4938 		iput(journal_inode);
4939 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4940 		return NULL;
4941 	}
4942 
4943 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4944 		  journal_inode, journal_inode->i_size);
4945 	if (!S_ISREG(journal_inode->i_mode)) {
4946 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4947 		iput(journal_inode);
4948 		return NULL;
4949 	}
4950 	return journal_inode;
4951 }
4952 
4953 static journal_t *ext4_get_journal(struct super_block *sb,
4954 				   unsigned int journal_inum)
4955 {
4956 	struct inode *journal_inode;
4957 	journal_t *journal;
4958 
4959 	BUG_ON(!ext4_has_feature_journal(sb));
4960 
4961 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4962 	if (!journal_inode)
4963 		return NULL;
4964 
4965 	journal = jbd2_journal_init_inode(journal_inode);
4966 	if (!journal) {
4967 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4968 		iput(journal_inode);
4969 		return NULL;
4970 	}
4971 	journal->j_private = sb;
4972 	ext4_init_journal_params(sb, journal);
4973 	return journal;
4974 }
4975 
4976 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4977 				       dev_t j_dev)
4978 {
4979 	struct buffer_head *bh;
4980 	journal_t *journal;
4981 	ext4_fsblk_t start;
4982 	ext4_fsblk_t len;
4983 	int hblock, blocksize;
4984 	ext4_fsblk_t sb_block;
4985 	unsigned long offset;
4986 	struct ext4_super_block *es;
4987 	struct block_device *bdev;
4988 
4989 	BUG_ON(!ext4_has_feature_journal(sb));
4990 
4991 	bdev = ext4_blkdev_get(j_dev, sb);
4992 	if (bdev == NULL)
4993 		return NULL;
4994 
4995 	blocksize = sb->s_blocksize;
4996 	hblock = bdev_logical_block_size(bdev);
4997 	if (blocksize < hblock) {
4998 		ext4_msg(sb, KERN_ERR,
4999 			"blocksize too small for journal device");
5000 		goto out_bdev;
5001 	}
5002 
5003 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5004 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5005 	set_blocksize(bdev, blocksize);
5006 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5007 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5008 		       "external journal");
5009 		goto out_bdev;
5010 	}
5011 
5012 	es = (struct ext4_super_block *) (bh->b_data + offset);
5013 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5014 	    !(le32_to_cpu(es->s_feature_incompat) &
5015 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5016 		ext4_msg(sb, KERN_ERR, "external journal has "
5017 					"bad superblock");
5018 		brelse(bh);
5019 		goto out_bdev;
5020 	}
5021 
5022 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5023 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5024 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5025 		ext4_msg(sb, KERN_ERR, "external journal has "
5026 				       "corrupt superblock");
5027 		brelse(bh);
5028 		goto out_bdev;
5029 	}
5030 
5031 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5032 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5033 		brelse(bh);
5034 		goto out_bdev;
5035 	}
5036 
5037 	len = ext4_blocks_count(es);
5038 	start = sb_block + 1;
5039 	brelse(bh);	/* we're done with the superblock */
5040 
5041 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5042 					start, len, blocksize);
5043 	if (!journal) {
5044 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5045 		goto out_bdev;
5046 	}
5047 	journal->j_private = sb;
5048 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
5049 	wait_on_buffer(journal->j_sb_buffer);
5050 	if (!buffer_uptodate(journal->j_sb_buffer)) {
5051 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5052 		goto out_journal;
5053 	}
5054 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5055 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5056 					"user (unsupported) - %d",
5057 			be32_to_cpu(journal->j_superblock->s_nr_users));
5058 		goto out_journal;
5059 	}
5060 	EXT4_SB(sb)->journal_bdev = bdev;
5061 	ext4_init_journal_params(sb, journal);
5062 	return journal;
5063 
5064 out_journal:
5065 	jbd2_journal_destroy(journal);
5066 out_bdev:
5067 	ext4_blkdev_put(bdev);
5068 	return NULL;
5069 }
5070 
5071 static int ext4_load_journal(struct super_block *sb,
5072 			     struct ext4_super_block *es,
5073 			     unsigned long journal_devnum)
5074 {
5075 	journal_t *journal;
5076 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5077 	dev_t journal_dev;
5078 	int err = 0;
5079 	int really_read_only;
5080 
5081 	BUG_ON(!ext4_has_feature_journal(sb));
5082 
5083 	if (journal_devnum &&
5084 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5085 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5086 			"numbers have changed");
5087 		journal_dev = new_decode_dev(journal_devnum);
5088 	} else
5089 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5090 
5091 	really_read_only = bdev_read_only(sb->s_bdev);
5092 
5093 	/*
5094 	 * Are we loading a blank journal or performing recovery after a
5095 	 * crash?  For recovery, we need to check in advance whether we
5096 	 * can get read-write access to the device.
