[PATCH blktests v2 2/5] nvme/rc: filter out errors from cat when reading files

[Daniel Wagner]

When running the tests with FC as transport and the udev auto connect
enabled, discovery controllers are created and destroyed while the tests
are running. This races with the cleanup code and also the
_find_nvme_dev() which iterates over all device entries and tries to
read the connect of transport and subsysnqn sysfs attributes. Since
these steps are not locked in anyway, the resources can go away in
between.

Thus filter out 'cat' reporting non existing subsysnqn or transport
attributes. The tests will still fail if they can't find the device etc.
But without filtering these errors out the tests fail randomly.

Signed-off-by: Daniel Wagner <dwagner at suse.de>
---
 tests/nvme/rc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/nvme/rc b/tests/nvme/rc
index e0461f1cd53a..9cc83afe0668 100644
--- a/tests/nvme/rc
+++ b/tests/nvme/rc
@@ -350,7 +350,7 @@ _cleanup_nvmet() {
 
 	for dev in /sys/class/nvme/nvme*; do
 		dev="$(basename "$dev")"
-		transport="$(cat "/sys/class/nvme/${dev}/transport")"
+		transport="$(cat "/sys/class/nvme/${dev}/transport" 2>/dev/null)"
 		if [[ "$transport" == "${nvme_trtype}" ]]; then
 			echo "WARNING: Test did not clean up ${nvme_trtype} device: ${dev}"
 			_nvme_disconnect_ctrl "${dev}"
@@ -840,7 +840,7 @@ _find_nvme_dev() {
 	for dev in /sys/class/nvme/nvme*; do
 		[ -e "$dev" ] || continue
 		dev="$(basename "$dev")"
-		subsysnqn="$(cat "/sys/class/nvme/${dev}/subsysnqn")"
+		subsysnqn="$(cat "/sys/class/nvme/${dev}/subsysnqn" 2>/dev/null)"
 		if [[ "$subsysnqn" == "$subsys" ]]; then
 			echo "$dev"
 		fi
-- 
2.43.0