1  /* SPDX-License-Identifier: LGPL-2.1+ WITH Linux-syscall-note */
2  /*
3   * nilfs2_ondisk.h - NILFS2 on-disk structures
4   *
5   * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6   *
7   * This program is free software; you can redistribute it and/or modify
8   * it under the terms of the GNU Lesser General Public License as published
9   * by the Free Software Foundation; either version 2.1 of the License, or
10   * (at your option) any later version.
11   */
12  /*
13   *  linux/include/linux/ext2_fs.h
14   *
15   * Copyright (C) 1992, 1993, 1994, 1995
16   * Remy Card (card@masi.ibp.fr)
17   * Laboratoire MASI - Institut Blaise Pascal
18   * Universite Pierre et Marie Curie (Paris VI)
19   *
20   *  from
21   *
22   *  linux/include/linux/minix_fs.h
23   *
24   *  Copyright (C) 1991, 1992  Linus Torvalds
25   */
26  
27  #ifndef _LINUX_NILFS2_ONDISK_H
28  #define _LINUX_NILFS2_ONDISK_H
29  
30  #include <linux/types.h>
31  #include <linux/magic.h>
32  #include <asm/byteorder.h>
33  
34  #define NILFS_INODE_BMAP_SIZE	7
35  
36  /**
37   * struct nilfs_inode - structure of an inode on disk
38   * @i_blocks: blocks count
39   * @i_size: size in bytes
40   * @i_ctime: creation time (seconds)
41   * @i_mtime: modification time (seconds)
42   * @i_ctime_nsec: creation time (nano seconds)
43   * @i_mtime_nsec: modification time (nano seconds)
44   * @i_uid: user id
45   * @i_gid: group id
46   * @i_mode: file mode
47   * @i_links_count: links count
48   * @i_flags: file flags
49   * @i_bmap: block mapping
50   * @i_xattr: extended attributes
51   * @i_generation: file generation (for NFS)
52   * @i_pad: padding
53   */
54  struct nilfs_inode {
55  	__le64	i_blocks;
56  	__le64	i_size;
57  	__le64	i_ctime;
58  	__le64	i_mtime;
59  	__le32	i_ctime_nsec;
60  	__le32	i_mtime_nsec;
61  	__le32	i_uid;
62  	__le32	i_gid;
63  	__le16	i_mode;
64  	__le16	i_links_count;
65  	__le32	i_flags;
66  	__le64	i_bmap[NILFS_INODE_BMAP_SIZE];
67  #define i_device_code	i_bmap[0]
68  	__le64	i_xattr;
69  	__le32	i_generation;
70  	__le32	i_pad;
71  };
72  
73  #define NILFS_MIN_INODE_SIZE		128
74  
75  /**
76   * struct nilfs_super_root - structure of super root
77   * @sr_sum: check sum
78   * @sr_bytes: byte count of the structure
79   * @sr_flags: flags (reserved)
80   * @sr_nongc_ctime: write time of the last segment not for cleaner operation
81   * @sr_dat: DAT file inode
82   * @sr_cpfile: checkpoint file inode
83   * @sr_sufile: segment usage file inode
84   */
85  struct nilfs_super_root {
86  	__le32 sr_sum;
87  	__le16 sr_bytes;
88  	__le16 sr_flags;
89  	__le64 sr_nongc_ctime;
90  	struct nilfs_inode sr_dat;
91  	struct nilfs_inode sr_cpfile;
92  	struct nilfs_inode sr_sufile;
93  };
94  
95  #define NILFS_SR_MDT_OFFSET(inode_size, i)  \
96  	((unsigned long)&((struct nilfs_super_root *)0)->sr_dat + \
97  			(inode_size) * (i))
98  #define NILFS_SR_DAT_OFFSET(inode_size)     NILFS_SR_MDT_OFFSET(inode_size, 0)
99  #define NILFS_SR_CPFILE_OFFSET(inode_size)  NILFS_SR_MDT_OFFSET(inode_size, 1)
100  #define NILFS_SR_SUFILE_OFFSET(inode_size)  NILFS_SR_MDT_OFFSET(inode_size, 2)
101  #define NILFS_SR_BYTES(inode_size)	    NILFS_SR_MDT_OFFSET(inode_size, 3)
102  
103  /*
