xref: /openbmc/linux/fs/ext4/ext4.h (revision 7e170922)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  ext4.h
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/include/linux/minix_fs.h
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  */
16 
17 #ifndef _EXT4_H
18 #define _EXT4_H
19 
20 #include <linux/refcount.h>
21 #include <linux/types.h>
22 #include <linux/blkdev.h>
23 #include <linux/magic.h>
24 #include <linux/jbd2.h>
25 #include <linux/quota.h>
26 #include <linux/rwsem.h>
27 #include <linux/rbtree.h>
28 #include <linux/seqlock.h>
29 #include <linux/mutex.h>
30 #include <linux/timer.h>
31 #include <linux/wait.h>
32 #include <linux/sched/signal.h>
33 #include <linux/blockgroup_lock.h>
34 #include <linux/percpu_counter.h>
35 #include <linux/ratelimit.h>
36 #include <crypto/hash.h>
37 #include <linux/falloc.h>
38 #include <linux/percpu-rwsem.h>
39 #include <linux/fiemap.h>
40 #ifdef __KERNEL__
41 #include <linux/compat.h>
42 #endif
43 #include <uapi/linux/ext4.h>
44 
45 #include <linux/fscrypt.h>
46 #include <linux/fsverity.h>
47 
48 #include <linux/compiler.h>
49 
50 /*
51  * The fourth extended filesystem constants/structures
52  */
53 
54 /*
55  * with AGGRESSIVE_CHECK allocator runs consistency checks over
56  * structures. these checks slow things down a lot
57  */
58 #define AGGRESSIVE_CHECK__
59 
60 /*
61  * with DOUBLE_CHECK defined mballoc creates persistent in-core
62  * bitmaps, maintains and uses them to check for double allocations
63  */
64 #define DOUBLE_CHECK__
65 
66 /*
67  * Define EXT4FS_DEBUG to produce debug messages
68  */
69 #undef EXT4FS_DEBUG
70 
71 /*
72  * Debug code
73  */
74 #ifdef EXT4FS_DEBUG
75 #define ext4_debug(f, a...)						\
76 	do {								\
77 		printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",	\
78 			__FILE__, __LINE__, __func__);			\
79 		printk(KERN_DEBUG f, ## a);				\
80 	} while (0)
81 #else
82 #define ext4_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
83 #endif
84 
85  /*
86   * Turn on EXT_DEBUG to enable ext4_ext_show_path/leaf/move in extents.c
87   */
88 #define EXT_DEBUG__
89 
90 /*
91  * Dynamic printk for controlled extents debugging.
92  */
93 #ifdef CONFIG_EXT4_DEBUG
94 #define ext_debug(ino, fmt, ...)					\
95 	pr_debug("[%s/%d] EXT4-fs (%s): ino %lu: (%s, %d): %s:" fmt,	\
96 		 current->comm, task_pid_nr(current),			\
97 		 ino->i_sb->s_id, ino->i_ino, __FILE__, __LINE__,	\
98 		 __func__, ##__VA_ARGS__)
99 #else
100 #define ext_debug(ino, fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
101 #endif
102 
103 #define ASSERT(assert)						\
104 do {									\
105 	if (unlikely(!(assert))) {					\
106 		printk(KERN_EMERG					\
107 		       "Assertion failure in %s() at %s:%d: '%s'\n",	\
108 		       __func__, __FILE__, __LINE__, #assert);		\
109 		BUG();							\
110 	}								\
111 } while (0)
112 
113 /* data type for block offset of block group */
114 typedef int ext4_grpblk_t;
115 
116 /* data type for filesystem-wide blocks number */
117 typedef unsigned long long ext4_fsblk_t;
118 
119 /* data type for file logical block number */
120 typedef __u32 ext4_lblk_t;
121 
122 /* data type for block group number */
123 typedef unsigned int ext4_group_t;
124 
125 enum SHIFT_DIRECTION {
126 	SHIFT_LEFT = 0,
127 	SHIFT_RIGHT,
128 };
129 
130 /*
131  * Number of criterias defined. For each criteria, mballoc has slightly
132  * different way of finding the required blocks nad usually, higher the
133  * criteria the slower the allocation. We start at lower criterias and keep
134  * falling back to higher ones if we are not able to find any blocks.
135  */
136 #define EXT4_MB_NUM_CRS 5
137 /*
138  * All possible allocation criterias for mballoc
139  */
140 enum criteria {
141 	CR0,
142 	CR1,
143 	CR1_5,
144 	CR2,
145 	CR3,
146 };
147 
148 /*
149  * Flags used in mballoc's allocation_context flags field.
150  *
151  * Also used to show what's going on for debugging purposes when the
152  * flag field is exported via the traceport interface
153  */
154 
155 /* prefer goal again. length */
156 #define EXT4_MB_HINT_MERGE		0x0001
157 /* blocks already reserved */
158 #define EXT4_MB_HINT_RESERVED		0x0002
159 /* metadata is being allocated */
160 #define EXT4_MB_HINT_METADATA		0x0004
161 /* first blocks in the file */
162 #define EXT4_MB_HINT_FIRST		0x0008
163 /* search for the best chunk */
164 #define EXT4_MB_HINT_BEST		0x0010
165 /* data is being allocated */
166 #define EXT4_MB_HINT_DATA		0x0020
167 /* don't preallocate (for tails) */
168 #define EXT4_MB_HINT_NOPREALLOC		0x0040
169 /* allocate for locality group */
170 #define EXT4_MB_HINT_GROUP_ALLOC	0x0080
171 /* allocate goal blocks or none */
172 #define EXT4_MB_HINT_GOAL_ONLY		0x0100
173 /* goal is meaningful */
174 #define EXT4_MB_HINT_TRY_GOAL		0x0200
175 /* blocks already pre-reserved by delayed allocation */
176 #define EXT4_MB_DELALLOC_RESERVED	0x0400
177 /* We are doing stream allocation */
178 #define EXT4_MB_STREAM_ALLOC		0x0800
179 /* Use reserved root blocks if needed */
180 #define EXT4_MB_USE_ROOT_BLOCKS		0x1000
181 /* Use blocks from reserved pool */
182 #define EXT4_MB_USE_RESERVED		0x2000
183 /* Do strict check for free blocks while retrying block allocation */
184 #define EXT4_MB_STRICT_CHECK		0x4000
185 /* Large fragment size list lookup succeeded at least once for cr = 0 */
186 #define EXT4_MB_CR0_OPTIMIZED		0x8000
187 /* Avg fragment size rb tree lookup succeeded at least once for cr = 1 */
188 #define EXT4_MB_CR1_OPTIMIZED		0x00010000
189 /* Avg fragment size rb tree lookup succeeded at least once for cr = 1.5 */
190 #define EXT4_MB_CR1_5_OPTIMIZED		0x00020000
191 
192 struct ext4_allocation_request {
193 	/* target inode for block we're allocating */
194 	struct inode *inode;
195 	/* how many blocks we want to allocate */
196 	unsigned int len;
197 	/* logical block in target inode */
198 	ext4_lblk_t logical;
199 	/* the closest logical allocated block to the left */
200 	ext4_lblk_t lleft;
201 	/* the closest logical allocated block to the right */
202 	ext4_lblk_t lright;
203 	/* phys. target (a hint) */
204 	ext4_fsblk_t goal;
205 	/* phys. block for the closest logical allocated block to the left */
206 	ext4_fsblk_t pleft;
207 	/* phys. block for the closest logical allocated block to the right */
208 	ext4_fsblk_t pright;
209 	/* flags. see above EXT4_MB_HINT_* */
210 	unsigned int flags;
211 };
212 
213 /*
214  * Logical to physical block mapping, used by ext4_map_blocks()
215  *
216  * This structure is used to pass requests into ext4_map_blocks() as
217  * well as to store the information returned by ext4_map_blocks().  It
218  * takes less room on the stack than a struct buffer_head.
219  */
220 #define EXT4_MAP_NEW		BIT(BH_New)
221 #define EXT4_MAP_MAPPED		BIT(BH_Mapped)
222 #define EXT4_MAP_UNWRITTEN	BIT(BH_Unwritten)
223 #define EXT4_MAP_BOUNDARY	BIT(BH_Boundary)
224 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
225 				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY)
226 
227 struct ext4_map_blocks {
228 	ext4_fsblk_t m_pblk;
229 	ext4_lblk_t m_lblk;
230 	unsigned int m_len;
231 	unsigned int m_flags;
232 };
233 
234 /*
235  * Block validity checking, system zone rbtree.
236  */
237 struct ext4_system_blocks {
238 	struct rb_root root;
239 	struct rcu_head rcu;
240 };
241 
242 /*
243  * Flags for ext4_io_end->flags
244  */
245 #define	EXT4_IO_END_UNWRITTEN	0x0001
246 
247 struct ext4_io_end_vec {
248 	struct list_head list;		/* list of io_end_vec */
249 	loff_t offset;			/* offset in the file */
250 	ssize_t size;			/* size of the extent */
251 };
252 
253 /*
254  * For converting unwritten extents on a work queue. 'handle' is used for
255  * buffered writeback.
256  */
257 typedef struct ext4_io_end {
258 	struct list_head	list;		/* per-file finished IO list */
259 	handle_t		*handle;	/* handle reserved for extent
260 						 * conversion */
261 	struct inode		*inode;		/* file being written to */
262 	struct bio		*bio;		/* Linked list of completed
263 						 * bios covering the extent */
264 	unsigned int		flag;		/* unwritten or not */
265 	refcount_t		count;		/* reference counter */
266 	struct list_head	list_vec;	/* list of ext4_io_end_vec */
267 } ext4_io_end_t;
268 
269 struct ext4_io_submit {
270 	struct writeback_control *io_wbc;
271 	struct bio		*io_bio;
272 	ext4_io_end_t		*io_end;
273 	sector_t		io_next_block;
274 };
275 
276 /*
277  * Special inodes numbers
278  */
279 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
280 #define EXT4_ROOT_INO		 2	/* Root inode */
281 #define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
282 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
283 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
284 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
285 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
286 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
287 
288 /* First non-reserved inode for old ext4 filesystems */
289 #define EXT4_GOOD_OLD_FIRST_INO	11
290 
291 /*
292  * Maximal count of links to a file
293  */
294 #define EXT4_LINK_MAX		65000
295 
296 /*
297  * Macro-instructions used to manage several block sizes
298  */
299 #define EXT4_MIN_BLOCK_SIZE		1024
300 #define	EXT4_MAX_BLOCK_SIZE		65536
301 #define EXT4_MIN_BLOCK_LOG_SIZE		10
302 #define EXT4_MAX_BLOCK_LOG_SIZE		16
303 #define EXT4_MAX_CLUSTER_LOG_SIZE	30
304 #ifdef __KERNEL__
305 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
306 #else
307 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
308 #endif
309 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
310 #define EXT4_CLUSTER_SIZE(s)		(EXT4_BLOCK_SIZE(s) << \
311 					 EXT4_SB(s)->s_cluster_bits)
312 #ifdef __KERNEL__
313 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
314 # define EXT4_CLUSTER_BITS(s)		(EXT4_SB(s)->s_cluster_bits)
315 #else
316 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
317 #endif
318 #ifdef __KERNEL__
319 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
320 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
321 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
322 #else
323 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
324 				 EXT4_GOOD_OLD_INODE_SIZE : \
325 				 (s)->s_inode_size)
326 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
327 				 EXT4_GOOD_OLD_FIRST_INO : \
328 				 (s)->s_first_ino)
329 #endif
330 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
331 #define EXT4_MAX_BLOCKS(size, offset, blkbits) \
332 	((EXT4_BLOCK_ALIGN(size + offset, blkbits) >> blkbits) - (offset >> \
333 								  blkbits))
334 
335 /* Translate a block number to a cluster number */
336 #define EXT4_B2C(sbi, blk)	((blk) >> (sbi)->s_cluster_bits)
337 /* Translate a cluster number to a block number */
338 #define EXT4_C2B(sbi, cluster)	((cluster) << (sbi)->s_cluster_bits)
339 /* Translate # of blks to # of clusters */
340 #define EXT4_NUM_B2C(sbi, blks)	(((blks) + (sbi)->s_cluster_ratio - 1) >> \
341 				 (sbi)->s_cluster_bits)
342 /* Mask out the low bits to get the starting block of the cluster */
343 #define EXT4_PBLK_CMASK(s, pblk) ((pblk) &				\
344 				  ~((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
345 #define EXT4_LBLK_CMASK(s, lblk) ((lblk) &				\
346 				  ~((ext4_lblk_t) (s)->s_cluster_ratio - 1))
347 /* Fill in the low bits to get the last block of the cluster */
348 #define EXT4_LBLK_CFILL(sbi, lblk) ((lblk) |				\
349 				    ((ext4_lblk_t) (sbi)->s_cluster_ratio - 1))
350 /* Get the cluster offset */
351 #define EXT4_PBLK_COFF(s, pblk) ((pblk) &				\
352 				 ((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
353 #define EXT4_LBLK_COFF(s, lblk) ((lblk) &				\
354 				 ((ext4_lblk_t) (s)->s_cluster_ratio - 1))
355 
356 /*
357  * Structure of a blocks group descriptor
358  */
359 struct ext4_group_desc
360 {
361 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
362 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
363 	__le32	bg_inode_table_lo;	/* Inodes table block */
364 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
365 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
366 	__le16	bg_used_dirs_count_lo;	/* Directories count */
367 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
368 	__le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
369 	__le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
370 	__le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
371 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
372 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
373 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
374 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
375 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
376 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
377 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
378 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
379 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
380 	__le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
381 	__le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
382 	__le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
383 	__u32   bg_reserved;
384 };
385 
386 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END	\
387 	(offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
388 	 sizeof(__le16))
389 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END	\
390 	(offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
391 	 sizeof(__le16))
392 
393 /*
394  * Structure of a flex block group info
395  */
396 
397 struct flex_groups {
398 	atomic64_t	free_clusters;
399 	atomic_t	free_inodes;
400 	atomic_t	used_dirs;
401 };
402 
403 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
404 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
405 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
406 
407 /*
408  * Macro-instructions used to manage group descriptors
409  */
410 #define EXT4_MIN_DESC_SIZE		32
411 #define EXT4_MIN_DESC_SIZE_64BIT	64
412 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
413 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
414 #ifdef __KERNEL__
415 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
416 # define EXT4_CLUSTERS_PER_GROUP(s)	(EXT4_SB(s)->s_clusters_per_group)
417 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
418 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
419 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
420 #else
421 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
422 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
423 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
424 #endif
425 
426 /*
427  * Constants relative to the data blocks
428  */
429 #define	EXT4_NDIR_BLOCKS		12
430 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
431 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
432 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
433 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
434 
435 /*
436  * Inode flags
437  */
438 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
439 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
440 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
441 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
442 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
443 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
444 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
445 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
446 /* Reserved for compression usage... */
447 #define EXT4_DIRTY_FL			0x00000100
448 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
449 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
450 	/* nb: was previously EXT2_ECOMPR_FL */
451 #define EXT4_ENCRYPT_FL			0x00000800 /* encrypted file */
452 /* End compression flags --- maybe not all used */
453 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
454 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
455 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
456 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
457 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
458 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
459 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
460 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
461 #define EXT4_VERITY_FL			0x00100000 /* Verity protected inode */
462 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
463 /* 0x00400000 was formerly EXT4_EOFBLOCKS_FL */
464 
465 #define EXT4_DAX_FL			0x02000000 /* Inode is DAX */
466 
467 #define EXT4_INLINE_DATA_FL		0x10000000 /* Inode has inline data. */
468 #define EXT4_PROJINHERIT_FL		0x20000000 /* Create with parents projid */
469 #define EXT4_CASEFOLD_FL		0x40000000 /* Casefolded directory */
470 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
471 
472 /* User modifiable flags */
473 #define EXT4_FL_USER_MODIFIABLE		(EXT4_SECRM_FL | \
474 					 EXT4_UNRM_FL | \
475 					 EXT4_COMPR_FL | \
476 					 EXT4_SYNC_FL | \
477 					 EXT4_IMMUTABLE_FL | \
478 					 EXT4_APPEND_FL | \
479 					 EXT4_NODUMP_FL | \
480 					 EXT4_NOATIME_FL | \
481 					 EXT4_JOURNAL_DATA_FL | \
482 					 EXT4_NOTAIL_FL | \
483 					 EXT4_DIRSYNC_FL | \
484 					 EXT4_TOPDIR_FL | \
485 					 EXT4_EXTENTS_FL | \
486 					 0x00400000 /* EXT4_EOFBLOCKS_FL */ | \
487 					 EXT4_DAX_FL | \
488 					 EXT4_PROJINHERIT_FL | \
489 					 EXT4_CASEFOLD_FL)
490 
491 /* User visible flags */
492 #define EXT4_FL_USER_VISIBLE		(EXT4_FL_USER_MODIFIABLE | \
493 					 EXT4_DIRTY_FL | \
494 					 EXT4_COMPRBLK_FL | \
495 					 EXT4_NOCOMPR_FL | \
496 					 EXT4_ENCRYPT_FL | \
497 					 EXT4_INDEX_FL | \
498 					 EXT4_VERITY_FL | \
499 					 EXT4_INLINE_DATA_FL)
500 
501 /* Flags that should be inherited by new inodes from their parent. */
502 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
503 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
504 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
505 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL |\
506 			   EXT4_PROJINHERIT_FL | EXT4_CASEFOLD_FL |\
507 			   EXT4_DAX_FL)
508 
509 /* Flags that are appropriate for regular files (all but dir-specific ones). */
510 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL | EXT4_CASEFOLD_FL |\
511 			   EXT4_PROJINHERIT_FL))
512 
513 /* Flags that are appropriate for non-directories/regular files. */
514 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
515 
516 /* The only flags that should be swapped */
517 #define EXT4_FL_SHOULD_SWAP (EXT4_HUGE_FILE_FL | EXT4_EXTENTS_FL)
518 
519 /* Flags which are mutually exclusive to DAX */
520 #define EXT4_DAX_MUT_EXCL (EXT4_VERITY_FL | EXT4_ENCRYPT_FL |\
521 			   EXT4_JOURNAL_DATA_FL | EXT4_INLINE_DATA_FL)
522 
523 /* Mask out flags that are inappropriate for the given type of inode. */
524 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
525 {
526 	if (S_ISDIR(mode))
527 		return flags;
528 	else if (S_ISREG(mode))
529 		return flags & EXT4_REG_FLMASK;
530 	else
531 		return flags & EXT4_OTHER_FLMASK;
532 }
533 
534 /*
535  * Inode flags used for atomic set/get
536  */
537 enum {
538 	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
539 	EXT4_INODE_UNRM		= 1,	/* Undelete */
540 	EXT4_INODE_COMPR	= 2,	/* Compress file */
541 	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
542 	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
543 	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
544 	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
545 	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
546 /* Reserved for compression usage... */
547 	EXT4_INODE_DIRTY	= 8,
548 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
549 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
550 	EXT4_INODE_ENCRYPT	= 11,	/* Encrypted file */
551 /* End compression flags --- maybe not all used */
552 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
553 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
554 	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
555 	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
556 	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
557 	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
558 	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
559 	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
560 	EXT4_INODE_VERITY	= 20,	/* Verity protected inode */
561 	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
562 /* 22 was formerly EXT4_INODE_EOFBLOCKS */
563 	EXT4_INODE_DAX		= 25,	/* Inode is DAX */
564 	EXT4_INODE_INLINE_DATA	= 28,	/* Data in inode. */
565 	EXT4_INODE_PROJINHERIT	= 29,	/* Create with parents projid */
566 	EXT4_INODE_CASEFOLD	= 30,	/* Casefolded directory */
567 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
568 };
569 
570 /*
571  * Since it's pretty easy to mix up bit numbers and hex values, we use a
572  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
573  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
574  * any extra space in the compiled kernel image, otherwise, the build will fail.
