xref: /openbmc/linux/fs/ext4/ext4.h (revision f19d5870)
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 #include <crypto/hash.h>
33 #ifdef __KERNEL__
34 #include <linux/compat.h>
35 #endif
36 
37 /*
38  * The fourth extended filesystem constants/structures
39  */
40 
41 /*
42  * Define EXT4FS_DEBUG to produce debug messages
43  */
44 #undef EXT4FS_DEBUG
45 
46 /*
47  * Debug code
48  */
49 #ifdef EXT4FS_DEBUG
50 #define ext4_debug(f, a...)						\
51 	do {								\
52 		printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",	\
53 			__FILE__, __LINE__, __func__);			\
54 		printk(KERN_DEBUG f, ## a);				\
55 	} while (0)
56 #else
57 #define ext4_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
58 #endif
59 
60 /*
61  * Turn on EXT_DEBUG to get lots of info about extents operations.
62  */
63 #define EXT_DEBUG__
64 #ifdef EXT_DEBUG
65 #define ext_debug(fmt, ...)	printk(fmt, ##__VA_ARGS__)
66 #else
67 #define ext_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
68 #endif
69 
70 #define EXT4_ERROR_INODE(inode, fmt, a...) \
71 	ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
72 
73 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)			\
74 	ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
75 
76 #define EXT4_ERROR_FILE(file, block, fmt, a...)				\
77 	ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
78 
79 /* data type for block offset of block group */
80 typedef int ext4_grpblk_t;
81 
82 /* data type for filesystem-wide blocks number */
83 typedef unsigned long long ext4_fsblk_t;
84 
85 /* data type for file logical block number */
86 typedef __u32 ext4_lblk_t;
87 
88 /* data type for block group number */
89 typedef unsigned int ext4_group_t;
90 
91 /*
92  * Flags used in mballoc's allocation_context flags field.
93  *
94  * Also used to show what's going on for debugging purposes when the
95  * flag field is exported via the traceport interface
96  */
97 
98 /* prefer goal again. length */
99 #define EXT4_MB_HINT_MERGE		0x0001
100 /* blocks already reserved */
101 #define EXT4_MB_HINT_RESERVED		0x0002
102 /* metadata is being allocated */
103 #define EXT4_MB_HINT_METADATA		0x0004
104 /* first blocks in the file */
105 #define EXT4_MB_HINT_FIRST		0x0008
106 /* search for the best chunk */
107 #define EXT4_MB_HINT_BEST		0x0010
108 /* data is being allocated */
109 #define EXT4_MB_HINT_DATA		0x0020
110 /* don't preallocate (for tails) */
111 #define EXT4_MB_HINT_NOPREALLOC		0x0040
112 /* allocate for locality group */
113 #define EXT4_MB_HINT_GROUP_ALLOC	0x0080
114 /* allocate goal blocks or none */
115 #define EXT4_MB_HINT_GOAL_ONLY		0x0100
116 /* goal is meaningful */
117 #define EXT4_MB_HINT_TRY_GOAL		0x0200
118 /* blocks already pre-reserved by delayed allocation */
119 #define EXT4_MB_DELALLOC_RESERVED	0x0400
120 /* We are doing stream allocation */
121 #define EXT4_MB_STREAM_ALLOC		0x0800
122 /* Use reserved root blocks if needed */
123 #define EXT4_MB_USE_ROOT_BLOCKS		0x1000
124 
125 struct ext4_allocation_request {
126 	/* target inode for block we're allocating */
127 	struct inode *inode;
128 	/* how many blocks we want to allocate */
129 	unsigned int len;
130 	/* logical block in target inode */
131 	ext4_lblk_t logical;
132 	/* the closest logical allocated block to the left */
133 	ext4_lblk_t lleft;
134 	/* the closest logical allocated block to the right */
135 	ext4_lblk_t lright;
136 	/* phys. target (a hint) */
137 	ext4_fsblk_t goal;
138 	/* phys. block for the closest logical allocated block to the left */
139 	ext4_fsblk_t pleft;
140 	/* phys. block for the closest logical allocated block to the right */
141 	ext4_fsblk_t pright;
142 	/* flags. see above EXT4_MB_HINT_* */
143 	unsigned int flags;
144 };
145 
146 /*
147  * Logical to physical block mapping, used by ext4_map_blocks()
148  *
149  * This structure is used to pass requests into ext4_map_blocks() as
150  * well as to store the information returned by ext4_map_blocks().  It
151  * takes less room on the stack than a struct buffer_head.
152  */
153 #define EXT4_MAP_NEW		(1 << BH_New)
154 #define EXT4_MAP_MAPPED		(1 << BH_Mapped)
155 #define EXT4_MAP_UNWRITTEN	(1 << BH_Unwritten)
156 #define EXT4_MAP_BOUNDARY	(1 << BH_Boundary)
157 #define EXT4_MAP_UNINIT		(1 << BH_Uninit)
158 /* Sometimes (in the bigalloc case, from ext4_da_get_block_prep) the caller of
159  * ext4_map_blocks wants to know whether or not the underlying cluster has
160  * already been accounted for. EXT4_MAP_FROM_CLUSTER conveys to the caller that
161  * the requested mapping was from previously mapped (or delayed allocated)
162  * cluster. We use BH_AllocFromCluster only for this flag. BH_AllocFromCluster
163  * should never appear on buffer_head's state flags.
164  */
165 #define EXT4_MAP_FROM_CLUSTER	(1 << BH_AllocFromCluster)
166 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
167 				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
168 				 EXT4_MAP_UNINIT | EXT4_MAP_FROM_CLUSTER)
169 
170 struct ext4_map_blocks {
171 	ext4_fsblk_t m_pblk;
172 	ext4_lblk_t m_lblk;
173 	unsigned int m_len;
174 	unsigned int m_flags;
175 };
176 
177 /*
178  * For delayed allocation tracking
179  */
180 struct mpage_da_data {
181 	struct inode *inode;
182 	sector_t b_blocknr;		/* start block number of extent */
183 	size_t b_size;			/* size of extent */
184 	unsigned long b_state;		/* state of the extent */
185 	unsigned long first_page, next_page;	/* extent of pages */
186 	struct writeback_control *wbc;
187 	int io_done;
188 	int pages_written;
189 	int retval;
190 };
191 
192 /*
193  * Flags for ext4_io_end->flags
194  */
195 #define	EXT4_IO_END_UNWRITTEN	0x0001
196 #define EXT4_IO_END_ERROR	0x0002
197 #define EXT4_IO_END_QUEUED	0x0004
198 #define EXT4_IO_END_DIRECT	0x0008
199 
200 struct ext4_io_page {
201 	struct page	*p_page;
202 	atomic_t	p_count;
203 };
204 
205 #define MAX_IO_PAGES 128
206 
207 /*
208  * For converting uninitialized extents on a work queue.
209  *
210  * 'page' is only used from the writepage() path; 'pages' is only used for
211  * buffered writes; they are used to keep page references until conversion
212  * takes place.  For AIO/DIO, neither field is filled in.
213  */
214 typedef struct ext4_io_end {
215 	struct list_head	list;		/* per-file finished IO list */
216 	struct inode		*inode;		/* file being written to */
217 	unsigned int		flag;		/* unwritten or not */
218 	struct page		*page;		/* for writepage() path */
219 	loff_t			offset;		/* offset in the file */
220 	ssize_t			size;		/* size of the extent */
221 	struct work_struct	work;		/* data work queue */
222 	struct kiocb		*iocb;		/* iocb struct for AIO */
223 	int			result;		/* error value for AIO */
224 	int			num_io_pages;   /* for writepages() */
225 	struct ext4_io_page	*pages[MAX_IO_PAGES]; /* for writepages() */
226 } ext4_io_end_t;
227 
228 struct ext4_io_submit {
229 	int			io_op;
230 	struct bio		*io_bio;
231 	ext4_io_end_t		*io_end;
232 	struct ext4_io_page	*io_page;
233 	sector_t		io_next_block;
234 };
235 
236 /*
237  * Special inodes numbers
238  */
239 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
240 #define EXT4_ROOT_INO		 2	/* Root inode */
241 #define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
242 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
243 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
244 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
245 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
246 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
247 
248 /* First non-reserved inode for old ext4 filesystems */
249 #define EXT4_GOOD_OLD_FIRST_INO	11
250 
251 /*
252  * Maximal count of links to a file
253  */
254 #define EXT4_LINK_MAX		65000
255 
256 /*
257  * Macro-instructions used to manage several block sizes
258  */
259 #define EXT4_MIN_BLOCK_SIZE		1024
260 #define	EXT4_MAX_BLOCK_SIZE		65536
261 #define EXT4_MIN_BLOCK_LOG_SIZE		10
262 #define EXT4_MAX_BLOCK_LOG_SIZE		16
263 #ifdef __KERNEL__
264 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
265 #else
266 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
267 #endif
268 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
269 #define EXT4_CLUSTER_SIZE(s)		(EXT4_BLOCK_SIZE(s) << \
270 					 EXT4_SB(s)->s_cluster_bits)
271 #ifdef __KERNEL__
272 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
273 # define EXT4_CLUSTER_BITS(s)		(EXT4_SB(s)->s_cluster_bits)
274 #else
275 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
276 #endif
277 #ifdef __KERNEL__
278 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
279 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
280 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
281 #else
282 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
283 				 EXT4_GOOD_OLD_INODE_SIZE : \
284 				 (s)->s_inode_size)
285 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
286 				 EXT4_GOOD_OLD_FIRST_INO : \
287 				 (s)->s_first_ino)
288 #endif
289 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
290 
291 /* Translate a block number to a cluster number */
292 #define EXT4_B2C(sbi, blk)	((blk) >> (sbi)->s_cluster_bits)
293 /* Translate a cluster number to a block number */
294 #define EXT4_C2B(sbi, cluster)	((cluster) << (sbi)->s_cluster_bits)
295 /* Translate # of blks to # of clusters */
296 #define EXT4_NUM_B2C(sbi, blks)	(((blks) + (sbi)->s_cluster_ratio - 1) >> \
297 				 (sbi)->s_cluster_bits)
298 
299 /*
300  * Structure of a blocks group descriptor
301  */
302 struct ext4_group_desc
303 {
304 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
305 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
306 	__le32	bg_inode_table_lo;	/* Inodes table block */
307 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
308 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
309 	__le16	bg_used_dirs_count_lo;	/* Directories count */
310 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
311 	__le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
312 	__le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
313 	__le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
314 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
315 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
316 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
317 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
318 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
319 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
320 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
321 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
322 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
323 	__le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
324 	__le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
325 	__le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
326 	__u32   bg_reserved;
327 };
328 
329 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END	\
330 	(offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
331 	 sizeof(__le16))
332 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END	\
333 	(offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
334 	 sizeof(__le16))
335 
336 /*
337  * Structure of a flex block group info
338  */
339 
340 struct flex_groups {
341 	atomic_t free_inodes;
342 	atomic_t free_clusters;
343 	atomic_t used_dirs;
344 };
345 
346 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
347 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
348 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
349 
350 /*
351  * Macro-instructions used to manage group descriptors
352  */
353 #define EXT4_MIN_DESC_SIZE		32
354 #define EXT4_MIN_DESC_SIZE_64BIT	64
355 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
356 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
357 #ifdef __KERNEL__
358 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
359 # define EXT4_CLUSTERS_PER_GROUP(s)	(EXT4_SB(s)->s_clusters_per_group)
360 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
361 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
362 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
363 #else
364 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
365 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
366 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
367 #endif
368 
369 /*
370  * Constants relative to the data blocks
371  */
372 #define	EXT4_NDIR_BLOCKS		12
373 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
374 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
375 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
376 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
377 
378 /*
379  * Inode flags
380  */
381 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
382 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
383 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
384 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
385 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
386 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
387 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
388 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
389 /* Reserved for compression usage... */
390 #define EXT4_DIRTY_FL			0x00000100
391 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
392 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
393 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
394 /* End compression flags --- maybe not all used */
395 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
396 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
