xref: /openbmc/linux/fs/ext4/ext4.h (revision 33ac9dba)
1 /*
2  *  ext4.h
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/include/linux/minix_fs.h
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  */
15 
16 #ifndef _EXT4_H
17 #define _EXT4_H
18 
19 #include <linux/types.h>
20 #include <linux/blkdev.h>
21 #include <linux/magic.h>
22 #include <linux/jbd2.h>
23 #include <linux/quota.h>
24 #include <linux/rwsem.h>
25 #include <linux/rbtree.h>
26 #include <linux/seqlock.h>
27 #include <linux/mutex.h>
28 #include <linux/timer.h>
29 #include <linux/wait.h>
30 #include <linux/blockgroup_lock.h>
31 #include <linux/percpu_counter.h>
32 #include <linux/ratelimit.h>
33 #include <crypto/hash.h>
34 #include <linux/falloc.h>
35 #ifdef __KERNEL__
36 #include <linux/compat.h>
37 #endif
38 
39 /*
40  * The fourth extended filesystem constants/structures
41  */
42 
43 /*
44  * Define EXT4FS_DEBUG to produce debug messages
45  */
46 #undef EXT4FS_DEBUG
47 
48 /*
49  * Debug code
50  */
51 #ifdef EXT4FS_DEBUG
52 #define ext4_debug(f, a...)						\
53 	do {								\
54 		printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",	\
55 			__FILE__, __LINE__, __func__);			\
56 		printk(KERN_DEBUG f, ## a);				\
57 	} while (0)
58 #else
59 #define ext4_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
60 #endif
61 
62 /*
63  * Turn on EXT_DEBUG to get lots of info about extents operations.
64  */
65 #define EXT_DEBUG__
66 #ifdef EXT_DEBUG
67 #define ext_debug(fmt, ...)	printk(fmt, ##__VA_ARGS__)
68 #else
69 #define ext_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
70 #endif
71 
72 #define EXT4_ERROR_INODE(inode, fmt, a...) \
73 	ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
74 
75 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)			\
76 	ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
77 
78 #define EXT4_ERROR_FILE(file, block, fmt, a...)				\
79 	ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
80 
81 /* data type for block offset of block group */
82 typedef int ext4_grpblk_t;
83 
84 /* data type for filesystem-wide blocks number */
85 typedef unsigned long long ext4_fsblk_t;
86 
87 /* data type for file logical block number */
88 typedef __u32 ext4_lblk_t;
89 
90 /* data type for block group number */
91 typedef unsigned int ext4_group_t;
92 
93 /*
94  * Flags used in mballoc's allocation_context flags field.
95  *
96  * Also used to show what's going on for debugging purposes when the
97  * flag field is exported via the traceport interface
98  */
99 
100 /* prefer goal again. length */
101 #define EXT4_MB_HINT_MERGE		0x0001
102 /* blocks already reserved */
103 #define EXT4_MB_HINT_RESERVED		0x0002
104 /* metadata is being allocated */
105 #define EXT4_MB_HINT_METADATA		0x0004
106 /* first blocks in the file */
107 #define EXT4_MB_HINT_FIRST		0x0008
108 /* search for the best chunk */
109 #define EXT4_MB_HINT_BEST		0x0010
110 /* data is being allocated */
111 #define EXT4_MB_HINT_DATA		0x0020
112 /* don't preallocate (for tails) */
113 #define EXT4_MB_HINT_NOPREALLOC		0x0040
114 /* allocate for locality group */
115 #define EXT4_MB_HINT_GROUP_ALLOC	0x0080
116 /* allocate goal blocks or none */
117 #define EXT4_MB_HINT_GOAL_ONLY		0x0100
118 /* goal is meaningful */
119 #define EXT4_MB_HINT_TRY_GOAL		0x0200
120 /* blocks already pre-reserved by delayed allocation */
121 #define EXT4_MB_DELALLOC_RESERVED	0x0400
122 /* We are doing stream allocation */
123 #define EXT4_MB_STREAM_ALLOC		0x0800
124 /* Use reserved root blocks if needed */
125 #define EXT4_MB_USE_ROOT_BLOCKS		0x1000
126 /* Use blocks from reserved pool */
127 #define EXT4_MB_USE_RESERVED		0x2000
128 
129 struct ext4_allocation_request {
130 	/* target inode for block we're allocating */
131 	struct inode *inode;
132 	/* how many blocks we want to allocate */
133 	unsigned int len;
134 	/* logical block in target inode */
135 	ext4_lblk_t logical;
136 	/* the closest logical allocated block to the left */
137 	ext4_lblk_t lleft;
138 	/* the closest logical allocated block to the right */
139 	ext4_lblk_t lright;
140 	/* phys. target (a hint) */
141 	ext4_fsblk_t goal;
142 	/* phys. block for the closest logical allocated block to the left */
143 	ext4_fsblk_t pleft;
144 	/* phys. block for the closest logical allocated block to the right */
145 	ext4_fsblk_t pright;
146 	/* flags. see above EXT4_MB_HINT_* */
147 	unsigned int flags;
148 };
149 
150 /*
151  * Logical to physical block mapping, used by ext4_map_blocks()
152  *
153  * This structure is used to pass requests into ext4_map_blocks() as
154  * well as to store the information returned by ext4_map_blocks().  It
155  * takes less room on the stack than a struct buffer_head.
156  */
157 #define EXT4_MAP_NEW		(1 << BH_New)
158 #define EXT4_MAP_MAPPED		(1 << BH_Mapped)
159 #define EXT4_MAP_UNWRITTEN	(1 << BH_Unwritten)
160 #define EXT4_MAP_BOUNDARY	(1 << BH_Boundary)
161 /* Sometimes (in the bigalloc case, from ext4_da_get_block_prep) the caller of
162  * ext4_map_blocks wants to know whether or not the underlying cluster has
163  * already been accounted for. EXT4_MAP_FROM_CLUSTER conveys to the caller that
164  * the requested mapping was from previously mapped (or delayed allocated)
165  * cluster. We use BH_AllocFromCluster only for this flag. BH_AllocFromCluster
166  * should never appear on buffer_head's state flags.
167  */
168 #define EXT4_MAP_FROM_CLUSTER	(1 << BH_AllocFromCluster)
169 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
170 				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
171 				 EXT4_MAP_FROM_CLUSTER)
172 
173 struct ext4_map_blocks {
174 	ext4_fsblk_t m_pblk;
175 	ext4_lblk_t m_lblk;
176 	unsigned int m_len;
177 	unsigned int m_flags;
178 };
179 
180 /*
181  * Flags for ext4_io_end->flags
182  */
183 #define	EXT4_IO_END_UNWRITTEN	0x0001
184 
185 /*
186  * For converting unwritten extents on a work queue. 'handle' is used for
187  * buffered writeback.
188  */
189 typedef struct ext4_io_end {
190 	struct list_head	list;		/* per-file finished IO list */
191 	handle_t		*handle;	/* handle reserved for extent
192 						 * conversion */
193 	struct inode		*inode;		/* file being written to */
194 	struct bio		*bio;		/* Linked list of completed
195 						 * bios covering the extent */
196 	unsigned int		flag;		/* unwritten or not */
197 	loff_t			offset;		/* offset in the file */
198 	ssize_t			size;		/* size of the extent */
199 	atomic_t		count;		/* reference counter */
200 } ext4_io_end_t;
201 
202 struct ext4_io_submit {
203 	int			io_op;
204 	struct bio		*io_bio;
205 	ext4_io_end_t		*io_end;
206 	sector_t		io_next_block;
207 };
208 
209 /*
210  * Special inodes numbers
211  */
212 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
213 #define EXT4_ROOT_INO		 2	/* Root inode */
214 #define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
215 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
216 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
217 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
218 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
219 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
220 
221 /* First non-reserved inode for old ext4 filesystems */
222 #define EXT4_GOOD_OLD_FIRST_INO	11
223 
224 /*
225  * Maximal count of links to a file
226  */
227 #define EXT4_LINK_MAX		65000
228 
229 /*
230  * Macro-instructions used to manage several block sizes
231  */
232 #define EXT4_MIN_BLOCK_SIZE		1024
233 #define	EXT4_MAX_BLOCK_SIZE		65536
234 #define EXT4_MIN_BLOCK_LOG_SIZE		10
235 #define EXT4_MAX_BLOCK_LOG_SIZE		16
236 #ifdef __KERNEL__
237 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
238 #else
239 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
240 #endif
241 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
242 #define EXT4_CLUSTER_SIZE(s)		(EXT4_BLOCK_SIZE(s) << \
243 					 EXT4_SB(s)->s_cluster_bits)
244 #ifdef __KERNEL__
245 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
246 # define EXT4_CLUSTER_BITS(s)		(EXT4_SB(s)->s_cluster_bits)
247 #else
248 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
249 #endif
250 #ifdef __KERNEL__
251 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
252 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
253 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
254 #else
255 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
256 				 EXT4_GOOD_OLD_INODE_SIZE : \
257 				 (s)->s_inode_size)
258 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
259 				 EXT4_GOOD_OLD_FIRST_INO : \
260 				 (s)->s_first_ino)
261 #endif
262 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
263 
264 /* Translate a block number to a cluster number */
265 #define EXT4_B2C(sbi, blk)	((blk) >> (sbi)->s_cluster_bits)
266 /* Translate a cluster number to a block number */
267 #define EXT4_C2B(sbi, cluster)	((cluster) << (sbi)->s_cluster_bits)
268 /* Translate # of blks to # of clusters */
269 #define EXT4_NUM_B2C(sbi, blks)	(((blks) + (sbi)->s_cluster_ratio - 1) >> \
270 				 (sbi)->s_cluster_bits)
271 /* Mask out the low bits to get the starting block of the cluster */
272 #define EXT4_PBLK_CMASK(s, pblk) ((pblk) &				\
273 				  ~((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
274 #define EXT4_LBLK_CMASK(s, lblk) ((lblk) &				\
275 				  ~((ext4_lblk_t) (s)->s_cluster_ratio - 1))
276 /* Get the cluster offset */
277 #define EXT4_PBLK_COFF(s, pblk) ((pblk) &				\
278 				 ((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
279 #define EXT4_LBLK_COFF(s, lblk) ((lblk) &				\
280 				 ((ext4_lblk_t) (s)->s_cluster_ratio - 1))
281 
282 /*
283  * Structure of a blocks group descriptor
284  */
285 struct ext4_group_desc
286 {
287 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
288 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
289 	__le32	bg_inode_table_lo;	/* Inodes table block */
290 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
291 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
292 	__le16	bg_used_dirs_count_lo;	/* Directories count */
293 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
294 	__le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
295 	__le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
296 	__le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
297 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
298 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
299 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
300 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
301 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
302 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
303 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
304 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
305 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
306 	__le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
307 	__le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
308 	__le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
309 	__u32   bg_reserved;
310 };
311 
312 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END	\
313 	(offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
314 	 sizeof(__le16))
315 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END	\
316 	(offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
317 	 sizeof(__le16))
318 
319 /*
320  * Structure of a flex block group info
321  */
322 
323 struct flex_groups {
324 	atomic64_t	free_clusters;
325 	atomic_t	free_inodes;
326 	atomic_t	used_dirs;
327 };
328 
329 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
330 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
331 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
332 
333 /*
334  * Macro-instructions used to manage group descriptors
335  */
336 #define EXT4_MIN_DESC_SIZE		32
337 #define EXT4_MIN_DESC_SIZE_64BIT	64
338 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
339 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
340 #ifdef __KERNEL__
341 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
342 # define EXT4_CLUSTERS_PER_GROUP(s)	(EXT4_SB(s)->s_clusters_per_group)
343 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
344 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
345 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
346 #else
347 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
348 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
349 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
350 #endif
351 
352 /*
353  * Constants relative to the data blocks
354  */
355 #define	EXT4_NDIR_BLOCKS		12
356 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
357 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
358 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
359 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
360 
361 /*
362  * Inode flags
363  */
364 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
365 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
366 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
367 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
368 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
369 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
370 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
371 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
372 /* Reserved for compression usage... */
373 #define EXT4_DIRTY_FL			0x00000100
374 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
375 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
376 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
377 /* End compression flags --- maybe not all used */
378 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
379 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
380 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
381 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
382 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
383 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
384 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
385 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
386 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
387 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
388 #define EXT4_INLINE_DATA_FL		0x10000000 /* Inode has inline data. */
389 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
390 
391 #define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
392 #define EXT4_FL_USER_MODIFIABLE		0x004380FF /* User modifiable flags */
393 
394 /* Flags that should be inherited by new inodes from their parent. */
395 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
396 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
397 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
398 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
399 
400 /* Flags that are appropriate for regular files (all but dir-specific ones). */
401 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
402 
403 /* Flags that are appropriate for non-directories/regular files. */
404 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
405 
406 /* Mask out flags that are inappropriate for the given type of inode. */
407 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
408 {
409 	if (S_ISDIR(mode))
410 		return flags;
411 	else if (S_ISREG(mode))
412 		return flags & EXT4_REG_FLMASK;
413 	else
414 		return flags & EXT4_OTHER_FLMASK;
415 }
416 
417 /*
418  * Inode flags used for atomic set/get
419  */
420 enum {
421 	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
422 	EXT4_INODE_UNRM		= 1,	/* Undelete */
423 	EXT4_INODE_COMPR	= 2,	/* Compress file */
424 	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
425 	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
426 	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
427 	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
428 	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
429 /* Reserved for compression usage... */
430 	EXT4_INODE_DIRTY	= 8,
431 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
432 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
433 	EXT4_INODE_ECOMPR	= 11,	/* Compression error */
434 /* End compression flags --- maybe not all used */
435 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
436 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
437 	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
438 	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
439 	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
440 	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
441 	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
442 	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
443 	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
444 	EXT4_INODE_EOFBLOCKS	= 22,	/* Blocks allocated beyond EOF */
445 	EXT4_INODE_INLINE_DATA	= 28,	/* Data in inode. */
446 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
447 };
448 
449 /*
450  * Since it's pretty easy to mix up bit numbers and hex values, we use a
451  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
452  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
453  * any extra space in the compiled kernel image, otherwise, the build will fail.
