| /* |
| * linux/net/sunrpc/svc_xprt.c |
| * |
| * Author: Tom Tucker <tom@opengridcomputing.com> |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/errno.h> |
| #include <linux/freezer.h> |
| #include <linux/kthread.h> |
| #include <linux/slab.h> |
| #include <net/sock.h> |
| #include <linux/sunrpc/stats.h> |
| #include <linux/sunrpc/svc_xprt.h> |
| #include <linux/sunrpc/svcsock.h> |
| #include <linux/sunrpc/xprt.h> |
| |
| #define RPCDBG_FACILITY RPCDBG_SVCXPRT |
| |
| static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt); |
| static int svc_deferred_recv(struct svc_rqst *rqstp); |
| static struct cache_deferred_req *svc_defer(struct cache_req *req); |
| static void svc_age_temp_xprts(unsigned long closure); |
| |
| /* apparently the "standard" is that clients close |
| * idle connections after 5 minutes, servers after |
| * 6 minutes |
| * http://www.connectathon.org/talks96/nfstcp.pdf |
| */ |
| static int svc_conn_age_period = 6*60; |
| |
| /* List of registered transport classes */ |
| static DEFINE_SPINLOCK(svc_xprt_class_lock); |
| static LIST_HEAD(svc_xprt_class_list); |
| |
| /* SMP locking strategy: |
| * |
| * svc_pool->sp_lock protects most of the fields of that pool. |
| * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt. |
| * when both need to be taken (rare), svc_serv->sv_lock is first. |
| * BKL protects svc_serv->sv_nrthread. |
| * svc_sock->sk_lock protects the svc_sock->sk_deferred list |
| * and the ->sk_info_authunix cache. |
| * |
| * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being |
| * enqueued multiply. During normal transport processing this bit |
| * is set by svc_xprt_enqueue and cleared by svc_xprt_received. |
| * Providers should not manipulate this bit directly. |
| * |
| * Some flags can be set to certain values at any time |
| * providing that certain rules are followed: |
| * |
| * XPT_CONN, XPT_DATA: |
| * - Can be set or cleared at any time. |
| * - After a set, svc_xprt_enqueue must be called to enqueue |
| * the transport for processing. |
| * - After a clear, the transport must be read/accepted. |
| * If this succeeds, it must be set again. |
| * XPT_CLOSE: |
| * - Can set at any time. It is never cleared. |
| * XPT_DEAD: |
| * - Can only be set while XPT_BUSY is held which ensures |
| * that no other thread will be using the transport or will |
| * try to set XPT_DEAD. |
| */ |
| |
| int svc_reg_xprt_class(struct svc_xprt_class *xcl) |
| { |
| struct svc_xprt_class *cl; |
| int res = -EEXIST; |
| |
| dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name); |
| |
| INIT_LIST_HEAD(&xcl->xcl_list); |
| spin_lock(&svc_xprt_class_lock); |
| /* Make sure there isn't already a class with the same name */ |
| list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) { |
| if (strcmp(xcl->xcl_name, cl->xcl_name) == 0) |
| goto out; |
| } |
| list_add_tail(&xcl->xcl_list, &svc_xprt_class_list); |
| res = 0; |
| out: |
| spin_unlock(&svc_xprt_class_lock); |
| return res; |
| } |
| EXPORT_SYMBOL_GPL(svc_reg_xprt_class); |
| |
| void svc_unreg_xprt_class(struct svc_xprt_class *xcl) |
| { |
| dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name); |
| spin_lock(&svc_xprt_class_lock); |
| list_del_init(&xcl->xcl_list); |
| spin_unlock(&svc_xprt_class_lock); |
| } |
| EXPORT_SYMBOL_GPL(svc_unreg_xprt_class); |
| |
| /* |
| * Format the transport list for printing |
| */ |
| int svc_print_xprts(char *buf, int maxlen) |
| { |
| struct svc_xprt_class *xcl; |
| char tmpstr[80]; |
| int len = 0; |
| buf[0] = '\0'; |
| |
| spin_lock(&svc_xprt_class_lock); |
| list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { |
| int slen; |
| |
| sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload); |
| slen = strlen(tmpstr); |
| if (len + slen > maxlen) |
| break; |
| len += slen; |
| strcat(buf, tmpstr); |
| } |
| spin_unlock(&svc_xprt_class_lock); |
| |
| return len; |
| } |
| |
| static void svc_xprt_free(struct kref *kref) |
| { |
| struct svc_xprt *xprt = |
| container_of(kref, struct svc_xprt, xpt_ref); |
| struct module *owner = xprt->xpt_class->xcl_owner; |
| if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) |
| svcauth_unix_info_release(xprt); |
| put_net(xprt->xpt_net); |
| /* See comment on corresponding get in xs_setup_bc_tcp(): */ |
| if (xprt->xpt_bc_xprt) |
| xprt_put(xprt->xpt_bc_xprt); |
| xprt->xpt_ops->xpo_free(xprt); |
| module_put(owner); |
| } |
| |
| void svc_xprt_put(struct svc_xprt *xprt) |
| { |
| kref_put(&xprt->xpt_ref, svc_xprt_free); |
| } |
| EXPORT_SYMBOL_GPL(svc_xprt_put); |
| |
| /* |
| * Called by transport drivers to initialize the transport independent |
| * portion of the transport instance. |
| */ |
