Граф коммитов

834 Коммитов

Автор SHA1 Сообщение Дата
Linus Torvalds d769139081 block-5.10-2020-10-24
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Merge tag 'block-5.10-2020-10-24' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph
     - rdma error handling fixes (Chao Leng)
     - fc error handling and reconnect fixes (James Smart)
     - fix the qid displace when tracing ioctl command (Keith Busch)
     - don't use BLK_MQ_REQ_NOWAIT for passthru (Chaitanya Kulkarni)
     - fix MTDT for passthru (Logan Gunthorpe)
     - blacklist Write Same on more devices (Kai-Heng Feng)
     - fix an uninitialized work struct (zhenwei pi)"

 - lightnvm out-of-bounds fix (Colin)

 - SG allocation leak fix (Doug)

 - rnbd fixes (Gioh, Guoqing, Jack)

 - zone error translation fixes (Keith)

 - kerneldoc markup fix (Mauro)

 - zram lockdep fix (Peter)

 - Kill unused io_context members (Yufen)

 - NUMA memory allocation cleanup (Xianting)

 - NBD config wakeup fix (Xiubo)

* tag 'block-5.10-2020-10-24' of git://git.kernel.dk/linux-block: (27 commits)
  block: blk-mq: fix a kernel-doc markup
  nvme-fc: shorten reconnect delay if possible for FC
  nvme-fc: wait for queues to freeze before calling update_hr_hw_queues
  nvme-fc: fix error loop in create_hw_io_queues
  nvme-fc: fix io timeout to abort I/O
  null_blk: use zone status for max active/open
  nvmet: don't use BLK_MQ_REQ_NOWAIT for passthru
  nvmet: cleanup nvmet_passthru_map_sg()
  nvmet: limit passthru MTDS by BIO_MAX_PAGES
  nvmet: fix uninitialized work for zero kato
  nvme-pci: disable Write Zeroes on Sandisk Skyhawk
  nvme: use queuedata for nvme_req_qid
  nvme-rdma: fix crash due to incorrect cqe
  nvme-rdma: fix crash when connect rejected
  block: remove unused members for io_context
  blk-mq: remove the calling of local_memory_node()
  zram: Fix __zram_bvec_{read,write}() locking order
  skd_main: remove unused including <linux/version.h>
  sgl_alloc_order: fix memory leak
  lightnvm: fix out-of-bounds write to array devices->info[]
  ...
2020-10-24 12:46:42 -07:00
Mauro Carvalho Chehab 24f7bb8863 block: blk-mq: fix a kernel-doc markup
Fix a typo:
	blk_mq_run_hw_queue -> blk_mq_run_hw_queues

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23 12:20:17 -06:00
Xianting Tian 576e85c5e9 blk-mq: remove the calling of local_memory_node()
We don't need to check whether the node is memoryless numa node before
calling allocator interface. SLUB(and SLAB,SLOB) relies on the page
allocator to pick a node. Page allocator should deal with memoryless
nodes just fine. It has zonelists constructed for each possible nodes.
And it will automatically fall back into a node which is closest to the
requested node. As long as __GFP_THISNODE is not enforced of course.

The code comments of kmem_cache_alloc_node() of SLAB also showed this:
 * Fallback to other node is possible if __GFP_THISNODE is not set.

blk-mq code doesn't set __GFP_THISNODE, so we can remove the calling
of local_memory_node().

Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-20 07:08:17 -06:00
Linus Torvalds 4815519ed0 - Improve DM core's bio splitting to use blk_max_size_offset(). Also
fix bio splitting for bios that were deferred to the worker thread
   due to a DM device being suspended.
 
 - Remove DM core's special handling of NVMe devices now that block
   core has internalized efficiencies drivers previously needed to
   be concerned about (via now removed direct_make_request).
 
 - Fix request-based DM to not bounce through indirect dm_submit_bio;
   instead have block core make direct call to blk_mq_submit_bio().
 
 - Various DM core cleanups to simplify and improve code.
 
 - Update DM cryot to not use drivers that set
   CRYPTO_ALG_ALLOCATES_MEMORY.
 
 - Fix DM raid's raid1 and raid10 discard limits for the purposes of
   linux-stable. But then remove DM raid's discard limits settings now
   that MD raid can efficiently handle large discards.
 
 - A couple small cleanups across various targets.
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Merge tag 'for-5.10/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - Improve DM core's bio splitting to use blk_max_size_offset(). Also
   fix bio splitting for bios that were deferred to the worker thread
   due to a DM device being suspended.

 - Remove DM core's special handling of NVMe devices now that block core
   has internalized efficiencies drivers previously needed to be
   concerned about (via now removed direct_make_request).

 - Fix request-based DM to not bounce through indirect dm_submit_bio;
   instead have block core make direct call to blk_mq_submit_bio().

 - Various DM core cleanups to simplify and improve code.

 - Update DM cryot to not use drivers that set
   CRYPTO_ALG_ALLOCATES_MEMORY.

