Commit Graph

300 Commits

Author SHA1 Message Date
Alexey Dobriyan 405f55712d headers: smp_lock.h redux
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
  It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

  This will make hardirq.h inclusion cheaper for every PREEMPT=n config
  (which includes allmodconfig/allyesconfig, BTW)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-12 12:22:34 -07:00
Linus Torvalds 7e0338c0de Merge branch 'for-2.6.31' of git://fieldses.org/git/linux-nfsd
* 'for-2.6.31' of git://fieldses.org/git/linux-nfsd: (60 commits)
  SUNRPC: Fix the TCP server's send buffer accounting
  nfsd41: Backchannel: minorversion support for the back channel
  nfsd41: Backchannel: cleanup nfs4.0 callback encode routines
  nfsd41: Remove ip address collision detection case
  nfsd: optimise the starting of zero threads when none are running.
  nfsd: don't take nfsd_mutex twice when setting number of threads.
  nfsd41: sanity check client drc maxreqs
  nfsd41: move channel attributes from nfsd4_session to a nfsd4_channel_attr struct
  NFS: kill off complicated macro 'PROC'
  sunrpc: potential memory leak in function rdma_read_xdr
  nfsd: minor nfsd_vfs_write cleanup
  nfsd: Pull write-gathering code out of nfsd_vfs_write
  nfsd: track last inode only in use_wgather case
  sunrpc: align cache_clean work's timer
  nfsd: Use write gathering only with NFSv2
  NFSv4: kill off complicated macro 'PROC'
  NFSv4: do exact check about attribute specified
  knfsd: remove unreported filehandle stats counters
  knfsd: fix reply cache memory corruption
  knfsd: reply cache cleanups
  ...
2009-06-22 12:55:50 -07:00
Chuck Lever 0e5c2632e1 lockd: Don't bother with RPC ping for NSM upcalls
Cut NSM upcall RPC traffic in half -- don't do a NULL call first.
The cases where a ping would be helpful are rare.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-06-17 18:02:11 -07:00
Chuck Lever 6c9dc42551 lockd: Update NSM state from SM_MON replies
When rpc.statd starts up in user space at boot time, it attempts to
write the latest NSM local state number into
/proc/sys/fs/nfs/nsm_local_state.

If lockd.ko isn't loaded yet (as is the case in most configurations),
that file doesn't exist, thus the kernel's NSM state remains set to
its initial value of zero during lockd operation.

This is a problem because rpc.statd and lockd use the NSM state number
to prevent repeated lock recovery on rebooted hosts.  If lockd sends
a zero NSM state, but then a delayed SM_NOTIFY with a real NSM state
number is received, there is no way for lockd or rpc.statd to
distinguish that stale SM_NOTIFY from an actual reboot.  Thus lock
recovery could be performed after the rebooted host has already
started reclaiming locks, and those locks will be lost.

We could change /etc/init.d/nfslock so it always modprobes lockd.ko
before starting rpc.statd.  However, if lockd.ko is ever unloaded
and reloaded, we are back at square one, since the NSM state is not
preserved across an unload/reload cycle.  This may happen frequently
on clients that use automounter.  A period of NFS inactivity causes
lockd.ko to be unloaded, and the kernel loses its NSM state setting.

Instead, let's use the fact that rpc.statd plants the local system's
NSM state in every SM_MON (and SM_UNMON) reply.  lockd performs a
synchronous SM_MON upcall to the local rpc.statd _before_ sending its
first NLM request to a new remote.  This would permit rpc.statd to
provide the current NSM state to lockd, even after lockd.ko had been
unloaded and reloaded.

Note that NLMPROC_LOCK arguments are constructed before the
nsm_monitor() call, so we have to rearrange argument construction very
slightly to make this all work out.

And, the kernel appears to treat NSM state as a u32 (see struct
nlm_args and nsm_res).  Make nsm_local_state a u32 as well, to ensure
we don't get bogus comparison results.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-06-17 18:02:10 -07:00
Trond Myklebust 5cd973c44a NFSv4/NLM: Push file locking BKL dependencies down into the NLM layer
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-06-17 13:23:01 -07:00
J. Bruce Fields 7eef4091a6 Merge commit 'v2.6.30' into for-2.6.31 2009-06-15 18:08:07 -07:00
J. Bruce Fields 89996df4b5 lockd: fix list corruption on lockd restart
If lockd is signalled soon enough after restart then locks_start_grace()
will try to re-add an entry to a list and trigger a lock corruption
warning.

