[PATCHv4 fstests] btrfs: Test subvolume delete --subvolid feature

[Marcos Paulo de Souza <marcos@mpdesouza.com>]

From: Marcos Paulo de Souza <mpdesouza@suse.com>

Now btrfs can delete subvolumes based in ther subvolume id. This makes
easy for the user willing to delete a subvolume that cannot be accessed
by the mount point, since btrfs allows to mount a specific subvolume and
hiding the other from the mount point.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
---
Changes from v3:
* Changes test 203 -> 208, since other tests were merged
* The first patch was merged, so remove it from sending again
  [https://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git/commit/?id=2f9b4039253d3a6f91cb2a22639a243b5a27e110]

Changes from v2:
* Added Reviewed-by from Nikolay to patch 0001
* Changed awk to $AWK_PROG, suggested by Eryu
* Changed _run_btrfs_util_prog to $BTRFS_UTIL_PROG, suggested by Eryu
* Use _scratch_unmount instead of executing umount by hand, sugested by Eryu
* Created a local function to delete and list subvolumes, suggested by Eryu

Changes from v1:
* Added some prints printing what is being tested
* The test now uses the _btrfs_get_subvolid to get subvolumeids instead of using
  plain integers
* New patch expanding the funtionality of _require_btrfs_command, which now
  check for argument of subcommands

 tests/btrfs/208     | 68 +++++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/208.out | 17 ++++++++++++
 tests/btrfs/group   |  1 +
 3 files changed, 86 insertions(+)
 create mode 100755 tests/btrfs/208
 create mode 100644 tests/btrfs/208.out

diff --git a/tests/btrfs/208 b/tests/btrfs/208
new file mode 100755
index 00000000..4ffc8719
--- /dev/null
+++ b/tests/btrfs/208
@@ -0,0 +1,68 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2020 SUSE Linux Products GmbH. All Rights Reserved.
+#
+# FSQA Test No. 208
+#
+# Test subvolume deletion using the subvolume id, even when the subvolume in
+# question is in a different mount space.
+#
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+tmp=/tmp/$$
+status=1	# failure is the default!
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/filter.btrfs
+
+# real QA test starts here
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch
+_require_btrfs_command subvolume delete --subvolid
+
+_scratch_mkfs > /dev/null 2>&1
+_scratch_mount
+
+_delete_and_list()
+{
+	local subvol_name="$1"
+	local msg="$2"
+
+	SUBVOLID=$(_btrfs_get_subvolid $SCRATCH_MNT "$subvol_name")
+	$BTRFS_UTIL_PROG subvolume delete --subvolid $SUBVOLID $SCRATCH_MNT | _filter_scratch
+
+	echo "$msg"
+	$BTRFS_UTIL_PROG subvolume list $SCRATCH_MNT | $AWK_PROG '{ print $NF }'
+}
+
+# Test creating a normal subvolumes
+$BTRFS_UTIL_PROG subvolume create $SCRATCH_MNT/subvol1 | _filter_scratch
+$BTRFS_UTIL_PROG subvolume create $SCRATCH_MNT/subvol2 | _filter_scratch
+$BTRFS_UTIL_PROG subvolume create $SCRATCH_MNT/subvol3 | _filter_scratch
+
+echo "Current subvolume ids:"
+$BTRFS_UTIL_PROG subvolume list $SCRATCH_MNT | $AWK_PROG '{ print $NF }'
+
+# Delete the subvolume subvol1, and list the remaining two subvolumes
+_delete_and_list subvol1 "After deleting one subvolume:"
+_scratch_unmount
+
+# Now we mount the subvol2, which makes subvol3 not accessible for this mount
+# point, but we should be able to delete it using it's subvolume id
+$MOUNT_PROG -o subvol=subvol2 $SCRATCH_DEV $SCRATCH_MNT
+_delete_and_list subvol3 "Last remaining subvolume:"
+_scratch_unmount
+
+# now mount the rootfs
+_scratch_mount
+# Delete the subvol2
+_delete_and_list subvol2 "All subvolumes removed."
+_scratch_unmount
+
+# success, all done
+status=0
+exit
diff --git a/tests/btrfs/208.out b/tests/btrfs/208.out
new file mode 100644
index 00000000..9b660699
--- /dev/null
+++ b/tests/btrfs/208.out
@@ -0,0 +1,17 @@
+QA output created by 208
+Create subvolume 'SCRATCH_MNT/subvol1'
+Create subvolume 'SCRATCH_MNT/subvol2'
+Create subvolume 'SCRATCH_MNT/subvol3'
+Current subvolume ids:
+subvol1
+subvol2
+subvol3
+Delete subvolume (no-commit): 'SCRATCH_MNT/subvol1'
+After deleting one subvolume:
+subvol2
+subvol3
+Delete subvolume (no-commit): 'SCRATCH_MNT/subvol3'
+Last remaining subvolume:
+subvol2
+Delete subvolume (no-commit): 'SCRATCH_MNT/subvol2'
+All subvolumes removed.
diff --git a/tests/btrfs/group b/tests/btrfs/group
index 94090758..4dfed8db 100644
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -210,3 +210,4 @@
 205 auto quick clone compress
 206 auto quick log replay
 207 auto rw raid
+208 auto quick subvol
-- 
2.25.0