xref: /openbmc/linux/fs/ext4/ext4.h (revision 6d99a79c)
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/version.h>
31 #include <linux/wait.h>
32 #include <linux/sched/signal.h>
33 #include <linux/blockgroup_lock.h>
34 #include <linux/percpu_counter.h>
35 #include <linux/ratelimit.h>
36 #include <crypto/hash.h>
37 #include <linux/falloc.h>
38 #include <linux/percpu-rwsem.h>
39 #ifdef __KERNEL__
40 #include <linux/compat.h>
41 #endif
42 
43 #define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_EXT4_FS_ENCRYPTION)
44 #include <linux/fscrypt.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 get lots of info about extents operations.
85  */
86 #define EXT_DEBUG__
87 #ifdef EXT_DEBUG
88 #define ext_debug(fmt, ...)	printk(fmt, ##__VA_ARGS__)
89 #else
90 #define ext_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
91 #endif
92 
93 /* data type for block offset of block group */
94 typedef int ext4_grpblk_t;
95 
96 /* data type for filesystem-wide blocks number */
97 typedef unsigned long long ext4_fsblk_t;
98 
99 /* data type for file logical block number */
100 typedef __u32 ext4_lblk_t;
101 
102 /* data type for block group number */
103 typedef unsigned int ext4_group_t;
104 
105 enum SHIFT_DIRECTION {
106 	SHIFT_LEFT = 0,
107 	SHIFT_RIGHT,
108 };
109 
110 /*
111  * Flags used in mballoc's allocation_context flags field.
112  *
113  * Also used to show what's going on for debugging purposes when the
114  * flag field is exported via the traceport interface
115  */
116 
117 /* prefer goal again. length */
118 #define EXT4_MB_HINT_MERGE		0x0001
119 /* blocks already reserved */
120 #define EXT4_MB_HINT_RESERVED		0x0002
121 /* metadata is being allocated */
122 #define EXT4_MB_HINT_METADATA		0x0004
123 /* first blocks in the file */
124 #define EXT4_MB_HINT_FIRST		0x0008
125 /* search for the best chunk */
126 #define EXT4_MB_HINT_BEST		0x0010
127 /* data is being allocated */
128 #define EXT4_MB_HINT_DATA		0x0020
129 /* don't preallocate (for tails) */
130 #define EXT4_MB_HINT_NOPREALLOC		0x0040
131 /* allocate for locality group */
132 #define EXT4_MB_HINT_GROUP_ALLOC	0x0080
133 /* allocate goal blocks or none */
134 #define EXT4_MB_HINT_GOAL_ONLY		0x0100
135 /* goal is meaningful */
136 #define EXT4_MB_HINT_TRY_GOAL		0x0200
137 /* blocks already pre-reserved by delayed allocation */
138 #define EXT4_MB_DELALLOC_RESERVED	0x0400
139 /* We are doing stream allocation */
140 #define EXT4_MB_STREAM_ALLOC		0x0800
141 /* Use reserved root blocks if needed */
142 #define EXT4_MB_USE_ROOT_BLOCKS		0x1000
143 /* Use blocks from reserved pool */
144 #define EXT4_MB_USE_RESERVED		0x2000
145 
146 struct ext4_allocation_request {
147 	/* target inode for block we're allocating */
148 	struct inode *inode;
149 	/* how many blocks we want to allocate */
150 	unsigned int len;
151 	/* logical block in target inode */
152 	ext4_lblk_t logical;
153 	/* the closest logical allocated block to the left */
154 	ext4_lblk_t lleft;
155 	/* the closest logical allocated block to the right */
156 	ext4_lblk_t lright;
157 	/* phys. target (a hint) */
158 	ext4_fsblk_t goal;
159 	/* phys. block for the closest logical allocated block to the left */
160 	ext4_fsblk_t pleft;
161 	/* phys. block for the closest logical allocated block to the right */
162 	ext4_fsblk_t pright;
163 	/* flags. see above EXT4_MB_HINT_* */
164 	unsigned int flags;
165 };
166 
167 /*
168  * Logical to physical block mapping, used by ext4_map_blocks()
169  *
170  * This structure is used to pass requests into ext4_map_blocks() as
171  * well as to store the information returned by ext4_map_blocks().  It
172  * takes less room on the stack than a struct buffer_head.
173  */
174 #define EXT4_MAP_NEW		(1 << BH_New)
175 #define EXT4_MAP_MAPPED		(1 << BH_Mapped)
176 #define EXT4_MAP_UNWRITTEN	(1 << BH_Unwritten)
177 #define EXT4_MAP_BOUNDARY	(1 << BH_Boundary)
178 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
179 				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY)
180 
181 struct ext4_map_blocks {
182 	ext4_fsblk_t m_pblk;
183 	ext4_lblk_t m_lblk;
184 	unsigned int m_len;
185 	unsigned int m_flags;
186 };
187 
188 /*
189  * Flags for ext4_io_end->flags
190  */
191 #define	EXT4_IO_END_UNWRITTEN	0x0001
192 
193 /*
194  * For converting unwritten extents on a work queue. 'handle' is used for
195  * buffered writeback.
196  */
197 typedef struct ext4_io_end {
198 	struct list_head	list;		/* per-file finished IO list */
199 	handle_t		*handle;	/* handle reserved for extent
200 						 * conversion */
201 	struct inode		*inode;		/* file being written to */
202 	struct bio		*bio;		/* Linked list of completed
203 						 * bios covering the extent */
204 	unsigned int		flag;		/* unwritten or not */
205 	atomic_t		count;		/* reference counter */
206 	loff_t			offset;		/* offset in the file */
207 	ssize_t			size;		/* size of the extent */
208 } ext4_io_end_t;
209 
210 struct ext4_io_submit {
211 	struct writeback_control *io_wbc;
212 	struct bio		*io_bio;
213 	ext4_io_end_t		*io_end;
214 	sector_t		io_next_block;
215 };
216 
217 /*
218  * Special inodes numbers
219  */
220 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
221 #define EXT4_ROOT_INO		 2	/* Root inode */
222 #define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
223 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
224 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
225 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
226 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
227 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
228 
229 /* First non-reserved inode for old ext4 filesystems */
230 #define EXT4_GOOD_OLD_FIRST_INO	11
231 
232 /*
233  * Maximal count of links to a file
234  */
235 #define EXT4_LINK_MAX		65000
236 
237 /*
238  * Macro-instructions used to manage several block sizes
239  */
240 #define EXT4_MIN_BLOCK_SIZE		1024
241 #define	EXT4_MAX_BLOCK_SIZE		65536
242 #define EXT4_MIN_BLOCK_LOG_SIZE		10
243 #define EXT4_MAX_BLOCK_LOG_SIZE		16
244 #define EXT4_MAX_CLUSTER_LOG_SIZE	30
245 #ifdef __KERNEL__
246 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
247 #else
248 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
249 #endif
250 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
251 #define EXT4_CLUSTER_SIZE(s)		(EXT4_BLOCK_SIZE(s) << \
252 					 EXT4_SB(s)->s_cluster_bits)
253 #ifdef __KERNEL__
254 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
255 # define EXT4_CLUSTER_BITS(s)		(EXT4_SB(s)->s_cluster_bits)
256 #else
257 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
258 #endif
259 #ifdef __KERNEL__
260 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
261 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
262 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
263 #else
264 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
265 				 EXT4_GOOD_OLD_INODE_SIZE : \
266 				 (s)->s_inode_size)
267 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
268 				 EXT4_GOOD_OLD_FIRST_INO : \
269 				 (s)->s_first_ino)
270 #endif
271 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
272 #define EXT4_MAX_BLOCKS(size, offset, blkbits) \
273 	((EXT4_BLOCK_ALIGN(size + offset, blkbits) >> blkbits) - (offset >> \
274 								  blkbits))
275 
276 /* Translate a block number to a cluster number */
277 #define EXT4_B2C(sbi, blk)	((blk) >> (sbi)->s_cluster_bits)
278 /* Translate a cluster number to a block number */
279 #define EXT4_C2B(sbi, cluster)	((cluster) << (sbi)->s_cluster_bits)
280 /* Translate # of blks to # of clusters */
281 #define EXT4_NUM_B2C(sbi, blks)	(((blks) + (sbi)->s_cluster_ratio - 1) >> \
282 				 (sbi)->s_cluster_bits)
283 /* Mask out the low bits to get the starting block of the cluster */
284 #define EXT4_PBLK_CMASK(s, pblk) ((pblk) &				\
285 				  ~((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
286 #define EXT4_LBLK_CMASK(s, lblk) ((lblk) &				\
287 				  ~((ext4_lblk_t) (s)->s_cluster_ratio - 1))
288 /* Get the cluster offset */
289 #define EXT4_PBLK_COFF(s, pblk) ((pblk) &				\
290 				 ((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
291 #define EXT4_LBLK_COFF(s, lblk) ((lblk) &				\
292 				 ((ext4_lblk_t) (s)->s_cluster_ratio - 1))
293 
294 /*
295  * Structure of a blocks group descriptor
296  */
297 struct ext4_group_desc
298 {
299 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
300 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
301 	__le32	bg_inode_table_lo;	/* Inodes table block */
302 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
303 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
304 	__le16	bg_used_dirs_count_lo;	/* Directories count */
305 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
306 	__le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
307 	__le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
308 	__le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
309 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
310 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
311 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
312 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
313 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
314 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
315 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
316 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
317 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
318 	__le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
319 	__le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
320 	__le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
321 	__u32   bg_reserved;
322 };
323 
324 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END	\
325 	(offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
326 	 sizeof(__le16))
327 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END	\
328 	(offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
329 	 sizeof(__le16))
330 
331 /*
332  * Structure of a flex block group info
333  */
334 
335 struct flex_groups {
336 	atomic64_t	free_clusters;
337 	atomic_t	free_inodes;
338 	atomic_t	used_dirs;
339 };
340 
341 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
342 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
343 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
344 
345 /*
346  * Macro-instructions used to manage group descriptors
347  */
348 #define EXT4_MIN_DESC_SIZE		32
349 #define EXT4_MIN_DESC_SIZE_64BIT	64
350 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
351 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
352 #ifdef __KERNEL__
353 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
354 # define EXT4_CLUSTERS_PER_GROUP(s)	(EXT4_SB(s)->s_clusters_per_group)
355 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
356 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
357 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
358 #else
359 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
360 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
361 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
362 #endif
363 
364 /*
365  * Constants relative to the data blocks
366  */
367 #define	EXT4_NDIR_BLOCKS		12
368 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
369 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
370 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
371 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
372 
373 /*
374  * Inode flags
375  */
376 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
377 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
378 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
379 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
380 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
381 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
382 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
383 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
384 /* Reserved for compression usage... */
385 #define EXT4_DIRTY_FL			0x00000100
386 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
387 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
388 	/* nb: was previously EXT2_ECOMPR_FL */
389 #define EXT4_ENCRYPT_FL			0x00000800 /* encrypted file */
390 /* End compression flags --- maybe not all used */
391 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
392 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
393 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
394 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
395 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
396 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
397 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
398 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
399 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
400 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
401 #define EXT4_INLINE_DATA_FL		0x10000000 /* Inode has inline data. */
402 #define EXT4_PROJINHERIT_FL		0x20000000 /* Create with parents projid */
403 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
404 
405 #define EXT4_FL_USER_VISIBLE		0x304BDFFF /* User visible flags */
406 #define EXT4_FL_USER_MODIFIABLE		0x204BC0FF /* User modifiable flags */
407 
408 /* Flags we can manipulate with through EXT4_IOC_FSSETXATTR */
409 #define EXT4_FL_XFLAG_VISIBLE		(EXT4_SYNC_FL | \
410 					 EXT4_IMMUTABLE_FL | \
411 					 EXT4_APPEND_FL | \
412 					 EXT4_NODUMP_FL | \
413 					 EXT4_NOATIME_FL | \
414 					 EXT4_PROJINHERIT_FL)
415 
416 /* Flags that should be inherited by new inodes from their parent. */
417 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
418 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
419 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
420 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL |\
421 			   EXT4_PROJINHERIT_FL)
422 
423 /* Flags that are appropriate for regular files (all but dir-specific ones). */
424 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
425 
426 /* Flags that are appropriate for non-directories/regular files. */
427 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
428 
429 /* Mask out flags that are inappropriate for the given type of inode. */
430 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
431 {
432 	if (S_ISDIR(mode))
433 		return flags;
434 	else if (S_ISREG(mode))
435 		return flags & EXT4_REG_FLMASK;
436 	else
437 		return flags & EXT4_OTHER_FLMASK;
438 }
439 
440 /*
441  * Inode flags used for atomic set/get
442  */
443 enum {
444 	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
445 	EXT4_INODE_UNRM		= 1,	/* Undelete */
446 	EXT4_INODE_COMPR	= 2,	/* Compress file */
447 	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
448 	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
449 	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
450 	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
451 	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
452 /* Reserved for compression usage... */
453 	EXT4_INODE_DIRTY	= 8,
454 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
455 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
456 	EXT4_INODE_ENCRYPT	= 11,	/* Encrypted file */
457 /* End compression flags --- maybe not all used */
458 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
459 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
460 	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
461 	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
462 	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
463 	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
464 	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
465 	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
466 	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
467 	EXT4_INODE_EOFBLOCKS	= 22,	/* Blocks allocated beyond EOF */
468 	EXT4_INODE_INLINE_DATA	= 28,	/* Data in inode. */
469 	EXT4_INODE_PROJINHERIT	= 29,	/* Create with parents projid */
470 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
471 };
472 
473 /*
474  * Since it's pretty easy to mix up bit numbers and hex values, we use a
475  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
476  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
477  * any extra space in the compiled kernel image, otherwise, the build will fail.
478  * It's important that these values are the same, since we are using
479  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
480  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
481  * values found in ext2, ext3 and ext4 filesystems, and of course the values
482  * defined in e2fsprogs.
