xref: /openbmc/linux/fs/ext4/ext4.h (revision 7dd65feb)
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 	ext4_lblk_t		offset;		/* offset in the file */
143 	size_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_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
288 
289 #define EXT4_FL_USER_VISIBLE		0x000BDFFF /* User visible flags */
290 #define EXT4_FL_USER_MODIFIABLE		0x000B80FF /* User modifiable flags */
291 
292 /* Flags that should be inherited by new inodes from their parent. */
293 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
294 			   EXT4_SYNC_FL | EXT4_IMMUTABLE_FL | EXT4_APPEND_FL |\
295 			   EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
296 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
297 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
298 
299 /* Flags that are appropriate for regular files (all but dir-specific ones). */
300 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
301 
302 /* Flags that are appropriate for non-directories/regular files. */
303 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
304 
305 /* Mask out flags that are inappropriate for the given type of inode. */
306 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
307 {
308 	if (S_ISDIR(mode))
309 		return flags;
310 	else if (S_ISREG(mode))
311 		return flags & EXT4_REG_FLMASK;
312 	else
313 		return flags & EXT4_OTHER_FLMASK;
314 }
315 
316 /*
317  * Inode dynamic state flags
318  */
319 #define EXT4_STATE_JDATA		0x00000001 /* journaled data exists */
320 #define EXT4_STATE_NEW			0x00000002 /* inode is newly created */
321 #define EXT4_STATE_XATTR		0x00000004 /* has in-inode xattrs */
322 #define EXT4_STATE_NO_EXPAND		0x00000008 /* No space for expansion */
323 #define EXT4_STATE_DA_ALLOC_CLOSE	0x00000010 /* Alloc DA blks on close */
324 #define EXT4_STATE_EXT_MIGRATE		0x00000020 /* Inode is migrating */
325 #define EXT4_STATE_DIO_UNWRITTEN	0x00000040 /* need convert on dio done*/
326 
327 /* Used to pass group descriptor data when online resize is done */
328 struct ext4_new_group_input {
329 	__u32 group;		/* Group number for this data */
330 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
331 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
332 	__u64 inode_table;	/* Absolute block number of inode table start */
333 	__u32 blocks_count;	/* Total number of blocks in this group */
334 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
335 	__u16 unused;
336 };
337 
338 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
339 struct ext4_new_group_data {
340 	__u32 group;
341 	__u64 block_bitmap;
342 	__u64 inode_bitmap;
343 	__u64 inode_table;
344 	__u32 blocks_count;
345 	__u16 reserved_blocks;
346 	__u16 unused;
347 	__u32 free_blocks_count;
348 };
349 
350 /*
351  * Flags used by ext4_get_blocks()
352  */
353 	/* Allocate any needed blocks and/or convert an unitialized
354 	   extent to be an initialized ext4 */
355 #define EXT4_GET_BLOCKS_CREATE			0x0001
356 	/* Request the creation of an unitialized extent */
357 #define EXT4_GET_BLOCKS_UNINIT_EXT		0x0002
358 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\
359 						 EXT4_GET_BLOCKS_CREATE)
360 	/* Caller is from the delayed allocation writeout path,
361 	   so set the magic i_delalloc_reserve_flag after taking the
362 	   inode allocation semaphore for */
363 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
364 	/* Call ext4_da_update_reserve_space() after successfully
365 	   allocating the blocks */
366 #define EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE	0x0008
367 	/* caller is from the direct IO path, request to creation of an
368 	unitialized extents if not allocated, split the uninitialized
369 	extent if blocks has been preallocated already*/
370 #define EXT4_GET_BLOCKS_DIO			0x0010
371 #define EXT4_GET_BLOCKS_CONVERT			0x0020
372 #define EXT4_GET_BLOCKS_DIO_CREATE_EXT		(EXT4_GET_BLOCKS_DIO|\
373 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
374 	/* Convert extent to initialized after direct IO complete */
375 #define EXT4_GET_BLOCKS_DIO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
376 					 EXT4_GET_BLOCKS_DIO_CREATE_EXT)
377 
378 /*
379  * Flags used by ext4_free_blocks
380  */
381 #define EXT4_FREE_BLOCKS_METADATA	0x0001
382 #define EXT4_FREE_BLOCKS_FORGET		0x0002
383 
384 /*
385  * ioctl commands
386  */
387 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
388 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
389 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
390 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
391 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
392 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
393 #ifdef CONFIG_JBD2_DEBUG
394 #define EXT4_IOC_WAIT_FOR_READONLY	_IOR('f', 99, long)
395 #endif
396 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
397 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
398 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
399 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
400 #define EXT4_IOC_MIGRATE		_IO('f', 9)
401  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
402  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
403 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
404 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
405 
406 /*
407  * ioctl commands in 32 bit emulation
408  */
409 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
410 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
411 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
412 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
413 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
414 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
415 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
416 #ifdef CONFIG_JBD2_DEBUG
417 #define EXT4_IOC32_WAIT_FOR_READONLY	_IOR('f', 99, int)
418 #endif
419 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
420 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
421 
422 
423 /*
424  *  Mount options
425  */
426 struct ext4_mount_options {
427 	unsigned long s_mount_opt;
428 	uid_t s_resuid;
429 	gid_t s_resgid;
430 	unsigned long s_commit_interval;
431 	u32 s_min_batch_time, s_max_batch_time;
432 #ifdef CONFIG_QUOTA
433 	int s_jquota_fmt;
434 	char *s_qf_names[MAXQUOTAS];
435 #endif
436 };
437 
438 /* Max physical block we can addres w/o extents */
439 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
440 
441 /*
442  * Structure of an inode on the disk
443  */
444 struct ext4_inode {
445 	__le16	i_mode;		/* File mode */
446 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
447 	__le32	i_size_lo;	/* Size in bytes */
448 	__le32	i_atime;	/* Access time */
449 	__le32	i_ctime;	/* Inode Change time */
450 	__le32	i_mtime;	/* Modification time */
451 	__le32	i_dtime;	/* Deletion Time */
452 	__le16	i_gid;		/* Low 16 bits of Group Id */
453 	__le16	i_links_count;	/* Links count */
454 	__le32	i_blocks_lo;	/* Blocks count */
455 	__le32	i_flags;	/* File flags */
456 	union {
457 		struct {
458 			__le32  l_i_version;
