linux-stable.git/drivers/md/bcache, branch v5.12.2

block: rename BIO_MAX_PAGES to BIO_MAX_VECS

2021-03-11T14:47:48+00:00

Ever since the addition of multipage bio_vecs BIO_MAX_PAGES has been
horribly confusingly misnamed.  Rename it to BIO_MAX_VECS to stop
confusing users of the bio API.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Matthew Wilcox (Oracle) 
Reviewed-by: Martin K. Petersen 
Link: https://lore.kernel.org/r/20210311110137.1132391-2-hch@lst.de
Signed-off-by: Jens Axboe

Merge tag 'for-5.12/drivers-2021-02-17' of git://git.kernel.dk/linux-block

2021-02-21T19:06:54+00:00

Pull block driver updates from Jens Axboe:

 - Remove the skd driver. It's been EOL for a long time (Damien)

 - NVMe pull requests
      - fix multipath handling of ->queue_rq errors (Chao Leng)
      - nvmet cleanups (Chaitanya Kulkarni)
      - add a quirk for buggy Amazon controller (Filippo Sironi)
      - avoid devm allocations in nvme-hwmon that don't interact well
        with fabrics (Hannes Reinecke)
      - sysfs cleanups (Jiapeng Chong)
      - fix nr_zones for multipath (Keith Busch)
      - nvme-tcp crash fix for no-data commands (Sagi Grimberg)
      - nvmet-tcp fixes (Sagi Grimberg)
      - add a missing __rcu annotation (Christoph)
      - failed reconnect fixes (Chao Leng)
      - various tracing improvements (Michal Krakowiak, Johannes
        Thumshirn)
      - switch the nvmet-fc assoc_list to use RCU protection (Leonid
        Ravich)
      - resync the status codes with the latest spec (Max Gurtovoy)
      - minor nvme-tcp improvements (Sagi Grimberg)
      - various cleanups (Rikard Falkeborn, Minwoo Im, Chaitanya
        Kulkarni, Israel Rukshin)

 - Floppy O_NDELAY fix (Denis)

 - MD pull request
      - raid5 chunk_sectors fix (Guoqing)

 - Use lore links (Kees)

 - Use DEFINE_SHOW_ATTRIBUTE for nbd (Liao)

 - loop lock scaling (Pavel)

 - mtip32xx PCI fixes (Bjorn)

 - bcache fixes (Kai, Dongdong)

 - Misc fixes (Tian, Yang, Guoqing, Joe, Andy)

* tag 'for-5.12/drivers-2021-02-17' of git://git.kernel.dk/linux-block: (64 commits)
  lightnvm: pblk: Replace guid_copy() with export_guid()/import_guid()
  lightnvm: fix unnecessary NULL check warnings
  nvme-tcp: fix crash triggered with a dataless request submission
  block: Replace lkml.org links with lore
  nbd: Convert to DEFINE_SHOW_ATTRIBUTE
  nvme: add 48-bit DMA address quirk for Amazon NVMe controllers
  nvme-hwmon: rework to avoid devm allocation
  nvmet: remove else at the end of the function
  nvmet: add nvmet_req_subsys() helper
  nvmet: use min of device_path and disk len
  nvmet: use invalid cmd opcode helper
  nvmet: use invalid cmd opcode helper
  nvmet: add helper to report invalid opcode
  nvmet: remove extra variable in id-ns handler
  nvmet: make nvmet_find_namespace() req based
  nvmet: return uniform error for invalid ns
  nvmet: set status to 0 in case for invalid nsid
  nvmet-fc: add a missing __rcu annotation to nvmet_fc_tgt_assoc.queues
  nvme-multipath: set nr_zones for zoned namespaces
  nvmet-tcp: fix potential race of tcp socket closing accept_work
  ...

