| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * linux/net/sunrpc/svc_xprt.c |
| * |
| * Author: Tom Tucker <tom@opengridcomputing.com> |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/sched/mm.h> |
| #include <linux/errno.h> |
| #include <linux/freezer.h> |
| #include <linux/kthread.h> |
| #include <linux/slab.h> |
| #include <net/sock.h> |
| #include <linux/sunrpc/addr.h> |
| #include <linux/sunrpc/stats.h> |
| #include <linux/sunrpc/svc_xprt.h> |
| #include <linux/sunrpc/svcsock.h> |
| #include <linux/sunrpc/xprt.h> |
| #include <linux/module.h> |
| #include <linux/netdevice.h> |
| #include <trace/events/sunrpc.h> |
| |
| #define RPCDBG_FACILITY RPCDBG_SVCXPRT |
| |
| static unsigned int svc_rpc_per_connection_limit __read_mostly; |
| module_param(svc_rpc_per_connection_limit, uint, 0644); |
| |
| |
| 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(struct timer_list *t); |
| static void svc_delete_xprt(struct svc_xprt *xprt); |
| |
| /* apparently the "standard" is that clients close |
| * idle connections after 5 minutes, servers after |
| * 6 minutes |
| * http://nfsv4bat.org/Documents/ConnectAThon/1996/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. |
| * The "service mutex" 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); |
| |
| /** |
| * svc_print_xprts - Format the transport list for printing |
| * @buf: target buffer for formatted address |
| * @maxlen: length of target buffer |
| * |
| * Fills in @buf with a string containing a list of transport names, each name |
| * terminated with '\n'. If the buffer is too small, some entries may be |
| * missing, but it is guaranteed that all lines in the output buffer are |
| * complete. |
| * |
| * Returns positive length of the filled-in string. |
| */ |
| 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; |
| |
| slen = snprintf(tmpstr, sizeof(tmpstr), "%s %d\n", |
| xcl->xcl_name, xcl->xcl_max_payload); |
| if (slen >= sizeof(tmpstr) || len + slen >= maxlen) |
| break; |
| len += slen; |
| strcat(buf, tmpstr); |
| } |
| spin_unlock(&svc_xprt_class_lock); |
| |
| return len; |
| } |
| |
| /** |
| * svc_xprt_deferred_close - Close a transport |
| * @xprt: transport instance |
| * |
| * Used in contexts that need to defer the work of shutting down |
| * the transport to an nfsd thread. |
| */ |
| void svc_xprt_deferred_close(struct svc_xprt *xprt) |
| { |
| if (!test_and_set_bit(XPT_CLOSE, &xprt->xpt_flags)) |
| svc_xprt_enqueue(xprt); |
| } |
| EXPORT_SYMBOL_GPL(svc_xprt_deferred_close); |
| |
| 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_cred(xprt->xpt_cred); |
| put_net_track(xprt->xpt_net, &xprt->ns_tracker); |
| /* See comment on corresponding get in xs_setup_bc_tcp(): */ |
| if (xprt->xpt_bc_xprt) |
| xprt_put(xprt->xpt_bc_xprt); |
| if (xprt->xpt_bc_xps) |
| xprt_switch_put(xprt->xpt_bc_xps); |
| trace_svc_xprt_free(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 net *net, 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); |
| xprt->xpt_net = get_net_track(net, &xprt->ns_tracker, GFP_ATOMIC); |
| strcpy(xprt->xpt_remotebuf, "uninitialized"); |
| } |
| 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 IS_ENABLED(CONFIG_IPV6) |
| struct sockaddr_in6 sin6 = { |
| .sin6_family = AF_INET6, |
| .sin6_addr = IN6ADDR_ANY_INIT, |
