Move error reporting for RPC registration to rpcb_register's caller.

This way the caller can choose to recover silently from certain
errors, but report errors it does not recognize.  Error reporting
for kernel RPC service registration is now handled in one place.

This patch is part of a series that addresses
   http://bugzilla.kernel.org/show_bug.cgi?id=12256Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The kernel registers RPC services with the local portmapper with an
rpcbind SET upcall to the local portmapper.  Traditionally, this used
rpcbind v2 (PMAP), but registering RPC services that support IPv6
requires rpcbind v3 or v4.

Since we now want separate PF_INET and PF_INET6 listeners for each
kernel RPC service, svc_register() will do only one of those
registrations at a time.

For PF_INET, it tries an rpcb v4 SET upcall first; if that fails, it
does a legacy portmap SET.  This makes it entirely backwards
compatible with legacy user space, but allows a proper v4 SET to be
used if rpcbind is available.

For PF_INET6, it does an rpcb v4 SET upcall.  If that fails, it fails
the registration, and thus the transport creation.  This let's the
kernel detect if user space is able to support IPv6 RPC services, and
thus whether it should maintain a PF_INET6 listener for each service
at all.

This provides complete backwards compatibilty with legacy user space
that only supports rpcbind v2.  The only down-side is that registering
a new kernel RPC service may take an extra exchange with the local
portmapper on legacy systems, but this is an infrequent operation and
is done over UDP (no lingering sockets in TIMEWAIT), so it shouldn't
be consequential.

This patch is part of a series that addresses
   http://bugzilla.kernel.org/show_bug.cgi?id=12256Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Our initial implementation of svc_unregister() assumed that PMAP_UNSET
cleared all rpcbind registrations for a [program, version] tuple.
However, we now have evidence that PMAP_UNSET clears only "inet"
entries, and not "inet6" entries, in the rpcbind database.

For backwards compatibility with the legacy portmapper, the
svc_unregister() function also must work if user space doesn't support
rpcbind version 4 at all.

Thus we'll send an rpcbind v4 UNSET, and if that fails, we'll send a
PMAP_UNSET.

This simplifies the code in svc_unregister() and provides better
backwards compatibility with legacy user space that does not support
rpcbind version 4.  We can get rid of the conditional compilation in
here as well.

This patch is part of a series that addresses
   http://bugzilla.kernel.org/show_bug.cgi?id=12256Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The user space TI-RPC library uses an empty string for the universal
address when unregistering all target addresses for [program, version].
The kernel's rpcb client should behave the same way.

Here, we are switching between several registration methods based on
the protocol family of the incoming address.  Rename the other rpcbind
v4 registration functions to make it clear that they, as well, are
switched on protocol family.  In /etc/netconfig, this is either "inet"
or "inet6".

NB: The loopback protocol families are not supported in the kernel.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

RFC 1833 has little to say about the contents of r_owner; it only
specifies that it is a string, and states that it is used to control
who can UNSET an entry.

Our port of rpcbind (from Sun) assumes this string contains a numeric
UID value, not alphabetical or symbolic characters, but checks this
value only for AF_LOCAL RPCB_SET or RPCB_UNSET requests.  In all other
cases, rpcbind ignores the contents of the r_owner string.

The reference user space implementation of rpcb_set(3) uses a numeric
UID for all SET/UNSET requests (even via the network) and an empty
string for all other requests.  We emulate that behavior here to
maintain bug-for-bug compatibility.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: Simplify rpcb_v4_register() and its helpers by moving the
details of sockaddr type casting to rpcb_v4_register()'s helper
functions.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The RPC client returns -EPROTONOSUPPORT if there is a protocol version
mismatch (ie the remote RPC server doesn't support the RPC protocol
version sent by the client).

Helpers for the svc_register() function return -EPROTONOSUPPORT if they
don't recognize the passed-in IPPROTO_ value.

These are two entirely different failure modes.

Have the helpers return -ENOPROTOOPT instead of -EPROTONOSUPPORT.  This
will allow callers to determine more precisely what the underlying
problem is, and decide to report or recover appropriately.

This patch is part of a series that addresses
   http://bugzilla.kernel.org/show_bug.cgi?id=12256Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The kernel uses an IPv6 loopback address when registering its AF_INET6
RPC services so that it can tell whether the local portmapper is
actually IPv6-enabled.

Since the legacy portmapper doesn't listen on IPv6, however, this
causes a long timeout on older systems if the kernel happens to try
creating and registering an AF_INET6 RPC service.  Originally I wanted
to use a connected transport (either TCP or connected UDP) so that the
upcall would fail immediately if the portmapper wasn't listening on
IPv6, but we never agreed on what transport to use.

