When server gets drc mem fail, it should reply error to client.
Signed-off-by: NMi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We're refusing to support a mandatory features of 4.1, so serverfault
seems the better error; see e.g.:

	http://www.ietf.org/mail-archive/web/nfsv4/current/msg07638.htmlSigned-off-by: NJ. Bruce Fields <bfields@redhat.com>

The original code would oops if this were called from nfsd4_setattr()
because "filpp" is NULL.

(Note this case is currently impossible, as long as we only give out
read delegations.)
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If a connection is closed just after a sequence or create_session
is sent over it, we could end up trying to register a callback that will
never get called since the xprt is already marked dead.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The caller allocated it, the caller should free it.

The only issue so far is that we could change the flp pointer even on an
error return if the fl_change callback failed.  But we can simply move
the flp assignment after the fl_change invocation, as the callers don't
care about the flp return value if the setlease call failed.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The NFSv4 server was initializing the dp->dl_flock pointer by the
somewhat ridiculous method of a locks_copy_lock callback.

Now that setlease uses the passed-in lock instead of doing a copy,
dl_flock no longer gets set, resulting in the lock leaking on delegation
release, and later possible hangs (among other problems).

So, initialize dl_flock and get rid of the callback.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As suggested by Christoph Hellwig, this moves allocation
of new file locks out of generic_setlease into the
callers, nfs4_open_delegation and fcntl_setlease in order
to allow GFP_KERNEL allocations when lock_flocks has
become a spinlock.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NJ. Bruce Fields <bfields@redhat.com>

We're doing an allocation under a spinlock, and ignoring the
possibility of allocation failure.

A better fix wouldn't require an unnecessary allocation in the common
case, but we'll leave that for later.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The minorversion seems more a property of the client than the callback
channel.

Some time we should probably also enforce consistent minorversion usage
from the client; for now, this is just a cosmetic change.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Have unhash_client_locked() remove client and associated sessions from
global hashes, but delay further dismantling till free_client().

(After unhash_client_locked(), the only remaining references outside the
destroying thread are from any connections which have xpt_user callbacks
registered.)

This will simplify locking on session destruction.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Only one of the nfsd4_callback_probe callers actually cares about
changing the callback information.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The callback program is allowed to depend on the session which the
callback is going over.

No change in behavior yet, while we still only do callbacks over a
single session for the lifetime of the client.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We need to keep track of which connections are available for use with
the backchannel, which for the forechannel, and which for both.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Following rfc 5661, section 18.36.4: "If the session is not successfully
created, then no changes are made to any client records on the server."
We shouldn't be confirming or incrementing the sequence id in this case.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Currently we don't deal well with a client that has multiple sessions
associated with it (even simultaneously, or serially over the lifetime
of the client).

In particular, we don't attempt to keep the backchannel running after
the original session diseappears.

We will fix that soon.

Once we do that, we need the slot sequence number to be per-session;
otherwise, for example, we cannot correctly handle a case like this:

	- All session 1 connections are lost.
	- The client creates session 2.  We use it for the backchannel
	  (since it's the only working choice).
	- The client gives us a new connection to use with session 1.
	- The client destroys session 2.

At this point our only choice is to go back to using session 1.  When we
do so we must use the sequence number that is next for session 1.  We
therefore need to maintain multiple sequence number streams.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Instead of copying the sessionid, use the new cl_cb_session pointer,
which indicates which session we're using for the backchannel.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The backchannel should  be associated with a session, it isn't really
global to the client.

We do, however, want a pointer global to the client which tracks which
session we're currently using for client-based callbacks.

This is a first step in that direction; for now, just reshuffling of
code with no significant change in behavior.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

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

This prepares the removal of the big kernel lock from the
file locking code. We still use the BKL as long as fs/lockd
uses it and ceph might sleep, but we can flip the definition
to a private spinlock as soon as that's done.
All users outside of fs/lockd get converted to use
lock_flocks() instead of lock_kernel() where appropriate.

Based on an earlier patch to use a spinlock from Matthew
Wilcox, who has attempted this a few times before, the
earliest patch from over 10 years ago turned it into
a semaphore, which ended up being slower than the BKL
and was subsequently reverted.

Someone should do some serious performance testing when
this becomes a spinlock, since this has caused problems
before. Using a spinlock should be at least as good
as the BKL in theory, but who knows...
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMatthew Wilcox <willy@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Sage Weil <sage@newdream.net>
Cc: linux-kernel@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org

Commit 78155ed7 "nfsd4: distinguish
expired from stale stateids" attempted to distinguish expired and stale
stateid's using time information that may not have been completely
reliable, so I reverted it.