483  *
484  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
485  */
486 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
487 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
488 
489 static inline void ext4_check_flag_values(void)
490 {
491 	CHECK_FLAG_VALUE(SECRM);
492 	CHECK_FLAG_VALUE(UNRM);
493 	CHECK_FLAG_VALUE(COMPR);
494 	CHECK_FLAG_VALUE(SYNC);
495 	CHECK_FLAG_VALUE(IMMUTABLE);
496 	CHECK_FLAG_VALUE(APPEND);
497 	CHECK_FLAG_VALUE(NODUMP);
498 	CHECK_FLAG_VALUE(NOATIME);
499 	CHECK_FLAG_VALUE(DIRTY);
500 	CHECK_FLAG_VALUE(COMPRBLK);
501 	CHECK_FLAG_VALUE(NOCOMPR);
502 	CHECK_FLAG_VALUE(ENCRYPT);
503 	CHECK_FLAG_VALUE(INDEX);
504 	CHECK_FLAG_VALUE(IMAGIC);
505 	CHECK_FLAG_VALUE(JOURNAL_DATA);
506 	CHECK_FLAG_VALUE(NOTAIL);
507 	CHECK_FLAG_VALUE(DIRSYNC);
508 	CHECK_FLAG_VALUE(TOPDIR);
509 	CHECK_FLAG_VALUE(HUGE_FILE);
510 	CHECK_FLAG_VALUE(EXTENTS);
511 	CHECK_FLAG_VALUE(EA_INODE);
512 	CHECK_FLAG_VALUE(EOFBLOCKS);
513 	CHECK_FLAG_VALUE(INLINE_DATA);
514 	CHECK_FLAG_VALUE(PROJINHERIT);
515 	CHECK_FLAG_VALUE(RESERVED);
516 }
517 
518 /* Used to pass group descriptor data when online resize is done */
519 struct ext4_new_group_input {
520 	__u32 group;		/* Group number for this data */
521 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
522 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
523 	__u64 inode_table;	/* Absolute block number of inode table start */
524 	__u32 blocks_count;	/* Total number of blocks in this group */
525 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
526 	__u16 unused;
527 };
528 
529 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
530 struct compat_ext4_new_group_input {
531 	u32 group;
532 	compat_u64 block_bitmap;
533 	compat_u64 inode_bitmap;
534 	compat_u64 inode_table;
535 	u32 blocks_count;
536 	u16 reserved_blocks;
537 	u16 unused;
538 };
539 #endif
540 
541 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
542 struct ext4_new_group_data {
543 	__u32 group;
544 	__u64 block_bitmap;
545 	__u64 inode_bitmap;
546 	__u64 inode_table;
547 	__u32 blocks_count;
548 	__u16 reserved_blocks;
549 	__u16 mdata_blocks;
550 	__u32 free_clusters_count;
551 };
552 
553 /* Indexes used to index group tables in ext4_new_group_data */
554 enum {
555 	BLOCK_BITMAP = 0,	/* block bitmap */
556 	INODE_BITMAP,		/* inode bitmap */
557 	INODE_TABLE,		/* inode tables */
558 	GROUP_TABLE_COUNT,
559 };
560 
561 /*
562  * Flags used by ext4_map_blocks()
563  */
564 	/* Allocate any needed blocks and/or convert an unwritten
565 	   extent to be an initialized ext4 */
566 #define EXT4_GET_BLOCKS_CREATE			0x0001
567 	/* Request the creation of an unwritten extent */
568 #define EXT4_GET_BLOCKS_UNWRIT_EXT		0x0002
569 #define EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT	(EXT4_GET_BLOCKS_UNWRIT_EXT|\
570 						 EXT4_GET_BLOCKS_CREATE)
571 	/* Caller is from the delayed allocation writeout path
572 	 * finally doing the actual allocation of delayed blocks */
573 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
574 	/* caller is from the direct IO path, request to creation of an
575 	unwritten extents if not allocated, split the unwritten
576 	extent if blocks has been preallocated already*/
577 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
578 #define EXT4_GET_BLOCKS_CONVERT			0x0010
579 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
580 					 EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
581 	/* Convert extent to initialized after IO complete */
582 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
583 					 EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
584 	/* Eventual metadata allocation (due to growing extent tree)
585 	 * should not fail, so try to use reserved blocks for that.*/
586 #define EXT4_GET_BLOCKS_METADATA_NOFAIL		0x0020
587 	/* Don't normalize allocation size (used for fallocate) */
588 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
589 	/* Request will not result in inode size update (user for fallocate) */
590 #define EXT4_GET_BLOCKS_KEEP_SIZE		0x0080
591 	/* Convert written extents to unwritten */
592 #define EXT4_GET_BLOCKS_CONVERT_UNWRITTEN	0x0100
593 	/* Write zeros to newly created written extents */
594 #define EXT4_GET_BLOCKS_ZERO			0x0200
595 #define EXT4_GET_BLOCKS_CREATE_ZERO		(EXT4_GET_BLOCKS_CREATE |\
596 					EXT4_GET_BLOCKS_ZERO)
597 	/* Caller will submit data before dropping transaction handle. This
598 	 * allows jbd2 to avoid submitting data before commit. */
599 #define EXT4_GET_BLOCKS_IO_SUBMIT		0x0400
600 
601 /*
602  * The bit position of these flags must not overlap with any of the
603  * EXT4_GET_BLOCKS_*.  They are used by ext4_find_extent(),
604  * read_extent_tree_block(), ext4_split_extent_at(),
605  * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf().
606  * EXT4_EX_NOCACHE is used to indicate that the we shouldn't be
607  * caching the extents when reading from the extent tree while a
608  * truncate or punch hole operation is in progress.
609  */
610 #define EXT4_EX_NOCACHE				0x40000000
611 #define EXT4_EX_FORCE_CACHE			0x20000000
612 
613 /*
614  * Flags used by ext4_free_blocks
615  */
616 #define EXT4_FREE_BLOCKS_METADATA		0x0001
617 #define EXT4_FREE_BLOCKS_FORGET			0x0002
618 #define EXT4_FREE_BLOCKS_VALIDATED		0x0004
619 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE		0x0008
620 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
621 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
622 #define EXT4_FREE_BLOCKS_RERESERVE_CLUSTER      0x0040
623 
624 /*
625  * ioctl commands
626  */
627 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
628 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
629 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
630 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
631 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
632 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
633 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
634 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
635 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
636 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
637 #define EXT4_IOC_MIGRATE		_IO('f', 9)
638  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
639  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
640 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
641 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
642 #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
643 #define EXT4_IOC_SWAP_BOOT		_IO('f', 17)
644 #define EXT4_IOC_PRECACHE_EXTENTS	_IO('f', 18)
645 #define EXT4_IOC_SET_ENCRYPTION_POLICY	FS_IOC_SET_ENCRYPTION_POLICY
646 #define EXT4_IOC_GET_ENCRYPTION_PWSALT	FS_IOC_GET_ENCRYPTION_PWSALT
647 #define EXT4_IOC_GET_ENCRYPTION_POLICY	FS_IOC_GET_ENCRYPTION_POLICY
648 
649 #define EXT4_IOC_FSGETXATTR		FS_IOC_FSGETXATTR
650 #define EXT4_IOC_FSSETXATTR		FS_IOC_FSSETXATTR
651 
652 #define EXT4_IOC_SHUTDOWN _IOR ('X', 125, __u32)
653 
654 /*
655  * Flags for going down operation
656  */
657 #define EXT4_GOING_FLAGS_DEFAULT		0x0	/* going down */
658 #define EXT4_GOING_FLAGS_LOGFLUSH		0x1	/* flush log but not data */
659 #define EXT4_GOING_FLAGS_NOLOGFLUSH		0x2	/* don't flush log nor data */
660 
661 
662 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
663 /*
664  * ioctl commands in 32 bit emulation
665  */
666 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
667 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
668 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
669 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
670 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
671 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
672 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
673 #define EXT4_IOC32_GROUP_ADD		_IOW('f', 8, struct compat_ext4_new_group_input)
674 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
675 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
676 #endif
677 
678 /* Max physical block we can address w/o extents */
679 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
680 
681 /* Max logical block we can support */
682 #define EXT4_MAX_LOGICAL_BLOCK		0xFFFFFFFF
683 
684 /*
685  * Structure of an inode on the disk
686  */
687 struct ext4_inode {
688 	__le16	i_mode;		/* File mode */
689 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
690 	__le32	i_size_lo;	/* Size in bytes */
691 	__le32	i_atime;	/* Access time */
692 	__le32	i_ctime;	/* Inode Change time */
693 	__le32	i_mtime;	/* Modification time */
694 	__le32	i_dtime;	/* Deletion Time */
695 	__le16	i_gid;		/* Low 16 bits of Group Id */
696 	__le16	i_links_count;	/* Links count */
697 	__le32	i_blocks_lo;	/* Blocks count */
698 	__le32	i_flags;	/* File flags */
699 	union {
700 		struct {
701 			__le32  l_i_version;
702 		} linux1;
703 		struct {
704 			__u32  h_i_translator;
705 		} hurd1;
706 		struct {
707 			__u32  m_i_reserved1;
708 		} masix1;
709 	} osd1;				/* OS dependent 1 */
710 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
711 	__le32	i_generation;	/* File version (for NFS) */
712 	__le32	i_file_acl_lo;	/* File ACL */
713 	__le32	i_size_high;
714 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
715 	union {
716 		struct {
717 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
718 			__le16	l_i_file_acl_high;
719 			__le16	l_i_uid_high;	/* these 2 fields */
720 			__le16	l_i_gid_high;	/* were reserved2[0] */
721 			__le16	l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
722 			__le16	l_i_reserved;
723 		} linux2;
724 		struct {
725 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
726 			__u16	h_i_mode_high;
727 			__u16	h_i_uid_high;
728 			__u16	h_i_gid_high;
729 			__u32	h_i_author;
730 		} hurd2;
731 		struct {
732 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
733 			__le16	m_i_file_acl_high;
734 			__u32	m_i_reserved2[2];
735 		} masix2;
736 	} osd2;				/* OS dependent 2 */
737 	__le16	i_extra_isize;
738 	__le16	i_checksum_hi;	/* crc32c(uuid+inum+inode) BE */
739 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
740 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
741 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
742 	__le32  i_crtime;       /* File Creation time */
743 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
744 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
745 	__le32	i_projid;	/* Project ID */
746 };
747 
748 struct move_extent {
749 	__u32 reserved;		/* should be zero */
750 	__u32 donor_fd;		/* donor file descriptor */
751 	__u64 orig_start;	/* logical start offset in block for orig */
752 	__u64 donor_start;	/* logical start offset in block for donor */
753 	__u64 len;		/* block length to be moved */
754 	__u64 moved_len;	/* moved block length */
755 };
756 
757 #define EXT4_EPOCH_BITS 2
758 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
759 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
760 
761 /*
762  * Extended fields will fit into an inode if the filesystem was formatted
763  * with large inodes (-I 256 or larger) and there are not currently any EAs
764  * consuming all of the available space. For new inodes we always reserve
765  * enough space for the kernel's known extended fields, but for inodes
766  * created with an old kernel this might not have been the case. None of
767  * the extended inode fields is critical for correct filesystem operation.
768  * This macro checks if a certain field fits in the inode. Note that
769  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
770  */
771 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
772 	((offsetof(typeof(*ext4_inode), field) +	\
773 	  sizeof((ext4_inode)->field))			\
774 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
775 	    (einode)->i_extra_isize))			\
776 
777 /*
778  * We use an encoding that preserves the times for extra epoch "00":
779  *
780  * extra  msb of                         adjust for signed
781  * epoch  32-bit                         32-bit tv_sec to
782  * bits   time    decoded 64-bit tv_sec  64-bit tv_sec      valid time range
783  * 0 0    1    -0x80000000..-0x00000001  0x000000000 1901-12-13..1969-12-31
784  * 0 0    0    0x000000000..0x07fffffff  0x000000000 1970-01-01..2038-01-19
785  * 0 1    1    0x080000000..0x0ffffffff  0x100000000 2038-01-19..2106-02-07
786  * 0 1    0    0x100000000..0x17fffffff  0x100000000 2106-02-07..2174-02-25
787  * 1 0    1    0x180000000..0x1ffffffff  0x200000000 2174-02-25..2242-03-16
788  * 1 0    0    0x200000000..0x27fffffff  0x200000000 2242-03-16..2310-04-04
789  * 1 1    1    0x280000000..0x2ffffffff  0x300000000 2310-04-04..2378-04-22
790  * 1 1    0    0x300000000..0x37fffffff  0x300000000 2378-04-22..2446-05-10
791  *
792  * Note that previous versions of the kernel on 64-bit systems would
793  * incorrectly use extra epoch bits 1,1 for dates between 1901 and
794  * 1970.  e2fsck will correct this, assuming that it is run on the
795  * affected filesystem before 2242.
796  */
797 
798 static inline __le32 ext4_encode_extra_time(struct timespec64 *time)
799 {
800 	u32 extra =((time->tv_sec - (s32)time->tv_sec) >> 32) & EXT4_EPOCH_MASK;
801 	return cpu_to_le32(extra | (time->tv_nsec << EXT4_EPOCH_BITS));
802 }
803 
804 static inline void ext4_decode_extra_time(struct timespec64 *time,
805 					  __le32 extra)
806 {
807 	if (unlikely(extra & cpu_to_le32(EXT4_EPOCH_MASK))) {
808 
809 #if 1
810 		/* Handle legacy encoding of pre-1970 dates with epoch
811 		 * bits 1,1. (This backwards compatibility may be removed
812 		 * at the discretion of the ext4 developers.)
813 		 */
814 		u64 extra_bits = le32_to_cpu(extra) & EXT4_EPOCH_MASK;
815 		if (extra_bits == 3 && ((time->tv_sec) & 0x80000000) != 0)
816 			extra_bits = 0;
817 		time->tv_sec += extra_bits << 32;
818 #else
819 		time->tv_sec += (u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK) << 32;
820 #endif
821 	}
822 	time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
823 }
824 
825 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)				\
826 do {										\
827 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);		\
828 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     {\
829 		(raw_inode)->xtime ## _extra =					\
830 				ext4_encode_extra_time(&(inode)->xtime);	\
831 		}								\
832 } while (0)
833 
834 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
835 do {									       \
836 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
837 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
838 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
839 		(raw_inode)->xtime ## _extra =				       \
840 				ext4_encode_extra_time(&(einode)->xtime);      \
841 } while (0)
842 
843 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)				\
844 do {										\
845 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);	\
846 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra)) {	\
847 		ext4_decode_extra_time(&(inode)->xtime,				\
848 				       raw_inode->xtime ## _extra);		\
849 		}								\
850 	else									\
851 		(inode)->xtime.tv_nsec = 0;					\
852 } while (0)
853 
854 
855 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
856 do {									       \
857 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
858 		(einode)->xtime.tv_sec = 				       \
859 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
860 	else								       \
861 		(einode)->xtime.tv_sec = 0;				       \
862 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
863 		ext4_decode_extra_time(&(einode)->xtime,		       \
864 				       raw_inode->xtime ## _extra);	       \
865 	else								       \
866 		(einode)->xtime.tv_nsec = 0;				       \
867 } while (0)
868 
869 #define i_disk_version osd1.linux1.l_i_version
870 
871 #if defined(__KERNEL__) || defined(__linux__)
872 #define i_reserved1	osd1.linux1.l_i_reserved1
873 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
874 #define i_blocks_high	osd2.linux2.l_i_blocks_high
875 #define i_uid_low	i_uid
876 #define i_gid_low	i_gid
877 #define i_uid_high	osd2.linux2.l_i_uid_high
878 #define i_gid_high	osd2.linux2.l_i_gid_high
879 #define i_checksum_lo	osd2.linux2.l_i_checksum_lo
880 
881 #elif defined(__GNU__)
882 
883 #define i_translator	osd1.hurd1.h_i_translator
884 #define i_uid_high	osd2.hurd2.h_i_uid_high
885 #define i_gid_high	osd2.hurd2.h_i_gid_high
886 #define i_author	osd2.hurd2.h_i_author
887 
888 #elif defined(__masix__)
889 
890 #define i_reserved1	osd1.masix1.m_i_reserved1
891 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
892 #define i_reserved2	osd2.masix2.m_i_reserved2
893 
894 #endif /* defined(__KERNEL__) || defined(__linux__) */
895 
896 #include "extents_status.h"
897 
898 /*
899  * Lock subclasses for i_data_sem in the ext4_inode_info structure.
