xref: /openbmc/linux/fs/ext4/ext4.h (revision f710b4b9)
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 /* data type for block offset of block group */
57 typedef int ext4_grpblk_t;
58 
59 /* data type for filesystem-wide blocks number */
60 typedef unsigned long long ext4_fsblk_t;
61 
62 /* data type for file logical block number */
63 typedef __u32 ext4_lblk_t;
64 
65 /* data type for block group number */
66 typedef unsigned int ext4_group_t;
67 
68 /*
69  * Flags used in mballoc's allocation_context flags field.
70  *
71  * Also used to show what's going on for debugging purposes when the
72  * flag field is exported via the traceport interface
73  */
74 
75 /* prefer goal again. length */
76 #define EXT4_MB_HINT_MERGE		0x0001
77 /* blocks already reserved */
78 #define EXT4_MB_HINT_RESERVED		0x0002
79 /* metadata is being allocated */
80 #define EXT4_MB_HINT_METADATA		0x0004
81 /* first blocks in the file */
82 #define EXT4_MB_HINT_FIRST		0x0008
83 /* search for the best chunk */
84 #define EXT4_MB_HINT_BEST		0x0010
85 /* data is being allocated */
86 #define EXT4_MB_HINT_DATA		0x0020
87 /* don't preallocate (for tails) */
88 #define EXT4_MB_HINT_NOPREALLOC		0x0040
89 /* allocate for locality group */
90 #define EXT4_MB_HINT_GROUP_ALLOC	0x0080
91 /* allocate goal blocks or none */
92 #define EXT4_MB_HINT_GOAL_ONLY		0x0100
93 /* goal is meaningful */
94 #define EXT4_MB_HINT_TRY_GOAL		0x0200
95 /* blocks already pre-reserved by delayed allocation */
96 #define EXT4_MB_DELALLOC_RESERVED	0x0400
97 /* We are doing stream allocation */
98 #define EXT4_MB_STREAM_ALLOC		0x0800
99 
100 
101 struct ext4_allocation_request {
102 	/* target inode for block we're allocating */
103 	struct inode *inode;
104 	/* how many blocks we want to allocate */
105 	unsigned int len;
106 	/* logical block in target inode */
107 	ext4_lblk_t logical;
108 	/* the closest logical allocated block to the left */
109 	ext4_lblk_t lleft;
110 	/* the closest logical allocated block to the right */
111 	ext4_lblk_t lright;
112 	/* phys. target (a hint) */
113 	ext4_fsblk_t goal;
114 	/* phys. block for the closest logical allocated block to the left */
115 	ext4_fsblk_t pleft;
116 	/* phys. block for the closest logical allocated block to the right */
117 	ext4_fsblk_t pright;
118 	/* flags. see above EXT4_MB_HINT_* */
119 	unsigned int flags;
120 };
121 
122 /*
123  * For delayed allocation tracking
124  */
125 struct mpage_da_data {
126 	struct inode *inode;
127 	sector_t b_blocknr;		/* start block number of extent */
128 	size_t b_size;			/* size of extent */
129 	unsigned long b_state;		/* state of the extent */
130 	unsigned long first_page, next_page;	/* extent of pages */
131 	struct writeback_control *wbc;
132 	int io_done;
133 	int pages_written;
134 	int retval;
135 };
136 #define	DIO_AIO_UNWRITTEN	0x1
137 typedef struct ext4_io_end {
138 	struct list_head	list;		/* per-file finished AIO list */
139 	struct inode		*inode;		/* file being written to */
140 	unsigned int		flag;		/* unwritten or not */
141 	int			error;		/* I/O error code */
142 	loff_t			offset;		/* offset in the file */
143 	ssize_t			size;		/* size of the extent */
144 	struct work_struct	work;		/* data work queue */
145 } ext4_io_end_t;
146 
147 /*
148  * Special inodes numbers
149  */
150 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
151 #define EXT4_ROOT_INO		 2	/* Root inode */
152 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
153 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
154 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
155 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
156 
157 /* First non-reserved inode for old ext4 filesystems */
158 #define EXT4_GOOD_OLD_FIRST_INO	11
159 
160 /*
161  * Maximal count of links to a file
162  */
163 #define EXT4_LINK_MAX		65000
164 
165 /*
166  * Macro-instructions used to manage several block sizes
167  */
168 #define EXT4_MIN_BLOCK_SIZE		1024
169 #define	EXT4_MAX_BLOCK_SIZE		65536
170 #define EXT4_MIN_BLOCK_LOG_SIZE		10
171 #ifdef __KERNEL__
172 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
173 #else
174 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
175 #endif
176 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
177 #ifdef __KERNEL__
178 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
179 #else
180 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
181 #endif
182 #ifdef __KERNEL__
183 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
184 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
185 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
186 #else
187 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
188 				 EXT4_GOOD_OLD_INODE_SIZE : \
189 				 (s)->s_inode_size)
190 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
191 				 EXT4_GOOD_OLD_FIRST_INO : \
192 				 (s)->s_first_ino)
193 #endif
194 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
195 
196 /*
197  * Structure of a blocks group descriptor
198  */
199 struct ext4_group_desc
200 {
201 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
202 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
203 	__le32	bg_inode_table_lo;	/* Inodes table block */
204 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
205 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
206 	__le16	bg_used_dirs_count_lo;	/* Directories count */
207 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
208 	__u32	bg_reserved[2];		/* Likely block/inode bitmap checksum */
209 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
210 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
211 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
212 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
213 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
214 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
215 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
216 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
217 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
218 	__u32	bg_reserved2[3];
219 };
220 
221 /*
222  * Structure of a flex block group info
223  */
224 
225 struct flex_groups {
226 	atomic_t free_inodes;
227 	atomic_t free_blocks;
228 	atomic_t used_dirs;
229 };
230 
231 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
232 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
233 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
234 
235 /*
236  * Macro-instructions used to manage group descriptors
237  */
238 #define EXT4_MIN_DESC_SIZE		32
239 #define EXT4_MIN_DESC_SIZE_64BIT	64
240 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
241 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
242 #ifdef __KERNEL__
243 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
244 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
245 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
246 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
247 #else
248 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
249 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
250 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
251 #endif
252 
253 /*
254  * Constants relative to the data blocks
255  */
256 #define	EXT4_NDIR_BLOCKS		12
257 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
258 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
259 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
260 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
261 
262 /*
263  * Inode flags
264  */
265 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
266 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
267 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
268 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
269 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
270 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
271 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
272 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
273 /* Reserved for compression usage... */
274 #define EXT4_DIRTY_FL			0x00000100
275 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
276 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
277 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
278 /* End compression flags --- maybe not all used */
279 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
280 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
281 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
282 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
283 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
284 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
285 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
