Re: [PATCH net] tcp: fix page frag corruption on page fault

On Fri, Nov 26, 2021 at 7:27 AM Eric Dumazet [off-list ref] wrote:

We need to find one flag that can ask  gfpflags_normal_context() to
return false for this case.

Or if too difficult, stop only using sk->sk_allocation to decide
between the per-thread frag, or the per socket one.

I presume there are few active CIFS sockets on a host. They should use
a per socket sk_frag.

A pure networking change could be to use a new MSG_  flag to force sendmsg()
to use the sk->sk_frag, but that would add yet another test in TCP fast path.

About gfpflags_normal_context being used by dlm : we can simply add our own
helper with a new name describing that we want:

Both being in process context, and not from page fault handler .