Make nvme_ns_remove match the assumptions elsewhere.

1) !NVME_NS_READY needs to be srcu synchronized to make sure nothing is
   running in __nvme_find_path or nvme_round_robin_path that will
   re-assign this ns to current_path.

2) Any matching current_path entries need to be cleared before removing
   from the siblings list, to prevent calling nvme_round_robin_path with
   an "old" ns that's off list.

3) Finally the list_del_rcu can happen, and then synchronize again
   before releasing any reference counts.
Signed-off-by: Christoph Hellwig <hch@lst.de>

A NVMe subsystem with multiple controller can have private namespaces
that use the same NSID under some conditions:

 "If Namespace Management, ANA Reporting, or NVM Sets are supported, the
  NSIDs shall be unique within the NVM subsystem. If the Namespace
  Management, ANA Reporting, and NVM Sets are not supported, then NSIDs:
   a) for shared namespace shall be unique; and
   b) for private namespace are not required to be unique."

Reference: Section 6.1.6 NSID and Namespace Usage; NVM Express 1.4c spec.

Make sure this specific setup is supported in Linux.

Fixes: 9ad1927a ("nvme: always search for namespace head")
Signed-off-by: Sungup Moon <sungup.moon@samsung.com>
[hch: refactored and fixed the controller vs subsystem based naming
      conflict]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

The left shift is followed by a re-assignment back to cc_css, the
assignment is redundant.  Fix this by replacing the "<<=" operator with
"<<" instead.

This cleans up the clang scan build warning:

drivers/nvme/target/core.c:1124:10: warning: Although the value stored to 'cc_css' is used in the enclosing expression, the value is never actually read from 'cc_css' [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Any attempt to flush kernel-global WQs has possibility of deadlock
so we should simply stop using them, instead introduce nvmet_wq
which is the generic nvmet workqueue for work elements that
don't explicitly require a dedicated workqueue (by the mere fact
that they are using the system_wq).

Changes were done using the following replaces:

 - s/schedule_work(/queue_work(nvmet_wq, /g
 - s/schedule_delayed_work(/queue_delayed_work(nvmet_wq, /g
 - s/flush_scheduled_work()/flush_workqueue(nvmet_wq)/g
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Add quirks to not fail the initialization and to have quick resume
latency after cold/warm reboot.
Signed-off-by: Monish Kumar R <monish.kumar.r@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Allow reading /sys/module/nvme/parameters/use_threaded_interrupts to see
if the use_threaded_interrupts module parameter is in use.
Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

commit 2f4c9ba2 ("nvme: export zoned namespaces without Zone Append
support read-only") marks zoned namespaces without append support
read-only.  It does iso by setting NVME_NS_FORCE_RO in ns->flags in
nvme_update_zone_info and checking for that flag later in
nvme_update_disk_info to mark the disk as read-only.

But commit 73d90386 ("nvme: cleanup zone information initialization")
rearranged nvme_update_disk_info to be called before
nvme_update_zone_info and thus not marking the disk as read-only.
The call order cannot be just reverted because nvme_update_zone_info sets
certain queue parameters such as zone_write_granularity that depend on the
prior call to nvme_update_disk_info.

Remove the call to set_disk_ro in nvme_update_disk_info. and call
set_disk_ro after nvme_update_zone_info and nvme_update_disk_info to set
the permission for ZNS drives correctly. The same applies to the
multipath disk path.

Fixes: 73d90386 ("nvme: cleanup zone information initialization")
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

My kernel robot report below:

  drivers/block/n64cart.c: In function ‘n64cart_submit_bio’:
  drivers/block/n64cart.c:91:26: error: ‘struct bio’ has no member named ‘bi_disk’
     91 |  struct device *dev = bio->bi_disk->private_data;
        |                          ^~
    CC      drivers/slimbus/qcom-ctrl.o
    CC      drivers/auxdisplay/hd44780.o
    CC      drivers/watchdog/watchdog_core.o
    CC      drivers/nvme/host/fault_inject.o
    AR      drivers/accessibility/braille/built-in.a
  make[2]: *** [scripts/Makefile.build:288: drivers/block/n64cart.o] Error 1

Fixes: 309dca30 ("block: store a block_device pointer in struct bio");
Reported-by: k2ci <kernel-bot@kylinos.cn>
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220321071216.1549596-1-liu.yun@linux.devSigned-off-by: Jens Axboe <axboe@kernel.dk>

The 'need_copy' is set when rq_data_dir(req) returns WRITE, in order to
copy the written data to persistent page.

".need_copy = rq_data_dir(req) && info->feature_persistent,"
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Fixes: c004a6fe ('block/xen-blkfront: Make it running on 64KB page granularity')
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220317220930.5698-1-dongli.zhang@oracle.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Variable i is being assigned a value that is never read, it is being
re-assigned later in a for-loop. The assignment is redundant and can
be removed.