286 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
287 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
288 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
289 
290 #define EXT4_FL_USER_VISIBLE		0x000BDFFF /* User visible flags */
291 #define EXT4_FL_USER_MODIFIABLE		0x000B80FF /* User modifiable flags */
292 
293 /* Flags that should be inherited by new inodes from their parent. */
294 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
295 			   EXT4_SYNC_FL | EXT4_IMMUTABLE_FL | EXT4_APPEND_FL |\
296 			   EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
297 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
298 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
299 
300 /* Flags that are appropriate for regular files (all but dir-specific ones). */
301 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
302 
303 /* Flags that are appropriate for non-directories/regular files. */
304 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
305 
306 /* Mask out flags that are inappropriate for the given type of inode. */
307 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
308 {
309 	if (S_ISDIR(mode))
310 		return flags;
311 	else if (S_ISREG(mode))
312 		return flags & EXT4_REG_FLMASK;
313 	else
314 		return flags & EXT4_OTHER_FLMASK;
315 }
316 
317 /* Used to pass group descriptor data when online resize is done */
318 struct ext4_new_group_input {
319 	__u32 group;		/* Group number for this data */
320 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
321 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
322 	__u64 inode_table;	/* Absolute block number of inode table start */
323 	__u32 blocks_count;	/* Total number of blocks in this group */
324 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
325 	__u16 unused;
326 };
327 
328 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
329 struct ext4_new_group_data {
330 	__u32 group;
331 	__u64 block_bitmap;
332 	__u64 inode_bitmap;
333 	__u64 inode_table;
334 	__u32 blocks_count;
335 	__u16 reserved_blocks;
336 	__u16 unused;
337 	__u32 free_blocks_count;
338 };
339 
340 /*
341  * Flags used by ext4_get_blocks()
342  */
343 	/* Allocate any needed blocks and/or convert an unitialized
344 	   extent to be an initialized ext4 */
345 #define EXT4_GET_BLOCKS_CREATE			0x0001
346 	/* Request the creation of an unitialized extent */
347 #define EXT4_GET_BLOCKS_UNINIT_EXT		0x0002
348 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\
349 						 EXT4_GET_BLOCKS_CREATE)
350 	/* Caller is from the delayed allocation writeout path,
351 	   so set the magic i_delalloc_reserve_flag after taking the
352 	   inode allocation semaphore for */
353 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
354 	/* caller is from the direct IO path, request to creation of an
355 	unitialized extents if not allocated, split the uninitialized
356 	extent if blocks has been preallocated already*/
357 #define EXT4_GET_BLOCKS_DIO			0x0008
358 #define EXT4_GET_BLOCKS_CONVERT			0x0010
359 #define EXT4_GET_BLOCKS_DIO_CREATE_EXT		(EXT4_GET_BLOCKS_DIO|\
360 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
361 	/* Convert extent to initialized after direct IO complete */
362 #define EXT4_GET_BLOCKS_DIO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
363 					 EXT4_GET_BLOCKS_DIO_CREATE_EXT)
364 
365 /*
366  * Flags used by ext4_free_blocks
367  */
368 #define EXT4_FREE_BLOCKS_METADATA	0x0001
369 #define EXT4_FREE_BLOCKS_FORGET		0x0002
370 #define EXT4_FREE_BLOCKS_VALIDATED	0x0004
371 
372 /*
373  * ioctl commands
374  */
375 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
376 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
377 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
378 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
379 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
380 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
381 #ifdef CONFIG_JBD2_DEBUG
382 #define EXT4_IOC_WAIT_FOR_READONLY	_IOR('f', 99, long)
383 #endif
384 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
385 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
386 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
387 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
388 #define EXT4_IOC_MIGRATE		_IO('f', 9)
389  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
390  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
391 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
392 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
393 
394 /*
395  * ioctl commands in 32 bit emulation
396  */
397 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
398 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
399 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
400 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
401 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
402 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
403 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
404 #ifdef CONFIG_JBD2_DEBUG
405 #define EXT4_IOC32_WAIT_FOR_READONLY	_IOR('f', 99, int)
406 #endif
407 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
408 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
409 
410 
411 /*
412  *  Mount options
413  */
414 struct ext4_mount_options {
415 	unsigned long s_mount_opt;
416 	uid_t s_resuid;
417 	gid_t s_resgid;
418 	unsigned long s_commit_interval;
419 	u32 s_min_batch_time, s_max_batch_time;
420 #ifdef CONFIG_QUOTA
421 	int s_jquota_fmt;
422 	char *s_qf_names[MAXQUOTAS];
423 #endif
424 };
425 
426 /* Max physical block we can addres w/o extents */
427 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
428 
429 /*
430  * Structure of an inode on the disk
431  */
432 struct ext4_inode {
433 	__le16	i_mode;		/* File mode */
434 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
435 	__le32	i_size_lo;	/* Size in bytes */
436 	__le32	i_atime;	/* Access time */
437 	__le32	i_ctime;	/* Inode Change time */
438 	__le32	i_mtime;	/* Modification time */
439 	__le32	i_dtime;	/* Deletion Time */
440 	__le16	i_gid;		/* Low 16 bits of Group Id */
441 	__le16	i_links_count;	/* Links count */
442 	__le32	i_blocks_lo;	/* Blocks count */
443 	__le32	i_flags;	/* File flags */
444 	union {
445 		struct {
446 			__le32  l_i_version;
447 		} linux1;
448 		struct {
449 			__u32  h_i_translator;
450 		} hurd1;
451 		struct {
452 			__u32  m_i_reserved1;
453 		} masix1;
454 	} osd1;				/* OS dependent 1 */
455 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
456 	__le32	i_generation;	/* File version (for NFS) */
457 	__le32	i_file_acl_lo;	/* File ACL */
458 	__le32	i_size_high;
459 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
460 	union {
461 		struct {
462 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
463 			__le16	l_i_file_acl_high;
464 			__le16	l_i_uid_high;	/* these 2 fields */
465 			__le16	l_i_gid_high;	/* were reserved2[0] */
466 			__u32	l_i_reserved2;
467 		} linux2;
468 		struct {
469 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
470 			__u16	h_i_mode_high;
471 			__u16	h_i_uid_high;
472 			__u16	h_i_gid_high;
473 			__u32	h_i_author;
474 		} hurd2;
475 		struct {
476 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
477 			__le16	m_i_file_acl_high;
478 			__u32	m_i_reserved2[2];
479 		} masix2;
480 	} osd2;				/* OS dependent 2 */
481 	__le16	i_extra_isize;
482 	__le16	i_pad1;
483 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
484 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
485 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
486 	__le32  i_crtime;       /* File Creation time */
487 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
488 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
489 };
490 
491 struct move_extent {
492 	__u32 reserved;		/* should be zero */
493 	__u32 donor_fd;		/* donor file descriptor */
494 	__u64 orig_start;	/* logical start offset in block for orig */
495 	__u64 donor_start;	/* logical start offset in block for donor */
496 	__u64 len;		/* block length to be moved */
497 	__u64 moved_len;	/* moved block length */
498 };
499 
500 #define EXT4_EPOCH_BITS 2
501 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
502 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
503 
504 /*
505  * Extended fields will fit into an inode if the filesystem was formatted
506  * with large inodes (-I 256 or larger) and there are not currently any EAs
507  * consuming all of the available space. For new inodes we always reserve
508  * enough space for the kernel's known extended fields, but for inodes
509  * created with an old kernel this might not have been the case. None of
510  * the extended inode fields is critical for correct filesystem operation.
