Re: [PATCH v3] mptfusion: enable no_write_same for vmware scsi disks

[Chris J Arges <chris.j.arges@canonical.com>]

On 09/23/2014 09:22 AM, Chris J Arges wrote:
> When using a virtual SCSI disk in a VMWare VM if blkdev_issue_zeroout is used
> data can be improperly zeroed out using the mptfusion driver. This patch
> disables write_same for this driver and the vmware subsystem_vendor which
> ensures that manual zeroing out is used instead.
> 

Please hold off on applying this, I'm pursuing a different approach to
solving this bug that may be more optimal than adding this quirk.
Thanks,
--chris j arges


> BugLink: http://bugs.launchpad.net/bugs/1371591
> Reported-by: Bruce Lucas <bruce.lucas@mongodb.com>
> Tested-by: Chris J Arges <chris.j.arges@canonical.com>
> Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
> ---
>  drivers/message/fusion/mptspi.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/message/fusion/mptspi.c b/drivers/message/fusion/mptspi.c
> index 787933d..613231c 100644
> --- a/drivers/message/fusion/mptspi.c
> +++ b/drivers/message/fusion/mptspi.c
> @@ -1419,6 +1419,11 @@ mptspi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  		goto out_mptspi_probe;
>          }
>  
> +	/* VMWare emulation doesn't properly implement WRITE_SAME
> +	 */
> +	if (pdev->subsystem_vendor == 0x15AD)
> +		sh->no_write_same = 1;
> +
>  	spin_lock_irqsave(&ioc->FreeQlock, flags);
>  
>  	/* Attach the SCSI Host to the IOC structure
>