454  * It's important that these values are the same, since we are using
455  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
456  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
457  * values found in ext2, ext3 and ext4 filesystems, and of course the values
458  * defined in e2fsprogs.
459  *
460  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
461  */
462 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
463 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
464 
465 static inline void ext4_check_flag_values(void)
466 {
467 	CHECK_FLAG_VALUE(SECRM);
468 	CHECK_FLAG_VALUE(UNRM);
469 	CHECK_FLAG_VALUE(COMPR);
470 	CHECK_FLAG_VALUE(SYNC);
471 	CHECK_FLAG_VALUE(IMMUTABLE);
472 	CHECK_FLAG_VALUE(APPEND);
473 	CHECK_FLAG_VALUE(NODUMP);
474 	CHECK_FLAG_VALUE(NOATIME);
475 	CHECK_FLAG_VALUE(DIRTY);
476 	CHECK_FLAG_VALUE(COMPRBLK);
477 	CHECK_FLAG_VALUE(NOCOMPR);
478 	CHECK_FLAG_VALUE(ECOMPR);
479 	CHECK_FLAG_VALUE(INDEX);
480 	CHECK_FLAG_VALUE(IMAGIC);
481 	CHECK_FLAG_VALUE(JOURNAL_DATA);
482 	CHECK_FLAG_VALUE(NOTAIL);
483 	CHECK_FLAG_VALUE(DIRSYNC);
484 	CHECK_FLAG_VALUE(TOPDIR);
485 	CHECK_FLAG_VALUE(HUGE_FILE);
486 	CHECK_FLAG_VALUE(EXTENTS);
487 	CHECK_FLAG_VALUE(EA_INODE);
488 	CHECK_FLAG_VALUE(EOFBLOCKS);
489 	CHECK_FLAG_VALUE(INLINE_DATA);
490 	CHECK_FLAG_VALUE(RESERVED);
491 }
492 
493 /* Used to pass group descriptor data when online resize is done */
494 struct ext4_new_group_input {
495 	__u32 group;		/* Group number for this data */
496 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
497 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
498 	__u64 inode_table;	/* Absolute block number of inode table start */
499 	__u32 blocks_count;	/* Total number of blocks in this group */
500 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
501 	__u16 unused;
502 };
503 
504 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
505 struct compat_ext4_new_group_input {
506 	u32 group;
507 	compat_u64 block_bitmap;
508 	compat_u64 inode_bitmap;
509 	compat_u64 inode_table;
510 	u32 blocks_count;
511 	u16 reserved_blocks;
512 	u16 unused;
513 };
514 #endif
515 
516 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
517 struct ext4_new_group_data {
518 	__u32 group;
519 	__u64 block_bitmap;
520 	__u64 inode_bitmap;
521 	__u64 inode_table;
522 	__u32 blocks_count;
523 	__u16 reserved_blocks;
524 	__u16 unused;
525 	__u32 free_blocks_count;
526 };
527 
528 /* Indexes used to index group tables in ext4_new_group_data */
529 enum {
530 	BLOCK_BITMAP = 0,	/* block bitmap */
531 	INODE_BITMAP,		/* inode bitmap */
532 	INODE_TABLE,		/* inode tables */
533 	GROUP_TABLE_COUNT,
534 };
535 
536 /*
537  * Flags used by ext4_map_blocks()
538  */
539 	/* Allocate any needed blocks and/or convert an unwritten
540 	   extent to be an initialized ext4 */
541 #define EXT4_GET_BLOCKS_CREATE			0x0001
542 	/* Request the creation of an unwritten extent */
543 #define EXT4_GET_BLOCKS_UNWRIT_EXT		0x0002
544 #define EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT	(EXT4_GET_BLOCKS_UNWRIT_EXT|\
545 						 EXT4_GET_BLOCKS_CREATE)
546 	/* Caller is from the delayed allocation writeout path
547 	 * finally doing the actual allocation of delayed blocks */
548 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
549 	/* caller is from the direct IO path, request to creation of an
550 	unwritten extents if not allocated, split the unwritten
551 	extent if blocks has been preallocated already*/
552 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
553 #define EXT4_GET_BLOCKS_CONVERT			0x0010
554 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
555 					 EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
556 	/* Convert extent to initialized after IO complete */
557 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
558 					 EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
559 	/* Eventual metadata allocation (due to growing extent tree)
560 	 * should not fail, so try to use reserved blocks for that.*/
561 #define EXT4_GET_BLOCKS_METADATA_NOFAIL		0x0020
562 	/* Don't normalize allocation size (used for fallocate) */
563 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
564 	/* Request will not result in inode size update (user for fallocate) */
565 #define EXT4_GET_BLOCKS_KEEP_SIZE		0x0080
566 	/* Do not take i_data_sem locking in ext4_map_blocks */
567 #define EXT4_GET_BLOCKS_NO_LOCK			0x0100
568 	/* Do not put hole in extent cache */
569 #define EXT4_GET_BLOCKS_NO_PUT_HOLE		0x0200
570 	/* Convert written extents to unwritten */
571 #define EXT4_GET_BLOCKS_CONVERT_UNWRITTEN	0x0400
572 
573 /*
574  * The bit position of these flags must not overlap with any of the
575  * EXT4_GET_BLOCKS_*.  They are used by ext4_ext_find_extent(),
576  * read_extent_tree_block(), ext4_split_extent_at(),
577  * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf().
578  * EXT4_EX_NOCACHE is used to indicate that the we shouldn't be
579  * caching the extents when reading from the extent tree while a
580  * truncate or punch hole operation is in progress.
581  */
582 #define EXT4_EX_NOCACHE				0x0400
583 #define EXT4_EX_FORCE_CACHE			0x0800
584 
585 /*
586  * Flags used by ext4_free_blocks
587  */
588 #define EXT4_FREE_BLOCKS_METADATA	0x0001
589 #define EXT4_FREE_BLOCKS_FORGET		0x0002
590 #define EXT4_FREE_BLOCKS_VALIDATED	0x0004
591 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE	0x0008
592 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
593 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
594 
595 /*
596  * ioctl commands
597  */
598 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
599 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
600 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
601 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
602 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
603 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
604 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
605 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
606 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
607 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
608 #define EXT4_IOC_MIGRATE		_IO('f', 9)
609  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
610  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
611 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
612 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
613 #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
614 #define EXT4_IOC_SWAP_BOOT		_IO('f', 17)
615 #define EXT4_IOC_PRECACHE_EXTENTS	_IO('f', 18)
616 
617 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
618 /*
619  * ioctl commands in 32 bit emulation
620  */
621 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
622 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
623 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
624 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
625 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
626 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
627 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
628 #define EXT4_IOC32_GROUP_ADD		_IOW('f', 8, struct compat_ext4_new_group_input)
629 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
630 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
631 #endif
632 
633 /* Max physical block we can address w/o extents */
634 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
635 
636 /*
637  * Structure of an inode on the disk
638  */
639 struct ext4_inode {
640 	__le16	i_mode;		/* File mode */
641 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
642 	__le32	i_size_lo;	/* Size in bytes */
643 	__le32	i_atime;	/* Access time */
644 	__le32	i_ctime;	/* Inode Change time */
645 	__le32	i_mtime;	/* Modification time */
646 	__le32	i_dtime;	/* Deletion Time */
647 	__le16	i_gid;		/* Low 16 bits of Group Id */
648 	__le16	i_links_count;	/* Links count */
649 	__le32	i_blocks_lo;	/* Blocks count */
650 	__le32	i_flags;	/* File flags */
651 	union {
652 		struct {
653 			__le32  l_i_version;
654 		} linux1;
655 		struct {
656 			__u32  h_i_translator;
657 		} hurd1;
658 		struct {
659 			__u32  m_i_reserved1;
660 		} masix1;
661 	} osd1;				/* OS dependent 1 */
662 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
663 	__le32	i_generation;	/* File version (for NFS) */
664 	__le32	i_file_acl_lo;	/* File ACL */
665 	__le32	i_size_high;
666 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
667 	union {
668 		struct {
669 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
670 			__le16	l_i_file_acl_high;
671 			__le16	l_i_uid_high;	/* these 2 fields */
672 			__le16	l_i_gid_high;	/* were reserved2[0] */
673 			__le16	l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
674 			__le16	l_i_reserved;
675 		} linux2;
676 		struct {
677 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
678 			__u16	h_i_mode_high;
679 			__u16	h_i_uid_high;
680 			__u16	h_i_gid_high;
681 			__u32	h_i_author;
682 		} hurd2;
683 		struct {
684 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
685 			__le16	m_i_file_acl_high;
686 			__u32	m_i_reserved2[2];
687 		} masix2;
688 	} osd2;				/* OS dependent 2 */
689 	__le16	i_extra_isize;
690 	__le16	i_checksum_hi;	/* crc32c(uuid+inum+inode) BE */
691 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
692 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
693 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
694 	__le32  i_crtime;       /* File Creation time */
695 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
696 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
697 };
698 
699 struct move_extent {
700 	__u32 reserved;		/* should be zero */
701 	__u32 donor_fd;		/* donor file descriptor */
702 	__u64 orig_start;	/* logical start offset in block for orig */
703 	__u64 donor_start;	/* logical start offset in block for donor */
704 	__u64 len;		/* block length to be moved */
705 	__u64 moved_len;	/* moved block length */
706 };
707 
708 #define EXT4_EPOCH_BITS 2
709 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
710 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
711 
712 /*
713  * Extended fields will fit into an inode if the filesystem was formatted
714  * with large inodes (-I 256 or larger) and there are not currently any EAs
715  * consuming all of the available space. For new inodes we always reserve
716  * enough space for the kernel's known extended fields, but for inodes
717  * created with an old kernel this might not have been the case. None of
718  * the extended inode fields is critical for correct filesystem operation.
