1 // SPDX-License-Identifier: GPL-2.0
2 /**
3  * include/linux/f2fs_fs.h
4  *
5  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
6  *             http://www.samsung.com/
7  */
8 #ifndef _LINUX_F2FS_FS_H
9 #define _LINUX_F2FS_FS_H
10 
11 #include <linux/pagemap.h>
12 #include <linux/types.h>
13 
14 #define F2FS_SUPER_OFFSET		1024	/* byte-size offset */
15 #define F2FS_MIN_LOG_SECTOR_SIZE	9	/* 9 bits for 512 bytes */
16 #define F2FS_MAX_LOG_SECTOR_SIZE	12	/* 12 bits for 4096 bytes */
17 #define F2FS_LOG_SECTORS_PER_BLOCK	3	/* log number for sector/blk */
18 #define F2FS_BLKSIZE			4096	/* support only 4KB block */
19 #define F2FS_BLKSIZE_BITS		12	/* bits for F2FS_BLKSIZE */
20 #define F2FS_MAX_EXTENSION		64	/* # of extension entries */
21 #define F2FS_EXTENSION_LEN		8	/* max size of extension */
22 #define F2FS_BLK_ALIGN(x)	(((x) + F2FS_BLKSIZE - 1) >> F2FS_BLKSIZE_BITS)
23 
24 #define NULL_ADDR		((block_t)0)	/* used as block_t addresses */
25 #define NEW_ADDR		((block_t)-1)	/* used as block_t addresses */
26 
27 #define F2FS_BYTES_TO_BLK(bytes)	((bytes) >> F2FS_BLKSIZE_BITS)
28 #define F2FS_BLK_TO_BYTES(blk)		((blk) << F2FS_BLKSIZE_BITS)
29 
30 /* 0, 1(node nid), 2(meta nid) are reserved node id */
31 #define F2FS_RESERVED_NODE_NUM		3
32 
33 #define F2FS_ROOT_INO(sbi)	((sbi)->root_ino_num)
34 #define F2FS_NODE_INO(sbi)	((sbi)->node_ino_num)
35 #define F2FS_META_INO(sbi)	((sbi)->meta_ino_num)
36 
37 #define F2FS_MAX_QUOTAS		3
38 
39 #define F2FS_ENC_UTF8_12_1	1
40 #define F2FS_ENC_STRICT_MODE_FL	(1 << 0)
41 #define f2fs_has_strict_mode(sbi) \
42 	(sbi->s_encoding_flags & F2FS_ENC_STRICT_MODE_FL)
43 
44 #define F2FS_IO_SIZE(sbi)	(1 << F2FS_OPTION(sbi).write_io_size_bits) /* Blocks */
45 #define F2FS_IO_SIZE_KB(sbi)	(1 << (F2FS_OPTION(sbi).write_io_size_bits + 2)) /* KB */
46 #define F2FS_IO_SIZE_BYTES(sbi)	(1 << (F2FS_OPTION(sbi).write_io_size_bits + 12)) /* B */
47 #define F2FS_IO_SIZE_BITS(sbi)	(F2FS_OPTION(sbi).write_io_size_bits) /* power of 2 */
48 #define F2FS_IO_SIZE_MASK(sbi)	(F2FS_IO_SIZE(sbi) - 1)
49 #define F2FS_IO_ALIGNED(sbi)	(F2FS_IO_SIZE(sbi) > 1)
50 
51 /* This flag is used by node and meta inodes, and by recovery */
52 #define GFP_F2FS_ZERO		(GFP_NOFS | __GFP_ZERO)
53 
54 /*
55  * For further optimization on multi-head logs, on-disk layout supports maximum
56  * 16 logs by default. The number, 16, is expected to cover all the cases
57  * enoughly. The implementaion currently uses no more than 6 logs.
58  * Half the logs are used for nodes, and the other half are used for data.
