xref: /csrg-svn/sys/ufs/lfs/lfs.h (revision 51215)
1 /*-
2  * Copyright (c) 1991 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  *
7  *	@(#)lfs.h	5.5 (Berkeley) 10/02/91
8  */
9 
10 typedef struct buf	BUF;
11 typedef struct dinode	DINODE;
12 typedef struct inode	INODE;
13 typedef struct mount	MOUNT;
14 typedef struct ucred	UCRED;
15 typedef struct ufsmount	UFSMOUNT;
16 typedef struct vnode	VNODE;
17 
18 #define	LFS_LABELPAD	8192		/* LFS label size */
19 #define	LFS_SBPAD	8192		/* LFS superblock size */
20 #define MAXMNTLEN	512		/* XXX move from fs.h to mount.h */
21 
22 /* On-disk and in-memory checkpoint segment usage structure. */
23 typedef struct segusage SEGUSE;
24 struct segusage {
25 	u_long	su_nbytes;		/* number of live bytes */
26 	u_long	su_lastmod;		/* last modified timestamp */
27 #define	SEGUSE_DIRTY	0x1		/* XXX fill in comment */
28 	u_long	su_flags;
29 };
30 
31 /* On-disk file information.  One per file with data blocks in the segment. */
32 typedef struct finfo FINFO;
33 struct finfo {
34 	u_long	fi_nblocks;		/* number of blocks */
35 	u_long	fi_version;		/* version number */
36 	u_long	fi_ino;			/* inode number */
37 	long	fi_blocks[1];		/* array of logical block numbers */
38 };
39 
40 /* In-memory description of a segment about to be written */
41 typedef struct segment SEGMENT;
42 struct segment {
43 	SEGMENT	*nextp;			/* Links segments together */
44 	BUF	**bpp;			/* Pointer to buffer array */
45 	BUF	**cbpp;			/* Pointer to next available bp */
46 	BUF	*ibp;			/* Buffer pointer to inode page */
47 	BUF	*sbp;			/* Segment summary buffer pointer */
48 	void	*segsum;		/* Segment Summary info */
49 	u_long	sum_bytes_left;		/* Bytes left in summary */
50 	u_long	seg_bytes_left;		/* Bytes left in segment */
51 	daddr_t	saddr;			/* Current disk address */
52 	daddr_t	sum_addr;		/* Address of current summary */
53 	u_long	ninodes;		/* Number of inodes in this segment */
54 	u_long	sum_num;		/* Number of current summary block */
55 	u_long	seg_number;		/* Number of this segment */
56 	FINFO	*fip;			/* Current fileinfo pointer */
57 };
58 
59 /* On-disk and in-memory super block. */
60 typedef struct lfs LFS;
61 struct lfs {
62 #define	LFS_MAGIC	0xbedead
63 	u_long	lfs_magic;		/* magic number */
64 #define	LFS_VERSION	1
65 	u_long	lfs_version;		/* version number */
66 
67 	u_long	lfs_size;		/* number of blocks in fs */
68 	u_long	lfs_ssize;		/* number of blocks per segment */
69 	u_long	lfs_dsize;		/* number of data blocks in fs */
70 	u_long	lfs_bsize;		/* size of basic blocks in fs */
71 	u_long	lfs_fsize;		/* size of frag blocks in fs */
72 	u_long	lfs_frag;		/* number of frags in a block in fs */
73 
74 /* Checkpoint region. */
75 	ino_t	lfs_free;		/* start of the free list */
76 	u_long	lfs_bfree;		/* number of free blocks */
77 	u_long	lfs_nfiles;		/* number of allocated inodes */
78 	daddr_t	lfs_idaddr;		/* inode file disk address */
79 	ino_t	lfs_ifile;		/* inode file inode number */
80 	daddr_t	lfs_lastseg;		/* last segment written */
81 	daddr_t	lfs_nextseg;		/* next segment to write */
82 	u_long	lfs_tstamp;		/* time stamp */
83 
84 /* These are configuration parameters. */
85 	u_long	lfs_minfree;		/* minimum percentage of free blocks */
86 
87 /* These fields can be computed from the others. */
88 	u_long	lfs_inopb;		/* inodes per block */
89 	u_long	lfs_ifpb;		/* IFILE entries per block */
90 	u_long	lfs_nindir;		/* indirect pointers per block */
91 	u_long	lfs_nseg;		/* number of segments */
92 	u_long	lfs_nspf;		/* number of sectors per fragment */
93 	u_long	lfs_segtabsz;		/* segment table size in blocks */
94 
95 	u_long	lfs_segmask;		/* calculate offset within a segment */
96 	u_long	lfs_segshift;		/* fast mult/div for segments */
97 	u_long	lfs_bmask;		/* calc block offset from file offset */
98 	u_long	lfs_bshift;		/* calc block number from file offset */
99 	u_long	lfs_ffmask;		/* calc frag offset from file offset */
100 	u_long	lfs_ffshift;		/* fast mult/div for frag from file */
101 	u_long	lfs_fbmask;		/* calc frag offset from block offset */
102 	u_long	lfs_fbshift;		/* fast mult/div for frag from block */
103 	u_long	lfs_fsbtodb;		/* fsbtodb and dbtofsb shift constant */
104 
105 #define	LFS_MIN_SBINTERVAL	5	/* minimum superblock segment spacing */
106 #define	LFS_MAXNUMSB		10	/* superblock disk offsets */
107 	daddr_t	lfs_sboffs[LFS_MAXNUMSB];
108 
109 /* These fields are set at mount time and are meaningless on disk. */
110 	VNODE	*lfs_ivnode;		/* vnode for the ifile */
111 	SEGUSE	*lfs_segtab;		/* in-memory segment usage table */
112 	SEGMENT	*lfs_seglist;		/* list of segments being written */
113 	u_long	lfs_iocount;		/* Number of ios pending */
114 	u_char	lfs_fmod;		/* super block modified flag */
115 	u_char	lfs_clean;		/* file system is clean flag */
116 	u_char	lfs_ronly;		/* mounted read-only flag */
117 	u_char	lfs_flags;		/* currently unused flag */
118 	u_char	lfs_fsmnt[MAXMNTLEN];	/* name mounted on */
119 	u_char	pad[3];			/* long-align */
120 
121 /* Checksum; valid on disk. */
122 	u_long	lfs_cksum;		/* checksum for superblock checking */
123 };
124 
125 /*
126  * The root inode is the root of the file system.  Inode 0 is the out-of-band
127  * inode, and inode 1 is the inode number for the ifile.  Thus the root inode
128  * is 2.
