[PATCH v5 01/34] cxlflash: Fix to avoid invalid port_sel value

[Tomas Henzl]

On 1.10.2015 17:54, Matthew R. Ochs wrote:
> From: Manoj Kumar <kumarmn at us.ibm.com>
>
> If two concurrent MANAGE_LUN ioctls are issued with the same
> WWID parameter, it would result in an incorrect value of port_sel.
>
> This is because port_sel is modified without any locks being
> held. If the first caller stalls after the return from
> find_and_create_lun(), the value of port_sel will be set
> incorrectly to indicate a single port, though in this case
> it should have been set to both ports.
>
> To fix, use the global mutex to serialize the lookup of the
> WWID and the subsequent modification of port_sel.
>
> Signed-off-by: Matthew R. Ochs <mrochs at linux.vnet.ibm.com>
> Signed-off-by: Manoj N. Kumar <manoj at linux.vnet.ibm.com>
> Reviewed-by: Brian King <brking at linux.vnet.ibm.com>

Reviewed-by: Tomas Henzl <thenzl at redhat.com>

Tomas