xref: /openbmc/linux/fs/ext4/ext4.h (revision 4161b450)
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 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
162 				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY)
163 
164 struct ext4_map_blocks {
165 	ext4_fsblk_t m_pblk;
166 	ext4_lblk_t m_lblk;
167 	unsigned int m_len;
168 	unsigned int m_flags;
169 };
170 
171 /*
172  * Flags for ext4_io_end->flags
173  */
174 #define	EXT4_IO_END_UNWRITTEN	0x0001
175 
176 /*
177  * For converting unwritten extents on a work queue. 'handle' is used for
178  * buffered writeback.
179  */
180 typedef struct ext4_io_end {
181 	struct list_head	list;		/* per-file finished IO list */
182 	handle_t		*handle;	/* handle reserved for extent
183 						 * conversion */
184 	struct inode		*inode;		/* file being written to */
185 	struct bio		*bio;		/* Linked list of completed
186 						 * bios covering the extent */
187 	unsigned int		flag;		/* unwritten or not */
188 	loff_t			offset;		/* offset in the file */
189 	ssize_t			size;		/* size of the extent */
190 	atomic_t		count;		/* reference counter */
191 } ext4_io_end_t;
192 
193 struct ext4_io_submit {
194 	int			io_op;
195 	struct bio		*io_bio;
196 	ext4_io_end_t		*io_end;
197 	sector_t		io_next_block;
198 };
199 
200 /*
201  * Special inodes numbers
202  */
203 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
204 #define EXT4_ROOT_INO		 2	/* Root inode */
205 #define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
206 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
207 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
208 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
209 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
210 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
211 
212 /* First non-reserved inode for old ext4 filesystems */
213 #define EXT4_GOOD_OLD_FIRST_INO	11
214 
215 /*
216  * Maximal count of links to a file
217  */
218 #define EXT4_LINK_MAX		65000
219 
220 /*
221  * Macro-instructions used to manage several block sizes
222  */
223 #define EXT4_MIN_BLOCK_SIZE		1024
224 #define	EXT4_MAX_BLOCK_SIZE		65536
225 #define EXT4_MIN_BLOCK_LOG_SIZE		10
226 #define EXT4_MAX_BLOCK_LOG_SIZE		16
227 #ifdef __KERNEL__
228 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
229 #else
230 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
231 #endif
232 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
233 #define EXT4_CLUSTER_SIZE(s)		(EXT4_BLOCK_SIZE(s) << \
234 					 EXT4_SB(s)->s_cluster_bits)
235 #ifdef __KERNEL__
236 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
237 # define EXT4_CLUSTER_BITS(s)		(EXT4_SB(s)->s_cluster_bits)
238 #else
239 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
240 #endif
241 #ifdef __KERNEL__
242 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
243 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
244 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
245 #else
246 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
247 				 EXT4_GOOD_OLD_INODE_SIZE : \
248 				 (s)->s_inode_size)
249 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
250 				 EXT4_GOOD_OLD_FIRST_INO : \
251 				 (s)->s_first_ino)
252 #endif
253 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
254 
255 /* Translate a block number to a cluster number */
256 #define EXT4_B2C(sbi, blk)	((blk) >> (sbi)->s_cluster_bits)
257 /* Translate a cluster number to a block number */
258 #define EXT4_C2B(sbi, cluster)	((cluster) << (sbi)->s_cluster_bits)
259 /* Translate # of blks to # of clusters */
260 #define EXT4_NUM_B2C(sbi, blks)	(((blks) + (sbi)->s_cluster_ratio - 1) >> \
261 				 (sbi)->s_cluster_bits)
262 /* Mask out the low bits to get the starting block of the cluster */
263 #define EXT4_PBLK_CMASK(s, pblk) ((pblk) &				\
264 				  ~((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
265 #define EXT4_LBLK_CMASK(s, lblk) ((lblk) &				\
266 				  ~((ext4_lblk_t) (s)->s_cluster_ratio - 1))
267 /* Get the cluster offset */
268 #define EXT4_PBLK_COFF(s, pblk) ((pblk) &				\
269 				 ((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
270 #define EXT4_LBLK_COFF(s, lblk) ((lblk) &				\
271 				 ((ext4_lblk_t) (s)->s_cluster_ratio - 1))
272 
273 /*
274  * Structure of a blocks group descriptor
275  */
276 struct ext4_group_desc
277 {
278 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
279 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
280 	__le32	bg_inode_table_lo;	/* Inodes table block */
281 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
282 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
283 	__le16	bg_used_dirs_count_lo;	/* Directories count */
284 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
285 	__le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
286 	__le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
287 	__le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
288 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
289 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
290 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
291 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
292 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
293 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
294 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
295 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
296 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
297 	__le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
298 	__le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
299 	__le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
300 	__u32   bg_reserved;
301 };
302 
303 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END	\
304 	(offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
305 	 sizeof(__le16))
306 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END	\
307 	(offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
308 	 sizeof(__le16))
309 
310 /*
311  * Structure of a flex block group info
312  */
313 
314 struct flex_groups {
315 	atomic64_t	free_clusters;
316 	atomic_t	free_inodes;
317 	atomic_t	used_dirs;
318 };
319 
320 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
321 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
322 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
323 
324 /*
325  * Macro-instructions used to manage group descriptors
326  */
327 #define EXT4_MIN_DESC_SIZE		32
328 #define EXT4_MIN_DESC_SIZE_64BIT	64
329 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
330 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
331 #ifdef __KERNEL__
332 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
333 # define EXT4_CLUSTERS_PER_GROUP(s)	(EXT4_SB(s)->s_clusters_per_group)
334 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
335 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
336 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
337 #else
338 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
339 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
340 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
341 #endif
342 
343 /*
344  * Constants relative to the data blocks
345  */
346 #define	EXT4_NDIR_BLOCKS		12
347 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
348 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
349 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
350 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
351 
352 /*
353  * Inode flags
354  */
355 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
356 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
357 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
358 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
359 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
360 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
361 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
362 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
363 /* Reserved for compression usage... */
364 #define EXT4_DIRTY_FL			0x00000100
365 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
366 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
367 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
368 /* End compression flags --- maybe not all used */
369 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
370 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
371 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
372 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
373 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
374 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
375 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
376 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
377 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
378 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
379 #define EXT4_INLINE_DATA_FL		0x10000000 /* Inode has inline data. */
380 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
381 
382 #define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
383 #define EXT4_FL_USER_MODIFIABLE		0x004380FF /* User modifiable flags */
384 
385 /* Flags that should be inherited by new inodes from their parent. */
386 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
387 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
388 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
389 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
390 
391 /* Flags that are appropriate for regular files (all but dir-specific ones). */
392 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
393 
394 /* Flags that are appropriate for non-directories/regular files. */
395 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
396 
397 /* Mask out flags that are inappropriate for the given type of inode. */
398 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
399 {
400 	if (S_ISDIR(mode))
401 		return flags;
402 	else if (S_ISREG(mode))
403 		return flags & EXT4_REG_FLMASK;
404 	else
405 		return flags & EXT4_OTHER_FLMASK;
406 }
407 
408 /*
409  * Inode flags used for atomic set/get
410  */
411 enum {
412 	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
413 	EXT4_INODE_UNRM		= 1,	/* Undelete */
414 	EXT4_INODE_COMPR	= 2,	/* Compress file */
415 	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
416 	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
417 	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
418 	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
419 	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
420 /* Reserved for compression usage... */
421 	EXT4_INODE_DIRTY	= 8,
422 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
423 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
424 	EXT4_INODE_ECOMPR	= 11,	/* Compression error */
425 /* End compression flags --- maybe not all used */
426 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
427 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
428 	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
429 	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
430 	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
431 	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
432 	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
433 	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
434 	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
435 	EXT4_INODE_EOFBLOCKS	= 22,	/* Blocks allocated beyond EOF */
436 	EXT4_INODE_INLINE_DATA	= 28,	/* Data in inode. */
437 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
438 };
439 
440 /*
441  * Since it's pretty easy to mix up bit numbers and hex values, we use a
442  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
443  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
444  * any extra space in the compiled kernel image, otherwise, the build will fail.
445  * It's important that these values are the same, since we are using
446  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
447  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
448  * values found in ext2, ext3 and ext4 filesystems, and of course the values
449  * defined in e2fsprogs.
450  *
451  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
452  */
453 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
454 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
455 
456 static inline void ext4_check_flag_values(void)
457 {
458 	CHECK_FLAG_VALUE(SECRM);
459 	CHECK_FLAG_VALUE(UNRM);
460 	CHECK_FLAG_VALUE(COMPR);
461 	CHECK_FLAG_VALUE(SYNC);
462 	CHECK_FLAG_VALUE(IMMUTABLE);
463 	CHECK_FLAG_VALUE(APPEND);
464 	CHECK_FLAG_VALUE(NODUMP);
465 	CHECK_FLAG_VALUE(NOATIME);
466 	CHECK_FLAG_VALUE(DIRTY);
467 	CHECK_FLAG_VALUE(COMPRBLK);
468 	CHECK_FLAG_VALUE(NOCOMPR);
469 	CHECK_FLAG_VALUE(ECOMPR);
470 	CHECK_FLAG_VALUE(INDEX);
471 	CHECK_FLAG_VALUE(IMAGIC);
472 	CHECK_FLAG_VALUE(JOURNAL_DATA);
473 	CHECK_FLAG_VALUE(NOTAIL);
474 	CHECK_FLAG_VALUE(DIRSYNC);
475 	CHECK_FLAG_VALUE(TOPDIR);
476 	CHECK_FLAG_VALUE(HUGE_FILE);
477 	CHECK_FLAG_VALUE(EXTENTS);
478 	CHECK_FLAG_VALUE(EA_INODE);
479 	CHECK_FLAG_VALUE(EOFBLOCKS);
480 	CHECK_FLAG_VALUE(INLINE_DATA);
481 	CHECK_FLAG_VALUE(RESERVED);
482 }
483 
484 /* Used to pass group descriptor data when online resize is done */
485 struct ext4_new_group_input {
486 	__u32 group;		/* Group number for this data */
487 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
488 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
489 	__u64 inode_table;	/* Absolute block number of inode table start */
490 	__u32 blocks_count;	/* Total number of blocks in this group */
491 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
492 	__u16 unused;
493 };
494 
495 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
496 struct compat_ext4_new_group_input {
497 	u32 group;
498 	compat_u64 block_bitmap;
499 	compat_u64 inode_bitmap;
500 	compat_u64 inode_table;
501 	u32 blocks_count;
502 	u16 reserved_blocks;
503 	u16 unused;
504 };
505 #endif
506 
507 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
508 struct ext4_new_group_data {
509 	__u32 group;
510 	__u64 block_bitmap;
511 	__u64 inode_bitmap;
512 	__u64 inode_table;
513 	__u32 blocks_count;
514 	__u16 reserved_blocks;
515 	__u16 unused;
516 	__u32 free_blocks_count;
517 };
518 
519 /* Indexes used to index group tables in ext4_new_group_data */
520 enum {
521 	BLOCK_BITMAP = 0,	/* block bitmap */
522 	INODE_BITMAP,		/* inode bitmap */
523 	INODE_TABLE,		/* inode tables */
524 	GROUP_TABLE_COUNT,
525 };
526 
527 /*
528  * Flags used by ext4_map_blocks()
529  */
530 	/* Allocate any needed blocks and/or convert an unwritten
531 	   extent to be an initialized ext4 */
532 #define EXT4_GET_BLOCKS_CREATE			0x0001
533 	/* Request the creation of an unwritten extent */
534 #define EXT4_GET_BLOCKS_UNWRIT_EXT		0x0002
535 #define EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT	(EXT4_GET_BLOCKS_UNWRIT_EXT|\
536 						 EXT4_GET_BLOCKS_CREATE)
537 	/* Caller is from the delayed allocation writeout path
538 	 * finally doing the actual allocation of delayed blocks */
539 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
540 	/* caller is from the direct IO path, request to creation of an
541 	unwritten extents if not allocated, split the unwritten
542 	extent if blocks has been preallocated already*/
543 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
544 #define EXT4_GET_BLOCKS_CONVERT			0x0010
545 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
546 					 EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
547 	/* Convert extent to initialized after IO complete */
548 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
549 					 EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
550 	/* Eventual metadata allocation (due to growing extent tree)
551 	 * should not fail, so try to use reserved blocks for that.*/
552 #define EXT4_GET_BLOCKS_METADATA_NOFAIL		0x0020
553 	/* Don't normalize allocation size (used for fallocate) */
554 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
555 	/* Request will not result in inode size update (user for fallocate) */
556 #define EXT4_GET_BLOCKS_KEEP_SIZE		0x0080
557 	/* Do not take i_data_sem locking in ext4_map_blocks */
558 #define EXT4_GET_BLOCKS_NO_LOCK			0x0100
559 	/* Convert written extents to unwritten */
560 #define EXT4_GET_BLOCKS_CONVERT_UNWRITTEN	0x0200
561 
562 /*
563  * The bit position of these flags must not overlap with any of the
564  * EXT4_GET_BLOCKS_*.  They are used by ext4_find_extent(),
565  * read_extent_tree_block(), ext4_split_extent_at(),
566  * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf().