 - Fix DM raid's raid1 and raid10 discard limits for the purposes of
   linux-stable. But then remove DM raid's discard limits settings now
   that MD raid can efficiently handle large discards.

 - A couple small cleanups across various targets.

* tag 'for-5.10/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: fix request-based DM to not bounce through indirect dm_submit_bio
  dm: remove special-casing of bio-based immutable singleton target on NVMe
  dm: export dm_copy_name_and_uuid
  dm: fix comment in __dm_suspend()
  dm: fold dm_process_bio() into dm_submit_bio()
  dm: fix missing imposition of queue_limits from dm_wq_work() thread
  dm snap persistent: simplify area_io()
  dm thin metadata: Remove unused local variable when create thin and snap
  dm raid: remove unnecessary discard limits for raid10
  dm raid: fix discard limits for raid1 and raid10
  dm crypt: don't use drivers that have CRYPTO_ALG_ALLOCATES_MEMORY
  dm: use dm_table_get_device_name() where appropriate in targets
  dm table: make 'struct dm_table' definition accessible to all of DM core
  dm: eliminate need for start_io_acct() forward declaration
  dm: simplify __process_abnormal_io()
  dm: push use of on-stack flush_bio down to __send_empty_flush()
  dm: optimize max_io_len() by inlining max_io_len_target_boundary()
  dm: push md->immutable_target optimization down to __process_bio()
  dm: change max_io_len() to use blk_max_size_offset()
  dm table: stack 'chunk_sectors' limit to account for target-specific splitting
2020-10-14 15:05:38 -07:00
Linus Torvalds 3ad11d7ac8 block-5.10-2020-10-12
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Merge tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - Series of merge handling cleanups (Baolin, Christoph)

 - Series of blk-throttle fixes and cleanups (Baolin)

 - Series cleaning up BDI, seperating the block device from the
   backing_dev_info (Christoph)

 - Removal of bdget() as a generic API (Christoph)

 - Removal of blkdev_get() as a generic API (Christoph)

 - Cleanup of is-partition checks (Christoph)

 - Series reworking disk revalidation (Christoph)

 - Series cleaning up bio flags (Christoph)

 - bio crypt fixes (Eric)

 - IO stats inflight tweak (Gabriel)

 - blk-mq tags fixes (Hannes)

 - Buffer invalidation fixes (Jan)

 - Allow soft limits for zone append (Johannes)

 - Shared tag set improvements (John, Kashyap)

 - Allow IOPRIO_CLASS_RT for CAP_SYS_NICE (Khazhismel)

 - DM no-wait support (Mike, Konstantin)

 - Request allocation improvements (Ming)

 - Allow md/dm/bcache to use IO stat helpers (Song)

 - Series improving blk-iocost (Tejun)

 - Various cleanups (Geert, Damien, Danny, Julia, Tetsuo, Tian, Wang,
   Xianting, Yang, Yufen, yangerkun)

* tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block: (191 commits)
  block: fix uapi blkzoned.h comments
  blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue
  blk-mq: get rid of the dead flush handle code path
  block: get rid of unnecessary local variable
  block: fix comment and add lockdep assert
  blk-mq: use helper function to test hw stopped
  block: use helper function to test queue register
  block: remove redundant mq check
  block: invoke blk_mq_exit_sched no matter whether have .exit_sched
  percpu_ref: don't refer to ref->data if it isn't allocated
  block: ratelimit handle_bad_sector() message
  blk-throttle: Re-use the throtl_set_slice_end()
  blk-throttle: Open code __throtl_de/enqueue_tg()
  blk-throttle: Move service tree validation out of the throtl_rb_first()
  blk-throttle: Move the list operation after list validation
  blk-throttle: Fix IO hang for a corner case
  blk-throttle: Avoid tracking latency if low limit is invalid
  blk-throttle: Avoid getting the current time if tg->last_finish_time is 0
  blk-throttle: Remove a meaningless parameter for throtl_downgrade_state()
  block: Remove redundant 'return' statement
  ...
2020-10-13 12:12:44 -07:00
Yufen Yu 0841031ab9 blk-mq: use helper function to test hw stopped
We have introduced helper function blk_mq_hctx_stopped() to test
BLK_MQ_S_STOPPED.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-09 12:34:06 -06:00
Mike Snitzer 681cc5e866 dm: fix request-based DM to not bounce through indirect dm_submit_bio
It is unnecessary to force request-based DM to call into bio-based
dm_submit_bio (via indirect disk->fops->submit_bio) only to have it then
call blk_mq_submit_bio().

Fix this by establishing a request-based DM block_device_operations
(dm_rq_blk_dops, which doesn't have .submit_bio) and update
dm_setup_md_queue() to set md->disk->fops to it for
DM_TYPE_REQUEST_BASED.

Remove DM_TYPE_REQUEST_BASED conditional in dm_submit_bio and unexport
blk_mq_submit_bio.