5097 	 */
5098 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5099 		if (sb_rdonly(sb)) {
5100 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5101 					"required on readonly filesystem");
5102 			if (really_read_only) {
5103 				ext4_msg(sb, KERN_ERR, "write access "
5104 					"unavailable, cannot proceed "
5105 					"(try mounting with noload)");
5106 				return -EROFS;
5107 			}
5108 			ext4_msg(sb, KERN_INFO, "write access will "
5109 			       "be enabled during recovery");
5110 		}
5111 	}
5112 
5113 	if (journal_inum && journal_dev) {
5114 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
5115 		       "and inode journals!");
5116 		return -EINVAL;
5117 	}
5118 
5119 	if (journal_inum) {
5120 		if (!(journal = ext4_get_journal(sb, journal_inum)))
5121 			return -EINVAL;
5122 	} else {
5123 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
5124 			return -EINVAL;
5125 	}
5126 
5127 	if (!(journal->j_flags & JBD2_BARRIER))
5128 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5129 
5130 	if (!ext4_has_feature_journal_needs_recovery(sb))
5131 		err = jbd2_journal_wipe(journal, !really_read_only);
5132 	if (!err) {
5133 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5134 		if (save)
5135 			memcpy(save, ((char *) es) +
5136 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5137 		err = jbd2_journal_load(journal);
5138 		if (save)
5139 			memcpy(((char *) es) + EXT4_S_ERR_START,
5140 			       save, EXT4_S_ERR_LEN);
5141 		kfree(save);
5142 	}
5143 
5144 	if (err) {
5145 		ext4_msg(sb, KERN_ERR, "error loading journal");
5146 		jbd2_journal_destroy(journal);
5147 		return err;
5148 	}
5149 
5150 	EXT4_SB(sb)->s_journal = journal;
5151 	ext4_clear_journal_err(sb, es);
5152 
5153 	if (!really_read_only && journal_devnum &&
5154 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5155 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5156 
5157 		/* Make sure we flush the recovery flag to disk. */
5158 		ext4_commit_super(sb, 1);
5159 	}
5160 
5161 	return 0;
5162 }
5163 
5164 static int ext4_commit_super(struct super_block *sb, int sync)
5165 {
5166 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
5167 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5168 	int error = 0;
5169 
5170 	if (!sbh || block_device_ejected(sb))
5171 		return error;
5172 
5173 	/*
5174 	 * The superblock bh should be mapped, but it might not be if the
5175 	 * device was hot-removed. Not much we can do but fail the I/O.
5176 	 */
5177 	if (!buffer_mapped(sbh))
5178 		return error;
5179 
5180 	/*
5181 	 * If the file system is mounted read-only, don't update the
5182 	 * superblock write time.  This avoids updating the superblock
5183 	 * write time when we are mounting the root file system
5184 	 * read/only but we need to replay the journal; at that point,
5185 	 * for people who are east of GMT and who make their clock
5186 	 * tick in localtime for Windows bug-for-bug compatibility,
5187 	 * the clock is set in the future, and this will cause e2fsck
5188 	 * to complain and force a full file system check.
5189 	 */
5190 	if (!(sb->s_flags & SB_RDONLY))
5191 		ext4_update_tstamp(es, s_wtime);
5192 	if (sb->s_bdev->bd_part)
5193 		es->s_kbytes_written =
5194 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5195 			    ((part_stat_read(sb->s_bdev->bd_part,
5196 					     sectors[STAT_WRITE]) -
5197 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
5198 	else
5199 		es->s_kbytes_written =
5200 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5201 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5202 		ext4_free_blocks_count_set(es,
5203 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5204 				&EXT4_SB(sb)->s_freeclusters_counter)));
5205 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5206 		es->s_free_inodes_count =
5207 			cpu_to_le32(percpu_counter_sum_positive(
5208 				&EXT4_SB(sb)->s_freeinodes_counter));
5209 	BUFFER_TRACE(sbh, "marking dirty");
5210 	ext4_superblock_csum_set(sb);
5211 	if (sync)
5212 		lock_buffer(sbh);
5213 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5214 		/*
5215 		 * Oh, dear.  A previous attempt to write the
5216 		 * superblock failed.  This could happen because the
5217 		 * USB device was yanked out.  Or it could happen to
5218 		 * be a transient write error and maybe the block will
5219 		 * be remapped.  Nothing we can do but to retry the
5220 		 * write and hope for the best.
5221 		 */
5222 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5223 		       "superblock detected");
5224 		clear_buffer_write_io_error(sbh);
5225 		set_buffer_uptodate(sbh);
5226 	}
5227 	mark_buffer_dirty(sbh);
5228 	if (sync) {
5229 		unlock_buffer(sbh);
5230 		error = __sync_dirty_buffer(sbh,
5231 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5232 		if (buffer_write_io_error(sbh)) {
5233 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5234 			       "superblock");
5235 			clear_buffer_write_io_error(sbh);
5236 			set_buffer_uptodate(sbh);
5237 		}
5238 	}
5239 	return error;
5240 }
5241 
5242 /*
5243  * Have we just finished recovery?  If so, and if we are mounting (or
5244  * remounting) the filesystem readonly, then we will end up with a
5245  * consistent fs on disk.  Record that fact.
5246  */
5247 static void ext4_mark_recovery_complete(struct super_block *sb,
5248 					struct ext4_super_block *es)
5249 {
5250 	journal_t *journal = EXT4_SB(sb)->s_journal;
5251 
5252 	if (!ext4_has_feature_journal(sb)) {
5253 		BUG_ON(journal != NULL);
5254 		return;
5255 	}
5256 	jbd2_journal_lock_updates(journal);
5257 	if (jbd2_journal_flush(journal) < 0)
5258 		goto out;
5259 
5260 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5261 		ext4_clear_feature_journal_needs_recovery(sb);
5262 		ext4_commit_super(sb, 1);
5263 	}
5264 
5265 out:
5266 	jbd2_journal_unlock_updates(journal);
5267 }
5268 
5269 /*
5270  * If we are mounting (or read-write remounting) a filesystem whose journal
5271  * has recorded an error from a previous lifetime, move that error to the
5272  * main filesystem now.
