From a49bdda8d20785f9ab3b211faa366d02cbd3ba03 Mon Sep 17 00:00:00 2001
From: krw <krw@openbsd.org>
Date: Tue, 27 Jul 2010 00:49:42 +0000
Subject: [PATCH] Align FFS filesystem start and end sectors so the start is on
 a bsize boundary and the end fills up the last bsize chunk.

Don't change the start sector if it is the first sector of the
OpenBSD portion of the disk.

Don't attempt to align on SUN_CYLCHECK architectures. They are
attempting a different alignment.

This is an attempt to ensure that FFS i/o's are aligned for optimal
performance on newer disks that lie about their sector size.
---
 sbin/disklabel/editor.c | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/sbin/disklabel/editor.c b/sbin/disklabel/editor.c
index 310bd934bc1..425525873a3 100644
--- a/sbin/disklabel/editor.c
+++ b/sbin/disklabel/editor.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: editor.c,v 1.240 2010/06/30 21:11:20 halex Exp $	*/
+/*	$OpenBSD: editor.c,v 1.241 2010/07/27 00:49:42 krw Exp $	*/
 
 /*
  * Copyright (c) 1997-2000 Todd C. Miller <Todd.Miller@courtesan.com>
@@ -521,7 +521,7 @@ editor_allocspace(struct disklabel *lp_org)
 	struct diskchunk *chunks;
 	daddr64_t secs, chunkstart, chunksize, cylsecs, totsecs, xtrasecs;
 	char **partmp;
-	int i, j, lastalloc, index = 0, fragsize;
+	int i, j, lastalloc, index = 0, fragsize, partno;
 	int64_t physmem;
 
 	/* How big is the OpenBSD portion of the disk?  */
@@ -589,6 +589,7 @@ again:
 				break;
 		if (j == MAXPARTITIONS)
 			return;
+		partno = j;
 		pp = &lp->d_partitions[j];
 		partmp = &mountpoints[j];
 		ap = &alloc[i];
@@ -672,6 +673,7 @@ cylinderalign:
 			pp->p_fstype = FS_SWAP;
 		else {
 			pp->p_fstype = FS_BSDFFS;
+			get_bsize(lp, partno);
 			free(*partmp);
 			if ((*partmp = strdup(ap->mp)) == NULL)
 				errx(4, "out of memory");
@@ -1962,17 +1964,19 @@ get_fsize(struct disklabel *lp, int partno)
 int
 get_bsize(struct disklabel *lp, int partno)
 {
-	u_int64_t ui, bsize, frag, fsize;
+	u_int64_t adj, ui, bsize, frag, fsize;
 	struct partition *pp = &lp->d_partitions[partno];
 
-	if (!expert || pp->p_fstype != FS_BSDFFS)
+	if (pp->p_fstype != FS_BSDFFS)
 		return (0);
 
 	/* Avoid dividing by zero... */
 	if (pp->p_fragblock == 0)
 		return(1);
 
-	bsize = DISKLABELV1_FFS_BSIZE(pp->p_fragblock);
+	if (!expert)
+		goto align;
+
 	fsize = DISKLABELV1_FFS_FSIZE(pp->p_fragblock);
 	frag = DISKLABELV1_FFS_FRAG(pp->p_fragblock);
 
@@ -2002,6 +2006,24 @@ get_bsize(struct disklabel *lp, int partno)
 			break;
 	}
 	pp->p_fragblock = DISKLABELV1_FFS_FRAGBLOCK(ui / frag, frag);
+
+align:
+#ifndef SUN_CYLCHECK
+	bsize = (DISKLABELV1_FFS_FRAG(pp->p_fragblock) *
+	    DISKLABELV1_FFS_FSIZE(pp->p_fragblock)) / lp->d_secsize;
+	if (DL_GETPOFFSET(pp) != starting_sector) {
+		/* Can't change offset of first partition. */
+		adj = bsize - (DL_GETPOFFSET(pp) % bsize);
+		if (adj != 0 && adj != bsize) {
+			DL_SETPOFFSET(pp, DL_GETPOFFSET(pp) + adj);
+			DL_SETPSIZE(pp, DL_GETPSIZE(pp) - adj);
+		}
+	}
+	/* Always align end. */
+	adj = (DL_GETPOFFSET(pp) + DL_GETPSIZE(pp)) % bsize;
+	if (adj > 0)
+		DL_SETPSIZE(pp, DL_GETPSIZE(pp) - adj);
+#endif
 	return(0);
 }
 
-- 
2.20.1