459 		} linux1;
460 		struct {
461 			__u32  h_i_translator;
462 		} hurd1;
463 		struct {
464 			__u32  m_i_reserved1;
465 		} masix1;
466 	} osd1;				/* OS dependent 1 */
467 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
468 	__le32	i_generation;	/* File version (for NFS) */
469 	__le32	i_file_acl_lo;	/* File ACL */
470 	__le32	i_size_high;
471 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
472 	union {
473 		struct {
474 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
475 			__le16	l_i_file_acl_high;
476 			__le16	l_i_uid_high;	/* these 2 fields */
477 			__le16	l_i_gid_high;	/* were reserved2[0] */
478 			__u32	l_i_reserved2;
479 		} linux2;
480 		struct {
481 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
482 			__u16	h_i_mode_high;
483 			__u16	h_i_uid_high;
484 			__u16	h_i_gid_high;
485 			__u32	h_i_author;
486 		} hurd2;
487 		struct {
488 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
489 			__le16	m_i_file_acl_high;
490 			__u32	m_i_reserved2[2];
491 		} masix2;
492 	} osd2;				/* OS dependent 2 */
493 	__le16	i_extra_isize;
494 	__le16	i_pad1;
495 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
496 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
497 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
498 	__le32  i_crtime;       /* File Creation time */
499 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
500 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
501 };
502 
503 struct move_extent {
504 	__u32 reserved;		/* should be zero */
505 	__u32 donor_fd;		/* donor file descriptor */
506 	__u64 orig_start;	/* logical start offset in block for orig */
507 	__u64 donor_start;	/* logical start offset in block for donor */
508 	__u64 len;		/* block length to be moved */
509 	__u64 moved_len;	/* moved block length */
510 };
511 
512 #define EXT4_EPOCH_BITS 2
513 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
514 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
515 
516 /*
517  * Extended fields will fit into an inode if the filesystem was formatted
518  * with large inodes (-I 256 or larger) and there are not currently any EAs
519  * consuming all of the available space. For new inodes we always reserve
520  * enough space for the kernel's known extended fields, but for inodes
521  * created with an old kernel this might not have been the case. None of
522  * the extended inode fields is critical for correct filesystem operation.
523  * This macro checks if a certain field fits in the inode. Note that
524  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
525  */
526 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
527 	((offsetof(typeof(*ext4_inode), field) +	\
528 	  sizeof((ext4_inode)->field))			\
529 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
530 	    (einode)->i_extra_isize))			\
531 
532 static inline __le32 ext4_encode_extra_time(struct timespec *time)
533 {
534        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
535 			   (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
536                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
537 }
538 
539 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
540 {
541        if (sizeof(time->tv_sec) > 4)
542 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
543 			       << 32;
544        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
545 }
546 
547 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
548 do {									       \
549 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
550 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
551 		(raw_inode)->xtime ## _extra =				       \
552 				ext4_encode_extra_time(&(inode)->xtime);       \
553 } while (0)
554 
555 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
556 do {									       \
557 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
558 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
559 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
560 		(raw_inode)->xtime ## _extra =				       \
561 				ext4_encode_extra_time(&(einode)->xtime);      \
562 } while (0)
563 
564 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
565 do {									       \
566 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
567 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
568 		ext4_decode_extra_time(&(inode)->xtime,			       \
569 				       raw_inode->xtime ## _extra);	       \
570 } while (0)
571 
572 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
573 do {									       \
574 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
575 		(einode)->xtime.tv_sec = 				       \
576 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
577 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
578 		ext4_decode_extra_time(&(einode)->xtime,		       \
579 				       raw_inode->xtime ## _extra);	       \
580 } while (0)
581 
582 #define i_disk_version osd1.linux1.l_i_version
583 
584 #if defined(__KERNEL__) || defined(__linux__)
585 #define i_reserved1	osd1.linux1.l_i_reserved1
586 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
587 #define i_blocks_high	osd2.linux2.l_i_blocks_high
588 #define i_uid_low	i_uid
589 #define i_gid_low	i_gid
590 #define i_uid_high	osd2.linux2.l_i_uid_high
591 #define i_gid_high	osd2.linux2.l_i_gid_high
592 #define i_reserved2	osd2.linux2.l_i_reserved2
593 
594 #elif defined(__GNU__)
595 
596 #define i_translator	osd1.hurd1.h_i_translator
597 #define i_uid_high	osd2.hurd2.h_i_uid_high
598 #define i_gid_high	osd2.hurd2.h_i_gid_high
599 #define i_author	osd2.hurd2.h_i_author
600 
601 #elif defined(__masix__)
602 
603 #define i_reserved1	osd1.masix1.m_i_reserved1
604 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
605 #define i_reserved2	osd2.masix2.m_i_reserved2
606 
607 #endif /* defined(__KERNEL__) || defined(__linux__) */
608 
609 /*
610  * storage for cached extent
611  */
612 struct ext4_ext_cache {
613 	ext4_fsblk_t	ec_start;
614 	ext4_lblk_t	ec_block;
615 	__u32		ec_len; /* must be 32bit to return holes */
616 	__u32		ec_type;
617 };
618 
619 /*
620  * fourth extended file system inode data in memory
621  */
622 struct ext4_inode_info {
623 	__le32	i_data[15];	/* unconverted */
624 	__u32	i_flags;
625 	ext4_fsblk_t	i_file_acl;
626 	__u32	i_dtime;
627 
628 	/*
629 	 * i_block_group is the number of the block group which contains
630 	 * this file's inode.  Constant across the lifetime of the inode,
631 	 * it is ued for making block allocation decisions - we try to
632 	 * place a file's data blocks near its inode block, and new inodes
633 	 * near to their parent directory's inode.
634 	 */
635 	ext4_group_t	i_block_group;
636 	__u32	i_state;		/* Dynamic state flags for ext4 */
637 
638 	ext4_lblk_t		i_dir_start_lookup;
639 #ifdef CONFIG_EXT4_FS_XATTR
640 	/*
641 	 * Extended attributes can be read independently of the main file
642 	 * data. Taking i_mutex even when reading would cause contention
643 	 * between readers of EAs and writers of regular file data, so
644 	 * instead we synchronize on xattr_sem when reading or changing
645 	 * EAs.
