nvmet: implement unique discovery NQN

Unique discovery NQNs allow to differentiate between discovery
services from (typically physically separate) NVMe-oF subsystems.
This is required for establishing secured connections as otherwise
the credentials won't be unique and the integrity of the connection
cannot be guaranteed.
This patch adds a configfs attribute 'discovery_nqn' in the 'nvmet'
configfs directory to specify the unique discovery NQN.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

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 ctrl pi_support cap before initializing cap reg

This is a preparation for setting the maximal queue size of a controller
that supports PI.

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>

nvmet: add module description to stop warnings

Add MODULE_DESCRIPTION() in order to remove warnings & get clean build:-

WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/nvme/target/nvmet.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/nvme/target/nvme-loop.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/nvme/target/nvmet-rdma.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/nvme/target/nvmet-fc.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/nvme/target/nvme-fcloop.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/nvme/target/nvmet-tcp.o

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvmet: unify aer type enum

The host and target use two definition of aer type, unify
them into a single one.

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

nvmet: remove cntlid_min and cntlid_max check in nvmet_alloc_ctrl

The cntlid_min and cntlid_max are checked in configfs, don't check
again in nvmet_alloc_ctrl().

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

nvmet: avoid potential UAF in nvmet_req_complete()

An nvme target ->queue_response() operation implementation may free the
request passed as argument. Such implementation potentially could result
in a use after free of the request pointer when percpu_ref_put() is
called in nvmet_req_complete().

Avoid such problem by using a local variable to save the sq pointer
before calling __nvmet_req_complete(), thus avoiding dereferencing the
req pointer after that function call.

Fixes: a07b4970f464 ("nvmet: add a generic NVMe target")
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-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: use try_cmpxchg in nvmet_update_sq_head

Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old in
nvmet_update_sq_head. x86 CMPXCHG instruction returns success in ZF flag, so
this change saves a compare after cmpxchg (and related move instruction in
front of cmpxchg).

Also, try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg
fails. There is no need to re-read the value in the loop.

Note that the value from *ptr should be read using READ_ONCE to prevent
the compiler from merging, refetching or reordering the read.

No functional change intended.

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

nvmet: fix workqueue MEM_RECLAIM flushing dependency

The keep alive timer needs to stay on nvmet_wq, and not
modified to reschedule on the system_wq.

This fixes a warning:
------------[ cut here ]------------
workqueue: WQ_MEM_RECLAIM
nvmet-wq:nvmet_rdma_release_queue_work [nvmet_rdma] is flushing
!WQ_MEM_RECLAIM events:nvmet_keep_alive_timer [nvmet]
WARNING: CPU: 3 PID: 1086 at kernel/workqueue.c:2628
check_flush_dependency+0x16c/0x1e0

Reported-by: Yi Zhang <yi.zhang@redhat.com>
Fixes: 8832cf922151 ("nvmet: use a private workqueue instead of the system workqueue")
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

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: fix a use-after-free

Fix the following use-after-free complaint triggered by blktests nvme/004:

BUG: KASAN: user-memory-access in blk_mq_complete_request_remote+0xac/0x350
Read of size 4 at addr 0000607bd1835943 by task kworker/13:1/460
Workqueue: nvmet-wq nvme_loop_execute_work [nvme_loop]
Call Trace:
show_stack+0x52/0x58
dump_stack_lvl+0x49/0x5e
print_report.cold+0x36/0x1e2
kasan_report+0xb9/0xf0
__asan_load4+0x6b/0x80
blk_mq_complete_request_remote+0xac/0x350
nvme_loop_queue_response+0x1df/0x275 [nvme_loop]
__nvmet_req_complete+0x132/0x4f0 [nvmet]
nvmet_req_complete+0x15/0x40 [nvmet]
nvmet_execute_io_connect+0x18a/0x1f0 [nvmet]
nvme_loop_execute_work+0x20/0x30 [nvme_loop]
process_one_work+0x56e/0xa70
worker_thread+0x2d1/0x640
kthread+0x183/0x1c0
ret_from_fork+0x1f/0x30

Cc: stable@vger.kernel.org
Fixes: a07b4970f464 ("nvmet: add a generic NVMe target")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

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: remove redundant assignment after left shift

The left shift is followed by a re-assignment back to cc_css, the
assignment is redundant. Fix this by replacing the "<<=" operator with
"<<" instead.

