On Wed 16-10-19 13:07:06, Ritesh Harjani wrote:

This patch series adds the support for blocksize < pagesize for
dioread_nolock feature.

Since in case of blocksize < pagesize, we can have multiple
small buffers of page as unwritten extents, we need to
maintain a vector of these unwritten extents which needs
the conversion after the IO is complete. Thus, we maintain
a list of tuple <offset, size> pair (io_end_vec) for this &
traverse this list to do the unwritten to written conversion.

Appreciate any reviews/comments on this patches.

I know Ted has merged the patches already so this is just informational but
I've read the patches and they look fine to me. Thanks for the work! I was
just thinking that we could actually make the vector tracking more
efficient because the io_end always looks like:

one-big-extent-to-fully-write + whatever it takes to fully write out the
last page

So your vectors could be also expressed as "extent to write" + bitmap of
blocks written in the last page. And 64-bits are enough for the bitmap for
anything ext4 supports so we could easily save allocation of ioend_vec etc.
Just a suggestion.

								Honza
-- 
Jan Kara [off-list ref]
SUSE Labs, CR