xref: /linux/fs/ext4/ext4.h (revision 47902f3611b392209e2a412bf7ec02dca95e666d)
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  * For delayed allocation tracking
130  */
131 struct mpage_da_data {
132 	struct inode *inode;
133 	sector_t b_blocknr;		/* start block number of extent */
134 	size_t b_size;			/* size of extent */
135 	unsigned long b_state;		/* state of the extent */
136 	unsigned long first_page, next_page;	/* extent of pages */
137 	struct writeback_control *wbc;
138 	int io_done;
139 	int pages_written;
140 	int retval;
141 };
142 #define	EXT4_IO_UNWRITTEN	0x1
143 typedef struct ext4_io_end {
144 	struct list_head	list;		/* per-file finished AIO list */
145 	struct inode		*inode;		/* file being written to */
146 	unsigned int		flag;		/* unwritten or not */
147 	struct page		*page;		/* page struct for buffer write */
148 	loff_t			offset;		/* offset in the file */
149 	ssize_t			size;		/* size of the extent */
150 	struct work_struct	work;		/* data work queue */
151 } ext4_io_end_t;
152 
153 /*
154  * Special inodes numbers
155  */
156 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
157 #define EXT4_ROOT_INO		 2	/* Root inode */
158 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
159 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
160 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
161 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
162 
163 /* First non-reserved inode for old ext4 filesystems */
164 #define EXT4_GOOD_OLD_FIRST_INO	11
165 
166 /*
167  * Maximal count of links to a file
168  */
169 #define EXT4_LINK_MAX		65000
170 
171 /*
172  * Macro-instructions used to manage several block sizes
173  */
174 #define EXT4_MIN_BLOCK_SIZE		1024
175 #define	EXT4_MAX_BLOCK_SIZE		65536
176 #define EXT4_MIN_BLOCK_LOG_SIZE		10
177 #ifdef __KERNEL__
178 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
179 #else
180 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
181 #endif
182 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
183 #ifdef __KERNEL__
184 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
185 #else
186 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
187 #endif
188 #ifdef __KERNEL__
189 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
190 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
191 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
192 #else
193 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
194 				 EXT4_GOOD_OLD_INODE_SIZE : \
195 				 (s)->s_inode_size)
196 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
197 				 EXT4_GOOD_OLD_FIRST_INO : \
198 				 (s)->s_first_ino)
199 #endif
200 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
201 
202 /*
203  * Structure of a blocks group descriptor
204  */
205 struct ext4_group_desc
206 {
207 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
208 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
209 	__le32	bg_inode_table_lo;	/* Inodes table block */
210 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
211 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
212 	__le16	bg_used_dirs_count_lo;	/* Directories count */
213 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
214 	__u32	bg_reserved[2];		/* Likely block/inode bitmap checksum */
215 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
216 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
217 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
218 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
219 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
220 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
221 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
222 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
223 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
224 	__u32	bg_reserved2[3];
225 };
226 
227 /*
228  * Structure of a flex block group info
229  */
230 
231 struct flex_groups {
232 	atomic_t free_inodes;
233 	atomic_t free_blocks;
234 	atomic_t used_dirs;
235 };
236 
237 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
238 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
239 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
240 
241 /*
242  * Macro-instructions used to manage group descriptors
243  */
244 #define EXT4_MIN_DESC_SIZE		32
245 #define EXT4_MIN_DESC_SIZE_64BIT	64
246 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
247 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
248 #ifdef __KERNEL__
249 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
250 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
251 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
252 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
253 #else
254 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
255 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
256 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
257 #endif
258 
259 /*
260  * Constants relative to the data blocks
261  */
262 #define	EXT4_NDIR_BLOCKS		12
263 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
264 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
265 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
266 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
267 
268 /*
269  * Inode flags
270  */
271 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
272 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
273 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
274 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
275 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
276 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
277 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
278 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
279 /* Reserved for compression usage... */
280 #define EXT4_DIRTY_FL			0x00000100
281 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
282 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
283 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
284 /* End compression flags --- maybe not all used */
285 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
286 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
287 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
288 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
289 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
290 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
291 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
292 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
293 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
294 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
295 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
296 
297 #define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
298 #define EXT4_FL_USER_MODIFIABLE		0x004B80FF /* User modifiable flags */
299 
300 /* Flags that should be inherited by new inodes from their parent. */
301 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
302 			   EXT4_SYNC_FL | EXT4_IMMUTABLE_FL | EXT4_APPEND_FL |\
303 			   EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
304 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
305 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
306 
307 /* Flags that are appropriate for regular files (all but dir-specific ones). */
308 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
309 
310 /* Flags that are appropriate for non-directories/regular files. */
311 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
312 
313 /* Mask out flags that are inappropriate for the given type of inode. */
314 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
315 {
316 	if (S_ISDIR(mode))
317 		return flags;
318 	else if (S_ISREG(mode))
319 		return flags & EXT4_REG_FLMASK;
320 	else
321 		return flags & EXT4_OTHER_FLMASK;
322 }
323 
324 /* Used to pass group descriptor data when online resize is done */
325 struct ext4_new_group_input {
326 	__u32 group;		/* Group number for this data */
327 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
328 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
329 	__u64 inode_table;	/* Absolute block number of inode table start */
330 	__u32 blocks_count;	/* Total number of blocks in this group */
331 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
332 	__u16 unused;
333 };
334 
335 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
336 struct ext4_new_group_data {
337 	__u32 group;
338 	__u64 block_bitmap;
339 	__u64 inode_bitmap;
340 	__u64 inode_table;
341 	__u32 blocks_count;
342 	__u16 reserved_blocks;
343 	__u16 unused;
344 	__u32 free_blocks_count;
345 };
346 
347 /*
348  * Flags used by ext4_get_blocks()
349  */
350 	/* Allocate any needed blocks and/or convert an unitialized
351 	   extent to be an initialized ext4 */
352 #define EXT4_GET_BLOCKS_CREATE			0x0001
353 	/* Request the creation of an unitialized extent */
354 #define EXT4_GET_BLOCKS_UNINIT_EXT		0x0002
355 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\
356 						 EXT4_GET_BLOCKS_CREATE)
357 	/* Caller is from the delayed allocation writeout path,
358 	   so set the magic i_delalloc_reserve_flag after taking the
359 	   inode allocation semaphore for */
360 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
361 	/* caller is from the direct IO path, request to creation of an
362 	unitialized extents if not allocated, split the uninitialized
363 	extent if blocks has been preallocated already*/
364 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
365 #define EXT4_GET_BLOCKS_CONVERT			0x0010
366 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
367 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
368 	/* Convert extent to initialized after IO complete */
