diff mbox

st driver doesn't seem to grok LTO partitioning

Message ID alpine.LSU.2.11.1512301947150.1713@xnv.znxvfnen.cevingr (mailing list archive)
State Superseded, archived
Headers show

Commit Message

Kai Mäkisara Dec. 30, 2015, 5:54 p.m. UTC 
On Tuesday 2015-12-29 20:13, Emmanuel Florac wrote:

...
>It works when providing the size :
>
># mt -f /dev/nst0  mkpartition 36764
>
Good.

I think I found out why it did not work with the default format. At the 
end of this message you find a new patch that should correct that. There 
are also other changes:
- some changes when specifying the size in the mode page; needed for the
  IBM 3592 drives but should not change results with LTO
- formatting with one partition is done directly with FORMAT MEDIUM if
  the drive requires that command
- some other bugs fixed

Thanks for testing,
Kai

-----------------------------------8<------------------------------------
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Comments

Emmanuel Florac Dec. 30, 2015, 6:33 p.m. UTC | #1 
Le Wed, 30 Dec 2015 19:54:01 +0200 (EET)
Kai Makisara <Kai.Makisara@kolumbus.fi> écrivait:

> I think I found out why it did not work with the default format. At
> the end of this message you find a new patch that should correct
> that. There are also other changes:
> - some changes when specifying the size in the mode page; needed for
> the IBM 3592 drives but should not change results with LTO
> - formatting with one partition is done directly with FORMAT MEDIUM if
>   the drive requires that command
> - some other bugs fixed

Hum, I can't seem to be able to go back to 1 partition, or to reformat
the tape (didn't change it since yesterday), am I missing something?

Dec 30 19:21:29 shakuhachi kernel: st: Version 20151230, fixed bufsize 32768, s/g segs 256
Dec 30 19:21:29 shakuhachi kernel: st 7:0:0:0: Attached scsi tape st0
Dec 30 19:21:29 shakuhachi kernel: st 7:0:0:0: st0: try direct i/o: yes (alignment 512 B)

~# mt -f /dev/nst0  mkpartition 0

Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Block limits 1 - 16777215 bytes.
Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Mode sense. Length 11, medium 0, WBS 10, BLL 8
Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Density 5a, tape length: 0, drv buffer: 1
Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Block size: 0, buffer size: 4096 (1 blocks).
Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Rewinding tape.
Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Partition page length is 16 bytes.
Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: PP: max 3, add 1, xdp 1, psum 03, pofmetc 4, rec 03, units 09, sizes: 2543 38
Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Sending FORMAT MEDIUM
Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Error: 8000002, cmd: 4 0 0 0 0 0
Dec 30 19:24:41 shakuhachi kernel: st0: Sense Key : Illegal Request [current] 
Dec 30 19:24:41 shakuhachi kernel: st0: Add. Sense: Position past beginning of medium

