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, I aim
to make the kernel report them once on every file description.
This patch adds a test for the 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. For now, that's all it can do, but
we can fill it out with other commands as necessary.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
.gitignore | 1 +
common/dmerror | 13 ++-
doc/auxiliary-programs.txt | 16 ++++
src/Makefile | 2 +-
src/dmerror | 44 +++++++++
src/fsync-err.c | 223 +++++++++++++++++++++++++++++++++++++++++++++
tests/generic/999 | 77 ++++++++++++++++
tests/generic/999.out | 3 +
tests/generic/group | 1 +
9 files changed, 374 insertions(+), 6 deletions(-)
create mode 100755 src/dmerror
create mode 100644 src/fsync-err.c
create mode 100755 tests/generic/999
create mode 100644 tests/generic/999.out
diff --git a/.gitignore b/.gitignore
index 39664b0a7f53..56e863b2c8dc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -72,6 +72,7 @@
/src/fs_perms
/src/fssum
/src/fstest
+/src/fsync-err
/src/fsync-tester
/src/ftrunc
/src/genhashnames
diff --git a/common/dmerror b/common/dmerror
index d46c5d0b7266..238baa213b1f 100644
--- a/common/dmerror
+++ b/common/dmerror
@@ -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()
diff --git a/doc/auxiliary-programs.txt b/doc/auxiliary-programs.txt
index 21ef118596b6..bcab453c4335 100644
--- a/doc/auxiliary-programs.txt
+++ b/doc/auxiliary-programs.txt
@@ -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
diff --git a/src/Makefile b/src/Makefile
index 6b0e4b022485..abd0fff34a64 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -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 \
diff --git a/src/dmerror b/src/dmerror
new file mode 100755
index 000000000000..4aaf682ee5f9
--- /dev/null
+++ b/src/dmerror
@@ -0,0 +1,44 @@
+#!/bin/bash
+#-----------------------------------------------------------------------
+# Copyright (c) 2017, Jeff Layton <jlayton@xxxxxxxxxx>
+#
+# 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
diff --git a/src/fsync-err.c b/src/fsync-err.c
new file mode 100644
index 000000000000..5b3bdd3ada07
--- /dev/null
+++ b/src/fsync-err.c
@@ -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@xxxxxxxxxx>
+ */
+#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;
+}
diff --git a/tests/generic/999 b/tests/generic/999
new file mode 100755
index 000000000000..f998671ef19e
--- /dev/null
+++ b/tests/generic/999
@@ -0,0 +1,77 @@
+#! /bin/bash
+# FS QA Test No. 999
+#
+# 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@xxxxxxxxxx>
+#
+# 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_os Linux
+_require_scratch
+_require_logdev
+_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
diff --git a/tests/generic/999.out b/tests/generic/999.out
new file mode 100644
index 000000000000..2e48492ff6d1
--- /dev/null
+++ b/tests/generic/999.out
@@ -0,0 +1,3 @@
+QA output created by 999
+Format and mount
+Test passed!
diff --git a/tests/generic/group b/tests/generic/group
index 5d3e4dcf732e..b56bae8f04f0 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -442,3 +442,4 @@
437 auto quick
438 auto
439 auto quick punch
+999 auto quick
--
2.13.0
