Fix the error pathway if rpcauth_create() fails.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

just pass the name
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Commit 38481605 (SUNRPC: fix races on
PipeFS MOUNT notifications) introduces a regression when we call
rpc_setup_pipedir() with RPCSEC_GSS as the auth flavour.

By calling rpcauth_create() while holding the sn->pipefs_sb_lock, we
end up deadlocking in gss_pipes_dentries_create_net().
Fix is to register the client and release the mutex before calling
rpcauth_create().
Reported-by: NWeston Andros Adamson <dros@netapp.com>
Tested-by: NWeston Andros Adamson <dros@netapp.com>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: <stable@vger.kernel.org> # : 38481605: SUNRPC: fix races on PipeFS MOUNT
Cc: <stable@vger.kernel.org> # : e73f4cc0: SUNRPC: split client creation
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Not need to create pipes for dying client. So just skip them.

Note: we can safely dereference the client structure, because notification
caller is holding sn->pipefs_sb_lock.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This helper moves all "registration" code to the new rpc_client_register()
helper.
This helper will be used later in the series to synchronize against PipeFS
MOUNT/UMOUNT events.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

CPU#0                                   CPU#1
-----------------------------           -----------------------------
rpc_kill_sb
sn->pipefs_sb = NULL                    rpc_release_client
(UMOUNT_EVENT)                          rpc_free_auth
rpc_pipefs_event
rpc_get_client_for_event
!atomic_inc_not_zero(cl_count)
<skip the client>
                                        atomic_inc(cl_count)
                                        rpc_free_client
                                        rpc_clnt_remove_pipedir
                                        <skip client dir removing>

To fix this, this patch does the following:

1) Calls RPC_PIPEFS_UMOUNT notification with sn->pipefs_sb_lock being held.
2) Removes SUNRPC client from the list AFTER pipes destroying.
3) Doesn't hold RPC client on notification: if client in the list, then it
can't be destroyed while sn->pipefs_sb_lock in hold by notification caller.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Below are races, when RPC client can be created without PiepFS dentries

CPU#0					CPU#1
-----------------------------		-----------------------------
rpc_new_client				rpc_fill_super
rpc_setup_pipedir
mutex_lock(&sn->pipefs_sb_lock)
rpc_get_sb_net == NULL
(no per-net PipeFS superblock)
					sn->pipefs_sb = sb;
					notifier_call_chain(MOUNT)
					(client is not in the list)
rpc_register_client
(client without pipes dentries)

To fix this patch:
1) makes PipeFS mount notification call with pipefs_sb_lock being held.
2) releases pipefs_sb_lock on new SUNRPC client creation only after
registration.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Just convert those messages to dprintk()s so that they can be used
when debugging.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This patch implements a sunrpc client to use the services of the gssproxy
userspace daemon.

In particular it allows to perform calls in user space using an RPC
call instead of custom hand-coded upcall/downcall messages.

Currently only accept_sec_context is implemented as that is all is needed for
the server case.

File server modules like NFS and CIFS can use full gssapi services this way,
once init_sec_context is also implemented.

For the NFS server case this code allow to lift the limit of max 2k krb5
tickets. This limit is prevents legitimate kerberos deployments from using krb5
authentication with the Linux NFS server as they have normally ticket that are
many kilobytes large.

It will also allow to lift the limitation on the size of the credential set
(uid,gid,gids) passed down from user space for users that have very many groups
associated. Currently the downcall mechanism used by rpc.svcgssd is limited
to around 2k secondary groups of the 65k allowed by kernel structures.
Signed-off-by: NSimo Sorce <simo@redhat.com>
[bfields: containerization, concurrent upcalls, misc. fixes and cleanup]
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

In the gss-proxy case we don't want to have to reconnect at random--we
want to connect only on gss-proxy startup when we can steal gss-proxy's
context to do the connect in the right namespace.

So, provide a flag that allows the rpc_create caller to turn off the
idle timeout.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This is mainly for use by NFSv4.1, where the session negotiation
ultimately wants to decide how many RPC slots we can fill.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This patch ensures that we throttle new RPC requests if there are
requests already waiting in the xprt->backlog queue. The reason for
doing this is to fix livelock issues that can occur when an existing
(high priority) task is waiting in the backlog queue, gets woken up
by xprt_free_slot(), but a new task then steals the slot.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the call to rpciod_up() fails, we currently leak a reference to the
struct rpc_xprt.
As part of the fix, we also remove the redundant check for xprt!=NULL.
This is already taken care of by the callers.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

While testing error cases where rpc_new_client() fails, I saw
some oopses.

If rpc_new_client() fails, it already invokes xprt_put().  Thus
__rpc_clone_client() does not need to invoke it again.

Introduced by commit 1b63a751 "SUNRPC: Refactor rpc_clone_client()"
Fri Sep 14, 2012.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org [>=3.7]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

In the case of a SOFTCONN rpc task, we really want to ensure that it
reports errors like ENETUNREACH back to the caller. Currently, only
some of these errors are being reported back (connect errors are not),
and they are being converted by the RPC layer into EIO.
Reported-by: NJan Engelhardt <jengelh@inai.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Reported-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Returns the configured timeout for the xprt of the rpc client.
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

These routines are used by server and client code, so having them in a
separate header would be best.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Acked-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Avoid an RCU dereference by removing task->tk_xprt
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

tk_xprt is just a shortcut for tk_client->cl_xprt, however cl_xprt is
defined as an __rcu variable. Replace dereferences of tk_xprt with
non-rcu dereferences where it is safe to do so.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fix new kernel-doc warnings in clnt.c:

