f2fs_fs.h

  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
 23#define NULL_ADDR		((block_t)0)	/* used as block_t addresses */
 24#define NEW_ADDR		((block_t)-1)	/* used as block_t addresses */
 25#define COMPRESS_ADDR		((block_t)-2)	/* used as compressed data flag */
 26
 27#define F2FS_BLKSIZE_MASK		(F2FS_BLKSIZE - 1)
 28#define F2FS_BYTES_TO_BLK(bytes)	((unsigned long long)(bytes) >> F2FS_BLKSIZE_BITS)
 29#define F2FS_BLK_TO_BYTES(blk)		((unsigned long long)(blk) << F2FS_BLKSIZE_BITS)
 30#define F2FS_BLK_END_BYTES(blk)		(F2FS_BLK_TO_BYTES(blk + 1) - 1)
 31#define F2FS_BLK_ALIGN(x)		(F2FS_BYTES_TO_BLK((x) + F2FS_BLKSIZE - 1))
 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#define F2FS_COMPRESS_INO(sbi)	(NM_I(sbi)->max_nid)
 40
 41#define F2FS_MAX_QUOTAS		3
 42
 43#define F2FS_ENC_UTF8_12_1	1
 44
 45/* This flag is used by node and meta inodes, and by recovery */
 46#define GFP_F2FS_ZERO		(GFP_NOFS | __GFP_ZERO)
 47
 48/*
 49 * For further optimization on multi-head logs, on-disk layout supports maximum
 50 * 16 logs by default. The number, 16, is expected to cover all the cases
 51 * enoughly. The implementaion currently uses no more than 6 logs.
 52 * Half the logs are used for nodes, and the other half are used for data.
 53 */
 54#define MAX_ACTIVE_LOGS	16
 55#define MAX_ACTIVE_NODE_LOGS	8
 56#define MAX_ACTIVE_DATA_LOGS	8
 57
 58#define VERSION_LEN	256
 59#define MAX_VOLUME_NAME		512
 60#define MAX_PATH_LEN		64
 61#define MAX_DEVICES		8
 62
 63/*
 64 * For superblock
 65 */
 66struct f2fs_device {
 67	__u8 path[MAX_PATH_LEN];
 68	__le32 total_segments;
 69} __packed;
 70
 71/* reason of stop_checkpoint */
 72enum stop_cp_reason {
 73	STOP_CP_REASON_SHUTDOWN,
 74	STOP_CP_REASON_FAULT_INJECT,
 75	STOP_CP_REASON_META_PAGE,
 76	STOP_CP_REASON_WRITE_FAIL,
 77	STOP_CP_REASON_CORRUPTED_SUMMARY,
 78	STOP_CP_REASON_UPDATE_INODE,
 79	STOP_CP_REASON_FLUSH_FAIL,
 80	STOP_CP_REASON_NO_SEGMENT,
 81	STOP_CP_REASON_CORRUPTED_FREE_BITMAP,
 82	STOP_CP_REASON_CORRUPTED_NID,
 83	STOP_CP_REASON_MAX,
 84};
 85
 86#define	MAX_STOP_REASON			32
 87
 88/* detail reason for EFSCORRUPTED */
 89enum f2fs_error {
 90	ERROR_CORRUPTED_CLUSTER,
 91	ERROR_FAIL_DECOMPRESSION,
 92	ERROR_INVALID_BLKADDR,
 93	ERROR_CORRUPTED_DIRENT,
 94	ERROR_CORRUPTED_INODE,
 95	ERROR_INCONSISTENT_SUMMARY,
 96	ERROR_INCONSISTENT_FOOTER,
 97	ERROR_INCONSISTENT_SUM_TYPE,
 98	ERROR_CORRUPTED_JOURNAL,
 99	ERROR_INCONSISTENT_NODE_COUNT,
100	ERROR_INCONSISTENT_BLOCK_COUNT,
101	ERROR_INVALID_CURSEG,
102	ERROR_INCONSISTENT_SIT,
103	ERROR_CORRUPTED_VERITY_XATTR,
104	ERROR_CORRUPTED_XATTR,
105	ERROR_INVALID_NODE_REFERENCE,
106	ERROR_INCONSISTENT_NAT,
107	ERROR_MAX,
108};
109
110#define MAX_F2FS_ERRORS			16
111
112struct f2fs_super_block {
113	__le32 magic;			/* Magic Number */
114	__le16 major_ver;		/* Major Version */
115	__le16 minor_ver;		/* Minor Version */
116	__le32 log_sectorsize;		/* log2 sector size in bytes */
