Commit Graph

5298 Commits

Author SHA1 Message Date
Yang Yang
47ce030b7a blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue
blk_exit_queue will free elevator_data, while blk_mq_run_work_fn
will access it. Move cancel of hctx->run_work to the front of
blk_exit_queue to avoid use-after-free.

Fixes: 1b97871b50 ("blk-mq: move cancel of hctx->run_work into blk_mq_hw_sysfs_release")
Signed-off-by: Yang Yang <yang.yang@vivo.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-09 12:46:28 -06:00
Yufen Yu
c728152413 blk-mq: get rid of the dead flush handle code path
After commit 923218f616 ("blk-mq: don't allocate driver tag upfront
for flush rq"), blk_mq_submit_bio() will call blk_insert_flush()
directly to handle flush request rather than blk_mq_sched_insert_request()
in the case of elevator.

Then, all flush request either have set RQF_FLUSH_SEQ flag when call
blk_mq_sched_insert_request(), or have inserted into hctx->dispatch.
So, remove the dead code path.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-09 12:35:39 -06:00
Yufen Yu
0546858c59 block: get rid of unnecessary local variable
Since whole elevator register is protectd by sysfs_lock, we
don't need extras 'has_elevator'. Just use q->elevator directly.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-09 12:34:06 -06:00
Yufen Yu
f0c6ae09db block: fix comment and add lockdep assert
After commit b89f625e28 ("block: don't release queue's sysfs
lock during switching elevator"), whole elevator register and
unregister function are covered by sysfs_lock. So, remove wrong
comment and add lockdep assert.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-09 12:34:06 -06:00
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
Yufen Yu
75e6c00fc7 block: use helper function to test queue register
We have defined common interface blk_queue_registered() to
test QUEUE_FLAG_REGISTERED. Just use it.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-09 12:34:06 -06:00
Yufen Yu
6251b754f5 block: remove redundant mq check
elv_support_iosched() will check queue_is_mq() for us. So, remove
the redundant check to clean code.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-09 12:34:06 -06:00
Yufen Yu
dd1c372d65 block: invoke blk_mq_exit_sched no matter whether have .exit_sched
We will register debugfs for scheduler no matter whether it have
defined callback funciton .exit_sched. So, blk_mq_exit_sched()
is always needed to unregister debugfs. Also, q->elevator should
be set as NULL after exiting scheduler.

For now, since all register scheduler have defined .exit_sched,
it will not cause any actual problem. But It will be more reasonable
to do this change.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-09 12:34:06 -06:00
Linus Torvalds
583090b1b8 block5.9-2020-10-08
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Merge tag 'block5.9-2020-10-08' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "A few fixes that should go into this release:

   - NVMe controller error path reference fix (Chaitanya)

   - Fix regression with IBM partitions on non-dasd devices (Christoph)

   - Fix a missing clear in the compat CDROM packet structure (Peilin)"

* tag 'block5.9-2020-10-08' of git://git.kernel.dk/linux-block:
  partitions/ibm: fix non-DASD devices
  nvme-core: put ctrl ref when module ref get fail
  block/scsi-ioctl: Fix kernel-infoleak in scsi_put_cdrom_generic_arg()
2020-10-08 18:48:34 -07:00
Tetsuo Handa
f4ac712e4f block: ratelimit handle_bad_sector() message
syzbot is reporting unkillable task [1], for the caller is failing to
handle a corrupted filesystem image which attempts to access beyond
the end of the device. While we need to fix the caller, flooding the
console with handle_bad_sector() message is unlikely useful.

[1] https://syzkaller.appspot.com/bug?id=f1f49fb971d7a3e01bd8ab8cff2ff4572ccf3092

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-08 10:16:59 -06:00
Baolin Wang
1da30f952a blk-throttle: Re-use the throtl_set_slice_end()
Re-use throtl_set_slice_end() to remove duplicate code.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-08 08:01:38 -06:00
Baolin Wang
29379674bd blk-throttle: Open code __throtl_de/enqueue_tg()
The __throtl_de/enqueue_tg() functions are only be called by
throtl_de/enqueue_tg(), thus we can just open code them to
make code more readable.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-08 08:01:38 -06:00
Baolin Wang
2397611ac8 blk-throttle: Move service tree validation out of the throtl_rb_first()
The throtl_schedule_next_dispatch() will validate if the service queue
is empty before calling update_min_dispatch_time(), and the
update_min_dispatch_time() will call throtl_rb_first(), which will
validate service queue again.

Thus we can move the service queue validation out of the
throtl_rb_first() to remove the redundant validation in the fast path.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-08 08:01:38 -06:00
Baolin Wang
b7b609de5a blk-throttle: Move the list operation after list validation
We should move the list operation after validation.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-08 08:01:38 -06:00
Baolin Wang
5b7048b897 blk-throttle: Fix IO hang for a corner case
It can not scale up in throtl_adjusted_limit() if we set bps or iops is
1, which will cause IO hang when enable low limit. Thus we should treat
1 as a illegal value to avoid this issue.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-08 08:01:38 -06:00
Baolin Wang
b185efa78b blk-throttle: Avoid tracking latency if low limit is invalid
The IO latency tracking is only for LOW limit, so we should add a
validation to avoid redundant latency tracking if the LOW limit
is not valid.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-08 08:01:37 -06:00
Baolin Wang
7901601aef blk-throttle: Avoid getting the current time if tg->last_finish_time is 0
We only update the tg->last_finish_time when the low limitaion is
enabled, so we can move the tg->last_finish_time validation a little
forward to avoid getting the unnecessary current time stamp if the
the low limitation is not enabled.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-08 08:01:37 -06:00
Baolin Wang
4247d9c8ba blk-throttle: Remove a meaningless parameter for throtl_downgrade_state()
The throtl_downgrade_state() is always used to change to LIMIT_LOW
limitation, thus remove the latter meaningless parameter which
indicates the limitation index.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-08 08:01:37 -06:00
Baolin Wang
fa1c3eaf4d block: Remove redundant 'return' statement
Remove redundant 'return' statement for 'void' functions.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-08 07:59:48 -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
Christoph Hellwig
7370997d48 partitions/ibm: fix non-DASD devices
Don't error out if the dasd_biodasdinfo symbol is not available.

Cc: stable@vger.kernel.org
Fixes: 26d7e28e38 ("s390/dasd: remove ioctl_by_bdev calls")
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-07 07:55:35 -06:00
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
Christoph Hellwig
eda5cc997a block: move blk_mq_sched_try_merge to blk-merge.c
Move blk_mq_sched_try_merge to blk-merge.c, which allows to mark
a lot of the merge infrastructure static there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-06 07:29:53 -06:00
Christoph Hellwig
d59da41998 block: remove the unused blk_integrity_merge_bio export
Also move the definition from the public blkdev.h to the private
block/blk.h header.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-06 07:29:53 -06:00
Christoph Hellwig
92cf2fd156 block: remove the unused blk_integrity_merge_rq export
Also move the definition from the public blkdev.h to the private
block/blk.h header.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-06 07:29:53 -06:00
Eric Biggers
cf785af193 block: warn if !__GFP_DIRECT_RECLAIM in bio_crypt_set_ctx()
bio_crypt_set_ctx() assumes its gfp_mask argument always includes
__GFP_DIRECT_RECLAIM, so that the mempool_alloc() will always succeed.

For now this assumption is still fine, since no callers violate it.
Making bio_crypt_set_ctx() able to fail would add unneeded complexity.

However, if a caller didn't use __GFP_DIRECT_RECLAIM, it would be very
hard to notice the bug.  Make it easier by adding a WARN_ON_ONCE().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Satya Tangirala <satyat@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Satya Tangirala <satyat@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-05 10:47:43 -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
Eric Biggers
07560151db block: make bio_crypt_clone() able to fail
bio_crypt_clone() assumes its gfp_mask argument always includes
__GFP_DIRECT_RECLAIM, so that the mempool_alloc() will always succeed.

However, bio_crypt_clone() might be called with GFP_ATOMIC via
setup_clone() in drivers/md/dm-rq.c, or with GFP_NOWAIT via
kcryptd_io_read() in drivers/md/dm-crypt.c.

Neither case is currently reachable with a bio that actually has an
encryption context.  However, it's fragile to rely on this.  Just make
bio_crypt_clone() able to fail, analogous to bio_integrity_clone().

Reported-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Satya Tangirala <satyat@google.com>
Cc: Satya Tangirala <satyat@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-05 10:47:43 -06:00
Christoph Hellwig
10ed16662d block: add a bdget_part helper
All remaining callers of bdget() outside of fs/block_dev.c want to get a
reference to the struct block_device for a given struct hd_struct.  Add
a helper just for that and then mark bdget static.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-05 10:38:33 -06:00
Christoph Hellwig
89cd35c58b iov_iter: transparently handle compat iovecs in import_iovec
Use in compat_syscall to import either native or the compat iovecs, and
remove the now superflous compat_import_iovec.

This removes the need for special compat logic in most callers, and
the remaining ones can still be simplified by using __import_iovec
with a bool compat parameter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-10-03 00:02:13 -04:00
Gustavo A. R. Silva
f5ace5ef37 block: scsi_ioctl: Avoid the use of one-element arrays
One-element arrays are being deprecated[1]. Replace the one-element array
with a simple object of type compat_caddr_t: 'compat_caddr_t unused'[2],
once it seems this field is actually never used.

Also, update struct cdrom_generic_command in UAPI by adding an
anonimous union to avoid using the one-element array _reserved_.

