xref: /openbmc/linux/fs/ext4/ext4.h (revision e35fd660)
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 
33 /*
34  * The fourth extended filesystem constants/structures
35  */
36 
37 /*
38  * Define EXT4FS_DEBUG to produce debug messages
39  */
40 #undef EXT4FS_DEBUG
41 
42 /*
43  * Debug code
44  */
45 #ifdef EXT4FS_DEBUG
46 #define ext4_debug(f, a...)						\
47 	do {								\
48 		printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",	\
49 			__FILE__, __LINE__, __func__);			\
50 		printk(KERN_DEBUG f, ## a);				\
51 	} while (0)
52 #else
53 #define ext4_debug(f, a...)	do {} while (0)
54 #endif
55 
56 #define EXT4_ERROR_INODE(inode, fmt, a...) \
57 	ext4_error_inode(__func__, (inode), (fmt), ## a);
58 
59 #define EXT4_ERROR_FILE(file, fmt, a...)	\
60 	ext4_error_file(__func__, (file), (fmt), ## a);
61 
62 /* data type for block offset of block group */
63 typedef int ext4_grpblk_t;
64 
65 /* data type for filesystem-wide blocks number */
66 typedef unsigned long long ext4_fsblk_t;
67 
68 /* data type for file logical block number */
69 typedef __u32 ext4_lblk_t;
70 
71 /* data type for block group number */
72 typedef unsigned int ext4_group_t;
73 
74 /*
75  * Flags used in mballoc's allocation_context flags field.
76  *
77  * Also used to show what's going on for debugging purposes when the
78  * flag field is exported via the traceport interface
79  */
80 
81 /* prefer goal again. length */
82 #define EXT4_MB_HINT_MERGE		0x0001
83 /* blocks already reserved */
84 #define EXT4_MB_HINT_RESERVED		0x0002
85 /* metadata is being allocated */
86 #define EXT4_MB_HINT_METADATA		0x0004
87 /* first blocks in the file */
88 #define EXT4_MB_HINT_FIRST		0x0008
89 /* search for the best chunk */
90 #define EXT4_MB_HINT_BEST		0x0010
91 /* data is being allocated */
92 #define EXT4_MB_HINT_DATA		0x0020
93 /* don't preallocate (for tails) */
94 #define EXT4_MB_HINT_NOPREALLOC		0x0040
95 /* allocate for locality group */
96 #define EXT4_MB_HINT_GROUP_ALLOC	0x0080
97 /* allocate goal blocks or none */
98 #define EXT4_MB_HINT_GOAL_ONLY		0x0100
99 /* goal is meaningful */
100 #define EXT4_MB_HINT_TRY_GOAL		0x0200
101 /* blocks already pre-reserved by delayed allocation */
102 #define EXT4_MB_DELALLOC_RESERVED	0x0400
103 /* We are doing stream allocation */
104 #define EXT4_MB_STREAM_ALLOC		0x0800
105 
106 
107 struct ext4_allocation_request {
108 	/* target inode for block we're allocating */
109 	struct inode *inode;
110 	/* how many blocks we want to allocate */
111 	unsigned int len;
112 	/* logical block in target inode */
113 	ext4_lblk_t logical;
114 	/* the closest logical allocated block to the left */
115 	ext4_lblk_t lleft;
116 	/* the closest logical allocated block to the right */
117 	ext4_lblk_t lright;
118 	/* phys. target (a hint) */
119 	ext4_fsblk_t goal;
120 	/* phys. block for the closest logical allocated block to the left */
121 	ext4_fsblk_t pleft;
122 	/* phys. block for the closest logical allocated block to the right */
123 	ext4_fsblk_t pright;
124 	/* flags. see above EXT4_MB_HINT_* */
125 	unsigned int flags;
126 };
127 
128 /*
129  * Logical to physical block mapping, used by ext4_map_blocks()
130  *
131  * This structure is used to pass requests into ext4_map_blocks() as
132  * well as to store the information returned by ext4_map_blocks().  It
133  * takes less room on the stack than a struct buffer_head.
134  */
135 #define EXT4_MAP_NEW		(1 << BH_New)
136 #define EXT4_MAP_MAPPED		(1 << BH_Mapped)
137 #define EXT4_MAP_UNWRITTEN	(1 << BH_Unwritten)
138 #define EXT4_MAP_BOUNDARY	(1 << BH_Boundary)
139 #define EXT4_MAP_UNINIT		(1 << BH_Uninit)
140 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
141 				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
142 				 EXT4_MAP_UNINIT)
143 
144 struct ext4_map_blocks {
145 	ext4_fsblk_t m_pblk;
146 	ext4_lblk_t m_lblk;
147 	unsigned int m_len;
148 	unsigned int m_flags;
149 };
150 
151 /*
152  * For delayed allocation tracking
153  */
154 struct mpage_da_data {
155 	struct inode *inode;
156 	sector_t b_blocknr;		/* start block number of extent */
157 	size_t b_size;			/* size of extent */
158 	unsigned long b_state;		/* state of the extent */
159 	unsigned long first_page, next_page;	/* extent of pages */
160 	struct writeback_control *wbc;
161 	int io_done;
162 	int pages_written;
163 	int retval;
164 };
165 #define	EXT4_IO_UNWRITTEN	0x1
166 typedef struct ext4_io_end {
167 	struct list_head	list;		/* per-file finished AIO list */
168 	struct inode		*inode;		/* file being written to */
169 	unsigned int		flag;		/* unwritten or not */
170 	struct page		*page;		/* page struct for buffer write */
171 	loff_t			offset;		/* offset in the file */
172 	ssize_t			size;		/* size of the extent */
173 	struct work_struct	work;		/* data work queue */
174 } ext4_io_end_t;
175 
176 /*
177  * Special inodes numbers
178  */
179 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
180 #define EXT4_ROOT_INO		 2	/* Root inode */
181 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
182 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
183 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
184 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
185 
186 /* First non-reserved inode for old ext4 filesystems */
187 #define EXT4_GOOD_OLD_FIRST_INO	11
188 
189 /*
190  * Maximal count of links to a file
191  */
192 #define EXT4_LINK_MAX		65000
193 
194 /*
195  * Macro-instructions used to manage several block sizes
196  */
197 #define EXT4_MIN_BLOCK_SIZE		1024
198 #define	EXT4_MAX_BLOCK_SIZE		65536
199 #define EXT4_MIN_BLOCK_LOG_SIZE		10
200 #ifdef __KERNEL__
201 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
202 #else
203 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
204 #endif
205 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
206 #ifdef __KERNEL__
207 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
208 #else
209 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
210 #endif
211 #ifdef __KERNEL__
212 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
213 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
214 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
215 #else
216 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
217 				 EXT4_GOOD_OLD_INODE_SIZE : \
218 				 (s)->s_inode_size)
219 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
220 				 EXT4_GOOD_OLD_FIRST_INO : \
221 				 (s)->s_first_ino)
222 #endif
223 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
224 
225 /*
226  * Structure of a blocks group descriptor
227  */
228 struct ext4_group_desc
229 {
230 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
231 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
232 	__le32	bg_inode_table_lo;	/* Inodes table block */
233 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
234 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
235 	__le16	bg_used_dirs_count_lo;	/* Directories count */
236 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
237 	__u32	bg_reserved[2];		/* Likely block/inode bitmap checksum */
238 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
239 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
240 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
241 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
242 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
243 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
244 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
245 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
246 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
247 	__u32	bg_reserved2[3];
248 };
249 
250 /*
251  * Structure of a flex block group info
252  */
253 
254 struct flex_groups {
255 	atomic_t free_inodes;
256 	atomic_t free_blocks;
257 	atomic_t used_dirs;
258 };
259 
260 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
261 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
262 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
263 
264 /*
265  * Macro-instructions used to manage group descriptors
266  */
267 #define EXT4_MIN_DESC_SIZE		32
268 #define EXT4_MIN_DESC_SIZE_64BIT	64
269 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
270 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
271 #ifdef __KERNEL__
272 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
273 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
274 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
275 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
276 #else
277 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
278 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
279 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
280 #endif
281 
282 /*
283  * Constants relative to the data blocks
284  */
285 #define	EXT4_NDIR_BLOCKS		12
286 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
287 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
288 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
289 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
290 
291 /*
292  * Inode flags
293  */
294 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
295 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
296 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
297 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
298 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
299 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
300 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
301 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