397 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
398 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
399 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
400 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
401 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
402 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
403 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
404 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
405 #define EXT4_INLINE_DATA_FL		0x10000000 /* Inode has inline data. */
406 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
407 
408 #define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
409 #define EXT4_FL_USER_MODIFIABLE		0x004B80FF /* User modifiable flags */
410 
411 /* Flags that should be inherited by new inodes from their parent. */
412 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
413 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
414 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
415 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
416 
417 /* Flags that are appropriate for regular files (all but dir-specific ones). */
418 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
419 
420 /* Flags that are appropriate for non-directories/regular files. */
421 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
422 
423 /* Mask out flags that are inappropriate for the given type of inode. */
424 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
425 {
426 	if (S_ISDIR(mode))
427 		return flags;
428 	else if (S_ISREG(mode))
429 		return flags & EXT4_REG_FLMASK;
430 	else
431 		return flags & EXT4_OTHER_FLMASK;
432 }
433 
434 /*
435  * Inode flags used for atomic set/get
436  */
437 enum {
438 	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
439 	EXT4_INODE_UNRM		= 1,	/* Undelete */
440 	EXT4_INODE_COMPR	= 2,	/* Compress file */
441 	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
442 	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
443 	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
444 	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
445 	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
446 /* Reserved for compression usage... */
447 	EXT4_INODE_DIRTY	= 8,
448 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
449 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
450 	EXT4_INODE_ECOMPR	= 11,	/* Compression error */
451 /* End compression flags --- maybe not all used */
452 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
453 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
454 	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
455 	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
456 	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
457 	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
458 	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
459 	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
460 	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
461 	EXT4_INODE_EOFBLOCKS	= 22,	/* Blocks allocated beyond EOF */
462 	EXT4_INODE_INLINE_DATA	= 28,	/* Data in inode. */
463 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
464 };
465 
466 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
467 #define CHECK_FLAG_VALUE(FLAG) if (!TEST_FLAG_VALUE(FLAG)) { \
468 	printk(KERN_EMERG "EXT4 flag fail: " #FLAG ": %d %d\n", \
469 		EXT4_##FLAG##_FL, EXT4_INODE_##FLAG); BUG_ON(1); }
470 
471 /*
472  * Since it's pretty easy to mix up bit numbers and hex values, and we
473  * can't do a compile-time test for ENUM values, we use a run-time
474  * test to make sure that EXT4_XXX_FL is consistent with respect to
475  * EXT4_INODE_XXX.  If all is well the printk and BUG_ON will all drop
476  * out so it won't cost any extra space in the compiled kernel image.
477  * But it's important that these values are the same, since we are
478  * using EXT4_INODE_XXX to test for the flag values, but EXT4_XX_FL
479  * must be consistent with the values of FS_XXX_FL defined in
480  * include/linux/fs.h and the on-disk values found in ext2, ext3, and
481  * ext4 filesystems, and of course the values defined in e2fsprogs.
482  *
483  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
484  */
485 static inline void ext4_check_flag_values(void)
486 {
487 	CHECK_FLAG_VALUE(SECRM);
488 	CHECK_FLAG_VALUE(UNRM);
489 	CHECK_FLAG_VALUE(COMPR);
490 	CHECK_FLAG_VALUE(SYNC);
491 	CHECK_FLAG_VALUE(IMMUTABLE);
492 	CHECK_FLAG_VALUE(APPEND);
493 	CHECK_FLAG_VALUE(NODUMP);
494 	CHECK_FLAG_VALUE(NOATIME);
495 	CHECK_FLAG_VALUE(DIRTY);
496 	CHECK_FLAG_VALUE(COMPRBLK);
497 	CHECK_FLAG_VALUE(NOCOMPR);
498 	CHECK_FLAG_VALUE(ECOMPR);
499 	CHECK_FLAG_VALUE(INDEX);
500 	CHECK_FLAG_VALUE(IMAGIC);
501 	CHECK_FLAG_VALUE(JOURNAL_DATA);
502 	CHECK_FLAG_VALUE(NOTAIL);
503 	CHECK_FLAG_VALUE(DIRSYNC);
504 	CHECK_FLAG_VALUE(TOPDIR);
505 	CHECK_FLAG_VALUE(HUGE_FILE);
506 	CHECK_FLAG_VALUE(EXTENTS);
507 	CHECK_FLAG_VALUE(EA_INODE);
508 	CHECK_FLAG_VALUE(EOFBLOCKS);
509 	CHECK_FLAG_VALUE(INLINE_DATA);
510 	CHECK_FLAG_VALUE(RESERVED);
511 }
512 
513 /* Used to pass group descriptor data when online resize is done */
514 struct ext4_new_group_input {
515 	__u32 group;		/* Group number for this data */
516 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
517 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
518 	__u64 inode_table;	/* Absolute block number of inode table start */
519 	__u32 blocks_count;	/* Total number of blocks in this group */
520 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
521 	__u16 unused;
522 };
523 
524 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
525 struct compat_ext4_new_group_input {
526 	u32 group;
527 	compat_u64 block_bitmap;
528 	compat_u64 inode_bitmap;
529 	compat_u64 inode_table;
530 	u32 blocks_count;
531 	u16 reserved_blocks;
532 	u16 unused;
533 };
534 #endif
535 
536 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
537 struct ext4_new_group_data {
538 	__u32 group;
539 	__u64 block_bitmap;
540 	__u64 inode_bitmap;
541 	__u64 inode_table;
542 	__u32 blocks_count;
543 	__u16 reserved_blocks;
544 	__u16 unused;
545 	__u32 free_blocks_count;
546 };
547 
548 /* Indexes used to index group tables in ext4_new_group_data */
549 enum {
550 	BLOCK_BITMAP = 0,	/* block bitmap */
551 	INODE_BITMAP,		/* inode bitmap */
552 	INODE_TABLE,		/* inode tables */
553 	GROUP_TABLE_COUNT,
554 };
555 
556 /*
557  * Flags used by ext4_map_blocks()
558  */
559 	/* Allocate any needed blocks and/or convert an unitialized
560 	   extent to be an initialized ext4 */
561 #define EXT4_GET_BLOCKS_CREATE			0x0001
562 	/* Request the creation of an unitialized extent */
563 #define EXT4_GET_BLOCKS_UNINIT_EXT		0x0002
564 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\
565 						 EXT4_GET_BLOCKS_CREATE)
566 	/* Caller is from the delayed allocation writeout path,
567 	   so set the magic i_delalloc_reserve_flag after taking the
568 	   inode allocation semaphore for */
569 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
570 	/* caller is from the direct IO path, request to creation of an
571 	unitialized extents if not allocated, split the uninitialized
572 	extent if blocks has been preallocated already*/
573 #define EXT4_GET_BLOCKS_PRE_IO			0x0008
574 #define EXT4_GET_BLOCKS_CONVERT			0x0010
575 #define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
576 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
577 	/* Convert extent to initialized after IO complete */
578 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
579 					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
580 	/* Punch out blocks of an extent */
581 #define EXT4_GET_BLOCKS_PUNCH_OUT_EXT		0x0020
582 	/* Don't normalize allocation size (used for fallocate) */
583 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
584 	/* Request will not result in inode size update (user for fallocate) */
585 #define EXT4_GET_BLOCKS_KEEP_SIZE		0x0080
586 	/* Do not take i_data_sem locking in ext4_map_blocks */
587 #define EXT4_GET_BLOCKS_NO_LOCK			0x0100
588 
589 /*
590  * Flags used by ext4_free_blocks
591  */
592 #define EXT4_FREE_BLOCKS_METADATA	0x0001
593 #define EXT4_FREE_BLOCKS_FORGET		0x0002
594 #define EXT4_FREE_BLOCKS_VALIDATED	0x0004
595 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE	0x0008
596 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
597 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
598 
599 /*
600  * Flags used by ext4_discard_partial_page_buffers
601  */
602 #define EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED	0x0001
603 
604 /*
605  * ioctl commands
606  */
607 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
608 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
609 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
610 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
611 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
612 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
613 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
614 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
615 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
616 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
617 #define EXT4_IOC_MIGRATE		_IO('f', 9)
618  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
619  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
620 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
621 #define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
622 #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
623 
624 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
625 /*
626  * ioctl commands in 32 bit emulation
627  */
628 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
629 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
630 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
631 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
632 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
633 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
634 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
635 #define EXT4_IOC32_GROUP_ADD		_IOW('f', 8, struct compat_ext4_new_group_input)
636 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
637 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
638 #endif
639 
640 /* Max physical block we can address w/o extents */
641 #define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF
642 
643 /*
644  * Structure of an inode on the disk
645  */
646 struct ext4_inode {
647 	__le16	i_mode;		/* File mode */
648 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
649 	__le32	i_size_lo;	/* Size in bytes */
650 	__le32	i_atime;	/* Access time */
651 	__le32	i_ctime;	/* Inode Change time */
652 	__le32	i_mtime;	/* Modification time */
653 	__le32	i_dtime;	/* Deletion Time */
654 	__le16	i_gid;		/* Low 16 bits of Group Id */
655 	__le16	i_links_count;	/* Links count */
656 	__le32	i_blocks_lo;	/* Blocks count */
657 	__le32	i_flags;	/* File flags */
658 	union {
659 		struct {
660 			__le32  l_i_version;
661 		} linux1;
662 		struct {
663 			__u32  h_i_translator;
664 		} hurd1;
665 		struct {
666 			__u32  m_i_reserved1;
667 		} masix1;
668 	} osd1;				/* OS dependent 1 */
669 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
670 	__le32	i_generation;	/* File version (for NFS) */
671 	__le32	i_file_acl_lo;	/* File ACL */
672 	__le32	i_size_high;
673 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
674 	union {
675 		struct {
676 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
677 			__le16	l_i_file_acl_high;
678 			__le16	l_i_uid_high;	/* these 2 fields */
679 			__le16	l_i_gid_high;	/* were reserved2[0] */
680 			__le16	l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
681 			__le16	l_i_reserved;
682 		} linux2;
683 		struct {
684 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
685 			__u16	h_i_mode_high;
686 			__u16	h_i_uid_high;
687 			__u16	h_i_gid_high;
688 			__u32	h_i_author;
689 		} hurd2;
690 		struct {
691 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
692 			__le16	m_i_file_acl_high;
693 			__u32	m_i_reserved2[2];
694 		} masix2;
695 	} osd2;				/* OS dependent 2 */
696 	__le16	i_extra_isize;
697 	__le16	i_checksum_hi;	/* crc32c(uuid+inum+inode) BE */
698 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
699 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
700 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
701 	__le32  i_crtime;       /* File Creation time */
702 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
703 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
704 };
705 
706 struct move_extent {
707 	__u32 reserved;		/* should be zero */
708 	__u32 donor_fd;		/* donor file descriptor */
709 	__u64 orig_start;	/* logical start offset in block for orig */
710 	__u64 donor_start;	/* logical start offset in block for donor */
711 	__u64 len;		/* block length to be moved */
712 	__u64 moved_len;	/* moved block length */
713 };
714 
715 #define EXT4_EPOCH_BITS 2
716 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
717 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
718 
719 /*
720  * Extended fields will fit into an inode if the filesystem was formatted
721  * with large inodes (-I 256 or larger) and there are not currently any EAs
722  * consuming all of the available space. For new inodes we always reserve
723  * enough space for the kernel's known extended fields, but for inodes
724  * created with an old kernel this might not have been the case. None of
725  * the extended inode fields is critical for correct filesystem operation.
