Return-Path: linux-nfs-owner@vger.kernel.org Received: from natasha.panasas.com ([209.166.131.148]:43854 "EHLO natasha.panasas.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752545AbaAVSfm (ORCPT ); Wed, 22 Jan 2014 13:35:42 -0500 Message-ID: <52E00F4E.40804@panasas.com> Date: Wed, 22 Jan 2014 20:34:54 +0200 From: Boaz Harrosh MIME-Version: 1.0 To: Trond Myklebust , NFS list CC: Stable Tree Subject: [PATCH v3] pnfs: Proper delay for NFS4ERR_RECALLCONFLICT in layout_get_done Content-Type: text/plain; charset="UTF-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: An NFS4ERR_RECALLCONFLICT is returned by server from a GET_LAYOUT only when a Server Sent a RECALL do to that GET_LAYOUT, or the RECALL and GET_LAYOUT crossed on the wire. In any way this means we want to wait at most until in-flight IO is finished and the RECALL can be satisfied. So a proper wait here is more like 1/10 of a second, not 15 seconds like we have now. In case of a server bug we delay exponentially longer on each retry. Current code totally craps out performance of very large files on most pnfs-objects layouts, because of how the map changes when the file has grown into the next raid group. [Stable: This will patch back to 3.9. If there are earlier still maintained trees, please tell me I'll send a patch] CC: Stable Tree Signed-off-by: Boaz Harrosh --- fs/nfs/nfs4proc.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index d53d678..3ba882c 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -7058,7 +7058,7 @@ static void nfs4_layoutget_done(struct rpc_task *task, void *calldata) struct nfs4_state *state = NULL; unsigned long timeo, giveup; - dprintk("--> %s\n", __func__); + dprintk("--> %s tk_status => %d\n", __func__, -task->tk_status); if (!nfs41_sequence_done(task, &lgp->res.seq_res)) goto out; @@ -7068,10 +7068,32 @@ static void nfs4_layoutget_done(struct rpc_task *task, void *calldata) goto out; case -NFS4ERR_LAYOUTTRYLATER: case -NFS4ERR_RECALLCONFLICT: + /* NFS4ERR_RECALLCONFLICT is when conflict with self (must recall + * existing layout before getting a new one). + * NFS4ERR_LAYOUTTRYLATER is a conflict with another client + * (or clients) writing to the same RAID stripe + */ timeo = rpc_get_timeout(task->tk_client); giveup = lgp->args.timestamp + timeo; - if (time_after(giveup, jiffies)) - task->tk_status = -NFS4ERR_DELAY; + if (time_after(giveup, jiffies)) { + unsigned long delay; + + /* Delay for: + * - Not less then NFS4_POLL_RETRY_MIN. + * - One last time a jiffie before we give up + * - exponential backoff (time_now minus start_attempt) + */ + delay = max_t(unsigned long, NFS4_POLL_RETRY_MIN, + min((giveup - jiffies - 1), + jiffies - lgp->args.timestamp)); + + dprintk("%s: NFS4ERR_RECALLCONFLICT waiting %lu\n", + __func__, delay); + rpc_delay(task, delay); + task->tk_status = 0; + rpc_restart_call_prepare(task); + goto out; /* Do not call nfs4_async_handle_error() */ + } break; case -NFS4ERR_EXPIRED: case -NFS4ERR_BAD_STATEID: -- 1.7.11.7