From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_GIT autolearn=unavailable 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 D5808C28EBD for ; Sun, 9 Jun 2019 17:00:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF523208C0 for ; Sun, 9 Jun 2019 17:00:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560099633; bh=DT/Z1nB2H+ExUpjs59kVCrqSG9O7n5z4+2mg3fVoeKE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rdE7Zd1zrgdnrB1gJvyU1wsslsgmTINEhkDi5wQZPFAtQObBUtfvTLNuJWMw/jQls bQSXkDTVrX6Yj9KBIzZGDfJQfrTyoRAQV1Yo2S/VlHs5Zo/KOTzq8gqfU5+mCgko/1 fbiKvpNghDMKst12p0xkVb0fxneAHRppS1QsXq6c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387466AbfFIRAc (ORCPT ); Sun, 9 Jun 2019 13:00:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:36972 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387855AbfFIRA3 (ORCPT ); Sun, 9 Jun 2019 13:00:29 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B7F0E206DF; Sun, 9 Jun 2019 17:00:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560099628; bh=DT/Z1nB2H+ExUpjs59kVCrqSG9O7n5z4+2mg3fVoeKE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MusAi7kucqzGSyI60OwHYzsLCdXYfwh9q1kzveceaSmVEKnGn+sCCOClfP4DUNDTe 7ZU7Xd0j3OGqYudhwmcdkydKkChkiS5cYnwRCVVUjcR+wYhfuWtS3vLGsmSteJFYWX opUKX815nZviEAZvkwv40OM56hSdtv8Iyt0mzonI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Coly Li , Jens Axboe , Sasha Levin Subject: [PATCH 4.4 109/241] bcache: add failure check to run_cache_set() for journal replay Date: Sun, 9 Jun 2019 18:40:51 +0200 Message-Id: <20190609164150.942468950@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190609164147.729157653@linuxfoundation.org> References: <20190609164147.729157653@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit ce3e4cfb59cb382f8e5ce359238aa580d4ae7778 ] Currently run_cache_set() has no return value, if there is failure in bch_journal_replay(), the caller of run_cache_set() has no idea about such failure and just continue to execute following code after run_cache_set(). The internal failure is triggered inside bch_journal_replay() and being handled in async way. This behavior is inefficient, while failure handling inside bch_journal_replay(), cache register code is still running to start the cache set. Registering and unregistering code running as same time may introduce some rare race condition, and make the code to be more hard to be understood. This patch adds return value to run_cache_set(), and returns -EIO if bch_journal_rreplay() fails. Then caller of run_cache_set() may detect such failure and stop registering code flow immedidately inside register_cache_set(). If journal replay fails, run_cache_set() can report error immediately to register_cache_set(). This patch makes the failure handling for bch_journal_replay() be in synchronized way, easier to understand and debug, and avoid poetential race condition for register-and-unregister in same time. Signed-off-by: Coly Li Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/md/bcache/super.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 2140c5b48b511..02757b90e4029 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1558,7 +1558,7 @@ struct cache_set *bch_cache_set_alloc(struct cache_sb *sb) return NULL; } -static void run_cache_set(struct cache_set *c) +static int run_cache_set(struct cache_set *c) { const char *err = "cannot allocate memory"; struct cached_dev *dc, *t; @@ -1650,7 +1650,9 @@ static void run_cache_set(struct cache_set *c) if (j->version < BCACHE_JSET_VERSION_UUID) __uuid_write(c); - bch_journal_replay(c, &journal); + err = "bcache: replay journal failed"; + if (bch_journal_replay(c, &journal)) + goto err; } else { pr_notice("invalidating existing data"); @@ -1718,11 +1720,13 @@ static void run_cache_set(struct cache_set *c) flash_devs_run(c); set_bit(CACHE_SET_RUNNING, &c->flags); - return; + return 0; err: closure_sync(&cl); /* XXX: test this, it's broken */ bch_cache_set_error(c, "%s", err); + + return -EIO; } static bool can_attach_cache(struct cache *ca, struct cache_set *c) @@ -1786,8 +1790,11 @@ static const char *register_cache_set(struct cache *ca) ca->set->cache[ca->sb.nr_this_dev] = ca; c->cache_by_alloc[c->caches_loaded++] = ca; - if (c->caches_loaded == c->sb.nr_in_set) - run_cache_set(c); + if (c->caches_loaded == c->sb.nr_in_set) { + err = "failed to run cache set"; + if (run_cache_set(c) < 0) + goto err; + } return NULL; err: -- 2.20.1