On Mon, Jun 10, 2019 at 12:18:17PM +0800, Ming Lei wrote:
> 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 <da...@gibson.dropbear.id.au>
> Cc: "Darrick J. Wong" <darrick.w...@oracle.com>
> Cc: linux-...@vger.kernel.org
> Cc: Alexander Viro <v...@zeniv.linux.org.uk>
> Cc: Christoph Hellwig <h...@infradead.org>
> -- 
> 2.20.1
> 

Please ignore V2, I will improve it a bit and post out V3.


Thanks
Ming

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