xref: /openbmc/linux/fs/ext4/ext4.h (revision 84b102f5)
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/types.h>
21 #include <linux/blkdev.h>
22 #include <linux/magic.h>
23 #include <linux/jbd2.h>
24 #include <linux/quota.h>
25 #include <linux/rwsem.h>
26 #include <linux/rbtree.h>
27 #include <linux/seqlock.h>
28 #include <linux/mutex.h>
29 #include <linux/timer.h>
30 #include <linux/wait.h>
31 #include <linux/sched/signal.h>
32 #include <linux/blockgroup_lock.h>
33 #include <linux/percpu_counter.h>
34 #include <linux/ratelimit.h>
35 #include <crypto/hash.h>
36 #include <linux/falloc.h>
37 #include <linux/percpu-rwsem.h>
38 #include <linux/fiemap.h>
39 #ifdef __KERNEL__
40 #include <linux/compat.h>
41 #endif
42 
43 #include <linux/fscrypt.h>
44 #include <linux/fsverity.h>
45 
46 #include <linux/compiler.h>
47 
48 /*
49  * The fourth extended filesystem constants/structures
50  */
51 
52 /*
53  * with AGGRESSIVE_CHECK allocator runs consistency checks over
54  * structures. these checks slow things down a lot
55  */
56 #define AGGRESSIVE_CHECK__
57 
58 /*
59  * with DOUBLE_CHECK defined mballoc creates persistent in-core
60  * bitmaps, maintains and uses them to check for double allocations
61  */
62 #define DOUBLE_CHECK__
63 
64 /*
65  * Define EXT4FS_DEBUG to produce debug messages
66  */
67 #undef EXT4FS_DEBUG
68 
69 /*
70  * Debug code
71  */
72 #ifdef EXT4FS_DEBUG
73 #define ext4_debug(f, a...)						\
74 	do {								\
75 		printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",	\
76 			__FILE__, __LINE__, __func__);			\
77 		printk(KERN_DEBUG f, ## a);				\
78 	} while (0)
79 #else
80 #define ext4_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
81 #endif
82 
83  /*
84   * Turn on EXT_DEBUG to enable ext4_ext_show_path/leaf/move in extents.c
85   */
86 #define EXT_DEBUG__
87 
88 /*
89  * Dynamic printk for controlled extents debugging.
90  */
91 #ifdef CONFIG_EXT4_DEBUG
92 #define ext_debug(ino, fmt, ...)					\
93 	pr_debug("[%s/%d] EXT4-fs (%s): ino %lu: (%s, %d): %s:" fmt,	\
94 		 current->comm, task_pid_nr(current),			\
95 		 ino->i_sb->s_id, ino->i_ino, __FILE__, __LINE__,	\
96 		 __func__, ##__VA_ARGS__)
97 #else
98 #define ext_debug(ino, fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
99 #endif
100 
101 #define ASSERT(assert)						\
102 do {									\
103 	if (unlikely(!(assert))) {					\
104 		printk(KERN_EMERG					\
105 		       "Assertion failure in %s() at %s:%d: '%s'\n",	\
106 		       __func__, __FILE__, __LINE__, #assert);		\
107 		BUG();							\
108 	}								\
109 } while (0)
110 
111 /* data type for block offset of block group */
112 typedef int ext4_grpblk_t;
113 
114 /* data type for filesystem-wide blocks number */
115 typedef unsigned long long ext4_fsblk_t;
116 
117 /* data type for file logical block number */
118 typedef __u32 ext4_lblk_t;
119 
120 /* data type for block group number */
121 typedef unsigned int ext4_group_t;
122 
123 enum SHIFT_DIRECTION {
124 	SHIFT_LEFT = 0,
125 	SHIFT_RIGHT,
126 };
127 
128 /*
129  * Flags used in mballoc's allocation_context flags field.
130  *
131  * Also used to show what's going on for debugging purposes when the
132  * flag field is exported via the traceport interface
133  */
134 
135 /* prefer goal again. length */
136 #define EXT4_MB_HINT_MERGE		0x0001
137 /* blocks already reserved */
138 #define EXT4_MB_HINT_RESERVED		0x0002
139 /* metadata is being allocated */
140 #define EXT4_MB_HINT_METADATA		0x0004
141 /* first blocks in the file */
142 #define EXT4_MB_HINT_FIRST		0x0008
143 /* search for the best chunk */
144 #define EXT4_MB_HINT_BEST		0x0010
145 /* data is being allocated */
146 #define EXT4_MB_HINT_DATA		0x0020
147 /* don't preallocate (for tails) */
148 #define EXT4_MB_HINT_NOPREALLOC		0x0040
149 /* allocate for locality group */
150 #define EXT4_MB_HINT_GROUP_ALLOC	0x0080
151 /* allocate goal blocks or none */
152 #define EXT4_MB_HINT_GOAL_ONLY		0x0100
153 /* goal is meaningful */
154 #define EXT4_MB_HINT_TRY_GOAL		0x0200
155 /* blocks already pre-reserved by delayed allocation */
156 #define EXT4_MB_DELALLOC_RESERVED	0x0400
157 /* We are doing stream allocation */
158 #define EXT4_MB_STREAM_ALLOC		0x0800
159 /* Use reserved root blocks if needed */
160 #define EXT4_MB_USE_ROOT_BLOCKS		0x1000
161 /* Use blocks from reserved pool */
162 #define EXT4_MB_USE_RESERVED		0x2000
163 /* Do strict check for free blocks while retrying block allocation */
164 #define EXT4_MB_STRICT_CHECK		0x4000
165 
166 struct ext4_allocation_request {
167 	/* target inode for block we're allocating */
168 	struct inode *inode;
169 	/* how many blocks we want to allocate */
170 	unsigned int len;
171 	/* logical block in target inode */
172 	ext4_lblk_t logical;
173 	/* the closest logical allocated block to the left */
174 	ext4_lblk_t lleft;
175 	/* the closest logical allocated block to the right */
176 	ext4_lblk_t lright;
177 	/* phys. target (a hint) */
178 	ext4_fsblk_t goal;
179 	/* phys. block for the closest logical allocated block to the left */
180 	ext4_fsblk_t pleft;
181 	/* phys. block for the closest logical allocated block to the right */
182 	ext4_fsblk_t pright;
183 	/* flags. see above EXT4_MB_HINT_* */
184 	unsigned int flags;
185 };
186 
187 /*
188  * Logical to physical block mapping, used by ext4_map_blocks()
189  *
190  * This structure is used to pass requests into ext4_map_blocks() as
191  * well as to store the information returned by ext4_map_blocks().  It
192  * takes less room on the stack than a struct buffer_head.
193  */
194 #define EXT4_MAP_NEW		BIT(BH_New)
195 #define EXT4_MAP_MAPPED		BIT(BH_Mapped)
196 #define EXT4_MAP_UNWRITTEN	BIT(BH_Unwritten)
197 #define EXT4_MAP_BOUNDARY	BIT(BH_Boundary)
198 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
199 				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY)
200 
201 struct ext4_map_blocks {
202 	ext4_fsblk_t m_pblk;
203 	ext4_lblk_t m_lblk;
204 	unsigned int m_len;
205 	unsigned int m_flags;
206 };
207 
208 /*
209  * Block validity checking, system zone rbtree.
210  */
211 struct ext4_system_blocks {
212 	struct rb_root root;
213 	struct rcu_head rcu;
214 };
215 
216 /*
217  * Flags for ext4_io_end->flags
218  */
219 #define	EXT4_IO_END_UNWRITTEN	0x0001
220 
221 struct ext4_io_end_vec {
222 	struct list_head list;		/* list of io_end_vec */
223 	loff_t offset;			/* offset in the file */
224 	ssize_t size;			/* size of the extent */
225 };
226 
227 /*
228  * For converting unwritten extents on a work queue. 'handle' is used for
229  * buffered writeback.
230  */
231 typedef struct ext4_io_end {
232 	struct list_head	list;		/* per-file finished IO list */
233 	handle_t		*handle;	/* handle reserved for extent
234 						 * conversion */
235 	struct inode		*inode;		/* file being written to */
236 	struct bio		*bio;		/* Linked list of completed
237 						 * bios covering the extent */
238 	unsigned int		flag;		/* unwritten or not */
239 	atomic_t		count;		/* reference counter */
240 	struct list_head	list_vec;	/* list of ext4_io_end_vec */
241 } ext4_io_end_t;
242 
243 struct ext4_io_submit {
244 	struct writeback_control *io_wbc;
245 	struct bio		*io_bio;
246 	ext4_io_end_t		*io_end;
247 	sector_t		io_next_block;
248 };
249 
250 /*
251  * Special inodes numbers
252  */
253 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
254 #define EXT4_ROOT_INO		 2	/* Root inode */
255 #define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
256 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
257 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
258 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
259 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
260 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
261 
262 /* First non-reserved inode for old ext4 filesystems */
263 #define EXT4_GOOD_OLD_FIRST_INO	11
264 
265 /*
266  * Maximal count of links to a file
267  */
268 #define EXT4_LINK_MAX		65000
269 
270 /*
271  * Macro-instructions used to manage several block sizes
272  */
273 #define EXT4_MIN_BLOCK_SIZE		1024
274 #define	EXT4_MAX_BLOCK_SIZE		65536
275 #define EXT4_MIN_BLOCK_LOG_SIZE		10
276 #define EXT4_MAX_BLOCK_LOG_SIZE		16
277 #define EXT4_MAX_CLUSTER_LOG_SIZE	30
278 #ifdef __KERNEL__
279 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
280 #else
281 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
282 #endif
283 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
284 #define EXT4_CLUSTER_SIZE(s)		(EXT4_BLOCK_SIZE(s) << \
285 					 EXT4_SB(s)->s_cluster_bits)
286 #ifdef __KERNEL__
287 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
288 # define EXT4_CLUSTER_BITS(s)		(EXT4_SB(s)->s_cluster_bits)
289 #else
290 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
291 #endif
292 #ifdef __KERNEL__
293 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
294 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
295 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
296 #else
297 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
298 				 EXT4_GOOD_OLD_INODE_SIZE : \
299 				 (s)->s_inode_size)
300 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
301 				 EXT4_GOOD_OLD_FIRST_INO : \
302 				 (s)->s_first_ino)
303 #endif
304 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
305 #define EXT4_MAX_BLOCKS(size, offset, blkbits) \
306 	((EXT4_BLOCK_ALIGN(size + offset, blkbits) >> blkbits) - (offset >> \
307 								  blkbits))
308 
309 /* Translate a block number to a cluster number */
310 #define EXT4_B2C(sbi, blk)	((blk) >> (sbi)->s_cluster_bits)
311 /* Translate a cluster number to a block number */
312 #define EXT4_C2B(sbi, cluster)	((cluster) << (sbi)->s_cluster_bits)
313 /* Translate # of blks to # of clusters */
314 #define EXT4_NUM_B2C(sbi, blks)	(((blks) + (sbi)->s_cluster_ratio - 1) >> \
315 				 (sbi)->s_cluster_bits)
316 /* Mask out the low bits to get the starting block of the cluster */
317 #define EXT4_PBLK_CMASK(s, pblk) ((pblk) &				\
318 				  ~((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
319 #define EXT4_LBLK_CMASK(s, lblk) ((lblk) &				\
320 				  ~((ext4_lblk_t) (s)->s_cluster_ratio - 1))
321 /* Fill in the low bits to get the last block of the cluster */
322 #define EXT4_LBLK_CFILL(sbi, lblk) ((lblk) |				\
323 				    ((ext4_lblk_t) (sbi)->s_cluster_ratio - 1))
324 /* Get the cluster offset */
325 #define EXT4_PBLK_COFF(s, pblk) ((pblk) &				\
326 				 ((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
327 #define EXT4_LBLK_COFF(s, lblk) ((lblk) &				\
328 				 ((ext4_lblk_t) (s)->s_cluster_ratio - 1))
329 
330 /*
331  * Structure of a blocks group descriptor
332  */
333 struct ext4_group_desc
334 {
335 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
336 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
337 	__le32	bg_inode_table_lo;	/* Inodes table block */
338 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
339 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
340 	__le16	bg_used_dirs_count_lo;	/* Directories count */
341 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
342 	__le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
343 	__le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
344 	__le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
345 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
346 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
347 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
348 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
349 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
350 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
351 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
352 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
353 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
354 	__le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
355 	__le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
356 	__le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
357 	__u32   bg_reserved;
358 };
359 
360 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END	\
361 	(offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
362 	 sizeof(__le16))
363 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END	\
364 	(offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
365 	 sizeof(__le16))
366 
367 /*
368  * Structure of a flex block group info
369  */
370 
371 struct flex_groups {
372 	atomic64_t	free_clusters;
373 	atomic_t	free_inodes;
374 	atomic_t	used_dirs;
375 };
376 
377 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
378 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
379 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
380 
381 /*
382  * Macro-instructions used to manage group descriptors
383  */
384 #define EXT4_MIN_DESC_SIZE		32
385 #define EXT4_MIN_DESC_SIZE_64BIT	64
386 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
387 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
388 #ifdef __KERNEL__
389 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
390 # define EXT4_CLUSTERS_PER_GROUP(s)	(EXT4_SB(s)->s_clusters_per_group)
391 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
392 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
393 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
394 #else
395 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
396 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
397 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
398 #endif
399 
400 /*
401  * Constants relative to the data blocks
402  */
403 #define	EXT4_NDIR_BLOCKS		12
404 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
405 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
406 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
407 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
408 
409 /*
410  * Inode flags
411  */
412 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
413 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
414 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
415 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
416 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
417 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
418 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
419 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
420 /* Reserved for compression usage... */
421 #define EXT4_DIRTY_FL			0x00000100
422 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
423 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
424 	/* nb: was previously EXT2_ECOMPR_FL */
425 #define EXT4_ENCRYPT_FL			0x00000800 /* encrypted file */
426 /* End compression flags --- maybe not all used */
427 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
428 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
429 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
430 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
431 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
432 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
433 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
434 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
435 #define EXT4_VERITY_FL			0x00100000 /* Verity protected inode */
436 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
437 /* 0x00400000 was formerly EXT4_EOFBLOCKS_FL */
438 
439 #define EXT4_DAX_FL			0x02000000 /* Inode is DAX */
440 
441 #define EXT4_INLINE_DATA_FL		0x10000000 /* Inode has inline data. */
442 #define EXT4_PROJINHERIT_FL		0x20000000 /* Create with parents projid */
443 #define EXT4_CASEFOLD_FL		0x40000000 /* Casefolded directory */
444 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
445 
446 /* User modifiable flags */
447 #define EXT4_FL_USER_MODIFIABLE		(EXT4_SECRM_FL | \
448 					 EXT4_UNRM_FL | \
449 					 EXT4_COMPR_FL | \
450 					 EXT4_SYNC_FL | \
451 					 EXT4_IMMUTABLE_FL | \
452 					 EXT4_APPEND_FL | \
453 					 EXT4_NODUMP_FL | \
454 					 EXT4_NOATIME_FL | \
455 					 EXT4_JOURNAL_DATA_FL | \
456 					 EXT4_NOTAIL_FL | \
457 					 EXT4_DIRSYNC_FL | \
458 					 EXT4_TOPDIR_FL | \
459 					 EXT4_EXTENTS_FL | \
460 					 0x00400000 /* EXT4_EOFBLOCKS_FL */ | \
461 					 EXT4_DAX_FL | \
462 					 EXT4_PROJINHERIT_FL | \
463 					 EXT4_CASEFOLD_FL)
464 
465 /* User visible flags */
466 #define EXT4_FL_USER_VISIBLE		(EXT4_FL_USER_MODIFIABLE | \
467 					 EXT4_DIRTY_FL | \
468 					 EXT4_COMPRBLK_FL | \
469 					 EXT4_NOCOMPR_FL | \
470 					 EXT4_ENCRYPT_FL | \
471 					 EXT4_INDEX_FL | \
472 					 EXT4_VERITY_FL | \
473 					 EXT4_INLINE_DATA_FL)
474 
475 /* Flags we can manipulate with through FS_IOC_FSSETXATTR */
476 #define EXT4_FL_XFLAG_VISIBLE		(EXT4_SYNC_FL | \
477 					 EXT4_IMMUTABLE_FL | \
478 					 EXT4_APPEND_FL | \
479 					 EXT4_NODUMP_FL | \
480 					 EXT4_NOATIME_FL | \
481 					 EXT4_PROJINHERIT_FL | \
482 					 EXT4_DAX_FL)
483 
484 /* Flags that should be inherited by new inodes from their parent. */
485 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
486 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
487 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
488 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL |\
489 			   EXT4_PROJINHERIT_FL | EXT4_CASEFOLD_FL |\
490 			   EXT4_DAX_FL)
491 
492 /* Flags that are appropriate for regular files (all but dir-specific ones). */
493 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL | EXT4_CASEFOLD_FL |\
494 			   EXT4_PROJINHERIT_FL))
495 
496 /* Flags that are appropriate for non-directories/regular files. */
497 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
498 
499 /* The only flags that should be swapped */
500 #define EXT4_FL_SHOULD_SWAP (EXT4_HUGE_FILE_FL | EXT4_EXTENTS_FL)
501 
502 /* Flags which are mutually exclusive to DAX */
503 #define EXT4_DAX_MUT_EXCL (EXT4_VERITY_FL | EXT4_ENCRYPT_FL |\
504 			   EXT4_JOURNAL_DATA_FL | EXT4_INLINE_DATA_FL)
505 
506 /* Mask out flags that are inappropriate for the given type of inode. */
507 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
508 {
509 	if (S_ISDIR(mode))
510 		return flags;
511 	else if (S_ISREG(mode))
512 		return flags & EXT4_REG_FLMASK;
513 	else
514 		return flags & EXT4_OTHER_FLMASK;
515 }
516 
517 /*
518  * Inode flags used for atomic set/get
519  */
520 enum {
521 	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
522 	EXT4_INODE_UNRM		= 1,	/* Undelete */
523 	EXT4_INODE_COMPR	= 2,	/* Compress file */
524 	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
525 	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
526 	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
527 	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
528 	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
529 /* Reserved for compression usage... */
530 	EXT4_INODE_DIRTY	= 8,
531 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
532 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
533 	EXT4_INODE_ENCRYPT	= 11,	/* Encrypted file */
534 /* End compression flags --- maybe not all used */
535 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
536 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
537 	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
538 	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
539 	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
540 	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
541 	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
542 	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
543 	EXT4_INODE_VERITY	= 20,	/* Verity protected inode */
544 	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
545 /* 22 was formerly EXT4_INODE_EOFBLOCKS */
546 	EXT4_INODE_DAX		= 25,	/* Inode is DAX */
547 	EXT4_INODE_INLINE_DATA	= 28,	/* Data in inode. */
548 	EXT4_INODE_PROJINHERIT	= 29,	/* Create with parents projid */
549 	EXT4_INODE_CASEFOLD	= 30,	/* Casefolded directory */
550 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
551 };
552 
553 /*
554  * Since it's pretty easy to mix up bit numbers and hex values, we use a
555  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
556  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
557  * any extra space in the compiled kernel image, otherwise, the build will fail.