Cleans up clang scan build warning:
drivers/block/xen-blkback/blkback.c:934:14: warning: Although the value
stored to 'i' is used in the enclosing expression, the value is never
actually read from 'i' [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220317234646.78158-1-colin.i.king@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pull NVMe updates from Christoph:

"Second round of nvme updates for Linux 5.18

 - add lockdep annotations for in-kernel sockets (Chris Leech)
 - use vmalloc for ANA log buffer (Hannes Reinecke)
 - kerneldoc fixes (Chaitanya Kulkarni)
 - cleanups (Guoqing Jiang, Chaitanya Kulkarni, me)
 - warn about shared namespaces without multipathing (me)"

* tag 'nvme-5.18-2022-03-17' of git://git.infradead.org/nvme:
  nvme: warn about shared namespaces without CONFIG_NVME_MULTIPATH
  nvme: remove nvme_alloc_request and nvme_alloc_request_qid
  nvme: cleanup how disk->disk_name is assigned
  nvmet: move the call to nvmet_ns_changed out of nvmet_ns_revalidate
  nvmet: use snprintf() with PAGE_SIZE in configfs
  nvmet: don't fold lines
  nvmet-rdma: fix kernel-doc warning for nvmet_rdma_device_removal
  nvmet-fc: fix kernel-doc warning for nvmet_fc_unregister_targetport
  nvmet-fc: fix kernel-doc warning for nvmet_fc_register_targetport
  nvme-tcp: lockdep: annotate in-kernel sockets
  nvme-tcp: don't fold the line
  nvme-tcp: don't initialize ret variable
  nvme-multipath: call bio_io_error in nvme_ns_head_submit_bio
  nvme-multipath: use vmalloc for ANA log buffer

Eliminate anonymous module_init() and module_exit(), which can lead to
confusion or ambiguity when reading System.map, crashes/oops/bugs,
or an initcall_debug log.

Give each of these init and exit functions unique driver-specific
names to eliminate the anonymous names.

Example 1: (System.map)
 ffffffff832fc78c t init
 ffffffff832fc79e t init
 ffffffff832fc8f8 t init

Example 2: (initcall_debug log)
 calling  init+0x0/0x12 @ 1
 initcall init+0x0/0x12 returned 0 after 15 usecs
 calling  init+0x0/0x60 @ 1
 initcall init+0x0/0x60 returned 0 after 2 usecs
 calling  init+0x0/0x9a @ 1
 initcall init+0x0/0x9a returned 0 after 74 usecs

Fixes: e467cde2 ("Block driver using virtio.")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20220316192010.19001-2-rdunlap@infradead.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Start warning about exposing a namespace as multiple block devices,
and set a fixed deprecation release.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>

Just open code the allocation + initialization in the callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

They way how assigning the disk name and commenting on why it is done
is split over core.c and multipath.c seems to be rather confusing.

Now that ns_head->disk always exists we can do all the work in core.c
and have a single big comment explaining the issues.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

nvmet_ns_changed states via lockdep that the ns->subsys->lock must be
held. The only caller of nvmet_ns_changed which does not acquire that
lock is nvmet_ns_revalidate. nvmet_ns_revalidate has 3 callers,
of which 2 do not acquire that lock: nvmet_execute_identify_cns_cs_ns
and nvmet_execute_identify_ns. The other caller
nvmet_ns_revalidate_size_store does acquire the lock.

Move the call to nvmet_ns_changed from nvmet_ns_revalidate to the callers
so that they can perform the correct locking as needed.

This issue was found using a static type-based analyser and manually
verified.
Reported-by: Niels Dossche <dossche.niels@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

Instead of using sprintf, use snprintf with buffer size limited to
PAGE_SIZE just like what we have for the rest of the file.
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Don't fold line that can fit into 80 char limit. No functional change
in this patch.
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

This fixes following kernel-doc warning:-

drivers/nvme/target/rdma.c:1722: warning: expecting prototype for nvme_rdma_device_removal(). Prototype was for nvmet_rdma_device_removal() instead
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

This fixes following kernel-doc warning:-

drivers/nvme/target/fc.c:1619: warning: expecting prototype for nvme_fc_unregister_targetport(). Prototype was for nvmet_fc_unregister_targetport() instead
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

This fixes following kernel-doc warning :-

drivers/nvme/target/fc.c:1365: warning: expecting prototype for nvme_fc_register_targetport(). Prototype was for nvmet_fc_register_targetport() instead
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Put NVMe/TCP sockets in their own class to avoid some lockdep warnings.
Sockets created by nvme-tcp are not exposed to user-space, and will not
trigger certain code paths that the general socket API exposes.

