[LTP] [PATCH v3 2/3] tst_cgroup: Add safe_cg_open and safe_cg_fchown functions

[Richard Palethorpe]

Richard Palethorpe <rpalethorpe@suse.de> writes:

> Hello,
>
> Yang Xu <xuyang2018.jy@fujitsu.com> writes:
>
>> safe_cg_open is used to open the sub control's file ie cgroup.procs
>> and returns the opened fd number. The opened fd array is stored in
>> fds argument.
>>
>> safe_cg_fchown is used to use fchownat to change file's uid and gid.
>>
>> Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
>> ---
>>  include/tst_cgroup.h | 44 +++++++++++++++++++++++++++++
>>  lib/tst_cgroup.c     | 66 +++++++++++++++++++++++++++-----------------
>>  2 files changed, 85 insertions(+), 25 deletions(-)
>>
>> diff --git a/include/tst_cgroup.h b/include/tst_cgroup.h
>> index d06847cc6..70c5b3fd4 100644
>> --- a/include/tst_cgroup.h
>> +++ b/include/tst_cgroup.h
>> @@ -89,6 +89,32 @@ enum tst_cg_ver {
>>  	TST_CG_V2 = 2,
>>  };
>>  
>> +/* Controller sub-systems */
>> +enum cgroup_ctrl_indx {
>> +	CTRL_MEMORY = 1,
>> +	CTRL_CPU,
>> +	CTRL_CPUSET,
>> +	CTRL_IO,
>> +	CTRL_PIDS,
>> +	CTRL_HUGETLB,
>> +	CTRL_CPUACCT,
>> +	CTRL_DEVICES,
>> +	CTRL_FREEZER,
>> +	CTRL_NETCLS,
>> +	CTRL_NETPRIO,
>> +	CTRL_BLKIO,
>> +	CTRL_MISC,
>> +	CTRL_PERFEVENT,
>> +	CTRL_DEBUG
>> +};
>> +
>> +#define CTRLS_MAX CTRL_DEBUG
>> +
>> +/* At most we can have one cgroup V1 tree for each controller and one
>> + * (empty) v2 tree.
>> + */
>> +#define ROOTS_MAX (CTRLS_MAX + 1)
>
> These need TST_CG_ prepending to them to stop name collisions.

Actually, I think the easiest thing to do is not export these. Instead
you could leave these alone and export "#define TST_CG_ROOTS_MAX 32".

The rest of the patch-set looks great.

-- 
Thank you,
Richard.