575  * It's important that these values are the same, since we are using
576  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
577  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
578  * values found in ext2, ext3 and ext4 filesystems, and of course the values
579  * defined in e2fsprogs.
580  *
581  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
582  */
583 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1U << EXT4_INODE_##FLAG))
584 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
585 
586 static inline void ext4_check_flag_values(void)
587 {
588 	CHECK_FLAG_VALUE(SECRM);
589 	CHECK_FLAG_VALUE(UNRM);
590 	CHECK_FLAG_VALUE(COMPR);
591 	CHECK_FLAG_VALUE(SYNC);
592 	CHECK_FLAG_VALUE(IMMUTABLE);
593 	CHECK_FLAG_VALUE(APPEND);
594 	CHECK_FLAG_VALUE(NODUMP);
595 	CHECK_FLAG_VALUE(NOATIME);
596 	CHECK_FLAG_VALUE(DIRTY);
597 	CHECK_FLAG_VALUE(COMPRBLK);
598 	CHECK_FLAG_VALUE(NOCOMPR);
599 	CHECK_FLAG_VALUE(ENCRYPT);
600 	CHECK_FLAG_VALUE(INDEX);
601 	CHECK_FLAG_VALUE(IMAGIC);
602 	CHECK_FLAG_VALUE(JOURNAL_DATA);
603 	CHECK_FLAG_VALUE(NOTAIL);
604 	CHECK_FLAG_VALUE(DIRSYNC);
605 	CHECK_FLAG_VALUE(TOPDIR);
606 	CHECK_FLAG_VALUE(HUGE_FILE);
607 	CHECK_FLAG_VALUE(EXTENTS);
608 	CHECK_FLAG_VALUE(VERITY);
609 	CHECK_FLAG_VALUE(EA_INODE);
610 	CHECK_FLAG_VALUE(INLINE_DATA);
611 	CHECK_FLAG_VALUE(PROJINHERIT);
612 	CHECK_FLAG_VALUE(CASEFOLD);
613 	CHECK_FLAG_VALUE(RESERVED);
614 }
615 
616 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
617 struct compat_ext4_new_group_input {
618 	u32 group;
619 	compat_u64 block_bitmap;
620 	compat_u64 inode_bitmap;
621 	compat_u64 inode_table;
622 	u32 blocks_count;
623 	u16 reserved_blocks;
624 	u16 unused;
625 };
626 #endif
627 
628 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
629 struct ext4_new_group_data {
630 	__u32 group;
631 	__u64 block_bitmap;
632 	__u64 inode_bitmap;
633 	__u64 inode_table;
634 	__u32 blocks_count;
635 	__u16 reserved_blocks;
636 	__u16 mdata_blocks;
637 	__u32 free_clusters_count;
638 };
639 
640 /* Indexes used to index group tables in ext4_new_group_data */
641 enum {
642 	BLOCK_BITMAP = 0,	/* block bitmap */
643 	INODE_BITMAP,		/* inode bitmap */
644 	INODE_TABLE,		/* inode tables */
645 	GROUP_TABLE_COUNT,
646 };
647 
648 /*
649  * Flags used by ext4_map_blocks()
650  */
651 	/* Allocate any needed blocks and/or convert an unwritten
652 	   extent to be an initialized ext4 */
653 #define EXT4_GET_BLOCKS_CREATE			0x0001
654 	/* Request the creation of an unwritten extent */
655 #define EXT4_GET_BLOCKS_UNWRIT_EXT		0x0002
656 #define EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT	(EXT4_GET_BLOCKS_UNWRIT_EXT|\
657 						 EXT4_GET_BLOCKS_CREATE)
658 	/* Caller is from the delayed allocation writeout path
659 	 * finally doing the actual allocation of delayed blocks */
660 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
661 	/* caller is from the direct IO path, request to creation of an
662 	unwritten extents if not allocated, split the unwritten
663 	extent if blocks has been preallocated already*/
664 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
665 #define EXT4_GET_BLOCKS_CONVERT			0x0010
666 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
667 					 EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
668 	/* Convert extent to initialized after IO complete */
669 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
670 					 EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
671 	/* Eventual metadata allocation (due to growing extent tree)
672 	 * should not fail, so try to use reserved blocks for that.*/
673 #define EXT4_GET_BLOCKS_METADATA_NOFAIL		0x0020
674 	/* Don't normalize allocation size (used for fallocate) */
675 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
676 	/* Convert written extents to unwritten */
677 #define EXT4_GET_BLOCKS_CONVERT_UNWRITTEN	0x0100
678 	/* Write zeros to newly created written extents */
679 #define EXT4_GET_BLOCKS_ZERO			0x0200
680 #define EXT4_GET_BLOCKS_CREATE_ZERO		(EXT4_GET_BLOCKS_CREATE |\
681 					EXT4_GET_BLOCKS_ZERO)
682 	/* Caller will submit data before dropping transaction handle. This
683 	 * allows jbd2 to avoid submitting data before commit. */
684 #define EXT4_GET_BLOCKS_IO_SUBMIT		0x0400
685 	/* Caller is in the atomic contex, find extent if it has been cached */
686 #define EXT4_GET_BLOCKS_CACHED_NOWAIT		0x0800
687 
688 /*
689  * The bit position of these flags must not overlap with any of the
690  * EXT4_GET_BLOCKS_*.  They are used by ext4_find_extent(),
691  * read_extent_tree_block(), ext4_split_extent_at(),
692  * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf().
693  * EXT4_EX_NOCACHE is used to indicate that the we shouldn't be
694  * caching the extents when reading from the extent tree while a
695  * truncate or punch hole operation is in progress.
696  */
697 #define EXT4_EX_NOCACHE				0x40000000
698 #define EXT4_EX_FORCE_CACHE			0x20000000
699 #define EXT4_EX_NOFAIL				0x10000000
700 
701 /*
702  * Flags used by ext4_free_blocks
703  */
704 #define EXT4_FREE_BLOCKS_METADATA		0x0001
705 #define EXT4_FREE_BLOCKS_FORGET			0x0002
706 #define EXT4_FREE_BLOCKS_VALIDATED		0x0004
707 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE		0x0008
708 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
709 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
710 #define EXT4_FREE_BLOCKS_RERESERVE_CLUSTER      0x0040
711 
712 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
713 /*
714  * ioctl commands in 32 bit emulation
715  */
716 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
717 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
718 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
719 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
720 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
721 #define EXT4_IOC32_GROUP_ADD		_IOW('f', 8, struct compat_ext4_new_group_input)
722 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
723 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
724 #endif
725 
726 /* Max physical block we can address w/o extents */
727 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
728 
729 /* Max logical block we can support */
730 #define EXT4_MAX_LOGICAL_BLOCK		0xFFFFFFFE
731 
732 /*
733  * Structure of an inode on the disk
734  */
735 struct ext4_inode {
736 	__le16	i_mode;		/* File mode */
737 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
738 	__le32	i_size_lo;	/* Size in bytes */
739 	__le32	i_atime;	/* Access time */
740 	__le32	i_ctime;	/* Inode Change time */
741 	__le32	i_mtime;	/* Modification time */
742 	__le32	i_dtime;	/* Deletion Time */
743 	__le16	i_gid;		/* Low 16 bits of Group Id */
744 	__le16	i_links_count;	/* Links count */
745 	__le32	i_blocks_lo;	/* Blocks count */
746 	__le32	i_flags;	/* File flags */
747 	union {
748 		struct {
749 			__le32  l_i_version;
750 		} linux1;
751 		struct {
752 			__u32  h_i_translator;
753 		} hurd1;
754 		struct {
755 			__u32  m_i_reserved1;
756 		} masix1;
757 	} osd1;				/* OS dependent 1 */
758 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
759 	__le32	i_generation;	/* File version (for NFS) */
760 	__le32	i_file_acl_lo;	/* File ACL */
761 	__le32	i_size_high;
762 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
763 	union {
764 		struct {
765 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
766 			__le16	l_i_file_acl_high;
767 			__le16	l_i_uid_high;	/* these 2 fields */
768 			__le16	l_i_gid_high;	/* were reserved2[0] */
769 			__le16	l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
770 			__le16	l_i_reserved;
771 		} linux2;
772 		struct {
773 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
774 			__u16	h_i_mode_high;
775 			__u16	h_i_uid_high;
776 			__u16	h_i_gid_high;
777 			__u32	h_i_author;
778 		} hurd2;
779 		struct {
780 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
781 			__le16	m_i_file_acl_high;
782 			__u32	m_i_reserved2[2];
783 		} masix2;
784 	} osd2;				/* OS dependent 2 */
785 	__le16	i_extra_isize;
786 	__le16	i_checksum_hi;	/* crc32c(uuid+inum+inode) BE */
787 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
788 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
789 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
790 	__le32  i_crtime;       /* File Creation time */
791 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
792 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
793 	__le32	i_projid;	/* Project ID */
794 };
795 
796 #define EXT4_EPOCH_BITS 2
797 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
798 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
799 
800 /*
801  * Extended fields will fit into an inode if the filesystem was formatted
802  * with large inodes (-I 256 or larger) and there are not currently any EAs
803  * consuming all of the available space. For new inodes we always reserve
804  * enough space for the kernel's known extended fields, but for inodes
805  * created with an old kernel this might not have been the case. None of
806  * the extended inode fields is critical for correct filesystem operation.
807  * This macro checks if a certain field fits in the inode. Note that
808  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
809  */
810 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
811 	((offsetof(typeof(*ext4_inode), field) +	\
812 	  sizeof((ext4_inode)->field))			\
813 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
814 	    (einode)->i_extra_isize))			\
815 
816 /*
817  * We use an encoding that preserves the times for extra epoch "00":
818  *
819  * extra  msb of                         adjust for signed
820  * epoch  32-bit                         32-bit tv_sec to
821  * bits   time    decoded 64-bit tv_sec  64-bit tv_sec      valid time range
822  * 0 0    1    -0x80000000..-0x00000001  0x000000000 1901-12-13..1969-12-31
823  * 0 0    0    0x000000000..0x07fffffff  0x000000000 1970-01-01..2038-01-19
824  * 0 1    1    0x080000000..0x0ffffffff  0x100000000 2038-01-19..2106-02-07
825  * 0 1    0    0x100000000..0x17fffffff  0x100000000 2106-02-07..2174-02-25
826  * 1 0    1    0x180000000..0x1ffffffff  0x200000000 2174-02-25..2242-03-16
827  * 1 0    0    0x200000000..0x27fffffff  0x200000000 2242-03-16..2310-04-04
828  * 1 1    1    0x280000000..0x2ffffffff  0x300000000 2310-04-04..2378-04-22
829  * 1 1    0    0x300000000..0x37fffffff  0x300000000 2378-04-22..2446-05-10
830  *
831  * Note that previous versions of the kernel on 64-bit systems would
832  * incorrectly use extra epoch bits 1,1 for dates between 1901 and
833  * 1970.  e2fsck will correct this, assuming that it is run on the
834  * affected filesystem before 2242.
835  */
836 
837 static inline __le32 ext4_encode_extra_time(struct timespec64 *time)
838 {
839 	u32 extra =((time->tv_sec - (s32)time->tv_sec) >> 32) & EXT4_EPOCH_MASK;
840 	return cpu_to_le32(extra | (time->tv_nsec << EXT4_EPOCH_BITS));
841 }
842 
843 static inline void ext4_decode_extra_time(struct timespec64 *time,
844 					  __le32 extra)
845 {
846 	if (unlikely(extra & cpu_to_le32(EXT4_EPOCH_MASK)))
847 		time->tv_sec += (u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK) << 32;
848 	time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
849 }
850 
851 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)				\
852 do {										\
853 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     {\
854 		(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	\
855 		(raw_inode)->xtime ## _extra =					\
856 				ext4_encode_extra_time(&(inode)->xtime);	\
857 		}								\
858 	else	\
859 		(raw_inode)->xtime = cpu_to_le32(clamp_t(int32_t, (inode)->xtime.tv_sec, S32_MIN, S32_MAX));	\
860 } while (0)
861 
862 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
863 do {									       \
864 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
865 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
866 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
867 		(raw_inode)->xtime ## _extra =				       \
868 				ext4_encode_extra_time(&(einode)->xtime);      \
869 } while (0)
870 
871 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)				\
872 do {										\
873 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);	\
874 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra)) {	\
875 		ext4_decode_extra_time(&(inode)->xtime,				\
876 				       raw_inode->xtime ## _extra);		\
877 		}								\
878 	else									\
879 		(inode)->xtime.tv_nsec = 0;					\
880 } while (0)
881 
882 
883 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
884 do {									       \
885 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
886 		(einode)->xtime.tv_sec = 				       \
887 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
888 	else								       \
889 		(einode)->xtime.tv_sec = 0;				       \
890 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
891 		ext4_decode_extra_time(&(einode)->xtime,		       \
892 				       raw_inode->xtime ## _extra);	       \
893 	else								       \
894 		(einode)->xtime.tv_nsec = 0;				       \
895 } while (0)
896 
897 #define i_disk_version osd1.linux1.l_i_version
898 
899 #if defined(__KERNEL__) || defined(__linux__)
900 #define i_reserved1	osd1.linux1.l_i_reserved1
901 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
902 #define i_blocks_high	osd2.linux2.l_i_blocks_high
903 #define i_uid_low	i_uid
904 #define i_gid_low	i_gid
905 #define i_uid_high	osd2.linux2.l_i_uid_high
906 #define i_gid_high	osd2.linux2.l_i_gid_high
907 #define i_checksum_lo	osd2.linux2.l_i_checksum_lo
908 
909 #elif defined(__GNU__)
910 
911 #define i_translator	osd1.hurd1.h_i_translator
912 #define i_uid_high	osd2.hurd2.h_i_uid_high
913 #define i_gid_high	osd2.hurd2.h_i_gid_high
914 #define i_author	osd2.hurd2.h_i_author
915 
916 #elif defined(__masix__)
917 
918 #define i_reserved1	osd1.masix1.m_i_reserved1
919 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
920 #define i_reserved2	osd2.masix2.m_i_reserved2
921 
922 #endif /* defined(__KERNEL__) || defined(__linux__) */
923 
924 #include "extents_status.h"
925 #include "fast_commit.h"
926 
927 /*
928  * Lock subclasses for i_data_sem in the ext4_inode_info structure.
929  *
930  * These are needed to avoid lockdep false positives when we need to
931  * allocate blocks to the quota inode during ext4_map_blocks(), while
932  * holding i_data_sem for a normal (non-quota) inode.  Since we don't
933  * do quota tracking for the quota inode, this avoids deadlock (as
934  * well as infinite recursion, since it isn't turtles all the way
935  * down...)
936  *
937  *  I_DATA_SEM_NORMAL - Used for most inodes
938  *  I_DATA_SEM_OTHER  - Used by move_inode.c for the second normal inode
939  *			  where the second inode has larger inode number
940  *			  than the first
941  *  I_DATA_SEM_QUOTA  - Used for quota inodes only
942  *  I_DATA_SEM_EA     - Used for ea_inodes only
943  */
944 enum {
945 	I_DATA_SEM_NORMAL = 0,
946 	I_DATA_SEM_OTHER,
947 	I_DATA_SEM_QUOTA,
948 	I_DATA_SEM_EA
949 };
950 
951 
952 /*
953  * fourth extended file system inode data in memory
954  */
955 struct ext4_inode_info {
956 	__le32	i_data[15];	/* unconverted */
957 	__u32	i_dtime;
958 	ext4_fsblk_t	i_file_acl;
959 
960 	/*
961 	 * i_block_group is the number of the block group which contains
962 	 * this file's inode.  Constant across the lifetime of the inode,
963 	 * it is used for making block allocation decisions - we try to
964 	 * place a file's data blocks near its inode block, and new inodes
965 	 * near to their parent directory's inode.
966 	 */
967 	ext4_group_t	i_block_group;
968 	ext4_lblk_t	i_dir_start_lookup;
969 #if (BITS_PER_LONG < 64)
970 	unsigned long	i_state_flags;		/* Dynamic state flags */
971 #endif
972 	unsigned long	i_flags;
973 
974 	/*
975 	 * Extended attributes can be read independently of the main file
976 	 * data. Taking i_rwsem even when reading would cause contention
977 	 * between readers of EAs and writers of regular file data, so
978 	 * instead we synchronize on xattr_sem when reading or changing
979 	 * EAs.
980 	 */
981 	struct rw_semaphore xattr_sem;
982 
983 	/*
984 	 * Inodes with EXT4_STATE_ORPHAN_FILE use i_orphan_idx. Otherwise
985 	 * i_orphan is used.
986 	 */
987 	union {
988 		struct list_head i_orphan;	/* unlinked but open inodes */
989 		unsigned int i_orphan_idx;	/* Index in orphan file */
990 	};
991 
992 	/* Fast commit related info */
993 
994 	/* For tracking dentry create updates */
995 	struct list_head i_fc_dilist;
996 	struct list_head i_fc_list;	/*
997 					 * inodes that need fast commit
998 					 * protected by sbi->s_fc_lock.
999 					 */
1000 
1001 	/* Start of lblk range that needs to be committed in this fast commit */
1002 	ext4_lblk_t i_fc_lblk_start;
1003 
1004 	/* End of lblk range that needs to be committed in this fast commit */
1005 	ext4_lblk_t i_fc_lblk_len;
1006 
1007 	/* Number of ongoing updates on this inode */
1008 	atomic_t  i_fc_updates;
1009 
1010 	/* Fast commit wait queue for this inode */
1011 	wait_queue_head_t i_fc_wait;
1012 
1013 	/* Protect concurrent accesses on i_fc_lblk_start, i_fc_lblk_len */
1014 	struct mutex i_fc_lock;
1015 
1016 	/*
1017 	 * i_disksize keeps track of what the inode size is ON DISK, not
1018 	 * in memory.  During truncate, i_size is set to the new size by
1019 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
1020 	 * set i_disksize to 0 until the truncate is actually under way.
1021 	 *
1022 	 * The intent is that i_disksize always represents the blocks which
1023 	 * are used by this file.  This allows recovery to restart truncate
1024 	 * on orphans if we crash during truncate.  We actually write i_disksize
1025 	 * into the on-disk inode when writing inodes out, instead of i_size.
1026 	 *
1027 	 * The only time when i_disksize and i_size may be different is when
1028 	 * a truncate is in progress.  The only things which change i_disksize
1029 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
1030 	 */
1031 	loff_t	i_disksize;
1032 
1033 	/*
1034 	 * i_data_sem is for serialising ext4_truncate() against
1035 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
1036 	 * data tree are chopped off during truncate. We can't do that in
1037 	 * ext4 because whenever we perform intermediate commits during
1038 	 * truncate, the inode and all the metadata blocks *must* be in a
1039 	 * consistent state which allows truncation of the orphans to restart
1040 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
1041 	 * by other means, so we have i_data_sem.