558  * It's important that these values are the same, since we are using
559  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
560  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
561  * values found in ext2, ext3 and ext4 filesystems, and of course the values
562  * defined in e2fsprogs.
563  *
564  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
565  */
566 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
567 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
568 
569 static inline void ext4_check_flag_values(void)
570 {
571 	CHECK_FLAG_VALUE(SECRM);
572 	CHECK_FLAG_VALUE(UNRM);
573 	CHECK_FLAG_VALUE(COMPR);
574 	CHECK_FLAG_VALUE(SYNC);
575 	CHECK_FLAG_VALUE(IMMUTABLE);
576 	CHECK_FLAG_VALUE(APPEND);
577 	CHECK_FLAG_VALUE(NODUMP);
578 	CHECK_FLAG_VALUE(NOATIME);
579 	CHECK_FLAG_VALUE(DIRTY);
580 	CHECK_FLAG_VALUE(COMPRBLK);
581 	CHECK_FLAG_VALUE(NOCOMPR);
582 	CHECK_FLAG_VALUE(ENCRYPT);
583 	CHECK_FLAG_VALUE(INDEX);
584 	CHECK_FLAG_VALUE(IMAGIC);
585 	CHECK_FLAG_VALUE(JOURNAL_DATA);
586 	CHECK_FLAG_VALUE(NOTAIL);
587 	CHECK_FLAG_VALUE(DIRSYNC);
588 	CHECK_FLAG_VALUE(TOPDIR);
589 	CHECK_FLAG_VALUE(HUGE_FILE);
590 	CHECK_FLAG_VALUE(EXTENTS);
591 	CHECK_FLAG_VALUE(VERITY);
592 	CHECK_FLAG_VALUE(EA_INODE);
593 	CHECK_FLAG_VALUE(INLINE_DATA);
594 	CHECK_FLAG_VALUE(PROJINHERIT);
595 	CHECK_FLAG_VALUE(CASEFOLD);
596 	CHECK_FLAG_VALUE(RESERVED);
597 }
598 
599 /* Used to pass group descriptor data when online resize is done */
600 struct ext4_new_group_input {
601 	__u32 group;		/* Group number for this data */
602 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
603 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
604 	__u64 inode_table;	/* Absolute block number of inode table start */
605 	__u32 blocks_count;	/* Total number of blocks in this group */
606 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
607 	__u16 unused;
608 };
609 
610 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
611 struct compat_ext4_new_group_input {
612 	u32 group;
613 	compat_u64 block_bitmap;
614 	compat_u64 inode_bitmap;
615 	compat_u64 inode_table;
616 	u32 blocks_count;
617 	u16 reserved_blocks;
618 	u16 unused;
619 };
620 #endif
621 
622 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
623 struct ext4_new_group_data {
624 	__u32 group;
625 	__u64 block_bitmap;
626 	__u64 inode_bitmap;
627 	__u64 inode_table;
628 	__u32 blocks_count;
629 	__u16 reserved_blocks;
630 	__u16 mdata_blocks;
631 	__u32 free_clusters_count;
632 };
633 
634 /* Indexes used to index group tables in ext4_new_group_data */
635 enum {
636 	BLOCK_BITMAP = 0,	/* block bitmap */
637 	INODE_BITMAP,		/* inode bitmap */
638 	INODE_TABLE,		/* inode tables */
639 	GROUP_TABLE_COUNT,
640 };
641 
642 /*
643  * Flags used by ext4_map_blocks()
644  */
645 	/* Allocate any needed blocks and/or convert an unwritten
646 	   extent to be an initialized ext4 */
647 #define EXT4_GET_BLOCKS_CREATE			0x0001
648 	/* Request the creation of an unwritten extent */
649 #define EXT4_GET_BLOCKS_UNWRIT_EXT		0x0002
650 #define EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT	(EXT4_GET_BLOCKS_UNWRIT_EXT|\
651 						 EXT4_GET_BLOCKS_CREATE)
652 	/* Caller is from the delayed allocation writeout path
653 	 * finally doing the actual allocation of delayed blocks */
654 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
655 	/* caller is from the direct IO path, request to creation of an
656 	unwritten extents if not allocated, split the unwritten
657 	extent if blocks has been preallocated already*/
658 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
659 #define EXT4_GET_BLOCKS_CONVERT			0x0010
660 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
661 					 EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
662 	/* Convert extent to initialized after IO complete */
663 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
664 					 EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
665 	/* Eventual metadata allocation (due to growing extent tree)
666 	 * should not fail, so try to use reserved blocks for that.*/
667 #define EXT4_GET_BLOCKS_METADATA_NOFAIL		0x0020
668 	/* Don't normalize allocation size (used for fallocate) */
669 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
670 	/* Convert written extents to unwritten */
671 #define EXT4_GET_BLOCKS_CONVERT_UNWRITTEN	0x0100
672 	/* Write zeros to newly created written extents */
673 #define EXT4_GET_BLOCKS_ZERO			0x0200
674 #define EXT4_GET_BLOCKS_CREATE_ZERO		(EXT4_GET_BLOCKS_CREATE |\
675 					EXT4_GET_BLOCKS_ZERO)
676 	/* Caller will submit data before dropping transaction handle. This
677 	 * allows jbd2 to avoid submitting data before commit. */
678 #define EXT4_GET_BLOCKS_IO_SUBMIT		0x0400
679 
680 /*
681  * The bit position of these flags must not overlap with any of the
682  * EXT4_GET_BLOCKS_*.  They are used by ext4_find_extent(),
683  * read_extent_tree_block(), ext4_split_extent_at(),
684  * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf().
685  * EXT4_EX_NOCACHE is used to indicate that the we shouldn't be
686  * caching the extents when reading from the extent tree while a
687  * truncate or punch hole operation is in progress.
688  */
689 #define EXT4_EX_NOCACHE				0x40000000
690 #define EXT4_EX_FORCE_CACHE			0x20000000
691 #define EXT4_EX_NOFAIL				0x10000000
692 
693 /*
694  * Flags used by ext4_free_blocks
695  */
696 #define EXT4_FREE_BLOCKS_METADATA		0x0001
697 #define EXT4_FREE_BLOCKS_FORGET			0x0002
698 #define EXT4_FREE_BLOCKS_VALIDATED		0x0004
699 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE		0x0008
700 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
701 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
702 #define EXT4_FREE_BLOCKS_RERESERVE_CLUSTER      0x0040
703 
704 /*
705  * ioctl commands
706  */
707 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
708 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
709 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
710 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
711 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
712 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
713 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
714 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
715 #define EXT4_IOC_MIGRATE		_IO('f', 9)
716  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
717  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
718 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
719 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
720 #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
721 #define EXT4_IOC_SWAP_BOOT		_IO('f', 17)
722 #define EXT4_IOC_PRECACHE_EXTENTS	_IO('f', 18)
723 /* ioctl codes 19--39 are reserved for fscrypt */
724 #define EXT4_IOC_CLEAR_ES_CACHE		_IO('f', 40)
725 #define EXT4_IOC_GETSTATE		_IOW('f', 41, __u32)
726 #define EXT4_IOC_GET_ES_CACHE		_IOWR('f', 42, struct fiemap)
727 
728 #define EXT4_IOC_SHUTDOWN _IOR ('X', 125, __u32)
729 
730 /*
731  * Flags for going down operation
732  */
733 #define EXT4_GOING_FLAGS_DEFAULT		0x0	/* going down */
734 #define EXT4_GOING_FLAGS_LOGFLUSH		0x1	/* flush log but not data */
735 #define EXT4_GOING_FLAGS_NOLOGFLUSH		0x2	/* don't flush log nor data */
736 
737 /*
738  * Flags returned by EXT4_IOC_GETSTATE
739  *
740  * We only expose to userspace a subset of the state flags in
741  * i_state_flags
742  */
743 #define EXT4_STATE_FLAG_EXT_PRECACHED	0x00000001
744 #define EXT4_STATE_FLAG_NEW		0x00000002
745 #define EXT4_STATE_FLAG_NEWENTRY	0x00000004
746 #define EXT4_STATE_FLAG_DA_ALLOC_CLOSE	0x00000008
747 
748 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
749 /*
750  * ioctl commands in 32 bit emulation
751  */
752 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
753 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
754 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
755 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
756 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
757 #define EXT4_IOC32_GROUP_ADD		_IOW('f', 8, struct compat_ext4_new_group_input)
758 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
759 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
760 #endif
761 
762 /*
763  * Returned by EXT4_IOC_GET_ES_CACHE as an additional possible flag.
764  * It indicates that the entry in extent status cache is for a hole.
765  */
766 #define EXT4_FIEMAP_EXTENT_HOLE		0x08000000
767 
768 /* Max physical block we can address w/o extents */
769 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
770 
771 /* Max logical block we can support */
772 #define EXT4_MAX_LOGICAL_BLOCK		0xFFFFFFFE
773 
774 /*
775  * Structure of an inode on the disk
776  */
777 struct ext4_inode {
778 	__le16	i_mode;		/* File mode */
779 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
780 	__le32	i_size_lo;	/* Size in bytes */
781 	__le32	i_atime;	/* Access time */
782 	__le32	i_ctime;	/* Inode Change time */
783 	__le32	i_mtime;	/* Modification time */
784 	__le32	i_dtime;	/* Deletion Time */
785 	__le16	i_gid;		/* Low 16 bits of Group Id */
786 	__le16	i_links_count;	/* Links count */
787 	__le32	i_blocks_lo;	/* Blocks count */
788 	__le32	i_flags;	/* File flags */
789 	union {
790 		struct {
791 			__le32  l_i_version;
792 		} linux1;
793 		struct {
794 			__u32  h_i_translator;
795 		} hurd1;
796 		struct {
797 			__u32  m_i_reserved1;
798 		} masix1;
799 	} osd1;				/* OS dependent 1 */
800 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
801 	__le32	i_generation;	/* File version (for NFS) */
802 	__le32	i_file_acl_lo;	/* File ACL */
803 	__le32	i_size_high;
804 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
805 	union {
806 		struct {
807 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
808 			__le16	l_i_file_acl_high;
809 			__le16	l_i_uid_high;	/* these 2 fields */
810 			__le16	l_i_gid_high;	/* were reserved2[0] */
811 			__le16	l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
812 			__le16	l_i_reserved;
813 		} linux2;
814 		struct {
815 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
816 			__u16	h_i_mode_high;
817 			__u16	h_i_uid_high;
818 			__u16	h_i_gid_high;
819 			__u32	h_i_author;
820 		} hurd2;
821 		struct {
822 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
823 			__le16	m_i_file_acl_high;
824 			__u32	m_i_reserved2[2];
825 		} masix2;
826 	} osd2;				/* OS dependent 2 */
827 	__le16	i_extra_isize;
828 	__le16	i_checksum_hi;	/* crc32c(uuid+inum+inode) BE */
829 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
830 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
831 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
832 	__le32  i_crtime;       /* File Creation time */
833 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
834 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
835 	__le32	i_projid;	/* Project ID */
836 };
837 
838 struct move_extent {
839 	__u32 reserved;		/* should be zero */
840 	__u32 donor_fd;		/* donor file descriptor */
841 	__u64 orig_start;	/* logical start offset in block for orig */
842 	__u64 donor_start;	/* logical start offset in block for donor */
843 	__u64 len;		/* block length to be moved */
844 	__u64 moved_len;	/* moved block length */
845 };
846 
847 #define EXT4_EPOCH_BITS 2
848 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
849 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
850 
851 /*
852  * Extended fields will fit into an inode if the filesystem was formatted
853  * with large inodes (-I 256 or larger) and there are not currently any EAs
854  * consuming all of the available space. For new inodes we always reserve
855  * enough space for the kernel's known extended fields, but for inodes
856  * created with an old kernel this might not have been the case. None of
857  * the extended inode fields is critical for correct filesystem operation.
858  * This macro checks if a certain field fits in the inode. Note that
859  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
860  */
861 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
862 	((offsetof(typeof(*ext4_inode), field) +	\
863 	  sizeof((ext4_inode)->field))			\
864 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
865 	    (einode)->i_extra_isize))			\
866 
867 /*
868  * We use an encoding that preserves the times for extra epoch "00":
869  *
870  * extra  msb of                         adjust for signed
871  * epoch  32-bit                         32-bit tv_sec to
872  * bits   time    decoded 64-bit tv_sec  64-bit tv_sec      valid time range
873  * 0 0    1    -0x80000000..-0x00000001  0x000000000 1901-12-13..1969-12-31
874  * 0 0    0    0x000000000..0x07fffffff  0x000000000 1970-01-01..2038-01-19
875  * 0 1    1    0x080000000..0x0ffffffff  0x100000000 2038-01-19..2106-02-07
876  * 0 1    0    0x100000000..0x17fffffff  0x100000000 2106-02-07..2174-02-25
877  * 1 0    1    0x180000000..0x1ffffffff  0x200000000 2174-02-25..2242-03-16
878  * 1 0    0    0x200000000..0x27fffffff  0x200000000 2242-03-16..2310-04-04
879  * 1 1    1    0x280000000..0x2ffffffff  0x300000000 2310-04-04..2378-04-22
880  * 1 1    0    0x300000000..0x37fffffff  0x300000000 2378-04-22..2446-05-10
881  *
882  * Note that previous versions of the kernel on 64-bit systems would
883  * incorrectly use extra epoch bits 1,1 for dates between 1901 and
884  * 1970.  e2fsck will correct this, assuming that it is run on the
885  * affected filesystem before 2242.
886  */
887 
888 static inline __le32 ext4_encode_extra_time(struct timespec64 *time)
889 {
890 	u32 extra =((time->tv_sec - (s32)time->tv_sec) >> 32) & EXT4_EPOCH_MASK;
891 	return cpu_to_le32(extra | (time->tv_nsec << EXT4_EPOCH_BITS));
892 }
893 
894 static inline void ext4_decode_extra_time(struct timespec64 *time,
895 					  __le32 extra)
896 {
897 	if (unlikely(extra & cpu_to_le32(EXT4_EPOCH_MASK)))
898 		time->tv_sec += (u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK) << 32;
899 	time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
900 }
901 
902 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)				\
903 do {										\
904 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     {\
905 		(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	\
906 		(raw_inode)->xtime ## _extra =					\
907 				ext4_encode_extra_time(&(inode)->xtime);	\
908 		}								\
909 	else	\
910 		(raw_inode)->xtime = cpu_to_le32(clamp_t(int32_t, (inode)->xtime.tv_sec, S32_MIN, S32_MAX));	\
911 } while (0)
912 
913 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
914 do {									       \
915 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
916 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
917 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
918 		(raw_inode)->xtime ## _extra =				       \
919 				ext4_encode_extra_time(&(einode)->xtime);      \
920 } while (0)
921 
922 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)				\
923 do {										\
924 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);	\
925 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra)) {	\
926 		ext4_decode_extra_time(&(inode)->xtime,				\
927 				       raw_inode->xtime ## _extra);		\
928 		}								\
929 	else									\
930 		(inode)->xtime.tv_nsec = 0;					\
931 } while (0)
932 
933 
934 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
935 do {									       \
936 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
937 		(einode)->xtime.tv_sec = 				       \
938 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
939 	else								       \
940 		(einode)->xtime.tv_sec = 0;				       \
941 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
942 		ext4_decode_extra_time(&(einode)->xtime,		       \
943 				       raw_inode->xtime ## _extra);	       \
944 	else								       \
945 		(einode)->xtime.tv_nsec = 0;				       \
946 } while (0)
947 
948 #define i_disk_version osd1.linux1.l_i_version
949 
950 #if defined(__KERNEL__) || defined(__linux__)
951 #define i_reserved1	osd1.linux1.l_i_reserved1
952 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
953 #define i_blocks_high	osd2.linux2.l_i_blocks_high
954 #define i_uid_low	i_uid
955 #define i_gid_low	i_gid
956 #define i_uid_high	osd2.linux2.l_i_uid_high
957 #define i_gid_high	osd2.linux2.l_i_gid_high
958 #define i_checksum_lo	osd2.linux2.l_i_checksum_lo
959 
960 #elif defined(__GNU__)
961 
962 #define i_translator	osd1.hurd1.h_i_translator
963 #define i_uid_high	osd2.hurd2.h_i_uid_high
964 #define i_gid_high	osd2.hurd2.h_i_gid_high
965 #define i_author	osd2.hurd2.h_i_author
966 
967 #elif defined(__masix__)
968 
969 #define i_reserved1	osd1.masix1.m_i_reserved1
970 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
971 #define i_reserved2	osd2.masix2.m_i_reserved2
972 
973 #endif /* defined(__KERNEL__) || defined(__linux__) */
974 
975 #include "extents_status.h"
976 #include "fast_commit.h"
977 
978 /*
979  * Lock subclasses for i_data_sem in the ext4_inode_info structure.
980  *
981  * These are needed to avoid lockdep false positives when we need to
982  * allocate blocks to the quota inode during ext4_map_blocks(), while
983  * holding i_data_sem for a normal (non-quota) inode.  Since we don't
984  * do quota tracking for the quota inode, this avoids deadlock (as
985  * well as infinite recursion, since it isn't turtles all the way
986  * down...)
