[ Upstream commit 99dc422335d8b2bd4d105797241d3e715bae90e9 ]
Currently, io_ticks is accounted based on sampling, specifically
update_io_ticks() will always account io_ticks by 1 jiffies from
bdev_start_io_acct()/blk_account_io_start(), and the result can be
inaccurate, for example(HZ is 250):
Test script:
fio -filename=/dev/sda -bs=4k -rw=write -direct=1 -name=test -thinktime=4ms
Test result: util is about 90%, while the disk is really idle.
This behaviour is introduced by commit 5b18b5a737 ("block: delete
part_round_stats and switch to less precise counting"), however, there
was a key point that is missed that this patch also improve performance
a lot:
Before the commit:
part_round_stats:
if (part->stamp != now)
stats |= 1;
part_in_flight()
-> there can be lots of task here in 1 jiffies.
part_round_stats_single()
__part_stat_add()
part->stamp = now;
After the commit:
update_io_ticks:
stamp = part->bd_stamp;
if (time_after(now, stamp))
if (try_cmpxchg())
__part_stat_add()
-> only one task can reach here in 1 jiffies.
Hence in order to account io_ticks precisely, we only need to know if
there are IO inflight at most once in one jiffies. Noted that for
rq-based device, iterating tags should not be used here because
'tags->lock' is grabbed in blk_mq_find_and_get_req(), hence
part_stat_lock_inc/dec() and part_in_flight() is used to trace inflight.
The additional overhead is quite little:
- per cpu add/dec for each IO for rq-based device;
- per cpu sum for each jiffies;
And it's verified by null-blk that there are no performance degration
under heavy IO pressure.
Fixes: 5b18b5a737 ("block: delete part_round_stats and switch to less precise counting")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240509123717.3223892-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 06965037ce942500c1ce3aa29ca217093a9c5720 ]
There is only one caller for __blk_account_io_done(), the function
is small enough to fit in its caller blk_account_io_done().
Remove the function and opencode in the its caller
blk_account_io_done().
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20230327073427.4403-2-kch@nvidia.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 99dc422335d8 ("block: support to account io_ticks precisely")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e165fb4dd6985b37215178e514a2e09dab8fef14 ]
There is only one caller for __blk_account_io_start(), the function
is small enough to fit in its caller blk_account_io_start().
Remove the function and opencode in the its caller
blk_account_io_start().
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20230327073427.4403-2-kch@nvidia.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 99dc422335d8 ("block: support to account io_ticks precisely")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit beaa51b36012fad5a4d3c18b88a617aea7a9b96d ]
UBSAN catches undefined behavior in blk-iocost, where sometimes
iocg->delay is shifted right by a number that is too large,
resulting in undefined behavior on some architectures.
[ 186.556576] ------------[ cut here ]------------
UBSAN: shift-out-of-bounds in block/blk-iocost.c:1366:23
shift exponent 64 is too large for 64-bit type 'u64' (aka 'unsigned long long')
CPU: 16 PID: 0 Comm: swapper/16 Tainted: G S E N 6.9.0-0_fbk700_debug_rc2_kbuilder_0_gc85af715cac0 #1
Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A23 12/08/2020
Call Trace:
<IRQ>
dump_stack_lvl+0x8f/0xe0
__ubsan_handle_shift_out_of_bounds+0x22c/0x280
iocg_kick_delay+0x30b/0x310
ioc_timer_fn+0x2fb/0x1f80
__run_timer_base+0x1b6/0x250
...
Avoid that undefined behavior by simply taking the
"delay = 0" branch if the shift is too large.
I am not sure what the symptoms of an undefined value
delay will be, but I suspect it could be more than a
little annoying to debug.
Signed-off-by: Rik van Riel <riel@surriel.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Jens Axboe <axboe@kernel.dk>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20240404123253.0f58010f@imladris.surriel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 22d24a544b0d49bbcbd61c8c0eaf77d3c9297155 ]
There is no check for overflow of 'start + len' in blk_ioctl_discard().
Hung task occurs if submit an discard ioctl with the following param:
start = 0x80000000000ff000, len = 0x8000000000fff000;
Add the overflow validation now.
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240329012319.2034550-1-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 93f52fbeaf4b676b21acfe42a5152620e6770d02 ]
The expression dst->nr_samples + src->nr_samples may
have zero value on overflow. It is necessary to add
a check to avoid division by zero.