In the end, it's of little consequence to the kernel whether the local
portmapper is listening on IPv6.  It's only important whether the
portmapper supports rpcbind v4.  And the kernel can't tell that at all
if it is sending requests via IPv6 -- the portmapper will just ignore
them.

So, send both rpcbind v2 and v4 SET/UNSET requests via IPv4 loopback
to maintain better backwards compatibility between new kernels and
legacy user space, and prevent multi-second hangs in some cases when
the kernel attempts to register RPC services.

This patch is part of a series that addresses

   http://bugzilla.kernel.org/show_bug.cgi?id=12256Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We are about to convert to using separate RPC listener sockets for
PF_INET and PF_INET6.  This echoes the way IPv6 is handled in user
space by TI-RPC, and eliminates the need for ULPs to worry about
mapped IPv4 AF_INET6 addresses when doing address comparisons.

Start by setting the IPV6ONLY flag on PF_INET6 RPC listener sockets.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We're about to convert over to using separate PF_INET and PF_INET6
listeners, instead of a single PF_INET6 listener that also receives
AF_INET requests and maps them to AF_INET6.

Clear the way by removing the logic in lockd and the NFSv4 callback
server that creates an AF_INET6 service listener.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Since an RPC service listener's protocol family is specified now via
svc_create_xprt(), it no longer needs to be passed to svc_create() or
svc_create_pooled().  Remove that argument from the synopsis of those
functions, and remove the sv_family field from the svc_serv struct.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The sv_family field is going away.  Pass a protocol family argument to
svc_create_xprt() instead of extracting the family from the passed-in
svc_serv struct.

Again, as this is a listener socket and not an address, we make this
new argument an "int" protocol family, instead of an "sa_family_t."
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Since the sv_family field is going away, modify svc_setup_socket() to
extract the protocol family from the passed-in socket instead of from
the passed-in svc_serv struct.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The sv_family field is going away.  Instead of using sv_family, have
the svc_register() function take a protocol family argument.

Since this argument represents a protocol family, and not an address
family, this argument takes an int, as this is what is passed to
sock_create_kern().  Also make sure svc_register's helpers are
checking for PF_FOO instead of AF_FOO.  The value of [AP]F_FOO are
equivalent; this is simply a symbolic change to reflect the semantics
of the value stored in that variable.

sock_create_kern() should return EPFNOSUPPORT if the passed-in
protocol family isn't supported, but it uses EAFNOSUPPORT for this
case.  We will stick with that tradition here, as svc_register()
is called by the RPC server in the same path as sock_create_kern().
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: add documentating comment and use appropriate data types for
svc_find_xprt()'s arguments.

This also eliminates a mixed sign comparison: @port was an int, while
the return value of svc_xprt_local_port() is an unsigned short.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Make sure port value read from user space by write_ports is valid before
passing it to svc_find_xprt().  If it wasn't, the writer would get ENOENT
instead of EINVAL.
Noticed-by: NJ. Bruce Fields <bfields@fieldses.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up:  Enable the use of const arguments in higher level svc_ APIs
by adding const to the arguments of the helper functions in svc_xprt.h
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

In 2007, commit e65fe397 added
additional sanity checking to rpcb_decode_getaddr() to make sure we
were getting a reply that was long enough to be an actual universal
address.  If the uaddr string isn't long enough, the XDR decoder
returns EIO.

However, an empty string is a valid RPCB_GETADDR response if the
requested service isn't registered.  Moreover, "::.n.m" is also a
valid RPCB_GETADDR response for IPv6 addresses that is shorter
than rpcb_decode_getaddr()'s lower limit of 11.  So this sanity
check introduced a regression for rpcbind requests against IPv6
remotes.

So revert the lower bound check added by commit
e65fe397, and add an explicit check
for an empty uaddr string, similar to libtirpc's rpcb_getaddr(3).
Pointed-out-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Close-to-open cache consistency rules really only require us to flush out
writes on calls to close(), and require us to revalidate attributes on the
very last close of the file.

Currently we appear to be doing a lot of extra attribute revalidation
and cache flushes.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFS appears to be returning an unnecessary "delete" notification when
we're doing an atomic rename. See

  http://bugzilla.gnome.org/show_bug.cgi?id=575684

The fix is to get rid of the redundant call to d_delete().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Move the definition of nfs_need_commit() into the #ifdef CONFIG_NFS_V3
section as originally intended in the patch "NFS: cleanup - remove
struct nfs_inode->ncommit"
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

printk formats in prior commit were reversed/incorrect.
Compiled without warning on x86 and x86_64, but detected on ppc.
Signed-off-by: NTom Talpey <tmtalpey@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

As long as one task is holding the socket lock, then calls to
xprt_force_disconnect(xprt) will not succeed in shutting down the socket.
In particular, this would mean that a server initiated shutdown will not
succeed until the lock is relinquished.
In order to avoid the deadlock, we should ensure that xs_tcp_send_request()
closes the socket on EPIPE errors too.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

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

This fixes a regression against FreeBSD servers as reported by Tomas
Kasparek. Apparently when using RPC over a TCP socket, the FreeBSD servers
don't ever react to the client closing the socket, and so commit
e06799f9 (SUNRPC: Use shutdown() instead of
close() when disconnecting a TCP socket) causes the setup to hang forever
whenever the client attempts to close and then reconnect.