646 	 */
647 	struct rw_semaphore xattr_sem;
648 #endif
649 
650 	struct list_head i_orphan;	/* unlinked but open inodes */
651 
652 	/*
653 	 * i_disksize keeps track of what the inode size is ON DISK, not
654 	 * in memory.  During truncate, i_size is set to the new size by
655 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
656 	 * set i_disksize to 0 until the truncate is actually under way.
657 	 *
658 	 * The intent is that i_disksize always represents the blocks which
659 	 * are used by this file.  This allows recovery to restart truncate
660 	 * on orphans if we crash during truncate.  We actually write i_disksize
661 	 * into the on-disk inode when writing inodes out, instead of i_size.
662 	 *
663 	 * The only time when i_disksize and i_size may be different is when
664 	 * a truncate is in progress.  The only things which change i_disksize
665 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
666 	 */
667 	loff_t	i_disksize;
668 
669 	/*
670 	 * i_data_sem is for serialising ext4_truncate() against
671 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
672 	 * data tree are chopped off during truncate. We can't do that in
673 	 * ext4 because whenever we perform intermediate commits during
674 	 * truncate, the inode and all the metadata blocks *must* be in a
675 	 * consistent state which allows truncation of the orphans to restart
676 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
677 	 * by other means, so we have i_data_sem.
678 	 */
679 	struct rw_semaphore i_data_sem;
680 	struct inode vfs_inode;
681 	struct jbd2_inode jinode;
682 
683 	struct ext4_ext_cache i_cached_extent;
684 	/*
685 	 * File creation time. Its function is same as that of
686 	 * struct timespec i_{a,c,m}time in the generic inode.
687 	 */
688 	struct timespec i_crtime;
689 
690 	/* mballoc */
691 	struct list_head i_prealloc_list;
692 	spinlock_t i_prealloc_lock;
693 
694 	/* ialloc */
695 	ext4_group_t	i_last_alloc_group;
696 
697 	/* allocation reservation info for delalloc */
698 	unsigned int i_reserved_data_blocks;
699 	unsigned int i_reserved_meta_blocks;
700 	unsigned int i_allocated_meta_blocks;
701 	unsigned short i_delalloc_reserved_flag;
702 	sector_t i_da_metadata_calc_last_lblock;
703 	int i_da_metadata_calc_len;
704 
705 	/* on-disk additional length */
706 	__u16 i_extra_isize;
707 
708 	spinlock_t i_block_reservation_lock;
709 #ifdef CONFIG_QUOTA
710 	/* quota space reservation, managed internally by quota code */
711 	qsize_t i_reserved_quota;
712 #endif
713 
714 	/* completed async DIOs that might need unwritten extents handling */
715 	struct list_head i_aio_dio_complete_list;
716 	/* current io_end structure for async DIO write*/
717 	ext4_io_end_t *cur_aio_dio;
718 
719 	/*
720 	 * Transactions that contain inode's metadata needed to complete
721 	 * fsync and fdatasync, respectively.
722 	 */
723 	tid_t i_sync_tid;
724 	tid_t i_datasync_tid;
725 };
726 
727 /*
728  * File system states
729  */
730 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
731 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
732 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
733 
734 /*
735  * Misc. filesystem flags
736  */
737 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
738 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
739 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
740 
741 /*
742  * Mount flags
743  */
744 #define EXT4_MOUNT_OLDALLOC		0x00002  /* Don't use the new Orlov allocator */
745 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
746 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
747 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
748 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
749 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
750 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
751 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
752 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
753 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
754 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
755 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
756 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
757 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
758 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
759 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
760 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
761 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
762 #define EXT4_MOUNT_NOBH			0x40000 /* No bufferheads */
763 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
764 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
765 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
766 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
767 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
768 #define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
769 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
770 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
771 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
772 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
773 
774 #define clear_opt(o, opt)		o &= ~EXT4_MOUNT_##opt
775 #define set_opt(o, opt)			o |= EXT4_MOUNT_##opt
776 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
777 					 EXT4_MOUNT_##opt)
778 
779 #define ext4_set_bit			ext2_set_bit
780 #define ext4_set_bit_atomic		ext2_set_bit_atomic
781 #define ext4_clear_bit			ext2_clear_bit
782 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
783 #define ext4_test_bit			ext2_test_bit
784 #define ext4_find_first_zero_bit	ext2_find_first_zero_bit
785 #define ext4_find_next_zero_bit		ext2_find_next_zero_bit
786 #define ext4_find_next_bit		ext2_find_next_bit
787 
788 /*
789  * Maximal mount counts between two filesystem checks
790  */
791 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
792 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
793 
794 /*
795  * Behaviour when detecting errors
796  */
797 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
798 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
799 #define EXT4_ERRORS_PANIC		3	/* Panic */
800 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
801 
802 /*
803  * Structure of the super block
804  */
805 struct ext4_super_block {
806 /*00*/	__le32	s_inodes_count;		/* Inodes count */
807 	__le32	s_blocks_count_lo;	/* Blocks count */
808 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
809 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
810 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
811 	__le32	s_first_data_block;	/* First Data Block */
812 	__le32	s_log_block_size;	/* Block size */
813 	__le32	s_obso_log_frag_size;	/* Obsoleted fragment size */
814 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
815 	__le32	s_obso_frags_per_group;	/* Obsoleted fragments per group */
816 	__le32	s_inodes_per_group;	/* # Inodes per group */
817 	__le32	s_mtime;		/* Mount time */
818 /*30*/	__le32	s_wtime;		/* Write time */
819 	__le16	s_mnt_count;		/* Mount count */
820 	__le16	s_max_mnt_count;	/* Maximal mount count */
821 	__le16	s_magic;		/* Magic signature */
822 	__le16	s_state;		/* File system state */
823 	__le16	s_errors;		/* Behaviour when detecting errors */
824 	__le16	s_minor_rev_level;	/* minor revision level */
825 /*40*/	__le32	s_lastcheck;		/* time of last check */
826 	__le32	s_checkinterval;	/* max. time between checks */
827 	__le32	s_creator_os;		/* OS */
828 	__le32	s_rev_level;		/* Revision level */
829 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
830 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
831 	/*
832 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
833 	 *
834 	 * Note: the difference between the compatible feature set and
835 	 * the incompatible feature set is that if there is a bit set
836 	 * in the incompatible feature set that the kernel doesn't
837 	 * know about, it should refuse to mount the filesystem.
