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-rw-r--r--Documentation/scsi/st.txt15
-rw-r--r--drivers/scsi/st.c15
-rw-r--r--include/linux/mtio.h1
3 files changed, 24 insertions, 7 deletions
diff --git a/Documentation/scsi/st.txt b/Documentation/scsi/st.txt
index 4075260..691ca29 100644
--- a/Documentation/scsi/st.txt
+++ b/Documentation/scsi/st.txt
@@ -2,7 +2,7 @@ This file contains brief information about the SCSI tape driver.
The driver is currently maintained by Kai Mäkisara (email
Kai.Makisara@kolumbus.fi)
-Last modified: Sun Feb 24 21:59:07 2008 by kai.makisara
+Last modified: Sun Aug 29 18:25:47 2010 by kai.makisara
BASICS
@@ -85,6 +85,17 @@ writing and the last operation has been a write. Two filemarks can be
optionally written. In both cases end of data is signified by
returning zero bytes for two consecutive reads.
+Writing filemarks without the immediate bit set in the SCSI command block acts
+as a synchronization point, i.e., all remaining data form the drive buffers is
+written to tape before the command returns. This makes sure that write errors
+are caught at that point, but this takes time. In some applications, several
+consecutive files must be written fast. The MTWEOFI operation can be used to
+write the filemarks without flushing the drive buffer. Writing filemark at
+close() is always flushing the drive buffers. However, if the previous
+operation is MTWEOFI, close() does not write a filemark. This can be used if
+the program wants to close/open the tape device between files and wants to
+skip waiting.
+
If rewind, offline, bsf, or seek is done and previous tape operation was
write, a filemark is written before moving tape.
@@ -301,6 +312,8 @@ MTBSR Space backward over count records.
MTFSS Space forward over count setmarks.
MTBSS Space backward over count setmarks.
MTWEOF Write count filemarks.
+MTWEOFI Write count filemarks with immediate bit set (i.e., does not
+ wait until data is on tape)
MTWSM Write count setmarks.
MTREW Rewind tape.
MTOFFL Set device off line (often rewind plus eject).
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 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
}
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 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
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 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
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 ||
diff --git a/include/linux/mtio.h b/include/linux/mtio.h
index ef01d6a..8f82575 100644
--- a/include/linux/mtio.h
+++ b/include/linux/mtio.h
@@ -63,6 +63,7 @@ struct mtop {
#define MTCOMPRESSION 32/* control compression with SCSI mode page 15 */
#define MTSETPART 33 /* Change the active tape partition */
#define MTMKPART 34 /* Format the tape with one or two partitions */
+#define MTWEOFI 35 /* write an end-of-file record (mark) in immediate mode */
/* structure for MTIOCGET - mag tape get status command */