[PATCH 3/4] samples/vfs: check whether flag was raised

[Christian Brauner <brauner@kernel.org>]

For string options the kernel will raise the corresponding flag only if
the string isn't empty. So check for the flag.

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 samples/vfs/test-list-all-mounts.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/samples/vfs/test-list-all-mounts.c b/samples/vfs/test-list-all-mounts.c
index 1a02ea4593e3..ce272ded8a79 100644
--- a/samples/vfs/test-list-all-mounts.c
+++ b/samples/vfs/test-list-all-mounts.c
@@ -138,10 +138,11 @@ int main(int argc, char *argv[])
 			printf("mnt_id:\t\t%" PRIu64 "\nmnt_parent_id:\t%" PRIu64 "\nfs_type:\t%s\nmnt_root:\t%s\nmnt_point:\t%s\nmnt_opts:\t%s\n\n",
 			       (uint64_t)stmnt->mnt_id,
 			       (uint64_t)stmnt->mnt_parent_id,
-			       stmnt->str + stmnt->fs_type,
-			       stmnt->str + stmnt->mnt_root,
-			       stmnt->str + stmnt->mnt_point,
-			       stmnt->str + stmnt->mnt_opts);
+			       (stmnt->mask & STATMOUNT_FS_TYPE)   ? stmnt->str + stmnt->fs_type   : "",
+			       (stmnt->mask & STATMOUNT_MNT_ROOT)  ? stmnt->str + stmnt->mnt_root  : "",
+			       (stmnt->mask & STATMOUNT_MNT_POINT) ? stmnt->str + stmnt->mnt_point : "",
+			       (stmnt->mask & STATMOUNT_MNT_OPTS)  ? stmnt->str + stmnt->mnt_opts  : "");
+
 			free(stmnt);
 		}
 	}

-- 
2.47.2