Re: [PATCH 05/12] btrfs: verify that subvolume mounts are unaffected by tempfsid

From: Filipe Manana <fdmanana@kernel.org>
To: Anand Jain <anand.jain@oracle.com>
Cc: fstests@vger.kernel.org, linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 05/12] btrfs: verify that subvolume mounts are unaffected by tempfsid
Date: Thu, 15 Feb 2024 12:20:17 +0000	[thread overview]
Message-ID: <CAL3q7H4TN83FV+At=pp5n6AQGCUQ=WfOY9V81EPz63zoiqk-5A@mail.gmail.com> (raw)
In-Reply-To: <c5db412fcb3d6d7dedc2f75d1384f78a5bbc2cb5.1707969354.git.anand.jain@oracle.com>

On Thu, Feb 15, 2024 at 6:35 AM Anand Jain <anand.jain@oracle.com> wrote:
>
> The tempfsid logic must determine whether the incoming mount request
> is for a device already mounted or a new device mount. Verify that it
> recognizes the device already mounted well by creating reflink across
> the subvolume mount points.
>
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> ---
>  tests/btrfs/311     | 91 +++++++++++++++++++++++++++++++++++++++++++++
>  tests/btrfs/311.out | 24 ++++++++++++
>  2 files changed, 115 insertions(+)
>  create mode 100755 tests/btrfs/311
>  create mode 100644 tests/btrfs/311.out
>
> diff --git a/tests/btrfs/311 b/tests/btrfs/311
> new file mode 100755
> index 000000000000..71c26055fa1e
> --- /dev/null
> +++ b/tests/btrfs/311
> @@ -0,0 +1,91 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2024 Oracle. All Rights Reserved.
> +#
> +# FS QA Test 311
> +#
> +# Mount the device twice check if the reflink works, this helps to
> +# ensure device is mounted as the same device.
> +#
> +. ./common/preamble
> +_begin_fstest auto quick tempfsid

Also 'subvol' group, as the test creates a subvolume and makes
something with it.

> +
> +# Override the default cleanup function.
> +_cleanup()
> +{
> +       cd /
> +       umount $mnt1 > /dev/null 2>&1

Use $UMOUNT_PROG please.

> +       rm -r -f $tmp.*
> +       rm -r -f $mnt1
> +}
> +
> +. ./common/filter.btrfs
> +. ./common/reflink
> +
> +# Modify as appropriate.
> +_supported_fs btrfs
> +_require_cp_reflink
> +_require_btrfs_sysfs_fsid
> +_require_btrfs_fs_feature temp_fsid
> +_require_btrfs_command inspect-internal dump-super
> +_require_scratch
> +
> +mnt1=$TEST_DIR/$seq/mnt1
> +mkdir -p $mnt1
> +
> +same_dev_mount()
> +{
> +       echo ---- $FUNCNAME ----
> +
> +       _scratch_mkfs >> $seqres.full 2>&1
> +
> +       _scratch_mount
> +       $XFS_IO_PROG -fc 'pwrite -S 0x61 0 9000' $SCRATCH_MNT/foo | \
> +                                                               _filter_xfs_io
> +
> +       echo Mount the device again to a different mount point
> +       _mount $SCRATCH_DEV $mnt1
> +
> +       _cp_reflink $SCRATCH_MNT/foo $mnt1/bar || \
> +               _fail "reflink failed, check if mounted as the same device"

What's the _fail for?
If cp fails it outputs an error and causes a mismatch with the golden
output, automatically failing the
test and in an easy way to notice the failure was due to a cp failure...

> +       echo Checksum of reflinked files
> +       md5sum $SCRATCH_MNT/foo | _filter_scratch
> +       md5sum $mnt1/bar | _filter_test_dir
> +
> +       check_fsid $SCRATCH_DEV
> +}
> +
> +same_dev_subvol_mount()
> +{
> +       echo ---- $FUNCNAME ----
> +       _scratch_mkfs >> $seqres.full 2>&1
> +
> +       _scratch_mount
> +       $BTRFS_UTIL_PROG subvolume create $SCRATCH_MNT/subvol
> +
> +       $XFS_IO_PROG -fc 'pwrite -S 0x61 0 9000' $SCRATCH_MNT/subvol/foo | \
> +                                                               _filter_xfs_io
> +
> +       echo Mounting a subvol
> +       _mount -o subvol=subvol $SCRATCH_DEV $mnt1
> +
> +       _cp_reflink $SCRATCH_MNT/subvol/foo $mnt1/bar || \
> +                       _fail "reflink failed, not the same device?"

Same as above.

Thanks.

> +       echo Checksum of reflinked files
> +       md5sum $SCRATCH_MNT/subvol/foo | _filter_scratch
> +       md5sum $mnt1/bar | _filter_test_dir
> +
> +       check_fsid $SCRATCH_DEV
> +}
> +
> +same_dev_mount
> +
> +_scratch_unmount
> +_cleanup
> +mkdir -p $mnt1
> +
> +same_dev_subvol_mount
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/btrfs/311.out b/tests/btrfs/311.out
> new file mode 100644
> index 000000000000..8787f24ab867
> --- /dev/null
> +++ b/tests/btrfs/311.out
> @@ -0,0 +1,24 @@
> +QA output created by 311
> +---- same_dev_mount ----
> +wrote 9000/9000 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +Mount the device again to a different mount point
> +Checksum of reflinked files
> +42d69d1a6d333a7ebdf64792a555e392  SCRATCH_MNT/foo
> +42d69d1a6d333a7ebdf64792a555e392  TEST_DIR/311/mnt1/bar
> +On disk fsid:          FSID
> +Metadata uuid:         FSID
> +Temp fsid:             FSID
> +Tempfsid status:       0
> +---- same_dev_subvol_mount ----
> +Create subvolume '/mnt/scratch/subvol'
> +wrote 9000/9000 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +Mounting a subvol
> +Checksum of reflinked files
> +42d69d1a6d333a7ebdf64792a555e392  SCRATCH_MNT/subvol/foo
> +42d69d1a6d333a7ebdf64792a555e392  TEST_DIR/311/mnt1/bar
> +On disk fsid:          FSID
> +Metadata uuid:         FSID
> +Temp fsid:             FSID
> +Tempfsid status:       0
> --
> 2.39.3
>
>