Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-qg0-f44.google.com ([209.85.192.44]:39542 "EHLO mail-qg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932332AbaGUPDH (ORCPT ); Mon, 21 Jul 2014 11:03:07 -0400 Received: by mail-qg0-f44.google.com with SMTP id e89so5555680qgf.3 for ; Mon, 21 Jul 2014 08:03:06 -0700 (PDT) From: Jeff Layton To: bfields@fieldses.org Cc: linux-nfs@vger.kernel.org, hch@infradead.org Subject: [PATCH 05/40] nfsd: Ensure atomicity of stateid destruction and idr tree removal Date: Mon, 21 Jul 2014 11:02:17 -0400 Message-Id: <1405954972-28904-6-git-send-email-jlayton@primarydata.com> In-Reply-To: <1405954972-28904-1-git-send-email-jlayton@primarydata.com> References: <1405954972-28904-1-git-send-email-jlayton@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Preparation for removal of the client_mutex. Ensure that they are done while holding the clp->cl_lock. Signed-off-by: Trond Myklebust --- fs/nfsd/nfs4state.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 076de12c3fa6..0243a19dbef4 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -604,13 +604,11 @@ out_dec: return NULL; } -static void remove_stid(struct nfs4_stid *s) +static void remove_stid_locked(struct nfs4_client *clp, struct nfs4_stid *s) { - struct nfs4_client *clp = s->sc_client; + lockdep_assert_held(&clp->cl_lock); - spin_lock(&clp->cl_lock); idr_remove(&clp->cl_stateids, s->sc_stateid.si_opaque.so_id); - spin_unlock(&clp->cl_lock); } static void nfs4_free_stid(struct kmem_cache *slab, struct nfs4_stid *s) @@ -620,14 +618,25 @@ static void nfs4_free_stid(struct kmem_cache *slab, struct nfs4_stid *s) kmem_cache_free(slab, s); } +static bool nfs4_put_stid(struct kmem_cache *slab, struct nfs4_stid *s) +{ + struct nfs4_client *clp = s->sc_client; + + might_lock(&clp->cl_lock); + + if (!atomic_dec_and_lock(&s->sc_count, &clp->cl_lock)) + return false; + remove_stid_locked(clp, s); + spin_unlock(&clp->cl_lock); + nfs4_free_stid(slab, s); + return true; +} + void nfs4_put_delegation(struct nfs4_delegation *dp) { - if (atomic_dec_and_test(&dp->dl_stid.sc_count)) { - remove_stid(&dp->dl_stid); - nfs4_free_stid(deleg_slab, &dp->dl_stid); + if (nfs4_put_stid(deleg_slab, &dp->dl_stid)) atomic_long_dec(&num_delegations); - } } static void nfs4_put_deleg_lease(struct nfs4_file *fp) @@ -885,10 +894,7 @@ static void close_generic_stateid(struct nfs4_ol_stateid *stp) static void put_generic_stateid(struct nfs4_ol_stateid *stp) { - if (!atomic_dec_and_test(&stp->st_stid.sc_count)) - return; - remove_stid(&stp->st_stid); - nfs4_free_stid(stateid_slab, &stp->st_stid); + nfs4_put_stid(stateid_slab, &stp->st_stid); } static void __release_lock_stateid(struct nfs4_ol_stateid *stp) -- 1.9.3