xref: /openbmc/linux/fs/ext4/ext4.h (revision 3613d228)
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 <crypto/hash.h>
33 #ifdef __KERNEL__
34 #include <linux/compat.h>
35 #endif
36 
37 /*
38  * The fourth extended filesystem constants/structures
39  */
40 
41 /*
42  * Define EXT4FS_DEBUG to produce debug messages
43  */
44 #undef EXT4FS_DEBUG
45 
46 /*
47  * Debug code
48  */
49 #ifdef EXT4FS_DEBUG
50 #define ext4_debug(f, a...)						\
51 	do {								\
52 		printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",	\
53 			__FILE__, __LINE__, __func__);			\
54 		printk(KERN_DEBUG f, ## a);				\
55 	} while (0)
56 #else
57 #define ext4_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
58 #endif
59 
60 /*
61  * Turn on EXT_DEBUG to get lots of info about extents operations.
62  */
63 #define EXT_DEBUG__
64 #ifdef EXT_DEBUG
65 #define ext_debug(fmt, ...)	printk(fmt, ##__VA_ARGS__)
66 #else
67 #define ext_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
68 #endif
69 
70 #define EXT4_ERROR_INODE(inode, fmt, a...) \
71 	ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
72 
73 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)			\
74 	ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
75 
76 #define EXT4_ERROR_FILE(file, block, fmt, a...)				\
77 	ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
78 
79 /* data type for block offset of block group */
80 typedef int ext4_grpblk_t;
81 
82 /* data type for filesystem-wide blocks number */
83 typedef unsigned long long ext4_fsblk_t;
84 
85 /* data type for file logical block number */
86 typedef __u32 ext4_lblk_t;
87 
88 /* data type for block group number */
89 typedef unsigned int ext4_group_t;
90 
91 /*
92  * Flags used in mballoc's allocation_context flags field.
93  *
94  * Also used to show what's going on for debugging purposes when the
95  * flag field is exported via the traceport interface
96  */
97 
98 /* prefer goal again. length */
99 #define EXT4_MB_HINT_MERGE		0x0001
100 /* blocks already reserved */
101 #define EXT4_MB_HINT_RESERVED		0x0002
102 /* metadata is being allocated */
103 #define EXT4_MB_HINT_METADATA		0x0004
104 /* first blocks in the file */
105 #define EXT4_MB_HINT_FIRST		0x0008
106 /* search for the best chunk */
107 #define EXT4_MB_HINT_BEST		0x0010
108 /* data is being allocated */
109 #define EXT4_MB_HINT_DATA		0x0020
110 /* don't preallocate (for tails) */
111 #define EXT4_MB_HINT_NOPREALLOC		0x0040
112 /* allocate for locality group */
113 #define EXT4_MB_HINT_GROUP_ALLOC	0x0080
114 /* allocate goal blocks or none */
115 #define EXT4_MB_HINT_GOAL_ONLY		0x0100
116 /* goal is meaningful */
117 #define EXT4_MB_HINT_TRY_GOAL		0x0200
118 /* blocks already pre-reserved by delayed allocation */
119 #define EXT4_MB_DELALLOC_RESERVED	0x0400
120 /* We are doing stream allocation */
121 #define EXT4_MB_STREAM_ALLOC		0x0800
122 /* Use reserved root blocks if needed */
123 #define EXT4_MB_USE_ROOT_BLOCKS		0x1000
124 /* Use blocks from reserved pool */
125 #define EXT4_MB_USE_RESERVED		0x2000
126 
127 struct ext4_allocation_request {
128 	/* target inode for block we're allocating */
129 	struct inode *inode;
130 	/* how many blocks we want to allocate */
131 	unsigned int len;
132 	/* logical block in target inode */
133 	ext4_lblk_t logical;
134 	/* the closest logical allocated block to the left */
135 	ext4_lblk_t lleft;
136 	/* the closest logical allocated block to the right */
137 	ext4_lblk_t lright;
138 	/* phys. target (a hint) */
139 	ext4_fsblk_t goal;
140 	/* phys. block for the closest logical allocated block to the left */
141 	ext4_fsblk_t pleft;
142 	/* phys. block for the closest logical allocated block to the right */
143 	ext4_fsblk_t pright;
144 	/* flags. see above EXT4_MB_HINT_* */
145 	unsigned int flags;
146 };
147 
148 /*
149  * Logical to physical block mapping, used by ext4_map_blocks()
150  *
151  * This structure is used to pass requests into ext4_map_blocks() as
152  * well as to store the information returned by ext4_map_blocks().  It
153  * takes less room on the stack than a struct buffer_head.
154  */
155 #define EXT4_MAP_NEW		(1 << BH_New)
156 #define EXT4_MAP_MAPPED		(1 << BH_Mapped)
157 #define EXT4_MAP_UNWRITTEN	(1 << BH_Unwritten)
158 #define EXT4_MAP_BOUNDARY	(1 << BH_Boundary)
159 #define EXT4_MAP_UNINIT		(1 << BH_Uninit)
160 /* Sometimes (in the bigalloc case, from ext4_da_get_block_prep) the caller of
161  * ext4_map_blocks wants to know whether or not the underlying cluster has
162  * already been accounted for. EXT4_MAP_FROM_CLUSTER conveys to the caller that
163  * the requested mapping was from previously mapped (or delayed allocated)
164  * cluster. We use BH_AllocFromCluster only for this flag. BH_AllocFromCluster
165  * should never appear on buffer_head's state flags.
166  */
167 #define EXT4_MAP_FROM_CLUSTER	(1 << BH_AllocFromCluster)
168 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
169 				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
170 				 EXT4_MAP_UNINIT | EXT4_MAP_FROM_CLUSTER)
171 
172 struct ext4_map_blocks {
173 	ext4_fsblk_t m_pblk;
174 	ext4_lblk_t m_lblk;
175 	unsigned int m_len;
176 	unsigned int m_flags;
177 };
178 
179 /*
180  * Flags for ext4_io_end->flags
181  */
182 #define	EXT4_IO_END_UNWRITTEN	0x0001
183 #define EXT4_IO_END_ERROR	0x0002
184 #define EXT4_IO_END_DIRECT	0x0004
185 
186 /*
187  * For converting uninitialized extents on a work queue.
188  */
189 typedef struct ext4_io_end {
190 	struct list_head	list;		/* per-file finished IO list */
191 	struct inode		*inode;		/* file being written to */
192 	unsigned int		flag;		/* unwritten or not */
193 	loff_t			offset;		/* offset in the file */
194 	ssize_t			size;		/* size of the extent */
195 	struct kiocb		*iocb;		/* iocb struct for AIO */
196 	int			result;		/* error value for AIO */
197 	atomic_t		count;		/* reference counter */
198 } ext4_io_end_t;
199 
200 struct ext4_io_submit {
201 	int			io_op;
202 	struct bio		*io_bio;
203 	ext4_io_end_t		*io_end;
204 	sector_t		io_next_block;
205 };
206 
207 /*
208  * Special inodes numbers
209  */
210 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
211 #define EXT4_ROOT_INO		 2	/* Root inode */
212 #define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
213 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
214 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
215 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
216 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
217 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
218 
219 /* First non-reserved inode for old ext4 filesystems */
220 #define EXT4_GOOD_OLD_FIRST_INO	11
221 
222 /*
223  * Maximal count of links to a file
224  */
225 #define EXT4_LINK_MAX		65000
226 
227 /*
228  * Macro-instructions used to manage several block sizes
229  */
230 #define EXT4_MIN_BLOCK_SIZE		1024
231 #define	EXT4_MAX_BLOCK_SIZE		65536
232 #define EXT4_MIN_BLOCK_LOG_SIZE		10
233 #define EXT4_MAX_BLOCK_LOG_SIZE		16
234 #ifdef __KERNEL__
235 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
236 #else
237 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
238 #endif
239 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
240 #define EXT4_CLUSTER_SIZE(s)		(EXT4_BLOCK_SIZE(s) << \
241 					 EXT4_SB(s)->s_cluster_bits)
242 #ifdef __KERNEL__
243 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
244 # define EXT4_CLUSTER_BITS(s)		(EXT4_SB(s)->s_cluster_bits)
245 #else
246 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
247 #endif
248 #ifdef __KERNEL__
249 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
250 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
251 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
252 #else
253 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
254 				 EXT4_GOOD_OLD_INODE_SIZE : \
255 				 (s)->s_inode_size)
256 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
257 				 EXT4_GOOD_OLD_FIRST_INO : \
258 				 (s)->s_first_ino)
259 #endif
260 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
261 
262 /* Translate a block number to a cluster number */
263 #define EXT4_B2C(sbi, blk)	((blk) >> (sbi)->s_cluster_bits)
264 /* Translate a cluster number to a block number */
265 #define EXT4_C2B(sbi, cluster)	((cluster) << (sbi)->s_cluster_bits)
266 /* Translate # of blks to # of clusters */
267 #define EXT4_NUM_B2C(sbi, blks)	(((blks) + (sbi)->s_cluster_ratio - 1) >> \
268 				 (sbi)->s_cluster_bits)
269 
270 /*
271  * Structure of a blocks group descriptor
272  */
273 struct ext4_group_desc
274 {
275 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
276 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
277 	__le32	bg_inode_table_lo;	/* Inodes table block */
278 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
279 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
280 	__le16	bg_used_dirs_count_lo;	/* Directories count */
281 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
282 	__le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
283 	__le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
284 	__le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
285 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
286 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
287 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
288 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
289 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
290 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
291 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
292 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
293 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
294 	__le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
295 	__le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
296 	__le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
297 	__u32   bg_reserved;
298 };
299 
300 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END	\
301 	(offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
302 	 sizeof(__le16))
303 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END	\
304 	(offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
305 	 sizeof(__le16))
306 
307 /*
308  * Structure of a flex block group info
309  */
310 
311 struct flex_groups {
312 	atomic64_t	free_clusters;
313 	atomic_t	free_inodes;
314 	atomic_t	used_dirs;
315 };
316 
317 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
318 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
319 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
320 
321 /*
322  * Macro-instructions used to manage group descriptors
323  */
324 #define EXT4_MIN_DESC_SIZE		32
325 #define EXT4_MIN_DESC_SIZE_64BIT	64
326 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
327 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
328 #ifdef __KERNEL__
329 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
330 # define EXT4_CLUSTERS_PER_GROUP(s)	(EXT4_SB(s)->s_clusters_per_group)
331 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
332 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
333 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
334 #else
335 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
336 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
337 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
338 #endif
339 
340 /*
341  * Constants relative to the data blocks
342  */
343 #define	EXT4_NDIR_BLOCKS		12
344 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
345 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
346 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
347 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
348 
349 /*
350  * Inode flags
351  */
352 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
353 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
354 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
355 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
356 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
357 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
358 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
359 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
360 /* Reserved for compression usage... */
361 #define EXT4_DIRTY_FL			0x00000100
362 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
363 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
364 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
365 /* End compression flags --- maybe not all used */
366 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
367 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
368 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
369 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
370 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
371 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
372 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
373 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
374 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
375 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
376 #define EXT4_INLINE_DATA_FL		0x10000000 /* Inode has inline data. */
377 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
378 
379 #define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
380 #define EXT4_FL_USER_MODIFIABLE		0x004380FF /* User modifiable flags */
381 
382 /* Flags that should be inherited by new inodes from their parent. */
383 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
384 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
385 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
386 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
387 
388 /* Flags that are appropriate for regular files (all but dir-specific ones). */
389 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
390 
391 /* Flags that are appropriate for non-directories/regular files. */
392 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
393 
394 /* Mask out flags that are inappropriate for the given type of inode. */
395 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
396 {
397 	if (S_ISDIR(mode))
398 		return flags;
399 	else if (S_ISREG(mode))
400 		return flags & EXT4_REG_FLMASK;
401 	else
402 		return flags & EXT4_OTHER_FLMASK;
403 }
404 
405 /*
406  * Inode flags used for atomic set/get
407  */
408 enum {
409 	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
410 	EXT4_INODE_UNRM		= 1,	/* Undelete */
411 	EXT4_INODE_COMPR	= 2,	/* Compress file */
412 	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
413 	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
414 	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
415 	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
416 	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
417 /* Reserved for compression usage... */
418 	EXT4_INODE_DIRTY	= 8,
419 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
420 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
421 	EXT4_INODE_ECOMPR	= 11,	/* Compression error */
422 /* End compression flags --- maybe not all used */
423 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
424 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
425 	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
426 	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
427 	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
428 	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
429 	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
430 	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
431 	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
432 	EXT4_INODE_EOFBLOCKS	= 22,	/* Blocks allocated beyond EOF */
433 	EXT4_INODE_INLINE_DATA	= 28,	/* Data in inode. */
434 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
435 };
436 
437 /*
438  * Since it's pretty easy to mix up bit numbers and hex values, we use a
439  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
440  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
441  * any extra space in the compiled kernel image, otherwise, the build will fail.
