linux-stable.git/drivers/block/null_blk, branch v5.16.3 Linux kernel stable tree block: null_blk: only set set->nr_maps as 3 if active poll_queues is > 0 2022-01-27T11:01:53+00:00 Ming Lei ming.lei@redhat.com 2021-12-24T01:08:31+00:00 d5d6e92af32d20582a429f87f0aeb46d031e20b1 [ Upstream commit 19768f80cf23834e65482f1667ff54192d469fee ] 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 <shinichiro.kawasaki@wdc.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Link: https://lore.kernel.org/r/20211224010831.1521805-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 19768f80cf23834e65482f1667ff54192d469fee ]

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 <shinichiro.kawasaki@wdc.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20211224010831.1521805-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
null_blk: allow zero poll queues 2022-01-27T11:01:38+00:00 Ming Lei ming.lei@redhat.com 2021-12-03T02:39:35+00:00 3ae8b70195ba637ac7a7c0ed31ced75e89da7c4b [ Upstream commit 2bfdbe8b7ebd17b5331071071a910fbabc64b436 ] 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 <shinichiro.kawasaki@wdc.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20211203023935.3424042-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 2bfdbe8b7ebd17b5331071071a910fbabc64b436 ]

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 <shinichiro.kawasaki@wdc.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20211203023935.3424042-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
null_blk: Fix handling of submit_queues and poll_queues attributes 2021-10-29T12:55:39+00:00 Shin'ichiro Kawasaki shinichiro.kawasaki@wdc.com 2021-10-29T10:39:26+00:00 15dfc662ef31a20b59097d59b0792b06770255fa 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 <yi.zhang@redhat.com> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Link: https://lore.kernel.org/r/20211029103926.845635-1-shinichiro.kawasaki@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk> 
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 <yi.zhang@redhat.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20211029103926.845635-1-shinichiro.kawasaki@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
null_blk: poll queue support 2021-10-18T20:41:36+00:00 Jens Axboe axboe@kernel.dk 2021-04-17T15:29:49+00:00 0a593fbbc245a85940ed34caa3aa1e4cb060c54b 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 <bvanassche@acm.org> Fixes-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Link: https://lore.kernel.org/r/baca710d-0f2a-16e2-60bd-b105b854e0ae@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk> 
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 <bvanassche@acm.org>
Fixes-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/baca710d-0f2a-16e2-60bd-b105b854e0ae@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: switch polling to be bio based 2021-10-18T12:17:36+00:00 Christoph Hellwig hch@lst.de 2021-10-12T11:12:24+00:00 3e08773c3841e9db7a520908cc2b136a77d275ff 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 <hch@lst.de> Tested-by: Mark Wunderlich <mark.wunderlich@intel.com> Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> 
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 <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
null_blk: add error handling support for add_disk() 2021-08-23T18:55:46+00:00 Luis Chamberlain mcgrof@kernel.org 2021-08-18T14:45:42+00:00 10e7123d5551dec0025f70e61604ab57483a6ed2 We never checked for errors on add_disk() as this function returned void. Now that this is fixed, use the shiny new error handling. The actual cleanup in case of error is already handled by the caller of null_gendisk_register(). Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20210818144542.19305-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> 
We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling. The actual cleanup in case of error is
already handled by the caller of null_gendisk_register().

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210818144542.19305-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: move some macros to blkdev.h 2021-08-12T01:40:28+00:00 Guoqing Jiang jiangguoqing@kylinos.cn 2021-07-21T02:53:15+00:00 018eca456c4b4dca56aaf1ec27f309c74d0fe246 Move them (PAGE_SECTORS_SHIFT, PAGE_SECTORS and SECTOR_MASK) to the generic header file to remove redundancy. Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn> Link: https://lore.kernel.org/r/20210721025315.1729118-1-guoqing.jiang@linux.dev Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Move them (PAGE_SECTORS_SHIFT, PAGE_SECTORS and SECTOR_MASK) to the
generic header file to remove redundancy.

Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Link: https://lore.kernel.org/r/20210721025315.1729118-1-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
null_blk: remove an unused variable assignment in null_add_dev 2021-06-30T21:34:04+00:00 Christoph Hellwig hch@lst.de 2021-06-14T06:02:31+00:00 2f43dbf3a7423ba14d827965d37fb6a56aa90009 Fix up the recent blk_alloc_disk conversion. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210614060231.3965278-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Fix up the recent blk_alloc_disk conversion.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210614060231.3965278-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
nullb: use blk_mq_alloc_disk 2021-06-11T17:54:39+00:00 Christoph Hellwig hch@lst.de 2021-06-02T06:53:35+00:00 6759b1a2013ba6f65e97f0b9444fa1cf69654f7c Use blk_mq_alloc_disk and blk_cleanup_disk to simplify the gendisk and request_queue allocation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Link: https://lore.kernel.org/r/20210602065345.355274-21-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Use blk_mq_alloc_disk and blk_cleanup_disk to simplify the gendisk and
request_queue allocation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210602065345.355274-21-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
null_blk: Fix null pointer dereference on nullb->disk on blk_cleanup_disk call 2021-06-03T15:54:33+00:00 Colin Ian King colin.king@canonical.com 2021-06-02T10:06:59+00:00 90bf3e28ef51aa3f480d2f2151813be669ba69ce The error handling on a nullb->disk allocation currently jumps to out_cleanup_disk that calls blk_cleanup_disk with a null pointer causing a null pointer dereference issue. Fix this by jumping to out_cleanup_tags instead. Addresses-Coverity: ("Dereference after null check") Fixes: 132226b301b5 ("null_blk: convert to blk_alloc_disk/blk_cleanup_disk") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210602100659.11058-1-colin.king@canonical.com Signed-off-by: Jens Axboe <axboe@kernel.dk> 
The error handling on a nullb->disk allocation currently jumps to
out_cleanup_disk that calls blk_cleanup_disk with a null pointer causing
a null pointer dereference issue. Fix this by jumping to out_cleanup_tags
instead.

Addresses-Coverity: ("Dereference after null check")
Fixes: 132226b301b5 ("null_blk: convert to blk_alloc_disk/blk_cleanup_disk")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210602100659.11058-1-colin.king@canonical.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>