* [PATCH] cpuset: Add a missing unlock in cpuset_write_resmask()
@ 2011-02-24 6:58 Li Zefan
2011-02-24 7:05 ` David Rientjes
2011-02-28 23:55 ` Andrew Morton
0 siblings, 2 replies; 4+ messages in thread
From: Li Zefan @ 2011-02-24 6:58 UTC (permalink / raw)
To: Andrew Morton
Cc: Paul Menage, David Rientjes, 缪 勰, LKML, linux-mm
Don't forget to release cgroup_mutex if alloc_trial_cpuset() fails.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
kernel/cpuset.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 1ca786a..6272503 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1561,8 +1561,10 @@ static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft,
return -ENODEV;
trialcs = alloc_trial_cpuset(cs);
- if (!trialcs)
+ if (!trialcs) {
+ cgroup_unlock();
return -ENOMEM;
+ }
switch (cft->private) {
case FILE_CPULIST:
--
1.7.3.1
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^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] cpuset: Add a missing unlock in cpuset_write_resmask()
2011-02-24 6:58 [PATCH] cpuset: Add a missing unlock in cpuset_write_resmask() Li Zefan
@ 2011-02-24 7:05 ` David Rientjes
2011-02-28 23:55 ` Andrew Morton
1 sibling, 0 replies; 4+ messages in thread
From: David Rientjes @ 2011-02-24 7:05 UTC (permalink / raw)
To: Li Zefan; +Cc: Andrew Morton, Paul Menage, miaox, linux-kernel, linux-mm
On Thu, 24 Feb 2011, Li Zefan wrote:
> Don't forget to release cgroup_mutex if alloc_trial_cpuset() fails.
>
> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] cpuset: Add a missing unlock in cpuset_write_resmask()
2011-02-24 6:58 [PATCH] cpuset: Add a missing unlock in cpuset_write_resmask() Li Zefan
2011-02-24 7:05 ` David Rientjes
@ 2011-02-28 23:55 ` Andrew Morton
2011-03-01 1:05 ` Li Zefan
1 sibling, 1 reply; 4+ messages in thread
From: Andrew Morton @ 2011-02-28 23:55 UTC (permalink / raw)
To: Li Zefan; +Cc: Paul Menage, David Rientjes, 缪 勰, LKML, linux-mm
On Thu, 24 Feb 2011 14:58:58 +0800
Li Zefan <lizf@cn.fujitsu.com> wrote:
> Don't forget to release cgroup_mutex if alloc_trial_cpuset() fails.
>
> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
> ---
> kernel/cpuset.c | 4 +++-
> 1 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/kernel/cpuset.c b/kernel/cpuset.c
> index 1ca786a..6272503 100644
> --- a/kernel/cpuset.c
> +++ b/kernel/cpuset.c
> @@ -1561,8 +1561,10 @@ static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft,
> return -ENODEV;
>
> trialcs = alloc_trial_cpuset(cs);
> - if (!trialcs)
> + if (!trialcs) {
> + cgroup_unlock();
> return -ENOMEM;
> + }
>
> switch (cft->private) {
> case FILE_CPULIST:
It would be better to avoid multiple returns - it leads to more
maintainable code and often shorter code:
--- a/kernel/cpuset.c~cpuset-add-a-missing-unlock-in-cpuset_write_resmask-fix
+++ a/kernel/cpuset.c
@@ -1562,8 +1562,8 @@ static int cpuset_write_resmask(struct c
trialcs = alloc_trial_cpuset(cs);
if (!trialcs) {
- cgroup_unlock();
- return -ENOMEM;
+ retval = -ENOMEM;
+ goto out;
}
switch (cft->private) {
@@ -1579,6 +1579,7 @@ static int cpuset_write_resmask(struct c
}
free_trial_cpuset(trialcs);
+out:
cgroup_unlock();
return retval;
}
_
also, alloc_trial_cpuset() is a fairly slow-looking function.
cpuset_write_resmask() could run alloc_trial_cpuset() before running
cgroup_lock_live_group(), thereby reducing lock hold times.
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] cpuset: Add a missing unlock in cpuset_write_resmask()
2011-02-28 23:55 ` Andrew Morton
@ 2011-03-01 1:05 ` Li Zefan
0 siblings, 0 replies; 4+ messages in thread
From: Li Zefan @ 2011-03-01 1:05 UTC (permalink / raw)
To: Andrew Morton
Cc: Paul Menage, David Rientjes, 缪 勰, LKML, linux-mm
>> @@ -1561,8 +1561,10 @@ static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft,
>> return -ENODEV;
>>
>> trialcs = alloc_trial_cpuset(cs);
>> - if (!trialcs)
>> + if (!trialcs) {
>> + cgroup_unlock();
>> return -ENOMEM;
>> + }
>>
>> switch (cft->private) {
>> case FILE_CPULIST:
>
> It would be better to avoid multiple returns - it leads to more
> maintainable code and often shorter code:
>
I have no strong opinion on this.
> --- a/kernel/cpuset.c~cpuset-add-a-missing-unlock-in-cpuset_write_resmask-fix
> +++ a/kernel/cpuset.c
> @@ -1562,8 +1562,8 @@ static int cpuset_write_resmask(struct c
>
> trialcs = alloc_trial_cpuset(cs);
> if (!trialcs) {
> - cgroup_unlock();
> - return -ENOMEM;
> + retval = -ENOMEM;
> + goto out;
> }
>
> switch (cft->private) {
> @@ -1579,6 +1579,7 @@ static int cpuset_write_resmask(struct c
> }
>
> free_trial_cpuset(trialcs);
> +out:
> cgroup_unlock();
> return retval;
> }
> _
>
> also, alloc_trial_cpuset() is a fairly slow-looking function.
> cpuset_write_resmask() could run alloc_trial_cpuset() before running
> cgroup_lock_live_group(), thereby reducing lock hold times.
>
Nope. alloc_trial_cpuset() will read 'cs', so it must be protected by
the lock.
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^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2011-03-01 1:03 UTC | newest]
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2011-02-24 6:58 [PATCH] cpuset: Add a missing unlock in cpuset_write_resmask() Li Zefan
2011-02-24 7:05 ` David Rientjes
2011-02-28 23:55 ` Andrew Morton
2011-03-01 1:05 ` Li Zefan
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