Commit graph

88 commits

Author SHA1 Message Date
Christoph Hellwig
329dd7681c nvme.h: add an enum for cns values
Ported over from nvme-cli.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-19 11:36:22 -06:00
Christoph Hellwig
8d63687afd nvme.h: don't use uuid_be
This makes life easier for nvme-cli and we don't really need the uuid
type anyway to start with.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Reviewed-by: Jay Freyensee <james_p_freyensee@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-19 11:36:22 -06:00
Christoph Hellwig
a446c0840e nvme.h: resync with nvme-cli
Import a few updates to nvme.h from nvme-cli.  This mostly includes a few
new fields and error codes, but also a few renames that so far are only
used in user space.  Also one field is moved from an array of two le64
values to one of 16 u8 values so that we can more easily access it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-19 11:36:22 -06:00
Gabriel Krisman Bertazi
8ef2074d28 nvme: Add tertiary number to NVME_VS
NVMe 1.2.1 specification adds a tertiary element to the version number.
This updates the macro and its callers to include the final number and
fixup a single place in nvmet where the version was generated manually.

Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-19 11:36:22 -06:00
Daniel Verkamp
7a665d2f60 nvme-fabrics: change NQN UUID to big-endian format
NVM Express 1.2.1 section 7.9, NVMe Qualified Names, specifies that the
UUID format of NQN uses a UUID based on RFC 4122.

RFC 4122 specifies that the UUID is encoded in big-endian byte order.

Switch the NVMe over Fabrics host ID field from little-endian UUID to
big-endian UUID to match the specification.

Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Jay Freyensee <james_p_freyensee@linux.intel.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
2016-08-19 12:00:44 +03:00
Sagi Grimberg
7b89eae29e nvme.h: Add keep-alive opcode and identify controller attribute
KAS: keep-alive support and granularity of kato in units of 100 ms
nvme_admin_keep_alive opcode: 0x18

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-05 11:28:18 -06:00
Christoph Hellwig
eb793e2c92 nvme.h: add NVMe over Fabrics definitions
The NVMe over Fabrics specification defines a protocol interface and
related extensions to NVMe that enable operation over network protocols.
The NVMe over Fabrics specification has an NVMe Transport binding for
each NVMe Transport.

This patch adds the fabrics related definitions:
- fabric specific command set and error codes
- transport addressing and binding definitions
- fabrics sgl extensions
- controller identification fabrics enhancements
- discovery log page definition

Signed-off-by: Armen Baloyan <armenx.baloyan@intel.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Jay Freyensee <james.p.freyensee@intel.com>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-05 11:28:14 -06:00
Christoph Hellwig
7a5abb4b48 nvme: factor out a add nvme_is_write helper
Centralize the check if a given NVMe command reads or writes data.

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jay Freyensee <james.p.freyensee@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-12 07:29:43 -06:00
James Smart
3972be23bd nvme.h: add constants for PSDT and FUSE values
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-12 07:29:43 -06:00
Christoph Hellwig
79f370eac6 nvme.h: add AER constants
Reviewed-by: Jay Freyensee <james.p.freyensee@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-12 07:29:43 -06:00
Christoph Hellwig
69cd27e251 nvme.h: add NVM command set SQE/CQE size defines
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-12 07:29:43 -06:00
Armen Baloyan
725b358836 nvme.h: Add get_log_page command strucure
Add get_log_page command structure and a corresponding entry in
nvme_command union

Signed-off-by: Armen Baloyan <armenx.baloyan@intel.com>
Reviewed-by: Jay Freyensee <james.p.freyensee@intel.com>
Reviewed--by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-12 07:29:43 -06:00
Christoph Hellwig
14e974a84e nvme.h: add RTD3R, RTD3E and OAES fields
These have been added in NVMe 1.2 and we'll need at least oaes for the
NVMe target driver.

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jay Freyensee <james.p.freyensee@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-12 07:29:43 -06:00
Wang Sheng-Hui
a5b714ad39 NVMe: correct comment for offset enum of controller registers in nvme.h
Section 3.1 gives the comment for the offset of controller registers
in the specification 1.2a.

