From 39c9676f789eb71ce1005a22eebe2be80a00de6a Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Thu, 13 Nov 2025 10:46:14 +0000 Subject: [PATCH] io_uring/zcrx: count zcrx users zcrx tries to detach ifq / terminate page pools when the io_uring ctx owning it is being destroyed. There will be multiple io_uring instances attached to it in the future, so add a separate counter to track the users. Note, refs can't be reused for this purpose as it only used to prevent zcrx and rings destruction, and also used by page pools to keep it alive. Signed-off-by: David Wei Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- io_uring/zcrx.c | 7 +++++-- io_uring/zcrx.h | 2 ++ 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c index 08c103af69bc..2335f140ff19 100644 --- a/io_uring/zcrx.c +++ b/io_uring/zcrx.c @@ -482,6 +482,7 @@ static struct io_zcrx_ifq *io_zcrx_ifq_alloc(struct io_ring_ctx *ctx) spin_lock_init(&ifq->rq_lock); mutex_init(&ifq->pp_lock); refcount_set(&ifq->refs, 1); + refcount_set(&ifq->user_refs, 1); return ifq; } @@ -742,8 +743,10 @@ void io_unregister_zcrx_ifqs(struct io_ring_ctx *ctx) if (!ifq) break; - io_close_queue(ifq); - io_zcrx_scrub(ifq); + if (refcount_dec_and_test(&ifq->user_refs)) { + io_close_queue(ifq); + io_zcrx_scrub(ifq); + } io_put_zcrx_ifq(ifq); } diff --git a/io_uring/zcrx.h b/io_uring/zcrx.h index f29edc22c91f..32ab95b2cb81 100644 --- a/io_uring/zcrx.h +++ b/io_uring/zcrx.h @@ -55,6 +55,8 @@ struct io_zcrx_ifq { struct net_device *netdev; netdevice_tracker netdev_tracker; refcount_t refs; + /* counts userspace facing users like io_uring */ + refcount_t user_refs; /* * Page pool and net configuration lock, can be taken deeper in the