linux.git/drivers/block/null_blk, branch v5.18

block: null_blk: end timed out poll request

2022-04-14T16:16:33+00:00

When poll request is timed out, it is removed from the poll list,
but not completed, so the request is leaked, and never get chance
to complete.

Fix the issue by ending it in timeout handler.

Fixes: 0a593fbbc245 ("null_blk: poll queue support")
Signed-off-by: Ming Lei 
Link: https://lore.kernel.org/r/20220413084836.1571995-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe

null_blk: null_alloc_page() cleanup

2022-02-27T21:49:49+00:00

Remove goto labels and use direct returns as error unwinding code only
needs to free t_page variable if we alloc_pages() call fails as having
two labels for one kfree() can be avoided easily.

Signed-off-by: Chaitanya Kulkarni 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20220222152852.26043-3-kch@nvidia.com
Signed-off-by: Jens Axboe

null_blk: remove hardcoded null_alloc_page() param

2022-02-27T21:49:49+00:00

Only caller of null_alloc_page() is null_insert_page() unconditionally
sets only parameter to GFP_NOIO and that is statically hard-coded in
null_blk. There is no point in having statically hardcoded function
parameter.

Remove the unnecessary parameter gfp_flags and adjust the code, so it
can retain existing behavior null_alloc_page() with GFP_NOIO.

Signed-off-by: Chaitanya Kulkarni 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20220222152852.26043-2-kch@nvidia.com
Signed-off-by: Jens Axboe

null_blk: remove hardcoded alloc_cmd() parameter

2022-02-27T21:49:49+00:00

Only caller of alloc_cmd() is null_submit_bio() unconditionally sets
second parameter to true and that is statically hard-coded in null_blk.
There is no point in having statically hardcoded function parameter.

Remove the unnecessary parameter can_wait and adjust the code so it
can retain existing behavior of waiting when we don't get valid
nullb_cmd from __alloc_cmd() in alloc_cmd().

The restructured code avoids multiple return statements, multiple
calls to __alloc_cmd() and resulting a fast path call to
prepare_to_wait() due to removal of first alloc_cmd() call.

Follow the pattern that we have in bio_alloc() to set the structure
members in the structure allocation function in alloc_cmd() and pass
bio to initialize newly allocated cmd->bio member.

Follow the pattern in copy_to_nullb() to use result of one function call
(null_cache_active()) to be used as a parameter to another function call
(null_insert_page()), use result of alloc_cmd() as a first parameter to
the null_handle_cmd() in null_submit_bio() function. This allow us to
remove the local variable cmd on stack in null_submit_bio() that is in
fast path.

Signed-off-by: Chaitanya Kulkarni 
Reviewed-by: Damien Le Moal 
Link: https://lore.kernel.org/r/20220216172945.31124-2-kch@nvidia.com
Signed-off-by: Jens Axboe

null_blk: fix return value from null_add_dev()

2022-02-27T21:49:49+00:00

The function nullb_device_power_store() returns -ENOMEM when
null_add_dev() fails. null_add_dev() can fail with return value
other than -ENOMEM such as -EINVAL when Zoned Block Device option
is used, see :

nullb_device_power_store()
 null_add_dev()
  null_init_zoned_dev()
	return -EINVAL;

When trying to load the module having -ENOMEM value returned on the
command line creates confusion when pleanty of memory is free on the
machine.

Instead of hardcoding -ENOMEM return the value of null_add_dev()
function.

Signed-off-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20220215115951.15945-1-kch@nvidia.com
Signed-off-by: Jens Axboe

block: null_blk: only set set->nr_maps as 3 if active poll_queues is > 0

2021-12-24T05:05:50+00:00

It isn't correct to set set->nr_maps as 3 if g_poll_queues is > 0 since
we can change it via configfs for null_blk device created there, so only
set it as 3 if active poll_queues is > 0.

Fixes divide zero exception reported by Shinichiro.

Fixes: 2bfdbe8b7ebd ("null_blk: allow zero poll queues")
Reported-by: Shinichiro Kawasaki 
Signed-off-by: Ming Lei 
Reviewed-by: Shin'ichiro Kawasaki 
Link: https://lore.kernel.org/r/20211224010831.1521805-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe

null_blk: cast command status to integer

2021-12-10T23:32:44+00:00

kernel test robot reports that sparse now triggers a warning on null_blk:

>> drivers/block/null_blk/main.c:1577:55: sparse: sparse: incorrect type in argument 3 (different base types) @@     expected int ioerror @@     got restricted blk_status_t [usertype] error @@
   drivers/block/null_blk/main.c:1577:55: sparse:     expected int ioerror
   drivers/block/null_blk/main.c:1577:55: sparse:     got restricted blk_status_t [usertype] error

because blk_mq_add_to_batch() takes an integer instead of a blk_status_t.
Just cast this to an integer to silence it, null_blk is the odd one out
here since the command status is the "right" type. If we change the
function type, then we'll have do that for other callers too (existing and
future ones).

Fixes: 2385ebf38f94 ("block: null_blk: batched complete poll requests")
Reported-by: kernel test robot 
Signed-off-by: Jens Axboe

block: null_blk: batched complete poll requests

2021-12-03T13:36:28+00:00

Complete poll requests via blk_mq_add_to_batch() and
blk_mq_end_request_batch(), so that we can cover batched complete
code path by running null_blk test.

Meantime this way shows ~14% IOPS boost on 't/io_uring /dev/nullb0'
in my test.

Signed-off-by: Ming Lei 
Link: https://lore.kernel.org/r/20211203081703.3506020-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe

null_blk: allow zero poll queues

2021-12-03T02:57:47+00:00

There isn't any reason to not allow zero poll queues from user
viewpoint.

Also sometimes we need to compare io poll between poll mode and irq
mode, so not allowing poll queues is bad.

Fixes: 15dfc662ef31 ("null_blk: Fix handling of submit_queues and poll_queues attributes")
Cc: Shin'ichiro Kawasaki 
Signed-off-by: Ming Lei 
Link: https://lore.kernel.org/r/20211203023935.3424042-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe

block: remove the ->rq_disk field in struct request

2021-11-29T13:41:29+00:00

Just use the disk attached to the request_queue instead.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Martin K. Petersen 
Link: https://lore.kernel.org/r/20211126121802.2090656-4-hch@lst.de
Signed-off-by: Jens Axboe