initial import of NetBSD tree

1 files changed, 219 insertions, 0 deletions

diff --git a/sys/kern/subr_disk.c b/sys/kern/subr_disk.c
new file mode 100644
index 00000000000..1fda3176a0e
--- /dev/null
+++ b/sys/kern/subr_disk.c
@@ -0,0 +1,219 @@
+/*	$NetBSD: subr_disk.c,v 1.13 1995/03/29 20:57:35 mycroft Exp $	*/
+
+/*
+ * Copyright (c) 1982, 1986, 1988, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * (c) UNIX System Laboratories, Inc.
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * 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.
+ *
+ *	@(#)ufs_disksubr.c	8.5 (Berkeley) 1/21/94
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/buf.h>
+#include <sys/disklabel.h>
+#include <sys/syslog.h>
+
+/*
+ * Seek sort for disks.  We depend on the driver which calls us using b_resid
+ * as the current cylinder number.
+ *
+ * The argument ap structure holds a b_actf activity chain pointer on which we
+ * keep two queues, sorted in ascending cylinder order.  The first queue holds
+ * those requests which are positioned after the current cylinder (in the first
+ * request); the second holds requests which came in after their cylinder number
+ * was passed.  Thus we implement a one way scan, retracting after reaching the
+ * end of the drive to the first request on the second queue, at which time it
+ * becomes the first queue.
+ *
+ * A one-way scan is natural because of the way UNIX read-ahead blocks are
+ * allocated.
+ */
+
+void
+disksort(ap, bp)
+	register struct buf *ap, *bp;
+{
+	register struct buf *bq;
+
+	/* If the queue is empty, then it's easy. */
+	if (ap->b_actf == NULL) {
+		bp->b_actf = NULL;
+		ap->b_actf = bp;
+		return;
+	}
+
+	/*
+	 * If we lie after the first (currently active) request, then we
+	 * must locate the second request list and add ourselves to it.
+	 */
+	bq = ap->b_actf;
+	if (bp->b_cylinder < bq->b_cylinder) {
+		while (bq->b_actf) {
+			/*
+			 * Check for an ``inversion'' in the normally ascending
+			 * cylinder numbers, indicating the start of the second
+			 * request list.
+			 */
+			if (bq->b_actf->b_cylinder < bq->b_cylinder) {
+				/*
+				 * Search the second request list for the first
+				 * request at a larger cylinder number.  We go
+				 * before that; if there is no such request, we
+				 * go at end.
+				 */
+				do {
+					if (bp->b_cylinder <
+					    bq->b_actf->b_cylinder)
+						goto insert;
+					if (bp->b_cylinder ==
+					    bq->b_actf->b_cylinder &&
+					    bp->b_blkno < bq->b_actf->b_blkno)
+						goto insert;
+					bq = bq->b_actf;
+				} while (bq->b_actf);
+				goto insert;		/* after last */
+			}
+			bq = bq->b_actf;
+		}
+		/*
+		 * No inversions... we will go after the last, and
+		 * be the first request in the second request list.
+		 */
+		goto insert;
+	}
+	/*
+	 * Request is at/after the current request...
+	 * sort in the first request list.
+	 */
+	while (bq->b_actf) {
+		/*
+		 * We want to go after the current request if there is an
+		 * inversion after it (i.e. it is the end of the first
+		 * request list), or if the next request is a larger cylinder
+		 * than our request.
+		 */
+		if (bq->b_actf->b_cylinder < bq->b_cylinder ||
+		    bp->b_cylinder < bq->b_actf->b_cylinder ||
+		    (bp->b_cylinder == bq->b_actf->b_cylinder &&
+		    bp->b_blkno < bq->b_actf->b_blkno))
+			goto insert;
+		bq = bq->b_actf;
+	}
+	/*
+	 * Neither a second list nor a larger request... we go at the end of
+	 * the first list, which is the same as the end of the whole schebang.
+	 */
+insert:	bp->b_actf = bq->b_actf;
+	bq->b_actf = bp;
+}
+
+/* encoding of disk minor numbers, should be elsewhere... */
+#define dkunit(dev)		(minor(dev) >> 3)
+#define dkpart(dev)		(minor(dev) & 07)
+#define dkminor(unit, part)	(((unit) << 3) | (part))
+
+/*
+ * Compute checksum for disk label.
+ */
+u_int
+dkcksum(lp)
+	register struct disklabel *lp;
+{
+	register u_short *start, *end;
+	register u_short sum = 0;
+
+	start = (u_short *)lp;
+	end = (u_short *)&lp->d_partitions[lp->d_npartitions];
+	while (start < end)
+		sum ^= *start++;
+	return (sum);
+}
+
+/*
+ * Disk error is the preface to plaintive error messages
+ * about failing disk transfers.  It prints messages of the form
+
+hp0g: hard error reading fsbn 12345 of 12344-12347 (hp0 bn %d cn %d tn %d sn %d)
+
+ * if the offset of the error in the transfer and a disk label
+ * are both available.  blkdone should be -1 if the position of the error
+ * is unknown; the disklabel pointer may be null from drivers that have not
+ * been converted to use them.  The message is printed with printf
+ * if pri is LOG_PRINTF, otherwise it uses log at the specified priority.
+ * The message should be completed (with at least a newline) with printf
+ * or addlog, respectively.  There is no trailing space.
+ */
+void
+diskerr(bp, dname, what, pri, blkdone, lp)
+	register struct buf *bp;
+	char *dname, *what;
+	int pri, blkdone;
+	register struct disklabel *lp;
+{
+	int unit = dkunit(bp->b_dev), part = dkpart(bp->b_dev);
+	register void (*pr) __P((const char *, ...));
+	char partname = 'a' + part;
+	int sn;
+
+	if (pri != LOG_PRINTF) {
+		log(pri, "");
+		pr = addlog;
+	} else
+		pr = printf;
+	(*pr)("%s%d%c: %s %sing fsbn ", dname, unit, partname, what,
+	    bp->b_flags & B_READ ? "read" : "writ");
+	sn = bp->b_blkno;
+	if (bp->b_bcount <= DEV_BSIZE)
+		(*pr)("%d", sn);
+	else {
+		if (blkdone >= 0) {
+			sn += blkdone;
+			(*pr)("%d of ", sn);
+		}
+		(*pr)("%d-%d", bp->b_blkno,
+		    bp->b_blkno + (bp->b_bcount - 1) / DEV_BSIZE);
+	}
+	if (lp && (blkdone >= 0 || bp->b_bcount <= lp->d_secsize)) {
+#ifdef tahoe
+		sn *= DEV_BSIZE / lp->d_secsize;		/* XXX */
+#endif
+		sn += lp->d_partitions[part].p_offset;
+		(*pr)(" (%s%d bn %d; cn %d", dname, unit, sn,
+		    sn / lp->d_secpercyl);
+		sn %= lp->d_secpercyl;
+		(*pr)(" tn %d sn %d)", sn / lp->d_nsectors, sn % lp->d_nsectors);
+	}
+}