The kbuild tst robot flagged the following 3 issues:

Case 1)
>> drivers/nvme/target/fc.c:1201:37: warning: Either the condition
>> '!assoc' is redundant or there is possible null pointer dereference:
>> assoc. [nullPointerRedundantCheck]
>>  struct nvmet_fc_tgtport *tgtport = assoc->tgtport;
                                       ^
>> drivers/nvme/target/fc.c:1853:7: note: Assuming that condition '!assoc'
>> is not redundant
>>   if (!assoc)
         ^
>> drivers/nvme/target/fc.c:1850:37: note: Assignment
>> 'assoc=nvmet_fc_find_target_assoc(tgtport,be64_to_cpu(
>>              rqst->associd.association_id))', assigned value is 0
>>   assoc = nvmet_fc_find_target_assoc(tgtport,
                                       ^
>> drivers/nvme/target/fc.c:1896:31: note: Calling function
>> 'nvmet_fc_delete_target_assoc', 1st argument 'assoc' value is 0
>>  nvmet_fc_delete_target_assoc(assoc);
                                 ^

The tool isn't smart enough to see that line 1854 sets a ret value which
thereafter causes the routine to exit. This occurs before any of the assoc
references, so it is not an issue. There are 2 more reportings of this
same failure.

To quiet the tool - rework the if test that does the exit to also
reference assoc.  No change in logic otherwise.

Case 2)
drivers/nvme/target/fc.c:1202:29: warning: The scope of the variable
'queue' can be reduced. [variableScope]
    struct nvmet_fc_tgt_queue *queue;
                               ^

The tool is requesting the variable be declared within the code block
that utilizes it. Ignoring this report as existing code style is fine.

Case 3)
drivers/nvme/target/fc.c:1137:16: warning: Variable 'needrandom' is
assigned a value that is never used. [unreadVariable]
       needrandom = true;
                  ^

Another parsing issue with the tool. Given that parens were not used
with the list_for_each_entry() check, it inadvertantly thinks the
break exited the outer while loop not the inner for loop.

This is not an error. But, added parens to the inner list_for_each_entry()
to quiet the tool and as it is better coding style.

-- james
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reported-by: Nkbuild test robot <lkp@intel.com>
CC: kbuild test robot <lkp@intel.com>
CC: Christoph Hellwig <hch@lst.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In order to save resource allocation and utilize the completion
locality in a better way (compared to SRQ per device that exist today),
allocate Shared Receive Queues (SRQs) per completion vector. Associate
each created QP/CQ with an appropriate SRQ according to the queue index.
This association will reduce the lock contention in the fast path
(compared to SRQ per device solution) and increase the locality in
memory buffers. Add new module parameter for SRQ size to adjust it
according to the expected load. User should make sure the size is >= 256
to avoid lack of resources. Also reduce the debug level of "last WQE
reached" event that is raised when a QP is using SRQ during destruction
process to relief the log.
Signed-off-by: NMax Gurtovoy <maxg@mellanox.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

nvme_alloc_ns_head() doesn't use the 'struct nvme_id_ns' parameter.
Remove it, and update caller accordingly.
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Various nvme commands use a zeroes based number of dwords field. Create
a helper function to convert byte lengths to this format.
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Now that common helpers exist, add the ability to Send an NVME LS Request
and to Abort an outstanding LS Request to the nvmet side of the driver.
Signed-off-by: NPaul Ely <paul.ely@broadcom.com>
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

As the nvmet layer does not have the concept of a remoteport object, which
can be used to identify the entity on the other end of the fabric that is
to receive an LS, the hosthandle was introduced.  The driver passes the
hosthandle, a value representative of the remote port, with a ls request
receive. The LS request will create the association.  The transport will
remember the hosthandle for the association, and if there is a need to
initiate a LS request to the remote port for the association, the
hosthandle will be used. When the driver loses connectivity with the
remote port, it needs to notify the transport that the hosthandle is no
longer valid, allowing the transport to terminate associations related to
the hosthandle.

