From patchwork Tue Mar 14 15:42:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13174669 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 805CCC7618B for ; Tue, 14 Mar 2023 15:43:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230426AbjCNPnh (ORCPT ); Tue, 14 Mar 2023 11:43:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230149AbjCNPn3 (ORCPT ); Tue, 14 Mar 2023 11:43:29 -0400 Received: from mail-il1-x12c.google.com (mail-il1-x12c.google.com [IPv6:2607:f8b0:4864:20::12c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99785B0491 for ; Tue, 14 Mar 2023 08:42:51 -0700 (PDT) Received: by mail-il1-x12c.google.com with SMTP id h7so8843629ila.5 for ; Tue, 14 Mar 2023 08:42:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; t=1678808530; 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=E3FVhcqNffmfR5JCmg47xgwx5RA3GsCizvE3AY6V6/M=; b=yb1EKM8V8tRfeCVAglluf4yfTQXoJ0BfzotzgCGLkbQX6VDsv+dZk7QpnAJ8Fe9W5Z oFLXjyDH+LpMxZScMml4HKXC4K9AOlrCeukAi35l9D1pv0RwroIJRsIFeN5+jk0TowL7 FFOKezYGSJeS+9jhnygOFqDIJS+Y3ljwwGsLkQxYfKcfqypMswDAQ3rWlztGcHFnUG/9 dzrBURRCGOg/ClXofbHC9pvFanZ587E/zgforYw6stuQRbJxjqKPVRqeIEAHxx3MaW8k vXP8sf5Zzr+DWRMQOmsikydnDF+4LKtYZE+8OM6pMIDMYWAJ2Hd8r/8jsME5KkuLEEnT 2jbA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678808530; 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=E3FVhcqNffmfR5JCmg47xgwx5RA3GsCizvE3AY6V6/M=; b=1IMAb1Qf17mIToKLmNAQDnajTYXlD8p/PBgIVnx15AkXPo3OA53vMs0CCN2uiqYMIF z7EKpp7nmz9bzXLnDLcIIz/GGpq/vwMzxuZagRCo1fLR2T+O2MD8dfTFlCKZpZfkHbdL 6x8xHWsMaSUW5irji2SCuHDmwi2NgDSlI67pOr4LV76xLd/xnwF5QQUnIRVeEgEFTH6W 1t3AW1+2cAoh0mXk/yaz309o8G7h9wUkFLyrlruFTyB82r7e5GE6BtSc6r9S8IT3p3Qu rMqnL2NRuroia2FrU9VhimuyFCpv2a/R8uO2Q8pRPxQszhKOc5SC58ZODvTlqR93ec34 yrWw== X-Gm-Message-State: AO0yUKUyGrVbLaxhPwGYLsX5zKHe0yOwr5xS/OTzy5nHNrEWkbWd/Xcw EqVkNR2NdUu+edsrnh/d14FBL+xmg+hy96rle4JDDA== X-Google-Smtp-Source: AK7set9P4LeTrGDzUavLg5g2GgFP6N6RZonNdfvCtsjldCGyDmcHY8Zk5oGt3RhETk3T8MiPhhbjQQ== X-Received: by 2002:a92:b10d:0:b0:319:9153:3750 with SMTP id t13-20020a92b10d000000b0031991533750mr9874768ilh.1.1678808530072; Tue, 14 Mar 2023 08:42:10 -0700 (PDT) Received: from localhost.localdomain ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id u9-20020a02cb89000000b003b0692eb199sm867929jap.20.2023.03.14.08.42.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Mar 2023 08:42:09 -0700 (PDT) From: Jens Axboe To: io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: brauner@kernel.org, Jens Axboe , Dave Chinner Subject: [PATCH 2/3] pipe: enable handling of IOCB_NOWAIT Date: Tue, 14 Mar 2023 09:42:02 -0600 Message-Id: <20230314154203.181070-3-axboe@kernel.dk> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230314154203.181070-1-axboe@kernel.dk> References: <20230314154203.181070-1-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. Acked-by: Dave Chinner Signed-off-by: Jens Axboe Reviewed-by: Christian Brauner --- fs/pipe.c | 39 +++++++++++++++++++++++++++++++-------- 1 file changed, 31 insertions(+), 8 deletions(-) diff --git a/fs/pipe.c b/fs/pipe.c index 340f253913a2..dc00b20e56c8 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 +507,18 @@ 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 | + __GFP_HARDWALL; + int this_ret = -EAGAIN; + + if (!nonblock) { + this_ret = -ENOMEM; + gfp |= GFP_USER; + } + page = alloc_page(gfp); if (unlikely(!page)) { - ret = ret ? : -ENOMEM; + if (!ret) + ret = this_ret; break; } pipe->tmp_page = page; @@ -547,7 +570,7 @@ 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;