Make request_key() and co fundamentally asynchronous to make it easier for NFS

to make use of them.  There are now accessor functions that do asynchronous

constructions, a wait function to wait for construction to complete, and a

completion function for the key type to indicate completion of construction.
Note that the construction queue is now gone.  Instead, keys under construction

are linked in to the appropriate keyring in advance, and that anyone

encountering one must wait for it to be complete before they can use it.  This

is done automatically for userspace.
The following auxiliary changes are also made:
 (1) Key type implementation stuff is split from linux/key.h into

     linux/key-type.h.
 (2) AF_RXRPC provides a way to allocate null rxrpc-type keys so that AFS does

     not need to call key_instantiate_and_link() directly.
 (3) Documentation.
Signed-off-by: David Howells <dhowells@redhat.com>

---
 Documentation/keys-request-key.txt |   25 +-

 Documentation/keys.txt             |   91 +++++-

 Documentation/networking/rxrpc.txt |    7

 fs/afs/cell.c                      |   17 -

 include/keys/rxrpc-type.h          |    2

 include/linux/key-type.h           |  112 +++++++

 include/linux/key.h                |   99 +-----

 net/rxrpc/af_rxrpc.c               |    1

 net/rxrpc/ar-key.c                 |   31 ++

 security/keys/internal.h           |   29 +-

 security/keys/key.c                |   27 +-

 security/keys/process_keys.c       |   16 +

 security/keys/request_key.c        |  556 ++++++++++++++++++------------------

 security/keys/request_key_auth.c   |    9 +

 14 files changed, 595 insertions(+), 427 deletions(-)
diff --git a/Documentation/keys-request-key.txt b/Documentation/keys-request-key.txt

index c1f64fd..266955d 100644

--- a/Documentation/keys-request-key.txt

+++ b/Documentation/keys-request-key.txt

@@ -20,6 +20,19 @@ or:

 					     const char *callout_string,

 					     void *aux);
+or:

+

+	struct key *request_key_async(cons...
[ message continues ]

On Wed, 12 Sep 2007 15:25:08 +0100
So who's going to review this?  Nobody?  Well gee, maybe it was my turn

anyway.
How many different&private versions of this sort of thing do we have?  Sigh.
The debug infrastructure changes don't appear to be related to the intent
It'd be nice to add a comment explaining to the long-suffering reader why
You could actually use kstrdup() here, I think.
Apart from that the changes look reasonable to me, but I am not a suitable

reviewer for keys, NFS or rxrpc stuff.  Who is??
-

For this warning:
ERROR: need space after that ',' (ctx:WxV)

#627: FILE: security/keys/internal.h:28:

+#define kenter(FMT, ...) no_printk("==> %s("FMT")\n",__FUNCTION__ ,##__VA_ARGS__)
                                                                   ^
This is with good reason.  Some versions of cpp get the ## resolution "wrong"

if __VA_ARGS__ is empty (ie: there are no arguments to the macro that

correspond to the "...").  This can be worked around by abutting the "," the

"##" and the "__VA_ARGS__" with no spaces, and inserting a space before the

comma.
If I remember correctly, the comma won't be removed if it doesn't abut the

##__VA_ARGS__, and the comma and everthing that abuts it on its LHS can be

removed if there's also no space.  Without the "##", the comma isn't removed.
Consider the result of doing x("a"); where x(y, ...) is #defined to each of the

folowing:
	DEFINITION			RESULT

	===============================	=======================

	printk(y, __VA_ARGS__)		print(y, );

	printk(y ,__VA_ARGS__)		print(y ,);

	printk(y,##__VA_ARGS__)		print();

	printk(y, ##__VA_ARGS__)	print(y, );
I'll change the comment to:
	/* make sure no one's trying to change or use the key when we mark it

	 * - we tell lockdep that we might nest because we might be revoking an

	 *   authorisation key whilst holding the sem on a key we've just

	 *   instantiated
I could, but that potentially wastes time in two ways: firstly, there can be an

error before we've finished setting up, and that can lead to us having wasted

the time spent making the copy; and secondly, the call to kstrdup itself wastes

a bit of time because of the extra call made.
On the other hand, the code might end up a bit shorter, and isn't particularly
Kevin Coffman and Trond for the NFS stuff, both of whom are CC'd.
David

-

Tell me about it - I fixed that about 10000000000 times.  Then we upped the

minimum required gcc version so it is no longer a problem.

-