linux-toradex.git/net/sunrpc/xprtrdma, branch v5.18-rc5

Merge tag 'nfsd-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

2022-04-13T00:23:19+00:00

Pull nfsd fixes from Chuck Lever:

 - Fix a write performance regression

 - Fix crashes during request deferral on RDMA transports

* tag 'nfsd-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  SUNRPC: Fix the svc_deferred_event trace class
  SUNRPC: Fix NFSD's request deferral on RDMA transports
  nfsd: Clean up nfsd_file_put()
  nfsd: Fix a write performance regression
  SUNRPC: Return true/false (not 1/0) from bool functions

SUNRPC: Fix NFSD's request deferral on RDMA transports

2022-04-06T18:01:27+00:00

Trond Myklebust reports an NFSD crash in svc_rdma_sendto(). Further
investigation shows that the crash occurred while NFSD was handling
a deferred request.

This patch addresses two inter-related issues that prevent request
deferral from working correctly for RPC/RDMA requests:

1. Prevent the crash by ensuring that the original
   svc_rqst::rq_xprt_ctxt value is available when the request is
   revisited. Otherwise svc_rdma_sendto() does not have a Receive
   context available with which to construct its reply.

2. Possibly since before commit 71641d99ce03 ("svcrdma: Properly
   compute .len and .buflen for received RPC Calls"),
   svc_rdma_recvfrom() did not include the transport header in the
   returned xdr_buf. There should have been no need for svc_defer()
   and friends to save and restore that header, as of that commit.
   This issue is addressed in a backport-friendly way by simply
   having svc_rdma_recvfrom() set rq_xprt_hlen to zero
   unconditionally, just as svc_tcp_recvfrom() does. This enables
   svc_deferred_recv() to correctly reconstruct an RPC message
   received via RPC/RDMA.

Reported-by: Trond Myklebust 
Link: https://lore.kernel.org/linux-nfs/82662b7190f26fb304eb0ab1bb04279072439d4e.camel@hammerspace.com/
Signed-off-by: Chuck Lever 
Cc:

Merge tag 'nfs-for-5.18-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

2022-03-30T01:55:37+00:00

Pull NFS client updates from Trond Myklebust:
"Highlights include:

Features:

- Switch NFS to use readahead instead of the obsolete readpages.

- Readdir fixes to improve cacheability of large directories when
there are multiple readers and writers.

- Readdir performance improvements when doing a seekdir() immediately
after opening the directory (common when re-exporting NFS).

- NFS swap improvements from Neil Brown.

- Loosen up memory allocation to permit direct reclaim and write back
in cases where there is no danger of deadlocking the writeback code
or NFS swap.

- Avoid sillyrename when the NFSv4 server claims to support the
necessary features to recover the unlinked but open file after
reboot.

Bugfixes:

- Patch from Olga to add a mount option to control NFSv4.1 session
trunking discovery, and default it to being off.

- Fix a lockup in nfs_do_recoalesce().

- Two fixes for list iterator variables being used when pointing to
the list head.

- Fix a kernel memory scribble when reading from a non-socket
transport in /sys/kernel/sunrpc.

- Fix a race where reconnecting to a server could leave the TCP
socket stuck forever in the connecting state.

- Patch from Neil to fix a shutdown race which can leave the SUNRPC
transport timer primed after we free the struct xprt itself.

- Patch from Xin Xiong to fix reference count leaks in the NFSv4.2
copy offload.

- Sunrpc patch from Olga to avoid resending a task on an offlined
transport.

Cleanups:

- Patches from Dave Wysochanski to clean up the fscache code"

* tag 'nfs-for-5.18-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (91 commits)
NFSv4/pNFS: Fix another issue with a list iterator pointing to the head
NFS: Don't loop forever in nfs_do_recoalesce()
SUNRPC: Don't return error values in sysfs read of closed files
SUNRPC: Do not dereference non-socket transports in sysfs
NFSv4.1: don't retry BIND_CONN_TO_SESSION on session error
SUNRPC don't resend a task on an offlined transport
NFS: replace usage of found with dedicated list iterator variable
SUNRPC: avoid race between mod_timer() and del_timer_sync()
pNFS/files: Ensure pNFS allocation modes are consistent with nfsiod
pNFS/flexfiles: Ensure pNFS allocation modes are consistent with nfsiod
NFSv4/pnfs: Ensure pNFS allocation modes are consistent with nfsiod
NFS: Avoid writeback threads getting stuck in mempool_alloc()
NFS: nfsiod should not block forever in mempool_alloc()
SUNRPC: Make the rpciod and xprtiod slab allocation modes consistent
SUNRPC: Fix unx_lookup_cred() allocation
NFS: Fix memory allocation in rpc_alloc_task()
NFS: Fix memory allocation in rpc_malloc()
SUNRPC: Improve accuracy of socket ENOBUFS determination
SUNRPC: Replace internal use of SOCKWQ_ASYNC_NOSPACE
SUNRPC: Fix socket waits for write buffer space
...