59  */
60 #define MAX_ACTIVE_LOGS	16
61 #define MAX_ACTIVE_NODE_LOGS	8
62 #define MAX_ACTIVE_DATA_LOGS	8
63 
64 #define VERSION_LEN	256
65 #define MAX_VOLUME_NAME		512
66 #define MAX_PATH_LEN		64
67 #define MAX_DEVICES		8
68 
69 /*
70  * For superblock
71  */
72 struct f2fs_device {
73 	__u8 path[MAX_PATH_LEN];
74 	__le32 total_segments;
75 } __packed;
76 
77 struct f2fs_super_block {
78 	__le32 magic;			/* Magic Number */
79 	__le16 major_ver;		/* Major Version */
80 	__le16 minor_ver;		/* Minor Version */
81 	__le32 log_sectorsize;		/* log2 sector size in bytes */
82 	__le32 log_sectors_per_block;	/* log2 # of sectors per block */
83 	__le32 log_blocksize;		/* log2 block size in bytes */
84 	__le32 log_blocks_per_seg;	/* log2 # of blocks per segment */
85 	__le32 segs_per_sec;		/* # of segments per section */
86 	__le32 secs_per_zone;		/* # of sections per zone */
87 	__le32 checksum_offset;		/* checksum offset inside super block */
88 	__le64 block_count;		/* total # of user blocks */
89 	__le32 section_count;		/* total # of sections */
90 	__le32 segment_count;		/* total # of segments */
91 	__le32 segment_count_ckpt;	/* # of segments for checkpoint */
92 	__le32 segment_count_sit;	/* # of segments for SIT */
93 	__le32 segment_count_nat;	/* # of segments for NAT */
94 	__le32 segment_count_ssa;	/* # of segments for SSA */
95 	__le32 segment_count_main;	/* # of segments for main area */
96 	__le32 segment0_blkaddr;	/* start block address of segment 0 */
97 	__le32 cp_blkaddr;		/* start block address of checkpoint */
98 	__le32 sit_blkaddr;		/* start block address of SIT */
99 	__le32 nat_blkaddr;		/* start block address of NAT */
100 	__le32 ssa_blkaddr;		/* start block address of SSA */
101 	__le32 main_blkaddr;		/* start block address of main area */
102 	__le32 root_ino;		/* root inode number */
103 	__le32 node_ino;		/* node inode number */
104 	__le32 meta_ino;		/* meta inode number */
105 	__u8 uuid[16];			/* 128-bit uuid for volume */
106 	__le16 volume_name[MAX_VOLUME_NAME];	/* volume name */
107 	__le32 extension_count;		/* # of extensions below */
108 	__u8 extension_list[F2FS_MAX_EXTENSION][F2FS_EXTENSION_LEN];/* extension array */
109 	__le32 cp_payload;
110 	__u8 version[VERSION_LEN];	/* the kernel version */
111 	__u8 init_version[VERSION_LEN];	/* the initial kernel version */
112 	__le32 feature;			/* defined features */
113 	__u8 encryption_level;		/* versioning level for encryption */
114 	__u8 encrypt_pw_salt[16];	/* Salt used for string2key algorithm */
115 	struct f2fs_device devs[MAX_DEVICES];	/* device list */
116 	__le32 qf_ino[F2FS_MAX_QUOTAS];	/* quota inode numbers */
117 	__u8 hot_ext_count;		/* # of hot file extension */
118 	__le16  s_encoding;		/* Filename charset encoding */
119 	__le16  s_encoding_flags;	/* Filename charset encoding flags */
120 	__u8 reserved[306];		/* valid reserved region */
