aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/f2fs_fs.h
blob: 28473899602817afd35ebe544c432a8d6044987b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
// SPDX-License-Identifier: GPL-2.0
/**
 * include/linux/f2fs_fs.h
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *             http://www.samsung.com/
 */
#ifndef _LINUX_F2FS_FS_H
#define _LINUX_F2FS_FS_H

#include <linux/pagemap.h>
#include <linux/types.h>

#define F2FS_SUPER_OFFSET		1024	/* byte-size offset */
#define F2FS_MIN_LOG_SECTOR_SIZE	9	/* 9 bits for 512 bytes */
#define F2FS_MAX_LOG_SECTOR_SIZE	12	/* 12 bits for 4096 bytes */
#define F2FS_LOG_SECTORS_PER_BLOCK	3	/* log number for sector/blk */
#define F2FS_BLKSIZE			4096	/* support only 4KB block */
#define F2FS_BLKSIZE_BITS		12	/* bits for F2FS_BLKSIZE */
#define F2FS_MAX_EXTENSION		64	/* # of extension entries */
#define F2FS_EXTENSION_LEN		8	/* max size of extension */
#define F2FS_BLK_ALIGN(x)	(((x) + F2FS_BLKSIZE - 1) >> F2FS_BLKSIZE_BITS)

#define NULL_ADDR		((block_t)0)	/* used as block_t addresses */
#define NEW_ADDR		((block_t)-1)	/* used as block_t addresses */

#define F2FS_BYTES_TO_BLK(bytes)	((bytes) >> F2FS_BLKSIZE_BITS)
#define F2FS_BLK_TO_BYTES(blk)		((blk) << F2FS_BLKSIZE_BITS)

/* 0, 1(node nid), 2(meta nid) are reserved node id */
#define F2FS_RESERVED_NODE_NUM		3

#define F2FS_ROOT_INO(sbi)	((sbi)->root_ino_num)
#define F2FS_NODE_INO(sbi)	((sbi)->node_ino_num)
#define F2FS_META_INO(sbi)	((sbi)->meta_ino_num)

#define F2FS_MAX_QUOTAS		3

#define F2FS_ENC_UTF8_12_1	1
#define F2FS_ENC_STRICT_MODE_FL	(1 << 0)
#define f2fs_has_strict_mode(sbi) \
	(sbi->s_encoding_flags & F2FS_ENC_STRICT_MODE_FL)

#define F2FS_IO_SIZE(sbi)	(1 << F2FS_OPTION(sbi).write_io_size_bits) /* Blocks */
#define F2FS_IO_SIZE_KB(sbi)	(1 << (F2FS_OPTION(sbi).write_io_size_bits + 2)) /* KB */
#define F2FS_IO_SIZE_BYTES(sbi)	(1 << (F2FS_OPTION(sbi).write_io_size_bits + 12)) /* B */
#define F2FS_IO_SIZE_BITS(sbi)	(F2FS_OPTION(sbi).write_io_size_bits) /* power of 2 */
#define F2FS_IO_SIZE_MASK(sbi)	(F2FS_IO_SIZE(sbi) - 1)
#define F2FS_IO_ALIGNED(sbi)	(F2FS_IO_SIZE(sbi) > 1)

/* This flag is used by node and meta inodes, and by recovery */
#define GFP_F2FS_ZERO		(GFP_NOFS | __GFP_ZERO)

/*
 * For further optimization on multi-head logs, on-disk layout supports maximum
 * 16 logs by default. The number, 16, is expected to cover all the cases
 * enoughly. The implementaion currently uses no more than 6 logs.
 * Half the logs are used for nodes, and the other half are used for data.
 */
#define MAX_ACTIVE_LOGS	16
#define MAX_ACTIVE_NODE_LOGS	8
#define MAX_ACTIVE_DATA_LOGS	8

#define VERSION_LEN	256
#define MAX_VOLUME_NAME		512
#define MAX_PATH_LEN		64
#define MAX_DEVICES		8

