>From 6d0f1d306660c645d72f8e1543ce0bebc719f10b Mon Sep 17 00:00:00 2001
From: Hannes Reinecke <hare@suse.de>
Date: Sun, 2 Feb 2014 12:03:09 +0100
Subject: [PATCH] st: Implement MT_ST_NOREWIND option

This patch implements the MT_ST_NOREWIND option to inhibit the
rewind on close setting even on normal 'st' devices.
With this patch programs like sg_inq can retrieve the device
identification without interrupting the current operation.

Signed-off-by: Hannes Reinecke <hare@suse.de>

diff --git a/Documentation/scsi/st.txt b/Documentation/scsi/st.txt
index f346abb..93906d0 100644
--- a/Documentation/scsi/st.txt
+++ b/Documentation/scsi/st.txt
@@ -399,6 +399,8 @@ MTSETDRVBUFFER
 		correctly returns transfer residuals
 	     MT_ST_DEBUGGING debugging (global; debugging must be
 		compiled into the driver)
+	     MT_ST_NOREWIND disable rewind-on-close even on autorewind
+	        tape devices
 	MT_ST_SETBOOLEANS
 	MT_ST_CLEARBOOLEANS
 	   Sets or clears the option bits.
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index a1d6986..f550d0d 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -2228,6 +2228,8 @@ static int st_set_options(struct scsi_tape *STp, long options)
 		STp->immediate_filemark = (options & MT_ST_NOWAIT_EOF) != 0;
 		STm->sysv = (options & MT_ST_SYSV) != 0;
 		STp->sili = (options & MT_ST_SILI) != 0;
+		if (options & MT_ST_NOREWIND)
+			STp->rew_at_close = 0; 
 		DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
 		     st_log_options(STp, STm, name); )
 	} else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) {
@@ -2263,6 +2265,8 @@ static int st_set_options(struct scsi_tape *STp, long options)
 			STm->sysv = value;
 		if ((options & MT_ST_SILI) != 0)
 			STp->sili = value;
+		if (value && (options & MT_ST_NOREWIND) != 0)
+			Stp->rew_at_close = 0;
                 DEB(
 		if ((options & MT_ST_DEBUGGING) != 0)
 			debugging = value;
diff --git a/include/uapi/linux/mtio.h b/include/uapi/linux/mtio.h
index 18543e2..e8b0417 100644
--- a/include/uapi/linux/mtio.h
+++ b/include/uapi/linux/mtio.h
@@ -195,6 +195,7 @@ struct	mtpos {
 #define MT_ST_NOWAIT            0x2000
 #define MT_ST_SILI		0x4000
 #define MT_ST_NOWAIT_EOF	0x8000
+#define MT_ST_NOREWIND		0x10000
 
 /* The mode parameters to be controlled. Parameter chosen with bits 20-28 */
 #define MT_ST_CLEAR_DEFAULT	0xfffff