xref: /openbmc/linux/fs/ext4/ext4.h (revision 4fbf888a)
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 #ifdef __KERNEL__
35 #include <linux/compat.h>
36 #endif
37 
38 /*
39  * The fourth extended filesystem constants/structures
40  */
41 
42 /*
43  * Define EXT4FS_DEBUG to produce debug messages
44  */
45 #undef EXT4FS_DEBUG
46 
47 /*
48  * Debug code
49  */
50 #ifdef EXT4FS_DEBUG
51 #define ext4_debug(f, a...)						\
52 	do {								\
53 		printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",	\
54 			__FILE__, __LINE__, __func__);			\
55 		printk(KERN_DEBUG f, ## a);				\
56 	} while (0)
57 #else
58 #define ext4_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
59 #endif
60 
61 /*
62  * Turn on EXT_DEBUG to get lots of info about extents operations.
63  */
64 #define EXT_DEBUG__
65 #ifdef EXT_DEBUG
66 #define ext_debug(fmt, ...)	printk(fmt, ##__VA_ARGS__)
67 #else
68 #define ext_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
69 #endif
70 
71 #define EXT4_ERROR_INODE(inode, fmt, a...) \
72 	ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
73 
74 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)			\
75 	ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
76 
77 #define EXT4_ERROR_FILE(file, block, fmt, a...)				\
78 	ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
79 
80 /* data type for block offset of block group */
81 typedef int ext4_grpblk_t;
82 
83 /* data type for filesystem-wide blocks number */
84 typedef unsigned long long ext4_fsblk_t;
85 
86 /* data type for file logical block number */
87 typedef __u32 ext4_lblk_t;
88 
89 /* data type for block group number */
90 typedef unsigned int ext4_group_t;
91 
92 /*
93  * Flags used in mballoc's allocation_context flags field.
94  *
95  * Also used to show what's going on for debugging purposes when the
96  * flag field is exported via the traceport interface
97  */
98 
99 /* prefer goal again. length */
100 #define EXT4_MB_HINT_MERGE		0x0001
101 /* blocks already reserved */
102 #define EXT4_MB_HINT_RESERVED		0x0002
103 /* metadata is being allocated */
104 #define EXT4_MB_HINT_METADATA		0x0004
105 /* first blocks in the file */
106 #define EXT4_MB_HINT_FIRST		0x0008
107 /* search for the best chunk */
108 #define EXT4_MB_HINT_BEST		0x0010
109 /* data is being allocated */
110 #define EXT4_MB_HINT_DATA		0x0020
111 /* don't preallocate (for tails) */
112 #define EXT4_MB_HINT_NOPREALLOC		0x0040
113 /* allocate for locality group */
114 #define EXT4_MB_HINT_GROUP_ALLOC	0x0080
115 /* allocate goal blocks or none */
116 #define EXT4_MB_HINT_GOAL_ONLY		0x0100
117 /* goal is meaningful */
118 #define EXT4_MB_HINT_TRY_GOAL		0x0200
119 /* blocks already pre-reserved by delayed allocation */
120 #define EXT4_MB_DELALLOC_RESERVED	0x0400
121 /* We are doing stream allocation */
122 #define EXT4_MB_STREAM_ALLOC		0x0800
123 /* Use reserved root blocks if needed */
124 #define EXT4_MB_USE_ROOT_BLOCKS		0x1000
125 /* Use blocks from reserved pool */
126 #define EXT4_MB_USE_RESERVED		0x2000
127 
128 struct ext4_allocation_request {
129 	/* target inode for block we're allocating */
130 	struct inode *inode;
131 	/* how many blocks we want to allocate */
132 	unsigned int len;
133 	/* logical block in target inode */
134 	ext4_lblk_t logical;
135 	/* the closest logical allocated block to the left */
136 	ext4_lblk_t lleft;
137 	/* the closest logical allocated block to the right */
138 	ext4_lblk_t lright;
139 	/* phys. target (a hint) */
140 	ext4_fsblk_t goal;
141 	/* phys. block for the closest logical allocated block to the left */
142 	ext4_fsblk_t pleft;
143 	/* phys. block for the closest logical allocated block to the right */
144 	ext4_fsblk_t pright;
145 	/* flags. see above EXT4_MB_HINT_* */
146 	unsigned int flags;
147 };
148 
149 /*
150  * Logical to physical block mapping, used by ext4_map_blocks()
151  *
152  * This structure is used to pass requests into ext4_map_blocks() as
153  * well as to store the information returned by ext4_map_blocks().  It
154  * takes less room on the stack than a struct buffer_head.
155  */
156 #define EXT4_MAP_NEW		(1 << BH_New)
157 #define EXT4_MAP_MAPPED		(1 << BH_Mapped)
158 #define EXT4_MAP_UNWRITTEN	(1 << BH_Unwritten)
159 #define EXT4_MAP_BOUNDARY	(1 << BH_Boundary)
160 #define EXT4_MAP_UNINIT		(1 << BH_Uninit)
161 /* Sometimes (in the bigalloc case, from ext4_da_get_block_prep) the caller of
162  * ext4_map_blocks wants to know whether or not the underlying cluster has
163  * already been accounted for. EXT4_MAP_FROM_CLUSTER conveys to the caller that
164  * the requested mapping was from previously mapped (or delayed allocated)
165  * cluster. We use BH_AllocFromCluster only for this flag. BH_AllocFromCluster
166  * should never appear on buffer_head's state flags.
167  */
168 #define EXT4_MAP_FROM_CLUSTER	(1 << BH_AllocFromCluster)
169 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
170 				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
171 				 EXT4_MAP_UNINIT | EXT4_MAP_FROM_CLUSTER)
172 
173 struct ext4_map_blocks {
174 	ext4_fsblk_t m_pblk;
175 	ext4_lblk_t m_lblk;
176 	unsigned int m_len;
177 	unsigned int m_flags;
178 };
179 
180 /*
181  * Flags for ext4_io_end->flags
182  */
183 #define	EXT4_IO_END_UNWRITTEN	0x0001
184 
185 /*
186  * For converting uninitialized extents on a work queue. 'handle' is used for
187  * buffered writeback.
188  */
189 typedef struct ext4_io_end {
190 	struct list_head	list;		/* per-file finished IO list */
191 	handle_t		*handle;	/* handle reserved for extent
192 						 * conversion */
193 	struct inode		*inode;		/* file being written to */
194 	struct bio		*bio;		/* Linked list of completed
195 						 * bios covering the extent */
196 	unsigned int		flag;		/* unwritten or not */
197 	loff_t			offset;		/* offset in the file */
198 	ssize_t			size;		/* size of the extent */
199 	atomic_t		count;		/* reference counter */
200 } ext4_io_end_t;
201 
202 struct ext4_io_submit {
203 	int			io_op;
204 	struct bio		*io_bio;
205 	ext4_io_end_t		*io_end;
206 	sector_t		io_next_block;
207 };
208 
209 /*
210  * Special inodes numbers
211  */
212 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
213 #define EXT4_ROOT_INO		 2	/* Root inode */
214 #define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
215 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
216 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
217 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
218 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
219 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
220 
221 /* First non-reserved inode for old ext4 filesystems */
222 #define EXT4_GOOD_OLD_FIRST_INO	11
223 
224 /*
225  * Maximal count of links to a file
226  */
227 #define EXT4_LINK_MAX		65000
228 
229 /*
230  * Macro-instructions used to manage several block sizes
231  */
232 #define EXT4_MIN_BLOCK_SIZE		1024
233 #define	EXT4_MAX_BLOCK_SIZE		65536
234 #define EXT4_MIN_BLOCK_LOG_SIZE		10
235 #define EXT4_MAX_BLOCK_LOG_SIZE		16
236 #ifdef __KERNEL__
237 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
238 #else
239 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
240 #endif
241 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
242 #define EXT4_CLUSTER_SIZE(s)		(EXT4_BLOCK_SIZE(s) << \
243 					 EXT4_SB(s)->s_cluster_bits)
244 #ifdef __KERNEL__
245 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
246 # define EXT4_CLUSTER_BITS(s)		(EXT4_SB(s)->s_cluster_bits)
247 #else
248 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
249 #endif
250 #ifdef __KERNEL__
251 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
252 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
253 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
254 #else
255 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
256 				 EXT4_GOOD_OLD_INODE_SIZE : \
257 				 (s)->s_inode_size)
258 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
259 				 EXT4_GOOD_OLD_FIRST_INO : \
260 				 (s)->s_first_ino)
261 #endif
262 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
263 
264 /* Translate a block number to a cluster number */
265 #define EXT4_B2C(sbi, blk)	((blk) >> (sbi)->s_cluster_bits)
266 /* Translate a cluster number to a block number */
267 #define EXT4_C2B(sbi, cluster)	((cluster) << (sbi)->s_cluster_bits)
268 /* Translate # of blks to # of clusters */
269 #define EXT4_NUM_B2C(sbi, blks)	(((blks) + (sbi)->s_cluster_ratio - 1) >> \
270 				 (sbi)->s_cluster_bits)
271 
272 /*
273  * Structure of a blocks group descriptor
274  */
275 struct ext4_group_desc
276 {
277 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
278 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
279 	__le32	bg_inode_table_lo;	/* Inodes table block */
280 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
281 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
282 	__le16	bg_used_dirs_count_lo;	/* Directories count */
283 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
284 	__le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
285 	__le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
286 	__le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
287 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
288 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
289 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
290 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
291 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
292 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
293 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
294 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
295 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
296 	__le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
297 	__le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
298 	__le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
299 	__u32   bg_reserved;
300 };
301 
302 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END	\
303 	(offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
304 	 sizeof(__le16))
305 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END	\
306 	(offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
307 	 sizeof(__le16))
308 
309 /*
310  * Structure of a flex block group info
311  */
312 
313 struct flex_groups {
314 	atomic64_t	free_clusters;
315 	atomic_t	free_inodes;
316 	atomic_t	used_dirs;
317 };
318 
319 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
320 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
321 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
322 
323 /*
324  * Macro-instructions used to manage group descriptors
325  */
326 #define EXT4_MIN_DESC_SIZE		32
327 #define EXT4_MIN_DESC_SIZE_64BIT	64
328 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
329 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
330 #ifdef __KERNEL__
331 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
332 # define EXT4_CLUSTERS_PER_GROUP(s)	(EXT4_SB(s)->s_clusters_per_group)
333 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
334 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
335 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
336 #else
337 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
338 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
339 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
340 #endif
341 
342 /*
343  * Constants relative to the data blocks
344  */
345 #define	EXT4_NDIR_BLOCKS		12
346 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
347 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
348 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
349 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
350 
351 /*
352  * Inode flags
353  */
354 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
355 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
356 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
357 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
358 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
359 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
360 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
361 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
362 /* Reserved for compression usage... */
363 #define EXT4_DIRTY_FL			0x00000100
364 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
365 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
366 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
367 /* End compression flags --- maybe not all used */
368 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
369 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
370 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
371 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
372 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
373 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
374 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
375 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
376 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
377 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
378 #define EXT4_INLINE_DATA_FL		0x10000000 /* Inode has inline data. */
379 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
380 
381 #define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
382 #define EXT4_FL_USER_MODIFIABLE		0x004380FF /* User modifiable flags */
383 
384 /* Flags that should be inherited by new inodes from their parent. */
385 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
386 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
387 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
388 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
389 
390 /* Flags that are appropriate for regular files (all but dir-specific ones). */
391 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
392 
393 /* Flags that are appropriate for non-directories/regular files. */
394 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
395 
396 /* Mask out flags that are inappropriate for the given type of inode. */
397 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
398 {
399 	if (S_ISDIR(mode))
400 		return flags;
401 	else if (S_ISREG(mode))
402 		return flags & EXT4_REG_FLMASK;
403 	else
404 		return flags & EXT4_OTHER_FLMASK;
405 }
406 
407 /*
408  * Inode flags used for atomic set/get
409  */
410 enum {
411 	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
412 	EXT4_INODE_UNRM		= 1,	/* Undelete */
413 	EXT4_INODE_COMPR	= 2,	/* Compress file */
414 	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
415 	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
416 	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
417 	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
418 	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
419 /* Reserved for compression usage... */
420 	EXT4_INODE_DIRTY	= 8,
421 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
422 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
423 	EXT4_INODE_ECOMPR	= 11,	/* Compression error */
424 /* End compression flags --- maybe not all used */
425 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
426 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
427 	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
428 	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
429 	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
430 	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
431 	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
432 	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
433 	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
434 	EXT4_INODE_EOFBLOCKS	= 22,	/* Blocks allocated beyond EOF */
435 	EXT4_INODE_INLINE_DATA	= 28,	/* Data in inode. */
436 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
437 };
438 
439 /*
440  * Since it's pretty easy to mix up bit numbers and hex values, we use a
441  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
442  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
443  * any extra space in the compiled kernel image, otherwise, the build will fail.