987  *
988  *  I_DATA_SEM_NORMAL - Used for most inodes
989  *  I_DATA_SEM_OTHER  - Used by move_inode.c for the second normal inode
990  *			  where the second inode has larger inode number
991  *			  than the first
992  *  I_DATA_SEM_QUOTA  - Used for quota inodes only
993  */
994 enum {
995 	I_DATA_SEM_NORMAL = 0,
996 	I_DATA_SEM_OTHER,
997 	I_DATA_SEM_QUOTA,
998 };
999 
1000 
1001 /*
1002  * fourth extended file system inode data in memory
1003  */
1004 struct ext4_inode_info {
1005 	__le32	i_data[15];	/* unconverted */
1006 	__u32	i_dtime;
1007 	ext4_fsblk_t	i_file_acl;
1008 
1009 	/*
1010 	 * i_block_group is the number of the block group which contains
1011 	 * this file's inode.  Constant across the lifetime of the inode,
1012 	 * it is used for making block allocation decisions - we try to
1013 	 * place a file's data blocks near its inode block, and new inodes
1014 	 * near to their parent directory's inode.
1015 	 */
1016 	ext4_group_t	i_block_group;
1017 	ext4_lblk_t	i_dir_start_lookup;
1018 #if (BITS_PER_LONG < 64)
1019 	unsigned long	i_state_flags;		/* Dynamic state flags */
1020 #endif
1021 	unsigned long	i_flags;
1022 
1023 	/*
1024 	 * Extended attributes can be read independently of the main file
1025 	 * data. Taking i_mutex even when reading would cause contention
1026 	 * between readers of EAs and writers of regular file data, so
1027 	 * instead we synchronize on xattr_sem when reading or changing
1028 	 * EAs.
1029 	 */
1030 	struct rw_semaphore xattr_sem;
1031 
1032 	struct list_head i_orphan;	/* unlinked but open inodes */
1033 
1034 	/* Fast commit related info */
1035 
1036 	struct list_head i_fc_list;	/*
1037 					 * inodes that need fast commit
1038 					 * protected by sbi->s_fc_lock.
1039 					 */
1040 
1041 	/* Start of lblk range that needs to be committed in this fast commit */
1042 	ext4_lblk_t i_fc_lblk_start;
1043 
1044 	/* End of lblk range that needs to be committed in this fast commit */
1045 	ext4_lblk_t i_fc_lblk_len;
1046 
1047 	/* Number of ongoing updates on this inode */
1048 	atomic_t  i_fc_updates;
1049 
1050 	/* Fast commit wait queue for this inode */
1051 	wait_queue_head_t i_fc_wait;
1052 
1053 	/* Protect concurrent accesses on i_fc_lblk_start, i_fc_lblk_len */
1054 	struct mutex i_fc_lock;
1055 
1056 	/*
1057 	 * i_disksize keeps track of what the inode size is ON DISK, not
1058 	 * in memory.  During truncate, i_size is set to the new size by
1059 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
1060 	 * set i_disksize to 0 until the truncate is actually under way.
1061 	 *
1062 	 * The intent is that i_disksize always represents the blocks which
1063 	 * are used by this file.  This allows recovery to restart truncate
1064 	 * on orphans if we crash during truncate.  We actually write i_disksize
1065 	 * into the on-disk inode when writing inodes out, instead of i_size.
1066 	 *
1067 	 * The only time when i_disksize and i_size may be different is when
1068 	 * a truncate is in progress.  The only things which change i_disksize
1069 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
1070 	 */
1071 	loff_t	i_disksize;
1072 
1073 	/*
1074 	 * i_data_sem is for serialising ext4_truncate() against
1075 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
1076 	 * data tree are chopped off during truncate. We can't do that in
1077 	 * ext4 because whenever we perform intermediate commits during
1078 	 * truncate, the inode and all the metadata blocks *must* be in a
1079 	 * consistent state which allows truncation of the orphans to restart
1080 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
1081 	 * by other means, so we have i_data_sem.
1082 	 */
1083 	struct rw_semaphore i_data_sem;
1084 	/*
1085 	 * i_mmap_sem is for serializing page faults with truncate / punch hole
1086 	 * operations. We have to make sure that new page cannot be faulted in
1087 	 * a section of the inode that is being punched. We cannot easily use
1088 	 * i_data_sem for this since we need protection for the whole punch
1089 	 * operation and i_data_sem ranks below transaction start so we have
1090 	 * to occasionally drop it.
1091 	 */
1092 	struct rw_semaphore i_mmap_sem;
1093 	struct inode vfs_inode;
1094 	struct jbd2_inode *jinode;
1095 
1096 	spinlock_t i_raw_lock;	/* protects updates to the raw inode */
1097 
1098 	/*
1099 	 * File creation time. Its function is same as that of
1100 	 * struct timespec64 i_{a,c,m}time in the generic inode.
1101 	 */
1102 	struct timespec64 i_crtime;
1103 
1104 	/* mballoc */
1105 	atomic_t i_prealloc_active;
1106 	struct list_head i_prealloc_list;
1107 	spinlock_t i_prealloc_lock;
1108 
1109 	/* extents status tree */
1110 	struct ext4_es_tree i_es_tree;
1111 	rwlock_t i_es_lock;
1112 	struct list_head i_es_list;
1113 	unsigned int i_es_all_nr;	/* protected by i_es_lock */
1114 	unsigned int i_es_shk_nr;	/* protected by i_es_lock */
1115 	ext4_lblk_t i_es_shrink_lblk;	/* Offset where we start searching for
1116 					   extents to shrink. Protected by
1117 					   i_es_lock  */
1118 
1119 	/* ialloc */
1120 	ext4_group_t	i_last_alloc_group;
1121 
1122 	/* allocation reservation info for delalloc */
1123 	/* In case of bigalloc, this refer to clusters rather than blocks */
1124 	unsigned int i_reserved_data_blocks;
1125 
1126 	/* pending cluster reservations for bigalloc file systems */
1127 	struct ext4_pending_tree i_pending_tree;
1128 
1129 	/* on-disk additional length */
1130 	__u16 i_extra_isize;
1131 
1132 	/* Indicate the inline data space. */
1133 	u16 i_inline_off;
1134 	u16 i_inline_size;
1135 
1136 #ifdef CONFIG_QUOTA
1137 	/* quota space reservation, managed internally by quota code */
1138 	qsize_t i_reserved_quota;
1139 #endif
1140 
1141 	/* Lock protecting lists below */
1142 	spinlock_t i_completed_io_lock;
1143 	/*
1144 	 * Completed IOs that need unwritten extents handling and have
1145 	 * transaction reserved
1146 	 */
1147 	struct list_head i_rsv_conversion_list;
1148 	struct work_struct i_rsv_conversion_work;
1149 	atomic_t i_unwritten; /* Nr. of inflight conversions pending */
1150 
1151 	spinlock_t i_block_reservation_lock;
1152 
1153 	/*
1154 	 * Transactions that contain inode's metadata needed to complete
1155 	 * fsync and fdatasync, respectively.
1156 	 */
1157 	tid_t i_sync_tid;
1158 	tid_t i_datasync_tid;
1159 
1160 #ifdef CONFIG_QUOTA
1161 	struct dquot *i_dquot[MAXQUOTAS];
1162 #endif
1163 
1164 	/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
1165 	__u32 i_csum_seed;
1166 
1167 	kprojid_t i_projid;
1168 };
1169 
1170 /*
1171  * File system states
1172  */
1173 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
1174 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
1175 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
1176 #define EXT4_FC_REPLAY			0x0020	/* Fast commit replay ongoing */
1177 
1178 /*
1179  * Misc. filesystem flags
1180  */
1181 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
1182 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
1183 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
1184 
1185 /*
1186  * Mount flags set via mount options or defaults
1187  */
1188 #define EXT4_MOUNT_NO_MBCACHE		0x00001 /* Do not use mbcache */
1189 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
1190 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
1191 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
1192 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
1193 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
1194 #define EXT4_MOUNT_ERRORS_MASK		0x00070
1195 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
1196 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
1197 #ifdef CONFIG_FS_DAX
1198 #define EXT4_MOUNT_DAX_ALWAYS		0x00200	/* Direct Access */
1199 #else
1200 #define EXT4_MOUNT_DAX_ALWAYS		0
1201 #endif
1202 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
1203 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
1204 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
1205 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
1206 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
1207 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
1208 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
1209 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
1210 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
1211 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
1212 #define EXT4_MOUNT_QUOTA		0x40000 /* Some quota option set */
1213 #define EXT4_MOUNT_USRQUOTA		0x80000 /* "old" user quota,
1214 						 * enable enforcement for hidden
1215 						 * quota files */
1216 #define EXT4_MOUNT_GRPQUOTA		0x100000 /* "old" group quota, enable
1217 						  * enforcement for hidden quota
1218 						  * files */
1219 #define EXT4_MOUNT_PRJQUOTA		0x200000 /* Enable project quota
1220 						  * enforcement */
1221 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
1222 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
1223 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
1224 #define EXT4_MOUNT_WARN_ON_ERROR	0x2000000 /* Trigger WARN_ON on error */
1225 #define EXT4_MOUNT_PREFETCH_BLOCK_BITMAPS 0x4000000
1226 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
1227 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
1228 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
1229 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
1230 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
1231 
1232 /*
1233  * Mount flags set either automatically (could not be set by mount option)
1234  * based on per file system feature or property or in special cases such as
1235  * distinguishing between explicit mount option definition and default.
1236  */
1237 #define EXT4_MOUNT2_EXPLICIT_DELALLOC	0x00000001 /* User explicitly
1238 						      specified delalloc */
1239 #define EXT4_MOUNT2_STD_GROUP_SIZE	0x00000002 /* We have standard group
1240 						      size of blocksize * 8
1241 						      blocks */
1242 #define EXT4_MOUNT2_HURD_COMPAT		0x00000004 /* Support HURD-castrated
1243 						      file systems */
1244 #define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM	0x00000008 /* User explicitly
1245 						specified journal checksum */
1246 
1247 #define EXT4_MOUNT2_JOURNAL_FAST_COMMIT	0x00000010 /* Journal fast commit */
1248 #define EXT4_MOUNT2_DAX_NEVER		0x00000020 /* Do not allow Direct Access */
1249 #define EXT4_MOUNT2_DAX_INODE		0x00000040 /* For printing options only */
1250 
1251 
1252 #define clear_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt &= \
1253 						~EXT4_MOUNT_##opt
1254 #define set_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt |= \
1255 						EXT4_MOUNT_##opt
1256 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
1257 					 EXT4_MOUNT_##opt)
1258 
1259 #define clear_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 &= \
1260 						~EXT4_MOUNT2_##opt
1261 #define set_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 |= \
1262 						EXT4_MOUNT2_##opt
1263 #define test_opt2(sb, opt)		(EXT4_SB(sb)->s_mount_opt2 & \
1264 					 EXT4_MOUNT2_##opt)
1265 
1266 #define ext4_test_and_set_bit		__test_and_set_bit_le
1267 #define ext4_set_bit			__set_bit_le
1268 #define ext4_set_bit_atomic		ext2_set_bit_atomic
1269 #define ext4_test_and_clear_bit		__test_and_clear_bit_le
1270 #define ext4_clear_bit			__clear_bit_le
1271 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
1272 #define ext4_test_bit			test_bit_le
1273 #define ext4_find_next_zero_bit		find_next_zero_bit_le
1274 #define ext4_find_next_bit		find_next_bit_le
1275 
1276 extern void ext4_set_bits(void *bm, int cur, int len);
1277 
1278 /*
1279  * Maximal mount counts between two filesystem checks
1280  */
1281 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
1282 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
1283 
1284 /*
1285  * Behaviour when detecting errors
1286  */
1287 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
1288 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
1289 #define EXT4_ERRORS_PANIC		3	/* Panic */
1290 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
1291 
1292 /* Metadata checksum algorithm codes */
1293 #define EXT4_CRC32C_CHKSUM		1
1294 
1295 /*
1296  * Structure of the super block
1297  */
1298 struct ext4_super_block {
1299 /*00*/	__le32	s_inodes_count;		/* Inodes count */
1300 	__le32	s_blocks_count_lo;	/* Blocks count */
1301 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
1302 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
1303 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
1304 	__le32	s_first_data_block;	/* First Data Block */
1305 	__le32	s_log_block_size;	/* Block size */
1306 	__le32	s_log_cluster_size;	/* Allocation cluster size */
1307 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
1308 	__le32	s_clusters_per_group;	/* # Clusters per group */
1309 	__le32	s_inodes_per_group;	/* # Inodes per group */
1310 	__le32	s_mtime;		/* Mount time */
1311 /*30*/	__le32	s_wtime;		/* Write time */
1312 	__le16	s_mnt_count;		/* Mount count */
1313 	__le16	s_max_mnt_count;	/* Maximal mount count */
1314 	__le16	s_magic;		/* Magic signature */
1315 	__le16	s_state;		/* File system state */
1316 	__le16	s_errors;		/* Behaviour when detecting errors */
1317 	__le16	s_minor_rev_level;	/* minor revision level */
1318 /*40*/	__le32	s_lastcheck;		/* time of last check */
1319 	__le32	s_checkinterval;	/* max. time between checks */
1320 	__le32	s_creator_os;		/* OS */
1321 	__le32	s_rev_level;		/* Revision level */
1322 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
1323 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
1324 	/*
1325 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
1326 	 *
1327 	 * Note: the difference between the compatible feature set and
1328 	 * the incompatible feature set is that if there is a bit set
1329 	 * in the incompatible feature set that the kernel doesn't
1330 	 * know about, it should refuse to mount the filesystem.
1331 	 *
1332 	 * e2fsck's requirements are more strict; if it doesn't know
1333 	 * about a feature in either the compatible or incompatible
1334 	 * feature set, it must abort and not try to meddle with
1335 	 * things it doesn't understand...