104   * Maximal mount counts
105   */
106  #define NILFS_DFL_MAX_MNT_COUNT		50      /* 50 mounts */
107  
108  /*
109   * File system states (sbp->s_state, nilfs->ns_mount_state)
110   */
111  #define NILFS_VALID_FS			0x0001  /* Unmounted cleanly */
112  #define NILFS_ERROR_FS			0x0002  /* Errors detected */
113  #define NILFS_RESIZE_FS			0x0004	/* Resize required */
114  
115  /*
116   * Mount flags (sbi->s_mount_opt)
117   */
118  #define NILFS_MOUNT_ERROR_MODE		0x0070  /* Error mode mask */
119  #define NILFS_MOUNT_ERRORS_CONT		0x0010  /* Continue on errors */
120  #define NILFS_MOUNT_ERRORS_RO		0x0020  /* Remount fs ro on errors */
121  #define NILFS_MOUNT_ERRORS_PANIC	0x0040  /* Panic on errors */
122  #define NILFS_MOUNT_BARRIER		0x1000  /* Use block barriers */
123  #define NILFS_MOUNT_STRICT_ORDER	0x2000  /*
124  						 * Apply strict in-order
125  						 * semantics also for data
126  						 */
127  #define NILFS_MOUNT_NORECOVERY		0x4000  /*
128  						 * Disable write access during
129  						 * mount-time recovery
130  						 */
131  #define NILFS_MOUNT_DISCARD		0x8000  /* Issue DISCARD requests */
132  
133  
134  /**
135   * struct nilfs_super_block - structure of super block on disk
136   */
137  struct nilfs_super_block {
138  /*00*/	__le32	s_rev_level;		/* Revision level */
139  	__le16	s_minor_rev_level;	/* minor revision level */
140  	__le16	s_magic;		/* Magic signature */
141  
142  	__le16  s_bytes;		/*
143  					 * Bytes count of CRC calculation
144  					 * for this structure. s_reserved
145  					 * is excluded.
146  					 */
147  	__le16  s_flags;		/* flags */
148  	__le32  s_crc_seed;		/* Seed value of CRC calculation */
149  /*10*/	__le32	s_sum;			/* Check sum of super block */
150  
151  	__le32	s_log_block_size;	/*
152  					 * Block size represented as follows
153  					 * blocksize =
154  					 *     1 << (s_log_block_size + 10)
155  					 */
156  	__le64  s_nsegments;		/* Number of segments in filesystem */
157  /*20*/	__le64  s_dev_size;		/* block device size in bytes */
158  	__le64	s_first_data_block;	/* 1st seg disk block number */
159  /*30*/	__le32  s_blocks_per_segment;   /* number of blocks per full segment */
160  	__le32	s_r_segments_percentage; /* Reserved segments percentage */
161  
162  	__le64  s_last_cno;		/* Last checkpoint number */
163  /*40*/	__le64  s_last_pseg;		/* disk block addr pseg written last */
164  	__le64  s_last_seq;             /* seq. number of seg written last */
165  /*50*/	__le64	s_free_blocks_count;	/* Free blocks count */
166  
167  	__le64	s_ctime;		/*
168  					 * Creation time (execution time of
169  					 * newfs)
170  					 */
171  /*60*/	__le64	s_mtime;		/* Mount time */
172  	__le64	s_wtime;		/* Write time */
173  /*70*/	__le16	s_mnt_count;		/* Mount count */
174  	__le16	s_max_mnt_count;	/* Maximal mount count */
175  	__le16	s_state;		/* File system state */
176  	__le16	s_errors;		/* Behaviour when detecting errors */
177  	__le64	s_lastcheck;		/* time of last check */
178  
179  /*80*/	__le32	s_checkinterval;	/* max. time between checks */
180  	__le32	s_creator_os;		/* OS */
181  	__le16	s_def_resuid;		/* Default uid for reserved blocks */
182  	__le16	s_def_resgid;		/* Default gid for reserved blocks */
