linux.git/drivers/block/rnbd, branch v6.18

drivers/block: WQ_PERCPU added to alloc_workqueue users

2025-09-09T15:11:31+00:00

Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.

alloc_workqueue() treats all queues as per-CPU by default, while unbound
workqueues must opt-in via WQ_UNBOUND.

This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.

This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.

This patch adds a new WQ_PERCPU flag to explicitly request the use of
the per-CPU behavior. Both flags coexist for one release cycle to allow
callers to transition their calls.

Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit default.

With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU.

All existing users have been updated accordingly.

Suggested-by: Tejun Heo 
Signed-off-by: Marco Crivellari 
Signed-off-by: Jens Axboe

block: switch ->getgeo() to struct gendisk

2025-08-13T06:59:29+00:00

Instances are happier that way and it makes more sense anyway -
the only part of the result that is related to partition we are given
is the start sector, and that has been filled in by the caller.

Everything else is a function of the disk.  Only one instance
(DASD) is ever looking at anything other than bdev->bd_disk and
that one is trivial to adjust.

Reviewed-by: Martin K. Petersen 
Reviewed-by: Christoph Hellwig 
Acked-by: Jens Axboe 
Signed-off-by: Al Viro

rnbd-srv: use bio_add_virt_nofail

2025-05-07T13:31:07+00:00

Use the bio_add_virt_nofail to add a single kernel virtual address
to a bio as that can't fail.

Signed-off-by: Christoph Hellwig 
Acked-by: Jack Wang 
Reviewed-by: Damien Le Moal 
Reviewed-by: Johannes Thumshirn 
Link: https://lore.kernel.org/r/20250507120451.4000627-10-hch@lst.de
Signed-off-by: Jens Axboe

block: remove unused parameter 'q' parameter in __blk_rq_map_sg()

2025-03-13T11:46:19+00:00

request_queue param is no longer used by blk_rq_map_sg and
__blk_rq_map_sg. Remove it.

Signed-off-by: Anuj Gupta 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20250313035322.243239-1-anuj20.g@samsung.com
Signed-off-by: Jens Axboe

block: remove BLK_MQ_F_SHOULD_MERGE

2024-12-23T15:17:23+00:00

BLK_MQ_F_SHOULD_MERGE is set for all tag_sets except those that purely
process passthrough commands (bsg-lib, ufs tmf, various nvme admin
queues) and thus don't even check the flag.  Remove it to simplify the
driver interface.

Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20241219060214.1928848-1-hch@lst.de
Signed-off-by: Jens Axboe

block: Delete bio_set_prio()

2024-12-23T15:17:23+00:00

Since commit 43b62ce3ff0a ("block: move bio io prio to a new field"), macro
bio_set_prio() does nothing but set bio->bi_ioprio. All other places just
set bio->bi_ioprio directly, so replace bio_set_prio() remaining
callsites with setting bio->bi_ioprio directly and delete that macro.

Signed-off-by: John Garry 
Acked-by: Jack Wang 
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20241202111957.2311683-3-john.g.garry@oracle.com
Signed-off-by: Jens Axboe

block/rnbd-srv: Add sanity check and remove redundant assignment

2024-08-28T14:50:35+00:00

The bio->bi_iter.bi_size is updated when bio_add_page() is called. So we
do not need to assign msg->bi_size again to it, since its redudant and
can also be harmful. Instead we can use it to add a sanity check, which
checks the locally calculated bi_size, with the one sent in msg.

Signed-off-by: Md Haris Iqbal 
Signed-off-by: Jack Wang 
Signed-off-by: Grzegorz Prajsner 
Link: https://lore.kernel.org/r/20240809135346.978320-1-haris.iqbal@ionos.com
Signed-off-by: Jens Axboe

block/rnbd: Constify struct kobj_type

2024-07-09T17:52:03+00:00

'struct kobj_type' is not modified in this driver. It is only used with
kobject_init_and_add() which takes a "const struct kobj_type *" parameter.

Constifying this structure moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
   4082	    792	      8	   4882	   1312	drivers/block/rnbd/rnbd-srv-sysfs.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
   4210	    672	      8	   4890	   131a	drivers/block/rnbd/rnbd-srv-sysfs.o

Signed-off-by: Christophe JAILLET 
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/e3d454173ffad30726c9351810d3aa7b75122711.1720462252.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Jens Axboe

rnbd-cnt: don't set QUEUE_FLAG_SAME_FORCE

2024-06-28T16:37:34+00:00

QUEUE_FLAG_SAME_FORCE has been set by rnbd-cnt since the initial
merge.  There is no good reason for a driver to force exact core
delivery, which is tunable for very specific workloads and not a
driver setting.

Signed-off-by: Christoph Hellwig 
Acked-by: Jack Wang 
Reviewed-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20240627124926.512662-6-hch@lst.de
Signed-off-by: Jens Axboe

rnbd: don't set QUEUE_FLAG_SAME_COMP

2024-06-28T16:37:34+00:00

QUEUE_FLAG_SAME_COMP is already set by default.

Signed-off-by: Christoph Hellwig 
Acked-by: Jack Wang 
Reviewed-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20240627124926.512662-5-hch@lst.de
Signed-off-by: Jens Axboe