Filesystems like XFS can implement atomic write I/O using either
REQ_ATOMIC flag set in the bio or via CoW operation. It will be useful
if we have a flag in trace events to distinguish between the two. This
patch adds char 'U' (Untorn writes) to rwbs field of the trace events
if REQ_ATOMIC flag is set in the bio.
<W/ REQ_ATOMIC>
=================
xfs_io-4238 [009] ..... 4148.126843: block_rq_issue: 259,0 WFSU 16384 () 768 + 32 none,0,0 [xfs_io]
<idle>-0 [009] d.h1. 4148.129864: block_rq_complete: 259,0 WFSU () 768 + 32 none,0,0 [0]
<W/O REQ_ATOMIC>
===============
xfs_io-4237 [010] ..... 4143.325616: block_rq_issue: 259,0 WS 16384 () 768 + 32 none,0,0 [xfs_io]
<idle>-0 [010] d.H1. 4143.329138: block_rq_complete: 259,0 WS () 768 + 32 none,0,0 [0]
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/44317cb2ec4588f6a2c1501a96684e6a1196e8ba.1747921498.git.ritesh.list@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
UBLK_F_AUTO_BUF_REG requires that the buffer registered automatically
is unregistered in same `io_ring_ctx`, so check it explicitly.
Document this requirement for UBLK_F_AUTO_BUF_REG.
Drop WARN_ON_ONCE() which is triggered from userspace code path.
Fixes: 99c1e4eb6a ("ublk: register buffer to local io_uring with provided buf index via UBLK_F_AUTO_BUF_REG")
Reported-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250522152043.399824-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add test for covering UBLK_AUTO_BUF_REG_FALLBACK:
- pass '--auto_zc_fallback' to null target, which requires both F_AUTO_BUF_REG
and F_SUPPORT_ZERO_COPY for handling UBLK_AUTO_BUF_REG_FALLBACK
- add ->buf_index() method for returning invalid buffer index to trigger
UBLK_AUTO_BUF_REG_FALLBACK
- add generic_09 for running the test
- add --auto_zc_fallback test in stress_03/stress_04/stress_05
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250520045455.515691-7-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Enable UBLK_F_AUTO_BUF_REG support for ublk utility by argument `--auto_zc`,
meantime support this feature in null, loop and stripe target code.
Add function test generic_08 for covering basic UBLK_F_AUTO_BUF_REG feature.
Also cover UBLK_F_AUTO_BUF_REG in stress_03, stress_04 and stress_05 test too.
'fio/t/io_uring -p0 /dev/ublkb0' shows that F_AUTO_BUF_REG can improve
IOPS by 50% compared with F_SUPPORT_ZERO_COPY in my test VM.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250520045455.515691-6-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For UBLK_F_AUTO_BUF_REG, buffer is registered to uring_cmd context
automatically with the provided buffer index. User may provide one wrong
buffer index, or the specified buffer is registered by application already.
Add UBLK_AUTO_BUF_REG_FALLBACK for supporting to auto buffer registering
fallback by completing the uring_cmd and telling ublk server the
register failure via UBLK_AUTO_BUF_REG_FALLBACK, then ublk server still
can register the buffer from userspace.
So we can provide reliable way for supporting auto buffer register.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250520045455.515691-5-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add UBLK_F_AUTO_BUF_REG for supporting to register buffer automatically
to local io_uring context with provided buffer index.
Add UAPI structure `struct ublk_auto_buf_reg` for holding user parameter
to register request buffer automatically, one 'flags' field is defined, and
there is still 32bit available for future extension, such as, adding one
io_ring FD field for registering buffer to external io_uring.
`struct ublk_auto_buf_reg` is populated from ublk uring_cmd's sqe->addr,
and all existing ublk commands are data-less, so it is just fine to reuse
sqe->addr for this purpose.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250520045455.515691-4-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
UBLK_F_SUPPORT_ZERO_COPY requires ublk server to issue explicit buffer
register/unregister uring_cmd for each IO, this way is not only inefficient,
but also introduce dependency between buffer consumer and buffer register/
unregister uring_cmd, please see tools/testing/selftests/ublk/stripe.c
in which backing file IO has to be issued one by one by IOSQE_IO_LINK.