This cleans up the clang scan build warning:

drivers/nvme/target/core.c:1124:10: warning: Although the value stored to 'cc_css' is used in the enclosing expression, the value is never actually read from 'cc_css' [deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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: replace ida_simple[get|remove] with the simler ida_[alloc|free]

ida_simple_[get|remove] are wrappers anyways.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: revert "nvmet: make discovery NQN configurable"

Revert commit 626851e9225d ("nvmet: make discovery NQN configurable");
the interface was deemed incorrect and will be replaced with a different
one.

Fixes: 626851e9225d ("nvmet: make discovery NQN configurable")
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: register discovery subsystem as 'current'

Register the discovery subsystem as the 'current' discovery subsystem,
and add a new discovery log page entry for it.

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: make discovery NQN configurable

TPAR8013 allows for unique discovery NQNs, so make the discovery
controller NQN configurable by exposing a subsys attribute
'discovery_nqn'.

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: avoid duplicate qid in connect cmd

According to the NVMe specification, if the host sends a Connect command
specifying a queue id which has already been created, a status value of
NVME_SC_CMD_SEQ_ERROR is returned.

Signed-off-by: Amit Engel <amit.engel@dell.com>
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: remove local variable

In function errno_to_nvme_status() we store the value of the NVMe
status into the local variable and don't do anything useful with that
but just return.

Remove the local variable and return the value directly from switch.
This also removed extra break statements.

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

nvmet: use nvme status value directly

There is no point in keeping the status variable that is used only once
in the function nvmet_async_events_failall().

Remove the variable and use the value directly.

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

nvmet: use u32 type for the local variable nsid

In function nvmet_max_nsid() we calculate the max nsid by iterating
over the XArray and store it in the variable nsid that has type of
unsigned long.

Since the value of this function is stored into the subsys->max_nsid
which is of type u32, change the local variable nsid type and the return
type of the same function to u32.

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

nvmet: allow mn change if subsys not discovered

Currently, once the subsystem's model_number is set for the first time
there is no way to change it. However, as long as no connection was
established to nvmf target, there is no reason for such restriction and
we should allow to change the subsystem's model_number as many times as
needed.

In addition, in order to simplfy the changes and make the model number
flow more similar to the rest of the attributes in the Identify
Controller data structure, we set a default value for the model number
at the initiation of the subsystem.

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: move ka_work initialization to nvmet_alloc_ctrl

Initialize keep-alive work only once, as part of alloc_ctrl
and not each time that nvmet_start_keep_alive_timer is being called

Signed-off-by: Amit Engel <amit.engel@dell.com>
Reviewed-by: Hou Pu <houpu.main@gmail.com>

nvmet: fix freeing unallocated p2pmem

In case p2p device was found but the p2p pool is empty, the nvme target
is still trying to free the sgl from the p2p pool instead of the
regular sgl pool and causing a crash (BUG() is called). Instead, assign
the p2p_dev for the request only if it was allocated from p2p pool.

This is the crash that was caused:

[Sun May 30 19:13:53 2021] ------------[ cut here ]------------
[Sun May 30 19:13:53 2021] kernel BUG at lib/genalloc.c:518!
[Sun May 30 19:13:53 2021] invalid opcode: 0000 [#1] SMP PTI
...
[Sun May 30 19:13:53 2021] kernel BUG at lib/genalloc.c:518!
...
[Sun May 30 19:13:53 2021] RIP: 0010:gen_pool_free_owner+0xa8/0xb0
...
[Sun May 30 19:13:53 2021] Call Trace:
[Sun May 30 19:13:53 2021] ------------[ cut here ]------------
[Sun May 30 19:13:53 2021] pci_free_p2pmem+0x2b/0x70
[Sun May 30 19:13:53 2021] pci_p2pmem_free_sgl+0x4f/0x80
[Sun May 30 19:13:53 2021] nvmet_req_free_sgls+0x1e/0x80 [nvmet]
[Sun May 30 19:13:53 2021] kernel BUG at lib/genalloc.c:518!
[Sun May 30 19:13:53 2021] nvmet_rdma_release_rsp+0x4e/0x1f0 [nvmet_rdma]
[Sun May 30 19:13:53 2021] nvmet_rdma_send_done+0x1c/0x60 [nvmet_rdma]

Fixes: c6e3f1339812 ("nvmet: add metadata support for block devices")
Reviewed-by: Israel Rukshin <israelr@nvidia.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.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 memory leak in nvmet_alloc_ctrl()

When creating ctrl in nvmet_alloc_ctrl(), if the cntlid_min is larger
than cntlid_max of the subsystem, and jumps to the
"out_free_changed_ns_list" label, but the ctrl->sqs lack of be freed.
Fix this by jumping to the "out_free_sqs" label.

