xref: /linux/include/linux/f2fs_fs.h (revision f79e4d5f92a129a1159c973735007d4ddc8541f3)
1 /**
2  * include/linux/f2fs_fs.h
3  *
4  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5  *             http://www.samsung.com/
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #ifndef _LINUX_F2FS_FS_H
12 #define _LINUX_F2FS_FS_H
13 
14 #include <linux/pagemap.h>
15 #include <linux/types.h>
16 
17 #define F2FS_SUPER_OFFSET		1024	/* byte-size offset */
18 #define F2FS_MIN_LOG_SECTOR_SIZE	9	/* 9 bits for 512 bytes */
19 #define F2FS_MAX_LOG_SECTOR_SIZE	12	/* 12 bits for 4096 bytes */
20 #define F2FS_LOG_SECTORS_PER_BLOCK	3	/* log number for sector/blk */
21 #define F2FS_BLKSIZE			4096	/* support only 4KB block */
22 #define F2FS_BLKSIZE_BITS		12	/* bits for F2FS_BLKSIZE */
23 #define F2FS_MAX_EXTENSION		64	/* # of extension entries */
24 #define F2FS_EXTENSION_LEN		8	/* max size of extension */
25 #define F2FS_BLK_ALIGN(x)	(((x) + F2FS_BLKSIZE - 1) >> F2FS_BLKSIZE_BITS)
26 
27 #define NULL_ADDR		((block_t)0)	/* used as block_t addresses */
28 #define NEW_ADDR		((block_t)-1)	/* used as block_t addresses */
29 
30 #define F2FS_BYTES_TO_BLK(bytes)	((bytes) >> F2FS_BLKSIZE_BITS)
31 #define F2FS_BLK_TO_BYTES(blk)		((blk) << F2FS_BLKSIZE_BITS)
32 
33 /* 0, 1(node nid), 2(meta nid) are reserved node id */
34 #define F2FS_RESERVED_NODE_NUM		3
35 
36 #define F2FS_ROOT_INO(sbi)	((sbi)->root_ino_num)
37 #define F2FS_NODE_INO(sbi)	((sbi)->node_ino_num)
38 #define F2FS_META_INO(sbi)	((sbi)->meta_ino_num)
39 
40 #define F2FS_MAX_QUOTAS		3
41 
42 #define F2FS_IO_SIZE(sbi)	(1 << F2FS_OPTION(sbi).write_io_size_bits) /* Blocks */
43 #define F2FS_IO_SIZE_KB(sbi)	(1 << (F2FS_OPTION(sbi).write_io_size_bits + 2)) /* KB */
44 #define F2FS_IO_SIZE_BYTES(sbi)	(1 << (F2FS_OPTION(sbi).write_io_size_bits + 12)) /* B */
45 #define F2FS_IO_SIZE_BITS(sbi)	(F2FS_OPTION(sbi).write_io_size_bits) /* power of 2 */
46 #define F2FS_IO_SIZE_MASK(sbi)	(F2FS_IO_SIZE(sbi) - 1)
47 
48 /* This flag is used by node and meta inodes, and by recovery */
49 #define GFP_F2FS_ZERO		(GFP_NOFS | __GFP_ZERO)
50 
51 /*
52  * For further optimization on multi-head logs, on-disk layout supports maximum
53  * 16 logs by default. The number, 16, is expected to cover all the cases
54  * enoughly. The implementaion currently uses no more than 6 logs.
55  * Half the logs are used for nodes, and the other half are used for data.