Thanks to Wang Chen for the problem report and diagnosis.

WARNING: at lib/list_debug.c:26 __list_add+0x27/0x5c()
...
list_add corruption. next->prev should be prev (ef8fe958), but was ef8ff128.  (next=ef8ff128).
...
Pid: 23062, comm: lockd Tainted: G        W  2.6.30-rc2 #3
Call Trace:
[<c042d5b5>] warn_slowpath+0x71/0xa0
[<c0422a96>] ? update_curr+0x11d/0x125
[<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
[<c044b270>] ? trace_hardirqs_on+0xb/0xd
[<c051c61a>] ? _raw_spin_lock+0x53/0xfa
[<c051c89f>] __list_add+0x27/0x5c
[<ef8f6daa>] locks_start_grace+0x22/0x30 [lockd]
[<ef8f34da>] set_grace_period+0x39/0x53 [lockd]
[<c06b8921>] ? lock_kernel+0x1c/0x28
[<ef8f3558>] lockd+0x64/0x164 [lockd]
[<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
[<c04227b0>] ? complete+0x34/0x3e
[<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
[<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
[<c043dd42>] kthread+0x45/0x6b
[<c043dcfd>] ? kthread+0x0/0x6b
[<c0403c23>] kernel_thread_helper+0x7/0x10

Reported-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: stable@kernel.org
2009-05-06 17:19:36 -04:00
Felix Blyakher a9e61e25f9 lockd: call locks_release_private to cleanup per-filesystem state
For every lock request lockd creates a new file_lock object
in nlmsvc_setgrantargs() by copying the passed in file_lock with
locks_copy_lock(). A filesystem can attach it's own lock_operations
vector to the file_lock. It has to be cleaned up at the end of the
file_lock's life. However, lockd doesn't do it today, yet it
asserts in nlmclnt_release_lockargs() that the per-filesystem
state is clean.
This patch fixes it by exporting locks_release_private() and adding
it to nlmsvc_freegrantargs(), to be symmetrical to creating a
file_lock in nlmsvc_setgrantargs().

Signed-off-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-04-24 16:36:03 -04:00
Linus Torvalds a63856252d Merge branch 'for-2.6.30' of git://linux-nfs.org/~bfields/linux
* 'for-2.6.30' of git://linux-nfs.org/~bfields/linux: (81 commits)
  nfsd41: define nfsd4_set_statp as noop for !CONFIG_NFSD_V4
  nfsd41: define NFSD_DRC_SIZE_SHIFT in set_max_drc
  nfsd41: Documentation/filesystems/nfs41-server.txt
  nfsd41: CREATE_EXCLUSIVE4_1
  nfsd41: SUPPATTR_EXCLCREAT attribute
  nfsd41: support for 3-word long attribute bitmask
  nfsd: dynamically skip encoded fattr bitmap in _nfsd4_verify
  nfsd41: pass writable attrs mask to nfsd4_decode_fattr
  nfsd41: provide support for minor version 1 at rpc level
  nfsd41: control nfsv4.1 svc via /proc/fs/nfsd/versions
  nfsd41: add OPEN4_SHARE_ACCESS_WANT nfs4_stateid bmap
  nfsd41: access_valid
  nfsd41: clientid handling
  nfsd41: check encode size for sessions maxresponse cached
  nfsd41: stateid handling
  nfsd: pass nfsd4_compound_state* to nfs4_preprocess_{state,seq}id_op
  nfsd41: destroy_session operation
  nfsd41: non-page DRC for solo sequence responses
  nfsd41: Add a create session replay cache
  nfsd41: create_session operation
  ...
2009-04-06 13:25:56 -07:00
Mans Rullgard ad5b365c12 NSM: Fix unaligned accesses in nsm_init_private()
This fixes unaligned accesses in nsm_init_private() when
creating nlm_reboot keys.

Signed-off-by: Mans Rullgard <mans@mansr.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-04-01 13:24:14 -04:00
Chuck Lever eb16e90778 lockd: Start PF_INET6 listener only if IPv6 support is available
Apparently a lot of people need to disable IPv6 completely on their
distributor-built systems, which have CONFIG_IPV6_MODULE enabled at
build time.

They do this by blacklisting the ipv6.ko module.  This causes the
creation of the lockd service listener to fail if CONFIG_IPV6_MODULE
is set, but the module cannot be loaded.

Now that the kernel's PF_INET6 RPC listeners are completely separate
from PF_INET listeners, we can always start PF_INET.  Then lockd can
try to start PF_INET6, but it isn't required to be available.

