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1433 lines
38 KiB
1433 lines
38 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* linux/net/sunrpc/svc_xprt.c |
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* |
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* Author: Tom Tucker <[email protected]> |
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*/ |
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|
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#include <linux/sched.h> |
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#include <linux/errno.h> |
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#include <linux/freezer.h> |
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#include <linux/kthread.h> |
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#include <linux/slab.h> |
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#include <net/sock.h> |
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#include <linux/sunrpc/addr.h> |
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#include <linux/sunrpc/stats.h> |
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#include <linux/sunrpc/svc_xprt.h> |
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#include <linux/sunrpc/svcsock.h> |
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#include <linux/sunrpc/xprt.h> |
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#include <linux/module.h> |
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#include <linux/netdevice.h> |
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#include <trace/events/sunrpc.h> |
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|
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#define RPCDBG_FACILITY RPCDBG_SVCXPRT |
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|
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static unsigned int svc_rpc_per_connection_limit __read_mostly; |
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module_param(svc_rpc_per_connection_limit, uint, 0644); |
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static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt); |
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static int svc_deferred_recv(struct svc_rqst *rqstp); |
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static struct cache_deferred_req *svc_defer(struct cache_req *req); |
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static void svc_age_temp_xprts(struct timer_list *t); |
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static void svc_delete_xprt(struct svc_xprt *xprt); |
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|
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/* apparently the "standard" is that clients close |
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* idle connections after 5 minutes, servers after |
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* 6 minutes |
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* http://nfsv4bat.org/Documents/ConnectAThon/1996/nfstcp.pdf |
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*/ |
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static int svc_conn_age_period = 6*60; |
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|
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/* List of registered transport classes */ |
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static DEFINE_SPINLOCK(svc_xprt_class_lock); |
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static LIST_HEAD(svc_xprt_class_list); |
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|
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/* SMP locking strategy: |
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* |
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* svc_pool->sp_lock protects most of the fields of that pool. |
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* svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt. |
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* when both need to be taken (rare), svc_serv->sv_lock is first. |
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* The "service mutex" protects svc_serv->sv_nrthread. |
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* svc_sock->sk_lock protects the svc_sock->sk_deferred list |
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* and the ->sk_info_authunix cache. |
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* |
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* The XPT_BUSY bit in xprt->xpt_flags prevents a transport being |
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* enqueued multiply. During normal transport processing this bit |
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* is set by svc_xprt_enqueue and cleared by svc_xprt_received. |
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* Providers should not manipulate this bit directly. |
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* |
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* Some flags can be set to certain values at any time |
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* providing that certain rules are followed: |
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* |
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* XPT_CONN, XPT_DATA: |
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* - Can be set or cleared at any time. |
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* - After a set, svc_xprt_enqueue must be called to enqueue |
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* the transport for processing. |
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* - After a clear, the transport must be read/accepted. |
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* If this succeeds, it must be set again. |
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* XPT_CLOSE: |
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* - Can set at any time. It is never cleared. |
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* XPT_DEAD: |
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* - Can only be set while XPT_BUSY is held which ensures |
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* that no other thread will be using the transport or will |
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* try to set XPT_DEAD. |
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*/ |
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int svc_reg_xprt_class(struct svc_xprt_class *xcl) |
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{ |
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struct svc_xprt_class *cl; |
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int res = -EEXIST; |
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|
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dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name); |
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|
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INIT_LIST_HEAD(&xcl->xcl_list); |
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spin_lock(&svc_xprt_class_lock); |
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/* Make sure there isn't already a class with the same name */ |