117	__le32 log_sectors_per_block;	/* log2 # of sectors per block */
118	__le32 log_blocksize;		/* log2 block size in bytes */
119	__le32 log_blocks_per_seg;	/* log2 # of blocks per segment */
120	__le32 segs_per_sec;		/* # of segments per section */
121	__le32 secs_per_zone;		/* # of sections per zone */
122	__le32 checksum_offset;		/* checksum offset inside super block */
123	__le64 block_count;		/* total # of user blocks */
124	__le32 section_count;		/* total # of sections */
125	__le32 segment_count;		/* total # of segments */
126	__le32 segment_count_ckpt;	/* # of segments for checkpoint */
127	__le32 segment_count_sit;	/* # of segments for SIT */
128	__le32 segment_count_nat;	/* # of segments for NAT */
129	__le32 segment_count_ssa;	/* # of segments for SSA */
130	__le32 segment_count_main;	/* # of segments for main area */
131	__le32 segment0_blkaddr;	/* start block address of segment 0 */
132	__le32 cp_blkaddr;		/* start block address of checkpoint */
133	__le32 sit_blkaddr;		/* start block address of SIT */
134	__le32 nat_blkaddr;		/* start block address of NAT */
135	__le32 ssa_blkaddr;		/* start block address of SSA */
136	__le32 main_blkaddr;		/* start block address of main area */
137	__le32 root_ino;		/* root inode number */
138	__le32 node_ino;		/* node inode number */
139	__le32 meta_ino;		/* meta inode number */
140	__u8 uuid[16];			/* 128-bit uuid for volume */
141	__le16 volume_name[MAX_VOLUME_NAME];	/* volume name */
142	__le32 extension_count;		/* # of extensions below */
143	__u8 extension_list[F2FS_MAX_EXTENSION][F2FS_EXTENSION_LEN];/* extension array */
144	__le32 cp_payload;
145	__u8 version[VERSION_LEN];	/* the kernel version */
146	__u8 init_version[VERSION_LEN];	/* the initial kernel version */
147	__le32 feature;			/* defined features */
148	__u8 encryption_level;		/* versioning level for encryption */
149	__u8 encrypt_pw_salt[16];	/* Salt used for string2key algorithm */
150	struct f2fs_device devs[MAX_DEVICES];	/* device list */
151	__le32 qf_ino[F2FS_MAX_QUOTAS];	/* quota inode numbers */
152	__u8 hot_ext_count;		/* # of hot file extension */
153	__le16  s_encoding;		/* Filename charset encoding */
154	__le16  s_encoding_flags;	/* Filename charset encoding flags */
155	__u8 s_stop_reason[MAX_STOP_REASON];	/* stop checkpoint reason */
156	__u8 s_errors[MAX_F2FS_ERRORS];		/* reason of image corrupts */
157	__u8 reserved[258];		/* valid reserved region */
158	__le32 crc;			/* checksum of superblock */
159} __packed;
160
161/*
162 * For checkpoint
163 */
164#define CP_RESIZEFS_FLAG		0x00004000
165#define CP_DISABLED_QUICK_FLAG		0x00002000
166#define CP_DISABLED_FLAG		0x00001000
167#define CP_QUOTA_NEED_FSCK_FLAG		0x00000800
168#define CP_LARGE_NAT_BITMAP_FLAG	0x00000400
169#define CP_NOCRC_RECOVERY_FLAG	0x00000200
170#define CP_TRIMMED_FLAG		0x00000100
171#define CP_NAT_BITS_FLAG	0x00000080
172#define CP_CRC_RECOVERY_FLAG	0x00000040
173#define CP_FASTBOOT_FLAG	0x00000020
