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[188.28.229.101]) by smtp.gmail.com with ESMTPSA id i18-20020a5d5232000000b0028e55b44a99sm14456076wra.17.2023.01.03.17.36.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Jan 2023 17:36:21 -0800 (PST) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com Subject: [RFC 1/1] io_uring: lockdep annotate CQ locking Date: Wed, 4 Jan 2023 01:34:57 +0000 Message-Id: X-Mailer: git-send-email 2.38.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Locking around CQE posting is complex and depends on options the ring is created with, add more thorough lockdep annotations checking all invariants. Signed-off-by: Pavel Begunkov --- io_uring/io_uring.c | 5 ++--- io_uring/io_uring.h | 15 +++++++++++++++ 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 6bed44855679..472574192dd6 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -731,6 +731,8 @@ 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); @@ -820,9 +822,6 @@ static bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data, s32 res, { struct io_uring_cqe *cqe; - if (!ctx->task_complete) - lockdep_assert_held(&ctx->completion_lock); - ctx->cq_extra++; /* diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h index e9f0d41ebb99..ab4b2a1c3b7e 100644 --- a/io_uring/io_uring.h +++ b/io_uring/io_uring.h @@ -79,6 +79,19 @@ bool __io_alloc_req_refill(struct io_ring_ctx *ctx); bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task, bool cancel_all); +#define io_lockdep_assert_cq_locked(ctx) \ + do { \ + if (ctx->flags & IORING_SETUP_IOPOLL) { \ + lockdep_assert_held(&ctx->uring_lock); \ + } else if (!ctx->task_complete) { \ + lockdep_assert_held(&ctx->completion_lock); \ + } else if (ctx->submitter_task->flags & PF_EXITING) { \ + lockdep_assert(current_work()); \ + } else { \ + lockdep_assert(current == ctx->submitter_task); \ + } \ + } while (0) + static inline void io_req_task_work_add(struct io_kiocb *req) { __io_req_task_work_add(req, true); @@ -92,6 +105,8 @@ void io_cq_unlock_post(struct io_ring_ctx *ctx); static inline struct io_uring_cqe *io_get_cqe_overflow(struct io_ring_ctx *ctx, bool overflow) { + io_lockdep_assert_cq_locked(ctx); + if (likely(ctx->cqe_cached < ctx->cqe_sentinel)) { struct io_uring_cqe *cqe = ctx->cqe_cached; -- 2.38.1