Note this has the added benefit that NLM callbacks from AF_INET6
servers will never come from AF_INET remotes.  We no longer have to
worry about matching mapped IPv4 addresses to AF_INET when comparing
addresses.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-03-28 16:01:16 -04:00
Chuck Lever 26298caaca NFS: Revert creation of IPv6 listeners for lockd and NFSv4 callbacks
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: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-03-28 15:55:06 -04:00
Chuck Lever 49a9072f29 SUNRPC: Remove @family argument from svc_create() and svc_create_pooled()
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: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-03-28 15:54:48 -04:00
Chuck Lever 9652ada3fb SUNRPC: Change svc_create_xprt() to take a @family argument
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: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-03-28 15:54:36 -04:00
Miklos Szeredi e33d1ea60c lockd: clean up blocking lock cases of nlsmvc_lock()
No change in behavior, just rearranging the switch so that we break out
of the switch if and only if we're in the wait case.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-03-18 17:30:50 -04:00
Chuck Lever 57df675c60 NLM: Fix GRANT callback address comparison when IPv6 is enabled
The NFS mount command may pass an AF_INET server address to lockd.  If
lockd happens to be using a PF_INET6 listener, the nlm_cmp_addr() in
nlmclnt_grant() will fail to match requests from that host because they
will all have a mapped IPv4 AF_INET6 address.

Adopt the same solution used in nfs_sockaddr_match_ipaddr() for NFSv4
callbacks: if either address is AF_INET, map it to an AF_INET6 address
before doing the comparison.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-03-10 20:33:20 -04:00
J. Bruce Fields 9d9b87c121 lockd: fix regression in lockd's handling of blocked locks
If a client requests a blocking lock, is denied, then requests it again,
then here in nlmsvc_lock() we will call vfs_lock_file() without FL_SLEEP
set, because we've already queued a block and don't need the locks code
to do it again.

But that means vfs_lock_file() will return -EAGAIN instead of
FILE_LOCK_DENIED.  So we still need to translate that -EAGAIN return
into a nlm_lck_blocked error in this case, and put ourselves back on
lockd's block list.

The bug was introduced by bde74e4bc6 "locks: add special return
value for asynchronous locks".

Thanks to Frank van Maarseveen for the report; his original test
case was essentially

	for i in `seq 30`; do flock /nfsmount/foo sleep 10 & done

Tested-by: Frank van Maarseveen <frankvm@frankvm.com>
Reported-by: Frank van Maarseveen <frankvm@frankvm.com>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-02-09 13:19:46 -05:00
Chuck Lever 0dba7c2a9e NLM: Clean up flow of control in make_socks() function
Clean up: Use Bruce's preferred control flow style in make_socks().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-07 15:40:44 -05:00
Chuck Lever d3fe5ea7cf NLM: Refactor make_socks() function
Clean up: extract common logic in NLM's make_socks() function
into a helper.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-07 15:40:44 -05:00
Chuck Lever b064ec038a lockd: Enable NLM use of AF_INET6
If the kernel is configured to support IPv6 and the RPC server can register
services via rpcbindv4, we are all set to enable IPv6 support for lockd.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aime Le Rouzic <aime.le-rouzic@bull.net>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:56 -05:00
Chuck Lever 49b5699b3f NSM: Move nsm_create()
Clean up: one last thing... relocate nsm_create() to eliminate the forward
declaration and group it near the only function that actually uses it.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:56 -05:00
Chuck Lever b7ba597fb9 NSM: Move nsm_use_hostnames to mon.c
Clean up.

Treat the nsm_use_hostnames global variable like nsm_local_state.
Note that the default value of nsm_use_hostnames is still zero.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:55 -05:00
Chuck Lever 8529bc51d3 NSM: Move nsm_addr() to fs/lockd/mon.c
Clean up: nsm_addr_in() is no longer used, and nsm_addr() is used only in
fs/lockd/mon.c, so move it there.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:55 -05:00
Chuck Lever e6765b8397 NSM: Remove include/linux/lockd/sm_inter.h
Clean up: The include/linux/lockd/sm_inter.h header is nearly empty
now.  Remove it.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:55 -05:00
Chuck Lever 94da7663db NSM: Replace IP address as our nlm_reboot lookup key
NLM provides file locking services for NFS files.  Part of this service
includes a second protocol, known as NSM, which is a reboot
notification service.  NLM uses this service to determine when to
reclaim locks or enter a grace period after a client or server reboots.