1042 	 */
1043 	struct rw_semaphore i_data_sem;
1044 	struct inode vfs_inode;
1045 	struct jbd2_inode *jinode;
1046 
1047 	spinlock_t i_raw_lock;	/* protects updates to the raw inode */
1048 
1049 	/*
1050 	 * File creation time. Its function is same as that of
1051 	 * struct timespec64 i_{a,c,m}time in the generic inode.
1052 	 */
1053 	struct timespec64 i_crtime;
1054 
1055 	/* mballoc */
1056 	atomic_t i_prealloc_active;
1057 	struct rb_root i_prealloc_node;
1058 	rwlock_t i_prealloc_lock;
1059 
1060 	/* extents status tree */
1061 	struct ext4_es_tree i_es_tree;
1062 	rwlock_t i_es_lock;
1063 	struct list_head i_es_list;
1064 	unsigned int i_es_all_nr;	/* protected by i_es_lock */
1065 	unsigned int i_es_shk_nr;	/* protected by i_es_lock */
1066 	ext4_lblk_t i_es_shrink_lblk;	/* Offset where we start searching for
1067 					   extents to shrink. Protected by
1068 					   i_es_lock  */
1069 
1070 	/* ialloc */
1071 	ext4_group_t	i_last_alloc_group;
1072 
1073 	/* allocation reservation info for delalloc */
1074 	/* In case of bigalloc, this refer to clusters rather than blocks */
1075 	unsigned int i_reserved_data_blocks;
1076 
1077 	/* pending cluster reservations for bigalloc file systems */
1078 	struct ext4_pending_tree i_pending_tree;
1079 
1080 	/* on-disk additional length */
1081 	__u16 i_extra_isize;
1082 
1083 	/* Indicate the inline data space. */
1084 	u16 i_inline_off;
1085 	u16 i_inline_size;
1086 
1087 #ifdef CONFIG_QUOTA
1088 	/* quota space reservation, managed internally by quota code */
1089 	qsize_t i_reserved_quota;
1090 #endif
1091 
1092 	/* Lock protecting lists below */
1093 	spinlock_t i_completed_io_lock;
1094 	/*
1095 	 * Completed IOs that need unwritten extents handling and have
1096 	 * transaction reserved
1097 	 */
1098 	struct list_head i_rsv_conversion_list;
1099 	struct work_struct i_rsv_conversion_work;
1100 	atomic_t i_unwritten; /* Nr. of inflight conversions pending */
1101 
1102 	spinlock_t i_block_reservation_lock;
1103 
1104 	/*
1105 	 * Transactions that contain inode's metadata needed to complete
1106 	 * fsync and fdatasync, respectively.
1107 	 */
1108 	tid_t i_sync_tid;
1109 	tid_t i_datasync_tid;
1110 
1111 #ifdef CONFIG_QUOTA
1112 	struct dquot *i_dquot[MAXQUOTAS];
1113 #endif
1114 
1115 	/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
1116 	__u32 i_csum_seed;
1117 
1118 	kprojid_t i_projid;
1119 };
1120 
1121 /*
1122  * File system states
1123  */
1124 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
1125 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
1126 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
1127 #define EXT4_FC_REPLAY			0x0020	/* Fast commit replay ongoing */
1128 
1129 /*
1130  * Misc. filesystem flags
1131  */
1132 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
1133 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
1134 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
1135 
1136 /*
1137  * Mount flags set via mount options or defaults
1138  */
1139 #define EXT4_MOUNT_NO_MBCACHE		0x00001 /* Do not use mbcache */
1140 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
1141 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
1142 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
1143 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
1144 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
1145 #define EXT4_MOUNT_ERRORS_MASK		0x00070
1146 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
1147 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
1148 #ifdef CONFIG_FS_DAX
1149 #define EXT4_MOUNT_DAX_ALWAYS		0x00200	/* Direct Access */
1150 #else
1151 #define EXT4_MOUNT_DAX_ALWAYS		0
1152 #endif
1153 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
1154 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
1155 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
1156 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
1157 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
1158 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
1159 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
1160 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
1161 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
1162 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
1163 #define EXT4_MOUNT_QUOTA		0x40000 /* Some quota option set */
1164 #define EXT4_MOUNT_USRQUOTA		0x80000 /* "old" user quota,
1165 						 * enable enforcement for hidden
1166 						 * quota files */
1167 #define EXT4_MOUNT_GRPQUOTA		0x100000 /* "old" group quota, enable
1168 						  * enforcement for hidden quota
1169 						  * files */
1170 #define EXT4_MOUNT_PRJQUOTA		0x200000 /* Enable project quota
1171 						  * enforcement */
1172 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
1173 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
1174 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
1175 #define EXT4_MOUNT_WARN_ON_ERROR	0x2000000 /* Trigger WARN_ON on error */
1176 #define EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS 0x4000000
1177 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
1178 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
1179 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
1180 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
1181 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
1182 
1183 /*
1184  * Mount flags set either automatically (could not be set by mount option)
1185  * based on per file system feature or property or in special cases such as
1186  * distinguishing between explicit mount option definition and default.
1187  */
1188 #define EXT4_MOUNT2_EXPLICIT_DELALLOC	0x00000001 /* User explicitly
1189 						      specified delalloc */
1190 #define EXT4_MOUNT2_STD_GROUP_SIZE	0x00000002 /* We have standard group
1191 						      size of blocksize * 8
1192 						      blocks */
1193 #define EXT4_MOUNT2_HURD_COMPAT		0x00000004 /* Support HURD-castrated
1194 						      file systems */
1195 #define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM	0x00000008 /* User explicitly
1196 						specified journal checksum */
1197 
1198 #define EXT4_MOUNT2_JOURNAL_FAST_COMMIT	0x00000010 /* Journal fast commit */
1199 #define EXT4_MOUNT2_DAX_NEVER		0x00000020 /* Do not allow Direct Access */
1200 #define EXT4_MOUNT2_DAX_INODE		0x00000040 /* For printing options only */
1201 #define EXT4_MOUNT2_MB_OPTIMIZE_SCAN	0x00000080 /* Optimize group
1202 						    * scanning in mballoc
1203 						    */
1204 
1205 #define clear_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt &= \
1206 						~EXT4_MOUNT_##opt
1207 #define set_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt |= \
1208 						EXT4_MOUNT_##opt
1209 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
1210 					 EXT4_MOUNT_##opt)
1211 
1212 #define clear_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 &= \
1213 						~EXT4_MOUNT2_##opt
1214 #define set_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 |= \
1215 						EXT4_MOUNT2_##opt
1216 #define test_opt2(sb, opt)		(EXT4_SB(sb)->s_mount_opt2 & \
1217 					 EXT4_MOUNT2_##opt)
1218 
1219 #define ext4_test_and_set_bit		__test_and_set_bit_le
1220 #define ext4_set_bit			__set_bit_le
1221 #define ext4_set_bit_atomic		ext2_set_bit_atomic
1222 #define ext4_test_and_clear_bit		__test_and_clear_bit_le
1223 #define ext4_clear_bit			__clear_bit_le
1224 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
1225 #define ext4_test_bit			test_bit_le
1226 #define ext4_find_next_zero_bit		find_next_zero_bit_le
1227 #define ext4_find_next_bit		find_next_bit_le
1228 
1229 extern void mb_set_bits(void *bm, int cur, int len);
1230 
1231 /*
1232  * Maximal mount counts between two filesystem checks
1233  */
1234 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
1235 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
1236 
1237 /*
1238  * Behaviour when detecting errors
1239  */
1240 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
1241 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
1242 #define EXT4_ERRORS_PANIC		3	/* Panic */
1243 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
1244 
1245 /* Metadata checksum algorithm codes */
1246 #define EXT4_CRC32C_CHKSUM		1
1247 
1248 #define EXT4_LABEL_MAX			16
1249 
1250 /*
1251  * Structure of the super block
1252  */
1253 struct ext4_super_block {
1254 /*00*/	__le32	s_inodes_count;		/* Inodes count */
1255 	__le32	s_blocks_count_lo;	/* Blocks count */
1256 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
1257 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
1258 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
1259 	__le32	s_first_data_block;	/* First Data Block */
1260 	__le32	s_log_block_size;	/* Block size */
1261 	__le32	s_log_cluster_size;	/* Allocation cluster size */
1262 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
1263 	__le32	s_clusters_per_group;	/* # Clusters per group */
1264 	__le32	s_inodes_per_group;	/* # Inodes per group */
1265 	__le32	s_mtime;		/* Mount time */
1266 /*30*/	__le32	s_wtime;		/* Write time */
1267 	__le16	s_mnt_count;		/* Mount count */
1268 	__le16	s_max_mnt_count;	/* Maximal mount count */
1269 	__le16	s_magic;		/* Magic signature */
1270 	__le16	s_state;		/* File system state */
1271 	__le16	s_errors;		/* Behaviour when detecting errors */
1272 	__le16	s_minor_rev_level;	/* minor revision level */
1273 /*40*/	__le32	s_lastcheck;		/* time of last check */
1274 	__le32	s_checkinterval;	/* max. time between checks */
1275 	__le32	s_creator_os;		/* OS */
1276 	__le32	s_rev_level;		/* Revision level */
1277 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
1278 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
1279 	/*
1280 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
1281 	 *
1282 	 * Note: the difference between the compatible feature set and
1283 	 * the incompatible feature set is that if there is a bit set
1284 	 * in the incompatible feature set that the kernel doesn't
1285 	 * know about, it should refuse to mount the filesystem.
1286 	 *
1287 	 * e2fsck's requirements are more strict; if it doesn't know
1288 	 * about a feature in either the compatible or incompatible
1289 	 * feature set, it must abort and not try to meddle with
1290 	 * things it doesn't understand...
1291 	 */
1292 	__le32	s_first_ino;		/* First non-reserved inode */
1293 	__le16  s_inode_size;		/* size of inode structure */
1294 	__le16	s_block_group_nr;	/* block group # of this superblock */
1295 	__le32	s_feature_compat;	/* compatible feature set */
1296 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
1297 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
1298 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
1299 /*78*/	char	s_volume_name[EXT4_LABEL_MAX];	/* volume name */
1300 /*88*/	char	s_last_mounted[64] __nonstring;	/* directory where last mounted */
1301 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
1302 	/*
1303 	 * Performance hints.  Directory preallocation should only
1304 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1305 	 */
1306 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
1307 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
1308 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
1309 	/*
1310 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1311 	 */
1312 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
1313 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
1314 	__le32	s_journal_dev;		/* device number of journal file */
1315 	__le32	s_last_orphan;		/* start of list of inodes to delete */
1316 	__le32	s_hash_seed[4];		/* HTREE hash seed */
1317 	__u8	s_def_hash_version;	/* Default hash version to use */
1318 	__u8	s_jnl_backup_type;
1319 	__le16  s_desc_size;		/* size of group descriptor */
1320 /*100*/	__le32	s_default_mount_opts;
1321 	__le32	s_first_meta_bg;	/* First metablock block group */
1322 	__le32	s_mkfs_time;		/* When the filesystem was created */
1323 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
1324 	/* 64bit support valid if EXT4_FEATURE_INCOMPAT_64BIT */
1325 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
1326 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
1327 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
1328 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
1329 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
1330 	__le32	s_flags;		/* Miscellaneous flags */
1331 	__le16  s_raid_stride;		/* RAID stride */
1332 	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1333 	__le64  s_mmp_block;            /* Block for multi-mount protection */
1334 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1335 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
1336 	__u8	s_checksum_type;	/* metadata checksum algorithm used */
1337 	__u8	s_encryption_level;	/* versioning level for encryption */
1338 	__u8	s_reserved_pad;		/* Padding to next 32bits */
1339 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1340 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
1341 	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
1342 	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
1343 					      snapshot's future use */
1344 	__le32	s_snapshot_list;	/* inode number of the head of the
1345 					   on-disk snapshot list */
1346 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1347 	__le32	s_error_count;		/* number of fs errors */
1348 	__le32	s_first_error_time;	/* first time an error happened */
1349 	__le32	s_first_error_ino;	/* inode involved in first error */
1350 	__le64	s_first_error_block;	/* block involved of first error */
1351 	__u8	s_first_error_func[32] __nonstring;	/* function where the error happened */
1352 	__le32	s_first_error_line;	/* line number where error happened */
1353 	__le32	s_last_error_time;	/* most recent time of an error */
1354 	__le32	s_last_error_ino;	/* inode involved in last error */
1355 	__le32	s_last_error_line;	/* line number where error happened */
1356 	__le64	s_last_error_block;	/* block involved of last error */
1357 	__u8	s_last_error_func[32] __nonstring;	/* function where the error happened */
1358 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1359 	__u8	s_mount_opts[64];
1360 	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
1361 	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
1362 	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
1363 	__le32	s_backup_bgs[2];	/* groups with sparse_super2 SBs */
1364 	__u8	s_encrypt_algos[4];	/* Encryption algorithms in use  */
1365 	__u8	s_encrypt_pw_salt[16];	/* Salt used for string2key algorithm */
1366 	__le32	s_lpf_ino;		/* Location of the lost+found inode */
1367 	__le32	s_prj_quota_inum;	/* inode for tracking project quota */
1368 	__le32	s_checksum_seed;	/* crc32c(uuid) if csum_seed set */
1369 	__u8	s_wtime_hi;
1370 	__u8	s_mtime_hi;
1371 	__u8	s_mkfs_time_hi;
1372 	__u8	s_lastcheck_hi;
1373 	__u8	s_first_error_time_hi;
1374 	__u8	s_last_error_time_hi;
1375 	__u8	s_first_error_errcode;
1376 	__u8    s_last_error_errcode;
1377 	__le16  s_encoding;		/* Filename charset encoding */
1378 	__le16  s_encoding_flags;	/* Filename charset encoding flags */
1379 	__le32  s_orphan_file_inum;	/* Inode for tracking orphan inodes */
1380 	__le32	s_reserved[94];		/* Padding to the end of the block */
1381 	__le32	s_checksum;		/* crc32c(superblock) */
1382 };
1383 
1384 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1385 
1386 #ifdef __KERNEL__
1387 
1388 /* Number of quota types we support */
1389 #define EXT4_MAXQUOTAS 3
1390 
1391 #define EXT4_ENC_UTF8_12_1	1
1392 
1393 /* Types of ext4 journal triggers */
1394 enum ext4_journal_trigger_type {
1395 	EXT4_JTR_ORPHAN_FILE,
1396 	EXT4_JTR_NONE	/* This must be the last entry for indexing to work! */
1397 };
1398 
1399 #define EXT4_JOURNAL_TRIGGER_COUNT EXT4_JTR_NONE
1400 
1401 struct ext4_journal_trigger {
1402 	struct jbd2_buffer_trigger_type tr_triggers;
1403 	struct super_block *sb;
1404 };
1405 
1406 static inline struct ext4_journal_trigger *EXT4_TRIGGER(
1407 				struct jbd2_buffer_trigger_type *trigger)
1408 {
1409 	return container_of(trigger, struct ext4_journal_trigger, tr_triggers);
1410 }
1411 
1412 #define EXT4_ORPHAN_BLOCK_MAGIC 0x0b10ca04
1413 
1414 /* Structure at the tail of orphan block */
1415 struct ext4_orphan_block_tail {
1416 	__le32 ob_magic;
1417 	__le32 ob_checksum;
1418 };
1419 
1420 static inline int ext4_inodes_per_orphan_block(struct super_block *sb)
1421 {
1422 	return (sb->s_blocksize - sizeof(struct ext4_orphan_block_tail)) /
1423 			sizeof(u32);
1424 }
1425 
1426 struct ext4_orphan_block {
1427 	atomic_t ob_free_entries;	/* Number of free orphan entries in block */
1428 	struct buffer_head *ob_bh;	/* Buffer for orphan block */
1429 };
1430 
1431 /*
1432  * Info about orphan file.
