Some architectures, such as ARM-32 do not return the same base address
when you call kmap_atomic() twice on the same page.
This causes problems for the memmove() call in the XDR helper routine
"_shift_data_right_pages()", since it defeats the detection of
overlapping memory ranges, and has been seen to corrupt memory.

The fix is to distinguish between the case where we're doing an
inter-page copy or not. In the former case of we know that the memory
ranges cannot possibly overlap, so we can additionally micro-optimise
by replacing memmove() with memcpy().

Reported-by: Mark Young <MYoung@nvidia.com>
Reported-by: Matt Craighead <mcraighead@nvidia.com>
Cc: Bruce Fields <bfields@fieldses.org>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Matt Craighead <mcraighead@nvidia.com>

If rpcbind causes our connection to the AF_LOCAL socket to close after
we've registered a service, then we want to be careful about reconnecting
since the mount namespace may have changed.

By simply refusing to reconnect the AF_LOCAL socket in the case of
unregister, we avoid the need to somehow save the mount namespace. While
this may lead to some services not unregistering properly, it should
be safe.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Nix <nix@esperi.org.uk>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org # 3.9.x

There is no need for the kernel to time out the AF_LOCAL connection to
the rpcbind socket, and doing so is problematic because when it is
time to reconnect, our process may no longer be using the same mount
namespace.

Reported-by: Nix <nix@esperi.org.uk>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org # 3.9.x

The change made to rsc_parse() in
0dc1531aca7fd1440918bd55844a054e9c29acad "svcrpc: store gss mech in
svc_cred" should also have been propagated to the gss-proxy codepath.
This fixes a crash in the gss-proxy case.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

mech_oid.data is an array, not kmalloc()'d memory.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Uninitialized stack data was being used as the destination for memcpy's.

Longer term we'll just delete some of this code; all we're doing is
skipping over xdr that we don't care about.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Since we enabled auto-tuning for sunrpc TCP connections we do not
guarantee that there is enough write-space on each connection to
queue a reply.

If memory pressure causes the window to shrink too small, the request
throttling in sunrpc/svc will not accept any requests so no more requests
will be handled.  Even when pressure decreases the window will not
grow again until data is sent on the connection.
This means we get a deadlock:  no requests will be handled until there
is more space, and no space will be allocated until a request is
handled.

This can be simulated by modifying svc_tcp_has_wspace to inflate the
number of byte required and removing the 'svc_sock_setbufsize' calls
in svc_setup_socket.

I found that multiplying by 16 was enough to make the requirement
exceed the default allocation.  With this modification in place:
   mount -o vers=3,proto=tcp 127.0.0.1:/home /mnt
would block and eventually time out because the nfs server could not
accept any requests.

This patch relaxes the request throttling to always allow at least one
request through per connection.  It does this by checking both
  sk_stream_min_wspace() and xprt->xpt_reserved
are zero.
The first is zero when the TCP transmit queue is empty.
The second is zero when there are no RPC requests being processed.
When both of these are zero the socket is idle and so one more
request can safely be allowed through.

Applying this patch allows the above mount command to succeed cleanly.
Tracing shows that the allocated write buffer space quickly grows and
after a few requests are handled, the extra tests are no longer needed
to permit further requests to be processed.

The main purpose of request throttling is to handle the case when one
client is slow at collecting replies and the send queue gets full of
replies that the client hasn't acknowledged (at the TCP level) yet.
As we only change behaviour when the send queue is empty this main
purpose is still preserved.

Reported-by: Ben Myers <bpm@sgi.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Pull NFS client bugfixes from Trond Myklebust:
 - Fix a regression against NFSv4 FreeBSD servers when creating a new
   file
 - Fix another regression in rpc_client_register()

* tag 'nfs-for-3.11-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4: Fix a regression against the FreeBSD server
  SUNRPC: Fix another issue with rpc_client_register()

Pull nfsd bugfixes from Bruce Fields:
 "Just three minor bugfixes"

* 'for-3.11' of git://linux-nfs.org/~bfields/linux:
  svcrdma: underflow issue in decode_write_list()
  nfsd4: fix minorversion support interface
  lockd: protect nlm_blocked access in nlmsvc_retry_blocked