xref: /openbmc/linux/fs/ext4/ext4.h (revision 5a916be1)
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 
189 struct ext4_io_page {
190 	struct page	*p_page;
191 	atomic_t	p_count;
192 };
193 
194 #define MAX_IO_PAGES 128
195 
196 typedef struct ext4_io_end {
197 	struct list_head	list;		/* per-file finished IO list */
198 	struct inode		*inode;		/* file being written to */
199 	unsigned int		flag;		/* unwritten or not */
200 	struct page		*page;		/* page struct for buffer write */
201 	loff_t			offset;		/* offset in the file */
202 	ssize_t			size;		/* size of the extent */
203 	struct work_struct	work;		/* data work queue */
204 	struct kiocb		*iocb;		/* iocb struct for AIO */
205 	int			result;		/* error value for AIO */
206 	int			num_io_pages;
207 	struct ext4_io_page	*pages[MAX_IO_PAGES];
208 } ext4_io_end_t;
209 
210 struct ext4_io_submit {
211 	int			io_op;
212 	struct bio		*io_bio;
213 	ext4_io_end_t		*io_end;
214 	struct ext4_io_page	*io_page;
215 	sector_t		io_next_block;
216 };
217 
218 /*
219  * Special inodes numbers
220  */
221 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
222 #define EXT4_ROOT_INO		 2	/* Root inode */
223 #define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
224 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
225 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
226 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
227 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
228 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
229 
230 /* First non-reserved inode for old ext4 filesystems */
231 #define EXT4_GOOD_OLD_FIRST_INO	11
232 
233 /*
234  * Maximal count of links to a file
235  */
236 #define EXT4_LINK_MAX		65000
237 
238 /*
239  * Macro-instructions used to manage several block sizes
240  */
241 #define EXT4_MIN_BLOCK_SIZE		1024
242 #define	EXT4_MAX_BLOCK_SIZE		65536
243 #define EXT4_MIN_BLOCK_LOG_SIZE		10
244 #define EXT4_MAX_BLOCK_LOG_SIZE		16
245 #ifdef __KERNEL__
246 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
247 #else
248 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
249 #endif
250 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
251 #define EXT4_CLUSTER_SIZE(s)		(EXT4_BLOCK_SIZE(s) << \
252 					 EXT4_SB(s)->s_cluster_bits)
253 #ifdef __KERNEL__
254 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
255 # define EXT4_CLUSTER_BITS(s)		(EXT4_SB(s)->s_cluster_bits)
256 #else
257 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
258 #endif
259 #ifdef __KERNEL__
260 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
261 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
262 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
263 #else
264 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
265 				 EXT4_GOOD_OLD_INODE_SIZE : \
266 				 (s)->s_inode_size)
267 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
268 				 EXT4_GOOD_OLD_FIRST_INO : \
269 				 (s)->s_first_ino)
270 #endif
271 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
272 
273 /* Translate a block number to a cluster number */
274 #define EXT4_B2C(sbi, blk)	((blk) >> (sbi)->s_cluster_bits)
275 /* Translate a cluster number to a block number */
276 #define EXT4_C2B(sbi, cluster)	((cluster) << (sbi)->s_cluster_bits)
277 /* Translate # of blks to # of clusters */
278 #define EXT4_NUM_B2C(sbi, blks)	(((blks) + (sbi)->s_cluster_ratio - 1) >> \
279 				 (sbi)->s_cluster_bits)
280 
281 /*
282  * Structure of a blocks group descriptor
283  */
284 struct ext4_group_desc
285 {
286 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
287 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
288 	__le32	bg_inode_table_lo;	/* Inodes table block */
289 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
290 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
291 	__le16	bg_used_dirs_count_lo;	/* Directories count */
292 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
293 	__u32	bg_reserved[2];		/* Likely block/inode bitmap checksum */
294 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
295 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
296 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
297 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
298 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
299 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
300 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
301 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
302 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
303 	__u32	bg_reserved2[3];
304 };
305 
306 /*
307  * Structure of a flex block group info
308  */
309 
310 struct flex_groups {
311 	atomic_t free_inodes;
312 	atomic_t free_clusters;
313 	atomic_t used_dirs;
314 };
315 
316 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
317 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
318 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
319 
320 /*
321  * Macro-instructions used to manage group descriptors
322  */
323 #define EXT4_MIN_DESC_SIZE		32
324 #define EXT4_MIN_DESC_SIZE_64BIT	64
325 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
326 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
327 #ifdef __KERNEL__
328 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
329 # define EXT4_CLUSTERS_PER_GROUP(s)	(EXT4_SB(s)->s_clusters_per_group)
330 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
331 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
332 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
333 #else
334 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
335 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
336 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
337 #endif
338 
339 /*
340  * Constants relative to the data blocks
341  */
342 #define	EXT4_NDIR_BLOCKS		12
343 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
344 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
345 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
346 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
347 
348 /*
349  * Inode flags
350  */
351 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
352 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
353 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
354 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
355 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
356 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
357 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
358 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
359 /* Reserved for compression usage... */
360 #define EXT4_DIRTY_FL			0x00000100
361 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
362 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
363 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
364 /* End compression flags --- maybe not all used */
365 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
366 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
367 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
368 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
369 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
370 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
371 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
372 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
373 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
374 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
375 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
376 
377 #define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
378 #define EXT4_FL_USER_MODIFIABLE		0x004B80FF /* User modifiable flags */
379 
380 /* Flags that should be inherited by new inodes from their parent. */
381 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
382 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
383 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
384 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
385 
386 /* Flags that are appropriate for regular files (all but dir-specific ones). */
387 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
388 
389 /* Flags that are appropriate for non-directories/regular files. */
390 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
391 
392 /* Mask out flags that are inappropriate for the given type of inode. */
393 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
394 {
395 	if (S_ISDIR(mode))
396 		return flags;
397 	else if (S_ISREG(mode))
398 		return flags & EXT4_REG_FLMASK;
399 	else
400 		return flags & EXT4_OTHER_FLMASK;
401 }
402 
403 /*
404  * Inode flags used for atomic set/get
405  */
406 enum {
407 	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
408 	EXT4_INODE_UNRM		= 1,	/* Undelete */
409 	EXT4_INODE_COMPR	= 2,	/* Compress file */
410 	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
411 	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
412 	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
413 	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
414 	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
415 /* Reserved for compression usage... */
416 	EXT4_INODE_DIRTY	= 8,
417 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
418 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
419 	EXT4_INODE_ECOMPR	= 11,	/* Compression error */
420 /* End compression flags --- maybe not all used */
421 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
422 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
423 	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
424 	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
425 	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
426 	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
427 	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
428 	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
429 	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
430 	EXT4_INODE_EOFBLOCKS	= 22,	/* Blocks allocated beyond EOF */
431 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
432 };
433 
434 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
435 #define CHECK_FLAG_VALUE(FLAG) if (!TEST_FLAG_VALUE(FLAG)) { \
436 	printk(KERN_EMERG "EXT4 flag fail: " #FLAG ": %d %d\n", \
437 		EXT4_##FLAG##_FL, EXT4_INODE_##FLAG); BUG_ON(1); }
438 
439 /*
440  * Since it's pretty easy to mix up bit numbers and hex values, and we
441  * can't do a compile-time test for ENUM values, we use a run-time
442  * test to make sure that EXT4_XXX_FL is consistent with respect to
443  * EXT4_INODE_XXX.  If all is well the printk and BUG_ON will all drop
444  * out so it won't cost any extra space in the compiled kernel image.
445  * But it's important that these values are the same, since we are
446  * using EXT4_INODE_XXX to test for the flag values, but EXT4_XX_FL
447  * must be consistent with the values of FS_XXX_FL defined in
448  * include/linux/fs.h and the on-disk values found in ext2, ext3, and
449  * ext4 filesystems, and of course the values defined in e2fsprogs.
