nvmet: introduce new max queue size configuration entry

Using this port configuration, one will be able to set the maximal queue
size to be used for any controller that will be associated to the
configured port.

The default value stayed 1024 but each transport will be able to set the
its own values before enabling the port.

Introduce lower limit of 16 for minimal queue depth (same as we use in
the host fabrics drivers).

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Israel Rukshin <israelr@nvidia.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Guixin Liu <kanie@linux.alibaba.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvmet: set maxcmd to be per controller

This is a preparation for having a dynamic configuration of max queue
size for a controller. Make sure that the maxcmd field stays the same as
the MQES (+1) value as we do today.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Israel Rukshin <israelr@nvidia.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvme: port block device access to file

Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-15-adbd023e19cc@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

nvmet-tcp: peek icreq before starting TLS

Incoming connection might be either 'normal' NVMe-TCP connections
starting with icreq or TLS handshakes. To ensure that 'normal'
connections can still be handled we need to peek the first packet
and only start TLS handshake if it's not an icreq.
With that we can lift the restriction to always set TREQ to
'required' when TLS1.3 is enabled.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvmet-tcp: enable TLS handshake upcall

TLS handshake is handled in userspace with the netlink tls handshake
protocol.

The patch adds a function to start the TLS handshake upcall for any
incoming network connections if the TCP TSAS sectype is set to 'tls1.3'.

A config option NVME_TARGET_TCP_TLS selects whether the TLS handshake
upcall should be compiled in. The patch also adds reference counting
to struct nvmet_tcp_queue to ensure the queue is always valid when the
the TLS handshake completes.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvmet: Set 'TREQ' to 'required' when TLS is enabled

The current implementation does not support secure concatenation,
so 'TREQ' is always set to 'required' when TLS is enabled.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvmet: Convert to bdev_open_by_path()

Convert nvmet to use bdev_open_by_path() and pass the handle around.

CC: linux-nvme@lists.infradead.org
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230927093442.25915-13-jack@suse.cz
Signed-off-by: Christian Brauner <brauner@kernel.org>

nvmet: Reorder fields in 'struct nvmet_ns'

Group some variables based on their sizes to reduce holes.
On x86_64, this shrinks the size of 'struct nvmet_ns' from 520 to 512
bytes.

When such a structure is allocated in nvmet_ns_alloc(), because of the way
memory allocation works, when 520 bytes were requested, 1024 bytes were
allocated.

So, on x86_64, this change saves 512 bytes per allocation.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvmet: reorder fields in 'struct nvmet_sq'

Group some variables based on their sizes to reduce holes.
On x86_64, this shrinks the size of 'struct nvmet_sq' from 472 to 464
bytes when CONFIG_NVME_TARGET_AUTH is defined.

This structure is embedded into some other structures, so it helps reducing
their sizes as well.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvmet: remove nvmet_req_cns_error_complete

Just fold it into the only caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

nvmet: rename nvmet_execute_identify_cns_cs_ns

nvmet_execute_identify_ns_zns is a more descriptive name for the
function handling the "I/O Command Set Specific Identify Namespace
Data Structure for the Zoned Namespace Command Set".

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

nvmet: fix I/O Command Set specific Identify Controller

For an identify command with cns set to NVME_ID_CNS_CS_CTRL, the NVMe
2.0 specification states that:

If the I/O Command Set specified by the CSI field does not have an
Identify Controller data structure, then the controller shall return
a zero filled data structure. If the host requests a data structure for
an I/O Command Set that the controller does not support, the controller
shall abort the command with a status code of Invalid Field in Command.

However, the current implementation of this identify command in
nvmet_execute_identify() only handles the ZNS command set, returning an
error for the NVM command set, which is not compliant with the
specifications as we do support this command set.

Fix this by:
1) Renaming nvmet_execute_identify_cns_cs_ctrl() to
nvmet_execute_identify_ctrl_zns() to continue handling the
ZNS command set as is.
2) Introduce a nvmet_execute_identify_ctrl_ns() helper to handle the
NVM command set, returning a zero filled nvme_id_ctrl_nvm data
structure.
3) Modify nvmet_execute_identify() to call these helpers based on
the csi specified, returning an error for unsupported command sets.

Fixes: aaf2e048af27 ("nvmet: add ZBD over ZNS backend support")
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Tested-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: expose firmware revision to configfs

Allow user to set currently active firmware revision

Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Dmitriy Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Aleksandr Miloserdov <a.miloserdov@yadro.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: expose IEEE OUI to configfs

Allow user to set OUI for the controller vendor.

Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Dmitriy Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Aleksandr Miloserdov <a.miloserdov@yadro.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: only allocate a single slab for bvecs

There is no need to have a separate slab cache for each namespace,
and having separate ones creates duplicate debugs file names as well.

Fixes: d5eff33ee6f8 ("nvmet: add simple file backed ns 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: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

nvmet-auth: don't try to cancel a non-initialized work_struct

Currently blktests nvme/002 trips up debugobjects if CONFIG_NVME_AUTH is
enabled, but authentication is not on a queue. This is because
nvmet_auth_sq_free cancels sq->auth_expired_work unconditionaly, while
auth_expired_work is only ever initialized if authentication is enabled
for a given controller.

Fix this by calling most of what is nvmet_init_auth unconditionally
when initializing the SQ, and just do the setting of the result
field in the connect command handler.