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list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) { |
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if (strcmp(xcl->xcl_name, cl->xcl_name) == 0) |
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goto out; |
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} |
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list_add_tail(&xcl->xcl_list, &svc_xprt_class_list); |
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res = 0; |
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out: |
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spin_unlock(&svc_xprt_class_lock); |
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return res; |
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} |
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EXPORT_SYMBOL_GPL(svc_reg_xprt_class); |
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|
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void svc_unreg_xprt_class(struct svc_xprt_class *xcl) |
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{ |
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dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name); |
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spin_lock(&svc_xprt_class_lock); |
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list_del_init(&xcl->xcl_list); |
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spin_unlock(&svc_xprt_class_lock); |
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} |
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EXPORT_SYMBOL_GPL(svc_unreg_xprt_class); |
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|
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/** |
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* svc_print_xprts - Format the transport list for printing |
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* @buf: target buffer for formatted address |
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* @maxlen: length of target buffer |
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* |
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* Fills in @buf with a string containing a list of transport names, each name |
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* terminated with '\n'. If the buffer is too small, some entries may be |
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* missing, but it is guaranteed that all lines in the output buffer are |
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* complete. |
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* |
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* Returns positive length of the filled-in string. |
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*/ |
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int svc_print_xprts(char *buf, int maxlen) |
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{ |
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struct svc_xprt_class *xcl; |
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char tmpstr[80]; |
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int len = 0; |
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buf[0] = '\0'; |
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|
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spin_lock(&svc_xprt_class_lock); |
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list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { |
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int slen; |
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|
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slen = snprintf(tmpstr, sizeof(tmpstr), "%s %d\n", |
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xcl->xcl_name, xcl->xcl_max_payload); |
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if (slen >= sizeof(tmpstr) || len + slen >= maxlen) |
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break; |
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len += slen; |
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strcat(buf, tmpstr); |
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} |
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spin_unlock(&svc_xprt_class_lock); |
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|
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return len; |
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} |
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|
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static void svc_xprt_free(struct kref *kref) |
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{ |
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struct svc_xprt *xprt = |
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container_of(kref, struct svc_xprt, xpt_ref); |
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struct module *owner = xprt->xpt_class->xcl_owner; |
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if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) |
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svcauth_unix_info_release(xprt); |
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put_cred(xprt->xpt_cred); |
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put_net(xprt->xpt_net); |
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/* See comment on corresponding get in xs_setup_bc_tcp(): */ |
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if (xprt->xpt_bc_xprt) |
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xprt_put(xprt->xpt_bc_xprt); |
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if (xprt->xpt_bc_xps) |
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xprt_switch_put(xprt->xpt_bc_xps); |
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trace_svc_xprt_free(xprt); |
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xprt->xpt_ops->xpo_free(xprt); |
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module_put(owner); |
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} |
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|
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void svc_xprt_put(struct svc_xprt *xprt) |
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{ |
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kref_put(&xprt->xpt_ref, svc_xprt_free); |
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} |
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EXPORT_SYMBOL_GPL(svc_xprt_put); |
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|
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/* |
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* Called by transport drivers to initialize the transport independent |
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* portion of the transport instance. |
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*/ |
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void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl, |
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struct svc_xprt *xprt, struct svc_serv *serv) |
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{ |
