safe_mount: safe_umount: print debug info about the operation

Make the source and the target to mount/umount visible. It's
good for debugging.

Suggested-by: Martin Doucha <mdoucha@suse.cz>
Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
Reviewed-by: Li Wang <liwang@redhat.com>

Author: Murphy Zhou

lib/safe_macros.c

@@ -898,7 +898,16 @@ int safe_mount(const char *file, const int lineno, void (*cleanup_fn)(void),
 	       const void *data)
 {
 	int rval = -1;
+	char mpath[PATH_MAX];
 
+	if (realpath(target, mpath)) {
+		tst_resm_(file, lineno, TINFO,
+			"Mounting %s to %s fstyp=%s flags=%lx",
+			source, mpath, filesystemtype, mountflags);
+	} else {
+		tst_brkm_(file, lineno, TBROK | TERRNO, cleanup_fn,
+			"Cannot resolve the absolute path of %s", target);
+	}
 	/*
 	 * Don't try using the kernel's NTFS driver when mounting NTFS, since
 	 * the kernel's NTFS driver doesn't have proper write support.
@@ -948,6 +957,14 @@ int safe_umount(const char *file, const int lineno, void (*cleanup_fn)(void),
 		const char *target)
 {
 	int rval;
+	char mpath[PATH_MAX];
+
+	if (realpath(target, mpath)) {
+		tst_resm_(file, lineno, TINFO, "Umounting %s", mpath);
+	} else {
+		tst_brkm_(file, lineno, TBROK | TERRNO, cleanup_fn,
+			"Cannot resolve the absolute path of %s", target);
+	}
 
 	rval = tst_umount(target);