302 /* Reserved for compression usage... */
303 #define EXT4_DIRTY_FL			0x00000100
304 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
305 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
306 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
307 /* End compression flags --- maybe not all used */
308 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
309 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
310 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
311 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
312 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
313 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
314 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
315 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
316 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
317 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
318 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
319 
320 #define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
321 #define EXT4_FL_USER_MODIFIABLE		0x004B80FF /* User modifiable flags */
322 
323 /* Flags that should be inherited by new inodes from their parent. */
324 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
325 			   EXT4_SYNC_FL | EXT4_IMMUTABLE_FL | EXT4_APPEND_FL |\
326 			   EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
327 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
328 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
329 
330 /* Flags that are appropriate for regular files (all but dir-specific ones). */
331 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
332 
333 /* Flags that are appropriate for non-directories/regular files. */
334 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
335 
336 /* Mask out flags that are inappropriate for the given type of inode. */
337 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
338 {
339 	if (S_ISDIR(mode))
340 		return flags;
341 	else if (S_ISREG(mode))
342 		return flags & EXT4_REG_FLMASK;
343 	else
344 		return flags & EXT4_OTHER_FLMASK;
345 }
346 
347 /* Used to pass group descriptor data when online resize is done */
348 struct ext4_new_group_input {
349 	__u32 group;		/* Group number for this data */
350 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
351 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
352 	__u64 inode_table;	/* Absolute block number of inode table start */
353 	__u32 blocks_count;	/* Total number of blocks in this group */
354 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
355 	__u16 unused;
356 };
357 
358 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
359 struct ext4_new_group_data {
360 	__u32 group;
361 	__u64 block_bitmap;
362 	__u64 inode_bitmap;
363 	__u64 inode_table;
364 	__u32 blocks_count;
365 	__u16 reserved_blocks;
366 	__u16 unused;
367 	__u32 free_blocks_count;
368 };
369 
370 /*
371  * Flags used by ext4_get_blocks()
372  */
373 	/* Allocate any needed blocks and/or convert an unitialized
374 	   extent to be an initialized ext4 */
375 #define EXT4_GET_BLOCKS_CREATE			0x0001
376 	/* Request the creation of an unitialized extent */
377 #define EXT4_GET_BLOCKS_UNINIT_EXT		0x0002
378 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\
379 						 EXT4_GET_BLOCKS_CREATE)
380 	/* Caller is from the delayed allocation writeout path,
381 	   so set the magic i_delalloc_reserve_flag after taking the
382 	   inode allocation semaphore for */
383 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
384 	/* caller is from the direct IO path, request to creation of an
385 	unitialized extents if not allocated, split the uninitialized
386 	extent if blocks has been preallocated already*/
387 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
388 #define EXT4_GET_BLOCKS_CONVERT			0x0010
389 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
390 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
391 	/* Convert extent to initialized after IO complete */
392 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
393 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
394 
395 /*
396  * Flags used by ext4_free_blocks
397  */
398 #define EXT4_FREE_BLOCKS_METADATA	0x0001
399 #define EXT4_FREE_BLOCKS_FORGET		0x0002
400 #define EXT4_FREE_BLOCKS_VALIDATED	0x0004
401 
402 /*
403  * ioctl commands
404  */
405 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
406 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
407 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
408 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
409 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
410 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
411 #ifdef CONFIG_JBD2_DEBUG
412 #define EXT4_IOC_WAIT_FOR_READONLY	_IOR('f', 99, long)
413 #endif
414 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
415 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
416 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
417 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
418 #define EXT4_IOC_MIGRATE		_IO('f', 9)
419  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
420  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
421 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
422 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
423 
424 /*
425  * ioctl commands in 32 bit emulation
426  */
427 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
428 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
429 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
430 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
431 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
432 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
433 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
434 #ifdef CONFIG_JBD2_DEBUG
435 #define EXT4_IOC32_WAIT_FOR_READONLY	_IOR('f', 99, int)
436 #endif
437 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
438 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
439 
440 
441 /*
442  *  Mount options
443  */
444 struct ext4_mount_options {
445 	unsigned long s_mount_opt;
446 	uid_t s_resuid;
447 	gid_t s_resgid;
448 	unsigned long s_commit_interval;
449 	u32 s_min_batch_time, s_max_batch_time;
450 #ifdef CONFIG_QUOTA
451 	int s_jquota_fmt;
452 	char *s_qf_names[MAXQUOTAS];
453 #endif
454 };
455 
456 /* Max physical block we can addres w/o extents */
457 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
458 
459 /*
460  * Structure of an inode on the disk
461  */
462 struct ext4_inode {
463 	__le16	i_mode;		/* File mode */
464 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
465 	__le32	i_size_lo;	/* Size in bytes */
466 	__le32	i_atime;	/* Access time */
467 	__le32	i_ctime;	/* Inode Change time */
468 	__le32	i_mtime;	/* Modification time */
469 	__le32	i_dtime;	/* Deletion Time */
470 	__le16	i_gid;		/* Low 16 bits of Group Id */
471 	__le16	i_links_count;	/* Links count */
472 	__le32	i_blocks_lo;	/* Blocks count */
473 	__le32	i_flags;	/* File flags */
474 	union {
475 		struct {
476 			__le32  l_i_version;
477 		} linux1;
478 		struct {
479 			__u32  h_i_translator;
480 		} hurd1;
481 		struct {
482 			__u32  m_i_reserved1;
483 		} masix1;
484 	} osd1;				/* OS dependent 1 */
485 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
486 	__le32	i_generation;	/* File version (for NFS) */
487 	__le32	i_file_acl_lo;	/* File ACL */
488 	__le32	i_size_high;
489 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
490 	union {
491 		struct {
492 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
493 			__le16	l_i_file_acl_high;
494 			__le16	l_i_uid_high;	/* these 2 fields */
495 			__le16	l_i_gid_high;	/* were reserved2[0] */
496 			__u32	l_i_reserved2;
497 		} linux2;
498 		struct {
499 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
500 			__u16	h_i_mode_high;
501 			__u16	h_i_uid_high;
502 			__u16	h_i_gid_high;
503 			__u32	h_i_author;
504 		} hurd2;
505 		struct {
506 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
507 			__le16	m_i_file_acl_high;
508 			__u32	m_i_reserved2[2];
509 		} masix2;
510 	} osd2;				/* OS dependent 2 */
511 	__le16	i_extra_isize;
512 	__le16	i_pad1;
513 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
514 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
515 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
516 	__le32  i_crtime;       /* File Creation time */
517 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
518 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
519 };
520 
521 struct move_extent {
522 	__u32 reserved;		/* should be zero */
523 	__u32 donor_fd;		/* donor file descriptor */
524 	__u64 orig_start;	/* logical start offset in block for orig */
525 	__u64 donor_start;	/* logical start offset in block for donor */
526 	__u64 len;		/* block length to be moved */
527 	__u64 moved_len;	/* moved block length */
528 };
529 
530 #define EXT4_EPOCH_BITS 2
531 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
532 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
533 
534 /*
535  * Extended fields will fit into an inode if the filesystem was formatted
536  * with large inodes (-I 256 or larger) and there are not currently any EAs
537  * consuming all of the available space. For new inodes we always reserve
538  * enough space for the kernel's known extended fields, but for inodes
539  * created with an old kernel this might not have been the case. None of
540  * the extended inode fields is critical for correct filesystem operation.