900  *
901  * These are needed to avoid lockdep false positives when we need to
902  * allocate blocks to the quota inode during ext4_map_blocks(), while
903  * holding i_data_sem for a normal (non-quota) inode.  Since we don't
904  * do quota tracking for the quota inode, this avoids deadlock (as
905  * well as infinite recursion, since it isn't turtles all the way
906  * down...)
907  *
908  *  I_DATA_SEM_NORMAL - Used for most inodes
909  *  I_DATA_SEM_OTHER  - Used by move_inode.c for the second normal inode
910  *			  where the second inode has larger inode number
911  *			  than the first
912  *  I_DATA_SEM_QUOTA  - Used for quota inodes only
913  */
914 enum {
915 	I_DATA_SEM_NORMAL = 0,
916 	I_DATA_SEM_OTHER,
917 	I_DATA_SEM_QUOTA,
918 };
919 
920 
921 /*
922  * fourth extended file system inode data in memory
923  */
924 struct ext4_inode_info {
925 	__le32	i_data[15];	/* unconverted */
926 	__u32	i_dtime;
927 	ext4_fsblk_t	i_file_acl;
928 
929 	/*
930 	 * i_block_group is the number of the block group which contains
931 	 * this file's inode.  Constant across the lifetime of the inode,
932 	 * it is used for making block allocation decisions - we try to
933 	 * place a file's data blocks near its inode block, and new inodes
934 	 * near to their parent directory's inode.
935 	 */
936 	ext4_group_t	i_block_group;
937 	ext4_lblk_t	i_dir_start_lookup;
938 #if (BITS_PER_LONG < 64)
939 	unsigned long	i_state_flags;		/* Dynamic state flags */
940 #endif
941 	unsigned long	i_flags;
942 
943 	/*
944 	 * Extended attributes can be read independently of the main file
945 	 * data. Taking i_mutex even when reading would cause contention
946 	 * between readers of EAs and writers of regular file data, so
947 	 * instead we synchronize on xattr_sem when reading or changing
948 	 * EAs.
949 	 */
950 	struct rw_semaphore xattr_sem;
951 
952 	struct list_head i_orphan;	/* unlinked but open inodes */
953 
954 	/*
955 	 * i_disksize keeps track of what the inode size is ON DISK, not
956 	 * in memory.  During truncate, i_size is set to the new size by
957 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
958 	 * set i_disksize to 0 until the truncate is actually under way.
959 	 *
960 	 * The intent is that i_disksize always represents the blocks which
961 	 * are used by this file.  This allows recovery to restart truncate
962 	 * on orphans if we crash during truncate.  We actually write i_disksize
963 	 * into the on-disk inode when writing inodes out, instead of i_size.
964 	 *
965 	 * The only time when i_disksize and i_size may be different is when
966 	 * a truncate is in progress.  The only things which change i_disksize
967 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
968 	 */
969 	loff_t	i_disksize;
970 
971 	/*
972 	 * i_data_sem is for serialising ext4_truncate() against
973 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
974 	 * data tree are chopped off during truncate. We can't do that in
975 	 * ext4 because whenever we perform intermediate commits during
976 	 * truncate, the inode and all the metadata blocks *must* be in a
977 	 * consistent state which allows truncation of the orphans to restart
978 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
979 	 * by other means, so we have i_data_sem.
980 	 */
981 	struct rw_semaphore i_data_sem;
982 	/*
983 	 * i_mmap_sem is for serializing page faults with truncate / punch hole
984 	 * operations. We have to make sure that new page cannot be faulted in
985 	 * a section of the inode that is being punched. We cannot easily use
986 	 * i_data_sem for this since we need protection for the whole punch
987 	 * operation and i_data_sem ranks below transaction start so we have
988 	 * to occasionally drop it.
989 	 */
990 	struct rw_semaphore i_mmap_sem;
991 	struct inode vfs_inode;
992 	struct jbd2_inode *jinode;
993 
994 	spinlock_t i_raw_lock;	/* protects updates to the raw inode */
995 
996 	/*
997 	 * File creation time. Its function is same as that of
998 	 * struct timespec64 i_{a,c,m}time in the generic inode.
999 	 */
1000 	struct timespec64 i_crtime;
1001 
1002 	/* mballoc */
1003 	struct list_head i_prealloc_list;
1004 	spinlock_t i_prealloc_lock;
1005 
1006 	/* extents status tree */
1007 	struct ext4_es_tree i_es_tree;
1008 	rwlock_t i_es_lock;
1009 	struct list_head i_es_list;
1010 	unsigned int i_es_all_nr;	/* protected by i_es_lock */
1011 	unsigned int i_es_shk_nr;	/* protected by i_es_lock */
1012 	ext4_lblk_t i_es_shrink_lblk;	/* Offset where we start searching for
1013 					   extents to shrink. Protected by
1014 					   i_es_lock  */
1015 
1016 	/* ialloc */
1017 	ext4_group_t	i_last_alloc_group;
1018 
1019 	/* allocation reservation info for delalloc */
1020 	/* In case of bigalloc, this refer to clusters rather than blocks */
1021 	unsigned int i_reserved_data_blocks;
1022 	ext4_lblk_t i_da_metadata_calc_last_lblock;
1023 	int i_da_metadata_calc_len;
1024 
1025 	/* pending cluster reservations for bigalloc file systems */
1026 	struct ext4_pending_tree i_pending_tree;
1027 
1028 	/* on-disk additional length */
1029 	__u16 i_extra_isize;
1030 
1031 	/* Indicate the inline data space. */
1032 	u16 i_inline_off;
1033 	u16 i_inline_size;
1034 
1035 #ifdef CONFIG_QUOTA
1036 	/* quota space reservation, managed internally by quota code */
1037 	qsize_t i_reserved_quota;
1038 #endif
1039 
1040 	/* Lock protecting lists below */
1041 	spinlock_t i_completed_io_lock;
1042 	/*
1043 	 * Completed IOs that need unwritten extents handling and have
1044 	 * transaction reserved
1045 	 */
1046 	struct list_head i_rsv_conversion_list;
1047 	struct work_struct i_rsv_conversion_work;
1048 	atomic_t i_unwritten; /* Nr. of inflight conversions pending */
1049 
1050 	spinlock_t i_block_reservation_lock;
1051 
1052 	/*
1053 	 * Transactions that contain inode's metadata needed to complete
1054 	 * fsync and fdatasync, respectively.
1055 	 */
1056 	tid_t i_sync_tid;
1057 	tid_t i_datasync_tid;
1058 
1059 #ifdef CONFIG_QUOTA
1060 	struct dquot *i_dquot[MAXQUOTAS];
1061 #endif
1062 
1063 	/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
1064 	__u32 i_csum_seed;
1065 
1066 	kprojid_t i_projid;
1067 };
1068 
1069 /*
1070  * File system states
1071  */
1072 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
1073 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
1074 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
1075 
1076 /*
1077  * Misc. filesystem flags
1078  */
1079 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
1080 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
1081 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
1082 
1083 /*
1084  * Mount flags set via mount options or defaults
1085  */
1086 #define EXT4_MOUNT_NO_MBCACHE		0x00001 /* Do not use mbcache */
1087 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
1088 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
1089 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
1090 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
1091 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
1092 #define EXT4_MOUNT_ERRORS_MASK		0x00070
1093 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
1094 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
1095 #ifdef CONFIG_FS_DAX
1096 #define EXT4_MOUNT_DAX			0x00200	/* Direct Access */
1097 #else
1098 #define EXT4_MOUNT_DAX			0
1099 #endif
1100 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
1101 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
1102 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
1103 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
1104 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
1105 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
1106 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
1107 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
1108 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
1109 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
1110 #define EXT4_MOUNT_QUOTA		0x40000 /* Some quota option set */
1111 #define EXT4_MOUNT_USRQUOTA		0x80000 /* "old" user quota,
1112 						 * enable enforcement for hidden
1113 						 * quota files */
1114 #define EXT4_MOUNT_GRPQUOTA		0x100000 /* "old" group quota, enable
1115 						  * enforcement for hidden quota
1116 						  * files */
1117 #define EXT4_MOUNT_PRJQUOTA		0x200000 /* Enable project quota
1118 						  * enforcement */
1119 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
1120 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
1121 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
1122 #define EXT4_MOUNT_WARN_ON_ERROR	0x2000000 /* Trigger WARN_ON on error */
1123 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
1124 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
1125 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
1126 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
1127 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
1128 
1129 /*
1130  * Mount flags set either automatically (could not be set by mount option)
1131  * based on per file system feature or property or in special cases such as
1132  * distinguishing between explicit mount option definition and default.
1133  */
1134 #define EXT4_MOUNT2_EXPLICIT_DELALLOC	0x00000001 /* User explicitly
1135 						      specified delalloc */
1136 #define EXT4_MOUNT2_STD_GROUP_SIZE	0x00000002 /* We have standard group
1137 						      size of blocksize * 8
1138 						      blocks */
1139 #define EXT4_MOUNT2_HURD_COMPAT		0x00000004 /* Support HURD-castrated
1140 						      file systems */
1141 
1142 #define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM	0x00000008 /* User explicitly
1143 						specified journal checksum */
1144 
1145 #define clear_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt &= \
1146 						~EXT4_MOUNT_##opt
1147 #define set_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt |= \
1148 						EXT4_MOUNT_##opt
1149 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
1150 					 EXT4_MOUNT_##opt)
1151 
1152 #define clear_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 &= \
1153 						~EXT4_MOUNT2_##opt
1154 #define set_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 |= \
1155 						EXT4_MOUNT2_##opt
1156 #define test_opt2(sb, opt)		(EXT4_SB(sb)->s_mount_opt2 & \
1157 					 EXT4_MOUNT2_##opt)
1158 
1159 #define ext4_test_and_set_bit		__test_and_set_bit_le
1160 #define ext4_set_bit			__set_bit_le
1161 #define ext4_set_bit_atomic		ext2_set_bit_atomic
1162 #define ext4_test_and_clear_bit		__test_and_clear_bit_le
1163 #define ext4_clear_bit			__clear_bit_le
1164 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
1165 #define ext4_test_bit			test_bit_le
1166 #define ext4_find_next_zero_bit		find_next_zero_bit_le
1167 #define ext4_find_next_bit		find_next_bit_le
1168 
1169 extern void ext4_set_bits(void *bm, int cur, int len);
1170 
1171 /*
1172  * Maximal mount counts between two filesystem checks
1173  */
1174 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
1175 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
1176 
1177 /*
1178  * Behaviour when detecting errors
1179  */
1180 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
1181 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
1182 #define EXT4_ERRORS_PANIC		3	/* Panic */
1183 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
1184 
1185 /* Metadata checksum algorithm codes */
1186 #define EXT4_CRC32C_CHKSUM		1
1187 
1188 /*
1189  * Structure of the super block
1190  */
1191 struct ext4_super_block {
1192 /*00*/	__le32	s_inodes_count;		/* Inodes count */
1193 	__le32	s_blocks_count_lo;	/* Blocks count */
1194 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
1195 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
1196 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
1197 	__le32	s_first_data_block;	/* First Data Block */
1198 	__le32	s_log_block_size;	/* Block size */
1199 	__le32	s_log_cluster_size;	/* Allocation cluster size */
1200 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
1201 	__le32	s_clusters_per_group;	/* # Clusters per group */
1202 	__le32	s_inodes_per_group;	/* # Inodes per group */
1203 	__le32	s_mtime;		/* Mount time */
1204 /*30*/	__le32	s_wtime;		/* Write time */
1205 	__le16	s_mnt_count;		/* Mount count */
1206 	__le16	s_max_mnt_count;	/* Maximal mount count */
1207 	__le16	s_magic;		/* Magic signature */
1208 	__le16	s_state;		/* File system state */
1209 	__le16	s_errors;		/* Behaviour when detecting errors */
1210 	__le16	s_minor_rev_level;	/* minor revision level */
1211 /*40*/	__le32	s_lastcheck;		/* time of last check */
1212 	__le32	s_checkinterval;	/* max. time between checks */
1213 	__le32	s_creator_os;		/* OS */
1214 	__le32	s_rev_level;		/* Revision level */
1215 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
1216 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
1217 	/*
1218 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
1219 	 *
1220 	 * Note: the difference between the compatible feature set and
1221 	 * the incompatible feature set is that if there is a bit set
1222 	 * in the incompatible feature set that the kernel doesn't
1223 	 * know about, it should refuse to mount the filesystem.
1224 	 *
1225 	 * e2fsck's requirements are more strict; if it doesn't know
1226 	 * about a feature in either the compatible or incompatible
1227 	 * feature set, it must abort and not try to meddle with
1228 	 * things it doesn't understand...