This patch adds support to the driver for the hosthandle. The driver will
use the ndlp pointer of the remote port for the hosthandle in calls to
nvmet_fc_rcv_ls_req().  The discovery engine is updated to invalidate the
hosthandle whenever connectivity with the remote port is lost.
Signed-off-by: NPaul Ely <paul.ely@broadcom.com>
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Now that common helpers exist, add the ability to receive NVME LS requests
to the driver. New requests will be delivered to the transport by
nvme_fc_rcv_ls_req().

In order to complete the LS, add support for Send LS Response and send
LS response completion handling to the driver.
Signed-off-by: NPaul Ely <paul.ely@broadcom.com>
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Currently, the ability to send an NVME LS response is limited to the nvmet
(controller/target) side of the driver.  In preparation of both the nvme
and nvmet sides supporting Send LS Response, rework the existing send
ls_rsp and ls_rsp completion routines such that there is common code that
can be used by both sides.
Signed-off-by: NPaul Ely <paul.ely@broadcom.com>
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Send LS Abort support is needed when Send LS Request is supported.

Currently, the ability to abort an NVME LS request is limited to the nvme
(host) side of the driver.  In preparation of both the nvme and nvmet sides
supporting Send LS Abort, rework the existing ls_req abort routines such
that there is common code that can be used by both sides.

While refactoring it was seen the logic in the abort routine was incorrect.
It attempted to abort all NVME LS's on the indicated port. As such, the
routine was reworked to abort only the NVME LS request that was specified.
Signed-off-by: NPaul Ely <paul.ely@broadcom.com>
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Currently, the ability to send an NVME LS request is limited to the nvme
(host) side of the driver.  In preparation of both the nvme and nvmet sides
support Send LS Request, rework the existing send ls_req and ls_req
completion routines such that there is common code that can be used by
both sides.
Signed-off-by: NPaul Ely <paul.ely@broadcom.com>
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In preparation for supporting both intiator mode and target mode
receiving NVME LS's, commonize the existing NVME LS request receive
handling found in the base driver and in the nvmet side.

Using the original lpfc_nvmet_unsol_ls_event() and
lpfc_nvme_unsol_ls_buffer() routines as a templates, commonize the
reception of an NVME LS request. The common routine will validate the LS
request, that it was received from a logged-in node, and allocate a
lpfc_async_xchg_ctx that is used to manage the LS request. The role of
the port is then inspected to determine which handler is to receive the
LS - nvme or nvmet. As such, the nvmet handler is tied back in. A handler
is created in nvme and is stubbed out.
Signed-off-by: NPaul Ely <paul.ely@broadcom.com>
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The last step of commonization is to remove the 'T' suffix from
state and flag field definitions.  This is minor, but removes the
mental association that it solely applies to nvmet use.
Signed-off-by: NPaul Ely <paul.ely@broadcom.com>
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

To support FC-NVME-2 support (actually FC-NVME (rev 1) with Ammendment 1),
both the nvme (host) and nvmet (controller/target) sides will need to be
able to receive LS requests.  Currently, this support is in the nvmet side
only. To prepare for both sides supporting LS receive, rename
lpfc_nvmet_rcv_ctx to lpfc_async_xchg_ctx and commonize the definition.
Signed-off-by: NPaul Ely <paul.ely@broadcom.com>
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

A lot of files in lpfc include nvme headers, building up relationships that
require a file to change for its headers when there is no other change
necessary. It would be better to localize the nvme headers.

There is also no need for separate nvme (initiator) and nvmet (tgt)
header files.