  Warning(net/sunrpc/clnt.c:561): No description found for parameter 'flavor'
  Warning(net/sunrpc/clnt.c:561): Excess function parameter 'auth' description in 'rpc_clone_client_set_auth'
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Partially revert commit (SUNRPC: add WARN_ON_ONCE for potential deadlock).
The looping behaviour has been tracked down to a knownn issue with
workqueues, and a workaround has now been implemented.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Weston Andros Adamson <dros@netapp.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Bruce Fields <bfields@fieldses.org>
Cc: stable@vger.kernel.org [>= 3.7]

There are SUNRPC clients, which program doesn't have pipe_dir_name. These
clients can be skipped on PipeFS events, because nothing have to be created or
destroyed. But instead of breaking in case of such a client was found, search
for suitable client over clients list have to be continued. Otherwise some
clients could not be covered by PipeFS event handler.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Cc: stable@vger.kernel.org [>= v3.4]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Currently, when an RPCSEC_GSS context has expired or is non-existent
and the users (Kerberos) credentials have also expired or are non-existent,
the client receives the -EKEYEXPIRED error and tries to refresh the context
forever.  If an application is performing I/O, or other work against the share,
the application hangs, and the user is not prompted to refresh/establish their
credentials. This can result in a denial of service for other users.

Users are expected to manage their Kerberos credential lifetimes to mitigate
this issue.

Move the -EKEYEXPIRED handling into the RPC layer. Try tk_cred_retry number
of times to refresh the gss_context, and then return -EACCES to the application.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We can and should use the rpc_create_args and __rpc_clone_client()
to change the program and version number on the resulting rpc_client.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Use WARN_ON_ONCE instead of calling BUG_ON and return -EINVAL when
RPC_TASK_ASYNC flag is passed to rpc_call_sync.
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Remove redundant BUG_ON().
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Replace BUG_ON() with WARN_ON_ONCE().
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Remove unneeded BUG_ON()
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Replace BUG_ON() with WARN_ON_ONCE() - rpc_run_bc_task calls rpc_init_task()
then increments the tk_count, so this is a simple sanity check that
if hit once would hit every time this code path is executed.
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Print a KERN_INFO message before rpc_d_lookup_sb returns NULL, like
other error paths in that function.
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

rpc_shutdown_client should never be called from a workqueue context.
If it is, it could deadlock looping forever trying to kill tasks that are
assigned to the same kworker thread (and will never run rpc_exit_task).
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

An ULP is supposed to be able to replace a GSS rpc_auth object with
another GSS rpc_auth object using rpcauth_create().  However,
rpcauth_create() in 3.5 reliably fails with -EEXIST in this case.
This is because when gss_create() attempts to create the upcall pipes,
sometimes they are already there.  For example if a pipe FS mount
event occurs, or a previous GSS flavor was in use for this rpc_clnt.

It turns out that's not the only problem here.  While working on a
fix for the above problem, we noticed that replacing an rpc_clnt's
rpc_auth is not safe, since dereferencing the cl_auth field is not
protected in any way.

So we're deprecating the ability of rpcauth_create() to switch an
rpc_clnt's security flavor during normal operation.  Instead, let's
add a fresh API that clones an rpc_clnt and gives the clone a new
flavor before it's used.

This makes immediate use of the new __rpc_clone_client() helper.

This can be used in a similar fashion to rpcauth_create() when a
client is hunting for the correct security flavor.  Instead of
replacing an rpc_clnt's security flavor in a loop, the ULP replaces
the whole rpc_clnt.

To fix the -EEXIST problem, any ULP logic that relies on replacing
an rpc_clnt's rpc_auth with rpcauth_create() must be changed to use
this API instead.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

rpc_clone_client() does most of the same tasks as rpc_new_client(),
so there is an opportunity for code re-use.  Create a generic helper
that makes it easy to clone an RPC client while replacing any of the
clnt's parameters.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Implement the new swapfile a_ops for NFS and hook up ->direct_IO.  This
will set the NFS socket to SOCK_MEMALLOC and run socket reconnect under
PF_MEMALLOC as well as reset SOCK_MEMALLOC before engaging the protocol
->connect() method.

PF_MEMALLOC should allow the allocation of struct socket and related
objects and the early (re)setting of SOCK_MEMALLOC should allow us to
receive the packets required for the TCP connection buildup.

[jlayton@redhat.com: Restore PF_MEMALLOC task flags in all cases]
[dfeng@redhat.com: Fix handling of multiple swap files]
[a.p.zijlstra@chello.nl: Original patch]
Signed-off-by: NMel Gorman <mgorman@suse.de>
Acked-by: NRik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a missing set of braces that commit 4e0038b6
("SUNRPC: Move clnt->cl_server into struct rpc_xprt")
forgot.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org [>= 3.4]

Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

xprt_alloc_slot will call rpc_delay() to make the task wait a bit before
retrying when it gets back an -ENOMEM error from xprt_dynamic_alloc_slot.
The problem is that rpc_delay will clear the task->tk_status, causing
call_reserveresult to abort the task.

The solution is simply to let call_reserveresult handle the ENOMEM error
directly.
Reported-by: NJeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org [>= 3.1]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This allows comparing hash and len in one operation on 64-bit
architectures.  Right now only __d_lookup_rcu() takes advantage of this,
since that is the case we care most about.

The use of anonymous struct/unions hides the alternate 64-bit approach
from most users, the exception being a few cases where we initialize a
'struct qstr' with a static initializer.  This makes the problematic
cases use a new QSTR_INIT() helper function for that (but initializing
just the name pointer with a "{ .name = xyzzy }" initializer remains
valid, as does just copying another qstr structure).
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that the rpc client is namespace aware, it needs to use the
utsname of the process that created it instead of using the
init_utsname. Both rpc_new_client and rpc_clone_client need to
be fixed.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>