541  * This macro checks if a certain field fits in the inode. Note that
542  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
543  */
544 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
545 	((offsetof(typeof(*ext4_inode), field) +	\
546 	  sizeof((ext4_inode)->field))			\
547 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
548 	    (einode)->i_extra_isize))			\
549 
550 static inline __le32 ext4_encode_extra_time(struct timespec *time)
551 {
552        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
553 			   (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
554                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
555 }
556 
557 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
558 {
559        if (sizeof(time->tv_sec) > 4)
560 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
561 			       << 32;
562        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
563 }
564 
565 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
566 do {									       \
567 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
568 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
569 		(raw_inode)->xtime ## _extra =				       \
570 				ext4_encode_extra_time(&(inode)->xtime);       \
571 } while (0)
572 
573 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
574 do {									       \
575 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
576 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
577 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
578 		(raw_inode)->xtime ## _extra =				       \
579 				ext4_encode_extra_time(&(einode)->xtime);      \
580 } while (0)
581 
582 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
583 do {									       \
584 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
585 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
586 		ext4_decode_extra_time(&(inode)->xtime,			       \
587 				       raw_inode->xtime ## _extra);	       \
588 } while (0)
589 
590 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
591 do {									       \
592 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
593 		(einode)->xtime.tv_sec = 				       \
594 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
595 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
596 		ext4_decode_extra_time(&(einode)->xtime,		       \
597 				       raw_inode->xtime ## _extra);	       \
598 } while (0)
599 
600 #define i_disk_version osd1.linux1.l_i_version
601 
602 #if defined(__KERNEL__) || defined(__linux__)
603 #define i_reserved1	osd1.linux1.l_i_reserved1
604 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
605 #define i_blocks_high	osd2.linux2.l_i_blocks_high
606 #define i_uid_low	i_uid
607 #define i_gid_low	i_gid
608 #define i_uid_high	osd2.linux2.l_i_uid_high
609 #define i_gid_high	osd2.linux2.l_i_gid_high
610 #define i_reserved2	osd2.linux2.l_i_reserved2
611 
612 #elif defined(__GNU__)
613 
614 #define i_translator	osd1.hurd1.h_i_translator
615 #define i_uid_high	osd2.hurd2.h_i_uid_high
616 #define i_gid_high	osd2.hurd2.h_i_gid_high
617 #define i_author	osd2.hurd2.h_i_author
618 
619 #elif defined(__masix__)
620 
621 #define i_reserved1	osd1.masix1.m_i_reserved1
622 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
623 #define i_reserved2	osd2.masix2.m_i_reserved2
624 
625 #endif /* defined(__KERNEL__) || defined(__linux__) */
626 
627 /*
628  * storage for cached extent
629  */
630 struct ext4_ext_cache {
631 	ext4_fsblk_t	ec_start;
632 	ext4_lblk_t	ec_block;
633 	__u32		ec_len; /* must be 32bit to return holes */
634 	__u32		ec_type;
635 };
636 
637 /*
638  * fourth extended file system inode data in memory
639  */
640 struct ext4_inode_info {
641 	__le32	i_data[15];	/* unconverted */
642 	__u32	i_flags;
643 	ext4_fsblk_t	i_file_acl;
644 	__u32	i_dtime;
645 
646 	/*
647 	 * i_block_group is the number of the block group which contains
648 	 * this file's inode.  Constant across the lifetime of the inode,
649 	 * it is ued for making block allocation decisions - we try to
650 	 * place a file's data blocks near its inode block, and new inodes
651 	 * near to their parent directory's inode.
652 	 */
653 	ext4_group_t	i_block_group;
654 	unsigned long	i_state_flags;		/* Dynamic state flags */
655 
656 	ext4_lblk_t		i_dir_start_lookup;
657 #ifdef CONFIG_EXT4_FS_XATTR
658 	/*
659 	 * Extended attributes can be read independently of the main file
660 	 * data. Taking i_mutex even when reading would cause contention
661 	 * between readers of EAs and writers of regular file data, so
662 	 * instead we synchronize on xattr_sem when reading or changing
663 	 * EAs.
664 	 */
665 	struct rw_semaphore xattr_sem;
666 #endif
667 
668 	struct list_head i_orphan;	/* unlinked but open inodes */
669 
670 	/*
671 	 * i_disksize keeps track of what the inode size is ON DISK, not
672 	 * in memory.  During truncate, i_size is set to the new size by
673 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
674 	 * set i_disksize to 0 until the truncate is actually under way.
675 	 *
676 	 * The intent is that i_disksize always represents the blocks which
677 	 * are used by this file.  This allows recovery to restart truncate
678 	 * on orphans if we crash during truncate.  We actually write i_disksize
679 	 * into the on-disk inode when writing inodes out, instead of i_size.
680 	 *
681 	 * The only time when i_disksize and i_size may be different is when
682 	 * a truncate is in progress.  The only things which change i_disksize
683 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
684 	 */
685 	loff_t	i_disksize;
686 
687 	/*
688 	 * i_data_sem is for serialising ext4_truncate() against
689 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
690 	 * data tree are chopped off during truncate. We can't do that in
691 	 * ext4 because whenever we perform intermediate commits during
692 	 * truncate, the inode and all the metadata blocks *must* be in a
693 	 * consistent state which allows truncation of the orphans to restart
694 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
695 	 * by other means, so we have i_data_sem.
696 	 */
697 	struct rw_semaphore i_data_sem;
698 	struct inode vfs_inode;
699 	struct jbd2_inode jinode;
700 
701 	struct ext4_ext_cache i_cached_extent;
702 	/*
703 	 * File creation time. Its function is same as that of
704 	 * struct timespec i_{a,c,m}time in the generic inode.
705 	 */
706 	struct timespec i_crtime;
707 
708 	/* mballoc */
709 	struct list_head i_prealloc_list;
710 	spinlock_t i_prealloc_lock;
711 
712 	/* ialloc */
713 	ext4_group_t	i_last_alloc_group;
714 
715 	/* allocation reservation info for delalloc */
716 	unsigned int i_reserved_data_blocks;
717 	unsigned int i_reserved_meta_blocks;
718 	unsigned int i_allocated_meta_blocks;
719 	unsigned short i_delalloc_reserved_flag;
720 	sector_t i_da_metadata_calc_last_lblock;
721 	int i_da_metadata_calc_len;
722 
723 	/* on-disk additional length */
724 	__u16 i_extra_isize;
725 
726 	spinlock_t i_block_reservation_lock;
727 #ifdef CONFIG_QUOTA
728 	/* quota space reservation, managed internally by quota code */
729 	qsize_t i_reserved_quota;
730 #endif
731 
732 	/* completed IOs that might need unwritten extents handling */
733 	struct list_head i_completed_io_list;
734 	spinlock_t i_completed_io_lock;
735 	/* current io_end structure for async DIO write*/
736 	ext4_io_end_t *cur_aio_dio;
737 
738 	/*
739 	 * Transactions that contain inode's metadata needed to complete
740 	 * fsync and fdatasync, respectively.