Lockdep complains about a circular dependency between the socket and
filesystem locks, because setsockopt can trigger a page fault with a
socket lock held, but nvme-tcp sends requests on the socket while file
system locks are held.

  ======================================================
  WARNING: possible circular locking dependency detected
  5.15.0-rc3 #1 Not tainted
  ------------------------------------------------------
  fio/1496 is trying to acquire lock:
  (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendpage+0x23/0x80

  but task is already holding lock:
  (&xfs_dir_ilock_class/5){+.+.}-{3:3}, at: xfs_ilock+0xcf/0x290 [xfs]

  which lock already depends on the new lock.

  other info that might help us debug this:

  chain exists of:
   sk_lock-AF_INET --> sb_internal --> &xfs_dir_ilock_class/5

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&xfs_dir_ilock_class/5);
                                lock(sb_internal);
                                lock(&xfs_dir_ilock_class/5);
   lock(sk_lock-AF_INET);

  *** DEADLOCK ***

  6 locks held by fio/1496:
   #0: (sb_writers#13){.+.+}-{0:0}, at: path_openat+0x9fc/0xa20
   #1: (&inode->i_sb->s_type->i_mutex_dir_key){++++}-{3:3}, at: path_openat+0x296/0xa20
   #2: (sb_internal){.+.+}-{0:0}, at: xfs_trans_alloc_icreate+0x41/0xd0 [xfs]
   #3: (&xfs_dir_ilock_class/5){+.+.}-{3:3}, at: xfs_ilock+0xcf/0x290 [xfs]
   #4: (hctx->srcu){....}-{0:0}, at: hctx_lock+0x51/0xd0
   #5: (&queue->send_mutex){+.+.}-{3:3}, at: nvme_tcp_queue_rq+0x33e/0x380 [nvme_tcp]

This annotation lets lockdep analyze nvme-tcp controlled sockets
independently of what the user-space sockets API does.

Link: https://lore.kernel.org/linux-nvme/CAHj4cs9MDYLJ+q+2_GXUK9HxFizv2pxUryUR0toX974M040z7g@mail.gmail.com/Signed-off-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

The call to nvme_tcp_alloc_queue() fits perfectly in one line without
exceeding 80 char limit for the line.
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

No point in initializing ret variable to 0 in nvme_tcp_start_io_queue()
since it gets overwritten by a call to nvme_tcp_start_queue().
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Use bio_io_error() here since bio_io_error does the same thing.
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

The ANA log buffer can get really large, as it depends on the
controller configuration. So to avoid an out-of-memory issue
during scanning use kvmalloc() instead of the kmalloc().
Signed-off-by: Hannes Reinecke <hare@suse.de>
Tested-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

purge_persistent_grants() is scanning the grants list for persistent
grants being no longer in use by the backend. When having found such a
grant, it will be set to "invalid" and pushed to the tail of the list.

Instead of pushing it directly to the end of the list, add it first to
a temporary list, avoiding to scan those entries again in the main
list traversal. After having finished the scan, append the temporary
list to the grant list.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Link: https://lore.kernel.org/r/20220311103527.12931-1-jgross@suse.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Merge branch 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into for-5.18/drivers

Pull MD updates from Song:

"This set contains raid5 bio handling cleanups for raid5."

* 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  raid5: initialize the stripe_head embeeded bios as needed
  raid5-cache: statically allocate the recovery ra bio
  raid5-cache: fully initialize flush_bio when needed
  raid5-ppl: fully initialize the bio in ppl_new_iounit

Use bio_init to initialize the bios when needed to the full state
instead of a partial initialization plus later setting of dev and op
and bio_reset.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>

There is no need to preallocate the bio and reset it when use.  Just
allocate it on-stack and use a bvec places next to the pages used for
it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>

Stop using bio_reset and just initialize the bio fully when needed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>

We have all the information to pass the bdev and op directly to bio_init,
so do that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>

Merge branch 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into for-5.18/drivers

Pull MD fixes from Song:

"Most of these changes are minor fixes and clean-ups."

* 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  md: use msleep() in md_notify_reboot()
  lib/raid6: Include <asm/ppc-opcode.h> for VPERMXOR
  lib/raid6/test/Makefile: Use $(pound) instead of \# for Make 4.3
  lib/raid6/test: fix multiple definition linking error
  md: raid1/raid10: drop pending_cnt

Calling mdelay(1000) from process context, even while a reboot
is in progress, does not make sense.

