64K PAGE_SIZE is popular on ARM64 or other ARCHs, and 64K has been big
enough to break some devices probably, so change the logic to split bio
if the only bvec's length is > SZ_4K instead of PAGE_SIZE.
Fixes: fa53228721 (block: avoid blk_bio_segment_split for small I/O operations)
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Some device may set segment boundary as PAGE_SIZE - 1. If the bvec
crosses pages, and meantime its length is <= PAGE_SIZE, we still need
to split the bvec into 2 segments.
Fixes this issue by still splitting bio if the single bvec crosses
pages.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: fa53228721 (block: avoid blk_bio_segment_split for small I/O operations)
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blkg_rwstat is now only used by bfq-iosched and blk-throtl when on
cgroup1. Let's move it into its own files and gate it behind a config
option.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk-cgroup has been using blkg_rwstat to track basic IO stats.
Unfortunately, reading recursive stats scales badly as itinvolves
walking all descendants. On systems with a huge number of cgroups
(dead or alive), this can lead to substantial CPU cost when reading IO
stats.
This patch reimplements basic IO stats using cgroup rstat which uses
more memory but makes recursive stat reading O(# descendants which
have been active since last reading) instead of O(# descendants).
* blk-cgroup core no longer uses sync/async stats. Introduce new stat
enums - BLKG_IOSTAT_{READ|WRITE|DISCARD}.
* Add blkg_iostat[_set] which encapsulates byte and io stats, last
values for propagation delta calculation and u64_stats_sync for
correctness on 32bit archs.
* Update the new percpu stat counters directly and implement
blkcg_rstat_flush() to implement propagation.
* blkg_print_stat() can now bring the stats up to date by calling
cgroup_rstat_flush() and print them instead of directly summing up
all descendants.
* It now allocates 96 bytes per cpu. It used to be 40 bytes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Dan Schatzberg <dschatzberg@fb.com>
Cc: Daniel Xu <dlxu@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When used on cgroup1, blk-throtl uses the blkg->stat_bytes and
->stat_ios from blk-cgroup core to populate four stat knobs.
blk-cgroup core is moving away from blkg_rwstat to improve scalability
and won't be able to support this usage.
It isn't like the sharing gains all that much. Let's break them out
to dedicated rwstat counters which are updated when on cgroup1.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When used on cgroup1, bfq uses the blkg->stat_bytes and ->stat_ios
from blk-cgroup core to populate six stat knobs. blk-cgroup core is
moving away from blkg_rwstat to improve scalability and won't be able
to support this usage.
It isn't like the sharing gains all that much. Let's break it out to
dedicated rwstat counters which are updated when on cgroup1. This
makes use of bfqg_*rwstat*() helpers outside of
CONFIG_BFQ_CGROUP_DEBUG. Move them out.
v2: Compile fix when !CONFIG_BFQ_CGROUP_DEBUG.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Collect them right under #ifdef CONFIG_BFQ_CGROUP_DEBUG. The next
patch will use them from !DEBUG path and this makes it easy to move
them out of the ifdef block.
This is pure code reorganization.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull on for-linus to resolve what otherwise would have been a conflict
with the cgroups rstat patchset from Tejun.
* for-linus: (942 commits)
blkcg: make blkcg_print_stat() print stats only for online blkgs
nvme: change nvme_passthru_cmd64 to explicitly mark rsvd
nvme-multipath: fix crash in nvme_mpath_clear_ctrl_paths
nvme-rdma: fix a segmentation fault during module unload
iocost: don't nest spin_lock_irq in ioc_weight_write()
io_uring: ensure we clear io_kiocb->result before each issue
um-ubd: Entrust re-queue to the upper layers
nvme-multipath: remove unused groups_only mode in ana log
nvme-multipath: fix possible io hang after ctrl reconnect
io_uring: don't touch ctx in setup after ring fd install
io_uring: Fix leaked shadow_req
Linux 5.4-rc5
riscv: cleanup do_trap_break
nbd: verify socket is supported during setup
ata: libahci_platform: Fix regulator_get_optional() misuse
nbd: handle racing with error'ed out commands
nbd: protect cmd->status with cmd->lock
io_uring: fix bad inflight accounting for SETUP_IOPOLL|SETUP_SQTHREAD
io_uring: used cached copies of sq->dropped and cq->overflow
ARM: dts: stm32: relax qspi pins slew-rate for stm32mp157
...