450  *
451  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
452  */
453 static inline void ext4_check_flag_values(void)
454 {
455 	CHECK_FLAG_VALUE(SECRM);
456 	CHECK_FLAG_VALUE(UNRM);
457 	CHECK_FLAG_VALUE(COMPR);
458 	CHECK_FLAG_VALUE(SYNC);
459 	CHECK_FLAG_VALUE(IMMUTABLE);
460 	CHECK_FLAG_VALUE(APPEND);
461 	CHECK_FLAG_VALUE(NODUMP);
462 	CHECK_FLAG_VALUE(NOATIME);
463 	CHECK_FLAG_VALUE(DIRTY);
464 	CHECK_FLAG_VALUE(COMPRBLK);
465 	CHECK_FLAG_VALUE(NOCOMPR);
466 	CHECK_FLAG_VALUE(ECOMPR);
467 	CHECK_FLAG_VALUE(INDEX);
468 	CHECK_FLAG_VALUE(IMAGIC);
469 	CHECK_FLAG_VALUE(JOURNAL_DATA);
470 	CHECK_FLAG_VALUE(NOTAIL);
471 	CHECK_FLAG_VALUE(DIRSYNC);
472 	CHECK_FLAG_VALUE(TOPDIR);
473 	CHECK_FLAG_VALUE(HUGE_FILE);
474 	CHECK_FLAG_VALUE(EXTENTS);
475 	CHECK_FLAG_VALUE(EA_INODE);
476 	CHECK_FLAG_VALUE(EOFBLOCKS);
477 	CHECK_FLAG_VALUE(RESERVED);
478 }
479 
480 /* Used to pass group descriptor data when online resize is done */
481 struct ext4_new_group_input {
482 	__u32 group;		/* Group number for this data */
483 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
484 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
485 	__u64 inode_table;	/* Absolute block number of inode table start */
486 	__u32 blocks_count;	/* Total number of blocks in this group */
487 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
488 	__u16 unused;
489 };
490 
491 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
492 struct compat_ext4_new_group_input {
493 	u32 group;
494 	compat_u64 block_bitmap;
495 	compat_u64 inode_bitmap;
496 	compat_u64 inode_table;
497 	u32 blocks_count;
498 	u16 reserved_blocks;
499 	u16 unused;
500 };
501 #endif
502 
503 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
504 struct ext4_new_group_data {
505 	__u32 group;
506 	__u64 block_bitmap;
507 	__u64 inode_bitmap;
508 	__u64 inode_table;
509 	__u32 blocks_count;
510 	__u16 reserved_blocks;
511 	__u16 unused;
512 	__u32 free_blocks_count;
513 };
514 
515 /* Indexes used to index group tables in ext4_new_group_data */
516 enum {
517 	BLOCK_BITMAP = 0,	/* block bitmap */
518 	INODE_BITMAP,		/* inode bitmap */
519 	INODE_TABLE,		/* inode tables */
520 	GROUP_TABLE_COUNT,
521 };
522 
523 /*
524  * Flags used by ext4_map_blocks()
525  */
526 	/* Allocate any needed blocks and/or convert an unitialized
527 	   extent to be an initialized ext4 */
528 #define EXT4_GET_BLOCKS_CREATE			0x0001
529 	/* Request the creation of an unitialized extent */
530 #define EXT4_GET_BLOCKS_UNINIT_EXT		0x0002
531 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\
532 						 EXT4_GET_BLOCKS_CREATE)
533 	/* Caller is from the delayed allocation writeout path,
534 	   so set the magic i_delalloc_reserve_flag after taking the
535 	   inode allocation semaphore for */
536 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
537 	/* caller is from the direct IO path, request to creation of an
538 	unitialized extents if not allocated, split the uninitialized
539 	extent if blocks has been preallocated already*/
540 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
541 #define EXT4_GET_BLOCKS_CONVERT			0x0010
542 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
543 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
544 	/* Convert extent to initialized after IO complete */
545 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
546 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
547 	/* Punch out blocks of an extent */
548 #define EXT4_GET_BLOCKS_PUNCH_OUT_EXT		0x0020
549 	/* Don't normalize allocation size (used for fallocate) */
550 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
551 	/* Request will not result in inode size update (user for fallocate) */
552 #define EXT4_GET_BLOCKS_KEEP_SIZE		0x0080
553 
554 /*
555  * Flags used by ext4_free_blocks
556  */
557 #define EXT4_FREE_BLOCKS_METADATA	0x0001
558 #define EXT4_FREE_BLOCKS_FORGET		0x0002
559 #define EXT4_FREE_BLOCKS_VALIDATED	0x0004
560 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE	0x0008
561 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
562 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
563 
564 /*
565  * Flags used by ext4_discard_partial_page_buffers
566  */
567 #define EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED	0x0001
568 
569 /*
570  * ioctl commands
571  */
572 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
573 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
574 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
575 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
576 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
577 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
578 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
579 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
580 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
581 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
582 #define EXT4_IOC_MIGRATE		_IO('f', 9)
583  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
584  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
585 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
586 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
587 #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
588 
589 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
590 /*
591  * ioctl commands in 32 bit emulation
592  */
593 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
594 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
595 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
596 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
597 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
598 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
599 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
600 #define EXT4_IOC32_GROUP_ADD		_IOW('f', 8, struct compat_ext4_new_group_input)
601 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
602 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
603 #endif
604 
605 /* Max physical block we can address w/o extents */
606 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
607 
608 /*
609  * Structure of an inode on the disk
610  */
611 struct ext4_inode {
612 	__le16	i_mode;		/* File mode */
613 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
614 	__le32	i_size_lo;	/* Size in bytes */
615 	__le32	i_atime;	/* Access time */
616 	__le32	i_ctime;	/* Inode Change time */
617 	__le32	i_mtime;	/* Modification time */
618 	__le32	i_dtime;	/* Deletion Time */
619 	__le16	i_gid;		/* Low 16 bits of Group Id */
620 	__le16	i_links_count;	/* Links count */
621 	__le32	i_blocks_lo;	/* Blocks count */
622 	__le32	i_flags;	/* File flags */
623 	union {
624 		struct {
625 			__le32  l_i_version;
626 		} linux1;
627 		struct {
628 			__u32  h_i_translator;
629 		} hurd1;
630 		struct {
631 			__u32  m_i_reserved1;
632 		} masix1;
633 	} osd1;				/* OS dependent 1 */
634 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
635 	__le32	i_generation;	/* File version (for NFS) */
636 	__le32	i_file_acl_lo;	/* File ACL */
637 	__le32	i_size_high;
638 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
639 	union {
640 		struct {
641 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
642 			__le16	l_i_file_acl_high;
643 			__le16	l_i_uid_high;	/* these 2 fields */
644 			__le16	l_i_gid_high;	/* were reserved2[0] */
645 			__u32	l_i_reserved2;
646 		} linux2;
647 		struct {
648 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
649 			__u16	h_i_mode_high;
650 			__u16	h_i_uid_high;
651 			__u16	h_i_gid_high;
652 			__u32	h_i_author;
653 		} hurd2;
654 		struct {
655 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
656 			__le16	m_i_file_acl_high;
657 			__u32	m_i_reserved2[2];
658 		} masix2;
659 	} osd2;				/* OS dependent 2 */
660 	__le16	i_extra_isize;
661 	__le16	i_pad1;
662 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
663 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
664 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
665 	__le32  i_crtime;       /* File Creation time */
666 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
667 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
668 };
669 
670 struct move_extent {
671 	__u32 reserved;		/* should be zero */
672 	__u32 donor_fd;		/* donor file descriptor */
673 	__u64 orig_start;	/* logical start offset in block for orig */
674 	__u64 donor_start;	/* logical start offset in block for donor */
675 	__u64 len;		/* block length to be moved */
676 	__u64 moved_len;	/* moved block length */
677 };
678 
679 #define EXT4_EPOCH_BITS 2
680 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
681 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
682 
683 /*
684  * Extended fields will fit into an inode if the filesystem was formatted
685  * with large inodes (-I 256 or larger) and there are not currently any EAs
686  * consuming all of the available space. For new inodes we always reserve
687  * enough space for the kernel's known extended fields, but for inodes
688  * created with an old kernel this might not have been the case. None of
689  * the extended inode fields is critical for correct filesystem operation.
690  * This macro checks if a certain field fits in the inode. Note that
691  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
692  */
693 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
694 	((offsetof(typeof(*ext4_inode), field) +	\
695 	  sizeof((ext4_inode)->field))			\
696 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
697 	    (einode)->i_extra_isize))			\
698 
699 static inline __le32 ext4_encode_extra_time(struct timespec *time)
700 {
701        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
702 			   (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
703                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
704 }
705 
706 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
707 {
708        if (sizeof(time->tv_sec) > 4)
709 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
710 			       << 32;
711        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
712 }
713 
714 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
715 do {									       \
716 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
717 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
718 		(raw_inode)->xtime ## _extra =				       \
719 				ext4_encode_extra_time(&(inode)->xtime);       \
720 } while (0)
721 
722 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
723 do {									       \
724 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
725 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
726 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
727 		(raw_inode)->xtime ## _extra =				       \
728 				ext4_encode_extra_time(&(einode)->xtime);      \
729 } while (0)
730 
731 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
732 do {									       \
733 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
734 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
735 		ext4_decode_extra_time(&(inode)->xtime,			       \
736 				       raw_inode->xtime ## _extra);	       \
737 	else								       \
738 		(inode)->xtime.tv_nsec = 0;				       \
739 } while (0)
740 
741 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
742 do {									       \
743 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
744 		(einode)->xtime.tv_sec = 				       \
745 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
746 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
747 		ext4_decode_extra_time(&(einode)->xtime,		       \
748 				       raw_inode->xtime ## _extra);	       \
749 	else								       \
750 		(einode)->xtime.tv_nsec = 0;				       \
751 } while (0)
752 
753 #define i_disk_version osd1.linux1.l_i_version
754 
755 #if defined(__KERNEL__) || defined(__linux__)
756 #define i_reserved1	osd1.linux1.l_i_reserved1
757 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
758 #define i_blocks_high	osd2.linux2.l_i_blocks_high
759 #define i_uid_low	i_uid
760 #define i_gid_low	i_gid
761 #define i_uid_high	osd2.linux2.l_i_uid_high
762 #define i_gid_high	osd2.linux2.l_i_gid_high
763 #define i_reserved2	osd2.linux2.l_i_reserved2
764 
765 #elif defined(__GNU__)
766 
767 #define i_translator	osd1.hurd1.h_i_translator
768 #define i_uid_high	osd2.hurd2.h_i_uid_high
769 #define i_gid_high	osd2.hurd2.h_i_gid_high
770 #define i_author	osd2.hurd2.h_i_author
771 
772 #elif defined(__masix__)
773 
774 #define i_reserved1	osd1.masix1.m_i_reserved1
775 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
776 #define i_reserved2	osd2.masix2.m_i_reserved2
777 
778 #endif /* defined(__KERNEL__) || defined(__linux__) */
779 
780 /*
781  * storage for cached extent
782  * If ec_len == 0, then the cache is invalid.