/*
 * For superblock
 */
struct f2fs_device {
	__u8 path[MAX_PATH_LEN];
	__le32 total_segments;
} __packed;

struct f2fs_super_block {
	__le32 magic;			/* Magic Number */
	__le16 major_ver;		/* Major Version */
	__le16 minor_ver;		/* Minor Version */
	__le32 log_sectorsize;		/* log2 sector size in bytes */
	__le32 log_sectors_per_block;	/* log2 # of sectors per block */
	__le32 log_blocksize;		/* log2 block size in bytes */
	__le32 log_blocks_per_seg;	/* log2 # of blocks per segment */
	__le32 segs_per_sec;		/* # of segments per section */
	__le32 secs_per_zone;		/* # of sections per zone */
	__le32 checksum_offset;		/* checksum offset inside super block */
	__le64 block_count;		/* total # of user blocks */
	__le32 section_count;		/* total # of sections */
	__le32 segment_count;		/* total # of segments */
	__le32 segment_count_ckpt;	/* # of segments for checkpoint */
	__le32 segment_count_sit;	/* # of segments for SIT */
	__le32 segment_count_nat;	/* # of segments for NAT */
	__le32 segment_count_ssa;	/* # of segments for SSA */
	__le32 segment_count_main;	/* # of segments for main area */
	__le32 segment0_blkaddr;	/* start block address of segment 0 */
	__le32 cp_blkaddr;		/* start block address of checkpoint */
	__le32 sit_blkaddr;		/* start block address of SIT */
	__le32 nat_blkaddr;		/* start block address of NAT */
	__le32 ssa_blkaddr;		/* start block address of SSA */
	__le32 main_blkaddr;		/* start block address of main area */
	__le32 root_ino;		/* root inode number */
	__le32 node_ino;		/* node inode number */
	__le32 meta_ino;		/* meta inode number */
	__u8 uuid[16];			/* 128-bit uuid for volume */
	__le16 volume_name[MAX_VOLUME_NAME];	/* volume name */
	__le32 extension_count;		/* # of extensions below */
	__u8 extension_list[F2FS_MAX_EXTENSION][F2FS_EXTENSION_LEN];/* extension array */
	__le32 cp_payload;
	__u8 version[VERSION_LEN];	/* the kernel version */
	__u8 init_version[VERSION_LEN];	/* the initial kernel version */
	__le32 feature;			/* defined features */
	__u8 encryption_level;		/* versioning level for encryption */
	__u8 encrypt_pw_salt[16];	/* Salt used for string2key algorithm */
	struct f2fs_device devs[MAX_DEVICES];	/* device list */
	__le32 qf_ino[F2FS_MAX_QUOTAS];	/* quota inode numbers */
	__u8 hot_ext_count;		/* # of hot file extension */
	__le16  s_encoding;		/* Filename charset encoding */
	__le16  s_encoding_flags;	/* Filename charset encoding flags */
	__u8 reserved[306];		/* valid reserved region */
	__le32 crc;			/* checksum of superblock */
} __packed;

/*
 * For checkpoint
 */
#define CP_DISABLED_QUICK_FLAG		0x00002000
#define CP_DISABLED_FLAG		0x00001000
#define CP_QUOTA_NEED_FSCK_FLAG		0x00000800
#define CP_LARGE_NAT_BITMAP_FLAG	0x00000400
#define CP_NOCRC_RECOVERY_FLAG	0x00000200
#define CP_TRIMMED_FLAG		0x00000100
#define CP_NAT_BITS_FLAG	0x00000080
#define CP_CRC_RECOVERY_FLAG	0x00000040
#define CP_FASTBOOT_FLAG	0x00000020
#define CP_FSCK_FLAG		0x00000010
#define CP_ERROR_FLAG		0x00000008
#define CP_COMPACT_SUM_FLAG	0x00000004
#define CP_ORPHAN_PRESENT_FLAG	0x00000002
#define CP_UMOUNT_FLAG		0x00000001

#define F2FS_CP_PACKS		2	/* # of checkpoint packs */

struct f2fs_checkpoint {
	__le64 checkpoint_ver;		/* checkpoint block version number */
	__le64 user_block_count;	/* # of user blocks */
	__le64 valid_block_count;	/* # of valid blocks in main area */
	__le32 rsvd_segment_count;	/* # of reserved segments for gc */
	__le32 overprov_segment_count;	/* # of overprovision segments */
	__le32 free_segment_count;	/* # of free segments in main area */

