Message-Id: <1459857443-20611-1-git-send-email-tom.leiming@gmail.com>
Date:	Tue,  5 Apr 2016 19:56:45 +0800
From:	Ming Lei <tom.leiming@...il.com>
To:	Jens Axboe <axboe@...com>, linux-kernel@...r.kernel.org
Cc:	linux-block@...r.kernel.org, Christoph Hellwig <hch@...radead.org>,
	Boaz Harrosh <boaz@...xistor.com>,
	Ming Lei <tom.leiming@...il.com>,
	Al Viro <viro@...iv.linux.org.uk>,
	Andreas Dilger <andreas.dilger@...el.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	devel@...verdev.osuosl.org (open list:STAGING SUBSYSTEM),
	dm-devel@...hat.com (open list:DEVICE-MAPPER (LVM)),
	drbd-dev@...ts.linbit.com (open list:DRBD DRIVER),
	Frank Zago <fzago@...y.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Hannes Reinecke <hare@...e.de>,
	James Simmons <jsimmons@...radead.org>,
	Jan Kara <jack@...e.cz>, Jarod Wilson <jarod@...hat.com>,
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	Keith Busch <keith.busch@...el.com>,
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	linux-bcache@...r.kernel.org (open list:BCACHE (BLOCK LAYER CACHE)),
	linux-mm@...ck.org (open list:MEMORY MANAGEMENT),
	linux-pm@...r.kernel.org (open list:SUSPEND TO RAM),
	linux-raid@...r.kernel.org (open list:SOFTWARE RAID (Multiple Disks)
	SUPPORT), linux-scsi@...r.kernel.org (open list:TARGET SUBSYSTEM),
	logfs@...fs.org (open list:LogFS),
	lustre-devel@...ts.lustre.org (moderated list:STAGING - LUSTRE PARALLEL
	FILESYSTEM), Mike Rapoport <mike.rapoport@...il.com>,
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	Miklos Szeredi <mszeredi@...e.cz>,
	Minchan Kim <minchan@...nel.org>,
	Ming Lin <ming.l@....samsung.com>, NeilBrown <neilb@...e.com>,
	NeilBrown <neilb@...e.de>, Oleg Drokin <green@...uxhacker.ru>,
	Omar Sandoval <osandov@...ndov.com>,
	Rasmus Villemoes <linux@...musvillemoes.dk>,
	target-devel@...r.kernel.org (open list:TARGET SUBSYSTEM),
	Tejun Heo <tj@...nel.org>
Subject: [PATCH 00/27] block: cleanup direct access on .bi_vcnt & .bi_io_vec

Hi Guys,

It is always not a good practice to access bio->bi_vcnt and
bio->bi_io_vec from drivers directly. Also this kind of direct
access will cause trouble when converting to multipage bvecs.

The 1st patch introduces the following 4 bio helpers which can be
used inside drivers for avoiding direct access to .bi_vcnt and .bi_io_vec.

	bio_pages()
	bio_is_full()
	bio_get_base_vec()
	bio_set_vec_table()

Both bio_pages() and bio_is_full() can be easy to convert to
multipage bvecs.

For bio_get_base_vec() and bio_set_vec_table(), they are often used
during initializing a new bio or in case of single bvec bio. With the
two new helpers, it becomes quite easy to audit access to .bi_io_vec
and .bi_vcnt.

Most of the other patches use the 4 helpers to clean up most of direct
access to .bi_vcnt and .bi_io_vec from drivers, except for MD and btrfs,
which two subsystems will be done in the future. 

Also bio_add_page() is used in floppy, dm-crypt and fs/logfs to
avoiding direct access to .bi_vcnt & .bi_io_vec.

Thanks,
Ming

Ming Lei (27):
  block: bio: introduce 4 helpers for cleanup
  block: drbd: use bio_get_base_vec() to retrieve the 1st bvec
  block: drbd: remove impossible failure handling
  block: loop: use bio_get_base_vec() to retrive bvec table
  block: pktcdvd: use bio_get_base_vec() to retrive bvec table
  block: floppy: use bio_set_vec_table()
  block: floppy: use bio_add_page()
  staging: lustre: avoid to use bio->bi_vcnt directly
  target: use bio_is_full()
  bcache: debug: avoid to access .bi_io_vec directly
  bcache: io.c: use bio_set_vec_table
  bcache: journal.c: use bio_set_vec_table()
  bcache: movinggc: use bio_set_vec_table()
  bcache: writeback: use bio_set_vec_table()
  bcache: super: use bio_set_vec_table()
  bcache: super: use bio_get_base_vec
  dm: crypt: use bio_add_page()
  dm: dm-io.c: use bio_get_base_vec()
  dm: dm.c: replace 'bio->bi_vcnt == 1' with !bio_multiple_segments
  dm: dm-bufio.c: use bio_set_vec_table()
  fs: logfs: use bio_set_vec_table()
  fs: logfs: convert to bio_add_page() in sync_request()
  fs: logfs: use bio_add_page() in __bdev_writeseg()
  fs: logfs: use bio_add_page() in do_erase()
  fs: logfs: remove unnecesary check
  kernel/power/swap.c: use bio_get_base_vec()
  mm: page_io.c: use bio_get_base_vec()

 drivers/block/drbd/drbd_bitmap.c            |   4 +-
 drivers/block/drbd/drbd_receiver.c          |  14 +---
 drivers/block/floppy.c                      |   9 +--
 drivers/block/loop.c                        |   5 +-
 drivers/block/pktcdvd.c                     |   3 +-
 drivers/md/bcache/debug.c                   |  11 ++-
 drivers/md/bcache/io.c                      |   3 +-
 drivers/md/bcache/journal.c                 |   3 +-
 drivers/md/bcache/movinggc.c                |   6 +-
 drivers/md/bcache/super.c                   |  28 +++++---
 drivers/md/bcache/writeback.c               |   4 +-
 drivers/md/dm-bufio.c                       |   3 +-
 drivers/md/dm-crypt.c                       |   8 +--
 drivers/md/dm-io.c                          |   7 +-
 drivers/md/dm.c                             |   3 +-
 drivers/staging/lustre/lustre/llite/lloop.c |   9 +--
 drivers/target/target_core_pscsi.c          |   2 +-
 fs/logfs/dev_bdev.c                         | 107 +++++++++++-----------------
 include/linux/bio.h                         |  28 ++++++++
 kernel/power/swap.c                         |  10 ++-
 mm/page_io.c                                |  18 ++++-
 21 files changed, 156 insertions(+), 129 deletions(-)

-- 
1.9.1

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