Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ie0-f173.google.com ([209.85.223.173]:64252 "EHLO mail-ie0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753696AbaDRSpV (ORCPT ); Fri, 18 Apr 2014 14:45:21 -0400 Received: by mail-ie0-f173.google.com with SMTP id rl12so1910114iec.18 for ; Fri, 18 Apr 2014 11:45:21 -0700 (PDT) From: Trond Myklebust To: Bruce Fields Cc: linux-nfs@vger.kernel.org Subject: [PATCH 10/70] NFSd: Avoid taking state_lock while holding inode lock in nfsd_break_one_deleg Date: Fri, 18 Apr 2014 14:44:04 -0400 Message-Id: <1397846704-14567-11-git-send-email-trond.myklebust@primarydata.com> In-Reply-To: <1397846704-14567-10-git-send-email-trond.myklebust@primarydata.com> References: <1397846704-14567-1-git-send-email-trond.myklebust@primarydata.com> <1397846704-14567-2-git-send-email-trond.myklebust@primarydata.com> <1397846704-14567-3-git-send-email-trond.myklebust@primarydata.com> <1397846704-14567-4-git-send-email-trond.myklebust@primarydata.com> <1397846704-14567-5-git-send-email-trond.myklebust@primarydata.com> <1397846704-14567-6-git-send-email-trond.myklebust@primarydata.com> <1397846704-14567-7-git-send-email-trond.myklebust@primarydata.com> <1397846704-14567-8-git-send-email-trond.myklebust@primarydata.com> <1397846704-14567-9-git-send-email-trond.myklebust@primarydata.com> <1397846704-14567-10-git-send-email-trond.myklebust@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: state_lock is a heavily contended global lock. We don't want to grab that while simultaneously holding the inode->i_lock Instead do the list manipulations from the work queue context prior to starting the rpc call. Signed-off-by: Trond Myklebust --- fs/nfsd/nfs4callback.c | 18 ++++++++++++++++-- fs/nfsd/nfs4state.c | 25 +++++++++++++++---------- fs/nfsd/state.h | 1 + 3 files changed, 32 insertions(+), 12 deletions(-) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index 39c8ef875f91..8626cd6af4d1 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -1009,9 +1009,8 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb) run_nfsd4_cb(cb); } -static void nfsd4_do_callback_rpc(struct work_struct *w) +static void nfsd4_run_callback_rpc(struct nfsd4_callback *cb) { - struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work); struct nfs4_client *clp = cb->cb_clp; struct rpc_clnt *clnt; @@ -1029,11 +1028,25 @@ static void nfsd4_do_callback_rpc(struct work_struct *w) cb->cb_ops, cb); } +static void nfsd4_do_callback_rpc(struct work_struct *w) +{ + struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work); + nfsd4_run_callback_rpc(cb); +} + void nfsd4_init_callback(struct nfsd4_callback *cb) { INIT_WORK(&cb->cb_work, nfsd4_do_callback_rpc); } +static void nfsd4_do_cb_recall(struct work_struct *w) +{ + struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work); + + nfsd4_prepare_cb_recall(cb->cb_op); + nfsd4_run_callback_rpc(cb); +} + void nfsd4_cb_recall(struct nfs4_delegation *dp) { struct nfsd4_callback *cb = &dp->dl_recall; @@ -1050,6 +1063,7 @@ void nfsd4_cb_recall(struct nfs4_delegation *dp) INIT_LIST_HEAD(&cb->cb_per_client); cb->cb_done = true; + INIT_WORK(&cb->cb_work, nfsd4_do_cb_recall); run_nfsd4_cb(&dp->dl_recall); } diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 6d691aa2bb27..85fcbc9ebd40 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -2743,24 +2743,31 @@ out: return ret; } -static void nfsd_break_one_deleg(struct nfs4_delegation *dp) +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); - lockdep_assert_held(&state_lock); + /* + * We can't do this in nfsd_break_deleg_cb because it is + * already holding inode->i_lock + */ + spin_lock(&state_lock); + if (list_empty(&dp->dl_recall_lru)) { + dp->dl_time = get_seconds(); + list_add_tail(&dp->dl_recall_lru, &nn->del_recall_lru); + } + spin_unlock(&state_lock); +} + +static void nfsd_break_one_deleg(struct nfs4_delegation *dp) +{ /* We're assuming the state code never drops its reference * without first removing the lease. Since we're in this lease * callback (and since the lease code is serialized by the kernel * lock) we know the server hasn't removed the lease yet, we know * it's safe to take a reference: */ atomic_inc(&dp->dl_count); - - list_add_tail(&dp->dl_recall_lru, &nn->del_recall_lru); - - /* Only place dl_time is set; protected by i_lock: */ - dp->dl_time = get_seconds(); - nfsd4_cb_recall(dp); } @@ -2785,11 +2792,9 @@ static void nfsd_break_deleg_cb(struct file_lock *fl) */ fl->fl_break_time = 0; - spin_lock(&state_lock); fp->fi_had_conflict = true; list_for_each_entry(dp, &fp->fi_delegations, dl_perfile) nfsd_break_one_deleg(dp); - spin_unlock(&state_lock); } static diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 1aa22f39fc65..02c5a203c738 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -473,6 +473,7 @@ extern void nfsd4_cb_recall(struct nfs4_delegation *dp); extern int nfsd4_create_callback_queue(void); extern void nfsd4_destroy_callback_queue(void); extern void nfsd4_shutdown_callback(struct nfs4_client *); +extern void nfsd4_prepare_cb_recall(struct nfs4_delegation *dp); extern void nfs4_put_delegation(struct nfs4_delegation *dp); extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(const char *name, struct nfsd_net *nn); -- 1.9.0