xref: /openbmc/linux/fs/ext4/ext4.h (revision 491caa43)
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 #ifdef __KERNEL__
33 #include <linux/compat.h>
34 #endif
35 
36 /*
37  * The fourth extended filesystem constants/structures
38  */
39 
40 /*
41  * Define EXT4FS_DEBUG to produce debug messages
42  */
43 #undef EXT4FS_DEBUG
44 
45 /*
46  * Debug code
47  */
48 #ifdef EXT4FS_DEBUG
49 #define ext4_debug(f, a...)						\
50 	do {								\
51 		printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",	\
52 			__FILE__, __LINE__, __func__);			\
53 		printk(KERN_DEBUG f, ## a);				\
54 	} while (0)
55 #else
56 #define ext4_debug(f, a...)	do {} while (0)
57 #endif
58 
59 #define EXT4_ERROR_INODE(inode, fmt, a...) \
60 	ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
61 
62 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)			\
63 	ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
64 
65 #define EXT4_ERROR_FILE(file, block, fmt, a...)				\
66 	ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
67 
68 /* data type for block offset of block group */
69 typedef int ext4_grpblk_t;
70 
71 /* data type for filesystem-wide blocks number */
72 typedef unsigned long long ext4_fsblk_t;
73 
74 /* data type for file logical block number */
75 typedef __u32 ext4_lblk_t;
76 
77 /* data type for block group number */
78 typedef unsigned int ext4_group_t;
79 
80 /*
81  * Flags used in mballoc's allocation_context flags field.
82  *
83  * Also used to show what's going on for debugging purposes when the
84  * flag field is exported via the traceport interface
85  */
86 
87 /* prefer goal again. length */
88 #define EXT4_MB_HINT_MERGE		0x0001
89 /* blocks already reserved */
90 #define EXT4_MB_HINT_RESERVED		0x0002
91 /* metadata is being allocated */
92 #define EXT4_MB_HINT_METADATA		0x0004
93 /* first blocks in the file */
94 #define EXT4_MB_HINT_FIRST		0x0008
95 /* search for the best chunk */
96 #define EXT4_MB_HINT_BEST		0x0010
97 /* data is being allocated */
98 #define EXT4_MB_HINT_DATA		0x0020
99 /* don't preallocate (for tails) */
100 #define EXT4_MB_HINT_NOPREALLOC		0x0040
101 /* allocate for locality group */
102 #define EXT4_MB_HINT_GROUP_ALLOC	0x0080
103 /* allocate goal blocks or none */
104 #define EXT4_MB_HINT_GOAL_ONLY		0x0100
105 /* goal is meaningful */
106 #define EXT4_MB_HINT_TRY_GOAL		0x0200
107 /* blocks already pre-reserved by delayed allocation */
108 #define EXT4_MB_DELALLOC_RESERVED	0x0400
109 /* We are doing stream allocation */
110 #define EXT4_MB_STREAM_ALLOC		0x0800
111 /* Use reserved root blocks if needed */
112 #define EXT4_MB_USE_ROOT_BLOCKS		0x1000
113 
114 struct ext4_allocation_request {
115 	/* target inode for block we're allocating */
116 	struct inode *inode;
117 	/* how many blocks we want to allocate */
118 	unsigned int len;
119 	/* logical block in target inode */
120 	ext4_lblk_t logical;
121 	/* the closest logical allocated block to the left */
122 	ext4_lblk_t lleft;
123 	/* the closest logical allocated block to the right */
124 	ext4_lblk_t lright;
125 	/* phys. target (a hint) */
126 	ext4_fsblk_t goal;
127 	/* phys. block for the closest logical allocated block to the left */
128 	ext4_fsblk_t pleft;
129 	/* phys. block for the closest logical allocated block to the right */
130 	ext4_fsblk_t pright;
131 	/* flags. see above EXT4_MB_HINT_* */
132 	unsigned int flags;
133 };
134 
135 /*
136  * Logical to physical block mapping, used by ext4_map_blocks()
137  *
138  * This structure is used to pass requests into ext4_map_blocks() as
139  * well as to store the information returned by ext4_map_blocks().  It
140  * takes less room on the stack than a struct buffer_head.
141  */
142 #define EXT4_MAP_NEW		(1 << BH_New)
143 #define EXT4_MAP_MAPPED		(1 << BH_Mapped)
144 #define EXT4_MAP_UNWRITTEN	(1 << BH_Unwritten)
145 #define EXT4_MAP_BOUNDARY	(1 << BH_Boundary)
146 #define EXT4_MAP_UNINIT		(1 << BH_Uninit)
147 /* Sometimes (in the bigalloc case, from ext4_da_get_block_prep) the caller of
148  * ext4_map_blocks wants to know whether or not the underlying cluster has
149  * already been accounted for. EXT4_MAP_FROM_CLUSTER conveys to the caller that
150  * the requested mapping was from previously mapped (or delayed allocated)
151  * cluster. We use BH_AllocFromCluster only for this flag. BH_AllocFromCluster
152  * should never appear on buffer_head's state flags.
153  */
154 #define EXT4_MAP_FROM_CLUSTER	(1 << BH_AllocFromCluster)
155 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
156 				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
157 				 EXT4_MAP_UNINIT | EXT4_MAP_FROM_CLUSTER)
158 
159 struct ext4_map_blocks {
160 	ext4_fsblk_t m_pblk;
161 	ext4_lblk_t m_lblk;
162 	unsigned int m_len;
163 	unsigned int m_flags;
164 };
165 
166 /*
167  * For delayed allocation tracking
168  */
169 struct mpage_da_data {
170 	struct inode *inode;
171 	sector_t b_blocknr;		/* start block number of extent */
172 	size_t b_size;			/* size of extent */
173 	unsigned long b_state;		/* state of the extent */
174 	unsigned long first_page, next_page;	/* extent of pages */
175 	struct writeback_control *wbc;
176 	int io_done;
177 	int pages_written;
178 	int retval;
179 };
180 
181 /*
182  * Flags for ext4_io_end->flags
183  */
184 #define	EXT4_IO_END_UNWRITTEN	0x0001
185 #define EXT4_IO_END_ERROR	0x0002
186 #define EXT4_IO_END_QUEUED	0x0004
187 #define EXT4_IO_END_DIRECT	0x0008
188 #define EXT4_IO_END_IN_FSYNC	0x0010
189 
190 struct ext4_io_page {
191 	struct page	*p_page;
192 	atomic_t	p_count;
193 };
194 
195 #define MAX_IO_PAGES 128
196 
197 typedef struct ext4_io_end {
198 	struct list_head	list;		/* per-file finished IO list */
199 	struct inode		*inode;		/* file being written to */
200 	unsigned int		flag;		/* unwritten or not */
201 	struct page		*page;		/* page struct for buffer write */
202 	loff_t			offset;		/* offset in the file */
203 	ssize_t			size;		/* size of the extent */
204 	struct work_struct	work;		/* data work queue */
205 	struct kiocb		*iocb;		/* iocb struct for AIO */
206 	int			result;		/* error value for AIO */
207 	int			num_io_pages;
208 	struct ext4_io_page	*pages[MAX_IO_PAGES];
209 } ext4_io_end_t;
210 
211 struct ext4_io_submit {
212 	int			io_op;
213 	struct bio		*io_bio;
214 	ext4_io_end_t		*io_end;
215 	struct ext4_io_page	*io_page;
216 	sector_t		io_next_block;
217 };
218 
219 /*
220  * Special inodes numbers
221  */
222 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
223 #define EXT4_ROOT_INO		 2	/* Root inode */
224 #define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
225 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
226 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
227 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
228 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
229 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
230 
231 /* First non-reserved inode for old ext4 filesystems */
232 #define EXT4_GOOD_OLD_FIRST_INO	11
233 
234 /*
235  * Maximal count of links to a file
236  */
237 #define EXT4_LINK_MAX		65000
238 
239 /*
240  * Macro-instructions used to manage several block sizes
241  */
242 #define EXT4_MIN_BLOCK_SIZE		1024
243 #define	EXT4_MAX_BLOCK_SIZE		65536
244 #define EXT4_MIN_BLOCK_LOG_SIZE		10
245 #define EXT4_MAX_BLOCK_LOG_SIZE		16
246 #ifdef __KERNEL__
247 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
248 #else
249 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
250 #endif
251 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
252 #define EXT4_CLUSTER_SIZE(s)		(EXT4_BLOCK_SIZE(s) << \
253 					 EXT4_SB(s)->s_cluster_bits)
254 #ifdef __KERNEL__
255 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
256 # define EXT4_CLUSTER_BITS(s)		(EXT4_SB(s)->s_cluster_bits)
257 #else
258 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
259 #endif
260 #ifdef __KERNEL__
261 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
262 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
263 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
264 #else
265 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
266 				 EXT4_GOOD_OLD_INODE_SIZE : \
267 				 (s)->s_inode_size)
268 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
269 				 EXT4_GOOD_OLD_FIRST_INO : \
270 				 (s)->s_first_ino)
271 #endif
272 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
273 
274 /* Translate a block number to a cluster number */
275 #define EXT4_B2C(sbi, blk)	((blk) >> (sbi)->s_cluster_bits)
276 /* Translate a cluster number to a block number */
277 #define EXT4_C2B(sbi, cluster)	((cluster) << (sbi)->s_cluster_bits)
278 /* Translate # of blks to # of clusters */
279 #define EXT4_NUM_B2C(sbi, blks)	(((blks) + (sbi)->s_cluster_ratio - 1) >> \
280 				 (sbi)->s_cluster_bits)
281 
282 /*
283  * Structure of a blocks group descriptor
284  */
285 struct ext4_group_desc
286 {
287 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
288 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
289 	__le32	bg_inode_table_lo;	/* Inodes table block */
290 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
291 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
292 	__le16	bg_used_dirs_count_lo;	/* Directories count */
293 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
294 	__u32	bg_reserved[2];		/* Likely block/inode bitmap checksum */
295 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
296 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
297 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
298 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
299 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
300 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
301 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
302 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
303 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
304 	__u32	bg_reserved2[3];
305 };
306 
307 /*
308  * Structure of a flex block group info
309  */
310 
311 struct flex_groups {
312 	atomic_t free_inodes;
313 	atomic_t free_clusters;
314 	atomic_t used_dirs;
315 };
316 
317 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
318 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
319 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
320 
321 /*
322  * Macro-instructions used to manage group descriptors
323  */
324 #define EXT4_MIN_DESC_SIZE		32
325 #define EXT4_MIN_DESC_SIZE_64BIT	64
326 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
327 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
328 #ifdef __KERNEL__
329 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
330 # define EXT4_CLUSTERS_PER_GROUP(s)	(EXT4_SB(s)->s_clusters_per_group)
331 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
332 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
333 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
334 #else
335 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
336 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
337 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
338 #endif
339 
340 /*
341  * Constants relative to the data blocks
342  */
343 #define	EXT4_NDIR_BLOCKS		12
344 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
345 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
346 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
347 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
348 
349 /*
350  * Inode flags
351  */
352 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
353 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
354 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
355 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
356 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
357 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
358 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
359 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
360 /* Reserved for compression usage... */
361 #define EXT4_DIRTY_FL			0x00000100
362 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
363 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
364 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
365 /* End compression flags --- maybe not all used */
366 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
367 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
368 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
369 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
370 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
371 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
372 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
373 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
374 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
375 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
