Since the RDMA Read I/O state is now contained in the recv_ctxt,
svc_rdma_copy_inline_range() can use that recv_ctxt to derive the
read_info rather than the other way around. This removes another
usage of the ri_readctxt field, enabling its removal in a
subsequent patch.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Since the RDMA Read I/O state is now contained in the recv_ctxt,
svc_rdma_build_read_data_item() can use that recv_ctxt to derive
that information rather than the other way around. This removes
another usage of the ri_readctxt field, enabling its removal in a
subsequent patch.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Since the RDMA Read I/O state is now contained in the recv_ctxt,
svc_rdma_build_read_chunk_range() can use that recv_ctxt to derive
that information rather than the other way around. This removes
another usage of the ri_readctxt field, enabling its removal in a
subsequent patch.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Since the RDMA Read I/O state is now contained in the recv_ctxt,
svc_rdma_build_read_chunk() can use that recv_ctxt to derive that
information rather than the other way around. This removes another
usage of the ri_readctxt field, enabling its removal in a
subsequent patch.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Since the RDMA Read I/O state is now contained in the recv_ctxt,
svc_rdma_build_read_segment() can use the recv_ctxt to derive that
information rather than the other way around. This removes one usage
of the ri_readctxt field, enabling its removal in a subsequent
patch.

At the same time, the use of ri_rqst can similarly be replaced with
a passed-in function parameter.

Start with build_read_segment() because it is a common utility
function at the bottom of the Read chunk path.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Further clean up: move the starting byte offset field into
svc_rdma_recv_ctxt.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Further clean up: move the page index field into svc_rdma_recv_ctxt.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Since the request's svc_rdma_recv_ctxt will stay around for the
duration of the RDMA Read operation, the contents of struct
svc_rdma_read_info can reside in the request's svc_rdma_recv_ctxt
rather than being allocated separately. This will eventually save a
call to kmalloc() in a hot path.

Start this clean-up by moving the Read chunk's svc_rdma_chunk_ctxt.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Prepare for nestling these into the send and recv ctxts so they
no longer have to be allocated dynamically.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

In every instance, the pointer address in that field is now
available by other means.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Enable the eventual removal of the svc_rdma_chunk_ctxt::cc_rdma
field.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Enable the eventual removal of the svc_rdma_chunk_ctxt::cc_rdma
field.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Enable the eventual removal of the svc_rdma_chunk_ctxt::cc_rdma
field.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Enable the eventual removal of the svc_rdma_chunk_ctxt::cc_rdma
field.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Enable the removal of the svc_rdma_chunk_ctxt::cc_rdma field in a
subsequent patch.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

SG_CHUNK_SIZE is 128, making struct svc_rdma_rw_ctxt + the first
SGL array more than 4200 bytes in length, pushing the memory
allocation well into order 1.

Even so, the RDMA rw core doesn't seem to use more than max_send_sge
entries in that array (typically 32 or less), so that is all wasted
space.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

A send/recv_ctxt already records transport-related information
in the cq.id, thus there is no need to record the IP addresses of
the transport endpoints.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Update the DMA error flow tracepoints to report the completion ID of
the failing context. This ties the wait/failure to a particular
operation or request, which is more useful than knowing only the
failing transport.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Update the Send Queue's error flow tracepoints to report the
completion ID of the waiting or failing context. This ties the
wait/failure to a particular operation or request, which is a little
more useful than knowing only the transport that is about to close.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

De-duplicate some code, making it easier to add new tracepoints that
report only a completion ID.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Two svcrdma-related transport locks can become quite contended.
Collate their use and make them easy to find in /proc/lock_stat for
better observability.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

There's no need to protect llist_entry() with a spin lock.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

DMA unmapping can take quite some time, so it should not be handled
in a single-threaded completion handler. Defer releasing write_info
structs to the recently-added workqueue.

With this patch, DMA unmapping can be handled in parallel, and it
does not cause head-of-queue blocking of Write completions.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

DMA unmapping can take quite some time, so it should not be handled
in a single-threaded completion handler. Defer releasing send_ctxts
to the recently-added workqueue.

With this patch, DMA unmapping can be handled in parallel, and it
does not cause head-of-queue blocking of Send completions.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

To handle work in the background, set up an UNBOUND workqueue for
svcrdma. Subsequent patches will make use of it.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

The original reason for allocating svc_rdma_recv_ctxt objects during
Receive completion was to ensure the objects were allocated on the
NUMA node closest to the underlying IB device.

Since commit c5d68d25 ("svcrdma: Clean up allocation of
svc_rdma_recv_ctxt"), however, the device's favored node is
explicitly passed to the memory allocator.