Prepare for adding feature UBLK_F_AUTO_BUF_REG for addressing the existing
zero copy limitation:
- register request buffer automatically to ublk uring_cmd's io_uring
context before delivering io command to ublk server
- unregister request buffer automatically from the ublk uring_cmd's
io_uring context when completing the request
- io_uring will unregister the buffer automatically when uring is
exiting, so we needn't worry about accident exit
For using this feature, ublk server has to create one sparse buffer table
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250520045455.515691-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull NVMe updates from Christoph:
"nvme updates for Linux 6.16
- add per-node DMA pools and use them for PRP/SGL allocations
(Caleb Sander Mateos, Keith Busch)
- nvme-fcloop refcounting fixes (Daniel Wagner)
- support delayed removal of the multipath node and optionally support
the multipath node for private namespaces (Nilay Shroff)
- support shared CQs in the PCI endpoint target code (Wilfred Mallawa)
- support admin-queue only authentication (Hannes Reinecke)
- use the crc32c library instead of the crypto API (Eric Biggers)
- misc cleanups (Christoph Hellwig, Marcelo Moreira, Hannes Reinecke,
Leon Romanovsky, Gustavo A. R. Silva)"
* tag 'nvme-6.16-2025-05-20' of git://git.infradead.org/nvme: (42 commits)
nvme: rename nvme_mpath_shutdown_disk to nvme_mpath_remove_disk
nvme: introduce multipath_always_on module param
nvme-multipath: introduce delayed removal of the multipath head node
nvme-pci: derive and better document max segments limits
nvme-pci: use struct_size for allocation struct nvme_dev
nvme-pci: add a symolic name for the small pool size
nvme-pci: use a better encoding for small prp pool allocations
nvme-pci: rename the descriptor pools
nvme-pci: remove struct nvme_descriptor
nvme-pci: store aborted state in flags variable
nvme-pci: don't try to use SGLs for metadata on the admin queue
nvme-pci: make PRP list DMA pools per-NUMA-node
nvme-pci: factor out a nvme_init_hctx_common() helper
dmapool: add NUMA affinity support
nvme-fc: do not reference lsrsp after failure
nvmet-fcloop: don't wait for lport cleanup
nvmet-fcloop: add missing fcloop_callback_host_done
nvmet-fc: take tgtport refs for portentry
nvmet-fc: free pending reqs on tgtport unregister
nvmet-fcloop: drop response if targetport is gone
...
In the NVMe context, the term "shutdown" has a specific technical
meaning. To avoid confusion, this commit renames the nvme_mpath_
shutdown_disk function to nvme_mpath_remove_disk to better reflect
its purpose (i.e. removing the disk from the system). However,
nvme_mpath_remove_disk was already in use, and its functionality
is related to releasing or putting the head node disk. To resolve
this naming conflict and improve clarity, the existing nvme_mpath_
remove_disk function is also renamed to nvme_mpath_put_disk.
This renaming improves code readability and better aligns function
names with their actual roles.
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Currently, a multipath head disk node is not created for single-
ported NVMe adapters or private namespaces with non-unique NSID.
However, creating a head node in these cases can help transparently
handle transient PCIe link failures. Without a head node, features
like delayed removal cannot be leveraged, making it difficult to
tolerate such link failures. To address this, this commit introduces
nvme_core module parameter multipath_always_on.
When multipath_always_on is set to true, it forces the creation of a
multipath head node regardless NVMe disk or namespace type. So this
option allows the use of delayed removal of head node functionality
even for single-ported NVMe disks and private namespaces with a unique
NSID and thus helps transparently handle transient PCIe link failures.
By default multipath_always_on is set to false, thus preserving the
existing behavior. Setting it to true enables improved fault tolerance
in PCIe setups. Moreover, please note that enabling this option would
also implicitly enable nvme_core.multipath.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Currently, the multipath head node of an NVMe disk is removed
immediately as soon as all paths of the disk are removed. However,
this can cause issues in scenarios where:
- The disk hot-removal followed by re-addition.
