Re: [PATCH 4/4] generic: test MADV_POPULATE_READ with IO errors

["Darrick J. Wong" <djwong@kernel.org>]

On Sat, Mar 30, 2024 at 03:12:00PM +0800, Zorro Lang wrote:
> On Tue, Mar 26, 2024 at 07:43:41PM -0700, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@kernel.org>
> > 
> > This is a regression test for "mm/madvise: make
> > MADV_POPULATE_(READ|WRITE) handle VM_FAULT_RETRY properly".
> > 
> > Cc: David Hildenbrand <david@redhat.com>
> > Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> > Reviewed-by: Christoph Hellwig <hch@lst.de>
> > ---
> >  tests/generic/1835     |   65 ++++++++++++++++++++++++++++++++++++++++++++++++
> >  tests/generic/1835.out |    4 +++
> >  2 files changed, 69 insertions(+)
> >  create mode 100755 tests/generic/1835
> >  create mode 100644 tests/generic/1835.out
> > 
> > 
> > diff --git a/tests/generic/1835 b/tests/generic/1835
> > new file mode 100755
> > index 0000000000..07479ab712
> > --- /dev/null
> > +++ b/tests/generic/1835
> > @@ -0,0 +1,65 @@
> > +#! /bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (c) 2024 Oracle.  All Rights Reserved.
> > +#
> > +# FS QA Test 1835
> > +#
> > +# 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
> 
> > +
> > +# Override the default cleanup function.
> > +_cleanup()
> > +{
> > +	cd /
> > +	rm -f $tmp.*
> > +	_dmerror_unmount
> > +	_dmerror_cleanup
> > +}
> > +
> > +# Import common functions.
> > +. ./common/dmerror
> > +
> > +_fixed_by_kernel_commit XXXXXXXXXXXX \
> > +	"mm/madvise: make MADV_POPULATE_(READ|WRITE) handle VM_FAULT_RETRY properly"
> > +
> > +# real QA test starts here
> > +
> > +# Modify as appropriate.
> > +_supported_fs generic
> > +_require_xfs_io_command madvise -R
> > +_require_scratch
> > +_require_dm_target error
> > +_require_command "$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 -s KILL 10s $XFS_IO_PROG -c "mmap -r 0 $filesz" -c "madvise -R 0 $filesz" "$SCRATCH_MNT/a"
> 
> timeout -> $TIMEOUT_PROG
> 
> Others looks good to me, if there's not more review points, I'll merge this
> patch with above changes, after testing done.

Ok.  I don't have any further changes to make to this test, other than
the XXXXX above whenever the fixes get merged.

--D

> Reviewed-by: Zorro Lang <zlang@redhat.com>
> 
> Thanks,
> Zorro
> 
> > +_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 -s KILL 10s $XFS_IO_PROG -c "mmap -r 0 $filesz" -c "madvise -R 0 $filesz" "$SCRATCH_MNT/a"
> > +_dmerror_load_working_table
> > +
> > +# success, all done
> > +status=0
> > +exit
> > diff --git a/tests/generic/1835.out b/tests/generic/1835.out
> > new file mode 100644
> > index 0000000000..1b03586e8c
> > --- /dev/null
> > +++ b/tests/generic/1835.out
> > @@ -0,0 +1,4 @@
> > +QA output created by 1835
> > +read with no errors
> > +read with IO errors
> > +madvise: Bad address
> > 
> 
>