The NLM service (implemented by lockd in the Linux kernel) contacts
the local NSM service (implemented by rpc.statd in Linux user space)
via NSM protocol upcalls to register a callback when a particular
remote peer reboots.

To match the callback to the correct remote peer, the NLM service
constructs a cookie that it passes in the request.  The NSM service
passes that cookie back to the NLM service when it is notified that
the given remote peer has indeed rebooted.

Currently on Linux, the cookie is the raw 32-bit IPv4 address of the
remote peer.  To support IPv6 addresses, which are larger, we could
use all 16 bytes of the cookie to represent a full IPv6 address,
although we still can't represent an IPv6 address with a scope ID in
just 16 bytes.

Instead, to avoid the need for future changes to support additional
address types, we'll use a manufactured value for the cookie, and use
that to find the corresponding nsm_handle struct in the kernel during
the NLMPROC_SM_NOTIFY callback.

This should provide complete support in the kernel's NSM
implementation for IPv6 hosts, while remaining backwards compatible
with older rpc.statd implementations.

Note we also deal with another case where nsm_use_hostnames can change
while there are outstanding notifications, possibly resulting in the
loss of reboot notifications.  After this patch, the priv cookie is
always used to lookup rebooted hosts in the kernel.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:55 -05:00
Chuck Lever 77a3ef33e2 NSM: More clean up of nsm_get_handle()
Clean up: refactor nsm_get_handle() so it is organized the same way that
nsm_reboot_lookup() is.

There is an additional micro-optimization here.  This change moves the
"hostname & nsm_use_hostnames" test out of the list_for_each_entry()
clause in nsm_get_handle(), since it is loop-invariant.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:55 -05:00
Chuck Lever b39b897c25 NSM: Refactor nsm_handle creation into a helper function
Clean up.  Refactor the creation of nsm_handles into a helper.  Fields
are initialized in increasing address order to make efficient use of
CPU caches.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:55 -05:00
Chuck Lever 92fd91b998 NLM: Remove "create" argument from nsm_find()
Clean up: nsm_find() now has only one caller, and that caller
unconditionally sets the @create argument. Thus the @create
argument is no longer needed.

Since nsm_find() now has a more specific purpose, pick a more
appropriate name for it.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:54 -05:00
Chuck Lever 8c7378fd2a NLM: Call nsm_reboot_lookup() instead of nsm_find()
Invoke the newly introduced nsm_reboot_lookup() function in
nlm_host_rebooted() instead of nsm_find().

This introduces just one behavioral change: debugging messages
produced during reboot notification will now appear when the
NLMDBG_MONITOR flag is set, but not when the NLMDBG_HOSTCACHE flag
is set.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:54 -05:00
Chuck Lever 3420a8c435 NSM: Add nsm_lookup() function
Introduce a new API to fs/lockd/mon.c that allows nlm_host_rebooted()
to lookup up nsm_handles via the contents of an nlm_reboot struct.

The new function is equivalent to calling nsm_find() with @create set
to zero, but it takes a struct nlm_reboot instead of separate
arguments.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:54 -05:00
Chuck Lever 576df4634e NLM: Decode "priv" argument of NLMPROC_SM_NOTIFY as an opaque
The NLM XDR decoders for the NLMPROC_SM_NOTIFY procedure should treat
their "priv" argument truly as an opaque, as defined by the protocol,
and let the upper layers figure out what is in it.

This will make it easier to modify the contents and interpretation of
the "priv" argument, and keep knowledge about what's in "priv" local
to fs/lockd/mon.c.

For now, the NLM and NSM implementations should behave exactly as they
did before.

The formation of the address of the rebooted host in
nlm_host_rebooted() may look a little strange, but it is the inverse
of how nsm_init_private() forms the private cookie.  Plus, it's
going away soon anyway.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:54 -05:00
Chuck Lever 7fefc9cb9d NLM: Change nlm_host_rebooted() to take a single nlm_reboot argument
Pass the nlm_reboot data structure directly from the NLMPROC_SM_NOTIFY
XDR decoders to nlm_host_rebooted().  This eliminates some packing and
unpacking of the NLMPROC_SM_NOTIFY results, and prepares for passing
these results, including the "priv" cookie, directly to a lookup
routine in fs/lockd/mon.c.

This patch changes code organization but should not cause any
behavioral change.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:54 -05:00
Chuck Lever cab2d3c991 NSM: Encode the new "priv" cookie for NSMPROC_MON requests
Pass the new "priv" cookie to NSMPROC_MON's XDR encoder, instead of
creating the "priv" argument in the encoder at call time.

