[PATCH] sunrpc: remove unnecessary svc_xprt_put

Neil Brown
2010-02-26T22:33:47Z

[I found this while looking for the current refcount problem
that triggers a warning in svc_recv. This isn't that bug
but is a different refcount bug - NB]

The 'struct svc_deferred_req's on the xpt_deferred queue do not
own a reference to the owning xprt. This is seen in svc_revisit
which is where things are added to this queue. dr->xprt is set to
NULL and the reference to the xprt it put.

So when this list is cleaned up in svc_delete_xprt, we mustn't
put the reference.

Also, replace the 'for' with a 'while' which is arguably
simpler and more likely to compile efficiently.

Cc: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 7d1f9e9..4f30336 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -889,11 +889,8 @@ void svc_delete_xprt(struct svc_xprt *xprt)
if (test_bit(XPT_TEMP, &xprt->xpt_flags))
serv->sv_tmpcnt--;

- for (dr = svc_deferred_dequeue(xprt); dr;
- dr = svc_deferred_dequeue(xprt)) {
- svc_xprt_put(xprt);
+ while ((dr = svc_deferred_dequeue(xprt)) != NULL)
kfree(dr);
- }

svc_xprt_put(xprt);
spin_unlock_bh(&serv->sv_lock);