xref: /openbmc/linux/fs/ext4/ext4.h (revision 84c17543)
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 
125 struct ext4_allocation_request {
126 	/* target inode for block we're allocating */
127 	struct inode *inode;
128 	/* how many blocks we want to allocate */
129 	unsigned int len;
130 	/* logical block in target inode */
131 	ext4_lblk_t logical;
132 	/* the closest logical allocated block to the left */
133 	ext4_lblk_t lleft;
134 	/* the closest logical allocated block to the right */
135 	ext4_lblk_t lright;
136 	/* phys. target (a hint) */
137 	ext4_fsblk_t goal;
138 	/* phys. block for the closest logical allocated block to the left */
139 	ext4_fsblk_t pleft;
140 	/* phys. block for the closest logical allocated block to the right */
141 	ext4_fsblk_t pright;
142 	/* flags. see above EXT4_MB_HINT_* */
143 	unsigned int flags;
144 };
145 
146 /*
147  * Logical to physical block mapping, used by ext4_map_blocks()
148  *
149  * This structure is used to pass requests into ext4_map_blocks() as
150  * well as to store the information returned by ext4_map_blocks().  It
151  * takes less room on the stack than a struct buffer_head.
152  */
153 #define EXT4_MAP_NEW		(1 << BH_New)
154 #define EXT4_MAP_MAPPED		(1 << BH_Mapped)
155 #define EXT4_MAP_UNWRITTEN	(1 << BH_Unwritten)
156 #define EXT4_MAP_BOUNDARY	(1 << BH_Boundary)
157 #define EXT4_MAP_UNINIT		(1 << BH_Uninit)
158 /* Sometimes (in the bigalloc case, from ext4_da_get_block_prep) the caller of
159  * ext4_map_blocks wants to know whether or not the underlying cluster has
160  * already been accounted for. EXT4_MAP_FROM_CLUSTER conveys to the caller that
161  * the requested mapping was from previously mapped (or delayed allocated)
162  * cluster. We use BH_AllocFromCluster only for this flag. BH_AllocFromCluster
163  * should never appear on buffer_head's state flags.
164  */
165 #define EXT4_MAP_FROM_CLUSTER	(1 << BH_AllocFromCluster)
166 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
167 				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
168 				 EXT4_MAP_UNINIT | EXT4_MAP_FROM_CLUSTER)
169 
170 struct ext4_map_blocks {
171 	ext4_fsblk_t m_pblk;
172 	ext4_lblk_t m_lblk;
173 	unsigned int m_len;
174 	unsigned int m_flags;
175 };
176 
177 /*
178  * For delayed allocation tracking
179  */
180 struct mpage_da_data {
181 	struct inode *inode;
182 	sector_t b_blocknr;		/* start block number of extent */
183 	size_t b_size;			/* size of extent */
184 	unsigned long b_state;		/* state of the extent */
185 	unsigned long first_page, next_page;	/* extent of pages */
186 	struct writeback_control *wbc;
187 	int io_done;
188 	int pages_written;
189 	int retval;
190 };
191 
192 /*
193  * Flags for ext4_io_end->flags
194  */
195 #define	EXT4_IO_END_UNWRITTEN	0x0001
196 #define EXT4_IO_END_ERROR	0x0002
197 #define EXT4_IO_END_DIRECT	0x0004
198 
199 struct ext4_io_page {
200 	struct page	*p_page;
201 	atomic_t	p_count;
202 };
203 
204 #define MAX_IO_PAGES 128
205 
206 /*
207  * For converting uninitialized extents on a work queue.
208  *
209  * 'page' is only used from the writepage() path; 'pages' is only used for
210  * buffered writes; they are used to keep page references until conversion
211  * takes place.  For AIO/DIO, neither field is filled in.
212  */
213 typedef struct ext4_io_end {
214 	struct list_head	list;		/* per-file finished IO list */
215 	struct inode		*inode;		/* file being written to */
216 	unsigned int		flag;		/* unwritten or not */
217 	loff_t			offset;		/* offset in the file */
218 	ssize_t			size;		/* size of the extent */
219 	struct kiocb		*iocb;		/* iocb struct for AIO */
220 	int			result;		/* error value for AIO */
221 	int			num_io_pages;   /* for writepages() */
222 	struct ext4_io_page	*pages[MAX_IO_PAGES]; /* for writepages() */
223 } ext4_io_end_t;
224 
225 struct ext4_io_submit {
226 	int			io_op;
227 	struct bio		*io_bio;
228 	ext4_io_end_t		*io_end;
229 	struct ext4_io_page	*io_page;
230 	sector_t		io_next_block;
231 };
232 
233 /*
234  * Special inodes numbers
235  */
236 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
237 #define EXT4_ROOT_INO		 2	/* Root inode */
238 #define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
239 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
240 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
241 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
242 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
243 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
244 
245 /* First non-reserved inode for old ext4 filesystems */
246 #define EXT4_GOOD_OLD_FIRST_INO	11
247 
248 /*
249  * Maximal count of links to a file
250  */
251 #define EXT4_LINK_MAX		65000
252 
253 /*
254  * Macro-instructions used to manage several block sizes
255  */
256 #define EXT4_MIN_BLOCK_SIZE		1024
257 #define	EXT4_MAX_BLOCK_SIZE		65536
258 #define EXT4_MIN_BLOCK_LOG_SIZE		10
259 #define EXT4_MAX_BLOCK_LOG_SIZE		16
260 #ifdef __KERNEL__
261 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
262 #else
263 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
264 #endif
265 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
266 #define EXT4_CLUSTER_SIZE(s)		(EXT4_BLOCK_SIZE(s) << \
267 					 EXT4_SB(s)->s_cluster_bits)
268 #ifdef __KERNEL__
269 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
270 # define EXT4_CLUSTER_BITS(s)		(EXT4_SB(s)->s_cluster_bits)
271 #else
272 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
273 #endif
274 #ifdef __KERNEL__
275 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
276 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
277 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
278 #else
279 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
280 				 EXT4_GOOD_OLD_INODE_SIZE : \
281 				 (s)->s_inode_size)
282 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
283 				 EXT4_GOOD_OLD_FIRST_INO : \
284 				 (s)->s_first_ino)
285 #endif
286 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
287 
288 /* Translate a block number to a cluster number */
289 #define EXT4_B2C(sbi, blk)	((blk) >> (sbi)->s_cluster_bits)
290 /* Translate a cluster number to a block number */
291 #define EXT4_C2B(sbi, cluster)	((cluster) << (sbi)->s_cluster_bits)
292 /* Translate # of blks to # of clusters */
293 #define EXT4_NUM_B2C(sbi, blks)	(((blks) + (sbi)->s_cluster_ratio - 1) >> \
294 				 (sbi)->s_cluster_bits)
295 
296 /*
297  * Structure of a blocks group descriptor
298  */
299 struct ext4_group_desc
300 {
301 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
302 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
303 	__le32	bg_inode_table_lo;	/* Inodes table block */
304 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
305 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
306 	__le16	bg_used_dirs_count_lo;	/* Directories count */
307 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
308 	__le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
309 	__le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
310 	__le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
311 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
312 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
313 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
314 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
315 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
316 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
317 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
318 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
319 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
320 	__le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
321 	__le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
322 	__le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
323 	__u32   bg_reserved;
324 };
325 
326 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END	\
327 	(offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
328 	 sizeof(__le16))
329 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END	\
330 	(offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
331 	 sizeof(__le16))
332 
333 /*
334  * Structure of a flex block group info
335  */
336 
337 struct flex_groups {
338 	atomic_t free_inodes;
339 	atomic_t free_clusters;
340 	atomic_t used_dirs;
341 };
342 
343 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
344 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
345 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
346 
347 /*
348  * Macro-instructions used to manage group descriptors
349  */
350 #define EXT4_MIN_DESC_SIZE		32
351 #define EXT4_MIN_DESC_SIZE_64BIT	64
352 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
353 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
354 #ifdef __KERNEL__
355 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
356 # define EXT4_CLUSTERS_PER_GROUP(s)	(EXT4_SB(s)->s_clusters_per_group)
357 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
358 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
359 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
360 #else
361 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
362 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
363 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
364 #endif
365 
366 /*
367  * Constants relative to the data blocks
368  */
369 #define	EXT4_NDIR_BLOCKS		12
370 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
371 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
372 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
373 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
374 
375 /*
376  * Inode flags
377  */
378 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
379 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
380 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
381 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
382 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
383 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
384 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
385 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
386 /* Reserved for compression usage... */
387 #define EXT4_DIRTY_FL			0x00000100
388 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
389 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
390 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
391 /* End compression flags --- maybe not all used */
392 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
393 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
394 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
395 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
396 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
397 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
398 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
399 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
400 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
401 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
402 #define EXT4_INLINE_DATA_FL		0x10000000 /* Inode has inline data. */
403 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
404 
405 #define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
406 #define EXT4_FL_USER_MODIFIABLE		0x004B80FF /* User modifiable flags */
407 
408 /* Flags that should be inherited by new inodes from their parent. */
409 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
410 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
411 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
412 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
413 
414 /* Flags that are appropriate for regular files (all but dir-specific ones). */
415 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
416 
417 /* Flags that are appropriate for non-directories/regular files. */
418 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
419 
420 /* Mask out flags that are inappropriate for the given type of inode. */
421 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
422 {
423 	if (S_ISDIR(mode))
424 		return flags;
425 	else if (S_ISREG(mode))
426 		return flags & EXT4_REG_FLMASK;
427 	else
428 		return flags & EXT4_OTHER_FLMASK;
429 }
430 
431 /*
432  * Inode flags used for atomic set/get
433  */
434 enum {
435 	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
436 	EXT4_INODE_UNRM		= 1,	/* Undelete */
437 	EXT4_INODE_COMPR	= 2,	/* Compress file */
438 	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
439 	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
440 	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
441 	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
442 	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
443 /* Reserved for compression usage... */
444 	EXT4_INODE_DIRTY	= 8,
445 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
446 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
447 	EXT4_INODE_ECOMPR	= 11,	/* Compression error */
448 /* End compression flags --- maybe not all used */
449 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
450 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
451 	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
452 	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
453 	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
454 	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
455 	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
456 	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
457 	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
458 	EXT4_INODE_EOFBLOCKS	= 22,	/* Blocks allocated beyond EOF */
459 	EXT4_INODE_INLINE_DATA	= 28,	/* Data in inode. */
460 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
461 };
462 
463 /*
464  * Since it's pretty easy to mix up bit numbers and hex values, we use a
465  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
466  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
467  * any extra space in the compiled kernel image, otherwise, the build will fail.
