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Such code are not even compiled since they are inside marco "#if 0".
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Paolo Valente <paolo.valente@unimore.it>
Link: https://lore.kernel.org/r/20221102022542.3621219-5-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Just make the code a litter cleaner by removing the unnecessary
variable 'sd'.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Paolo Valente <paolo.valente@unimore.it>
Link: https://lore.kernel.org/r/20221102022542.3621219-4-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Current code is a bit ugly and hard to read.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Paolo Valente <paolo.valente@unimore.it>
Link: https://lore.kernel.org/r/20221102022542.3621219-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
After the patch "block, bfq: cleanup bfq_weights_tree add/remove apis"),
the local variable 'bfqd' is not used anymore, thus remove it.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20221102022542.3621219-2-yukuai1@huaweicloud.com
Fixes: afdba1461262 ("block, bfq: cleanup bfq_weights_tree add/remove apis")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We only need a max queue depth for every iolatency to limit the inflight io
number. Replace struct rq_depth with unsigned int to simplfy "struct
iolatency_grp" and save memory.
Signed-off-by: Kemeng Shi <shikemeng@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20221018111240.22612-4-shikemeng@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Default queue depth of iolatency_grp is unlimited, so we scale down
quickly(once by half) in scale_cookie_change. Remove the "subtract
1/16th" part which is not the truth and add the actual way we
scale down.
Signed-off-by: Kemeng Shi <shikemeng@huawei.com>
Link: https://lore.kernel.org/r/20221018111240.22612-3-shikemeng@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Function blkcg_iolatency_throttle will make sure blkg->parent is not
NULL before calls check_scale_change. And function check_scale_change
is only called in blkcg_iolatency_throttle.
Signed-off-by: Kemeng Shi <shikemeng@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20221018111240.22612-2-shikemeng@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Split an elevator_disable helper from elevator_switch for the case where
we want to switch to no scheduler at all. This includes removing the
pointless elevator_switch_mq helper and removing the switch to no
schedule logic from blk_mq_init_sched.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221030100714.876891-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Checking for the required features in the callers simplifies the code
quite a bit, so do that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221030100714.876891-7-hch@lst.de
[axboe: adjust for dropping patch 1, use __elevator_find()]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Use eq for the elevator_queue as done elsewhere. This frees e to be used
for the loop iterator instead of the odd __ prefix. In addition rename
elv to cur to make it more clear it is the currently selected elevator.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221030100714.876891-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If the tag_set has BLK_MQ_F_NO_SCHED flag set we will never show any
scheduler, so exit early.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221030100714.876891-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Do the request_module and repeated lookup in the only caller that cares,
pick a saner name that explains where are actually doing a lookup and
use a sane calling conventions that passes the queue first.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221030100714.876891-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
It's the same with bfq_weights_tree_remove() now.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20220916071942.214222-7-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The 'bfq_data' and 'rb_root_cached' can both be accessed through
'bfq_queue', thus only pass 'bfq_queue' as parameter.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20220916071942.214222-6-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now that root group is counted into 'num_groups_with_pending_reqs',
'num_groups_with_pending_reqs > 0' is always true in
bfq_asymmetric_scenario(). Thus change the condition to '> 1'.
On the other hand, this change can enable concurrent sync io if only
one group is activated.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20220916071942.214222-5-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently, bfq can't handle sync io concurrently as long as they
are not issued from root group. This is because
'bfqd->num_groups_with_pending_reqs > 0' is always true in
bfq_asymmetric_scenario().
The way that bfqg is counted into 'num_groups_with_pending_reqs':
Before this patch:
1) root group will never be counted.
2) Count if bfqg or it's child bfqgs have pending requests.
3) Don't count if bfqg and it's child bfqgs complete all the requests.
After this patch:
1) root group is counted.
2) Count if bfqg have pending requests.
3) Don't count if bfqg complete all the requests.
With this change, the occasion that only one group is activated can be
detected, and next patch will support concurrent sync io in the
occasion.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20220916071942.214222-4-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Prepare to refactor the counting of 'num_groups_with_pending_reqs'.
