From 608a0ab2f54ab0e301ad76a41aad979ea0d02670 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 1 Oct 2018 10:41:44 -0400 Subject: SUNRPC: Add lockless lookup of the server's auth domain Avoid taking the global auth_domain_lock in most lookups of the auth domain by adding an RCU protected lookup. Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields --- net/sunrpc/auth_gss/svcauth_gss.c | 9 ++++++++- net/sunrpc/svcauth.c | 22 +++++++++++++++++++--- net/sunrpc/svcauth_unix.c | 10 ++++++++-- 3 files changed, 35 insertions(+), 6 deletions(-) (limited to 'net/sunrpc') diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c index 860f2a1bbb67..87c71fb0f0ea 100644 --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -1764,14 +1764,21 @@ out_err: } static void -svcauth_gss_domain_release(struct auth_domain *dom) +svcauth_gss_domain_release_rcu(struct rcu_head *head) { + struct auth_domain *dom = container_of(head, struct auth_domain, rcu_head); struct gss_domain *gd = container_of(dom, struct gss_domain, h); kfree(dom->name); kfree(gd); } +static void +svcauth_gss_domain_release(struct auth_domain *dom) +{ + call_rcu(&dom->rcu_head, svcauth_gss_domain_release_rcu); +} + static struct auth_ops svcauthops_gss = { .name = "rpcsec_gss", .owner = THIS_MODULE, diff --git a/net/sunrpc/svcauth.c b/net/sunrpc/svcauth.c index f83443856cd1..775b8c94265b 100644 --- a/net/sunrpc/svcauth.c +++ b/net/sunrpc/svcauth.c @@ -143,10 +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); } @@ -175,7 +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; } @@ -183,6 +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); diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c index af7f28fb8102..84cf39021a03 100644 --- a/net/sunrpc/svcauth_unix.c +++ b/net/sunrpc/svcauth_unix.c @@ -37,20 +37,26 @@ struct unix_domain { extern struct auth_ops svcauth_null; extern struct auth_ops svcauth_unix; -static void svcauth_unix_domain_release(struct auth_domain *dom) +static void svcauth_unix_domain_release_rcu(struct rcu_head *head) { + struct auth_domain *dom = container_of(head, struct auth_domain, rcu_head); struct unix_domain *ud = container_of(dom, struct unix_domain, h); kfree(dom->name); kfree(ud); } +static void svcauth_unix_domain_release(struct auth_domain *dom) +{ + call_rcu(&dom->rcu_head, svcauth_unix_domain_release_rcu); +} + struct auth_domain *unix_domain_find(char *name) { struct auth_domain *rv; struct unix_domain *new = NULL; - rv = auth_domain_lookup(name, NULL); + rv = auth_domain_find(name); while(1) { if (rv) { if (new && rv != &new->h) -- cgit v1.2.1