| void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt, |
| struct svc_serv *serv) |
| { |
| memset(xprt, 0, sizeof(*xprt)); |
| xprt->xpt_class = xcl; |
| xprt->xpt_ops = xcl->xcl_ops; |
| kref_init(&xprt->xpt_ref); |
| xprt->xpt_server = serv; |
| INIT_LIST_HEAD(&xprt->xpt_list); |
| INIT_LIST_HEAD(&xprt->xpt_ready); |
| INIT_LIST_HEAD(&xprt->xpt_deferred); |
| INIT_LIST_HEAD(&xprt->xpt_users); |
| mutex_init(&xprt->xpt_mutex); |
| spin_lock_init(&xprt->xpt_lock); |
| set_bit(XPT_BUSY, &xprt->xpt_flags); |
| rpc_init_wait_queue(&xprt->xpt_bc_pending, "xpt_bc_pending"); |
| xprt->xpt_net = get_net(&init_net); |
| } |
| EXPORT_SYMBOL_GPL(svc_xprt_init); |
| |
| static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl, |
| struct svc_serv *serv, |
| struct net *net, |
| const int family, |
| const unsigned short port, |
| int flags) |
| { |
| struct sockaddr_in sin = { |
| .sin_family = AF_INET, |
| .sin_addr.s_addr = htonl(INADDR_ANY), |
| .sin_port = htons(port), |
| }; |
| #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) |
| struct sockaddr_in6 sin6 = { |
| .sin6_family = AF_INET6, |
| .sin6_addr = IN6ADDR_ANY_INIT, |
| .sin6_port = htons(port), |
| }; |
| #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */ |
| struct sockaddr *sap; |
| size_t len; |
| |
| switch (family) { |
| case PF_INET: |
| sap = (struct sockaddr *)&sin; |
| len = sizeof(sin); |
| break; |
| #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) |
| case PF_INET6: |
| sap = (struct sockaddr *)&sin6; |
| len = sizeof(sin6); |
| break; |
| #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */ |
| default: |
| return ERR_PTR(-EAFNOSUPPORT); |
| } |
| |
| return xcl->xcl_ops->xpo_create(serv, net, sap, len, flags); |
| } |
| |
| int svc_create_xprt(struct svc_serv *serv, const char *xprt_name, |
| struct net *net, const int family, |
| const unsigned short port, int flags) |
| { |
| struct svc_xprt_class *xcl; |
| |
| dprintk("svc: creating transport %s[%d]\n", xprt_name, port); |
| spin_lock(&svc_xprt_class_lock); |
| list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { |
| struct svc_xprt *newxprt; |
| unsigned short newport; |
| |
| if (strcmp(xprt_name, xcl->xcl_name)) |
| continue; |
| |
| if (!try_module_get(xcl->xcl_owner)) |
| goto err; |
| |
| spin_unlock(&svc_xprt_class_lock); |
| newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags); |
| if (IS_ERR(newxprt)) { |
| module_put(xcl->xcl_owner); |
| return PTR_ERR(newxprt); |
| } |
| |
| clear_bit(XPT_TEMP, &newxprt->xpt_flags); |
| spin_lock_bh(&serv->sv_lock); |
| list_add(&newxprt->xpt_list, &serv->sv_permsocks); |
| spin_unlock_bh(&serv->sv_lock); |
| newport = svc_xprt_local_port(newxprt); |
| clear_bit(XPT_BUSY, &newxprt->xpt_flags); |
| return newport; |
| } |
| err: |
| spin_unlock(&svc_xprt_class_lock); |
| dprintk("svc: transport %s not found\n", xprt_name); |
| |
| /* This errno is exposed to user space. Provide a reasonable |
| * perror msg for a bad transport. */ |
| return -EPROTONOSUPPORT; |
| } |
| EXPORT_SYMBOL_GPL(svc_create_xprt); |
| |
| /* |
| * Copy the local and remote xprt addresses to the rqstp structure |
| */ |
| void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) |
| { |
| struct sockaddr *sin; |
| |
| memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); |
| rqstp->rq_addrlen = xprt->xpt_remotelen; |
| |
| /* |
| * Destination address in request is needed for binding the |
| * source address in RPC replies/callbacks later. |
| */ |
| sin = (struct sockaddr *)&xprt->xpt_local; |
| switch (sin->sa_family) { |
| case AF_INET: |
| rqstp->rq_daddr.addr = ((struct sockaddr_in *)sin)->sin_addr; |
| break; |
| case AF_INET6: |
| rqstp->rq_daddr.addr6 = ((struct sockaddr_in6 *)sin)->sin6_addr; |
| break; |
| } |
| } |
| EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); |
| |
| /** |
| * svc_print_addr - Format rq_addr field for printing |
| * @rqstp: svc_rqst struct containing address to print |
| * @buf: target buffer for formatted address |
| * @len: length of target buffer |
| * |
| */ |
| char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) |
| { |
| return __svc_print_addr(svc_addr(rqstp), buf, len); |
| } |
| EXPORT_SYMBOL_GPL(svc_print_addr); |
| |
| /* |
| * Queue up an idle server thread. Must have pool->sp_lock held. |
| * Note: this is really a stack rather than a queue, so that we only |
| * use as many different threads as we need, and the rest don't pollute |
| * the cache. |
| */ |
| static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp) |
| { |
| list_add(&rqstp->rq_list, &pool->sp_threads); |
| } |
| |
| /* |
| * Dequeue an nfsd thread. Must have pool->sp_lock held. |
| */ |
