On 4/27/20 1:31 PM, Johannes Thumshirn wrote:
From: Keith Busch <kbusch@xxxxxxxxxx> Define REQ_OP_ZONE_APPEND to append-write sectors to a zone of a zoned block device. This is a no-merge write operation. A zone append write BIO must: * Target a zoned block device * Have a sector position indicating the start sector of the target zone * The target zone must be a sequential write zone * The BIO must not cross a zone boundary * The BIO size must not be split to ensure that a single range of LBAs is written with a single command. Implement these checks in generic_make_request_checks() using the helper function blk_check_zone_append(). To avoid write append BIO splitting, introduce the new max_zone_append_sectors queue limit attribute and ensure that a BIO size is always lower than this limit. Export this new limit through sysfs and check these limits in bio_full(). Also when a LLDD can't dispatch a request to a specific zone, it will return BLK_STS_ZONE_RESOURCE indicating this request needs to be delayed, e.g. because the zone it will be dispatched to is still write-locked. If this happens set the request aside in a local list to continue trying dispatching requests such as READ requests or a WRITE/ZONE_APPEND requests targetting other zones. This way we can still keep a high queue depth without starving other requests even if one request can't be served due to zone write-locking. Finally, make sure that the bio sector position indicates the actual write position as indicated by the device on completion. Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx> [ jth: added zone-append specific add_page and merge_page helpers ] Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> --- block/bio.c | 62 ++++++++++++++++++++++++++++++++++++--- block/blk-core.c | 52 ++++++++++++++++++++++++++++++++ block/blk-mq.c | 27 +++++++++++++++++ block/blk-settings.c | 23 +++++++++++++++ block/blk-sysfs.c | 13 ++++++++ drivers/scsi/scsi_lib.c | 1 + include/linux/blk_types.h | 14 +++++++++ include/linux/blkdev.h | 11 +++++++ 8 files changed, 199 insertions(+), 4 deletions(-)
Reviewed-by: Hannes Reinecke <hare@xxxxxxx> Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@xxxxxxx +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