Merge tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block

2021-02-21T19:02:48+00:00

Pull core block updates from Jens Axboe:
 "Another nice round of removing more code than what is added, mostly
  due to Christoph's relentless pursuit of tech debt removal/cleanups.
  This pull request contains:

   - Two series of BFQ improvements (Paolo, Jan, Jia)

   - Block iov_iter improvements (Pavel)

   - bsg error path fix (Pan)

   - blk-mq scheduler improvements (Jan)

   - -EBUSY discard fix (Jan)

   - bvec allocation improvements (Ming, Christoph)

   - bio allocation and init improvements (Christoph)

   - Store bdev pointer in bio instead of gendisk + partno (Christoph)

   - Block trace point cleanups (Christoph)

   - hard read-only vs read-only split (Christoph)

   - Block based swap cleanups (Christoph)

   - Zoned write granularity support (Damien)

   - Various fixes/tweaks (Chunguang, Guoqing, Lei, Lukas, Huhai)"

* tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block: (104 commits)
  mm: simplify swapdev_block
  sd_zbc: clear zone resources for non-zoned case
  block: introduce blk_queue_clear_zone_settings()
  zonefs: use zone write granularity as block size
  block: introduce zone_write_granularity limit
  block: use blk_queue_set_zoned in add_partition()
  nullb: use blk_queue_set_zoned() to setup zoned devices
  nvme: cleanup zone information initialization
  block: document zone_append_max_bytes attribute
  block: use bi_max_vecs to find the bvec pool
  md/raid10: remove dead code in reshape_request
  block: mark the bio as cloned in bio_iov_bvec_set
  block: set BIO_NO_PAGE_REF in bio_iov_bvec_set
  block: remove a layer of indentation in bio_iov_iter_get_pages
  block: turn the nr_iovecs argument to bio_alloc* into an unsigned short
  block: remove the 1 and 4 vec bvec_slabs entries
  block: streamline bvec_alloc
  block: factor out a bvec_alloc_gfp helper
  block: move struct biovec_slab to bio.c
  block: reuse BIO_INLINE_VECS for integrity bvecs
  ...

bcache: Avoid comma separated statements

2021-02-10T15:06:00+00:00

Use semicolons and braces.

Signed-off-by: Joe Perches 
Signed-off-by: Coly Li 
Signed-off-by: Jens Axboe

bcache: Move journal work to new flush wq

2021-02-10T15:06:00+00:00

This is potentially long running and not latency sensitive, let's get
it out of the way of other latency sensitive events.

As observed in the previous commit, the `system_wq` comes easily
congested by bcache, and this fixes a few more stalls I was observing
every once in a while.

Let's not make this `WQ_MEM_RECLAIM` as it showed to reduce performance
of boot and file system operations in my tests. Also, without
`WQ_MEM_RECLAIM`, I no longer see desktop stalls. This matches the
previous behavior as `system_wq` also does no memory reclaim:

> // workqueue.c:
> system_wq = alloc_workqueue("events", 0, 0);

Cc: Coly Li 
Cc: stable@vger.kernel.org # 5.4+
Signed-off-by: Kai Krakow 
Signed-off-by: Coly Li 
Signed-off-by: Jens Axboe

bcache: Give btree_io_wq correct semantics again

2021-02-10T15:06:00+00:00

Before killing `btree_io_wq`, the queue was allocated using
`create_singlethread_workqueue()` which has `WQ_MEM_RECLAIM`. After
killing it, it no longer had this property but `system_wq` is not
single threaded.

Let's combine both worlds and make it multi threaded but able to
reclaim memory.

Cc: Coly Li 
Cc: stable@vger.kernel.org # 5.4+
Signed-off-by: Kai Krakow 
Signed-off-by: Coly Li 
Signed-off-by: Jens Axboe

Revert "bcache: Kill btree_io_wq"

2021-02-10T15:06:00+00:00

This reverts commit 56b30770b27d54d68ad51eccc6d888282b568cee.

With the btree using the `system_wq`, I seem to see a lot more desktop
latency than I should.

After some more investigation, it looks like the original assumption
of 56b3077 no longer is true, and bcache has a very high potential of
congesting the `system_wq`. In turn, this introduces laggy desktop
performance, IO stalls (at least with btrfs), and input events may be
delayed.

So let's revert this. It's important to note that the semantics of
using `system_wq` previously mean that `btree_io_wq` should be created
before and destroyed after other bcache wqs to keep the same
assumptions.

Cc: Coly Li 
Cc: stable@vger.kernel.org # 5.4+
Signed-off-by: Kai Krakow 
Signed-off-by: Coly Li 
Signed-off-by: Jens Axboe

bcache: Fix register_device_aync typo

2021-02-10T15:06:00+00:00

Should be `register_device_async`.

Cc: Coly Li 
Signed-off-by: Kai Krakow 
Signed-off-by: Coly Li 
Signed-off-by: Jens Axboe

bcache: consider the fragmentation when update the writeback rate

2021-02-10T15:05:59+00:00

Current way to calculate the writeback rate only considered the
dirty sectors, this usually works fine when the fragmentation
is not high, but it will give us unreasonable small rate when
we are under a situation that very few dirty sectors consumed
a lot dirty buckets. In some case, the dirty bucekts can reached
to CUTOFF_WRITEBACK_SYNC while the dirty data(sectors) not even
reached the writeback_percent, the writeback rate will still
be the minimum value (4k), thus it will cause all the writes to be
stucked in a non-writeback mode because of the slow writeback.

We accelerate the rate in 3 stages with different aggressiveness,
the first stage starts when dirty buckets percent reach above
BCH_WRITEBACK_FRAGMENT_THRESHOLD_LOW (50), the second is
BCH_WRITEBACK_FRAGMENT_THRESHOLD_MID (57), the third is
BCH_WRITEBACK_FRAGMENT_THRESHOLD_HIGH (64). By default
the first stage tries to writeback the amount of dirty data
in one bucket (on average) in (1 / (dirty_buckets_percent - 50)) second,
the second stage tries to writeback the amount of dirty data in one bucket
in (1 / (dirty_buckets_percent - 57)) * 100 millisecond, the third
stage tries to writeback the amount of dirty data in one bucket in
(1 / (dirty_buckets_percent - 64)) millisecond.

the initial rate at each stage can be controlled by 3 configurable
parameters writeback_rate_fp_term_{low|mid|high}, they are by default
1, 10, 1000, the hint of IO throughput that these values are trying
to achieve is described by above paragraph, the reason that
I choose those value as default is based on the testing and the
production data, below is some details:

A. When it comes to the low stage, there is still a bit far from the 70
   threshold, so we only want to give it a little bit push by setting the
   term to 1, it means the initial rate will be 170 if the fragment is 6,
   it is calculated by bucket_size/fragment, this rate is very small,
   but still much reasonable than the minimum 8.
   For a production bcache with unheavy workload, if the cache device
   is bigger than 1 TB, it may take hours to consume 1% buckets,
   so it is very possible to reclaim enough dirty buckets in this stage,
   thus to avoid entering the next stage.

B. If the dirty buckets ratio didn't turn around during the first stage,
   it comes to the mid stage, then it is necessary for mid stage
   to be more aggressive than low stage, so i choose the initial rate
   to be 10 times more than low stage, that means 1700 as the initial
   rate if the fragment is 6. This is some normal rate
   we usually see for a normal workload when writeback happens
   because of writeback_percent.

C. If the dirty buckets ratio didn't turn around during the low and mid
   stages, it comes to the third stage, and it is the last chance that
   we can turn around to avoid the horrible cutoff writeback sync issue,
   then we choose 100 times more aggressive than the mid stage, that
   means 170000 as the initial rate if the fragment is 6. This is also
   inferred from a production bcache, I've got one week's writeback rate
   data from a production bcache which has quite heavy workloads,
   again, the writeback is triggered by the writeback percent,
   the highest rate area is around 100000 to 240000, so I believe this
   kind aggressiveness at this stage is reasonable for production.
   And it should be mostly enough because the hint is trying to reclaim
   1000 bucket per second, and from that heavy production env,
   it is consuming 50 bucket per second on average in one week's data.

Option writeback_consider_fragment is to control whether we want
this feature to be on or off, it's on by default.

Lastly, below is the performance data for all the testing result,
including the data from production env:
https://docs.google.com/document/d/1AmbIEa_2MhB9bqhC3rfga9tp7n9YX9PLn0jSUxscVW0/edit?usp=sharing

Signed-off-by: dongdong tao 
Signed-off-by: Coly Li 
Signed-off-by: Jens Axboe

bcache: only check feature sets when sb->version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES

2021-01-28T14:35:07+00:00

For super block version < BCACHE_SB_VERSION_CDEV_WITH_FEATURES, it
doesn't make sense to check the feature sets. This patch checks
super block version in bch_has_feature_* routines, if the version
doesn't have feature sets yet, returns 0 (false) to the caller.

Fixes: 5342fd425502 ("bcache: set bcache device into read-only mode for BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET")
Fixes: ffa470327572 ("bcache: add bucket_size_hi into struct cache_sb_disk for large bucket")
Cc: stable@vger.kernel.org # 5.9+
Reported-and-tested-by: Bockholdt Arne 
Signed-off-by: Coly Li 
Signed-off-by: Jens Axboe