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af_unix: Remove io_uring code for GC.

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Since commit 705318a99a ("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 6e5e6d2749 ("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 0091bfc817
("io_uring/af_unix: defer registered files gc to io_uring release")
and commit 1036908045 ("net: reclaim skb->scm_io_uring bit").

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20240129190435.57228-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Kuniyuki Iwashima 2024-01-29 11:04:34 -08:00 committed by Jakub Kicinski
parent d0f6dc2634
commit 11498715f2
3 changed files with 2 additions and 30 deletions
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1
include/net/af_unix.h
View File

@ -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);

25
net/unix/garbage.c
View File

@ -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));

6
net/unix/scm.c
View File

@ -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);