838 	 *
839 	 * e2fsck's requirements are more strict; if it doesn't know
840 	 * about a feature in either the compatible or incompatible
841 	 * feature set, it must abort and not try to meddle with
842 	 * things it doesn't understand...
843 	 */
844 	__le32	s_first_ino;		/* First non-reserved inode */
845 	__le16  s_inode_size;		/* size of inode structure */
846 	__le16	s_block_group_nr;	/* block group # of this superblock */
847 	__le32	s_feature_compat;	/* compatible feature set */
848 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
849 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
850 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
851 /*78*/	char	s_volume_name[16];	/* volume name */
852 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
853 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
854 	/*
855 	 * Performance hints.  Directory preallocation should only
856 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
857 	 */
858 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
859 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
860 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
861 	/*
862 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
863 	 */
864 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
865 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
866 	__le32	s_journal_dev;		/* device number of journal file */
867 	__le32	s_last_orphan;		/* start of list of inodes to delete */
868 	__le32	s_hash_seed[4];		/* HTREE hash seed */
869 	__u8	s_def_hash_version;	/* Default hash version to use */
870 	__u8	s_reserved_char_pad;
871 	__le16  s_desc_size;		/* size of group descriptor */
872 /*100*/	__le32	s_default_mount_opts;
873 	__le32	s_first_meta_bg;	/* First metablock block group */
874 	__le32	s_mkfs_time;		/* When the filesystem was created */
875 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
876 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
877 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
878 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
879 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
880 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
881 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
882 	__le32	s_flags;		/* Miscellaneous flags */
883 	__le16  s_raid_stride;		/* RAID stride */
884 	__le16  s_mmp_interval;         /* # seconds to wait in MMP checking */
885 	__le64  s_mmp_block;            /* Block for multi-mount protection */
886 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
887 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
888 	__u8	s_reserved_char_pad2;
889 	__le16  s_reserved_pad;
890 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
891 	__u32   s_reserved[160];        /* Padding to the end of the block */
892 };
893 
894 #ifdef __KERNEL__
895 
896 /*
897  * run-time mount flags
898  */
899 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
900 #define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
901 
902 /*
903  * fourth extended-fs super-block data in memory
904  */
905 struct ext4_sb_info {
906 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
907 	unsigned long s_inodes_per_block;/* Number of inodes per block */
908 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
909 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
910 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
911 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
912 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
913 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
914 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
915 	unsigned long s_overhead_last;  /* Last calculated overhead */
916 	unsigned long s_blocks_last;    /* Last seen block count */
917 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
918 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
919 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
920 	struct buffer_head **s_group_desc;
921 	unsigned int s_mount_opt;
922 	unsigned int s_mount_flags;
923 	ext4_fsblk_t s_sb_block;
924 	uid_t s_resuid;
925 	gid_t s_resgid;
926 	unsigned short s_mount_state;
927 	unsigned short s_pad;
928 	int s_addr_per_block_bits;
929 	int s_desc_per_block_bits;
930 	int s_inode_size;
931 	int s_first_ino;
932 	unsigned int s_inode_readahead_blks;
933 	unsigned int s_inode_goal;
934 	spinlock_t s_next_gen_lock;
935 	u32 s_next_generation;
936 	u32 s_hash_seed[4];
937 	int s_def_hash_version;
938 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
939 	struct percpu_counter s_freeblocks_counter;
940 	struct percpu_counter s_freeinodes_counter;
941 	struct percpu_counter s_dirs_counter;
942 	struct percpu_counter s_dirtyblocks_counter;
943 	struct blockgroup_lock *s_blockgroup_lock;
944 	struct proc_dir_entry *s_proc;
945 	struct kobject s_kobj;
946 	struct completion s_kobj_unregister;
947 
948 	/* Journaling */
949 	struct inode *s_journal_inode;
950 	struct journal_s *s_journal;
951 	struct list_head s_orphan;
952 	struct mutex s_orphan_lock;
953 	struct mutex s_resize_lock;
954 	unsigned long s_commit_interval;
955 	u32 s_max_batch_time;
956 	u32 s_min_batch_time;
957 	struct block_device *journal_bdev;
958 #ifdef CONFIG_JBD2_DEBUG
959 	struct timer_list turn_ro_timer;	/* For turning read-only (crash simulation) */
960 	wait_queue_head_t ro_wait_queue;	/* For people waiting for the fs to go read-only */
961 #endif
962 #ifdef CONFIG_QUOTA
963 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
964 	int s_jquota_fmt;			/* Format of quota to use */
965 #endif
966 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
967 	struct rb_root system_blks;
968 
969 #ifdef EXTENTS_STATS
970 	/* ext4 extents stats */
971 	unsigned long s_ext_min;
972 	unsigned long s_ext_max;
973 	unsigned long s_depth_max;
974 	spinlock_t s_ext_stats_lock;
975 	unsigned long s_ext_blocks;
976 	unsigned long s_ext_extents;
977 #endif
978 
979 	/* for buddy allocator */
980 	struct ext4_group_info ***s_group_info;
981 	struct inode *s_buddy_cache;
982 	long s_blocks_reserved;
983 	spinlock_t s_reserve_lock;
984 	spinlock_t s_md_lock;
985 	tid_t s_last_transaction;
986 	unsigned short *s_mb_offsets;
987 	unsigned int *s_mb_maxs;
988 
989 	/* tunables */
990 	unsigned long s_stripe;
991 	unsigned int s_mb_stream_request;
992 	unsigned int s_mb_max_to_scan;
993 	unsigned int s_mb_min_to_scan;
994 	unsigned int s_mb_stats;
995 	unsigned int s_mb_order2_reqs;
996 	unsigned int s_mb_group_prealloc;
997 	unsigned int s_max_writeback_mb_bump;
998 	/* where last allocation was done - for stream allocation */
999 	unsigned long s_mb_last_group;
1000 	unsigned long s_mb_last_start;
1001 
1002 	/* stats for buddy allocator */
1003 	spinlock_t s_mb_pa_lock;
1004 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1005 	atomic_t s_bal_success;	/* we found long enough chunks */
1006 	atomic_t s_bal_allocated;	/* in blocks */
1007 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1008 	atomic_t s_bal_goals;	/* goal hits */
1009 	atomic_t s_bal_breaks;	/* too long searches */
1010 	atomic_t s_bal_2orders;	/* 2^order hits */
1011 	spinlock_t s_bal_lock;
1012 	unsigned long s_mb_buddies_generated;
1013 	unsigned long long s_mb_generation_time;
