linux.git/fs/lockd, branch v2.6.29-rc2

NLM: Clean up flow of control in make_socks() function

2009-01-07T20:40:44+00:00

Clean up: Use Bruce's preferred control flow style in make_socks().

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

NLM: Refactor make_socks() function

2009-01-07T20:40:44+00:00

Clean up: extract common logic in NLM's make_socks() function
into a helper.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

lockd: Enable NLM use of AF_INET6

2009-01-06T16:53:56+00:00

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 
Cc: Aime Le Rouzic 
Signed-off-by: J. Bruce Fields

NSM: Move nsm_create()

2009-01-06T16:53:56+00:00

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 
Signed-off-by: J. Bruce Fields

NSM: Move nsm_use_hostnames to mon.c

2009-01-06T16:53:55+00:00

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 
Signed-off-by: J. Bruce Fields

NSM: Move nsm_addr() to fs/lockd/mon.c

2009-01-06T16:53:55+00:00

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 
Signed-off-by: J. Bruce Fields

NSM: Remove include/linux/lockd/sm_inter.h

2009-01-06T16:53:55+00:00

Clean up: The include/linux/lockd/sm_inter.h header is nearly empty
now.  Remove it.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

NSM: Replace IP address as our nlm_reboot lookup key

2009-01-06T16:53:55+00:00

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 
Signed-off-by: J. Bruce Fields

NSM: More clean up of nsm_get_handle()

2009-01-06T16:53:55+00:00

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 
Signed-off-by: J. Bruce Fields

NSM: Refactor nsm_handle creation into a helper function

2009-01-06T16:53:55+00:00

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 
Signed-off-by: J. Bruce Fields