| static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp) |
| { |
| list_del(&rqstp->rq_list); |
| } |
| |
| static bool svc_xprt_has_something_to_do(struct svc_xprt *xprt) |
| { |
| if (xprt->xpt_flags & ((1<<XPT_CONN)|(1<<XPT_CLOSE))) |
| return true; |
| if (xprt->xpt_flags & ((1<<XPT_DATA)|(1<<XPT_DEFERRED))) |
| return xprt->xpt_ops->xpo_has_wspace(xprt); |
| return false; |
| } |
| |
| /* |
| * Queue up a transport with data pending. If there are idle nfsd |
| * processes, wake 'em up. |
| * |
| */ |
| void svc_xprt_enqueue(struct svc_xprt *xprt) |
| { |
| struct svc_serv *serv = xprt->xpt_server; |
| struct svc_pool *pool; |
| struct svc_rqst *rqstp; |
| int cpu; |
| |
| if (!svc_xprt_has_something_to_do(xprt)) |
| return; |
| |
| cpu = get_cpu(); |
| pool = svc_pool_for_cpu(xprt->xpt_server, cpu); |
| put_cpu(); |
| |
| spin_lock_bh(&pool->sp_lock); |
| |
| if (!list_empty(&pool->sp_threads) && |
| !list_empty(&pool->sp_sockets)) |
| printk(KERN_ERR |
| "svc_xprt_enqueue: " |
| "threads and transports both waiting??\n"); |
| |
| pool->sp_stats.packets++; |
| |
| /* Mark transport as busy. It will remain in this state until |
| * the provider calls svc_xprt_received. We update XPT_BUSY |
| * atomically because it also guards against trying to enqueue |
| * the transport twice. |
| */ |
| if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) { |
| /* Don't enqueue transport while already enqueued */ |
| dprintk("svc: transport %p busy, not enqueued\n", xprt); |
| goto out_unlock; |
| } |
| |
| if (!list_empty(&pool->sp_threads)) { |
| rqstp = list_entry(pool->sp_threads.next, |
| struct svc_rqst, |
| rq_list); |
| dprintk("svc: transport %p served by daemon %p\n", |
| xprt, rqstp); |
| svc_thread_dequeue(pool, rqstp); |
| if (rqstp->rq_xprt) |
| printk(KERN_ERR |
| "svc_xprt_enqueue: server %p, rq_xprt=%p!\n", |
| rqstp, rqstp->rq_xprt); |
| rqstp->rq_xprt = xprt; |
| svc_xprt_get(xprt); |
| rqstp->rq_reserved = serv->sv_max_mesg; |
| atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); |
| pool->sp_stats.threads_woken++; |
| wake_up(&rqstp->rq_wait); |
| } else { |
| dprintk("svc: transport %p put into queue\n", xprt); |
| list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); |
| pool->sp_stats.sockets_queued++; |
| } |
| |
| out_unlock: |
| spin_unlock_bh(&pool->sp_lock); |
| } |
| EXPORT_SYMBOL_GPL(svc_xprt_enqueue); |
| |
| /* |
| * Dequeue the first transport. Must be called with the pool->sp_lock held. |
| */ |
| static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) |
| { |
| struct svc_xprt *xprt; |
| |
| if (list_empty(&pool->sp_sockets)) |
| return NULL; |
| |
| xprt = list_entry(pool->sp_sockets.next, |
| struct svc_xprt, xpt_ready); |
| list_del_init(&xprt->xpt_ready); |
| |
| dprintk("svc: transport %p dequeued, inuse=%d\n", |
| xprt, atomic_read(&xprt->xpt_ref.refcount)); |
| |
| return xprt; |
| } |
| |
| /* |
| * svc_xprt_received conditionally queues the transport for processing |
| * by another thread. The caller must hold the XPT_BUSY bit and must |
| * not thereafter touch transport data. |
| * |
| * Note: XPT_DATA only gets cleared when a read-attempt finds no (or |
| * insufficient) data. |
| */ |
| void svc_xprt_received(struct svc_xprt *xprt) |
| { |
| BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags)); |
| /* As soon as we clear busy, the xprt could be closed and |
| * 'put', so we need a reference to call svc_xprt_enqueue with: |
| */ |
| svc_xprt_get(xprt); |
| clear_bit(XPT_BUSY, &xprt->xpt_flags); |
| svc_xprt_enqueue(xprt); |
| svc_xprt_put(xprt); |
| } |
| EXPORT_SYMBOL_GPL(svc_xprt_received); |
| |
| /** |
| * svc_reserve - change the space reserved for the reply to a request. |
| * @rqstp: The request in question |
| * @space: new max space to reserve |
| * |
| * Each request reserves some space on the output queue of the transport |
| * to make sure the reply fits. This function reduces that reserved |
| * space to be the amount of space used already, plus @space. |
| * |
| */ |
| void svc_reserve(struct svc_rqst *rqstp, int space) |
| { |
| space += rqstp->rq_res.head[0].iov_len; |
| |
| if (space < rqstp->rq_reserved) { |
| struct svc_xprt *xprt = rqstp->rq_xprt; |
| atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved); |
| rqstp->rq_reserved = space; |
| |
| svc_xprt_enqueue(xprt); |
| } |
| } |
| EXPORT_SYMBOL_GPL(svc_reserve); |
| |
| static void svc_xprt_release(struct svc_rqst *rqstp) |
| { |
| struct svc_xprt *xprt = rqstp->rq_xprt; |
| |
| rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); |
| |
| kfree(rqstp->rq_deferred); |
| rqstp->rq_deferred = NULL; |
| |
| svc_free_res_pages(rqstp); |
| rqstp->rq_res.page_len = 0; |