Refactor the inclusion of nvme headers so that all nvme items are
included by lpfc_nvme.h

Merge lpfc_nvmet.h into lpfc_nvme.h so that there is a single header used
by both the nvme and nvmet sides. This prepares for structure sharing
between the two roles. Prep to add shared function prototypes for upcoming
shared routines.
Signed-off-by: NPaul Ely <paul.ely@broadcom.com>
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Add support for performing LS requests from target to host.
Include sending request from targetport, reception into host,
host sending ls rsp.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Currently nvmefc-loop only sends LS's from host to target.
Slightly rework data structures and routine names to reflect this
path. Allows a straight-forward conversion to be used by ls's
from target to host.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

As part of FC-NVME-2 (and ammendment on FC-NVME), the target is to
send a Disconnect LS after an association is terminated and any
exchanges for the association have been ABTS'd. The target is also
not to send the receipt to any Disconnect Association LS, received
to initiate the association termination or received while the
association is terminating, until the Disconnect LS has been transmit.

Add support for sending Disconnect Association LS after all I/O's
complete (which is after ABTS'd certainly). Utilizes the new LLDD
api to send ls requests.

There is no need to track the Disconnect LS response or to retry
after timeout. All spec requirements will have been met by waiting
for i/o completion to initiate the transmission.

Add support for tracking the reception of Disconnect Association
and defering the response transmission until after the Disconnect
Association LS has been transmit.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In preparation to add ls request support, rename the current ls_list,
which is RCV LS request only, to ls_rcv_list.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In preparation for sending LS requests for an association that
terminates, save and track the hosthandle that is part of the
LS's that are received to create associations.

Support consists of:
- Create a hostport structure that will be 1:1 mapped to a
  host port handle. The hostport structure is specific to
  a targetport.
- Whenever an association is created, create a host port for
  the hosthandle the Create Association LS was received from.
  There will be only 1 hostport structure created, with all
  associations that have the same hosthandle sharing the
  hostport structure.
- When the association is terminated, the hostport reference
  will be removed. After the last association for the host
  port is removed, the hostport will be deleted.
- Add support for the new nvmet_fc_invalidate_host() interface.
  In the past, the LLDD didn't notify loss of connectivity to
  host ports - the LLD would simply reject new requests and wait
  for the kato timeout to kill the association. Now, when host
  port connectivity is lost, the LLDD can notify the transport.
  The transport will initiate the termination of all associations
  for that host port. When the last association has been terminated
  and the hosthandle will no longer be referenced, the new
  host_release callback will be made to the lldd.
- For compatibility with prior behavior which didn't report the
  hosthandle:  the LLDD must set hosthandle to NULL. In these
  cases, not LS request will be made, and no host_release callbacks
  will be made either.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

While code reviewing saw a couple of items that can be cleaned up:
- In nvmet_fc_delete_target_queue(), the routine unlocks, then checks
  and relocks.  Reorganize to avoid the unlock/relock.
- In nvmet_fc_delete_target_queue(), there's a check on the disconnect
  state that is unnecessary as the routine validates the state before
  starting any action.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Add LS reception failure messages
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The nvme-fc host transport did not support the reception of a
FC-NVME LS. Reception is necessary to implement full compliance
with FC-NVME-2.

Populate the LS receive handler, and specifically the handling
of a Disconnect Association LS. The response to the LS, if it
matched a controller, must be sent after the aborts for any
I/O on any connection have been sent.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Given that both host and target now generate and receive LS's create
a single table definition for LS names. Each tranport half will have
a local version of the table.

Convert the target side transport to use the new common Create
Association LS validation routine.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Given that both host and target now generate and receive LS's create
a single table definition for LS names. Each tranport half will have
a local version of the table.

As Create Association LS is issued by both sides, and received by
both sides, create common routines to format the LS and to validate
the LS.

Convert the host side transport to use the new common Create
Association LS formatting routine.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Convert the assoc_active boolean flag to a bitop on the flags field.
The bit ops will provide atomicity.

To make this change, the flags field was converted to a long type,
which also affects the FCCTRL_TERMIO flag.  Both FCCTRL_TERMIO and
now ASSOC_ACTIVE flags are set/cleared by bit operations.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Ensure that when allocations are done, and the lldd options indicate
no private data is needed, that private pointers will be set to NULL
(catches driver error that forgot to set private data size).