567  * EXT4_EX_NOCACHE is used to indicate that the we shouldn't be
568  * caching the extents when reading from the extent tree while a
569  * truncate or punch hole operation is in progress.
570  */
571 #define EXT4_EX_NOCACHE				0x40000000
572 #define EXT4_EX_FORCE_CACHE			0x20000000
573 
574 /*
575  * Flags used by ext4_free_blocks
576  */
577 #define EXT4_FREE_BLOCKS_METADATA	0x0001
578 #define EXT4_FREE_BLOCKS_FORGET		0x0002
579 #define EXT4_FREE_BLOCKS_VALIDATED	0x0004
580 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE	0x0008
581 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
582 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
583 
584 /*
585  * ioctl commands
586  */
587 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
588 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
589 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
590 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
591 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
592 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
593 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
594 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
595 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
596 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
597 #define EXT4_IOC_MIGRATE		_IO('f', 9)
598  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
599  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
600 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
601 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
602 #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
603 #define EXT4_IOC_SWAP_BOOT		_IO('f', 17)
604 #define EXT4_IOC_PRECACHE_EXTENTS	_IO('f', 18)
605 
606 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
607 /*
608  * ioctl commands in 32 bit emulation
609  */
610 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
611 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
612 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
613 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
614 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
615 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
616 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
617 #define EXT4_IOC32_GROUP_ADD		_IOW('f', 8, struct compat_ext4_new_group_input)
618 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
619 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
620 #endif
621 
622 /* Max physical block we can address w/o extents */
623 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
624 
625 /*
626  * Structure of an inode on the disk
627  */
628 struct ext4_inode {
629 	__le16	i_mode;		/* File mode */
630 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
631 	__le32	i_size_lo;	/* Size in bytes */
632 	__le32	i_atime;	/* Access time */
633 	__le32	i_ctime;	/* Inode Change time */
634 	__le32	i_mtime;	/* Modification time */
635 	__le32	i_dtime;	/* Deletion Time */
636 	__le16	i_gid;		/* Low 16 bits of Group Id */
637 	__le16	i_links_count;	/* Links count */
638 	__le32	i_blocks_lo;	/* Blocks count */
639 	__le32	i_flags;	/* File flags */
640 	union {
641 		struct {
642 			__le32  l_i_version;
643 		} linux1;
644 		struct {
645 			__u32  h_i_translator;
646 		} hurd1;
647 		struct {
648 			__u32  m_i_reserved1;
649 		} masix1;
650 	} osd1;				/* OS dependent 1 */
651 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
652 	__le32	i_generation;	/* File version (for NFS) */
653 	__le32	i_file_acl_lo;	/* File ACL */
654 	__le32	i_size_high;
655 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
656 	union {
657 		struct {
658 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
659 			__le16	l_i_file_acl_high;
660 			__le16	l_i_uid_high;	/* these 2 fields */
661 			__le16	l_i_gid_high;	/* were reserved2[0] */
662 			__le16	l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
663 			__le16	l_i_reserved;
664 		} linux2;
665 		struct {
666 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
667 			__u16	h_i_mode_high;
668 			__u16	h_i_uid_high;
669 			__u16	h_i_gid_high;
670 			__u32	h_i_author;
671 		} hurd2;
672 		struct {
673 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
674 			__le16	m_i_file_acl_high;
675 			__u32	m_i_reserved2[2];
676 		} masix2;
677 	} osd2;				/* OS dependent 2 */
678 	__le16	i_extra_isize;
679 	__le16	i_checksum_hi;	/* crc32c(uuid+inum+inode) BE */
680 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
681 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
682 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
683 	__le32  i_crtime;       /* File Creation time */
684 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
685 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
686 };
687 
688 struct move_extent {
689 	__u32 reserved;		/* should be zero */
690 	__u32 donor_fd;		/* donor file descriptor */
691 	__u64 orig_start;	/* logical start offset in block for orig */
692 	__u64 donor_start;	/* logical start offset in block for donor */
693 	__u64 len;		/* block length to be moved */
694 	__u64 moved_len;	/* moved block length */
695 };
696 
697 #define EXT4_EPOCH_BITS 2
698 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
699 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
700 
701 /*
702  * Extended fields will fit into an inode if the filesystem was formatted
703  * with large inodes (-I 256 or larger) and there are not currently any EAs
704  * consuming all of the available space. For new inodes we always reserve
705  * enough space for the kernel's known extended fields, but for inodes
706  * created with an old kernel this might not have been the case. None of
707  * the extended inode fields is critical for correct filesystem operation.
708  * This macro checks if a certain field fits in the inode. Note that
709  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
710  */
711 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
712 	((offsetof(typeof(*ext4_inode), field) +	\
713 	  sizeof((ext4_inode)->field))			\
714 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
715 	    (einode)->i_extra_isize))			\
716 
717 static inline __le32 ext4_encode_extra_time(struct timespec *time)
718 {
719        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
720 			   (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
721                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
722 }
723 
724 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
725 {
726        if (sizeof(time->tv_sec) > 4)
727 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
728 			       << 32;
729        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
730 }
731 
732 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
733 do {									       \
734 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
735 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
736 		(raw_inode)->xtime ## _extra =				       \
737 				ext4_encode_extra_time(&(inode)->xtime);       \
738 } while (0)
739 
740 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
741 do {									       \
742 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
743 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
744 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
745 		(raw_inode)->xtime ## _extra =				       \
746 				ext4_encode_extra_time(&(einode)->xtime);      \
747 } while (0)
748 
749 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
750 do {									       \
751 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
752 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
753 		ext4_decode_extra_time(&(inode)->xtime,			       \
754 				       raw_inode->xtime ## _extra);	       \
755 	else								       \
756 		(inode)->xtime.tv_nsec = 0;				       \
757 } while (0)
758 
759 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
760 do {									       \
761 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
762 		(einode)->xtime.tv_sec = 				       \
763 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
764 	else								       \
765 		(einode)->xtime.tv_sec = 0;				       \
766 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
767 		ext4_decode_extra_time(&(einode)->xtime,		       \
768 				       raw_inode->xtime ## _extra);	       \
769 	else								       \
770 		(einode)->xtime.tv_nsec = 0;				       \
771 } while (0)
772 
773 #define i_disk_version osd1.linux1.l_i_version
774 
775 #if defined(__KERNEL__) || defined(__linux__)
776 #define i_reserved1	osd1.linux1.l_i_reserved1
777 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
778 #define i_blocks_high	osd2.linux2.l_i_blocks_high
779 #define i_uid_low	i_uid
780 #define i_gid_low	i_gid
781 #define i_uid_high	osd2.linux2.l_i_uid_high
782 #define i_gid_high	osd2.linux2.l_i_gid_high
783 #define i_checksum_lo	osd2.linux2.l_i_checksum_lo
784 
785 #elif defined(__GNU__)
786 
787 #define i_translator	osd1.hurd1.h_i_translator
788 #define i_uid_high	osd2.hurd2.h_i_uid_high
789 #define i_gid_high	osd2.hurd2.h_i_gid_high
790 #define i_author	osd2.hurd2.h_i_author
791 
792 #elif defined(__masix__)
793 
794 #define i_reserved1	osd1.masix1.m_i_reserved1
795 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
796 #define i_reserved2	osd2.masix2.m_i_reserved2
797 
798 #endif /* defined(__KERNEL__) || defined(__linux__) */
799 
800 #include "extents_status.h"
801 
802 /*
803  * fourth extended file system inode data in memory
804  */
805 struct ext4_inode_info {
806 	__le32	i_data[15];	/* unconverted */
807 	__u32	i_dtime;
808 	ext4_fsblk_t	i_file_acl;
809 
810 	/*
811 	 * i_block_group is the number of the block group which contains
812 	 * this file's inode.  Constant across the lifetime of the inode,
813 	 * it is ued for making block allocation decisions - we try to
814 	 * place a file's data blocks near its inode block, and new inodes
815 	 * near to their parent directory's inode.
816 	 */
817 	ext4_group_t	i_block_group;
818 	ext4_lblk_t	i_dir_start_lookup;
819 #if (BITS_PER_LONG < 64)
820 	unsigned long	i_state_flags;		/* Dynamic state flags */
821 #endif
822 	unsigned long	i_flags;
823 
824 	/*
825 	 * Extended attributes can be read independently of the main file
826 	 * data. Taking i_mutex even when reading would cause contention
827 	 * between readers of EAs and writers of regular file data, so
828 	 * instead we synchronize on xattr_sem when reading or changing
829 	 * EAs.
830 	 */
831 	struct rw_semaphore xattr_sem;
832 
833 	struct list_head i_orphan;	/* unlinked but open inodes */
834 
835 	/*
836 	 * i_disksize keeps track of what the inode size is ON DISK, not
837 	 * in memory.  During truncate, i_size is set to the new size by
838 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
839 	 * set i_disksize to 0 until the truncate is actually under way.
840 	 *
841 	 * The intent is that i_disksize always represents the blocks which
842 	 * are used by this file.  This allows recovery to restart truncate
843 	 * on orphans if we crash during truncate.  We actually write i_disksize
844 	 * into the on-disk inode when writing inodes out, instead of i_size.
845 	 *
846 	 * The only time when i_disksize and i_size may be different is when
847 	 * a truncate is in progress.  The only things which change i_disksize
848 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
849 	 */
850 	loff_t	i_disksize;
851 
852 	/*
853 	 * i_data_sem is for serialising ext4_truncate() against
854 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
855 	 * data tree are chopped off during truncate. We can't do that in
856 	 * ext4 because whenever we perform intermediate commits during
857 	 * truncate, the inode and all the metadata blocks *must* be in a
858 	 * consistent state which allows truncation of the orphans to restart
859 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
860 	 * by other means, so we have i_data_sem.
861 	 */
862 	struct rw_semaphore i_data_sem;
863 	struct inode vfs_inode;
864 	struct jbd2_inode *jinode;
865 
866 	spinlock_t i_raw_lock;	/* protects updates to the raw inode */
867 
868 	/*
869 	 * File creation time. Its function is same as that of
870 	 * struct timespec i_{a,c,m}time in the generic inode.
871 	 */
872 	struct timespec i_crtime;
873 
874 	/* mballoc */
875 	struct list_head i_prealloc_list;
876 	spinlock_t i_prealloc_lock;
877 
878 	/* extents status tree */
879 	struct ext4_es_tree i_es_tree;
880 	rwlock_t i_es_lock;
881 	struct list_head i_es_list;
882 	unsigned int i_es_all_nr;	/* protected by i_es_lock */
883 	unsigned int i_es_shk_nr;	/* protected by i_es_lock */
884 	ext4_lblk_t i_es_shrink_lblk;	/* Offset where we start searching for
885 					   extents to shrink. Protected by
886 					   i_es_lock  */
887 
888 	/* ialloc */
889 	ext4_group_t	i_last_alloc_group;
890 
891 	/* allocation reservation info for delalloc */
892 	/* In case of bigalloc, these refer to clusters rather than blocks */
893 	unsigned int i_reserved_data_blocks;
894 	unsigned int i_reserved_meta_blocks;
895 	unsigned int i_allocated_meta_blocks;
896 	ext4_lblk_t i_da_metadata_calc_last_lblock;
897 	int i_da_metadata_calc_len;
898 
899 	/* on-disk additional length */
900 	__u16 i_extra_isize;
901 
902 	/* Indicate the inline data space. */
903 	u16 i_inline_off;
904 	u16 i_inline_size;
905 
906 #ifdef CONFIG_QUOTA
907 	/* quota space reservation, managed internally by quota code */
908 	qsize_t i_reserved_quota;
909 #endif
910 
911 	/* Lock protecting lists below */
912 	spinlock_t i_completed_io_lock;
913 	/*
914 	 * Completed IOs that need unwritten extents handling and have
915 	 * transaction reserved
916 	 */
917 	struct list_head i_rsv_conversion_list;
918 	/*
919 	 * Completed IOs that need unwritten extents handling and don't have
920 	 * transaction reserved
921 	 */
922 	atomic_t i_ioend_count;	/* Number of outstanding io_end structs */
923 	atomic_t i_unwritten; /* Nr. of inflight conversions pending */
924 	struct work_struct i_rsv_conversion_work;
925 
926 	spinlock_t i_block_reservation_lock;
927 
928 	/*
929 	 * Transactions that contain inode's metadata needed to complete
930 	 * fsync and fdatasync, respectively.
931 	 */
932 	tid_t i_sync_tid;
933 	tid_t i_datasync_tid;
934 
935 #ifdef CONFIG_QUOTA
936 	struct dquot *i_dquot[MAXQUOTAS];
937 #endif
938 
939 	/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
940 	__u32 i_csum_seed;
941 };
942 
943 /*
944  * File system states
945  */
946 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
947 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
948 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
949 
950 /*
951  * Misc. filesystem flags
952  */
953 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
954 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
955 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
956 
957 /*
958  * Mount flags set via mount options or defaults
959  */
960 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
961 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
962 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
963 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
964 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
965 #define EXT4_MOUNT_ERRORS_MASK		0x00070
966 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
967 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
968 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
969 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
970 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
971 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
972 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
973 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
974 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
975 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
976 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
977 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
978 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
979 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
980 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
981 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
982 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
983 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
984 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
985 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
986 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
987 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
988 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
989 
990 /*
991  * Mount flags set either automatically (could not be set by mount option)
992  * based on per file system feature or property or in special cases such as
993  * distinguishing between explicit mount option definition and default.
994  */
995 #define EXT4_MOUNT2_EXPLICIT_DELALLOC	0x00000001 /* User explicitly
996 						      specified delalloc */
997 #define EXT4_MOUNT2_STD_GROUP_SIZE	0x00000002 /* We have standard group
998 						      size of blocksize * 8
999 						      blocks */
1000 #define EXT4_MOUNT2_HURD_COMPAT		0x00000004 /* Support HURD-castrated
1001 						      file systems */
1002 
1003 #define clear_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt &= \
1004 						~EXT4_MOUNT_##opt
1005 #define set_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt |= \
1006 						EXT4_MOUNT_##opt
1007 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
1008 					 EXT4_MOUNT_##opt)
1009 
1010 #define clear_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 &= \
1011 						~EXT4_MOUNT2_##opt
1012 #define set_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 |= \
1013 						EXT4_MOUNT2_##opt
1014 #define test_opt2(sb, opt)		(EXT4_SB(sb)->s_mount_opt2 & \
1015 					 EXT4_MOUNT2_##opt)
1016 
1017 #define ext4_test_and_set_bit		__test_and_set_bit_le
1018 #define ext4_set_bit			__set_bit_le
1019 #define ext4_set_bit_atomic		ext2_set_bit_atomic
1020 #define ext4_test_and_clear_bit		__test_and_clear_bit_le
1021 #define ext4_clear_bit			__clear_bit_le
1022 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
1023 #define ext4_test_bit			test_bit_le
1024 #define ext4_find_next_zero_bit		find_next_zero_bit_le
1025 #define ext4_find_next_bit		find_next_bit_le
1026 
1027 extern void ext4_set_bits(void *bm, int cur, int len);
1028 
1029 /*
1030  * Maximal mount counts between two filesystem checks
1031  */
1032 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
1033 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
1034 
1035 /*
1036  * Behaviour when detecting errors
1037  */
1038 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
1039 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
1040 #define EXT4_ERRORS_PANIC		3	/* Panic */
1041 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
1042 
1043 /* Metadata checksum algorithm codes */
1044 #define EXT4_CRC32C_CHKSUM		1
1045 
1046 /*
1047  * Structure of the super block
1048  */
1049 struct ext4_super_block {
1050 /*00*/	__le32	s_inodes_count;		/* Inodes count */
1051 	__le32	s_blocks_count_lo;	/* Blocks count */
1052 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
1053 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
1054 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
1055 	__le32	s_first_data_block;	/* First Data Block */
1056 	__le32	s_log_block_size;	/* Block size */
1057 	__le32	s_log_cluster_size;	/* Allocation cluster size */
1058 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
1059 	__le32	s_clusters_per_group;	/* # Clusters per group */
1060 	__le32	s_inodes_per_group;	/* # Inodes per group */
1061 	__le32	s_mtime;		/* Mount time */
1062 /*30*/	__le32	s_wtime;		/* Write time */
1063 	__le16	s_mnt_count;		/* Mount count */
1064 	__le16	s_max_mnt_count;	/* Maximal mount count */
1065 	__le16	s_magic;		/* Magic signature */
1066 	__le16	s_state;		/* File system state */
1067 	__le16	s_errors;		/* Behaviour when detecting errors */
1068 	__le16	s_minor_rev_level;	/* minor revision level */
1069 /*40*/	__le32	s_lastcheck;		/* time of last check */
1070 	__le32	s_checkinterval;	/* max. time between checks */
1071 	__le32	s_creator_os;		/* OS */
1072 	__le32	s_rev_level;		/* Revision level */
1073 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
1074 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
1075 	/*
1076 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
1077 	 *
1078 	 * Note: the difference between the compatible feature set and
1079 	 * the incompatible feature set is that if there is a bit set
1080 	 * in the incompatible feature set that the kernel doesn't
1081 	 * know about, it should refuse to mount the filesystem.
1082 	 *
1083 	 * e2fsck's requirements are more strict; if it doesn't know
1084 	 * about a feature in either the compatible or incompatible
1085 	 * feature set, it must abort and not try to meddle with
1086 	 * things it doesn't understand...
1087 	 */
1088 	__le32	s_first_ino;		/* First non-reserved inode */
1089 	__le16  s_inode_size;		/* size of inode structure */
1090 	__le16	s_block_group_nr;	/* block group # of this superblock */
1091 	__le32	s_feature_compat;	/* compatible feature set */
1092 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
1093 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
1094 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
1095 /*78*/	char	s_volume_name[16];	/* volume name */
1096 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
1097 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
1098 	/*
1099 	 * Performance hints.  Directory preallocation should only
1100 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1101 	 */
1102 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
1103 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
1104 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
1105 	/*
1106 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1107 	 */
1108 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
1109 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
1110 	__le32	s_journal_dev;		/* device number of journal file */
1111 	__le32	s_last_orphan;		/* start of list of inodes to delete */
1112 	__le32	s_hash_seed[4];		/* HTREE hash seed */
1113 	__u8	s_def_hash_version;	/* Default hash version to use */
1114 	__u8	s_jnl_backup_type;
1115 	__le16  s_desc_size;		/* size of group descriptor */
1116 /*100*/	__le32	s_default_mount_opts;
1117 	__le32	s_first_meta_bg;	/* First metablock block group */
1118 	__le32	s_mkfs_time;		/* When the filesystem was created */
1119 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
1120 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1121 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
1122 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
1123 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
1124 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
1125 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
1126 	__le32	s_flags;		/* Miscellaneous flags */
1127 	__le16  s_raid_stride;		/* RAID stride */
1128 	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1129 	__le64  s_mmp_block;            /* Block for multi-mount protection */
1130 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1131 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
1132 	__u8	s_checksum_type;	/* metadata checksum algorithm used */
1133 	__le16  s_reserved_pad;
1134 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1135 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
1136 	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
1137 	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
1138 					      snapshot's future use */
1139 	__le32	s_snapshot_list;	/* inode number of the head of the
1140 					   on-disk snapshot list */
1141 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1142 	__le32	s_error_count;		/* number of fs errors */
1143 	__le32	s_first_error_time;	/* first time an error happened */
1144 	__le32	s_first_error_ino;	/* inode involved in first error */
1145 	__le64	s_first_error_block;	/* block involved of first error */
1146 	__u8	s_first_error_func[32];	/* function where the error happened */
1147 	__le32	s_first_error_line;	/* line number where error happened */
1148 	__le32	s_last_error_time;	/* most recent time of an error */
1149 	__le32	s_last_error_ino;	/* inode involved in last error */
1150 	__le32	s_last_error_line;	/* line number where error happened */
1151 	__le64	s_last_error_block;	/* block involved of last error */
1152 	__u8	s_last_error_func[32];	/* function where the error happened */
1153 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1154 	__u8	s_mount_opts[64];
1155 	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
1156 	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
1157 	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
1158 	__le32	s_backup_bgs[2];	/* groups with sparse_super2 SBs */
1159 	__le32	s_reserved[106];	/* Padding to the end of the block */
1160 	__le32	s_checksum;		/* crc32c(superblock) */
1161 };
1162 
1163 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1164 
1165 #ifdef __KERNEL__
1166 
1167 /*
1168  * run-time mount flags
1169  */
1170 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
1171 #define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