5273  */
5274 static void ext4_clear_journal_err(struct super_block *sb,
5275 				   struct ext4_super_block *es)
5276 {
5277 	journal_t *journal;
5278 	int j_errno;
5279 	const char *errstr;
5280 
5281 	BUG_ON(!ext4_has_feature_journal(sb));
5282 
5283 	journal = EXT4_SB(sb)->s_journal;
5284 
5285 	/*
5286 	 * Now check for any error status which may have been recorded in the
5287 	 * journal by a prior ext4_error() or ext4_abort()
5288 	 */
5289 
5290 	j_errno = jbd2_journal_errno(journal);
5291 	if (j_errno) {
5292 		char nbuf[16];
5293 
5294 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5295 		ext4_warning(sb, "Filesystem error recorded "
5296 			     "from previous mount: %s", errstr);
5297 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5298 
5299 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5300 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5301 		ext4_commit_super(sb, 1);
5302 
5303 		jbd2_journal_clear_err(journal);
5304 		jbd2_journal_update_sb_errno(journal);
5305 	}
5306 }
5307 
5308 /*
5309  * Force the running and committing transactions to commit,
5310  * and wait on the commit.
5311  */
5312 int ext4_force_commit(struct super_block *sb)
5313 {
5314 	journal_t *journal;
5315 
5316 	if (sb_rdonly(sb))
5317 		return 0;
5318 
5319 	journal = EXT4_SB(sb)->s_journal;
5320 	return ext4_journal_force_commit(journal);
5321 }
5322 
5323 static int ext4_sync_fs(struct super_block *sb, int wait)
5324 {
5325 	int ret = 0;
5326 	tid_t target;
5327 	bool needs_barrier = false;
5328 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5329 
5330 	if (unlikely(ext4_forced_shutdown(sbi)))
5331 		return 0;
5332 
5333 	trace_ext4_sync_fs(sb, wait);
5334 	flush_workqueue(sbi->rsv_conversion_wq);
5335 	/*
5336 	 * Writeback quota in non-journalled quota case - journalled quota has
5337 	 * no dirty dquots
5338 	 */
5339 	dquot_writeback_dquots(sb, -1);
5340 	/*
5341 	 * Data writeback is possible w/o journal transaction, so barrier must
5342 	 * being sent at the end of the function. But we can skip it if
5343 	 * transaction_commit will do it for us.
5344 	 */
5345 	if (sbi->s_journal) {
5346 		target = jbd2_get_latest_transaction(sbi->s_journal);
5347 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5348 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5349 			needs_barrier = true;
5350 
5351 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5352 			if (wait)
5353 				ret = jbd2_log_wait_commit(sbi->s_journal,
5354 							   target);
5355 		}
5356 	} else if (wait && test_opt(sb, BARRIER))
5357 		needs_barrier = true;
5358 	if (needs_barrier) {
5359 		int err;
5360 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL);
5361 		if (!ret)
5362 			ret = err;
5363 	}
5364 
5365 	return ret;
5366 }
5367 
5368 /*
5369  * LVM calls this function before a (read-only) snapshot is created.  This
5370  * gives us a chance to flush the journal completely and mark the fs clean.
5371  *
5372  * Note that only this function cannot bring a filesystem to be in a clean
5373  * state independently. It relies on upper layer to stop all data & metadata
5374  * modifications.
5375  */
5376 static int ext4_freeze(struct super_block *sb)
5377 {
5378 	int error = 0;
5379 	journal_t *journal;
5380 
5381 	if (sb_rdonly(sb))
5382 		return 0;
5383 
5384 	journal = EXT4_SB(sb)->s_journal;
5385 
5386 	if (journal) {
5387 		/* Now we set up the journal barrier. */
5388 		jbd2_journal_lock_updates(journal);
5389 
5390 		/*
5391 		 * Don't clear the needs_recovery flag if we failed to
5392 		 * flush the journal.
5393 		 */
5394 		error = jbd2_journal_flush(journal);
5395 		if (error < 0)
5396 			goto out;
5397 
5398 		/* Journal blocked and flushed, clear needs_recovery flag. */
5399 		ext4_clear_feature_journal_needs_recovery(sb);
5400 	}
5401 
5402 	error = ext4_commit_super(sb, 1);
5403 out:
5404 	if (journal)
5405 		/* we rely on upper layer to stop further updates */
5406 		jbd2_journal_unlock_updates(journal);
5407 	return error;
5408 }
5409 
5410 /*
5411  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5412  * flag here, even though the filesystem is not technically dirty yet.
5413  */
5414 static int ext4_unfreeze(struct super_block *sb)
5415 {
5416 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5417 		return 0;
5418 
5419 	if (EXT4_SB(sb)->s_journal) {
5420 		/* Reset the needs_recovery flag before the fs is unlocked. */
5421 		ext4_set_feature_journal_needs_recovery(sb);
5422 	}
5423 
5424 	ext4_commit_super(sb, 1);
5425 	return 0;
5426 }
5427 
5428 /*
5429  * Structure to save mount options for ext4_remount's benefit
5430  */
5431 struct ext4_mount_options {
5432 	unsigned long s_mount_opt;
5433 	unsigned long s_mount_opt2;
5434 	kuid_t s_resuid;
5435 	kgid_t s_resgid;
5436 	unsigned long s_commit_interval;
5437 	u32 s_min_batch_time, s_max_batch_time;
5438 #ifdef CONFIG_QUOTA
5439 	int s_jquota_fmt;
5440 	char *s_qf_names[EXT4_MAXQUOTAS];
5441 #endif
5442 };
5443 
5444 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5445 {
5446 	struct ext4_super_block *es;
5447 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5448 	unsigned long old_sb_flags;
5449 	struct ext4_mount_options old_opts;
5450 	int enable_quota = 0;
5451 	ext4_group_t g;
5452 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5453 	int err = 0;
5454 #ifdef CONFIG_QUOTA
5455 	int i, j;
5456 	char *to_free[EXT4_MAXQUOTAS];
5457 #endif
5458 	char *orig_data = kstrdup(data, GFP_KERNEL);
5459 
5460 	if (data && !orig_data)
5461 		return -ENOMEM;
5462 
5463 	/* Store the original options */
5464 	old_sb_flags = sb->s_flags;
5465 	old_opts.s_mount_opt = sbi->s_mount_opt;
5466 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5467 	old_opts.s_resuid = sbi->s_resuid;
5468 	old_opts.s_resgid = sbi->s_resgid;
5469 	old_opts.s_commit_interval = sbi->s_commit_interval;
5470 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5471 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5472 #ifdef CONFIG_QUOTA
5473 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5474 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5475 		if (sbi->s_qf_names[i]) {
5476 			char *qf_name = get_qf_name(sb, sbi, i);
5477 
5478 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5479 			if (!old_opts.s_qf_names[i]) {
5480 				for (j = 0; j < i; j++)
5481 					kfree(old_opts.s_qf_names[j]);
5482 				kfree(orig_data);
5483 				return -ENOMEM;
5484 			}
5485 		} else
5486 			old_opts.s_qf_names[i] = NULL;
5487 #endif
5488 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5489 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5490 
5491 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5492 		err = -EINVAL;
5493 		goto restore_opts;
5494 	}
5495 
5496 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5497 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5498 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5499 			 "during remount not supported; ignoring");
5500 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5501 	}
5502 
5503 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5504 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5505 			ext4_msg(sb, KERN_ERR, "can't mount with "
5506 				 "both data=journal and delalloc");
5507 			err = -EINVAL;
5508 			goto restore_opts;
5509 		}
5510 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5511 			ext4_msg(sb, KERN_ERR, "can't mount with "
5512 				 "both data=journal and dioread_nolock");
5513 			err = -EINVAL;
5514 			goto restore_opts;
5515 		}
5516 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5517 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5518 			ext4_msg(sb, KERN_ERR, "can't mount with "
5519 				"journal_async_commit in data=ordered mode");
5520 			err = -EINVAL;
5521 			goto restore_opts;
5522 		}
5523 	}
5524 
5525 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5526 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5527 		err = -EINVAL;
5528 		goto restore_opts;
5529 	}
5530 
5531 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5532 		ext4_abort(sb, EXT4_ERR_ESHUTDOWN, "Abort forced by user");
5533 
5534 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5535 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5536 
5537 	es = sbi->s_es;
5538 
5539 	if (sbi->s_journal) {
5540 		ext4_init_journal_params(sb, sbi->s_journal);
5541 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5542 	}
5543 
5544 	if (*flags & SB_LAZYTIME)
5545 		sb->s_flags |= SB_LAZYTIME;
5546 
5547 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5548 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5549 			err = -EROFS;
5550 			goto restore_opts;
5551 		}
5552 
5553 		if (*flags & SB_RDONLY) {
5554 			err = sync_filesystem(sb);
5555 			if (err < 0)
5556 				goto restore_opts;
5557 			err = dquot_suspend(sb, -1);
5558 			if (err < 0)
5559 				goto restore_opts;
5560 
5561 			/*
5562 			 * First of all, the unconditional stuff we have to do
5563 			 * to disable replay of the journal when we next remount
5564 			 */
5565 			sb->s_flags |= SB_RDONLY;
5566 
5567 			/*
5568 			 * OK, test if we are remounting a valid rw partition
5569 			 * readonly, and if so set the rdonly flag and then
5570 			 * mark the partition as valid again.
5571 			 */
5572 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5573 			    (sbi->s_mount_state & EXT4_VALID_FS))
5574 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5575 
5576 			if (sbi->s_journal)
5577 				ext4_mark_recovery_complete(sb, es);
5578 			if (sbi->s_mmp_tsk)
5579 				kthread_stop(sbi->s_mmp_tsk);
5580 		} else {
5581 			/* Make sure we can mount this feature set readwrite */
5582 			if (ext4_has_feature_readonly(sb) ||
5583 			    !ext4_feature_set_ok(sb, 0)) {
5584 				err = -EROFS;
5585 				goto restore_opts;
5586 			}
5587 			/*
5588 			 * Make sure the group descriptor checksums
5589 			 * are sane.  If they aren't, refuse to remount r/w.
5590 			 */
5591 			for (g = 0; g < sbi->s_groups_count; g++) {
5592 				struct ext4_group_desc *gdp =
5593 					ext4_get_group_desc(sb, g, NULL);
5594 
5595 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5596 					ext4_msg(sb, KERN_ERR,
5597 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5598 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5599 					       le16_to_cpu(gdp->bg_checksum));
5600 					err = -EFSBADCRC;
5601 					goto restore_opts;
5602 				}
5603 			}
5604 
5605 			/*
5606 			 * If we have an unprocessed orphan list hanging
5607 			 * around from a previously readonly bdev mount,
5608 			 * require a full umount/remount for now.
5609 			 */
5610 			if (es->s_last_orphan) {
5611 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5612 				       "remount RDWR because of unprocessed "
5613 				       "orphan inode list.  Please "
5614 				       "umount/remount instead");
5615 				err = -EINVAL;
5616 				goto restore_opts;
5617 			}
5618 
5619 			/*
5620 			 * Mounting a RDONLY partition read-write, so reread
5621 			 * and store the current valid flag.  (It may have
5622 			 * been changed by e2fsck since we originally mounted
5623 			 * the partition.)
