Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ie0-f173.google.com ([209.85.223.173]:44704 "EHLO mail-ie0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755537AbaA1X2I convert rfc822-to-8bit (ORCPT ); Tue, 28 Jan 2014 18:28:08 -0500 Received: by mail-ie0-f173.google.com with SMTP id e14so1336696iej.18 for ; Tue, 28 Jan 2014 15:28:07 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 7.1 \(1827\)) Subject: Re: [PATCH 1/1] NFSv4.1 free slot before resending I/O to MDS From: Trond Myklebust In-Reply-To: <1390950074-7245-2-git-send-email-andros@netapp.com> Date: Tue, 28 Jan 2014 18:28:06 -0500 Cc: linuxnfs Message-Id: <3E87C7B9-82D2-493F-B4CE-BC163A3EB4CA@primarydata.com> References: <1390950074-7245-1-git-send-email-andros@netapp.com> <1390950074-7245-2-git-send-email-andros@netapp.com> To: Adamson William Andros Sender: linux-nfs-owner@vger.kernel.org List-ID: Hi Andy, On Jan 28, 2014, at 18:01, wrote: > From: Andy Adamson > > Free an allocated slot from nfs41_wake_and_assign_slot prior to rpc_exit. > Prevents a state_manager hang when draining a data server session. > > Signed-off-by: Andy Adamson > --- > fs/nfs/nfs4filelayout.c | 6 ++++++ > fs/nfs/nfs4session.c | 1 + > 2 files changed, 7 insertions(+) > > diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c > index 03fd8be..9611999 100644 > --- a/fs/nfs/nfs4filelayout.c > +++ b/fs/nfs/nfs4filelayout.c > @@ -314,6 +314,9 @@ static void filelayout_read_prepare(struct rpc_task *task, void *data) > if (filelayout_reset_to_mds(rdata->header->lseg)) { > dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid); > filelayout_reset_read(rdata); > + if (rdata->res.seq_res.sr_slot != NULL) > + nfs4_free_slot(&rdata->ds_clp->cl_session->fc_slot_table, > + rdata->res.seq_res.sr_slot); > rpc_exit(task, 0); > return; > } > @@ -425,6 +428,9 @@ static void filelayout_write_prepare(struct rpc_task *task, void *data) > if (filelayout_reset_to_mds(wdata->header->lseg)) { > dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid); > filelayout_reset_write(wdata); > + if (wdata->res.seq_res.sr_slot != NULL) > + nfs4_free_slot(&wdata->ds_clp->cl_session->fc_slot_table, > + wdata->res.seq_res.sr_slot); > rpc_exit(task, 0); > return; > } > diff --git a/fs/nfs/nfs4session.c b/fs/nfs/nfs4session.c > index cf883c7..5226846 100644 > --- a/fs/nfs/nfs4session.c > +++ b/fs/nfs/nfs4session.c > @@ -98,6 +98,7 @@ void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot) > dprintk("%s: slotid %u highest_used_slotid %u\n", __func__, > slotid, tbl->highest_used_slotid); > } > +EXPORT_SYMBOL_GPL(nfs4_free_slot); > > static struct nfs4_slot *nfs4_new_slot(struct nfs4_slot_table *tbl, > u32 slotid, u32 seq_init, gfp_t gfp_mask) OK, this fix makes a lot more sense to me. However, since rpc_exit() will trigger a call to the rpc_call_ops->rpc_call_done(), then perhaps a better alternative would be to have filelayout_read_call_done() and filelayout_write_call_done() call nfs41_sequence_done() if the test for NFS_IOHDR_REDO succeeds? Otherwise, it looks as if we still have the potential for a leak. -- Trond Myklebust Linux NFS client maintainer