121 	__le32 crc;			/* checksum of superblock */
122 } __packed;
123 
124 /*
125  * For checkpoint
126  */
127 #define CP_DISABLED_QUICK_FLAG		0x00002000
128 #define CP_DISABLED_FLAG		0x00001000
129 #define CP_QUOTA_NEED_FSCK_FLAG		0x00000800
130 #define CP_LARGE_NAT_BITMAP_FLAG	0x00000400
131 #define CP_NOCRC_RECOVERY_FLAG	0x00000200
132 #define CP_TRIMMED_FLAG		0x00000100
133 #define CP_NAT_BITS_FLAG	0x00000080
134 #define CP_CRC_RECOVERY_FLAG	0x00000040
135 #define CP_FASTBOOT_FLAG	0x00000020
136 #define CP_FSCK_FLAG		0x00000010
137 #define CP_ERROR_FLAG		0x00000008
138 #define CP_COMPACT_SUM_FLAG	0x00000004
139 #define CP_ORPHAN_PRESENT_FLAG	0x00000002
140 #define CP_UMOUNT_FLAG		0x00000001
141 
142 #define F2FS_CP_PACKS		2	/* # of checkpoint packs */
143 
144 struct f2fs_checkpoint {
145 	__le64 checkpoint_ver;		/* checkpoint block version number */
146 	__le64 user_block_count;	/* # of user blocks */
147 	__le64 valid_block_count;	/* # of valid blocks in main area */
148 	__le32 rsvd_segment_count;	/* # of reserved segments for gc */
149 	__le32 overprov_segment_count;	/* # of overprovision segments */
150 	__le32 free_segment_count;	/* # of free segments in main area */
151 
152 	/* information of current node segments */
153 	__le32 cur_node_segno[MAX_ACTIVE_NODE_LOGS];
154 	__le16 cur_node_blkoff[MAX_ACTIVE_NODE_LOGS];
155 	/* information of current data segments */
156 	__le32 cur_data_segno[MAX_ACTIVE_DATA_LOGS];
157 	__le16 cur_data_blkoff[MAX_ACTIVE_DATA_LOGS];
158 	__le32 ckpt_flags;		/* Flags : umount and journal_present */
159 	__le32 cp_pack_total_block_count;	/* total # of one cp pack */
160 	__le32 cp_pack_start_sum;	/* start block number of data summary */
161 	__le32 valid_node_count;	/* Total number of valid nodes */
162 	__le32 valid_inode_count;	/* Total number of valid inodes */
163 	__le32 next_free_nid;		/* Next free node number */
164 	__le32 sit_ver_bitmap_bytesize;	/* Default value 64 */
165 	__le32 nat_ver_bitmap_bytesize; /* Default value 256 */
166 	__le32 checksum_offset;		/* checksum offset inside cp block */
167 	__le64 elapsed_time;		/* mounted time */
168 	/* allocation type of current segment */
169 	unsigned char alloc_type[MAX_ACTIVE_LOGS];
170 
171 	/* SIT and NAT version bitmap */
172 	unsigned char sit_nat_version_bitmap[1];
173 } __packed;
174 
175 #define CP_CHKSUM_OFFSET	4092	/* default chksum offset in checkpoint */
176 #define CP_MIN_CHKSUM_OFFSET						\
177 	(offsetof(struct f2fs_checkpoint, sit_nat_version_bitmap))
178 
179 /*
180  * For orphan inode management
181  */
182 #define F2FS_ORPHANS_PER_BLOCK	1020
183 
184 #define GET_ORPHAN_BLOCKS(n)	(((n) + F2FS_ORPHANS_PER_BLOCK - 1) / \
185 					F2FS_ORPHANS_PER_BLOCK)
186 
187 struct f2fs_orphan_block {
188 	__le32 ino[F2FS_ORPHANS_PER_BLOCK];	/* inode numbers */
189 	__le32 reserved;	/* reserved */
190 	__le16 blk_addr;	/* block index in current CP */