468  * It's important that these values are the same, since we are using
469  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
470  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
471  * values found in ext2, ext3 and ext4 filesystems, and of course the values
472  * defined in e2fsprogs.
473  *
474  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
475  */
476 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
477 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
478 
479 static inline void ext4_check_flag_values(void)
480 {
481 	CHECK_FLAG_VALUE(SECRM);
482 	CHECK_FLAG_VALUE(UNRM);
483 	CHECK_FLAG_VALUE(COMPR);
484 	CHECK_FLAG_VALUE(SYNC);
485 	CHECK_FLAG_VALUE(IMMUTABLE);
486 	CHECK_FLAG_VALUE(APPEND);
487 	CHECK_FLAG_VALUE(NODUMP);
488 	CHECK_FLAG_VALUE(NOATIME);
489 	CHECK_FLAG_VALUE(DIRTY);
490 	CHECK_FLAG_VALUE(COMPRBLK);
491 	CHECK_FLAG_VALUE(NOCOMPR);
492 	CHECK_FLAG_VALUE(ECOMPR);
493 	CHECK_FLAG_VALUE(INDEX);
494 	CHECK_FLAG_VALUE(IMAGIC);
495 	CHECK_FLAG_VALUE(JOURNAL_DATA);
496 	CHECK_FLAG_VALUE(NOTAIL);
497 	CHECK_FLAG_VALUE(DIRSYNC);
498 	CHECK_FLAG_VALUE(TOPDIR);
499 	CHECK_FLAG_VALUE(HUGE_FILE);
500 	CHECK_FLAG_VALUE(EXTENTS);
501 	CHECK_FLAG_VALUE(EA_INODE);
502 	CHECK_FLAG_VALUE(EOFBLOCKS);
503 	CHECK_FLAG_VALUE(INLINE_DATA);
504 	CHECK_FLAG_VALUE(RESERVED);
505 }
506 
507 /* Used to pass group descriptor data when online resize is done */
508 struct ext4_new_group_input {
509 	__u32 group;		/* Group number for this data */
510 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
511 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
512 	__u64 inode_table;	/* Absolute block number of inode table start */
513 	__u32 blocks_count;	/* Total number of blocks in this group */
514 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
515 	__u16 unused;
516 };
517 
518 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
519 struct compat_ext4_new_group_input {
520 	u32 group;
521 	compat_u64 block_bitmap;
522 	compat_u64 inode_bitmap;
523 	compat_u64 inode_table;
524 	u32 blocks_count;
525 	u16 reserved_blocks;
526 	u16 unused;
527 };
528 #endif
529 
530 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
531 struct ext4_new_group_data {
532 	__u32 group;
533 	__u64 block_bitmap;
534 	__u64 inode_bitmap;
535 	__u64 inode_table;
536 	__u32 blocks_count;
537 	__u16 reserved_blocks;
538 	__u16 unused;
539 	__u32 free_blocks_count;
540 };
541 
542 /* Indexes used to index group tables in ext4_new_group_data */
543 enum {
544 	BLOCK_BITMAP = 0,	/* block bitmap */
545 	INODE_BITMAP,		/* inode bitmap */
546 	INODE_TABLE,		/* inode tables */
547 	GROUP_TABLE_COUNT,
548 };
549 
550 /*
551  * Flags used by ext4_map_blocks()
552  */
553 	/* Allocate any needed blocks and/or convert an unitialized
554 	   extent to be an initialized ext4 */
555 #define EXT4_GET_BLOCKS_CREATE			0x0001
556 	/* Request the creation of an unitialized extent */
557 #define EXT4_GET_BLOCKS_UNINIT_EXT		0x0002
558 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\
559 						 EXT4_GET_BLOCKS_CREATE)
560 	/* Caller is from the delayed allocation writeout path,
561 	   so set the magic i_delalloc_reserve_flag after taking the
562 	   inode allocation semaphore for */
563 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
564 	/* caller is from the direct IO path, request to creation of an
565 	unitialized extents if not allocated, split the uninitialized
566 	extent if blocks has been preallocated already*/
567 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
568 #define EXT4_GET_BLOCKS_CONVERT			0x0010
569 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
570 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
571 	/* Convert extent to initialized after IO complete */
572 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
573 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
574 	/* Punch out blocks of an extent */
575 #define EXT4_GET_BLOCKS_PUNCH_OUT_EXT		0x0020
576 	/* Don't normalize allocation size (used for fallocate) */
577 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
578 	/* Request will not result in inode size update (user for fallocate) */
579 #define EXT4_GET_BLOCKS_KEEP_SIZE		0x0080
580 	/* Do not take i_data_sem locking in ext4_map_blocks */
581 #define EXT4_GET_BLOCKS_NO_LOCK			0x0100
582 
583 /*
584  * Flags used by ext4_free_blocks
585  */
586 #define EXT4_FREE_BLOCKS_METADATA	0x0001
587 #define EXT4_FREE_BLOCKS_FORGET		0x0002
588 #define EXT4_FREE_BLOCKS_VALIDATED	0x0004
589 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE	0x0008
590 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
591 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
592 
593 /*
594  * Flags used by ext4_discard_partial_page_buffers
595  */
596 #define EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED	0x0001
597 
598 /*
599  * ioctl commands
600  */
601 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
602 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
603 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
604 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
605 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
606 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
607 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
608 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
609 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
610 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
611 #define EXT4_IOC_MIGRATE		_IO('f', 9)
612  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
613  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
614 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
615 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
616 #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
617 
618 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
619 /*
620  * ioctl commands in 32 bit emulation
621  */
622 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
623 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
624 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
625 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
626 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
627 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
628 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
629 #define EXT4_IOC32_GROUP_ADD		_IOW('f', 8, struct compat_ext4_new_group_input)
630 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
631 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
632 #endif
633 
634 /* Max physical block we can address w/o extents */
635 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
636 
637 /*
638  * Structure of an inode on the disk
639  */
640 struct ext4_inode {
641 	__le16	i_mode;		/* File mode */
642 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
643 	__le32	i_size_lo;	/* Size in bytes */
644 	__le32	i_atime;	/* Access time */
645 	__le32	i_ctime;	/* Inode Change time */
646 	__le32	i_mtime;	/* Modification time */
647 	__le32	i_dtime;	/* Deletion Time */
648 	__le16	i_gid;		/* Low 16 bits of Group Id */
649 	__le16	i_links_count;	/* Links count */
650 	__le32	i_blocks_lo;	/* Blocks count */
651 	__le32	i_flags;	/* File flags */
652 	union {
653 		struct {
654 			__le32  l_i_version;
655 		} linux1;
656 		struct {
657 			__u32  h_i_translator;
658 		} hurd1;
659 		struct {
660 			__u32  m_i_reserved1;
661 		} masix1;
662 	} osd1;				/* OS dependent 1 */
663 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
664 	__le32	i_generation;	/* File version (for NFS) */
665 	__le32	i_file_acl_lo;	/* File ACL */
666 	__le32	i_size_high;
667 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
668 	union {
669 		struct {
670 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
671 			__le16	l_i_file_acl_high;
672 			__le16	l_i_uid_high;	/* these 2 fields */
673 			__le16	l_i_gid_high;	/* were reserved2[0] */
674 			__le16	l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
675 			__le16	l_i_reserved;
676 		} linux2;
677 		struct {
678 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
679 			__u16	h_i_mode_high;
680 			__u16	h_i_uid_high;
681 			__u16	h_i_gid_high;
682 			__u32	h_i_author;
683 		} hurd2;
684 		struct {
685 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
686 			__le16	m_i_file_acl_high;
687 			__u32	m_i_reserved2[2];
688 		} masix2;
689 	} osd2;				/* OS dependent 2 */
690 	__le16	i_extra_isize;
691 	__le16	i_checksum_hi;	/* crc32c(uuid+inum+inode) BE */
692 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
693 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
694 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
695 	__le32  i_crtime;       /* File Creation time */
696 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
697 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
698 };
699 
700 struct move_extent {
701 	__u32 reserved;		/* should be zero */
702 	__u32 donor_fd;		/* donor file descriptor */
703 	__u64 orig_start;	/* logical start offset in block for orig */
704 	__u64 donor_start;	/* logical start offset in block for donor */
705 	__u64 len;		/* block length to be moved */
706 	__u64 moved_len;	/* moved block length */
707 };
708 
709 #define EXT4_EPOCH_BITS 2
710 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
711 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
712 
713 /*
714  * Extended fields will fit into an inode if the filesystem was formatted
715  * with large inodes (-I 256 or larger) and there are not currently any EAs
716  * consuming all of the available space. For new inodes we always reserve
717  * enough space for the kernel's known extended fields, but for inodes
718  * created with an old kernel this might not have been the case. None of
719  * the extended inode fields is critical for correct filesystem operation.
