As first brought to my attention by Russel Sutherland, our deletion of

the mt_fileno and mt_blkno fields from the mtget struct was too hasty.

Subsequent discussions with Kern Sibbold of the Bacula project
revealed these are widely used by tape backup software on many
unicies. The de facto standard is to return -1 if you can't determine
the value.

So add them back and always return -1 as their value. Should allow
Bacula and similar software to at least compile while we investigate
providing meaningful values.

ok beck@

2 files changed, 6 insertions, 2 deletions

diff --git a/sys/scsi/st.c b/sys/scsi/st.c
index 810e420c3ec..99bba3b8438 100644
--- a/sys/scsi/st.c
+++ b/sys/scsi/st.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: st.c,v 1.70 2006/12/21 02:05:46 krw Exp $	*/
+/*	$OpenBSD: st.c,v 1.71 2007/01/05 00:42:47 krw Exp $	*/
 /*	$NetBSD: st.c,v 1.71 1997/02/21 23:03:49 thorpej Exp $	*/
 
 /*
@@ -1076,6 +1076,8 @@ stioctl(dev, cmd, arg, flag, p)
 			g->mt_dsreg |= MT_DS_MOUNTED;
 		g->mt_resid = st->mt_resid;
 		g->mt_erreg = st->mt_erreg;
+		g->mt_fileno = -1;	/* -1 means we don't know */
+		g->mt_blkno = -1;	/* -1 means we don't know */
 		/*
 		 * clear latched errors.
 		 */
diff --git a/sys/sys/mtio.h b/sys/sys/mtio.h
index 4517e64d6e0..e2e57e97307 100644
--- a/sys/sys/mtio.h
+++ b/sys/sys/mtio.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mtio.h,v 1.7 2006/06/01 05:42:01 krw Exp $	*/
+/*	$OpenBSD: mtio.h,v 1.8 2007/01/05 00:42:47 krw Exp $	*/
 /*	$NetBSD: mtio.h,v 1.14 1997/04/15 06:50:19 lukem Exp $	*/
 
 /*
@@ -72,6 +72,8 @@ struct mtget {
 	short	mt_erreg;	/* ``error'' register */
 /* end device-dependent registers */
 	short	mt_resid;	/* residual count */
+	daddr_t mt_fileno;	/* current file number relative to BOT. */ 
+	daddr_t mt_blkno;	/* current block number relative to BOF. */
 	daddr_t	mt_blksiz;	/* current block size */
 	daddr_t	mt_density;	/* current density code */
 	daddr_t	mt_mblksiz;	/* default block size */