On 12-09-18 11:04 AM, Hannes Reinecke wrote:
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?
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.
Doug Gilbert
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