[CRIU] [PATCH v3 00/16] AutoFS mounts migration support

[Pavel Emelyanov]

On 12/14/2015 07:25 PM, Stanislav Kinsburskiy wrote:
> So, let me try summarize all we have discussed here so far:
> 
> 1) Helpers: add_to_string_vargs and and construct string. You don't like 
> them? They are more efficient, then add_options and friend, BTW. And 
> fully generic.
> 2) Autofs migration data have to be represented by optional autofs 
> structure in mount protobuf format.

Looks like yes.

> 3) Are we trying to preserve original pipe write fd on restore? If yes, 
> then we need "used" list.

Kernel remembers this fd and shows on in options, so yes, this number
must be preserved.

> 4) Regardless of presence or absence of opened write end, some routing 
> to search for file descriptor list entry is required: either to masrk 
> write end or to clone read end.

Probably. I saw it like -- you know the pipe_id that sits in the kernel,
so on restore you just 'create' this pipe_info and add respective fd entry
to the proper task.

> 5) "Clone file descriptor list entry" helper is required to construct 
> write end is absent.

Probably yes.

> 6) Which way should autofs restore follow: use some artificial objects, 
> handled after all files are opened or callbacks between autofs and 
> pipes? In case of the latter, some callback have to be put on pipe_entry 
> structure, so it can be called in new post_open() for pipes.

>From my perspective taking a task that should restore write end and
adding to its rst_info a file desc entry which refers to the needed 
pipe is the easiest way to go.

> I hope, I didn't miss anything.
> Please, review and comment.

-- Pavel