xref: /openbmc/linux/fs/ext4/ext4.h (revision 82e6fdd6)
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 /*
47  * The fourth extended filesystem constants/structures
48  */
49 
50 /*
51  * with AGGRESSIVE_CHECK allocator runs consistency checks over
52  * structures. these checks slow things down a lot
53  */
54 #define AGGRESSIVE_CHECK__
55 
56 /*
57  * with DOUBLE_CHECK defined mballoc creates persistent in-core
58  * bitmaps, maintains and uses them to check for double allocations
59  */
60 #define DOUBLE_CHECK__
61 
62 /*
63  * Define EXT4FS_DEBUG to produce debug messages
64  */
65 #undef EXT4FS_DEBUG
66 
67 /*
68  * Debug code
69  */
70 #ifdef EXT4FS_DEBUG
71 #define ext4_debug(f, a...)						\
72 	do {								\
73 		printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",	\
74 			__FILE__, __LINE__, __func__);			\
75 		printk(KERN_DEBUG f, ## a);				\
76 	} while (0)
77 #else
78 #define ext4_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
79 #endif
80 
81 /*
82  * Turn on EXT_DEBUG to get lots of info about extents operations.
83  */
84 #define EXT_DEBUG__
85 #ifdef EXT_DEBUG
86 #define ext_debug(fmt, ...)	printk(fmt, ##__VA_ARGS__)
87 #else
88 #define ext_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
89 #endif
90 
91 /* data type for block offset of block group */
92 typedef int ext4_grpblk_t;
93 
94 /* data type for filesystem-wide blocks number */
95 typedef unsigned long long ext4_fsblk_t;
96 
97 /* data type for file logical block number */
98 typedef __u32 ext4_lblk_t;
99 
100 /* data type for block group number */
101 typedef unsigned int ext4_group_t;
102 
103 enum SHIFT_DIRECTION {
104 	SHIFT_LEFT = 0,
105 	SHIFT_RIGHT,
106 };
107 
108 /*
109  * Flags used in mballoc's allocation_context flags field.
110  *
111  * Also used to show what's going on for debugging purposes when the
112  * flag field is exported via the traceport interface
113  */
114 
115 /* prefer goal again. length */
116 #define EXT4_MB_HINT_MERGE		0x0001
117 /* blocks already reserved */
118 #define EXT4_MB_HINT_RESERVED		0x0002
119 /* metadata is being allocated */
120 #define EXT4_MB_HINT_METADATA		0x0004
121 /* first blocks in the file */
122 #define EXT4_MB_HINT_FIRST		0x0008
123 /* search for the best chunk */
124 #define EXT4_MB_HINT_BEST		0x0010
125 /* data is being allocated */
126 #define EXT4_MB_HINT_DATA		0x0020
127 /* don't preallocate (for tails) */
128 #define EXT4_MB_HINT_NOPREALLOC		0x0040
129 /* allocate for locality group */
130 #define EXT4_MB_HINT_GROUP_ALLOC	0x0080
131 /* allocate goal blocks or none */
132 #define EXT4_MB_HINT_GOAL_ONLY		0x0100
133 /* goal is meaningful */
134 #define EXT4_MB_HINT_TRY_GOAL		0x0200
135 /* blocks already pre-reserved by delayed allocation */
136 #define EXT4_MB_DELALLOC_RESERVED	0x0400
137 /* We are doing stream allocation */
138 #define EXT4_MB_STREAM_ALLOC		0x0800
139 /* Use reserved root blocks if needed */
140 #define EXT4_MB_USE_ROOT_BLOCKS		0x1000
141 /* Use blocks from reserved pool */
142 #define EXT4_MB_USE_RESERVED		0x2000
143 
144 struct ext4_allocation_request {
145 	/* target inode for block we're allocating */
146 	struct inode *inode;
147 	/* how many blocks we want to allocate */
148 	unsigned int len;
149 	/* logical block in target inode */
150 	ext4_lblk_t logical;
151 	/* the closest logical allocated block to the left */
152 	ext4_lblk_t lleft;
153 	/* the closest logical allocated block to the right */
154 	ext4_lblk_t lright;
155 	/* phys. target (a hint) */
156 	ext4_fsblk_t goal;
157 	/* phys. block for the closest logical allocated block to the left */
158 	ext4_fsblk_t pleft;
159 	/* phys. block for the closest logical allocated block to the right */
160 	ext4_fsblk_t pright;
161 	/* flags. see above EXT4_MB_HINT_* */
162 	unsigned int flags;
163 };
164 
165 /*
166  * Logical to physical block mapping, used by ext4_map_blocks()
167  *
168  * This structure is used to pass requests into ext4_map_blocks() as
169  * well as to store the information returned by ext4_map_blocks().  It
170  * takes less room on the stack than a struct buffer_head.
171  */
172 #define EXT4_MAP_NEW		(1 << BH_New)
173 #define EXT4_MAP_MAPPED		(1 << BH_Mapped)
174 #define EXT4_MAP_UNWRITTEN	(1 << BH_Unwritten)
175 #define EXT4_MAP_BOUNDARY	(1 << BH_Boundary)
176 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
177 				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY)
178 
179 struct ext4_map_blocks {
180 	ext4_fsblk_t m_pblk;
181 	ext4_lblk_t m_lblk;
182 	unsigned int m_len;
183 	unsigned int m_flags;
184 };
185 
186 /*
187  * Flags for ext4_io_end->flags
188  */
189 #define	EXT4_IO_END_UNWRITTEN	0x0001
190 
191 /*
192  * For converting unwritten extents on a work queue. 'handle' is used for
193  * buffered writeback.
194  */
195 typedef struct ext4_io_end {
196 	struct list_head	list;		/* per-file finished IO list */
197 	handle_t		*handle;	/* handle reserved for extent
198 						 * conversion */
199 	struct inode		*inode;		/* file being written to */
200 	struct bio		*bio;		/* Linked list of completed
201 						 * bios covering the extent */
202 	unsigned int		flag;		/* unwritten or not */
203 	atomic_t		count;		/* reference counter */
204 	loff_t			offset;		/* offset in the file */
205 	ssize_t			size;		/* size of the extent */
206 } ext4_io_end_t;
207 
208 struct ext4_io_submit {
209 	struct writeback_control *io_wbc;
210 	struct bio		*io_bio;
211 	ext4_io_end_t		*io_end;
212 	sector_t		io_next_block;
213 };
214 
215 /*
216  * Special inodes numbers
217  */
218 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
219 #define EXT4_ROOT_INO		 2	/* Root inode */
220 #define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
221 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
222 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
223 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
224 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
225 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
226 
227 /* First non-reserved inode for old ext4 filesystems */
228 #define EXT4_GOOD_OLD_FIRST_INO	11
229 
230 /*
231  * Maximal count of links to a file
232  */
233 #define EXT4_LINK_MAX		65000
234 
235 /*
236  * Macro-instructions used to manage several block sizes
237  */
238 #define EXT4_MIN_BLOCK_SIZE		1024
239 #define	EXT4_MAX_BLOCK_SIZE		65536
240 #define EXT4_MIN_BLOCK_LOG_SIZE		10
241 #define EXT4_MAX_BLOCK_LOG_SIZE		16
242 #define EXT4_MAX_CLUSTER_LOG_SIZE	30
243 #ifdef __KERNEL__
244 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
245 #else
246 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
247 #endif
248 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
249 #define EXT4_CLUSTER_SIZE(s)		(EXT4_BLOCK_SIZE(s) << \
250 					 EXT4_SB(s)->s_cluster_bits)
251 #ifdef __KERNEL__
252 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
253 # define EXT4_CLUSTER_BITS(s)		(EXT4_SB(s)->s_cluster_bits)
254 #else
255 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
256 #endif
257 #ifdef __KERNEL__
258 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
259 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
260 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
261 #else
262 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
263 				 EXT4_GOOD_OLD_INODE_SIZE : \
264 				 (s)->s_inode_size)
265 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
266 				 EXT4_GOOD_OLD_FIRST_INO : \
267 				 (s)->s_first_ino)
268 #endif
269 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
270 #define EXT4_MAX_BLOCKS(size, offset, blkbits) \
271 	((EXT4_BLOCK_ALIGN(size + offset, blkbits) >> blkbits) - (offset >> \
272 								  blkbits))
273 
274 /* Translate a block number to a cluster number */
275 #define EXT4_B2C(sbi, blk)	((blk) >> (sbi)->s_cluster_bits)
276 /* Translate a cluster number to a block number */
277 #define EXT4_C2B(sbi, cluster)	((cluster) << (sbi)->s_cluster_bits)
278 /* Translate # of blks to # of clusters */
279 #define EXT4_NUM_B2C(sbi, blks)	(((blks) + (sbi)->s_cluster_ratio - 1) >> \
280 				 (sbi)->s_cluster_bits)
281 /* Mask out the low bits to get the starting block of the cluster */
282 #define EXT4_PBLK_CMASK(s, pblk) ((pblk) &				\
283 				  ~((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
284 #define EXT4_LBLK_CMASK(s, lblk) ((lblk) &				\
285 				  ~((ext4_lblk_t) (s)->s_cluster_ratio - 1))
286 /* Get the cluster offset */
287 #define EXT4_PBLK_COFF(s, pblk) ((pblk) &				\
288 				 ((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
289 #define EXT4_LBLK_COFF(s, lblk) ((lblk) &				\
290 				 ((ext4_lblk_t) (s)->s_cluster_ratio - 1))
291 
292 /*
293  * Structure of a blocks group descriptor
294  */
295 struct ext4_group_desc
296 {
297 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
298 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
299 	__le32	bg_inode_table_lo;	/* Inodes table block */
300 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
301 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
302 	__le16	bg_used_dirs_count_lo;	/* Directories count */
303 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
304 	__le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
305 	__le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
306 	__le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
307 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
308 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
309 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
310 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
311 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
312 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
313 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
314 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
315 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
316 	__le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
317 	__le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
318 	__le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
319 	__u32   bg_reserved;
320 };
321 
322 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END	\
323 	(offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
324 	 sizeof(__le16))
325 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END	\
326 	(offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
327 	 sizeof(__le16))
328 
329 /*
330  * Structure of a flex block group info
331  */
332 
333 struct flex_groups {
334 	atomic64_t	free_clusters;
335 	atomic_t	free_inodes;
336 	atomic_t	used_dirs;
337 };
338 
339 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
340 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
341 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
342 
343 /*
344  * Macro-instructions used to manage group descriptors
345  */
346 #define EXT4_MIN_DESC_SIZE		32
347 #define EXT4_MIN_DESC_SIZE_64BIT	64
348 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
349 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
350 #ifdef __KERNEL__
351 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
352 # define EXT4_CLUSTERS_PER_GROUP(s)	(EXT4_SB(s)->s_clusters_per_group)
353 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
354 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
355 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
356 #else
357 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
358 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
359 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
360 #endif
361 
362 /*
363  * Constants relative to the data blocks
364  */
365 #define	EXT4_NDIR_BLOCKS		12
366 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
367 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
368 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
369 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
370 
371 /*
372  * Inode flags
373  */
374 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
375 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
376 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
377 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
378 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
379 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
380 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
381 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
382 /* Reserved for compression usage... */
383 #define EXT4_DIRTY_FL			0x00000100
384 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
385 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
386 	/* nb: was previously EXT2_ECOMPR_FL */
387 #define EXT4_ENCRYPT_FL			0x00000800 /* encrypted file */
388 /* End compression flags --- maybe not all used */
389 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
390 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
391 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
392 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
393 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
394 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
395 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
396 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
397 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
398 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
399 #define EXT4_INLINE_DATA_FL		0x10000000 /* Inode has inline data. */
400 #define EXT4_PROJINHERIT_FL		0x20000000 /* Create with parents projid */
401 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
402 
403 #define EXT4_FL_USER_VISIBLE		0x304BDFFF /* User visible flags */
404 #define EXT4_FL_USER_MODIFIABLE		0x204BC0FF /* User modifiable flags */
405 
406 /* Flags we can manipulate with through EXT4_IOC_FSSETXATTR */
407 #define EXT4_FL_XFLAG_VISIBLE		(EXT4_SYNC_FL | \
408 					 EXT4_IMMUTABLE_FL | \
409 					 EXT4_APPEND_FL | \
410 					 EXT4_NODUMP_FL | \
411 					 EXT4_NOATIME_FL | \
412 					 EXT4_PROJINHERIT_FL)
413 
414 /* Flags that should be inherited by new inodes from their parent. */
415 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
416 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
417 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
418 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL |\
419 			   EXT4_PROJINHERIT_FL)
420 
421 /* Flags that are appropriate for regular files (all but dir-specific ones). */
422 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
423 
424 /* Flags that are appropriate for non-directories/regular files. */
425 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
426 
427 /* Mask out flags that are inappropriate for the given type of inode. */
428 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
429 {
430 	if (S_ISDIR(mode))
431 		return flags;
432 	else if (S_ISREG(mode))
433 		return flags & EXT4_REG_FLMASK;
434 	else
435 		return flags & EXT4_OTHER_FLMASK;
436 }
437 
438 /*
439  * Inode flags used for atomic set/get
440  */
441 enum {
442 	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
443 	EXT4_INODE_UNRM		= 1,	/* Undelete */
444 	EXT4_INODE_COMPR	= 2,	/* Compress file */
445 	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
446 	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
447 	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
448 	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
449 	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
450 /* Reserved for compression usage... */
451 	EXT4_INODE_DIRTY	= 8,
452 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
453 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
454 	EXT4_INODE_ENCRYPT	= 11,	/* Encrypted file */
455 /* End compression flags --- maybe not all used */
456 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
457 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
458 	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
459 	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
460 	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
461 	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
462 	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
463 	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
464 	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
465 	EXT4_INODE_EOFBLOCKS	= 22,	/* Blocks allocated beyond EOF */
466 	EXT4_INODE_INLINE_DATA	= 28,	/* Data in inode. */
467 	EXT4_INODE_PROJINHERIT	= 29,	/* Create with parents projid */
468 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
469 };
470 
471 /*
472  * Since it's pretty easy to mix up bit numbers and hex values, we use a
473  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
474  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
475  * any extra space in the compiled kernel image, otherwise, the build will fail.
476  * It's important that these values are the same, since we are using
477  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
478  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
479  * values found in ext2, ext3 and ext4 filesystems, and of course the values
480  * defined in e2fsprogs.