[1] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays
[2] https://github.com/KSPP/linux/issues/86

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/lkml/5f76f5d0.qJ4t%2FHWuRzSW7bTa%25lkp@intel.com/
Build-tested-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-02 17:58:52 -06:00
Linus Torvalds
f016a54052 block-5.9-2020-10-02
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Merge tag 'block-5.9-2020-10-02' of git://git.kernel.dk/linux-block

Pull block fix from Jens Axboe:
 "Single fix for a ->commit_rqs failure case"

* tag 'block-5.9-2020-10-02' of git://git.kernel.dk/linux-block:
  blk-mq: call commit_rqs while list empty but error happen
2020-10-02 14:34:52 -07:00
Peilin Ye
6d53a9fe5a block/scsi-ioctl: Fix kernel-infoleak in scsi_put_cdrom_generic_arg()
scsi_put_cdrom_generic_arg() is copying uninitialized stack memory to
userspace, since the compiler may leave a 3-byte hole in the middle of
`cgc32`. Fix it by adding a padding field to `struct
compat_cdrom_generic_command`.

Cc: stable@vger.kernel.org
Fixes: f3ee6e63a9 ("compat_ioctl: move CDROM_SEND_PACKET handling into scsi")
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: syzbot+85433a479a646a064ab3@syzkaller.appspotmail.com
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-02 12:01:47 -06:00
Mike Snitzer
1471308fb5 Merge remote-tracking branch 'jens/for-5.10/block' into dm-5.10
DM depends on these block 5.10 commits:

22ada802ed block: use lcm_not_zero() when stacking chunk_sectors
07d098e6bb block: allow 'chunk_sectors' to be non-power-of-2
021a24460d block: add QUEUE_FLAG_NOWAIT
6abc49468e dm: add support for REQ_NOWAIT and enable it for linear target

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-09-29 16:31:35 -04:00
yangerkun
76cffccd60 block-mq: fix comments in blk_mq_queue_tag_busy_iter
'f5bbbbe4d635 ("blk-mq: sync the update nr_hw_queues with
blk_mq_queue_tag_busy_iter")' introduce a bug what we may sleep between
rcu lock. Then '530ca2c9bd69 ("blk-mq: Allow blocking queue tag iter
callbacks")' fix it by get request_queue's ref. And 'a9a808084d6a ("block:
Remove the synchronize_rcu() call from __blk_mq_update_nr_hw_queues()")'
remove the synchronize_rcu in __blk_mq_update_nr_hw_queues. We need
update the confused comments in blk_mq_queue_tag_busy_iter.

Signed-off-by: yangerkun <yangerkun@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-29 08:11:00 -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
Linus Torvalds
a1bffa4874 SCSI fixes on 20200926
Three fixes: one in drivers (lpfc) and two for zoned block devices.
 The latter also impinges on the block layer but only to introduce a
 new block API for setting the zone model rather than fiddling with the
 queue directly in the zoned block driver.
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
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Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI fixes from James Bottomley:
 "Three fixes: one in drivers (lpfc) and two for zoned block devices.

  The latter also impinges on the block layer but only to introduce a
  new block API for setting the zone model rather than fiddling with the
  queue directly in the zoned block driver"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: sd: sd_zbc: Fix ZBC disk initialization
  scsi: sd: sd_zbc: Fix handling of host-aware ZBC disks
  scsi: lpfc: Fix initial FLOGI failure due to BBSCN not supported
2020-09-26 11:18:37 -07:00
Tejun Heo
bec02dbbaf iocost: consider iocgs with active delays for debt forgiveness
An iocg may have 0 debt but non-zero delay. The current debt forgiveness
logic doesn't act on such iocgs. This can lead to unexpected behaviors - an
iocg with a little bit of debt will have its delay canceled through debt
forgiveness but one w/o any debt but active delay will have to wait out
until its delay decays out.

This patch updates the debt handling logic so that it treats delays the same
as debts. If either debt or delay is active, debt forgiveness logic kicks in
and acts on both the same way.

Also, avoid turning the debt and delay directly to zero as that can confuse
state transitions.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 08:35:02 -06:00
Tejun Heo
c5a6561b8d iocost: add iocg_forgive_debt tracepoint
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 08:35:02 -06:00
Tejun Heo
c7af2a003a iocost: reimplement debt forgiveness using average usage
Debt forgiveness logic was counting the number of consecutive !busy periods
as the trigger condition. While this usually works, it can easily be thrown
off by temporary fluctuations especially on configurations w/ short periods.

This patch reimplements debt forgiveness so that:

* Use the average usage over the forgiveness period instead of counting
  consecutive periods.

* Debt is reduced at around the target rate (1/2 every 100ms) regardless of
  ioc period duration.

* Usage threshold is raised to 50%. Combined with the preceding changes and
  the switch to average usage, this makes debt forgivness a lot more
  effective at reducing the amount of unnecessary idleness.

* Constants are renamed with DFGV_ prefix.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 08:35:02 -06:00
Tejun Heo
d95178410b iocost: recalculate delay after debt reduction
Debt sets the initial delay duration which is decayed over time. The current
debt reduction halved the debt but didn't change the delay. It prevented
future debts from increasing delay but didn't do anything to lower the
existing delay, limiting the mechanism's ability to reduce unnecessary
idling.

Reset iocg->delay to 0 after debt reduction so that iocg_kick_waitq()
recalculates new delay value based on the reduced debt amount.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 08:35:02 -06:00
Tejun Heo
33a1fe6d82 iocost: replace nr_shortages cond in ioc_forgive_debts() with busy_level one
Debt reduction was blocked if any iocg was short on budget in the past
period to avoid reducing debts while some iocgs are saturated. However, this
ends up unnecessarily blocking debt reduction due to temporary local
imbalances when the device is generally being underutilized, while also
failing to block when the underlying device is overwhelmed and the usage
becomes low from high latency.

Given that debt accumulation mostly happens with swapout bursts which can
significantly deteriorate the underlying device's latency response, the
current logic is not great.

Let's replace it with ioc->busy_level based condition so that we block debt
reduction when the underlying device is being saturated. ioc_forgive_debts()
call is moved after busy_level determination.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 08:35:02 -06:00
Tejun Heo
ab8df828b5 iocost: factor out ioc_forgive_debts()
Debt reduction logic is going to be improved and expanded. Factor it out
into ioc_forgive_debts() and generalize the comment a bit. No functional
change.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 08:35:02 -06:00
Mike Snitzer
021a24460d block: add QUEUE_FLAG_NOWAIT
Add QUEUE_FLAG_NOWAIT to allow a block device to advertise support for
REQ_NOWAIT. Bio-based devices may set QUEUE_FLAG_NOWAIT where
applicable.

Update QUEUE_FLAG_MQ_DEFAULT to include QUEUE_FLAG_NOWAIT.  Also
update submit_bio_checks() to verify it is set for REQ_NOWAIT bios.

Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 08:20:03 -06:00
Christoph Hellwig
8a63a86e1f block: use bd_partno in bdevname
No need to go through the hd_struct to find the partition number.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 08:18:58 -06:00
Christoph Hellwig
fa01b1e973 block: add a bdev_is_partition helper
Add a littler helper to make the somewhat arcane bd_contains checks a
little more obvious.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 08:18:57 -06:00
Jens Axboe
ac8f7a0264 Merge branch 'for-5.10/block' into for-5.10/drivers
* for-5.10/block: (140 commits)
  bdi: replace BDI_CAP_NO_{WRITEBACK,ACCT_DIRTY} with a single flag
  bdi: invert BDI_CAP_NO_ACCT_WB
  bdi: replace BDI_CAP_STABLE_WRITES with a queue and a sb flag
  mm: use SWP_SYNCHRONOUS_IO more intelligently
  bdi: remove BDI_CAP_SYNCHRONOUS_IO
  bdi: remove BDI_CAP_CGROUP_WRITEBACK
  block: lift setting the readahead size into the block layer
  md: update the optimal I/O size on reshape
  bdi: initialize ->ra_pages and ->io_pages in bdi_init
  aoe: set an optimal I/O size
  bcache: inherit the optimal I/O size
  drbd: remove dead code in device_to_statistics
  fs: remove the unused SB_I_MULTIROOT flag
  block: mark blkdev_get static
  PM: mm: cleanup swsusp_swap_check
  mm: split swap_type_of
  PM: rewrite is_hibernate_resume_dev to not require an inode
  mm: cleanup claim_swapfile
  ocfs2: cleanup o2hb_region_dev_store
  dasd: cleanup dasd_scan_partitions
  ...
2020-09-24 13:44:39 -06:00
Christoph Hellwig
1cb039f3dc bdi: replace BDI_CAP_STABLE_WRITES with a queue and a sb flag
The BDI_CAP_STABLE_WRITES is one of the few bits of information in the
backing_dev_info shared between the block drivers and the writeback code.
To help untangling the dependency replace it with a queue flag and a
superblock flag derived from it.  This also helps with the case of e.g.
a file system requiring stable writes due to its own checksumming, but
not forcing it on other users of the block device like the swap code.