| rqstp->rq_res.page_base = 0; |
| |
| /* Reset response buffer and release |
| * the reservation. |
| * But first, check that enough space was reserved |
| * for the reply, otherwise we have a bug! |
| */ |
| if ((rqstp->rq_res.len) > rqstp->rq_reserved) |
| printk(KERN_ERR "RPC request reserved %d but used %d\n", |
| rqstp->rq_reserved, |
| rqstp->rq_res.len); |
| |
| rqstp->rq_res.head[0].iov_len = 0; |
| svc_reserve(rqstp, 0); |
| rqstp->rq_xprt = NULL; |
| |
| svc_xprt_put(xprt); |
| } |
| |
| /* |
| * External function to wake up a server waiting for data |
| * This really only makes sense for services like lockd |
| * which have exactly one thread anyway. |
| */ |
| void svc_wake_up(struct svc_serv *serv) |
| { |
| struct svc_rqst *rqstp; |
| unsigned int i; |
| struct svc_pool *pool; |
| |
| for (i = 0; i < serv->sv_nrpools; i++) { |
| pool = &serv->sv_pools[i]; |
| |
| spin_lock_bh(&pool->sp_lock); |
| if (!list_empty(&pool->sp_threads)) { |
| rqstp = list_entry(pool->sp_threads.next, |
| struct svc_rqst, |
| rq_list); |
| dprintk("svc: daemon %p woken up.\n", rqstp); |
| /* |
| svc_thread_dequeue(pool, rqstp); |
| rqstp->rq_xprt = NULL; |
| */ |
| wake_up(&rqstp->rq_wait); |
| } |
| spin_unlock_bh(&pool->sp_lock); |
| } |
| } |
| EXPORT_SYMBOL_GPL(svc_wake_up); |
| |
| int svc_port_is_privileged(struct sockaddr *sin) |
| { |
| switch (sin->sa_family) { |
| case AF_INET: |
| return ntohs(((struct sockaddr_in *)sin)->sin_port) |
| < PROT_SOCK; |
| case AF_INET6: |
| return ntohs(((struct sockaddr_in6 *)sin)->sin6_port) |
| < PROT_SOCK; |
| default: |
| return 0; |
| } |
| } |
| |
| /* |
| * Make sure that we don't have too many active connections. If we have, |
| * something must be dropped. It's not clear what will happen if we allow |
| * "too many" connections, but when dealing with network-facing software, |
| * we have to code defensively. Here we do that by imposing hard limits. |
| * |
| * There's no point in trying to do random drop here for DoS |
| * prevention. The NFS clients does 1 reconnect in 15 seconds. An |
| * attacker can easily beat that. |
| * |
| * The only somewhat efficient mechanism would be if drop old |
| * connections from the same IP first. But right now we don't even |
| * record the client IP in svc_sock. |
| * |
| * single-threaded services that expect a lot of clients will probably |
| * need to set sv_maxconn to override the default value which is based |
| * on the number of threads |
| */ |
| static void svc_check_conn_limits(struct svc_serv *serv) |
| { |
| unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : |
| (serv->sv_nrthreads+3) * 20; |
| |
| if (serv->sv_tmpcnt > limit) { |
| struct svc_xprt *xprt = NULL; |
| spin_lock_bh(&serv->sv_lock); |
| if (!list_empty(&serv->sv_tempsocks)) { |
| if (net_ratelimit()) { |
| /* Try to help the admin */ |
| printk(KERN_NOTICE "%s: too many open " |
| "connections, consider increasing %s\n", |
| serv->sv_name, serv->sv_maxconn ? |
| "the max number of connections." : |
| "the number of threads."); |
| } |
| /* |
| * Always select the oldest connection. It's not fair, |
| * but so is life |
| */ |
| xprt = list_entry(serv->sv_tempsocks.prev, |
| struct svc_xprt, |
| xpt_list); |
| set_bit(XPT_CLOSE, &xprt->xpt_flags); |
| svc_xprt_get(xprt); |
| } |
| spin_unlock_bh(&serv->sv_lock); |
| |
| if (xprt) { |
| svc_xprt_enqueue(xprt); |
| svc_xprt_put(xprt); |
| } |
| } |
| } |
| |
| /* |
| * Receive the next request on any transport. This code is carefully |
| * organised not to touch any cachelines in the shared svc_serv |
| * structure, only cachelines in the local svc_pool. |
| */ |
| int svc_recv(struct svc_rqst *rqstp, long timeout) |
| { |
| struct svc_xprt *xprt = NULL; |
| struct svc_serv *serv = rqstp->rq_server; |
| struct svc_pool *pool = rqstp->rq_pool; |
| int len, i; |
| int pages; |
| struct xdr_buf *arg; |
| DECLARE_WAITQUEUE(wait, current); |
| long time_left; |
| |
| dprintk("svc: server %p waiting for data (to = %ld)\n", |
| rqstp, timeout); |
| |
| if (rqstp->rq_xprt) |
| printk(KERN_ERR |
| "svc_recv: service %p, transport not NULL!\n", |
| rqstp); |
| if (waitqueue_active(&rqstp->rq_wait)) |
| printk(KERN_ERR |
| "svc_recv: service %p, wait queue active!\n", |
| rqstp); |
| |
| /* now allocate needed pages. If we get a failure, sleep briefly */ |
| pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE; |
| for (i = 0; i < pages ; i++) |
| while (rqstp->rq_pages[i] == NULL) { |
| struct page *p = alloc_page(GFP_KERNEL); |
| if (!p) { |
| set_current_state(TASK_INTERRUPTIBLE); |
| if (signalled() || kthread_should_stop()) { |
| set_current_state(TASK_RUNNING); |
| return -EINTR; |
| } |
