Re: [PATCH 1/2] fs: Replace direct ->bmap calls by bmap()

[Carlos Maiolino <cmaiolino@redhat.com>]

On Wed, Sep 05, 2018 at 08:55:39PM +0200, Christoph Hellwig wrote:
> On Wed, Sep 05, 2018 at 09:23:26AM -0500, Eric Sandeen wrote:
> > >  	block0 = page->index;
> > >  	block0 <<= shift;
> > >  
> > > -	block = inode->i_mapping->a_ops->bmap(inode->i_mapping, block0);
> > > +	block = bmap(inode, block0);
> > 
> > Prior to this there's an ASSERT that inode->i_mapping->a_ops->bmap
> > exists.  Should that stay, if the goal is to move all ->bmap use out
> > of calling code?
> 
> I think it needs to go away.

/me will keep it in mind
> 
> > OTOH, what will this code do if bmap() finds that there
> > is no ->bmap present and returns 0?
> 
> I think we just need to fix the bmap() prototype so that it can return
> error, which would be very useful for various reasons.  Something like
> this:
> 
> int bmap(struct address_space *mapping, sector_t *block)
> {
> 	if (!mapping->a_ops->bmap)
> 		return -EINVAL;
> 	*block = mapping->a_ops->bmap(mapping, *block);
> 	return 0;
> }
> 
> then add fiemap support with real error handling later.

Will do, thanks for the suggestion.


-- 
Carlos