Kernel crash with unsupported DIF protection type

From 88f73f9e3c9e9aaa6af73885db9c6230edab6fe0 Mon Sep 17 00:00:00 2001

Hi all,

I recently got my hands on some weird drives, insisting on having been formatted with protection type 7:

# sg_readcap --16 /dev/sdb
Read Capacity results:
    Protection: prot_en=1, p_type=6, p_i_exponent=0
    Logical block provisioning: lbpme=0, lbprz=0
    Last logical block address=1758174767 (0x68cb9e2f), Number of
logical blocks=1758174768
    Logical block length=512 bytes
    Logical blocks per physical block exponent=0
    Lowest aligned logical block address=0
Hence:
    Device size: 900185481216 bytes, 858483.8 MiB, 900.19 GB

(I know. I've already complained.)
However, this drive causes a horrible crash:

sd 0:0:1:0: [sdb] formatted with unsupported protection type 7. Disabling disk!
sd 0:0:1:0: [sdb] 1758174768 512-byte logical blocks: (900 GB/838 GiB)
sd 0:0:1:0: [sdb] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
sd 0:0:1:0: [sdb] Sense Key : Medium Error [current] sd 0:0:1:0: [sdb] Add. Sense: Medium format corrupted sd 0:0:1:0: [sdb] CDB: Read(10): 28 00 00 00 00 00 00 00 08 00
end_request: I/O error, dev sdb, sector 0
Buffer I/O error on device sdb, logical block 0

[ tons and tons of I/O errors ]

[   15.551689] sd 0:0:1:0: [sdb] Enabling DIX T10-DIF-TYPE1-CRC
protection
[   15.561353] ------------[ cut here ]------------
[   15.569416] kernel BUG at

/usr/src/linux-3.0/drivers/scsi/scsi_lib.c:1069!

There are several odd things happening here:
- It says 'Disabling disk', which _should_ have set the capacity to '0':

drivers/scsi/sd.c:sd_read_protection_type()

	if (type > SD_DIF_TYPE3_PROTECTION) {
		sd_printk(KERN_ERR, sdkp, "formatted with unsupported "	\
			  "protection type %u. Disabling disk!\n", type);
		sdkp->capacity = 0;
		return;
	}

- it enables type 1 protection, which it evidently is not.

I've attached a tentative patch, which allows the system to boot. However, I'm not completely happy with that, as the capacity is _still_ updated after revalidation:

sd 0:0:1:0: [sdb] formatted with unsupported protection type 7. Disabling disk!
sd 0:0:1:0: [sdb] 0 512-byte logical blocks: (0 B/0 B)
sd 0:0:1:0: [sdb] Write Protect is off
sd 0:0:1:0: [sdb] Mode Sense: cf 00 10 08
sd 0:0:1:0: [sdb] Write cache: disabled, read cache: enabled, supports DPO and FUA
sd 0:0:1:0: [sdb] 1758174768 512-byte logical blocks: (900 GB/838 GiB) sd 0:0:1:0: [sdb] Attached SCSI disk

Thoughts?

Quoted 69 lines · Hannes Reinecke

Hi all,

I recently got my hands on some weird drives, insisting on having been formatted with protection type 7:

# sg_readcap --16 /dev/sdb
Read Capacity results:
    Protection: prot_en=1, p_type=6, p_i_exponent=0
    Logical block provisioning: lbpme=0, lbprz=0
    Last logical block address=1758174767 (0x68cb9e2f), Number of
logical blocks=1758174768
    Logical block length=512 bytes
    Logical blocks per physical block exponent=0
    Lowest aligned logical block address=0
Hence:
    Device size: 900185481216 bytes, 858483.8 MiB, 900.19 GB