376 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
377 
378 #define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
379 #define EXT4_FL_USER_MODIFIABLE		0x004B80FF /* User modifiable flags */
380 
381 /* Flags that should be inherited by new inodes from their parent. */
382 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
383 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
384 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
385 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
386 
387 /* Flags that are appropriate for regular files (all but dir-specific ones). */
388 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
389 
390 /* Flags that are appropriate for non-directories/regular files. */
391 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
392 
393 /* Mask out flags that are inappropriate for the given type of inode. */
394 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
395 {
396 	if (S_ISDIR(mode))
397 		return flags;
398 	else if (S_ISREG(mode))
399 		return flags & EXT4_REG_FLMASK;
400 	else
401 		return flags & EXT4_OTHER_FLMASK;
402 }
403 
404 /*
405  * Inode flags used for atomic set/get
406  */
407 enum {
408 	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
409 	EXT4_INODE_UNRM		= 1,	/* Undelete */
410 	EXT4_INODE_COMPR	= 2,	/* Compress file */
411 	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
412 	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
413 	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
414 	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
415 	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
416 /* Reserved for compression usage... */
417 	EXT4_INODE_DIRTY	= 8,
418 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
419 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
420 	EXT4_INODE_ECOMPR	= 11,	/* Compression error */
421 /* End compression flags --- maybe not all used */
422 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
423 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
424 	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
425 	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
426 	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
427 	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
428 	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
429 	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
430 	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
431 	EXT4_INODE_EOFBLOCKS	= 22,	/* Blocks allocated beyond EOF */
432 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
433 };
434 
435 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
436 #define CHECK_FLAG_VALUE(FLAG) if (!TEST_FLAG_VALUE(FLAG)) { \
437 	printk(KERN_EMERG "EXT4 flag fail: " #FLAG ": %d %d\n", \
438 		EXT4_##FLAG##_FL, EXT4_INODE_##FLAG); BUG_ON(1); }
439 
440 /*
441  * Since it's pretty easy to mix up bit numbers and hex values, and we
442  * can't do a compile-time test for ENUM values, we use a run-time
443  * test to make sure that EXT4_XXX_FL is consistent with respect to
444  * EXT4_INODE_XXX.  If all is well the printk and BUG_ON will all drop
445  * out so it won't cost any extra space in the compiled kernel image.
446  * But it's important that these values are the same, since we are
447  * using EXT4_INODE_XXX to test for the flag values, but EXT4_XX_FL
448  * must be consistent with the values of FS_XXX_FL defined in
449  * include/linux/fs.h and the on-disk values found in ext2, ext3, and
450  * ext4 filesystems, and of course the values defined in e2fsprogs.
451  *
452  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
453  */
454 static inline void ext4_check_flag_values(void)
455 {
456 	CHECK_FLAG_VALUE(SECRM);
457 	CHECK_FLAG_VALUE(UNRM);
458 	CHECK_FLAG_VALUE(COMPR);
459 	CHECK_FLAG_VALUE(SYNC);
460 	CHECK_FLAG_VALUE(IMMUTABLE);
461 	CHECK_FLAG_VALUE(APPEND);
462 	CHECK_FLAG_VALUE(NODUMP);
463 	CHECK_FLAG_VALUE(NOATIME);
464 	CHECK_FLAG_VALUE(DIRTY);
465 	CHECK_FLAG_VALUE(COMPRBLK);
466 	CHECK_FLAG_VALUE(NOCOMPR);
467 	CHECK_FLAG_VALUE(ECOMPR);
468 	CHECK_FLAG_VALUE(INDEX);
469 	CHECK_FLAG_VALUE(IMAGIC);
470 	CHECK_FLAG_VALUE(JOURNAL_DATA);
471 	CHECK_FLAG_VALUE(NOTAIL);
472 	CHECK_FLAG_VALUE(DIRSYNC);
473 	CHECK_FLAG_VALUE(TOPDIR);
474 	CHECK_FLAG_VALUE(HUGE_FILE);
475 	CHECK_FLAG_VALUE(EXTENTS);
476 	CHECK_FLAG_VALUE(EA_INODE);
477 	CHECK_FLAG_VALUE(EOFBLOCKS);
478 	CHECK_FLAG_VALUE(RESERVED);
479 }
480 
481 /* Used to pass group descriptor data when online resize is done */
482 struct ext4_new_group_input {
483 	__u32 group;		/* Group number for this data */
484 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
485 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
486 	__u64 inode_table;	/* Absolute block number of inode table start */
487 	__u32 blocks_count;	/* Total number of blocks in this group */
488 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
489 	__u16 unused;
490 };
491 
492 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
493 struct compat_ext4_new_group_input {
494 	u32 group;
495 	compat_u64 block_bitmap;
496 	compat_u64 inode_bitmap;
497 	compat_u64 inode_table;
498 	u32 blocks_count;
499 	u16 reserved_blocks;
500 	u16 unused;
501 };
502 #endif
503 
504 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
505 struct ext4_new_group_data {
506 	__u32 group;
507 	__u64 block_bitmap;
508 	__u64 inode_bitmap;
509 	__u64 inode_table;
510 	__u32 blocks_count;
511 	__u16 reserved_blocks;
512 	__u16 unused;
513 	__u32 free_blocks_count;
514 };
515 
516 /* Indexes used to index group tables in ext4_new_group_data */
517 enum {
518 	BLOCK_BITMAP = 0,	/* block bitmap */
519 	INODE_BITMAP,		/* inode bitmap */
520 	INODE_TABLE,		/* inode tables */
521 	GROUP_TABLE_COUNT,
522 };
523 
524 /*
525  * Flags used by ext4_map_blocks()
526  */
527 	/* Allocate any needed blocks and/or convert an unitialized
528 	   extent to be an initialized ext4 */
529 #define EXT4_GET_BLOCKS_CREATE			0x0001
530 	/* Request the creation of an unitialized extent */
531 #define EXT4_GET_BLOCKS_UNINIT_EXT		0x0002
532 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\
533 						 EXT4_GET_BLOCKS_CREATE)
534 	/* Caller is from the delayed allocation writeout path,
535 	   so set the magic i_delalloc_reserve_flag after taking the
536 	   inode allocation semaphore for */
537 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
538 	/* caller is from the direct IO path, request to creation of an
539 	unitialized extents if not allocated, split the uninitialized
540 	extent if blocks has been preallocated already*/
541 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
542 #define EXT4_GET_BLOCKS_CONVERT			0x0010
543 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
544 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
545 	/* Convert extent to initialized after IO complete */
546 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
547 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
548 	/* Punch out blocks of an extent */
549 #define EXT4_GET_BLOCKS_PUNCH_OUT_EXT		0x0020
550 	/* Don't normalize allocation size (used for fallocate) */
551 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
552 	/* Request will not result in inode size update (user for fallocate) */
553 #define EXT4_GET_BLOCKS_KEEP_SIZE		0x0080
554 
555 /*
556  * Flags used by ext4_free_blocks
557  */
558 #define EXT4_FREE_BLOCKS_METADATA	0x0001
559 #define EXT4_FREE_BLOCKS_FORGET		0x0002
560 #define EXT4_FREE_BLOCKS_VALIDATED	0x0004
561 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE	0x0008
562 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
563 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
564 
565 /*
566  * Flags used by ext4_discard_partial_page_buffers
567  */
568 #define EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED	0x0001
569 
570 /*
571  * ioctl commands
572  */
573 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
574 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
575 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
576 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
577 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
578 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
579 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
580 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
581 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
582 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
583 #define EXT4_IOC_MIGRATE		_IO('f', 9)
584  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
585  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
586 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
587 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
588 #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
589 
590 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
591 /*
592  * ioctl commands in 32 bit emulation
593  */
594 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
595 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
596 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
597 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
598 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
599 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
600 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
601 #define EXT4_IOC32_GROUP_ADD		_IOW('f', 8, struct compat_ext4_new_group_input)
602 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
603 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
604 #endif
605 
606 /* Max physical block we can address w/o extents */
607 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
608 
609 /*
610  * Structure of an inode on the disk
611  */
612 struct ext4_inode {
613 	__le16	i_mode;		/* File mode */
614 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
615 	__le32	i_size_lo;	/* Size in bytes */
616 	__le32	i_atime;	/* Access time */
617 	__le32	i_ctime;	/* Inode Change time */
618 	__le32	i_mtime;	/* Modification time */
619 	__le32	i_dtime;	/* Deletion Time */
620 	__le16	i_gid;		/* Low 16 bits of Group Id */
621 	__le16	i_links_count;	/* Links count */
622 	__le32	i_blocks_lo;	/* Blocks count */
623 	__le32	i_flags;	/* File flags */
624 	union {
625 		struct {
626 			__le32  l_i_version;
627 		} linux1;
628 		struct {
629 			__u32  h_i_translator;
630 		} hurd1;
631 		struct {
632 			__u32  m_i_reserved1;
633 		} masix1;
634 	} osd1;				/* OS dependent 1 */
635 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
636 	__le32	i_generation;	/* File version (for NFS) */
637 	__le32	i_file_acl_lo;	/* File ACL */
638 	__le32	i_size_high;
639 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
640 	union {
641 		struct {
642 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
643 			__le16	l_i_file_acl_high;
644 			__le16	l_i_uid_high;	/* these 2 fields */
645 			__le16	l_i_gid_high;	/* were reserved2[0] */
646 			__u32	l_i_reserved2;
647 		} linux2;
648 		struct {
649 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
650 			__u16	h_i_mode_high;
651 			__u16	h_i_uid_high;
652 			__u16	h_i_gid_high;
653 			__u32	h_i_author;
654 		} hurd2;
655 		struct {
656 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
657 			__le16	m_i_file_acl_high;
658 			__u32	m_i_reserved2[2];
659 		} masix2;
660 	} osd2;				/* OS dependent 2 */
661 	__le16	i_extra_isize;
662 	__le16	i_pad1;
663 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
664 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
665 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
666 	__le32  i_crtime;       /* File Creation time */
667 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
668 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
669 };
670 
671 struct move_extent {
672 	__u32 reserved;		/* should be zero */
673 	__u32 donor_fd;		/* donor file descriptor */
674 	__u64 orig_start;	/* logical start offset in block for orig */
675 	__u64 donor_start;	/* logical start offset in block for donor */
676 	__u64 len;		/* block length to be moved */
677 	__u64 moved_len;	/* moved block length */
678 };
679 
680 #define EXT4_EPOCH_BITS 2
681 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
682 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
683 
684 /*
685  * Extended fields will fit into an inode if the filesystem was formatted
686  * with large inodes (-I 256 or larger) and there are not currently any EAs
687  * consuming all of the available space. For new inodes we always reserve
688  * enough space for the kernel's known extended fields, but for inodes
689  * created with an old kernel this might not have been the case. None of
690  * the extended inode fields is critical for correct filesystem operation.