Fixes: db1312dd9548 ("nvmet: implement basic In-Band Authentication")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>

nvmet-auth: expire authentication sessions

Each authentication step is required to be completed within the
KATO interval (or two minutes if not set). So add a workqueue function
to reset the transaction ID and the expected next protocol step;
this will automatically the next authentication command referring
to the terminated authentication.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet-auth: Diffie-Hellman key exchange support

Implement Diffie-Hellman key exchange using FFDHE groups for NVMe
In-Band Authentication.
This patch adds a new host configfs attribute 'dhchap_dhgroup' to
select the FFDHE group to use.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: implement basic In-Band Authentication

Implement NVMe-oF In-Band authentication according to NVMe TPAR 8006.
This patch adds three additional configfs entries 'dhchap_key',
'dhchap_ctrl_key', and 'dhchap_hash' to the 'host' configfs directory.
The 'dhchap_key' and 'dhchap_ctrl_key' entries need to be in the ASCII
format as specified in NVMe Base Specification v2.0 section 8.13.5.8
'Secret representation'.
'dhchap_hash' defaults to 'hmac(sha256)', and can be written to to
switch to a different HMAC algorithm.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: parse fabrics commands on io queues

Some fabrics commands can be sent via io queues, so add a new
function nvmet_parse_fabrics_io_cmd() and rename the existing
nvmet_parse_fabrics_cmd() to nvmet_parse_fabrics_admin_cmd().

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: add a clear_ids attribute for passthru targets

If the clear_ids attribute is set to true, the EUI/GUID/UUID is cleared
for the passthru target. By default, loop targets will set clear_ids to
true.

This resolves an issue where a connect to a passthru target fails when
using a trtype of 'loop' because EUI/GUID/UUID is not unique.

Fixes: 2079f41ec6ff ("nvme: check that EUI/GUID/UUID are globally unique")
Signed-off-by: Alan Adamson <alan.adamson@oracle.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: use a private workqueue instead of the system workqueue

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>

nvmet: move the call to nvmet_ns_changed out of nvmet_ns_revalidate

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>

nvmet: use i_size_read() to set size for file-ns

Instead of calling vfs_getattr() use i_size_read() to read the size of
file so we can read the size of not only file type but also block type
with one call. This is needed to implement buffered_io support for the
NVMeOF block device backend.

We also change return type of function nvmet_file_ns_revalidate() from
int to void, since this function does not return any meaning value.

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: switch check for subsystem type

Invert the check for discovery subsystem type to allow for additional
discovery subsystem types.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add nvmet_is_disc_subsys() helper

Add a helper function to determine if a given subsystem is a discovery
subsystem.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add get_max_queue_size op for controllers

Some transports, such as RDMA, would like to set the queue size
according to device/port/ctrl characteristics. Add a new nvmet transport
op that is called during ctrl initialization. This will not effect
transports that don't implement this option.

Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: return bool from nvmet_passthru_ctrl and nvmet_is_passthru_req

The target core code never needs the host-side nvme_ctrl structure.
Open code two uses of nvmet_is_passthru_req in passthru.c, and then
switch the helpers used by the core to return bool. Also rename the
fuctions to better match their usage:

nvmet_passthru_ctrl -> nvmet_is_passthru_subsys
nvmet_req_passthru_ctrl -> nvmet_is_passthru_req

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

nvmet: looks at the passthrough controller when initializing CAP

For a passthru controller make cap initialization dependent on the cap of
the passthru controller, given that multiple Command Set support needs
to be supported by the underlying controller. For that move the
initialization of CAP later so that it can use the fully initialized
nvmet_ctrl structure.

Fixes: ab5d0b38c047 (nvmet: add Command Set Identifier support)
Signed-off-by: Adam Manzanares <a.manzanares@samsung.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
[hch: refactored the code a bit to keep it more contained in passthru.c]
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add ZBD over ZNS backend support

NVMe TP 4053 – Zoned Namespaces (ZNS) allows host software to
communicate with a non-volatile memory subsystem using zones for NVMe
protocol-based controllers. NVMeOF already support the ZNS NVMe
Protocol compliant devices on the target in the passthru mode. There
are generic zoned block devices like Shingled Magnetic Recording (SMR)
HDDs that are not based on the NVMe protocol.

This patch adds ZNS backend support for non-ZNS zoned block devices as
NVMeOF targets.

This support includes implementing the new command set NVME_CSI_ZNS,
adding different command handlers for ZNS command set such as NVMe
Identify Controller, NVMe Identify Namespace, NVMe Zone Append,
NVMe Zone Management Send and NVMe Zone Management Receive.

With the new command set identifier, we also update the target command
effects logs to reflect the ZNS compliant commands.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add Command Set Identifier support

NVMe TP 4056 allows controllers to support different command sets.
NVMeoF target currently only supports namespaces that contain
traditional logical blocks that may be randomly read and written. In
some applications there is a value in exposing namespaces that contain
logical blocks that have special access rules (e.g. sequentially write
required namespace such as Zoned Namespace (ZNS)).

In order to support the Zoned Block Devices (ZBD) backend, controllers
need to have support for ZNS Command Set Identifier (CSI).

In this preparation patch, we adjust the code such that it can now
support the default command set identifier. We update the namespace data
structure to store the CSI value which defaults to NVME_CSI_NVM
that represents traditional logical blocks namespace type.

The CSI support is required to implement the ZBD backend for NVMeOF
with host side NVMe ZNS interface, since ZNS commands belong to
the different command set than the default one.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add nvmet_req_bio put helper for backends

In current code there exists two backends which are using inline bio
optimization, that adds a duplicate code for freeing the bio.

For Zoned Block Device backend we also use the same optimzation and it
will lead to having duplicate code in the three backends: generic
bdev, passsthru, and generic zns.

Add a helper function to avoid duplicate code and update the respective
backends.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add req cns error complete helper

We report error and complete the request when identify cns value is not
handled in nvmet_execute_identify(). This error reporting is also needed
for Zone Block Device backend for NVMeOF target.

Add a helper nvmet_req_cns_error_compplete() to report an error and
complete the request when idenitfy command cns not handled value.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: use u32 for nvmet_subsys max_nsid

Use u32 type for the nsid_max member of the nvmet_subsys structure.
This avoids the type confusion when updating the subsys->nax_nsid from
ns->nsid. This also matches the nvmet_ns->nsid member.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: make sn stable once connection was established

Once some host has connected to the target, make sure that the serial
number is stable and cannot be changed.

Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Noam Gottlieb <ngottlieb@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: change sn size and check validity

According to the NVM specification, the serial_number should be 20 bytes
(bytes 23:04 of the Identify Controller data structure), and should
contain only ASCII characters.