| schedule_timeout(msecs_to_jiffies(500)); |
| } |
| rqstp->rq_pages[i] = p; |
| } |
| rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */ |
| BUG_ON(pages >= RPCSVC_MAXPAGES); |
| |
| /* Make arg->head point to first page and arg->pages point to rest */ |
| arg = &rqstp->rq_arg; |
| arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); |
| arg->head[0].iov_len = PAGE_SIZE; |
| arg->pages = rqstp->rq_pages + 1; |
| arg->page_base = 0; |
| /* save at least one page for response */ |
| arg->page_len = (pages-2)*PAGE_SIZE; |
| arg->len = (pages-1)*PAGE_SIZE; |
| arg->tail[0].iov_len = 0; |
| |
| try_to_freeze(); |
| cond_resched(); |
| if (signalled() || kthread_should_stop()) |
| return -EINTR; |
| |
| /* Normally we will wait up to 5 seconds for any required |
| * cache information to be provided. |
| */ |
| rqstp->rq_chandle.thread_wait = 5*HZ; |
| |
| spin_lock_bh(&pool->sp_lock); |
| xprt = svc_xprt_dequeue(pool); |
| if (xprt) { |
| rqstp->rq_xprt = xprt; |
| svc_xprt_get(xprt); |
| rqstp->rq_reserved = serv->sv_max_mesg; |
| atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); |
| |
| /* As there is a shortage of threads and this request |
| * had to be queued, don't allow the thread to wait so |
| * long for cache updates. |
| */ |
| rqstp->rq_chandle.thread_wait = 1*HZ; |
| } else { |
| /* No data pending. Go to sleep */ |
| svc_thread_enqueue(pool, rqstp); |
| |
| /* |
| * We have to be able to interrupt this wait |
| * to bring down the daemons ... |
| */ |
| set_current_state(TASK_INTERRUPTIBLE); |
| |
| /* |
| * checking kthread_should_stop() here allows us to avoid |
| * locking and signalling when stopping kthreads that call |
| * svc_recv. If the thread has already been woken up, then |
| * we can exit here without sleeping. If not, then it |
| * it'll be woken up quickly during the schedule_timeout |
| */ |
| if (kthread_should_stop()) { |
| set_current_state(TASK_RUNNING); |
| spin_unlock_bh(&pool->sp_lock); |
| return -EINTR; |
| } |
| |
| add_wait_queue(&rqstp->rq_wait, &wait); |
| spin_unlock_bh(&pool->sp_lock); |
| |
| time_left = schedule_timeout(timeout); |
| |
| try_to_freeze(); |
| |
| spin_lock_bh(&pool->sp_lock); |
| remove_wait_queue(&rqstp->rq_wait, &wait); |
| if (!time_left) |
| pool->sp_stats.threads_timedout++; |
| |
| xprt = rqstp->rq_xprt; |
| if (!xprt) { |
| svc_thread_dequeue(pool, rqstp); |
| spin_unlock_bh(&pool->sp_lock); |
| dprintk("svc: server %p, no data yet\n", rqstp); |
| if (signalled() || kthread_should_stop()) |
| return -EINTR; |
| else |
| return -EAGAIN; |
| } |
| } |
| spin_unlock_bh(&pool->sp_lock); |
| |
| len = 0; |
| if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { |
| dprintk("svc_recv: found XPT_CLOSE\n"); |
| svc_delete_xprt(xprt); |
| /* Leave XPT_BUSY set on the dead xprt: */ |
| goto out; |
| } |
| if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { |
| struct svc_xprt *newxpt; |
| newxpt = xprt->xpt_ops->xpo_accept(xprt); |
| if (newxpt) { |
| /* |
| * We know this module_get will succeed because the |
| * listener holds a reference too |
| */ |
| __module_get(newxpt->xpt_class->xcl_owner); |
| svc_check_conn_limits(xprt->xpt_server); |
| spin_lock_bh(&serv->sv_lock); |
| set_bit(XPT_TEMP, &newxpt->xpt_flags); |
| list_add(&newxpt->xpt_list, &serv->sv_tempsocks); |
| serv->sv_tmpcnt++; |
| if (serv->sv_temptimer.function == NULL) { |
| /* setup timer to age temp transports */ |
| setup_timer(&serv->sv_temptimer, |
| svc_age_temp_xprts, |
| (unsigned long)serv); |
| mod_timer(&serv->sv_temptimer, |
| jiffies + svc_conn_age_period * HZ); |
| } |
| spin_unlock_bh(&serv->sv_lock); |
| svc_xprt_received(newxpt); |
| } |
| } else if (xprt->xpt_ops->xpo_has_wspace(xprt)) { |
| dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", |
| rqstp, pool->sp_id, xprt, |
| atomic_read(&xprt->xpt_ref.refcount)); |
| rqstp->rq_deferred = svc_deferred_dequeue(xprt); |
| if (rqstp->rq_deferred) |
| len = svc_deferred_recv(rqstp); |
| else |
| len = xprt->xpt_ops->xpo_recvfrom(rqstp); |
| dprintk("svc: got len=%d\n", len); |
| } |
| svc_xprt_received(xprt); |
| |
| /* No data, incomplete (TCP) read, or accept() */ |
| if (len == 0 || len == -EAGAIN) |
| goto out; |
| |
| clear_bit(XPT_OLD, &xprt->xpt_flags); |
| |
| rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp)); |
| rqstp->rq_chandle.defer = svc_defer; |
| |
| if (serv->sv_stats) |
| serv->sv_stats->netcnt++; |
| return len; |
| out: |
| rqstp->rq_res.len = 0; |
| svc_xprt_release(rqstp); |
| return -EAGAIN; |
| } |
| EXPORT_SYMBOL_GPL(svc_recv); |
| |
| /* |
| * Drop request |
| */ |
| void svc_drop(struct svc_rqst *rqstp) |
| { |
| dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt); |