One downside is that we an't support the stable_pages_required bdi
attribute in sysfs anymore.  It is replaced with a queue attribute which
also is writable for easier testing.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-24 13:43:39 -06:00
Christoph Hellwig
ed7b6b4f6e bdi: remove BDI_CAP_CGROUP_WRITEBACK
Just checking SB_I_CGROUPWB for cgroup writeback support is enough.
Either the file system allocates its own bdi (e.g. btrfs), in which case
it is known to support cgroup writeback, or the bdi comes from the block
layer, which always supports cgroup writeback.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-24 13:43:39 -06:00
Christoph Hellwig
c2e4cd57cf block: lift setting the readahead size into the block layer
Drivers shouldn't really mess with the readahead size, as that is a VM
concept.  Instead set it based on the optimal I/O size by lifting the
algorithm from the md driver when registering the disk.  Also set
bdi->io_pages there as well by applying the same scheme based on
max_sectors.  To ensure the limits work well for stacking drivers a
new helper is added to update the readahead limits from the block
limits, which is also called from disk_stack_limits.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-24 13:43:39 -06:00
Christoph Hellwig
55b2598e84 bdi: initialize ->ra_pages and ->io_pages in bdi_init
Set up a readahead size by default, as very few users have a good
reason to change it.  This means code, ecryptfs, and orangefs now
set up the values while they were previously missing it, while ubifs,
mtd and vboxsf manually set it to 0 to avoid readahead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Acked-by: Richard Weinberger <richard@nod.at> [ubifs, mtd]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-24 13:43:39 -06:00
Christoph Hellwig
478162821d block: cleanup blkdev_bszset
Use blkdev_get_by_dev instead of bdgrab + blkdev_get.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-23 10:43:19 -06:00
Christoph Hellwig
9301fe7343 block: cleanup partition scanning in register_disk
Use blkdev_get_by_dev instead of open coding it using bdget_disk +
blkdev_get, and split the code to read the partition table into a
separate helper to make it a little more obvious.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-23 10:43:19 -06:00
Christoph Hellwig
38430f0876 block: move the NEED_PART_SCAN flag to struct gendisk
We can only scan for partitions on the whole disk, so move the flag
from struct block_device to struct gendisk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-23 10:43:18 -06:00
Mike Snitzer
07d098e6bb block: allow 'chunk_sectors' to be non-power-of-2
It is possible, albeit more unlikely, for a block device to have a non
power-of-2 for chunk_sectors (e.g. 10+2 RAID6 with 128K chunk_sectors,
which results in a full-stripe size of 1280K. This causes the RAID6's
io_opt to be advertised as 1280K, and a stacked device _could_ then be
made to use a blocksize, aka chunk_sectors, that matches non power-of-2
io_opt of underlying RAID6 -- resulting in stacked device's
chunk_sectors being a non power-of-2).

Update blk_queue_chunk_sectors() and blk_max_size_offset() to
accommodate drivers that need a non power-of-2 chunk_sectors.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-23 10:38:14 -06:00
Mike Snitzer
22ada802ed block: use lcm_not_zero() when stacking chunk_sectors
Like 'io_opt', blk_stack_limits() should stack 'chunk_sectors' using
lcm_not_zero() rather than min_not_zero() -- otherwise the final
'chunk_sectors' could result in sub-optimal alignment of IO to
component devices in the IO stack.

Also, if 'chunk_sectors' isn't a multiple of 'physical_block_size'
then it is a bug in the driver and the device should be flagged as
'misaligned'.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-23 10:38:12 -06:00
Christoph Hellwig
0385971754 block: fix bmd->is_null_mapped initialization
bmd is allocated using kmalloc in bio_alloc_map_data, so make sure
is_null_mapped is properly initialized to false for the !null_mapped
case.

Fixes: f3256075ba ("block: remove the BIO_NULL_MAPPED flag")
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-23 09:18:39 -06:00
Julia Lawall
f952eefe74 block: drop double zeroing
sg_init_table zeroes its first argument, so the allocation of that argument
doesn't have to.

the semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x;
@@

x =
- kzalloc
+ kmalloc
 (...)
...
sg_init_table(x,...)
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-23 09:18:13 -06:00
Damien Le Moal
27ba3e8ff3 scsi: sd: sd_zbc: Fix handling of host-aware ZBC disks
When CONFIG_BLK_DEV_ZONED is disabled, allow using host-aware ZBC disks as
regular disks. In this case, ensure that command completion is correctly
executed by changing sd_zbc_complete() to return good_bytes instead of 0
and causing a hang during device probe (endless retries).

When CONFIG_BLK_DEV_ZONED is enabled and a host-aware disk is detected to
have partitions, it will be used as a regular disk. In this case, make sure
to not do anything in sd_zbc_revalidate_zones() as that triggers warnings.

Since all these different cases result in subtle settings of the disk queue
zoned model, introduce the block layer helper function
blk_queue_set_zoned() to generically implement setting up the effective
zoned model according to the disk type, the presence of partitions on the
disk and CONFIG_BLK_DEV_ZONED configuration.

Link: https://lore.kernel.org/r/20200915073347.832424-2-damien.lemoal@wdc.com
Fixes: b72053072c ("block: allow partitions on host aware zone devices")
Cc: <stable@vger.kernel.org>
Reported-by: Borislav Petkov <bp@alien8.de>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-09-15 20:08:14 -04:00
Baolin Wang
87fbeb8813 blk-throttle: Avoid checking bps/iops limitation if bps or iops is unlimited
Do not need check the bps or iops limitation if bps or iops is unlimited.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-14 19:36:54 -06:00
Baolin Wang
4599ea49d4 blk-throttle: Avoid calculating bps/iops limitation repeatedly
The tg_may_dispatch() will call tg_with_in_bps_limit() and
tg_with_in_iops_limit() to check if we can dispatch a bio or
not, which will calculate bps/iops limitation multiple times.
But tg_may_dispatch() is always called under queue lock, which
means the bps/iops limitation will not change in tg_may_dispatch().

So we can calculate the bps/iops limitation only once, and pass
them to tg_with_in_bps_limit() and tg_with_in_iops_limit() to
avoid calculating bps/iops limitation repeatedly.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-14 19:36:54 -06:00
Baolin Wang
e675df2adc blk-throttle: Define readable macros instead of static variables
The 'throtl_grp_quantum' and 'throtl_quantum' are both read-only
variables, thus better to use readable macros instead of static
variables, which can also save some spaces for .bss area.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-14 19:36:54 -06:00
Baolin Wang
ff8b22c0f2 blk-throttle: Use readable READ/WRITE macros
Use readable READ/WRITE macros instead of magic numbers.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-14 19:36:54 -06:00
Baolin Wang
b53b072c4b blk-throttle: Fix some comments' typos
Fix some comments' typos.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-14 19:36:54 -06:00
Tejun Heo
aa67db24b6 iocost: fix infinite loop bug in adjust_inuse_and_calc_cost()
adjust_inuse_and_calc_cost() is responsible for reducing the amount of
donated weights dynamically in period as the budget runs low. Because we
don't want to do full donation calculation in period, we keep latching up
inuse by INUSE_ADJ_STEP_PCT of the active weight of the cgroup until the
resulting hweight_inuse is satisfactory.

Unfortunately, the adj_step calculation was reading the active weight before
acquiring ioc->lock. Because the current thread could have lost race to
activate the iocg to another thread before entering this function, it may
read the active weight as zero before acquiring ioc->lock. When this
happens, the adj_step is calculated as zero and the incremental adjustment
loop becomes an infinite one.

Fix it by fetching the active weight after acquiring ioc->lock.

Fixes: b0853ab4a2 ("blk-iocost: revamp in-period donation snapbacks")
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-14 17:25:39 -06:00
Tejun Heo
769b628de0 blk-iocost: fix divide-by-zero in transfer_surpluses()
Conceptually, root_iocg->hweight_donating must be less than WEIGHT_ONE but
all hweight calculations round up and thus it may end up >= WEIGHT_ONE
triggering divide-by-zero and other issues. Bound the value to avoid
surprises.

Fixes: e08d02aa5f ("blk-iocost: implement Andy's method for donation weight updates")
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-11 16:41:47 -06:00
Song Liu
7b26410b05 block: introduce part_[begin|end]_io_acct
These functions can be used to enable iostat for partitions on devices
like md, bcache.

Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-11 16:41:30 -06:00
Linus Torvalds
7b8731d958 - Fix a regression in bdev partition locking (Christoph)
- NVMe pull request from Christoph:
 	- cancel async events before freeing them (David Milburn)
 	- revert a broken race fix (James Smart)
 	- fix command processing during resets (Sagi Grimberg)
 
 - Fix a kyber crash with requeued flushes (Omar)
 
 - Fix __bio_try_merge_page() same_page error for no merging (Ritesh)
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Merge tag 'block-5.9-2020-09-11' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Fix a regression in bdev partition locking (Christoph)

 - NVMe pull request from Christoph:
      - cancel async events before freeing them (David Milburn)
      - revert a broken race fix (James Smart)
      - fix command processing during resets (Sagi Grimberg)

 - Fix a kyber crash with requeued flushes (Omar)

 - Fix __bio_try_merge_page() same_page error for no merging (Ritesh)

* tag 'block-5.9-2020-09-11' of git://git.kernel.dk/linux-block:
  block: Set same_page to false in __bio_try_merge_page if ret is false
  nvme-fabrics: allow to queue requests for live queues
  block: only call sched requeue_request() for scheduled requests
  nvme-tcp: cancel async events before freeing event struct
  nvme-rdma: cancel async events before freeing event struct
  nvme-fc: cancel async events before freeing event struct
  nvme: Revert: Fix controller creation races with teardown flow
  block: restore a specific error code in bdev_del_partition
2020-09-11 11:55:28 -07:00
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
Tian Tao
84ed2573c5 block: remove duplicate include statement in scsi_ioctl.c
scsi/sg.h is included more than once, Remove the one that isn't
necessary.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-11 05:23:37 -06:00
Xianting Tian
192f1c6bc2 blkcg: add plugging support for punt bio
The test and the explaination of the patch as bellow.