Introduce three new ioctl commands BLKOPENZONE, BLKCLOSEZONE and
BLKFINISHZONE to allow applications to control the condition of zones
on a zoned block device through the execution of the REQ_OP_ZONE_OPEN,
REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH operations.
Contains contributions from Matias Bjorling, Hans Holmberg,
Dmitry Fomichev, Keith Busch, Damien Le Moal and Christoph Hellwig.
Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com>
Signed-off-by: Matias Bjorling <matias.bjorling@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Zoned block devices (ZBC and ZAC devices) allow an explicit control
over the condition (state) of zones. The operations allowed are:
* Open a zone: Transition to open condition to indicate that a zone will
actively be written
* Close a zone: Transition to closed condition to release the drive
resources used for writing to a zone
* Finish a zone: Transition an open or closed zone to the full
condition to prevent write operations
To enable this control for in-kernel zoned block device users, define
the new request operations REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE
and REQ_OP_ZONE_FINISH as well as the generic function
blkdev_zone_mgmt() for submitting these operations on a range of zones.
This results in blkdev_reset_zones() removal and replacement with this
new zone magement function. Users of blkdev_reset_zones() (f2fs and
dm-zoned) are updated accordingly.
Contains contributions from Matias Bjorling, Hans Holmberg,
Dmitry Fomichev, Keith Busch, Damien Le Moal and Christoph Hellwig.
Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com>
Signed-off-by: Matias Bjorling <matias.bjorling@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is no need for the function __blkdev_reset_all_zones() as
REQ_OP_ZONE_RESET_ALL can be handled directly in blkdev_reset_zones()
bio loop with an early break from the loop. This patch removes this
function and modifies blkdev_reset_zones(), simplifying the code.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
REQ_OP_ZONE_RESET operations cannot be merged as these bios and requests
do not have a size and are never sequential due to the zone start sector
position required for their execution. As a result, there is no point in
using a plug around blkdev_reset_zones() bio issuing loop. This patch
removes this unnecessary plugging.
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blkcg_print_stat() iterates blkgs under RCU and doesn't test whether
the blkg is online. This can call into pd_stat_fn() on a pd which is
still being initialized leading to an oops.
The heaviest operation - recursively summing up rwstat counters - is
already done while holding the queue_lock. Expand queue_lock to cover
the other operations and skip the blkg if it isn't online yet. The
online state is protected by both blkcg and queue locks, so this
guarantees that only online blkgs are processed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Roman Gushchin <guro@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Fixes: 903d23f0a3 ("blk-cgroup: allow controllers to output their own stats")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
With transition to blk-mq, the elevator= kernel argument was removed as
it makes less and less sense with the current variety of devices. Since
this may surprise some users and there are advices on the Internet that
still suggest to use it, let's at least warn if the parameter is used.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
__blk_queue_split() adds significant overhead for small I/O operations.
Add a shortcut to avoid it for cases where we know we never need to
split.
Based on a patch from Ming Lei.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
8962842ca5 ("blk-mq: avoid sysfs buffer overflow with too many CPU cores")
avoids sysfs buffer overflow, and reserves one character for line break.
However, the last snprintf() doesn't get correct 'size' parameter passed
in, so fixed it.
Fixes: 8962842ca5 ("blk-mq: avoid sysfs buffer overflow with too many CPU cores")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch introduces Opal Datastore UID.
The generic read/write table ioctl can use this UID
to access the Opal Datastore.
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Revanth Rajashekar <revanth.rajashekar@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This feature gives the user RW access to any opal table with admin1
authority. The flags described in the new structure determines if the user
wants to read/write the data. Flags are checked for valid values in
order to allow future features to be added to the ioctl.
The user can provide the desired table's UID. Also, the ioctl provides a
size and offset field and internally will loop data accesses to return
the full data block. Read overrun is prevented by the initiator's
sec_send_recv() backend. The ioctl provides a private field with the
intention to accommodate any future expansions to the ioctl.
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Revanth Rajashekar <revanth.rajashekar@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch refactors the existing "write_shadowmbr" func and
creates a new generalized function "generic_table_write_data",
to write data to any opal table. Also, a few cleanups are included
in this patch.
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Revanth Rajashekar <revanth.rajashekar@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
It is reported that sysfs buffer overflow can be triggered if the system
has too many CPU cores(>841 on 4K PAGE_SIZE) when showing CPUs of
hctx via /sys/block/$DEV/mq/$N/cpu_list.
Use snprintf to avoid the potential buffer overflow.
This version doesn't change the attribute format, and simply stops
showing CPU numbers if the buffer is going to overflow.