1172 
1173 /* Number of quota types we support */
1174 #define EXT4_MAXQUOTAS 2
1175 
1176 /*
1177  * fourth extended-fs super-block data in memory
1178  */
1179 struct ext4_sb_info {
1180 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
1181 	unsigned long s_inodes_per_block;/* Number of inodes per block */
1182 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
1183 	unsigned long s_clusters_per_group; /* Number of clusters in a group */
1184 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
1185 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
1186 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
1187 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
1188 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1189 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1190 	unsigned long s_overhead;  /* # of fs overhead clusters */
1191 	unsigned int s_cluster_ratio;	/* Number of blocks per cluster */
1192 	unsigned int s_cluster_bits;	/* log2 of s_cluster_ratio */
1193 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
1194 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
1195 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
1196 	struct buffer_head **s_group_desc;
1197 	unsigned int s_mount_opt;
1198 	unsigned int s_mount_opt2;
1199 	unsigned int s_mount_flags;
1200 	unsigned int s_def_mount_opt;
1201 	ext4_fsblk_t s_sb_block;
1202 	atomic64_t s_resv_clusters;
1203 	kuid_t s_resuid;
1204 	kgid_t s_resgid;
1205 	unsigned short s_mount_state;
1206 	unsigned short s_pad;
1207 	int s_addr_per_block_bits;
1208 	int s_desc_per_block_bits;
1209 	int s_inode_size;
1210 	int s_first_ino;
1211 	unsigned int s_inode_readahead_blks;
1212 	unsigned int s_inode_goal;
1213 	spinlock_t s_next_gen_lock;
1214 	u32 s_next_generation;
1215 	u32 s_hash_seed[4];
1216 	int s_def_hash_version;
1217 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
1218 	struct percpu_counter s_freeclusters_counter;
1219 	struct percpu_counter s_freeinodes_counter;
1220 	struct percpu_counter s_dirs_counter;
1221 	struct percpu_counter s_dirtyclusters_counter;
1222 	struct blockgroup_lock *s_blockgroup_lock;
1223 	struct proc_dir_entry *s_proc;
1224 	struct kobject s_kobj;
1225 	struct completion s_kobj_unregister;
1226 	struct super_block *s_sb;
1227 
1228 	/* Journaling */
1229 	struct journal_s *s_journal;
1230 	struct list_head s_orphan;
1231 	struct mutex s_orphan_lock;
1232 	unsigned long s_resize_flags;		/* Flags indicating if there
1233 						   is a resizer */
1234 	unsigned long s_commit_interval;
1235 	u32 s_max_batch_time;
1236 	u32 s_min_batch_time;
1237 	struct block_device *journal_bdev;
1238 #ifdef CONFIG_QUOTA
1239 	char *s_qf_names[EXT4_MAXQUOTAS];	/* Names of quota files with journalled quota */
1240 	int s_jquota_fmt;			/* Format of quota to use */
1241 #endif
1242 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1243 	struct rb_root system_blks;
1244 
1245 #ifdef EXTENTS_STATS
1246 	/* ext4 extents stats */
1247 	unsigned long s_ext_min;
1248 	unsigned long s_ext_max;
1249 	unsigned long s_depth_max;
1250 	spinlock_t s_ext_stats_lock;
1251 	unsigned long s_ext_blocks;
1252 	unsigned long s_ext_extents;
1253 #endif
1254 
1255 	/* for buddy allocator */
1256 	struct ext4_group_info ***s_group_info;
1257 	struct inode *s_buddy_cache;
1258 	spinlock_t s_md_lock;
1259 	unsigned short *s_mb_offsets;
1260 	unsigned int *s_mb_maxs;
1261 	unsigned int s_group_info_size;
1262 
1263 	/* tunables */
1264 	unsigned long s_stripe;
1265 	unsigned int s_mb_stream_request;
1266 	unsigned int s_mb_max_to_scan;
1267 	unsigned int s_mb_min_to_scan;
1268 	unsigned int s_mb_stats;
1269 	unsigned int s_mb_order2_reqs;
1270 	unsigned int s_mb_group_prealloc;
1271 	unsigned int s_max_dir_size_kb;
1272 	/* where last allocation was done - for stream allocation */
1273 	unsigned long s_mb_last_group;
1274 	unsigned long s_mb_last_start;
1275 
1276 	/* stats for buddy allocator */
1277 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1278 	atomic_t s_bal_success;	/* we found long enough chunks */
1279 	atomic_t s_bal_allocated;	/* in blocks */
1280 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1281 	atomic_t s_bal_goals;	/* goal hits */
1282 	atomic_t s_bal_breaks;	/* too long searches */
1283 	atomic_t s_bal_2orders;	/* 2^order hits */
1284 	spinlock_t s_bal_lock;
1285 	unsigned long s_mb_buddies_generated;
1286 	unsigned long long s_mb_generation_time;
1287 	atomic_t s_mb_lost_chunks;
1288 	atomic_t s_mb_preallocated;
1289 	atomic_t s_mb_discarded;
1290 	atomic_t s_lock_busy;
1291 
1292 	/* locality groups */
1293 	struct ext4_locality_group __percpu *s_locality_groups;
1294 
1295 	/* for write statistics */
1296 	unsigned long s_sectors_written_start;
1297 	u64 s_kbytes_written;
1298 
1299 	/* the size of zero-out chunk */
1300 	unsigned int s_extent_max_zeroout_kb;
1301 
1302 	unsigned int s_log_groups_per_flex;
1303 	struct flex_groups *s_flex_groups;
1304 	ext4_group_t s_flex_groups_allocated;
1305 
1306 	/* workqueue for reserved extent conversions (buffered io) */
1307 	struct workqueue_struct *rsv_conversion_wq;
1308 
1309 	/* timer for periodic error stats printing */
1310 	struct timer_list s_err_report;
1311 
1312 	/* Lazy inode table initialization info */
1313 	struct ext4_li_request *s_li_request;
1314 	/* Wait multiplier for lazy initialization thread */
1315 	unsigned int s_li_wait_mult;
1316 
1317 	/* Kernel thread for multiple mount protection */
1318 	struct task_struct *s_mmp_tsk;
1319 
1320 	/* record the last minlen when FITRIM is called. */
1321 	atomic_t s_last_trim_minblks;
1322 
1323 	/* Reference to checksum algorithm driver via cryptoapi */
1324 	struct crypto_shash *s_chksum_driver;
1325 
1326 	/* Precomputed FS UUID checksum for seeding other checksums */
1327 	__u32 s_csum_seed;
1328 
1329 	/* Reclaim extents from extent status tree */
1330 	struct shrinker s_es_shrinker;
1331 	struct list_head s_es_list;	/* List of inodes with reclaimable extents */
1332 	long s_es_nr_inode;
1333 	struct ext4_es_stats s_es_stats;
1334 	struct mb_cache *s_mb_cache;
1335 	spinlock_t s_es_lock ____cacheline_aligned_in_smp;
1336 
1337 	/* Ratelimit ext4 messages. */
1338 	struct ratelimit_state s_err_ratelimit_state;
1339 	struct ratelimit_state s_warning_ratelimit_state;
1340 	struct ratelimit_state s_msg_ratelimit_state;
1341 };
1342 
1343 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1344 {
1345 	return sb->s_fs_info;
1346 }
1347 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1348 {
1349 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1350 }
1351 
1352 static inline struct timespec ext4_current_time(struct inode *inode)
1353 {
1354 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1355 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1356 }
1357 
1358 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1359 {
1360 	return ino == EXT4_ROOT_INO ||
1361 		ino == EXT4_USR_QUOTA_INO ||
1362 		ino == EXT4_GRP_QUOTA_INO ||
1363 		ino == EXT4_BOOT_LOADER_INO ||
1364 		ino == EXT4_JOURNAL_INO ||
1365 		ino == EXT4_RESIZE_INO ||
1366 		(ino >= EXT4_FIRST_INO(sb) &&
1367 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1368 }
1369 
1370 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1371 					      struct ext4_io_end *io_end)
1372 {
1373 	if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1374 		io_end->flag |= EXT4_IO_END_UNWRITTEN;
1375 		atomic_inc(&EXT4_I(inode)->i_unwritten);
1376 	}
1377 }
1378 
1379 static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode)
1380 {
1381 	return inode->i_private;
1382 }
1383 
1384 static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io)
1385 {
1386 	inode->i_private = io;
1387 }
1388 
1389 /*
1390  * Inode dynamic state flags
1391  */
1392 enum {
1393 	EXT4_STATE_JDATA,		/* journaled data exists */
1394 	EXT4_STATE_NEW,			/* inode is newly created */
1395 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1396 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1397 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1398 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1399 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1400 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1401 	EXT4_STATE_DIOREAD_LOCK,	/* Disable support for dio read
1402 					   nolocking */
1403 	EXT4_STATE_MAY_INLINE_DATA,	/* may have in-inode data */
1404 	EXT4_STATE_ORDERED_MODE,	/* data=ordered mode */
1405 	EXT4_STATE_EXT_PRECACHED,	/* extents have been precached */
1406 };
1407 
1408 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
1409 static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
1410 {									\
1411 	return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);	\
1412 }									\
1413 static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
1414 {									\
1415 	set_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1416 }									\
1417 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1418 {									\
1419 	clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1420 }
1421 
1422 /* Add these declarations here only so that these functions can be
1423  * found by name.  Otherwise, they are very hard to locate. */
1424 static inline int ext4_test_inode_flag(struct inode *inode, int bit);
1425 static inline void ext4_set_inode_flag(struct inode *inode, int bit);
1426 static inline void ext4_clear_inode_flag(struct inode *inode, int bit);
1427 EXT4_INODE_BIT_FNS(flag, flags, 0)
1428 
1429 /* Add these declarations here only so that these functions can be
1430  * found by name.  Otherwise, they are very hard to locate. */
1431 static inline int ext4_test_inode_state(struct inode *inode, int bit);
1432 static inline void ext4_set_inode_state(struct inode *inode, int bit);
1433 static inline void ext4_clear_inode_state(struct inode *inode, int bit);
1434 #if (BITS_PER_LONG < 64)
1435 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1436 
1437 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1438 {
1439 	(ei)->i_state_flags = 0;
1440 }
1441 #else
1442 EXT4_INODE_BIT_FNS(state, flags, 32)
1443 
1444 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1445 {
1446 	/* We depend on the fact that callers will set i_flags */
1447 }
1448 #endif
1449 #else
1450 /* Assume that user mode programs are passing in an ext4fs superblock, not
1451  * a kernel struct super_block.  This will allow us to call the feature-test
1452  * macros from user land. */
1453 #define EXT4_SB(sb)	(sb)
1454 #endif
1455 
1456 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1457 
1458 /*
1459  * Codes for operating systems
1460  */
1461 #define EXT4_OS_LINUX		0
1462 #define EXT4_OS_HURD		1
1463 #define EXT4_OS_MASIX		2
1464 #define EXT4_OS_FREEBSD		3
1465 #define EXT4_OS_LITES		4
1466 
1467 /*
1468  * Revision levels
1469  */
1470 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1471 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1472 
1473 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1474 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1475 
1476 #define EXT4_GOOD_OLD_INODE_SIZE 128
1477 
1478 /*
1479  * Feature set definitions
1480  */
1481 
1482 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1483 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1484 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1485 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1486 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1487 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1488 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1489 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1490 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1491 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1492 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1493 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1494 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1495 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1496 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1497 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1498 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1499 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1500 
1501 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1502 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1503 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1504 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1505 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1506 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1507 #define EXT4_FEATURE_COMPAT_SPARSE_SUPER2	0x0200
1508 
1509 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1510 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1511 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1512 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1513 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1514 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1515 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1516 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
1517 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
1518 /*
1519  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1520  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1521  * all other data structures' checksums.  However, the METADATA_CSUM and
1522  * GDT_CSUM bits are mutually exclusive.
