Re: [PATCH v2] block: ratelimite pr_err on IO path

["Martin K. Petersen" <martin.petersen@oracle.com>]

Jinpu,

[CC:ed the mpt3sas maintainers]

The ratelimit patch is just an attempt to treat the symptom, not the
cause.

> Thanks for asking, we updated mpt3sas driver which enables DIX support
> (prot_mask=0x7f), all disks are SATA SSDs, no DIF support.
> After reboot, kernel reports the IO errors from all the drives behind
> HBA, seems for almost every read IO, which turns the system unusable:
> [   13.079375] sda: ref tag error at location 0 (rcvd 143196159)
> [   13.079989] sda: ref tag error at location 937702912 (rcvd 143196159)
> [   13.080233] sda: ref tag error at location 937703072 (rcvd 143196159)
> [   13.080407] sda: ref tag error at location 0 (rcvd 143196159)
> [   13.080594] sda: ref tag error at location 8 (rcvd 143196159)

That sounds like a bug in the mpt3sas driver or firmware. I guess the
HBA could conceivably be operating a SATA device as DIX Type 0 and strip
the PI on the drive side. But that doesn't seem to be a particularly
useful mode of operation.

Jinpu: Which firmware are you running? Also, please send us the output
of:

        sg_readcap -l /dev/sda
        sg_inq -x /dev/sda
        sg_vpd /dev/sda

Broadcom: How is DIX supposed to work for SATA drives behind an mpt3sas
controller?

-- 
Martin K. Petersen	Oracle Linux Engineering