On Wed, Dec 28, 2016 at 6:21 PM, Guilherme G. Piccoli
<gpiccoli@xxxxxxxxxxxxxxxxxx> wrote:
> From: Ram Pai <linuxram@xxxxxxxxxx>
>
> The firmware or device, possibly under a heavy I/O load, can return
> on a partial unaligned boundary. Scsi-ml expects these requests to be
> completed on an alignment boundary. Scsi-ml blindly requeues the I/O
> without checking the alignment boundary of the I/O request for the
> remaining bytes. This leads to errors, since devices cannot perform
> non-aligned read/write operations.
>
> This patch fixes the issue in the driver. It aligns unaligned
> completions of FS requests, by truncating them to the nearest
> alignment boundary.
>
> Reported-by: Mauricio Faria De Oliveira <mauricfo@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
> ---
> drivers/scsi/mpt3sas/mpt3sas_scsih.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
> index b5c966e..55332a3 100644
> --- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
> +++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
> @@ -4644,6 +4644,8 @@ _scsih_io_done(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 msix_index, u32 reply)
> struct MPT3SAS_DEVICE *sas_device_priv_data;
> u32 response_code = 0;
> unsigned long flags;
> + unsigned int sector_sz;
> + struct request *req;
>
> mpi_reply = mpt3sas_base_get_reply_virt_addr(ioc, reply);
> scmd = _scsih_scsi_lookup_get_clear(ioc, smid);
> @@ -4703,6 +4705,20 @@ _scsih_io_done(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 msix_index, u32 reply)
> }
>
> xfer_cnt = le32_to_cpu(mpi_reply->TransferCount);
> +
> + /* In case of bogus fw or device, we could end up having
> + * unaligned partial completion. We can force alignment here,
> + * then scsi-ml does not need to handle this misbehavior.
> + */
> + sector_sz = scmd->device->sector_size;
> + req = scmd->request;
> + if (unlikely(sector_sz && req && (req->cmd_type == REQ_TYPE_FS) &&
> + (xfer_cnt % sector_sz))) {
> + sdev_printk(KERN_INFO, scmd->device,
> + "unaligned partial completion avoided\n");
[Sreekanth] Patch looks good. But can we print xfer_cnt & sector_sz
values along with above print.
Also if it is generic drive issue, then can we move this work around
to SCSI Mid Layer?
> + xfer_cnt = (xfer_cnt / sector_sz) * sector_sz;
> + }
> +
> scsi_set_resid(scmd, scsi_bufflen(scmd) - xfer_cnt);
> if (ioc_status & MPI2_IOCSTATUS_FLAG_LOG_INFO_AVAILABLE)
> log_info = le32_to_cpu(mpi_reply->IOCLogInfo);
> --
> 2.1.0
>
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