Some are mis-copied in the header file nvme.h. Correct them.

Signed-off-by: Wang Sheng-Hui <shhuiw@foxmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-05-02 09:13:35 -06:00
Christoph Hellwig
7a67cbea65 nvme: use offset instead of a struct for registers
This makes life easier for future non-PCI drivers where access to the
registers might be more complicated.  Note that Linux drivers are
pretty evenly split between the two versions, and in fact the NVMe
driver already uses offsets for the doorbells.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
[Fixed CMBSZ offset]
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-01 10:59:38 -07:00
Christoph Hellwig
2812dfe370 nvme: include <linux/types.ĥ> in <linux/nvme.h>
The buildbot complains about this even if it doesn't generate
a a build warning.  But it's an easy fix, so here we go:

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-09 10:40:37 -06:00
Christoph Hellwig
08c69640cf nvme.h: add missing nvme_id_ctrl endianess annotations
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-09 10:40:37 -06:00
Christoph Hellwig
9d99a8dda1 nvme: move hardware structures out of the uapi version of nvme.h
Currently all NVMe command and completion structures are exposed to userspace
through the uapi version of nvme.h.  They are not an ABI between the kernel
and userspace, and will change in C-incompatible way for future versions of
the spec.  Move them to the kernel version of the file and rename the uapi
header to nvme_ioctl.h so that userspace can easily detect the presence of
the new clean header.  Nvme-cli already carries a local copy of the header,
so it won't be affected by this move.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-09 10:40:37 -06:00
Christoph Hellwig
f11bb3e244 nvme: add a local nvme.h header
Add a new drivers/block/nvme.h which contains all the driver internal
interface.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-09 10:40:37 -06:00
Keith Busch
0a7385ad69 NVMe: Simplify device resume on io queue failure
Releasing IO queues and disks was done in a work queue outside the
controller resume context to delete namespaces if the controller failed
after a resume from suspend. This is unnecessary since we can resume
a device asynchronously.

This patch makes resume use probe_work so it can directly remove
namespaces if the device is manageable but not IO capable. Since the
deleting disks was the only reason we had the convoluted "reset_workfn",
this patch removes that unnecessary indirection.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-09 10:40:36 -06:00
Keith Busch
188c3568f8 NVMe: Reference count open namespaces
Dynamic namespace attachment means the namespace may be removed at any
time, so the namespace reference count can not be tied to the device
reference count. This fixes a NULL dereference if an opened namespace
is detached from a controller.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-09 10:40:36 -06:00
Jon Derrick
81f03fedcc NVMe: Add nvme subsystem reset IOCTL
Controllers can perform optional subsystem resets as introduced in NVMe
1.1. This patch adds an IOCTL to trigger the subsystem reset by writing
"NVMe" to the NSSR register.

Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-18 11:56:13 -06:00
Keith Busch
dfbac8c7ac NVMe: Add nvme subsystem reset support
Controllers part of an NVMe subsystem may be reset by any other controller
in the subsystem. If the device is capable of subsystem resets, this
patch adds detection for such events and performs appropriate controller
initialization upon subsystem reset detection.

The register bit is a RW1C type, so the driver needs to write a 1 to the
status bit to clear the subsystem reset occured bit during initialization.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-18 11:56:11 -06:00
Jon Derrick
8ffaadf742 NVMe: Use CMB for the IO SQes if available
Some controllers have a controller-side memory buffer available for use
for submissions, completions, lists, or data.

If a CMB is available, the entire CMB will be ioremapped and it will
attempt to map the IO SQes onto the CMB. The queues will be shrunk as
needed. The CMB will not be used if the queue depth is shrunk below some
threshold where it may have reduced performance over a larger queue
in system memory.

Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-21 09:40:11 -06:00
Keith Busch
a5768aa887 NVMe: Automatic namespace rescan
Namespaces may be dynamically allocated and deleted or attached and
detached. This has the driver rescan the device for namespace changes
after each device reset or namespace change asynchronous event.

