[SCSI] st: add MTWEOFI to write filemarks without flushing drive buffer
This patch adds a new MTIOCTOP operation MTWEOFI that writes filemarks with
immediate bit set. This means that the drive does not flush its buffer and the
next file can be started immediately. This speeds up writing in applications
that have to write multiple small files.
Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 24211d0..9e2c3a7 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -9,7 +9,7 @@
Steve Hirsch, Andreas Koppenh"ofer, Michael Leodolter, Eyal Lebedinsky,
Michael Schaefer, J"org Weule, and Eric Youngdale.
- Copyright 1992 - 2008 Kai Makisara
+ Copyright 1992 - 2010 Kai Makisara
email Kai.Makisara@kolumbus.fi
Some small formal changes - aeb, 950809
@@ -17,7 +17,7 @@
Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
*/
-static const char *verstr = "20081215";
+static const char *verstr = "20100829";
#include <linux/module.h>
@@ -2696,18 +2696,21 @@
}
break;
case MTWEOF:
+ case MTWEOFI:
case MTWSM:
if (STp->write_prot)
return (-EACCES);
cmd[0] = WRITE_FILEMARKS;
if (cmd_in == MTWSM)
cmd[1] = 2;
+ if (cmd_in == MTWEOFI)
+ cmd[1] |= 1;
cmd[2] = (arg >> 16);
cmd[3] = (arg >> 8);
cmd[4] = arg;
timeout = STp->device->request_queue->rq_timeout;
DEBC(
- if (cmd_in == MTWEOF)
+ if (cmd_in != MTWSM)
printk(ST_DEB_MSG "%s: Writing %d filemarks.\n", name,
cmd[2] * 65536 + cmd[3] * 256 + cmd[4]);
else
@@ -2883,8 +2886,8 @@
else if (chg_eof)
STps->eof = ST_NOEOF;
- if (cmd_in == MTWEOF)
- STps->rw = ST_IDLE;
+ if (cmd_in == MTWEOF || cmd_in == MTWEOFI)
+ STps->rw = ST_IDLE; /* prevent automatic WEOF at close */
} else { /* SCSI command was not completely successful. Don't return
from this block without releasing the SCSI command block! */
struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
@@ -2901,7 +2904,7 @@
else
undone = 0;
- if (cmd_in == MTWEOF &&
+ if ((cmd_in == MTWEOF || cmd_in == MTWEOFI) &&
cmdstatp->have_sense &&
(cmdstatp->flags & SENSE_EOM)) {
if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||