369 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
370 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
371 
372 /*
373  * Flags used by ext4_free_blocks
374  */
375 #define EXT4_FREE_BLOCKS_METADATA	0x0001
376 #define EXT4_FREE_BLOCKS_FORGET		0x0002
377 #define EXT4_FREE_BLOCKS_VALIDATED	0x0004
378 
379 /*
380  * ioctl commands
381  */
382 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
383 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
384 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
385 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
386 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
387 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
388 #ifdef CONFIG_JBD2_DEBUG
389 #define EXT4_IOC_WAIT_FOR_READONLY	_IOR('f', 99, long)
390 #endif
391 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
392 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
393 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
394 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
395 #define EXT4_IOC_MIGRATE		_IO('f', 9)
396  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
397  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
398 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
399 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
400 
401 /*
402  * ioctl commands in 32 bit emulation
403  */
404 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
405 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
406 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
407 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
408 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
409 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
410 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
411 #ifdef CONFIG_JBD2_DEBUG
412 #define EXT4_IOC32_WAIT_FOR_READONLY	_IOR('f', 99, int)
413 #endif
414 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
415 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
416 
417 
418 /*
419  *  Mount options
420  */
421 struct ext4_mount_options {
422 	unsigned long s_mount_opt;
423 	uid_t s_resuid;
424 	gid_t s_resgid;
425 	unsigned long s_commit_interval;
426 	u32 s_min_batch_time, s_max_batch_time;
427 #ifdef CONFIG_QUOTA
428 	int s_jquota_fmt;
429 	char *s_qf_names[MAXQUOTAS];
430 #endif
431 };
432 
433 /* Max physical block we can addres w/o extents */
434 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
435 
436 /*
437  * Structure of an inode on the disk
438  */
439 struct ext4_inode {
440 	__le16	i_mode;		/* File mode */
441 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
442 	__le32	i_size_lo;	/* Size in bytes */
443 	__le32	i_atime;	/* Access time */
444 	__le32	i_ctime;	/* Inode Change time */
445 	__le32	i_mtime;	/* Modification time */
446 	__le32	i_dtime;	/* Deletion Time */
447 	__le16	i_gid;		/* Low 16 bits of Group Id */
448 	__le16	i_links_count;	/* Links count */
449 	__le32	i_blocks_lo;	/* Blocks count */
450 	__le32	i_flags;	/* File flags */
451 	union {
452 		struct {
453 			__le32  l_i_version;
454 		} linux1;
455 		struct {
456 			__u32  h_i_translator;
457 		} hurd1;
458 		struct {
459 			__u32  m_i_reserved1;
460 		} masix1;
461 	} osd1;				/* OS dependent 1 */
462 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
463 	__le32	i_generation;	/* File version (for NFS) */
464 	__le32	i_file_acl_lo;	/* File ACL */
465 	__le32	i_size_high;
466 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
467 	union {
468 		struct {
469 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
470 			__le16	l_i_file_acl_high;
471 			__le16	l_i_uid_high;	/* these 2 fields */
472 			__le16	l_i_gid_high;	/* were reserved2[0] */
473 			__u32	l_i_reserved2;
474 		} linux2;
475 		struct {
476 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
477 			__u16	h_i_mode_high;
478 			__u16	h_i_uid_high;
479 			__u16	h_i_gid_high;
480 			__u32	h_i_author;
481 		} hurd2;
482 		struct {
483 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
484 			__le16	m_i_file_acl_high;
485 			__u32	m_i_reserved2[2];
486 		} masix2;
487 	} osd2;				/* OS dependent 2 */
488 	__le16	i_extra_isize;
489 	__le16	i_pad1;
490 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
491 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
492 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
493 	__le32  i_crtime;       /* File Creation time */
494 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
495 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
496 };
497 
498 struct move_extent {
499 	__u32 reserved;		/* should be zero */
500 	__u32 donor_fd;		/* donor file descriptor */
501 	__u64 orig_start;	/* logical start offset in block for orig */
502 	__u64 donor_start;	/* logical start offset in block for donor */
503 	__u64 len;		/* block length to be moved */
504 	__u64 moved_len;	/* moved block length */
505 };
506 
507 #define EXT4_EPOCH_BITS 2
508 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
509 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
510 
511 /*
512  * Extended fields will fit into an inode if the filesystem was formatted
513  * with large inodes (-I 256 or larger) and there are not currently any EAs
514  * consuming all of the available space. For new inodes we always reserve
515  * enough space for the kernel's known extended fields, but for inodes
516  * created with an old kernel this might not have been the case. None of
517  * the extended inode fields is critical for correct filesystem operation.
518  * This macro checks if a certain field fits in the inode. Note that
519  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
520  */
521 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
522 	((offsetof(typeof(*ext4_inode), field) +	\
523 	  sizeof((ext4_inode)->field))			\
524 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
525 	    (einode)->i_extra_isize))			\
526 
527 static inline __le32 ext4_encode_extra_time(struct timespec *time)
528 {
529        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
530 			   (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
531                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
532 }
533 
534 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
535 {
536        if (sizeof(time->tv_sec) > 4)
537 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
538 			       << 32;
539        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
540 }
541 
542 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
543 do {									       \
544 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
545 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
546 		(raw_inode)->xtime ## _extra =				       \
547 				ext4_encode_extra_time(&(inode)->xtime);       \
548 } while (0)
549 
550 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
551 do {									       \
552 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
553 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
554 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
555 		(raw_inode)->xtime ## _extra =				       \
556 				ext4_encode_extra_time(&(einode)->xtime);      \
557 } while (0)
558 
559 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
560 do {									       \
561 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
562 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
563 		ext4_decode_extra_time(&(inode)->xtime,			       \
564 				       raw_inode->xtime ## _extra);	       \
565 } while (0)
566 
567 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
568 do {									       \
569 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
570 		(einode)->xtime.tv_sec = 				       \
571 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
572 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
573 		ext4_decode_extra_time(&(einode)->xtime,		       \
574 				       raw_inode->xtime ## _extra);	       \
575 } while (0)
576 
577 #define i_disk_version osd1.linux1.l_i_version
578 
579 #if defined(__KERNEL__) || defined(__linux__)
580 #define i_reserved1	osd1.linux1.l_i_reserved1
581 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
582 #define i_blocks_high	osd2.linux2.l_i_blocks_high
583 #define i_uid_low	i_uid
584 #define i_gid_low	i_gid
585 #define i_uid_high	osd2.linux2.l_i_uid_high
586 #define i_gid_high	osd2.linux2.l_i_gid_high
587 #define i_reserved2	osd2.linux2.l_i_reserved2
588 
589 #elif defined(__GNU__)
590 
591 #define i_translator	osd1.hurd1.h_i_translator
592 #define i_uid_high	osd2.hurd2.h_i_uid_high
593 #define i_gid_high	osd2.hurd2.h_i_gid_high
594 #define i_author	osd2.hurd2.h_i_author
595 
596 #elif defined(__masix__)
597 
598 #define i_reserved1	osd1.masix1.m_i_reserved1
599 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
600 #define i_reserved2	osd2.masix2.m_i_reserved2
601 
602 #endif /* defined(__KERNEL__) || defined(__linux__) */
603 
604 /*
605  * storage for cached extent
606  */
607 struct ext4_ext_cache {
608 	ext4_fsblk_t	ec_start;
609 	ext4_lblk_t	ec_block;
610 	__u32		ec_len; /* must be 32bit to return holes */
611 	__u32		ec_type;
612 };
613 
614 /*
615  * fourth extended file system inode data in memory
616  */
617 struct ext4_inode_info {
618 	__le32	i_data[15];	/* unconverted */
619 	__u32	i_flags;
620 	ext4_fsblk_t	i_file_acl;
621 	__u32	i_dtime;
622 
623 	/*
624 	 * i_block_group is the number of the block group which contains
625 	 * this file's inode.  Constant across the lifetime of the inode,
626 	 * it is ued for making block allocation decisions - we try to
627 	 * place a file's data blocks near its inode block, and new inodes
628 	 * near to their parent directory's inode.