This patch should not cause a behavioral change: the contents of the
cookie remain the same for the time being.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:54 -05:00
Chuck Lever 7e44d3bea2 NSM: Generate NSMPROC_MON's "priv" argument when nsm_handle is created
Introduce a new data type, used by both the in-kernel NLM and NSM
implementations, that is used to manage the opaque "priv" argument
for the NSMPROC_MON and NLMPROC_SM_NOTIFY calls.

Construct the "priv" cookie when the nsm_handle is created.

The nsm_init_private() function may look a little strange, but it is
roughly equivalent to how the XDR encoder formed the "priv" argument.
It's going to go away soon.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:53 -05:00
Chuck Lever 05f3a9af58 NSM: Remove !nsm check from nsm_release()
The nsm_release() function should never be called with a NULL handle
point.  If it is, that's a bug.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:53 -05:00
Chuck Lever bc1cc6c4e4 NSM: Remove NULL pointer check from nsm_find()
The nsm_find() function should never be called with a NULL IP address
pointer.  If it is, that's a bug.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:53 -05:00
Chuck Lever 5cf1c4b19d NSM: Add dprintk() calls in nsm_find and nsm_release
Introduce some dprintk() calls in fs/lockd/mon.c that are enabled by
the NLMDBG_MONITOR flag.  These report when we find, create, and
release nsm_handles.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:53 -05:00
Chuck Lever 67c6d107a6 NSM: Move nsm_find() to fs/lockd/mon.c
The nsm_find() function sets up fresh nsm_handle entries.  This is
where we will store the "priv" cookie used to lookup nsm_handles during
reboot recovery.  The cookie will be constructed when nsm_find()
creates a new nsm_handle.

As much as possible, I would like to keep everything that handles a
"priv" cookie in fs/lockd/mon.c so that all the smarts are in one
source file.  That organization should make it pretty simple to see how
all this works.

To me, it makes more sense than the current arrangement to keep
nsm_find() with nsm_monitor() and nsm_unmonitor().

So, start reorganizing by moving nsm_find() into fs/lockd/mon.c.  The
nsm_release() function comes along too, since it shares the nsm_lock
global variable.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:53 -05:00
Chuck Lever 03eb1dcbb7 NSM: move to xdr_stream-based XDR encoders and decoders
Introduce xdr_stream-based XDR encoder and decoder functions, which are
more careful about preventing RPC buffer overflows.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:53 -05:00
Chuck Lever 36e8e668d3 NSM: Move NSM program and procedure numbers to fs/lockd/mon.c
Clean up: Move the RPC program and procedure numbers for NSM into the
one source file that needs them: fs/lockd/mon.c.

And, as with NLM, NFS, and rpcbind calls, use NSMPROC_FOO instead of
SM_FOO for NSM procedure numbers.

Finally, make a couple of comments more precise: what is referred to
here as SM_NOTIFY is really the NLM (lockd) NLMPROC_SM_NOTIFY downcall,
not NSMPROC_NOTIFY.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:52 -05:00
Chuck Lever 9c1bfd037f NSM: Move NSM-related XDR data structures to lockd's xdr.h
Clean up: NSM's XDR data structures are used only in fs/lockd/mon.c,
so move them there.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:52 -05:00
Chuck Lever 0c7aef4569 NSM: Check result of SM_UNMON upcall
Make sure any error returned by rpc.statd during an SM_UNMON call is
reported rather than ignored completely.  There isn't much to do with
such an error, but we should log it in any case.

Similar to a recent change to nsm_monitor().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:52 -05:00
Chuck Lever 356c3eb466 NLM: Move the public declaration of nsm_unmonitor() to lockd.h
Clean up.

Make the nlm_host argument "const," and move the public declaration to
lockd.h.  Add a documenting comment.

Bruce observed that nsm_unmonitor()'s only caller doesn't care about
its return code, so make nsm_unmonitor() return void.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:52 -05:00
Chuck Lever c8c23c423d NSM: Release nsmhandle in nlm_destroy_host
The nsm_handle's reference count is bumped in nlm_lookup_host().  It
should be decremented in nlm_destroy_host() to make it easier to see
the balance of these two operations.

Move the nsm_release() call to fs/lockd/host.c.

The h_nsmhandle pointer is set in nlm_lookup_host(), and never cleared.
The nlm_destroy_host() function is never called for the same nlm_host
twice, so h_nsmhandle won't ever be NULL when nsm_unmonitor() is
called.

