[PATCH 0/8] block: prepare for multipage bvecs

[Ming Lei]

Hi,

Interests[1] have been shown in multipage bvecs, so this patchset
try to prepare for the support and do two things:

1) the 1st 4 patches use bvec iterator to implement iterate_bvec(),
then we can drop the non-standard way for iterating bvec

2) remove BIO_MAX_SECTORS & BIO_MAX_SIZE, and now there is only
one user for each. Once multipage bvecs is introduced, one bio
may hold lots of sectors, and we should always use sort of BIO_MAX_VECS
which should be introduced in future and is similiar with current
BIO_MAX_PAGES.

xfstests(-a auto) have been run and no regression found by this
patchset against linus v4.5+.

 drivers/block/drbd/drbd_int.h |  4 +--
 fs/xfs/xfs_buf.c              |  2 +-
 include/linux/bio.h           | 55 +------------------------------
 include/linux/blk_types.h     |  4 +--
 include/linux/bvec_iter.h     | 77 +++++++++++++++++++++++++++++++++++++++++++
 lib/iov_iter.c                | 31 +++++++----------
 6 files changed, 94 insertions(+), 79 deletions(-)


[1], http://marc.info/?w=2&r=1&s=++[LSF%2FMM+ATTEND]+block%3A+multipage+bvecs&q=t


Thanks,
Ming