generic: add a writeback error handling test

I'm working on a set of kernel patches to change how writeback errors
are handled and reported in the kernel. Instead of reporting a
writeback error to only the first fsync caller on the file, it has
the the kernel report them once on every file description that was
open at the time of the error.

This patch adds a test for this new behavior. Basically, open many fds
to the same file, turn on dm_error, write to each of the fds, and then
fsync them all to ensure that they all get an error back.

To do that, I'm adding a new tools/dmerror script that the C program
can use to load the error table from the script. It's also suitable for
setting up, frobbing and tearing down a dmerror device for by-hand testing.

For now, only ext2/3/4 and xfs are whitelisted on this test, since those
filesystems are included in the initial patchset. We can add to that as
we convert filesystems, and eventually make it a more general test.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>
This commit is contained in:
Jeff Layton
2017-06-16 15:36:17 -04:00
committed by Eryu Guan
parent 39c3f812de
commit 702421f528
9 changed files with 382 additions and 7 deletions
+1
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@@ -72,6 +72,7 @@
/src/fs_perms
/src/fssum
/src/fstest
/src/fsync-err
/src/fsync-tester
/src/ftrunc
/src/genhashnames
+8 -5
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@@ -23,22 +23,25 @@ if [ $? -eq 0 ]; then
_notrun "Cannot run tests with DAX on dmerror devices"
fi
_dmerror_init()
_dmerror_setup()
{
local dm_backing_dev=$SCRATCH_DEV
$DMSETUP_PROG remove error-test > /dev/null 2>&1
local blk_dev_size=`blockdev --getsz $dm_backing_dev`
DMERROR_DEV='/dev/mapper/error-test'
DMLINEAR_TABLE="0 $blk_dev_size linear $dm_backing_dev 0"
DMERROR_TABLE="0 $blk_dev_size error $dm_backing_dev 0"
}
_dmerror_init()
{
_dmerror_setup
$DMSETUP_PROG remove error-test > /dev/null 2>&1
$DMSETUP_PROG create error-test --table "$DMLINEAR_TABLE" || \
_fatal "failed to create dm linear device"
DMERROR_TABLE="0 $blk_dev_size error $dm_backing_dev 0"
}
_dmerror_mount()
+16
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@@ -16,6 +16,8 @@ note the dependency with:
Contents:
- af_unix -- Create an AF_UNIX socket
- dmerror -- fault injection block device control
- fsync-err -- tests fsync error reporting after failed writeback
- open_by_handle -- open_by_handle_at syscall exercise
- stat_test -- statx syscall exercise
- t_dir_type -- print directory entries and their file type
@@ -30,6 +32,20 @@ af_unix
The af_unix program creates an AF_UNIX socket at the given location.
dmerror
dmerror is a program for creating, destroying and controlling a
fault injection device. The device can be set up as initially
working and then flip to throwing errors for testing purposes.
fsync-err
Specialized program for testing how the kernel reports errors that
occur during writeback. Works in conjunction with the dmerror script
in tools/ to write data to a device, and then force it to fail
writeback and test that errors are reported during fsync and cleared
afterward.