- Transient PCIe link failures that trigger re-enumeration,
temporarily removing and then restoring the disk.
In these cases, removing the head node prematurely may lead to a head
disk node name change upon re-addition, requiring applications to
reopen their handles if they were performing I/O during the failure.
To address this, introduce a delayed removal mechanism of head disk
node. During transient failure, instead of immediate removal of head
disk node, the system waits for a configurable timeout, allowing the
disk to recover.
During transient disk failure, if application sends any IO then we
queue it instead of failing such IO immediately. If the disk comes back
online within the timeout, the queued IOs are resubmitted to the disk
ensuring seamless operation. In case disk couldn't recover from the
failure then queued IOs are failed to its completion and application
receives the error.
So this way, if disk comes back online within the configured period,
the head node remains unchanged, ensuring uninterrupted workloads
without requiring applications to reopen device handles.
A new sysfs attribute, named "delayed_removal_secs" is added under head
disk blkdev for user who wish to configure time for the delayed removal
of head disk node. The default value of this attribute is set to zero
second ensuring no behavior change unless explicitly configured.
Link: https://lore.kernel.org/linux-nvme/Y9oGTKCFlOscbPc2@infradead.org/
Link: https://lore.kernel.org/linux-nvme/Y+1aKcQgbskA2tra@kbusch-mbp.dhcp.thefacebook.com/
Suggested-by: Keith Busch <kbusch@kernel.org>
Suggested-by: Christoph Hellwig <hch@infradead.org>
[nilay: reworked based on the original idea/POC from Christoph and Keith]
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Redefine the max segments and max integrity limits based on the limiting
factors. This keeps exactly the same values for 4k PAGE_SIZE systems,
but increases the number of segments for larger page size as it properly
derives the scatterlist allocation based limit for them instead of
assuming a 4k PAGE_SIZE.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Open coding magic numbers in multiple places is never a good idea.
Signed-off-by: Leon Romanovsky <leon@kernel.org>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Add a separate flag to encode that the transfer is using the small
page sized pool, and use a normal 0..n count for the number of
descriptors.
Contains improvements and suggestions from Kanchan Joshi
<joshi.k@samsung.com> and Leon Romanovsky <leon@kernel.org>.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Leon Romanovsky <leon@kernel.org>
They are used for both PRPs and SGLs, and we use descriptor elsewhere
when referring to their allocations, so use that name here as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Leon Romanovsky <leon@kernel.org>
There is no real point in having a union of two pointer types here, just
use a void pointer as we mix and match types between the arms of the
union between the allocation and freeing side already.
Also rename the nr_allocations field to nr_descriptors to better describe
what it does.
Signed-off-by: Christoph Hellwig <hch@lst.de>
[leon: ported forward to include metadata SGL support]
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Instead of keeping dedicated "bool aborted" variable, switch to a flags
flags that can be used for other flags as well.
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
No admin command defined in an NVMe specification supports metadata,
but to protect against vendor specific commands using metadata ensure
that we don't try to use SGLs for metadata on the admin queue, as NVMe
does not support SGLs on the admin queue for the PCI transport. Do
this by checking if the data transfer has been setup using SGLs as
that is required for using SGLs for metadata.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Leon Romanovsky <leon@kernel.org>
NVMe commands with over 8 KB of discontiguous data allocate PRP list
pages from the per-nvme_device dma_pool prp_page_pool or prp_small_pool.
Each call to dma_pool_alloc() and dma_pool_free() takes the per-dma_pool
spinlock. These device-global spinlocks are a significant source of
contention when many CPUs are submitting to the same NVMe devices. On a
workload issuing 32 KB reads from 16 CPUs (8 hypertwin pairs) across 2
NUMA nodes to 23 NVMe devices, we observed 2.4% of CPU time spent in
_raw_spin_lock_irqsave called from dma_pool_alloc and dma_pool_free.
Ideally, the dma_pools would be per-hctx to minimize contention. But
that could impose considerable resource costs in a system with many NVMe
devices and CPUs.
