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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 #define COMPRESS_ADDR		((block_t)-2)	/* used as compressed data flag */
27 
28 #define F2FS_BYTES_TO_BLK(bytes)	((bytes) >> F2FS_BLKSIZE_BITS)
29 #define F2FS_BLK_TO_BYTES(blk)		((blk) << F2FS_BLKSIZE_BITS)
30 
31 /* 0, 1(node nid), 2(meta nid) are reserved node id */
32 #define F2FS_RESERVED_NODE_NUM		3
33 
34 #define F2FS_ROOT_INO(sbi)	((sbi)->root_ino_num)
35 #define F2FS_NODE_INO(sbi)	((sbi)->node_ino_num)
36 #define F2FS_META_INO(sbi)	((sbi)->meta_ino_num)
37 #define F2FS_COMPRESS_INO(sbi)	(NM_I(sbi)->max_nid)
38 
39 #define F2FS_MAX_QUOTAS		3
40 
41 #define F2FS_ENC_UTF8_12_1	1
42 
43 #define F2FS_IO_SIZE(sbi)	(1 << F2FS_OPTION(sbi).write_io_size_bits) /* Blocks */
44 #define F2FS_IO_SIZE_KB(sbi)	(1 << (F2FS_OPTION(sbi).write_io_size_bits + 2)) /* KB */
45 #define F2FS_IO_SIZE_BYTES(sbi)	(1 << (F2FS_OPTION(sbi).write_io_size_bits + 12)) /* B */
46 #define F2FS_IO_SIZE_BITS(sbi)	(F2FS_OPTION(sbi).write_io_size_bits) /* power of 2 */
47 #define F2FS_IO_SIZE_MASK(sbi)	(F2FS_IO_SIZE(sbi) - 1)
48 #define F2FS_IO_ALIGNED(sbi)	(F2FS_IO_SIZE(sbi) > 1)
49 
50 /* This flag is used by node and meta inodes, and by recovery */
51 #define GFP_F2FS_ZERO		(GFP_NOFS | __GFP_ZERO)
52 
53 /*
54  * For further optimization on multi-head logs, on-disk layout supports maximum
55  * 16 logs by default. The number, 16, is expected to cover all the cases
56  * enoughly. The implementaion currently uses no more than 6 logs.
57  * Half the logs are used for nodes, and the other half are used for data.
58  */
59 #define MAX_ACTIVE_LOGS	16
60 #define MAX_ACTIVE_NODE_LOGS	8
61 #define MAX_ACTIVE_DATA_LOGS	8
62 
63 #define VERSION_LEN	256
64 #define MAX_VOLUME_NAME		512
65 #define MAX_PATH_LEN		64
66 #define MAX_DEVICES		8
67 
68 /*
69  * For superblock
70  */
71 struct f2fs_device {
72 	__u8 path[MAX_PATH_LEN];
73 	__le32 total_segments;
74 } __packed;
75 
76 /* reason of stop_checkpoint */
77 enum stop_cp_reason {
78 	STOP_CP_REASON_SHUTDOWN,
79 	STOP_CP_REASON_FAULT_INJECT,
80 	STOP_CP_REASON_META_PAGE,
81 	STOP_CP_REASON_WRITE_FAIL,
82 	STOP_CP_REASON_CORRUPTED_SUMMARY,
83 	STOP_CP_REASON_UPDATE_INODE,
84 	STOP_CP_REASON_FLUSH_FAIL,
85 	STOP_CP_REASON_MAX,
86 };
87 
88 #define	MAX_STOP_REASON			32
89 
90 struct f2fs_super_block {
91 	__le32 magic;			/* Magic Number */
92 	__le16 major_ver;		/* Major Version */
93 	__le16 minor_ver;		/* Minor Version */
94 	__le32 log_sectorsize;		/* log2 sector size in bytes */
95 	__le32 log_sectors_per_block;	/* log2 # of sectors per block */
96 	__le32 log_blocksize;		/* log2 block size in bytes */
97 	__le32 log_blocks_per_seg;	/* log2 # of blocks per segment */
98 	__le32 segs_per_sec;		/* # of segments per section */
99 	__le32 secs_per_zone;		/* # of sections per zone */
100 	__le32 checksum_offset;		/* checksum offset inside super block */
101 	__le64 block_count;		/* total # of user blocks */
102 	__le32 section_count;		/* total # of sections */
103 	__le32 segment_count;		/* total # of segments */
