On Fri, Oct 20, 2017 at 8:29 AM, Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> wrote: > Add a test that exercises DAX's new MAP_SYNC flag. > > This test creates a file and writes to it via an mmap(), but never syncs > via fsync/msync. This process is tracked via dm-log-writes, then replayed. > > If MAP_SYNC is working the dm-log-writes replay will show the test file > with the same size that we wrote via the mmap() because each allocating > page fault included an implicit metadata sync. If MAP_SYNC isn't working > (which you can test by fiddling with the parameters to mmap()) the file > will be smaller or missing entirely. > > Note that dm-log-writes doesn't track the data that we write via the > mmap(), so we can't do any data integrity checking. We can only verify > that the metadata writes for the page faults happened. > > Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> Looks good. some nit picking... > --- > > For this test to run successfully you'll need both Jan's MAP_SYNC series: > > https://www.spinics.net/lists/linux-xfs/msg11852.html > > and my series adding DAX support to dm-log-writes: > > https://lists.01.org/pipermail/linux-nvdimm/2017-October/012972.html > > --- > .gitignore | 1 + > common/dmlogwrites | 1 - > src/Makefile | 3 +- > src/t_map_sync.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++ > tests/generic/466 | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++ > tests/generic/466.out | 3 ++ > tests/generic/group | 1 + > 7 files changed, 158 insertions(+), 2 deletions(-) > create mode 100644 src/t_map_sync.c > create mode 100755 tests/generic/466 > create mode 100644 tests/generic/466.out > > diff --git a/.gitignore b/.gitignore > index 2014c08..9fc0695 100644 > --- a/.gitignore > +++ b/.gitignore > @@ -119,6 +119,7 @@ > /src/t_getcwd > /src/t_holes > /src/t_immutable > +/src/t_map_sync > /src/t_mmap_cow_race > /src/t_mmap_dio > /src/t_mmap_fallocate > diff --git a/common/dmlogwrites b/common/dmlogwrites > index 247c744..5b57df9 100644 > --- a/common/dmlogwrites > +++ b/common/dmlogwrites > @@ -23,7 +23,6 @@ _require_log_writes() > [ -z "$LOGWRITES_DEV" -o ! -b "$LOGWRITES_DEV" ] && \ > _notrun "This test requires a valid \$LOGWRITES_DEV" > > - _exclude_scratch_mount_option dax > _require_dm_target log-writes > _require_test_program "log-writes/replay-log" > } > diff --git a/src/Makefile b/src/Makefile > index 3eb25b1..af7e7e9 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_mmap_write_ro > + t_mmap_cow_race t_mmap_fallocate fsync-err t_mmap_write_ro \ > + t_map_sync > > 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_map_sync.c b/src/t_map_sync.c > new file mode 100644 > index 0000000..8190f3c > --- /dev/null > +++ b/src/t_map_sync.c > @@ -0,0 +1,74 @@ > +#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 <unistd.h> > + > +#define MiB(a) ((a)*1024*1024) > + > +/* > + * These two defines were added to the kernel via commits entitled > + * "mm: Define MAP_SYNC and VM_SYNC flags" and > + * "mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap > + * flags", respectively. #ifndef? > + */ > +#define MAP_SYNC 0x80000 > +#define MAP_SHARED_VALIDATE 0x3 > + > +void err_exit(char *op) > +{ > + fprintf(stderr, "%s: %s\n", op, strerror(errno)); > + exit(1); > +} > + > +int main(int argc, char *argv[]) > +{ > + int page_size = getpagesize(); > + int len = MiB(1); > + int i, fd, err; > + char *data; > + > + if (argc < 2) { > + printf("Usage: %s <file>\n", basename(argv[0])); > + exit(0); > + } > + > + fd = open(argv[1], O_RDWR|O_CREAT, S_IRUSR|S_IWUSR); > + if (fd < 