staging: lustre: fix lock imbalance

nrs_resource_put_safe() might hold a lock one one struct
while operating on the other.
There are 2 levels of structures.
Use nrs_policy_put(), which has locking baked in.

sparse gives the following warning:
drivers/staging/lustre//lustre/ptlrpc/nrs.c:498:39:
warning: context imbalance in 'nrs_resource_put_safe' -
  different lock contexts for basic block

Signed-off-by: Joshua Clayton <stillcompiling@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/lustre/lustre/ptlrpc/nrs.c b/drivers/staging/lustre/lustre/ptlrpc/nrs.c
index 7044e1ff66920eb3a1430efd38a4a2dcb66bacab..57acf8c45f9e81145e7e4dd2bad9276140b5c98b 100644 (file)
--- a/drivers/staging/lustre/lustre/ptlrpc/nrs.c
+++ b/drivers/staging/lustre/lustre/ptlrpc/nrs.c
@@ -482,7 +482,6 @@ static void nrs_resource_get_safe(struct ptlrpc_nrs *nrs,
 static void nrs_resource_put_safe(struct ptlrpc_nrs_resource **resp)
 {
        struct ptlrpc_nrs_policy *pols[NRS_RES_MAX];
-       struct ptlrpc_nrs *nrs = NULL;
        int i;
 
        for (i = 0; i < NRS_RES_MAX; i++) {
@@ -496,18 +495,9 @@ static void nrs_resource_put_safe(struct ptlrpc_nrs_resource **resp)
        }
 
        for (i = 0; i < NRS_RES_MAX; i++) {
-               if (pols[i] == NULL)
-                       continue;
-
-               if (nrs == NULL) {
-                       nrs = pols[i]->pol_nrs;
-                       spin_lock(&nrs->nrs_lock);
-               }
-               nrs_policy_put_locked(pols[i]);
+               if (pols[i])
+                       nrs_policy_put(pols[i]);
        }
-
-       if (nrs != NULL)
-               spin_unlock(&nrs->nrs_lock);
 }
 
 /**