5624 			 */
5625 			if (sbi->s_journal)
5626 				ext4_clear_journal_err(sb, es);
5627 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5628 
5629 			err = ext4_setup_super(sb, es, 0);
5630 			if (err)
5631 				goto restore_opts;
5632 
5633 			sb->s_flags &= ~SB_RDONLY;
5634 			if (ext4_has_feature_mmp(sb))
5635 				if (ext4_multi_mount_protect(sb,
5636 						le64_to_cpu(es->s_mmp_block))) {
5637 					err = -EROFS;
5638 					goto restore_opts;
5639 				}
5640 			enable_quota = 1;
5641 		}
5642 	}
5643 
5644 	/*
5645 	 * Reinitialize lazy itable initialization thread based on
5646 	 * current settings
5647 	 */
5648 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5649 		ext4_unregister_li_request(sb);
5650 	else {
5651 		ext4_group_t first_not_zeroed;
5652 		first_not_zeroed = ext4_has_uninit_itable(sb);
5653 		ext4_register_li_request(sb, first_not_zeroed);
5654 	}
5655 
5656 	ext4_setup_system_zone(sb);
5657 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5658 		err = ext4_commit_super(sb, 1);
5659 		if (err)
5660 			goto restore_opts;
5661 	}
5662 
5663 #ifdef CONFIG_QUOTA
5664 	/* Release old quota file names */
5665 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5666 		kfree(old_opts.s_qf_names[i]);
5667 	if (enable_quota) {
5668 		if (sb_any_quota_suspended(sb))
5669 			dquot_resume(sb, -1);
5670 		else if (ext4_has_feature_quota(sb)) {
5671 			err = ext4_enable_quotas(sb);
5672 			if (err)
5673 				goto restore_opts;
5674 		}
5675 	}
5676 #endif
5677 
5678 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5679 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5680 	kfree(orig_data);
5681 	return 0;
5682 
5683 restore_opts:
5684 	sb->s_flags = old_sb_flags;
5685 	sbi->s_mount_opt = old_opts.s_mount_opt;
5686 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5687 	sbi->s_resuid = old_opts.s_resuid;
5688 	sbi->s_resgid = old_opts.s_resgid;
5689 	sbi->s_commit_interval = old_opts.s_commit_interval;
5690 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5691 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5692 #ifdef CONFIG_QUOTA
5693 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5694 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5695 		to_free[i] = get_qf_name(sb, sbi, i);
5696 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5697 	}
5698 	synchronize_rcu();
5699 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5700 		kfree(to_free[i]);
5701 #endif
5702 	kfree(orig_data);
5703 	return err;
5704 }
5705 
5706 #ifdef CONFIG_QUOTA
5707 static int ext4_statfs_project(struct super_block *sb,
5708 			       kprojid_t projid, struct kstatfs *buf)
5709 {
5710 	struct kqid qid;
5711 	struct dquot *dquot;
5712 	u64 limit;
5713 	u64 curblock;
5714 
5715 	qid = make_kqid_projid(projid);
5716 	dquot = dqget(sb, qid);
5717 	if (IS_ERR(dquot))
5718 		return PTR_ERR(dquot);
5719 	spin_lock(&dquot->dq_dqb_lock);
5720 
5721 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
5722 			     dquot->dq_dqb.dqb_bhardlimit);
5723 	limit >>= sb->s_blocksize_bits;
5724 
5725 	if (limit && buf->f_blocks > limit) {
5726 		curblock = (dquot->dq_dqb.dqb_curspace +
5727 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5728 		buf->f_blocks = limit;
5729 		buf->f_bfree = buf->f_bavail =
5730 			(buf->f_blocks > curblock) ?
5731 			 (buf->f_blocks - curblock) : 0;
5732 	}
5733 
5734 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
5735 			     dquot->dq_dqb.dqb_ihardlimit);
5736 	if (limit && buf->f_files > limit) {
5737 		buf->f_files = limit;
5738 		buf->f_ffree =
5739 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5740 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5741 	}
5742 
5743 	spin_unlock(&dquot->dq_dqb_lock);
5744 	dqput(dquot);
5745 	return 0;
5746 }
5747 #endif
5748 
5749 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5750 {
5751 	struct super_block *sb = dentry->d_sb;
5752 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5753 	struct ext4_super_block *es = sbi->s_es;
5754 	ext4_fsblk_t overhead = 0, resv_blocks;
5755 	u64 fsid;
5756 	s64 bfree;
5757 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5758 
5759 	if (!test_opt(sb, MINIX_DF))
5760 		overhead = sbi->s_overhead;
5761 
5762 	buf->f_type = EXT4_SUPER_MAGIC;
5763 	buf->f_bsize = sb->s_blocksize;
5764 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5765 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5766 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5767 	/* prevent underflow in case that few free space is available */
5768 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5769 	buf->f_bavail = buf->f_bfree -
5770 			(ext4_r_blocks_count(es) + resv_blocks);
5771 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5772 		buf->f_bavail = 0;
5773 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5774 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5775 	buf->f_namelen = EXT4_NAME_LEN;
5776 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5777 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5778 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5779 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5780 
5781 #ifdef CONFIG_QUOTA
5782 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5783 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5784 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5785 #endif
5786 	return 0;
5787 }
5788 
5789 
5790 #ifdef CONFIG_QUOTA
5791 
5792 /*
