diff mbox series

[03/11] block: introduce BIO_ZONE_WRITE_LOCKED bio flag

Message ID 20210519025529.707897-4-damien.lemoal@wdc.com (mailing list archive)
State Superseded, archived
Delegated to: Mike Snitzer
Headers show
Series dm: Improve zoned block device support | expand

Commit Message

Damien Le Moal May 19, 2021, 2:55 a.m. UTC
Introduce the BIO flag BIO_ZONE_WRITE_LOCKED to indicate that a BIO owns
the write lock of the zone it is targeting. This is the counterpart of
the struct request flag RQF_ZONE_WRITE_LOCKED. This new BIO flag is
reserved for now for zone write locking control for device mapper
targets exposing a zoned block device.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
---
 include/linux/blk_types.h | 1 +
 1 file changed, 1 insertion(+)

Comments

Christoph Hellwig May 19, 2021, 9:41 a.m. UTC | #1
On Wed, May 19, 2021 at 11:55:21AM +0900, Damien Le Moal wrote:
> Introduce the BIO flag BIO_ZONE_WRITE_LOCKED to indicate that a BIO owns
> the write lock of the zone it is targeting. This is the counterpart of
> the struct request flag RQF_ZONE_WRITE_LOCKED. This new BIO flag is
> reserved for now for zone write locking control for device mapper
> targets exposing a zoned block device.

So normally we try to use a REQ_* flag instead of duplicate BIO_ and
RQF ones.  But I think this is a special case as the flag never gets
propagated.  Can you document that in the commit log?

With that:

Reviewed-by: Christoph Hellwig <hch@lst.de>

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Damien Le Moal May 19, 2021, 9:50 a.m. UTC | #2
On 2021/05/19 18:42, Christoph Hellwig wrote:
> On Wed, May 19, 2021 at 11:55:21AM +0900, Damien Le Moal wrote:
>> Introduce the BIO flag BIO_ZONE_WRITE_LOCKED to indicate that a BIO owns
>> the write lock of the zone it is targeting. This is the counterpart of
>> the struct request flag RQF_ZONE_WRITE_LOCKED. This new BIO flag is
>> reserved for now for zone write locking control for device mapper
>> targets exposing a zoned block device.
> 
> So normally we try to use a REQ_* flag instead of duplicate BIO_ and
> RQF ones.  But I think this is a special case as the flag never gets
> propagated.  Can you document that in the commit log?

Will do.

> 
> With that:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
>
diff mbox series

Patch

diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index db026b6ec15a..e5cf12f102a2 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -304,6 +304,7 @@  enum {
 	BIO_CGROUP_ACCT,	/* has been accounted to a cgroup */
 	BIO_TRACKED,		/* set if bio goes through the rq_qos path */
 	BIO_REMAPPED,
+	BIO_ZONE_WRITE_LOCKED,	/* Owns a zoned device zone write lock */
 	BIO_FLAG_LAST
 };