719  * This macro checks if a certain field fits in the inode. Note that
720  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
721  */
722 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
723 	((offsetof(typeof(*ext4_inode), field) +	\
724 	  sizeof((ext4_inode)->field))			\
725 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
726 	    (einode)->i_extra_isize))			\
727 
728 static inline __le32 ext4_encode_extra_time(struct timespec *time)
729 {
730        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
731 			   (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
732                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
733 }
734 
735 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
736 {
737        if (sizeof(time->tv_sec) > 4)
738 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
739 			       << 32;
740        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
741 }
742 
743 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
744 do {									       \
745 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
746 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
747 		(raw_inode)->xtime ## _extra =				       \
748 				ext4_encode_extra_time(&(inode)->xtime);       \
749 } while (0)
750 
751 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
752 do {									       \
753 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
754 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
755 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
756 		(raw_inode)->xtime ## _extra =				       \
757 				ext4_encode_extra_time(&(einode)->xtime);      \
758 } while (0)
759 
760 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
761 do {									       \
762 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
763 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
764 		ext4_decode_extra_time(&(inode)->xtime,			       \
765 				       raw_inode->xtime ## _extra);	       \
766 	else								       \
767 		(inode)->xtime.tv_nsec = 0;				       \
768 } while (0)
769 
770 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
771 do {									       \
772 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
773 		(einode)->xtime.tv_sec = 				       \
774 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
775 	else								       \
776 		(einode)->xtime.tv_sec = 0;				       \
777 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
778 		ext4_decode_extra_time(&(einode)->xtime,		       \
779 				       raw_inode->xtime ## _extra);	       \
780 	else								       \
781 		(einode)->xtime.tv_nsec = 0;				       \
782 } while (0)
783 
784 #define i_disk_version osd1.linux1.l_i_version
785 
786 #if defined(__KERNEL__) || defined(__linux__)
787 #define i_reserved1	osd1.linux1.l_i_reserved1
788 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
789 #define i_blocks_high	osd2.linux2.l_i_blocks_high
790 #define i_uid_low	i_uid
791 #define i_gid_low	i_gid
792 #define i_uid_high	osd2.linux2.l_i_uid_high
793 #define i_gid_high	osd2.linux2.l_i_gid_high
794 #define i_checksum_lo	osd2.linux2.l_i_checksum_lo
795 
796 #elif defined(__GNU__)
797 
798 #define i_translator	osd1.hurd1.h_i_translator
799 #define i_uid_high	osd2.hurd2.h_i_uid_high
800 #define i_gid_high	osd2.hurd2.h_i_gid_high
801 #define i_author	osd2.hurd2.h_i_author
802 
803 #elif defined(__masix__)
804 
805 #define i_reserved1	osd1.masix1.m_i_reserved1
806 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
807 #define i_reserved2	osd2.masix2.m_i_reserved2
808 
809 #endif /* defined(__KERNEL__) || defined(__linux__) */
810 
811 #include "extents_status.h"
812 
813 /*
814  * fourth extended file system inode data in memory
815  */
816 struct ext4_inode_info {
817 	__le32	i_data[15];	/* unconverted */
818 	__u32	i_dtime;
819 	ext4_fsblk_t	i_file_acl;
820 
821 	/*
822 	 * i_block_group is the number of the block group which contains
823 	 * this file's inode.  Constant across the lifetime of the inode,
824 	 * it is ued for making block allocation decisions - we try to
825 	 * place a file's data blocks near its inode block, and new inodes
826 	 * near to their parent directory's inode.
827 	 */
828 	ext4_group_t	i_block_group;
829 	ext4_lblk_t	i_dir_start_lookup;
830 #if (BITS_PER_LONG < 64)
831 	unsigned long	i_state_flags;		/* Dynamic state flags */
832 #endif
833 	unsigned long	i_flags;
834 
835 	/*
836 	 * Extended attributes can be read independently of the main file
837 	 * data. Taking i_mutex even when reading would cause contention
838 	 * between readers of EAs and writers of regular file data, so
839 	 * instead we synchronize on xattr_sem when reading or changing
840 	 * EAs.
841 	 */
842 	struct rw_semaphore xattr_sem;
843 
844 	struct list_head i_orphan;	/* unlinked but open inodes */
845 
846 	/*
847 	 * i_disksize keeps track of what the inode size is ON DISK, not
848 	 * in memory.  During truncate, i_size is set to the new size by
849 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
850 	 * set i_disksize to 0 until the truncate is actually under way.
851 	 *
852 	 * The intent is that i_disksize always represents the blocks which
853 	 * are used by this file.  This allows recovery to restart truncate
854 	 * on orphans if we crash during truncate.  We actually write i_disksize
855 	 * into the on-disk inode when writing inodes out, instead of i_size.
856 	 *
857 	 * The only time when i_disksize and i_size may be different is when
858 	 * a truncate is in progress.  The only things which change i_disksize
859 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
860 	 */
861 	loff_t	i_disksize;
862 
863 	/*
864 	 * i_data_sem is for serialising ext4_truncate() against
865 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
866 	 * data tree are chopped off during truncate. We can't do that in
867 	 * ext4 because whenever we perform intermediate commits during
868 	 * truncate, the inode and all the metadata blocks *must* be in a
869 	 * consistent state which allows truncation of the orphans to restart
870 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
871 	 * by other means, so we have i_data_sem.
872 	 */
873 	struct rw_semaphore i_data_sem;
874 	struct inode vfs_inode;
875 	struct jbd2_inode *jinode;
876 
877 	spinlock_t i_raw_lock;	/* protects updates to the raw inode */
878 
879 	/*
880 	 * File creation time. Its function is same as that of
881 	 * struct timespec i_{a,c,m}time in the generic inode.
882 	 */
883 	struct timespec i_crtime;
884 
885 	/* mballoc */
886 	struct list_head i_prealloc_list;
887 	spinlock_t i_prealloc_lock;
888 
889 	/* extents status tree */
890 	struct ext4_es_tree i_es_tree;
891 	rwlock_t i_es_lock;
892 	struct list_head i_es_lru;
893 	unsigned int i_es_lru_nr;	/* protected by i_es_lock */
894 	unsigned long i_touch_when;	/* jiffies of last accessing */
895 
896 	/* ialloc */
897 	ext4_group_t	i_last_alloc_group;
898 
899 	/* allocation reservation info for delalloc */
900 	/* In case of bigalloc, these refer to clusters rather than blocks */
901 	unsigned int i_reserved_data_blocks;
902 	unsigned int i_reserved_meta_blocks;
903 	unsigned int i_allocated_meta_blocks;
904 	ext4_lblk_t i_da_metadata_calc_last_lblock;
905 	int i_da_metadata_calc_len;
906 
907 	/* on-disk additional length */
908 	__u16 i_extra_isize;
909 
910 	/* Indicate the inline data space. */
911 	u16 i_inline_off;
912 	u16 i_inline_size;
913 
914 #ifdef CONFIG_QUOTA
915 	/* quota space reservation, managed internally by quota code */
916 	qsize_t i_reserved_quota;
917 #endif
918 
919 	/* Lock protecting lists below */
920 	spinlock_t i_completed_io_lock;
921 	/*
922 	 * Completed IOs that need unwritten extents handling and have
923 	 * transaction reserved
924 	 */
925 	struct list_head i_rsv_conversion_list;
926 	/*
927 	 * Completed IOs that need unwritten extents handling and don't have
928 	 * transaction reserved
929 	 */
930 	atomic_t i_ioend_count;	/* Number of outstanding io_end structs */
931 	atomic_t i_unwritten; /* Nr. of inflight conversions pending */
932 	struct work_struct i_rsv_conversion_work;
933 
934 	spinlock_t i_block_reservation_lock;
935 
936 	/*
937 	 * Transactions that contain inode's metadata needed to complete
938 	 * fsync and fdatasync, respectively.
939 	 */
940 	tid_t i_sync_tid;
941 	tid_t i_datasync_tid;
942 
943 	/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
944 	__u32 i_csum_seed;
945 };
946 
947 /*
948  * File system states
949  */
950 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
951 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
952 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
953 
954 /*
955  * Misc. filesystem flags
956  */
957 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
958 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
959 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
960 
961 /*
962  * Mount flags set via mount options or defaults
963  */
964 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
965 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
966 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
967 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
968 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
969 #define EXT4_MOUNT_ERRORS_MASK		0x00070
970 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
971 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
972 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
973 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
974 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
975 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
976 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
977 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
978 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
979 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
980 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
981 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
982 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
983 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
984 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
985 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
986 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
987 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
988 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
989 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
990 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
991 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
992 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
993 
994 /*
995  * Mount flags set either automatically (could not be set by mount option)
996  * based on per file system feature or property or in special cases such as
997  * distinguishing between explicit mount option definition and default.
998  */
999 #define EXT4_MOUNT2_EXPLICIT_DELALLOC	0x00000001 /* User explicitly
1000 						      specified delalloc */
1001 #define EXT4_MOUNT2_STD_GROUP_SIZE	0x00000002 /* We have standard group
1002 						      size of blocksize * 8
1003 						      blocks */
1004 #define EXT4_MOUNT2_HURD_COMPAT		0x00000004 /* Support HURD-castrated
1005 						      file systems */
1006 
1007 #define clear_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt &= \
1008 						~EXT4_MOUNT_##opt
1009 #define set_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt |= \
1010 						EXT4_MOUNT_##opt
1011 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
1012 					 EXT4_MOUNT_##opt)
1013 
1014 #define clear_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 &= \
1015 						~EXT4_MOUNT2_##opt
1016 #define set_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 |= \
1017 						EXT4_MOUNT2_##opt
1018 #define test_opt2(sb, opt)		(EXT4_SB(sb)->s_mount_opt2 & \
1019 					 EXT4_MOUNT2_##opt)
1020 
1021 #define ext4_test_and_set_bit		__test_and_set_bit_le
1022 #define ext4_set_bit			__set_bit_le
1023 #define ext4_set_bit_atomic		ext2_set_bit_atomic
1024 #define ext4_test_and_clear_bit		__test_and_clear_bit_le
1025 #define ext4_clear_bit			__clear_bit_le
1026 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
1027 #define ext4_test_bit			test_bit_le
1028 #define ext4_find_next_zero_bit		find_next_zero_bit_le
1029 #define ext4_find_next_bit		find_next_bit_le
1030 
1031 extern void ext4_set_bits(void *bm, int cur, int len);
1032 
1033 /*
1034  * Maximal mount counts between two filesystem checks
1035  */
1036 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
1037 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
1038 
1039 /*
1040  * Behaviour when detecting errors
1041  */
1042 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
1043 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
1044 #define EXT4_ERRORS_PANIC		3	/* Panic */
1045 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
1046 
1047 /* Metadata checksum algorithm codes */
1048 #define EXT4_CRC32C_CHKSUM		1
1049 
1050 /*
1051  * Structure of the super block
1052  */
1053 struct ext4_super_block {
1054 /*00*/	__le32	s_inodes_count;		/* Inodes count */
1055 	__le32	s_blocks_count_lo;	/* Blocks count */
1056 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
1057 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
1058 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
1059 	__le32	s_first_data_block;	/* First Data Block */
1060 	__le32	s_log_block_size;	/* Block size */
1061 	__le32	s_log_cluster_size;	/* Allocation cluster size */
1062 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
1063 	__le32	s_clusters_per_group;	/* # Clusters per group */
1064 	__le32	s_inodes_per_group;	/* # Inodes per group */
1065 	__le32	s_mtime;		/* Mount time */
1066 /*30*/	__le32	s_wtime;		/* Write time */
1067 	__le16	s_mnt_count;		/* Mount count */
1068 	__le16	s_max_mnt_count;	/* Maximal mount count */
1069 	__le16	s_magic;		/* Magic signature */
1070 	__le16	s_state;		/* File system state */
1071 	__le16	s_errors;		/* Behaviour when detecting errors */
1072 	__le16	s_minor_rev_level;	/* minor revision level */
1073 /*40*/	__le32	s_lastcheck;		/* time of last check */
1074 	__le32	s_checkinterval;	/* max. time between checks */
1075 	__le32	s_creator_os;		/* OS */
1076 	__le32	s_rev_level;		/* Revision level */
1077 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
1078 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
1079 	/*
1080 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
1081 	 *
1082 	 * Note: the difference between the compatible feature set and
1083 	 * the incompatible feature set is that if there is a bit set
1084 	 * in the incompatible feature set that the kernel doesn't
1085 	 * know about, it should refuse to mount the filesystem.
