Re: [Xen-devel] [PATCH 2/3] docs: add DIRECTORY_PART specification do xenstore protocol doc

[Ian Jackson <ian.jackson@xxxxxxxxxxxxx>]

Juergen Gross writes ("[PATCH 2/3] docs: add DIRECTORY_PART specification do 
xenstore protocol doc"):
> DIRECTORY_PART was missing in docs/misc/xenstore.txt. Add it.
...
> +DIRECTORY_PART               <path>|<offset>         
> <gencnt>|<child-leaf-name>|*
> +     Same as DIRECTORY, but to be used for children lists longer than
> +     XENSTORE_PAYLOAD_MAX. Input are <path> and the byte offset into
> +     the list of children to return. Return values are the generation
> +     count <gencnt> of the node (to be used to ensure the node hasn't
> +     changed between two reads: <gencnt> being the same for multiple
> +     reads guarantees the node hasn't changed) and the list of children
> +     starting at the specified <offset> of the complete list.

The "generation count" is not defined anywhere else in this protocol
spec, so shouldn't be referred to here without definition.  We should
explicitly state whether using a transaction is sufficient to ensure
that this check will never fail.

Taken together, I think the right approach is to specify a method to
use this and to say that if a different method is used, the results
are not reliable.

Ian.

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