1433  */
1434 struct ext4_orphan_info {
1435 	int of_blocks;			/* Number of orphan blocks in a file */
1436 	__u32 of_csum_seed;		/* Checksum seed for orphan file */
1437 	struct ext4_orphan_block *of_binfo;	/* Array with info about orphan
1438 						 * file blocks */
1439 };
1440 
1441 /*
1442  * fourth extended-fs super-block data in memory
1443  */
1444 struct ext4_sb_info {
1445 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
1446 	unsigned long s_inodes_per_block;/* Number of inodes per block */
1447 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
1448 	unsigned long s_clusters_per_group; /* Number of clusters in a group */
1449 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
1450 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
1451 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
1452 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
1453 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1454 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1455 	unsigned long s_overhead;  /* # of fs overhead clusters */
1456 	unsigned int s_cluster_ratio;	/* Number of blocks per cluster */
1457 	unsigned int s_cluster_bits;	/* log2 of s_cluster_ratio */
1458 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
1459 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
1460 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
1461 	struct buffer_head * __rcu *s_group_desc;
1462 	unsigned int s_mount_opt;
1463 	unsigned int s_mount_opt2;
1464 	unsigned long s_mount_flags;
1465 	unsigned int s_def_mount_opt;
1466 	unsigned int s_def_mount_opt2;
1467 	ext4_fsblk_t s_sb_block;
1468 	atomic64_t s_resv_clusters;
1469 	kuid_t s_resuid;
1470 	kgid_t s_resgid;
1471 	unsigned short s_mount_state;
1472 	unsigned short s_pad;
1473 	int s_addr_per_block_bits;
1474 	int s_desc_per_block_bits;
1475 	int s_inode_size;
1476 	int s_first_ino;
1477 	unsigned int s_inode_readahead_blks;
1478 	unsigned int s_inode_goal;
1479 	u32 s_hash_seed[4];
1480 	int s_def_hash_version;
1481 	int s_hash_unsigned;	/* 3 if hash should be unsigned, 0 if not */
1482 	struct percpu_counter s_freeclusters_counter;
1483 	struct percpu_counter s_freeinodes_counter;
1484 	struct percpu_counter s_dirs_counter;
1485 	struct percpu_counter s_dirtyclusters_counter;
1486 	struct percpu_counter s_sra_exceeded_retry_limit;
1487 	struct blockgroup_lock *s_blockgroup_lock;
1488 	struct proc_dir_entry *s_proc;
1489 	struct kobject s_kobj;
1490 	struct completion s_kobj_unregister;
1491 	struct super_block *s_sb;
1492 	struct buffer_head *s_mmp_bh;
1493 
1494 	/* Journaling */
1495 	struct journal_s *s_journal;
1496 	unsigned long s_ext4_flags;		/* Ext4 superblock flags */
1497 	struct mutex s_orphan_lock;	/* Protects on disk list changes */
1498 	struct list_head s_orphan;	/* List of orphaned inodes in on disk
1499 					   list */
1500 	struct ext4_orphan_info s_orphan_info;
1501 	unsigned long s_commit_interval;
1502 	u32 s_max_batch_time;
1503 	u32 s_min_batch_time;
1504 	struct block_device *s_journal_bdev;
1505 #ifdef CONFIG_QUOTA
1506 	/* Names of quota files with journalled quota */
1507 	char __rcu *s_qf_names[EXT4_MAXQUOTAS];
1508 	int s_jquota_fmt;			/* Format of quota to use */
1509 #endif
1510 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1511 	struct ext4_system_blocks __rcu *s_system_blks;
1512 
1513 #ifdef EXTENTS_STATS
1514 	/* ext4 extents stats */
1515 	unsigned long s_ext_min;
1516 	unsigned long s_ext_max;
1517 	unsigned long s_depth_max;
1518 	spinlock_t s_ext_stats_lock;
1519 	unsigned long s_ext_blocks;
1520 	unsigned long s_ext_extents;
1521 #endif
1522 
1523 	/* for buddy allocator */
1524 	struct ext4_group_info ** __rcu *s_group_info;
1525 	struct inode *s_buddy_cache;
1526 	spinlock_t s_md_lock;
1527 	unsigned short *s_mb_offsets;
1528 	unsigned int *s_mb_maxs;
1529 	unsigned int s_group_info_size;
1530 	unsigned int s_mb_free_pending;
1531 	struct list_head s_freed_data_list;	/* List of blocks to be freed
1532 						   after commit completed */
1533 	struct list_head s_discard_list;
1534 	struct work_struct s_discard_work;
1535 	atomic_t s_retry_alloc_pending;
1536 	struct list_head *s_mb_avg_fragment_size;
1537 	rwlock_t *s_mb_avg_fragment_size_locks;
1538 	struct list_head *s_mb_largest_free_orders;
1539 	rwlock_t *s_mb_largest_free_orders_locks;
1540 
1541 	/* tunables */
1542 	unsigned long s_stripe;
1543 	unsigned int s_mb_max_linear_groups;
1544 	unsigned int s_mb_stream_request;
1545 	unsigned int s_mb_max_to_scan;
1546 	unsigned int s_mb_min_to_scan;
1547 	unsigned int s_mb_stats;
1548 	unsigned int s_mb_order2_reqs;
1549 	unsigned int s_mb_group_prealloc;
1550 	unsigned int s_max_dir_size_kb;
1551 	/* where last allocation was done - for stream allocation */
1552 	unsigned long s_mb_last_group;
1553 	unsigned long s_mb_last_start;
1554 	unsigned int s_mb_prefetch;
1555 	unsigned int s_mb_prefetch_limit;
1556 	unsigned int s_mb_cr1_5_max_trim_order;
1557 
1558 	/* stats for buddy allocator */
1559 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1560 	atomic_t s_bal_success;	/* we found long enough chunks */
1561 	atomic_t s_bal_allocated;	/* in blocks */
1562 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1563 	atomic_t s_bal_cX_ex_scanned[EXT4_MB_NUM_CRS];	/* total extents scanned */
1564 	atomic_t s_bal_groups_scanned;	/* number of groups scanned */
1565 	atomic_t s_bal_goals;	/* goal hits */
1566 	atomic_t s_bal_len_goals;	/* len goal hits */
1567 	atomic_t s_bal_breaks;	/* too long searches */
1568 	atomic_t s_bal_2orders;	/* 2^order hits */
1569 	atomic_t s_bal_cr0_bad_suggestions;
1570 	atomic_t s_bal_cr1_bad_suggestions;
1571 	atomic_t s_bal_cr1_5_bad_suggestions;
1572 	atomic64_t s_bal_cX_groups_considered[EXT4_MB_NUM_CRS];
1573 	atomic64_t s_bal_cX_hits[EXT4_MB_NUM_CRS];
1574 	atomic64_t s_bal_cX_failed[EXT4_MB_NUM_CRS];		/* cX loop didn't find blocks */
1575 	atomic_t s_mb_buddies_generated;	/* number of buddies generated */
1576 	atomic64_t s_mb_generation_time;
1577 	atomic_t s_mb_lost_chunks;
1578 	atomic_t s_mb_preallocated;
1579 	atomic_t s_mb_discarded;
1580 	atomic_t s_lock_busy;
1581 
1582 	/* locality groups */
1583 	struct ext4_locality_group __percpu *s_locality_groups;
1584 
1585 	/* for write statistics */
1586 	unsigned long s_sectors_written_start;
1587 	u64 s_kbytes_written;
1588 
1589 	/* the size of zero-out chunk */
1590 	unsigned int s_extent_max_zeroout_kb;
1591 
1592 	unsigned int s_log_groups_per_flex;
1593 	struct flex_groups * __rcu *s_flex_groups;
1594 	ext4_group_t s_flex_groups_allocated;
1595 
1596 	/* workqueue for reserved extent conversions (buffered io) */
1597 	struct workqueue_struct *rsv_conversion_wq;
1598 
1599 	/* timer for periodic error stats printing */
1600 	struct timer_list s_err_report;
1601 
1602 	/* Lazy inode table initialization info */
1603 	struct ext4_li_request *s_li_request;
1604 	/* Wait multiplier for lazy initialization thread */
1605 	unsigned int s_li_wait_mult;
1606 
1607 	/* Kernel thread for multiple mount protection */
1608 	struct task_struct *s_mmp_tsk;
1609 
1610 	/* record the last minlen when FITRIM is called. */
1611 	unsigned long s_last_trim_minblks;
1612 
1613 	/* Reference to checksum algorithm driver via cryptoapi */
1614 	struct crypto_shash *s_chksum_driver;
1615 
1616 	/* Precomputed FS UUID checksum for seeding other checksums */
1617 	__u32 s_csum_seed;
1618 
1619 	/* Reclaim extents from extent status tree */
1620 	struct shrinker s_es_shrinker;
1621 	struct list_head s_es_list;	/* List of inodes with reclaimable extents */
1622 	long s_es_nr_inode;
1623 	struct ext4_es_stats s_es_stats;
1624 	struct mb_cache *s_ea_block_cache;
1625 	struct mb_cache *s_ea_inode_cache;
1626 	spinlock_t s_es_lock ____cacheline_aligned_in_smp;
1627 
1628 	/* Journal triggers for checksum computation */
1629 	struct ext4_journal_trigger s_journal_triggers[EXT4_JOURNAL_TRIGGER_COUNT];
1630 
1631 	/* Ratelimit ext4 messages. */
1632 	struct ratelimit_state s_err_ratelimit_state;
1633 	struct ratelimit_state s_warning_ratelimit_state;
1634 	struct ratelimit_state s_msg_ratelimit_state;
1635 	atomic_t s_warning_count;
1636 	atomic_t s_msg_count;
1637 
1638 	/* Encryption policy for '-o test_dummy_encryption' */
1639 	struct fscrypt_dummy_policy s_dummy_enc_policy;
1640 
1641 	/*
1642 	 * Barrier between writepages ops and changing any inode's JOURNAL_DATA
1643 	 * or EXTENTS flag.
1644 	 */
1645 	struct percpu_rw_semaphore s_writepages_rwsem;
1646 	struct dax_device *s_daxdev;
1647 	u64 s_dax_part_off;
1648 #ifdef CONFIG_EXT4_DEBUG
1649 	unsigned long s_simulate_fail;
1650 #endif
1651 	/* Record the errseq of the backing block device */
1652 	errseq_t s_bdev_wb_err;
1653 	spinlock_t s_bdev_wb_lock;
1654 
1655 	/* Information about errors that happened during this mount */
1656 	spinlock_t s_error_lock;
1657 	int s_add_error_count;
1658 	int s_first_error_code;
1659 	__u32 s_first_error_line;
1660 	__u32 s_first_error_ino;
1661 	__u64 s_first_error_block;
1662 	const char *s_first_error_func;
1663 	time64_t s_first_error_time;
1664 	int s_last_error_code;
1665 	__u32 s_last_error_line;
1666 	__u32 s_last_error_ino;
1667 	__u64 s_last_error_block;
1668 	const char *s_last_error_func;
1669 	time64_t s_last_error_time;
1670 	/*
1671 	 * If we are in a context where we cannot update error information in
1672 	 * the on-disk superblock, we queue this work to do it.
1673 	 */
1674 	struct work_struct s_error_work;
1675 
1676 	/* Ext4 fast commit sub transaction ID */
1677 	atomic_t s_fc_subtid;
1678 
1679 	/*
1680 	 * After commit starts, the main queue gets locked, and the further
1681 	 * updates get added in the staging queue.
1682 	 */
1683 #define FC_Q_MAIN	0
1684 #define FC_Q_STAGING	1
1685 	struct list_head s_fc_q[2];	/* Inodes staged for fast commit
1686 					 * that have data changes in them.
1687 					 */
1688 	struct list_head s_fc_dentry_q[2];	/* directory entry updates */
1689 	unsigned int s_fc_bytes;
1690 	/*
1691 	 * Main fast commit lock. This lock protects accesses to the
1692 	 * following fields:
1693 	 * ei->i_fc_list, s_fc_dentry_q, s_fc_q, s_fc_bytes, s_fc_bh.
1694 	 */
1695 	spinlock_t s_fc_lock;
1696 	struct buffer_head *s_fc_bh;
1697 	struct ext4_fc_stats s_fc_stats;
1698 	tid_t s_fc_ineligible_tid;
1699 #ifdef CONFIG_EXT4_DEBUG
1700 	int s_fc_debug_max_replay;
1701 #endif
1702 	struct ext4_fc_replay_state s_fc_replay_state;
1703 };
1704 
1705 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1706 {
1707 	return sb->s_fs_info;
1708 }
1709 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1710 {
1711 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1712 }
1713 
1714 static inline int ext4_writepages_down_read(struct super_block *sb)
1715 {
1716 	percpu_down_read(&EXT4_SB(sb)->s_writepages_rwsem);
1717 	return memalloc_nofs_save();
1718 }
1719 
1720 static inline void ext4_writepages_up_read(struct super_block *sb, int ctx)
1721 {
1722 	memalloc_nofs_restore(ctx);
1723 	percpu_up_read(&EXT4_SB(sb)->s_writepages_rwsem);
1724 }
1725 
1726 static inline int ext4_writepages_down_write(struct super_block *sb)
1727 {
1728 	percpu_down_write(&EXT4_SB(sb)->s_writepages_rwsem);
1729 	return memalloc_nofs_save();
1730 }
1731 
1732 static inline void ext4_writepages_up_write(struct super_block *sb, int ctx)
1733 {
1734 	memalloc_nofs_restore(ctx);
1735 	percpu_up_write(&EXT4_SB(sb)->s_writepages_rwsem);
1736 }
1737 
1738 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1739 {
1740 	return ino == EXT4_ROOT_INO ||
1741 		(ino >= EXT4_FIRST_INO(sb) &&
1742 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1743 }
1744 
1745 /*
1746  * Returns: sbi->field[index]
1747  * Used to access an array element from the following sbi fields which require
1748  * rcu protection to avoid dereferencing an invalid pointer due to reassignment
1749  * - s_group_desc
1750  * - s_group_info
1751  * - s_flex_group
1752  */
1753 #define sbi_array_rcu_deref(sbi, field, index)				   \
1754 ({									   \
1755 	typeof(*((sbi)->field)) _v;					   \
1756 	rcu_read_lock();						   \
1757 	_v = ((typeof(_v)*)rcu_dereference((sbi)->field))[index];	   \
1758 	rcu_read_unlock();						   \
1759 	_v;								   \
1760 })
1761 
1762 /*
1763  * run-time mount flags
1764  */
1765 enum {
1766 	EXT4_MF_MNTDIR_SAMPLED,
1767 	EXT4_MF_FS_ABORTED,	/* Fatal error detected */
1768 	EXT4_MF_FC_INELIGIBLE	/* Fast commit ineligible */
1769 };
1770 
1771 static inline void ext4_set_mount_flag(struct super_block *sb, int bit)
1772 {
1773 	set_bit(bit, &EXT4_SB(sb)->s_mount_flags);
1774 }
1775 
1776 static inline void ext4_clear_mount_flag(struct super_block *sb, int bit)
1777 {
1778 	clear_bit(bit, &EXT4_SB(sb)->s_mount_flags);
1779 }
1780 
1781 static inline int ext4_test_mount_flag(struct super_block *sb, int bit)
1782 {
1783 	return test_bit(bit, &EXT4_SB(sb)->s_mount_flags);
1784 }
1785 
1786 
1787 /*
1788  * Simulate_fail codes
1789  */
1790 #define EXT4_SIM_BBITMAP_EIO	1
1791 #define EXT4_SIM_BBITMAP_CRC	2
1792 #define EXT4_SIM_IBITMAP_EIO	3
1793 #define EXT4_SIM_IBITMAP_CRC	4
1794 #define EXT4_SIM_INODE_EIO	5
1795 #define EXT4_SIM_INODE_CRC	6
1796 #define EXT4_SIM_DIRBLOCK_EIO	7
1797 #define EXT4_SIM_DIRBLOCK_CRC	8
1798 
1799 static inline bool ext4_simulate_fail(struct super_block *sb,
1800 				     unsigned long code)
1801 {
1802 #ifdef CONFIG_EXT4_DEBUG
1803 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1804 
1805 	if (unlikely(sbi->s_simulate_fail == code)) {
1806 		sbi->s_simulate_fail = 0;
1807 		return true;
1808 	}
1809 #endif
1810 	return false;
1811 }
1812 
1813 static inline void ext4_simulate_fail_bh(struct super_block *sb,
1814 					 struct buffer_head *bh,
1815 					 unsigned long code)
1816 {
1817 	if (!IS_ERR(bh) && ext4_simulate_fail(sb, code))
1818 		clear_buffer_uptodate(bh);
1819 }
1820 
1821 /*
1822  * Error number codes for s_{first,last}_error_errno
1823  *
1824  * Linux errno numbers are architecture specific, so we need to translate
1825  * them into something which is architecture independent.   We don't define
1826  * codes for all errno's; just the ones which are most likely to be the cause
1827  * of an ext4_error() call.
1828  */
1829 #define EXT4_ERR_UNKNOWN	 1
1830 #define EXT4_ERR_EIO		 2
1831 #define EXT4_ERR_ENOMEM		 3
1832 #define EXT4_ERR_EFSBADCRC	 4
1833 #define EXT4_ERR_EFSCORRUPTED	 5
1834 #define EXT4_ERR_ENOSPC		 6
1835 #define EXT4_ERR_ENOKEY		 7
1836 #define EXT4_ERR_EROFS		 8
1837 #define EXT4_ERR_EFBIG		 9
1838 #define EXT4_ERR_EEXIST		10
1839 #define EXT4_ERR_ERANGE		11
1840 #define EXT4_ERR_EOVERFLOW	12
1841 #define EXT4_ERR_EBUSY		13
1842 #define EXT4_ERR_ENOTDIR	14
1843 #define EXT4_ERR_ENOTEMPTY	15
1844 #define EXT4_ERR_ESHUTDOWN	16
1845 #define EXT4_ERR_EFAULT		17
1846 
1847 /*
1848  * Inode dynamic state flags
1849  */
1850 enum {
1851 	EXT4_STATE_NEW,			/* inode is newly created */
1852 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1853 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1854 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1855 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1856 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1857 	EXT4_STATE_MAY_INLINE_DATA,	/* may have in-inode data */
1858 	EXT4_STATE_EXT_PRECACHED,	/* extents have been precached */
1859 	EXT4_STATE_LUSTRE_EA_INODE,	/* Lustre-style ea_inode */
1860 	EXT4_STATE_VERITY_IN_PROGRESS,	/* building fs-verity Merkle tree */
1861 	EXT4_STATE_FC_COMMITTING,	/* Fast commit ongoing */
1862 	EXT4_STATE_ORPHAN_FILE,		/* Inode orphaned in orphan file */
1863 };
1864 
1865 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
1866 static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
1867 {									\
1868 	return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);	\
1869 }									\
1870 static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
1871 {									\
1872 	set_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1873 }									\
1874 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1875 {									\
1876 	clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1877 }
1878 
1879 /* Add these declarations here only so that these functions can be
1880  * found by name.  Otherwise, they are very hard to locate. */
1881 static inline int ext4_test_inode_flag(struct inode *inode, int bit);
1882 static inline void ext4_set_inode_flag(struct inode *inode, int bit);
1883 static inline void ext4_clear_inode_flag(struct inode *inode, int bit);
1884 EXT4_INODE_BIT_FNS(flag, flags, 0)
1885 
1886 /* Add these declarations here only so that these functions can be
1887  * found by name.  Otherwise, they are very hard to locate. */
1888 static inline int ext4_test_inode_state(struct inode *inode, int bit);
1889 static inline void ext4_set_inode_state(struct inode *inode, int bit);
1890 static inline void ext4_clear_inode_state(struct inode *inode, int bit);
1891 #if (BITS_PER_LONG < 64)
1892 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1893 
1894 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1895 {
1896 	(ei)->i_state_flags = 0;
1897 }
1898 #else
1899 EXT4_INODE_BIT_FNS(state, flags, 32)
1900 
1901 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1902 {
1903 	/* We depend on the fact that callers will set i_flags */
1904 }
1905 #endif
1906 #else
1907 /* Assume that user mode programs are passing in an ext4fs superblock, not
1908  * a kernel struct super_block.  This will allow us to call the feature-test
1909  * macros from user land. */
1910 #define EXT4_SB(sb)	(sb)
1911 #endif
1912 
1913 static inline bool ext4_verity_in_progress(struct inode *inode)
1914 {
1915 	return IS_ENABLED(CONFIG_FS_VERITY) &&
1916 	       ext4_test_inode_state(inode, EXT4_STATE_VERITY_IN_PROGRESS);
1917 }
1918 
1919 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1920 
1921 /*
1922  * Codes for operating systems
1923  */
1924 #define EXT4_OS_LINUX		0
1925 #define EXT4_OS_HURD		1
1926 #define EXT4_OS_MASIX		2
1927 #define EXT4_OS_FREEBSD		3
1928 #define EXT4_OS_LITES		4
1929 
1930 /*
1931  * Revision levels
1932  */
1933 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1934 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1935 
1936 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1937 
1938 #define EXT4_GOOD_OLD_INODE_SIZE 128
1939 
1940 #define EXT4_EXTRA_TIMESTAMP_MAX	(((s64)1 << 34) - 1  + S32_MIN)
1941 #define EXT4_NON_EXTRA_TIMESTAMP_MAX	S32_MAX
1942 #define EXT4_TIMESTAMP_MIN		S32_MIN
1943 
1944 /*
1945  * Feature set definitions
1946  */
1947 
1948 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1949 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1950 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1951 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1952 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1953 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1954 #define EXT4_FEATURE_COMPAT_SPARSE_SUPER2	0x0200
1955 /*
1956  * The reason why "FAST_COMMIT" is a compat feature is that, FS becomes
1957  * incompatible only if fast commit blocks are present in the FS. Since we
1958  * clear the journal (and thus the fast commit blocks), we don't mark FS as
1959  * incompatible. We also have a JBD2 incompat feature, which gets set when
1960  * there are fast commit blocks present in the journal.
1961  */
1962 #define EXT4_FEATURE_COMPAT_FAST_COMMIT		0x0400
1963 #define EXT4_FEATURE_COMPAT_STABLE_INODES	0x0800
1964 #define EXT4_FEATURE_COMPAT_ORPHAN_FILE		0x1000	/* Orphan file exists */
1965 
1966 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1967 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1968 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1969 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1970 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1971 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1972 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1973 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
1974 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
1975 /*
1976  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1977  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1978  * all other data structures' checksums.  However, the METADATA_CSUM and
1979  * GDT_CSUM bits are mutually exclusive.
