Re: [PATCH 07/11] xfs: Check for extent overflow when writing to unwritten extent

Chandan Babu R
2020-11-17T15:15:55Z

On Saturday 14 November 2020 6:09:18 AM IST Darrick J. Wong wrote:
> On Fri, Nov 13, 2020 at 04:56:59PM +0530, Chandan Babu R wrote:
> > This test verifies that XFS does not cause inode fork's extent count to
> > overflow when writing to an unwritten extent.
> >
> > Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
> > ---
> > tests/xfs/527 | 125 ++++++++++++++++++++++++++++++++++++++++++++++
> > tests/xfs/527.out | 13 +++++
> > tests/xfs/group | 1 +
> > 3 files changed, 139 insertions(+)
> > create mode 100755 tests/xfs/527
> > create mode 100644 tests/xfs/527.out
> >
> > diff --git a/tests/xfs/527 b/tests/xfs/527
> > new file mode 100755
> > index 00000000..f040aee4
> > --- /dev/null
> > +++ b/tests/xfs/527
> > @@ -0,0 +1,125 @@
> > +#! /bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (c) 2020 Chandan Babu R. All Rights Reserved.
> > +#
> > +# FS QA Test 527
> > +#
> > +# Verify that XFS does not cause inode fork's extent count to overflow when
> > +# writing to an unwritten extent.
> > +seq=`basename $0`
> > +seqres=$RESULT_DIR/$seq
> > +echo "QA output created by $seq"
> > +
> > +here=`pwd`
> > +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/inject
> > +
> > +# remove previous $seqres.full before test
> > +rm -f $seqres.full
> > +
> > +# real QA test starts here
> > +
> > +_supported_fs xfs
> > +_require_scratch
> > +_require_xfs_debug
> > +_require_xfs_io_command "falloc"
> > +_require_xfs_io_error_injection "reduce_max_iextents"
> > +
> > +buffered_write_to_unwritten_extent()
>
> This is nearly the same as the directio write test; could you combine
> them into a single function so we have fewer functions to maintain?

Ok. I will do that.

>
> --D
>
> > +{
> > + echo "* Buffered write to unwritten extent"
> > +
> > + echo "Format and mount fs"
> > + _scratch_mkfs_sized $((1024 * 1024 * 1024)) >> $seqres.full
> > + _scratch_mount >> $seqres.full
> > +
> > + bsize=$(_get_block_size $SCRATCH_MNT)
> > +
> > + testfile=${SCRATCH_MNT}/testfile
> > +
> > + nr_blks=15
> > +
> > + echo "Fallocate $nr_blks blocks"
> > + xfs_io -f -c "falloc 0 $((nr_blks * bsize))" $testfile >> $seqres.full
> > +
> > + echo "Inject reduce_max_iextents error tag"
> > + xfs_io -x -c "inject reduce_max_iextents" $SCRATCH_MNT
> > +
> > + echo "Buffered write to every other block of fallocated space"
> > + for i in $(seq 1 2 $((nr_blks - 1))); do
> > + xfs_io -f -c "pwrite $((i * bsize)) $bsize" -c fsync $testfile \
> > + >> $seqres.full 2>&1
> > + [[ $? != 0 ]] && break
> > + done
> > +
> > + testino=$(stat -c "%i" $testfile)
> > +
> > + _scratch_unmount >> $seqres.full
> > +
> > + echo "Verify \$testfile's extent count"
> > +
> > + nextents=$(_scratch_get_iext_count $testino data || \
> > + _fail "Unable to obtain inode fork's extent count")
> > + if (( $nextents > 10 )); then
> > + echo "Extent count overflow check failed: nextents = $nextents"
> > + fi
> > +}
> > +
> > +direct_write_to_unwritten_extent()
> > +{
> > + echo "* Direct I/O write to unwritten extent"
> > +
> > + echo "Format and mount fs"
> > + _scratch_mkfs_sized $((1024 * 1024 * 1024)) >> $seqres.full
> > + _scratch_mount >> $seqres.full
> > +
> > + bsize=$(_get_block_size $SCRATCH_MNT)
> > +
> > + testfile=${SCRATCH_MNT}/testfile
> > +
> > + nr_blks=15
> > +
> > + echo "Fallocate $nr_blks blocks"
> > + xfs_io -f -c "falloc 0 $((nr_blks * bsize))" $testfile >> $seqres.full
> > +
> > + echo "Inject reduce_max_iextents error tag"
> > + xfs_io -x -c "inject reduce_max_iextents" $SCRATCH_MNT
> > +
> > + echo "Direct I/O write to every other block of fallocated space"
> > + for i in $(seq 1 2 $((nr_blks - 1))); do
> > + xfs_io -f -d -c "pwrite $((i * bsize)) $bsize" $testfile \
> > + >> $seqres.full 2>&1
> > + [[ $? != 0 ]] && break
> > + done
> > +
> > + testino=$(stat -c "%i" $testfile)
> > +
> > + _scratch_unmount >> $seqres.full
> > +
> > + echo "Verify \$testfile's extent count"
> > +
> > + nextents=$(_scratch_get_iext_count $testino data || \
> > + _fail "Unable to obtain inode fork's extent count")
> > + if (( $nextents > 10 )); then
> > + echo "Extent count overflow check failed: nextents = $nextents"
> > + fi
> > +}
> > +
> > +buffered_write_to_unwritten_extent
> > +direct_write_to_unwritten_extent
> > +
> > +# success, all done
> > +status=0
> > +exit
> > diff --git a/tests/xfs/527.out b/tests/xfs/527.out
> > new file mode 100644
> > index 00000000..6aa5e9ed
> > --- /dev/null
> > +++ b/tests/xfs/527.out
> > @@ -0,0 +1,13 @@
> > +QA output created by 527
> > +* Buffered write to unwritten extent
> > +Format and mount fs
> > +Fallocate 15 blocks
> > +Inject reduce_max_iextents error tag
> > +Buffered write to every other block of fallocated space
> > +Verify $testfile's extent count
> > +* Direct I/O write to unwritten extent
> > +Format and mount fs
> > +Fallocate 15 blocks
> > +Inject reduce_max_iextents error tag
> > +Direct I/O write to every other block of fallocated space
> > +Verify $testfile's extent count
> > diff --git a/tests/xfs/group b/tests/xfs/group
> > index d089797b..627813fe 100644
> > --- a/tests/xfs/group
> > +++ b/tests/xfs/group
> > @@ -524,3 +524,4 @@
> > 524 auto quick punch zero insert collapse
> > 525 auto quick attr
> > 526 auto quick dir hardlink symlink
> > +527 auto quick
>

--
chandan