481  *
482  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
483  */
484 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
485 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
486 
487 static inline void ext4_check_flag_values(void)
488 {
489 	CHECK_FLAG_VALUE(SECRM);
490 	CHECK_FLAG_VALUE(UNRM);
491 	CHECK_FLAG_VALUE(COMPR);
492 	CHECK_FLAG_VALUE(SYNC);
493 	CHECK_FLAG_VALUE(IMMUTABLE);
494 	CHECK_FLAG_VALUE(APPEND);
495 	CHECK_FLAG_VALUE(NODUMP);
496 	CHECK_FLAG_VALUE(NOATIME);
497 	CHECK_FLAG_VALUE(DIRTY);
498 	CHECK_FLAG_VALUE(COMPRBLK);
499 	CHECK_FLAG_VALUE(NOCOMPR);
500 	CHECK_FLAG_VALUE(ENCRYPT);
501 	CHECK_FLAG_VALUE(INDEX);
502 	CHECK_FLAG_VALUE(IMAGIC);
503 	CHECK_FLAG_VALUE(JOURNAL_DATA);
504 	CHECK_FLAG_VALUE(NOTAIL);
505 	CHECK_FLAG_VALUE(DIRSYNC);
506 	CHECK_FLAG_VALUE(TOPDIR);
507 	CHECK_FLAG_VALUE(HUGE_FILE);
508 	CHECK_FLAG_VALUE(EXTENTS);
509 	CHECK_FLAG_VALUE(EA_INODE);
510 	CHECK_FLAG_VALUE(EOFBLOCKS);
511 	CHECK_FLAG_VALUE(INLINE_DATA);
512 	CHECK_FLAG_VALUE(PROJINHERIT);
513 	CHECK_FLAG_VALUE(RESERVED);
514 }
515 
516 /* Used to pass group descriptor data when online resize is done */
517 struct ext4_new_group_input {
518 	__u32 group;		/* Group number for this data */
519 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
520 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
521 	__u64 inode_table;	/* Absolute block number of inode table start */
522 	__u32 blocks_count;	/* Total number of blocks in this group */
523 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
524 	__u16 unused;
525 };
526 
527 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
528 struct compat_ext4_new_group_input {
529 	u32 group;
530 	compat_u64 block_bitmap;
531 	compat_u64 inode_bitmap;
532 	compat_u64 inode_table;
533 	u32 blocks_count;
534 	u16 reserved_blocks;
535 	u16 unused;
536 };
537 #endif
538 
539 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
540 struct ext4_new_group_data {
541 	__u32 group;
542 	__u64 block_bitmap;
543 	__u64 inode_bitmap;
544 	__u64 inode_table;
545 	__u32 blocks_count;
546 	__u16 reserved_blocks;
547 	__u16 mdata_blocks;
548 	__u32 free_clusters_count;
549 };
550 
551 /* Indexes used to index group tables in ext4_new_group_data */
552 enum {
553 	BLOCK_BITMAP = 0,	/* block bitmap */
554 	INODE_BITMAP,		/* inode bitmap */
555 	INODE_TABLE,		/* inode tables */
556 	GROUP_TABLE_COUNT,
557 };
558 
559 /*
560  * Flags used by ext4_map_blocks()
561  */
562 	/* Allocate any needed blocks and/or convert an unwritten
563 	   extent to be an initialized ext4 */
564 #define EXT4_GET_BLOCKS_CREATE			0x0001
565 	/* Request the creation of an unwritten extent */
566 #define EXT4_GET_BLOCKS_UNWRIT_EXT		0x0002
567 #define EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT	(EXT4_GET_BLOCKS_UNWRIT_EXT|\
568 						 EXT4_GET_BLOCKS_CREATE)
569 	/* Caller is from the delayed allocation writeout path
570 	 * finally doing the actual allocation of delayed blocks */
571 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
572 	/* caller is from the direct IO path, request to creation of an
573 	unwritten extents if not allocated, split the unwritten
574 	extent if blocks has been preallocated already*/
575 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
576 #define EXT4_GET_BLOCKS_CONVERT			0x0010
577 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
578 					 EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
579 	/* Convert extent to initialized after IO complete */
580 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
581 					 EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
582 	/* Eventual metadata allocation (due to growing extent tree)
583 	 * should not fail, so try to use reserved blocks for that.*/
584 #define EXT4_GET_BLOCKS_METADATA_NOFAIL		0x0020
585 	/* Don't normalize allocation size (used for fallocate) */
586 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
587 	/* Request will not result in inode size update (user for fallocate) */
588 #define EXT4_GET_BLOCKS_KEEP_SIZE		0x0080
589 	/* Convert written extents to unwritten */
590 #define EXT4_GET_BLOCKS_CONVERT_UNWRITTEN	0x0100
591 	/* Write zeros to newly created written extents */
592 #define EXT4_GET_BLOCKS_ZERO			0x0200
593 #define EXT4_GET_BLOCKS_CREATE_ZERO		(EXT4_GET_BLOCKS_CREATE |\
594 					EXT4_GET_BLOCKS_ZERO)
595 	/* Caller will submit data before dropping transaction handle. This
596 	 * allows jbd2 to avoid submitting data before commit. */
597 #define EXT4_GET_BLOCKS_IO_SUBMIT		0x0400
598 
599 /*
600  * The bit position of these flags must not overlap with any of the
601  * EXT4_GET_BLOCKS_*.  They are used by ext4_find_extent(),
602  * read_extent_tree_block(), ext4_split_extent_at(),
603  * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf().
604  * EXT4_EX_NOCACHE is used to indicate that the we shouldn't be
605  * caching the extents when reading from the extent tree while a
606  * truncate or punch hole operation is in progress.
607  */
608 #define EXT4_EX_NOCACHE				0x40000000
609 #define EXT4_EX_FORCE_CACHE			0x20000000
610 
611 /*
612  * Flags used by ext4_free_blocks
613  */
614 #define EXT4_FREE_BLOCKS_METADATA		0x0001
615 #define EXT4_FREE_BLOCKS_FORGET			0x0002
616 #define EXT4_FREE_BLOCKS_VALIDATED		0x0004
617 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE		0x0008
618 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
619 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
620 
621 /*
622  * ioctl commands
623  */
624 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
625 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
626 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
627 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
628 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
629 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
630 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
631 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
632 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
633 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
634 #define EXT4_IOC_MIGRATE		_IO('f', 9)
635  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
636  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
637 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
638 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
639 #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
640 #define EXT4_IOC_SWAP_BOOT		_IO('f', 17)
641 #define EXT4_IOC_PRECACHE_EXTENTS	_IO('f', 18)
642 #define EXT4_IOC_SET_ENCRYPTION_POLICY	FS_IOC_SET_ENCRYPTION_POLICY
643 #define EXT4_IOC_GET_ENCRYPTION_PWSALT	FS_IOC_GET_ENCRYPTION_PWSALT
644 #define EXT4_IOC_GET_ENCRYPTION_POLICY	FS_IOC_GET_ENCRYPTION_POLICY
645 
646 #define EXT4_IOC_FSGETXATTR		FS_IOC_FSGETXATTR
647 #define EXT4_IOC_FSSETXATTR		FS_IOC_FSSETXATTR
648 
649 #define EXT4_IOC_SHUTDOWN _IOR ('X', 125, __u32)
650 
651 /*
652  * Flags for going down operation
653  */
654 #define EXT4_GOING_FLAGS_DEFAULT		0x0	/* going down */
655 #define EXT4_GOING_FLAGS_LOGFLUSH		0x1	/* flush log but not data */
656 #define EXT4_GOING_FLAGS_NOLOGFLUSH		0x2	/* don't flush log nor data */
657 
658 
659 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
660 /*
661  * ioctl commands in 32 bit emulation
662  */
663 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
664 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
665 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
666 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
667 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
668 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
669 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
670 #define EXT4_IOC32_GROUP_ADD		_IOW('f', 8, struct compat_ext4_new_group_input)
671 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
672 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
673 #endif
674 
675 /* Max physical block we can address w/o extents */
676 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
677 
678 /*
679  * Structure of an inode on the disk
680  */
681 struct ext4_inode {
682 	__le16	i_mode;		/* File mode */
683 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
684 	__le32	i_size_lo;	/* Size in bytes */
685 	__le32	i_atime;	/* Access time */
686 	__le32	i_ctime;	/* Inode Change time */
687 	__le32	i_mtime;	/* Modification time */
688 	__le32	i_dtime;	/* Deletion Time */
689 	__le16	i_gid;		/* Low 16 bits of Group Id */
690 	__le16	i_links_count;	/* Links count */
691 	__le32	i_blocks_lo;	/* Blocks count */
692 	__le32	i_flags;	/* File flags */
693 	union {
694 		struct {
695 			__le32  l_i_version;
696 		} linux1;
697 		struct {
698 			__u32  h_i_translator;
699 		} hurd1;
700 		struct {
701 			__u32  m_i_reserved1;
702 		} masix1;
703 	} osd1;				/* OS dependent 1 */
704 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
705 	__le32	i_generation;	/* File version (for NFS) */
706 	__le32	i_file_acl_lo;	/* File ACL */
707 	__le32	i_size_high;
708 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
709 	union {
710 		struct {
711 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
712 			__le16	l_i_file_acl_high;
713 			__le16	l_i_uid_high;	/* these 2 fields */
714 			__le16	l_i_gid_high;	/* were reserved2[0] */
715 			__le16	l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
716 			__le16	l_i_reserved;
717 		} linux2;
718 		struct {
719 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
720 			__u16	h_i_mode_high;
721 			__u16	h_i_uid_high;
722 			__u16	h_i_gid_high;
723 			__u32	h_i_author;
724 		} hurd2;
725 		struct {
726 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
727 			__le16	m_i_file_acl_high;
728 			__u32	m_i_reserved2[2];
729 		} masix2;
730 	} osd2;				/* OS dependent 2 */
731 	__le16	i_extra_isize;
732 	__le16	i_checksum_hi;	/* crc32c(uuid+inum+inode) BE */
733 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
734 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
735 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
736 	__le32  i_crtime;       /* File Creation time */
737 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
738 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
739 	__le32	i_projid;	/* Project ID */
740 };
741 
742 struct move_extent {
743 	__u32 reserved;		/* should be zero */
744 	__u32 donor_fd;		/* donor file descriptor */
745 	__u64 orig_start;	/* logical start offset in block for orig */
746 	__u64 donor_start;	/* logical start offset in block for donor */
747 	__u64 len;		/* block length to be moved */
748 	__u64 moved_len;	/* moved block length */
749 };
750 
751 #define EXT4_EPOCH_BITS 2
752 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
753 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
754 
755 /*
756  * Extended fields will fit into an inode if the filesystem was formatted
757  * with large inodes (-I 256 or larger) and there are not currently any EAs
758  * consuming all of the available space. For new inodes we always reserve
759  * enough space for the kernel's known extended fields, but for inodes
760  * created with an old kernel this might not have been the case. None of
761  * the extended inode fields is critical for correct filesystem operation.
762  * This macro checks if a certain field fits in the inode. Note that
763  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
764  */
765 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
766 	((offsetof(typeof(*ext4_inode), field) +	\
767 	  sizeof((ext4_inode)->field))			\
768 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
769 	    (einode)->i_extra_isize))			\
770 
771 /*
772  * We use an encoding that preserves the times for extra epoch "00":
773  *
774  * extra  msb of                         adjust for signed
775  * epoch  32-bit                         32-bit tv_sec to
776  * bits   time    decoded 64-bit tv_sec  64-bit tv_sec      valid time range
777  * 0 0    1    -0x80000000..-0x00000001  0x000000000 1901-12-13..1969-12-31
778  * 0 0    0    0x000000000..0x07fffffff  0x000000000 1970-01-01..2038-01-19
779  * 0 1    1    0x080000000..0x0ffffffff  0x100000000 2038-01-19..2106-02-07
780  * 0 1    0    0x100000000..0x17fffffff  0x100000000 2106-02-07..2174-02-25
781  * 1 0    1    0x180000000..0x1ffffffff  0x200000000 2174-02-25..2242-03-16
782  * 1 0    0    0x200000000..0x27fffffff  0x200000000 2242-03-16..2310-04-04
783  * 1 1    1    0x280000000..0x2ffffffff  0x300000000 2310-04-04..2378-04-22
784  * 1 1    0    0x300000000..0x37fffffff  0x300000000 2378-04-22..2446-05-10
785  *
786  * Note that previous versions of the kernel on 64-bit systems would
787  * incorrectly use extra epoch bits 1,1 for dates between 1901 and
788  * 1970.  e2fsck will correct this, assuming that it is run on the
789  * affected filesystem before 2242.
790  */
791 
792 static inline __le32 ext4_encode_extra_time(struct timespec *time)
793 {
794 	u32 extra = sizeof(time->tv_sec) > 4 ?
795 		((time->tv_sec - (s32)time->tv_sec) >> 32) & EXT4_EPOCH_MASK : 0;
796 	return cpu_to_le32(extra | (time->tv_nsec << EXT4_EPOCH_BITS));
797 }
798 
799 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
800 {
801 	if (unlikely(sizeof(time->tv_sec) > 4 &&
802 			(extra & cpu_to_le32(EXT4_EPOCH_MASK)))) {
803 
804 #if 1
805 		/* Handle legacy encoding of pre-1970 dates with epoch
806 		 * bits 1,1. (This backwards compatibility may be removed
807 		 * at the discretion of the ext4 developers.)
808 		 */
809 		u64 extra_bits = le32_to_cpu(extra) & EXT4_EPOCH_MASK;
810 		if (extra_bits == 3 && ((time->tv_sec) & 0x80000000) != 0)
811 			extra_bits = 0;
812 		time->tv_sec += extra_bits << 32;
813 #else
814 		time->tv_sec += (u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK) << 32;
815 #endif
816 	}
817 	time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
818 }
819 
820 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
821 do {									       \
822 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
823 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
824 		(raw_inode)->xtime ## _extra =				       \
825 				ext4_encode_extra_time(&(inode)->xtime);       \
826 } while (0)
827 
828 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
829 do {									       \
830 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
831 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
832 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
833 		(raw_inode)->xtime ## _extra =				       \
834 				ext4_encode_extra_time(&(einode)->xtime);      \
835 } while (0)
836 
837 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
838 do {									       \
839 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
840 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
841 		ext4_decode_extra_time(&(inode)->xtime,			       \
842 				       raw_inode->xtime ## _extra);	       \
843 	else								       \
844 		(inode)->xtime.tv_nsec = 0;				       \
845 } while (0)
846 
847 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
848 do {									       \
849 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
850 		(einode)->xtime.tv_sec = 				       \
851 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
852 	else								       \
853 		(einode)->xtime.tv_sec = 0;				       \
854 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
855 		ext4_decode_extra_time(&(einode)->xtime,		       \
856 				       raw_inode->xtime ## _extra);	       \
857 	else								       \
858 		(einode)->xtime.tv_nsec = 0;				       \
859 } while (0)
860 
861 #define i_disk_version osd1.linux1.l_i_version
862 
863 #if defined(__KERNEL__) || defined(__linux__)
864 #define i_reserved1	osd1.linux1.l_i_reserved1
865 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
866 #define i_blocks_high	osd2.linux2.l_i_blocks_high
867 #define i_uid_low	i_uid
868 #define i_gid_low	i_gid
869 #define i_uid_high	osd2.linux2.l_i_uid_high
870 #define i_gid_high	osd2.linux2.l_i_gid_high
871 #define i_checksum_lo	osd2.linux2.l_i_checksum_lo
872 
873 #elif defined(__GNU__)
874 
875 #define i_translator	osd1.hurd1.h_i_translator
876 #define i_uid_high	osd2.hurd2.h_i_uid_high
877 #define i_gid_high	osd2.hurd2.h_i_gid_high
878 #define i_author	osd2.hurd2.h_i_author
879 
880 #elif defined(__masix__)
881 
882 #define i_reserved1	osd1.masix1.m_i_reserved1
883 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
884 #define i_reserved2	osd2.masix2.m_i_reserved2
885 
886 #endif /* defined(__KERNEL__) || defined(__linux__) */
887 
888 #include "extents_status.h"
889 
890 /*
891  * Lock subclasses for i_data_sem in the ext4_inode_info structure.
