NFSv4 requires us to ensure that we break the TCP connection before we're
allowed to retransmit a request. However in the case where we're
retransmitting several requests that have been sent on the same
connection, we need to ensure that we don't interfere with the attempt to
reconnect and/or break the connection again once it has been established.

We therefore introduce a 'connection' cookie that is bumped every time a
connection is broken. This allows requests to track if they need to force a
disconnection.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The condition for exiting from the loop in xs_tcp_send_request() should be
that we find we're not making progress (i.e. number of bytes sent is 0).
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The rest of the networking layer uses SOCK_ASYNC_NOSPACE to signal whether
or not we have someone waiting for buffer memory. Convert the SUNRPC layer
to use the same idiom.
Remove the unlikely()s in xs_udp_write_space and xs_tcp_write_space. In
fact, the most common case will be that there is nobody waiting for buffer
space.

SOCK_NOSPACE is there to tell the TCP layer whether or not the cwnd was
limited by the application window. Ensure that we follow the same idiom as
the rest of the networking layer here too.

Finally, ensure that we clear SOCK_ASYNC_NOSPACE once we wake up, so that
write_space() doesn't keep waking things up on xprt->pending.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Don't stop until we run out of data, or we hit an error.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: document the rule (kfree) and the exceptions
(RPC_DISPLAY_PROTO and RPC_DISPLAY_NETID) when freeing the objects in
a transport's address_strings array.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: have the set up routines explicitly pass the strings to be used
for the transport name and NETID.  This removes a number of conditionals
and dependencies on rpc_xprt.prot, which is overloaded.

Tighten up type checking on the address_strings array while we're at it.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

In order to be able to support setting the timeo and retrans parameters on
a per-mountpoint basis, we move the rpc_timeout structure into the
rpc_clnt.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If we've disconnected from the server, rather than the other way round,
then it makes little sense to wait 3 seconds before reconnecting.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

xprt_disconnect() should really only be called when the transport shutdown
is completed, and it is time to wake up any pending tasks. Rename it to
xprt_disconnect_done() in order to reflect the semantical change.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Move the calls to xprt_disconnect() over to xprt_force_disconnect() in
order to enable the transport layer to manage the state of the
XPRT_CONNECTED flag.
Ditto in xs_tcp_read_fraghdr().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The transport layer should do that itself whenever appropriate.

Note that the RDMA transport already assumes that it needs to call
xprt_disconnect in xprt_rdma_close().
For TCP sockets, we want to call xprt_disconnect() only after the
connection has been closed by both ends.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

By using shutdown() rather than close() we allow the RPC client to wait
for the TCP close handshake to complete before we start trying to reconnect
using the same port.
We use shutdown(SHUT_WR) only instead of shutting down both directions,
however we wait until the server has closed the connection on its side.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Add an xprt->state bit to enable the TCP ->state_change() method to signal
whether or not the TCP connection is in the process of closing down.
This will to be used by the reconnection logic in a separate patch.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Currently the TCP rebinding logic assumes that if we're not using a
reserved port, then we don't need to reconnect on the same port if a
disconnection event occurs. This breaks most RPC duplicate reply cache
implementations.

Also take into account the fact that xprt_min_resvport and
xprt_max_resvport may change while we're reconnecting, since the user may
change them at any time via the sysctls. Ensure that we check the port
boundaries every time we loop in xs_bind4/xs_bind6. Also ensure that if the
boundaries change, we only scan the ports a maximum of 2 times.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

When scheduling the autoclose RPC call, we want to ensure that we don't
race against the test_bit() call in xprt_clear_locked().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The previous move of the the UDP inDatagrams counter caused the
counting of encapsulated packets, SUNRPC data (as opposed to call)
packets and RXRPC packets to go missing.

This patch restores all of these.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

xs_setup_{udp,tcp}() can now become static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

xs_setup_{udp,tcp}() can now become static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Changes asserts in sunrpc to use sock_owned_by_user() macro instead of
referencing sock_lock.owner directly.
Signed-off-by: NJohn Heffner <jheffner@psc.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

xs_sendpages() may return a negative result. We sure as hell don't want to
add that to the 'tk_bytes_sent' tally...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFS performance metrics reported zero bytes sent per op when mounting with
UDP.  The UDP socket transport wasn't properly counting the number of bytes
sent.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

To prepare for including non-sockets-based RPC transports, select
RPC transports by an identifier (to be used in following patches).
Signed-off-by: NTom Talpey <tmt@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

To prepare for including non-sockets-based RPC transports, move the
sockets-dependent definitions into their own file.
Signed-off-by: NTom Talpey <tmt@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

To prepare for including non-sockets-based RPC transports, change the
overly suggestive name of the transport creation arguments struct.
Signed-off-by: NTom Talpey <tmt@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Allow RPC client transport implementations to be loaded as needed, or
as they become available from distributors or third-party vendors.

Note that we leave the IP sockets implementation in sunrpc.o
permanently, as IP functionality is always available in any
kernel that runs NFS.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTom Talpey <tmt@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The rpcbind (v3+) netid is provided by each RPC client transport. This fixes
an omission in IPv6 rpcbind client support, and enables future extension.
Signed-off-by: NTom Talpey <tmt@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

"Universal addresses" are a string representation of an IP address and
port.  They are described fully in RFC 3530, section 2.2.  Add support
for generating them in the RPC client's socket transport module.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Finalize support for setting up RPC client transports to remote RPC
services addressed via IPv6.

Based on work done by Gilles Quillard at Bull Open Source.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clone separate connect worker functions for connecting AF_INET6 sockets.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Prepare for introduction of IPv6 versions of same.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Finishing a socket connect is the same for IPv4 and IPv6, so split it out
into a helper.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clone xs_bindresvport into two functions, one that can handle IPv4
addresses, and one that can handle IPv6 addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Prepare for introduction of IPv6-specific socket bind function.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We could clone xs_set_port, but this is easier overall.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clone xs_format_ipv4_peer_addresses into an IPv6 version.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Prepare to add an IPv6 version of xs_format_peer_addresses by renaming it
to xs_format_ipv4_peer_addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>