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authorLinus Torvalds <torvalds@linux-foundation.org>2018-10-30 13:03:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-30 13:03:29 -0700
commit310c7585e8300ddc46211df0757c11e4299ec482 (patch)
treed272d2160c68bb02589597c4bafc35b667811a8c /net/sunrpc/svcauth.c
parent9b190ecca11c6ed6e20f35caef5746416d8ee0f0 (diff)
parent93f38b6fae0ea8987e22d9e6c38f8dfdccd867ee (diff)
downloadlinux-310c7585e8300ddc46211df0757c11e4299ec482.tar.bz2
Merge tag 'nfsd-4.20' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields: "Olga added support for the NFSv4.2 asynchronous copy protocol. We already supported COPY, by copying a limited amount of data and then returning a short result, letting the client resend. The asynchronous protocol should offer better performance at the expense of some complexity. The other highlight is Trond's work to convert the duplicate reply cache to a red-black tree, and to move it and some other server caches to RCU. (Previously these have meant taking global spinlocks on every RPC) Otherwise, some RDMA work and miscellaneous bugfixes" * tag 'nfsd-4.20' of git://linux-nfs.org/~bfields/linux: (30 commits) lockd: fix access beyond unterminated strings in prints nfsd: Fix an Oops in free_session() nfsd: correctly decrement odstate refcount in error path svcrdma: Increase the default connection credit limit svcrdma: Remove try_module_get from backchannel svcrdma: Remove ->release_rqst call in bc reply handler svcrdma: Reduce max_send_sges nfsd: fix fall-through annotations knfsd: Improve lookup performance in the duplicate reply cache using an rbtree knfsd: Further simplify the cache lookup knfsd: Simplify NFS duplicate replay cache knfsd: Remove dead code from nfsd_cache_lookup SUNRPC: Simplify TCP receive code SUNRPC: Replace the cache_detail->hash_lock with a regular spinlock SUNRPC: Remove non-RCU protected lookup NFS: Fix up a typo in nfs_dns_ent_put NFS: Lockless DNS lookups knfsd: Lockless lookup of NFSv4 identities. SUNRPC: Lockless server RPCSEC_GSS context lookup knfsd: Allow lockless lookups of the exports ...
Diffstat (limited to 'net/sunrpc/svcauth.c')
-rw-r--r--net/sunrpc/svcauth.c74
1 files changed, 53 insertions, 21 deletions
diff --git a/net/sunrpc/svcauth.c b/net/sunrpc/svcauth.c
index bb8db3cb8032..775b8c94265b 100644
--- a/net/sunrpc/svcauth.c
+++ b/net/sunrpc/svcauth.c
@@ -27,12 +27,32 @@
extern struct auth_ops svcauth_null;
extern struct auth_ops svcauth_unix;
-static DEFINE_SPINLOCK(authtab_lock);
-static struct auth_ops *authtab[RPC_AUTH_MAXFLAVOR] = {
- [0] = &svcauth_null,
- [1] = &svcauth_unix,
+static struct auth_ops __rcu *authtab[RPC_AUTH_MAXFLAVOR] = {
+ [RPC_AUTH_NULL] = (struct auth_ops __force __rcu *)&svcauth_null,
+ [RPC_AUTH_UNIX] = (struct auth_ops __force __rcu *)&svcauth_unix,
};
+static struct auth_ops *
+svc_get_auth_ops(rpc_authflavor_t flavor)
+{
+ struct auth_ops *aops;
+
+ if (flavor >= RPC_AUTH_MAXFLAVOR)
+ return NULL;
+ rcu_read_lock();
+ aops = rcu_dereference(authtab[flavor]);
+ if (aops != NULL && !try_module_get(aops->owner))
+ aops = NULL;
+ rcu_read_unlock();
+ return aops;
+}
+
+static void
+svc_put_auth_ops(struct auth_ops *aops)
+{
+ module_put(aops->owner);
+}
+
int
svc_authenticate(struct svc_rqst *rqstp, __be32 *authp)
{
@@ -45,14 +65,11 @@ svc_authenticate(struct svc_rqst *rqstp, __be32 *authp)
dprintk("svc: svc_authenticate (%d)\n", flavor);
- spin_lock(&authtab_lock);
- if (flavor >= RPC_AUTH_MAXFLAVOR || !(aops = authtab[flavor]) ||
- !try_module_get(aops->owner)) {
- spin_unlock(&authtab_lock);
+ aops = svc_get_auth_ops(flavor);
+ if (aops == NULL) {
*authp = rpc_autherr_badcred;
return SVC_DENIED;
}
- spin_unlock(&authtab_lock);
rqstp->rq_auth_slack = 0;
init_svc_cred(&rqstp->rq_cred);
@@ -82,7 +99,7 @@ int svc_authorise(struct svc_rqst *rqstp)
if (aops) {
rv = aops->release(rqstp);
- module_put(aops->owner);
+ svc_put_auth_ops(aops);
}
return rv;
}
@@ -90,13 +107,14 @@ int svc_authorise(struct svc_rqst *rqstp)
int
svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops)
{
+ struct auth_ops *old;
int rv = -EINVAL;
- spin_lock(&authtab_lock);
- if (flavor < RPC_AUTH_MAXFLAVOR && authtab[flavor] == NULL) {
- authtab[flavor] = aops;
- rv = 0;
+
+ if (flavor < RPC_AUTH_MAXFLAVOR) {
+ old = cmpxchg((struct auth_ops ** __force)&authtab[flavor], NULL, aops);
+ if (old == NULL || old == aops)
+ rv = 0;
}
- spin_unlock(&authtab_lock);
return rv;
}
EXPORT_SYMBOL_GPL(svc_auth_register);
@@ -104,10 +122,8 @@ EXPORT_SYMBOL_GPL(svc_auth_register);
void
svc_auth_unregister(rpc_authflavor_t flavor)
{
- spin_lock(&authtab_lock);
if (flavor < RPC_AUTH_MAXFLAVOR)
- authtab[flavor] = NULL;
- spin_unlock(&authtab_lock);
+ rcu_assign_pointer(authtab[flavor], NULL);
}
EXPORT_SYMBOL_GPL(svc_auth_unregister);
@@ -127,10 +143,11 @@ static struct hlist_head auth_domain_table[DN_HASHMAX];
static DEFINE_SPINLOCK(auth_domain_lock);
static void auth_domain_release(struct kref *kref)
+ __releases(&auth_domain_lock)
{
struct auth_domain *dom = container_of(kref, struct auth_domain, ref);
- hlist_del(&dom->hash);
+ hlist_del_rcu(&dom->hash);
dom->flavour->domain_release(dom);
spin_unlock(&auth_domain_lock);
}
@@ -159,7 +176,7 @@ auth_domain_lookup(char *name, struct auth_domain *new)
}
}
if (new)
- hlist_add_head(&new->hash, head);
+ hlist_add_head_rcu(&new->hash, head);
spin_unlock(&auth_domain_lock);
return new;
}
@@ -167,6 +184,21 @@ EXPORT_SYMBOL_GPL(auth_domain_lookup);
struct auth_domain *auth_domain_find(char *name)
{
- return auth_domain_lookup(name, NULL);
+ struct auth_domain *hp;
+ struct hlist_head *head;
+
+ head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(hp, head, hash) {
+ if (strcmp(hp->name, name)==0) {
+ if (!kref_get_unless_zero(&hp->ref))
+ hp = NULL;
+ rcu_read_unlock();
+ return hp;
+ }
+ }
+ rcu_read_unlock();
+ return NULL;
}
EXPORT_SYMBOL_GPL(auth_domain_find);