Found by Linux Verification Center (linuxtesting.org) with Svace.
Signed-off-by: Roman Smirnov <r.smirnov@omp.ru>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/20240305134509.23108-1-r.smirnov@omp.ru
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 55251fbdf0146c252ceff146a1bb145546f3e034 upstream.
This reverts commit 748dc0b65ec2b4b7b3dbd7befcc4a54fdcac7988.
Partial zone append completions cannot be supported as there is no
guarantees that the fragmented data will be written sequentially in the
same manner as with a full command. Commit 748dc0b65ec2 ("block: fix
partial zone append completion handling in req_bio_endio()") changed
req_bio_endio() to always advance a partially failed BIO by its full
length, but this can lead to incorrect accounting. So revert this
change and let low level device drivers handle this case by always
failing completely zone append operations. With this revert, users will
still see an IO error for a partially completed zone append BIO.
Fixes: 748dc0b65ec2 ("block: fix partial zone append completion handling in req_bio_endio()")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240328004409.594888-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e5c0ca13659e9d18f53368d651ed7e6e433ec1cf upstream.
Chuck reported [1] an IO hang problem on NFS exports that reside on SATA
devices and bisected to commit 615939a2ae73 ("blk-mq: defer to the normal
submission path for post-flush requests").
We analysed the IO hang problem, found there are two postflush requests
waiting for each other.
The first postflush request completed the REQ_FSEQ_DATA sequence, so go to
the REQ_FSEQ_POSTFLUSH sequence and added in the flush pending list, but
failed to blk_kick_flush() because of the second postflush request which
is inflight waiting in scheduler queue.
The second postflush waiting in scheduler queue can't be dispatched because
the first postflush hasn't released scheduler resource even though it has
completed by itself.
Fix it by releasing scheduler resource when the first postflush request
completed, so the second postflush can be dispatched and completed, then
make blk_kick_flush() succeed.
While at it, remove the check for e->ops.finish_request, as all
schedulers set that. Reaffirm this requirement by adding a WARN_ON_ONCE()
at scheduler registration time, just like we do for insert_requests and
dispatch_request.
[1] https://lore.kernel.org/all/7A57C7AE-A51A-4254-888B-FE15CA21F9E9@oracle.com/
Link: https://lore.kernel.org/linux-block/20230819031206.2744005-1-chengming.zhou@linux.dev/
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202308172100.8ce4b853-oliver.sang@intel.com
Fixes: 615939a2ae73 ("blk-mq: defer to the normal submission path for post-flush requests")
Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20230813152325.3017343-1-chengming.zhou@linux.dev
[axboe: folded in incremental fix and added tags]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[bvanassche: changed RQF_USE_SCHED into RQF_ELVPRIV; restored the
finish_request pointer check before calling finish_request and removed
the new warning from the elevator code. This patch fixes an I/O hang
when submitting a REQ_FUA request to a request queue for a zoned block
device for which FUA has been disabled (QUEUE_FLAG_FUA is not set).]
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 256aab46e31683d76d45ccbedc287b4d3f3e322b ]
The code "max(1U, 3 * (1U << shift) / 4)" comes from the Kyber I/O
scheduler. The Kyber I/O scheduler maintains one internal queue per hwq
and hence derives its async_depth from the number of hwq tags. Using
this approach for the mq-deadline scheduler is wrong since the
mq-deadline scheduler maintains one internal queue for all hwqs
combined. Hence this revert.
Cc: stable@vger.kernel.org
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Cc: Zhiguo Niu <Zhiguo.Niu@unisoc.com>
Fixes: d47f9717e5cf ("block/mq-deadline: use correct way to throttling write requests")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240313214218.1736147-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c8f6f88d25929ad2f290b428efcae3b526f3eab0 ]
Device mapper may create a non-zoned mapped device out of a zoned device
(e.g., the dm-zoned target). In such case, some queue limit such as the
max_zone_append_sectors and zone_write_granularity endup being non zero
values for a block device that is not zoned. Avoid this by clearing
these limits in blk_stack_limits() when the stacked zoned limit is
false.
Fixes: 3093a47972 ("block: inherit the zoned characteristics in blk_stack_limits")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240222131724.1803520-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5429c8de56f6b2bd8f537df3a1e04e67b9c04282 ]
The SED Opal response parsing function response_parse() does not
handle the case of an empty atom in the response. This causes
the entry count to be too high and the response fails to be
parsed. Recognizing, but ignoring, empty atoms allows response
handling to succeed.
