[PATCH ndctl 2/2] daxctl/device.c: Fix error propagation in do_xaction_device()

[Vishal Verma <vishal.l.verma@intel.com>]

The loop through the provided list of devices in do_xaction_device()
returns the status based on whatever the last device did. Since the
order of processing devices, especially in cases like the 'all' keyword,
can be effectively random, this can lead to the same command, and same
effects, exiting with a different error code based on device ordering.

This was noticed with flakiness in the daxctl-create.sh unit test. Its
'destroy-device all' command would either pass or fail based on the
order it tried to destroy devices in. (Recall that until now, destroying
a daxX.0 device would result in a failure).

Make this slightly more consistent by saving a failed status in
do_xaction_device if any iteration of the loop produces a failure.
Return this saved status instead of returning the status of the last
device processed.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
 daxctl/device.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/daxctl/device.c b/daxctl/device.c
index 83c61389..14d62148 100644
--- a/daxctl/device.c
+++ b/daxctl/device.c
@@ -1012,7 +1012,7 @@ static int do_xaction_device(const char *device, enum device_action action,
 	struct json_object *jdevs = NULL;
 	struct daxctl_region *region;
 	struct daxctl_dev *dev;
-	int rc = -ENXIO;
+	int rc = -ENXIO, saved_rc = 0;
 
 	*processed = 0;
 
@@ -1059,6 +1059,8 @@ static int do_xaction_device(const char *device, enum device_action action,
 				rc = -EINVAL;
 				break;
 			}
+			if (rc)
+				saved_rc = rc;
 		}
 	}
 
@@ -1070,7 +1072,7 @@ static int do_xaction_device(const char *device, enum device_action action,
 	if (jdevs)
 		util_display_json_array(stdout, jdevs, flags);
 
-	return rc;
+	return saved_rc;
 }
 
 int cmd_create_device(int argc, const char **argv, struct daxctl_ctx *ctx)

-- 
2.44.0