Re: [PATCH 6/6] tests: avoid spurious parallel failure due to temporary disk full

[Jim Meyering]

Jim Meyering wrote:

> From: Jim Meyering <address@hidden>
>
> Running the new fiemap-empty test uses 600MB of disk space via
> fallocate, and in so doing caused failure in unrelated tests that
> were running in parallel on a small file system.  Rather than
> simply running fallocate (which allocates the space, inducing
> disk full when it fails), skip the test if there is less than
> 800MB of free space, as computed via stat and awk.
> * tests/init.cfg (require_file_system_bytes_free_): New function.
> * tests/cp/fiemap-empty: Use it.
> ---
>  tests/cp/fiemap-empty |    7 +++++++
>  tests/init.cfg        |    8 ++++++++
>  2 files changed, 15 insertions(+), 0 deletions(-)
>
> diff --git a/tests/cp/fiemap-empty b/tests/cp/fiemap-empty
> index 203619a..42d816b 100755
> --- a/tests/cp/fiemap-empty
> +++ b/tests/cp/fiemap-empty
> @@ -31,6 +31,13 @@ fallocate -l 1 -n falloc.test ||
>    skip_test_ 'this file system lacks FALLOCATE support'
>  rm falloc.test
>
> +# Require more space than we'll actually use, so that
> +# tests run in parallel do not run out of space.
> +# Otherwise, with inadequate space, simply running the following
> +# fallocate command would induce a temporary disk-full condition,
> +# which would cause failure of unrelated tests run in parallel.
> +require_file_system_bytes_free_ 800000000
> +
>  fallocate -l 600000000 space.test ||
>    skip_test_ 'this test needs at least 600MB free space'
>
> diff --git a/tests/init.cfg b/tests/init.cfg
> index 0711455..49cc4ee 100644
> --- a/tests/init.cfg
> +++ b/tests/init.cfg
> @@ -151,6 +151,14 @@ require_built_()
>    test $skip_ = yes && skip_test_ "required program(s) not built"
>  }
>
> +require_file_system_bytes_free_()
> +{
> +  local req=$1
> +  local expr=$(stat -f --printf "($req + %S - 1) / %S <= %f" .)
> +  awk "BEGIN{ exit !($expr) }" \
> +    || skip_test_ "this test needs at least $req bytes of free space"

I realized that with awk we don't need the +%S-1,
since it does floating point arithmetic:

  local expr=$(stat -f --printf "$req / %S <= %f" .)