104 	__le32 segment_count_ckpt;	/* # of segments for checkpoint */
105 	__le32 segment_count_sit;	/* # of segments for SIT */
106 	__le32 segment_count_nat;	/* # of segments for NAT */
107 	__le32 segment_count_ssa;	/* # of segments for SSA */
108 	__le32 segment_count_main;	/* # of segments for main area */
109 	__le32 segment0_blkaddr;	/* start block address of segment 0 */
110 	__le32 cp_blkaddr;		/* start block address of checkpoint */
111 	__le32 sit_blkaddr;		/* start block address of SIT */
112 	__le32 nat_blkaddr;		/* start block address of NAT */
113 	__le32 ssa_blkaddr;		/* start block address of SSA */
114 	__le32 main_blkaddr;		/* start block address of main area */
115 	__le32 root_ino;		/* root inode number */
116 	__le32 node_ino;		/* node inode number */
117 	__le32 meta_ino;		/* meta inode number */
118 	__u8 uuid[16];			/* 128-bit uuid for volume */
119 	__le16 volume_name[MAX_VOLUME_NAME];	/* volume name */
120 	__le32 extension_count;		/* # of extensions below */
121 	__u8 extension_list[F2FS_MAX_EXTENSION][F2FS_EXTENSION_LEN];/* extension array */
122 	__le32 cp_payload;
123 	__u8 version[VERSION_LEN];	/* the kernel version */
124 	__u8 init_version[VERSION_LEN];	/* the initial kernel version */
125 	__le32 feature;			/* defined features */
126 	__u8 encryption_level;		/* versioning level for encryption */
127 	__u8 encrypt_pw_salt[16];	/* Salt used for string2key algorithm */
128 	struct f2fs_device devs[MAX_DEVICES];	/* device list */
129 	__le32 qf_ino[F2FS_MAX_QUOTAS];	/* quota inode numbers */
130 	__u8 hot_ext_count;		/* # of hot file extension */
131 	__le16  s_encoding;		/* Filename charset encoding */
132 	__le16  s_encoding_flags;	/* Filename charset encoding flags */
133 	__u8 s_stop_reason[MAX_STOP_REASON];	/* stop checkpoint reason */
134 	__u8 reserved[274];		/* valid reserved region */
135 	__le32 crc;			/* checksum of superblock */
136 } __packed;
137 
138 /*
139  * For checkpoint
140  */
141 #define CP_RESIZEFS_FLAG		0x00004000
142 #define CP_DISABLED_QUICK_FLAG		0x00002000
143 #define CP_DISABLED_FLAG		0x00001000
144 #define CP_QUOTA_NEED_FSCK_FLAG		0x00000800
145 #define CP_LARGE_NAT_BITMAP_FLAG	0x00000400
146 #define CP_NOCRC_RECOVERY_FLAG	0x00000200
147 #define CP_TRIMMED_FLAG		0x00000100
148 #define CP_NAT_BITS_FLAG	0x00000080
149 #define CP_CRC_RECOVERY_FLAG	0x00000040
150 #define CP_FASTBOOT_FLAG	0x00000020
151 #define CP_FSCK_FLAG		0x00000010
152 #define CP_ERROR_FLAG		0x00000008
153 #define CP_COMPACT_SUM_FLAG	0x00000004
154 #define CP_ORPHAN_PRESENT_FLAG	0x00000002
155 #define CP_UMOUNT_FLAG		0x00000001
156 
157 #define F2FS_CP_PACKS		2	/* # of checkpoint packs */
158 
159 struct f2fs_checkpoint {
160 	__le64 checkpoint_ver;		/* checkpoint block version number */
161 	__le64 user_block_count;	/* # of user blocks */
162 	__le64 valid_block_count;	/* # of valid blocks in main area */
163 	__le32 rsvd_segment_count;	/* # of reserved segments for gc */
164 	__le32 overprov_segment_count;	/* # of overprovision segments */
165 	__le32 free_segment_count;	/* # of free segments in main area */