741 	 */
742 	tid_t i_sync_tid;
743 	tid_t i_datasync_tid;
744 };
745 
746 /*
747  * File system states
748  */
749 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
750 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
751 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
752 
753 /*
754  * Misc. filesystem flags
755  */
756 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
757 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
758 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
759 
760 /*
761  * Mount flags
762  */
763 #define EXT4_MOUNT_OLDALLOC		0x00002  /* Don't use the new Orlov allocator */
764 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
765 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
766 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
767 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
768 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
769 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
770 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
771 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
772 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
773 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
774 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
775 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
776 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
777 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
778 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
779 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
780 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
781 #define EXT4_MOUNT_NOBH			0x40000 /* No bufferheads */
782 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
783 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
784 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
785 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
786 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
787 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
788 #define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
789 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
790 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
791 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
792 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
793 
794 #define clear_opt(o, opt)		o &= ~EXT4_MOUNT_##opt
795 #define set_opt(o, opt)			o |= EXT4_MOUNT_##opt
796 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
797 					 EXT4_MOUNT_##opt)
798 
799 #define ext4_set_bit			ext2_set_bit
800 #define ext4_set_bit_atomic		ext2_set_bit_atomic
801 #define ext4_clear_bit			ext2_clear_bit
802 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
803 #define ext4_test_bit			ext2_test_bit
804 #define ext4_find_first_zero_bit	ext2_find_first_zero_bit
805 #define ext4_find_next_zero_bit		ext2_find_next_zero_bit
806 #define ext4_find_next_bit		ext2_find_next_bit
807 
808 /*
809  * Maximal mount counts between two filesystem checks
810  */
811 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
812 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
813 
814 /*
815  * Behaviour when detecting errors
816  */
817 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
818 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
819 #define EXT4_ERRORS_PANIC		3	/* Panic */
820 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
821 
822 /*
823  * Structure of the super block
824  */
825 struct ext4_super_block {
826 /*00*/	__le32	s_inodes_count;		/* Inodes count */
827 	__le32	s_blocks_count_lo;	/* Blocks count */
828 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
829 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
830 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
831 	__le32	s_first_data_block;	/* First Data Block */
832 	__le32	s_log_block_size;	/* Block size */
833 	__le32	s_obso_log_frag_size;	/* Obsoleted fragment size */
834 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
835 	__le32	s_obso_frags_per_group;	/* Obsoleted fragments per group */
836 	__le32	s_inodes_per_group;	/* # Inodes per group */
837 	__le32	s_mtime;		/* Mount time */
838 /*30*/	__le32	s_wtime;		/* Write time */
839 	__le16	s_mnt_count;		/* Mount count */
840 	__le16	s_max_mnt_count;	/* Maximal mount count */
841 	__le16	s_magic;		/* Magic signature */
842 	__le16	s_state;		/* File system state */
843 	__le16	s_errors;		/* Behaviour when detecting errors */
844 	__le16	s_minor_rev_level;	/* minor revision level */
845 /*40*/	__le32	s_lastcheck;		/* time of last check */
846 	__le32	s_checkinterval;	/* max. time between checks */
847 	__le32	s_creator_os;		/* OS */
848 	__le32	s_rev_level;		/* Revision level */
849 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
850 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
851 	/*
852 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
853 	 *
854 	 * Note: the difference between the compatible feature set and
855 	 * the incompatible feature set is that if there is a bit set
856 	 * in the incompatible feature set that the kernel doesn't
857 	 * know about, it should refuse to mount the filesystem.
858 	 *
859 	 * e2fsck's requirements are more strict; if it doesn't know
860 	 * about a feature in either the compatible or incompatible
861 	 * feature set, it must abort and not try to meddle with
862 	 * things it doesn't understand...
863 	 */
864 	__le32	s_first_ino;		/* First non-reserved inode */
865 	__le16  s_inode_size;		/* size of inode structure */
866 	__le16	s_block_group_nr;	/* block group # of this superblock */
867 	__le32	s_feature_compat;	/* compatible feature set */
868 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
869 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
870 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
871 /*78*/	char	s_volume_name[16];	/* volume name */
872 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
873 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
874 	/*
875 	 * Performance hints.  Directory preallocation should only
876 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
877 	 */
878 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
879 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
880 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
881 	/*
882 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
883 	 */
884 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
885 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
886 	__le32	s_journal_dev;		/* device number of journal file */
887 	__le32	s_last_orphan;		/* start of list of inodes to delete */
888 	__le32	s_hash_seed[4];		/* HTREE hash seed */
889 	__u8	s_def_hash_version;	/* Default hash version to use */
890 	__u8	s_reserved_char_pad;
891 	__le16  s_desc_size;		/* size of group descriptor */
892 /*100*/	__le32	s_default_mount_opts;
893 	__le32	s_first_meta_bg;	/* First metablock block group */
894 	__le32	s_mkfs_time;		/* When the filesystem was created */
895 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
896 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
897 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
898 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
899 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
900 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
901 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
902 	__le32	s_flags;		/* Miscellaneous flags */
903 	__le16  s_raid_stride;		/* RAID stride */
904 	__le16  s_mmp_interval;         /* # seconds to wait in MMP checking */
905 	__le64  s_mmp_block;            /* Block for multi-mount protection */
906 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
907 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
908 	__u8	s_reserved_char_pad2;
909 	__le16  s_reserved_pad;
910 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
911 	__u32   s_reserved[160];        /* Padding to the end of the block */
912 };
913 
914 #ifdef __KERNEL__
915 
916 /*
917  * run-time mount flags
918  */
919 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
920 #define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
921 
922 /*
923  * fourth extended-fs super-block data in memory
924  */
925 struct ext4_sb_info {
926 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
927 	unsigned long s_inodes_per_block;/* Number of inodes per block */
928 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
929 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
930 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
931 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
932 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
933 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
934 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
935 	unsigned long s_overhead_last;  /* Last calculated overhead */
936 	unsigned long s_blocks_last;    /* Last seen block count */
937 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
938 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
939 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
940 	struct buffer_head **s_group_desc;
941 	unsigned int s_mount_opt;
942 	unsigned int s_mount_flags;
943 	ext4_fsblk_t s_sb_block;
944 	uid_t s_resuid;
945 	gid_t s_resgid;
946 	unsigned short s_mount_state;
947 	unsigned short s_pad;
948 	int s_addr_per_block_bits;
949 	int s_desc_per_block_bits;
950 	int s_inode_size;
951 	int s_first_ino;
952 	unsigned int s_inode_readahead_blks;
953 	unsigned int s_inode_goal;
954 	spinlock_t s_next_gen_lock;
955 	u32 s_next_generation;
956 	u32 s_hash_seed[4];
957 	int s_def_hash_version;
958 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
959 	struct percpu_counter s_freeblocks_counter;
960 	struct percpu_counter s_freeinodes_counter;
961 	struct percpu_counter s_dirs_counter;
962 	struct percpu_counter s_dirtyblocks_counter;
963 	struct blockgroup_lock *s_blockgroup_lock;
964 	struct proc_dir_entry *s_proc;
965 	struct kobject s_kobj;
966 	struct completion s_kobj_unregister;
967 
968 	/* Journaling */
969 	struct inode *s_journal_inode;
970 	struct journal_s *s_journal;
971 	struct list_head s_orphan;
