Tom Tucker | 1d8206b9 | 2007-12-30 21:07:15 -0600 | [diff] [blame] | 1 | /* |
| 2 | * linux/net/sunrpc/svc_xprt.c |
| 3 | * |
| 4 | * Author: Tom Tucker <tom@opengridcomputing.com> |
| 5 | */ |
| 6 | |
| 7 | #include <linux/sched.h> |
| 8 | #include <linux/errno.h> |
Tom Tucker | 1d8206b9 | 2007-12-30 21:07:15 -0600 | [diff] [blame] | 9 | #include <linux/freezer.h> |
Jeff Layton | 7086721 | 2008-02-07 16:34:54 -0500 | [diff] [blame] | 10 | #include <linux/kthread.h> |
Tom Tucker | 1d8206b9 | 2007-12-30 21:07:15 -0600 | [diff] [blame] | 11 | #include <net/sock.h> |
Tom Tucker | 1d8206b9 | 2007-12-30 21:07:15 -0600 | [diff] [blame] | 12 | #include <linux/sunrpc/stats.h> |
| 13 | #include <linux/sunrpc/svc_xprt.h> |
| 14 | |
| 15 | #define RPCDBG_FACILITY RPCDBG_SVCXPRT |
| 16 | |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 17 | static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt); |
| 18 | static int svc_deferred_recv(struct svc_rqst *rqstp); |
| 19 | static struct cache_deferred_req *svc_defer(struct cache_req *req); |
| 20 | static void svc_age_temp_xprts(unsigned long closure); |
| 21 | |
| 22 | /* apparently the "standard" is that clients close |
| 23 | * idle connections after 5 minutes, servers after |
| 24 | * 6 minutes |
| 25 | * http://www.connectathon.org/talks96/nfstcp.pdf |
| 26 | */ |
| 27 | static int svc_conn_age_period = 6*60; |
| 28 | |
Tom Tucker | 1d8206b9 | 2007-12-30 21:07:15 -0600 | [diff] [blame] | 29 | /* List of registered transport classes */ |
| 30 | static DEFINE_SPINLOCK(svc_xprt_class_lock); |
| 31 | static LIST_HEAD(svc_xprt_class_list); |
| 32 | |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 33 | /* SMP locking strategy: |
| 34 | * |
| 35 | * svc_pool->sp_lock protects most of the fields of that pool. |
| 36 | * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt. |
| 37 | * when both need to be taken (rare), svc_serv->sv_lock is first. |
| 38 | * BKL protects svc_serv->sv_nrthread. |
| 39 | * svc_sock->sk_lock protects the svc_sock->sk_deferred list |
| 40 | * and the ->sk_info_authunix cache. |
| 41 | * |
| 42 | * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being |
| 43 | * enqueued multiply. During normal transport processing this bit |
| 44 | * is set by svc_xprt_enqueue and cleared by svc_xprt_received. |
| 45 | * Providers should not manipulate this bit directly. |
| 46 | * |
| 47 | * Some flags can be set to certain values at any time |
| 48 | * providing that certain rules are followed: |
| 49 | * |
| 50 | * XPT_CONN, XPT_DATA: |
| 51 | * - Can be set or cleared at any time. |
| 52 | * - After a set, svc_xprt_enqueue must be called to enqueue |
| 53 | * the transport for processing. |
| 54 | * - After a clear, the transport must be read/accepted. |
| 55 | * If this succeeds, it must be set again. |
| 56 | * XPT_CLOSE: |
| 57 | * - Can set at any time. It is never cleared. |
| 58 | * XPT_DEAD: |
| 59 | * - Can only be set while XPT_BUSY is held which ensures |
