From patchwork Mon Dec 9 09:38:26 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11278759 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 96680112B for ; Mon, 9 Dec 2019 09:38:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 736A320663 for ; Mon, 9 Dec 2019 09:38:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="lXKWFRmZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727540AbfLIJio (ORCPT ); Mon, 9 Dec 2019 04:38:44 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:57880 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727535AbfLIJin (ORCPT ); Mon, 9 Dec 2019 04:38:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=k5RsMEOMJaFsRNBGR/bElLkw+x3AOqjk9Txrf4p1gxY=; b=lXKWFRmZ5IjR3pzBstgsFnO52R uYArPqQsesBRP7YW965Eg0m3VEXdzOf8oPbI6vcAwZrSM7mfCE4aX5LAL72YvI6tdeWP3yUSWj7c5 URZYD4DMtFJ1uMeynr9Ve3GoDTLrHOGVZ2ethFwho0Sa3YyYLHBMCgOzsBpMzxw5Iq1/JxDaFqZEh PxN0SZgfcGHGdYLEi4p1sHKef80ulTsN9BpDq4h0aNg/Flg1KaAY72QdH73W6K+JCHFHGrmje93lm fvrrsKahFK29Ut4dx8+xzgxtVTHnyNkcby6gTGMUQ15UK7d45JXExd5iVZyj2ncDF422uNdaOOtPY bDw2XvGA==; Received: from [2001:4bb8:188:2b00:20e6:8b5a:ed96:f9da] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1ieFV4-0002gt-Lk; Mon, 09 Dec 2019 09:38:43 +0000 From: Christoph Hellwig To: colyli@suse.de Cc: kent.overstreet@gmail.com, liangchen.linux@gmail.com, linux-bcache@vger.kernel.org, linux-block@vger.kernel.org Subject: [PATCH 4/7] bcache: transfer the sb_page reference to register_{bdev,cache} Date: Mon, 9 Dec 2019 10:38:26 +0100 Message-Id: <20191209093829.19703-5-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191209093829.19703-1-hch@lst.de> References: <20191209093829.19703-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Avoid an extra reference count roundtrip by transferring the sb_page ownership to the lower level register helpers. Signed-off-by: Christoph Hellwig --- drivers/md/bcache/super.c | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index e8013e1b0a14..c11bc0135ae6 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1368,8 +1368,6 @@ static int register_bdev(struct cache_sb *sb, struct page *sb_page, bio_init(&dc->sb_bio, dc->sb_bio.bi_inline_vecs, 1); bio_first_bvec_all(&dc->sb_bio)->bv_page = sb_page; - get_page(sb_page); - if (cached_dev_init(dc, sb->block_size << 9)) goto err; @@ -2275,7 +2273,6 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page, bio_init(&ca->sb_bio, ca->sb_bio.bi_inline_vecs, 1); bio_first_bvec_all(&ca->sb_bio)->bv_page = sb_page; - get_page(sb_page); if (blk_queue_discard(bdev_get_queue(bdev))) ca->discard = CACHE_DISCARD(&ca->sb); @@ -2378,7 +2375,7 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, const char *err; char *path; struct cache_sb *sb; - struct block_device *bdev = NULL; + struct block_device *bdev; struct page *sb_page; ssize_t ret; @@ -2442,10 +2439,8 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, ret = register_bdev(sb, sb_page, bdev, dc); mutex_unlock(&bch_register_lock); /* blkdev_put() will be called in cached_dev_free() */ - if (ret < 0) { - bdev = NULL; - goto out_put_sb_page; - } + if (ret < 0) + goto out_free_sb; } else { struct cache *ca = kzalloc(sizeof(*ca), GFP_KERNEL); @@ -2453,13 +2448,10 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, goto out_put_sb_page; /* blkdev_put() will be called in bch_cache_release() */ - if (register_cache(sb, sb_page, bdev, ca) != 0) { - bdev = NULL; - goto out_put_sb_page; - } + if (register_cache(sb, sb_page, bdev, ca) != 0) + goto out_free_sb; } - put_page(sb_page); done: kfree(sb); kfree(path); @@ -2469,8 +2461,7 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, out_put_sb_page: put_page(sb_page); out_blkdev_put: - if (bdev) - blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL); + blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL); out_free_sb: kfree(sb); out_free_path: