IB/usnic: Handle 0 counts in resource allocation

Signed-off-by: Dave Goodell <dgoodell@cisco.com>
Reviewed-by: Reese Faucette <rfaucett@cisco.com>
Reviewed-by: Xuyang Wang <xuywang@cisco.com>
Signed-off-by: Nelson Escobar <neescoba@cisco.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/hw/usnic/usnic_vnic.c b/drivers/infiniband/hw/usnic/usnic_vnic.c
index 66de93f..8875107 100644 (file)
--- a/drivers/infiniband/hw/usnic/usnic_vnic.c
+++ b/drivers/infiniband/hw/usnic/usnic_vnic.c
@@ -237,7 +237,7 @@ usnic_vnic_get_resources(struct usnic_vnic *vnic, enum usnic_vnic_res_type type,
        struct usnic_vnic_res *res;
        int i;
 
-       if (usnic_vnic_res_free_cnt(vnic, type) < cnt || cnt < 1 || !owner)
+       if (usnic_vnic_res_free_cnt(vnic, type) < cnt || cnt < 0 || !owner)
                return ERR_PTR(-EINVAL);
 
        ret = kzalloc(sizeof(*ret), GFP_ATOMIC);
@@ -247,26 +247,28 @@ usnic_vnic_get_resources(struct usnic_vnic *vnic, enum usnic_vnic_res_type type,
                return ERR_PTR(-ENOMEM);
        }
 
-       ret->res = kzalloc(sizeof(*(ret->res))*cnt, GFP_ATOMIC);
-       if (!ret->res) {
-               usnic_err("Failed to allocate resources for %s. Out of memory\n",
-                               usnic_vnic_pci_name(vnic));
-               kfree(ret);
-               return ERR_PTR(-ENOMEM);
-       }
+       if (cnt > 0) {
+               ret->res = kcalloc(cnt, sizeof(*(ret->res)), GFP_ATOMIC);
+               if (!ret->res) {
+                       usnic_err("Failed to allocate resources for %s. Out of memory\n",
+                                       usnic_vnic_pci_name(vnic));
+                       kfree(ret);
+                       return ERR_PTR(-ENOMEM);
+               }
 
-       spin_lock(&vnic->res_lock);
-       src = &vnic->chunks[type];
-       for (i = 0; i < src->cnt && ret->cnt < cnt; i++) {
-               res = src->res[i];
-               if (!res->owner) {
-                       src->free_cnt--;
-                       res->owner = owner;
-                       ret->res[ret->cnt++] = res;
+               spin_lock(&vnic->res_lock);
+               src = &vnic->chunks[type];
+               for (i = 0; i < src->cnt && ret->cnt < cnt; i++) {
+                       res = src->res[i];
+                       if (!res->owner) {
+                               src->free_cnt--;
+                               res->owner = owner;
+                               ret->res[ret->cnt++] = res;
+                       }
                }
-       }
 
-       spin_unlock(&vnic->res_lock);
+               spin_unlock(&vnic->res_lock);
+       }
        ret->type = type;
        ret->vnic = vnic;
        WARN_ON(ret->cnt != cnt);
@@ -281,14 +283,16 @@ void usnic_vnic_put_resources(struct usnic_vnic_res_chunk *chunk)
        int i;
        struct usnic_vnic *vnic = chunk->vnic;
 
-       spin_lock(&vnic->res_lock);
-       while ((i = --chunk->cnt) >= 0) {
-               res = chunk->res[i];
-               chunk->res[i] = NULL;
-               res->owner = NULL;
-               vnic->chunks[res->type].free_cnt++;
+       if (chunk->cnt > 0) {
+               spin_lock(&vnic->res_lock);
+               while ((i = --chunk->cnt) >= 0) {
+                       res = chunk->res[i];
+                       chunk->res[i] = NULL;
+                       res->owner = NULL;
+                       vnic->chunks[res->type].free_cnt++;
+               }
+               spin_unlock(&vnic->res_lock);
        }
-       spin_unlock(&vnic->res_lock);
 
        kfree(chunk->res);
        kfree(chunk);