In accordance, the serial_number size is changed to 20 bytes and before
any attempt to store a new value in serial_number we check that the
input is valid - i.e. contains only ASCII characters, is not empty and
does not exceed 20 bytes.

Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Noam Gottlieb <ngottlieb@nvidia.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: fix false keep-alive timeout when a controller is torn down

Controller teardown flow may take some time in case it has many I/O
queues, and the host may not send us keep-alive during this period.
Hence reset the traffic based keep-alive timer so we don't trigger
a controller teardown as a result of a keep-alive expiration.

Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: fix inline bio check for bdev-ns

When handling rw commands, for inline bio case we only consider
transfer size. This works well when req->sg_cnt fits into the
req->inline_bvec, but it will result in the warning in
__bio_add_page() when req->sg_cnt > NVMET_MAX_INLINE_BVEC.

Consider an I/O size 32768 and first page is not aligned to the page
boundary, then I/O is split in following manner :-

[ 2206.256140] nvmet: sg->length 3440 sg->offset 656
[ 2206.256144] nvmet: sg->length 4096 sg->offset 0
[ 2206.256148] nvmet: sg->length 4096 sg->offset 0
[ 2206.256152] nvmet: sg->length 4096 sg->offset 0
[ 2206.256155] nvmet: sg->length 4096 sg->offset 0
[ 2206.256159] nvmet: sg->length 4096 sg->offset 0
[ 2206.256163] nvmet: sg->length 4096 sg->offset 0
[ 2206.256166] nvmet: sg->length 4096 sg->offset 0
[ 2206.256170] nvmet: sg->length 656 sg->offset 0

Now the req->transfer_size == NVMET_MAX_INLINE_DATA_LEN i.e. 32768, but
the req->sg_cnt is (9) > NVMET_MAX_INLINE_BIOVEC which is (8).
This will result in the following warning message :-

nvmet_bdev_execute_rw()
bio_add_page()
__bio_add_page()
WARN_ON_ONCE(bio_full(bio, len));

This scenario is very hard to reproduce on the nvme-loop transport only
with rw commands issued with the passthru IOCTL interface from the host
application and the data buffer is allocated with the malloc() and not
the posix_memalign().

Fixes: 73383adfad24 ("nvmet: don't split large I/Os unconditionally")
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: do not allow model_number exceed 40 bytes

According to the NVM specifications, the model number size should be
40 bytes (bytes 63:24 of the Identify Controller data structure).
Therefore, any attempt to store a value into model_number which
exceeds 40 bytes should return an error.

Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Noam Gottlieb <ngottlieb@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: remove unnecessary ctrl parameter

The function nvmet_ctrl_find_get() accepts out pointer to nvmet_ctrl
structure. This function returns the same error value from two places
that is :- NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR.

Move this to the caller so we can change the return type to nvmet_ctrl.

Now that we can changed the return type, instead of taking out pointer
to the nvmet_ctrl structure remove that function parameter and return
the valid nvmet_ctrl pointer on success and NULL on failure.

Also, add and rename the goto labels for more readability with comments.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: remove an unnecessary function parameter to nvmet_check_ctrl_status

In nvmet_check_ctrl_status() cmd can be derived from nvmet_req. Remove
the local variable cmd in the nvmet_check_ctrl_status() and function
parameter cmd for nvmet_check_ctrl_status(). Derive the cmd value from
req parameter in the nvmet_check_ctrl_status().

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: model_number must be immutable once set

In case we have already established connection to nvmf target, it
shouldn't be allowed to change the model_number. E.g. if someone will
identify ctrl and get model_number of "my_model" later on will change
the model_numbel via configfs to "my_new_model" this will break the NVMe
specification for "Get Log Page – Persistent Event Log" that refers to
Model Number as: "This field contains the same value as reported in the
Model Number field of the Identify Controller data structure, bytes
63:24."

Although it doesn't mentioned explicitly that this field can't be
changed, we can assume it.

So allow setting this field only once: using configfs or in the first
identify ctrl operation.

Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add nvmet_req_subsys() helper

Just like what we have to get the passthru ctrl from the req, add an
helper to get the subsystem associated with the nvmet_req() instead
of open coding the chain of structures.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add helper to report invalid opcode

In the NVMeOF block device backend, file backend, and passthru backend
we reject and report the commands if opcode is not handled.

Add an helper and use it in block device backend to keep the code
and error message uniform.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: make nvmet_find_namespace() req based

The six callers of nvmet_find_namespace() duplicate the error log page
update and status setting code for each call on failure.

All callers are nvmet requests based functions, so we can pass req
to the nvmet_find_namesapce() & derive ctrl from req, that'll allow us
to update the error log page in nvmet_find_namespace(). Now that we
pass the request we can also get rid of the local variable in
nvmet_find_namespace() and use the req->ns and return the error code.

Replace the ctrl parameter with nvmet_req for nvmet_find_namespace(),
centralize the error log page update for non allocated namesapces, and
return uniform error for non-allocated namespace.

The nvmet_find_namespace() takes nsid parameter which is from NVMe
commands structures such as get_log_page, identify, rw and common. All
these commands have same offset for the nsid field.

Derive nsid from req->cmd->common.nsid) & remove the extra parameter
from the nvmet_find_namespace().

Lastly now we associate the ns to the req parameter that we pass to the
nvmet_find_namespace(), rename nvmet_find_namespace() to
nvmet_req_find_ns().

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add lba to sect conversion helpers

In this preparation patch, we add helpers to convert lbas to sectors &
sectors to lba. This is needed to eliminate code duplication in the ZBD
backend.

Use these helpers in the block device backend.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: remove unused ctrl->cqs

remove unused cqs from nvmet_ctrl struct
this will reduce the allocated memory.

Signed-off-by: Amit <amit.engel@dell.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: use inline bio for passthru fast path

In nvmet_passthru_execute_cmd() which is a high frequency function
it uses bio_alloc() which leads to memory allocation from the fs pool
for each I/O.

