xref: /linux/include/linux/f2fs_fs.h (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
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	PAGE_SHIFT	/* Max is Block Size */
17 #define F2FS_LOG_SECTORS_PER_BLOCK	(PAGE_SHIFT - 9) /* log number for sector/blk */
18 #define F2FS_BLKSIZE			PAGE_SIZE /* support only block == page */
19 #define F2FS_BLKSIZE_BITS		PAGE_SHIFT /* 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 #define F2FS_BLK_END_BYTES(blk)		(F2FS_BLK_TO_BYTES(blk + 1) - 1)
31 
32 /* 0, 1(node nid), 2(meta nid) are reserved node id */
33 #define F2FS_RESERVED_NODE_NUM		3
34 
35 #define F2FS_ROOT_INO(sbi)	((sbi)->root_ino_num)
36 #define F2FS_NODE_INO(sbi)	((sbi)->node_ino_num)
37 #define F2FS_META_INO(sbi)	((sbi)->meta_ino_num)
38 #define F2FS_COMPRESS_INO(sbi)	(NM_I(sbi)->max_nid)
39 
40 #define F2FS_MAX_QUOTAS		3
41 
42 #define F2FS_ENC_UTF8_12_1	1
43 
44 /* This flag is used by node and meta inodes, and by recovery */
45 #define GFP_F2FS_ZERO		(GFP_NOFS | __GFP_ZERO)
46 
47 /*
48  * For further optimization on multi-head logs, on-disk layout supports maximum
49  * 16 logs by default. The number, 16, is expected to cover all the cases
50  * enoughly. The implementaion currently uses no more than 6 logs.
51  * Half the logs are used for nodes, and the other half are used for data.
52  */
53 #define MAX_ACTIVE_LOGS	16
54 #define MAX_ACTIVE_NODE_LOGS	8
55 #define MAX_ACTIVE_DATA_LOGS	8
56 
57 #define VERSION_LEN	256
58 #define MAX_VOLUME_NAME		512
59 #define MAX_PATH_LEN		64
60 #define MAX_DEVICES		8
61 
62 /*
63  * For superblock
64  */
65 struct f2fs_device {
66 	__u8 path[MAX_PATH_LEN];
67 	__le32 total_segments;
68 } __packed;
69 
70 /* reason of stop_checkpoint */
71 enum stop_cp_reason {
72 	STOP_CP_REASON_SHUTDOWN,
73 	STOP_CP_REASON_FAULT_INJECT,
74 	STOP_CP_REASON_META_PAGE,
75 	STOP_CP_REASON_WRITE_FAIL,
76 	STOP_CP_REASON_CORRUPTED_SUMMARY,
77 	STOP_CP_REASON_UPDATE_INODE,
78 	STOP_CP_REASON_FLUSH_FAIL,
79 	STOP_CP_REASON_NO_SEGMENT,
80 	STOP_CP_REASON_MAX,
81 };
82 
83 #define	MAX_STOP_REASON			32
84 
85 /* detail reason for EFSCORRUPTED */
86 enum f2fs_error {
87 	ERROR_CORRUPTED_CLUSTER,
88 	ERROR_FAIL_DECOMPRESSION,
89 	ERROR_INVALID_BLKADDR,
90 	ERROR_CORRUPTED_DIRENT,
91 	ERROR_CORRUPTED_INODE,
92 	ERROR_INCONSISTENT_SUMMARY,
93 	ERROR_INCONSISTENT_FOOTER,
94 	ERROR_INCONSISTENT_SUM_TYPE,
95 	ERROR_CORRUPTED_JOURNAL,
96 	ERROR_INCONSISTENT_NODE_COUNT,
97 	ERROR_INCONSISTENT_BLOCK_COUNT,
98 	ERROR_INVALID_CURSEG,
99 	ERROR_INCONSISTENT_SIT,
100 	ERROR_CORRUPTED_VERITY_XATTR,
101 	ERROR_CORRUPTED_XATTR,
102 	ERROR_INVALID_NODE_REFERENCE,
103 	ERROR_INCONSISTENT_NAT,
104 	ERROR_MAX,
105 };
106 
107 #define MAX_F2FS_ERRORS			16
108 
109 struct f2fs_super_block {
110 	__le32 magic;			/* Magic Number */
111 	__le16 major_ver;		/* Major Version */
112 	__le16 minor_ver;		/* Minor Version */
113 	__le32 log_sectorsize;		/* log2 sector size in bytes */
114 	__le32 log_sectors_per_block;	/* log2 # of sectors per block */
