---
title: vfs_isrdonly
framework: Kernel
role: symbol
role_heading: Function
platforms: [macOS 10.4+]
path: kernel/1523242-vfs_isrdonly
---

# vfs_isrdonly

Determine if a filesystem is mounted read-only.

## Declaration

```occ
int vfs_isrdonly(mount_t mp);
```

## Parameters

- `mp`: Mount to test.

## Return Value

Return Value Nonzero if filesystem is mounted read-only, else 0.