Return-Path: Received: from daytona.panasas.com ([67.152.220.89]:7695 "EHLO daytona.int.panasas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752122Ab0I2LKm (ORCPT ); Wed, 29 Sep 2010 07:10:42 -0400 From: Benny Halevy To: linux-nfs@vger.kernel.org Subject: [PATCH 7/9] pnfs: allow nfs4_proc_layoutget to sleep on invalid lsegs Date: Wed, 29 Sep 2010 13:10:38 +0200 Message-Id: <1285758638-26971-1-git-send-email-bhalevy@panasas.com> In-Reply-To: <4CA31DC3.8070300@panasas.com> References: <4CA31DC3.8070300@panasas.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Content-Type: text/plain MIME-Version: 1.0 Introduce lo_rpcwaitq and sleep on it while there's an lseg marked invalid, i.e. it is being returned (in the future, it could also be layoutget in progress). Signed-off-by: Benny Halevy --- fs/nfs/inode.c | 1 + fs/nfs/nfs4proc.c | 25 ++++++++++++++++++++++--- fs/nfs/pnfs.c | 26 ++++++++++++++++---------- include/linux/nfs_fs.h | 1 + 4 files changed, 40 insertions(+), 13 deletions(-) diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 8cdea1a..e3d44a9 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -1459,6 +1459,7 @@ static inline void nfs4_init_once(struct nfs_inode *nfsi) nfsi->delegation_state = 0; init_rwsem(&nfsi->rwsem); init_waitqueue_head(&nfsi->lo_waitq); + rpc_init_wait_queue(&nfsi->lo_rpcwaitq, "pNFS Layout"); nfsi->layout = NULL; #endif } diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index cd87704..ebf5127 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5426,13 +5426,32 @@ nfs4_layoutget_prepare(struct rpc_task *task, void *calldata) { struct nfs4_layoutget *lgp = calldata; struct inode *ino = lgp->args.inode; + struct nfs_inode *nfsi = NFS_I(ino); struct nfs_server *server = NFS_SERVER(ino); + struct pnfs_layout_segment *lseg; dprintk("--> %s\n", __func__); - if (nfs4_setup_sequence(server, NULL, &lgp->args.seq_args, - &lgp->res.seq_res, 0, task)) + spin_lock(&ino->i_lock); + lseg = pnfs_has_layout(nfsi->layout, &lgp->args.range); + if (likely(!lseg)) { + spin_unlock(&ino->i_lock); + dprintk("%s: no lseg found, proceeding\n", __func__); + if (!nfs4_setup_sequence(server, NULL, &lgp->args.seq_args, + &lgp->res.seq_res, 0, task)) + rpc_call_start(task); return; - rpc_call_start(task); + } + if (!lseg->valid) { + put_lseg_locked(lseg); + spin_unlock(&ino->i_lock); + dprintk("%s: invalid lseg found, waiting\n", __func__); + rpc_sleep_on(&nfsi->lo_rpcwaitq, task, NULL); + return; + } + *lgp->lsegpp = lseg; + spin_unlock(&ino->i_lock); + dprintk("%s: valid lseg found, no rpc required\n", __func__); + rpc_exit(task, NFS4_OK); } static void nfs4_layoutget_done(struct rpc_task *task, void *calldata) diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 8339444..31a703d 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -315,8 +315,10 @@ put_lseg_locked(struct pnfs_layout_segment *lseg) do_wake_up = !lseg->valid; nfsi = NFS_I(lseg->layout->inode); kref_put(&lseg->kref, destroy_lseg); - if (do_wake_up) + if (do_wake_up) { wake_up(&nfsi->lo_waitq); + rpc_wake_up(&nfsi->lo_rpcwaitq); + } } EXPORT_SYMBOL_GPL(put_lseg_locked); @@ -975,17 +977,21 @@ pnfs_update_layout(struct inode *ino, /* Check to see if the layout for the given range already exists */ lseg = pnfs_has_layout(lo, &arg); - if (lseg && !lseg->valid) { - put_lseg_locked(lseg); + if (lseg) { + if (lseg->valid) { + dprintk("%s: Using cached lseg %p for %llu@%llu " + "iomode %d)\n", + __func__, + lseg, + arg.length, + arg.offset, + arg.iomode); + + goto out_unlock; + } /* someone is cleaning the layout */ + put_lseg_locked(lseg); lseg = NULL; - goto out_unlock; - } - - if (lseg) { - dprintk("%s: Using cached lseg %p for iomode %d)\n", - __func__, lseg, iomode); - goto out_unlock; } /* if LAYOUTGET already failed once we don't try again */ diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 3184e63..1af18fd 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -191,6 +191,7 @@ struct nfs_inode { /* pNFS layout information */ wait_queue_head_t lo_waitq; + struct rpc_wait_queue lo_rpcwaitq; struct pnfs_layout_hdr *layout; #endif /* CONFIG_NFS_V4*/ #ifdef CONFIG_NFS_FSCACHE -- 1.7.2.3