linux.git/block, branch v5.8-rc2

Merge tag 'block-5.8-2020-06-19' of git://git.kernel.dk/linux-block

2020-06-19T20:11:26+00:00

Pull block fixes from Jens Axboe:

 - Use import_uuid() where appropriate (Andy)

 - bcache fixes (Coly, Mauricio, Zhiqiang)

 - blktrace sparse warnings fix (Jan)

 - blktrace concurrent setup fix (Luis)

 - blkdev_get use-after-free fix (Jason)

 - Ensure all blk-mq maps are updated (Weiping)

 - Loop invalidate bdev fix (Zheng)

* tag 'block-5.8-2020-06-19' of git://git.kernel.dk/linux-block:
  block: make function 'kill_bdev' static
  loop: replace kill_bdev with invalidate_bdev
  partitions/ldm: Replace uuid_copy() with import_uuid() where it makes sense
  block: update hctx map when use multiple maps
  blktrace: Avoid sparse warnings when assigning q->blk_trace
  blktrace: break out of blktrace setup on concurrent calls
  block: Fix use-after-free in blkdev_get()
  trace/events/block.h: drop kernel-doc for dropped function parameter
  blk-mq: Remove redundant 'return' statement
  bcache: pr_info() format clean up in bcache_device_init()
  bcache: use delayed kworker fo asynchronous devices registration
  bcache: check and adjust logical block size for backing devices
  bcache: fix potential deadlock problem in btree_gc_coalesce

partitions/ldm: Replace uuid_copy() with import_uuid() where it makes sense

2020-06-18T15:17:54+00:00

There is a specific API to treat raw data as UUID, i.e. import_uuid().
Use it instead of uuid_copy() with explicit casting.

Signed-off-by: Andy Shevchenko 
Signed-off-by: Jens Axboe

block: update hctx map when use multiple maps

2020-06-18T03:33:04+00:00

There is an issue when tune the number for read and write queues,
if the total queue count was not changed. The hctx->type cannot
be updated, since __blk_mq_update_nr_hw_queues will return directly
if the total queue count has not been changed.

Reproduce:

dmesg | grep "default/read/poll"
[    2.607459] nvme nvme0: 48/0/0 default/read/poll queues
cat /sys/kernel/debug/block/nvme0n1/hctx*/type | sort | uniq -c
     48 default

tune the write queues to 24:
echo 24 > /sys/module/nvme/parameters/write_queues
echo 1 > /sys/block/nvme0n1/device/reset_controller

dmesg | grep "default/read/poll"
[  433.547235] nvme nvme0: 24/24/0 default/read/poll queues

cat /sys/kernel/debug/block/nvme0n1/hctx*/type | sort | uniq -c
     48 default

The driver's hardware queue mapping is not same as block layer.

Signed-off-by: Weiping Zhang 
Reviewed-by: Ming Lei 
Signed-off-by: Jens Axboe

block: Replace zero-length array with flexible-array

2020-06-16T04:08:32+00:00

There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://github.com/KSPP/linux/issues/21

Signed-off-by: Gustavo A. R. Silva

blk-mq: Remove redundant 'return' statement

2020-06-15T14:34:43+00:00

The blk_mq_all_tag_iter() is a void function, thus remove
the redundant 'return' statement in this function.

Signed-off-by: Baolin Wang 
Reviewed-by: Ming Lei 
Signed-off-by: Jens Axboe

Merge tag 'kbuild-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2020-06-13T20:29:16+00:00

Pull more Kbuild updates from Masahiro Yamada:

 - fix build rules in binderfs sample

 - fix build errors when Kbuild recurses to the top Makefile

 - covert '---help---' in Kconfig to 'help'

* tag 'kbuild-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  treewide: replace '---help---' in Kconfig files with 'help'
  kbuild: fix broken builds because of GZIP,BZIP2,LZOP variables
  samples: binderfs: really compile this sample and fix build issues

treewide: replace '---help---' in Kconfig files with 'help'

2020-06-13T16:57:21+00:00

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada

blk-mq: fix blk_mq_all_tag_iter

2020-06-07T14:56:50+00:00

blk_mq_all_tag_iter() is added to iterate all requests, so we should
fetch the request from ->static_rqs][] instead of ->rqs[] which is for
holding in-flight request only.

Fix it by adding flag of BT_TAG_ITER_STATIC_RQS.

Fixes: bf0beec0607d ("blk-mq: drain I/O when all CPUs in a hctx are offline")
Signed-off-by: Ming Lei 
Tested-by: John Garry 
Cc: Dongli Zhang 
Cc: Hannes Reinecke 
Cc: Daniel Wagner 
Cc: Christoph Hellwig 
Signed-off-by: Jens Axboe

blk-mq: split out a __blk_mq_get_driver_tag helper

2020-06-07T14:56:50+00:00

Allocation of the driver tag in the case of using a scheduler shares very
little code with the "normal" tag allocation.  Split out a new helper to
streamline this path, and untangle it from the complex normal tag
allocation.

This way also avoids to fail driver tag allocation because of inactive hctx
during cpu hotplug, and fixes potential hang risk.

Fixes: bf0beec0607d ("blk-mq: drain I/O when all CPUs in a hctx are offline")
Signed-off-by: Ming Lei 
Signed-off-by: Christoph Hellwig 
Tested-by: John Garry 
Cc: Dongli Zhang 
Cc: Hannes Reinecke 
Cc: Daniel Wagner 
Signed-off-by: Jens Axboe

block: nr_sects_write(): Disable preemption on seqcount write

2020-06-05T03:22:28+00:00

For optimized block readers not holding a mutex, the "number of sectors"
64-bit value is protected from tearing on 32-bit architectures by a
sequence counter.

Disable preemption before entering that sequence counter's write side
critical section. Otherwise, the read side can preempt the write side
section and spin for the entire scheduler tick. If the reader belongs to
a real-time scheduling class, it can spin forever and the kernel will
livelock.

Fixes: c83f6bf98dc1 ("block: add partition resize function to blkpg ioctl")
Cc: 
Signed-off-by: Ahmed S. Darwish 
Reviewed-by: Sebastian Andrzej Siewior 
Signed-off-by: Jens Axboe