From patchwork Wed Mar 8 03:10:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13165159 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ADAF1C742A7 for ; Wed, 8 Mar 2023 03:10:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229845AbjCHDKl (ORCPT ); Tue, 7 Mar 2023 22:10:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229823AbjCHDKj (ORCPT ); Tue, 7 Mar 2023 22:10:39 -0500 Received: from mail-pj1-x102e.google.com (mail-pj1-x102e.google.com [IPv6:2607:f8b0:4864:20::102e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B50F0A6BF5 for ; Tue, 7 Mar 2023 19:10:38 -0800 (PST) Received: by mail-pj1-x102e.google.com with SMTP id p3-20020a17090ad30300b0023a1cd5065fso754494pju.0 for ; Tue, 07 Mar 2023 19:10:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; t=1678245038; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=kpOYI77LDBDSfPAfwwRt1IR4K3PYUasWejfFHEWKzrs=; b=28A1NjE30HTD+asdxPYf8DzArFMcDjuiPdxuZMzIxfeDsw7pDY5se8eryy8cWFVHfm jjwmTkIhTe2nCW+769jYilH2PSiDQZbhznHzbA20FqrCYz2sdSikQV8Uaml031aPa8tW 3bmyxFUpaZyVQ1GCWPiEJUn36QANvNy17SYBljOfW6f2k832AhkKg7gJ8udbx/34bBQD Jf1tTe+sUjRoupjef+6PO5eVImawNPAzfLOv4jOiShmfGz6fRFCIqp/GtO3pojm5IzXh oNYWnr3YxGhRMT7RRHJbo/8BokHhIUl/flLjVqd2J8fYKJ7OCYBvubrH+KGnGERYRNiO dixg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678245038; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=kpOYI77LDBDSfPAfwwRt1IR4K3PYUasWejfFHEWKzrs=; b=5HZbdTDIccYE8f+NxzL3U7d1ecAwJIWUuOVHI+QDqBdnlM69ckw25tzMba3AeAJ1nw u6GGwklOneXZzzGuIVY8J3CECw4s9L0PS5OGZRY9AkoCLpsPOiiDrevHOr9ROoizw8AK LhjZmef3KHV9pGgZm/itHTmm8DIMSlhHQA3r6IyaiSUmKKgPoCHbYC+9Iinhq2awL7uO oHlm7LguHox9jyWYDMRtGVi9O1rAWwkPtpetuaT9g3oMHPYT/Q9jXWyKOjV8HR0W1Wmj bhJrDx0DWxBY/uzMbsXZEXlpXGkjmqmOeMHTwaysMsZa4Ui8L8zli7Fa7TQ4whnUAtmr oT1w== X-Gm-Message-State: AO0yUKV4UvLLeIbhutEQxqkPODp/xmktFyuyV1Ta/Lq4gk2TyZxNIPqc kYGxbZTvvXlM7QZoLyMImvHygw== X-Google-Smtp-Source: AK7set9P/NvInaGn9QDKHdaeF4xOJEM57oUTET3ZmNIBvpz6ZjXYEssRa+eP6vFHJhPaurfm6lvLJw== X-Received: by 2002:a17:90a:9805:b0:230:dc97:9da2 with SMTP id z5-20020a17090a980500b00230dc979da2mr12906048pjo.1.1678245038157; Tue, 07 Mar 2023 19:10:38 -0800 (PST) Received: from localhost.localdomain ([50.233.106.125]) by smtp.gmail.com with ESMTPSA id o44-20020a17090a0a2f00b0023440af7aafsm7995806pjo.9.2023.03.07.19.10.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Mar 2023 19:10:37 -0800 (PST) From: Jens Axboe To: io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: Jens Axboe Subject: [PATCH 2/3] pipe: enable handling of IOCB_NOWAIT Date: Tue, 7 Mar 2023 20:10:32 -0700 Message-Id: <20230308031033.155717-3-axboe@kernel.dk> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230308031033.155717-1-axboe@kernel.dk> References: <20230308031033.155717-1-axboe@kernel.dk> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org In preparation for enabling FMODE_NOWAIT for pipes, ensure that the read and write path handle it correctly. This includes the pipe locking, page allocation for writes, and confirming pipe buffers. Signed-off-by: Jens Axboe --- fs/pipe.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) diff --git a/fs/pipe.c b/fs/pipe.c index 340f253913a2..10366a6cb5b6 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -108,6 +108,16 @@ static inline void __pipe_unlock(struct pipe_inode_info *pipe) mutex_unlock(&pipe->mutex); } +static inline bool __pipe_trylock(struct pipe_inode_info *pipe, bool nonblock) +{ + if (!nonblock) { + __pipe_lock(pipe); + return true; + } + + return mutex_trylock(&pipe->mutex); +} + void pipe_double_lock(struct pipe_inode_info *pipe1, struct pipe_inode_info *pipe2) { @@ -234,6 +244,7 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to) struct file *filp = iocb->ki_filp; struct pipe_inode_info *pipe = filp->private_data; bool was_full, wake_next_reader = false; + const bool nonblock = iocb->ki_flags & IOCB_NOWAIT; ssize_t ret; /* Null read succeeds. */ @@ -241,7 +252,8 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to) return 0; ret = 0; - __pipe_lock(pipe); + if (!__pipe_trylock(pipe, nonblock)) + return -EAGAIN; /* * We only wake up writers if the pipe was full when we started @@ -297,7 +309,7 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to) chars = total_len; } - error = pipe_buf_confirm(pipe, buf, false); + error = pipe_buf_confirm(pipe, buf, nonblock); if (error) { if (!ret) ret = error; @@ -342,7 +354,7 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to) break; if (ret) break; - if (filp->f_flags & O_NONBLOCK) { + if (filp->f_flags & O_NONBLOCK || nonblock) { ret = -EAGAIN; break; } @@ -423,12 +435,14 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) ssize_t chars; bool was_empty = false; bool wake_next_writer = false; + const bool nonblock = iocb->ki_flags & IOCB_NOWAIT; /* Null write succeeds. */ if (unlikely(total_len == 0)) return 0; - __pipe_lock(pipe); + if (!__pipe_trylock(pipe, nonblock)) + return -EAGAIN; if (!pipe->readers) { send_sig(SIGPIPE, current, 0); @@ -461,7 +475,7 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) if ((buf->flags & PIPE_BUF_FLAG_CAN_MERGE) && offset + chars <= PAGE_SIZE) { - ret = pipe_buf_confirm(pipe, buf, false); + ret = pipe_buf_confirm(pipe, buf, nonblock); if (ret) goto out; @@ -493,9 +507,13 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) int copied; if (!page) { - page = alloc_page(GFP_HIGHUSER | __GFP_ACCOUNT); + gfp_t gfp = __GFP_HIGHMEM | __GFP_ACCOUNT; + + if (!nonblock) + gfp |= GFP_USER; + page = alloc_page(gfp); if (unlikely(!page)) { - ret = ret ? : -ENOMEM; + ret = ret ? : nonblock ? -EAGAIN : -ENOMEM; break; } pipe->tmp_page = page; @@ -547,7 +565,7 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) continue; /* Wait for buffer space to become available. */ - if (filp->f_flags & O_NONBLOCK) { + if (filp->f_flags & O_NONBLOCK || nonblock) { if (!ret) ret = -EAGAIN; break;