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memset(xprt, 0, sizeof(*xprt)); |
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xprt->xpt_class = xcl; |
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xprt->xpt_ops = xcl->xcl_ops; |
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kref_init(&xprt->xpt_ref); |
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xprt->xpt_server = serv; |
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INIT_LIST_HEAD(&xprt->xpt_list); |
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INIT_LIST_HEAD(&xprt->xpt_ready); |
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INIT_LIST_HEAD(&xprt->xpt_deferred); |
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INIT_LIST_HEAD(&xprt->xpt_users); |
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mutex_init(&xprt->xpt_mutex); |
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spin_lock_init(&xprt->xpt_lock); |
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set_bit(XPT_BUSY, &xprt->xpt_flags); |
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xprt->xpt_net = get_net(net); |
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strcpy(xprt->xpt_remotebuf, "uninitialized"); |
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} |
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EXPORT_SYMBOL_GPL(svc_xprt_init); |
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|
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static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl, |
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struct svc_serv *serv, |
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struct net *net, |
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const int family, |
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const unsigned short port, |
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int flags) |
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{ |
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struct sockaddr_in sin = { |
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.sin_family = AF_INET, |
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.sin_addr.s_addr = htonl(INADDR_ANY), |
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.sin_port = htons(port), |
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}; |
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#if IS_ENABLED(CONFIG_IPV6) |
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struct sockaddr_in6 sin6 = { |
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.sin6_family = AF_INET6, |
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.sin6_addr = IN6ADDR_ANY_INIT, |
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.sin6_port = htons(port), |
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}; |
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#endif |
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struct svc_xprt *xprt; |
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struct sockaddr *sap; |
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size_t len; |
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|
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switch (family) { |
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case PF_INET: |
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sap = (struct sockaddr *)&sin; |
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len = sizeof(sin); |
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break; |
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#if IS_ENABLED(CONFIG_IPV6) |
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case PF_INET6: |
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sap = (struct sockaddr *)&sin6; |
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len = sizeof(sin6); |
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break; |
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#endif |
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default: |
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return ERR_PTR(-EAFNOSUPPORT); |
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} |
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|
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xprt = xcl->xcl_ops->xpo_create(serv, net, sap, len, flags); |
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if (IS_ERR(xprt)) |
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trace_svc_xprt_create_err(serv->sv_program->pg_name, |
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xcl->xcl_name, sap, xprt); |
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return xprt; |
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} |
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|
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/* |
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* svc_xprt_received conditionally queues the transport for processing |
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* by another thread. The caller must hold the XPT_BUSY bit and must |
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* not thereafter touch transport data. |
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* |
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* Note: XPT_DATA only gets cleared when a read-attempt finds no (or |
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* insufficient) data. |
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*/ |
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static void svc_xprt_received(struct svc_xprt *xprt) |
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{ |
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if (!test_bit(XPT_BUSY, &xprt->xpt_flags)) { |
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WARN_ONCE(1, "xprt=0x%p already busy!", xprt); |
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return; |
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} |
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|
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/* As soon as we clear busy, the xprt could be closed and |
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* 'put', so we need a reference to call svc_enqueue_xprt with: |
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*/ |
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svc_xprt_get(xprt); |
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smp_mb__before_atomic(); |
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clear_bit(XPT_BUSY, &xprt->xpt_flags); |
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xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt); |
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svc_xprt_put(xprt); |
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} |
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void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new) |
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{ |
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clear_bit(XPT_TEMP, &new->xpt_flags); |
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spin_lock_bh(&serv->sv_lock); |
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list_add(&new->xpt_list, &serv->sv_permsocks); |