629 	 */
630 	ext4_group_t	i_block_group;
631 	unsigned long	i_state_flags;		/* Dynamic state flags */
632 
633 	ext4_lblk_t		i_dir_start_lookup;
634 #ifdef CONFIG_EXT4_FS_XATTR
635 	/*
636 	 * Extended attributes can be read independently of the main file
637 	 * data. Taking i_mutex even when reading would cause contention
638 	 * between readers of EAs and writers of regular file data, so
639 	 * instead we synchronize on xattr_sem when reading or changing
640 	 * EAs.
641 	 */
642 	struct rw_semaphore xattr_sem;
643 #endif
644 
645 	struct list_head i_orphan;	/* unlinked but open inodes */
646 
647 	/*
648 	 * i_disksize keeps track of what the inode size is ON DISK, not
649 	 * in memory.  During truncate, i_size is set to the new size by
650 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
651 	 * set i_disksize to 0 until the truncate is actually under way.
652 	 *
653 	 * The intent is that i_disksize always represents the blocks which
654 	 * are used by this file.  This allows recovery to restart truncate
655 	 * on orphans if we crash during truncate.  We actually write i_disksize
656 	 * into the on-disk inode when writing inodes out, instead of i_size.
657 	 *
658 	 * The only time when i_disksize and i_size may be different is when
659 	 * a truncate is in progress.  The only things which change i_disksize
660 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
661 	 */
662 	loff_t	i_disksize;
663 
664 	/*
665 	 * i_data_sem is for serialising ext4_truncate() against
666 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
667 	 * data tree are chopped off during truncate. We can't do that in
668 	 * ext4 because whenever we perform intermediate commits during
669 	 * truncate, the inode and all the metadata blocks *must* be in a
670 	 * consistent state which allows truncation of the orphans to restart
671 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
672 	 * by other means, so we have i_data_sem.
673 	 */
674 	struct rw_semaphore i_data_sem;
675 	struct inode vfs_inode;
676 	struct jbd2_inode jinode;
677 
678 	struct ext4_ext_cache i_cached_extent;
679 	/*
680 	 * File creation time. Its function is same as that of
681 	 * struct timespec i_{a,c,m}time in the generic inode.
682 	 */
683 	struct timespec i_crtime;
684 
685 	/* mballoc */
686 	struct list_head i_prealloc_list;
687 	spinlock_t i_prealloc_lock;
688 
689 	/* ialloc */
690 	ext4_group_t	i_last_alloc_group;
691 
692 	/* allocation reservation info for delalloc */
693 	unsigned int i_reserved_data_blocks;
694 	unsigned int i_reserved_meta_blocks;
695 	unsigned int i_allocated_meta_blocks;
696 	unsigned short i_delalloc_reserved_flag;
697 	sector_t i_da_metadata_calc_last_lblock;
698 	int i_da_metadata_calc_len;
699 
700 	/* on-disk additional length */
701 	__u16 i_extra_isize;
702 
703 	spinlock_t i_block_reservation_lock;
704 #ifdef CONFIG_QUOTA
705 	/* quota space reservation, managed internally by quota code */
706 	qsize_t i_reserved_quota;
707 #endif
708 
709 	/* completed IOs that might need unwritten extents handling */
710 	struct list_head i_completed_io_list;
711 	spinlock_t i_completed_io_lock;
712 	/* current io_end structure for async DIO write*/
713 	ext4_io_end_t *cur_aio_dio;
714 
715 	/*
716 	 * Transactions that contain inode's metadata needed to complete
717 	 * fsync and fdatasync, respectively.
718 	 */
719 	tid_t i_sync_tid;
720 	tid_t i_datasync_tid;
721 };
722 
723 /*
724  * File system states
725  */
726 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
727 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
728 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
729 
730 /*
731  * Misc. filesystem flags
732  */
733 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
734 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
735 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
736 
737 /*
738  * Mount flags
739  */
740 #define EXT4_MOUNT_OLDALLOC		0x00002  /* Don't use the new Orlov allocator */
741 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
742 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
743 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
744 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
745 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
746 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
747 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
748 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
749 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
750 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
751 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
752 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
753 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
754 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
755 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
756 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
757 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
758 #define EXT4_MOUNT_NOBH			0x40000 /* No bufferheads */
759 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
760 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
761 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
762 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
763 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
764 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
765 #define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
766 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
767 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
768 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
769 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
770 
771 #define clear_opt(o, opt)		o &= ~EXT4_MOUNT_##opt
772 #define set_opt(o, opt)			o |= EXT4_MOUNT_##opt
773 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
774 					 EXT4_MOUNT_##opt)
775 
776 #define ext4_set_bit			ext2_set_bit
777 #define ext4_set_bit_atomic		ext2_set_bit_atomic
778 #define ext4_clear_bit			ext2_clear_bit
779 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
780 #define ext4_test_bit			ext2_test_bit
781 #define ext4_find_first_zero_bit	ext2_find_first_zero_bit
782 #define ext4_find_next_zero_bit		ext2_find_next_zero_bit
783 #define ext4_find_next_bit		ext2_find_next_bit
784 
785 /*
786  * Maximal mount counts between two filesystem checks
787  */
788 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
789 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
790 
791 /*
792  * Behaviour when detecting errors
793  */
794 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
795 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
796 #define EXT4_ERRORS_PANIC		3	/* Panic */
797 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
798 
799 /*
800  * Structure of the super block
801  */
802 struct ext4_super_block {
803 /*00*/	__le32	s_inodes_count;		/* Inodes count */
804 	__le32	s_blocks_count_lo;	/* Blocks count */
805 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
806 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
807 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
808 	__le32	s_first_data_block;	/* First Data Block */
809 	__le32	s_log_block_size;	/* Block size */
810 	__le32	s_obso_log_frag_size;	/* Obsoleted fragment size */
811 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
812 	__le32	s_obso_frags_per_group;	/* Obsoleted fragments per group */
813 	__le32	s_inodes_per_group;	/* # Inodes per group */
814 	__le32	s_mtime;		/* Mount time */
815 /*30*/	__le32	s_wtime;		/* Write time */
816 	__le16	s_mnt_count;		/* Mount count */
817 	__le16	s_max_mnt_count;	/* Maximal mount count */
818 	__le16	s_magic;		/* Magic signature */
819 	__le16	s_state;		/* File system state */
820 	__le16	s_errors;		/* Behaviour when detecting errors */
821 	__le16	s_minor_rev_level;	/* minor revision level */
822 /*40*/	__le32	s_lastcheck;		/* time of last check */
823 	__le32	s_checkinterval;	/* max. time between checks */
824 	__le32	s_creator_os;		/* OS */
825 	__le32	s_rev_level;		/* Revision level */
826 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
827 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
828 	/*
829 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
830 	 *
831 	 * Note: the difference between the compatible feature set and
832 	 * the incompatible feature set is that if there is a bit set
833 	 * in the incompatible feature set that the kernel doesn't
834 	 * know about, it should refuse to mount the filesystem.
