+/*
+ * Macros for access to cylinder group array structures
+ */
+#define cg_blktot(cgp) \
+ (((cgp)->cg_magic != CG_MAGIC) \
+ ? (((struct ocg *)(cgp))->cg_btot) \
+ : ((long *)((char *)(cgp) + (cgp)->cg_btotoff)))
+#define cg_blks(fs, cgp, cylno) \
+ (((cgp)->cg_magic != CG_MAGIC) \
+ ? (((struct ocg *)(cgp))->cg_b[cylno]) \
+ : ((short *)((char *)(cgp) + (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
+#define cg_inosused(cgp) \
+ (((cgp)->cg_magic != CG_MAGIC) \
+ ? (((struct ocg *)(cgp))->cg_iused) \
+ : ((char *)((char *)(cgp) + (cgp)->cg_iusedoff)))
+#define cg_blksfree(cgp) \
+ (((cgp)->cg_magic != CG_MAGIC) \
+ ? (((struct ocg *)(cgp))->cg_free) \
+ : ((u_char *)((char *)(cgp) + (cgp)->cg_freeoff)))
+#define cg_chkmagic(cgp) \
+ ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
+#define cg_clustersfree(cgp) \
+ ((u_char *)((char *)(cgp) + (cgp)->cg_clusteroff))
+#define cg_clustersum(cgp) \
+ ((long *)((char *)(cgp) + (cgp)->cg_clustersumoff))
+
+/*
+ * The following structure is defined
+ * for compatibility with old file systems.
+ */
+struct ocg {
+ struct ocg *cg_link; /* linked list of cyl groups */
+ struct ocg *cg_rlink; /* used for incore cyl groups */
+ time_t cg_time; /* time last written */
+ long cg_cgx; /* we are the cgx'th cylinder group */
+ short cg_ncyl; /* number of cyl's this cg */
+ short cg_niblk; /* number of inode blocks this cg */
+ long cg_ndblk; /* number of data blocks this cg */
+ struct csum cg_cs; /* cylinder summary information */
+ long cg_rotor; /* position of last used block */
+ long cg_frotor; /* position of last used frag */
+ long cg_irotor; /* position of last used inode */
+ long cg_frsum[8]; /* counts of available frags */
+ long cg_btot[32]; /* block totals per cylinder */
+ short cg_b[32][8]; /* positions of free blocks */
+ char cg_iused[256]; /* used inode map */
+ long cg_magic; /* magic number */
+ u_char cg_free[1]; /* free block map */
+/* actually longer */
+};
+
+/*
+ * Turn file system block numbers into disk block addresses.
+ * This maps file system blocks to device size blocks.
+ */
+#define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb)
+#define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb)
+
+/*
+ * Cylinder group macros to locate things in cylinder groups.
+ * They calc file system addresses of cylinder group data structures.
+ */
+#define cgbase(fs, c) ((daddr_t)((fs)->fs_fpg * (c)))
+#define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */
+#define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */
+#define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */
+#define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */
+#define cgstart(fs, c) \
+ (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
+
+/*
+ * Macros for handling inode numbers:
+ * inode number to file system block offset.
+ * inode number to cylinder group number.
+ * inode number to file system block address.
+ */
+#define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg)
+#define ino_to_fsba(fs, x) \
+ ((daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \
+ (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
+#define ino_to_fsbo(fs, x) ((x) % INOPB(fs))
+
+/*
+ * Give cylinder group number for a file system block.
+ * Give cylinder group block number for a file system block.
+ */
+#define dtog(fs, d) ((d) / (fs)->fs_fpg)
+#define dtogd(fs, d) ((d) % (fs)->fs_fpg)
+
+/*
+ * Extract the bits for a block from a map.
+ * Compute the cylinder and rotational position of a cyl block addr.
+ */
+#define blkmap(fs, map, loc) \
+ (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
+#define cbtocylno(fs, bno) \
+ ((bno) * NSPF(fs) / (fs)->fs_spc)
+#define cbtorpos(fs, bno) \
+ (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
+ (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
+ (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
+
+/*
+ * The following macros optimize certain frequently calculated
+ * quantities by using shifts and masks in place of divisions
+ * modulos and multiplications.
+ */
+#define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \
+ ((loc) & (fs)->fs_qbmask)
+#define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \
+ ((loc) & (fs)->fs_qfmask)
+#define lblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \
+ ((blk) << (fs)->fs_bshift)
+#define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \
+ ((loc) >> (fs)->fs_bshift)
+#define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \
+ ((loc) >> (fs)->fs_fshift)
+#define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \
+ (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
+#define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \
+ (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
+#define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \
+ ((frags) >> (fs)->fs_fragshift)
+#define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \
+ ((blks) << (fs)->fs_fragshift)
+#define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \
+ ((fsb) & ((fs)->fs_frag - 1))
+#define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \
+ ((fsb) &~ ((fs)->fs_frag - 1))
+
+/*
+ * Determine the number of available frags given a
+ * percentage to hold in reserve
+ */
+#define freespace(fs, percentreserved) \
+ (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
+ (fs)->fs_cstotal.cs_nffree - ((fs)->fs_dsize * (percentreserved) / 100))
+
+/*
+ * Determining the size of a file block in the file system.
+ */
+#define blksize(fs, ip, lbn) \
+ (((lbn) >= NDADDR || (ip)->i_size >= ((lbn) + 1) << (fs)->fs_bshift) \
+ ? (fs)->fs_bsize \
+ : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
+#define dblksize(fs, dip, lbn) \
+ (((lbn) >= NDADDR || (dip)->di_size >= ((lbn) + 1) << (fs)->fs_bshift) \
+ ? (fs)->fs_bsize \
+ : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
+
+/*
+ * Number of disk sectors per block; assumes DEV_BSIZE byte sector size.
+ */
+#define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift)
+#define NSPF(fs) ((fs)->fs_nspf)
+
+/*
+ * INOPB is the number of inodes in a secondary storage block.
+ */
+#define INOPB(fs) ((fs)->fs_inopb)
+#define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift)
+
+/*
+ * NINDIR is the number of indirects in a file system block.
+ */
+#define NINDIR(fs) ((fs)->fs_nindir)