From patchwork Tue May 10 21:02:12 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Valente X-Patchwork-Id: 67474 Delivered-To: patch@linaro.org Received: by 10.140.92.199 with SMTP id b65csp2336024qge; Tue, 10 May 2016 14:02:35 -0700 (PDT) X-Received: by 10.98.69.132 with SMTP id n4mr60615651pfi.53.1462914155064; Tue, 10 May 2016 14:02:35 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id o25si4692869pfa.151.2016.05.10.14.02.34; Tue, 10 May 2016 14:02:35 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=fail (p=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751800AbcEJVCd (ORCPT + 3 others); Tue, 10 May 2016 17:02:33 -0400 Received: from spostino.sms.unimo.it ([155.185.44.3]:41206 "EHLO spostino.sms.unimo.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751410AbcEJVCd (ORCPT ); Tue, 10 May 2016 17:02:33 -0400 Received: from [185.14.10.204] (port=33765 helo=localhost.localdomain) by spostino.sms.unimo.it with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA256:128) (Exim 4.80) (envelope-from ) id 1b0EnT-0008VQ-R5; Tue, 10 May 2016 23:02:28 +0200 From: Paolo Valente To: Jens Axboe , Tejun Heo Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, ulf.hansson@linaro.org, linus.walleij@linaro.org, broonie@kernel.org, stable@vger.kernel.org, Paolo Valente Subject: [PATCH BUGFIX V2] block: add missing group association in bio-cloning functions Date: Tue, 10 May 2016 23:02:12 +0200 Message-Id: <1462914132-4479-1-git-send-email-paolo.valente@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <20160510204435.GN7110@mtj.duckdns.org> References: <20160510204435.GN7110@mtj.duckdns.org> UNIMORE-X-SA-Score: -2.9 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org When a bio is cloned, the newly created bio must be associated with the same blkcg as the original bio (if BLK_CGROUP is enabled). If this operation is not performed, then the new bio is not associated with any group, and the group of the current task is returned when the group of the bio is requested. Depending on the cloning frequency, this may cause a large percentage of the bios belonging to a given group to be treated as if belonging to other groups (in most cases as if belonging to the root group). The expected group isolation may thereby be broken. This commit adds the missing association in bio-cloning functions. Signed-off-by: Paolo Valente --- block/bio.c | 17 +++++++++++++++++ fs/btrfs/extent_io.c | 6 ------ include/linux/bio.h | 3 +++ 3 files changed, 20 insertions(+), 6 deletions(-) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/block/bio.c b/block/bio.c index 807d25e..e9b136a 100644 --- a/block/bio.c +++ b/block/bio.c @@ -622,6 +622,8 @@ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) } } + bio_clone_blkcg_association(b, bio); + return b; } EXPORT_SYMBOL(bio_clone_fast); @@ -695,6 +697,8 @@ integrity_clone: } } + bio_clone_blkcg_association(bio, bio_src); + return bio; } EXPORT_SYMBOL(bio_clone_bioset); @@ -1811,6 +1815,8 @@ struct bio *bio_split(struct bio *bio, int sectors, bio_advance(bio, split->bi_iter.bi_size); + bio_clone_blkcg_association(split, bio); + return split; } EXPORT_SYMBOL(bio_split); @@ -2016,6 +2022,17 @@ void bio_disassociate_task(struct bio *bio) } } +/** + * bio_clone_blkcg_association - clone blkcg association from src to dst bio + * @dst: destination bio + * @src: source bio + */ +void bio_clone_blkcg_association(struct bio *dst, struct bio *src) +{ + if (src->bi_css) + WARN_ON(bio_associate_blkcg(dst, src->bi_css)); +} + #endif /* CONFIG_BLK_CGROUP */ static void __init biovec_init_slabs(void) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index d247fc0..19f6739 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2686,12 +2686,6 @@ struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask) btrfs_bio->csum = NULL; btrfs_bio->csum_allocated = NULL; btrfs_bio->end_io = NULL; - -#ifdef CONFIG_BLK_CGROUP - /* FIXME, put this into bio_clone_bioset */ - if (bio->bi_css) - bio_associate_blkcg(new, bio->bi_css); -#endif } return new; } diff --git a/include/linux/bio.h b/include/linux/bio.h index 6b7481f..16cbe59 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -527,11 +527,14 @@ extern unsigned int bvec_nr_vecs(unsigned short idx); int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css); int bio_associate_current(struct bio *bio); void bio_disassociate_task(struct bio *bio); +void bio_clone_blkcg_association(struct bio *dst, struct bio *src); #else /* CONFIG_BLK_CGROUP */ static inline int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) { return 0; } static inline int bio_associate_current(struct bio *bio) { return -ENOENT; } static inline void bio_disassociate_task(struct bio *bio) { } +static inline void bio_clone_blkcg_association(struct bio *dst, + struct bio *src) { return 0; } #endif /* CONFIG_BLK_CGROUP */ #ifdef CONFIG_HIGHMEM