115 	__le32 log_blocksize;		/* log2 block size in bytes */
116 	__le32 log_blocks_per_seg;	/* log2 # of blocks per segment */
117 	__le32 segs_per_sec;		/* # of segments per section */
118 	__le32 secs_per_zone;		/* # of sections per zone */
119 	__le32 checksum_offset;		/* checksum offset inside super block */
120 	__le64 block_count;		/* total # of user blocks */
121 	__le32 section_count;		/* total # of sections */
122 	__le32 segment_count;		/* total # of segments */
123 	__le32 segment_count_ckpt;	/* # of segments for checkpoint */
124 	__le32 segment_count_sit;	/* # of segments for SIT */
125 	__le32 segment_count_nat;	/* # of segments for NAT */
126 	__le32 segment_count_ssa;	/* # of segments for SSA */
127 	__le32 segment_count_main;	/* # of segments for main area */
128 	__le32 segment0_blkaddr;	/* start block address of segment 0 */
129 	__le32 cp_blkaddr;		/* start block address of checkpoint */
130 	__le32 sit_blkaddr;		/* start block address of SIT */
131 	__le32 nat_blkaddr;		/* start block address of NAT */
132 	__le32 ssa_blkaddr;		/* start block address of SSA */
133 	__le32 main_blkaddr;		/* start block address of main area */
134 	__le32 root_ino;		/* root inode number */
135 	__le32 node_ino;		/* node inode number */
136 	__le32 meta_ino;		/* meta inode number */
137 	__u8 uuid[16];			/* 128-bit uuid for volume */
138 	__le16 volume_name[MAX_VOLUME_NAME];	/* volume name */
139 	__le32 extension_count;		/* # of extensions below */
140 	__u8 extension_list[F2FS_MAX_EXTENSION][F2FS_EXTENSION_LEN];/* extension array */
141 	__le32 cp_payload;
142 	__u8 version[VERSION_LEN];	/* the kernel version */
143 	__u8 init_version[VERSION_LEN];	/* the initial kernel version */
144 	__le32 feature;			/* defined features */
145 	__u8 encryption_level;		/* versioning level for encryption */
146 	__u8 encrypt_pw_salt[16];	/* Salt used for string2key algorithm */
147 	struct f2fs_device devs[MAX_DEVICES];	/* device list */
148 	__le32 qf_ino[F2FS_MAX_QUOTAS];	/* quota inode numbers */
149 	__u8 hot_ext_count;		/* # of hot file extension */
150 	__le16  s_encoding;		/* Filename charset encoding */
151 	__le16  s_encoding_flags;	/* Filename charset encoding flags */
152 	__u8 s_stop_reason[MAX_STOP_REASON];	/* stop checkpoint reason */
153 	__u8 s_errors[MAX_F2FS_ERRORS];		/* reason of image corrupts */
154 	__u8 reserved[258];		/* valid reserved region */
155 	__le32 crc;			/* checksum of superblock */
156 } __packed;
157 
158 /*
159  * For checkpoint
160  */
161 #define CP_RESIZEFS_FLAG		0x00004000
162 #define CP_DISABLED_QUICK_FLAG		0x00002000
163 #define CP_DISABLED_FLAG		0x00001000
164 #define CP_QUOTA_NEED_FSCK_FLAG		0x00000800
165 #define CP_LARGE_NAT_BITMAP_FLAG	0x00000400
166 #define CP_NOCRC_RECOVERY_FLAG	0x00000200
167 #define CP_TRIMMED_FLAG		0x00000100
168 #define CP_NAT_BITS_FLAG	0x00000080
169 #define CP_CRC_RECOVERY_FLAG	0x00000040
170 #define CP_FASTBOOT_FLAG	0x00000020
171 #define CP_FSCK_FLAG		0x00000010