129  */
130 #define ROOTINO         ((ino_t)2)
131 #define	LOSTFOUNDINO	((ino_t)3)
132 
133 /* Fixed inode numbers. */
134 #define	LFS_UNUSED_INUM	0		/* Out of band inode number. */
135 #define	LFS_IFILE_INUM	1		/* Inode number of the ifile. */
136 					/* First free inode number. */
137 #define	LFS_FIRST_INUM	(LOSTFOUNDINO + 1)
138 
139 /*
140  * Used to access the first spare of the dinode which we use to store
141  * the ifile number so we can identify them
142  */
143 #define	di_inum	di_spare[0]
144 
145 /*
146  * Logical block numbers of indirect blocks.
147  */
148 #define S_INDIR	-1
149 #define D_INDIR -2
150 #define T_INDIR -3
151 
152 typedef struct ifile IFILE;
153 struct ifile {
154 	u_long	if_version;		/* inode version number */
155 #define	LFS_UNUSED_DADDR	0	/* out-of-band daddr */
156 	daddr_t	if_daddr;		/* inode disk address */
157 	union {
158 		ino_t	nextfree;	/* next-unallocated inode */
159 		time_t	st_atime;	/* access time */
160 	} __ifile_u;
161 #define	if_st_atime	__ifile_u.st_atime
162 #define	if_nextfree	__ifile_u.nextfree
163 };
164 
165 /* Segment table size, in blocks. */
166 #define	SEGTABSIZE(fs) \
167 	(((fs)->fs_nseg * sizeof(SEGUSE) + \
168 	    ((fs)->fs_bsize - 1)) >> (fs)->fs_bshift)
169 
170 #define	SEGTABSIZE_SU(fs) \
171 	(((fs)->lfs_nseg * sizeof(SEGUSE) + \
172 	    ((fs)->lfs_bsize - 1)) >> (fs)->lfs_bshift)
173 
174 /*
175  * All summary blocks are the same size, so we can always read a summary
176  * block easily from a segment
177  */
178 #define	LFS_SUMMARY_SIZE	512
179 
180 /* On-disk segment summary information */
181 typedef struct segsum SEGSUM;
182 struct segsum {
183 	u_long	ss_cksum;		/* check sum */
184 	daddr_t	ss_next;		/* next segment */
185 	daddr_t	ss_prev;		/* next segment */
186 	daddr_t	ss_nextsum;		/* next summary block */
187 	u_long	ss_create;		/* creation time stamp */
188 	u_long	ss_nfinfo;		/* number of file info structures */
189 	u_long	ss_ninos;		/* number of inode blocks */
190 	/* FINFO's... */
191 };
192 
193 /* NINDIR is the number of indirects in a file system block. */
194 #define	NINDIR(fs)	((fs)->lfs_nindir)
195 
196 /* INOPB is the number of inodes in a secondary storage block. */
197 #define	INOPB(fs)	((fs)->lfs_inopb)
198 
199 /* IFPB -- IFILE's per block */
200 #define	IFPB(fs)	((fs)->lfs_ifpb)
201 
202 #define	blksize(fs)		((fs)->lfs_bsize)
203 #define	blkoff(fs, loc)		((loc) & (fs)->lfs_bmask)
204 #define	fsbtodb(fs, b)		((b) << (fs)->lfs_fsbtodb)
205 #define	lblkno(fs, loc)		((loc) >> (fs)->lfs_bshift)
206 #define	lblktosize(fs, blk)	((blk) << (fs)->lfs_bshift)
207 #define numfrags(fs, loc)	/* calculates (loc / fs->fs_fsize) */ \
208 	((loc) >> (fs)->lfs_bshift)
209 #define satosn(fs, saddr) \
210 	((int)((saddr - fs->lfs_sboffs[0]) / fsbtodb(fs, fs->lfs_ssize)))
211 #define sntosa(fs, sn) \
212 	((daddr_t)(sn * (fs->lfs_ssize << fs->lfs_fsbtodb) + fs->lfs_sboffs[0]))
213