Re: [Question] Does the kernel ignore errors writng to disk?

Alan Cox
2005-04-28T22:45:53Z

On Iau, 2005-04-28 at 19:14, Bryan Henderson wrote:
> Probably the most common way to get the simple but slow write function
> where the write() call actually writes to stable storage, and fails if it
> can't, is the O_SYNC open flag.

O_SYNC doesn't work completely on several file systems and only on the
latest kernels with some of the common ones.

> But even that, in some versions of Linux, can miss write errors. It's not
> easy for Linux to catch them because the code that sees the I/O fail
> doesn't know if it's part of some synchronous procedure where the user
> will eventually find out about the error or the more common case where the
> application has optimistically walked away and nothing can be done but
> write off the loss.

Or because the error is reported out of order and there are ordering
guarantees in the fs. SCSI is ok here other controllers are not always
right.