720  * This macro checks if a certain field fits in the inode. Note that
721  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
722  */
723 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
724 	((offsetof(typeof(*ext4_inode), field) +	\
725 	  sizeof((ext4_inode)->field))			\
726 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
727 	    (einode)->i_extra_isize))			\
728 
729 static inline __le32 ext4_encode_extra_time(struct timespec *time)
730 {
731        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
732 			   (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
733                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
734 }
735 
736 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
737 {
738        if (sizeof(time->tv_sec) > 4)
739 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
740 			       << 32;
741        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
742 }
743 
744 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
745 do {									       \
746 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
747 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
748 		(raw_inode)->xtime ## _extra =				       \
749 				ext4_encode_extra_time(&(inode)->xtime);       \
750 } while (0)
751 
752 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
753 do {									       \
754 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
755 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
756 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
757 		(raw_inode)->xtime ## _extra =				       \
758 				ext4_encode_extra_time(&(einode)->xtime);      \
759 } while (0)
760 
761 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
762 do {									       \
763 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
764 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
765 		ext4_decode_extra_time(&(inode)->xtime,			       \
766 				       raw_inode->xtime ## _extra);	       \
767 	else								       \
768 		(inode)->xtime.tv_nsec = 0;				       \
769 } while (0)
770 
771 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
772 do {									       \
773 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
774 		(einode)->xtime.tv_sec = 				       \
775 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
776 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
777 		ext4_decode_extra_time(&(einode)->xtime,		       \
778 				       raw_inode->xtime ## _extra);	       \
779 	else								       \
780 		(einode)->xtime.tv_nsec = 0;				       \
781 } while (0)
782 
783 #define i_disk_version osd1.linux1.l_i_version
784 
785 #if defined(__KERNEL__) || defined(__linux__)
786 #define i_reserved1	osd1.linux1.l_i_reserved1
787 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
788 #define i_blocks_high	osd2.linux2.l_i_blocks_high
789 #define i_uid_low	i_uid
790 #define i_gid_low	i_gid
791 #define i_uid_high	osd2.linux2.l_i_uid_high
792 #define i_gid_high	osd2.linux2.l_i_gid_high
793 #define i_checksum_lo	osd2.linux2.l_i_checksum_lo
794 
795 #elif defined(__GNU__)
796 
797 #define i_translator	osd1.hurd1.h_i_translator
798 #define i_uid_high	osd2.hurd2.h_i_uid_high
799 #define i_gid_high	osd2.hurd2.h_i_gid_high
800 #define i_author	osd2.hurd2.h_i_author
801 
802 #elif defined(__masix__)
803 
804 #define i_reserved1	osd1.masix1.m_i_reserved1
805 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
806 #define i_reserved2	osd2.masix2.m_i_reserved2
807 
808 #endif /* defined(__KERNEL__) || defined(__linux__) */
809 
810 /*
811  * storage for cached extent
812  * If ec_len == 0, then the cache is invalid.
813  * If ec_start == 0, then the cache represents a gap (null mapping)
814  */
815 struct ext4_ext_cache {
816 	ext4_fsblk_t	ec_start;
817 	ext4_lblk_t	ec_block;
818 	__u32		ec_len; /* must be 32bit to return holes */
819 };
820 
821 #include "extents_status.h"
822 
823 /*
824  * fourth extended file system inode data in memory
825  */
826 struct ext4_inode_info {
827 	__le32	i_data[15];	/* unconverted */
828 	__u32	i_dtime;
829 	ext4_fsblk_t	i_file_acl;
830 
831 	/*
832 	 * i_block_group is the number of the block group which contains
833 	 * this file's inode.  Constant across the lifetime of the inode,
834 	 * it is ued for making block allocation decisions - we try to
835 	 * place a file's data blocks near its inode block, and new inodes
836 	 * near to their parent directory's inode.
837 	 */
838 	ext4_group_t	i_block_group;
839 	ext4_lblk_t	i_dir_start_lookup;
840 #if (BITS_PER_LONG < 64)
841 	unsigned long	i_state_flags;		/* Dynamic state flags */
842 #endif
843 	unsigned long	i_flags;
844 
845 	/*
846 	 * Extended attributes can be read independently of the main file
847 	 * data. Taking i_mutex even when reading would cause contention
848 	 * between readers of EAs and writers of regular file data, so
849 	 * instead we synchronize on xattr_sem when reading or changing
850 	 * EAs.
851 	 */
852 	struct rw_semaphore xattr_sem;
853 
854 	struct list_head i_orphan;	/* unlinked but open inodes */
855 
856 	/*
857 	 * i_disksize keeps track of what the inode size is ON DISK, not
858 	 * in memory.  During truncate, i_size is set to the new size by
859 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
860 	 * set i_disksize to 0 until the truncate is actually under way.
861 	 *
862 	 * The intent is that i_disksize always represents the blocks which
863 	 * are used by this file.  This allows recovery to restart truncate
864 	 * on orphans if we crash during truncate.  We actually write i_disksize
865 	 * into the on-disk inode when writing inodes out, instead of i_size.
866 	 *
867 	 * The only time when i_disksize and i_size may be different is when
868 	 * a truncate is in progress.  The only things which change i_disksize
869 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
870 	 */
871 	loff_t	i_disksize;
872 
873 	/*
874 	 * i_data_sem is for serialising ext4_truncate() against
875 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
876 	 * data tree are chopped off during truncate. We can't do that in
877 	 * ext4 because whenever we perform intermediate commits during
878 	 * truncate, the inode and all the metadata blocks *must* be in a
879 	 * consistent state which allows truncation of the orphans to restart
880 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
881 	 * by other means, so we have i_data_sem.
882 	 */
883 	struct rw_semaphore i_data_sem;
884 	struct inode vfs_inode;
885 	struct jbd2_inode *jinode;
886 
887 	struct ext4_ext_cache i_cached_extent;
888 	/*
889 	 * File creation time. Its function is same as that of
890 	 * struct timespec i_{a,c,m}time in the generic inode.
891 	 */
892 	struct timespec i_crtime;
893 
894 	/* mballoc */
895 	struct list_head i_prealloc_list;
896 	spinlock_t i_prealloc_lock;
897 
898 	/* extents status tree */
899 	struct ext4_es_tree i_es_tree;
900 	rwlock_t i_es_lock;
901 
902 	/* ialloc */
903 	ext4_group_t	i_last_alloc_group;
904 
905 	/* allocation reservation info for delalloc */
906 	/* In case of bigalloc, these refer to clusters rather than blocks */
907 	unsigned int i_reserved_data_blocks;
908 	unsigned int i_reserved_meta_blocks;
909 	unsigned int i_allocated_meta_blocks;
910 	ext4_lblk_t i_da_metadata_calc_last_lblock;
911 	int i_da_metadata_calc_len;
912 
913 	/* on-disk additional length */
914 	__u16 i_extra_isize;
915 
916 	/* Indicate the inline data space. */
917 	u16 i_inline_off;
918 	u16 i_inline_size;
919 
920 #ifdef CONFIG_QUOTA
921 	/* quota space reservation, managed internally by quota code */
922 	qsize_t i_reserved_quota;
923 #endif
924 
925 	/* completed IOs that might need unwritten extents handling */
926 	struct list_head i_completed_io_list;
927 	spinlock_t i_completed_io_lock;
928 	atomic_t i_ioend_count;	/* Number of outstanding io_end structs */
929 	atomic_t i_unwritten; /* Nr. of inflight conversions pending */
930 	struct work_struct i_unwritten_work;	/* deferred extent conversion */
931 
932 	spinlock_t i_block_reservation_lock;
933 
934 	/*
935 	 * Transactions that contain inode's metadata needed to complete
936 	 * fsync and fdatasync, respectively.
