#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2020 SUSE Linux Products GmbH. All Rights Reserved.
#
# FS QA Test No. btrfs/226
#
# Test several (btrfs specific) scenarios with RWF_NOWAIT writes, cases where
# they should fail and cases where they should succeed.
#
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 -f $tmp.*
}

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

# real QA test starts here
_supported_fs btrfs
_require_scratch_reflink
_require_chattr C
_require_odirect
_require_xfs_io_command pwrite -N
_require_xfs_io_command falloc -k
_require_xfs_io_command fpunch

rm -f $seqres.full

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

# Test a write against COW file/extent - should fail with -EAGAIN. Disable the
# NOCOW attribute of the file just in case MOUNT_OPTIONS has "-o nodatacow".
echo "Testing write against COW file"
touch $SCRATCH_MNT/f1
$CHATTR_PROG -C $SCRATCH_MNT/f1
$XFS_IO_PROG -s -c "pwrite -S 0xab 0 128K" $SCRATCH_MNT/f1 | _filter_xfs_io
$XFS_IO_PROG -d -c "pwrite -N -V 1 -S 0xff 32K 64K" $SCRATCH_MNT/f1

# Check no data was written.
echo "File data after write attempt:"
od -A d -t x1 $SCRATCH_MNT/f1

# Create a file with two extents (NOCOW), then create a snapshot, unshare the
# first extent by writing to it without RWF_NOWAIT, and then attempt to write
# to a file range that includes both the non-shared and the shared extent -
# should fail with -EAGAIN.
echo
echo "Testing write against extent shared across snapshots"
touch $SCRATCH_MNT/f2
$CHATTR_PROG +C $SCRATCH_MNT/f2
$XFS_IO_PROG -s -c "pwrite -S 0xab 0 64K" \
	     -c "pwrite -S 0xcd 64K 64K" \
	     $SCRATCH_MNT/f2 | _filter_xfs_io

$BTRFS_UTIL_PROG subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/snap \
    | _filter_scratch

# Write into the range of the first extent so that that range no longer has a
# shared extent.
$XFS_IO_PROG -s -c "pwrite -S 0xab 0 64K" $SCRATCH_MNT/f2 | _filter_xfs_io

# Attempt to write into the file range, using RWF_NOWAIT, that covers the
# non-shared and the shared extents, should fail.
$XFS_IO_PROG -d -c "pwrite -N -V 1 -S 0xff -b 64K 32K 64K" $SCRATCH_MNT/f2

# Check no data was written.
echo "File data after write attempt:"
od -A d -t x1 $SCRATCH_MNT/f2

# Create a file that has an extent shared with file f2. Attempting to write
# into a range that covers the shared extent should fail with -EAGAIN.
echo
echo "Testing write against shared extent through reflink"
touch $SCRATCH_MNT/f3
$CHATTR_PROG +C $SCRATCH_MNT/f3
$XFS_IO_PROG -s -c "pwrite -S 0xab -b 64K 0 64K" \
	     -c "reflink $SCRATCH_MNT/f2 64K 64K 64K" \
	     $SCRATCH_MNT/f3 | _filter_xfs_io

# Should fail, range 64K to 96K has a shared extent.
$XFS_IO_PROG -d -c "pwrite -N -V 1 -S 0xff -b 64K 32K 64K" $SCRATCH_MNT/f3

# Check no data was written.
echo "File data after write attempt:"
od -A d -t x1 $SCRATCH_MNT/f3

# Create a file with a prealloc extent at eof and attempt to write to it, it
# should succeed.
echo
echo "Testing write against prealloc extent at eof"
$XFS_IO_PROG -f -s -c "pwrite -S 0xab 0 64K" \
	     -c "falloc -k 64K 64K" \
	     $SCRATCH_MNT/f4 | _filter_xfs_io

# Should succeed.
$XFS_IO_PROG -d -c "pwrite -N -V 1 -S 0xcd -b 64K 64K 64K" $SCRATCH_MNT/f4 \
    | _filter_xfs_io

# Check the file has the expected data.
echo "File after write:"
od -A d -t x1 $SCRATCH_MNT/f4

# Attempts to write to ranges that have a hole, should fail with -EAGAIN.
echo
echo "Testing writes against ranges with holes"
touch $SCRATCH_MNT/f5
$CHATTR_PROG +C $SCRATCH_MNT/f5
# 3 64Kb extents, with a 64K hole at offset 128K.
$XFS_IO_PROG -s -d -c "pwrite -S 0xab -b 64K 0 64K" \
	     -s -d -c "pwrite -S 0xcd -b 64K 64K 64K" \
	     -s -d -c "pwrite -S 0xef -b 64K 192K 64K" \
	     $SCRATCH_MNT/f5 | _filter_xfs_io

# Should fail, second half of the range maps to a hole.
$XFS_IO_PROG -d -c "pwrite -N -V 1 -S 0x11 -b 128K 64K 128K" $SCRATCH_MNT/f5

# Now try with a range that starts with a hole and ends with an extent, should
# fail as well.
$XFS_IO_PROG -c "fpunch 0 64K" \
	     -d -c "pwrite -N -V 1 -S 0x22 -b 128K 0 128K" \
	     $SCRATCH_MNT/f5

# Check no data was written.
echo "File data after write attempt:"
od -A d -t x1 $SCRATCH_MNT/f5

status=0
exit