On 2021/2/20 0:44, XiaoLi Feng wrote:
> From: Xiaoli Feng <xifeng@xxxxxxxxxx>
>
> After upstream linux patches(77573fa310d, 88149082bb8), if
> FS_XFLAG_DAX is set, DONTCACHE is also set. So S_DAX on the file
What do you mean that if FS_XFLAG_DAX is set, DONTCACHE is also set?
It seems that enabling FS_XFLAG_DAX will set DCACHE_DONTCACHE and
I_DONTCACHE automatically.
> should be active immediately once FS_XFLAG_DAX is set.
> ---
> tests/generic/608 | 42 ++++++++++++++++++++----------------------
> 1 file changed, 20 insertions(+), 22 deletions(-)
>
> diff --git a/tests/generic/608 b/tests/generic/608
> index dd89d91c..b207602e 100755
> --- a/tests/generic/608
> +++ b/tests/generic/608
> @@ -6,7 +6,10 @@
> # Change FS_XFLAG_DAX on an existing file and check if S_DAX on
> # the file can take effect immediately by the following steps:
> # 1) Stop all applications which are using the file.
> -# 2) Do drop_caches or umount & mount cycle.
> +# 2) Enable the dax flag on the file that no applications are using.
How about the following comment:
1) When no applications are using an existing file, changing FS_XFLAG_DAX
on the file make S_DAX take effect immediately.
2) When some applications are using an existing file, changing FS_XFLAG_DAX
on the file make S_DAX take effect immediately util all applications stop
using it.
> +# The upstream commit 88149082bb8 make the S_DAX take effect
> +# immediately because the inode is no longer cached and will re-read
> +# from disk.
Commit 77573fa310d makes S_DAX take effect immediately(i.e. don't depend
drop_caches or umount & mount cycle).
Commit 88149082bb8 is trying to resolve another bug.
>
> seq=`basename $0`
> seqres=$RESULT_DIR/$seq
> @@ -36,7 +39,7 @@ _require_dax_iflag
> _require_xfs_io_command "lsattr" "-v"
> _require_xfs_io_command "statx" "-r"
>
> -test_drop_caches()
> +test_caches()
> {
> local t_file=$SCRATCH_MNT/testfile
>
> @@ -49,24 +52,19 @@ test_drop_caches()
>
> $XFS_IO_PROG -c 'chattr +x' $t_file
> _check_xflag $t_file 1
> - _check_s_dax $t_file 0
> -
> # One application is using test file and check if S_DAX on
> - # the file doesn't take effect immediately by drop_caches
> - echo 2 > /proc/sys/vm/drop_caches
> + # the file doesn't take effect immediately.
> _check_s_dax $t_file 0
>
> exec 3<&-
>
> # No application is using test file and check if S_DAX on
> - # the file takes effect immediately by drop_caches
> - echo 2 > /proc/sys/vm/drop_caches
> + # the file takes effect immediately
> _check_s_dax $t_file 1
> }
>
> -test_cycle_mount()
> +test_nocache()
> {
> - local option=$1
> local t_dir=$SCRATCH_MNT/testdir
> local t_file=$t_dir/testfile
>
> @@ -77,30 +75,30 @@ test_cycle_mount()
> _check_xflag $t_file 1
> _check_s_dax $t_file 1
>
> - exec 3< $t_file
> -
> - $XFS_IO_PROG -c 'chattr -x' $t_file
> + $XFS_IO_PROG -c 'chattr -x -R' $t_dir
> _check_xflag $t_file 0
> - _check_s_dax $t_file 1
> + _check_s_dax $t_file 0
>
> - exec 3<&-
> + $XFS_IO_PROG -c 'chattr +x' $t_file
> + # Here S_DAX on the file will take effect immediately
> + # because of inode DONTCACHE.
> + _check_xflag $t_file 1
> + _check_s_dax $t_file 1
Why do you need the extra steps?
------------------------------------
78 $XFS_IO_PROG -c 'chattr -x -R' $t_dir
79 _check_xflag $t_file 0
80 _check_s_dax $t_file 0
81
82 $XFS_IO_PROG -c 'chattr +x' $t_file
83 # Here S_DAX on the file will take effect immediately
84 # because of inode DONTCACHE.
85 _check_xflag $t_file 1
86 _check_s_dax $t_file 1
------------------------------------
Best Regards,
Xiao Yang
>
> - # No application is using test file and check if S_DAX on
> - # the file takes effect immediately by umount & mount
> - _scratch_cycle_mount "$option"
> + $XFS_IO_PROG -c 'chattr -x' $t_file
> + _check_xflag $t_file 0
> _check_s_dax $t_file 0
> }
>
> do_tests()
> {
> local mount_option=$1
> - local cycle_mount_option=$2
>
> _scratch_mount "$mount_option"
>
> - test_drop_caches
> + test_caches
>
> - test_cycle_mount "$cycle_mount_option"
> + test_nocache
>
> _scratch_unmount
> }
> @@ -108,7 +106,7 @@ do_tests()
> _scratch_mkfs >> $seqres.full 2>&1
>
> # Mount with dax option
> -do_tests "-o dax=inode" "dax=inode"
> +do_tests "-o dax=inode"
>
> # Mount without dax option
> export MOUNT_OPTIONS=""