783  * If ec_start == 0, then the cache represents a gap (null mapping)
784  */
785 struct ext4_ext_cache {
786 	ext4_fsblk_t	ec_start;
787 	ext4_lblk_t	ec_block;
788 	__u32		ec_len; /* must be 32bit to return holes */
789 };
790 
791 /*
792  * fourth extended file system inode data in memory
793  */
794 struct ext4_inode_info {
795 	__le32	i_data[15];	/* unconverted */
796 	__u32	i_dtime;
797 	ext4_fsblk_t	i_file_acl;
798 
799 	/*
800 	 * i_block_group is the number of the block group which contains
801 	 * this file's inode.  Constant across the lifetime of the inode,
802 	 * it is ued for making block allocation decisions - we try to
803 	 * place a file's data blocks near its inode block, and new inodes
804 	 * near to their parent directory's inode.
805 	 */
806 	ext4_group_t	i_block_group;
807 	ext4_lblk_t	i_dir_start_lookup;
808 #if (BITS_PER_LONG < 64)
809 	unsigned long	i_state_flags;		/* Dynamic state flags */
810 #endif
811 	unsigned long	i_flags;
812 
813 #ifdef CONFIG_EXT4_FS_XATTR
814 	/*
815 	 * Extended attributes can be read independently of the main file
816 	 * data. Taking i_mutex even when reading would cause contention
817 	 * between readers of EAs and writers of regular file data, so
818 	 * instead we synchronize on xattr_sem when reading or changing
819 	 * EAs.
820 	 */
821 	struct rw_semaphore xattr_sem;
822 #endif
823 
824 	struct list_head i_orphan;	/* unlinked but open inodes */
825 
826 	/*
827 	 * i_disksize keeps track of what the inode size is ON DISK, not
828 	 * in memory.  During truncate, i_size is set to the new size by
829 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
830 	 * set i_disksize to 0 until the truncate is actually under way.
831 	 *
832 	 * The intent is that i_disksize always represents the blocks which
833 	 * are used by this file.  This allows recovery to restart truncate
834 	 * on orphans if we crash during truncate.  We actually write i_disksize
835 	 * into the on-disk inode when writing inodes out, instead of i_size.
836 	 *
837 	 * The only time when i_disksize and i_size may be different is when
838 	 * a truncate is in progress.  The only things which change i_disksize
839 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
840 	 */
841 	loff_t	i_disksize;
842 
843 	/*
844 	 * i_data_sem is for serialising ext4_truncate() against
845 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
846 	 * data tree are chopped off during truncate. We can't do that in
847 	 * ext4 because whenever we perform intermediate commits during
848 	 * truncate, the inode and all the metadata blocks *must* be in a
849 	 * consistent state which allows truncation of the orphans to restart
850 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
851 	 * by other means, so we have i_data_sem.
852 	 */
853 	struct rw_semaphore i_data_sem;
854 	struct inode vfs_inode;
855 	struct jbd2_inode *jinode;
856 
857 	struct ext4_ext_cache i_cached_extent;
858 	/*
859 	 * File creation time. Its function is same as that of
860 	 * struct timespec i_{a,c,m}time in the generic inode.
861 	 */
862 	struct timespec i_crtime;
863 
864 	/* mballoc */
865 	struct list_head i_prealloc_list;
866 	spinlock_t i_prealloc_lock;
867 
868 	/* ialloc */
869 	ext4_group_t	i_last_alloc_group;
870 
871 	/* allocation reservation info for delalloc */
872 	/* In case of bigalloc, these refer to clusters rather than blocks */
873 	unsigned int i_reserved_data_blocks;
874 	unsigned int i_reserved_meta_blocks;
875 	unsigned int i_allocated_meta_blocks;
876 	ext4_lblk_t i_da_metadata_calc_last_lblock;
877 	int i_da_metadata_calc_len;
878 
879 	/* on-disk additional length */
880 	__u16 i_extra_isize;
881 
882 #ifdef CONFIG_QUOTA
883 	/* quota space reservation, managed internally by quota code */
884 	qsize_t i_reserved_quota;
885 #endif
886 
887 	/* completed IOs that might need unwritten extents handling */
888 	struct list_head i_completed_io_list;
889 	spinlock_t i_completed_io_lock;
890 	atomic_t i_ioend_count;	/* Number of outstanding io_end structs */
891 	/* current io_end structure for async DIO write*/
892 	ext4_io_end_t *cur_aio_dio;
893 	atomic_t i_aiodio_unwritten; /* Nr. of inflight conversions pending */
894 
895 	spinlock_t i_block_reservation_lock;
896 
897 	/*
898 	 * Transactions that contain inode's metadata needed to complete
899 	 * fsync and fdatasync, respectively.
900 	 */
901 	tid_t i_sync_tid;
902 	tid_t i_datasync_tid;
903 };
904 
905 /*
906  * File system states
907  */
908 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
909 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
910 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
911 
912 /*
913  * Misc. filesystem flags
914  */
915 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
916 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
917 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
918 
919 /*
920  * Mount flags
921  */
922 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
923 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
924 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
925 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
926 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
927 #define EXT4_MOUNT_ERRORS_MASK		0x00070
928 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
929 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
930 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
931 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
932 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
933 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
934 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
935 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
936 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
937 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
938 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
939 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
940 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
941 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
942 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
943 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
944 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
945 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
946 #define EXT4_MOUNT_MBLK_IO_SUBMIT	0x4000000 /* multi-block io submits */
947 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
948 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
949 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
950 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
951 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
952 
953 #define EXT4_MOUNT2_EXPLICIT_DELALLOC	0x00000001 /* User explicitly
954 						      specified delalloc */
955 
956 #define clear_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt &= \
957 						~EXT4_MOUNT_##opt
958 #define set_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt |= \
959 						EXT4_MOUNT_##opt
960 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
961 					 EXT4_MOUNT_##opt)
962 
963 #define clear_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 &= \
964 						~EXT4_MOUNT2_##opt
965 #define set_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 |= \
966 						EXT4_MOUNT2_##opt
967 #define test_opt2(sb, opt)		(EXT4_SB(sb)->s_mount_opt2 & \
968 					 EXT4_MOUNT2_##opt)
969 
970 #define ext4_test_and_set_bit		__test_and_set_bit_le
971 #define ext4_set_bit			__set_bit_le
972 #define ext4_set_bit_atomic		ext2_set_bit_atomic
973 #define ext4_test_and_clear_bit		__test_and_clear_bit_le
974 #define ext4_clear_bit			__clear_bit_le
975 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
976 #define ext4_test_bit			test_bit_le
977 #define ext4_find_next_zero_bit		find_next_zero_bit_le
978 #define ext4_find_next_bit		find_next_bit_le
979 
980 extern void ext4_set_bits(void *bm, int cur, int len);
981 
982 /*
983  * Maximal mount counts between two filesystem checks
984  */
985 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
986 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
987 
988 /*
989  * Behaviour when detecting errors
990  */
991 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
992 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
993 #define EXT4_ERRORS_PANIC		3	/* Panic */
994 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
995 
996 /*
997  * Structure of the super block
998  */
999 struct ext4_super_block {
1000 /*00*/	__le32	s_inodes_count;		/* Inodes count */
1001 	__le32	s_blocks_count_lo;	/* Blocks count */
1002 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
1003 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
1004 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
1005 	__le32	s_first_data_block;	/* First Data Block */
1006 	__le32	s_log_block_size;	/* Block size */
1007 	__le32	s_log_cluster_size;	/* Allocation cluster size */
1008 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
1009 	__le32	s_clusters_per_group;	/* # Clusters per group */
1010 	__le32	s_inodes_per_group;	/* # Inodes per group */
1011 	__le32	s_mtime;		/* Mount time */
1012 /*30*/	__le32	s_wtime;		/* Write time */
1013 	__le16	s_mnt_count;		/* Mount count */
1014 	__le16	s_max_mnt_count;	/* Maximal mount count */
1015 	__le16	s_magic;		/* Magic signature */
1016 	__le16	s_state;		/* File system state */
1017 	__le16	s_errors;		/* Behaviour when detecting errors */
1018 	__le16	s_minor_rev_level;	/* minor revision level */
1019 /*40*/	__le32	s_lastcheck;		/* time of last check */
1020 	__le32	s_checkinterval;	/* max. time between checks */
1021 	__le32	s_creator_os;		/* OS */
1022 	__le32	s_rev_level;		/* Revision level */
1023 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
1024 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
1025 	/*
1026 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
1027 	 *
1028 	 * Note: the difference between the compatible feature set and
1029 	 * the incompatible feature set is that if there is a bit set
1030 	 * in the incompatible feature set that the kernel doesn't
1031 	 * know about, it should refuse to mount the filesystem.