~# mt -f /dev/nst0  mkpartition 1

Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Block limits 1 - 16777215 bytes.
Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Mode sense. Length 11, medium 0, WBS 10, BLL 8
Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Density 5a, tape length: 0, drv buffer: 1
Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Block size: 0, buffer size: 4096 (1 blocks).
Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Rewinding tape.
Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Partition page length is 16 bytes.
Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: PP: max 3, add 1, xdp 1, psum 03, pofmetc 4, rec 03, units 09, sizes: 2543 38
Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: psd_cnt 2, max.parts 3, nbr_parts 1
Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Formatting tape with two partitions (FDP).
Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Sent partition page length is 12 bytes. needs_format: 1
Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: PP: max 3, add 1, xdp 4, psum 00, pofmetc 4, rec 03, units 00, sizes: 65535 0
Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Error: 8000002, cmd: 15 10 0 0 18 0
Dec 30 19:26:12 shakuhachi kernel: st0: Sense Key : Illegal Request [current] 
Dec 30 19:26:12 shakuhachi kernel: st0: Add. Sense: Invalid field in parameter list
Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Partitioning of tape failed.
Kai Mäkisara Dec. 30, 2015, 7:21 p.m. UTC | #2 
> On 30.12.2015, at 20.33, Emmanuel Florac <eflorac@intellique.com> wrote:
> 
> Le Wed, 30 Dec 2015 19:54:01 +0200 (EET)
> Kai Makisara <Kai.Makisara@kolumbus.fi> écrivait:
> 
>> I think I found out why it did not work with the default format. At
>> the end of this message you find a new patch that should correct
>> that. There are also other changes:
>> - some changes when specifying the size in the mode page; needed for
>> the IBM 3592 drives but should not change results with LTO
>> - formatting with one partition is done directly with FORMAT MEDIUM if
>>  the drive requires that command
>> - some other bugs fixed
> 
> Hum, I can't seem to be able to go back to 1 partition, or to reformat
> the tape (didn't change it since yesterday), am I missing something?
> 
> Dec 30 19:21:29 shakuhachi kernel: st: Version 20151230, fixed bufsize 32768, s/g segs 256
> Dec 30 19:21:29 shakuhachi kernel: st 7:0:0:0: Attached scsi tape st0
> Dec 30 19:21:29 shakuhachi kernel: st 7:0:0:0: st0: try direct i/o: yes (alignment 512 B)
> 
> ~# mt -f /dev/nst0  mkpartition 0
> 
> Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Block limits 1 - 16777215 bytes.
> Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Mode sense. Length 11, medium 0, WBS 10, BLL 8
> Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Density 5a, tape length: 0, drv buffer: 1
> Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Block size: 0, buffer size: 4096 (1 blocks).
> Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Rewinding tape.
> Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Partition page length is 16 bytes.
> Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: PP: max 3, add 1, xdp 1, psum 03, pofmetc 4, rec 03, units 09, sizes: 2543 38
> Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Sending FORMAT MEDIUM
> Dec 30 19:24:41 shakuhachi kernel: st 7:0:0:0: st0: Error: 8000002, cmd: 4 0 0 0 0 0
> Dec 30 19:24:41 shakuhachi kernel: st0: Sense Key : Illegal Request [current] 
> Dec 30 19:24:41 shakuhachi kernel: st0: Add. Sense: Position past beginning of medium

This happens if the position is not at the beginning of partition 0. Could you try
to switch to partition 0:
mt -f /dev/nst0 setpartition 0
mt -f /dev/nst0 status

and the retry partitioning.

> ~# mt -f /dev/nst0  mkpartition 1
> 
> Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Block limits 1 - 16777215 bytes.
> Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Mode sense. Length 11, medium 0, WBS 10, BLL 8
> Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Density 5a, tape length: 0, drv buffer: 1
> Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Block size: 0, buffer size: 4096 (1 blocks).
> Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Rewinding tape.
> Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Partition page length is 16 bytes.
> Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: PP: max 3, add 1, xdp 1, psum 03, pofmetc 4, rec 03, units 09, sizes: 2543 38
> Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: psd_cnt 2, max.parts 3, nbr_parts 1
> Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Formatting tape with two partitions (FDP).
> Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Sent partition page length is 12 bytes. needs_format: 1
> Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: PP: max 3, add 1, xdp 4, psum 00, pofmetc 4, rec 03, units 00, sizes: 65535 0
> Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Error: 8000002, cmd: 15 10 0 0 18 0
> Dec 30 19:26:12 shakuhachi kernel: st0: Sense Key : Illegal Request [current] 
> Dec 30 19:26:12 shakuhachi kernel: st0: Add. Sense: Invalid field in parameter list
> Dec 30 19:26:12 shakuhachi kernel: st 7:0:0:0: st0: Partitioning of tape failed.
> 
I have to recheck what it set into the mode page. It is still not correct in this case.

Kai

--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Emmanuel Florac Dec. 30, 2015, 9:24 p.m. UTC | #3 
Le Wed, 30 Dec 2015 21:21:47 +0200
"Kai Mäkisara (Kolumbus)" <kai.makisara@kolumbus.fi> écrivait:

> This happens if the position is not at the beginning of partition 0.
> Could you try to switch to partition 0:
> mt -f /dev/nst0 setpartition 0
> mt -f /dev/nst0 status
> 
> and the retry partitioning.

Alas, no dice:

# mt -f /dev/nst0 setpartition 0


Dec 30 22:19:33 shakuhachi kernel: st 7:0:0:0: st0: Block limits 1 - 16777215 bytes.
Dec 30 22:19:33 shakuhachi kernel: st 7:0:0:0: st0: Mode sense. Length 11, medium 0, WBS 10, BLL 8
Dec 30 22:19:33 shakuhachi kernel: st 7:0:0:0: st0: Density 5a, tape length: 0, drv buffer: 1
Dec 30 22:19:33 shakuhachi kernel: st 7:0:0:0: st0: Block size: 0, buffer size: 4096 (1 blocks).

