xref: /openbmc/linux/fs/ext4/ext4.h (revision 8f82f840)
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 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
148 				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
149 				 EXT4_MAP_UNINIT)
150 
151 struct ext4_map_blocks {
152 	ext4_fsblk_t m_pblk;
153 	ext4_lblk_t m_lblk;
154 	unsigned int m_len;
155 	unsigned int m_flags;
156 };
157 
158 /*
159  * For delayed allocation tracking
160  */
161 struct mpage_da_data {
162 	struct inode *inode;
163 	sector_t b_blocknr;		/* start block number of extent */
164 	size_t b_size;			/* size of extent */
165 	unsigned long b_state;		/* state of the extent */
166 	unsigned long first_page, next_page;	/* extent of pages */
167 	struct writeback_control *wbc;
168 	int io_done;
169 	int pages_written;
170 	int retval;
171 };
172 
173 /*
174  * Flags for ext4_io_end->flags
175  */
176 #define	EXT4_IO_END_UNWRITTEN	0x0001
177 #define EXT4_IO_END_ERROR	0x0002
178 
179 struct ext4_io_page {
180 	struct page	*p_page;
181 	atomic_t	p_count;
182 };
183 
184 #define MAX_IO_PAGES 128
185 
186 typedef struct ext4_io_end {
187 	struct list_head	list;		/* per-file finished IO list */
188 	struct inode		*inode;		/* file being written to */
189 	unsigned int		flag;		/* unwritten or not */
190 	struct page		*page;		/* page struct for buffer write */
191 	loff_t			offset;		/* offset in the file */
192 	ssize_t			size;		/* size of the extent */
193 	struct work_struct	work;		/* data work queue */
194 	struct kiocb		*iocb;		/* iocb struct for AIO */
195 	int			result;		/* error value for AIO */
196 	int			num_io_pages;
197 	struct ext4_io_page	*pages[MAX_IO_PAGES];
198 } ext4_io_end_t;
199 
200 struct ext4_io_submit {
201 	int			io_op;
202 	struct bio		*io_bio;
203 	ext4_io_end_t		*io_end;
204 	struct ext4_io_page	*io_page;
205 	sector_t		io_next_block;
206 };
207 
208 /*
209  * Special inodes numbers
210  */
211 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
212 #define EXT4_ROOT_INO		 2	/* Root inode */
213 #define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
214 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
215 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
216 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
217 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
218 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
219 
220 /* First non-reserved inode for old ext4 filesystems */
221 #define EXT4_GOOD_OLD_FIRST_INO	11
222 
223 /*
224  * Maximal count of links to a file
225  */
226 #define EXT4_LINK_MAX		65000
227 
228 /*
229  * Macro-instructions used to manage several block sizes
230  */
231 #define EXT4_MIN_BLOCK_SIZE		1024
232 #define	EXT4_MAX_BLOCK_SIZE		65536
233 #define EXT4_MIN_BLOCK_LOG_SIZE		10
234 #define EXT4_MAX_BLOCK_LOG_SIZE		16
235 #ifdef __KERNEL__
236 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
237 #else
238 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
239 #endif
240 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
241 #ifdef __KERNEL__
242 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
243 #else
244 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
245 #endif
246 #ifdef __KERNEL__
247 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
248 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
249 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
250 #else
251 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
252 				 EXT4_GOOD_OLD_INODE_SIZE : \
253 				 (s)->s_inode_size)
254 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
255 				 EXT4_GOOD_OLD_FIRST_INO : \
256 				 (s)->s_first_ino)
257 #endif
258 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
259 
260 /*
261  * Structure of a blocks group descriptor
262  */
263 struct ext4_group_desc
264 {
265 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
266 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
267 	__le32	bg_inode_table_lo;	/* Inodes table block */
268 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
269 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
270 	__le16	bg_used_dirs_count_lo;	/* Directories count */
271 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
272 	__u32	bg_reserved[2];		/* Likely block/inode bitmap checksum */
273 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
274 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
275 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
276 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
277 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
278 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
279 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
280 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
281 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
282 	__u32	bg_reserved2[3];
283 };
284 
285 /*
286  * Structure of a flex block group info
287  */
288 
289 struct flex_groups {
290 	atomic_t free_inodes;
291 	atomic_t free_blocks;
292 	atomic_t used_dirs;
293 };
294 
295 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
296 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
297 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
298 
299 /*
300  * Macro-instructions used to manage group descriptors
301  */
302 #define EXT4_MIN_DESC_SIZE		32
303 #define EXT4_MIN_DESC_SIZE_64BIT	64
304 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
305 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
306 #ifdef __KERNEL__
307 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
308 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
309 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
310 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
311 #else
312 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
313 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
314 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
315 #endif
316 
317 /*
318  * Constants relative to the data blocks
319  */
320 #define	EXT4_NDIR_BLOCKS		12
321 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
322 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
323 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
324 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
325 
326 /*
327  * Inode flags
328  */
329 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
330 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
331 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
332 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
333 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
334 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
335 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
336 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
337 /* Reserved for compression usage... */
338 #define EXT4_DIRTY_FL			0x00000100
339 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
340 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
341 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
342 /* End compression flags --- maybe not all used */
343 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
344 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
345 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
346 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
347 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
348 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
349 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
350 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
351 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
352 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
353 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
354 
355 #define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
356 #define EXT4_FL_USER_MODIFIABLE		0x004B80FF /* User modifiable flags */
357 
358 /* Flags that should be inherited by new inodes from their parent. */
359 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
360 			   EXT4_SYNC_FL | EXT4_IMMUTABLE_FL | EXT4_APPEND_FL |\
361 			   EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
362 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
363 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
364 
365 /* Flags that are appropriate for regular files (all but dir-specific ones). */
366 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
367 
368 /* Flags that are appropriate for non-directories/regular files. */
369 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
370 
371 /* Mask out flags that are inappropriate for the given type of inode. */
372 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
373 {
374 	if (S_ISDIR(mode))
375 		return flags;
376 	else if (S_ISREG(mode))
377 		return flags & EXT4_REG_FLMASK;
378 	else
379 		return flags & EXT4_OTHER_FLMASK;
380 }
381 
382 /*
383  * Inode flags used for atomic set/get
384  */
385 enum {
386 	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
387 	EXT4_INODE_UNRM		= 1,	/* Undelete */
388 	EXT4_INODE_COMPR	= 2,	/* Compress file */
389 	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
390 	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
391 	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
392 	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
393 	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
394 /* Reserved for compression usage... */
395 	EXT4_INODE_DIRTY	= 8,
396 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
397 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
398 	EXT4_INODE_ECOMPR	= 11,	/* Compression error */
399 /* End compression flags --- maybe not all used */
400 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
401 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
402 	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
403 	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
404 	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
405 	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
406 	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
407 	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
408 	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
409 	EXT4_INODE_EOFBLOCKS	= 22,	/* Blocks allocated beyond EOF */
410 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
411 };
412 
413 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
414 #define CHECK_FLAG_VALUE(FLAG) if (!TEST_FLAG_VALUE(FLAG)) { \
415 	printk(KERN_EMERG "EXT4 flag fail: " #FLAG ": %d %d\n", \
416 		EXT4_##FLAG##_FL, EXT4_INODE_##FLAG); BUG_ON(1); }
417 
418 /*
419  * Since it's pretty easy to mix up bit numbers and hex values, and we
420  * can't do a compile-time test for ENUM values, we use a run-time
421  * test to make sure that EXT4_XXX_FL is consistent with respect to
422  * EXT4_INODE_XXX.  If all is well the printk and BUG_ON will all drop
423  * out so it won't cost any extra space in the compiled kernel image.
424  * But it's important that these values are the same, since we are
425  * using EXT4_INODE_XXX to test for the flag values, but EXT4_XX_FL
426  * must be consistent with the values of FS_XXX_FL defined in
427  * include/linux/fs.h and the on-disk values found in ext2, ext3, and
428  * ext4 filesystems, and of course the values defined in e2fsprogs.