1032 	 *
1033 	 * e2fsck's requirements are more strict; if it doesn't know
1034 	 * about a feature in either the compatible or incompatible
1035 	 * feature set, it must abort and not try to meddle with
1036 	 * things it doesn't understand...
1037 	 */
1038 	__le32	s_first_ino;		/* First non-reserved inode */
1039 	__le16  s_inode_size;		/* size of inode structure */
1040 	__le16	s_block_group_nr;	/* block group # of this superblock */
1041 	__le32	s_feature_compat;	/* compatible feature set */
1042 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
1043 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
1044 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
1045 /*78*/	char	s_volume_name[16];	/* volume name */
1046 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
1047 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
1048 	/*
1049 	 * Performance hints.  Directory preallocation should only
1050 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1051 	 */
1052 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
1053 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
1054 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
1055 	/*
1056 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1057 	 */
1058 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
1059 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
1060 	__le32	s_journal_dev;		/* device number of journal file */
1061 	__le32	s_last_orphan;		/* start of list of inodes to delete */
1062 	__le32	s_hash_seed[4];		/* HTREE hash seed */
1063 	__u8	s_def_hash_version;	/* Default hash version to use */
1064 	__u8	s_jnl_backup_type;
1065 	__le16  s_desc_size;		/* size of group descriptor */
1066 /*100*/	__le32	s_default_mount_opts;
1067 	__le32	s_first_meta_bg;	/* First metablock block group */
1068 	__le32	s_mkfs_time;		/* When the filesystem was created */
1069 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
1070 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1071 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
1072 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
1073 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
1074 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
1075 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
1076 	__le32	s_flags;		/* Miscellaneous flags */
1077 	__le16  s_raid_stride;		/* RAID stride */
1078 	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1079 	__le64  s_mmp_block;            /* Block for multi-mount protection */
1080 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1081 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
1082 	__u8	s_reserved_char_pad;
1083 	__le16  s_reserved_pad;
1084 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1085 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
1086 	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
1087 	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
1088 					      snapshot's future use */
1089 	__le32	s_snapshot_list;	/* inode number of the head of the
1090 					   on-disk snapshot list */
1091 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1092 	__le32	s_error_count;		/* number of fs errors */
1093 	__le32	s_first_error_time;	/* first time an error happened */
1094 	__le32	s_first_error_ino;	/* inode involved in first error */
1095 	__le64	s_first_error_block;	/* block involved of first error */
1096 	__u8	s_first_error_func[32];	/* function where the error happened */
1097 	__le32	s_first_error_line;	/* line number where error happened */
1098 	__le32	s_last_error_time;	/* most recent time of an error */
1099 	__le32	s_last_error_ino;	/* inode involved in last error */
1100 	__le32	s_last_error_line;	/* line number where error happened */
1101 	__le64	s_last_error_block;	/* block involved of last error */
1102 	__u8	s_last_error_func[32];	/* function where the error happened */
1103 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1104 	__u8	s_mount_opts[64];
1105 	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
1106 	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
1107 	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
1108 	__le32  s_reserved[109];        /* Padding to the end of the block */
1109 };
1110 
1111 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1112 
1113 #ifdef __KERNEL__
1114 
1115 /*
1116  * run-time mount flags
1117  */
1118 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
1119 #define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
1120 
1121 /*
1122  * fourth extended-fs super-block data in memory
1123  */
1124 struct ext4_sb_info {
1125 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
1126 	unsigned long s_inodes_per_block;/* Number of inodes per block */
1127 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
1128 	unsigned long s_clusters_per_group; /* Number of clusters in a group */
1129 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
1130 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
1131 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
1132 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
1133 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1134 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1135 	unsigned long s_overhead_last;  /* Last calculated overhead */
1136 	unsigned long s_blocks_last;    /* Last seen block count */
1137 	unsigned int s_cluster_ratio;	/* Number of blocks per cluster */
1138 	unsigned int s_cluster_bits;	/* log2 of s_cluster_ratio */
1139 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
1140 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
1141 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
1142 	struct buffer_head **s_group_desc;
1143 	unsigned int s_mount_opt;
1144 	unsigned int s_mount_opt2;
1145 	unsigned int s_mount_flags;
1146 	unsigned int s_def_mount_opt;
1147 	ext4_fsblk_t s_sb_block;
1148 	uid_t s_resuid;
1149 	gid_t s_resgid;
1150 	unsigned short s_mount_state;
1151 	unsigned short s_pad;
1152 	int s_addr_per_block_bits;
1153 	int s_desc_per_block_bits;
1154 	int s_inode_size;
1155 	int s_first_ino;
1156 	unsigned int s_inode_readahead_blks;
1157 	unsigned int s_inode_goal;
1158 	spinlock_t s_next_gen_lock;
1159 	u32 s_next_generation;
1160 	u32 s_hash_seed[4];
1161 	int s_def_hash_version;
1162 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
1163 	struct percpu_counter s_freeclusters_counter;
1164 	struct percpu_counter s_freeinodes_counter;
1165 	struct percpu_counter s_dirs_counter;
1166 	struct percpu_counter s_dirtyclusters_counter;
1167 	struct blockgroup_lock *s_blockgroup_lock;
1168 	struct proc_dir_entry *s_proc;
1169 	struct kobject s_kobj;
1170 	struct completion s_kobj_unregister;
1171 
1172 	/* Journaling */
1173 	struct journal_s *s_journal;
1174 	struct list_head s_orphan;
1175 	struct mutex s_orphan_lock;
1176 	unsigned long s_resize_flags;		/* Flags indicating if there
1177 						   is a resizer */
1178 	unsigned long s_commit_interval;
1179 	u32 s_max_batch_time;
1180 	u32 s_min_batch_time;
1181 	struct block_device *journal_bdev;
1182 #ifdef CONFIG_QUOTA
1183 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
1184 	int s_jquota_fmt;			/* Format of quota to use */
1185 #endif
1186 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1187 	struct rb_root system_blks;
1188 
1189 #ifdef EXTENTS_STATS
1190 	/* ext4 extents stats */
1191 	unsigned long s_ext_min;
1192 	unsigned long s_ext_max;
1193 	unsigned long s_depth_max;
1194 	spinlock_t s_ext_stats_lock;
1195 	unsigned long s_ext_blocks;
1196 	unsigned long s_ext_extents;
1197 #endif
1198 	/* ext4 extent cache stats */
1199 	unsigned long extent_cache_hits;
1200 	unsigned long extent_cache_misses;
1201 
1202 	/* for buddy allocator */
1203 	struct ext4_group_info ***s_group_info;
1204 	struct inode *s_buddy_cache;
1205 	spinlock_t s_md_lock;
1206 	unsigned short *s_mb_offsets;
1207 	unsigned int *s_mb_maxs;
1208 
1209 	/* tunables */
1210 	unsigned long s_stripe;
1211 	unsigned int s_mb_stream_request;
1212 	unsigned int s_mb_max_to_scan;
1213 	unsigned int s_mb_min_to_scan;
1214 	unsigned int s_mb_stats;
1215 	unsigned int s_mb_order2_reqs;
1216 	unsigned int s_mb_group_prealloc;
1217 	unsigned int s_max_writeback_mb_bump;
1218 	/* where last allocation was done - for stream allocation */
1219 	unsigned long s_mb_last_group;
1220 	unsigned long s_mb_last_start;
1221 
1222 	/* stats for buddy allocator */
1223 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1224 	atomic_t s_bal_success;	/* we found long enough chunks */
1225 	atomic_t s_bal_allocated;	/* in blocks */
1226 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1227 	atomic_t s_bal_goals;	/* goal hits */
1228 	atomic_t s_bal_breaks;	/* too long searches */
1229 	atomic_t s_bal_2orders;	/* 2^order hits */
1230 	spinlock_t s_bal_lock;
1231 	unsigned long s_mb_buddies_generated;
1232 	unsigned long long s_mb_generation_time;
1233 	atomic_t s_mb_lost_chunks;
1234 	atomic_t s_mb_preallocated;
1235 	atomic_t s_mb_discarded;
1236 	atomic_t s_lock_busy;
1237 
1238 	/* locality groups */
1239 	struct ext4_locality_group __percpu *s_locality_groups;
1240 
1241 	/* for write statistics */
1242 	unsigned long s_sectors_written_start;
1243 	u64 s_kbytes_written;
1244 
1245 	unsigned int s_log_groups_per_flex;
1246 	struct flex_groups *s_flex_groups;
1247 
1248 	/* workqueue for dio unwritten */
1249 	struct workqueue_struct *dio_unwritten_wq;
1250 
1251 	/* timer for periodic error stats printing */
1252 	struct timer_list s_err_report;
1253 
1254 	/* Lazy inode table initialization info */
1255 	struct ext4_li_request *s_li_request;
1256 	/* Wait multiplier for lazy initialization thread */
1257 	unsigned int s_li_wait_mult;
1258 
1259 	/* Kernel thread for multiple mount protection */
1260 	struct task_struct *s_mmp_tsk;
1261 
1262 	/* record the last minlen when FITRIM is called. */
1263 	atomic_t s_last_trim_minblks;
1264 };
1265 
1266 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1267 {
1268 	return sb->s_fs_info;
1269 }
1270 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1271 {
1272 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1273 }
1274 
1275 static inline struct timespec ext4_current_time(struct inode *inode)
1276 {
1277 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1278 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1279 }
1280 
1281 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1282 {