892  *
893  * These are needed to avoid lockdep false positives when we need to
894  * allocate blocks to the quota inode during ext4_map_blocks(), while
895  * holding i_data_sem for a normal (non-quota) inode.  Since we don't
896  * do quota tracking for the quota inode, this avoids deadlock (as
897  * well as infinite recursion, since it isn't turtles all the way
898  * down...)
899  *
900  *  I_DATA_SEM_NORMAL - Used for most inodes
901  *  I_DATA_SEM_OTHER  - Used by move_inode.c for the second normal inode
902  *			  where the second inode has larger inode number
903  *			  than the first
904  *  I_DATA_SEM_QUOTA  - Used for quota inodes only
905  */
906 enum {
907 	I_DATA_SEM_NORMAL = 0,
908 	I_DATA_SEM_OTHER,
909 	I_DATA_SEM_QUOTA,
910 };
911 
912 
913 /*
914  * fourth extended file system inode data in memory
915  */
916 struct ext4_inode_info {
917 	__le32	i_data[15];	/* unconverted */
918 	__u32	i_dtime;
919 	ext4_fsblk_t	i_file_acl;
920 
921 	/*
922 	 * i_block_group is the number of the block group which contains
923 	 * this file's inode.  Constant across the lifetime of the inode,
924 	 * it is used for making block allocation decisions - we try to
925 	 * place a file's data blocks near its inode block, and new inodes
926 	 * near to their parent directory's inode.
927 	 */
928 	ext4_group_t	i_block_group;
929 	ext4_lblk_t	i_dir_start_lookup;
930 #if (BITS_PER_LONG < 64)
931 	unsigned long	i_state_flags;		/* Dynamic state flags */
932 #endif
933 	unsigned long	i_flags;
934 
935 	/*
936 	 * Extended attributes can be read independently of the main file
937 	 * data. Taking i_mutex even when reading would cause contention
938 	 * between readers of EAs and writers of regular file data, so
939 	 * instead we synchronize on xattr_sem when reading or changing
940 	 * EAs.
941 	 */
942 	struct rw_semaphore xattr_sem;
943 
944 	struct list_head i_orphan;	/* unlinked but open inodes */
945 
946 	/*
947 	 * i_disksize keeps track of what the inode size is ON DISK, not
948 	 * in memory.  During truncate, i_size is set to the new size by
949 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
950 	 * set i_disksize to 0 until the truncate is actually under way.
951 	 *
952 	 * The intent is that i_disksize always represents the blocks which
953 	 * are used by this file.  This allows recovery to restart truncate
954 	 * on orphans if we crash during truncate.  We actually write i_disksize
955 	 * into the on-disk inode when writing inodes out, instead of i_size.
956 	 *
957 	 * The only time when i_disksize and i_size may be different is when
958 	 * a truncate is in progress.  The only things which change i_disksize
959 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
960 	 */
961 	loff_t	i_disksize;
962 
963 	/*
964 	 * i_data_sem is for serialising ext4_truncate() against
965 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
966 	 * data tree are chopped off during truncate. We can't do that in
967 	 * ext4 because whenever we perform intermediate commits during
968 	 * truncate, the inode and all the metadata blocks *must* be in a
969 	 * consistent state which allows truncation of the orphans to restart
970 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
971 	 * by other means, so we have i_data_sem.
972 	 */
973 	struct rw_semaphore i_data_sem;
974 	/*
975 	 * i_mmap_sem is for serializing page faults with truncate / punch hole
976 	 * operations. We have to make sure that new page cannot be faulted in
977 	 * a section of the inode that is being punched. We cannot easily use
978 	 * i_data_sem for this since we need protection for the whole punch
979 	 * operation and i_data_sem ranks below transaction start so we have
980 	 * to occasionally drop it.
981 	 */
982 	struct rw_semaphore i_mmap_sem;
983 	struct inode vfs_inode;
984 	struct jbd2_inode *jinode;
985 
986 	spinlock_t i_raw_lock;	/* protects updates to the raw inode */
987 
988 	/*
989 	 * File creation time. Its function is same as that of
990 	 * struct timespec i_{a,c,m}time in the generic inode.
991 	 */
992 	struct timespec i_crtime;
993 
994 	/* mballoc */
995 	struct list_head i_prealloc_list;
996 	spinlock_t i_prealloc_lock;
997 
998 	/* extents status tree */
999 	struct ext4_es_tree i_es_tree;
1000 	rwlock_t i_es_lock;
1001 	struct list_head i_es_list;
1002 	unsigned int i_es_all_nr;	/* protected by i_es_lock */
1003 	unsigned int i_es_shk_nr;	/* protected by i_es_lock */
1004 	ext4_lblk_t i_es_shrink_lblk;	/* Offset where we start searching for
1005 					   extents to shrink. Protected by
1006 					   i_es_lock  */
1007 
1008 	/* ialloc */
1009 	ext4_group_t	i_last_alloc_group;
1010 
1011 	/* allocation reservation info for delalloc */
1012 	/* In case of bigalloc, this refer to clusters rather than blocks */
1013 	unsigned int i_reserved_data_blocks;
1014 	ext4_lblk_t i_da_metadata_calc_last_lblock;
1015 	int i_da_metadata_calc_len;
1016 
1017 	/* on-disk additional length */
1018 	__u16 i_extra_isize;
1019 
1020 	/* Indicate the inline data space. */
1021 	u16 i_inline_off;
1022 	u16 i_inline_size;
1023 
1024 #ifdef CONFIG_QUOTA
1025 	/* quota space reservation, managed internally by quota code */
1026 	qsize_t i_reserved_quota;
1027 #endif
1028 
1029 	/* Lock protecting lists below */
1030 	spinlock_t i_completed_io_lock;
1031 	/*
1032 	 * Completed IOs that need unwritten extents handling and have
1033 	 * transaction reserved
1034 	 */
1035 	struct list_head i_rsv_conversion_list;
1036 	struct work_struct i_rsv_conversion_work;
1037 	atomic_t i_unwritten; /* Nr. of inflight conversions pending */
1038 
1039 	spinlock_t i_block_reservation_lock;
1040 
1041 	/*
1042 	 * Transactions that contain inode's metadata needed to complete
1043 	 * fsync and fdatasync, respectively.
1044 	 */
1045 	tid_t i_sync_tid;
1046 	tid_t i_datasync_tid;
1047 
1048 #ifdef CONFIG_QUOTA
1049 	struct dquot *i_dquot[MAXQUOTAS];
1050 #endif
1051 
1052 	/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
1053 	__u32 i_csum_seed;
1054 
1055 	kprojid_t i_projid;
1056 };
1057 
1058 /*
1059  * File system states
1060  */
1061 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
1062 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
1063 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
1064 
1065 /*
1066  * Misc. filesystem flags
1067  */
1068 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
1069 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
1070 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
1071 
1072 /*
1073  * Mount flags set via mount options or defaults
1074  */
1075 #define EXT4_MOUNT_NO_MBCACHE		0x00001 /* Do not use mbcache */
1076 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
1077 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
1078 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
1079 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
1080 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
1081 #define EXT4_MOUNT_ERRORS_MASK		0x00070
1082 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
1083 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
1084 #ifdef CONFIG_FS_DAX
1085 #define EXT4_MOUNT_DAX			0x00200	/* Direct Access */
1086 #else
1087 #define EXT4_MOUNT_DAX			0
1088 #endif
1089 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
1090 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
1091 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
1092 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
1093 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
1094 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
1095 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
1096 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
1097 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
1098 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
1099 #define EXT4_MOUNT_QUOTA		0x40000 /* Some quota option set */
1100 #define EXT4_MOUNT_USRQUOTA		0x80000 /* "old" user quota,
1101 						 * enable enforcement for hidden
1102 						 * quota files */
1103 #define EXT4_MOUNT_GRPQUOTA		0x100000 /* "old" group quota, enable
1104 						  * enforcement for hidden quota
1105 						  * files */
1106 #define EXT4_MOUNT_PRJQUOTA		0x200000 /* Enable project quota
1107 						  * enforcement */
1108 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
1109 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
1110 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
1111 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
1112 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
1113 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
1114 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
1115 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
1116 
1117 /*
1118  * Mount flags set either automatically (could not be set by mount option)
1119  * based on per file system feature or property or in special cases such as
1120  * distinguishing between explicit mount option definition and default.
1121  */
1122 #define EXT4_MOUNT2_EXPLICIT_DELALLOC	0x00000001 /* User explicitly
1123 						      specified delalloc */
1124 #define EXT4_MOUNT2_STD_GROUP_SIZE	0x00000002 /* We have standard group
1125 						      size of blocksize * 8
1126 						      blocks */
1127 #define EXT4_MOUNT2_HURD_COMPAT		0x00000004 /* Support HURD-castrated
1128 						      file systems */
1129 
1130 #define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM	0x00000008 /* User explicitly
1131 						specified journal checksum */
1132 
1133 #define clear_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt &= \
1134 						~EXT4_MOUNT_##opt
1135 #define set_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt |= \
1136 						EXT4_MOUNT_##opt
1137 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
1138 					 EXT4_MOUNT_##opt)
1139 
1140 #define clear_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 &= \
1141 						~EXT4_MOUNT2_##opt
1142 #define set_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 |= \
1143 						EXT4_MOUNT2_##opt
1144 #define test_opt2(sb, opt)		(EXT4_SB(sb)->s_mount_opt2 & \
1145 					 EXT4_MOUNT2_##opt)
1146 
1147 #define ext4_test_and_set_bit		__test_and_set_bit_le
1148 #define ext4_set_bit			__set_bit_le
1149 #define ext4_set_bit_atomic		ext2_set_bit_atomic
1150 #define ext4_test_and_clear_bit		__test_and_clear_bit_le
1151 #define ext4_clear_bit			__clear_bit_le
1152 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
1153 #define ext4_test_bit			test_bit_le
1154 #define ext4_find_next_zero_bit		find_next_zero_bit_le
1155 #define ext4_find_next_bit		find_next_bit_le
1156 
1157 extern void ext4_set_bits(void *bm, int cur, int len);
1158 
1159 /*
1160  * Maximal mount counts between two filesystem checks
1161  */
1162 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
1163 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
1164 
1165 /*
1166  * Behaviour when detecting errors
1167  */
1168 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
1169 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
1170 #define EXT4_ERRORS_PANIC		3	/* Panic */
1171 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
1172 
1173 /* Metadata checksum algorithm codes */
1174 #define EXT4_CRC32C_CHKSUM		1
1175 
1176 /*
1177  * Structure of the super block
1178  */
1179 struct ext4_super_block {
1180 /*00*/	__le32	s_inodes_count;		/* Inodes count */
1181 	__le32	s_blocks_count_lo;	/* Blocks count */
1182 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
1183 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
1184 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
1185 	__le32	s_first_data_block;	/* First Data Block */
1186 	__le32	s_log_block_size;	/* Block size */
1187 	__le32	s_log_cluster_size;	/* Allocation cluster size */
1188 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
1189 	__le32	s_clusters_per_group;	/* # Clusters per group */
1190 	__le32	s_inodes_per_group;	/* # Inodes per group */
1191 	__le32	s_mtime;		/* Mount time */
1192 /*30*/	__le32	s_wtime;		/* Write time */
1193 	__le16	s_mnt_count;		/* Mount count */
1194 	__le16	s_max_mnt_count;	/* Maximal mount count */
1195 	__le16	s_magic;		/* Magic signature */
1196 	__le16	s_state;		/* File system state */
1197 	__le16	s_errors;		/* Behaviour when detecting errors */
1198 	__le16	s_minor_rev_level;	/* minor revision level */
1199 /*40*/	__le32	s_lastcheck;		/* time of last check */
1200 	__le32	s_checkinterval;	/* max. time between checks */
1201 	__le32	s_creator_os;		/* OS */
1202 	__le32	s_rev_level;		/* Revision level */
1203 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
1204 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
1205 	/*
1206 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
1207 	 *
1208 	 * Note: the difference between the compatible feature set and
1209 	 * the incompatible feature set is that if there is a bit set
1210 	 * in the incompatible feature set that the kernel doesn't
1211 	 * know about, it should refuse to mount the filesystem.
1212 	 *
1213 	 * e2fsck's requirements are more strict; if it doesn't know
1214 	 * about a feature in either the compatible or incompatible
1215 	 * feature set, it must abort and not try to meddle with
1216 	 * things it doesn't understand...
