It's silly to use blk_mq_free_request() which in turn maps the
request to the hardware queue, for places where we already know
what the hardware queue is. This saves us an extra mapping of a
hardware queue on request completion, if the caller knows this
information already.
Signed-off-by: Jens Axboe <axboe@fb.com>

Drivers that know they are blk-mq should just use this function
instead of calling through blk_put_request().
Signed-off-by: Jens Axboe <axboe@fb.com>

blk-mq is using preempt_disable/enable in order to ensure that the
queue runners are placed on the right CPU.  This does not work with
the RT patches, because __blk_mq_run_hw_queue takes a non-raw
spinlock with the preemption-disabled region.  If there is contention
on the lock, this violates the rules for preemption-disabled regions.

While this should be easily fixable within the RT patches just by doing
migrate_disable/enable, we can do better and document _why_ this
particular region runs with disabled preemption.  After the previous
patch, it is trivial to switch it to get/put_cpu; the RT patches then
can change it to get_cpu_light, which lets virtio-blk run under RT
kernels.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Clark Williams <williams@redhat.com>
Tested-by: Clark Williams <williams@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

preempt_disable/enable surrounds every call to blk_mq_run_hw_queue,
except the one in blk-flush.c.  In fact that one is always asynchronous,
and it does not need smp_processor_id().

We can do the same for all other calls, avoiding preempt_disable when
async is true.  This avoids peppering blk-mq.c with preemption-disabled
regions.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Clark Williams <williams@redhat.com>
Tested-by: Clark Williams <williams@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Old backward-compat cruft
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

A connection timeout affects all volumes of a resource!
Under the following conditions:

 A resource with multiple volumes
  AND
 ko-count >=1
  AND
 a write request triggers the timeout (ko-count * timeout)

DRBD's internal state gets confused. That in turn may
lead to very miss leading follow up failures. E.g.
"BUG: scheduling while atomic"

CC: stable@kernel.org # v3.17
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

This was not noticed for many years. Affects operation if
md raid is used a backing device for DRBD.

CC: stable@kernel.org # v3.2+
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

If for some reason DRBD resync was the only activity on a backend
device, drbd_rs_c_min_rate_throttle() would mistakenly decide that it is
still initialization time, and keep throttling the resync.

This patch explicitly initializes ->rs_last_events to the current
backend event counters, and drops the rs_last_events == 0 from the
throttle condition.
Reported-by: Mikhail Sugakov <msugakov@amazon.de>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Symptoms:
If DRBD was "cleanly shut down" (all in sync, both Secondary before
disconnect, identical data generation uuids), and then one side was
promoted *during* the next connection handshake, the role change
could confuse the handshake.

The Primary would get stuck in WFBitmapS, the Secondary would log
unexpected cstate (Connected) in receive_bitmap
and get stuck in WFBitmapT.

Fix:
The test in is_valid_soft_transition wrong. It works because
the not allowed actions (promote/attach) do not touch the
cstate. The previous condition failed to demand a cstate change
in one clause.

In order to avoid deadlocks give up the state_mutex while waiting
for the transient state to go away.

Conflicts:
	drbd/drbd_state.c
	drbd/drbd_state.h
	drbd/drbd_wrappers.h
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Avoid generic netlink calls in other parts of the code base.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

 . Update comments
 . drbd_set_{in,out_of}_sync(): Remove unused parameters
 . Move common code into adm_del_resource()
 . Redefine ERR_MINOR_EXISTS -> ERR_MINOR_OR_VOLUME_EXISTS
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/block/nvme-core.c:865:5: sparse: symbol '__nvme_submit_admin_cmd' was not declared. Should it be static?
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

We recently converted this to blk_mq but the error checks have to be
updated to check for IS_ERR() instead of NULL.

Fixes: a4aea562 ('NVMe: Convert to blk-mq')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

This converts the NVMe driver to a blk-mq request-based driver.

The NVMe driver is currently bio-based and implements queue logic within
itself.  By using blk-mq, a lot of these responsibilities can be moved
and simplified.

The patch is divided into the following blocks:

 * Per-command data and cmdid have been moved into the struct request
   field. The cmdid_data can be retrieved using blk_mq_rq_to_pdu() and id
   maintenance are now handled by blk-mq through the rq->tag field.