For NVMeoF nvmet_req we already have inline_bvec allocated as a part of
request allocation that can be used with preallocated bio when we
already know the size of request before bio allocation with bio_alloc(),
which we already do.

Introduce a bio member for the nvmet_req passthru anon union. In the
fast path, check if we can get away with inline bvec and bio from
nvmet_req with bio_init() call before actually allocating from the
bio_alloc().

This will be useful to avoid any new memory allocation under high
memory pressure situation and get rid of any extra work of
allocation (bio_alloc()) vs initialization (bio_init()) when
transfer len is < NVMET_MAX_INLINE_DATA_LEN that user can configure at
compile time.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add passthru io timeout value attr

NVMeOF controller in the passsthru mode is capable of handling wide set
of I/O commands including vender specific passhtru io comands.

The vendor specific I/O commands are used to read the large drive
logs and can take longer than default NVMe commands, i.e. for
passthru requests the timeout value may differ from the passthru
controller's default timeout values (nvme-core:io_timeout).

Add a configfs attribute so that user can set the io timeout values.
In case if this configfs value is not set nvme_alloc_request() will set
the NVME_IO_TIMEOUT value when request queuedata is NULL.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add passthru admin timeout value attr

NVMeOF controller in the passsthru mode is capable of handling wide set
of admin commands including vender specific passhtru admin comands.

The vendor specific admin commands are used to read the large drive
logs and can take longer than default NVMe commands, i.e. for
passthru requests the timeout value may differ from the passthru
controller's default timeout values (nvme-core:admin_timeout).

Add a configfs attribute so that user can set the admin timeout values.
In case if this configfs value is not set nvme_alloc_request() will set
the ADMIN_TIMEOUT value when request queuedata is NULL.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: handle keep-alive timer when kato is modified by a set features cmd

A user may modify the kato by a set features cmd. To properly deal
with races or a kato value of 0 (no keep alive enabled) change
nvmet_set_feat_kato to first disable the timer, then set the value
and then re-enable the timer.

Signed-off-by: Amit Engel <amit.engel@dell.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: introduce the passthru configfs interface

When CONFIG_NVME_TARGET_PASSTHRU as 'passthru' directory will
be added to each subsystem. The directory is similar to a namespace
and has two attributes: device_path and enable. The user must set the
path to the nvme controller's char device and write '1' to enable the
subsystem to use passthru.

Any given subsystem is prevented from enabling both a regular namespace
and the passthru device. If one is enabled, enabling the other will
produce an error.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: Add passthru enable/disable helpers

This patch adds helper functions which are used in the NVMeOF configfs
when the user is configuring the passthru subsystem. Here we ensure
that only one subsys is assigned to each nvme_ctrl by using an xarray
on the cntlid.

The subsystem's version number is overridden by the passed through
controller's version. However, if that version is less than 1.2.1,
then we bump the advertised version to that and print a warning
in dmesg.

Based-on-a-patch-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add passthru code to process commands

Add passthru command handling capability for the NVMeOF target and
export passthru APIs which are used to integrate passthru
code with nvmet-core.

The new file passthru.c handles passthru cmd parsing and execution.
In the passthru mode, we create a block layer request from the nvmet
request and map the data on to the block layer request.

Admin commands and features are on an allow list as there are a number
of each that don't make too much sense with passthrough. We use an
allow list such that new commands can be considered before being blindly
passed through. In both cases, vendor specific commands are always
allowed.

We also reject reservation IO commands as the underlying device cannot
differentiate between multiple hosts behind a fabric.

Based-on-a-patch-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: use xarray for ctrl ns storing

This patch replaces the ctrl->namespaces tracking from linked list to
xarray and improves the performance when accessing one namespce :-

XArray vs Default:-

IOPS and BW (more the better) increase BW (~1.8%):-
---------------------------------------------------

XArray :-
read: IOPS=160k, BW=626MiB/s (656MB/s)(18.3GiB/30001msec)
read: IOPS=160k, BW=626MiB/s (656MB/s)(18.3GiB/30001msec)
read: IOPS=162k, BW=631MiB/s (662MB/s)(18.5GiB/30001msec)

Default:-
read: IOPS=156k, BW=609MiB/s (639MB/s)(17.8GiB/30001msec)
read: IOPS=157k, BW=613MiB/s (643MB/s)(17.0GiB/30001msec)
read: IOPS=160k, BW=626MiB/s (656MB/s)(18.3GiB/30001msec)

Submission latency (less the better) decrease (~8.3%):-
-------------------------------------------------------

XArray:-
slat (usec): min=7, max=8386, avg=11.19, stdev=5.96
slat (usec): min=7, max=441, avg=11.09, stdev=4.48
slat (usec): min=7, max=1088, avg=11.21, stdev=4.54

Default :-
slat (usec): min=8, max=2826.5k, avg=23.96, stdev=3911.50
slat (usec): min=8, max=503, avg=12.52, stdev=5.07
slat (usec): min=8, max=2384, avg=12.50, stdev=5.28

CPU Usage (less the better) decrease (~5.2%):-
----------------------------------------------

XArray:-
cpu : usr=1.84%, sys=18.61%, ctx=949471, majf=0, minf=250
cpu : usr=1.83%, sys=18.41%, ctx=950262, majf=0, minf=237
cpu : usr=1.82%, sys=18.82%, ctx=957224, majf=0, minf=234

Default:-
cpu : usr=1.70%, sys=19.21%, ctx=858196, majf=0, minf=251
cpu : usr=1.82%, sys=19.98%, ctx=929720, majf=0, minf=227
cpu : usr=1.83%, sys=20.33%, ctx=947208, majf=0, minf=235.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: introduce flags member in nvmet_fabrics_ops

Replace has_keyed_sgls and metadata_support booleans with a flags member
that will be used for adding more features in the future.

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add metadata support for block devices

Allocate the metadata SGL buffers and set metadata fields for the
request. Then create a block IO request for the metadata from the
protection SG list.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add metadata/T10-PI support

Expose the namespace metadata format when PI is enabled. The user needs
to enable the capability per subsystem and per port. The other metadata
properties are taken from the namespace/bdev.