5793  * Helper functions so that transaction is started before we acquire dqio_sem
5794  * to keep correct lock ordering of transaction > dqio_sem
5795  */
5796 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5797 {
5798 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5799 }
5800 
5801 static int ext4_write_dquot(struct dquot *dquot)
5802 {
5803 	int ret, err;
5804 	handle_t *handle;
5805 	struct inode *inode;
5806 
5807 	inode = dquot_to_inode(dquot);
5808 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5809 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5810 	if (IS_ERR(handle))
5811 		return PTR_ERR(handle);
5812 	ret = dquot_commit(dquot);
5813 	err = ext4_journal_stop(handle);
5814 	if (!ret)
5815 		ret = err;
5816 	return ret;
5817 }
5818 
5819 static int ext4_acquire_dquot(struct dquot *dquot)
5820 {
5821 	int ret, err;
5822 	handle_t *handle;
5823 
5824 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5825 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5826 	if (IS_ERR(handle))
5827 		return PTR_ERR(handle);
5828 	ret = dquot_acquire(dquot);
5829 	err = ext4_journal_stop(handle);
5830 	if (!ret)
5831 		ret = err;
5832 	return ret;
5833 }
5834 
5835 static int ext4_release_dquot(struct dquot *dquot)
5836 {
5837 	int ret, err;
5838 	handle_t *handle;
5839 
5840 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5841 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5842 	if (IS_ERR(handle)) {
5843 		/* Release dquot anyway to avoid endless cycle in dqput() */
5844 		dquot_release(dquot);
5845 		return PTR_ERR(handle);
5846 	}
5847 	ret = dquot_release(dquot);
5848 	err = ext4_journal_stop(handle);
5849 	if (!ret)
5850 		ret = err;
5851 	return ret;
5852 }
5853 
5854 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5855 {
5856 	struct super_block *sb = dquot->dq_sb;
5857 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5858 
5859 	/* Are we journaling quotas? */
5860 	if (ext4_has_feature_quota(sb) ||
5861 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5862 		dquot_mark_dquot_dirty(dquot);
5863 		return ext4_write_dquot(dquot);
5864 	} else {
5865 		return dquot_mark_dquot_dirty(dquot);
5866 	}
5867 }
5868 
5869 static int ext4_write_info(struct super_block *sb, int type)
5870 {
5871 	int ret, err;
5872 	handle_t *handle;
5873 
5874 	/* Data block + inode block */
5875 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5876 	if (IS_ERR(handle))
5877 		return PTR_ERR(handle);
5878 	ret = dquot_commit_info(sb, type);
5879 	err = ext4_journal_stop(handle);
5880 	if (!ret)
5881 		ret = err;
5882 	return ret;
5883 }
5884 
5885 /*
5886  * Turn on quotas during mount time - we need to find
5887  * the quota file and such...
5888  */
5889 static int ext4_quota_on_mount(struct super_block *sb, int type)
5890 {
5891 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5892 					EXT4_SB(sb)->s_jquota_fmt, type);
5893 }
5894 
5895 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5896 {
5897 	struct ext4_inode_info *ei = EXT4_I(inode);
5898 
5899 	/* The first argument of lockdep_set_subclass has to be
5900 	 * *exactly* the same as the argument to init_rwsem() --- in
5901 	 * this case, in init_once() --- or lockdep gets unhappy
5902 	 * because the name of the lock is set using the
5903 	 * stringification of the argument to init_rwsem().
5904 	 */
5905 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5906 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5907 }
5908 
5909 /*
5910  * Standard function to be called on quota_on
5911  */
5912 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5913 			 const struct path *path)
5914 {
5915 	int err;
5916 
5917 	if (!test_opt(sb, QUOTA))
5918 		return -EINVAL;
5919 
5920 	/* Quotafile not on the same filesystem? */
5921 	if (path->dentry->d_sb != sb)
5922 		return -EXDEV;
5923 	/* Journaling quota? */
5924 	if (EXT4_SB(sb)->s_qf_names[type]) {
5925 		/* Quotafile not in fs root? */
5926 		if (path->dentry->d_parent != sb->s_root)
5927 			ext4_msg(sb, KERN_WARNING,
5928 				"Quota file not on filesystem root. "
5929 				"Journaled quota will not work");
5930 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5931 	} else {
5932 		/*
5933 		 * Clear the flag just in case mount options changed since
5934 		 * last time.
5935 		 */
5936 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5937 	}
5938 
5939 	/*
5940 	 * When we journal data on quota file, we have to flush journal to see
5941 	 * all updates to the file when we bypass pagecache...
5942 	 */
5943 	if (EXT4_SB(sb)->s_journal &&
5944 	    ext4_should_journal_data(d_inode(path->dentry))) {
5945 		/*
5946 		 * We don't need to lock updates but journal_flush() could
5947 		 * otherwise be livelocked...
5948 		 */
5949 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5950 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5951 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5952 		if (err)
5953 			return err;
5954 	}
5955 
5956 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5957 	err = dquot_quota_on(sb, type, format_id, path);
5958 	if (err) {
5959 		lockdep_set_quota_inode(path->dentry->d_inode,
5960 					     I_DATA_SEM_NORMAL);
5961 	} else {
5962 		struct inode *inode = d_inode(path->dentry);
5963 		handle_t *handle;
5964 
5965 		/*
5966 		 * Set inode flags to prevent userspace from messing with quota
5967 		 * files. If this fails, we return success anyway since quotas
5968 		 * are already enabled and this is not a hard failure.
