From patchwork Tue Sep 6 15:04:48 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 9317187 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 27AFD600CA for ; Tue, 6 Sep 2016 15:04:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 25B39281C3 for ; Tue, 6 Sep 2016 15:04:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 18ACD28DE3; Tue, 6 Sep 2016 15:04:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 52C0F28DDF for ; Tue, 6 Sep 2016 15:04:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755076AbcIFPEy (ORCPT ); Tue, 6 Sep 2016 11:04:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53630 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753966AbcIFPEw (ORCPT ); Tue, 6 Sep 2016 11:04:52 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7CF1EC05680F; Tue, 6 Sep 2016 15:04:52 +0000 (UTC) Received: from tlielax.poochiereds.net (ovpn-116-58.rdu2.redhat.com [10.10.116.58]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u86F4ome017756; Tue, 6 Sep 2016 11:04:51 -0400 From: Jeff Layton To: bfields@fieldses.org Cc: linux-nfs@vger.kernel.org Subject: [PATCH v2 2/4] nfsd: have nfsd4_lock use blocking locks for v4.1+ locks Date: Tue, 6 Sep 2016 11:04:48 -0400 Message-Id: <1473174290-29612-3-git-send-email-jlayton@redhat.com> In-Reply-To: <1473174290-29612-1-git-send-email-jlayton@redhat.com> References: <1473174290-29612-1-git-send-email-jlayton@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Tue, 06 Sep 2016 15:04:52 +0000 (UTC) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Create a new per-lockowner+per-inode structure that contains a file_lock. Have nfsd4_lock add this structure to the lockowner's list prior to setting the lock. Then call the vfs and request a blocking lock (by setting FL_SLEEP). If we get anything besides FILE_LOCK_DEFERRED back, then we dequeue the block structure and free it. When the next lock request comes in, we'll look for an existing block for the same filehandle and dequeue and reuse it if there is one. When the lock comes free (a'la an lm_notify call), we dequeue it from the lockowner's list and kick off a CB_NOTIFY_LOCK callback to inform the client that it should retry the lock request. Signed-off-by: Jeff Layton --- fs/nfsd/nfs4state.c | 164 ++++++++++++++++++++++++++++++++++++++++++++++------ fs/nfsd/state.h | 12 +++- 2 files changed, 156 insertions(+), 20 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index a204d7e109d4..ca0db4974e5b 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -99,6 +99,7 @@ static struct kmem_cache *odstate_slab; static void free_session(struct nfsd4_session *); static const struct nfsd4_callback_ops nfsd4_cb_recall_ops; +static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops; static bool is_session_dead(struct nfsd4_session *ses) { @@ -210,6 +211,84 @@ static void nfsd4_put_session(struct nfsd4_session *ses) spin_unlock(&nn->client_lock); } +static struct nfsd4_blocked_lock * +find_blocked_lock(struct nfs4_lockowner *lo, struct knfsd_fh *fh, + struct nfsd_net *nn) +{ + struct nfsd4_blocked_lock *cur, *found = NULL; + + spin_lock(&nn->client_lock); + list_for_each_entry(cur, &lo->lo_blocked, nbl_list) { + if (fh_match(fh, &cur->nbl_fh)) { + list_del_init(&cur->nbl_list); + found = cur; + break; + } + } + spin_unlock(&nn->client_lock); + if (found) + posix_unblock_lock(&found->nbl_lock); + return found; +} + +static struct nfsd4_blocked_lock * +find_or_allocate_block(struct nfs4_lockowner *lo, struct knfsd_fh *fh, + struct nfsd_net *nn) +{ + struct nfsd4_blocked_lock *nbl; + + nbl = find_blocked_lock(lo, fh, nn); + if (!nbl) { + nbl= kmalloc(sizeof(*nbl), GFP_KERNEL); + if (nbl) { + fh_copy_shallow(&nbl->nbl_fh, fh); + locks_init_lock(&nbl->nbl_lock); + nfsd4_init_cb(&nbl->nbl_cb, lo->lo_owner.so_client, + &nfsd4_cb_notify_lock_ops, + NFSPROC4_CLNT_CB_NOTIFY_LOCK); + } + } + return nbl; +} + +static void +free_blocked_lock(struct nfsd4_blocked_lock *nbl) +{ + locks_release_private(&nbl->nbl_lock); + kfree(nbl); +} + +static int +nfsd4_cb_notify_lock_done(struct nfsd4_callback *cb, struct rpc_task *task) +{ + /* + * Since this is just an optimization, we don't try very hard if it + * turns out not to succeed. We'll requeue it on NFS4ERR_DELAY, and + * just quit trying on anything else. + */ + switch (task->tk_status) { + case -NFS4ERR_DELAY: + rpc_delay(task, 1 * HZ); + return 0; + default: + return 1; + } +} + +static void +nfsd4_cb_notify_lock_release(struct nfsd4_callback *cb) +{ + struct nfsd4_blocked_lock *nbl = container_of(cb, + struct nfsd4_blocked_lock, nbl_cb); + + free_blocked_lock(nbl); +} + +static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops = { + .done = nfsd4_cb_notify_lock_done, + .release = nfsd4_cb_notify_lock_release, +}; + static inline struct nfs4_stateowner * nfs4_get_stateowner(struct nfs4_stateowner *sop) { @@ -5309,7 +5388,29 @@ nfsd4_fl_put_owner(fl_owner_t owner) nfs4_put_stateowner(&lo->lo_owner); } +static void +nfsd4_lm_notify(struct file_lock *fl) +{ + struct nfs4_lockowner *lo = (struct nfs4_lockowner *)fl->fl_owner; + struct net *net = lo->lo_owner.so_client->net; + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct nfsd4_blocked_lock *nbl = container_of(fl, + struct nfsd4_blocked_lock, nbl_lock); + bool queue = false; + + spin_lock(&nn->client_lock); + if (!list_empty(&nbl->nbl_list)) { + list_del_init(&nbl->nbl_list); + queue = true; + } + spin_unlock(&nn->client_lock); + + if (queue) + nfsd4_run_cb(&nbl->nbl_cb); +} + static const struct lock_manager_operations nfsd_posix_mng_ops = { + .lm_notify = nfsd4_lm_notify, .lm_get_owner = nfsd4_fl_get_owner, .lm_put_owner = nfsd4_fl_put_owner, }; @@ -5407,6 +5508,7 @@ alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp, lo = alloc_stateowner(lockowner_slab, &lock->lk_new_owner, clp); if (!lo) return NULL; + INIT_LIST_HEAD(&lo->lo_blocked); INIT_LIST_HEAD(&lo->lo_owner.so_stateids); lo->lo_owner.so_is_open_owner = 0; lo->lo_owner.so_seqid = lock->lk_new_lock_seqid; @@ -5588,12 +5690,15 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfs4_ol_stateid *open_stp = NULL; struct nfs4_file *fp; struct file *filp = NULL; + struct nfsd4_blocked_lock *nbl = NULL; struct file_lock *file_lock = NULL; struct file_lock *conflock = NULL; __be32 status = 0; int lkflg; int err; bool new = false; + unsigned char fl_type; + unsigned int fl_flags = FL_POSIX; struct net *net = SVC_NET(rqstp); struct nfsd_net *nn = net_generic(net, nfsd_net_id); @@ -5658,46 +5763,55 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, if (!locks_in_grace(net) && lock->lk_reclaim) goto out; - file_lock = locks_alloc_lock(); - if (!file_lock) { - dprintk("NFSD: %s: unable to allocate lock!\n", __func__); - status = nfserr_jukebox; - goto out; - } - fp = lock_stp->st_stid.sc_file; switch (lock->lk_type) { - case NFS4_READ_LT: case NFS4_READW_LT: + if (nfsd4_has_session(cstate)) + fl_flags |= FL_SLEEP; + /* Fallthrough */ + case NFS4_READ_LT: spin_lock(&fp->fi_lock); filp = find_readable_file_locked(fp); if (filp) get_lock_access(lock_stp, NFS4_SHARE_ACCESS_READ); spin_unlock(&fp->fi_lock); - file_lock->fl_type = F_RDLCK; + fl_type = F_RDLCK; break; - case NFS4_WRITE_LT: case NFS4_WRITEW_LT: + if (nfsd4_has_session(cstate)) + fl_flags |= FL_SLEEP; + /* Fallthrough */ + case NFS4_WRITE_LT: spin_lock(&fp->fi_lock); filp = find_writeable_file_locked(fp); if (filp) get_lock_access(lock_stp, NFS4_SHARE_ACCESS_WRITE); spin_unlock(&fp->fi_lock); - file_lock->fl_type = F_WRLCK; + fl_type = F_WRLCK; break; default: status = nfserr_inval; goto out; } + if (!filp) { status = nfserr_openmode; goto out; } + nbl = find_or_allocate_block(lock_sop, &fp->fi_fhandle, nn); + if (!nbl) { + dprintk("NFSD: %s: unable to allocate block!