Usage example:
echo 1 > /config/nvmet/subsystems/${NAME}/attr_pi_enable
echo 1 > /config/nvmet/ports/${PORT_NUM}/param_pi_enable

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: rename nvmet_check_data_len to nvmet_check_transfer_len

The function doesn't check only the data length, because the transfer
length includes also the metadata length in some cases. This is
preparation for adding metadata (T10-PI) support.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: rename nvmet_rw_len to nvmet_rw_data_len

The function doesn't add the metadata length (only data length is
calculated). This is preparation for adding metadata (T10-PI) support.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add metadata characteristics for a namespace

Fill those namespace fields from the block device format for adding
metadata (T10-PI) over fabric support with block devices.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add helper to revalidate bdev and file ns

This patch adds a wrapper helper to indicate size change in the bdev &
file-backed namespace when revalidating ns. This helper is needed in
order to minimize code repetition in the next patch for configfs.c and
existing admin-cmd.c.  

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimbeg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add ns revalidation support

Add support for detecting capacity changes on nvmet blockdev and file
backed namespaces. This allows for emulating and testing online resizing
of nvme devices and filesystems on top.

Signed-off-by: Anthony Iliopoulos <ailiop@suse.com>
[chaitanya: Fix comments posted on V1]
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
[hch: reuse code a bit more]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: Add get_mdts op for controllers

Some transports, such as RDMA, would like to set the Maximum Data
Transfer Size (MDTS) according to device/port/ctrl characteristics.
This will enable the transport to set the optimal MDTS according to
controller needs and device capabilities. Add a new nvmet transport
op that is called during ctrl identification. This will not effect
transports that don't implement this option. The return value of the new
op is according to the NVMe spec definition for MDTS.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Israel Rukshin <israelr@mellanox.com>

nvmet: make ctrl model configurable

This patch adds a new target subsys attribute which allows user to
optionally specify model name which then used in the
nvmet_execute_identify_ctrl() to fill up the nvme_id_ctrl structure.

The default value for the model is set to "Linux" for backward
compatibility.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Mark Ruijter <MRuijter@onestopsystems.com>
[chaitanya.kulkarni@wdc.com
*Use macro for default model, coding style fixes.
*Use RCU for accessing model in for configfs and in
nvmet_execute_identify_ctrl().
]
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvmet: make ctrl-id configurable

This patch adds a new target subsys attribute which allows user to
optionally specify target controller IDs which then used in the
nvmet_execute_identify_ctrl() to fill up the nvme_id_ctrl structure.

For example, when using a cluster setup with two nodes, with a dual
ported NVMe drive and exporting the drive from both the nodes,
The connection to the host fails due to the same controller ID and
results in the following error message:-

"nvme nvmeX: Duplicate cntlid XXX with nvmeX, rejecting"

With this patch now user can partition the controller IDs for each
subsystem by setting up the cntlid_min and cntlid_max. These values
will be used at the time of the controller ID creation. By partitioning
the ctrl-ids for each subsystem results in the unique ctrl-id space
which avoids the collision.

When new attribute is not specified target will fall back to original
cntlid calculation method.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvmet: fix dsm failure when payload does not match sgl descriptor

The host is allowed to pass the controller an sgl describing a buffer
that is larger than the dsm payload itself, allow it when executing
dsm.

Reported-by: Dakshaja Uppalapati <dakshaja@chelsio.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>,
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvmet: Open code nvmet_req_execute()

Now that nvmet_req_execute does nothing, open code it.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
[split patch, update changelog]
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: Remove the data_len field from the nvmet_req struct

Instead of storing the expected length and checking it when it's
executed, just check the length inside the command themselves.

A new helper, nvmet_check_data_len() is created to help with this
check.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[split patch, udpate changelog]
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: Introduce nvmet_dsm_len() helper

Similar to the nvmet_rw_len helper.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
[split patch, update changelog]
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: Fix use-after-free bug when a port is removed

When a port is removed through configfs, any connected controllers
are still active and can still send commands. This causes a
use-after-free bug which is detected by KASAN for any admin command
that dereferences req->port (like in nvmet_execute_identify_ctrl).

To fix this, disconnect all active controllers when a subsystem is
removed from a port. This ensures there are no active controllers
when the port is eventually removed.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by : Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>

nvmet: export I/O characteristics attributes in Identify

Make the NVMe NAWUN, NAWUPF, NACWU, NPWG, NPWA, NPDG and NOWS attributes
available to initator systems for the block backend.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add transport discovery change op

Some transports, such as FC-NVME, support discovery controller change
events without the use of a persistent discovery controller. FC receives
events via RSCN from the FC Fabric Controller or subsystem FC port.

This patch adds a nvmet transport op that is called whenever a
discovery change event occurs in the nvmet layer.

To facilitate the callback without adding another layer to cross into
core.c to reference the transport ops, the port structure snapshots
the transport ops when the port is enabled and clears them when disabled.

Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: rename nvme_completion instances from rsp to cqe

Use NVMe namings for improving code readability.

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by : Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: fix discover log page when offsets are used

The nvme target hadn't been taking the Get Log Page offset parameter
into consideration, and so has been returning corrupted log pages when
offsets are used. Since many tools, including nvme-cli, split the log
request to 4k, we've been breaking discovery log responses when more
than 3 subsystems exist.

Fix the returned data by internally generating the entire discovery
log page and copying only the requested bytes into the user buffer. The
command log page offset type has been modified to a native __le64 to
make it easier to extract the value from a command.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Tested-by: Minwoo Im <minwoo.im@samsung.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: convert to SPDX identifiers

Update license to use SPDX-License-Identifier instead of verbose license
text.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

nvmet: use a macro for default error location

This patch defines a new macro NVMET_NO_ERROR_LOC to represent the
default error location value in the nvme-error-log-page.
This is a pure cleanup patch and it does not change any functionality.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add error log support for file backend

This patch adds support for the file backend to populate the
error log entries. Here we map the errno to the NVMe status codes.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add interface to update error-log page

This patch adds nvmet_req based interface to the nvmet-core so that
we can update the error log page. We update error log page in
the request completion path when status is not set to NVME_SC_SUCCESS.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add error-log definitions

This patch adds necessary fields in the target data structures to
support error log page. For a target controller, we add a new error log
field to maintain the error log, at any given point we maintain error
entries equal to NVMET_ERROR_LOG_SLOTS for each controller. In the
following patch, we also update the error log page entry in the I/O
completion path so we introduce a spinlock for synchronization of the
log.

