generic: test pagecache invalidation after direct write

Test if direct write invalidates pagecache correctly, so that
subsequent buffer read reads the correct data from disk.

This test is inspired by LTP tests dio29, and serves as a regression
test for the bug found by it, see kernel commit c771c14baa33
("iomap: invalidate page caches should be after iomap_dio_complete()
in direct write").

The test can be easily expanded to other write/read combinations,
e.g.  buffer write + direct read and direct write + direct read, so
they are also being tested.

Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>
This commit is contained in:
Eryu Guan
2017-03-10 17:27:38 +08:00
parent 780dd1eaff
commit 9953b149b5
6 changed files with 453 additions and 1 deletions
+1
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@@ -45,6 +45,7 @@
/src/dbtest
/src/devzero
/src/dio-interleaved
/src/dio-invalidate-cache
/src/dirperf
/src/dirstress
/src/dmiperf
+2 -1
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@@ -21,7 +21,8 @@ LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
stale_handle pwrite_mmap_blocked t_dir_offset2 seek_sanity_test \
seek_copy_test t_readdir_1 t_readdir_2 fsync-tester nsexec cloner \
renameat2 t_getcwd e4compact test-nextquota punch-alternating \
attr-list-by-handle-cursor-test listxattr dio-interleaved t_dir_type
attr-list-by-handle-cursor-test listxattr dio-interleaved t_dir_type \
dio-invalidate-cache
SUBDIRS =
+325
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@@ -0,0 +1,325 @@
/*
* Copyright (c) 2017 Red Hat Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* Fork N children, each child writes to and reads from its own region of the
* same test file, and check if what it reads is what it writes. The test
* region is determined by N * blksz. Write and read operation can be either
* direct or buffered.
*/
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <sys/file.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define DEF_BLKSZ 4096
int verbose = 0;
static void usage(const char *prog)
{
fprintf(stderr, "Usage: %s [-Fhptrwv] [-b blksz] [-n nr_child] [-i iterations] [-o offset] <-f filename>\n", prog);
fprintf(stderr, "\t-F\tPreallocate all blocks by writing them before test\n");
fprintf(stderr, "\t-p\tPreallocate all blocks using fallocate(2) before test\n");
fprintf(stderr, "\t-t\tTruncate test file to largest size before test\n");
fprintf(stderr, "\t-r\tDo direct read\n");
fprintf(stderr, "\t-w\tDo direct write\n");
fprintf(stderr, "\t-v\tBe verbose\n");
fprintf(stderr, "\t-h\tshow this help message\n");
exit(EXIT_FAILURE);
}
static int cmpbuf(char *b1, char *b2, int bsize)
{
int i;
for (i = 0; i < bsize; i++) {
if (b1[i] != b2[i]) {
fprintf(stderr, "cmpbuf: offset %d: Expected: 0x%x,"
" got 0x%x\n", i, b1[i], b2[i]);
return 1;
}
}
return 0;
}
static void kill_children(pid_t *pids, int nr_child)
{
int i;
pid_t pid;
for (i = 0; i < nr_child; i++) {
pid = pids[i];
if (pid == 0)
continue;
kill(pid, SIGTERM);
}
}
static int wait_children(pid_t *pids, int nr_child)
{
int i, status, ret = 0;
pid_t pid;
for (i = 0; i < nr_child; i++) {
pid = pids[i];
if (pid == 0)
continue;
waitpid(pid, &status, 0);
ret += WEXITSTATUS(status);
}
return ret;
}
static void dumpbuf(char *buf, int size, int blksz)
{
int i;
printf("dumping buffer content\n");
for (i = 0; i < size; i++) {
if (((i % blksz) == 0) || ((i % 64) == 0))
putchar('\n');
printf("%x", buf[i]);
}
putchar('\n');
}
static int run_test(const char *filename, int n_child, int blksz, off_t offset,