(I know. I've already complained.)
However, this drive causes a horrible crash:

sd 0:0:1:0: [sdb] formatted with unsupported protection type 7. Disabling disk!
sd 0:0:1:0: [sdb] 1758174768 512-byte logical blocks: (900 GB/838 GiB)
sd 0:0:1:0: [sdb] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
sd 0:0:1:0: [sdb] Sense Key : Medium Error [current] sd 0:0:1:0: [sdb] Add. Sense: Medium format corrupted sd 0:0:1:0: [sdb] CDB: Read(10): 28 00 00 00 00 00 00 00 08 00
end_request: I/O error, dev sdb, sector 0
Buffer I/O error on device sdb, logical block 0

[ tons and tons of I/O errors ]

[   15.551689] sd 0:0:1:0: [sdb] Enabling DIX T10-DIF-TYPE1-CRC
protection
[   15.561353] ------------[ cut here ]------------
[   15.569416] kernel BUG at

/usr/src/linux-3.0/drivers/scsi/scsi_lib.c:1069!

There are several odd things happening here:
- It says 'Disabling disk', which _should_ have set the capacity to '0':

drivers/scsi/sd.c:sd_read_protection_type()

    if (type > SD_DIF_TYPE3_PROTECTION) {
        sd_printk(KERN_ERR, sdkp, "formatted with unsupported "    \
              "protection type %u. Disabling disk!\n", type);
        sdkp->capacity = 0;
        return;
    }

- it enables type 1 protection, which it evidently is not.

I've attached a tentative patch, which allows the system to boot. However, I'm not completely happy with that, as the capacity is _still_ updated after revalidation:

sd 0:0:1:0: [sdb] formatted with unsupported protection type 7. Disabling disk!
sd 0:0:1:0: [sdb] 0 512-byte logical blocks: (0 B/0 B) sd 0:0:1:0: [sdb] Write Protect is off
sd 0:0:1:0: [sdb] Mode Sense: cf 00 10 08
sd 0:0:1:0: [sdb] Write cache: disabled, read cache: enabled, supports DPO and FUA
sd 0:0:1:0: [sdb] 1758174768 512-byte logical blocks: (900 GB/838 GiB)
sd 0:0:1:0: [sdb] Attached SCSI disk

Quoted 1 line

Thoughts?

The "Medium format corrupted" additional sense qualifier occurs (with Seagate disks) when a FORMAT UNIT command is interrupted. So maybe, for good measure, that disk also sets the DIF protection type to an unsupported value (i.e. 7). So re-doing a FORMAT UNIT may clear that state.

Obviously the kernel should not crash when faced with such a disk.

Quoted 70 lines · Douglas Gilbert

Quoted 69 lines · Hannes Reinecke

Hi all,

I recently got my hands on some weird drives, insisting on having been formatted with protection type 7:

# sg_readcap --16 /dev/sdb
Read Capacity results:
     Protection: prot_en=1, p_type=6, p_i_exponent=0
     Logical block provisioning: lbpme=0, lbprz=0
     Last logical block address=1758174767 (0x68cb9e2f), Number of
logical blocks=1758174768
     Logical block length=512 bytes
     Logical blocks per physical block exponent=0
     Lowest aligned logical block address=0
Hence:
     Device size: 900185481216 bytes, 858483.8 MiB, 900.19 GB

(I know. I've already complained.)
However, this drive causes a horrible crash:

sd 0:0:1:0: [sdb] formatted with unsupported protection type 7. Disabling disk!
sd 0:0:1:0: [sdb] 1758174768 512-byte logical blocks: (900 GB/838 GiB)
sd 0:0:1:0: [sdb] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
sd 0:0:1:0: [sdb] Sense Key : Medium Error [current] sd 0:0:1:0: [sdb] Add. Sense: Medium format corrupted sd 0:0:1:0: [sdb] CDB: Read(10): 28 00 00 00 00 00 00 00 08 00
end_request: I/O error, dev sdb, sector 0
Buffer I/O error on device sdb, logical block 0

[ tons and tons of I/O errors ]

[   15.551689] sd 0:0:1:0: [sdb] Enabling DIX T10-DIF-TYPE1-CRC
protection
[   15.561353] ------------[ cut here ]------------
[   15.569416] kernel BUG at

/usr/src/linux-3.0/drivers/scsi/scsi_lib.c:1069!