1217 	 */
1218 	__le32	s_first_ino;		/* First non-reserved inode */
1219 	__le16  s_inode_size;		/* size of inode structure */
1220 	__le16	s_block_group_nr;	/* block group # of this superblock */
1221 	__le32	s_feature_compat;	/* compatible feature set */
1222 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
1223 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
1224 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
1225 /*78*/	char	s_volume_name[16];	/* volume name */
1226 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
1227 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
1228 	/*
1229 	 * Performance hints.  Directory preallocation should only
1230 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1231 	 */
1232 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
1233 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
1234 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
1235 	/*
1236 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1237 	 */
1238 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
1239 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
1240 	__le32	s_journal_dev;		/* device number of journal file */
1241 	__le32	s_last_orphan;		/* start of list of inodes to delete */
1242 	__le32	s_hash_seed[4];		/* HTREE hash seed */
1243 	__u8	s_def_hash_version;	/* Default hash version to use */
1244 	__u8	s_jnl_backup_type;
1245 	__le16  s_desc_size;		/* size of group descriptor */
1246 /*100*/	__le32	s_default_mount_opts;
1247 	__le32	s_first_meta_bg;	/* First metablock block group */
1248 	__le32	s_mkfs_time;		/* When the filesystem was created */
1249 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
1250 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1251 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
1252 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
1253 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
1254 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
1255 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
1256 	__le32	s_flags;		/* Miscellaneous flags */
1257 	__le16  s_raid_stride;		/* RAID stride */
1258 	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1259 	__le64  s_mmp_block;            /* Block for multi-mount protection */
1260 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1261 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
1262 	__u8	s_checksum_type;	/* metadata checksum algorithm used */
1263 	__u8	s_encryption_level;	/* versioning level for encryption */
1264 	__u8	s_reserved_pad;		/* Padding to next 32bits */
1265 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1266 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
1267 	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
1268 	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
1269 					      snapshot's future use */
1270 	__le32	s_snapshot_list;	/* inode number of the head of the
1271 					   on-disk snapshot list */
1272 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1273 	__le32	s_error_count;		/* number of fs errors */
1274 	__le32	s_first_error_time;	/* first time an error happened */
1275 	__le32	s_first_error_ino;	/* inode involved in first error */
1276 	__le64	s_first_error_block;	/* block involved of first error */
1277 	__u8	s_first_error_func[32];	/* function where the error happened */
1278 	__le32	s_first_error_line;	/* line number where error happened */
1279 	__le32	s_last_error_time;	/* most recent time of an error */
1280 	__le32	s_last_error_ino;	/* inode involved in last error */
1281 	__le32	s_last_error_line;	/* line number where error happened */
1282 	__le64	s_last_error_block;	/* block involved of last error */
1283 	__u8	s_last_error_func[32];	/* function where the error happened */
1284 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1285 	__u8	s_mount_opts[64];
1286 	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
1287 	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
1288 	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
1289 	__le32	s_backup_bgs[2];	/* groups with sparse_super2 SBs */
1290 	__u8	s_encrypt_algos[4];	/* Encryption algorithms in use  */
1291 	__u8	s_encrypt_pw_salt[16];	/* Salt used for string2key algorithm */
1292 	__le32	s_lpf_ino;		/* Location of the lost+found inode */
1293 	__le32	s_prj_quota_inum;	/* inode for tracking project quota */
1294 	__le32	s_checksum_seed;	/* crc32c(uuid) if csum_seed set */
1295 	__le32	s_reserved[98];		/* Padding to the end of the block */
1296 	__le32	s_checksum;		/* crc32c(superblock) */
1297 };
1298 
1299 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1300 
1301 #ifdef __KERNEL__
1302 
1303 /*
1304  * run-time mount flags
1305  */
1306 #define EXT4_MF_MNTDIR_SAMPLED		0x0001
1307 #define EXT4_MF_FS_ABORTED		0x0002	/* Fatal error detected */
1308 #define EXT4_MF_TEST_DUMMY_ENCRYPTION	0x0004
1309 
1310 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1311 #define DUMMY_ENCRYPTION_ENABLED(sbi) (unlikely((sbi)->s_mount_flags & \
1312 						EXT4_MF_TEST_DUMMY_ENCRYPTION))
1313 #else
1314 #define DUMMY_ENCRYPTION_ENABLED(sbi) (0)
1315 #endif
1316 
1317 /* Number of quota types we support */
1318 #define EXT4_MAXQUOTAS 3
1319 
1320 /*
1321  * fourth extended-fs super-block data in memory
1322  */
1323 struct ext4_sb_info {
1324 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
1325 	unsigned long s_inodes_per_block;/* Number of inodes per block */
1326 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
1327 	unsigned long s_clusters_per_group; /* Number of clusters in a group */
1328 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
1329 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
1330 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
1331 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
1332 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1333 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1334 	unsigned long s_overhead;  /* # of fs overhead clusters */
1335 	unsigned int s_cluster_ratio;	/* Number of blocks per cluster */
1336 	unsigned int s_cluster_bits;	/* log2 of s_cluster_ratio */
1337 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
1338 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
1339 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
1340 	struct buffer_head **s_group_desc;
1341 	unsigned int s_mount_opt;
1342 	unsigned int s_mount_opt2;
1343 	unsigned int s_mount_flags;
1344 	unsigned int s_def_mount_opt;
1345 	ext4_fsblk_t s_sb_block;
1346 	atomic64_t s_resv_clusters;
1347 	kuid_t s_resuid;
1348 	kgid_t s_resgid;
1349 	unsigned short s_mount_state;
1350 	unsigned short s_pad;
1351 	int s_addr_per_block_bits;
1352 	int s_desc_per_block_bits;
1353 	int s_inode_size;
1354 	int s_first_ino;
1355 	unsigned int s_inode_readahead_blks;
1356 	unsigned int s_inode_goal;
1357 	u32 s_hash_seed[4];
1358 	int s_def_hash_version;
1359 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
1360 	struct percpu_counter s_freeclusters_counter;
1361 	struct percpu_counter s_freeinodes_counter;
1362 	struct percpu_counter s_dirs_counter;
1363 	struct percpu_counter s_dirtyclusters_counter;
1364 	struct blockgroup_lock *s_blockgroup_lock;
1365 	struct proc_dir_entry *s_proc;
1366 	struct kobject s_kobj;
1367 	struct completion s_kobj_unregister;
1368 	struct super_block *s_sb;
1369 
1370 	/* Journaling */
1371 	struct journal_s *s_journal;
1372 	struct list_head s_orphan;
1373 	struct mutex s_orphan_lock;
1374 	unsigned long s_ext4_flags;		/* Ext4 superblock flags */
1375 	unsigned long s_commit_interval;
1376 	u32 s_max_batch_time;
1377 	u32 s_min_batch_time;
1378 	struct block_device *journal_bdev;
1379 #ifdef CONFIG_QUOTA
1380 	char *s_qf_names[EXT4_MAXQUOTAS];	/* Names of quota files with journalled quota */
1381 	int s_jquota_fmt;			/* Format of quota to use */
1382 #endif
1383 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1384 	struct rb_root system_blks;
1385 
1386 #ifdef EXTENTS_STATS
1387 	/* ext4 extents stats */
1388 	unsigned long s_ext_min;
1389 	unsigned long s_ext_max;
1390 	unsigned long s_depth_max;
1391 	spinlock_t s_ext_stats_lock;
1392 	unsigned long s_ext_blocks;
1393 	unsigned long s_ext_extents;
1394 #endif
1395 
1396 	/* for buddy allocator */
1397 	struct ext4_group_info ***s_group_info;
1398 	struct inode *s_buddy_cache;
1399 	spinlock_t s_md_lock;
1400 	unsigned short *s_mb_offsets;
1401 	unsigned int *s_mb_maxs;
1402 	unsigned int s_group_info_size;
1403 	unsigned int s_mb_free_pending;
1404 	struct list_head s_freed_data_list;	/* List of blocks to be freed
1405 						   after commit completed */
1406 
1407 	/* tunables */
1408 	unsigned long s_stripe;
1409 	unsigned int s_mb_stream_request;
1410 	unsigned int s_mb_max_to_scan;
1411 	unsigned int s_mb_min_to_scan;
1412 	unsigned int s_mb_stats;
1413 	unsigned int s_mb_order2_reqs;
1414 	unsigned int s_mb_group_prealloc;
1415 	unsigned int s_max_dir_size_kb;
1416 	/* where last allocation was done - for stream allocation */
1417 	unsigned long s_mb_last_group;
1418 	unsigned long s_mb_last_start;
1419 
1420 	/* stats for buddy allocator */
1421 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1422 	atomic_t s_bal_success;	/* we found long enough chunks */
1423 	atomic_t s_bal_allocated;	/* in blocks */
1424 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1425 	atomic_t s_bal_goals;	/* goal hits */
1426 	atomic_t s_bal_breaks;	/* too long searches */
1427 	atomic_t s_bal_2orders;	/* 2^order hits */
1428 	spinlock_t s_bal_lock;
1429 	unsigned long s_mb_buddies_generated;
1430 	unsigned long long s_mb_generation_time;
1431 	atomic_t s_mb_lost_chunks;
1432 	atomic_t s_mb_preallocated;
1433 	atomic_t s_mb_discarded;
1434 	atomic_t s_lock_busy;
1435 
1436 	/* locality groups */
1437 	struct ext4_locality_group __percpu *s_locality_groups;
1438 
1439 	/* for write statistics */
1440 	unsigned long s_sectors_written_start;
1441 	u64 s_kbytes_written;
1442 
1443 	/* the size of zero-out chunk */
1444 	unsigned int s_extent_max_zeroout_kb;
1445 
1446 	unsigned int s_log_groups_per_flex;
1447 	struct flex_groups *s_flex_groups;
1448 	ext4_group_t s_flex_groups_allocated;
1449 
1450 	/* workqueue for reserved extent conversions (buffered io) */
1451 	struct workqueue_struct *rsv_conversion_wq;
1452 
1453 	/* timer for periodic error stats printing */
1454 	struct timer_list s_err_report;
1455 
1456 	/* Lazy inode table initialization info */
1457 	struct ext4_li_request *s_li_request;
1458 	/* Wait multiplier for lazy initialization thread */
1459 	unsigned int s_li_wait_mult;
1460 
1461 	/* Kernel thread for multiple mount protection */
1462 	struct task_struct *s_mmp_tsk;
1463 
1464 	/* record the last minlen when FITRIM is called. */
1465 	atomic_t s_last_trim_minblks;
1466 
1467 	/* Reference to checksum algorithm driver via cryptoapi */
1468 	struct crypto_shash *s_chksum_driver;
1469 
1470 	/* Precomputed FS UUID checksum for seeding other checksums */
1471 	__u32 s_csum_seed;
1472 
1473 	/* Reclaim extents from extent status tree */
1474 	struct shrinker s_es_shrinker;
1475 	struct list_head s_es_list;	/* List of inodes with reclaimable extents */
1476 	long s_es_nr_inode;
1477 	struct ext4_es_stats s_es_stats;
1478 	struct mb_cache *s_ea_block_cache;
1479 	struct mb_cache *s_ea_inode_cache;
1480 	spinlock_t s_es_lock ____cacheline_aligned_in_smp;
1481 
1482 	/* Ratelimit ext4 messages. */
1483 	struct ratelimit_state s_err_ratelimit_state;
1484 	struct ratelimit_state s_warning_ratelimit_state;
1485 	struct ratelimit_state s_msg_ratelimit_state;
1486 
1487 	/* Barrier between changing inodes' journal flags and writepages ops. */
1488 	struct percpu_rw_semaphore s_journal_flag_rwsem;
1489 	struct dax_device *s_daxdev;
1490 };
1491 
1492 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1493 {
1494 	return sb->s_fs_info;
1495 }
1496 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1497 {
1498 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1499 }
1500 
1501 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1502 {
1503 	return ino == EXT4_ROOT_INO ||
1504 		ino == EXT4_USR_QUOTA_INO ||
1505 		ino == EXT4_GRP_QUOTA_INO ||
1506 		ino == EXT4_BOOT_LOADER_INO ||
1507 		ino == EXT4_JOURNAL_INO ||
1508 		ino == EXT4_RESIZE_INO ||
1509 		(ino >= EXT4_FIRST_INO(sb) &&
1510 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1511 }
1512 
1513 /*
1514  * Inode dynamic state flags
1515  */
1516 enum {
1517 	EXT4_STATE_JDATA,		/* journaled data exists */
1518 	EXT4_STATE_NEW,			/* inode is newly created */
1519 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1520 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1521 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1522 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1523 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1524 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1525 	EXT4_STATE_DIOREAD_LOCK,	/* Disable support for dio read
1526 					   nolocking */
1527 	EXT4_STATE_MAY_INLINE_DATA,	/* may have in-inode data */
1528 	EXT4_STATE_EXT_PRECACHED,	/* extents have been precached */
1529 	EXT4_STATE_LUSTRE_EA_INODE,	/* Lustre-style ea_inode */
1530 };
1531 
1532 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
1533 static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
1534 {									\
1535 	return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);	\
1536 }									\
1537 static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
1538 {									\
1539 	set_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1540 }									\
1541 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1542 {									\
1543 	clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1544 }
1545 
1546 /* Add these declarations here only so that these functions can be
1547  * found by name.  Otherwise, they are very hard to locate. */
1548 static inline int ext4_test_inode_flag(struct inode *inode, int bit);
1549 static inline void ext4_set_inode_flag(struct inode *inode, int bit);
1550 static inline void ext4_clear_inode_flag(struct inode *inode, int bit);
1551 EXT4_INODE_BIT_FNS(flag, flags, 0)
1552 
1553 /* Add these declarations here only so that these functions can be
1554  * found by name.  Otherwise, they are very hard to locate. */
1555 static inline int ext4_test_inode_state(struct inode *inode, int bit);
1556 static inline void ext4_set_inode_state(struct inode *inode, int bit);
1557 static inline void ext4_clear_inode_state(struct inode *inode, int bit);
1558 #if (BITS_PER_LONG < 64)
1559 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1560 
1561 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1562 {
1563 	(ei)->i_state_flags = 0;
1564 }
1565 #else
1566 EXT4_INODE_BIT_FNS(state, flags, 32)
1567 
1568 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1569 {
1570 	/* We depend on the fact that callers will set i_flags */
1571 }
1572 #endif
1573 #else
1574 /* Assume that user mode programs are passing in an ext4fs superblock, not
1575  * a kernel struct super_block.  This will allow us to call the feature-test
1576  * macros from user land. */
1577 #define EXT4_SB(sb)	(sb)
1578 #endif
1579 
1580 /*
1581  * Returns true if the inode is inode is encrypted
1582  */
1583 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1584 
1585 /*
1586  * Codes for operating systems
1587  */
1588 #define EXT4_OS_LINUX		0
1589 #define EXT4_OS_HURD		1
1590 #define EXT4_OS_MASIX		2
1591 #define EXT4_OS_FREEBSD		3
1592 #define EXT4_OS_LITES		4
1593 
1594 /*
1595  * Revision levels
1596  */
1597 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1598 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1599 
1600 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1601 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1602 
1603 #define EXT4_GOOD_OLD_INODE_SIZE 128
1604 
1605 /*
1606  * Feature set definitions
1607  */
1608 
1609 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1610 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1611 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1612 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1613 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1614 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1615 #define EXT4_FEATURE_COMPAT_SPARSE_SUPER2	0x0200
1616 
1617 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1618 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1619 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1620 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1621 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1622 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1623 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1624 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
1625 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
1626 /*
1627  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1628  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1629  * all other data structures' checksums.  However, the METADATA_CSUM and
1630  * GDT_CSUM bits are mutually exclusive.
