On 21.01, Thomas Graf wrote:

On 01/21/15 at 10:40am, Patrick McHardy wrote:

quoted

On the danger of repeating myself, every (converted) user requires
that we at least keep the existing semantics since it is exposed to
userspace. My opinion is that NLM_F_DUMP_INTR is fine if userspace
indicates support, but without that, we have to take care of that
in the kernel.

Absolutely agreed. I think this is an excellent low cost path for
future users where dumps are rare.

quoted

An automatic restart handles this well. Userspace always had to
expect duplicates.

Maybe I don't understand the restart yet. How do you restart if the
dump was already started and the user has read part of the dump?

You use the mutex to prevent concurrent resizes and dumps, for dumps
that have left the kernel you simply reset the iterator state after
a resize operation.