There are several odd things happening here:
- It says 'Disabling disk', which _should_ have set the capacity to '0':

drivers/scsi/sd.c:sd_read_protection_type()

     if (type > SD_DIF_TYPE3_PROTECTION) {
         sd_printk(KERN_ERR, sdkp, "formatted with unsupported "    \
               "protection type %u. Disabling disk!\n", type);
         sdkp->capacity = 0;
         return;
     }

- it enables type 1 protection, which it evidently is not.

I've attached a tentative patch, which allows the system to boot. However, I'm not completely happy with that, as the capacity is _still_ updated after revalidation:

sd 0:0:1:0: [sdb] formatted with unsupported protection type 7. Disabling disk!
sd 0:0:1:0: [sdb] 0 512-byte logical blocks: (0 B/0 B) sd 0:0:1:0: [sdb] Write Protect is off
sd 0:0:1:0: [sdb] Mode Sense: cf 00 10 08
sd 0:0:1:0: [sdb] Write cache: disabled, read cache: enabled, supports DPO and FUA
sd 0:0:1:0: [sdb] 1758174768 512-byte logical blocks: (900 GB/838 GiB)
sd 0:0:1:0: [sdb] Attached SCSI disk

Quoted 8 lines

Quoted 1 line

Thoughts?

The "Medium format corrupted" additional sense qualifier occurs (with Seagate disks) when a FORMAT UNIT command is interrupted. So maybe, for good measure, that disk also sets the DIF protection type to an unsupported value (i.e. 7). So re-doing a FORMAT UNIT may clear that state.

Yeah, that's what I'm doing now.

Incidentally:

sg_format manpage says:

Format with type 1 protection:

sg_format --format --fmtpinfo=3 --pfu /dev/sdm

but the '--pfu' option requires an argument.
According to sbc3r23 the command should read:

sg_format --format --fmtpinfo=3 --pfu=1 /dev/sdm

Correct?

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"Hannes" == Hannes Reinecke <[email protected]> writes:

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"Hannes" == Hannes Reinecke <[email protected]> writes:

Hannes> I recently got my hands on some weird drives, insisting on Hannes> having been formatted with protection type 7:

Lovely :|

Hannes> I've attached a tentative patch, which allows the system to Hannes> boot. However, I'm not completely happy with that, as the Hannes> capacity is _still_ updated after revalidation:

How about this?

sd: Ensure we correctly disable devices with unknown protection type

We set the capacity to zero when we discovered a device formatted with an unknown DIF protection type. However, the read_capacity code would override the capacity and cause the device to be enabled regardless.

Make sd_read_protection_type() return an error if the protection type is unknown. Also prevent duplicate printk lines when the device is being revalidated.

Reported-by Hannes Reinecke <[email protected]>

Signed-off-by Martin K. Petersen <[email protected]>

drivers/scsi/sd.c +25 -17

index 1cf2d5d..1c54564 100644
@@ -1820,34 +1820,42 @@ sd_spinup_disk(struct scsi_disk *sdkp)
 /*
  * Determine whether disk supports Data Integrity Field.
  */
-static void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
+static int sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
 {
 	struct scsi_device *sdp = sdkp->device;
 	u8 type;
+	int ret = 0;
 
 	if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
-		return;
+		return ret;
 
 	type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
 
-	if (type == sdkp->protection_type || !sdkp->first_scan)
-		return;
+	if (type > SD_DIF_TYPE3_PROTECTION)
+		ret = -ENODEV;
+	else if (scsi_host_dif_capable(sdp->host, type))
+		ret = 1;
+
+	if (sdkp->first_scan || type != sdkp->protection_type)
+		switch (ret) {
+		case -ENODEV:
+			sd_printk(KERN_ERR, sdkp, "formatted with unsupported" \
+				  " protection type %u. Disabling disk!\n",
+				  type);
+			break;
+		case 1:
+			sd_printk(KERN_NOTICE, sdkp,
+				  "Enabling DIF Type %u protection\n", type);
+			break;
+		case 0:
+			sd_printk(KERN_NOTICE, sdkp,
+				  "Disabling DIF Type %u protection\n", type);
+			break;
+		}
 
 	sdkp->protection_type = type;
 