For nvmet_req, we add a new field error_loc to hold the location of
the error in the command when the actual error occurs for each request
and a starting LBA if applicable.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme: remove nvme_common command cdw10 array

This is a preparation patch which removes the nvme common command cdw10
array and replace with individual fields. This is needed for the nvmet
error log page implementation make is error log page entry offset
assignment easier.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: Add install_queue callout

nvmet-tcp will implement it to allocate queue commands which
are only known at nvmf connect time (sq size).

Signed-off-by: Sagi Grimberg <sagi@lightbitslabs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: fix the structure member indentation

This is a cleanup patch which fixes the structure member indentation
introduced by the p2p:

commit c6925093d0b2 ("nvmet: Optionally use PCI P2P memory").
We don't change any functionality in this patch.

This is needed so that any future members will also follow the uniform
indentation.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: support fabrics sq flow control

Technical proposal 8005 "fabrics SQ flow control" introduces a mode
where a host and controller agree to omit sq_head pointer updates
when sending nvme completions.

In case the host indicated desire to operate in this mode (connect attribute)
the controller will return back a connect completion with sq_head value
of 0xffff as indication that it will omit sq_head pointer updates.

This mode saves us an atomic update in the I/O path.

Reviewed-by: Hannes Reinecke <hare@suse.com>
[hch: suggested better implementation]
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: mark nvmet_genctr static

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: enable Discovery Controller AENs

Add functions to find connections requesting Discovery Change events
and send a notification to hosts that maintain an explicit persistent
connection and have and active Asynchronous Event Request pending.
Only Hosts that have access to the Subsystem effected by the change
will receive notifications of Discovery Change event.

Call these functions each time there is a configfs change that effects
the Discover Log Pages.

Set the OAES field in the Identify Controller response to advertise the
support for Asynchronous Event Notifications.

Signed-off-by: Jay Sternberg <jay.e.sternberg@intel.com>
Reviewed-by: Phil Cayton <phil.cayton@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: allow host connect even if no allowed subsystems are exported

It is perfectly valid that a host connects to a discovery subsystem
and gets an empty discovery log page since no subsystems are
provisioned to it. No reason to disallow connecting to the discovery
subsystem all together.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jay Sternberg <jay.e.sternberg@intel.com>
Reviewed-by: Phil Cayton <phil.cayton@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: add defines for discovery change async events

Add AEN/AER values as defined by the specification

Signed-off-by: Jay Sternberg <jay.e.sternberg@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: make kato and AEN processing for use by other controllers

Make common process of get/set features available to other controllers by
making simple functions static inline and others not static and prototypes
in nvmet.h file

Also remove static from nvmet_execute_async_event and add prototype to
nvmet.h to allow used by other controllers

Signed-off-by: Jay Sternberg <jay.e.sternberg@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: allow Keep Alive for Discovery controller

Per change to specification allowing Discovery controllers to have
explicit persistent connections, remove restriction on Discovery
controllers allowing kato on connect.

Signed-off-by: Jay Sternberg <jay.e.sternberg@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: change aen mask functions to use bit numbers

Functions nvmet_aen_disabled and nvmet_clear_aen were using
values not bit numbers ie 1 << 9 not 9 for bit function clear_bit
and test_and_set_bit.

Signed-off-by: Jay Sternberg <jay.e.sternberg@intel.com>
Reviewed-by: Phil Cayton <phil.cayton@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: provide aen bit functions for multiple controller types

Move nvmet_aen_disabled and nvmet_clear_aen in preparation for other types
of controllers to use, initially the discovery controller.

Signed-off-by: Jay Sternberg <jay.e.sternberg@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: support for traffic based keep-alive

A controller that supports traffic based keep-alive can restart the keep
alive timer even when no keep-alive was not received in the kato period
as long as other admin or I/O commands were received. For each command
set ctrl->cmd_seen to true, and when keep-alive timer expires, if any
commands were seen, resched ka_work instead of escalating to a fatal
error.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: Optionally use PCI P2P memory

Create a configfs attribute in each nvme-fabrics namespace to enable P2P
memory use. The attribute may be enabled (with a boolean) or a specific
P2P device may be given (with the device's PCI name).

When enabled, the namespace will ensure the underlying block device
supports P2P and is compatible with any specified P2P device. If no device
was specified it will ensure there is compatible P2P memory somewhere in
the system. Enabling a namespace with P2P memory will fail with EINVAL
(and an appropriate dmesg error) if any of these conditions are not met.

Once a controller is set up on a specific port, the P2P device to use for
each namespace will be found and stored in a radix tree by namespace ID.
When memory is allocated for a request, the tree is used to look up the P2P
device to allocate memory against. If no device is in the tree (because no
appropriate device was found), or if allocation of P2P memory fails, fall
back to using regular memory.

Signed-off-by: Stephen Bates <sbates@raithlin.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
[hch: partial rewrite of the initial code]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

nvmet: Introduce helper functions to allocate and free request SGLs

Add helpers to allocate and free the SGL in a struct nvmet_req:

int nvmet_req_alloc_sgl(struct nvmet_req *req)
void nvmet_req_free_sgl(struct nvmet_req *req)

This will be expanded in a future patch to implement peer-to-peer memory
DMAs and should be common with all target drivers.