444  * It's important that these values are the same, since we are using
445  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
446  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
447  * values found in ext2, ext3 and ext4 filesystems, and of course the values
448  * defined in e2fsprogs.
449  *
450  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
451  */
452 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
453 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
454 
455 static inline void ext4_check_flag_values(void)
456 {
457 	CHECK_FLAG_VALUE(SECRM);
458 	CHECK_FLAG_VALUE(UNRM);
459 	CHECK_FLAG_VALUE(COMPR);
460 	CHECK_FLAG_VALUE(SYNC);
461 	CHECK_FLAG_VALUE(IMMUTABLE);
462 	CHECK_FLAG_VALUE(APPEND);
463 	CHECK_FLAG_VALUE(NODUMP);
464 	CHECK_FLAG_VALUE(NOATIME);
465 	CHECK_FLAG_VALUE(DIRTY);
466 	CHECK_FLAG_VALUE(COMPRBLK);
467 	CHECK_FLAG_VALUE(NOCOMPR);
468 	CHECK_FLAG_VALUE(ECOMPR);
469 	CHECK_FLAG_VALUE(INDEX);
470 	CHECK_FLAG_VALUE(IMAGIC);
471 	CHECK_FLAG_VALUE(JOURNAL_DATA);
472 	CHECK_FLAG_VALUE(NOTAIL);
473 	CHECK_FLAG_VALUE(DIRSYNC);
474 	CHECK_FLAG_VALUE(TOPDIR);
475 	CHECK_FLAG_VALUE(HUGE_FILE);
476 	CHECK_FLAG_VALUE(EXTENTS);
477 	CHECK_FLAG_VALUE(EA_INODE);
478 	CHECK_FLAG_VALUE(EOFBLOCKS);
479 	CHECK_FLAG_VALUE(INLINE_DATA);
480 	CHECK_FLAG_VALUE(RESERVED);
481 }
482 
483 /* Used to pass group descriptor data when online resize is done */
484 struct ext4_new_group_input {
485 	__u32 group;		/* Group number for this data */
486 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
487 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
488 	__u64 inode_table;	/* Absolute block number of inode table start */
489 	__u32 blocks_count;	/* Total number of blocks in this group */
490 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
491 	__u16 unused;
492 };
493 
494 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
495 struct compat_ext4_new_group_input {
496 	u32 group;
497 	compat_u64 block_bitmap;
498 	compat_u64 inode_bitmap;
499 	compat_u64 inode_table;
500 	u32 blocks_count;
501 	u16 reserved_blocks;
502 	u16 unused;
503 };
504 #endif
505 
506 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
507 struct ext4_new_group_data {
508 	__u32 group;
509 	__u64 block_bitmap;
510 	__u64 inode_bitmap;
511 	__u64 inode_table;
512 	__u32 blocks_count;
513 	__u16 reserved_blocks;
514 	__u16 unused;
515 	__u32 free_blocks_count;
516 };
517 
518 /* Indexes used to index group tables in ext4_new_group_data */
519 enum {
520 	BLOCK_BITMAP = 0,	/* block bitmap */
521 	INODE_BITMAP,		/* inode bitmap */
522 	INODE_TABLE,		/* inode tables */
523 	GROUP_TABLE_COUNT,
524 };
525 
526 /*
527  * Flags used by ext4_map_blocks()
528  */
529 	/* Allocate any needed blocks and/or convert an unitialized
530 	   extent to be an initialized ext4 */
531 #define EXT4_GET_BLOCKS_CREATE			0x0001
532 	/* Request the creation of an unitialized extent */
533 #define EXT4_GET_BLOCKS_UNINIT_EXT		0x0002
534 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\
535 						 EXT4_GET_BLOCKS_CREATE)
536 	/* Caller is from the delayed allocation writeout path
537 	 * finally doing the actual allocation of delayed blocks */
538 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
539 	/* caller is from the direct IO path, request to creation of an
540 	unitialized extents if not allocated, split the uninitialized
541 	extent if blocks has been preallocated already*/
542 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
543 #define EXT4_GET_BLOCKS_CONVERT			0x0010
544 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
545 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
546 	/* Convert extent to initialized after IO complete */
547 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
548 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
549 	/* Eventual metadata allocation (due to growing extent tree)
550 	 * should not fail, so try to use reserved blocks for that.*/
551 #define EXT4_GET_BLOCKS_METADATA_NOFAIL		0x0020
552 	/* Don't normalize allocation size (used for fallocate) */
553 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
554 	/* Request will not result in inode size update (user for fallocate) */
555 #define EXT4_GET_BLOCKS_KEEP_SIZE		0x0080
556 	/* Do not take i_data_sem locking in ext4_map_blocks */
557 #define EXT4_GET_BLOCKS_NO_LOCK			0x0100
558 	/* Do not put hole in extent cache */
559 #define EXT4_GET_BLOCKS_NO_PUT_HOLE		0x0200
560 
561 /*
562  * The bit position of these flags must not overlap with any of the
563  * EXT4_GET_BLOCKS_*.  They are used by ext4_ext_find_extent(),
564  * read_extent_tree_block(), ext4_split_extent_at(),
565  * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf().
566  * EXT4_EX_NOCACHE is used to indicate that the we shouldn't be
567  * caching the extents when reading from the extent tree while a
568  * truncate or punch hole operation is in progress.
569  */
570 #define EXT4_EX_NOCACHE				0x0400
571 #define EXT4_EX_FORCE_CACHE			0x0800
572 
573 /*
574  * Flags used by ext4_free_blocks
575  */
576 #define EXT4_FREE_BLOCKS_METADATA	0x0001
577 #define EXT4_FREE_BLOCKS_FORGET		0x0002
578 #define EXT4_FREE_BLOCKS_VALIDATED	0x0004
579 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE	0x0008
580 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
581 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
582 #define EXT4_FREE_BLOCKS_RESERVE		0x0040
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 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
765 		ext4_decode_extra_time(&(einode)->xtime,		       \
766 				       raw_inode->xtime ## _extra);	       \
767 	else								       \
768 		(einode)->xtime.tv_nsec = 0;				       \
769 } while (0)
770 
771 #define i_disk_version osd1.linux1.l_i_version
772 
773 #if defined(__KERNEL__) || defined(__linux__)
774 #define i_reserved1	osd1.linux1.l_i_reserved1
775 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
776 #define i_blocks_high	osd2.linux2.l_i_blocks_high
777 #define i_uid_low	i_uid
778 #define i_gid_low	i_gid
779 #define i_uid_high	osd2.linux2.l_i_uid_high
780 #define i_gid_high	osd2.linux2.l_i_gid_high
781 #define i_checksum_lo	osd2.linux2.l_i_checksum_lo
782 
783 #elif defined(__GNU__)
784 
785 #define i_translator	osd1.hurd1.h_i_translator
786 #define i_uid_high	osd2.hurd2.h_i_uid_high
787 #define i_gid_high	osd2.hurd2.h_i_gid_high
788 #define i_author	osd2.hurd2.h_i_author
789 
790 #elif defined(__masix__)
791 
792 #define i_reserved1	osd1.masix1.m_i_reserved1
793 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
794 #define i_reserved2	osd2.masix2.m_i_reserved2
795 
796 #endif /* defined(__KERNEL__) || defined(__linux__) */
797 
798 #include "extents_status.h"
799 
800 /*
801  * fourth extended file system inode data in memory
802  */
803 struct ext4_inode_info {
804 	__le32	i_data[15];	/* unconverted */
805 	__u32	i_dtime;
806 	ext4_fsblk_t	i_file_acl;
807 
808 	/*
809 	 * i_block_group is the number of the block group which contains
810 	 * this file's inode.  Constant across the lifetime of the inode,
811 	 * it is ued for making block allocation decisions - we try to
812 	 * place a file's data blocks near its inode block, and new inodes
813 	 * near to their parent directory's inode.
814 	 */
815 	ext4_group_t	i_block_group;
816 	ext4_lblk_t	i_dir_start_lookup;
817 #if (BITS_PER_LONG < 64)
818 	unsigned long	i_state_flags;		/* Dynamic state flags */
819 #endif
820 	unsigned long	i_flags;
821 
822 	/*
823 	 * Extended attributes can be read independently of the main file
824 	 * data. Taking i_mutex even when reading would cause contention
825 	 * between readers of EAs and writers of regular file data, so
826 	 * instead we synchronize on xattr_sem when reading or changing
827 	 * EAs.