1336 	 */
1337 	__le32	s_first_ino;		/* First non-reserved inode */
1338 	__le16  s_inode_size;		/* size of inode structure */
1339 	__le16	s_block_group_nr;	/* block group # of this superblock */
1340 	__le32	s_feature_compat;	/* compatible feature set */
1341 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
1342 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
1343 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
1344 /*78*/	char	s_volume_name[16];	/* volume name */
1345 /*88*/	char	s_last_mounted[64] __nonstring;	/* directory where last mounted */
1346 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
1347 	/*
1348 	 * Performance hints.  Directory preallocation should only
1349 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1350 	 */
1351 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
1352 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
1353 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
1354 	/*
1355 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1356 	 */
1357 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
1358 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
1359 	__le32	s_journal_dev;		/* device number of journal file */
1360 	__le32	s_last_orphan;		/* start of list of inodes to delete */
1361 	__le32	s_hash_seed[4];		/* HTREE hash seed */
1362 	__u8	s_def_hash_version;	/* Default hash version to use */
1363 	__u8	s_jnl_backup_type;
1364 	__le16  s_desc_size;		/* size of group descriptor */
1365 /*100*/	__le32	s_default_mount_opts;
1366 	__le32	s_first_meta_bg;	/* First metablock block group */
1367 	__le32	s_mkfs_time;		/* When the filesystem was created */
1368 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
1369 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1370 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
1371 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
1372 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
1373 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
1374 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
1375 	__le32	s_flags;		/* Miscellaneous flags */
1376 	__le16  s_raid_stride;		/* RAID stride */
1377 	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1378 	__le64  s_mmp_block;            /* Block for multi-mount protection */
1379 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1380 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
1381 	__u8	s_checksum_type;	/* metadata checksum algorithm used */
1382 	__u8	s_encryption_level;	/* versioning level for encryption */
1383 	__u8	s_reserved_pad;		/* Padding to next 32bits */
1384 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1385 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
1386 	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
1387 	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
1388 					      snapshot's future use */
1389 	__le32	s_snapshot_list;	/* inode number of the head of the
1390 					   on-disk snapshot list */
1391 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1392 	__le32	s_error_count;		/* number of fs errors */
1393 	__le32	s_first_error_time;	/* first time an error happened */
1394 	__le32	s_first_error_ino;	/* inode involved in first error */
1395 	__le64	s_first_error_block;	/* block involved of first error */
1396 	__u8	s_first_error_func[32] __nonstring;	/* function where the error happened */
1397 	__le32	s_first_error_line;	/* line number where error happened */
1398 	__le32	s_last_error_time;	/* most recent time of an error */
1399 	__le32	s_last_error_ino;	/* inode involved in last error */
1400 	__le32	s_last_error_line;	/* line number where error happened */
1401 	__le64	s_last_error_block;	/* block involved of last error */
1402 	__u8	s_last_error_func[32] __nonstring;	/* function where the error happened */
1403 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1404 	__u8	s_mount_opts[64];
1405 	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
1406 	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
1407 	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
1408 	__le32	s_backup_bgs[2];	/* groups with sparse_super2 SBs */
1409 	__u8	s_encrypt_algos[4];	/* Encryption algorithms in use  */
1410 	__u8	s_encrypt_pw_salt[16];	/* Salt used for string2key algorithm */
1411 	__le32	s_lpf_ino;		/* Location of the lost+found inode */
1412 	__le32	s_prj_quota_inum;	/* inode for tracking project quota */
1413 	__le32	s_checksum_seed;	/* crc32c(uuid) if csum_seed set */
1414 	__u8	s_wtime_hi;
1415 	__u8	s_mtime_hi;
1416 	__u8	s_mkfs_time_hi;
1417 	__u8	s_lastcheck_hi;
1418 	__u8	s_first_error_time_hi;
1419 	__u8	s_last_error_time_hi;
1420 	__u8	s_first_error_errcode;
1421 	__u8    s_last_error_errcode;
1422 	__le16  s_encoding;		/* Filename charset encoding */
1423 	__le16  s_encoding_flags;	/* Filename charset encoding flags */
1424 	__le32	s_reserved[95];		/* Padding to the end of the block */
1425 	__le32	s_checksum;		/* crc32c(superblock) */
1426 };
1427 
1428 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1429 
1430 #ifdef __KERNEL__
1431 
1432 #ifdef CONFIG_FS_ENCRYPTION
1433 #define DUMMY_ENCRYPTION_ENABLED(sbi) ((sbi)->s_dummy_enc_policy.policy != NULL)
1434 #else
1435 #define DUMMY_ENCRYPTION_ENABLED(sbi) (0)
1436 #endif
1437 
1438 /* Number of quota types we support */
1439 #define EXT4_MAXQUOTAS 3
1440 
1441 #define EXT4_ENC_UTF8_12_1	1
1442 
1443 /*
1444  * fourth extended-fs super-block data in memory
1445  */
1446 struct ext4_sb_info {
1447 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
1448 	unsigned long s_inodes_per_block;/* Number of inodes per block */
1449 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
1450 	unsigned long s_clusters_per_group; /* Number of clusters in a group */
1451 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
1452 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
1453 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
1454 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
1455 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1456 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1457 	unsigned long s_overhead;  /* # of fs overhead clusters */
1458 	unsigned int s_cluster_ratio;	/* Number of blocks per cluster */
1459 	unsigned int s_cluster_bits;	/* log2 of s_cluster_ratio */
1460 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
1461 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
1462 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
1463 	struct buffer_head * __rcu *s_group_desc;
1464 	unsigned int s_mount_opt;
1465 	unsigned int s_mount_opt2;
1466 	unsigned long s_mount_flags;
1467 	unsigned int s_def_mount_opt;
1468 	ext4_fsblk_t s_sb_block;
1469 	atomic64_t s_resv_clusters;
1470 	kuid_t s_resuid;
1471 	kgid_t s_resgid;
1472 	unsigned short s_mount_state;
1473 	unsigned short s_pad;
1474 	int s_addr_per_block_bits;
1475 	int s_desc_per_block_bits;
1476 	int s_inode_size;
1477 	int s_first_ino;
1478 	unsigned int s_inode_readahead_blks;
1479 	unsigned int s_inode_goal;
1480 	u32 s_hash_seed[4];
1481 	int s_def_hash_version;
1482 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
1483 	struct percpu_counter s_freeclusters_counter;
1484 	struct percpu_counter s_freeinodes_counter;
1485 	struct percpu_counter s_dirs_counter;
1486 	struct percpu_counter s_dirtyclusters_counter;
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 
1493 	/* Journaling */
1494 	struct journal_s *s_journal;
1495 	struct list_head s_orphan;
1496 	struct mutex s_orphan_lock;
1497 	unsigned long s_ext4_flags;		/* Ext4 superblock flags */
1498 	unsigned long s_commit_interval;
1499 	u32 s_max_batch_time;
1500 	u32 s_min_batch_time;
1501 	struct block_device *s_journal_bdev;
1502 #ifdef CONFIG_QUOTA
1503 	/* Names of quota files with journalled quota */
1504 	char __rcu *s_qf_names[EXT4_MAXQUOTAS];
1505 	int s_jquota_fmt;			/* Format of quota to use */
1506 #endif
1507 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1508 	struct ext4_system_blocks __rcu *s_system_blks;
1509 
1510 #ifdef EXTENTS_STATS
1511 	/* ext4 extents stats */
1512 	unsigned long s_ext_min;
1513 	unsigned long s_ext_max;
1514 	unsigned long s_depth_max;
1515 	spinlock_t s_ext_stats_lock;
1516 	unsigned long s_ext_blocks;
1517 	unsigned long s_ext_extents;
1518 #endif
1519 
1520 	/* for buddy allocator */
1521 	struct ext4_group_info ** __rcu *s_group_info;
1522 	struct inode *s_buddy_cache;
1523 	spinlock_t s_md_lock;
1524 	unsigned short *s_mb_offsets;
1525 	unsigned int *s_mb_maxs;
1526 	unsigned int s_group_info_size;
1527 	unsigned int s_mb_free_pending;
1528 	struct list_head s_freed_data_list;	/* List of blocks to be freed
1529 						   after commit completed */
1530 
1531 	/* tunables */
1532 	unsigned long s_stripe;
1533 	unsigned int s_mb_stream_request;
1534 	unsigned int s_mb_max_to_scan;
1535 	unsigned int s_mb_min_to_scan;
1536 	unsigned int s_mb_stats;
1537 	unsigned int s_mb_order2_reqs;
1538 	unsigned int s_mb_group_prealloc;
1539 	unsigned int s_mb_max_inode_prealloc;
1540 	unsigned int s_max_dir_size_kb;
1541 	/* where last allocation was done - for stream allocation */
1542 	unsigned long s_mb_last_group;
1543 	unsigned long s_mb_last_start;
1544 	unsigned int s_mb_prefetch;
1545 	unsigned int s_mb_prefetch_limit;
1546 
1547 	/* stats for buddy allocator */
1548 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1549 	atomic_t s_bal_success;	/* we found long enough chunks */
1550 	atomic_t s_bal_allocated;	/* in blocks */
1551 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1552 	atomic_t s_bal_goals;	/* goal hits */
1553 	atomic_t s_bal_breaks;	/* too long searches */
1554 	atomic_t s_bal_2orders;	/* 2^order hits */
1555 	spinlock_t s_bal_lock;
1556 	unsigned long s_mb_buddies_generated;
1557 	unsigned long long s_mb_generation_time;
1558 	atomic_t s_mb_lost_chunks;
1559 	atomic_t s_mb_preallocated;
1560 	atomic_t s_mb_discarded;
1561 	atomic_t s_lock_busy;
1562 
1563 	/* locality groups */
1564 	struct ext4_locality_group __percpu *s_locality_groups;
1565 
1566 	/* for write statistics */
1567 	unsigned long s_sectors_written_start;
1568 	u64 s_kbytes_written;
1569 
1570 	/* the size of zero-out chunk */
1571 	unsigned int s_extent_max_zeroout_kb;
1572 
1573 	unsigned int s_log_groups_per_flex;
1574 	struct flex_groups * __rcu *s_flex_groups;
1575 	ext4_group_t s_flex_groups_allocated;
1576 
1577 	/* workqueue for reserved extent conversions (buffered io) */
1578 	struct workqueue_struct *rsv_conversion_wq;
1579 
1580 	/* timer for periodic error stats printing */
1581 	struct timer_list s_err_report;
1582 
1583 	/* Lazy inode table initialization info */
1584 	struct ext4_li_request *s_li_request;
1585 	/* Wait multiplier for lazy initialization thread */
1586 	unsigned int s_li_wait_mult;
1587 
1588 	/* Kernel thread for multiple mount protection */
1589 	struct task_struct *s_mmp_tsk;
1590 
1591 	/* record the last minlen when FITRIM is called. */
1592 	atomic_t s_last_trim_minblks;
1593 
1594 	/* Reference to checksum algorithm driver via cryptoapi */
1595 	struct crypto_shash *s_chksum_driver;
1596 
1597 	/* Precomputed FS UUID checksum for seeding other checksums */
1598 	__u32 s_csum_seed;
1599 
1600 	/* Reclaim extents from extent status tree */
1601 	struct shrinker s_es_shrinker;
1602 	struct list_head s_es_list;	/* List of inodes with reclaimable extents */
1603 	long s_es_nr_inode;
1604 	struct ext4_es_stats s_es_stats;
1605 	struct mb_cache *s_ea_block_cache;
1606 	struct mb_cache *s_ea_inode_cache;
1607 	spinlock_t s_es_lock ____cacheline_aligned_in_smp;
1608 
1609 	/* Ratelimit ext4 messages. */
1610 	struct ratelimit_state s_err_ratelimit_state;
1611 	struct ratelimit_state s_warning_ratelimit_state;
1612 	struct ratelimit_state s_msg_ratelimit_state;
1613 	atomic_t s_warning_count;
1614 	atomic_t s_msg_count;
1615 
1616 	/* Encryption policy for '-o test_dummy_encryption' */
1617 	struct fscrypt_dummy_policy s_dummy_enc_policy;
1618 
1619 	/*
1620 	 * Barrier between writepages ops and changing any inode's JOURNAL_DATA
1621 	 * or EXTENTS flag.
1622 	 */
1623 	struct percpu_rw_semaphore s_writepages_rwsem;
1624 	struct dax_device *s_daxdev;
1625 #ifdef CONFIG_EXT4_DEBUG
1626 	unsigned long s_simulate_fail;
1627 #endif
1628 	/* Record the errseq of the backing block device */
1629 	errseq_t s_bdev_wb_err;
1630 	spinlock_t s_bdev_wb_lock;
1631 
1632 	/* Information about errors that happened during this mount */
1633 	spinlock_t s_error_lock;
1634 	int s_add_error_count;
1635 	int s_first_error_code;
1636 	__u32 s_first_error_line;
1637 	__u32 s_first_error_ino;
1638 	__u64 s_first_error_block;
1639 	const char *s_first_error_func;
1640 	time64_t s_first_error_time;
1641 	int s_last_error_code;
1642 	__u32 s_last_error_line;
1643 	__u32 s_last_error_ino;
1644 	__u64 s_last_error_block;
1645 	const char *s_last_error_func;
1646 	time64_t s_last_error_time;
1647 	/*
1648 	 * If we are in a context where we cannot update error information in
1649 	 * the on-disk superblock, we queue this work to do it.
1650 	 */
1651 	struct work_struct s_error_work;
1652 
1653 	/* Ext4 fast commit stuff */
1654 	atomic_t s_fc_subtid;
1655 	atomic_t s_fc_ineligible_updates;
1656 	/*
1657 	 * After commit starts, the main queue gets locked, and the further
1658 	 * updates get added in the staging queue.
1659 	 */
1660 #define FC_Q_MAIN	0
1661 #define FC_Q_STAGING	1
1662 	struct list_head s_fc_q[2];	/* Inodes staged for fast commit
1663 					 * that have data changes in them.
1664 					 */
1665 	struct list_head s_fc_dentry_q[2];	/* directory entry updates */
1666 	unsigned int s_fc_bytes;
1667 	/*
1668 	 * Main fast commit lock. This lock protects accesses to the
1669 	 * following fields:
1670 	 * ei->i_fc_list, s_fc_dentry_q, s_fc_q, s_fc_bytes, s_fc_bh.
1671 	 */
1672 	spinlock_t s_fc_lock;
1673 	struct buffer_head *s_fc_bh;
1674 	struct ext4_fc_stats s_fc_stats;
1675 	u64 s_fc_avg_commit_time;
1676 #ifdef CONFIG_EXT4_DEBUG
1677 	int s_fc_debug_max_replay;
1678 #endif
1679 	struct ext4_fc_replay_state s_fc_replay_state;
1680 };
1681 
1682 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1683 {
1684 	return sb->s_fs_info;
1685 }
1686 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1687 {
1688 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1689 }
1690 
1691 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1692 {
1693 	return ino == EXT4_ROOT_INO ||
1694 		(ino >= EXT4_FIRST_INO(sb) &&
1695 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1696 }
1697 
1698 /*
1699  * Returns: sbi->field[index]
1700  * Used to access an array element from the following sbi fields which require
1701  * rcu protection to avoid dereferencing an invalid pointer due to reassignment
1702  * - s_group_desc
1703  * - s_group_info
1704  * - s_flex_group
1705  */
1706 #define sbi_array_rcu_deref(sbi, field, index)				   \
1707 ({									   \
1708 	typeof(*((sbi)->field)) _v;					   \
1709 	rcu_read_lock();						   \
1710 	_v = ((typeof(_v)*)rcu_dereference((sbi)->field))[index];	   \
1711 	rcu_read_unlock();						   \
1712 	_v;								   \
1713 })
1714 
1715 /*
1716  * run-time mount flags
1717  */
1718 enum {
1719 	EXT4_MF_MNTDIR_SAMPLED,
1720 	EXT4_MF_FS_ABORTED,	/* Fatal error detected */
1721 	EXT4_MF_FC_INELIGIBLE,	/* Fast commit ineligible */
1722 	EXT4_MF_FC_COMMITTING	/* File system underoing a fast
1723 				 * commit.
1724 				 */
1725 };
1726 
1727 static inline void ext4_set_mount_flag(struct super_block *sb, int bit)
1728 {
1729 	set_bit(bit, &EXT4_SB(sb)->s_mount_flags);
1730 }
1731 
1732 static inline void ext4_clear_mount_flag(struct super_block *sb, int bit)
1733 {
1734 	clear_bit(bit, &EXT4_SB(sb)->s_mount_flags);
1735 }
1736 
1737 static inline int ext4_test_mount_flag(struct super_block *sb, int bit)
1738 {
1739 	return test_bit(bit, &EXT4_SB(sb)->s_mount_flags);
1740 }
1741 
1742 
1743 /*
1744  * Simulate_fail codes
1745  */
1746 #define EXT4_SIM_BBITMAP_EIO	1
1747 #define EXT4_SIM_BBITMAP_CRC	2
1748 #define EXT4_SIM_IBITMAP_EIO	3
1749 #define EXT4_SIM_IBITMAP_CRC	4
1750 #define EXT4_SIM_INODE_EIO	5
1751 #define EXT4_SIM_INODE_CRC	6
1752 #define EXT4_SIM_DIRBLOCK_EIO	7
1753 #define EXT4_SIM_DIRBLOCK_CRC	8
1754 
1755 static inline bool ext4_simulate_fail(struct super_block *sb,
1756 				     unsigned long code)
1757 {
1758 #ifdef CONFIG_EXT4_DEBUG
1759 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1760 
1761 	if (unlikely(sbi->s_simulate_fail == code)) {
1762 		sbi->s_simulate_fail = 0;
1763 		return true;
1764 	}
1765 #endif
1766 	return false;
1767 }
1768 
1769 static inline void ext4_simulate_fail_bh(struct super_block *sb,
1770 					 struct buffer_head *bh,
1771 					 unsigned long code)
1772 {
1773 	if (!IS_ERR(bh) && ext4_simulate_fail(sb, code))
1774 		clear_buffer_uptodate(bh);
1775 }
1776 
1777 /*
1778  * Error number codes for s_{first,last}_error_errno
1779  *
1780  * Linux errno numbers are architecture specific, so we need to translate
1781  * them into something which is architecture independent.   We don't define
1782  * codes for all errno's; just the ones which are most likely to be the cause
1783  * of an ext4_error() call.
1784  */
1785 #define EXT4_ERR_UNKNOWN	 1
1786 #define EXT4_ERR_EIO		 2
1787 #define EXT4_ERR_ENOMEM		 3
1788 #define EXT4_ERR_EFSBADCRC	 4
1789 #define EXT4_ERR_EFSCORRUPTED	 5
1790 #define EXT4_ERR_ENOSPC		 6
1791 #define EXT4_ERR_ENOKEY		 7
1792 #define EXT4_ERR_EROFS		 8
1793 #define EXT4_ERR_EFBIG		 9
1794 #define EXT4_ERR_EEXIST		10
1795 #define EXT4_ERR_ERANGE		11
1796 #define EXT4_ERR_EOVERFLOW	12
1797 #define EXT4_ERR_EBUSY		13
1798 #define EXT4_ERR_ENOTDIR	14
1799 #define EXT4_ERR_ENOTEMPTY	15
1800 #define EXT4_ERR_ESHUTDOWN	16
1801 #define EXT4_ERR_EFAULT		17
1802 
1803 /*
1804  * Inode dynamic state flags
1805  */
1806 enum {
1807 	EXT4_STATE_JDATA,		/* journaled data exists */
1808 	EXT4_STATE_NEW,			/* inode is newly created */
1809 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1810 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1811 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1812 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1813 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1814 	EXT4_STATE_MAY_INLINE_DATA,	/* may have in-inode data */
1815 	EXT4_STATE_EXT_PRECACHED,	/* extents have been precached */
1816 	EXT4_STATE_LUSTRE_EA_INODE,	/* Lustre-style ea_inode */
1817 	EXT4_STATE_VERITY_IN_PROGRESS,	/* building fs-verity Merkle tree */
1818 	EXT4_STATE_FC_COMMITTING,	/* Fast commit ongoing */
1819 };
1820 
1821 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
1822 static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
1823 {									\
1824 	return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);	\
1825 }									\
1826 static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
1827 {									\
1828 	set_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1829 }									\
1830 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1831 {									\
1832 	clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1833 }
1834 
1835 /* Add these declarations here only so that these functions can be
1836  * found by name.  Otherwise, they are very hard to locate. */
1837 static inline int ext4_test_inode_flag(struct inode *inode, int bit);
1838 static inline void ext4_set_inode_flag(struct inode *inode, int bit);
1839 static inline void ext4_clear_inode_flag(struct inode *inode, int bit);
1840 EXT4_INODE_BIT_FNS(flag, flags, 0)
1841 
1842 /* Add these declarations here only so that these functions can be
1843  * found by name.  Otherwise, they are very hard to locate. */
1844 static inline int ext4_test_inode_state(struct inode *inode, int bit);
1845 static inline void ext4_set_inode_state(struct inode *inode, int bit);
1846 static inline void ext4_clear_inode_state(struct inode *inode, int bit);
1847 #if (BITS_PER_LONG < 64)
1848 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1849 
1850 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1851 {
1852 	(ei)->i_state_flags = 0;
1853 }
1854 #else
1855 EXT4_INODE_BIT_FNS(state, flags, 32)
1856 
1857 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1858 {
1859 	/* We depend on the fact that callers will set i_flags */
1860 }
1861 #endif
1862 #else
1863 /* Assume that user mode programs are passing in an ext4fs superblock, not
1864  * a kernel struct super_block.  This will allow us to call the feature-test
1865  * macros from user land. */
1866 #define EXT4_SB(sb)	(sb)
1867 #endif
1868 
1869 static inline bool ext4_verity_in_progress(struct inode *inode)
1870 {
1871 	return IS_ENABLED(CONFIG_FS_VERITY) &&
1872 	       ext4_test_inode_state(inode, EXT4_STATE_VERITY_IN_PROGRESS);
1873 }
1874 
1875 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1876 
1877 /*
1878  * Codes for operating systems
1879  */
1880 #define EXT4_OS_LINUX		0
1881 #define EXT4_OS_HURD		1
1882 #define EXT4_OS_MASIX		2
1883 #define EXT4_OS_FREEBSD		3
1884 #define EXT4_OS_LITES		4
1885 
1886 /*
1887  * Revision levels
1888  */
1889 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1890 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1891 
1892 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1893 
1894 #define EXT4_GOOD_OLD_INODE_SIZE 128
1895 
1896 #define EXT4_EXTRA_TIMESTAMP_MAX	(((s64)1 << 34) - 1  + S32_MIN)
1897 #define EXT4_NON_EXTRA_TIMESTAMP_MAX	S32_MAX
1898 #define EXT4_TIMESTAMP_MIN		S32_MIN
1899 
1900 /*
1901  * Feature set definitions
1902  */
1903 
1904 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1905 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1906 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1907 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1908 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1909 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1910 #define EXT4_FEATURE_COMPAT_SPARSE_SUPER2	0x0200
1911 /*
1912  * The reason why "FAST_COMMIT" is a compat feature is that, FS becomes
1913  * incompatible only if fast commit blocks are present in the FS. Since we
1914  * clear the journal (and thus the fast commit blocks), we don't mark FS as
1915  * incompatible. We also have a JBD2 incompat feature, which gets set when
1916  * there are fast commit blocks present in the journal.