Cc: stable@vger.kernel.org
Fixes: 676141e48af7("blk-mq: don't dump CPU -> hw queue map on driver load")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since commit 97889f9ac2 ("blk-mq: remove synchronize_rcu() from
blk_mq_del_queue_tag_set()"), the return value of blk_mq_run_hw_queue()
is never checked, so make it return void, which very marginally simplifies
the code.
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This code causes a static analysis warning:
block/blk-iocost.c:2113 ioc_weight_write() error: double lock 'irq'
We disable IRQs in blkg_conf_prep() and re-enable them in
blkg_conf_finish(). IRQ disable/enable should not be nested because
that means the IRQs will be enabled at the first unlock instead of the
second one.
Fixes: 7caa47151a ("blkcg: implement blk-iocost")
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The only usage of the label "done" is when (rq->tag != -1) at the
beginning of the function. Rather than jumping to label, we can just
remove this label and execute the code at the "if". Besides that, the
code that would be executed after the label "done" is the return of the
logical expression (rq->tag != -1) but since we are already inside the
if, we now that this is true. Remove the label and replace the goto with
the proper result of the label.
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Instead of allocating an array of size nr_cpu_ids for set->tags, allocate
an array of size set->nr_hw_queues. This patch improves behavior that was
introduced by commit 868f2f0b72 ("blk-mq: dynamic h/w context count").
Reallocating tag sets from inside __blk_mq_update_nr_hw_queues() is safe
because:
- All request queues that share the tag sets are frozen before the tag sets
are reallocated.
- blk_mq_queue_tag_busy_iter() holds q->q_usage_counter while active and
hence is serialized against __blk_mq_update_nr_hw_queues().
Cc: Keith Busch <keith.busch@intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Instead of always allocating at least nr_cpu_ids hardware queues per request
queue, reallocate q->queue_hw_ctx if it has to grow. This patch improves
behavior that was introduced by commit 868f2f0b72 ("blk-mq: dynamic h/w
context count").
Cc: Keith Busch <keith.busch@intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since the blk_mq_{,un}freeze_queue() calls in __blk_mq_update_nr_hw_queues()
already serialize __blk_mq_update_nr_hw_queues() against
blk_mq_queue_tag_busy_iter(), the synchronize_rcu() call in
__blk_mq_update_nr_hw_queues() is not necessary. Hence remove it.
Note: the synchronize_rcu() call in __blk_mq_update_nr_hw_queues() was
introduced by commit f5bbbbe4d6 ("blk-mq: sync the update nr_hw_queues with
blk_mq_queue_tag_busy_iter"). Commit 530ca2c9bd ("blk-mq: Allow blocking
queue tag iter callbacks") removed the rcu_read_{,un}lock() calls that
correspond to the synchronize_rcu() call in __blk_mq_update_nr_hw_queues().
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
rq_qos_del() incorrectly assigns the node being deleted to the head if
it was the first on the list in the !prev path. Fix it by iterating
with ** instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Fixes: a79050434b ("blk-rq-qos: refactor out common elements of blk-wbt")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blkcg_activate_policy() has the following bugs.
* cf09a8ee19 ("blkcg: pass @q and @blkcg into
blkcg_pol_alloc_pd_fn()") added @blkcg to ->pd_alloc_fn(); however,
blkcg_activate_policy() ends up using pd's allocated for the root
blkcg for all preallocations, so ->pd_init_fn() for non-root blkcgs
can be passed in pd's which are allocated for the root blkcg.
For blk-iocost, this means that ->pd_init_fn() can write beyond the
end of the allocated object as it determines the length of the flex
array at the end based on the blkcg's nesting level.
* Each pd is initialized as they get allocated. If alloc fails, the
policy will get freed with pd's initialized on it.
* After the above partial failure, the partial pds are not freed.
This patch fixes all the above issues by
* Restructuring blkcg_activate_policy() so that alloc and init passes
are separate. Init takes place only after all allocs succeeded and
on failure all allocated pds are freed.
* Unifying and fixing the cleanup of the remaining pd_prealloc.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: cf09a8ee19 ("blkcg: pass @q and @blkcg into blkcg_pol_alloc_pd_fn()")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A BIO based request queue does not have a tag_set, which prevent testing
for the flag BLK_MQ_F_NO_SCHED indicating that the queue does not
require an elevator. This leads to an incorrect initialization of a
default elevator in some cases such as BIO based null_blk
(queue_mode == BIO) with zoned mode enabled as the default elevator in
this case is mq-deadline instead of "none".
