[SCSI] libsas: fix sas_discover_devices return code handling

commit 198439e4 [SCSI] libsas: do not set res = 0 in sas_ex_discover_dev()
commit 19252de6 [SCSI] libsas: fix wide port hotplug issues

The above commits seem to have confused the return value of
sas_ex_discover_dev which is non-zero on failure and
sas_ex_join_wide_port which just indicates short circuiting discovery on
already established ports.  The result is random discovery failures
depending on configuration.

Calls to sas_ex_join_wide_port are the source of the trouble as its
return value is errantly assigned to 'res'.  Convert it to bool and stop
returning its result up the stack.

Cc: <stable@vger.kernel.org>
Tested-by: Dan Melnic <dan.melnic@amd.com>
Reported-by: Dan Melnic <dan.melnic@amd.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 63c574227ebfb0379464dfb509d2081074515584..879dbbe69799e635dab9d28c1889273e1ef3fc07 100644 (file)
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -868,7 +868,7 @@ static struct domain_device *sas_ex_discover_end_dev(
 }
 
 /* See if this phy is part of a wide port */
-static int sas_ex_join_wide_port(struct domain_device *parent, int phy_id)
+static bool sas_ex_join_wide_port(struct domain_device *parent, int phy_id)
 {
        struct ex_phy *phy = &parent->ex_dev.ex_phy[phy_id];
        int i;
@@ -884,11 +884,11 @@ static int sas_ex_join_wide_port(struct domain_device *parent, int phy_id)
                        sas_port_add_phy(ephy->port, phy->phy);
                        phy->port = ephy->port;
                        phy->phy_state = PHY_DEVICE_DISCOVERED;
-                       return 0;
+                       return true;
                }
        }
 
-       return -ENODEV;
+       return false;
 }
 
 static struct domain_device *sas_ex_discover_expander(
@@ -1030,8 +1030,7 @@ static int sas_ex_discover_dev(struct domain_device *dev, int phy_id)
                return res;
        }
 
-       res = sas_ex_join_wide_port(dev, phy_id);
-       if (!res) {
+       if (sas_ex_join_wide_port(dev, phy_id)) {
                SAS_DPRINTK("Attaching ex phy%d to wide port %016llx\n",
                            phy_id, SAS_ADDR(ex_phy->attached_sas_addr));
                return res;
@@ -1077,8 +1076,7 @@ static int sas_ex_discover_dev(struct domain_device *dev, int phy_id)
                        if (SAS_ADDR(ex->ex_phy[i].attached_sas_addr) ==
                            SAS_ADDR(child->sas_addr)) {
                                ex->ex_phy[i].phy_state= PHY_DEVICE_DISCOVERED;
-                               res = sas_ex_join_wide_port(dev, i);
-                               if (!res)
+                               if (sas_ex_join_wide_port(dev, i))
                                        SAS_DPRINTK("Attaching ex phy%d to wide port %016llx\n",
                                                    i, SAS_ADDR(ex->ex_phy[i].attached_sas_addr));
 
@@ -1943,32 +1941,20 @@ static int sas_discover_new(struct domain_device *dev, int phy_id)
 {
        struct ex_phy *ex_phy = &dev->ex_dev.ex_phy[phy_id];
        struct domain_device *child;
-       bool found = false;
-       int res, i;
+       int res;
 
        SAS_DPRINTK("ex %016llx phy%d new device attached\n",
                    SAS_ADDR(dev->sas_addr), phy_id);
        res = sas_ex_phy_discover(dev, phy_id);
        if (res)
-               goto out;
-       /* to support the wide port inserted */
-       for (i = 0; i < dev->ex_dev.num_phys; i++) {
-               struct ex_phy *ex_phy_temp = &dev->ex_dev.ex_phy[i];
-               if (i == phy_id)
-                       continue;
-               if (SAS_ADDR(ex_phy_temp->attached_sas_addr) ==
-                   SAS_ADDR(ex_phy->attached_sas_addr)) {
-                       found = true;
-                       break;
-               }
-       }
-       if (found) {
-               sas_ex_join_wide_port(dev, phy_id);
+               return res;
+
+       if (sas_ex_join_wide_port(dev, phy_id))
                return 0;
-       }
+
        res = sas_ex_discover_devices(dev, phy_id);
-       if (!res)
-               goto out;
+       if (res)
+               return res;
        list_for_each_entry(child, &dev->ex_dev.children, siblings) {
                if (SAS_ADDR(child->sas_addr) ==
                    SAS_ADDR(ex_phy->attached_sas_addr)) {
@@ -1978,7 +1964,6 @@ static int sas_discover_new(struct domain_device *dev, int phy_id)
                        break;
                }
        }
-out:
        return res;
 }