511  * This macro checks if a certain field fits in the inode. Note that
512  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
513  */
514 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
515 	((offsetof(typeof(*ext4_inode), field) +	\
516 	  sizeof((ext4_inode)->field))			\
517 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
518 	    (einode)->i_extra_isize))			\
519 
520 static inline __le32 ext4_encode_extra_time(struct timespec *time)
521 {
522        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
523 			   (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
524                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
525 }
526 
527 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
528 {
529        if (sizeof(time->tv_sec) > 4)
530 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
531 			       << 32;
532        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
533 }
534 
535 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
536 do {									       \
537 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
538 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
539 		(raw_inode)->xtime ## _extra =				       \
540 				ext4_encode_extra_time(&(inode)->xtime);       \
541 } while (0)
542 
543 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
544 do {									       \
545 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
546 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
547 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
548 		(raw_inode)->xtime ## _extra =				       \
549 				ext4_encode_extra_time(&(einode)->xtime);      \
550 } while (0)
551 
552 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
553 do {									       \
554 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
555 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
556 		ext4_decode_extra_time(&(inode)->xtime,			       \
557 				       raw_inode->xtime ## _extra);	       \
558 } while (0)
559 
560 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
561 do {									       \
562 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
563 		(einode)->xtime.tv_sec = 				       \
564 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
565 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
566 		ext4_decode_extra_time(&(einode)->xtime,		       \
567 				       raw_inode->xtime ## _extra);	       \
568 } while (0)
569 
570 #define i_disk_version osd1.linux1.l_i_version
571 
572 #if defined(__KERNEL__) || defined(__linux__)
573 #define i_reserved1	osd1.linux1.l_i_reserved1
574 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
575 #define i_blocks_high	osd2.linux2.l_i_blocks_high
576 #define i_uid_low	i_uid
577 #define i_gid_low	i_gid
578 #define i_uid_high	osd2.linux2.l_i_uid_high
579 #define i_gid_high	osd2.linux2.l_i_gid_high
580 #define i_reserved2	osd2.linux2.l_i_reserved2
581 
582 #elif defined(__GNU__)
583 
584 #define i_translator	osd1.hurd1.h_i_translator
585 #define i_uid_high	osd2.hurd2.h_i_uid_high
586 #define i_gid_high	osd2.hurd2.h_i_gid_high
587 #define i_author	osd2.hurd2.h_i_author
588 
589 #elif defined(__masix__)
590 
591 #define i_reserved1	osd1.masix1.m_i_reserved1
592 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
593 #define i_reserved2	osd2.masix2.m_i_reserved2
594 
595 #endif /* defined(__KERNEL__) || defined(__linux__) */
596 
597 /*
598  * storage for cached extent
599  */
600 struct ext4_ext_cache {
601 	ext4_fsblk_t	ec_start;
602 	ext4_lblk_t	ec_block;
603 	__u32		ec_len; /* must be 32bit to return holes */
604 	__u32		ec_type;
605 };
606 
607 /*
608  * fourth extended file system inode data in memory
609  */
610 struct ext4_inode_info {
611 	__le32	i_data[15];	/* unconverted */
612 	__u32	i_flags;
613 	ext4_fsblk_t	i_file_acl;
614 	__u32	i_dtime;
615 
616 	/*
617 	 * i_block_group is the number of the block group which contains
618 	 * this file's inode.  Constant across the lifetime of the inode,
619 	 * it is ued for making block allocation decisions - we try to
620 	 * place a file's data blocks near its inode block, and new inodes
621 	 * near to their parent directory's inode.
622 	 */
623 	ext4_group_t	i_block_group;
624 	unsigned long	i_state_flags;		/* Dynamic state flags */
625 
626 	ext4_lblk_t		i_dir_start_lookup;
627 #ifdef CONFIG_EXT4_FS_XATTR
628 	/*
629 	 * Extended attributes can be read independently of the main file
630 	 * data. Taking i_mutex even when reading would cause contention
631 	 * between readers of EAs and writers of regular file data, so
632 	 * instead we synchronize on xattr_sem when reading or changing
633 	 * EAs.
634 	 */
635 	struct rw_semaphore xattr_sem;
636 #endif
637 
638 	struct list_head i_orphan;	/* unlinked but open inodes */
639 
640 	/*
641 	 * i_disksize keeps track of what the inode size is ON DISK, not
642 	 * in memory.  During truncate, i_size is set to the new size by
643 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
644 	 * set i_disksize to 0 until the truncate is actually under way.
645 	 *
646 	 * The intent is that i_disksize always represents the blocks which
647 	 * are used by this file.  This allows recovery to restart truncate
648 	 * on orphans if we crash during truncate.  We actually write i_disksize
649 	 * into the on-disk inode when writing inodes out, instead of i_size.
650 	 *
651 	 * The only time when i_disksize and i_size may be different is when
652 	 * a truncate is in progress.  The only things which change i_disksize
653 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
654 	 */
655 	loff_t	i_disksize;
656 
657 	/*
658 	 * i_data_sem is for serialising ext4_truncate() against
659 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
660 	 * data tree are chopped off during truncate. We can't do that in
661 	 * ext4 because whenever we perform intermediate commits during
662 	 * truncate, the inode and all the metadata blocks *must* be in a
663 	 * consistent state which allows truncation of the orphans to restart
664 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
665 	 * by other means, so we have i_data_sem.
666 	 */
667 	struct rw_semaphore i_data_sem;
668 	struct inode vfs_inode;
669 	struct jbd2_inode jinode;
670 
671 	struct ext4_ext_cache i_cached_extent;
672 	/*
673 	 * File creation time. Its function is same as that of
674 	 * struct timespec i_{a,c,m}time in the generic inode.
675 	 */
676 	struct timespec i_crtime;
677 
678 	/* mballoc */
679 	struct list_head i_prealloc_list;
680 	spinlock_t i_prealloc_lock;
681 
682 	/* ialloc */
683 	ext4_group_t	i_last_alloc_group;
684 
685 	/* allocation reservation info for delalloc */
686 	unsigned int i_reserved_data_blocks;
687 	unsigned int i_reserved_meta_blocks;
688 	unsigned int i_allocated_meta_blocks;
689 	unsigned short i_delalloc_reserved_flag;
690 	sector_t i_da_metadata_calc_last_lblock;
691 	int i_da_metadata_calc_len;
692 
693 	/* on-disk additional length */
694 	__u16 i_extra_isize;
695 
696 	spinlock_t i_block_reservation_lock;
697 #ifdef CONFIG_QUOTA
698 	/* quota space reservation, managed internally by quota code */
699 	qsize_t i_reserved_quota;
700 #endif
701 
702 	/* completed async DIOs that might need unwritten extents handling */
703 	struct list_head i_aio_dio_complete_list;
704 	/* current io_end structure for async DIO write*/
705 	ext4_io_end_t *cur_aio_dio;
706 
707 	/*
708 	 * Transactions that contain inode's metadata needed to complete
709 	 * fsync and fdatasync, respectively.