1980  */
1981 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
1982 #define EXT4_FEATURE_RO_COMPAT_READONLY		0x1000
1983 #define EXT4_FEATURE_RO_COMPAT_PROJECT		0x2000
1984 #define EXT4_FEATURE_RO_COMPAT_VERITY		0x8000
1985 #define EXT4_FEATURE_RO_COMPAT_ORPHAN_PRESENT	0x10000 /* Orphan file may be
1986 							   non-empty */
1987 
1988 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1989 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1990 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1991 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1992 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1993 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1994 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1995 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1996 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1997 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1998 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1999 #define EXT4_FEATURE_INCOMPAT_CSUM_SEED		0x2000
2000 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
2001 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA	0x8000 /* data in inode */
2002 #define EXT4_FEATURE_INCOMPAT_ENCRYPT		0x10000
2003 #define EXT4_FEATURE_INCOMPAT_CASEFOLD		0x20000
2004 
2005 extern void ext4_update_dynamic_rev(struct super_block *sb);
2006 
2007 #define EXT4_FEATURE_COMPAT_FUNCS(name, flagname) \
2008 static inline bool ext4_has_feature_##name(struct super_block *sb) \
2009 { \
2010 	return ((EXT4_SB(sb)->s_es->s_feature_compat & \
2011 		cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname)) != 0); \
2012 } \
2013 static inline void ext4_set_feature_##name(struct super_block *sb) \
2014 { \
2015 	ext4_update_dynamic_rev(sb); \
2016 	EXT4_SB(sb)->s_es->s_feature_compat |= \
2017 		cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname); \
2018 } \
2019 static inline void ext4_clear_feature_##name(struct super_block *sb) \
2020 { \
2021 	EXT4_SB(sb)->s_es->s_feature_compat &= \
2022 		~cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname); \
2023 }
2024 
2025 #define EXT4_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
2026 static inline bool ext4_has_feature_##name(struct super_block *sb) \
2027 { \
2028 	return ((EXT4_SB(sb)->s_es->s_feature_ro_compat & \
2029 		cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname)) != 0); \
2030 } \
2031 static inline void ext4_set_feature_##name(struct super_block *sb) \
2032 { \
2033 	ext4_update_dynamic_rev(sb); \
2034 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= \
2035 		cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname); \
2036 } \
2037 static inline void ext4_clear_feature_##name(struct super_block *sb) \
2038 { \
2039 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= \
2040 		~cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname); \
2041 }
2042 
2043 #define EXT4_FEATURE_INCOMPAT_FUNCS(name, flagname) \
2044 static inline bool ext4_has_feature_##name(struct super_block *sb) \
2045 { \
2046 	return ((EXT4_SB(sb)->s_es->s_feature_incompat & \
2047 		cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname)) != 0); \
2048 } \
2049 static inline void ext4_set_feature_##name(struct super_block *sb) \
2050 { \
2051 	ext4_update_dynamic_rev(sb); \
2052 	EXT4_SB(sb)->s_es->s_feature_incompat |= \
2053 		cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname); \
2054 } \
2055 static inline void ext4_clear_feature_##name(struct super_block *sb) \
2056 { \
2057 	EXT4_SB(sb)->s_es->s_feature_incompat &= \
2058 		~cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname); \
2059 }
2060 
2061 EXT4_FEATURE_COMPAT_FUNCS(dir_prealloc,		DIR_PREALLOC)
2062 EXT4_FEATURE_COMPAT_FUNCS(imagic_inodes,	IMAGIC_INODES)
2063 EXT4_FEATURE_COMPAT_FUNCS(journal,		HAS_JOURNAL)
2064 EXT4_FEATURE_COMPAT_FUNCS(xattr,		EXT_ATTR)
2065 EXT4_FEATURE_COMPAT_FUNCS(resize_inode,		RESIZE_INODE)
2066 EXT4_FEATURE_COMPAT_FUNCS(dir_index,		DIR_INDEX)
2067 EXT4_FEATURE_COMPAT_FUNCS(sparse_super2,	SPARSE_SUPER2)
2068 EXT4_FEATURE_COMPAT_FUNCS(fast_commit,		FAST_COMMIT)
2069 EXT4_FEATURE_COMPAT_FUNCS(stable_inodes,	STABLE_INODES)
2070 EXT4_FEATURE_COMPAT_FUNCS(orphan_file,		ORPHAN_FILE)
2071 
2072 EXT4_FEATURE_RO_COMPAT_FUNCS(sparse_super,	SPARSE_SUPER)
2073 EXT4_FEATURE_RO_COMPAT_FUNCS(large_file,	LARGE_FILE)
2074 EXT4_FEATURE_RO_COMPAT_FUNCS(btree_dir,		BTREE_DIR)
2075 EXT4_FEATURE_RO_COMPAT_FUNCS(huge_file,		HUGE_FILE)
2076 EXT4_FEATURE_RO_COMPAT_FUNCS(gdt_csum,		GDT_CSUM)
2077 EXT4_FEATURE_RO_COMPAT_FUNCS(dir_nlink,		DIR_NLINK)
2078 EXT4_FEATURE_RO_COMPAT_FUNCS(extra_isize,	EXTRA_ISIZE)
2079 EXT4_FEATURE_RO_COMPAT_FUNCS(quota,		QUOTA)
2080 EXT4_FEATURE_RO_COMPAT_FUNCS(bigalloc,		BIGALLOC)
2081 EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum,	METADATA_CSUM)
2082 EXT4_FEATURE_RO_COMPAT_FUNCS(readonly,		READONLY)
2083 EXT4_FEATURE_RO_COMPAT_FUNCS(project,		PROJECT)
2084 EXT4_FEATURE_RO_COMPAT_FUNCS(verity,		VERITY)
2085 EXT4_FEATURE_RO_COMPAT_FUNCS(orphan_present,	ORPHAN_PRESENT)
2086 
2087 EXT4_FEATURE_INCOMPAT_FUNCS(compression,	COMPRESSION)
2088 EXT4_FEATURE_INCOMPAT_FUNCS(filetype,		FILETYPE)
2089 EXT4_FEATURE_INCOMPAT_FUNCS(journal_needs_recovery,	RECOVER)
2090 EXT4_FEATURE_INCOMPAT_FUNCS(journal_dev,	JOURNAL_DEV)
2091 EXT4_FEATURE_INCOMPAT_FUNCS(meta_bg,		META_BG)
2092 EXT4_FEATURE_INCOMPAT_FUNCS(extents,		EXTENTS)
2093 EXT4_FEATURE_INCOMPAT_FUNCS(64bit,		64BIT)
2094 EXT4_FEATURE_INCOMPAT_FUNCS(mmp,		MMP)
2095 EXT4_FEATURE_INCOMPAT_FUNCS(flex_bg,		FLEX_BG)
2096 EXT4_FEATURE_INCOMPAT_FUNCS(ea_inode,		EA_INODE)
2097 EXT4_FEATURE_INCOMPAT_FUNCS(dirdata,		DIRDATA)
2098 EXT4_FEATURE_INCOMPAT_FUNCS(csum_seed,		CSUM_SEED)
2099 EXT4_FEATURE_INCOMPAT_FUNCS(largedir,		LARGEDIR)
2100 EXT4_FEATURE_INCOMPAT_FUNCS(inline_data,	INLINE_DATA)
2101 EXT4_FEATURE_INCOMPAT_FUNCS(encrypt,		ENCRYPT)
2102 EXT4_FEATURE_INCOMPAT_FUNCS(casefold,		CASEFOLD)
2103 
2104 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
2105 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
2106 					 EXT4_FEATURE_INCOMPAT_META_BG)
2107 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
2108 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
2109 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
2110 
2111 #define EXT3_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
2112 #define EXT3_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
2113 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
2114 					 EXT4_FEATURE_INCOMPAT_META_BG)
2115 #define EXT3_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
2116 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
2117 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
2118 
2119 #define EXT4_FEATURE_COMPAT_SUPP	(EXT4_FEATURE_COMPAT_EXT_ATTR| \
2120 					 EXT4_FEATURE_COMPAT_ORPHAN_FILE)
2121 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
2122 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
2123 					 EXT4_FEATURE_INCOMPAT_META_BG| \
2124 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
2125 					 EXT4_FEATURE_INCOMPAT_64BIT| \
2126 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
2127 					 EXT4_FEATURE_INCOMPAT_EA_INODE| \
2128 					 EXT4_FEATURE_INCOMPAT_MMP | \
2129 					 EXT4_FEATURE_INCOMPAT_INLINE_DATA | \
2130 					 EXT4_FEATURE_INCOMPAT_ENCRYPT | \
2131 					 EXT4_FEATURE_INCOMPAT_CASEFOLD | \
2132 					 EXT4_FEATURE_INCOMPAT_CSUM_SEED | \
2133 					 EXT4_FEATURE_INCOMPAT_LARGEDIR)
2134 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
2135 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
2136 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
2137 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
2138 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
2139 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
2140 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
2141 					 EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
2142 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
2143 					 EXT4_FEATURE_RO_COMPAT_QUOTA |\
2144 					 EXT4_FEATURE_RO_COMPAT_PROJECT |\
2145 					 EXT4_FEATURE_RO_COMPAT_VERITY |\
2146 					 EXT4_FEATURE_RO_COMPAT_ORPHAN_PRESENT)
2147 
2148 #define EXTN_FEATURE_FUNCS(ver) \
2149 static inline bool ext4_has_unknown_ext##ver##_compat_features(struct super_block *sb) \
2150 { \
2151 	return ((EXT4_SB(sb)->s_es->s_feature_compat & \
2152 		cpu_to_le32(~EXT##ver##_FEATURE_COMPAT_SUPP)) != 0); \
2153 } \
2154 static inline bool ext4_has_unknown_ext##ver##_ro_compat_features(struct super_block *sb) \
2155 { \
2156 	return ((EXT4_SB(sb)->s_es->s_feature_ro_compat & \
2157 		cpu_to_le32(~EXT##ver##_FEATURE_RO_COMPAT_SUPP)) != 0); \
2158 } \
2159 static inline bool ext4_has_unknown_ext##ver##_incompat_features(struct super_block *sb) \
2160 { \
2161 	return ((EXT4_SB(sb)->s_es->s_feature_incompat & \
2162 		cpu_to_le32(~EXT##ver##_FEATURE_INCOMPAT_SUPP)) != 0); \
2163 }
2164 
2165 EXTN_FEATURE_FUNCS(2)
2166 EXTN_FEATURE_FUNCS(3)
2167 EXTN_FEATURE_FUNCS(4)
2168 
2169 static inline bool ext4_has_compat_features(struct super_block *sb)
2170 {
2171 	return (EXT4_SB(sb)->s_es->s_feature_compat != 0);
2172 }
2173 static inline bool ext4_has_ro_compat_features(struct super_block *sb)
2174 {
2175 	return (EXT4_SB(sb)->s_es->s_feature_ro_compat != 0);
2176 }
2177 static inline bool ext4_has_incompat_features(struct super_block *sb)
2178 {
2179 	return (EXT4_SB(sb)->s_es->s_feature_incompat != 0);
2180 }
2181 
2182 extern int ext4_feature_set_ok(struct super_block *sb, int readonly);
2183 
2184 /*
2185  * Superblock flags
2186  */
2187 #define EXT4_FLAGS_RESIZING	0
2188 #define EXT4_FLAGS_SHUTDOWN	1
2189 #define EXT4_FLAGS_BDEV_IS_DAX	2
2190 
2191 static inline int ext4_forced_shutdown(struct ext4_sb_info *sbi)
2192 {
2193 	return test_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);
2194 }
2195 
2196 /*
2197  * Default values for user and/or group using reserved blocks
2198  */
2199 #define	EXT4_DEF_RESUID		0
2200 #define	EXT4_DEF_RESGID		0
2201 
2202 /*
2203  * Default project ID
2204  */
2205 #define	EXT4_DEF_PROJID		0
2206 
2207 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
2208 
2209 /*
2210  * Default mount options
2211  */
2212 #define EXT4_DEFM_DEBUG		0x0001
2213 #define EXT4_DEFM_BSDGROUPS	0x0002
2214 #define EXT4_DEFM_XATTR_USER	0x0004
2215 #define EXT4_DEFM_ACL		0x0008
2216 #define EXT4_DEFM_UID16		0x0010
2217 #define EXT4_DEFM_JMODE		0x0060
2218 #define EXT4_DEFM_JMODE_DATA	0x0020
2219 #define EXT4_DEFM_JMODE_ORDERED	0x0040
2220 #define EXT4_DEFM_JMODE_WBACK	0x0060
2221 #define EXT4_DEFM_NOBARRIER	0x0100
2222 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
2223 #define EXT4_DEFM_DISCARD	0x0400
2224 #define EXT4_DEFM_NODELALLOC	0x0800
2225 
2226 /*
2227  * Default journal batch times
2228  */
2229 #define EXT4_DEF_MIN_BATCH_TIME	0
2230 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
2231 
2232 /*
2233  * Minimum number of groups in a flexgroup before we separate out
2234  * directories into the first block group of a flexgroup
2235  */
2236 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
2237 
2238 /*
2239  * Structure of a directory entry
2240  */
2241 #define EXT4_NAME_LEN 255
2242 /*
2243  * Base length of the ext4 directory entry excluding the name length
2244  */
2245 #define EXT4_BASE_DIR_LEN (sizeof(struct ext4_dir_entry_2) - EXT4_NAME_LEN)
2246 
2247 struct ext4_dir_entry {
2248 	__le32	inode;			/* Inode number */
2249 	__le16	rec_len;		/* Directory entry length */
2250 	__le16	name_len;		/* Name length */
2251 	char	name[EXT4_NAME_LEN];	/* File name */
2252 };
2253 
2254 
2255 /*
2256  * Encrypted Casefolded entries require saving the hash on disk. This structure
2257  * followed ext4_dir_entry_2's name[name_len] at the next 4 byte aligned
2258  * boundary.
2259  */
2260 struct ext4_dir_entry_hash {
2261 	__le32 hash;
2262 	__le32 minor_hash;
2263 };
2264 
2265 /*
2266  * The new version of the directory entry.  Since EXT4 structures are
2267  * stored in intel byte order, and the name_len field could never be
2268  * bigger than 255 chars, it's safe to reclaim the extra byte for the
2269  * file_type field.
2270  */
2271 struct ext4_dir_entry_2 {
2272 	__le32	inode;			/* Inode number */
2273 	__le16	rec_len;		/* Directory entry length */
2274 	__u8	name_len;		/* Name length */
2275 	__u8	file_type;		/* See file type macros EXT4_FT_* below */
2276 	char	name[EXT4_NAME_LEN];	/* File name */
2277 };
2278 
2279 /*
2280  * Access the hashes at the end of ext4_dir_entry_2
2281  */
2282 #define EXT4_DIRENT_HASHES(entry) \
2283 	((struct ext4_dir_entry_hash *) \
2284 		(((void *)(entry)) + \
2285 		((8 + (entry)->name_len + EXT4_DIR_ROUND) & ~EXT4_DIR_ROUND)))
2286 #define EXT4_DIRENT_HASH(entry) le32_to_cpu(EXT4_DIRENT_HASHES(de)->hash)
2287 #define EXT4_DIRENT_MINOR_HASH(entry) \
2288 		le32_to_cpu(EXT4_DIRENT_HASHES(de)->minor_hash)
2289 
2290 static inline bool ext4_hash_in_dirent(const struct inode *inode)
2291 {
2292 	return IS_CASEFOLDED(inode) && IS_ENCRYPTED(inode);
2293 }
2294 
2295 /*
2296  * This is a bogus directory entry at the end of each leaf block that
2297  * records checksums.
2298  */
2299 struct ext4_dir_entry_tail {
2300 	__le32	det_reserved_zero1;	/* Pretend to be unused */
2301 	__le16	det_rec_len;		/* 12 */
2302 	__u8	det_reserved_zero2;	/* Zero name length */
2303 	__u8	det_reserved_ft;	/* 0xDE, fake file type */
2304 	__le32	det_checksum;		/* crc32c(uuid+inum+dirblock) */
2305 };
2306 
2307 #define EXT4_DIRENT_TAIL(block, blocksize) \
2308 	((struct ext4_dir_entry_tail *)(((void *)(block)) + \
2309 					((blocksize) - \
2310 					 sizeof(struct ext4_dir_entry_tail))))
2311 
2312 /*
2313  * Ext4 directory file types.  Only the low 3 bits are used.  The
2314  * other bits are reserved for now.
2315  */
2316 #define EXT4_FT_UNKNOWN		0
2317 #define EXT4_FT_REG_FILE	1
2318 #define EXT4_FT_DIR		2
2319 #define EXT4_FT_CHRDEV		3
2320 #define EXT4_FT_BLKDEV		4
2321 #define EXT4_FT_FIFO		5
2322 #define EXT4_FT_SOCK		6
2323 #define EXT4_FT_SYMLINK		7
2324 
2325 #define EXT4_FT_MAX		8
2326 
2327 #define EXT4_FT_DIR_CSUM	0xDE
2328 
2329 /*
2330  * EXT4_DIR_PAD defines the directory entries boundaries
2331  *
2332  * NOTE: It must be a multiple of 4
2333  */
2334 #define EXT4_DIR_PAD			4
2335 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
2336 #define EXT4_MAX_REC_LEN		((1<<16)-1)
2337 
2338 /*
2339  * The rec_len is dependent on the type of directory. Directories that are
2340  * casefolded and encrypted need to store the hash as well, so we add room for
2341  * ext4_extended_dir_entry_2. For all entries related to '.' or '..' you should
2342  * pass NULL for dir, as those entries do not use the extra fields.
2343  */
2344 static inline unsigned int ext4_dir_rec_len(__u8 name_len,
2345 						const struct inode *dir)
2346 {
2347 	int rec_len = (name_len + 8 + EXT4_DIR_ROUND);
2348 
2349 	if (dir && ext4_hash_in_dirent(dir))
2350 		rec_len += sizeof(struct ext4_dir_entry_hash);
2351 	return (rec_len & ~EXT4_DIR_ROUND);
2352 }
2353 
2354 /*
2355  * If we ever get support for fs block sizes > page_size, we'll need
2356  * to remove the #if statements in the next two functions...