	/* information of current node segments */
	__le32 cur_node_segno[MAX_ACTIVE_NODE_LOGS];
	__le16 cur_node_blkoff[MAX_ACTIVE_NODE_LOGS];
	/* information of current data segments */
	__le32 cur_data_segno[MAX_ACTIVE_DATA_LOGS];
	__le16 cur_data_blkoff[MAX_ACTIVE_DATA_LOGS];
	__le32 ckpt_flags;		/* Flags : umount and journal_present */
	__le32 cp_pack_total_block_count;	/* total # of one cp pack */
	__le32 cp_pack_start_sum;	/* start block number of data summary */
	__le32 valid_node_count;	/* Total number of valid nodes */
	__le32 valid_inode_count;	/* Total number of valid inodes */
	__le32 next_free_nid;		/* Next free node number */
	__le32 sit_ver_bitmap_bytesize;	/* Default value 64 */
	__le32 nat_ver_bitmap_bytesize; /* Default value 256 */
	__le32 checksum_offset;		/* checksum offset inside cp block */
	__le64 elapsed_time;		/* mounted time */
	/* allocation type of current segment */
	unsigned char alloc_type[MAX_ACTIVE_LOGS];

	/* SIT and NAT version bitmap */
	unsigned char sit_nat_version_bitmap[1];
} __packed;

#define CP_CHKSUM_OFFSET	4092	/* default chksum offset in checkpoint */
#define CP_MIN_CHKSUM_OFFSET						\
	(offsetof(struct f2fs_checkpoint, sit_nat_version_bitmap))

/*
 * For orphan inode management
 */
#define F2FS_ORPHANS_PER_BLOCK	1020

#define GET_ORPHAN_BLOCKS(n)	(((n) + F2FS_ORPHANS_PER_BLOCK - 1) / \
					F2FS_ORPHANS_PER_BLOCK)

struct f2fs_orphan_block {
	__le32 ino[F2FS_ORPHANS_PER_BLOCK];	/* inode numbers */
	__le32 reserved;	/* reserved */
	__le16 blk_addr;	/* block index in current CP */
	__le16 blk_count;	/* Number of orphan inode blocks in CP */
	__le32 entry_count;	/* Total number of orphan nodes in current CP */
	__le32 check_sum;	/* CRC32 for orphan inode block */
} __packed;

/*
 * For NODE structure
 */
struct f2fs_extent {
	__le32 fofs;		/* start file offset of the extent */
	__le32 blk;		/* start block address of the extent */
	__le32 len;		/* length of the extent */
} __packed;

#define F2FS_NAME_LEN		255
/* 200 bytes for inline xattrs by default */
#define DEFAULT_INLINE_XATTR_ADDRS	50
#define DEF_ADDRS_PER_INODE	923	/* Address Pointers in an Inode */
#define CUR_ADDRS_PER_INODE(inode)	(DEF_ADDRS_PER_INODE - \
					get_extra_isize(inode))
#define DEF_NIDS_PER_INODE	5	/* Node IDs in an Inode */
#define ADDRS_PER_INODE(inode)	addrs_per_inode(inode)
#define DEF_ADDRS_PER_BLOCK	1018	/* Address Pointers in a Direct Block */
#define ADDRS_PER_BLOCK(inode)	addrs_per_block(inode)
#define NIDS_PER_BLOCK		1018	/* Node IDs in an Indirect Block */

#define ADDRS_PER_PAGE(page, inode)	\
	(IS_INODE(page) ? ADDRS_PER_INODE(inode) : ADDRS_PER_BLOCK(inode))

#define	NODE_DIR1_BLOCK		(DEF_ADDRS_PER_INODE + 1)
#define	NODE_DIR2_BLOCK		(DEF_ADDRS_PER_INODE + 2)
#define	NODE_IND1_BLOCK		(DEF_ADDRS_PER_INODE + 3)
#define	NODE_IND2_BLOCK		(DEF_ADDRS_PER_INODE + 4)
#define	NODE_DIND_BLOCK		(DEF_ADDRS_PER_INODE + 5)

