Ocfs2 devel - Jan 2016 - [dm-devel] [PATCH 02/35] block: add REQ_OP definitions and bi_op/op fields

On 01/09/2016 07:37 AM, Christoph Hellwig wrote:
> Seems like this is missing REQ_OP_FLUSH, which still hides as a write?
> 
I might have misunderstood what you wanted or am misunderstanding you now.

I did not change the flush related code until the last patches. I added
REQ_OP_FLUSH in patch:

[PATCH 33/35] block, drivers: add REQ_OP_FLUSH operation
commit 18dea20363ba245a47bc1bb54f6465b8a05b19af
Author: Mike Christie <mchristi at redhat.com>
Date:   Tue Jan 5 21:02:17 2016 -0600

    block, drivers: add REQ_OP_FLUSH operation


and I added the REQ_PREFLUSH flag in


[PATCH 35/35] block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSH
commit 303dc6a7cc3673065538ba041562fcd833a619af
Author: Mike Christie <mchristi at redhat.com>
Date:   Thu Jan 7 18:17:03 2016 -0600

    block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSH


I did them in separate patches, because I was not sure if they were
correct with what you requested before, and because they were a little
more tricky because of how request_fn drivers, make_request_fn drivers,
and dm-multipath handle flushes differently.

On 01/09/2016 06:56 PM, Mike Christie wrote:
> On 01/09/2016 07:37 AM, Christoph Hellwig wrote:
>> Seems like this is missing REQ_OP_FLUSH, which still hides as a write?
>>
Oh yeah, to answer the second part of your question, REQ_OP_FLUSH is
only a flush operation like what request_fn drivers wanted.

REQ_PREFLUSH can be set with a REQ_OP_WRITE bio when filesystems want to
do both.

There is then the case where filesystems and blkdev_issue_flush could
just want to request a flush. I left them as a REQ_PREFLUSH with
REQ_OP_WRITE set, so there would be a single code path.
> 
> I might have misunderstood what you wanted or am misunderstanding you now.
> 
> I did not change the flush related code until the last patches. I added
> REQ_OP_FLUSH in patch:
> 
> [PATCH 33/35] block, drivers: add REQ_OP_FLUSH operation
> commit 18dea20363ba245a47bc1bb54f6465b8a05b19af
> Author: Mike Christie <mchristi at redhat.com>
> Date:   Tue Jan 5 21:02:17 2016 -0600
> 
>     block, drivers: add REQ_OP_FLUSH operation
> 
> 
> and I added the REQ_PREFLUSH flag in
> 
> 
> [PATCH 35/35] block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSH
> commit 303dc6a7cc3673065538ba041562fcd833a619af
> Author: Mike Christie <mchristi at redhat.com>
> Date:   Thu Jan 7 18:17:03 2016 -0600
> 
>     block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSH
> 
> 
> I did them in separate patches, because I was not sure if they were
> correct with what you requested before, and because they were a little
> more tricky because of how request_fn drivers, make_request_fn drivers,
> and dm-multipath handle flushes differently.
> --
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On Sat, Jan 09, 2016 at 06:56:14PM -0600, Mike Christie
wrote:
> I did not change the flush related code until the last patches. I added
> REQ_OP_FLUSH in patch:
Oh, I missed that.