166 
167 	/* information of current node segments */
168 	__le32 cur_node_segno[MAX_ACTIVE_NODE_LOGS];
169 	__le16 cur_node_blkoff[MAX_ACTIVE_NODE_LOGS];
170 	/* information of current data segments */
171 	__le32 cur_data_segno[MAX_ACTIVE_DATA_LOGS];
172 	__le16 cur_data_blkoff[MAX_ACTIVE_DATA_LOGS];
173 	__le32 ckpt_flags;		/* Flags : umount and journal_present */
174 	__le32 cp_pack_total_block_count;	/* total # of one cp pack */
175 	__le32 cp_pack_start_sum;	/* start block number of data summary */
176 	__le32 valid_node_count;	/* Total number of valid nodes */
177 	__le32 valid_inode_count;	/* Total number of valid inodes */
178 	__le32 next_free_nid;		/* Next free node number */
179 	__le32 sit_ver_bitmap_bytesize;	/* Default value 64 */
180 	__le32 nat_ver_bitmap_bytesize; /* Default value 256 */
181 	__le32 checksum_offset;		/* checksum offset inside cp block */
182 	__le64 elapsed_time;		/* mounted time */
183 	/* allocation type of current segment */
184 	unsigned char alloc_type[MAX_ACTIVE_LOGS];
185 
186 	/* SIT and NAT version bitmap */
187 	unsigned char sit_nat_version_bitmap[];
188 } __packed;
189 
190 #define CP_CHKSUM_OFFSET	4092	/* default chksum offset in checkpoint */
191 #define CP_MIN_CHKSUM_OFFSET						\
192 	(offsetof(struct f2fs_checkpoint, sit_nat_version_bitmap))
193 
194 /*
195  * For orphan inode management
196  */
197 #define F2FS_ORPHANS_PER_BLOCK	1020
198 
199 #define GET_ORPHAN_BLOCKS(n)	(((n) + F2FS_ORPHANS_PER_BLOCK - 1) / \
200 					F2FS_ORPHANS_PER_BLOCK)
201 
202 struct f2fs_orphan_block {
203 	__le32 ino[F2FS_ORPHANS_PER_BLOCK];	/* inode numbers */
204 	__le32 reserved;	/* reserved */
205 	__le16 blk_addr;	/* block index in current CP */
206 	__le16 blk_count;	/* Number of orphan inode blocks in CP */
207 	__le32 entry_count;	/* Total number of orphan nodes in current CP */
208 	__le32 check_sum;	/* CRC32 for orphan inode block */
209 } __packed;
210 
211 /*
212  * For NODE structure
213  */
214 struct f2fs_extent {
215 	__le32 fofs;		/* start file offset of the extent */
216 	__le32 blk;		/* start block address of the extent */
217 	__le32 len;		/* length of the extent */
218 } __packed;
219 
220 #define F2FS_NAME_LEN		255
221 /* 200 bytes for inline xattrs by default */
222 #define DEFAULT_INLINE_XATTR_ADDRS	50
223 #define DEF_ADDRS_PER_INODE	923	/* Address Pointers in an Inode */
224 #define CUR_ADDRS_PER_INODE(inode)	(DEF_ADDRS_PER_INODE - \
225 					get_extra_isize(inode))
226 #define DEF_NIDS_PER_INODE	5	/* Node IDs in an Inode */
227 #define ADDRS_PER_INODE(inode)	addrs_per_inode(inode)
228 #define DEF_ADDRS_PER_BLOCK	1018	/* Address Pointers in a Direct Block */
229 #define ADDRS_PER_BLOCK(inode)	addrs_per_block(inode)
230 #define NIDS_PER_BLOCK		1018	/* Node IDs in an Indirect Block */
231 
232 #define ADDRS_PER_PAGE(page, inode)	\
233 	(IS_INODE(page) ? ADDRS_PER_INODE(inode) : ADDRS_PER_BLOCK(inode))
234 
235 #define	NODE_DIR1_BLOCK		(DEF_ADDRS_PER_INODE + 1)
236 #define	NODE_DIR2_BLOCK		(DEF_ADDRS_PER_INODE + 2)
237 #define	NODE_IND1_BLOCK		(DEF_ADDRS_PER_INODE + 3)