1086 	 *
1087 	 * e2fsck's requirements are more strict; if it doesn't know
1088 	 * about a feature in either the compatible or incompatible
1089 	 * feature set, it must abort and not try to meddle with
1090 	 * things it doesn't understand...
1091 	 */
1092 	__le32	s_first_ino;		/* First non-reserved inode */
1093 	__le16  s_inode_size;		/* size of inode structure */
1094 	__le16	s_block_group_nr;	/* block group # of this superblock */
1095 	__le32	s_feature_compat;	/* compatible feature set */
1096 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
1097 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
1098 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
1099 /*78*/	char	s_volume_name[16];	/* volume name */
1100 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
1101 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
1102 	/*
1103 	 * Performance hints.  Directory preallocation should only
1104 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1105 	 */
1106 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
1107 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
1108 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
1109 	/*
1110 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1111 	 */
1112 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
1113 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
1114 	__le32	s_journal_dev;		/* device number of journal file */
1115 	__le32	s_last_orphan;		/* start of list of inodes to delete */
1116 	__le32	s_hash_seed[4];		/* HTREE hash seed */
1117 	__u8	s_def_hash_version;	/* Default hash version to use */
1118 	__u8	s_jnl_backup_type;
1119 	__le16  s_desc_size;		/* size of group descriptor */
1120 /*100*/	__le32	s_default_mount_opts;
1121 	__le32	s_first_meta_bg;	/* First metablock block group */
1122 	__le32	s_mkfs_time;		/* When the filesystem was created */
1123 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
1124 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1125 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
1126 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
1127 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
1128 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
1129 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
1130 	__le32	s_flags;		/* Miscellaneous flags */
1131 	__le16  s_raid_stride;		/* RAID stride */
1132 	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1133 	__le64  s_mmp_block;            /* Block for multi-mount protection */
1134 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1135 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
1136 	__u8	s_checksum_type;	/* metadata checksum algorithm used */
1137 	__le16  s_reserved_pad;
1138 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1139 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
1140 	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
1141 	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
1142 					      snapshot's future use */
1143 	__le32	s_snapshot_list;	/* inode number of the head of the
1144 					   on-disk snapshot list */
1145 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1146 	__le32	s_error_count;		/* number of fs errors */
1147 	__le32	s_first_error_time;	/* first time an error happened */
1148 	__le32	s_first_error_ino;	/* inode involved in first error */
1149 	__le64	s_first_error_block;	/* block involved of first error */
1150 	__u8	s_first_error_func[32];	/* function where the error happened */
1151 	__le32	s_first_error_line;	/* line number where error happened */
1152 	__le32	s_last_error_time;	/* most recent time of an error */
1153 	__le32	s_last_error_ino;	/* inode involved in last error */
1154 	__le32	s_last_error_line;	/* line number where error happened */
1155 	__le64	s_last_error_block;	/* block involved of last error */
1156 	__u8	s_last_error_func[32];	/* function where the error happened */
1157 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1158 	__u8	s_mount_opts[64];
1159 	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
1160 	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
1161 	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
1162 	__le32	s_backup_bgs[2];	/* groups with sparse_super2 SBs */
1163 	__le32	s_reserved[106];	/* Padding to the end of the block */
1164 	__le32	s_checksum;		/* crc32c(superblock) */
1165 };
1166 
1167 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1168 
1169 #ifdef __KERNEL__
1170 
1171 /*
1172  * run-time mount flags
1173  */
1174 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
1175 #define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
1176 
1177 /*
1178  * fourth extended-fs super-block data in memory
1179  */
1180 struct ext4_sb_info {
1181 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
1182 	unsigned long s_inodes_per_block;/* Number of inodes per block */
1183 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
1184 	unsigned long s_clusters_per_group; /* Number of clusters in a group */
1185 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
1186 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
1187 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
1188 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
1189 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1190 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1191 	unsigned long s_overhead;  /* # of fs overhead clusters */
1192 	unsigned int s_cluster_ratio;	/* Number of blocks per cluster */
1193 	unsigned int s_cluster_bits;	/* log2 of s_cluster_ratio */
1194 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
1195 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
1196 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
1197 	struct buffer_head **s_group_desc;
1198 	unsigned int s_mount_opt;
1199 	unsigned int s_mount_opt2;
1200 	unsigned int s_mount_flags;
1201 	unsigned int s_def_mount_opt;
1202 	ext4_fsblk_t s_sb_block;
1203 	atomic64_t s_resv_clusters;
1204 	kuid_t s_resuid;
1205 	kgid_t s_resgid;
1206 	unsigned short s_mount_state;
1207 	unsigned short s_pad;
1208 	int s_addr_per_block_bits;
1209 	int s_desc_per_block_bits;
1210 	int s_inode_size;
1211 	int s_first_ino;
1212 	unsigned int s_inode_readahead_blks;
1213 	unsigned int s_inode_goal;
1214 	spinlock_t s_next_gen_lock;
1215 	u32 s_next_generation;
1216 	u32 s_hash_seed[4];
1217 	int s_def_hash_version;
1218 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
1219 	struct percpu_counter s_freeclusters_counter;
1220 	struct percpu_counter s_freeinodes_counter;
1221 	struct percpu_counter s_dirs_counter;
1222 	struct percpu_counter s_dirtyclusters_counter;
1223 	struct blockgroup_lock *s_blockgroup_lock;
1224 	struct proc_dir_entry *s_proc;
1225 	struct kobject s_kobj;
1226 	struct completion s_kobj_unregister;
1227 	struct super_block *s_sb;
1228 
1229 	/* Journaling */
1230 	struct journal_s *s_journal;
1231 	struct list_head s_orphan;
1232 	struct mutex s_orphan_lock;
1233 	unsigned long s_resize_flags;		/* Flags indicating if there
1234 						   is a resizer */
1235 	unsigned long s_commit_interval;
1236 	u32 s_max_batch_time;
1237 	u32 s_min_batch_time;
1238 	struct block_device *journal_bdev;
1239 #ifdef CONFIG_QUOTA
1240 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
1241 	int s_jquota_fmt;			/* Format of quota to use */
1242 #endif
1243 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1244 	struct rb_root system_blks;
1245 
1246 #ifdef EXTENTS_STATS
1247 	/* ext4 extents stats */
1248 	unsigned long s_ext_min;
1249 	unsigned long s_ext_max;
1250 	unsigned long s_depth_max;
1251 	spinlock_t s_ext_stats_lock;
1252 	unsigned long s_ext_blocks;
1253 	unsigned long s_ext_extents;
1254 #endif
1255 
1256 	/* for buddy allocator */
1257 	struct ext4_group_info ***s_group_info;
1258 	struct inode *s_buddy_cache;
1259 	spinlock_t s_md_lock;
1260 	unsigned short *s_mb_offsets;
1261 	unsigned int *s_mb_maxs;
1262 	unsigned int s_group_info_size;
1263 
1264 	/* tunables */
1265 	unsigned long s_stripe;
1266 	unsigned int s_mb_stream_request;
1267 	unsigned int s_mb_max_to_scan;
1268 	unsigned int s_mb_min_to_scan;
1269 	unsigned int s_mb_stats;
1270 	unsigned int s_mb_order2_reqs;
1271 	unsigned int s_mb_group_prealloc;
1272 	unsigned int s_max_dir_size_kb;
1273 	/* where last allocation was done - for stream allocation */
1274 	unsigned long s_mb_last_group;
1275 	unsigned long s_mb_last_start;
1276 
1277 	/* stats for buddy allocator */
1278 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1279 	atomic_t s_bal_success;	/* we found long enough chunks */
1280 	atomic_t s_bal_allocated;	/* in blocks */
1281 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1282 	atomic_t s_bal_goals;	/* goal hits */
1283 	atomic_t s_bal_breaks;	/* too long searches */
1284 	atomic_t s_bal_2orders;	/* 2^order hits */
1285 	spinlock_t s_bal_lock;
1286 	unsigned long s_mb_buddies_generated;
1287 	unsigned long long s_mb_generation_time;
1288 	atomic_t s_mb_lost_chunks;
1289 	atomic_t s_mb_preallocated;
1290 	atomic_t s_mb_discarded;
1291 	atomic_t s_lock_busy;
1292 
1293 	/* locality groups */
1294 	struct ext4_locality_group __percpu *s_locality_groups;
1295 
1296 	/* for write statistics */
1297 	unsigned long s_sectors_written_start;
1298 	u64 s_kbytes_written;
1299 
1300 	/* the size of zero-out chunk */
1301 	unsigned int s_extent_max_zeroout_kb;
1302 
1303 	unsigned int s_log_groups_per_flex;
1304 	struct flex_groups *s_flex_groups;
1305 	ext4_group_t s_flex_groups_allocated;
1306 
1307 	/* workqueue for reserved extent conversions (buffered io) */
1308 	struct workqueue_struct *rsv_conversion_wq;
1309 
1310 	/* timer for periodic error stats printing */
1311 	struct timer_list s_err_report;
1312 
1313 	/* Lazy inode table initialization info */
1314 	struct ext4_li_request *s_li_request;
1315 	/* Wait multiplier for lazy initialization thread */
1316 	unsigned int s_li_wait_mult;
1317 
1318 	/* Kernel thread for multiple mount protection */
1319 	struct task_struct *s_mmp_tsk;
1320 
1321 	/* record the last minlen when FITRIM is called. */
1322 	atomic_t s_last_trim_minblks;
1323 
1324 	/* Reference to checksum algorithm driver via cryptoapi */
1325 	struct crypto_shash *s_chksum_driver;
1326 
1327 	/* Precomputed FS UUID checksum for seeding other checksums */
1328 	__u32 s_csum_seed;
1329 
1330 	/* Reclaim extents from extent status tree */
1331 	struct shrinker s_es_shrinker;
1332 	struct list_head s_es_lru;
1333 	unsigned long s_es_last_sorted;
1334 	struct percpu_counter s_extent_cache_cnt;
1335 	struct mb_cache *s_mb_cache;
1336 	spinlock_t s_es_lru_lock ____cacheline_aligned_in_smp;
1337 
1338 	/* Ratelimit ext4 messages. */
1339 	struct ratelimit_state s_err_ratelimit_state;
1340 	struct ratelimit_state s_warning_ratelimit_state;
1341 	struct ratelimit_state s_msg_ratelimit_state;
1342 };
1343 
1344 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1345 {
1346 	return sb->s_fs_info;
1347 }
1348 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1349 {
1350 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1351 }
1352 
1353 static inline struct timespec ext4_current_time(struct inode *inode)
1354 {
1355 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1356 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1357 }
1358 
1359 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1360 {
1361 	return ino == EXT4_ROOT_INO ||
1362 		ino == EXT4_USR_QUOTA_INO ||
1363 		ino == EXT4_GRP_QUOTA_INO ||
1364 		ino == EXT4_BOOT_LOADER_INO ||
1365 		ino == EXT4_JOURNAL_INO ||
1366 		ino == EXT4_RESIZE_INO ||
1367 		(ino >= EXT4_FIRST_INO(sb) &&
1368 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1369 }
1370 
1371 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1372 					      struct ext4_io_end *io_end)
1373 {
1374 	if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1375 		io_end->flag |= EXT4_IO_END_UNWRITTEN;
1376 		atomic_inc(&EXT4_I(inode)->i_unwritten);
1377 	}
1378 }
1379 
1380 static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode)
1381 {
1382 	return inode->i_private;
1383 }
1384 
1385 static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io)
1386 {
1387 	inode->i_private = io;
1388 }
1389 
1390 /*
1391  * Inode dynamic state flags
1392  */
1393 enum {
1394 	EXT4_STATE_JDATA,		/* journaled data exists */
1395 	EXT4_STATE_NEW,			/* inode is newly created */
1396 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1397 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1398 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1399 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1400 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1401 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1402 	EXT4_STATE_DELALLOC_RESERVED,	/* blks already reserved for delalloc */
1403 	EXT4_STATE_DIOREAD_LOCK,	/* Disable support for dio read
1404 					   nolocking */
1405 	EXT4_STATE_MAY_INLINE_DATA,	/* may have in-inode data */
1406 	EXT4_STATE_ORDERED_MODE,	/* data=ordered mode */
1407 	EXT4_STATE_EXT_PRECACHED,	/* extents have been precached */
1408 };
1409 
1410 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
1411 static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
1412 {									\
1413 	return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);	\
1414 }									\
1415 static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
1416 {									\
1417 	set_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1418 }									\
1419 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1420 {									\
1421 	clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1422 }
1423 
1424 /* Add these declarations here only so that these functions can be
1425  * found by name.  Otherwise, they are very hard to locate. */
1426 static inline int ext4_test_inode_flag(struct inode *inode, int bit);
1427 static inline void ext4_set_inode_flag(struct inode *inode, int bit);
1428 static inline void ext4_clear_inode_flag(struct inode *inode, int bit);
1429 EXT4_INODE_BIT_FNS(flag, flags, 0)
1430 
1431 /* Add these declarations here only so that these functions can be
1432  * found by name.  Otherwise, they are very hard to locate. */
1433 static inline int ext4_test_inode_state(struct inode *inode, int bit);
1434 static inline void ext4_set_inode_state(struct inode *inode, int bit);
1435 static inline void ext4_clear_inode_state(struct inode *inode, int bit);
1436 #if (BITS_PER_LONG < 64)
1437 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1438 
1439 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1440 {
1441 	(ei)->i_state_flags = 0;
1442 }
1443 #else
1444 EXT4_INODE_BIT_FNS(state, flags, 32)
1445 
1446 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1447 {
1448 	/* We depend on the fact that callers will set i_flags */
1449 }
1450 #endif
1451 #else
1452 /* Assume that user mode programs are passing in an ext4fs superblock, not
1453  * a kernel struct super_block.  This will allow us to call the feature-test
1454  * macros from user land. */
1455 #define EXT4_SB(sb)	(sb)
1456 #endif
1457 
1458 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1459 
1460 /*
1461  * Codes for operating systems
1462  */
1463 #define EXT4_OS_LINUX		0
1464 #define EXT4_OS_HURD		1
1465 #define EXT4_OS_MASIX		2
1466 #define EXT4_OS_FREEBSD		3
1467 #define EXT4_OS_LITES		4
1468 
1469 /*
1470  * Revision levels
1471  */
1472 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1473 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1474 
1475 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1476 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1477 
1478 #define EXT4_GOOD_OLD_INODE_SIZE 128
1479 
1480 /*
1481  * Feature set definitions
1482  */
1483 
1484 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1485 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1486 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1487 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1488 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1489 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1490 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1491 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1492 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1493 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1494 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1495 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1496 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1497 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1498 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1499 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1500 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1501 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1502 
1503 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1504 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1505 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1506 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1507 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1508 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1509 #define EXT4_FEATURE_COMPAT_SPARSE_SUPER2	0x0200
1510 
1511 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1512 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1513 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1514 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1515 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1516 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1517 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1518 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
1519 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
1520 /*
1521  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1522  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1523  * all other data structures' checksums.  However, the METADATA_CSUM and
1524  * GDT_CSUM bits are mutually exclusive.