972 	struct mutex s_orphan_lock;
973 	struct mutex s_resize_lock;
974 	unsigned long s_commit_interval;
975 	u32 s_max_batch_time;
976 	u32 s_min_batch_time;
977 	struct block_device *journal_bdev;
978 #ifdef CONFIG_JBD2_DEBUG
979 	struct timer_list turn_ro_timer;	/* For turning read-only (crash simulation) */
980 	wait_queue_head_t ro_wait_queue;	/* For people waiting for the fs to go read-only */
981 #endif
982 #ifdef CONFIG_QUOTA
983 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
984 	int s_jquota_fmt;			/* Format of quota to use */
985 #endif
986 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
987 	struct rb_root system_blks;
988 
989 #ifdef EXTENTS_STATS
990 	/* ext4 extents stats */
991 	unsigned long s_ext_min;
992 	unsigned long s_ext_max;
993 	unsigned long s_depth_max;
994 	spinlock_t s_ext_stats_lock;
995 	unsigned long s_ext_blocks;
996 	unsigned long s_ext_extents;
997 #endif
998 
999 	/* for buddy allocator */
1000 	struct ext4_group_info ***s_group_info;
1001 	struct inode *s_buddy_cache;
1002 	long s_blocks_reserved;
1003 	spinlock_t s_reserve_lock;
1004 	spinlock_t s_md_lock;
1005 	tid_t s_last_transaction;
1006 	unsigned short *s_mb_offsets;
1007 	unsigned int *s_mb_maxs;
1008 
1009 	/* tunables */
1010 	unsigned long s_stripe;
1011 	unsigned int s_mb_stream_request;
1012 	unsigned int s_mb_max_to_scan;
1013 	unsigned int s_mb_min_to_scan;
1014 	unsigned int s_mb_stats;
1015 	unsigned int s_mb_order2_reqs;
1016 	unsigned int s_mb_group_prealloc;
1017 	unsigned int s_max_writeback_mb_bump;
1018 	/* where last allocation was done - for stream allocation */
1019 	unsigned long s_mb_last_group;
1020 	unsigned long s_mb_last_start;
1021 
1022 	/* stats for buddy allocator */
1023 	spinlock_t s_mb_pa_lock;
1024 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1025 	atomic_t s_bal_success;	/* we found long enough chunks */
1026 	atomic_t s_bal_allocated;	/* in blocks */
1027 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1028 	atomic_t s_bal_goals;	/* goal hits */
1029 	atomic_t s_bal_breaks;	/* too long searches */
1030 	atomic_t s_bal_2orders;	/* 2^order hits */
1031 	spinlock_t s_bal_lock;
1032 	unsigned long s_mb_buddies_generated;
1033 	unsigned long long s_mb_generation_time;
1034 	atomic_t s_mb_lost_chunks;
1035 	atomic_t s_mb_preallocated;
1036 	atomic_t s_mb_discarded;
1037 	atomic_t s_lock_busy;
1038 
1039 	/* locality groups */
1040 	struct ext4_locality_group __percpu *s_locality_groups;
1041 
1042 	/* for write statistics */
1043 	unsigned long s_sectors_written_start;
1044 	u64 s_kbytes_written;
1045 
1046 	unsigned int s_log_groups_per_flex;
1047 	struct flex_groups *s_flex_groups;
1048 
1049 	/* workqueue for dio unwritten */
1050 	struct workqueue_struct *dio_unwritten_wq;
1051 };
1052 
1053 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1054 {
1055 	return sb->s_fs_info;
1056 }
1057 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1058 {
1059 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1060 }
1061 
1062 static inline struct timespec ext4_current_time(struct inode *inode)
1063 {
1064 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1065 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1066 }
1067 
1068 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1069 {
1070 	return ino == EXT4_ROOT_INO ||
1071 		ino == EXT4_JOURNAL_INO ||
1072 		ino == EXT4_RESIZE_INO ||
1073 		(ino >= EXT4_FIRST_INO(sb) &&
1074 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1075 }
1076 
1077 /*
1078  * Inode dynamic state flags
1079  */
1080 enum {
1081 	EXT4_STATE_JDATA,		/* journaled data exists */
1082 	EXT4_STATE_NEW,			/* inode is newly created */
1083 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1084 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1085 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1086 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1087 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1088 };
1089 
1090 static inline int ext4_test_inode_state(struct inode *inode, int bit)
1091 {
1092 	return test_bit(bit, &EXT4_I(inode)->i_state_flags);
1093 }
1094 
1095 static inline void ext4_set_inode_state(struct inode *inode, int bit)
1096 {
1097 	set_bit(bit, &EXT4_I(inode)->i_state_flags);
1098 }
1099 
1100 static inline void ext4_clear_inode_state(struct inode *inode, int bit)
1101 {
1102 	clear_bit(bit, &EXT4_I(inode)->i_state_flags);
1103 }
1104 #else
1105 /* Assume that user mode programs are passing in an ext4fs superblock, not
1106  * a kernel struct super_block.  This will allow us to call the feature-test
1107  * macros from user land. */
1108 #define EXT4_SB(sb)	(sb)
1109 #endif
1110 
1111 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1112 
1113 /*
1114  * Codes for operating systems
1115  */
1116 #define EXT4_OS_LINUX		0
1117 #define EXT4_OS_HURD		1
1118 #define EXT4_OS_MASIX		2
1119 #define EXT4_OS_FREEBSD		3
1120 #define EXT4_OS_LITES		4
1121 
1122 /*
1123  * Revision levels
1124  */
1125 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1126 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1127 
1128 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1129 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1130 
1131 #define EXT4_GOOD_OLD_INODE_SIZE 128
1132 
1133 /*
1134  * Feature set definitions
1135  */
1136 
1137 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1138 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1139 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1140 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1141 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1142 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1143 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1144 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1145 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1146 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1147 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1148 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1149 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1150 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1151 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1152 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1153 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1154 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1155 
1156 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1157 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1158 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1159 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1160 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1161 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1162 
1163 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1164 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1165 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1166 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1167 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1168 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1169 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1170 
1171 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1172 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1173 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1174 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1175 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1176 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1177 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1178 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1179 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1180 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1181 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1182 
1183 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1184 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1185 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1186 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1187 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1188 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1189 					 EXT4_FEATURE_INCOMPAT_FLEX_BG)
1190 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1191 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1192 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1193 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1194 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1195 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1196 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
1197 
1198 /*
1199  * Default values for user and/or group using reserved blocks
1200  */
1201 #define	EXT4_DEF_RESUID		0
1202 #define	EXT4_DEF_RESGID		0
1203 
1204 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1205 
1206 /*
1207  * Default mount options
1208  */
1209 #define EXT4_DEFM_DEBUG		0x0001
1210 #define EXT4_DEFM_BSDGROUPS	0x0002
1211 #define EXT4_DEFM_XATTR_USER	0x0004
1212 #define EXT4_DEFM_ACL		0x0008
1213 #define EXT4_DEFM_UID16		0x0010
1214 #define EXT4_DEFM_JMODE		0x0060
1215 #define EXT4_DEFM_JMODE_DATA	0x0020
1216 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1217 #define EXT4_DEFM_JMODE_WBACK	0x0060
1218 
1219 /*
1220  * Default journal batch times
1221  */
1222 #define EXT4_DEF_MIN_BATCH_TIME	0
1223 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1224 
1225 /*
1226  * Minimum number of groups in a flexgroup before we separate out
1227  * directories into the first block group of a flexgroup
1228  */
1229 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1230 
1231 /*
1232  * Structure of a directory entry
1233  */
1234 #define EXT4_NAME_LEN 255
1235 
1236 struct ext4_dir_entry {
1237 	__le32	inode;			/* Inode number */
1238 	__le16	rec_len;		/* Directory entry length */
1239 	__le16	name_len;		/* Name length */
1240 	char	name[EXT4_NAME_LEN];	/* File name */
1241 };
1242 
1243 /*
1244  * The new version of the directory entry.  Since EXT4 structures are
1245  * stored in intel byte order, and the name_len field could never be
1246  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1247  * file_type field.