5969 		 */
5970 		inode_lock(inode);
5971 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5972 		if (IS_ERR(handle))
5973 			goto unlock_inode;
5974 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5975 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5976 				S_NOATIME | S_IMMUTABLE);
5977 		err = ext4_mark_inode_dirty(handle, inode);
5978 		ext4_journal_stop(handle);
5979 	unlock_inode:
5980 		inode_unlock(inode);
5981 	}
5982 	return err;
5983 }
5984 
5985 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5986 			     unsigned int flags)
5987 {
5988 	int err;
5989 	struct inode *qf_inode;
5990 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5991 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5992 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5993 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5994 	};
5995 
5996 	BUG_ON(!ext4_has_feature_quota(sb));
5997 
5998 	if (!qf_inums[type])
5999 		return -EPERM;
6000 
6001 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6002 	if (IS_ERR(qf_inode)) {
6003 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6004 		return PTR_ERR(qf_inode);
6005 	}
6006 
6007 	/* Don't account quota for quota files to avoid recursion */
6008 	qf_inode->i_flags |= S_NOQUOTA;
6009 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6010 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6011 	if (err)
6012 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6013 	iput(qf_inode);
6014 
6015 	return err;
6016 }
6017 
6018 /* Enable usage tracking for all quota types. */
6019 static int ext4_enable_quotas(struct super_block *sb)
6020 {
6021 	int type, err = 0;
6022 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6023 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6024 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6025 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6026 	};
6027 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6028 		test_opt(sb, USRQUOTA),
6029 		test_opt(sb, GRPQUOTA),
6030 		test_opt(sb, PRJQUOTA),
6031 	};
6032 
6033 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6034 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6035 		if (qf_inums[type]) {
6036 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6037 				DQUOT_USAGE_ENABLED |
6038 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6039 			if (err) {
6040 				ext4_warning(sb,
6041 					"Failed to enable quota tracking "
6042 					"(type=%d, err=%d). Please run "
6043 					"e2fsck to fix.", type, err);
6044 				for (type--; type >= 0; type--)
6045 					dquot_quota_off(sb, type);
6046 
6047 				return err;
6048 			}
6049 		}
6050 	}
6051 	return 0;
6052 }
6053 
6054 static int ext4_quota_off(struct super_block *sb, int type)
6055 {
6056 	struct inode *inode = sb_dqopt(sb)->files[type];
6057 	handle_t *handle;
6058 	int err;
6059 
6060 	/* Force all delayed allocation blocks to be allocated.
6061 	 * Caller already holds s_umount sem */
6062 	if (test_opt(sb, DELALLOC))
6063 		sync_filesystem(sb);
6064 
6065 	if (!inode || !igrab(inode))
6066 		goto out;
6067 
6068 	err = dquot_quota_off(sb, type);
6069 	if (err || ext4_has_feature_quota(sb))
6070 		goto out_put;
6071 
6072 	inode_lock(inode);
6073 	/*
6074 	 * Update modification times of quota files when userspace can
6075 	 * start looking at them. If we fail, we return success anyway since
6076 	 * this is not a hard failure and quotas are already disabled.
6077 	 */
6078 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6079 	if (IS_ERR(handle)) {
6080 		err = PTR_ERR(handle);
6081 		goto out_unlock;
6082 	}
6083 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6084 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6085 	inode->i_mtime = inode->i_ctime = current_time(inode);
6086 	err = ext4_mark_inode_dirty(handle, inode);
6087 	ext4_journal_stop(handle);
6088 out_unlock:
6089 	inode_unlock(inode);
6090 out_put:
6091 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6092 	iput(inode);
6093 	return err;
6094 out:
6095 	return dquot_quota_off(sb, type);
6096 }
6097 
6098 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6099  * acquiring the locks... As quota files are never truncated and quota code
6100  * itself serializes the operations (and no one else should touch the files)
6101  * we don't have to be afraid of races */
6102 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6103 			       size_t len, loff_t off)
6104 {
6105 	struct inode *inode = sb_dqopt(sb)->files[type];
6106 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6107 	int offset = off & (sb->s_blocksize - 1);
6108 	int tocopy;
6109 	size_t toread;
6110 	struct buffer_head *bh;
6111 	loff_t i_size = i_size_read(inode);
6112 
6113 	if (off > i_size)
6114 		return 0;
6115 	if (off+len > i_size)
6116 		len = i_size-off;
6117 	toread = len;
6118 	while (toread > 0) {
6119 		tocopy = sb->s_blocksize - offset < toread ?
6120 				sb->s_blocksize - offset : toread;
6121 		bh = ext4_bread(NULL, inode, blk, 0);
6122 		if (IS_ERR(bh))
6123 			return PTR_ERR(bh);
6124 		if (!bh)	/* A hole? */
6125 			memset(data, 0, tocopy);
6126 		else
6127 			memcpy(data, bh->b_data+offset, tocopy);
6128 		brelse(bh);
6129 		offset = 0;
6130 		toread -= tocopy;
6131 		data += tocopy;
6132 		blk++;
6133 	}
6134 	return len;
6135 }
6136 
6137 /* Write to quotafile (we know the transaction is already started and has
6138  * enough credits) */
6139 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6140 				const char *data, size_t len, loff_t off)
6141 {
6142 	struct inode *inode = sb_dqopt(sb)->files[type];
6143 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6144 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6145 	int retries = 0;
6146 	struct buffer_head *bh;
6147 	handle_t *handle = journal_current_handle();
6148 
6149 	if (EXT4_SB(sb)->s_journal && !handle) {
6150 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6151 			" cancelled because transaction is not started",
6152 			(unsigned long long)off, (unsigned long long)len);
6153 		return -EIO;
6154 	}
6155 	/*
6156 	 * Since we account only one data block in transaction credits,
6157 	 * then it is impossible to cross a block boundary.
