block: add a report_zones method

Dispatching a report zones command through the request queue is a major
pain due to the command reply payload rewriting necessary. Given that
blkdev_report_zones() is executing everything synchronously, implement
report zones as a block device file operation instead, allowing major
simplification of the code in many places.

sd, null-blk, dm-linear and dm-flakey being the only block device
drivers supporting exposing zoned block devices, these drivers are
modified to provide the device side implementation of the
report_zones() block device file operation.

For device mappers, a new report_zones() target type operation is
defined so that the upper block layer calls blkdev_report_zones() can
be propagated down to the underlying devices of the dm targets.
Implementation for this new operation is added to the dm-linear and
dm-flakey targets.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
[Damien]
* Changed method block_device argument to gendisk
* Various bug fixes and improvements
* Added support for null_blk, dm-linear and dm-flakey.
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig
2018-10-12 19:08:49 +09:00
committed by Jens Axboe
parent 965b652e90
commit e76239a374
16 changed files with 270 additions and 429 deletions

View File

@@ -87,7 +87,9 @@ struct nullb {
#ifdef CONFIG_BLK_DEV_ZONED
int null_zone_init(struct nullb_device *dev);
void null_zone_exit(struct nullb_device *dev);
blk_status_t null_zone_report(struct nullb *nullb, struct bio *bio);
int null_zone_report(struct gendisk *disk, sector_t sector,
struct blk_zone *zones, unsigned int *nr_zones,
gfp_t gfp_mask);
void null_zone_write(struct nullb_cmd *cmd, sector_t sector,
unsigned int nr_sectors);
void null_zone_reset(struct nullb_cmd *cmd, sector_t sector);
@@ -97,10 +99,11 @@ static inline int null_zone_init(struct nullb_device *dev)
return -EINVAL;
}
static inline void null_zone_exit(struct nullb_device *dev) {}
static inline blk_status_t null_zone_report(struct nullb *nullb,
struct bio *bio)
static inline int null_zone_report(struct gendisk *disk, sector_t sector,
struct blk_zone *zones,
unsigned int *nr_zones, gfp_t gfp_mask)
{
return BLK_STS_NOTSUPP;
return -EOPNOTSUPP;
}
static inline void null_zone_write(struct nullb_cmd *cmd, sector_t sector,
unsigned int nr_sectors)

View File

@@ -1129,34 +1129,12 @@ static void null_restart_queue_async(struct nullb *nullb)
blk_mq_start_stopped_hw_queues(q, true);
}
static bool cmd_report_zone(struct nullb *nullb, struct nullb_cmd *cmd)
{
struct nullb_device *dev = cmd->nq->dev;
if (dev->queue_mode == NULL_Q_BIO) {
if (bio_op(cmd->bio) == REQ_OP_ZONE_REPORT) {
cmd->error = null_zone_report(nullb, cmd->bio);
return true;
}
} else {
if (req_op(cmd->rq) == REQ_OP_ZONE_REPORT) {
cmd->error = null_zone_report(nullb, cmd->rq->bio);
return true;
}
}
return false;
}
static blk_status_t null_handle_cmd(struct nullb_cmd *cmd)
{
struct nullb_device *dev = cmd->nq->dev;
struct nullb *nullb = dev->nullb;
int err = 0;
if (cmd_report_zone(nullb, cmd))
goto out;
if (test_bit(NULLB_DEV_FL_THROTTLED, &dev->flags)) {
struct request *rq = cmd->rq;
@@ -1443,6 +1421,7 @@ static const struct block_device_operations null_fops = {
.owner = THIS_MODULE,
.open = null_open,
.release = null_release,
.report_zones = null_zone_report,
};
static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq)

View File

@@ -48,54 +48,27 @@ void null_zone_exit(struct nullb_device *dev)
kvfree(dev->zones);
}
static void null_zone_fill_bio(struct nullb_device *dev, struct bio *bio,
unsigned int zno, unsigned int nr_zones)
{
struct blk_zone_report_hdr *hdr = NULL;
struct bio_vec bvec;
struct bvec_iter iter;
void *addr;
unsigned int zones_to_cpy;
bio_for_each_segment(bvec, bio, iter) {
addr = kmap_atomic(bvec.bv_page);
zones_to_cpy = bvec.bv_len / sizeof(struct blk_zone);
if (!hdr) {
hdr = (struct blk_zone_report_hdr *)addr;
hdr->nr_zones = nr_zones;
zones_to_cpy--;
addr += sizeof(struct blk_zone_report_hdr);
}
zones_to_cpy = min_t(unsigned int, zones_to_cpy, nr_zones);
memcpy(addr, &dev->zones[zno],
zones_to_cpy * sizeof(struct blk_zone));
kunmap_atomic(addr);
nr_zones -= zones_to_cpy;
zno += zones_to_cpy;
if (!nr_zones)
break;
}
}
blk_status_t null_zone_report(struct nullb *nullb, struct bio *bio)
int null_zone_report(struct gendisk *disk, sector_t sector,
struct blk_zone *zones, unsigned int *nr_zones,
gfp_t gfp_mask)
{
struct nullb *nullb = disk->private_data;
struct nullb_device *dev = nullb->dev;
unsigned int zno = null_zone_no(dev, bio->bi_iter.bi_sector);
unsigned int nr_zones = dev->nr_zones - zno;
unsigned int max_zones;
unsigned int zno, nrz = 0;
max_zones = (bio->bi_iter.bi_size / sizeof(struct blk_zone)) - 1;
nr_zones = min_t(unsigned int, nr_zones, max_zones);
null_zone_fill_bio(nullb->dev, bio, zno, nr_zones);
if (!dev->zoned)
/* Not a zoned null device */
return -EOPNOTSUPP;
return BLK_STS_OK;
zno = null_zone_no(dev, sector);
if (zno < dev->nr_zones) {
nrz = min_t(unsigned int, *nr_zones, dev->nr_zones - zno);
memcpy(zones, &dev->zones[zno], nrz * sizeof(struct blk_zone));
}
*nr_zones = nrz;
return 0;
}
void null_zone_write(struct nullb_cmd *cmd, sector_t sector,