Pull NVMe fixes from Christoph:

"nvme fixes for Linux 6.2

 - fix  controller shutdown regression in nvme-apple (Janne Grunau)
 - fix a polling on timeout regression in nvme-pci (Keith Busch)"

* tag 'nvme-6.2-2023-01-20' of git://git.infradead.org/nvme:
  nvme-pci: fix timeout request state check
  nvme-apple: only reset the controller when RTKit is running
  nvme-apple: reset controller during shutdown

Polling the completion can progress the request state to IDLE, either
inline with the completion, or through softirq. Either way, the state
may not be COMPLETED, so don't check for that. We only care if the state
isn't IN_FLIGHT.

This is fixing an issue where the driver aborts an IO that we just
completed. Seeing the "aborting" message instead of "polled" is very
misleading as to where the timeout problem resides.

Fixes: bf392a5d ("nvme-pci: Remove tag from process cq")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

NVMe controller register access hangs indefinitely when the co-processor
is not running. A missed reset is preferable over a hanging thread since
it could be recoverable.
Signed-off-by: Janne Grunau <j@jannau.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>

This is a functional revert of c76b8308 ("nvme-apple: fix controller
shutdown in apple_nvme_disable").

The commit broke suspend/resume since apple_nvme_reset_work() tries to
disable the controller on resume. This does not work for the apple NVMe
controller since register access only works while the co-processor
firmware is running.

Disabling the NVMe controller in the shutdown path is also required
for shutting the co-processor down. The original code was appropriate
for this hardware. Add a comment to prevent a similar breaking changes
in the future.

Fixes: c76b8308 ("nvme-apple: fix controller shutdown in apple_nvme_disable")
Reported-by: Janne Grunau <j@jannau.net>
Link: https://lore.kernel.org/all/20230110174745.GA3576@jannau.net/Signed-off-by: Janne Grunau <j@jannau.net>
[hch: updated with a more descriptive comment from Hector Martin]
Signed-off-by: Christoph Hellwig <hch@lst.de>

When there are no read queues read requests will be assigned a
default queue on allocation. However, blk_mq_get_cached_request() is not
prepared for that and will fail all attempts to grab read requests from
the cache. Worst case it doubles the number of requests allocated,
roughly half of which will be returned by blk_mq_free_plug_rqs().

It only affects batched allocations and so is io_uring specific.
For reference, QD8 t/io_uring benchmark improves by 20-35%.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/80d4511011d7d4751b4cf6375c4e38f237d935e3.1673955390.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

We need to pass 'end - 1' to ida_alloc_max after switch from
ida_simple_get to ida_alloc_max.

Otherwise smatch warns.

drivers/block/rnbd/rnbd-clt.c:1460 init_dev() error: Calling ida_alloc_max() with a 'max' argument which is a power of 2. -1 missing?

Fixes: 24afc15d ("block/rnbd: Remove a useless mutex")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20221230010926.32243-1-guoqing.jiang@linux.devSigned-off-by: Jens Axboe <axboe@kernel.dk>

If the policy defines pd_online_fn(), it should be called after
pd_init_fn(), like blkg_create().
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230103112833.2013432-1-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

The revert of the removal of this driver happened after we fixed up
the split limits for NOWAIT issue, hence it got missed. Ensure that
we check for a NULL bio after splitting, in case it should be retried.

Marking this as fixing both commits, so that stable backport will do
this correctly.

Cc: stable@vger.kernel.org
Fixes: 9cea62b2 ("block: don't allow splitting of a REQ_NOWAIT bio")
Fixes: 4b83e99e ("Revert "pktcdvd: remove driver."")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The updating of 'bfqg->ref' should be protected by 'bfqd->lock', however,
during code review, we found that bfq_pd_free() update 'bfqg->ref'
without holding the lock, which is problematic:

1) bfq_pd_free() triggered by removing cgroup is called asynchronously;
2) bfqq will grab bfqg reference, and exit bfqq will drop the reference,
which can concurrent with 1).

Unfortunately, 'bfqd->lock' can't be held here because 'bfqd' might already
be freed in bfq_pd_free(). Fix the problem by using atomic refcount apis.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230103084755.1256479-1-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pull MD fix from Song:

"It fixes an issue introduced by recent code refactor."

