diff options
Diffstat (limited to 'fs/lockd/mon.c')
| -rw-r--r-- | fs/lockd/mon.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c index 81e1cc14246..8e68e799293 100644 --- a/fs/lockd/mon.c +++ b/fs/lockd/mon.c @@ -47,12 +47,51 @@ struct nsm_res { static struct rpc_clnt * nsm_create(void); static struct rpc_program nsm_program; +static LIST_HEAD(nsm_handles); +static DEFINE_SPINLOCK(nsm_lock); /* * Local NSM state */ int nsm_local_state; +static void nsm_display_ipv4_address(const struct sockaddr *sap, char *buf, + const size_t len) +{ + const struct sockaddr_in *sin = (struct sockaddr_in *)sap; + snprintf(buf, len, "%pI4", &sin->sin_addr.s_addr); +} + +static void nsm_display_ipv6_address(const struct sockaddr *sap, char *buf, + const size_t len) +{ + const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap; + + if (ipv6_addr_v4mapped(&sin6->sin6_addr)) + snprintf(buf, len, "%pI4", &sin6->sin6_addr.s6_addr32[3]); + else if (sin6->sin6_scope_id != 0) + snprintf(buf, len, "%pI6%%%u", &sin6->sin6_addr, + sin6->sin6_scope_id); + else + snprintf(buf, len, "%pI6", &sin6->sin6_addr); +} + +static void nsm_display_address(const struct sockaddr *sap, + char *buf, const size_t len) +{ + switch (sap->sa_family) { + case AF_INET: + nsm_display_ipv4_address(sap, buf, len); + break; + case AF_INET6: + nsm_display_ipv6_address(sap, buf, len); + break; + default: + snprintf(buf, len, "unsupported address family"); + break; + } +} + /* * Common procedure for NSMPROC_MON/NSMPROC_UNMON calls */ @@ -162,6 +201,100 @@ void nsm_unmonitor(const struct nlm_host *host) } } +/** + * nsm_find - Find or create a cached nsm_handle + * @sap: pointer to socket address of handle to find + * @salen: length of socket address + * @hostname: pointer to C string containing hostname to find + * @hostname_len: length of C string + * @create: one means create new handle if not found in cache + * + * Behavior is modulated by the global nsm_use_hostnames variable + * and by the @create argument. + * + * Returns a cached nsm_handle after bumping its ref count, or if + * @create is set, returns a fresh nsm_handle if a handle that + * matches @sap and/or @hostname cannot be found in the handle cache. + * Returns NULL if an error occurs. + */ +struct nsm_handle *nsm_find(const struct sockaddr *sap, const size_t salen, + const char *hostname, const size_t hostname_len, + const int create) +{ + struct nsm_handle *nsm = NULL; + struct nsm_handle *pos; + + if (!sap) + return NULL; + + if (hostname && memchr(hostname, '/', hostname_len) != NULL) { + if (printk_ratelimit()) { + printk(KERN_WARNING "Invalid hostname \"%.*s\" " + "in NFS lock request\n", + (int)hostname_len, hostname); + } + return NULL; + } + +retry: + spin_lock(&nsm_lock); + list_for_each_entry(pos, &nsm_handles, sm_link) { + + if (hostname && nsm_use_hostnames) { + if (strlen(pos->sm_name) != hostname_len + || memcmp(pos->sm_name, hostname, hostname_len)) + continue; + } else if (!nlm_cmp_addr(nsm_addr(pos), sap)) + continue; + atomic_inc(&pos->sm_count); + kfree(nsm); + nsm = pos; + goto found; + } + if (nsm) { + list_add(&nsm->sm_link, &nsm_handles); + goto found; + } + spin_unlock(&nsm_lock); + + if (!create) + return NULL; + + nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL); + if (nsm == NULL) + return NULL; + + memcpy(nsm_addr(nsm), sap, salen); + nsm->sm_addrlen = salen; + nsm->sm_name = (char *) (nsm + 1); + memcpy(nsm->sm_name, hostname, hostname_len); + nsm->sm_name[hostname_len] = '\0'; + nsm_display_address((struct sockaddr *)&nsm->sm_addr, + nsm->sm_addrbuf, sizeof(nsm->sm_addrbuf)); + atomic_set(&nsm->sm_count, 1); + goto retry; + +found: + spin_unlock(&nsm_lock); + return nsm; +} + +/** + * nsm_release - Release an NSM handle + * @nsm: pointer to handle to be released + * + */ +void nsm_release(struct nsm_handle *nsm) +{ + if (!nsm) + return; + if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) { + list_del(&nsm->sm_link); + spin_unlock(&nsm_lock); + kfree(nsm); + } +} + /* * Create NSM client for the local host */ |