On Thu, Jun 02, 2016 at 04:22:37PM +0100, David Drysdale wrote:

On Sat, May 28, 2016 at 5:05 AM, Xiong Zhou [off-list ref] wrote:

quoted

On Fri, May 27, 2016 at 04:46:17PM +0800, Xiong Zhou wrote:
...

quoted

Still working on to id which commit in this merge causes this issuer,

Narrowed down to:

37e5823 block: add offset in blk_add_request_payload()

...

quoted

0bf77e9 nvme: switch to RCU freeing the namespace
9082e87 block: remove struct bio_batch

FWIW, I'm also seeing kmemleak report a leak with v4.7-rc1, in
a different scenario (just normal desktop use).  Not done much
digging so far, but this commit (9082e87bf) looks like it might be
relevant

<snip..>

Thanks for the tip, accelerated my searching in the block merge.

On top of v4.7-rc1 , in order to revert this commit cleanly:

	9082e87 block: remove struct bio_batch

, have to revert these two:

	bbd848e0f block: reinstate early return of -EOPNOTSUPP from blkdev_issue_discard
	38f2525 block: add __blkdev_issue_discard

, then have to revert these two dependances:

202bae5 dm thin: unroll issue_discard() to create longer discard bio chains
3dba53a9 dm thin: use __blkdev_issue_discard for async discard support

With all these five commits reverted, NO memleak happens.

Reverting other four commits while not reverting 9082e87, memleak
happens.

Thanks,
Xiong