From 8dead0dbd478f35fd943f3719591e5af1ac0950d Mon Sep 17 00:00:00 2001 From: Olaf Kirch Date: Wed, 4 Oct 2006 02:15:53 -0700 Subject: [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 Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/lockd/host.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 110 insertions(+), 11 deletions(-) (limited to 'fs/lockd/host.c') diff --git a/fs/lockd/host.c b/fs/lockd/host.c index 481ce7ee100..0bf4afb71d2 100644 --- a/fs/lockd/host.c +++ b/fs/lockd/host.c @@ -34,6 +34,8 @@ static DEFINE_MUTEX(nlm_host_mutex); 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 @@ nlm_lookup_host(int server, const struct sockaddr_in *sin, 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 @@ nlm_lookup_host(int server, const struct sockaddr_in *sin, 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 @@ nlm_lookup_host(int server, const struct sockaddr_in *sin, 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 @@ nlm_lookup_host(int server, const struct sockaddr_in *sin, } } - /* 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 @@ nlm_lookup_host(int server, const struct sockaddr_in *sin, 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 @@ nlm_lookup_host(int server, const struct sockaddr_in *sin, if (++nrhosts > NLM_HOST_MAX) next_gc = 0; -nohost: +out: mutex_unlock(&nlm_host_mutex); return host; } @@ -393,3 +412,83 @@ nlm_gc_hosts(void) 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); + } +} -- cgit v1.2.3