01.05.2012 01:45, J. Bruce Fields написал:
On Fri, Apr 27, 2012 at 06:08:13PM +0400, Stanislav Kinsbursky wrote:
On 27.04.2012 17:55, J. Bruce Fields wrote:
On Wed, Apr 25, 2012 at 05:37:49PM +0400, Stanislav Kinsbursky wrote:
Registering service with svc_bind() can fail. In this case service will be
destroyed and during destruction it will try to unregister itself from rpcbind.
In this case unregister have to be skipped.
Isn't this a preexisting bug, in which case perhaps Trond should at it
to his list of bugs to submit now?
Not it's not.
Previously, in case of bind operations failure, rpcb_put_local()
wasn't called, but service data was destroyed instead:
- if (svc_uses_rpcbind(serv)) {
- if (svc_rpcb_setup(serv, current->nsproxy->net_ns)< 0) {
- kfree(serv->sv_pools);
- kfree(serv);
- return NULL;
- }
- if (!serv->sv_shutdown)
- serv->sv_shutdown = svc_rpcb_cleanup;
- }
Now (with svc_bind() introduction) service can be created, but
svc_bind() could fail. And thus svc_destroy() have to be called.
Which will call rpcb_put_local().
And the problem here that svc_bind() can fail before incrementing of
rpcb usage counter.
OK, but then you're fixing a bug that you just introduced with the
previous patch.
So this should be combined with the previous patch.
--b.
You, probably, right. I'll do this.
Thanks.
Signed-off-by: Stanislav Kinsbursky<skinsbursky@xxxxxxxxxxxxx>
---
net/sunrpc/rpcb_clnt.c | 12 +++++++-----
1 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 78ac39f..4c38b33 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -180,14 +180,16 @@ void rpcb_put_local(struct net *net)
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
struct rpc_clnt *clnt = sn->rpcb_local_clnt;
struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
- int shutdown;
+ int shutdown = 0;
spin_lock(&sn->rpcb_clnt_lock);
- if (--sn->rpcb_users == 0) {
- sn->rpcb_local_clnt = NULL;
- sn->rpcb_local_clnt4 = NULL;
+ if (sn->rpcb_users) {
+ if (--sn->rpcb_users == 0) {
+ sn->rpcb_local_clnt = NULL;
+ sn->rpcb_local_clnt4 = NULL;
+ }
+ shutdown = !sn->rpcb_users;
}
- shutdown = !sn->rpcb_users;
spin_unlock(&sn->rpcb_clnt_lock);
if (shutdown) {
--
Best regards,
Stanislav Kinsbursky
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