netdev - Re: [PATCH net v2 1/2] Revert "net: macsec: use skb_ensure_writable_head

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Date: Tue, 23 Jan 2024 10:19:21 +0100
From: Paolo Abeni <pabeni@...hat.com>
To: Sabrina Dubroca <sd@...asysnail.net>, Rahul Rameshbabu
	 <rrameshbabu@...dia.com>
Cc: netdev@...r.kernel.org, Gal Pressman <gal@...dia.com>, Jakub Kicinski
	 <kuba@...nel.org>, Eric Dumazet <edumazet@...gle.com>, Radu Pirea
	 <radu-nicolae.pirea@....nxp.com>, "David S . Miller" <davem@...emloft.net>
Subject: Re: [PATCH net v2 1/2] Revert "net: macsec: use
 skb_ensure_writable_head_tail to expand the skb"

On Sun, 2024-01-21 at 10:32 +0100, Sabrina Dubroca wrote:
> 2024-01-18, 11:18:06 -0800, Rahul Rameshbabu wrote:
> > This reverts commit b34ab3527b9622ca4910df24ff5beed5aa66c6b5.
> > 
> > Using skb_ensure_writable_head_tail without a call to skb_unshare causes
> > the MACsec stack to operate on the original skb rather than a copy in the
> > macsec_encrypt path. This causes the buffer to be exceeded in space, and
> > leads to warnings generated by skb_put operations. Opting to revert this
> > change since skb_copy_expand is more efficient than
> > skb_ensure_writable_head_tail followed by a call to skb_unshare.
> 
> Paolo, are you ok with this commit message? I agree it's a bit
> confusing but I can't think of anything clearer :(

Yes, I re-read the relevant code and now the fix is clearer to me,
thanks!

I understand the intention is to drop patch 2/2.

Could you please confirm that? If so, I can apply 1/2 without a repost.

Thanks,

Paolo