\n", __func__); + status = nfserr_jukebox; + goto out; + } + + file_lock = &nbl->nbl_lock; + file_lock->fl_type = fl_type; file_lock->fl_owner = (fl_owner_t)lockowner(nfs4_get_stateowner(&lock_sop->lo_owner)); file_lock->fl_pid = current->tgid; file_lock->fl_file = filp; - file_lock->fl_flags = FL_POSIX; + file_lock->fl_flags = fl_flags; file_lock->fl_lmops = &nfsd_posix_mng_ops; file_lock->fl_start = lock->lk_offset; file_lock->fl_end = last_byte_offset(lock->lk_offset, lock->lk_length); @@ -5710,18 +5824,27 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, goto out; } + if (fl_flags & FL_SLEEP) { + spin_lock(&nn->client_lock); + list_add_tail(&nbl->nbl_list, &lock_sop->lo_blocked); + spin_unlock(&nn->client_lock); + } + err = vfs_lock_file(filp, F_SETLK, file_lock, conflock); - switch (-err) { + switch (err) { case 0: /* success! */ nfs4_inc_and_copy_stateid(&lock->lk_resp_stateid, &lock_stp->st_stid); status = 0; break; - case (EAGAIN): /* conflock holds conflicting lock */ + case FILE_LOCK_DEFERRED: + nbl = NULL; + /* Fallthrough */ + case -EAGAIN: /* conflock holds conflicting lock */ status = nfserr_denied; dprintk("NFSD: nfsd4_lock: conflicting lock found!\n"); nfs4_set_lock_denied(conflock, &lock->lk_denied); break; - case (EDEADLK): + case -EDEADLK: status = nfserr_deadlock; break; default: @@ -5730,6 +5853,15 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, break; } out: + if (nbl) { + /* dequeue it if we queued it before */ + if (fl_flags & FL_SLEEP) { + spin_lock(&nn->client_lock); + list_del_init(&nbl->nbl_list); + spin_unlock(&nn->client_lock); + } + free_blocked_lock(nbl); + } if (filp) fput(filp); if (lock_stp) { @@ -5753,8 +5885,6 @@ out: if (open_stp) nfs4_put_stid(&open_stp->st_stid); nfsd4_bump_seqid(cstate, status); - if (file_lock) - locks_free_lock(file_lock); if (conflock) locks_free_lock(conflock); return status; diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 127cc84ca5a3..f6ffeac391f4 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -441,11 +441,11 @@ struct nfs4_openowner { /* * Represents a generic "lockowner". Similar to an openowner. References to it * are held by the lock stateids that are created on its behalf. This object is - * a superset of the nfs4_stateowner struct (or would be if it needed any extra - * fields). + * a superset of the nfs4_stateowner struct. */ struct nfs4_lockowner { - struct nfs4_stateowner lo_owner; /* must be first element */ + struct nfs4_stateowner lo_owner; /* must be first element */ + struct list_head lo_blocked; /* blocked file_locks */ }; static inline struct nfs4_openowner * openowner(struct nfs4_stateowner *so) @@ -581,7 +581,13 @@ static inline bool nfsd4_stateid_generation_after(stateid_t *a, stateid_t *b) return (s32)(a->si_generation - b->si_generation) > 0; } +/* + * When a client tries to get a lock on a file, we set one of these objects + * on the blocking lock. When the lock becomes free, we can then issue a + * CB_NOTIFY_LOCK to the server. + */ struct nfsd4_blocked_lock { + struct list_head nbl_list; struct file_lock nbl_lock; struct knfsd_fh nbl_fh; struct nfsd4_callback nbl_cb;