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authorTheo de Raadt <deraadt@cvs.openbsd.org>1995-10-18 08:53:40 +0000
committerTheo de Raadt <deraadt@cvs.openbsd.org>1995-10-18 08:53:40 +0000
commitd6583bb2a13f329cf0332ef2570eb8bb8fc0e39c (patch)
treeece253b876159b39c620e62b6c9b1174642e070e /sys/isofs/cd9660/cd9660_bmap.c
initial import of NetBSD tree
Diffstat (limited to 'sys/isofs/cd9660/cd9660_bmap.c')
-rw-r--r--sys/isofs/cd9660/cd9660_bmap.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/sys/isofs/cd9660/cd9660_bmap.c b/sys/isofs/cd9660/cd9660_bmap.c
new file mode 100644
index 00000000000..fdadd3ac028
--- /dev/null
+++ b/sys/isofs/cd9660/cd9660_bmap.c
@@ -0,0 +1,104 @@
+/* $NetBSD: cd9660_bmap.c,v 1.5 1994/12/13 22:33:12 mycroft Exp $ */
+
+/*-
+ * Copyright (c) 1994
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley
+ * by Pace Willisson (pace@blitz.com). The Rock Ridge Extension
+ * Support code is derived from software contributed to Berkeley
+ * by Atsushi Murai (amurai@spec.co.jp).
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * @(#)cd9660_bmap.c 8.4 (Berkeley) 12/5/94
+ */
+
+#include <sys/param.h>
+#include <sys/namei.h>
+#include <sys/buf.h>
+#include <sys/file.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+
+#include <isofs/cd9660/iso.h>
+#include <isofs/cd9660/cd9660_node.h>
+
+/*
+ * Bmap converts a the logical block number of a file to its physical block
+ * number on the disk. The conversion is done by using the logical block
+ * number to index into the data block (extent) for the file.
+ */
+int
+cd9660_bmap(ap)
+ struct vop_bmap_args /* {
+ struct vnode *a_vp;
+ daddr_t a_bn;
+ struct vnode **a_vpp;
+ daddr_t *a_bnp;
+ int *a_runp;
+ } */ *ap;
+{
+ struct iso_node *ip = VTOI(ap->a_vp);
+ daddr_t lblkno = ap->a_bn;
+ int bshift;
+
+ /*
+ * Check for underlying vnode requests and ensure that logical
+ * to physical mapping is requested.
+ */
+ if (ap->a_vpp != NULL)
+ *ap->a_vpp = ip->i_devvp;
+ if (ap->a_bnp == NULL)
+ return (0);
+
+ /*
+ * Compute the requested block number
+ */
+ bshift = ip->i_mnt->im_bshift;
+ *ap->a_bnp = (ip->iso_start + lblkno) << (bshift - DEV_BSHIFT);
+
+ /*
+ * Determine maximum number of readahead blocks following the
+ * requested block.
+ */
+ if (ap->a_runp) {
+ int nblk;
+
+ nblk = (ip->i_size >> bshift) - (lblkno + 1);
+ if (nblk <= 0)
+ *ap->a_runp = 0;
+ else if (nblk >= (MAXBSIZE >> bshift))
+ *ap->a_runp = (MAXBSIZE >> bshift) - 1;
+ else
+ *ap->a_runp = nblk;
+ }
+
+ return (0);
+}