 * The logic for splitting bio's has been moved into the blk-mq layer.
   The driver instead notifies the block layer about limited gap support in
   SG lists.

 * blk-mq handles timeouts and is reimplemented within nvme_timeout().
   This both includes abort handling and command cancelation.

 * Assignment of nvme queues to CPUs are replaced with the blk-mq
   version. The current blk-mq strategy is to assign the number of
   mapped queues and CPUs to provide synergy, while the nvme driver
   assign as many nvme hw queues as possible. This can be implemented in
   blk-mq if needed.

 * NVMe queues are merged with the tags structure of blk-mq.

 * blk-mq takes care of setup/teardown of nvme queues and guards invalid
   accesses. Therefore, RCU-usage for nvme queues can be removed.

 * IO tracing and accounting are handled by blk-mq and therefore removed.

 * Queue suspension logic is replaced with the logic from the block
   layer.

Contributions in this patch from:

  Sam Bradshaw <sbradshaw@micron.com>
  Jens Axboe <axboe@fb.com>
  Keith Busch <keith.busch@intel.com>
  Robert Nelson <rlnelson@google.com>
Acked-by: Keith Busch <keith.busch@intel.com>
Acked-by: Jens Axboe <axboe@fb.com>

Updated for new ->queue_rq() prototype.
Signed-off-by: Jens Axboe <axboe@fb.com>

Discard requests are often for very large ranges. The discard size is not
representative of the data transfer size so we don't need to allocate
for such a large prp list. This patch requests allocating only enough
for the memory needed for the data transfer and saves a little over 8k
of memory per max discard request.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reported-by: Paul Grabinar <paul.grabinar@ranbarg.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

It is possible the block layer will request to open a block device after
the driver deleted it. Subsequent releases will cause a double free,
or the disk's private_data is pointing to freed memory. This patch
protects the driver's freed disks from being opened and accessed: the
nvme namespaces are freed only when the device's refcount is 0, so at
that moment there were no active openers and no more should be allowed,
and it is safe to clear the disk's private_data that is about to be freed.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reported-by: Henry Chow <henry.chow@oracle.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

The nvme namespace request_queue's flags are initialized to
QUEUE_FLAG_DEFAULT, which currently sets QUEUE_FLAG_STACKABLE. The
device-mapper indicates this flag means the block driver is requset
based, though this driver is bio-based and problems will occur if an nvme
namespace is used with a request based dm device. This patch clears the
stackable flag.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

If we ever do parallel device probing, we need to wake up all processes
waiting for nvme kthread to start, not just one. This is currently
serialized so the bug is not reachable today, but fixing this anyway in
the hopes we implement parallel or asynchronous probe in the future.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Updating commands and structures for NVMe 1.1 updates, mostly for nvme
reservations. There are no additional in-kernel uses, but this is for
the uapi.

While doing this, I noticed that the software progress features was
using the wrong value, so updating that value as well.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

The NVME_IOCTL_SUBMIT_IO only works for IO commands with block data
transfers and isn't usable for other NVMe commands like flush,
data set management, or any sort of vendor unique command. The
NVME_IOCTL_ADMIN_CMD, however, can easily be modified to accept arbitrary
IO commands in addition to arbitrary admin commands without breaking
backward compatibility. This patch just adds a new IOCTL to distinguish
if the driver should submit the command on an IO or Admin queue.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

This adds a callback to revalidate the disk and change its block size
and capacity if needed. Before, a user would have to remove + rescan
an entire device if they changed the logical block size using an NVMe
Format or other vendor specific command; now they can just run something
that issues the BLKRRPART IOCTL, like

 # hdparm -z /dev/nvmeXnY

This can also be used in response to the 1.2 Spec's Namespace Attribute
Change asynchronous event.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

We need to update the nvme queue's wait_queue_t entry during each
initialization since the nvme_thread may be ended and restarted when
the device is reset. If a device reset occurs during a large amount
of buffered IO, it would take a lot longer to complete the outstanding
requests due to the 1 second polling instead of waking up as completions
occur.