1229 	 */
1230 	__le32	s_first_ino;		/* First non-reserved inode */
1231 	__le16  s_inode_size;		/* size of inode structure */
1232 	__le16	s_block_group_nr;	/* block group # of this superblock */
1233 	__le32	s_feature_compat;	/* compatible feature set */
1234 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
1235 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
1236 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
1237 /*78*/	char	s_volume_name[16];	/* volume name */
1238 /*88*/	char	s_last_mounted[64] __nonstring;	/* directory where last mounted */
1239 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
1240 	/*
1241 	 * Performance hints.  Directory preallocation should only
1242 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1243 	 */
1244 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
1245 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
1246 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
1247 	/*
1248 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1249 	 */
1250 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
1251 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
1252 	__le32	s_journal_dev;		/* device number of journal file */
1253 	__le32	s_last_orphan;		/* start of list of inodes to delete */
1254 	__le32	s_hash_seed[4];		/* HTREE hash seed */
1255 	__u8	s_def_hash_version;	/* Default hash version to use */
1256 	__u8	s_jnl_backup_type;
1257 	__le16  s_desc_size;		/* size of group descriptor */
1258 /*100*/	__le32	s_default_mount_opts;
1259 	__le32	s_first_meta_bg;	/* First metablock block group */
1260 	__le32	s_mkfs_time;		/* When the filesystem was created */
1261 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
1262 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1263 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
1264 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
1265 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
1266 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
1267 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
1268 	__le32	s_flags;		/* Miscellaneous flags */
1269 	__le16  s_raid_stride;		/* RAID stride */
1270 	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1271 	__le64  s_mmp_block;            /* Block for multi-mount protection */
1272 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1273 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
1274 	__u8	s_checksum_type;	/* metadata checksum algorithm used */
1275 	__u8	s_encryption_level;	/* versioning level for encryption */
1276 	__u8	s_reserved_pad;		/* Padding to next 32bits */
1277 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1278 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
1279 	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
1280 	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
1281 					      snapshot's future use */
1282 	__le32	s_snapshot_list;	/* inode number of the head of the
1283 					   on-disk snapshot list */
1284 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1285 	__le32	s_error_count;		/* number of fs errors */
1286 	__le32	s_first_error_time;	/* first time an error happened */
1287 	__le32	s_first_error_ino;	/* inode involved in first error */
1288 	__le64	s_first_error_block;	/* block involved of first error */
1289 	__u8	s_first_error_func[32] __nonstring;	/* function where the error happened */
1290 	__le32	s_first_error_line;	/* line number where error happened */
1291 	__le32	s_last_error_time;	/* most recent time of an error */
1292 	__le32	s_last_error_ino;	/* inode involved in last error */
1293 	__le32	s_last_error_line;	/* line number where error happened */
1294 	__le64	s_last_error_block;	/* block involved of last error */
1295 	__u8	s_last_error_func[32] __nonstring;	/* function where the error happened */
1296 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1297 	__u8	s_mount_opts[64];
1298 	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
1299 	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
1300 	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
1301 	__le32	s_backup_bgs[2];	/* groups with sparse_super2 SBs */
1302 	__u8	s_encrypt_algos[4];	/* Encryption algorithms in use  */
1303 	__u8	s_encrypt_pw_salt[16];	/* Salt used for string2key algorithm */
1304 	__le32	s_lpf_ino;		/* Location of the lost+found inode */
1305 	__le32	s_prj_quota_inum;	/* inode for tracking project quota */
1306 	__le32	s_checksum_seed;	/* crc32c(uuid) if csum_seed set */
1307 	__u8	s_wtime_hi;
1308 	__u8	s_mtime_hi;
1309 	__u8	s_mkfs_time_hi;
1310 	__u8	s_lastcheck_hi;
1311 	__u8	s_first_error_time_hi;
1312 	__u8	s_last_error_time_hi;
1313 	__u8	s_pad[2];
1314 	__le32	s_reserved[96];		/* Padding to the end of the block */
1315 	__le32	s_checksum;		/* crc32c(superblock) */
1316 };
1317 
1318 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1319 
1320 #ifdef __KERNEL__
1321 
1322 /*
1323  * run-time mount flags
1324  */
1325 #define EXT4_MF_MNTDIR_SAMPLED		0x0001
1326 #define EXT4_MF_FS_ABORTED		0x0002	/* Fatal error detected */
1327 #define EXT4_MF_TEST_DUMMY_ENCRYPTION	0x0004
1328 
1329 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1330 #define DUMMY_ENCRYPTION_ENABLED(sbi) (unlikely((sbi)->s_mount_flags & \
1331 						EXT4_MF_TEST_DUMMY_ENCRYPTION))
1332 #else
1333 #define DUMMY_ENCRYPTION_ENABLED(sbi) (0)
1334 #endif
1335 
1336 /* Number of quota types we support */
1337 #define EXT4_MAXQUOTAS 3
1338 
1339 /*
1340  * fourth extended-fs super-block data in memory
1341  */
1342 struct ext4_sb_info {
1343 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
1344 	unsigned long s_inodes_per_block;/* Number of inodes per block */
1345 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
1346 	unsigned long s_clusters_per_group; /* Number of clusters in a group */
1347 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
1348 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
1349 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
1350 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
1351 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1352 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1353 	unsigned long s_overhead;  /* # of fs overhead clusters */
1354 	unsigned int s_cluster_ratio;	/* Number of blocks per cluster */
1355 	unsigned int s_cluster_bits;	/* log2 of s_cluster_ratio */
1356 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
1357 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
1358 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
1359 	struct buffer_head **s_group_desc;
1360 	unsigned int s_mount_opt;
1361 	unsigned int s_mount_opt2;
1362 	unsigned int s_mount_flags;
1363 	unsigned int s_def_mount_opt;
1364 	ext4_fsblk_t s_sb_block;
1365 	atomic64_t s_resv_clusters;
1366 	kuid_t s_resuid;
1367 	kgid_t s_resgid;
1368 	unsigned short s_mount_state;
1369 	unsigned short s_pad;
1370 	int s_addr_per_block_bits;
1371 	int s_desc_per_block_bits;
1372 	int s_inode_size;
1373 	int s_first_ino;
1374 	unsigned int s_inode_readahead_blks;
1375 	unsigned int s_inode_goal;
1376 	u32 s_hash_seed[4];
1377 	int s_def_hash_version;
1378 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
1379 	struct percpu_counter s_freeclusters_counter;
1380 	struct percpu_counter s_freeinodes_counter;
1381 	struct percpu_counter s_dirs_counter;
1382 	struct percpu_counter s_dirtyclusters_counter;
1383 	struct blockgroup_lock *s_blockgroup_lock;
1384 	struct proc_dir_entry *s_proc;
1385 	struct kobject s_kobj;
1386 	struct completion s_kobj_unregister;
1387 	struct super_block *s_sb;
1388 
1389 	/* Journaling */
1390 	struct journal_s *s_journal;
1391 	struct list_head s_orphan;
1392 	struct mutex s_orphan_lock;
1393 	unsigned long s_ext4_flags;		/* Ext4 superblock flags */
1394 	unsigned long s_commit_interval;
1395 	u32 s_max_batch_time;
1396 	u32 s_min_batch_time;
1397 	struct block_device *journal_bdev;
1398 #ifdef CONFIG_QUOTA
1399 	/* Names of quota files with journalled quota */
1400 	char __rcu *s_qf_names[EXT4_MAXQUOTAS];
1401 	int s_jquota_fmt;			/* Format of quota to use */
1402 #endif
1403 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1404 	struct rb_root system_blks;
1405 
1406 #ifdef EXTENTS_STATS
1407 	/* ext4 extents stats */
1408 	unsigned long s_ext_min;
1409 	unsigned long s_ext_max;
1410 	unsigned long s_depth_max;
1411 	spinlock_t s_ext_stats_lock;
1412 	unsigned long s_ext_blocks;
1413 	unsigned long s_ext_extents;
1414 #endif
1415 
1416 	/* for buddy allocator */
1417 	struct ext4_group_info ***s_group_info;
1418 	struct inode *s_buddy_cache;
1419 	spinlock_t s_md_lock;
1420 	unsigned short *s_mb_offsets;
1421 	unsigned int *s_mb_maxs;
1422 	unsigned int s_group_info_size;
1423 	unsigned int s_mb_free_pending;
1424 	struct list_head s_freed_data_list;	/* List of blocks to be freed
1425 						   after commit completed */
1426 
1427 	/* tunables */
1428 	unsigned long s_stripe;
1429 	unsigned int s_mb_stream_request;
1430 	unsigned int s_mb_max_to_scan;
1431 	unsigned int s_mb_min_to_scan;
1432 	unsigned int s_mb_stats;
1433 	unsigned int s_mb_order2_reqs;
1434 	unsigned int s_mb_group_prealloc;
1435 	unsigned int s_max_dir_size_kb;
1436 	/* where last allocation was done - for stream allocation */
1437 	unsigned long s_mb_last_group;
1438 	unsigned long s_mb_last_start;
1439 
1440 	/* stats for buddy allocator */
1441 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1442 	atomic_t s_bal_success;	/* we found long enough chunks */
1443 	atomic_t s_bal_allocated;	/* in blocks */
1444 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1445 	atomic_t s_bal_goals;	/* goal hits */
1446 	atomic_t s_bal_breaks;	/* too long searches */
1447 	atomic_t s_bal_2orders;	/* 2^order hits */
1448 	spinlock_t s_bal_lock;
1449 	unsigned long s_mb_buddies_generated;
1450 	unsigned long long s_mb_generation_time;
1451 	atomic_t s_mb_lost_chunks;
1452 	atomic_t s_mb_preallocated;
1453 	atomic_t s_mb_discarded;
1454 	atomic_t s_lock_busy;
1455 
1456 	/* locality groups */
1457 	struct ext4_locality_group __percpu *s_locality_groups;
1458 
1459 	/* for write statistics */
1460 	unsigned long s_sectors_written_start;
1461 	u64 s_kbytes_written;
1462 
1463 	/* the size of zero-out chunk */
1464 	unsigned int s_extent_max_zeroout_kb;
1465 
1466 	unsigned int s_log_groups_per_flex;
1467 	struct flex_groups *s_flex_groups;
1468 	ext4_group_t s_flex_groups_allocated;
1469 
1470 	/* workqueue for reserved extent conversions (buffered io) */
1471 	struct workqueue_struct *rsv_conversion_wq;
1472 
1473 	/* timer for periodic error stats printing */
1474 	struct timer_list s_err_report;
1475 
1476 	/* Lazy inode table initialization info */
1477 	struct ext4_li_request *s_li_request;
1478 	/* Wait multiplier for lazy initialization thread */
1479 	unsigned int s_li_wait_mult;
1480 
1481 	/* Kernel thread for multiple mount protection */
1482 	struct task_struct *s_mmp_tsk;
1483 
1484 	/* record the last minlen when FITRIM is called. */
1485 	atomic_t s_last_trim_minblks;
1486 
1487 	/* Reference to checksum algorithm driver via cryptoapi */
1488 	struct crypto_shash *s_chksum_driver;
1489 
1490 	/* Precomputed FS UUID checksum for seeding other checksums */
1491 	__u32 s_csum_seed;
1492 
1493 	/* Reclaim extents from extent status tree */
1494 	struct shrinker s_es_shrinker;
1495 	struct list_head s_es_list;	/* List of inodes with reclaimable extents */
1496 	long s_es_nr_inode;
1497 	struct ext4_es_stats s_es_stats;
1498 	struct mb_cache *s_ea_block_cache;
1499 	struct mb_cache *s_ea_inode_cache;
1500 	spinlock_t s_es_lock ____cacheline_aligned_in_smp;
1501 
1502 	/* Ratelimit ext4 messages. */
1503 	struct ratelimit_state s_err_ratelimit_state;
1504 	struct ratelimit_state s_warning_ratelimit_state;
1505 	struct ratelimit_state s_msg_ratelimit_state;
1506 
1507 	/* Barrier between changing inodes' journal flags and writepages ops. */
1508 	struct percpu_rw_semaphore s_journal_flag_rwsem;
1509 	struct dax_device *s_daxdev;
1510 };
1511 
1512 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1513 {
1514 	return sb->s_fs_info;
1515 }
1516 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1517 {
1518 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1519 }
1520 
1521 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1522 {
1523 	return ino == EXT4_ROOT_INO ||
1524 		(ino >= EXT4_FIRST_INO(sb) &&
1525 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1526 }
1527 
1528 /*
1529  * Inode dynamic state flags
1530  */
1531 enum {
1532 	EXT4_STATE_JDATA,		/* journaled data exists */
1533 	EXT4_STATE_NEW,			/* inode is newly created */
1534 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1535 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1536 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1537 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1538 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1539 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1540 	EXT4_STATE_MAY_INLINE_DATA,	/* may have in-inode data */
1541 	EXT4_STATE_EXT_PRECACHED,	/* extents have been precached */
1542 	EXT4_STATE_LUSTRE_EA_INODE,	/* Lustre-style ea_inode */
1543 };
1544 
1545 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
1546 static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
1547 {									\
1548 	return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);	\
1549 }									\
1550 static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
1551 {									\
1552 	set_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1553 }									\
1554 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1555 {									\
1556 	clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1557 }
1558 
1559 /* Add these declarations here only so that these functions can be
1560  * found by name.  Otherwise, they are very hard to locate. */
1561 static inline int ext4_test_inode_flag(struct inode *inode, int bit);
1562 static inline void ext4_set_inode_flag(struct inode *inode, int bit);
1563 static inline void ext4_clear_inode_flag(struct inode *inode, int bit);
1564 EXT4_INODE_BIT_FNS(flag, flags, 0)
1565 
1566 /* Add these declarations here only so that these functions can be
1567  * found by name.  Otherwise, they are very hard to locate. */
1568 static inline int ext4_test_inode_state(struct inode *inode, int bit);
1569 static inline void ext4_set_inode_state(struct inode *inode, int bit);
1570 static inline void ext4_clear_inode_state(struct inode *inode, int bit);
1571 #if (BITS_PER_LONG < 64)
1572 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1573 
1574 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1575 {
1576 	(ei)->i_state_flags = 0;
1577 }
1578 #else
1579 EXT4_INODE_BIT_FNS(state, flags, 32)
1580 
1581 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1582 {
1583 	/* We depend on the fact that callers will set i_flags */
1584 }
1585 #endif
1586 #else
1587 /* Assume that user mode programs are passing in an ext4fs superblock, not
1588  * a kernel struct super_block.  This will allow us to call the feature-test
1589  * macros from user land. */
1590 #define EXT4_SB(sb)	(sb)
1591 #endif
1592 
1593 /*
1594  * Returns true if the inode is inode is encrypted
1595  */
1596 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1597 
1598 /*
1599  * Codes for operating systems
1600  */
1601 #define EXT4_OS_LINUX		0
1602 #define EXT4_OS_HURD		1
1603 #define EXT4_OS_MASIX		2
1604 #define EXT4_OS_FREEBSD		3
1605 #define EXT4_OS_LITES		4
1606 
1607 /*
1608  * Revision levels
1609  */
1610 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1611 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1612 
1613 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1614 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1615 
1616 #define EXT4_GOOD_OLD_INODE_SIZE 128
1617 
1618 /*
1619  * Feature set definitions
1620  */
1621 
1622 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1623 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1624 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1625 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1626 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1627 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1628 #define EXT4_FEATURE_COMPAT_SPARSE_SUPER2	0x0200
1629 
1630 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1631 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1632 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1633 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1634 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1635 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1636 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1637 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
1638 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
1639 /*
1640  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1641  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1642  * all other data structures' checksums.  However, the METADATA_CSUM and
1643  * GDT_CSUM bits are mutually exclusive.