-	if (type > SD_DIF_TYPE3_PROTECTION) {
-		sd_printk(KERN_ERR, sdkp, "formatted with unsupported "	\
-			  "protection type %u. Disabling disk!\n", type);
-		sdkp->capacity = 0;
-		return;
-	}
-
-	if (scsi_host_dif_capable(sdp->host, type))
-		sd_printk(KERN_NOTICE, sdkp,
-			  "Enabling DIF Type %u protection\n", type);
-	else
-		sd_printk(KERN_NOTICE, sdkp,
-			  "Disabling DIF Type %u protection\n", type);
+	return ret;
 }
 
 static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,

@@ -1943,7 +1951,10 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
 	sector_size = get_unaligned_be32(&buffer[8]);

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"Hannes" == Hannes Reinecke <[email protected]> writes:

Hannes> I recently got my hands on some weird drives, insisting on Hannes> having been formatted with protection type 7:

Lovely :|

Hannes> I've attached a tentative patch, which allows the system to Hannes> boot. However, I'm not completely happy with that, as the Hannes> capacity is _still_ updated after revalidation:

How about this?

sd: Ensure we correctly disable devices with unknown protection type

We set the capacity to zero when we discovered a device formatted with an unknown DIF protection type. However, the read_capacity code would override the capacity and cause the device to be enabled regardless.

Make sd_read_protection_type() return an error if the protection type is unknown. Also prevent duplicate printk lines when the device is being revalidated.

Reported-by Hannes Reinecke <[email protected]>

Signed-off-by Martin K. Petersen <[email protected]>

drivers/scsi/sd.c +25 -17

index 1cf2d5d..1c54564 100644
@@ -1820,34 +1820,42 @@ sd_spinup_disk(struct scsi_disk *sdkp)
 /*
  * Determine whether disk supports Data Integrity Field.
  */
-static void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
+static int sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
 {
 	struct scsi_device *sdp = sdkp->device;
 	u8 type;
+	int ret = 0;
 
 	if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
-		return;
+		return ret;
 
 	type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
 
-	if (type == sdkp->protection_type || !sdkp->first_scan)
-		return;
+	if (type > SD_DIF_TYPE3_PROTECTION)
+		ret = -ENODEV;
+	else if (scsi_host_dif_capable(sdp->host, type))
+		ret = 1;
+
+	if (sdkp->first_scan || type != sdkp->protection_type)
+		switch (ret) {
+		case -ENODEV:
+			sd_printk(KERN_ERR, sdkp, "formatted with unsupported" \
+				  " protection type %u. Disabling disk!\n",
+				  type);
+			break;
+		case 1:
+			sd_printk(KERN_NOTICE, sdkp,
+				  "Enabling DIF Type %u protection\n", type);
+			break;
+		case 0:
+			sd_printk(KERN_NOTICE, sdkp,
+				  "Disabling DIF Type %u protection\n", type);
+			break;
+		}
 
 	sdkp->protection_type = type;
 
-	if (type > SD_DIF_TYPE3_PROTECTION) {
-		sd_printk(KERN_ERR, sdkp, "formatted with unsupported "	\
-			  "protection type %u. Disabling disk!\n", type);
-		sdkp->capacity = 0;
-		return;
-	}
-
-	if (scsi_host_dif_capable(sdp->host, type))
-		sd_printk(KERN_NOTICE, sdkp,
-			  "Enabling DIF Type %u protection\n", type);
-	else
-		sd_printk(KERN_NOTICE, sdkp,
-			  "Disabling DIF Type %u protection\n", type);
+	return ret;
 }
 
 static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,

@@ -1943,7 +1951,10 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
 	sector_size = get_unaligned_be32(&buffer[8]);

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"Hannes" == Hannes Reinecke <[email protected]> writes:

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"Martin" == Martin K Petersen <[email protected]> writes: