On 11/08/2017 07:38 PM, Max Reitz wrote: > 083 has (at least) two issues:
I think I hit one of them intermittently yesterday; thanks for
diagnosing these (and like you say, there may be more lurking, but we'll
whack them separately if we can reproduce and identify them).
>
> 1. By launching the nbd-fault-injector in background, it may not be
> scheduled until the first grep on its output file is executed.
> However, until then, that file may not have been created yet -- so it
> either does not exist yet (thus making the grep emit an error), or it
> does exist but contains stale data (thus making the rest of the test
> case work connect to a wrong address).
> Fix this by explicitly overwriting the output file before executing
> nbd-fault-injector.
>
> 2. The nbd-fault-injector prints things other than "Listening on...".
> It also prints a "Closing connection" message from time to time. We
> currently invoke sed on the whole file in the hope of it only
> containing the "Listening on..." line yet. That hope is sometimes
> shattered by the brutal reality of race conditions, so invoke grep
> before sed.
Invoking 'grep | sed' is almost always a waste of a process; sed can do
the job alone.
>
> Signed-off-by: Max Reitz <mre...@redhat.com>
> ---
> tests/qemu-iotests/083 | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tests/qemu-iotests/083 b/tests/qemu-iotests/083
> index 0306f112da..2f6444eeb9 100755
> --- a/tests/qemu-iotests/083
> +++ b/tests/qemu-iotests/083
> @@ -86,6 +86,7 @@ EOF
>
> rm -f "$TEST_DIR/nbd.sock"
>
> + echo > "$TEST_DIR/nbd-fault-injector.out"
This makes the file contain a blank line. Would it be any better as a
truly empty file, as in:
: > "$TEST_DIR/nbd-fault-injector.out"
> $PYTHON nbd-fault-injector.py $extra_args "$nbd_addr"
> "$TEST_DIR/nbd-fault-injector.conf" >"$TEST_DIR/nbd-fault-injector.out" 2>&1 &
>
> # Wait for server to be ready
> @@ -94,7 +95,7 @@ EOF
> done
>
> # Extract the final address (port number has now been assigned in tcp
> case)
> - nbd_addr=$(sed 's/Listening on \(.*\)$/\1/'
> "$TEST_DIR/nbd-fault-injector.out")
> + nbd_addr=$(grep 'Listening on ' "$TEST_DIR/nbd-fault-injector.out" |
> sed 's/Listening on \(.*\)$/\1/')
Fixing TAB damage while at it - nice.
Here's how to do it using just sed, and with less typing:
nbd_addr=$(sed -n 's/^Listening on //p' \
"$TEST_DIR/nbd-fault-injector.out")
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
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