Add a counter in bfq_group, update it while tracking if bfqq have pending
requests and when bfq_bfqq_move() is called.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20220916071942.214222-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If entity belongs to bfqq, then entity->in_groups_with_pending_reqs
is not used currently. This patch use it to track if bfqq has pending
requests through callers of weights_tree insertion and removal.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20220916071942.214222-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_mq_flush_plug_list() empties ->mq_list and request we'd peeked there
before that call is gone; in any case, we are not dealing with a mix
of requests for different queues now - there's no requests left in the
plug.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is a kmemleak caused by modprobe null_blk.ko
unreferenced object 0xffff8881acb1f000 (size 1024):
comm "modprobe", pid 836, jiffies 4294971190 (age 27.068s)
hex dump (first 32 bytes):
00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
ff ff ff ff ff ff ff ff 00 53 99 9e ff ff ff ff .........S......
backtrace:
[<000000004a10c249>] kmalloc_node_trace+0x22/0x60
[<00000000648f7950>] blk_mq_alloc_and_init_hctx+0x289/0x350
[<00000000af06de0e>] blk_mq_realloc_hw_ctxs+0x2fe/0x3d0
[<00000000e00c1872>] blk_mq_init_allocated_queue+0x48c/0x1440
[<00000000d16b4e68>] __blk_mq_alloc_disk+0xc8/0x1c0
[<00000000d10c98c3>] 0xffffffffc450d69d
[<00000000b9299f48>] 0xffffffffc4538392
[<0000000061c39ed6>] do_one_initcall+0xd0/0x4f0
[<00000000b389383b>] do_init_module+0x1a4/0x680
[<0000000087cf3542>] load_module+0x6249/0x7110
[<00000000beba61b8>] __do_sys_finit_module+0x140/0x200
[<00000000fdcfff51>] do_syscall_64+0x35/0x80
[<000000003c0f1f71>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
That is because q->ma_ops is set to NULL before blk_release_queue is
called.
blk_mq_init_queue_data
blk_mq_init_allocated_queue
blk_mq_realloc_hw_ctxs
for (i = 0; i < set->nr_hw_queues; i++) {
old_hctx = xa_load(&q->hctx_table, i);
if (!blk_mq_alloc_and_init_hctx(.., i, ..)) [1]
if (!old_hctx)
break;
xa_for_each_start(&q->hctx_table, j, hctx, j)
blk_mq_exit_hctx(q, set, hctx, j); [2]
if (!q->nr_hw_queues) [3]
goto err_hctxs;
err_exit:
q->mq_ops = NULL; [4]
blk_put_queue
blk_release_queue
if (queue_is_mq(q)) [5]
blk_mq_release(q);
[1]: blk_mq_alloc_and_init_hctx failed at i != 0.
[2]: The hctxs allocated by [1] are moved to q->unused_hctx_list and
will be cleaned up in blk_mq_release.
[3]: q->nr_hw_queues is 0.
[4]: Set q->mq_ops to NULL.
[5]: queue_is_mq returns false due to [4]. And blk_mq_release
will not be called. The hctxs in q->unused_hctx_list are leaked.
To fix it, call blk_release_queue in exception path.
Fixes: 2f8f1336a48b ("blk-mq: always free hctx after request queue is freed")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20221031031242.94107-1-chenjun102@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The calling relationship in blk_mq_destroy_queue() is as follows:
blk_mq_destroy_queue()
...
-> blk_queue_start_drain()
-> blk_freeze_queue_start() <- called
...
-> blk_freeze_queue()
-> blk_freeze_queue_start() <- called again
-> blk_mq_freeze_queue_wait()
...
So there is a redundant call to blk_freeze_queue_start().
Replace blk_freeze_queue() with blk_mq_freeze_queue_wait() to avoid the
redundant call.
