kernel/drivers/block/null_blk_main.c, branch linux-6.9.y

null_blk: Move driver into its own directory

2020-12-08T00:36:04Z

Move null_blk driver code into the new sub-directory drivers/block/null_blk. Suggested-by: Bart Van Assche Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

null_blk: Allow controlling max_hw_sectors limit

2020-12-08T00:36:04Z

Add the module option and configfs attribute max_sectors to allow configuring the maximum size of a command issued to a null_blk device. This allows exercising the block layer BIO splitting with different limits than the default BLK_SAFE_MAX_SECTORS. This is also useful for testing the zone append write path of file systems as the max_hw_sectors limit value is also used for the max_zone_append_sectors limit. Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

null_blk: discard zones on reset

2020-12-08T00:36:03Z

When memory backing is enabled, use null_handle_discard() to free the backing memory used by a zone when the zone is being reset. Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

null_blk: cleanup discard handling

2020-12-08T00:36:03Z

null_handle_discard() is called from both null_handle_rq() and null_handle_bio(). As these functions are only passed a nullb_cmd structure, this forces pointer dereferences to identiify the discard operation code and to access the sector range to be discarded. Simplify all this by changing the interface of the functions null_handle_discard() and null_handle_memory_backed() to pass along the operation code, operation start sector and number of sectors. With this change null_handle_discard() can be called directly from null_handle_memory_backed(). Also add a message warning that the discard configuration attribute has no effect when memory backing is disabled. No functional change is introduced by this patch. Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

null_blk: add support for max open/active zone limit for zoned devices

2020-09-29T14:12:48Z

Add support for user space to set a max open zone and a max active zone limit via configfs. By default, the default values are 0 == no limit. Call the block layer API functions used for exposing the configured limits to sysfs. Add accounting in null_blk_zoned so that these new limits are respected. Performing an operation that would exceed these limits results in a standard I/O error. A max open zone limit exists in the ZBC standard. While null_blk_zoned is used to test the Zoned Block Device model in Linux, when it comes to differences between ZBC and ZNS, null_blk_zoned mostly follows ZBC. Therefore, implement the manage open zone resources function from ZBC, but additionally add support for max active zones. This enables user space not only to test against a device with an open zone limit, but also to test against a device with an active zone limit. Signed-off-by: Niklas Cassel Reviewed-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

null_blk: Support shared tag bitmap

2020-09-24T19:44:44Z

Support a shared tag bitmap, whereby request tags are unique over all submission queues, and not just per submission queue. As such, per device total queue depth is normally hw_queue_depth * submit_queues, but hw_queue_depth when set. And a similar story for when shared_tags is set, where that is the queue depth over all null blk devices. Signed-off-by: John Garry Tested-by: Douglas Gilbert Signed-off-by: Jens Axboe

null_blk: fix passing of REQ_FUA flag in null_handle_rq

2020-08-21T23:14:28Z

REQ_FUA should be checked using rq->cmd_flags instead of req_op(). Fixes: deb78b419dfda ("nullb: emulate cache") Signed-off-by: Hou Pu Signed-off-by: Jens Axboe

null_blk: introduce zone capacity for zoned device

2020-07-08T14:16:19Z

Allow emulation of a zoned device with a per zone capacity smaller than the zone size as as defined in the Zoned Namespace (ZNS) Command Set specification. The zone capacity defaults to the zone size if not specified and must be smaller than the zone size otherwise. Reviewed-by: Matias Bjørling Reviewed-by: Chaitanya Kulkarni Reviewed-by: Himanshu Madhani Reviewed-by: Martin K. Petersen Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Reviewed-by: Daniel Wagner Signed-off-by: Aravind Ramesh Signed-off-by: Christoph Hellwig

block: move ->make_request_fn to struct block_device_operations

2020-07-01T13:27:24Z

The make_request_fn is a little weird in that it sits directly in struct request_queue instead of an operation vector. Replace it with a block_device_operations method called submit_bio (which describes much better what it does). Also remove the request_queue argument to it, as the queue can be derived pretty trivially from the bio. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

null_blk: stop using ->queuedata for bio mode

2020-07-01T13:27:23Z

Instead of setting up the queuedata as well just use one private data field. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe