On 8/4/21 10:22 AM, Pavel Hrdina wrote:
> On Wed, Aug 04, 2021 at 10:06:17AM +0200, Michal Prívozník wrote:
>> On 8/3/21 4:29 PM, Pavel Hrdina wrote:
>>> For new feature Fibre Channel VMID we will need to get inode of the
>>> VM root cgroup as it is used in the new kernel API together with VMID.
>>>
>>> Signed-off-by: Pavel Hrdina <phrdina@xxxxxxxxxx>
>>> ---
>>> src/libvirt_private.syms | 1 +
>>> src/util/vircgroup.c | 37 +++++++++++++++++++++++++++++++++++++
>>> src/util/vircgroup.h | 2 ++
>>> 3 files changed, 40 insertions(+)
>>>
>>> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
>>> index 6961cdb137..d8451fcfff 100644
>>> --- a/src/libvirt_private.syms
>>> +++ b/src/libvirt_private.syms
>>> @@ -1920,6 +1920,7 @@ virCgroupGetCpuShares;
>>> virCgroupGetDevicePermsString;
>>> virCgroupGetDomainTotalCpuStats;
>>> virCgroupGetFreezerState;
>>> +virCgroupGetInode;
>>> virCgroupGetMemoryHardLimit;
>>> virCgroupGetMemorySoftLimit;
>>> virCgroupGetMemoryStat;
>>> diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c
>>> index 1b3b28342e..ea702e7b63 100644
>>> --- a/src/util/vircgroup.c
>>> +++ b/src/util/vircgroup.c
>>> @@ -3973,3 +3973,40 @@ virCgroupGetCpuPeriodQuota(virCgroup *cgroup, unsigned long long *period,
>>>
>>> return 0;
>>> }
>>> +
>>> +
>>> +/**
>>> + * virCgroupGetInode:
>>> + *
>>> + * @cgroup: the cgroup to get inode for
>>> + *
>>> + * Get the @cgroup inode and return its value to the caller.
>>> + *
>>> + * Returns inode on success, -1 on error with error message reported.
>>> + */
>>> +int
>>> +virCgroupGetInode(virCgroup *cgroup)
>>> +{
>>> + VIR_AUTOCLOSE fd = 0;
>>> + struct stat st;
>>> + int controller = virCgroupGetAnyController(cgroup);
>>> + g_autofree char *path = NULL;
>>> +
>>> + if (controller < 0)
>>> + return -1;
>>> +
>>> + if (virCgroupPathOfController(cgroup, controller, "", &path) < 0)
>>> + return -1;
>>> +
>>> + if ((fd = open(path, O_RDONLY | O_NONBLOCK)) < 0) {
>>> + virReportSystemError(errno, _("failed to open cgroup '%s'"), path);
>>> + return -1;
>>> + }
>>
>> Is the open() necessary? Why isn't plain stat() enough?
>
> Good question :) I was lazy so I looked for first similar code in
> libvirt codebase and copied it. You are right, stat should be enough
> as according to man page stat and fstat are identical except or the
> fd vs path parameter. I'll fix it before pushing or should I send a v2?
No need, just drop open() and switch to stat() before pushing. My
Reviewed-by still applies.
Michal