726  * This macro checks if a certain field fits in the inode. Note that
727  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
728  */
729 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
730 	((offsetof(typeof(*ext4_inode), field) +	\
731 	  sizeof((ext4_inode)->field))			\
732 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
733 	    (einode)->i_extra_isize))			\
734 
735 static inline __le32 ext4_encode_extra_time(struct timespec *time)
736 {
737        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
738 			   (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
739                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
740 }
741 
742 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
743 {
744        if (sizeof(time->tv_sec) > 4)
745 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
746 			       << 32;
747        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
748 }
749 
750 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
751 do {									       \
752 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
753 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
754 		(raw_inode)->xtime ## _extra =				       \
755 				ext4_encode_extra_time(&(inode)->xtime);       \
756 } while (0)
757 
758 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
759 do {									       \
760 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
761 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
762 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
763 		(raw_inode)->xtime ## _extra =				       \
764 				ext4_encode_extra_time(&(einode)->xtime);      \
765 } while (0)
766 
767 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
768 do {									       \
769 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
770 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
771 		ext4_decode_extra_time(&(inode)->xtime,			       \
772 				       raw_inode->xtime ## _extra);	       \
773 	else								       \
774 		(inode)->xtime.tv_nsec = 0;				       \
775 } while (0)
776 
777 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
778 do {									       \
779 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
780 		(einode)->xtime.tv_sec = 				       \
781 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
782 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
783 		ext4_decode_extra_time(&(einode)->xtime,		       \
784 				       raw_inode->xtime ## _extra);	       \
785 	else								       \
786 		(einode)->xtime.tv_nsec = 0;				       \
787 } while (0)
788 
789 #define i_disk_version osd1.linux1.l_i_version
790 
791 #if defined(__KERNEL__) || defined(__linux__)
792 #define i_reserved1	osd1.linux1.l_i_reserved1
793 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
794 #define i_blocks_high	osd2.linux2.l_i_blocks_high
795 #define i_uid_low	i_uid
796 #define i_gid_low	i_gid
797 #define i_uid_high	osd2.linux2.l_i_uid_high
798 #define i_gid_high	osd2.linux2.l_i_gid_high
799 #define i_checksum_lo	osd2.linux2.l_i_checksum_lo
800 
801 #elif defined(__GNU__)
802 
803 #define i_translator	osd1.hurd1.h_i_translator
804 #define i_uid_high	osd2.hurd2.h_i_uid_high
805 #define i_gid_high	osd2.hurd2.h_i_gid_high
806 #define i_author	osd2.hurd2.h_i_author
807 
808 #elif defined(__masix__)
809 
810 #define i_reserved1	osd1.masix1.m_i_reserved1
811 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
812 #define i_reserved2	osd2.masix2.m_i_reserved2
813 
814 #endif /* defined(__KERNEL__) || defined(__linux__) */
815 
816 /*
817  * storage for cached extent
818  * If ec_len == 0, then the cache is invalid.
819  * If ec_start == 0, then the cache represents a gap (null mapping)
820  */
821 struct ext4_ext_cache {
822 	ext4_fsblk_t	ec_start;
823 	ext4_lblk_t	ec_block;
824 	__u32		ec_len; /* must be 32bit to return holes */
825 };
826 
827 #include "extents_status.h"
828 
829 /*
830  * fourth extended file system inode data in memory
831  */
832 struct ext4_inode_info {
833 	__le32	i_data[15];	/* unconverted */
834 	__u32	i_dtime;
835 	ext4_fsblk_t	i_file_acl;
836 
837 	/*
838 	 * i_block_group is the number of the block group which contains
839 	 * this file's inode.  Constant across the lifetime of the inode,
840 	 * it is ued for making block allocation decisions - we try to
841 	 * place a file's data blocks near its inode block, and new inodes
842 	 * near to their parent directory's inode.
843 	 */
844 	ext4_group_t	i_block_group;
845 	ext4_lblk_t	i_dir_start_lookup;
846 #if (BITS_PER_LONG < 64)
847 	unsigned long	i_state_flags;		/* Dynamic state flags */
848 #endif
849 	unsigned long	i_flags;
850 
851 #ifdef CONFIG_EXT4_FS_XATTR
852 	/*
853 	 * Extended attributes can be read independently of the main file
854 	 * data. Taking i_mutex even when reading would cause contention
855 	 * between readers of EAs and writers of regular file data, so
856 	 * instead we synchronize on xattr_sem when reading or changing
857 	 * EAs.
858 	 */
859 	struct rw_semaphore xattr_sem;
860 #endif
861 
862 	struct list_head i_orphan;	/* unlinked but open inodes */
863 
864 	/*
865 	 * i_disksize keeps track of what the inode size is ON DISK, not
866 	 * in memory.  During truncate, i_size is set to the new size by
867 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
868 	 * set i_disksize to 0 until the truncate is actually under way.
869 	 *
870 	 * The intent is that i_disksize always represents the blocks which
871 	 * are used by this file.  This allows recovery to restart truncate
872 	 * on orphans if we crash during truncate.  We actually write i_disksize
873 	 * into the on-disk inode when writing inodes out, instead of i_size.
874 	 *
875 	 * The only time when i_disksize and i_size may be different is when
876 	 * a truncate is in progress.  The only things which change i_disksize
877 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
878 	 */
879 	loff_t	i_disksize;
880 
881 	/*
882 	 * i_data_sem is for serialising ext4_truncate() against
883 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
884 	 * data tree are chopped off during truncate. We can't do that in
885 	 * ext4 because whenever we perform intermediate commits during
886 	 * truncate, the inode and all the metadata blocks *must* be in a
887 	 * consistent state which allows truncation of the orphans to restart
888 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
889 	 * by other means, so we have i_data_sem.
890 	 */
891 	struct rw_semaphore i_data_sem;
892 	struct inode vfs_inode;
893 	struct jbd2_inode *jinode;
894 
895 	struct ext4_ext_cache i_cached_extent;
896 	/*
897 	 * File creation time. Its function is same as that of
898 	 * struct timespec i_{a,c,m}time in the generic inode.
899 	 */
900 	struct timespec i_crtime;
901 
902 	/* mballoc */
903 	struct list_head i_prealloc_list;
904 	spinlock_t i_prealloc_lock;
905 
906 	/* extents status tree */
907 	struct ext4_es_tree i_es_tree;
908 	rwlock_t i_es_lock;
909 
910 	/* ialloc */
911 	ext4_group_t	i_last_alloc_group;
912 
913 	/* allocation reservation info for delalloc */
914 	/* In case of bigalloc, these refer to clusters rather than blocks */
915 	unsigned int i_reserved_data_blocks;
916 	unsigned int i_reserved_meta_blocks;
917 	unsigned int i_allocated_meta_blocks;
918 	ext4_lblk_t i_da_metadata_calc_last_lblock;
919 	int i_da_metadata_calc_len;
920 
921 	/* on-disk additional length */
922 	__u16 i_extra_isize;
923 
924 	/* Indicate the inline data space. */
925 	u16 i_inline_off;
926 	u16 i_inline_size;
927 
928 #ifdef CONFIG_QUOTA
929 	/* quota space reservation, managed internally by quota code */
930 	qsize_t i_reserved_quota;
931 #endif
932 
933 	/* completed IOs that might need unwritten extents handling */
934 	struct list_head i_completed_io_list;
935 	spinlock_t i_completed_io_lock;
936 	atomic_t i_ioend_count;	/* Number of outstanding io_end structs */
937 	atomic_t i_unwritten; /* Nr. of inflight conversions pending */
938 
939 	spinlock_t i_block_reservation_lock;
940 
941 	/*
942 	 * Transactions that contain inode's metadata needed to complete
943 	 * fsync and fdatasync, respectively.