691  * This macro checks if a certain field fits in the inode. Note that
692  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
693  */
694 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
695 	((offsetof(typeof(*ext4_inode), field) +	\
696 	  sizeof((ext4_inode)->field))			\
697 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
698 	    (einode)->i_extra_isize))			\
699 
700 static inline __le32 ext4_encode_extra_time(struct timespec *time)
701 {
702        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
703 			   (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
704                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
705 }
706 
707 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
708 {
709        if (sizeof(time->tv_sec) > 4)
710 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
711 			       << 32;
712        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
713 }
714 
715 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
716 do {									       \
717 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
718 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
719 		(raw_inode)->xtime ## _extra =				       \
720 				ext4_encode_extra_time(&(inode)->xtime);       \
721 } while (0)
722 
723 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
724 do {									       \
725 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
726 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
727 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
728 		(raw_inode)->xtime ## _extra =				       \
729 				ext4_encode_extra_time(&(einode)->xtime);      \
730 } while (0)
731 
732 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
733 do {									       \
734 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
735 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
736 		ext4_decode_extra_time(&(inode)->xtime,			       \
737 				       raw_inode->xtime ## _extra);	       \
738 	else								       \
739 		(inode)->xtime.tv_nsec = 0;				       \
740 } while (0)
741 
742 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
743 do {									       \
744 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
745 		(einode)->xtime.tv_sec = 				       \
746 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
747 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
748 		ext4_decode_extra_time(&(einode)->xtime,		       \
749 				       raw_inode->xtime ## _extra);	       \
750 	else								       \
751 		(einode)->xtime.tv_nsec = 0;				       \
752 } while (0)
753 
754 #define i_disk_version osd1.linux1.l_i_version
755 
756 #if defined(__KERNEL__) || defined(__linux__)
757 #define i_reserved1	osd1.linux1.l_i_reserved1
758 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
759 #define i_blocks_high	osd2.linux2.l_i_blocks_high
760 #define i_uid_low	i_uid
761 #define i_gid_low	i_gid
762 #define i_uid_high	osd2.linux2.l_i_uid_high
763 #define i_gid_high	osd2.linux2.l_i_gid_high
764 #define i_reserved2	osd2.linux2.l_i_reserved2
765 
766 #elif defined(__GNU__)
767 
768 #define i_translator	osd1.hurd1.h_i_translator
769 #define i_uid_high	osd2.hurd2.h_i_uid_high
770 #define i_gid_high	osd2.hurd2.h_i_gid_high
771 #define i_author	osd2.hurd2.h_i_author
772 
773 #elif defined(__masix__)
774 
775 #define i_reserved1	osd1.masix1.m_i_reserved1
776 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
777 #define i_reserved2	osd2.masix2.m_i_reserved2
778 
779 #endif /* defined(__KERNEL__) || defined(__linux__) */
780 
781 /*
782  * storage for cached extent
783  * If ec_len == 0, then the cache is invalid.
784  * If ec_start == 0, then the cache represents a gap (null mapping)
785  */
786 struct ext4_ext_cache {
787 	ext4_fsblk_t	ec_start;
788 	ext4_lblk_t	ec_block;
789 	__u32		ec_len; /* must be 32bit to return holes */
790 };
791 
792 /*
793  * fourth extended file system inode data in memory
794  */
795 struct ext4_inode_info {
796 	__le32	i_data[15];	/* unconverted */
797 	__u32	i_dtime;
798 	ext4_fsblk_t	i_file_acl;
799 
800 	/*
801 	 * i_block_group is the number of the block group which contains
802 	 * this file's inode.  Constant across the lifetime of the inode,
803 	 * it is ued for making block allocation decisions - we try to
804 	 * place a file's data blocks near its inode block, and new inodes
805 	 * near to their parent directory's inode.
806 	 */
807 	ext4_group_t	i_block_group;
808 	ext4_lblk_t	i_dir_start_lookup;
809 #if (BITS_PER_LONG < 64)
810 	unsigned long	i_state_flags;		/* Dynamic state flags */
811 #endif
812 	unsigned long	i_flags;
813 
814 #ifdef CONFIG_EXT4_FS_XATTR
815 	/*
816 	 * Extended attributes can be read independently of the main file
817 	 * data. Taking i_mutex even when reading would cause contention
818 	 * between readers of EAs and writers of regular file data, so
819 	 * instead we synchronize on xattr_sem when reading or changing
820 	 * EAs.
821 	 */
822 	struct rw_semaphore xattr_sem;
823 #endif
824 
825 	struct list_head i_orphan;	/* unlinked but open inodes */
826 
827 	/*
828 	 * i_disksize keeps track of what the inode size is ON DISK, not
829 	 * in memory.  During truncate, i_size is set to the new size by
830 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
831 	 * set i_disksize to 0 until the truncate is actually under way.
832 	 *
833 	 * The intent is that i_disksize always represents the blocks which
834 	 * are used by this file.  This allows recovery to restart truncate
835 	 * on orphans if we crash during truncate.  We actually write i_disksize
836 	 * into the on-disk inode when writing inodes out, instead of i_size.
837 	 *
838 	 * The only time when i_disksize and i_size may be different is when
839 	 * a truncate is in progress.  The only things which change i_disksize
840 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
841 	 */
842 	loff_t	i_disksize;
843 
844 	/*
845 	 * i_data_sem is for serialising ext4_truncate() against
846 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
847 	 * data tree are chopped off during truncate. We can't do that in
848 	 * ext4 because whenever we perform intermediate commits during
849 	 * truncate, the inode and all the metadata blocks *must* be in a
850 	 * consistent state which allows truncation of the orphans to restart
851 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
852 	 * by other means, so we have i_data_sem.
853 	 */
854 	struct rw_semaphore i_data_sem;
855 	struct inode vfs_inode;
856 	struct jbd2_inode *jinode;
857 
858 	struct ext4_ext_cache i_cached_extent;
859 	/*
860 	 * File creation time. Its function is same as that of
861 	 * struct timespec i_{a,c,m}time in the generic inode.
862 	 */
863 	struct timespec i_crtime;
864 
865 	/* mballoc */
866 	struct list_head i_prealloc_list;
867 	spinlock_t i_prealloc_lock;
868 
869 	/* ialloc */
870 	ext4_group_t	i_last_alloc_group;
871 
872 	/* allocation reservation info for delalloc */
873 	/* In case of bigalloc, these refer to clusters rather than blocks */
874 	unsigned int i_reserved_data_blocks;
875 	unsigned int i_reserved_meta_blocks;
876 	unsigned int i_allocated_meta_blocks;
877 	ext4_lblk_t i_da_metadata_calc_last_lblock;
878 	int i_da_metadata_calc_len;
879 
880 	/* on-disk additional length */
881 	__u16 i_extra_isize;
882 
883 #ifdef CONFIG_QUOTA
884 	/* quota space reservation, managed internally by quota code */
885 	qsize_t i_reserved_quota;
886 #endif
887 
888 	/* completed IOs that might need unwritten extents handling */
889 	struct list_head i_completed_io_list;
890 	spinlock_t i_completed_io_lock;
891 	atomic_t i_ioend_count;	/* Number of outstanding io_end structs */
892 	/* current io_end structure for async DIO write*/
893 	ext4_io_end_t *cur_aio_dio;
894 	atomic_t i_aiodio_unwritten; /* Nr. of inflight conversions pending */
895 
896 	spinlock_t i_block_reservation_lock;
897 
898 	/*
899 	 * Transactions that contain inode's metadata needed to complete
900 	 * fsync and fdatasync, respectively.