710 	 */
711 	tid_t i_sync_tid;
712 	tid_t i_datasync_tid;
713 };
714 
715 /*
716  * File system states
717  */
718 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
719 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
720 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
721 
722 /*
723  * Misc. filesystem flags
724  */
725 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
726 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
727 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
728 
729 /*
730  * Mount flags
731  */
732 #define EXT4_MOUNT_OLDALLOC		0x00002  /* Don't use the new Orlov allocator */
733 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
734 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
735 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
736 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
737 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
738 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
739 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
740 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
741 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
742 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
743 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
744 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
745 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
746 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
747 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
748 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
749 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
750 #define EXT4_MOUNT_NOBH			0x40000 /* No bufferheads */
751 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
752 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
753 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
754 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
755 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
756 #define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
757 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
758 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
759 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
760 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
761 
762 #define clear_opt(o, opt)		o &= ~EXT4_MOUNT_##opt
763 #define set_opt(o, opt)			o |= EXT4_MOUNT_##opt
764 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
765 					 EXT4_MOUNT_##opt)
766 
767 #define ext4_set_bit			ext2_set_bit
768 #define ext4_set_bit_atomic		ext2_set_bit_atomic
769 #define ext4_clear_bit			ext2_clear_bit
770 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
771 #define ext4_test_bit			ext2_test_bit
772 #define ext4_find_first_zero_bit	ext2_find_first_zero_bit
773 #define ext4_find_next_zero_bit		ext2_find_next_zero_bit
774 #define ext4_find_next_bit		ext2_find_next_bit
775 
776 /*
777  * Maximal mount counts between two filesystem checks
778  */
779 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
780 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
781 
782 /*
783  * Behaviour when detecting errors
784  */
785 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
786 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
787 #define EXT4_ERRORS_PANIC		3	/* Panic */
788 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
789 
790 /*
791  * Structure of the super block
792  */
793 struct ext4_super_block {
794 /*00*/	__le32	s_inodes_count;		/* Inodes count */
795 	__le32	s_blocks_count_lo;	/* Blocks count */
796 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
797 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
798 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
799 	__le32	s_first_data_block;	/* First Data Block */
800 	__le32	s_log_block_size;	/* Block size */
801 	__le32	s_obso_log_frag_size;	/* Obsoleted fragment size */
802 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
803 	__le32	s_obso_frags_per_group;	/* Obsoleted fragments per group */
804 	__le32	s_inodes_per_group;	/* # Inodes per group */
805 	__le32	s_mtime;		/* Mount time */
806 /*30*/	__le32	s_wtime;		/* Write time */
807 	__le16	s_mnt_count;		/* Mount count */
808 	__le16	s_max_mnt_count;	/* Maximal mount count */
809 	__le16	s_magic;		/* Magic signature */
810 	__le16	s_state;		/* File system state */
811 	__le16	s_errors;		/* Behaviour when detecting errors */
812 	__le16	s_minor_rev_level;	/* minor revision level */
813 /*40*/	__le32	s_lastcheck;		/* time of last check */
814 	__le32	s_checkinterval;	/* max. time between checks */
815 	__le32	s_creator_os;		/* OS */
816 	__le32	s_rev_level;		/* Revision level */
817 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
818 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
819 	/*
820 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
821 	 *
822 	 * Note: the difference between the compatible feature set and
823 	 * the incompatible feature set is that if there is a bit set
824 	 * in the incompatible feature set that the kernel doesn't
825 	 * know about, it should refuse to mount the filesystem.
826 	 *
827 	 * e2fsck's requirements are more strict; if it doesn't know
828 	 * about a feature in either the compatible or incompatible
829 	 * feature set, it must abort and not try to meddle with
830 	 * things it doesn't understand...
831 	 */
832 	__le32	s_first_ino;		/* First non-reserved inode */
833 	__le16  s_inode_size;		/* size of inode structure */
834 	__le16	s_block_group_nr;	/* block group # of this superblock */
835 	__le32	s_feature_compat;	/* compatible feature set */
836 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
837 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
838 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
839 /*78*/	char	s_volume_name[16];	/* volume name */
840 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
841 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
842 	/*
843 	 * Performance hints.  Directory preallocation should only
844 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
845 	 */
846 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
847 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
848 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
849 	/*
850 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
851 	 */
852 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
853 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
854 	__le32	s_journal_dev;		/* device number of journal file */
855 	__le32	s_last_orphan;		/* start of list of inodes to delete */
856 	__le32	s_hash_seed[4];		/* HTREE hash seed */
857 	__u8	s_def_hash_version;	/* Default hash version to use */
858 	__u8	s_reserved_char_pad;
859 	__le16  s_desc_size;		/* size of group descriptor */
860 /*100*/	__le32	s_default_mount_opts;
861 	__le32	s_first_meta_bg;	/* First metablock block group */
862 	__le32	s_mkfs_time;		/* When the filesystem was created */
863 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
864 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
865 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
866 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
867 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
868 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
869 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
870 	__le32	s_flags;		/* Miscellaneous flags */
871 	__le16  s_raid_stride;		/* RAID stride */
872 	__le16  s_mmp_interval;         /* # seconds to wait in MMP checking */
873 	__le64  s_mmp_block;            /* Block for multi-mount protection */
874 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
875 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
876 	__u8	s_reserved_char_pad2;
877 	__le16  s_reserved_pad;
878 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
879 	__u32   s_reserved[160];        /* Padding to the end of the block */
880 };
881 
882 #ifdef __KERNEL__
883 
884 /*
885  * run-time mount flags
886  */
887 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
888 #define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
889 
890 /*
891  * fourth extended-fs super-block data in memory
892  */
893 struct ext4_sb_info {
894 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
895 	unsigned long s_inodes_per_block;/* Number of inodes per block */
896 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
897 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
898 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
899 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
900 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
901 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
902 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
903 	unsigned long s_overhead_last;  /* Last calculated overhead */
904 	unsigned long s_blocks_last;    /* Last seen block count */
905 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
906 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
907 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
908 	struct buffer_head **s_group_desc;
909 	unsigned int s_mount_opt;
910 	unsigned int s_mount_flags;
911 	ext4_fsblk_t s_sb_block;
912 	uid_t s_resuid;
913 	gid_t s_resgid;
914 	unsigned short s_mount_state;
915 	unsigned short s_pad;
916 	int s_addr_per_block_bits;
917 	int s_desc_per_block_bits;
918 	int s_inode_size;
919 	int s_first_ino;
920 	unsigned int s_inode_readahead_blks;
921 	unsigned int s_inode_goal;
922 	spinlock_t s_next_gen_lock;
923 	u32 s_next_generation;
924 	u32 s_hash_seed[4];
925 	int s_def_hash_version;
926 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
927 	struct percpu_counter s_freeblocks_counter;
928 	struct percpu_counter s_freeinodes_counter;
929 	struct percpu_counter s_dirs_counter;
930 	struct percpu_counter s_dirtyblocks_counter;
931 	struct blockgroup_lock *s_blockgroup_lock;
932 	struct proc_dir_entry *s_proc;
933 	struct kobject s_kobj;
934 	struct completion s_kobj_unregister;
935 
936 	/* Journaling */
937 	struct inode *s_journal_inode;
938 	struct journal_s *s_journal;
939 	struct list_head s_orphan;