| .sin6_port = htons(port), |
| }; |
| #endif |
| struct svc_xprt *xprt; |
| struct sockaddr *sap; |
| size_t len; |
| |
| switch (family) { |
| case PF_INET: |
| sap = (struct sockaddr *)&sin; |
| len = sizeof(sin); |
| break; |
| #if IS_ENABLED(CONFIG_IPV6) |
| case PF_INET6: |
| sap = (struct sockaddr *)&sin6; |
| len = sizeof(sin6); |
| break; |
| #endif |
| default: |
| return ERR_PTR(-EAFNOSUPPORT); |
| } |
| |
| xprt = xcl->xcl_ops->xpo_create(serv, net, sap, len, flags); |
| if (IS_ERR(xprt)) |
| trace_svc_xprt_create_err(serv->sv_program->pg_name, |
| xcl->xcl_name, sap, len, xprt); |
| return xprt; |
| } |
| |
| /** |
| * svc_xprt_received - start next receiver thread |
| * @xprt: controlling transport |
| * |
| * 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) |
| { |
| if (!test_bit(XPT_BUSY, &xprt->xpt_flags)) { |
| WARN_ONCE(1, "xprt=0x%p already busy!", xprt); |
| return; |
| } |
| |
| /* 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); |
| smp_mb__before_atomic(); |
| clear_bit(XPT_BUSY, &xprt->xpt_flags); |
| svc_xprt_enqueue(xprt); |
| svc_xprt_put(xprt); |
| } |
| EXPORT_SYMBOL_GPL(svc_xprt_received); |
| |
| void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new) |
| { |
| clear_bit(XPT_TEMP, &new->xpt_flags); |
| spin_lock_bh(&serv->sv_lock); |
| list_add(&new->xpt_list, &serv->sv_permsocks); |
| spin_unlock_bh(&serv->sv_lock); |
| svc_xprt_received(new); |
| } |
| |
| static int _svc_xprt_create(struct svc_serv *serv, const char *xprt_name, |
| struct net *net, const int family, |
| const unsigned short port, int flags, |
| const struct cred *cred) |
| { |
| struct svc_xprt_class *xcl; |
| |
| 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); |
| } |
| newxprt->xpt_cred = get_cred(cred); |
| svc_add_new_perm_xprt(serv, newxprt); |
| newport = svc_xprt_local_port(newxprt); |
| return newport; |
| } |
| err: |
| spin_unlock(&svc_xprt_class_lock); |
| /* This errno is exposed to user space. Provide a reasonable |
| * perror msg for a bad transport. */ |
| return -EPROTONOSUPPORT; |
| } |
| |
| /** |
| * svc_xprt_create - Add a new listener to @serv |
| * @serv: target RPC service |
| * @xprt_name: transport class name |
| * @net: network namespace |
| * @family: network address family |
| * @port: listener port |
| * @flags: SVC_SOCK flags |
| * @cred: credential to bind to this transport |
| * |
| * Return values: |
| * %0: New listener added successfully |
| * %-EPROTONOSUPPORT: Requested transport type not supported |
| */ |
| int svc_xprt_create(struct svc_serv *serv, const char *xprt_name, |
| struct net *net, const int family, |
| const unsigned short port, int flags, |
| const struct cred *cred) |
| { |
| int err; |
| |
| err = _svc_xprt_create(serv, xprt_name, net, family, port, flags, cred); |
| if (err == -EPROTONOSUPPORT) { |
| request_module("svc%s", xprt_name); |
| err = _svc_xprt_create(serv, xprt_name, net, family, port, flags, cred); |
| } |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(svc_xprt_create); |
| |
| /* |
| * Copy the local and remote xprt addresses to the rqstp structure |
| */ |
| void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) |
| { |
| 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. |
| */ |
| memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen); |
| rqstp->rq_daddrlen = xprt->xpt_locallen; |
| } |
| 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); |
| |
| static bool svc_xprt_slots_in_range(struct svc_xprt *xprt) |
| { |
| unsigned int limit = svc_rpc_per_connection_limit; |
| int nrqsts = atomic_read(&xprt->xpt_nr_rqsts); |
| |
| return limit == 0 || (nrqsts >= 0 && nrqsts < limit); |
| } |
| |
| static bool svc_xprt_reserve_slot(struct svc_rqst *rqstp, struct svc_xprt *xprt) |
| { |
| if (!test_bit(RQ_DATA, &rqstp->rq_flags)) { |
| if (!svc_xprt_slots_in_range(xprt)) |
| return false; |
| atomic_inc(&xprt->xpt_nr_rqsts); |
| set_bit(RQ_DATA, &rqstp->rq_flags); |
| } |
| return true; |
| } |
| |
| static void svc_xprt_release_slot(struct svc_rqst *rqstp) |
| { |
| struct svc_xprt *xprt = rqstp->rq_xprt; |
| if (test_and_clear_bit(RQ_DATA, &rqstp->rq_flags)) { |
| atomic_dec(&xprt->xpt_nr_rqsts); |
| smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */ |
| svc_xprt_enqueue(xprt); |
| } |
| } |
| |
| static bool svc_xprt_ready(struct svc_xprt *xprt) |
| { |
| unsigned long xpt_flags; |
| |
| /* |
| * If another cpu has recently updated xpt_flags, |
| * sk_sock->flags, xpt_reserved, or xpt_nr_rqsts, we need to |
| * know about it; otherwise it's possible that both that cpu and |
| * this one could call svc_xprt_enqueue() without either |
| * svc_xprt_enqueue() recognizing that the conditions below |
| * are satisfied, and we could stall indefinitely: |
| */ |
| smp_rmb(); |
| xpt_flags = READ_ONCE(xprt->xpt_flags); |
| |
| if (xpt_flags & BIT(XPT_BUSY)) |
| return false; |
| if (xpt_flags & (BIT(XPT_CONN) | BIT(XPT_CLOSE))) |
| return true; |
| if (xpt_flags & (BIT(XPT_DATA) | BIT(XPT_DEFERRED))) { |
| if (xprt->xpt_ops->xpo_has_wspace(xprt) && |
| svc_xprt_slots_in_range(xprt)) |
| return true; |
| trace_svc_xprt_no_write_space(xprt); |
| return false; |
| } |
| return false; |
| } |
| |
| /** |
| * svc_xprt_enqueue - Queue a transport on an idle nfsd thread |
| * @xprt: transport with data pending |
| * |
| */ |
| void svc_xprt_enqueue(struct svc_xprt *xprt) |
| { |
| struct svc_pool *pool; |
| struct svc_rqst *rqstp = NULL; |
| |
| if (!svc_xprt_ready(xprt)) |
| return; |
| |
| /* 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)) |
| return; |
| |
| pool = svc_pool_for_cpu(xprt->xpt_server); |
| |
| percpu_counter_inc(&pool->sp_sockets_queued); |
| spin_lock_bh(&pool->sp_lock); |
| list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); |
| spin_unlock_bh(&pool->sp_lock); |
| |
| /* find a thread for this xprt */ |
| rcu_read_lock(); |
| list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { |
| if (test_and_set_bit(RQ_BUSY, &rqstp->rq_flags)) |
| continue; |
| percpu_counter_inc(&pool->sp_threads_woken); |
| rqstp->rq_qtime = ktime_get(); |
| wake_up_process(rqstp->rq_task); |
| goto out_unlock; |
| } |
| set_bit(SP_CONGESTED, &pool->sp_flags); |
| rqstp = NULL; |
| out_unlock: |
| rcu_read_unlock(); |
| trace_svc_xprt_enqueue(xprt, rqstp); |
| } |
| EXPORT_SYMBOL_GPL(svc_xprt_enqueue); |
| |
| /* |
| * Dequeue the first transport, if there is one. |
| */ |
| static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) |
| { |
| struct svc_xprt *xprt = NULL; |
| |
| if (list_empty(&pool->sp_sockets)) |