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spin_unlock_bh(&serv->sv_lock); |
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svc_xprt_received(new); |
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} |
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static int _svc_create_xprt(struct svc_serv *serv, const char *xprt_name, |
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struct net *net, const int family, |
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const unsigned short port, int flags, |
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const struct cred *cred) |
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{ |
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struct svc_xprt_class *xcl; |
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|
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spin_lock(&svc_xprt_class_lock); |
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list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { |
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struct svc_xprt *newxprt; |
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unsigned short newport; |
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|
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if (strcmp(xprt_name, xcl->xcl_name)) |
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continue; |
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|
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if (!try_module_get(xcl->xcl_owner)) |
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goto err; |
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spin_unlock(&svc_xprt_class_lock); |
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newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags); |
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if (IS_ERR(newxprt)) { |
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module_put(xcl->xcl_owner); |
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return PTR_ERR(newxprt); |
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} |
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newxprt->xpt_cred = get_cred(cred); |
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svc_add_new_perm_xprt(serv, newxprt); |
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newport = svc_xprt_local_port(newxprt); |
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return newport; |
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} |
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err: |
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spin_unlock(&svc_xprt_class_lock); |
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/* This errno is exposed to user space. Provide a reasonable |
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* perror msg for a bad transport. */ |
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return -EPROTONOSUPPORT; |
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} |
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|
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int svc_create_xprt(struct svc_serv *serv, const char *xprt_name, |
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struct net *net, const int family, |
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const unsigned short port, int flags, |
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const struct cred *cred) |
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{ |
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int err; |
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|
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err = _svc_create_xprt(serv, xprt_name, net, family, port, flags, cred); |
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if (err == -EPROTONOSUPPORT) { |
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request_module("svc%s", xprt_name); |
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err = _svc_create_xprt(serv, xprt_name, net, family, port, flags, cred); |
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} |
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return err; |
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} |
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EXPORT_SYMBOL_GPL(svc_create_xprt); |
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|
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/* |
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* Copy the local and remote xprt addresses to the rqstp structure |
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*/ |
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void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) |
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{ |
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memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); |
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rqstp->rq_addrlen = xprt->xpt_remotelen; |
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|
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/* |
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* Destination address in request is needed for binding the |
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* source address in RPC replies/callbacks later. |
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*/ |
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memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen); |
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rqstp->rq_daddrlen = xprt->xpt_locallen; |
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} |
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EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); |
|
|
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/** |
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* svc_print_addr - Format rq_addr field for printing |
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* @rqstp: svc_rqst struct containing address to print |
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* @buf: target buffer for formatted address |
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* @len: length of target buffer |
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* |
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*/ |
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char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) |
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{ |
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return __svc_print_addr(svc_addr(rqstp), buf, len); |
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} |
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EXPORT_SYMBOL_GPL(svc_print_addr); |
|
|
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static bool svc_xprt_slots_in_range(struct svc_xprt *xprt) |
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{ |
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unsigned int limit = svc_rpc_per_connection_limit; |
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int nrqsts = atomic_read(&xprt->xpt_nr_rqsts); |
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|