2357  */
2358 static inline unsigned int
2359 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
2360 {
2361 	unsigned len = le16_to_cpu(dlen);
2362 
2363 #if (PAGE_SIZE >= 65536)
2364 	if (len == EXT4_MAX_REC_LEN || len == 0)
2365 		return blocksize;
2366 	return (len & 65532) | ((len & 3) << 16);
2367 #else
2368 	return len;
2369 #endif
2370 }
2371 
2372 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
2373 {
2374 	BUG_ON((len > blocksize) || (blocksize > (1 << 18)) || (len & 3));
2375 #if (PAGE_SIZE >= 65536)
2376 	if (len < 65536)
2377 		return cpu_to_le16(len);
2378 	if (len == blocksize) {
2379 		if (blocksize == 65536)
2380 			return cpu_to_le16(EXT4_MAX_REC_LEN);
2381 		else
2382 			return cpu_to_le16(0);
2383 	}
2384 	return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
2385 #else
2386 	return cpu_to_le16(len);
2387 #endif
2388 }
2389 
2390 /*
2391  * Hash Tree Directory indexing
2392  * (c) Daniel Phillips, 2001
2393  */
2394 
2395 #define is_dx(dir) (ext4_has_feature_dir_index((dir)->i_sb) && \
2396 		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
2397 #define EXT4_DIR_LINK_MAX(dir) unlikely((dir)->i_nlink >= EXT4_LINK_MAX && \
2398 		    !(ext4_has_feature_dir_nlink((dir)->i_sb) && is_dx(dir)))
2399 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
2400 
2401 /* Legal values for the dx_root hash_version field: */
2402 
2403 #define DX_HASH_LEGACY			0
2404 #define DX_HASH_HALF_MD4		1
2405 #define DX_HASH_TEA			2
2406 #define DX_HASH_LEGACY_UNSIGNED		3
2407 #define DX_HASH_HALF_MD4_UNSIGNED	4
2408 #define DX_HASH_TEA_UNSIGNED		5
2409 #define DX_HASH_SIPHASH			6
2410 
2411 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
2412 			      const void *address, unsigned int length)
2413 {
2414 	struct {
2415 		struct shash_desc shash;
2416 		char ctx[4];
2417 	} desc;
2418 
2419 	BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
2420 
2421 	desc.shash.tfm = sbi->s_chksum_driver;
2422 	*(u32 *)desc.ctx = crc;
2423 
2424 	BUG_ON(crypto_shash_update(&desc.shash, address, length));
2425 
2426 	return *(u32 *)desc.ctx;
2427 }
2428 
2429 #ifdef __KERNEL__
2430 
2431 /* hash info structure used by the directory hash */
2432 struct dx_hash_info
2433 {
2434 	u32		hash;
2435 	u32		minor_hash;
2436 	int		hash_version;
2437 	u32		*seed;
2438 };
2439 
2440 
2441 /* 32 and 64 bit signed EOF for dx directories */
2442 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
2443 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
2444 
2445 
2446 /*
2447  * Control parameters used by ext4_htree_next_block
2448  */
2449 #define HASH_NB_ALWAYS		1
2450 
2451 struct ext4_filename {
2452 	const struct qstr *usr_fname;
2453 	struct fscrypt_str disk_name;
2454 	struct dx_hash_info hinfo;
2455 #ifdef CONFIG_FS_ENCRYPTION
2456 	struct fscrypt_str crypto_buf;
2457 #endif
2458 #if IS_ENABLED(CONFIG_UNICODE)
2459 	struct fscrypt_str cf_name;
2460 #endif
2461 };
2462 
2463 #define fname_name(p) ((p)->disk_name.name)
2464 #define fname_usr_name(p) ((p)->usr_fname->name)
2465 #define fname_len(p)  ((p)->disk_name.len)
2466 
2467 /*
2468  * Describe an inode's exact location on disk and in memory
2469  */
2470 struct ext4_iloc
2471 {
2472 	struct buffer_head *bh;
2473 	unsigned long offset;
2474 	ext4_group_t block_group;
2475 };
2476 
2477 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
2478 {
2479 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
2480 }
2481 
2482 static inline bool ext4_is_quota_file(struct inode *inode)
2483 {
2484 	return IS_NOQUOTA(inode) &&
2485 	       !(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL);
2486 }
2487 
2488 /*
2489  * This structure is stuffed into the struct file's private_data field
2490  * for directories.  It is where we put information so that we can do
2491  * readdir operations in hash tree order.
2492  */
2493 struct dir_private_info {
2494 	struct rb_root	root;
2495 	struct rb_node	*curr_node;
2496 	struct fname	*extra_fname;
2497 	loff_t		last_pos;
2498 	__u32		curr_hash;
2499 	__u32		curr_minor_hash;
2500 	__u32		next_hash;
2501 };
2502 
2503 /* calculate the first block number of the group */
2504 static inline ext4_fsblk_t
2505 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
2506 {
2507 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
2508 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
2509 }
2510 
2511 /*
2512  * Special error return code only used by dx_probe() and its callers.
2513  */
2514 #define ERR_BAD_DX_DIR	(-(MAX_ERRNO - 1))
2515 
2516 /* htree levels for ext4 */
2517 #define	EXT4_HTREE_LEVEL_COMPAT	2
2518 #define	EXT4_HTREE_LEVEL	3
2519 
2520 static inline int ext4_dir_htree_level(struct super_block *sb)
2521 {
2522 	return ext4_has_feature_largedir(sb) ?
2523 		EXT4_HTREE_LEVEL : EXT4_HTREE_LEVEL_COMPAT;
2524 }
2525 
2526 /*
2527  * Timeout and state flag for lazy initialization inode thread.
2528  */
2529 #define EXT4_DEF_LI_WAIT_MULT			10
2530 #define EXT4_DEF_LI_MAX_START_DELAY		5
2531 #define EXT4_LAZYINIT_QUIT			0x0001
2532 #define EXT4_LAZYINIT_RUNNING			0x0002
2533 
2534 /*
2535  * Lazy inode table initialization info
2536  */
2537 struct ext4_lazy_init {
2538 	unsigned long		li_state;
2539 	struct list_head	li_request_list;
2540 	struct mutex		li_list_mtx;
2541 };
2542 
2543 enum ext4_li_mode {
2544 	EXT4_LI_MODE_PREFETCH_BBITMAP,
2545 	EXT4_LI_MODE_ITABLE,
2546 };
2547 
2548 struct ext4_li_request {
2549 	struct super_block	*lr_super;
2550 	enum ext4_li_mode	lr_mode;
2551 	ext4_group_t		lr_first_not_zeroed;
2552 	ext4_group_t		lr_next_group;
2553 	struct list_head	lr_request;
2554 	unsigned long		lr_next_sched;
2555 	unsigned long		lr_timeout;
2556 };
2557 
2558 struct ext4_features {
2559 	struct kobject f_kobj;
2560 	struct completion f_kobj_unregister;
2561 };
2562 
2563 /*
2564  * This structure will be used for multiple mount protection. It will be
2565  * written into the block number saved in the s_mmp_block field in the
2566  * superblock. Programs that check MMP should assume that if
2567  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
2568  * to use the filesystem, regardless of how old the timestamp is.
2569  */
2570 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
2571 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
2572 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
2573 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
2574 
2575 struct mmp_struct {
2576 	__le32	mmp_magic;		/* Magic number for MMP */
2577 	__le32	mmp_seq;		/* Sequence no. updated periodically */
2578 
2579 	/*
2580 	 * mmp_time, mmp_nodename & mmp_bdevname are only used for information
2581 	 * purposes and do not affect the correctness of the algorithm
2582 	 */
2583 	__le64	mmp_time;		/* Time last updated */
2584 	char	mmp_nodename[64];	/* Node which last updated MMP block */
2585 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
2586 
2587 	/*
2588 	 * mmp_check_interval is used to verify if the MMP block has been
2589 	 * updated on the block device. The value is updated based on the
2590 	 * maximum time to write the MMP block during an update cycle.
2591 	 */
2592 	__le16	mmp_check_interval;
2593 
2594 	__le16	mmp_pad1;
2595 	__le32	mmp_pad2[226];
2596 	__le32	mmp_checksum;		/* crc32c(uuid+mmp_block) */
2597 };
2598 
2599 /* arguments passed to the mmp thread */
2600 struct mmpd_data {
2601 	struct buffer_head *bh; /* bh from initial read_mmp_block() */
2602 	struct super_block *sb;  /* super block of the fs */
2603 };
2604 
2605 /*
2606  * Check interval multiplier
2607  * The MMP block is written every update interval and initially checked every
2608  * update interval x the multiplier (the value is then adapted based on the
2609  * write latency). The reason is that writes can be delayed under load and we
2610  * don't want readers to incorrectly assume that the filesystem is no longer
2611  * in use.
2612  */
2613 #define EXT4_MMP_CHECK_MULT		2UL
2614 
2615 /*
2616  * Minimum interval for MMP checking in seconds.
2617  */
2618 #define EXT4_MMP_MIN_CHECK_INTERVAL	5UL
2619 
2620 /*
2621  * Maximum interval for MMP checking in seconds.
2622  */
2623 #define EXT4_MMP_MAX_CHECK_INTERVAL	300UL
2624 
2625 /*
2626  * Function prototypes
2627  */
2628 
2629 /*
2630  * Ok, these declarations are also in <linux/kernel.h> but none of the
2631  * ext4 source programs needs to include it so they are duplicated here.
2632  */
2633 # define NORET_TYPE	/**/
2634 # define ATTRIB_NORET	__attribute__((noreturn))
2635 # define NORET_AND	noreturn,
2636 
2637 /* bitmap.c */
2638 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
2639 void ext4_inode_bitmap_csum_set(struct super_block *sb,
2640 				struct ext4_group_desc *gdp,
2641 				struct buffer_head *bh, int sz);
2642 int ext4_inode_bitmap_csum_verify(struct super_block *sb,
2643 				  struct ext4_group_desc *gdp,
2644 				  struct buffer_head *bh, int sz);
2645 void ext4_block_bitmap_csum_set(struct super_block *sb,
2646 				struct ext4_group_desc *gdp,
2647 				struct buffer_head *bh);
2648 int ext4_block_bitmap_csum_verify(struct super_block *sb,
2649 				  struct ext4_group_desc *gdp,
2650 				  struct buffer_head *bh);
2651 
2652 /* balloc.c */
2653 extern void ext4_get_group_no_and_offset(struct super_block *sb,
2654 					 ext4_fsblk_t blocknr,
2655 					 ext4_group_t *blockgrpp,
2656 					 ext4_grpblk_t *offsetp);
2657 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
2658 					  ext4_fsblk_t block);
2659 
2660 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
2661 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
2662 			ext4_group_t group);
2663 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
2664 					 ext4_fsblk_t goal,
2665 					 unsigned int flags,
2666 					 unsigned long *count,
2667 					 int *errp);
2668 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
2669 				    s64 nclusters, unsigned int flags);
2670 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
2671 extern void ext4_check_blocks_bitmap(struct super_block *);
2672 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
2673 						    ext4_group_t block_group,
2674 						    struct buffer_head ** bh);
2675 extern struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2676 						   ext4_group_t group);
2677 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
2678 
2679 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
2680 						ext4_group_t block_group,
2681 						bool ignore_locked);
2682 extern int ext4_wait_block_bitmap(struct super_block *sb,
2683 				  ext4_group_t block_group,
2684 				  struct buffer_head *bh);
2685 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
2686 						  ext4_group_t block_group);
2687 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
2688 					      ext4_group_t block_group,
2689 					      struct ext4_group_desc *gdp);
2690 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
2691 
2692 #if IS_ENABLED(CONFIG_UNICODE)
2693 extern int ext4_fname_setup_ci_filename(struct inode *dir,
2694 					 const struct qstr *iname,
2695 					 struct ext4_filename *fname);
2696 #endif
2697 
2698 /* ext4 encryption related stuff goes here crypto.c */
2699 #ifdef CONFIG_FS_ENCRYPTION
2700 extern const struct fscrypt_operations ext4_cryptops;
2701 
2702 int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
2703 			      int lookup, struct ext4_filename *fname);
2704 
2705 int ext4_fname_prepare_lookup(struct inode *dir, struct dentry *dentry,
2706 			      struct ext4_filename *fname);
2707 
2708 void ext4_fname_free_filename(struct ext4_filename *fname);
2709 
2710 int ext4_ioctl_get_encryption_pwsalt(struct file *filp, void __user *arg);
2711 
2712 #else /* !CONFIG_FS_ENCRYPTION */
2713 static inline int ext4_fname_setup_filename(struct inode *dir,
2714 					    const struct qstr *iname,
2715 					    int lookup,
2716 					    struct ext4_filename *fname)
2717 {
2718 	int err = 0;
2719 	fname->usr_fname = iname;
2720 	fname->disk_name.name = (unsigned char *) iname->name;
2721 	fname->disk_name.len = iname->len;
2722 
2723 #if IS_ENABLED(CONFIG_UNICODE)
2724 	err = ext4_fname_setup_ci_filename(dir, iname, fname);
2725 #endif
2726 
2727 	return err;
2728 }
2729 
2730 static inline int ext4_fname_prepare_lookup(struct inode *dir,
2731 					    struct dentry *dentry,
2732 					    struct ext4_filename *fname)
2733 {
2734 	return ext4_fname_setup_filename(dir, &dentry->d_name, 1, fname);
2735 }
2736 
2737 static inline void ext4_fname_free_filename(struct ext4_filename *fname)
2738 {
2739 #if IS_ENABLED(CONFIG_UNICODE)
2740 	kfree(fname->cf_name.name);
2741 	fname->cf_name.name = NULL;
2742 #endif
2743 }
2744 
2745 static inline int ext4_ioctl_get_encryption_pwsalt(struct file *filp,
2746 						   void __user *arg)
2747 {
2748 	return -EOPNOTSUPP;
2749 }
2750 #endif /* !CONFIG_FS_ENCRYPTION */
2751 
2752 /* dir.c */
2753 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
2754 				  struct file *,
2755 				  struct ext4_dir_entry_2 *,
2756 				  struct buffer_head *, char *, int,
2757 				  unsigned int);
2758 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset) \
2759 	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
2760 				(de), (bh), (buf), (size), (offset)))
2761 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
2762 				__u32 minor_hash,
2763 				struct ext4_dir_entry_2 *dirent,
2764 				struct fscrypt_str *ent_name);
2765 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
2766 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
2767 			     struct buffer_head *bh,
2768 			     void *buf, int buf_size,
2769 			     struct ext4_filename *fname,
2770 			     struct ext4_dir_entry_2 **dest_de);
2771 void ext4_insert_dentry(struct inode *dir, struct inode *inode,
2772 			struct ext4_dir_entry_2 *de,
2773 			int buf_size,
2774 			struct ext4_filename *fname);
2775 static inline void ext4_update_dx_flag(struct inode *inode)
2776 {
2777 	if (!ext4_has_feature_dir_index(inode->i_sb) &&
2778 	    ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) {
2779 		/* ext4_iget() should have caught this... */
2780 		WARN_ON_ONCE(ext4_has_feature_metadata_csum(inode->i_sb));
2781 		ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
2782 	}
2783 }
2784 static const unsigned char ext4_filetype_table[] = {
2785 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
2786 };
2787 
2788 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
2789 {
2790 	if (!ext4_has_feature_filetype(sb) || filetype >= EXT4_FT_MAX)
2791 		return DT_UNKNOWN;
2792 
2793 	return ext4_filetype_table[filetype];
2794 }
2795 extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
2796 			     void *buf, int buf_size);
2797 
2798 /* fsync.c */
2799 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2800 
2801 /* hash.c */
2802 extern int ext4fs_dirhash(const struct inode *dir, const char *name, int len,
2803 			  struct dx_hash_info *hinfo);
2804 
2805 /* ialloc.c */
2806 extern int ext4_mark_inode_used(struct super_block *sb, int ino);
2807 extern struct inode *__ext4_new_inode(struct mnt_idmap *, handle_t *,
2808 				      struct inode *, umode_t,
2809 				      const struct qstr *qstr, __u32 goal,
2810 				      uid_t *owner, __u32 i_flags,
2811 				      int handle_type, unsigned int line_no,
2812 				      int nblocks);
2813 
2814 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner, i_flags)          \
2815 	__ext4_new_inode(&nop_mnt_idmap, (handle), (dir), (mode), (qstr),      \
2816 			 (goal), (owner), i_flags, 0, 0, 0)
2817 #define ext4_new_inode_start_handle(idmap, dir, mode, qstr, goal, owner, \
2818 				    type, nblocks)		    \
2819 	__ext4_new_inode((idmap), NULL, (dir), (mode), (qstr), (goal), (owner), \
2820 			 0, (type), __LINE__, (nblocks))
2821 
2822 
2823 extern void ext4_free_inode(handle_t *, struct inode *);
2824 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2825 extern unsigned long ext4_count_free_inodes(struct super_block *);
2826 extern unsigned long ext4_count_dirs(struct super_block *);
2827 extern void ext4_check_inodes_bitmap(struct super_block *);
2828 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2829 extern int ext4_init_inode_table(struct super_block *sb,
2830 				 ext4_group_t group, int barrier);
2831 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2832 
2833 /* fast_commit.c */
2834 int ext4_fc_info_show(struct seq_file *seq, void *v);
2835 void ext4_fc_init(struct super_block *sb, journal_t *journal);
2836 void ext4_fc_init_inode(struct inode *inode);
2837 void ext4_fc_track_range(handle_t *handle, struct inode *inode, ext4_lblk_t start,
2838 			 ext4_lblk_t end);
2839 void __ext4_fc_track_unlink(handle_t *handle, struct inode *inode,
2840 	struct dentry *dentry);
2841 void __ext4_fc_track_link(handle_t *handle, struct inode *inode,
2842 	struct dentry *dentry);
2843 void ext4_fc_track_unlink(handle_t *handle, struct dentry *dentry);
2844 void ext4_fc_track_link(handle_t *handle, struct dentry *dentry);
2845 void __ext4_fc_track_create(handle_t *handle, struct inode *inode,
2846 			    struct dentry *dentry);
2847 void ext4_fc_track_create(handle_t *handle, struct dentry *dentry);
2848 void ext4_fc_track_inode(handle_t *handle, struct inode *inode);
2849 void ext4_fc_mark_ineligible(struct super_block *sb, int reason, handle_t *handle);
2850 void ext4_fc_start_update(struct inode *inode);
2851 void ext4_fc_stop_update(struct inode *inode);
2852 void ext4_fc_del(struct inode *inode);
2853 bool ext4_fc_replay_check_excluded(struct super_block *sb, ext4_fsblk_t block);
2854 void ext4_fc_replay_cleanup(struct super_block *sb);
2855 int ext4_fc_commit(journal_t *journal, tid_t commit_tid);
2856 int __init ext4_fc_init_dentry_cache(void);
2857 void ext4_fc_destroy_dentry_cache(void);
2858 int ext4_fc_record_regions(struct super_block *sb, int ino,
2859 			   ext4_lblk_t lblk, ext4_fsblk_t pblk,
2860 			   int len, int replay);
2861 
2862 /* mballoc.c */
2863 extern const struct seq_operations ext4_mb_seq_groups_ops;
2864 extern const struct seq_operations ext4_mb_seq_structs_summary_ops;
2865 extern int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset);
2866 extern int ext4_mb_init(struct super_block *);
2867 extern int ext4_mb_release(struct super_block *);
2868 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2869 				struct ext4_allocation_request *, int *);
2870 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2871 extern void ext4_discard_preallocations(struct inode *, unsigned int);
2872 extern int __init ext4_init_mballoc(void);
2873 extern void ext4_exit_mballoc(void);
2874 extern ext4_group_t ext4_mb_prefetch(struct super_block *sb,
2875 				     ext4_group_t group,
2876 				     unsigned int nr, int *cnt);
2877 extern void ext4_mb_prefetch_fini(struct super_block *sb, ext4_group_t group,
2878 				  unsigned int nr);
2879 
2880 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2881 			     struct buffer_head *bh, ext4_fsblk_t block,
2882 			     unsigned long count, int flags);
2883 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2884 				   ext4_group_t ngroups);
2885 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2886 		ext4_group_t i, struct ext4_group_desc *desc);
2887 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2888 				ext4_fsblk_t block, unsigned long count);
2889 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2890 extern void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid);
2891 extern void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
2892 		       int len, int state);
2893 
2894 /* inode.c */
2895 void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw,
2896 			 struct ext4_inode_info *ei);
2897 int ext4_inode_is_fast_symlink(struct inode *inode);
2898 struct buffer_head *ext4_getblk(handle_t *, struct inode *, ext4_lblk_t, int);
2899 struct buffer_head *ext4_bread(handle_t *, struct inode *, ext4_lblk_t, int);
2900 int ext4_bread_batch(struct inode *inode, ext4_lblk_t block, int bh_count,