442  * It's important that these values are the same, since we are using
443  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
444  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
445  * values found in ext2, ext3 and ext4 filesystems, and of course the values
446  * defined in e2fsprogs.
447  *
448  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
449  */
450 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
451 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
452 
453 static inline void ext4_check_flag_values(void)
454 {
455 	CHECK_FLAG_VALUE(SECRM);
456 	CHECK_FLAG_VALUE(UNRM);
457 	CHECK_FLAG_VALUE(COMPR);
458 	CHECK_FLAG_VALUE(SYNC);
459 	CHECK_FLAG_VALUE(IMMUTABLE);
460 	CHECK_FLAG_VALUE(APPEND);
461 	CHECK_FLAG_VALUE(NODUMP);
462 	CHECK_FLAG_VALUE(NOATIME);
463 	CHECK_FLAG_VALUE(DIRTY);
464 	CHECK_FLAG_VALUE(COMPRBLK);
465 	CHECK_FLAG_VALUE(NOCOMPR);
466 	CHECK_FLAG_VALUE(ECOMPR);
467 	CHECK_FLAG_VALUE(INDEX);
468 	CHECK_FLAG_VALUE(IMAGIC);
469 	CHECK_FLAG_VALUE(JOURNAL_DATA);
470 	CHECK_FLAG_VALUE(NOTAIL);
471 	CHECK_FLAG_VALUE(DIRSYNC);
472 	CHECK_FLAG_VALUE(TOPDIR);
473 	CHECK_FLAG_VALUE(HUGE_FILE);
474 	CHECK_FLAG_VALUE(EXTENTS);
475 	CHECK_FLAG_VALUE(EA_INODE);
476 	CHECK_FLAG_VALUE(EOFBLOCKS);
477 	CHECK_FLAG_VALUE(INLINE_DATA);
478 	CHECK_FLAG_VALUE(RESERVED);
479 }
480 
481 /* Used to pass group descriptor data when online resize is done */
482 struct ext4_new_group_input {
483 	__u32 group;		/* Group number for this data */
484 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
485 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
486 	__u64 inode_table;	/* Absolute block number of inode table start */
487 	__u32 blocks_count;	/* Total number of blocks in this group */
488 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
489 	__u16 unused;
490 };
491 
492 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
493 struct compat_ext4_new_group_input {
494 	u32 group;
495 	compat_u64 block_bitmap;
496 	compat_u64 inode_bitmap;
497 	compat_u64 inode_table;
498 	u32 blocks_count;
499 	u16 reserved_blocks;
500 	u16 unused;
501 };
502 #endif
503 
504 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
505 struct ext4_new_group_data {
506 	__u32 group;
507 	__u64 block_bitmap;
508 	__u64 inode_bitmap;
509 	__u64 inode_table;
510 	__u32 blocks_count;
511 	__u16 reserved_blocks;
512 	__u16 unused;
513 	__u32 free_blocks_count;
514 };
515 
516 /* Indexes used to index group tables in ext4_new_group_data */
517 enum {
518 	BLOCK_BITMAP = 0,	/* block bitmap */
519 	INODE_BITMAP,		/* inode bitmap */
520 	INODE_TABLE,		/* inode tables */
521 	GROUP_TABLE_COUNT,
522 };
523 
524 /*
525  * Flags used by ext4_map_blocks()
526  */
527 	/* Allocate any needed blocks and/or convert an unitialized
528 	   extent to be an initialized ext4 */
529 #define EXT4_GET_BLOCKS_CREATE			0x0001
530 	/* Request the creation of an unitialized extent */
531 #define EXT4_GET_BLOCKS_UNINIT_EXT		0x0002
532 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\
533 						 EXT4_GET_BLOCKS_CREATE)
534 	/* Caller is from the delayed allocation writeout path
535 	 * finally doing the actual allocation of delayed blocks */
536 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
537 	/* caller is from the direct IO path, request to creation of an
538 	unitialized extents if not allocated, split the uninitialized
539 	extent if blocks has been preallocated already*/
540 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
541 #define EXT4_GET_BLOCKS_CONVERT			0x0010
542 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
543 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
544 	/* Convert extent to initialized after IO complete */
545 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
546 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
547 	/* Eventual metadata allocation (due to growing extent tree)
548 	 * should not fail, so try to use reserved blocks for that.*/
549 #define EXT4_GET_BLOCKS_METADATA_NOFAIL		0x0020
550 	/* Don't normalize allocation size (used for fallocate) */
551 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
552 	/* Request will not result in inode size update (user for fallocate) */
553 #define EXT4_GET_BLOCKS_KEEP_SIZE		0x0080
554 	/* Do not take i_data_sem locking in ext4_map_blocks */
555 #define EXT4_GET_BLOCKS_NO_LOCK			0x0100
556 	/* Do not put hole in extent cache */
557 #define EXT4_GET_BLOCKS_NO_PUT_HOLE		0x0200
558 
559 /*
560  * Flags used by ext4_free_blocks
561  */
562 #define EXT4_FREE_BLOCKS_METADATA	0x0001
563 #define EXT4_FREE_BLOCKS_FORGET		0x0002
564 #define EXT4_FREE_BLOCKS_VALIDATED	0x0004
565 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE	0x0008
566 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
567 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
568 
569 /*
570  * ioctl commands
571  */
572 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
573 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
574 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
575 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
576 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
577 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
578 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
579 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
580 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
581 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
582 #define EXT4_IOC_MIGRATE		_IO('f', 9)
583  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
584  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
585 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
586 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
587 #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
588 #define EXT4_IOC_SWAP_BOOT		_IO('f', 17)
589 
590 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
591 /*
592  * ioctl commands in 32 bit emulation
593  */
594 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
595 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
596 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
597 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
598 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
599 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
600 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
601 #define EXT4_IOC32_GROUP_ADD		_IOW('f', 8, struct compat_ext4_new_group_input)
602 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
603 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
604 #endif
605 
606 /* Max physical block we can address w/o extents */
607 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
608 
609 /*
610  * Structure of an inode on the disk
611  */
612 struct ext4_inode {
613 	__le16	i_mode;		/* File mode */
614 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
615 	__le32	i_size_lo;	/* Size in bytes */
616 	__le32	i_atime;	/* Access time */
617 	__le32	i_ctime;	/* Inode Change time */
618 	__le32	i_mtime;	/* Modification time */
619 	__le32	i_dtime;	/* Deletion Time */
620 	__le16	i_gid;		/* Low 16 bits of Group Id */
621 	__le16	i_links_count;	/* Links count */
622 	__le32	i_blocks_lo;	/* Blocks count */
623 	__le32	i_flags;	/* File flags */
624 	union {
625 		struct {
626 			__le32  l_i_version;
627 		} linux1;
628 		struct {
629 			__u32  h_i_translator;
630 		} hurd1;
631 		struct {
632 			__u32  m_i_reserved1;
633 		} masix1;
634 	} osd1;				/* OS dependent 1 */
635 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
636 	__le32	i_generation;	/* File version (for NFS) */
637 	__le32	i_file_acl_lo;	/* File ACL */
638 	__le32	i_size_high;
639 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
640 	union {
641 		struct {
642 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
643 			__le16	l_i_file_acl_high;
644 			__le16	l_i_uid_high;	/* these 2 fields */
645 			__le16	l_i_gid_high;	/* were reserved2[0] */
646 			__le16	l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
647 			__le16	l_i_reserved;
648 		} linux2;
649 		struct {
650 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
651 			__u16	h_i_mode_high;
652 			__u16	h_i_uid_high;
653 			__u16	h_i_gid_high;
654 			__u32	h_i_author;
655 		} hurd2;
656 		struct {
657 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
658 			__le16	m_i_file_acl_high;
659 			__u32	m_i_reserved2[2];
660 		} masix2;
661 	} osd2;				/* OS dependent 2 */
662 	__le16	i_extra_isize;
663 	__le16	i_checksum_hi;	/* crc32c(uuid+inum+inode) BE */
664 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
665 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
666 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
667 	__le32  i_crtime;       /* File Creation time */
668 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
669 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
670 };
671 
672 struct move_extent {
673 	__u32 reserved;		/* should be zero */
674 	__u32 donor_fd;		/* donor file descriptor */
675 	__u64 orig_start;	/* logical start offset in block for orig */
676 	__u64 donor_start;	/* logical start offset in block for donor */
677 	__u64 len;		/* block length to be moved */
678 	__u64 moved_len;	/* moved block length */
679 };
680 
681 #define EXT4_EPOCH_BITS 2
682 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
683 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
684 
685 /*
686  * Extended fields will fit into an inode if the filesystem was formatted
687  * with large inodes (-I 256 or larger) and there are not currently any EAs
688  * consuming all of the available space. For new inodes we always reserve
689  * enough space for the kernel's known extended fields, but for inodes
690  * created with an old kernel this might not have been the case. None of
691  * the extended inode fields is critical for correct filesystem operation.