open_by_handle
The open_by_handle program exercises the open_by_handle_at() system
+2 -2
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@@ -13,7 +13,7 @@ TARGETS = dirstress fill fill2 getpagesize holes lstat64 \
multi_open_unlink dmiperf unwritten_sync genhashnames t_holes \
t_mmap_writev t_truncate_cmtime dirhash_collide t_rename_overwrite \
holetest t_truncate_self t_mmap_dio af_unix t_mmap_stale_pmd \
t_mmap_cow_race t_mmap_fallocate
t_mmap_cow_race t_mmap_fallocate fsync-err
LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
preallo_rw_pattern_writer ftrunc trunc fs_perms testx looptest \
@@ -86,7 +86,7 @@ LINKTEST = $(LTLINK) $@.c -o $@ $(CFLAGS) $(LDFLAGS)
install: default $(addsuffix -install,$(SUBDIRS))
$(INSTALL) -m 755 -d $(PKG_LIB_DIR)/src
$(LTINSTALL) -m 755 $(LDIRT) $(PKG_LIB_DIR)/src
$(LTINSTALL) -m 755 fill2attr fill2fs fill2fs_check scaleread.sh $(PKG_LIB_DIR)/src
$(LTINSTALL) -m 755 dmerror fill2attr fill2fs fill2fs_check scaleread.sh $(PKG_LIB_DIR)/src
$(LTINSTALL) -m 644 dumpfile $(PKG_LIB_DIR)/src
%-install:
Executable
+44
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@@ -0,0 +1,44 @@
#!/bin/bash
#-----------------------------------------------------------------------
# Copyright (c) 2017, Jeff Layton <jlayton@redhat.com>
#
# 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
#-----------------------------------------------------------------------
. ./common/config
. ./common/dmerror
_dmerror_setup
case $1 in
cleanup)
_dmerror_cleanup
;;
init)
_dmerror_init
;;
load_error_table)
_dmerror_load_error_table
;;
load_working_table)
_dmerror_load_working_table
;;
*)
echo "Usage: $0 {init|cleanup|load_error_table|load_working_table}"
exit 1
;;
esac
status=0
exit
+223
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@@ -0,0 +1,223 @@
/*
* fsync-err.c: test whether writeback errors are reported to all open fds
* and properly cleared as expected after being seen once on each
*
* Copyright (c) 2017: Jeff Layton <jlayton@redhat.com>
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <getopt.h>
/*
* btrfs has a fixed stripewidth of 64k, so we need to write enough data to
* ensure that we hit both stripes by default.
*/
#define DEFAULT_BUFSIZE (65 * 1024)
/* default number of fds to open */
#define DEFAULT_NUM_FDS 10
static void usage()
{
printf("Usage: fsync-err [ -b bufsize ] [ -n num_fds ] -d dmerror path <filename>\n");
}
int main(int argc, char **argv)
{
int *fd, ret, i, numfds = DEFAULT_NUM_FDS;
char *fname, *buf;
char *dmerror_path = NULL;
char *cmdbuf;
size_t cmdsize, bufsize = DEFAULT_BUFSIZE;
while ((i = getopt(argc, argv, "b:d:n:")) != -1) {
switch (i) {
case 'b':
bufsize = strtol(optarg, &buf, 0);
if (*buf != '\0') {
printf("bad string conversion: %s\n", optarg);
return 1;
}
break;
case 'd':
dmerror_path = optarg;
break;
case 'n':
numfds = strtol(optarg, &buf, 0);
if (*buf != '\0') {
printf("bad string conversion: %s\n", optarg);
return 1;
}
break;
}
}
if (argc < 1) {
usage();
return 1;
}
if (!dmerror_path) {
printf("Must specify dmerror path with -d option!\n");
return 1;
}
/* Remaining argument is filename */
fname = argv[optind];
fd = calloc(numfds, sizeof(*fd));
if (!fd) {
printf("malloc failed: %m\n");
return 1;
}
for (i = 0; i < numfds; ++i) {
fd[i] = open(fname, O_WRONLY | O_CREAT | O_TRUNC, 0644);
if (fd[i] < 0) {
printf("open of fd[%d] failed: %m\n", i);
return 1;
}
}
buf = malloc(bufsize);
if (!buf) {
printf("malloc failed: %m\n");
return 1;
}
/* fill it with some junk */
memset(buf, 0x7c, bufsize);
for (i = 0; i < numfds; ++i) {
ret = write(fd[i], buf, bufsize);
if (ret < 0) {
printf("First write on fd[%d] failed: %m\n", i);
return 1;
}
}
for (i = 0; i < numfds; ++i) {
ret = fsync(fd[i]);
if (ret < 0) {
printf("First fsync on fd[%d] failed: %m\n", i);
return 1;
}
}
/* enough for path + dmerror command string (and then some) */
cmdsize = strlen(dmerror_path) + 64;
cmdbuf = malloc(cmdsize);
if (!cmdbuf) {
printf("malloc failed: %m\n");
return 1;
}
ret = snprintf(cmdbuf, cmdsize, "%s load_error_table", dmerror_path);
if (ret < 0 || ret >= cmdsize) {
printf("sprintf failure: %d\n", ret);
return 1;
}
/* flip the device to non-working mode */
ret = system(cmdbuf);
if (ret) {
if (WIFEXITED(ret))
printf("system: program exited: %d\n",
WEXITSTATUS(ret));
else
printf("system: 0x%x\n", (int)ret);
return 1;
}
for (i = 0; i < numfds; ++i) {
ret = write(fd[i], buf, bufsize);
if (ret < 0) {
printf("Second write on fd[%d] failed: %m\n", i);
return 1;
}
}
for (i = 0; i < numfds; ++i) {
ret = fsync(fd[i]);
/* Now, we EXPECT the error! */
if (ret >= 0) {
printf("Success on second fsync on fd[%d]!\n", i);
return 1;
}
}
for (i = 0; i < numfds; ++i) {
ret = fsync(fd[i]);
if (ret < 0) {
/*
* We did a failed write and fsync on each fd before.
