mptfusion: enable no_write_same for vmware scsi disks

commit 4089b71cc820a426d601283c92fcd4ffeb5139c2 upstream.

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.

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>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/message/fusion/mptspi.c b/drivers/message/fusion/mptspi.c
index 5653e505f91ff0af540db4e7bb973ef3f03059a4..424f51d1e2ce0d9624d8fb49ae0ed470d9d87bdc 100644 (file)
--- a/drivers/message/fusion/mptspi.c
+++ b/drivers/message/fusion/mptspi.c
@@ -1422,6 +1422,11 @@ 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