From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com ([209.132.183.28]:48832 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728926AbfIBCN4 (ORCPT ); Sun, 1 Sep 2019 22:13:56 -0400 Date: Mon, 2 Sep 2019 10:20:52 +0800 From: Zorro Lang Subject: Re: [RFC PATCH] generic: test splice() with pipes Message-ID: <20190902022052.GR7239@dhcp-12-102.nay.redhat.com> References: <20190829161155.GA5360@magnolia> <20190830004407.GA5340@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20190830004407.GA5340@magnolia> Sender: fstests-owner@vger.kernel.org Content-Transfer-Encoding: quoted-printable To: "Darrick J. Wong" Cc: andreas.gruenbacher@gmail.com, xfs , viro@zeniv.linux.org.uk, linux-fsdevel , fstests List-ID: On Thu, Aug 29, 2019 at 05:44:07PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong >=20 > Andreas Gr=FCnbacher reports that on the two filesystems that support > iomap directio, it's possible for splice() to return -EAGAIN (instead o= f > a short splice) if the pipe being written to has less space available i= n > its pipe buffers than the length supplied by the calling process. >=20 > This is a regression test to check for correct operation. >=20 > XXX Andreas: Since you wrote the C reproducer, can you send me the > proper copyright and author attribution statement for the C program? >=20 > Signed-off-by: Darrick J. Wong > --- Hi Darrick, I tried to add a splice_f operation into xfs_io long time ago: https://marc.info/?l=3Dlinux-xfs&m=3D155828702128047&w=3D2 For we can easily write more splice related test case later, I'd like to = have a xfs_io to help that (if it can). Would you like to help to review that = patch, if it can match your requirement to write this case? Or it can be improve= d to cover more testing conditions? I'm really appreciate that:) Thanks, Zorro > .gitignore | 1=20 > src/Makefile | 2 - > src/splice-test.c | 173 +++++++++++++++++++++++++++++++++++++++++= ++++++++ > tests/generic/720 | 41 ++++++++++++ > tests/generic/720.out | 7 ++ > tests/generic/group | 1=20 > 6 files changed, 224 insertions(+), 1 deletion(-) > create mode 100644 src/splice-test.c > create mode 100755 tests/generic/720 > create mode 100644 tests/generic/720.out >=20 > diff --git a/.gitignore b/.gitignore > index c8c815f9..26d4da11 100644 > --- a/.gitignore > +++ b/.gitignore > @@ -112,6 +112,7 @@ > /src/runas > /src/seek_copy_test > /src/seek_sanity_test > +/src/splice-test > /src/stale_handle > /src/stat_test > /src/swapon > diff --git a/src/Makefile b/src/Makefile > index c4fcf370..2920dfb1 100644 > --- a/src/Makefile > +++ b/src/Makefile > @@ -28,7 +28,7 @@ LINUX_TARGETS =3D xfsctl bstat t_mtab getdevicesize p= reallo_rw_pattern_reader \ > attr-list-by-handle-cursor-test listxattr dio-interleaved t_dir_type = \ > dio-invalidate-cache stat_test t_encrypted_d_revalidate \ > attr_replace_test swapon mkswap t_attr_corruption t_open_tmpfiles \ > - fscrypt-crypt-util bulkstat_null_ocount > + fscrypt-crypt-util bulkstat_null_ocount splice-test > =20 > SUBDIRS =3D log-writes perf > =20 > diff --git a/src/splice-test.c b/src/splice-test.c > new file mode 100644 > index 00000000..d3c12075 > --- /dev/null > +++ b/src/splice-test.c > @@ -0,0 +1,173 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Copyright (C) 2019 ????????????????????????????? > + * Author:=20 > + * > + * Make sure that reading and writing to a pipe via splice. > + */ > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include > +#include > +#include > +#include > +#include > + > +#define SECTOR_SIZE 512 > +#define BUFFER_SIZE (150 * SECTOR_SIZE) > + > +void read_from_pipe(int fd, const char *filename, size_t size) > +{ > + char buffer[SECTOR_SIZE]; > + size_t sz; > + ssize_t ret; > + > + while (size) { > + sz =3D size; > + if (sz > sizeof buffer) > + sz =3D sizeof buffer; > + ret =3D read(fd, buffer, sz); > + if (ret < 0) > + err(1, "read: %s", filename); > + if (ret =3D=3D 0) { > + fprintf(stderr, "read: %s: unexpected EOF\n", filename); > + exit(1); > + } > + size -=3D sz; > + } > +} > + > +void do_splice1(int fd, const char *filename, size_t size) > +{ > + bool retried =3D false; > + int pipefd[2]; > + > + if (pipe(pipefd) =3D=3D -1) > + err(1, "pipe"); > + while (size) { > + ssize_t spliced; > + > + spliced =3D splice(fd, NULL, pipefd[1], NULL, size, SPLICE_F_MOVE); > + if (spliced =3D=3D -1) { > + if (errno =3D=3D EAGAIN && !retried) { > + retried =3D true; > + fprintf(stderr, "retrying splice\n"); > + sleep(1); > + continue; > + } > + err(1, "splice"); > + } > + read_from_pipe(pipefd[0], filename, spliced); > + size -=3D spliced; > + } > + close(pipefd[0]); > + close(pipefd[1]); > +} > + > +void do_splice2(int fd, const char *filename, size_t size) > +{ > + bool retried =3D false; > + int pipefd[2]; > + int pid; > + > + if (pipe(pipefd) =3D=3D -1) > + err(1, "pipe"); > + > + pid =3D fork(); > + if (pid =3D=3D 0) { > + close(pipefd[1]); > + read_from_pipe(pipefd[0], filename, size); > + exit(0); > + } else { > + close(pipefd[0]); > + while (size) { > + ssize_t spliced; > + > + spliced =3D splice(fd, NULL, pipefd[1], NULL, size, SPLICE_F_MOVE); > + if (spliced =3D=3D -1) { > + if (errno =3D=3D EAGAIN && !retried) { > + retried =3D true; > + fprintf(stderr, "retrying splice\n"); > + sleep(1); > + continue; > + } > + err(1, "splice"); > + } > + size -=3D spliced; > + } > + close(pipefd[1]); > + waitpid(pid, NULL, 0); > + } > +} > + > +void usage(const char *argv0) > +{ > + fprintf(stderr, "USAGE: %s [-rd] {filename}\n", basename(argv0)); > + exit(2); > +} > + > +int main(int argc, char *argv[]) > +{ > + void (*do_splice)(int fd, const char *filename, size_t size); > + const char *filename; > + char *buffer; > + int opt, open_flags, fd; > + ssize_t ret; > + > + do_splice =3D do_splice1; > + open_flags =3D O_CREAT | O_TRUNC | O_RDWR | O_DIRECT; > + > + while ((opt =3D getopt(argc, argv, "rd")) !=3D -1) { > + switch(opt) { > + case 'r': > + do_splice =3D do_splice2; > + break; > + case 'd': > + open_flags &=3D ~O_DIRECT; > + break; > + default: /* '?' */ > + usage(argv[0]); > + } > + } > + > + if (optind >=3D argc) > + usage(argv[0]); > + filename =3D argv[optind]; > + > + printf("%s reader %s O_DIRECT\n", > + do_splice =3D=3D do_splice1 ? "sequential" : "concurrent", > + (open_flags & O_DIRECT) ? "with" : "without"); > + > + buffer =3D aligned_alloc(SECTOR_SIZE, BUFFER_SIZE); > + if (buffer =3D=3D NULL) > + err(1, "aligned_alloc"); > + > + fd =3D open(filename, open_flags, 0666); > + if (fd =3D=3D -1) > + err(1, "open: %s", filename); > + > + memset(buffer, 'x', BUFFER_SIZE); > + ret =3D write(fd, buffer, BUFFER_SIZE); > + if (ret < 0) > + err(1, "write: %s", filename); > + if (ret !=3D BUFFER_SIZE) { > + fprintf(stderr, "%s: short write\n", filename); > + exit(1); > + } > + > + ret =3D lseek(fd, 0, SEEK_SET); > + if (ret !=3D 0) > + err(1, "lseek: %s", filename); > + > + do_splice(fd, filename, BUFFER_SIZE); > + > + if (unlink(filename) =3D=3D -1) > + err(1, "unlink: %s", filename); > + > + return 0; > +} > diff --git a/tests/generic/720 b/tests/generic/720 > new file mode 100755 > index 00000000..b7f09c40 > --- /dev/null > +++ b/tests/generic/720 > @@ -0,0 +1,41 @@ > +#! /bin/bash > +# SPDX-License-Identifier: GPL-2.0-or-later > +# Copyright (c) 2019, Oracle and/or its affiliates. All Rights Reserv= ed. > +# > +# FS QA Test No. 720 > +# > +# Test using splice() to read from pipes. > + > +seq=3D`basename $0` > +seqres=3D$RESULT_DIR/$seq > +echo "QA output created by $seq" > + > +here=3D`pwd` > +tmp=3D/tmp/$$ > +status=3D1 # failure is the default! > +trap "_cleanup; exit \$status" 0 1 2 3 15 > + > +_cleanup() > +{ > + cd / > + rm -f $TEST_DIR/a > +} > + > +# get standard environment, filters and checks > +. ./common/rc > + > +# real QA test starts here > +_supported_os Linux > +_supported_fs generic > +_require_test > + > +rm -f $seqres.full > + > +src/splice-test -r $TEST_DIR/a > +src/splice-test -rd $TEST_DIR/a > +src/splice-test $TEST_DIR/a > +src/splice-test -d $TEST_DIR/a > + > +# success, all done > +status=3D0 > +exit > diff --git a/tests/generic/720.out b/tests/generic/720.out > new file mode 100644 > index 00000000..b0fc9935 > --- /dev/null > +++ b/tests/generic/720.out > @@ -0,0 +1,7 @@ > +QA output created by 720 > +concurrent reader with O_DIRECT > +concurrent reader with O_DIRECT > +concurrent reader without O_DIRECT > +concurrent reader without O_DIRECT > +sequential reader with O_DIRECT > +sequential reader without O_DIRECT > diff --git a/tests/generic/group b/tests/generic/group > index cd418106..f75d4e60 100644 > --- a/tests/generic/group > +++ b/tests/generic/group > @@ -569,3 +569,4 @@ > 564 auto quick copy_range > 565 auto quick copy_range > 719 auto quick quota metadata > +720 auto quick rw pipe splice