692  * This macro checks if a certain field fits in the inode. Note that
693  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
694  */
695 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
696 	((offsetof(typeof(*ext4_inode), field) +	\
697 	  sizeof((ext4_inode)->field))			\
698 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
699 	    (einode)->i_extra_isize))			\
700 
701 static inline __le32 ext4_encode_extra_time(struct timespec *time)
702 {
703        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
704 			   (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
705                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
706 }
707 
708 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
709 {
710        if (sizeof(time->tv_sec) > 4)
711 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
712 			       << 32;
713        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
714 }
715 
716 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
717 do {									       \
718 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
719 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
720 		(raw_inode)->xtime ## _extra =				       \
721 				ext4_encode_extra_time(&(inode)->xtime);       \
722 } while (0)
723 
724 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
725 do {									       \
726 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
727 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
728 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
729 		(raw_inode)->xtime ## _extra =				       \
730 				ext4_encode_extra_time(&(einode)->xtime);      \
731 } while (0)
732 
733 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
734 do {									       \
735 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
736 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
737 		ext4_decode_extra_time(&(inode)->xtime,			       \
738 				       raw_inode->xtime ## _extra);	       \
739 	else								       \
740 		(inode)->xtime.tv_nsec = 0;				       \
741 } while (0)
742 
743 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
744 do {									       \
745 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
746 		(einode)->xtime.tv_sec = 				       \
747 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
748 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
749 		ext4_decode_extra_time(&(einode)->xtime,		       \
750 				       raw_inode->xtime ## _extra);	       \
751 	else								       \
752 		(einode)->xtime.tv_nsec = 0;				       \
753 } while (0)
754 
755 #define i_disk_version osd1.linux1.l_i_version
756 
757 #if defined(__KERNEL__) || defined(__linux__)
758 #define i_reserved1	osd1.linux1.l_i_reserved1
759 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
760 #define i_blocks_high	osd2.linux2.l_i_blocks_high
761 #define i_uid_low	i_uid
762 #define i_gid_low	i_gid
763 #define i_uid_high	osd2.linux2.l_i_uid_high
764 #define i_gid_high	osd2.linux2.l_i_gid_high
765 #define i_checksum_lo	osd2.linux2.l_i_checksum_lo
766 
767 #elif defined(__GNU__)
768 
769 #define i_translator	osd1.hurd1.h_i_translator
770 #define i_uid_high	osd2.hurd2.h_i_uid_high
771 #define i_gid_high	osd2.hurd2.h_i_gid_high
772 #define i_author	osd2.hurd2.h_i_author
773 
774 #elif defined(__masix__)
775 
776 #define i_reserved1	osd1.masix1.m_i_reserved1
777 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
778 #define i_reserved2	osd2.masix2.m_i_reserved2
779 
780 #endif /* defined(__KERNEL__) || defined(__linux__) */
781 
782 #include "extents_status.h"
783 
784 /*
785  * fourth extended file system inode data in memory
786  */
787 struct ext4_inode_info {
788 	__le32	i_data[15];	/* unconverted */
789 	__u32	i_dtime;
790 	ext4_fsblk_t	i_file_acl;
791 
792 	/*
793 	 * i_block_group is the number of the block group which contains
794 	 * this file's inode.  Constant across the lifetime of the inode,
795 	 * it is ued for making block allocation decisions - we try to
796 	 * place a file's data blocks near its inode block, and new inodes
797 	 * near to their parent directory's inode.
798 	 */
799 	ext4_group_t	i_block_group;
800 	ext4_lblk_t	i_dir_start_lookup;
801 #if (BITS_PER_LONG < 64)
802 	unsigned long	i_state_flags;		/* Dynamic state flags */
803 #endif
804 	unsigned long	i_flags;
805 
806 	/*
807 	 * Extended attributes can be read independently of the main file
808 	 * data. Taking i_mutex even when reading would cause contention
809 	 * between readers of EAs and writers of regular file data, so
810 	 * instead we synchronize on xattr_sem when reading or changing
811 	 * EAs.
812 	 */
813 	struct rw_semaphore xattr_sem;
814 
815 	struct list_head i_orphan;	/* unlinked but open inodes */
816 
817 	/*
818 	 * i_disksize keeps track of what the inode size is ON DISK, not
819 	 * in memory.  During truncate, i_size is set to the new size by
820 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
821 	 * set i_disksize to 0 until the truncate is actually under way.
822 	 *
823 	 * The intent is that i_disksize always represents the blocks which
824 	 * are used by this file.  This allows recovery to restart truncate
825 	 * on orphans if we crash during truncate.  We actually write i_disksize
826 	 * into the on-disk inode when writing inodes out, instead of i_size.
827 	 *
828 	 * The only time when i_disksize and i_size may be different is when
829 	 * a truncate is in progress.  The only things which change i_disksize
830 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
831 	 */
832 	loff_t	i_disksize;
833 
834 	/*
835 	 * i_data_sem is for serialising ext4_truncate() against
836 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
837 	 * data tree are chopped off during truncate. We can't do that in
838 	 * ext4 because whenever we perform intermediate commits during
839 	 * truncate, the inode and all the metadata blocks *must* be in a
840 	 * consistent state which allows truncation of the orphans to restart
841 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
842 	 * by other means, so we have i_data_sem.
843 	 */
844 	struct rw_semaphore i_data_sem;
845 	struct inode vfs_inode;
846 	struct jbd2_inode *jinode;
847 
848 	/*
849 	 * File creation time. Its function is same as that of
850 	 * struct timespec i_{a,c,m}time in the generic inode.
851 	 */
852 	struct timespec i_crtime;
853 
854 	/* mballoc */
855 	struct list_head i_prealloc_list;
856 	spinlock_t i_prealloc_lock;
857 
858 	/* extents status tree */
859 	struct ext4_es_tree i_es_tree;
860 	rwlock_t i_es_lock;
861 	struct list_head i_es_lru;
862 	unsigned int i_es_lru_nr;	/* protected by i_es_lock */
863 
864 	/* ialloc */
865 	ext4_group_t	i_last_alloc_group;
866 
867 	/* allocation reservation info for delalloc */
868 	/* In case of bigalloc, these refer to clusters rather than blocks */
869 	unsigned int i_reserved_data_blocks;
870 	unsigned int i_reserved_meta_blocks;
871 	unsigned int i_allocated_meta_blocks;
872 	ext4_lblk_t i_da_metadata_calc_last_lblock;
873 	int i_da_metadata_calc_len;
874 
875 	/* on-disk additional length */
876 	__u16 i_extra_isize;
877 
878 	/* Indicate the inline data space. */
879 	u16 i_inline_off;
880 	u16 i_inline_size;
881 
882 #ifdef CONFIG_QUOTA
883 	/* quota space reservation, managed internally by quota code */
884 	qsize_t i_reserved_quota;
885 #endif
886 
887 	/* completed IOs that might need unwritten extents handling */
888 	struct list_head i_completed_io_list;
889 	spinlock_t i_completed_io_lock;
890 	atomic_t i_ioend_count;	/* Number of outstanding io_end structs */
891 	atomic_t i_unwritten; /* Nr. of inflight conversions pending */
892 	struct work_struct i_unwritten_work;	/* deferred extent conversion */
893 
894 	spinlock_t i_block_reservation_lock;
895 
896 	/*
897 	 * Transactions that contain inode's metadata needed to complete
898 	 * fsync and fdatasync, respectively.
899 	 */
900 	tid_t i_sync_tid;
901 	tid_t i_datasync_tid;
902 
903 	/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
904 	__u32 i_csum_seed;
905 };
906 
907 /*
908  * File system states
909  */
910 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
911 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
912 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
913 
914 /*
915  * Misc. filesystem flags
916  */
917 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
918 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
919 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
920 
921 /*
922  * Mount flags set via mount options or defaults
923  */
924 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
925 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
926 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
927 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
928 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
929 #define EXT4_MOUNT_ERRORS_MASK		0x00070
930 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
931 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
932 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
933 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
934 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
935 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
936 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
937 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
938 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
939 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
940 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
941 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
942 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
943 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
944 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
945 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
946 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
947 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
948 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
949 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
950 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
951 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
952 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
953 
954 /*
955  * Mount flags set either automatically (could not be set by mount option)
956  * based on per file system feature or property or in special cases such as
957  * distinguishing between explicit mount option definition and default.
958  */
959 #define EXT4_MOUNT2_EXPLICIT_DELALLOC	0x00000001 /* User explicitly
960 						      specified delalloc */
961 #define EXT4_MOUNT2_STD_GROUP_SIZE	0x00000002 /* We have standard group
962 						      size of blocksize * 8
963 						      blocks */
964 
965 #define clear_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt &= \
966 						~EXT4_MOUNT_##opt
967 #define set_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt |= \
968 						EXT4_MOUNT_##opt
969 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
970 					 EXT4_MOUNT_##opt)
971 
972 #define clear_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 &= \
973 						~EXT4_MOUNT2_##opt
974 #define set_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 |= \
975 						EXT4_MOUNT2_##opt
976 #define test_opt2(sb, opt)		(EXT4_SB(sb)->s_mount_opt2 & \
977 					 EXT4_MOUNT2_##opt)
978 
979 #define ext4_test_and_set_bit		__test_and_set_bit_le
980 #define ext4_set_bit			__set_bit_le
981 #define ext4_set_bit_atomic		ext2_set_bit_atomic
982 #define ext4_test_and_clear_bit		__test_and_clear_bit_le
983 #define ext4_clear_bit			__clear_bit_le
984 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
985 #define ext4_test_bit			test_bit_le
986 #define ext4_find_next_zero_bit		find_next_zero_bit_le
987 #define ext4_find_next_bit		find_next_bit_le
988 
989 extern void ext4_set_bits(void *bm, int cur, int len);
990 
991 /*
992  * Maximal mount counts between two filesystem checks
993  */
994 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
995 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
996 
997 /*
998  * Behaviour when detecting errors
999  */
1000 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
1001 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
1002 #define EXT4_ERRORS_PANIC		3	/* Panic */
1003 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
1004 
1005 /* Metadata checksum algorithm codes */
1006 #define EXT4_CRC32C_CHKSUM		1
1007 
1008 /*
1009  * Structure of the super block
1010  */
1011 struct ext4_super_block {
1012 /*00*/	__le32	s_inodes_count;		/* Inodes count */
1013 	__le32	s_blocks_count_lo;	/* Blocks count */
1014 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
1015 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
1016 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
1017 	__le32	s_first_data_block;	/* First Data Block */
1018 	__le32	s_log_block_size;	/* Block size */
1019 	__le32	s_log_cluster_size;	/* Allocation cluster size */
1020 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
1021 	__le32	s_clusters_per_group;	/* # Clusters per group */
1022 	__le32	s_inodes_per_group;	/* # Inodes per group */
1023 	__le32	s_mtime;		/* Mount time */
1024 /*30*/	__le32	s_wtime;		/* Write time */
1025 	__le16	s_mnt_count;		/* Mount count */
1026 	__le16	s_max_mnt_count;	/* Maximal mount count */
1027 	__le16	s_magic;		/* Magic signature */
1028 	__le16	s_state;		/* File system state */
1029 	__le16	s_errors;		/* Behaviour when detecting errors */
1030 	__le16	s_minor_rev_level;	/* minor revision level */
1031 /*40*/	__le32	s_lastcheck;		/* time of last check */
1032 	__le32	s_checkinterval;	/* max. time between checks */
1033 	__le32	s_creator_os;		/* OS */
1034 	__le32	s_rev_level;		/* Revision level */
1035 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
1036 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
1037 	/*
1038 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
1039 	 *
1040 	 * Note: the difference between the compatible feature set and
1041 	 * the incompatible feature set is that if there is a bit set
1042 	 * in the incompatible feature set that the kernel doesn't
1043 	 * know about, it should refuse to mount the filesystem.
1044 	 *
1045 	 * e2fsck's requirements are more strict; if it doesn't know
1046 	 * about a feature in either the compatible or incompatible
1047 	 * feature set, it must abort and not try to meddle with
1048 	 * things it doesn't understand...