Fixes: 94a39d61f80f ("nvmet: make ctrl-id configurable")
Signed-off-by: Wu Bo <wubo40@huawei.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.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: update error log page in nvmet_alloc_ctrl()

Instead of updating the error log page in the caller of the
nvmet_alloc_ctrt() update the error log page in the nvmet_alloc_ctrl().

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: remove a duplicate status assignment in nvmet_alloc_ctrl

In the function nvmet_alloc_ctrl() we assign status value before we
call nvmet_fine_get_subsys() to:

status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;

After we successfully find the subsystem we again set the status value
to:

status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;

Remove the duplicate status assignment value.

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: don't check iosqes,iocqes for discovery controllers

From the base spec, Figure 78:

"Controller Configuration, these fields are defined as parameters to
configure an "I/O Controller (IOC)" and not to configure a "Discovery
Controller (DC).

...
If the controller does not support I/O queues, then this field shall
be read-only with a value of 0h

Just perform this check for I/O controllers.

Fixes: a07b4970f464 ("nvmet: add a generic NVMe target")
Reported-by: Belanger, Martin <Martin.Belanger@dell.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
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: remove else at the end of the function

The function nvmet_parse_io_cmd() returns value from
nvmet_file_parse_io_cmd() or nvmet_bdev_parse_io_cmd() based on which
backend is set for the request. Remove the else and just return the
value from nvmet_bdev_parse_io_cmd().

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.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: 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: fix a NULL pointer dereference when tracing the flush command

When target side trace in turned on and flush command is issued from the
host it results in the following Oops.

[ 856.789724] BUG: kernel NULL pointer dereference, address: 0000000000000068
[ 856.790686] #PF: supervisor read access in kernel mode
[ 856.791262] #PF: error_code(0x0000) - not-present page
[ 856.791863] PGD 6d7110067 P4D 6d7110067 PUD 66f0ad067 PMD 0
[ 856.792527] Oops: 0000 [#1] SMP NOPTI
[ 856.792950] CPU: 15 PID: 7034 Comm: nvme Tainted: G OE 5.9.0nvme-5.9+ #71
[ 856.793790] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e3214
[ 856.794956] RIP: 0010:trace_event_raw_event_nvmet_req_init+0x13e/0x170 [nvmet]
[ 856.795734] Code: 41 5c 41 5d c3 31 d2 31 f6 e8 4e 9b b8 e0 e9 0e ff ff ff 49 8b 55 00 48 8b 38 8b 0
[ 856.797740] RSP: 0018:ffffc90001be3a60 EFLAGS: 00010246
[ 856.798375] RAX: 0000000000000000 RBX: ffff8887e7d2c01c RCX: 0000000000000000
[ 856.799234] RDX: 0000000000000020 RSI: 0000000057e70ea2 RDI: ffff8887e7d2c034
[ 856.800088] RBP: ffff88869f710578 R08: ffff888807500d40 R09: 00000000fffffffe
[ 856.800951] R10: 0000000064c66670 R11: 00000000ef955201 R12: ffff8887e7d2c034
[ 856.801807] R13: ffff88869f7105c8 R14: 0000000000000040 R15: ffff88869f710440
[ 856.802667] FS: 00007f6a22bd8780(0000) GS:ffff888813a00000(0000) knlGS:0000000000000000
[ 856.803635] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 856.804367] CR2: 0000000000000068 CR3: 00000006d73e0000 CR4: 00000000003506e0
[ 856.805283] Call Trace:
[ 856.805613] nvmet_req_init+0x27c/0x480 [nvmet]
[ 856.806200] nvme_loop_queue_rq+0xcb/0x1d0 [nvme_loop]
[ 856.806862] blk_mq_dispatch_rq_list+0x123/0x7b0
[ 856.807459] ? kvm_sched_clock_read+0x14/0x30
[ 856.808025] __blk_mq_sched_dispatch_requests+0xc7/0x170
[ 856.808708] blk_mq_sched_dispatch_requests+0x30/0x60
[ 856.809372] __blk_mq_run_hw_queue+0x70/0x100
[ 856.809935] __blk_mq_delay_run_hw_queue+0x156/0x170
[ 856.810574] blk_mq_run_hw_queue+0x86/0xe0
[ 856.811104] blk_mq_sched_insert_request+0xef/0x160
[ 856.811733] blk_execute_rq+0x69/0xc0
[ 856.812212] ? blk_mq_rq_ctx_init+0xd0/0x230
[ 856.812784] nvme_execute_passthru_rq+0x57/0x130 [nvme_core]
[ 856.813461] nvme_submit_user_cmd+0xeb/0x300 [nvme_core]
[ 856.814099] nvme_user_cmd.isra.82+0x11e/0x1a0 [nvme_core]
[ 856.814752] blkdev_ioctl+0x1dc/0x2c0
[ 856.815197] block_ioctl+0x3f/0x50
[ 856.815606] __x64_sys_ioctl+0x84/0xc0
[ 856.816074] do_syscall_64+0x33/0x40
[ 856.816533] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 856.817168] RIP: 0033:0x7f6a222ed107
[ 856.817617] Code: 44 00 00 48 8b 05 81 cd 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 8
[ 856.819901] RSP: 002b:00007ffca848f058 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[ 856.820846] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f6a222ed107
[ 856.821726] RDX: 00007ffca848f060 RSI: 00000000c0484e43 RDI: 0000000000000003
[ 856.822603] RBP: 0000000000000003 R08: 000000000000003f R09: 0000000000000005
[ 856.823478] R10: 00007ffca848ece0 R11: 0000000000000202 R12: 00007ffca84912d3
[ 856.824359] R13: 00007ffca848f4d0 R14: 0000000000000002 R15: 000000000067e900
[ 856.825236] Modules linked in: nvme_loop(OE) nvmet(OE) nvme_fabrics(OE) null_blk nvme(OE) nvme_corel