940 	struct mutex s_orphan_lock;
941 	struct mutex s_resize_lock;
942 	unsigned long s_commit_interval;
943 	u32 s_max_batch_time;
944 	u32 s_min_batch_time;
945 	struct block_device *journal_bdev;
946 #ifdef CONFIG_JBD2_DEBUG
947 	struct timer_list turn_ro_timer;	/* For turning read-only (crash simulation) */
948 	wait_queue_head_t ro_wait_queue;	/* For people waiting for the fs to go read-only */
949 #endif
950 #ifdef CONFIG_QUOTA
951 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
952 	int s_jquota_fmt;			/* Format of quota to use */
953 #endif
954 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
955 	struct rb_root system_blks;
956 
957 #ifdef EXTENTS_STATS
958 	/* ext4 extents stats */
959 	unsigned long s_ext_min;
960 	unsigned long s_ext_max;
961 	unsigned long s_depth_max;
962 	spinlock_t s_ext_stats_lock;
963 	unsigned long s_ext_blocks;
964 	unsigned long s_ext_extents;
965 #endif
966 
967 	/* for buddy allocator */
968 	struct ext4_group_info ***s_group_info;
969 	struct inode *s_buddy_cache;
970 	long s_blocks_reserved;
971 	spinlock_t s_reserve_lock;
972 	spinlock_t s_md_lock;
973 	tid_t s_last_transaction;
974 	unsigned short *s_mb_offsets;
975 	unsigned int *s_mb_maxs;
976 
977 	/* tunables */
978 	unsigned long s_stripe;
979 	unsigned int s_mb_stream_request;
980 	unsigned int s_mb_max_to_scan;
981 	unsigned int s_mb_min_to_scan;
982 	unsigned int s_mb_stats;
983 	unsigned int s_mb_order2_reqs;
984 	unsigned int s_mb_group_prealloc;
985 	unsigned int s_max_writeback_mb_bump;
986 	/* where last allocation was done - for stream allocation */
987 	unsigned long s_mb_last_group;
988 	unsigned long s_mb_last_start;
989 
990 	/* stats for buddy allocator */
991 	spinlock_t s_mb_pa_lock;
992 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
993 	atomic_t s_bal_success;	/* we found long enough chunks */
994 	atomic_t s_bal_allocated;	/* in blocks */
995 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
996 	atomic_t s_bal_goals;	/* goal hits */
997 	atomic_t s_bal_breaks;	/* too long searches */
998 	atomic_t s_bal_2orders;	/* 2^order hits */
999 	spinlock_t s_bal_lock;
1000 	unsigned long s_mb_buddies_generated;
1001 	unsigned long long s_mb_generation_time;
1002 	atomic_t s_mb_lost_chunks;
1003 	atomic_t s_mb_preallocated;
1004 	atomic_t s_mb_discarded;
1005 	atomic_t s_lock_busy;
1006 
1007 	/* locality groups */
1008 	struct ext4_locality_group *s_locality_groups;
1009 
1010 	/* for write statistics */
1011 	unsigned long s_sectors_written_start;
1012 	u64 s_kbytes_written;
1013 
1014 	unsigned int s_log_groups_per_flex;
1015 	struct flex_groups *s_flex_groups;
1016 
1017 	/* workqueue for dio unwritten */
1018 	struct workqueue_struct *dio_unwritten_wq;
1019 };
1020 
1021 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1022 {
1023 	return sb->s_fs_info;
1024 }
1025 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1026 {
1027 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1028 }
1029 
1030 static inline struct timespec ext4_current_time(struct inode *inode)
1031 {
1032 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1033 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1034 }
1035 
1036 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1037 {
1038 	return ino == EXT4_ROOT_INO ||
1039 		ino == EXT4_JOURNAL_INO ||
1040 		ino == EXT4_RESIZE_INO ||
1041 		(ino >= EXT4_FIRST_INO(sb) &&
1042 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1043 }
1044 
1045 /*
1046  * Inode dynamic state flags
1047  */
1048 enum {
1049 	EXT4_STATE_JDATA,		/* journaled data exists */
1050 	EXT4_STATE_NEW,			/* inode is newly created */
1051 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1052 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1053 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1054 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1055 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1056 };
1057 
1058 static inline int ext4_test_inode_state(struct inode *inode, int bit)
1059 {
1060 	return test_bit(bit, &EXT4_I(inode)->i_state_flags);
1061 }
1062 
1063 static inline void ext4_set_inode_state(struct inode *inode, int bit)
1064 {
1065 	set_bit(bit, &EXT4_I(inode)->i_state_flags);
1066 }
1067 
1068 static inline void ext4_clear_inode_state(struct inode *inode, int bit)
1069 {
1070 	clear_bit(bit, &EXT4_I(inode)->i_state_flags);
1071 }
1072 #else
1073 /* Assume that user mode programs are passing in an ext4fs superblock, not
1074  * a kernel struct super_block.  This will allow us to call the feature-test
1075  * macros from user land. */
1076 #define EXT4_SB(sb)	(sb)
1077 #endif
1078 
1079 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1080 
1081 /*
1082  * Codes for operating systems
1083  */
1084 #define EXT4_OS_LINUX		0
1085 #define EXT4_OS_HURD		1
1086 #define EXT4_OS_MASIX		2
1087 #define EXT4_OS_FREEBSD		3
1088 #define EXT4_OS_LITES		4
1089 
1090 /*
1091  * Revision levels
1092  */
1093 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1094 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1095 
1096 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1097 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1098 
1099 #define EXT4_GOOD_OLD_INODE_SIZE 128
1100 
1101 /*
1102  * Feature set definitions
1103  */
1104 
1105 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1106 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1107 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1108 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1109 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1110 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1111 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1112 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1113 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1114 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1115 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1116 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1117 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1118 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1119 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1120 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1121 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1122 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1123 
1124 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1125 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1126 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1127 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1128 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1129 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1130 
1131 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1132 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1133 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1134 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1135 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1136 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1137 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1138 
1139 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1140 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1141 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1142 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1143 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1144 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1145 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1146 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1147 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1148 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1149 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1150 
1151 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1152 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1153 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1154 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1155 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1156 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1157 					 EXT4_FEATURE_INCOMPAT_FLEX_BG)
1158 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1159 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1160 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1161 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1162 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1163 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1164 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
1165 
1166 /*
1167  * Default values for user and/or group using reserved blocks
1168  */
1169 #define	EXT4_DEF_RESUID		0
1170 #define	EXT4_DEF_RESGID		0
1171 
1172 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1173 
1174 /*
1175  * Default mount options
1176  */
1177 #define EXT4_DEFM_DEBUG		0x0001
1178 #define EXT4_DEFM_BSDGROUPS	0x0002
1179 #define EXT4_DEFM_XATTR_USER	0x0004
1180 #define EXT4_DEFM_ACL		0x0008
1181 #define EXT4_DEFM_UID16		0x0010
1182 #define EXT4_DEFM_JMODE		0x0060
1183 #define EXT4_DEFM_JMODE_DATA	0x0020
1184 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1185 #define EXT4_DEFM_JMODE_WBACK	0x0060
1186 
1187 /*
1188  * Default journal batch times
1189  */
1190 #define EXT4_DEF_MIN_BATCH_TIME	0
1191 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1192 
1193 /*
1194  * Minimum number of groups in a flexgroup before we separate out
1195  * directories into the first block group of a flexgroup
1196  */
1197 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1198 
1199 /*
1200  * Structure of a directory entry
1201  */
1202 #define EXT4_NAME_LEN 255
1203 
1204 struct ext4_dir_entry {
1205 	__le32	inode;			/* Inode number */
1206 	__le16	rec_len;		/* Directory entry length */
1207 	__le16	name_len;		/* Name length */
1208 	char	name[EXT4_NAME_LEN];	/* File name */
1209 };
1210 
1211 /*
1212  * The new version of the directory entry.  Since EXT4 structures are
1213  * stored in intel byte order, and the name_len field could never be
1214  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1215  * file_type field.