Fix this by testing for a NULL queue mq_ops field which indicates that
the queue is BIO based and should not have an elevator.
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Presently, passthrough requests are not accounted for because
blk_do_io_stat() expressly rejects them. Based on some digging
in the history, this doesn't seem like a concious decision but
one that evolved from the change from blk_fs_request() to
blk_rq_is_passthrough().
To support this, call blk_account_io_start() in blk_execute_rq_nowait()
and remove the passthrough check in blk_do_io_stat().
Link: https://lore.kernel.org/linux-block/20191010100526.GA27209@lst.de/
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_stat_add() calls {get,put}_cpu_ptr() in a loop, which entails
overhead of disabling/enabling preemption. The loop is under RCU
(i.e.short) anyway, so do get_cpu() in advance.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Store inflight counters immediately in struct mq_inflight.
That's type-safer and removes extra indirection.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reuse a more generic callback in both blk_mq_in_flight() and
blk_mq_in_flight_rw().
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_mq_request_completed() and blk_mq_request_started() are
short, inline it.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since blk_cleanup_queue() is called after blk_unregister_queue() and
since that last function removes all sysfs attributes, serializing
any code in blk_cleanup_queue() against sysfs callback methods nor against
I/O scheduler changes is necessary. Hence remove the syfs_lock locking
calls from the start of blk_cleanup_queue().
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Block drivers must call del_gendisk() before blk_cleanup_queue().
del_gendisk() calls kobject_del() and kobject_del() waits until any
ongoing sysfs callback functions have finished. In other words, the
sysfs callback functions won't be called for a queue in the dying
state. Hence remove the "dying" checks from the sysfs callback
functions.
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 897bb0c7f1 ("blk-mq: Use proper cpumask iterator"; v4.6)
removed the last use of request_queue.nr_queues from outside
blk_mq_init_allocate_queue(). Remove this member variable to make
struct request_queue smaller. This patch does not change any
functionality.
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Fix the following kernel-doc warnings:
block/t10-pi.c:242: warning: Function parameter or member 'rq' not described in 't10_pi_type3_prepare'
block/t10-pi.c:249: warning: Function parameter or member 'rq' not described in 't10_pi_type3_complete'
block/t10-pi.c:249: warning: Function parameter or member 'nr_bytes' not described in 't10_pi_type3_complete'
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Fixes: 54d4e6ab91 ("block: centralize PI remapping logic to the block layer")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
scale_up wakes up waiters after scaling up. But after scaling max, it
should not wake up more waiters as waiters will not have anything to
do. This patch fixes this by making scale_up (and also scale_down)
return when threshold is reached.
This bug causes increased fdatasync latency when fdatasync and dd
conv=sync are performed in parallel on 4.19 compared to 4.14. This
bug was introduced during refactoring of blk-wbt code.
Fixes: a79050434b ("blk-rq-qos: refactor out common elements of blk-wbt")
Cc: stable@vger.kernel.org
Cc: Josef Bacik <jbacik@fb.com>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
sparse warns about incorrect type when using __be64 data.
It is not being converted to CPU-endian but it should be.
Fixes these sparse warnings:
../block/sed-opal.c:375:20: warning: incorrect type in assignment (different base types)
../block/sed-opal.c:375:20: expected unsigned long long [usertype] align
../block/sed-opal.c:375:20: got restricted __be64 const [usertype] alignment_granularity
../block/sed-opal.c:376:25: warning: incorrect type in assignment (different base types)
../block/sed-opal.c:376:25: expected unsigned long long [usertype] lowest_lba
../block/sed-opal.c:376:25: got restricted __be64 const [usertype] lowest_aligned_lba
Fixes: 455a7b238c ("block: Add Sed-opal library")
Cc: Scott Bauer <scott.bauer@intel.com>
Cc: Rafael Antognolli <rafael.antognolli@intel.com>
Cc: linux-block@vger.kernel.org
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Some HDD drive may expose multiple hardware queues, such as MegraRaid.
Let's apply the normal plugging for such devices because sequential IO
may benefit a lot from plug merging.
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If a device is using multiple queues, the IO scheduler may be bypassed.
This may hurt performance for some slow MQ devices, and it also breaks
zoned devices which depend on mq-deadline for respecting the write order
in one zone.
Don't bypass io scheduler if we have one setup.
This patch can double sequential write performance basically on MQ
scsi_debug when mq-deadline is applied.