429  *
430  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
431  */
432 static inline void ext4_check_flag_values(void)
433 {
434 	CHECK_FLAG_VALUE(SECRM);
435 	CHECK_FLAG_VALUE(UNRM);
436 	CHECK_FLAG_VALUE(COMPR);
437 	CHECK_FLAG_VALUE(SYNC);
438 	CHECK_FLAG_VALUE(IMMUTABLE);
439 	CHECK_FLAG_VALUE(APPEND);
440 	CHECK_FLAG_VALUE(NODUMP);
441 	CHECK_FLAG_VALUE(NOATIME);
442 	CHECK_FLAG_VALUE(DIRTY);
443 	CHECK_FLAG_VALUE(COMPRBLK);
444 	CHECK_FLAG_VALUE(NOCOMPR);
445 	CHECK_FLAG_VALUE(ECOMPR);
446 	CHECK_FLAG_VALUE(INDEX);
447 	CHECK_FLAG_VALUE(IMAGIC);
448 	CHECK_FLAG_VALUE(JOURNAL_DATA);
449 	CHECK_FLAG_VALUE(NOTAIL);
450 	CHECK_FLAG_VALUE(DIRSYNC);
451 	CHECK_FLAG_VALUE(TOPDIR);
452 	CHECK_FLAG_VALUE(HUGE_FILE);
453 	CHECK_FLAG_VALUE(EXTENTS);
454 	CHECK_FLAG_VALUE(EA_INODE);
455 	CHECK_FLAG_VALUE(EOFBLOCKS);
456 	CHECK_FLAG_VALUE(RESERVED);
457 }
458 
459 /* Used to pass group descriptor data when online resize is done */
460 struct ext4_new_group_input {
461 	__u32 group;		/* Group number for this data */
462 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
463 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
464 	__u64 inode_table;	/* Absolute block number of inode table start */
465 	__u32 blocks_count;	/* Total number of blocks in this group */
466 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
467 	__u16 unused;
468 };
469 
470 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
471 struct compat_ext4_new_group_input {
472 	u32 group;
473 	compat_u64 block_bitmap;
474 	compat_u64 inode_bitmap;
475 	compat_u64 inode_table;
476 	u32 blocks_count;
477 	u16 reserved_blocks;
478 	u16 unused;
479 };
480 #endif
481 
482 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
483 struct ext4_new_group_data {
484 	__u32 group;
485 	__u64 block_bitmap;
486 	__u64 inode_bitmap;
487 	__u64 inode_table;
488 	__u32 blocks_count;
489 	__u16 reserved_blocks;
490 	__u16 unused;
491 	__u32 free_blocks_count;
492 };
493 
494 /*
495  * Flags used by ext4_map_blocks()
496  */
497 	/* Allocate any needed blocks and/or convert an unitialized
498 	   extent to be an initialized ext4 */
499 #define EXT4_GET_BLOCKS_CREATE			0x0001
500 	/* Request the creation of an unitialized extent */
501 #define EXT4_GET_BLOCKS_UNINIT_EXT		0x0002
502 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\
503 						 EXT4_GET_BLOCKS_CREATE)
504 	/* Caller is from the delayed allocation writeout path,
505 	   so set the magic i_delalloc_reserve_flag after taking the
506 	   inode allocation semaphore for */
507 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
508 	/* caller is from the direct IO path, request to creation of an
509 	unitialized extents if not allocated, split the uninitialized
510 	extent if blocks has been preallocated already*/
511 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
512 #define EXT4_GET_BLOCKS_CONVERT			0x0010
513 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
514 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
515 	/* Convert extent to initialized after IO complete */
516 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
517 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
518 	/* Punch out blocks of an extent */
519 #define EXT4_GET_BLOCKS_PUNCH_OUT_EXT		0x0020
520 	/* Don't normalize allocation size (used for fallocate) */
521 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
522 
523 /*
524  * Flags used by ext4_free_blocks
525  */
526 #define EXT4_FREE_BLOCKS_METADATA	0x0001
527 #define EXT4_FREE_BLOCKS_FORGET		0x0002
528 #define EXT4_FREE_BLOCKS_VALIDATED	0x0004
529 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE	0x0008
530 
531 /*
532  * ioctl commands
533  */
534 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
535 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
536 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
537 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
538 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
539 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
540 #ifdef CONFIG_JBD2_DEBUG
541 #define EXT4_IOC_WAIT_FOR_READONLY	_IOR('f', 99, long)
542 #endif
543 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
544 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
545 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
546 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
547 #define EXT4_IOC_MIGRATE		_IO('f', 9)
548  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
549  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
550 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
551 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
552 
553 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
554 /*
555  * ioctl commands in 32 bit emulation
556  */
557 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
558 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
559 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
560 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
561 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
562 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
563 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
564 #define EXT4_IOC32_GROUP_ADD		_IOW('f', 8, struct compat_ext4_new_group_input)
565 #ifdef CONFIG_JBD2_DEBUG
566 #define EXT4_IOC32_WAIT_FOR_READONLY	_IOR('f', 99, int)
567 #endif
568 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
569 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
570 #endif
571 
572 /* Max physical block we can address w/o extents */
573 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
574 
575 /*
576  * Structure of an inode on the disk
577  */
578 struct ext4_inode {
579 	__le16	i_mode;		/* File mode */
580 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
581 	__le32	i_size_lo;	/* Size in bytes */
582 	__le32	i_atime;	/* Access time */
583 	__le32	i_ctime;	/* Inode Change time */
584 	__le32	i_mtime;	/* Modification time */
585 	__le32	i_dtime;	/* Deletion Time */
586 	__le16	i_gid;		/* Low 16 bits of Group Id */
587 	__le16	i_links_count;	/* Links count */
588 	__le32	i_blocks_lo;	/* Blocks count */
589 	__le32	i_flags;	/* File flags */
590 	union {
591 		struct {
592 			__le32  l_i_version;
593 		} linux1;
594 		struct {
595 			__u32  h_i_translator;
596 		} hurd1;
597 		struct {
598 			__u32  m_i_reserved1;
599 		} masix1;
600 	} osd1;				/* OS dependent 1 */
601 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
602 	__le32	i_generation;	/* File version (for NFS) */
603 	__le32	i_file_acl_lo;	/* File ACL */
604 	__le32	i_size_high;
605 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
606 	union {
607 		struct {
608 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
609 			__le16	l_i_file_acl_high;
610 			__le16	l_i_uid_high;	/* these 2 fields */
611 			__le16	l_i_gid_high;	/* were reserved2[0] */
612 			__u32	l_i_reserved2;
613 		} linux2;
614 		struct {
615 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
616 			__u16	h_i_mode_high;
617 			__u16	h_i_uid_high;
618 			__u16	h_i_gid_high;
619 			__u32	h_i_author;
620 		} hurd2;
621 		struct {
622 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
623 			__le16	m_i_file_acl_high;
624 			__u32	m_i_reserved2[2];
625 		} masix2;
626 	} osd2;				/* OS dependent 2 */
627 	__le16	i_extra_isize;
628 	__le16	i_pad1;
629 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
630 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
631 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
632 	__le32  i_crtime;       /* File Creation time */
633 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
634 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
635 };
636 
637 struct move_extent {
638 	__u32 reserved;		/* should be zero */
639 	__u32 donor_fd;		/* donor file descriptor */
640 	__u64 orig_start;	/* logical start offset in block for orig */
641 	__u64 donor_start;	/* logical start offset in block for donor */
642 	__u64 len;		/* block length to be moved */
643 	__u64 moved_len;	/* moved block length */
644 };
645 
646 #define EXT4_EPOCH_BITS 2
647 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
648 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
649 
650 /*
651  * Extended fields will fit into an inode if the filesystem was formatted
652  * with large inodes (-I 256 or larger) and there are not currently any EAs
653  * consuming all of the available space. For new inodes we always reserve
654  * enough space for the kernel's known extended fields, but for inodes
655  * created with an old kernel this might not have been the case. None of
656  * the extended inode fields is critical for correct filesystem operation.
657  * This macro checks if a certain field fits in the inode. Note that
658  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
659  */
660 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
661 	((offsetof(typeof(*ext4_inode), field) +	\
662 	  sizeof((ext4_inode)->field))			\
663 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
664 	    (einode)->i_extra_isize))			\
665 
666 static inline __le32 ext4_encode_extra_time(struct timespec *time)
667 {
668        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
669 			   (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
670                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
671 }
672 
673 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
674 {
675        if (sizeof(time->tv_sec) > 4)
676 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
677 			       << 32;
678        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
679 }
680 
681 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
682 do {									       \
683 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
684 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
685 		(raw_inode)->xtime ## _extra =				       \
686 				ext4_encode_extra_time(&(inode)->xtime);       \
687 } while (0)
688 
689 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
690 do {									       \
691 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
692 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
693 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
694 		(raw_inode)->xtime ## _extra =				       \
695 				ext4_encode_extra_time(&(einode)->xtime);      \
696 } while (0)
697 
698 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
699 do {									       \
700 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
701 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
702 		ext4_decode_extra_time(&(inode)->xtime,			       \
703 				       raw_inode->xtime ## _extra);	       \
704 	else								       \
705 		(inode)->xtime.tv_nsec = 0;				       \
706 } while (0)
707 
708 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
709 do {									       \
710 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
711 		(einode)->xtime.tv_sec = 				       \
712 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
713 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
714 		ext4_decode_extra_time(&(einode)->xtime,		       \
715 				       raw_inode->xtime ## _extra);	       \
716 	else								       \
717 		(einode)->xtime.tv_nsec = 0;				       \
718 } while (0)
719 
720 #define i_disk_version osd1.linux1.l_i_version
721 
722 #if defined(__KERNEL__) || defined(__linux__)
723 #define i_reserved1	osd1.linux1.l_i_reserved1
724 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
725 #define i_blocks_high	osd2.linux2.l_i_blocks_high
726 #define i_uid_low	i_uid
727 #define i_gid_low	i_gid
728 #define i_uid_high	osd2.linux2.l_i_uid_high
729 #define i_gid_high	osd2.linux2.l_i_gid_high
730 #define i_reserved2	osd2.linux2.l_i_reserved2
731 
732 #elif defined(__GNU__)
733 
734 #define i_translator	osd1.hurd1.h_i_translator
735 #define i_uid_high	osd2.hurd2.h_i_uid_high
736 #define i_gid_high	osd2.hurd2.h_i_gid_high
737 #define i_author	osd2.hurd2.h_i_author
738 
739 #elif defined(__masix__)
740 
741 #define i_reserved1	osd1.masix1.m_i_reserved1
742 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
743 #define i_reserved2	osd2.masix2.m_i_reserved2
744 
745 #endif /* defined(__KERNEL__) || defined(__linux__) */
746 
747 /*
748  * storage for cached extent
749  * If ec_len == 0, then the cache is invalid.