1644  */
1645 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
1646 #define EXT4_FEATURE_RO_COMPAT_READONLY		0x1000
1647 #define EXT4_FEATURE_RO_COMPAT_PROJECT		0x2000
1648 
1649 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1650 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1651 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1652 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1653 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1654 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1655 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1656 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1657 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1658 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1659 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1660 #define EXT4_FEATURE_INCOMPAT_CSUM_SEED		0x2000
1661 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
1662 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA	0x8000 /* data in inode */
1663 #define EXT4_FEATURE_INCOMPAT_ENCRYPT		0x10000
1664 
1665 #define EXT4_FEATURE_COMPAT_FUNCS(name, flagname) \
1666 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1667 { \
1668 	return ((EXT4_SB(sb)->s_es->s_feature_compat & \
1669 		cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname)) != 0); \
1670 } \
1671 static inline void ext4_set_feature_##name(struct super_block *sb) \
1672 { \
1673 	EXT4_SB(sb)->s_es->s_feature_compat |= \
1674 		cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname); \
1675 } \
1676 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1677 { \
1678 	EXT4_SB(sb)->s_es->s_feature_compat &= \
1679 		~cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname); \
1680 }
1681 
1682 #define EXT4_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
1683 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1684 { \
1685 	return ((EXT4_SB(sb)->s_es->s_feature_ro_compat & \
1686 		cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname)) != 0); \
1687 } \
1688 static inline void ext4_set_feature_##name(struct super_block *sb) \
1689 { \
1690 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= \
1691 		cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname); \
1692 } \
1693 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1694 { \
1695 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= \
1696 		~cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname); \
1697 }
1698 
1699 #define EXT4_FEATURE_INCOMPAT_FUNCS(name, flagname) \
1700 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1701 { \
1702 	return ((EXT4_SB(sb)->s_es->s_feature_incompat & \
1703 		cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname)) != 0); \
1704 } \
1705 static inline void ext4_set_feature_##name(struct super_block *sb) \
1706 { \
1707 	EXT4_SB(sb)->s_es->s_feature_incompat |= \
1708 		cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname); \
1709 } \
1710 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1711 { \
1712 	EXT4_SB(sb)->s_es->s_feature_incompat &= \
1713 		~cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname); \
1714 }
1715 
1716 EXT4_FEATURE_COMPAT_FUNCS(dir_prealloc,		DIR_PREALLOC)
1717 EXT4_FEATURE_COMPAT_FUNCS(imagic_inodes,	IMAGIC_INODES)
1718 EXT4_FEATURE_COMPAT_FUNCS(journal,		HAS_JOURNAL)
1719 EXT4_FEATURE_COMPAT_FUNCS(xattr,		EXT_ATTR)
1720 EXT4_FEATURE_COMPAT_FUNCS(resize_inode,		RESIZE_INODE)
1721 EXT4_FEATURE_COMPAT_FUNCS(dir_index,		DIR_INDEX)
1722 EXT4_FEATURE_COMPAT_FUNCS(sparse_super2,	SPARSE_SUPER2)
1723 
1724 EXT4_FEATURE_RO_COMPAT_FUNCS(sparse_super,	SPARSE_SUPER)
1725 EXT4_FEATURE_RO_COMPAT_FUNCS(large_file,	LARGE_FILE)
1726 EXT4_FEATURE_RO_COMPAT_FUNCS(btree_dir,		BTREE_DIR)
1727 EXT4_FEATURE_RO_COMPAT_FUNCS(huge_file,		HUGE_FILE)
1728 EXT4_FEATURE_RO_COMPAT_FUNCS(gdt_csum,		GDT_CSUM)
1729 EXT4_FEATURE_RO_COMPAT_FUNCS(dir_nlink,		DIR_NLINK)
1730 EXT4_FEATURE_RO_COMPAT_FUNCS(extra_isize,	EXTRA_ISIZE)
1731 EXT4_FEATURE_RO_COMPAT_FUNCS(quota,		QUOTA)
1732 EXT4_FEATURE_RO_COMPAT_FUNCS(bigalloc,		BIGALLOC)
1733 EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum,	METADATA_CSUM)
1734 EXT4_FEATURE_RO_COMPAT_FUNCS(readonly,		READONLY)
1735 EXT4_FEATURE_RO_COMPAT_FUNCS(project,		PROJECT)
1736 
1737 EXT4_FEATURE_INCOMPAT_FUNCS(compression,	COMPRESSION)
1738 EXT4_FEATURE_INCOMPAT_FUNCS(filetype,		FILETYPE)
1739 EXT4_FEATURE_INCOMPAT_FUNCS(journal_needs_recovery,	RECOVER)
1740 EXT4_FEATURE_INCOMPAT_FUNCS(journal_dev,	JOURNAL_DEV)
1741 EXT4_FEATURE_INCOMPAT_FUNCS(meta_bg,		META_BG)
1742 EXT4_FEATURE_INCOMPAT_FUNCS(extents,		EXTENTS)
1743 EXT4_FEATURE_INCOMPAT_FUNCS(64bit,		64BIT)
1744 EXT4_FEATURE_INCOMPAT_FUNCS(mmp,		MMP)
1745 EXT4_FEATURE_INCOMPAT_FUNCS(flex_bg,		FLEX_BG)
1746 EXT4_FEATURE_INCOMPAT_FUNCS(ea_inode,		EA_INODE)
1747 EXT4_FEATURE_INCOMPAT_FUNCS(dirdata,		DIRDATA)
1748 EXT4_FEATURE_INCOMPAT_FUNCS(csum_seed,		CSUM_SEED)
1749 EXT4_FEATURE_INCOMPAT_FUNCS(largedir,		LARGEDIR)
1750 EXT4_FEATURE_INCOMPAT_FUNCS(inline_data,	INLINE_DATA)
1751 EXT4_FEATURE_INCOMPAT_FUNCS(encrypt,		ENCRYPT)
1752 
1753 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1754 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1755 					 EXT4_FEATURE_INCOMPAT_META_BG)
1756 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1757 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1758 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1759 
1760 #define EXT3_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1761 #define EXT3_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1762 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1763 					 EXT4_FEATURE_INCOMPAT_META_BG)
1764 #define EXT3_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1765 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1766 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1767 
1768 #define EXT4_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1769 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1770 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1771 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1772 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1773 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1774 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1775 					 EXT4_FEATURE_INCOMPAT_EA_INODE| \
1776 					 EXT4_FEATURE_INCOMPAT_MMP | \
1777 					 EXT4_FEATURE_INCOMPAT_INLINE_DATA | \
1778 					 EXT4_FEATURE_INCOMPAT_ENCRYPT | \
1779 					 EXT4_FEATURE_INCOMPAT_CSUM_SEED | \
1780 					 EXT4_FEATURE_INCOMPAT_LARGEDIR)
1781 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1782 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1783 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1784 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1785 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1786 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1787 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1788 					 EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1789 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1790 					 EXT4_FEATURE_RO_COMPAT_QUOTA |\
1791 					 EXT4_FEATURE_RO_COMPAT_PROJECT)
1792 
1793 #define EXTN_FEATURE_FUNCS(ver) \
1794 static inline bool ext4_has_unknown_ext##ver##_compat_features(struct super_block *sb) \
1795 { \
1796 	return ((EXT4_SB(sb)->s_es->s_feature_compat & \
1797 		cpu_to_le32(~EXT##ver##_FEATURE_COMPAT_SUPP)) != 0); \
1798 } \
1799 static inline bool ext4_has_unknown_ext##ver##_ro_compat_features(struct super_block *sb) \
1800 { \
1801 	return ((EXT4_SB(sb)->s_es->s_feature_ro_compat & \
1802 		cpu_to_le32(~EXT##ver##_FEATURE_RO_COMPAT_SUPP)) != 0); \
1803 } \
1804 static inline bool ext4_has_unknown_ext##ver##_incompat_features(struct super_block *sb) \
1805 { \
1806 	return ((EXT4_SB(sb)->s_es->s_feature_incompat & \
1807 		cpu_to_le32(~EXT##ver##_FEATURE_INCOMPAT_SUPP)) != 0); \
1808 }
1809 
1810 EXTN_FEATURE_FUNCS(2)
1811 EXTN_FEATURE_FUNCS(3)
1812 EXTN_FEATURE_FUNCS(4)
1813 
1814 static inline bool ext4_has_compat_features(struct super_block *sb)
1815 {
1816 	return (EXT4_SB(sb)->s_es->s_feature_compat != 0);
1817 }
1818 static inline bool ext4_has_ro_compat_features(struct super_block *sb)
1819 {
1820 	return (EXT4_SB(sb)->s_es->s_feature_ro_compat != 0);
1821 }
1822 static inline bool ext4_has_incompat_features(struct super_block *sb)
1823 {
1824 	return (EXT4_SB(sb)->s_es->s_feature_incompat != 0);
1825 }
1826 
1827 /*
1828  * Superblock flags
1829  */
1830 #define EXT4_FLAGS_RESIZING	0
1831 #define EXT4_FLAGS_SHUTDOWN	1
1832 
1833 static inline int ext4_forced_shutdown(struct ext4_sb_info *sbi)
1834 {
1835 	return test_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);
1836 }
1837 
1838 
1839 /*
1840  * Default values for user and/or group using reserved blocks
1841  */
1842 #define	EXT4_DEF_RESUID		0
1843 #define	EXT4_DEF_RESGID		0
1844 
1845 /*
1846  * Default project ID
1847  */
1848 #define	EXT4_DEF_PROJID		0
1849 
1850 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1851 
1852 /*
1853  * Default mount options
1854  */
1855 #define EXT4_DEFM_DEBUG		0x0001
1856 #define EXT4_DEFM_BSDGROUPS	0x0002
1857 #define EXT4_DEFM_XATTR_USER	0x0004
1858 #define EXT4_DEFM_ACL		0x0008
1859 #define EXT4_DEFM_UID16		0x0010
1860 #define EXT4_DEFM_JMODE		0x0060
1861 #define EXT4_DEFM_JMODE_DATA	0x0020
1862 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1863 #define EXT4_DEFM_JMODE_WBACK	0x0060
1864 #define EXT4_DEFM_NOBARRIER	0x0100
1865 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1866 #define EXT4_DEFM_DISCARD	0x0400
1867 #define EXT4_DEFM_NODELALLOC	0x0800
1868 
1869 /*
1870  * Default journal batch times
1871  */
1872 #define EXT4_DEF_MIN_BATCH_TIME	0
1873 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1874 
1875 /*
1876  * Minimum number of groups in a flexgroup before we separate out
1877  * directories into the first block group of a flexgroup
1878  */
1879 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1880 
1881 /*
1882  * Structure of a directory entry
1883  */
1884 #define EXT4_NAME_LEN 255
1885 
1886 struct ext4_dir_entry {
1887 	__le32	inode;			/* Inode number */
1888 	__le16	rec_len;		/* Directory entry length */
1889 	__le16	name_len;		/* Name length */
1890 	char	name[EXT4_NAME_LEN];	/* File name */
1891 };
1892 
1893 /*
1894  * The new version of the directory entry.  Since EXT4 structures are
1895  * stored in intel byte order, and the name_len field could never be
1896  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1897  * file_type field.
1898  */
1899 struct ext4_dir_entry_2 {
1900 	__le32	inode;			/* Inode number */
1901 	__le16	rec_len;		/* Directory entry length */
1902 	__u8	name_len;		/* Name length */
1903 	__u8	file_type;
1904 	char	name[EXT4_NAME_LEN];	/* File name */
1905 };
1906 
1907 /*
1908  * This is a bogus directory entry at the end of each leaf block that
1909  * records checksums.
1910  */
1911 struct ext4_dir_entry_tail {
1912 	__le32	det_reserved_zero1;	/* Pretend to be unused */
1913 	__le16	det_rec_len;		/* 12 */
1914 	__u8	det_reserved_zero2;	/* Zero name length */
1915 	__u8	det_reserved_ft;	/* 0xDE, fake file type */
1916 	__le32	det_checksum;		/* crc32c(uuid+inum+dirblock) */
1917 };
1918 
1919 #define EXT4_DIRENT_TAIL(block, blocksize) \
1920 	((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1921 					((blocksize) - \
1922 					 sizeof(struct ext4_dir_entry_tail))))
1923 
1924 /*
1925  * Ext4 directory file types.  Only the low 3 bits are used.  The
1926  * other bits are reserved for now.
1927  */
1928 #define EXT4_FT_UNKNOWN		0
1929 #define EXT4_FT_REG_FILE	1
1930 #define EXT4_FT_DIR		2
1931 #define EXT4_FT_CHRDEV		3
1932 #define EXT4_FT_BLKDEV		4
1933 #define EXT4_FT_FIFO		5
1934 #define EXT4_FT_SOCK		6
1935 #define EXT4_FT_SYMLINK		7
1936 
1937 #define EXT4_FT_MAX		8
1938 
1939 #define EXT4_FT_DIR_CSUM	0xDE
1940 
1941 /*
1942  * EXT4_DIR_PAD defines the directory entries boundaries
1943  *
1944  * NOTE: It must be a multiple of 4
1945  */
1946 #define EXT4_DIR_PAD			4
1947 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1948 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1949 					 ~EXT4_DIR_ROUND)
1950 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1951 
1952 /*
1953  * If we ever get support for fs block sizes > page_size, we'll need
1954  * to remove the #if statements in the next two functions...
1955  */
1956 static inline unsigned int
1957 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1958 {
1959 	unsigned len = le16_to_cpu(dlen);
1960 
1961 #if (PAGE_SIZE >= 65536)
1962 	if (len == EXT4_MAX_REC_LEN || len == 0)
1963 		return blocksize;
1964 	return (len & 65532) | ((len & 3) << 16);
1965 #else
1966 	return len;
1967 #endif
1968 }
1969 
1970 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1971 {
1972 	if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1973 		BUG();
1974 #if (PAGE_SIZE >= 65536)
1975 	if (len < 65536)
1976 		return cpu_to_le16(len);
1977 	if (len == blocksize) {
1978 		if (blocksize == 65536)
1979 			return cpu_to_le16(EXT4_MAX_REC_LEN);
1980 		else
1981 			return cpu_to_le16(0);
1982 	}
1983 	return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1984 #else
1985 	return cpu_to_le16(len);
1986 #endif
1987 }
1988 
1989 /*
1990  * Hash Tree Directory indexing
1991  * (c) Daniel Phillips, 2001
1992  */
1993 
1994 #define is_dx(dir) (ext4_has_feature_dir_index((dir)->i_sb) && \
1995 		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1996 #define EXT4_DIR_LINK_MAX(dir) unlikely((dir)->i_nlink >= EXT4_LINK_MAX && \
1997 		    !(ext4_has_feature_dir_nlink((dir)->i_sb) && is_dx(dir)))
1998 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1999 
2000 /* Legal values for the dx_root hash_version field: */
2001 
2002 #define DX_HASH_LEGACY			0
2003 #define DX_HASH_HALF_MD4		1
2004 #define DX_HASH_TEA			2
2005 #define DX_HASH_LEGACY_UNSIGNED		3
2006 #define DX_HASH_HALF_MD4_UNSIGNED	4
2007 #define DX_HASH_TEA_UNSIGNED		5
2008 
2009 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
2010 			      const void *address, unsigned int length)
2011 {
2012 	struct {
2013 		struct shash_desc shash;
2014 		char ctx[4];
2015 	} desc;
2016 
2017 	BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
2018 
2019 	desc.shash.tfm = sbi->s_chksum_driver;
2020 	desc.shash.flags = 0;
2021 	*(u32 *)desc.ctx = crc;
2022 
2023 	BUG_ON(crypto_shash_update(&desc.shash, address, length));
2024 
2025 	return *(u32 *)desc.ctx;
2026 }
2027 
2028 #ifdef __KERNEL__
2029 
2030 /* hash info structure used by the directory hash */
2031 struct dx_hash_info
2032 {
2033 	u32		hash;
2034 	u32		minor_hash;
2035 	int		hash_version;
2036 	u32		*seed;
2037 };
2038 
2039 
2040 /* 32 and 64 bit signed EOF for dx directories */
2041 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
2042 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
2043 
2044 
2045 /*
2046  * Control parameters used by ext4_htree_next_block
2047  */
2048 #define HASH_NB_ALWAYS		1
2049 
2050 struct ext4_filename {
2051 	const struct qstr *usr_fname;
2052 	struct fscrypt_str disk_name;
2053 	struct dx_hash_info hinfo;
2054 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2055 	struct fscrypt_str crypto_buf;
2056 #endif
2057 };
2058 
2059 #define fname_name(p) ((p)->disk_name.name)
2060 #define fname_len(p)  ((p)->disk_name.len)
2061 
2062 /*
2063  * Describe an inode's exact location on disk and in memory
2064  */
2065 struct ext4_iloc
2066 {
2067 	struct buffer_head *bh;
2068 	unsigned long offset;
2069 	ext4_group_t block_group;
2070 };
2071 
2072 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
2073 {
2074 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
2075 }
2076 
2077 static inline bool ext4_is_quota_file(struct inode *inode)
2078 {
2079 	return IS_NOQUOTA(inode) &&
2080 	       !(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL);
2081 }
2082 
2083 /*
2084  * This structure is stuffed into the struct file's private_data field
2085  * for directories.  It is where we put information so that we can do
2086  * readdir operations in hash tree order.