828 	 */
829 	struct rw_semaphore xattr_sem;
830 
831 	struct list_head i_orphan;	/* unlinked but open inodes */
832 
833 	/*
834 	 * i_disksize keeps track of what the inode size is ON DISK, not
835 	 * in memory.  During truncate, i_size is set to the new size by
836 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
837 	 * set i_disksize to 0 until the truncate is actually under way.
838 	 *
839 	 * The intent is that i_disksize always represents the blocks which
840 	 * are used by this file.  This allows recovery to restart truncate
841 	 * on orphans if we crash during truncate.  We actually write i_disksize
842 	 * into the on-disk inode when writing inodes out, instead of i_size.
843 	 *
844 	 * The only time when i_disksize and i_size may be different is when
845 	 * a truncate is in progress.  The only things which change i_disksize
846 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
847 	 */
848 	loff_t	i_disksize;
849 
850 	/*
851 	 * i_data_sem is for serialising ext4_truncate() against
852 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
853 	 * data tree are chopped off during truncate. We can't do that in
854 	 * ext4 because whenever we perform intermediate commits during
855 	 * truncate, the inode and all the metadata blocks *must* be in a
856 	 * consistent state which allows truncation of the orphans to restart
857 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
858 	 * by other means, so we have i_data_sem.
859 	 */
860 	struct rw_semaphore i_data_sem;
861 	struct inode vfs_inode;
862 	struct jbd2_inode *jinode;
863 
864 	/*
865 	 * File creation time. Its function is same as that of
866 	 * struct timespec i_{a,c,m}time in the generic inode.
867 	 */
868 	struct timespec i_crtime;
869 
870 	/* mballoc */
871 	struct list_head i_prealloc_list;
872 	spinlock_t i_prealloc_lock;
873 
874 	/* extents status tree */
875 	struct ext4_es_tree i_es_tree;
876 	rwlock_t i_es_lock;
877 	struct list_head i_es_lru;
878 	unsigned int i_es_lru_nr;	/* protected by i_es_lock */
879 	unsigned long i_touch_when;	/* jiffies of last accessing */
880 
881 	/* ialloc */
882 	ext4_group_t	i_last_alloc_group;
883 
884 	/* allocation reservation info for delalloc */
885 	/* In case of bigalloc, these refer to clusters rather than blocks */
886 	unsigned int i_reserved_data_blocks;
887 	unsigned int i_reserved_meta_blocks;
888 	unsigned int i_allocated_meta_blocks;
889 	ext4_lblk_t i_da_metadata_calc_last_lblock;
890 	int i_da_metadata_calc_len;
891 
892 	/* on-disk additional length */
893 	__u16 i_extra_isize;
894 
895 	/* Indicate the inline data space. */
896 	u16 i_inline_off;
897 	u16 i_inline_size;
898 
899 #ifdef CONFIG_QUOTA
900 	/* quota space reservation, managed internally by quota code */
901 	qsize_t i_reserved_quota;
902 #endif
903 
904 	/* Lock protecting lists below */
905 	spinlock_t i_completed_io_lock;
906 	/*
907 	 * Completed IOs that need unwritten extents handling and have
908 	 * transaction reserved
909 	 */
910 	struct list_head i_rsv_conversion_list;
911 	/*
912 	 * Completed IOs that need unwritten extents handling and don't have
913 	 * transaction reserved
914 	 */
915 	atomic_t i_ioend_count;	/* Number of outstanding io_end structs */
916 	atomic_t i_unwritten; /* Nr. of inflight conversions pending */
917 	struct work_struct i_rsv_conversion_work;
918 
919 	spinlock_t i_block_reservation_lock;
920 
921 	/*
922 	 * Transactions that contain inode's metadata needed to complete
923 	 * fsync and fdatasync, respectively.
924 	 */
925 	tid_t i_sync_tid;
926 	tid_t i_datasync_tid;
927 
928 	/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
929 	__u32 i_csum_seed;
930 };
931 
932 /*
933  * File system states
934  */
935 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
936 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
937 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
938 
939 /*
940  * Misc. filesystem flags
941  */
942 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
943 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
944 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
945 
946 /*
947  * Mount flags set via mount options or defaults
948  */
949 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
950 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
951 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
952 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
953 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
954 #define EXT4_MOUNT_ERRORS_MASK		0x00070
955 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
956 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
957 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
958 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
959 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
960 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
961 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
962 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
963 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
964 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
965 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
966 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
967 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
968 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
969 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
970 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
971 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
972 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
973 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
974 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
975 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
976 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
977 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
978 
979 /*
980  * Mount flags set either automatically (could not be set by mount option)
981  * based on per file system feature or property or in special cases such as
982  * distinguishing between explicit mount option definition and default.
983  */
984 #define EXT4_MOUNT2_EXPLICIT_DELALLOC	0x00000001 /* User explicitly
985 						      specified delalloc */
986 #define EXT4_MOUNT2_STD_GROUP_SIZE	0x00000002 /* We have standard group
987 						      size of blocksize * 8
988 						      blocks */
989 
990 #define clear_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt &= \
991 						~EXT4_MOUNT_##opt
992 #define set_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt |= \
993 						EXT4_MOUNT_##opt
994 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
995 					 EXT4_MOUNT_##opt)
996 
997 #define clear_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 &= \
998 						~EXT4_MOUNT2_##opt
999 #define set_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 |= \
1000 						EXT4_MOUNT2_##opt
1001 #define test_opt2(sb, opt)		(EXT4_SB(sb)->s_mount_opt2 & \
1002 					 EXT4_MOUNT2_##opt)
1003 
1004 #define ext4_test_and_set_bit		__test_and_set_bit_le
1005 #define ext4_set_bit			__set_bit_le
1006 #define ext4_set_bit_atomic		ext2_set_bit_atomic
1007 #define ext4_test_and_clear_bit		__test_and_clear_bit_le
1008 #define ext4_clear_bit			__clear_bit_le
1009 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
1010 #define ext4_test_bit			test_bit_le
1011 #define ext4_find_next_zero_bit		find_next_zero_bit_le
1012 #define ext4_find_next_bit		find_next_bit_le
1013 
1014 extern void ext4_set_bits(void *bm, int cur, int len);
1015 
1016 /*
1017  * Maximal mount counts between two filesystem checks
1018  */
1019 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
1020 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
1021 
1022 /*
1023  * Behaviour when detecting errors
1024  */
1025 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
1026 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
1027 #define EXT4_ERRORS_PANIC		3	/* Panic */
1028 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
1029 
1030 /* Metadata checksum algorithm codes */
1031 #define EXT4_CRC32C_CHKSUM		1
1032 
1033 /*
1034  * Structure of the super block
1035  */
1036 struct ext4_super_block {
1037 /*00*/	__le32	s_inodes_count;		/* Inodes count */
1038 	__le32	s_blocks_count_lo;	/* Blocks count */
1039 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
1040 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
1041 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
1042 	__le32	s_first_data_block;	/* First Data Block */
1043 	__le32	s_log_block_size;	/* Block size */
1044 	__le32	s_log_cluster_size;	/* Allocation cluster size */
1045 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
1046 	__le32	s_clusters_per_group;	/* # Clusters per group */
1047 	__le32	s_inodes_per_group;	/* # Inodes per group */
1048 	__le32	s_mtime;		/* Mount time */
1049 /*30*/	__le32	s_wtime;		/* Write time */
1050 	__le16	s_mnt_count;		/* Mount count */
1051 	__le16	s_max_mnt_count;	/* Maximal mount count */
1052 	__le16	s_magic;		/* Magic signature */
1053 	__le16	s_state;		/* File system state */
1054 	__le16	s_errors;		/* Behaviour when detecting errors */
1055 	__le16	s_minor_rev_level;	/* minor revision level */
1056 /*40*/	__le32	s_lastcheck;		/* time of last check */
1057 	__le32	s_checkinterval;	/* max. time between checks */
1058 	__le32	s_creator_os;		/* OS */
1059 	__le32	s_rev_level;		/* Revision level */
1060 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
1061 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
1062 	/*
1063 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
1064 	 *
1065 	 * Note: the difference between the compatible feature set and
1066 	 * the incompatible feature set is that if there is a bit set
1067 	 * in the incompatible feature set that the kernel doesn't
1068 	 * know about, it should refuse to mount the filesystem.
1069 	 *
1070 	 * e2fsck's requirements are more strict; if it doesn't know
1071 	 * about a feature in either the compatible or incompatible
1072 	 * feature set, it must abort and not try to meddle with
1073 	 * things it doesn't understand...