Fixes: c62b37d96b ("block: move ->make_request_fn to struct block_device_operations")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-10-07 18:08:51 -04:00
Gabriel Krisman Bertazi a926c7afff block: Consider only dispatched requests for inflight statistic
According to Documentation/block/stat.rst, inflight should not include
I/O requests that are in the queue but not yet dispatched to the device,
but blk-mq identifies as inflight any request that has a tag allocated,
which, for queues without elevator, happens at request allocation time
and before it is queued in the ctx (default case in blk_mq_submit_bio).

In addition, current behavior is different for queues with elevator from
queues without it, since for the former the driver tag is allocated at
dispatch time.  A more precise approach would be to only consider
requests with state MQ_RQ_IN_FLIGHT.

This effectively reverts commit 6131837b1d ("blk-mq: count allocated
but not started requests in iostats inflight") to consolidate blk-mq
behavior with itself (elevator case) and with original documentation,
but it differs from the behavior used by the legacy path.

This version differs from v1 by using blk_mq_rq_state to access the
state attribute.  Avoid using blk_mq_request_started, which was
suggested, since we don't want to include MQ_RQ_COMPLETE.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Cc: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-06 14:36:35 -06:00
Eric Biggers 93f221ae08 block: make blk_crypto_rq_bio_prep() able to fail
blk_crypto_rq_bio_prep() assumes its gfp_mask argument always includes
__GFP_DIRECT_RECLAIM, so that the mempool_alloc() will always succeed.

However, blk_crypto_rq_bio_prep() might be called with GFP_ATOMIC via
setup_clone() in drivers/md/dm-rq.c.

This case isn't currently reachable with a bio that actually has an
encryption context.  However, it's fragile to rely on this.  Just make
blk_crypto_rq_bio_prep() able to fail.

Suggested-by: Satya Tangirala <satyat@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Satya Tangirala <satyat@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-05 10:47:43 -06:00
yangerkun 632bfb6323 blk-mq: call commit_rqs while list empty but error happen
Blk-mq should call commit_rqs once 'bd.last != true' and no more
request will come(so virtscsi can kick the virtqueue, e.g.). We already
do that in 'blk_mq_dispatch_rq_list/blk_mq_try_issue_list_directly' while
list not empty and 'queued > 0'. However, we can seen the same scene
once the last request in list call queue_rq and return error like
BLK_STS_IOERR which will not requeue the request, and lead that list
empty but need call commit_rqs too(Or the request for virtscsi will stay
timeout until other request kick virtqueue).

We found this problem by do fsstress test with offline/online virtscsi
device repeat quickly.

Fixes: d666ba98f8 ("blk-mq: add mq_ops->commit_rqs()")
Reported-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-29 08:10:17 -06:00
Xianting Tian 8229cca8c3 blk-mq: add cond_resched() in __blk_mq_alloc_rq_maps()
We found blk_mq_alloc_rq_maps() takes more time in kernel space when
testing nvme device hot-plugging. The test and anlysis as below.

Debug code,
1, blk_mq_alloc_rq_maps():
        u64 start, end;
        depth = set->queue_depth;
        start = ktime_get_ns();
        pr_err("[%d:%s switch:%ld,%ld] queue depth %d, nr_hw_queues %d\n",
                        current->pid, current->comm, current->nvcsw, current->nivcsw,
                        set->queue_depth, set->nr_hw_queues);
        do {
                err = __blk_mq_alloc_rq_maps(set);
                if (!err)
                        break;

                set->queue_depth >>= 1;
                if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) {
                        err = -ENOMEM;
                        break;
                }
        } while (set->queue_depth);
        end = ktime_get_ns();
        pr_err("[%d:%s switch:%ld,%ld] all hw queues init cost time %lld ns\n",
                        current->pid, current->comm,
                        current->nvcsw, current->nivcsw, end - start);

2, __blk_mq_alloc_rq_maps():
        u64 start, end;
        for (i = 0; i < set->nr_hw_queues; i++) {
                start = ktime_get_ns();
                if (!__blk_mq_alloc_rq_map(set, i))
                        goto out_unwind;
                end = ktime_get_ns();
                pr_err("hw queue %d init cost time %lld ns\n", i, end - start);
        }