750  * If ec_start == 0, then the cache represents a gap (null mapping)
751  */
752 struct ext4_ext_cache {
753 	ext4_fsblk_t	ec_start;
754 	ext4_lblk_t	ec_block;
755 	__u32		ec_len; /* must be 32bit to return holes */
756 };
757 
758 /*
759  * fourth extended file system inode data in memory
760  */
761 struct ext4_inode_info {
762 	__le32	i_data[15];	/* unconverted */
763 	__u32	i_dtime;
764 	ext4_fsblk_t	i_file_acl;
765 
766 	/*
767 	 * i_block_group is the number of the block group which contains
768 	 * this file's inode.  Constant across the lifetime of the inode,
769 	 * it is ued for making block allocation decisions - we try to
770 	 * place a file's data blocks near its inode block, and new inodes
771 	 * near to their parent directory's inode.
772 	 */
773 	ext4_group_t	i_block_group;
774 	ext4_lblk_t	i_dir_start_lookup;
775 #if (BITS_PER_LONG < 64)
776 	unsigned long	i_state_flags;		/* Dynamic state flags */
777 #endif
778 	unsigned long	i_flags;
779 
780 #ifdef CONFIG_EXT4_FS_XATTR
781 	/*
782 	 * Extended attributes can be read independently of the main file
783 	 * data. Taking i_mutex even when reading would cause contention
784 	 * between readers of EAs and writers of regular file data, so
785 	 * instead we synchronize on xattr_sem when reading or changing
786 	 * EAs.
787 	 */
788 	struct rw_semaphore xattr_sem;
789 #endif
790 
791 	struct list_head i_orphan;	/* unlinked but open inodes */
792 
793 	/*
794 	 * i_disksize keeps track of what the inode size is ON DISK, not
795 	 * in memory.  During truncate, i_size is set to the new size by
796 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
797 	 * set i_disksize to 0 until the truncate is actually under way.
798 	 *
799 	 * The intent is that i_disksize always represents the blocks which
800 	 * are used by this file.  This allows recovery to restart truncate
801 	 * on orphans if we crash during truncate.  We actually write i_disksize
802 	 * into the on-disk inode when writing inodes out, instead of i_size.
803 	 *
804 	 * The only time when i_disksize and i_size may be different is when
805 	 * a truncate is in progress.  The only things which change i_disksize
806 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
807 	 */
808 	loff_t	i_disksize;
809 
810 	/*
811 	 * i_data_sem is for serialising ext4_truncate() against
812 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
813 	 * data tree are chopped off during truncate. We can't do that in
814 	 * ext4 because whenever we perform intermediate commits during
815 	 * truncate, the inode and all the metadata blocks *must* be in a
816 	 * consistent state which allows truncation of the orphans to restart
817 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
818 	 * by other means, so we have i_data_sem.
819 	 */
820 	struct rw_semaphore i_data_sem;
821 	struct inode vfs_inode;
822 	struct jbd2_inode *jinode;
823 
824 	struct ext4_ext_cache i_cached_extent;
825 	/*
826 	 * File creation time. Its function is same as that of
827 	 * struct timespec i_{a,c,m}time in the generic inode.
828 	 */
829 	struct timespec i_crtime;
830 
831 	/* mballoc */
832 	struct list_head i_prealloc_list;
833 	spinlock_t i_prealloc_lock;
834 
835 	/* ialloc */
836 	ext4_group_t	i_last_alloc_group;
837 
838 	/* allocation reservation info for delalloc */
839 	unsigned int i_reserved_data_blocks;
840 	unsigned int i_reserved_meta_blocks;
841 	unsigned int i_allocated_meta_blocks;
842 	ext4_lblk_t i_da_metadata_calc_last_lblock;
843 	int i_da_metadata_calc_len;
844 
845 	/* on-disk additional length */
846 	__u16 i_extra_isize;
847 
848 #ifdef CONFIG_QUOTA
849 	/* quota space reservation, managed internally by quota code */
850 	qsize_t i_reserved_quota;
851 #endif
852 
853 	/* completed IOs that might need unwritten extents handling */
854 	struct list_head i_completed_io_list;
855 	spinlock_t i_completed_io_lock;
856 	atomic_t i_ioend_count;	/* Number of outstanding io_end structs */
857 	/* current io_end structure for async DIO write*/
858 	ext4_io_end_t *cur_aio_dio;
859 	atomic_t i_aiodio_unwritten; /* Nr. of inflight conversions pending */
860 
861 	spinlock_t i_block_reservation_lock;
862 
863 	/*
864 	 * Transactions that contain inode's metadata needed to complete
865 	 * fsync and fdatasync, respectively.
866 	 */
867 	tid_t i_sync_tid;
868 	tid_t i_datasync_tid;
869 };
870 
871 /*
872  * File system states
873  */
874 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
875 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
876 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
877 
878 /*
879  * Misc. filesystem flags
880  */
881 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
882 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
883 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
884 
885 /*
886  * Mount flags
887  */
888 #define EXT4_MOUNT_OLDALLOC		0x00002  /* Don't use the new Orlov allocator */
889 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
890 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
891 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
892 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
893 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
894 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
895 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
896 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
897 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
898 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
899 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
900 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
901 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
902 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
903 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
904 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
905 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
906 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
907 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
908 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
909 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
910 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
911 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
912 #define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
913 #define EXT4_MOUNT_MBLK_IO_SUBMIT	0x4000000 /* multi-block io submits */
914 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
915 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
916 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
917 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
918 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
919 
920 #define clear_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt &= \
921 						~EXT4_MOUNT_##opt
922 #define set_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt |= \
923 						EXT4_MOUNT_##opt
924 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
925 					 EXT4_MOUNT_##opt)
926 
927 #define clear_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 &= \
928 						~EXT4_MOUNT2_##opt
929 #define set_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 |= \
930 						EXT4_MOUNT2_##opt
931 #define test_opt2(sb, opt)		(EXT4_SB(sb)->s_mount_opt2 & \
932 					 EXT4_MOUNT2_##opt)
933 
934 #define ext4_set_bit			__test_and_set_bit_le
935 #define ext4_set_bit_atomic		ext2_set_bit_atomic
936 #define ext4_clear_bit			__test_and_clear_bit_le
937 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
938 #define ext4_test_bit			test_bit_le
939 #define ext4_find_first_zero_bit	find_first_zero_bit_le
940 #define ext4_find_next_zero_bit		find_next_zero_bit_le
941 #define ext4_find_next_bit		find_next_bit_le
942 
943 /*
944  * Maximal mount counts between two filesystem checks
945  */
946 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
947 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
948 
949 /*
950  * Behaviour when detecting errors
951  */
952 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
953 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
954 #define EXT4_ERRORS_PANIC		3	/* Panic */
955 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
956 
957 /*
958  * Structure of the super block
959  */
960 struct ext4_super_block {
961 /*00*/	__le32	s_inodes_count;		/* Inodes count */
962 	__le32	s_blocks_count_lo;	/* Blocks count */
963 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
964 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
965 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
966 	__le32	s_first_data_block;	/* First Data Block */
967 	__le32	s_log_block_size;	/* Block size */
968 	__le32	s_obso_log_frag_size;	/* Obsoleted fragment size */
969 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
970 	__le32	s_obso_frags_per_group;	/* Obsoleted fragments per group */
971 	__le32	s_inodes_per_group;	/* # Inodes per group */
972 	__le32	s_mtime;		/* Mount time */
973 /*30*/	__le32	s_wtime;		/* Write time */
974 	__le16	s_mnt_count;		/* Mount count */
975 	__le16	s_max_mnt_count;	/* Maximal mount count */
976 	__le16	s_magic;		/* Magic signature */
977 	__le16	s_state;		/* File system state */
978 	__le16	s_errors;		/* Behaviour when detecting errors */
979 	__le16	s_minor_rev_level;	/* minor revision level */
980 /*40*/	__le32	s_lastcheck;		/* time of last check */
981 	__le32	s_checkinterval;	/* max. time between checks */
982 	__le32	s_creator_os;		/* OS */
983 	__le32	s_rev_level;		/* Revision level */
984 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
985 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
986 	/*
987 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
988 	 *
989 	 * Note: the difference between the compatible feature set and
990 	 * the incompatible feature set is that if there is a bit set
991 	 * in the incompatible feature set that the kernel doesn't
992 	 * know about, it should refuse to mount the filesystem.