56  */
57 #define MAX_ACTIVE_LOGS	16
58 #define MAX_ACTIVE_NODE_LOGS	8
59 #define MAX_ACTIVE_DATA_LOGS	8
60 
61 #define VERSION_LEN	256
62 #define MAX_VOLUME_NAME		512
63 #define MAX_PATH_LEN		64
64 #define MAX_DEVICES		8
65 
66 /*
67  * For superblock
68  */
69 struct f2fs_device {
70 	__u8 path[MAX_PATH_LEN];
71 	__le32 total_segments;
72 } __packed;
73 
74 struct f2fs_super_block {
75 	__le32 magic;			/* Magic Number */
76 	__le16 major_ver;		/* Major Version */
77 	__le16 minor_ver;		/* Minor Version */
78 	__le32 log_sectorsize;		/* log2 sector size in bytes */
79 	__le32 log_sectors_per_block;	/* log2 # of sectors per block */
80 	__le32 log_blocksize;		/* log2 block size in bytes */
81 	__le32 log_blocks_per_seg;	/* log2 # of blocks per segment */
82 	__le32 segs_per_sec;		/* # of segments per section */
83 	__le32 secs_per_zone;		/* # of sections per zone */
84 	__le32 checksum_offset;		/* checksum offset inside super block */
85 	__le64 block_count;		/* total # of user blocks */
86 	__le32 section_count;		/* total # of sections */
87 	__le32 segment_count;		/* total # of segments */
88 	__le32 segment_count_ckpt;	/* # of segments for checkpoint */
89 	__le32 segment_count_sit;	/* # of segments for SIT */
90 	__le32 segment_count_nat;	/* # of segments for NAT */
91 	__le32 segment_count_ssa;	/* # of segments for SSA */
92 	__le32 segment_count_main;	/* # of segments for main area */
93 	__le32 segment0_blkaddr;	/* start block address of segment 0 */
94 	__le32 cp_blkaddr;		/* start block address of checkpoint */
95 	__le32 sit_blkaddr;		/* start block address of SIT */
96 	__le32 nat_blkaddr;		/* start block address of NAT */
97 	__le32 ssa_blkaddr;		/* start block address of SSA */
98 	__le32 main_blkaddr;		/* start block address of main area */
99 	__le32 root_ino;		/* root inode number */
100 	__le32 node_ino;		/* node inode number */
101 	__le32 meta_ino;		/* meta inode number */
102 	__u8 uuid[16];			/* 128-bit uuid for volume */
103 	__le16 volume_name[MAX_VOLUME_NAME];	/* volume name */
104 	__le32 extension_count;		/* # of extensions below */
105 	__u8 extension_list[F2FS_MAX_EXTENSION][F2FS_EXTENSION_LEN];/* extension array */
106 	__le32 cp_payload;
107 	__u8 version[VERSION_LEN];	/* the kernel version */
108 	__u8 init_version[VERSION_LEN];	/* the initial kernel version */
109 	__le32 feature;			/* defined features */
110 	__u8 encryption_level;		/* versioning level for encryption */
111 	__u8 encrypt_pw_salt[16];	/* Salt used for string2key algorithm */
112 	struct f2fs_device devs[MAX_DEVICES];	/* device list */
113 	__le32 qf_ino[F2FS_MAX_QUOTAS];	/* quota inode numbers */
114 	__u8 hot_ext_count;		/* # of hot file extension */
115 	__u8 reserved[314];		/* valid reserved region */
116 } __packed;
117 
118 /*
119  * For checkpoint
120  */
121 #define CP_LARGE_NAT_BITMAP_FLAG	0x00000400
122 #define CP_NOCRC_RECOVERY_FLAG	0x00000200
123 #define CP_TRIMMED_FLAG		0x00000100
124 #define CP_NAT_BITS_FLAG	0x00000080
125 #define CP_CRC_RECOVERY_FLAG	0x00000040
126 #define CP_FASTBOOT_FLAG	0x00000020
127 #define CP_FSCK_FLAG		0x00000010
128 #define CP_ERROR_FLAG		0x00000008
