linux/drivers/block/null_blk, branch v5.17

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

2021-12-24T05:05:50Z

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

2021-12-10T23:32:44Z

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

2021-12-03T13:36:28Z

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

2021-12-03T02:57:47Z

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

2021-11-29T13:41:29Z

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

block: remove GENHD_FL_EXT_DEVT

2021-11-29T13:38:35Z

All modern drivers can support extra partitions using the extended dev_t. In fact except for the ioctl method drivers never even see partitions in normal operation. So remove the GENHD_FL_EXT_DEVT and allow extra partitions for all block devices that do support partitions, and require those that do not support partitions to explicit disallow them using GENHD_FL_NO_PART. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20211122130625.1136848-12-hch@lst.de Signed-off-by: Jens Axboe

null_blk: don't suppress partitioning information

2021-11-29T13:38:31Z

This manually reverts commit 27290b469051 ("null_blk: suppress invalid partition info"). The message in that commit log can't appearch as the flag is never checked during probing, and there is no good reason to treat null_blk special in /proc/partitions. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20211122130625.1136848-9-hch@lst.de Signed-off-by: Jens Axboe

null_blk: Fix handling of submit_queues and poll_queues attributes

2021-10-29T12:55:39Z

Commit 0a593fbbc245 ("null_blk: poll queue support") introduced the poll queue feature to null_blk. After this change, null_blk device has both submit queues and poll queues, and null_map_queues() callback maps the both queues for corresponding hardware contexts. The commit also added the device configuration attribute 'poll_queues' in same manner as the existing attribute 'submit_queues'. These attributes allow to modify the numbers of queues. However, when the new values are stored to these attributes, the values are just handled only for the corresponding queue. When number of submit_queue is updated, number of poll_queue is not counted, or vice versa. This caused inconsistent number of queues and queue mapping and resulted in null-ptr-dereference. This failure was observed in blktests block/029 and block/030. To avoid the inconsistency, fix the attribute updates to care both submit_queues and poll_queues. Introduce the helper function nullb_update_nr_hw_queues() to handle stores to the both two attributes. Add poll_queues field to the struct nullb_device to track the number in same manner as submit_queues. Add two more fields prev_submit_queues and prev_poll_queues to keep the previous values before change. In case the block layer failed to update the nr_hw_queues, refer the previous values in null_map_queues() to map queues in same manner as before change. Also add poll_queues value checks in nullb_update_nr_hw_queues() and null_validate_conf(). They ensure the poll_queues value of each device is within the range from 1 to module parameter value of poll_queues. Fixes: 0a593fbbc245 ("null_blk: poll queue support") Reported-by: Yi Zhang Signed-off-by: Shin'ichiro Kawasaki Link: https://lore.kernel.org/r/20211029103926.845635-1-shinichiro.kawasaki@wdc.com Signed-off-by: Jens Axboe

null_blk: poll queue support

2021-10-18T20:41:36Z

There's currently no way to experiment with polled IO with null_blk, which seems like an oversight. This patch adds support for polled IO. We keep a list of issued IOs on submit, and then process that list when mq_ops->poll() is invoked. A new parameter is added, poll_queues. It defaults to 1 like the submit queues, meaning we'll have 1 poll queue available. Fixes-by: Bart Van Assche Fixes-by: Pavel Begunkov Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/baca710d-0f2a-16e2-60bd-b105b854e0ae@kernel.dk Signed-off-by: Jens Axboe

block: switch polling to be bio based

2021-10-18T12:17:36Z

Replace the blk_poll interface that requires the caller to keep a queue and cookie from the submissions with polling based on the bio. Polling for the bio itself leads to a few advantages: - the cookie construction can made entirely private in blk-mq.c - the caller does not need to remember the request_queue and cookie separately and thus sidesteps their lifetime issues - keeping the device and the cookie inside the bio allows to trivially support polling BIOs remapping by stacking drivers - a lot of code to propagate the cookie back up the submission path can be removed entirely. Signed-off-by: Christoph Hellwig Tested-by: Mark Wunderlich Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de Signed-off-by: Jens Axboe