From f176436b697d0f865eb8f4d788140766780c1868 Mon Sep 17 00:00:00 2001
From: Jim Harris <james.r.harris@intel.com>
Date: Fri, 3 Nov 2017 11:22:05 -0700
Subject: [PATCH] test/bdev: wait for nbd device to become ready

Previously, we were waiting to find the target bdev as
registered before proceeding with nbd operations.  But
there can be a delay between when the bdev is registered
and when the nbd device becomes ready for block I/O
operations.  This delay has recently become longer as
lvol now performs I/O on registered bdevs to check for
an existing logical volume store.

So instead, check for the existence of the nbd device
in /proc/partitions output.

While here, also fix a bug in the nbd.c code - it needs
to wait for the poller to be unregistered before calling
spdk_nbd_stop().  Normally I would fix this in a separate
patch but because these issues are causing a lot of
failures in the test pool, I'm expediting this by putting
both fixes in one patch (so we can avoid a bunch of
re-runs).

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: Ia297337338f7eeee9b4c56b80e941d373c1a965d

Reviewed-on: https://review.gerrithub.io/385687
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
---
 scripts/autotest_common.sh | 34 ++++++++++++++++++----------------
 test/lib/bdev/nbd/nbd.c    | 12 ++++++++++--
 2 files changed, 28 insertions(+), 18 deletions(-)

diff --git a/scripts/autotest_common.sh b/scripts/autotest_common.sh
index 028fd9d790..4af7f9be7f 100755
--- a/scripts/autotest_common.sh
+++ b/scripts/autotest_common.sh
@@ -202,12 +202,11 @@ function waitforlisten() {
 	set -x
 }
 
-function waitforbdev() {
-	bdev_name=$1
-	rpc_py=$2
+function waitfornbd() {
+	nbd_name=$1
 
-	for ((i=1; i<=10; i++)); do
-		if $rpc_py get_bdevs -b "$bdev_name" &>/dev/null; then
+	for ((i=1; i<=20; i++)); do
+		if grep -q -w $nbd_name /proc/partitions; then
 			return 0
 		else
 			sleep 0.1
@@ -326,6 +325,10 @@ function part_dev_by_gpt () {
 			return 1
 		fi
 
+		if [ ! -e /dev/nbd0 ]; then
+			return 1
+		fi
+
 		if [ -z "$operation" ]; then
 			operation="create"
 		fi
@@ -339,19 +342,18 @@ function part_dev_by_gpt () {
 		nbd_pid=$!
 		echo "Process nbd pid: $nbd_pid"
 		waitforlisten $nbd_pid 5260
-		waitforbdev $devname "python $rootdir/scripts/rpc.py"
+		waitfornbd nbd0
 
-		if [ -e /dev/nbd0 ]; then
-			if [ "$operation" = create ]; then
-				parted -s /dev/nbd0 mklabel gpt mkpart first '0%' '50%' mkpart second '50%' '100%'
-				# change the GUID to SPDK GUID value
-				sgdisk -t 1:$SPDK_GPT_GUID /dev/nbd0
-				sgdisk -t 2:$SPDK_GPT_GUID /dev/nbd0
-			elif [ "$operation" = reset ]; then
-				# clear the partition table
-				dd if=/dev/zero of=/dev/nbd0 bs=4096 count=8 oflag=direct
-			fi
+		if [ "$operation" = create ]; then
+			parted -s /dev/nbd0 mklabel gpt mkpart first '0%' '50%' mkpart second '50%' '100%'
+			# change the GUID to SPDK GUID value
+			sgdisk -t 1:$SPDK_GPT_GUID /dev/nbd0
+			sgdisk -t 2:$SPDK_GPT_GUID /dev/nbd0
+		elif [ "$operation" = reset ]; then
+			# clear the partition table
+			dd if=/dev/zero of=/dev/nbd0 bs=4096 count=8 oflag=direct
 		fi
+
 		killprocess $nbd_pid
 		rm -f ${conf}.gpt
 	fi
diff --git a/test/lib/bdev/nbd/nbd.c b/test/lib/bdev/nbd/nbd.c
index 730819b4b4..3b67812f95 100644
--- a/test/lib/bdev/nbd/nbd.c
+++ b/test/lib/bdev/nbd/nbd.c
@@ -50,13 +50,21 @@ static char *g_nbd_name = "/dev/nbd0";
 #include "../common.c"
 
 static void
-nbd_shutdown(void)
+nbd_stop(void *arg1, void *arg2)
 {
-	spdk_poller_unregister(&g_nbd_poller, NULL);
 	spdk_nbd_stop(g_nbd_disk);
 	spdk_app_stop(0);
 }
 
+static void
+nbd_shutdown(void)
+{
+	struct spdk_event *stop_event;
+
+	stop_event = spdk_event_allocate(spdk_env_get_current_core(), nbd_stop, NULL, NULL);
+	spdk_poller_unregister(&g_nbd_poller, stop_event);
+}
+
 static void
 nbd_poll(void *arg)
 {