1917  */
1918 #define EXT4_FEATURE_COMPAT_FAST_COMMIT		0x0400
1919 #define EXT4_FEATURE_COMPAT_STABLE_INODES	0x0800
1920 
1921 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1922 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1923 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1924 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1925 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1926 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1927 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1928 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
1929 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
1930 /*
1931  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1932  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1933  * all other data structures' checksums.  However, the METADATA_CSUM and
1934  * GDT_CSUM bits are mutually exclusive.
1935  */
1936 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
1937 #define EXT4_FEATURE_RO_COMPAT_READONLY		0x1000
1938 #define EXT4_FEATURE_RO_COMPAT_PROJECT		0x2000
1939 #define EXT4_FEATURE_RO_COMPAT_VERITY		0x8000
1940 
1941 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1942 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1943 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1944 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1945 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1946 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1947 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1948 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1949 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1950 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1951 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1952 #define EXT4_FEATURE_INCOMPAT_CSUM_SEED		0x2000
1953 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
1954 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA	0x8000 /* data in inode */
1955 #define EXT4_FEATURE_INCOMPAT_ENCRYPT		0x10000
1956 #define EXT4_FEATURE_INCOMPAT_CASEFOLD		0x20000
1957 
1958 extern void ext4_update_dynamic_rev(struct super_block *sb);
1959 
1960 #define EXT4_FEATURE_COMPAT_FUNCS(name, flagname) \
1961 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1962 { \
1963 	return ((EXT4_SB(sb)->s_es->s_feature_compat & \
1964 		cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname)) != 0); \
1965 } \
1966 static inline void ext4_set_feature_##name(struct super_block *sb) \
1967 { \
1968 	ext4_update_dynamic_rev(sb); \
1969 	EXT4_SB(sb)->s_es->s_feature_compat |= \
1970 		cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname); \
1971 } \
1972 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1973 { \
1974 	EXT4_SB(sb)->s_es->s_feature_compat &= \
1975 		~cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname); \
1976 }
1977 
1978 #define EXT4_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
1979 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1980 { \
1981 	return ((EXT4_SB(sb)->s_es->s_feature_ro_compat & \
1982 		cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname)) != 0); \
1983 } \
1984 static inline void ext4_set_feature_##name(struct super_block *sb) \
1985 { \
1986 	ext4_update_dynamic_rev(sb); \
1987 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= \
1988 		cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname); \
1989 } \
1990 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1991 { \
1992 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= \
1993 		~cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname); \
1994 }
1995 
1996 #define EXT4_FEATURE_INCOMPAT_FUNCS(name, flagname) \
1997 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1998 { \
1999 	return ((EXT4_SB(sb)->s_es->s_feature_incompat & \
2000 		cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname)) != 0); \
2001 } \
2002 static inline void ext4_set_feature_##name(struct super_block *sb) \
2003 { \
2004 	ext4_update_dynamic_rev(sb); \
2005 	EXT4_SB(sb)->s_es->s_feature_incompat |= \
2006 		cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname); \
2007 } \
2008 static inline void ext4_clear_feature_##name(struct super_block *sb) \
2009 { \
2010 	EXT4_SB(sb)->s_es->s_feature_incompat &= \
2011 		~cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname); \
2012 }
2013 
2014 EXT4_FEATURE_COMPAT_FUNCS(dir_prealloc,		DIR_PREALLOC)
2015 EXT4_FEATURE_COMPAT_FUNCS(imagic_inodes,	IMAGIC_INODES)
2016 EXT4_FEATURE_COMPAT_FUNCS(journal,		HAS_JOURNAL)
2017 EXT4_FEATURE_COMPAT_FUNCS(xattr,		EXT_ATTR)
2018 EXT4_FEATURE_COMPAT_FUNCS(resize_inode,		RESIZE_INODE)
2019 EXT4_FEATURE_COMPAT_FUNCS(dir_index,		DIR_INDEX)
2020 EXT4_FEATURE_COMPAT_FUNCS(sparse_super2,	SPARSE_SUPER2)
2021 EXT4_FEATURE_COMPAT_FUNCS(fast_commit,		FAST_COMMIT)
2022 EXT4_FEATURE_COMPAT_FUNCS(stable_inodes,	STABLE_INODES)
2023 
2024 EXT4_FEATURE_RO_COMPAT_FUNCS(sparse_super,	SPARSE_SUPER)
2025 EXT4_FEATURE_RO_COMPAT_FUNCS(large_file,	LARGE_FILE)
2026 EXT4_FEATURE_RO_COMPAT_FUNCS(btree_dir,		BTREE_DIR)
2027 EXT4_FEATURE_RO_COMPAT_FUNCS(huge_file,		HUGE_FILE)
2028 EXT4_FEATURE_RO_COMPAT_FUNCS(gdt_csum,		GDT_CSUM)
2029 EXT4_FEATURE_RO_COMPAT_FUNCS(dir_nlink,		DIR_NLINK)
2030 EXT4_FEATURE_RO_COMPAT_FUNCS(extra_isize,	EXTRA_ISIZE)
2031 EXT4_FEATURE_RO_COMPAT_FUNCS(quota,		QUOTA)
2032 EXT4_FEATURE_RO_COMPAT_FUNCS(bigalloc,		BIGALLOC)
2033 EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum,	METADATA_CSUM)
2034 EXT4_FEATURE_RO_COMPAT_FUNCS(readonly,		READONLY)
2035 EXT4_FEATURE_RO_COMPAT_FUNCS(project,		PROJECT)
2036 EXT4_FEATURE_RO_COMPAT_FUNCS(verity,		VERITY)
2037 
2038 EXT4_FEATURE_INCOMPAT_FUNCS(compression,	COMPRESSION)
2039 EXT4_FEATURE_INCOMPAT_FUNCS(filetype,		FILETYPE)
2040 EXT4_FEATURE_INCOMPAT_FUNCS(journal_needs_recovery,	RECOVER)
2041 EXT4_FEATURE_INCOMPAT_FUNCS(journal_dev,	JOURNAL_DEV)
2042 EXT4_FEATURE_INCOMPAT_FUNCS(meta_bg,		META_BG)
2043 EXT4_FEATURE_INCOMPAT_FUNCS(extents,		EXTENTS)
2044 EXT4_FEATURE_INCOMPAT_FUNCS(64bit,		64BIT)
2045 EXT4_FEATURE_INCOMPAT_FUNCS(mmp,		MMP)
2046 EXT4_FEATURE_INCOMPAT_FUNCS(flex_bg,		FLEX_BG)
2047 EXT4_FEATURE_INCOMPAT_FUNCS(ea_inode,		EA_INODE)
2048 EXT4_FEATURE_INCOMPAT_FUNCS(dirdata,		DIRDATA)
2049 EXT4_FEATURE_INCOMPAT_FUNCS(csum_seed,		CSUM_SEED)
2050 EXT4_FEATURE_INCOMPAT_FUNCS(largedir,		LARGEDIR)
2051 EXT4_FEATURE_INCOMPAT_FUNCS(inline_data,	INLINE_DATA)
2052 EXT4_FEATURE_INCOMPAT_FUNCS(encrypt,		ENCRYPT)
2053 EXT4_FEATURE_INCOMPAT_FUNCS(casefold,		CASEFOLD)
2054 
2055 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
2056 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
2057 					 EXT4_FEATURE_INCOMPAT_META_BG)
2058 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
2059 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
2060 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
2061 
2062 #define EXT3_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
2063 #define EXT3_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
2064 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
2065 					 EXT4_FEATURE_INCOMPAT_META_BG)
2066 #define EXT3_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
2067 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
2068 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
2069 
2070 #define EXT4_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
2071 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
2072 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
2073 					 EXT4_FEATURE_INCOMPAT_META_BG| \
2074 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
2075 					 EXT4_FEATURE_INCOMPAT_64BIT| \
2076 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
2077 					 EXT4_FEATURE_INCOMPAT_EA_INODE| \
2078 					 EXT4_FEATURE_INCOMPAT_MMP | \
2079 					 EXT4_FEATURE_INCOMPAT_INLINE_DATA | \
2080 					 EXT4_FEATURE_INCOMPAT_ENCRYPT | \
2081 					 EXT4_FEATURE_INCOMPAT_CASEFOLD | \
2082 					 EXT4_FEATURE_INCOMPAT_CSUM_SEED | \
2083 					 EXT4_FEATURE_INCOMPAT_LARGEDIR)
2084 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
2085 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
2086 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
2087 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
2088 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
2089 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
2090 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
2091 					 EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
2092 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
2093 					 EXT4_FEATURE_RO_COMPAT_QUOTA |\
2094 					 EXT4_FEATURE_RO_COMPAT_PROJECT |\
2095 					 EXT4_FEATURE_RO_COMPAT_VERITY)
2096 
2097 #define EXTN_FEATURE_FUNCS(ver) \
2098 static inline bool ext4_has_unknown_ext##ver##_compat_features(struct super_block *sb) \
2099 { \
2100 	return ((EXT4_SB(sb)->s_es->s_feature_compat & \
2101 		cpu_to_le32(~EXT##ver##_FEATURE_COMPAT_SUPP)) != 0); \
2102 } \
2103 static inline bool ext4_has_unknown_ext##ver##_ro_compat_features(struct super_block *sb) \
2104 { \
2105 	return ((EXT4_SB(sb)->s_es->s_feature_ro_compat & \
2106 		cpu_to_le32(~EXT##ver##_FEATURE_RO_COMPAT_SUPP)) != 0); \
2107 } \
2108 static inline bool ext4_has_unknown_ext##ver##_incompat_features(struct super_block *sb) \
2109 { \
2110 	return ((EXT4_SB(sb)->s_es->s_feature_incompat & \
2111 		cpu_to_le32(~EXT##ver##_FEATURE_INCOMPAT_SUPP)) != 0); \
2112 }
2113 
2114 EXTN_FEATURE_FUNCS(2)
2115 EXTN_FEATURE_FUNCS(3)
2116 EXTN_FEATURE_FUNCS(4)
2117 
2118 static inline bool ext4_has_compat_features(struct super_block *sb)
2119 {
2120 	return (EXT4_SB(sb)->s_es->s_feature_compat != 0);
2121 }
2122 static inline bool ext4_has_ro_compat_features(struct super_block *sb)
2123 {
2124 	return (EXT4_SB(sb)->s_es->s_feature_ro_compat != 0);
2125 }
2126 static inline bool ext4_has_incompat_features(struct super_block *sb)
2127 {
2128 	return (EXT4_SB(sb)->s_es->s_feature_incompat != 0);
2129 }
2130 
2131 /*
2132  * Superblock flags
2133  */
2134 #define EXT4_FLAGS_RESIZING	0
2135 #define EXT4_FLAGS_SHUTDOWN	1
2136 #define EXT4_FLAGS_BDEV_IS_DAX	2
2137 
2138 static inline int ext4_forced_shutdown(struct ext4_sb_info *sbi)
2139 {
2140 	return test_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);
2141 }
2142 
2143 
2144 /*
2145  * Default values for user and/or group using reserved blocks
2146  */
2147 #define	EXT4_DEF_RESUID		0
2148 #define	EXT4_DEF_RESGID		0
2149 
2150 /*
2151  * Default project ID
2152  */
2153 #define	EXT4_DEF_PROJID		0
2154 
2155 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
2156 
2157 /*
2158  * Default mount options
2159  */
2160 #define EXT4_DEFM_DEBUG		0x0001
2161 #define EXT4_DEFM_BSDGROUPS	0x0002
2162 #define EXT4_DEFM_XATTR_USER	0x0004
2163 #define EXT4_DEFM_ACL		0x0008
2164 #define EXT4_DEFM_UID16		0x0010
2165 #define EXT4_DEFM_JMODE		0x0060
2166 #define EXT4_DEFM_JMODE_DATA	0x0020
2167 #define EXT4_DEFM_JMODE_ORDERED	0x0040
2168 #define EXT4_DEFM_JMODE_WBACK	0x0060
2169 #define EXT4_DEFM_NOBARRIER	0x0100
2170 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
2171 #define EXT4_DEFM_DISCARD	0x0400
2172 #define EXT4_DEFM_NODELALLOC	0x0800
2173 
2174 /*
2175  * Default journal batch times
2176  */
2177 #define EXT4_DEF_MIN_BATCH_TIME	0
2178 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
2179 
2180 /*
2181  * Minimum number of groups in a flexgroup before we separate out
2182  * directories into the first block group of a flexgroup
2183  */
2184 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
2185 
2186 /*
2187  * Structure of a directory entry
2188  */
2189 #define EXT4_NAME_LEN 255
2190 
2191 struct ext4_dir_entry {
2192 	__le32	inode;			/* Inode number */
2193 	__le16	rec_len;		/* Directory entry length */
2194 	__le16	name_len;		/* Name length */
2195 	char	name[EXT4_NAME_LEN];	/* File name */
2196 };
2197 
2198 /*
2199  * The new version of the directory entry.  Since EXT4 structures are
2200  * stored in intel byte order, and the name_len field could never be
2201  * bigger than 255 chars, it's safe to reclaim the extra byte for the
2202  * file_type field.
2203  */
2204 struct ext4_dir_entry_2 {
2205 	__le32	inode;			/* Inode number */
2206 	__le16	rec_len;		/* Directory entry length */
2207 	__u8	name_len;		/* Name length */
2208 	__u8	file_type;		/* See file type macros EXT4_FT_* below */
2209 	char	name[EXT4_NAME_LEN];	/* File name */
2210 };
2211 
2212 /*
2213  * This is a bogus directory entry at the end of each leaf block that
2214  * records checksums.
2215  */
2216 struct ext4_dir_entry_tail {
2217 	__le32	det_reserved_zero1;	/* Pretend to be unused */
2218 	__le16	det_rec_len;		/* 12 */
2219 	__u8	det_reserved_zero2;	/* Zero name length */
2220 	__u8	det_reserved_ft;	/* 0xDE, fake file type */
2221 	__le32	det_checksum;		/* crc32c(uuid+inum+dirblock) */
2222 };
2223 
2224 #define EXT4_DIRENT_TAIL(block, blocksize) \
2225 	((struct ext4_dir_entry_tail *)(((void *)(block)) + \
2226 					((blocksize) - \
2227 					 sizeof(struct ext4_dir_entry_tail))))
2228 
2229 /*
2230  * Ext4 directory file types.  Only the low 3 bits are used.  The
2231  * other bits are reserved for now.
2232  */
2233 #define EXT4_FT_UNKNOWN		0
2234 #define EXT4_FT_REG_FILE	1
2235 #define EXT4_FT_DIR		2
2236 #define EXT4_FT_CHRDEV		3
2237 #define EXT4_FT_BLKDEV		4
2238 #define EXT4_FT_FIFO		5
2239 #define EXT4_FT_SOCK		6
2240 #define EXT4_FT_SYMLINK		7
2241 
2242 #define EXT4_FT_MAX		8
2243 
2244 #define EXT4_FT_DIR_CSUM	0xDE
2245 
2246 /*
2247  * EXT4_DIR_PAD defines the directory entries boundaries
2248  *
2249  * NOTE: It must be a multiple of 4
2250  */
2251 #define EXT4_DIR_PAD			4
2252 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
2253 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
2254 					 ~EXT4_DIR_ROUND)
2255 #define EXT4_MAX_REC_LEN		((1<<16)-1)
2256 
2257 /*
2258  * If we ever get support for fs block sizes > page_size, we'll need
2259  * to remove the #if statements in the next two functions...
2260  */
2261 static inline unsigned int
2262 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
2263 {
2264 	unsigned len = le16_to_cpu(dlen);
2265 
2266 #if (PAGE_SIZE >= 65536)
2267 	if (len == EXT4_MAX_REC_LEN || len == 0)
2268 		return blocksize;
2269 	return (len & 65532) | ((len & 3) << 16);
2270 #else
2271 	return len;
2272 #endif
2273 }
2274 
2275 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
2276 {
2277 	if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
2278 		BUG();
2279 #if (PAGE_SIZE >= 65536)
2280 	if (len < 65536)
2281 		return cpu_to_le16(len);
2282 	if (len == blocksize) {
2283 		if (blocksize == 65536)
2284 			return cpu_to_le16(EXT4_MAX_REC_LEN);
2285 		else
2286 			return cpu_to_le16(0);
2287 	}
2288 	return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
2289 #else
2290 	return cpu_to_le16(len);
2291 #endif
2292 }
2293 
2294 /*
2295  * Hash Tree Directory indexing
2296  * (c) Daniel Phillips, 2001
2297  */
2298 
2299 #define is_dx(dir) (ext4_has_feature_dir_index((dir)->i_sb) && \
2300 		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
2301 #define EXT4_DIR_LINK_MAX(dir) unlikely((dir)->i_nlink >= EXT4_LINK_MAX && \
2302 		    !(ext4_has_feature_dir_nlink((dir)->i_sb) && is_dx(dir)))
2303 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
2304 
2305 /* Legal values for the dx_root hash_version field: */
2306 
2307 #define DX_HASH_LEGACY			0
2308 #define DX_HASH_HALF_MD4		1
2309 #define DX_HASH_TEA			2
2310 #define DX_HASH_LEGACY_UNSIGNED		3
2311 #define DX_HASH_HALF_MD4_UNSIGNED	4
2312 #define DX_HASH_TEA_UNSIGNED		5
2313 
2314 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
2315 			      const void *address, unsigned int length)
2316 {
2317 	struct {
2318 		struct shash_desc shash;
2319 		char ctx[4];
2320 	} desc;
2321 
2322 	BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
2323 
2324 	desc.shash.tfm = sbi->s_chksum_driver;
2325 	*(u32 *)desc.ctx = crc;
2326 
2327 	BUG_ON(crypto_shash_update(&desc.shash, address, length));
2328 
2329 	return *(u32 *)desc.ctx;
2330 }
2331 
2332 #ifdef __KERNEL__
2333 
2334 /* hash info structure used by the directory hash */
2335 struct dx_hash_info
2336 {
2337 	u32		hash;
2338 	u32		minor_hash;
2339 	int		hash_version;
2340 	u32		*seed;
2341 };
2342 
2343 
2344 /* 32 and 64 bit signed EOF for dx directories */
2345 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
2346 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
2347 
2348 
2349 /*
2350  * Control parameters used by ext4_htree_next_block
2351  */
2352 #define HASH_NB_ALWAYS		1
2353 
2354 struct ext4_filename {
2355 	const struct qstr *usr_fname;
2356 	struct fscrypt_str disk_name;
2357 	struct dx_hash_info hinfo;
2358 #ifdef CONFIG_FS_ENCRYPTION
2359 	struct fscrypt_str crypto_buf;
2360 #endif
2361 #ifdef CONFIG_UNICODE
2362 	struct fscrypt_str cf_name;
2363 #endif
2364 };
2365 
2366 #define fname_name(p) ((p)->disk_name.name)
2367 #define fname_len(p)  ((p)->disk_name.len)
2368 
2369 /*
2370  * Describe an inode's exact location on disk and in memory
2371  */
2372 struct ext4_iloc
2373 {
2374 	struct buffer_head *bh;
2375 	unsigned long offset;
2376 	ext4_group_t block_group;
2377 };
2378 
2379 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
2380 {
2381 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
2382 }
2383 
2384 static inline bool ext4_is_quota_file(struct inode *inode)
2385 {
2386 	return IS_NOQUOTA(inode) &&
2387 	       !(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL);
2388 }
2389 
2390 /*
2391  * This structure is stuffed into the struct file's private_data field
2392  * for directories.  It is where we put information so that we can do
2393  * readdir operations in hash tree order.
