From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946496AbbEVVab (ORCPT ); Fri, 22 May 2015 17:30:31 -0400 Received: from mail-qk0-f174.google.com ([209.85.220.174]:34698 "EHLO mail-qk0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757732AbbEVVOd (ORCPT ); Fri, 22 May 2015 17:14:33 -0400 From: Tejun Heo To: axboe@kernel.dk Cc: linux-kernel@vger.kernel.org, jack@suse.cz, hch@infradead.org, hannes@cmpxchg.org, linux-fsdevel@vger.kernel.org, vgoyal@redhat.com, lizefan@huawei.com, cgroups@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.cz, clm@fb.com, fengguang.wu@intel.com, david@fromorbit.com, gthelen@google.com, khlebnikov@yandex-team.ru, Tejun Heo Subject: [PATCH 10/51] blkcg: implement bio_associate_blkcg() Date: Fri, 22 May 2015 17:13:24 -0400 Message-Id: <1432329245-5844-11-git-send-email-tj@kernel.org> X-Mailer: git-send-email 2.4.0 In-Reply-To: <1432329245-5844-1-git-send-email-tj@kernel.org> References: <1432329245-5844-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, a bio can only be associated with the io_context and blkcg of %current using bio_associate_current(). This is too restrictive for cgroup writeback support. Implement bio_associate_blkcg() which associates a bio with the specified blkcg. bio_associate_blkcg() leaves the io_context unassociated. bio_associate_current() is updated so that it considers a bio as already associated if it has a blkcg_css, instead of an io_context, associated with it. Signed-off-by: Tejun Heo Cc: Jens Axboe Cc: Vivek Goyal --- block/bio.c | 24 +++++++++++++++++++++++- include/linux/bio.h | 3 +++ 2 files changed, 26 insertions(+), 1 deletion(-) diff --git a/block/bio.c b/block/bio.c index cb7faac..494ffdb 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1995,6 +1995,28 @@ struct bio_set *bioset_create_nobvec(unsigned int pool_size, unsigned int front_ EXPORT_SYMBOL(bioset_create_nobvec); #ifdef CONFIG_BLK_CGROUP + +/** + * bio_associate_blkcg - associate a bio with the specified blkcg + * @bio: target bio + * @blkcg_css: css of the blkcg to associate + * + * Associate @bio with the blkcg specified by @blkcg_css. Block layer will + * treat @bio as if it were issued by a task which belongs to the blkcg. + * + * This function takes an extra reference of @blkcg_css which will be put + * when @bio is released. The caller must own @bio and is responsible for + * synchronizing calls to this function. + */ +int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) +{ + if (unlikely(bio->bi_css)) + return -EBUSY; + css_get(blkcg_css); + bio->bi_css = blkcg_css; + return 0; +} + /** * bio_associate_current - associate a bio with %current * @bio: target bio @@ -2012,7 +2034,7 @@ int bio_associate_current(struct bio *bio) { struct io_context *ioc; - if (bio->bi_ioc) + if (bio->bi_css) return -EBUSY; ioc = current->io_context; diff --git a/include/linux/bio.h b/include/linux/bio.h index 7486ea1..14260d1 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -483,9 +483,12 @@ extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int); extern unsigned int bvec_nr_vecs(unsigned short idx); #ifdef CONFIG_BLK_CGROUP +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); #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) { } #endif /* CONFIG_BLK_CGROUP */ -- 2.4.0 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 10/51] blkcg: implement bio_associate_blkcg() Date: Fri, 22 May 2015 17:13:24 -0400 Message-ID: <1432329245-5844-11-git-send-email-tj@kernel.org> References: <1432329245-5844-1-git-send-email-tj@kernel.org> Cc: linux-kernel@vger.kernel.org, jack@suse.cz, hch@infradead.org, hannes@cmpxchg.org, linux-fsdevel@vger.kernel.org, vgoyal@redhat.com, lizefan@huawei.com, cgroups@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.cz, clm@fb.com, fengguang.wu@intel.com, david@fromorbit.com, gthelen@google.com, khlebnikov@yandex-team.ru, Tejun Heo To: axboe@kernel.dk Return-path: In-Reply-To: <1432329245-5844-1-git-send-email-tj@kernel.org> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org Currently, a bio can only be associated with the io_context and blkcg of %current using bio_associate_current(). This is too restrictive for cgroup writeback support. Implement bio_associate_blkcg() which associates a bio with the specified blkcg. bio_associate_blkcg() leaves the io_context unassociated. bio_associate_current() is updated so that it considers a bio as already associated if it has a blkcg_css, instead of an io_context, associated with it. Signed-off-by: Tejun Heo Cc: Jens Axboe Cc: Vivek Goyal --- block/bio.c | 24 +++++++++++++++++++++++- include/linux/bio.h | 3 +++ 2 files changed, 26 insertions(+), 1 deletion(-) diff --git a/block/bio.c b/block/bio.c index cb7faac..494ffdb 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1995,6 +1995,28 @@ struct bio_set *bioset_create_nobvec(unsigned int pool_size, unsigned int front_ EXPORT_SYMBOL(bioset_create_nobvec); #ifdef CONFIG_BLK_CGROUP + +/** + * bio_associate_blkcg - associate a bio with the specified blkcg + * @bio: target bio + * @blkcg_css: css of the blkcg to associate + * + * Associate @bio with the blkcg specified by @blkcg_css. Block layer will + * treat @bio as if it were issued by a task which belongs to the blkcg. + * + * This function takes an extra reference of @blkcg_css which will be put + * when @bio is released. The caller must own @bio and is responsible for + * synchronizing calls to this function. + */ +int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) +{ + if (unlikely(bio->bi_css)) + return -EBUSY; + css_get(blkcg_css); + bio->bi_css = blkcg_css; + return 0; +} + /** * bio_associate_current - associate a bio with %current * @bio: target bio @@ -2012,7 +2034,7 @@ int bio_associate_current(struct bio *bio) { struct io_context *ioc; - if (bio->bi_ioc) + if (bio->bi_css) return -EBUSY; ioc = current->io_context; diff --git a/include/linux/bio.h b/include/linux/bio.h index 7486ea1..14260d1 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -483,9 +483,12 @@ extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int); extern unsigned int bvec_nr_vecs(unsigned short idx); #ifdef CONFIG_BLK_CGROUP +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); #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) { } #endif /* CONFIG_BLK_CGROUP */ -- 2.4.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org