1216  */
1217 struct ext4_dir_entry_2 {
1218 	__le32	inode;			/* Inode number */
1219 	__le16	rec_len;		/* Directory entry length */
1220 	__u8	name_len;		/* Name length */
1221 	__u8	file_type;
1222 	char	name[EXT4_NAME_LEN];	/* File name */
1223 };
1224 
1225 /*
1226  * Ext4 directory file types.  Only the low 3 bits are used.  The
1227  * other bits are reserved for now.
1228  */
1229 #define EXT4_FT_UNKNOWN		0
1230 #define EXT4_FT_REG_FILE	1
1231 #define EXT4_FT_DIR		2
1232 #define EXT4_FT_CHRDEV		3
1233 #define EXT4_FT_BLKDEV		4
1234 #define EXT4_FT_FIFO		5
1235 #define EXT4_FT_SOCK		6
1236 #define EXT4_FT_SYMLINK		7
1237 
1238 #define EXT4_FT_MAX		8
1239 
1240 /*
1241  * EXT4_DIR_PAD defines the directory entries boundaries
1242  *
1243  * NOTE: It must be a multiple of 4
1244  */
1245 #define EXT4_DIR_PAD			4
1246 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1247 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1248 					 ~EXT4_DIR_ROUND)
1249 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1250 
1251 /*
1252  * Hash Tree Directory indexing
1253  * (c) Daniel Phillips, 2001
1254  */
1255 
1256 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1257 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1258 		      (EXT4_I(dir)->i_flags & EXT4_INDEX_FL))
1259 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1260 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1261 
1262 /* Legal values for the dx_root hash_version field: */
1263 
1264 #define DX_HASH_LEGACY		0
1265 #define DX_HASH_HALF_MD4	1
1266 #define DX_HASH_TEA		2
1267 #define DX_HASH_LEGACY_UNSIGNED	3
1268 #define DX_HASH_HALF_MD4_UNSIGNED	4
1269 #define DX_HASH_TEA_UNSIGNED		5
1270 
1271 #ifdef __KERNEL__
1272 
1273 /* hash info structure used by the directory hash */
1274 struct dx_hash_info
1275 {
1276 	u32		hash;
1277 	u32		minor_hash;
1278 	int		hash_version;
1279 	u32		*seed;
1280 };
1281 
1282 #define EXT4_HTREE_EOF	0x7fffffff
1283 
1284 /*
1285  * Control parameters used by ext4_htree_next_block
1286  */
1287 #define HASH_NB_ALWAYS		1
1288 
1289 
1290 /*
1291  * Describe an inode's exact location on disk and in memory
1292  */
1293 struct ext4_iloc
1294 {
1295 	struct buffer_head *bh;
1296 	unsigned long offset;
1297 	ext4_group_t block_group;
1298 };
1299 
1300 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1301 {
1302 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1303 }
1304 
1305 /*
1306  * This structure is stuffed into the struct file's private_data field
1307  * for directories.  It is where we put information so that we can do
1308  * readdir operations in hash tree order.
1309  */
1310 struct dir_private_info {
1311 	struct rb_root	root;
1312 	struct rb_node	*curr_node;
1313 	struct fname	*extra_fname;
1314 	loff_t		last_pos;
1315 	__u32		curr_hash;
1316 	__u32		curr_minor_hash;
1317 	__u32		next_hash;
1318 };
1319 
1320 /* calculate the first block number of the group */
1321 static inline ext4_fsblk_t
1322 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1323 {
1324 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1325 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1326 }
1327 
1328 /*
1329  * Special error return code only used by dx_probe() and its callers.
1330  */
1331 #define ERR_BAD_DX_DIR	-75000
1332 
1333 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1334 			ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1335 
1336 extern struct proc_dir_entry *ext4_proc_root;
1337 
1338 /*
1339  * Function prototypes
1340  */
1341 
1342 /*
1343  * Ok, these declarations are also in <linux/kernel.h> but none of the
1344  * ext4 source programs needs to include it so they are duplicated here.
1345  */
1346 # define NORET_TYPE	/**/
1347 # define ATTRIB_NORET	__attribute__((noreturn))
1348 # define NORET_AND	noreturn,
1349 
1350 /* bitmap.c */
1351 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
1352 
1353 /* balloc.c */
1354 extern unsigned int ext4_block_group(struct super_block *sb,
1355 			ext4_fsblk_t blocknr);
1356 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1357 			ext4_fsblk_t blocknr);
1358 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1359 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1360 			ext4_group_t group);
1361 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1362 			ext4_fsblk_t goal, unsigned long *count, int *errp);
1363 extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1364 extern int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1365 extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
1366 				ext4_fsblk_t block, unsigned long count);
1367 extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
1368 extern void ext4_check_blocks_bitmap(struct super_block *);
1369 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1370 						    ext4_group_t block_group,
1371 						    struct buffer_head ** bh);
1372 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1373 struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1374 				      ext4_group_t block_group);
1375 extern unsigned ext4_init_block_bitmap(struct super_block *sb,
1376 				       struct buffer_head *bh,
1377 				       ext4_group_t group,
1378 				       struct ext4_group_desc *desc);
1379 #define ext4_free_blocks_after_init(sb, group, desc)			\
1380 		ext4_init_block_bitmap(sb, NULL, group, desc)
1381 
1382 /* dir.c */
1383 extern int ext4_check_dir_entry(const char *, struct inode *,
1384 				struct ext4_dir_entry_2 *,
1385 				struct buffer_head *, unsigned int);
1386 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1387 				    __u32 minor_hash,
1388 				    struct ext4_dir_entry_2 *dirent);
1389 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1390 
1391 /* fsync.c */
1392 extern int ext4_sync_file(struct file *, struct dentry *, int);
1393 
1394 /* hash.c */
1395 extern int ext4fs_dirhash(const char *name, int len, struct
1396 			  dx_hash_info *hinfo);
1397 
1398 /* ialloc.c */
1399 extern struct inode *ext4_new_inode(handle_t *, struct inode *, int,
1400 				    const struct qstr *qstr, __u32 goal);
1401 extern void ext4_free_inode(handle_t *, struct inode *);
1402 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1403 extern unsigned long ext4_count_free_inodes(struct super_block *);
1404 extern unsigned long ext4_count_dirs(struct super_block *);
1405 extern void ext4_check_inodes_bitmap(struct super_block *);
1406 extern unsigned ext4_init_inode_bitmap(struct super_block *sb,
1407 				       struct buffer_head *bh,
1408 				       ext4_group_t group,
1409 				       struct ext4_group_desc *desc);
1410 extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1411 
1412 /* mballoc.c */
1413 extern long ext4_mb_stats;
1414 extern long ext4_mb_max_to_scan;
1415 extern int ext4_mb_init(struct super_block *, int);
1416 extern int ext4_mb_release(struct super_block *);
1417 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1418 				struct ext4_allocation_request *, int *);
1419 extern int ext4_mb_reserve_blocks(struct super_block *, int);
1420 extern void ext4_discard_preallocations(struct inode *);
1421 extern int __init init_ext4_mballoc(void);
1422 extern void exit_ext4_mballoc(void);
1423 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1424 			     struct buffer_head *bh, ext4_fsblk_t block,
1425 			     unsigned long count, int flags);