174#define CP_FSCK_FLAG		0x00000010
175#define CP_ERROR_FLAG		0x00000008
176#define CP_COMPACT_SUM_FLAG	0x00000004
177#define CP_ORPHAN_PRESENT_FLAG	0x00000002
178#define CP_UMOUNT_FLAG		0x00000001
179
180#define F2FS_CP_PACKS		2	/* # of checkpoint packs */
181
182struct f2fs_checkpoint {
183	__le64 checkpoint_ver;		/* checkpoint block version number */
184	__le64 user_block_count;	/* # of user blocks */
185	__le64 valid_block_count;	/* # of valid blocks in main area */
186	__le32 rsvd_segment_count;	/* # of reserved segments for gc */
187	__le32 overprov_segment_count;	/* # of overprovision segments */
188	__le32 free_segment_count;	/* # of free segments in main area */
189
190	/* information of current node segments */
191	__le32 cur_node_segno[MAX_ACTIVE_NODE_LOGS];
192	__le16 cur_node_blkoff[MAX_ACTIVE_NODE_LOGS];
193	/* information of current data segments */
194	__le32 cur_data_segno[MAX_ACTIVE_DATA_LOGS];
195	__le16 cur_data_blkoff[MAX_ACTIVE_DATA_LOGS];
196	__le32 ckpt_flags;		/* Flags : umount and journal_present */
197	__le32 cp_pack_total_block_count;	/* total # of one cp pack */
198	__le32 cp_pack_start_sum;	/* start block number of data summary */
199	__le32 valid_node_count;	/* Total number of valid nodes */
200	__le32 valid_inode_count;	/* Total number of valid inodes */
201	__le32 next_free_nid;		/* Next free node number */
202	__le32 sit_ver_bitmap_bytesize;	/* Default value 64 */
203	__le32 nat_ver_bitmap_bytesize; /* Default value 256 */
204	__le32 checksum_offset;		/* checksum offset inside cp block */
205	__le64 elapsed_time;		/* mounted time */
206	/* allocation type of current segment */
207	unsigned char alloc_type[MAX_ACTIVE_LOGS];
208
209	/* SIT and NAT version bitmap */
210	unsigned char sit_nat_version_bitmap[];
211} __packed;
212
213#define CP_CHKSUM_OFFSET	(F2FS_BLKSIZE - sizeof(__le32))	/* default chksum offset in checkpoint */
214#define CP_MIN_CHKSUM_OFFSET						\
215	(offsetof(struct f2fs_checkpoint, sit_nat_version_bitmap))
216
217/*
218 * For orphan inode management
219 */
220#define F2FS_ORPHANS_PER_BLOCK	((F2FS_BLKSIZE - 4 * sizeof(__le32)) / sizeof(__le32))
221
222#define GET_ORPHAN_BLOCKS(n)	(((n) + F2FS_ORPHANS_PER_BLOCK - 1) / \
223					F2FS_ORPHANS_PER_BLOCK)
224
225struct f2fs_orphan_block {
226	__le32 ino[F2FS_ORPHANS_PER_BLOCK];	/* inode numbers */
227	__le32 reserved;	/* reserved */
228	__le16 blk_addr;	/* block index in current CP */
229	__le16 blk_count;	/* Number of orphan inode blocks in CP */
230	__le32 entry_count;	/* Total number of orphan nodes in current CP */
231	__le32 check_sum;	/* CRC32 for orphan inode block */
232} __packed;
233
234/*
235 * For NODE structure
236 */
237struct f2fs_extent {
238	__le32 fofs;		/* start file offset of the extent */
239	__le32 blk;		/* start block address of the extent */
240	__le32 len;		/* length of the extent */
241} __packed;
242
243#define F2FS_NAME_LEN		255
244/* 200 bytes for inline xattrs by default */