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We got a null pointer deference BUG_ON in blk_mq_rq_timed_out()
as following:
[ 108.825472] BUG: kernel NULL pointer dereference, address: 0000000000000040
[ 108.827059] PGD 0 P4D 0
[ 108.827313] Oops: 0000 [#1] SMP PTI
[ 108.827657] CPU: 6 PID: 198 Comm: kworker/6:1H Not tainted 5.3.0-rc8+ #431
[ 108.829503] Workqueue: kblockd blk_mq_timeout_work
[ 108.829913] RIP: 0010:blk_mq_check_expired+0x258/0x330
[ 108.838191] Call Trace:
[ 108.838406] bt_iter+0x74/0x80
[ 108.838665] blk_mq_queue_tag_busy_iter+0x204/0x450
[ 108.839074] ? __switch_to_asm+0x34/0x70
[ 108.839405] ? blk_mq_stop_hw_queue+0x40/0x40
[ 108.839823] ? blk_mq_stop_hw_queue+0x40/0x40
[ 108.840273] ? syscall_return_via_sysret+0xf/0x7f
[ 108.840732] blk_mq_timeout_work+0x74/0x200
[ 108.841151] process_one_work+0x297/0x680
[ 108.841550] worker_thread+0x29c/0x6f0
[ 108.841926] ? rescuer_thread+0x580/0x580
[ 108.842344] kthread+0x16a/0x1a0
[ 108.842666] ? kthread_flush_work+0x170/0x170
[ 108.843100] ret_from_fork+0x35/0x40
The bug is caused by the race between timeout handle and completion for
flush request.
When timeout handle function blk_mq_rq_timed_out() try to read
'req->q->mq_ops', the 'req' have completed and reinitiated by next
flush request, which would call blk_rq_init() to clear 'req' as 0.
After commit 12f5b93145 ("blk-mq: Remove generation seqeunce"),
normal requests lifetime are protected by refcount. Until 'rq->ref'
drop to zero, the request can really be free. Thus, these requests
cannot been reused before timeout handle finish.
However, flush request has defined .end_io and rq->end_io() is still
called even if 'rq->ref' doesn't drop to zero. After that, the 'flush_rq'
can be reused by the next flush request handle, resulting in null
pointer deference BUG ON.
We fix this problem by covering flush request with 'rq->ref'.
If the refcount is not zero, flush_end_io() return and wait the
last holder recall it. To record the request status, we add a new
entry 'rq_status', which will be used in flush_end_io().
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: stable@vger.kernel.org # v4.18+
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
-------
v2:
- move rq_status from struct request to struct blk_flush_queue
v3:
- remove unnecessary '{}' pair.
v4:
- let spinlock to protect 'fq->rq_status'
v5:
- move rq_status after flush_running_idx member of struct blk_flush_queue
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We have updated limits after calling wbt_set_min_lat(). No need to
update again.
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The default hard disk param sets latency targets at 50ms. As the
default target percentiles are zero, these don't directly regulate
vrate; however, they're still used to calculate the period length -
100ms in this case.
This is excessively low. A SATA drive with QD32 saturated with random
IOs can easily reach avg completion latency of several hundred msecs.
A period duration which is substantially lower than avg completion
latency can lead to wildly fluctuating vrate.
Let's bump up the default latency targets to 250ms so that the period
duration is sufficiently long.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Some IOs may span multiple periods. As latencies are collected on
completion, the inbetween periods won't register them and may
incorrectly decide to increase vrate. nr_lagging tracks these IOs to
avoid those situations. Currently, whenever there are IOs which are
spanning from the previous period, busy_level is reset to 0 if
negative thus suppressing vrate increase.
This has the following two problems.
* When latency target percentiles aren't set, vrate adjustment should
only be governed by queue depth depletion; however, the current code
keeps nr_lagging active which pulls in latency results and can keep
down vrate unexpectedly.
* When lagging condition is detected, it resets the entire negative
busy_level. This turned out to be way too aggressive on some
devices which sometimes experience extended latencies on a small
subset of commands. In addition, a lagging IO will be accounted as
latency target miss on completion anyway and resetting busy_level
amplifies its impact unnecessarily.
This patch fixes the above two problems by disabling nr_lagging
counting when latency target percentiles aren't set and blocking vrate
increases when there are lagging IOs while leaving busy_level as-is.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
vrate_adj tracepoint traces vrate changes; however, it does so only
when busy_level is non-zero. busy_level turning to zero can sometimes
be as interesting an event. This patch also enables vrate_adj
tracepoint on other vrate related events - busy_level changes and
non-zero nr_lagging.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
