[DRBD-user] [PATCH 07/10] block: kill merge_bvec_fn() completely

NeilBrown neilb at suse.de
Wed Apr 29 00:09:19 CEST 2015

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

On Mon, 27 Apr 2015 23:48:34 -0700 Ming Lin <mlin at kernel.org> wrote:

> From: Kent Overstreet <kent.overstreet at gmail.com>
> As generic_make_request() is now able to handle arbitrarily sized bios,
> it's no longer necessary for each individual block driver to define its
> own ->merge_bvec_fn() callback. Remove every invocation completely.

This patch it just a little premature I think.

md/raid5 still assumes read requests will mostly fit within a single chunk
(which merge_bvec_fn encourages) so they can be serviced without using the
You've just broken that assumption.

I think 'chunk_aligned_read' needs to get a loop using bio_split, a bit like
raid0, first.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 811 bytes
Desc: OpenPGP digital signature
URL: <http://lists.linbit.com/pipermail/drbd-user/attachments/20150429/39a6797d/attachment.pgp>

More information about the drbd-user mailing list