1525  */
1526 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
1527 
1528 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1529 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1530 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1531 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1532 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1533 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1534 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1535 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1536 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1537 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1538 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1539 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM	0x2000 /* use crc32c for bg */
1540 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
1541 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA	0x8000 /* data in inode */
1542 
1543 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1544 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1545 					 EXT4_FEATURE_INCOMPAT_META_BG)
1546 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1547 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1548 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1549 
1550 #define EXT3_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1551 #define EXT3_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1552 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1553 					 EXT4_FEATURE_INCOMPAT_META_BG)
1554 #define EXT3_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1555 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1556 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1557 
1558 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1559 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1560 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1561 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1562 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1563 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1564 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1565 					 EXT4_FEATURE_INCOMPAT_MMP |	\
1566 					 EXT4_FEATURE_INCOMPAT_INLINE_DATA)
1567 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1568 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1569 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1570 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1571 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1572 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1573 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1574 					 EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1575 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1576 					 EXT4_FEATURE_RO_COMPAT_QUOTA)
1577 
1578 /*
1579  * Default values for user and/or group using reserved blocks
1580  */
1581 #define	EXT4_DEF_RESUID		0
1582 #define	EXT4_DEF_RESGID		0
1583 
1584 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1585 
1586 /*
1587  * Default mount options
1588  */
1589 #define EXT4_DEFM_DEBUG		0x0001
1590 #define EXT4_DEFM_BSDGROUPS	0x0002
1591 #define EXT4_DEFM_XATTR_USER	0x0004
1592 #define EXT4_DEFM_ACL		0x0008
1593 #define EXT4_DEFM_UID16		0x0010
1594 #define EXT4_DEFM_JMODE		0x0060
1595 #define EXT4_DEFM_JMODE_DATA	0x0020
1596 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1597 #define EXT4_DEFM_JMODE_WBACK	0x0060
1598 #define EXT4_DEFM_NOBARRIER	0x0100
1599 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1600 #define EXT4_DEFM_DISCARD	0x0400
1601 #define EXT4_DEFM_NODELALLOC	0x0800
1602 
1603 /*
1604  * Default journal batch times
1605  */
1606 #define EXT4_DEF_MIN_BATCH_TIME	0
1607 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1608 
1609 /*
1610  * Minimum number of groups in a flexgroup before we separate out
1611  * directories into the first block group of a flexgroup
1612  */
1613 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1614 
1615 /*
1616  * Structure of a directory entry
1617  */
1618 #define EXT4_NAME_LEN 255
1619 
1620 struct ext4_dir_entry {
1621 	__le32	inode;			/* Inode number */
1622 	__le16	rec_len;		/* Directory entry length */
1623 	__le16	name_len;		/* Name length */
1624 	char	name[EXT4_NAME_LEN];	/* File name */
1625 };
1626 
1627 /*
1628  * The new version of the directory entry.  Since EXT4 structures are
1629  * stored in intel byte order, and the name_len field could never be
1630  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1631  * file_type field.
1632  */
1633 struct ext4_dir_entry_2 {
1634 	__le32	inode;			/* Inode number */
1635 	__le16	rec_len;		/* Directory entry length */
1636 	__u8	name_len;		/* Name length */
1637 	__u8	file_type;
1638 	char	name[EXT4_NAME_LEN];	/* File name */
1639 };
1640 
1641 /*
1642  * This is a bogus directory entry at the end of each leaf block that
1643  * records checksums.
1644  */
1645 struct ext4_dir_entry_tail {
1646 	__le32	det_reserved_zero1;	/* Pretend to be unused */
1647 	__le16	det_rec_len;		/* 12 */
1648 	__u8	det_reserved_zero2;	/* Zero name length */
1649 	__u8	det_reserved_ft;	/* 0xDE, fake file type */
1650 	__le32	det_checksum;		/* crc32c(uuid+inum+dirblock) */
1651 };
1652 
1653 #define EXT4_DIRENT_TAIL(block, blocksize) \
1654 	((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1655 					((blocksize) - \
1656 					 sizeof(struct ext4_dir_entry_tail))))
1657 
1658 /*
1659  * Ext4 directory file types.  Only the low 3 bits are used.  The
1660  * other bits are reserved for now.
1661  */
1662 #define EXT4_FT_UNKNOWN		0
1663 #define EXT4_FT_REG_FILE	1
1664 #define EXT4_FT_DIR		2
1665 #define EXT4_FT_CHRDEV		3
1666 #define EXT4_FT_BLKDEV		4
1667 #define EXT4_FT_FIFO		5
1668 #define EXT4_FT_SOCK		6
1669 #define EXT4_FT_SYMLINK		7
1670 
1671 #define EXT4_FT_MAX		8
1672 
1673 #define EXT4_FT_DIR_CSUM	0xDE
1674 
1675 /*
1676  * EXT4_DIR_PAD defines the directory entries boundaries
1677  *
1678  * NOTE: It must be a multiple of 4
1679  */
1680 #define EXT4_DIR_PAD			4
1681 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1682 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1683 					 ~EXT4_DIR_ROUND)
1684 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1685 
1686 /*
1687  * If we ever get support for fs block sizes > page_size, we'll need
1688  * to remove the #if statements in the next two functions...
1689  */
1690 static inline unsigned int
1691 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1692 {
1693 	unsigned len = le16_to_cpu(dlen);
1694 
1695 #if (PAGE_CACHE_SIZE >= 65536)
1696 	if (len == EXT4_MAX_REC_LEN || len == 0)
1697 		return blocksize;
1698 	return (len & 65532) | ((len & 3) << 16);
1699 #else
1700 	return len;
1701 #endif
1702 }
1703 
1704 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1705 {
1706 	if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1707 		BUG();
1708 #if (PAGE_CACHE_SIZE >= 65536)
1709 	if (len < 65536)
1710 		return cpu_to_le16(len);
1711 	if (len == blocksize) {
1712 		if (blocksize == 65536)
1713 			return cpu_to_le16(EXT4_MAX_REC_LEN);
1714 		else
1715 			return cpu_to_le16(0);
1716 	}
1717 	return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1718 #else
1719 	return cpu_to_le16(len);
1720 #endif
1721 }
1722 
1723 /*
1724  * Hash Tree Directory indexing
1725  * (c) Daniel Phillips, 2001
1726  */
1727 
1728 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1729 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1730 		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1731 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1732 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1733 
1734 /* Legal values for the dx_root hash_version field: */
1735 
1736 #define DX_HASH_LEGACY		0
1737 #define DX_HASH_HALF_MD4	1
1738 #define DX_HASH_TEA		2
1739 #define DX_HASH_LEGACY_UNSIGNED	3
1740 #define DX_HASH_HALF_MD4_UNSIGNED	4
1741 #define DX_HASH_TEA_UNSIGNED		5
1742 
1743 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1744 			      const void *address, unsigned int length)
1745 {
1746 	struct {
1747 		struct shash_desc shash;
1748 		char ctx[4];
1749 	} desc;
1750 	int err;
1751 
1752 	BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
1753 
1754 	desc.shash.tfm = sbi->s_chksum_driver;
1755 	desc.shash.flags = 0;
1756 	*(u32 *)desc.ctx = crc;
1757 
1758 	err = crypto_shash_update(&desc.shash, address, length);
1759 	BUG_ON(err);
1760 
1761 	return *(u32 *)desc.ctx;
1762 }
1763 
1764 #ifdef __KERNEL__
1765 
1766 /* hash info structure used by the directory hash */
1767 struct dx_hash_info
1768 {
1769 	u32		hash;
1770 	u32		minor_hash;
1771 	int		hash_version;
1772 	u32		*seed;
1773 };
1774 
1775 
1776 /* 32 and 64 bit signed EOF for dx directories */
1777 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
1778 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
1779 
1780 
1781 /*
1782  * Control parameters used by ext4_htree_next_block
1783  */
1784 #define HASH_NB_ALWAYS		1
1785 
1786 
1787 /*
1788  * Describe an inode's exact location on disk and in memory
1789  */
1790 struct ext4_iloc
1791 {
1792 	struct buffer_head *bh;
1793 	unsigned long offset;
1794 	ext4_group_t block_group;
1795 };
1796 
1797 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1798 {
1799 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1800 }
1801 
1802 /*
1803  * This structure is stuffed into the struct file's private_data field
1804  * for directories.  It is where we put information so that we can do
1805  * readdir operations in hash tree order.
