| Message ID | 20220602133543.128088-3-longman@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | None | expand |
On Thu, Jun 02, 2022 at 09:35:42AM -0400, Waiman Long wrote: > 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> Acked-by: Tejun Heo <tj@kernel.org> But I don't understand why this would trigger warning. Can you please elaborate why this is needed. Thanks.
On 6/2/22 12:16, Tejun Heo wrote: > On Thu, Jun 02, 2022 at 09:35:42AM -0400, Waiman Long wrote: >> 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> > Acked-by: Tejun Heo <tj@kernel.org> > > But I don't understand why this would trigger warning. Can you please > elaborate why this is needed. > > Thanks. I forgot to set "ret" in my original patch 2 in case of allocation error. I didn't got a warning in my own build, maybe I didn't explicitly enable more warning. I could have modified the patch to set "ret" on error, but the "ret" setting looks duplicative to me and so I added this patch to get rid of it. Thanks, Longman
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)
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(-)