As a compromise, allocate per-NUMA-node PRP list DMA pools. Map each
nvme_queue to the set of DMA pools corresponding to its device and its
hctx's NUMA node. This reduces the _raw_spin_lock_irqsave overhead by
about half, to 1.2%. Preventing the sharing of PRP list pages across
NUMA nodes also makes them cheaper to initialize.
Link: https://lore.kernel.org/linux-nvme/CADUfDZqa=OOTtTTznXRDmBQo1WrFcDw1hBA7XwM7hzJ-hpckcA@mail.gmail.com/T/#u
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
nvme_init_hctx() and nvme_admin_init_hctx() are very similar. In
preparation for adding more logic, factor out a nvme_init_hctx-common()
helper.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Introduce dma_pool_create_node(), like dma_pool_create() but taking an
additional NUMA node argument. Allocate struct dma_pool on the desired
node, and store the node on dma_pool for allocating struct dma_page.
Make dma_pool_create() an alias for dma_pool_create_node() with node set
to NUMA_NO_NODE.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The lsrsp object is maintained by the LLDD. The lifetime of the lsrsp
object is implicit. Because there is no explicit cleanup/free call into
the LLDD, it is not safe to assume after xml_rsp_fails, that the lsrsp
is still valid. The LLDD could have freed the object already.
With the recent changes how fcloop tracks the resources, this is the
case. Thus don't access lsrsp after xml_rsp_fails.
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The lifetime of the fcloop_lsreq is not tight to the lifetime of the
host or target port, thus there is no need anymore to synchronize the
cleanup path anymore.
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Add the missing fcloop_call_host_done calls so that the caller
frees resources when something goes wrong.
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Ensure that the tgtport is not going away as long portentry has a
pointer on it.
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
When nvmet_fc_unregister_targetport is called by the LLDD, it's not
possible to communicate with the host, thus all pending request will not
be process. Thus explicitly free them.
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
When the target port is gone, the lsrsp pointer is invalid. Thus don't
call the done function anymore instead just drop the response.
This happens when the target sends a disconnect association. After this
the target starts tearing down all resources and doesn't expect any
response.
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
fcloop depends on the host or the target to allocate the fcloop_lsreq
object. This means that the lifetime of the fcloop_lsreq is tied to
either the host or the target. Consequently, the host or the target must
cooperate during shutdown.
Unfortunately, this approach does not work well when the target forces a
shutdown, as there are dependencies that are difficult to resolve in a
clean way.
The simplest solution is to decouple the lifetime of the fcloop_lsreq
object by managing them directly within fcloop. Since this is not a
performance-critical path and only a small number of LS objects are used
during setup and cleanup, it does not significantly impact performance
to allocate them during normal operation.
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The delete callback can be called either via the unregister function or
from the transport directly. Thus it is necessary ensure resources are
not freed multiple times.
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The abort handling logic expects that the state and the fcpreq are only
accessed when holding the reqlock lock.
While at it, only handle the aborts in the abort handler.
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Track the lifetime of the in-flight tfcp_req to ensure
the object is not freed too early.
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Use the newly introduced fcloop_lport_lookup instead
of the open coded version.
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The checks for a valid input values are mixed with the logic to insert a
newly allocated nport. Refactor the function so that first the checks
are done.
This allows to untangle the setup steps into a more linear form which
reduces the complexity of the functions.
Also start tracking lport when a lport is assigned to a nport. This
ensures, that the lport is not going away as long it is still referenced
by a nport.
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The nport object has an association with the rport and lport object,
that means we can only remove an nport object from the global nport_list
after the last user of an rport or lport is gone.
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
A nport object is always used in association with targerport,
remoteport, tport and rport objects. Add explicit references for any of
the associated object. This ensures that nport is not removed too early
on shutdown sequences.
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Use SHASH_DESC_ON_STACK to avoid explicit allocation.
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Use SHASH_DESC_ON_STACK to avoid explicit allocation.
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Now that a submission queue holds a reference to its completion queue,
there is no need to pass the cq argument to nvmet_req_init(), so remove
it.
