From patchwork Mon Nov 26 21:19:41 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dennis Zhou X-Patchwork-Id: 10699179 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AA61A16B1 for ; Mon, 26 Nov 2018 21:20:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 99E232A5FE for ; Mon, 26 Nov 2018 21:20:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8DC962A606; Mon, 26 Nov 2018 21:20:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EF9142A5E8 for ; Mon, 26 Nov 2018 21:20:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727606AbeK0IQF (ORCPT ); Tue, 27 Nov 2018 03:16:05 -0500 Received: from mail-yw1-f66.google.com ([209.85.161.66]:41855 "EHLO mail-yw1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727382AbeK0IP2 (ORCPT ); Tue, 27 Nov 2018 03:15:28 -0500 Received: by mail-yw1-f66.google.com with SMTP id f65so8200364ywc.8; Mon, 26 Nov 2018 13:20:02 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=XhaxLhrMJ/mdPT7cL1W8hrBAkSbRfFqEpjnsHRGlwHg=; b=DSqbjD9guOK4AWiWKMkkRnTxfHxAXqc0rqbds7MGZ/ziVknvTrW6pwN9nkUntMmUq9 sRXypJG848P8Wdqkw+r7ciOQq/Lu+VNVzRx/vZ6pDqgx3V8gRQetuKDgRxDMIYSfdvWP 4hV8Vb676A61lESO4npEFsQZ840cK8xYHfXaeak43bCI/5gg17TKf5msg3/1QzIoB/pv +FE60F3NssJciZz2/kQVRw9byJWr1dqnaDpCsq4p0J+ZqJKM/yjA/+1F2y3dLYy4AWNL IXU5MQwDJzm9LGYp43Lc5vUj/4EKdLPq1AGUeK6CLI0bcEN1qrqGAmokzMNHkFj7Ogso DGvA== X-Gm-Message-State: AGRZ1gIZ/WffgK97Hwwe+DKVArTBg3safUwJs78DSjWSosETrrz6F35u f7e7OxMEG1I9qn6rx3zdfmM= X-Google-Smtp-Source: AJdET5fKQnmbLbnwVxoMSyUKaoex3Apojo/NHtN3R2hTNeG4VXvVsFKof87u+x0VrhYIh2S7I0eqVQ== X-Received: by 2002:a81:65c5:: with SMTP id z188-v6mr31236906ywb.456.1543267201797; Mon, 26 Nov 2018 13:20:01 -0800 (PST) Received: from dennisz-mbp.thefacebook.com ([199.201.65.135]) by smtp.gmail.com with ESMTPSA id d135-v6sm495462ywh.43.2018.11.26.13.20.00 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 26 Nov 2018 13:20:01 -0800 (PST) From: Dennis Zhou To: Jens Axboe , Tejun Heo , Johannes Weiner , Josef Bacik Cc: kernel-team@fb.com, linux-block@vger.kernel.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Dennis Zhou Subject: [PATCH 08/13] blkcg: associate writeback bios with a blkg Date: Mon, 26 Nov 2018 16:19:41 -0500 Message-Id: <20181126211946.77067-9-dennis@kernel.org> X-Mailer: git-send-email 2.13.5 In-Reply-To: <20181126211946.77067-1-dennis@kernel.org> References: <20181126211946.77067-1-dennis@kernel.org> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP One of the goals of this series is to remove a separate reference to the css of the bio. This can and should be accessed via bio_blkcg. In this patch, wbc_init_bio() now requires a bio to have a device associated with it. Signed-off-by: Dennis Zhou Reviewed-by: Josef Bacik Acked-by: Tejun Heo --- Documentation/admin-guide/cgroup-v2.rst | 8 +++++--- block/bio.c | 21 +++++++++++++++++++++ fs/buffer.c | 10 +++++----- fs/ext4/page-io.c | 2 +- include/linux/bio.h | 5 +++++ include/linux/writeback.h | 5 +++-- 6 files changed, 40 insertions(+), 11 deletions(-) diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 476722b7b636..baf19bf28385 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1879,8 +1879,10 @@ following two functions. wbc_init_bio(@wbc, @bio) Should be called for each bio carrying writeback data and - associates the bio with the inode's owner cgroup. Can be - called anytime between bio allocation and submission. + associates the bio with the inode's owner cgroup and the + corresponding request queue. This must be called after + a queue (device) has been associated with the bio and + before submission. wbc_account_io(@wbc, @page, @bytes) Should be called for each data segment being written out. @@ -1899,7 +1901,7 @@ the configuration, the bio may be executed at a lower priority and if the writeback session is holding shared resources, e.g. a journal entry, may lead to priority inversion. There is no one easy solution for the problem. Filesystems can try to work around specific problem -cases by skipping wbc_init_bio() or using bio_associate_blkcg() +cases by skipping wbc_init_bio() and using bio_associate_blkg() directly. diff --git a/block/bio.c b/block/bio.c index 