1523  */
1524 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
1525 
1526 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1527 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1528 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1529 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1530 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1531 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1532 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1533 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1534 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1535 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1536 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1537 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM	0x2000 /* use crc32c for bg */
1538 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
1539 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA	0x8000 /* data in inode */
1540 
1541 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1542 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1543 					 EXT4_FEATURE_INCOMPAT_META_BG)
1544 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1545 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1546 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1547 
1548 #define EXT3_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1549 #define EXT3_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1550 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1551 					 EXT4_FEATURE_INCOMPAT_META_BG)
1552 #define EXT3_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1553 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1554 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1555 
1556 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1557 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1558 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1559 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1560 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1561 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1562 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1563 					 EXT4_FEATURE_INCOMPAT_MMP |	\
1564 					 EXT4_FEATURE_INCOMPAT_INLINE_DATA)
1565 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1566 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1567 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1568 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1569 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1570 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1571 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1572 					 EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1573 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1574 					 EXT4_FEATURE_RO_COMPAT_QUOTA)
1575 
1576 /*
1577  * Default values for user and/or group using reserved blocks
1578  */
1579 #define	EXT4_DEF_RESUID		0
1580 #define	EXT4_DEF_RESGID		0
1581 
1582 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1583 
1584 /*
1585  * Default mount options
1586  */
1587 #define EXT4_DEFM_DEBUG		0x0001
1588 #define EXT4_DEFM_BSDGROUPS	0x0002
1589 #define EXT4_DEFM_XATTR_USER	0x0004
1590 #define EXT4_DEFM_ACL		0x0008
1591 #define EXT4_DEFM_UID16		0x0010
1592 #define EXT4_DEFM_JMODE		0x0060
1593 #define EXT4_DEFM_JMODE_DATA	0x0020
1594 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1595 #define EXT4_DEFM_JMODE_WBACK	0x0060
1596 #define EXT4_DEFM_NOBARRIER	0x0100
1597 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1598 #define EXT4_DEFM_DISCARD	0x0400
1599 #define EXT4_DEFM_NODELALLOC	0x0800
1600 
1601 /*
1602  * Default journal batch times
1603  */
1604 #define EXT4_DEF_MIN_BATCH_TIME	0
1605 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1606 
1607 /*
1608  * Minimum number of groups in a flexgroup before we separate out
1609  * directories into the first block group of a flexgroup
1610  */
1611 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1612 
1613 /*
1614  * Structure of a directory entry
1615  */
1616 #define EXT4_NAME_LEN 255
1617 
1618 struct ext4_dir_entry {
1619 	__le32	inode;			/* Inode number */
1620 	__le16	rec_len;		/* Directory entry length */
1621 	__le16	name_len;		/* Name length */
1622 	char	name[EXT4_NAME_LEN];	/* File name */
1623 };
1624 
1625 /*
1626  * The new version of the directory entry.  Since EXT4 structures are
1627  * stored in intel byte order, and the name_len field could never be
1628  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1629  * file_type field.
1630  */
1631 struct ext4_dir_entry_2 {
1632 	__le32	inode;			/* Inode number */
1633 	__le16	rec_len;		/* Directory entry length */
1634 	__u8	name_len;		/* Name length */
1635 	__u8	file_type;
1636 	char	name[EXT4_NAME_LEN];	/* File name */
1637 };
1638 
1639 /*
1640  * This is a bogus directory entry at the end of each leaf block that
1641  * records checksums.
1642  */
1643 struct ext4_dir_entry_tail {
1644 	__le32	det_reserved_zero1;	/* Pretend to be unused */
1645 	__le16	det_rec_len;		/* 12 */
1646 	__u8	det_reserved_zero2;	/* Zero name length */
1647 	__u8	det_reserved_ft;	/* 0xDE, fake file type */
1648 	__le32	det_checksum;		/* crc32c(uuid+inum+dirblock) */
1649 };
1650 
1651 #define EXT4_DIRENT_TAIL(block, blocksize) \
1652 	((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1653 					((blocksize) - \
1654 					 sizeof(struct ext4_dir_entry_tail))))
1655 
1656 /*
1657  * Ext4 directory file types.  Only the low 3 bits are used.  The
1658  * other bits are reserved for now.
1659  */
1660 #define EXT4_FT_UNKNOWN		0
1661 #define EXT4_FT_REG_FILE	1
1662 #define EXT4_FT_DIR		2
1663 #define EXT4_FT_CHRDEV		3
1664 #define EXT4_FT_BLKDEV		4
1665 #define EXT4_FT_FIFO		5
1666 #define EXT4_FT_SOCK		6
1667 #define EXT4_FT_SYMLINK		7
1668 
1669 #define EXT4_FT_MAX		8
1670 
1671 #define EXT4_FT_DIR_CSUM	0xDE
1672 
1673 /*
1674  * EXT4_DIR_PAD defines the directory entries boundaries
1675  *
1676  * NOTE: It must be a multiple of 4
1677  */
1678 #define EXT4_DIR_PAD			4
1679 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1680 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1681 					 ~EXT4_DIR_ROUND)
1682 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1683 
1684 /*
1685  * If we ever get support for fs block sizes > page_size, we'll need
1686  * to remove the #if statements in the next two functions...
1687  */
1688 static inline unsigned int
1689 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1690 {
1691 	unsigned len = le16_to_cpu(dlen);
1692 
1693 #if (PAGE_CACHE_SIZE >= 65536)
1694 	if (len == EXT4_MAX_REC_LEN || len == 0)
1695 		return blocksize;
1696 	return (len & 65532) | ((len & 3) << 16);
1697 #else
1698 	return len;
1699 #endif
1700 }
1701 
1702 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1703 {
1704 	if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1705 		BUG();
1706 #if (PAGE_CACHE_SIZE >= 65536)
1707 	if (len < 65536)
1708 		return cpu_to_le16(len);
1709 	if (len == blocksize) {
1710 		if (blocksize == 65536)
1711 			return cpu_to_le16(EXT4_MAX_REC_LEN);
1712 		else
1713 			return cpu_to_le16(0);
1714 	}
1715 	return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1716 #else
1717 	return cpu_to_le16(len);
1718 #endif
1719 }
1720 
1721 /*
1722  * Hash Tree Directory indexing
1723  * (c) Daniel Phillips, 2001
1724  */
1725 
1726 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1727 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1728 		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1729 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1730 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1731 
1732 /* Legal values for the dx_root hash_version field: */
1733 
1734 #define DX_HASH_LEGACY		0
1735 #define DX_HASH_HALF_MD4	1
1736 #define DX_HASH_TEA		2
1737 #define DX_HASH_LEGACY_UNSIGNED	3
1738 #define DX_HASH_HALF_MD4_UNSIGNED	4
1739 #define DX_HASH_TEA_UNSIGNED		5
1740 
1741 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1742 			      const void *address, unsigned int length)
1743 {
1744 	struct {
1745 		struct shash_desc shash;
1746 		char ctx[4];
1747 	} desc;
1748 	int err;
1749 
1750 	BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
1751 
1752 	desc.shash.tfm = sbi->s_chksum_driver;
1753 	desc.shash.flags = 0;
1754 	*(u32 *)desc.ctx = crc;
1755 
1756 	err = crypto_shash_update(&desc.shash, address, length);
1757 	BUG_ON(err);
1758 
1759 	return *(u32 *)desc.ctx;
1760 }
1761 
1762 #ifdef __KERNEL__
1763 
1764 /* hash info structure used by the directory hash */
1765 struct dx_hash_info
1766 {
1767 	u32		hash;
1768 	u32		minor_hash;
1769 	int		hash_version;
1770 	u32		*seed;
1771 };
1772 
1773 
1774 /* 32 and 64 bit signed EOF for dx directories */
1775 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
1776 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
1777 
1778 
1779 /*
1780  * Control parameters used by ext4_htree_next_block
1781  */
1782 #define HASH_NB_ALWAYS		1
1783 
1784 
1785 /*
1786  * Describe an inode's exact location on disk and in memory
1787  */
1788 struct ext4_iloc
1789 {
1790 	struct buffer_head *bh;
1791 	unsigned long offset;
1792 	ext4_group_t block_group;
1793 };
1794 
1795 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1796 {
1797 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1798 }
1799 
1800 /*
1801  * This structure is stuffed into the struct file's private_data field
1802  * for directories.  It is where we put information so that we can do
1803  * readdir operations in hash tree order.
1804  */
1805 struct dir_private_info {
1806 	struct rb_root	root;
1807 	struct rb_node	*curr_node;
1808 	struct fname	*extra_fname;
1809 	loff_t		last_pos;
1810 	__u32		curr_hash;
1811 	__u32		curr_minor_hash;
1812 	__u32		next_hash;
1813 };
1814 
1815 /* calculate the first block number of the group */
1816 static inline ext4_fsblk_t
1817 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1818 {
1819 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1820 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1821 }
1822 
1823 /*
1824  * Special error return code only used by dx_probe() and its callers.
1825  */
1826 #define ERR_BAD_DX_DIR	(-(MAX_ERRNO - 1))
1827 
1828 /*
1829  * Timeout and state flag for lazy initialization inode thread.
1830  */
1831 #define EXT4_DEF_LI_WAIT_MULT			10
1832 #define EXT4_DEF_LI_MAX_START_DELAY		5
1833 #define EXT4_LAZYINIT_QUIT			0x0001
1834 #define EXT4_LAZYINIT_RUNNING			0x0002
1835 
1836 /*
1837  * Lazy inode table initialization info
1838  */
1839 struct ext4_lazy_init {
1840 	unsigned long		li_state;
1841 	struct list_head	li_request_list;
1842 	struct mutex		li_list_mtx;
1843 };
1844 
1845 struct ext4_li_request {
1846 	struct super_block	*lr_super;
1847 	struct ext4_sb_info	*lr_sbi;
1848 	ext4_group_t		lr_next_group;
1849 	struct list_head	lr_request;
1850 	unsigned long		lr_next_sched;
1851 	unsigned long		lr_timeout;
1852 };
1853 
1854 struct ext4_features {
1855 	struct kobject f_kobj;
1856 	struct completion f_kobj_unregister;
1857 };
1858 
1859 /*
1860  * This structure will be used for multiple mount protection. It will be
1861  * written into the block number saved in the s_mmp_block field in the
1862  * superblock. Programs that check MMP should assume that if
1863  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1864  * to use the filesystem, regardless of how old the timestamp is.
1865  */
1866 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1867 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1868 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1869 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1870 
1871 struct mmp_struct {
1872 	__le32	mmp_magic;		/* Magic number for MMP */
1873 	__le32	mmp_seq;		/* Sequence no. updated periodically */
1874 
1875 	/*
1876 	 * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1877 	 * purposes and do not affect the correctness of the algorithm
1878 	 */
1879 	__le64	mmp_time;		/* Time last updated */
1880 	char	mmp_nodename[64];	/* Node which last updated MMP block */
1881 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
1882 
1883 	/*
1884 	 * mmp_check_interval is used to verify if the MMP block has been
1885 	 * updated on the block device. The value is updated based on the
1886 	 * maximum time to write the MMP block during an update cycle.