238 #define	NODE_IND2_BLOCK		(DEF_ADDRS_PER_INODE + 4)
239 #define	NODE_DIND_BLOCK		(DEF_ADDRS_PER_INODE + 5)
240 
241 #define F2FS_INLINE_XATTR	0x01	/* file inline xattr flag */
242 #define F2FS_INLINE_DATA	0x02	/* file inline data flag */
243 #define F2FS_INLINE_DENTRY	0x04	/* file inline dentry flag */
244 #define F2FS_DATA_EXIST		0x08	/* file inline data exist flag */
245 #define F2FS_INLINE_DOTS	0x10	/* file having implicit dot dentries */
246 #define F2FS_EXTRA_ATTR		0x20	/* file having extra attribute */
247 #define F2FS_PIN_FILE		0x40	/* file should not be gced */
248 #define F2FS_COMPRESS_RELEASED	0x80	/* file released compressed blocks */
249 
250 struct f2fs_inode {
251 	__le16 i_mode;			/* file mode */
252 	__u8 i_advise;			/* file hints */
253 	__u8 i_inline;			/* file inline flags */
254 	__le32 i_uid;			/* user ID */
255 	__le32 i_gid;			/* group ID */
256 	__le32 i_links;			/* links count */
257 	__le64 i_size;			/* file size in bytes */
258 	__le64 i_blocks;		/* file size in blocks */
259 	__le64 i_atime;			/* access time */
260 	__le64 i_ctime;			/* change time */
261 	__le64 i_mtime;			/* modification time */
262 	__le32 i_atime_nsec;		/* access time in nano scale */
263 	__le32 i_ctime_nsec;		/* change time in nano scale */
264 	__le32 i_mtime_nsec;		/* modification time in nano scale */
265 	__le32 i_generation;		/* file version (for NFS) */
266 	union {
267 		__le32 i_current_depth;	/* only for directory depth */
268 		__le16 i_gc_failures;	/*
269 					 * # of gc failures on pinned file.
270 					 * only for regular files.
271 					 */
272 	};
273 	__le32 i_xattr_nid;		/* nid to save xattr */
274 	__le32 i_flags;			/* file attributes */
275 	__le32 i_pino;			/* parent inode number */
276 	__le32 i_namelen;		/* file name length */
277 	__u8 i_name[F2FS_NAME_LEN];	/* file name for SPOR */
278 	__u8 i_dir_level;		/* dentry_level for large dir */
279 
280 	struct f2fs_extent i_ext;	/* caching a largest extent */
281 
282 	union {
283 		struct {
284 			__le16 i_extra_isize;	/* extra inode attribute size */
285 			__le16 i_inline_xattr_size;	/* inline xattr size, unit: 4 bytes */
286 			__le32 i_projid;	/* project id */
287 			__le32 i_inode_checksum;/* inode meta checksum */
288 			__le64 i_crtime;	/* creation time */
289 			__le32 i_crtime_nsec;	/* creation time in nano scale */
290 			__le64 i_compr_blocks;	/* # of compressed blocks */
291 			__u8 i_compress_algorithm;	/* compress algorithm */
292 			__u8 i_log_cluster_size;	/* log of cluster size */
293 			__le16 i_compress_flag;		/* compress flag */
294 						/* 0 bit: chksum flag
295 						 * [10,15] bits: compress level
296 						 */
297 			__le32 i_extra_end[0];	/* for attribute size calculation */
298 		} __packed;
299 		__le32 i_addr[DEF_ADDRS_PER_INODE];	/* Pointers to data blocks */
300 	};
301 	__le32 i_nid[DEF_NIDS_PER_INODE];	/* direct(2), indirect(2),
302 						double_indirect(1) node id */
303 } __packed;
304 
305 struct direct_node {
306 	__le32 addr[DEF_ADDRS_PER_BLOCK];	/* array of data block address */
307 } __packed;