901 	 */
902 	tid_t i_sync_tid;
903 	tid_t i_datasync_tid;
904 };
905 
906 /*
907  * File system states
908  */
909 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
910 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
911 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
912 
913 /*
914  * Misc. filesystem flags
915  */
916 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
917 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
918 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
919 
920 /*
921  * Mount flags
922  */
923 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
924 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
925 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
926 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
927 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
928 #define EXT4_MOUNT_ERRORS_MASK		0x00070
929 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
930 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
931 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
932 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
933 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
934 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
935 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
936 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
937 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
938 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
939 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
940 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
941 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
942 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
943 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
944 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
945 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
946 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
947 #define EXT4_MOUNT_MBLK_IO_SUBMIT	0x4000000 /* multi-block io submits */
948 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
949 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
950 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
951 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
952 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
953 
954 #define EXT4_MOUNT2_EXPLICIT_DELALLOC	0x00000001 /* User explicitly
955 						      specified delalloc */
956 
957 #define clear_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt &= \
958 						~EXT4_MOUNT_##opt
959 #define set_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt |= \
960 						EXT4_MOUNT_##opt
961 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
962 					 EXT4_MOUNT_##opt)
963 
964 #define clear_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 &= \
965 						~EXT4_MOUNT2_##opt
966 #define set_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 |= \
967 						EXT4_MOUNT2_##opt
968 #define test_opt2(sb, opt)		(EXT4_SB(sb)->s_mount_opt2 & \
969 					 EXT4_MOUNT2_##opt)
970 
971 #define ext4_test_and_set_bit		__test_and_set_bit_le
972 #define ext4_set_bit			__set_bit_le
973 #define ext4_set_bit_atomic		ext2_set_bit_atomic
974 #define ext4_test_and_clear_bit		__test_and_clear_bit_le
975 #define ext4_clear_bit			__clear_bit_le
976 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
977 #define ext4_test_bit			test_bit_le
978 #define ext4_find_next_zero_bit		find_next_zero_bit_le
979 #define ext4_find_next_bit		find_next_bit_le
980 
981 extern void ext4_set_bits(void *bm, int cur, int len);
982 
983 /*
984  * Maximal mount counts between two filesystem checks
985  */
986 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
987 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
988 
989 /*
990  * Behaviour when detecting errors
991  */
992 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
993 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
994 #define EXT4_ERRORS_PANIC		3	/* Panic */
995 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
996 
997 /*
998  * Structure of the super block
999  */
1000 struct ext4_super_block {
1001 /*00*/	__le32	s_inodes_count;		/* Inodes count */
1002 	__le32	s_blocks_count_lo;	/* Blocks count */
1003 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
1004 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
1005 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
1006 	__le32	s_first_data_block;	/* First Data Block */
1007 	__le32	s_log_block_size;	/* Block size */
1008 	__le32	s_log_cluster_size;	/* Allocation cluster size */
1009 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
1010 	__le32	s_clusters_per_group;	/* # Clusters per group */
1011 	__le32	s_inodes_per_group;	/* # Inodes per group */
1012 	__le32	s_mtime;		/* Mount time */
1013 /*30*/	__le32	s_wtime;		/* Write time */
1014 	__le16	s_mnt_count;		/* Mount count */
1015 	__le16	s_max_mnt_count;	/* Maximal mount count */
1016 	__le16	s_magic;		/* Magic signature */
1017 	__le16	s_state;		/* File system state */
1018 	__le16	s_errors;		/* Behaviour when detecting errors */
1019 	__le16	s_minor_rev_level;	/* minor revision level */
1020 /*40*/	__le32	s_lastcheck;		/* time of last check */
1021 	__le32	s_checkinterval;	/* max. time between checks */
1022 	__le32	s_creator_os;		/* OS */
1023 	__le32	s_rev_level;		/* Revision level */
1024 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
1025 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
1026 	/*
1027 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
1028 	 *
1029 	 * Note: the difference between the compatible feature set and
1030 	 * the incompatible feature set is that if there is a bit set
1031 	 * in the incompatible feature set that the kernel doesn't
1032 	 * know about, it should refuse to mount the filesystem.
1033 	 *
1034 	 * e2fsck's requirements are more strict; if it doesn't know
1035 	 * about a feature in either the compatible or incompatible
1036 	 * feature set, it must abort and not try to meddle with
1037 	 * things it doesn't understand...
1038 	 */
1039 	__le32	s_first_ino;		/* First non-reserved inode */
1040 	__le16  s_inode_size;		/* size of inode structure */
1041 	__le16	s_block_group_nr;	/* block group # of this superblock */
1042 	__le32	s_feature_compat;	/* compatible feature set */
1043 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
1044 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
1045 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
1046 /*78*/	char	s_volume_name[16];	/* volume name */
1047 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
1048 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
1049 	/*
1050 	 * Performance hints.  Directory preallocation should only
1051 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1052 	 */
1053 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
1054 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
1055 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
1056 	/*
1057 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1058 	 */
1059 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
1060 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
1061 	__le32	s_journal_dev;		/* device number of journal file */
1062 	__le32	s_last_orphan;		/* start of list of inodes to delete */
1063 	__le32	s_hash_seed[4];		/* HTREE hash seed */
1064 	__u8	s_def_hash_version;	/* Default hash version to use */
1065 	__u8	s_jnl_backup_type;
1066 	__le16  s_desc_size;		/* size of group descriptor */
1067 /*100*/	__le32	s_default_mount_opts;
1068 	__le32	s_first_meta_bg;	/* First metablock block group */
1069 	__le32	s_mkfs_time;		/* When the filesystem was created */
1070 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
1071 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1072 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
1073 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
1074 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
1075 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
1076 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
1077 	__le32	s_flags;		/* Miscellaneous flags */
1078 	__le16  s_raid_stride;		/* RAID stride */
1079 	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1080 	__le64  s_mmp_block;            /* Block for multi-mount protection */
1081 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1082 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
1083 	__u8	s_reserved_char_pad;
1084 	__le16  s_reserved_pad;
1085 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1086 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
1087 	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
1088 	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
1089 					      snapshot's future use */
1090 	__le32	s_snapshot_list;	/* inode number of the head of the
1091 					   on-disk snapshot list */
1092 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1093 	__le32	s_error_count;		/* number of fs errors */
1094 	__le32	s_first_error_time;	/* first time an error happened */
1095 	__le32	s_first_error_ino;	/* inode involved in first error */
1096 	__le64	s_first_error_block;	/* block involved of first error */
1097 	__u8	s_first_error_func[32];	/* function where the error happened */
1098 	__le32	s_first_error_line;	/* line number where error happened */
1099 	__le32	s_last_error_time;	/* most recent time of an error */
1100 	__le32	s_last_error_ino;	/* inode involved in last error */
1101 	__le32	s_last_error_line;	/* line number where error happened */
1102 	__le64	s_last_error_block;	/* block involved of last error */
1103 	__u8	s_last_error_func[32];	/* function where the error happened */
1104 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1105 	__u8	s_mount_opts[64];
1106 	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
1107 	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
1108 	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
1109 	__le32  s_reserved[109];        /* Padding to the end of the block */
1110 };
1111 
1112 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1113 
1114 #ifdef __KERNEL__
1115 
1116 /*
1117  * run-time mount flags
1118  */
1119 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
1120 #define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
1121 
1122 /*
1123  * fourth extended-fs super-block data in memory
1124  */
1125 struct ext4_sb_info {
1126 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
1127 	unsigned long s_inodes_per_block;/* Number of inodes per block */
1128 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
1129 	unsigned long s_clusters_per_group; /* Number of clusters in a group */
1130 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
1131 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
1132 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
1133 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
1134 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1135 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1136 	unsigned long s_overhead_last;  /* Last calculated overhead */
1137 	unsigned long s_blocks_last;    /* Last seen block count */
1138 	unsigned int s_cluster_ratio;	/* Number of blocks per cluster */
1139 	unsigned int s_cluster_bits;	/* log2 of s_cluster_ratio */
1140 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
1141 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
1142 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
1143 	struct buffer_head **s_group_desc;
1144 	unsigned int s_mount_opt;
1145 	unsigned int s_mount_opt2;
1146 	unsigned int s_mount_flags;
1147 	unsigned int s_def_mount_opt;
1148 	ext4_fsblk_t s_sb_block;
1149 	uid_t s_resuid;
1150 	gid_t s_resgid;
1151 	unsigned short s_mount_state;
1152 	unsigned short s_pad;
1153 	int s_addr_per_block_bits;
1154 	int s_desc_per_block_bits;
1155 	int s_inode_size;
1156 	int s_first_ino;
1157 	unsigned int s_inode_readahead_blks;
1158 	unsigned int s_inode_goal;
1159 	spinlock_t s_next_gen_lock;
1160 	u32 s_next_generation;
1161 	u32 s_hash_seed[4];
1162 	int s_def_hash_version;
1163 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
1164 	struct percpu_counter s_freeclusters_counter;
1165 	struct percpu_counter s_freeinodes_counter;
1166 	struct percpu_counter s_dirs_counter;
1167 	struct percpu_counter s_dirtyclusters_counter;
1168 	struct blockgroup_lock *s_blockgroup_lock;
1169 	struct proc_dir_entry *s_proc;
1170 	struct kobject s_kobj;
1171 	struct completion s_kobj_unregister;
1172 
1173 	/* Journaling */
1174 	struct journal_s *s_journal;
1175 	struct list_head s_orphan;
1176 	struct mutex s_orphan_lock;
1177 	unsigned long s_resize_flags;		/* Flags indicating if there
1178 						   is a resizer */
1179 	unsigned long s_commit_interval;