937 	 */
938 	tid_t i_sync_tid;
939 	tid_t i_datasync_tid;
940 
941 	/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
942 	__u32 i_csum_seed;
943 };
944 
945 /*
946  * File system states
947  */
948 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
949 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
950 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
951 
952 /*
953  * Misc. filesystem flags
954  */
955 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
956 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
957 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
958 
959 /*
960  * Mount flags
961  */
962 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
963 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
964 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
965 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
966 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
967 #define EXT4_MOUNT_ERRORS_MASK		0x00070
968 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
969 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
970 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
971 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
972 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
973 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
974 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
975 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
976 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
977 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
978 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
979 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
980 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
981 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
982 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
983 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
984 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
985 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
986 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
987 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
988 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
989 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
990 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
991 
992 #define EXT4_MOUNT2_EXPLICIT_DELALLOC	0x00000001 /* User explicitly
993 						      specified delalloc */
994 
995 #define clear_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt &= \
996 						~EXT4_MOUNT_##opt
997 #define set_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt |= \
998 						EXT4_MOUNT_##opt
999 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
1000 					 EXT4_MOUNT_##opt)
1001 
1002 #define clear_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 &= \
1003 						~EXT4_MOUNT2_##opt
1004 #define set_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 |= \
1005 						EXT4_MOUNT2_##opt
1006 #define test_opt2(sb, opt)		(EXT4_SB(sb)->s_mount_opt2 & \
1007 					 EXT4_MOUNT2_##opt)
1008 
1009 #define ext4_test_and_set_bit		__test_and_set_bit_le
1010 #define ext4_set_bit			__set_bit_le
1011 #define ext4_set_bit_atomic		ext2_set_bit_atomic
1012 #define ext4_test_and_clear_bit		__test_and_clear_bit_le
1013 #define ext4_clear_bit			__clear_bit_le
1014 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
1015 #define ext4_test_bit			test_bit_le
1016 #define ext4_find_next_zero_bit		find_next_zero_bit_le
1017 #define ext4_find_next_bit		find_next_bit_le
1018 
1019 extern void ext4_set_bits(void *bm, int cur, int len);
1020 
1021 /*
1022  * Maximal mount counts between two filesystem checks
1023  */
1024 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
1025 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
1026 
1027 /*
1028  * Behaviour when detecting errors
1029  */
1030 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
1031 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
1032 #define EXT4_ERRORS_PANIC		3	/* Panic */
1033 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
1034 
1035 /* Metadata checksum algorithm codes */
1036 #define EXT4_CRC32C_CHKSUM		1
1037 
1038 /*
1039  * Structure of the super block
1040  */
1041 struct ext4_super_block {
1042 /*00*/	__le32	s_inodes_count;		/* Inodes count */
1043 	__le32	s_blocks_count_lo;	/* Blocks count */
1044 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
1045 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
1046 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
1047 	__le32	s_first_data_block;	/* First Data Block */
1048 	__le32	s_log_block_size;	/* Block size */
1049 	__le32	s_log_cluster_size;	/* Allocation cluster size */
1050 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
1051 	__le32	s_clusters_per_group;	/* # Clusters per group */
1052 	__le32	s_inodes_per_group;	/* # Inodes per group */
1053 	__le32	s_mtime;		/* Mount time */
1054 /*30*/	__le32	s_wtime;		/* Write time */
1055 	__le16	s_mnt_count;		/* Mount count */
1056 	__le16	s_max_mnt_count;	/* Maximal mount count */
1057 	__le16	s_magic;		/* Magic signature */
1058 	__le16	s_state;		/* File system state */
1059 	__le16	s_errors;		/* Behaviour when detecting errors */
1060 	__le16	s_minor_rev_level;	/* minor revision level */
1061 /*40*/	__le32	s_lastcheck;		/* time of last check */
1062 	__le32	s_checkinterval;	/* max. time between checks */
1063 	__le32	s_creator_os;		/* OS */
1064 	__le32	s_rev_level;		/* Revision level */
1065 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
1066 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
1067 	/*
1068 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
1069 	 *
1070 	 * Note: the difference between the compatible feature set and
1071 	 * the incompatible feature set is that if there is a bit set
1072 	 * in the incompatible feature set that the kernel doesn't
1073 	 * know about, it should refuse to mount the filesystem.
1074 	 *
1075 	 * e2fsck's requirements are more strict; if it doesn't know
1076 	 * about a feature in either the compatible or incompatible
1077 	 * feature set, it must abort and not try to meddle with
1078 	 * things it doesn't understand...
1079 	 */
1080 	__le32	s_first_ino;		/* First non-reserved inode */
1081 	__le16  s_inode_size;		/* size of inode structure */
1082 	__le16	s_block_group_nr;	/* block group # of this superblock */
1083 	__le32	s_feature_compat;	/* compatible feature set */
1084 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
1085 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
1086 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
1087 /*78*/	char	s_volume_name[16];	/* volume name */
1088 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
1089 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
1090 	/*
1091 	 * Performance hints.  Directory preallocation should only
1092 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1093 	 */
1094 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
1095 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
1096 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
1097 	/*
1098 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1099 	 */
1100 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
1101 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
1102 	__le32	s_journal_dev;		/* device number of journal file */
1103 	__le32	s_last_orphan;		/* start of list of inodes to delete */
1104 	__le32	s_hash_seed[4];		/* HTREE hash seed */
1105 	__u8	s_def_hash_version;	/* Default hash version to use */
1106 	__u8	s_jnl_backup_type;
1107 	__le16  s_desc_size;		/* size of group descriptor */
1108 /*100*/	__le32	s_default_mount_opts;
1109 	__le32	s_first_meta_bg;	/* First metablock block group */
1110 	__le32	s_mkfs_time;		/* When the filesystem was created */
1111 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
1112 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1113 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
1114 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
1115 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
1116 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
1117 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
1118 	__le32	s_flags;		/* Miscellaneous flags */
1119 	__le16  s_raid_stride;		/* RAID stride */
1120 	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1121 	__le64  s_mmp_block;            /* Block for multi-mount protection */
1122 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1123 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
1124 	__u8	s_checksum_type;	/* metadata checksum algorithm used */
1125 	__le16  s_reserved_pad;
1126 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1127 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
1128 	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
1129 	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
1130 					      snapshot's future use */
1131 	__le32	s_snapshot_list;	/* inode number of the head of the
1132 					   on-disk snapshot list */
1133 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1134 	__le32	s_error_count;		/* number of fs errors */
1135 	__le32	s_first_error_time;	/* first time an error happened */
1136 	__le32	s_first_error_ino;	/* inode involved in first error */
1137 	__le64	s_first_error_block;	/* block involved of first error */
1138 	__u8	s_first_error_func[32];	/* function where the error happened */
1139 	__le32	s_first_error_line;	/* line number where error happened */
1140 	__le32	s_last_error_time;	/* most recent time of an error */
1141 	__le32	s_last_error_ino;	/* inode involved in last error */
1142 	__le32	s_last_error_line;	/* line number where error happened */
1143 	__le64	s_last_error_block;	/* block involved of last error */
1144 	__u8	s_last_error_func[32];	/* function where the error happened */
1145 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1146 	__u8	s_mount_opts[64];
1147 	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
1148 	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
1149 	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
1150 	__le32	s_reserved[108];	/* Padding to the end of the block */
1151 	__le32	s_checksum;		/* crc32c(superblock) */
1152 };
1153 
1154 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1155 
1156 #ifdef __KERNEL__
1157 
1158 /*
1159  * run-time mount flags
1160  */
1161 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
1162 #define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
1163 
1164 /*
1165  * fourth extended-fs super-block data in memory
1166  */
1167 struct ext4_sb_info {
1168 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
1169 	unsigned long s_inodes_per_block;/* Number of inodes per block */
1170 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
1171 	unsigned long s_clusters_per_group; /* Number of clusters in a group */
1172 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
1173 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
1174 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
1175 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