245#define DEFAULT_INLINE_XATTR_ADDRS	50
246
247#define OFFSET_OF_END_OF_I_EXT		360
248#define SIZE_OF_I_NID			20
249
250struct node_footer {
251	__le32 nid;		/* node id */
252	__le32 ino;		/* inode number */
253	__le32 flag;		/* include cold/fsync/dentry marks and offset */
254	__le64 cp_ver;		/* checkpoint version */
255	__le32 next_blkaddr;	/* next node page block address */
256} __packed;
257
258/* Address Pointers in an Inode */
259#define DEF_ADDRS_PER_INODE	((F2FS_BLKSIZE - OFFSET_OF_END_OF_I_EXT	\
260					- SIZE_OF_I_NID	\
261					- sizeof(struct node_footer)) / sizeof(__le32))
262#define CUR_ADDRS_PER_INODE(inode)	(DEF_ADDRS_PER_INODE - \
263					get_extra_isize(inode))
264#define DEF_NIDS_PER_INODE	5	/* Node IDs in an Inode */
265#define ADDRS_PER_INODE(inode)	addrs_per_page(inode, true)
266/* Address Pointers in a Direct Block */
267#define DEF_ADDRS_PER_BLOCK	((F2FS_BLKSIZE - sizeof(struct node_footer)) / sizeof(__le32))
268#define ADDRS_PER_BLOCK(inode)	addrs_per_page(inode, false)
269/* Node IDs in an Indirect Block */
270#define NIDS_PER_BLOCK		((F2FS_BLKSIZE - sizeof(struct node_footer)) / sizeof(__le32))
271
272#define ADDRS_PER_PAGE(folio, inode)	(addrs_per_page(inode, IS_INODE(folio)))
273
274#define	NODE_DIR1_BLOCK		(DEF_ADDRS_PER_INODE + 1)
275#define	NODE_DIR2_BLOCK		(DEF_ADDRS_PER_INODE + 2)
276#define	NODE_IND1_BLOCK		(DEF_ADDRS_PER_INODE + 3)
277#define	NODE_IND2_BLOCK		(DEF_ADDRS_PER_INODE + 4)
278#define	NODE_DIND_BLOCK		(DEF_ADDRS_PER_INODE + 5)
279
280#define F2FS_INLINE_XATTR	0x01	/* file inline xattr flag */
281#define F2FS_INLINE_DATA	0x02	/* file inline data flag */
282#define F2FS_INLINE_DENTRY	0x04	/* file inline dentry flag */
283#define F2FS_DATA_EXIST		0x08	/* file inline data exist flag */
284#define F2FS_INLINE_DOTS	0x10	/* file having implicit dot dentries (obsolete) */
285#define F2FS_EXTRA_ATTR		0x20	/* file having extra attribute */
286#define F2FS_PIN_FILE		0x40	/* file should not be gced */
287#define F2FS_COMPRESS_RELEASED	0x80	/* file released compressed blocks */
288
289struct f2fs_inode {
290	__le16 i_mode;			/* file mode */
291	__u8 i_advise;			/* file hints */
292	__u8 i_inline;			/* file inline flags */
293	__le32 i_uid;			/* user ID */
294	__le32 i_gid;			/* group ID */
295	__le32 i_links;			/* links count */
296	__le64 i_size;			/* file size in bytes */
297	__le64 i_blocks;		/* file size in blocks */
298	__le64 i_atime;			/* access time */
299	__le64 i_ctime;			/* change time */
300	__le64 i_mtime;			/* modification time */
301	__le32 i_atime_nsec;		/* access time in nano scale */
302	__le32 i_ctime_nsec;		/* change time in nano scale */
303	__le32 i_mtime_nsec;		/* modification time in nano scale */
304	__le32 i_generation;		/* file version (for NFS) */
305	union {
306		__le32 i_current_depth;	/* only for directory depth */
307		__le16 i_gc_failures;	/*
308					 * # of gc failures on pinned file.
309					 * only for regular files.
