From 0cea32761a2f954c6d42ca79d7d1e6b9663b1e4a Mon Sep 17 00:00:00 2001 From: Olaf Kirch Date: Wed, 4 Oct 2006 02:15:56 -0700 Subject: [PATCH] [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 Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/lockd/host.c | 71 ++++++++++++++++++++----------------- include/linux/lockd/lockd.h | 2 +- 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 */ -- 2.20.1