kernel_optimize_test/include/linux/sunrpc/svcauth.h
Greg Banks 7b2b1fee30 [PATCH] knfsd: knfsd: cache ipmap per TCP socket
Speed up high call-rate workloads by caching the struct ip_map for the peer on
the connected struct svc_sock instead of looking it up in the ip_map cache
hashtable on every call.  This helps workloads using AUTH_SYS authentication
over TCP.

Testing was on a 4 CPU 4 NIC Altix using 4 IRIX clients, each with 16
synthetic client threads simulating an rsync (i.e.  recursive directory
listing) workload reading from an i386 RH9 install image (161480 regular files
in 10841 directories) on the server.  That tree is small enough to fill in the
server's RAM so no disk traffic was involved.  This setup gives a sustained
call rate in excess of 60000 calls/sec before being CPU-bound on the server.

Profiling showed strcmp(), called from ip_map_match(), was taking 4.8% of each
CPU, and ip_map_lookup() was taking 2.9%.  This patch drops both contribution
into the profile noise.

Note that the above result overstates this value of this patch for most
workloads.  The synthetic clients are all using separate IP addresses, so
there are 64 entries in the ip_map cache hash.  Because the kernel measured
contained the bug fixed in commit

commit 1f1e030bf7

and was running on 64bit little-endian machine, probably all of those 64
entries were on a single chain, thus increasing the cost of ip_map_lookup().

With a modern kernel you would need more clients to see the same amount of
performance improvement.  This patch has helped to scale knfsd to handle a
deployment with 2000 NFS clients.

Signed-off-by: Greg Banks <gnb@melbourne.sgi.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-04 07:55:16 -07:00

171 lines
5.3 KiB
C

/*
* linux/include/linux/sunrpc/svcauth.h
*
* RPC server-side authentication stuff.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*/
#ifndef _LINUX_SUNRPC_SVCAUTH_H_
#define _LINUX_SUNRPC_SVCAUTH_H_
#ifdef __KERNEL__
#include <linux/string.h>
#include <linux/sunrpc/msg_prot.h>
#include <linux/sunrpc/cache.h>
#include <linux/hash.h>
#define SVC_CRED_NGROUPS 32
struct svc_cred {
uid_t cr_uid;
gid_t cr_gid;
struct group_info *cr_group_info;
};
struct svc_rqst; /* forward decl */
/* Authentication is done in the context of a domain.
*
* Currently, the nfs server uses the auth_domain to stand
* for the "client" listed in /etc/exports.
*
* More generally, a domain might represent a group of clients using
* a common mechanism for authentication and having a common mapping
* between local identity (uid) and network identity. All clients
* in a domain have similar general access rights. Each domain can
* contain multiple principals which will have different specific right
* based on normal Discretionary Access Control.
*
* A domain is created by an authentication flavour module based on name
* only. Userspace then fills in detail on demand.
*
* In the case of auth_unix and auth_null, the auth_domain is also
* associated with entries in another cache representing the mapping
* of ip addresses to the given client.
*/
struct auth_domain {
struct kref ref;
struct hlist_node hash;
char *name;
struct auth_ops *flavour;
};
/*
* Each authentication flavour registers an auth_ops
* structure.
* name is simply the name.
* flavour gives the auth flavour. It determines where the flavour is registered
* accept() is given a request and should verify it.
* It should inspect the authenticator and verifier, and possibly the data.
* If there is a problem with the authentication *authp should be set.
* The return value of accept() can indicate:
* OK - authorised. client and credential are set in rqstp.
* reqbuf points to arguments
* resbuf points to good place for results. verfier
* is (probably) already in place. Certainly space is
* reserved for it.
* DROP - simply drop the request. It may have been deferred
* GARBAGE - rpc garbage_args error
* SYSERR - rpc system_err error
* DENIED - authp holds reason for denial.
* COMPLETE - the reply is encoded already and ready to be sent; no
* further processing is necessary. (This is used for processing
* null procedure calls which are used to set up encryption
* contexts.)
*
* accept is passed the proc number so that it can accept NULL rpc requests
* even if it cannot authenticate the client (as is sometimes appropriate).
*
* release() is given a request after the procedure has been run.
* It should sign/encrypt the results if needed
* It should return:
* OK - the resbuf is ready to be sent
* DROP - the reply should be quitely dropped
* DENIED - authp holds a reason for MSG_DENIED
* SYSERR - rpc system_err
*
* domain_release()
* This call releases a domain.
* set_client()
* Givens a pending request (struct svc_rqst), finds and assigns
* an appropriate 'auth_domain' as the client.
*/
struct auth_ops {
char * name;
struct module *owner;
int flavour;
int (*accept)(struct svc_rqst *rq, __be32 *authp);
int (*release)(struct svc_rqst *rq);
void (*domain_release)(struct auth_domain *);
int (*set_client)(struct svc_rqst *rq);
};
#define SVC_GARBAGE 1
#define SVC_SYSERR 2
#define SVC_VALID 3
#define SVC_NEGATIVE 4
#define SVC_OK 5
#define SVC_DROP 6
#define SVC_DENIED 7
#define SVC_PENDING 8
#define SVC_COMPLETE 9
extern int svc_authenticate(struct svc_rqst *rqstp, __be32 *authp);
extern int svc_authorise(struct svc_rqst *rqstp);
extern int svc_set_client(struct svc_rqst *rqstp);
extern int svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops);
extern void svc_auth_unregister(rpc_authflavor_t flavor);
extern struct auth_domain *unix_domain_find(char *name);
extern void auth_domain_put(struct auth_domain *item);
extern int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom);
extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *new);
extern struct auth_domain *auth_domain_find(char *name);
extern struct auth_domain *auth_unix_lookup(struct in_addr addr);
extern int auth_unix_forget_old(struct auth_domain *dom);
extern void svcauth_unix_purge(void);
extern void svcauth_unix_info_release(void *);
static inline unsigned long hash_str(char *name, int bits)
{
unsigned long hash = 0;
unsigned long l = 0;
int len = 0;
unsigned char c;
do {
if (unlikely(!(c = *name++))) {
c = (char)len; len = -1;
}
l = (l << 8) | c;
len++;
if ((len & (BITS_PER_LONG/8-1))==0)
hash = hash_long(hash^l, BITS_PER_LONG);
} while (len);
return hash >> (BITS_PER_LONG - bits);
}
static inline unsigned long hash_mem(char *buf, int length, int bits)
{
unsigned long hash = 0;
unsigned long l = 0;
int len = 0;
unsigned char c;
do {
if (len == length) {
c = (char)len; len = -1;
} else
c = *buf++;
l = (l << 8) | c;
len++;
if ((len & (BITS_PER_LONG/8-1))==0)
hash = hash_long(hash^l, BITS_PER_LONG);
} while (len);
return hash >> (BITS_PER_LONG - bits);
}
#endif /* __KERNEL__ */
#endif /* _LINUX_SUNRPC_SVCAUTH_H_ */