| Message ID | 20170925061454.5533-7-damien.lemoal@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Sep 25, 2017 at 03:14:46PM +0900, Damien Le Moal wrote: > Components relying only on the requeuest_queue structure for accessing > block devices (e.g. I/O schedulers) have a limited knowledged of the > device characteristics. In particular, the device capacity cannot be > easily discovered, which for a zoned block device also result in the > inability to easily know the number of zones of the device (the zone > size is indicated by the chunk_sectors field of the queue limits). > > Introduce the nr_zones field to the request_queue sturcture to simplify > access to this information. Also, add the bitmap seq_zone_bitmap which > indicates which zones of the device are sequential zones (write > preferred or write required). These two fields are initialized by the > low level block device driver (sd.c for ZBC/ZAC disks). They are not > initialized by stacking drivers (device mappers) handling zoned block > devices (e.g. dm-linear). > > Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> > Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com>
On Mon, 2017-09-25 at 15:14 +0900, Damien Le Moal wrote: > Components relying only on the requeuest_queue structure for accessing > block devices (e.g. I/O schedulers) have a limited knowledged of the > device characteristics. In particular, the device capacity cannot be > easily discovered, which for a zoned block device also result in the > inability to easily know the number of zones of the device (the zone > size is indicated by the chunk_sectors field of the queue limits). > > Introduce the nr_zones field to the request_queue sturcture to simplify > access to this information. Also, add the bitmap seq_zone_bitmap which > indicates which zones of the device are sequential zones (write > preferred or write required). These two fields are initialized by the > low level block device driver (sd.c for ZBC/ZAC disks). They are not > initialized by stacking drivers (device mappers) handling zoned block > devices (e.g. dm-linear). Reviewed-by: Bart Van Assche <Bart.VanAssche@wdc.com>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 460294bb0fa5..90285f39030d 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -544,6 +544,18 @@ struct request_queue { struct queue_limits limits; /* + * Zoned block device information for mq I/O schedulers. + * nr_zones is the total number of zones of the device. This is always + * 0 for regular block devices. seq_zone_bitmap is a bitmap of nr_zones + * bits which indicates if a zone is conventional (bit clear) or + * sequential (bit set). Both nr_zones and seq_zone_bitmap are set + * by the low level device driver. Stacking drivers (device mappers) + * may or may not initialize these fields. + */ + unsigned int nr_zones; + unsigned long *seq_zone_bitmap; + + /* * sg stuff */ unsigned int sg_timeout; @@ -785,6 +797,27 @@ static inline unsigned int blk_queue_zone_sectors(struct request_queue *q) return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0; } +static inline unsigned int blk_queue_nr_zones(struct request_queue *q) +{ + return q->nr_zones; +} + +static inline unsigned int blk_queue_zone_no(struct request_queue *q, + sector_t sector) +{ + if (!blk_queue_is_zoned(q)) + return 0; + return sector >> ilog2(q->limits.chunk_sectors); +} + +static inline bool blk_queue_zone_is_seq(struct request_queue *q, + sector_t sector) +{ + if (!blk_queue_is_zoned(q) || !q->seq_zone_bitmap) + return false; + return test_bit(blk_queue_zone_no(q, sector), q->seq_zone_bitmap); +} + static inline bool rq_is_sync(struct request *rq) { return op_is_sync(rq->cmd_flags); @@ -1031,6 +1064,16 @@ static inline unsigned int blk_rq_cur_sectors(const struct request *rq) return blk_rq_cur_bytes(rq) >> 9; } +static inline unsigned int blk_rq_zone_no(struct request *rq) +{ + return blk_queue_zone_no(rq->q, blk_rq_pos(rq)); +} + +static inline unsigned int blk_rq_zone_is_seq(struct request *rq) +{ + return blk_queue_zone_is_seq(rq->q, blk_rq_pos(rq)); +} + /* * Some commands like WRITE SAME have a payload or data transfer size which * is different from the size of the request. Any driver that supports such @@ -1582,6 +1625,16 @@ static inline unsigned int bdev_zone_sectors(struct block_device *bdev) return 0; } +static inline unsigned int bdev_nr_zones(struct block_device *bdev) +{ + struct request_queue *q = bdev_get_queue(bdev); + + if (q) + return blk_queue_nr_zones(q); + + return 0; +} + static inline int queue_dma_alignment(struct request_queue *q) { return q ? q->dma_alignment : 511;