[CRIU] [PATCH 2/3] cg: allow properties that aren't integers

[Pavel Emelyanov]

On 08/22/2014 04:49 PM, Tycho Andersen wrote:
> On Fri, Aug 22, 2014 at 01:10:21PM +0400, Pavel Emelyanov wrote:
>> On 08/22/2014 01:00 AM, Tycho Andersen wrote:
>>> In particular, cpuset.cpus and cpuset.mems can both be "lists" (strings), as
>>> well as hex integers. We don't use the result of this parse, so it is fine to delete it.
>>>
>>> Signed-off-by: Tycho Andersen <tycho.andersen at canonical.com>
>>> ---
>>>  cgroup.c | 14 +++-----------
>>>  1 file changed, 3 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/cgroup.c b/cgroup.c
>>> index c5ae154..b821762 100644
>>> --- a/cgroup.c
>>> +++ b/cgroup.c
>>> @@ -295,12 +295,12 @@ static inline char *strip(char *str)
>>>  }
>>>  
>>>  /*
>>> - * Currently this function only supports properties that have 1 value, under 100
>>> - * chars
>>> + * Currently this function only supports properties that have a string value
>>> + * under 1024 chars.
>>>   */
>>>  static int read_cgroup_prop(struct cgroup_prop *property, const char *fullpath)
>>>  {
>>> -	char buf[100];
>>> +	char buf[1024];
>>>  	FILE *f;
>>>  	char *endptr;
>>>  
>>> @@ -325,14 +325,6 @@ static int read_cgroup_prop(struct cgroup_prop *property, const char *fullpath)
>>>  		return -1;
>>>  	}
>>>  
>>> -	if (strtoll(buf, &endptr, 10) == LLONG_MAX)
>>> -		strcpy(buf, "-1");
>>> -
>>> -	if (strcmp(endptr, "\n")) {
>>> -		pr_perror("Failed parsing %s, with strtoll\n", buf);
>>> -		return -1;
>>> -	}
>>
>> This code is required to properly handle the memory controller's unlimited value.
>> See commit a152c843b8af67bf8cbb3254a4b50f8e7a8b1104
> 
> Ah, whoops. Do we have any idea why the write fails?

AFAIU it's the kernel. It doesn't accept bug values, asking for "-1" to
denote "unlimited", but shows the LLONG_MAX on read.

> I guess we don't need to delete the strtoll test, just the strcmp is
> what breaks things.

OK, will you re-send the fixed patch?

> Tycho
> 
>>> -
>>>  	property->value = xstrdup(strip(buf));
>>>  	if (!property->value)
>>>  		return -1;
>>>
>>
> .
>