944 	 */
945 	tid_t i_sync_tid;
946 	tid_t i_datasync_tid;
947 
948 	/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
949 	__u32 i_csum_seed;
950 };
951 
952 /*
953  * File system states
954  */
955 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
956 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
957 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
958 
959 /*
960  * Misc. filesystem flags
961  */
962 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
963 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
964 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
965 
966 /*
967  * Mount flags
968  */
969 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
970 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
971 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
972 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
973 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
974 #define EXT4_MOUNT_ERRORS_MASK		0x00070
975 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
976 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
977 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
978 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
979 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
980 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
981 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
982 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
983 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
984 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
985 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
986 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
987 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
988 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
989 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
990 #define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
991 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
992 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
993 #define EXT4_MOUNT_MBLK_IO_SUBMIT	0x4000000 /* multi-block io submits */
994 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
995 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
996 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
997 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
998 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
999 
1000 #define EXT4_MOUNT2_EXPLICIT_DELALLOC	0x00000001 /* User explicitly
1001 						      specified delalloc */
1002 
1003 #define clear_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt &= \
1004 						~EXT4_MOUNT_##opt
1005 #define set_opt(sb, opt)		EXT4_SB(sb)->s_mount_opt |= \
1006 						EXT4_MOUNT_##opt
1007 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
1008 					 EXT4_MOUNT_##opt)
1009 
1010 #define clear_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 &= \
1011 						~EXT4_MOUNT2_##opt
1012 #define set_opt2(sb, opt)		EXT4_SB(sb)->s_mount_opt2 |= \
1013 						EXT4_MOUNT2_##opt
1014 #define test_opt2(sb, opt)		(EXT4_SB(sb)->s_mount_opt2 & \
1015 					 EXT4_MOUNT2_##opt)
1016 
1017 #define ext4_test_and_set_bit		__test_and_set_bit_le
1018 #define ext4_set_bit			__set_bit_le
1019 #define ext4_set_bit_atomic		ext2_set_bit_atomic
1020 #define ext4_test_and_clear_bit		__test_and_clear_bit_le
1021 #define ext4_clear_bit			__clear_bit_le
1022 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
1023 #define ext4_test_bit			test_bit_le
1024 #define ext4_find_next_zero_bit		find_next_zero_bit_le
1025 #define ext4_find_next_bit		find_next_bit_le
1026 
1027 extern void ext4_set_bits(void *bm, int cur, int len);
1028 
1029 /*
1030  * Maximal mount counts between two filesystem checks
1031  */
1032 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
1033 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
1034 
1035 /*
1036  * Behaviour when detecting errors
1037  */
1038 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
1039 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
1040 #define EXT4_ERRORS_PANIC		3	/* Panic */
1041 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
1042 
1043 /* Metadata checksum algorithm codes */
1044 #define EXT4_CRC32C_CHKSUM		1
1045 
1046 /*
1047  * Structure of the super block
1048  */
1049 struct ext4_super_block {
1050 /*00*/	__le32	s_inodes_count;		/* Inodes count */
1051 	__le32	s_blocks_count_lo;	/* Blocks count */
1052 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
1053 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
1054 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
1055 	__le32	s_first_data_block;	/* First Data Block */
1056 	__le32	s_log_block_size;	/* Block size */
1057 	__le32	s_log_cluster_size;	/* Allocation cluster size */
1058 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
1059 	__le32	s_clusters_per_group;	/* # Clusters per group */
1060 	__le32	s_inodes_per_group;	/* # Inodes per group */
1061 	__le32	s_mtime;		/* Mount time */
1062 /*30*/	__le32	s_wtime;		/* Write time */
1063 	__le16	s_mnt_count;		/* Mount count */
1064 	__le16	s_max_mnt_count;	/* Maximal mount count */
1065 	__le16	s_magic;		/* Magic signature */
1066 	__le16	s_state;		/* File system state */
1067 	__le16	s_errors;		/* Behaviour when detecting errors */
1068 	__le16	s_minor_rev_level;	/* minor revision level */
1069 /*40*/	__le32	s_lastcheck;		/* time of last check */
1070 	__le32	s_checkinterval;	/* max. time between checks */
1071 	__le32	s_creator_os;		/* OS */
1072 	__le32	s_rev_level;		/* Revision level */
1073 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
1074 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
1075 	/*
1076 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
1077 	 *
1078 	 * Note: the difference between the compatible feature set and
1079 	 * the incompatible feature set is that if there is a bit set
1080 	 * in the incompatible feature set that the kernel doesn't
1081 	 * know about, it should refuse to mount the filesystem.
1082 	 *
1083 	 * e2fsck's requirements are more strict; if it doesn't know
1084 	 * about a feature in either the compatible or incompatible
1085 	 * feature set, it must abort and not try to meddle with
1086 	 * things it doesn't understand...
1087 	 */
1088 	__le32	s_first_ino;		/* First non-reserved inode */
1089 	__le16  s_inode_size;		/* size of inode structure */
1090 	__le16	s_block_group_nr;	/* block group # of this superblock */
1091 	__le32	s_feature_compat;	/* compatible feature set */
1092 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
1093 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
1094 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
1095 /*78*/	char	s_volume_name[16];	/* volume name */
1096 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
1097 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
1098 	/*
1099 	 * Performance hints.  Directory preallocation should only
1100 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1101 	 */
1102 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
1103 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
1104 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
1105 	/*
1106 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1107 	 */
1108 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
1109 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
1110 	__le32	s_journal_dev;		/* device number of journal file */
1111 	__le32	s_last_orphan;		/* start of list of inodes to delete */
1112 	__le32	s_hash_seed[4];		/* HTREE hash seed */
1113 	__u8	s_def_hash_version;	/* Default hash version to use */
1114 	__u8	s_jnl_backup_type;
1115 	__le16  s_desc_size;		/* size of group descriptor */
1116 /*100*/	__le32	s_default_mount_opts;
1117 	__le32	s_first_meta_bg;	/* First metablock block group */
1118 	__le32	s_mkfs_time;		/* When the filesystem was created */
1119 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
1120 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1121 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
1122 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
1123 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
1124 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
1125 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
1126 	__le32	s_flags;		/* Miscellaneous flags */
1127 	__le16  s_raid_stride;		/* RAID stride */
1128 	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1129 	__le64  s_mmp_block;            /* Block for multi-mount protection */
1130 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1131 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
1132 	__u8	s_checksum_type;	/* metadata checksum algorithm used */
1133 	__le16  s_reserved_pad;
1134 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1135 	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
1136 	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
1137 	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
1138 					      snapshot's future use */
1139 	__le32	s_snapshot_list;	/* inode number of the head of the
1140 					   on-disk snapshot list */
1141 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1142 	__le32	s_error_count;		/* number of fs errors */
1143 	__le32	s_first_error_time;	/* first time an error happened */
1144 	__le32	s_first_error_ino;	/* inode involved in first error */
1145 	__le64	s_first_error_block;	/* block involved of first error */
1146 	__u8	s_first_error_func[32];	/* function where the error happened */
1147 	__le32	s_first_error_line;	/* line number where error happened */
1148 	__le32	s_last_error_time;	/* most recent time of an error */
1149 	__le32	s_last_error_ino;	/* inode involved in last error */
1150 	__le32	s_last_error_line;	/* line number where error happened */
1151 	__le64	s_last_error_block;	/* block involved of last error */
1152 	__u8	s_last_error_func[32];	/* function where the error happened */
1153 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1154 	__u8	s_mount_opts[64];
1155 	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
1156 	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
1157 	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
1158 	__le32	s_reserved[108];	/* Padding to the end of the block */
1159 	__le32	s_checksum;		/* crc32c(superblock) */
1160 };
1161 
1162 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1163 
1164 #ifdef __KERNEL__
1165 
1166 /*
1167  * run-time mount flags
1168  */
1169 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
1170 #define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
1171 
1172 /*
1173  * fourth extended-fs super-block data in memory
1174  */
1175 struct ext4_sb_info {
1176 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
1177 	unsigned long s_inodes_per_block;/* Number of inodes per block */
1178 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
1179 	unsigned long s_clusters_per_group; /* Number of clusters in a group */
1180 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
1181 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
1182 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
1183 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
1184 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1185 	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1186 	unsigned long s_overhead;  /* # of fs overhead clusters */
1187 	unsigned int s_cluster_ratio;	/* Number of blocks per cluster */
1188 	unsigned int s_cluster_bits;	/* log2 of s_cluster_ratio */
1189 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
1190 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
1191 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
1192 	struct buffer_head **s_group_desc;
1193 	unsigned int s_mount_opt;
1194 	unsigned int s_mount_opt2;
1195 	unsigned int s_mount_flags;
1196 	unsigned int s_def_mount_opt;
1197 	ext4_fsblk_t s_sb_block;
1198 	kuid_t s_resuid;
1199 	kgid_t s_resgid;
1200 	unsigned short s_mount_state;
1201 	unsigned short s_pad;
1202 	int s_addr_per_block_bits;
1203 	int s_desc_per_block_bits;
1204 	int s_inode_size;
1205 	int s_first_ino;
1206 	unsigned int s_inode_readahead_blks;
1207 	unsigned int s_inode_goal;
1208 	spinlock_t s_next_gen_lock;
1209 	u32 s_next_generation;
1210 	u32 s_hash_seed[4];
1211 	int s_def_hash_version;
1212 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
1213 	struct percpu_counter s_freeclusters_counter;
1214 	struct percpu_counter s_freeinodes_counter;
1215 	struct percpu_counter s_dirs_counter;
1216 	struct percpu_counter s_dirtyclusters_counter;
1217 	struct blockgroup_lock *s_blockgroup_lock;
1218 	struct proc_dir_entry *s_proc;
1219 	struct kobject s_kobj;
1220 	struct completion s_kobj_unregister;
1221 	struct super_block *s_sb;
1222 
1223 	/* Journaling */
1224 	struct journal_s *s_journal;
1225 	struct list_head s_orphan;
1226 	struct mutex s_orphan_lock;
1227 	unsigned long s_resize_flags;		/* Flags indicating if there
1228 						   is a resizer */
1229 	unsigned long s_commit_interval;
1230 	u32 s_max_batch_time;
1231 	u32 s_min_batch_time;
1232 	struct block_device *journal_bdev;
1233 #ifdef CONFIG_QUOTA
1234 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
1235 	int s_jquota_fmt;			/* Format of quota to use */
1236 #endif
1237 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1238 	struct rb_root system_blks;
1239 
1240 #ifdef EXTENTS_STATS
1241 	/* ext4 extents stats */
1242 	unsigned long s_ext_min;
1243 	unsigned long s_ext_max;
1244 	unsigned long s_depth_max;
1245 	spinlock_t s_ext_stats_lock;
1246 	unsigned long s_ext_blocks;
1247 	unsigned long s_ext_extents;
1248 #endif
1249 
1250 	/* for buddy allocator */
1251 	struct ext4_group_info ***s_group_info;
1252 	struct inode *s_buddy_cache;
1253 	spinlock_t s_md_lock;
1254 	unsigned short *s_mb_offsets;
1255 	unsigned int *s_mb_maxs;
1256 	unsigned int s_group_info_size;
