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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16241C433FE for ; Thu, 7 Apr 2022 17:22:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346210AbiDGRYs (ORCPT ); Thu, 7 Apr 2022 13:24:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46746 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346123AbiDGRYH (ORCPT ); Thu, 7 Apr 2022 13:24:07 -0400 Received: from ale.deltatee.com (ale.deltatee.com [204.191.154.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D84C21AF37; Thu, 7 Apr 2022 10:22:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:MIME-Version:References:In-Reply-To: Message-Id:Date:Cc:To:From:content-disposition; bh=rfpeReUyOakDeWgnZ8ReEXJWBQv5CMxmL/J4NdHYak8=; b=KJx+vBhsS5uHJB+cFfcY8I4WEr z+w4X0fM9q1jvM/Y7cAT34U+WeameXar9PjOaz+JtAyvBezDyiFDM5fxl3Cie6jkDI+PjQN5UtqMW UiLNR3JuCB6hMXKaE29X2AvMp48vhsZ6OQpyaOxBQdTmBV0ovKcawR8282QLCbkxR+eenuj/PGTTf mSi7D73PIzVKk+Vbb6UmJ2PhY6fZGdl0y9mgbip/5Rde/Cw5qlGFfk2yLWFJc120VtSiswhxkr2Rh AlUTDTuzZmrPbVpP/HfIb/c5SwZS4diYS+GQiU3FJmFhM7BoeUue63YFsNRJGKPVGLGDDrfDSdcpZ 1nTPdd8g==; Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1ncVG1-002CHl-9u; Thu, 07 Apr 2022 10:45:18 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.94.2) (envelope-from ) id 1ncVFz-0002Db-UX; Thu, 07 Apr 2022 10:45:16 -0600 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, Song Liu Cc: Shaohua Li , Guoqing Jiang , Stephen Bates , Martin Oliveira , David Sloan , Logan Gunthorpe Date: Thu, 7 Apr 2022 10:45:04 -0600 Message-Id: <20220407164511.8472-2-logang@deltatee.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220407164511.8472-1-logang@deltatee.com> References: <20220407164511.8472-1-logang@deltatee.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, song@kernel.org, shli@kernel.org, guoqing.jiang@linux.dev, sbates@raithlin.com, Martin.Oliveira@eideticom.com, David.Sloan@eideticom.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v1 1/8] md/raid5: Refactor raid5_make_request loop X-SA-Exim-Version: 4.2.1 (built Sat, 13 Feb 2021 17:57:42 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Break immediately if raid5_get_active_stripe() returns NULL and deindent the rest of the loop. Annotate this check with an unlikely(). This makes the code easier to read and reduces the indentation level. No functional changes intended. Signed-off-by: Logan Gunthorpe --- drivers/md/raid5.c | 111 +++++++++++++++++++++++---------------------- 1 file changed, 56 insertions(+), 55 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 351d341a1ffa..b794253efd15 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -5868,69 +5868,70 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) sh = raid5_get_active_stripe(conf, new_sector, previous, (bi->bi_opf & REQ_RAHEAD), 0); - if (sh) { - if (unlikely(previous)) { - /* expansion might have moved on while waiting for a - * stripe, so we must do the range check again. - * Expansion could still move past after this - * test, but as we are holding a reference to - * 'sh', we know that if that happens, - * STRIPE_EXPANDING will get set and the expansion - * won't proceed until we finish with the stripe. - */ - int must_retry = 0; - spin_lock_irq(&conf->device_lock); - if (mddev->reshape_backwards - ? logical_sector >= conf->reshape_progress - : logical_sector < conf->reshape_progress) - /* mismatch, need to try again */ - must_retry = 1; - spin_unlock_irq(&conf->device_lock); - if (must_retry) { - raid5_release_stripe(sh); - schedule(); - do_prepare = true; - goto retry; - } - } - if (read_seqcount_retry(&conf->gen_lock, seq)) { - /* Might have got the wrong stripe_head - * by accident - */ - raid5_release_stripe(sh); - goto retry; - } + if (unlikely(!sh)) { + /* cannot get stripe, just give-up */ + bi->bi_status = BLK_STS_IOERR; + break; + } - if (test_bit(STRIPE_EXPANDING, &sh->state) || - !add_stripe_bio(sh, bi, dd_idx, rw, previous)) { - /* Stripe is busy expanding or - * add failed due to overlap. Flush everything - * and wait a while - */ - md_wakeup_thread(mddev->thread); + if (unlikely(previous)) { + /* + * Expansion might have moved on while waiting for a + * stripe, so we must do the range check again. + * Expansion could still move past after this + * test, but as we are holding a reference to + * 'sh', we know that if that happens, + * STRIPE_EXPANDING will get set and the expansion + * won't proceed until we finish with the stripe. + */ + int must_retry = 0; + spin_lock_irq(&conf->device_lock); + if (mddev->reshape_backwards + ? logical_sector >= conf->reshape_progress + : logical_sector < conf->reshape_progress) + /* mismatch, need to try again */ + must_retry = 1; + spin_unlock_irq(&conf->device_lock); + if (must_retry) { raid5_release_stripe(sh); schedule(); do_prepare = true; goto retry; } - if (do_flush) { - set_bit(STRIPE_R5C_PREFLUSH, &sh->state); - /* we only need flush for one stripe */ - do_flush = false; - } + } + if (read_seqcount_retry(&conf->gen_lock, seq)) { + /* Might have got the wrong stripe_head by accident */ + raid5_release_stripe(sh); + goto retry; + } - set_bit(STRIPE_HANDLE, &sh->state); - clear_bit(STRIPE_DELAYED, &sh->state); - if ((!sh->batch_head || sh == sh->batch_head) && - (bi->bi_opf & REQ_SYNC) && - !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) - atomic_inc(&conf->preread_active_stripes); - release_stripe_plug(mddev, sh); - } else { - /* cannot get stripe for read-ahead, just give-up */ - bi->bi_status = BLK_STS_IOERR; - break; + if (test_bit(STRIPE_EXPANDING, &sh->state) || + !add_stripe_bio(sh, bi, dd_idx, rw, previous)) { + /* + * Stripe is busy expanding or add failed due to + * overlap. Flush everything and wait a while. + */ + md_wakeup_thread(mddev->thread); + raid5_release_stripe(sh); + schedule(); + do_prepare = true; + goto retry; } + + if (do_flush) { + set_bit(STRIPE_R5C_PREFLUSH, &sh->state); + /* we only need flush for one stripe */ + do_flush = false; + } + + set_bit(STRIPE_HANDLE, &sh->state); + clear_bit(STRIPE_DELAYED, &sh->state); + if ((!sh->batch_head || sh == sh->batch_head) && + (bi->bi_opf & REQ_SYNC) && + !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) + atomic_inc(&conf->preread_active_stripes); + + release_stripe_plug(mddev, sh); } finish_wait(&conf->wait_for_overlap, &w); -- 2.30.2