310					 */
311	};
312	__le32 i_xattr_nid;		/* nid to save xattr */
313	__le32 i_flags;			/* file attributes */
314	__le32 i_pino;			/* parent inode number */
315	__le32 i_namelen;		/* file name length */
316	__u8 i_name[F2FS_NAME_LEN];	/* file name for SPOR */
317	__u8 i_dir_level;		/* dentry_level for large dir */
318
319	struct f2fs_extent i_ext;	/* caching a largest extent */
320
321	union {
322		struct {
323			__le16 i_extra_isize;	/* extra inode attribute size */
324			__le16 i_inline_xattr_size;	/* inline xattr size, unit: 4 bytes */
325			__le32 i_projid;	/* project id */
326			__le32 i_inode_checksum;/* inode meta checksum */
327			__le64 i_crtime;	/* creation time */
328			__le32 i_crtime_nsec;	/* creation time in nano scale */
329			__le64 i_compr_blocks;	/* # of compressed blocks */
330			__u8 i_compress_algorithm;	/* compress algorithm */
331			__u8 i_log_cluster_size;	/* log of cluster size */
332			__le16 i_compress_flag;		/* compress flag */
333						/* 0 bit: chksum flag
334						 * [8,15] bits: compress level
335						 */
336			__le32 i_extra_end[0];	/* for attribute size calculation */
337		} __packed;
338		__le32 i_addr[DEF_ADDRS_PER_INODE];	/* Pointers to data blocks */
339	};
340	__le32 i_nid[DEF_NIDS_PER_INODE];	/* direct(2), indirect(2),
341						double_indirect(1) node id */
342} __packed;
343
344struct direct_node {
345	__le32 addr[DEF_ADDRS_PER_BLOCK];	/* array of data block address */
346} __packed;
347
348struct indirect_node {
349	__le32 nid[NIDS_PER_BLOCK];	/* array of data block address */
350} __packed;
351
352enum {
353	COLD_BIT_SHIFT = 0,
354	FSYNC_BIT_SHIFT,
355	DENT_BIT_SHIFT,
356	OFFSET_BIT_SHIFT
357};
358
359#define OFFSET_BIT_MASK		GENMASK(OFFSET_BIT_SHIFT - 1, 0)
360
361struct f2fs_node {
362	/* can be one of three types: inode, direct, and indirect types */
363	union {
364		struct f2fs_inode i;
365		struct direct_node dn;
366		struct indirect_node in;
367	};
368	struct node_footer footer;
369} __packed;
370
371/*
372 * For NAT entries
373 */
374#define NAT_ENTRY_PER_BLOCK (F2FS_BLKSIZE / sizeof(struct f2fs_nat_entry))
375
376struct f2fs_nat_entry {
377	__u8 version;		/* latest version of cached nat entry */
378	__le32 ino;		/* inode number */
379	__le32 block_addr;	/* block address */
380} __packed;
381
382struct f2fs_nat_block {
383	struct f2fs_nat_entry entries[NAT_ENTRY_PER_BLOCK];
384} __packed;
385
386/*
387 * For SIT entries
388 *
389 * A validity bitmap of 64 bytes covers 512 blocks of area. For a 4K page size,
390 * this results in a segment size of 2MB. For 16k pages, the default segment size
391 * is 8MB.
392 * Not allow to change this.
393 */
394#define SIT_VBLOCK_MAP_SIZE 64
395#define SIT_ENTRY_PER_BLOCK (F2FS_BLKSIZE / sizeof(struct f2fs_sit_entry))
396
397/*
398 * F2FS uses 4 bytes to represent block address. As a result, supported size of
399 * disk is 16 TB for a 4K page size and 64 TB for a 16K page size and it equals
400 * to 16 * 1024 * 1024 / 2 segments.
401 */
402#define F2FS_MAX_SEGMENT       ((16 * 1024 * 1024) / 2)
403
404/*
405 * Note that f2fs_sit_entry->vblocks has the following bit-field information.
406 * [15:10] : allocation type such as CURSEG_XXXX_TYPE
407 * [9:0] : valid block count
408 */
409#define SIT_VBLOCKS_SHIFT	10
410#define SIT_VBLOCKS_MASK	((1 << SIT_VBLOCKS_SHIFT) - 1)
411#define GET_SIT_VBLOCKS(raw_sit)				\
412	(le16_to_cpu((raw_sit)->vblocks) & SIT_VBLOCKS_MASK)
413#define GET_SIT_TYPE(raw_sit)					\
414	((le16_to_cpu((raw_sit)->vblocks) & ~SIT_VBLOCKS_MASK)	\
415	 >> SIT_VBLOCKS_SHIFT)
416
417struct f2fs_sit_entry {
418	__le16 vblocks;				/* reference above */
419	__u8 valid_map[SIT_VBLOCK_MAP_SIZE];	/* bitmap for valid blocks */
420	__le64 mtime;				/* segment age for cleaning */
421} __packed;
422
423struct f2fs_sit_block {
424	struct f2fs_sit_entry entries[SIT_ENTRY_PER_BLOCK];
425} __packed;
426
427/*
428 * For segment summary
429 *
430 * One summary block with 4KB size contains exactly 512 summary entries, which
431 * represents exactly one segment with 2MB size.
