Re: What happens to pages that failed to be written to disk?

[Martin Jambor <jamborm@gmail.com>]

Hi and thanks for all answers.

On 7/28/05, Andrew Morton <akpm@osdl.org> wrote:
> > Is the error
> > somehow signalled to anyone?
> 
> Yes, it's propagated into the file's address_space for a later
> fsync()/fdatasync()/msync() to detect.

I see, so a subsequent sync, fsync or umount fail with an error even
when the writing that failed was not initiated because of them?

> > Do filesystems try to relocate the data
> > from bad blocks of the device?
> 
> Nope.  Disks will do that internally.  If a disk gets a write I/O error
> it's generally dead.

I am not interested in what happens in HW, I strive to write a filesystem :-) 
Anyway, I see that a write error probably does not happen because of
bad blocks anyway but because something even worse happened and
therefore there is no point in it even though our filesystem would be
able to relocate stuff fairly easily. Am I right?

Thanks again,

Martin