1631  */
1632 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
1633 #define EXT4_FEATURE_RO_COMPAT_READONLY		0x1000
1634 #define EXT4_FEATURE_RO_COMPAT_PROJECT		0x2000
1635 
1636 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1637 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1638 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1639 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1640 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1641 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1642 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1643 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1644 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1645 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1646 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1647 #define EXT4_FEATURE_INCOMPAT_CSUM_SEED		0x2000
1648 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
1649 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA	0x8000 /* data in inode */
1650 #define EXT4_FEATURE_INCOMPAT_ENCRYPT		0x10000
1651 
1652 #define EXT4_FEATURE_COMPAT_FUNCS(name, flagname) \
1653 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1654 { \
1655 	return ((EXT4_SB(sb)->s_es->s_feature_compat & \
1656 		cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname)) != 0); \
1657 } \
1658 static inline void ext4_set_feature_##name(struct super_block *sb) \
1659 { \
1660 	EXT4_SB(sb)->s_es->s_feature_compat |= \
1661 		cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname); \
1662 } \
1663 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1664 { \
1665 	EXT4_SB(sb)->s_es->s_feature_compat &= \
1666 		~cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname); \
1667 }
1668 
1669 #define EXT4_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
1670 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1671 { \
1672 	return ((EXT4_SB(sb)->s_es->s_feature_ro_compat & \
1673 		cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname)) != 0); \
1674 } \
1675 static inline void ext4_set_feature_##name(struct super_block *sb) \
1676 { \
1677 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= \
1678 		cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname); \
1679 } \
1680 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1681 { \
1682 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= \
1683 		~cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname); \
1684 }
1685 
1686 #define EXT4_FEATURE_INCOMPAT_FUNCS(name, flagname) \
1687 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1688 { \
1689 	return ((EXT4_SB(sb)->s_es->s_feature_incompat & \
1690 		cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname)) != 0); \
1691 } \
1692 static inline void ext4_set_feature_##name(struct super_block *sb) \
1693 { \
1694 	EXT4_SB(sb)->s_es->s_feature_incompat |= \
1695 		cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname); \
1696 } \
1697 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1698 { \
1699 	EXT4_SB(sb)->s_es->s_feature_incompat &= \
1700 		~cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname); \
1701 }
1702 
1703 EXT4_FEATURE_COMPAT_FUNCS(dir_prealloc,		DIR_PREALLOC)
1704 EXT4_FEATURE_COMPAT_FUNCS(imagic_inodes,	IMAGIC_INODES)
1705 EXT4_FEATURE_COMPAT_FUNCS(journal,		HAS_JOURNAL)
1706 EXT4_FEATURE_COMPAT_FUNCS(xattr,		EXT_ATTR)
1707 EXT4_FEATURE_COMPAT_FUNCS(resize_inode,		RESIZE_INODE)
1708 EXT4_FEATURE_COMPAT_FUNCS(dir_index,		DIR_INDEX)
1709 EXT4_FEATURE_COMPAT_FUNCS(sparse_super2,	SPARSE_SUPER2)
1710 
1711 EXT4_FEATURE_RO_COMPAT_FUNCS(sparse_super,	SPARSE_SUPER)
1712 EXT4_FEATURE_RO_COMPAT_FUNCS(large_file,	LARGE_FILE)
1713 EXT4_FEATURE_RO_COMPAT_FUNCS(btree_dir,		BTREE_DIR)
1714 EXT4_FEATURE_RO_COMPAT_FUNCS(huge_file,		HUGE_FILE)
1715 EXT4_FEATURE_RO_COMPAT_FUNCS(gdt_csum,		GDT_CSUM)
1716 EXT4_FEATURE_RO_COMPAT_FUNCS(dir_nlink,		DIR_NLINK)
1717 EXT4_FEATURE_RO_COMPAT_FUNCS(extra_isize,	EXTRA_ISIZE)
1718 EXT4_FEATURE_RO_COMPAT_FUNCS(quota,		QUOTA)
1719 EXT4_FEATURE_RO_COMPAT_FUNCS(bigalloc,		BIGALLOC)
1720 EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum,	METADATA_CSUM)
1721 EXT4_FEATURE_RO_COMPAT_FUNCS(readonly,		READONLY)
1722 EXT4_FEATURE_RO_COMPAT_FUNCS(project,		PROJECT)
1723 
1724 EXT4_FEATURE_INCOMPAT_FUNCS(compression,	COMPRESSION)
1725 EXT4_FEATURE_INCOMPAT_FUNCS(filetype,		FILETYPE)
1726 EXT4_FEATURE_INCOMPAT_FUNCS(journal_needs_recovery,	RECOVER)
1727 EXT4_FEATURE_INCOMPAT_FUNCS(journal_dev,	JOURNAL_DEV)
1728 EXT4_FEATURE_INCOMPAT_FUNCS(meta_bg,		META_BG)
1729 EXT4_FEATURE_INCOMPAT_FUNCS(extents,		EXTENTS)
1730 EXT4_FEATURE_INCOMPAT_FUNCS(64bit,		64BIT)
1731 EXT4_FEATURE_INCOMPAT_FUNCS(mmp,		MMP)
1732 EXT4_FEATURE_INCOMPAT_FUNCS(flex_bg,		FLEX_BG)
1733 EXT4_FEATURE_INCOMPAT_FUNCS(ea_inode,		EA_INODE)
1734 EXT4_FEATURE_INCOMPAT_FUNCS(dirdata,		DIRDATA)
1735 EXT4_FEATURE_INCOMPAT_FUNCS(csum_seed,		CSUM_SEED)
1736 EXT4_FEATURE_INCOMPAT_FUNCS(largedir,		LARGEDIR)
1737 EXT4_FEATURE_INCOMPAT_FUNCS(inline_data,	INLINE_DATA)
1738 EXT4_FEATURE_INCOMPAT_FUNCS(encrypt,		ENCRYPT)
1739 
1740 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1741 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1742 					 EXT4_FEATURE_INCOMPAT_META_BG)
1743 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1744 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1745 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1746 
1747 #define EXT3_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1748 #define EXT3_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1749 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1750 					 EXT4_FEATURE_INCOMPAT_META_BG)
1751 #define EXT3_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1752 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1753 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1754 
1755 #define EXT4_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1756 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1757 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1758 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1759 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1760 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1761 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1762 					 EXT4_FEATURE_INCOMPAT_EA_INODE| \
1763 					 EXT4_FEATURE_INCOMPAT_MMP | \
1764 					 EXT4_FEATURE_INCOMPAT_INLINE_DATA | \
1765 					 EXT4_FEATURE_INCOMPAT_ENCRYPT | \
1766 					 EXT4_FEATURE_INCOMPAT_CSUM_SEED | \
1767 					 EXT4_FEATURE_INCOMPAT_LARGEDIR)
1768 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1769 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1770 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1771 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1772 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1773 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1774 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1775 					 EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1776 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1777 					 EXT4_FEATURE_RO_COMPAT_QUOTA |\
1778 					 EXT4_FEATURE_RO_COMPAT_PROJECT)
1779 
1780 #define EXTN_FEATURE_FUNCS(ver) \
1781 static inline bool ext4_has_unknown_ext##ver##_compat_features(struct super_block *sb) \
1782 { \
1783 	return ((EXT4_SB(sb)->s_es->s_feature_compat & \
1784 		cpu_to_le32(~EXT##ver##_FEATURE_COMPAT_SUPP)) != 0); \
1785 } \
1786 static inline bool ext4_has_unknown_ext##ver##_ro_compat_features(struct super_block *sb) \
1787 { \
1788 	return ((EXT4_SB(sb)->s_es->s_feature_ro_compat & \
1789 		cpu_to_le32(~EXT##ver##_FEATURE_RO_COMPAT_SUPP)) != 0); \
1790 } \
1791 static inline bool ext4_has_unknown_ext##ver##_incompat_features(struct super_block *sb) \
1792 { \
1793 	return ((EXT4_SB(sb)->s_es->s_feature_incompat & \
1794 		cpu_to_le32(~EXT##ver##_FEATURE_INCOMPAT_SUPP)) != 0); \
1795 }
1796 
1797 EXTN_FEATURE_FUNCS(2)
1798 EXTN_FEATURE_FUNCS(3)
1799 EXTN_FEATURE_FUNCS(4)
1800 
1801 static inline bool ext4_has_compat_features(struct super_block *sb)
1802 {
1803 	return (EXT4_SB(sb)->s_es->s_feature_compat != 0);
1804 }
1805 static inline bool ext4_has_ro_compat_features(struct super_block *sb)
1806 {
1807 	return (EXT4_SB(sb)->s_es->s_feature_ro_compat != 0);
1808 }
1809 static inline bool ext4_has_incompat_features(struct super_block *sb)
1810 {
1811 	return (EXT4_SB(sb)->s_es->s_feature_incompat != 0);
1812 }
1813 
1814 /*
1815  * Superblock flags
1816  */
1817 #define EXT4_FLAGS_RESIZING	0
1818 #define EXT4_FLAGS_SHUTDOWN	1
1819 
1820 static inline int ext4_forced_shutdown(struct ext4_sb_info *sbi)
1821 {
1822 	return test_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);
1823 }
1824 
1825 
1826 /*
1827  * Default values for user and/or group using reserved blocks
1828  */
1829 #define	EXT4_DEF_RESUID		0
1830 #define	EXT4_DEF_RESGID		0
1831 
1832 /*
1833  * Default project ID
1834  */
1835 #define	EXT4_DEF_PROJID		0
1836 
1837 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1838 
1839 /*
1840  * Default mount options
1841  */
1842 #define EXT4_DEFM_DEBUG		0x0001
1843 #define EXT4_DEFM_BSDGROUPS	0x0002
1844 #define EXT4_DEFM_XATTR_USER	0x0004
1845 #define EXT4_DEFM_ACL		0x0008
1846 #define EXT4_DEFM_UID16		0x0010
1847 #define EXT4_DEFM_JMODE		0x0060
1848 #define EXT4_DEFM_JMODE_DATA	0x0020
1849 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1850 #define EXT4_DEFM_JMODE_WBACK	0x0060
1851 #define EXT4_DEFM_NOBARRIER	0x0100
1852 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1853 #define EXT4_DEFM_DISCARD	0x0400
1854 #define EXT4_DEFM_NODELALLOC	0x0800
1855 
1856 /*
1857  * Default journal batch times
1858  */
1859 #define EXT4_DEF_MIN_BATCH_TIME	0
1860 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1861 
1862 /*
1863  * Minimum number of groups in a flexgroup before we separate out
1864  * directories into the first block group of a flexgroup
1865  */
1866 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1867 
1868 /*
1869  * Structure of a directory entry
1870  */
1871 #define EXT4_NAME_LEN 255
1872 
1873 struct ext4_dir_entry {
1874 	__le32	inode;			/* Inode number */
1875 	__le16	rec_len;		/* Directory entry length */
1876 	__le16	name_len;		/* Name length */
1877 	char	name[EXT4_NAME_LEN];	/* File name */
1878 };
1879 
1880 /*
1881  * The new version of the directory entry.  Since EXT4 structures are
1882  * stored in intel byte order, and the name_len field could never be
1883  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1884  * file_type field.
1885  */
1886 struct ext4_dir_entry_2 {
1887 	__le32	inode;			/* Inode number */
1888 	__le16	rec_len;		/* Directory entry length */
1889 	__u8	name_len;		/* Name length */
1890 	__u8	file_type;
1891 	char	name[EXT4_NAME_LEN];	/* File name */
1892 };
1893 
1894 /*
1895  * This is a bogus directory entry at the end of each leaf block that
1896  * records checksums.
1897  */
1898 struct ext4_dir_entry_tail {
1899 	__le32	det_reserved_zero1;	/* Pretend to be unused */
1900 	__le16	det_rec_len;		/* 12 */
1901 	__u8	det_reserved_zero2;	/* Zero name length */
1902 	__u8	det_reserved_ft;	/* 0xDE, fake file type */
1903 	__le32	det_checksum;		/* crc32c(uuid+inum+dirblock) */
1904 };
1905 
1906 #define EXT4_DIRENT_TAIL(block, blocksize) \
1907 	((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1908 					((blocksize) - \
1909 					 sizeof(struct ext4_dir_entry_tail))))
1910 
1911 /*
1912  * Ext4 directory file types.  Only the low 3 bits are used.  The
1913  * other bits are reserved for now.
1914  */
1915 #define EXT4_FT_UNKNOWN		0
1916 #define EXT4_FT_REG_FILE	1
1917 #define EXT4_FT_DIR		2
1918 #define EXT4_FT_CHRDEV		3
1919 #define EXT4_FT_BLKDEV		4
1920 #define EXT4_FT_FIFO		5
1921 #define EXT4_FT_SOCK		6
1922 #define EXT4_FT_SYMLINK		7
1923 
1924 #define EXT4_FT_MAX		8
1925 
1926 #define EXT4_FT_DIR_CSUM	0xDE
1927 
1928 /*
1929  * EXT4_DIR_PAD defines the directory entries boundaries
1930  *
1931  * NOTE: It must be a multiple of 4
1932  */
1933 #define EXT4_DIR_PAD			4
1934 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1935 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1936 					 ~EXT4_DIR_ROUND)
1937 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1938 
1939 /*
1940  * If we ever get support for fs block sizes > page_size, we'll need
1941  * to remove the #if statements in the next two functions...
1942  */
1943 static inline unsigned int
1944 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1945 {
1946 	unsigned len = le16_to_cpu(dlen);
1947 
1948 #if (PAGE_SIZE >= 65536)
1949 	if (len == EXT4_MAX_REC_LEN || len == 0)
1950 		return blocksize;
1951 	return (len & 65532) | ((len & 3) << 16);
1952 #else
1953 	return len;
1954 #endif
1955 }
1956 
1957 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1958 {
1959 	if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1960 		BUG();
1961 #if (PAGE_SIZE >= 65536)
1962 	if (len < 65536)
1963 		return cpu_to_le16(len);
1964 	if (len == blocksize) {
1965 		if (blocksize == 65536)
1966 			return cpu_to_le16(EXT4_MAX_REC_LEN);
1967 		else
1968 			return cpu_to_le16(0);
1969 	}
1970 	return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1971 #else
1972 	return cpu_to_le16(len);
1973 #endif
1974 }
1975 
1976 /*
1977  * Hash Tree Directory indexing
1978  * (c) Daniel Phillips, 2001
1979  */
1980 
1981 #define is_dx(dir) (ext4_has_feature_dir_index((dir)->i_sb) && \
1982 		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1983 #define EXT4_DIR_LINK_MAX(dir) unlikely((dir)->i_nlink >= EXT4_LINK_MAX && \
1984 		    !(ext4_has_feature_dir_nlink((dir)->i_sb) && is_dx(dir)))
1985 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1986 
1987 /* Legal values for the dx_root hash_version field: */
1988 
1989 #define DX_HASH_LEGACY			0
1990 #define DX_HASH_HALF_MD4		1
1991 #define DX_HASH_TEA			2
1992 #define DX_HASH_LEGACY_UNSIGNED		3
1993 #define DX_HASH_HALF_MD4_UNSIGNED	4
1994 #define DX_HASH_TEA_UNSIGNED		5
1995 
1996 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1997 			      const void *address, unsigned int length)
1998 {
1999 	struct {
2000 		struct shash_desc shash;
2001 		char ctx[4];
2002 	} desc;
2003 
2004 	BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
2005 
2006 	desc.shash.tfm = sbi->s_chksum_driver;
2007 	desc.shash.flags = 0;
2008 	*(u32 *)desc.ctx = crc;
2009 
2010 	BUG_ON(crypto_shash_update(&desc.shash, address, length));
2011 
2012 	return *(u32 *)desc.ctx;
2013 }
2014 
2015 #ifdef __KERNEL__
2016 
2017 /* hash info structure used by the directory hash */
2018 struct dx_hash_info
2019 {
2020 	u32		hash;
2021 	u32		minor_hash;
2022 	int		hash_version;
2023 	u32		*seed;
2024 };
2025 
2026 
2027 /* 32 and 64 bit signed EOF for dx directories */
2028 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
2029 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
2030 
2031 
2032 /*
2033  * Control parameters used by ext4_htree_next_block
2034  */
2035 #define HASH_NB_ALWAYS		1
2036 
2037 struct ext4_filename {
2038 	const struct qstr *usr_fname;
2039 	struct fscrypt_str disk_name;
2040 	struct dx_hash_info hinfo;
2041 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2042 	struct fscrypt_str crypto_buf;
2043 #endif
2044 };
2045 
2046 #define fname_name(p) ((p)->disk_name.name)
2047 #define fname_len(p)  ((p)->disk_name.len)
2048 
2049 /*
2050  * Describe an inode's exact location on disk and in memory
2051  */
2052 struct ext4_iloc
2053 {
2054 	struct buffer_head *bh;
2055 	unsigned long offset;
2056 	ext4_group_t block_group;
2057 };
2058 
2059 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
2060 {
2061 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
2062 }
2063 
2064 static inline bool ext4_is_quota_file(struct inode *inode)
2065 {
2066 	return IS_NOQUOTA(inode) &&
2067 	       !(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL);
2068 }
2069 
2070 /*
2071  * This structure is stuffed into the struct file's private_data field
2072  * for directories.  It is where we put information so that we can do
2073  * readdir operations in hash tree order.