1887 	 */
1888 	__le16	mmp_check_interval;
1889 
1890 	__le16	mmp_pad1;
1891 	__le32	mmp_pad2[226];
1892 	__le32	mmp_checksum;		/* crc32c(uuid+mmp_block) */
1893 };
1894 
1895 /* arguments passed to the mmp thread */
1896 struct mmpd_data {
1897 	struct buffer_head *bh; /* bh from initial read_mmp_block() */
1898 	struct super_block *sb;  /* super block of the fs */
1899 };
1900 
1901 /*
1902  * Check interval multiplier
1903  * The MMP block is written every update interval and initially checked every
1904  * update interval x the multiplier (the value is then adapted based on the
1905  * write latency). The reason is that writes can be delayed under load and we
1906  * don't want readers to incorrectly assume that the filesystem is no longer
1907  * in use.
1908  */
1909 #define EXT4_MMP_CHECK_MULT		2UL
1910 
1911 /*
1912  * Minimum interval for MMP checking in seconds.
1913  */
1914 #define EXT4_MMP_MIN_CHECK_INTERVAL	5UL
1915 
1916 /*
1917  * Maximum interval for MMP checking in seconds.
1918  */
1919 #define EXT4_MMP_MAX_CHECK_INTERVAL	300UL
1920 
1921 /*
1922  * Function prototypes
1923  */
1924 
1925 /*
1926  * Ok, these declarations are also in <linux/kernel.h> but none of the
1927  * ext4 source programs needs to include it so they are duplicated here.
1928  */
1929 # define NORET_TYPE	/**/
1930 # define ATTRIB_NORET	__attribute__((noreturn))
1931 # define NORET_AND	noreturn,
1932 
1933 /* bitmap.c */
1934 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
1935 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1936 				struct ext4_group_desc *gdp,
1937 				struct buffer_head *bh, int sz);
1938 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1939 				  struct ext4_group_desc *gdp,
1940 				  struct buffer_head *bh, int sz);
1941 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1942 				struct ext4_group_desc *gdp,
1943 				struct buffer_head *bh);
1944 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1945 				  struct ext4_group_desc *gdp,
1946 				  struct buffer_head *bh);
1947 
1948 /* balloc.c */
1949 extern void ext4_get_group_no_and_offset(struct super_block *sb,
1950 					 ext4_fsblk_t blocknr,
1951 					 ext4_group_t *blockgrpp,
1952 					 ext4_grpblk_t *offsetp);
1953 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
1954 					  ext4_fsblk_t block);
1955 
1956 extern unsigned int ext4_block_group(struct super_block *sb,
1957 			ext4_fsblk_t blocknr);
1958 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1959 			ext4_fsblk_t blocknr);
1960 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1961 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1962 			ext4_group_t group);
1963 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1964 					 ext4_fsblk_t goal,
1965 					 unsigned int flags,
1966 					 unsigned long *count,
1967 					 int *errp);
1968 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1969 				    s64 nclusters, unsigned int flags);
1970 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1971 extern void ext4_check_blocks_bitmap(struct super_block *);
1972 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1973 						    ext4_group_t block_group,
1974 						    struct buffer_head ** bh);
1975 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1976 
1977 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1978 						ext4_group_t block_group);
1979 extern int ext4_wait_block_bitmap(struct super_block *sb,
1980 				  ext4_group_t block_group,
1981 				  struct buffer_head *bh);
1982 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1983 						  ext4_group_t block_group);
1984 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1985 					      ext4_group_t block_group,
1986 					      struct ext4_group_desc *gdp);
1987 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1988 
1989 /* dir.c */
1990 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1991 				  struct file *,
1992 				  struct ext4_dir_entry_2 *,
1993 				  struct buffer_head *, char *, int,
1994 				  unsigned int);
1995 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)	\
1996 	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1997 					(de), (bh), (buf), (size), (offset)))
1998 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1999 				    __u32 minor_hash,
2000 				    struct ext4_dir_entry_2 *dirent);
2001 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
2002 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
2003 			     struct buffer_head *bh,
2004 			     void *buf, int buf_size,
2005 			     const char *name, int namelen,
2006 			     struct ext4_dir_entry_2 **dest_de);
2007 void ext4_insert_dentry(struct inode *inode,
2008 			struct ext4_dir_entry_2 *de,
2009 			int buf_size,
2010 			const char *name, int namelen);
2011 static inline void ext4_update_dx_flag(struct inode *inode)
2012 {
2013 	if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
2014 				     EXT4_FEATURE_COMPAT_DIR_INDEX))
2015 		ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
2016 }
2017 static unsigned char ext4_filetype_table[] = {
2018 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
2019 };
2020 
2021 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
2022 {
2023 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
2024 	    (filetype >= EXT4_FT_MAX))
2025 		return DT_UNKNOWN;
2026 
2027 	return ext4_filetype_table[filetype];
2028 }
2029 extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
2030 			     void *buf, int buf_size);
2031 
2032 /* fsync.c */
2033 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2034 
2035 /* hash.c */
2036 extern int ext4fs_dirhash(const char *name, int len, struct
2037 			  dx_hash_info *hinfo);
2038 
2039 /* ialloc.c */
2040 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
2041 				      const struct qstr *qstr, __u32 goal,
2042 				      uid_t *owner, int handle_type,
2043 				      unsigned int line_no, int nblocks);
2044 
2045 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner) \
2046 	__ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
2047 			 0, 0, 0)
2048 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
2049 				    type, nblocks)		    \
2050 	__ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
2051 			 (type), __LINE__, (nblocks))
2052 
2053 
2054 extern void ext4_free_inode(handle_t *, struct inode *);
2055 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2056 extern unsigned long ext4_count_free_inodes(struct super_block *);
2057 extern unsigned long ext4_count_dirs(struct super_block *);
2058 extern void ext4_check_inodes_bitmap(struct super_block *);
2059 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2060 extern int ext4_init_inode_table(struct super_block *sb,
2061 				 ext4_group_t group, int barrier);
2062 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2063 
2064 /* mballoc.c */
2065 extern long ext4_mb_stats;
2066 extern long ext4_mb_max_to_scan;
2067 extern int ext4_mb_init(struct super_block *);
2068 extern int ext4_mb_release(struct super_block *);
2069 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2070 				struct ext4_allocation_request *, int *);
2071 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2072 extern void ext4_discard_preallocations(struct inode *);
2073 extern int __init ext4_init_mballoc(void);
2074 extern void ext4_exit_mballoc(void);
2075 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2076 			     struct buffer_head *bh, ext4_fsblk_t block,
2077 			     unsigned long count, int flags);
2078 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2079 				   ext4_group_t ngroups);
2080 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2081 		ext4_group_t i, struct ext4_group_desc *desc);
2082 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2083 				ext4_fsblk_t block, unsigned long count);
2084 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2085 
2086 /* inode.c */
2087 struct buffer_head *ext4_getblk(handle_t *, struct inode *, ext4_lblk_t, int);
2088 struct buffer_head *ext4_bread(handle_t *, struct inode *, ext4_lblk_t, int);
2089 int ext4_get_block_write(struct inode *inode, sector_t iblock,
2090 			 struct buffer_head *bh_result, int create);
2091 int ext4_get_block(struct inode *inode, sector_t iblock,
2092 				struct buffer_head *bh_result, int create);
2093 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2094 			   struct buffer_head *bh, int create);
2095 int ext4_walk_page_buffers(handle_t *handle,
2096 			   struct buffer_head *head,
2097 			   unsigned from,
2098 			   unsigned to,
2099 			   int *partial,
2100 			   int (*fn)(handle_t *handle,
2101 				     struct buffer_head *bh));
2102 int do_journal_get_write_access(handle_t *handle,
2103 				struct buffer_head *bh);
2104 #define FALL_BACK_TO_NONDELALLOC 1
2105 #define CONVERT_INLINE_DATA	 2
2106 
2107 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2108 extern struct inode *ext4_iget_normal(struct super_block *, unsigned long);
2109 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2110 extern int  ext4_setattr(struct dentry *, struct iattr *);
2111 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
2112 				struct kstat *stat);
2113 extern void ext4_evict_inode(struct inode *);
2114 extern void ext4_clear_inode(struct inode *);
2115 extern int  ext4_sync_inode(handle_t *, struct inode *);
2116 extern void ext4_dirty_inode(struct inode *, int);
2117 extern int ext4_change_inode_journal_flag(struct inode *, int);
2118 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2119 extern int ext4_inode_attach_jinode(struct inode *inode);
2120 extern int ext4_can_truncate(struct inode *inode);
2121 extern void ext4_truncate(struct inode *);
2122 extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length);
2123 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2124 extern void ext4_set_inode_flags(struct inode *);
2125 extern void ext4_get_inode_flags(struct ext4_inode_info *);
2126 extern int ext4_alloc_da_blocks(struct inode *inode);
2127 extern void ext4_set_aops(struct inode *inode);
2128 extern int ext4_writepage_trans_blocks(struct inode *);
2129 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2130 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
2131 			     loff_t lstart, loff_t lend);
2132 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2133 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2134 extern void ext4_da_update_reserve_space(struct inode *inode,
2135 					int used, int quota_claim);
2136 
2137 /* indirect.c */
2138 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2139 				struct ext4_map_blocks *map, int flags);
2140 extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
2141 				struct iov_iter *iter, loff_t offset);
2142 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2143 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2144 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2145 extern int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
2146 				 ext4_lblk_t start, ext4_lblk_t end);
2147 
2148 /* ioctl.c */
2149 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2150 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2151 
2152 /* migrate.c */
2153 extern int ext4_ext_migrate(struct inode *);
2154 extern int ext4_ind_migrate(struct inode *inode);
2155 
2156 /* namei.c */
2157 extern int ext4_dirent_csum_verify(struct inode *inode,
2158 				   struct ext4_dir_entry *dirent);
2159 extern int ext4_orphan_add(handle_t *, struct inode *);
2160 extern int ext4_orphan_del(handle_t *, struct inode *);
2161 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2162 				__u32 start_minor_hash, __u32 *next_hash);
2163 extern int search_dir(struct buffer_head *bh,
2164 		      char *search_buf,
2165 		      int buf_size,
2166 		      struct inode *dir,
2167 		      const struct qstr *d_name,
2168 		      unsigned int offset,
2169 		      struct ext4_dir_entry_2 **res_dir);
2170 extern int ext4_generic_delete_entry(handle_t *handle,
2171 				     struct inode *dir,
2172 				     struct ext4_dir_entry_2 *de_del,
2173 				     struct buffer_head *bh,
2174 				     void *entry_buf,
2175 				     int buf_size,
2176 				     int csum_size);
2177 
2178 /* resize.c */
2179 extern int ext4_group_add(struct super_block *sb,
2180 				struct ext4_new_group_data *input);
2181 extern int ext4_group_extend(struct super_block *sb,
2182 				struct ext4_super_block *es,
2183 				ext4_fsblk_t n_blocks_count);
2184 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2185 
2186 /* super.c */
2187 extern int ext4_calculate_overhead(struct super_block *sb);
2188 extern void ext4_superblock_csum_set(struct super_block *sb);
2189 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2190 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2191 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2192 				    ext4_group_t ngroup);
