#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2022 Oracle.  All Rights Reserved.
#
# FS QA Test No. 107
#
# Regression test for commit:
#
# 983d8e60f508 ("xfs: map unwritten blocks in XFS_IOC_{ALLOC,FREE}SP just like fallocate")
#
. ./common/preamble
_begin_fstest auto quick prealloc

# Import common functions.
. ./common/filter

# real QA test starts here

# Modify as appropriate.
_supported_fs xfs
_require_test
_require_scratch
_require_test_program allocstale

size_mb=32
# Write a known pattern to the disk so that we can detect stale disk blocks
# being mapped into the file.  In the test author's experience, the bug will
# reproduce within the first 500KB's worth of ALLOCSP calls, so running up
# to 16MB should suffice.
$XFS_IO_PROG -d -c "pwrite -S 0x58 -b 8m 0 ${size_mb}m" $SCRATCH_DEV > $seqres.full
MKFS_OPTIONS="-K $MKFS_OPTIONS" _scratch_mkfs_sized $((size_mb * 1048576)) >> $seqres.full

_scratch_mount

# Force the file to be created on the data device, which we pre-initialized
# with a known pattern.  The bug exists in the generic bmap code, so the choice
# of backing device does not matter, and ignoring the rt device gets us out of
# needing to detect things like rt extent size.
_xfs_force_bdev data $SCRATCH_MNT
testfile=$SCRATCH_MNT/a

# Allow the test program to expand the file to consume half the free space.
blksz=$(_get_file_block_size $SCRATCH_MNT)
iterations=$(( (size_mb / 2) * 1048576 / blksz))
echo "Setting up $iterations runs for block size $blksz" >> $seqres.full

# Run reproducer program and dump file contents if we see stale data.  Full
# details are in the source for the C program, but in a nutshell we run ALLOCSP
# one block at a time to see if it'll give us blocks full of 'X'es.
$here/src/allocstale $testfile $iterations
res=$?
test $res -eq 2 && od -tx1 -Ad -c $testfile

# success, all done
echo Silence is golden
status=0
exit