Test nvme hot-plugging with above debug code, we found it totally cost more
than 3ms in kernel space without being scheduled out when alloc rqs for all
16 hw queues with depth 1023, each hw queue cost about 140-250us. The cost
time will be increased with hw queue number and queue depth increasing. And
in an extreme case, if __blk_mq_alloc_rq_maps() returns -ENOMEM, it will try
"queue_depth >>= 1", more time will be consumed.
	[  428.428771] nvme nvme0: pci function 10000:01:00.0
	[  428.428798] nvme 10000:01:00.0: enabling device (0000 -> 0002)
	[  428.428806] pcieport 10000:00:00.0: can't derive routing for PCI INT A
	[  428.428809] nvme 10000:01:00.0: PCI INT A: no GSI
	[  432.593374] [4688:kworker/u33:8 switch:663,2] queue depth 30, nr_hw_queues 1
	[  432.593404] hw queue 0 init cost time 22883 ns
	[  432.593408] [4688:kworker/u33:8 switch:663,2] all hw queues init cost time 35960 ns
	[  432.595953] nvme nvme0: 16/0/0 default/read/poll queues
	[  432.595958] [4688:kworker/u33:8 switch:700,2] queue depth 1023, nr_hw_queues 16
	[  432.596203] hw queue 0 init cost time 242630 ns
	[  432.596441] hw queue 1 init cost time 235913 ns
	[  432.596659] hw queue 2 init cost time 216461 ns
	[  432.596877] hw queue 3 init cost time 215851 ns
	[  432.597107] hw queue 4 init cost time 228406 ns
	[  432.597336] hw queue 5 init cost time 227298 ns
	[  432.597564] hw queue 6 init cost time 224633 ns
	[  432.597785] hw queue 7 init cost time 219954 ns
	[  432.597937] hw queue 8 init cost time 150930 ns
	[  432.598082] hw queue 9 init cost time 143496 ns
	[  432.598231] hw queue 10 init cost time 147261 ns
	[  432.598397] hw queue 11 init cost time 164522 ns
	[  432.598542] hw queue 12 init cost time 143401 ns
	[  432.598692] hw queue 13 init cost time 148934 ns
	[  432.598841] hw queue 14 init cost time 147194 ns
	[  432.598991] hw queue 15 init cost time 148942 ns
	[  432.598993] [4688:kworker/u33:8 switch:700,2] all hw queues init cost time 3035099 ns
	[  432.602611]  nvme0n1: p1

So use this patch to trigger schedule between each hw queue init, to avoid
other threads getting stuck. It is not in atomic context when executing
__blk_mq_alloc_rq_maps(), so it is safe to call cond_resched().

Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-28 09:01:51 -06:00
Ming Lei 285008501c blk-mq: always allow reserved allocation in hctx_may_queue
NVMe shares tagset between fabric queue and admin queue or between
connect_q and NS queue, so hctx_may_queue() can be called to allocate
request for these queues.

Tags can be reserved in these tagset. Before error recovery, there is
often lots of in-flight requests which can't be completed, and new
reserved request may be needed in error recovery path. However,
hctx_may_queue() can always return false because there is too many
in-flight requests which can't be completed during error handling.
Finally, nothing can proceed.

Fix this issue by always allowing reserved tag allocation in
hctx_may_queue(). This is reasonable because reserved tags are supposed
to always be available.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: David Milburn <dmilburn@redhat.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-11 05:26:19 -06:00
Kashyap Desai b445547ec1 blk-mq, elevator: Count requests per hctx to improve performance
High CPU utilization on "native_queued_spin_lock_slowpath" due to lock
contention is possible for mq-deadline and bfq IO schedulers
when nr_hw_queues is more than one.

It is because kblockd work queue can submit IO from all online CPUs
(through blk_mq_run_hw_queues()) even though only one hctx has pending
commands.

The elevator callback .has_work for mq-deadline and bfq scheduler considers
pending work if there are any IOs on request queue but it does not account
hctx context.

Add a per-hctx 'elevator_queued' count to the hctx to avoid triggering
the elevator even though there are no requests queued.

[jpg: Relocated atomic_dec() in dd_dispatch_request(), update commit message per Kashyap]

Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-03 15:20:47 -06:00
John Garry f1b49fdc1c blk-mq: Record active_queues_shared_sbitmap per tag_set for when using shared sbitmap
For when using a shared sbitmap, no longer should the number of active
request queues per hctx be relied on for when judging how to share the tag
bitmap.

Instead maintain the number of active request queues per tag_set, and make
the judgement based on that.

Originally-from: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Don Brace<don.brace@microsemi.com> #SCSI resv cmds patches used
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-03 15:20:47 -06:00
John Garry bccf5e26d9 blk-mq: Record nr_active_requests per queue for when using shared sbitmap
The per-hctx nr_active value can no longer be used to fairly assign a share
of tag depth per request queue for when using a shared sbitmap, as it does
not consider that the tags are shared tags over all hctx's.

For this case, record the nr_active_requests per request_queue, and make
the judgement based on that value.

Co-developed-with: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Don Brace<don.brace@microsemi.com> #SCSI resv cmds patches used
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-03 15:20:47 -06:00
John Garry 32bc15afed blk-mq: Facilitate a shared sbitmap per tagset
Some SCSI HBAs (such as HPSA, megaraid, mpt3sas, hisi_sas_v3 ..) support
multiple reply queues with single hostwide tags.

In addition, these drivers want to use interrupt assignment in
pci_alloc_irq_vectors(PCI_IRQ_AFFINITY). However, as discussed in [0],
CPU hotplug may cause in-flight IO completion to not be serviced when an
interrupt is shutdown. That problem is solved in commit bf0beec060
("blk-mq: drain I/O when all CPUs in a hctx are offline").

