The nvme driver deletes IO queues asynchronously since this operation
may potentially take an undesirable amount of time with a large number
of queues if done serially.

The driver used to manage coordinating asynchronous deletions. This
patch simplifies that by leveraging the block layer rather than using
kthread workers and chaining more complicated callbacks.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

NVMe submits all commands through the block layer now. This means we
can let requests queue at the blk-mq hardware context since there is no
path that bypasses this anymore so we don't need to freeze the queues
anymore. The driver can simply stop the h/w queues from running during
a reset instead.

This also fixes a WARN in percpu_ref_reinit when the queue was unfrozen
with requeued requests.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

A negative status has the "do not retry" bit set, which makes it not
retryable.  Use a fake status that can potentially be retried on reset.

An aborted command's status is overridden by the timeout handler so
that it won't be retried, which is necessary to keep initialization from
getting into a reset loop.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

The tag set queue depth needs to be one less than the h/w queue depth
so we don't wrap the circular buffer. This conforms to the specification
defined "Full Queue" condition.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Translation SCSI commands to NVMe commands is rather pointless in general
as applications must not expext to be able to use SCSI commands on a
generic block device.

Make the huge translation layer optional and hope no one will ever enable
it in the future.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

Make sure we synchronize access to the namespaces list and grab a reference
to the namespace before doing I/O.  Make sure to reject the ioctl if multiple
namespaces are present as it's entirely unsafe, and warn when using it even
with a single namespace.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Currently traversal and modification of ctrl->namespaces happens completely
unsynchronized, which can be fixed by the addition of a simple mutex.

Note: nvme_dev_ioctl will be handled in the next patch.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Nothing pci specific about them and We'll need them exported
in other transports too.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

We are having build failure with sparc allmodconfig with the error:

drivers/nvme/host/pci.c:15:0:
include/linux/aer.h: In function 'pci_enable_pcie_error_reporting':
include/linux/aer.h:49:10: error: 'EINVAL' undeclared (first use in this function)

The file aer.h is using the error values but they are defined in
errno.h. Include errno.h so that we have the definitions of the error
codes.

Fixes: a0a3408e ("NVMe: Add pci error handlers")
Cc: Keith Busch <keith.busch@intel.com>
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Jens Axboe <axboe@fb.com>

Exposes the NGUID, EUI-64, and NSID to sysfs entries under the disk's
kobject.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Requests enabling pcie aer support. Shuts down the controller on error
detected with io frozen state prior to requesting slot reset; resumes
controller after reset completes.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

This was added for the 'magic' AEN requests in the NVMe driver that never
return.  We now handle them purely inside the driver and don't need this
core hack any more.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Merge the two per-request structures in the nvme driver into a single
one.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

We need to move freeing of resources to the ->complete handler to ensure
they are also freed when we cancel the command.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Now that all commands are executed as block layer requests we can remove the
internal completion in the NVMe driver.  Note that we can simply call
blk_mq_complete_request to abort commands as the block layer will protect
against double copletions internally.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

AEN requests are different from other requests in that they don't time out
or can easily be cancelled.  Because of that we should not use the blk-mq
infrastructure but just special case them in the completion path.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

And remove the now unused nvme_submit_cmd helper.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

We'll need them in other places later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

The number in tag_set->queue depth includes the reserved tags.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

We no longer require the two-pass setup for block integrity.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

We don't want to allow new references to open on a device that is
removed. This ties the lifetime of these handles to the physical device's
presence rather than to the open reference count.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Removes all usage of the global work queue so work can't be
scheduled on two different work queues, and removes nvme's work queue
singlethreadedness so controllers can be driven in parallel.
Signed-off-by: Keith Busch <keith.busch@intel.com>
[hch: keep the dead controller removal on the system workqueue to avoid
 deadlocks]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

The NVMe 1.1 specification provides an identify mode to return a
list of active namespaces. This is more efficient to discover which
namespace identifiers are active on a controller, providing potentially
significant improvement in scan time for controllers with sparesly
populated namespaces.
Signed-off-by: Keith Busch <keith.busch@intel.com>
[hch: add quirk for the broken Qemu Identify implementation.  To be relaxed
 later]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

There is no lock to sychronize access to the abort_limit field of
struct nvme_ctrl, so switch it to an atomic_t.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Compared to the kthread this gives us multiple call prevention for free.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

If we're using two work queues we're always going to run into races where
one item is tearing down what the other one is initializing.  So insted
merge the two work queues, and let the old probe_work also tear the
controller down first if it was alive.  Together with the better detection
of the probe path using a flag this gives us a properly serialized
reset/probe path that also doesn't accidentally trigger when two commands
time out and the second one tries to reset the controller while the first
reset is still in progress.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Otherwise we're never going to complete a command when it is restarted just
after we completed all other outstanding commands in nvme_clear_queue.

The controller must be disabled prior to completing a presumed lost
command, do this by directly shutting down the controller before
queueing the reset work, and return EH_HANDLED from the timeout handler
after we shut the controller down.
Signed-off-by: Keith Busch <keith.busch@intel.com>
[hch: split and rebase]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

Don't delete the controller from dev_list before queuing a reset, instead
just check for it being reset in the polling kthread.  This allows to remove
the dev_list_lock in various places, and in addition we can simply rely on
checking the queue_work return value to see if we could reset a controller.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

To properly document how we are using a negative Linux error value to
communicate request cancellations inside the driver.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

We want to be able to return bettern error values frmo nvme_timeout, which
is significantly easier if the two functions are merged.  Also clean up and
reduce the printk spew so that we only get one message per abort.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

There is nothing it protects, but it makes lockdep unhappy in many different
ways.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Signed-off-by: Keith Busch <keith.busch@intel.com>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

Without this we can easily get bad derferences on nvmeq->d_db when the nvme
kthread tries to poll the CQs for controllers that are in half initialized
state.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Half initialized queues due to kernel error returns or timeout are still a
good reason to give up on initializing a controller.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Timer context is not very useful for drivers to perform any meaningful abort
action from.  So instead of calling the driver from this useless context
defer it to a workqueue as soon as possible.

Note that while a delayed_work item would seem the right thing here I didn't
dare to use it due to the magic in blk_add_timer that pokes deep into timer
internals.  But maybe this encourages Tejun to add a sensible API for that to
the workqueue API and we'll all be fine in the end :)

Contains a major update from Keith Bush:

"This patch removes synchronizing the timeout work so that the timer can
 start a freeze on its own queue. The timer enters the queue, so timer
 context can only start a freeze, but not wait for frozen."
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

The "|" operator has higher precedence than "?:" so this didn't work as
intended.  I had previously fixed this bug, but it we copied the older
unfixed version when we moved the function between files.

Fixes: 1673f1f0 ('nvme: move block_device_operations and ns/ctrl freeing to common code')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

We recently changed bio_integrity_alloc() to return ERR_PTRs instead of
NULL but these calls were missed.

Fixes: 06c1e390 ('blk-integrity: empty implementation when disabled')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

The nvme_user_cmd function was recently moved around from one file
to another, which made a warning reappear that I had fixed before
at some point:

drivers/nvme/host/core.c: In function 'nvme_user_cmd':
drivers/nvme/host/core.c:424:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

This applies the same workaround that we have elsewhere in the
driver with an extra type cast to uintptr_t.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 1673f1f0 ("nvme: move block_device_operations and ns/ctrl freeing to common code")
Link: https://lkml.org/lkml/2015/10/9/611Signed-off-by: Jens Axboe <axboe@fb.com>