Slightly reorg the allocations so that private data follows allocations
for LS request/response buffers. Ensures better alignments for the buffers
as well as the private pointer.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Current code uses NVME_FC_MAX_LS_BUFFER_SIZE (2KB) when allocating
buffers for LS requests and responses. This is considerable overkill
for what is actually defined.

Rework code to have unions for all possible requests and responses
and size based on the unions.  Remove NVME_FC_MAX_LS_BUFFER_SIZE.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Routines in the target will want to be used in the host as well.
Error definitions should now shared as both sides will process
requests and responses to requests.

Moved common declarations to new fc.h header kept in the host
subdirectory.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The current LLDD api has:
  nvme-fc: contains api for transport to do LS requests (and aborts of
    them). However, there is no interface for reception of LS's and sending
    responses for them.
  nvmet-fc: contains api for transport to do reception of LS's and sending
    of responses for them. However, there is no interface for doing LS
    requests.

Revise the api's so that both nvme-fc and nvmet-fc can send LS's, as well
as receiving LS's and sending their responses.

Change name of the rcv_ls_req struct to better reflect generic use as
a context to used to send an ls rsp. Specifically:
  nvmefc_tgt_ls_req -> nvmefc_ls_rsp
  nvmefc_tgt_ls_req.nvmet_fc_private -> nvmefc_ls_rsp.nvme_fc_private

Change nvmet_fc_rcv_ls_req() calling sequence to provide handle that
can be used by transport in later LS request sequences for an association.

nvme-fc nvmet_fc nvme_fcloop:
  Revise to adapt to changed names in api header.
  Change calling sequence to nvmet_fc_rcv_ls_req() for hosthandle.
  Add stubs for new interfaces:
    host/fc.c: nvme_fc_rcv_ls_req()
    target/fc.c: nvmet_fc_invalidate_host()

lpfc:
  Revise to adapt code to changed names in api header.
  Change calling sequence to nvmet_fc_rcv_ls_req() for hosthandle.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

A couple of minor changes occurred between 1.06 and 1.08:
- Addition of NVME_SR_RSP opcode
- change of SR_RSP status code 1 to Reserved
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Instead just call the CDROM layer functionality directly.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The name is only printed for a not registered bdi in writeback.  Use the
device name there as is more useful anyway for the unlike case that the
warning triggers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Merge the _node vs normal version and drop the superflous gfp_t argument.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Split out a new bdi_set_owner helper to set the owner, and move the policy
for creating the bdi name back into genhd.c, where it belongs.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

bdi_register_va is only used by super.c, which can't be modular.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

All external users of device_create_vargs are gone, so remove it and
open code it in the only caller.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

rename blk_mq_alloc_rq_maps to blk_mq_alloc_map_and_requests,
this function allocs both map and request, make function name align
with funtion.
Signed-off-by: NWeiping Zhang <zhangweiping@didiglobal.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

rename __blk_mq_alloc_rq_map to __blk_mq_alloc_map_and_request,
actually it alloc both map and request, make function name
align with function.
Signed-off-by: NWeiping Zhang <zhangweiping@didiglobal.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Alloc new map and request for new hardware queue when increse
hardware queue count. Before this patch, it will show a
warning for each new hardware queue, but it's not enough, these
hctx have no maps and reqeust, when a bio was mapped to these
hardware queue, it will trigger kernel panic when get request
from these hctx.

Test environment:
 * A NVMe disk supports 128 io queues
 * 96 cpus in system

A corner case can always trigger this panic, there are 96
io queues allocated for HCTX_TYPE_DEFAULT type, the corresponding kernel
log: nvme nvme0: 96/0/0 default/read/poll queues. Now we set nvme write
queues to 96, then nvme will alloc others(32) queues for read, but
blk_mq_update_nr_hw_queues does not alloc map and request for these new
added io queues. So when process read nvme disk, it will trigger kernel
panic when get request from these hardware context.

