On Wed, 2018-10-10 at 16:55 +0200, Michal Soltys wrote:
> Hi,
>
> I have a server with old server with lsi2308 ("it" mode) and sas2x36
> expander in front. I've been testing how it handles ssd drives (among
> those if/how it copes with unmap). And it looks like
> stomped on a bug (it's 100% reproducible in 4.14.74 and 4.18.12).
>
> The hardware in question:
>
> mpt2sas_cm0: LSISAS2308: FWVersion(20.00.07.00), ChipRevision(0x05),
> BiosVersion(07.39.02.00)
> scsi host6: Fusion MPT SAS Host
> scsi 6:0:19:0: Enclosure LSI SAS2X36 0e12 PQ: 0
> ANSI: 5
>
> Tested with old Samsung 840 pro drive.
>
> Initially I was just doing a simple blkdiscard (which on the drive in
> question works just fine in plain sata controller), which greeted me
> with unexpected:
>
> 16:00 # blkdiscard /dev/sdt
> blkdiscard: /dev/sdt: BLKDISCARD ioctl failed: Remote I/O error
>
> Log in dmesg:
>
> [ 391.870979] sd 7:0:20:0: [sdt] 250069680 512-byte logical blocks:
> (128 GB/119 GiB)
> [ 391.872702] sd 7:0:20:0: [sdt] Write Protect is off
> [ 391.872705] sd 7:0:20:0: [sdt] Mode Sense: 7f 00 10 08
> [ 391.872962] sd 7:0:20:0: [sdt] Write cache: enabled, read cache:
> enabled, supports DPO and FUA
> ...
> [ 529.907273] sd 7:0:20:0: [sdt] tag#3625 FAILED Result:
> hostbyte=DID_OK driverbyte=DRIVER_SENSE
> [ 529.907277] sd 7:0:20:0: [sdt] tag#3625 Sense Key : Illegal
> Request [current]
> [ 529.907279] sd 7:0:20:0: [sdt] tag#3625 Add. Sense: Logical block
> address out of range
> [ 529.907281] sd 7:0:20:0: [sdt] tag#3625 CDB: Unmap/Read sub-
> channel 42 00 00 00 00 00 00 00 18 00
> [ 529.907283] print_req_error: critical target error, dev sdt,
> sector 247463877
>
> Then I started testing it more manually and it turned out that if I
> try to discard any range that includes the last sector, the command
> fail in this fashion. For example:
>
> 2 sectors from the end, 1 sector (works):
> blkdiscard -o $(( 250069678*512 )) -l 512 /dev/sdt
>
> 1 sectors from the end, 1 sector (fails):
> blkdiscard -o $(( 250069679*512 )) -l 512 /dev/sdt
> blkdiscard: /dev/sdt: BLKDISCARD ioctl failed: Remote I/O error
>
> [ 702.139612] sd 7:0:20:0: [sdt] tag#2511 FAILED Result:
> hostbyte=DID_OK driverbyte=DRIVER_SENSE
> [ 702.139618] sd 7:0:20:0: [sdt] tag#2511 Sense Key : Illegal
> Request [current]
> [ 702.139622] sd 7:0:20:0: [sdt] tag#2511 Add. Sense: Logical block
> address out of range
> [ 702.139627] sd 7:0:20:0: [sdt] tag#2511 CDB: Unmap/Read sub-
> channel 42 00 00 00 00 00 00 00 18 00
> [ 702.139631] print_req_error: critical target error, dev sdt,
> sector 250069679
>
> Similar results with sg_unmap:
>
> 16:36 # sg_unmap -f -l 250069678 -n 1 /dev/sdt
> 16:36 # sg_unmap -f -l 250069679 -n 1 /dev/sdt
> sg_unmap failed: LBA out of range
>
> The last sector on its own is of course normally readable/writable
> otherwise.
>
> This looks like some +/-1 division/reminder issue somewhere.
This looks like a firmware error either on the drive or the mpt3sas.
I'm afraid the only ways to fix are either:
1. Don't use discard at all and use the entire disk
2. Use discard but shorten the disk in the partition map by one sector
so the entire visible disk can be discarded
I'm afraid if you can't change the partition table, you can only use
option one (turn off discard).
James