Signed-off-by: Jinlong Chen <nickyc975@zju.edu.cn>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221030083212.1251255-1-nickyc975@zju.edu.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
kmemleak reported memory leaks in device_add_disk():
kmemleak: 3 new suspected memory leaks
unreferenced object 0xffff88800f420800 (size 512):
comm "modprobe", pid 4275, jiffies 4295639067 (age 223.512s)
hex dump (first 32 bytes):
04 00 00 00 08 00 00 00 01 00 00 00 00 00 00 00 ................
00 e1 f5 05 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000d3662699>] kmalloc_trace+0x26/0x60
[<00000000edc7aadc>] wbt_init+0x50/0x6f0
[<0000000069601d16>] wbt_enable_default+0x157/0x1c0
[<0000000028fc393f>] blk_register_queue+0x2a4/0x420
[<000000007345a042>] device_add_disk+0x6fd/0xe40
[<0000000060e6aab0>] nbd_dev_add+0x828/0xbf0 [nbd]
...
It is because the memory allocated in wbt_enable_default() is not
released in device_add_disk() error path.
Normally, these memory are freed in:
del_gendisk()
rq_qos_exit()
rqos->ops->exit(rqos);
wbt_exit()
So rq_qos_exit() is called to free the rq_wb memory for wbt_init().
However in the error path of device_add_disk(), only
blk_unregister_queue() is called and make rq_wb memory leaked.
Add rq_qos_exit() to the error path to fix it.
Fixes: 83cbce957446 ("block: add error handling for device_add_disk / add_disk")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221029071355.35462-1-chenzhongjin@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The only caller that needs queue_is_mq check is del_gendisk, so move the
check into it.
Signed-off-by: Jinlong Chen <nickyc975@zju.edu.cn>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221030094730.1275463-1-nickyc975@zju.edu.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
David Jeffery found one double ->queue_rq() issue, so far it can
be triggered in VM use case because of long vmexit latency or preempt
latency of vCPU pthread or long page fault in vCPU pthread, then block
IO req could be timed out before queuing the request to hardware but after
calling blk_mq_start_request() during ->queue_rq(), then timeout handler
may handle it by requeue, then double ->queue_rq() is caused, and kernel
panic.
So far, it is driver's responsibility to cover the race between timeout
and completion, so it seems supposed to be solved in driver in theory,
given driver has enough knowledge.
But it is really one common problem, lots of driver could have similar
issue, and could be hard to fix all affected drivers, even it isn't easy
for driver to handle the race. So David suggests this patch by draining
in-progress ->queue_rq() for solving this issue.
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: virtualization@lists.linux-foundation.org
Cc: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20221026051957.358818-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'block-6.1-2022-10-28' of git://git.kernel.dk/linux
Pull block fixes from Jens Axboe:
- NVMe pull request via Christoph:
- make the multipath dma alignment match the non-multipath one
(Keith Busch)
- fix a bogus use of sg_init_marker() (Nam Cao)
- fix circulr locking in nvme-tcp (Sagi Grimberg)
- Initialization fix for requests allocated via the special hw queue
allocator (John)
- Fix for a regression added in this release with the batched
completions of end_io backed requests (Ming)
- Error handling leak fix for rbd (Yang)
- Error handling leak fix for add_disk() failure (Yu)
* tag 'block-6.1-2022-10-28' of git://git.kernel.dk/linux:
blk-mq: Properly init requests from blk_mq_alloc_request_hctx()
blk-mq: don't add non-pt request with ->end_io to batch
rbd: fix possible memory leak in rbd_sysfs_init()
nvme-multipath: set queue dma alignment to 3
nvme-tcp: fix possible circular locking when deleting a controller under memory pressure
nvme-tcp: replace sg_init_marker() with sg_init_table()
block: fix memory leak for elevator on add_disk failure
Function blk_mq_alloc_request_hctx() is missing zeroing/init of rq->bio,
biotail, __sector, and __data_len members, which blk_mq_alloc_request()
has, so duplicate what we do in blk_mq_alloc_request().
Fixes: 1f5bd336b9150 ("blk-mq: add blk_mq_alloc_request_hctx")
Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/1666780513-121650-1-git-send-email-john.garry@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Document which functions do not modify the queue limits.