That was throwing out the baby with the bathwater; we still do want to
return expired, but let's do that using the simpler approach of just
assuming any stateid is expired if it looks like it was given out by the
current server instance, but we can't find it any more.

This may help clients that are recovering from network partitions.
Reported-by: NBian Naimeng <biannm@cn.fujitsu.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

As long as we're not implementing any session security, we should just
automatically add any new connections that come along to the list of
sessions associated with the session.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

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

Remove connections from the list when they go down.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The spec requires us in various places to keep track of the connections
associated with each session.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Changes:
	- make sure session memory reservation is released on failure
	  path.
	- use min_t()/min() for more compact code in several places.
	- break alloc_init_session into smaller pieces.
	- miscellaneous other cleanup.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This returns an nfs error, not -ERRNO.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Note we're allocating an array of nfsd4_slot *'s, not nfsd4_slot's.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Instead of creating the new rpc client from a regular server thread,
set a flag, kick off a null call, and allow the null call to do the work
of setting up the client on the callback workqueue.

Use a spinlock to ensure the callback work gets a consistent view of the
callback parameters.

This allows, for example, changing the callback from contexts where
sleeping is not allowed.  I hope it will also keep the locking simple as
we add more session and trunking features, by serializing most of the
callback-specific work.

This also closes a small race where the the new cb_ident could be used
with an old connection (or vice-versa).
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This will eventually allow us, for example, to kick off null callback
from contexts where we can't sleep.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Now that we have both nfsd4_callback and nfsd4_cb_conn structures, I get
confused if variables of both types are always named cb....
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This fixes an unnecessary BUG().
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If we already had a RW open for a file, and get a readonly open, we were
piggybacking on the existing RW open.  That's inconsistent with the
downgrade logic which blows away the RW open assuming you'll still have
a readonly open.

Also, make sure there is a readonly or writeonly open available for
locking, again to prevent bad behavior in downgrade cases when any RW
open may be lost.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

It's OK for this function to return without setting filp--we do it in
the special-stateid case.

And there's a legitimate case where we can hit this, since we do permit
reads on write-only stateid's.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Commit f9d7562f "nfsd4: share file
descriptors between stateid's" didn't correctly account for O_RDWR opens.
Symptoms include leaked files, resulting in failures to unmount and/or
warnings about orphaned inodes on reboot.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Fixes at least one real minor bug: the nfs4 recovery dir sysctl
would not return its status properly.

Also I finished Al's 1e41568d ("Take ima_path_check() in nfsd
past dentry_open() in nfsd_open()") commit, it moved the IMA
code, but left the old path initializer in there.

The rest is just dead code removed I think, although I was not
fully sure about the "is_borc" stuff. Some more review
would be still good.

Found by gcc 4.6's new warnings.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The vfs doesn't really allow us to "upgrade" a file descriptor from
read-only to read-write, and our attempt to do so in nfs4_upgrade_open
is ugly and incomplete.

Move to a different scheme where we keep multiple opens, shared between
open stateid's, in the nfs4_file struct.  Each file will be opened at
most 3 times (for read, write, and read-write), and those opens will be
shared between all clients and openers.  On upgrade we will do another
open if necessary instead of attempting to upgrade an existing open.
We keep count of the number of readers and writers so we know when to
close the shared files.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

It is legal to perform a write using the lock stateid that was
originally associated with a read lock, or with a file that was
originally opened for read, but has since been upgraded.

So, when checking the openmode, check the mode associated with the
open stateid from which the lock was derived.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Move more work into helper functions.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The delegation code mostly pretends to support either read or write
delegations.  However, correct support for write delegations would
require, for example, breaking of delegations (and/or implementation of
cb_getattr) on stat.  Currently all that stops us from handing out
delegations is a subtle reference-counting issue.

Avoid confusion by adding an earlier check that explicitly refuses write
delegations.

For now, though, I'm not going so far as to rip out existing
half-support for write delegations, in case we get around to using that
soon.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If someone tries to shut down the laundry_wq while it isn't up it'll
cause an oops.

This can happen because write_ports can create a nfsd_svc before we
really start the nfs server, and we may fail before the server is ever
started.

Also make sure state is shutdown on error paths in nfsd_svc().

Use a common global nfsd_up flag instead of nfs4_init, and create common
helper functions for nfsd start/shutdown, as there will be other work
that we want done only when we the number of nfsd threads transitions
between zero and nonzero.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>