2087  */
2088 struct dir_private_info {
2089 	struct rb_root	root;
2090 	struct rb_node	*curr_node;
2091 	struct fname	*extra_fname;
2092 	loff_t		last_pos;
2093 	__u32		curr_hash;
2094 	__u32		curr_minor_hash;
2095 	__u32		next_hash;
2096 };
2097 
2098 /* calculate the first block number of the group */
2099 static inline ext4_fsblk_t
2100 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
2101 {
2102 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
2103 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
2104 }
2105 
2106 /*
2107  * Special error return code only used by dx_probe() and its callers.
2108  */
2109 #define ERR_BAD_DX_DIR	(-(MAX_ERRNO - 1))
2110 
2111 /* htree levels for ext4 */
2112 #define	EXT4_HTREE_LEVEL_COMPAT	2
2113 #define	EXT4_HTREE_LEVEL	3
2114 
2115 static inline int ext4_dir_htree_level(struct super_block *sb)
2116 {
2117 	return ext4_has_feature_largedir(sb) ?
2118 		EXT4_HTREE_LEVEL : EXT4_HTREE_LEVEL_COMPAT;
2119 }
2120 
2121 /*
2122  * Timeout and state flag for lazy initialization inode thread.
2123  */
2124 #define EXT4_DEF_LI_WAIT_MULT			10
2125 #define EXT4_DEF_LI_MAX_START_DELAY		5
2126 #define EXT4_LAZYINIT_QUIT			0x0001
2127 #define EXT4_LAZYINIT_RUNNING			0x0002
2128 
2129 /*
2130  * Lazy inode table initialization info
2131  */
2132 struct ext4_lazy_init {
2133 	unsigned long		li_state;
2134 	struct list_head	li_request_list;
2135 	struct mutex		li_list_mtx;
2136 };
2137 
2138 struct ext4_li_request {
2139 	struct super_block	*lr_super;
2140 	struct ext4_sb_info	*lr_sbi;
2141 	ext4_group_t		lr_next_group;
2142 	struct list_head	lr_request;
2143 	unsigned long		lr_next_sched;
2144 	unsigned long		lr_timeout;
2145 };
2146 
2147 struct ext4_features {
2148 	struct kobject f_kobj;
2149 	struct completion f_kobj_unregister;
2150 };
2151 
2152 /*
2153  * This structure will be used for multiple mount protection. It will be
2154  * written into the block number saved in the s_mmp_block field in the
2155  * superblock. Programs that check MMP should assume that if
2156  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
2157  * to use the filesystem, regardless of how old the timestamp is.
2158  */
2159 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
2160 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
2161 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
2162 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
2163 
2164 struct mmp_struct {
2165 	__le32	mmp_magic;		/* Magic number for MMP */
2166 	__le32	mmp_seq;		/* Sequence no. updated periodically */
2167 
2168 	/*
2169 	 * mmp_time, mmp_nodename & mmp_bdevname are only used for information
2170 	 * purposes and do not affect the correctness of the algorithm
2171 	 */
2172 	__le64	mmp_time;		/* Time last updated */
2173 	char	mmp_nodename[64];	/* Node which last updated MMP block */
2174 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
2175 
2176 	/*
2177 	 * mmp_check_interval is used to verify if the MMP block has been
2178 	 * updated on the block device. The value is updated based on the
2179 	 * maximum time to write the MMP block during an update cycle.
2180 	 */
2181 	__le16	mmp_check_interval;
2182 
2183 	__le16	mmp_pad1;
2184 	__le32	mmp_pad2[226];
2185 	__le32	mmp_checksum;		/* crc32c(uuid+mmp_block) */
2186 };
2187 
2188 /* arguments passed to the mmp thread */
2189 struct mmpd_data {
2190 	struct buffer_head *bh; /* bh from initial read_mmp_block() */
2191 	struct super_block *sb;  /* super block of the fs */
2192 };
2193 
2194 /*
2195  * Check interval multiplier
2196  * The MMP block is written every update interval and initially checked every
2197  * update interval x the multiplier (the value is then adapted based on the
2198  * write latency). The reason is that writes can be delayed under load and we
2199  * don't want readers to incorrectly assume that the filesystem is no longer
2200  * in use.
2201  */
2202 #define EXT4_MMP_CHECK_MULT		2UL
2203 
2204 /*
2205  * Minimum interval for MMP checking in seconds.
2206  */
2207 #define EXT4_MMP_MIN_CHECK_INTERVAL	5UL
2208 
2209 /*
2210  * Maximum interval for MMP checking in seconds.
2211  */
2212 #define EXT4_MMP_MAX_CHECK_INTERVAL	300UL
2213 
2214 /*
2215  * Function prototypes
2216  */
2217 
2218 /*
2219  * Ok, these declarations are also in <linux/kernel.h> but none of the
2220  * ext4 source programs needs to include it so they are duplicated here.
2221  */
2222 # define NORET_TYPE	/**/
2223 # define ATTRIB_NORET	__attribute__((noreturn))
2224 # define NORET_AND	noreturn,
2225 
2226 /* bitmap.c */
2227 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
2228 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
2229 				struct ext4_group_desc *gdp,
2230 				struct buffer_head *bh, int sz);
2231 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
2232 				  struct ext4_group_desc *gdp,
2233 				  struct buffer_head *bh, int sz);
2234 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
2235 				struct ext4_group_desc *gdp,
2236 				struct buffer_head *bh);
2237 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
2238 				  struct ext4_group_desc *gdp,
2239 				  struct buffer_head *bh);
2240 
2241 /* balloc.c */
2242 extern void ext4_get_group_no_and_offset(struct super_block *sb,
2243 					 ext4_fsblk_t blocknr,
2244 					 ext4_group_t *blockgrpp,
2245 					 ext4_grpblk_t *offsetp);
2246 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
2247 					  ext4_fsblk_t block);
2248 
2249 extern unsigned int ext4_block_group(struct super_block *sb,
2250 			ext4_fsblk_t blocknr);
2251 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
2252 			ext4_fsblk_t blocknr);
2253 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
2254 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
2255 			ext4_group_t group);
2256 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
2257 					 ext4_fsblk_t goal,
2258 					 unsigned int flags,
2259 					 unsigned long *count,
2260 					 int *errp);
2261 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
2262 				    s64 nclusters, unsigned int flags);
2263 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
2264 extern void ext4_check_blocks_bitmap(struct super_block *);
2265 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
2266 						    ext4_group_t block_group,
2267 						    struct buffer_head ** bh);
2268 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
2269 
2270 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
2271 						ext4_group_t block_group);
2272 extern int ext4_wait_block_bitmap(struct super_block *sb,
2273 				  ext4_group_t block_group,
2274 				  struct buffer_head *bh);
2275 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
2276 						  ext4_group_t block_group);
2277 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
2278 					      ext4_group_t block_group,
2279 					      struct ext4_group_desc *gdp);
2280 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
2281 
2282 static inline bool ext4_encrypted_inode(struct inode *inode)
2283 {
2284 	return ext4_test_inode_flag(inode, EXT4_INODE_ENCRYPT);
2285 }
2286 
2287 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2288 static inline int ext4_fname_setup_filename(struct inode *dir,
2289 			const struct qstr *iname,
2290 			int lookup, struct ext4_filename *fname)
2291 {
2292 	struct fscrypt_name name;
2293 	int err;
2294 
2295 	memset(fname, 0, sizeof(struct ext4_filename));
2296 
2297 	err = fscrypt_setup_filename(dir, iname, lookup, &name);
2298 
2299 	fname->usr_fname = name.usr_fname;
2300 	fname->disk_name = name.disk_name;
2301 	fname->hinfo.hash = name.hash;
2302 	fname->hinfo.minor_hash = name.minor_hash;
2303 	fname->crypto_buf = name.crypto_buf;
2304 	return err;
2305 }
2306 
2307 static inline void ext4_fname_free_filename(struct ext4_filename *fname)
2308 {
2309 	struct fscrypt_name name;
2310 
2311 	name.crypto_buf = fname->crypto_buf;
2312 	fscrypt_free_filename(&name);
2313 
2314 	fname->crypto_buf.name = NULL;
2315 	fname->usr_fname = NULL;
2316 	fname->disk_name.name = NULL;
2317 }
2318 #else
2319 static inline int ext4_fname_setup_filename(struct inode *dir,
2320 		const struct qstr *iname,
2321 		int lookup, struct ext4_filename *fname)
2322 {
2323 	fname->usr_fname = iname;
2324 	fname->disk_name.name = (unsigned char *) iname->name;
2325 	fname->disk_name.len = iname->len;
2326 	return 0;
2327 }
2328 static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
2329 
2330 #endif
2331 
2332 /* dir.c */
2333 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
2334 				  struct file *,
2335 				  struct ext4_dir_entry_2 *,
2336 				  struct buffer_head *, char *, int,
2337 				  unsigned int);
2338 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)	\
2339 	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
2340 					(de), (bh), (buf), (size), (offset)))
2341 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
2342 				__u32 minor_hash,
2343 				struct ext4_dir_entry_2 *dirent,
2344 				struct fscrypt_str *ent_name);
2345 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
2346 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
2347 			     struct buffer_head *bh,
2348 			     void *buf, int buf_size,
2349 			     struct ext4_filename *fname,
2350 			     struct ext4_dir_entry_2 **dest_de);
2351 void ext4_insert_dentry(struct inode *inode,
2352 			struct ext4_dir_entry_2 *de,
2353 			int buf_size,
2354 			struct ext4_filename *fname);
2355 static inline void ext4_update_dx_flag(struct inode *inode)
2356 {
2357 	if (!ext4_has_feature_dir_index(inode->i_sb))
2358 		ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
2359 }
2360 static const unsigned char ext4_filetype_table[] = {
2361 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
2362 };
2363 
2364 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
2365 {
2366 	if (!ext4_has_feature_filetype(sb) || filetype >= EXT4_FT_MAX)
2367 		return DT_UNKNOWN;
2368 
2369 	return ext4_filetype_table[filetype];
2370 }
2371 extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
2372 			     void *buf, int buf_size);
2373 
2374 /* fsync.c */
2375 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2376 
2377 /* hash.c */
2378 extern int ext4fs_dirhash(const char *name, int len, struct
2379 			  dx_hash_info *hinfo);
2380 
2381 /* ialloc.c */
2382 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
2383 				      const struct qstr *qstr, __u32 goal,
2384 				      uid_t *owner, __u32 i_flags,
2385 				      int handle_type, unsigned int line_no,
2386 				      int nblocks);
2387 
2388 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner, i_flags) \
2389 	__ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
2390 			 i_flags, 0, 0, 0)
2391 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
2392 				    type, nblocks)		    \
2393 	__ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
2394 			 0, (type), __LINE__, (nblocks))
2395 
2396 
2397 extern void ext4_free_inode(handle_t *, struct inode *);
2398 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2399 extern unsigned long ext4_count_free_inodes(struct super_block *);
2400 extern unsigned long ext4_count_dirs(struct super_block *);
2401 extern void ext4_check_inodes_bitmap(struct super_block *);
2402 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2403 extern int ext4_init_inode_table(struct super_block *sb,
2404 				 ext4_group_t group, int barrier);
2405 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2406 
2407 /* mballoc.c */
2408 extern const struct seq_operations ext4_mb_seq_groups_ops;
2409 extern long ext4_mb_stats;
2410 extern long ext4_mb_max_to_scan;
2411 extern int ext4_mb_init(struct super_block *);
2412 extern int ext4_mb_release(struct super_block *);
2413 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2414 				struct ext4_allocation_request *, int *);
2415 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2416 extern void ext4_discard_preallocations(struct inode *);
2417 extern int __init ext4_init_mballoc(void);
2418 extern void ext4_exit_mballoc(void);
2419 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2420 			     struct buffer_head *bh, ext4_fsblk_t block,
2421 			     unsigned long count, int flags);
2422 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2423 				   ext4_group_t ngroups);
2424 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2425 		ext4_group_t i, struct ext4_group_desc *desc);
2426 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2427 				ext4_fsblk_t block, unsigned long count);
2428 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2429 extern void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid);
2430 
2431 /* inode.c */
2432 int ext4_inode_is_fast_symlink(struct inode *inode);
2433 struct buffer_head *ext4_getblk(handle_t *, struct inode *, ext4_lblk_t, int);
2434 struct buffer_head *ext4_bread(handle_t *, struct inode *, ext4_lblk_t, int);
2435 int ext4_bread_batch(struct inode *inode, ext4_lblk_t block, int bh_count,
2436 		     bool wait, struct buffer_head **bhs);
2437 int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
2438 			     struct buffer_head *bh_result, int create);
2439 int ext4_get_block(struct inode *inode, sector_t iblock,
2440 		   struct buffer_head *bh_result, int create);
2441 int ext4_dio_get_block(struct inode *inode, sector_t iblock,
2442 		       struct buffer_head *bh_result, int create);
2443 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2444 			   struct buffer_head *bh, int create);
2445 int ext4_walk_page_buffers(handle_t *handle,
2446 			   struct buffer_head *head,
2447 			   unsigned from,
2448 			   unsigned to,
2449 			   int *partial,
2450 			   int (*fn)(handle_t *handle,
2451 				     struct buffer_head *bh));
2452 int do_journal_get_write_access(handle_t *handle,
2453 				struct buffer_head *bh);
2454 #define FALL_BACK_TO_NONDELALLOC 1
2455 #define CONVERT_INLINE_DATA	 2
2456 
2457 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2458 extern struct inode *ext4_iget_normal(struct super_block *, unsigned long);
2459 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2460 extern int  ext4_setattr(struct dentry *, struct iattr *);
2461 extern int  ext4_getattr(const struct path *, struct kstat *, u32, unsigned int);
2462 extern void ext4_evict_inode(struct inode *);
2463 extern void ext4_clear_inode(struct inode *);
2464 extern int  ext4_file_getattr(const struct path *, struct kstat *, u32, unsigned int);
2465 extern int  ext4_sync_inode(handle_t *, struct inode *);
2466 extern void ext4_dirty_inode(struct inode *, int);
2467 extern int ext4_change_inode_journal_flag(struct inode *, int);
2468 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2469 extern int ext4_inode_attach_jinode(struct inode *inode);
2470 extern int ext4_can_truncate(struct inode *inode);
2471 extern int ext4_truncate(struct inode *);
2472 extern int ext4_break_layouts(struct inode *);
2473 extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length);
2474 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2475 extern void ext4_set_inode_flags(struct inode *);
2476 extern int ext4_alloc_da_blocks(struct inode *inode);
2477 extern void ext4_set_aops(struct inode *inode);
2478 extern int ext4_writepage_trans_blocks(struct inode *);
2479 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2480 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
