[PATCH] knfsd: lockd: introduce nsm_handle
This patch introduces the nsm_handle, which is shared by all nlm_host objects
referring to the same client.
With this patch applied, all nlm_hosts from the same address will share the
same nsm_handle. A future patch will add sharing by name.
Note: this patch changes h_name so that it is no longer guaranteed to be an IP
address of the host. When the host represents an NFS server, h_name will be
the name passed in the mount call. When the host represents a client, h_name
will be the name presented in the lock request received from the client. A
h_name is only used for printing informational messages, this change should
not be significant.
Signed-off-by: Olaf Kirch <okir@suse.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index 481ce7e..0bf4afb 100644
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -34,6 +34,8 @@
static void nlm_gc_hosts(void);
+static struct nsm_handle * __nsm_find(const struct sockaddr_in *,
+ const char *, int, int);
/*
* Find an NLM server handle in the cache. If there is none, create it.
@@ -68,7 +70,7 @@
int hostname_len)
{
struct nlm_host *host, **hp;
- u32 addr;
+ struct nsm_handle *nsm = NULL;
int hash;
dprintk("lockd: nlm_lookup_host(%u.%u.%u.%u, p=%d, v=%d, my role=%s, name=%.*s)\n",
@@ -86,7 +88,21 @@
if (time_after_eq(jiffies, next_gc))
nlm_gc_hosts();
+ /* We may keep several nlm_host objects for a peer, because each
+ * nlm_host is identified by
+ * (address, protocol, version, server/client)
+ * We could probably simplify this a little by putting all those
+ * different NLM rpc_clients into one single nlm_host object.
+ * This would allow us to have one nlm_host per address.
+ */
for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
+ if (!nlm_cmp_addr(&host->h_addr, sin))
+ continue;
+
+ /* See if we have an NSM handle for this client */
+ if (!nsm && (nsm = host->h_nsmhandle) != 0)
+ atomic_inc(&nsm->sm_count);
+
if (host->h_proto != proto)
continue;
if (host->h_version != version)
@@ -94,7 +110,7 @@
if (host->h_server != server)
continue;
- if (nlm_cmp_addr(&host->h_addr, sin)) {
+ {
if (hp != nlm_hosts + hash) {
*hp = host->h_next;
host->h_next = nlm_hosts[hash];
@@ -106,16 +122,18 @@
}
}
- /* Ooops, no host found, create it */
- dprintk("lockd: creating host entry\n");
+ /* Sadly, the host isn't in our hash table yet. See if
+ * we have an NSM handle for it. If not, create one.
+ */
+ if (!nsm && !(nsm = nsm_find(sin, hostname, hostname_len)))
+ goto out;
host = kzalloc(sizeof(*host), GFP_KERNEL);
- if (!host)
- goto nohost;
-
- addr = sin->sin_addr.s_addr;
- sprintf(host->h_name, "%u.%u.%u.%u", NIPQUAD(addr));
-
+ if (!host) {
+ nsm_release(nsm);
+ goto out;
+ }
+ host->h_name = nsm->sm_name;
host->h_addr = *sin;
host->h_addr.sin_port = 0; /* ouch! */
host->h_version = version;
@@ -129,6 +147,7 @@
init_rwsem(&host->h_rwsem);
host->h_state = 0; /* pseudo NSM state */
host->h_nsmstate = 0; /* real NSM state */
+ host->h_nsmhandle = nsm;
host->h_server = server;
host->h_next = nlm_hosts[hash];
nlm_hosts[hash] = host;
@@ -140,7 +159,7 @@
if (++nrhosts > NLM_HOST_MAX)
next_gc = 0;
-nohost:
+out:
mutex_unlock(&nlm_host_mutex);
return host;
}
@@ -393,3 +412,83 @@
next_gc = jiffies + NLM_HOST_COLLECT;
}
+
+/*
+ * Manage NSM handles
+ */
+static LIST_HEAD(nsm_handles);
+static DECLARE_MUTEX(nsm_sema);
+
+static struct nsm_handle *
+__nsm_find(const struct sockaddr_in *sin,
+ const char *hostname, int hostname_len,
+ int create)
+{
+ struct nsm_handle *nsm = NULL;
+ struct list_head *pos;
+
+ if (!sin)
+ return NULL;
+
+ if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
+ if (printk_ratelimit()) {
+ printk(KERN_WARNING "Invalid hostname \"%.*s\" "
+ "in NFS lock request\n",
+ hostname_len, hostname);
+ }
+ return NULL;
+ }
+
+ down(&nsm_sema);
+ list_for_each(pos, &nsm_handles) {
+ nsm = list_entry(pos, struct nsm_handle, sm_link);
+
+ if (!nlm_cmp_addr(&nsm->sm_addr, sin))
+ continue;
+ atomic_inc(&nsm->sm_count);
+ goto out;
+ }
+
+ if (!create) {
+ nsm = NULL;
+ goto out;
+ }
+
+ nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
+ if (nsm != NULL) {
+ nsm->sm_addr = *sin;
+ nsm->sm_name = (char *) (nsm + 1);
+ memcpy(nsm->sm_name, hostname, hostname_len);
+ nsm->sm_name[hostname_len] = '\0';
+ atomic_set(&nsm->sm_count, 1);
+
+ list_add(&nsm->sm_link, &nsm_handles);
+ }
+
+out: up(&nsm_sema);
+ return nsm;
+}
+
+struct nsm_handle *
+nsm_find(const struct sockaddr_in *sin, const char *hostname, int hostname_len)
+{
+ return __nsm_find(sin, hostname, hostname_len, 1);
+}
+
+/*
+ * Release an NSM handle
+ */
+void
+nsm_release(struct nsm_handle *nsm)
+{
+ if (!nsm)
+ return;
+ if (atomic_dec_and_test(&nsm->sm_count)) {
+ down(&nsm_sema);
+ if (atomic_read(&nsm->sm_count) == 0) {
+ list_del(&nsm->sm_link);
+ kfree(nsm);
+ }
+ up(&nsm_sema);
+ }
+}