net: reclaim skb->scm_io_uring bit

Commit 0091bfc81741 ("io_uring/af_unix: defer registered
files gc to io_uring release") added one bit to struct sk_buff.

This structure is critical for networking, and we try very hard
to not add bloat on it, unless absolutely required.

For instance, we can use a specific destructor as a wrapper
around unix_destruct_scm(), to identify skbs that unix_gc()
has to special case.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/net/unix/scm.c b/net/unix/scm.c
index aa27a02478dc..f9152881d77f 100644
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -152,3 +152,9 @@ void unix_destruct_scm(struct sk_buff *skb)
 	sock_wfree(skb);
 }
 EXPORT_SYMBOL(unix_destruct_scm);
+
+void io_uring_destruct_scm(struct sk_buff *skb)
+{
+	unix_destruct_scm(skb);
+}
+EXPORT_SYMBOL(io_uring_destruct_scm);