From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from userp2120.oracle.com ([156.151.31.85]:52388 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727065AbfH3AoN (ORCPT ); Thu, 29 Aug 2019 20:44:13 -0400 Date: Thu, 29 Aug 2019 17:44:07 -0700 From: "Darrick J. Wong" Subject: [RFC PATCH] generic: test splice() with pipes Message-ID: <20190830004407.GA5340@magnolia> References: <20190829161155.GA5360@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20190829161155.GA5360@magnolia> Sender: fstests-owner@vger.kernel.org Content-Transfer-Encoding: quoted-printable To: andreas.gruenbacher@gmail.com Cc: xfs , viro@zeniv.linux.org.uk, linux-fsdevel , fstests List-ID: From: Darrick J. Wong Andreas Gr=FCnbacher reports that on the two filesystems that support iomap directio, it's possible for splice() to return -EAGAIN (instead of a short splice) if the pipe being written to has less space available in its pipe buffers than the length supplied by the calling process. This is a regression test to check for correct operation. XXX Andreas: Since you wrote the C reproducer, can you send me the proper copyright and author attribution statement for the C program? Signed-off-by: Darrick J. Wong --- .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 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 pre= allo_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 Reserved. +# +# 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