Scheduling reset_work after a nvme subsystem reset is expected to fail
on pcie, but this also prevents potential handling the platform's pcie
services may provide that might successfully recovering the link without
re-enumeration. Such examples include AER, DPC, and power's EEH.

Provide a pci specific operation that safely initiates a subsystem
reset, and instead of scheduling reset work, read back the status
register to trigger a pcie read error.

Since this only affects pci, the other fabrics drivers subscribe to a
generic nvmf subsystem reset that is exactly the same as before. The
loop fabric doesn't use it because nvmet doesn't support setting that
property anyway.

And since we're using the magic NSSR value in two places now, provide a
symbolic define for it.

Reported-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

CDR/MORE/DNR fields are not belonging to SC in the NVMe spec, rename
them to NVME_STATUS_* to avoid confusion.

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

Combining both creates an ambiguous cleanup scenario for the caller if
an error is returned: does the device reference need to be dropped or
did the error occur before the device was initialized? If an error
occurs after the device is added, then the existing cleanup routines
will leak memory.

Furthermore, the nvme core is taking it upon itself to free the device's
kobj name under certain conditions rather than go through the core
device API. We shouldn't be peaking into these implementation details.

Split the device initialization from the addition to make it easier to
know the error handling actions, fix the existing memory leaks, and stop
the device layering violations.

Link: https://lore.kernel.org/linux-nvme/c4050a37-ecc9-462c-9772-65e25166f439@grimberg.me/
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Drivers must call nvme_uninit_ctrl after a successful nvme_init_ctrl.
Split the allocation side out to make the error handling boundary easier
to navigate. The nvme fc driver's error handling had different returns
in the error goto label's, which harm readability.

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

Pull NVMe updates and fixes from Keith:

"nvme updates for Linux 6.10

 - Fabrics connection retries (Daniel, Hannes)
 - Fabrics logging enhancements (Tokunori)
 - RDMA delete optimization (Sagi)"

* tag 'nvme-6.10-2024-05-14' of git://git.infradead.org/nvme:
  nvme-rdma, nvme-tcp: include max reconnects for reconnect logging
  nvmet-rdma: Avoid o(n^2) loop in delete_ctrl
  nvme: do not retry authentication failures
  nvme-fabrics: short-circuit reconnect retries
  nvme: return kernel error codes for admin queue connect
  nvmet: return DHCHAP status codes from nvmet_setup_auth()
  nvmet: lock config semaphore when accessing DH-HMAC-CHAP key

Returning a nvme status from nvme_tcp_setup_ctrl() indicates that the
association was established and we have received a status from the
controller; consequently we should honour the DNR bit. If not any future
reconnect attempts will just return the same error, so we can
short-circuit the reconnect attempts and fail the connection directly.

Signed-off-by: Hannes Reinecke <hare@suse.de>
[dwagner: - extended nvme_should_reconnect]
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Rename nvme_fc_nvme_ctrl_freed to nvme_fc_free_ctrl to match the name
pattern for the callback.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Log hostnqn when connecting to nvme target.
As hostnqn could be changed, logging this information
in syslog at appropriate time may help in troubleshooting.

Signed-off-by: Nitin U. Yewale <nyewale@redhat.com>
Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>

The module exit path has race between deleting all controllers and
freeing 'left over IDs'. To prevent double free a synchronization
between nvme_delete_ctrl and ida_destroy has been added by the initial
commit.

There is some logic around trying to prevent from hanging forever in
wait_for_completion, though it does not handling all cases. E.g.
blktests is able to reproduce the situation where the module unload
hangs forever.

If we completely rely on the cleanup code executed from the
nvme_delete_ctrl path, all IDs will be freed eventually. This makes
calling ida_destroy unnecessary. We only have to ensure that all
nvme_delete_ctrl code has been executed before we leave
nvme_fc_exit_module. This is done by flushing the nvme_delete_wq
workqueue.

While at it, remove the unused nvme_fc_wq workqueue too.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

The fc transport logs the opcode and fctype on command timeout.
This is sufficient information to identify the command issued,
but not very human-readable. Use the nvme_fabrics_opcode_str()
helper to also log the name of the command, as rdma and tcp already do.

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