1180 	u32 s_max_batch_time;
1181 	u32 s_min_batch_time;
1182 	struct block_device *journal_bdev;
1183 #ifdef CONFIG_QUOTA
1184 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
1185 	int s_jquota_fmt;			/* Format of quota to use */
1186 #endif
1187 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1188 	struct rb_root system_blks;
1189 
1190 #ifdef EXTENTS_STATS
1191 	/* ext4 extents stats */
1192 	unsigned long s_ext_min;
1193 	unsigned long s_ext_max;
1194 	unsigned long s_depth_max;
1195 	spinlock_t s_ext_stats_lock;
1196 	unsigned long s_ext_blocks;
1197 	unsigned long s_ext_extents;
1198 #endif
1199 	/* ext4 extent cache stats */
1200 	unsigned long extent_cache_hits;
1201 	unsigned long extent_cache_misses;
1202 
1203 	/* for buddy allocator */
1204 	struct ext4_group_info ***s_group_info;
1205 	struct inode *s_buddy_cache;
1206 	spinlock_t s_md_lock;
1207 	unsigned short *s_mb_offsets;
1208 	unsigned int *s_mb_maxs;
1209 
1210 	/* tunables */
1211 	unsigned long s_stripe;
1212 	unsigned int s_mb_stream_request;
1213 	unsigned int s_mb_max_to_scan;
1214 	unsigned int s_mb_min_to_scan;
1215 	unsigned int s_mb_stats;
1216 	unsigned int s_mb_order2_reqs;
1217 	unsigned int s_mb_group_prealloc;
1218 	unsigned int s_max_writeback_mb_bump;
1219 	/* where last allocation was done - for stream allocation */
1220 	unsigned long s_mb_last_group;
1221 	unsigned long s_mb_last_start;
1222 
1223 	/* stats for buddy allocator */
1224 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1225 	atomic_t s_bal_success;	/* we found long enough chunks */
1226 	atomic_t s_bal_allocated;	/* in blocks */
1227 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1228 	atomic_t s_bal_goals;	/* goal hits */
1229 	atomic_t s_bal_breaks;	/* too long searches */
1230 	atomic_t s_bal_2orders;	/* 2^order hits */
1231 	spinlock_t s_bal_lock;
1232 	unsigned long s_mb_buddies_generated;
1233 	unsigned long long s_mb_generation_time;
1234 	atomic_t s_mb_lost_chunks;
1235 	atomic_t s_mb_preallocated;
1236 	atomic_t s_mb_discarded;
1237 	atomic_t s_lock_busy;
1238 
1239 	/* locality groups */
1240 	struct ext4_locality_group __percpu *s_locality_groups;
1241 
1242 	/* for write statistics */
1243 	unsigned long s_sectors_written_start;
1244 	u64 s_kbytes_written;
1245 
1246 	unsigned int s_log_groups_per_flex;
1247 	struct flex_groups *s_flex_groups;
1248 
1249 	/* workqueue for dio unwritten */
1250 	struct workqueue_struct *dio_unwritten_wq;
1251 
1252 	/* timer for periodic error stats printing */
1253 	struct timer_list s_err_report;
1254 
1255 	/* Lazy inode table initialization info */
1256 	struct ext4_li_request *s_li_request;
1257 	/* Wait multiplier for lazy initialization thread */
1258 	unsigned int s_li_wait_mult;
1259 
1260 	/* Kernel thread for multiple mount protection */
1261 	struct task_struct *s_mmp_tsk;
1262 
1263 	/* record the last minlen when FITRIM is called. */
1264 	atomic_t s_last_trim_minblks;
1265 };
1266 
1267 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1268 {
1269 	return sb->s_fs_info;
1270 }
1271 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1272 {
1273 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1274 }
1275 
1276 static inline struct timespec ext4_current_time(struct inode *inode)
1277 {
1278 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1279 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1280 }
1281 
1282 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1283 {
1284 	return ino == EXT4_ROOT_INO ||
1285 		ino == EXT4_JOURNAL_INO ||
1286 		ino == EXT4_RESIZE_INO ||
1287 		(ino >= EXT4_FIRST_INO(sb) &&
1288 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1289 }
1290 
1291 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1292 					      struct ext4_io_end *io_end)
1293 {
1294 	if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1295 		io_end->flag |= EXT4_IO_END_UNWRITTEN;
1296 		atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
1297 	}
1298 }
1299 
1300 /*
1301  * Inode dynamic state flags
1302  */
1303 enum {
1304 	EXT4_STATE_JDATA,		/* journaled data exists */
1305 	EXT4_STATE_NEW,			/* inode is newly created */
1306 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1307 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1308 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1309 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1310 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1311 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1312 	EXT4_STATE_DELALLOC_RESERVED,	/* blks already reserved for delalloc */
1313 };
1314 
1315 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
1316 static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
1317 {									\
1318 	return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);	\
1319 }									\
1320 static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
1321 {									\
1322 	set_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1323 }									\
1324 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1325 {									\
1326 	clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1327 }
1328 
1329 EXT4_INODE_BIT_FNS(flag, flags, 0)
1330 #if (BITS_PER_LONG < 64)
1331 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1332 
1333 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1334 {
1335 	(ei)->i_state_flags = 0;
1336 }
1337 #else
1338 EXT4_INODE_BIT_FNS(state, flags, 32)
1339 
1340 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1341 {
1342 	/* We depend on the fact that callers will set i_flags */
1343 }
1344 #endif
1345 #else
1346 /* Assume that user mode programs are passing in an ext4fs superblock, not
1347  * a kernel struct super_block.  This will allow us to call the feature-test
1348  * macros from user land. */
1349 #define EXT4_SB(sb)	(sb)
1350 #endif
1351 
1352 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1353 
1354 /*
1355  * Codes for operating systems
1356  */
1357 #define EXT4_OS_LINUX		0
1358 #define EXT4_OS_HURD		1
1359 #define EXT4_OS_MASIX		2
1360 #define EXT4_OS_FREEBSD		3
1361 #define EXT4_OS_LITES		4
1362 
1363 /*
1364  * Revision levels
1365  */
1366 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1367 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1368 
1369 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1370 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1371 
1372 #define EXT4_GOOD_OLD_INODE_SIZE 128
1373 
1374 /*
1375  * Feature set definitions
1376  */
1377 
1378 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1379 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1380 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1381 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1382 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1383 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1384 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1385 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1386 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1387 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1388 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1389 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1390 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1391 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1392 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1393 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1394 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1395 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1396 
1397 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1398 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1399 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1400 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1401 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1402 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1403 
1404 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1405 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1406 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1407 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1408 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1409 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1410 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1411 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
1412 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
1413 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
1414 
1415 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1416 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1417 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1418 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1419 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1420 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1421 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1422 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1423 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1424 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1425 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1426 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM	0x2000 /* use crc32c for bg */
1427 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
1428 #define EXT4_FEATURE_INCOMPAT_INLINEDATA	0x8000 /* data in inode */
1429 
1430 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1431 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1432 					 EXT4_FEATURE_INCOMPAT_META_BG)
1433 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1434 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1435 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1436 
1437 #define EXT3_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1438 #define EXT3_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1439 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1440 					 EXT4_FEATURE_INCOMPAT_META_BG)
1441 #define EXT3_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1442 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1443 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1444 
1445 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1446 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1447 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1448 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1449 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1450 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1451 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1452 					 EXT4_FEATURE_INCOMPAT_MMP)
1453 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1454 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1455 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1456 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1457 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1458 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1459 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1460 					 EXT4_FEATURE_RO_COMPAT_BIGALLOC)
1461 
1462 /*
1463  * Default values for user and/or group using reserved blocks
1464  */
1465 #define	EXT4_DEF_RESUID		0
1466 #define	EXT4_DEF_RESGID		0
1467 
1468 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1469 
1470 /*
1471  * Default mount options
1472  */
1473 #define EXT4_DEFM_DEBUG		0x0001
1474 #define EXT4_DEFM_BSDGROUPS	0x0002
1475 #define EXT4_DEFM_XATTR_USER	0x0004
1476 #define EXT4_DEFM_ACL		0x0008
1477 #define EXT4_DEFM_UID16		0x0010
1478 #define EXT4_DEFM_JMODE		0x0060
1479 #define EXT4_DEFM_JMODE_DATA	0x0020
1480 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1481 #define EXT4_DEFM_JMODE_WBACK	0x0060
1482 #define EXT4_DEFM_NOBARRIER	0x0100
1483 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1484 #define EXT4_DEFM_DISCARD	0x0400
1485 #define EXT4_DEFM_NODELALLOC	0x0800
1486 
1487 /*
1488  * Default journal batch times
1489  */
1490 #define EXT4_DEF_MIN_BATCH_TIME	0
1491 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1492 
1493 /*
1494  * Minimum number of groups in a flexgroup before we separate out
1495  * directories into the first block group of a flexgroup
1496  */
1497 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1498 
1499 /*
1500  * Structure of a directory entry
1501  */
1502 #define EXT4_NAME_LEN 255
1503 
1504 struct ext4_dir_entry {
1505 	__le32	inode;			/* Inode number */
1506 	__le16	rec_len;		/* Directory entry length */
1507 	__le16	name_len;		/* Name length */
1508 	char	name[EXT4_NAME_LEN];	/* File name */
1509 };
1510 
1511 /*
1512  * The new version of the directory entry.  Since EXT4 structures are
1513  * stored in intel byte order, and the name_len field could never be
1514  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1515  * file_type field.
