From a9463ba8044f50ce55aa22ca3141d9398d6c317a Mon Sep 17 00:00:00 2001
From: Poul-Henning Kamp <phk@FreeBSD.org>
Date: Mon, 3 Mar 2003 11:14:36 +0000
Subject: [PATCH] Don't pick up a name from the dev_t if it is not there.

---
 sys/kern/subr_disk.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/sys/kern/subr_disk.c b/sys/kern/subr_disk.c
index 18f0cc7e6175..bc4a51327b75 100644
--- a/sys/kern/subr_disk.c
+++ b/sys/kern/subr_disk.c
@@ -32,7 +32,13 @@ disk_err(struct bio *bp, const char *what, int blkdone, int nl)
 {
 	daddr_t sn;
 
-	printf("%s: %s ", devtoname(bp->bio_dev), what);
+	if (bp->bio_dev != NULL)
+		printf("%s: %s ", devtoname(bp->bio_dev), what);
+	else if (bp->bio_disk != NULL)
+		printf("%s%d: %s ",
+		    bp->bio_disk->d_name, bp->bio_disk->d_unit, what);
+	else
+		printf("disk??: %s ", what);
 	switch(bp->bio_cmd) {
 	case BIO_READ:		printf("cmd=read "); break;
 	case BIO_WRITE:		printf("cmd=write "); break;