Before test we added more debug code in blkg_async_bio_workfn():
	int count = 0
	if (bios.head && bios.head->bi_next) {
		need_plug = true;
		blk_start_plug(&plug);
	}
	while ((bio = bio_list_pop(&bios))) {
		/*io_punt is a sysctl user interface to control the print*/
		if(io_punt) {
			printk("[%s:%d] bio start,size:%llu,%d count=%d plug?%d\n",
				current->comm, current->pid, bio->bi_iter.bi_sector,
				(bio->bi_iter.bi_size)>>9, count++, need_plug);
		}
		submit_bio(bio);
	}
	if (need_plug)
		blk_finish_plug(&plug);

Steps that need to be set to trigger *PUNT* io before testing:
	mount -t btrfs -o compress=lzo /dev/sda6 /btrfs
	mount -t cgroup2 nodev /cgroup2
	mkdir /cgroup2/cg3
	echo "+io" > /cgroup2/cgroup.subtree_control
	echo "8:0 wbps=1048576000" > /cgroup2/cg3/io.max #1000M/s
	echo $$ > /cgroup2/cg3/cgroup.procs

Then use dd command to test btrfs PUNT io in current shell:
	dd if=/dev/zero of=/btrfs/file bs=64K count=100000

Test hardware environment as below:
	[root@localhost btrfs]# lscpu
	Architecture:          x86_64
	CPU op-mode(s):        32-bit, 64-bit
	Byte Order:            Little Endian
	CPU(s):                32
	On-line CPU(s) list:   0-31
	Thread(s) per core:    2
	Core(s) per socket:    8
	Socket(s):             2
	NUMA node(s):          2
	Vendor ID:             GenuineIntel

With above debug code, test command and test environment, I did the
tests under 3 different system loads, which are triggered by stress:
1, Run 64 threads by command "stress -c 64 &"
	[53615.975974] [kworker/u66:18:1490] bio start,size:45583056,8 count=0 plug?1
	[53615.975980] [kworker/u66:18:1490] bio start,size:45583064,8 count=1 plug?1
	[53615.975984] [kworker/u66:18:1490] bio start,size:45583072,8 count=2 plug?1
	[53615.975987] [kworker/u66:18:1490] bio start,size:45583080,8 count=3 plug?1
	[53615.975990] [kworker/u66:18:1490] bio start,size:45583088,8 count=4 plug?1
	[53615.975993] [kworker/u66:18:1490] bio start,size:45583096,8 count=5 plug?1
	... ...
	[53615.977041] [kworker/u66:18:1490] bio start,size:45585480,8 count=303 plug?1
	[53615.977044] [kworker/u66:18:1490] bio start,size:45585488,8 count=304 plug?1
	[53615.977047] [kworker/u66:18:1490] bio start,size:45585496,8 count=305 plug?1
	[53615.977050] [kworker/u66:18:1490] bio start,size:45585504,8 count=306 plug?1
	[53615.977053] [kworker/u66:18:1490] bio start,size:45585512,8 count=307 plug?1
	[53615.977056] [kworker/u66:18:1490] bio start,size:45585520,8 count=308 plug?1
	[53615.977058] [kworker/u66:18:1490] bio start,size:45585528,8 count=309 plug?1

2, Run 32 threads by command "stress -c 32 &"
	[50586.290521] [kworker/u66:6:32351] bio start,size:45806496,8 count=0 plug?1
	[50586.290526] [kworker/u66:6:32351] bio start,size:45806504,8 count=1 plug?1
	[50586.290529] [kworker/u66:6:32351] bio start,size:45806512,8 count=2 plug?1
	[50586.290531] [kworker/u66:6:32351] bio start,size:45806520,8 count=3 plug?1
	[50586.290533] [kworker/u66:6:32351] bio start,size:45806528,8 count=4 plug?1
	[50586.290535] [kworker/u66:6:32351] bio start,size:45806536,8 count=5 plug?1
	... ...
	[50586.299640] [kworker/u66:5:32350] bio start,size:45808576,8 count=252 plug?1
	[50586.299643] [kworker/u66:5:32350] bio start,size:45808584,8 count=253 plug?1
	[50586.299646] [kworker/u66:5:32350] bio start,size:45808592,8 count=254 plug?1
	[50586.299649] [kworker/u66:5:32350] bio start,size:45808600,8 count=255 plug?1
	[50586.299652] [kworker/u66:5:32350] bio start,size:45808608,8 count=256 plug?1
	[50586.299663] [kworker/u66:5:32350] bio start,size:45808616,8 count=257 plug?1
	[50586.299665] [kworker/u66:5:32350] bio start,size:45808624,8 count=258 plug?1
	[50586.299668] [kworker/u66:5:32350] bio start,size:45808632,8 count=259 plug?1

3, Don't run thread by stress
	[50861.355246] [kworker/u66:19:32376] bio start,size:13544504,8 count=0 plug?0
	[50861.355288] [kworker/u66:19:32376] bio start,size:13544512,8 count=0 plug?0
	[50861.355322] [kworker/u66:19:32376] bio start,size:13544520,8 count=0 plug?0
	[50861.355353] [kworker/u66:19:32376] bio start,size:13544528,8 count=0 plug?0
	[50861.355392] [kworker/u66:19:32376] bio start,size:13544536,8 count=0 plug?0
	[50861.355431] [kworker/u66:19:32376] bio start,size:13544544,8 count=0 plug?0
	[50861.355468] [kworker/u66:19:32376] bio start,size:13544552,8 count=0 plug?0
	[50861.355499] [kworker/u66:19:32376] bio start,size:13544560,8 count=0 plug?0
	[50861.355532] [kworker/u66:19:32376] bio start,size:13544568,8 count=0 plug?0
	[50861.355575] [kworker/u66:19:32376] bio start,size:13544576,8 count=0 plug?0
	[50861.355618] [kworker/u66:19:32376] bio start,size:13544584,8 count=0 plug?0
	[50861.355659] [kworker/u66:19:32376] bio start,size:13544592,8 count=0 plug?0
	[50861.355740] [kworker/u66:0:32346] bio start,size:13544600,8 count=0 plug?1
	[50861.355748] [kworker/u66:0:32346] bio start,size:13544608,8 count=1 plug?1
	[50861.355962] [kworker/u66:2:32347] bio start,size:13544616,8 count=0 plug?0
	[50861.356272] [kworker/u66:7:31962] bio start,size:13544624,8 count=0 plug?0
	[50861.356446] [kworker/u66:7:31962] bio start,size:13544632,8 count=0 plug?0
	[50861.356567] [kworker/u66:7:31962] bio start,size:13544640,8 count=0 plug?0
	[50861.356707] [kworker/u66:19:32376] bio start,size:13544648,8 count=0 plug?0
	[50861.356748] [kworker/u66:15:32355] bio start,size:13544656,8 count=0 plug?0
	[50861.356825] [kworker/u66:17:31970] bio start,size:13544664,8 count=0 plug?0

Analysis of above 3 test results with different system load:
>From above test, we can see more and more continuous bios can be plugged
with system load increasing. When run "stress -c 64 &", 310 continuous
bios are plugged; When run "stress -c 32 &", 260 continuous bios are
plugged; When don't run stress, at most only 2 continuous bios are
plugged, in most cases, bio_list only contains one single bio.

How to explain above phenomenon:
We know, in submit_bio(), if the bio is a REQ_CGROUP_PUNT io, it will
queue a work to workqueue blkcg_punt_bio_wq. But when the workqueue is
scheduled, it depends on the system load.  When system load is low, the
workqueue will be quickly scheduled, and the bio in bio_list will be
quickly processed in blkg_async_bio_workfn(), so there is less chance
that the same io submit thread can add multiple continuous bios to
bio_list before workqueue is scheduled to run. The analysis aligned with
above test "3".
When system load is high, there is some delay before the workqueue can
be scheduled to run, the higher the system load the greater the delay.
So there is more chance that the same io submit thread can add multiple
continuous bios to bio_list. Then when the workqueue is scheduled to run,
there are more continuous bios in bio_list, which will be processed in
blkg_async_bio_workfn(). The analysis aligned with above test "1" and "2".

According to test, we can get io performance improved with the patch,
especially when system load is higher. Another optimazition is to use
the plug only when bio_list contains at least 2 bios.

Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-10 09:56:34 -06:00
Christoph Hellwig
95f6f3a46f block: add a bdev_check_media_change helper
Like check_disk_changed, except that it does not call ->revalidate_disk
but leaves that to the caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-10 09:32:30 -06:00
Ritesh Harjani
2cd896a5e8 block: Set same_page to false in __bio_try_merge_page if ret is false
If we hit the UINT_MAX limit of bio->bi_iter.bi_size and so we are anyway
not merging this page in this bio, then it make sense to make same_page
also as false before returning.

Without this patch, we hit below WARNING in iomap.
This mostly happens with very large memory system and / or after tweaking
vm dirty threshold params to delay writeback of dirty data.