191 	__le16 blk_count;	/* Number of orphan inode blocks in CP */
192 	__le32 entry_count;	/* Total number of orphan nodes in current CP */
193 	__le32 check_sum;	/* CRC32 for orphan inode block */
194 } __packed;
195 
196 /*
197  * For NODE structure
198  */
199 struct f2fs_extent {
200 	__le32 fofs;		/* start file offset of the extent */
201 	__le32 blk;		/* start block address of the extent */
202 	__le32 len;		/* length of the extent */
203 } __packed;
204 
205 #define F2FS_NAME_LEN		255
206 /* 200 bytes for inline xattrs by default */
207 #define DEFAULT_INLINE_XATTR_ADDRS	50
208 #define DEF_ADDRS_PER_INODE	923	/* Address Pointers in an Inode */
209 #define CUR_ADDRS_PER_INODE(inode)	(DEF_ADDRS_PER_INODE - \
210 					get_extra_isize(inode))
211 #define DEF_NIDS_PER_INODE	5	/* Node IDs in an Inode */
212 #define ADDRS_PER_INODE(inode)	addrs_per_inode(inode)
213 #define DEF_ADDRS_PER_BLOCK	1018	/* Address Pointers in a Direct Block */
214 #define ADDRS_PER_BLOCK(inode)	addrs_per_block(inode)
215 #define NIDS_PER_BLOCK		1018	/* Node IDs in an Indirect Block */
216 
217 #define ADDRS_PER_PAGE(page, inode)	\
218 	(IS_INODE(page) ? ADDRS_PER_INODE(inode) : ADDRS_PER_BLOCK(inode))
219 
220 #define	NODE_DIR1_BLOCK		(DEF_ADDRS_PER_INODE + 1)
221 #define	NODE_DIR2_BLOCK		(DEF_ADDRS_PER_INODE + 2)
222 #define	NODE_IND1_BLOCK		(DEF_ADDRS_PER_INODE + 3)
223 #define	NODE_IND2_BLOCK		(DEF_ADDRS_PER_INODE + 4)
224 #define	NODE_DIND_BLOCK		(DEF_ADDRS_PER_INODE + 5)
225 
226 #define F2FS_INLINE_XATTR	0x01	/* file inline xattr flag */
227 #define F2FS_INLINE_DATA	0x02	/* file inline data flag */
228 #define F2FS_INLINE_DENTRY	0x04	/* file inline dentry flag */
229 #define F2FS_DATA_EXIST		0x08	/* file inline data exist flag */
230 #define F2FS_INLINE_DOTS	0x10	/* file having implicit dot dentries */
231 #define F2FS_EXTRA_ATTR		0x20	/* file having extra attribute */
232 #define F2FS_PIN_FILE		0x40	/* file should not be gced */
233 
234 struct f2fs_inode {
235 	__le16 i_mode;			/* file mode */
236 	__u8 i_advise;			/* file hints */
237 	__u8 i_inline;			/* file inline flags */
238 	__le32 i_uid;			/* user ID */
239 	__le32 i_gid;			/* group ID */
240 	__le32 i_links;			/* links count */
241 	__le64 i_size;			/* file size in bytes */
242 	__le64 i_blocks;		/* file size in blocks */
243 	__le64 i_atime;			/* access time */
244 	__le64 i_ctime;			/* change time */
245 	__le64 i_mtime;			/* modification time */
246 	__le32 i_atime_nsec;		/* access time in nano scale */
247 	__le32 i_ctime_nsec;		/* change time in nano scale */
248 	__le32 i_mtime_nsec;		/* modification time in nano scale */
249 	__le32 i_generation;		/* file version (for NFS) */
250 	union {
251 		__le32 i_current_depth;	/* only for directory depth */
252 		__le16 i_gc_failures;	/*
253 					 * # of gc failures on pinned file.
254 					 * only for regular files.
