tests/generic/743

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2024 Oracle.  All Rights Reserved.
#
# FS QA Test No. 743
#
# This is a regression test for a kernel hang that I saw when creating a memory
# mapping, injecting EIO errors on the block device, and invoking
# MADV_POPULATE_READ on the mapping to fault in the pages.
#
. ./common/preamble
_begin_fstest auto rw eio mmap

# Override the default cleanup function.
_cleanup()
{
	cd /
	rm -f $tmp.*
	_dmerror_unmount
	_dmerror_cleanup
}

# Import common functions.
. ./common/filter
. ./common/dmerror

_fixed_by_kernel_commit 631426ba1d45 \
	"mm/madvise: make MADV_POPULATE_(READ|WRITE) handle VM_FAULT_RETRY properly"


# Modify as appropriate.
_require_xfs_io_command madvise -R
_require_scratch
_require_dm_target error
_require_command "$TIMEOUT_PROG" "timeout"

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

filesz=2m

# Create a file that we'll read, then cycle mount to zap pagecache
_dmerror_mount
$XFS_IO_PROG -f -c "pwrite -S 0x58 0 $filesz" "$SCRATCH_MNT/a" >> $seqres.full
_dmerror_unmount
_dmerror_mount

# Try to read the file data in a regular fashion just to prove that it works.
echo read with no errors
$TIMEOUT_PROG -s KILL 10s $XFS_IO_PROG -c "mmap -r 0 $filesz" -c "madvise -R 0 $filesz" "$SCRATCH_MNT/a"
_dmerror_unmount
_dmerror_mount

# Load file metadata and induce EIO errors on read.  Try to provoke the kernel;
# kill the process after 10s so we can clean up.
stat "$SCRATCH_MNT/a" >> $seqres.full
echo read with IO errors
_dmerror_load_error_table
$TIMEOUT_PROG -s KILL 10s $XFS_IO_PROG -c "mmap -r 0 $filesz" -c "madvise -R 0 $filesz" "$SCRATCH_MNT/a" |& \
		_filter_flakey_EIO "madvise: Bad address"
_dmerror_load_working_table

# success, all done
status=0
exit