1248  */
1249 struct ext4_dir_entry_2 {
1250 	__le32	inode;			/* Inode number */
1251 	__le16	rec_len;		/* Directory entry length */
1252 	__u8	name_len;		/* Name length */
1253 	__u8	file_type;
1254 	char	name[EXT4_NAME_LEN];	/* File name */
1255 };
1256 
1257 /*
1258  * Ext4 directory file types.  Only the low 3 bits are used.  The
1259  * other bits are reserved for now.
1260  */
1261 #define EXT4_FT_UNKNOWN		0
1262 #define EXT4_FT_REG_FILE	1
1263 #define EXT4_FT_DIR		2
1264 #define EXT4_FT_CHRDEV		3
1265 #define EXT4_FT_BLKDEV		4
1266 #define EXT4_FT_FIFO		5
1267 #define EXT4_FT_SOCK		6
1268 #define EXT4_FT_SYMLINK		7
1269 
1270 #define EXT4_FT_MAX		8
1271 
1272 /*
1273  * EXT4_DIR_PAD defines the directory entries boundaries
1274  *
1275  * NOTE: It must be a multiple of 4
1276  */
1277 #define EXT4_DIR_PAD			4
1278 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1279 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1280 					 ~EXT4_DIR_ROUND)
1281 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1282 
1283 /*
1284  * Hash Tree Directory indexing
1285  * (c) Daniel Phillips, 2001
1286  */
1287 
1288 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1289 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1290 		      (EXT4_I(dir)->i_flags & EXT4_INDEX_FL))
1291 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1292 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1293 
1294 /* Legal values for the dx_root hash_version field: */
1295 
1296 #define DX_HASH_LEGACY		0
1297 #define DX_HASH_HALF_MD4	1
1298 #define DX_HASH_TEA		2
1299 #define DX_HASH_LEGACY_UNSIGNED	3
1300 #define DX_HASH_HALF_MD4_UNSIGNED	4
1301 #define DX_HASH_TEA_UNSIGNED		5
1302 
1303 #ifdef __KERNEL__
1304 
1305 /* hash info structure used by the directory hash */
1306 struct dx_hash_info
1307 {
1308 	u32		hash;
1309 	u32		minor_hash;
1310 	int		hash_version;
1311 	u32		*seed;
1312 };
1313 
1314 #define EXT4_HTREE_EOF	0x7fffffff
1315 
1316 /*
1317  * Control parameters used by ext4_htree_next_block
1318  */
1319 #define HASH_NB_ALWAYS		1
1320 
1321 
1322 /*
1323  * Describe an inode's exact location on disk and in memory
1324  */
1325 struct ext4_iloc
1326 {
1327 	struct buffer_head *bh;
1328 	unsigned long offset;
1329 	ext4_group_t block_group;
1330 };
1331 
1332 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1333 {
1334 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1335 }
1336 
1337 /*
1338  * This structure is stuffed into the struct file's private_data field
1339  * for directories.  It is where we put information so that we can do
1340  * readdir operations in hash tree order.
1341  */
1342 struct dir_private_info {
1343 	struct rb_root	root;
1344 	struct rb_node	*curr_node;
1345 	struct fname	*extra_fname;
1346 	loff_t		last_pos;
1347 	__u32		curr_hash;
1348 	__u32		curr_minor_hash;
1349 	__u32		next_hash;
1350 };
1351 
1352 /* calculate the first block number of the group */
1353 static inline ext4_fsblk_t
1354 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1355 {
1356 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1357 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1358 }
1359 
1360 /*
1361  * Special error return code only used by dx_probe() and its callers.
1362  */
1363 #define ERR_BAD_DX_DIR	-75000
1364 
1365 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1366 			ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1367 
1368 extern struct proc_dir_entry *ext4_proc_root;
1369 
1370 /*
1371  * Function prototypes
1372  */
1373 
1374 /*
1375  * Ok, these declarations are also in <linux/kernel.h> but none of the
1376  * ext4 source programs needs to include it so they are duplicated here.
1377  */
1378 # define NORET_TYPE	/**/
1379 # define ATTRIB_NORET	__attribute__((noreturn))
1380 # define NORET_AND	noreturn,
1381 
1382 /* bitmap.c */
1383 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
1384 
1385 /* balloc.c */
1386 extern unsigned int ext4_block_group(struct super_block *sb,
1387 			ext4_fsblk_t blocknr);
1388 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1389 			ext4_fsblk_t blocknr);
1390 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1391 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1392 			ext4_group_t group);
1393 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1394 			ext4_fsblk_t goal, unsigned long *count, int *errp);
1395 extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1396 extern int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1397 extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
1398 				ext4_fsblk_t block, unsigned long count);
1399 extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
1400 extern void ext4_check_blocks_bitmap(struct super_block *);
1401 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1402 						    ext4_group_t block_group,
1403 						    struct buffer_head ** bh);
1404 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1405 struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1406 				      ext4_group_t block_group);
1407 extern unsigned ext4_init_block_bitmap(struct super_block *sb,
1408 				       struct buffer_head *bh,
1409 				       ext4_group_t group,
1410 				       struct ext4_group_desc *desc);
1411 #define ext4_free_blocks_after_init(sb, group, desc)			\
1412 		ext4_init_block_bitmap(sb, NULL, group, desc)
1413 
1414 /* dir.c */
1415 extern int ext4_check_dir_entry(const char *, struct inode *,
1416 				struct ext4_dir_entry_2 *,
1417 				struct buffer_head *, unsigned int);
1418 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1419 				    __u32 minor_hash,
1420 				    struct ext4_dir_entry_2 *dirent);
1421 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1422 
1423 /* fsync.c */
1424 extern int ext4_sync_file(struct file *, struct dentry *, int);
1425 
1426 /* hash.c */
1427 extern int ext4fs_dirhash(const char *name, int len, struct
1428 			  dx_hash_info *hinfo);
1429 
1430 /* ialloc.c */
1431 extern struct inode *ext4_new_inode(handle_t *, struct inode *, int,
1432 				    const struct qstr *qstr, __u32 goal);
1433 extern void ext4_free_inode(handle_t *, struct inode *);
1434 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1435 extern unsigned long ext4_count_free_inodes(struct super_block *);
1436 extern unsigned long ext4_count_dirs(struct super_block *);
1437 extern void ext4_check_inodes_bitmap(struct super_block *);
1438 extern unsigned ext4_init_inode_bitmap(struct super_block *sb,
1439 				       struct buffer_head *bh,
1440 				       ext4_group_t group,
1441 				       struct ext4_group_desc *desc);
1442 extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1443 
1444 /* mballoc.c */
1445 extern long ext4_mb_stats;
1446 extern long ext4_mb_max_to_scan;
1447 extern int ext4_mb_init(struct super_block *, int);
1448 extern int ext4_mb_release(struct super_block *);
1449 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1450 				struct ext4_allocation_request *, int *);
1451 extern int ext4_mb_reserve_blocks(struct super_block *, int);
1452 extern void ext4_discard_preallocations(struct inode *);
1453 extern int __init init_ext4_mballoc(void);
1454 extern void exit_ext4_mballoc(void);
1455 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1456 			     struct buffer_head *bh, ext4_fsblk_t block,
1457 			     unsigned long count, int flags);
1458 extern int ext4_mb_add_groupinfo(struct super_block *sb,
1459 		ext4_group_t i, struct ext4_group_desc *desc);
1460 extern int ext4_mb_get_buddy_cache_lock(struct super_block *, ext4_group_t);
1461 extern void ext4_mb_put_buddy_cache_lock(struct super_block *,
1462 						ext4_group_t, int);
