Re: [PATCH] generic/{175,297,298}: fix use of uninitialized var

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

On Sat, Aug 12, 2023 at 06:15:00PM +0300, Amir Goldstein wrote:
> Not sure how those tests pass in regression tests.
> Probably truncate silently fails and is not critical to the test.
> 
> in kdevops I get errors like:
> /data/fstests-install/xfstests/tests/generic/298: line 45: /dev/loop12):
>            syntax error: operand expected (error token is "/dev/loop12)")
> 
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> ---
>  tests/generic/175 | 2 +-
>  tests/generic/297 | 2 +-
>  tests/generic/298 | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/tests/generic/175 b/tests/generic/175
> index 07af2199..14825a39 100755
> --- a/tests/generic/175
> +++ b/tests/generic/175
> @@ -33,7 +33,7 @@ _pwrite_byte 0x61 0 $blksz "$testdir/file1" >> "$seqres.full"
>  
>  fnr=19
>  echo "Create extents"
> -truncate -s $(( (2 ** i) * blksz)) "$testdir/file1"
> +truncate -s $(( (2 ** (fnr + 1)) * blksz)) "$testdir/file1"
>  for i in $(seq 0 $fnr); do

Hmm.  Frankly I don't remember why I put those truncate calls in there.
Does the test still work if you remove them entirely?  AFAICT the test
writes a single block's worth of data to the file, then truncates the
file size to one block.  Which I think is pointless.

>  	echo " ++ Reflink size $i, $((2 ** i)) blocks" >> "$seqres.full"
>  	n=$(( (2 ** i) * blksz))
> diff --git a/tests/generic/297 b/tests/generic/297
> index 6bdc3e1c..1fc48671 100755
> --- a/tests/generic/297
> +++ b/tests/generic/297
> @@ -42,7 +42,7 @@ _pwrite_byte 0x61 0 $blksz $testdir/file1 >> $seqres.full
>  fnr=26		# 2^26 reflink extents should be enough to find a slow op?
>  timeout=8	# guarantee a good long run...
>  echo "Find a reflink size that takes a long time"
> -truncate -s $(( (2 ** i) * blksz)) $testdir/file1
> +truncate -s $(( (2 ** (fnr + 1)) * blksz)) $testdir/file1
>  for i in $(seq 0 $fnr); do
>  	echo " ++ Reflink size $i, $((2 ** i)) blocks" >> $seqres.full
>  	n=$(( (2 ** i) * blksz))

The loop control logic could be converted to:

echo "Find a reflink size that takes a long time"
deadline="$(( $(date +%s) + timeout ))"
for ((i = 0, now = $(date +%s); i < fnr && now < deadline; i++, now = $(date +%s))); do
	echo " ++ Reflink size $i, $((2 ** i)) blocks" >> $seqres.full
	n=$(( (2 ** i) * blksz))
	$XFS_IO_PROG -f -c "reflink $testdir/file1 0 $n $n" $testdir/file1 >> $seqres.full 2>&1
done

(also in 298)

--D

> diff --git a/tests/generic/298 b/tests/generic/298
> index 95d4c02b..2e917a87 100755
> --- a/tests/generic/298
> +++ b/tests/generic/298
> @@ -42,7 +42,7 @@ _pwrite_byte 0x61 0 $blksz $testdir/file1 >> $seqres.full
>  fnr=26		# 2^26 reflink extents should be enough to find a slow op?
>  timeout=8	# guarantee a good long run...
>  echo "Find a reflink size that takes a long time"
> -truncate -s $(( (2 ** i) * blksz)) $testdir/file1
> +truncate -s $(( (2 ** (fnr + 1)) * blksz)) $testdir/file1
>  for i in $(seq 0 $fnr); do
>  	echo " ++ Reflink size $i, $((2 ** i)) blocks" >> $seqres.full
>  	n=$(( (2 ** i) * blksz))
> -- 
> 2.34.1
>