183  	__le32	s_first_ino;		/* First non-reserved inode */
184  
185  /*90*/	__le16  s_inode_size;		/* Size of an inode */
186  	__le16  s_dat_entry_size;       /* Size of a dat entry */
187  	__le16  s_checkpoint_size;      /* Size of a checkpoint */
188  	__le16	s_segment_usage_size;	/* Size of a segment usage */
189  
190  /*98*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
191  /*A8*/	char	s_volume_name[80];	/* volume name */
192  
193  /*F8*/	__le32  s_c_interval;           /* Commit interval of segment */
194  	__le32  s_c_block_max;          /*
195  					 * Threshold of data amount for
196  					 * the segment construction
197  					 */
198  /*100*/	__le64  s_feature_compat;	/* Compatible feature set */
199  	__le64  s_feature_compat_ro;	/* Read-only compatible feature set */
200  	__le64  s_feature_incompat;	/* Incompatible feature set */
201  	__u32	s_reserved[186];	/* padding to the end of the block */
202  };
203  
204  /*
205   * Codes for operating systems
206   */
207  #define NILFS_OS_LINUX		0
208  /* Codes from 1 to 4 are reserved to keep compatibility with ext2 creator-OS */
209  
210  /*
211   * Revision levels
212   */
213  #define NILFS_CURRENT_REV	2	/* current major revision */
214  #define NILFS_MINOR_REV		0	/* minor revision */
215  #define NILFS_MIN_SUPP_REV	2	/* minimum supported revision */
216  
217  /*
218   * Feature set definitions
219   *
220   * If there is a bit set in the incompatible feature set that the kernel
221   * doesn't know about, it should refuse to mount the filesystem.
222   */
223  #define NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT	0x00000001ULL
224  
225  #define NILFS_FEATURE_COMPAT_SUPP	0ULL
226  #define NILFS_FEATURE_COMPAT_RO_SUPP	NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT
227  #define NILFS_FEATURE_INCOMPAT_SUPP	0ULL
228  
229  /*
230   * Bytes count of super_block for CRC-calculation
231   */
232  #define NILFS_SB_BYTES  \
233  	((long)&((struct nilfs_super_block *)0)->s_reserved)
234  
235  /*
236   * Special inode number
237   */
238  #define NILFS_ROOT_INO		2	/* Root file inode */
239  #define NILFS_DAT_INO		3	/* DAT file */
240  #define NILFS_CPFILE_INO	4	/* checkpoint file */
241  #define NILFS_SUFILE_INO	5	/* segment usage file */
242  #define NILFS_IFILE_INO		6	/* ifile */
243  #define NILFS_ATIME_INO		7	/* Atime file (reserved) */
244  #define NILFS_XATTR_INO		8	/* Xattribute file (reserved) */
245  #define NILFS_SKETCH_INO	10	/* Sketch file */
246  #define NILFS_USER_INO		11	/* Fisrt user's file inode number */
247  
248  #define NILFS_SB_OFFSET_BYTES	1024	/* byte offset of nilfs superblock */
249  
250  #define NILFS_SEG_MIN_BLOCKS	16	/*
251  					 * Minimum number of blocks in
252  					 * a full segment
253  					 */
254  #define NILFS_PSEG_MIN_BLOCKS	2	/*
255  					 * Minimum number of blocks in
256  					 * a partial segment
257  					 */
258  #define NILFS_MIN_NRSVSEGS	8	/*
259  					 * Minimum number of reserved
260  					 * segments
261  					 */
262  
263  /*
264   * We call DAT, cpfile, and sufile root metadata files.  Inodes of
265   * these files are written in super root block instead of ifile, and
266   * garbage collector doesn't keep any past versions of these files.