However, to take advantage of that blk-mq feature, the HBA HW queuess are
required to be mapped to that of the blk-mq hctx's; to do that, the HBA HW
queues need to be exposed to the upper layer.

In making that transition, the per-SCSI command request tags are no
longer unique per Scsi host - they are just unique per hctx. As such, the
HBA LLDD would have to generate this tag internally, which has a certain
performance overhead.

However another problem is that blk-mq assumes the host may accept
(Scsi_host.can_queue * #hw queue) commands. In commit 6eb045e092 ("scsi:
 core: avoid host-wide host_busy counter for scsi_mq"), the Scsi host busy
counter was removed, which would stop the LLDD being sent more than
.can_queue commands; however, it should still be ensured that the block
layer does not issue more than .can_queue commands to the Scsi host.

To solve this problem, introduce a shared sbitmap per blk_mq_tag_set,
which may be requested at init time.

New flag BLK_MQ_F_TAG_HCTX_SHARED should be set when requesting the
tagset to indicate whether the shared sbitmap should be used.

Even when BLK_MQ_F_TAG_HCTX_SHARED is set, a full set of tags and requests
are still allocated per hctx; the reason for this is that if tags and
requests were only allocated for a single hctx - like hctx0 - it may break
block drivers which expect a request be associated with a specific hctx,
i.e. not always hctx0. This will introduce extra memory usage.

This change is based on work originally from Ming Lei in [1] and from
Bart's suggestion in [2].

[0] https://lore.kernel.org/linux-block/alpine.DEB.2.21.1904051331270.1802@nanos.tec.linutronix.de/
[1] https://lore.kernel.org/linux-block/20190531022801.10003-1-ming.lei@redhat.com/
[2] https://lore.kernel.org/linux-block/ff77beff-5fd9-9f05-12b6-826922bace1f@huawei.com/T/#m3db0a602f095cbcbff27e9c884d6b4ae826144be

Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Don Brace<don.brace@microsemi.com> #SCSI resv cmds patches used
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-03 15:20:47 -06:00
John Garry 222a5ae03c blk-mq: Use pointers for blk_mq_tags bitmap tags
Introduce pointers for the blk_mq_tags regular and reserved bitmap tags,
with the goal of later being able to use a common shared tag bitmap across
all HW contexts in a set.

Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Don Brace<don.brace@microsemi.com> #SCSI resv cmds patches used
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-03 15:20:47 -06:00
John Garry 1c0706a70a blk-mq: Pass flags for tag init/free
Pass hctx/tagset flags argument down to blk_mq_init_tags() and
blk_mq_free_tags() for selective init/free.

For now, make it include the alloc policy flag, which can be evaluated
when needed (in blk_mq_init_tags()).

Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-03 15:20:46 -06:00
Hannes Reinecke 655ac30094 blk-mq: Rename blk_mq_update_tag_set_depth()
The function does not set the depth, but rather transitions from
shared to non-shared queues and vice versa.

So rename it to blk_mq_update_tag_set_shared() to better reflect
its purpose.

[jpg: take out some unrelated changes in blk_mq_init_bitmap_tags()]

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-03 15:20:46 -06:00
Ming Lei 51db1c37ee blk-mq: Rename BLK_MQ_F_TAG_SHARED as BLK_MQ_F_TAG_QUEUE_SHARED
BLK_MQ_F_TAG_SHARED actually means that tags is shared among request
queues, all of which should belong to LUNs attached to same HBA.

So rename it to make the point explicitly.

[jpg: rebase a few times, add rnbd-clt.c change]

Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-03 15:20:46 -06:00
Ming Lei db03f88fae blk-mq: insert request not through ->queue_rq into sw/scheduler queue
c616cbee97 ("blk-mq: punt failed direct issue to dispatch list") supposed
to add request which has been through ->queue_rq() to the hw queue dispatch
list, however it adds request running out of budget or driver tag to hw queue
too. This way basically bypasses request merge, and causes too many request
dispatched to LLD, and system% is unnecessary increased.

Fixes this issue by adding request not through ->queue_rq into sw/scheduler
queue, and this way is safe because no ->queue_rq is called on this request
yet.

High %system can be observed on Azure storvsc device, and even soft lock
is observed. This patch reduces %system during heavy sequential IO,
meantime decreases soft lockup risk.

Fixes: c616cbee97 ("blk-mq: punt failed direct issue to dispatch list")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-21 17:09:22 -06:00
Ming Lei d7d8535f37 blk-mq: order adding requests to hctx->dispatch and checking SCHED_RESTART
SCHED_RESTART code path is relied to re-run queue for dispatch requests
in hctx->dispatch. Meantime the SCHED_RSTART flag is checked when adding
requests to hctx->dispatch.

memory barriers have to be used for ordering the following two pair of OPs:

1) adding requests to hctx->dispatch and checking SCHED_RESTART in
blk_mq_dispatch_rq_list()

2) clearing SCHED_RESTART and checking if there is request in hctx->dispatch
in blk_mq_sched_restart().