2481 			     loff_t lstart, loff_t lend);
2482 extern vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf);
2483 extern vm_fault_t ext4_filemap_fault(struct vm_fault *vmf);
2484 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2485 extern int ext4_get_projid(struct inode *inode, kprojid_t *projid);
2486 extern void ext4_da_release_space(struct inode *inode, int to_free);
2487 extern void ext4_da_update_reserve_space(struct inode *inode,
2488 					int used, int quota_claim);
2489 extern int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk,
2490 			      ext4_fsblk_t pblk, ext4_lblk_t len);
2491 
2492 /* indirect.c */
2493 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2494 				struct ext4_map_blocks *map, int flags);
2495 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2496 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2497 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2498 extern int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
2499 				 ext4_lblk_t start, ext4_lblk_t end);
2500 
2501 /* ioctl.c */
2502 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2503 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2504 
2505 /* migrate.c */
2506 extern int ext4_ext_migrate(struct inode *);
2507 extern int ext4_ind_migrate(struct inode *inode);
2508 
2509 /* namei.c */
2510 extern int ext4_dirent_csum_verify(struct inode *inode,
2511 				   struct ext4_dir_entry *dirent);
2512 extern int ext4_orphan_add(handle_t *, struct inode *);
2513 extern int ext4_orphan_del(handle_t *, struct inode *);
2514 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2515 				__u32 start_minor_hash, __u32 *next_hash);
2516 extern int ext4_search_dir(struct buffer_head *bh,
2517 			   char *search_buf,
2518 			   int buf_size,
2519 			   struct inode *dir,
2520 			   struct ext4_filename *fname,
2521 			   unsigned int offset,
2522 			   struct ext4_dir_entry_2 **res_dir);
2523 extern int ext4_generic_delete_entry(handle_t *handle,
2524 				     struct inode *dir,
2525 				     struct ext4_dir_entry_2 *de_del,
2526 				     struct buffer_head *bh,
2527 				     void *entry_buf,
2528 				     int buf_size,
2529 				     int csum_size);
2530 extern bool ext4_empty_dir(struct inode *inode);
2531 
2532 /* resize.c */
2533 extern int ext4_group_add(struct super_block *sb,
2534 				struct ext4_new_group_data *input);
2535 extern int ext4_group_extend(struct super_block *sb,
2536 				struct ext4_super_block *es,
2537 				ext4_fsblk_t n_blocks_count);
2538 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2539 
2540 /* super.c */
2541 extern int ext4_seq_options_show(struct seq_file *seq, void *offset);
2542 extern int ext4_calculate_overhead(struct super_block *sb);
2543 extern void ext4_superblock_csum_set(struct super_block *sb);
2544 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2545 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2546 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2547 				    ext4_group_t ngroup);
2548 extern const char *ext4_decode_error(struct super_block *sb, int errno,
2549 				     char nbuf[16]);
2550 extern void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
2551 					     ext4_group_t block_group,
2552 					     unsigned int flags);
2553 
2554 extern __printf(4, 5)
2555 void __ext4_error(struct super_block *, const char *, unsigned int,
2556 		  const char *, ...);
2557 extern __printf(5, 6)
2558 void __ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2559 		      const char *, ...);
2560 extern __printf(5, 6)
2561 void __ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2562 		     const char *, ...);
2563 extern void __ext4_std_error(struct super_block *, const char *,
2564 			     unsigned int, int);
2565 extern __printf(4, 5)
2566 void __ext4_abort(struct super_block *, const char *, unsigned int,
2567 		  const char *, ...);
2568 extern __printf(4, 5)
2569 void __ext4_warning(struct super_block *, const char *, unsigned int,
2570 		    const char *, ...);
2571 extern __printf(4, 5)
2572 void __ext4_warning_inode(const struct inode *inode, const char *function,
2573 			  unsigned int line, const char *fmt, ...);
2574 extern __printf(3, 4)
2575 void __ext4_msg(struct super_block *, const char *, const char *, ...);
2576 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2577 			   const char *, unsigned int, const char *);
2578 extern __printf(7, 8)
2579 void __ext4_grp_locked_error(const char *, unsigned int,
2580 			     struct super_block *, ext4_group_t,
2581 			     unsigned long, ext4_fsblk_t,
2582 			     const char *, ...);
2583 
2584 #define EXT4_ERROR_INODE(inode, fmt, a...) \
2585 	ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
2586 
2587 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)			\
2588 	ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
2589 
2590 #define EXT4_ERROR_FILE(file, block, fmt, a...)				\
2591 	ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
2592 
2593 #ifdef CONFIG_PRINTK
2594 
2595 #define ext4_error_inode(inode, func, line, block, fmt, ...)		\
2596 	__ext4_error_inode(inode, func, line, block, fmt, ##__VA_ARGS__)
2597 #define ext4_error_file(file, func, line, block, fmt, ...)		\
2598 	__ext4_error_file(file, func, line, block, fmt, ##__VA_ARGS__)
2599 #define ext4_error(sb, fmt, ...)					\
2600 	__ext4_error(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2601 #define ext4_abort(sb, fmt, ...)					\
2602 	__ext4_abort(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2603 #define ext4_warning(sb, fmt, ...)					\
2604 	__ext4_warning(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2605 #define ext4_warning_inode(inode, fmt, ...)				\
2606 	__ext4_warning_inode(inode, __func__, __LINE__, fmt, ##__VA_ARGS__)
2607 #define ext4_msg(sb, level, fmt, ...)				\
2608 	__ext4_msg(sb, level, fmt, ##__VA_ARGS__)
2609 #define dump_mmp_msg(sb, mmp, msg)					\
2610 	__dump_mmp_msg(sb, mmp, __func__, __LINE__, msg)
2611 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)		\
2612 	__ext4_grp_locked_error(__func__, __LINE__, sb, grp, ino, block, \
2613 				fmt, ##__VA_ARGS__)
2614 
2615 #else
2616 
2617 #define ext4_error_inode(inode, func, line, block, fmt, ...)		\
2618 do {									\
2619 	no_printk(fmt, ##__VA_ARGS__);					\
2620 	__ext4_error_inode(inode, "", 0, block, " ");			\
2621 } while (0)
2622 #define ext4_error_file(file, func, line, block, fmt, ...)		\
2623 do {									\
2624 	no_printk(fmt, ##__VA_ARGS__);					\
2625 	__ext4_error_file(file, "", 0, block, " ");			\
2626 } while (0)
2627 #define ext4_error(sb, fmt, ...)					\
2628 do {									\
2629 	no_printk(fmt, ##__VA_ARGS__);					\
2630 	__ext4_error(sb, "", 0, " ");					\
2631 } while (0)
2632 #define ext4_abort(sb, fmt, ...)					\
2633 do {									\
2634 	no_printk(fmt, ##__VA_ARGS__);					\
2635 	__ext4_abort(sb, "", 0, " ");					\
2636 } while (0)
2637 #define ext4_warning(sb, fmt, ...)					\
2638 do {									\
2639 	no_printk(fmt, ##__VA_ARGS__);					\
2640 	__ext4_warning(sb, "", 0, " ");					\
2641 } while (0)
2642 #define ext4_warning_inode(inode, fmt, ...)				\
2643 do {									\
2644 	no_printk(fmt, ##__VA_ARGS__);					\
2645 	__ext4_warning_inode(inode, "", 0, " ");			\
2646 } while (0)
2647 #define ext4_msg(sb, level, fmt, ...)					\
2648 do {									\
2649 	no_printk(fmt, ##__VA_ARGS__);					\
2650 	__ext4_msg(sb, "", " ");					\
2651 } while (0)
2652 #define dump_mmp_msg(sb, mmp, msg)					\
2653 	__dump_mmp_msg(sb, mmp, "", 0, "")
2654 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)		\
2655 do {									\
2656 	no_printk(fmt, ##__VA_ARGS__);				\
2657 	__ext4_grp_locked_error("", 0, sb, grp, ino, block, " ");	\
2658 } while (0)
2659 
2660 #endif
2661 
2662 extern void ext4_update_dynamic_rev(struct super_block *sb);
2663 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2664 					__u32 compat);
2665 extern int ext4_update_rocompat_feature(handle_t *handle,
2666 					struct super_block *sb,	__u32 rocompat);
2667 extern int ext4_update_incompat_feature(handle_t *handle,
2668 					struct super_block *sb,	__u32 incompat);
2669 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2670 				      struct ext4_group_desc *bg);
2671 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2672 				      struct ext4_group_desc *bg);
2673 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2674 				     struct ext4_group_desc *bg);
2675 extern __u32 ext4_free_group_clusters(struct super_block *sb,
2676 				      struct ext4_group_desc *bg);
2677 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2678 				 struct ext4_group_desc *bg);
2679 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2680 				struct ext4_group_desc *bg);
2681 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2682 				   struct ext4_group_desc *bg);
2683 extern void ext4_block_bitmap_set(struct super_block *sb,
2684 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2685 extern void ext4_inode_bitmap_set(struct super_block *sb,
2686 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2687 extern void ext4_inode_table_set(struct super_block *sb,
2688 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
2689 extern void ext4_free_group_clusters_set(struct super_block *sb,
2690 					 struct ext4_group_desc *bg,
2691 					 __u32 count);
2692 extern void ext4_free_inodes_set(struct super_block *sb,
2693 				struct ext4_group_desc *bg, __u32 count);
2694 extern void ext4_used_dirs_set(struct super_block *sb,
2695 				struct ext4_group_desc *bg, __u32 count);
2696 extern void ext4_itable_unused_set(struct super_block *sb,
2697 				   struct ext4_group_desc *bg, __u32 count);
2698 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2699 				       struct ext4_group_desc *gdp);
2700 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2701 				     struct ext4_group_desc *gdp);
2702 extern int ext4_register_li_request(struct super_block *sb,
2703 				    ext4_group_t first_not_zeroed);
2704 
2705 static inline int ext4_has_metadata_csum(struct super_block *sb)
2706 {
2707 	WARN_ON_ONCE(ext4_has_feature_metadata_csum(sb) &&
2708 		     !EXT4_SB(sb)->s_chksum_driver);
2709 
2710 	return ext4_has_feature_metadata_csum(sb) &&
2711 	       (EXT4_SB(sb)->s_chksum_driver != NULL);
2712 }
2713 
2714 static inline int ext4_has_group_desc_csum(struct super_block *sb)
2715 {
2716 	return ext4_has_feature_gdt_csum(sb) || ext4_has_metadata_csum(sb);
2717 }
2718 
2719 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2720 {
2721 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2722 		le32_to_cpu(es->s_blocks_count_lo);
2723 }
2724 
2725 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2726 {
2727 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2728 		le32_to_cpu(es->s_r_blocks_count_lo);
2729 }
2730 
2731 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2732 {
2733 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2734 		le32_to_cpu(es->s_free_blocks_count_lo);
2735 }
2736 
2737 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2738 					 ext4_fsblk_t blk)
2739 {
2740 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2741 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2742 }
2743 
2744 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2745 					      ext4_fsblk_t blk)
2746 {
2747 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2748 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2749 }
2750 
2751 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2752 					   ext4_fsblk_t blk)
2753 {
2754 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2755 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2756 }
2757 
2758 static inline loff_t ext4_isize(struct super_block *sb,
2759 				struct ext4_inode *raw_inode)
2760 {
2761 	if (ext4_has_feature_largedir(sb) ||
2762 	    S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2763 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2764 			le32_to_cpu(raw_inode->i_size_lo);
2765 
2766 	return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2767 }
2768 
2769 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2770 {
2771 	raw_inode->i_size_lo = cpu_to_le32(i_size);
2772 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2773 }
2774 
2775 static inline
2776 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2777 					    ext4_group_t group)
2778 {
2779 	 struct ext4_group_info ***grp_info;
2780 	 long indexv, indexh;
2781 	 BUG_ON(group >= EXT4_SB(sb)->s_groups_count);
2782 	 grp_info = EXT4_SB(sb)->s_group_info;
2783 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2784 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2785 	 return grp_info[indexv][indexh];
2786 }
2787 
2788 /*
2789  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2790  * the locking protocol documented in the comments of ext4_group_add()
2791  * in resize.c
2792  */
2793 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2794 {
2795 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
2796 
2797 	smp_rmb();
2798 	return ngroups;
2799 }
2800 
2801 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2802 					     ext4_group_t block_group)
2803 {
2804 	return block_group >> sbi->s_log_groups_per_flex;
2805 }
2806 
2807 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2808 {
2809 	return 1 << sbi->s_log_groups_per_flex;
2810 }
2811 
2812 #define ext4_std_error(sb, errno)				\
2813 do {								\
2814 	if ((errno))						\
2815 		__ext4_std_error((sb), __func__, __LINE__, (errno));	\
2816 } while (0)
2817 
2818 #ifdef CONFIG_SMP
2819 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2820  * counters. So we need to make sure we have free clusters more
2821  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2822  */
2823 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2824 #else
2825 #define EXT4_FREECLUSTERS_WATERMARK 0
2826 #endif
2827 
2828 /* Update i_disksize. Requires i_mutex to avoid races with truncate */
2829 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2830 {
2831 	WARN_ON_ONCE(S_ISREG(inode->i_mode) &&
2832 		     !inode_is_locked(inode));
2833 	down_write(&EXT4_I(inode)->i_data_sem);
2834 	if (newsize > EXT4_I(inode)->i_disksize)
2835 		EXT4_I(inode)->i_disksize = newsize;
2836 	up_write(&EXT4_I(inode)->i_data_sem);
2837 }
2838 
2839 /* Update i_size, i_disksize. Requires i_mutex to avoid races with truncate */
2840 static inline int ext4_update_inode_size(struct inode *inode, loff_t newsize)
2841 {
2842 	int changed = 0;
2843 
2844 	if (newsize > inode->i_size) {
2845 		i_size_write(inode, newsize);
2846 		changed = 1;
2847 	}
2848 	if (newsize > EXT4_I(inode)->i_disksize) {
2849 		ext4_update_i_disksize(inode, newsize);
2850 		changed |= 2;
2851 	}
2852 	return changed;
2853 }
2854 
2855 int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset,
2856 				      loff_t len);
2857 
2858 struct ext4_group_info {
2859 	unsigned long   bb_state;
2860 	struct rb_root  bb_free_root;
2861 	ext4_grpblk_t	bb_first_free;	/* first free block */
2862 	ext4_grpblk_t	bb_free;	/* total free blocks */
2863 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
2864 	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
2865 	struct          list_head bb_prealloc_list;
2866 #ifdef DOUBLE_CHECK
2867 	void            *bb_bitmap;
2868 #endif
2869 	struct rw_semaphore alloc_sem;
2870 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
2871 					 * regions, index is order.
