On Wed, Nov 28, 2018 at 06:51:59PM +0200, Nikolay Borisov wrote:
> > Got me curious if we could get rid of the size parameter, it's 2x
> > PAGE_SIZE and could be something else in one case but it's not obvious
> > if it really happens.
> >
> > Another thing I noticed is lack of proper error handling in all callers,
> > as its' 0, 1, and negative errno. The error would be interpreted as true
> > ie. add page to bio and continue.
>
> Actually anything other than 0 is returned then the current bio is
> actually submitted (I presume you refer to the code in compression.c).
> As a matter of fact I think btrfs_bio_fits_in_stripe could even be
> turned to return a bool value.
>
> THe only time this function could return an error is if the mapping
> logic goes haywire which could happen 'if (offset < stripe_offset) {' or
> we don't find a chunk for the given offset, which is unlikely.
Unlikely yes, but if it's possible to trigger the mapping failure eg. by
a crafted image, it should be handled. Besides the mapping errors, there
are EIO or ENOMEM in __btrfs_map_block or its callees. I see all other
callers of map block handle the errors.