1426 extern int ext4_mb_add_groupinfo(struct super_block *sb,
1427 		ext4_group_t i, struct ext4_group_desc *desc);
1428 extern int ext4_mb_get_buddy_cache_lock(struct super_block *, ext4_group_t);
1429 extern void ext4_mb_put_buddy_cache_lock(struct super_block *,
1430 						ext4_group_t, int);
1431 /* inode.c */
1432 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1433 						ext4_lblk_t, int, int *);
1434 struct buffer_head *ext4_bread(handle_t *, struct inode *,
1435 						ext4_lblk_t, int, int *);
1436 int ext4_get_block(struct inode *inode, sector_t iblock,
1437 				struct buffer_head *bh_result, int create);
1438 
1439 extern struct inode *ext4_iget(struct super_block *, unsigned long);
1440 extern int  ext4_write_inode(struct inode *, int);
1441 extern int  ext4_setattr(struct dentry *, struct iattr *);
1442 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1443 				struct kstat *stat);
1444 extern void ext4_delete_inode(struct inode *);
1445 extern int  ext4_sync_inode(handle_t *, struct inode *);
1446 extern void ext4_dirty_inode(struct inode *);
1447 extern int ext4_change_inode_journal_flag(struct inode *, int);
1448 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1449 extern int ext4_can_truncate(struct inode *inode);
1450 extern void ext4_truncate(struct inode *);
1451 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
1452 extern void ext4_set_inode_flags(struct inode *);
1453 extern void ext4_get_inode_flags(struct ext4_inode_info *);
1454 extern int ext4_alloc_da_blocks(struct inode *inode);
1455 extern void ext4_set_aops(struct inode *inode);
1456 extern int ext4_writepage_trans_blocks(struct inode *);
1457 extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);
1458 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1459 extern int ext4_block_truncate_page(handle_t *handle,
1460 		struct address_space *mapping, loff_t from);
1461 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1462 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
1463 extern int flush_aio_dio_completed_IO(struct inode *inode);
1464 extern void ext4_da_update_reserve_space(struct inode *inode,
1465 					int used, int quota_claim);
1466 /* ioctl.c */
1467 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1468 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1469 
1470 /* migrate.c */
1471 extern int ext4_ext_migrate(struct inode *);
1472 
1473 /* namei.c */
1474 extern unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize);
1475 extern __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize);
1476 extern int ext4_orphan_add(handle_t *, struct inode *);
1477 extern int ext4_orphan_del(handle_t *, struct inode *);
1478 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1479 				__u32 start_minor_hash, __u32 *next_hash);
1480 
1481 /* resize.c */
1482 extern int ext4_group_add(struct super_block *sb,
1483 				struct ext4_new_group_data *input);
1484 extern int ext4_group_extend(struct super_block *sb,
1485 				struct ext4_super_block *es,
1486 				ext4_fsblk_t n_blocks_count);
1487 
1488 /* super.c */
1489 extern void ext4_error(struct super_block *, const char *, const char *, ...)
1490 	__attribute__ ((format (printf, 3, 4)));
1491 extern void __ext4_std_error(struct super_block *, const char *, int);
1492 extern void ext4_abort(struct super_block *, const char *, const char *, ...)
1493 	__attribute__ ((format (printf, 3, 4)));
1494 extern void ext4_warning(struct super_block *, const char *, const char *, ...)
1495 	__attribute__ ((format (printf, 3, 4)));
1496 extern void ext4_msg(struct super_block *, const char *, const char *, ...)
1497 	__attribute__ ((format (printf, 3, 4)));
1498 extern void ext4_grp_locked_error(struct super_block *, ext4_group_t,
1499 				const char *, const char *, ...)
1500 	__attribute__ ((format (printf, 4, 5)));
1501 extern void ext4_update_dynamic_rev(struct super_block *sb);
1502 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1503 					__u32 compat);
1504 extern int ext4_update_rocompat_feature(handle_t *handle,
1505 					struct super_block *sb,	__u32 rocompat);
1506 extern int ext4_update_incompat_feature(handle_t *handle,
1507 					struct super_block *sb,	__u32 incompat);
1508 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1509 				      struct ext4_group_desc *bg);
1510 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1511 				      struct ext4_group_desc *bg);
1512 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1513 				     struct ext4_group_desc *bg);
1514 extern __u32 ext4_free_blks_count(struct super_block *sb,
1515 				struct ext4_group_desc *bg);
1516 extern __u32 ext4_free_inodes_count(struct super_block *sb,
1517 				 struct ext4_group_desc *bg);
1518 extern __u32 ext4_used_dirs_count(struct super_block *sb,
1519 				struct ext4_group_desc *bg);
1520 extern __u32 ext4_itable_unused_count(struct super_block *sb,
1521 				   struct ext4_group_desc *bg);
1522 extern void ext4_block_bitmap_set(struct super_block *sb,
1523 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1524 extern void ext4_inode_bitmap_set(struct super_block *sb,
1525 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1526 extern void ext4_inode_table_set(struct super_block *sb,
1527 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
1528 extern void ext4_free_blks_set(struct super_block *sb,
1529 			       struct ext4_group_desc *bg, __u32 count);
1530 extern void ext4_free_inodes_set(struct super_block *sb,
1531 				struct ext4_group_desc *bg, __u32 count);
1532 extern void ext4_used_dirs_set(struct super_block *sb,
1533 				struct ext4_group_desc *bg, __u32 count);
1534 extern void ext4_itable_unused_set(struct super_block *sb,
1535 				   struct ext4_group_desc *bg, __u32 count);
1536 extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
1537 				   struct ext4_group_desc *gdp);
1538 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
1539 				       struct ext4_group_desc *gdp);
1540 
1541 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
1542 {
1543 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
1544 		le32_to_cpu(es->s_blocks_count_lo);
1545 }
1546 
1547 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
1548 {
1549 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
1550 		le32_to_cpu(es->s_r_blocks_count_lo);
1551 }
1552 
1553 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
1554 {
1555 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
1556 		le32_to_cpu(es->s_free_blocks_count_lo);
1557 }
1558 
1559 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
1560 					 ext4_fsblk_t blk)
1561 {
1562 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
1563 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
1564 }
1565 
1566 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
1567 					      ext4_fsblk_t blk)
1568 {
1569 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
1570 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
1571 }
1572 
1573 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
1574 					   ext4_fsblk_t blk)
1575 {
1576 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
1577 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
1578 }
1579 
1580 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
1581 {
1582 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
1583 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