WARNING: CPU: 18 PID: 5130 at fs/iomap/buffered-io.c:74 iomap_page_release+0x120/0x150
 CPU: 18 PID: 5130 Comm: fio Kdump: loaded Tainted: G        W         5.8.0-rc3 #6
 Call Trace:
  __remove_mapping+0x154/0x320 (unreliable)
  iomap_releasepage+0x80/0x180
  try_to_release_page+0x94/0xe0
  invalidate_inode_page+0xc8/0x110
  invalidate_mapping_pages+0x1dc/0x540
  generic_fadvise+0x3c8/0x450
  xfs_file_fadvise+0x2c/0xe0 [xfs]
  vfs_fadvise+0x3c/0x60
  ksys_fadvise64_64+0x68/0xe0
  sys_fadvise64+0x28/0x40
  system_call_exception+0xf8/0x1c0
  system_call_common+0xf0/0x278

Fixes: cc90bc6842 ("block: fix "check bi_size overflow before merge"")
Reported-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-09 08:18:45 -06:00
Omar Sandoval
e8a8a18505 block: only call sched requeue_request() for scheduled requests
Yang Yang reported the following crash caused by requeueing a flush
request in Kyber:

  [    2.517297] Unable to handle kernel paging request at virtual address ffffffd8071c0b00
  ...
  [    2.517468] pc : clear_bit+0x18/0x2c
  [    2.517502] lr : sbitmap_queue_clear+0x40/0x228
  [    2.517503] sp : ffffff800832bc60 pstate : 00c00145
  ...
  [    2.517599] Process ksoftirqd/5 (pid: 51, stack limit = 0xffffff8008328000)
  [    2.517602] Call trace:
  [    2.517606]  clear_bit+0x18/0x2c
  [    2.517619]  kyber_finish_request+0x74/0x80
  [    2.517627]  blk_mq_requeue_request+0x3c/0xc0
  [    2.517637]  __scsi_queue_insert+0x11c/0x148
  [    2.517640]  scsi_softirq_done+0x114/0x130
  [    2.517643]  blk_done_softirq+0x7c/0xb0
  [    2.517651]  __do_softirq+0x208/0x3bc
  [    2.517657]  run_ksoftirqd+0x34/0x60
  [    2.517663]  smpboot_thread_fn+0x1c4/0x2c0
  [    2.517667]  kthread+0x110/0x120
  [    2.517669]  ret_from_fork+0x10/0x18

This happens because Kyber doesn't track flush requests, so
kyber_finish_request() reads a garbage domain token. Only call the
scheduler's requeue_request() hook if RQF_ELVPRIV is set (like we do for
the finish_request() hook in blk_mq_free_request()). Now that we're
handling it in blk-mq, also remove the check from BFQ.

Reported-by: Yang Yang <yang.yang@vivo.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-08 17:40:46 -06:00
Christoph Hellwig
fc93fe1453 block: make QUEUE_SYSFS_BIT_FNS more useful
Switch to the naming used by the other entries so that we can use the
QUEUE_RW_ENTRY helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-08 09:01:10 -06:00
Christoph Hellwig
3562614705 block: add helper macros for queue sysfs entries
Add two helpers macros to avoid boilerplate code for the queue sysfs
entries.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-08 09:01:10 -06:00
Christoph Hellwig
88ce2a530c block: restore a specific error code in bdev_del_partition
mdadm relies on the fact that deleting an invalid partition returns
-ENXIO or -ENOTTY to detect if a block device is a partition or a
whole device.

Fixes: 08fc1ab6d7 ("block: fix locking in bdev_del_partition")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-08 08:18:24 -06:00
Baolin Wang
ddfb8b0bed block: Remove unused blk_mq_sched_free_hctx_data()
Now we usually free the hctx->sched_data by e->type->ops.exit_hctx(),
and no users will use blk_mq_sched_free_hctx_data() function.
Remove it.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-07 20:11:15 -06:00
Jan Kara
384d87ef2c block: Do not discard buffers under a mounted filesystem
Discarding blocks and buffers under a mounted filesystem is hardly
anything admin wants to do. Usually it will confuse the filesystem and
sometimes the loss of buffer_head state (including b_private field) can
even cause crashes like:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
PGD 0 P4D 0
Oops: 0002 [#1] SMP PTI
CPU: 4 PID: 203778 Comm: jbd2/dm-3-8 Kdump: loaded Tainted: G O     --------- -  - 4.18.0-147.5.0.5.h126.eulerosv2r9.x86_64 #1
Hardware name: Huawei RH2288H V3/BC11HGSA0, BIOS 1.57 08/11/2015
RIP: 0010:jbd2_journal_grab_journal_head+0x1b/0x40 [jbd2]
...
Call Trace:
 __jbd2_journal_insert_checkpoint+0x23/0x70 [jbd2]
 jbd2_journal_commit_transaction+0x155f/0x1b60 [jbd2]
 kjournald2+0xbd/0x270 [jbd2]

So if we don't have block device open with O_EXCL already, claim the
block device while we truncate buffer cache. This makes sure any
exclusive block device user (such as filesystem) cannot operate on the
device while we are discarding buffer cache.

Reported-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[axboe: fix !CONFIG_BLOCK error in truncate_bdev_range()]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-07 20:10:55 -06:00
Linus Torvalds
8075fc3b11 block-5.9-2020-09-04
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Merge tag 'block-5.9-2020-09-04' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "A bit larger than usual this week, mostly due to the NVMe fixes
  arriving late for -rc3 and hence didn't make last weeks pull request.

   - NVMe:
        - instance leak and io boundary fixes from Keith
        - fc locking fix from Christophe
        - various tcp/rdma reset during traffic fixes from Sagi
        - pci use-after-free fix from Tong
        - tcp target null deref fix from Ziye

   - Locking fix for partition removal (Christoph)

   - Ensure bdi->io_pages is always set (me)

   - Fixup for hd struct reference (Ming)

   - Fix for zero length bvecs (Ming)

   - Two small blk-iocost fixes (Tejun)"

* tag 'block-5.9-2020-09-04' of git://git.kernel.dk/linux-block:
  block: allow for_each_bvec to support zero len bvec
  blk-stat: make q->stats->lock irqsafe
  blk-iocost: ioc_pd_free() shouldn't assume irq disabled
  block: fix locking in bdev_del_partition
  block: release disk reference in hd_struct_free_work
  block: ensure bdi->io_pages is always initialized
  nvme-pci: cancel nvme device request before disabling
  nvme: only use power of two io boundaries
  nvme: fix controller instance leak
  nvmet-fc: Fix a missed _irqsave version of spin_lock in 'nvmet_fc_fod_op_done()'
  nvme: Fix NULL dereference for pci nvme controllers
  nvme-rdma: fix reset hang if controller died in the middle of a reset
  nvme-rdma: fix timeout handler
  nvme-rdma: serialize controller teardown sequences
  nvme-tcp: fix reset hang if controller died in the middle of a reset
  nvme-tcp: fix timeout handler
  nvme-tcp: serialize controller teardown sequences
  nvme: have nvme_wait_freeze_timeout return if it timed out
  nvme-fabrics: don't check state NVME_CTRL_NEW for request acceptance
  nvmet-tcp: Fix NULL dereference when a connect data comes in h2cdata pdu
2020-09-04 13:04:51 -07:00
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
a0235d230f blk-mq: Relocate hctx_may_queue()
blk-mq.h and blk-mq-tag.h include on each other, which is less than ideal.

Locate hctx_may_queue() to blk-mq.h, as it is not really tag specific code.

In this way, we can drop the blk-mq-tag.h include of blk-mq.h

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
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
4d063237b9 blk-mq: Free tags in blk_mq_init_tags() upon error
Since the tags are allocated in blk_mq_init_tags(), it's better practice
to free in that same function upon error, rather than a callee which is to
init the bitmap tags (blk_mq_init_tags()).

[jpg: Split from an earlier patch with a new commit message]

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
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
Christoph Hellwig
b8086d3f5a block: use revalidate_disk_size in set_capacity_revalidate_and_notify
Only virtio_blk and xen-blkfront set the revalidate argument to true,
and both do not implement the ->revalidate_disk method.  So switch
to the helper that just updates the size instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-02 08:00:07 -06:00
Christoph Hellwig
f4ad06f2bb block: rename bd_invalidated
Replace bd_invalidate with a new BDEV_NEED_PART_SCAN flag in a bd_flags
variable to better describe the condition.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-02 08:00:02 -06:00
Baolin Wang
265600b7b6 block: Remove a duplicative condition
Remove a duplicative condition to remove below cppcheck warnings:

"warning: Redundant condition: sched_allow_merge. '!A || (A && B)' is
equivalent to '!A || B' [redundantCondition]"

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:48:06 -06:00
Ritika Srivastava
8327cce5ff block: better deal with the delayed not supported case in blk_cloned_rq_check_limits
If WRITE_ZERO/WRITE_SAME operation is not supported by the storage,
blk_cloned_rq_check_limits() will return IO error which will cause
device-mapper to fail the paths.

Instead, if the queue limit is set to 0, return BLK_STS_NOTSUPP.
BLK_STS_NOTSUPP will be ignored by device-mapper and will not fail the
paths.

Suggested-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ritika Srivastava <ritika.srivastava@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:33 -06:00
Ritika Srivastava
143d2600fa block: Return blk_status_t instead of errno codes
Replace returning legacy errno codes with blk_status_t in
blk_cloned_rq_check_limits().

Signed-off-by: Ritika Srivastava <ritika.srivastava@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:33 -06:00
Khazhismel Kumykov
9d3a39a5f1 block: grant IOPRIO_CLASS_RT to CAP_SYS_NICE
CAP_SYS_ADMIN is too broad, and ionice fits into CAP_SYS_NICE's grouping.

Retain CAP_SYS_ADMIN permission for backwards compatibility.

Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:33 -06:00
Tejun Heo
f0bf84a5df blk-iocost: add three debug stat - cost.wait, indebt and indelay
These are really cheap to collect and can be useful in debugging iocost
behavior. Add them as debug stats for now.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:33 -06:00
Tejun Heo
0460375517 blk-iocost: restore inuse update tracepoints
Update and restore the inuse update tracepoints.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:33 -06:00
Tejun Heo
ac33e91e2d blk-iocost: implement vtime loss compensation
When an iocg accumulates too much vtime or gets deactivated, we throw away
some vtime, which lowers the overall device utilization. As the exact amount
which is being thrown away is known, we can compensate by accelerating the
vrate accordingly so that the extra vtime generated in the current period
matches what got lost.

