apfstests/tests/generic/485

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2018 Google, Inc.  All Rights Reserved.
#
# FS QA Test No. 485
#
# Regression test for:
#    349fa7d6e193 ("ext4: prevent right-shifting extents beyond EXT_MAX_BLOCKS")
#    7d83fb14258b ("xfs: prevent creating negative-sized file via INSERT_RANGE")
#
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"

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

_cleanup()
{
	cd /
	rm -f $testfile
}

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

# remove previous $seqres.full before test
rm -f $seqres.full

# real QA test starts here
_supported_fs generic
_supported_os Linux
_require_test
_require_math
_require_xfs_io_command "falloc" "-k"
_require_xfs_io_command "finsert"
_require_xfs_io_command "truncate"

# Get the maximum size of a file in $TEST_DIR (s_maxbytes).  On ext4 this will
# be UINT32_MAX * block_size, but other filesystems may allow up to LLONG_MAX.
get_max_file_size()
{
	local testfile=$TEST_DIR/maxfilesize.$seq
	local l=0
	local r=9223372036854775807 # LLONG_MAX

	rm -f $testfile
	while (( l < r )); do
		# Use _math() to avoid signed integer overflow.
		local m=$(_math "($l + $r + 1) / 2")
		if $XFS_IO_PROG -f -c "truncate $m" $testfile \
			|& grep -q 'File too large'
		then
			r=$(( m - 1 ))
		else
			l=$m
		fi
	done
	echo $l
}

block_size=$(_get_file_block_size $TEST_DIR)
max_file_size=$(get_max_file_size)
max_blocks=$((max_file_size / block_size))
testfile=$TEST_DIR/testfile.$seq

echo "# With KEEP_SIZE"
rm -f "$testfile"

# Add an extent at the beginning of the file.  With ext4, this is needed to
# reproduce the bug where the extents appear out of order later.
$XFS_IO_PROG -f -c "falloc 0 $((2 * block_size))" "$testfile"

# Add an extent just below s_maxbytes, without changing i_size (i.e. with -k).
# The out-of-order extents bug can't be reproduced if i_size is changed, because
# then the range insertion fails due to the new i_size being > s_maxbytes.
$XFS_IO_PROG -c "falloc -k $(( (max_blocks - 1) * $block_size )) $block_size" \
	"$testfile"

# Insert an extent at the beginning of the file.  With the ext4 bug, this caused
# the logical block number of the extent just below s_maxbytes to wrap around,
# causing the extents to get out of order, causing corruption detected by
# e2fsck.  With the fix, the range insertion fails with EINVAL.  Though, with
# xfs and f2fs the insertion succeeds, resulting in extents beyond s_maxbytes,
# but there is no wraparound -- which is arguably okay.  So we allow either
# behavior and just rely on fsck detecting if something went wrong.
$XFS_IO_PROG -c "finsert 0 $((2 * block_size))" "$testfile" &>>$seqres.full

# Also do the same test, but with changing i_size (i.e. without -k).  The
# insertion should fail with EFBIG.  This exposed an XFS bug where i_size + len
# underwent signed overflow, resulting in a negative-sized file.
echo "# Without KEEP_SIZE"
rm -f "$testfile"
$XFS_IO_PROG -f -c "falloc 0 $((2 * block_size))" "$testfile"
$XFS_IO_PROG -c "falloc $(( (max_blocks - 1) * $block_size )) $block_size" \
	"$testfile"
$XFS_IO_PROG -c "finsert 0 $((2 * block_size))" "$testfile"

status=0
exit