[dm-devel] [PATCH v4 03/11] block: introduce BIO_ZONE_WRITE_LOCKED bio flag
Himanshu Madhani
himanshu.madhani at oracle.com
Tue May 25 19:09:39 UTC 2021
On 5/24/21 9:25 PM, 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. 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.lemoal at wdc.com>
> Reviewed-by: Christoph Hellwig <hch at lst.de>
> Reviewed-by: Hannes Reinecke <hare at suse.de>
> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.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
> };
>
>
Reviewed-by: Himanshu Madhani <himanshu.madhani at oracle.com>
--
Himanshu Madhani Oracle Linux Engineering
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