2901 		     bool wait, struct buffer_head **bhs);
2902 int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
2903 			     struct buffer_head *bh_result, int create);
2904 int ext4_get_block(struct inode *inode, sector_t iblock,
2905 		   struct buffer_head *bh_result, int create);
2906 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2907 			   struct buffer_head *bh, int create);
2908 int ext4_walk_page_buffers(handle_t *handle,
2909 			   struct inode *inode,
2910 			   struct buffer_head *head,
2911 			   unsigned from,
2912 			   unsigned to,
2913 			   int *partial,
2914 			   int (*fn)(handle_t *handle, struct inode *inode,
2915 				     struct buffer_head *bh));
2916 int do_journal_get_write_access(handle_t *handle, struct inode *inode,
2917 				struct buffer_head *bh);
2918 #define FALL_BACK_TO_NONDELALLOC 1
2919 #define CONVERT_INLINE_DATA	 2
2920 
2921 typedef enum {
2922 	EXT4_IGET_NORMAL =	0,
2923 	EXT4_IGET_SPECIAL =	0x0001, /* OK to iget a system inode */
2924 	EXT4_IGET_HANDLE = 	0x0002,	/* Inode # is from a handle */
2925 	EXT4_IGET_BAD =		0x0004, /* Allow to iget a bad inode */
2926 	EXT4_IGET_EA_INODE =	0x0008	/* Inode should contain an EA value */
2927 } ext4_iget_flags;
2928 
2929 extern struct inode *__ext4_iget(struct super_block *sb, unsigned long ino,
2930 				 ext4_iget_flags flags, const char *function,
2931 				 unsigned int line);
2932 
2933 #define ext4_iget(sb, ino, flags) \
2934 	__ext4_iget((sb), (ino), (flags), __func__, __LINE__)
2935 
2936 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2937 extern int  ext4_setattr(struct mnt_idmap *, struct dentry *,
2938 			 struct iattr *);
2939 extern u32  ext4_dio_alignment(struct inode *inode);
2940 extern int  ext4_getattr(struct mnt_idmap *, const struct path *,
2941 			 struct kstat *, u32, unsigned int);
2942 extern void ext4_evict_inode(struct inode *);
2943 extern void ext4_clear_inode(struct inode *);
2944 extern int  ext4_file_getattr(struct mnt_idmap *, const struct path *,
2945 			      struct kstat *, u32, unsigned int);
2946 extern int  ext4_sync_inode(handle_t *, struct inode *);
2947 extern void ext4_dirty_inode(struct inode *, int);
2948 extern int ext4_change_inode_journal_flag(struct inode *, int);
2949 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2950 extern int ext4_get_fc_inode_loc(struct super_block *sb, unsigned long ino,
2951 			  struct ext4_iloc *iloc);
2952 extern int ext4_inode_attach_jinode(struct inode *inode);
2953 extern int ext4_can_truncate(struct inode *inode);
2954 extern int ext4_truncate(struct inode *);
2955 extern int ext4_break_layouts(struct inode *);
2956 extern int ext4_punch_hole(struct file *file, loff_t offset, loff_t length);
2957 extern void ext4_set_inode_flags(struct inode *, bool init);
2958 extern int ext4_alloc_da_blocks(struct inode *inode);
2959 extern void ext4_set_aops(struct inode *inode);
2960 extern int ext4_writepage_trans_blocks(struct inode *);
2961 extern int ext4_normal_submit_inode_data_buffers(struct jbd2_inode *jinode);
2962 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2963 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
2964 			     loff_t lstart, loff_t lend);
2965 extern vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf);
2966 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2967 extern int ext4_get_projid(struct inode *inode, kprojid_t *projid);
2968 extern void ext4_da_release_space(struct inode *inode, int to_free);
2969 extern void ext4_da_update_reserve_space(struct inode *inode,
2970 					int used, int quota_claim);
2971 extern int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk,
2972 			      ext4_fsblk_t pblk, ext4_lblk_t len);
2973 
2974 /* indirect.c */
2975 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2976 				struct ext4_map_blocks *map, int flags);
2977 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2978 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2979 extern int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
2980 				 ext4_lblk_t start, ext4_lblk_t end);
2981 
2982 /* ioctl.c */
2983 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2984 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2985 int ext4_fileattr_set(struct mnt_idmap *idmap,
2986 		      struct dentry *dentry, struct fileattr *fa);
2987 int ext4_fileattr_get(struct dentry *dentry, struct fileattr *fa);
2988 extern void ext4_reset_inode_seed(struct inode *inode);
2989 int ext4_update_overhead(struct super_block *sb, bool force);
2990 
2991 /* migrate.c */
2992 extern int ext4_ext_migrate(struct inode *);
2993 extern int ext4_ind_migrate(struct inode *inode);
2994 
2995 /* namei.c */
2996 extern int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2997 			     struct inode *inode);
2998 extern int ext4_dirblock_csum_verify(struct inode *inode,
2999 				     struct buffer_head *bh);
3000 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
3001 				__u32 start_minor_hash, __u32 *next_hash);
3002 extern int ext4_search_dir(struct buffer_head *bh,
3003 			   char *search_buf,
3004 			   int buf_size,
3005 			   struct inode *dir,
3006 			   struct ext4_filename *fname,
3007 			   unsigned int offset,
3008 			   struct ext4_dir_entry_2 **res_dir);
3009 extern int ext4_generic_delete_entry(struct inode *dir,
3010 				     struct ext4_dir_entry_2 *de_del,
3011 				     struct buffer_head *bh,
3012 				     void *entry_buf,
3013 				     int buf_size,
3014 				     int csum_size);
3015 extern bool ext4_empty_dir(struct inode *inode);
3016 
3017 /* resize.c */
3018 extern void ext4_kvfree_array_rcu(void *to_free);
3019 extern int ext4_group_add(struct super_block *sb,
3020 				struct ext4_new_group_data *input);
3021 extern int ext4_group_extend(struct super_block *sb,
3022 				struct ext4_super_block *es,
3023 				ext4_fsblk_t n_blocks_count);
3024 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
3025 extern unsigned int ext4_list_backups(struct super_block *sb,
3026 				      unsigned int *three, unsigned int *five,
3027 				      unsigned int *seven);
3028 
3029 /* super.c */
3030 extern struct buffer_head *ext4_sb_bread(struct super_block *sb,
3031 					 sector_t block, blk_opf_t op_flags);
3032 extern struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
3033 						   sector_t block);
3034 extern void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
3035 				bh_end_io_t *end_io);
3036 extern int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
3037 			bh_end_io_t *end_io);
3038 extern int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait);
3039 extern void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block);
3040 extern int ext4_seq_options_show(struct seq_file *seq, void *offset);
3041 extern int ext4_calculate_overhead(struct super_block *sb);
3042 extern __le32 ext4_superblock_csum(struct super_block *sb,
3043 				   struct ext4_super_block *es);
3044 extern void ext4_superblock_csum_set(struct super_block *sb);
3045 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
3046 				    ext4_group_t ngroup);
3047 extern const char *ext4_decode_error(struct super_block *sb, int errno,
3048 				     char nbuf[16]);
3049 extern void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
3050 					     ext4_group_t block_group,
3051 					     unsigned int flags);
3052 
3053 extern __printf(7, 8)
3054 void __ext4_error(struct super_block *, const char *, unsigned int, bool,
3055 		  int, __u64, const char *, ...);
3056 extern __printf(6, 7)
3057 void __ext4_error_inode(struct inode *, const char *, unsigned int,
3058 			ext4_fsblk_t, int, const char *, ...);
3059 extern __printf(5, 6)
3060 void __ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
3061 		     const char *, ...);
3062 extern void __ext4_std_error(struct super_block *, const char *,
3063 			     unsigned int, int);
3064 extern __printf(4, 5)
3065 void __ext4_warning(struct super_block *, const char *, unsigned int,
3066 		    const char *, ...);
3067 extern __printf(4, 5)
3068 void __ext4_warning_inode(const struct inode *inode, const char *function,
3069 			  unsigned int line, const char *fmt, ...);
3070 extern __printf(3, 4)
3071 void __ext4_msg(struct super_block *, const char *, const char *, ...);
3072 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
3073 			   const char *, unsigned int, const char *);
3074 extern __printf(7, 8)
3075 void __ext4_grp_locked_error(const char *, unsigned int,
3076 			     struct super_block *, ext4_group_t,
3077 			     unsigned long, ext4_fsblk_t,
3078 			     const char *, ...);
3079 
3080 #define EXT4_ERROR_INODE(inode, fmt, a...) \
3081 	ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
3082 
3083 #define EXT4_ERROR_INODE_ERR(inode, err, fmt, a...)			\
3084 	__ext4_error_inode((inode), __func__, __LINE__, 0, (err), (fmt), ## a)
3085 
3086 #define ext4_error_inode_block(inode, block, err, fmt, a...)		\
3087 	__ext4_error_inode((inode), __func__, __LINE__, (block), (err),	\
3088 			   (fmt), ## a)
3089 
3090 #define EXT4_ERROR_FILE(file, block, fmt, a...)				\
3091 	ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
3092 
3093 #define ext4_abort(sb, err, fmt, a...)					\
3094 	__ext4_error((sb), __func__, __LINE__, true, (err), 0, (fmt), ## a)
3095 
3096 #ifdef CONFIG_PRINTK
3097 
3098 #define ext4_error_inode(inode, func, line, block, fmt, ...)		\
3099 	__ext4_error_inode(inode, func, line, block, 0, fmt, ##__VA_ARGS__)
3100 #define ext4_error_inode_err(inode, func, line, block, err, fmt, ...)	\
3101 	__ext4_error_inode((inode), (func), (line), (block), 		\
3102 			   (err), (fmt), ##__VA_ARGS__)
3103 #define ext4_error_file(file, func, line, block, fmt, ...)		\
3104 	__ext4_error_file(file, func, line, block, fmt, ##__VA_ARGS__)
3105 #define ext4_error(sb, fmt, ...)					\
3106 	__ext4_error((sb), __func__, __LINE__, false, 0, 0, (fmt),	\
3107 		##__VA_ARGS__)
3108 #define ext4_error_err(sb, err, fmt, ...)				\
3109 	__ext4_error((sb), __func__, __LINE__, false, (err), 0, (fmt),	\
3110 		##__VA_ARGS__)
3111 #define ext4_warning(sb, fmt, ...)					\
3112 	__ext4_warning(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
3113 #define ext4_warning_inode(inode, fmt, ...)				\
3114 	__ext4_warning_inode(inode, __func__, __LINE__, fmt, ##__VA_ARGS__)
3115 #define ext4_msg(sb, level, fmt, ...)				\
3116 	__ext4_msg(sb, level, fmt, ##__VA_ARGS__)
3117 #define dump_mmp_msg(sb, mmp, msg)					\
3118 	__dump_mmp_msg(sb, mmp, __func__, __LINE__, msg)
3119 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)		\
3120 	__ext4_grp_locked_error(__func__, __LINE__, sb, grp, ino, block, \
3121 				fmt, ##__VA_ARGS__)
3122 
3123 #else
3124 
3125 #define ext4_error_inode(inode, func, line, block, fmt, ...)		\
3126 do {									\
3127 	no_printk(fmt, ##__VA_ARGS__);					\
3128 	__ext4_error_inode(inode, "", 0, block, 0, " ");		\
3129 } while (0)
3130 #define ext4_error_inode_err(inode, func, line, block, err, fmt, ...)	\
3131 do {									\
3132 	no_printk(fmt, ##__VA_ARGS__);					\
3133 	__ext4_error_inode(inode, "", 0, block, err, " ");		\
3134 } while (0)
3135 #define ext4_error_file(file, func, line, block, fmt, ...)		\
3136 do {									\
3137 	no_printk(fmt, ##__VA_ARGS__);					\
3138 	__ext4_error_file(file, "", 0, block, " ");			\
3139 } while (0)
3140 #define ext4_error(sb, fmt, ...)					\
3141 do {									\
3142 	no_printk(fmt, ##__VA_ARGS__);					\
3143 	__ext4_error(sb, "", 0, false, 0, 0, " ");			\
3144 } while (0)
3145 #define ext4_error_err(sb, err, fmt, ...)				\
3146 do {									\
3147 	no_printk(fmt, ##__VA_ARGS__);					\
3148 	__ext4_error(sb, "", 0, false, err, 0, " ");			\
3149 } while (0)
3150 #define ext4_warning(sb, fmt, ...)					\
3151 do {									\
3152 	no_printk(fmt, ##__VA_ARGS__);					\
3153 	__ext4_warning(sb, "", 0, " ");					\
3154 } while (0)
3155 #define ext4_warning_inode(inode, fmt, ...)				\
3156 do {									\
3157 	no_printk(fmt, ##__VA_ARGS__);					\
3158 	__ext4_warning_inode(inode, "", 0, " ");			\
3159 } while (0)
3160 #define ext4_msg(sb, level, fmt, ...)					\
3161 do {									\
3162 	no_printk(fmt, ##__VA_ARGS__);					\
3163 	__ext4_msg(sb, "", " ");					\
3164 } while (0)
3165 #define dump_mmp_msg(sb, mmp, msg)					\
3166 	__dump_mmp_msg(sb, mmp, "", 0, "")
3167 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)		\
3168 do {									\
3169 	no_printk(fmt, ##__VA_ARGS__);				\
3170 	__ext4_grp_locked_error("", 0, sb, grp, ino, block, " ");	\
3171 } while (0)
3172 
3173 #endif
3174 
3175 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
3176 				      struct ext4_group_desc *bg);
3177 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
3178 				      struct ext4_group_desc *bg);
3179 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
3180 				     struct ext4_group_desc *bg);
3181 extern __u32 ext4_free_group_clusters(struct super_block *sb,
3182 				      struct ext4_group_desc *bg);
3183 extern __u32 ext4_free_inodes_count(struct super_block *sb,
3184 				 struct ext4_group_desc *bg);
3185 extern __u32 ext4_used_dirs_count(struct super_block *sb,
3186 				struct ext4_group_desc *bg);
3187 extern __u32 ext4_itable_unused_count(struct super_block *sb,
3188 				   struct ext4_group_desc *bg);
3189 extern void ext4_block_bitmap_set(struct super_block *sb,
3190 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
3191 extern void ext4_inode_bitmap_set(struct super_block *sb,
3192 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
3193 extern void ext4_inode_table_set(struct super_block *sb,
3194 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
3195 extern void ext4_free_group_clusters_set(struct super_block *sb,
3196 					 struct ext4_group_desc *bg,
3197 					 __u32 count);
3198 extern void ext4_free_inodes_set(struct super_block *sb,
3199 				struct ext4_group_desc *bg, __u32 count);
3200 extern void ext4_used_dirs_set(struct super_block *sb,
3201 				struct ext4_group_desc *bg, __u32 count);
3202 extern void ext4_itable_unused_set(struct super_block *sb,
3203 				   struct ext4_group_desc *bg, __u32 count);
3204 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
3205 				       struct ext4_group_desc *gdp);
3206 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
3207 				     struct ext4_group_desc *gdp);
3208 extern int ext4_register_li_request(struct super_block *sb,
3209 				    ext4_group_t first_not_zeroed);
3210 
3211 static inline int ext4_has_metadata_csum(struct super_block *sb)
3212 {
3213 	WARN_ON_ONCE(ext4_has_feature_metadata_csum(sb) &&
3214 		     !EXT4_SB(sb)->s_chksum_driver);
3215 
3216 	return ext4_has_feature_metadata_csum(sb) &&
3217 	       (EXT4_SB(sb)->s_chksum_driver != NULL);
3218 }
3219 
3220 static inline int ext4_has_group_desc_csum(struct super_block *sb)
3221 {
3222 	return ext4_has_feature_gdt_csum(sb) || ext4_has_metadata_csum(sb);
3223 }
3224 
3225 #define ext4_read_incompat_64bit_val(es, name) \
3226 	(((es)->s_feature_incompat & cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT) \
3227 		? (ext4_fsblk_t)le32_to_cpu(es->name##_hi) << 32 : 0) | \
3228 		le32_to_cpu(es->name##_lo))
3229 
3230 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
3231 {
3232 	return ext4_read_incompat_64bit_val(es, s_blocks_count);
3233 }
3234 
3235 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
3236 {
3237 	return ext4_read_incompat_64bit_val(es, s_r_blocks_count);
3238 }
3239 
3240 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
3241 {
3242 	return ext4_read_incompat_64bit_val(es, s_free_blocks_count);
3243 }
3244 
3245 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
3246 					 ext4_fsblk_t blk)
3247 {
3248 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
3249 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
3250 }
3251 
3252 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
3253 					      ext4_fsblk_t blk)
3254 {
3255 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
3256 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
3257 }
3258 
3259 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
3260 					   ext4_fsblk_t blk)
3261 {
3262 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
3263 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
3264 }
3265 
3266 static inline loff_t ext4_isize(struct super_block *sb,
3267 				struct ext4_inode *raw_inode)
3268 {
3269 	if (ext4_has_feature_largedir(sb) ||
3270 	    S_ISREG(le16_to_cpu(raw_inode->i_mode)))
3271 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
3272 			le32_to_cpu(raw_inode->i_size_lo);
3273 
3274 	return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
3275 }
3276 
3277 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
3278 {
3279 	raw_inode->i_size_lo = cpu_to_le32(i_size);
3280 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
3281 }
3282 
3283 /*
3284  * Reading s_groups_count requires using smp_rmb() afterwards.  See
3285  * the locking protocol documented in the comments of ext4_group_add()
3286  * in resize.c
3287  */
3288 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
3289 {
3290 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
3291 
3292 	smp_rmb();
3293 	return ngroups;
3294 }
3295 
3296 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
3297 					     ext4_group_t block_group)
3298 {
3299 	return block_group >> sbi->s_log_groups_per_flex;
3300 }
3301 
3302 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
3303 {
3304 	return 1 << sbi->s_log_groups_per_flex;
3305 }
3306 
3307 #define ext4_std_error(sb, errno)				\
3308 do {								\
3309 	if ((errno))						\
3310 		__ext4_std_error((sb), __func__, __LINE__, (errno));	\
3311 } while (0)
3312 
3313 #ifdef CONFIG_SMP
3314 /* Each CPU can accumulate percpu_counter_batch clusters in their local
3315  * counters. So we need to make sure we have free clusters more
3316  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
3317  */
3318 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
3319 #else
3320 #define EXT4_FREECLUSTERS_WATERMARK 0
3321 #endif
3322 
3323 /* Update i_disksize. Requires i_rwsem to avoid races with truncate */
3324 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
3325 {
3326 	WARN_ON_ONCE(S_ISREG(inode->i_mode) &&
3327 		     !inode_is_locked(inode));
3328 	down_write(&EXT4_I(inode)->i_data_sem);
3329 	if (newsize > EXT4_I(inode)->i_disksize)
3330 		WRITE_ONCE(EXT4_I(inode)->i_disksize, newsize);
3331 	up_write(&EXT4_I(inode)->i_data_sem);
3332 }
3333 
3334 /* Update i_size, i_disksize. Requires i_rwsem to avoid races with truncate */
3335 static inline int ext4_update_inode_size(struct inode *inode, loff_t newsize)
3336 {
3337 	int changed = 0;
3338 
3339 	if (newsize > inode->i_size) {
3340 		i_size_write(inode, newsize);
3341 		changed = 1;
3342 	}
3343 	if (newsize > EXT4_I(inode)->i_disksize) {
3344 		ext4_update_i_disksize(inode, newsize);
3345 		changed |= 2;
3346 	}
3347 	return changed;
3348 }
3349 
3350 int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset,
3351 				      loff_t len);
3352 
3353 struct ext4_group_info {
3354 	unsigned long   bb_state;
3355 #ifdef AGGRESSIVE_CHECK
3356 	unsigned long	bb_check_counter;
3357 #endif
3358 	struct rb_root  bb_free_root;
3359 	ext4_grpblk_t	bb_first_free;	/* first free block */
3360 	ext4_grpblk_t	bb_free;	/* total free blocks */
3361 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
3362 	int		bb_avg_fragment_size_order;	/* order of average
3363 							   fragment in BG */
3364 	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
3365 	ext4_group_t	bb_group;	/* Group number */
3366 	struct          list_head bb_prealloc_list;
3367 #ifdef DOUBLE_CHECK
3368 	void            *bb_bitmap;
3369 #endif
3370 	struct rw_semaphore alloc_sem;
3371 	struct list_head bb_avg_fragment_size_node;
3372 	struct list_head bb_largest_free_order_node;
3373 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
3374 					 * regions, index is order.
