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. Since in this
case, the lock flag must not be propagated to the struct request that
will be used to process the BIO, a BIO private flag is used rather than
changing the RQF_ZONE_WRITE_LOCKED request flag into a common REQ_XXX
flag that could be used for both BIO and request. This avoids conflicts
down the stack with the block IO scheduler zone write locking
(in mq-deadline).

Signed-off-by: Damien Le Moal <damien.lem...@wdc.com>
Reviewed-by: Christoph Hellwig <h...@lst.de>
Reviewed-by: Hannes Reinecke <h...@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulka...@wdc.com>
Reviewed-by: Himanshu Madhani <himanshu.madh...@oracle.com>
---
 include/linux/blk_types.h | 1 +
 1 file changed, 1 insertion(+)

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
 };
 
-- 
2.31.1

--
dm-devel mailing list
dm-devel@redhat.com
https://listman.redhat.com/mailman/listinfo/dm-devel

Reply via email to