1257 
1258 	/* tunables */
1259 	unsigned long s_stripe;
1260 	unsigned int s_mb_stream_request;
1261 	unsigned int s_mb_max_to_scan;
1262 	unsigned int s_mb_min_to_scan;
1263 	unsigned int s_mb_stats;
1264 	unsigned int s_mb_order2_reqs;
1265 	unsigned int s_mb_group_prealloc;
1266 	unsigned int s_max_writeback_mb_bump;
1267 	unsigned int s_max_dir_size_kb;
1268 	/* where last allocation was done - for stream allocation */
1269 	unsigned long s_mb_last_group;
1270 	unsigned long s_mb_last_start;
1271 
1272 	/* stats for buddy allocator */
1273 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
1274 	atomic_t s_bal_success;	/* we found long enough chunks */
1275 	atomic_t s_bal_allocated;	/* in blocks */
1276 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
1277 	atomic_t s_bal_goals;	/* goal hits */
1278 	atomic_t s_bal_breaks;	/* too long searches */
1279 	atomic_t s_bal_2orders;	/* 2^order hits */
1280 	spinlock_t s_bal_lock;
1281 	unsigned long s_mb_buddies_generated;
1282 	unsigned long long s_mb_generation_time;
1283 	atomic_t s_mb_lost_chunks;
1284 	atomic_t s_mb_preallocated;
1285 	atomic_t s_mb_discarded;
1286 	atomic_t s_lock_busy;
1287 
1288 	/* locality groups */
1289 	struct ext4_locality_group __percpu *s_locality_groups;
1290 
1291 	/* for write statistics */
1292 	unsigned long s_sectors_written_start;
1293 	u64 s_kbytes_written;
1294 
1295 	/* the size of zero-out chunk */
1296 	unsigned int s_extent_max_zeroout_kb;
1297 
1298 	unsigned int s_log_groups_per_flex;
1299 	struct flex_groups *s_flex_groups;
1300 	ext4_group_t s_flex_groups_allocated;
1301 
1302 	/* workqueue for dio unwritten */
1303 	struct workqueue_struct *dio_unwritten_wq;
1304 
1305 	/* timer for periodic error stats printing */
1306 	struct timer_list s_err_report;
1307 
1308 	/* Lazy inode table initialization info */
1309 	struct ext4_li_request *s_li_request;
1310 	/* Wait multiplier for lazy initialization thread */
1311 	unsigned int s_li_wait_mult;
1312 
1313 	/* Kernel thread for multiple mount protection */
1314 	struct task_struct *s_mmp_tsk;
1315 
1316 	/* record the last minlen when FITRIM is called. */
1317 	atomic_t s_last_trim_minblks;
1318 
1319 	/* Reference to checksum algorithm driver via cryptoapi */
1320 	struct crypto_shash *s_chksum_driver;
1321 
1322 	/* Precomputed FS UUID checksum for seeding other checksums */
1323 	__u32 s_csum_seed;
1324 };
1325 
1326 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1327 {
1328 	return sb->s_fs_info;
1329 }
1330 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1331 {
1332 	return container_of(inode, struct ext4_inode_info, vfs_inode);
1333 }
1334 
1335 static inline struct timespec ext4_current_time(struct inode *inode)
1336 {
1337 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1338 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1339 }
1340 
1341 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1342 {
1343 	return ino == EXT4_ROOT_INO ||
1344 		ino == EXT4_USR_QUOTA_INO ||
1345 		ino == EXT4_GRP_QUOTA_INO ||
1346 		ino == EXT4_JOURNAL_INO ||
1347 		ino == EXT4_RESIZE_INO ||
1348 		(ino >= EXT4_FIRST_INO(sb) &&
1349 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1350 }
1351 
1352 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1353 					      struct ext4_io_end *io_end)
1354 {
1355 	if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1356 		io_end->flag |= EXT4_IO_END_UNWRITTEN;
1357 		atomic_inc(&EXT4_I(inode)->i_unwritten);
1358 	}
1359 }
1360 
1361 static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode)
1362 {
1363 	return inode->i_private;
1364 }
1365 
1366 static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io)
1367 {
1368 	inode->i_private = io;
1369 }
1370 
1371 /*
1372  * Inode dynamic state flags
1373  */
1374 enum {
1375 	EXT4_STATE_JDATA,		/* journaled data exists */
1376 	EXT4_STATE_NEW,			/* inode is newly created */
1377 	EXT4_STATE_XATTR,		/* has in-inode xattrs */
1378 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
1379 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
1380 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
1381 	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1382 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1383 	EXT4_STATE_DELALLOC_RESERVED,	/* blks already reserved for delalloc */
1384 	EXT4_STATE_DIOREAD_LOCK,	/* Disable support for dio read
1385 					   nolocking */
1386 	EXT4_STATE_MAY_INLINE_DATA,	/* may have in-inode data */
1387 };
1388 
1389 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
1390 static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
1391 {									\
1392 	return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);	\
1393 }									\
1394 static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
1395 {									\
1396 	set_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1397 }									\
1398 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1399 {									\
1400 	clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);		\
1401 }
1402 
1403 EXT4_INODE_BIT_FNS(flag, flags, 0)
1404 #if (BITS_PER_LONG < 64)
1405 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1406 
1407 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1408 {
1409 	(ei)->i_state_flags = 0;
1410 }
1411 #else
1412 EXT4_INODE_BIT_FNS(state, flags, 32)
1413 
1414 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1415 {
1416 	/* We depend on the fact that callers will set i_flags */
1417 }
1418 #endif
1419 #else
1420 /* Assume that user mode programs are passing in an ext4fs superblock, not
1421  * a kernel struct super_block.  This will allow us to call the feature-test
1422  * macros from user land. */
1423 #define EXT4_SB(sb)	(sb)
1424 #endif
1425 
1426 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1427 
1428 /*
1429  * Codes for operating systems
1430  */
1431 #define EXT4_OS_LINUX		0
1432 #define EXT4_OS_HURD		1
1433 #define EXT4_OS_MASIX		2
1434 #define EXT4_OS_FREEBSD		3
1435 #define EXT4_OS_LITES		4
1436 
1437 /*
1438  * Revision levels
1439  */
1440 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1441 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1442 
1443 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1444 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1445 
1446 #define EXT4_GOOD_OLD_INODE_SIZE 128
1447 
1448 /*
1449  * Feature set definitions
1450  */
1451 
1452 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1453 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1454 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1455 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1456 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1457 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1458 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1459 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1460 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1461 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1462 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1463 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1464 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1465 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1466 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1467 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1468 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1469 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1470 
1471 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1472 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1473 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1474 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1475 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1476 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1477 
1478 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1479 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1480 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1481 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1482 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1483 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1484 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1485 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
1486 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
1487 /*
1488  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1489  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1490  * all other data structures' checksums.  However, the METADATA_CSUM and
1491  * GDT_CSUM bits are mutually exclusive.
1492  */
1493 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
1494 
1495 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1496 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1497 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1498 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1499 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1500 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1501 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1502 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1503 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1504 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
1505 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1506 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM	0x2000 /* use crc32c for bg */
1507 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
1508 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA	0x8000 /* data in inode */
1509 
1510 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1511 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1512 					 EXT4_FEATURE_INCOMPAT_META_BG)
1513 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1514 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1515 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1516 
1517 #define EXT3_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
1518 #define EXT3_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1519 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1520 					 EXT4_FEATURE_INCOMPAT_META_BG)
1521 #define EXT3_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1522 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1523 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1524 
1525 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1526 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1527 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1528 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1529 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1530 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1531 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1532 					 EXT4_FEATURE_INCOMPAT_MMP)
1533 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1534 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1535 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1536 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1537 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1538 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1539 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1540 					 EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1541 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1542 					 EXT4_FEATURE_RO_COMPAT_QUOTA)
1543 
1544 /*
1545  * Default values for user and/or group using reserved blocks
1546  */
1547 #define	EXT4_DEF_RESUID		0
1548 #define	EXT4_DEF_RESGID		0
1549 
1550 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1551 
1552 /*
1553  * Default mount options
1554  */
1555 #define EXT4_DEFM_DEBUG		0x0001
1556 #define EXT4_DEFM_BSDGROUPS	0x0002
1557 #define EXT4_DEFM_XATTR_USER	0x0004
1558 #define EXT4_DEFM_ACL		0x0008
1559 #define EXT4_DEFM_UID16		0x0010
1560 #define EXT4_DEFM_JMODE		0x0060
1561 #define EXT4_DEFM_JMODE_DATA	0x0020
1562 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1563 #define EXT4_DEFM_JMODE_WBACK	0x0060
1564 #define EXT4_DEFM_NOBARRIER	0x0100
1565 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1566 #define EXT4_DEFM_DISCARD	0x0400
1567 #define EXT4_DEFM_NODELALLOC	0x0800
1568 
1569 /*
1570  * Default journal batch times
1571  */
1572 #define EXT4_DEF_MIN_BATCH_TIME	0
1573 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1574 
1575 /*
1576  * Minimum number of groups in a flexgroup before we separate out
1577  * directories into the first block group of a flexgroup
1578  */
1579 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1580 
1581 /*
1582  * Structure of a directory entry
1583  */
1584 #define EXT4_NAME_LEN 255
1585 
1586 struct ext4_dir_entry {
1587 	__le32	inode;			/* Inode number */
1588 	__le16	rec_len;		/* Directory entry length */
1589 	__le16	name_len;		/* Name length */
1590 	char	name[EXT4_NAME_LEN];	/* File name */
1591 };
1592 
1593 /*
1594  * The new version of the directory entry.  Since EXT4 structures are
1595  * stored in intel byte order, and the name_len field could never be
1596  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1597  * file_type field.
1598  */
1599 struct ext4_dir_entry_2 {
1600 	__le32	inode;			/* Inode number */
1601 	__le16	rec_len;		/* Directory entry length */
1602 	__u8	name_len;		/* Name length */
1603 	__u8	file_type;
1604 	char	name[EXT4_NAME_LEN];	/* File name */
1605 };
1606 
1607 /*
1608  * This is a bogus directory entry at the end of each leaf block that
1609  * records checksums.
1610  */
1611 struct ext4_dir_entry_tail {
1612 	__le32	det_reserved_zero1;	/* Pretend to be unused */
1613 	__le16	det_rec_len;		/* 12 */
1614 	__u8	det_reserved_zero2;	/* Zero name length */
1615 	__u8	det_reserved_ft;	/* 0xDE, fake file type */
1616 	__le32	det_checksum;		/* crc32c(uuid+inum+dirblock) */
1617 };
1618 
1619 /*
1620  * Ext4 directory file types.  Only the low 3 bits are used.  The
1621  * other bits are reserved for now.