# mt -f /dev/nst0 status
SCSI 2 tape drive:
File number=0, block number=0, partition=0.
Tape block size 0 bytes. Density code 0x5a (no translation).
Soft error count since last status=0
General status bits on (41010000):
 BOT ONLINE IM_REP_EN

Dec 30 22:19:49 shakuhachi kernel: st 7:0:0:0: st0: Block limits 1 - 16777215 bytes.
Dec 30 22:19:49 shakuhachi kernel: st 7:0:0:0: st0: Mode sense. Length 11, medium 0, WBS 10, BLL 8
Dec 30 22:19:49 shakuhachi kernel: st 7:0:0:0: st0: Density 5a, tape length: 0, drv buffer: 1
Dec 30 22:19:49 shakuhachi kernel: st 7:0:0:0: st0: Block size: 0, buffer size: 4096 (1 blocks).

# mt -f /dev/nst0 mkpartition 0

Dec 30 22:22:21 shakuhachi kernel: st 7:0:0:0: st0: Block limits 1 - 16777215 bytes.
Dec 30 22:22:21 shakuhachi kernel: st 7:0:0:0: st0: Mode sense. Length 11, medium 0, WBS 10, BLL 8
Dec 30 22:22:21 shakuhachi kernel: st 7:0:0:0: st0: Density 5a, tape length: 0, drv buffer: 1
Dec 30 22:22:21 shakuhachi kernel: st 7:0:0:0: st0: Block size: 0, buffer size: 4096 (1 blocks).
Dec 30 22:22:21 shakuhachi kernel: st 7:0:0:0: st0: Rewinding tape.
Dec 30 22:22:21 shakuhachi kernel: st 7:0:0:0: st0: Partition page length is 16 bytes.
Dec 30 22:22:21 shakuhachi kernel: st 7:0:0:0: st0: PP: max 3, add 1, xdp 1, psum 03, pofmetc 4, rec 03, units 09, sizes: 2543 38
Dec 30 22:22:21 shakuhachi kernel: st 7:0:0:0: st0: Sending FORMAT MEDIUM
Dec 30 22:22:21 shakuhachi kernel: st 7:0:0:0: st0: Error: 8000002, cmd: 4 0 0 0 0 0
Dec 30 22:22:21 shakuhachi kernel: st0: Sense Key : Illegal Request [current] 
Dec 30 22:22:21 shakuhachi kernel: st0: Add. Sense: Position past beginning of medium
Kai Mäkisara Dec. 31, 2015, 4:08 p.m. UTC | #4 
> On 30.12.2015, at 23.24, Emmanuel Florac <eflorac@intellique.com> wrote:
> 
> Le Wed, 30 Dec 2015 21:21:47 +0200
> "Kai Mäkisara (Kolumbus)" <kai.makisara@kolumbus.fi> écrivait:
> 
>> This happens if the position is not at the beginning of partition 0.
>> Could you try to switch to partition 0:
>> mt -f /dev/nst0 setpartition 0
>> mt -f /dev/nst0 status
>> 
>> and the retry partitioning.
> 
> Alas, no dice:
> 
OK.

In the HP LTFS sources I found an interesting detail: the code does LOAD before unformatting.
A comment says that it is in some cases better method to put the position to beginning of
partition 0 than other methods. You could try ‘mt load’ before trying to partition.

Kai

--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

--- ref/drivers/scsi/st.c	2015-12-21 18:54:05.068882001 +0200
+++ new/drivers/scsi/st.c	2015-12-30 19:30:37.900152216 +0200
@@ -9,7 +9,7 @@ 
    Steve Hirsch, Andreas Koppenh"ofer, Michael Leodolter, Eyal Lebedinsky,
    Michael Schaefer, J"org Weule, and Eric Youngdale.
 