2074  */
2075 struct dir_private_info {
2076 	struct rb_root	root;
2077 	struct rb_node	*curr_node;
2078 	struct fname	*extra_fname;
2079 	loff_t		last_pos;
2080 	__u32		curr_hash;
2081 	__u32		curr_minor_hash;
2082 	__u32		next_hash;
2083 };
2084 
2085 /* calculate the first block number of the group */
2086 static inline ext4_fsblk_t
2087 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
2088 {
2089 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
2090 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
2091 }
2092 
2093 /*
2094  * Special error return code only used by dx_probe() and its callers.
2095  */
2096 #define ERR_BAD_DX_DIR	(-(MAX_ERRNO - 1))
2097 
2098 /* htree levels for ext4 */
2099 #define	EXT4_HTREE_LEVEL_COMPAT	2
2100 #define	EXT4_HTREE_LEVEL	3
2101 
2102 static inline int ext4_dir_htree_level(struct super_block *sb)
2103 {
2104 	return ext4_has_feature_largedir(sb) ?
2105 		EXT4_HTREE_LEVEL : EXT4_HTREE_LEVEL_COMPAT;
2106 }
2107 
2108 /*
2109  * Timeout and state flag for lazy initialization inode thread.
2110  */
2111 #define EXT4_DEF_LI_WAIT_MULT			10
2112 #define EXT4_DEF_LI_MAX_START_DELAY		5
2113 #define EXT4_LAZYINIT_QUIT			0x0001
2114 #define EXT4_LAZYINIT_RUNNING			0x0002
2115 
2116 /*
2117  * Lazy inode table initialization info
2118  */
2119 struct ext4_lazy_init {
2120 	unsigned long		li_state;
2121 	struct list_head	li_request_list;
2122 	struct mutex		li_list_mtx;
2123 };
2124 
2125 struct ext4_li_request {
2126 	struct super_block	*lr_super;
2127 	struct ext4_sb_info	*lr_sbi;
2128 	ext4_group_t		lr_next_group;
2129 	struct list_head	lr_request;
2130 	unsigned long		lr_next_sched;
2131 	unsigned long		lr_timeout;
2132 };
2133 
2134 struct ext4_features {
2135 	struct kobject f_kobj;
2136 	struct completion f_kobj_unregister;
2137 };
2138 
2139 /*
2140  * This structure will be used for multiple mount protection. It will be
2141  * written into the block number saved in the s_mmp_block field in the
2142  * superblock. Programs that check MMP should assume that if
2143  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
2144  * to use the filesystem, regardless of how old the timestamp is.
2145  */
2146 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
2147 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
2148 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
2149 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
2150 
2151 struct mmp_struct {
2152 	__le32	mmp_magic;		/* Magic number for MMP */
2153 	__le32	mmp_seq;		/* Sequence no. updated periodically */
2154 
2155 	/*
2156 	 * mmp_time, mmp_nodename & mmp_bdevname are only used for information
2157 	 * purposes and do not affect the correctness of the algorithm
2158 	 */
2159 	__le64	mmp_time;		/* Time last updated */
2160 	char	mmp_nodename[64];	/* Node which last updated MMP block */
2161 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
2162 
2163 	/*
2164 	 * mmp_check_interval is used to verify if the MMP block has been
2165 	 * updated on the block device. The value is updated based on the
2166 	 * maximum time to write the MMP block during an update cycle.
2167 	 */
2168 	__le16	mmp_check_interval;
2169 
2170 	__le16	mmp_pad1;
2171 	__le32	mmp_pad2[226];
2172 	__le32	mmp_checksum;		/* crc32c(uuid+mmp_block) */
2173 };
2174 
2175 /* arguments passed to the mmp thread */
2176 struct mmpd_data {
2177 	struct buffer_head *bh; /* bh from initial read_mmp_block() */
2178 	struct super_block *sb;  /* super block of the fs */
2179 };
2180 
2181 /*
2182  * Check interval multiplier
2183  * The MMP block is written every update interval and initially checked every
2184  * update interval x the multiplier (the value is then adapted based on the
2185  * write latency). The reason is that writes can be delayed under load and we
2186  * don't want readers to incorrectly assume that the filesystem is no longer
2187  * in use.
2188  */
2189 #define EXT4_MMP_CHECK_MULT		2UL
2190 
2191 /*
2192  * Minimum interval for MMP checking in seconds.
2193  */
2194 #define EXT4_MMP_MIN_CHECK_INTERVAL	5UL
2195 
2196 /*
2197  * Maximum interval for MMP checking in seconds.
2198  */
2199 #define EXT4_MMP_MAX_CHECK_INTERVAL	300UL
2200 
2201 /*
2202  * Function prototypes
2203  */
2204 
2205 /*
2206  * Ok, these declarations are also in <linux/kernel.h> but none of the
2207  * ext4 source programs needs to include it so they are duplicated here.
2208  */
2209 # define NORET_TYPE	/**/
2210 # define ATTRIB_NORET	__attribute__((noreturn))
2211 # define NORET_AND	noreturn,
2212 
2213 /* bitmap.c */
2214 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
2215 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
2216 				struct ext4_group_desc *gdp,
2217 				struct buffer_head *bh, int sz);
2218 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
2219 				  struct ext4_group_desc *gdp,
2220 				  struct buffer_head *bh, int sz);
2221 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
2222 				struct ext4_group_desc *gdp,
2223 				struct buffer_head *bh);
2224 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
2225 				  struct ext4_group_desc *gdp,
2226 				  struct buffer_head *bh);
2227 
2228 /* balloc.c */
2229 extern void ext4_get_group_no_and_offset(struct super_block *sb,
2230 					 ext4_fsblk_t blocknr,
2231 					 ext4_group_t *blockgrpp,
2232 					 ext4_grpblk_t *offsetp);
2233 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
2234 					  ext4_fsblk_t block);
2235 
2236 extern unsigned int ext4_block_group(struct super_block *sb,
2237 			ext4_fsblk_t blocknr);
2238 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
2239 			ext4_fsblk_t blocknr);
2240 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
2241 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
2242 			ext4_group_t group);
2243 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
2244 					 ext4_fsblk_t goal,
2245 					 unsigned int flags,
2246 					 unsigned long *count,
2247 					 int *errp);
2248 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
2249 				    s64 nclusters, unsigned int flags);
2250 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
2251 extern void ext4_check_blocks_bitmap(struct super_block *);
2252 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
2253 						    ext4_group_t block_group,
2254 						    struct buffer_head ** bh);
2255 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
2256 
2257 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
2258 						ext4_group_t block_group);
2259 extern int ext4_wait_block_bitmap(struct super_block *sb,
2260 				  ext4_group_t block_group,
2261 				  struct buffer_head *bh);
2262 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
2263 						  ext4_group_t block_group);
2264 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
2265 					      ext4_group_t block_group,
2266 					      struct ext4_group_desc *gdp);
2267 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
2268 
2269 static inline bool ext4_encrypted_inode(struct inode *inode)
2270 {
2271 	return ext4_test_inode_flag(inode, EXT4_INODE_ENCRYPT);
2272 }
2273 
2274 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2275 static inline int ext4_fname_setup_filename(struct inode *dir,
2276 			const struct qstr *iname,
2277 			int lookup, struct ext4_filename *fname)
2278 {
2279 	struct fscrypt_name name;
2280 	int err;
2281 
2282 	memset(fname, 0, sizeof(struct ext4_filename));
2283 
2284 	err = fscrypt_setup_filename(dir, iname, lookup, &name);
2285 
2286 	fname->usr_fname = name.usr_fname;
2287 	fname->disk_name = name.disk_name;
2288 	fname->hinfo.hash = name.hash;
2289 	fname->hinfo.minor_hash = name.minor_hash;
2290 	fname->crypto_buf = name.crypto_buf;
2291 	return err;
2292 }
2293 
2294 static inline void ext4_fname_free_filename(struct ext4_filename *fname)
2295 {
2296 	struct fscrypt_name name;
2297 
2298 	name.crypto_buf = fname->crypto_buf;
2299 	fscrypt_free_filename(&name);
2300 
2301 	fname->crypto_buf.name = NULL;
2302 	fname->usr_fname = NULL;
2303 	fname->disk_name.name = NULL;
2304 }
2305 #else
2306 static inline int ext4_fname_setup_filename(struct inode *dir,
2307 		const struct qstr *iname,
2308 		int lookup, struct ext4_filename *fname)
2309 {
2310 	fname->usr_fname = iname;
2311 	fname->disk_name.name = (unsigned char *) iname->name;
2312 	fname->disk_name.len = iname->len;
2313 	return 0;
2314 }
2315 static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
2316 
2317 #endif
2318 
2319 /* dir.c */
2320 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
2321 				  struct file *,
2322 				  struct ext4_dir_entry_2 *,
2323 				  struct buffer_head *, char *, int,
2324 				  unsigned int);
2325 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)	\
2326 	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
2327 					(de), (bh), (buf), (size), (offset)))
2328 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
2329 				__u32 minor_hash,
2330 				struct ext4_dir_entry_2 *dirent,
2331 				struct fscrypt_str *ent_name);
2332 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
2333 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
2334 			     struct buffer_head *bh,
2335 			     void *buf, int buf_size,
2336 			     struct ext4_filename *fname,
2337 			     struct ext4_dir_entry_2 **dest_de);
2338 void ext4_insert_dentry(struct inode *inode,
2339 			struct ext4_dir_entry_2 *de,
2340 			int buf_size,
2341 			struct ext4_filename *fname);
2342 static inline void ext4_update_dx_flag(struct inode *inode)
2343 {
2344 	if (!ext4_has_feature_dir_index(inode->i_sb))
2345 		ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
2346 }
2347 static const unsigned char ext4_filetype_table[] = {
2348 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
2349 };
2350 
2351 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
2352 {
2353 	if (!ext4_has_feature_filetype(sb) || filetype >= EXT4_FT_MAX)
2354 		return DT_UNKNOWN;
2355 
2356 	return ext4_filetype_table[filetype];
2357 }
2358 extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
2359 			     void *buf, int buf_size);
2360 
2361 /* fsync.c */
2362 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2363 
2364 /* hash.c */
2365 extern int ext4fs_dirhash(const char *name, int len, struct
2366 			  dx_hash_info *hinfo);
2367 
2368 /* ialloc.c */
2369 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
2370 				      const struct qstr *qstr, __u32 goal,
2371 				      uid_t *owner, __u32 i_flags,
2372 				      int handle_type, unsigned int line_no,
2373 				      int nblocks);
2374 
2375 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner, i_flags) \
2376 	__ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
2377 			 i_flags, 0, 0, 0)
2378 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
2379 				    type, nblocks)		    \
2380 	__ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
2381 			 0, (type), __LINE__, (nblocks))
2382 
2383 
2384 extern void ext4_free_inode(handle_t *, struct inode *);
2385 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2386 extern unsigned long ext4_count_free_inodes(struct super_block *);
2387 extern unsigned long ext4_count_dirs(struct super_block *);
2388 extern void ext4_check_inodes_bitmap(struct super_block *);
2389 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2390 extern int ext4_init_inode_table(struct super_block *sb,
2391 				 ext4_group_t group, int barrier);
2392 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2393 
2394 /* mballoc.c */
2395 extern const struct file_operations ext4_seq_mb_groups_fops;
2396 extern long ext4_mb_stats;
2397 extern long ext4_mb_max_to_scan;
2398 extern int ext4_mb_init(struct super_block *);
2399 extern int ext4_mb_release(struct super_block *);
2400 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2401 				struct ext4_allocation_request *, int *);
2402 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2403 extern void ext4_discard_preallocations(struct inode *);
2404 extern int __init ext4_init_mballoc(void);
2405 extern void ext4_exit_mballoc(void);
2406 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2407 			     struct buffer_head *bh, ext4_fsblk_t block,
2408 			     unsigned long count, int flags);
2409 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2410 				   ext4_group_t ngroups);
2411 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2412 		ext4_group_t i, struct ext4_group_desc *desc);
2413 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2414 				ext4_fsblk_t block, unsigned long count);
2415 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2416 extern void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid);
2417 
2418 /* inode.c */
2419 int ext4_inode_is_fast_symlink(struct inode *inode);
2420 struct buffer_head *ext4_getblk(handle_t *, struct inode *, ext4_lblk_t, int);
2421 struct buffer_head *ext4_bread(handle_t *, struct inode *, ext4_lblk_t, int);
2422 int ext4_bread_batch(struct inode *inode, ext4_lblk_t block, int bh_count,
2423 		     bool wait, struct buffer_head **bhs);
2424 int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
2425 			     struct buffer_head *bh_result, int create);
2426 int ext4_get_block(struct inode *inode, sector_t iblock,
2427 		   struct buffer_head *bh_result, int create);
2428 int ext4_dio_get_block(struct inode *inode, sector_t iblock,
2429 		       struct buffer_head *bh_result, int create);
2430 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2431 			   struct buffer_head *bh, int create);
2432 int ext4_walk_page_buffers(handle_t *handle,
2433 			   struct buffer_head *head,
2434 			   unsigned from,
2435 			   unsigned to,
2436 			   int *partial,
2437 			   int (*fn)(handle_t *handle,
2438 				     struct buffer_head *bh));
2439 int do_journal_get_write_access(handle_t *handle,
2440 				struct buffer_head *bh);
2441 #define FALL_BACK_TO_NONDELALLOC 1
2442 #define CONVERT_INLINE_DATA	 2
2443 
2444 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2445 extern struct inode *ext4_iget_normal(struct super_block *, unsigned long);
2446 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2447 extern int  ext4_setattr(struct dentry *, struct iattr *);
2448 extern int  ext4_getattr(const struct path *, struct kstat *, u32, unsigned int);
2449 extern void ext4_evict_inode(struct inode *);
2450 extern void ext4_clear_inode(struct inode *);
2451 extern int  ext4_file_getattr(const struct path *, struct kstat *, u32, unsigned int);
2452 extern int  ext4_sync_inode(handle_t *, struct inode *);
2453 extern void ext4_dirty_inode(struct inode *, int);
2454 extern int ext4_change_inode_journal_flag(struct inode *, int);
2455 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2456 extern int ext4_inode_attach_jinode(struct inode *inode);
2457 extern int ext4_can_truncate(struct inode *inode);
2458 extern int ext4_truncate(struct inode *);
2459 extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length);
2460 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2461 extern void ext4_set_inode_flags(struct inode *);
2462 extern int ext4_alloc_da_blocks(struct inode *inode);
2463 extern void ext4_set_aops(struct inode *inode);
2464 extern int ext4_writepage_trans_blocks(struct inode *);