1622  */
1623 #define EXT4_FT_UNKNOWN		0
1624 #define EXT4_FT_REG_FILE	1
1625 #define EXT4_FT_DIR		2
1626 #define EXT4_FT_CHRDEV		3
1627 #define EXT4_FT_BLKDEV		4
1628 #define EXT4_FT_FIFO		5
1629 #define EXT4_FT_SOCK		6
1630 #define EXT4_FT_SYMLINK		7
1631 
1632 #define EXT4_FT_MAX		8
1633 
1634 #define EXT4_FT_DIR_CSUM	0xDE
1635 
1636 /*
1637  * EXT4_DIR_PAD defines the directory entries boundaries
1638  *
1639  * NOTE: It must be a multiple of 4
1640  */
1641 #define EXT4_DIR_PAD			4
1642 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1643 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1644 					 ~EXT4_DIR_ROUND)
1645 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1646 
1647 /*
1648  * If we ever get support for fs block sizes > page_size, we'll need
1649  * to remove the #if statements in the next two functions...
1650  */
1651 static inline unsigned int
1652 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1653 {
1654 	unsigned len = le16_to_cpu(dlen);
1655 
1656 #if (PAGE_CACHE_SIZE >= 65536)
1657 	if (len == EXT4_MAX_REC_LEN || len == 0)
1658 		return blocksize;
1659 	return (len & 65532) | ((len & 3) << 16);
1660 #else
1661 	return len;
1662 #endif
1663 }
1664 
1665 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1666 {
1667 	if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1668 		BUG();
1669 #if (PAGE_CACHE_SIZE >= 65536)
1670 	if (len < 65536)
1671 		return cpu_to_le16(len);
1672 	if (len == blocksize) {
1673 		if (blocksize == 65536)
1674 			return cpu_to_le16(EXT4_MAX_REC_LEN);
1675 		else
1676 			return cpu_to_le16(0);
1677 	}
1678 	return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1679 #else
1680 	return cpu_to_le16(len);
1681 #endif
1682 }
1683 
1684 /*
1685  * Hash Tree Directory indexing
1686  * (c) Daniel Phillips, 2001
1687  */
1688 
1689 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1690 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1691 		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1692 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1693 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1694 
1695 /* Legal values for the dx_root hash_version field: */
1696 
1697 #define DX_HASH_LEGACY		0
1698 #define DX_HASH_HALF_MD4	1
1699 #define DX_HASH_TEA		2
1700 #define DX_HASH_LEGACY_UNSIGNED	3
1701 #define DX_HASH_HALF_MD4_UNSIGNED	4
1702 #define DX_HASH_TEA_UNSIGNED		5
1703 
1704 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1705 			      const void *address, unsigned int length)
1706 {
1707 	struct {
1708 		struct shash_desc shash;
1709 		char ctx[4];
1710 	} desc;
1711 	int err;
1712 
1713 	BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
1714 
1715 	desc.shash.tfm = sbi->s_chksum_driver;
1716 	desc.shash.flags = 0;
1717 	*(u32 *)desc.ctx = crc;
1718 
1719 	err = crypto_shash_update(&desc.shash, address, length);
1720 	BUG_ON(err);
1721 
1722 	return *(u32 *)desc.ctx;
1723 }
1724 
1725 #ifdef __KERNEL__
1726 
1727 /* hash info structure used by the directory hash */
1728 struct dx_hash_info
1729 {
1730 	u32		hash;
1731 	u32		minor_hash;
1732 	int		hash_version;
1733 	u32		*seed;
1734 };
1735 
1736 
1737 /* 32 and 64 bit signed EOF for dx directories */
1738 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
1739 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
1740 
1741 
1742 /*
1743  * Control parameters used by ext4_htree_next_block
1744  */
1745 #define HASH_NB_ALWAYS		1
1746 
1747 
1748 /*
1749  * Describe an inode's exact location on disk and in memory
1750  */
1751 struct ext4_iloc
1752 {
1753 	struct buffer_head *bh;
1754 	unsigned long offset;
1755 	ext4_group_t block_group;
1756 };
1757 
1758 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1759 {
1760 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1761 }
1762 
1763 /*
1764  * This structure is stuffed into the struct file's private_data field
1765  * for directories.  It is where we put information so that we can do
1766  * readdir operations in hash tree order.
1767  */
1768 struct dir_private_info {
1769 	struct rb_root	root;
1770 	struct rb_node	*curr_node;
1771 	struct fname	*extra_fname;
1772 	loff_t		last_pos;
1773 	__u32		curr_hash;
1774 	__u32		curr_minor_hash;
1775 	__u32		next_hash;
1776 };
1777 
1778 /* calculate the first block number of the group */
1779 static inline ext4_fsblk_t
1780 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1781 {
1782 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1783 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1784 }
1785 
1786 /*
1787  * Special error return code only used by dx_probe() and its callers.
1788  */
1789 #define ERR_BAD_DX_DIR	-75000
1790 
1791 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1792 			ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1793 
1794 /*
1795  * Timeout and state flag for lazy initialization inode thread.
1796  */
1797 #define EXT4_DEF_LI_WAIT_MULT			10
1798 #define EXT4_DEF_LI_MAX_START_DELAY		5
1799 #define EXT4_LAZYINIT_QUIT			0x0001
1800 #define EXT4_LAZYINIT_RUNNING			0x0002
1801 
1802 /*
1803  * Lazy inode table initialization info
1804  */
1805 struct ext4_lazy_init {
1806 	unsigned long		li_state;
1807 	struct list_head	li_request_list;
1808 	struct mutex		li_list_mtx;
1809 };
1810 
1811 struct ext4_li_request {
1812 	struct super_block	*lr_super;
1813 	struct ext4_sb_info	*lr_sbi;
1814 	ext4_group_t		lr_next_group;
1815 	struct list_head	lr_request;
1816 	unsigned long		lr_next_sched;
1817 	unsigned long		lr_timeout;
1818 };
1819 
1820 struct ext4_features {
1821 	struct kobject f_kobj;
1822 	struct completion f_kobj_unregister;
1823 };
1824 
1825 /*
1826  * This structure will be used for multiple mount protection. It will be
1827  * written into the block number saved in the s_mmp_block field in the
1828  * superblock. Programs that check MMP should assume that if
1829  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1830  * to use the filesystem, regardless of how old the timestamp is.
1831  */
1832 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1833 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1834 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1835 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1836 
1837 struct mmp_struct {
1838 	__le32	mmp_magic;		/* Magic number for MMP */
1839 	__le32	mmp_seq;		/* Sequence no. updated periodically */
1840 
1841 	/*
1842 	 * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1843 	 * purposes and do not affect the correctness of the algorithm
1844 	 */
1845 	__le64	mmp_time;		/* Time last updated */
1846 	char	mmp_nodename[64];	/* Node which last updated MMP block */
1847 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
1848 
1849 	/*
1850 	 * mmp_check_interval is used to verify if the MMP block has been
1851 	 * updated on the block device. The value is updated based on the
1852 	 * maximum time to write the MMP block during an update cycle.
1853 	 */
1854 	__le16	mmp_check_interval;
1855 
1856 	__le16	mmp_pad1;
1857 	__le32	mmp_pad2[226];
1858 	__le32	mmp_checksum;		/* crc32c(uuid+mmp_block) */
1859 };
1860 
1861 /* arguments passed to the mmp thread */
1862 struct mmpd_data {
1863 	struct buffer_head *bh; /* bh from initial read_mmp_block() */
1864 	struct super_block *sb;  /* super block of the fs */
1865 };
1866 
1867 /*
1868  * Check interval multiplier
1869  * The MMP block is written every update interval and initially checked every
1870  * update interval x the multiplier (the value is then adapted based on the
1871  * write latency). The reason is that writes can be delayed under load and we
1872  * don't want readers to incorrectly assume that the filesystem is no longer
1873  * in use.
1874  */
1875 #define EXT4_MMP_CHECK_MULT		2UL
1876 
1877 /*
1878  * Minimum interval for MMP checking in seconds.
1879  */
1880 #define EXT4_MMP_MIN_CHECK_INTERVAL	5UL
1881 
1882 /*
1883  * Maximum interval for MMP checking in seconds.
1884  */
1885 #define EXT4_MMP_MAX_CHECK_INTERVAL	300UL
1886 
1887 /*
1888  * Function prototypes
1889  */
1890 
1891 /*
1892  * Ok, these declarations are also in <linux/kernel.h> but none of the
1893  * ext4 source programs needs to include it so they are duplicated here.