4600808ac606..e9e930b6a10c 100644 --- a/block/bio.c +++ b/block/bio.c @@ -2048,6 +2048,27 @@ static void __bio_associate_blkg_from_css(struct bio *bio, rcu_read_unlock(); } +/** + * bio_associate_blkg_from_css - associate a bio with a specified css + * @bio: target bio + * @css: target css + * + * Associate @bio with the blkg found by combining the css's blkg and the + * request_queue of the @bio. This takes a reference on the css that will + * be put upon freeing of @bio. + */ +void bio_associate_blkg_from_css(struct bio *bio, + struct cgroup_subsys_state *css) +{ + if (!bio_has_queue(bio)) + return; + + css_get(css); + bio->bi_css = css; + __bio_associate_blkg_from_css(bio, css); +} +EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css); + #ifdef CONFIG_MEMCG /** * bio_associate_blkg_from_page - associate a bio with the page's blkg diff --git a/fs/buffer.c b/fs/buffer.c index 9661e5be87e2..45452bd55c8e 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -3060,11 +3060,6 @@ static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh, */ bio = bio_alloc(GFP_NOIO, 1); - if (wbc) { - wbc_init_bio(wbc, bio); - wbc_account_io(wbc, bh->b_page, bh->b_size); - } - bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); bio_set_dev_only(bio, bh->b_bdev); bio->bi_write_hint = write_hint; @@ -3084,6 +3079,11 @@ static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh, op_flags |= REQ_PRIO; bio_set_op_attrs(bio, op, op_flags); + if (wbc) { + wbc_init_bio(wbc, bio); + wbc_account_io(wbc, bh->b_page, bh->b_size); + } + submit_bio(bio); return 0; } diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index cadf91a42fa5..ab383085fb5e 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -374,13 +374,13 @@ static int io_submit_init_bio(struct ext4_io_submit *io, bio = bio_alloc(GFP_NOIO, BIO_MAX_PAGES); if (!bio) return -ENOMEM; - wbc_init_bio(io->io_wbc, bio); bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); bio_set_dev_only(bio, bh->b_bdev); bio->bi_end_io = ext4_end_bio; bio->bi_private = ext4_get_io_end(io->io_end); io->io_bio = bio; io->io_next_block = bh->b_blocknr; + wbc_init_bio(io->io_wbc, bio); return 0; } diff --git a/include/linux/bio.h b/include/linux/bio.h index ad322232db3e..a9958f2bcb48 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -520,6 +520,8 @@ static inline void bio_associate_blkg_from_page(struct bio *bio, int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css); void bio_disassociate_blkg(struct bio *bio); void bio_associate_blkg(struct bio *bio); +void bio_associate_blkg_from_css(struct bio *bio, + struct cgroup_subsys_state *css); void bio_disassociate_task(struct bio *bio); void bio_clone_blkcg_association(struct bio *dst, struct bio *src); #else /* CONFIG_BLK_CGROUP */ @@ -527,6 +529,9 @@ static inline int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) { return 0; } static inline void bio_disassociate_blkg(struct bio *bio) { } static inline void bio_associate_blkg(struct bio *bio) { } +static inline void bio_associate_blkg_from_css(struct bio *bio, + struct cgroup_subsys_state *css) +{ } static inline void bio_disassociate_task(struct bio *bio) { } static inline void bio_clone_blkcg_association(struct bio *dst, struct bio *src) { } diff --git a/include/linux/writeback.h b/include/linux/writeback.h index fdfd04e348f6..738a0c24874f 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -246,7 +246,8 @@ static inline void wbc_attach_fdatawrite_inode(struct writeback_control *wbc, * * @bio is a part of the writeback in progress controlled by @wbc. Perform * writeback specific initialization. This is used to apply the cgroup - * writeback context. + * writeback context. Must be called after the bio has been associated with + * a device. */ static inline void wbc_init_bio(struct writeback_control *wbc, struct bio *bio) { @@ -257,7 +258,7 @@ static inline void wbc_init_bio(struct writeback_control *wbc, struct bio *bio) * regular writeback instead of writing things out itself. */ if (wbc->wb) - bio_associate_blkcg(bio, wbc->wb->blkcg_css); + bio_associate_blkg_from_css(bio, wbc->wb->blkcg_css); } #else /* CONFIG_CGROUP_WRITEBACK */