2872 					 * bb_counters[3] = 5 means
2873 					 * 5 free 8-block regions. */
2874 };
2875 
2876 #define EXT4_GROUP_INFO_NEED_INIT_BIT		0
2877 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT		1
2878 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT	2
2879 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT	3
2880 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT		\
2881 	(1 << EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT)
2882 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT		\
2883 	(1 << EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT)
2884 
2885 #define EXT4_MB_GRP_NEED_INIT(grp)	\
2886 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2887 #define EXT4_MB_GRP_BBITMAP_CORRUPT(grp)	\
2888 	(test_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2889 #define EXT4_MB_GRP_IBITMAP_CORRUPT(grp)	\
2890 	(test_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2891 
2892 #define EXT4_MB_GRP_WAS_TRIMMED(grp)	\
2893 	(test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2894 #define EXT4_MB_GRP_SET_TRIMMED(grp)	\
2895 	(set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2896 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)	\
2897 	(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2898 
2899 #define EXT4_MAX_CONTENTION		8
2900 #define EXT4_CONTENTION_THRESHOLD	2
2901 
2902 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2903 					      ext4_group_t group)
2904 {
2905 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2906 }
2907 
2908 /*
2909  * Returns true if the filesystem is busy enough that attempts to
2910  * access the block group locks has run into contention.
2911  */
2912 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2913 {
2914 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2915 }
2916 
2917 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2918 {
2919 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2920 	if (spin_trylock(lock))
2921 		/*
2922 		 * We're able to grab the lock right away, so drop the
2923 		 * lock contention counter.
2924 		 */
2925 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2926 	else {
2927 		/*
2928 		 * The lock is busy, so bump the contention counter,
2929 		 * and then wait on the spin lock.
2930 		 */
2931 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2932 				  EXT4_MAX_CONTENTION);
2933 		spin_lock(lock);
2934 	}
2935 }
2936 
2937 static inline void ext4_unlock_group(struct super_block *sb,
2938 					ext4_group_t group)
2939 {
2940 	spin_unlock(ext4_group_lock_ptr(sb, group));
2941 }
2942 
2943 /*
2944  * Block validity checking
2945  */
2946 #define ext4_check_indirect_blockref(inode, bh)				\
2947 	ext4_check_blockref(__func__, __LINE__, inode,			\
2948 			    (__le32 *)(bh)->b_data,			\
2949 			    EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2950 
2951 #define ext4_ind_check_inode(inode)					\
2952 	ext4_check_blockref(__func__, __LINE__, inode,			\
2953 			    EXT4_I(inode)->i_data,			\
2954 			    EXT4_NDIR_BLOCKS)
2955 
2956 /*
2957  * Inodes and files operations
2958  */
2959 
2960 /* dir.c */
2961 extern const struct file_operations ext4_dir_operations;
2962 
2963 /* file.c */
2964 extern const struct inode_operations ext4_file_inode_operations;
2965 extern const struct file_operations ext4_file_operations;
2966 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2967 
2968 /* inline.c */
2969 extern int ext4_get_max_inline_size(struct inode *inode);
2970 extern int ext4_find_inline_data_nolock(struct inode *inode);
2971 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
2972 				 unsigned int len);
2973 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
2974 
2975 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
2976 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
2977 					 struct inode *inode,
2978 					 loff_t pos, unsigned len,
2979 					 unsigned flags,
2980 					 struct page **pagep);
2981 extern int ext4_write_inline_data_end(struct inode *inode,
2982 				      loff_t pos, unsigned len,
2983 				      unsigned copied,
2984 				      struct page *page);
2985 extern struct buffer_head *
2986 ext4_journalled_write_inline_data(struct inode *inode,
2987 				  unsigned len,
2988 				  struct page *page);
2989 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
2990 					   struct inode *inode,
2991 					   loff_t pos, unsigned len,
2992 					   unsigned flags,
2993 					   struct page **pagep,
2994 					   void **fsdata);
2995 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
2996 					 unsigned len, unsigned copied,
2997 					 struct page *page);
2998 extern int ext4_try_add_inline_entry(handle_t *handle,
2999 				     struct ext4_filename *fname,
3000 				     struct inode *dir, struct inode *inode);
3001 extern int ext4_try_create_inline_dir(handle_t *handle,
3002 				      struct inode *parent,
3003 				      struct inode *inode);
3004 extern int ext4_read_inline_dir(struct file *filp,
3005 				struct dir_context *ctx,
3006 				int *has_inline_data);
3007 extern int htree_inlinedir_to_tree(struct file *dir_file,
3008 				   struct inode *dir, ext4_lblk_t block,
3009 				   struct dx_hash_info *hinfo,
3010 				   __u32 start_hash, __u32 start_minor_hash,
3011 				   int *has_inline_data);
3012 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
3013 					struct ext4_filename *fname,
3014 					struct ext4_dir_entry_2 **res_dir,
3015 					int *has_inline_data);
3016 extern int ext4_delete_inline_entry(handle_t *handle,
3017 				    struct inode *dir,
3018 				    struct ext4_dir_entry_2 *de_del,
3019 				    struct buffer_head *bh,
3020 				    int *has_inline_data);
3021 extern bool empty_inline_dir(struct inode *dir, int *has_inline_data);
3022 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
3023 					struct ext4_dir_entry_2 **parent_de,
3024 					int *retval);
3025 extern int ext4_inline_data_fiemap(struct inode *inode,
3026 				   struct fiemap_extent_info *fieinfo,
3027 				   int *has_inline, __u64 start, __u64 len);
3028 
3029 struct iomap;
3030 extern int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap);
3031 
3032 extern int ext4_inline_data_truncate(struct inode *inode, int *has_inline);
3033 
3034 extern int ext4_convert_inline_data(struct inode *inode);
3035 
3036 static inline int ext4_has_inline_data(struct inode *inode)
3037 {
3038 	return ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA) &&
3039 	       EXT4_I(inode)->i_inline_off;
3040 }
3041 
3042 /* namei.c */
3043 extern const struct inode_operations ext4_dir_inode_operations;
3044 extern const struct inode_operations ext4_special_inode_operations;
3045 extern struct dentry *ext4_get_parent(struct dentry *child);
3046 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
3047 				 struct ext4_dir_entry_2 *de,
3048 				 int blocksize, int csum_size,
3049 				 unsigned int parent_ino, int dotdot_real_len);
3050 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
3051 				   unsigned int blocksize);
3052 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
3053 					 struct inode *inode,
3054 					 struct buffer_head *bh);
3055 #define S_SHIFT 12
3056 static const unsigned char ext4_type_by_mode[(S_IFMT >> S_SHIFT) + 1] = {
3057 	[S_IFREG >> S_SHIFT]	= EXT4_FT_REG_FILE,
3058 	[S_IFDIR >> S_SHIFT]	= EXT4_FT_DIR,
3059 	[S_IFCHR >> S_SHIFT]	= EXT4_FT_CHRDEV,
3060 	[S_IFBLK >> S_SHIFT]	= EXT4_FT_BLKDEV,
3061 	[S_IFIFO >> S_SHIFT]	= EXT4_FT_FIFO,
3062 	[S_IFSOCK >> S_SHIFT]	= EXT4_FT_SOCK,
3063 	[S_IFLNK >> S_SHIFT]	= EXT4_FT_SYMLINK,
3064 };
3065 
3066 static inline void ext4_set_de_type(struct super_block *sb,
3067 				struct ext4_dir_entry_2 *de,
3068 				umode_t mode) {
3069 	if (ext4_has_feature_filetype(sb))
3070 		de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
3071 }
3072 
3073 /* readpages.c */
3074 extern int ext4_mpage_readpages(struct address_space *mapping,
3075 				struct list_head *pages, struct page *page,
3076 				unsigned nr_pages, bool is_readahead);
3077 
3078 /* symlink.c */
3079 extern const struct inode_operations ext4_encrypted_symlink_inode_operations;
3080 extern const struct inode_operations ext4_symlink_inode_operations;
3081 extern const struct inode_operations ext4_fast_symlink_inode_operations;
3082 
3083 /* sysfs.c */
3084 extern int ext4_register_sysfs(struct super_block *sb);
3085 extern void ext4_unregister_sysfs(struct super_block *sb);
3086 extern int __init ext4_init_sysfs(void);
3087 extern void ext4_exit_sysfs(void);
3088 
3089 /* block_validity */
3090 extern void ext4_release_system_zone(struct super_block *sb);
3091 extern int ext4_setup_system_zone(struct super_block *sb);
3092 extern int __init ext4_init_system_zone(void);
3093 extern void ext4_exit_system_zone(void);
3094 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
3095 				 ext4_fsblk_t start_blk,
3096 				 unsigned int count);
3097 extern int ext4_check_blockref(const char *, unsigned int,
3098 			       struct inode *, __le32 *, unsigned int);
3099 
3100 /* extents.c */
3101 struct ext4_ext_path;
3102 struct ext4_extent;
3103 
3104 /*
3105  * Maximum number of logical blocks in a file; ext4_extent's ee_block is
3106  * __le32.
3107  */
3108 #define EXT_MAX_BLOCKS	0xffffffff
3109 
3110 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
3111 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
3112 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
3113 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
3114 			       struct ext4_map_blocks *map, int flags);
3115 extern int ext4_ext_truncate(handle_t *, struct inode *);
3116 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
3117 				 ext4_lblk_t end);
3118 extern void ext4_ext_init(struct super_block *);
3119 extern void ext4_ext_release(struct super_block *);
3120 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
3121 			  loff_t len);
3122 extern int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
3123 					  loff_t offset, ssize_t len);
3124 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
3125 			   struct ext4_map_blocks *map, int flags);
3126 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
3127 					 ext4_lblk_t lblocks);
3128 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
3129 						   int num,
3130 						   struct ext4_ext_path *path);
3131 extern int ext4_can_extents_be_merged(struct inode *inode,
3132 				      struct ext4_extent *ex1,
3133 				      struct ext4_extent *ex2);
3134 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
3135 				  struct ext4_ext_path **,
3136 				  struct ext4_extent *, int);
3137 extern struct ext4_ext_path *ext4_find_extent(struct inode *, ext4_lblk_t,
3138 					      struct ext4_ext_path **,
3139 					      int flags);
3140 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
3141 extern int ext4_ext_check_inode(struct inode *inode);
3142 extern ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path);
3143 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3144 			__u64 start, __u64 len);
3145 extern int ext4_ext_precache(struct inode *inode);
3146 extern int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len);
3147 extern int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len);
3148 extern int ext4_swap_extents(handle_t *handle, struct inode *inode1,
3149 				struct inode *inode2, ext4_lblk_t lblk1,
3150 			     ext4_lblk_t lblk2,  ext4_lblk_t count,
3151 			     int mark_unwritten,int *err);
3152 extern int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu);
3153 
3154 /* move_extent.c */
3155 extern void ext4_double_down_write_data_sem(struct inode *first,
3156 					    struct inode *second);
3157 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
3158 					  struct inode *donor_inode);
3159 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
3160 			     __u64 start_orig, __u64 start_donor,
3161 			     __u64 len, __u64 *moved_len);
3162 
3163 /* page-io.c */
3164 extern int __init ext4_init_pageio(void);
3165 extern void ext4_exit_pageio(void);
3166 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
3167 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
3168 extern int ext4_put_io_end(ext4_io_end_t *io_end);
3169 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
3170 extern void ext4_io_submit_init(struct ext4_io_submit *io,
3171 				struct writeback_control *wbc);
3172 extern void ext4_end_io_rsv_work(struct work_struct *work);
3173 extern void ext4_io_submit(struct ext4_io_submit *io);
3174 extern int ext4_bio_write_page(struct ext4_io_submit *io,
3175 			       struct page *page,
3176 			       int len,
3177 			       struct writeback_control *wbc,
3178 			       bool keep_towrite);
3179 
3180 /* mmp.c */
3181 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
3182 
3183 /*
3184  * Add new method to test whether block and inode bitmaps are properly
3185  * initialized. With uninit_bg reading the block from disk is not enough
3186  * to mark the bitmap uptodate. We need to also zero-out the bitmap
3187  */
3188 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
3189 
3190 static inline int bitmap_uptodate(struct buffer_head *bh)
3191 {
3192 	return (buffer_uptodate(bh) &&
3193 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
3194 }
3195 static inline void set_bitmap_uptodate(struct buffer_head *bh)
3196 {
3197 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
3198 }
3199 
3200 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
3201 
3202 /* For ioend & aio unwritten conversion wait queues */
3203 #define EXT4_WQ_HASH_SZ		37
3204 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
3205 					    EXT4_WQ_HASH_SZ])
3206 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
3207 
3208 extern int ext4_resize_begin(struct super_block *sb);
3209 extern void ext4_resize_end(struct super_block *sb);
3210 
3211 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
3212 					      struct ext4_io_end *io_end)
3213 {
3214 	if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
3215 		io_end->flag |= EXT4_IO_END_UNWRITTEN;
3216 		atomic_inc(&EXT4_I(inode)->i_unwritten);
3217 	}
3218 }
3219 
3220 static inline void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end)
3221 {
3222 	struct inode *inode = io_end->inode;
3223 
3224 	if (io_end->flag & EXT4_IO_END_UNWRITTEN) {
3225 		io_end->flag &= ~EXT4_IO_END_UNWRITTEN;
3226 		/* Wake up anyone waiting on unwritten extent conversion */
3227 		if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten))
3228 			wake_up_all(ext4_ioend_wq(inode));
3229 	}
3230 }
3231 
3232 extern const struct iomap_ops ext4_iomap_ops;
3233 
3234 #endif	/* __KERNEL__ */
3235 
3236 #define EFSBADCRC	EBADMSG		/* Bad CRC detected */
3237 #define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
3238 
3239 #endif	/* _EXT4_H */
3240