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20221025191755.1711437-3-bvanassche@acm.org
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The fact that blk_mq_destroy_queue also drops a queue reference leads
to various places having to grab an extra reference. Move the call to
blk_put_queue into the callers to allow removing the extra references.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20221018135720.670094-2-hch@lst.de
[axboe: fix fabrics_q vs admin_q conflict in nvme core.c]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The current reference management logic of io scheduler modules contains
refcnt problems. For example, blk_mq_init_sched may fail before or after
the calling of e->ops.init_sched. If it fails before the calling, it does
nothing to the reference to the io scheduler module. But if it fails after
the calling, it releases the reference by calling kobject_put(&eq->kobj).
As the callers of blk_mq_init_sched can't know exactly where the failure
happens, they can't handle the reference to the io scheduler module
properly: releasing the reference on failure results in double-release if
blk_mq_init_sched has released it, and not releasing the reference results
in ghost reference if blk_mq_init_sched did not release it either.
The same problem also exists in io schedulers' init_sched implementations.
We can address the problem by adding releasing statements to the error
handling procedures of blk_mq_init_sched and init_sched implementations.
But that is counterintuitive and requires modifications to existing io
schedulers.
Instead, We make elevator_alloc get the io scheduler module references
that will be released by elevator_release. And then, we match each
elevator_get with an elevator_put. Therefore, each reference to an io
scheduler module explicitly has its own getter and releaser, and we no
longer need to worry about the refcnt problems.
The bugs and the patch can be validated with tools here:
https://github.com/nickyc975/linux_elv_refcnt_bug.git
[hch: split out a few bits into separate patches, use a non-try
module_get in elevator_alloc]
Signed-off-by: Jinlong Chen <nickyc975@zju.edu.cn>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221020064819.1469928-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No need to find the actual elevator_type struct for this comparism,
the name is all that is needed.
Signed-off-by: Jinlong Chen <nickyc975@zju.edu.cn>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221020064819.1469928-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The stripped name should also be used for the none check. To do so
strip it in the caller and pass in the sanitized name. Drop the pointless
__ prefix in the function name while we're at it.
Based on a patch from Jinlong Chen <nickyc975@zju.edu.cn>.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221020064819.1469928-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Make sure we have helpers for all relevant module refcount operations on
the elevator_type in elevator.h, and use them. Move the call to the get
helper in blk_mq_elv_switch_none a bit so that it is obvious with a less
verbose comment.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221020064819.1469928-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit b5dc5d4d1f4f ("block,bfq: Disable writeback throttling") tries to
disable wbt for bfq, it's done by calling wbt_disable_default() in
bfq_init_queue(). However, wbt is still enabled if default elevator is
bfq:
device_add_disk
elevator_init_mq
bfq_init_queue
wbt_disable_default -> done nothing
blk_register_queue
wbt_enable_default -> wbt is enabled
Fix the problem by adding a new flag ELEVATOR_FLAG_DISBALE_WBT, bfq
will set the flag in bfq_init_queue, and following wbt_enable_default()
won't enable wbt while the flag is set.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221019121518.3865235-7-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There are only one flag to indicate that elevator is registered currently,
prepare to add a flag to disable wbt if default elevator is bfq.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221019121518.3865235-6-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently, if wbt is initialized and then disabled by
wbt_disable_default(), sysfs will still show valid wbt_lat_usec, which
will confuse users that wbt is still enabled.
This patch shows wbt_lat_usec as zero if it's disabled.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reported-and-tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221019121518.3865235-5-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently, if user disable wbt through sysfs, 'enable_state' will be
'WBT_STATE_ON_MANUAL', which will be confusing. Add a new state
'WBT_STATE_OFF_MANUAL' to cover that case.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221019121518.3865235-4-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
"elevator_queue *e" is already declared and initialized in the beginning
of elv_unregister_queue().