267   */
268  #define NILFS_ROOT_METADATA_FILE(ino) \
269  	((ino) >= NILFS_DAT_INO && (ino) <= NILFS_SUFILE_INO)
270  
271  /*
272   * bytes offset of secondary super block
273   */
274  #define NILFS_SB2_OFFSET_BYTES(devsize)	((((devsize) >> 12) - 1) << 12)
275  
276  /*
277   * Maximal count of links to a file
278   */
279  #define NILFS_LINK_MAX		32000
280  
281  /*
282   * Structure of a directory entry
283   *  (Same as ext2)
284   */
285  
286  #define NILFS_NAME_LEN 255
287  
288  /*
289   * Block size limitations
290   */
291  #define NILFS_MIN_BLOCK_SIZE		1024
292  #define NILFS_MAX_BLOCK_SIZE		65536
293  
294  /*
295   * The new version of the directory entry.  Since V0 structures are
296   * stored in intel byte order, and the name_len field could never be
297   * bigger than 255 chars, it's safe to reclaim the extra byte for the
298   * file_type field.
299   */
300  struct nilfs_dir_entry {
301  	__le64	inode;			/* Inode number */
302  	__le16	rec_len;		/* Directory entry length */
303  	__u8	name_len;		/* Name length */
304  	__u8	file_type;		/* Dir entry type (file, dir, etc) */
305  	char	name[NILFS_NAME_LEN];	/* File name */
306  	char    pad;
307  };
308  
309  /*
310   * NILFS directory file types.  Only the low 3 bits are used.  The
311   * other bits are reserved for now.
312   */
313  enum {
314  	NILFS_FT_UNKNOWN,
315  	NILFS_FT_REG_FILE,
316  	NILFS_FT_DIR,
317  	NILFS_FT_CHRDEV,
318  	NILFS_FT_BLKDEV,
319  	NILFS_FT_FIFO,
320  	NILFS_FT_SOCK,
321  	NILFS_FT_SYMLINK,
322  	NILFS_FT_MAX
323  };
324  
325  /*
326   * NILFS_DIR_PAD defines the directory entries boundaries
327   *
328   * NOTE: It must be a multiple of 8
329   */
330  #define NILFS_DIR_PAD			8
331  #define NILFS_DIR_ROUND			(NILFS_DIR_PAD - 1)
332  #define NILFS_DIR_REC_LEN(name_len)	(((name_len) + 12 + NILFS_DIR_ROUND) & \
333  					~NILFS_DIR_ROUND)
334  #define NILFS_MAX_REC_LEN		((1 << 16) - 1)
335  
336  /**
337   * struct nilfs_finfo - file information
338   * @fi_ino: inode number
339   * @fi_cno: checkpoint number
340   * @fi_nblocks: number of blocks (including intermediate blocks)
341   * @fi_ndatablk: number of file data blocks
342   */
343  struct nilfs_finfo {
344  	__le64 fi_ino;
345  	__le64 fi_cno;
346  	__le32 fi_nblocks;
347  	__le32 fi_ndatablk;
348  };
349  
350  /**
351   * struct nilfs_binfo_v - information on a data block (except DAT)
352   * @bi_vblocknr: virtual block number
353   * @bi_blkoff: block offset
354   */
355  struct nilfs_binfo_v {
356  	__le64 bi_vblocknr;
357  	__le64 bi_blkoff;
358  };
359  
360  /**
361   * struct nilfs_binfo_dat - information on a DAT node block
362   * @bi_blkoff: block offset
363   * @bi_level: level
364   * @bi_pad: padding
365   */
366  struct nilfs_binfo_dat {
367  	__le64 bi_blkoff;
368  	__u8 bi_level;
369  	__u8 bi_pad[7];
370  };
371  
372  /**
373   * union nilfs_binfo: block information