1049 	 */
1050 	__le32	s_first_ino;		/* First non-reserved inode */
1051 	__le16  s_inode_size;		/* size of inode structure */
1052 	__le16	s_block_group_nr;	/* block group # of this superblock */
1053 	__le32	s_feature_compat;	/* compatible feature set */
1054 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
1055 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
1056 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
1057 /*78*/	char	s_volume_name[16];	/* volume name */
1058 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
1059 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
1060 	/*
1061 	 * Performance hints.  Directory preallocation should only
1062 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1063 	 */
1064 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
1065 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
1066 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
1067 	/*
1068 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1069 	 */
1070 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
1071 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
1072 	__le32	s_journal_dev;		/* device number of journal file */
1073 	__le32	s_last_orphan;		/* start of list of inodes to delete */
1074 	__le32	s_hash_seed[4];		/* HTREE hash seed */
1075 	__u8	s_def_hash_version;	/* Default hash version to use */
1076 	__u8	s_jnl_backup_type;
1077 	__le16  s_desc_size;		/* size of group descriptor */
1078 /*100*/	__le32	s_default_mount_opts;
1079 	__le32	s_first_meta_bg;	/* First metablock block group */
1080 	__le32	s_mkfs_time;		/* When the filesystem was created */
1081 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
1082 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1083 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
1084 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
1085 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
1086 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
1087 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
1088 	__le32	s_flags;		/* Miscellaneous flags */
1089 	__le16  s_raid_stride;		/* RAID stride */
1090 	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1091 	__le64  s_mmp_block;            /* Block for multi-mount protection */
1092 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1093 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
1094 	__u8	s_checksum_type;	/* metadata checksum algorithm used */
1095 	__le16  s_reserved_pad;
1096 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1097 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
1098 	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
1099 	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
1100 					      snapshot's future use */
1101 	__le32	s_snapshot_list;	/* inode number of the head of the
1102 					   on-disk snapshot list */
1103 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1104 	__le32	s_error_count;		/* number of fs errors */
1105 	__le32	s_first_error_time;	/* first time an error happened */
1106 	__le32	s_first_error_ino;	/* inode involved in first error */
1107 	__le64	s_first_error_block;	/* block involved of first error */
1108 	__u8	s_first_error_func[32];	/* function where the error happened */
1109 	__le32	s_first_error_line;	/* line number where error happened */
1110 	__le32	s_last_error_time;	/* most recent time of an error */
1111 	__le32	s_last_error_ino;	/* inode involved in last error */
1112 	__le32	s_last_error_line;	/* line number where error happened */
1113 	__le64	s_last_error_block;	/* block involved of last error */
1114 	__u8	s_last_error_func[32];	/* function where the error happened */
1115 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1116 	__u8	s_mount_opts[64];
1117 	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
1118 	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
1119 	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
1120 	__le32	s_reserved[108];	/* Padding to the end of the block */
1121 	__le32	s_checksum;		/* crc32c(superblock) */
1122 };
1123 
1124 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1125 
1126 #ifdef __KERNEL__
1127 
1128 /*
1129  * run-time mount flags
1130  */
1131 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
1132 #define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
1133 
1134 /*
1135  * fourth extended-fs super-block data in memory
1136  */
1137 struct ext4_sb_info {
1138 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
1139 	unsigned long s_inodes_per_block;/* Number of inodes per block */
1140 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
1141 	unsigned long s_clusters_per_group; /* Number of clusters in a group */
1142 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
1143 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
1144 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
1145 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
1146 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1147 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1148 	unsigned long s_overhead;  /* # of fs overhead clusters */
1149 	unsigned int s_cluster_ratio;	/* Number of blocks per cluster */
1150 	unsigned int s_cluster_bits;	/* log2 of s_cluster_ratio */
1151 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
1152 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
1153 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
1154 	struct buffer_head **s_group_desc;
1155 	unsigned int s_mount_opt;
1156 	unsigned int s_mount_opt2;
1157 	unsigned int s_mount_flags;
1158 	unsigned int s_def_mount_opt;
1159 	ext4_fsblk_t s_sb_block;
1160 	atomic64_t s_resv_clusters;
1161 	kuid_t s_resuid;
1162 	kgid_t s_resgid;
1163 	unsigned short s_mount_state;
1164 	unsigned short s_pad;
1165 	int s_addr_per_block_bits;
1166 	int s_desc_per_block_bits;
1167 	int s_inode_size;
1168 	int s_first_ino;
1169 	unsigned int s_inode_readahead_blks;
1170 	unsigned int s_inode_goal;
1171 	spinlock_t s_next_gen_lock;
1172 	u32 s_next_generation;
1173 	u32 s_hash_seed[4];
1174 	int s_def_hash_version;
1175 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
1176 	struct percpu_counter s_freeclusters_counter;
1177 	struct percpu_counter s_freeinodes_counter;
1178 	struct percpu_counter s_dirs_counter;
1179 	struct percpu_counter s_dirtyclusters_counter;
1180 	struct blockgroup_lock *s_blockgroup_lock;
1181 	struct proc_dir_entry *s_proc;
1182 	struct kobject s_kobj;
1183 	struct completion s_kobj_unregister;
1184 	struct super_block *s_sb;
1185 
1186 	/* Journaling */
1187 	struct journal_s *s_journal;
1188 	struct list_head s_orphan;
1189 	struct mutex s_orphan_lock;
1190 	unsigned long s_resize_flags;		/* Flags indicating if there
1191 						   is a resizer */
1192 	unsigned long s_commit_interval;
1193 	u32 s_max_batch_time;
1194 	u32 s_min_batch_time;
1195 	struct block_device *journal_bdev;
1196 #ifdef CONFIG_QUOTA
1197 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
1198 	int s_jquota_fmt;			/* Format of quota to use */
1199 #endif
1200 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1201 	struct rb_root system_blks;
1202 
1203 #ifdef EXTENTS_STATS
1204 	/* ext4 extents stats */
1205 	unsigned long s_ext_min;
1206 	unsigned long s_ext_max;
1207 	unsigned long s_depth_max;
1208 	spinlock_t s_ext_stats_lock;
1209 	unsigned long s_ext_blocks;
1210 	unsigned long s_ext_extents;
1211 #endif
1212 
1213 	/* for buddy allocator */
1214 	struct ext4_group_info ***s_group_info;
1215 	struct inode *s_buddy_cache;
1216 	spinlock_t s_md_lock;
1217 	unsigned short *s_mb_offsets;
1218 	unsigned int *s_mb_maxs;
1219 	unsigned int s_group_info_size;
1220 
1221 	/* tunables */
1222 	unsigned long s_stripe;
1223 	unsigned int s_mb_stream_request;
1224 	unsigned int s_mb_max_to_scan;
1225 	unsigned int s_mb_min_to_scan;
1226 	unsigned int s_mb_stats;
1227 	unsigned int s_mb_order2_reqs;
1228 	unsigned int s_mb_group_prealloc;
1229 	unsigned int s_max_dir_size_kb;
1230 	/* where last allocation was done - for stream allocation */
1231 	unsigned long s_mb_last_group;
1232 	unsigned long s_mb_last_start;
1233 
1234 	/* stats for buddy allocator */
1235 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1236 	atomic_t s_bal_success;	/* we found long enough chunks */
1237 	atomic_t s_bal_allocated;	/* in blocks */
1238 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1239 	atomic_t s_bal_goals;	/* goal hits */
1240 	atomic_t s_bal_breaks;	/* too long searches */
1241 	atomic_t s_bal_2orders;	/* 2^order hits */
1242 	spinlock_t s_bal_lock;
1243 	unsigned long s_mb_buddies_generated;
1244 	unsigned long long s_mb_generation_time;
1245 	atomic_t s_mb_lost_chunks;
1246 	atomic_t s_mb_preallocated;
1247 	atomic_t s_mb_discarded;
1248 	atomic_t s_lock_busy;
1249 
1250 	/* locality groups */
1251 	struct ext4_locality_group __percpu *s_locality_groups;
1252 
1253 	/* for write statistics */
1254 	unsigned long s_sectors_written_start;
1255 	u64 s_kbytes_written;
1256 
1257 	/* the size of zero-out chunk */
1258 	unsigned int s_extent_max_zeroout_kb;
1259 
1260 	unsigned int s_log_groups_per_flex;
1261 	struct flex_groups *s_flex_groups;
1262 	ext4_group_t s_flex_groups_allocated;
1263 
1264 	/* workqueue for dio unwritten */
1265 	struct workqueue_struct *dio_unwritten_wq;
1266 
1267 	/* timer for periodic error stats printing */
1268 	struct timer_list s_err_report;
1269 
1270 	/* Lazy inode table initialization info */
1271 	struct ext4_li_request *s_li_request;
1272 	/* Wait multiplier for lazy initialization thread */
1273 	unsigned int s_li_wait_mult;
1274 
1275 	/* Kernel thread for multiple mount protection */
1276 	struct task_struct *s_mmp_tsk;
1277 
1278 	/* record the last minlen when FITRIM is called. */
1279 	atomic_t s_last_trim_minblks;
1280 
1281 	/* Reference to checksum algorithm driver via cryptoapi */
1282 	struct crypto_shash *s_chksum_driver;
1283 
1284 	/* Precomputed FS UUID checksum for seeding other checksums */
1285 	__u32 s_csum_seed;
1286 
1287 	/* Reclaim extents from extent status tree */
1288 	struct shrinker s_es_shrinker;
1289 	struct list_head s_es_lru;
1290 	struct percpu_counter s_extent_cache_cnt;
1291 	spinlock_t s_es_lru_lock ____cacheline_aligned_in_smp;
1292 };
1293 
1294 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1295 {
1296 	return sb->s_fs_info;
1297 }
1298 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1299 {
1300 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1301 }
1302 
1303 static inline struct timespec ext4_current_time(struct inode *inode)
1304 {
1305 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1306 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1307 }
1308 
1309 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1310 {
1311 	return ino == EXT4_ROOT_INO ||
1312 		ino == EXT4_USR_QUOTA_INO ||
1313 		ino == EXT4_GRP_QUOTA_INO ||
1314 		ino == EXT4_BOOT_LOADER_INO ||
1315 		ino == EXT4_JOURNAL_INO ||
1316 		ino == EXT4_RESIZE_INO ||
1317 		(ino >= EXT4_FIRST_INO(sb) &&
1318 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1319 }
1320 
1321 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1322 					      struct ext4_io_end *io_end)
1323 {
1324 	if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1325 		io_end->flag |= EXT4_IO_END_UNWRITTEN;
1326 		atomic_inc(&EXT4_I(inode)->i_unwritten);
1327 	}
1328 }
1329 
1330 static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode)
1331 {
1332 	return inode->i_private;
1333 }
1334 
1335 static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io)
1336 {
1337 	inode->i_private = io;
1338 }
1339 
1340 /*
1341  * Inode dynamic state flags
1342  */
1343 enum {
1344 	EXT4_STATE_JDATA,		/* journaled data exists */
1345 	EXT4_STATE_NEW,			/* inode is newly created */
1346 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1347 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1348 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1349 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1350 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1351 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1352 	EXT4_STATE_DELALLOC_RESERVED,	/* blks already reserved for delalloc */
1353 	EXT4_STATE_DIOREAD_LOCK,	/* Disable support for dio read
1354 					   nolocking */
1355 	EXT4_STATE_MAY_INLINE_DATA,	/* may have in-inode data */
1356 	EXT4_STATE_ORDERED_MODE,	/* data=ordered mode */
1357 };
1358 
1359 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
1360 static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
1361 {									\
1362 	return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);	\
1363 }									\
1364 static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
1365 {									\
1366 	set_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1367 }									\
1368 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1369 {									\
1370 	clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1371 }
1372 
1373 EXT4_INODE_BIT_FNS(flag, flags, 0)
1374 #if (BITS_PER_LONG < 64)
1375 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1376 
1377 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1378 {
1379 	(ei)->i_state_flags = 0;
1380 }
1381 #else
1382 EXT4_INODE_BIT_FNS(state, flags, 32)
1383 
1384 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1385 {
1386 	/* We depend on the fact that callers will set i_flags */
1387 }
1388 #endif
1389 #else
1390 /* Assume that user mode programs are passing in an ext4fs superblock, not
1391  * a kernel struct super_block.  This will allow us to call the feature-test
1392  * macros from user land. */
1393 #define EXT4_SB(sb)	(sb)
1394 #endif
1395 
1396 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1397 
1398 /*
1399  * Codes for operating systems
1400  */
1401 #define EXT4_OS_LINUX		0
1402 #define EXT4_OS_HURD		1
1403 #define EXT4_OS_MASIX		2
1404 #define EXT4_OS_FREEBSD		3
1405 #define EXT4_OS_LITES		4
1406 
1407 /*
1408  * Revision levels
1409  */
1410 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1411 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1412 
1413 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1414 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1415 
1416 #define EXT4_GOOD_OLD_INODE_SIZE 128
1417 
1418 /*
1419  * Feature set definitions
1420  */
1421 
1422 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1423 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1424 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1425 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1426 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1427 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1428 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1429 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1430 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1431 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1432 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1433 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1434 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1435 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1436 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1437 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1438 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1439 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1440 
1441 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1442 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1443 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1444 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1445 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1446 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1447 
1448 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1449 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1450 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1451 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1452 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1453 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1454 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1455 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
1456 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
1457 /*
1458  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1459  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1460  * all other data structures' checksums.  However, the METADATA_CSUM and
1461  * GDT_CSUM bits are mutually exclusive.