1014 	atomic_t s_mb_lost_chunks;
1015 	atomic_t s_mb_preallocated;
1016 	atomic_t s_mb_discarded;
1017 	atomic_t s_lock_busy;
1018 
1019 	/* locality groups */
1020 	struct ext4_locality_group *s_locality_groups;
1021 
1022 	/* for write statistics */
1023 	unsigned long s_sectors_written_start;
1024 	u64 s_kbytes_written;
1025 
1026 	unsigned int s_log_groups_per_flex;
1027 	struct flex_groups *s_flex_groups;
1028 
1029 	/* workqueue for dio unwritten */
1030 	struct workqueue_struct *dio_unwritten_wq;
1031 };
1032 
1033 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1034 {
1035 	return sb->s_fs_info;
1036 }
1037 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1038 {
1039 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1040 }
1041 
1042 static inline struct timespec ext4_current_time(struct inode *inode)
1043 {
1044 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1045 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1046 }
1047 
1048 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1049 {
1050 	return ino == EXT4_ROOT_INO ||
1051 		ino == EXT4_JOURNAL_INO ||
1052 		ino == EXT4_RESIZE_INO ||
1053 		(ino >= EXT4_FIRST_INO(sb) &&
1054 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1055 }
1056 #else
1057 /* Assume that user mode programs are passing in an ext4fs superblock, not
1058  * a kernel struct super_block.  This will allow us to call the feature-test
1059  * macros from user land. */
1060 #define EXT4_SB(sb)	(sb)
1061 #endif
1062 
1063 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1064 
1065 /*
1066  * Codes for operating systems
1067  */
1068 #define EXT4_OS_LINUX		0
1069 #define EXT4_OS_HURD		1
1070 #define EXT4_OS_MASIX		2
1071 #define EXT4_OS_FREEBSD		3
1072 #define EXT4_OS_LITES		4
1073 
1074 /*
1075  * Revision levels
1076  */
1077 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1078 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1079 
1080 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1081 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1082 
1083 #define EXT4_GOOD_OLD_INODE_SIZE 128
1084 
1085 /*
1086  * Feature set definitions
1087  */
1088 
1089 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1090 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1091 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1092 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1093 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1094 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1095 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1096 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1097 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1098 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1099 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1100 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1101 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1102 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1103 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1104 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1105 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1106 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1107 
1108 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1109 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1110 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1111 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1112 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1113 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1114 
1115 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1116 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1117 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1118 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1119 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1120 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1121 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1122 
1123 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1124 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1125 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1126 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1127 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1128 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1129 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1130 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1131 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1132 
1133 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1134 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1135 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1136 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1137 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1138 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1139 					 EXT4_FEATURE_INCOMPAT_FLEX_BG)
1140 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1141 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1142 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1143 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1144 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1145 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1146 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
1147 
1148 /*
1149  * Default values for user and/or group using reserved blocks
1150  */
1151 #define	EXT4_DEF_RESUID		0
1152 #define	EXT4_DEF_RESGID		0
1153 
1154 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1155 
1156 /*
1157  * Default mount options
1158  */
1159 #define EXT4_DEFM_DEBUG		0x0001
1160 #define EXT4_DEFM_BSDGROUPS	0x0002
1161 #define EXT4_DEFM_XATTR_USER	0x0004
1162 #define EXT4_DEFM_ACL		0x0008
1163 #define EXT4_DEFM_UID16		0x0010
1164 #define EXT4_DEFM_JMODE		0x0060
1165 #define EXT4_DEFM_JMODE_DATA	0x0020
1166 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1167 #define EXT4_DEFM_JMODE_WBACK	0x0060
1168 
1169 /*
1170  * Default journal batch times
1171  */
1172 #define EXT4_DEF_MIN_BATCH_TIME	0
1173 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1174 
1175 /*
1176  * Minimum number of groups in a flexgroup before we separate out
1177  * directories into the first block group of a flexgroup
1178  */
1179 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1180 
1181 /*
1182  * Structure of a directory entry
1183  */
1184 #define EXT4_NAME_LEN 255
1185 
1186 struct ext4_dir_entry {
1187 	__le32	inode;			/* Inode number */
1188 	__le16	rec_len;		/* Directory entry length */
1189 	__le16	name_len;		/* Name length */
1190 	char	name[EXT4_NAME_LEN];	/* File name */
1191 };
1192 
1193 /*
1194  * The new version of the directory entry.  Since EXT4 structures are
1195  * stored in intel byte order, and the name_len field could never be
1196  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1197  * file_type field.
1198  */
1199 struct ext4_dir_entry_2 {
1200 	__le32	inode;			/* Inode number */
1201 	__le16	rec_len;		/* Directory entry length */
1202 	__u8	name_len;		/* Name length */
1203 	__u8	file_type;
1204 	char	name[EXT4_NAME_LEN];	/* File name */
1205 };
1206 
1207 /*
1208  * Ext4 directory file types.  Only the low 3 bits are used.  The
1209  * other bits are reserved for now.