2193 extern const char *ext4_decode_error(struct super_block *sb, int errno,
2194 				     char nbuf[16]);
2195 
2196 extern __printf(4, 5)
2197 void __ext4_error(struct super_block *, const char *, unsigned int,
2198 		  const char *, ...);
2199 extern __printf(5, 6)
2200 void __ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2201 		      const char *, ...);
2202 extern __printf(5, 6)
2203 void __ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2204 		     const char *, ...);
2205 extern void __ext4_std_error(struct super_block *, const char *,
2206 			     unsigned int, int);
2207 extern __printf(4, 5)
2208 void __ext4_abort(struct super_block *, const char *, unsigned int,
2209 		  const char *, ...);
2210 extern __printf(4, 5)
2211 void __ext4_warning(struct super_block *, const char *, unsigned int,
2212 		    const char *, ...);
2213 extern __printf(3, 4)
2214 void __ext4_msg(struct super_block *, const char *, const char *, ...);
2215 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2216 			   const char *, unsigned int, const char *);
2217 extern __printf(7, 8)
2218 void __ext4_grp_locked_error(const char *, unsigned int,
2219 			     struct super_block *, ext4_group_t,
2220 			     unsigned long, ext4_fsblk_t,
2221 			     const char *, ...);
2222 
2223 #ifdef CONFIG_PRINTK
2224 
2225 #define ext4_error_inode(inode, func, line, block, fmt, ...)		\
2226 	__ext4_error_inode(inode, func, line, block, fmt, ##__VA_ARGS__)
2227 #define ext4_error_file(file, func, line, block, fmt, ...)		\
2228 	__ext4_error_file(file, func, line, block, fmt, ##__VA_ARGS__)
2229 #define ext4_error(sb, fmt, ...)					\
2230 	__ext4_error(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2231 #define ext4_abort(sb, fmt, ...)					\
2232 	__ext4_abort(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2233 #define ext4_warning(sb, fmt, ...)					\
2234 	__ext4_warning(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2235 #define ext4_msg(sb, level, fmt, ...)				\
2236 	__ext4_msg(sb, level, fmt, ##__VA_ARGS__)
2237 #define dump_mmp_msg(sb, mmp, msg)					\
2238 	__dump_mmp_msg(sb, mmp, __func__, __LINE__, msg)
2239 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)		\
2240 	__ext4_grp_locked_error(__func__, __LINE__, sb, grp, ino, block, \
2241 				fmt, ##__VA_ARGS__)
2242 
2243 #else
2244 
2245 #define ext4_error_inode(inode, func, line, block, fmt, ...)		\
2246 do {									\
2247 	no_printk(fmt, ##__VA_ARGS__);					\
2248 	__ext4_error_inode(inode, "", 0, block, " ");			\
2249 } while (0)
2250 #define ext4_error_file(file, func, line, block, fmt, ...)		\
2251 do {									\
2252 	no_printk(fmt, ##__VA_ARGS__);					\
2253 	__ext4_error_file(file, "", 0, block, " ");			\
2254 } while (0)
2255 #define ext4_error(sb, fmt, ...)					\
2256 do {									\
2257 	no_printk(fmt, ##__VA_ARGS__);					\
2258 	__ext4_error(sb, "", 0, " ");					\
2259 } while (0)
2260 #define ext4_abort(sb, fmt, ...)					\
2261 do {									\
2262 	no_printk(fmt, ##__VA_ARGS__);					\
2263 	__ext4_abort(sb, "", 0, " ");					\
2264 } while (0)
2265 #define ext4_warning(sb, fmt, ...)					\
2266 do {									\
2267 	no_printk(fmt, ##__VA_ARGS__);					\
2268 	__ext4_warning(sb, "", 0, " ");					\
2269 } while (0)
2270 #define ext4_msg(sb, level, fmt, ...)					\
2271 do {									\
2272 	no_printk(fmt, ##__VA_ARGS__);					\
2273 	__ext4_msg(sb, "", " ");					\
2274 } while (0)
2275 #define dump_mmp_msg(sb, mmp, msg)					\
2276 	__dump_mmp_msg(sb, mmp, "", 0, "")
2277 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)		\
2278 do {									\
2279 	no_printk(fmt, ##__VA_ARGS__);				\
2280 	__ext4_grp_locked_error("", 0, sb, grp, ino, block, " ");	\
2281 } while (0)
2282 
2283 #endif
2284 
2285 extern void ext4_update_dynamic_rev(struct super_block *sb);
2286 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2287 					__u32 compat);
2288 extern int ext4_update_rocompat_feature(handle_t *handle,
2289 					struct super_block *sb,	__u32 rocompat);
2290 extern int ext4_update_incompat_feature(handle_t *handle,
2291 					struct super_block *sb,	__u32 incompat);
2292 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2293 				      struct ext4_group_desc *bg);
2294 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2295 				      struct ext4_group_desc *bg);
2296 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2297 				     struct ext4_group_desc *bg);
2298 extern __u32 ext4_free_group_clusters(struct super_block *sb,
2299 				      struct ext4_group_desc *bg);
2300 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2301 				 struct ext4_group_desc *bg);
2302 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2303 				struct ext4_group_desc *bg);
2304 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2305 				   struct ext4_group_desc *bg);
2306 extern void ext4_block_bitmap_set(struct super_block *sb,
2307 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2308 extern void ext4_inode_bitmap_set(struct super_block *sb,
2309 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2310 extern void ext4_inode_table_set(struct super_block *sb,
2311 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
2312 extern void ext4_free_group_clusters_set(struct super_block *sb,
2313 					 struct ext4_group_desc *bg,
2314 					 __u32 count);
2315 extern void ext4_free_inodes_set(struct super_block *sb,
2316 				struct ext4_group_desc *bg, __u32 count);
2317 extern void ext4_used_dirs_set(struct super_block *sb,
2318 				struct ext4_group_desc *bg, __u32 count);
2319 extern void ext4_itable_unused_set(struct super_block *sb,
2320 				   struct ext4_group_desc *bg, __u32 count);
2321 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2322 				       struct ext4_group_desc *gdp);
2323 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2324 				     struct ext4_group_desc *gdp);
2325 extern int ext4_register_li_request(struct super_block *sb,
2326 				    ext4_group_t first_not_zeroed);
2327 
2328 static inline int ext4_has_group_desc_csum(struct super_block *sb)
2329 {
2330 	return EXT4_HAS_RO_COMPAT_FEATURE(sb,
2331 					  EXT4_FEATURE_RO_COMPAT_GDT_CSUM) ||
2332 	       (EXT4_SB(sb)->s_chksum_driver != NULL);
2333 }
2334 
2335 static inline int ext4_has_metadata_csum(struct super_block *sb)
2336 {
2337 	WARN_ON_ONCE(EXT4_HAS_RO_COMPAT_FEATURE(sb,
2338 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
2339 		     !EXT4_SB(sb)->s_chksum_driver);
2340 
2341 	return (EXT4_SB(sb)->s_chksum_driver != NULL);
2342 }
2343 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2344 {
2345 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2346 		le32_to_cpu(es->s_blocks_count_lo);
2347 }
2348 
2349 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2350 {
2351 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2352 		le32_to_cpu(es->s_r_blocks_count_lo);
2353 }
2354 
2355 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2356 {
2357 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2358 		le32_to_cpu(es->s_free_blocks_count_lo);
2359 }
2360 
2361 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2362 					 ext4_fsblk_t blk)
2363 {
2364 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2365 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2366 }
2367 
2368 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2369 					      ext4_fsblk_t blk)
2370 {
2371 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2372 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2373 }
2374 
2375 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2376 					   ext4_fsblk_t blk)
2377 {
2378 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2379 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2380 }
2381 
2382 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2383 {
2384 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2385 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2386 			le32_to_cpu(raw_inode->i_size_lo);
2387 	else
2388 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2389 }
2390 
2391 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2392 {
2393 	raw_inode->i_size_lo = cpu_to_le32(i_size);
2394 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2395 }
2396 
2397 static inline
2398 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2399 					    ext4_group_t group)
2400 {
2401 	 struct ext4_group_info ***grp_info;
2402 	 long indexv, indexh;
2403 	 BUG_ON(group >= EXT4_SB(sb)->s_groups_count);
2404 	 grp_info = EXT4_SB(sb)->s_group_info;
2405 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2406 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2407 	 return grp_info[indexv][indexh];
2408 }
2409 
2410 /*
2411  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2412  * the locking protocol documented in the comments of ext4_group_add()
2413  * in resize.c
2414  */
2415 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2416 {
2417 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
2418 
2419 	smp_rmb();
2420 	return ngroups;
2421 }
2422 
2423 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2424 					     ext4_group_t block_group)
2425 {
2426 	return block_group >> sbi->s_log_groups_per_flex;
2427 }
2428 
2429 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2430 {
2431 	return 1 << sbi->s_log_groups_per_flex;
2432 }
2433 
2434 #define ext4_std_error(sb, errno)				\
2435 do {								\
2436 	if ((errno))						\
2437 		__ext4_std_error((sb), __func__, __LINE__, (errno));	\
2438 } while (0)
2439 
2440 #ifdef CONFIG_SMP
2441 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2442  * counters. So we need to make sure we have free clusters more
2443  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2444  */
2445 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2446 #else
2447 #define EXT4_FREECLUSTERS_WATERMARK 0
2448 #endif
2449 
2450 /* Update i_disksize. Requires i_mutex to avoid races with truncate */
2451 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2452 {
2453 	WARN_ON_ONCE(S_ISREG(inode->i_mode) &&
2454 		     !mutex_is_locked(&inode->i_mutex));
2455 	down_write(&EXT4_I(inode)->i_data_sem);
2456 	if (newsize > EXT4_I(inode)->i_disksize)
2457 		EXT4_I(inode)->i_disksize = newsize;
2458 	up_write(&EXT4_I(inode)->i_data_sem);
2459 }
2460 
2461 /* Update i_size, i_disksize. Requires i_mutex to avoid races with truncate */
2462 static inline int ext4_update_inode_size(struct inode *inode, loff_t newsize)
2463 {
2464 	int changed = 0;
2465 
2466 	if (newsize > inode->i_size) {
2467 		i_size_write(inode, newsize);
2468 		changed = 1;
2469 	}
2470 	if (newsize > EXT4_I(inode)->i_disksize) {
2471 		ext4_update_i_disksize(inode, newsize);
2472 		changed |= 2;
2473 	}
2474 	return changed;
2475 }
2476 
2477 struct ext4_group_info {
2478 	unsigned long   bb_state;
2479 	struct rb_root  bb_free_root;
2480 	ext4_grpblk_t	bb_first_free;	/* first free block */
2481 	ext4_grpblk_t	bb_free;	/* total free blocks */
2482 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
2483 	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
2484 	struct          list_head bb_prealloc_list;
2485 #ifdef DOUBLE_CHECK
2486 	void            *bb_bitmap;
2487 #endif
2488 	struct rw_semaphore alloc_sem;
2489 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
2490 					 * regions, index is order.
2491 					 * bb_counters[3] = 5 means
2492 					 * 5 free 8-block regions. */
2493 };
2494 
2495 #define EXT4_GROUP_INFO_NEED_INIT_BIT		0
2496 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT		1
2497 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT	2
2498 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT	3
2499 
2500 #define EXT4_MB_GRP_NEED_INIT(grp)	\
2501 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2502 #define EXT4_MB_GRP_BBITMAP_CORRUPT(grp)	\
2503 	(test_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2504 #define EXT4_MB_GRP_IBITMAP_CORRUPT(grp)	\
2505 	(test_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2506 
2507 #define EXT4_MB_GRP_WAS_TRIMMED(grp)	\
2508 	(test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2509 #define EXT4_MB_GRP_SET_TRIMMED(grp)	\
2510 	(set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2511 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)	\
2512 	(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2513 
2514 #define EXT4_MAX_CONTENTION		8
2515 #define EXT4_CONTENTION_THRESHOLD	2
2516 
2517 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2518 					      ext4_group_t group)
2519 {
2520 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2521 }
2522 
2523 /*
2524  * Returns true if the filesystem is busy enough that attempts to
2525  * access the block group locks has run into contention.