int nr_iter, int flag_rd, int flag_wr)
{
char *buf_rd;
char *buf_wr;
off_t seekoff;
int fd_rd, fd_wr;
int i, ret;
long page_size;
seekoff = offset + blksz * n_child;
page_size = sysconf(_SC_PAGESIZE);
ret = posix_memalign((void **)&buf_rd, (size_t)page_size,
blksz > page_size ? blksz : (size_t)page_size);
if (ret) {
fprintf(stderr, "posix_memalign(buf_rd, %d, %d) failed: %d\n",
blksz, blksz, ret);
exit(EXIT_FAILURE);
}
memset(buf_rd, 0, blksz);
ret = posix_memalign((void **)&buf_wr, (size_t)page_size,
blksz > page_size ? blksz : (size_t)page_size);
if (ret) {
fprintf(stderr, "posix_memalign(buf_wr, %d, %d) failed: %d\n",
blksz, blksz, ret);
exit(EXIT_FAILURE);
}
memset(buf_wr, 0, blksz);
fd_rd = open(filename, flag_rd);
if (fd_rd < 0) {
perror("open readonly for read");
exit(EXIT_FAILURE);
}
fd_wr = open(filename, flag_wr);
if (fd_wr < 0) {
perror("open writeonly for direct write");
exit(EXIT_FAILURE);
}
#define log(format, ...) \
if (verbose) { \
printf("[%d:%d] ", n_child, i); \
printf(format, __VA_ARGS__); \
}
/* seek, write, read and verify */
for (i = 0; i < nr_iter; i++) {
memset(buf_wr, i + 1, blksz);
log("pwrite(fd_wr, %p, %d, %lu)\n", buf_wr, blksz, seekoff);
if (pwrite(fd_wr, buf_wr, blksz, seekoff) != blksz) {
perror("direct write");
exit(EXIT_FAILURE);
}
/* make sure buffer write hits disk before direct read */
if (!(flag_wr & O_DIRECT)) {
if (fsync(fd_wr) < 0) {
perror("fsync(fd_wr)");
exit(EXIT_FAILURE);
}
}
log("pread(fd_rd, %p, %d, %lu)\n", buf_rd, blksz, seekoff);
if (pread(fd_rd, buf_rd, blksz, seekoff) != blksz) {
perror("buffer read");
exit(EXIT_FAILURE);
}
if (cmpbuf(buf_wr, buf_rd, blksz) != 0) {
fprintf(stderr, "[%d:%d] FAIL - comparison failed, "
"offset %d\n", n_child, i, (int)seekoff);
if (verbose)
dumpbuf(buf_rd, blksz, blksz);
exit(EXIT_FAILURE);
}
}
exit(EXIT_SUCCESS);
}
int main(int argc, char *argv[])
{
int nr_iter = 1;
int nr_child = 1;
int blksz = DEF_BLKSZ;
int fd, i, ret = 0;
int flag_rd = O_RDONLY;
int flag_wr = O_WRONLY;
int do_trunc = 0;
int pre_fill = 0;
int pre_alloc = 0;
pid_t pid;
pid_t *pids;
off_t offset = 0;
char *filename = NULL;
while ((i = getopt(argc, argv, "b:i:n:f:Fpo:tvrw")) != -1) {
switch (i) {
case 'b':
if ((blksz = atoi(optarg)) <= 0) {
fprintf(stderr, "blksz must be > 0\n");
exit(EXIT_FAILURE);
}
if (blksz % 512 != 0) {
fprintf(stderr, "blksz must be multiple of 512\n");
exit(EXIT_FAILURE);
}
break;
case 'i':
if ((nr_iter = atoi(optarg)) <= 0) {
fprintf(stderr, "iterations must be > 0\n");
exit(EXIT_FAILURE);
}
break;
case 'n':
if ((nr_child = atoi(optarg)) <= 0) {
fprintf(stderr, "no of children must be > 0\n");
exit(EXIT_FAILURE);
}
break;
case 'f':
filename = optarg;
break;
case 'F':
pre_fill = 1;
break;
case 'p':
pre_alloc = 1;
break;
case 'r':
flag_rd |= O_DIRECT;
break;
case 'w':
flag_wr |= O_DIRECT;
break;
case 't':
do_trunc = 1;
break;
case 'o':
if ((offset = atol(optarg)) < 0) {
fprintf(stderr, "offset must be >= 0\n");
exit(EXIT_FAILURE);
}
break;
case 'v':
verbose = 1;
break;
case 'h': /* fall through */
default:
usage(argv[0]);
}
}
if (filename == NULL)
usage(argv[0]);
if (pre_fill && pre_alloc) {
fprintf(stderr, "Error: -F and -p are both specified\n");
exit(EXIT_FAILURE);
}
pids = malloc(nr_child * sizeof(pid_t));
if (!pids) {
fprintf(stderr, "failed to malloc memory for pids\n");
exit(EXIT_FAILURE);
}
memset(pids, 0, nr_child * sizeof(pid_t));
/* create & truncate testfile first */
fd = open(filename, O_CREAT | O_TRUNC | O_RDWR, 0600);
if (fd < 0) {
perror("create & truncate testfile");