172 #define CP_ERROR_FLAG		0x00000008
173 #define CP_COMPACT_SUM_FLAG	0x00000004
174 #define CP_ORPHAN_PRESENT_FLAG	0x00000002
175 #define CP_UMOUNT_FLAG		0x00000001
176 
177 #define F2FS_CP_PACKS		2	/* # of checkpoint packs */
178 
179 struct f2fs_checkpoint {
180 	__le64 checkpoint_ver;		/* checkpoint block version number */
181 	__le64 user_block_count;	/* # of user blocks */
182 	__le64 valid_block_count;	/* # of valid blocks in main area */
183 	__le32 rsvd_segment_count;	/* # of reserved segments for gc */
184 	__le32 overprov_segment_count;	/* # of overprovision segments */
185 	__le32 free_segment_count;	/* # of free segments in main area */
186 
187 	/* information of current node segments */
188 	__le32 cur_node_segno[MAX_ACTIVE_NODE_LOGS];
189 	__le16 cur_node_blkoff[MAX_ACTIVE_NODE_LOGS];
190 	/* information of current data segments */
191 	__le32 cur_data_segno[MAX_ACTIVE_DATA_LOGS];
192 	__le16 cur_data_blkoff[MAX_ACTIVE_DATA_LOGS];
193 	__le32 ckpt_flags;		/* Flags : umount and journal_present */
194 	__le32 cp_pack_total_block_count;	/* total # of one cp pack */
195 	__le32 cp_pack_start_sum;	/* start block number of data summary */
196 	__le32 valid_node_count;	/* Total number of valid nodes */
197 	__le32 valid_inode_count;	/* Total number of valid inodes */
198 	__le32 next_free_nid;		/* Next free node number */
199 	__le32 sit_ver_bitmap_bytesize;	/* Default value 64 */
200 	__le32 nat_ver_bitmap_bytesize; /* Default value 256 */
201 	__le32 checksum_offset;		/* checksum offset inside cp block */
202 	__le64 elapsed_time;		/* mounted time */
203 	/* allocation type of current segment */
204 	unsigned char alloc_type[MAX_ACTIVE_LOGS];
205 
206 	/* SIT and NAT version bitmap */
207 	unsigned char sit_nat_version_bitmap[];
208 } __packed;
209 
210 #define CP_CHKSUM_OFFSET	(F2FS_BLKSIZE - sizeof(__le32))	/* default chksum offset in checkpoint */
211 #define CP_MIN_CHKSUM_OFFSET						\
212 	(offsetof(struct f2fs_checkpoint, sit_nat_version_bitmap))
213 
214 /*
215  * For orphan inode management
216  */
217 #define F2FS_ORPHANS_PER_BLOCK	((F2FS_BLKSIZE - 4 * sizeof(__le32)) / sizeof(__le32))
218 
219 #define GET_ORPHAN_BLOCKS(n)	(((n) + F2FS_ORPHANS_PER_BLOCK - 1) / \
220 					F2FS_ORPHANS_PER_BLOCK)
221 
222 struct f2fs_orphan_block {
223 	__le32 ino[F2FS_ORPHANS_PER_BLOCK];	/* inode numbers */
224 	__le32 reserved;	/* reserved */
225 	__le16 blk_addr;	/* block index in current CP */
226 	__le16 blk_count;	/* Number of orphan inode blocks in CP */
227 	__le32 entry_count;	/* Total number of orphan nodes in current CP */
228 	__le32 check_sum;	/* CRC32 for orphan inode block */
229 } __packed;
230 
231 /*
232  * For NODE structure
233  */
234 struct f2fs_extent {
235 	__le32 fofs;		/* start file offset of the extent */
236 	__le32 blk;		/* start block address of the extent */
237 	__le32 len;		/* length of the extent */
238 } __packed;
239 
240 #define F2FS_NAME_LEN		255
241 /* 200 bytes for inline xattrs by default */
