From 10369080454d87ee5b2db211ce947cb3118f0e13 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 7 Mar 2023 14:59:59 +0000 Subject: [PATCH] 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 Cc: Pavel Begunkov Cc: Thadeu Lima de Souza Cascardo Cc: Jens Axboe Reviewed-by: Jens Axboe Reviewed-by: Pavel Begunkov Signed-off-by: David S. Miller --- include/linux/skbuff.h | 2 -- include/net/af_unix.h | 1 + io_uring/rsrc.c | 3 +-- net/unix/garbage.c | 2 +- net/unix/scm.c | 6 ++++++ 5 files changed, 9 insertions(+), 5 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index ff7ad331fb82..fe661011644b 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -810,7 +810,6 @@ typedef unsigned char *sk_buff_data_t; * @csum_level: indicates the number of consecutive checksums found in * the packet minus one that have been verified as * CHECKSUM_UNNECESSARY (max 3) - * @scm_io_uring: SKB holds io_uring registered files * @dst_pending_confirm: need to confirm neighbour * @decrypted: Decrypted SKB * @slow_gro: state present at GRO time, slower prepare step required @@ -989,7 +988,6 @@ struct sk_buff { #endif __u8 slow_gro:1; __u8 csum_not_inet:1; - __u8 scm_io_uring:1; #ifdef CONFIG_NET_SCHED __u16 tc_index; /* traffic control index */ diff --git a/include/net/af_unix.h b/include/net/af_unix.h index 480fa579787e..45ebde587138 100644 --- a/include/net/af_unix.h +++ b/include/net/af_unix.h @@ -11,6 +11,7 @@ void unix_inflight(struct user_struct *user, struct file *fp); void unix_notinflight(struct user_struct *user, struct file *fp); void unix_destruct_scm(struct sk_buff *skb); +void io_uring_destruct_scm(struct sk_buff *skb); void unix_gc(void); void wait_for_unix_gc(void); struct sock *unix_get_socket(struct file *filp); diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c index a59fc02de598..27ceda3b50cf 100644 --- a/io_uring/rsrc.c +++ b/io_uring/rsrc.c @@ -867,8 +867,7 @@ int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file) UNIXCB(skb).fp = fpl; skb->sk = sk; - skb->scm_io_uring = 1; - skb->destructor = unix_destruct_scm; + skb->destructor = io_uring_destruct_scm; refcount_add(skb->truesize, &sk->sk_wmem_alloc); } diff --git a/net/unix/garbage.c b/net/unix/garbage.c index dc2763540393..2405f0f9af31 100644 --- a/net/unix/garbage.c +++ b/net/unix/garbage.c @@ -305,7 +305,7 @@ void unix_gc(void) * release.path eventually putting registered files. */ skb_queue_walk_safe(&hitlist, skb, next_skb) { - if (skb->scm_io_uring) { + if (skb->destructor == io_uring_destruct_scm) { __skb_unlink(skb, &hitlist); skb_queue_tail(&skb->sk->sk_receive_queue, skb); } 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); -- 2.11.0