308 
309 struct indirect_node {
310 	__le32 nid[NIDS_PER_BLOCK];	/* array of data block address */
311 } __packed;
312 
313 enum {
314 	COLD_BIT_SHIFT = 0,
315 	FSYNC_BIT_SHIFT,
316 	DENT_BIT_SHIFT,
317 	OFFSET_BIT_SHIFT
318 };
319 
320 #define OFFSET_BIT_MASK		(0x07)	/* (0x01 << OFFSET_BIT_SHIFT) - 1 */
321 
322 struct node_footer {
323 	__le32 nid;		/* node id */
324 	__le32 ino;		/* inode number */
325 	__le32 flag;		/* include cold/fsync/dentry marks and offset */
326 	__le64 cp_ver;		/* checkpoint version */
327 	__le32 next_blkaddr;	/* next node page block address */
328 } __packed;
329 
330 struct f2fs_node {
331 	/* can be one of three types: inode, direct, and indirect types */
332 	union {
333 		struct f2fs_inode i;
334 		struct direct_node dn;
335 		struct indirect_node in;
336 	};
337 	struct node_footer footer;
338 } __packed;
339 
340 /*
341  * For NAT entries
342  */
343 #define NAT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_nat_entry))
344 
345 struct f2fs_nat_entry {
346 	__u8 version;		/* latest version of cached nat entry */
347 	__le32 ino;		/* inode number */
348 	__le32 block_addr;	/* block address */
349 } __packed;
350 
351 struct f2fs_nat_block {
352 	struct f2fs_nat_entry entries[NAT_ENTRY_PER_BLOCK];
353 } __packed;
354 
355 /*
356  * For SIT entries
357  *
358  * Each segment is 2MB in size by default so that a bitmap for validity of
359  * there-in blocks should occupy 64 bytes, 512 bits.
360  * Not allow to change this.
361  */
362 #define SIT_VBLOCK_MAP_SIZE 64
363 #define SIT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_sit_entry))
364 
365 /*
366  * F2FS uses 4 bytes to represent block address. As a result, supported size of
367  * disk is 16 TB and it equals to 16 * 1024 * 1024 / 2 segments.
368  */
369 #define F2FS_MAX_SEGMENT       ((16 * 1024 * 1024) / 2)
370 
371 /*
372  * Note that f2fs_sit_entry->vblocks has the following bit-field information.
373  * [15:10] : allocation type such as CURSEG_XXXX_TYPE
374  * [9:0] : valid block count
375  */
376 #define SIT_VBLOCKS_SHIFT	10
377 #define SIT_VBLOCKS_MASK	((1 << SIT_VBLOCKS_SHIFT) - 1)
378 #define GET_SIT_VBLOCKS(raw_sit)				\
379 	(le16_to_cpu((raw_sit)->vblocks) & SIT_VBLOCKS_MASK)
380 #define GET_SIT_TYPE(raw_sit)					\
381 	((le16_to_cpu((raw_sit)->vblocks) & ~SIT_VBLOCKS_MASK)	\
382 	 >> SIT_VBLOCKS_SHIFT)
383 
384 struct f2fs_sit_entry {
385 	__le16 vblocks;				/* reference above */
386 	__u8 valid_map[SIT_VBLOCK_MAP_SIZE];	/* bitmap for valid blocks */
387 	__le64 mtime;				/* segment age for cleaning */
388 } __packed;
389 
390 struct f2fs_sit_block {
391 	struct f2fs_sit_entry entries[SIT_ENTRY_PER_BLOCK];
392 } __packed;
393 
394 /*
395  * For segment summary
396  *
397  * One summary block contains exactly 512 summary entries, which represents
398  * exactly 2MB segment by default. Not allow to change the basic units.
399  *
400  * NOTE: For initializing fields, you must use set_summary
401  *
402  * - If data page, nid represents dnode's nid
403  * - If node page, nid represents the node page's nid.