993 	 *
994 	 * e2fsck's requirements are more strict; if it doesn't know
995 	 * about a feature in either the compatible or incompatible
996 	 * feature set, it must abort and not try to meddle with
997 	 * things it doesn't understand...
998 	 */
999 	__le32	s_first_ino;		/* First non-reserved inode */
1000 	__le16  s_inode_size;		/* size of inode structure */
1001 	__le16	s_block_group_nr;	/* block group # of this superblock */
1002 	__le32	s_feature_compat;	/* compatible feature set */
1003 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
1004 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
1005 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
1006 /*78*/	char	s_volume_name[16];	/* volume name */
1007 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
1008 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
1009 	/*
1010 	 * Performance hints.  Directory preallocation should only
1011 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1012 	 */
1013 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
1014 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
1015 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
1016 	/*
1017 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1018 	 */
1019 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
1020 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
1021 	__le32	s_journal_dev;		/* device number of journal file */
1022 	__le32	s_last_orphan;		/* start of list of inodes to delete */
1023 	__le32	s_hash_seed[4];		/* HTREE hash seed */
1024 	__u8	s_def_hash_version;	/* Default hash version to use */
1025 	__u8	s_jnl_backup_type;
1026 	__le16  s_desc_size;		/* size of group descriptor */
1027 /*100*/	__le32	s_default_mount_opts;
1028 	__le32	s_first_meta_bg;	/* First metablock block group */
1029 	__le32	s_mkfs_time;		/* When the filesystem was created */
1030 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
1031 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1032 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
1033 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
1034 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
1035 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
1036 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
1037 	__le32	s_flags;		/* Miscellaneous flags */
1038 	__le16  s_raid_stride;		/* RAID stride */
1039 	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1040 	__le64  s_mmp_block;            /* Block for multi-mount protection */
1041 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1042 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
1043 	__u8	s_reserved_char_pad;
1044 	__le16  s_reserved_pad;
1045 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1046 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
1047 	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
1048 	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
1049 					      snapshot's future use */
1050 	__le32	s_snapshot_list;	/* inode number of the head of the
1051 					   on-disk snapshot list */
1052 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1053 	__le32	s_error_count;		/* number of fs errors */
1054 	__le32	s_first_error_time;	/* first time an error happened */
1055 	__le32	s_first_error_ino;	/* inode involved in first error */
1056 	__le64	s_first_error_block;	/* block involved of first error */
1057 	__u8	s_first_error_func[32];	/* function where the error happened */
1058 	__le32	s_first_error_line;	/* line number where error happened */
1059 	__le32	s_last_error_time;	/* most recent time of an error */
1060 	__le32	s_last_error_ino;	/* inode involved in last error */
1061 	__le32	s_last_error_line;	/* line number where error happened */
1062 	__le64	s_last_error_block;	/* block involved of last error */
1063 	__u8	s_last_error_func[32];	/* function where the error happened */
1064 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1065 	__u8	s_mount_opts[64];
1066 	__le32	s_reserved[112];        /* Padding to the end of the block */
1067 };
1068 
1069 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1070 
1071 #ifdef __KERNEL__
1072 
1073 /*
1074  * run-time mount flags
1075  */
1076 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
1077 #define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
1078 
1079 /*
1080  * fourth extended-fs super-block data in memory
1081  */
1082 struct ext4_sb_info {
1083 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
1084 	unsigned long s_inodes_per_block;/* Number of inodes per block */
1085 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
1086 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
1087 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
1088 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
1089 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
1090 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1091 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1092 	unsigned long s_overhead_last;  /* Last calculated overhead */
1093 	unsigned long s_blocks_last;    /* Last seen block count */
1094 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
1095 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
1096 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
1097 	struct buffer_head **s_group_desc;
1098 	unsigned int s_mount_opt;
1099 	unsigned int s_mount_opt2;
1100 	unsigned int s_mount_flags;
1101 	ext4_fsblk_t s_sb_block;
1102 	uid_t s_resuid;
1103 	gid_t s_resgid;
1104 	unsigned short s_mount_state;
1105 	unsigned short s_pad;
1106 	int s_addr_per_block_bits;
1107 	int s_desc_per_block_bits;
1108 	int s_inode_size;
1109 	int s_first_ino;
1110 	unsigned int s_inode_readahead_blks;
1111 	unsigned int s_inode_goal;
1112 	spinlock_t s_next_gen_lock;
1113 	u32 s_next_generation;
1114 	u32 s_hash_seed[4];
1115 	int s_def_hash_version;
1116 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
1117 	struct percpu_counter s_freeblocks_counter;
1118 	struct percpu_counter s_freeinodes_counter;
1119 	struct percpu_counter s_dirs_counter;
1120 	struct percpu_counter s_dirtyblocks_counter;
1121 	struct blockgroup_lock *s_blockgroup_lock;
1122 	struct proc_dir_entry *s_proc;
1123 	struct kobject s_kobj;
1124 	struct completion s_kobj_unregister;
1125 
1126 	/* Journaling */
1127 	struct journal_s *s_journal;
1128 	struct list_head s_orphan;
1129 	struct mutex s_orphan_lock;
1130 	unsigned long s_resize_flags;		/* Flags indicating if there
1131 						   is a resizer */
1132 	unsigned long s_commit_interval;
1133 	u32 s_max_batch_time;
1134 	u32 s_min_batch_time;
1135 	struct block_device *journal_bdev;
1136 #ifdef CONFIG_JBD2_DEBUG
1137 	struct timer_list turn_ro_timer;	/* For turning read-only (crash simulation) */
1138 	wait_queue_head_t ro_wait_queue;	/* For people waiting for the fs to go read-only */
1139 #endif
1140 #ifdef CONFIG_QUOTA
1141 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
1142 	int s_jquota_fmt;			/* Format of quota to use */
1143 #endif
1144 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1145 	struct rb_root system_blks;
1146 
1147 #ifdef EXTENTS_STATS
1148 	/* ext4 extents stats */
1149 	unsigned long s_ext_min;
1150 	unsigned long s_ext_max;
1151 	unsigned long s_depth_max;
1152 	spinlock_t s_ext_stats_lock;
1153 	unsigned long s_ext_blocks;
1154 	unsigned long s_ext_extents;
1155 #endif
1156 	/* ext4 extent cache stats */
1157 	unsigned long extent_cache_hits;
1158 	unsigned long extent_cache_misses;
1159 
1160 	/* for buddy allocator */
1161 	struct ext4_group_info ***s_group_info;
1162 	struct inode *s_buddy_cache;
1163 	spinlock_t s_md_lock;
1164 	unsigned short *s_mb_offsets;
1165 	unsigned int *s_mb_maxs;
1166 
1167 	/* tunables */
1168 	unsigned long s_stripe;
1169 	unsigned int s_mb_stream_request;
1170 	unsigned int s_mb_max_to_scan;
1171 	unsigned int s_mb_min_to_scan;
1172 	unsigned int s_mb_stats;
1173 	unsigned int s_mb_order2_reqs;
1174 	unsigned int s_mb_group_prealloc;
1175 	unsigned int s_max_writeback_mb_bump;
1176 	/* where last allocation was done - for stream allocation */
1177 	unsigned long s_mb_last_group;
1178 	unsigned long s_mb_last_start;
1179 
1180 	/* stats for buddy allocator */
1181 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1182 	atomic_t s_bal_success;	/* we found long enough chunks */
1183 	atomic_t s_bal_allocated;	/* in blocks */
1184 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1185 	atomic_t s_bal_goals;	/* goal hits */
1186 	atomic_t s_bal_breaks;	/* too long searches */
1187 	atomic_t s_bal_2orders;	/* 2^order hits */
1188 	spinlock_t s_bal_lock;
1189 	unsigned long s_mb_buddies_generated;
1190 	unsigned long long s_mb_generation_time;
1191 	atomic_t s_mb_lost_chunks;
1192 	atomic_t s_mb_preallocated;
1193 	atomic_t s_mb_discarded;
1194 	atomic_t s_lock_busy;
1195 
1196 	/* locality groups */
1197 	struct ext4_locality_group __percpu *s_locality_groups;
1198 
1199 	/* for write statistics */
1200 	unsigned long s_sectors_written_start;
1201 	u64 s_kbytes_written;
1202 
1203 	unsigned int s_log_groups_per_flex;
1204 	struct flex_groups *s_flex_groups;
1205 
1206 	/* workqueue for dio unwritten */
1207 	struct workqueue_struct *dio_unwritten_wq;
1208 
1209 	/* timer for periodic error stats printing */
1210 	struct timer_list s_err_report;
1211 
1212 	/* Lazy inode table initialization info */
1213 	struct ext4_li_request *s_li_request;
1214 	/* Wait multiplier for lazy initialization thread */
1215 	unsigned int s_li_wait_mult;
1216 
1217 	/* Kernel thread for multiple mount protection */
1218 	struct task_struct *s_mmp_tsk;
1219 
1220 	/* record the last minlen when FITRIM is called. */
1221 	atomic_t s_last_trim_minblks;
1222 };
1223 
1224 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1225 {
1226 	return sb->s_fs_info;
1227 }
1228 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1229 {
1230 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1231 }
1232 
1233 static inline struct timespec ext4_current_time(struct inode *inode)