1210  */
1211 #define EXT4_FT_UNKNOWN		0
1212 #define EXT4_FT_REG_FILE	1
1213 #define EXT4_FT_DIR		2
1214 #define EXT4_FT_CHRDEV		3
1215 #define EXT4_FT_BLKDEV		4
1216 #define EXT4_FT_FIFO		5
1217 #define EXT4_FT_SOCK		6
1218 #define EXT4_FT_SYMLINK		7
1219 
1220 #define EXT4_FT_MAX		8
1221 
1222 /*
1223  * EXT4_DIR_PAD defines the directory entries boundaries
1224  *
1225  * NOTE: It must be a multiple of 4
1226  */
1227 #define EXT4_DIR_PAD			4
1228 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1229 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1230 					 ~EXT4_DIR_ROUND)
1231 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1232 
1233 /*
1234  * Hash Tree Directory indexing
1235  * (c) Daniel Phillips, 2001
1236  */
1237 
1238 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1239 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1240 		      (EXT4_I(dir)->i_flags & EXT4_INDEX_FL))
1241 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1242 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1243 
1244 /* Legal values for the dx_root hash_version field: */
1245 
1246 #define DX_HASH_LEGACY		0
1247 #define DX_HASH_HALF_MD4	1
1248 #define DX_HASH_TEA		2
1249 #define DX_HASH_LEGACY_UNSIGNED	3
1250 #define DX_HASH_HALF_MD4_UNSIGNED	4
1251 #define DX_HASH_TEA_UNSIGNED		5
1252 
1253 #ifdef __KERNEL__
1254 
1255 /* hash info structure used by the directory hash */
1256 struct dx_hash_info
1257 {
1258 	u32		hash;
1259 	u32		minor_hash;
1260 	int		hash_version;
1261 	u32		*seed;
1262 };
1263 
1264 #define EXT4_HTREE_EOF	0x7fffffff
1265 
1266 /*
1267  * Control parameters used by ext4_htree_next_block
1268  */
1269 #define HASH_NB_ALWAYS		1
1270 
1271 
1272 /*
1273  * Describe an inode's exact location on disk and in memory
1274  */
1275 struct ext4_iloc
1276 {
1277 	struct buffer_head *bh;
1278 	unsigned long offset;
1279 	ext4_group_t block_group;
1280 };
1281 
1282 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1283 {
1284 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1285 }
1286 
1287 /*
1288  * This structure is stuffed into the struct file's private_data field
1289  * for directories.  It is where we put information so that we can do
1290  * readdir operations in hash tree order.
1291  */
1292 struct dir_private_info {
1293 	struct rb_root	root;
1294 	struct rb_node	*curr_node;
1295 	struct fname	*extra_fname;
1296 	loff_t		last_pos;
1297 	__u32		curr_hash;
1298 	__u32		curr_minor_hash;
1299 	__u32		next_hash;
1300 };
1301 
1302 /* calculate the first block number of the group */
1303 static inline ext4_fsblk_t
1304 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1305 {
1306 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1307 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1308 }
1309 
1310 /*
1311  * Special error return code only used by dx_probe() and its callers.
1312  */
1313 #define ERR_BAD_DX_DIR	-75000
1314 
1315 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1316 			ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1317 
1318 extern struct proc_dir_entry *ext4_proc_root;
1319 
1320 /*
1321  * Function prototypes
1322  */
1323 
1324 /*
1325  * Ok, these declarations are also in <linux/kernel.h> but none of the
1326  * ext4 source programs needs to include it so they are duplicated here.
1327  */
1328 # define NORET_TYPE	/**/
1329 # define ATTRIB_NORET	__attribute__((noreturn))
1330 # define NORET_AND	noreturn,
1331 
1332 /* bitmap.c */
1333 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
1334 
1335 /* balloc.c */
1336 extern unsigned int ext4_block_group(struct super_block *sb,
1337 			ext4_fsblk_t blocknr);
1338 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1339 			ext4_fsblk_t blocknr);
1340 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1341 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1342 			ext4_group_t group);
1343 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1344 			ext4_fsblk_t goal, unsigned long *count, int *errp);
1345 extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1346 extern int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1347 extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
1348 				ext4_fsblk_t block, unsigned long count);
1349 extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
1350 extern void ext4_check_blocks_bitmap(struct super_block *);
1351 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1352 						    ext4_group_t block_group,
1353 						    struct buffer_head ** bh);
1354 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1355 struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1356 				      ext4_group_t block_group);
1357 extern unsigned ext4_init_block_bitmap(struct super_block *sb,
1358 				       struct buffer_head *bh,
1359 				       ext4_group_t group,
1360 				       struct ext4_group_desc *desc);
1361 #define ext4_free_blocks_after_init(sb, group, desc)			\
1362 		ext4_init_block_bitmap(sb, NULL, group, desc)
1363 
1364 /* dir.c */
1365 extern int ext4_check_dir_entry(const char *, struct inode *,
1366 				struct ext4_dir_entry_2 *,
1367 				struct buffer_head *, unsigned int);
1368 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1369 				    __u32 minor_hash,
1370 				    struct ext4_dir_entry_2 *dirent);
1371 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1372 
1373 /* fsync.c */
1374 extern int ext4_sync_file(struct file *, struct dentry *, int);
1375 
1376 /* hash.c */
1377 extern int ext4fs_dirhash(const char *name, int len, struct
1378 			  dx_hash_info *hinfo);
1379 
1380 /* ialloc.c */
1381 extern struct inode *ext4_new_inode(handle_t *, struct inode *, int,
1382 				    const struct qstr *qstr, __u32 goal);
1383 extern void ext4_free_inode(handle_t *, struct inode *);
1384 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1385 extern unsigned long ext4_count_free_inodes(struct super_block *);
1386 extern unsigned long ext4_count_dirs(struct super_block *);
1387 extern void ext4_check_inodes_bitmap(struct super_block *);
1388 extern unsigned ext4_init_inode_bitmap(struct super_block *sb,
1389 				       struct buffer_head *bh,
1390 				       ext4_group_t group,
1391 				       struct ext4_group_desc *desc);
1392 extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1393 
1394 /* mballoc.c */
1395 extern long ext4_mb_stats;
1396 extern long ext4_mb_max_to_scan;
1397 extern int ext4_mb_init(struct super_block *, int);
1398 extern int ext4_mb_release(struct super_block *);
1399 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1400 				struct ext4_allocation_request *, int *);
1401 extern int ext4_mb_reserve_blocks(struct super_block *, int);
1402 extern void ext4_discard_preallocations(struct inode *);
1403 extern int __init init_ext4_mballoc(void);
1404 extern void exit_ext4_mballoc(void);
1405 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1406 			     struct buffer_head *bh, ext4_fsblk_t block,
1407 			     unsigned long count, int flags);
1408 extern int ext4_mb_add_groupinfo(struct super_block *sb,
1409 		ext4_group_t i, struct ext4_group_desc *desc);
1410 extern int ext4_mb_get_buddy_cache_lock(struct super_block *, ext4_group_t);