| svc_xprt_release(rqstp); |
| } |
| EXPORT_SYMBOL_GPL(svc_drop); |
| |
| /* |
| * Return reply to client. |
| */ |
| int svc_send(struct svc_rqst *rqstp) |
| { |
| struct svc_xprt *xprt; |
| int len; |
| struct xdr_buf *xb; |
| |
| xprt = rqstp->rq_xprt; |
| if (!xprt) |
| return -EFAULT; |
| |
| /* release the receive skb before sending the reply */ |
| rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); |
| |
| /* calculate over-all length */ |
| xb = &rqstp->rq_res; |
| xb->len = xb->head[0].iov_len + |
| xb->page_len + |
| xb->tail[0].iov_len; |
| |
| /* Grab mutex to serialize outgoing data. */ |
| mutex_lock(&xprt->xpt_mutex); |
| if (test_bit(XPT_DEAD, &xprt->xpt_flags)) |
| len = -ENOTCONN; |
| else |
| len = xprt->xpt_ops->xpo_sendto(rqstp); |
| mutex_unlock(&xprt->xpt_mutex); |
| rpc_wake_up(&xprt->xpt_bc_pending); |
| svc_xprt_release(rqstp); |
| |
| if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN) |
| return 0; |
| return len; |
| } |
| |
| /* |
| * Timer function to close old temporary transports, using |
| * a mark-and-sweep algorithm. |
| */ |
| static void svc_age_temp_xprts(unsigned long closure) |
| { |
| struct svc_serv *serv = (struct svc_serv *)closure; |
| struct svc_xprt *xprt; |
| struct list_head *le, *next; |
| LIST_HEAD(to_be_aged); |
| |
| dprintk("svc_age_temp_xprts\n"); |
| |
| if (!spin_trylock_bh(&serv->sv_lock)) { |
| /* busy, try again 1 sec later */ |
| dprintk("svc_age_temp_xprts: busy\n"); |
| mod_timer(&serv->sv_temptimer, jiffies + HZ); |
| return; |
| } |
| |
| list_for_each_safe(le, next, &serv->sv_tempsocks) { |
| xprt = list_entry(le, struct svc_xprt, xpt_list); |
| |
| /* First time through, just mark it OLD. Second time |
| * through, close it. */ |
| if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) |
| continue; |
| if (atomic_read(&xprt->xpt_ref.refcount) > 1 || |
| test_bit(XPT_BUSY, &xprt->xpt_flags)) |
| continue; |
| svc_xprt_get(xprt); |
| list_move(le, &to_be_aged); |
| set_bit(XPT_CLOSE, &xprt->xpt_flags); |
| set_bit(XPT_DETACHED, &xprt->xpt_flags); |
| } |
| spin_unlock_bh(&serv->sv_lock); |
| |
| while (!list_empty(&to_be_aged)) { |
| le = to_be_aged.next; |
| /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */ |
| list_del_init(le); |
| xprt = list_entry(le, struct svc_xprt, xpt_list); |
| |
| dprintk("queuing xprt %p for closing\n", xprt); |
| |
| /* a thread will dequeue and close it soon */ |
| svc_xprt_enqueue(xprt); |
| svc_xprt_put(xprt); |
| } |
| |
| mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); |
| } |
| |
| static void call_xpt_users(struct svc_xprt *xprt) |
| { |
| struct svc_xpt_user *u; |
| |
| spin_lock(&xprt->xpt_lock); |
| while (!list_empty(&xprt->xpt_users)) { |
| u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list); |
| list_del(&u->list); |
| u->callback(u); |
| } |
| spin_unlock(&xprt->xpt_lock); |
| } |
| |
| /* |
| * Remove a dead transport |
| */ |
| void svc_delete_xprt(struct svc_xprt *xprt) |
| { |
| struct svc_serv *serv = xprt->xpt_server; |
| struct svc_deferred_req *dr; |
| |
| /* Only do this once */ |
| if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) |
| BUG(); |
| |
| dprintk("svc: svc_delete_xprt(%p)\n", xprt); |
| xprt->xpt_ops->xpo_detach(xprt); |
| |
| spin_lock_bh(&serv->sv_lock); |
| if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags)) |
| list_del_init(&xprt->xpt_list); |
| BUG_ON(!list_empty(&xprt->xpt_ready)); |
| if (test_bit(XPT_TEMP, &xprt->xpt_flags)) |
| serv->sv_tmpcnt--; |
| spin_unlock_bh(&serv->sv_lock); |
| |
| while ((dr = svc_deferred_dequeue(xprt)) != NULL) |
| kfree(dr); |
| |
| call_xpt_users(xprt); |
| svc_xprt_put(xprt); |
| } |
| |
| void svc_close_xprt(struct svc_xprt *xprt) |
| { |
| set_bit(XPT_CLOSE, &xprt->xpt_flags); |
| if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) |
| /* someone else will have to effect the close */ |
| return; |
| /* |
| * We expect svc_close_xprt() to work even when no threads are |
| * running (e.g., while configuring the server before starting |
| * any threads), so if the transport isn't busy, we delete |
| * it ourself: |
| */ |
| svc_delete_xprt(xprt); |
| } |
| EXPORT_SYMBOL_GPL(svc_close_xprt); |
| |
| static void svc_close_list(struct list_head *xprt_list) |
| { |
| struct svc_xprt *xprt; |
| |
| list_for_each_entry(xprt, xprt_list, xpt_list) { |
| set_bit(XPT_CLOSE, &xprt->xpt_flags); |
| set_bit(XPT_BUSY, &xprt->xpt_flags); |
| } |
| } |
| |
| void svc_close_all(struct svc_serv *serv) |
| { |
| struct svc_pool *pool; |
| struct svc_xprt *xprt; |
| struct svc_xprt *tmp; |
| int i; |
| |
| svc_close_list(&serv->sv_tempsocks); |
| svc_close_list(&serv->sv_permsocks); |
| |
