net/9p: Add a Warning to catch NULL fids passed to p9_client_clunk().

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

diff --git a/net/9p/client.c b/net/9p/client.c
index c155cc4..e50ec80 100644 (file)
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1168,6 +1168,12 @@ int p9_client_clunk(struct p9_fid *fid)
        struct p9_client *clnt;
        struct p9_req_t *req;
 
+       if (!fid) {
+               P9_EPRINTK(KERN_WARNING, "Trying to clunk with NULL fid\n");
+               dump_stack();
+               return 0;
+       }
+
        P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
        err = 0;
        clnt = fid->clnt;