1584 			le32_to_cpu(raw_inode->i_size_lo);
1585 	else
1586 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
1587 }
1588 
1589 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
1590 {
1591 	raw_inode->i_size_lo = cpu_to_le32(i_size);
1592 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
1593 }
1594 
1595 static inline
1596 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
1597 					    ext4_group_t group)
1598 {
1599 	 struct ext4_group_info ***grp_info;
1600 	 long indexv, indexh;
1601 	 grp_info = EXT4_SB(sb)->s_group_info;
1602 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
1603 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
1604 	 return grp_info[indexv][indexh];
1605 }
1606 
1607 /*
1608  * Reading s_groups_count requires using smp_rmb() afterwards.  See
1609  * the locking protocol documented in the comments of ext4_group_add()
1610  * in resize.c
1611  */
1612 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
1613 {
1614 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
1615 
1616 	smp_rmb();
1617 	return ngroups;
1618 }
1619 
1620 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
1621 					     ext4_group_t block_group)
1622 {
1623 	return block_group >> sbi->s_log_groups_per_flex;
1624 }
1625 
1626 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
1627 {
1628 	return 1 << sbi->s_log_groups_per_flex;
1629 }
1630 
1631 #define ext4_std_error(sb, errno)				\
1632 do {								\
1633 	if ((errno))						\
1634 		__ext4_std_error((sb), __func__, (errno));	\
1635 } while (0)
1636 
1637 #ifdef CONFIG_SMP
1638 /* Each CPU can accumulate percpu_counter_batch blocks in their local
1639  * counters. So we need to make sure we have free blocks more
1640  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
1641  */
1642 #define EXT4_FREEBLOCKS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
1643 #else
1644 #define EXT4_FREEBLOCKS_WATERMARK 0
1645 #endif
1646 
1647 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
1648 {
1649 	/*
1650 	 * XXX: replace with spinlock if seen contended -bzzz
1651 	 */
1652 	down_write(&EXT4_I(inode)->i_data_sem);
1653 	if (newsize > EXT4_I(inode)->i_disksize)
1654 		EXT4_I(inode)->i_disksize = newsize;
1655 	up_write(&EXT4_I(inode)->i_data_sem);
1656 	return ;
1657 }
1658 
1659 struct ext4_group_info {
1660 	unsigned long   bb_state;
1661 	struct rb_root  bb_free_root;
1662 	ext4_grpblk_t	bb_first_free;	/* first free block */
1663 	ext4_grpblk_t	bb_free;	/* total free blocks */
1664 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
1665 	struct          list_head bb_prealloc_list;
1666 #ifdef DOUBLE_CHECK
1667 	void            *bb_bitmap;
1668 #endif
1669 	struct rw_semaphore alloc_sem;
1670 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
1671 					 * regions, index is order.
1672 					 * bb_counters[3] = 5 means
1673 					 * 5 free 8-block regions. */
1674 };
1675 
1676 #define EXT4_GROUP_INFO_NEED_INIT_BIT	0
1677 
1678 #define EXT4_MB_GRP_NEED_INIT(grp)	\
1679 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
1680 
1681 #define EXT4_MAX_CONTENTION		8
1682 #define EXT4_CONTENTION_THRESHOLD	2
1683 
1684 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
1685 					      ext4_group_t group)
1686 {
1687 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
1688 }
1689 
1690 /*
1691  * Returns true if the filesystem is busy enough that attempts to
1692  * access the block group locks has run into contention.
1693  */
1694 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
1695 {
1696 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
1697 }
1698 
1699 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
1700 {
1701 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
1702 	if (spin_trylock(lock))
1703 		/*
1704 		 * We're able to grab the lock right away, so drop the
1705 		 * lock contention counter.
1706 		 */
1707 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
1708 	else {
1709 		/*
1710 		 * The lock is busy, so bump the contention counter,
1711 		 * and then wait on the spin lock.
1712 		 */
1713 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
1714 				  EXT4_MAX_CONTENTION);
1715 		spin_lock(lock);
1716 	}
1717 }
1718 
1719 static inline void ext4_unlock_group(struct super_block *sb,
1720 					ext4_group_t group)
1721 {
1722 	spin_unlock(ext4_group_lock_ptr(sb, group));
1723 }
1724 
1725 /*
1726  * Inodes and files operations
1727  */
1728 
1729 /* dir.c */
1730 extern const struct file_operations ext4_dir_operations;
1731 
1732 /* file.c */
1733 extern const struct inode_operations ext4_file_inode_operations;
1734 extern const struct file_operations ext4_file_operations;
1735 
1736 /* namei.c */
1737 extern const struct inode_operations ext4_dir_inode_operations;
1738 extern const struct inode_operations ext4_special_inode_operations;
1739 extern struct dentry *ext4_get_parent(struct dentry *child);
1740 
1741 /* symlink.c */
1742 extern const struct inode_operations ext4_symlink_inode_operations;
1743 extern const struct inode_operations ext4_fast_symlink_inode_operations;
1744 
1745 /* block_validity */
1746 extern void ext4_release_system_zone(struct super_block *sb);
1747 extern int ext4_setup_system_zone(struct super_block *sb);
1748 extern int __init init_ext4_system_zone(void);
1749 extern void exit_ext4_system_zone(void);
1750 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
1751 				 ext4_fsblk_t start_blk,
1752 				 unsigned int count);
1753 
1754 /* extents.c */
1755 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
1756 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
1757 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
1758 				       int chunk);
1759 extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
1760 			       ext4_lblk_t iblock, unsigned int max_blocks,
1761 			       struct buffer_head *bh_result, int flags);
1762 extern void ext4_ext_truncate(struct inode *);
1763 extern void ext4_ext_init(struct super_block *);
1764 extern void ext4_ext_release(struct super_block *);
1765 extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
1766 			  loff_t len);
1767 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
1768 			  ssize_t len);
1769 extern int ext4_get_blocks(handle_t *handle, struct inode *inode,
1770 			   sector_t block, unsigned int max_blocks,
1771 			   struct buffer_head *bh, int flags);
1772 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1773 			__u64 start, __u64 len);
1774 /* move_extent.c */
1775 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
1776 			     __u64 start_orig, __u64 start_donor,
1777 			     __u64 len, __u64 *moved_len);
1778 
1779 
1780 /*
1781  * Add new method to test wether block and inode bitmaps are properly
1782  * initialized. With uninit_bg reading the block from disk is not enough
1783  * to mark the bitmap uptodate. We need to also zero-out the bitmap
1784  */
1785 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
1786 
1787 static inline int bitmap_uptodate(struct buffer_head *bh)
1788 {
1789 	return (buffer_uptodate(bh) &&
1790 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
1791 }
1792 static inline void set_bitmap_uptodate(struct buffer_head *bh)
1793 {
1794 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
1795 }
1796 
1797 #endif	/* __KERNEL__ */
1798 
1799 #endif	/* _EXT4_H */
1800