2465 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2466 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
2467 			     loff_t lstart, loff_t lend);
2468 extern int ext4_page_mkwrite(struct vm_fault *vmf);
2469 extern int ext4_filemap_fault(struct vm_fault *vmf);
2470 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2471 extern int ext4_get_projid(struct inode *inode, kprojid_t *projid);
2472 extern void ext4_da_update_reserve_space(struct inode *inode,
2473 					int used, int quota_claim);
2474 extern int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk,
2475 			      ext4_fsblk_t pblk, ext4_lblk_t len);
2476 
2477 /* indirect.c */
2478 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2479 				struct ext4_map_blocks *map, int flags);
2480 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2481 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2482 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2483 extern int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
2484 				 ext4_lblk_t start, ext4_lblk_t end);
2485 
2486 /* ioctl.c */
2487 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2488 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2489 
2490 /* migrate.c */
2491 extern int ext4_ext_migrate(struct inode *);
2492 extern int ext4_ind_migrate(struct inode *inode);
2493 
2494 /* namei.c */
2495 extern int ext4_dirent_csum_verify(struct inode *inode,
2496 				   struct ext4_dir_entry *dirent);
2497 extern int ext4_orphan_add(handle_t *, struct inode *);
2498 extern int ext4_orphan_del(handle_t *, struct inode *);
2499 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2500 				__u32 start_minor_hash, __u32 *next_hash);
2501 extern int ext4_search_dir(struct buffer_head *bh,
2502 			   char *search_buf,
2503 			   int buf_size,
2504 			   struct inode *dir,
2505 			   struct ext4_filename *fname,
2506 			   unsigned int offset,
2507 			   struct ext4_dir_entry_2 **res_dir);
2508 extern int ext4_generic_delete_entry(handle_t *handle,
2509 				     struct inode *dir,
2510 				     struct ext4_dir_entry_2 *de_del,
2511 				     struct buffer_head *bh,
2512 				     void *entry_buf,
2513 				     int buf_size,
2514 				     int csum_size);
2515 extern bool ext4_empty_dir(struct inode *inode);
2516 
2517 /* resize.c */
2518 extern int ext4_group_add(struct super_block *sb,
2519 				struct ext4_new_group_data *input);
2520 extern int ext4_group_extend(struct super_block *sb,
2521 				struct ext4_super_block *es,
2522 				ext4_fsblk_t n_blocks_count);
2523 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2524 
2525 /* super.c */
2526 extern int ext4_seq_options_show(struct seq_file *seq, void *offset);
2527 extern int ext4_calculate_overhead(struct super_block *sb);
2528 extern void ext4_superblock_csum_set(struct super_block *sb);
2529 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2530 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2531 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2532 				    ext4_group_t ngroup);
2533 extern const char *ext4_decode_error(struct super_block *sb, int errno,
2534 				     char nbuf[16]);
2535 
2536 extern __printf(4, 5)
2537 void __ext4_error(struct super_block *, const char *, unsigned int,
2538 		  const char *, ...);
2539 extern __printf(5, 6)
2540 void __ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2541 		      const char *, ...);
2542 extern __printf(5, 6)
2543 void __ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2544 		     const char *, ...);
2545 extern void __ext4_std_error(struct super_block *, const char *,
2546 			     unsigned int, int);
2547 extern __printf(4, 5)
2548 void __ext4_abort(struct super_block *, const char *, unsigned int,
2549 		  const char *, ...);
2550 extern __printf(4, 5)
2551 void __ext4_warning(struct super_block *, const char *, unsigned int,
2552 		    const char *, ...);
2553 extern __printf(4, 5)
2554 void __ext4_warning_inode(const struct inode *inode, const char *function,
2555 			  unsigned int line, const char *fmt, ...);
2556 extern __printf(3, 4)
2557 void __ext4_msg(struct super_block *, const char *, const char *, ...);
2558 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2559 			   const char *, unsigned int, const char *);
2560 extern __printf(7, 8)
2561 void __ext4_grp_locked_error(const char *, unsigned int,
2562 			     struct super_block *, ext4_group_t,
2563 			     unsigned long, ext4_fsblk_t,
2564 			     const char *, ...);
2565 
2566 #define EXT4_ERROR_INODE(inode, fmt, a...) \
2567 	ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
2568 
2569 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)			\
2570 	ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
2571 
2572 #define EXT4_ERROR_FILE(file, block, fmt, a...)				\
2573 	ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
2574 
2575 #ifdef CONFIG_PRINTK
2576 
2577 #define ext4_error_inode(inode, func, line, block, fmt, ...)		\
2578 	__ext4_error_inode(inode, func, line, block, fmt, ##__VA_ARGS__)
2579 #define ext4_error_file(file, func, line, block, fmt, ...)		\
2580 	__ext4_error_file(file, func, line, block, fmt, ##__VA_ARGS__)
2581 #define ext4_error(sb, fmt, ...)					\
2582 	__ext4_error(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2583 #define ext4_abort(sb, fmt, ...)					\
2584 	__ext4_abort(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2585 #define ext4_warning(sb, fmt, ...)					\
2586 	__ext4_warning(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2587 #define ext4_warning_inode(inode, fmt, ...)				\
2588 	__ext4_warning_inode(inode, __func__, __LINE__, fmt, ##__VA_ARGS__)
2589 #define ext4_msg(sb, level, fmt, ...)				\
2590 	__ext4_msg(sb, level, fmt, ##__VA_ARGS__)
2591 #define dump_mmp_msg(sb, mmp, msg)					\
2592 	__dump_mmp_msg(sb, mmp, __func__, __LINE__, msg)
2593 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)		\
2594 	__ext4_grp_locked_error(__func__, __LINE__, sb, grp, ino, block, \
2595 				fmt, ##__VA_ARGS__)
2596 
2597 #else
2598 
2599 #define ext4_error_inode(inode, func, line, block, fmt, ...)		\
2600 do {									\
2601 	no_printk(fmt, ##__VA_ARGS__);					\
2602 	__ext4_error_inode(inode, "", 0, block, " ");			\
2603 } while (0)
2604 #define ext4_error_file(file, func, line, block, fmt, ...)		\
2605 do {									\
2606 	no_printk(fmt, ##__VA_ARGS__);					\
2607 	__ext4_error_file(file, "", 0, block, " ");			\
2608 } while (0)
2609 #define ext4_error(sb, fmt, ...)					\
2610 do {									\
2611 	no_printk(fmt, ##__VA_ARGS__);					\
2612 	__ext4_error(sb, "", 0, " ");					\
2613 } while (0)
2614 #define ext4_abort(sb, fmt, ...)					\
2615 do {									\
2616 	no_printk(fmt, ##__VA_ARGS__);					\
2617 	__ext4_abort(sb, "", 0, " ");					\
2618 } while (0)
2619 #define ext4_warning(sb, fmt, ...)					\
2620 do {									\
2621 	no_printk(fmt, ##__VA_ARGS__);					\
2622 	__ext4_warning(sb, "", 0, " ");					\
2623 } while (0)
2624 #define ext4_warning_inode(inode, fmt, ...)				\
2625 do {									\
2626 	no_printk(fmt, ##__VA_ARGS__);					\
2627 	__ext4_warning_inode(inode, "", 0, " ");			\
2628 } while (0)
2629 #define ext4_msg(sb, level, fmt, ...)					\
2630 do {									\
2631 	no_printk(fmt, ##__VA_ARGS__);					\
2632 	__ext4_msg(sb, "", " ");					\
2633 } while (0)
2634 #define dump_mmp_msg(sb, mmp, msg)					\
2635 	__dump_mmp_msg(sb, mmp, "", 0, "")
2636 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)		\
2637 do {									\
2638 	no_printk(fmt, ##__VA_ARGS__);				\
2639 	__ext4_grp_locked_error("", 0, sb, grp, ino, block, " ");	\
2640 } while (0)
2641 
2642 #endif
2643 
2644 extern void ext4_update_dynamic_rev(struct super_block *sb);
2645 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2646 					__u32 compat);
2647 extern int ext4_update_rocompat_feature(handle_t *handle,
2648 					struct super_block *sb,	__u32 rocompat);
2649 extern int ext4_update_incompat_feature(handle_t *handle,
2650 					struct super_block *sb,	__u32 incompat);
2651 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2652 				      struct ext4_group_desc *bg);
2653 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2654 				      struct ext4_group_desc *bg);
2655 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2656 				     struct ext4_group_desc *bg);
2657 extern __u32 ext4_free_group_clusters(struct super_block *sb,
2658 				      struct ext4_group_desc *bg);
2659 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2660 				 struct ext4_group_desc *bg);
2661 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2662 				struct ext4_group_desc *bg);
2663 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2664 				   struct ext4_group_desc *bg);
2665 extern void ext4_block_bitmap_set(struct super_block *sb,
2666 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2667 extern void ext4_inode_bitmap_set(struct super_block *sb,
2668 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2669 extern void ext4_inode_table_set(struct super_block *sb,
2670 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
2671 extern void ext4_free_group_clusters_set(struct super_block *sb,
2672 					 struct ext4_group_desc *bg,
2673 					 __u32 count);
2674 extern void ext4_free_inodes_set(struct super_block *sb,
2675 				struct ext4_group_desc *bg, __u32 count);
2676 extern void ext4_used_dirs_set(struct super_block *sb,
2677 				struct ext4_group_desc *bg, __u32 count);
2678 extern void ext4_itable_unused_set(struct super_block *sb,
2679 				   struct ext4_group_desc *bg, __u32 count);
2680 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2681 				       struct ext4_group_desc *gdp);
2682 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2683 				     struct ext4_group_desc *gdp);
2684 extern int ext4_register_li_request(struct super_block *sb,
2685 				    ext4_group_t first_not_zeroed);
2686 
2687 static inline int ext4_has_metadata_csum(struct super_block *sb)
2688 {
2689 	WARN_ON_ONCE(ext4_has_feature_metadata_csum(sb) &&
2690 		     !EXT4_SB(sb)->s_chksum_driver);
2691 
2692 	return ext4_has_feature_metadata_csum(sb) &&
2693 	       (EXT4_SB(sb)->s_chksum_driver != NULL);
2694 }
2695 
2696 static inline int ext4_has_group_desc_csum(struct super_block *sb)
2697 {
2698 	return ext4_has_feature_gdt_csum(sb) || ext4_has_metadata_csum(sb);
2699 }
2700 
2701 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2702 {
2703 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2704 		le32_to_cpu(es->s_blocks_count_lo);
2705 }
2706 
2707 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2708 {
2709 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2710 		le32_to_cpu(es->s_r_blocks_count_lo);
2711 }
2712 
2713 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2714 {
2715 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2716 		le32_to_cpu(es->s_free_blocks_count_lo);
2717 }
2718 
2719 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2720 					 ext4_fsblk_t blk)
2721 {
2722 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2723 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2724 }
2725 
2726 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2727 					      ext4_fsblk_t blk)
2728 {
2729 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2730 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2731 }
2732 
2733 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2734 					   ext4_fsblk_t blk)
2735 {
2736 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2737 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2738 }
2739 
2740 static inline loff_t ext4_isize(struct super_block *sb,
2741 				struct ext4_inode *raw_inode)
2742 {
2743 	if (ext4_has_feature_largedir(sb) ||
2744 	    S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2745 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2746 			le32_to_cpu(raw_inode->i_size_lo);
2747 
2748 	return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2749 }
2750 
2751 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2752 {
2753 	raw_inode->i_size_lo = cpu_to_le32(i_size);
2754 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2755 }
2756 
2757 static inline
2758 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2759 					    ext4_group_t group)
2760 {
2761 	 struct ext4_group_info ***grp_info;
2762 	 long indexv, indexh;
2763 	 BUG_ON(group >= EXT4_SB(sb)->s_groups_count);
2764 	 grp_info = EXT4_SB(sb)->s_group_info;
2765 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2766 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2767 	 return grp_info[indexv][indexh];
2768 }
2769 
2770 /*
2771  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2772  * the locking protocol documented in the comments of ext4_group_add()
2773  * in resize.c
2774  */
2775 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2776 {
2777 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
2778 
2779 	smp_rmb();
2780 	return ngroups;
2781 }
2782 
2783 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2784 					     ext4_group_t block_group)
2785 {
2786 	return block_group >> sbi->s_log_groups_per_flex;
2787 }
2788 
2789 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2790 {
2791 	return 1 << sbi->s_log_groups_per_flex;
2792 }
2793 
2794 #define ext4_std_error(sb, errno)				\
2795 do {								\
2796 	if ((errno))						\
2797 		__ext4_std_error((sb), __func__, __LINE__, (errno));	\
2798 } while (0)
2799 
2800 #ifdef CONFIG_SMP
2801 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2802  * counters. So we need to make sure we have free clusters more
2803  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2804  */
2805 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2806 #else
2807 #define EXT4_FREECLUSTERS_WATERMARK 0
2808 #endif
2809 
2810 /* Update i_disksize. Requires i_mutex to avoid races with truncate */
2811 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2812 {
2813 	WARN_ON_ONCE(S_ISREG(inode->i_mode) &&
2814 		     !inode_is_locked(inode));
2815 	down_write(&EXT4_I(inode)->i_data_sem);
2816 	if (newsize > EXT4_I(inode)->i_disksize)
2817 		EXT4_I(inode)->i_disksize = newsize;
2818 	up_write(&EXT4_I(inode)->i_data_sem);
2819 }
2820 
2821 /* Update i_size, i_disksize. Requires i_mutex to avoid races with truncate */
2822 static inline int ext4_update_inode_size(struct inode *inode, loff_t newsize)
2823 {
2824 	int changed = 0;
2825 
2826 	if (newsize > inode->i_size) {
2827 		i_size_write(inode, newsize);
2828 		changed = 1;
2829 	}
2830 	if (newsize > EXT4_I(inode)->i_disksize) {
2831 		ext4_update_i_disksize(inode, newsize);
2832 		changed |= 2;
2833 	}
2834 	return changed;
2835 }
2836 
2837 int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset,
2838 				      loff_t len);
2839 
2840 struct ext4_group_info {
2841 	unsigned long   bb_state;
2842 	struct rb_root  bb_free_root;
2843 	ext4_grpblk_t	bb_first_free;	/* first free block */
2844 	ext4_grpblk_t	bb_free;	/* total free blocks */
2845 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
2846 	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
2847 	struct          list_head bb_prealloc_list;
2848 #ifdef DOUBLE_CHECK
2849 	void            *bb_bitmap;
2850 #endif
2851 	struct rw_semaphore alloc_sem;
2852 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
2853 					 * regions, index is order.
