[SCSI] libsas: SMP request handler shouldn't crash when rphy is NULL

sas_smp_handler crashes when smp utils are used with an aic94xx host
because certain devices (the sas_host itself, specifically) lack rphy
structures.  No rphy means no SMP target support, but we shouldn't crash
here.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index b500f0c1449c5d7da0a8b9005541556d4b757ac3..8603ae65213d114763795d8479201fc0b7021435 100644 (file)
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -1879,7 +1879,7 @@ int sas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
                    struct request *req)
 {
        struct domain_device *dev;
-       int ret, type = rphy->identify.device_type;
+       int ret, type;
        struct request *rsp = req->next_rq;
 
        if (!rsp) {
@@ -1888,12 +1888,13 @@ int sas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
                return -EINVAL;
        }
 
-       /* seems aic94xx doesn't support */
+       /* no rphy means no smp target support (ie aic94xx host) */
        if (!rphy) {
                printk("%s: can we send a smp request to a host?\n",
                       __FUNCTION__);
                return -EINVAL;
        }
+       type = rphy->identify.device_type;
 
        if (type != SAS_EDGE_EXPANDER_DEVICE &&
            type != SAS_FANOUT_EXPANDER_DEVICE) {