Move the nvmet_req_init() tracepoint after we parse the command in
nvmet_req_init() so that we can get rid of the duplicate
nvmet_find_namespace() call.
Rename __assign_disk_name() -> __assign_req_name(). Now that we call
tracepoint after parsing the command simplify the newly added
__assign_req_name() which fixes this bug.

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

nvmet: fix uninitialized work for zero kato

When connecting a controller with a zero kato value using the following
command line

nvme connect -t tcp -n NQN -a ADDR -s PORT --keep-alive-tmo=0

the warning below can be reproduced:

WARNING: CPU: 1 PID: 241 at kernel/workqueue.c:1627 __queue_delayed_work+0x6d/0x90
with trace:
mod_delayed_work_on+0x59/0x90
nvmet_update_cc+0xee/0x100 [nvmet]
nvmet_execute_prop_set+0x72/0x80 [nvmet]
nvmet_tcp_try_recv_pdu+0x2f7/0x770 [nvmet_tcp]
nvmet_tcp_io_work+0x63f/0xb2d [nvmet_tcp]
...

This is caused by queuing up an uninitialized work. Althrough the
keep-alive timer is disabled during allocating the controller (fixed in
0d3b6a8d213a), ka_work still has a chance to run (called by
nvmet_start_ctrl).

Fixes: 0d3b6a8d213a ("nvmet: Disable keep-alive timer when kato is cleared to 0h")
Signed-off-by: zhenwei pi <pizhenwei@bytedance.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>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

nvmet: Disable keep-alive timer when kato is cleared to 0h

Based on nvme spec, when keep alive timeout is set to zero
the keep-alive timer should be disabled.

Signed-off-by: Amit Engel <amit.engel@dell.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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>

block: remove the bd_queue field from struct block_device

Just use bd_disk->queue instead.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: fail outstanding host posted AEN req

In function nvmet_async_event_process() we only process AENs iff
there is an open slot on the ctrl->async_event_cmds[] && aen
event list posted by the target is not empty. This keeps host
posted AEN outstanding if target generated AEN list is empty.
We do cleanup the target generated entries from the aen list in
nvmet_ctrl_free()-> nvmet_async_events_free() but we don't
process AEN posted by the host. This leads to following problem :-

When processing admin sq at the time of nvmet_sq_destroy() holds
an extra percpu reference(atomic value = 1), so in the following code
path after switching to atomic rcu, release function (nvmet_sq_free())
is not getting called which blocks the sq->free_done in
nvmet_sq_destroy() :-

nvmet_sq_destroy()
percpu_ref_kill_and_confirm()
- __percpu_ref_switch_mode()
-- __percpu_ref_switch_to_atomic()
--- call_rcu() -> percpu_ref_switch_to_atomic_rcu()
---- /* calls switch callback */
- percpu_ref_put()
-- percpu_ref_put_many(ref, 1)
--- else if (unlikely(atomic_long_sub_and_test(nr, &ref->count)))
---- ref->release(ref); <---- Not called.

