On Thu, Jan 06, 2022 at 12:19:05AM +0800, Zorro Lang wrote:
> On Mon, Jan 03, 2022 at 06:04:17PM -0800, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@xxxxxxxxxx>
> >
> > This test checks that speculative file preallocations are transferred to
> > threads writing other files when space is low. Since we have background
> > threads to clear those preallocations, it's possible that the test
> > program might not get a speculative preallocation on the first try.
> >
> > This problem has become more pronounced since the introduction of
> > background inode inactivation since userspace no longer has direct
> > control over the timing of file blocks being released from unlinked
> > files. As a result, the author has seen an increase in sporadic
> > warnings from this test about speculative preallocations not appearing.
> >
> > Therefore, modify the function to try up to five times to create the
> > speculative preallocation before emitting warnings that then cause
> > golden output failures.
> >
> > Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> > ---
> > tests/xfs/014 | 41 +++++++++++++++++++++++++----------------
> > 1 file changed, 25 insertions(+), 16 deletions(-)
> >
> > diff --git a/tests/xfs/014 b/tests/xfs/014
> > index a605b359..1f0ebac3 100755
> > --- a/tests/xfs/014
> > +++ b/tests/xfs/014
> > @@ -33,27 +33,36 @@ _cleanup()
> > # failure.
> > _spec_prealloc_file()
> > {
> > - file=$1
> > + local file=$1
> > + local prealloc_size=0
> > + local i=0
> >
> > - rm -f $file
> > + # Now that we have background garbage collection processes that can be
> > + # triggered by low space/quota conditions, it's possible that we won't
> > + # succeed in creating a speculative preallocation on the first try.
> > + for ((tries = 0; tries < 5 && prealloc_size == 0; tries++)); do
> > + rm -f $file
> >
> > - # a few file extending open-write-close cycles should be enough to
> > - # trigger the fs to retain preallocation. write 256k in 32k intervals to
> > - # be sure
> > - for i in $(seq 0 32768 262144); do
> > - $XFS_IO_PROG -f -c "pwrite $i 32k" $file >> $seqres.full
> > + # a few file extending open-write-close cycles should be enough
> > + # to trigger the fs to retain preallocation. write 256k in 32k
> > + # intervals to be sure
> > + for i in $(seq 0 32768 262144); do
> > + $XFS_IO_PROG -f -c "pwrite $i 32k" $file >> $seqres.full
> > + done
> > +
> > + # write a 4k aligned amount of data to keep the calculations
> > + # simple
> > + $XFS_IO_PROG -c "pwrite 0 128m" $file >> $seqres.full
> > +
> > + size=`_get_filesize $file`
> > + blocks=`stat -c "%b" $file`
> > + blocksize=`stat -c "%B" $file`
> > +
> > + prealloc_size=$((blocks * blocksize - size))
>
> So we only try same pwrite operations 5 times, and only check the prealloc_size after 5
> times done? Should we break from this loop once prealloc_size > 0?
The second clause of the for loop tests for that, does it not?
--D
>
> Thanks,
> Zorro
>
> > done
> >
> > - # write a 4k aligned amount of data to keep the calculations simple
> > - $XFS_IO_PROG -c "pwrite 0 128m" $file >> $seqres.full
> > -
> > - size=`_get_filesize $file`
> > - blocks=`stat -c "%b" $file`
> > - blocksize=`stat -c "%B" $file`
> > -
> > - prealloc_size=$((blocks * blocksize - size))
> > if [ $prealloc_size -eq 0 ]; then
> > - echo "Warning: No speculative preallocation for $file." \
> > + echo "Warning: No speculative preallocation for $file after $tries iterations." \
> > "Check use of the allocsize= mount option."
> > fi
> >
> >
>
