[PATCH 2/2] cpuset: remove redundant checks in file write functions

From: Li Zefan
Date: Mon Aug 12 2013 - 21:18:01 EST


Now cgroup core gets a reference to the css when a cgroup file is
opened(), and the reference is dropped at file release. so it's
guaranteed the cpuset is online during the write function.

Signed-off-by: Li Zefan <lizefan@xxxxxxxxxx>
---
kernel/cpuset.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 9d8d637..8c4b3c4 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1589,8 +1589,6 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
int retval = -ENODEV;

mutex_lock(&cpuset_mutex);
- if (!is_cpuset_online(cs))
- goto out_unlock;

switch (type) {
case FILE_CPU_EXCLUSIVE:
@@ -1624,7 +1622,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
retval = -EINVAL;
break;
}
-out_unlock:
+
mutex_unlock(&cpuset_mutex);
return retval;
}
@@ -1637,8 +1635,6 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
int retval = -ENODEV;

mutex_lock(&cpuset_mutex);
- if (!is_cpuset_online(cs))
- goto out_unlock;

switch (type) {
case FILE_SCHED_RELAX_DOMAIN_LEVEL:
@@ -1648,7 +1644,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
retval = -EINVAL;
break;
}
-out_unlock:
+
mutex_unlock(&cpuset_mutex);
return retval;
}
@@ -1677,8 +1673,6 @@ static int cpuset_write_resmask(struct cgroup_subsys_state *css,
flush_work(&cpuset_hotplug_work);

mutex_lock(&cpuset_mutex);
- if (!is_cpuset_online(cs))
- goto out_unlock;

trialcs = alloc_trial_cpuset(cs);
if (!trialcs) {
--
1.8.0.2
--
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