| goto out; |
| |
| spin_lock_bh(&pool->sp_lock); |
| if (likely(!list_empty(&pool->sp_sockets))) { |
| xprt = list_first_entry(&pool->sp_sockets, |
| struct svc_xprt, xpt_ready); |
| list_del_init(&xprt->xpt_ready); |
| svc_xprt_get(xprt); |
| } |
| spin_unlock_bh(&pool->sp_lock); |
| out: |
| return xprt; |
| } |
| |
| /** |
| * 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) |
| { |
| struct svc_xprt *xprt = rqstp->rq_xprt; |
| |
| space += rqstp->rq_res.head[0].iov_len; |
| |
| if (xprt && space < rqstp->rq_reserved) { |
| atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved); |
| rqstp->rq_reserved = space; |
| smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */ |
| 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; |
| |
| xprt->xpt_ops->xpo_release_rqst(rqstp); |
| |
| kfree(rqstp->rq_deferred); |
| rqstp->rq_deferred = NULL; |
| |
| pagevec_release(&rqstp->rq_pvec); |
| 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); |
| svc_xprt_release_slot(rqstp); |
| rqstp->rq_xprt = NULL; |
| svc_xprt_put(xprt); |
| } |
| |
| /* |
| * Some svc_serv's will have occasional work to do, even when a xprt is not |
| * waiting to be serviced. This function is there to "kick" a task in one of |
| * those services so that it can wake up and do that work. Note that we only |
| * bother with pool 0 as we don't need to wake up more than one thread for |
| * this purpose. |
| */ |
| void svc_wake_up(struct svc_serv *serv) |
| { |
| struct svc_rqst *rqstp; |
| struct svc_pool *pool; |
| |
| pool = &serv->sv_pools[0]; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { |
| /* skip any that aren't queued */ |
| if (test_bit(RQ_BUSY, &rqstp->rq_flags)) |
| continue; |
| rcu_read_unlock(); |
| wake_up_process(rqstp->rq_task); |
| trace_svc_wake_up(rqstp->rq_task->pid); |
| return; |
| } |
| rcu_read_unlock(); |
| |
| /* No free entries available */ |
| set_bit(SP_TASK_PENDING, &pool->sp_flags); |
| smp_wmb(); |
| trace_svc_wake_up(0); |
| } |
| 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)) { |
| /* Try to help the admin */ |
| net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n", |
| serv->sv_name, serv->sv_maxconn ? |
| "max number of connections" : |
| "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); |
| } |
| } |
| } |
| |
| static int svc_alloc_arg(struct svc_rqst *rqstp) |
| { |
| struct svc_serv *serv = rqstp->rq_server; |
| struct xdr_buf *arg = &rqstp->rq_arg; |
| unsigned long pages, filled, ret; |
| |
| pagevec_init(&rqstp->rq_pvec); |
| |
| pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT; |
| if (pages > RPCSVC_MAXPAGES) { |
| pr_warn_once("svc: warning: pages=%lu > RPCSVC_MAXPAGES=%lu\n", |
| pages, RPCSVC_MAXPAGES); |
| /* use as many pages as possible */ |
| pages = RPCSVC_MAXPAGES; |
| } |
| |
| for (filled = 0; filled < pages; filled = ret) { |
| ret = alloc_pages_bulk_array(GFP_KERNEL, pages, |
| rqstp->rq_pages); |
| if (ret > filled) |
| /* Made progress, don't sleep yet */ |
| continue; |
| |
| set_current_state(TASK_INTERRUPTIBLE); |
| if (signalled() || kthread_should_stop()) { |
| set_current_state(TASK_RUNNING); |
| return -EINTR; |
| } |
| trace_svc_alloc_arg_err(pages, ret); |
| memalloc_retry_wait(GFP_KERNEL); |
| } |
| rqstp->rq_page_end = &rqstp->rq_pages[pages]; |
| rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */ |
| |
| /* Make arg->head point to first page and arg->pages point to rest */ |
| 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; |
| return 0; |
| } |
| |
| static bool |
| rqst_should_sleep(struct svc_rqst *rqstp) |
| { |
| struct svc_pool *pool = rqstp->rq_pool; |
| |
| /* did someone call svc_wake_up? */ |
| if (test_and_clear_bit(SP_TASK_PENDING, &pool->sp_flags)) |
| return false; |
| |
| /* was a socket queued? */ |
| if (!list_empty(&pool->sp_sockets)) |
| return false; |
| |
| /* are we shutting down? */ |
| if (signalled() || kthread_should_stop()) |
| return false; |
| |
| /* are we freezing? */ |
| if (freezing(current)) |
| return false; |
| |
| return true; |
| } |
| |
| static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) |
| { |
| struct svc_pool *pool = rqstp->rq_pool; |
| long time_left = 0; |
| |
| /* rq_xprt should be clear on entry */ |
| WARN_ON_ONCE(rqstp->rq_xprt); |
| |
| rqstp->rq_xprt = svc_xprt_dequeue(pool); |
| if (rqstp->rq_xprt) |
| goto out_found; |
| |
| /* |
| * We have to be able to interrupt this wait |
| * to bring down the daemons ... |
| */ |
| set_current_state(TASK_INTERRUPTIBLE); |
| smp_mb__before_atomic(); |
| clear_bit(SP_CONGESTED, &pool->sp_flags); |
| clear_bit(RQ_BUSY, &rqstp->rq_flags); |
| smp_mb__after_atomic(); |
| |
| if (likely(rqst_should_sleep(rqstp))) |
| time_left = schedule_timeout(timeout); |
| else |
| __set_current_state(TASK_RUNNING); |
| |
| try_to_freeze(); |
| |
| set_bit(RQ_BUSY, &rqstp->rq_flags); |
| smp_mb__after_atomic(); |
| rqstp->rq_xprt = svc_xprt_dequeue(pool); |
| if (rqstp->rq_xprt) |
| goto out_found; |
| |
| if (!time_left) |
| percpu_counter_inc(&pool->sp_threads_timedout); |
| |
| if (signalled() || kthread_should_stop()) |
| return ERR_PTR(-EINTR); |
| return ERR_PTR(-EAGAIN); |
| out_found: |
| /* Normally we will wait up to 5 seconds for any required |
| * cache information to be provided. |
| */ |
| if (!test_bit(SP_CONGESTED, &pool->sp_flags)) |
| rqstp->rq_chandle.thread_wait = 5*HZ; |
| else |
| rqstp->rq_chandle.thread_wait = 1*HZ; |
| trace_svc_xprt_dequeue(rqstp); |
| return rqstp->rq_xprt; |
| } |
| |
| static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt) |
| { |
| 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 */ |
| serv->sv_temptimer.function = svc_age_temp_xprts; |
| mod_timer(&serv->sv_temptimer, |
| jiffies + svc_conn_age_period * HZ); |
| } |
| spin_unlock_bh(&serv->sv_lock); |
| svc_xprt_received(newxpt); |
| } |
| |
| static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) |
| { |
| struct svc_serv *serv = rqstp->rq_server; |
| int len = 0; |
| |
| if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { |
| if (test_and_clear_bit(XPT_KILL_TEMP, &xprt->xpt_flags)) |
| xprt->xpt_ops->xpo_kill_temp_xprt(xprt); |
| 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; |
| /* |
| * We know this module_get will succeed because the |
| * listener holds a reference too |
| */ |
| __module_get(xprt->xpt_class->xcl_owner); |
| svc_check_conn_limits(xprt->xpt_server); |
| newxpt = xprt->xpt_ops->xpo_accept(xprt); |
| if (newxpt) { |
| newxpt->xpt_cred = get_cred(xprt->xpt_cred); |
| svc_add_new_temp_xprt(serv, newxpt); |