1283 	return ino == EXT4_ROOT_INO ||
1284 		ino == EXT4_JOURNAL_INO ||
1285 		ino == EXT4_RESIZE_INO ||
1286 		(ino >= EXT4_FIRST_INO(sb) &&
1287 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1288 }
1289 
1290 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1291 					      struct ext4_io_end *io_end)
1292 {
1293 	if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1294 		io_end->flag |= EXT4_IO_END_UNWRITTEN;
1295 		atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
1296 	}
1297 }
1298 
1299 /*
1300  * Inode dynamic state flags
1301  */
1302 enum {
1303 	EXT4_STATE_JDATA,		/* journaled data exists */
1304 	EXT4_STATE_NEW,			/* inode is newly created */
1305 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1306 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1307 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1308 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1309 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1310 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1311 	EXT4_STATE_DELALLOC_RESERVED,	/* blks already reserved for delalloc */
1312 };
1313 
1314 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
1315 static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
1316 {									\
1317 	return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);	\
1318 }									\
1319 static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
1320 {									\
1321 	set_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1322 }									\
1323 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1324 {									\
1325 	clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1326 }
1327 
1328 EXT4_INODE_BIT_FNS(flag, flags, 0)
1329 #if (BITS_PER_LONG < 64)
1330 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1331 
1332 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1333 {
1334 	(ei)->i_state_flags = 0;
1335 }
1336 #else
1337 EXT4_INODE_BIT_FNS(state, flags, 32)
1338 
1339 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1340 {
1341 	/* We depend on the fact that callers will set i_flags */
1342 }
1343 #endif
1344 #else
1345 /* Assume that user mode programs are passing in an ext4fs superblock, not
1346  * a kernel struct super_block.  This will allow us to call the feature-test
1347  * macros from user land. */
1348 #define EXT4_SB(sb)	(sb)
1349 #endif
1350 
1351 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1352 
1353 /*
1354  * Codes for operating systems
1355  */
1356 #define EXT4_OS_LINUX		0
1357 #define EXT4_OS_HURD		1
1358 #define EXT4_OS_MASIX		2
1359 #define EXT4_OS_FREEBSD		3
1360 #define EXT4_OS_LITES		4
1361 
1362 /*
1363  * Revision levels
1364  */
1365 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1366 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1367 
1368 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1369 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1370 
1371 #define EXT4_GOOD_OLD_INODE_SIZE 128
1372 
1373 /*
1374  * Feature set definitions
1375  */
1376 
1377 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1378 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1379 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1380 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1381 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1382 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1383 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1384 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1385 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1386 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1387 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1388 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1389 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1390 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1391 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1392 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1393 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1394 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1395 
1396 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1397 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1398 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1399 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1400 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1401 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1402 
1403 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1404 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1405 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1406 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1407 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1408 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1409 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1410 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
1411 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
1412 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
1413 
1414 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1415 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1416 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1417 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1418 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1419 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1420 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1421 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1422 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1423 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1424 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1425 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM	0x2000 /* use crc32c for bg */
1426 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
1427 #define EXT4_FEATURE_INCOMPAT_INLINEDATA	0x8000 /* data in inode */
1428 
1429 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1430 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1431 					 EXT4_FEATURE_INCOMPAT_META_BG)
1432 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1433 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1434 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1435 
1436 #define EXT3_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1437 #define EXT3_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1438 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1439 					 EXT4_FEATURE_INCOMPAT_META_BG)
1440 #define EXT3_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1441 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1442 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1443 
1444 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1445 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1446 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1447 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1448 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1449 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1450 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1451 					 EXT4_FEATURE_INCOMPAT_MMP)
1452 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1453 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1454 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1455 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1456 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1457 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1458 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1459 					 EXT4_FEATURE_RO_COMPAT_BIGALLOC)
1460 
1461 /*
1462  * Default values for user and/or group using reserved blocks
1463  */
1464 #define	EXT4_DEF_RESUID		0
1465 #define	EXT4_DEF_RESGID		0
1466 
1467 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1468 
1469 /*
1470  * Default mount options
1471  */
1472 #define EXT4_DEFM_DEBUG		0x0001
1473 #define EXT4_DEFM_BSDGROUPS	0x0002
1474 #define EXT4_DEFM_XATTR_USER	0x0004
1475 #define EXT4_DEFM_ACL		0x0008
1476 #define EXT4_DEFM_UID16		0x0010
1477 #define EXT4_DEFM_JMODE		0x0060
1478 #define EXT4_DEFM_JMODE_DATA	0x0020
1479 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1480 #define EXT4_DEFM_JMODE_WBACK	0x0060
1481 #define EXT4_DEFM_NOBARRIER	0x0100
1482 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1483 #define EXT4_DEFM_DISCARD	0x0400
1484 #define EXT4_DEFM_NODELALLOC	0x0800
1485 
1486 /*
1487  * Default journal batch times
1488  */
1489 #define EXT4_DEF_MIN_BATCH_TIME	0
1490 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1491 
1492 /*
1493  * Minimum number of groups in a flexgroup before we separate out
1494  * directories into the first block group of a flexgroup
1495  */
1496 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1497 
1498 /*
1499  * Structure of a directory entry
1500  */
1501 #define EXT4_NAME_LEN 255
1502 
1503 struct ext4_dir_entry {
1504 	__le32	inode;			/* Inode number */
1505 	__le16	rec_len;		/* Directory entry length */
1506 	__le16	name_len;		/* Name length */
1507 	char	name[EXT4_NAME_LEN];	/* File name */
1508 };
1509 
1510 /*
1511  * The new version of the directory entry.  Since EXT4 structures are
1512  * stored in intel byte order, and the name_len field could never be
1513  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1514  * file_type field.
1515  */
1516 struct ext4_dir_entry_2 {
1517 	__le32	inode;			/* Inode number */
1518 	__le16	rec_len;		/* Directory entry length */
1519 	__u8	name_len;		/* Name length */
1520 	__u8	file_type;
1521 	char	name[EXT4_NAME_LEN];	/* File name */
1522 };
1523 
1524 /*
1525  * Ext4 directory file types.  Only the low 3 bits are used.  The
1526  * other bits are reserved for now.
1527  */
1528 #define EXT4_FT_UNKNOWN		0
1529 #define EXT4_FT_REG_FILE	1
1530 #define EXT4_FT_DIR		2
1531 #define EXT4_FT_CHRDEV		3
1532 #define EXT4_FT_BLKDEV		4
1533 #define EXT4_FT_FIFO		5
1534 #define EXT4_FT_SOCK		6
1535 #define EXT4_FT_SYMLINK		7
1536 
1537 #define EXT4_FT_MAX		8
1538 
1539 /*
1540  * EXT4_DIR_PAD defines the directory entries boundaries
1541  *
1542  * NOTE: It must be a multiple of 4
1543  */
1544 #define EXT4_DIR_PAD			4
1545 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1546 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1547 					 ~EXT4_DIR_ROUND)
1548 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1549 
1550 /*
1551  * If we ever get support for fs block sizes > page_size, we'll need
1552  * to remove the #if statements in the next two functions...
