[PATCH] knfsd: lockd: make the hash chains use a hlist_node

Get rid of the home-grown singly linked lists for the nlm_host hash table.

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 3cd96e2..4449ef0 100644 (file)
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -27,7 +27,7 @@
 #define NLM_HOST_EXPIRE                ((nrhosts > NLM_HOST_MAX)? 300 * HZ : 120 * HZ)
 #define NLM_HOST_COLLECT       ((nrhosts > NLM_HOST_MAX)? 120 * HZ :  60 * HZ)
 
-static struct nlm_host *       nlm_hosts[NLM_HOST_NRHASH];
+static struct hlist_head       nlm_hosts[NLM_HOST_NRHASH];
 static unsigned long           next_gc;
 static int                     nrhosts;
 static DEFINE_MUTEX(nlm_host_mutex);
@@ -69,7 +69,9 @@ nlm_lookup_host(int server, const struct sockaddr_in *sin,
                                        const char *hostname,
                                        int hostname_len)
 {
-       struct nlm_host *host, **hp;
+       struct hlist_head *chain;
+       struct hlist_node *pos;
+       struct nlm_host *host;
        struct nsm_handle *nsm = NULL;
        int             hash;
 
@@ -95,7 +97,8 @@ nlm_lookup_host(int server, const struct sockaddr_in *sin,
         * 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) {
+       chain = &nlm_hosts[hash];
+       hlist_for_each_entry(host, pos, chain, h_hash) {
                if (!nlm_cmp_addr(&host->h_addr, sin))
                        continue;
 
@@ -110,15 +113,16 @@ nlm_lookup_host(int server, const struct sockaddr_in *sin,
                if (host->h_server != server)
                        continue;
 
-               if (hp != nlm_hosts + hash) {
-                       *hp = host->h_next;
-                       host->h_next = nlm_hosts[hash];
-                       nlm_hosts[hash] = host;
-               }
+               /* Move to head of hash chain. */
+               hlist_del(&host->h_hash);
+               hlist_add_head(&host->h_hash, chain);
+
                nlm_get_host(host);
                goto out;
        }
 
+       host = NULL;
+
        /* Sadly, the host isn't in our hash table yet. See if
         * we have an NSM handle for it. If not, create one.
         */
@@ -146,8 +150,7 @@ nlm_lookup_host(int server, const struct sockaddr_in *sin,
        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;
+       hlist_add_head(&host->h_hash, chain);
        INIT_LIST_HEAD(&host->h_lockowners);
        spin_lock_init(&host->h_lock);
        INIT_LIST_HEAD(&host->h_granted);
@@ -164,14 +167,17 @@ out:
 struct nlm_host *
 nlm_find_client(void)
 {
+       struct hlist_head *chain;
+       struct hlist_node *pos;
+
        /* find a nlm_host for a client for which h_killed == 0.
         * and return it
         */
-       int hash;
        mutex_lock(&nlm_host_mutex);
-       for (hash = 0 ; hash < NLM_HOST_NRHASH; hash++) {
-               struct nlm_host *host, **hp;
-               for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
+       for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+               struct nlm_host *host;
+
+               hlist_for_each_entry(host, pos, chain, h_hash) {
                        if (host->h_server &&
                            host->h_killed == 0) {
                                nlm_get_host(host);
@@ -294,9 +300,10 @@ void nlm_host_rebooted(const struct sockaddr_in *sin,
                                const char *hostname, int hostname_len,
                                u32 new_state)
 {
+       struct hlist_head *chain;
+       struct hlist_node *pos;
        struct nsm_handle *nsm;
-       struct nlm_host *host, **hp;
-       int             hash;
+       struct nlm_host *host;
 
