Re: [PATCH 2/3] netns: add netns_evict into netns_operations

From: Wenbin Zeng <redacted>
Date: Wed,  1 May 2019 14:42:24 +0800

The newly added netns_evict() shall be called when the netns inode being
evicted. It provides another path to release netns refcounts, previously
netns_put() is the only choice, but it is not able to release all netns
refcount, for example, a rpc client holds two netns refcounts, these
refcounts are supposed to be released when the rpc client is freed, but
the code to free rpc client is normally triggered by put() callback only
when netns refcount gets to 0, specifically:
    refcount=0 -> cleanup_net() -> ops_exit_list -> free rpc client
But netns refcount will never get to 0 before rpc client gets freed, to
break the deadlock, the code to free rpc client can be put into the newly
added netns_evict.

Signed-off-by: Wenbin Zeng <redacted>

Acked-by: David S. Miller <davem@davemloft.net>