#define F2FS_INLINE_XATTR	0x01	/* file inline xattr flag */
#define F2FS_INLINE_DATA	0x02	/* file inline data flag */
#define F2FS_INLINE_DENTRY	0x04	/* file inline dentry flag */
#define F2FS_DATA_EXIST		0x08	/* file inline data exist flag */
#define F2FS_INLINE_DOTS	0x10	/* file having implicit dot dentries */
#define F2FS_EXTRA_ATTR		0x20	/* file having extra attribute */
#define F2FS_PIN_FILE		0x40	/* file should not be gced */

struct f2fs_inode {
	__le16 i_mode;			/* file mode */
	__u8 i_advise;			/* file hints */
	__u8 i_inline;			/* file inline flags */
	__le32 i_uid;			/* user ID */
	__le32 i_gid;			/* group ID */
	__le32 i_links;			/* links count */
	__le64 i_size;			/* file size in bytes */
	__le64 i_blocks;		/* file size in blocks */
	__le64 i_atime;			/* access time */
	__le64 i_ctime;			/* change time */
	__le64 i_mtime;			/* modification time */
	__le32 i_atime_nsec;		/* access time in nano scale */
	__le32 i_ctime_nsec;		/* change time in nano scale */
	__le32 i_mtime_nsec;		/* modification time in nano scale */
	__le32 i_generation;		/* file version (for NFS) */
	union {
		__le32 i_current_depth;	/* only for directory depth */
		__le16 i_gc_failures;	/*
					 * # of gc failures on pinned file.
					 * only for regular files.
					 */
	};
	__le32 i_xattr_nid;		/* nid to save xattr */
	__le32 i_flags;			/* file attributes */
	__le32 i_pino;			/* parent inode number */
	__le32 i_namelen;		/* file name length */
	__u8 i_name[F2FS_NAME_LEN];	/* file name for SPOR */
	__u8 i_dir_level;		/* dentry_level for large dir */

	struct f2fs_extent i_ext;	/* caching a largest extent */

	union {
		struct {
			__le16 i_extra_isize;	/* extra inode attribute size */
			__le16 i_inline_xattr_size;	/* inline xattr size, unit: 4 bytes */
			__le32 i_projid;	/* project id */
			__le32 i_inode_checksum;/* inode meta checksum */
			__le64 i_crtime;	/* creation time */
			__le32 i_crtime_nsec;	/* creation time in nano scale */
			__le32 i_extra_end[0];	/* for attribute size calculation */
		} __packed;
		__le32 i_addr[DEF_ADDRS_PER_INODE];	/* Pointers to data blocks */
	};
	__le32 i_nid[DEF_NIDS_PER_INODE];	/* direct(2), indirect(2),
						double_indirect(1) node id */
} __packed;

struct direct_node {
	__le32 addr[DEF_ADDRS_PER_BLOCK];	/* array of data block address */
} __packed;

struct indirect_node {
	__le32 nid[NIDS_PER_BLOCK];	/* array of data block address */
} __packed;

enum {
	COLD_BIT_SHIFT = 0,
	FSYNC_BIT_SHIFT,
	DENT_BIT_SHIFT,
	OFFSET_BIT_SHIFT
};

#define OFFSET_BIT_MASK		(0x07)	/* (0x01 << OFFSET_BIT_SHIFT) - 1 */

struct node_footer {
	__le32 nid;		/* node id */
	__le32 ino;		/* inode number */
	__le32 flag;		/* include cold/fsync/dentry marks and offset */
	__le64 cp_ver;		/* checkpoint version */
	__le32 next_blkaddr;	/* next node page block address */
} __packed;

struct f2fs_node {
	/* can be one of three types: inode, direct, and indirect types */
	union {
		struct f2fs_inode i;
		struct direct_node dn;
		struct indirect_node in;
	};
	struct node_footer footer;
} __packed;

/*
 * For NAT entries
 */
#define NAT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_nat_entry))

struct f2fs_nat_entry {
	__u8 version;		/* latest version of cached nat entry */
	__le32 ino;		/* inode number */
	__le32 block_addr;	/* block address */
} __packed;

struct f2fs_nat_block {
	struct f2fs_nat_entry entries[NAT_ENTRY_PER_BLOCK];
} __packed;

/*
 * For SIT entries
 *
 * Each segment is 2MB in size by default so that a bitmap for validity of
 * there-in blocks should occupy 64 bytes, 512 bits.
 * Not allow to change this.
 */
#define SIT_VBLOCK_MAP_SIZE 64
#define SIT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_sit_entry))

/*
 * F2FS uses 4 bytes to represent block address. As a result, supported size of
 * disk is 16 TB and it equals to 16 * 1024 * 1024 / 2 segments.
 */
#define F2FS_MAX_SEGMENT       ((16 * 1024 * 1024) / 2)

