RE: [GIT PULL] Block pull request for- 4.11-rc1

From: Bart Van Assche
Date: Mon Feb 20 2017 - 11:17:17 EST

On 02/19/2017 11:35 PM, Christoph Hellwig wrote:
> On Sun, Feb 19, 2017 at 06:15:41PM -0700, Jens Axboe wrote:
>> That said, we will look into this again, of course. Christoph, any idea?
> No idea really - this seems so far away from the code touched, and there
> are no obvious signs for a memory scamble from another object touched
> that I think if it really bisects down to that issue it must be a timing
> issue.
> But reading Bart's message again: Did you actually bisect it down
> to the is commit? Or just test the whole tree? Between the 4.10-rc5
> merge and all the block tree there might a few more likely suspects
> like the scsi bdi lifetime fixes that James mentioned.

Hello Christoph,

As far as I know Jens does not rebase his trees so we can use the commit
date to check which patch went in when. From the first of Jan's bdi patches:

CommitDate: Thu Feb 2 08:18:41 2017 -0700

So the bdi patches went in several days after I reported the general protection
fault issue.

In an e-mail of January 30th I wrote the following: "Running the srp-test
software against kernel 4.9.6 and kernel 4.10-rc5 went fine. With your
for-4.11/block branch (commit 400f73b23f457a) however I just ran into
the following warning: [ ... ]" That means that I did not hit the crash with
Jens' for-4.11/block branch but only with the for-next branch. The patches
on Jens' for-next branch after that commit that were applied before I ran
my test are:

$ PAGER= git log --format=oneline 400f73b23f457a..fb045ca25cc7 block drivers/md/dm{,-mpath,-table}.[ch]
fb045ca25cc7b6d46368ab8221774489c2a81648 block: don't assign cmd_flags in __blk_rq_prep_clone
82ed4db499b8598f16f8871261bff088d6b0597f block: split scsi_request out of struct request
8ae94eb65be9425af4d57a4f4cfebfdf03081e93 block/bsg: move queue creation into bsg_setup_queue
eb8db831be80692bf4bda3dfc55001daf64ec299 dm: always defer request allocation to the owner of the request_queue
6d247d7f71d1fa4b66a5f4da7b1daa21510d529b block: allow specifying size for extra command data
5ea708d15a928f7a479987704203616d3274c03b block: simplify blk_init_allocated_queue
e6f7f93d58de74700f83dd0547dd4306248a093d block: fix elevator init check
f924ba70c1b12706c6679d793202e8f4c125f7ae Merge branch 'for-4.11/block' into for-4.11/rq-refactor
88a7503376f4f3bf303c809d1a389739e1205614 blk-mq: Remove unused variable
bef13315e990fd3d3fb4c39013aefd53f06c3657 block: don't try to discard from __blkdev_issue_zeroout
f99e86485cc32cd16e5cc97f9bb0474f28608d84 block: Rename blk_queue_zone_size and bdev_zone_size

Do you see any patch in the above list that does not belong to the "split
scsi passthrough fields out of struct request" series and that could have
caused the reported behavior change?