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return limit == 0 || (nrqsts >= 0 && nrqsts < limit); |
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} |
|
|
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static bool svc_xprt_reserve_slot(struct svc_rqst *rqstp, struct svc_xprt *xprt) |
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{ |
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if (!test_bit(RQ_DATA, &rqstp->rq_flags)) { |
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if (!svc_xprt_slots_in_range(xprt)) |
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return false; |
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atomic_inc(&xprt->xpt_nr_rqsts); |
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set_bit(RQ_DATA, &rqstp->rq_flags); |
|
} |
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return true; |
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} |
|
|
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static void svc_xprt_release_slot(struct svc_rqst *rqstp) |
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{ |
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struct svc_xprt *xprt = rqstp->rq_xprt; |
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if (test_and_clear_bit(RQ_DATA, &rqstp->rq_flags)) { |
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atomic_dec(&xprt->xpt_nr_rqsts); |
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smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */ |
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svc_xprt_enqueue(xprt); |
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} |
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} |
|
|
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static bool svc_xprt_ready(struct svc_xprt *xprt) |
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{ |
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unsigned long xpt_flags; |
|
|
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/* |
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* If another cpu has recently updated xpt_flags, |
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* sk_sock->flags, xpt_reserved, or xpt_nr_rqsts, we need to |
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* know about it; otherwise it's possible that both that cpu and |
|
* this one could call svc_xprt_enqueue() without either |
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* svc_xprt_enqueue() recognizing that the conditions below |
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* are satisfied, and we could stall indefinitely: |
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*/ |
|
smp_rmb(); |
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xpt_flags = READ_ONCE(xprt->xpt_flags); |
|
|
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if (xpt_flags & (BIT(XPT_CONN) | BIT(XPT_CLOSE))) |
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return true; |
|
if (xpt_flags & (BIT(XPT_DATA) | BIT(XPT_DEFERRED))) { |
|
if (xprt->xpt_ops->xpo_has_wspace(xprt) && |
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svc_xprt_slots_in_range(xprt)) |
|
return true; |
|
trace_svc_xprt_no_write_space(xprt); |
|
return false; |
|
} |
|
return false; |
|
} |
|
|
|
void svc_xprt_do_enqueue(struct svc_xprt *xprt) |
|
{ |
|
struct svc_pool *pool; |
|
struct svc_rqst *rqstp = NULL; |
|
int cpu; |
|
|
|
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; |
|
|
|
cpu = get_cpu(); |
|
pool = svc_pool_for_cpu(xprt->xpt_server, cpu); |
|
|
|
atomic_long_inc(&pool->sp_stats.packets); |
|
|
|
spin_lock_bh(&pool->sp_lock); |
|
list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); |
|
pool->sp_stats.sockets_queued++; |
|
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; |
|
atomic_long_inc(&pool->sp_stats.threads_woken); |
|
rqstp->rq_qtime = ktime_get(); |
|
wake_up_process(rqstp->rq_task); |
|
goto out_unlock; |
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} |
|
set_bit(SP_CONGESTED, &pool->sp_flags); |
|
rqstp = NULL; |
|
out_unlock: |
|
rcu_read_unlock(); |
|
put_cpu(); |
|
trace_svc_xprt_do_enqueue(xprt, rqstp); |
|
} |
|
EXPORT_SYMBOL_GPL(svc_xprt_do_enqueue); |
|
|
|
/* |
|
* Queue up a transport with data pending. If there are idle nfsd |
|
* processes, wake 'em up. |
|
* |
|
*/ |
|
void svc_xprt_enqueue(struct svc_xprt *xprt) |
|
{ |
|
if (test_bit(XPT_BUSY, &xprt->xpt_flags)) |
|
return; |
|
xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt); |
|
} |
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EXPORT_SYMBOL_GPL(svc_xprt_enqueue); |
|
|
|
/* |
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* Dequeue the first transport, if there is one. |
|
*/ |
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static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) |
|
{ |
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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; |
|
|
|
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; |
|
int pages; |
|
int i; |
|
|
|
/* now allocate needed pages. If we get a failure, sleep briefly */ |
|
pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT; |
|
if (pages > RPCSVC_MAXPAGES) { |
|
pr_warn_once("svc: warning: pages=%u > RPCSVC_MAXPAGES=%lu\n", |
|
pages, RPCSVC_MAXPAGES); |
|
/* use as many pages as possible */ |
|
pages = RPCSVC_MAXPAGES; |
|
} |
|
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_page_end = &rqstp->rq_pages[i]; |
|
rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */ |
|
|
|
/* 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; |
|
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) |
|
atomic_long_inc(&pool->sp_stats.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); |
|
} 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); |
|
} |
|
/* clear XPT_BUSY: */ |
|
svc_xprt_received(xprt); |
|
out: |
|
trace_svc_handle_xprt(xprt, len); |
|
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); |
|
|
|
xprt->xpt_ops->xpo_secure_port(rqstp); |
|
rqstp->rq_chandle.defer = svc_defer; |
|
rqstp->rq_xid = svc_getu32(&rqstp->rq_arg.head[0]); |
|
|
|
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); |
|
} |
|
|
|
void svc_close_xprt(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_close_xprt); |
|
|
|
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); |
|
} |
|
} |
|
|
|
/* |
|
* 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_close_net(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++); |
|
} |
|
} |
|
|
|
/* |
|
* 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_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); |
|
} |
|
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 + (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 |
|
* @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 %lu %lu %lu %lu\n", |
|
pool->sp_id, |
|
(unsigned long)atomic_long_read(&pool->sp_stats.packets), |
|
pool->sp_stats.sockets_queued, |
|
(unsigned long)atomic_long_read(&pool->sp_stats.threads_woken), |
|
(unsigned long)atomic_long_read(&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); |
|
|
|
/*----------------------------------------------------------------------------*/
|
|
|