129 #define CP_COMPACT_SUM_FLAG	0x00000004
130 #define CP_ORPHAN_PRESENT_FLAG	0x00000002
131 #define CP_UMOUNT_FLAG		0x00000001
132 
133 #define F2FS_CP_PACKS		2	/* # of checkpoint packs */
134 
135 struct f2fs_checkpoint {
136 	__le64 checkpoint_ver;		/* checkpoint block version number */
137 	__le64 user_block_count;	/* # of user blocks */
138 	__le64 valid_block_count;	/* # of valid blocks in main area */
139 	__le32 rsvd_segment_count;	/* # of reserved segments for gc */
140 	__le32 overprov_segment_count;	/* # of overprovision segments */
141 	__le32 free_segment_count;	/* # of free segments in main area */
142 
143 	/* information of current node segments */
144 	__le32 cur_node_segno[MAX_ACTIVE_NODE_LOGS];
145 	__le16 cur_node_blkoff[MAX_ACTIVE_NODE_LOGS];
146 	/* information of current data segments */
147 	__le32 cur_data_segno[MAX_ACTIVE_DATA_LOGS];
148 	__le16 cur_data_blkoff[MAX_ACTIVE_DATA_LOGS];
149 	__le32 ckpt_flags;		/* Flags : umount and journal_present */
150 	__le32 cp_pack_total_block_count;	/* total # of one cp pack */
151 	__le32 cp_pack_start_sum;	/* start block number of data summary */
152 	__le32 valid_node_count;	/* Total number of valid nodes */
153 	__le32 valid_inode_count;	/* Total number of valid inodes */
154 	__le32 next_free_nid;		/* Next free node number */
155 	__le32 sit_ver_bitmap_bytesize;	/* Default value 64 */
156 	__le32 nat_ver_bitmap_bytesize; /* Default value 256 */
157 	__le32 checksum_offset;		/* checksum offset inside cp block */
158 	__le64 elapsed_time;		/* mounted time */
159 	/* allocation type of current segment */
160 	unsigned char alloc_type[MAX_ACTIVE_LOGS];
161 
162 	/* SIT and NAT version bitmap */
163 	unsigned char sit_nat_version_bitmap[1];
164 } __packed;
165 
166 /*
167  * For orphan inode management
168  */
169 #define F2FS_ORPHANS_PER_BLOCK	1020
170 
171 #define GET_ORPHAN_BLOCKS(n)	(((n) + F2FS_ORPHANS_PER_BLOCK - 1) / \
172 					F2FS_ORPHANS_PER_BLOCK)
173 
174 struct f2fs_orphan_block {
175 	__le32 ino[F2FS_ORPHANS_PER_BLOCK];	/* inode numbers */
176 	__le32 reserved;	/* reserved */
177 	__le16 blk_addr;	/* block index in current CP */
178 	__le16 blk_count;	/* Number of orphan inode blocks in CP */
179 	__le32 entry_count;	/* Total number of orphan nodes in current CP */
180 	__le32 check_sum;	/* CRC32 for orphan inode block */
181 } __packed;
182 
183 /*
184  * For NODE structure
185  */
186 struct f2fs_extent {
187 	__le32 fofs;		/* start file offset of the extent */
188 	__le32 blk;		/* start block address of the extent */
189 	__le32 len;		/* lengh of the extent */
190 } __packed;
191 
192 #define F2FS_NAME_LEN		255
193 /* 200 bytes for inline xattrs by default */
194 #define DEFAULT_INLINE_XATTR_ADDRS	50
195 #define DEF_ADDRS_PER_INODE	923	/* Address Pointers in an Inode */
196 #define CUR_ADDRS_PER_INODE(inode)	(DEF_ADDRS_PER_INODE - \
197 					get_extra_isize(inode))
198 #define DEF_NIDS_PER_INODE	5	/* Node IDs in an Inode */
199 #define ADDRS_PER_INODE(inode)	addrs_per_inode(inode)
200 #define ADDRS_PER_BLOCK		1018	/* Address Pointers in a Direct Block */
