Re: [PATCH 09/17] vhost scsi: fix cmd completion race

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 30/10/20 09:51, Michael S. Tsirkin wrote:
> On Wed, Oct 21, 2020 at 07:34:55PM -0500, Mike Christie wrote:
>> We might not do the final se_cmd put from vhost_scsi_complete_cmd_work.
>> When the last put happens a little later then we could race where
>> vhost_scsi_complete_cmd_work does vhost_signal, the guest runs and sends
>> more IO, and vhost_scsi_handle_vq runs but does not find any free cmds.
>>
>> This patch has us delay completing the cmd until the last lio core ref
>> is dropped. We then know that once we signal to the guest that the cmd
>> is completed that if it queues a new command it will find a free cmd.
>>
>> Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx>
> 
> Paolo, could you review this one?

I don't know how LIO does all the callbacks, honestly (I have only ever
worked on the virtio-scsi driver, not vhost-scsi, and I have only ever
reviewed some virtio-scsi spec bits of vhost-scsi).

The vhost_scsi_complete_cmd_work parts look fine, but I have no idea why
vhost_scsi_queue_data_in and vhost_scsi_queue_status call.

Paolo




[Index of Archives]     [Linux SCSI]     [Kernel Newbies]     [Linux SCSI Target Infrastructure]     [Share Photos]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Linux IIO]     [Device Mapper]

  Powered by Linux