1411 extern void ext4_mb_put_buddy_cache_lock(struct super_block *,
1412 						ext4_group_t, int);
1413 /* inode.c */
1414 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1415 						ext4_lblk_t, int, int *);
1416 struct buffer_head *ext4_bread(handle_t *, struct inode *,
1417 						ext4_lblk_t, int, int *);
1418 int ext4_get_block(struct inode *inode, sector_t iblock,
1419 				struct buffer_head *bh_result, int create);
1420 
1421 extern struct inode *ext4_iget(struct super_block *, unsigned long);
1422 extern int  ext4_write_inode(struct inode *, int);
1423 extern int  ext4_setattr(struct dentry *, struct iattr *);
1424 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1425 				struct kstat *stat);
1426 extern void ext4_delete_inode(struct inode *);
1427 extern int  ext4_sync_inode(handle_t *, struct inode *);
1428 extern void ext4_dirty_inode(struct inode *);
1429 extern int ext4_change_inode_journal_flag(struct inode *, int);
1430 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1431 extern int ext4_can_truncate(struct inode *inode);
1432 extern void ext4_truncate(struct inode *);
1433 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
1434 extern void ext4_set_inode_flags(struct inode *);
1435 extern void ext4_get_inode_flags(struct ext4_inode_info *);
1436 extern int ext4_alloc_da_blocks(struct inode *inode);
1437 extern void ext4_set_aops(struct inode *inode);
1438 extern int ext4_writepage_trans_blocks(struct inode *);
1439 extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);
1440 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1441 extern int ext4_block_truncate_page(handle_t *handle,
1442 		struct address_space *mapping, loff_t from);
1443 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1444 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
1445 extern int flush_aio_dio_completed_IO(struct inode *inode);
1446 /* ioctl.c */
1447 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1448 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1449 
1450 /* migrate.c */
1451 extern int ext4_ext_migrate(struct inode *);
1452 
1453 /* namei.c */
1454 extern unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize);
1455 extern __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize);
1456 extern int ext4_orphan_add(handle_t *, struct inode *);
1457 extern int ext4_orphan_del(handle_t *, struct inode *);
1458 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1459 				__u32 start_minor_hash, __u32 *next_hash);
1460 
1461 /* resize.c */
1462 extern int ext4_group_add(struct super_block *sb,
1463 				struct ext4_new_group_data *input);
1464 extern int ext4_group_extend(struct super_block *sb,
1465 				struct ext4_super_block *es,
1466 				ext4_fsblk_t n_blocks_count);
1467 
1468 /* super.c */
1469 extern void ext4_error(struct super_block *, const char *, const char *, ...)
1470 	__attribute__ ((format (printf, 3, 4)));
1471 extern void __ext4_std_error(struct super_block *, const char *, int);
1472 extern void ext4_abort(struct super_block *, const char *, const char *, ...)
1473 	__attribute__ ((format (printf, 3, 4)));
1474 extern void ext4_warning(struct super_block *, const char *, const char *, ...)
1475 	__attribute__ ((format (printf, 3, 4)));
1476 extern void ext4_msg(struct super_block *, const char *, const char *, ...)
1477 	__attribute__ ((format (printf, 3, 4)));
1478 extern void ext4_grp_locked_error(struct super_block *, ext4_group_t,
1479 				const char *, const char *, ...)
1480 	__attribute__ ((format (printf, 4, 5)));
1481 extern void ext4_update_dynamic_rev(struct super_block *sb);
1482 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1483 					__u32 compat);
1484 extern int ext4_update_rocompat_feature(handle_t *handle,
1485 					struct super_block *sb,	__u32 rocompat);
1486 extern int ext4_update_incompat_feature(handle_t *handle,
1487 					struct super_block *sb,	__u32 incompat);
1488 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1489 				      struct ext4_group_desc *bg);
1490 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1491 				      struct ext4_group_desc *bg);
1492 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1493 				     struct ext4_group_desc *bg);
1494 extern __u32 ext4_free_blks_count(struct super_block *sb,
1495 				struct ext4_group_desc *bg);
1496 extern __u32 ext4_free_inodes_count(struct super_block *sb,
1497 				 struct ext4_group_desc *bg);
1498 extern __u32 ext4_used_dirs_count(struct super_block *sb,
1499 				struct ext4_group_desc *bg);
1500 extern __u32 ext4_itable_unused_count(struct super_block *sb,
1501 				   struct ext4_group_desc *bg);
1502 extern void ext4_block_bitmap_set(struct super_block *sb,
1503 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1504 extern void ext4_inode_bitmap_set(struct super_block *sb,
1505 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1506 extern void ext4_inode_table_set(struct super_block *sb,
1507 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
1508 extern void ext4_free_blks_set(struct super_block *sb,
1509 			       struct ext4_group_desc *bg, __u32 count);
1510 extern void ext4_free_inodes_set(struct super_block *sb,
1511 				struct ext4_group_desc *bg, __u32 count);
1512 extern void ext4_used_dirs_set(struct super_block *sb,
1513 				struct ext4_group_desc *bg, __u32 count);
1514 extern void ext4_itable_unused_set(struct super_block *sb,
1515 				   struct ext4_group_desc *bg, __u32 count);
1516 extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
1517 				   struct ext4_group_desc *gdp);
1518 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
1519 				       struct ext4_group_desc *gdp);
1520 
1521 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
1522 {
1523 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
1524 		le32_to_cpu(es->s_blocks_count_lo);
1525 }
1526 
1527 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
1528 {
1529 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
1530 		le32_to_cpu(es->s_r_blocks_count_lo);
1531 }
1532 
1533 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
1534 {
1535 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
1536 		le32_to_cpu(es->s_free_blocks_count_lo);
1537 }
1538 
1539 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
1540 					 ext4_fsblk_t blk)
1541 {
1542 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
1543 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
1544 }
1545 
1546 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
1547 					      ext4_fsblk_t blk)
1548 {
1549 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
1550 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
1551 }
1552 
1553 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
1554 					   ext4_fsblk_t blk)
1555 {
1556 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
1557 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
1558 }
1559 
1560 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
1561 {
1562 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
1563 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
1564 			le32_to_cpu(raw_inode->i_size_lo);
1565 	else
1566 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
1567 }
1568 