This results in indefinite hang:-

void nvmet_sq_destroy(struct nvmet_sq *sq)
...
if (ctrl && ctrl->sqs && ctrl->sqs[0] == sq) {
nvmet_async_events_process(ctrl, status);
percpu_ref_put(&sq->ref);
}
percpu_ref_kill_and_confirm(&sq->ref, nvmet_confirm_sq);
wait_for_completion(&sq->confirm_done);
wait_for_completion(&sq->free_done); <-- Hang here

Which breaks the further disconnect sequence. This problem seems to be
introduced after commit 64f5e9cdd711b ("nvmet: fix memory leak when
removing namespaces and controllers concurrently").

This patch processes ctrl->async_event_cmds[] in the admin sq destroy()
context irrespetive of aen_list. Also we get rid of the controller's
aen_list processing in the nvmet_sq_destroy() context and just ignore
ctrl->aen_list.

This results in nvmet_async_events_process() being called from workqueue
context so we adjust the code accordingly.

Fixes: 64f5e9cdd711 ("nvmet: fix memory leak when removing namespaces and controllers concurrently ")
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet: cleanups the loop in nvmet_async_events_process

Based-on-a-patch-by: Christoph Hellwig <hch@infradead.org>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: David Milburn <dmilburn@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: fix memory leak when removing namespaces and controllers concurrently

When removing a namespace, we add an NS_CHANGE async event, however if
the controller admin queue is removed after the event was added but not
yet processed, we won't free the aens, resulting in the below memory
leak [1].

Fix that by moving nvmet_async_event_free to the final controller
release after it is detached from subsys->ctrls ensuring no async
events are added, and modify it to simply remove all pending aens.

--
$ cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff888c1af2c000 (size 32):
comm "nvmetcli", pid 5164, jiffies 4295220864 (age 6829.924s)
hex dump (first 32 bytes):
28 01 82 3b 8b 88 ff ff 28 01 82 3b 8b 88 ff ff (..;....(..;....
02 00 04 65 76 65 6e 74 5f 66 69 6c 65 00 00 00 ...event_file...
backtrace:
[<00000000217ae580>] nvmet_add_async_event+0x57/0x290 [nvmet]
[<0000000012aa2ea9>] nvmet_ns_changed+0x206/0x300 [nvmet]
[<00000000bb3fd52e>] nvmet_ns_disable+0x367/0x4f0 [nvmet]
[<00000000e91ca9ec>] nvmet_ns_free+0x15/0x180 [nvmet]
[<00000000a15deb52>] config_item_release+0xf1/0x1c0
[<000000007e148432>] configfs_rmdir+0x555/0x7c0
[<00000000f4506ea6>] vfs_rmdir+0x142/0x3c0
[<0000000000acaaf0>] do_rmdir+0x2b2/0x340
[<0000000034d1aa52>] do_syscall_64+0xa5/0x4d0
[<00000000211f13bc>] entry_SYSCALL_64_after_hwframe+0x6a/0xdf

Fixes: a07b4970f464 ("nvmet: add a generic NVMe target")
Reported-by: David Milburn <dmilburn@redhat.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Tested-by: David Milburn <dmilburn@redhat.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: generate AEN for ns revalidate size change

The newly added function nvmet_ns_revalidate() does update the ns size
in the identify namespace in-core target data structure when host issues
id-ns command. This can lead to host having inconsistencies between size
of the namespace present in the id-ns command result and size of the
corresponding block device until host scans the namespaces explicitly.

To avoid this scenario generate AEN if old size is not same as the new
one in nvmet_ns_revalidate().

This will allow automatic AEN generation when host calls id-ns command
and also allows target to install userspace rules so that it can trigger
nvmet_ns_revalidate() (using configfs interface with the help of next
patch) resulting in appropriate AEN generation when underlying namespace
size change is detected.

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 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 async event tracing support

This adds a new tracepoint for the target to trace async event. This is
helpful in debugging and comparing host and target side async events
especially when host is connected to different targets on different
machines and now that we rely on userspace components to generate AEN. 

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

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: update AEN list and array at one place

All async events are enqueued via nvmet_add_async_event() which
updates the ctrl->async_event_cmds[] array and additionally an struct
nvmet_async_event is added to the ctrl->async_events list.

