[PATCH 2/2] nfsrahead: quieten misleading error for non-NFS block devices

[Aaron Tomlin <atomlin@atomlin.com>]

When get_device_info() evaluates a physical block device via the
fast-path rejection logic, it deliberately returns -ENODEV.

Previously, main() handled this by logging a D_GENERAL error ("unable to
find device"). Because udev invokes nfsrahead for all block devices
across the system, this results in misleading journal spam for devices
that were intentionally skipped, rather than genuinely missing.

Update the error handling logic in main() to explicitly catch the
-ENODEV return code. When encountered, log a more accurate "skipping
non-NFS device" message at the D_ALL debugging level. This prevents
unnecessary journal noise whilst maintaining the existing behaviour of
returning the errno exit status.

Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
---
 tools/nfsrahead/main.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/nfsrahead/main.c b/tools/nfsrahead/main.c
index 33487f37..86c7fcc6 100644
--- a/tools/nfsrahead/main.c
+++ b/tools/nfsrahead/main.c
@@ -218,7 +218,11 @@ int main(int argc, char **argv)
 	if ((argc - optind) != 1)
 		xlog_err("expected the device number of a BDI; is udev ok?");
 
-	if ((ret = get_device_info(argv[optind], &device)) != 0 || device.fstype == NULL) {
+	ret = get_device_info(argv[optind], &device);
+	if (ret == -ENODEV) {
+		xlog(D_ALL, "skipping non-NFS device %s\n", argv[optind]);
+		goto out;
+	} else if (ret != 0 || device.fstype == NULL) {
 		xlog(D_GENERAL, "unable to find device %s\n", argv[optind]);
 		goto out;
 	}
-- 
2.51.0