On Fri, Apr 20, 2012 at 06:11:02PM +0400, Stanislav Kinsbursky wrote: > v2: atomic_inc_return() was replaced by atomic_inc_not_zero(). > > These clients can't be safely dereferenced if their counter in 0. I'm pretty confused by how these notifiers work.... rpc_release_client decrements cl_count to zero temporarily, to have it immediately re-incremented by rpc_free_auth. So if we're called concurrently with rpc_release_client then it's sort of random whether someone gets this callback. Is that a problem? Also, is this an existing bug? (In which case Trond should take it now.) --b. > > Signed-off-by: Stanislav Kinsbursky <skinsbursky@xxxxxxxxxxxxx> > > --- > net/sunrpc/clnt.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c > index 6797246..d10ebc4 100644 > --- a/net/sunrpc/clnt.c > +++ b/net/sunrpc/clnt.c > @@ -218,7 +218,8 @@ static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event) > if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) || > ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry)) > continue; > - atomic_inc(&clnt->cl_count); > + if (atomic_inc_not_zero(&clnt->cl_count) == 0) > + continue; > spin_unlock(&sn->rpc_client_lock); > return clnt; > } > -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