1463 /* inode.c */
1464 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1465 						ext4_lblk_t, int, int *);
1466 struct buffer_head *ext4_bread(handle_t *, struct inode *,
1467 						ext4_lblk_t, int, int *);
1468 int ext4_get_block(struct inode *inode, sector_t iblock,
1469 				struct buffer_head *bh_result, int create);
1470 
1471 extern struct inode *ext4_iget(struct super_block *, unsigned long);
1472 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
1473 extern int  ext4_setattr(struct dentry *, struct iattr *);
1474 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1475 				struct kstat *stat);
1476 extern void ext4_delete_inode(struct inode *);
1477 extern int  ext4_sync_inode(handle_t *, struct inode *);
1478 extern void ext4_dirty_inode(struct inode *);
1479 extern int ext4_change_inode_journal_flag(struct inode *, int);
1480 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1481 extern int ext4_can_truncate(struct inode *inode);
1482 extern void ext4_truncate(struct inode *);
1483 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
1484 extern void ext4_set_inode_flags(struct inode *);
1485 extern void ext4_get_inode_flags(struct ext4_inode_info *);
1486 extern int ext4_alloc_da_blocks(struct inode *inode);
1487 extern void ext4_set_aops(struct inode *inode);
1488 extern int ext4_writepage_trans_blocks(struct inode *);
1489 extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);
1490 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1491 extern int ext4_block_truncate_page(handle_t *handle,
1492 		struct address_space *mapping, loff_t from);
1493 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1494 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
1495 extern int flush_completed_IO(struct inode *inode);
1496 extern void ext4_da_update_reserve_space(struct inode *inode,
1497 					int used, int quota_claim);
1498 /* ioctl.c */
1499 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1500 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1501 
1502 /* migrate.c */
1503 extern int ext4_ext_migrate(struct inode *);
1504 
1505 /* namei.c */
1506 extern unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize);
1507 extern __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize);
1508 extern int ext4_orphan_add(handle_t *, struct inode *);
1509 extern int ext4_orphan_del(handle_t *, struct inode *);
1510 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1511 				__u32 start_minor_hash, __u32 *next_hash);
1512 
1513 /* resize.c */
1514 extern int ext4_group_add(struct super_block *sb,
1515 				struct ext4_new_group_data *input);
1516 extern int ext4_group_extend(struct super_block *sb,
1517 				struct ext4_super_block *es,
1518 				ext4_fsblk_t n_blocks_count);
1519 
1520 /* super.c */
1521 extern void __ext4_error(struct super_block *, const char *, const char *, ...)
1522 	__attribute__ ((format (printf, 3, 4)));
1523 #define ext4_error(sb, message...)	__ext4_error(sb, __func__, ## message)
1524 extern void ext4_error_inode(const char *, struct inode *, const char *, ...)
1525 	__attribute__ ((format (printf, 3, 4)));
1526 extern void ext4_error_file(const char *, struct file *, const char *, ...)
1527 	__attribute__ ((format (printf, 3, 4)));
1528 extern void __ext4_std_error(struct super_block *, const char *, int);
1529 extern void ext4_abort(struct super_block *, const char *, const char *, ...)
1530 	__attribute__ ((format (printf, 3, 4)));
1531 extern void __ext4_warning(struct super_block *, const char *,
1532 			  const char *, ...)
1533 	__attribute__ ((format (printf, 3, 4)));
1534 #define ext4_warning(sb, message...)	__ext4_warning(sb, __func__, ## message)
1535 extern void ext4_msg(struct super_block *, const char *, const char *, ...)
1536 	__attribute__ ((format (printf, 3, 4)));
1537 extern void ext4_grp_locked_error(struct super_block *, ext4_group_t,
1538 				const char *, const char *, ...)
1539 	__attribute__ ((format (printf, 4, 5)));
1540 extern void ext4_update_dynamic_rev(struct super_block *sb);
1541 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1542 					__u32 compat);
1543 extern int ext4_update_rocompat_feature(handle_t *handle,
1544 					struct super_block *sb,	__u32 rocompat);
1545 extern int ext4_update_incompat_feature(handle_t *handle,
1546 					struct super_block *sb,	__u32 incompat);
1547 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1548 				      struct ext4_group_desc *bg);
1549 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1550 				      struct ext4_group_desc *bg);
1551 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1552 				     struct ext4_group_desc *bg);
1553 extern __u32 ext4_free_blks_count(struct super_block *sb,
1554 				struct ext4_group_desc *bg);
1555 extern __u32 ext4_free_inodes_count(struct super_block *sb,
1556 				 struct ext4_group_desc *bg);
1557 extern __u32 ext4_used_dirs_count(struct super_block *sb,
1558 				struct ext4_group_desc *bg);
1559 extern __u32 ext4_itable_unused_count(struct super_block *sb,
1560 				   struct ext4_group_desc *bg);
1561 extern void ext4_block_bitmap_set(struct super_block *sb,
1562 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1563 extern void ext4_inode_bitmap_set(struct super_block *sb,
1564 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1565 extern void ext4_inode_table_set(struct super_block *sb,
1566 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
1567 extern void ext4_free_blks_set(struct super_block *sb,
1568 			       struct ext4_group_desc *bg, __u32 count);
1569 extern void ext4_free_inodes_set(struct super_block *sb,
1570 				struct ext4_group_desc *bg, __u32 count);
1571 extern void ext4_used_dirs_set(struct super_block *sb,
1572 				struct ext4_group_desc *bg, __u32 count);
1573 extern void ext4_itable_unused_set(struct super_block *sb,
1574 				   struct ext4_group_desc *bg, __u32 count);
1575 extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
1576 				   struct ext4_group_desc *gdp);
1577 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
1578 				       struct ext4_group_desc *gdp);
1579 
1580 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
1581 {
1582 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
1583 		le32_to_cpu(es->s_blocks_count_lo);
1584 }
1585 
1586 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
1587 {
1588 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
1589 		le32_to_cpu(es->s_r_blocks_count_lo);
1590 }
1591 
1592 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
1593 {
1594 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
1595 		le32_to_cpu(es->s_free_blocks_count_lo);
1596 }
1597 
1598 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
1599 					 ext4_fsblk_t blk)
1600 {
1601 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
1602 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
1603 }
1604 
1605 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
1606 					      ext4_fsblk_t blk)
1607 {
1608 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
1609 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
1610 }
1611 
1612 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
1613 					   ext4_fsblk_t blk)
1614 {
1615 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
1616 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
1617 }
1618 
1619 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
1620 {
1621 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
1622 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
1623 			le32_to_cpu(raw_inode->i_size_lo);
1624 	else
1625 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
1626 }
1627 
