On 2017-11-09 15:11, Eric Blake wrote: > 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"
Although ":>" looks funny, I guess I'd rather stay with the echo... Yes, it may look stupid to you, but I would have to look up what exactly that will do, whereas the echo is clear. And in the end, both work equally fine. >> $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") Oh, nice! Will do, thanks. Max
signature.asc
Description: OpenPGP digital signature