374   * @bi_v: nilfs_binfo_v structure
375   * @bi_dat: nilfs_binfo_dat structure
376   */
377  union nilfs_binfo {
378  	struct nilfs_binfo_v bi_v;
379  	struct nilfs_binfo_dat bi_dat;
380  };
381  
382  /**
383   * struct nilfs_segment_summary - segment summary header
384   * @ss_datasum: checksum of data
385   * @ss_sumsum: checksum of segment summary
386   * @ss_magic: magic number
387   * @ss_bytes: size of this structure in bytes
388   * @ss_flags: flags
389   * @ss_seq: sequence number
390   * @ss_create: creation timestamp
391   * @ss_next: next segment
392   * @ss_nblocks: number of blocks
393   * @ss_nfinfo: number of finfo structures
394   * @ss_sumbytes: total size of segment summary in bytes
395   * @ss_pad: padding
396   * @ss_cno: checkpoint number
397   */
398  struct nilfs_segment_summary {
399  	__le32 ss_datasum;
400  	__le32 ss_sumsum;
401  	__le32 ss_magic;
402  	__le16 ss_bytes;
403  	__le16 ss_flags;
404  	__le64 ss_seq;
405  	__le64 ss_create;
406  	__le64 ss_next;
407  	__le32 ss_nblocks;
408  	__le32 ss_nfinfo;
409  	__le32 ss_sumbytes;
410  	__le32 ss_pad;
411  	__le64 ss_cno;
412  	/* array of finfo structures */
413  };
414  
415  #define NILFS_SEGSUM_MAGIC	0x1eaffa11  /* segment summary magic number */
416  
417  /*
418   * Segment summary flags
419   */
420  #define NILFS_SS_LOGBGN 0x0001  /* begins a logical segment */
421  #define NILFS_SS_LOGEND 0x0002  /* ends a logical segment */
422  #define NILFS_SS_SR     0x0004  /* has super root */
423  #define NILFS_SS_SYNDT  0x0008  /* includes data only updates */
424  #define NILFS_SS_GC     0x0010  /* segment written for cleaner operation */
425  
426  /**
427   * struct nilfs_btree_node - header of B-tree node block
428   * @bn_flags: flags
429   * @bn_level: level
430   * @bn_nchildren: number of children
431   * @bn_pad: padding
432   */
433  struct nilfs_btree_node {
434  	__u8 bn_flags;
435  	__u8 bn_level;
436  	__le16 bn_nchildren;
437  	__le32 bn_pad;
438  };
439  
440  /* flags */
441  #define NILFS_BTREE_NODE_ROOT   0x01
442  
443  /* level */
444  #define NILFS_BTREE_LEVEL_DATA          0
445  #define NILFS_BTREE_LEVEL_NODE_MIN      (NILFS_BTREE_LEVEL_DATA + 1)
446  #define NILFS_BTREE_LEVEL_MAX           14	/* Max level (exclusive) */
447  
448  /**
449   * struct nilfs_direct_node - header of built-in bmap array
450   * @dn_flags: flags
451   * @dn_pad: padding
452   */
453  struct nilfs_direct_node {
454  	__u8 dn_flags;
455  	__u8 pad[7];
456  };
457  
458  /**
459   * struct nilfs_palloc_group_desc - block group descriptor
460   * @pg_nfrees: number of free entries in block group
461   */
462  struct nilfs_palloc_group_desc {
463  	__le32 pg_nfrees;
464  };
465  
466  /**
467   * struct nilfs_dat_entry - disk address translation entry
468   * @de_blocknr: block number
469   * @de_start: start checkpoint number
470   * @de_end: end checkpoint number
471   * @de_rsv: reserved for future use