* 'md-fixes' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  md: fix incorrect declaration about claim_rdev in md_import_device

Commit fb541ca4 ("md: remove lock_bdev / unlock_bdev") removes
wrappers for blkdev_get/blkdev_put. However, the uninitialized local
static variable of pointer type 'claim_rdev' in md_import_device()
is NULL, which leads to the following warning call trace:

  WARNING: CPU: 22 PID: 1037 at block/bdev.c:577 bd_prepare_to_claim+0x131/0x150
  CPU: 22 PID: 1037 Comm: mdadm Not tainted 6.2.0-rc3+ #69
  ..
  RIP: 0010:bd_prepare_to_claim+0x131/0x150
  ..
  Call Trace:
   <TASK>
   ? _raw_spin_unlock+0x15/0x30
   ? iput+0x6a/0x220
   blkdev_get_by_dev.part.0+0x4b/0x300
   md_import_device+0x126/0x1d0
   new_dev_store+0x184/0x240
   md_attr_store+0x80/0xf0
   kernfs_fop_write_iter+0x128/0x1c0
   vfs_write+0x2be/0x3c0
   ksys_write+0x5f/0xe0
   do_syscall_64+0x38/0x90
   entry_SYSCALL_64_after_hwframe+0x72/0xdc

It turns out the md device cannot be used:

  md: could not open device unknown-block(259,0).
  md: md127 stopped.

Fix the issue by declaring the local static variable of struct type
and passing the pointer of the variable to blkdev_get_by_dev().

Fixes: fb541ca4 ("md: remove lock_bdev / unlock_bdev")
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Adrian Huang <ahuang12@lenovo.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>

Pull NVMe fixes from Christoph:

"nvme fixes for Linux 6.2

 - Identify quirks for Apple controllers (Hector Martin)
 - fix error handling in nvme_pci_enable (Tong Zhang)
 - refuse unprivileged passthrough on partitions (Christoph Hellwig)
 - fix MAINTAINERS to not match nvmem subsystem headers (Russell King)"

* tag 'nvme-6.2-2023-01-12' of git://git.infradead.org/nvme:
  MAINTAINERS: stop nvme matching for nvmem files
  nvme: don't allow unprivileged passthrough on partitions
  nvme: replace the "bool vec" arguments with flags in the ioctl path
  nvme: remove __nvme_ioctl
  nvme-pci: fix error handling in nvme_pci_enable()
  nvme-pci: add NVME_QUIRK_IDENTIFY_CNS quirk to Apple T2 controllers
  nvme-apple: add NVME_QUIRK_IDENTIFY_CNS quirk to fix regression

The nvme patterns detect all include files starting with nvme, which
also picks up the nvmem subsystem header files. Fix this by using
a more specific pattern.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
[hch: switched to a purely inclusive pattern instead of excluding nvmem*]
Signed-off-by: Christoph Hellwig <hch@lst.de>

Passthrough commands can always access the entire device, and thus
submitting them on partitions is an privelege escalation.

In hindsight we should have never allowed any passthrough commands on
partitions, but it's probably too late to change that decision now.

Fixes: e4fbcf32 ("nvme: identify-namespace without CAP_SYS_ADMIN")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

To prepare for passing down more information, replace the boolean
vec argument with a more extensible flags one.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

Open code __nvme_ioctl in the two callers to make future changes that
pass down additional paramters in the ioctl path easier.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

There are two issues in nvme_pci_enable():

 1) If pci_alloc_irq_vectors() fails, device is left enabled. Fix this by
    adding a goto disable statement.
 2) nvme_pci_configure_admin_queue could return -ENODEV, in this case,
    we will need to free IRQ properly.  Otherwise the following warning
    could be triggered:

[    5.286752] WARNING: CPU: 0 PID: 33 at kernel/irq/irqdomain.c:253 irq_domain_remove+0x12d/0x140
[    5.290547] Call Trace:
[    5.290626]  <TASK>
[    5.290695]  msi_remove_device_irq_domain+0xc9/0xf0
[    5.290843]  msi_device_data_release+0x15/0x80
[    5.290978]  release_nodes+0x58/0x90
[    5.293788] WARNING: CPU: 0 PID: 33 at kernel/irq/msi.c:276 msi_device_data_release+0x76/0x80
[    5.297573] Call Trace:
[    5.297651]  <TASK>
[    5.297719]  release_nodes+0x58/0x90
[    5.297831]  devres_release_all+0xef/0x140
[    5.298339]  device_unbind_cleanup+0x11/0xc0
[    5.298479]  really_probe+0x296/0x320

Fixes: a6ee7f19 ("nvme-pci: call nvme_pci_configure_admin_queue from nvme_pci_enable")
Co-developed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Tong Zhang <ztong0001@gmail.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

This mirrors the quirk added to Apple Silicon controllers in apple.c.
These controllers do not support the Active NS ID List command and
behave identically to the SoC version judging by existing user
reports/syslogs, so will need the same fix. This quirk reverts
back to NVMe 1.0 behavior and disables the broken commands.