/*
 * Note that f2fs_sit_entry->vblocks has the following bit-field information.
 * [15:10] : allocation type such as CURSEG_XXXX_TYPE
 * [9:0] : valid block count
 */
#define SIT_VBLOCKS_SHIFT	10
#define SIT_VBLOCKS_MASK	((1 << SIT_VBLOCKS_SHIFT) - 1)
#define GET_SIT_VBLOCKS(raw_sit)				\
	(le16_to_cpu((raw_sit)->vblocks) & SIT_VBLOCKS_MASK)
#define GET_SIT_TYPE(raw_sit)					\
	((le16_to_cpu((raw_sit)->vblocks) & ~SIT_VBLOCKS_MASK)	\
	 >> SIT_VBLOCKS_SHIFT)

struct f2fs_sit_entry {
	__le16 vblocks;				/* reference above */
	__u8 valid_map[SIT_VBLOCK_MAP_SIZE];	/* bitmap for valid blocks */
	__le64 mtime;				/* segment age for cleaning */
} __packed;

struct f2fs_sit_block {
	struct f2fs_sit_entry entries[SIT_ENTRY_PER_BLOCK];
} __packed;

/*
 * For segment summary
 *
 * One summary block contains exactly 512 summary entries, which represents
 * exactly 2MB segment by default. Not allow to change the basic units.
 *
 * NOTE: For initializing fields, you must use set_summary
 *
 * - If data page, nid represents dnode's nid
 * - If node page, nid represents the node page's nid.
 *
 * The ofs_in_node is used by only data page. It represents offset
 * from node's page's beginning to get a data block address.
 * ex) data_blkaddr = (block_t)(nodepage_start_address + ofs_in_node)
 */
#define ENTRIES_IN_SUM		512
#define	SUMMARY_SIZE		(7)	/* sizeof(struct summary) */
#define	SUM_FOOTER_SIZE		(5)	/* sizeof(struct summary_footer) */
#define SUM_ENTRY_SIZE		(SUMMARY_SIZE * ENTRIES_IN_SUM)

/* a summary entry for a 4KB-sized block in a segment */
struct f2fs_summary {
	__le32 nid;		/* parent node id */
	union {
		__u8 reserved[3];
		struct {
			__u8 version;		/* node version number */
			__le16 ofs_in_node;	/* block index in parent node */
		} __packed;
	};
} __packed;

/* summary block type, node or data, is stored to the summary_footer */
#define SUM_TYPE_NODE		(1)
#define SUM_TYPE_DATA		(0)

struct summary_footer {
	unsigned char entry_type;	/* SUM_TYPE_XXX */
	__le32 check_sum;		/* summary checksum */
} __packed;

#define SUM_JOURNAL_SIZE	(F2FS_BLKSIZE - SUM_FOOTER_SIZE -\
				SUM_ENTRY_SIZE)
#define NAT_JOURNAL_ENTRIES	((SUM_JOURNAL_SIZE - 2) /\
				sizeof(struct nat_journal_entry))
#define NAT_JOURNAL_RESERVED	((SUM_JOURNAL_SIZE - 2) %\
				sizeof(struct nat_journal_entry))
#define SIT_JOURNAL_ENTRIES	((SUM_JOURNAL_SIZE - 2) /\
				sizeof(struct sit_journal_entry))
#define SIT_JOURNAL_RESERVED	((SUM_JOURNAL_SIZE - 2) %\
				sizeof(struct sit_journal_entry))

/* Reserved area should make size of f2fs_extra_info equals to
 * that of nat_journal and sit_journal.
 */
#define EXTRA_INFO_RESERVED	(SUM_JOURNAL_SIZE - 2 - 8)

/*
 * frequently updated NAT/SIT entries can be stored in the spare area in
 * summary blocks
 */
enum {
	NAT_JOURNAL = 0,
	SIT_JOURNAL
};

struct nat_journal_entry {
	__le32 nid;
	struct f2fs_nat_entry ne;
} __packed;

struct nat_journal {
	struct nat_journal_entry entries[NAT_JOURNAL_ENTRIES];
	__u8 reserved[NAT_JOURNAL_RESERVED];
} __packed;

struct sit_journal_entry {
	__le32 segno;
	struct f2fs_sit_entry se;
} __packed;

struct sit_journal {
	struct sit_journal_entry entries[SIT_JOURNAL_ENTRIES];
	__u8 reserved[SIT_JOURNAL_RESERVED];
} __packed;

struct f2fs_extra_info {
	__le64 kbytes_written;
	__u8 reserved[EXTRA_INFO_RESERVED];
} __packed;

struct f2fs_journal {
	union {
		__le16 n_nats;
		__le16 n_sits;
	};
	/* spare area is used by NAT or SIT journals or extra info */
	union {
		struct nat_journal nat_j;
		struct sit_journal sit_j;
		struct f2fs_extra_info info;
	};
} __packed;