242 #define DEFAULT_INLINE_XATTR_ADDRS	50
243 
244 #define OFFSET_OF_END_OF_I_EXT		360
245 #define SIZE_OF_I_NID			20
246 
247 struct node_footer {
248 	__le32 nid;		/* node id */
249 	__le32 ino;		/* inode number */
250 	__le32 flag;		/* include cold/fsync/dentry marks and offset */
251 	__le64 cp_ver;		/* checkpoint version */
252 	__le32 next_blkaddr;	/* next node page block address */
253 } __packed;
254 
255 /* Address Pointers in an Inode */
256 #define DEF_ADDRS_PER_INODE	((F2FS_BLKSIZE - OFFSET_OF_END_OF_I_EXT	\
257 					- SIZE_OF_I_NID	\
258 					- sizeof(struct node_footer)) / sizeof(__le32))
259 #define CUR_ADDRS_PER_INODE(inode)	(DEF_ADDRS_PER_INODE - \
260 					get_extra_isize(inode))
261 #define DEF_NIDS_PER_INODE	5	/* Node IDs in an Inode */
262 #define ADDRS_PER_INODE(inode)	addrs_per_inode(inode)
263 /* Address Pointers in a Direct Block */
264 #define DEF_ADDRS_PER_BLOCK	((F2FS_BLKSIZE - sizeof(struct node_footer)) / sizeof(__le32))
265 #define ADDRS_PER_BLOCK(inode)	addrs_per_block(inode)
266 /* Node IDs in an Indirect Block */
267 #define NIDS_PER_BLOCK		((F2FS_BLKSIZE - sizeof(struct node_footer)) / sizeof(__le32))
268 
269 #define ADDRS_PER_PAGE(page, inode)	\
270 	(IS_INODE(page) ? ADDRS_PER_INODE(inode) : ADDRS_PER_BLOCK(inode))
271 
272 #define	NODE_DIR1_BLOCK		(DEF_ADDRS_PER_INODE + 1)
273 #define	NODE_DIR2_BLOCK		(DEF_ADDRS_PER_INODE + 2)
274 #define	NODE_IND1_BLOCK		(DEF_ADDRS_PER_INODE + 3)
275 #define	NODE_IND2_BLOCK		(DEF_ADDRS_PER_INODE + 4)
276 #define	NODE_DIND_BLOCK		(DEF_ADDRS_PER_INODE + 5)
277 
278 #define F2FS_INLINE_XATTR	0x01	/* file inline xattr flag */
279 #define F2FS_INLINE_DATA	0x02	/* file inline data flag */
280 #define F2FS_INLINE_DENTRY	0x04	/* file inline dentry flag */
281 #define F2FS_DATA_EXIST		0x08	/* file inline data exist flag */
282 #define F2FS_INLINE_DOTS	0x10	/* file having implicit dot dentries */
283 #define F2FS_EXTRA_ATTR		0x20	/* file having extra attribute */
284 #define F2FS_PIN_FILE		0x40	/* file should not be gced */
285 #define F2FS_COMPRESS_RELEASED	0x80	/* file released compressed blocks */
286 
287 struct f2fs_inode {
288 	__le16 i_mode;			/* file mode */
289 	__u8 i_advise;			/* file hints */
290 	__u8 i_inline;			/* file inline flags */
291 	__le32 i_uid;			/* user ID */
292 	__le32 i_gid;			/* group ID */
293 	__le32 i_links;			/* links count */
294 	__le64 i_size;			/* file size in bytes */
295 	__le64 i_blocks;		/* file size in blocks */
296 	__le64 i_atime;			/* access time */
297 	__le64 i_ctime;			/* change time */
298 	__le64 i_mtime;			/* modification time */
299 	__le32 i_atime_nsec;		/* access time in nano scale */
300 	__le32 i_ctime_nsec;		/* change time in nano scale */
301 	__le32 i_mtime_nsec;		/* modification time in nano scale */
302 	__le32 i_generation;		/* file version (for NFS) */
303 	union {
304 		__le32 i_current_depth;	/* only for directory depth */
305 		__le16 i_gc_failures;	/*
306 					 * # of gc failures on pinned file.
307 					 * only for regular files.