There could potentially be many detached namespaces that we don't want
polluting /dev/ with unusable block handles, so this will delete disks
if the namespace is not active as indicated by the response from identify
namespace. This also skips adding the disk if no capacity is provisioned
to the namespace in the first place.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-05 10:58:34 -06:00
Christoph Hellwig
d29ec8241c nvme: submit internal commands through the block layer
Use block layer queues with an internal cmd_type to submit internally
generated NVMe commands.  This both simplifies the code a lot and allow
for a better structure.  For example now the LighNVM code can construct
commands without knowing the details of the underlying I/O descriptors.
Or a future NVMe over network target could inject commands, as well as
could the SCSI translation and ioctl code be reused for such a beast.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-22 08:37:20 -06:00
Christoph Hellwig
e75ec752d7 nvme: store a struct device pointer in struct nvme_dev
Most users want the generic device, so store that in struct nvme_dev
instead of the pci_dev.  This also happens to be a nice step towards
making some code reusable for non-PCI transports.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-22 08:36:33 -06:00
Christoph Hellwig
f705f837c5 nvme: consolidate synchronous command submission helpers
Note that we keep the unused timeout argument, but allow callers to
pass 0 instead of a timeout if they want the default.  This will allow
adding a timeout to the pass through path later on.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-22 08:36:31 -06:00
Keith Busch
a67a95134f NVMe: Meta data handling through submit io ioctl
This adds support for the extended metadata formats through the submit
IO ioctl, and simplifies the rest when using a separate metadata format.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-07 19:11:06 -06:00
Keith Busch
07836e659c NVMe: Fix potential corruption during shutdown
The driver has to end unreturned commands at some point even if the
controller has not provided a completion. The driver tried to be safe by
deleting IO queues prior to ending all unreturned commands. That should
cause the controller to internally abort inflight commands, but IO queue
deletion request does not have to be successful, so all bets are off. We
still have to make progress, so to be extra safe, this patch doesn't
clear a queue to release the dma mapping for a command until after the
pci device has been disabled.

This patch removes the special handling during device initialization
so controller recovery can be done all the time. This is possible since
initialization is not inlined with pci probe anymore.

Reported-by: Nilish Choudhury <nilesh.choudhury@oracle.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
2015-02-19 16:15:37 -07:00
Keith Busch
2e1d844819 NVMe: Asynchronous controller probe
This performs the longest parts of nvme device probe in scheduled work.
This speeds up probe significantly when multiple devices are in use.

Signed-off-by: Keith Busch <keith.busch@intel.com>
2015-02-19 16:15:36 -07:00
Keith Busch
b3fffdefab NVMe: Register management handle under nvme class
This creates a new class type for nvme devices to register their
management character devices with. This is so we do not rely on miscdev
to provide enough minors for as many nvme devices some people plan to
use. The previous limit was approximately 60 NVMe controllers, depending
on the platform and kernel. Now the limit is 1M, which ought to be enough
for anybody.

Since we have a new device class, it makes sense to attach the block
devices under this as well, so part of this patch moves the management
handle initialization prior to the namespaces discovery.

Signed-off-by: Keith Busch <keith.busch@intel.com>
2015-02-19 16:15:36 -07:00
Keith Busch
4f1982b4e2 NVMe: Update SCSI Inquiry VPD 83h translation
The original translation created collisions on Inquiry VPD 83 for many
existing devices. Newer specifications provide other ways to translate
based on the device's version can be used to create unique identifiers.

Version 1.1 provides an EUI64 field that uniquely identifies each
namespace, and 1.2 added the longer NGUID field for the same reason.
Both follow the IEEE EUI format and readily translate to the SCSI device
identification EUI designator type 2h. For devices implementing either,
the translation will use this type, defaulting to the EUI64 8-byte type if
implemented then NGUID's 16 byte version if not. If neither are provided,
the 1.0 translation is used, and is updated to use the SCSI String format
to guarantee a unique identifier.

Knowing when to use the new fields depends on the nvme controller's
revision. The NVME_VS macro was not decoding this correctly, so that is
fixed in this patch and moved to a more appropriate place.