/* 4KB-sized summary block structure */
struct f2fs_summary_block {
	struct f2fs_summary entries[ENTRIES_IN_SUM];
	struct f2fs_journal journal;
	struct summary_footer footer;
} __packed;

/*
 * For directory operations
 */
#define F2FS_DOT_HASH		0
#define F2FS_DDOT_HASH		F2FS_DOT_HASH
#define F2FS_MAX_HASH		(~((0x3ULL) << 62))
#define F2FS_HASH_COL_BIT	((0x1ULL) << 63)

typedef __le32	f2fs_hash_t;

/* One directory entry slot covers 8bytes-long file name */
#define F2FS_SLOT_LEN		8
#define F2FS_SLOT_LEN_BITS	3

#define GET_DENTRY_SLOTS(x) (((x) + F2FS_SLOT_LEN - 1) >> F2FS_SLOT_LEN_BITS)

/* MAX level for dir lookup */
#define MAX_DIR_HASH_DEPTH	63

/* MAX buckets in one level of dir */
#define MAX_DIR_BUCKETS		(1 << ((MAX_DIR_HASH_DEPTH / 2) - 1))

/*
 * space utilization of regular dentry and inline dentry (w/o extra reservation)
 *		regular dentry		inline dentry (def)	inline dentry (min)
 * bitmap	1 * 27 = 27		1 * 23 = 23		1 * 1 = 1
 * reserved	1 * 3 = 3		1 * 7 = 7		1 * 1 = 1
 * dentry	11 * 214 = 2354		11 * 182 = 2002		11 * 2 = 22
 * filename	8 * 214 = 1712		8 * 182 = 1456		8 * 2 = 16
 * total	4096			3488			40
 *
 * Note: there are more reserved space in inline dentry than in regular
 * dentry, when converting inline dentry we should handle this carefully.
 */
#define NR_DENTRY_IN_BLOCK	214	/* the number of dentry in a block */
#define SIZE_OF_DIR_ENTRY	11	/* by byte */
#define SIZE_OF_DENTRY_BITMAP	((NR_DENTRY_IN_BLOCK + BITS_PER_BYTE - 1) / \
					BITS_PER_BYTE)
#define SIZE_OF_RESERVED	(PAGE_SIZE - ((SIZE_OF_DIR_ENTRY + \
				F2FS_SLOT_LEN) * \
				NR_DENTRY_IN_BLOCK + SIZE_OF_DENTRY_BITMAP))
#define MIN_INLINE_DENTRY_SIZE		40	/* just include '.' and '..' entries */

/* One directory entry slot representing F2FS_SLOT_LEN-sized file name */
struct f2fs_dir_entry {
	__le32 hash_code;	/* hash code of file name */
	__le32 ino;		/* inode number */
	__le16 name_len;	/* length of file name */
	__u8 file_type;		/* file type */
} __packed;

/* 4KB-sized directory entry block */
struct f2fs_dentry_block {
	/* validity bitmap for directory entries in each block */
	__u8 dentry_bitmap[SIZE_OF_DENTRY_BITMAP];
	__u8 reserved[SIZE_OF_RESERVED];
	struct f2fs_dir_entry dentry[NR_DENTRY_IN_BLOCK];
	__u8 filename[NR_DENTRY_IN_BLOCK][F2FS_SLOT_LEN];
} __packed;

/* file types used in inode_info->flags */
enum {
	F2FS_FT_UNKNOWN,
	F2FS_FT_REG_FILE,
	F2FS_FT_DIR,
	F2FS_FT_CHRDEV,
	F2FS_FT_BLKDEV,
	F2FS_FT_FIFO,
	F2FS_FT_SOCK,
	F2FS_FT_SYMLINK,
	F2FS_FT_MAX
};

#define S_SHIFT 12

#define	F2FS_DEF_PROJID		0	/* default project ID */

#endif  /* _LINUX_F2FS_FS_H */