-   Copyright 1992 - 2010 Kai Makisara
+   Copyright 1992 - 2016 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 = "20101219";
+static const char *verstr = "20151230";
 
 #include <linux/module.h>
 
@@ -3296,7 +3296,10 @@ 
 #define PP_OFF_RESERVED        7
 
 #define PP_BIT_IDP             0x20
+#define PP_BIT_FDP             0x80
 #define PP_MSK_PSUM_MB         0x10
+#define PP_MSK_PSUM_UNITS      0x18
+#define PP_MSK_POFM            0x04
 
 /* Get the number of partitions on the tape. As a side effect reads the
    mode page into the tape buffer. */
@@ -3322,6 +3325,29 @@ 
 }
 
 
+static int format_medium(struct scsi_tape *STp, int format)
+{
+	int result = 0;
+	int timeout = STp->long_timeout;
+	unsigned char scmd[MAX_COMMAND_SIZE];
+	struct st_request *SRpnt;
+
+	memset(scmd, 0, MAX_COMMAND_SIZE);
+	scmd[0] = FORMAT_UNIT;
+	scmd[2] = format;
+	if (STp->immediate) {
+		scmd[1] |= 1;		/* Don't wait for completion */
+		timeout = STp->device->request_queue->rq_timeout;
+	}
+	DEBC_printk(STp, "Sending FORMAT MEDIUM\n");
+	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
+			   timeout, MAX_RETRIES, 1);
+	if (!SRpnt)
+		result = STp->buffer->syscall_result;
+	return result;
+}
+
+
 /* Partition the tape into two partitions if size > 0 or one partition if
    size == 0.
 
@@ -3340,11 +3366,15 @@ 
    and 10 when 1 partition is defined (information from Eric Lee Green). This is
    is acceptable also to some other old drives and enforced if the first partition
    size field is used for the first additional partition size.
+
+   For drives that advertize SCSI-3 or newer, use the SSC-3 methods.
  */
 static int partition_tape(struct scsi_tape *STp, int size)
 {
 	int result;
+	bool scsi3 = STp->device->scsi_level >= SCSI_3,  needs_format = false;
 	int pgo, psd_cnt, psdo;
+	int psum = PP_MSK_PSUM_MB, units = 0;
 	unsigned char *bp;
 
 	result = read_mode_page(STp, PART_PAGE, 0);
@@ -3357,11 +3387,54 @@ 
 	pgo = MODE_HEADER_LENGTH + bp[MH_OFF_BDESCS_LENGTH];
 	DEBC_printk(STp, "Partition page length is %d bytes.\n",
 		    bp[pgo + MP_OFF_PAGE_LENGTH] + 2);
+	DEBC_printk(STp, "PP: max %u, add %u, xdp %u, psum %02x, pofmetc %u, "
+		    "rec %02x, units %02x, sizes: %u %u\n",
+		    bp[pgo + PP_OFF_MAX_ADD_PARTS],
+		    bp[pgo + PP_OFF_NBR_ADD_PARTS],
+		    (bp[pgo + PP_OFF_FLAGS] & 0xe0) >> 5,
+		    (bp[pgo + PP_OFF_FLAGS] & 0x18) >> 3,
+		    bp[pgo + PP_OFF_FLAGS] & 0x07,
+		    bp[pgo + 5],
+		    bp[pgo + PP_OFF_PART_UNITS],
+		    bp[pgo + 8] * 256 + bp[pgo + 9],
+		    bp[pgo + 10] * 256 + bp[pgo + 11]);
+
+	if (scsi3) {
+		needs_format = (bp[pgo + PP_OFF_FLAGS] & PP_MSK_POFM) != 0;
+		if (needs_format && size == 0) {
+			result = format_medium(STp, 0);
+			goto out;
+		}
+
+		psd_cnt = size > 0 ? 2 : 1;
+		if ((bp[pgo + PP_OFF_FLAGS] & PP_MSK_PSUM_UNITS) == PP_MSK_PSUM_UNITS) {
+			/* Use units scaling for large partitions if the device suggests
+			   it and no precision lost. Required for IBM TS1140/50 drives
+			   that don't support MB units. */
+			if (size >= 1000 && (size % 1000) == 0) {
+				size /= 1000;
+				psum = PP_MSK_PSUM_UNITS;
+				units = 9; /* GB */
+			}
+		}
+		/* Try it anyway if too large to specify in MB */
+		if (psum == PP_MSK_PSUM_MB && size >= 65534) {
+				size /= 1000;
+				psum = PP_MSK_PSUM_UNITS;
+				units = 9;  /* GB */
+		}
+	} else
+		psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 -
+			   PART_PAGE_FIXED_LENGTH) / 2;
+
+	if (size >= 65534) { /* Does not fit into two bytes */
+		result = -EINVAL;
+		goto out;
+	}
 
