[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>

2 files changed, 40 insertions, 33 deletions

diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index 3cd96e2e1256..4449ef0b7837 100644
--- 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 a41eb841428b..c8635d84d5d2 100644
--- 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 */