2526  */
2527 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2528 {
2529 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2530 }
2531 
2532 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2533 {
2534 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2535 	if (spin_trylock(lock))
2536 		/*
2537 		 * We're able to grab the lock right away, so drop the
2538 		 * lock contention counter.
2539 		 */
2540 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2541 	else {
2542 		/*
2543 		 * The lock is busy, so bump the contention counter,
2544 		 * and then wait on the spin lock.
2545 		 */
2546 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2547 				  EXT4_MAX_CONTENTION);
2548 		spin_lock(lock);
2549 	}
2550 }
2551 
2552 static inline void ext4_unlock_group(struct super_block *sb,
2553 					ext4_group_t group)
2554 {
2555 	spin_unlock(ext4_group_lock_ptr(sb, group));
2556 }
2557 
2558 /*
2559  * Block validity checking
2560  */
2561 #define ext4_check_indirect_blockref(inode, bh)				\
2562 	ext4_check_blockref(__func__, __LINE__, inode,			\
2563 			    (__le32 *)(bh)->b_data,			\
2564 			    EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2565 
2566 #define ext4_ind_check_inode(inode)					\
2567 	ext4_check_blockref(__func__, __LINE__, inode,			\
2568 			    EXT4_I(inode)->i_data,			\
2569 			    EXT4_NDIR_BLOCKS)
2570 
2571 /*
2572  * Inodes and files operations
2573  */
2574 
2575 /* dir.c */
2576 extern const struct file_operations ext4_dir_operations;
2577 
2578 /* file.c */
2579 extern const struct inode_operations ext4_file_inode_operations;
2580 extern const struct file_operations ext4_file_operations;
2581 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2582 
2583 /* inline.c */
2584 extern int ext4_get_max_inline_size(struct inode *inode);
2585 extern int ext4_find_inline_data_nolock(struct inode *inode);
2586 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
2587 				 unsigned int len);
2588 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
2589 
2590 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
2591 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
2592 					 struct inode *inode,
2593 					 loff_t pos, unsigned len,
2594 					 unsigned flags,
2595 					 struct page **pagep);
2596 extern int ext4_write_inline_data_end(struct inode *inode,
2597 				      loff_t pos, unsigned len,
2598 				      unsigned copied,
2599 				      struct page *page);
2600 extern struct buffer_head *
2601 ext4_journalled_write_inline_data(struct inode *inode,
2602 				  unsigned len,
2603 				  struct page *page);
2604 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
2605 					   struct inode *inode,
2606 					   loff_t pos, unsigned len,
2607 					   unsigned flags,
2608 					   struct page **pagep,
2609 					   void **fsdata);
2610 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
2611 					 unsigned len, unsigned copied,
2612 					 struct page *page);
2613 extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
2614 				     struct inode *inode);
2615 extern int ext4_try_create_inline_dir(handle_t *handle,
2616 				      struct inode *parent,
2617 				      struct inode *inode);
2618 extern int ext4_read_inline_dir(struct file *filp,
2619 				struct dir_context *ctx,
2620 				int *has_inline_data);
2621 extern int htree_inlinedir_to_tree(struct file *dir_file,
2622 				   struct inode *dir, ext4_lblk_t block,
2623 				   struct dx_hash_info *hinfo,
2624 				   __u32 start_hash, __u32 start_minor_hash,
2625 				   int *has_inline_data);
2626 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
2627 					const struct qstr *d_name,
2628 					struct ext4_dir_entry_2 **res_dir,
2629 					int *has_inline_data);
2630 extern int ext4_delete_inline_entry(handle_t *handle,
2631 				    struct inode *dir,
2632 				    struct ext4_dir_entry_2 *de_del,
2633 				    struct buffer_head *bh,
2634 				    int *has_inline_data);
2635 extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
2636 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
2637 					struct ext4_dir_entry_2 **parent_de,
2638 					int *retval);
2639 extern int ext4_inline_data_fiemap(struct inode *inode,
2640 				   struct fiemap_extent_info *fieinfo,
2641 				   int *has_inline, __u64 start, __u64 len);
2642 extern int ext4_try_to_evict_inline_data(handle_t *handle,
2643 					 struct inode *inode,
2644 					 int needed);
2645 extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
2646 
2647 extern int ext4_convert_inline_data(struct inode *inode);
2648 
2649 static inline int ext4_has_inline_data(struct inode *inode)
2650 {
2651 	return ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA) &&
2652 	       EXT4_I(inode)->i_inline_off;
2653 }
2654 
2655 /* namei.c */
2656 extern const struct inode_operations ext4_dir_inode_operations;
2657 extern const struct inode_operations ext4_special_inode_operations;
2658 extern struct dentry *ext4_get_parent(struct dentry *child);
2659 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2660 				 struct ext4_dir_entry_2 *de,
2661 				 int blocksize, int csum_size,
2662 				 unsigned int parent_ino, int dotdot_real_len);
2663 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
2664 				   unsigned int blocksize);
2665 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
2666 					 struct inode *inode,
2667 					 struct buffer_head *bh);
2668 #define S_SHIFT 12
2669 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
2670 	[S_IFREG >> S_SHIFT]	= EXT4_FT_REG_FILE,
2671 	[S_IFDIR >> S_SHIFT]	= EXT4_FT_DIR,
2672 	[S_IFCHR >> S_SHIFT]	= EXT4_FT_CHRDEV,
2673 	[S_IFBLK >> S_SHIFT]	= EXT4_FT_BLKDEV,
2674 	[S_IFIFO >> S_SHIFT]	= EXT4_FT_FIFO,
2675 	[S_IFSOCK >> S_SHIFT]	= EXT4_FT_SOCK,
2676 	[S_IFLNK >> S_SHIFT]	= EXT4_FT_SYMLINK,
2677 };
2678 
2679 static inline void ext4_set_de_type(struct super_block *sb,
2680 				struct ext4_dir_entry_2 *de,
2681 				umode_t mode) {
2682 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
2683 		de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
2684 }
2685 
2686 
2687 /* symlink.c */
2688 extern const struct inode_operations ext4_symlink_inode_operations;
2689 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2690 
2691 /* block_validity */
2692 extern void ext4_release_system_zone(struct super_block *sb);
2693 extern int ext4_setup_system_zone(struct super_block *sb);
2694 extern int __init ext4_init_system_zone(void);
2695 extern void ext4_exit_system_zone(void);
2696 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2697 				 ext4_fsblk_t start_blk,
2698 				 unsigned int count);
2699 extern int ext4_check_blockref(const char *, unsigned int,
2700 			       struct inode *, __le32 *, unsigned int);
2701 
2702 /* extents.c */
2703 struct ext4_ext_path;
2704 struct ext4_extent;
2705 
2706 /*
2707  * Maximum number of logical blocks in a file; ext4_extent's ee_block is
2708  * __le32.
2709  */
2710 #define EXT_MAX_BLOCKS	0xffffffff
2711 
2712 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2713 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2714 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
2715 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2716 			       struct ext4_map_blocks *map, int flags);
2717 extern void ext4_ext_truncate(handle_t *, struct inode *);
2718 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2719 				 ext4_lblk_t end);
2720 extern void ext4_ext_init(struct super_block *);
2721 extern void ext4_ext_release(struct super_block *);
2722 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2723 			  loff_t len);
2724 extern int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
2725 					  loff_t offset, ssize_t len);
2726 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2727 			   struct ext4_map_blocks *map, int flags);
2728 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
2729 					 ext4_lblk_t lblocks);
2730 extern int ext4_extent_tree_init(handle_t *, struct inode *);
2731 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
2732 						   int num,
2733 						   struct ext4_ext_path *path);
2734 extern int ext4_can_extents_be_merged(struct inode *inode,
2735 				      struct ext4_extent *ex1,
2736 				      struct ext4_extent *ex2);
2737 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
2738 				  struct ext4_ext_path **,
2739 				  struct ext4_extent *, int);
2740 extern struct ext4_ext_path *ext4_find_extent(struct inode *, ext4_lblk_t,
2741 					      struct ext4_ext_path **,
2742 					      int flags);
2743 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
2744 extern int ext4_ext_check_inode(struct inode *inode);
2745 extern int ext4_find_delalloc_range(struct inode *inode,
2746 				    ext4_lblk_t lblk_start,
2747 				    ext4_lblk_t lblk_end);
2748 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
2749 extern ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path);
2750 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2751 			__u64 start, __u64 len);
2752 extern int ext4_ext_precache(struct inode *inode);
2753 extern int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len);
2754 extern int ext4_swap_extents(handle_t *handle, struct inode *inode1,
2755 				struct inode *inode2, ext4_lblk_t lblk1,
2756 			     ext4_lblk_t lblk2,  ext4_lblk_t count,
2757 			     int mark_unwritten,int *err);
2758 
2759 /* move_extent.c */
2760 extern void ext4_double_down_write_data_sem(struct inode *first,
2761 					    struct inode *second);
2762 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
2763 					  struct inode *donor_inode);
2764 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2765 			     __u64 start_orig, __u64 start_donor,
2766 			     __u64 len, __u64 *moved_len);
2767 
2768 /* page-io.c */
2769 extern int __init ext4_init_pageio(void);
2770 extern void ext4_exit_pageio(void);
2771 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2772 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
2773 extern int ext4_put_io_end(ext4_io_end_t *io_end);
2774 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
2775 extern void ext4_io_submit_init(struct ext4_io_submit *io,
2776 				struct writeback_control *wbc);
2777 extern void ext4_end_io_rsv_work(struct work_struct *work);
2778 extern void ext4_io_submit(struct ext4_io_submit *io);
2779 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2780 			       struct page *page,
2781 			       int len,
2782 			       struct writeback_control *wbc,
2783 			       bool keep_towrite);
2784 
2785 /* mmp.c */
2786 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2787 
2788 /*
2789  * Add new method to test whether block and inode bitmaps are properly
2790  * initialized. With uninit_bg reading the block from disk is not enough
2791  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2792  */
2793 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2794 
2795 static inline int bitmap_uptodate(struct buffer_head *bh)
2796 {
2797 	return (buffer_uptodate(bh) &&
2798 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2799 }
2800 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2801 {
2802 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2803 }
2804 
2805 /*
2806  * Disable DIO read nolock optimization, so new dioreaders will be forced
2807  * to grab i_mutex
2808  */
2809 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
2810 {
2811 	ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2812 	smp_mb();
2813 }
2814 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
2815 {
2816 	smp_mb();
2817 	ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2818 }
2819 
2820 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
2821 
2822 /* For ioend & aio unwritten conversion wait queues */
2823 #define EXT4_WQ_HASH_SZ		37
2824 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2825 					    EXT4_WQ_HASH_SZ])
2826 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2827 					     EXT4_WQ_HASH_SZ])
2828 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2829 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2830 
2831 #define EXT4_RESIZING	0
2832 extern int ext4_resize_begin(struct super_block *sb);
2833 extern void ext4_resize_end(struct super_block *sb);
2834 
2835 #endif	/* __KERNEL__ */
2836 
2837 #endif	/* _EXT4_H */
2838