Subject: Re: linux-next: manual merge of the block tree with Linus' tree

From: Jens Axboe <[email-masked]>
Date: Thu, 21 Jan 2016 15:48:19 -0700

On 01/21/2016 03:46 PM, Stephen Rothwell wrote:
> Hi Jens,
>
> On Thu, 31 Dec 2015 14:34:57 +1100 Stephen Rothwell <[email-masked]> wrote:
>>
>> Today's linux-next merge of the block tree got a conflict in:
>>
>>    drivers/nvme/host/pci.c
>>
>> between commit:
>>
>>    b5875222de2f ("NVMe: IO ending fixes on surprise removal")
>>
>> from Linus' tree and commit:
>>
>>    5bae7f73d378 ("nvme: move namespace scanning to common code")
>>
>> from the block tree.
>>
>> I fixed it up (the code was moved - I added the fix patch below) and
>> can carry the fix as necessary (no action is required).
>>
>> However, there was another part to the former patch that I could not
>> quite figure out how to reproduce - the fix to nvme_dev_remove().
>>
>> From: Stephen Rothwell <[email-masked]>
>> Date: Thu, 31 Dec 2015 14:21:38 +1100
>> Subject: [PATCH] nvme: merge fix up for ns code movement
>>
>> Signed-off-by: Stephen Rothwell <[email-masked]>
>> ---
>>   drivers/nvme/host/core.c | 11 ++++++++++-
>>   1 file changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
>> index 1437ff36e91c..1375a83593b5 100644
>> --- a/drivers/nvme/host/core.c
>> +++ b/drivers/nvme/host/core.c
>> @@ -1118,8 +1118,17 @@ static void nvme_ns_remove(struct nvme_ns *ns)
>>   	bool kill = nvme_io_incapable(ns->ctrl) &&
>>   			!blk_queue_dying(ns->queue);
>>
>> -	if (kill)
>> +	if (kill) {
>>   		blk_set_queue_dying(ns->queue);
>> +
>> +		/*
>> +		 * The controller was shutdown first if we got here through
>> +		 * device removal. The shutdown may requeue outstanding
>> +		 * requests. These need to be aborted immediately so
>> +		 * del_gendisk doesn't block indefinitely for their completion.
>> +		 */
>> +		blk_mq_abort_requeue_list(ns->queue);
>> +	}
>>   	if (ns->disk->flags & GENHD_FL_UP) {
>>   		if (blk_get_integrity(ns->disk))
>>   			blk_integrity_unregister(ns->disk);
>> --
>> 2.6.4
>
> So, I have been applying the above merge fix patch since Dec 31 and now
> wonder if Linus needs to be told about it.  Also noone every replied
> about the nvme_dev_remove() part.

Linus is usually pretty damn good at figuring out, and seems to have fun 
doing it. So I usually just defer to acking a merge resolution, but even 
that is rarely needed. It was more of a mess this time around between 
mainline and the nvme branch than I would have liked though, but mostly 
due to timing of branching.

-- 
Jens Axboe