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With that the caller is allowed but not always required to hold the completion lock while overflowing. Signed-off-by: Pavel Begunkov --- include/linux/io_uring_types.h | 1 + io_uring/io_uring.c | 32 ++++++++++++-------------------- 2 files changed, 13 insertions(+), 20 deletions(-) diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index 00dbd7cd0e7d..e11ab9d19877 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -370,6 +370,7 @@ struct io_ring_ctx { spinlock_t completion_lock; struct list_head cq_overflow_list; + spinlock_t overflow_lock; struct hlist_head waitid_list; diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index a2a4e1319033..86b39a01a136 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -350,6 +350,7 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) init_waitqueue_head(&ctx->cq_wait); init_waitqueue_head(&ctx->poll_wq); spin_lock_init(&ctx->completion_lock); + spin_lock_init(&ctx->overflow_lock); raw_spin_lock_init(&ctx->timeout_lock); INIT_WQ_LIST(&ctx->iopoll_list); INIT_LIST_HEAD(&ctx->defer_list); @@ -624,6 +625,8 @@ static bool io_flush_overflow_list(struct io_ring_ctx *ctx, bool dying) if (ctx->flags & IORING_SETUP_CQE32) cqe_size <<= 1; + guard(spinlock)(&ctx->overflow_lock); + while (!list_empty(&ctx->cq_overflow_list)) { struct io_uring_cqe *cqe; struct io_overflow_cqe *ocqe; @@ -733,8 +736,6 @@ static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data, size_t ocq_size = sizeof(struct io_overflow_cqe); bool is_cqe32 = (ctx->flags & IORING_SETUP_CQE32); - lockdep_assert_held(&ctx->completion_lock); - if (is_cqe32) ocq_size += sizeof(struct io_uring_cqe); @@ -750,6 +751,9 @@ static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data, } trace_io_uring_cqe_overflow(ctx, user_data, res, cflags, ocqe); + + guard(spinlock)(&ctx->overflow_lock); + if (!ocqe) { struct io_rings *r = ctx->rings; @@ -849,11 +853,9 @@ void io_add_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags) lockdep_assert_held(&ctx->uring_lock); lockdep_assert(ctx->lockless_cq); - if (!io_fill_cqe_aux(ctx, user_data, res, cflags)) { - spin_lock(&ctx->completion_lock); + if (!io_fill_cqe_aux(ctx, user_data, res, cflags)) io_cqring_event_overflow(ctx, user_data, res, cflags, 0, 0); - spin_unlock(&ctx->completion_lock); - } + ctx->submit_state.cq_flush = true; } @@ -1442,20 +1444,10 @@ void __io_submit_flush_completions(struct io_ring_ctx *ctx) */ if (!(req->flags & (REQ_F_CQE_SKIP | REQ_F_REISSUE)) && unlikely(!io_fill_cqe_req(ctx, req))) { - if (ctx->lockless_cq) { - spin_lock(&ctx->completion_lock); - io_cqring_event_overflow(req->ctx, req->cqe.user_data, - req->cqe.res, req->cqe.flags, - req->big_cqe.extra1, - req->big_cqe.extra2); - spin_unlock(&ctx->completion_lock); - } else { - io_cqring_event_overflow(req->ctx, req->cqe.user_data, - req->cqe.res, req->cqe.flags, - req->big_cqe.extra1, - req->big_cqe.extra2); - } - + io_cqring_event_overflow(req->ctx, req->cqe.user_data, + req->cqe.res, req->cqe.flags, + req->big_cqe.extra1, + req->big_cqe.extra2); memset(&req->big_cqe, 0, sizeof(req->big_cqe)); } } -- 2.49.0