Under normal operations the nvmet_async_event_work() updates again
the ctrl->async_event_cmds and removes the corresponding struct
nvmet_async_event from the list again. Though nvmet_sq_destroy() could
be called which calls nvmet_async_events_free() which only updates the
ctrl->async_event_cmds[] array.

Add new functions nvmet_async_events_process() and
nvmet_async_events_free() to process async events, update an array and
the list.

When we destroy submission queue after clearing the aen present on
the ctrl->async list we also loop over ctrl->async_event_cmds[] for
any requests posted by the host for which we don't have the AEN in
the ctrl->async_events list by calling nvmet_async_event_process()
and nvmet_async_events_free().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
[chaitanya.kulkarni@wdc.com
* Loop over and clear out outstanding requests
* Update changelog
]
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: Pass lockdep expression to RCU lists

ctrl->subsys->namespaces and subsys->namespaces are traversed with
list_for_each_entry_rcu outside an RCU read-side critical section but
under the protection of ctrl->subsys->lock and subsys->lock respectively.

Hence, add the corresponding lockdep expression to the list traversal
primitive to silence false-positive lockdep warnings, and harden RCU
lists.

Reported-by: kbuild test robot <lkp@intel.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvmet: clean up command parsing a bit

Move the special cases for fabrics commands and the discovery controller
to nvmet_parse_admin_cmd in preparation for adding passthrough support.

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

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: add unlikely check at nvmet_req_alloc_sgl

The call to sgl_alloc shouldn't fail so add this simple optimization to
the fast path.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet-file: fix nvmet_file_flush() always returning an error

Presently, nvmet_file_flush() always returns a call to
errno_to_nvme_status() but that helper doesn't take into account the
case when errno=0. So nvmet_file_flush() always returns an error code.

All other callers of errno_to_nvme_status() check for success before
calling it.

To fix this, ensure errno_to_nvme_status() returns success if the
errno is zero. This should prevent future mistakes like this from
happening.

Fixes: c6aa3542e010 ("nvmet: add error log support for file backend")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>

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: introduce target-side trace

This patch introduces target-side request tracing. As Christoph
suggested, the trace would not be in a core or module to avoid
disadvantages like cache miss:
http://lists.infradead.org/pipermail/linux-nvme/2019-June/024721.html

The target-side trace code is entirely based on the Johannes's trace code
from the host side. It has lots of codes duplicated, but it would be
better than having advantages mentioned above.

It also traces not only fabrics commands, but also nvme normal commands.
Once the codes to be shared gets bigger, then we can make it common as
suggsted.

This also removed the create_sq and create_cq trace parsing functions
because it will be done by the connect fabrics command.

Example:
echo 1 > /sys/kernel/debug/tracing/event/nvmet/nvmet_req_init/enable
echo 1 > /sys/kernel/debug/tracing/event/nvmet/nvmet_req_complete/enable
cat /sys/kernel/debug/tracing/trace

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
[hch: fixed the symbol namespace and a an endianess conversion]
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme: introduce nvme_is_fabrics to check fabrics cmd

This patch introduces a nvme_is_fabrics() inline function to check
whether or not the given command structure is for fabrics.

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
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: include <linux/scatterlist.h>

Build breaks:

drivers/nvme/target/core.c: In function 'nvmet_req_alloc_sgl':
drivers/nvme/target/core.c:939:12: error: implicit declaration of \
function 'sgl_alloc'; did you mean 'bio_alloc'? \
[-Werror=implicit-function-declaration]
req->sg = sgl_alloc(req->transfer_len, GFP_KERNEL, &req->sg_cnt);
^~~~~~~~~
bio_alloc
drivers/nvme/target/core.c:939:10: warning: assignment makes pointer \
from integer without a cast [-Wint-conversion]
req->sg = sgl_alloc(req->transfer_len, GFP_KERNEL, &req->sg_cnt);
^
drivers/nvme/target/core.c: In function 'nvmet_req_free_sgl':
drivers/nvme/target/core.c:952:3: error: implicit declaration of \
function 'sgl_free'; did you mean 'ida_free'? [-Werror=implicit-function-declaration]
sgl_free(req->sg);
^~~~~~~~
ida_free

Cause:

1. missing include to <linux/scatterlist.h>
2. SGL_ALLOC needs to be enabled

Therefore adding the missing include, as well as Kconfig dependency.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Minwoo Im <minwoo.im@samsung.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: return a specified error it subsys_alloc fails

nvmet_subsys_alloc() returns its pointer or NULL if it fails. We can
see three different steps in this function:
1. memory allocation
2. argument check
3. memory allocation for string

But now the callers of this function do not seem to handle case 2 by
returning -ENOMEM only even if it fails with an invalid parameter.