Without the added memory barrier, either:

1) blk_mq_sched_restart() may miss requests added to hctx->dispatch meantime
blk_mq_dispatch_rq_list() observes SCHED_RESTART, and not run queue in
dispatch side

or

2) blk_mq_dispatch_rq_list still sees SCHED_RESTART, and not run queue
in dispatch side, meantime checking if there is request in
hctx->dispatch from blk_mq_sched_restart() is missed.

IO hang in ltp/fs_fill test is reported by kernel test robot:

	https://lkml.org/lkml/2020/7/26/77

Turns out it is caused by the above out-of-order OPs. And the IO hang
can't be observed any more after applying this patch.

Fixes: bd166ef183 ("blk-mq-sched: add framework for MQ capable IO schedulers")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Jeffery <djeffery@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-17 06:57:49 -07:00
Randy Dunlap 26bfeb2662 block: blk-mq.c: fix @at_head kernel-doc warning
Fix a kernel-doc warning in block/blk-mq.c:

../block/blk-mq.c:1844: warning: Function parameter or member 'at_head' not described in 'blk_mq_request_bypass_insert'

Fixes: 01e99aeca3 ("blk-mq: insert passthrough request into hctx->dispatch directly")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: André Almeida <andrealmeid@collabora.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: linux-block@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-16 16:50:28 -07:00
Linus Torvalds 382625d0d4 for-5.9/block-20200802
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Merge tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-block

Pull core block updates from Jens Axboe:
 "Good amount of cleanups and tech debt removals in here, and as a
  result, the diffstat shows a nice net reduction in code.

   - Softirq completion cleanups (Christoph)

   - Stop using ->queuedata (Christoph)

   - Cleanup bd claiming (Christoph)

   - Use check_events, moving away from the legacy media change
     (Christoph)

   - Use inode i_blkbits consistently (Christoph)

   - Remove old unused writeback congestion bits (Christoph)

   - Cleanup/unify submission path (Christoph)

   - Use bio_uninit consistently, instead of bio_disassociate_blkg
     (Christoph)

   - sbitmap cleared bits handling (John)

   - Request merging blktrace event addition (Jan)

   - sysfs add/remove race fixes (Luis)

   - blk-mq tag fixes/optimizations (Ming)

   - Duplicate words in comments (Randy)

   - Flush deferral cleanup (Yufen)

   - IO context locking/retry fixes (John)

   - struct_size() usage (Gustavo)

   - blk-iocost fixes (Chengming)

   - blk-cgroup IO stats fixes (Boris)

   - Various little fixes"

* tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-block: (135 commits)
  block: blk-timeout: delete duplicated word
  block: blk-mq-sched: delete duplicated word
  block: blk-mq: delete duplicated word
  block: genhd: delete duplicated words
  block: elevator: delete duplicated word and fix typos
  block: bio: delete duplicated words
  block: bfq-iosched: fix duplicated word
  iocost_monitor: start from the oldest usage index
  iocost: Fix check condition of iocg abs_vdebt
  block: Remove callback typedefs for blk_mq_ops
  block: Use non _rcu version of list functions for tag_set_list
  blk-cgroup: show global disk stats in root cgroup io.stat
  blk-cgroup: make iostat functions visible to stat printing
  block: improve discard bio alignment in __blkdev_issue_discard()
  block: change REQ_OP_ZONE_RESET and REQ_OP_ZONE_RESET_ALL to be odd numbers
  block: defer flush request no matter whether we have elevator
  block: make blk_timeout_init() static
  block: remove retry loop in ioc_release_fn()
  block: remove unnecessary ioc nested locking
  block: integrate bd_start_claiming into __blkdev_get
  ...
2020-08-03 11:57:03 -07:00
Randy Dunlap 70f15a4fd9 block: blk-mq: delete duplicated word
Drop the repeated word "the".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-31 16:29:47 -06:00
Daniel Wagner 08c875cbf4 block: Use non _rcu version of list functions for tag_set_list
tag_set_list is only accessed under the tag_set_lock lock. There is
no need for using the _rcu list functions.

The _rcu list function were introduced to allow read access to the
tag_set_list protected under RCU, see 705cda97ee ("blk-mq: Make it
safe to use RCU to iterate over blk_mq_tag_set.tag_list") and
05b7941394 ("Revert "blk-mq: don't handle TAG_SHARED in restart"").
Those changes got reverted later but the cleanup commit missed a
couple of places to undo the changes.

Fixes: 97889f9ac2 ("blk-mq: remove synchronize_rcu() from blk_mq_del_queue_tag_set()"
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-28 09:37:09 -06:00
Baolin Wang 87890092ee blk-mq: remove redundant validation in __blk_mq_end_request()
We've already validated the 'q->elevator' before calling
->ops.completed_request() in blk_mq_sched_completed_request(), thus no
need to validate rq->internal_tag again. Rmove it.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-10 07:58:33 -06:00
Ming Lei 568f270065 blk-mq: centralise related handling into blk_mq_get_driver_tag
Move .nr_active update and request assignment into blk_mq_get_driver_tag(),
all are good to do during getting driver tag.