| for (i = 0; i < serv->sv_nrpools; i++) { |
| pool = &serv->sv_pools[i]; |
| |
| spin_lock_bh(&pool->sp_lock); |
| while (!list_empty(&pool->sp_sockets)) { |
| xprt = list_first_entry(&pool->sp_sockets, struct svc_xprt, xpt_ready); |
| list_del_init(&xprt->xpt_ready); |
| } |
| spin_unlock_bh(&pool->sp_lock); |
| } |
| /* |
| * At this point the sp_sockets lists will stay empty, since |
| * svc_enqueue will not add new entries without taking the |
| * sp_lock and checking XPT_BUSY. |
| */ |
| list_for_each_entry_safe(xprt, tmp, &serv->sv_tempsocks, xpt_list) |
| svc_delete_xprt(xprt); |
| list_for_each_entry_safe(xprt, tmp, &serv->sv_permsocks, xpt_list) |
| svc_delete_xprt(xprt); |
| |
| BUG_ON(!list_empty(&serv->sv_permsocks)); |
| BUG_ON(!list_empty(&serv->sv_tempsocks)); |
| } |
| |
| /* |
| * Handle defer and revisit of requests |
| */ |
| |
| static void svc_revisit(struct cache_deferred_req *dreq, int too_many) |
| { |
| struct svc_deferred_req *dr = |
| container_of(dreq, struct svc_deferred_req, handle); |
| struct svc_xprt *xprt = dr->xprt; |
| |
| spin_lock(&xprt->xpt_lock); |
| set_bit(XPT_DEFERRED, &xprt->xpt_flags); |
| if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) { |
| spin_unlock(&xprt->xpt_lock); |
| dprintk("revisit canceled\n"); |
| svc_xprt_put(xprt); |
| kfree(dr); |
| return; |
| } |
| dprintk("revisit queued\n"); |
| dr->xprt = NULL; |
| list_add(&dr->handle.recent, &xprt->xpt_deferred); |
| spin_unlock(&xprt->xpt_lock); |
| svc_xprt_enqueue(xprt); |
| svc_xprt_put(xprt); |
| } |
| |
| /* |
| * Save the request off for later processing. The request buffer looks |
| * like this: |
| * |
| * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> |
| * |
| * This code can only handle requests that consist of an xprt-header |
| * and rpc-header. |
| */ |
| static struct cache_deferred_req *svc_defer(struct cache_req *req) |
| { |
| struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); |
| struct svc_deferred_req *dr; |
| |
| if (rqstp->rq_arg.page_len || !rqstp->rq_usedeferral) |
| return NULL; /* if more than a page, give up FIXME */ |
| if (rqstp->rq_deferred) { |
| dr = rqstp->rq_deferred; |
| rqstp->rq_deferred = NULL; |
| } else { |
| size_t skip; |
| size_t size; |
| /* FIXME maybe discard if size too large */ |
| size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; |
| dr = kmalloc(size, GFP_KERNEL); |
| if (dr == NULL) |
| return NULL; |
| |
| dr->handle.owner = rqstp->rq_server; |
| dr->prot = rqstp->rq_prot; |
| memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); |
| dr->addrlen = rqstp->rq_addrlen; |
| dr->daddr = rqstp->rq_daddr; |
| dr->argslen = rqstp->rq_arg.len >> 2; |
| dr->xprt_hlen = rqstp->rq_xprt_hlen; |
| |
| /* back up head to the start of the buffer and copy */ |
| skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; |
| memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, |
| dr->argslen << 2); |
| } |
| svc_xprt_get(rqstp->rq_xprt); |
| dr->xprt = rqstp->rq_xprt; |
| rqstp->rq_dropme = true; |
| |
| dr->handle.revisit = svc_revisit; |
| return &dr->handle; |
| } |
| |
| /* |
| * recv data from a deferred request into an active one |
| */ |
| static int svc_deferred_recv(struct svc_rqst *rqstp) |
| { |
| struct svc_deferred_req *dr = rqstp->rq_deferred; |
| |
| /* setup iov_base past transport header */ |
| rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2); |
| /* The iov_len does not include the transport header bytes */ |
| rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen; |
| rqstp->rq_arg.page_len = 0; |
| /* The rq_arg.len includes the transport header bytes */ |
| rqstp->rq_arg.len = dr->argslen<<2; |
| rqstp->rq_prot = dr->prot; |
| memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); |
| rqstp->rq_addrlen = dr->addrlen; |
| /* Save off transport header len in case we get deferred again */ |
| rqstp->rq_xprt_hlen = dr->xprt_hlen; |
| rqstp->rq_daddr = dr->daddr; |
| rqstp->rq_respages = rqstp->rq_pages; |
| return (dr->argslen<<2) - dr->xprt_hlen; |
| } |
| |
| |
| static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) |
| { |
| struct svc_deferred_req *dr = NULL; |
| |
| if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) |
| return NULL; |
| spin_lock(&xprt->xpt_lock); |
| if (!list_empty(&xprt->xpt_deferred)) { |
| dr = list_entry(xprt->xpt_deferred.next, |
| struct svc_deferred_req, |
| handle.recent); |
| list_del_init(&dr->handle.recent); |
| } else |
| clear_bit(XPT_DEFERRED, &xprt->xpt_flags); |
| spin_unlock(&xprt->xpt_lock); |
| return dr; |
| } |
| |
| /** |
| * svc_find_xprt - find an RPC transport instance |
| * @serv: pointer to svc_serv to search |
| * @xcl_name: C string containing transport's class name |