255 					 */
256 	};
257 	__le32 i_xattr_nid;		/* nid to save xattr */
258 	__le32 i_flags;			/* file attributes */
259 	__le32 i_pino;			/* parent inode number */
260 	__le32 i_namelen;		/* file name length */
261 	__u8 i_name[F2FS_NAME_LEN];	/* file name for SPOR */
262 	__u8 i_dir_level;		/* dentry_level for large dir */
263 
264 	struct f2fs_extent i_ext;	/* caching a largest extent */
265 
266 	union {
267 		struct {
268 			__le16 i_extra_isize;	/* extra inode attribute size */
269 			__le16 i_inline_xattr_size;	/* inline xattr size, unit: 4 bytes */
270 			__le32 i_projid;	/* project id */
271 			__le32 i_inode_checksum;/* inode meta checksum */
272 			__le64 i_crtime;	/* creation time */
273 			__le32 i_crtime_nsec;	/* creation time in nano scale */
274 			__le32 i_extra_end[0];	/* for attribute size calculation */
275 		} __packed;
276 		__le32 i_addr[DEF_ADDRS_PER_INODE];	/* Pointers to data blocks */
277 	};
278 	__le32 i_nid[DEF_NIDS_PER_INODE];	/* direct(2), indirect(2),
279 						double_indirect(1) node id */
280 } __packed;
281 
282 struct direct_node {
283 	__le32 addr[DEF_ADDRS_PER_BLOCK];	/* array of data block address */
284 } __packed;
285 
286 struct indirect_node {
287 	__le32 nid[NIDS_PER_BLOCK];	/* array of data block address */
288 } __packed;
289 
290 enum {
291 	COLD_BIT_SHIFT = 0,
292 	FSYNC_BIT_SHIFT,
293 	DENT_BIT_SHIFT,
294 	OFFSET_BIT_SHIFT
295 };
296 
297 #define OFFSET_BIT_MASK		(0x07)	/* (0x01 << OFFSET_BIT_SHIFT) - 1 */
298 
299 struct node_footer {
300 	__le32 nid;		/* node id */
301 	__le32 ino;		/* inode number */
302 	__le32 flag;		/* include cold/fsync/dentry marks and offset */
303 	__le64 cp_ver;		/* checkpoint version */
304 	__le32 next_blkaddr;	/* next node page block address */
305 } __packed;
306 
307 struct f2fs_node {
308 	/* can be one of three types: inode, direct, and indirect types */
309 	union {
310 		struct f2fs_inode i;
311 		struct direct_node dn;
312 		struct indirect_node in;
313 	};
314 	struct node_footer footer;
315 } __packed;
316 
317 /*
318  * For NAT entries
319  */
320 #define NAT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_nat_entry))
321 
322 struct f2fs_nat_entry {
323 	__u8 version;		/* latest version of cached nat entry */
324 	__le32 ino;		/* inode number */
325 	__le32 block_addr;	/* block address */
326 } __packed;
327 
328 struct f2fs_nat_block {
329 	struct f2fs_nat_entry entries[NAT_ENTRY_PER_BLOCK];
330 } __packed;
331 
332 /*
333  * For SIT entries
334  *
335  * Each segment is 2MB in size by default so that a bitmap for validity of
336  * there-in blocks should occupy 64 bytes, 512 bits.
337  * Not allow to change this.
338  */
339 #define SIT_VBLOCK_MAP_SIZE 64
340 #define SIT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_sit_entry))
341 
342 /*
343  * F2FS uses 4 bytes to represent block address. As a result, supported size of
344  * disk is 16 TB and it equals to 16 * 1024 * 1024 / 2 segments.
345  */
346 #define F2FS_MAX_SEGMENT       ((16 * 1024 * 1024) / 2)
347 
348 /*
349  * Note that f2fs_sit_entry->vblocks has the following bit-field information.
350  * [15:10] : allocation type such as CURSEG_XXXX_TYPE
351  * [9:0] : valid block count
352  */
353 #define SIT_VBLOCKS_SHIFT	10
354 #define SIT_VBLOCKS_MASK	((1 << SIT_VBLOCKS_SHIFT) - 1)
355 #define GET_SIT_VBLOCKS(raw_sit)				\
356 	(le16_to_cpu((raw_sit)->vblocks) & SIT_VBLOCKS_MASK)
357 #define GET_SIT_TYPE(raw_sit)					\
358 	((le16_to_cpu((raw_sit)->vblocks) & ~SIT_VBLOCKS_MASK)	\
359 	 >> SIT_VBLOCKS_SHIFT)
360 
361 struct f2fs_sit_entry {
362 	__le16 vblocks;				/* reference above */
363 	__u8 valid_map[SIT_VBLOCK_MAP_SIZE];	/* bitmap for valid blocks */
364 	__le64 mtime;				/* segment age for cleaning */
365 } __packed;
366 
367 struct f2fs_sit_block {
368 	struct f2fs_sit_entry entries[SIT_ENTRY_PER_BLOCK];
369 } __packed;
370 
371 /*
372  * For segment summary
373  *
374  * One summary block contains exactly 512 summary entries, which represents
375  * exactly 2MB segment by default. Not allow to change the basic units.
376  *
377  * NOTE: For initializing fields, you must use set_summary
378  *
379  * - If data page, nid represents dnode's nid
380  * - If node page, nid represents the node page's nid.