1806  */
1807 struct dir_private_info {
1808 	struct rb_root	root;
1809 	struct rb_node	*curr_node;
1810 	struct fname	*extra_fname;
1811 	loff_t		last_pos;
1812 	__u32		curr_hash;
1813 	__u32		curr_minor_hash;
1814 	__u32		next_hash;
1815 };
1816 
1817 /* calculate the first block number of the group */
1818 static inline ext4_fsblk_t
1819 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1820 {
1821 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1822 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1823 }
1824 
1825 /*
1826  * Special error return code only used by dx_probe() and its callers.
1827  */
1828 #define ERR_BAD_DX_DIR	-75000
1829 
1830 /*
1831  * Timeout and state flag for lazy initialization inode thread.
1832  */
1833 #define EXT4_DEF_LI_WAIT_MULT			10
1834 #define EXT4_DEF_LI_MAX_START_DELAY		5
1835 #define EXT4_LAZYINIT_QUIT			0x0001
1836 #define EXT4_LAZYINIT_RUNNING			0x0002
1837 
1838 /*
1839  * Lazy inode table initialization info
1840  */
1841 struct ext4_lazy_init {
1842 	unsigned long		li_state;
1843 	struct list_head	li_request_list;
1844 	struct mutex		li_list_mtx;
1845 };
1846 
1847 struct ext4_li_request {
1848 	struct super_block	*lr_super;
1849 	struct ext4_sb_info	*lr_sbi;
1850 	ext4_group_t		lr_next_group;
1851 	struct list_head	lr_request;
1852 	unsigned long		lr_next_sched;
1853 	unsigned long		lr_timeout;
1854 };
1855 
1856 struct ext4_features {
1857 	struct kobject f_kobj;
1858 	struct completion f_kobj_unregister;
1859 };
1860 
1861 /*
1862  * This structure will be used for multiple mount protection. It will be
1863  * written into the block number saved in the s_mmp_block field in the
1864  * superblock. Programs that check MMP should assume that if
1865  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1866  * to use the filesystem, regardless of how old the timestamp is.
1867  */
1868 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1869 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1870 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1871 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1872 
1873 struct mmp_struct {
1874 	__le32	mmp_magic;		/* Magic number for MMP */
1875 	__le32	mmp_seq;		/* Sequence no. updated periodically */
1876 
1877 	/*
1878 	 * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1879 	 * purposes and do not affect the correctness of the algorithm
1880 	 */
1881 	__le64	mmp_time;		/* Time last updated */
1882 	char	mmp_nodename[64];	/* Node which last updated MMP block */
1883 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
1884 
1885 	/*
1886 	 * mmp_check_interval is used to verify if the MMP block has been
1887 	 * updated on the block device. The value is updated based on the
1888 	 * maximum time to write the MMP block during an update cycle.
1889 	 */
1890 	__le16	mmp_check_interval;
1891 
1892 	__le16	mmp_pad1;
1893 	__le32	mmp_pad2[226];
1894 	__le32	mmp_checksum;		/* crc32c(uuid+mmp_block) */
1895 };
1896 
1897 /* arguments passed to the mmp thread */
1898 struct mmpd_data {
1899 	struct buffer_head *bh; /* bh from initial read_mmp_block() */
1900 	struct super_block *sb;  /* super block of the fs */
1901 };
1902 
1903 /*
1904  * Check interval multiplier
1905  * The MMP block is written every update interval and initially checked every
1906  * update interval x the multiplier (the value is then adapted based on the
1907  * write latency). The reason is that writes can be delayed under load and we
1908  * don't want readers to incorrectly assume that the filesystem is no longer
1909  * in use.
1910  */
1911 #define EXT4_MMP_CHECK_MULT		2UL
1912 
1913 /*
1914  * Minimum interval for MMP checking in seconds.
1915  */
1916 #define EXT4_MMP_MIN_CHECK_INTERVAL	5UL
1917 
1918 /*
1919  * Maximum interval for MMP checking in seconds.
1920  */
1921 #define EXT4_MMP_MAX_CHECK_INTERVAL	300UL
1922 
1923 /*
1924  * Function prototypes
1925  */
1926 
1927 /*
1928  * Ok, these declarations are also in <linux/kernel.h> but none of the
1929  * ext4 source programs needs to include it so they are duplicated here.
1930  */
1931 # define NORET_TYPE	/**/
1932 # define ATTRIB_NORET	__attribute__((noreturn))
1933 # define NORET_AND	noreturn,
1934 
1935 /* bitmap.c */
1936 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
1937 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1938 				struct ext4_group_desc *gdp,
1939 				struct buffer_head *bh, int sz);
1940 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1941 				  struct ext4_group_desc *gdp,
1942 				  struct buffer_head *bh, int sz);
1943 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1944 				struct ext4_group_desc *gdp,
1945 				struct buffer_head *bh);
1946 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1947 				  struct ext4_group_desc *gdp,
1948 				  struct buffer_head *bh);
1949 
1950 /* balloc.c */
1951 extern void ext4_get_group_no_and_offset(struct super_block *sb,
1952 					 ext4_fsblk_t blocknr,
1953 					 ext4_group_t *blockgrpp,
1954 					 ext4_grpblk_t *offsetp);
1955 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
1956 					  ext4_fsblk_t block);
1957 
1958 extern unsigned int ext4_block_group(struct super_block *sb,
1959 			ext4_fsblk_t blocknr);
1960 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1961 			ext4_fsblk_t blocknr);
1962 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1963 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1964 			ext4_group_t group);
1965 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1966 					 ext4_fsblk_t goal,
1967 					 unsigned int flags,
1968 					 unsigned long *count,
1969 					 int *errp);
1970 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1971 				    s64 nclusters, unsigned int flags);
1972 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1973 extern void ext4_check_blocks_bitmap(struct super_block *);
1974 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1975 						    ext4_group_t block_group,
1976 						    struct buffer_head ** bh);
1977 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1978 
1979 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1980 						ext4_group_t block_group);
1981 extern int ext4_wait_block_bitmap(struct super_block *sb,
1982 				  ext4_group_t block_group,
1983 				  struct buffer_head *bh);
1984 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1985 						  ext4_group_t block_group);
1986 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1987 					      ext4_group_t block_group,
1988 					      struct ext4_group_desc *gdp);
1989 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1990 
1991 /* dir.c */
1992 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1993 				  struct file *,
1994 				  struct ext4_dir_entry_2 *,
1995 				  struct buffer_head *, char *, int,
1996 				  unsigned int);
1997 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)	\
1998 	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1999 					(de), (bh), (buf), (size), (offset)))
2000 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
2001 				    __u32 minor_hash,
2002 				    struct ext4_dir_entry_2 *dirent);
2003 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
2004 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
2005 			     struct buffer_head *bh,
2006 			     void *buf, int buf_size,
2007 			     const char *name, int namelen,
2008 			     struct ext4_dir_entry_2 **dest_de);
2009 void ext4_insert_dentry(struct inode *inode,
2010 			struct ext4_dir_entry_2 *de,
2011 			int buf_size,
2012 			const char *name, int namelen);
2013 static inline void ext4_update_dx_flag(struct inode *inode)
2014 {
2015 	if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
2016 				     EXT4_FEATURE_COMPAT_DIR_INDEX))
2017 		ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
2018 }
2019 static unsigned char ext4_filetype_table[] = {
2020 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
2021 };
2022 
2023 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
2024 {
2025 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
2026 	    (filetype >= EXT4_FT_MAX))
2027 		return DT_UNKNOWN;
2028 
2029 	return ext4_filetype_table[filetype];
2030 }
2031 extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
2032 			     void *buf, int buf_size);
2033 
2034 /* fsync.c */
2035 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2036 
2037 /* hash.c */
2038 extern int ext4fs_dirhash(const char *name, int len, struct
2039 			  dx_hash_info *hinfo);
2040 
2041 /* ialloc.c */
2042 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
2043 				      const struct qstr *qstr, __u32 goal,
2044 				      uid_t *owner, int handle_type,
2045 				      unsigned int line_no, int nblocks);
2046 
2047 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner) \
2048 	__ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
2049 			 0, 0, 0)
2050 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
2051 				    type, nblocks)		    \
2052 	__ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
2053 			 (type), __LINE__, (nblocks))
2054 
2055 
2056 extern void ext4_free_inode(handle_t *, struct inode *);
2057 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2058 extern unsigned long ext4_count_free_inodes(struct super_block *);
2059 extern unsigned long ext4_count_dirs(struct super_block *);
2060 extern void ext4_check_inodes_bitmap(struct super_block *);
2061 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2062 extern int ext4_init_inode_table(struct super_block *sb,
2063 				 ext4_group_t group, int barrier);
2064 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2065 
2066 /* mballoc.c */
2067 extern long ext4_mb_stats;
2068 extern long ext4_mb_max_to_scan;
2069 extern int ext4_mb_init(struct super_block *);
2070 extern int ext4_mb_release(struct super_block *);
2071 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2072 				struct ext4_allocation_request *, int *);
2073 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2074 extern void ext4_discard_preallocations(struct inode *);
2075 extern int __init ext4_init_mballoc(void);
2076 extern void ext4_exit_mballoc(void);
2077 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2078 			     struct buffer_head *bh, ext4_fsblk_t block,
2079 			     unsigned long count, int flags);
2080 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2081 				   ext4_group_t ngroups);
2082 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2083 		ext4_group_t i, struct ext4_group_desc *desc);
2084 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2085 				ext4_fsblk_t block, unsigned long count);
2086 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2087 
2088 /* inode.c */
2089 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
2090 						ext4_lblk_t, int, int *);
2091 struct buffer_head *ext4_bread(handle_t *, struct inode *,
2092 						ext4_lblk_t, int, int *);
2093 int ext4_get_block_write(struct inode *inode, sector_t iblock,
2094 			 struct buffer_head *bh_result, int create);
2095 int ext4_get_block(struct inode *inode, sector_t iblock,
2096 				struct buffer_head *bh_result, int create);
2097 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2098 			   struct buffer_head *bh, int create);
2099 int ext4_walk_page_buffers(handle_t *handle,
2100 			   struct buffer_head *head,
2101 			   unsigned from,
2102 			   unsigned to,
2103 			   int *partial,
2104 			   int (*fn)(handle_t *handle,
2105 				     struct buffer_head *bh));
2106 int do_journal_get_write_access(handle_t *handle,
2107 				struct buffer_head *bh);
2108 #define FALL_BACK_TO_NONDELALLOC 1
2109 #define CONVERT_INLINE_DATA	 2
2110 
2111 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2112 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2113 extern int  ext4_setattr(struct dentry *, struct iattr *);
2114 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
2115 				struct kstat *stat);
2116 extern void ext4_evict_inode(struct inode *);
2117 extern void ext4_clear_inode(struct inode *);
2118 extern int  ext4_sync_inode(handle_t *, struct inode *);
2119 extern void ext4_dirty_inode(struct inode *, int);
2120 extern int ext4_change_inode_journal_flag(struct inode *, int);
2121 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2122 extern int ext4_inode_attach_jinode(struct inode *inode);
2123 extern int ext4_can_truncate(struct inode *inode);
2124 extern void ext4_truncate(struct inode *);
2125 extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length);
2126 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2127 extern void ext4_set_inode_flags(struct inode *);
2128 extern void ext4_get_inode_flags(struct ext4_inode_info *);
2129 extern int ext4_alloc_da_blocks(struct inode *inode);
2130 extern void ext4_set_aops(struct inode *inode);
2131 extern int ext4_writepage_trans_blocks(struct inode *);
2132 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2133 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
2134 			     loff_t lstart, loff_t lend);
2135 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2136 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2137 extern void ext4_da_update_reserve_space(struct inode *inode,
