btrfs-progs: move test_issubvolume() to utils.c

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/utils.c b/utils.c
index 09962f8e..6dea54f2 100644
--- a/utils.c
+++ b/utils.c
@@ -3151,3 +3151,30 @@ int test_issubvolname(const char *name)
 	return name[0] != '\0' && !strchr(name, '/') &&
 		strcmp(name, ".") && strcmp(name, "..");
 }
+
+/*
+ * Test if path is a subvolume
+ * Returns:
+ *   0 - path exists but it is not a subvolume
+ *   1 - path exists and it is  a subvolume
+ * < 0 - error
+ */
+int test_issubvolume(const char *path)
+{
+	struct stat	st;
+	struct statfs stfs;
+	int		res;
+
+	res = stat(path, &st);
+	if (res < 0)
+		return -errno;
+
+	if (st.st_ino != BTRFS_FIRST_FREE_OBJECTID || !S_ISDIR(st.st_mode))
+		return 0;
+
+	res = statfs(path, &stfs);
+	if (res < 0)
+		return -errno;
+
+	return (int)stfs.f_type == BTRFS_SUPER_MAGIC;
+}