432 * Similarly, in the case of block with 16KB size, it represents one segment with 8MB size.
433 * Not allow to change the basic units.
434 *
435 * NOTE: For initializing fields, you must use set_summary
436 *
437 * - If data page, nid represents dnode's nid
438 * - If node page, nid represents the node page's nid.
439 *
440 * The ofs_in_node is used by only data page. It represents offset
441 * from node's page's beginning to get a data block address.
442 * ex) data_blkaddr = (block_t)(nodepage_start_address + ofs_in_node)
443 */
444#define	SUMMARY_SIZE		(7)	/* sizeof(struct f2fs_summary) */
445#define	SUM_FOOTER_SIZE		(5)	/* sizeof(struct summary_footer) */
446
447/* a summary entry for a block in a segment */
448struct f2fs_summary {
449	__le32 nid;		/* parent node id */
450	union {
451		__u8 reserved[3];
452		struct {
453			__u8 version;		/* node version number */
454			__le16 ofs_in_node;	/* block index in parent node */
455		} __packed;
456	};
457} __packed;
458
459/* summary block type, node or data, is stored to the summary_footer */
460#define SUM_TYPE_NODE		(1)
461#define SUM_TYPE_DATA		(0)
462
463struct summary_footer {
464	unsigned char entry_type;	/* SUM_TYPE_XXX */
465	__le32 check_sum;		/* summary checksum */
466} __packed;
467
468/*
469 * frequently updated NAT/SIT entries can be stored in the spare area in
470 * summary blocks
471 */
472enum {
473	NAT_JOURNAL = 0,
474	SIT_JOURNAL
475};
476
477struct nat_journal_entry {
478	__le32 nid;
479	struct f2fs_nat_entry ne;
480} __packed;
481
482/*
483 * The nat_journal structure is a placeholder whose actual size varies depending
484 * on the use of packed_ssa. Therefore, it must always be accessed only through
485 * specific sets of macros and fields, and size calculations should use
486 * size-related macros instead of sizeof().
487 * Relevant macros: sbi->nat_journal_entries, nat_in_journal(),
488 * nid_in_journal(), MAX_NAT_JENTRIES().
489 */
490struct nat_journal {
491	struct nat_journal_entry entries[0];
492} __packed;
493
494struct sit_journal_entry {
495	__le32 segno;
496	struct f2fs_sit_entry se;
497} __packed;
498
499/*
500 * The sit_journal structure is a placeholder whose actual size varies depending
501 * on the use of packed_ssa. Therefore, it must always be accessed only through
502 * specific sets of macros and fields, and size calculations should use
503 * size-related macros instead of sizeof().
504 * Relevant macros: sbi->sit_journal_entries, sit_in_journal(),
505 * segno_in_journal(), MAX_SIT_JENTRIES().
506 */
507struct sit_journal {
508	struct sit_journal_entry entries[0];
509} __packed;
510
511struct f2fs_extra_info {
512	__le64 kbytes_written;
513	__u8 reserved[];
514} __packed;
515
516struct f2fs_journal {
517	union {
518		__le16 n_nats;
519		__le16 n_sits;
520	};
521	/* spare area is used by NAT or SIT journals or extra info */
522	union {
523		struct nat_journal nat_j;
524		struct sit_journal sit_j;
525		struct f2fs_extra_info info;
526	};
527} __packed;
528
529/*
530 * Block-sized summary block structure
531 *
532 * The f2fs_summary_block structure is a placeholder whose actual size varies
533 * depending on the use of packed_ssa. Therefore, it must always be accessed
534 * only through specific sets of macros and fields, and size calculations should
535 * use size-related macros instead of sizeof().
536 * Relevant macros: sbi->sum_blocksize, sbi->entries_in_sum,
537 * sbi->sum_entry_size, sum_entries(), sum_journal(), sum_footer().