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The NVMe PCI transport specification allows for completion queues to be
shared by different submission queues.
This patch allows a submission queue to keep track of the completion queue
it is using with reference counting. As such, it can be ensured that a
completion queue is not deleted while a submission queue is actively
using it.
This patch enables completion queue sharing in the pci-epf target driver.
For fabrics drivers, completion queue sharing is not enabled as it is
not possible as per the fabrics specification. However, this patch
modifies the fabrics drivers to correctly integrate the new API that
supports completion queue sharing.
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
With struct nvmet_cq now having a reference count, this patch amends the
target fabrics call chain to initialize and destroy/put a completion
queue.
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
For the PCI transport, the NVMe specification allows submission queues
to share completion queues, however, this is not supported in the
current NVMe target implementation. This is a preparatory patch to allow
for completion queue (CQ) sharing between different submission queues
(SQ).
To support queue sharing, reference counting completion queues is
required. This patch adds the refcount_t field ref to struct nvmet_cq
coupled with respective nvmet_cq_init(), nvmet_cq_get(), nvmet_cq_put(),
nvmet_cq_is_deletable() and nvmet_cq_destroy() functions.
A CQ reference count is initialized with nvmet_cq_init() when a CQ is
created. Using nvmet_cq_get(), a reference to a CQ is taken when an SQ is
created that uses the respective CQ. Similarly. when an SQ is destroyed,
the reference count to the respective CQ from the SQ being destroyed is
decremented with nvmet_cq_put(). The last reference to a CQ is dropped
on a CQ deletion using nvmet_cq_put(), which invokes nvmet_cq_destroy()
to fully cleanup after the CQ. The helper function nvmet_cq_in_use() is
used to determine if any SQs are still using the CQ pending deletion.
In which case, the CQ must not be deleted. This should protect scenarios
where a bad host may attempt to delete a CQ without first having deleted
SQ(s) using that CQ.
Additionally, this patch adds an array of struct nvmet_cq to the
nvmet_ctrl structure. This allows for the controller to keep track of CQs
as they are created and destroyed, similar to the current tracking done
for SQs. The memory for this array is freed when the controller is freed.
A struct nvmet_ctrl reference is also added to the nvmet_cq structure to
allow for CQs to be removed from the controller whilst keeping the new
API similar to the existing API for SQs.
Sample callchain with CQ refcounting for the PCI endpoint target
(pci-epf):
i. nvmet_execute_create_cq -> nvmet_pci_epf_create_cq
-> nvmet_cq_create -> nvmet_cq_init [cq refcount=1]
ii. nvmet_execute_create_sq -> nvmet_pci_epf_create_sq
-> nvmet_sq_create -> nvmet_sq_init -> nvmet_cq_get [cq refcount=2]
iii. nvmet_execute_delete_sq - > nvmet_pci_epf_delete_sq ->
-> nvmet_sq_destroy -> nvmet_cq_put [cq refcount 1]
iv. nvmet_execute_delete_cq -> nvmet_pci_epf_delete_cq
-> nvmet_cq_put [cq refcount 0]
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This patch adds a new helper function nvmet_check_io_cqid(). It is to be
used when parsing host commands for IO CQ creation/deletion and IO SQ
creation to ensure that the specified IO completion queue identifier
(CQID) is not 0 (Admin queue ID). This is a check that already occurs in
the nvmet_execute_x() functions prior to nvmet_check_cqid.
With the addition of this helper function, the CQ ID checks in the
nvmet_execute_x() function can be removed, and instead simply call
nvmet_check_io_cqid() in place of nvmet_check_cqid().
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Do not start authentication on I/O queues as it doesn't really add value,
and secure concatenation disallows it anyway. Authentication commands on
I/O queues are not aborted, so the host may still run the authentication
protocol on I/O queues.
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
When sending 'connect' the queues can figure out from the return code
whether authentication is required or not. But reauthentication doesn't
disconnect the queues, so this check is not available. Rather we need
to check whether the queue had been authenticated initially to figure
out if we need to reauthenticate.
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