1074 	 */
1075 	__le32	s_first_ino;		/* First non-reserved inode */
1076 	__le16  s_inode_size;		/* size of inode structure */
1077 	__le16	s_block_group_nr;	/* block group # of this superblock */
1078 	__le32	s_feature_compat;	/* compatible feature set */
1079 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
1080 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
1081 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
1082 /*78*/	char	s_volume_name[16];	/* volume name */
1083 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
1084 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
1085 	/*
1086 	 * Performance hints.  Directory preallocation should only
1087 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1088 	 */
1089 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
1090 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
1091 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
1092 	/*
1093 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1094 	 */
1095 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
1096 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
1097 	__le32	s_journal_dev;		/* device number of journal file */
1098 	__le32	s_last_orphan;		/* start of list of inodes to delete */
1099 	__le32	s_hash_seed[4];		/* HTREE hash seed */
1100 	__u8	s_def_hash_version;	/* Default hash version to use */
1101 	__u8	s_jnl_backup_type;
1102 	__le16  s_desc_size;		/* size of group descriptor */
1103 /*100*/	__le32	s_default_mount_opts;
1104 	__le32	s_first_meta_bg;	/* First metablock block group */
1105 	__le32	s_mkfs_time;		/* When the filesystem was created */
1106 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
1107 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1108 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
1109 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
1110 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
1111 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
1112 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
1113 	__le32	s_flags;		/* Miscellaneous flags */
1114 	__le16  s_raid_stride;		/* RAID stride */
1115 	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1116 	__le64  s_mmp_block;            /* Block for multi-mount protection */
1117 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1118 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
1119 	__u8	s_checksum_type;	/* metadata checksum algorithm used */
1120 	__le16  s_reserved_pad;
1121 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1122 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
1123 	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
1124 	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
1125 					      snapshot's future use */
1126 	__le32	s_snapshot_list;	/* inode number of the head of the
1127 					   on-disk snapshot list */
1128 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1129 	__le32	s_error_count;		/* number of fs errors */
1130 	__le32	s_first_error_time;	/* first time an error happened */
1131 	__le32	s_first_error_ino;	/* inode involved in first error */
1132 	__le64	s_first_error_block;	/* block involved of first error */
1133 	__u8	s_first_error_func[32];	/* function where the error happened */
1134 	__le32	s_first_error_line;	/* line number where error happened */
1135 	__le32	s_last_error_time;	/* most recent time of an error */
1136 	__le32	s_last_error_ino;	/* inode involved in last error */
1137 	__le32	s_last_error_line;	/* line number where error happened */
1138 	__le64	s_last_error_block;	/* block involved of last error */
1139 	__u8	s_last_error_func[32];	/* function where the error happened */
1140 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1141 	__u8	s_mount_opts[64];
1142 	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
1143 	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
1144 	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
1145 	__le32	s_reserved[108];	/* Padding to the end of the block */
1146 	__le32	s_checksum;		/* crc32c(superblock) */
1147 };
1148 
1149 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1150 
1151 #ifdef __KERNEL__
1152 
1153 /*
1154  * run-time mount flags
1155  */
1156 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
1157 #define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
1158 
1159 /*
1160  * fourth extended-fs super-block data in memory
1161  */
1162 struct ext4_sb_info {
1163 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
1164 	unsigned long s_inodes_per_block;/* Number of inodes per block */
1165 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
1166 	unsigned long s_clusters_per_group; /* Number of clusters in a group */
1167 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
1168 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
1169 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
1170 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
1171 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1172 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1173 	unsigned long s_overhead;  /* # of fs overhead clusters */
1174 	unsigned int s_cluster_ratio;	/* Number of blocks per cluster */
1175 	unsigned int s_cluster_bits;	/* log2 of s_cluster_ratio */
1176 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
1177 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
1178 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
1179 	struct buffer_head **s_group_desc;
1180 	unsigned int s_mount_opt;
1181 	unsigned int s_mount_opt2;
1182 	unsigned int s_mount_flags;
1183 	unsigned int s_def_mount_opt;
1184 	ext4_fsblk_t s_sb_block;
1185 	atomic64_t s_resv_clusters;
1186 	kuid_t s_resuid;
1187 	kgid_t s_resgid;
1188 	unsigned short s_mount_state;
1189 	unsigned short s_pad;
1190 	int s_addr_per_block_bits;
1191 	int s_desc_per_block_bits;
1192 	int s_inode_size;
1193 	int s_first_ino;
1194 	unsigned int s_inode_readahead_blks;
1195 	unsigned int s_inode_goal;
1196 	spinlock_t s_next_gen_lock;
1197 	u32 s_next_generation;
1198 	u32 s_hash_seed[4];
1199 	int s_def_hash_version;
1200 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
1201 	struct percpu_counter s_freeclusters_counter;
1202 	struct percpu_counter s_freeinodes_counter;
1203 	struct percpu_counter s_dirs_counter;
1204 	struct percpu_counter s_dirtyclusters_counter;
1205 	struct blockgroup_lock *s_blockgroup_lock;
1206 	struct proc_dir_entry *s_proc;
1207 	struct kobject s_kobj;
1208 	struct completion s_kobj_unregister;
1209 	struct super_block *s_sb;
1210 
1211 	/* Journaling */
1212 	struct journal_s *s_journal;
1213 	struct list_head s_orphan;
1214 	struct mutex s_orphan_lock;
1215 	unsigned long s_resize_flags;		/* Flags indicating if there
1216 						   is a resizer */
1217 	unsigned long s_commit_interval;
1218 	u32 s_max_batch_time;
1219 	u32 s_min_batch_time;
1220 	struct block_device *journal_bdev;
1221 #ifdef CONFIG_QUOTA
1222 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
1223 	int s_jquota_fmt;			/* Format of quota to use */
1224 #endif
1225 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1226 	struct rb_root system_blks;
1227 
1228 #ifdef EXTENTS_STATS
1229 	/* ext4 extents stats */
1230 	unsigned long s_ext_min;
1231 	unsigned long s_ext_max;
1232 	unsigned long s_depth_max;
1233 	spinlock_t s_ext_stats_lock;
1234 	unsigned long s_ext_blocks;
1235 	unsigned long s_ext_extents;
1236 #endif
1237 
1238 	/* for buddy allocator */
1239 	struct ext4_group_info ***s_group_info;
1240 	struct inode *s_buddy_cache;
1241 	spinlock_t s_md_lock;
1242 	unsigned short *s_mb_offsets;
1243 	unsigned int *s_mb_maxs;
1244 	unsigned int s_group_info_size;
1245 
1246 	/* tunables */
1247 	unsigned long s_stripe;
1248 	unsigned int s_mb_stream_request;
1249 	unsigned int s_mb_max_to_scan;
1250 	unsigned int s_mb_min_to_scan;
1251 	unsigned int s_mb_stats;
1252 	unsigned int s_mb_order2_reqs;
1253 	unsigned int s_mb_group_prealloc;
1254 	unsigned int s_max_dir_size_kb;
1255 	/* where last allocation was done - for stream allocation */
1256 	unsigned long s_mb_last_group;
1257 	unsigned long s_mb_last_start;
1258 
1259 	/* stats for buddy allocator */
1260 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1261 	atomic_t s_bal_success;	/* we found long enough chunks */
1262 	atomic_t s_bal_allocated;	/* in blocks */
1263 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1264 	atomic_t s_bal_goals;	/* goal hits */
1265 	atomic_t s_bal_breaks;	/* too long searches */
1266 	atomic_t s_bal_2orders;	/* 2^order hits */
1267 	spinlock_t s_bal_lock;
1268 	unsigned long s_mb_buddies_generated;
1269 	unsigned long long s_mb_generation_time;
1270 	atomic_t s_mb_lost_chunks;
1271 	atomic_t s_mb_preallocated;
1272 	atomic_t s_mb_discarded;
1273 	atomic_t s_lock_busy;
1274 
1275 	/* locality groups */
1276 	struct ext4_locality_group __percpu *s_locality_groups;
1277 
1278 	/* for write statistics */
1279 	unsigned long s_sectors_written_start;
1280 	u64 s_kbytes_written;
1281 
1282 	/* the size of zero-out chunk */
1283 	unsigned int s_extent_max_zeroout_kb;
1284 
1285 	unsigned int s_log_groups_per_flex;
1286 	struct flex_groups *s_flex_groups;
1287 	ext4_group_t s_flex_groups_allocated;
1288 
1289 	/* workqueue for reserved extent conversions (buffered io) */
1290 	struct workqueue_struct *rsv_conversion_wq;
1291 
1292 	/* timer for periodic error stats printing */
1293 	struct timer_list s_err_report;
1294 
1295 	/* Lazy inode table initialization info */
1296 	struct ext4_li_request *s_li_request;
1297 	/* Wait multiplier for lazy initialization thread */
1298 	unsigned int s_li_wait_mult;
1299 
1300 	/* Kernel thread for multiple mount protection */
1301 	struct task_struct *s_mmp_tsk;
1302 
1303 	/* record the last minlen when FITRIM is called. */
1304 	atomic_t s_last_trim_minblks;
1305 
1306 	/* Reference to checksum algorithm driver via cryptoapi */
1307 	struct crypto_shash *s_chksum_driver;
1308 
1309 	/* Precomputed FS UUID checksum for seeding other checksums */
1310 	__u32 s_csum_seed;
1311 
1312 	/* Reclaim extents from extent status tree */
1313 	struct shrinker s_es_shrinker;
1314 	struct list_head s_es_lru;
1315 	unsigned long s_es_last_sorted;
1316 	struct percpu_counter s_extent_cache_cnt;
1317 	spinlock_t s_es_lru_lock ____cacheline_aligned_in_smp;
1318 
1319 	/* Ratelimit ext4 messages. */
1320 	struct ratelimit_state s_err_ratelimit_state;
1321 	struct ratelimit_state s_warning_ratelimit_state;
1322 	struct ratelimit_state s_msg_ratelimit_state;
1323 };
1324 
1325 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1326 {
1327 	return sb->s_fs_info;
1328 }
1329 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1330 {
1331 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1332 }
1333 
1334 static inline struct timespec ext4_current_time(struct inode *inode)
1335 {
1336 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1337 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1338 }
1339 
1340 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1341 {
1342 	return ino == EXT4_ROOT_INO ||
1343 		ino == EXT4_USR_QUOTA_INO ||
1344 		ino == EXT4_GRP_QUOTA_INO ||
1345 		ino == EXT4_BOOT_LOADER_INO ||
1346 		ino == EXT4_JOURNAL_INO ||
1347 		ino == EXT4_RESIZE_INO ||
1348 		(ino >= EXT4_FIRST_INO(sb) &&
1349 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1350 }
1351 
1352 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1353 					      struct ext4_io_end *io_end)
1354 {
1355 	if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1356 		io_end->flag |= EXT4_IO_END_UNWRITTEN;
1357 		atomic_inc(&EXT4_I(inode)->i_unwritten);
1358 	}
1359 }
1360 
1361 static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode)
1362 {
1363 	return inode->i_private;
1364 }
1365 
1366 static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io)
1367 {
1368 	inode->i_private = io;
1369 }
1370 
1371 /*
1372  * Inode dynamic state flags
1373  */
1374 enum {
1375 	EXT4_STATE_JDATA,		/* journaled data exists */
1376 	EXT4_STATE_NEW,			/* inode is newly created */
1377 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1378 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1379 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1380 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1381 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1382 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1383 	EXT4_STATE_DELALLOC_RESERVED,	/* blks already reserved for delalloc */
1384 	EXT4_STATE_DIOREAD_LOCK,	/* Disable support for dio read
1385 					   nolocking */
1386 	EXT4_STATE_MAY_INLINE_DATA,	/* may have in-inode data */
1387 	EXT4_STATE_ORDERED_MODE,	/* data=ordered mode */
1388 	EXT4_STATE_EXT_PRECACHED,	/* extents have been precached */
1389 };
1390 
1391 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
1392 static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
1393 {									\
1394 	return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);	\
1395 }									\
1396 static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
1397 {									\
1398 	set_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1399 }									\
1400 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1401 {									\
1402 	clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1403 }
1404 
1405 /* Add these declarations here only so that these functions can be
1406  * found by name.  Otherwise, they are very hard to locate. */
1407 static inline int ext4_test_inode_flag(struct inode *inode, int bit);
1408 static inline void ext4_set_inode_flag(struct inode *inode, int bit);
1409 static inline void ext4_clear_inode_flag(struct inode *inode, int bit);
1410 EXT4_INODE_BIT_FNS(flag, flags, 0)
1411 
1412 /* Add these declarations here only so that these functions can be
1413  * found by name.  Otherwise, they are very hard to locate. */
1414 static inline int ext4_test_inode_state(struct inode *inode, int bit);
1415 static inline void ext4_set_inode_state(struct inode *inode, int bit);
1416 static inline void ext4_clear_inode_state(struct inode *inode, int bit);
1417 #if (BITS_PER_LONG < 64)
1418 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1419 
1420 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1421 {
1422 	(ei)->i_state_flags = 0;
1423 }
1424 #else
1425 EXT4_INODE_BIT_FNS(state, flags, 32)
1426 
1427 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1428 {
1429 	/* We depend on the fact that callers will set i_flags */
1430 }
1431 #endif
1432 #else
1433 /* Assume that user mode programs are passing in an ext4fs superblock, not
1434  * a kernel struct super_block.  This will allow us to call the feature-test
1435  * macros from user land. */
1436 #define EXT4_SB(sb)	(sb)
1437 #endif
1438 
1439 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1440 
1441 /*
1442  * Codes for operating systems
1443  */
1444 #define EXT4_OS_LINUX		0
1445 #define EXT4_OS_HURD		1
1446 #define EXT4_OS_MASIX		2
1447 #define EXT4_OS_FREEBSD		3
1448 #define EXT4_OS_LITES		4
1449 
1450 /*
1451  * Revision levels
1452  */
1453 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1454 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1455 
1456 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1457 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1458 
1459 #define EXT4_GOOD_OLD_INODE_SIZE 128
1460 
1461 /*
1462  * Feature set definitions
1463  */
1464 
1465 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1466 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1467 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1468 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1469 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1470 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1471 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1472 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1473 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1474 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1475 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1476 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1477 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1478 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1479 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1480 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1481 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1482 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1483 
1484 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1485 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1486 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1487 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1488 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1489 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1490 
1491 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1492 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1493 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1494 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1495 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1496 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1497 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1498 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
1499 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
1500 /*
1501  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1502  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1503  * all other data structures' checksums.  However, the METADATA_CSUM and
1504  * GDT_CSUM bits are mutually exclusive.
