[libvirt] [PATCH 05/53] vircgroup: introduce virCgroupV2CopyPlacement

Pavel Hrdina posted 53 patches 6 years, 7 months ago
There is a newer version of this series
[libvirt] [PATCH 05/53] vircgroup: introduce virCgroupV2CopyPlacement
Posted by Pavel Hrdina 6 years, 7 months ago
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
---
 src/util/vircgroupv2.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/src/util/vircgroupv2.c b/src/util/vircgroupv2.c
index d3f72b9006..11d9876d36 100644
--- a/src/util/vircgroupv2.c
+++ b/src/util/vircgroupv2.c
@@ -141,12 +141,39 @@ virCgroupV2CopyMounts(virCgroupPtr group,
 }
 
 
+static int
+virCgroupV2CopyPlacement(virCgroupPtr group,
+                         const char *path,
+                         virCgroupPtr parent)
+{
+    if (path[0] == '/') {
+        if (VIR_STRDUP(group->unified.placement, path) < 0)
+            return -1;
+    } else {
+        /*
+         * parent == "/" + path="" => "/"
+         * parent == "/libvirt.service" + path == "" => "/libvirt.service"
+         * parent == "/libvirt.service" + path == "foo" => "/libvirt.service/foo"
+         */
+        if (virAsprintf(&group->unified.placement, "%s%s%s",
+                        parent->unified.placement,
+                        (STREQ(parent->unified.placement, "/") ||
+                         STREQ(path, "") ? "" : "/"),
+                        path) < 0)
+            return -1;
+    }
+
+    return 0;
+}
+
+
 virCgroupBackend virCgroupV2Backend = {
     .type = VIR_CGROUP_BACKEND_TYPE_V2,
 
     .available = virCgroupV2Available,
     .validateMachineGroup = virCgroupV2ValidateMachineGroup,
     .copyMounts = virCgroupV2CopyMounts,
+    .copyPlacement = virCgroupV2CopyPlacement,
 };
 
 
-- 
2.17.1

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Re: [libvirt] [PATCH 05/53] vircgroup: introduce virCgroupV2CopyPlacement
Posted by Michal Privoznik 6 years, 7 months ago
On 10/02/2018 10:43 AM, Pavel Hrdina wrote:
> Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
> ---
>  src/util/vircgroupv2.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/src/util/vircgroupv2.c b/src/util/vircgroupv2.c
> index d3f72b9006..11d9876d36 100644
> --- a/src/util/vircgroupv2.c
> +++ b/src/util/vircgroupv2.c
> @@ -141,12 +141,39 @@ virCgroupV2CopyMounts(virCgroupPtr group,
>  }
>  
>  
> +static int
> +virCgroupV2CopyPlacement(virCgroupPtr group,
> +                         const char *path,
> +                         virCgroupPtr parent)
> +{
> +    if (path[0] == '/') {
> +        if (VIR_STRDUP(group->unified.placement, path) < 0)
> +            return -1;
> +    } else {

Maybe it's the lack of morning coffee, but I had some difficulties
parsing this.

> +        /*
> +         * parent == "/" + path="" => "/"
> +         * parent == "/libvirt.service" + path == "" => "/libvirt.service"
> +         * parent == "/libvirt.service" + path == "foo" => "/libvirt.service/foo"

s/\+/&&/ so that it looks like a C condition.

> +         */
> +        if (virAsprintf(&group->unified.placement, "%s%s%s",
> +                        parent->unified.placement,
> +                        (STREQ(parent->unified.placement, "/") ||
> +                         STREQ(path, "") ? "" : "/"),
> +                        path) < 0)

Maybe if you got rid of the ternary operator it would be more readable.
But now that I finally understood this, I don't care that much :-)

> +            return -1;
> +    }
> +
> +    return 0;
> +}
> +
> +
>  virCgroupBackend virCgroupV2Backend = {
>      .type = VIR_CGROUP_BACKEND_TYPE_V2,
>  
>      .available = virCgroupV2Available,
>      .validateMachineGroup = virCgroupV2ValidateMachineGroup,
>      .copyMounts = virCgroupV2CopyMounts,
> +    .copyPlacement = virCgroupV2CopyPlacement,
>  };
>  
>  
> 

ACK

Michal

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Re: [libvirt] [PATCH 05/53] vircgroup: introduce virCgroupV2CopyPlacement
Posted by Pavel Hrdina 6 years, 7 months ago
On Thu, Oct 04, 2018 at 01:18:27PM +0200, Michal Privoznik wrote:
> On 10/02/2018 10:43 AM, Pavel Hrdina wrote:
> > Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
> > ---
> >  src/util/vircgroupv2.c | 27 +++++++++++++++++++++++++++
> >  1 file changed, 27 insertions(+)
> > 
> > diff --git a/src/util/vircgroupv2.c b/src/util/vircgroupv2.c
> > index d3f72b9006..11d9876d36 100644
> > --- a/src/util/vircgroupv2.c
> > +++ b/src/util/vircgroupv2.c
> > @@ -141,12 +141,39 @@ virCgroupV2CopyMounts(virCgroupPtr group,
> >  }
> >  
> >  
> > +static int
> > +virCgroupV2CopyPlacement(virCgroupPtr group,
> > +                         const char *path,
> > +                         virCgroupPtr parent)
> > +{
> > +    if (path[0] == '/') {
> > +        if (VIR_STRDUP(group->unified.placement, path) < 0)
> > +            return -1;
> > +    } else {
> 
> Maybe it's the lack of morning coffee, but I had some difficulties
> parsing this.
> 
> > +        /*
> > +         * parent == "/" + path="" => "/"
> > +         * parent == "/libvirt.service" + path == "" => "/libvirt.service"
> > +         * parent == "/libvirt.service" + path == "foo" => "/libvirt.service/foo"
> 
> s/\+/&&/ so that it looks like a C condition.
> 
> > +         */
> > +        if (virAsprintf(&group->unified.placement, "%s%s%s",
> > +                        parent->unified.placement,
> > +                        (STREQ(parent->unified.placement, "/") ||
> > +                         STREQ(path, "") ? "" : "/"),
> > +                        path) < 0)
> 
> Maybe if you got rid of the ternary operator it would be more readable.
> But now that I finally understood this, I don't care that much :-)

Yes, this bit is kind of weird and should be improved, it's basically
copy&paste from cgroupv1 backend code.  As a followup we can export it
into a function and reuse it in both backends.

> 
> > +            return -1;
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> > +
> >  virCgroupBackend virCgroupV2Backend = {
> >      .type = VIR_CGROUP_BACKEND_TYPE_V2,
> >  
> >      .available = virCgroupV2Available,
> >      .validateMachineGroup = virCgroupV2ValidateMachineGroup,
> >      .copyMounts = virCgroupV2CopyMounts,
> > +    .copyPlacement = virCgroupV2CopyPlacement,
> >  };
> >  
> >  
> > 
> 
> ACK
> 
> Michal
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