Fixes: b9afca3eSigned-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

This returns a more appropriate error for the "capacity exceeded"
status. In case other NVMe statuses have a better errno, this patch adds
a convience function to translate an NVMe status code to an errno for
IO commands, defaulting to the current -EIO.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

We've only been setting the sg_io_hdr status values on SCSI commands
that require an nvme command to complete the translation. The fields
in the struct are output parameters, so we have to set them, otherwise
user space will see whatever was in memory from before. In the case of
compat SG_IO, this would reveal kernel memory. This fixes the issue by
initializing the sg_io_hdr with successful status.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Acked-by: Vishal Verma <vishal.l.verma@linux.intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

We can return -ENOIOCTLCMD and the ioctl will be handled by
fs/compat_ioctl.c instead. This removes a lot of duplicate code in the
nvme driver.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

If an nvme device is removed but user space has an open reference,
the nvme driver would have been holding an invalid reference to its pci
device. You may get a general protection fault on x86 h/w when the driver
uses that reference in dma_map_sg(), as is done in nvme_map_user_pages()
from the IOCTL interface.

This patch fixes the fault by taking a reference on the pci device and
holding it even after device removal until all opens on the nvme device
are closed.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reported-by: Nilesh Choudhury <nilesh.choudhury@oracle.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

The use of "rcu_assign_pointer()" is NULLing out the pointer.
According to RCU_INIT_POINTER()'s block comment:
"1.   This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a
smaller overhead.

The following Coccinelle semantic patch was used:
@@
@@

- rcu_assign_pointer
+ RCU_INIT_POINTER
  (..., NULL)
Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

nvme_submit_io_cmd() uses smp_processor_id() to pick an IO queue index.
This patch fixes the case where there are more cpus from which the ioctl
call can originate than online queues, which can happen when a device
supports or was allocated fewer interrupt vectors than exist cpu cores.

Thanks to Keith Busch for the implementation suggestion.
Signed-off-by: Sam Bradshaw <sbradshaw@micron.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

This changes the order of deleting the gendisks so it happens after the
nvme IO queues are freed. If a device is removed while a filesystem has
associated dirty data, the removal will wait on these to complete before
proceeding from del_gendisk, which could have caused deadlock before.

The implication of this is that an orderly removal of a responsive
device won't necessarily wait for dirty data to be written, but we are
not guaranteed the device is even going to respond at this point either.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Rather than relying on call_rcu, this patch directly frees the
nvme_queue's memory after ensuring no readers exist. Some arch specific
dma_free_coherent implementations may not be called from a call_rcu's
soft interrupt context, hence the change.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reported-by: Matthew Minter <matthew_minter@xyratex.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

The current implementation hard-codes the shutdown timeout to 2 seconds.
Some devices take longer than this to complete a normal shutdown.
Changing the shutdown timeout to a module parameter with a default
timeout of 5 seconds.
Signed-off-by: Dan McLeran <daniel.mcleran@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Rather than skipping shutdown only for devices that have been removed,
skip the orderly shutdown on failed devices to avoid the long timeout
handling that inevitably happens when deleting queues on such a device.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Fixing tabs inadvertently converted to spaces.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Race conditions are theoretically possible between the NVMe PCI device
removal and the generic PCI bus rescan and device removal that can be
triggered via sysfs.

To avoid those race conditions make the NVMe code use
pci_stop_and_remove_bus_device_locked().
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

This is a minor refactor for handling devices that are incapable of IO.
The driver previously used special error codes to know that IO queues
are unavailable, but we have an online queue count now.

This also fixes an issue where the driver successfully sets the queue
count, but either is unable to allocate an IO queue or the device can't
create one for some reason.

If the driver can successfully enable the device and get responses to
admin commands, the driver will bring up a character device for managment
but not create block devices.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Change the behavior of nvme_enable_ctrl to set EN.
Clear CC.SH for both nvme_enable_ctrl and nvme_disable_ctrl.
Remove reading of the CC register and manage the state in
dev->ctrl_config.
Signed-off-by: Dan McLeran <daniel.mcleran@intel.com>
[removed an unwanted write to CC]
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Adds support for devices with max page size smaller than the host's.
In the case we encounter such a host/device combination, the driver will
split a page into as many PRP entries as necessary for the device's page
size capabilities. If the device's reported minimum page size is greater
than the host's, the driver will not attempt to enable the device and
return an error instead.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Taken from the draft NVMe 1.1b specification.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Submits NVMe asynchronous event requests, one event up to the controller
maximum or number of possible different event types (8), whichever is
smaller. Events successfully returned by the controller are logged.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>