1505  */
1506 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
1507 
1508 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1509 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1510 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1511 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1512 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1513 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1514 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1515 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1516 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1517 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1518 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1519 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM	0x2000 /* use crc32c for bg */
1520 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
1521 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA	0x8000 /* data in inode */
1522 
1523 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1524 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1525 					 EXT4_FEATURE_INCOMPAT_META_BG)
1526 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1527 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1528 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1529 
1530 #define EXT3_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1531 #define EXT3_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1532 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1533 					 EXT4_FEATURE_INCOMPAT_META_BG)
1534 #define EXT3_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1535 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1536 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1537 
1538 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1539 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1540 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1541 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1542 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1543 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1544 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1545 					 EXT4_FEATURE_INCOMPAT_MMP |	\
1546 					 EXT4_FEATURE_INCOMPAT_INLINE_DATA)
1547 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1548 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1549 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1550 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1551 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1552 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1553 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1554 					 EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1555 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1556 					 EXT4_FEATURE_RO_COMPAT_QUOTA)
1557 
1558 /*
1559  * Default values for user and/or group using reserved blocks
1560  */
1561 #define	EXT4_DEF_RESUID		0
1562 #define	EXT4_DEF_RESGID		0
1563 
1564 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1565 
1566 /*
1567  * Default mount options
1568  */
1569 #define EXT4_DEFM_DEBUG		0x0001
1570 #define EXT4_DEFM_BSDGROUPS	0x0002
1571 #define EXT4_DEFM_XATTR_USER	0x0004
1572 #define EXT4_DEFM_ACL		0x0008
1573 #define EXT4_DEFM_UID16		0x0010
1574 #define EXT4_DEFM_JMODE		0x0060
1575 #define EXT4_DEFM_JMODE_DATA	0x0020
1576 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1577 #define EXT4_DEFM_JMODE_WBACK	0x0060
1578 #define EXT4_DEFM_NOBARRIER	0x0100
1579 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1580 #define EXT4_DEFM_DISCARD	0x0400
1581 #define EXT4_DEFM_NODELALLOC	0x0800
1582 
1583 /*
1584  * Default journal batch times
1585  */
1586 #define EXT4_DEF_MIN_BATCH_TIME	0
1587 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1588 
1589 /*
1590  * Minimum number of groups in a flexgroup before we separate out
1591  * directories into the first block group of a flexgroup
1592  */
1593 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1594 
1595 /*
1596  * Structure of a directory entry
1597  */
1598 #define EXT4_NAME_LEN 255
1599 
1600 struct ext4_dir_entry {
1601 	__le32	inode;			/* Inode number */
1602 	__le16	rec_len;		/* Directory entry length */
1603 	__le16	name_len;		/* Name length */
1604 	char	name[EXT4_NAME_LEN];	/* File name */
1605 };
1606 
1607 /*
1608  * The new version of the directory entry.  Since EXT4 structures are
1609  * stored in intel byte order, and the name_len field could never be
1610  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1611  * file_type field.
1612  */
1613 struct ext4_dir_entry_2 {
1614 	__le32	inode;			/* Inode number */
1615 	__le16	rec_len;		/* Directory entry length */
1616 	__u8	name_len;		/* Name length */
1617 	__u8	file_type;
1618 	char	name[EXT4_NAME_LEN];	/* File name */
1619 };
1620 
1621 /*
1622  * This is a bogus directory entry at the end of each leaf block that
1623  * records checksums.
1624  */
1625 struct ext4_dir_entry_tail {
1626 	__le32	det_reserved_zero1;	/* Pretend to be unused */
1627 	__le16	det_rec_len;		/* 12 */
1628 	__u8	det_reserved_zero2;	/* Zero name length */
1629 	__u8	det_reserved_ft;	/* 0xDE, fake file type */
1630 	__le32	det_checksum;		/* crc32c(uuid+inum+dirblock) */
1631 };
1632 
1633 #define EXT4_DIRENT_TAIL(block, blocksize) \
1634 	((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1635 					((blocksize) - \
1636 					 sizeof(struct ext4_dir_entry_tail))))
1637 
1638 /*
1639  * Ext4 directory file types.  Only the low 3 bits are used.  The
1640  * other bits are reserved for now.
1641  */
1642 #define EXT4_FT_UNKNOWN		0
1643 #define EXT4_FT_REG_FILE	1
1644 #define EXT4_FT_DIR		2
1645 #define EXT4_FT_CHRDEV		3
1646 #define EXT4_FT_BLKDEV		4
1647 #define EXT4_FT_FIFO		5
1648 #define EXT4_FT_SOCK		6
1649 #define EXT4_FT_SYMLINK		7
1650 
1651 #define EXT4_FT_MAX		8
1652 
1653 #define EXT4_FT_DIR_CSUM	0xDE
1654 
1655 /*
1656  * EXT4_DIR_PAD defines the directory entries boundaries
1657  *
1658  * NOTE: It must be a multiple of 4
1659  */
1660 #define EXT4_DIR_PAD			4
1661 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1662 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1663 					 ~EXT4_DIR_ROUND)
1664 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1665 
1666 /*
1667  * If we ever get support for fs block sizes > page_size, we'll need
1668  * to remove the #if statements in the next two functions...
1669  */
1670 static inline unsigned int
1671 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1672 {
1673 	unsigned len = le16_to_cpu(dlen);
1674 
1675 #if (PAGE_CACHE_SIZE >= 65536)
1676 	if (len == EXT4_MAX_REC_LEN || len == 0)
1677 		return blocksize;
1678 	return (len & 65532) | ((len & 3) << 16);
1679 #else
1680 	return len;
1681 #endif
1682 }
1683 
1684 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1685 {
1686 	if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1687 		BUG();
1688 #if (PAGE_CACHE_SIZE >= 65536)
1689 	if (len < 65536)
1690 		return cpu_to_le16(len);
1691 	if (len == blocksize) {
1692 		if (blocksize == 65536)
1693 			return cpu_to_le16(EXT4_MAX_REC_LEN);
1694 		else
1695 			return cpu_to_le16(0);
1696 	}
1697 	return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1698 #else
1699 	return cpu_to_le16(len);
1700 #endif
1701 }
1702 
1703 /*
1704  * Hash Tree Directory indexing
1705  * (c) Daniel Phillips, 2001
1706  */
1707 
1708 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1709 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1710 		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1711 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1712 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1713 
1714 /* Legal values for the dx_root hash_version field: */
1715 
1716 #define DX_HASH_LEGACY		0
1717 #define DX_HASH_HALF_MD4	1
1718 #define DX_HASH_TEA		2
1719 #define DX_HASH_LEGACY_UNSIGNED	3
1720 #define DX_HASH_HALF_MD4_UNSIGNED	4
1721 #define DX_HASH_TEA_UNSIGNED		5
1722 
1723 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1724 			      const void *address, unsigned int length)
1725 {
1726 	struct {
1727 		struct shash_desc shash;
1728 		char ctx[4];
1729 	} desc;
1730 	int err;
1731 
1732 	BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
1733 
1734 	desc.shash.tfm = sbi->s_chksum_driver;
1735 	desc.shash.flags = 0;
1736 	*(u32 *)desc.ctx = crc;
1737 
1738 	err = crypto_shash_update(&desc.shash, address, length);
1739 	BUG_ON(err);
1740 
1741 	return *(u32 *)desc.ctx;
1742 }
1743 
1744 #ifdef __KERNEL__
1745 
1746 /* hash info structure used by the directory hash */
1747 struct dx_hash_info
1748 {
1749 	u32		hash;
1750 	u32		minor_hash;
1751 	int		hash_version;
1752 	u32		*seed;
1753 };
1754 
1755 
1756 /* 32 and 64 bit signed EOF for dx directories */
1757 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
1758 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
1759 
1760 
1761 /*
1762  * Control parameters used by ext4_htree_next_block
1763  */
1764 #define HASH_NB_ALWAYS		1
1765 
1766 
1767 /*
1768  * Describe an inode's exact location on disk and in memory
1769  */
1770 struct ext4_iloc
1771 {
1772 	struct buffer_head *bh;
1773 	unsigned long offset;
1774 	ext4_group_t block_group;
1775 };
1776 
1777 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1778 {
1779 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1780 }
1781 
1782 /*
1783  * This structure is stuffed into the struct file's private_data field
1784  * for directories.  It is where we put information so that we can do
1785  * readdir operations in hash tree order.
