My understanding is that there is a push to turn the kernel_thread
interface into a non-exported symbol and move all kernel threads to use
the kthread API. This patch changes lockd to use kthread_run to spawn
the reclaimer thread.

I've made the assumption here that the extra module references taken
when we spawn this thread are unnecessary and removed them. I've also
added a KERN_ERR printk that pops if the thread can't be spawned to warn
the admin that the locks won't be reclaimed.

In the future, it would be nice to be able to notify userspace that
locks have been lost (probably by implementing SIGLOST), and adding some
good policies about how long we should reattempt to reclaim the locks.

Finally, I removed a comment about memory leaks that I believe is
obsolete and added a new one to clarify the result of sending a SIGKILL
to the reclaimer thread. As best I can tell, doing so doesn't actually
cause a memory leak.

I consider this patch 2.6.29 material.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: Now that lockd_up() starts listeners for both transports, the
"proto" argument is no longer needed.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Adjust the signature and callers of nlmclnt_grant() to pass a "struct
sockaddr *" instead of a "struct sockaddr_in *" in order to support IPv6
addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Pass a struct sockaddr * and a length to nlmclnt_lookup_host() to
accomodate non-AF_INET family addresses.

As a side benefit, eliminate the hostname_len argument, as the hostname
is always NUL-terminated.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Update the nlm_cmp_addr() helper to support AF_INET6 as well as AF_INET
addresses.  New version takes two "struct sockaddr *" arguments instead of
"struct sockaddr_in *" arguments.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

To store larger addresses in the nlm_host structure, make h_addr a
sockaddr_storage, and add an address length field.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Clean up: pass 5 arguments to nlmclnt_init() in a structure similar to the
new nfs_client_initdata structure.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

We would like to remove the per-lock-operation nlm_lookup_host() call from
nlmclnt_proc().

The new architecture pins an nlm_host structure to each NFS client
superblock that has the "lock" mount option set.  The NFS client passes
in the pinned nlm_host structure during each call to nlmclnt_proc().  NFS
client unmount processing "puts" the nlm_host so it can be garbage-
collected later.

This patch introduces externally callable NLM functions that handle
mount-time nlm_host set up and tear-down.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

reclaimer() calls allow_signal() which plays with parent process's ->sighand.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This patch adds missing newlines to dprintk's.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Annotated, all places switched to keeping status net-endian.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NJosef Sipek <jsipek@fsl.cs.sunysb.edu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NTrond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

nlmclnt_recovery would try to force a portmap rebind by setting
host->h_nextrebind to 0.  The right thing to do here is to set it to the
current time.
Signed-off-by: NOlaf Kirch <okir@suse.de>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch makes the SM_NOTIFY handling understand and use the nsm_handle.

To make it a bit clear what is happening:

    nlmclent_prepare_reclaim and nlmclnt_finish_reclaim
    get open-coded into 'reclaimer'

The result is tidied up.

Then some of that functionality is moved out into nlm_host_rebooted (which
calls nlmclnt_recovery which starts a thread which runs reclaimer).

Also host_rebooted now finds an nsm_handle rather than a host, then then
iterates over all hosts and deals with each host that shares that nsm_handle.
Signed-off-by: NOlaf Kirch <okir@suse.de>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch introduces the nsm_handle, which is shared by all nlm_host objects
referring to the same client.

With this patch applied, all nlm_hosts from the same address will share the
same nsm_handle.  A future patch will add sharing by name.

Note: this patch changes h_name so that it is no longer guaranteed to be an IP
address of the host.  When the host represents an NFS server, h_name will be
the name passed in the mount call.  When the host represents a client, h_name
will be the name presented in the lock request received from the client.  A
h_name is only used for printing informational messages, this change should
not be significant.
Signed-off-by: NOlaf Kirch <okir@suse.de>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If lockd_up fails - what should we expect?  Do we have to later call
lockd_down?

Well the nfs client thinks "no", the nfs server thinks "yes".  lockd thinks
"yes".

The only answer that really makes sense is "no" !!

So:
  Make lockd_up only increment  nlmsvc_users on success.
  Make nfsd handle errors from lockd_up properly.
  Make sure lockd_up(0) never fails when lockd is running
    so that the 'reclaimer' call to lockd_up doesn't need to
    be error checked.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently lockd listens on UDP always, and TCP if CONFIG_NFSD_TCP is set.

However as lockd performs services of the client as well, this is a problem.
If CONFIG_NfSD_TCP is not set, and a tcp mount is used, the server will not be
able to call back to lockd.

So:
 - add an option to lockd_up saying which protocol is needed
 - Always open sockets for which an explicit port was given, otherwise
   only open a socket of the type required
 - Change nfsd to do one lockd_up per socket rather than one per thread.

This
 - removes the dependancy on CONFIG_NFSD_TCP
 - means that lockd may open sockets other than at startup
 - means that lockd will *not* listen on UDP if the only
   mounts are TCP mount (and nfsd hasn't started).

The latter is the only one that concerns me at all - I don't know if this
might be a problem with some servers.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add missing \n to dprintk
Signed-off-by: NMartin Bligh <mbligh@google.com>
Acked-by: NTrond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently it is possible for a task to remove its locks at the same time as
the NLM recovery thread is trying to recover them. This quickly leads to an
Oops.
Protect the locks using an rw semaphore while they are being recovered.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

The patch "stop abusing file_lock_list introduces a couple of bugs since
the locks may be copied and need to be removed from the lists when they are
destroyed.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Currently lockd directly access the file_lock_list from fs/locks.c.
It does so to mark locks granted or reclaimable.  This is very
suboptimal, because a) lockd needs to poke into locks.c internals, and
b) it needs to iterate over all locks in the system for marking locks
granted or reclaimable.

This patch adds lists for granted and reclaimable locks to the nlm_host
structure instead, and adds locks to those.

nlmclnt_lock:
	now adds the lock to h_granted instead of setting the
	NFS_LCK_GRANTED, still O(1)

nlmclnt_mark_reclaim:
	goes away completely, replaced by a list_splice_init.
	Complexity reduced from O(locks in the system) to O(1)

reclaimer:
	iterates over h_reclaim now, complexity reduced from
	O(locks in the system) to O(locks per nlm_host)
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Instead we use the nlm_lockowner->pid.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If 2 threads attached to the same process are blocking on different locks on
different files (maybe even on different servers) but have the same lock
arguments (i.e.  same offset+length - actually quite common, since most
processes try to lock the entire file) then the first GRANTED call that wakes
one up will also wake the other.

Currently when the NLM_GRANTED callback comes in, lockd walks the list of
blocked locks in search of a match to the lock that the NLM server has
granted.  Although it checks the lock pid, start and end, it fails to check
the filehandle and the server address.

By checking the filehandle and server IP address, we ensure that this only
happens if the locks truly are referencing the same file.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

 When mixing -olock and -onolock mounts on the same client, we have to
 check that fl->fl_u.nfs_fl.owner is set before dereferencing it.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 If the lock blocks, the server may send us a GRANTED message that
 races with the reply to our LOCK request. Make sure that we catch
 the GRANTED by queueing up our request on the nlm_blocked list
 before we send off the first LOCK rpc call.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!