Since the Identify Namespace structure required an update for the NGUID
field, this patch adds the remaining new 1.2 fields to the structure.

Signed-off-by: Keith Busch <keith.busch@intel.com>
2015-02-19 16:15:35 -07:00
Keith Busch
e1e5e5641e NVMe: Metadata format support
Adds support for NVMe metadata formats and exposes block devices for
all namespaces regardless of their format. Namespace formats that are
unusable will have disk capacity set to 0, but a handle to the block
device is created to simplify device management. A namespace is not
usable when the format requires host interleave block and metadata in
single buffer, has no provisioned storage, or has better data but failed
to register with blk integrity.

The namespace has to be scanned in two phases to support separate
metadata formats. The first establishes the sector size and capacity
prior to invoking add_disk. If metadata is required, the capacity will
be temporarilly set to 0 until it can be revalidated and registered with
the integrity extenstions after add_disk completes.

The driver relies on the integrity extensions to provide the metadata
buffer. NVMe requires this be a single physically contiguous region,
so only one integrity segment is allowed per command. If the metadata
is used for T10 PI, the driver provides mappings to save and restore
the reftag physical block translation. The driver provides no-op
functions for generate and verify if metadata is not used for protection
information. This way the setup is always provided by the block layer.

If a request does not supply a required metadata buffer, the command
is failed with bad address. This could only happen if a user manually
disables verify/generate on such a disk. The only exception to where
this is okay is if the controller is capable of stripping/generating
the metadata, which is possible on some types of formats.

The metadata scatter gather list now occupies the spot in the nvme_iod
that used to be used to link retryable IOD's, but we don't do that
anymore, so the field was unused.

Signed-off-by: Keith Busch <keith.busch@intel.com>
2015-02-19 16:15:35 -07:00
Jens Axboe
ac3dd5bd12 NVMe: avoid kmalloc/kfree for smaller IO
Currently we allocate an nvme_iod for each IO, which holds the
sg list, prps, and other IO related info. Set a threshold of
2 pages and/or 8KB of data, below which we can just embed this
in the per-command pdu in blk-mq. For any IO at or below
NVME_INT_PAGES and NVME_INT_BYTES, we save a kmalloc and kfree.

For higher IOPS, this saves up to 1% of CPU time.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
2015-01-29 09:25:34 -08:00
Matias Bjørling
a4aea5623d NVMe: Convert to blk-mq
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>
2014-11-04 13:18:52 -07:00
Keith Busch
1d09062460 NVMe: Mismatched host/device page size support
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>
2014-11-04 13:17:07 -07:00
Keith Busch
6fccf9383b NVMe: Async event request
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>
2014-11-04 13:17:07 -07:00
Keith Busch
f3db22feb5 NVMe: Fix hot cpu notification dead lock
There is a potential dead lock if a cpu event occurs during nvme probe
since it registered with hot cpu notification. This fixes the race by
having the module register with notification outside of probe rather
than have each device register.

The actual work is done in a scheduled work queue instead of in the
notifier since assigning IO queues has the potential to block if the
driver creates additional queues.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-06-13 10:43:34 -04:00
Matthew Wilcox
bd67608a61 NVMe: Rename io_timeout to nvme_io_timeout
It's positively immoral to have a global variable called 'io_timeout'.
Keep the module parameter called io_timeout, though.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-06-03 23:04:30 -04:00
Keith Busch
53562be74b NVMe: Flush with data support
It is possible a filesystem may send a flush flagged bio with write
data. There is no such composite NVMe command, so the driver sends flush
and write separately.