Signed-off-by: Greg Joyce <gjoyce@linux.ibm.com>
Link: https://lore.kernel.org/r/20240216210417.3526064-2-gjoyce@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 748dc0b65ec2b4b7b3dbd7befcc4a54fdcac7988 ]
Partial completions of zone append request is not allowed but if a zone
append completion indicates a number of completed bytes different from
the original BIO size, only the BIO status is set to error. This leads
to bio_advance() not setting the BIO size to 0 and thus to not call
bio_endio() at the end of req_bio_endio().
Make sure a partially completed zone append is failed and completed
immediately by forcing the completed number of bytes (nbytes) to be
equal to the BIO size, thus ensuring that bio_endio() is called.
Fixes: 297db73184 ("block: fix req_bio_endio append error handling")
Cc: stable@kernel.vger.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240110092942.442334-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 33391eecd63158536fb5257fee5be3a3bdc30e3c upstream.
We ran into an issue where a production workload would randomly grind to
a halt and not continue until the pending IO had timed out. This turned
out to be a complicated interaction between queue freezing and polled
IO:
1) You have an application that does polled IO. At any point in time,
there may be polled IO pending.
2) You have a monitoring application that issues a passthrough command,
which is marked with side effects such that it needs to freeze the
queue.
3) Passthrough command is started, which calls blk_freeze_queue_start()
on the device. At this point the queue is marked frozen, and any
attempt to enter the queue will fail (for non-blocking) or block.
4) Now the driver calls blk_mq_freeze_queue_wait(), which will return
when the queue is quiesced and pending IO has completed.
5) The pending IO is polled IO, but any attempt to poll IO through the
normal iocb_bio_iopoll() -> bio_poll() will fail when it gets to
bio_queue_enter() as the queue is frozen. Rather than poll and
complete IO, the polling threads will sit in a tight loop attempting
to poll, but failing to enter the queue to do so.
The end result is that progress for either application will be stalled
until all pending polled IO has timed out. This causes obvious huge
latency issues for the application doing polled IO, but also long delays
for passthrough command.
Fix this by treating queue enter for polled IO just like we do for
timeouts. This allows quick quiesce of the queue as we still poll and
complete this IO, while still disallowing queueing up new IO.
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2a427b49d02995ea4a6ff93a1432c40fa4d36821 ]
When iocg_kick_delay() is called from a CPU different than the one which set
the delay, @now may be in the past of @iocg->delay_at leading to the
following warning:
UBSAN: shift-out-of-bounds in block/blk-iocost.c:1359:23
shift exponent 18446744073709 is too large for 64-bit type 'u64' (aka 'unsigned long long')
...
Call Trace:
<TASK>
dump_stack_lvl+0x79/0xc0
__ubsan_handle_shift_out_of_bounds+0x2ab/0x300
iocg_kick_delay+0x222/0x230
ioc_rqos_merge+0x1d7/0x2c0
__rq_qos_merge+0x2c/0x80
bio_attempt_back_merge+0x83/0x190
blk_attempt_plug_merge+0x101/0x150
blk_mq_submit_bio+0x2b1/0x720
submit_bio_noacct_nocheck+0x320/0x3e0
__swap_writepage+0x2ab/0x9d0
The underflow itself doesn't really affect the behavior in any meaningful
way; however, the past timestamp may exaggerate the delay amount calculated
later in the code, which shouldn't be a material problem given the nature of
the delay mechanism.
If @now is in the past, this CPU is racing another CPU which recently set up
the delay and there's nothing this CPU can contribute w.r.t. the delay.
Let's bail early from iocg_kick_delay() in such cases.
Reported-by: Breno Leitão <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 5160a5a53c ("blk-iocost: implement delay adjustment hysteresis")
Link: https://lore.kernel.org/r/ZVvc9L_CYk5LO1fT@slm.duckdns.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5266caaf5660529e3da53004b8b7174cab6374ed ]
In blk_mq_mark_tag_wait(), __add_wait_queue() may be re-ordered
with the following blk_mq_get_driver_tag() in case of getting driver
tag failure.
Then in __sbitmap_queue_wake_up(), waitqueue_active() may not observe
the added waiter in blk_mq_mark_tag_wait() and wake up nothing, meantime
blk_mq_mark_tag_wait() can't get driver tag successfully.