| trace_svc_xprt_accept(newxpt, serv->sv_name); |
| } else { |
| module_put(xprt->xpt_class->xcl_owner); |
| } |
| svc_xprt_received(xprt); |
| } else if (svc_xprt_reserve_slot(rqstp, xprt)) { |
| /* XPT_DATA|XPT_DEFERRED case: */ |
| dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", |
| rqstp, rqstp->rq_pool->sp_id, xprt, |
| kref_read(&xprt->xpt_ref)); |
| rqstp->rq_deferred = svc_deferred_dequeue(xprt); |
| if (rqstp->rq_deferred) |
| len = svc_deferred_recv(rqstp); |
| else |
| len = xprt->xpt_ops->xpo_recvfrom(rqstp); |
| rqstp->rq_stime = ktime_get(); |
| rqstp->rq_reserved = serv->sv_max_mesg; |
| atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); |
| } else |
| svc_xprt_received(xprt); |
| |
| out: |
| return len; |
| } |
| |
| /* |
| * 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; |
| int len, err; |
| |
| err = svc_alloc_arg(rqstp); |
| if (err) |
| goto out; |
| |
| try_to_freeze(); |
| cond_resched(); |
| err = -EINTR; |
| if (signalled() || kthread_should_stop()) |
| goto out; |
| |
| xprt = svc_get_next_xprt(rqstp, timeout); |
| if (IS_ERR(xprt)) { |
| err = PTR_ERR(xprt); |
| goto out; |
| } |
| |
| len = svc_handle_xprt(rqstp, xprt); |
| |
| /* No data, incomplete (TCP) read, or accept() */ |
| err = -EAGAIN; |
| if (len <= 0) |
| goto out_release; |
| trace_svc_xdr_recvfrom(&rqstp->rq_arg); |
| |
| clear_bit(XPT_OLD, &xprt->xpt_flags); |
| |
| rqstp->rq_chandle.defer = svc_defer; |
| |
| if (serv->sv_stats) |
| serv->sv_stats->netcnt++; |
| return len; |
| out_release: |
| rqstp->rq_res.len = 0; |
| svc_xprt_release(rqstp); |
| out: |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(svc_recv); |
| |
| /* |
| * Drop request |
| */ |
| void svc_drop(struct svc_rqst *rqstp) |
| { |
| trace_svc_drop(rqstp); |
| 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 = -EFAULT; |
| struct xdr_buf *xb; |
| |
| xprt = rqstp->rq_xprt; |
| if (!xprt) |
| goto out; |
| |
| /* calculate over-all length */ |
| xb = &rqstp->rq_res; |
| xb->len = xb->head[0].iov_len + |
| xb->page_len + |
| xb->tail[0].iov_len; |
| trace_svc_xdr_sendto(rqstp->rq_xid, xb); |
| trace_svc_stats_latency(rqstp); |
| |
| len = xprt->xpt_ops->xpo_sendto(rqstp); |
| |
| trace_svc_send(rqstp, len); |
| svc_xprt_release(rqstp); |
| |
| if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN) |
| len = 0; |
| out: |
| return len; |
| } |
| |
| /* |
| * Timer function to close old temporary transports, using |
| * a mark-and-sweep algorithm. |
| */ |
| static void svc_age_temp_xprts(struct timer_list *t) |
| { |
| struct svc_serv *serv = from_timer(serv, t, sv_temptimer); |
| struct svc_xprt *xprt; |
| struct list_head *le, *next; |
| |
| 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 (kref_read(&xprt->xpt_ref) > 1 || |
| test_bit(XPT_BUSY, &xprt->xpt_flags)) |
| continue; |
| list_del_init(le); |
| set_bit(XPT_CLOSE, &xprt->xpt_flags); |
| dprintk("queuing xprt %p for closing\n", xprt); |
| |
| /* a thread will dequeue and close it soon */ |
| svc_xprt_enqueue(xprt); |
| } |
| spin_unlock_bh(&serv->sv_lock); |
| |
| mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); |
| } |
| |
| /* Close temporary transports whose xpt_local matches server_addr immediately |
| * instead of waiting for them to be picked up by the timer. |
| * |
