[libvirt PATCH v6 12/30] nodedev: add helper functions to remove node devices

[Erik Skultety]

On Fri, Mar 26, 2021 at 11:48:08AM -0500, Jonathon Jongsma wrote:
> When a mediated device is stopped or undefined by an application outside
> of libvirt, we need to remove it from our list of node devices within
> libvirt. This patch introduces virNodeDeviceObjListRemoveLocked() and
> virNodeDeviceObjListForEachRemove() (which are analogous to other types
> of object lists in libvirt) to facilitate that. They will be used in
> coming commits.
> 
> Signed-off-by: Jonathon Jongsma <jjongsma at redhat.com>
> ---
>  src/conf/virnodedeviceobj.c | 58 ++++++++++++++++++++++++++++++++++---
>  src/conf/virnodedeviceobj.h | 11 +++++++
>  src/libvirt_private.syms    |  2 ++
>  3 files changed, 67 insertions(+), 4 deletions(-)
> 
> diff --git a/src/conf/virnodedeviceobj.c b/src/conf/virnodedeviceobj.c
> index ce84e4d8c1..97e7d7ab11 100644
> --- a/src/conf/virnodedeviceobj.c
> +++ b/src/conf/virnodedeviceobj.c
> @@ -507,23 +507,29 @@ void
>  virNodeDeviceObjListRemove(virNodeDeviceObjListPtr devs,
>                             virNodeDeviceObjPtr obj)
>  {
> -    virNodeDeviceDefPtr def;
> -
>      if (!obj)
>          return;
> -    def = obj->def;
>  
>      virObjectRef(obj);
>      virObjectUnlock(obj);
>      virObjectRWLockWrite(devs);
>      virObjectLock(obj);
> -    virHashRemoveEntry(devs->objs, def->name);
> +    virNodeDeviceObjListRemoveLocked(devs, obj);
>      virObjectUnlock(obj);
>      virObjectUnref(obj);
>      virObjectRWUnlock(devs);
>  }
>  
>  
> +/* The caller must hold lock on 'devs' */
> +void
> +virNodeDeviceObjListRemoveLocked(virNodeDeviceObjList *devs,
> +                                 virNodeDeviceObj *dev)
> +{
> +    virHashRemoveEntry(devs->objs, dev->def->name);
> +}
> +
> +
>  /*
>   * Return the NPIV dev's parent device name
>   */
> @@ -1019,3 +1025,47 @@ virNodeDeviceObjSetPersistent(virNodeDeviceObj *obj,
>  {
>      obj->persistent = persistent;
>  }
> +
> +
> +struct virNodeDeviceObjListRemoveData

Looking at other libvirt code, the precedent seems to be for this be named
xyzListRemoveHelperData

> +{
> +    virNodeDeviceObjListRemoveIter iter;

and ^this one should IMO be named xyzListRemoveIterator callback;

> +    void *opaque;
> +};
> +
> +static int virNodeDeviceObjListRemoveCb(void *key G_GNUC_UNUSED,
> +                                        void *value,
> +                                        void *opaque)
> +{
> +    struct virNodeDeviceObjListRemoveData *data = opaque;
> +
> +    return data->iter(value, data->opaque);

data->callback

> +}
> +
> +
> +/**
> + * virNodeDeviceObjListForEachRemove
> + * @devs: Pointer to object list
> + * @iter: function to call for each device object

s/iter/callback (it sounds odd that we're iterating over something and call
another iterator over each item --> hence "callback")

> + * @opaque: Opaque data to use as argument to helper
> + *
> + * For each object in @devs, call the @iter helper using @opaque as
> + * an argument. If @iter returns true, that item will be removed from the
> + * object list.
> + */
> +void
> +virNodeDeviceObjListForEachRemove(virNodeDeviceObjList *devs,
> +                                  virNodeDeviceObjListRemoveIter iter,
> +                                  void *opaque)
> +{
> +    struct virNodeDeviceObjListRemoveData data = {
> +        .iter = iter,
> +        .opaque = opaque
> +    };
> +
> +    virObjectRWLockWrite(devs);
> +    g_hash_table_foreach_remove(devs->objs,
> +                                virNodeDeviceObjListRemoveCb,

xyzListRemoveHelper...


Reviewed-by: Erik Skultety <eskultet at redhat.com>