1176 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1177 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1178 	unsigned long s_overhead;  /* # of fs overhead clusters */
1179 	unsigned int s_cluster_ratio;	/* Number of blocks per cluster */
1180 	unsigned int s_cluster_bits;	/* log2 of s_cluster_ratio */
1181 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
1182 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
1183 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
1184 	struct buffer_head **s_group_desc;
1185 	unsigned int s_mount_opt;
1186 	unsigned int s_mount_opt2;
1187 	unsigned int s_mount_flags;
1188 	unsigned int s_def_mount_opt;
1189 	ext4_fsblk_t s_sb_block;
1190 	kuid_t s_resuid;
1191 	kgid_t s_resgid;
1192 	unsigned short s_mount_state;
1193 	unsigned short s_pad;
1194 	int s_addr_per_block_bits;
1195 	int s_desc_per_block_bits;
1196 	int s_inode_size;
1197 	int s_first_ino;
1198 	unsigned int s_inode_readahead_blks;
1199 	unsigned int s_inode_goal;
1200 	spinlock_t s_next_gen_lock;
1201 	u32 s_next_generation;
1202 	u32 s_hash_seed[4];
1203 	int s_def_hash_version;
1204 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
1205 	struct percpu_counter s_freeclusters_counter;
1206 	struct percpu_counter s_freeinodes_counter;
1207 	struct percpu_counter s_dirs_counter;
1208 	struct percpu_counter s_dirtyclusters_counter;
1209 	struct blockgroup_lock *s_blockgroup_lock;
1210 	struct proc_dir_entry *s_proc;
1211 	struct kobject s_kobj;
1212 	struct completion s_kobj_unregister;
1213 	struct super_block *s_sb;
1214 
1215 	/* Journaling */
1216 	struct journal_s *s_journal;
1217 	struct list_head s_orphan;
1218 	struct mutex s_orphan_lock;
1219 	unsigned long s_resize_flags;		/* Flags indicating if there
1220 						   is a resizer */
1221 	unsigned long s_commit_interval;
1222 	u32 s_max_batch_time;
1223 	u32 s_min_batch_time;
1224 	struct block_device *journal_bdev;
1225 #ifdef CONFIG_QUOTA
1226 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
1227 	int s_jquota_fmt;			/* Format of quota to use */
1228 #endif
1229 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1230 	struct rb_root system_blks;
1231 
1232 #ifdef EXTENTS_STATS
1233 	/* ext4 extents stats */
1234 	unsigned long s_ext_min;
1235 	unsigned long s_ext_max;
1236 	unsigned long s_depth_max;
1237 	spinlock_t s_ext_stats_lock;
1238 	unsigned long s_ext_blocks;
1239 	unsigned long s_ext_extents;
1240 #endif
1241 
1242 	/* for buddy allocator */
1243 	struct ext4_group_info ***s_group_info;
1244 	struct inode *s_buddy_cache;
1245 	spinlock_t s_md_lock;
1246 	unsigned short *s_mb_offsets;
1247 	unsigned int *s_mb_maxs;
1248 	unsigned int s_group_info_size;
1249 
1250 	/* tunables */
1251 	unsigned long s_stripe;
1252 	unsigned int s_mb_stream_request;
1253 	unsigned int s_mb_max_to_scan;
1254 	unsigned int s_mb_min_to_scan;
1255 	unsigned int s_mb_stats;
1256 	unsigned int s_mb_order2_reqs;
1257 	unsigned int s_mb_group_prealloc;
1258 	unsigned int s_max_writeback_mb_bump;
1259 	unsigned int s_max_dir_size_kb;
1260 	/* where last allocation was done - for stream allocation */
1261 	unsigned long s_mb_last_group;
1262 	unsigned long s_mb_last_start;
1263 
1264 	/* stats for buddy allocator */
1265 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1266 	atomic_t s_bal_success;	/* we found long enough chunks */
1267 	atomic_t s_bal_allocated;	/* in blocks */
1268 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1269 	atomic_t s_bal_goals;	/* goal hits */
1270 	atomic_t s_bal_breaks;	/* too long searches */
1271 	atomic_t s_bal_2orders;	/* 2^order hits */
1272 	spinlock_t s_bal_lock;
1273 	unsigned long s_mb_buddies_generated;
1274 	unsigned long long s_mb_generation_time;
1275 	atomic_t s_mb_lost_chunks;
1276 	atomic_t s_mb_preallocated;
1277 	atomic_t s_mb_discarded;
1278 	atomic_t s_lock_busy;
1279 
1280 	/* locality groups */
1281 	struct ext4_locality_group __percpu *s_locality_groups;
1282 
1283 	/* for write statistics */
1284 	unsigned long s_sectors_written_start;
1285 	u64 s_kbytes_written;
1286 
1287 	/* the size of zero-out chunk */
1288 	unsigned int s_extent_max_zeroout_kb;
1289 
1290 	unsigned int s_log_groups_per_flex;
1291 	struct flex_groups *s_flex_groups;
1292 	ext4_group_t s_flex_groups_allocated;
1293 
1294 	/* workqueue for dio unwritten */
1295 	struct workqueue_struct *dio_unwritten_wq;
1296 
1297 	/* timer for periodic error stats printing */
1298 	struct timer_list s_err_report;
1299 
1300 	/* Lazy inode table initialization info */
1301 	struct ext4_li_request *s_li_request;
1302 	/* Wait multiplier for lazy initialization thread */
1303 	unsigned int s_li_wait_mult;
1304 
1305 	/* Kernel thread for multiple mount protection */
1306 	struct task_struct *s_mmp_tsk;
1307 
1308 	/* record the last minlen when FITRIM is called. */
1309 	atomic_t s_last_trim_minblks;
1310 
1311 	/* Reference to checksum algorithm driver via cryptoapi */
1312 	struct crypto_shash *s_chksum_driver;
1313 
1314 	/* Precomputed FS UUID checksum for seeding other checksums */
1315 	__u32 s_csum_seed;
1316 };
1317 
1318 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1319 {
1320 	return sb->s_fs_info;
1321 }
1322 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1323 {
1324 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1325 }
1326 
1327 static inline struct timespec ext4_current_time(struct inode *inode)
1328 {
1329 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1330 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1331 }
1332 
1333 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1334 {
1335 	return ino == EXT4_ROOT_INO ||
1336 		ino == EXT4_USR_QUOTA_INO ||
1337 		ino == EXT4_GRP_QUOTA_INO ||
1338 		ino == EXT4_JOURNAL_INO ||
1339 		ino == EXT4_RESIZE_INO ||
1340 		(ino >= EXT4_FIRST_INO(sb) &&
1341 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1342 }
1343 
1344 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1345 					      struct ext4_io_end *io_end)
1346 {
1347 	if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1348 		io_end->flag |= EXT4_IO_END_UNWRITTEN;
1349 		atomic_inc(&EXT4_I(inode)->i_unwritten);
1350 	}
1351 }
1352 
1353 static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode)
1354 {
1355 	return inode->i_private;
1356 }
1357 
1358 static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io)
1359 {
1360 	inode->i_private = io;
1361 }
1362 
1363 /*
1364  * Inode dynamic state flags
1365  */
1366 enum {
1367 	EXT4_STATE_JDATA,		/* journaled data exists */
1368 	EXT4_STATE_NEW,			/* inode is newly created */
1369 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1370 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1371 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1372 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1373 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1374 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1375 	EXT4_STATE_DELALLOC_RESERVED,	/* blks already reserved for delalloc */
1376 	EXT4_STATE_DIOREAD_LOCK,	/* Disable support for dio read
1377 					   nolocking */
1378 	EXT4_STATE_MAY_INLINE_DATA,	/* may have in-inode data */
1379 };
1380 
1381 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
1382 static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
1383 {									\
1384 	return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);	\
1385 }									\
1386 static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
1387 {									\
1388 	set_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1389 }									\
1390 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1391 {									\
1392 	clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1393 }
1394 
1395 EXT4_INODE_BIT_FNS(flag, flags, 0)
1396 #if (BITS_PER_LONG < 64)
1397 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1398 
1399 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1400 {
1401 	(ei)->i_state_flags = 0;
1402 }
1403 #else
1404 EXT4_INODE_BIT_FNS(state, flags, 32)
1405 
1406 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1407 {
1408 	/* We depend on the fact that callers will set i_flags */
1409 }
1410 #endif
1411 #else
1412 /* Assume that user mode programs are passing in an ext4fs superblock, not
1413  * a kernel struct super_block.  This will allow us to call the feature-test
1414  * macros from user land. */
1415 #define EXT4_SB(sb)	(sb)
1416 #endif
1417 
1418 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1419 
1420 /*
1421  * Codes for operating systems
1422  */
1423 #define EXT4_OS_LINUX		0
1424 #define EXT4_OS_HURD		1
1425 #define EXT4_OS_MASIX		2
1426 #define EXT4_OS_FREEBSD		3
1427 #define EXT4_OS_LITES		4
1428 
1429 /*
1430  * Revision levels
1431  */
1432 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1433 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1434 
1435 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1436 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1437 
1438 #define EXT4_GOOD_OLD_INODE_SIZE 128
1439 
1440 /*
1441  * Feature set definitions
1442  */
1443 
1444 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1445 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1446 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1447 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1448 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1449 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1450 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1451 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1452 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1453 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1454 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1455 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1456 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1457 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1458 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1459 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1460 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1461 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1462 
1463 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1464 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1465 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1466 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1467 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1468 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1469 
1470 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1471 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1472 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1473 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1474 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1475 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1476 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1477 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
1478 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
1479 /*
1480  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1481  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1482  * all other data structures' checksums.  However, the METADATA_CSUM and
1483  * GDT_CSUM bits are mutually exclusive.
