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[188.28.125.106]) by smtp.gmail.com with ESMTPSA id a4-20020adff7c4000000b0021033caa332sm12353064wrq.42.2022.06.14.07.37.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Jun 2022 07:37:57 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com Subject: [PATCH for-next v2 16/25] io_uring: pass poll_find lock back Date: Tue, 14 Jun 2022 15:37:06 +0100 Message-Id: X-Mailer: git-send-email 2.36.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Instead of using implicit knowledge of what is locked or not after io_poll_find() and co returns, pass back a pointer to the locked bucket if any. If set the user must to unlock the spinlock. Signed-off-by: Pavel Begunkov --- io_uring/poll.c | 46 ++++++++++++++++++++++++++-------------------- 1 file changed, 26 insertions(+), 20 deletions(-) diff --git a/io_uring/poll.c b/io_uring/poll.c index 7f6b16f687b0..7fc4aafcca95 100644 --- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -559,12 +559,15 @@ __cold bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk, } static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, bool poll_only, - struct io_cancel_data *cd) + struct io_cancel_data *cd, + struct io_hash_bucket **out_bucket) { struct io_kiocb *req; u32 index = hash_long(cd->data, ctx->cancel_hash_bits); struct io_hash_bucket *hb = &ctx->cancel_hash[index]; + *out_bucket = NULL; + spin_lock(&hb->lock); hlist_for_each_entry(req, &hb->list, hash_node) { if (cd->data != req->cqe.user_data) @@ -576,6 +579,7 @@ static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, bool poll_only, continue; req->work.cancel_seq = cd->seq; } + *out_bucket = hb; return req; } spin_unlock(&hb->lock); @@ -583,11 +587,14 @@ static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, bool poll_only, } static struct io_kiocb *io_poll_file_find(struct io_ring_ctx *ctx, - struct io_cancel_data *cd) + struct io_cancel_data *cd, + struct io_hash_bucket **out_bucket) { struct io_kiocb *req; int i; + *out_bucket = NULL; + for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) { struct io_hash_bucket *hb = &ctx->cancel_hash[i]; @@ -599,6 +606,7 @@ static struct io_kiocb *io_poll_file_find(struct io_ring_ctx *ctx, if (cd->seq == req->work.cancel_seq) continue; req->work.cancel_seq = cd->seq; + *out_bucket = hb; return req; } spin_unlock(&hb->lock); @@ -617,23 +625,19 @@ static bool io_poll_disarm(struct io_kiocb *req) int io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd) { + struct io_hash_bucket *bucket; struct io_kiocb *req; - u32 index; - spinlock_t *lock; if (cd->flags & (IORING_ASYNC_CANCEL_FD|IORING_ASYNC_CANCEL_ANY)) - req = io_poll_file_find(ctx, cd); + req = io_poll_file_find(ctx, cd, &bucket); else - req = io_poll_find(ctx, false, cd); - if (!req) { - return -ENOENT; - } else { - index = hash_long(req->cqe.user_data, ctx->cancel_hash_bits); - lock = &ctx->cancel_hash[index].lock; - } - io_poll_cancel_req(req); - spin_unlock(lock); - return 0; + req = io_poll_find(ctx, false, cd, &bucket); + + if (req) + io_poll_cancel_req(req); + if (bucket) + spin_unlock(&bucket->lock); + return req ? 0 : -ENOENT; } static __poll_t io_poll_parse_events(const struct io_uring_sqe *sqe, @@ -726,19 +730,21 @@ int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags) struct io_poll_update *poll_update = io_kiocb_to_cmd(req); struct io_cancel_data cd = { .data = poll_update->old_user_data, }; struct io_ring_ctx *ctx = req->ctx; - u32 index = hash_long(cd.data, ctx->cancel_hash_bits); - spinlock_t *lock = &ctx->cancel_hash[index].lock; + struct io_hash_bucket *bucket; struct io_kiocb *preq; int ret2, ret = 0; bool locked; - preq = io_poll_find(ctx, true, &cd); + preq = io_poll_find(ctx, true, &cd, &bucket); + if (preq) + ret2 = io_poll_disarm(preq); + if (bucket) + spin_unlock(&bucket->lock); + if (!preq) { ret = -ENOENT; goto out; } - ret2 = io_poll_disarm(preq); - spin_unlock(lock); if (!ret2) { ret = -EALREADY; goto out;