6158 	 */
6159 	if (sb->s_blocksize - offset < len) {
6160 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6161 			" cancelled because not block aligned",
6162 			(unsigned long long)off, (unsigned long long)len);
6163 		return -EIO;
6164 	}
6165 
6166 	do {
6167 		bh = ext4_bread(handle, inode, blk,
6168 				EXT4_GET_BLOCKS_CREATE |
6169 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6170 	} while (PTR_ERR(bh) == -ENOSPC &&
6171 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6172 	if (IS_ERR(bh))
6173 		return PTR_ERR(bh);
6174 	if (!bh)
6175 		goto out;
6176 	BUFFER_TRACE(bh, "get write access");
6177 	err = ext4_journal_get_write_access(handle, bh);
6178 	if (err) {
6179 		brelse(bh);
6180 		return err;
6181 	}
6182 	lock_buffer(bh);
6183 	memcpy(bh->b_data+offset, data, len);
6184 	flush_dcache_page(bh->b_page);
6185 	unlock_buffer(bh);
6186 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6187 	brelse(bh);
6188 out:
6189 	if (inode->i_size < off + len) {
6190 		i_size_write(inode, off + len);
6191 		EXT4_I(inode)->i_disksize = inode->i_size;
6192 		err2 = ext4_mark_inode_dirty(handle, inode);
6193 		if (unlikely(err2 && !err))
6194 			err = err2;
6195 	}
6196 	return err ? err : len;
6197 }
6198 #endif
6199 
6200 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6201 		       const char *dev_name, void *data)
6202 {
6203 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6204 }
6205 
6206 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6207 static inline void register_as_ext2(void)
6208 {
6209 	int err = register_filesystem(&ext2_fs_type);
6210 	if (err)
6211 		printk(KERN_WARNING
6212 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6213 }
6214 
6215 static inline void unregister_as_ext2(void)
6216 {
6217 	unregister_filesystem(&ext2_fs_type);
6218 }
6219 
6220 static inline int ext2_feature_set_ok(struct super_block *sb)
6221 {
6222 	if (ext4_has_unknown_ext2_incompat_features(sb))
6223 		return 0;
6224 	if (sb_rdonly(sb))
6225 		return 1;
6226 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6227 		return 0;
6228 	return 1;
6229 }
6230 #else
6231 static inline void register_as_ext2(void) { }
6232 static inline void unregister_as_ext2(void) { }
6233 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6234 #endif
6235 
6236 static inline void register_as_ext3(void)
6237 {
6238 	int err = register_filesystem(&ext3_fs_type);
6239 	if (err)
6240 		printk(KERN_WARNING
6241 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6242 }
6243 
6244 static inline void unregister_as_ext3(void)
6245 {
6246 	unregister_filesystem(&ext3_fs_type);
6247 }
6248 
6249 static inline int ext3_feature_set_ok(struct super_block *sb)
6250 {
6251 	if (ext4_has_unknown_ext3_incompat_features(sb))
6252 		return 0;
6253 	if (!ext4_has_feature_journal(sb))
6254 		return 0;
6255 	if (sb_rdonly(sb))
6256 		return 1;
6257 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6258 		return 0;
6259 	return 1;
6260 }
6261 
6262 static struct file_system_type ext4_fs_type = {
6263 	.owner		= THIS_MODULE,
6264 	.name		= "ext4",
6265 	.mount		= ext4_mount,
6266 	.kill_sb	= kill_block_super,
6267 	.fs_flags	= FS_REQUIRES_DEV,
6268 };
6269 MODULE_ALIAS_FS("ext4");
6270 
6271 /* Shared across all ext4 file systems */
6272 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6273 
6274 static int __init ext4_init_fs(void)
6275 {
6276 	int i, err;
6277 
6278 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6279 	ext4_li_info = NULL;
6280 	mutex_init(&ext4_li_mtx);
6281 
6282 	/* Build-time check for flags consistency */
6283 	ext4_check_flag_values();
6284 
6285 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6286 		init_waitqueue_head(&ext4__ioend_wq[i]);
6287 
6288 	err = ext4_init_es();
6289 	if (err)
6290 		return err;
6291 
6292 	err = ext4_init_pending();
6293 	if (err)
6294 		goto out7;
6295 
6296 	err = ext4_init_post_read_processing();
6297 	if (err)
6298 		goto out6;
6299 
6300 	err = ext4_init_pageio();
6301 	if (err)
6302 		goto out5;
6303 
6304 	err = ext4_init_system_zone();
6305 	if (err)
6306 		goto out4;
6307 
6308 	err = ext4_init_sysfs();
6309 	if (err)
6310 		goto out3;
6311 
6312 	err = ext4_init_mballoc();
6313 	if (err)
6314 		goto out2;
6315 	err = init_inodecache();
6316 	if (err)
6317 		goto out1;
6318 	register_as_ext3();
6319 	register_as_ext2();
6320 	err = register_filesystem(&ext4_fs_type);
6321 	if (err)
6322 		goto out;
6323 
6324 	return 0;
6325 out:
6326 	unregister_as_ext2();
6327 	unregister_as_ext3();
6328 	destroy_inodecache();
6329 out1:
6330 	ext4_exit_mballoc();
6331 out2:
6332 	ext4_exit_sysfs();
6333 out3:
6334 	ext4_exit_system_zone();
6335 out4:
6336 	ext4_exit_pageio();
6337 out5:
6338 	ext4_exit_post_read_processing();
6339 out6:
6340 	ext4_exit_pending();
6341 out7:
6342 	ext4_exit_es();
6343 
6344 	return err;
6345 }
6346 
6347 static void __exit ext4_exit_fs(void)
6348 {
6349 	ext4_destroy_lazyinit_thread();
6350 	unregister_as_ext2();
6351 	unregister_as_ext3();
6352 	unregister_filesystem(&ext4_fs_type);
6353 	destroy_inodecache();
6354 	ext4_exit_mballoc();
6355 	ext4_exit_sysfs();
6356 	ext4_exit_system_zone();
6357 	ext4_exit_pageio();
6358 	ext4_exit_post_read_processing();
6359 	ext4_exit_es();
6360 	ext4_exit_pending();
6361 }
6362 
6363 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6364 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6365 MODULE_LICENSE("GPL");
6366 MODULE_SOFTDEP("pre: crc32c");
6367 module_init(ext4_init_fs)
6368 module_exit(ext4_exit_fs)
6369