1553  */
1554 static inline unsigned int
1555 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1556 {
1557 	unsigned len = le16_to_cpu(dlen);
1558 
1559 #if (PAGE_CACHE_SIZE >= 65536)
1560 	if (len == EXT4_MAX_REC_LEN || len == 0)
1561 		return blocksize;
1562 	return (len & 65532) | ((len & 3) << 16);
1563 #else
1564 	return len;
1565 #endif
1566 }
1567 
1568 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1569 {
1570 	if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1571 		BUG();
1572 #if (PAGE_CACHE_SIZE >= 65536)
1573 	if (len < 65536)
1574 		return cpu_to_le16(len);
1575 	if (len == blocksize) {
1576 		if (blocksize == 65536)
1577 			return cpu_to_le16(EXT4_MAX_REC_LEN);
1578 		else
1579 			return cpu_to_le16(0);
1580 	}
1581 	return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1582 #else
1583 	return cpu_to_le16(len);
1584 #endif
1585 }
1586 
1587 /*
1588  * Hash Tree Directory indexing
1589  * (c) Daniel Phillips, 2001
1590  */
1591 
1592 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1593 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1594 		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1595 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1596 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1597 
1598 /* Legal values for the dx_root hash_version field: */
1599 
1600 #define DX_HASH_LEGACY		0
1601 #define DX_HASH_HALF_MD4	1
1602 #define DX_HASH_TEA		2
1603 #define DX_HASH_LEGACY_UNSIGNED	3
1604 #define DX_HASH_HALF_MD4_UNSIGNED	4
1605 #define DX_HASH_TEA_UNSIGNED		5
1606 
1607 #ifdef __KERNEL__
1608 
1609 /* hash info structure used by the directory hash */
1610 struct dx_hash_info
1611 {
1612 	u32		hash;
1613 	u32		minor_hash;
1614 	int		hash_version;
1615 	u32		*seed;
1616 };
1617 
1618 #define EXT4_HTREE_EOF	0x7fffffff
1619 
1620 /*
1621  * Control parameters used by ext4_htree_next_block
1622  */
1623 #define HASH_NB_ALWAYS		1
1624 
1625 
1626 /*
1627  * Describe an inode's exact location on disk and in memory
1628  */
1629 struct ext4_iloc
1630 {
1631 	struct buffer_head *bh;
1632 	unsigned long offset;
1633 	ext4_group_t block_group;
1634 };
1635 
1636 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1637 {
1638 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1639 }
1640 
1641 /*
1642  * This structure is stuffed into the struct file's private_data field
1643  * for directories.  It is where we put information so that we can do
1644  * readdir operations in hash tree order.
1645  */
1646 struct dir_private_info {
1647 	struct rb_root	root;
1648 	struct rb_node	*curr_node;
1649 	struct fname	*extra_fname;
1650 	loff_t		last_pos;
1651 	__u32		curr_hash;
1652 	__u32		curr_minor_hash;
1653 	__u32		next_hash;
1654 };
1655 
1656 /* calculate the first block number of the group */
1657 static inline ext4_fsblk_t
1658 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1659 {
1660 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1661 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1662 }
1663 
1664 /*
1665  * Special error return code only used by dx_probe() and its callers.
1666  */
1667 #define ERR_BAD_DX_DIR	-75000
1668 
1669 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1670 			ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1671 
1672 /*
1673  * Timeout and state flag for lazy initialization inode thread.
1674  */
1675 #define EXT4_DEF_LI_WAIT_MULT			10
1676 #define EXT4_DEF_LI_MAX_START_DELAY		5
1677 #define EXT4_LAZYINIT_QUIT			0x0001
1678 #define EXT4_LAZYINIT_RUNNING			0x0002
1679 
1680 /*
1681  * Lazy inode table initialization info
1682  */
1683 struct ext4_lazy_init {
1684 	unsigned long		li_state;
1685 	struct list_head	li_request_list;
1686 	struct mutex		li_list_mtx;
1687 };
1688 
1689 struct ext4_li_request {
1690 	struct super_block	*lr_super;
1691 	struct ext4_sb_info	*lr_sbi;
1692 	ext4_group_t		lr_next_group;
1693 	struct list_head	lr_request;
1694 	unsigned long		lr_next_sched;
1695 	unsigned long		lr_timeout;
1696 };
1697 
1698 struct ext4_features {
1699 	struct kobject f_kobj;
1700 	struct completion f_kobj_unregister;
1701 };
1702 
1703 /*
1704  * This structure will be used for multiple mount protection. It will be
1705  * written into the block number saved in the s_mmp_block field in the
1706  * superblock. Programs that check MMP should assume that if
1707  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1708  * to use the filesystem, regardless of how old the timestamp is.
1709  */
1710 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1711 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1712 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1713 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1714 
1715 struct mmp_struct {
1716 	__le32	mmp_magic;		/* Magic number for MMP */
1717 	__le32	mmp_seq;		/* Sequence no. updated periodically */
1718 
1719 	/*
1720 	 * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1721 	 * purposes and do not affect the correctness of the algorithm
1722 	 */
1723 	__le64	mmp_time;		/* Time last updated */
1724 	char	mmp_nodename[64];	/* Node which last updated MMP block */
1725 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
1726 
1727 	/*
1728 	 * mmp_check_interval is used to verify if the MMP block has been
1729 	 * updated on the block device. The value is updated based on the
1730 	 * maximum time to write the MMP block during an update cycle.
1731 	 */
1732 	__le16	mmp_check_interval;
1733 
1734 	__le16	mmp_pad1;
1735 	__le32	mmp_pad2[227];
1736 };
1737 
1738 /* arguments passed to the mmp thread */
1739 struct mmpd_data {
1740 	struct buffer_head *bh; /* bh from initial read_mmp_block() */
1741 	struct super_block *sb;  /* super block of the fs */
1742 };
1743 
1744 /*
1745  * Check interval multiplier
1746  * The MMP block is written every update interval and initially checked every
1747  * update interval x the multiplier (the value is then adapted based on the
1748  * write latency). The reason is that writes can be delayed under load and we
1749  * don't want readers to incorrectly assume that the filesystem is no longer
1750  * in use.
1751  */
1752 #define EXT4_MMP_CHECK_MULT		2UL
1753 
1754 /*
1755  * Minimum interval for MMP checking in seconds.
1756  */
1757 #define EXT4_MMP_MIN_CHECK_INTERVAL	5UL
1758 
1759 /*
1760  * Maximum interval for MMP checking in seconds.
1761  */
1762 #define EXT4_MMP_MAX_CHECK_INTERVAL	300UL
1763 
1764 /*
1765  * Function prototypes
1766  */
1767 
1768 /*
1769  * Ok, these declarations are also in <linux/kernel.h> but none of the
1770  * ext4 source programs needs to include it so they are duplicated here.
1771  */
1772 # define NORET_TYPE	/**/
1773 # define ATTRIB_NORET	__attribute__((noreturn))
1774 # define NORET_AND	noreturn,
1775 
1776 /* bitmap.c */
1777 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
1778 
1779 /* balloc.c */
1780 extern unsigned int ext4_block_group(struct super_block *sb,
1781 			ext4_fsblk_t blocknr);
1782 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1783 			ext4_fsblk_t blocknr);
1784 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1785 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1786 			ext4_group_t group);
1787 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1788 					 ext4_fsblk_t goal,
1789 					 unsigned int flags,
1790 					 unsigned long *count,
1791 					 int *errp);
1792 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1793 				    s64 nclusters, unsigned int flags);
1794 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1795 extern void ext4_check_blocks_bitmap(struct super_block *);
1796 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1797 						    ext4_group_t block_group,
1798 						    struct buffer_head ** bh);
1799 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1800 
1801 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1802 						ext4_group_t block_group);
1803 extern int ext4_wait_block_bitmap(struct super_block *sb,
1804 				  ext4_group_t block_group,
1805 				  struct buffer_head *bh);
1806 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1807 						  ext4_group_t block_group);
1808 extern void ext4_init_block_bitmap(struct super_block *sb,
1809 				   struct buffer_head *bh,
1810 				   ext4_group_t group,
1811 				   struct ext4_group_desc *desc);
1812 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1813 					      ext4_group_t block_group,
1814 					      struct ext4_group_desc *gdp);
1815 extern unsigned ext4_num_overhead_clusters(struct super_block *sb,
1816 					   ext4_group_t block_group,
1817 					   struct ext4_group_desc *gdp);
1818 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1819 
1820 /* dir.c */
1821 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1822 				  struct file *,
1823 				  struct ext4_dir_entry_2 *,
1824 				  struct buffer_head *, unsigned int);
1825 #define ext4_check_dir_entry(dir, filp, de, bh, offset)			\
1826 	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1827 					(de), (bh), (offset)))
1828 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1829 				    __u32 minor_hash,
1830 				    struct ext4_dir_entry_2 *dirent);
1831 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1832 
1833 /* fsync.c */
1834 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
1835 extern int ext4_flush_completed_IO(struct inode *);
1836 
1837 /* hash.c */
1838 extern int ext4fs_dirhash(const char *name, int len, struct
1839 			  dx_hash_info *hinfo);
1840 
1841 /* ialloc.c */
1842 extern struct inode *ext4_new_inode(handle_t *, struct inode *, umode_t,
1843 				    const struct qstr *qstr, __u32 goal,
1844 				    uid_t *owner);
1845 extern void ext4_free_inode(handle_t *, struct inode *);
1846 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1847 extern unsigned long ext4_count_free_inodes(struct super_block *);
1848 extern unsigned long ext4_count_dirs(struct super_block *);
1849 extern void ext4_check_inodes_bitmap(struct super_block *);
1850 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1851 extern int ext4_init_inode_table(struct super_block *sb,
1852 				 ext4_group_t group, int barrier);
1853 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
1854 
1855 /* mballoc.c */
1856 extern long ext4_mb_stats;
1857 extern long ext4_mb_max_to_scan;
1858 extern int ext4_mb_init(struct super_block *, int);
1859 extern int ext4_mb_release(struct super_block *);
1860 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1861 				struct ext4_allocation_request *, int *);
1862 extern int ext4_mb_reserve_blocks(struct super_block *, int);
1863 extern void ext4_discard_preallocations(struct inode *);
1864 extern int __init ext4_init_mballoc(void);
1865 extern void ext4_exit_mballoc(void);
1866 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1867 			     struct buffer_head *bh, ext4_fsblk_t block,
1868 			     unsigned long count, int flags);
1869 extern int ext4_mb_add_groupinfo(struct super_block *sb,
1870 		ext4_group_t i, struct ext4_group_desc *desc);
1871 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
1872 				ext4_fsblk_t block, unsigned long count);
1873 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
1874 
1875 /* inode.c */
1876 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1877 						ext4_lblk_t, int, int *);
