165789Smckusick /*- 265789Smckusick * Copyright (c) 1994 365789Smckusick * The Regents of the University of California. All rights reserved. 465789Smckusick * 565789Smckusick * This code is derived from software contributed to Berkeley 665789Smckusick * by Pace Willisson (pace@blitz.com). The Rock Ridge Extension 765789Smckusick * Support code is derived from software contributed to Berkeley 865789Smckusick * by Atsushi Murai (amurai@spec.co.jp). 965789Smckusick * 1065789Smckusick * %sccs.include.redist.c% 1165789Smckusick * 12*65855Smckusick * @(#)cd9660_bmap.c 8.3 (Berkeley) 01/23/94 1365789Smckusick */ 1465789Smckusick 1565789Smckusick #include <sys/param.h> 1665789Smckusick #include <sys/namei.h> 1765789Smckusick #include <sys/buf.h> 1865789Smckusick #include <sys/file.h> 1965789Smckusick #include <sys/vnode.h> 2065789Smckusick #include <sys/mount.h> 2165789Smckusick 2265789Smckusick #include <isofs/cd9660/iso.h> 23*65855Smckusick #include <isofs/cd9660/cd9660_node.h> 2465789Smckusick 2565789Smckusick /* 2665789Smckusick * Bmap converts a the logical block number of a file to its physical block 2765789Smckusick * number on the disk. The conversion is done by using the logical block 2865789Smckusick * number to index into the data block (extent) for the file. 2965789Smckusick */ 3065789Smckusick int 31*65855Smckusick cd9660_bmap(ap) 3265789Smckusick struct vop_bmap_args /* { 3365789Smckusick struct vnode *a_vp; 3465789Smckusick daddr_t a_bn; 3565789Smckusick struct vnode **a_vpp; 3665789Smckusick daddr_t *a_bnp; 3765789Smckusick int *a_runp; 3865789Smckusick } */ *ap; 3965789Smckusick { 4065789Smckusick struct iso_node *ip = VTOI(ap->a_vp); 4165789Smckusick daddr_t lblkno = ap->a_bn; 4265789Smckusick long bsize; 4365789Smckusick 4465789Smckusick /* 4565789Smckusick * Check for underlying vnode requests and ensure that logical 4665789Smckusick * to physical mapping is requested. 4765789Smckusick */ 4865789Smckusick if (ap->a_vpp != NULL) 4965789Smckusick *ap->a_vpp = ip->i_devvp; 5065789Smckusick if (ap->a_bnp == NULL) 5165789Smckusick return (0); 5265789Smckusick 5365789Smckusick /* 5465789Smckusick * Compute the requested block number 5565789Smckusick */ 5665789Smckusick bsize = ip->i_mnt->logical_block_size; 5765789Smckusick *ap->a_bnp = (ip->iso_start + lblkno) * btodb(bsize); 5865789Smckusick 5965789Smckusick /* 6065789Smckusick * Determine maximum number of readahead blocks following the 6165789Smckusick * requested block. 6265789Smckusick */ 6365789Smckusick if (ap->a_runp) { 6465789Smckusick int nblk; 6565789Smckusick 6665789Smckusick nblk = (ip->i_size - (lblkno + 1) * bsize) / bsize; 6765789Smckusick if (nblk <= 0) 6865789Smckusick *ap->a_runp = 0; 6965789Smckusick else if (nblk >= MAXBSIZE/bsize) 7065789Smckusick *ap->a_runp = MAXBSIZE/bsize - 1; 7165789Smckusick else 7265789Smckusick *ap->a_runp = nblk; 7365789Smckusick } 7465789Smckusick 7565789Smckusick return 0; 7665789Smckusick } 77