The new helpers are used in nvmet-rdma. Seeing we use req.transfer_len as
the length of the SGL it is set earlier and cleared on any error. It also
seems to be unnecessary to accumulate the length as the map_sgl functions
should only ever be called once per request.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sagi Grimberg <sagi@grimberg.me>

nvmet: don't split large I/Os unconditionally

If we know that the I/O size exceeds our inline bio vec, no
point using it and split the rest to begin with. We could
in theory reuse the inline bio and only allocate the bio_vec,
but its really not worth optimizing for.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add ns write protect support

This patch implements the Namespace Write Protect feature described in
"NVMe TP 4005a Namespace Write Protect". In this version, we implement
No Write Protect and Write Protect states for target ns which can be
toggled by set-features commands from the host side.

For write-protect state transition, we need to flush the ns specified
as a part of command so we also add helpers for carrying out synchronous
flush operations.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
[hch: fixed an incorrect endianess conversion, minor cleanups]
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: support configuring ANA groups

Allow creating non-default ANA groups (group ID > 1). Groups are created
either by assigning the group ID to a namespace, or by creating a configfs
group object under a specific port. All namespaces assigned to a group
that doesn't have a configfs object for a given port are marked as
inaccessible.

Allow changing the ANA state on a per-port basis by creating an
ana_groups directory under each port, and another directory with an
ana_state file in it. The default ANA group 1 directory is created
automatically for each port.

For all changes in ANA configuration the ANA change AEN is sent. We only
keep a global changecount instead of additional per-group changecounts to
keep the implementation as simple as possible.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>

nvmet: add minimal ANA support

Add support for Asynchronous Namespace Access as specified in NVMe 1.3
TP 4004.

Just add a default ANA group 1 that is optimized on all ports. This is
(and will remain) the default assignment for any namespace not epxlicitly
assigned to another ANA group. The ANA state can be manually changed
through the configfs interface, including the change state.

Includes fixes and improvements from Hannes Reinecke.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>

nvmet: track and limit the number of namespaces per subsystem

TP 4004 introduces a new 'Maximum Number of Allocated Namespaces' field
in the Identify controller data to help the host size resources. Put
an upper limit on the supported namespaces to be able to support this
value as supporting 32-bits worth of namespaces would lead to very
large buffers. The limit is completely arbitrary at this point.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>

nvmet: keep a port pointer in nvmet_ctrl

This will be needed for the ANA AEN code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>

nvmet-rdma: support max(16KB, PAGE_SIZE) inline data

The patch enables inline data sizes using up to 4 recv sges, and capping
the size at 16KB or at least 1 page size. So on a 4K page system, up to
16KB is supported, and for a 64K page system 1 page of 64KB is supported.

We avoid > 0 order page allocations for the inline buffers by using
multiple recv sges, one for each page. If the device cannot support
the configured inline data size due to lack of enough recv sges, then
log a warning and reduce the inline size.

Add a new configfs port attribute, called param_inline_data_size,
to allow configuring the size of inline data for a given nvmf port.
The maximum size allowed is still enforced by nvmet-rdma with
NVMET_RDMA_MAX_INLINE_DATA_SIZE, which is now max(16KB, PAGE_SIZE).
And the default size, if not specified via configfs, is still PAGE_SIZE.
This preserves the existing behavior, but allows larger inline sizes
for small page systems. If the configured inline data size exceeds
NVMET_RDMA_MAX_INLINE_DATA_SIZE, a warning is logged and the size is
reduced. If param_inline_data_size is set to 0, then inline data is
disabled for that nvmf port.

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: add buffered I/O support for file backed ns

Add a new "buffered_io" attribute, which disabled direct I/O and thus
enables page cache based caching when enabled. The attribute can only
be changed when the namespace is disabled as the file has to be reopend
for the change to take effect.

The possibly blocking read/write are deferred to a newly introduced
global workqueue.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: mask pending AENs

Per section 5.2 of the NVMe 1.3 spec:

"When the controller posts a completion queue entry for an outstanding
Asynchronous Event Request command and thus reports an asynchronous
event, subsequent events of that event type are automatically masked by
the controller until the host clears that event. An event is cleared by
reading the log page associated with that event using the Get Log Page
command (see section 5.14)."

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

nvmet: add AEN configuration support

AEN configuration via the 'Get Features' and 'Set Features' admin
command is mandatory, so we should be implemeting handling for it.

Signed-off-by: Hannes Reinecke <hare@suse.com>
[hch: use WRITE_ONCE, check for invalid values]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>

nvmet: implement the changed namespaces log

Just keep a per-controller buffer of changed namespaces and copy it out
in the get log page implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>

nvmet: add a new nvmet_zero_sgl helper

Zeroes the SGL in the payload.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>

nvme-loop: add support for multiple ports

This is useful at least for multipath testing.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>

nvmet: add simple file backed ns support

This patch adds simple file backed namespace support for NVMeOF target.

The new file io-cmd-file.c is responsible for handling the code for I/O
commands when ns is file backed. Also, we introduce mempools based slow
path using sync I/Os for file backed ns to ensure forward progress under
reclaim.

The old block device based implementation is moved to io-cmd-bdev.c and
use a "nvmet_bdev_" symbol prefix. The enable/disable calls are also
move into the respective files.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
[hch: updated changelog, fixed double req->ns lookup in bdev case]
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: constify struct nvmet_fabrics_ops

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

nvmet: don't return "any" ip address in discovery log page

Its perfectly valid to assign a nvmet port to listen on "any"
IP address (traddr 0.0.0.0 for ipv4 address family) for IP based
transport ports. However, we must not return this address in
discovery log entries. Instead we need to return the address
where the request was accepted on (req->port address).

Since this is nvme transport specific, introduce an optional
.disc_traddr interface that is designed to check that a
port in question is bound to "any" IP address and if so, set
the traddr from the port where the request came from.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: better data length validation

Currently the NVMe target stores the expexted data length in req->data_len
and uses that for data transfer decisions, but that does not take the
actual transfer length in the SGLs into account. So this adds a new
transfer_len field, into which the transport drivers store the actual
transfer length. We then check the two match before actually executing
the command.

The FC transport driver already had such a field, which is removed in
favour of the common one.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: synchronize sqhd update

In testing target io in read write mix, we did indeed get into cases where
sqhd didn't update properly and slowly missed enough updates to shutdown
the queue.