Meantime blk-flush related code is simplified and flush request needn't
to update the request table manually any more.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-08 16:06:42 -06:00
Ming Lei 7bf137298c blk-mq: streamline handling of q->mq_ops->queue_rq result
Current handling of q->mq_ops->queue_rq result is a bit ugly:

- two branches which needs to 'continue' have to check if the
dispatch local list is empty, otherwise one bad request may
be retrieved via 'rq = list_first_entry(list, struct request, queuelist);'

- the branch of 'if (unlikely(ret != BLK_STS_OK))' isn't easy
to follow, since it is actually one error branch.

Streamline this handling, so the code becomes more readable, meantime
potential kernel oops can be avoided in case that the last request in
local dispatch list is failed.

Fixes: fc17b6534e ("blk-mq: switch ->queue_rq return value to blk_status_t")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-08 16:04:39 -06:00
Ming Lei 05a4fed69f blk-mq: consider non-idle request as "inflight" in blk_mq_rq_inflight()
dm-multipath is the only user of blk_mq_queue_inflight().  When
dm-multipath calls blk_mq_queue_inflight() to check if it has
outstanding IO it can get a false negative.  The reason for this is
blk_mq_rq_inflight() doesn't consider requests that are no longer
MQ_RQ_IN_FLIGHT but that are now MQ_RQ_COMPLETE (->complete isn't
called or finished yet) as "inflight".

This causes request-based dm-multipath's dm_wait_for_completion() to
return before all outstanding dm-multipath requests have actually
completed.  This breaks DM multipath's suspend functionality because
blk-mq requests complete after DM's suspend has finished -- which
shouldn't happen.

Fix this by considering any request not in the MQ_RQ_IDLE state
(so either MQ_RQ_COMPLETE or MQ_RQ_IN_FLIGHT) as "inflight" in
blk_mq_rq_inflight().

Fixes: 3c94d83cb3 ("blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight()")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-07 09:06:25 -06:00
Jens Axboe 4e2f62e566 Revert "blk-mq: put driver tag when this request is completed"
This reverts commits the following commits:

	37f4a24c24
	723bf178f1
	36a3df5a45

The last one is the culprit, but we have to go a bit deeper to get this
to revert cleanly. There's been a report that this breaks some MMC
setups [1], and also causes an issue with swap [2]. Until this can be
figured out, revert the offending commits.

[1] https://lore.kernel.org/linux-block/57fb09b1-54ba-f3aa-f82c-d709b0e6b281@samsung.com/
[2] https://lore.kernel.org/linux-block/20200702043721.GA1087@lca.pw/

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 22:58:32 -06:00
Christoph Hellwig c62b37d96b block: move ->make_request_fn to struct block_device_operations
The make_request_fn is a little weird in that it sits directly in
struct request_queue instead of an operation vector.  Replace it with
a block_device_operations method called submit_bio (which describes much
better what it does).  Also remove the request_queue argument to it, as
the queue can be derived pretty trivially from the bio.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 07:27:24 -06:00
Christoph Hellwig f695ca3886 block: remove the request_queue argument from blk_queue_split
The queue can be trivially derived from the bio, so pass one less
argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 07:27:23 -06:00
Ming Lei 37f4a24c24 blk-mq: centralise related handling into blk_mq_get_driver_tag
Move .nr_active update and request assignment into blk_mq_get_driver_tag(),
all are good to do during getting driver tag.

Meantime blk-flush related code is simplified and flush request needn't
to update the request table manually any more.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 12:57:59 -06:00
Ming Lei 723bf178f1 blk-mq: move blk_mq_put_driver_tag() into blk-mq.c
It is used by blk-mq.c only, so move it to the source file.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 12:57:59 -06:00
Ming Lei 570e9b73b0 blk-mq: move blk_mq_get_driver_tag into blk-mq.c
blk_mq_get_driver_tag() is only used by blk-mq.c and is supposed to
stay in blk-mq.c, so move it and preparing for cleanup code of
get/put driver tag.

Meantime hctx_may_queue() is moved to header file and it is fine
since it is defined as inline always.

No functional change.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 12:57:59 -06:00
Ming Lei 6e6fcbc27e blk-mq: support batching dispatch in case of io
More and more drivers want to get batching requests queued from
block layer, such as mmc, and tcp based storage drivers. Also
current in-tree users have virtio-scsi, virtio-blk and nvme.

For none, we already support batching dispatch.

But for io scheduler, every time we just take one request from scheduler
and pass the single request to blk_mq_dispatch_rq_list(). This way makes
batching dispatch not possible when io scheduler is applied. One reason
is that we don't want to hurt sequential IO performance, becasue IO
merge chance is reduced if more requests are dequeued from scheduler
queue.