404  *
405  * The ofs_in_node is used by only data page. It represents offset
406  * from node's page's beginning to get a data block address.
407  * ex) data_blkaddr = (block_t)(nodepage_start_address + ofs_in_node)
408  */
409 #define ENTRIES_IN_SUM		512
410 #define	SUMMARY_SIZE		(7)	/* sizeof(struct summary) */
411 #define	SUM_FOOTER_SIZE		(5)	/* sizeof(struct summary_footer) */
412 #define SUM_ENTRY_SIZE		(SUMMARY_SIZE * ENTRIES_IN_SUM)
413 
414 /* a summary entry for a 4KB-sized block in a segment */
415 struct f2fs_summary {
416 	__le32 nid;		/* parent node id */
417 	union {
418 		__u8 reserved[3];
419 		struct {
420 			__u8 version;		/* node version number */
421 			__le16 ofs_in_node;	/* block index in parent node */
422 		} __packed;
423 	};
424 } __packed;
425 
426 /* summary block type, node or data, is stored to the summary_footer */
427 #define SUM_TYPE_NODE		(1)
428 #define SUM_TYPE_DATA		(0)
429 
430 struct summary_footer {
431 	unsigned char entry_type;	/* SUM_TYPE_XXX */
432 	__le32 check_sum;		/* summary checksum */
433 } __packed;
434 
435 #define SUM_JOURNAL_SIZE	(F2FS_BLKSIZE - SUM_FOOTER_SIZE -\
436 				SUM_ENTRY_SIZE)
437 #define NAT_JOURNAL_ENTRIES	((SUM_JOURNAL_SIZE - 2) /\
438 				sizeof(struct nat_journal_entry))
439 #define NAT_JOURNAL_RESERVED	((SUM_JOURNAL_SIZE - 2) %\
440 				sizeof(struct nat_journal_entry))
441 #define SIT_JOURNAL_ENTRIES	((SUM_JOURNAL_SIZE - 2) /\
442 				sizeof(struct sit_journal_entry))
443 #define SIT_JOURNAL_RESERVED	((SUM_JOURNAL_SIZE - 2) %\
444 				sizeof(struct sit_journal_entry))
445 
446 /* Reserved area should make size of f2fs_extra_info equals to
447  * that of nat_journal and sit_journal.
448  */
449 #define EXTRA_INFO_RESERVED	(SUM_JOURNAL_SIZE - 2 - 8)
450 
451 /*
452  * frequently updated NAT/SIT entries can be stored in the spare area in
453  * summary blocks
454  */
455 enum {
456 	NAT_JOURNAL = 0,
457 	SIT_JOURNAL
458 };
459 
460 struct nat_journal_entry {
461 	__le32 nid;
462 	struct f2fs_nat_entry ne;
463 } __packed;
464 
465 struct nat_journal {
466 	struct nat_journal_entry entries[NAT_JOURNAL_ENTRIES];
467 	__u8 reserved[NAT_JOURNAL_RESERVED];
468 } __packed;
469 
470 struct sit_journal_entry {
471 	__le32 segno;
472 	struct f2fs_sit_entry se;
473 } __packed;
474 
475 struct sit_journal {
476 	struct sit_journal_entry entries[SIT_JOURNAL_ENTRIES];
477 	__u8 reserved[SIT_JOURNAL_RESERVED];
478 } __packed;
479 
480 struct f2fs_extra_info {
481 	__le64 kbytes_written;
482 	__u8 reserved[EXTRA_INFO_RESERVED];
483 } __packed;
484 
485 struct f2fs_journal {
486 	union {
487 		__le16 n_nats;
488 		__le16 n_sits;
489 	};
490 	/* spare area is used by NAT or SIT journals or extra info */
491 	union {
492 		struct nat_journal nat_j;
493 		struct sit_journal sit_j;
494 		struct f2fs_extra_info info;
495 	};
496 } __packed;
497 
498 /* 4KB-sized summary block structure */