The device is allowed to execute these commands in any order, so it was
possible the driver ends the bio after the write completes, but while the
flush is still active. We don't want to let a filesystem believe flush
succeeded before it really has; this could cause data corruption on a
power loss between these events. To fix, this patch splits the flush
and write into chained bios.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-05-05 10:54:02 -04:00
Keith Busch
a7d2ce2832 NVMe: Configure support for block flush
This configures an nvme request_queue as flush capable if the device
has a volatile write cache present.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-05-05 10:53:53 -04:00
Matthew Wilcox
8757ad65d3 NVMe: Update copyright headers
Make the copyright dates accurate and remove the final paragraph that
includes the address of the FSF.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-05-05 10:41:25 -04:00
Linus Torvalds
3e8072d48b Merge git://git.infradead.org/users/willy/linux-nvme
Pull NVMe driver updates from Matthew Wilcox:
 "Various updates to the NVMe driver.  The most user-visible change is
  that drive hotplugging now works and CPU hotplug while an NVMe drive
  is installed should also work better"

* git://git.infradead.org/users/willy/linux-nvme:
  NVMe: Retry failed commands with non-fatal errors
  NVMe: Add getgeo to block ops
  NVMe: Start-stop nvme_thread during device add-remove.
  NVMe: Make I/O timeout a module parameter
  NVMe: CPU hot plug notification
  NVMe: per-cpu io queues
  NVMe: Replace DEFINE_PCI_DEVICE_TABLE
  NVMe: Fix divide-by-zero in nvme_trans_io_get_num_cmds
  NVMe: IOCTL path RCU protect queue access
  NVMe: RCU protected access to io queues
  NVMe: Initialize device reference count earlier
  NVMe: Add CONFIG_PM_SLEEP to suspend/resume functions
2014-04-11 16:45:59 -07:00
Keith Busch
edd10d3328 NVMe: Retry failed commands with non-fatal errors
For commands returned with failed status, queue these for resubmission
and continue retrying them until success or for a limited amount of
time. The final timeout was arbitrarily chosen so requests can't be
retried indefinitely.

Since these are requeued on the nvmeq that submitted the command, the
callbacks have to take an nvmeq instead of an nvme_dev as a parameter
so that we can use the locked queue to append the iod to retry later.

The nvme_iod conviently can be used to track how long we've been trying
to successfully complete an iod request. The nvme_iod also provides the
nvme prp dma mappings, so I had to move a few things around so we can
keep those mappings.

Signed-off-by: Keith Busch <keith.busch@intel.com>
[fixed checkpatch issue with long line]
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-04-10 17:11:59 -04:00
Keith Busch
b355084a89 NVMe: Make I/O timeout a module parameter
Increase the default timeout to 30 seconds to match SCSI.

Signed-off-by: Keith Busch <keith.busch@intel.com>
[use byte instead of ushort]
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-04-10 17:04:38 -04:00
Keith Busch
33b1e95c90 NVMe: CPU hot plug notification
Registers with hot cpu notification to rebalance, and potentially allocate
additional, io queues.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-04-10 17:03:42 -04:00
Keith Busch
42f614201e NVMe: per-cpu io queues
The device's IO queues are associated with CPUs, so we can use a per-cpu
variable to map the a qid to a cpu. This provides a convienient way
to optimally assign queues to multiple cpus when the device supports
fewer queues than the host has cpus. The previous implementation may
have assigned these poorly in these situations. This patch addresses
this by sharing queues among cpus that are "close" together and should
have a lower lock contention penalty.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-04-10 17:03:15 -04:00
Keith Busch
4f5099af4f NVMe: IOCTL path RCU protect queue access
This adds rcu protected access to a queue in the nvme IOCTL path
to fix potential races between a surprise removal and queue usage in
nvme_submit_sync_cmd. The fix holds the rcu_read_lock() here to prevent
the nvme_queue from freeing while this path is executing so it can't
sleep, and so this path will no longer wait for a available command
id should they all be in use at the time a passthrough IOCTL request
is received.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-03-24 08:54:40 -04:00
Keith Busch
5a92e700af NVMe: RCU protected access to io queues
This adds rcu protected access to nvme_queue to fix a race between a
surprise removal freeing the queue and a thread with open reference on
a NVMe block device using that queue.

The queues do not need to be rcu protected during the initialization or
shutdown parts, so I've added a helper function for raw deferencing
to get around the sparse errors.

There is still a hole in the IOCTL path for the same problem, which is
fixed in a subsequent patch.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-03-24 08:45:57 -04:00