1786  */
1787 struct dir_private_info {
1788 	struct rb_root	root;
1789 	struct rb_node	*curr_node;
1790 	struct fname	*extra_fname;
1791 	loff_t		last_pos;
1792 	__u32		curr_hash;
1793 	__u32		curr_minor_hash;
1794 	__u32		next_hash;
1795 };
1796 
1797 /* calculate the first block number of the group */
1798 static inline ext4_fsblk_t
1799 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1800 {
1801 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1802 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1803 }
1804 
1805 /*
1806  * Special error return code only used by dx_probe() and its callers.
1807  */
1808 #define ERR_BAD_DX_DIR	-75000
1809 
1810 /*
1811  * Timeout and state flag for lazy initialization inode thread.
1812  */
1813 #define EXT4_DEF_LI_WAIT_MULT			10
1814 #define EXT4_DEF_LI_MAX_START_DELAY		5
1815 #define EXT4_LAZYINIT_QUIT			0x0001
1816 #define EXT4_LAZYINIT_RUNNING			0x0002
1817 
1818 /*
1819  * Lazy inode table initialization info
1820  */
1821 struct ext4_lazy_init {
1822 	unsigned long		li_state;
1823 	struct list_head	li_request_list;
1824 	struct mutex		li_list_mtx;
1825 };
1826 
1827 struct ext4_li_request {
1828 	struct super_block	*lr_super;
1829 	struct ext4_sb_info	*lr_sbi;
1830 	ext4_group_t		lr_next_group;
1831 	struct list_head	lr_request;
1832 	unsigned long		lr_next_sched;
1833 	unsigned long		lr_timeout;
1834 };
1835 
1836 struct ext4_features {
1837 	struct kobject f_kobj;
1838 	struct completion f_kobj_unregister;
1839 };
1840 
1841 /*
1842  * This structure will be used for multiple mount protection. It will be
1843  * written into the block number saved in the s_mmp_block field in the
1844  * superblock. Programs that check MMP should assume that if
1845  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1846  * to use the filesystem, regardless of how old the timestamp is.
1847  */
1848 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1849 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1850 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1851 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1852 
1853 struct mmp_struct {
1854 	__le32	mmp_magic;		/* Magic number for MMP */
1855 	__le32	mmp_seq;		/* Sequence no. updated periodically */
1856 
1857 	/*
1858 	 * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1859 	 * purposes and do not affect the correctness of the algorithm
1860 	 */
1861 	__le64	mmp_time;		/* Time last updated */
1862 	char	mmp_nodename[64];	/* Node which last updated MMP block */
1863 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
1864 
1865 	/*
1866 	 * mmp_check_interval is used to verify if the MMP block has been
1867 	 * updated on the block device. The value is updated based on the
1868 	 * maximum time to write the MMP block during an update cycle.
1869 	 */
1870 	__le16	mmp_check_interval;
1871 
1872 	__le16	mmp_pad1;
1873 	__le32	mmp_pad2[226];
1874 	__le32	mmp_checksum;		/* crc32c(uuid+mmp_block) */
1875 };
1876 
1877 /* arguments passed to the mmp thread */
1878 struct mmpd_data {
1879 	struct buffer_head *bh; /* bh from initial read_mmp_block() */
1880 	struct super_block *sb;  /* super block of the fs */
1881 };
1882 
1883 /*
1884  * Check interval multiplier
1885  * The MMP block is written every update interval and initially checked every
1886  * update interval x the multiplier (the value is then adapted based on the
1887  * write latency). The reason is that writes can be delayed under load and we
1888  * don't want readers to incorrectly assume that the filesystem is no longer
1889  * in use.
1890  */
1891 #define EXT4_MMP_CHECK_MULT		2UL
1892 
1893 /*
1894  * Minimum interval for MMP checking in seconds.
1895  */
1896 #define EXT4_MMP_MIN_CHECK_INTERVAL	5UL
1897 
1898 /*
1899  * Maximum interval for MMP checking in seconds.
1900  */
1901 #define EXT4_MMP_MAX_CHECK_INTERVAL	300UL
1902 
1903 /*
1904  * Function prototypes
1905  */
1906 
1907 /*
1908  * Ok, these declarations are also in <linux/kernel.h> but none of the
1909  * ext4 source programs needs to include it so they are duplicated here.
1910  */
1911 # define NORET_TYPE	/**/
1912 # define ATTRIB_NORET	__attribute__((noreturn))
1913 # define NORET_AND	noreturn,
1914 
1915 /* bitmap.c */
1916 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
1917 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1918 				struct ext4_group_desc *gdp,
1919 				struct buffer_head *bh, int sz);
1920 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1921 				  struct ext4_group_desc *gdp,
1922 				  struct buffer_head *bh, int sz);
1923 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1924 				struct ext4_group_desc *gdp,
1925 				struct buffer_head *bh);
1926 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1927 				  struct ext4_group_desc *gdp,
1928 				  struct buffer_head *bh);
1929 
1930 /* balloc.c */
1931 extern void ext4_get_group_no_and_offset(struct super_block *sb,
1932 					 ext4_fsblk_t blocknr,
1933 					 ext4_group_t *blockgrpp,
1934 					 ext4_grpblk_t *offsetp);
1935 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
1936 					  ext4_fsblk_t block);
1937 
1938 extern void ext4_validate_block_bitmap(struct super_block *sb,
1939 				       struct ext4_group_desc *desc,
1940 				       ext4_group_t block_group,
1941 				       struct buffer_head *bh);
1942 extern unsigned int ext4_block_group(struct super_block *sb,
1943 			ext4_fsblk_t blocknr);
1944 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1945 			ext4_fsblk_t blocknr);
1946 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1947 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1948 			ext4_group_t group);
1949 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1950 					 ext4_fsblk_t goal,
1951 					 unsigned int flags,
1952 					 unsigned long *count,
1953 					 int *errp);
1954 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1955 				    s64 nclusters, unsigned int flags);
1956 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1957 extern void ext4_check_blocks_bitmap(struct super_block *);
1958 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1959 						    ext4_group_t block_group,
1960 						    struct buffer_head ** bh);
1961 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1962 
1963 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1964 						ext4_group_t block_group);
1965 extern int ext4_wait_block_bitmap(struct super_block *sb,
1966 				  ext4_group_t block_group,
1967 				  struct buffer_head *bh);
1968 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1969 						  ext4_group_t block_group);
1970 extern void ext4_init_block_bitmap(struct super_block *sb,
1971 				   struct buffer_head *bh,
1972 				   ext4_group_t group,
1973 				   struct ext4_group_desc *desc);
1974 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1975 					      ext4_group_t block_group,
1976 					      struct ext4_group_desc *gdp);
1977 extern unsigned ext4_num_overhead_clusters(struct super_block *sb,
1978 					   ext4_group_t block_group,
1979 					   struct ext4_group_desc *gdp);
1980 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1981 
1982 /* dir.c */
1983 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1984 				  struct file *,
1985 				  struct ext4_dir_entry_2 *,
1986 				  struct buffer_head *, char *, int,
1987 				  unsigned int);
1988 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)	\
1989 	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1990 					(de), (bh), (buf), (size), (offset)))
1991 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1992 				    __u32 minor_hash,
1993 				    struct ext4_dir_entry_2 *dirent);
1994 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1995 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1996 			     struct buffer_head *bh,
1997 			     void *buf, int buf_size,
1998 			     const char *name, int namelen,
1999 			     struct ext4_dir_entry_2 **dest_de);
2000 void ext4_insert_dentry(struct inode *inode,
2001 			struct ext4_dir_entry_2 *de,
2002 			int buf_size,
2003 			const char *name, int namelen);
2004 static inline void ext4_update_dx_flag(struct inode *inode)
2005 {
2006 	if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
2007 				     EXT4_FEATURE_COMPAT_DIR_INDEX))
2008 		ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
2009 }
2010 static unsigned char ext4_filetype_table[] = {
2011 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
2012 };
2013 
2014 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
2015 {
2016 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
2017 	    (filetype >= EXT4_FT_MAX))
2018 		return DT_UNKNOWN;
2019 
2020 	return ext4_filetype_table[filetype];
2021 }
2022 
2023 /* fsync.c */
2024 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2025 
2026 /* hash.c */
2027 extern int ext4fs_dirhash(const char *name, int len, struct
2028 			  dx_hash_info *hinfo);
2029 
2030 /* ialloc.c */
2031 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
2032 				      const struct qstr *qstr, __u32 goal,
2033 				      uid_t *owner, int handle_type,
2034 				      unsigned int line_no, int nblocks);
2035 
2036 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner) \
2037 	__ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
2038 			 0, 0, 0)
2039 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
2040 				    type, nblocks)		    \
2041 	__ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
2042 			 (type), __LINE__, (nblocks))
2043 
2044 
2045 extern void ext4_free_inode(handle_t *, struct inode *);
2046 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2047 extern unsigned long ext4_count_free_inodes(struct super_block *);
2048 extern unsigned long ext4_count_dirs(struct super_block *);
2049 extern void ext4_check_inodes_bitmap(struct super_block *);
2050 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2051 extern int ext4_init_inode_table(struct super_block *sb,
2052 				 ext4_group_t group, int barrier);
2053 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2054 
2055 /* mballoc.c */
2056 extern long ext4_mb_stats;
2057 extern long ext4_mb_max_to_scan;
2058 extern int ext4_mb_init(struct super_block *);
2059 extern int ext4_mb_release(struct super_block *);
2060 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2061 				struct ext4_allocation_request *, int *);
2062 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2063 extern void ext4_discard_preallocations(struct inode *);
2064 extern int __init ext4_init_mballoc(void);
2065 extern void ext4_exit_mballoc(void);
2066 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2067 			     struct buffer_head *bh, ext4_fsblk_t block,
2068 			     unsigned long count, int flags);
2069 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2070 				   ext4_group_t ngroups);
2071 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2072 		ext4_group_t i, struct ext4_group_desc *desc);
2073 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2074 				ext4_fsblk_t block, unsigned long count);
2075 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2076 
2077 /* inode.c */
2078 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
2079 						ext4_lblk_t, int, int *);
2080 struct buffer_head *ext4_bread(handle_t *, struct inode *,
2081 						ext4_lblk_t, int, int *);
2082 int ext4_get_block_write(struct inode *inode, sector_t iblock,
2083 			 struct buffer_head *bh_result, int create);
2084 int ext4_get_block(struct inode *inode, sector_t iblock,
2085 				struct buffer_head *bh_result, int create);
2086 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2087 			   struct buffer_head *bh, int create);
2088 int ext4_walk_page_buffers(handle_t *handle,
