Re: [PATCH 3/5] ext4: Extent overlap bugfix

["Amit K. Arora" <aarora@xxxxxxxxxxxxxxxxxx>]

On Thu, May 03, 2007 at 09:30:02PM -0700, Andrew Morton wrote:
> On Thu, 26 Apr 2007 23:41:01 +0530 "Amit K. Arora" 
> <aarora@xxxxxxxxxxxxxxxxxx> wrote:
> 
> > +unsigned int ext4_ext_check_overlap(struct inode *inode,
> > +                                   struct ext4_extent *newext,
> > +                                   struct ext4_ext_path *path)
> > +{
> > +   unsigned long b1, b2;
> > +   unsigned int depth, len1;
> > +
> > +   b1 = le32_to_cpu(newext->ee_block);
> > +   len1 = le16_to_cpu(newext->ee_len);
> > +   depth = ext_depth(inode);
> > +   if (!path[depth].p_ext)
> > +           goto out;
> > +   b2 = le32_to_cpu(path[depth].p_ext->ee_block);
> > +
> > +   /* get the next allocated block if the extent in the path
> > +    * is before the requested block(s) */
> > +   if (b2 < b1) {
> > +           b2 = ext4_ext_next_allocated_block(path);
> > +           if (b2 == EXT_MAX_BLOCK)
> > +                   goto out;
> > +   }
> > +
> > +   if (b1 + len1 > b2) {
> 
> Are we sure that b1+len cannot wrap through zero here?

No. Will add a check here for this. Thanks!
 
> > +           newext->ee_len = cpu_to_le16(b2 - b1);
> > +           return 1;
> > +   }


--
Regards,
Amit Arora