1894  */
1895 # define NORET_TYPE	/**/
1896 # define ATTRIB_NORET	__attribute__((noreturn))
1897 # define NORET_AND	noreturn,
1898 
1899 /* bitmap.c */
1900 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
1901 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1902 				struct ext4_group_desc *gdp,
1903 				struct buffer_head *bh, int sz);
1904 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1905 				  struct ext4_group_desc *gdp,
1906 				  struct buffer_head *bh, int sz);
1907 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1908 				struct ext4_group_desc *gdp,
1909 				struct buffer_head *bh);
1910 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1911 				  struct ext4_group_desc *gdp,
1912 				  struct buffer_head *bh);
1913 
1914 /* balloc.c */
1915 extern void ext4_validate_block_bitmap(struct super_block *sb,
1916 				       struct ext4_group_desc *desc,
1917 				       unsigned int block_group,
1918 				       struct buffer_head *bh);
1919 extern unsigned int ext4_block_group(struct super_block *sb,
1920 			ext4_fsblk_t blocknr);
1921 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1922 			ext4_fsblk_t blocknr);
1923 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1924 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1925 			ext4_group_t group);
1926 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1927 					 ext4_fsblk_t goal,
1928 					 unsigned int flags,
1929 					 unsigned long *count,
1930 					 int *errp);
1931 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1932 				    s64 nclusters, unsigned int flags);
1933 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1934 extern void ext4_check_blocks_bitmap(struct super_block *);
1935 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1936 						    ext4_group_t block_group,
1937 						    struct buffer_head ** bh);
1938 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1939 
1940 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1941 						ext4_group_t block_group);
1942 extern int ext4_wait_block_bitmap(struct super_block *sb,
1943 				  ext4_group_t block_group,
1944 				  struct buffer_head *bh);
1945 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1946 						  ext4_group_t block_group);
1947 extern void ext4_init_block_bitmap(struct super_block *sb,
1948 				   struct buffer_head *bh,
1949 				   ext4_group_t group,
1950 				   struct ext4_group_desc *desc);
1951 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1952 					      ext4_group_t block_group,
1953 					      struct ext4_group_desc *gdp);
1954 extern unsigned ext4_num_overhead_clusters(struct super_block *sb,
1955 					   ext4_group_t block_group,
1956 					   struct ext4_group_desc *gdp);
1957 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1958 
1959 /* dir.c */
1960 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1961 				  struct file *,
1962 				  struct ext4_dir_entry_2 *,
1963 				  struct buffer_head *, unsigned int);
1964 #define ext4_check_dir_entry(dir, filp, de, bh, offset)			\
1965 	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1966 					(de), (bh), (offset)))
1967 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1968 				    __u32 minor_hash,
1969 				    struct ext4_dir_entry_2 *dirent);
1970 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1971 
1972 /* fsync.c */
1973 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
1974 extern int ext4_flush_unwritten_io(struct inode *);
1975 
1976 /* hash.c */
1977 extern int ext4fs_dirhash(const char *name, int len, struct
1978 			  dx_hash_info *hinfo);
1979 
1980 /* ialloc.c */
1981 extern struct inode *ext4_new_inode(handle_t *, struct inode *, umode_t,
1982 				    const struct qstr *qstr, __u32 goal,
1983 				    uid_t *owner);
1984 extern void ext4_free_inode(handle_t *, struct inode *);
1985 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1986 extern unsigned long ext4_count_free_inodes(struct super_block *);
1987 extern unsigned long ext4_count_dirs(struct super_block *);
1988 extern void ext4_check_inodes_bitmap(struct super_block *);
1989 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1990 extern int ext4_init_inode_table(struct super_block *sb,
1991 				 ext4_group_t group, int barrier);
1992 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
1993 
1994 /* mballoc.c */
1995 extern long ext4_mb_stats;
1996 extern long ext4_mb_max_to_scan;
1997 extern int ext4_mb_init(struct super_block *);
1998 extern int ext4_mb_release(struct super_block *);
1999 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2000 				struct ext4_allocation_request *, int *);
2001 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2002 extern void ext4_discard_preallocations(struct inode *);
2003 extern int __init ext4_init_mballoc(void);
2004 extern void ext4_exit_mballoc(void);
2005 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2006 			     struct buffer_head *bh, ext4_fsblk_t block,
2007 			     unsigned long count, int flags);
2008 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2009 				   ext4_group_t ngroups);
2010 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2011 		ext4_group_t i, struct ext4_group_desc *desc);
2012 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2013 				ext4_fsblk_t block, unsigned long count);
2014 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2015 
2016 /* inode.c */
2017 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
2018 						ext4_lblk_t, int, int *);
2019 struct buffer_head *ext4_bread(handle_t *, struct inode *,
2020 						ext4_lblk_t, int, int *);
2021 int ext4_get_block_write(struct inode *inode, sector_t iblock,
2022 			 struct buffer_head *bh_result, int create);
2023 int ext4_get_block(struct inode *inode, sector_t iblock,
2024 				struct buffer_head *bh_result, int create);
2025 int ext4_walk_page_buffers(handle_t *handle,
2026 			   struct buffer_head *head,
2027 			   unsigned from,
2028 			   unsigned to,
2029 			   int *partial,
2030 			   int (*fn)(handle_t *handle,
2031 				     struct buffer_head *bh));
2032 int do_journal_get_write_access(handle_t *handle,
2033 				struct buffer_head *bh);
2034 
2035 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2036 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2037 extern int  ext4_setattr(struct dentry *, struct iattr *);
2038 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
2039 				struct kstat *stat);
2040 extern void ext4_evict_inode(struct inode *);
2041 extern void ext4_clear_inode(struct inode *);
2042 extern int  ext4_sync_inode(handle_t *, struct inode *);
2043 extern void ext4_dirty_inode(struct inode *, int);
2044 extern int ext4_change_inode_journal_flag(struct inode *, int);
2045 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2046 extern int ext4_can_truncate(struct inode *inode);
2047 extern void ext4_truncate(struct inode *);
2048 extern int ext4_punch_hole(struct file *file, loff_t offset, loff_t length);
2049 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2050 extern void ext4_set_inode_flags(struct inode *);
2051 extern void ext4_get_inode_flags(struct ext4_inode_info *);
2052 extern int ext4_alloc_da_blocks(struct inode *inode);
2053 extern void ext4_set_aops(struct inode *inode);
2054 extern int ext4_writepage_trans_blocks(struct inode *);
2055 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2056 extern int ext4_discard_partial_page_buffers(handle_t *handle,
2057 		struct address_space *mapping, loff_t from,
2058 		loff_t length, int flags);
2059 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2060 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2061 extern void ext4_da_update_reserve_space(struct inode *inode,
2062 					int used, int quota_claim);
2063 
2064 /* indirect.c */
2065 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2066 				struct ext4_map_blocks *map, int flags);
2067 extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
2068 				const struct iovec *iov, loff_t offset,
2069 				unsigned long nr_segs);
2070 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2071 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk);
2072 extern void ext4_ind_truncate(struct inode *inode);
2073 
2074 /* ioctl.c */
2075 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2076 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2077 
2078 /* migrate.c */
2079 extern int ext4_ext_migrate(struct inode *);
2080 
2081 /* namei.c */
2082 extern int ext4_dirent_csum_verify(struct inode *inode,
2083 				   struct ext4_dir_entry *dirent);
2084 extern int ext4_orphan_add(handle_t *, struct inode *);
2085 extern int ext4_orphan_del(handle_t *, struct inode *);
2086 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2087 				__u32 start_minor_hash, __u32 *next_hash);
2088 
2089 /* resize.c */
2090 extern int ext4_group_add(struct super_block *sb,
2091 				struct ext4_new_group_data *input);
2092 extern int ext4_group_extend(struct super_block *sb,
2093 				struct ext4_super_block *es,
2094 				ext4_fsblk_t n_blocks_count);
2095 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2096 
2097 /* super.c */
2098 extern int ext4_calculate_overhead(struct super_block *sb);
2099 extern int ext4_superblock_csum_verify(struct super_block *sb,
2100 				       struct ext4_super_block *es);
2101 extern void ext4_superblock_csum_set(struct super_block *sb);
2102 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2103 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2104 extern void ext4_kvfree(void *ptr);
2105 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2106 				    ext4_group_t ngroup);
2107 extern __printf(4, 5)
2108 void __ext4_error(struct super_block *, const char *, unsigned int,
2109 		  const char *, ...);
2110 #define ext4_error(sb, message...)	__ext4_error(sb, __func__,	\
2111 						     __LINE__, ## message)
2112 extern __printf(5, 6)
2113 void ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2114 		      const char *, ...);
2115 extern __printf(5, 6)
2116 void ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2117 		     const char *, ...);
2118 extern void __ext4_std_error(struct super_block *, const char *,
2119 			     unsigned int, int);
2120 extern __printf(4, 5)
2121 void __ext4_abort(struct super_block *, const char *, unsigned int,
2122 		  const char *, ...);
2123 #define ext4_abort(sb, message...)	__ext4_abort(sb, __func__, \
2124 						       __LINE__, ## message)
2125 extern __printf(4, 5)
2126 void __ext4_warning(struct super_block *, const char *, unsigned int,
2127 		    const char *, ...);
2128 #define ext4_warning(sb, message...)	__ext4_warning(sb, __func__, \
2129 						       __LINE__, ## message)
2130 extern __printf(3, 4)
2131 void ext4_msg(struct super_block *, const char *, const char *, ...);
2132 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2133 			   const char *, unsigned int, const char *);
2134 #define dump_mmp_msg(sb, mmp, msg)	__dump_mmp_msg(sb, mmp, __func__, \
2135 						       __LINE__, msg)
2136 extern __printf(7, 8)
2137 void __ext4_grp_locked_error(const char *, unsigned int,
2138 			     struct super_block *, ext4_group_t,
2139 			     unsigned long, ext4_fsblk_t,
2140 			     const char *, ...);
2141 #define ext4_grp_locked_error(sb, grp, message...) \
2142 	__ext4_grp_locked_error(__func__, __LINE__, (sb), (grp), ## message)
2143 extern void ext4_update_dynamic_rev(struct super_block *sb);
2144 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2145 					__u32 compat);
2146 extern int ext4_update_rocompat_feature(handle_t *handle,
2147 					struct super_block *sb,	__u32 rocompat);
2148 extern int ext4_update_incompat_feature(handle_t *handle,
2149 					struct super_block *sb,	__u32 incompat);
2150 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2151 				      struct ext4_group_desc *bg);
2152 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2153 				      struct ext4_group_desc *bg);
2154 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2155 				     struct ext4_group_desc *bg);
2156 extern __u32 ext4_free_group_clusters(struct super_block *sb,
2157 				      struct ext4_group_desc *bg);
2158 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2159 				 struct ext4_group_desc *bg);
2160 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2161 				struct ext4_group_desc *bg);
2162 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2163 				   struct ext4_group_desc *bg);
2164 extern void ext4_block_bitmap_set(struct super_block *sb,
2165 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2166 extern void ext4_inode_bitmap_set(struct super_block *sb,
2167 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2168 extern void ext4_inode_table_set(struct super_block *sb,
2169 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
2170 extern void ext4_free_group_clusters_set(struct super_block *sb,
2171 					 struct ext4_group_desc *bg,
2172 					 __u32 count);
2173 extern void ext4_free_inodes_set(struct super_block *sb,
2174 				struct ext4_group_desc *bg, __u32 count);
2175 extern void ext4_used_dirs_set(struct super_block *sb,
2176 				struct ext4_group_desc *bg, __u32 count);
2177 extern void ext4_itable_unused_set(struct super_block *sb,
2178 				   struct ext4_group_desc *bg, __u32 count);
2179 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2180 				       struct ext4_group_desc *gdp);
2181 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2182 				     struct ext4_group_desc *gdp);
2183 
2184 static inline int ext4_has_group_desc_csum(struct super_block *sb)
2185 {
2186 	return EXT4_HAS_RO_COMPAT_FEATURE(sb,
2187 					  EXT4_FEATURE_RO_COMPAT_GDT_CSUM |
2188 					  EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
2189 }
2190 
2191 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2192 {
2193 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2194 		le32_to_cpu(es->s_blocks_count_lo);
2195 }
2196 
2197 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2198 {
2199 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2200 		le32_to_cpu(es->s_r_blocks_count_lo);
2201 }
2202 
2203 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2204 {
2205 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2206 		le32_to_cpu(es->s_free_blocks_count_lo);
2207 }
2208 
2209 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2210 					 ext4_fsblk_t blk)
2211 {
2212 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2213 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2214 }
2215 
2216 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2217 					      ext4_fsblk_t blk)
2218 {
2219 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2220 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2221 }
2222 
2223 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2224 					   ext4_fsblk_t blk)
2225 {
2226 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2227 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2228 }
2229 
2230 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2231 {
2232 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2233 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2234 			le32_to_cpu(raw_inode->i_size_lo);
2235 	else
2236 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2237 }
2238 
2239 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2240 {
2241 	raw_inode->i_size_lo = cpu_to_le32(i_size);
2242 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2243 }
2244 
2245 static inline
2246 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2247 					    ext4_group_t group)
2248 {
2249 	 struct ext4_group_info ***grp_info;
2250 	 long indexv, indexh;
2251 	 grp_info = EXT4_SB(sb)->s_group_info;
2252 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2253 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2254 	 return grp_info[indexv][indexh];
2255 }
2256 
2257 /*
2258  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2259  * the locking protocol documented in the comments of ext4_group_add()
2260  * in resize.c
2261  */
2262 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2263 {
2264 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
2265 
2266 	smp_rmb();
2267 	return ngroups;
2268 }
2269 
2270 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2271 					     ext4_group_t block_group)
2272 {
2273 	return block_group >> sbi->s_log_groups_per_flex;
2274 }
2275 
2276 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2277 {
2278 	return 1 << sbi->s_log_groups_per_flex;
2279 }
2280 
2281 #define ext4_std_error(sb, errno)				\
2282 do {								\
2283 	if ((errno))						\
2284 		__ext4_std_error((sb), __func__, __LINE__, (errno));	\
2285 } while (0)
2286 
2287 #ifdef CONFIG_SMP
2288 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2289  * counters. So we need to make sure we have free clusters more
2290  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2291  */
2292 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2293 #else
2294 #define EXT4_FREECLUSTERS_WATERMARK 0
2295 #endif
2296 
2297 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2298 {
2299 	/*
2300 	 * XXX: replace with spinlock if seen contended -bzzz
2301 	 */
2302 	down_write(&EXT4_I(inode)->i_data_sem);
2303 	if (newsize > EXT4_I(inode)->i_disksize)
2304 		EXT4_I(inode)->i_disksize = newsize;
2305 	up_write(&EXT4_I(inode)->i_data_sem);
2306 	return ;
2307 }
2308 
2309 struct ext4_group_info {
2310 	unsigned long   bb_state;
2311 	struct rb_root  bb_free_root;
2312 	ext4_grpblk_t	bb_first_free;	/* first free block */
2313 	ext4_grpblk_t	bb_free;	/* total free blocks */
2314 	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
2315 	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
2316 	struct          list_head bb_prealloc_list;
2317 #ifdef DOUBLE_CHECK
2318 	void            *bb_bitmap;
2319 #endif
2320 	struct rw_semaphore alloc_sem;
2321 	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
2322 					 * regions, index is order.