Protect the updating sqhd by using cmpxchg, and for that turn the sqhd
field into a u32 so that cmpxchg works on it for all architectures.

Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: bump NVMET_NR_QUEUES to 128

Raise the max number of IO queues to 128. There are several hosts with
more than 64 cpus/threads.

Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: implement valid sqhd values in completions

To support sqhd, for initiators that are following the spec and
paying attention to sqhd vs their sqtail values:

- add sqhd to struct nvmet_sq
- initialize sqhd to 0 in nvmet_sq_setup
- rather than propagate the 0's-based qsize value from the connect message
which requires a +1 in every sqhd update, and as nothing else references
it, convert to 1's-based value in nvmt_sq/cq_setup() calls.
- validate connect message sqsize being non-zero per spec.
- updated assign sqhd for every completion that goes back.

Also remove handling the NULL sq case in __nvmet_req_complete, as it can't
happen with the current code.

Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: add support for reporting the host identifier

And fix the Get/Set Log Page implementation to take all 8 bits of the
feature identifier into account.

Signed-off-by: Omri Mann <omri@excelero.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
[hch: used the UUID API, updated changelog]

nvmet: Move serial number from controller to subsystem

The NVMe specification defines the serial number as:

"Serial Number (SN): Contains the serial number for the NVM subsystem
that is assigned by the vendor as an ASCII string. Refer to section
7.10 for unique identifier requirements. Refer to section 1.5 for ASCII
string requirements"

So move it from the controller to the subsystem, where it belongs.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: implement namespace identify descriptor list

A NVMe Identify NS command with a CNS value of '3' is expecting a list
of Namespace Identification Descriptor structures to be returned to
the host for the namespace requested in the namespace identify
command.

This Namespace Identification Descriptor structure consists of the
type of the namespace identifier, the length of the identifier and the
actual identifier.

Valid types are NGUID and UUID which we have saved in our nvme_ns
structure if they have been configured via configfs. If no value has
been assigened to one of these we return an "invalid opcode" back to
the host to maintain backward compatibiliy with older implementations
without Namespace Identify Descriptor list support.

Also as the Namespace Identify Descriptor list is the only mandatory
feature change between 1.2.1 and 1.3 we can bump the advertised
version as well.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme: switch to uuid_t

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

nvmet: release the sq ref on rdma read errors

On rdma read errors, release the sq ref that was taken
when the req was initialized. This avoids a hang in
nvmet_sq_destroy() when the queue is being freed.

Signed-off-by: Vijay Immanuel <vijayi@attalasystems.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

nvmet: Introduced helper routine for controller status check.

This patch introduces helper function for checking controller
status during admin and io command processing which returns u16
status. As to bring consistency on returning status, other
friend functions also now return u16 status instead of int
to match the spec.

As part of the theseerror log prints in also prints qid on
which command error occured.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

nvmet: confirm sq percpu has scheduled and switched to atomic

percpu_ref_kill is not enough to prevent subsequent
percpu_ref_tryget_live from failing. Hence call
perfcpu_ref_kill_confirm to make it safe.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

nvmet: confirm sq percpu has scheduled and switched to atomic

percpu_ref_kill is not enough to prevent subsequent
percpu_ref_tryget_live from failing. Hence call
perfcpu_ref_kill_confirm to make it safe.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>

nvmet: Make cntlid globally unique

We usually log the cntlid which is confusing in case
we have multiple subsystems each with it's own cntlid ida.
Instead make cntlid ida globally unique and log the initial
association.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

nvmet: delete controllers deletion upon subsystem release

No reason for them to be kept around if we are
deleting the subsystem, so instead of passively
wait for the host to disconnect, actively delete
the controllers.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

nvmet: Fix possible infinite loop triggered on hot namespace removal

When removing a namespace we delete it from the subsystem namespaces
list with list_del_init which allows us to know if it is enabled or
not.

The problem is that list_del_init initialize the list next and does
not respect the RCU list-traversal we do on the IO path for locating
a namespace. Instead we need to use list_del_rcu which is allowed to
run concurrently with the _rcu list-traversal primitives (keeps list
next intact) and guarantees concurrent nvmet_find_naespace forward
progress.

By changing that, we cannot rely on ns->dev_link for knowing if the
namspace is enabled, so add enabled indicator entry to nvmet_ns for
that.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Solganik Alexander <sashas@lightbitslabs.com>
Cc: <stable@vger.kernel.org> # v4.8+

nvme: introduce struct nvme_request

This adds a shared per-request structure for all NVMe I/O. This structure
is embedded as the first member in all NVMe transport drivers request
private data and allows to implement common functionality between the
drivers.

The first use is to replace the current abuse of the SCSI command
passthrough fields in struct request for the NVMe command passthrough,
but it will grow a field more fields to allow implementing things
like common abort handlers in the future.

The passthrough commands are handled by having a pointer to the SQE
(struct nvme_command) in struct nvme_request, and the union of the
possible result fields, which had to be turned from an anonymous
into a named union for that purpose. This avoids having to pass
a reference to a full CQE around and thus makes checking the result
a lot more lightweight.

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

nvmet: Fix controller serial number inconsistency

The host is allowed to issue identify as many times
as it wants, we need to stay consistent when reporting
the serial number for a given controller.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>

nvmet: add a generic NVMe target

This patch introduces a implementation of NVMe subsystems,
controllers and discovery service which allows to export
NVMe namespaces across fabrics such as Ethernet, FC etc.

The implementation conforms to the NVMe 1.2.1 specification
and interoperates with NVMe over fabrics host implementations.

Configuration works using configfs, and is best performed using
the nvmetcli tool from http://git.infradead.org/users/hch/nvmetcli.git,
which also has a detailed explanation of the required steps in the
README file.

Signed-off-by: Armen Baloyan <armenx.baloyan@intel.com>
Signed-off-by: Anthony Knapp <anthony.j.knapp@intel.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: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jens Axboe <axboe@fb.com>