308 					 */
309 	};
310 	__le32 i_xattr_nid;		/* nid to save xattr */
311 	__le32 i_flags;			/* file attributes */
312 	__le32 i_pino;			/* parent inode number */
313 	__le32 i_namelen;		/* file name length */
314 	__u8 i_name[F2FS_NAME_LEN];	/* file name for SPOR */
315 	__u8 i_dir_level;		/* dentry_level for large dir */
316 
317 	struct f2fs_extent i_ext;	/* caching a largest extent */
318 
319 	union {
320 		struct {
321 			__le16 i_extra_isize;	/* extra inode attribute size */
322 			__le16 i_inline_xattr_size;	/* inline xattr size, unit: 4 bytes */
323 			__le32 i_projid;	/* project id */
324 			__le32 i_inode_checksum;/* inode meta checksum */
325 			__le64 i_crtime;	/* creation time */
326 			__le32 i_crtime_nsec;	/* creation time in nano scale */
327 			__le64 i_compr_blocks;	/* # of compressed blocks */
328 			__u8 i_compress_algorithm;	/* compress algorithm */
329 			__u8 i_log_cluster_size;	/* log of cluster size */
330 			__le16 i_compress_flag;		/* compress flag */
331 						/* 0 bit: chksum flag
332 						 * [8,15] bits: compress level
333 						 */
334 			__le32 i_extra_end[0];	/* for attribute size calculation */
335 		} __packed;
336 		__le32 i_addr[DEF_ADDRS_PER_INODE];	/* Pointers to data blocks */
337 	};
338 	__le32 i_nid[DEF_NIDS_PER_INODE];	/* direct(2), indirect(2),
339 						double_indirect(1) node id */
340 } __packed;
341 
342 struct direct_node {
343 	__le32 addr[DEF_ADDRS_PER_BLOCK];	/* array of data block address */
344 } __packed;
345 
346 struct indirect_node {
347 	__le32 nid[NIDS_PER_BLOCK];	/* array of data block address */
348 } __packed;
349 
350 enum {
351 	COLD_BIT_SHIFT = 0,
352 	FSYNC_BIT_SHIFT,
353 	DENT_BIT_SHIFT,
354 	OFFSET_BIT_SHIFT
355 };
356 
357 #define OFFSET_BIT_MASK		GENMASK(OFFSET_BIT_SHIFT - 1, 0)
358 
359 struct f2fs_node {
360 	/* can be one of three types: inode, direct, and indirect types */
361 	union {
362 		struct f2fs_inode i;
363 		struct direct_node dn;
364 		struct indirect_node in;
365 	};
366 	struct node_footer footer;
367 } __packed;
368 
369 /*
370  * For NAT entries
371  */
372 #define NAT_ENTRY_PER_BLOCK (F2FS_BLKSIZE / sizeof(struct f2fs_nat_entry))
373 
374 struct f2fs_nat_entry {
375 	__u8 version;		/* latest version of cached nat entry */
376 	__le32 ino;		/* inode number */
377 	__le32 block_addr;	/* block address */
378 } __packed;
379 
380 struct f2fs_nat_block {
381 	struct f2fs_nat_entry entries[NAT_ENTRY_PER_BLOCK];
382 } __packed;
383 
384 /*
385  * For SIT entries
386  *
387  * A validity bitmap of 64 bytes covers 512 blocks of area. For a 4K page size,
388  * this results in a segment size of 2MB. For 16k pages, the default segment size
389  * is 8MB.
390  * Not allow to change this.
391  */
392 #define SIT_VBLOCK_MAP_SIZE 64
393 #define SIT_ENTRY_PER_BLOCK (F2FS_BLKSIZE / sizeof(struct f2fs_sit_entry))
394 
395 /*
396  * F2FS uses 4 bytes to represent block address. As a result, supported size of
397  * disk is 16 TB and it equals to 16 * 1024 * 1024 / 2 segments.
398  */
399 #define F2FS_MAX_SEGMENT       ((16 * 1024 * 1024) / 2)
400 
401 /*
402  * Note that f2fs_sit_entry->vblocks has the following bit-field information.
403  * [15:10] : allocation type such as CURSEG_XXXX_TYPE
404  * [9:0] : valid block count
405  */
406 #define SIT_VBLOCKS_SHIFT	10
407 #define SIT_VBLOCKS_MASK	((1 << SIT_VBLOCKS_SHIFT) - 1)
408 #define GET_SIT_VBLOCKS(raw_sit)				\
409 	(le16_to_cpu((raw_sit)->vblocks) & SIT_VBLOCKS_MASK)
410 #define GET_SIT_TYPE(raw_sit)					\
411 	((le16_to_cpu((raw_sit)->vblocks) & ~SIT_VBLOCKS_MASK)	\
412 	 >> SIT_VBLOCKS_SHIFT)
413 
414 struct f2fs_sit_entry {
415 	__le16 vblocks;				/* reference above */
416 	__u8 valid_map[SIT_VBLOCK_MAP_SIZE];	/* bitmap for valid blocks */
417 	__le64 mtime;				/* segment age for cleaning */
418 } __packed;
419 
420 struct f2fs_sit_block {
421 	struct f2fs_sit_entry entries[SIT_ENTRY_PER_BLOCK];
422 } __packed;
423 
424 /*
425  * For segment summary
426  *
427  * One summary block contains exactly 512 summary entries, which represents
428  * exactly one segment by default. Not allow to change the basic units.
