#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2020 SUSE Linux Products GmbH. All Rights Reserved.
#
# FS QA Test No. btrfs/227
#
# Test that an incremental send operation succeeds, and produces the correct
# results, after removing a directory and all its files, unmounting the
# filesystem, mounting the filesystem again and creating a new file (or
# directory).
#
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"

tmp=/tmp/$$
status=1	# failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15

_cleanup()
{
	cd /
	rm -fr $send_files_dir
	rm -f $tmp.*
}

# get standard environment, filters and checks
. ./common/rc
. ./common/filter

# real QA test starts here
_supported_fs btrfs
_require_test
_require_scratch
_require_fssum

send_files_dir=$TEST_DIR/btrfs-test-$seq

rm -f $seqres.full
rm -fr $send_files_dir
mkdir $send_files_dir

_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount

mkdir $SCRATCH_MNT/dir
touch $SCRATCH_MNT/dir/file1
touch $SCRATCH_MNT/dir/file2
touch $SCRATCH_MNT/dir/file3

# Filesystem looks like:
#
# .                                     (ino 256)
# |----- dir/                           (ino 257)
#         |----- file1                  (ino 258)
#         |----- file2                  (ino 259)
#         |----- file3                  (ino 260)
#

# Now create the base snapshot, which is going to be the parent snapshot for
# a later incremental send.
$BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT \
	$SCRATCH_MNT/mysnap1 > /dev/null

$BTRFS_UTIL_PROG send -f $send_files_dir/1.snap \
	$SCRATCH_MNT/mysnap1 2>&1 1>/dev/null | _filter_scratch

# Now remove our directory and all its files.
rm -fr $SCRATCH_MNT/dir

# Unmount the filesystem and mount it again. This is to ensure that the next
# inode that is created ends up with the same inode number that our directory
# "dir" had, 257, which is the first free "objectid" available after mounting
# again the filesystem.
_scratch_cycle_mount

# Now create a new file (it could be a directory as well).
touch $SCRATCH_MNT/newfile

# Filesystem now looks like:
#
# .                                     (ino 256)
# |----- newfile                        (ino 257)
#

$BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT \
		 $SCRATCH_MNT/mysnap2 > /dev/null
$BTRFS_UTIL_PROG send -p $SCRATCH_MNT/mysnap1 -f $send_files_dir/2.snap \
		 $SCRATCH_MNT/mysnap2 2>&1 1>/dev/null | _filter_scratch

$FSSUM_PROG -A -f -w $send_files_dir/1.fssum $SCRATCH_MNT/mysnap1
$FSSUM_PROG -A -f -w $send_files_dir/2.fssum \
	-x $SCRATCH_MNT/mysnap2/mysnap1 $SCRATCH_MNT/mysnap2

# Now recreate the filesystem by receiving both send streams and verify we get
# the same content that the original filesystem had.
_scratch_unmount
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount

$BTRFS_UTIL_PROG receive -f $send_files_dir/1.snap $SCRATCH_MNT > /dev/null

# The receive operation below used to fail with the following error:
#
#    ERROR: chown o257-9-0 failed: No such file or directory
#
# This is because when the kernel was processing old inode 257 (the directory),
# it had to delay its removal because its children inodes, "file1", "file2" and
# "file3", have higher inode numbers and will be processed (and unlinked) later.
# Then when it processed the new inode 257 (named "newfile"), it got confused
# and though that this inode was the one with a delayed removal and therefore
# generate an orphan name for it ("o257-9-0") instead of its current name of
# "newfile", causing the receiver to fail since there is no file with that
# orphan name.
#
$BTRFS_UTIL_PROG receive -f $send_files_dir/2.snap $SCRATCH_MNT > /dev/null

$FSSUM_PROG -r $send_files_dir/1.fssum $SCRATCH_MNT/mysnap1
$FSSUM_PROG -r $send_files_dir/2.fssum $SCRATCH_MNT/mysnap2

status=0
exit