Fixes: 811f4de0 ("nvme: avoid fallback to sequential scan due to transient issues")
Signed-off-by: Hector Martin <marcan@marcan.st>
Tested-by: Orlando Chamberlain <orlandoch.dev@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

From the get-go, this driver and the ANS syslog have been complaining
about namespace identification. In 6.2-rc1, commit 811f4de0 ("nvme:
avoid fallback to sequential scan due to transient issues") regressed
the driver by no longer allowing fallback to sequential namespace scans,
leaving us with no namespaces.

It turns out that the real problem is that this controller claiming
NVMe 1.1 compat is treating the CNS field as a binary field, as in NVMe
1.0. This already has a quirk, NVME_QUIRK_IDENTIFY_CNS, so set it for
the controller to fix all this nonsense (including other errors
triggered by other CNS commands).

Fixes: 811f4de0 ("nvme: avoid fallback to sequential scan due to transient issues")
Fixes: 5bd2927a ("nvme-apple: Add initial Apple SoC NVMe driver")
Signed-off-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Dan reports the following smatch detected the following:

  block/blk-cgroup.c:1863 blkcg_schedule_throttle() warn: sleeping in atomic context

caused by blkcg_schedule_throttle() calling blk_put_queue() in an
non-sleepable context.

blk_put_queue() acquired might_sleep() in 63f93fd6 ("block: mark
blk_put_queue as potentially blocking") which transferred the might_sleep()
from blk_free_queue().

blk_free_queue() acquired might_sleep() in e8c7d14a ("block: revert back
to synchronous request_queue removal") while turning request_queue removal
synchronous. However, this isn't necessary as nothing in the free path
actually requires sleeping.

It's pretty unusual to require a sleeping context in a put operation and
it's not needed in the first place. Let's drop it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lkml.kernel.org/r/Y7g3L6fntnTtOm63@kili
Cc: Christoph Hellwig <hch@lst.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Fixes: e8c7d14a ("block: revert back to synchronous request_queue removal") # v5.9+
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/Y7iFwjN+XzWvLv3y@slm.duckdns.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Now that the SRCU Kconfig option is unconditionally selected, there is
no longer any point in selecting it.  Therefore, remove the "select SRCU"
Kconfig statements.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit f40eb998.

There are apparently still users out there of this driver. While we'd
love to remove it to ease the maintenance burden, let's reinstate it
for now until better (userspace) solutions can be developed.

Link: https://lore.kernel.org/lkml/20230104190115.ceglfefco475ev6c@pali/Reported-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit 85d6ce58.

We're reinstating the pktcdvd driver, which needs this API.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit db1c7d77.

We're reinstating the pktcdvd driver, which needs this API.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Most of control command handlers may sleep, so return -EAGAIN in case
of IO_URING_F_NONBLOCK to defer the handling into io wq context.

Fixes: 71f28f31 ("ublk_drv: add io_uring based userspace block driver")
Reported-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230104133235.836536-1-ming.lei@redhat.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

If we split a bio marked with REQ_NOWAIT, then we can trigger spurious
EAGAIN if constituent parts of that split bio end up failing request
allocations. Parts will complete just fine, but just a single failure
in one of the chained bios will yield an EAGAIN final result for the
parent bio.

Return EAGAIN early if we end up needing to split such a bio, which
allows for saner recovery handling.

Cc: stable@vger.kernel.org # 5.15+
Link: https://github.com/axboe/liburing/issues/766Reported-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This can't happen right now, but in preparation for allowing
bio_split_to_limits() returning NULL if it ended the bio, check for it
in all the callers.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull NVMe fixes from Christoph:

"nvme fixes for Linux 6.2

 - fix various problems in handling the Command Supported and Effects log
   (Christoph Hellwig)
 - don't allow unprivileged passthrough of commands that don't transfer
   data but modify logical block content (Christoph Hellwig)
 - add a features and quirks policy document (Christoph Hellwig)
 - fix some really nasty code that was correct but made smatch complain
   (Sagi Grimberg)"

* tag 'nvme-6.2-2022-12-29' of git://git.infradead.org/nvme:
  nvme-auth: fix smatch warning complaints
  nvme: consult the CSE log page for unprivileged passthrough
  nvme: also return I/O command effects from nvme_command_effects
  nvmet: don't defer passthrough commands with trivial effects to the workqueue
  nvmet: set the LBCC bit for commands that modify data
  nvmet: use NVME_CMD_EFFECTS_CSUPP instead of open coding it
  nvme: fix the NVME_CMD_EFFECTS_CSE_MASK definition
  docs, nvme: add a feature and quirk policy document