2138 					int used, int quota_claim);
2139 
2140 /* indirect.c */
2141 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2142 				struct ext4_map_blocks *map, int flags);
2143 extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
2144 				struct iov_iter *iter, loff_t offset);
2145 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2146 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2147 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2148 extern int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
2149 				 ext4_lblk_t start, ext4_lblk_t end);
2150 
2151 /* ioctl.c */
2152 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2153 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2154 
2155 /* migrate.c */
2156 extern int ext4_ext_migrate(struct inode *);
2157 extern int ext4_ind_migrate(struct inode *inode);
2158 
2159 /* namei.c */
2160 extern int ext4_dirent_csum_verify(struct inode *inode,
2161 				   struct ext4_dir_entry *dirent);
2162 extern int ext4_orphan_add(handle_t *, struct inode *);
2163 extern int ext4_orphan_del(handle_t *, struct inode *);
2164 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2165 				__u32 start_minor_hash, __u32 *next_hash);
2166 extern int search_dir(struct buffer_head *bh,
2167 		      char *search_buf,
2168 		      int buf_size,
2169 		      struct inode *dir,
2170 		      const struct qstr *d_name,
2171 		      unsigned int offset,
2172 		      struct ext4_dir_entry_2 **res_dir);
2173 extern int ext4_generic_delete_entry(handle_t *handle,
2174 				     struct inode *dir,
2175 				     struct ext4_dir_entry_2 *de_del,
2176 				     struct buffer_head *bh,
2177 				     void *entry_buf,
2178 				     int buf_size,
2179 				     int csum_size);
2180 
2181 /* resize.c */
2182 extern int ext4_group_add(struct super_block *sb,
2183 				struct ext4_new_group_data *input);
2184 extern int ext4_group_extend(struct super_block *sb,
2185 				struct ext4_super_block *es,
2186 				ext4_fsblk_t n_blocks_count);
2187 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2188 
2189 /* super.c */
2190 extern int ext4_calculate_overhead(struct super_block *sb);
2191 extern void ext4_superblock_csum_set(struct super_block *sb);
2192 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2193 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2194 extern void ext4_kvfree(void *ptr);
2195 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2196 				    ext4_group_t ngroup);
2197 extern const char *ext4_decode_error(struct super_block *sb, int errno,
2198 				     char nbuf[16]);
2199 
2200 extern __printf(4, 5)
2201 void __ext4_error(struct super_block *, const char *, unsigned int,
2202 		  const char *, ...);
2203 extern __printf(5, 6)
2204 void __ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2205 		      const char *, ...);
2206 extern __printf(5, 6)
2207 void __ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2208 		     const char *, ...);
2209 extern void __ext4_std_error(struct super_block *, const char *,
2210 			     unsigned int, int);
2211 extern __printf(4, 5)
2212 void __ext4_abort(struct super_block *, const char *, unsigned int,
2213 		  const char *, ...);
2214 extern __printf(4, 5)
2215 void __ext4_warning(struct super_block *, const char *, unsigned int,
2216 		    const char *, ...);
2217 extern __printf(3, 4)
2218 void __ext4_msg(struct super_block *, const char *, const char *, ...);
2219 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2220 			   const char *, unsigned int, const char *);
2221 extern __printf(7, 8)
2222 void __ext4_grp_locked_error(const char *, unsigned int,
2223 			     struct super_block *, ext4_group_t,
2224 			     unsigned long, ext4_fsblk_t,
2225 			     const char *, ...);
2226 
2227 #ifdef CONFIG_PRINTK
2228 
2229 #define ext4_error_inode(inode, func, line, block, fmt, ...)		\
2230 	__ext4_error_inode(inode, func, line, block, fmt, ##__VA_ARGS__)
2231 #define ext4_error_file(file, func, line, block, fmt, ...)		\
2232 	__ext4_error_file(file, func, line, block, fmt, ##__VA_ARGS__)
2233 #define ext4_error(sb, fmt, ...)					\
2234 	__ext4_error(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2235 #define ext4_abort(sb, fmt, ...)					\
2236 	__ext4_abort(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2237 #define ext4_warning(sb, fmt, ...)					\
2238 	__ext4_warning(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2239 #define ext4_msg(sb, level, fmt, ...)				\
2240 	__ext4_msg(sb, level, fmt, ##__VA_ARGS__)
2241 #define dump_mmp_msg(sb, mmp, msg)					\
2242 	__dump_mmp_msg(sb, mmp, __func__, __LINE__, msg)
2243 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)		\
2244 	__ext4_grp_locked_error(__func__, __LINE__, sb, grp, ino, block, \
2245 				fmt, ##__VA_ARGS__)
2246 
2247 #else
2248 
2249 #define ext4_error_inode(inode, func, line, block, fmt, ...)		\
2250 do {									\
2251 	no_printk(fmt, ##__VA_ARGS__);					\
2252 	__ext4_error_inode(inode, "", 0, block, " ");			\
2253 } while (0)
2254 #define ext4_error_file(file, func, line, block, fmt, ...)		\
2255 do {									\
2256 	no_printk(fmt, ##__VA_ARGS__);					\
2257 	__ext4_error_file(file, "", 0, block, " ");			\
2258 } while (0)
2259 #define ext4_error(sb, fmt, ...)					\
2260 do {									\
2261 	no_printk(fmt, ##__VA_ARGS__);					\
2262 	__ext4_error(sb, "", 0, " ");					\
2263 } while (0)
2264 #define ext4_abort(sb, fmt, ...)					\
2265 do {									\
2266 	no_printk(fmt, ##__VA_ARGS__);					\
2267 	__ext4_abort(sb, "", 0, " ");					\
2268 } while (0)
2269 #define ext4_warning(sb, fmt, ...)					\
2270 do {									\
2271 	no_printk(fmt, ##__VA_ARGS__);					\
2272 	__ext4_warning(sb, "", 0, " ");					\
2273 } while (0)
2274 #define ext4_msg(sb, level, fmt, ...)					\
2275 do {									\
2276 	no_printk(fmt, ##__VA_ARGS__);					\
2277 	__ext4_msg(sb, "", " ");					\
2278 } while (0)
2279 #define dump_mmp_msg(sb, mmp, msg)					\
2280 	__dump_mmp_msg(sb, mmp, "", 0, "")
2281 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)		\
2282 do {									\
2283 	no_printk(fmt, ##__VA_ARGS__);				\
2284 	__ext4_grp_locked_error("", 0, sb, grp, ino, block, " ");	\
2285 } while (0)
2286 
2287 #endif
2288 
2289 extern void ext4_update_dynamic_rev(struct super_block *sb);
2290 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2291 					__u32 compat);
2292 extern int ext4_update_rocompat_feature(handle_t *handle,
2293 					struct super_block *sb,	__u32 rocompat);
2294 extern int ext4_update_incompat_feature(handle_t *handle,
2295 					struct super_block *sb,	__u32 incompat);
2296 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2297 				      struct ext4_group_desc *bg);
2298 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2299 				      struct ext4_group_desc *bg);
2300 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2301 				     struct ext4_group_desc *bg);
2302 extern __u32 ext4_free_group_clusters(struct super_block *sb,
2303 				      struct ext4_group_desc *bg);
2304 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2305 				 struct ext4_group_desc *bg);
2306 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2307 				struct ext4_group_desc *bg);
2308 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2309 				   struct ext4_group_desc *bg);
2310 extern void ext4_block_bitmap_set(struct super_block *sb,
2311 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2312 extern void ext4_inode_bitmap_set(struct super_block *sb,
2313 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2314 extern void ext4_inode_table_set(struct super_block *sb,
2315 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
2316 extern void ext4_free_group_clusters_set(struct super_block *sb,
2317 					 struct ext4_group_desc *bg,
2318 					 __u32 count);
2319 extern void ext4_free_inodes_set(struct super_block *sb,
2320 				struct ext4_group_desc *bg, __u32 count);
2321 extern void ext4_used_dirs_set(struct super_block *sb,
2322 				struct ext4_group_desc *bg, __u32 count);
2323 extern void ext4_itable_unused_set(struct super_block *sb,
2324 				   struct ext4_group_desc *bg, __u32 count);
2325 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2326 				       struct ext4_group_desc *gdp);
2327 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2328 				     struct ext4_group_desc *gdp);
2329 extern int ext4_register_li_request(struct super_block *sb,
2330 				    ext4_group_t first_not_zeroed);
2331 
2332 static inline int ext4_has_group_desc_csum(struct super_block *sb)
2333 {
2334 	return EXT4_HAS_RO_COMPAT_FEATURE(sb,
2335 					  EXT4_FEATURE_RO_COMPAT_GDT_CSUM |
2336 					  EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
2337 }
2338 
2339 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2340 {
2341 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2342 		le32_to_cpu(es->s_blocks_count_lo);
2343 }
2344 
2345 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2346 {
2347 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2348 		le32_to_cpu(es->s_r_blocks_count_lo);
2349 }
2350 
2351 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2352 {
2353 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2354 		le32_to_cpu(es->s_free_blocks_count_lo);
2355 }
2356 
2357 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2358 					 ext4_fsblk_t blk)
2359 {
2360 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2361 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2362 }
2363 
2364 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2365 					      ext4_fsblk_t blk)
2366 {
2367 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2368 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2369 }
2370 
2371 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2372 					   ext4_fsblk_t blk)
2373 {
2374 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2375 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2376 }
2377 
2378 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2379 {
2380 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2381 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2382 			le32_to_cpu(raw_inode->i_size_lo);
2383 	else
2384 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2385 }
2386 
2387 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2388 {
2389 	raw_inode->i_size_lo = cpu_to_le32(i_size);
2390 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2391 }
2392 
2393 static inline
2394 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2395 					    ext4_group_t group)
2396 {
2397 	 struct ext4_group_info ***grp_info;
2398 	 long indexv, indexh;
2399 	 BUG_ON(group >= EXT4_SB(sb)->s_groups_count);
2400 	 grp_info = EXT4_SB(sb)->s_group_info;
2401 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2402 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2403 	 return grp_info[indexv][indexh];
2404 }
2405 
2406 /*
2407  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2408  * the locking protocol documented in the comments of ext4_group_add()
2409  * in resize.c
2410  */
2411 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2412 {
2413 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
2414 
2415 	smp_rmb();
2416 	return ngroups;
2417 }
2418 
2419 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2420 					     ext4_group_t block_group)
2421 {
2422 	return block_group >> sbi->s_log_groups_per_flex;
2423 }
2424 
2425 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2426 {
2427 	return 1 << sbi->s_log_groups_per_flex;
2428 }
2429 
2430 #define ext4_std_error(sb, errno)				\
2431 do {								\
2432 	if ((errno))						\
2433 		__ext4_std_error((sb), __func__, __LINE__, (errno));	\
2434 } while (0)
2435 
2436 #ifdef CONFIG_SMP
2437 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2438  * counters. So we need to make sure we have free clusters more
2439  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2440  */
2441 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2442 #else
2443 #define EXT4_FREECLUSTERS_WATERMARK 0
2444 #endif
2445 
2446 /* Update i_disksize. Requires i_mutex to avoid races with truncate */
2447 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2448 {
2449 	WARN_ON_ONCE(S_ISREG(inode->i_mode) &&
2450 		     !mutex_is_locked(&inode->i_mutex));
2451 	down_write(&EXT4_I(inode)->i_data_sem);
2452 	if (newsize > EXT4_I(inode)->i_disksize)
2453 		EXT4_I(inode)->i_disksize = newsize;
2454 	up_write(&EXT4_I(inode)->i_data_sem);
2455 }
2456 
2457 struct ext4_group_info {
2458 	unsigned long   bb_state;
2459 	struct rb_root  bb_free_root;
2460 	ext4_grpblk_t	bb_first_free;	/* first free block */
2461 	ext4_grpblk_t	bb_free;	/* total free blocks */
2462 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
2463 	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
2464 	struct          list_head bb_prealloc_list;
2465 #ifdef DOUBLE_CHECK
2466 	void            *bb_bitmap;
2467 #endif
2468 	struct rw_semaphore alloc_sem;
2469 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
2470 					 * regions, index is order.