| * @af: Address family of transport's local address |
| * @port: transport's IP port number |
| * |
| * Return the transport instance pointer for the endpoint accepting |
| * connections/peer traffic from the specified transport class, |
| * address family and port. |
| * |
| * Specifying 0 for the address family or port is effectively a |
| * wild-card, and will result in matching the first transport in the |
| * service's list that has a matching class name. |
| */ |
| struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name, |
| const sa_family_t af, const unsigned short port) |
| { |
| struct svc_xprt *xprt; |
| struct svc_xprt *found = NULL; |
| |
| /* Sanity check the args */ |
| if (serv == NULL || xcl_name == NULL) |
| return found; |
| |
| spin_lock_bh(&serv->sv_lock); |
| list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { |
| if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) |
| continue; |
| if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) |
| continue; |
| if (port != 0 && port != svc_xprt_local_port(xprt)) |
| continue; |
| found = xprt; |
| svc_xprt_get(xprt); |
| break; |
| } |
| spin_unlock_bh(&serv->sv_lock); |
| return found; |
| } |
| EXPORT_SYMBOL_GPL(svc_find_xprt); |
| |
| static int svc_one_xprt_name(const struct svc_xprt *xprt, |
| char *pos, int remaining) |
| { |
| int len; |
| |
| len = snprintf(pos, remaining, "%s %u\n", |
| xprt->xpt_class->xcl_name, |
| svc_xprt_local_port(xprt)); |
| if (len >= remaining) |
| return -ENAMETOOLONG; |
| return len; |
| } |
| |
| /** |
| * svc_xprt_names - format a buffer with a list of transport names |
| * @serv: pointer to an RPC service |
| * @buf: pointer to a buffer to be filled in |
| * @buflen: length of buffer to be filled in |
| * |
| * Fills in @buf with a string containing a list of transport names, |
| * each name terminated with '\n'. |
| * |
| * Returns positive length of the filled-in string on success; otherwise |
| * a negative errno value is returned if an error occurs. |
| */ |
| int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen) |
| { |
| struct svc_xprt *xprt; |
| int len, totlen; |
| char *pos; |
| |
| /* Sanity check args */ |
| if (!serv) |
| return 0; |
| |
| spin_lock_bh(&serv->sv_lock); |
| |
| pos = buf; |
| totlen = 0; |
| list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { |
| len = svc_one_xprt_name(xprt, pos, buflen - totlen); |
| if (len < 0) { |
| *buf = '\0'; |
| totlen = len; |
| } |
| if (len <= 0) |
| break; |
| |
| pos += len; |
| totlen += len; |
| } |
| |
| spin_unlock_bh(&serv->sv_lock); |
| return totlen; |
| } |
| EXPORT_SYMBOL_GPL(svc_xprt_names); |
| |
| |
| /*----------------------------------------------------------------------------*/ |
| |
| static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos) |
| { |
| unsigned int pidx = (unsigned int)*pos; |
| struct svc_serv *serv = m->private; |
| |
| dprintk("svc_pool_stats_start, *pidx=%u\n", pidx); |
| |
| if (!pidx) |
| return SEQ_START_TOKEN; |
| return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]); |
| } |
| |
| static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos) |
| { |
| struct svc_pool *pool = p; |
| struct svc_serv *serv = m->private; |
| |
| dprintk("svc_pool_stats_next, *pos=%llu\n", *pos); |
| |
| if (p == SEQ_START_TOKEN) { |
| pool = &serv->sv_pools[0]; |
| } else { |
| unsigned int pidx = (pool - &serv->sv_pools[0]); |
| if (pidx < serv->sv_nrpools-1) |
| pool = &serv->sv_pools[pidx+1]; |
| else |
| pool = NULL; |
| } |
| ++*pos; |
| return pool; |
| } |
| |
| static void svc_pool_stats_stop(struct seq_file *m, void *p) |
| { |
| } |
| |
| static int svc_pool_stats_show(struct seq_file *m, void *p) |
| { |
| struct svc_pool *pool = p; |
| |
| if (p == SEQ_START_TOKEN) { |
| seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n"); |
| return 0; |
| } |
| |
| seq_printf(m, "%u %lu %lu %lu %lu\n", |
| pool->sp_id, |
| pool->sp_stats.packets, |
| pool->sp_stats.sockets_queued, |
| pool->sp_stats.threads_woken, |
| pool->sp_stats.threads_timedout); |
| |
| return 0; |
| } |
| |
| static const struct seq_operations svc_pool_stats_seq_ops = { |
| .start = svc_pool_stats_start, |
| .next = svc_pool_stats_next, |
| .stop = svc_pool_stats_stop, |
| .show = svc_pool_stats_show, |
| }; |
| |
| int svc_pool_stats_open(struct svc_serv *serv, struct file *file) |
| { |
| int err; |
| |
| err = seq_open(file, &svc_pool_stats_seq_ops); |
| if (!err) |
| ((struct seq_file *) file->private_data)->private = serv; |
| return err; |
| } |
| EXPORT_SYMBOL(svc_pool_stats_open); |
| |
| /*----------------------------------------------------------------------------*/ |