This significantly improves work conservation when involving high weight
cgroups with intermittent and bursty IO patterns.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:33 -06:00
Tejun Heo
dda1315f18 blk-iocost: halve debts if device stays idle
A low weight iocg can amass a large amount of debt, for example, when
anonymous memory gets reclaimed aggressively. If the system has a lot of
memory paired with a slow IO device, the debt can span multiple seconds or
more. If there are no other subsequent IO issuers, the in-debt iocg may end
up blocked paying its debt while the IO device is idle.

This patch implements a mechanism to protect against such pathological
cases. If the device has been sufficiently idle for a substantial amount of
time, the debts are halved. The criteria are on the conservative side as we
want to resolve the rare extreme cases without impacting regular operation
by forgiving debts too readily.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:33 -06:00
Tejun Heo
5160a5a53c blk-iocost: implement delay adjustment hysteresis
Curently, iocost syncs the delay duration to the outstanding debt amount,
which seemed enough to protect the system from anon memory hogs. However,
that was mostly because the delay calcuation was using hweight_inuse which
quickly converges towards zero under debt for delay duration calculation,
often pusnishing debtors overly harshly for longer than deserved.

The previous patch fixed the delay calcuation and now the protection against
anonymous memory hogs isn't enough because the effect of delay is indirect
and non-linear and a huge amount of future debt can accumulate abruptly
while unthrottled.

This patch implements delay hysteresis so that delay is decayed
exponentially over time instead of getting cleared immediately as debt is
paid off. While the overall behavior is similar to the blk-cgroup
implementation used by blk-iolatency, a lot of the details are different and
due to the empirical nature of the mechanism, it's challenging to adapt the
mechanism for one controller without negatively impacting the other.

As the delay is gradually decayed now, there's no point in running it from
its own hrtimer. Periodic updates are now performed from ioc_timer_fn() and
the dedicated hrtimer is removed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
c421a3eb2e blk-iocost: revamp debt handling
Debt handling had several issues.

* How much inuse a debtor carries wasn't clearly defined. inuse would be
  driven down over time from not issuing IOs but it'd be better to clamp it
  to minimum immediately once in debt.

* How much can be paid off was determined by hweight_inuse. As inuse was
  driven down, the payment amount would fall together regardless of the
  debtor's active weight. This means that the debtors were punished harshly.

* ioc_rqos_merge() wasn't calling blkcg_schedule_throttle() after
  iocg_kick_delay().

This patch revamps debt handling so that

* Debt handling owns inuse for iocgs in debt and keeps them at zero.

* Payment amount is determined by hweight_active. This is more deterministic
  and safer than hweight_inuse but still far from ideal in that it doesn't
  factor in possible donations from other iocgs for debt payments. This
  likely needs further improvements in the future.

* iocg_rqos_merge() now calls blkcg_schedule_throttle() as necessary.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andy Newell <newella@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
b0853ab4a2 blk-iocost: revamp in-period donation snapbacks
When the margin drops below the minimum on a donating iocg, donation is
immediately canceled in full. There are a couple shortcomings with the
current behavior.

* It's abrupt. A small temporary budget deficit can lead to a wide swing in
  weight allocation and a large surplus.

* It's open coded in the issue path but not implemented for the merge path.
  A series of merges at a low inuse can make the iocg incur debts and stall
  incorrectly.

This patch reimplements in-period donation snapbacks so that

* inuse adjustment and cost calculations are factored into
  adjust_inuse_and_calc_cost() which is called from both the issue and merge
  paths.

* Snapbacks are more gradual. It occurs in quarter steps.

* A snapback triggers if the margin goes below the low threshold and is
  lower than the budget at the time of the last adjustment.

* For the above, __propagate_weights() stores the margin in
  iocg->saved_margin. Move iocg->last_inuse storing together into
  __propagate_weights() for consistency.

* Full snapback is guaranteed when there are waiters.

* With precise donation and gradual snapbacks, inuse adjustments are now a
  lot more effective and the value of scaling inuse on weight changes isn't
  clear. Removed inuse scaling from weight_update().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
f1de2439ec blk-iocost: revamp donation amount determination
iocost has various safety nets to combat inuse adjustment calculation
inaccuracies. With Andy's method implemented in transfer_surpluses(), inuse
adjustment calculations are now accurate and we can make donation amount
determinations accurate too.

* Stop keeping track of past usage history and using the maximum. Act on the
  immediate usage information.

* Remove donation constraints defined by SURPLUS_* constants. Donate
  whatever isn't used.

* Determine the donation amount so that the iocg will end up with
  MARGIN_TARGET_PCT budget at the end of the coming period assuming the same
  usage as the previous period. TARGET is set at 50% of period, which is the
  previous maximum. This provides smooth convergence for most repetitive IO
  patterns.

* Apply donation logic early at 20% budget. There's no risk in doing so as
  the calculation is based on the delta between the current budget and the
  target budget at the end of the coming period.

* Remove preemptive iocg activation for zero cost IOs. As donation can reach
  near zero now, the mere activation doesn't provide any protection anymore.
  In the unlikely case that this becomes a problem, the right solution is
  assigning appropriate costs for such IOs.

This significantly improves the donation determination logic while also
simplifying it. Now all donations are immediate, exact and smooth.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andy Newell <newella@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
e08d02aa5f blk-iocost: implement Andy's method for donation weight updates
iocost implements work conservation by reducing iocg->inuse and propagating
the adjustment upwards proportionally. However, while I knew the target
absolute hierarchical proportion - adjusted hweight_inuse, I couldn't figure
out how to determine the iocg->inuse adjustment to achieve that and
approximated the adjustment by scaling iocg->inuse using the proportion of
the needed hweight_inuse changes.

When nested, these scalings aren't accurate even when adjusting a single
node as the donating node also receives the benefit of the donated portion.
When multiple nodes are donating as they often do, they can be wildly wrong.

iocost employed various safety nets to combat the inaccuracies. There are
ample buffers in determining how much to donate, the adjustments are
conservative and gradual. While it can achieve a reasonable level of work
conservation in simple scenarios, the inaccuracies can easily add up leading
to significant loss of total work. This in turn makes it difficult to
closely cap vrate as vrate adjustment is needed to compensate for the loss
of work. The combination of inaccurate donation calculations and vrate
adjustments can lead to wide fluctuations and clunky overall behaviors.

Andy Newell devised a method to calculate the needed ->inuse updates to
achieve the target hweight_inuse's. The method is compatible with the
proportional inuse adjustment propagation which allows all hot path
operations to be local to each iocg.

To roughly summarize, Andy's method divides the tree into donating and
non-donating parts, calculates global donation rate which is used to
determine the target hweight_inuse for each node, and then derives per-level
proportions. There's non-trivial amount of math involved. Please refer to
the following pdfs for detailed descriptions.

  https://drive.google.com/file/d/1PsJwxPFtjUnwOY1QJ5AeICCcsL7BM3bo
  https://drive.google.com/file/d/1vONz1-fzVO7oY5DXXsLjSxEtYYQbOvsE
  https://drive.google.com/file/d/1WcrltBOSPN0qXVdBgnKm4mdp9FhuEFQN

This patch implements Andy's method in transfer_surpluses(). This makes the
donation calculations accurate per cycle and enables further improvements in
other parts of the donation logic.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andy Newell <newella@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
93f7d2db80 blk-iocost: restructure surplus donation logic
The way the surplus donation logic is structured isn't great. There are two
separate paths for starting/increasing donations and decreasing them making
the logic harder to follow and is prone to unnecessary behavior differences.

In preparation for improved donation handling, this patch restructures the
code so that

* All donors - new, increasing and decreasing - are funneled through the
  same code path.

* The target donation calculation is factored into hweight_after_donation()
  which is called once from the same spot for all possible donors.

* Actual inuse adjustment is factored into trasnfer_surpluses().

This change introduces a few behavior differences - e.g. donation amount
reduction now uses the max usage of the recent three periods just like new
and increasing donations, and inuse now gets adjusted upwards the same way
it gets downwards. These differences are unlikely to have severely negative
implications and the whole logic will be revamped soon.

This patch also removes two tracepoints. The existing TPs don't quite fit
the new implementation. A later patch will update and reinstate them.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
065655c862 blk-iocost: decouple vrate adjustment from surplus transfers
Budget donations are inaccurate and could take multiple periods to converge.
To prevent triggering vrate adjustments while surplus transfers were
catching up, vrate adjustment was suppressed if donations were increasing,
which was indicated by non-zero nr_surpluses.

This entangling won't be necessary with the scheduled rewrite of donation
mechanism which will make it precise and immediate. Let's decouple the two
in preparation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
8692d2db8e blk-iocost: replace iocg->has_surplus with ->surplus_list
Instead of marking iocgs with surplus with a flag and filtering for them
while walking all active iocgs, build a surpluses list. This doesn't make
much difference now but will help implementing improved donation logic which
will iterate iocgs with surplus multiple times.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
1aa50d020c blk-iocost: calculate iocg->usages[] from iocg->local_stat.usage_us
Currently, iocg->usages[] which are used to guide inuse adjustments are
calculated from vtime deltas. This, however, assumes that the hierarchical
inuse weight at the time of calculation held for the entire period, which
often isn't true and can lead to significant errors.

