From: Waiman Long <longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Jens Axboe <axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Ming Lei <ming.lei-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Waiman Long <longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Subject: [PATCH v6 2/3] blk-cgroup: Return -ENOMEM directly in blkcg_css_alloc() error path
Date: Thu, 2 Jun 2022 15:20:19 -0400 [thread overview]
Message-ID: <20220602192020.166940-3-longman@redhat.com> (raw)
In-Reply-To: <20220602192020.166940-1-longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
For blkcg_css_alloc(), the only error that will be returned is -ENOMEM.
Simplify error handling code by returning this error directly instead
of setting an intermediate "ret" variable.
Signed-off-by: Waiman Long <longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
block/blk-cgroup.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index acd9b0aa8dc8..9021f75fc752 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1177,7 +1177,6 @@ static struct cgroup_subsys_state *
blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct blkcg *blkcg;
- struct cgroup_subsys_state *ret;
int i;
mutex_lock(&blkcg_pol_mutex);
@@ -1186,10 +1185,8 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
blkcg = &blkcg_root;
} else {
blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
- if (!blkcg) {
- ret = ERR_PTR(-ENOMEM);
+ if (!blkcg)
goto unlock;
- }
}
for (i = 0; i < BLKCG_MAX_POLS ; i++) {
@@ -1206,10 +1203,9 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
continue;
cpd = pol->cpd_alloc_fn(GFP_KERNEL);
- if (!cpd) {
- ret = ERR_PTR(-ENOMEM);
+ if (!cpd)
goto free_pd_blkcg;
- }
+
blkcg->cpd[i] = cpd;
cpd->blkcg = blkcg;
cpd->plid = i;
@@ -1238,7 +1234,7 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
kfree(blkcg);
unlock:
mutex_unlock(&blkcg_pol_mutex);
- return ret;
+ return ERR_PTR(-ENOMEM);
}
static int blkcg_css_online(struct cgroup_subsys_state *css)
--
2.31.1
WARNING: multiple messages have this Message-ID (diff)
From: Waiman Long <longman@redhat.com>
To: Tejun Heo <tj@kernel.org>, Jens Axboe <axboe@kernel.dk>
Cc: cgroups@vger.kernel.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org, Ming Lei <ming.lei@redhat.com>,
Waiman Long <longman@redhat.com>
Subject: [PATCH v6 2/3] blk-cgroup: Return -ENOMEM directly in blkcg_css_alloc() error path
Date: Thu, 2 Jun 2022 15:20:19 -0400 [thread overview]
Message-ID: <20220602192020.166940-3-longman@redhat.com> (raw)
In-Reply-To: <20220602192020.166940-1-longman@redhat.com>
For blkcg_css_alloc(), the only error that will be returned is -ENOMEM.
Simplify error handling code by returning this error directly instead
of setting an intermediate "ret" variable.
Signed-off-by: Waiman Long <longman@redhat.com>
---
block/blk-cgroup.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index acd9b0aa8dc8..9021f75fc752 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1177,7 +1177,6 @@ static struct cgroup_subsys_state *
blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct blkcg *blkcg;
- struct cgroup_subsys_state *ret;
int i;
mutex_lock(&blkcg_pol_mutex);
@@ -1186,10 +1185,8 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
blkcg = &blkcg_root;
} else {
blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
- if (!blkcg) {
- ret = ERR_PTR(-ENOMEM);
+ if (!blkcg)
goto unlock;
- }
}
for (i = 0; i < BLKCG_MAX_POLS ; i++) {
@@ -1206,10 +1203,9 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
continue;
cpd = pol->cpd_alloc_fn(GFP_KERNEL);
- if (!cpd) {
- ret = ERR_PTR(-ENOMEM);
+ if (!cpd)
goto free_pd_blkcg;
- }
+
blkcg->cpd[i] = cpd;
cpd->blkcg = blkcg;
cpd->plid = i;
@@ -1238,7 +1234,7 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
kfree(blkcg);
unlock:
mutex_unlock(&blkcg_pol_mutex);
- return ret;
+ return ERR_PTR(-ENOMEM);
}
static int blkcg_css_online(struct cgroup_subsys_state *css)
--
2.31.1
next prev parent reply other threads:[~2022-06-02 19:20 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-02 19:20 [PATCH v6 0/3] blk-cgroup: Optimize blkcg_rstat_flush() Waiman Long
2022-06-02 19:20 ` Waiman Long
[not found] ` <20220602192020.166940-1-longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2022-06-02 19:20 ` [PATCH v6 1/3] blk-cgroup: Correctly free percpu iostat_cpu in blkg on error exit Waiman Long
2022-06-02 19:20 ` Waiman Long
[not found] ` <20220602192020.166940-2-longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2022-06-04 2:08 ` Ming Lei
2022-06-04 2:08 ` Ming Lei
2022-06-04 2:47 ` Waiman Long
2022-06-02 19:20 ` Waiman Long [this message]
2022-06-02 19:20 ` [PATCH v6 2/3] blk-cgroup: Return -ENOMEM directly in blkcg_css_alloc() error path Waiman Long
2022-06-02 20:39 ` Tejun Heo
[not found] ` <20220602192020.166940-3-longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2022-06-04 2:16 ` Ming Lei
2022-06-04 2:16 ` Ming Lei
2022-06-02 19:20 ` [PATCH v6 3/3] blk-cgroup: Optimize blkcg_rstat_flush() Waiman Long
2022-06-04 3:58 ` Ming Lei
2022-06-05 23:15 ` Waiman Long
2022-06-06 1:39 ` Ming Lei
2022-06-06 1:59 ` Waiman Long
2022-06-06 1:59 ` Waiman Long
2022-06-06 2:23 ` Ming Lei
2022-06-06 2:58 ` Waiman Long
2022-06-06 2:58 ` Waiman Long
2022-06-06 3:15 ` Ming Lei
[not found] ` <20220602192020.166940-4-longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2022-06-06 3:16 ` Ming Lei
2022-06-06 3:16 ` Ming Lei
2022-06-08 16:57 ` Michal Koutný
2022-06-08 16:57 ` Michal Koutný
2022-06-08 18:16 ` Waiman Long
2022-06-08 21:12 ` Michal Koutný
2022-06-08 22:14 ` Michal Koutný
2022-09-30 18:34 ` Waiman Long
2022-09-30 18:34 ` Waiman Long
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