        dprintk("lockd: nlm_host_rebooted(%s, %u.%u.%u.%u)\n",
                        hostname, NIPQUAD(sin->sin_addr));
@@ -315,8 +322,8 @@ void nlm_host_rebooted(const struct sockaddr_in *sin,
         * To avoid processing a host several times, we match the nsmstate.
         */
 again: mutex_lock(&nlm_host_mutex);
-       for (hash = 0; hash < NLM_HOST_NRHASH; hash++) {
-               for (hp = &nlm_hosts[hash]; (host = *hp); hp = &host->h_next) {
+       for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+               hlist_for_each_entry(host, pos, chain, h_hash) {
                        if (host->h_nsmhandle == nsm
                         && host->h_nsmstate != new_state) {
                                host->h_nsmstate = new_state;
@@ -350,16 +357,17 @@ again:    mutex_lock(&nlm_host_mutex);
 void
 nlm_shutdown_hosts(void)
 {
+       struct hlist_head *chain;
+       struct hlist_node *pos;
        struct nlm_host *host;
-       int             i;
 
        dprintk("lockd: shutting down host module\n");
        mutex_lock(&nlm_host_mutex);
 
        /* First, make all hosts eligible for gc */
        dprintk("lockd: nuking all hosts...\n");
-       for (i = 0; i < NLM_HOST_NRHASH; i++) {
-               for (host = nlm_hosts[i]; host; host = host->h_next)
+       for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+               hlist_for_each_entry(host, pos, chain, h_hash)
                        host->h_expires = jiffies - 1;
        }
 
@@ -371,8 +379,8 @@ nlm_shutdown_hosts(void)
        if (nrhosts) {
                printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
                dprintk("lockd: %d hosts left:\n", nrhosts);
-               for (i = 0; i < NLM_HOST_NRHASH; i++) {
-                       for (host = nlm_hosts[i]; host; host = host->h_next) {
+               for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+                       hlist_for_each_entry(host, pos, chain, h_hash) {
                                dprintk("       %s (cnt %d use %d exp %ld)\n",
                                        host->h_name, atomic_read(&host->h_count),
                                        host->h_inuse, host->h_expires);
@@ -389,32 +397,31 @@ nlm_shutdown_hosts(void)
 static void
 nlm_gc_hosts(void)
 {
-       struct nlm_host **q, *host;
+       struct hlist_head *chain;
+       struct hlist_node *pos, *next;
+       struct nlm_host *host;
        struct rpc_clnt *clnt;
-       int             i;
 
        dprintk("lockd: host garbage collection\n");
-       for (i = 0; i < NLM_HOST_NRHASH; i++) {
-               for (host = nlm_hosts[i]; host; host = host->h_next)
+       for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+               hlist_for_each_entry(host, pos, chain, h_hash)
                        host->h_inuse = 0;
        }
 
        /* Mark all hosts that hold locks, blocks or shares */
        nlmsvc_mark_resources();
 
-       for (i = 0; i < NLM_HOST_NRHASH; i++) {
-               q = &nlm_hosts[i];
-               while ((host = *q) != NULL) {
+       for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+               hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
                        if (atomic_read(&host->h_count) || host->h_inuse
                         || time_before(jiffies, host->h_expires)) {
                                dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
                                        host->h_name, atomic_read(&host->h_count),
                                        host->h_inuse, host->h_expires);
-                               q = &host->h_next;
                                continue;
                        }
                        dprintk("lockd: delete host %s\n", host->h_name);
-                       *q = host->h_next;
+                       hlist_del_init(&host->h_hash);
 
                        /*
                         * Unmonitor unless host was invalidated (i.e. lockd restarted)

diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index a41eb84..c8635d8 100644 (file)
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -37,7 +37,7 @@
  * Lockd host handle (used both by the client and server personality).
  */
 struct nlm_host {
-       struct nlm_host *       h_next;         /* linked list (hash table) */
+       struct hlist_node       h_hash;         /* doubly linked list */
        struct sockaddr_in      h_addr;         /* peer address */
        struct rpc_clnt *       h_rpcclnt;      /* RPC client to talk to peer */
        char *                  h_name;         /* remote hostname */