Now that we have absolute usage information collected, we can derive
iocg->usages[] from iocg->local_stat.usage_us so that inuse adjustment
decisions are made based on actual absolute usage. The calculated usage is
clamped between 1 and WEIGHT_ONE and WEIGHT_ONE is also used to signal
saturation regardless of the current hierarchical inuse weight.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
97eb19751f blk-iocost: add absolute usage stat
Currently, iocost doesn't collect or expose any statistics punting off all
monitoring duties to drgn based iocost_monitor.py. While it works for some
scenarios, there are some usability and data availability challenges. For
example, accurate per-cgroup usage information can't be tracked by vtime
progression at all and the number available in iocg->usages[] are really
short-term snapshots used for control heuristics with possibly significant
errors.

This patch implements per-cgroup absolute usage stat counter and exposes it
through io.stat along with the current vrate. Usage stat collection and
flushing employ the same method as cgroup rstat on the active iocg's and the
only hot path overhead is preemption toggling and adding to a percpu
counter.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
da437b95db blk-iocost: grab ioc->lock for debt handling
Currently, debt handling requires only iocg->waitq.lock. In the future, we
want to adjust and propagate inuse changes depending on debt status. Let's
grab ioc->lock in debt handling paths in preparation.

* Because ioc->lock nests outside iocg->waitq.lock, the decision to grab
  ioc->lock needs to be made before entering the critical sections.

* Add and use iocg_[un]lock() which handles the conditional double locking.

* Add @pay_debt to iocg_kick_waitq() so that debt payment happens only when
  the caller grabbed both locks.

This patch is prepatory and the comments contain references to future
changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
7ca5b2e60b blk-iocost: streamline vtime margin and timer slack handling
The margin handling was pretty inconsistent.

* ioc->margin_us and ioc->inuse_margin_vtime were used as vtime margin
  thresholds. However, the two are in different units with the former
  requiring conversion to vtime on use.

* iocg_kick_waitq() was using a quarter of WAITQ_TIMER_MARGIN_PCT of
  period_us as the timer slack - ~1.2%. While iocg_kick_delay() was using a
  quarter of ioc->margin_us - ~12.5%. There aren't strong reasons to use
  different values for the two.

This patch cleans up margin and timer slack handling:

* vtime margins are now recorded in ioc->margins.{min, max} on period
  duration changes and used consistently.

* Timer slack is now 1% of period_us and recorded in ioc->timer_slack_ns and
  used consistently for iocg_kick_waitq() and iocg_kick_delay().

The only functional change is shortening of timer slack. No meaningful
visible change is expected.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
ce95570acf blk-iocost: make ioc_now->now and ioc->period_at 64bit
They are in microseconds and wrap in around 1.2 hours with u32. While
unlikely, confusions from wraparounds are still possible. We aren't saving
anything meaningful by keeping these u32. Let's make them u64.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
bd0adb91a6 blk-iocost: use WEIGHT_ONE based fixed point number for weights
To improve weight donations, we want to able to scale inuse with a greater
accuracy and down below 1. Let's make non-hierarchical weights to use
WEIGHT_ONE based fixed point numbers too like hierarchical ones.

This doesn't cause any behavior changes yet.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
fe20cdb516 blk-iocost: s/HWEIGHT_WHOLE/WEIGHT_ONE/g
We're gonna use HWEIGHT_WHOLE for regular weights too. Let's rename it to
WEIGHT_ONE.

Pure rename.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:32 -06:00
Tejun Heo
7b84b49e38 blk-iocost: make iocg_kick_waitq() call iocg_kick_delay() after paying debt
iocg_kick_waitq() is the function which pays debt and iocg_kick_delay()
updates the actual delay status accordingly. If iocg_kick_delay() is not
called after iocg_kick_delay() updated debt, unnecessarily large delays can
be applied temporarily.

Let's make sure such conditions don't occur by making iocg_kick_waitq()
always call iocg_kick_delay() after paying debt.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:31 -06:00
Tejun Heo
6ef20f787b blk-iocost: move iocg_kick_delay() above iocg_kick_waitq()
We'll make iocg_kick_waitq() call iocg_kick_delay(). Reorder them in
preparation. This is pure code reorganization.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:31 -06:00
Tejun Heo
db84a72af6 blk-iocost: clamp inuse and skip noops in __propagate_weights()
__propagate_weights() currently expects the callers to clamp inuse within
[1, active], which is needlessly fragile. The inuse adjustment logic is
going to be revamped, in preparation, let's make __propagate_weights() clamp
inuse on entry.

Also, make it avoid weight updates altogether if neither active or inuse is
changed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:31 -06:00
Tejun Heo
00410f1b09 blk-iocost: rename propagate_active_weights() to propagate_weights()
It already propagates two weights - active and inuse - and there will be
another soon. Let's drop the confusing misnomers. Rename
[__]propagate_active_weights() to [__]propagate_weights() and
commit_active_weights() to commit_weights().

This is pure rename.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:31 -06:00
Tejun Heo
5e124f7432 blk-iocost: use local[64]_t for percpu stat
blk-iocost has been reading percpu stat counters from remote cpus which on
some archs can lead to torn reads in really rare occassions. Use local[64]_t
for those counters.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:31 -06:00
Christoph Hellwig
1f06959bd2 block: remove the unused q argument to part_in_flight and part_in_flight_rw
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:31 -06:00
Christoph Hellwig
8328eb2836 block: remove the disk argument to delete_partition
We can trivially derive the gendisk from the hd_struct.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:25 -06:00
Christoph Hellwig
f93af2a494 block: cleanup __alloc_disk_node
Use early returns and goto-based unwinding to simplify the flow a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:26 -06:00
Christoph Hellwig
7cf34d97ab block: remove the discard_alignment field from struct hd_struct
The alignment offset is only used in slow path callers, so just calculate
it on the fly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:26 -06:00
Christoph Hellwig
7b8917f5e2 block: remove the alignment_offset field from struct hd_struct
The alignment offset is only used in slow path callers, so just calculate
it on the fly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:26 -06:00
Xianting Tian
e44a6a2359 blk-mq: use BLK_MQ_NO_TAG for no tag
Replace various magic -1 constants for tags with BLK_MQ_NO_TAG.

Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:26 -06:00
Baolin Wang
cdfcef9ee8 block: Remove blk_mq_attempt_merge() function
The small blk_mq_attempt_merge() function is only called by
__blk_mq_sched_bio_merge(), just open code it.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:26 -06:00
Baolin Wang
7d7ca7c526 block: Add a new helper to attempt to merge a bio
There are lots of duplicated code when trying to merge a bio from
plug list and sw queue, we can introduce a new helper to attempt
to merge a bio, which can simplify the blk_bio_list_merge()
and blk_attempt_plug_merge().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:26 -06:00
Baolin Wang
bdc6a287bc block: Move blk_mq_bio_list_merge() into blk-merge.c
Move the blk_mq_bio_list_merge() into blk-merge.c and
rename it as a generic name.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:26 -06:00
Baolin Wang
8e756373d7 block: Move bio merge related functions into blk-merge.c
It's better to move bio merge related functions into blk-merge.c,
which contains all merge related functions.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:26 -06:00
Danny Lin
339b5a25c2 blk-wbt: Remove obsolete multiqueue I/O scheduling comment
This comment was added before the multiqueue I/O scheduler framework
was introduced; multiqueue has support for I/O scheduling now, so this
obsolete comment can be removed.

Signed-off-by: Danny Lin <danny@kdrag0n.dev>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:26 -06:00
Christoph Hellwig
3310eebafe block: remove the BIO_USER_MAPPED flag
Just check if there is private data, in which case the bio must have
originated from bio_copy_user_iov.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:26 -06:00
Christoph Hellwig
7589ad6729 block: remove __blk_rq_map_user_iov
Just duplicate a small amount of code in the low-level map into the bio
and copy to the bio routines, leading to much easier to follow and
maintain code, and better shared error handling.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:25 -06:00
Christoph Hellwig
7b63c052a5 block: remove __blk_rq_unmap_user
Open code __blk_rq_unmap_user in the two callers.  Both never pass a NULL
bio, and one of them can use an existing local variable instead of the bio
flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:25 -06:00
Christoph Hellwig
f3256075ba block: remove the BIO_NULL_MAPPED flag
We can simply use a boolean flag in the bio_map_data data structure
instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:25 -06:00
Christoph Hellwig
c2b4bb8cb3 block: fix locking for struct block_device size updates
Two different callers use two different mutexes for updating the
block device size, which obviously doesn't help to actually protect
against concurrent updates from the different callers.  In addition
one of the locks, bd_mutex is rather prone to deadlocks with other
parts of the block stack that use it for high level synchronization.

Switch to using a new spinlock protecting just the size updates, as
that is all we need, and make sure everyone does the update through
the proper helper.

This fixes a bug reported with the nvme revalidating disks during a
hot removal operation, which can currently deadlock on bd_mutex.

Reported-by: Xianting Tian <xianting_tian@126.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:25 -06:00
Jens Axboe
a98278ecfb Merge branch 'block-5.9' into for-5.10/block
* block-5.9:
  blk-stat: make q->stats->lock irqsafe
  blk-iocost: ioc_pd_free() shouldn't assume irq disabled
  block: fix locking in bdev_del_partition
  block: release disk reference in hd_struct_free_work
  block: ensure bdi->io_pages is always initialized
  nvme-pci: cancel nvme device request before disabling
  nvme: only use power of two io boundaries
  nvme: fix controller instance leak
  nvmet-fc: Fix a missed _irqsave version of spin_lock in 'nvmet_fc_fod_op_done()'
  nvme: Fix NULL dereference for pci nvme controllers
  nvme-rdma: fix reset hang if controller died in the middle of a reset
  nvme-rdma: fix timeout handler
  nvme-rdma: serialize controller teardown sequences
  nvme-tcp: fix reset hang if controller died in the middle of a reset
  nvme-tcp: fix timeout handler
  nvme-tcp: serialize controller teardown sequences
  nvme: have nvme_wait_freeze_timeout return if it timed out
  nvme-fabrics: don't check state NVME_CTRL_NEW for request acceptance
  nvmet-tcp: Fix NULL dereference when a connect data comes in h2cdata pdu
2020-09-01 16:49:20 -06:00
Tejun Heo
e11d80a849 blk-stat: make q->stats->lock irqsafe
blk-iocost calls blk_stat_enable_accounting() while holding an irqsafe lock
which triggers a lockdep splat because q->stats->lock isn't irqsafe. Let's
make it irqsafe.

