kernel/linux.git/drivers/block/null_blk/null_blk.h, branch v6.12.91

null_blk: Introduce the zone_full parameter

2024-07-05T06:42:04+00:00

Allow creating a zoned null_blk device with the initial state of its sequential write required zones to be FULL. This is convenient to avoid having to first write these zones to perform read performance evaluation or test zone management operations such as zone reset (and zone reset all). Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20240704052816.623865-2-dlemoal@kernel.org Signed-off-by: Jens Axboe

null_blk: Introduce fua attribute

2024-04-17T14:44:03+00:00

Add the fua configfs attribute and module parameter to allow configuring if the device supports FUA or not. Using this attribute has an effect on the null_blk device only if memory backing is enabled together with a write cache (cache_size option). This new attribute allows configuring a null_blk device with a write cache but without FUA support. This is convenient to test the block layer flush machinery. Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Reviewed-by: Bart Van Assche Reviewed-by: Chaitanya Kulkarni Tested-by: Hans Holmberg Tested-by: Dennis Maisenbacher Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20240408014128.205141-18-dlemoal@kernel.org Signed-off-by: Jens Axboe

null_blk: Introduce zone_append_max_sectors attribute

2024-04-17T14:44:03+00:00

Add the zone_append_max_sectors configfs attribute and module parameter to allow configuring the maximum number of 512B sectors of zone append operations. This attribute is meaningful only for zoned null block devices. If not specified, the default is unchanged and the zoned device max append sectors limit is set to the device max sectors limit. If a non 0 value is used for this attribute, which is the default, then native support for zone append operations is enabled. Setting a 0 value disables native zone append operations support to instead use the block layer emulation. Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Reviewed-by: Bart Van Assche Tested-by: Hans Holmberg Tested-by: Dennis Maisenbacher Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20240408014128.205141-17-dlemoal@kernel.org Signed-off-by: Jens Axboe

null_blk: Delete nullb.{queue_depth, nr_queues}

2024-02-22T17:08:47+00:00

Since commit 8b631f9cf0b8 ("null_blk: remove the bio based I/O path"), struct nullb members queue_depth and nr_queues are only ever written, so delete them. With that, null_exit_hctx() can also be deleted. Signed-off-by: John Garry Link: https://lore.kernel.org/r/20240222083420.6026-1-john.g.garry@oracle.com Signed-off-by: Jens Axboe

null_blk: pass queue_limits to blk_mq_alloc_disk

2024-02-20T13:21:27+00:00

Pass the queue limits directly to blk_mq_alloc_disk instead of setting them one at a time. Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Tested-by: Damien Le Moal Link: https://lore.kernel.org/r/20240220093248.3290292-6-hch@lst.de Signed-off-by: Jens Axboe

null_blk: remove the bio based I/O path

2024-02-20T13:21:27+00:00

The bio based I/O path complicates null_blk and also make various data structures, including the per-command one way bigger than required for the main request based interface. As the bio-based path is mostly used by stacking drivers and simple memory based drivers, and brd is a good example driver for the latter there is no need to have a bio based path in null_blk. Remove the path to simplify the driver and make future block layer API changes simpler by not having to deal with the complex two API setup in null_blk. Note that the queue_mode field in struct nullb_device is kept as that is simpler than having two different places to check the value and fully open coding the debugfs helpers as the existing ones won't work without a named struct member. Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Tested-by: Damien Le Moal Link: https://lore.kernel.org/r/20240220093248.3290292-2-hch@lst.de Signed-off-by: Jens Axboe

null_blk: add configfs variable shared_tags

2024-02-08T18:31:23+00:00

Allow setting shared_tags through configfs, which could only be set as a module parameter. For that purpose, delay tag_set initialization from null_init() to null_add_dev(). Refer tag_set.ops as the flag to check if tag_set is initialized or not. The following parameters can not be set through configfs yet: timeout requeue init_hctx Signed-off-by: Shin'ichiro Kawasaki Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20240130042134.2463659-1-shinichiro.kawasaki@wdc.com Signed-off-by: Jens Axboe

block: null_blk: make fault-injection dynamically configurable per device

2023-04-13T13:38:55+00:00

The null_blk driver has multiple driver-specific fault injection mechanisms. Each fault injection configuration can only be specified by a module parameter and cannot be reconfigured without reloading the driver. Also, each configuration is common to all devices and is initialized every time a new device is added. This change adds the following subdirectories for each null_blk device. /sys/kernel/config/nullb//timeout_inject /sys/kernel/config/nullb//requeue_inject /sys/kernel/config/nullb//init_hctx_fault_inject Each fault injection attribute can be dynamically set per device by a corresponding file in these directories. Signed-off-by: Akinobu Mita Link: https://lore.kernel.org/r/20230327143733.14599-3-akinobu.mita@gmail.com Signed-off-by: Jens Axboe

null_blk: support read-only and offline zone conditions

2022-12-01T21:49:48+00:00

In zoned mode, zones with write pointers can have conditions "read-only" or "offline". In read-only condition, zones can not be written. In offline condition, the zones can be neither written nor read. These conditions are intended for zones with media failures, then it is difficult to set those conditions to zones on real devices. To test handling of zones in the conditions, add a feature to null_blk to set up zones in read-only or offline condition. Add new configuration attributes "zone_readonly" and "zone_offline". Write a sector to the attribute files to specify the target zone to set the zone conditions. For example, following command lines do it: echo 0 > nullb1/zone_readonly echo 524288 > nullb1/zone_offline When the specified zones are already in read-only or offline condition, normal empty condition is restored to the zones. These condition changes can be done only after the null_blk device get powered, since status area of each zone is not yet allocated before power-on. Also improve zone condition checks to inhibit all commands for zones in offline conditions. In same manner, inhibit write and zone management commands for zones in read-only condition. Signed-off-by: Shin'ichiro Kawasaki Reviewed-by: Damien Le Moal Link: https://lore.kernel.org/r/20221201061036.2342206-1-shinichiro.kawasaki@wdc.com Signed-off-by: Jens Axboe

null_blk: add configfs variables for 2 options

2022-08-02T23:15:02+00:00

Allow setting via configfs these two options: no_sched shared_tag_bitmap Previously these could only be activated as module parameters. Still missing are: shared_tags timeout requeue init_hctx Signed-off-by: Vincent Fu Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220708174943.87787-3-vincent.fu@samsung.com [axboe: fold in nullb == NULL fix] Signed-off-by: Jens Axboe