[CRIU] [PATCH] Add checkpoint/restore for /proc/pid/exe symlink

[Stanislav Kinsbursky]

06.02.2012 19:41, Cyrill Gorcunov пишет:
> This patch adds ability to checkpoint/restore
> /proc/pid/exe symlink, so if a process we've just
> checkpointed has been say /path/to/exe, then at restore
> time we bring this path back.
>
> A few notes
>
>   - If the file which symlink we're about to restore
>     has been deleted after checkpoint procedure and
>     no longer exist -- we print error message but do
>     not interrupt restore procedure because it's not
>     that critical
>

1 of all: sorry for probably dummy questions.

We do not migrate unlinked files yet? Or we don't even check, that this file is 
unlinked?

>   - Also there some restiction from kernel side: if
>     existing /proc/pid/exe already mapped more than
>     once, the kernel will refuse to change the symlink,
>     so we need to restore it lately when mmaps of crtools
>     itself already unmapped (ie via late call in
>     restorer.c).

Why do we need change this symlink at all?

>
> In any case -- we don't treat inability to restore
> /proc/pid/exe symlink as a critical error.
>

Is this proc symlink tied with exe vma restoration? IOW, we have to restore vma 
for task binary, don't we? And in this case, what is the problem to restore 
/proc/pid/exe always?


-- 
Best regards,
Stanislav Kinsbursky