Reproduce script:

nr=$(expr `cat /sys/block/nvme0n1/device/queue_count` - 1)
echo $nr > /sys/module/nvme/parameters/write_queues
echo 1 > /sys/block/nvme0n1/device/reset_controller
dd if=/dev/nvme0n1 of=/dev/null bs=4K count=1

[ 8040.805626] ------------[ cut here ]------------
[ 8040.805627] WARNING: CPU: 82 PID: 12921 at block/blk-mq.c:2578 blk_mq_map_swqueue+0x2b6/0x2c0
[ 8040.805627] Modules linked in: nvme nvme_core nf_conntrack_netlink xt_addrtype br_netfilter overlay xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nft_counter nf_nat_tftp nf_conntrack_tftp nft_masq nf_tables_set nft_fib_inet nft_f
ib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack tun bridge nf_defrag_ipv6 nf_defrag_ipv4 stp llc ip6_tables ip_tables nft_compat rfkill ip_set nf_tables nfne
tlink sunrpc intel_rapl_msr intel_rapl_common skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass ipmi_ssif crct10dif_pclmul crc32_pclmul iTCO_wdt iTCO_vendor_support ghash_clmulni_intel intel_
cstate intel_uncore raid0 joydev intel_rapl_perf ipmi_si pcspkr mei_me ioatdma sg ipmi_devintf mei i2c_i801 dca lpc_ich ipmi_msghandler acpi_power_meter acpi_pad xfs libcrc32c sd_mod ast i2c_algo_bit drm_vram_helper drm_ttm_helper ttm d
rm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops
[ 8040.805637]  ahci drm i40e libahci crc32c_intel libata t10_pi wmi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: nvme_core]
[ 8040.805640] CPU: 82 PID: 12921 Comm: kworker/u194:2 Kdump: loaded Tainted: G        W         5.6.0-rc5.78317c+ #2
[ 8040.805640] Hardware name: Inspur SA5212M5/YZMB-00882-104, BIOS 4.0.9 08/27/2019
[ 8040.805641] Workqueue: nvme-reset-wq nvme_reset_work [nvme]
[ 8040.805642] RIP: 0010:blk_mq_map_swqueue+0x2b6/0x2c0
[ 8040.805643] Code: 00 00 00 00 00 41 83 c5 01 44 39 6d 50 77 b8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 8b bb 98 00 00 00 89 d6 e8 8c 81 03 00 eb 83 <0f> 0b e9 52 ff ff ff 0f 1f 00 0f 1f 44 00 00 41 57 48 89 f1 41 56
[ 8040.805643] RSP: 0018:ffffba590d2e7d48 EFLAGS: 00010246
[ 8040.805643] RAX: 0000000000000000 RBX: ffff9f013e1ba800 RCX: 000000000000003d
[ 8040.805644] RDX: ffff9f00ffff6000 RSI: 0000000000000003 RDI: ffff9ed200246d90
[ 8040.805644] RBP: ffff9f00f6a79860 R08: 0000000000000000 R09: 000000000000003d
[ 8040.805645] R10: 0000000000000001 R11: ffff9f0138c3d000 R12: ffff9f00fb3a9008
[ 8040.805645] R13: 000000000000007f R14: ffffffff96822660 R15: 000000000000005f
[ 8040.805645] FS:  0000000000000000(0000) GS:ffff9f013fa80000(0000) knlGS:0000000000000000
[ 8040.805646] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8040.805646] CR2: 00007f7f397fa6f8 CR3: 0000003d8240a002 CR4: 00000000007606e0
[ 8040.805647] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 8040.805647] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 8040.805647] PKRU: 55555554
[ 8040.805647] Call Trace:
[ 8040.805649]  blk_mq_update_nr_hw_queues+0x31b/0x390
[ 8040.805650]  nvme_reset_work+0xb4b/0xeab [nvme]
[ 8040.805651]  process_one_work+0x1a7/0x370
