From patchwork Tue May 10 20:23:41 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Valente X-Patchwork-Id: 9062621 Return-Path: X-Original-To: patchwork-linux-block@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id CC2579F1D3 for ; Tue, 10 May 2016 20:24:17 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DEE51200E6 for ; Tue, 10 May 2016 20:24:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DCF15201B9 for ; Tue, 10 May 2016 20:24:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751479AbcEJUYP (ORCPT ); Tue, 10 May 2016 16:24:15 -0400 Received: from smtp26.sms.unimo.it ([155.185.44.26]:50416 "EHLO smtp26.sms.unimo.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751227AbcEJUYO (ORCPT ); Tue, 10 May 2016 16:24:14 -0400 Received: from [185.14.10.204] (port=41058 helo=localhost.localdomain) by smtp26.sms.unimo.it with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA256:128) (Exim 4.80) (envelope-from ) id 1b0ECN-0004vl-Lm; Tue, 10 May 2016 22:24:09 +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] block: add missing group association in bio-cloning functions Date: Tue, 10 May 2016 22:23:41 +0200 Message-Id: <1462911821-7354-1-git-send-email-paolo.valente@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: References: UNIMORE-X-SA-Score: -2.9 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Spam-Status: No, score=-9.0 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 | 2 ++ 3 files changed, 19 insertions(+), 6 deletions(-) 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..a9ff116 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -527,11 +527,13 @@ 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) { } +void bio_clone_blkcg_association(struct bio *dst, struct bio *src) { return 0; } #endif /* CONFIG_BLK_CGROUP */ #ifdef CONFIG_HIGHMEM