381  *
382  * The ofs_in_node is used by only data page. It represents offset
383  * from node's page's beginning to get a data block address.
384  * ex) data_blkaddr = (block_t)(nodepage_start_address + ofs_in_node)
385  */
386 #define ENTRIES_IN_SUM		512
387 #define	SUMMARY_SIZE		(7)	/* sizeof(struct summary) */
388 #define	SUM_FOOTER_SIZE		(5)	/* sizeof(struct summary_footer) */
389 #define SUM_ENTRY_SIZE		(SUMMARY_SIZE * ENTRIES_IN_SUM)
390 
391 /* a summary entry for a 4KB-sized block in a segment */
392 struct f2fs_summary {
393 	__le32 nid;		/* parent node id */
394 	union {
395 		__u8 reserved[3];
396 		struct {
397 			__u8 version;		/* node version number */
398 			__le16 ofs_in_node;	/* block index in parent node */
399 		} __packed;
400 	};
401 } __packed;
402 
403 /* summary block type, node or data, is stored to the summary_footer */
404 #define SUM_TYPE_NODE		(1)
405 #define SUM_TYPE_DATA		(0)
406 
407 struct summary_footer {
408 	unsigned char entry_type;	/* SUM_TYPE_XXX */
409 	__le32 check_sum;		/* summary checksum */
410 } __packed;
411 
412 #define SUM_JOURNAL_SIZE	(F2FS_BLKSIZE - SUM_FOOTER_SIZE -\
413 				SUM_ENTRY_SIZE)
414 #define NAT_JOURNAL_ENTRIES	((SUM_JOURNAL_SIZE - 2) /\
415 				sizeof(struct nat_journal_entry))
416 #define NAT_JOURNAL_RESERVED	((SUM_JOURNAL_SIZE - 2) %\
417 				sizeof(struct nat_journal_entry))
418 #define SIT_JOURNAL_ENTRIES	((SUM_JOURNAL_SIZE - 2) /\
419 				sizeof(struct sit_journal_entry))
420 #define SIT_JOURNAL_RESERVED	((SUM_JOURNAL_SIZE - 2) %\
421 				sizeof(struct sit_journal_entry))
422 
423 /* Reserved area should make size of f2fs_extra_info equals to
424  * that of nat_journal and sit_journal.
425  */
426 #define EXTRA_INFO_RESERVED	(SUM_JOURNAL_SIZE - 2 - 8)
427 
428 /*
429  * frequently updated NAT/SIT entries can be stored in the spare area in
430  * summary blocks
431  */
432 enum {
433 	NAT_JOURNAL = 0,
434 	SIT_JOURNAL
435 };
436 
437 struct nat_journal_entry {
438 	__le32 nid;
439 	struct f2fs_nat_entry ne;
440 } __packed;
441 
442 struct nat_journal {
443 	struct nat_journal_entry entries[NAT_JOURNAL_ENTRIES];
444 	__u8 reserved[NAT_JOURNAL_RESERVED];
445 } __packed;
446 
447 struct sit_journal_entry {
448 	__le32 segno;
449 	struct f2fs_sit_entry se;
450 } __packed;
451 
452 struct sit_journal {
453 	struct sit_journal_entry entries[SIT_JOURNAL_ENTRIES];
454 	__u8 reserved[SIT_JOURNAL_RESERVED];
455 } __packed;
456 
457 struct f2fs_extra_info {
458 	__le64 kbytes_written;
459 	__u8 reserved[EXTRA_INFO_RESERVED];
460 } __packed;
461 
462 struct f2fs_journal {
463 	union {
464 		__le16 n_nats;
465 		__le16 n_sits;
466 	};
467 	/* spare area is used by NAT or SIT journals or extra info */
468 	union {
469 		struct nat_journal nat_j;
470 		struct sit_journal sit_j;
471 		struct f2fs_extra_info info;
472 	};
473 } __packed;
474 
475 /* 4KB-sized summary block structure */