429  *
430  * NOTE: For initializing fields, you must use set_summary
431  *
432  * - If data page, nid represents dnode's nid
433  * - If node page, nid represents the node page's nid.
434  *
435  * The ofs_in_node is used by only data page. It represents offset
436  * from node's page's beginning to get a data block address.
437  * ex) data_blkaddr = (block_t)(nodepage_start_address + ofs_in_node)
438  */
439 #define ENTRIES_IN_SUM		(F2FS_BLKSIZE / 8)
440 #define	SUMMARY_SIZE		(7)	/* sizeof(struct f2fs_summary) */
441 #define	SUM_FOOTER_SIZE		(5)	/* sizeof(struct summary_footer) */
442 #define SUM_ENTRY_SIZE		(SUMMARY_SIZE * ENTRIES_IN_SUM)
443 
444 /* a summary entry for a block in a segment */
445 struct f2fs_summary {
446 	__le32 nid;		/* parent node id */
447 	union {
448 		__u8 reserved[3];
449 		struct {
450 			__u8 version;		/* node version number */
451 			__le16 ofs_in_node;	/* block index in parent node */
452 		} __packed;
453 	};
454 } __packed;
455 
456 /* summary block type, node or data, is stored to the summary_footer */
457 #define SUM_TYPE_NODE		(1)
458 #define SUM_TYPE_DATA		(0)
459 
460 struct summary_footer {
461 	unsigned char entry_type;	/* SUM_TYPE_XXX */
462 	__le32 check_sum;		/* summary checksum */
463 } __packed;
464 
465 #define SUM_JOURNAL_SIZE	(F2FS_BLKSIZE - SUM_FOOTER_SIZE -\
466 				SUM_ENTRY_SIZE)
467 #define NAT_JOURNAL_ENTRIES	((SUM_JOURNAL_SIZE - 2) /\
468 				sizeof(struct nat_journal_entry))
469 #define NAT_JOURNAL_RESERVED	((SUM_JOURNAL_SIZE - 2) %\
470 				sizeof(struct nat_journal_entry))
471 #define SIT_JOURNAL_ENTRIES	((SUM_JOURNAL_SIZE - 2) /\
472 				sizeof(struct sit_journal_entry))
473 #define SIT_JOURNAL_RESERVED	((SUM_JOURNAL_SIZE - 2) %\
474 				sizeof(struct sit_journal_entry))
475 
476 /* Reserved area should make size of f2fs_extra_info equals to
477  * that of nat_journal and sit_journal.
478  */
479 #define EXTRA_INFO_RESERVED	(SUM_JOURNAL_SIZE - 2 - 8)
480 
481 /*
482  * frequently updated NAT/SIT entries can be stored in the spare area in
483  * summary blocks
484  */
485 enum {
486 	NAT_JOURNAL = 0,
487 	SIT_JOURNAL
488 };
489 
490 struct nat_journal_entry {
491 	__le32 nid;
492 	struct f2fs_nat_entry ne;
493 } __packed;
494 
495 struct nat_journal {
496 	struct nat_journal_entry entries[NAT_JOURNAL_ENTRIES];
497 	__u8 reserved[NAT_JOURNAL_RESERVED];
498 } __packed;
499 
500 struct sit_journal_entry {
501 	__le32 segno;
502 	struct f2fs_sit_entry se;
503 } __packed;
504 
505 struct sit_journal {
506 	struct sit_journal_entry entries[SIT_JOURNAL_ENTRIES];
507 	__u8 reserved[SIT_JOURNAL_RESERVED];
508 } __packed;
509 
510 struct f2fs_extra_info {
511 	__le64 kbytes_written;
512 	__u8 reserved[EXTRA_INFO_RESERVED];
513 } __packed;
514 
515 struct f2fs_journal {
516 	union {
517 		__le16 n_nats;
518 		__le16 n_sits;
519 	};
520 	/* spare area is used by NAT or SIT journals or extra info */