1516  */
1517 struct ext4_dir_entry_2 {
1518 	__le32	inode;			/* Inode number */
1519 	__le16	rec_len;		/* Directory entry length */
1520 	__u8	name_len;		/* Name length */
1521 	__u8	file_type;
1522 	char	name[EXT4_NAME_LEN];	/* File name */
1523 };
1524 
1525 /*
1526  * Ext4 directory file types.  Only the low 3 bits are used.  The
1527  * other bits are reserved for now.
1528  */
1529 #define EXT4_FT_UNKNOWN		0
1530 #define EXT4_FT_REG_FILE	1
1531 #define EXT4_FT_DIR		2
1532 #define EXT4_FT_CHRDEV		3
1533 #define EXT4_FT_BLKDEV		4
1534 #define EXT4_FT_FIFO		5
1535 #define EXT4_FT_SOCK		6
1536 #define EXT4_FT_SYMLINK		7
1537 
1538 #define EXT4_FT_MAX		8
1539 
1540 /*
1541  * EXT4_DIR_PAD defines the directory entries boundaries
1542  *
1543  * NOTE: It must be a multiple of 4
1544  */
1545 #define EXT4_DIR_PAD			4
1546 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1547 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1548 					 ~EXT4_DIR_ROUND)
1549 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1550 
1551 /*
1552  * If we ever get support for fs block sizes > page_size, we'll need
1553  * to remove the #if statements in the next two functions...
1554  */
1555 static inline unsigned int
1556 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1557 {
1558 	unsigned len = le16_to_cpu(dlen);
1559 
1560 #if (PAGE_CACHE_SIZE >= 65536)
1561 	if (len == EXT4_MAX_REC_LEN || len == 0)
1562 		return blocksize;
1563 	return (len & 65532) | ((len & 3) << 16);
1564 #else
1565 	return len;
1566 #endif
1567 }
1568 
1569 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1570 {
1571 	if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1572 		BUG();
1573 #if (PAGE_CACHE_SIZE >= 65536)
1574 	if (len < 65536)
1575 		return cpu_to_le16(len);
1576 	if (len == blocksize) {
1577 		if (blocksize == 65536)
1578 			return cpu_to_le16(EXT4_MAX_REC_LEN);
1579 		else
1580 			return cpu_to_le16(0);
1581 	}
1582 	return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1583 #else
1584 	return cpu_to_le16(len);
1585 #endif
1586 }
1587 
1588 /*
1589  * Hash Tree Directory indexing
1590  * (c) Daniel Phillips, 2001
1591  */
1592 
1593 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1594 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1595 		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1596 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1597 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1598 
1599 /* Legal values for the dx_root hash_version field: */
1600 
1601 #define DX_HASH_LEGACY		0
1602 #define DX_HASH_HALF_MD4	1
1603 #define DX_HASH_TEA		2
1604 #define DX_HASH_LEGACY_UNSIGNED	3
1605 #define DX_HASH_HALF_MD4_UNSIGNED	4
1606 #define DX_HASH_TEA_UNSIGNED		5
1607 
1608 #ifdef __KERNEL__
1609 
1610 /* hash info structure used by the directory hash */
1611 struct dx_hash_info
1612 {
1613 	u32		hash;
1614 	u32		minor_hash;
1615 	int		hash_version;
1616 	u32		*seed;
1617 };
1618 
1619 #define EXT4_HTREE_EOF	0x7fffffff
1620 
1621 /*
1622  * Control parameters used by ext4_htree_next_block
1623  */
1624 #define HASH_NB_ALWAYS		1
1625 
1626 
1627 /*
1628  * Describe an inode's exact location on disk and in memory
1629  */
1630 struct ext4_iloc
1631 {
1632 	struct buffer_head *bh;
1633 	unsigned long offset;
1634 	ext4_group_t block_group;
1635 };
1636 
1637 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1638 {
1639 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1640 }
1641 
1642 /*
1643  * This structure is stuffed into the struct file's private_data field
1644  * for directories.  It is where we put information so that we can do
1645  * readdir operations in hash tree order.
1646  */
1647 struct dir_private_info {
1648 	struct rb_root	root;
1649 	struct rb_node	*curr_node;
1650 	struct fname	*extra_fname;
1651 	loff_t		last_pos;
1652 	__u32		curr_hash;
1653 	__u32		curr_minor_hash;
1654 	__u32		next_hash;
1655 };
1656 
1657 /* calculate the first block number of the group */
1658 static inline ext4_fsblk_t
1659 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1660 {
1661 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1662 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1663 }
1664 
1665 /*
1666  * Special error return code only used by dx_probe() and its callers.
1667  */
1668 #define ERR_BAD_DX_DIR	-75000
1669 
1670 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1671 			ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1672 
1673 /*
1674  * Timeout and state flag for lazy initialization inode thread.
1675  */
1676 #define EXT4_DEF_LI_WAIT_MULT			10
1677 #define EXT4_DEF_LI_MAX_START_DELAY		5
1678 #define EXT4_LAZYINIT_QUIT			0x0001
1679 #define EXT4_LAZYINIT_RUNNING			0x0002
1680 
1681 /*
1682  * Lazy inode table initialization info
1683  */
1684 struct ext4_lazy_init {
1685 	unsigned long		li_state;
1686 	struct list_head	li_request_list;
1687 	struct mutex		li_list_mtx;
1688 };
1689 
1690 struct ext4_li_request {
1691 	struct super_block	*lr_super;
1692 	struct ext4_sb_info	*lr_sbi;
1693 	ext4_group_t		lr_next_group;
1694 	struct list_head	lr_request;
1695 	unsigned long		lr_next_sched;
1696 	unsigned long		lr_timeout;
1697 };
1698 
1699 struct ext4_features {
1700 	struct kobject f_kobj;
1701 	struct completion f_kobj_unregister;
1702 };
1703 
1704 /*
1705  * This structure will be used for multiple mount protection. It will be
1706  * written into the block number saved in the s_mmp_block field in the
1707  * superblock. Programs that check MMP should assume that if
1708  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1709  * to use the filesystem, regardless of how old the timestamp is.
1710  */
1711 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1712 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1713 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1714 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1715 
1716 struct mmp_struct {
1717 	__le32	mmp_magic;		/* Magic number for MMP */
1718 	__le32	mmp_seq;		/* Sequence no. updated periodically */
1719 
1720 	/*
1721 	 * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1722 	 * purposes and do not affect the correctness of the algorithm
1723 	 */
1724 	__le64	mmp_time;		/* Time last updated */
1725 	char	mmp_nodename[64];	/* Node which last updated MMP block */
1726 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
1727 
1728 	/*
1729 	 * mmp_check_interval is used to verify if the MMP block has been
1730 	 * updated on the block device. The value is updated based on the
1731 	 * maximum time to write the MMP block during an update cycle.
1732 	 */
1733 	__le16	mmp_check_interval;
1734 
1735 	__le16	mmp_pad1;
1736 	__le32	mmp_pad2[227];
1737 };
1738 
1739 /* arguments passed to the mmp thread */
1740 struct mmpd_data {
1741 	struct buffer_head *bh; /* bh from initial read_mmp_block() */
1742 	struct super_block *sb;  /* super block of the fs */
1743 };
1744 
1745 /*
1746  * Check interval multiplier
1747  * The MMP block is written every update interval and initially checked every
1748  * update interval x the multiplier (the value is then adapted based on the
1749  * write latency). The reason is that writes can be delayed under load and we
1750  * don't want readers to incorrectly assume that the filesystem is no longer
1751  * in use.
1752  */
1753 #define EXT4_MMP_CHECK_MULT		2UL
1754 
1755 /*
1756  * Minimum interval for MMP checking in seconds.
1757  */
1758 #define EXT4_MMP_MIN_CHECK_INTERVAL	5UL
1759 
1760 /*
1761  * Maximum interval for MMP checking in seconds.
1762  */
1763 #define EXT4_MMP_MAX_CHECK_INTERVAL	300UL
1764 
1765 /*
1766  * Function prototypes
1767  */
1768 
1769 /*
1770  * Ok, these declarations are also in <linux/kernel.h> but none of the
1771  * ext4 source programs needs to include it so they are duplicated here.