2089 			   struct buffer_head *head,
2090 			   unsigned from,
2091 			   unsigned to,
2092 			   int *partial,
2093 			   int (*fn)(handle_t *handle,
2094 				     struct buffer_head *bh));
2095 int do_journal_get_write_access(handle_t *handle,
2096 				struct buffer_head *bh);
2097 #define FALL_BACK_TO_NONDELALLOC 1
2098 #define CONVERT_INLINE_DATA	 2
2099 
2100 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2101 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2102 extern int  ext4_setattr(struct dentry *, struct iattr *);
2103 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
2104 				struct kstat *stat);
2105 extern void ext4_evict_inode(struct inode *);
2106 extern void ext4_clear_inode(struct inode *);
2107 extern int  ext4_sync_inode(handle_t *, struct inode *);
2108 extern void ext4_dirty_inode(struct inode *, int);
2109 extern int ext4_change_inode_journal_flag(struct inode *, int);
2110 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2111 extern int ext4_inode_attach_jinode(struct inode *inode);
2112 extern int ext4_can_truncate(struct inode *inode);
2113 extern void ext4_truncate(struct inode *);
2114 extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length);
2115 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2116 extern void ext4_set_inode_flags(struct inode *);
2117 extern void ext4_get_inode_flags(struct ext4_inode_info *);
2118 extern int ext4_alloc_da_blocks(struct inode *inode);
2119 extern void ext4_set_aops(struct inode *inode);
2120 extern int ext4_writepage_trans_blocks(struct inode *);
2121 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2122 extern int ext4_block_truncate_page(handle_t *handle,
2123 		struct address_space *mapping, loff_t from);
2124 extern int ext4_block_zero_page_range(handle_t *handle,
2125 		struct address_space *mapping, loff_t from, loff_t length);
2126 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
2127 			     loff_t lstart, loff_t lend);
2128 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2129 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2130 extern void ext4_da_update_reserve_space(struct inode *inode,
2131 					int used, int quota_claim);
2132 
2133 /* indirect.c */
2134 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2135 				struct ext4_map_blocks *map, int flags);
2136 extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
2137 				const struct iovec *iov, loff_t offset,
2138 				unsigned long nr_segs);
2139 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2140 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2141 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2142 extern int ext4_free_hole_blocks(handle_t *handle, struct inode *inode,
2143 				 ext4_lblk_t first, ext4_lblk_t stop);
2144 
2145 /* ioctl.c */
2146 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2147 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2148 
2149 /* migrate.c */
2150 extern int ext4_ext_migrate(struct inode *);
2151 extern int ext4_ind_migrate(struct inode *inode);
2152 
2153 /* namei.c */
2154 extern int ext4_dirent_csum_verify(struct inode *inode,
2155 				   struct ext4_dir_entry *dirent);
2156 extern int ext4_orphan_add(handle_t *, struct inode *);
2157 extern int ext4_orphan_del(handle_t *, struct inode *);
2158 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2159 				__u32 start_minor_hash, __u32 *next_hash);
2160 extern int search_dir(struct buffer_head *bh,
2161 		      char *search_buf,
2162 		      int buf_size,
2163 		      struct inode *dir,
2164 		      const struct qstr *d_name,
2165 		      unsigned int offset,
2166 		      struct ext4_dir_entry_2 **res_dir);
2167 extern int ext4_generic_delete_entry(handle_t *handle,
2168 				     struct inode *dir,
2169 				     struct ext4_dir_entry_2 *de_del,
2170 				     struct buffer_head *bh,
2171 				     void *entry_buf,
2172 				     int buf_size,
2173 				     int csum_size);
2174 
2175 /* resize.c */
2176 extern int ext4_group_add(struct super_block *sb,
2177 				struct ext4_new_group_data *input);
2178 extern int ext4_group_extend(struct super_block *sb,
2179 				struct ext4_super_block *es,
2180 				ext4_fsblk_t n_blocks_count);
2181 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2182 
2183 /* super.c */
2184 extern int ext4_calculate_overhead(struct super_block *sb);
2185 extern int ext4_superblock_csum_verify(struct super_block *sb,
2186 				       struct ext4_super_block *es);
2187 extern void ext4_superblock_csum_set(struct super_block *sb);
2188 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2189 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2190 extern void ext4_kvfree(void *ptr);
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_FEATURE_RO_COMPAT_METADATA_CSUM);
2333 }
2334 
2335 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2336 {
2337 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2338 		le32_to_cpu(es->s_blocks_count_lo);
2339 }
2340 
2341 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2342 {
2343 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2344 		le32_to_cpu(es->s_r_blocks_count_lo);
2345 }
2346 
2347 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2348 {
2349 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2350 		le32_to_cpu(es->s_free_blocks_count_lo);
2351 }
2352 
2353 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2354 					 ext4_fsblk_t blk)
2355 {
2356 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2357 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2358 }
2359 
2360 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2361 					      ext4_fsblk_t blk)
2362 {
2363 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2364 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2365 }
2366 
2367 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2368 					   ext4_fsblk_t blk)
2369 {
2370 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2371 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2372 }
2373 
2374 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2375 {
2376 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2377 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2378 			le32_to_cpu(raw_inode->i_size_lo);
2379 	else
2380 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2381 }
2382 
2383 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2384 {
2385 	raw_inode->i_size_lo = cpu_to_le32(i_size);
2386 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2387 }
2388 
2389 static inline
2390 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2391 					    ext4_group_t group)
2392 {
2393 	 struct ext4_group_info ***grp_info;
2394 	 long indexv, indexh;
2395 	 BUG_ON(group >= EXT4_SB(sb)->s_groups_count);
2396 	 grp_info = EXT4_SB(sb)->s_group_info;
2397 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2398 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2399 	 return grp_info[indexv][indexh];
2400 }
2401 
2402 /*
2403  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2404  * the locking protocol documented in the comments of ext4_group_add()
2405  * in resize.c
2406  */
2407 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2408 {
2409 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
2410 
2411 	smp_rmb();
2412 	return ngroups;
2413 }
2414 
2415 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2416 					     ext4_group_t block_group)
2417 {
2418 	return block_group >> sbi->s_log_groups_per_flex;
2419 }
2420 
2421 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2422 {
2423 	return 1 << sbi->s_log_groups_per_flex;
2424 }
2425 
2426 #define ext4_std_error(sb, errno)				\
2427 do {								\
2428 	if ((errno))						\
2429 		__ext4_std_error((sb), __func__, __LINE__, (errno));	\
2430 } while (0)
2431 
2432 #ifdef CONFIG_SMP
2433 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2434  * counters. So we need to make sure we have free clusters more
2435  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2436  */
2437 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2438 #else
2439 #define EXT4_FREECLUSTERS_WATERMARK 0
2440 #endif
2441 
2442 /* Update i_disksize. Requires i_mutex to avoid races with truncate */
2443 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2444 {
2445 	WARN_ON_ONCE(S_ISREG(inode->i_mode) &&
2446 		     !mutex_is_locked(&inode->i_mutex));
2447 	down_write(&EXT4_I(inode)->i_data_sem);
2448 	if (newsize > EXT4_I(inode)->i_disksize)
2449 		EXT4_I(inode)->i_disksize = newsize;
2450 	up_write(&EXT4_I(inode)->i_data_sem);
2451 }
2452 
2453 /*
2454  * Update i_disksize after writeback has been started. Races with truncate
2455  * are avoided by checking i_size under i_data_sem.
2456  */
2457 static inline void ext4_wb_update_i_disksize(struct inode *inode, loff_t newsize)
2458 {
2459 	loff_t i_size;
2460 
2461 	down_write(&EXT4_I(inode)->i_data_sem);
2462 	i_size = i_size_read(inode);
2463 	if (newsize > i_size)
2464 		newsize = i_size;
2465 	if (newsize > EXT4_I(inode)->i_disksize)
2466 		EXT4_I(inode)->i_disksize = newsize;
2467 	up_write(&EXT4_I(inode)->i_data_sem);
2468 }
2469 
2470 struct ext4_group_info {
2471 	unsigned long   bb_state;
2472 	struct rb_root  bb_free_root;
2473 	ext4_grpblk_t	bb_first_free;	/* first free block */
2474 	ext4_grpblk_t	bb_free;	/* total free blocks */
2475 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
2476 	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
2477 	struct          list_head bb_prealloc_list;
2478 #ifdef DOUBLE_CHECK
2479 	void            *bb_bitmap;
2480 #endif
2481 	struct rw_semaphore alloc_sem;
2482 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
2483 					 * regions, index is order.
2484 					 * bb_counters[3] = 5 means
2485 					 * 5 free 8-block regions. */
2486 };
2487 
2488 #define EXT4_GROUP_INFO_NEED_INIT_BIT		0
2489 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT		1
2490 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT	2
2491 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT	3
2492 
2493 #define EXT4_MB_GRP_NEED_INIT(grp)	\
2494 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2495 #define EXT4_MB_GRP_BBITMAP_CORRUPT(grp)	\
2496 	(test_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2497 #define EXT4_MB_GRP_IBITMAP_CORRUPT(grp)	\
2498 	(test_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2499 
2500 #define EXT4_MB_GRP_WAS_TRIMMED(grp)	\
2501 	(test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2502 #define EXT4_MB_GRP_SET_TRIMMED(grp)	\
2503 	(set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2504 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)	\
2505 	(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2506 
2507 #define EXT4_MAX_CONTENTION		8
2508 #define EXT4_CONTENTION_THRESHOLD	2
2509 
2510 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2511 					      ext4_group_t group)
2512 {
2513 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2514 }
2515 
2516 /*
2517  * Returns true if the filesystem is busy enough that attempts to
2518  * access the block group locks has run into contention.
2519  */
2520 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2521 {
2522 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2523 }
2524 
2525 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2526 {
2527 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2528 	if (spin_trylock(lock))
2529 		/*
2530 		 * We're able to grab the lock right away, so drop the
2531 		 * lock contention counter.
2532 		 */
2533 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2534 	else {
2535 		/*
2536 		 * The lock is busy, so bump the contention counter,
2537 		 * and then wait on the spin lock.
