[PATCH 3/3] ext4: test for inline data + DAX corruption

Ross Zwisler
2017-09-12T04:45:34Z

Add a regression test for the following kernel commit:

ext4: prevent data corruption with inline data + DAX

The test passes either if we don't encounter corruption, or if mounting
with DAX + inline data fails. The latter is the way that we prevent this
issue in the kernel.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
---
.gitignore | 1 +
src/Makefile | 3 +-
src/t_ext4_dax_inline_corruption.c | 70 +++++++++++++++++++++++++++++++
tests/ext4/031 | 84 ++++++++++++++++++++++++++++++++++++++
tests/ext4/031.out | 2 +
tests/ext4/group | 1 +
6 files changed, 160 insertions(+), 1 deletion(-)
create mode 100644 src/t_ext4_dax_inline_corruption.c
create mode 100755 tests/ext4/031
create mode 100644 tests/ext4/031.out

diff --git a/.gitignore b/.gitignore
index 4bdc5bf..37670e6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -155,6 +155,7 @@
/src/t_mmap_cow_race
/src/t_mmap_fallocate
/src/t_ext4_dax_journal_corruption
+/src/t_ext4_dax_inline_corruption

# dmapi/ binaries
/dmapi/src/common/cmd/read_invis
diff --git a/src/Makefile b/src/Makefile
index e6558e2..bcfae01 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -13,7 +13,8 @@ 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 fsync-err t_ext4_dax_journal_corruption
+ t_mmap_cow_race t_mmap_fallocate fsync-err t_ext4_dax_journal_corruption \
+ t_ext4_dax_inline_corruption

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/t_ext4_dax_inline_corruption.c b/src/t_ext4_dax_inline_corruption.c
new file mode 100644
index 0000000..4b7d893
--- /dev/null
+++ b/src/t_ext4_dax_inline_corruption.c
@@ -0,0 +1,70 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+#define PAGE(a) ((a)*0x1000)
+#define STRLEN 256
+
+void err_exit(char *op)
+{
+ fprintf(stderr, "%s: %s\n", op, strerror(errno));
+ exit(1);
+}
+
+int main(int argc, char *argv[])
+{
+ int fd, err, len = PAGE(1);
+ char *dax_data, *data;
+ char string[STRLEN];
+
+ if (argc < 2) {
+ printf("Usage: %s <file>\n", basename(argv[0]));
+ exit(0);
+ }
+
+ srand(time(NULL));
+ snprintf(string, STRLEN, "random number %d\n", rand());
+
+ fd = open(argv[1], O_RDWR);
+ if (fd < 0)
+ err_exit("fd");
+
+ data = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+ if (!data)
+ err_exit("mmap data");
+
+ /* this fallocate turns off inline data and turns on DAX */
+ fallocate(fd, 0, 0, PAGE(2));
+
+ dax_data = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, 0);
+ if (!dax_data)
+ err_exit("mmap dax_data");
+
+ /*
+ * Write the data using the non-DAX mapping, and try and read it back
+ * using the DAX mapping.
+ */
+ strcpy(data, string);
+ if (strcmp(dax_data, string) != 0)
+ printf("Data miscompare\n");
+
+ err = munmap(dax_data, len);
+ if (err < 0)
+ err_exit("munmap dax_data");
+
+ err = munmap(data, len);
+ if (err < 0)
+ err_exit("munmap data");
+
+ err = close(fd);
+ if (err < 0)
+ err_exit("close");
+ return 0;
+}
diff --git a/tests/ext4/031 b/tests/ext4/031
new file mode 100755
index 0000000..95a5c65
--- /dev/null
+++ b/tests/ext4/031
@@ -0,0 +1,84 @@
+#! /bin/bash
+# FS QA Test ext4/031
+#
+# This is a regression test for kernel patch:
+# ext4: prevent data corruption with inline data + DAX
+# created by Ross Zwisler <ross.zwisler@linux.intel.com>
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2017 Intel Corporation. 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
+
+# Modify as appropriate.
+_supported_os Linux
+_supported_fs ext4
+_require_scratch_dax
+_require_test_program "t_ext4_dax_inline_corruption"
+
+# real QA test starts here
+_scratch_mkfs_ext4 -O inline_data > $seqres.full 2>&1
+
+TESTFILE=$SCRATCH_MNT/testfile
+
+# DAX needs to be off so we can create an inode with inline data
+SAVE_MOUNT_OPTIONS="$MOUNT_OPTIONS"
+MOUNT_OPTIONS=""
+_scratch_mount >> $seqres.full 2>&1
+
+echo "Need to make some inline data..." > $TESTFILE
+
+export MOUNT_OPTIONS="$SAVE_MOUNT_OPTIONS"
+
+_scratch_unmount >> $seqres.full 2>&1
+_scratch_mount "-o dax" >> $seqres.full 2>&1
+
+if [[ $? != 0 ]]; then
+ # _require_scratch_dax already verified that we could mount with DAX.
+ # Failure here is expected because we have inline data.
+ echo "Silence is golden"
+ status=0
+ exit
+fi
+
+src/t_ext4_dax_inline_corruption $TESTFILE
+
+# success, all done
+echo "Silence is golden"
+status=0
+exit
diff --git a/tests/ext4/031.out b/tests/ext4/031.out
new file mode 100644
index 0000000..b3d0bb0
--- /dev/null
+++ b/tests/ext4/031.out
@@ -0,0 +1,2 @@
+QA output created by 031
+Silence is golden
diff --git a/tests/ext4/group b/tests/ext4/group
index ef768df..396f963 100644
--- a/tests/ext4/group
+++ b/tests/ext4/group
@@ -33,6 +33,7 @@
028 auto quick fsmap
029 auto quick fsmap
030 auto quick
+031 auto quick
271 auto rw quick
301 aio auto ioctl rw stress defrag
302 aio auto ioctl rw stress defrag
--
2.9.5