201 #define NIDS_PER_BLOCK		1018	/* Node IDs in an Indirect Block */
202 
203 #define ADDRS_PER_PAGE(page, inode)	\
204 	(IS_INODE(page) ? ADDRS_PER_INODE(inode) : ADDRS_PER_BLOCK)
205 
206 #define	NODE_DIR1_BLOCK		(DEF_ADDRS_PER_INODE + 1)
207 #define	NODE_DIR2_BLOCK		(DEF_ADDRS_PER_INODE + 2)
208 #define	NODE_IND1_BLOCK		(DEF_ADDRS_PER_INODE + 3)
209 #define	NODE_IND2_BLOCK		(DEF_ADDRS_PER_INODE + 4)
210 #define	NODE_DIND_BLOCK		(DEF_ADDRS_PER_INODE + 5)
211 
212 #define F2FS_INLINE_XATTR	0x01	/* file inline xattr flag */
213 #define F2FS_INLINE_DATA	0x02	/* file inline data flag */
214 #define F2FS_INLINE_DENTRY	0x04	/* file inline dentry flag */
215 #define F2FS_DATA_EXIST		0x08	/* file inline data exist flag */
216 #define F2FS_INLINE_DOTS	0x10	/* file having implicit dot dentries */
217 #define F2FS_EXTRA_ATTR		0x20	/* file having extra attribute */
218 #define F2FS_PIN_FILE		0x40	/* file should not be gced */
219 
220 struct f2fs_inode {
221 	__le16 i_mode;			/* file mode */
222 	__u8 i_advise;			/* file hints */
223 	__u8 i_inline;			/* file inline flags */
224 	__le32 i_uid;			/* user ID */
225 	__le32 i_gid;			/* group ID */
226 	__le32 i_links;			/* links count */
227 	__le64 i_size;			/* file size in bytes */
228 	__le64 i_blocks;		/* file size in blocks */
229 	__le64 i_atime;			/* access time */
230 	__le64 i_ctime;			/* change time */
231 	__le64 i_mtime;			/* modification time */
232 	__le32 i_atime_nsec;		/* access time in nano scale */
233 	__le32 i_ctime_nsec;		/* change time in nano scale */
234 	__le32 i_mtime_nsec;		/* modification time in nano scale */
235 	__le32 i_generation;		/* file version (for NFS) */
236 	union {
237 		__le32 i_current_depth;	/* only for directory depth */
238 		__le16 i_gc_failures;	/*
239 					 * # of gc failures on pinned file.
240 					 * only for regular files.
241 					 */
242 	};
243 	__le32 i_xattr_nid;		/* nid to save xattr */
244 	__le32 i_flags;			/* file attributes */
245 	__le32 i_pino;			/* parent inode number */
246 	__le32 i_namelen;		/* file name length */
247 	__u8 i_name[F2FS_NAME_LEN];	/* file name for SPOR */
248 	__u8 i_dir_level;		/* dentry_level for large dir */
249 
250 	struct f2fs_extent i_ext;	/* caching a largest extent */
251 
252 	union {
253 		struct {
254 			__le16 i_extra_isize;	/* extra inode attribute size */
255 			__le16 i_inline_xattr_size;	/* inline xattr size, unit: 4 bytes */
256 			__le32 i_projid;	/* project id */
257 			__le32 i_inode_checksum;/* inode meta checksum */
258 			__le64 i_crtime;	/* creation time */
259 			__le32 i_crtime_nsec;	/* creation time in nano scale */
260 			__le32 i_extra_end[0];	/* for attribute size calculation */
261 		} __packed;
262 		__le32 i_addr[DEF_ADDRS_PER_INODE];	/* Pointers to data blocks */
263 	};
264 	__le32 i_nid[DEF_NIDS_PER_INODE];	/* direct(2), indirect(2),
265 						double_indirect(1) node id */
266 } __packed;
267 
268 struct direct_node {
269 	__le32 addr[ADDRS_PER_BLOCK];	/* array of data block address */
270 } __packed;
271 
272 struct indirect_node {
273 	__le32 nid[NIDS_PER_BLOCK];	/* array of data block address */
274 } __packed;
275 
276 enum {
277 	COLD_BIT_SHIFT = 0,
