On Fri, Nov 18, 2016 at 05:29:06PM -0800, Liu Bo wrote:
> On Wed, Nov 16, 2016 at 01:52:08PM +0100, Christoph Hellwig wrote:
> > Pass the full bio to the decompression routines and use bio iterators
> > to iterate over the data in the bio.
>
> One question below,
It would be nice to cut down the email to actually find your question
without running through hundreds+ quoted lines.
> > /* copy bytes from the working buffer into the pages */
> > while (working_bytes > 0) {
> > - bytes = min(PAGE_SIZE - *pg_offset,
> > - PAGE_SIZE - buf_offset);
> > + bytes = min_t(unsigned long, bvec.bv_len,
> > + PAGE_SIZE - buf_offset);
> > bytes = min(bytes, working_bytes);
> > - kaddr = kmap_atomic(page_out);
> > - memcpy(kaddr + *pg_offset, buf + buf_offset, bytes);
> > +
> > + kaddr = kmap_atomic(bvec.bv_page);
> > + memcpy(kaddr + bvec.bv_offset, buf + buf_offset, bytes);
>
> This doesn't seem to be right, 'bvec.bv_offset' is not updated in the
> following bio_advance(bio, bytes),
Good spot - and this means xfstests doesn't cover this area very
well :(
> shouldn't it be
> 'kaddr + bvec.bv_offset + bio->bi_iter.bi_bvec_done'?
No, we just need to get a new bvec using bio_iter_iovec after
the call to bio_advance.
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