1462  */
1463 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
1464 
1465 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1466 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1467 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1468 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1469 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1470 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1471 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1472 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1473 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1474 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1475 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1476 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM	0x2000 /* use crc32c for bg */
1477 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
1478 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA	0x8000 /* data in inode */
1479 
1480 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1481 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1482 					 EXT4_FEATURE_INCOMPAT_META_BG)
1483 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1484 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1485 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1486 
1487 #define EXT3_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1488 #define EXT3_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1489 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1490 					 EXT4_FEATURE_INCOMPAT_META_BG)
1491 #define EXT3_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1492 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1493 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1494 
1495 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1496 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1497 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1498 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1499 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1500 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1501 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1502 					 EXT4_FEATURE_INCOMPAT_MMP |	\
1503 					 EXT4_FEATURE_INCOMPAT_INLINE_DATA)
1504 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1505 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1506 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1507 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1508 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1509 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1510 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1511 					 EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1512 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1513 					 EXT4_FEATURE_RO_COMPAT_QUOTA)
1514 
1515 /*
1516  * Default values for user and/or group using reserved blocks
1517  */
1518 #define	EXT4_DEF_RESUID		0
1519 #define	EXT4_DEF_RESGID		0
1520 
1521 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1522 
1523 /*
1524  * Default mount options
1525  */
1526 #define EXT4_DEFM_DEBUG		0x0001
1527 #define EXT4_DEFM_BSDGROUPS	0x0002
1528 #define EXT4_DEFM_XATTR_USER	0x0004
1529 #define EXT4_DEFM_ACL		0x0008
1530 #define EXT4_DEFM_UID16		0x0010
1531 #define EXT4_DEFM_JMODE		0x0060
1532 #define EXT4_DEFM_JMODE_DATA	0x0020
1533 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1534 #define EXT4_DEFM_JMODE_WBACK	0x0060
1535 #define EXT4_DEFM_NOBARRIER	0x0100
1536 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1537 #define EXT4_DEFM_DISCARD	0x0400
1538 #define EXT4_DEFM_NODELALLOC	0x0800
1539 
1540 /*
1541  * Default journal batch times
1542  */
1543 #define EXT4_DEF_MIN_BATCH_TIME	0
1544 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1545 
1546 /*
1547  * Minimum number of groups in a flexgroup before we separate out
1548  * directories into the first block group of a flexgroup
1549  */
1550 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1551 
1552 /*
1553  * Structure of a directory entry
1554  */
1555 #define EXT4_NAME_LEN 255
1556 
1557 struct ext4_dir_entry {
1558 	__le32	inode;			/* Inode number */
1559 	__le16	rec_len;		/* Directory entry length */
1560 	__le16	name_len;		/* Name length */
1561 	char	name[EXT4_NAME_LEN];	/* File name */
1562 };
1563 
1564 /*
1565  * The new version of the directory entry.  Since EXT4 structures are
1566  * stored in intel byte order, and the name_len field could never be
1567  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1568  * file_type field.
1569  */
1570 struct ext4_dir_entry_2 {
1571 	__le32	inode;			/* Inode number */
1572 	__le16	rec_len;		/* Directory entry length */
1573 	__u8	name_len;		/* Name length */
1574 	__u8	file_type;
1575 	char	name[EXT4_NAME_LEN];	/* File name */
1576 };
1577 
1578 /*
1579  * This is a bogus directory entry at the end of each leaf block that
1580  * records checksums.
1581  */
1582 struct ext4_dir_entry_tail {
1583 	__le32	det_reserved_zero1;	/* Pretend to be unused */
1584 	__le16	det_rec_len;		/* 12 */
1585 	__u8	det_reserved_zero2;	/* Zero name length */
1586 	__u8	det_reserved_ft;	/* 0xDE, fake file type */
1587 	__le32	det_checksum;		/* crc32c(uuid+inum+dirblock) */
1588 };
1589 
1590 #define EXT4_DIRENT_TAIL(block, blocksize) \
1591 	((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1592 					((blocksize) - \
1593 					 sizeof(struct ext4_dir_entry_tail))))
1594 
1595 /*
1596  * Ext4 directory file types.  Only the low 3 bits are used.  The
1597  * other bits are reserved for now.
1598  */
1599 #define EXT4_FT_UNKNOWN		0
1600 #define EXT4_FT_REG_FILE	1
1601 #define EXT4_FT_DIR		2
1602 #define EXT4_FT_CHRDEV		3
1603 #define EXT4_FT_BLKDEV		4
1604 #define EXT4_FT_FIFO		5
1605 #define EXT4_FT_SOCK		6
1606 #define EXT4_FT_SYMLINK		7
1607 
1608 #define EXT4_FT_MAX		8
1609 
1610 #define EXT4_FT_DIR_CSUM	0xDE
1611 
1612 /*
1613  * EXT4_DIR_PAD defines the directory entries boundaries
1614  *
1615  * NOTE: It must be a multiple of 4
1616  */
1617 #define EXT4_DIR_PAD			4
1618 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1619 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1620 					 ~EXT4_DIR_ROUND)
1621 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1622 
1623 /*
1624  * If we ever get support for fs block sizes > page_size, we'll need
1625  * to remove the #if statements in the next two functions...
1626  */
1627 static inline unsigned int
1628 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1629 {
1630 	unsigned len = le16_to_cpu(dlen);
1631 
1632 #if (PAGE_CACHE_SIZE >= 65536)
1633 	if (len == EXT4_MAX_REC_LEN || len == 0)
1634 		return blocksize;
1635 	return (len & 65532) | ((len & 3) << 16);
1636 #else
1637 	return len;
1638 #endif
1639 }
1640 
1641 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1642 {
1643 	if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1644 		BUG();
1645 #if (PAGE_CACHE_SIZE >= 65536)
1646 	if (len < 65536)
1647 		return cpu_to_le16(len);
1648 	if (len == blocksize) {
1649 		if (blocksize == 65536)
1650 			return cpu_to_le16(EXT4_MAX_REC_LEN);
1651 		else
1652 			return cpu_to_le16(0);
1653 	}
1654 	return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1655 #else
1656 	return cpu_to_le16(len);
1657 #endif
1658 }
1659 
1660 /*
1661  * Hash Tree Directory indexing
1662  * (c) Daniel Phillips, 2001
1663  */
1664 
1665 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1666 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1667 		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1668 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1669 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1670 
1671 /* Legal values for the dx_root hash_version field: */
1672 
1673 #define DX_HASH_LEGACY		0
1674 #define DX_HASH_HALF_MD4	1
1675 #define DX_HASH_TEA		2
1676 #define DX_HASH_LEGACY_UNSIGNED	3
1677 #define DX_HASH_HALF_MD4_UNSIGNED	4
1678 #define DX_HASH_TEA_UNSIGNED		5
1679 
1680 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1681 			      const void *address, unsigned int length)
1682 {
1683 	struct {
1684 		struct shash_desc shash;
1685 		char ctx[4];
1686 	} desc;
1687 	int err;
1688 
1689 	BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
1690 
1691 	desc.shash.tfm = sbi->s_chksum_driver;
1692 	desc.shash.flags = 0;
1693 	*(u32 *)desc.ctx = crc;
1694 
1695 	err = crypto_shash_update(&desc.shash, address, length);
1696 	BUG_ON(err);
1697 
1698 	return *(u32 *)desc.ctx;
1699 }
1700 
1701 #ifdef __KERNEL__
1702 
1703 /* hash info structure used by the directory hash */
1704 struct dx_hash_info
1705 {
1706 	u32		hash;
1707 	u32		minor_hash;
1708 	int		hash_version;
1709 	u32		*seed;
1710 };
1711 
1712 
1713 /* 32 and 64 bit signed EOF for dx directories */
1714 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
1715 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
1716 
1717 
1718 /*
1719  * Control parameters used by ext4_htree_next_block
1720  */
1721 #define HASH_NB_ALWAYS		1
1722 
1723 
1724 /*
1725  * Describe an inode's exact location on disk and in memory
1726  */
1727 struct ext4_iloc
1728 {
1729 	struct buffer_head *bh;
1730 	unsigned long offset;
1731 	ext4_group_t block_group;
1732 };
1733 
1734 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1735 {
1736 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1737 }
1738 
1739 /*
1740  * This structure is stuffed into the struct file's private_data field
1741  * for directories.  It is where we put information so that we can do
1742  * readdir operations in hash tree order.
1743  */
1744 struct dir_private_info {
1745 	struct rb_root	root;
1746 	struct rb_node	*curr_node;
1747 	struct fname	*extra_fname;
1748 	loff_t		last_pos;
1749 	__u32		curr_hash;
1750 	__u32		curr_minor_hash;
1751 	__u32		next_hash;
1752 };
1753 
1754 /* calculate the first block number of the group */
1755 static inline ext4_fsblk_t
1756 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1757 {
1758 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1759 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1760 }
1761 
1762 /*
1763  * Special error return code only used by dx_probe() and its callers.
1764  */
1765 #define ERR_BAD_DX_DIR	-75000
1766 
1767 /*
1768  * Timeout and state flag for lazy initialization inode thread.
