From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9F12C43603 for ; Tue, 10 Dec 2019 15:57:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95A33207FF for ; Tue, 10 Dec 2019 15:57:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="KRJCkv4v" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727178AbfLJP5u (ORCPT ); Tue, 10 Dec 2019 10:57:50 -0500 Received: from mail-io1-f65.google.com ([209.85.166.65]:40023 "EHLO mail-io1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727223AbfLJP5u (ORCPT ); Tue, 10 Dec 2019 10:57:50 -0500 Received: by mail-io1-f65.google.com with SMTP id x1so19311013iop.7 for ; Tue, 10 Dec 2019 07:57:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=sCwLcLXQDmwoHa3uJcFN6zc4t5M1kqNoojcyizO0Yxo=; b=KRJCkv4vJv/P66/BIfc6th5esCC5dM6jgZJCwJo5wWx5V82CyEUDRLp5TkHe9HmV/m X5VE+Hj0nvdFJyarwD0AejRpx3+8utfdo+H3610q/Sbh0JLATsB0Qm8bOM0IajJML0ZN Nrj2FG7AqIlxYfbhjoD5UEKYL0a/NFkFHoaH81/FMOsqOdCKj6NE++0N69F89TWYGZfa ZH2df0ajGioxsIVb9nw62y/hDUuNVjjpz+DsyJM+URmnXMx4xoWa/kIski3N9IR0ZVih +GH9r9YeYW757Ty7btMIgCiqeCvcLFGet4cLLxLnBKOKu2+YdSfrgXWpenwVhQxDYvun NV9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=sCwLcLXQDmwoHa3uJcFN6zc4t5M1kqNoojcyizO0Yxo=; b=h8khD8rzXXEyTVTwrHvKJspLCbKh+7zydOsEHygpGmBVKqAgjNUgf5VNiC9btNwlV2 vFuiSgAi7pi8X04DehkRqDsbl0SIjn9JtBjaJ5MEzcBrF/0q4RFr02uLfi/eqYAgR+/+ 6TAeBP0G2M92ZltOUPKUBAD023Q5tWIL9vrGvJqbMo4clw+k2H5Gbx0BpZk6pKozG4kf 8mN4h1opIDdtHv/FcQS0oV/qOaIVb8Kw8dc5VgPD5of872Ti/A+mk1so8sURhUzvzSMs kfRw9/CAdexs4BK5Kw3FdNOw0vPNaZyMzxhbOcy0ADAqZLIwNgL00FZ0gFIw6VCV0eYQ QVdQ== X-Gm-Message-State: APjAAAWswXZD5l4W/ggdVBlQ/ycnBVq/saWBiLozRROQces34wqXX3W+ Wls+TGx9aVRqIhgVKo3oFPICa03z7wEikw== X-Google-Smtp-Source: APXvYqy9miDFPXxUaElRKRoerNLROzr2xgF8IELPq1+xq0Dt1sV8QgZR1WN4mFBdw17pUfS+4SM/fw== X-Received: by 2002:a02:7301:: with SMTP id y1mr26722201jab.52.1575993467684; Tue, 10 Dec 2019 07:57:47 -0800 (PST) Received: from x1.thefacebook.com ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id w6sm770953ioa.16.2019.12.10.07.57.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 Dec 2019 07:57:46 -0800 (PST) From: Jens Axboe To: io-uring@vger.kernel.org Cc: Jens Axboe , stable@vger.kernel.org, Pavel Begunkov , =?UTF-8?q?=E6=9D=8E=E9=80=9A=E6=B4=B2?= Subject: [PATCH 01/11] io_uring: allow unbreakable links Date: Tue, 10 Dec 2019 08:57:32 -0700 Message-Id: <20191210155742.5844-2-axboe@kernel.dk> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191210155742.5844-1-axboe@kernel.dk> References: <20191210155742.5844-1-axboe@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Some commands will invariably end in a failure in the sense that the completion result will be less than zero. One such example is timeouts that don't have a completion count set, they will always complete with -ETIME unless cancelled. For linked commands, we sever links and fail the rest of the chain if the result is less than zero. Since we have commands where we know that will happen, add IOSQE_IO_HARDLINK as a stronger link that doesn't sever regardless of the completion result. Note