Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-qa0-f42.google.com ([209.85.216.42]:57812 "EHLO mail-qa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761707AbaGRPOD (ORCPT ); Fri, 18 Jul 2014 11:14:03 -0400 Received: by mail-qa0-f42.google.com with SMTP id j15so3194783qaq.1 for ; Fri, 18 Jul 2014 08:14:02 -0700 (PDT) From: Jeff Layton To: bfields@fieldses.org Cc: hch@infradead.org, linux-nfs@vger.kernel.org, Neil Brown Subject: [PATCH v4 10/10] nfsd: give block_delegation and delegation_blocked its own spinlock Date: Fri, 18 Jul 2014 11:13:36 -0400 Message-Id: <1405696416-32585-11-git-send-email-jlayton@primarydata.com> In-Reply-To: <1405696416-32585-1-git-send-email-jlayton@primarydata.com> References: <1405696416-32585-1-git-send-email-jlayton@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: The state lock can be fairly heavily contended, and there's no reason that nfs4_file lookups and delegation_blocked should be mutually exclusive. Let's give the new block_delegation code its own spinlock. It does mean that we'll need to take a different lock in the delegation break code, but that's not generally as critical to performance. Cc: Neil Brown Signed-off-by: Jeff Layton --- fs/nfsd/nfs4state.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index a2c6c85adfc7..952def00363b 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -506,10 +506,11 @@ static struct nfs4_ol_stateid * nfs4_alloc_stateid(struct nfs4_client *clp) * Each filter is 256 bits. We hash the filehandle to 32bit and use the * low 3 bytes as hash-table indices. * - * 'state_lock', which is always held when block_delegations() is called, - * is used to manage concurrent access. Testing does not need the lock - * except when swapping the two filters. + * 'blocked_delegations_lock', which is always held when block_delegations() + * is called, is used to manage concurrent access. Testing does not need the + * lock except when swapping the two filters. */ +static DEFINE_SPINLOCK(blocked_delegations_lock); static struct bloom_pair { int entries, old_entries; time_t swap_time; @@ -525,7 +526,7 @@ static int delegation_blocked(struct knfsd_fh *fh) if (bd->entries == 0) return 0; if (seconds_since_boot() - bd->swap_time > 30) { - spin_lock(&state_lock); + spin_lock(&blocked_delegations_lock); if (seconds_since_boot() - bd->swap_time > 30) { bd->entries -= bd->old_entries; bd->old_entries = bd->entries; @@ -534,7 +535,7 @@ static int delegation_blocked(struct knfsd_fh *fh) bd->new = 1-bd->new; bd->swap_time = seconds_since_boot(); } - spin_unlock(&state_lock); + spin_unlock(&blocked_delegations_lock); } hash = arch_fast_hash(&fh->fh_base, fh->fh_size, 0); if (test_bit(hash&255, bd->set[0]) && @@ -555,16 +556,16 @@ static void block_delegations(struct knfsd_fh *fh) u32 hash; struct bloom_pair *bd = &blocked_delegations; - lockdep_assert_held(&state_lock); - hash = arch_fast_hash(&fh->fh_base, fh->fh_size, 0); __set_bit(hash&255, bd->set[bd->new]); __set_bit((hash>>8)&255, bd->set[bd->new]); __set_bit((hash>>16)&255, bd->set[bd->new]); + spin_lock(&blocked_delegations_lock); if (bd->entries == 0) bd->swap_time = seconds_since_boot(); bd->entries += 1; + spin_unlock(&blocked_delegations_lock); } static struct nfs4_delegation * @@ -3097,16 +3098,16 @@ void nfsd4_prepare_cb_recall(struct nfs4_delegation *dp) struct nfs4_client *clp = dp->dl_stid.sc_client; struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); - /* - * We can't do this in nfsd_break_deleg_cb because it is - * already holding inode->i_lock - */ - spin_lock(&state_lock); block_delegations(&dp->dl_fh); + /* + * We can't do this in nfsd_break_deleg_cb because it is + * already holding inode->i_lock. + * * If the dl_time != 0, then we know that it has already been * queued for a lease break. Don't queue it again. */ + spin_lock(&state_lock); if (dp->dl_time == 0) { dp->dl_time = get_seconds(); list_add_tail(&dp->dl_recall_lru, &nn->del_recall_lru); -- 1.9.3