2471 					 * bb_counters[3] = 5 means
2472 					 * 5 free 8-block regions. */
2473 };
2474 
2475 #define EXT4_GROUP_INFO_NEED_INIT_BIT		0
2476 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT		1
2477 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT	2
2478 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT	3
2479 
2480 #define EXT4_MB_GRP_NEED_INIT(grp)	\
2481 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2482 #define EXT4_MB_GRP_BBITMAP_CORRUPT(grp)	\
2483 	(test_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2484 #define EXT4_MB_GRP_IBITMAP_CORRUPT(grp)	\
2485 	(test_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2486 
2487 #define EXT4_MB_GRP_WAS_TRIMMED(grp)	\
2488 	(test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2489 #define EXT4_MB_GRP_SET_TRIMMED(grp)	\
2490 	(set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2491 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)	\
2492 	(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2493 
2494 #define EXT4_MAX_CONTENTION		8
2495 #define EXT4_CONTENTION_THRESHOLD	2
2496 
2497 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2498 					      ext4_group_t group)
2499 {
2500 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2501 }
2502 
2503 /*
2504  * Returns true if the filesystem is busy enough that attempts to
2505  * access the block group locks has run into contention.
2506  */
2507 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2508 {
2509 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2510 }
2511 
2512 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2513 {
2514 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2515 	if (spin_trylock(lock))
2516 		/*
2517 		 * We're able to grab the lock right away, so drop the
2518 		 * lock contention counter.
2519 		 */
2520 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2521 	else {
2522 		/*
2523 		 * The lock is busy, so bump the contention counter,
2524 		 * and then wait on the spin lock.
2525 		 */
2526 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2527 				  EXT4_MAX_CONTENTION);
2528 		spin_lock(lock);
2529 	}
2530 }
2531 
2532 static inline void ext4_unlock_group(struct super_block *sb,
2533 					ext4_group_t group)
2534 {
2535 	spin_unlock(ext4_group_lock_ptr(sb, group));
2536 }
2537 
2538 /*
2539  * Block validity checking
2540  */
2541 #define ext4_check_indirect_blockref(inode, bh)				\
2542 	ext4_check_blockref(__func__, __LINE__, inode,			\
2543 			    (__le32 *)(bh)->b_data,			\
2544 			    EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2545 
2546 #define ext4_ind_check_inode(inode)					\
2547 	ext4_check_blockref(__func__, __LINE__, inode,			\
2548 			    EXT4_I(inode)->i_data,			\
2549 			    EXT4_NDIR_BLOCKS)
2550 
2551 /*
2552  * Inodes and files operations
2553  */
2554 
2555 /* dir.c */
2556 extern const struct file_operations ext4_dir_operations;
2557 
2558 /* file.c */
2559 extern const struct inode_operations ext4_file_inode_operations;
2560 extern const struct file_operations ext4_file_operations;
2561 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2562 
2563 /* inline.c */
2564 extern int ext4_get_max_inline_size(struct inode *inode);
2565 extern int ext4_find_inline_data_nolock(struct inode *inode);
2566 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
2567 				 unsigned int len);
2568 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
2569 
2570 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
2571 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
2572 					 struct inode *inode,
2573 					 loff_t pos, unsigned len,
2574 					 unsigned flags,
2575 					 struct page **pagep);
2576 extern int ext4_write_inline_data_end(struct inode *inode,
2577 				      loff_t pos, unsigned len,
2578 				      unsigned copied,
2579 				      struct page *page);
2580 extern struct buffer_head *
2581 ext4_journalled_write_inline_data(struct inode *inode,
2582 				  unsigned len,
2583 				  struct page *page);
2584 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
2585 					   struct inode *inode,
2586 					   loff_t pos, unsigned len,
2587 					   unsigned flags,
2588 					   struct page **pagep,
2589 					   void **fsdata);
2590 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
2591 					 unsigned len, unsigned copied,
2592 					 struct page *page);
2593 extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
2594 				     struct inode *inode);
2595 extern int ext4_try_create_inline_dir(handle_t *handle,
2596 				      struct inode *parent,
2597 				      struct inode *inode);
2598 extern int ext4_read_inline_dir(struct file *filp,
2599 				struct dir_context *ctx,
2600 				int *has_inline_data);
2601 extern int htree_inlinedir_to_tree(struct file *dir_file,
2602 				   struct inode *dir, ext4_lblk_t block,
2603 				   struct dx_hash_info *hinfo,
2604 				   __u32 start_hash, __u32 start_minor_hash,
2605 				   int *has_inline_data);
2606 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
2607 					const struct qstr *d_name,
2608 					struct ext4_dir_entry_2 **res_dir,
2609 					int *has_inline_data);
2610 extern int ext4_delete_inline_entry(handle_t *handle,
2611 				    struct inode *dir,
2612 				    struct ext4_dir_entry_2 *de_del,
2613 				    struct buffer_head *bh,
2614 				    int *has_inline_data);
2615 extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
2616 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
2617 					struct ext4_dir_entry_2 **parent_de,
2618 					int *retval);
2619 extern int ext4_inline_data_fiemap(struct inode *inode,
2620 				   struct fiemap_extent_info *fieinfo,
2621 				   int *has_inline);
2622 extern int ext4_try_to_evict_inline_data(handle_t *handle,
2623 					 struct inode *inode,
2624 					 int needed);
2625 extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
2626 
2627 extern int ext4_convert_inline_data(struct inode *inode);
2628 
2629 static inline int ext4_has_inline_data(struct inode *inode)
2630 {
2631 	return ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA) &&
2632 	       EXT4_I(inode)->i_inline_off;
2633 }
2634 
2635 /* namei.c */
2636 extern const struct inode_operations ext4_dir_inode_operations;
2637 extern const struct inode_operations ext4_special_inode_operations;
2638 extern struct dentry *ext4_get_parent(struct dentry *child);
2639 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2640 				 struct ext4_dir_entry_2 *de,
2641 				 int blocksize, int csum_size,
2642 				 unsigned int parent_ino, int dotdot_real_len);
2643 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
2644 				   unsigned int blocksize);
2645 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
2646 					 struct inode *inode,
2647 					 struct buffer_head *bh);
2648 #define S_SHIFT 12
2649 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
2650 	[S_IFREG >> S_SHIFT]	= EXT4_FT_REG_FILE,
2651 	[S_IFDIR >> S_SHIFT]	= EXT4_FT_DIR,
2652 	[S_IFCHR >> S_SHIFT]	= EXT4_FT_CHRDEV,
2653 	[S_IFBLK >> S_SHIFT]	= EXT4_FT_BLKDEV,
2654 	[S_IFIFO >> S_SHIFT]	= EXT4_FT_FIFO,
2655 	[S_IFSOCK >> S_SHIFT]	= EXT4_FT_SOCK,
2656 	[S_IFLNK >> S_SHIFT]	= EXT4_FT_SYMLINK,
2657 };
2658 
2659 static inline void ext4_set_de_type(struct super_block *sb,
2660 				struct ext4_dir_entry_2 *de,
2661 				umode_t mode) {
2662 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
2663 		de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
2664 }
2665 
2666 
2667 /* symlink.c */
2668 extern const struct inode_operations ext4_symlink_inode_operations;
2669 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2670 
2671 /* block_validity */
2672 extern void ext4_release_system_zone(struct super_block *sb);
2673 extern int ext4_setup_system_zone(struct super_block *sb);
2674 extern int __init ext4_init_system_zone(void);
2675 extern void ext4_exit_system_zone(void);
2676 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2677 				 ext4_fsblk_t start_blk,
2678 				 unsigned int count);
2679 extern int ext4_check_blockref(const char *, unsigned int,
2680 			       struct inode *, __le32 *, unsigned int);
2681 
2682 /* extents.c */
2683 struct ext4_ext_path;
2684 struct ext4_extent;
2685 
2686 /*
2687  * Maximum number of logical blocks in a file; ext4_extent's ee_block is
2688  * __le32.
2689  */
2690 #define EXT_MAX_BLOCKS	0xffffffff
2691 
2692 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2693 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2694 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
2695 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2696 			       struct ext4_map_blocks *map, int flags);
2697 extern void ext4_ext_truncate(handle_t *, struct inode *);
2698 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2699 				 ext4_lblk_t end);
2700 extern void ext4_ext_init(struct super_block *);
2701 extern void ext4_ext_release(struct super_block *);
2702 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2703 			  loff_t len);
2704 extern int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
2705 					  loff_t offset, ssize_t len);
2706 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2707 			   struct ext4_map_blocks *map, int flags);
2708 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
2709 					 ext4_lblk_t lblocks);
2710 extern int ext4_extent_tree_init(handle_t *, struct inode *);
2711 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
2712 						   int num,
2713 						   struct ext4_ext_path *path);
2714 extern int ext4_can_extents_be_merged(struct inode *inode,
2715 				      struct ext4_extent *ex1,
2716 				      struct ext4_extent *ex2);
2717 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
2718 				  struct ext4_ext_path *,
2719 				  struct ext4_extent *, int);
2720 extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
2721 						  struct ext4_ext_path *,
2722 						  int flags);
2723 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
2724 extern int ext4_ext_check_inode(struct inode *inode);
2725 extern int ext4_find_delalloc_range(struct inode *inode,
2726 				    ext4_lblk_t lblk_start,
2727 				    ext4_lblk_t lblk_end);
2728 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
2729 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2730 			__u64 start, __u64 len);
2731 extern int ext4_ext_precache(struct inode *inode);
2732 extern int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len);
2733 
2734 /* move_extent.c */
2735 extern void ext4_double_down_write_data_sem(struct inode *first,
2736 					    struct inode *second);
2737 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
2738 					  struct inode *donor_inode);
2739 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2740 			     __u64 start_orig, __u64 start_donor,
2741 			     __u64 len, __u64 *moved_len);
2742 extern int mext_next_extent(struct inode *inode, struct ext4_ext_path *path,
2743 			    struct ext4_extent **extent);
2744 
2745 /* page-io.c */
2746 extern int __init ext4_init_pageio(void);
2747 extern void ext4_exit_pageio(void);
2748 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2749 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
2750 extern int ext4_put_io_end(ext4_io_end_t *io_end);
2751 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
2752 extern void ext4_io_submit_init(struct ext4_io_submit *io,
2753 				struct writeback_control *wbc);
2754 extern void ext4_end_io_rsv_work(struct work_struct *work);
2755 extern void ext4_io_submit(struct ext4_io_submit *io);
2756 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2757 			       struct page *page,
2758 			       int len,
2759 			       struct writeback_control *wbc,
2760 			       bool keep_towrite);
2761 
2762 /* mmp.c */
2763 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2764 
2765 /*
2766  * Note that these flags will never ever appear in a buffer_head's state flag.
2767  * See EXT4_MAP_... to see where this is used.
2768  */
2769 enum ext4_state_bits {
2770 	BH_AllocFromCluster	/* allocated blocks were part of already
2771 				 * allocated cluster. */
2772 	= BH_JBDPrivateStart
2773 };
2774 
2775 /*
2776  * Add new method to test whether block and inode bitmaps are properly
2777  * initialized. With uninit_bg reading the block from disk is not enough
2778  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2779  */
2780 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2781 
2782 static inline int bitmap_uptodate(struct buffer_head *bh)
2783 {
2784 	return (buffer_uptodate(bh) &&
2785 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2786 }
2787 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2788 {
2789 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2790 }
2791 
2792 /*
2793  * Disable DIO read nolock optimization, so new dioreaders will be forced
2794  * to grab i_mutex
2795  */
2796 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
2797 {
2798 	ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2799 	smp_mb();
2800 }
2801 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
2802 {
2803 	smp_mb();
2804 	ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2805 }
2806 
2807 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
2808 
2809 /* For ioend & aio unwritten conversion wait queues */
2810 #define EXT4_WQ_HASH_SZ		37
2811 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2812 					    EXT4_WQ_HASH_SZ])
2813 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2814 					     EXT4_WQ_HASH_SZ])
2815 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2816 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2817 
2818 #define EXT4_RESIZING	0
2819 extern int ext4_resize_begin(struct super_block *sb);
2820 extern void ext4_resize_end(struct super_block *sb);
2821 
2822 #endif	/* __KERNEL__ */
2823 
2824 #endif	/* _EXT4_H */
2825