2323 					 * bb_counters[3] = 5 means
2324 					 * 5 free 8-block regions. */
2325 };
2326 
2327 #define EXT4_GROUP_INFO_NEED_INIT_BIT		0
2328 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT		1
2329 
2330 #define EXT4_MB_GRP_NEED_INIT(grp)	\
2331 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2332 
2333 #define EXT4_MB_GRP_WAS_TRIMMED(grp)	\
2334 	(test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2335 #define EXT4_MB_GRP_SET_TRIMMED(grp)	\
2336 	(set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2337 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)	\
2338 	(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2339 
2340 #define EXT4_MAX_CONTENTION		8
2341 #define EXT4_CONTENTION_THRESHOLD	2
2342 
2343 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2344 					      ext4_group_t group)
2345 {
2346 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2347 }
2348 
2349 /*
2350  * Returns true if the filesystem is busy enough that attempts to
2351  * access the block group locks has run into contention.
2352  */
2353 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2354 {
2355 	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2356 }
2357 
2358 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2359 {
2360 	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2361 	if (spin_trylock(lock))
2362 		/*
2363 		 * We're able to grab the lock right away, so drop the
2364 		 * lock contention counter.
2365 		 */
2366 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2367 	else {
2368 		/*
2369 		 * The lock is busy, so bump the contention counter,
2370 		 * and then wait on the spin lock.
2371 		 */
2372 		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2373 				  EXT4_MAX_CONTENTION);
2374 		spin_lock(lock);
2375 	}
2376 }
2377 
2378 static inline void ext4_unlock_group(struct super_block *sb,
2379 					ext4_group_t group)
2380 {
2381 	spin_unlock(ext4_group_lock_ptr(sb, group));
2382 }
2383 
2384 /*
2385  * Block validity checking
2386  */
2387 #define ext4_check_indirect_blockref(inode, bh)				\
2388 	ext4_check_blockref(__func__, __LINE__, inode,			\
2389 			    (__le32 *)(bh)->b_data,			\
2390 			    EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2391 
2392 #define ext4_ind_check_inode(inode)					\
2393 	ext4_check_blockref(__func__, __LINE__, inode,			\
2394 			    EXT4_I(inode)->i_data,			\
2395 			    EXT4_NDIR_BLOCKS)
2396 
2397 /*
2398  * Inodes and files operations
2399  */
2400 
2401 /* dir.c */
2402 extern const struct file_operations ext4_dir_operations;
2403 
2404 /* file.c */
2405 extern const struct inode_operations ext4_file_inode_operations;
2406 extern const struct file_operations ext4_file_operations;
2407 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2408 extern void ext4_unwritten_wait(struct inode *inode);
2409 
2410 /* namei.c */
2411 extern const struct inode_operations ext4_dir_inode_operations;
2412 extern const struct inode_operations ext4_special_inode_operations;
2413 extern struct dentry *ext4_get_parent(struct dentry *child);
2414 
2415 /* symlink.c */
2416 extern const struct inode_operations ext4_symlink_inode_operations;
2417 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2418 
2419 /* block_validity */
2420 extern void ext4_release_system_zone(struct super_block *sb);
2421 extern int ext4_setup_system_zone(struct super_block *sb);
2422 extern int __init ext4_init_system_zone(void);
2423 extern void ext4_exit_system_zone(void);
2424 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2425 				 ext4_fsblk_t start_blk,
2426 				 unsigned int count);
2427 extern int ext4_check_blockref(const char *, unsigned int,
2428 			       struct inode *, __le32 *, unsigned int);
2429 
2430 /* extents.c */
2431 struct ext4_ext_path;
2432 struct ext4_extent;
2433 
2434 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2435 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2436 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
2437 				       int chunk);
2438 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2439 			       struct ext4_map_blocks *map, int flags);
2440 extern void ext4_ext_truncate(struct inode *);
2441 extern int ext4_ext_punch_hole(struct file *file, loff_t offset,
2442 				loff_t length);
2443 extern void ext4_ext_init(struct super_block *);
2444 extern void ext4_ext_release(struct super_block *);
2445 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2446 			  loff_t len);
2447 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
2448 			  ssize_t len);
2449 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2450 			   struct ext4_map_blocks *map, int flags);
2451 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
2452 					 ext4_lblk_t lblocks);
2453 extern int ext4_extent_tree_init(handle_t *, struct inode *);
2454 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
2455 						   int num,
2456 						   struct ext4_ext_path *path);
2457 extern int ext4_can_extents_be_merged(struct inode *inode,
2458 				      struct ext4_extent *ex1,
2459 				      struct ext4_extent *ex2);
2460 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
2461 				  struct ext4_ext_path *,
2462 				  struct ext4_extent *, int);
2463 extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
2464 						  struct ext4_ext_path *);
2465 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
2466 extern int ext4_ext_check_inode(struct inode *inode);
2467 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
2468 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2469 			__u64 start, __u64 len);
2470 
2471 
2472 /* move_extent.c */
2473 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2474 			     __u64 start_orig, __u64 start_donor,
2475 			     __u64 len, __u64 *moved_len);
2476 
2477 /* page-io.c */
2478 extern int __init ext4_init_pageio(void);
2479 extern void ext4_add_complete_io(ext4_io_end_t *io_end);
2480 extern void ext4_exit_pageio(void);
2481 extern void ext4_ioend_wait(struct inode *);
2482 extern void ext4_free_io_end(ext4_io_end_t *io);
2483 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2484 extern void ext4_io_submit(struct ext4_io_submit *io);
2485 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2486 			       struct page *page,
2487 			       int len,
2488 			       struct writeback_control *wbc);
2489 
2490 /* mmp.c */
2491 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2492 extern void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp);
2493 extern int ext4_mmp_csum_verify(struct super_block *sb,
2494 				struct mmp_struct *mmp);
2495 
2496 /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
2497 enum ext4_state_bits {
2498 	BH_Uninit	/* blocks are allocated but uninitialized on disk */
2499 	  = BH_JBDPrivateStart,
2500 	BH_AllocFromCluster,	/* allocated blocks were part of already
2501 				 * allocated cluster. Note that this flag will
2502 				 * never, ever appear in a buffer_head's state
2503 				 * flag. See EXT4_MAP_FROM_CLUSTER to see where
2504 				 * this is used. */
2505 };
2506 
2507 BUFFER_FNS(Uninit, uninit)
2508 TAS_BUFFER_FNS(Uninit, uninit)
2509 
2510 /*
2511  * Add new method to test wether block and inode bitmaps are properly
2512  * initialized. With uninit_bg reading the block from disk is not enough
2513  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2514  */
2515 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2516 
2517 static inline int bitmap_uptodate(struct buffer_head *bh)
2518 {
2519 	return (buffer_uptodate(bh) &&
2520 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2521 }
2522 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2523 {
2524 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2525 }
2526 
2527 /*
2528  * Disable DIO read nolock optimization, so new dioreaders will be forced
2529  * to grab i_mutex
2530  */
2531 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
2532 {
2533 	ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2534 	smp_mb();
2535 }
2536 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
2537 {
2538 	smp_mb();
2539 	ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2540 }
2541 
2542 #define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)
2543 
2544 /* For ioend & aio unwritten conversion wait queues */
2545 #define EXT4_WQ_HASH_SZ		37
2546 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2547 					    EXT4_WQ_HASH_SZ])
2548 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2549 					     EXT4_WQ_HASH_SZ])
2550 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2551 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2552 
2553 #define EXT4_RESIZING	0
2554 extern int ext4_resize_begin(struct super_block *sb);
2555 extern void ext4_resize_end(struct super_block *sb);
2556 
2557 #endif	/* __KERNEL__ */
2558 
2559 #endif	/* _EXT4_H */
2560