Re: [PATCH v4 1/5] xen/hypfs: support dynamic hypfs nodes

[Jan Beulich <jbeulich@xxxxxxxx>]

On 18.01.2021 12:55, Juergen Gross wrote:
> Add a HYPFS_VARDIR_INIT() macro for initializing such a directory
> statically, taking a struct hypfs_funcs pointer as parameter additional
> to those of HYPFS_DIR_INIT().
> 
> Modify HYPFS_VARSIZE_INIT() to take the function vector pointer as an
> additional parameter as this will be needed for dynamical entries.
> 
> For being able to let the generic hypfs coding continue to work on
> normal struct hypfs_entry entities even for dynamical nodes add some
> infrastructure for allocating a working area for the current hypfs
> request in order to store needed information for traversing the tree.
> This area is anchored in a percpu pointer and can be retrieved by any
> level of the dynamic entries. The normal way to handle allocation and
> freeing is to allocate the data in the enter() callback of a node and
> to free it in the related exit() callback.
> 
> Add a hypfs_add_dyndir() function for adding a dynamic directory
> template to the tree, which is needed for having the correct reference
> to its position in hypfs.
> 
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>