835 	 *
836 	 * e2fsck's requirements are more strict; if it doesn't know
837 	 * about a feature in either the compatible or incompatible
838 	 * feature set, it must abort and not try to meddle with
839 	 * things it doesn't understand...
840 	 */
841 	__le32	s_first_ino;		/* First non-reserved inode */
842 	__le16  s_inode_size;		/* size of inode structure */
843 	__le16	s_block_group_nr;	/* block group # of this superblock */
844 	__le32	s_feature_compat;	/* compatible feature set */
845 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
846 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
847 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
848 /*78*/	char	s_volume_name[16];	/* volume name */
849 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
850 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
851 	/*
852 	 * Performance hints.  Directory preallocation should only
853 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
854 	 */
855 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
856 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
857 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
858 	/*
859 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
860 	 */
861 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
862 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
863 	__le32	s_journal_dev;		/* device number of journal file */
864 	__le32	s_last_orphan;		/* start of list of inodes to delete */
865 	__le32	s_hash_seed[4];		/* HTREE hash seed */
866 	__u8	s_def_hash_version;	/* Default hash version to use */
867 	__u8	s_reserved_char_pad;
868 	__le16  s_desc_size;		/* size of group descriptor */
869 /*100*/	__le32	s_default_mount_opts;
870 	__le32	s_first_meta_bg;	/* First metablock block group */
871 	__le32	s_mkfs_time;		/* When the filesystem was created */
872 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
873 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
874 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
875 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
876 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
877 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
878 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
879 	__le32	s_flags;		/* Miscellaneous flags */
880 	__le16  s_raid_stride;		/* RAID stride */
881 	__le16  s_mmp_interval;         /* # seconds to wait in MMP checking */
882 	__le64  s_mmp_block;            /* Block for multi-mount protection */
883 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
884 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
885 	__u8	s_reserved_char_pad2;
886 	__le16  s_reserved_pad;
887 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
888 	__u32   s_reserved[160];        /* Padding to the end of the block */
889 };
890 
891 #ifdef __KERNEL__
892 
893 /*
894  * run-time mount flags
895  */
896 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
897 #define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
898 
899 /*
900  * fourth extended-fs super-block data in memory
901  */
902 struct ext4_sb_info {
903 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
904 	unsigned long s_inodes_per_block;/* Number of inodes per block */
905 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
906 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
907 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
908 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
909 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
910 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
911 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
912 	unsigned long s_overhead_last;  /* Last calculated overhead */
913 	unsigned long s_blocks_last;    /* Last seen block count */
914 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
915 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
916 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
917 	struct buffer_head **s_group_desc;
918 	unsigned int s_mount_opt;
919 	unsigned int s_mount_flags;
920 	ext4_fsblk_t s_sb_block;
921 	uid_t s_resuid;
922 	gid_t s_resgid;
923 	unsigned short s_mount_state;
924 	unsigned short s_pad;
925 	int s_addr_per_block_bits;
926 	int s_desc_per_block_bits;
927 	int s_inode_size;
928 	int s_first_ino;
929 	unsigned int s_inode_readahead_blks;
930 	unsigned int s_inode_goal;
931 	spinlock_t s_next_gen_lock;
932 	u32 s_next_generation;
933 	u32 s_hash_seed[4];
934 	int s_def_hash_version;
935 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
936 	struct percpu_counter s_freeblocks_counter;
937 	struct percpu_counter s_freeinodes_counter;
938 	struct percpu_counter s_dirs_counter;
939 	struct percpu_counter s_dirtyblocks_counter;
940 	struct blockgroup_lock *s_blockgroup_lock;
941 	struct proc_dir_entry *s_proc;
942 	struct kobject s_kobj;
943 	struct completion s_kobj_unregister;
944 
945 	/* Journaling */
946 	struct inode *s_journal_inode;
947 	struct journal_s *s_journal;
948 	struct list_head s_orphan;
949 	struct mutex s_orphan_lock;
950 	struct mutex s_resize_lock;
951 	unsigned long s_commit_interval;
952 	u32 s_max_batch_time;
953 	u32 s_min_batch_time;
954 	struct block_device *journal_bdev;
955 #ifdef CONFIG_JBD2_DEBUG
956 	struct timer_list turn_ro_timer;	/* For turning read-only (crash simulation) */
957 	wait_queue_head_t ro_wait_queue;	/* For people waiting for the fs to go read-only */
958 #endif
959 #ifdef CONFIG_QUOTA
960 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
961 	int s_jquota_fmt;			/* Format of quota to use */
962 #endif
963 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
964 	struct rb_root system_blks;
965 
966 #ifdef EXTENTS_STATS
967 	/* ext4 extents stats */
968 	unsigned long s_ext_min;
969 	unsigned long s_ext_max;
970 	unsigned long s_depth_max;
971 	spinlock_t s_ext_stats_lock;
972 	unsigned long s_ext_blocks;
973 	unsigned long s_ext_extents;
974 #endif
975 
976 	/* for buddy allocator */
977 	struct ext4_group_info ***s_group_info;
978 	struct inode *s_buddy_cache;
979 	long s_blocks_reserved;
980 	spinlock_t s_reserve_lock;
981 	spinlock_t s_md_lock;
982 	tid_t s_last_transaction;
983 	unsigned short *s_mb_offsets;
984 	unsigned int *s_mb_maxs;
985 
986 	/* tunables */
987 	unsigned long s_stripe;
988 	unsigned int s_mb_stream_request;
989 	unsigned int s_mb_max_to_scan;
990 	unsigned int s_mb_min_to_scan;
991 	unsigned int s_mb_stats;
992 	unsigned int s_mb_order2_reqs;
993 	unsigned int s_mb_group_prealloc;
994 	unsigned int s_max_writeback_mb_bump;
995 	/* where last allocation was done - for stream allocation */
996 	unsigned long s_mb_last_group;
997 	unsigned long s_mb_last_start;
998 
999 	/* stats for buddy allocator */
1000 	spinlock_t s_mb_pa_lock;
1001 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1002 	atomic_t s_bal_success;	/* we found long enough chunks */
1003 	atomic_t s_bal_allocated;	/* in blocks */
1004 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1005 	atomic_t s_bal_goals;	/* goal hits */
1006 	atomic_t s_bal_breaks;	/* too long searches */
1007 	atomic_t s_bal_2orders;	/* 2^order hits */
1008 	spinlock_t s_bal_lock;
1009 	unsigned long s_mb_buddies_generated;
1010 	unsigned long long s_mb_generation_time;
1011 	atomic_t s_mb_lost_chunks;
1012 	atomic_t s_mb_preallocated;
1013 	atomic_t s_mb_discarded;
1014 	atomic_t s_lock_busy;
1015 
1016 	/* locality groups */
1017 	struct ext4_locality_group __percpu *s_locality_groups;
1018 
1019 	/* for write statistics */
1020 	unsigned long s_sectors_written_start;
1021 	u64 s_kbytes_written;
1022 
1023 	unsigned int s_log_groups_per_flex;
1024 	struct flex_groups *s_flex_groups;
1025 
1026 	/* workqueue for dio unwritten */
1027 	struct workqueue_struct *dio_unwritten_wq;