2394  */
2395 struct dir_private_info {
2396 	struct rb_root	root;
2397 	struct rb_node	*curr_node;
2398 	struct fname	*extra_fname;
2399 	loff_t		last_pos;
2400 	__u32		curr_hash;
2401 	__u32		curr_minor_hash;
2402 	__u32		next_hash;
2403 };
2404 
2405 /* calculate the first block number of the group */
2406 static inline ext4_fsblk_t
2407 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
2408 {
2409 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
2410 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
2411 }
2412 
2413 /*
2414  * Special error return code only used by dx_probe() and its callers.
2415  */
2416 #define ERR_BAD_DX_DIR	(-(MAX_ERRNO - 1))
2417 
2418 /* htree levels for ext4 */
2419 #define	EXT4_HTREE_LEVEL_COMPAT	2
2420 #define	EXT4_HTREE_LEVEL	3
2421 
2422 static inline int ext4_dir_htree_level(struct super_block *sb)
2423 {
2424 	return ext4_has_feature_largedir(sb) ?
2425 		EXT4_HTREE_LEVEL : EXT4_HTREE_LEVEL_COMPAT;
2426 }
2427 
2428 /*
2429  * Timeout and state flag for lazy initialization inode thread.
2430  */
2431 #define EXT4_DEF_LI_WAIT_MULT			10
2432 #define EXT4_DEF_LI_MAX_START_DELAY		5
2433 #define EXT4_LAZYINIT_QUIT			0x0001
2434 #define EXT4_LAZYINIT_RUNNING			0x0002
2435 
2436 /*
2437  * Lazy inode table initialization info
2438  */
2439 struct ext4_lazy_init {
2440 	unsigned long		li_state;
2441 	struct list_head	li_request_list;
2442 	struct mutex		li_list_mtx;
2443 };
2444 
2445 enum ext4_li_mode {
2446 	EXT4_LI_MODE_PREFETCH_BBITMAP,
2447 	EXT4_LI_MODE_ITABLE,
2448 };
2449 
2450 struct ext4_li_request {
2451 	struct super_block	*lr_super;
2452 	enum ext4_li_mode	lr_mode;
2453 	ext4_group_t		lr_first_not_zeroed;
2454 	ext4_group_t		lr_next_group;
2455 	struct list_head	lr_request;
2456 	unsigned long		lr_next_sched;
2457 	unsigned long		lr_timeout;
2458 };
2459 
2460 struct ext4_features {
2461 	struct kobject f_kobj;
2462 	struct completion f_kobj_unregister;
2463 };
2464 
2465 /*
2466  * This structure will be used for multiple mount protection. It will be
2467  * written into the block number saved in the s_mmp_block field in the
2468  * superblock. Programs that check MMP should assume that if
2469  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
2470  * to use the filesystem, regardless of how old the timestamp is.
2471  */
2472 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
2473 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
2474 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
2475 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
2476 
2477 struct mmp_struct {
2478 	__le32	mmp_magic;		/* Magic number for MMP */
2479 	__le32	mmp_seq;		/* Sequence no. updated periodically */
2480 
2481 	/*
2482 	 * mmp_time, mmp_nodename & mmp_bdevname are only used for information
2483 	 * purposes and do not affect the correctness of the algorithm
2484 	 */
2485 	__le64	mmp_time;		/* Time last updated */
2486 	char	mmp_nodename[64];	/* Node which last updated MMP block */
2487 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
2488 
2489 	/*
2490 	 * mmp_check_interval is used to verify if the MMP block has been
2491 	 * updated on the block device. The value is updated based on the
2492 	 * maximum time to write the MMP block during an update cycle.
2493 	 */
2494 	__le16	mmp_check_interval;
2495 
2496 	__le16	mmp_pad1;
2497 	__le32	mmp_pad2[226];
2498 	__le32	mmp_checksum;		/* crc32c(uuid+mmp_block) */
2499 };
2500 
2501 /* arguments passed to the mmp thread */
2502 struct mmpd_data {
2503 	struct buffer_head *bh; /* bh from initial read_mmp_block() */
2504 	struct super_block *sb;  /* super block of the fs */
2505 };
2506 
2507 /*
2508  * Check interval multiplier
2509  * The MMP block is written every update interval and initially checked every
2510  * update interval x the multiplier (the value is then adapted based on the
2511  * write latency). The reason is that writes can be delayed under load and we
2512  * don't want readers to incorrectly assume that the filesystem is no longer
2513  * in use.
2514  */
2515 #define EXT4_MMP_CHECK_MULT		2UL
2516 
2517 /*
2518  * Minimum interval for MMP checking in seconds.
2519  */
2520 #define EXT4_MMP_MIN_CHECK_INTERVAL	5UL
2521 
2522 /*
2523  * Maximum interval for MMP checking in seconds.
2524  */
2525 #define EXT4_MMP_MAX_CHECK_INTERVAL	300UL
2526 
2527 /*
2528  * Function prototypes
2529  */
2530 
2531 /*
2532  * Ok, these declarations are also in <linux/kernel.h> but none of the
2533  * ext4 source programs needs to include it so they are duplicated here.
2534  */
2535 # define NORET_TYPE	/**/
2536 # define ATTRIB_NORET	__attribute__((noreturn))
2537 # define NORET_AND	noreturn,
2538 
2539 /* bitmap.c */
2540 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
2541 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
2542 				struct ext4_group_desc *gdp,
2543 				struct buffer_head *bh, int sz);
2544 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
2545 				  struct ext4_group_desc *gdp,
2546 				  struct buffer_head *bh, int sz);
2547 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
2548 				struct ext4_group_desc *gdp,
2549 				struct buffer_head *bh);
2550 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
2551 				  struct ext4_group_desc *gdp,
2552 				  struct buffer_head *bh);
2553 
2554 /* balloc.c */
2555 extern void ext4_get_group_no_and_offset(struct super_block *sb,
2556 					 ext4_fsblk_t blocknr,
2557 					 ext4_group_t *blockgrpp,
2558 					 ext4_grpblk_t *offsetp);
2559 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
2560 					  ext4_fsblk_t block);
2561 
2562 extern unsigned int ext4_block_group(struct super_block *sb,
2563 			ext4_fsblk_t blocknr);
2564 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
2565 			ext4_fsblk_t blocknr);
2566 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
2567 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
2568 			ext4_group_t group);
2569 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
2570 					 ext4_fsblk_t goal,
2571 					 unsigned int flags,
2572 					 unsigned long *count,
2573 					 int *errp);
2574 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
2575 				    s64 nclusters, unsigned int flags);
2576 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
2577 extern void ext4_check_blocks_bitmap(struct super_block *);
2578 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
2579 						    ext4_group_t block_group,
2580 						    struct buffer_head ** bh);
2581 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
2582 
2583 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
2584 						ext4_group_t block_group,
2585 						bool ignore_locked);
2586 extern int ext4_wait_block_bitmap(struct super_block *sb,
2587 				  ext4_group_t block_group,
2588 				  struct buffer_head *bh);
2589 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
2590 						  ext4_group_t block_group);
2591 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
2592 					      ext4_group_t block_group,
2593 					      struct ext4_group_desc *gdp);
2594 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
2595 
2596 #ifdef CONFIG_UNICODE
2597 extern void ext4_fname_setup_ci_filename(struct inode *dir,
2598 					 const struct qstr *iname,
2599 					 struct fscrypt_str *fname);
2600 #endif
2601 
2602 #ifdef CONFIG_FS_ENCRYPTION
2603 static inline void ext4_fname_from_fscrypt_name(struct ext4_filename *dst,
2604 						const struct fscrypt_name *src)
2605 {
2606 	memset(dst, 0, sizeof(*dst));
2607 
2608 	dst->usr_fname = src->usr_fname;
2609 	dst->disk_name = src->disk_name;
2610 	dst->hinfo.hash = src->hash;
2611 	dst->hinfo.minor_hash = src->minor_hash;
2612 	dst->crypto_buf = src->crypto_buf;
2613 }
2614 
2615 static inline int ext4_fname_setup_filename(struct inode *dir,
2616 					    const struct qstr *iname,
2617 					    int lookup,
2618 					    struct ext4_filename *fname)
2619 {
2620 	struct fscrypt_name name;
2621 	int err;
2622 
2623 	err = fscrypt_setup_filename(dir, iname, lookup, &name);
2624 	if (err)
2625 		return err;
2626 
2627 	ext4_fname_from_fscrypt_name(fname, &name);
2628 
2629 #ifdef CONFIG_UNICODE
2630 	ext4_fname_setup_ci_filename(dir, iname, &fname->cf_name);
2631 #endif
2632 	return 0;
2633 }
2634 
2635 static inline int ext4_fname_prepare_lookup(struct inode *dir,
2636 					    struct dentry *dentry,
2637 					    struct ext4_filename *fname)
2638 {
2639 	struct fscrypt_name name;
2640 	int err;
2641 
2642 	err = fscrypt_prepare_lookup(dir, dentry, &name);
2643 	if (err)
2644 		return err;
2645 
2646 	ext4_fname_from_fscrypt_name(fname, &name);
2647 
2648 #ifdef CONFIG_UNICODE
2649 	ext4_fname_setup_ci_filename(dir, &dentry->d_name, &fname->cf_name);
2650 #endif
2651 	return 0;
2652 }
2653 
2654 static inline void ext4_fname_free_filename(struct ext4_filename *fname)
2655 {
2656 	struct fscrypt_name name;
2657 
2658 	name.crypto_buf = fname->crypto_buf;
2659 	fscrypt_free_filename(&name);
2660 
2661 	fname->crypto_buf.name = NULL;
2662 	fname->usr_fname = NULL;
2663 	fname->disk_name.name = NULL;
2664 
2665 #ifdef CONFIG_UNICODE
2666 	kfree(fname->cf_name.name);
2667 	fname->cf_name.name = NULL;
2668 #endif
2669 }
2670 #else /* !CONFIG_FS_ENCRYPTION */
2671 static inline int ext4_fname_setup_filename(struct inode *dir,
2672 					    const struct qstr *iname,
2673 					    int lookup,
2674 					    struct ext4_filename *fname)
2675 {
2676 	fname->usr_fname = iname;
2677 	fname->disk_name.name = (unsigned char *) iname->name;
2678 	fname->disk_name.len = iname->len;
2679 
2680 #ifdef CONFIG_UNICODE
2681 	ext4_fname_setup_ci_filename(dir, iname, &fname->cf_name);
2682 #endif
2683 
2684 	return 0;
2685 }
2686 
2687 static inline int ext4_fname_prepare_lookup(struct inode *dir,
2688 					    struct dentry *dentry,
2689 					    struct ext4_filename *fname)
2690 {
2691 	return ext4_fname_setup_filename(dir, &dentry->d_name, 1, fname);
2692 }
2693 
2694 static inline void ext4_fname_free_filename(struct ext4_filename *fname)
2695 {
2696 #ifdef CONFIG_UNICODE
2697 	kfree(fname->cf_name.name);
2698 	fname->cf_name.name = NULL;
2699 #endif
2700 }
2701 #endif /* !CONFIG_FS_ENCRYPTION */
2702 
2703 /* dir.c */
2704 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
2705 				  struct file *,
2706 				  struct ext4_dir_entry_2 *,
2707 				  struct buffer_head *, char *, int,
2708 				  unsigned int);
2709 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)	\
2710 	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
2711 					(de), (bh), (buf), (size), (offset)))
2712 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
2713 				__u32 minor_hash,
2714 				struct ext4_dir_entry_2 *dirent,
2715 				struct fscrypt_str *ent_name);
2716 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
2717 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
2718 			     struct buffer_head *bh,
2719 			     void *buf, int buf_size,
2720 			     struct ext4_filename *fname,
2721 			     struct ext4_dir_entry_2 **dest_de);
2722 void ext4_insert_dentry(struct inode *inode,
2723 			struct ext4_dir_entry_2 *de,
2724 			int buf_size,
2725 			struct ext4_filename *fname);
2726 static inline void ext4_update_dx_flag(struct inode *inode)
2727 {
2728 	if (!ext4_has_feature_dir_index(inode->i_sb) &&
2729 	    ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) {
2730 		/* ext4_iget() should have caught this... */
2731 		WARN_ON_ONCE(ext4_has_feature_metadata_csum(inode->i_sb));
2732 		ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
2733 	}
2734 }
2735 static const unsigned char ext4_filetype_table[] = {
2736 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
2737 };
2738 
2739 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
2740 {
2741 	if (!ext4_has_feature_filetype(sb) || filetype >= EXT4_FT_MAX)
2742 		return DT_UNKNOWN;
2743 
2744 	return ext4_filetype_table[filetype];
2745 }
2746 extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
2747 			     void *buf, int buf_size);
2748 
2749 /* fsync.c */
2750 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2751 
2752 /* hash.c */
2753 extern int ext4fs_dirhash(const struct inode *dir, const char *name, int len,
2754 			  struct dx_hash_info *hinfo);
2755 
2756 /* ialloc.c */
2757 extern int ext4_mark_inode_used(struct super_block *sb, int ino);
2758 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
2759 				      const struct qstr *qstr, __u32 goal,
2760 				      uid_t *owner, __u32 i_flags,
2761 				      int handle_type, unsigned int line_no,
2762 				      int nblocks);
2763 
2764 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner, i_flags) \
2765 	__ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
2766 			 i_flags, 0, 0, 0)
2767 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
2768 				    type, nblocks)		    \
2769 	__ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
2770 			 0, (type), __LINE__, (nblocks))
2771 
2772 
2773 extern void ext4_free_inode(handle_t *, struct inode *);
2774 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2775 extern unsigned long ext4_count_free_inodes(struct super_block *);
2776 extern unsigned long ext4_count_dirs(struct super_block *);
2777 extern void ext4_check_inodes_bitmap(struct super_block *);
2778 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2779 extern int ext4_init_inode_table(struct super_block *sb,
2780 				 ext4_group_t group, int barrier);
2781 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2782 
2783 /* fast_commit.c */
2784 int ext4_fc_info_show(struct seq_file *seq, void *v);
2785 void ext4_fc_init(struct super_block *sb, journal_t *journal);
2786 void ext4_fc_init_inode(struct inode *inode);
2787 void ext4_fc_track_range(handle_t *handle, struct inode *inode, ext4_lblk_t start,
2788 			 ext4_lblk_t end);
2789 void __ext4_fc_track_unlink(handle_t *handle, struct inode *inode,
2790 	struct dentry *dentry);
2791 void __ext4_fc_track_link(handle_t *handle, struct inode *inode,
2792 	struct dentry *dentry);
2793 void ext4_fc_track_unlink(handle_t *handle, struct dentry *dentry);
2794 void ext4_fc_track_link(handle_t *handle, struct dentry *dentry);
2795 void ext4_fc_track_create(handle_t *handle, struct dentry *dentry);
2796 void ext4_fc_track_inode(handle_t *handle, struct inode *inode);
2797 void ext4_fc_mark_ineligible(struct super_block *sb, int reason);
2798 void ext4_fc_start_ineligible(struct super_block *sb, int reason);
2799 void ext4_fc_stop_ineligible(struct super_block *sb);
2800 void ext4_fc_start_update(struct inode *inode);
2801 void ext4_fc_stop_update(struct inode *inode);
2802 void ext4_fc_del(struct inode *inode);
2803 bool ext4_fc_replay_check_excluded(struct super_block *sb, ext4_fsblk_t block);
2804 void ext4_fc_replay_cleanup(struct super_block *sb);
2805 int ext4_fc_commit(journal_t *journal, tid_t commit_tid);
2806 int __init ext4_fc_init_dentry_cache(void);
2807 
2808 /* mballoc.c */
2809 extern const struct seq_operations ext4_mb_seq_groups_ops;
2810 extern long ext4_mb_stats;
2811 extern long ext4_mb_max_to_scan;
2812 extern int ext4_mb_init(struct super_block *);
2813 extern int ext4_mb_release(struct super_block *);
2814 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2815 				struct ext4_allocation_request *, int *);
2816 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2817 extern void ext4_discard_preallocations(struct inode *, unsigned int);
2818 extern int __init ext4_init_mballoc(void);
2819 extern void ext4_exit_mballoc(void);
2820 extern ext4_group_t ext4_mb_prefetch(struct super_block *sb,
2821 				     ext4_group_t group,
2822 				     unsigned int nr, int *cnt);
2823 extern void ext4_mb_prefetch_fini(struct super_block *sb, ext4_group_t group,
2824 				  unsigned int nr);
2825 
2826 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2827 			     struct buffer_head *bh, ext4_fsblk_t block,
2828 			     unsigned long count, int flags);
2829 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2830 				   ext4_group_t ngroups);
2831 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2832 		ext4_group_t i, struct ext4_group_desc *desc);
2833 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2834 				ext4_fsblk_t block, unsigned long count);
2835 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2836 extern void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid);
2837 extern void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
2838 		       int len, int state);
2839 
2840 /* inode.c */
2841 void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw,
2842 			 struct ext4_inode_info *ei);
2843 int ext4_inode_is_fast_symlink(struct inode *inode);
2844 struct buffer_head *ext4_getblk(handle_t *, struct inode *, ext4_lblk_t, int);
2845 struct buffer_head *ext4_bread(handle_t *, struct inode *, ext4_lblk_t, int);
2846 int ext4_bread_batch(struct inode *inode, ext4_lblk_t block, int bh_count,
2847 		     bool wait, struct buffer_head **bhs);
2848 int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
2849 			     struct buffer_head *bh_result, int create);
2850 int ext4_get_block(struct inode *inode, sector_t iblock,
2851 		   struct buffer_head *bh_result, int create);
2852 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2853 			   struct buffer_head *bh, int create);
2854 int ext4_walk_page_buffers(handle_t *handle,
2855 			   struct buffer_head *head,
2856 			   unsigned from,
2857 			   unsigned to,
2858 			   int *partial,
2859 			   int (*fn)(handle_t *handle,
2860 				     struct buffer_head *bh));
2861 int do_journal_get_write_access(handle_t *handle,
2862 				struct buffer_head *bh);
2863 #define FALL_BACK_TO_NONDELALLOC 1
2864 #define CONVERT_INLINE_DATA	 2
2865 
2866 typedef enum {
2867 	EXT4_IGET_NORMAL =	0,
2868 	EXT4_IGET_SPECIAL =	0x0001, /* OK to iget a system inode */
2869 	EXT4_IGET_HANDLE = 	0x0002	/* Inode # is from a handle */
2870 } ext4_iget_flags;
2871 
2872 extern struct inode *__ext4_iget(struct super_block *sb, unsigned long ino,
2873 				 ext4_iget_flags flags, const char *function,
2874 				 unsigned int line);
2875 
2876 #define ext4_iget(sb, ino, flags) \