521 	union {
522 		struct nat_journal nat_j;
523 		struct sit_journal sit_j;
524 		struct f2fs_extra_info info;
525 	};
526 } __packed;
527 
528 /* Block-sized summary block structure */
529 struct f2fs_summary_block {
530 	struct f2fs_summary entries[ENTRIES_IN_SUM];
531 	struct f2fs_journal journal;
532 	struct summary_footer footer;
533 } __packed;
534 
535 /*
536  * For directory operations
537  */
538 #define F2FS_DOT_HASH		0
539 #define F2FS_DDOT_HASH		F2FS_DOT_HASH
540 #define F2FS_MAX_HASH		(~((0x3ULL) << 62))
541 #define F2FS_HASH_COL_BIT	((0x1ULL) << 63)
542 
543 typedef __le32	f2fs_hash_t;
544 
545 /* One directory entry slot covers 8bytes-long file name */
546 #define F2FS_SLOT_LEN		8
547 #define F2FS_SLOT_LEN_BITS	3
548 
549 #define GET_DENTRY_SLOTS(x) (((x) + F2FS_SLOT_LEN - 1) >> F2FS_SLOT_LEN_BITS)
550 
551 /* MAX level for dir lookup */
552 #define MAX_DIR_HASH_DEPTH	63
553 
554 /* MAX buckets in one level of dir */
555 #define MAX_DIR_BUCKETS		BIT((MAX_DIR_HASH_DEPTH / 2) - 1)
556 
557 /*
558  * space utilization of regular dentry and inline dentry (w/o extra reservation)
559  *		regular dentry		inline dentry (def)	inline dentry (min)
560  * bitmap	1 * 27 = 27		1 * 23 = 23		1 * 1 = 1
561  * reserved	1 * 3 = 3		1 * 7 = 7		1 * 1 = 1
562  * dentry	11 * 214 = 2354		11 * 182 = 2002		11 * 2 = 22
563  * filename	8 * 214 = 1712		8 * 182 = 1456		8 * 2 = 16
564  * total	4096			3488			40
565  *
566  * Note: there are more reserved space in inline dentry than in regular
567  * dentry, when converting inline dentry we should handle this carefully.
568  */
569 
570 /* the number of dentry in a block */
571 #define NR_DENTRY_IN_BLOCK	((BITS_PER_BYTE * F2FS_BLKSIZE) / \
572 					((SIZE_OF_DIR_ENTRY + F2FS_SLOT_LEN) * BITS_PER_BYTE + 1))
573 #define SIZE_OF_DIR_ENTRY	11	/* by byte */
574 #define SIZE_OF_DENTRY_BITMAP	((NR_DENTRY_IN_BLOCK + BITS_PER_BYTE - 1) / \
575 					BITS_PER_BYTE)
576 #define SIZE_OF_RESERVED	(F2FS_BLKSIZE - ((SIZE_OF_DIR_ENTRY + \
577 				F2FS_SLOT_LEN) * \
578 				NR_DENTRY_IN_BLOCK + SIZE_OF_DENTRY_BITMAP))
579 #define MIN_INLINE_DENTRY_SIZE		40	/* just include '.' and '..' entries */
580 
581 /* One directory entry slot representing F2FS_SLOT_LEN-sized file name */
582 struct f2fs_dir_entry {
583 	__le32 hash_code;	/* hash code of file name */
584 	__le32 ino;		/* inode number */
585 	__le16 name_len;	/* length of file name */
586 	__u8 file_type;		/* file type */
587 } __packed;
588 
589 /* Block-sized directory entry block */
590 struct f2fs_dentry_block {
591 	/* validity bitmap for directory entries in each block */
592 	__u8 dentry_bitmap[SIZE_OF_DENTRY_BITMAP];
593 	__u8 reserved[SIZE_OF_RESERVED];
594 	struct f2fs_dir_entry dentry[NR_DENTRY_IN_BLOCK];
595 	__u8 filename[NR_DENTRY_IN_BLOCK][F2FS_SLOT_LEN];
596 } __packed;
597 
598 #define	F2FS_DEF_PROJID		0	/* default project ID */
599 
600 #endif  /* _LINUX_F2FS_FS_H */
601