[ 8040.805652]  worker_thread+0x1c9/0x380
[ 8040.805653]  ? max_active_store+0x80/0x80
[ 8040.805655]  kthread+0x112/0x130
[ 8040.805656]  ? __kthread_parkme+0x70/0x70
[ 8040.805657]  ret_from_fork+0x35/0x40
[ 8040.805658] ---[ end trace b5f13b1e73ccb5d3 ]---
[ 8229.365135] BUG: kernel NULL pointer dereference, address: 0000000000000004
[ 8229.365165] #PF: supervisor read access in kernel mode
[ 8229.365178] #PF: error_code(0x0000) - not-present page
[ 8229.365191] PGD 0 P4D 0
[ 8229.365201] Oops: 0000 [#1] SMP PTI
[ 8229.365212] CPU: 77 PID: 13024 Comm: dd Kdump: loaded Tainted: G        W         5.6.0-rc5.78317c+ #2
[ 8229.365232] Hardware name: Inspur SA5212M5/YZMB-00882-104, BIOS 4.0.9 08/27/2019
[ 8229.365253] RIP: 0010:blk_mq_get_tag+0x227/0x250
[ 8229.365265] Code: 44 24 04 44 01 e0 48 8b 74 24 38 65 48 33 34 25 28 00 00 00 75 33 48 83 c4 40 5b 5d 41 5c 41 5d 41 5e c3 48 8d 68 10 4c 89 ef <44> 8b 60 04 48 89 ee e8 dd f9 ff ff 83 f8 ff 75 c8 e9 67 fe ff ff
[ 8229.365304] RSP: 0018:ffffba590e977970 EFLAGS: 00010246
[ 8229.365317] RAX: 0000000000000000 RBX: ffff9f00f6a79860 RCX: ffffba590e977998
[ 8229.365333] RDX: 0000000000000000 RSI: ffff9f012039b140 RDI: ffffba590e977a38
[ 8229.365349] RBP: 0000000000000010 R08: ffffda58ff94e190 R09: ffffda58ff94e198
[ 8229.365365] R10: 0000000000000011 R11: ffff9f00f6a79860 R12: 0000000000000000
[ 8229.365381] R13: ffffba590e977a38 R14: ffff9f012039b140 R15: 0000000000000001
[ 8229.365397] FS:  00007f481c230580(0000) GS:ffff9f013f940000(0000) knlGS:0000000000000000
[ 8229.365415] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8229.365428] CR2: 0000000000000004 CR3: 0000005f35e26004 CR4: 00000000007606e0
[ 8229.365444] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 8229.365460] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 8229.365476] PKRU: 55555554
[ 8229.365484] Call Trace:
[ 8229.365498]  ? finish_wait+0x80/0x80
[ 8229.365512]  blk_mq_get_request+0xcb/0x3f0
[ 8229.365525]  blk_mq_make_request+0x143/0x5d0
[ 8229.365538]  generic_make_request+0xcf/0x310
[ 8229.365553]  ? scan_shadow_nodes+0x30/0x30
[ 8229.365564]  submit_bio+0x3c/0x150
[ 8229.365576]  mpage_readpages+0x163/0x1a0
[ 8229.365588]  ? blkdev_direct_IO+0x490/0x490
[ 8229.365601]  read_pages+0x6b/0x190
[ 8229.365612]  __do_page_cache_readahead+0x1c1/0x1e0
[ 8229.365626]  ondemand_readahead+0x182/0x2f0
[ 8229.365639]  generic_file_buffered_read+0x590/0xab0
[ 8229.365655]  new_sync_read+0x12a/0x1c0
[ 8229.365666]  vfs_read+0x8a/0x140
[ 8229.365676]  ksys_read+0x59/0xd0
[ 8229.365688]  do_syscall_64+0x55/0x1d0
[ 8229.365700]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NWeiping Zhang <zhangweiping@didiglobal.com>
Tested-by: NWeiping Zhang <zhangweiping@didiglobal.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

blk_mq_realloc_tag_set_tags will update set->nr_hw_queues, so
save old set->nr_hw_queues before call this function.
Signed-off-by: NWeiping Zhang <zhangweiping@didiglobal.com>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>