1234 {
1235 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1236 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1237 }
1238 
1239 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1240 {
1241 	return ino == EXT4_ROOT_INO ||
1242 		ino == EXT4_JOURNAL_INO ||
1243 		ino == EXT4_RESIZE_INO ||
1244 		(ino >= EXT4_FIRST_INO(sb) &&
1245 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1246 }
1247 
1248 /*
1249  * Inode dynamic state flags
1250  */
1251 enum {
1252 	EXT4_STATE_JDATA,		/* journaled data exists */
1253 	EXT4_STATE_NEW,			/* inode is newly created */
1254 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1255 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1256 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1257 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1258 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1259 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1260 	EXT4_STATE_DELALLOC_RESERVED,	/* blks already reserved for delalloc */
1261 };
1262 
1263 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
1264 static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
1265 {									\
1266 	return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);	\
1267 }									\
1268 static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
1269 {									\
1270 	set_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1271 }									\
1272 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1273 {									\
1274 	clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1275 }
1276 
1277 EXT4_INODE_BIT_FNS(flag, flags, 0)
1278 #if (BITS_PER_LONG < 64)
1279 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1280 
1281 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1282 {
1283 	(ei)->i_state_flags = 0;
1284 }
1285 #else
1286 EXT4_INODE_BIT_FNS(state, flags, 32)
1287 
1288 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1289 {
1290 	/* We depend on the fact that callers will set i_flags */
1291 }
1292 #endif
1293 #else
1294 /* Assume that user mode programs are passing in an ext4fs superblock, not
1295  * a kernel struct super_block.  This will allow us to call the feature-test
1296  * macros from user land. */
1297 #define EXT4_SB(sb)	(sb)
1298 #endif
1299 
1300 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1301 
1302 /*
1303  * Codes for operating systems
1304  */
1305 #define EXT4_OS_LINUX		0
1306 #define EXT4_OS_HURD		1
1307 #define EXT4_OS_MASIX		2
1308 #define EXT4_OS_FREEBSD		3
1309 #define EXT4_OS_LITES		4
1310 
1311 /*
1312  * Revision levels
1313  */
1314 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1315 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1316 
1317 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1318 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1319 
1320 #define EXT4_GOOD_OLD_INODE_SIZE 128
1321 
1322 /*
1323  * Feature set definitions
1324  */
1325 
1326 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1327 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1328 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1329 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1330 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1331 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1332 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1333 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1334 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1335 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1336 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1337 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1338 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1339 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1340 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1341 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1342 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1343 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1344 
1345 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1346 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1347 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1348 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1349 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1350 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1351 
1352 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1353 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1354 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1355 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1356 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1357 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1358 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1359 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
1360 
1361 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1362 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1363 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1364 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1365 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1366 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1367 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1368 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1369 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1370 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1371 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1372 
1373 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1374 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1375 					 EXT4_FEATURE_INCOMPAT_META_BG)
1376 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1377 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1378 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1379 
1380 #define EXT3_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1381 #define EXT3_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1382 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1383 					 EXT4_FEATURE_INCOMPAT_META_BG)
1384 #define EXT3_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1385 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1386 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1387 
1388 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1389 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1390 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1391 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1392 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1393 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1394 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1395 					 EXT4_FEATURE_INCOMPAT_MMP)
1396 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1397 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1398 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1399 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1400 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1401 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1402 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
1403 
1404 /*
1405  * Default values for user and/or group using reserved blocks
1406  */
1407 #define	EXT4_DEF_RESUID		0
1408 #define	EXT4_DEF_RESGID		0
1409 
1410 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1411 
1412 /*
1413  * Default mount options
1414  */
1415 #define EXT4_DEFM_DEBUG		0x0001
1416 #define EXT4_DEFM_BSDGROUPS	0x0002
1417 #define EXT4_DEFM_XATTR_USER	0x0004
1418 #define EXT4_DEFM_ACL		0x0008
1419 #define EXT4_DEFM_UID16		0x0010
1420 #define EXT4_DEFM_JMODE		0x0060
1421 #define EXT4_DEFM_JMODE_DATA	0x0020
1422 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1423 #define EXT4_DEFM_JMODE_WBACK	0x0060
1424 #define EXT4_DEFM_NOBARRIER	0x0100
1425 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1426 #define EXT4_DEFM_DISCARD	0x0400
1427 #define EXT4_DEFM_NODELALLOC	0x0800
1428 
1429 /*
1430  * Default journal batch times
1431  */
1432 #define EXT4_DEF_MIN_BATCH_TIME	0
1433 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1434 
1435 /*
1436  * Minimum number of groups in a flexgroup before we separate out
1437  * directories into the first block group of a flexgroup
1438  */
1439 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1440 
1441 /*
1442  * Structure of a directory entry
1443  */
1444 #define EXT4_NAME_LEN 255
1445 
1446 struct ext4_dir_entry {
1447 	__le32	inode;			/* Inode number */
1448 	__le16	rec_len;		/* Directory entry length */
1449 	__le16	name_len;		/* Name length */
1450 	char	name[EXT4_NAME_LEN];	/* File name */
1451 };
1452 
1453 /*
1454  * The new version of the directory entry.  Since EXT4 structures are
1455  * stored in intel byte order, and the name_len field could never be
1456  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1457  * file_type field.
1458  */
1459 struct ext4_dir_entry_2 {
1460 	__le32	inode;			/* Inode number */
1461 	__le16	rec_len;		/* Directory entry length */
1462 	__u8	name_len;		/* Name length */
1463 	__u8	file_type;
1464 	char	name[EXT4_NAME_LEN];	/* File name */
1465 };
1466 
1467 /*
1468  * Ext4 directory file types.  Only the low 3 bits are used.  The
1469  * other bits are reserved for now.
1470  */
1471 #define EXT4_FT_UNKNOWN		0
1472 #define EXT4_FT_REG_FILE	1
1473 #define EXT4_FT_DIR		2
1474 #define EXT4_FT_CHRDEV		3
1475 #define EXT4_FT_BLKDEV		4
1476 #define EXT4_FT_FIFO		5
1477 #define EXT4_FT_SOCK		6
1478 #define EXT4_FT_SYMLINK		7
1479 
1480 #define EXT4_FT_MAX		8
1481 
1482 /*
1483  * EXT4_DIR_PAD defines the directory entries boundaries
1484  *
1485  * NOTE: It must be a multiple of 4
1486  */
1487 #define EXT4_DIR_PAD			4
1488 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1489 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1490 					 ~EXT4_DIR_ROUND)
1491 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1492 
1493 /*
1494  * If we ever get support for fs block sizes > page_size, we'll need
1495  * to remove the #if statements in the next two functions...