2877 	__ext4_iget((sb), (ino), (flags), __func__, __LINE__)
2878 
2879 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2880 extern int  ext4_setattr(struct dentry *, struct iattr *);
2881 extern int  ext4_getattr(const struct path *, struct kstat *, u32, unsigned int);
2882 extern void ext4_evict_inode(struct inode *);
2883 extern void ext4_clear_inode(struct inode *);
2884 extern int  ext4_file_getattr(const struct path *, struct kstat *, u32, unsigned int);
2885 extern int  ext4_sync_inode(handle_t *, struct inode *);
2886 extern void ext4_dirty_inode(struct inode *, int);
2887 extern int ext4_change_inode_journal_flag(struct inode *, int);
2888 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2889 extern int ext4_get_fc_inode_loc(struct super_block *sb, unsigned long ino,
2890 			  struct ext4_iloc *iloc);
2891 extern int ext4_inode_attach_jinode(struct inode *inode);
2892 extern int ext4_can_truncate(struct inode *inode);
2893 extern int ext4_truncate(struct inode *);
2894 extern int ext4_break_layouts(struct inode *);
2895 extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length);
2896 extern void ext4_set_inode_flags(struct inode *, bool init);
2897 extern int ext4_alloc_da_blocks(struct inode *inode);
2898 extern void ext4_set_aops(struct inode *inode);
2899 extern int ext4_writepage_trans_blocks(struct inode *);
2900 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2901 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
2902 			     loff_t lstart, loff_t lend);
2903 extern vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf);
2904 extern vm_fault_t ext4_filemap_fault(struct vm_fault *vmf);
2905 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2906 extern int ext4_get_projid(struct inode *inode, kprojid_t *projid);
2907 extern void ext4_da_release_space(struct inode *inode, int to_free);
2908 extern void ext4_da_update_reserve_space(struct inode *inode,
2909 					int used, int quota_claim);
2910 extern int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk,
2911 			      ext4_fsblk_t pblk, ext4_lblk_t len);
2912 
2913 /* indirect.c */
2914 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2915 				struct ext4_map_blocks *map, int flags);
2916 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2917 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2918 extern int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
2919 				 ext4_lblk_t start, ext4_lblk_t end);
2920 
2921 /* ioctl.c */
2922 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2923 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2924 extern void ext4_reset_inode_seed(struct inode *inode);
2925 
2926 /* migrate.c */
2927 extern int ext4_ext_migrate(struct inode *);
2928 extern int ext4_ind_migrate(struct inode *inode);
2929 
2930 /* namei.c */
2931 extern int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2932 			     struct inode *inode);
2933 extern int ext4_dirblock_csum_verify(struct inode *inode,
2934 				     struct buffer_head *bh);
2935 extern int ext4_orphan_add(handle_t *, struct inode *);
2936 extern int ext4_orphan_del(handle_t *, struct inode *);
2937 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2938 				__u32 start_minor_hash, __u32 *next_hash);
2939 extern int ext4_search_dir(struct buffer_head *bh,
2940 			   char *search_buf,
2941 			   int buf_size,
2942 			   struct inode *dir,
2943 			   struct ext4_filename *fname,
2944 			   unsigned int offset,
2945 			   struct ext4_dir_entry_2 **res_dir);
2946 extern int ext4_generic_delete_entry(struct inode *dir,
2947 				     struct ext4_dir_entry_2 *de_del,
2948 				     struct buffer_head *bh,
2949 				     void *entry_buf,
2950 				     int buf_size,
2951 				     int csum_size);
2952 extern bool ext4_empty_dir(struct inode *inode);
2953 
2954 /* resize.c */
2955 extern void ext4_kvfree_array_rcu(void *to_free);
2956 extern int ext4_group_add(struct super_block *sb,
2957 				struct ext4_new_group_data *input);
2958 extern int ext4_group_extend(struct super_block *sb,
2959 				struct ext4_super_block *es,
2960 				ext4_fsblk_t n_blocks_count);
2961 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2962 
2963 /* super.c */
2964 extern struct buffer_head *ext4_sb_bread(struct super_block *sb,
2965 					 sector_t block, int op_flags);
2966 extern struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
2967 						   sector_t block);
2968 extern void ext4_read_bh_nowait(struct buffer_head *bh, int op_flags,
2969 				bh_end_io_t *end_io);
2970 extern int ext4_read_bh(struct buffer_head *bh, int op_flags,
2971 			bh_end_io_t *end_io);
2972 extern int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait);
2973 extern void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block);
2974 extern int ext4_seq_options_show(struct seq_file *seq, void *offset);
2975 extern int ext4_calculate_overhead(struct super_block *sb);
2976 extern void ext4_superblock_csum_set(struct super_block *sb);
2977 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2978 				    ext4_group_t ngroup);
2979 extern const char *ext4_decode_error(struct super_block *sb, int errno,
2980 				     char nbuf[16]);
2981 extern void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
2982 					     ext4_group_t block_group,
2983 					     unsigned int flags);
2984 
2985 extern __printf(7, 8)
2986 void __ext4_error(struct super_block *, const char *, unsigned int, bool,
2987 		  int, __u64, const char *, ...);
2988 extern __printf(6, 7)
2989 void __ext4_error_inode(struct inode *, const char *, unsigned int,
2990 			ext4_fsblk_t, int, const char *, ...);
2991 extern __printf(5, 6)
2992 void __ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2993 		     const char *, ...);
2994 extern void __ext4_std_error(struct super_block *, const char *,
2995 			     unsigned int, int);
2996 extern __printf(4, 5)
2997 void __ext4_warning(struct super_block *, const char *, unsigned int,
2998 		    const char *, ...);
2999 extern __printf(4, 5)
3000 void __ext4_warning_inode(const struct inode *inode, const char *function,
3001 			  unsigned int line, const char *fmt, ...);
3002 extern __printf(3, 4)
3003 void __ext4_msg(struct super_block *, const char *, const char *, ...);
3004 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
3005 			   const char *, unsigned int, const char *);
3006 extern __printf(7, 8)
3007 void __ext4_grp_locked_error(const char *, unsigned int,
3008 			     struct super_block *, ext4_group_t,
3009 			     unsigned long, ext4_fsblk_t,
3010 			     const char *, ...);
3011 
3012 #define EXT4_ERROR_INODE(inode, fmt, a...) \
3013 	ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
3014 
3015 #define EXT4_ERROR_INODE_ERR(inode, err, fmt, a...)			\
3016 	__ext4_error_inode((inode), __func__, __LINE__, 0, (err), (fmt), ## a)
3017 
3018 #define ext4_error_inode_block(inode, block, err, fmt, a...)		\
3019 	__ext4_error_inode((inode), __func__, __LINE__, (block), (err),	\
3020 			   (fmt), ## a)
3021 
3022 #define EXT4_ERROR_FILE(file, block, fmt, a...)				\
3023 	ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
3024 
3025 #define ext4_abort(sb, err, fmt, a...)					\
3026 	__ext4_error((sb), __func__, __LINE__, true, (err), 0, (fmt), ## a)
3027 
3028 #ifdef CONFIG_PRINTK
3029 
3030 #define ext4_error_inode(inode, func, line, block, fmt, ...)		\
3031 	__ext4_error_inode(inode, func, line, block, 0, fmt, ##__VA_ARGS__)
3032 #define ext4_error_inode_err(inode, func, line, block, err, fmt, ...)	\
3033 	__ext4_error_inode((inode), (func), (line), (block), 		\
3034 			   (err), (fmt), ##__VA_ARGS__)
3035 #define ext4_error_file(file, func, line, block, fmt, ...)		\
3036 	__ext4_error_file(file, func, line, block, fmt, ##__VA_ARGS__)
3037 #define ext4_error(sb, fmt, ...)					\
3038 	__ext4_error((sb), __func__, __LINE__, false, 0, 0, (fmt),	\
3039 		##__VA_ARGS__)
3040 #define ext4_error_err(sb, err, fmt, ...)				\
3041 	__ext4_error((sb), __func__, __LINE__, false, (err), 0, (fmt),	\
3042 		##__VA_ARGS__)
3043 #define ext4_warning(sb, fmt, ...)					\
3044 	__ext4_warning(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
3045 #define ext4_warning_inode(inode, fmt, ...)				\
3046 	__ext4_warning_inode(inode, __func__, __LINE__, fmt, ##__VA_ARGS__)
3047 #define ext4_msg(sb, level, fmt, ...)				\
3048 	__ext4_msg(sb, level, fmt, ##__VA_ARGS__)
3049 #define dump_mmp_msg(sb, mmp, msg)					\
3050 	__dump_mmp_msg(sb, mmp, __func__, __LINE__, msg)
3051 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)		\
3052 	__ext4_grp_locked_error(__func__, __LINE__, sb, grp, ino, block, \
3053 				fmt, ##__VA_ARGS__)
3054 
3055 #else
3056 
3057 #define ext4_error_inode(inode, func, line, block, fmt, ...)		\
3058 do {									\
3059 	no_printk(fmt, ##__VA_ARGS__);					\
3060 	__ext4_error_inode(inode, "", 0, block, 0, " ");		\
3061 } while (0)
3062 #define ext4_error_inode_err(inode, func, line, block, err, fmt, ...)	\
3063 do {									\
3064 	no_printk(fmt, ##__VA_ARGS__);					\
3065 	__ext4_error_inode(inode, "", 0, block, err, " ");		\
3066 } while (0)
3067 #define ext4_error_file(file, func, line, block, fmt, ...)		\
3068 do {									\
3069 	no_printk(fmt, ##__VA_ARGS__);					\
3070 	__ext4_error_file(file, "", 0, block, " ");			\
3071 } while (0)
3072 #define ext4_error(sb, fmt, ...)					\
3073 do {									\
3074 	no_printk(fmt, ##__VA_ARGS__);					\
3075 	__ext4_error(sb, "", 0, false, 0, 0, " ");			\
3076 } while (0)
3077 #define ext4_error_err(sb, err, fmt, ...)				\
3078 do {									\
3079 	no_printk(fmt, ##__VA_ARGS__);					\
3080 	__ext4_error(sb, "", 0, false, err, 0, " ");			\
3081 } while (0)
3082 #define ext4_warning(sb, fmt, ...)					\
3083 do {									\
3084 	no_printk(fmt, ##__VA_ARGS__);					\
3085 	__ext4_warning(sb, "", 0, " ");					\
3086 } while (0)
3087 #define ext4_warning_inode(inode, fmt, ...)				\
3088 do {									\
3089 	no_printk(fmt, ##__VA_ARGS__);					\
3090 	__ext4_warning_inode(inode, "", 0, " ");			\
3091 } while (0)
3092 #define ext4_msg(sb, level, fmt, ...)					\
3093 do {									\
3094 	no_printk(fmt, ##__VA_ARGS__);					\
3095 	__ext4_msg(sb, "", " ");					\
3096 } while (0)
3097 #define dump_mmp_msg(sb, mmp, msg)					\
3098 	__dump_mmp_msg(sb, mmp, "", 0, "")
3099 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)		\
3100 do {									\
3101 	no_printk(fmt, ##__VA_ARGS__);				\
3102 	__ext4_grp_locked_error("", 0, sb, grp, ino, block, " ");	\
3103 } while (0)
3104 
3105 #endif
3106 
3107 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
3108 				      struct ext4_group_desc *bg);
3109 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
3110 				      struct ext4_group_desc *bg);
3111 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
3112 				     struct ext4_group_desc *bg);
3113 extern __u32 ext4_free_group_clusters(struct super_block *sb,
3114 				      struct ext4_group_desc *bg);
3115 extern __u32 ext4_free_inodes_count(struct super_block *sb,
3116 				 struct ext4_group_desc *bg);
3117 extern __u32 ext4_used_dirs_count(struct super_block *sb,
3118 				struct ext4_group_desc *bg);
3119 extern __u32 ext4_itable_unused_count(struct super_block *sb,
3120 				   struct ext4_group_desc *bg);
3121 extern void ext4_block_bitmap_set(struct super_block *sb,
3122 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
3123 extern void ext4_inode_bitmap_set(struct super_block *sb,
3124 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
3125 extern void ext4_inode_table_set(struct super_block *sb,
3126 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
3127 extern void ext4_free_group_clusters_set(struct super_block *sb,
3128 					 struct ext4_group_desc *bg,
3129 					 __u32 count);
3130 extern void ext4_free_inodes_set(struct super_block *sb,
3131 				struct ext4_group_desc *bg, __u32 count);
3132 extern void ext4_used_dirs_set(struct super_block *sb,
3133 				struct ext4_group_desc *bg, __u32 count);
3134 extern void ext4_itable_unused_set(struct super_block *sb,
3135 				   struct ext4_group_desc *bg, __u32 count);
3136 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
3137 				       struct ext4_group_desc *gdp);
3138 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
3139 				     struct ext4_group_desc *gdp);
3140 extern int ext4_register_li_request(struct super_block *sb,
3141 				    ext4_group_t first_not_zeroed);
3142 
3143 static inline int ext4_has_metadata_csum(struct super_block *sb)
3144 {
3145 	WARN_ON_ONCE(ext4_has_feature_metadata_csum(sb) &&
3146 		     !EXT4_SB(sb)->s_chksum_driver);
3147 
3148 	return ext4_has_feature_metadata_csum(sb) &&
3149 	       (EXT4_SB(sb)->s_chksum_driver != NULL);
3150 }
3151 
3152 static inline int ext4_has_group_desc_csum(struct super_block *sb)
3153 {
3154 	return ext4_has_feature_gdt_csum(sb) || ext4_has_metadata_csum(sb);
3155 }
3156 
3157 #define ext4_read_incompat_64bit_val(es, name) \
3158 	(((es)->s_feature_incompat & cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT) \
3159 		? (ext4_fsblk_t)le32_to_cpu(es->name##_hi) << 32 : 0) | \
3160 		le32_to_cpu(es->name##_lo))
3161 
3162 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
3163 {
3164 	return ext4_read_incompat_64bit_val(es, s_blocks_count);
3165 }
3166 
3167 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
3168 {
3169 	return ext4_read_incompat_64bit_val(es, s_r_blocks_count);
3170 }
3171 
3172 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
3173 {
3174 	return ext4_read_incompat_64bit_val(es, s_free_blocks_count);
3175 }
3176 
3177 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
3178 					 ext4_fsblk_t blk)
3179 {
3180 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
3181 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
3182 }
3183 
3184 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
3185 					      ext4_fsblk_t blk)
3186 {
3187 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
3188 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
3189 }
3190 
3191 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
3192 					   ext4_fsblk_t blk)
3193 {
3194 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
3195 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
3196 }
3197 
3198 static inline loff_t ext4_isize(struct super_block *sb,
3199 				struct ext4_inode *raw_inode)
3200 {
3201 	if (ext4_has_feature_largedir(sb) ||
3202 	    S_ISREG(le16_to_cpu(raw_inode->i_mode)))
3203 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
3204 			le32_to_cpu(raw_inode->i_size_lo);
3205 
3206 	return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
3207 }
3208 
3209 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
3210 {
3211 	raw_inode->i_size_lo = cpu_to_le32(i_size);
3212 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
3213 }
3214 
3215 static inline
3216 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
3217 					    ext4_group_t group)
3218 {
3219 	 struct ext4_group_info **grp_info;
3220 	 long indexv, indexh;
3221 	 BUG_ON(group >= EXT4_SB(sb)->s_groups_count);
3222 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
3223 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
3224 	 grp_info = sbi_array_rcu_deref(EXT4_SB(sb), s_group_info, indexv);
3225 	 return grp_info[indexh];
3226 }
3227 
3228 /*
3229  * Reading s_groups_count requires using smp_rmb() afterwards.  See
3230  * the locking protocol documented in the comments of ext4_group_add()
3231  * in resize.c
3232  */
3233 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
3234 {
3235 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
3236 
3237 	smp_rmb();
3238 	return ngroups;
3239 }
3240 
3241 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
3242 					     ext4_group_t block_group)
3243 {
3244 	return block_group >> sbi->s_log_groups_per_flex;
3245 }
3246 
3247 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
3248 {
3249 	return 1 << sbi->s_log_groups_per_flex;
3250 }
3251 
3252 #define ext4_std_error(sb, errno)				\
3253 do {								\
3254 	if ((errno))						\
3255 		__ext4_std_error((sb), __func__, __LINE__, (errno));	\
3256 } while (0)
3257 
3258 #ifdef CONFIG_SMP
3259 /* Each CPU can accumulate percpu_counter_batch clusters in their local
3260  * counters. So we need to make sure we have free clusters more
3261  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
3262  */
3263 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
3264 #else
3265 #define EXT4_FREECLUSTERS_WATERMARK 0
3266 #endif
3267 
3268 /* Update i_disksize. Requires i_mutex to avoid races with truncate */
3269 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
3270 {
3271 	WARN_ON_ONCE(S_ISREG(inode->i_mode) &&
3272 		     !inode_is_locked(inode));
3273 	down_write(&EXT4_I(inode)->i_data_sem);
3274 	if (newsize > EXT4_I(inode)->i_disksize)
3275 		WRITE_ONCE(EXT4_I(inode)->i_disksize, newsize);
3276 	up_write(&EXT4_I(inode)->i_data_sem);
3277 }
3278 
3279 /* Update i_size, i_disksize. Requires i_mutex to avoid races with truncate */
3280 static inline int ext4_update_inode_size(struct inode *inode, loff_t newsize)
3281 {
3282 	int changed = 0;
3283 
3284 	if (newsize > inode->i_size) {
3285 		i_size_write(inode, newsize);
3286 		changed = 1;
3287 	}
3288 	if (newsize > EXT4_I(inode)->i_disksize) {
3289 		ext4_update_i_disksize(inode, newsize);
3290 		changed |= 2;
3291 	}
3292 	return changed;
3293 }
3294 
3295 int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset,
3296 				      loff_t len);
3297 
3298 struct ext4_group_info {
3299 	unsigned long   bb_state;
3300 #ifdef AGGRESSIVE_CHECK
3301 	unsigned long	bb_check_counter;
3302 #endif
3303 	struct rb_root  bb_free_root;
3304 	ext4_grpblk_t	bb_first_free;	/* first free block */
3305 	ext4_grpblk_t	bb_free;	/* total free blocks */
3306 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
3307 	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
3308 	struct          list_head bb_prealloc_list;
3309 #ifdef DOUBLE_CHECK
3310 	void            *bb_bitmap;
3311 #endif
3312 	struct rw_semaphore alloc_sem;
3313 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
3314 					 * regions, index is order.