| 60 | * that no other thread will be using the transport or will |
| 61 | * try to set XPT_DEAD. |
| 62 | */ |
| 63 | |
Tom Tucker | 1d8206b9 | 2007-12-30 21:07:15 -0600 | [diff] [blame] | 64 | int svc_reg_xprt_class(struct svc_xprt_class *xcl) |
| 65 | { |
| 66 | struct svc_xprt_class *cl; |
| 67 | int res = -EEXIST; |
| 68 | |
| 69 | dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name); |
| 70 | |
| 71 | INIT_LIST_HEAD(&xcl->xcl_list); |
| 72 | spin_lock(&svc_xprt_class_lock); |
| 73 | /* Make sure there isn't already a class with the same name */ |
| 74 | list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) { |
| 75 | if (strcmp(xcl->xcl_name, cl->xcl_name) == 0) |
| 76 | goto out; |
| 77 | } |
| 78 | list_add_tail(&xcl->xcl_list, &svc_xprt_class_list); |
| 79 | res = 0; |
| 80 | out: |
| 81 | spin_unlock(&svc_xprt_class_lock); |
| 82 | return res; |
| 83 | } |
| 84 | EXPORT_SYMBOL_GPL(svc_reg_xprt_class); |
| 85 | |
| 86 | void svc_unreg_xprt_class(struct svc_xprt_class *xcl) |
| 87 | { |
| 88 | dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name); |
| 89 | spin_lock(&svc_xprt_class_lock); |
| 90 | list_del_init(&xcl->xcl_list); |
| 91 | spin_unlock(&svc_xprt_class_lock); |
| 92 | } |
| 93 | EXPORT_SYMBOL_GPL(svc_unreg_xprt_class); |
| 94 | |
Tom Tucker | dc9a16e | 2007-12-30 21:08:31 -0600 | [diff] [blame] | 95 | /* |
| 96 | * Format the transport list for printing |
| 97 | */ |
| 98 | int svc_print_xprts(char *buf, int maxlen) |
| 99 | { |
| 100 | struct list_head *le; |
| 101 | char tmpstr[80]; |
| 102 | int len = 0; |
| 103 | buf[0] = '\0'; |
| 104 | |
| 105 | spin_lock(&svc_xprt_class_lock); |
| 106 | list_for_each(le, &svc_xprt_class_list) { |
| 107 | int slen; |
| 108 | struct svc_xprt_class *xcl = |
| 109 | list_entry(le, struct svc_xprt_class, xcl_list); |
| 110 | |
| 111 | sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload); |
| 112 | slen = strlen(tmpstr); |
| 113 | if (len + slen > maxlen) |
| 114 | break; |
| 115 | len += slen; |
| 116 | strcat(buf, tmpstr); |
| 117 | } |
| 118 | spin_unlock(&svc_xprt_class_lock); |
| 119 | |
| 120 | return len; |
| 121 | } |
| 122 | |
Tom Tucker | e1b3157 | 2007-12-30 21:07:46 -0600 | [diff] [blame] | 123 | static void svc_xprt_free(struct kref *kref) |
| 124 | { |
| 125 | struct svc_xprt *xprt = |
| 126 | container_of(kref, struct svc_xprt, xpt_ref); |
| 127 | struct module *owner = xprt->xpt_class->xcl_owner; |
Tom Tucker | def13d7 | 2007-12-30 21:08:08 -0600 | [diff] [blame] | 128 | if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags) |
| 129 | && xprt->xpt_auth_cache != NULL) |
| 130 | svcauth_unix_info_release(xprt->xpt_auth_cache); |
Tom Tucker | e1b3157 | 2007-12-30 21:07:46 -0600 | [diff] [blame] | 131 | xprt->xpt_ops->xpo_free(xprt); |
| 132 | module_put(owner); |
| 133 | } |
| 134 | |
| 135 | void svc_xprt_put(struct svc_xprt *xprt) |
| 136 | { |
| 137 | kref_put(&xprt->xpt_ref, svc_xprt_free); |