3375 					 * bb_counters[3] = 5 means
3376 					 * 5 free 8-block regions. */
3377 };
3378 
3379 #define EXT4_GROUP_INFO_NEED_INIT_BIT		0
3380 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT		1
3381 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT	2
3382 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT	3
3383 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT		\
3384 	(1 << EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT)
3385 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT		\
3386 	(1 << EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT)
3387 #define EXT4_GROUP_INFO_BBITMAP_READ_BIT	4
3388 
3389 #define EXT4_MB_GRP_NEED_INIT(grp)	\
3390 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
3391 #define EXT4_MB_GRP_BBITMAP_CORRUPT(grp)	\
3392 	(test_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
3393 #define EXT4_MB_GRP_IBITMAP_CORRUPT(grp)	\
3394 	(test_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
3395 
3396 #define EXT4_MB_GRP_WAS_TRIMMED(grp)	\
3397 	(test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
3398 #define EXT4_MB_GRP_SET_TRIMMED(grp)	\
3399 	(set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
3400 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)	\
3401 	(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
3402 #define EXT4_MB_GRP_TEST_AND_SET_READ(grp)	\
3403 	(test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_READ_BIT, &((grp)->bb_state)))
3404 
3405 #define EXT4_MAX_CONTENTION		8
3406 #define EXT4_CONTENTION_THRESHOLD	2
3407 
3408 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
3409 					      ext4_group_t group)
3410 {
3411 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
3412 }
3413 
3414 /*
3415  * Returns true if the filesystem is busy enough that attempts to
3416  * access the block group locks has run into contention.
3417  */
3418 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
3419 {
3420 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
3421 }
3422 
3423 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
3424 {
3425 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
3426 	if (spin_trylock(lock))
3427 		/*
3428 		 * We're able to grab the lock right away, so drop the
3429 		 * lock contention counter.
3430 		 */
3431 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
3432 	else {
3433 		/*
3434 		 * The lock is busy, so bump the contention counter,
3435 		 * and then wait on the spin lock.
3436 		 */
3437 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
3438 				  EXT4_MAX_CONTENTION);
3439 		spin_lock(lock);
3440 	}
3441 }
3442 
3443 static inline void ext4_unlock_group(struct super_block *sb,
3444 					ext4_group_t group)
3445 {
3446 	spin_unlock(ext4_group_lock_ptr(sb, group));
3447 }
3448 
3449 #ifdef CONFIG_QUOTA
3450 static inline bool ext4_quota_capable(struct super_block *sb)
3451 {
3452 	return (test_opt(sb, QUOTA) || ext4_has_feature_quota(sb));
3453 }
3454 
3455 static inline bool ext4_is_quota_journalled(struct super_block *sb)
3456 {
3457 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3458 
3459 	return (ext4_has_feature_quota(sb) ||
3460 		sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]);
3461 }
3462 int ext4_enable_quotas(struct super_block *sb);
3463 #endif
3464 
3465 /*
3466  * Block validity checking
3467  */
3468 #define ext4_check_indirect_blockref(inode, bh)				\
3469 	ext4_check_blockref(__func__, __LINE__, inode,			\
3470 			    (__le32 *)(bh)->b_data,			\
3471 			    EXT4_ADDR_PER_BLOCK((inode)->i_sb))
3472 
3473 #define ext4_ind_check_inode(inode)					\
3474 	ext4_check_blockref(__func__, __LINE__, inode,			\
3475 			    EXT4_I(inode)->i_data,			\
3476 			    EXT4_NDIR_BLOCKS)
3477 
3478 /*
3479  * Inodes and files operations
3480  */
3481 
3482 /* dir.c */
3483 extern const struct file_operations ext4_dir_operations;
3484 
3485 /* file.c */
3486 extern const struct inode_operations ext4_file_inode_operations;
3487 extern const struct file_operations ext4_file_operations;
3488 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
3489 
3490 /* inline.c */
3491 extern int ext4_get_max_inline_size(struct inode *inode);
3492 extern int ext4_find_inline_data_nolock(struct inode *inode);
3493 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
3494 				 unsigned int len);
3495 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
3496 
3497 int ext4_readpage_inline(struct inode *inode, struct folio *folio);
3498 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
3499 					 struct inode *inode,
3500 					 loff_t pos, unsigned len,
3501 					 struct page **pagep);
3502 int ext4_write_inline_data_end(struct inode *inode, loff_t pos, unsigned len,
3503 			       unsigned copied, struct folio *folio);
3504 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
3505 					   struct inode *inode,
3506 					   loff_t pos, unsigned len,
3507 					   struct page **pagep,
3508 					   void **fsdata);
3509 extern int ext4_try_add_inline_entry(handle_t *handle,
3510 				     struct ext4_filename *fname,
3511 				     struct inode *dir, struct inode *inode);
3512 extern int ext4_try_create_inline_dir(handle_t *handle,
3513 				      struct inode *parent,
3514 				      struct inode *inode);
3515 extern int ext4_read_inline_dir(struct file *filp,
3516 				struct dir_context *ctx,
3517 				int *has_inline_data);
3518 extern int ext4_inlinedir_to_tree(struct file *dir_file,
3519 				  struct inode *dir, ext4_lblk_t block,
3520 				  struct dx_hash_info *hinfo,
3521 				  __u32 start_hash, __u32 start_minor_hash,
3522 				  int *has_inline_data);
3523 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
3524 					struct ext4_filename *fname,
3525 					struct ext4_dir_entry_2 **res_dir,
3526 					int *has_inline_data);
3527 extern int ext4_delete_inline_entry(handle_t *handle,
3528 				    struct inode *dir,
3529 				    struct ext4_dir_entry_2 *de_del,
3530 				    struct buffer_head *bh,
3531 				    int *has_inline_data);
3532 extern bool empty_inline_dir(struct inode *dir, int *has_inline_data);
3533 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
3534 					struct ext4_dir_entry_2 **parent_de,
3535 					int *retval);
3536 extern void *ext4_read_inline_link(struct inode *inode);
3537 
3538 struct iomap;
3539 extern int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap);
3540 
3541 extern int ext4_inline_data_truncate(struct inode *inode, int *has_inline);
3542 
3543 extern int ext4_convert_inline_data(struct inode *inode);
3544 
3545 static inline int ext4_has_inline_data(struct inode *inode)
3546 {
3547 	return ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA) &&
3548 	       EXT4_I(inode)->i_inline_off;
3549 }
3550 
3551 /* namei.c */
3552 extern const struct inode_operations ext4_dir_inode_operations;
3553 extern const struct inode_operations ext4_special_inode_operations;
3554 extern struct dentry *ext4_get_parent(struct dentry *child);
3555 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
3556 				 struct ext4_dir_entry_2 *de,
3557 				 int blocksize, int csum_size,
3558 				 unsigned int parent_ino, int dotdot_real_len);
3559 extern void ext4_initialize_dirent_tail(struct buffer_head *bh,
3560 					unsigned int blocksize);
3561 extern int ext4_handle_dirty_dirblock(handle_t *handle, struct inode *inode,
3562 				      struct buffer_head *bh);
3563 extern int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
3564 			 struct inode *inode, struct dentry *dentry);
3565 extern int __ext4_link(struct inode *dir, struct inode *inode,
3566 		       struct dentry *dentry);
3567 
3568 #define S_SHIFT 12
3569 static const unsigned char ext4_type_by_mode[(S_IFMT >> S_SHIFT) + 1] = {
3570 	[S_IFREG >> S_SHIFT]	= EXT4_FT_REG_FILE,
3571 	[S_IFDIR >> S_SHIFT]	= EXT4_FT_DIR,
3572 	[S_IFCHR >> S_SHIFT]	= EXT4_FT_CHRDEV,
3573 	[S_IFBLK >> S_SHIFT]	= EXT4_FT_BLKDEV,
3574 	[S_IFIFO >> S_SHIFT]	= EXT4_FT_FIFO,
3575 	[S_IFSOCK >> S_SHIFT]	= EXT4_FT_SOCK,
3576 	[S_IFLNK >> S_SHIFT]	= EXT4_FT_SYMLINK,
3577 };
3578 
3579 static inline void ext4_set_de_type(struct super_block *sb,
3580 				struct ext4_dir_entry_2 *de,
3581 				umode_t mode) {
3582 	if (ext4_has_feature_filetype(sb))
3583 		de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
3584 }
3585 
3586 /* readpages.c */
3587 extern int ext4_mpage_readpages(struct inode *inode,
3588 		struct readahead_control *rac, struct folio *folio);
3589 extern int __init ext4_init_post_read_processing(void);
3590 extern void ext4_exit_post_read_processing(void);
3591 
3592 /* symlink.c */
3593 extern const struct inode_operations ext4_encrypted_symlink_inode_operations;
3594 extern const struct inode_operations ext4_symlink_inode_operations;
3595 extern const struct inode_operations ext4_fast_symlink_inode_operations;
3596 
3597 /* sysfs.c */
3598 extern void ext4_notify_error_sysfs(struct ext4_sb_info *sbi);
3599 extern int ext4_register_sysfs(struct super_block *sb);
3600 extern void ext4_unregister_sysfs(struct super_block *sb);
3601 extern int __init ext4_init_sysfs(void);
3602 extern void ext4_exit_sysfs(void);
3603 
3604 /* block_validity */
3605 extern void ext4_release_system_zone(struct super_block *sb);
3606 extern int ext4_setup_system_zone(struct super_block *sb);
3607 extern int __init ext4_init_system_zone(void);
3608 extern void ext4_exit_system_zone(void);
3609 extern int ext4_inode_block_valid(struct inode *inode,
3610 				  ext4_fsblk_t start_blk,
3611 				  unsigned int count);
3612 extern int ext4_check_blockref(const char *, unsigned int,
3613 			       struct inode *, __le32 *, unsigned int);
3614 extern int ext4_sb_block_valid(struct super_block *sb, struct inode *inode,
3615 				ext4_fsblk_t start_blk, unsigned int count);
3616 
3617 
3618 /* extents.c */
3619 struct ext4_ext_path;
3620 struct ext4_extent;
3621 
3622 /*
3623  * Maximum number of logical blocks in a file; ext4_extent's ee_block is
3624  * __le32.
3625  */
3626 #define EXT_MAX_BLOCKS	0xffffffff
3627 
3628 extern void ext4_ext_tree_init(handle_t *handle, struct inode *inode);
3629 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
3630 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
3631 			       struct ext4_map_blocks *map, int flags);
3632 extern int ext4_ext_truncate(handle_t *, struct inode *);
3633 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
3634 				 ext4_lblk_t end);
3635 extern void ext4_ext_init(struct super_block *);
3636 extern void ext4_ext_release(struct super_block *);
3637 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
3638 			  loff_t len);
3639 extern int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
3640 					  loff_t offset, ssize_t len);
3641 extern int ext4_convert_unwritten_io_end_vec(handle_t *handle,
3642 					     ext4_io_end_t *io_end);
3643 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
3644 			   struct ext4_map_blocks *map, int flags);
3645 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
3646 						   int num,
3647 						   struct ext4_ext_path *path);
3648 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
3649 				  struct ext4_ext_path **,
3650 				  struct ext4_extent *, int);
3651 extern struct ext4_ext_path *ext4_find_extent(struct inode *, ext4_lblk_t,
3652 					      struct ext4_ext_path **,
3653 					      int flags);
3654 extern void ext4_free_ext_path(struct ext4_ext_path *);
3655 extern int ext4_ext_check_inode(struct inode *inode);
3656 extern ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path);
3657 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3658 			__u64 start, __u64 len);
3659 extern int ext4_get_es_cache(struct inode *inode,
3660 			     struct fiemap_extent_info *fieinfo,
3661 			     __u64 start, __u64 len);
3662 extern int ext4_ext_precache(struct inode *inode);
3663 extern int ext4_swap_extents(handle_t *handle, struct inode *inode1,
3664 				struct inode *inode2, ext4_lblk_t lblk1,
3665 			     ext4_lblk_t lblk2,  ext4_lblk_t count,
3666 			     int mark_unwritten,int *err);
3667 extern int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu);
3668 extern int ext4_datasem_ensure_credits(handle_t *handle, struct inode *inode,
3669 				       int check_cred, int restart_cred,
3670 				       int revoke_cred);
3671 extern void ext4_ext_replay_shrink_inode(struct inode *inode, ext4_lblk_t end);
3672 extern int ext4_ext_replay_set_iblocks(struct inode *inode);
3673 extern int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start,
3674 		int len, int unwritten, ext4_fsblk_t pblk);
3675 extern int ext4_ext_clear_bb(struct inode *inode);
3676 
3677 
3678 /* move_extent.c */
3679 extern void ext4_double_down_write_data_sem(struct inode *first,
3680 					    struct inode *second);
3681 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
3682 					  struct inode *donor_inode);
3683 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
3684 			     __u64 start_orig, __u64 start_donor,
3685 			     __u64 len, __u64 *moved_len);
3686 
3687 /* page-io.c */
3688 extern int __init ext4_init_pageio(void);
3689 extern void ext4_exit_pageio(void);
3690 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
3691 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
3692 extern int ext4_put_io_end(ext4_io_end_t *io_end);
3693 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
3694 extern void ext4_io_submit_init(struct ext4_io_submit *io,
3695 				struct writeback_control *wbc);
3696 extern void ext4_end_io_rsv_work(struct work_struct *work);
3697 extern void ext4_io_submit(struct ext4_io_submit *io);
3698 int ext4_bio_write_folio(struct ext4_io_submit *io, struct folio *page,
3699 		size_t len);
3700 extern struct ext4_io_end_vec *ext4_alloc_io_end_vec(ext4_io_end_t *io_end);
3701 extern struct ext4_io_end_vec *ext4_last_io_end_vec(ext4_io_end_t *io_end);
3702 
3703 /* mmp.c */
3704 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
3705 
3706 /* mmp.c */
3707 extern void ext4_stop_mmpd(struct ext4_sb_info *sbi);
3708 
3709 /* verity.c */
3710 extern const struct fsverity_operations ext4_verityops;
3711 
3712 /* orphan.c */
3713 extern int ext4_orphan_add(handle_t *, struct inode *);
3714 extern int ext4_orphan_del(handle_t *, struct inode *);
3715 extern void ext4_orphan_cleanup(struct super_block *sb,
3716 				struct ext4_super_block *es);
3717 extern void ext4_release_orphan_info(struct super_block *sb);
3718 extern int ext4_init_orphan_info(struct super_block *sb);
3719 extern int ext4_orphan_file_empty(struct super_block *sb);
3720 extern void ext4_orphan_file_block_trigger(
3721 				struct jbd2_buffer_trigger_type *triggers,
3722 				struct buffer_head *bh,
3723 				void *data, size_t size);
3724 
3725 /*
3726  * Add new method to test whether block and inode bitmaps are properly
3727  * initialized. With uninit_bg reading the block from disk is not enough
3728  * to mark the bitmap uptodate. We need to also zero-out the bitmap
3729  */
3730 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
3731 
3732 static inline int bitmap_uptodate(struct buffer_head *bh)
3733 {
3734 	return (buffer_uptodate(bh) &&
3735 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
3736 }
3737 static inline void set_bitmap_uptodate(struct buffer_head *bh)
3738 {
3739 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
3740 }
3741 
3742 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
3743 
3744 /* For ioend & aio unwritten conversion wait queues */
3745 #define EXT4_WQ_HASH_SZ		37
3746 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
3747 					    EXT4_WQ_HASH_SZ])
3748 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
3749 
3750 extern int ext4_resize_begin(struct super_block *sb);
3751 extern int ext4_resize_end(struct super_block *sb, bool update_backups);
3752 
3753 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
3754 					      struct ext4_io_end *io_end)
3755 {
3756 	if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
3757 		io_end->flag |= EXT4_IO_END_UNWRITTEN;
3758 		atomic_inc(&EXT4_I(inode)->i_unwritten);
3759 	}
3760 }
3761 
3762 static inline void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end)
3763 {
3764 	struct inode *inode = io_end->inode;
3765 
3766 	if (io_end->flag & EXT4_IO_END_UNWRITTEN) {
3767 		io_end->flag &= ~EXT4_IO_END_UNWRITTEN;
3768 		/* Wake up anyone waiting on unwritten extent conversion */
3769 		if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten))
3770 			wake_up_all(ext4_ioend_wq(inode));
3771 	}
3772 }
3773 
3774 extern const struct iomap_ops ext4_iomap_ops;
3775 extern const struct iomap_ops ext4_iomap_overwrite_ops;
3776 extern const struct iomap_ops ext4_iomap_report_ops;
3777 
3778 static inline int ext4_buffer_uptodate(struct buffer_head *bh)
3779 {
3780 	/*
3781 	 * If the buffer has the write error flag, we have failed
3782 	 * to write out data in the block.  In this  case, we don't
3783 	 * have to read the block because we may read the old data
3784 	 * successfully.
3785 	 */
3786 	if (buffer_write_io_error(bh))
3787 		set_buffer_uptodate(bh);
3788 	return buffer_uptodate(bh);
3789 }
3790 
3791 #endif	/* __KERNEL__ */
3792 
3793 #define EFSBADCRC	EBADMSG		/* Bad CRC detected */
3794 #define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
3795 
3796 #endif	/* _EXT4_H */
3797