This patch specifies error codes so that caller can pass it to its own
caller.

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>.
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: add safety check for subsystem lock during nvmet_ns_changed

we need to make sure that subsystem lock is taken during ctrl's list
traversing. nvmet_ns_changed function is not static and can be used from
various callers simultaneously.

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

nvmet: never fail double namespace enablement

In case we create N namespaces while N < NVMET_MAX_NAMESPACES, we can
perform "echo 1 > <nsid>/enable" as much as we want. In case N ==
NVMET_MAX_NAMESPACES we fail. Make sure we have the same flow for any N.

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

nvmet: fix error flow during ns enable

In case we fail to enable p2pmem on the current namespace, disable the
backing store device before exiting.

Cc: Stephen Bates <sbates@raithlin.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme-loop: init nvmet_ctrl fatal_err_work when allocate

After commit 4d43d395fe (workqueue: Try to catch flush_work() without
INIT_WORK()), it can cause warning when delete nvme-loop device, trace
like:

[ 76.601272] Call Trace:
[ 76.601646] ? del_timer+0x72/0xa0
[ 76.602156] __cancel_work_timer+0x1ae/0x270
[ 76.602791] cancel_work_sync+0x14/0x20
[ 76.603407] nvmet_ctrl_free+0x1b7/0x2f0 [nvmet]
[ 76.604091] ? free_percpu+0x168/0x300
[ 76.604652] nvmet_sq_destroy+0x106/0x240 [nvmet]
[ 76.605346] nvme_loop_destroy_admin_queue+0x30/0x60 [nvme_loop]
[ 76.606220] nvme_loop_shutdown_ctrl+0xc3/0xf0 [nvme_loop]
[ 76.607026] nvme_loop_delete_ctrl_host+0x19/0x30 [nvme_loop]
[ 76.607871] nvme_do_delete_ctrl+0x75/0xb0
[ 76.608477] nvme_sysfs_delete+0x7d/0xc0
[ 76.609057] dev_attr_store+0x24/0x40
[ 76.609603] sysfs_kf_write+0x4c/0x60
[ 76.610144] kernfs_fop_write+0x19a/0x260
[ 76.610742] __vfs_write+0x1c/0x60
[ 76.611246] vfs_write+0xfa/0x280
[ 76.611739] ksys_write+0x6e/0x120
[ 76.612238] __x64_sys_write+0x1e/0x30
[ 76.612787] do_syscall_64+0xbf/0x3a0
[ 76.613329] entry_SYSCALL_64_after_hwframe+0x44/0xa9

We fix it by moving fatal_err_work init to nvmet_alloc_ctrl(), which may
more reasonable.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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: fix comparison of a u16 with -1

Currently the u16 req->error_loc is being compared to -1 which
will always be false. Fix this by casting -1 to u16 to fix this.

Detected by clang:
warning: result of comparison of constant -1 with expression of
type 'u16' (aka 'unsigned short') is always false
[-Wtautological-constant-out-of-range-compare]

Fixes: 76574f37bf4c ("nvmet: add interface to update error-log page")
Signed-off-by: Colin Ian King <colin.king@canonical.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 error log support in the core

This patch adds the support to maintain error log page for the
nvmet-core.

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>

nvmet: use unlikely for req status check

This patch adds unlikely in the nvmet request completion path for the
status check in the low level function __nvmet_req_complete.
This is helpful in the scenario where host and target connection is
working smoothly.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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: 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: 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: don't try to add ns to p2p map unless it actually uses it

Even without CONFIG_P2PDMA this results in a error print:
nvmet: no peer-to-peer memory is available that's supported by rxe0 and /dev/nullb0

Fixes: c6925093d0b2 ("nvmet: Optionally use PCI P2P memory")
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
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: use strcmp() instead of strncmp() for subsystem lookup

strncmp() stops comparing when either the end of one of the first two arguments
is reached or when 'n' characters have been compared, whichever comes first.
That means that strncmp(s1, s2, n) is equivalent to strcmp(s1, s2) if n exceeds
the length of s1 or the length of s2. Since that is the case in
nvmet_find_get_subsys(), change strncmp() into strcmp(). This patch avoids that
the following warning is reported by smatch:

drivers/nvme/target/core.c:940:1 nvmet_find_get_subsys() error: strncmp() '"nqn.2014-08.org.nvmexpress.discovery"' too small (37 vs 223)

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvmet: free workqueue object if module init fails

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
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: only check for filebacking on -ENOTBLK

We only need to check for a file-backed namespace if
nvmet_bdev_ns_enable() returns -ENOTBLK. For any other error
it's pointless as the open() error will remain the same.