3315 					 * bb_counters[3] = 5 means
3316 					 * 5 free 8-block regions. */
3317 };
3318 
3319 #define EXT4_GROUP_INFO_NEED_INIT_BIT		0
3320 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT		1
3321 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT	2
3322 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT	3
3323 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT		\
3324 	(1 << EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT)
3325 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT		\
3326 	(1 << EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT)
3327 #define EXT4_GROUP_INFO_BBITMAP_READ_BIT	4
3328 
3329 #define EXT4_MB_GRP_NEED_INIT(grp)	\
3330 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
3331 #define EXT4_MB_GRP_BBITMAP_CORRUPT(grp)	\
3332 	(test_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
3333 #define EXT4_MB_GRP_IBITMAP_CORRUPT(grp)	\
3334 	(test_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
3335 
3336 #define EXT4_MB_GRP_WAS_TRIMMED(grp)	\
3337 	(test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
3338 #define EXT4_MB_GRP_SET_TRIMMED(grp)	\
3339 	(set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
3340 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)	\
3341 	(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
3342 #define EXT4_MB_GRP_TEST_AND_SET_READ(grp)	\
3343 	(test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_READ_BIT, &((grp)->bb_state)))
3344 
3345 #define EXT4_MAX_CONTENTION		8
3346 #define EXT4_CONTENTION_THRESHOLD	2
3347 
3348 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
3349 					      ext4_group_t group)
3350 {
3351 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
3352 }
3353 
3354 /*
3355  * Returns true if the filesystem is busy enough that attempts to
3356  * access the block group locks has run into contention.
3357  */
3358 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
3359 {
3360 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
3361 }
3362 
3363 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
3364 {
3365 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
3366 	if (spin_trylock(lock))
3367 		/*
3368 		 * We're able to grab the lock right away, so drop the
3369 		 * lock contention counter.
3370 		 */
3371 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
3372 	else {
3373 		/*
3374 		 * The lock is busy, so bump the contention counter,
3375 		 * and then wait on the spin lock.
3376 		 */
3377 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
3378 				  EXT4_MAX_CONTENTION);
3379 		spin_lock(lock);
3380 	}
3381 }
3382 
3383 static inline void ext4_unlock_group(struct super_block *sb,
3384 					ext4_group_t group)
3385 {
3386 	spin_unlock(ext4_group_lock_ptr(sb, group));
3387 }
3388 
3389 #ifdef CONFIG_QUOTA
3390 static inline bool ext4_quota_capable(struct super_block *sb)
3391 {
3392 	return (test_opt(sb, QUOTA) || ext4_has_feature_quota(sb));
3393 }
3394 
3395 static inline bool ext4_is_quota_journalled(struct super_block *sb)
3396 {
3397 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3398 
3399 	return (ext4_has_feature_quota(sb) ||
3400 		sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]);
3401 }
3402 #endif
3403 
3404 /*
3405  * Block validity checking
3406  */
3407 #define ext4_check_indirect_blockref(inode, bh)				\
3408 	ext4_check_blockref(__func__, __LINE__, inode,			\
3409 			    (__le32 *)(bh)->b_data,			\
3410 			    EXT4_ADDR_PER_BLOCK((inode)->i_sb))
3411 
3412 #define ext4_ind_check_inode(inode)					\
3413 	ext4_check_blockref(__func__, __LINE__, inode,			\
3414 			    EXT4_I(inode)->i_data,			\
3415 			    EXT4_NDIR_BLOCKS)
3416 
3417 /*
3418  * Inodes and files operations
3419  */
3420 
3421 /* dir.c */
3422 extern const struct file_operations ext4_dir_operations;
3423 
3424 /* file.c */
3425 extern const struct inode_operations ext4_file_inode_operations;
3426 extern const struct file_operations ext4_file_operations;
3427 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
3428 
3429 /* inline.c */
3430 extern int ext4_get_max_inline_size(struct inode *inode);
3431 extern int ext4_find_inline_data_nolock(struct inode *inode);
3432 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
3433 				 unsigned int len);
3434 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
3435 
3436 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
3437 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
3438 					 struct inode *inode,
3439 					 loff_t pos, unsigned len,
3440 					 unsigned flags,
3441 					 struct page **pagep);
3442 extern int ext4_write_inline_data_end(struct inode *inode,
3443 				      loff_t pos, unsigned len,
3444 				      unsigned copied,
3445 				      struct page *page);
3446 extern struct buffer_head *
3447 ext4_journalled_write_inline_data(struct inode *inode,
3448 				  unsigned len,
3449 				  struct page *page);
3450 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
3451 					   struct inode *inode,
3452 					   loff_t pos, unsigned len,
3453 					   unsigned flags,
3454 					   struct page **pagep,
3455 					   void **fsdata);
3456 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
3457 					 unsigned len, unsigned copied,
3458 					 struct page *page);
3459 extern int ext4_try_add_inline_entry(handle_t *handle,
3460 				     struct ext4_filename *fname,
3461 				     struct inode *dir, struct inode *inode);
3462 extern int ext4_try_create_inline_dir(handle_t *handle,
3463 				      struct inode *parent,
3464 				      struct inode *inode);
3465 extern int ext4_read_inline_dir(struct file *filp,
3466 				struct dir_context *ctx,
3467 				int *has_inline_data);
3468 extern int ext4_inlinedir_to_tree(struct file *dir_file,
3469 				  struct inode *dir, ext4_lblk_t block,
3470 				  struct dx_hash_info *hinfo,
3471 				  __u32 start_hash, __u32 start_minor_hash,
3472 				  int *has_inline_data);
3473 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
3474 					struct ext4_filename *fname,
3475 					struct ext4_dir_entry_2 **res_dir,
3476 					int *has_inline_data);
3477 extern int ext4_delete_inline_entry(handle_t *handle,
3478 				    struct inode *dir,
3479 				    struct ext4_dir_entry_2 *de_del,
3480 				    struct buffer_head *bh,
3481 				    int *has_inline_data);
3482 extern bool empty_inline_dir(struct inode *dir, int *has_inline_data);
3483 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
3484 					struct ext4_dir_entry_2 **parent_de,
3485 					int *retval);
3486 extern int ext4_inline_data_fiemap(struct inode *inode,
3487 				   struct fiemap_extent_info *fieinfo,
3488 				   int *has_inline, __u64 start, __u64 len);
3489 
3490 struct iomap;
3491 extern int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap);
3492 
3493 extern int ext4_inline_data_truncate(struct inode *inode, int *has_inline);
3494 
3495 extern int ext4_convert_inline_data(struct inode *inode);
3496 
3497 static inline int ext4_has_inline_data(struct inode *inode)
3498 {
3499 	return ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA) &&
3500 	       EXT4_I(inode)->i_inline_off;
3501 }
3502 
3503 /* namei.c */
3504 extern const struct inode_operations ext4_dir_inode_operations;
3505 extern const struct inode_operations ext4_special_inode_operations;
3506 extern struct dentry *ext4_get_parent(struct dentry *child);
3507 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
3508 				 struct ext4_dir_entry_2 *de,
3509 				 int blocksize, int csum_size,
3510 				 unsigned int parent_ino, int dotdot_real_len);
3511 extern void ext4_initialize_dirent_tail(struct buffer_head *bh,
3512 					unsigned int blocksize);
3513 extern int ext4_handle_dirty_dirblock(handle_t *handle, struct inode *inode,
3514 				      struct buffer_head *bh);
3515 extern int ext4_ci_compare(const struct inode *parent,
3516 			   const struct qstr *fname,
3517 			   const struct qstr *entry, bool quick);
3518 extern int __ext4_unlink(handle_t *handle, struct inode *dir, const struct qstr *d_name,
3519 			 struct inode *inode);
3520 extern int __ext4_link(struct inode *dir, struct inode *inode,
3521 		       struct dentry *dentry);
3522 
3523 #define S_SHIFT 12
3524 static const unsigned char ext4_type_by_mode[(S_IFMT >> S_SHIFT) + 1] = {
3525 	[S_IFREG >> S_SHIFT]	= EXT4_FT_REG_FILE,
3526 	[S_IFDIR >> S_SHIFT]	= EXT4_FT_DIR,
3527 	[S_IFCHR >> S_SHIFT]	= EXT4_FT_CHRDEV,
3528 	[S_IFBLK >> S_SHIFT]	= EXT4_FT_BLKDEV,
3529 	[S_IFIFO >> S_SHIFT]	= EXT4_FT_FIFO,
3530 	[S_IFSOCK >> S_SHIFT]	= EXT4_FT_SOCK,
3531 	[S_IFLNK >> S_SHIFT]	= EXT4_FT_SYMLINK,
3532 };
3533 
3534 static inline void ext4_set_de_type(struct super_block *sb,
3535 				struct ext4_dir_entry_2 *de,
3536 				umode_t mode) {
3537 	if (ext4_has_feature_filetype(sb))
3538 		de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
3539 }
3540 
3541 /* readpages.c */
3542 extern int ext4_mpage_readpages(struct inode *inode,
3543 		struct readahead_control *rac, struct page *page);
3544 extern int __init ext4_init_post_read_processing(void);
3545 extern void ext4_exit_post_read_processing(void);
3546 
3547 /* symlink.c */
3548 extern const struct inode_operations ext4_encrypted_symlink_inode_operations;
3549 extern const struct inode_operations ext4_symlink_inode_operations;
3550 extern const struct inode_operations ext4_fast_symlink_inode_operations;
3551 
3552 /* sysfs.c */
3553 extern int ext4_register_sysfs(struct super_block *sb);
3554 extern void ext4_unregister_sysfs(struct super_block *sb);
3555 extern int __init ext4_init_sysfs(void);
3556 extern void ext4_exit_sysfs(void);
3557 
3558 /* block_validity */
3559 extern void ext4_release_system_zone(struct super_block *sb);
3560 extern int ext4_setup_system_zone(struct super_block *sb);
3561 extern int __init ext4_init_system_zone(void);
3562 extern void ext4_exit_system_zone(void);
3563 extern int ext4_inode_block_valid(struct inode *inode,
3564 				  ext4_fsblk_t start_blk,
3565 				  unsigned int count);
3566 extern int ext4_check_blockref(const char *, unsigned int,
3567 			       struct inode *, __le32 *, unsigned int);
3568 
3569 /* extents.c */
3570 struct ext4_ext_path;
3571 struct ext4_extent;
3572 
3573 /*
3574  * Maximum number of logical blocks in a file; ext4_extent's ee_block is
3575  * __le32.
3576  */
3577 #define EXT_MAX_BLOCKS	0xffffffff
3578 
3579 extern void ext4_ext_tree_init(handle_t *handle, struct inode *inode);
3580 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
3581 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
3582 			       struct ext4_map_blocks *map, int flags);
3583 extern int ext4_ext_truncate(handle_t *, struct inode *);
3584 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
3585 				 ext4_lblk_t end);
3586 extern void ext4_ext_init(struct super_block *);
3587 extern void ext4_ext_release(struct super_block *);
3588 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
3589 			  loff_t len);
3590 extern int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
3591 					  loff_t offset, ssize_t len);
3592 extern int ext4_convert_unwritten_io_end_vec(handle_t *handle,
3593 					     ext4_io_end_t *io_end);
3594 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
3595 			   struct ext4_map_blocks *map, int flags);
3596 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
3597 						   int num,
3598 						   struct ext4_ext_path *path);
3599 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
3600 				  struct ext4_ext_path **,
3601 				  struct ext4_extent *, int);
3602 extern struct ext4_ext_path *ext4_find_extent(struct inode *, ext4_lblk_t,
3603 					      struct ext4_ext_path **,
3604 					      int flags);
3605 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
3606 extern int ext4_ext_check_inode(struct inode *inode);
3607 extern ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path);
3608 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3609 			__u64 start, __u64 len);
3610 extern int ext4_get_es_cache(struct inode *inode,
3611 			     struct fiemap_extent_info *fieinfo,
3612 			     __u64 start, __u64 len);
3613 extern int ext4_ext_precache(struct inode *inode);
3614 extern int ext4_swap_extents(handle_t *handle, struct inode *inode1,
3615 				struct inode *inode2, ext4_lblk_t lblk1,
3616 			     ext4_lblk_t lblk2,  ext4_lblk_t count,
3617 			     int mark_unwritten,int *err);
3618 extern int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu);
3619 extern int ext4_datasem_ensure_credits(handle_t *handle, struct inode *inode,
3620 				       int check_cred, int restart_cred,
3621 				       int revoke_cred);
3622 extern void ext4_ext_replay_shrink_inode(struct inode *inode, ext4_lblk_t end);
3623 extern int ext4_ext_replay_set_iblocks(struct inode *inode);
3624 extern int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start,
3625 		int len, int unwritten, ext4_fsblk_t pblk);
3626 extern int ext4_ext_clear_bb(struct inode *inode);
3627 
3628 
3629 /* move_extent.c */
3630 extern void ext4_double_down_write_data_sem(struct inode *first,
3631 					    struct inode *second);
3632 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
3633 					  struct inode *donor_inode);
3634 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
3635 			     __u64 start_orig, __u64 start_donor,
3636 			     __u64 len, __u64 *moved_len);
3637 
3638 /* page-io.c */
3639 extern int __init ext4_init_pageio(void);
3640 extern void ext4_exit_pageio(void);
3641 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
3642 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
3643 extern int ext4_put_io_end(ext4_io_end_t *io_end);
3644 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
3645 extern void ext4_io_submit_init(struct ext4_io_submit *io,
3646 				struct writeback_control *wbc);
3647 extern void ext4_end_io_rsv_work(struct work_struct *work);
3648 extern void ext4_io_submit(struct ext4_io_submit *io);
3649 extern int ext4_bio_write_page(struct ext4_io_submit *io,
3650 			       struct page *page,
3651 			       int len,
3652 			       bool keep_towrite);
3653 extern struct ext4_io_end_vec *ext4_alloc_io_end_vec(ext4_io_end_t *io_end);
3654 extern struct ext4_io_end_vec *ext4_last_io_end_vec(ext4_io_end_t *io_end);
3655 
3656 /* mmp.c */
3657 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
3658 
3659 /* verity.c */
3660 extern const struct fsverity_operations ext4_verityops;
3661 
3662 /*
3663  * Add new method to test whether block and inode bitmaps are properly
3664  * initialized. With uninit_bg reading the block from disk is not enough
3665  * to mark the bitmap uptodate. We need to also zero-out the bitmap
3666  */
3667 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
3668 
3669 static inline int bitmap_uptodate(struct buffer_head *bh)
3670 {
3671 	return (buffer_uptodate(bh) &&
3672 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
3673 }
3674 static inline void set_bitmap_uptodate(struct buffer_head *bh)
3675 {
3676 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
3677 }
3678 
3679 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
3680 
3681 /* For ioend & aio unwritten conversion wait queues */
3682 #define EXT4_WQ_HASH_SZ		37
3683 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
3684 					    EXT4_WQ_HASH_SZ])
3685 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
3686 
3687 extern int ext4_resize_begin(struct super_block *sb);
3688 extern void ext4_resize_end(struct super_block *sb);
3689 
3690 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
3691 					      struct ext4_io_end *io_end)
3692 {
3693 	if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
3694 		io_end->flag |= EXT4_IO_END_UNWRITTEN;
3695 		atomic_inc(&EXT4_I(inode)->i_unwritten);
3696 	}
3697 }
3698 
3699 static inline void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end)
3700 {
3701 	struct inode *inode = io_end->inode;
3702 
3703 	if (io_end->flag & EXT4_IO_END_UNWRITTEN) {
3704 		io_end->flag &= ~EXT4_IO_END_UNWRITTEN;
3705 		/* Wake up anyone waiting on unwritten extent conversion */
3706 		if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten))
3707 			wake_up_all(ext4_ioend_wq(inode));
3708 	}
3709 }
3710 
3711 extern const struct iomap_ops ext4_iomap_ops;
3712 extern const struct iomap_ops ext4_iomap_overwrite_ops;
3713 extern const struct iomap_ops ext4_iomap_report_ops;
3714 
3715 static inline int ext4_buffer_uptodate(struct buffer_head *bh)
3716 {
3717 	/*
3718 	 * If the buffer has the write error flag, we have failed
3719 	 * to write out data in the block.  In this  case, we don't
3720 	 * have to read the block because we may read the old data
3721 	 * successfully.
3722 	 */
3723 	if (!buffer_uptodate(bh) && buffer_write_io_error(bh))
3724 		set_buffer_uptodate(bh);
3725 	return buffer_uptodate(bh);
3726 }
3727 
3728 #endif	/* __KERNEL__ */
3729 
3730 #define EFSBADCRC	EBADMSG		/* Bad CRC detected */
3731 #define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
3732 
3733 #endif	/* _EXT4_H */
3734