BSD 4.4 Lite Kernel Sources

1 files changed, 102 insertions, 0 deletions

diff --git a/sys/isofs/cd9660/cd9660_bmap.c b/sys/isofs/cd9660/cd9660_bmap.c
new file mode 100644
index 0000000..911eedf
--- /dev/null
+++ b/sys/isofs/cd9660/cd9660_bmap.c
@@ -0,0 +1,102 @@
+/*-
+ * 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	8.3 (Berkeley) 1/23/94
+ */
+
+#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;
+	long bsize;
+
+	/*
+	 * 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
+	 */
+	bsize = ip->i_mnt->logical_block_size;
+	*ap->a_bnp = (ip->iso_start + lblkno) * btodb(bsize);
+
+	/*
+	 * Determine maximum number of readahead blocks following the
+	 * requested block.
+	 */
+	if (ap->a_runp) {
+		int nblk;
+
+		nblk = (ip->i_size - (lblkno + 1) * bsize) / bsize;
+		if (nblk <= 0)
+			*ap->a_runp = 0;
+		else if (nblk >= MAXBSIZE/bsize)
+			*ap->a_runp = MAXBSIZE/bsize - 1;
+		else
+			*ap->a_runp = nblk;
+	}
+
+	return 0;
+}