SUNRPC: improve 'swap' handling: scheduling and PF_MEMALLOC

2022-03-13T16:59:35+00:00

rpc tasks can be marked as RPC_TASK_SWAPPER.  This causes GFP_MEMALLOC
to be used for some allocations.  This is needed in some cases, but not
in all where it is currently provided, and in some where it isn't
provided.

Currently *all* tasks associated with a rpc_client on which swap is
enabled get the flag and hence some GFP_MEMALLOC support.

GFP_MEMALLOC is provided for ->buf_alloc() but only swap-writes need it.
However xdr_alloc_bvec does not get GFP_MEMALLOC - though it often does
need it.

xdr_alloc_bvec is called while the XPRT_LOCK is held.  If this blocks,
then it blocks all other queued tasks.  So this allocation needs
GFP_MEMALLOC for *all* requests, not just writes, when the xprt is used
for any swap writes.

Similarly, if the transport is not connected, that will block all
requests including swap writes, so memory allocations should get
GFP_MEMALLOC if swap writes are possible.

So with this patch:
 1/ we ONLY set RPC_TASK_SWAPPER for swap writes.
 2/ __rpc_execute() sets PF_MEMALLOC while handling any task
    with RPC_TASK_SWAPPER set, or when handling any task that
    holds the XPRT_LOCKED lock on an xprt used for swap.
    This removes the need for the RPC_IS_SWAPPER() test
    in ->buf_alloc handlers.
 3/ xprt_prepare_transmit() sets PF_MEMALLOC after locking
    any task to a swapper xprt.  __rpc_execute() will clear it.
 3/ PF_MEMALLOC is set for all the connect workers.

Reviewed-by: Chuck Lever  (for xprtrdma parts)
Signed-off-by: NeilBrown 
Signed-off-by: Trond Myklebust

SUNRPC/xprt: async tasks mustn't block waiting for memory

2022-03-13T16:59:35+00:00

When memory is short, new worker threads cannot be created and we depend
on the minimum one rpciod thread to be able to handle everything.  So it
must not block waiting for memory.

xprt_dynamic_alloc_slot can block indefinitely.  This can tie up all
workqueue threads and NFS can deadlock.  So when called from a
workqueue, set __GFP_NORETRY.

The rdma alloc_slot already does not block.  However it sets the error
to -EAGAIN suggesting this will trigger a sleep.  It does not.  As we
can see in call_reserveresult(), only -ENOMEM causes a sleep.  -EAGAIN
causes immediate retry.

Signed-off-by: NeilBrown 
Signed-off-by: Trond Myklebust

SUNRPC/call_alloc: async tasks mustn't block waiting for memory

2022-03-13T16:59:35+00:00

When memory is short, new worker threads cannot be created and we depend
on the minimum one rpciod thread to be able to handle everything.
So it must not block waiting for memory.

mempools are particularly a problem as memory can only be released back
to the mempool by an async rpc task running.  If all available
workqueue threads are waiting on the mempool, no thread is available to
return anything.

rpc_malloc() can block, and this might cause deadlocks.
So check RPC_IS_ASYNC(), rather than RPC_IS_SWAPPER() to determine if
blocking is acceptable.

Signed-off-by: NeilBrown 
Signed-off-by: Trond Myklebust

SUNRPC: Rename svc_close_xprt()

2022-02-28T15:26:40+00:00

Clean up: Use the "svc_xprt_" function naming convention as
is used for other external APIs.

Signed-off-by: Chuck Lever

SUNRPC/xprtrdma: Convert GFP_NOFS to GFP_KERNEL

2022-02-25T23:50:12+00:00

Assume that the upper layers have set memalloc_nofs_save/restore as
appropriate.

Signed-off-by: Trond Myklebust

xprtrdma: fix pointer derefs in error cases of rpcrdma_ep_create

2022-02-08T14:14:26+00:00

If there are failures then we must not leave the non-NULL pointers with
the error value, otherwise `rpcrdma_ep_destroy` gets confused and tries
free them, resulting in an Oops.

Signed-off-by: Dan Aloni 
Acked-by: Chuck Lever 
Signed-off-by: Anna Schumaker

xprtrdma: Remove definitions of RPCDBG_FACILITY

2022-01-14T15:35:08+00:00

Deprecated. dprintk is no longer used in xprtrdma.

Signed-off-by: Chuck Lever 
Signed-off-by: Anna Schumaker