1028 };
1029 
1030 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1031 {
1032 	return sb->s_fs_info;
1033 }
1034 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1035 {
1036 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1037 }
1038 
1039 static inline struct timespec ext4_current_time(struct inode *inode)
1040 {
1041 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1042 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1043 }
1044 
1045 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1046 {
1047 	return ino == EXT4_ROOT_INO ||
1048 		ino == EXT4_JOURNAL_INO ||
1049 		ino == EXT4_RESIZE_INO ||
1050 		(ino >= EXT4_FIRST_INO(sb) &&
1051 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1052 }
1053 
1054 /*
1055  * Inode dynamic state flags
1056  */
1057 enum {
1058 	EXT4_STATE_JDATA,		/* journaled data exists */
1059 	EXT4_STATE_NEW,			/* inode is newly created */
1060 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1061 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1062 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1063 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1064 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1065 };
1066 
1067 static inline int ext4_test_inode_state(struct inode *inode, int bit)
1068 {
1069 	return test_bit(bit, &EXT4_I(inode)->i_state_flags);
1070 }
1071 
1072 static inline void ext4_set_inode_state(struct inode *inode, int bit)
1073 {
1074 	set_bit(bit, &EXT4_I(inode)->i_state_flags);
1075 }
1076 
1077 static inline void ext4_clear_inode_state(struct inode *inode, int bit)
1078 {
1079 	clear_bit(bit, &EXT4_I(inode)->i_state_flags);
1080 }
1081 #else
1082 /* Assume that user mode programs are passing in an ext4fs superblock, not
1083  * a kernel struct super_block.  This will allow us to call the feature-test
1084  * macros from user land. */
1085 #define EXT4_SB(sb)	(sb)
1086 #endif
1087 
1088 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1089 
1090 /*
1091  * Codes for operating systems
1092  */
1093 #define EXT4_OS_LINUX		0
1094 #define EXT4_OS_HURD		1
1095 #define EXT4_OS_MASIX		2
1096 #define EXT4_OS_FREEBSD		3
1097 #define EXT4_OS_LITES		4
1098 
1099 /*
1100  * Revision levels
1101  */
1102 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1103 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1104 
1105 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1106 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1107 
1108 #define EXT4_GOOD_OLD_INODE_SIZE 128
1109 
1110 /*
1111  * Feature set definitions
1112  */
1113 
1114 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1115 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1116 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1117 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1118 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1119 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1120 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1121 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1122 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1123 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1124 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1125 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1126 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1127 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1128 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1129 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1130 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1131 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1132 
1133 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1134 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1135 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1136 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1137 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1138 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1139 
1140 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1141 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1142 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1143 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1144 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1145 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1146 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1147 
1148 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1149 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1150 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1151 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1152 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1153 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1154 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1155 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1156 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1157 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1158 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1159 
1160 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1161 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1162 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1163 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1164 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1165 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1166 					 EXT4_FEATURE_INCOMPAT_FLEX_BG)
1167 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1168 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1169 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1170 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1171 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1172 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1173 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
1174 
1175 /*
1176  * Default values for user and/or group using reserved blocks
1177  */
1178 #define	EXT4_DEF_RESUID		0
1179 #define	EXT4_DEF_RESGID		0
1180 
1181 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1182 
1183 /*
1184  * Default mount options
1185  */
1186 #define EXT4_DEFM_DEBUG		0x0001
1187 #define EXT4_DEFM_BSDGROUPS	0x0002
1188 #define EXT4_DEFM_XATTR_USER	0x0004
1189 #define EXT4_DEFM_ACL		0x0008
1190 #define EXT4_DEFM_UID16		0x0010
1191 #define EXT4_DEFM_JMODE		0x0060
1192 #define EXT4_DEFM_JMODE_DATA	0x0020
1193 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1194 #define EXT4_DEFM_JMODE_WBACK	0x0060
1195 
1196 /*
1197  * Default journal batch times
1198  */
1199 #define EXT4_DEF_MIN_BATCH_TIME	0
1200 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1201 
1202 /*
1203  * Minimum number of groups in a flexgroup before we separate out
1204  * directories into the first block group of a flexgroup
1205  */
1206 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1207 
1208 /*
1209  * Structure of a directory entry
1210  */
1211 #define EXT4_NAME_LEN 255
1212 
1213 struct ext4_dir_entry {
1214 	__le32	inode;			/* Inode number */
1215 	__le16	rec_len;		/* Directory entry length */
1216 	__le16	name_len;		/* Name length */
1217 	char	name[EXT4_NAME_LEN];	/* File name */
1218 };
1219 
1220 /*
1221  * The new version of the directory entry.  Since EXT4 structures are
1222  * stored in intel byte order, and the name_len field could never be
1223  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1224  * file_type field.
1225  */
1226 struct ext4_dir_entry_2 {
1227 	__le32	inode;			/* Inode number */
1228 	__le16	rec_len;		/* Directory entry length */
1229 	__u8	name_len;		/* Name length */
1230 	__u8	file_type;
1231 	char	name[EXT4_NAME_LEN];	/* File name */
1232 };
1233 
1234 /*
1235  * Ext4 directory file types.  Only the low 3 bits are used.  The
1236  * other bits are reserved for now.