All references to the nlm_host are gone before it is freed.  We can
skip making h_nsmhandle NULL just before the nlm_host is deallocated.

It's also likely we can remove the h_nsmhandle NULL check in
nlmsvc_is_client() as well, but we can do that later when rearchitect-
ing the nlm_host cache.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:52 -05:00
Chuck Lever 1e49323c4a NLM: Move the public declaration of nsm_monitor() to lockd.h
Clean up.

Make the nlm_host argument "const," and move the public declaration to
lockd.h with other NSM public function (nsm_release, eg) and global
variable declarations.

Add a documenting comment.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:52 -05:00
Chuck Lever 5d254b1198 NSM: Make sure to return an error if the SM_MON call result is not zero
The nsm_monitor() function reports an error and does not set sm_monitored
if the SM_MON upcall reply has a non-zero result code, but nsm_monitor()
does not return an error to its caller in this case.

Since sm_monitored is not set, the upcall is retried when the next NLM
request invokes nsm_monitor().  However, that may not come for a while.
In the meantime, at least one NLM request will potentially proceed
without the peer being monitored properly.

Have nsm_monitor() return an error if the result code is non-zero.
This will cause all NLM requests to fail immediately if the upcall
completed successfully but rpc.statd returned an error.

This may be inconvenient in some cases (for example if rpc.statd
cannot complete a proper DNS reverse lookup of the hostname), but will
make the reboot monitoring service more robust by forcing such issues
to be corrected by an admin.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:51 -05:00
Chuck Lever 5bc74bef7c NSM: Remove BUG_ON() in nsm_monitor()
Clean up: Remove the BUG_ON() invocation in nsm_monitor().  It's not
likely that nsm_monitor() is ever called with a NULL host pointer, and
the code will die anyway if host is NULL.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:51 -05:00
Chuck Lever 501c1ed3fb NLM: Remove redundant printk() in nlmclnt_lock()
The nsm_monitor() function already generates a printk(KERN_NOTICE) if
the SM_MON upcall fails, so the similar printk() in the nlmclnt_lock()
function is redundant.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:51 -05:00
Chuck Lever 9fee49024e NSM: Use sm_name instead of h_name in nsm_monitor() and nsm_unmonitor()
Clean up: Use the sm_name field for reporting the hostname in nsm_monitor()
and nsm_unmonitor(), just as the other functions in fs/lockd/mon.c do.

The h_name field is just a copy of the sm_name pointer.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:51 -05:00
Chuck Lever 29ed1407ed NSM: Support IPv6 version of mon_name
The "mon_name" argument of the NSMPROC_MON and NSMPROC_UNMON upcalls
is a string that contains the hostname or IP address of the remote peer
to be notified when this host has rebooted.  The sm-notify command uses
this identifier to contact the peer when we reboot, so it must be
either a well-qualified DNS hostname or a presentation format IP
address string.

When the "nsm_use_hostnames" sysctl is set to zero, the kernel's NSM
provides a presentation format IP address in the "mon_name" argument.
Otherwise, the "caller_name" argument from NLM requests is used,
which is usually just the DNS hostname of the peer.

To support IPv6 addresses for the mon_name argument, we use the
nsm_handle's address eye-catcher, which already contains an appropriate
presentation format address string.  Using the eye-catcher string
obviates the need to use a large buffer on the stack to form the
presentation address string for the upcall.

This patch also addresses a subtle bug.

An NSMPROC_MON request and the subsequent NSMPROC_UNMON request for the
same peer are required to use the same value for the "mon_name"
argument.  Otherwise, rpc.statd's NSMPROC_UNMON processing cannot
locate the database entry for that peer and remove it.

If the setting of nsm_use_hostnames is changed between the time the
kernel sends an NSMPROC_MON request and the time it sends the
NSMPROC_UNMON request for the same peer, the "mon_name" argument for
these two requests may not be the same.  This is because the value of
"mon_name" is currently chosen at the moment the call is made based on
the setting of nsm_use_hostnames

To ensure both requests pass identical contents in the "mon_name"
argument, we now select which string to use for the argument in the
nsm_monitor() function.  A pointer to this string is saved in the
nsm_handle so it can be used for a subsequent NSMPROC_UNMON upcall.

NB: There are other potential problems, such as how nlm_host_rebooted()
might behave if nsm_use_hostnames were changed while hosts are still
being monitored.  This patch does not attempt to address those
problems.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06 11:53:51 -05:00