[PATCH V2 0/2] block: fix page leak by merging to same page

[Ming Lei <ming.lei@redhat.com>]

Hi,

'pages' retrived by __bio_iov_iter_get_pages() may point to same page,
and finally they can be merged to the same page in bio_add_page(), then
page leak can be caused because bio_release_pages() only drops the page
ref once.

Fixes this issue by dropping the extra page ref.

V2:
	- V1 breaks multi-page merge, and fix it and only put the page ref
	if the added page is really the 'same page' 


Ming Lei (2):
  block: introduce 'enum bvec_merge_flags' for __bio_try_merge_page
  block: fix page leak in case of merging to same page

 block/bio.c         | 32 ++++++++++++++++++++++----------
 fs/iomap.c          |  3 ++-
 fs/xfs/xfs_aops.c   |  3 ++-
 include/linux/bio.h |  9 ++++++++-
 4 files changed, 34 insertions(+), 13 deletions(-)

Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: linux-xfs@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
-- 
2.20.1