1878 struct buffer_head *ext4_bread(handle_t *, struct inode *,
1879 						ext4_lblk_t, int, int *);
1880 int ext4_get_block(struct inode *inode, sector_t iblock,
1881 				struct buffer_head *bh_result, int create);
1882 
1883 extern struct inode *ext4_iget(struct super_block *, unsigned long);
1884 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
1885 extern int  ext4_setattr(struct dentry *, struct iattr *);
1886 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1887 				struct kstat *stat);
1888 extern void ext4_evict_inode(struct inode *);
1889 extern void ext4_clear_inode(struct inode *);
1890 extern int  ext4_sync_inode(handle_t *, struct inode *);
1891 extern void ext4_dirty_inode(struct inode *, int);
1892 extern int ext4_change_inode_journal_flag(struct inode *, int);
1893 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1894 extern int ext4_can_truncate(struct inode *inode);
1895 extern void ext4_truncate(struct inode *);
1896 extern int ext4_punch_hole(struct file *file, loff_t offset, loff_t length);
1897 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
1898 extern void ext4_set_inode_flags(struct inode *);
1899 extern void ext4_get_inode_flags(struct ext4_inode_info *);
1900 extern int ext4_alloc_da_blocks(struct inode *inode);
1901 extern void ext4_set_aops(struct inode *inode);
1902 extern int ext4_writepage_trans_blocks(struct inode *);
1903 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1904 extern int ext4_discard_partial_page_buffers(handle_t *handle,
1905 		struct address_space *mapping, loff_t from,
1906 		loff_t length, int flags);
1907 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1908 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
1909 extern void ext4_da_update_reserve_space(struct inode *inode,
1910 					int used, int quota_claim);
1911 
1912 /* indirect.c */
1913 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
1914 				struct ext4_map_blocks *map, int flags);
1915 extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
1916 				const struct iovec *iov, loff_t offset,
1917 				unsigned long nr_segs);
1918 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
1919 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk);
1920 extern void ext4_ind_truncate(struct inode *inode);
1921 
1922 /* ioctl.c */
1923 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1924 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1925 
1926 /* migrate.c */
1927 extern int ext4_ext_migrate(struct inode *);
1928 
1929 /* namei.c */
1930 extern int ext4_orphan_add(handle_t *, struct inode *);
1931 extern int ext4_orphan_del(handle_t *, struct inode *);
1932 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1933 				__u32 start_minor_hash, __u32 *next_hash);
1934 
1935 /* resize.c */
1936 extern int ext4_group_add(struct super_block *sb,
1937 				struct ext4_new_group_data *input);
1938 extern int ext4_group_extend(struct super_block *sb,
1939 				struct ext4_super_block *es,
1940 				ext4_fsblk_t n_blocks_count);
1941 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
1942 
1943 /* super.c */
1944 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
1945 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
1946 extern void ext4_kvfree(void *ptr);
1947 extern __printf(4, 5)
1948 void __ext4_error(struct super_block *, const char *, unsigned int,
1949 		  const char *, ...);
1950 #define ext4_error(sb, message...)	__ext4_error(sb, __func__,	\
1951 						     __LINE__, ## message)
1952 extern __printf(5, 6)
1953 void ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
1954 		      const char *, ...);
1955 extern __printf(5, 6)
1956 void ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
1957 		     const char *, ...);
1958 extern void __ext4_std_error(struct super_block *, const char *,
1959 			     unsigned int, int);
1960 extern __printf(4, 5)
1961 void __ext4_abort(struct super_block *, const char *, unsigned int,
1962 		  const char *, ...);
1963 #define ext4_abort(sb, message...)	__ext4_abort(sb, __func__, \
1964 						       __LINE__, ## message)
1965 extern __printf(4, 5)
1966 void __ext4_warning(struct super_block *, const char *, unsigned int,
1967 		    const char *, ...);
1968 #define ext4_warning(sb, message...)	__ext4_warning(sb, __func__, \
1969 						       __LINE__, ## message)
1970 extern __printf(3, 4)
1971 void ext4_msg(struct super_block *, const char *, const char *, ...);
1972 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
1973 			   const char *, unsigned int, const char *);
1974 #define dump_mmp_msg(sb, mmp, msg)	__dump_mmp_msg(sb, mmp, __func__, \
1975 						       __LINE__, msg)
1976 extern __printf(7, 8)
1977 void __ext4_grp_locked_error(const char *, unsigned int,
1978 			     struct super_block *, ext4_group_t,
1979 			     unsigned long, ext4_fsblk_t,
1980 			     const char *, ...);
1981 #define ext4_grp_locked_error(sb, grp, message...) \
1982 	__ext4_grp_locked_error(__func__, __LINE__, (sb), (grp), ## message)
1983 extern void ext4_update_dynamic_rev(struct super_block *sb);
1984 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1985 					__u32 compat);
1986 extern int ext4_update_rocompat_feature(handle_t *handle,
1987 					struct super_block *sb,	__u32 rocompat);
1988 extern int ext4_update_incompat_feature(handle_t *handle,
1989 					struct super_block *sb,	__u32 incompat);
1990 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1991 				      struct ext4_group_desc *bg);
1992 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1993 				      struct ext4_group_desc *bg);
1994 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1995 				     struct ext4_group_desc *bg);
1996 extern __u32 ext4_free_group_clusters(struct super_block *sb,
1997 				      struct ext4_group_desc *bg);
1998 extern __u32 ext4_free_inodes_count(struct super_block *sb,
1999 				 struct ext4_group_desc *bg);
2000 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2001 				struct ext4_group_desc *bg);
2002 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2003 				   struct ext4_group_desc *bg);
2004 extern void ext4_block_bitmap_set(struct super_block *sb,
2005 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2006 extern void ext4_inode_bitmap_set(struct super_block *sb,
2007 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2008 extern void ext4_inode_table_set(struct super_block *sb,
2009 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
2010 extern void ext4_free_group_clusters_set(struct super_block *sb,
2011 					 struct ext4_group_desc *bg,
2012 					 __u32 count);
2013 extern void ext4_free_inodes_set(struct super_block *sb,
2014 				struct ext4_group_desc *bg, __u32 count);
2015 extern void ext4_used_dirs_set(struct super_block *sb,
2016 				struct ext4_group_desc *bg, __u32 count);
2017 extern void ext4_itable_unused_set(struct super_block *sb,
2018 				   struct ext4_group_desc *bg, __u32 count);
2019 extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
2020 				   struct ext4_group_desc *gdp);
2021 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
2022 				       struct ext4_group_desc *gdp);
2023 
2024 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2025 {
2026 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2027 		le32_to_cpu(es->s_blocks_count_lo);
2028 }
2029 
2030 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2031 {
2032 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2033 		le32_to_cpu(es->s_r_blocks_count_lo);
2034 }
2035 
2036 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2037 {
2038 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2039 		le32_to_cpu(es->s_free_blocks_count_lo);
2040 }
2041 
2042 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2043 					 ext4_fsblk_t blk)
2044 {
2045 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2046 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2047 }
2048 
2049 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2050 					      ext4_fsblk_t blk)
2051 {
2052 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2053 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2054 }
2055 
2056 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2057 					   ext4_fsblk_t blk)
2058 {
2059 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2060 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2061 }
2062 
2063 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2064 {
2065 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2066 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2067 			le32_to_cpu(raw_inode->i_size_lo);
2068 	else
2069 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2070 }
2071 
2072 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2073 {
2074 	raw_inode->i_size_lo = cpu_to_le32(i_size);
2075 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2076 }
2077 
2078 static inline
2079 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2080 					    ext4_group_t group)
2081 {
2082 	 struct ext4_group_info ***grp_info;
2083 	 long indexv, indexh;
2084 	 grp_info = EXT4_SB(sb)->s_group_info;
2085 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2086 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2087 	 return grp_info[indexv][indexh];
2088 }
2089 
2090 /*
2091  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2092  * the locking protocol documented in the comments of ext4_group_add()
2093  * in resize.c
2094  */
2095 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2096 {
2097 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
2098 
2099 	smp_rmb();
2100 	return ngroups;
2101 }
2102 
2103 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2104 					     ext4_group_t block_group)
2105 {
2106 	return block_group >> sbi->s_log_groups_per_flex;
2107 }
2108 
2109 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2110 {
2111 	return 1 << sbi->s_log_groups_per_flex;
2112 }
2113 
2114 #define ext4_std_error(sb, errno)				\
2115 do {								\
2116 	if ((errno))						\
2117 		__ext4_std_error((sb), __func__, __LINE__, (errno));	\
2118 } while (0)
2119 
2120 #ifdef CONFIG_SMP
2121 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2122  * counters. So we need to make sure we have free clusters more
2123  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2124  */
2125 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2126 #else
2127 #define EXT4_FREECLUSTERS_WATERMARK 0
2128 #endif
2129 
2130 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2131 {
2132 	/*
2133 	 * XXX: replace with spinlock if seen contended -bzzz
2134 	 */
2135 	down_write(&EXT4_I(inode)->i_data_sem);
2136 	if (newsize > EXT4_I(inode)->i_disksize)
2137 		EXT4_I(inode)->i_disksize = newsize;
2138 	up_write(&EXT4_I(inode)->i_data_sem);
2139 	return ;
2140 }
2141 
2142 struct ext4_group_info {
2143 	unsigned long   bb_state;
2144 	struct rb_root  bb_free_root;
2145 	ext4_grpblk_t	bb_first_free;	/* first free block */
2146 	ext4_grpblk_t	bb_free;	/* total free blocks */
2147 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
2148 	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
2149 	struct          list_head bb_prealloc_list;
2150 #ifdef DOUBLE_CHECK
2151 	void            *bb_bitmap;
2152 #endif
2153 	struct rw_semaphore alloc_sem;
2154 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
2155 					 * regions, index is order.