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: cd006509b0 ("blk-iocost: account for IO size when testing latencies")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:48:46 -06:00
Tejun Heo
5aeac7c4b1 blk-iocost: ioc_pd_free() shouldn't assume irq disabled
ioc_pd_free() grabs irq-safe ioc->lock without ensuring that irq is disabled
when it can be called with irq disabled or enabled. This has a small chance
of causing A-A deadlocks and triggers lockdep splats. Use irqsave operations
instead.

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 7caa47151a ("blkcg: implement blk-iocost")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:48:44 -06:00
Christoph Hellwig
08fc1ab6d7 block: fix locking in bdev_del_partition
We need to hold the whole device bd_mutex to protect against
other thread concurrently deleting out partition before we get
to it, and thus causing a use after free.

Fixes: cddae808ae ("block: pass a hd_struct to delete_partition")
Reported-by: syzbot+6448f3c229bc52b82f69@syzkaller.appspotmail.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 08:35:35 -06:00
Ming Lei
cafe01ef8f block: release disk reference in hd_struct_free_work
Commit e8c7d14ac6 ("block: revert back to synchronous request_queue removal")
stops to release request queue from wq context because that commit
supposed all blk_put_queue() is called in context which is allowed
to sleep. However, this assumption isn't true because we release disk's
reference in partition's percpu_ref's ->release() which doesn't allow
to sleep, because the ->release() is run via call_rcu().

Fixes this issue by moving put disk reference into hd_struct_free_work()

Fixes: e8c7d14ac6 ("block: revert back to synchronous request_queue removal")
Reported-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 08:34:08 -06:00
Jens Axboe
de1b0ee490 block: ensure bdi->io_pages is always initialized
If a driver leaves the limit settings as the defaults, then we don't
initialize bdi->io_pages. This means that file systems may need to
work around bdi->io_pages == 0, which is somewhat messy.

Initialize the default value just like we do for ->ra_pages.

Cc: stable@vger.kernel.org
Fixes: 9491ae4aad ("mm: don't cap request size based on read-ahead setting")
Reported-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 08:00:14 -06:00
Linus Torvalds
c41c3ec4a2 io_uring-5.9-2020-08-23
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Merge tag 'io_uring-5.9-2020-08-23' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - NVMe pull request from Sagi:
       - nvme completion rework from Christoph and Chao that mostly came
         from a bit of divergence of how we classify errors related to
         pathing/retry etc.
       - nvmet passthru fixes from Chaitanya
       - minor nvmet fixes from Amit and I
       - mpath round-robin path selection fix from Martin
       - ignore noiob for zoned devices from Keith
       - minor nvme-fc fix from Tianjia"

 - BFQ cgroup leak fix (Dmitry)

 - block layer MAINTAINERS addition (Geert)

 - fix null_blk FUA checking (Hou)

 - get_max_io_size() size fix (Keith)

 - fix block page_is_mergeable() for compound pages (Matthew)

 - discard granularity fixes (Ming)

 - IO scheduler ordering fix (Ming)

 - misc fixes

* tag 'io_uring-5.9-2020-08-23' of git://git.kernel.dk/linux-block: (31 commits)
  null_blk: fix passing of REQ_FUA flag in null_handle_rq
  nvmet: Disable keep-alive timer when kato is cleared to 0h
  nvme: redirect commands on dying queue
  nvme: just check the status code type in nvme_is_path_error
  nvme: refactor command completion
  nvme: rename and document nvme_end_request
  nvme: skip noiob for zoned devices
  nvme-pci: fix PRP pool size
  nvme-pci: Use u32 for nvme_dev.q_depth and nvme_queue.q_depth
  nvme: Use spin_lock_irq() when taking the ctrl->lock
  nvmet: call blk_mq_free_request() directly
  nvmet: fix oops in pt cmd execution
  nvmet: add ns tear down label for pt-cmd handling
  nvme: multipath: round-robin: eliminate "fallback" variable
  nvme: multipath: round-robin: fix single non-optimized path case
  nvme-fc: Fix wrong return value in __nvme_fc_init_request()
  nvmet-passthru: Reject commands with non-sgl flags set
  nvmet: fix a memory leak
  blkcg: fix memleak for iolatency
  MAINTAINERS: Add missing header files to BLOCK LAYER section
  ...
2020-08-24 11:53:15 -07:00
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Yufen Yu
27029b4b18 blkcg: fix memleak for iolatency
Normally, blkcg_iolatency_exit() will free related memory in iolatency
when cleanup queue. But if blk_throtl_init() return error and queue init
fail, blkcg_iolatency_exit() will not do that for us. Then it cause
memory leak.

Fixes: d706751215 ("block: introduce blk-iolatency io controller")
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-21 17:14:27 -06:00
Keith Busch
e4b469c66f block: fix get_max_io_size()
A previous commit aligning splits to physical block sizes inadvertently
modified one return case such that that it now returns 0 length splits
when the number of sectors doesn't exceed the physical offset. This
later hits a BUG in bio_split(). Restore the previous working behavior.

Fixes: 9cc5169cd4 ("block: Improve physical block alignment of split bios")
Reported-by: Eric Deal <eric.deal@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-21 17:09:22 -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
Dmitry Monakhov
2de791ab49 bfq: fix blkio cgroup leakage v4
Changes from v1:
    - update commit description with proper ref-accounting justification

commit db37a34c56 ("block, bfq: get a ref to a group when adding it to a service tree")
introduce leak forbfq_group and blkcg_gq objects because of get/put
imbalance.
In fact whole idea of original commit is wrong because bfq_group entity
can not dissapear under us because it is referenced by child bfq_queue's
entities from here:
 -> bfq_init_entity()
    ->bfqg_and_blkg_get(bfqg);
    ->entity->parent = bfqg->my_entity

 -> bfq_put_queue(bfqq)
    FINAL_PUT
    ->bfqg_and_blkg_put(bfqq_group(bfqq))
    ->kmem_cache_free(bfq_pool, bfqq);

So parent entity can not disappear while child entity is in tree,
and child entities already has proper protection.
This patch revert commit db37a34c56 ("block, bfq: get a ref to a group when adding it to a service tree")

bfq_group leak trace caused by bad commit:
-> blkg_alloc
   -> bfq_pq_alloc
     -> bfqg_get (+1)
->bfq_activate_bfqq
  ->bfq_activate_requeue_entity
    -> __bfq_activate_entity
       ->bfq_get_entity
         ->bfqg_and_blkg_get (+1)  <==== : Note1
->bfq_del_bfqq_busy
  ->bfq_deactivate_entity+0x53/0xc0 [bfq]
    ->__bfq_deactivate_entity+0x1b8/0x210 [bfq]
      -> bfq_forget_entity(is_in_service = true)
	 entity->on_st_or_in_serv = false   <=== :Note2
	 if (is_in_service)
	     return;  ==> do not touch reference
-> blkcg_css_offline
 -> blkcg_destroy_blkgs
  -> blkg_destroy
   -> bfq_pd_offline
    -> __bfq_deactivate_entity
         if (!entity->on_st_or_in_serv) /* true, because (Note2)
		return false;
 -> bfq_pd_free
    -> bfqg_put() (-1, byt bfqg->ref == 2) because of (Note2)
So bfq_group and blkcg_gq  will leak forever, see test-case below.

##TESTCASE_BEGIN:
#!/bin/bash

max_iters=${1:-100}
#prep cgroup mounts
mount -t tmpfs cgroup_root /sys/fs/cgroup
mkdir /sys/fs/cgroup/blkio
mount -t cgroup -o blkio none /sys/fs/cgroup/blkio

# Prepare blkdev
grep blkio /proc/cgroups
truncate -s 1M img
losetup /dev/loop0 img
echo bfq > /sys/block/loop0/queue/scheduler

grep blkio /proc/cgroups
for ((i=0;i<max_iters;i++))
do
    mkdir -p /sys/fs/cgroup/blkio/a
    echo 0 > /sys/fs/cgroup/blkio/a/cgroup.procs
    dd if=/dev/loop0 bs=4k count=1 of=/dev/null iflag=direct 2> /dev/null
    echo 0 > /sys/fs/cgroup/blkio/cgroup.procs
    rmdir /sys/fs/cgroup/blkio/a
    grep blkio /proc/cgroups
done
##TESTCASE_END:

Fixes: db37a34c56 ("block, bfq: get a ref to a group when adding it to a service tree")
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-18 07:48:08 -07:00
Matthew Wilcox (Oracle)
d81665198b block: Fix page_is_mergeable() for compound pages
If we pass in an offset which is larger than PAGE_SIZE, then
page_is_mergeable() thinks it's not mergeable with the previous bio_vec,
leading to a large number of bio_vecs being used.  Use a slightly more
obvious test that the two pages are compatible with each other.

Fixes: 52d52d1c98 ("block: only allow contiguous page structs in a bio_vec")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-17 19:35:53 -07:00