1769  */
1770 #define EXT4_DEF_LI_WAIT_MULT			10
1771 #define EXT4_DEF_LI_MAX_START_DELAY		5
1772 #define EXT4_LAZYINIT_QUIT			0x0001
1773 #define EXT4_LAZYINIT_RUNNING			0x0002
1774 
1775 /*
1776  * Lazy inode table initialization info
1777  */
1778 struct ext4_lazy_init {
1779 	unsigned long		li_state;
1780 	struct list_head	li_request_list;
1781 	struct mutex		li_list_mtx;
1782 };
1783 
1784 struct ext4_li_request {
1785 	struct super_block	*lr_super;
1786 	struct ext4_sb_info	*lr_sbi;
1787 	ext4_group_t		lr_next_group;
1788 	struct list_head	lr_request;
1789 	unsigned long		lr_next_sched;
1790 	unsigned long		lr_timeout;
1791 };
1792 
1793 struct ext4_features {
1794 	struct kobject f_kobj;
1795 	struct completion f_kobj_unregister;
1796 };
1797 
1798 /*
1799  * This structure will be used for multiple mount protection. It will be
1800  * written into the block number saved in the s_mmp_block field in the
1801  * superblock. Programs that check MMP should assume that if
1802  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1803  * to use the filesystem, regardless of how old the timestamp is.
1804  */
1805 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1806 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1807 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1808 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1809 
1810 struct mmp_struct {
1811 	__le32	mmp_magic;		/* Magic number for MMP */
1812 	__le32	mmp_seq;		/* Sequence no. updated periodically */
1813 
1814 	/*
1815 	 * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1816 	 * purposes and do not affect the correctness of the algorithm
1817 	 */
1818 	__le64	mmp_time;		/* Time last updated */
1819 	char	mmp_nodename[64];	/* Node which last updated MMP block */
1820 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
1821 
1822 	/*
1823 	 * mmp_check_interval is used to verify if the MMP block has been
1824 	 * updated on the block device. The value is updated based on the
1825 	 * maximum time to write the MMP block during an update cycle.
1826 	 */
1827 	__le16	mmp_check_interval;
1828 
1829 	__le16	mmp_pad1;
1830 	__le32	mmp_pad2[226];
1831 	__le32	mmp_checksum;		/* crc32c(uuid+mmp_block) */
1832 };
1833 
1834 /* arguments passed to the mmp thread */
1835 struct mmpd_data {
1836 	struct buffer_head *bh; /* bh from initial read_mmp_block() */
1837 	struct super_block *sb;  /* super block of the fs */
1838 };
1839 
1840 /*
1841  * Check interval multiplier
1842  * The MMP block is written every update interval and initially checked every
1843  * update interval x the multiplier (the value is then adapted based on the
1844  * write latency). The reason is that writes can be delayed under load and we
1845  * don't want readers to incorrectly assume that the filesystem is no longer
1846  * in use.
1847  */
1848 #define EXT4_MMP_CHECK_MULT		2UL
1849 
1850 /*
1851  * Minimum interval for MMP checking in seconds.
1852  */
1853 #define EXT4_MMP_MIN_CHECK_INTERVAL	5UL
1854 
1855 /*
1856  * Maximum interval for MMP checking in seconds.
1857  */
1858 #define EXT4_MMP_MAX_CHECK_INTERVAL	300UL
1859 
1860 /*
1861  * Function prototypes
1862  */
1863 
1864 /*
1865  * Ok, these declarations are also in <linux/kernel.h> but none of the
1866  * ext4 source programs needs to include it so they are duplicated here.
1867  */
1868 # define NORET_TYPE	/**/
1869 # define ATTRIB_NORET	__attribute__((noreturn))
1870 # define NORET_AND	noreturn,
1871 
1872 /* bitmap.c */
1873 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
1874 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1875 				struct ext4_group_desc *gdp,
1876 				struct buffer_head *bh, int sz);
1877 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1878 				  struct ext4_group_desc *gdp,
1879 				  struct buffer_head *bh, int sz);
1880 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1881 				struct ext4_group_desc *gdp,
1882 				struct buffer_head *bh);
1883 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1884 				  struct ext4_group_desc *gdp,
1885 				  struct buffer_head *bh);
1886 
1887 /* balloc.c */
1888 extern void ext4_get_group_no_and_offset(struct super_block *sb,
1889 					 ext4_fsblk_t blocknr,
1890 					 ext4_group_t *blockgrpp,
1891 					 ext4_grpblk_t *offsetp);
1892 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
1893 					  ext4_fsblk_t block);
1894 
1895 extern void ext4_validate_block_bitmap(struct super_block *sb,
1896 				       struct ext4_group_desc *desc,
1897 				       unsigned int block_group,
1898 				       struct buffer_head *bh);
1899 extern unsigned int ext4_block_group(struct super_block *sb,
1900 			ext4_fsblk_t blocknr);
1901 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1902 			ext4_fsblk_t blocknr);
1903 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1904 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1905 			ext4_group_t group);
1906 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1907 					 ext4_fsblk_t goal,
1908 					 unsigned int flags,
1909 					 unsigned long *count,
1910 					 int *errp);
1911 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1912 				    s64 nclusters, unsigned int flags);
1913 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1914 extern void ext4_check_blocks_bitmap(struct super_block *);
1915 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1916 						    ext4_group_t block_group,
1917 						    struct buffer_head ** bh);
1918 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1919 
1920 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1921 						ext4_group_t block_group);
1922 extern int ext4_wait_block_bitmap(struct super_block *sb,
1923 				  ext4_group_t block_group,
1924 				  struct buffer_head *bh);
1925 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1926 						  ext4_group_t block_group);
1927 extern void ext4_init_block_bitmap(struct super_block *sb,
1928 				   struct buffer_head *bh,
1929 				   ext4_group_t group,
1930 				   struct ext4_group_desc *desc);
1931 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1932 					      ext4_group_t block_group,
1933 					      struct ext4_group_desc *gdp);
1934 extern unsigned ext4_num_overhead_clusters(struct super_block *sb,
1935 					   ext4_group_t block_group,
1936 					   struct ext4_group_desc *gdp);
1937 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1938 
1939 /* dir.c */
1940 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1941 				  struct file *,
1942 				  struct ext4_dir_entry_2 *,
1943 				  struct buffer_head *, char *, int,
1944 				  unsigned int);
1945 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)	\
1946 	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1947 					(de), (bh), (buf), (size), (offset)))
1948 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1949 				    __u32 minor_hash,
1950 				    struct ext4_dir_entry_2 *dirent);
1951 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1952 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1953 			     struct buffer_head *bh,
1954 			     void *buf, int buf_size,
1955 			     const char *name, int namelen,
1956 			     struct ext4_dir_entry_2 **dest_de);
1957 void ext4_insert_dentry(struct inode *inode,
1958 			struct ext4_dir_entry_2 *de,
1959 			int buf_size,
1960 			const char *name, int namelen);
1961 static inline void ext4_update_dx_flag(struct inode *inode)
1962 {
1963 	if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
1964 				     EXT4_FEATURE_COMPAT_DIR_INDEX))
1965 		ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
1966 }
1967 static unsigned char ext4_filetype_table[] = {
1968 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1969 };
1970 
1971 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
1972 {
1973 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
1974 	    (filetype >= EXT4_FT_MAX))
1975 		return DT_UNKNOWN;
1976 
1977 	return ext4_filetype_table[filetype];
1978 }
1979 
1980 /* fsync.c */
1981 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
1982 extern int ext4_flush_unwritten_io(struct inode *);
1983 
1984 /* hash.c */
1985 extern int ext4fs_dirhash(const char *name, int len, struct
1986 			  dx_hash_info *hinfo);
1987 
1988 /* ialloc.c */
1989 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
1990 				      const struct qstr *qstr, __u32 goal,
1991 				      uid_t *owner, int handle_type,
1992 				      unsigned int line_no, int nblocks);
1993 
1994 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner) \
1995 	__ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
1996 			 0, 0, 0)
1997 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
1998 				    type, nblocks)		    \
1999 	__ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
2000 			 (type), __LINE__, (nblocks))
2001 
2002 
2003 extern void ext4_free_inode(handle_t *, struct inode *);
2004 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2005 extern unsigned long ext4_count_free_inodes(struct super_block *);
2006 extern unsigned long ext4_count_dirs(struct super_block *);
2007 extern void ext4_check_inodes_bitmap(struct super_block *);
2008 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2009 extern int ext4_init_inode_table(struct super_block *sb,
2010 				 ext4_group_t group, int barrier);
2011 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2012 
2013 /* mballoc.c */
2014 extern long ext4_mb_stats;
2015 extern long ext4_mb_max_to_scan;
2016 extern int ext4_mb_init(struct super_block *);
2017 extern int ext4_mb_release(struct super_block *);
2018 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2019 				struct ext4_allocation_request *, int *);
2020 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2021 extern void ext4_discard_preallocations(struct inode *);
2022 extern int __init ext4_init_mballoc(void);
2023 extern void ext4_exit_mballoc(void);
2024 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2025 			     struct buffer_head *bh, ext4_fsblk_t block,
2026 			     unsigned long count, int flags);
2027 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2028 				   ext4_group_t ngroups);
2029 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2030 		ext4_group_t i, struct ext4_group_desc *desc);
2031 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2032 				ext4_fsblk_t block, unsigned long count);
2033 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2034 
2035 /* inode.c */
2036 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
2037 						ext4_lblk_t, int, int *);
2038 struct buffer_head *ext4_bread(handle_t *, struct inode *,
2039 						ext4_lblk_t, int, int *);
2040 int ext4_get_block_write(struct inode *inode, sector_t iblock,
2041 			 struct buffer_head *bh_result, int create);
2042 int ext4_get_block(struct inode *inode, sector_t iblock,
2043 				struct buffer_head *bh_result, int create);
2044 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2045 			   struct buffer_head *bh, int create);
2046 int ext4_walk_page_buffers(handle_t *handle,
2047 			   struct buffer_head *head,
2048 			   unsigned from,
2049 			   unsigned to,
2050 			   int *partial,
2051 			   int (*fn)(handle_t *handle,
2052 				     struct buffer_head *bh));
2053 int do_journal_get_write_access(handle_t *handle,
2054 				struct buffer_head *bh);
2055 #define FALL_BACK_TO_NONDELALLOC 1
2056 #define CONVERT_INLINE_DATA	 2
2057 
2058 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2059 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2060 extern int  ext4_setattr(struct dentry *, struct iattr *);
2061 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
2062 				struct kstat *stat);
2063 extern void ext4_evict_inode(struct inode *);
2064 extern void ext4_clear_inode(struct inode *);
2065 extern int  ext4_sync_inode(handle_t *, struct inode *);
2066 extern void ext4_dirty_inode(struct inode *, int);
2067 extern int ext4_change_inode_journal_flag(struct inode *, int);
2068 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2069 extern int ext4_can_truncate(struct inode *inode);
2070 extern void ext4_truncate(struct inode *);
2071 extern int ext4_punch_hole(struct file *file, loff_t offset, loff_t length);
2072 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2073 extern void ext4_set_inode_flags(struct inode *);
2074 extern void ext4_get_inode_flags(struct ext4_inode_info *);
2075 extern int ext4_alloc_da_blocks(struct inode *inode);
2076 extern void ext4_set_aops(struct inode *inode);
2077 extern int ext4_writepage_trans_blocks(struct inode *);
2078 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2079 extern int ext4_block_truncate_page(handle_t *handle,
2080 		struct address_space *mapping, loff_t from);
2081 extern int ext4_block_zero_page_range(handle_t *handle,
2082 		struct address_space *mapping, loff_t from, loff_t length);
2083 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
2084 			     loff_t lstart, loff_t lend);
2085 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2086 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2087 extern void ext4_da_update_reserve_space(struct inode *inode,
2088 					int used, int quota_claim);
2089 
2090 /* indirect.c */
2091 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2092 				struct ext4_map_blocks *map, int flags);
2093 extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
2094 				const struct iovec *iov, loff_t offset,
2095 				unsigned long nr_segs);
2096 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2097 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2098 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2099 extern int ext4_free_hole_blocks(handle_t *handle, struct inode *inode,
2100 				 ext4_lblk_t first, ext4_lblk_t stop);
2101 
2102 /* ioctl.c */
2103 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2104 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2105 
2106 /* migrate.c */
2107 extern int ext4_ext_migrate(struct inode *);
2108 extern int ext4_ind_migrate(struct inode *inode);
2109 
2110 /* namei.c */
2111 extern int ext4_dirent_csum_verify(struct inode *inode,
2112 				   struct ext4_dir_entry *dirent);
2113 extern int ext4_orphan_add(handle_t *, struct inode *);
2114 extern int ext4_orphan_del(handle_t *, struct inode *);
2115 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2116 				__u32 start_minor_hash, __u32 *next_hash);
2117 extern int search_dir(struct buffer_head *bh,
2118 		      char *search_buf,
2119 		      int buf_size,
2120 		      struct inode *dir,
2121 		      const struct qstr *d_name,
2122 		      unsigned int offset,
2123 		      struct ext4_dir_entry_2 **res_dir);
2124 extern int ext4_generic_delete_entry(handle_t *handle,
2125 				     struct inode *dir,
2126 				     struct ext4_dir_entry_2 *de_del,
2127 				     struct buffer_head *bh,
2128 				     void *entry_buf,
2129 				     int buf_size,
2130 				     int csum_size);
2131 
2132 /* resize.c */
2133 extern int ext4_group_add(struct super_block *sb,
2134 				struct ext4_new_group_data *input);
2135 extern int ext4_group_extend(struct super_block *sb,
2136 				struct ext4_super_block *es,
2137 				ext4_fsblk_t n_blocks_count);
2138 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2139 
2140 /* super.c */
2141 extern int ext4_calculate_overhead(struct super_block *sb);
2142 extern int ext4_superblock_csum_verify(struct super_block *sb,
2143 				       struct ext4_super_block *es);
2144 extern void ext4_superblock_csum_set(struct super_block *sb);
2145 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2146 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2147 extern void ext4_kvfree(void *ptr);
2148 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2149 				    ext4_group_t ngroup);
2150 extern const char *ext4_decode_error(struct super_block *sb, int errno,
2151 				     char nbuf[16]);
2152 extern __printf(4, 5)
2153 void __ext4_error(struct super_block *, const char *, unsigned int,
2154 		  const char *, ...);
2155 #define ext4_error(sb, message...)	__ext4_error(sb, __func__,	\
2156 						     __LINE__, ## message)
2157 extern __printf(5, 6)
2158 void ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2159 		      const char *, ...);
2160 extern __printf(5, 6)
2161 void ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2162 		     const char *, ...);
2163 extern void __ext4_std_error(struct super_block *, const char *,
2164 			     unsigned int, int);
2165 extern __printf(4, 5)
2166 void __ext4_abort(struct super_block *, const char *, unsigned int,
2167 		  const char *, ...);
2168 #define ext4_abort(sb, message...)	__ext4_abort(sb, __func__, \
2169 						       __LINE__, ## message)
2170 extern __printf(4, 5)
2171 void __ext4_warning(struct super_block *, const char *, unsigned int,
2172 		    const char *, ...);
2173 #define ext4_warning(sb, message...)	__ext4_warning(sb, __func__, \
2174 						       __LINE__, ## message)
2175 extern __printf(3, 4)
2176 void ext4_msg(struct super_block *, const char *, const char *, ...);
2177 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2178 			   const char *, unsigned int, const char *);
2179 #define dump_mmp_msg(sb, mmp, msg)	__dump_mmp_msg(sb, mmp, __func__, \
2180 						       __LINE__, msg)
2181 extern __printf(7, 8)
2182 void __ext4_grp_locked_error(const char *, unsigned int,
2183 			     struct super_block *, ext4_group_t,
2184 			     unsigned long, ext4_fsblk_t,
2185 			     const char *, ...);
2186 #define ext4_grp_locked_error(sb, grp, message...) \
2187 	__ext4_grp_locked_error(__func__, __LINE__, (sb), (grp), ## message)
2188 extern void ext4_update_dynamic_rev(struct super_block *sb);
2189 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2190 					__u32 compat);
2191 extern int ext4_update_rocompat_feature(handle_t *handle,
2192 					struct super_block *sb,	__u32 rocompat);
2193 extern int ext4_update_incompat_feature(handle_t *handle,
2194 					struct super_block *sb,	__u32 incompat);
2195 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2196 				      struct ext4_group_desc *bg);
2197 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2198 				      struct ext4_group_desc *bg);
2199 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2200 				     struct ext4_group_desc *bg);
2201 extern __u32 ext4_free_group_clusters(struct super_block *sb,
2202 				      struct ext4_group_desc *bg);
2203 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2204 				 struct ext4_group_desc *bg);
2205 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2206 				struct ext4_group_desc *bg);
2207 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2208 				   struct ext4_group_desc *bg);
2209 extern void ext4_block_bitmap_set(struct super_block *sb,
2210 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2211 extern void ext4_inode_bitmap_set(struct super_block *sb,
2212 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2213 extern void ext4_inode_table_set(struct super_block *sb,
2214 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
2215 extern void ext4_free_group_clusters_set(struct super_block *sb,
2216 					 struct ext4_group_desc *bg,
2217 					 __u32 count);
2218 extern void ext4_free_inodes_set(struct super_block *sb,
2219 				struct ext4_group_desc *bg, __u32 count);
2220 extern void ext4_used_dirs_set(struct super_block *sb,
2221 				struct ext4_group_desc *bg, __u32 count);
2222 extern void ext4_itable_unused_set(struct super_block *sb,
2223 				   struct ext4_group_desc *bg, __u32 count);
2224 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2225 				       struct ext4_group_desc *gdp);
2226 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2227 				     struct ext4_group_desc *gdp);
2228 extern int ext4_register_li_request(struct super_block *sb,
2229 				    ext4_group_t first_not_zeroed);
2230 
2231 static inline int ext4_has_group_desc_csum(struct super_block *sb)
2232 {
2233 	return EXT4_HAS_RO_COMPAT_FEATURE(sb,
2234 					  EXT4_FEATURE_RO_COMPAT_GDT_CSUM |
2235 					  EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
2236 }
2237 
2238 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2239 {
2240 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2241 		le32_to_cpu(es->s_blocks_count_lo);
2242 }
2243 
2244 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2245 {
2246 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2247 		le32_to_cpu(es->s_r_blocks_count_lo);
2248 }
2249 
2250 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2251 {
2252 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2253 		le32_to_cpu(es->s_free_blocks_count_lo);
2254 }
2255 
2256 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2257 					 ext4_fsblk_t blk)
2258 {
2259 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2260 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2261 }
2262 
2263 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2264 					      ext4_fsblk_t blk)
2265 {
2266 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2267 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2268 }
2269 
2270 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2271 					   ext4_fsblk_t blk)
2272 {
2273 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2274 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2275 }
2276 
2277 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2278 {
2279 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2280 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2281 			le32_to_cpu(raw_inode->i_size_lo);
2282 	else
2283 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2284 }
2285 
2286 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2287 {
2288 	raw_inode->i_size_lo = cpu_to_le32(i_size);
2289 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2290 }
2291 
2292 static inline
2293 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2294 					    ext4_group_t group)
2295 {
2296 	 struct ext4_group_info ***grp_info;
2297 	 long indexv, indexh;
2298 	 grp_info = EXT4_SB(sb)->s_group_info;
2299 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2300 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2301 	 return grp_info[indexv][indexh];
2302 }
2303 
2304 /*
2305  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2306  * the locking protocol documented in the comments of ext4_group_add()
2307  * in resize.c
2308  */
2309 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2310 {
2311 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
2312 
2313 	smp_rmb();
2314 	return ngroups;
2315 }
2316 
2317 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2318 					     ext4_group_t block_group)
2319 {
2320 	return block_group >> sbi->s_log_groups_per_flex;
2321 }
2322 
2323 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2324 {
2325 	return 1 << sbi->s_log_groups_per_flex;
2326 }
2327 
2328 #define ext4_std_error(sb, errno)				\
2329 do {								\
2330 	if ((errno))						\
2331 		__ext4_std_error((sb), __func__, __LINE__, (errno));	\
2332 } while (0)
2333 
2334 #ifdef CONFIG_SMP
2335 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2336  * counters. So we need to make sure we have free clusters more
2337  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2338  */
2339 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2340 #else
2341 #define EXT4_FREECLUSTERS_WATERMARK 0
2342 #endif
2343 
2344 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2345 {
2346 	/*
2347 	 * XXX: replace with spinlock if seen contended -bzzz
2348 	 */
2349 	down_write(&EXT4_I(inode)->i_data_sem);
2350 	if (newsize > EXT4_I(inode)->i_disksize)
2351 		EXT4_I(inode)->i_disksize = newsize;
2352 	up_write(&EXT4_I(inode)->i_data_sem);
2353 	return ;
2354 }
2355 
2356 struct ext4_group_info {
2357 	unsigned long   bb_state;
2358 	struct rb_root  bb_free_root;
2359 	ext4_grpblk_t	bb_first_free;	/* first free block */
2360 	ext4_grpblk_t	bb_free;	/* total free blocks */
2361 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
2362 	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
2363 	struct          list_head bb_prealloc_list;
2364 #ifdef DOUBLE_CHECK
2365 	void            *bb_bitmap;
2366 #endif
2367 	struct rw_semaphore alloc_sem;
2368 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
2369 					 * regions, index is order.
2370 					 * bb_counters[3] = 5 means
2371 					 * 5 free 8-block regions. */
2372 };
2373 
2374 #define EXT4_GROUP_INFO_NEED_INIT_BIT		0
2375 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT		1
2376 
2377 #define EXT4_MB_GRP_NEED_INIT(grp)	\
2378 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2379 
2380 #define EXT4_MB_GRP_WAS_TRIMMED(grp)	\
2381 	(test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2382 #define EXT4_MB_GRP_SET_TRIMMED(grp)	\
2383 	(set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2384 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)	\
2385 	(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2386 
2387 #define EXT4_MAX_CONTENTION		8
2388 #define EXT4_CONTENTION_THRESHOLD	2
2389 
2390 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2391 					      ext4_group_t group)
2392 {
2393 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2394 }
2395 
2396 /*
2397  * Returns true if the filesystem is busy enough that attempts to
2398  * access the block group locks has run into contention.