| * This is meant to be called from a notifier_block that runs when an ip |
| * address is deleted. |
| */ |
| void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr) |
| { |
| struct svc_xprt *xprt; |
| struct list_head *le, *next; |
| LIST_HEAD(to_be_closed); |
| |
| spin_lock_bh(&serv->sv_lock); |
| list_for_each_safe(le, next, &serv->sv_tempsocks) { |
| xprt = list_entry(le, struct svc_xprt, xpt_list); |
| if (rpc_cmp_addr(server_addr, (struct sockaddr *) |
| &xprt->xpt_local)) { |
| dprintk("svc_age_temp_xprts_now: found %p\n", xprt); |
| list_move(le, &to_be_closed); |
| } |
| } |
| spin_unlock_bh(&serv->sv_lock); |
| |
| while (!list_empty(&to_be_closed)) { |
| le = to_be_closed.next; |
| list_del_init(le); |
| xprt = list_entry(le, struct svc_xprt, xpt_list); |
| set_bit(XPT_CLOSE, &xprt->xpt_flags); |
| set_bit(XPT_KILL_TEMP, &xprt->xpt_flags); |
| dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n", |
| xprt); |
| svc_xprt_enqueue(xprt); |
| } |
| } |
| EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now); |
| |
| 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_init(&u->list); |
| u->callback(u); |
| } |
| spin_unlock(&xprt->xpt_lock); |
| } |
| |
| /* |
| * Remove a dead transport |
| */ |
| static void svc_delete_xprt(struct svc_xprt *xprt) |
| { |
| struct svc_serv *serv = xprt->xpt_server; |
| struct svc_deferred_req *dr; |
| |
| if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) |
| return; |
| |
| trace_svc_xprt_detach(xprt); |
| xprt->xpt_ops->xpo_detach(xprt); |
| if (xprt->xpt_bc_xprt) |
| xprt->xpt_bc_xprt->ops->close(xprt->xpt_bc_xprt); |
| |
| spin_lock_bh(&serv->sv_lock); |
| list_del_init(&xprt->xpt_list); |
| WARN_ON_ONCE(!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); |
| } |
| |
| /** |
| * svc_xprt_close - Close a client connection |
| * @xprt: transport to disconnect |
| * |
| */ |
| void svc_xprt_close(struct svc_xprt *xprt) |
| { |
| trace_svc_xprt_close(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_xprt_close); |
| |
| static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net) |
| { |
| struct svc_xprt *xprt; |
| int ret = 0; |
| |
| spin_lock_bh(&serv->sv_lock); |
| list_for_each_entry(xprt, xprt_list, xpt_list) { |
| if (xprt->xpt_net != net) |
| continue; |
| ret++; |
| set_bit(XPT_CLOSE, &xprt->xpt_flags); |
| svc_xprt_enqueue(xprt); |
| } |
| spin_unlock_bh(&serv->sv_lock); |
| return ret; |
| } |
| |
| static struct svc_xprt *svc_dequeue_net(struct svc_serv *serv, struct net *net) |
| { |
| struct svc_pool *pool; |
| struct svc_xprt *xprt; |
| struct svc_xprt *tmp; |
| int i; |
| |
| for (i = 0; i < serv->sv_nrpools; i++) { |
| pool = &serv->sv_pools[i]; |
| |
| spin_lock_bh(&pool->sp_lock); |
| list_for_each_entry_safe(xprt, tmp, &pool->sp_sockets, xpt_ready) { |
| if (xprt->xpt_net != net) |
| continue; |
| list_del_init(&xprt->xpt_ready); |
| spin_unlock_bh(&pool->sp_lock); |
| return xprt; |
| } |
| spin_unlock_bh(&pool->sp_lock); |
| } |
| return NULL; |
| } |
| |
| static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net) |
| { |
| struct svc_xprt *xprt; |
| |
| while ((xprt = svc_dequeue_net(serv, net))) { |
| set_bit(XPT_CLOSE, &xprt->xpt_flags); |
| svc_delete_xprt(xprt); |
| } |
| } |
| |
| /** |