1237  */
1238 #define EXT4_FT_UNKNOWN		0
1239 #define EXT4_FT_REG_FILE	1
1240 #define EXT4_FT_DIR		2
1241 #define EXT4_FT_CHRDEV		3
1242 #define EXT4_FT_BLKDEV		4
1243 #define EXT4_FT_FIFO		5
1244 #define EXT4_FT_SOCK		6
1245 #define EXT4_FT_SYMLINK		7
1246 
1247 #define EXT4_FT_MAX		8
1248 
1249 /*
1250  * EXT4_DIR_PAD defines the directory entries boundaries
1251  *
1252  * NOTE: It must be a multiple of 4
1253  */
1254 #define EXT4_DIR_PAD			4
1255 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1256 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1257 					 ~EXT4_DIR_ROUND)
1258 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1259 
1260 /*
1261  * Hash Tree Directory indexing
1262  * (c) Daniel Phillips, 2001
1263  */
1264 
1265 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1266 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1267 		      (EXT4_I(dir)->i_flags & EXT4_INDEX_FL))
1268 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1269 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1270 
1271 /* Legal values for the dx_root hash_version field: */
1272 
1273 #define DX_HASH_LEGACY		0
1274 #define DX_HASH_HALF_MD4	1
1275 #define DX_HASH_TEA		2
1276 #define DX_HASH_LEGACY_UNSIGNED	3
1277 #define DX_HASH_HALF_MD4_UNSIGNED	4
1278 #define DX_HASH_TEA_UNSIGNED		5
1279 
1280 #ifdef __KERNEL__
1281 
1282 /* hash info structure used by the directory hash */
1283 struct dx_hash_info
1284 {
1285 	u32		hash;
1286 	u32		minor_hash;
1287 	int		hash_version;
1288 	u32		*seed;
1289 };
1290 
1291 #define EXT4_HTREE_EOF	0x7fffffff
1292 
1293 /*
1294  * Control parameters used by ext4_htree_next_block
1295  */
1296 #define HASH_NB_ALWAYS		1
1297 
1298 
1299 /*
1300  * Describe an inode's exact location on disk and in memory
1301  */
1302 struct ext4_iloc
1303 {
1304 	struct buffer_head *bh;
1305 	unsigned long offset;
1306 	ext4_group_t block_group;
1307 };
1308 
1309 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1310 {
1311 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1312 }
1313 
1314 /*
1315  * This structure is stuffed into the struct file's private_data field
1316  * for directories.  It is where we put information so that we can do
1317  * readdir operations in hash tree order.
1318  */
1319 struct dir_private_info {
1320 	struct rb_root	root;
1321 	struct rb_node	*curr_node;
1322 	struct fname	*extra_fname;
1323 	loff_t		last_pos;
1324 	__u32		curr_hash;
1325 	__u32		curr_minor_hash;
1326 	__u32		next_hash;
1327 };
1328 
1329 /* calculate the first block number of the group */
1330 static inline ext4_fsblk_t
1331 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1332 {
1333 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1334 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1335 }
1336 
1337 /*
1338  * Special error return code only used by dx_probe() and its callers.
1339  */
1340 #define ERR_BAD_DX_DIR	-75000
1341 
1342 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1343 			ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1344 
1345 extern struct proc_dir_entry *ext4_proc_root;
1346 
1347 /*
1348  * Function prototypes
1349  */
1350 
1351 /*
1352  * Ok, these declarations are also in <linux/kernel.h> but none of the
1353  * ext4 source programs needs to include it so they are duplicated here.
1354  */
1355 # define NORET_TYPE	/**/
1356 # define ATTRIB_NORET	__attribute__((noreturn))
1357 # define NORET_AND	noreturn,
1358 
1359 /* bitmap.c */
1360 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
1361 
1362 /* balloc.c */
1363 extern unsigned int ext4_block_group(struct super_block *sb,
1364 			ext4_fsblk_t blocknr);
1365 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1366 			ext4_fsblk_t blocknr);
1367 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1368 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1369 			ext4_group_t group);
1370 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1371 			ext4_fsblk_t goal, unsigned long *count, int *errp);
1372 extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1373 extern int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1374 extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
1375 				ext4_fsblk_t block, unsigned long count);
1376 extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
1377 extern void ext4_check_blocks_bitmap(struct super_block *);
1378 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1379 						    ext4_group_t block_group,
1380 						    struct buffer_head ** bh);
1381 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1382 struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1383 				      ext4_group_t block_group);
1384 extern unsigned ext4_init_block_bitmap(struct super_block *sb,
1385 				       struct buffer_head *bh,
1386 				       ext4_group_t group,
1387 				       struct ext4_group_desc *desc);
1388 #define ext4_free_blocks_after_init(sb, group, desc)			\
1389 		ext4_init_block_bitmap(sb, NULL, group, desc)
1390 
1391 /* dir.c */
1392 extern int ext4_check_dir_entry(const char *, struct inode *,
1393 				struct ext4_dir_entry_2 *,
1394 				struct buffer_head *, unsigned int);
1395 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1396 				    __u32 minor_hash,
1397 				    struct ext4_dir_entry_2 *dirent);
1398 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1399 
1400 /* fsync.c */
1401 extern int ext4_sync_file(struct file *, struct dentry *, int);
1402 
1403 /* hash.c */
1404 extern int ext4fs_dirhash(const char *name, int len, struct
1405 			  dx_hash_info *hinfo);
1406 
1407 /* ialloc.c */
1408 extern struct inode *ext4_new_inode(handle_t *, struct inode *, int,
1409 				    const struct qstr *qstr, __u32 goal);
1410 extern void ext4_free_inode(handle_t *, struct inode *);
1411 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1412 extern unsigned long ext4_count_free_inodes(struct super_block *);
1413 extern unsigned long ext4_count_dirs(struct super_block *);
1414 extern void ext4_check_inodes_bitmap(struct super_block *);
1415 extern unsigned ext4_init_inode_bitmap(struct super_block *sb,
1416 				       struct buffer_head *bh,
1417 				       ext4_group_t group,
1418 				       struct ext4_group_desc *desc);
1419 extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1420 
1421 /* mballoc.c */
1422 extern long ext4_mb_stats;
1423 extern long ext4_mb_max_to_scan;
1424 extern int ext4_mb_init(struct super_block *, int);
1425 extern int ext4_mb_release(struct super_block *);
1426 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1427 				struct ext4_allocation_request *, int *);
1428 extern int ext4_mb_reserve_blocks(struct super_block *, int);
1429 extern void ext4_discard_preallocations(struct inode *);
1430 extern int __init init_ext4_mballoc(void);
1431 extern void exit_ext4_mballoc(void);
1432 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1433 			     struct buffer_head *bh, ext4_fsblk_t block,
1434 			     unsigned long count, int flags);
1435 extern int ext4_mb_add_groupinfo(struct super_block *sb,
1436 		ext4_group_t i, struct ext4_group_desc *desc);
1437 extern int ext4_mb_get_buddy_cache_lock(struct super_block *, ext4_group_t);
1438 extern void ext4_mb_put_buddy_cache_lock(struct super_block *,
1439 						ext4_group_t, int);
1440 /* inode.c */
1441 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1442 						ext4_lblk_t, int, int *);
1443 struct buffer_head *ext4_bread(handle_t *, struct inode *,
1444 						ext4_lblk_t, int, int *);
