将文件从 UBI 文件系统中的源复制到目标

Question

我想将文件从源复制到目标。但如果目标文件夹大小与源文件相比较小。它不会写入失败，总是返回成功，并且我仅在 UBI 文件系统中观察到这种行为。

while ((size = fread(buffer, 1, BUFSIZ, source)) > 0)
{
    size_t size_2 = fwrite(buffer, 1, size, destination);
    if (size_2 != size)
    {
        retval = -1;
        break;
    }
}

UBIFS支持回写，其中文件更改被缓存并稍后写入闪存。任何人都知道如何验证其写入状态。

Answer 1

您可以使用fsync来验证回写状态。

引用以下来源:

transfers ("flushes") all modified in-core data of ... the file referred to by the file descriptor fd to the disk device (or other permanent storage device) so that all changed information can be retrieved even if the system crashes or is rebooted. This includes writing through or flushing a disk cache if present

http://man7.org/linux/man-pages/man2/fdatasync.2.html