0) > + err_exit("fd"); > + > + ftruncate(fd, 0); O_TRUNC? > + ftruncate(fd, len); > + > + data = mmap(NULL, len, PROT_READ|PROT_WRITE, > + MAP_SHARED_VALIDATE|MAP_SYNC, fd, 0); > + if (data == MAP_FAILED) > + err_exit("mmap"); > + > + /* > + * We intentionally don't sync 'fd' manually. If MAP_SYNC is working > + * these allocating page faults will cause the filesystem to sync its > + * metadata so that when we replay the dm-log-writes log the test file > + * will be 1 MiB in size. > + * > + * dm-log-writes doesn't track the data that we write via the mmap(), > + * so we can't check that, we can only verify that the metadata writes > + * happened. > + */ > + for (i = 0; i < len; i+=page_size) > + data[i] = 0xff; > + Ideally, you would write the mark now (see mark_log() in fsx.c) Otherwise, what you are testing is not that page faults allocate disk blocks, but rather that page fault + munmap + close + process exit allocate disk blocks. I realize munmap/close are not supposed to sync dirty pages, but better eliminate this noise from the test. > + err = munmap(data, len); > + if (err < 0) > + err_exit("munmap"); > + > + err = close(fd); > + if (err < 0) > + err_exit("close"); > + > + return 0; > +} > diff --git a/tests/generic/466 b/tests/generic/466 > new file mode 100755 > index 0000000..f39e6dc > --- /dev/null > +++ b/tests/generic/466 > @@ -0,0 +1,77 @@ > +#! /bin/bash > +# FS QA Test No. 466 > +# > +# Use md_log_writes to verify that MAP_SYNC actually syncs metadata during > +# page faults. > +# > +#----------------------------------------------------------------------- > +# 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` > +status=1 # failure is the default! > +trap "_cleanup; exit \$status" 0 1 2 3 15 > + > +_cleanup() > +{ > + _log_writes_cleanup > +} > + > +# get standard environment, filters and checks > +. ./common/rc > +. ./common/filter > +. ./common/dmlogwrites > + > +# remove previous $seqres.full before test > +rm -f $seqres.full > + > +# real QA test starts here > +_supported_fs generic > +_supported_os Linux > +_require_log_writes > +_require_scratch_dax > +_require_test_program "t_map_sync" > + > +_log_writes_init > +_log_writes_mkfs >> $seqres.full 2>&1 > +_log_writes_mount -o dax > + > +src/t_map_sync $SCRATCH_MNT/test > + > +# Unmount the scratch dir and tear down the log writes target > +_log_writes_mark last Feel free to use the lousy name I chose for the pre_unmount mark ;-) but if you follow my suggestion to move the mark into t_map_sync better call it pre_munmap or something. > +_log_writes_unmount > +_log_writes_remove > +_check_scratch_fs > + > +# check pre umount > +_log_writes_replay_log last > +_scratch_mount > + > +# We should see $SCRATCH_MNT/test as 1MiB in size nit: 1MiB in disk usage. it's 1MiB in size to begin with > +du -sh $SCRATCH_MNT/test | _filter_scratch | _filter_spaces > + > +_scratch_unmount > +_check_scratch_fs > + > +echo "Silence is golden" > +status=0 > +exit > diff --git a/tests/generic/466.out b/tests/generic/466.out > new file mode 100644 > index 0000000..4c54d7a > --- /dev/null > +++ b/tests/generic/466.out > @@ -0,0 +1,3 @@ > +QA output created by 466 > +1.0M SCRATCH_MNT/test > +Silence is golden > diff --git a/tests/generic/group b/tests/generic/group > index fbe0a7f..65328c6 100644 > --- a/tests/generic/group > +++ b/tests/generic/group > @@ -468,3 +468,4 @@ > 463 auto quick clone dangerous > 464 auto rw > 465 auto rw quick aio > +466 auto quick dax > -- > 2.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe fstests" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html