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20221019121518.3865235-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
'ioc->params' is updated in ioc_refresh_params(), which is proteced by
'ioc->lock', however, ioc_timer_fn() read params outside the lock.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20221012094035.390056-5-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This won't cause any severe problem currently, however, this doesn't
seems appropriate:
1) 'ioc->params' is read from multiple places without holding
'ioc->lock', unexpected value might be read if writing it concurrently.
2) If configuration is changed while io is throttling, the functionality
might be affected. For example, if module params is updated and cost
becomes smaller, waiting for timer that is caculated under old
configuration is not appropriate.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20221012094035.390056-4-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
ioc_qos_write() and ioc_cost_model_write() are the same:
1) hold lock to read 'ioc->params' to local variable;
2) update params to local variable without lock;
3) hold lock to write local variable to 'ioc->params';
In theroy, if user updates params concurrenty, the params might be lost:
t1: update params a t2: update params b
spin_lock_irq(&ioc->lock);
memcpy(qos, ioc->params.qos, sizeof(qos))
spin_unlock_irq(&ioc->lock);
qos[a] = xxx;
spin_lock_irq(&ioc->lock);
memcpy(qos, ioc->params.qos, sizeof(qos))
spin_unlock_irq(&ioc->lock);
qos[b] = xxx;
spin_lock_irq(&ioc->lock);
memcpy(ioc->params.qos, qos, sizeof(qos));
ioc_refresh_params(ioc, true);
spin_unlock_irq(&ioc->lock);
spin_lock_irq(&ioc->lock);
// updates of a will be lost
memcpy(ioc->params.qos, qos, sizeof(qos));
ioc_refresh_params(ioc, true);
spin_unlock_irq(&ioc->lock);
Althrough this is not common case, the problem can by fixed easily by
holding the lock through the read, update, write process.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20221012094035.390056-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit b5dc5d4d1f4f ("block,bfq: Disable writeback throttling") disable
wbt for bfq, because different write-throttling heuristics should not
work together.
For the same reason, wbt and iocost should not work together as well,
unless admin really want to do that, dispite that performance is
affected.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20221012094035.390056-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The default elevator is allocated in the beginning of device_add_disk(),
however, it's not freed in the following error path.
Fixes: 50e34d78815e ("block: disable the elevator int del_gendisk")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20221022021615.2756171-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
bio_put() with REQ_ALLOC_CACHE assumes that it's executed not from
an irq context. Let's add a warning if the invariant is not respected,
especially since there is a couple of places removing REQ_POLLED by hand
without also clearing REQ_ALLOC_CACHE.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/558d78313476c4e9c233902efa0092644c3d420a.1666122465.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
it defined in d0edc2473be9d, but there's nowhere to use it,
so remove it.
Signed-off-by: Yuwei Guan <Yuwei.Guan@zeekrlife.com>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20221018030139.159-1-Yuwei.Guan@zeekrlife.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Our syzkaller report a null pointer dereference, root cause is
following:
__blk_mq_alloc_map_and_rqs
set->tags[hctx_idx] = blk_mq_alloc_map_and_rqs
blk_mq_alloc_map_and_rqs
blk_mq_alloc_rqs
// failed due to oom
alloc_pages_node
// set->tags[hctx_idx] is still NULL
blk_mq_free_rqs
drv_tags = set->tags[hctx_idx];
// null pointer dereference is triggered
blk_mq_clear_rq_mapping(drv_tags, ...)
This is because commit 63064be150e4 ("blk-mq:
Add blk_mq_alloc_map_and_rqs()") merged the two steps:
1) set->tags[hctx_idx] = blk_mq_alloc_rq_map()
2) blk_mq_alloc_rqs(..., set->tags[hctx_idx])
into one step:
set->tags[hctx_idx] = blk_mq_alloc_map_and_rqs()
Since tags is not initialized yet in this case, fix the problem by
checking if tags is NULL pointer in blk_mq_clear_rq_mapping().
Fixes: 63064be150e4 ("blk-mq: Add blk_mq_alloc_map_and_rqs()")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20221011142253.4015966-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