2399  */
2400 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2401 {
2402 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2403 }
2404 
2405 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2406 {
2407 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2408 	if (spin_trylock(lock))
2409 		/*
2410 		 * We're able to grab the lock right away, so drop the
2411 		 * lock contention counter.
2412 		 */
2413 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2414 	else {
2415 		/*
2416 		 * The lock is busy, so bump the contention counter,
2417 		 * and then wait on the spin lock.
2418 		 */
2419 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2420 				  EXT4_MAX_CONTENTION);
2421 		spin_lock(lock);
2422 	}
2423 }
2424 
2425 static inline void ext4_unlock_group(struct super_block *sb,
2426 					ext4_group_t group)
2427 {
2428 	spin_unlock(ext4_group_lock_ptr(sb, group));
2429 }
2430 
2431 /*
2432  * Block validity checking
2433  */
2434 #define ext4_check_indirect_blockref(inode, bh)				\
2435 	ext4_check_blockref(__func__, __LINE__, inode,			\
2436 			    (__le32 *)(bh)->b_data,			\
2437 			    EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2438 
2439 #define ext4_ind_check_inode(inode)					\
2440 	ext4_check_blockref(__func__, __LINE__, inode,			\
2441 			    EXT4_I(inode)->i_data,			\
2442 			    EXT4_NDIR_BLOCKS)
2443 
2444 /*
2445  * Inodes and files operations
2446  */
2447 
2448 /* dir.c */
2449 extern const struct file_operations ext4_dir_operations;
2450 
2451 /* file.c */
2452 extern const struct inode_operations ext4_file_inode_operations;
2453 extern const struct file_operations ext4_file_operations;
2454 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2455 extern void ext4_unwritten_wait(struct inode *inode);
2456 
2457 /* inline.c */
2458 extern int ext4_has_inline_data(struct inode *inode);
2459 extern int ext4_get_inline_size(struct inode *inode);
2460 extern int ext4_get_max_inline_size(struct inode *inode);
2461 extern int ext4_find_inline_data_nolock(struct inode *inode);
2462 extern void ext4_write_inline_data(struct inode *inode,
2463 				   struct ext4_iloc *iloc,
2464 				   void *buffer, loff_t pos,
2465 				   unsigned int len);
2466 extern int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
2467 				    unsigned int len);
2468 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
2469 				 unsigned int len);
2470 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
2471 
2472 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
2473 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
2474 					 struct inode *inode,
2475 					 loff_t pos, unsigned len,
2476 					 unsigned flags,
2477 					 struct page **pagep);
2478 extern int ext4_write_inline_data_end(struct inode *inode,
2479 				      loff_t pos, unsigned len,
2480 				      unsigned copied,
2481 				      struct page *page);
2482 extern struct buffer_head *
2483 ext4_journalled_write_inline_data(struct inode *inode,
2484 				  unsigned len,
2485 				  struct page *page);
2486 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
2487 					   struct inode *inode,
2488 					   loff_t pos, unsigned len,
2489 					   unsigned flags,
2490 					   struct page **pagep,
2491 					   void **fsdata);
2492 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
2493 					 unsigned len, unsigned copied,
2494 					 struct page *page);
2495 extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
2496 				     struct inode *inode);
2497 extern int ext4_try_create_inline_dir(handle_t *handle,
2498 				      struct inode *parent,
2499 				      struct inode *inode);
2500 extern int ext4_read_inline_dir(struct file *filp,
2501 				void *dirent, filldir_t filldir,
2502 				int *has_inline_data);
2503 extern int htree_inlinedir_to_tree(struct file *dir_file,
2504 				   struct inode *dir, ext4_lblk_t block,
2505 				   struct dx_hash_info *hinfo,
2506 				   __u32 start_hash, __u32 start_minor_hash,
2507 				   int *has_inline_data);
2508 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
2509 					const struct qstr *d_name,
2510 					struct ext4_dir_entry_2 **res_dir,
2511 					int *has_inline_data);
2512 extern int ext4_delete_inline_entry(handle_t *handle,
2513 				    struct inode *dir,
2514 				    struct ext4_dir_entry_2 *de_del,
2515 				    struct buffer_head *bh,
2516 				    int *has_inline_data);
2517 extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
2518 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
2519 					struct ext4_dir_entry_2 **parent_de,
2520 					int *retval);
2521 extern int ext4_inline_data_fiemap(struct inode *inode,
2522 				   struct fiemap_extent_info *fieinfo,
2523 				   int *has_inline);
2524 extern int ext4_try_to_evict_inline_data(handle_t *handle,
2525 					 struct inode *inode,
2526 					 int needed);
2527 extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
2528 
2529 extern int ext4_convert_inline_data(struct inode *inode);
2530 
2531 /* namei.c */
2532 extern const struct inode_operations ext4_dir_inode_operations;
2533 extern const struct inode_operations ext4_special_inode_operations;
2534 extern struct dentry *ext4_get_parent(struct dentry *child);
2535 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2536 				 struct ext4_dir_entry_2 *de,
2537 				 int blocksize, int csum_size,
2538 				 unsigned int parent_ino, int dotdot_real_len);
2539 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
2540 				   unsigned int blocksize);
2541 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
2542 					 struct inode *inode,
2543 					 struct buffer_head *bh);
2544 #define S_SHIFT 12
2545 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
2546 	[S_IFREG >> S_SHIFT]	= EXT4_FT_REG_FILE,
2547 	[S_IFDIR >> S_SHIFT]	= EXT4_FT_DIR,
2548 	[S_IFCHR >> S_SHIFT]	= EXT4_FT_CHRDEV,
2549 	[S_IFBLK >> S_SHIFT]	= EXT4_FT_BLKDEV,
2550 	[S_IFIFO >> S_SHIFT]	= EXT4_FT_FIFO,
2551 	[S_IFSOCK >> S_SHIFT]	= EXT4_FT_SOCK,
2552 	[S_IFLNK >> S_SHIFT]	= EXT4_FT_SYMLINK,
2553 };
2554 
2555 static inline void ext4_set_de_type(struct super_block *sb,
2556 				struct ext4_dir_entry_2 *de,
2557 				umode_t mode) {
2558 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
2559 		de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
2560 }
2561 
2562 
2563 /* symlink.c */
2564 extern const struct inode_operations ext4_symlink_inode_operations;
2565 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2566 
2567 /* block_validity */
2568 extern void ext4_release_system_zone(struct super_block *sb);
2569 extern int ext4_setup_system_zone(struct super_block *sb);
2570 extern int __init ext4_init_system_zone(void);
2571 extern void ext4_exit_system_zone(void);
2572 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2573 				 ext4_fsblk_t start_blk,
2574 				 unsigned int count);
2575 extern int ext4_check_blockref(const char *, unsigned int,
2576 			       struct inode *, __le32 *, unsigned int);
2577 
2578 /* extents.c */
2579 struct ext4_ext_path;
2580 struct ext4_extent;
2581 
2582 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2583 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2584 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
2585 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2586 			       struct ext4_map_blocks *map, int flags);
2587 extern void ext4_ext_truncate(handle_t *, struct inode *);
2588 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2589 				 ext4_lblk_t end);
2590 extern void ext4_ext_init(struct super_block *);
2591 extern void ext4_ext_release(struct super_block *);
2592 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2593 			  loff_t len);
2594 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
2595 			  ssize_t len);
2596 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2597 			   struct ext4_map_blocks *map, int flags);
2598 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
2599 					 ext4_lblk_t lblocks);
2600 extern int ext4_extent_tree_init(handle_t *, struct inode *);
2601 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
2602 						   int num,
2603 						   struct ext4_ext_path *path);
2604 extern int ext4_can_extents_be_merged(struct inode *inode,
2605 				      struct ext4_extent *ex1,
2606 				      struct ext4_extent *ex2);
2607 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
2608 				  struct ext4_ext_path *,
2609 				  struct ext4_extent *, int);
2610 extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
2611 						  struct ext4_ext_path *);
2612 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
2613 extern int ext4_ext_check_inode(struct inode *inode);
2614 extern int ext4_find_delalloc_range(struct inode *inode,
2615 				    ext4_lblk_t lblk_start,
2616 				    ext4_lblk_t lblk_end);
2617 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
2618 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2619 			__u64 start, __u64 len);
2620 
2621 
2622 /* move_extent.c */
2623 extern void ext4_double_down_write_data_sem(struct inode *first,
2624 					    struct inode *second);
2625 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
2626 					  struct inode *donor_inode);
2627 void ext4_inode_double_lock(struct inode *inode1, struct inode *inode2);
2628 void ext4_inode_double_unlock(struct inode *inode1, struct inode *inode2);
2629 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2630 			     __u64 start_orig, __u64 start_donor,
2631 			     __u64 len, __u64 *moved_len);
2632 
2633 /* page-io.c */
2634 extern int __init ext4_init_pageio(void);
2635 extern void ext4_exit_pageio(void);
2636 extern void ext4_ioend_shutdown(struct inode *);
2637 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2638 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
2639 extern int ext4_put_io_end(ext4_io_end_t *io_end);
2640 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
2641 extern void ext4_io_submit_init(struct ext4_io_submit *io,
2642 				struct writeback_control *wbc);
2643 extern void ext4_end_io_work(struct work_struct *work);
2644 extern void ext4_io_submit(struct ext4_io_submit *io);
2645 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2646 			       struct page *page,
2647 			       int len,
2648 			       struct writeback_control *wbc);
2649 
2650 /* mmp.c */
2651 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2652 extern void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp);
2653 extern int ext4_mmp_csum_verify(struct super_block *sb,
2654 				struct mmp_struct *mmp);
2655 
2656 /*
2657  * Note that these flags will never ever appear in a buffer_head's state flag.
2658  * See EXT4_MAP_... to see where this is used.
2659  */
2660 enum ext4_state_bits {
2661 	BH_Uninit	/* blocks are allocated but uninitialized on disk */
2662 	 = BH_JBDPrivateStart,
2663 	BH_AllocFromCluster,	/* allocated blocks were part of already
2664 				 * allocated cluster. */
2665 };
2666 
2667 /*
2668  * Add new method to test whether block and inode bitmaps are properly
2669  * initialized. With uninit_bg reading the block from disk is not enough
2670  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2671  */
2672 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2673 
2674 static inline int bitmap_uptodate(struct buffer_head *bh)
2675 {
2676 	return (buffer_uptodate(bh) &&
2677 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2678 }
2679 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2680 {
2681 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2682 }
2683 
2684 /*
2685  * Disable DIO read nolock optimization, so new dioreaders will be forced
2686  * to grab i_mutex
2687  */
2688 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
2689 {
2690 	ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2691 	smp_mb();
2692 }
2693 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
2694 {
2695 	smp_mb();
2696 	ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2697 }
2698 
2699 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
2700 
2701 /* For ioend & aio unwritten conversion wait queues */
2702 #define EXT4_WQ_HASH_SZ		37
2703 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2704 					    EXT4_WQ_HASH_SZ])
2705 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2706 					     EXT4_WQ_HASH_SZ])
2707 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2708 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2709 
2710 #define EXT4_RESIZING	0
2711 extern int ext4_resize_begin(struct super_block *sb);
2712 extern void ext4_resize_end(struct super_block *sb);
2713 
2714 #endif	/* __KERNEL__ */
2715 
2716 #endif	/* _EXT4_H */
2717