Function dfs_devfs_read

components/dfs/dfs_v2/filesystems/devfs/devfs.c:140–174

}

static ssize_t dfs_devfs_read(struct dfs_file *file, void *buf, size_t count, off_t *pos)
{
    ssize_t ret = -RT_EIO;
    rt_device_t device;

    RT_ASSERT(file != RT_NULL);

    if (file->vnode && file->vnode->data)
    {
        /* get device handler */
        device = (rt_device_t)file->vnode->data;

#ifdef RT_USING_POSIX_DEVIO
        if (device->fops && device->fops->read)
        {
            ret = device->fops->read(file, buf, count, pos);
        }
        else
#else
        if (device->ops)
#endif /* RT_USING_POSIX_DEVIO */
        {
            rt_ubase_t shift = _get_unit_shift(device);

            ret = rt_device_read(device, *pos, buf, count >> shift);
            if (ret > 0)
            {
                ret <<= shift;
                *pos += ret;
            }
        }
    }

    return ret;
}

static ssize_t dfs_devfs_write(struct dfs_file *file, const void *buf, size_t count, off_t *pos)
{