From patchwork Tue Aug 17 03:44:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiubo Li X-Patchwork-Id: 499055 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A601C4338F for ; Tue, 17 Aug 2021 03:44:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C8B060EB5 for ; Tue, 17 Aug 2021 03:44:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234051AbhHQDp2 (ORCPT ); Mon, 16 Aug 2021 23:45:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:38979 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233686AbhHQDp1 (ORCPT ); Mon, 16 Aug 2021 23:45:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1629171894; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=PrNXWuhGxaawALFm6Gb6avEvY0MtenciPndrvfzxwvk=; b=Se/bLp7f8G85Yipqlg/Yfx4TCROc1eNJThrp/0b2nuH4zAh6OOvwHHX/OBtJUkCokDYdAX ZaDGa/2EbRmOUrotxQN+LnOoVxsMebSmjD4QSrp2voem+3B6hu94LGC04rmEUeC8oSBCRG gjQlLtjYBvTe9mbxpYA7IT5ELX2ZN9Y= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-14--Q2wWLfmPhylkxmBXT33gw-1; Mon, 16 Aug 2021 23:44:51 -0400 X-MC-Unique: -Q2wWLfmPhylkxmBXT33gw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1EEFF802929; Tue, 17 Aug 2021 03:44:50 +0000 (UTC) Received: from lxbceph1.gsslab.pek2.redhat.com (unknown [10.72.47.117]) by smtp.corp.redhat.com (Postfix) with ESMTP id 22C615D6A8; Tue, 17 Aug 2021 03:44:47 +0000 (UTC) From: xiubli@redhat.com To: jlayton@kernel.org Cc: idryomov@gmail.com, pdonnell@redhat.com, ceph-devel@vger.kernel.org, Xiubo Li Subject: [PATCH v2] ceph: try to reconnect to the export targets Date: Tue, 17 Aug 2021 11:44:45 +0800 Message-Id: <20210817034445.405663-1-xiubli@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org From: Xiubo Li In case the export MDS is crashed just after the EImportStart journal is flushed, so when a standby MDS takes over it and when replaying the EImportStart journal the MDS will wait the client to reconnect, but the client may never register/open the sessions yet. We will try to reconnect that MDSes if they're in the export targets and in RECONNECT state. Signed-off-by: Xiubo Li --- - check the export target rank when decoding the mdsmap instead of BUG_ON - fix issue that the sessions have been opened during the mutex's unlock/lock gap fs/ceph/mds_client.c | 63 +++++++++++++++++++++++++++++++++++++++++++- fs/ceph/mdsmap.c | 10 ++++--- 2 files changed, 69 insertions(+), 4 deletions(-) diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index e49dbeb6c06f..1e013fb09d73 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -4197,13 +4197,22 @@ static void check_new_map(struct ceph_mds_client *mdsc, struct ceph_mdsmap *newmap, struct ceph_mdsmap *oldmap) { - int i; + int i, err; + int *export_targets; int oldstate, newstate; struct ceph_mds_session *s; + struct ceph_mds_info *m_info; dout("check_new_map new %u old %u\n", newmap->m_epoch, oldmap->m_epoch); + m_info = newmap->m_info; + export_targets = kcalloc(newmap->possible_max_rank, sizeof(int), GFP_NOFS); + if (export_targets && m_info) { + for (i = 0; i < m_info->num_export_targets; i++) + export_targets[m_info->export_targets[i]] = 1; + } + for (i = 0; i < oldmap->possible_max_rank && i < mdsc->max_sessions; i++) { if (!mdsc->sessions[i]) continue; @@ -4257,6 +4266,8 @@ static void check_new_map(struct ceph_mds_client *mdsc, if (s->s_state == CEPH_MDS_SESSION_RESTARTING && newstate >= CEPH_MDS_STATE_RECONNECT) { mutex_unlock(&mdsc->mutex); + if (export_targets) + export_targets[i] = 0; send_mds_reconnect(mdsc, s); mutex_lock(&mdsc->mutex); } @@ -4279,6 +4290,54 @@ static void check_new_map(struct ceph_mds_client *mdsc, } } + /* + * Only open and reconnect sessions that don't exist yet. + */ + for (i = 0; i < newmap->possible_max_rank; i++) { + if (unlikely(!export_targets)) + break; + + /* + * In case the import MDS is crashed just after + * the EImportStart journal is flushed, so when + * a standby MDS takes over it and is replaying + * the EImportStart journal the new MDS daemon + * will wait the client to reconnect it, but the + * client may never register/open the session yet. + * + * Will try to reconnect that MDS daemon if the + * rank number is in the export_targets array and + * is the up:reconnect state. + */ + newstate = ceph_mdsmap_get_state(newmap, i); + if (!export_targets[i] || newstate != CEPH_MDS_STATE_RECONNECT) + continue; + + /* + * The session maybe registered and opened by some + * requests which were choosing random MDSes during + * the mdsc->mutex's unlock/lock gap below in rare + * case. But the related MDS daemon will just queue + * that requests and be still waiting for the client's + * reconnection request in up:reconnect state. + */ + s = __ceph_lookup_mds_session(mdsc, i); + if (likely(!s)) { + s = __open_export_target_session(mdsc, i); + if (IS_ERR(s)) { + err = PTR_ERR(s); + pr_err("failed to open export target session, err %d\n", + err); + continue; + } + } + dout("send reconnect to export target mds.%d\n", i); + mutex_unlock(&mdsc->mutex); + send_mds_reconnect(mdsc, s); + mutex_lock(&mdsc->mutex); + ceph_put_mds_session(s); + } + for (i = 0; i < newmap->possible_max_rank && i < mdsc->max_sessions; i++) { s = mdsc->sessions[i]; if (!s) @@ -4293,6 +4352,8 @@ static void check_new_map(struct ceph_mds_client *mdsc, __open_export_target_sessions(mdsc, s); } } + + kfree(export_targets); } diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c index 3c444b9cb17b..d995cb02d30c 100644 --- a/fs/ceph/mdsmap.c +++ b/fs/ceph/mdsmap.c @@ -122,6 +122,7 @@ struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end, bool msgr2) int err; u8 mdsmap_v; u16 mdsmap_ev; + u32 target; m = kzalloc(sizeof(*m), GFP_NOFS); if (!m) @@ -260,9 +261,12 @@ struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end, bool msgr2) sizeof(u32), GFP_NOFS); if (!info->export_targets) goto nomem; - for (j = 0; j < num_export_targets; j++) - info->export_targets[j] = - ceph_decode_32(&pexport_targets); + for (j = 0; j < num_export_targets; j++) { + target = ceph_decode_32(&pexport_targets); + if (target >= m->possible_max_rank) + goto corrupt; + info->export_targets[j] = target; + } } else { info->export_targets = NULL; }