2538 		 */
2539 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2540 				  EXT4_MAX_CONTENTION);
2541 		spin_lock(lock);
2542 	}
2543 }
2544 
2545 static inline void ext4_unlock_group(struct super_block *sb,
2546 					ext4_group_t group)
2547 {
2548 	spin_unlock(ext4_group_lock_ptr(sb, group));
2549 }
2550 
2551 /*
2552  * Block validity checking
2553  */
2554 #define ext4_check_indirect_blockref(inode, bh)				\
2555 	ext4_check_blockref(__func__, __LINE__, inode,			\
2556 			    (__le32 *)(bh)->b_data,			\
2557 			    EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2558 
2559 #define ext4_ind_check_inode(inode)					\
2560 	ext4_check_blockref(__func__, __LINE__, inode,			\
2561 			    EXT4_I(inode)->i_data,			\
2562 			    EXT4_NDIR_BLOCKS)
2563 
2564 /*
2565  * Inodes and files operations
2566  */
2567 
2568 /* dir.c */
2569 extern const struct file_operations ext4_dir_operations;
2570 
2571 /* file.c */
2572 extern const struct inode_operations ext4_file_inode_operations;
2573 extern const struct file_operations ext4_file_operations;
2574 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2575 extern void ext4_unwritten_wait(struct inode *inode);
2576 
2577 /* inline.c */
2578 extern int ext4_has_inline_data(struct inode *inode);
2579 extern int ext4_get_inline_size(struct inode *inode);
2580 extern int ext4_get_max_inline_size(struct inode *inode);
2581 extern int ext4_find_inline_data_nolock(struct inode *inode);
2582 extern void ext4_write_inline_data(struct inode *inode,
2583 				   struct ext4_iloc *iloc,
2584 				   void *buffer, loff_t pos,
2585 				   unsigned int len);
2586 extern int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
2587 				    unsigned int len);
2588 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
2589 				 unsigned int len);
2590 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
2591 
2592 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
2593 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
2594 					 struct inode *inode,
2595 					 loff_t pos, unsigned len,
2596 					 unsigned flags,
2597 					 struct page **pagep);
2598 extern int ext4_write_inline_data_end(struct inode *inode,
2599 				      loff_t pos, unsigned len,
2600 				      unsigned copied,
2601 				      struct page *page);
2602 extern struct buffer_head *
2603 ext4_journalled_write_inline_data(struct inode *inode,
2604 				  unsigned len,
2605 				  struct page *page);
2606 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
2607 					   struct inode *inode,
2608 					   loff_t pos, unsigned len,
2609 					   unsigned flags,
2610 					   struct page **pagep,
2611 					   void **fsdata);
2612 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
2613 					 unsigned len, unsigned copied,
2614 					 struct page *page);
2615 extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
2616 				     struct inode *inode);
2617 extern int ext4_try_create_inline_dir(handle_t *handle,
2618 				      struct inode *parent,
2619 				      struct inode *inode);
2620 extern int ext4_read_inline_dir(struct file *filp,
2621 				struct dir_context *ctx,
2622 				int *has_inline_data);
2623 extern int htree_inlinedir_to_tree(struct file *dir_file,
2624 				   struct inode *dir, ext4_lblk_t block,
2625 				   struct dx_hash_info *hinfo,
2626 				   __u32 start_hash, __u32 start_minor_hash,
2627 				   int *has_inline_data);
2628 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
2629 					const struct qstr *d_name,
2630 					struct ext4_dir_entry_2 **res_dir,
2631 					int *has_inline_data);
2632 extern int ext4_delete_inline_entry(handle_t *handle,
2633 				    struct inode *dir,
2634 				    struct ext4_dir_entry_2 *de_del,
2635 				    struct buffer_head *bh,
2636 				    int *has_inline_data);
2637 extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
2638 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
2639 					struct ext4_dir_entry_2 **parent_de,
2640 					int *retval);
2641 extern int ext4_inline_data_fiemap(struct inode *inode,
2642 				   struct fiemap_extent_info *fieinfo,
2643 				   int *has_inline);
2644 extern int ext4_try_to_evict_inline_data(handle_t *handle,
2645 					 struct inode *inode,
2646 					 int needed);
2647 extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
2648 
2649 extern int ext4_convert_inline_data(struct inode *inode);
2650 
2651 /* namei.c */
2652 extern const struct inode_operations ext4_dir_inode_operations;
2653 extern const struct inode_operations ext4_special_inode_operations;
2654 extern struct dentry *ext4_get_parent(struct dentry *child);
2655 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2656 				 struct ext4_dir_entry_2 *de,
2657 				 int blocksize, int csum_size,
2658 				 unsigned int parent_ino, int dotdot_real_len);
2659 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
2660 				   unsigned int blocksize);
2661 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
2662 					 struct inode *inode,
2663 					 struct buffer_head *bh);
2664 #define S_SHIFT 12
2665 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
2666 	[S_IFREG >> S_SHIFT]	= EXT4_FT_REG_FILE,
2667 	[S_IFDIR >> S_SHIFT]	= EXT4_FT_DIR,
2668 	[S_IFCHR >> S_SHIFT]	= EXT4_FT_CHRDEV,
2669 	[S_IFBLK >> S_SHIFT]	= EXT4_FT_BLKDEV,
2670 	[S_IFIFO >> S_SHIFT]	= EXT4_FT_FIFO,
2671 	[S_IFSOCK >> S_SHIFT]	= EXT4_FT_SOCK,
2672 	[S_IFLNK >> S_SHIFT]	= EXT4_FT_SYMLINK,
2673 };
2674 
2675 static inline void ext4_set_de_type(struct super_block *sb,
2676 				struct ext4_dir_entry_2 *de,
2677 				umode_t mode) {
2678 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
2679 		de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
2680 }
2681 
2682 
2683 /* symlink.c */
2684 extern const struct inode_operations ext4_symlink_inode_operations;
2685 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2686 
2687 /* block_validity */
2688 extern void ext4_release_system_zone(struct super_block *sb);
2689 extern int ext4_setup_system_zone(struct super_block *sb);
2690 extern int __init ext4_init_system_zone(void);
2691 extern void ext4_exit_system_zone(void);
2692 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2693 				 ext4_fsblk_t start_blk,
2694 				 unsigned int count);
2695 extern int ext4_check_blockref(const char *, unsigned int,
2696 			       struct inode *, __le32 *, unsigned int);
2697 
2698 /* extents.c */
2699 struct ext4_ext_path;
2700 struct ext4_extent;
2701 
2702 /*
2703  * Maximum number of logical blocks in a file; ext4_extent's ee_block is
2704  * __le32.
2705  */
2706 #define EXT_MAX_BLOCKS	0xffffffff
2707 
2708 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2709 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2710 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
2711 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2712 			       struct ext4_map_blocks *map, int flags);
2713 extern void ext4_ext_truncate(handle_t *, struct inode *);
2714 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2715 				 ext4_lblk_t end);
2716 extern void ext4_ext_init(struct super_block *);
2717 extern void ext4_ext_release(struct super_block *);
2718 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2719 			  loff_t len);
2720 extern int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
2721 					  loff_t offset, ssize_t len);
2722 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2723 			   struct ext4_map_blocks *map, int flags);
2724 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
2725 					 ext4_lblk_t lblocks);
2726 extern int ext4_extent_tree_init(handle_t *, struct inode *);
2727 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
2728 						   int num,
2729 						   struct ext4_ext_path *path);
2730 extern int ext4_can_extents_be_merged(struct inode *inode,
2731 				      struct ext4_extent *ex1,
2732 				      struct ext4_extent *ex2);
2733 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
2734 				  struct ext4_ext_path *,
2735 				  struct ext4_extent *, int);
2736 extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
2737 						  struct ext4_ext_path *,
2738 						  int flags);
2739 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
2740 extern int ext4_ext_check_inode(struct inode *inode);
2741 extern int ext4_find_delalloc_range(struct inode *inode,
2742 				    ext4_lblk_t lblk_start,
2743 				    ext4_lblk_t lblk_end);
2744 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
2745 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2746 			__u64 start, __u64 len);
2747 extern int ext4_ext_precache(struct inode *inode);
2748 
2749 /* move_extent.c */
2750 extern void ext4_double_down_write_data_sem(struct inode *first,
2751 					    struct inode *second);
2752 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
2753 					  struct inode *donor_inode);
2754 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2755 			     __u64 start_orig, __u64 start_donor,
2756 			     __u64 len, __u64 *moved_len);
2757 
2758 /* page-io.c */
2759 extern int __init ext4_init_pageio(void);
2760 extern void ext4_exit_pageio(void);
2761 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2762 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
2763 extern int ext4_put_io_end(ext4_io_end_t *io_end);
2764 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
2765 extern void ext4_io_submit_init(struct ext4_io_submit *io,
2766 				struct writeback_control *wbc);
2767 extern void ext4_end_io_rsv_work(struct work_struct *work);
2768 extern void ext4_io_submit(struct ext4_io_submit *io);
2769 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2770 			       struct page *page,
2771 			       int len,
2772 			       struct writeback_control *wbc);
2773 
2774 /* mmp.c */
2775 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2776 extern void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp);
2777 extern int ext4_mmp_csum_verify(struct super_block *sb,
2778 				struct mmp_struct *mmp);
2779 
2780 /*
2781  * Note that these flags will never ever appear in a buffer_head's state flag.
2782  * See EXT4_MAP_... to see where this is used.
2783  */
2784 enum ext4_state_bits {
2785 	BH_Uninit	/* blocks are allocated but uninitialized on disk */
2786 	 = BH_JBDPrivateStart,
2787 	BH_AllocFromCluster,	/* allocated blocks were part of already
2788 				 * allocated cluster. */
2789 };
2790 
2791 /*
2792  * Add new method to test whether block and inode bitmaps are properly
2793  * initialized. With uninit_bg reading the block from disk is not enough
2794  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2795  */
2796 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2797 
2798 static inline int bitmap_uptodate(struct buffer_head *bh)
2799 {
2800 	return (buffer_uptodate(bh) &&
2801 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2802 }
2803 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2804 {
2805 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2806 }
2807 
2808 /*
2809  * Disable DIO read nolock optimization, so new dioreaders will be forced
2810  * to grab i_mutex
2811  */
2812 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
2813 {
2814 	ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2815 	smp_mb();
2816 }
2817 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
2818 {
2819 	smp_mb();
2820 	ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2821 }
2822 
2823 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
2824 
2825 /* For ioend & aio unwritten conversion wait queues */
2826 #define EXT4_WQ_HASH_SZ		37
2827 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2828 					    EXT4_WQ_HASH_SZ])
2829 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2830 					     EXT4_WQ_HASH_SZ])
2831 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2832 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2833 
2834 #define EXT4_RESIZING	0
2835 extern int ext4_resize_begin(struct super_block *sb);
2836 extern void ext4_resize_end(struct super_block *sb);
2837 
2838 #endif	/* __KERNEL__ */
2839 
2840 #endif	/* _EXT4_H */
2841