1772  */
1773 # define NORET_TYPE	/**/
1774 # define ATTRIB_NORET	__attribute__((noreturn))
1775 # define NORET_AND	noreturn,
1776 
1777 /* bitmap.c */
1778 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
1779 
1780 /* balloc.c */
1781 extern unsigned int ext4_block_group(struct super_block *sb,
1782 			ext4_fsblk_t blocknr);
1783 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1784 			ext4_fsblk_t blocknr);
1785 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1786 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1787 			ext4_group_t group);
1788 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1789 					 ext4_fsblk_t goal,
1790 					 unsigned int flags,
1791 					 unsigned long *count,
1792 					 int *errp);
1793 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1794 				    s64 nclusters, unsigned int flags);
1795 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1796 extern void ext4_check_blocks_bitmap(struct super_block *);
1797 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1798 						    ext4_group_t block_group,
1799 						    struct buffer_head ** bh);
1800 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1801 
1802 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1803 						ext4_group_t block_group);
1804 extern int ext4_wait_block_bitmap(struct super_block *sb,
1805 				  ext4_group_t block_group,
1806 				  struct buffer_head *bh);
1807 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1808 						  ext4_group_t block_group);
1809 extern void ext4_init_block_bitmap(struct super_block *sb,
1810 				   struct buffer_head *bh,
1811 				   ext4_group_t group,
1812 				   struct ext4_group_desc *desc);
1813 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1814 					      ext4_group_t block_group,
1815 					      struct ext4_group_desc *gdp);
1816 extern unsigned ext4_num_overhead_clusters(struct super_block *sb,
1817 					   ext4_group_t block_group,
1818 					   struct ext4_group_desc *gdp);
1819 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1820 
1821 /* dir.c */
1822 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1823 				  struct file *,
1824 				  struct ext4_dir_entry_2 *,
1825 				  struct buffer_head *, unsigned int);
1826 #define ext4_check_dir_entry(dir, filp, de, bh, offset)			\
1827 	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1828 					(de), (bh), (offset)))
1829 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1830 				    __u32 minor_hash,
1831 				    struct ext4_dir_entry_2 *dirent);
1832 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1833 
1834 /* fsync.c */
1835 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
1836 extern int ext4_flush_completed_IO(struct inode *);
1837 
1838 /* hash.c */
1839 extern int ext4fs_dirhash(const char *name, int len, struct
1840 			  dx_hash_info *hinfo);
1841 
1842 /* ialloc.c */
1843 extern struct inode *ext4_new_inode(handle_t *, struct inode *, umode_t,
1844 				    const struct qstr *qstr, __u32 goal,
1845 				    uid_t *owner);
1846 extern void ext4_free_inode(handle_t *, struct inode *);
1847 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1848 extern unsigned long ext4_count_free_inodes(struct super_block *);
1849 extern unsigned long ext4_count_dirs(struct super_block *);
1850 extern void ext4_check_inodes_bitmap(struct super_block *);
1851 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1852 extern int ext4_init_inode_table(struct super_block *sb,
1853 				 ext4_group_t group, int barrier);
1854 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
1855 
1856 /* mballoc.c */
1857 extern long ext4_mb_stats;
1858 extern long ext4_mb_max_to_scan;
1859 extern int ext4_mb_init(struct super_block *, int);
1860 extern int ext4_mb_release(struct super_block *);
1861 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1862 				struct ext4_allocation_request *, int *);
1863 extern int ext4_mb_reserve_blocks(struct super_block *, int);
1864 extern void ext4_discard_preallocations(struct inode *);
1865 extern int __init ext4_init_mballoc(void);
1866 extern void ext4_exit_mballoc(void);
1867 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1868 			     struct buffer_head *bh, ext4_fsblk_t block,
1869 			     unsigned long count, int flags);
1870 extern int ext4_mb_add_groupinfo(struct super_block *sb,
1871 		ext4_group_t i, struct ext4_group_desc *desc);
1872 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
1873 				ext4_fsblk_t block, unsigned long count);
1874 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
1875 
1876 /* inode.c */
1877 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1878 						ext4_lblk_t, int, int *);
1879 struct buffer_head *ext4_bread(handle_t *, struct inode *,
1880 						ext4_lblk_t, int, int *);
1881 int ext4_get_block(struct inode *inode, sector_t iblock,
1882 				struct buffer_head *bh_result, int create);
1883 
1884 extern struct inode *ext4_iget(struct super_block *, unsigned long);
1885 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
1886 extern int  ext4_setattr(struct dentry *, struct iattr *);
1887 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1888 				struct kstat *stat);
1889 extern void ext4_evict_inode(struct inode *);
1890 extern void ext4_clear_inode(struct inode *);
1891 extern int  ext4_sync_inode(handle_t *, struct inode *);
1892 extern void ext4_dirty_inode(struct inode *, int);
1893 extern int ext4_change_inode_journal_flag(struct inode *, int);
1894 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1895 extern int ext4_can_truncate(struct inode *inode);
1896 extern void ext4_truncate(struct inode *);
1897 extern int ext4_punch_hole(struct file *file, loff_t offset, loff_t length);
1898 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
1899 extern void ext4_set_inode_flags(struct inode *);
1900 extern void ext4_get_inode_flags(struct ext4_inode_info *);
1901 extern int ext4_alloc_da_blocks(struct inode *inode);
1902 extern void ext4_set_aops(struct inode *inode);
1903 extern int ext4_writepage_trans_blocks(struct inode *);
1904 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1905 extern int ext4_discard_partial_page_buffers(handle_t *handle,
1906 		struct address_space *mapping, loff_t from,
1907 		loff_t length, int flags);
1908 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1909 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
1910 extern void ext4_da_update_reserve_space(struct inode *inode,
1911 					int used, int quota_claim);
1912 
1913 /* indirect.c */
1914 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
1915 				struct ext4_map_blocks *map, int flags);
1916 extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
1917 				const struct iovec *iov, loff_t offset,
1918 				unsigned long nr_segs);
1919 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
1920 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk);
1921 extern void ext4_ind_truncate(struct inode *inode);
1922 
1923 /* ioctl.c */
1924 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1925 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1926 
1927 /* migrate.c */
1928 extern int ext4_ext_migrate(struct inode *);
1929 
1930 /* namei.c */
1931 extern int ext4_orphan_add(handle_t *, struct inode *);
1932 extern int ext4_orphan_del(handle_t *, struct inode *);
1933 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1934 				__u32 start_minor_hash, __u32 *next_hash);
1935 
1936 /* resize.c */
1937 extern int ext4_group_add(struct super_block *sb,
1938 				struct ext4_new_group_data *input);
1939 extern int ext4_group_extend(struct super_block *sb,
1940 				struct ext4_super_block *es,
1941 				ext4_fsblk_t n_blocks_count);
1942 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
1943 
1944 /* super.c */
1945 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
1946 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
1947 extern void ext4_kvfree(void *ptr);
1948 extern __printf(4, 5)
1949 void __ext4_error(struct super_block *, const char *, unsigned int,
1950 		  const char *, ...);
1951 #define ext4_error(sb, message...)	__ext4_error(sb, __func__,	\
1952 						     __LINE__, ## message)
1953 extern __printf(5, 6)
1954 void ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
1955 		      const char *, ...);
1956 extern __printf(5, 6)
1957 void ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
1958 		     const char *, ...);
1959 extern void __ext4_std_error(struct super_block *, const char *,
1960 			     unsigned int, int);
1961 extern __printf(4, 5)
1962 void __ext4_abort(struct super_block *, const char *, unsigned int,
1963 		  const char *, ...);
1964 #define ext4_abort(sb, message...)	__ext4_abort(sb, __func__, \
1965 						       __LINE__, ## message)
1966 extern __printf(4, 5)
1967 void __ext4_warning(struct super_block *, const char *, unsigned int,
1968 		    const char *, ...);
1969 #define ext4_warning(sb, message...)	__ext4_warning(sb, __func__, \
1970 						       __LINE__, ## message)
1971 extern __printf(3, 4)
1972 void ext4_msg(struct super_block *, const char *, const char *, ...);
1973 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
1974 			   const char *, unsigned int, const char *);
1975 #define dump_mmp_msg(sb, mmp, msg)	__dump_mmp_msg(sb, mmp, __func__, \
1976 						       __LINE__, msg)
1977 extern __printf(7, 8)
1978 void __ext4_grp_locked_error(const char *, unsigned int,
1979 			     struct super_block *, ext4_group_t,
1980 			     unsigned long, ext4_fsblk_t,
1981 			     const char *, ...);
1982 #define ext4_grp_locked_error(sb, grp, message...) \
1983 	__ext4_grp_locked_error(__func__, __LINE__, (sb), (grp), ## message)
1984 extern void ext4_update_dynamic_rev(struct super_block *sb);
1985 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1986 					__u32 compat);
1987 extern int ext4_update_rocompat_feature(handle_t *handle,
1988 					struct super_block *sb,	__u32 rocompat);
1989 extern int ext4_update_incompat_feature(handle_t *handle,
1990 					struct super_block *sb,	__u32 incompat);
1991 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1992 				      struct ext4_group_desc *bg);
1993 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1994 				      struct ext4_group_desc *bg);
1995 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1996 				     struct ext4_group_desc *bg);
1997 extern __u32 ext4_free_group_clusters(struct super_block *sb,
1998 				      struct ext4_group_desc *bg);
1999 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2000 				 struct ext4_group_desc *bg);
2001 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2002 				struct ext4_group_desc *bg);
2003 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2004 				   struct ext4_group_desc *bg);
2005 extern void ext4_block_bitmap_set(struct super_block *sb,
2006 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2007 extern void ext4_inode_bitmap_set(struct super_block *sb,
2008 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2009 extern void ext4_inode_table_set(struct super_block *sb,
2010 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
2011 extern void ext4_free_group_clusters_set(struct super_block *sb,
2012 					 struct ext4_group_desc *bg,
2013 					 __u32 count);
2014 extern void ext4_free_inodes_set(struct super_block *sb,
2015 				struct ext4_group_desc *bg, __u32 count);
2016 extern void ext4_used_dirs_set(struct super_block *sb,
2017 				struct ext4_group_desc *bg, __u32 count);
2018 extern void ext4_itable_unused_set(struct super_block *sb,
2019 				   struct ext4_group_desc *bg, __u32 count);
2020 extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
2021 				   struct ext4_group_desc *gdp);
2022 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
2023 				       struct ext4_group_desc *gdp);
2024 
2025 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2026 {
2027 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2028 		le32_to_cpu(es->s_blocks_count_lo);
2029 }
2030 
2031 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2032 {
2033 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2034 		le32_to_cpu(es->s_r_blocks_count_lo);
2035 }
2036 
2037 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2038 {
2039 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2040 		le32_to_cpu(es->s_free_blocks_count_lo);
2041 }
2042 
2043 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2044 					 ext4_fsblk_t blk)
2045 {
2046 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2047 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2048 }
2049 
2050 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2051 					      ext4_fsblk_t blk)
2052 {
2053 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2054 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2055 }
2056 
2057 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2058 					   ext4_fsblk_t blk)
2059 {
2060 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2061 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2062 }
2063 
2064 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2065 {
2066 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2067 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2068 			le32_to_cpu(raw_inode->i_size_lo);
2069 	else
2070 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2071 }
2072 
2073 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2074 {
2075 	raw_inode->i_size_lo = cpu_to_le32(i_size);
2076 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2077 }
2078 
2079 static inline
2080 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2081 					    ext4_group_t group)
2082 {
2083 	 struct ext4_group_info ***grp_info;
2084 	 long indexv, indexh;
2085 	 grp_info = EXT4_SB(sb)->s_group_info;
2086 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2087 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2088 	 return grp_info[indexv][indexh];
2089 }
2090 
2091 /*
2092  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2093  * the locking protocol documented in the comments of ext4_group_add()
2094  * in resize.c
2095  */
2096 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2097 {
2098 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
2099 
2100 	smp_rmb();
2101 	return ngroups;
2102 }
2103 
2104 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2105 					     ext4_group_t block_group)
2106 {
2107 	return block_group >> sbi->s_log_groups_per_flex;
2108 }
2109 
2110 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2111 {
2112 	return 1 << sbi->s_log_groups_per_flex;
2113 }
2114 
2115 #define ext4_std_error(sb, errno)				\
2116 do {								\
2117 	if ((errno))						\
2118 		__ext4_std_error((sb), __func__, __LINE__, (errno));	\
2119 } while (0)
2120 
2121 #ifdef CONFIG_SMP
2122 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2123  * counters. So we need to make sure we have free clusters more
2124  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2125  */
2126 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2127 #else
2128 #define EXT4_FREECLUSTERS_WATERMARK 0
2129 #endif
2130 
2131 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2132 {
2133 	/*
2134 	 * XXX: replace with spinlock if seen contended -bzzz
2135 	 */
2136 	down_write(&EXT4_I(inode)->i_data_sem);
2137 	if (newsize > EXT4_I(inode)->i_disksize)
2138 		EXT4_I(inode)->i_disksize = newsize;
2139 	up_write(&EXT4_I(inode)->i_data_sem);
2140 	return ;
2141 }
2142 
2143 struct ext4_group_info {
2144 	unsigned long   bb_state;
2145 	struct rb_root  bb_free_root;
2146 	ext4_grpblk_t	bb_first_free;	/* first free block */
2147 	ext4_grpblk_t	bb_free;	/* total free blocks */
2148 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
2149 	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
2150 	struct          list_head bb_prealloc_list;
2151 #ifdef DOUBLE_CHECK
2152 	void            *bb_bitmap;
2153 #endif
2154 	struct rw_semaphore alloc_sem;
2155 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
2156 					 * regions, index is order.
