On 2016/2/5 11:13, Martin K. Petersen wrote: >>>>>> "Yiwen" == jiangyiwen <jiangyi...@huawei.com> writes: > > Yiwen, > > Yiwen> First, I don't understand why blk_peek_request() return > Yiwen> EREMOTEIO, as I know, in this situation we only prepare scsi > Yiwen> command without sending to device, and I think EREMOTEIO should > Yiwen> be returned only when IO has already sent to device, maybe I > Yiwen> don't understand definition of EREMOTEIO. So, Why don't return > Yiwen> the errno with EOPNOTSUPP? > > DM currently has special handling for EREMOTEIO failures (because that's > what we'd return when a device responds with ILLEGAL REQUEST). > > I am not opposed to returning EOPNOTSUPP but it would require more > changes and since this is a bugfix for stable I want to keep it as small > as possible. > > Yiwen> In addition, I still worried with whether there has other > Yiwen> situations which will return EIO or other error. In this way, > Yiwen> MD/DM still can happen this type of problem, so I think may be in > Yiwen> multipath we still needs a protection to avoid it. > > There are various error scenarios where we can end up bailing with a > BLKPREP_KILL. But the general rule of thumb is that these conditions all > demand a retry. The optional commands like WRITE SAME and UNMAP are > special in that they are irrecoverable. > > Yiwen> At last, I have a additional problem, I remember that you > Yiwen> previously send a series of patches about XCOPY, why don't have > Yiwen> any news latter later? I very much expect that I can see these > Yiwen> patches which are merged into kernel. > > I am working on a refresh of the series that includes token-based copy > offload support in addition to EXTENDED COPY. The patches depend on Mike > Christie's request flag patch series which has yet to be merged. > Reviewed-by: Yiwen Jiang <jiangyi...@huawei.com>
Thanks, Yiwen Jiang. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