278 	FSYNC_BIT_SHIFT,
279 	DENT_BIT_SHIFT,
280 	OFFSET_BIT_SHIFT
281 };
282 
283 #define OFFSET_BIT_MASK		(0x07)	/* (0x01 << OFFSET_BIT_SHIFT) - 1 */
284 
285 struct node_footer {
286 	__le32 nid;		/* node id */
287 	__le32 ino;		/* inode nunmber */
288 	__le32 flag;		/* include cold/fsync/dentry marks and offset */
289 	__le64 cp_ver;		/* checkpoint version */
290 	__le32 next_blkaddr;	/* next node page block address */
291 } __packed;
292 
293 struct f2fs_node {
294 	/* can be one of three types: inode, direct, and indirect types */
295 	union {
296 		struct f2fs_inode i;
297 		struct direct_node dn;
298 		struct indirect_node in;
299 	};
300 	struct node_footer footer;
301 } __packed;
302 
303 /*
304  * For NAT entries
305  */
306 #define NAT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_nat_entry))
307 #define NAT_ENTRY_BITMAP_SIZE	((NAT_ENTRY_PER_BLOCK + 7) / 8)
308 #define NAT_ENTRY_BITMAP_SIZE_ALIGNED				\
309 	((NAT_ENTRY_BITMAP_SIZE + BITS_PER_LONG - 1) /		\
310 	BITS_PER_LONG * BITS_PER_LONG)
311 
312 
313 struct f2fs_nat_entry {
314 	__u8 version;		/* latest version of cached nat entry */
315 	__le32 ino;		/* inode number */
316 	__le32 block_addr;	/* block address */
317 } __packed;
318 
319 struct f2fs_nat_block {
320 	struct f2fs_nat_entry entries[NAT_ENTRY_PER_BLOCK];
321 } __packed;
322 
323 /*
324  * For SIT entries
325  *
326  * Each segment is 2MB in size by default so that a bitmap for validity of
327  * there-in blocks should occupy 64 bytes, 512 bits.
328  * Not allow to change this.
329  */
330 #define SIT_VBLOCK_MAP_SIZE 64
331 #define SIT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_sit_entry))
332 
333 /*
334  * F2FS uses 4 bytes to represent block address. As a result, supported size of
335  * disk is 16 TB and it equals to 16 * 1024 * 1024 / 2 segments.
336  */
337 #define F2FS_MAX_SEGMENT       ((16 * 1024 * 1024) / 2)
338 
339 /*
340  * Note that f2fs_sit_entry->vblocks has the following bit-field information.
341  * [15:10] : allocation type such as CURSEG_XXXX_TYPE
342  * [9:0] : valid block count
343  */
344 #define SIT_VBLOCKS_SHIFT	10
345 #define SIT_VBLOCKS_MASK	((1 << SIT_VBLOCKS_SHIFT) - 1)
346 #define GET_SIT_VBLOCKS(raw_sit)				\
347 	(le16_to_cpu((raw_sit)->vblocks) & SIT_VBLOCKS_MASK)
348 #define GET_SIT_TYPE(raw_sit)					\
349 	((le16_to_cpu((raw_sit)->vblocks) & ~SIT_VBLOCKS_MASK)	\
350 	 >> SIT_VBLOCKS_SHIFT)
351 
352 struct f2fs_sit_entry {
353 	__le16 vblocks;				/* reference above */
354 	__u8 valid_map[SIT_VBLOCK_MAP_SIZE];	/* bitmap for valid blocks */
355 	__le64 mtime;				/* segment age for cleaning */
356 } __packed;
357 
358 struct f2fs_sit_block {
359 	struct f2fs_sit_entry entries[SIT_ENTRY_PER_BLOCK];
360 } __packed;
361 
362 /*
363  * For segment summary
364  *
365  * One summary block contains exactly 512 summary entries, which represents
366  * exactly 2MB segment by default. Not allow to change the basic units.
367  *
368  * NOTE: For initializing fields, you must use set_summary
369  *
370  * - If data page, nid represents dnode's nid
371  * - If node page, nid represents the node page's nid.