This issue can be reproduced by running the following test in loop, and
fio hang can be observed in < 30min when running it on my test VM
in laptop.
modprobe -r scsi_debug
modprobe scsi_debug delay=0 dev_size_mb=4096 max_queue=1 host_max_queue=1 submit_queues=4
dev=`ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter*/host*/target*/*/block/* | head -1 | xargs basename`
fio --filename=/dev/"$dev" --direct=1 --rw=randrw --bs=4k --iodepth=1 \
--runtime=100 --numjobs=40 --time_based --name=test \
--ioengine=libaio
Fix the issue by adding one explicit barrier in blk_mq_mark_tag_wait(), which
is just fine in case of running out of tag.
Cc: Jan Kara <jack@suse.cz>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Reported-by: Changhui Zhong <czhong@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20240112122626.4181044-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1b151e2435fc3a9b10c8946c6aebe9f3e1938c55 upstream.
The special casing was originally added in pre-git history; reproducing
the commit log here:
> commit a318a92567d77
> Author: Andrew Morton <akpm@osdl.org>
> Date: Sun Sep 21 01:42:22 2003 -0700
>
> [PATCH] Speed up direct-io hugetlbpage handling
>
> This patch short-circuits all the direct-io page dirtying logic for
> higher-order pages. Without this, we pointlessly bounce BIOs up to
> keventd all the time.
In the last twenty years, compound pages have become used for more than
just hugetlb. Rewrite these functions to operate on folios instead
of pages and remove the special case for hugetlbfs; I don't think
it's needed any more (and if it is, we can put it back in as a call
to folio_test_hugetlb()).
This was found by inspection; as far as I can tell, this bug can lead
to pages used as the destination of a direct I/O read not being marked
as dirty. If those pages are then reclaimed by the MM without being
dirtied for some other reason, they won't be written out. Then when
they're faulted back in, they will not contain the data they should.
It'll take a pretty unusual setup to produce this problem with several
races all going the wrong way.
This problem predates the folio work; it could for example have been
triggered by mmaping a THP in tmpfs and using that as the target of an
O_DIRECT read.
Fixes: 800d8c63b2 ("shmem: add huge pages support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 7b4f36cd22a65b750b4cb6ac14804fb7d6e6c67d ]
q_usage_counter is the only thing preventing us from the limits changing
under us in __bio_split_to_limits, but blk_mq_submit_bio doesn't hold
it while calling into it.
Move the splitting inside the region where we know we've got a queue
reference. Ideally this could still remain a shared section of code, but
let's keep the fix simple and defer any refactoring here to later.
Reported-by: Christoph Hellwig <hch@lst.de>
Fixes: 900e080752 ("block: move queue enter logic into blk_mq_submit_bio()")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6f64f866aa1ae6975c95d805ed51d7e9433a0016 upstream.
Before calling add partition or resize partition, there is no check
on whether the length is aligned with the logical block size.
If the logical block size of the disk is larger than 512 bytes,
then the partition size maybe not the multiple of the logical block size,
and when the last sector is read, bio_truncate() will adjust the bio size,
resulting in an IO error if the size of the read command is smaller than
the logical block size.If integrity data is supported, this will also
result in a null pointer dereference when calling bio_integrity_free.
Cc: <stable@vger.kernel.org>
Signed-off-by: Min Li <min15.li@samsung.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230629142517.121241-1-min15.li@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 4c434392c4777881d01beada6701eff8c76b43fe ]
'first_minor' represents the starting minor number of disks, and
'minors' represents the number of partitions in the device. Neither
of them can be greater than MINORMASK + 1.
Commit e338924bd0 ("block: check minor range in device_add_disk()")
only added the check of 'first_minor + minors'. However, their sum might
be less than MINORMASK but their values are wrong. Complete the checks now.
Fixes: e338924bd0 ("block: check minor range in device_add_disk()")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231219075942.840255-1-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5fa3d1a00c2d4ba14f1300371ad39d5456e890d7 ]
On the error path of device_add_disk(), device's memalloc_noio flag was
set but not cleared. As the comment of pm_runtime_set_memalloc_noio(),
"The function should be called between device_add() and device_del()".
Clear this flag before device_del() now.
Fixes: 25e823c8c3 ("block/genhd.c: apply pm_runtime_set_memalloc_noio on block devices")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231211075356.1839282-1-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