1496  */
1497 static inline unsigned int
1498 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1499 {
1500 	unsigned len = le16_to_cpu(dlen);
1501 
1502 #if (PAGE_CACHE_SIZE >= 65536)
1503 	if (len == EXT4_MAX_REC_LEN || len == 0)
1504 		return blocksize;
1505 	return (len & 65532) | ((len & 3) << 16);
1506 #else
1507 	return len;
1508 #endif
1509 }
1510 
1511 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1512 {
1513 	if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1514 		BUG();
1515 #if (PAGE_CACHE_SIZE >= 65536)
1516 	if (len < 65536)
1517 		return cpu_to_le16(len);
1518 	if (len == blocksize) {
1519 		if (blocksize == 65536)
1520 			return cpu_to_le16(EXT4_MAX_REC_LEN);
1521 		else
1522 			return cpu_to_le16(0);
1523 	}
1524 	return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1525 #else
1526 	return cpu_to_le16(len);
1527 #endif
1528 }
1529 
1530 /*
1531  * Hash Tree Directory indexing
1532  * (c) Daniel Phillips, 2001
1533  */
1534 
1535 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1536 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1537 		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1538 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1539 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1540 
1541 /* Legal values for the dx_root hash_version field: */
1542 
1543 #define DX_HASH_LEGACY		0
1544 #define DX_HASH_HALF_MD4	1
1545 #define DX_HASH_TEA		2
1546 #define DX_HASH_LEGACY_UNSIGNED	3
1547 #define DX_HASH_HALF_MD4_UNSIGNED	4
1548 #define DX_HASH_TEA_UNSIGNED		5
1549 
1550 #ifdef __KERNEL__
1551 
1552 /* hash info structure used by the directory hash */
1553 struct dx_hash_info
1554 {
1555 	u32		hash;
1556 	u32		minor_hash;
1557 	int		hash_version;
1558 	u32		*seed;
1559 };
1560 
1561 #define EXT4_HTREE_EOF	0x7fffffff
1562 
1563 /*
1564  * Control parameters used by ext4_htree_next_block
1565  */
1566 #define HASH_NB_ALWAYS		1
1567 
1568 
1569 /*
1570  * Describe an inode's exact location on disk and in memory
1571  */
1572 struct ext4_iloc
1573 {
1574 	struct buffer_head *bh;
1575 	unsigned long offset;
1576 	ext4_group_t block_group;
1577 };
1578 
1579 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1580 {
1581 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1582 }
1583 
1584 /*
1585  * This structure is stuffed into the struct file's private_data field
1586  * for directories.  It is where we put information so that we can do
1587  * readdir operations in hash tree order.
1588  */
1589 struct dir_private_info {
1590 	struct rb_root	root;
1591 	struct rb_node	*curr_node;
1592 	struct fname	*extra_fname;
1593 	loff_t		last_pos;
1594 	__u32		curr_hash;
1595 	__u32		curr_minor_hash;
1596 	__u32		next_hash;
1597 };
1598 
1599 /* calculate the first block number of the group */
1600 static inline ext4_fsblk_t
1601 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1602 {
1603 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1604 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1605 }
1606 
1607 /*
1608  * Special error return code only used by dx_probe() and its callers.
1609  */
1610 #define ERR_BAD_DX_DIR	-75000
1611 
1612 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1613 			ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1614 
1615 /*
1616  * Timeout and state flag for lazy initialization inode thread.
1617  */
1618 #define EXT4_DEF_LI_WAIT_MULT			10
1619 #define EXT4_DEF_LI_MAX_START_DELAY		5
1620 #define EXT4_LAZYINIT_QUIT			0x0001
1621 #define EXT4_LAZYINIT_RUNNING			0x0002
1622 
1623 /*
1624  * Lazy inode table initialization info
1625  */
1626 struct ext4_lazy_init {
1627 	unsigned long		li_state;
1628 	struct list_head	li_request_list;
1629 	struct mutex		li_list_mtx;
1630 };
1631 
1632 struct ext4_li_request {
1633 	struct super_block	*lr_super;
1634 	struct ext4_sb_info	*lr_sbi;
1635 	ext4_group_t		lr_next_group;
1636 	struct list_head	lr_request;
1637 	unsigned long		lr_next_sched;
1638 	unsigned long		lr_timeout;
1639 };
1640 
1641 struct ext4_features {
1642 	struct kobject f_kobj;
1643 	struct completion f_kobj_unregister;
1644 };
1645 
1646 /*
1647  * This structure will be used for multiple mount protection. It will be
1648  * written into the block number saved in the s_mmp_block field in the
1649  * superblock. Programs that check MMP should assume that if
1650  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1651  * to use the filesystem, regardless of how old the timestamp is.
1652  */
1653 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1654 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1655 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1656 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1657 
1658 struct mmp_struct {
1659 	__le32	mmp_magic;		/* Magic number for MMP */
1660 	__le32	mmp_seq;		/* Sequence no. updated periodically */
1661 
1662 	/*
1663 	 * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1664 	 * purposes and do not affect the correctness of the algorithm
1665 	 */
1666 	__le64	mmp_time;		/* Time last updated */
1667 	char	mmp_nodename[64];	/* Node which last updated MMP block */
1668 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
1669 
1670 	/*
1671 	 * mmp_check_interval is used to verify if the MMP block has been
1672 	 * updated on the block device. The value is updated based on the
1673 	 * maximum time to write the MMP block during an update cycle.
1674 	 */
1675 	__le16	mmp_check_interval;
1676 
1677 	__le16	mmp_pad1;
1678 	__le32	mmp_pad2[227];
1679 };
1680 
1681 /* arguments passed to the mmp thread */
1682 struct mmpd_data {
1683 	struct buffer_head *bh; /* bh from initial read_mmp_block() */
1684 	struct super_block *sb;  /* super block of the fs */
1685 };
1686 
1687 /*
1688  * Check interval multiplier
1689  * The MMP block is written every update interval and initially checked every
1690  * update interval x the multiplier (the value is then adapted based on the
1691  * write latency). The reason is that writes can be delayed under load and we
1692  * don't want readers to incorrectly assume that the filesystem is no longer
1693  * in use.
1694  */
1695 #define EXT4_MMP_CHECK_MULT		2UL
1696 
1697 /*
1698  * Minimum interval for MMP checking in seconds.
1699  */
1700 #define EXT4_MMP_MIN_CHECK_INTERVAL	5UL
1701 
1702 /*
1703  * Maximum interval for MMP checking in seconds.
1704  */
1705 #define EXT4_MMP_MAX_CHECK_INTERVAL	300UL
1706 
1707 /*
1708  * Function prototypes
1709  */
1710 
1711 /*
1712  * Ok, these declarations are also in <linux/kernel.h> but none of the
1713  * ext4 source programs needs to include it so they are duplicated here.
1714  */
1715 # define NORET_TYPE	/**/
1716 # define ATTRIB_NORET	__attribute__((noreturn))
1717 # define NORET_AND	noreturn,
1718 
1719 /* bitmap.c */
1720 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
1721 
1722 /* balloc.c */
1723 extern unsigned int ext4_block_group(struct super_block *sb,
1724 			ext4_fsblk_t blocknr);
1725 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1726 			ext4_fsblk_t blocknr);
1727 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1728 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1729 			ext4_group_t group);
1730 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1731 					 ext4_fsblk_t goal,
1732 					 unsigned int flags,
1733 					 unsigned long *count,
1734 					 int *errp);
1735 extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
1736 				  s64 nblocks, unsigned int flags);
1737 extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
1738 extern void ext4_check_blocks_bitmap(struct super_block *);
1739 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1740 						    ext4_group_t block_group,
1741 						    struct buffer_head ** bh);
1742 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1743 struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1744 				      ext4_group_t block_group);
1745 extern unsigned ext4_init_block_bitmap(struct super_block *sb,
1746 				       struct buffer_head *bh,
1747 				       ext4_group_t group,
1748 				       struct ext4_group_desc *desc);
1749 #define ext4_free_blocks_after_init(sb, group, desc)			\
1750 		ext4_init_block_bitmap(sb, NULL, group, desc)
1751 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1752 
1753 /* dir.c */
1754 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1755 				  struct file *,
1756 				  struct ext4_dir_entry_2 *,
1757 				  struct buffer_head *, unsigned int);
1758 #define ext4_check_dir_entry(dir, filp, de, bh, offset)			\
1759 	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1760 					(de), (bh), (offset)))
1761 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1762 				    __u32 minor_hash,
1763 				    struct ext4_dir_entry_2 *dirent);
1764 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1765 
1766 /* fsync.c */
1767 extern int ext4_sync_file(struct file *, int);
1768 extern int ext4_flush_completed_IO(struct inode *);
1769 
1770 /* hash.c */
1771 extern int ext4fs_dirhash(const char *name, int len, struct
1772 			  dx_hash_info *hinfo);
1773 
1774 /* ialloc.c */
1775 extern struct inode *ext4_new_inode(handle_t *, struct inode *, int,
1776 				    const struct qstr *qstr, __u32 goal);
1777 extern void ext4_free_inode(handle_t *, struct inode *);
1778 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1779 extern unsigned long ext4_count_free_inodes(struct super_block *);
1780 extern unsigned long ext4_count_dirs(struct super_block *);
1781 extern void ext4_check_inodes_bitmap(struct super_block *);
1782 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1783 extern int ext4_init_inode_table(struct super_block *sb,
1784 				 ext4_group_t group, int barrier);
1785 
1786 /* mballoc.c */
1787 extern long ext4_mb_stats;
1788 extern long ext4_mb_max_to_scan;
1789 extern int ext4_mb_init(struct super_block *, int);
1790 extern int ext4_mb_release(struct super_block *);
1791 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1792 				struct ext4_allocation_request *, int *);
1793 extern int ext4_mb_reserve_blocks(struct super_block *, int);
1794 extern void ext4_discard_preallocations(struct inode *);
1795 extern int __init ext4_init_mballoc(void);
1796 extern void ext4_exit_mballoc(void);
1797 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1798 			     struct buffer_head *bh, ext4_fsblk_t block,
1799 			     unsigned long count, int flags);
1800 extern int ext4_mb_add_groupinfo(struct super_block *sb,
1801 		ext4_group_t i, struct ext4_group_desc *desc);
1802 extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
1803 				ext4_fsblk_t block, unsigned long count);
1804 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
1805 
1806 /* inode.c */
1807 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1808 						ext4_lblk_t, int, int *);
1809 struct buffer_head *ext4_bread(handle_t *, struct inode *,
1810 						ext4_lblk_t, int, int *);
1811 int ext4_get_block(struct inode *inode, sector_t iblock,
1812 				struct buffer_head *bh_result, int create);
1813 
1814 extern struct inode *ext4_iget(struct super_block *, unsigned long);
1815 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
