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

@@ -92,6 +92,11 @@ typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv,
typedef int (*dm_prepare_ioctl_fn) (struct dm_target *ti, struct block_device **bdev);
typedef int (*dm_report_zones_fn) (struct dm_target *ti, sector_t sector,
struct blk_zone *zones,
unsigned int *nr_zones,
gfp_t gfp_mask);
/*
* These iteration functions are typically used to check (and combine)
* properties of underlying devices.
@@ -180,6 +185,9 @@ struct target_type {
dm_status_fn status;
dm_message_fn message;
dm_prepare_ioctl_fn prepare_ioctl;
#ifdef CONFIG_BLK_DEV_ZONED
dm_report_zones_fn report_zones;
#endif
dm_busy_fn busy;
dm_iterate_devices_fn iterate_devices;
dm_io_hints_fn io_hints;
@@ -420,8 +428,8 @@ struct gendisk *dm_disk(struct mapped_device *md);
int dm_suspended(struct dm_target *ti);
int dm_noflush_suspending(struct dm_target *ti);
void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors);
void dm_remap_zone_report(struct dm_target *ti, struct bio *bio,
sector_t start);
void dm_remap_zone_report(struct dm_target *ti, sector_t start,
struct blk_zone *zones, unsigned int *nr_zones);
union map_info *dm_get_rq_mapinfo(struct request *rq);
struct queue_limits *dm_get_queue_limits(struct mapped_device *md);