that the link will still sever if we fail submitting the parent request, hard links are only resilient in the presence of completion results for requests that did submit correctly. Cc: stable@vger.kernel.org # v5.4 Cc: Pavel Begunkov Reported-by: 李通洲 Signed-off-by: Jens Axboe --- fs/io_uring.c | 96 ++++++++++++++++++++--------------- include/uapi/linux/io_uring.h | 1 + 2 files changed, 56 insertions(+), 41 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 405be10da73d..4cda61fe67da 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -377,6 +377,7 @@ struct io_kiocb { #define REQ_F_TIMEOUT_NOSEQ 8192 /* no timeout sequence */ #define REQ_F_INFLIGHT 16384 /* on inflight list */ #define REQ_F_COMP_LOCKED 32768 /* completion under lock */ +#define REQ_F_HARDLINK 65536 /* doesn't sever on completion < 0 */ u64 user_data; u32 result; u32 sequence; @@ -1292,6 +1293,12 @@ static void kiocb_end_write(struct io_kiocb *req) file_end_write(req->file); } +static inline void req_set_fail_links(struct io_kiocb *req) +{ + if ((req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) == REQ_F_LINK) + req->flags |= REQ_F_FAIL_LINK; +} + static void io_complete_rw_common(struct kiocb *kiocb, long res) { struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw); @@ -1299,8 +1306,8 @@ static void io_complete_rw_common(struct kiocb *kiocb, long res) if (kiocb->ki_flags & IOCB_WRITE) kiocb_end_write(req); - if ((req->flags & REQ_F_LINK) && res != req->result) - req->flags |= REQ_F_FAIL_LINK; + if (res != req->result) + req_set_fail_links(req); io_cqring_add_event(req, res); } @@ -1330,8 +1337,8 @@ static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2) if (kiocb->ki_flags & IOCB_WRITE) kiocb_end_write(req); - if ((req->flags & REQ_F_LINK) && res != req->result) - req->flags |= REQ_F_FAIL_LINK; + if (res != req->result) + req_set_fail_links(req); req->result = res; if (res != -EAGAIN) req->flags |= REQ_F_IOPOLL_COMPLETED; @@ -1956,8 +1963,8 @@ static int io_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe, end > 0 ? end : LLONG_MAX, fsync_flags & IORING_FSYNC_DATASYNC); - if (ret < 0 && (req->flags & REQ_F_LINK)) - req->flags |= REQ_F_FAIL_LINK; + if (ret < 0) + req_set_fail_links(req); io_cqring_add_event(req, ret); io_put_req_find_next(req, nxt); return 0; @@ -2003,8 +2010,8 @@ static int io_sync_file_range(struct io_kiocb *req, ret = sync_file_range(req->rw.ki_filp, sqe_off, sqe_len, flags); - if (ret < 0 && (req->flags & REQ_F_LINK)) - req->flags |= REQ_F_FAIL_LINK; + if (ret < 0) + req_set_fail_links(req); io_cqring_add_event(req, ret); io_put_req_find_next(req, nxt); return 0; @@ -2079,8 +2086,8 @@ static int io_sendmsg(struct io_kiocb *req, const struct io_uring_sqe *sqe, out: io_cqring_add_event(req, ret); - if (ret < 0 && (req->flags & REQ_F_LINK)) - req->flags |= REQ_F_FAIL_LINK; + if (ret < 0) + req_set_fail_links(req); io_put_req_find_next(req, nxt); return 0; #else @@ -2161,8 +2168,8 @@ static int io_recvmsg(struct io_kiocb *req, const struct io_uring_sqe *sqe, out: io_cqring_add_event(req, ret); - if (ret < 0 && (req->flags & REQ_F_LINK)) - req->flags |= REQ_F_FAIL_LINK; + if (ret < 0) + req_set_fail_links(req); io_put_req_find_next(req, nxt); return 0; #else @@ -2196,8 +2203,8 @@ static int io_accept(struct io_kiocb *req, const struct io_uring_sqe *sqe, } if (ret == -ERESTARTSYS) ret = -EINTR; - if (ret < 0 && (req->flags & REQ_F_LINK)) - req->flags |= REQ_F_FAIL_LINK; + if (ret < 0) + req_set_fail_links(req); io_cqring_add_event(req, ret); io_put_req_find_next(req, nxt); return 0; @@ -2263,8 +2270,8 @@ static int io_connect(struct io_kiocb *req, const struct io_uring_sqe *sqe, if (ret == -ERESTARTSYS) ret = -EINTR; out: - if (ret < 0 && (req->flags & REQ_F_LINK)) - req->flags |= REQ_F_FAIL_LINK; + if (ret < 0) + req_set_fail_links(req); io_cqring_add_event(req, ret); io_put_req_find_next(req, nxt); return 0; @@ -2340,8 +2347,8 @@ static int io_poll_remove(struct io_kiocb *req, const struct io_uring_sqe *sqe) spin_unlock_irq(&ctx->completion_lock); io_cqring_add_event(req, ret); - if (ret < 0 && (req->flags & REQ_F_LINK)) - req->flags |= REQ_F_FAIL_LINK; + if (ret < 0) + req_set_fail_links(req); io_put_req(req); return 0; } @@ -2399,8 +2406,8 @@ static void io_poll_complete_work(struct io_wq_work **workptr) io_cqring_ev_posted(ctx); - if (ret < 0 && req->flags & REQ_F_LINK) - req->flags |= REQ_F_FAIL_LINK; + if (ret < 0) + req_set_fail_links(req); io_put_req_find_next(req, &nxt); if (nxt) *workptr = &nxt->work; @@ -2582,8 +2589,7 @@ static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer) spin_unlock_irqrestore(&ctx->completion_lock, flags); io_cqring_ev_posted(ctx); - if (req->flags & REQ_F_LINK) - req->flags |= REQ_F_FAIL_LINK; + req_set_fail_links(req); io_put_req(req); return HRTIMER_NORESTART; } @@ -2608,8 +2614,7 @@ static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data) if (ret == -1) return -EALREADY; - if (req->flags & REQ_F_LINK) - req->flags |= REQ_F_FAIL_LINK; + req_set_fail_links(req); io_cqring_fill_event(req, -ECANCELED); io_put_req(req); return 0; @@ -2640,8 +2645,8 @@ static int io_timeout_remove(struct io_kiocb *req, io_commit_cqring(ctx); spin_unlock_irq(&ctx->completion_lock); io_cqring_ev_posted(ctx); - if (ret < 0 && req->flags & REQ_F_LINK) - req->flags |= REQ_F_FAIL_LINK; + if (ret < 0) + req_set_fail_links(req); io_put_req(req); return 0; } @@ -2655,13 +2660,19 @@ static int io_timeout_prep(struct io_kiocb *req, struct io_async_ctx *io, if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; - if (sqe->ioprio || sqe->buf_index || sqe->len != 1) + if (sqe->ioprio || sqe->buf_index || sqe->len != 1) { + printk("1\n"); return -EINVAL; - if (sqe->off && is_timeout_link) + } + if (sqe->off && is_timeout_link) { + printk("2\n"); return -EINVAL; + } flags = READ_ONCE(sqe->timeout_flags); - if (flags & ~IORING_TIMEOUT_ABS) + if (flags & ~IORING_TIMEOUT_ABS) { + printk("3\n"); return -EINVAL; + } data = &io->timeout; data->req = req; @@ -2822,8 +2833,8 @@ static void io_async_find_and_cancel(struct io_ring_ctx *ctx, spin_unlock_irqrestore(&ctx->completion_lock, flags); io_cqring_ev_posted(ctx); - if (ret < 0 && (req->flags & REQ_F_LINK)) - req->flags |= REQ_F_FAIL_LINK; + if (ret < 0) + req_set_fail_links(req); io_put_req_find_next(req, nxt); } @@ -3044,8 +3055,7 @@ static void io_wq_submit_work(struct io_wq_work **workptr) io_put_req(req); if (ret) { - if (req->flags & REQ_F_LINK) - req->flags |= REQ_F_FAIL_LINK; + req_set_fail_links(req); io_cqring_add_event(req, ret); io_put_req(req); } @@ -3179,8 +3189,7 @@ static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer) spin_unlock_irqrestore(&ctx->completion_lock, flags); if (prev) { - if (prev->flags & REQ_F_LINK) - prev->flags |= REQ_F_FAIL_LINK; + req_set_fail_links(prev); io_async_find_and_cancel(ctx, req, prev->user_data, NULL, -ETIME); io_put_req(prev); @@ -3273,8 +3282,7 @@ static void __io_queue_sqe(struct io_kiocb *req) /* and drop final reference, if we failed */ if (ret) { io_cqring_add_event(req, ret); - if (req->flags & REQ_F_LINK) - req->flags |= REQ_F_FAIL_LINK; + req_set_fail_links(req); io_put_req(req); } } @@ -3293,8 +3301,7 @@ static void io_queue_sqe(struct io_kiocb *req) if (ret) { if (ret != -EIOCBQUEUED) { io_cqring_add_event(req, ret); - if (req->flags & REQ_F_LINK) - req->flags |= REQ_F_FAIL_LINK; + req_set_fail_links(req); io_double_put_req(req); } } else @@ -3311,7 +3318,8 @@ static inline void io_queue_link_head(struct io_kiocb *req) } -#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK) +#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \ + IOSQE_IO_HARDLINK) static bool io_submit_sqe(struct io_kiocb *req, struct io_submit_state *state, struct io_kiocb **link) @@ -3349,6 +3357,9 @@ static bool io_submit_sqe(struct io_kiocb *req, struct io_submit_state *state, if (req->sqe->flags & IOSQE_IO_DRAIN) (*link)->flags |= REQ_F_DRAIN_LINK | REQ_F_IO_DRAIN; + if (req->sqe->flags & IOSQE_IO_HARDLINK) + req->flags |= REQ_F_HARDLINK; + io = kmalloc(sizeof(*io), GFP_KERNEL); if (!io) { ret = -EAGAIN; @@ -3358,13 +3369,16 @@ static bool io_submit_sqe(struct io_kiocb *req, struct io_submit_state *state, ret = io_req_defer_prep(req, io); if (ret) { kfree(io); + /* fail even hard links since we don't submit */ prev->flags |= REQ_F_FAIL_LINK; goto err_req; } trace_io_uring_link(ctx, req, prev); list_add_tail(&req->link_list, &prev->link_list); - } else if (req->sqe->flags & IOSQE_IO_LINK) { + } else if (req->sqe->flags & (IOSQE_IO_LINK|IOSQE_IO_HARDLINK)) { req->flags |= REQ_F_LINK; + if (req->sqe->flags & IOSQE_IO_HARDLINK) + req->flags |= REQ_F_HARDLINK; INIT_LIST_HEAD(&req->link_list); *link = req; diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index eabccb46edd1..ea231366f5fd 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -48,6 +48,7 @@ struct io_uring_sqe { #define IOSQE_FIXED_FILE (1U << 0) /* use fixed fileset */ #define IOSQE_IO_DRAIN (1U << 1) /* issue after inflight IO */ #define IOSQE_IO_LINK (1U << 2) /* links next sqe */ +#define IOSQE_IO_HARDLINK (1U << 3) /* like LINK, but stronger */ /* * io_uring_setup() flags -- 2.24.0