2854 					 * bb_counters[3] = 5 means
2855 					 * 5 free 8-block regions. */
2856 };
2857 
2858 #define EXT4_GROUP_INFO_NEED_INIT_BIT		0
2859 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT		1
2860 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT	2
2861 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT	3
2862 
2863 #define EXT4_MB_GRP_NEED_INIT(grp)	\
2864 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2865 #define EXT4_MB_GRP_BBITMAP_CORRUPT(grp)	\
2866 	(test_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2867 #define EXT4_MB_GRP_IBITMAP_CORRUPT(grp)	\
2868 	(test_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2869 
2870 #define EXT4_MB_GRP_WAS_TRIMMED(grp)	\
2871 	(test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2872 #define EXT4_MB_GRP_SET_TRIMMED(grp)	\
2873 	(set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2874 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)	\
2875 	(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2876 
2877 #define EXT4_MAX_CONTENTION		8
2878 #define EXT4_CONTENTION_THRESHOLD	2
2879 
2880 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2881 					      ext4_group_t group)
2882 {
2883 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2884 }
2885 
2886 /*
2887  * Returns true if the filesystem is busy enough that attempts to
2888  * access the block group locks has run into contention.
2889  */
2890 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2891 {
2892 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2893 }
2894 
2895 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2896 {
2897 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2898 	if (spin_trylock(lock))
2899 		/*
2900 		 * We're able to grab the lock right away, so drop the
2901 		 * lock contention counter.
2902 		 */
2903 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2904 	else {
2905 		/*
2906 		 * The lock is busy, so bump the contention counter,
2907 		 * and then wait on the spin lock.
2908 		 */
2909 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2910 				  EXT4_MAX_CONTENTION);
2911 		spin_lock(lock);
2912 	}
2913 }
2914 
2915 static inline void ext4_unlock_group(struct super_block *sb,
2916 					ext4_group_t group)
2917 {
2918 	spin_unlock(ext4_group_lock_ptr(sb, group));
2919 }
2920 
2921 /*
2922  * Block validity checking
2923  */
2924 #define ext4_check_indirect_blockref(inode, bh)				\
2925 	ext4_check_blockref(__func__, __LINE__, inode,			\
2926 			    (__le32 *)(bh)->b_data,			\
2927 			    EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2928 
2929 #define ext4_ind_check_inode(inode)					\
2930 	ext4_check_blockref(__func__, __LINE__, inode,			\
2931 			    EXT4_I(inode)->i_data,			\
2932 			    EXT4_NDIR_BLOCKS)
2933 
2934 /*
2935  * Inodes and files operations
2936  */
2937 
2938 /* dir.c */
2939 extern const struct file_operations ext4_dir_operations;
2940 
2941 /* file.c */
2942 extern const struct inode_operations ext4_file_inode_operations;
2943 extern const struct file_operations ext4_file_operations;
2944 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2945 
2946 /* inline.c */
2947 extern int ext4_get_max_inline_size(struct inode *inode);
2948 extern int ext4_find_inline_data_nolock(struct inode *inode);
2949 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
2950 				 unsigned int len);
2951 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
2952 
2953 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
2954 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
2955 					 struct inode *inode,
2956 					 loff_t pos, unsigned len,
2957 					 unsigned flags,
2958 					 struct page **pagep);
2959 extern int ext4_write_inline_data_end(struct inode *inode,
2960 				      loff_t pos, unsigned len,
2961 				      unsigned copied,
2962 				      struct page *page);
2963 extern struct buffer_head *
2964 ext4_journalled_write_inline_data(struct inode *inode,
2965 				  unsigned len,
2966 				  struct page *page);
2967 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
2968 					   struct inode *inode,
2969 					   loff_t pos, unsigned len,
2970 					   unsigned flags,
2971 					   struct page **pagep,
2972 					   void **fsdata);
2973 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
2974 					 unsigned len, unsigned copied,
2975 					 struct page *page);
2976 extern int ext4_try_add_inline_entry(handle_t *handle,
2977 				     struct ext4_filename *fname,
2978 				     struct inode *dir, struct inode *inode);
2979 extern int ext4_try_create_inline_dir(handle_t *handle,
2980 				      struct inode *parent,
2981 				      struct inode *inode);
2982 extern int ext4_read_inline_dir(struct file *filp,
2983 				struct dir_context *ctx,
2984 				int *has_inline_data);
2985 extern int htree_inlinedir_to_tree(struct file *dir_file,
2986 				   struct inode *dir, ext4_lblk_t block,
2987 				   struct dx_hash_info *hinfo,
2988 				   __u32 start_hash, __u32 start_minor_hash,
2989 				   int *has_inline_data);
2990 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
2991 					struct ext4_filename *fname,
2992 					struct ext4_dir_entry_2 **res_dir,
2993 					int *has_inline_data);
2994 extern int ext4_delete_inline_entry(handle_t *handle,
2995 				    struct inode *dir,
2996 				    struct ext4_dir_entry_2 *de_del,
2997 				    struct buffer_head *bh,
2998 				    int *has_inline_data);
2999 extern bool empty_inline_dir(struct inode *dir, int *has_inline_data);
3000 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
3001 					struct ext4_dir_entry_2 **parent_de,
3002 					int *retval);
3003 extern int ext4_inline_data_fiemap(struct inode *inode,
3004 				   struct fiemap_extent_info *fieinfo,
3005 				   int *has_inline, __u64 start, __u64 len);
3006 
3007 struct iomap;
3008 extern int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap);
3009 
3010 extern int ext4_try_to_evict_inline_data(handle_t *handle,
3011 					 struct inode *inode,
3012 					 int needed);
3013 extern int ext4_inline_data_truncate(struct inode *inode, int *has_inline);
3014 
3015 extern int ext4_convert_inline_data(struct inode *inode);
3016 
3017 static inline int ext4_has_inline_data(struct inode *inode)
3018 {
3019 	return ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA) &&
3020 	       EXT4_I(inode)->i_inline_off;
3021 }
3022 
3023 /* namei.c */
3024 extern const struct inode_operations ext4_dir_inode_operations;
3025 extern const struct inode_operations ext4_special_inode_operations;
3026 extern struct dentry *ext4_get_parent(struct dentry *child);
3027 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
3028 				 struct ext4_dir_entry_2 *de,
3029 				 int blocksize, int csum_size,
3030 				 unsigned int parent_ino, int dotdot_real_len);
3031 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
3032 				   unsigned int blocksize);
3033 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
3034 					 struct inode *inode,
3035 					 struct buffer_head *bh);
3036 #define S_SHIFT 12
3037 static const unsigned char ext4_type_by_mode[(S_IFMT >> S_SHIFT) + 1] = {
3038 	[S_IFREG >> S_SHIFT]	= EXT4_FT_REG_FILE,
3039 	[S_IFDIR >> S_SHIFT]	= EXT4_FT_DIR,
3040 	[S_IFCHR >> S_SHIFT]	= EXT4_FT_CHRDEV,
3041 	[S_IFBLK >> S_SHIFT]	= EXT4_FT_BLKDEV,
3042 	[S_IFIFO >> S_SHIFT]	= EXT4_FT_FIFO,
3043 	[S_IFSOCK >> S_SHIFT]	= EXT4_FT_SOCK,
3044 	[S_IFLNK >> S_SHIFT]	= EXT4_FT_SYMLINK,
3045 };
3046 
3047 static inline void ext4_set_de_type(struct super_block *sb,
3048 				struct ext4_dir_entry_2 *de,
3049 				umode_t mode) {
3050 	if (ext4_has_feature_filetype(sb))
3051 		de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
3052 }
3053 
3054 /* readpages.c */
3055 extern int ext4_mpage_readpages(struct address_space *mapping,
3056 				struct list_head *pages, struct page *page,
3057 				unsigned nr_pages);
3058 
3059 /* symlink.c */
3060 extern const struct inode_operations ext4_encrypted_symlink_inode_operations;
3061 extern const struct inode_operations ext4_symlink_inode_operations;
3062 extern const struct inode_operations ext4_fast_symlink_inode_operations;
3063 
3064 /* sysfs.c */
3065 extern int ext4_register_sysfs(struct super_block *sb);
3066 extern void ext4_unregister_sysfs(struct super_block *sb);
3067 extern int __init ext4_init_sysfs(void);
3068 extern void ext4_exit_sysfs(void);
3069 
3070 /* block_validity */
3071 extern void ext4_release_system_zone(struct super_block *sb);
3072 extern int ext4_setup_system_zone(struct super_block *sb);
3073 extern int __init ext4_init_system_zone(void);
3074 extern void ext4_exit_system_zone(void);
3075 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
3076 				 ext4_fsblk_t start_blk,
3077 				 unsigned int count);
3078 extern int ext4_check_blockref(const char *, unsigned int,
3079 			       struct inode *, __le32 *, unsigned int);
3080 
3081 /* extents.c */
3082 struct ext4_ext_path;
3083 struct ext4_extent;
3084 
3085 /*
3086  * Maximum number of logical blocks in a file; ext4_extent's ee_block is
3087  * __le32.
3088  */
3089 #define EXT_MAX_BLOCKS	0xffffffff
3090 
3091 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
3092 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
3093 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
3094 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
3095 			       struct ext4_map_blocks *map, int flags);
3096 extern int ext4_ext_truncate(handle_t *, struct inode *);
3097 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
3098 				 ext4_lblk_t end);
3099 extern void ext4_ext_init(struct super_block *);
3100 extern void ext4_ext_release(struct super_block *);
3101 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
3102 			  loff_t len);
3103 extern int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
3104 					  loff_t offset, ssize_t len);
3105 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
3106 			   struct ext4_map_blocks *map, int flags);
3107 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
3108 					 ext4_lblk_t lblocks);
3109 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
3110 						   int num,
3111 						   struct ext4_ext_path *path);
3112 extern int ext4_can_extents_be_merged(struct inode *inode,
3113 				      struct ext4_extent *ex1,
3114 				      struct ext4_extent *ex2);
3115 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
3116 				  struct ext4_ext_path **,
3117 				  struct ext4_extent *, int);
3118 extern struct ext4_ext_path *ext4_find_extent(struct inode *, ext4_lblk_t,
3119 					      struct ext4_ext_path **,
3120 					      int flags);
3121 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
3122 extern int ext4_ext_check_inode(struct inode *inode);
3123 extern int ext4_find_delalloc_range(struct inode *inode,
3124 				    ext4_lblk_t lblk_start,
3125 				    ext4_lblk_t lblk_end);
3126 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
3127 extern ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path);
3128 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3129 			__u64 start, __u64 len);
3130 extern int ext4_ext_precache(struct inode *inode);
3131 extern int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len);
3132 extern int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len);
3133 extern int ext4_swap_extents(handle_t *handle, struct inode *inode1,
3134 				struct inode *inode2, ext4_lblk_t lblk1,
3135 			     ext4_lblk_t lblk2,  ext4_lblk_t count,
3136 			     int mark_unwritten,int *err);
3137 
3138 /* move_extent.c */
3139 extern void ext4_double_down_write_data_sem(struct inode *first,
3140 					    struct inode *second);
3141 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
3142 					  struct inode *donor_inode);
3143 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
3144 			     __u64 start_orig, __u64 start_donor,
3145 			     __u64 len, __u64 *moved_len);
3146 
3147 /* page-io.c */
3148 extern int __init ext4_init_pageio(void);
3149 extern void ext4_exit_pageio(void);
3150 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
3151 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
3152 extern int ext4_put_io_end(ext4_io_end_t *io_end);
3153 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
3154 extern void ext4_io_submit_init(struct ext4_io_submit *io,
3155 				struct writeback_control *wbc);
3156 extern void ext4_end_io_rsv_work(struct work_struct *work);
3157 extern void ext4_io_submit(struct ext4_io_submit *io);
3158 extern int ext4_bio_write_page(struct ext4_io_submit *io,
3159 			       struct page *page,
3160 			       int len,
3161 			       struct writeback_control *wbc,
3162 			       bool keep_towrite);
3163 
3164 /* mmp.c */
3165 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
3166 
3167 /*
3168  * Add new method to test whether block and inode bitmaps are properly
3169  * initialized. With uninit_bg reading the block from disk is not enough
3170  * to mark the bitmap uptodate. We need to also zero-out the bitmap
3171  */
3172 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
3173 
3174 static inline int bitmap_uptodate(struct buffer_head *bh)
3175 {
3176 	return (buffer_uptodate(bh) &&
3177 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
3178 }
3179 static inline void set_bitmap_uptodate(struct buffer_head *bh)
3180 {
3181 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
3182 }
3183 
3184 /*
3185  * Disable DIO read nolock optimization, so new dioreaders will be forced
3186  * to grab i_mutex
3187  */
3188 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
3189 {
3190 	ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
3191 	smp_mb();
3192 }
3193 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
3194 {
3195 	smp_mb();
3196 	ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
3197 }
3198 
3199 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
3200 
3201 /* For ioend & aio unwritten conversion wait queues */
3202 #define EXT4_WQ_HASH_SZ		37
3203 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
3204 					    EXT4_WQ_HASH_SZ])
3205 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
3206 
3207 extern int ext4_resize_begin(struct super_block *sb);
3208 extern void ext4_resize_end(struct super_block *sb);
3209 
3210 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
3211 					      struct ext4_io_end *io_end)
3212 {
3213 	if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
3214 		io_end->flag |= EXT4_IO_END_UNWRITTEN;
3215 		atomic_inc(&EXT4_I(inode)->i_unwritten);
3216 	}
3217 }
3218 
3219 static inline void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end)
3220 {
3221 	struct inode *inode = io_end->inode;
3222 
3223 	if (io_end->flag & EXT4_IO_END_UNWRITTEN) {
3224 		io_end->flag &= ~EXT4_IO_END_UNWRITTEN;
3225 		/* Wake up anyone waiting on unwritten extent conversion */
3226 		if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten))
3227 			wake_up_all(ext4_ioend_wq(inode));
3228 	}
3229 }
3230 
3231 extern const struct iomap_ops ext4_iomap_ops;
3232 
3233 #endif	/* __KERNEL__ */
3234 
3235 #define EFSBADCRC	EBADMSG		/* Bad CRC detected */
3236 #define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
3237 
3238 #endif	/* _EXT4_H */
3239