free(pids);
exit(EXIT_FAILURE);
}
if (do_trunc && (ftruncate(fd, blksz * nr_child) < 0)) {
perror("ftruncate failed");
free(pids);
exit(EXIT_FAILURE);
}
if (pre_fill) {
char *buf;
buf = malloc(blksz * nr_child);
memset(buf, 's', blksz * nr_child);
write(fd, buf, blksz * nr_child);
free(buf);
}
if (pre_alloc) {
fallocate(fd, 0, 0, blksz * nr_child);
}
fsync(fd);
close(fd);
/* fork workers */
for (i = 0; i < nr_child; i++) {
pid = fork();
if (pid < 0) {
perror("fork");
kill_children(pids, nr_child);
free(pids);
exit(EXIT_FAILURE);
} else if (pid == 0) {
/* never returns */
run_test(filename, i, blksz, offset, nr_iter,
flag_rd, flag_wr);
} else {
pids[i] = pid;
}
}
ret = wait_children(pids, nr_child);
free(pids);
exit(ret);
}
+122
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@@ -0,0 +1,122 @@
#! /bin/bash
# FS QA Test 418
#
# Test pagecache invalidation in buffer/direct write/read combination.
#
# Fork N children, each child writes to and reads from its own region of the
# same test file, and check if what it reads is what it writes. The test region
# is determined by N * blksz. Write and read operation can be either direct or
# buffered.
#
# Regression test for commit c771c14baa33 ("iomap: invalidate page caches
# should be after iomap_dio_complete() in direct write")
#
#-----------------------------------------------------------------------
# Copyright (c) 2017 Red Hat Inc. All Rights Reserved.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it would be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write the Free Software Foundation,
# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#-----------------------------------------------------------------------
#
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 $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
# remove previous $seqres.full before test
rm -f $seqres.full
# real QA test starts here
_supported_fs generic
_supported_os Linux
_require_test
_require_odirect
_require_block_device $TEST_DEV
_require_test_program "dio-invalidate-cache"
_require_test_program "feature"
diotest=$here/src/dio-invalidate-cache
testfile=$TEST_DIR/$seq-diotest
sectorsize=`blockdev --getss $TEST_DEV`
pagesize=`src/feature -s`
# test case array, test different write/read combinations
# -r: use direct read
# -w: use direct write
# -t: truncate file to final size before test, i.e. write to hole
# -p: fallocate whole file before test, i.e. write to allocated but unwritten extents
# -F: fulfill whole file before test, i.e. write to allocated & written extents
t_cases=(
"-w"
"-wt"
"-wp"
"-wF"
"-r"
"-rt"
"-rp"
"-rF"
"-rw"
"-rwt"
"-rwp"
"-rwF"
)
runtest()
{
local i=0
local tc=""
local loop=$1
shift
for tc in ${t_cases[*]}; do
echo "diotest $tc $*" >> $seqres.full
i=0
while [ $i -lt $loop ]; do
$diotest $tc $* -f $testfile
if [ $? -ne 0 ]; then
echo "diotest $tc $* failed at loop $i" | \
tee -a $seqres.full
break
fi
let i=i+1
done
done
}
while [ $sectorsize -le $((pagesize * 2)) ]; do
# reproducer for the original bug
runtest $((10 * LOAD_FACTOR)) -b $sectorsize -n 3 -i 1
# try more processes and iterations
runtest $((5 * LOAD_FACTOR)) -b $sectorsize -n 8 -i 4
sectorsize=$((sectorsize * 2))
done
echo "Silence is golden"
# success, all done
status=0
exit
+2
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@@ -0,0 +1,2 @@
QA output created by 418
Silence is golden
+1
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@@ -420,3 +420,4 @@
415 auto clone
416 auto enospc
417 auto quick shutdown log
418 auto rw