1484  */
1485 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
1486 
1487 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1488 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1489 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1490 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1491 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1492 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1493 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1494 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1495 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1496 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1497 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1498 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM	0x2000 /* use crc32c for bg */
1499 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
1500 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA	0x8000 /* data in inode */
1501 
1502 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1503 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1504 					 EXT4_FEATURE_INCOMPAT_META_BG)
1505 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1506 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1507 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1508 
1509 #define EXT3_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1510 #define EXT3_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1511 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1512 					 EXT4_FEATURE_INCOMPAT_META_BG)
1513 #define EXT3_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1514 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1515 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1516 
1517 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1518 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1519 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1520 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1521 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1522 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1523 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1524 					 EXT4_FEATURE_INCOMPAT_MMP |	\
1525 					 EXT4_FEATURE_INCOMPAT_INLINE_DATA)
1526 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1527 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1528 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1529 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1530 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1531 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1532 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1533 					 EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1534 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1535 					 EXT4_FEATURE_RO_COMPAT_QUOTA)
1536 
1537 /*
1538  * Default values for user and/or group using reserved blocks
1539  */
1540 #define	EXT4_DEF_RESUID		0
1541 #define	EXT4_DEF_RESGID		0
1542 
1543 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1544 
1545 /*
1546  * Default mount options
1547  */
1548 #define EXT4_DEFM_DEBUG		0x0001
1549 #define EXT4_DEFM_BSDGROUPS	0x0002
1550 #define EXT4_DEFM_XATTR_USER	0x0004
1551 #define EXT4_DEFM_ACL		0x0008
1552 #define EXT4_DEFM_UID16		0x0010
1553 #define EXT4_DEFM_JMODE		0x0060
1554 #define EXT4_DEFM_JMODE_DATA	0x0020
1555 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1556 #define EXT4_DEFM_JMODE_WBACK	0x0060
1557 #define EXT4_DEFM_NOBARRIER	0x0100
1558 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1559 #define EXT4_DEFM_DISCARD	0x0400
1560 #define EXT4_DEFM_NODELALLOC	0x0800
1561 
1562 /*
1563  * Default journal batch times
1564  */
1565 #define EXT4_DEF_MIN_BATCH_TIME	0
1566 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1567 
1568 /*
1569  * Minimum number of groups in a flexgroup before we separate out
1570  * directories into the first block group of a flexgroup
1571  */
1572 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1573 
1574 /*
1575  * Structure of a directory entry
1576  */
1577 #define EXT4_NAME_LEN 255
1578 
1579 struct ext4_dir_entry {
1580 	__le32	inode;			/* Inode number */
1581 	__le16	rec_len;		/* Directory entry length */
1582 	__le16	name_len;		/* Name length */
1583 	char	name[EXT4_NAME_LEN];	/* File name */
1584 };
1585 
1586 /*
1587  * The new version of the directory entry.  Since EXT4 structures are
1588  * stored in intel byte order, and the name_len field could never be
1589  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1590  * file_type field.
1591  */
1592 struct ext4_dir_entry_2 {
1593 	__le32	inode;			/* Inode number */
1594 	__le16	rec_len;		/* Directory entry length */
1595 	__u8	name_len;		/* Name length */
1596 	__u8	file_type;
1597 	char	name[EXT4_NAME_LEN];	/* File name */
1598 };
1599 
1600 /*
1601  * This is a bogus directory entry at the end of each leaf block that
1602  * records checksums.
1603  */
1604 struct ext4_dir_entry_tail {
1605 	__le32	det_reserved_zero1;	/* Pretend to be unused */
1606 	__le16	det_rec_len;		/* 12 */
1607 	__u8	det_reserved_zero2;	/* Zero name length */
1608 	__u8	det_reserved_ft;	/* 0xDE, fake file type */
1609 	__le32	det_checksum;		/* crc32c(uuid+inum+dirblock) */
1610 };
1611 
1612 #define EXT4_DIRENT_TAIL(block, blocksize) \
1613 	((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1614 					((blocksize) - \
1615 					 sizeof(struct ext4_dir_entry_tail))))
1616 
1617 /*
1618  * Ext4 directory file types.  Only the low 3 bits are used.  The
1619  * other bits are reserved for now.
1620  */
1621 #define EXT4_FT_UNKNOWN		0
1622 #define EXT4_FT_REG_FILE	1
1623 #define EXT4_FT_DIR		2
1624 #define EXT4_FT_CHRDEV		3
1625 #define EXT4_FT_BLKDEV		4
1626 #define EXT4_FT_FIFO		5
1627 #define EXT4_FT_SOCK		6
1628 #define EXT4_FT_SYMLINK		7
1629 
1630 #define EXT4_FT_MAX		8
1631 
1632 #define EXT4_FT_DIR_CSUM	0xDE
1633 
1634 /*
1635  * EXT4_DIR_PAD defines the directory entries boundaries
1636  *
1637  * NOTE: It must be a multiple of 4
1638  */
1639 #define EXT4_DIR_PAD			4
1640 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1641 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1642 					 ~EXT4_DIR_ROUND)
1643 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1644 
1645 /*
1646  * If we ever get support for fs block sizes > page_size, we'll need
1647  * to remove the #if statements in the next two functions...
1648  */
1649 static inline unsigned int
1650 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1651 {
1652 	unsigned len = le16_to_cpu(dlen);
1653 
1654 #if (PAGE_CACHE_SIZE >= 65536)
1655 	if (len == EXT4_MAX_REC_LEN || len == 0)
1656 		return blocksize;
1657 	return (len & 65532) | ((len & 3) << 16);
1658 #else
1659 	return len;
1660 #endif
1661 }
1662 
1663 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1664 {
1665 	if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1666 		BUG();
1667 #if (PAGE_CACHE_SIZE >= 65536)
1668 	if (len < 65536)
1669 		return cpu_to_le16(len);
1670 	if (len == blocksize) {
1671 		if (blocksize == 65536)
1672 			return cpu_to_le16(EXT4_MAX_REC_LEN);
1673 		else
1674 			return cpu_to_le16(0);
1675 	}
1676 	return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1677 #else
1678 	return cpu_to_le16(len);
1679 #endif
1680 }
1681 
1682 /*
1683  * Hash Tree Directory indexing
1684  * (c) Daniel Phillips, 2001
1685  */
1686 
1687 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1688 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1689 		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1690 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1691 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1692 
1693 /* Legal values for the dx_root hash_version field: */
1694 
1695 #define DX_HASH_LEGACY		0
1696 #define DX_HASH_HALF_MD4	1
1697 #define DX_HASH_TEA		2
1698 #define DX_HASH_LEGACY_UNSIGNED	3
1699 #define DX_HASH_HALF_MD4_UNSIGNED	4
1700 #define DX_HASH_TEA_UNSIGNED		5
1701 
1702 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1703 			      const void *address, unsigned int length)
1704 {
1705 	struct {
1706 		struct shash_desc shash;
1707 		char ctx[4];
1708 	} desc;
1709 	int err;
1710 
1711 	BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
1712 
1713 	desc.shash.tfm = sbi->s_chksum_driver;
1714 	desc.shash.flags = 0;
1715 	*(u32 *)desc.ctx = crc;
1716 
1717 	err = crypto_shash_update(&desc.shash, address, length);
1718 	BUG_ON(err);
1719 
1720 	return *(u32 *)desc.ctx;
1721 }
1722 
1723 #ifdef __KERNEL__
1724 
1725 /* hash info structure used by the directory hash */
1726 struct dx_hash_info
1727 {
1728 	u32		hash;
1729 	u32		minor_hash;
1730 	int		hash_version;
1731 	u32		*seed;
1732 };
1733 
1734 
1735 /* 32 and 64 bit signed EOF for dx directories */
1736 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
1737 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
1738 
1739 
1740 /*
1741  * Control parameters used by ext4_htree_next_block
1742  */
1743 #define HASH_NB_ALWAYS		1
1744 
1745 
1746 /*
1747  * Describe an inode's exact location on disk and in memory
1748  */
1749 struct ext4_iloc
1750 {
1751 	struct buffer_head *bh;
1752 	unsigned long offset;
1753 	ext4_group_t block_group;
1754 };
1755 
1756 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1757 {
1758 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1759 }
1760 
1761 /*
1762  * This structure is stuffed into the struct file's private_data field
1763  * for directories.  It is where we put information so that we can do
1764  * readdir operations in hash tree order.
1765  */
1766 struct dir_private_info {
1767 	struct rb_root	root;
1768 	struct rb_node	*curr_node;
1769 	struct fname	*extra_fname;
1770 	loff_t		last_pos;
1771 	__u32		curr_hash;
1772 	__u32		curr_minor_hash;
1773 	__u32		next_hash;
1774 };
1775 
1776 /* calculate the first block number of the group */
1777 static inline ext4_fsblk_t
1778 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1779 {
1780 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1781 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1782 }
1783 
1784 /*
1785  * Special error return code only used by dx_probe() and its callers.
1786  */
1787 #define ERR_BAD_DX_DIR	-75000
1788 
1789 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1790 			ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1791 
1792 /*
1793  * Timeout and state flag for lazy initialization inode thread.
1794  */
1795 #define EXT4_DEF_LI_WAIT_MULT			10
1796 #define EXT4_DEF_LI_MAX_START_DELAY		5
1797 #define EXT4_LAZYINIT_QUIT			0x0001
1798 #define EXT4_LAZYINIT_RUNNING			0x0002
1799 
1800 /*
1801  * Lazy inode table initialization info
1802  */
1803 struct ext4_lazy_init {
1804 	unsigned long		li_state;
1805 	struct list_head	li_request_list;
1806 	struct mutex		li_list_mtx;
1807 };
1808 
1809 struct ext4_li_request {
1810 	struct super_block	*lr_super;
1811 	struct ext4_sb_info	*lr_sbi;
1812 	ext4_group_t		lr_next_group;
1813 	struct list_head	lr_request;
1814 	unsigned long		lr_next_sched;
1815 	unsigned long		lr_timeout;
1816 };
1817 
1818 struct ext4_features {
1819 	struct kobject f_kobj;
1820 	struct completion f_kobj_unregister;
1821 };
1822 
1823 /*
1824  * This structure will be used for multiple mount protection. It will be
1825  * written into the block number saved in the s_mmp_block field in the
1826  * superblock. Programs that check MMP should assume that if
1827  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1828  * to use the filesystem, regardless of how old the timestamp is.
