From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754819AbbGXSoF (ORCPT ); Fri, 24 Jul 2015 14:44:05 -0400 Received: from mail-yk0-f172.google.com ([209.85.160.172]:35671 "EHLO mail-yk0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754752AbbGXSoB (ORCPT ); Fri, 24 Jul 2015 14:44:01 -0400 From: Tejun Heo To: axboe@kernel.dk Cc: vgoyal@redhat.com, linux-kernel@vger.kernel.org, avanzini.arianna@gmail.com, kernel-team@fb.com, hannes@cmpxchg.org, lizefan@huawei.com, cgroups@vger.kernel.org, Tejun Heo Subject: [PATCH 04/10] blkcg: refine error codes returned during blkcg configuration Date: Fri, 24 Jul 2015 14:43:48 -0400 Message-Id: <1437763434-28699-5-git-send-email-tj@kernel.org> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1437763434-28699-1-git-send-email-tj@kernel.org> References: <1437763434-28699-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org blkcg currently returns -EINVAL for most errors which can be pretty confusing given that the failure modes are quite varied. Update the error returns so that * -EINVAL only for syntactic errors. * -ERANGE if the value is out of range. * -ENODEV if the target device can't be found. * -EOPNOTSUPP if the policy is not enabled on the target device. Signed-off-by: Tejun Heo --- block/blk-cgroup.c | 12 ++++++------ block/cfq-iosched.c | 2 +- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 63c0914..a192f98 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -179,7 +179,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, /* blkg holds a reference to blkcg */ if (!css_tryget_online(&blkcg->css)) { - ret = -EINVAL; + ret = -ENODEV; goto err_free_blkg; } @@ -205,7 +205,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, if (blkcg_parent(blkcg)) { blkg->parent = __blkg_lookup(blkcg_parent(blkcg), q, false); if (WARN_ON_ONCE(!blkg->parent)) { - ret = -EINVAL; + ret = -ENODEV; goto err_put_congested; } blkg_get(blkg->parent); @@ -279,7 +279,7 @@ struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, * we shouldn't allow anything to go through for a bypassing queue. */ if (unlikely(blk_queue_bypass(q))) - return ERR_PTR(blk_queue_dying(q) ? -EINVAL : -EBUSY); + return ERR_PTR(blk_queue_dying(q) ? -ENODEV : -EBUSY); blkg = __blkg_lookup(blkcg, q, true); if (blkg) @@ -792,10 +792,10 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, disk = get_gendisk(MKDEV(major, minor), &part); if (!disk) - return -EINVAL; + return -ENODEV; if (part) { put_disk(disk); - return -EINVAL; + return -ENODEV; } rcu_read_lock(); @@ -804,7 +804,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, if (blkcg_policy_enabled(disk->queue, pol)) blkg = blkg_lookup_create(blkcg, disk->queue); else - blkg = ERR_PTR(-EINVAL); + blkg = ERR_PTR(-EOPNOTSUPP); if (IS_ERR(blkg)) { ret = PTR_ERR(blkg); diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index bcf4026..38277e3 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1755,7 +1755,7 @@ static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of, cfqg = blkg_to_cfqg(ctx.blkg); cfqgd = blkcg_to_cfqgd(blkcg); - ret = -EINVAL; + ret = -ERANGE; if (!ctx.v || (ctx.v >= CFQ_WEIGHT_MIN && ctx.v <= CFQ_WEIGHT_MAX)) { if (!is_leaf_weight) { cfqg->dev_weight = ctx.v; -- 2.4.3