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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00AC4C433EF for ; Mon, 2 May 2022 07:02:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353644AbiEBHF3 (ORCPT ); Mon, 2 May 2022 03:05:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238801AbiEBHF1 (ORCPT ); Mon, 2 May 2022 03:05:27 -0400 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E2D9C6460; Mon, 2 May 2022 00:01:58 -0700 (PDT) Received: by mail-pj1-x102a.google.com with SMTP id gj17-20020a17090b109100b001d8b390f77bso15408208pjb.1; Mon, 02 May 2022 00:01:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=t7MLSEk1Zg4N4Mn5YyAWZbEoas0CNhuGYCu9wwnw6i0=; b=ahirv5dzvVouAXT8RwoOabSoKNJRRFLUSaFEEDTZHdRUVq8VW4Lg+/2s7OcTUPj+LF e/Gub+1gSkUehxRdDEmTx8QS4LhPhfbBlFWTAYI3NNvlq4OpoH6wDUAwjxQ0TzoUQVWQ zuawSMlfn12c9eNHRqiLgln342w45ahqetAY825Q4YzsyV/5IN0P1dZSgByv04NeM6cv 1nj7oIwFez4xYH5gp8kvEvBPQxkacKDdCBPvha7MRShPSEtAphDqOZuWNx8tfp0J5+ZV k9njEY5PmaM/hWLDv4jjUwTmP98fgYJPWVSeU+wGwxGxns5rqc45RsuW7hqGpuindlCE YCcQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=t7MLSEk1Zg4N4Mn5YyAWZbEoas0CNhuGYCu9wwnw6i0=; b=kWQCx5yRvEI/Oyc+zvtGgn0pqhVUPi1wVtwhD30zr0xHSUEH0C8MHi1y5dWBcl1igP zoPeJgKiue7Kyd7dT6wHYD0Qhdo8M09ksu5KDQ6koPMW9B3hLXnrBf5QE2J8oEfy5rZ6 zYJHE+VHtYHFYzTImdY01uPi3F1eZCGerj78sxr7nom3RTRJp1kZ0Vn+XM4u6tHedtIt 1GE5q0BObwtZlGzvFishOIetdCSzNV51Eq6D90VDVJIvoNtP+c8BfqN23bUt1HbCCBER 9+56WaMUXNGVZ2ZiGhE6hR6CGXI77MErDZkYXdRE90YeurN0mZlRnzifJXSbTiZosylH trog== X-Gm-Message-State: AOAM532cG43wWpHctFpnAjABDzbZC7k01/MJRCPQSID0bO7n8fBAOA6X XLPTlkXRdzyM8wf8jTxzzJCsG6jqz/qlkczrKnlt9nvcM58VnQ== X-Google-Smtp-Source: ABdhPJyLnXWeFBYfu0Jytog6gpjuXEhblMXCokzspuU4e1BS5ALMzpdzv00HDfvDy9mglADiTH0OmM5KUFbsINklhtk= X-Received: by 2002:a17:90b:380b:b0:1dc:6d24:76ff with SMTP id mq11-20020a17090b380b00b001dc6d2476ffmr393653pjb.42.1651474917714; Mon, 02 May 2022 00:01:57 -0700 (PDT) MIME-Version: 1.0 References: <20220415005015.525191-1-avagin@gmail.com> In-Reply-To: <20220415005015.525191-1-avagin@gmail.com> From: Andrei Vagin Date: Mon, 2 May 2022 00:01:46 -0700 Message-ID: Subject: Re: [PATCH] fs: sendfile handles O_NONBLOCK of out_fd To: LKML , Andrew Morton Cc: linux-fsdevel , stable@kernel.org, Alexander Viro Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Andrew, could you take a look at this patch? Here is a small reproducer for the problem: #define _GNU_SOURCE /* See feature_test_macros(7) */ #include #include #include #include #include #include #include #define FILE_SIZE (1UL << 30) int main(int argc, char **argv) { int p[2], fd; if (pipe2(p, O_NONBLOCK)) return 1; fd = open(argv[1], O_RDWR | O_TMPFILE, 0666); if (fd < 0) return 1; ftruncate(fd, FILE_SIZE); if (sendfile(p[1], fd, 0, FILE_SIZE) == -1) { fprintf(stderr, "FAIL\n"); } if (sendfile(p[1], fd, 0, FILE_SIZE) != -1 || errno != EAGAIN) { fprintf(stderr, "FAIL\n"); } return 0; } It worked before b964bf53e540, it is stuck after b964bf53e540, and it works again with this fix. Thanks, Andrei On Thu, Apr 14, 2022 at 5:50 PM Andrei Vagin wrote: > > sendfile has to return EAGAIN if out_fd is nonblocking and the write > into it would block. > > Cc: Al Viro > Cc: stable@kernel.org > Fixes: b964bf53e540 ("teach sendfile(2) to handle send-to-pipe directly") > Signed-off-by: Andrei Vagin > --- > fs/read_write.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/read_write.c b/fs/read_write.c > index e643aec2b0ef..ee59419cbf0f 100644 > --- a/fs/read_write.c > +++ b/fs/read_write.c > @@ -1247,6 +1247,9 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, > count, fl); > file_end_write(out.file); > } else { > + if (out.file->f_flags & O_NONBLOCK) > + fl |= SPLICE_F_NONBLOCK; > + > retval = splice_file_to_pipe(in.file, opipe, &pos, count, fl); > } > > -- > 2.35.1 >