1569 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
1570 {
1571 	raw_inode->i_size_lo = cpu_to_le32(i_size);
1572 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
1573 }
1574 
1575 static inline
1576 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
1577 					    ext4_group_t group)
1578 {
1579 	 struct ext4_group_info ***grp_info;
1580 	 long indexv, indexh;
1581 	 grp_info = EXT4_SB(sb)->s_group_info;
1582 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
1583 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
1584 	 return grp_info[indexv][indexh];
1585 }
1586 
1587 /*
1588  * Reading s_groups_count requires using smp_rmb() afterwards.  See
1589  * the locking protocol documented in the comments of ext4_group_add()
1590  * in resize.c
1591  */
1592 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
1593 {
1594 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
1595 
1596 	smp_rmb();
1597 	return ngroups;
1598 }
1599 
1600 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
1601 					     ext4_group_t block_group)
1602 {
1603 	return block_group >> sbi->s_log_groups_per_flex;
1604 }
1605 
1606 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
1607 {
1608 	return 1 << sbi->s_log_groups_per_flex;
1609 }
1610 
1611 #define ext4_std_error(sb, errno)				\
1612 do {								\
1613 	if ((errno))						\
1614 		__ext4_std_error((sb), __func__, (errno));	\
1615 } while (0)
1616 
1617 #ifdef CONFIG_SMP
1618 /* Each CPU can accumulate percpu_counter_batch blocks in their local
1619  * counters. So we need to make sure we have free blocks more
1620  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
1621  */
1622 #define EXT4_FREEBLOCKS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
1623 #else
1624 #define EXT4_FREEBLOCKS_WATERMARK 0
1625 #endif
1626 
1627 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
1628 {
1629 	/*
1630 	 * XXX: replace with spinlock if seen contended -bzzz
1631 	 */
1632 	down_write(&EXT4_I(inode)->i_data_sem);
1633 	if (newsize > EXT4_I(inode)->i_disksize)
1634 		EXT4_I(inode)->i_disksize = newsize;
1635 	up_write(&EXT4_I(inode)->i_data_sem);
1636 	return ;
1637 }
1638 
1639 struct ext4_group_info {
1640 	unsigned long   bb_state;
1641 	struct rb_root  bb_free_root;
1642 	ext4_grpblk_t	bb_first_free;	/* first free block */
1643 	ext4_grpblk_t	bb_free;	/* total free blocks */
1644 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
1645 	struct          list_head bb_prealloc_list;
1646 #ifdef DOUBLE_CHECK
1647 	void            *bb_bitmap;
1648 #endif
1649 	struct rw_semaphore alloc_sem;
1650 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
1651 					 * regions, index is order.
1652 					 * bb_counters[3] = 5 means
1653 					 * 5 free 8-block regions. */
1654 };
1655 
1656 #define EXT4_GROUP_INFO_NEED_INIT_BIT	0
1657 
1658 #define EXT4_MB_GRP_NEED_INIT(grp)	\
1659 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
1660 
1661 #define EXT4_MAX_CONTENTION		8
1662 #define EXT4_CONTENTION_THRESHOLD	2
1663 
1664 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
1665 					      ext4_group_t group)
1666 {
1667 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
1668 }
1669 
1670 /*
1671  * Returns true if the filesystem is busy enough that attempts to
1672  * access the block group locks has run into contention.
1673  */
1674 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
1675 {
1676 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
1677 }
1678 
1679 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
1680 {
1681 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
1682 	if (spin_trylock(lock))
1683 		/*
1684 		 * We're able to grab the lock right away, so drop the
1685 		 * lock contention counter.
1686 		 */
1687 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
1688 	else {
1689 		/*
1690 		 * The lock is busy, so bump the contention counter,
1691 		 * and then wait on the spin lock.
1692 		 */
1693 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
1694 				  EXT4_MAX_CONTENTION);
1695 		spin_lock(lock);
1696 	}
1697 }
1698 
1699 static inline void ext4_unlock_group(struct super_block *sb,
1700 					ext4_group_t group)
1701 {
1702 	spin_unlock(ext4_group_lock_ptr(sb, group));
1703 }
1704 
1705 /*
1706  * Inodes and files operations
1707  */
1708 
1709 /* dir.c */
1710 extern const struct file_operations ext4_dir_operations;
1711 
1712 /* file.c */
1713 extern const struct inode_operations ext4_file_inode_operations;
1714 extern const struct file_operations ext4_file_operations;
1715 
1716 /* namei.c */
1717 extern const struct inode_operations ext4_dir_inode_operations;
1718 extern const struct inode_operations ext4_special_inode_operations;
1719 extern struct dentry *ext4_get_parent(struct dentry *child);
1720 
1721 /* symlink.c */
1722 extern const struct inode_operations ext4_symlink_inode_operations;
1723 extern const struct inode_operations ext4_fast_symlink_inode_operations;
1724 
1725 /* block_validity */
1726 extern void ext4_release_system_zone(struct super_block *sb);
1727 extern int ext4_setup_system_zone(struct super_block *sb);
1728 extern int __init init_ext4_system_zone(void);
1729 extern void exit_ext4_system_zone(void);
1730 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
1731 				 ext4_fsblk_t start_blk,
1732 				 unsigned int count);
1733 
1734 /* extents.c */
1735 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
1736 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
1737 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
1738 				       int chunk);
1739 extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
1740 			       ext4_lblk_t iblock, unsigned int max_blocks,
1741 			       struct buffer_head *bh_result, int flags);
1742 extern void ext4_ext_truncate(struct inode *);
1743 extern void ext4_ext_init(struct super_block *);
1744 extern void ext4_ext_release(struct super_block *);
1745 extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
1746 			  loff_t len);
1747 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
1748 			  loff_t len);
1749 extern int ext4_get_blocks(handle_t *handle, struct inode *inode,
1750 			   sector_t block, unsigned int max_blocks,
1751 			   struct buffer_head *bh, int flags);
1752 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1753 			__u64 start, __u64 len);
1754 /* move_extent.c */
1755 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
1756 			     __u64 start_orig, __u64 start_donor,
1757 			     __u64 len, __u64 *moved_len);
1758 
1759 
1760 /*
1761  * Add new method to test wether block and inode bitmaps are properly
1762  * initialized. With uninit_bg reading the block from disk is not enough
1763  * to mark the bitmap uptodate. We need to also zero-out the bitmap
1764  */
1765 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
1766 
1767 static inline int bitmap_uptodate(struct buffer_head *bh)
1768 {
1769 	return (buffer_uptodate(bh) &&
1770 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
1771 }
1772 static inline void set_bitmap_uptodate(struct buffer_head *bh)
1773 {
1774 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
1775 }
1776 
1777 #endif	/* __KERNEL__ */
1778 
1779 #endif	/* _EXT4_H */
1780