372  *
373  * The ofs_in_node is used by only data page. It represents offset
374  * from node's page's beginning to get a data block address.
375  * ex) data_blkaddr = (block_t)(nodepage_start_address + ofs_in_node)
376  */
377 #define ENTRIES_IN_SUM		512
378 #define	SUMMARY_SIZE		(7)	/* sizeof(struct summary) */
379 #define	SUM_FOOTER_SIZE		(5)	/* sizeof(struct summary_footer) */
380 #define SUM_ENTRY_SIZE		(SUMMARY_SIZE * ENTRIES_IN_SUM)
381 
382 /* a summary entry for a 4KB-sized block in a segment */
383 struct f2fs_summary {
384 	__le32 nid;		/* parent node id */
385 	union {
386 		__u8 reserved[3];
387 		struct {
388 			__u8 version;		/* node version number */
389 			__le16 ofs_in_node;	/* block index in parent node */
390 		} __packed;
391 	};
392 } __packed;
393 
394 /* summary block type, node or data, is stored to the summary_footer */
395 #define SUM_TYPE_NODE		(1)
396 #define SUM_TYPE_DATA		(0)
397 
398 struct summary_footer {
399 	unsigned char entry_type;	/* SUM_TYPE_XXX */
400 	__le32 check_sum;		/* summary checksum */
401 } __packed;
402 
403 #define SUM_JOURNAL_SIZE	(F2FS_BLKSIZE - SUM_FOOTER_SIZE -\
404 				SUM_ENTRY_SIZE)
405 #define NAT_JOURNAL_ENTRIES	((SUM_JOURNAL_SIZE - 2) /\
406 				sizeof(struct nat_journal_entry))
407 #define NAT_JOURNAL_RESERVED	((SUM_JOURNAL_SIZE - 2) %\
408 				sizeof(struct nat_journal_entry))
409 #define SIT_JOURNAL_ENTRIES	((SUM_JOURNAL_SIZE - 2) /\
410 				sizeof(struct sit_journal_entry))
411 #define SIT_JOURNAL_RESERVED	((SUM_JOURNAL_SIZE - 2) %\
412 				sizeof(struct sit_journal_entry))
413 
414 /* Reserved area should make size of f2fs_extra_info equals to
415  * that of nat_journal and sit_journal.
416  */
417 #define EXTRA_INFO_RESERVED	(SUM_JOURNAL_SIZE - 2 - 8)
418 
419 /*
420  * frequently updated NAT/SIT entries can be stored in the spare area in
421  * summary blocks
422  */
423 enum {
424 	NAT_JOURNAL = 0,
425 	SIT_JOURNAL
426 };
427 
428 struct nat_journal_entry {
429 	__le32 nid;
430 	struct f2fs_nat_entry ne;
431 } __packed;
432 
433 struct nat_journal {
434 	struct nat_journal_entry entries[NAT_JOURNAL_ENTRIES];
435 	__u8 reserved[NAT_JOURNAL_RESERVED];
436 } __packed;
437 
438 struct sit_journal_entry {
439 	__le32 segno;
440 	struct f2fs_sit_entry se;
441 } __packed;
442 
443 struct sit_journal {
444 	struct sit_journal_entry entries[SIT_JOURNAL_ENTRIES];
445 	__u8 reserved[SIT_JOURNAL_RESERVED];
446 } __packed;
447 
448 struct f2fs_extra_info {
449 	__le64 kbytes_written;
450 	__u8 reserved[EXTRA_INFO_RESERVED];
451 } __packed;
452 
453 struct f2fs_journal {
454 	union {
455 		__le16 n_nats;
456 		__le16 n_sits;
457 	};
458 	/* spare area is used by NAT or SIT journals or extra info */
459 	union {
460 		struct nat_journal nat_j;
461 		struct sit_journal sit_j;
462 		struct f2fs_extra_info info;
463 	};
464 } __packed;
465 
466 /* 4KB-sized summary block structure */
467 struct f2fs_summary_block {
468 	struct f2fs_summary entries[ENTRIES_IN_SUM];
469 	struct f2fs_journal journal;
470 	struct summary_footer footer;
471 } __packed;
472 
473 /*
474  * For directory operations
475  */
476 #define F2FS_DOT_HASH		0
477 #define F2FS_DDOT_HASH		F2FS_DOT_HASH
478 #define F2FS_MAX_HASH		(~((0x3ULL) << 62))
479 #define F2FS_HASH_COL_BIT	((0x1ULL) << 63)
480 
481 typedef __le32	f2fs_hash_t;
482 
483 /* One directory entry slot covers 8bytes-long file name */
484 #define F2FS_SLOT_LEN		8
485 #define F2FS_SLOT_LEN_BITS	3
486 
487 #define GET_DENTRY_SLOTS(x) (((x) + F2FS_SLOT_LEN - 1) >> F2FS_SLOT_LEN_BITS)
488 
489 /* MAX level for dir lookup */
490 #define MAX_DIR_HASH_DEPTH	63
491 
492 /* MAX buckets in one level of dir */
493 #define MAX_DIR_BUCKETS		(1 << ((MAX_DIR_HASH_DEPTH / 2) - 1))
494 
495 /*
496  * space utilization of regular dentry and inline dentry (w/o extra reservation)
497  *		regular dentry			inline dentry
498  * bitmap	1 * 27 = 27			1 * 23 = 23
499  * reserved	1 * 3 = 3			1 * 7 = 7
500  * dentry	11 * 214 = 2354			11 * 182 = 2002
501  * filename	8 * 214 = 1712			8 * 182 = 1456
502  * total	4096				3488
503  *
504  * Note: there are more reserved space in inline dentry than in regular
505  * dentry, when converting inline dentry we should handle this carefully.
506  */
507 #define NR_DENTRY_IN_BLOCK	214	/* the number of dentry in a block */
508 #define SIZE_OF_DIR_ENTRY	11	/* by byte */
509 #define SIZE_OF_DENTRY_BITMAP	((NR_DENTRY_IN_BLOCK + BITS_PER_BYTE - 1) / \
510 					BITS_PER_BYTE)
511 #define SIZE_OF_RESERVED	(PAGE_SIZE - ((SIZE_OF_DIR_ENTRY + \
512 				F2FS_SLOT_LEN) * \
513 				NR_DENTRY_IN_BLOCK + SIZE_OF_DENTRY_BITMAP))
514 
515 /* One directory entry slot representing F2FS_SLOT_LEN-sized file name */
516 struct f2fs_dir_entry {
517 	__le32 hash_code;	/* hash code of file name */
518 	__le32 ino;		/* inode number */
519 	__le16 name_len;	/* lengh of file name */
520 	__u8 file_type;		/* file type */
521 } __packed;
522 
523 /* 4KB-sized directory entry block */
524 struct f2fs_dentry_block {
525 	/* validity bitmap for directory entries in each block */
526 	__u8 dentry_bitmap[SIZE_OF_DENTRY_BITMAP];
527 	__u8 reserved[SIZE_OF_RESERVED];
528 	struct f2fs_dir_entry dentry[NR_DENTRY_IN_BLOCK];
529 	__u8 filename[NR_DENTRY_IN_BLOCK][F2FS_SLOT_LEN];
530 } __packed;
531 
532 /* file types used in inode_info->flags */
533 enum {
534 	F2FS_FT_UNKNOWN,
535 	F2FS_FT_REG_FILE,
536 	F2FS_FT_DIR,
537 	F2FS_FT_CHRDEV,
538 	F2FS_FT_BLKDEV,
539 	F2FS_FT_FIFO,
540 	F2FS_FT_SOCK,
541 	F2FS_FT_SYMLINK,
542 	F2FS_FT_MAX
543 };
544 
545 #define S_SHIFT 12
546 
547 #define	F2FS_DEF_PROJID		0	/* default project ID */
548 
549 #endif  /* _LINUX_F2FS_FS_H */
550