Fixes: d5eff33e ("nvmet: add simple file backed ns support")
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.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: reset keep alive timer in controller enable

Controllers that are not yet enabled should not really enforce keep alive
timeouts, but we still want to track a timeout and cleanup in case a host
died before it enabled the controller. Hence, simply reset the keep
alive timer when the controller is enabled.

Suggested-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
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>

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: remove duplicate NULL initialization for req->ns

Remove the duplicate NULL initialization for req->ns. req->ns is always
initialized to NULL in nvmet_req_init(), so there is no need to reset
it later on failures unless we have previously assigned a value to it.

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

nvmet: make a few error messages more generic

"nvmet_check_ctrl_status()" is called from admin-cmd.c along
with io-cmd.c, make the error message more generic.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
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: fix PSDT field check in command format

PSDT field section according to NVM_Express-1.3:
"This field specifies whether PRPs or SGLs are used for any data
transfer associated with the command. PRPs shall be used for all
Admin commands for NVMe over PCIe. SGLs shall be used for all Admin
and I/O commands for NVMe over Fabrics. This field shall be set to
01b for NVMe over Fabrics 1.0 implementations.

Suggested-by: Idan Burstein <idanb@mellanox.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>

nvmet: release a ns reference in nvmet_req_uninit if needed

nvmet_req_init looked up a namespace and took a reference on it (unless it
failed prior to that). If the request is uninitialized (in error cases) we
need to remove that reference in case it was taken, otherwise we leak
namespace reference when calling nvme_req_uninit.

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

nvmet: rearrange nvmet_ctrl_free()

Make it symmetric to nvmet_alloc_ctrl().

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

nvmet: fix error flow in nvmet_alloc_ctrl()

Remove the allocated id on error.

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

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: Change max_nsid in subsystem due to ns_disable if needed

In case we disable namespaces which has the nsid like
subsystem max_nsid we need to search for the next largest nsid
in this subsystem. If the subsystem don't has more namespaces
we set it to 0, else we take nsid from the last namespace in
namespaces list because the list is sorted while inserting.

Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Roy Shterman <roys@lightbitslabs.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
[hch: slight refactor]
Signed-off-by: Christoph Hellwig <hch@lst.de>

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>

nvme: fix sqhd reference when admin queue connect fails

Fix bug in sqhd patch.

It wasn't the sq that was at risk. In the case where the admin queue
connect command fails, the sq->size field is not set. Therefore, this
becomes a divide by zero error.

Add a quick check to bypass under this failure condition.

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

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>

nvme: add symbolic constants for CC identifiers

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

nvmet: fix the return error code of target if host is not allowed

nvmf target shall return NVME_SC_CONNECT_INVALID_HOST instead of
the gereal code INVALID_PARAM when the given host nqn is not allowed
to connect. Refer to the 2.2.1 section of the NVMe over Fabrics Spec.

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

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>

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: Fixed avoided printing nvmet: twice in error logs.

This patch avoids printing "nvmet:" twice in error logs as its already
coming through pr_fmt macro.

Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
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>

sched/headers: Prepare to use <linux/rcuupdate.h> instead of <linux/rculist.h> in <linux/sched.h>

We don't actually need the full rculist.h header in sched.h anymore,
we will be able to include the smaller rcupdate.h header instead.

But first update code that relied on the implicit header inclusion.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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: Call fatal_error from keep-alive timout expiration

We only need to call delete_ctrl once, so given that both
keep-alive timeout and any other fatal error can trigger it,
just make sure we only call delete_ctrl once.

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

nvmet: cancel fatal error and flush async work before free controller

Make sure they are not running and we can free the controller
safely.

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

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+

nvmet: Don't queue fatal error work if csts.cfs is set

In the transport, in case of an interal queue error like
error completion in rdma we trigger a fatal error. However,
multiple queues in the same controller can serr error completions
and we don't want to trigger fatal error work more than once.

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

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>

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>

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: fix return value check in nvmet_subsys_alloc()

In case of error, the function kstrndup() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check
should be replaced with NULL test.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by: Jay Freyensee <james_p_freyensee@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

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>