We break the deadlock by adding a 'linger2' style timeout to the socket,
after which, the client will abort the connection using a TCP 'RST'.

The default timeout is set to 15 seconds. A subsequent patch will put it
under user control by means of a systctl.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If xs_nospace() finds that the socket has disconnected, it attempts to
return ENOTCONN, however that value is then squashed by the callers.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Enforce the comment in xs_tcp_connect_worker4/xs_tcp_connect_worker6 that
we should delay, then retry on certain connection errors.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

While we should definitely return socket errors to the task that is
currently trying to send data, there is no need to propagate the same error
to all the other tasks on xprt->pending. Doing so actually slows down
recovery, since it causes more than one tasks to attempt socket recovery.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Ensure that we pick up and handle socket errors as they occur.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If we get an ECONNREFUSED error, we currently go to sleep on the
'xprt->sending' wait queue. The problem is that no timeout is set there,
and there is nothing else that will wake the task up later.

We should deal with ECONNREFUSED in call_status, given that is where we
also deal with -EHOSTDOWN, and friends.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

...so that we can distinguish between when we need to shutdown and when we
don't. Also remove the call to xs_tcp_shutdown() from xs_tcp_connect(),
since xprt_connect() makes the same test.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the socket is unconnected, and xprt_transmit() returns ENOTCONN, we
currently give up the lock on the transport channel. Doing so means that
the lock automatically gets assigned to the next task in the xprt->sending
queue, and so that task needs to be woken up to do the actual connect.

The following patch aims to avoid that unnecessary task switch.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

When mounting an NFS/RDMA server with the "-o proto=rdma" or
"-o rdma" options, attempt to dynamically load the necessary
"xprtrdma" client transport module. Doing so improves usability,
while avoiding a static module dependency and any unnecesary
resources.
Signed-off-by: NTom Talpey <tmtalpey@gmail.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Provide an api to attempt to load any necessary kernel RPC
client transport module automatically. By convention, the
desired module name is "xprt"+"transport name". For example,
when NFS mounting with "-o proto=rdma", attempt to load the
"xprtrdma" module.
Signed-off-by: NTom Talpey <tmtalpey@gmail.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Certain client rpc's which contain both lengthy page-contained
metadata and a non-empty xdr_tail buffer require careful handling
to avoid overlapped memory copying. Rearranging of existing rpcrdma
marshaling code avoids it; this fixes an NFSv4 symlink creation error
detected with connectathon basic/test8 to multiple servers.
Signed-off-by: NTom Talpey <tmtalpey@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Certain client-provided RPCRDMA chunk alignments result in an
additional scatter/gather entry, which triggered nfs/rdma server
assertions incorrectly. OpenSolaris nfs/rdma client connectathon
testing was blocked by these in the special/locking section.
Signed-off-by: NTom Talpey <tmtalpey@gmail.com>
Cc: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Bryan Wu reports that when compiling NFS on nommu machines he gets a
"defined but not used" error on nfs_file_mmap().

The easiest fix is simply to get rid of the special casing in NFS, and
just always call generic_file_mmap() to set up the file.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The following patch is a combination of a patch by myself and Peter
Staubach.

Trond: If we allow other processes to dirty pages while a process is doing
a consistency sync to disk, we can end up never making progress.

Peter: Attached is a patch which addresses a continuing problem with
the NFS client generating out of order WRITE requests.  While
this is compliant with all of the current protocol
specifications, there are servers in the market which can not
handle out of order WRITE requests very well.  Also, this may
lead to sub-optimal block allocations in the underlying file
system on the server.  This may cause the read throughputs to
be reduced when reading the file from the server.

Peter: There has been a lot of work recently done to address out of
order issues on a systemic level.  However, the NFS client is
still susceptible to the problem.  Out of order WRITE
requests can occur when pdflush is in the middle of writing
out pages while the process dirtying the pages calls
generic_file_buffered_write which calls
generic_perform_write which calls
balance_dirty_pages_rate_limited which ends up calling
writeback_inodes which ends up calling back into the NFS
client to writes out dirty pages for the same file that
pdflush happens to be working with.
Signed-off-by: NPeter Staubach <staubach@redhat.com>
[modification by Trond to merge the two similar patches]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>