btrfs: verify that subvolume mounts are unaffected by tempfsid

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.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>

diff --git a/tests/btrfs/311 b/tests/btrfs/311
new file mode 100755 (executable)
index 0000000..7de8f05
--- /dev/null
+++ b/tests/btrfs/311
@@ -0,0 +1,87 @@
+#! /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 subvol tempfsid
+
+# Override the default cleanup function.
+_cleanup()
+{
+       cd /
+       $UMOUNT_PROG $mnt1 > /dev/null 2>&1
+       rm -r -f $tmp.*
+       rm -r -f $mnt1
+}
+
+. ./common/filter.btrfs
+. ./common/reflink
+
+# Modify as appropriate.
+_supported_fs btrfs
+_require_cp_reflink
+_require_scratch
+_require_btrfs_fs_feature temp_fsid
+
+mnt1=$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
+       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 | _filter_scratch
+
+       $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
+       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 (file)
index 0000000..4ea46ea
--- /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 'SCRATCH_MNT/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