1829  */
1830 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1831 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1832 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1833 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1834 
1835 struct mmp_struct {
1836 	__le32	mmp_magic;		/* Magic number for MMP */
1837 	__le32	mmp_seq;		/* Sequence no. updated periodically */
1838 
1839 	/*
1840 	 * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1841 	 * purposes and do not affect the correctness of the algorithm
1842 	 */
1843 	__le64	mmp_time;		/* Time last updated */
1844 	char	mmp_nodename[64];	/* Node which last updated MMP block */
1845 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
1846 
1847 	/*
1848 	 * mmp_check_interval is used to verify if the MMP block has been
1849 	 * updated on the block device. The value is updated based on the
1850 	 * maximum time to write the MMP block during an update cycle.
1851 	 */
1852 	__le16	mmp_check_interval;
1853 
1854 	__le16	mmp_pad1;
1855 	__le32	mmp_pad2[226];
1856 	__le32	mmp_checksum;		/* crc32c(uuid+mmp_block) */
1857 };
1858 
1859 /* arguments passed to the mmp thread */
1860 struct mmpd_data {
1861 	struct buffer_head *bh; /* bh from initial read_mmp_block() */
1862 	struct super_block *sb;  /* super block of the fs */
1863 };
1864 
1865 /*
1866  * Check interval multiplier
1867  * The MMP block is written every update interval and initially checked every
1868  * update interval x the multiplier (the value is then adapted based on the
1869  * write latency). The reason is that writes can be delayed under load and we
1870  * don't want readers to incorrectly assume that the filesystem is no longer
1871  * in use.
1872  */
1873 #define EXT4_MMP_CHECK_MULT		2UL
1874 
1875 /*
1876  * Minimum interval for MMP checking in seconds.
1877  */
1878 #define EXT4_MMP_MIN_CHECK_INTERVAL	5UL
1879 
1880 /*
1881  * Maximum interval for MMP checking in seconds.
1882  */
1883 #define EXT4_MMP_MAX_CHECK_INTERVAL	300UL
1884 
1885 /*
1886  * Function prototypes
1887  */
1888 
1889 /*
1890  * Ok, these declarations are also in <linux/kernel.h> but none of the
1891  * ext4 source programs needs to include it so they are duplicated here.
1892  */
1893 # define NORET_TYPE	/**/
1894 # define ATTRIB_NORET	__attribute__((noreturn))
1895 # define NORET_AND	noreturn,
1896 
1897 /* bitmap.c */
1898 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
1899 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1900 				struct ext4_group_desc *gdp,
1901 				struct buffer_head *bh, int sz);
1902 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1903 				  struct ext4_group_desc *gdp,
1904 				  struct buffer_head *bh, int sz);
1905 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1906 				struct ext4_group_desc *gdp,
1907 				struct buffer_head *bh);
1908 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1909 				  struct ext4_group_desc *gdp,
1910 				  struct buffer_head *bh);
1911 
1912 /* balloc.c */
1913 extern void ext4_validate_block_bitmap(struct super_block *sb,
1914 				       struct ext4_group_desc *desc,
1915 				       unsigned int block_group,
1916 				       struct buffer_head *bh);
1917 extern unsigned int ext4_block_group(struct super_block *sb,
1918 			ext4_fsblk_t blocknr);
1919 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1920 			ext4_fsblk_t blocknr);
1921 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1922 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1923 			ext4_group_t group);
1924 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1925 					 ext4_fsblk_t goal,
1926 					 unsigned int flags,
1927 					 unsigned long *count,
1928 					 int *errp);
1929 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1930 				    s64 nclusters, unsigned int flags);
1931 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1932 extern void ext4_check_blocks_bitmap(struct super_block *);
1933 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1934 						    ext4_group_t block_group,
1935 						    struct buffer_head ** bh);
1936 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1937 
1938 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1939 						ext4_group_t block_group);
1940 extern int ext4_wait_block_bitmap(struct super_block *sb,
1941 				  ext4_group_t block_group,
1942 				  struct buffer_head *bh);
1943 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1944 						  ext4_group_t block_group);
1945 extern void ext4_init_block_bitmap(struct super_block *sb,
1946 				   struct buffer_head *bh,
1947 				   ext4_group_t group,
1948 				   struct ext4_group_desc *desc);
1949 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1950 					      ext4_group_t block_group,
1951 					      struct ext4_group_desc *gdp);
1952 extern unsigned ext4_num_overhead_clusters(struct super_block *sb,
1953 					   ext4_group_t block_group,
1954 					   struct ext4_group_desc *gdp);
1955 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1956 
1957 /* dir.c */
1958 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1959 				  struct file *,
1960 				  struct ext4_dir_entry_2 *,
1961 				  struct buffer_head *, char *, int,
1962 				  unsigned int);
1963 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)	\
1964 	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1965 					(de), (bh), (buf), (size), (offset)))
1966 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1967 				    __u32 minor_hash,
1968 				    struct ext4_dir_entry_2 *dirent);
1969 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1970 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1971 			     struct buffer_head *bh,
1972 			     void *buf, int buf_size,
1973 			     const char *name, int namelen,
1974 			     struct ext4_dir_entry_2 **dest_de);
1975 void ext4_insert_dentry(struct inode *inode,
1976 			struct ext4_dir_entry_2 *de,
1977 			int buf_size,
1978 			const char *name, int namelen);
1979 static inline void ext4_update_dx_flag(struct inode *inode)
1980 {
1981 	if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
1982 				     EXT4_FEATURE_COMPAT_DIR_INDEX))
1983 		ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
1984 }
1985 static unsigned char ext4_filetype_table[] = {
1986 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1987 };
1988 
1989 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
1990 {
1991 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
1992 	    (filetype >= EXT4_FT_MAX))
1993 		return DT_UNKNOWN;
1994 
1995 	return ext4_filetype_table[filetype];
1996 }
1997 
1998 /* fsync.c */
1999 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2000 extern int ext4_flush_unwritten_io(struct inode *);
2001 
2002 /* hash.c */
2003 extern int ext4fs_dirhash(const char *name, int len, struct
2004 			  dx_hash_info *hinfo);
2005 
2006 /* ialloc.c */
2007 extern struct inode *ext4_new_inode(handle_t *, struct inode *, umode_t,
2008 				    const struct qstr *qstr, __u32 goal,
2009 				    uid_t *owner);
2010 extern void ext4_free_inode(handle_t *, struct inode *);
2011 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2012 extern unsigned long ext4_count_free_inodes(struct super_block *);
2013 extern unsigned long ext4_count_dirs(struct super_block *);
2014 extern void ext4_check_inodes_bitmap(struct super_block *);
2015 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2016 extern int ext4_init_inode_table(struct super_block *sb,
2017 				 ext4_group_t group, int barrier);
2018 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2019 
2020 /* mballoc.c */
2021 extern long ext4_mb_stats;
2022 extern long ext4_mb_max_to_scan;
2023 extern int ext4_mb_init(struct super_block *);
2024 extern int ext4_mb_release(struct super_block *);
2025 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2026 				struct ext4_allocation_request *, int *);
2027 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2028 extern void ext4_discard_preallocations(struct inode *);
2029 extern int __init ext4_init_mballoc(void);
2030 extern void ext4_exit_mballoc(void);
2031 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2032 			     struct buffer_head *bh, ext4_fsblk_t block,
2033 			     unsigned long count, int flags);
2034 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2035 				   ext4_group_t ngroups);
2036 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2037 		ext4_group_t i, struct ext4_group_desc *desc);
2038 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2039 				ext4_fsblk_t block, unsigned long count);
2040 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2041 
2042 /* inode.c */
2043 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
2044 						ext4_lblk_t, int, int *);
2045 struct buffer_head *ext4_bread(handle_t *, struct inode *,
2046 						ext4_lblk_t, int, int *);
2047 int ext4_get_block_write(struct inode *inode, sector_t iblock,
2048 			 struct buffer_head *bh_result, int create);
2049 int ext4_get_block(struct inode *inode, sector_t iblock,
2050 				struct buffer_head *bh_result, int create);
2051 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2052 			   struct buffer_head *bh, int create);
2053 int ext4_walk_page_buffers(handle_t *handle,
2054 			   struct buffer_head *head,
2055 			   unsigned from,
2056 			   unsigned to,
2057 			   int *partial,
2058 			   int (*fn)(handle_t *handle,
2059 				     struct buffer_head *bh));
2060 int do_journal_get_write_access(handle_t *handle,
2061 				struct buffer_head *bh);
2062 #define FALL_BACK_TO_NONDELALLOC 1
2063 #define CONVERT_INLINE_DATA	 2
2064 
2065 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2066 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2067 extern int  ext4_setattr(struct dentry *, struct iattr *);
2068 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
2069 				struct kstat *stat);
2070 extern void ext4_evict_inode(struct inode *);
2071 extern void ext4_clear_inode(struct inode *);
2072 extern int  ext4_sync_inode(handle_t *, struct inode *);
2073 extern void ext4_dirty_inode(struct inode *, int);