472   */
473  struct nilfs_dat_entry {
474  	__le64 de_blocknr;
475  	__le64 de_start;
476  	__le64 de_end;
477  	__le64 de_rsv;
478  };
479  
480  #define NILFS_MIN_DAT_ENTRY_SIZE	32
481  
482  /**
483   * struct nilfs_snapshot_list - snapshot list
484   * @ssl_next: next checkpoint number on snapshot list
485   * @ssl_prev: previous checkpoint number on snapshot list
486   */
487  struct nilfs_snapshot_list {
488  	__le64 ssl_next;
489  	__le64 ssl_prev;
490  };
491  
492  /**
493   * struct nilfs_checkpoint - checkpoint structure
494   * @cp_flags: flags
495   * @cp_checkpoints_count: checkpoints count in a block
496   * @cp_snapshot_list: snapshot list
497   * @cp_cno: checkpoint number
498   * @cp_create: creation timestamp
499   * @cp_nblk_inc: number of blocks incremented by this checkpoint
500   * @cp_inodes_count: inodes count
501   * @cp_blocks_count: blocks count
502   * @cp_ifile_inode: inode of ifile
503   */
504  struct nilfs_checkpoint {
505  	__le32 cp_flags;
506  	__le32 cp_checkpoints_count;
507  	struct nilfs_snapshot_list cp_snapshot_list;
508  	__le64 cp_cno;
509  	__le64 cp_create;
510  	__le64 cp_nblk_inc;
511  	__le64 cp_inodes_count;
512  	__le64 cp_blocks_count;
513  
514  	/*
515  	 * Do not change the byte offset of ifile inode.
516  	 * To keep the compatibility of the disk format,
517  	 * additional fields should be added behind cp_ifile_inode.
518  	 */
519  	struct nilfs_inode cp_ifile_inode;
520  };
521  
522  #define NILFS_MIN_CHECKPOINT_SIZE	(64 + NILFS_MIN_INODE_SIZE)
523  
524  /* checkpoint flags */
525  enum {
526  	NILFS_CHECKPOINT_SNAPSHOT,
527  	NILFS_CHECKPOINT_INVALID,
528  	NILFS_CHECKPOINT_SKETCH,
529  	NILFS_CHECKPOINT_MINOR,
530  };
531  
532  #define NILFS_CHECKPOINT_FNS(flag, name)				\
533  static inline void							\
534  nilfs_checkpoint_set_##name(struct nilfs_checkpoint *cp)		\
535  {									\
536  	cp->cp_flags = __cpu_to_le32(__le32_to_cpu(cp->cp_flags) |	\
537  				     (1UL << NILFS_CHECKPOINT_##flag));	\
538  }									\
539  static inline void							\
540  nilfs_checkpoint_clear_##name(struct nilfs_checkpoint *cp)		\
541  {									\
542  	cp->cp_flags = __cpu_to_le32(__le32_to_cpu(cp->cp_flags) &	\
543  				   ~(1UL << NILFS_CHECKPOINT_##flag));	\
544  }									\
545  static inline int							\
546  nilfs_checkpoint_##name(const struct nilfs_checkpoint *cp)		\
547  {									\
548  	return !!(__le32_to_cpu(cp->cp_flags) &				\
549  		  (1UL << NILFS_CHECKPOINT_##flag));			\
550  }
551  
552  NILFS_CHECKPOINT_FNS(SNAPSHOT, snapshot)
553  NILFS_CHECKPOINT_FNS(INVALID, invalid)
554  NILFS_CHECKPOINT_FNS(MINOR, minor)
555  
556  /**
557   * struct nilfs_cpfile_header - checkpoint file header
558   * @ch_ncheckpoints: number of checkpoints
559   * @ch_nsnapshots: number of snapshots
560   * @ch_snapshot_list: snapshot list
561   */
562  struct nilfs_cpfile_header {
563  	__le64 ch_ncheckpoints;
