If we set up to wait for a cache item to be filled in, and then find
that it is no longer pending, it could be that some other thread is
in 'cache_revisit_request' and has moved our request to its 'pending' list.
So when our setup_deferral calls cache_revisit_request it will find nothing to
put on the pending list, and do nothing.

We then return from cache_wait_req, thus leaving the 'sleeper'
on-stack structure open to being corrupted by subsequent stack usage.

However that 'sleeper' could still be on the 'pending' list that the
other thread is looking at and so any corruption could cause it to behave badly.

To avoid this race we simply take the same path as if the
'wait_for_completion_interruptible_timeout' was interrupted and if the
sleeper is no longer on the list (which it won't be) we wait on the
completion - which will ensure that any other cache_revisit_request
will have let go of the sleeper.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The context is already known in all the sock_create callers.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The net is known from the xprt_create and this tagging will also
give un the context in the conntection workers where real sockets
are created.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

After this the socket creation in it knows the context.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The existing code adjusted it based on the worst case scenario for the returned
bitmap and the best case scenario for the supported attrs attribute.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[bfields@redhat.com: removed likely/unlikely's]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

On Wed, 29 Sep 2010 14:02:38 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> After merging the final tree, today's linux-next build (powerpc
> ppc44x_defconfig) produced tis warning:
>
> WARNING: net/sunrpc/sunrpc.o(.init.text+0x110): Section mismatch in reference from the function init_sunrpc() to the function .exit.text:rpcauth_remove_module()
> The function __init init_sunrpc() references
> a function __exit rpcauth_remove_module().
> This is often seen when error handling in the init function
> uses functionality in the exit path.
> The fix is often to remove the __exit annotation of
> rpcauth_remove_module() so it may be used outside an exit section.
>
> Probably caused by commit 2f72c9b7
> ("sunrpc: The per-net skeleton").

This actually causes a build failure on a sparc32 defconfig build:

`rpcauth_remove_module' referenced in section `.init.text' of net/built-in.o: defined in discarded section `.exit.text' of net/built-in.o

I applied the following patch for today:

Fixes:

`rpcauth_remove_module' referenced in section `.init.text' of net/built-in.o: defined in discarded section `.exit.text' of net/built-in.o
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Everything that is required for that already exists:
* the per-net cache registration with respective proc entries
* the context (struct net) is available in all the users
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Register empty per-net operations for the sunrpc layer.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The transport representation should be per-net of course.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Existing calls do the same, but for the init_net.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

There are two calls that operate on ip_map_cache and are
directly called from the nfsd code. Other places will be
handled in a different way.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

They do not require the rqst actually and having the xprt simplifies
further patching.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

This is done in order to facilitate getting the ip_map_cache from
which to put the ip_map.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The target is to have many ip_map_cache-s in the system. This particular
patch handles its usage by the ip_map_parse callback.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Note with "first" always 0, and "lastflags" initially 0, we always dump
a spurious set of 0 flags at the start, among other problems.

Fix.  And attempt to make the code a little more obvious.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The git://linux-nfs.org/~bfields/linux.git nfsd-next branch doesn't
compile when nfsd is a module with the following error:

   ERROR: "get_task_comm" [fs/nfsd/nfsd.ko] undefined!

Replace the get_task_comm call with direct comm access, which is
safe for current.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Add CONFIG_NFSD_DEPRECATED, default to y.
Only include deprecated interface if this is defined.
This allows distros to remove this interface before the official
removal, and allows developers to test without it.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The syscall interface is has been replaced by a more flexible
interface since 2.6.0.  It is time to work towards discarding
the old interface.

So add a entry in feature-removal-schedule.txt and print a warning
when the interface is used.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

commit 6610f720
broke cache_clean_deferred as entries are no longer added to the
pending list for subsequent revisiting.

So put those requests back on the pending list.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

This patch removes all but one call to lock_kernel() from the server.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Being a hash table, hlist is the best option.

There is currently some ugliness were we treat "->next == NULL" as
a special case to avoid having to initialise the whole array.
This change nicely gets rid of that case.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Code like:

  switch(xxx) {
  case -error1:
  case -error2:
     ..
     return;
  case 0:
     stuff;
  }

  can more naturally be written:

  if (xxx < 0)
      return;

  stuff;
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The idmap code manages request deferal by waiting for a reply from
userspace rather than putting the NFS request on a queue to be retried
from the start.
Now that the common deferal code does this there is no need for the
special code in idmap.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Now that a slight delay in getting a reply to an upcall doesn't
require deferring of requests, request deferral for all NFSv4
requests - the concept doesn't really fit with the v4 model.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

If we drop a request in the sunrpc layer, either due kmalloc failure,
or due to a cache miss when we could not queue the request for later
replay, then close the connection to encourage the client to retry sooner.

Note that if the drop happens in the NFS layer, NFSERR_JUKEBOX
(aka NFS4ERR_DELAY) is returned to guide the client concerning
replay.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The last_close field of a cache_detail is initialized to zero, so the
condition

	detail->last_close < seconds_since_boot() - 30

may be false even for a cache that was never opened.

However, we want to immediately fail upcalls to caches that were never
opened: in the case of the auth_unix_gid cache, especially, which may
never be opened by mountd (if the --manage-gids option is not set), we
want to fail the upcall immediately.  Otherwise client requests will be
dropped unnecessarily on reboot.

Also document these conditions.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Without some client-side fixes, server testing is currently difficult.

The NFSv4 client's callback server calls svc_gss_principal(), which
is defined in the auth_rpcgss.ko

The NFSv4 server has the same dependency, and in addition calls
svcauth_gss_flavor(), gss_mech_get_by_pseudoflavor(),
gss_pseudoflavor_to_service() and gss_mech_put() from the same module.

The module auth_rpcgss itself has no dependencies aside from sunrpc,
so we only need to select RPCSEC_GSS.
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Hi,

An NFS client executes a statfs("file", &buff) call.
"file" exists / existed, the client has read / written it,
but it has already closed it.

user_path(pathname, &path) looks up "file" successfully in the
directory-cache  and restarts the aging timer of the directory-entry.
Even if "file" has already been removed from the server, because the
lookupcache=positive option I use, keeps the entries valid for a while.

nfs_statfs() returns ESTALE if "file" has already been removed from the
server.

If the user application repeats the statfs("file", &buff) call, we
are stuck: "file" remains young forever in the directory-cache.
Signed-off-by: Zoltan Menyhart  <Zoltan.Menyhart@bull.net>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

Reported-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

The maximum size of the authcache is now set to 1024 (10 bits),
but on our server we need at least 4096 (12 bits). Increase
MAX_HASHTABLE_BITS to 14. This is a maximum of 16384 entries,
each containing a pointer (8 bytes on x86_64). This is
exactly the limit of kmalloc() (128K).
Signed-off-by: Miquel van Smoorenburg <mikevs@xs4all.net>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

spkm3 miss returning error to up layer when import security context,
it may be return ok though it has failed to import security context.
Signed-off-by: Bian Naimeng <biannm@cn.fujitsu.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>