linux.git/include/linux/sunrpc, branch v6.8

Merge tag 'nfs-for-6.8-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

2024-01-11T00:13:57+00:00

Pull nfs client updates from Anna Schumaker:
 "New Features:
   - Always ask for type with READDIR
   - Remove nfs_writepage()

  Bugfixes:
   - Fix a suspicious RCU usage warning
   - Fix a blocklayoutdriver reference leak
   - Fix the block driver's calculation of layoutget size
   - Fix handling NFS4ERR_RETURNCONFLICT
   - Fix _xprt_switch_find_current_entry()
   - Fix v4.1 backchannel request timeouts
   - Don't add zero-length pnfs block devices
   - Use the parent cred in nfs_access_login_time()

  Cleanups:
   - A few improvements when dealing with referring calls from the
     server
   - Clean up various unused variables, struct fields, and function
     calls
   - Various tracepoint improvements"

* tag 'nfs-for-6.8-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (21 commits)
  NFSv4.1: Use the nfs_client's rpc timeouts for backchannel
  SUNRPC: Fixup v4.1 backchannel request timeouts
  rpc_pipefs: Replace one label in bl_resolve_deviceid()
  nfs: Remove writepage
  NFS: drop unused nfs_direct_req bytes_left
  pNFS: Fix the pnfs block driver's calculation of layoutget size
  nfs: print fileid in lookup tracepoints
  nfs: rename the nfs_async_rename_done tracepoint
  nfs: add new tracepoint at nfs4 revalidate entry point
  SUNRPC: fix _xprt_switch_find_current_entry logic
  NFSv4.1/pnfs: Ensure we handle the error NFS4ERR_RETURNCONFLICT
  NFSv4.1: if referring calls are complete, trust the stateid argument
  NFSv4: Track the number of referring calls in struct cb_process_state
  NFS: Use parent's objective cred in nfs_access_login_time()
  NFSv4: Always ask for type with READDIR
  pnfs/blocklayout: Don't add zero-length pnfs_block_dev
  blocklayoutdriver: Fix reference leak of pnfs_device_node
  SUNRPC: Fix a suspicious RCU usage warning
  SUNRPC: Create a helper function for accessing the rpc_clnt's xprt_switch
  SUNRPC: Remove unused function rpc_clnt_xprt_switch_put()
  ...

SUNRPC: discard sv_refcnt, and svc_get/svc_put

2024-01-07T22:54:33+00:00

sv_refcnt is no longer useful.
lockd and nfs-cb only ever have the svc active when there are a non-zero
number of threads, so sv_refcnt mirrors sv_nrthreads.

nfsd also keeps the svc active between when a socket is added and when
the first thread is started, but we don't really need a refcount for
that.  We can simply not destroy the svc while there are any permanent
sockets attached.

So remove sv_refcnt and the get/put functions.
Instead of a final call to svc_put(), call svc_destroy() instead.
This is changed to also store NULL in the passed-in pointer to make it
easier to avoid use-after-free situations.

Signed-off-by: NeilBrown 
Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever

svc: don't hold reference for poolstats, only mutex.

2024-01-07T22:54:33+00:00

A future patch will remove refcounting on svc_serv as it is of little
use.
It is currently used to keep the svc around while the pool_stats file is
open.
Change this to get the pointer, protected by the mutex, only in
seq_start, and the release the mutex in seq_stop.
This means that if the nfsd server is stopped and restarted while the
pool_stats file it open, then some pool stats info could be from the
first instance and some from the second.  This might appear odd, but is
unlikely to be a problem in practice.

Signed-off-by: NeilBrown 
Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever

svcrdma: Implement multi-stage Read completion again

2024-01-07T22:54:33+00:00

Having an nfsd thread waiting for an RDMA Read completion is
problematic if the Read responder (ie, the client) stops responding.
We need to go back to handling RDMA Reads by getting the svc scheduler
to call svc_rdma_recvfrom() a second time to finish building an RPC
message after a Read completion.

This is the final patch, and makes several changes that have to
happen concurrently:

1. svc_rdma_process_read_list no longer waits for a completion, but
   simply builds and posts the Read WRs.

2. svc_rdma_read_done() now queues a completed Read on
   sc_read_complete_q for later processing rather than calling
   complete().

3. The completed RPC message is no longer built in the
   svc_rdma_process_read_list() path. Finishing the message is now
   done in svc_rdma_recvfrom() when it notices work on the
   sc_read_complete_q. The "finish building this RPC message" code
   is removed from the svc_rdma_process_read_list() path.

This arrangement avoids the need for an nfsd thread to wait for an
RDMA Read non-interruptibly without a timeout. It's basically the
same code structure that Tom Tucker used for Read chunks along with
some clean-up and modernization.

Signed-off-by: Chuck Lever

svcrdma: Add back svcxprt_rdma::sc_read_complete_q

2024-01-07T22:54:32+00:00

Having an nfsd thread waiting for an RDMA Read completion is
problematic if the Read responder (ie, the client) stops responding.
We need to go back to handling RDMA Reads by allowing the nfsd
thread to return to the svc scheduler, then waking a second thread
finish the RPC message once the Read completion fires.

As a next step, add a list_head upon which completed Reads are queued.
A subsequent patch will make use of this queue.

Signed-off-by: Chuck Lever

svcrdma: Add back svc_rdma_recv_ctxt::rc_pages

2024-01-07T22:54:32+00:00

Having an nfsd thread waiting for an RDMA Read completion is
problematic if the Read responder (the client) stops responding. We
need to go back to handling RDMA Reads by allowing the nfsd thread
to return to the svc scheduler, then waking a second thread finish
the RPC message once the Read completion fires.

To start with, restore the rc_pages field so that RDMA Read pages
can be managed across calls to svc_rdma_recvfrom().

Signed-off-by: Chuck Lever

svcrdma: De-duplicate completion ID initialization helpers

2024-01-07T22:54:31+00:00

Signed-off-by: Chuck Lever

svcrdma: Move the svc_rdma_cc_init() call

2024-01-07T22:54:31+00:00

Now that the chunk_ctxt for Reads is no longer dynamically allocated
it can be initialized once for the life of the object that contains
it (struct svc_rdma_recv_ctxt).

Signed-off-by: Chuck Lever

svcrdma: Update synopsis of svc_rdma_build_read_segment()

2024-01-07T22:54:30+00:00

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

svcrdma: Move read_info::ri_pageoff into struct svc_rdma_recv_ctxt

2024-01-07T22:54:30+00:00

Further clean up: move the starting byte offset field into
svc_rdma_recv_ctxt.

Signed-off-by: Chuck Lever