-	psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 - PART_PAGE_FIXED_LENGTH) / 2;
 	psdo = pgo + PART_PAGE_FIXED_LENGTH;
-	if (psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS]) {
-		bp[psdo] = bp[psdo + 1] = 0xff;  /* Rest of the tape */
+	if (scsi3 || psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS]) {
+		bp[psdo] = bp[psdo + 1] = 0xff;  /* Rest of the tape to partition 0 */
 		psdo += 2;
 	}
 	memset(bp + psdo, 0, bp[pgo + PP_OFF_NBR_ADD_PARTS] * 2);
@@ -3375,6 +3448,11 @@ 
 		if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS])
 		    bp[pgo + MP_OFF_PAGE_LENGTH] = 6;
 		DEBC_printk(STp, "Formatting tape with one partition.\n");
+	} else if (size == 1 && units == 0) {
+		bp[pgo + PP_OFF_NBR_ADD_PARTS] = 1;
+		if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS])
+		    bp[pgo + MP_OFF_PAGE_LENGTH] = 6;
+		DEBC_printk(STp, "Formatting tape with two partitions (FDP).\n");
 	} else {
 		bp[psdo] = (size >> 8) & 0xff;
 		bp[psdo + 1] = size & 0xff;
@@ -3382,18 +3460,45 @@ 
 		if (bp[pgo + MP_OFF_PAGE_LENGTH] < 8)
 		    bp[pgo + MP_OFF_PAGE_LENGTH] = 8;
 		DEBC_printk(STp, "Formatting tape with two partitions "
-			    "(1 = %d MB).\n", size);
+			    "(1 = %d MB).\n",
+			    units > 0 ? size * 1000 : size);
 	}
 	bp[pgo + PP_OFF_PART_UNITS] = 0;
 	bp[pgo + PP_OFF_RESERVED] = 0;
-	bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | PP_MSK_PSUM_MB;
+	if (size != 1 || units != 0) {
+		bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | psum |
+			(bp[pgo + PP_OFF_FLAGS] & 0x07);
+		bp[pgo + PP_OFF_PART_UNITS] = units;
+	} else
+		bp[pgo + PP_OFF_FLAGS] = PP_BIT_FDP |
+			(bp[pgo + PP_OFF_FLAGS] & 0x07);
+	bp[pgo + MP_OFF_PAGE_LENGTH] = 6 + psd_cnt * 2;
+
+	DEBC_printk(STp, "Sent partition page length is %d bytes. needs_format: %d\n",
+		    bp[pgo + MP_OFF_PAGE_LENGTH] + 2, needs_format);
+	DEBC_printk(STp, "PP: max %u, add %u, xdp %u, psum %02x, pofmetc %u, "
+		    "rec %02x, units %02x, sizes: %u %u\n",
+		    bp[pgo + PP_OFF_MAX_ADD_PARTS],
+		    bp[pgo + PP_OFF_NBR_ADD_PARTS],
+		    (bp[pgo + PP_OFF_FLAGS] & 0xe0) >> 5,
+		    (bp[pgo + PP_OFF_FLAGS] & 0x18) >> 3,
+		    bp[pgo + PP_OFF_FLAGS] & 0x07,
+		    bp[pgo + 5],
+		    bp[pgo + PP_OFF_PART_UNITS],
+		    bp[pgo + 8] * 256 + bp[pgo + 9],
+		    bp[pgo + 10] * 256 + bp[pgo + 11]);
 
 	result = write_mode_page(STp, PART_PAGE, 1);
+
+	if (!result && needs_format)
+		result = format_medium(STp, 1);
+
 	if (result) {
 		st_printk(KERN_INFO, STp, "Partitioning of tape failed.\n");
 		result = (-EIO);
 	}
 
+out:
 	return result;
 }