When initializing auth context, there may be no secrets passed
by the user. Make return code explicit when returning successfully.

smatch warnings:
drivers/nvme/host/auth.c:950 nvme_auth_init_ctrl() warn: missing error code? 'ret'
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Commands like Write Zeros can change the contents of a namespaces without
actually transferring data.  To protect against this, check the Commands
Supported and Effects log is supported by the controller for any
unprivileg command passthrough and refuse unprivileged passthrough if the
command has any effects that can change data or metadata.

Note: While the Commands Support and Effects log page has only been
mandatory since NVMe 2.0, it is widely supported because Windows requires
it for any command passthrough from userspace.

Fixes: e4fbcf32 ("nvme: identify-namespace without CAP_SYS_ADMIN")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>

To be able to use the Commands Supported and Effects Log for allowing
unprivileged passtrough, it needs to be corretly reported for I/O
commands as well.  Return the I/O command effects from
nvme_command_effects, and also add a default list of effects for the
NVM command set.  For other command sets, the Commands Supported and
Effects log is required to be present already.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>

Mask out the "Command Supported" and "Logical Block Content Change" bits
and only defer execution of commands that have non-trivial effects to
the workqueue for synchronous execution.  This allows to execute admin
commands asynchronously on controllers that provide a Command Supported
and Effects log page, and will keep allowing to execute Write commands
asynchronously once command effects on I/O commands are taken into
account.

Fixes: c1fef73f ("nvmet: add passthru code to process commands")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>

Write, Write Zeroes, Zone append and a Zone Reset through
Zone Management Send modify the logical block content of a namespace,
so make sure the LBCC bit is reported for them.

Fixes: b5d0b38c0475 ("nvmet: add Command Set Identifier support")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

Use NVME_CMD_EFFECTS_CSUPP instead of open coding it and assign a
single value to multiple array entries instead of repeated assignments.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

3 << 16 does not generate the correct mask for bits 16, 17 and 18.
Use the GENMASK macro to generate the correct mask instead.

Fixes: 84fef62d ("nvme: check admin passthru command effects")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>

This adds a document about what specification features are supported by
the Linux NVMe driver, and what qualifies for a quirk if an implementation
has problems following the specification.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>

Update the core sqsize field in addition to the PCIe-specific
q_depth field as the core tagset allocation helpers rely on it.

Fixes: 0da7feaa ("nvme-pci: use the tagset alloc/free helpers")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Hugh Dickins <hughd@google.com>
Link: https://lore.kernel.org/r/20221225103234.226794-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

While the CAP.MQES field in NVMe is a 0s based filed with a natural one
off, we also need to account for the queue wrap condition and fix undo
the one off again in nvme_alloc_io_tag_set.  This was never properly
done by the fabrics drivers, but they don't seem to care because there
is no actual physical queue that can wrap around, but it became a
problem when converting over the PCIe driver.  Also add back the
BLK_MQ_MAX_DEPTH check that was lost in the same commit.

Fixes: 0da7feaa ("nvme-pci: use the tagset alloc/free helpers")
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Hugh Dickins <hughd@google.com>
Link: https://lore.kernel.org/r/20221225103234.226794-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Commit 64dc8c73 ("block, bfq: fix possible uaf for 'bfqq->bic'")
will access 'bic->bfqq' in bic_set_bfqq(), however, bfq_exit_icq_bfqq()
can free bfqq first, and then call bic_set_bfqq(), which will cause uaf.

Fix the problem by moving bfq_exit_bfqq() behind bic_set_bfqq().

Fixes: 64dc8c73 ("block, bfq: fix possible uaf for 'bfqq->bic'")
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20221226030605.1437081-1-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pull NVMe fixes from Christoph:

"nvme fixes for Linux 6.2

 - fix doorbell buffer value endianness (Klaus Jensen)
 - fix Linux vs NVMe page size mismatch (Keith Busch)
 - fix a potential use memory access beyong the allocation limit
   (Keith Busch)
 - fix a multipath vs blktrace NULL pointer dereference
   (Yanjun Zhang)"

* tag 'nvme-6.2-2022-12-22' of git://git.infradead.org/nvme:
  nvme: fix multipath crash caused by flush request when blktrace is enabled
  nvme-pci: fix page size checks
  nvme-pci: fix mempool alloc size
  nvme-pci: fix doorbell buffer value endianness