564  	__le64 ch_nsnapshots;
565  	struct nilfs_snapshot_list ch_snapshot_list;
566  };
567  
568  #define NILFS_CPFILE_FIRST_CHECKPOINT_OFFSET				\
569  	((sizeof(struct nilfs_cpfile_header) +				\
570  	  sizeof(struct nilfs_checkpoint) - 1) /			\
571  			sizeof(struct nilfs_checkpoint))
572  
573  /**
574   * struct nilfs_segment_usage - segment usage
575   * @su_lastmod: last modified timestamp
576   * @su_nblocks: number of blocks in segment
577   * @su_flags: flags
578   */
579  struct nilfs_segment_usage {
580  	__le64 su_lastmod;
581  	__le32 su_nblocks;
582  	__le32 su_flags;
583  };
584  
585  #define NILFS_MIN_SEGMENT_USAGE_SIZE	16
586  
587  /* segment usage flag */
588  enum {
589  	NILFS_SEGMENT_USAGE_ACTIVE,
590  	NILFS_SEGMENT_USAGE_DIRTY,
591  	NILFS_SEGMENT_USAGE_ERROR,
592  };
593  
594  #define NILFS_SEGMENT_USAGE_FNS(flag, name)				\
595  static inline void							\
596  nilfs_segment_usage_set_##name(struct nilfs_segment_usage *su)		\
597  {									\
598  	su->su_flags = __cpu_to_le32(__le32_to_cpu(su->su_flags) |	\
599  				   (1UL << NILFS_SEGMENT_USAGE_##flag));\
600  }									\
601  static inline void							\
602  nilfs_segment_usage_clear_##name(struct nilfs_segment_usage *su)	\
603  {									\
604  	su->su_flags =							\
605  		__cpu_to_le32(__le32_to_cpu(su->su_flags) &		\
606  			    ~(1UL << NILFS_SEGMENT_USAGE_##flag));      \
607  }									\
608  static inline int							\
609  nilfs_segment_usage_##name(const struct nilfs_segment_usage *su)	\
610  {									\
611  	return !!(__le32_to_cpu(su->su_flags) &				\
612  		  (1UL << NILFS_SEGMENT_USAGE_##flag));			\
613  }
614  
NILFS_SEGMENT_USAGE_FNS(ACTIVE,active)615  NILFS_SEGMENT_USAGE_FNS(ACTIVE, active)
616  NILFS_SEGMENT_USAGE_FNS(DIRTY, dirty)
617  NILFS_SEGMENT_USAGE_FNS(ERROR, error)
618  
619  static inline void
620  nilfs_segment_usage_set_clean(struct nilfs_segment_usage *su)
621  {
622  	su->su_lastmod = __cpu_to_le64(0);
623  	su->su_nblocks = __cpu_to_le32(0);
624  	su->su_flags = __cpu_to_le32(0);
625  }
626  
627  static inline int
nilfs_segment_usage_clean(const struct nilfs_segment_usage * su)628  nilfs_segment_usage_clean(const struct nilfs_segment_usage *su)
629  {
630  	return !__le32_to_cpu(su->su_flags);
631  }
632  
633  /**
634   * struct nilfs_sufile_header - segment usage file header
635   * @sh_ncleansegs: number of clean segments
636   * @sh_ndirtysegs: number of dirty segments
637   * @sh_last_alloc: last allocated segment number
638   */
639  struct nilfs_sufile_header {
640  	__le64 sh_ncleansegs;
641  	__le64 sh_ndirtysegs;
642  	__le64 sh_last_alloc;
643  	/* ... */
644  };
645  
646  #define NILFS_SUFILE_FIRST_SEGMENT_USAGE_OFFSET				\
647  	((sizeof(struct nilfs_sufile_header) +				\
648  	  sizeof(struct nilfs_segment_usage) - 1) /			\
649  			 sizeof(struct nilfs_segment_usage))
650  
651  #endif	/* _LINUX_NILFS2_ONDISK_H */
652