2074 extern int ext4_change_inode_journal_flag(struct inode *, int);
2075 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2076 extern int ext4_can_truncate(struct inode *inode);
2077 extern void ext4_truncate(struct inode *);
2078 extern int ext4_punch_hole(struct file *file, loff_t offset, loff_t length);
2079 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2080 extern void ext4_set_inode_flags(struct inode *);
2081 extern void ext4_get_inode_flags(struct ext4_inode_info *);
2082 extern int ext4_alloc_da_blocks(struct inode *inode);
2083 extern void ext4_set_aops(struct inode *inode);
2084 extern int ext4_writepage_trans_blocks(struct inode *);
2085 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2086 extern int ext4_discard_partial_page_buffers(handle_t *handle,
2087 		struct address_space *mapping, loff_t from,
2088 		loff_t length, int flags);
2089 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2090 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2091 extern void ext4_da_update_reserve_space(struct inode *inode,
2092 					int used, int quota_claim);
2093 
2094 /* indirect.c */
2095 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2096 				struct ext4_map_blocks *map, int flags);
2097 extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
2098 				const struct iovec *iov, loff_t offset,
2099 				unsigned long nr_segs);
2100 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2101 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk);
2102 extern void ext4_ind_truncate(struct inode *inode);
2103 extern int ext4_ind_punch_hole(struct file *file, loff_t offset, loff_t length);
2104 
2105 /* ioctl.c */
2106 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2107 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2108 
2109 /* migrate.c */
2110 extern int ext4_ext_migrate(struct inode *);
2111 
2112 /* namei.c */
2113 extern int ext4_dirent_csum_verify(struct inode *inode,
2114 				   struct ext4_dir_entry *dirent);
2115 extern int ext4_orphan_add(handle_t *, struct inode *);
2116 extern int ext4_orphan_del(handle_t *, struct inode *);
2117 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2118 				__u32 start_minor_hash, __u32 *next_hash);
2119 extern int search_dir(struct buffer_head *bh,
2120 		      char *search_buf,
2121 		      int buf_size,
2122 		      struct inode *dir,
2123 		      const struct qstr *d_name,
2124 		      unsigned int offset,
2125 		      struct ext4_dir_entry_2 **res_dir);
2126 extern int ext4_generic_delete_entry(handle_t *handle,
2127 				     struct inode *dir,
2128 				     struct ext4_dir_entry_2 *de_del,
2129 				     struct buffer_head *bh,
2130 				     void *entry_buf,
2131 				     int buf_size,
2132 				     int csum_size);
2133 
2134 /* resize.c */
2135 extern int ext4_group_add(struct super_block *sb,
2136 				struct ext4_new_group_data *input);
2137 extern int ext4_group_extend(struct super_block *sb,
2138 				struct ext4_super_block *es,
2139 				ext4_fsblk_t n_blocks_count);
2140 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2141 
2142 /* super.c */
2143 extern int ext4_calculate_overhead(struct super_block *sb);
2144 extern int ext4_superblock_csum_verify(struct super_block *sb,
2145 				       struct ext4_super_block *es);
2146 extern void ext4_superblock_csum_set(struct super_block *sb);
2147 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2148 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2149 extern void ext4_kvfree(void *ptr);
2150 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2151 				    ext4_group_t ngroup);
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 /* namei.c */
2458 extern const struct inode_operations ext4_dir_inode_operations;
2459 extern const struct inode_operations ext4_special_inode_operations;
2460 extern struct dentry *ext4_get_parent(struct dentry *child);
2461 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2462 				 struct ext4_dir_entry_2 *de,
2463 				 int blocksize, int csum_size,
2464 				 unsigned int parent_ino, int dotdot_real_len);
2465 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
2466 				   unsigned int blocksize);
2467 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
2468 					 struct inode *inode,
2469 					 struct buffer_head *bh);
2470 
2471 /* symlink.c */
2472 extern const struct inode_operations ext4_symlink_inode_operations;
2473 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2474 
2475 /* block_validity */
2476 extern void ext4_release_system_zone(struct super_block *sb);
2477 extern int ext4_setup_system_zone(struct super_block *sb);
2478 extern int __init ext4_init_system_zone(void);
2479 extern void ext4_exit_system_zone(void);
2480 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2481 				 ext4_fsblk_t start_blk,
2482 				 unsigned int count);
2483 extern int ext4_check_blockref(const char *, unsigned int,
2484 			       struct inode *, __le32 *, unsigned int);
2485 
2486 /* extents.c */
2487 struct ext4_ext_path;
2488 struct ext4_extent;
2489 
2490 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2491 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2492 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
2493 				       int chunk);
2494 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2495 			       struct ext4_map_blocks *map, int flags);
2496 extern void ext4_ext_truncate(struct inode *);
2497 extern int ext4_ext_punch_hole(struct file *file, loff_t offset,
2498 				loff_t length);
2499 extern void ext4_ext_init(struct super_block *);
2500 extern void ext4_ext_release(struct super_block *);
2501 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2502 			  loff_t len);
2503 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
2504 			  ssize_t len);
2505 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2506 			   struct ext4_map_blocks *map, int flags);
2507 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
2508 					 ext4_lblk_t lblocks);
2509 extern int ext4_extent_tree_init(handle_t *, struct inode *);
2510 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
2511 						   int num,
2512 						   struct ext4_ext_path *path);
2513 extern int ext4_can_extents_be_merged(struct inode *inode,
2514 				      struct ext4_extent *ex1,
2515 				      struct ext4_extent *ex2);
2516 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
2517 				  struct ext4_ext_path *,
2518 				  struct ext4_extent *, int);
2519 extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
2520 						  struct ext4_ext_path *);
2521 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
2522 extern int ext4_ext_check_inode(struct inode *inode);
2523 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
2524 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2525 			__u64 start, __u64 len);
2526 
2527 
2528 /* move_extent.c */
2529 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2530 			     __u64 start_orig, __u64 start_donor,
2531 			     __u64 len, __u64 *moved_len);
2532 
2533 /* page-io.c */
2534 extern int __init ext4_init_pageio(void);
2535 extern void ext4_add_complete_io(ext4_io_end_t *io_end);
2536 extern void ext4_exit_pageio(void);
2537 extern void ext4_ioend_wait(struct inode *);
2538 extern void ext4_free_io_end(ext4_io_end_t *io);
2539 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2540 extern void ext4_end_io_work(struct work_struct *work);
2541 extern void ext4_io_submit(struct ext4_io_submit *io);
2542 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2543 			       struct page *page,
2544 			       int len,
2545 			       struct writeback_control *wbc);
2546 
2547 /* mmp.c */
2548 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2549 extern void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp);
2550 extern int ext4_mmp_csum_verify(struct super_block *sb,
2551 				struct mmp_struct *mmp);
2552 
2553 /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
2554 enum ext4_state_bits {
2555 	BH_Uninit	/* blocks are allocated but uninitialized on disk */
2556 	  = BH_JBDPrivateStart,
2557 	BH_AllocFromCluster,	/* allocated blocks were part of already
2558 				 * allocated cluster. Note that this flag will
2559 				 * never, ever appear in a buffer_head's state
2560 				 * flag. See EXT4_MAP_FROM_CLUSTER to see where
2561 				 * this is used. */
2562 };
2563 
2564 BUFFER_FNS(Uninit, uninit)
2565 TAS_BUFFER_FNS(Uninit, uninit)
2566 
2567 /*
2568  * Add new method to test whether block and inode bitmaps are properly
2569  * initialized. With uninit_bg reading the block from disk is not enough
2570  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2571  */
2572 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2573 
2574 static inline int bitmap_uptodate(struct buffer_head *bh)
2575 {
2576 	return (buffer_uptodate(bh) &&
2577 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2578 }
2579 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2580 {
2581 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2582 }
2583 
2584 /*
2585  * Disable DIO read nolock optimization, so new dioreaders will be forced
2586  * to grab i_mutex
2587  */
2588 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
2589 {
2590 	ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2591 	smp_mb();
2592 }
2593 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
2594 {
2595 	smp_mb();
2596 	ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2597 }
2598 
2599 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
2600 
2601 /* For ioend & aio unwritten conversion wait queues */
2602 #define EXT4_WQ_HASH_SZ		37
2603 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2604 					    EXT4_WQ_HASH_SZ])
2605 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2606 					     EXT4_WQ_HASH_SZ])
2607 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2608 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2609 
2610 #define EXT4_RESIZING	0
2611 extern int ext4_resize_begin(struct super_block *sb);
2612 extern void ext4_resize_end(struct super_block *sb);
2613 
2614 #endif	/* __KERNEL__ */
2615 
2616 #endif	/* _EXT4_H */
2617