1628 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
1629 {
1630 	raw_inode->i_size_lo = cpu_to_le32(i_size);
1631 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
1632 }
1633 
1634 static inline
1635 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
1636 					    ext4_group_t group)
1637 {
1638 	 struct ext4_group_info ***grp_info;
1639 	 long indexv, indexh;
1640 	 grp_info = EXT4_SB(sb)->s_group_info;
1641 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
1642 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
1643 	 return grp_info[indexv][indexh];
1644 }
1645 
1646 /*
1647  * Reading s_groups_count requires using smp_rmb() afterwards.  See
1648  * the locking protocol documented in the comments of ext4_group_add()
1649  * in resize.c
1650  */
1651 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
1652 {
1653 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
1654 
1655 	smp_rmb();
1656 	return ngroups;
1657 }
1658 
1659 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
1660 					     ext4_group_t block_group)
1661 {
1662 	return block_group >> sbi->s_log_groups_per_flex;
1663 }
1664 
1665 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
1666 {
1667 	return 1 << sbi->s_log_groups_per_flex;
1668 }
1669 
1670 #define ext4_std_error(sb, errno)				\
1671 do {								\
1672 	if ((errno))						\
1673 		__ext4_std_error((sb), __func__, (errno));	\
1674 } while (0)
1675 
1676 #ifdef CONFIG_SMP
1677 /* Each CPU can accumulate percpu_counter_batch blocks in their local
1678  * counters. So we need to make sure we have free blocks more
1679  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
1680  */
1681 #define EXT4_FREEBLOCKS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
1682 #else
1683 #define EXT4_FREEBLOCKS_WATERMARK 0
1684 #endif
1685 
1686 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
1687 {
1688 	/*
1689 	 * XXX: replace with spinlock if seen contended -bzzz
1690 	 */
1691 	down_write(&EXT4_I(inode)->i_data_sem);
1692 	if (newsize > EXT4_I(inode)->i_disksize)
1693 		EXT4_I(inode)->i_disksize = newsize;
1694 	up_write(&EXT4_I(inode)->i_data_sem);
1695 	return ;
1696 }
1697 
1698 struct ext4_group_info {
1699 	unsigned long   bb_state;
1700 	struct rb_root  bb_free_root;
1701 	ext4_grpblk_t	bb_first_free;	/* first free block */
1702 	ext4_grpblk_t	bb_free;	/* total free blocks */
1703 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
1704 	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
1705 	struct          list_head bb_prealloc_list;
1706 #ifdef DOUBLE_CHECK
1707 	void            *bb_bitmap;
1708 #endif
1709 	struct rw_semaphore alloc_sem;
1710 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
1711 					 * regions, index is order.
1712 					 * bb_counters[3] = 5 means
1713 					 * 5 free 8-block regions. */
1714 };
1715 
1716 #define EXT4_GROUP_INFO_NEED_INIT_BIT	0
1717 
1718 #define EXT4_MB_GRP_NEED_INIT(grp)	\
1719 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
1720 
1721 #define EXT4_MAX_CONTENTION		8
1722 #define EXT4_CONTENTION_THRESHOLD	2
1723 
1724 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
1725 					      ext4_group_t group)
1726 {
1727 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
1728 }
1729 
1730 /*
1731  * Returns true if the filesystem is busy enough that attempts to
1732  * access the block group locks has run into contention.
1733  */
1734 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
1735 {
1736 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
1737 }
1738 
1739 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
1740 {
1741 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
1742 	if (spin_trylock(lock))
1743 		/*
1744 		 * We're able to grab the lock right away, so drop the
1745 		 * lock contention counter.
1746 		 */
1747 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
1748 	else {
1749 		/*
1750 		 * The lock is busy, so bump the contention counter,
1751 		 * and then wait on the spin lock.
1752 		 */
1753 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
1754 				  EXT4_MAX_CONTENTION);
1755 		spin_lock(lock);
1756 	}
1757 }
1758 
1759 static inline void ext4_unlock_group(struct super_block *sb,
1760 					ext4_group_t group)
1761 {
1762 	spin_unlock(ext4_group_lock_ptr(sb, group));
1763 }
1764 
1765 /*
1766  * Inodes and files operations
1767  */
1768 
1769 /* dir.c */
1770 extern const struct file_operations ext4_dir_operations;
1771 
1772 /* file.c */
1773 extern const struct inode_operations ext4_file_inode_operations;
1774 extern const struct file_operations ext4_file_operations;
1775 
1776 /* namei.c */
1777 extern const struct inode_operations ext4_dir_inode_operations;
1778 extern const struct inode_operations ext4_special_inode_operations;
1779 extern struct dentry *ext4_get_parent(struct dentry *child);
1780 
1781 /* symlink.c */
1782 extern const struct inode_operations ext4_symlink_inode_operations;
1783 extern const struct inode_operations ext4_fast_symlink_inode_operations;
1784 
1785 /* block_validity */
1786 extern void ext4_release_system_zone(struct super_block *sb);
1787 extern int ext4_setup_system_zone(struct super_block *sb);
1788 extern int __init init_ext4_system_zone(void);
1789 extern void exit_ext4_system_zone(void);
1790 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
1791 				 ext4_fsblk_t start_blk,
1792 				 unsigned int count);
1793 
1794 /* extents.c */
1795 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
1796 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
1797 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
1798 				       int chunk);
1799 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
1800 			       struct ext4_map_blocks *map, int flags);
1801 extern void ext4_ext_truncate(struct inode *);
1802 extern void ext4_ext_init(struct super_block *);
1803 extern void ext4_ext_release(struct super_block *);
1804 extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
1805 			  loff_t len);
1806 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
1807 			  ssize_t len);
1808 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
1809 			   struct ext4_map_blocks *map, int flags);
1810 extern int ext4_get_blocks(handle_t *handle, struct inode *inode,
1811 			   sector_t block, unsigned int max_blocks,
1812 			   struct buffer_head *bh, int flags);
1813 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1814 			__u64 start, __u64 len);
1815 /* move_extent.c */
1816 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
1817 			     __u64 start_orig, __u64 start_donor,
1818 			     __u64 len, __u64 *moved_len);
1819 
1820 
1821 /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
1822 enum ext4_state_bits {
1823 	BH_Uninit	/* blocks are allocated but uninitialized on disk */
1824 	  = BH_JBDPrivateStart,
1825 };
1826 
1827 BUFFER_FNS(Uninit, uninit)
1828 TAS_BUFFER_FNS(Uninit, uninit)
1829 
1830 /*
1831  * Add new method to test wether block and inode bitmaps are properly
1832  * initialized. With uninit_bg reading the block from disk is not enough
1833  * to mark the bitmap uptodate. We need to also zero-out the bitmap
1834  */
1835 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
1836 
1837 static inline int bitmap_uptodate(struct buffer_head *bh)
1838 {
1839 	return (buffer_uptodate(bh) &&
1840 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
1841 }
1842 static inline void set_bitmap_uptodate(struct buffer_head *bh)
1843 {
1844 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
1845 }
1846 
1847 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
1848 
1849 #endif	/* __KERNEL__ */
1850 
1851 #endif	/* _EXT4_H */
1852