To enable switching Receive completion to soft IRQ context, move
memory allocation out of completion handling, since it can be
costly, and it can sleep.

A limited number of objects is now allocated at "accept" time.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

The svc_rdma_recv_ctxt free list uses a lockless list to avoid the
need for a spin lock in the fast path. llist_del_first(), which is
used by svc_rdma_recv_ctxt_get(), requires serialization, however,
when there are multiple list producers that are unserialized.

I mistakenly thought there was only one caller of
svc_rdma_recv_ctxt_get() (svc_rdma_refresh_recvs()), thus explicit
serialization would not be necessary. But there is another caller:
svc_rdma_bc_sendto(), and these two are not serialized against each
other. I haven't seen ill effects that I could directly ascribe to
a lack of serialization. It's just an observation based on code
audit.

When DMA-mapping before sending a Reply, the passed-in struct
svc_rdma_recv_ctxt is used only for its write and reply PCLs. These
are currently always empty in the backchannel case. So, instead of
passing a full svc_rdma_recv_ctxt object to
svc_rdma_map_reply_msg(), let's pass in just the Write and Reply
PCLs.

This change makes it unnecessary for the backchannel to acquire a
dummy svc_rdma_recv_ctxt object when sending an RPC Call. The need
for svc_rdma_recv_ctxt free list serialization is now completely
avoided.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Callback operations enum is defined in client and server, move it to
common header file.
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Anna Schumaker <Anna.Schumaker@netapp.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

We check "state" for NULL on the previous line so it can't be NULL here.
No need to check again.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202312031425.LffZTarR-lkp@intel.com/Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

This flag is no longer used.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Avoid the use of an atomic bitop, and prepare for adding a run-time
switch for using splice reads.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

RQ_SPLICE_OK is a bit of a layering violation. Also, a subsequent
patch is going to provide a mechanism for always disabling splice
reads.

Splicing is an issue only for NFS READs, so refactor nfsd_read() to
check the auth type directly instead of relying on an rq_flag
setting.

The new helper will be added into the NFSv4 read path in a
subsequent patch.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD will use this new API to determine whether nfsd_splice_read is
safe to use. This avoids the need to add a dependency to NFSD for
CONFIG_SUNRPC_GSS.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Al Viro notes that normal system calls hold f_pos_lock when calling
->iterate_shared and ->llseek; however nfsd_readdir() does not take
that mutex when calling these methods.

It should be safe however because the struct file acquired by
nfsd_readdir() is not visible to other threads.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

This trace point was for debugging the DRC's garbage collection. In
the field it's just noise.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

workqueue: nfsd_file_delayed_close [nfsd] hogged CPU for >13333us 8
	times, consider switching to WQ_UNBOUND

There's no harm in closing a cached file descriptor on another core.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

The usage of read_seqbegin_or_lock() in nfsd_copy_write_verifier()
is wrong. "seq" is always even and thus "or_lock" has no effect,
this code can never take ->writeverf_lock for writing.

I guess this is fine, nfsd_copy_write_verifier() just copies 8 bytes
and nfsd_reset_write_verifier() is supposed to be very rare operation
so we do not need the adaptive locking in this case.

Yet the code looks wrong and sub-optimal, it can use read_seqbegin()
without changing the behaviour.

[ cel: Note also that it eliminates this Sparse warning:

fs/nfsd/nfssvc.c:360:6: warning: context imbalance in 'nfsd_copy_write_verifier' -
	different lock contexts for basic block

]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

We've had a number of attempts at different NFSv4 client tracking
methods over the years, but now nfsdcld has emerged as the clear winner
since the others (recoverydir and the usermodehelper upcall) are
problematic.

As a case in point, the recoverydir backend uses MD5 hashes to encode
long form clientid strings, which means that nfsd repeatedly gets dinged
on FIPS audits, since MD5 isn't considered secure. Its use of MD5 is not
cryptographically significant, so there is no danger there, but allowing
us to compile that out allows us to sidestep the issue entirely.

As a prelude to eventually removing support for these client tracking
methods, add a new Kconfig option that enables them. Mark it deprecated
and make it default to N.
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Pull i2c fixes from Wolfram Sang:
 "Improve the detection when to run atomic transfer handlers for kernels
  with preemption disabled. This removes some false positive splats a
  number of users were seeing if their driver didn't have support for
  atomic transfers.

  Also, fix a typo in the docs while we are here"

* tag 'i2c-for-6.7-final' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: core: Fix atomic xfer check for non-preempt config
  Documentation/i2c: fix spelling error in i2c-address-translators