2157 					 * bb_counters[3] = 5 means
2158 					 * 5 free 8-block regions. */
2159 };
2160 
2161 #define EXT4_GROUP_INFO_NEED_INIT_BIT		0
2162 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT		1
2163 
2164 #define EXT4_MB_GRP_NEED_INIT(grp)	\
2165 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2166 
2167 #define EXT4_MB_GRP_WAS_TRIMMED(grp)	\
2168 	(test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2169 #define EXT4_MB_GRP_SET_TRIMMED(grp)	\
2170 	(set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2171 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)	\
2172 	(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2173 
2174 #define EXT4_MAX_CONTENTION		8
2175 #define EXT4_CONTENTION_THRESHOLD	2
2176 
2177 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2178 					      ext4_group_t group)
2179 {
2180 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2181 }
2182 
2183 /*
2184  * Returns true if the filesystem is busy enough that attempts to
2185  * access the block group locks has run into contention.
2186  */
2187 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2188 {
2189 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2190 }
2191 
2192 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2193 {
2194 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2195 	if (spin_trylock(lock))
2196 		/*
2197 		 * We're able to grab the lock right away, so drop the
2198 		 * lock contention counter.
2199 		 */
2200 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2201 	else {
2202 		/*
2203 		 * The lock is busy, so bump the contention counter,
2204 		 * and then wait on the spin lock.
2205 		 */
2206 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2207 				  EXT4_MAX_CONTENTION);
2208 		spin_lock(lock);
2209 	}
2210 }
2211 
2212 static inline void ext4_unlock_group(struct super_block *sb,
2213 					ext4_group_t group)
2214 {
2215 	spin_unlock(ext4_group_lock_ptr(sb, group));
2216 }
2217 
2218 static inline void ext4_mark_super_dirty(struct super_block *sb)
2219 {
2220 	if (EXT4_SB(sb)->s_journal == NULL)
2221 		sb->s_dirt =1;
2222 }
2223 
2224 /*
2225  * Block validity checking
2226  */
2227 #define ext4_check_indirect_blockref(inode, bh)				\
2228 	ext4_check_blockref(__func__, __LINE__, inode,			\
2229 			    (__le32 *)(bh)->b_data,			\
2230 			    EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2231 
2232 #define ext4_ind_check_inode(inode)					\
2233 	ext4_check_blockref(__func__, __LINE__, inode,			\
2234 			    EXT4_I(inode)->i_data,			\
2235 			    EXT4_NDIR_BLOCKS)
2236 
2237 /*
2238  * Inodes and files operations
2239  */
2240 
2241 /* dir.c */
2242 extern const struct file_operations ext4_dir_operations;
2243 
2244 /* file.c */
2245 extern const struct inode_operations ext4_file_inode_operations;
2246 extern const struct file_operations ext4_file_operations;
2247 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2248 
2249 /* namei.c */
2250 extern const struct inode_operations ext4_dir_inode_operations;
2251 extern const struct inode_operations ext4_special_inode_operations;
2252 extern struct dentry *ext4_get_parent(struct dentry *child);
2253 
2254 /* symlink.c */
2255 extern const struct inode_operations ext4_symlink_inode_operations;
2256 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2257 
2258 /* block_validity */
2259 extern void ext4_release_system_zone(struct super_block *sb);
2260 extern int ext4_setup_system_zone(struct super_block *sb);
2261 extern int __init ext4_init_system_zone(void);
2262 extern void ext4_exit_system_zone(void);
2263 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2264 				 ext4_fsblk_t start_blk,
2265 				 unsigned int count);
2266 extern int ext4_check_blockref(const char *, unsigned int,
2267 			       struct inode *, __le32 *, unsigned int);
2268 
2269 /* extents.c */
2270 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2271 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2272 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
2273 				       int chunk);
2274 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2275 			       struct ext4_map_blocks *map, int flags);
2276 extern void ext4_ext_truncate(struct inode *);
2277 extern int ext4_ext_punch_hole(struct file *file, loff_t offset,
2278 				loff_t length);
2279 extern void ext4_ext_init(struct super_block *);
2280 extern void ext4_ext_release(struct super_block *);
2281 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2282 			  loff_t len);
2283 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
2284 			  ssize_t len);
2285 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2286 			   struct ext4_map_blocks *map, int flags);
2287 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2288 			__u64 start, __u64 len);
2289 /* move_extent.c */
2290 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2291 			     __u64 start_orig, __u64 start_donor,
2292 			     __u64 len, __u64 *moved_len);
2293 
2294 /* page-io.c */
2295 extern int __init ext4_init_pageio(void);
2296 extern void ext4_exit_pageio(void);
2297 extern void ext4_ioend_wait(struct inode *);
2298 extern void ext4_free_io_end(ext4_io_end_t *io);
2299 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2300 extern int ext4_end_io_nolock(ext4_io_end_t *io);
2301 extern void ext4_io_submit(struct ext4_io_submit *io);
2302 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2303 			       struct page *page,
2304 			       int len,
2305 			       struct writeback_control *wbc);
2306 
2307 /* mmp.c */
2308 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2309 
2310 /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
2311 enum ext4_state_bits {
2312 	BH_Uninit	/* blocks are allocated but uninitialized on disk */
2313 	  = BH_JBDPrivateStart,
2314 	BH_AllocFromCluster,	/* allocated blocks were part of already
2315 				 * allocated cluster. Note that this flag will
2316 				 * never, ever appear in a buffer_head's state
2317 				 * flag. See EXT4_MAP_FROM_CLUSTER to see where
2318 				 * this is used. */
2319 	BH_Da_Mapped,	/* Delayed allocated block that now has a mapping. This
2320 			 * flag is set when ext4_map_blocks is called on a
2321 			 * delayed allocated block to get its real mapping. */
2322 };
2323 
2324 BUFFER_FNS(Uninit, uninit)
2325 TAS_BUFFER_FNS(Uninit, uninit)
2326 BUFFER_FNS(Da_Mapped, da_mapped)
2327 
2328 /*
2329  * Add new method to test wether block and inode bitmaps are properly
2330  * initialized. With uninit_bg reading the block from disk is not enough
2331  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2332  */
2333 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2334 
2335 static inline int bitmap_uptodate(struct buffer_head *bh)
2336 {
2337 	return (buffer_uptodate(bh) &&
2338 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2339 }
2340 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2341 {
2342 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2343 }
2344 
2345 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
2346 
2347 /* For ioend & aio unwritten conversion wait queues */
2348 #define EXT4_WQ_HASH_SZ		37
2349 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2350 					    EXT4_WQ_HASH_SZ])
2351 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2352 					     EXT4_WQ_HASH_SZ])
2353 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2354 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2355 
2356 #define EXT4_RESIZING	0
2357 extern int ext4_resize_begin(struct super_block *sb);
2358 extern void ext4_resize_end(struct super_block *sb);
2359 
2360 #endif	/* __KERNEL__ */
2361 
2362 #include "ext4_extents.h"
2363 
2364 #endif	/* _EXT4_H */
2365