| * svc_xprt_destroy_all - Destroy transports associated with @serv |
| * @serv: RPC service to be shut down |
| * @net: target network namespace |
| * |
| * Server threads may still be running (especially in the case where the |
| * service is still running in other network namespaces). |
| * |
| * So we shut down sockets the same way we would on a running server, by |
| * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do |
| * the close. In the case there are no such other threads, |
| * threads running, svc_clean_up_xprts() does a simple version of a |
| * server's main event loop, and in the case where there are other |
| * threads, we may need to wait a little while and then check again to |
| * see if they're done. |
| */ |
| void svc_xprt_destroy_all(struct svc_serv *serv, struct net *net) |
| { |
| int delay = 0; |
| |
| while (svc_close_list(serv, &serv->sv_permsocks, net) + |
| svc_close_list(serv, &serv->sv_tempsocks, net)) { |
| |
| svc_clean_up_xprts(serv, net); |
| msleep(delay++); |
| } |
| } |
| EXPORT_SYMBOL_GPL(svc_xprt_destroy_all); |
| |
| /* |
| * 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); |
| trace_svc_defer_drop(dr); |
| svc_xprt_put(xprt); |
| kfree(dr); |
| return; |
| } |
| dr->xprt = NULL; |
| list_add(&dr->handle.recent, &xprt->xpt_deferred); |
| spin_unlock(&xprt->xpt_lock); |
| trace_svc_defer_queue(dr); |
| 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 || !test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags)) |
| 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_ctxt = rqstp->rq_xprt_ctxt; |
| rqstp->rq_xprt_ctxt = NULL; |
| |
| /* 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); |
| } |
| trace_svc_defer(rqstp); |
| svc_xprt_get(rqstp->rq_xprt); |
| dr->xprt = rqstp->rq_xprt; |
| set_bit(RQ_DROPME, &rqstp->rq_flags); |
| |
| dr->handle.revisit = svc_revisit; |
| return &dr->handle; |
| } |
| |
| /* |
| * recv data from a deferred request into an active one |
| */ |
| static noinline int svc_deferred_recv(struct svc_rqst *rqstp) |
| { |
| struct svc_deferred_req *dr = rqstp->rq_deferred; |
| |
| trace_svc_defer_recv(dr); |
| |
| /* setup iov_base past transport header */ |
| rqstp->rq_arg.head[0].iov_base = dr->args; |
| /* The iov_len does not include the transport header bytes */ |
| rqstp->rq_arg.head[0].iov_len = dr->argslen << 2; |
| 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_daddr = dr->daddr; |
| rqstp->rq_respages = rqstp->rq_pages; |
| rqstp->rq_xprt_ctxt = dr->xprt_ctxt; |
| svc_xprt_received(rqstp->rq_xprt); |
| return dr->argslen << 2; |
| } |
| |
| |
| 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 |
| * @net: owner net pointer |
| * @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, |
| struct net *net, 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 (xprt->xpt_net != net) |
| continue; |
| 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 %llu %llu %llu %llu\n", |
| pool->sp_id, |
| percpu_counter_sum_positive(&pool->sp_sockets_queued), |
| percpu_counter_sum_positive(&pool->sp_sockets_queued), |
| percpu_counter_sum_positive(&pool->sp_threads_woken), |
| percpu_counter_sum_positive(&pool->sp_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); |
| |
| /*----------------------------------------------------------------------------*/ |