1816 extern int  ext4_setattr(struct dentry *, struct iattr *);
1817 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1818 				struct kstat *stat);
1819 extern void ext4_evict_inode(struct inode *);
1820 extern void ext4_clear_inode(struct inode *);
1821 extern int  ext4_sync_inode(handle_t *, struct inode *);
1822 extern void ext4_dirty_inode(struct inode *, int);
1823 extern int ext4_change_inode_journal_flag(struct inode *, int);
1824 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1825 extern int ext4_can_truncate(struct inode *inode);
1826 extern void ext4_truncate(struct inode *);
1827 extern int ext4_punch_hole(struct file *file, loff_t offset, loff_t length);
1828 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
1829 extern void ext4_set_inode_flags(struct inode *);
1830 extern void ext4_get_inode_flags(struct ext4_inode_info *);
1831 extern int ext4_alloc_da_blocks(struct inode *inode);
1832 extern void ext4_set_aops(struct inode *inode);
1833 extern int ext4_writepage_trans_blocks(struct inode *);
1834 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1835 extern int ext4_block_truncate_page(handle_t *handle,
1836 		struct address_space *mapping, loff_t from);
1837 extern int ext4_block_zero_page_range(handle_t *handle,
1838 		struct address_space *mapping, loff_t from, loff_t length);
1839 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1840 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
1841 extern void ext4_da_update_reserve_space(struct inode *inode,
1842 					int used, int quota_claim);
1843 
1844 /* indirect.c */
1845 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
1846 				struct ext4_map_blocks *map, int flags);
1847 extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
1848 				const struct iovec *iov, loff_t offset,
1849 				unsigned long nr_segs);
1850 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
1851 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk);
1852 extern void ext4_ind_truncate(struct inode *inode);
1853 
1854 /* ioctl.c */
1855 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1856 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1857 
1858 /* migrate.c */
1859 extern int ext4_ext_migrate(struct inode *);
1860 
1861 /* namei.c */
1862 extern int ext4_orphan_add(handle_t *, struct inode *);
1863 extern int ext4_orphan_del(handle_t *, struct inode *);
1864 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1865 				__u32 start_minor_hash, __u32 *next_hash);
1866 
1867 /* resize.c */
1868 extern int ext4_group_add(struct super_block *sb,
1869 				struct ext4_new_group_data *input);
1870 extern int ext4_group_extend(struct super_block *sb,
1871 				struct ext4_super_block *es,
1872 				ext4_fsblk_t n_blocks_count);
1873 
1874 /* super.c */
1875 extern void __ext4_error(struct super_block *, const char *, unsigned int,
1876 			 const char *, ...)
1877 	__attribute__ ((format (printf, 4, 5)));
1878 #define ext4_error(sb, message...)	__ext4_error(sb, __func__,	\
1879 						     __LINE__, ## message)
1880 extern void ext4_error_inode(struct inode *, const char *, unsigned int,
1881 			     ext4_fsblk_t, const char *, ...)
1882 	__attribute__ ((format (printf, 5, 6)));
1883 extern void ext4_error_file(struct file *, const char *, unsigned int,
1884 			    ext4_fsblk_t, const char *, ...)
1885 	__attribute__ ((format (printf, 5, 6)));
1886 extern void __ext4_std_error(struct super_block *, const char *,
1887 			     unsigned int, int);
1888 extern void __ext4_abort(struct super_block *, const char *, unsigned int,
1889 		       const char *, ...)
1890 	__attribute__ ((format (printf, 4, 5)));
1891 #define ext4_abort(sb, message...)	__ext4_abort(sb, __func__, \
1892 						       __LINE__, ## message)
1893 extern void __ext4_warning(struct super_block *, const char *, unsigned int,
1894 			  const char *, ...)
1895 	__attribute__ ((format (printf, 4, 5)));
1896 #define ext4_warning(sb, message...)	__ext4_warning(sb, __func__, \
1897 						       __LINE__, ## message)
1898 extern void ext4_msg(struct super_block *, const char *, const char *, ...)
1899 	__attribute__ ((format (printf, 3, 4)));
1900 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
1901 			   const char *, unsigned int, const char *);
1902 #define dump_mmp_msg(sb, mmp, msg)	__dump_mmp_msg(sb, mmp, __func__, \
1903 						       __LINE__, msg)
1904 extern void __ext4_grp_locked_error(const char *, unsigned int, \
1905 				    struct super_block *, ext4_group_t, \
1906 				    unsigned long, ext4_fsblk_t, \
1907 				    const char *, ...)
1908 	__attribute__ ((format (printf, 7, 8)));
1909 #define ext4_grp_locked_error(sb, grp, message...) \
1910 	__ext4_grp_locked_error(__func__, __LINE__, (sb), (grp), ## message)
1911 extern void ext4_update_dynamic_rev(struct super_block *sb);
1912 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1913 					__u32 compat);
1914 extern int ext4_update_rocompat_feature(handle_t *handle,
1915 					struct super_block *sb,	__u32 rocompat);
1916 extern int ext4_update_incompat_feature(handle_t *handle,
1917 					struct super_block *sb,	__u32 incompat);
1918 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1919 				      struct ext4_group_desc *bg);
1920 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1921 				      struct ext4_group_desc *bg);
1922 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1923 				     struct ext4_group_desc *bg);
1924 extern __u32 ext4_free_blks_count(struct super_block *sb,
1925 				struct ext4_group_desc *bg);
1926 extern __u32 ext4_free_inodes_count(struct super_block *sb,
1927 				 struct ext4_group_desc *bg);
1928 extern __u32 ext4_used_dirs_count(struct super_block *sb,
1929 				struct ext4_group_desc *bg);
1930 extern __u32 ext4_itable_unused_count(struct super_block *sb,
1931 				   struct ext4_group_desc *bg);
1932 extern void ext4_block_bitmap_set(struct super_block *sb,
1933 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1934 extern void ext4_inode_bitmap_set(struct super_block *sb,
1935 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1936 extern void ext4_inode_table_set(struct super_block *sb,
1937 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
1938 extern void ext4_free_blks_set(struct super_block *sb,
1939 			       struct ext4_group_desc *bg, __u32 count);
1940 extern void ext4_free_inodes_set(struct super_block *sb,
1941 				struct ext4_group_desc *bg, __u32 count);
1942 extern void ext4_used_dirs_set(struct super_block *sb,
1943 				struct ext4_group_desc *bg, __u32 count);
1944 extern void ext4_itable_unused_set(struct super_block *sb,
1945 				   struct ext4_group_desc *bg, __u32 count);
1946 extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
1947 				   struct ext4_group_desc *gdp);
1948 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
1949 				       struct ext4_group_desc *gdp);
1950 
1951 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
1952 {
1953 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
1954 		le32_to_cpu(es->s_blocks_count_lo);
1955 }
1956 
1957 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
1958 {
1959 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
1960 		le32_to_cpu(es->s_r_blocks_count_lo);
1961 }
1962 
1963 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
1964 {
1965 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
1966 		le32_to_cpu(es->s_free_blocks_count_lo);
1967 }
1968 
1969 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
1970 					 ext4_fsblk_t blk)
1971 {
1972 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
1973 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
1974 }
1975 
1976 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
1977 					      ext4_fsblk_t blk)
1978 {
1979 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
1980 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
1981 }
1982 
1983 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
1984 					   ext4_fsblk_t blk)
1985 {
1986 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
1987 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
1988 }
1989 
1990 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
1991 {
1992 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
1993 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
1994 			le32_to_cpu(raw_inode->i_size_lo);
1995 	else
1996 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
1997 }
1998 
1999 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2000 {
2001 	raw_inode->i_size_lo = cpu_to_le32(i_size);
2002 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2003 }
2004 
2005 static inline
2006 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2007 					    ext4_group_t group)
2008 {
2009 	 struct ext4_group_info ***grp_info;
2010 	 long indexv, indexh;
2011 	 grp_info = EXT4_SB(sb)->s_group_info;
2012 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2013 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2014 	 return grp_info[indexv][indexh];
2015 }
2016 
2017 /*
2018  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2019  * the locking protocol documented in the comments of ext4_group_add()
2020  * in resize.c
2021  */
2022 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2023 {
2024 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
2025 
2026 	smp_rmb();
2027 	return ngroups;
2028 }
2029 
2030 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2031 					     ext4_group_t block_group)
2032 {
2033 	return block_group >> sbi->s_log_groups_per_flex;
2034 }
2035 
2036 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2037 {
2038 	return 1 << sbi->s_log_groups_per_flex;
2039 }
2040 
2041 #define ext4_std_error(sb, errno)				\
2042 do {								\
2043 	if ((errno))						\
2044 		__ext4_std_error((sb), __func__, __LINE__, (errno));	\
2045 } while (0)
2046 
2047 #ifdef CONFIG_SMP
2048 /* Each CPU can accumulate percpu_counter_batch blocks in their local
2049  * counters. So we need to make sure we have free blocks more
2050  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2051  */
2052 #define EXT4_FREEBLOCKS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2053 #else
2054 #define EXT4_FREEBLOCKS_WATERMARK 0
2055 #endif
2056 
2057 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2058 {
2059 	/*
2060 	 * XXX: replace with spinlock if seen contended -bzzz
2061 	 */
2062 	down_write(&EXT4_I(inode)->i_data_sem);
2063 	if (newsize > EXT4_I(inode)->i_disksize)
2064 		EXT4_I(inode)->i_disksize = newsize;
2065 	up_write(&EXT4_I(inode)->i_data_sem);
2066 	return ;
2067 }
2068 
2069 struct ext4_group_info {
2070 	unsigned long   bb_state;
2071 	struct rb_root  bb_free_root;
2072 	ext4_grpblk_t	bb_first_free;	/* first free block */
2073 	ext4_grpblk_t	bb_free;	/* total free blocks */
2074 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
2075 	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
2076 	struct          list_head bb_prealloc_list;
2077 #ifdef DOUBLE_CHECK
2078 	void            *bb_bitmap;
2079 #endif
2080 	struct rw_semaphore alloc_sem;
2081 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
2082 					 * regions, index is order.