* Now the error should be clear since we've not done
* any writes since then.
*/
printf("Third fsync on fd[%d] failed: %m\n", i);
return 1;
}
}
/* flip the device to working mode */
ret = snprintf(cmdbuf, cmdsize, "%s load_working_table", dmerror_path);
if (ret < 0 || ret >= cmdsize) {
printf("sprintf failure: %d\n", ret);
return 1;
}
ret = system(cmdbuf);
if (ret) {
if (WIFEXITED(ret))
printf("system: program exited: %d\n",
WEXITSTATUS(ret));
else
printf("system: 0x%x\n", (int)ret);
return 1;
}
for (i = 0; i < numfds; ++i) {
ret = fsync(fd[i]);
if (ret < 0) {
/* The error should still be clear */
printf("fsync after healing device on fd[%d] failed: %m\n", i);
return 1;
}
}
/*
* reopen each file one at a time to ensure the same inode stays
* in core. fsync each one to make sure we see no errors on a fresh
* open of the inode.
*/
for (i = 0; i < numfds; ++i) {
ret = close(fd[i]);
if (ret < 0) {
printf("Close of fd[%d] returned unexpected error: %m\n", i);
return 1;
}
fd[i] = open(fname, O_WRONLY | O_CREAT | O_TRUNC, 0644);
if (fd[i] < 0) {
printf("Second open of fd[%d] failed: %m\n", i);
return 1;
}
ret = fsync(fd[i]);
if (ret < 0) {
/* New opens should not return an error */
printf("First fsync after reopen of fd[%d] failed: %m\n", i);
return 1;
}
}
printf("Test passed!\n");
return 0;
}
+84
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@@ -0,0 +1,84 @@
#! /bin/bash
# FS QA Test No. 441
#
# Open a file several times, write to it, fsync on all fds and make sure that
# they all return 0. Change the device to start throwing errors. Write again
# on all fds and fsync on all fds. Ensure that we get errors on all of them.
# Then fsync on all one last time and verify that all return 0.
#
#-----------------------------------------------------------------------
# Copyright (c) 2017, Jeff Layton <jlayton@redhat.com>
#
# 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 -rf $tmp.* $testdir
_dmerror_cleanup
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
. ./common/dmerror
# real QA test starts here
_supported_fs ext2 ext3 ext4 xfs
_supported_os Linux
_require_scratch
# Generally, we want to avoid journal errors in this test. Ensure that
# journalled fs' have a logdev.
if [ "$FSTYP" != "ext2" ]; then
_require_logdev
fi
_require_dm_target error
_require_test_program fsync-err
_require_test_program dmerror
rm -f $seqres.full
echo "Format and mount"
_scratch_mkfs > $seqres.full 2>&1
_dmerror_init
_dmerror_mount
_require_fs_space $SCRATCH_MNT 65536
testfile=$SCRATCH_MNT/fsync-err-test
$here/src/fsync-err -d $here/src/dmerror $testfile
# success, all done
_dmerror_load_working_table
_dmerror_unmount
_dmerror_cleanup
# fs may be corrupt after this -- attempt to repair it
_repair_scratch_fs >> $seqres.full
status=0
exit
+3
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@@ -0,0 +1,3 @@
QA output created by 441
Format and mount
Test passed!
+1
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@@ -443,3 +443,4 @@
438 auto
439 auto quick punch
440 auto quick encrypt
441 auto quick