499 struct f2fs_summary_block {
500 	struct f2fs_summary entries[ENTRIES_IN_SUM];
501 	struct f2fs_journal journal;
502 	struct summary_footer footer;
503 } __packed;
504 
505 /*
506  * For directory operations
507  */
508 #define F2FS_DOT_HASH		0
509 #define F2FS_DDOT_HASH		F2FS_DOT_HASH
510 #define F2FS_MAX_HASH		(~((0x3ULL) << 62))
511 #define F2FS_HASH_COL_BIT	((0x1ULL) << 63)
512 
513 typedef __le32	f2fs_hash_t;
514 
515 /* One directory entry slot covers 8bytes-long file name */
516 #define F2FS_SLOT_LEN		8
517 #define F2FS_SLOT_LEN_BITS	3
518 
519 #define GET_DENTRY_SLOTS(x) (((x) + F2FS_SLOT_LEN - 1) >> F2FS_SLOT_LEN_BITS)
520 
521 /* MAX level for dir lookup */
522 #define MAX_DIR_HASH_DEPTH	63
523 
524 /* MAX buckets in one level of dir */
525 #define MAX_DIR_BUCKETS		(1 << ((MAX_DIR_HASH_DEPTH / 2) - 1))
526 
527 /*
528  * space utilization of regular dentry and inline dentry (w/o extra reservation)
529  *		regular dentry		inline dentry (def)	inline dentry (min)
530  * bitmap	1 * 27 = 27		1 * 23 = 23		1 * 1 = 1
531  * reserved	1 * 3 = 3		1 * 7 = 7		1 * 1 = 1
532  * dentry	11 * 214 = 2354		11 * 182 = 2002		11 * 2 = 22
533  * filename	8 * 214 = 1712		8 * 182 = 1456		8 * 2 = 16
534  * total	4096			3488			40
535  *
536  * Note: there are more reserved space in inline dentry than in regular
537  * dentry, when converting inline dentry we should handle this carefully.
538  */
539 #define NR_DENTRY_IN_BLOCK	214	/* the number of dentry in a block */
540 #define SIZE_OF_DIR_ENTRY	11	/* by byte */
541 #define SIZE_OF_DENTRY_BITMAP	((NR_DENTRY_IN_BLOCK + BITS_PER_BYTE - 1) / \
542 					BITS_PER_BYTE)
543 #define SIZE_OF_RESERVED	(PAGE_SIZE - ((SIZE_OF_DIR_ENTRY + \
544 				F2FS_SLOT_LEN) * \
545 				NR_DENTRY_IN_BLOCK + SIZE_OF_DENTRY_BITMAP))
546 #define MIN_INLINE_DENTRY_SIZE		40	/* just include '.' and '..' entries */
547 
548 /* One directory entry slot representing F2FS_SLOT_LEN-sized file name */
549 struct f2fs_dir_entry {
550 	__le32 hash_code;	/* hash code of file name */
551 	__le32 ino;		/* inode number */
552 	__le16 name_len;	/* length of file name */
553 	__u8 file_type;		/* file type */
554 } __packed;
555 
556 /* 4KB-sized directory entry block */
557 struct f2fs_dentry_block {
558 	/* validity bitmap for directory entries in each block */
559 	__u8 dentry_bitmap[SIZE_OF_DENTRY_BITMAP];
560 	__u8 reserved[SIZE_OF_RESERVED];
561 	struct f2fs_dir_entry dentry[NR_DENTRY_IN_BLOCK];
562 	__u8 filename[NR_DENTRY_IN_BLOCK][F2FS_SLOT_LEN];
563 } __packed;
564 
565 /* file types used in inode_info->flags */
566 enum {
567 	F2FS_FT_UNKNOWN,
568 	F2FS_FT_REG_FILE,
569 	F2FS_FT_DIR,
570 	F2FS_FT_CHRDEV,
571 	F2FS_FT_BLKDEV,
572 	F2FS_FT_FIFO,
573 	F2FS_FT_SOCK,
574 	F2FS_FT_SYMLINK,
575 	F2FS_FT_MAX
576 };
577 
578 #define S_SHIFT 12
579 
580 #define	F2FS_DEF_PROJID		0	/* default project ID */
581 
582 #endif  /* _LINUX_F2FS_FS_H */
583