476 struct f2fs_summary_block {
477 	struct f2fs_summary entries[ENTRIES_IN_SUM];
478 	struct f2fs_journal journal;
479 	struct summary_footer footer;
480 } __packed;
481 
482 /*
483  * For directory operations
484  */
485 #define F2FS_DOT_HASH		0
486 #define F2FS_DDOT_HASH		F2FS_DOT_HASH
487 #define F2FS_MAX_HASH		(~((0x3ULL) << 62))
488 #define F2FS_HASH_COL_BIT	((0x1ULL) << 63)
489 
490 typedef __le32	f2fs_hash_t;
491 
492 /* One directory entry slot covers 8bytes-long file name */
493 #define F2FS_SLOT_LEN		8
494 #define F2FS_SLOT_LEN_BITS	3
495 
496 #define GET_DENTRY_SLOTS(x) (((x) + F2FS_SLOT_LEN - 1) >> F2FS_SLOT_LEN_BITS)
497 
498 /* MAX level for dir lookup */
499 #define MAX_DIR_HASH_DEPTH	63
500 
501 /* MAX buckets in one level of dir */
502 #define MAX_DIR_BUCKETS		(1 << ((MAX_DIR_HASH_DEPTH / 2) - 1))
503 
504 /*
505  * space utilization of regular dentry and inline dentry (w/o extra reservation)
506  *		regular dentry		inline dentry (def)	inline dentry (min)
507  * bitmap	1 * 27 = 27		1 * 23 = 23		1 * 1 = 1
508  * reserved	1 * 3 = 3		1 * 7 = 7		1 * 1 = 1
509  * dentry	11 * 214 = 2354		11 * 182 = 2002		11 * 2 = 22
510  * filename	8 * 214 = 1712		8 * 182 = 1456		8 * 2 = 16
511  * total	4096			3488			40
512  *
513  * Note: there are more reserved space in inline dentry than in regular
514  * dentry, when converting inline dentry we should handle this carefully.
515  */
516 #define NR_DENTRY_IN_BLOCK	214	/* the number of dentry in a block */
517 #define SIZE_OF_DIR_ENTRY	11	/* by byte */
518 #define SIZE_OF_DENTRY_BITMAP	((NR_DENTRY_IN_BLOCK + BITS_PER_BYTE - 1) / \
519 					BITS_PER_BYTE)
520 #define SIZE_OF_RESERVED	(PAGE_SIZE - ((SIZE_OF_DIR_ENTRY + \
521 				F2FS_SLOT_LEN) * \
522 				NR_DENTRY_IN_BLOCK + SIZE_OF_DENTRY_BITMAP))
523 #define MIN_INLINE_DENTRY_SIZE		40	/* just include '.' and '..' entries */
524 
525 /* One directory entry slot representing F2FS_SLOT_LEN-sized file name */
526 struct f2fs_dir_entry {
527 	__le32 hash_code;	/* hash code of file name */
528 	__le32 ino;		/* inode number */
529 	__le16 name_len;	/* length of file name */
530 	__u8 file_type;		/* file type */
531 } __packed;
532 
533 /* 4KB-sized directory entry block */
534 struct f2fs_dentry_block {
535 	/* validity bitmap for directory entries in each block */
536 	__u8 dentry_bitmap[SIZE_OF_DENTRY_BITMAP];
537 	__u8 reserved[SIZE_OF_RESERVED];
538 	struct f2fs_dir_entry dentry[NR_DENTRY_IN_BLOCK];
539 	__u8 filename[NR_DENTRY_IN_BLOCK][F2FS_SLOT_LEN];
540 } __packed;
541 
542 /* file types used in inode_info->flags */
543 enum {
544 	F2FS_FT_UNKNOWN,
545 	F2FS_FT_REG_FILE,
546 	F2FS_FT_DIR,
547 	F2FS_FT_CHRDEV,
548 	F2FS_FT_BLKDEV,
549 	F2FS_FT_FIFO,
550 	F2FS_FT_SOCK,
551 	F2FS_FT_SYMLINK,
552 	F2FS_FT_MAX
553 };
554 
555 #define S_SHIFT 12
556 
557 #define	F2FS_DEF_PROJID		0	/* default project ID */
558 
559 #endif  /* _LINUX_F2FS_FS_H */
560