2156 					 * bb_counters[3] = 5 means
2157 					 * 5 free 8-block regions. */
2158 };
2159 
2160 #define EXT4_GROUP_INFO_NEED_INIT_BIT		0
2161 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT		1
2162 
2163 #define EXT4_MB_GRP_NEED_INIT(grp)	\
2164 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2165 
2166 #define EXT4_MB_GRP_WAS_TRIMMED(grp)	\
2167 	(test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2168 #define EXT4_MB_GRP_SET_TRIMMED(grp)	\
2169 	(set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2170 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)	\
2171 	(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2172 
2173 #define EXT4_MAX_CONTENTION		8
2174 #define EXT4_CONTENTION_THRESHOLD	2
2175 
2176 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2177 					      ext4_group_t group)
2178 {
2179 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2180 }
2181 
2182 /*
2183  * Returns true if the filesystem is busy enough that attempts to
2184  * access the block group locks has run into contention.
2185  */
2186 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2187 {
2188 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2189 }
2190 
2191 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2192 {
2193 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2194 	if (spin_trylock(lock))
2195 		/*
2196 		 * We're able to grab the lock right away, so drop the
2197 		 * lock contention counter.
2198 		 */
2199 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2200 	else {
2201 		/*
2202 		 * The lock is busy, so bump the contention counter,
2203 		 * and then wait on the spin lock.
2204 		 */
2205 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2206 				  EXT4_MAX_CONTENTION);
2207 		spin_lock(lock);
2208 	}
2209 }
2210 
2211 static inline void ext4_unlock_group(struct super_block *sb,
2212 					ext4_group_t group)
2213 {
2214 	spin_unlock(ext4_group_lock_ptr(sb, group));
2215 }
2216 
2217 static inline void ext4_mark_super_dirty(struct super_block *sb)
2218 {
2219 	if (EXT4_SB(sb)->s_journal == NULL)
2220 		sb->s_dirt =1;
2221 }
2222 
2223 /*
2224  * Block validity checking
2225  */
2226 #define ext4_check_indirect_blockref(inode, bh)				\
2227 	ext4_check_blockref(__func__, __LINE__, inode,			\
2228 			    (__le32 *)(bh)->b_data,			\
2229 			    EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2230 
2231 #define ext4_ind_check_inode(inode)					\
2232 	ext4_check_blockref(__func__, __LINE__, inode,			\
2233 			    EXT4_I(inode)->i_data,			\
2234 			    EXT4_NDIR_BLOCKS)
2235 
2236 /*
2237  * Inodes and files operations
2238  */
2239 
2240 /* dir.c */
2241 extern const struct file_operations ext4_dir_operations;
2242 
2243 /* file.c */
2244 extern const struct inode_operations ext4_file_inode_operations;
2245 extern const struct file_operations ext4_file_operations;
2246 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2247 
2248 /* namei.c */
2249 extern const struct inode_operations ext4_dir_inode_operations;
2250 extern const struct inode_operations ext4_special_inode_operations;
2251 extern struct dentry *ext4_get_parent(struct dentry *child);
2252 
2253 /* symlink.c */
2254 extern const struct inode_operations ext4_symlink_inode_operations;
2255 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2256 
2257 /* block_validity */
2258 extern void ext4_release_system_zone(struct super_block *sb);
2259 extern int ext4_setup_system_zone(struct super_block *sb);
2260 extern int __init ext4_init_system_zone(void);
2261 extern void ext4_exit_system_zone(void);
2262 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2263 				 ext4_fsblk_t start_blk,
2264 				 unsigned int count);
2265 extern int ext4_check_blockref(const char *, unsigned int,
2266 			       struct inode *, __le32 *, unsigned int);
2267 
2268 /* extents.c */
2269 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2270 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2271 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
2272 				       int chunk);
2273 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2274 			       struct ext4_map_blocks *map, int flags);
2275 extern void ext4_ext_truncate(struct inode *);
2276 extern int ext4_ext_punch_hole(struct file *file, loff_t offset,
2277 				loff_t length);
2278 extern void ext4_ext_init(struct super_block *);
2279 extern void ext4_ext_release(struct super_block *);
2280 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2281 			  loff_t len);
2282 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
2283 			  ssize_t len);
2284 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2285 			   struct ext4_map_blocks *map, int flags);
2286 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2287 			__u64 start, __u64 len);
2288 /* move_extent.c */
2289 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2290 			     __u64 start_orig, __u64 start_donor,
2291 			     __u64 len, __u64 *moved_len);
2292 
2293 /* page-io.c */
2294 extern int __init ext4_init_pageio(void);
2295 extern void ext4_exit_pageio(void);
2296 extern void ext4_ioend_wait(struct inode *);
2297 extern void ext4_free_io_end(ext4_io_end_t *io);
2298 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2299 extern int ext4_end_io_nolock(ext4_io_end_t *io);
2300 extern void ext4_io_submit(struct ext4_io_submit *io);
2301 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2302 			       struct page *page,
2303 			       int len,
2304 			       struct writeback_control *wbc);
2305 
2306 /* mmp.c */
2307 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2308 
2309 /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
2310 enum ext4_state_bits {
2311 	BH_Uninit	/* blocks are allocated but uninitialized on disk */
2312 	  = BH_JBDPrivateStart,
2313 	BH_AllocFromCluster,	/* allocated blocks were part of already
2314 				 * allocated cluster. Note that this flag will
2315 				 * never, ever appear in a buffer_head's state
2316 				 * flag. See EXT4_MAP_FROM_CLUSTER to see where
2317 				 * this is used. */
2318 	BH_Da_Mapped,	/* Delayed allocated block that now has a mapping. This
2319 			 * flag is set when ext4_map_blocks is called on a
2320 			 * delayed allocated block to get its real mapping. */
2321 };
2322 
2323 BUFFER_FNS(Uninit, uninit)
2324 TAS_BUFFER_FNS(Uninit, uninit)
2325 BUFFER_FNS(Da_Mapped, da_mapped)
2326 
2327 /*
2328  * Add new method to test wether block and inode bitmaps are properly
2329  * initialized. With uninit_bg reading the block from disk is not enough
2330  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2331  */
2332 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2333 
2334 static inline int bitmap_uptodate(struct buffer_head *bh)
2335 {
2336 	return (buffer_uptodate(bh) &&
2337 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2338 }
2339 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2340 {
2341 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2342 }
2343 
2344 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
2345 
2346 /* For ioend & aio unwritten conversion wait queues */
2347 #define EXT4_WQ_HASH_SZ		37
2348 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2349 					    EXT4_WQ_HASH_SZ])
2350 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2351 					     EXT4_WQ_HASH_SZ])
2352 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2353 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2354 
2355 #define EXT4_RESIZING	0
2356 extern int ext4_resize_begin(struct super_block *sb);
2357 extern void ext4_resize_end(struct super_block *sb);
2358 
2359 #endif	/* __KERNEL__ */
2360 
2361 #include "ext4_extents.h"
2362 
2363 #endif	/* _EXT4_H */
2364