1445 int ext4_get_block(struct inode *inode, sector_t iblock,
1446 				struct buffer_head *bh_result, int create);
1447 
1448 extern struct inode *ext4_iget(struct super_block *, unsigned long);
1449 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
1450 extern int  ext4_setattr(struct dentry *, struct iattr *);
1451 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1452 				struct kstat *stat);
1453 extern void ext4_delete_inode(struct inode *);
1454 extern int  ext4_sync_inode(handle_t *, struct inode *);
1455 extern void ext4_dirty_inode(struct inode *);
1456 extern int ext4_change_inode_journal_flag(struct inode *, int);
1457 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1458 extern int ext4_can_truncate(struct inode *inode);
1459 extern void ext4_truncate(struct inode *);
1460 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
1461 extern void ext4_set_inode_flags(struct inode *);
1462 extern void ext4_get_inode_flags(struct ext4_inode_info *);
1463 extern int ext4_alloc_da_blocks(struct inode *inode);
1464 extern void ext4_set_aops(struct inode *inode);
1465 extern int ext4_writepage_trans_blocks(struct inode *);
1466 extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);
1467 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1468 extern int ext4_block_truncate_page(handle_t *handle,
1469 		struct address_space *mapping, loff_t from);
1470 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1471 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
1472 extern int flush_completed_IO(struct inode *inode);
1473 extern void ext4_da_update_reserve_space(struct inode *inode,
1474 					int used, int quota_claim);
1475 /* ioctl.c */
1476 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1477 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1478 
1479 /* migrate.c */
1480 extern int ext4_ext_migrate(struct inode *);
1481 
1482 /* namei.c */
1483 extern unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize);
1484 extern __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize);
1485 extern int ext4_orphan_add(handle_t *, struct inode *);
1486 extern int ext4_orphan_del(handle_t *, struct inode *);
1487 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1488 				__u32 start_minor_hash, __u32 *next_hash);
1489 
1490 /* resize.c */
1491 extern int ext4_group_add(struct super_block *sb,
1492 				struct ext4_new_group_data *input);
1493 extern int ext4_group_extend(struct super_block *sb,
1494 				struct ext4_super_block *es,
1495 				ext4_fsblk_t n_blocks_count);
1496 
1497 /* super.c */
1498 extern void __ext4_error(struct super_block *, const char *, const char *, ...)
1499 	__attribute__ ((format (printf, 3, 4)));
1500 #define ext4_error(sb, message...)	__ext4_error(sb, __func__, ## message)
1501 extern void ext4_error_inode(const char *, struct inode *, const char *, ...)
1502 	__attribute__ ((format (printf, 3, 4)));
1503 extern void ext4_error_file(const char *, struct file *, const char *, ...)
1504 	__attribute__ ((format (printf, 3, 4)));
1505 extern void __ext4_std_error(struct super_block *, const char *, int);
1506 extern void ext4_abort(struct super_block *, const char *, const char *, ...)
1507 	__attribute__ ((format (printf, 3, 4)));
1508 extern void __ext4_warning(struct super_block *, const char *,
1509 			  const char *, ...)
1510 	__attribute__ ((format (printf, 3, 4)));
1511 #define ext4_warning(sb, message...)	__ext4_warning(sb, __func__, ## message)
1512 extern void ext4_msg(struct super_block *, const char *, const char *, ...)
1513 	__attribute__ ((format (printf, 3, 4)));
1514 extern void ext4_grp_locked_error(struct super_block *, ext4_group_t,
1515 				const char *, const char *, ...)
1516 	__attribute__ ((format (printf, 4, 5)));
1517 extern void ext4_update_dynamic_rev(struct super_block *sb);
1518 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1519 					__u32 compat);
1520 extern int ext4_update_rocompat_feature(handle_t *handle,
1521 					struct super_block *sb,	__u32 rocompat);
1522 extern int ext4_update_incompat_feature(handle_t *handle,
1523 					struct super_block *sb,	__u32 incompat);
1524 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1525 				      struct ext4_group_desc *bg);
1526 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1527 				      struct ext4_group_desc *bg);
1528 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1529 				     struct ext4_group_desc *bg);
1530 extern __u32 ext4_free_blks_count(struct super_block *sb,
1531 				struct ext4_group_desc *bg);
1532 extern __u32 ext4_free_inodes_count(struct super_block *sb,
1533 				 struct ext4_group_desc *bg);
1534 extern __u32 ext4_used_dirs_count(struct super_block *sb,
1535 				struct ext4_group_desc *bg);
1536 extern __u32 ext4_itable_unused_count(struct super_block *sb,
1537 				   struct ext4_group_desc *bg);
1538 extern void ext4_block_bitmap_set(struct super_block *sb,
1539 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1540 extern void ext4_inode_bitmap_set(struct super_block *sb,
1541 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1542 extern void ext4_inode_table_set(struct super_block *sb,
1543 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
1544 extern void ext4_free_blks_set(struct super_block *sb,
1545 			       struct ext4_group_desc *bg, __u32 count);
1546 extern void ext4_free_inodes_set(struct super_block *sb,
1547 				struct ext4_group_desc *bg, __u32 count);
1548 extern void ext4_used_dirs_set(struct super_block *sb,
1549 				struct ext4_group_desc *bg, __u32 count);
1550 extern void ext4_itable_unused_set(struct super_block *sb,
1551 				   struct ext4_group_desc *bg, __u32 count);
1552 extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
1553 				   struct ext4_group_desc *gdp);
1554 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
1555 				       struct ext4_group_desc *gdp);
1556 
1557 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
1558 {
1559 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
1560 		le32_to_cpu(es->s_blocks_count_lo);
1561 }
1562 
1563 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
1564 {
1565 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
1566 		le32_to_cpu(es->s_r_blocks_count_lo);
1567 }
1568 
1569 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
1570 {
1571 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
1572 		le32_to_cpu(es->s_free_blocks_count_lo);
1573 }
1574 
1575 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
1576 					 ext4_fsblk_t blk)
1577 {
1578 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
1579 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
1580 }
1581 
1582 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
1583 					      ext4_fsblk_t blk)
1584 {
1585 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
1586 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
1587 }
1588 
1589 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
1590 					   ext4_fsblk_t blk)
1591 {
1592 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
1593 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
1594 }
1595 
1596 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
1597 {
1598 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
1599 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
1600 			le32_to_cpu(raw_inode->i_size_lo);
1601 	else
1602 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
1603 }
1604 
1605 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
1606 {