Using msleep() allows other threads to make progress.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: linux-raid@vger.kernel.org
Signed-off-by: Song Liu <song@kernel.org>

On Ubuntu 21.10 (ppc64le) building raid6test with gcc (Ubuntu
11.2.0-7ubuntu2) 11.2.0 fails with the error below.

    gcc -I.. -I ../../../include -g -O2                       \
             -I../../../arch/powerpc/include -DCONFIG_ALTIVEC \
             -c -o vpermxor1.o vpermxor1.c
    vpermxor1.c: In function ‘raid6_vpermxor1_gen_syndrome_real’:
    vpermxor1.c:64:29: error: expected string literal before ‘VPERMXOR’
       64 |   asm(VPERMXOR(%0,%1,%2,%3):"=v"(wq0):"v"(gf_high), "v"(gf_low), "v"(wq0));
          |       ^~~~~~~~
    make: *** [Makefile:58: vpermxor1.o] Error 1

So, include the header asm/ppc-opcode.h defining this macro also when
not building the Linux kernel but only this too.

Cc: Matt Brown <matthew.brown.dev@gmail.com>
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Song Liu <song@kernel.org>

Buidling raid6test on Ubuntu 21.10 (ppc64le) with GNU Make 4.3 shows the
errors below:

    $ cd lib/raid6/test/
    $ make
    <stdin>:1:1: error: stray ‘\’ in program
    <stdin>:1:2: error: stray ‘#’ in program
    <stdin>:1:11: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ \
        before ‘<’ token

    [...]

The errors come from the HAS_ALTIVEC test, which fails, and the POWER
optimized versions are not built. That’s also reason nobody noticed on the
other architectures.

GNU Make 4.3 does not remove the backslash anymore. From the 4.3 release
announcment:

> * WARNING: Backward-incompatibility!
>   Number signs (#) appearing inside a macro reference or function invocation
>   no longer introduce comments and should not be escaped with backslashes:
>   thus a call such as:
>     foo := $(shell echo '#')
>   is legal.  Previously the number sign needed to be escaped, for example:
>     foo := $(shell echo '\#')
>   Now this latter will resolve to "\#".  If you want to write makefiles
>   portable to both versions, assign the number sign to a variable:
>     H := \#
>     foo := $(shell echo '$H')
>   This was claimed to be fixed in 3.81, but wasn't, for some reason.
>   To detect this change search for 'nocomment' in the .FEATURES variable.

So, do the same as commit 9564a8cf ("Kbuild: fix # escaping in .cmd
files for future Make") and commit 929bef46 ("bpf: Use $(pound) instead
of \# in Makefiles") and define and use a $(pound) variable.

Reference for the change in make:
https://git.savannah.gnu.org/cgit/make.git/commit/?id=c6966b323811c37acedff05b57

Cc: Matt Brown <matthew.brown.dev@gmail.com>
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Song Liu <song@kernel.org>

GCC 10+ defaults to -fno-common, which enforces proper declaration of
external references using "extern". without this change a link would
fail with:

  lib/raid6/test/algos.c:28: multiple definition of `raid6_call';
  lib/raid6/test/test.c:22: first defined here

the pq.h header that is included already includes an extern declaration
so we can just remove the redundant one here.

Cc: <stable@vger.kernel.org>
Signed-off-by: Dirk Müller <dmueller@suse.de>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Song Liu <song@kernel.org>

Those counters are not necessary after commit 11bb45e8aaf6 ("md: drop queue
limitation for RAID1 and RAID10"). Remove them from all code (conf and
plug structs). raid1_plug_cb and raid10_plug_cb are identical, so move
definition of raid1_plug_cb to common raid1-10 definitions and use it for
RAID10 too.
Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Signed-off-by: Song Liu <song@kernel.org>

Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/colyli/linux-bcache into for-5.18/drivers

Pull bcache updates from Coly:

"We have 2 patches for Linux v5.18, both of them are from Mingzhe Zou.
 The first patch improves bcache initialization speed by avoid
 unnecessary cost of cache consistency, the second one fixes a potential
 NULL pointer deference in bcache initialization time."

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/colyli/linux-bcache:
  bcache: fixup multiple threads crash
  bcache: fixup bcache_dev_sectors_dirty_add() multithreaded CPU false sharing

When multiple threads to check btree nodes in parallel, the main
thread wait for all threads to stop or CACHE_SET_IO_DISABLE flag:

wait_event_interruptible(check_state->wait,
                         atomic_read(&check_state->started) == 0 ||
                         test_bit(CACHE_SET_IO_DISABLE, &c->flags));

However, the bch_btree_node_read and bch_btree_node_read_done
maybe call bch_cache_set_error, then the CACHE_SET_IO_DISABLE
will be set. If the flag already set, the main thread return
error. At the same time, maybe some threads still running and
read NULL pointer, the kernel will crash.

This patch change the event wait condition, the main thread must
wait for all threads to stop.

Fixes: 8e710227 ("bcache: make bch_btree_check() to be multithreaded")
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Coly Li <colyli@suse.de>