538 *
539 * Summary Block Layout
540 *
541 * +-----------------------+ <--- Block Start
542 * | struct f2fs_summary   |
543 * | entries[0]            |
544 * | ...                   |
545 * | entries[N-1]          |
546 * +-----------------------+
547 * | struct f2fs_journal   |
548 * +-----------------------+
549 * | struct summary_footer |
550 * +-----------------------+ <--- Block End
551 */
552struct f2fs_summary_block {
553	struct f2fs_summary entries[0];
554	// struct f2fs_journal journal;
555	// struct summary_footer footer;
556} __packed;
557
558/*
559 * For directory operations
560 */
561#define F2FS_DOT_HASH		0
562#define F2FS_DDOT_HASH		F2FS_DOT_HASH
563#define F2FS_MAX_HASH		(~((0x3ULL) << 62))
564#define F2FS_HASH_COL_BIT	((0x1ULL) << 63)
565
566typedef __le32	f2fs_hash_t;
567
568/* One directory entry slot covers 8bytes-long file name */
569#define F2FS_SLOT_LEN		8
570#define F2FS_SLOT_LEN_BITS	3
571
572#define GET_DENTRY_SLOTS(x) (((x) + F2FS_SLOT_LEN - 1) >> F2FS_SLOT_LEN_BITS)
573
574/* MAX level for dir lookup */
575#define MAX_DIR_HASH_DEPTH	63
576
577/* MAX buckets in one level of dir */
578#define MAX_DIR_BUCKETS		BIT((MAX_DIR_HASH_DEPTH / 2) - 1)
579
580/*
581 * space utilization of regular dentry and inline dentry (w/o extra reservation)
582 * when block size is 4KB.
583 *		regular dentry		inline dentry (def)	inline dentry (min)
584 * bitmap	1 * 27 = 27		1 * 23 = 23		1 * 1 = 1
585 * reserved	1 * 3 = 3		1 * 7 = 7		1 * 1 = 1
586 * dentry	11 * 214 = 2354		11 * 182 = 2002		11 * 2 = 22
587 * filename	8 * 214 = 1712		8 * 182 = 1456		8 * 2 = 16
588 * total	4096			3488			40
589 *
590 * Note: there are more reserved space in inline dentry than in regular
591 * dentry, when converting inline dentry we should handle this carefully.
592 */
593
594/* the number of dentry in a block */
595#define NR_DENTRY_IN_BLOCK	((BITS_PER_BYTE * F2FS_BLKSIZE) / \
596					((SIZE_OF_DIR_ENTRY + F2FS_SLOT_LEN) * BITS_PER_BYTE + 1))
597#define SIZE_OF_DIR_ENTRY	11	/* by byte */
598#define SIZE_OF_DENTRY_BITMAP	((NR_DENTRY_IN_BLOCK + BITS_PER_BYTE - 1) / \
599					BITS_PER_BYTE)
600#define SIZE_OF_RESERVED	(F2FS_BLKSIZE - ((SIZE_OF_DIR_ENTRY + \
601				F2FS_SLOT_LEN) * \
602				NR_DENTRY_IN_BLOCK + SIZE_OF_DENTRY_BITMAP))
603#define MIN_INLINE_DENTRY_SIZE		40	/* just include '.' and '..' entries */
604
605/* One directory entry slot representing F2FS_SLOT_LEN-sized file name */
606struct f2fs_dir_entry {
607	__le32 hash_code;	/* hash code of file name */
608	__le32 ino;		/* inode number */
609	__le16 name_len;	/* length of file name */
610	__u8 file_type;		/* file type */
611} __packed;
612
613/* Block-sized directory entry block */
614struct f2fs_dentry_block {
615	/* validity bitmap for directory entries in each block */
616	__u8 dentry_bitmap[SIZE_OF_DENTRY_BITMAP];
617	__u8 reserved[SIZE_OF_RESERVED];
618	struct f2fs_dir_entry dentry[NR_DENTRY_IN_BLOCK];
619	__u8 filename[NR_DENTRY_IN_BLOCK][F2FS_SLOT_LEN];
620} __packed;
621
622#define	F2FS_DEF_PROJID		0	/* default project ID */
623
624#endif  /* _LINUX_F2FS_FS_H */