Commit 11498715 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
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af_unix: Remove io_uring code for GC. 



Since commit 705318a9 ("io_uring/af_unix: disable sending
io_uring over sockets"), io_uring's unix socket cannot be passed
via SCM_RIGHTS, so it does not contribute to cyclic reference and
no longer be candidate for garbage collection.

Also, commit 6e5e6d27 ("io_uring: drop any code related to
SCM_RIGHTS") cleaned up SCM_RIGHTS code in io_uring.

Let's do it in AF_UNIX as well by reverting commit 0091bfc8
("io_uring/af_unix: defer registered files gc to io_uring release")
and commit 10369080 ("net: reclaim skb->scm_io_uring bit").

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: default avatarJens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20240129190435.57228-3-kuniyu@amazon.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent d0f6dc26

include/net/af_unix.h

+0 −1
Original line number Diff line number Diff line
@@ -20,7 +20,6 @@ static inline struct unix_sock *unix_get_socket(struct file *filp) 
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(struct scm_fp_list *fpl);

struct sock *unix_peer_get(struct sock *sk);

net/unix/garbage.c

+2 −23
Original line number Diff line number Diff line
@@ -184,12 +184,10 @@ static bool gc_in_progress; 


static void __unix_gc(struct work_struct *work)

{

	struct sk_buff *next_skb, *skb;

	struct unix_sock *u;

	struct unix_sock *next;

	struct sk_buff_head hitlist;

	struct list_head cursor;

	struct unix_sock *u, *next;

	LIST_HEAD(not_cycle_list);

	struct list_head cursor;



	spin_lock(&unix_gc_lock);
@@ -269,30 +267,11 @@ static void __unix_gc(struct work_struct *work) 


	spin_unlock(&unix_gc_lock);



	/* We need io_uring to clean its registered files, ignore all io_uring

	 * originated skbs. It's fine as io_uring doesn't keep references to

	 * other io_uring instances and so killing all other files in the cycle

	 * will put all io_uring references forcing it to go through normal

	 * release.path eventually putting registered files.

	 */

	skb_queue_walk_safe(&hitlist, skb, next_skb) {

		if (skb->destructor == io_uring_destruct_scm) {

			__skb_unlink(skb, &hitlist);

			skb_queue_tail(&skb->sk->sk_receive_queue, skb);

		}

	}



	/* Here we are. Hitlist is filled. Die. */

	__skb_queue_purge(&hitlist);



	spin_lock(&unix_gc_lock);



	/* There could be io_uring registered files, just push them back to

	 * the inflight list

	 */

	list_for_each_entry_safe(u, next, &gc_candidates, link)

		list_move_tail(&u->link, &gc_inflight_list);



	/* All candidates should have been detached by now. */

	WARN_ON_ONCE(!list_empty(&gc_candidates));

net/unix/scm.c

+0 −6
Original line number Diff line number Diff line
@@ -148,9 +148,3 @@ 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);