Am Do., 21. Nov. 2019 um 18:01 Uhr schrieb Darrick J. Wong
<darrick.wong@xxxxxxxxxx>:
> On Thu, Aug 29, 2019 at 05:44:07PM -0700, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> >
> > Andreas Grünbacher 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?
>
> Ping? Andreas, can I get the above info so I can get this moving again?
Oops, sure, this is:
Copyright (c) 2019 RedHat Inc. All Rights Reserved.
Author: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
> --D
>
> > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> > ---
> > .gitignore | 1
> > src/Makefile | 2 -
> > src/splice-test.c | 173 +++++++++++++++++++++++++++++++++++++++++++++++++
> > tests/generic/720 | 41 ++++++++++++
> > tests/generic/720.out | 7 ++
> > tests/generic/group | 1
> > 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 = xfsctl bstat t_mtab getdevicesize preallo_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
> >
> > SUBDIRS = log-writes perf
> >
> > 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:
> > + *
> > + * Make sure that reading and writing to a pipe via splice.
> > + */
> > +#include <sys/types.h>
> > +#include <sys/stat.h>
> > +#include <sys/wait.h>
> > +#include <unistd.h>
> > +#include <fcntl.h>
> > +#include <err.h>
> > +
> > +#include <stdlib.h>
> > +#include <stdio.h>
> > +#include <stdbool.h>
> > +#include <string.h>
> > +#include <errno.h>
> > +
> > +#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 = size;
> > + if (sz > sizeof buffer)
> > + sz = sizeof buffer;
> > + ret = read(fd, buffer, sz);
> > + if (ret < 0)
> > + err(1, "read: %s", filename);
> > + if (ret == 0) {
> > + fprintf(stderr, "read: %s: unexpected EOF\n", filename);
> > + exit(1);
> > + }
> > + size -= sz;
> > + }
> > +}
> > +
> > +void do_splice1(int fd, const char *filename, size_t size)
> > +{
> > + bool retried = false;
> > + int pipefd[2];
> > +
> > + if (pipe(pipefd) == -1)
> > + err(1, "pipe");
> > + while (size) {
> > + ssize_t spliced;
> > +
> > + spliced = splice(fd, NULL, pipefd[1], NULL, size, SPLICE_F_MOVE);
> > + if (spliced == -1) {
> > + if (errno == EAGAIN && !retried) {
> > + retried = true;
> > + fprintf(stderr, "retrying splice\n");
> > + sleep(1);
> > + continue;
> > + }
> > + err(1, "splice");
> > + }
> > + read_from_pipe(pipefd[0], filename, spliced);
> > + size -= spliced;
> > + }
> > + close(pipefd[0]);
> > + close(pipefd[1]);
> > +}
> > +
> > +void do_splice2(int fd, const char *filename, size_t size)
> > +{
> > + bool retried = false;
> > + int pipefd[2];
> > + int pid;
> > +
> > + if (pipe(pipefd) == -1)
> > + err(1, "pipe");
> > +
> > + pid = fork();
> > + if (pid == 0) {
> > + close(pipefd[1]);
> > + read_from_pipe(pipefd[0], filename, size);
> > + exit(0);
> > + } else {
> > + close(pipefd[0]);
> > + while (size) {
> > + ssize_t spliced;
> > +
> > + spliced = splice(fd, NULL, pipefd[1], NULL, size, SPLICE_F_MOVE);
> > + if (spliced == -1) {
> > + if (errno == EAGAIN && !retried) {
> > + retried = true;
> > + fprintf(stderr, "retrying splice\n");
> > + sleep(1);
> > + continue;
> > + }
> > + err(1, "splice");
> > + }
> > + size -= 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 = do_splice1;
> > + open_flags = O_CREAT | O_TRUNC | O_RDWR | O_DIRECT;
> > +
> > + while ((opt = getopt(argc, argv, "rd")) != -1) {
> > + switch(opt) {
> > + case 'r':
> > + do_splice = do_splice2;
> > + break;
> > + case 'd':
> > + open_flags &= ~O_DIRECT;
> > + break;
> > + default: /* '?' */
> > + usage(argv[0]);
> > + }
> > + }
> > +
> > + if (optind >= argc)
> > + usage(argv[0]);
> > + filename = argv[optind];
> > +
> > + printf("%s reader %s O_DIRECT\n",
> > + do_splice == do_splice1 ? "sequential" : "concurrent",
> > + (open_flags & O_DIRECT) ? "with" : "without");
> > +
> > + buffer = aligned_alloc(SECTOR_SIZE, BUFFER_SIZE);
> > + if (buffer == NULL)
> > + err(1, "aligned_alloc");
> > +
> > + fd = open(filename, open_flags, 0666);
> > + if (fd == -1)
> > + err(1, "open: %s", filename);
> > +
> > + memset(buffer, 'x', BUFFER_SIZE);
> > + ret = write(fd, buffer, BUFFER_SIZE);
> > + if (ret < 0)
> > + err(1, "write: %s", filename);
> > + if (ret != BUFFER_SIZE) {
> > + fprintf(stderr, "%s: short write\n", filename);
> > + exit(1);
> > + }
> > +
> > + ret = lseek(fd, 0, SEEK_SET);
> > + if (ret != 0)
> > + err(1, "lseek: %s", filename);
> > +
> > + do_splice(fd, filename, BUFFER_SIZE);
> > +
> > + if (unlink(filename) == -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=`basename $0`
> > +seqres=$RESULT_DIR/$seq
> > +echo "QA output created by $seq"
> > +
> > +here=`pwd`
> > +tmp=/tmp/$$
> > +status=1 # 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=0
> > +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
Thanks,
Andreas