Try to support batching dispatch for io scheduler by starting with the
following simple approach:

1) still make sure we can get budget before dequeueing request

2) use hctx->dispatch_busy to evaluate if queue is busy, if it is busy
we fackback to non-batching dispatch, otherwise dequeue as many as
possible requests from scheduler, and pass them to blk_mq_dispatch_rq_list().

Wrt. 2), we use similar policy for none, and turns out that SCSI SSD
performance got improved much.

In future, maybe we can develop more intelligent algorithem for batching
dispatch.

Baolin has tested this patch and found that MMC performance is improved[3].

[1] https://lore.kernel.org/linux-block/20200512075501.GF1531898@T590/#r
[2] https://lore.kernel.org/linux-block/fe6bd8b9-6ed9-b225-f80c-314746133722@grimberg.me/
[3] https://lore.kernel.org/linux-block/CADBw62o9eTQDJ9RvNgEqSpXmg6Xcq=2TxH0Hfxhp29uF2W=TXA@mail.gmail.com/

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 07:51:48 -06:00
Ming Lei 1fd40b5ea7 blk-mq: pass obtained budget count to blk_mq_dispatch_rq_list
Pass obtained budget count to blk_mq_dispatch_rq_list(), and prepare
for supporting fully batching submission.

With the obtained budget count, it is easier to put extra budgets
in case of .queue_rq failure.

Meantime remove the old 'got_budget' parameter.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 07:51:48 -06:00
Ming Lei bbdb3c5d94 blk-mq: remove dead check from blk_mq_dispatch_rq_list
When BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE is returned from
.queue_rq, the 'list' variable always holds this rq which isn't
queued to LLD successfully.

So blk_mq_dispatch_rq_list() always returns false from the branch
of '!list_empty(list)'.

No functional change.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 07:51:48 -06:00
Ming Lei 7538352453 blk-mq: move getting driver tag and budget into one helper
Move code for getting driver tag and budget into one helper, so
blk_mq_dispatch_rq_list gets a bit simplified, and easier to read.

Meantime move updating of 'no_tag' and 'no_budget_available' into
the branch for handling partial dispatch because that is exactly
consumer of the two local variables.

Also rename the parameter of 'got_budget' as 'ask_budget'.

No functional change.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 07:51:48 -06:00
Ming Lei 445874e89f blk-mq: pass hctx to blk_mq_dispatch_rq_list
All requests in the 'list' of blk_mq_dispatch_rq_list belong to same
hctx, so it is better to pass hctx instead of request queue, because
blk-mq's dispatch target is hctx instead of request queue.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 07:51:48 -06:00
Ming Lei 65c7636943 blk-mq: pass request queue into get/put budget callback
blk-mq budget is abstract from scsi's device queue depth, and it is
always per-request-queue instead of hctx.

It can be quite absurd to get a budget from one hctx, then dequeue a
request from scheduler queue, and this request may not belong to this
hctx, at least for bfq and deadline.

So fix the mess and always pass request queue to get/put budget
callback.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 07:51:48 -06:00
Christoph Hellwig 42fdc5e49c blk-mq: remove the BLK_MQ_REQ_INTERNAL flag
Just check for a non-NULL elevator directly to make the code more clear.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:56:18 -06:00
Ming Lei 36a3df5a45 blk-mq: put driver tag when this request is completed
It is natural to release driver tag when this request is completed by
LLD or device since its purpose is for LLD use.

One big benefit is that the released tag can be re-used quicker since
bio_endio() may take too long.

Meantime we don't need to release driver tag for flush request.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:56:10 -06:00
Christoph Hellwig 40d09b53bf blk-mq: add a new blk_mq_complete_request_remote API
This is a variant of blk_mq_complete_request_remote that only completes
the request if it needs to be bounced to another CPU or a softirq.  If
the request can be completed locally the function returns false and lets
the driver complete it without requring and indirect function call.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig 963395269c blk-mq: factor out a blk_mq_complete_need_ipi helper
Add a helper to decide if we can complete locally or need an IPI.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig 4c8fc19686 blk-mq: remove the get_cpu/put_cpu pair in blk_mq_complete_request
We don't really care if we get migrated during the I/O completion.
In the worth case we either perform an IPI that wasn't required, or
complete the request on a CPU which we just migrated off.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig 15f73f5b3e blk-mq: move failure injection out of blk_mq_complete_request
Move the call to blk_should_fake_timeout out of blk_mq_complete_request
and into the drivers, skipping call sites that are obvious error
handlers, and remove the now superflous blk_mq_force_complete_rq helper.
This ensures we don't keep injecting errors into completions that just
terminate the Linux request after the hardware has been reset or the
command has been aborted.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig d391a7a399 blk-mq: merge the softirq vs non-softirq IPI logic
Both the softirq path for single queue devices and the multi-queue
completion handler share the same logic to figure out if we need an
IPI for the completion and eventually issue it.  Merge the two
versions into a single unified code path.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig d6cc464cc5 blk-mq: short cut the IPI path in blk_mq_force_complete_rq for !SMP
Let the compile optimize out the entire IPI path, given that we are
obviously not going to use it.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00