2083 					 * bb_counters[3] = 5 means
2084 					 * 5 free 8-block regions. */
2085 };
2086 
2087 #define EXT4_GROUP_INFO_NEED_INIT_BIT		0
2088 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT		1
2089 
2090 #define EXT4_MB_GRP_NEED_INIT(grp)	\
2091 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2092 
2093 #define EXT4_MB_GRP_WAS_TRIMMED(grp)	\
2094 	(test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2095 #define EXT4_MB_GRP_SET_TRIMMED(grp)	\
2096 	(set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2097 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)	\
2098 	(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2099 
2100 #define EXT4_MAX_CONTENTION		8
2101 #define EXT4_CONTENTION_THRESHOLD	2
2102 
2103 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2104 					      ext4_group_t group)
2105 {
2106 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2107 }
2108 
2109 /*
2110  * Returns true if the filesystem is busy enough that attempts to
2111  * access the block group locks has run into contention.
2112  */
2113 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2114 {
2115 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2116 }
2117 
2118 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2119 {
2120 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2121 	if (spin_trylock(lock))
2122 		/*
2123 		 * We're able to grab the lock right away, so drop the
2124 		 * lock contention counter.
2125 		 */
2126 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2127 	else {
2128 		/*
2129 		 * The lock is busy, so bump the contention counter,
2130 		 * and then wait on the spin lock.
2131 		 */
2132 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2133 				  EXT4_MAX_CONTENTION);
2134 		spin_lock(lock);
2135 	}
2136 }
2137 
2138 static inline void ext4_unlock_group(struct super_block *sb,
2139 					ext4_group_t group)
2140 {
2141 	spin_unlock(ext4_group_lock_ptr(sb, group));
2142 }
2143 
2144 static inline void ext4_mark_super_dirty(struct super_block *sb)
2145 {
2146 	if (EXT4_SB(sb)->s_journal == NULL)
2147 		sb->s_dirt =1;
2148 }
2149 
2150 /*
2151  * Block validity checking
2152  */
2153 #define ext4_check_indirect_blockref(inode, bh)				\
2154 	ext4_check_blockref(__func__, __LINE__, inode,			\
2155 			    (__le32 *)(bh)->b_data,			\
2156 			    EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2157 
2158 #define ext4_ind_check_inode(inode)					\
2159 	ext4_check_blockref(__func__, __LINE__, inode,			\
2160 			    EXT4_I(inode)->i_data,			\
2161 			    EXT4_NDIR_BLOCKS)
2162 
2163 /*
2164  * Inodes and files operations
2165  */
2166 
2167 /* dir.c */
2168 extern const struct file_operations ext4_dir_operations;
2169 
2170 /* file.c */
2171 extern const struct inode_operations ext4_file_inode_operations;
2172 extern const struct file_operations ext4_file_operations;
2173 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2174 
2175 /* namei.c */
2176 extern const struct inode_operations ext4_dir_inode_operations;
2177 extern const struct inode_operations ext4_special_inode_operations;
2178 extern struct dentry *ext4_get_parent(struct dentry *child);
2179 
2180 /* symlink.c */
2181 extern const struct inode_operations ext4_symlink_inode_operations;
2182 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2183 
2184 /* block_validity */
2185 extern void ext4_release_system_zone(struct super_block *sb);
2186 extern int ext4_setup_system_zone(struct super_block *sb);
2187 extern int __init ext4_init_system_zone(void);
2188 extern void ext4_exit_system_zone(void);
2189 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2190 				 ext4_fsblk_t start_blk,
2191 				 unsigned int count);
2192 extern int ext4_check_blockref(const char *, unsigned int,
2193 			       struct inode *, __le32 *, unsigned int);
2194 
2195 /* extents.c */
2196 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2197 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2198 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
2199 				       int chunk);
2200 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2201 			       struct ext4_map_blocks *map, int flags);
2202 extern void ext4_ext_truncate(struct inode *);
2203 extern int ext4_ext_punch_hole(struct file *file, loff_t offset,
2204 				loff_t length);
2205 extern void ext4_ext_init(struct super_block *);
2206 extern void ext4_ext_release(struct super_block *);
2207 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2208 			  loff_t len);
2209 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
2210 			  ssize_t len);
2211 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2212 			   struct ext4_map_blocks *map, int flags);
2213 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2214 			__u64 start, __u64 len);
2215 /* move_extent.c */
2216 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2217 			     __u64 start_orig, __u64 start_donor,
2218 			     __u64 len, __u64 *moved_len);
2219 
2220 /* page-io.c */
2221 extern int __init ext4_init_pageio(void);
2222 extern void ext4_exit_pageio(void);
2223 extern void ext4_ioend_wait(struct inode *);
2224 extern void ext4_free_io_end(ext4_io_end_t *io);
2225 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2226 extern int ext4_end_io_nolock(ext4_io_end_t *io);
2227 extern void ext4_io_submit(struct ext4_io_submit *io);
2228 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2229 			       struct page *page,
2230 			       int len,
2231 			       struct writeback_control *wbc);
2232 
2233 /* mmp.c */
2234 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2235 
2236 /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
2237 enum ext4_state_bits {
2238 	BH_Uninit	/* blocks are allocated but uninitialized on disk */
2239 	  = BH_JBDPrivateStart,
2240 };
2241 
2242 BUFFER_FNS(Uninit, uninit)
2243 TAS_BUFFER_FNS(Uninit, uninit)
2244 
2245 /*
2246  * Add new method to test wether block and inode bitmaps are properly
2247  * initialized. With uninit_bg reading the block from disk is not enough
2248  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2249  */
2250 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2251 
2252 static inline int bitmap_uptodate(struct buffer_head *bh)
2253 {
2254 	return (buffer_uptodate(bh) &&
2255 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2256 }
2257 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2258 {
2259 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2260 }
2261 
2262 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
2263 
2264 /* For ioend & aio unwritten conversion wait queues */
2265 #define EXT4_WQ_HASH_SZ		37
2266 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2267 					    EXT4_WQ_HASH_SZ])
2268 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2269 					     EXT4_WQ_HASH_SZ])
2270 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2271 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2272 
2273 #define EXT4_RESIZING	0
2274 extern int ext4_resize_begin(struct super_block *sb);
2275 extern void ext4_resize_end(struct super_block *sb);
2276 
2277 #endif	/* __KERNEL__ */
2278 
2279 #endif	/* _EXT4_H */
2280