[LTP] [PATCH v3 2/3] lib/tst_device.c: check for BTRFS_SUPER_MAGIC instead of device major of 0

[Petr Vorel]

Hi Jeff,

> stat() may return a major number of 0 in st_dev for any number of
> pseudo file systems.  Check for the exact file system instead.  There
> should be no change in behavior with this patch.

LGTM, thank you!
Reviewed-by: Petr Vorel <pvorel@suse.cz>

FYI I'll apply very minor formatting fix before merge.

Kind regards,
Petr

+++ lib/tst_device.c
@@ -559,12 +559,10 @@ static void btrfs_get_uevent_path(char *tmp_path, char *uevent_path)
 
 	uevent_path[0] = '\0';
 
-	if (d) {
-		sprintf(uevent_path, "%s/%s/uevent",
-			bdev_path, d->d_name);
-	} else {
-		tst_brkm(TBROK | TERRNO, NULL, "No backing device found while looking in %s.", bdev_path);
-	}
+	if (d)
+		sprintf(uevent_path, "%s/%s/uevent", bdev_path, d->d_name);
+	else
+		tst_brkm(TBROK | TERRNO, NULL, "No backing device found while looking in %s", bdev_path);
 
 	if (SAFE_READDIR(NULL, dir))
 		tst_resm(TINFO, "Warning: used first of multiple backing device.");
@@ -600,7 +598,7 @@ void tst_find_backing_dev(const char *path, char *dev, size_t dev_size)
 	if (fsbuf.f_type == TST_BTRFS_MAGIC) {
 		btrfs_get_uevent_path(tmp_path, uevent_path);
 	} else if (dev_major == 0) {
-		tst_brkm(TBROK, NULL, "%s resides on an unsupported pseudo-file system.", path);
+		tst_brkm(TBROK, NULL, "%s resides on an unsupported pseudo-file system", path);
 	} else {
 		tst_resm(TINFO, "Use uevent strategy");
 		sprintf(uevent_path,