1607 	raw_inode->i_size_lo = cpu_to_le32(i_size);
1608 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
1609 }
1610 
1611 static inline
1612 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
1613 					    ext4_group_t group)
1614 {
1615 	 struct ext4_group_info ***grp_info;
1616 	 long indexv, indexh;
1617 	 grp_info = EXT4_SB(sb)->s_group_info;
1618 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
1619 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
1620 	 return grp_info[indexv][indexh];
1621 }
1622 
1623 /*
1624  * Reading s_groups_count requires using smp_rmb() afterwards.  See
1625  * the locking protocol documented in the comments of ext4_group_add()
1626  * in resize.c
1627  */
1628 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
1629 {
1630 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
1631 
1632 	smp_rmb();
1633 	return ngroups;
1634 }
1635 
1636 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
1637 					     ext4_group_t block_group)
1638 {
1639 	return block_group >> sbi->s_log_groups_per_flex;
1640 }
1641 
1642 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
1643 {
1644 	return 1 << sbi->s_log_groups_per_flex;
1645 }
1646 
1647 #define ext4_std_error(sb, errno)				\
1648 do {								\
1649 	if ((errno))						\
1650 		__ext4_std_error((sb), __func__, (errno));	\
1651 } while (0)
1652 
1653 #ifdef CONFIG_SMP
1654 /* Each CPU can accumulate percpu_counter_batch blocks in their local
1655  * counters. So we need to make sure we have free blocks more
1656  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
1657  */
1658 #define EXT4_FREEBLOCKS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
1659 #else
1660 #define EXT4_FREEBLOCKS_WATERMARK 0
1661 #endif
1662 
1663 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
1664 {
1665 	/*
1666 	 * XXX: replace with spinlock if seen contended -bzzz
1667 	 */
1668 	down_write(&EXT4_I(inode)->i_data_sem);
1669 	if (newsize > EXT4_I(inode)->i_disksize)
1670 		EXT4_I(inode)->i_disksize = newsize;
1671 	up_write(&EXT4_I(inode)->i_data_sem);
1672 	return ;
1673 }
1674 
1675 struct ext4_group_info {
1676 	unsigned long   bb_state;
1677 	struct rb_root  bb_free_root;
1678 	ext4_grpblk_t	bb_first_free;	/* first free block */
1679 	ext4_grpblk_t	bb_free;	/* total free blocks */
1680 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
1681 	struct          list_head bb_prealloc_list;
1682 #ifdef DOUBLE_CHECK
1683 	void            *bb_bitmap;
1684 #endif
1685 	struct rw_semaphore alloc_sem;
1686 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
1687 					 * regions, index is order.
1688 					 * bb_counters[3] = 5 means
1689 					 * 5 free 8-block regions. */
1690 };
1691 
1692 #define EXT4_GROUP_INFO_NEED_INIT_BIT	0
1693 
1694 #define EXT4_MB_GRP_NEED_INIT(grp)	\
1695 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
1696 
1697 #define EXT4_MAX_CONTENTION		8
1698 #define EXT4_CONTENTION_THRESHOLD	2
1699 
1700 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
1701 					      ext4_group_t group)
1702 {
1703 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
1704 }
1705 
1706 /*
1707  * Returns true if the filesystem is busy enough that attempts to
1708  * access the block group locks has run into contention.
1709  */
1710 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
1711 {
1712 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
1713 }
1714 
1715 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
1716 {
1717 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
1718 	if (spin_trylock(lock))
1719 		/*
1720 		 * We're able to grab the lock right away, so drop the
1721 		 * lock contention counter.
1722 		 */
1723 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
1724 	else {
1725 		/*
1726 		 * The lock is busy, so bump the contention counter,
1727 		 * and then wait on the spin lock.
1728 		 */
1729 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
1730 				  EXT4_MAX_CONTENTION);
1731 		spin_lock(lock);
1732 	}
1733 }
1734 
1735 static inline void ext4_unlock_group(struct super_block *sb,
1736 					ext4_group_t group)
1737 {
1738 	spin_unlock(ext4_group_lock_ptr(sb, group));
1739 }
1740 
1741 /*
1742  * Inodes and files operations
1743  */
1744 
1745 /* dir.c */
1746 extern const struct file_operations ext4_dir_operations;
1747 
1748 /* file.c */
1749 extern const struct inode_operations ext4_file_inode_operations;
1750 extern const struct file_operations ext4_file_operations;
1751 
1752 /* namei.c */
1753 extern const struct inode_operations ext4_dir_inode_operations;
1754 extern const struct inode_operations ext4_special_inode_operations;
1755 extern struct dentry *ext4_get_parent(struct dentry *child);
1756 
1757 /* symlink.c */
1758 extern const struct inode_operations ext4_symlink_inode_operations;
1759 extern const struct inode_operations ext4_fast_symlink_inode_operations;
1760 
1761 /* block_validity */
1762 extern void ext4_release_system_zone(struct super_block *sb);
1763 extern int ext4_setup_system_zone(struct super_block *sb);
1764 extern int __init init_ext4_system_zone(void);
1765 extern void exit_ext4_system_zone(void);
1766 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
1767 				 ext4_fsblk_t start_blk,
1768 				 unsigned int count);
1769 
1770 /* extents.c */
1771 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
1772 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
1773 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
1774 				       int chunk);
1775 extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
1776 			       ext4_lblk_t iblock, unsigned int max_blocks,
1777 			       struct buffer_head *bh_result, int flags);
1778 extern void ext4_ext_truncate(struct inode *);
1779 extern void ext4_ext_init(struct super_block *);
1780 extern void ext4_ext_release(struct super_block *);
1781 extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
1782 			  loff_t len);
1783 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
1784 			  ssize_t len);
1785 extern int ext4_get_blocks(handle_t *handle, struct inode *inode,
1786 			   sector_t block, unsigned int max_blocks,
1787 			   struct buffer_head *bh, int flags);
1788 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1789 			__u64 start, __u64 len);
1790 /* move_extent.c */
1791 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
1792 			     __u64 start_orig, __u64 start_donor,
1793 			     __u64 len, __u64 *moved_len);
1794 
1795 
1796 /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
1797 enum ext4_state_bits {
1798 	BH_Uninit	/* blocks are allocated but uninitialized on disk */
1799 	  = BH_JBDPrivateStart,
1800 };
1801 
1802 BUFFER_FNS(Uninit, uninit)
1803 TAS_BUFFER_FNS(Uninit, uninit)
1804 
1805 /*
1806  * Add new method to test wether block and inode bitmaps are properly
1807  * initialized. With uninit_bg reading the block from disk is not enough
1808  * to mark the bitmap uptodate. We need to also zero-out the bitmap
1809  */
1810 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
1811 
1812 static inline int bitmap_uptodate(struct buffer_head *bh)
1813 {
1814 	return (buffer_uptodate(bh) &&
1815 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
1816 }
1817 static inline void set_bitmap_uptodate(struct buffer_head *bh)
1818 {
1819 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
1820 }
1821 
1822 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
1823 
1824 #endif	/* __KERNEL__ */
1825 
1826 #endif	/* _EXT4_H */
1827