| 138 | } |
| 139 | EXPORT_SYMBOL_GPL(svc_xprt_put); |
| 140 | |
Tom Tucker | 1d8206b9 | 2007-12-30 21:07:15 -0600 | [diff] [blame] | 141 | /* |
| 142 | * Called by transport drivers to initialize the transport independent |
| 143 | * portion of the transport instance. |
| 144 | */ |
Tom Tucker | bb5cf16 | 2007-12-30 21:07:50 -0600 | [diff] [blame] | 145 | void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt, |
| 146 | struct svc_serv *serv) |
Tom Tucker | 1d8206b9 | 2007-12-30 21:07:15 -0600 | [diff] [blame] | 147 | { |
| 148 | memset(xprt, 0, sizeof(*xprt)); |
| 149 | xprt->xpt_class = xcl; |
| 150 | xprt->xpt_ops = xcl->xcl_ops; |
Tom Tucker | e1b3157 | 2007-12-30 21:07:46 -0600 | [diff] [blame] | 151 | kref_init(&xprt->xpt_ref); |
Tom Tucker | bb5cf16 | 2007-12-30 21:07:50 -0600 | [diff] [blame] | 152 | xprt->xpt_server = serv; |
Tom Tucker | 7a18208 | 2007-12-30 21:07:53 -0600 | [diff] [blame] | 153 | INIT_LIST_HEAD(&xprt->xpt_list); |
| 154 | INIT_LIST_HEAD(&xprt->xpt_ready); |
Tom Tucker | 8c7b017 | 2007-12-30 21:08:10 -0600 | [diff] [blame] | 155 | INIT_LIST_HEAD(&xprt->xpt_deferred); |
Tom Tucker | a50fea2 | 2007-12-30 21:07:59 -0600 | [diff] [blame] | 156 | mutex_init(&xprt->xpt_mutex); |
Tom Tucker | def13d7 | 2007-12-30 21:08:08 -0600 | [diff] [blame] | 157 | spin_lock_init(&xprt->xpt_lock); |
Tom Tucker | 4e5caaa | 2007-12-30 21:08:20 -0600 | [diff] [blame] | 158 | set_bit(XPT_BUSY, &xprt->xpt_flags); |
Tom Tucker | 1d8206b9 | 2007-12-30 21:07:15 -0600 | [diff] [blame] | 159 | } |
| 160 | EXPORT_SYMBOL_GPL(svc_xprt_init); |
Tom Tucker | b700cbb | 2007-12-30 21:07:42 -0600 | [diff] [blame] | 161 | |
Chuck Lever | 5dd248f | 2008-06-30 18:45:37 -0400 | [diff] [blame] | 162 | static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl, |
| 163 | struct svc_serv *serv, |
| 164 | unsigned short port, int flags) |
Tom Tucker | b700cbb | 2007-12-30 21:07:42 -0600 | [diff] [blame] | 165 | { |
Tom Tucker | b700cbb | 2007-12-30 21:07:42 -0600 | [diff] [blame] | 166 | struct sockaddr_in sin = { |
| 167 | .sin_family = AF_INET, |
Al Viro | e6f1ceb | 2008-03-17 22:44:53 -0700 | [diff] [blame] | 168 | .sin_addr.s_addr = htonl(INADDR_ANY), |
Tom Tucker | b700cbb | 2007-12-30 21:07:42 -0600 | [diff] [blame] | 169 | .sin_port = htons(port), |
| 170 | }; |
Chuck Lever | 5dd248f | 2008-06-30 18:45:37 -0400 | [diff] [blame] | 171 | struct sockaddr_in6 sin6 = { |
| 172 | .sin6_family = AF_INET6, |
| 173 | .sin6_addr = IN6ADDR_ANY_INIT, |
| 174 | .sin6_port = htons(port), |
| 175 | }; |
| 176 | struct sockaddr *sap; |
| 177 | size_t len; |
| 178 | |
| 179 | switch (serv->sv_family) { |
| 180 | case AF_INET: |
| 181 | sap = (struct sockaddr *)&sin; |
| 182 | len = sizeof(sin); |
| 183 | break; |
| 184 | case AF_INET6: |
| 185 | sap = (struct sockaddr *)&sin6; |
| 186 | len = sizeof(sin6); |
| 187 | break; |
| 188 | default: |
| 189 | return ERR_PTR(-EAFNOSUPPORT); |
| 190 | } |
| 191 | |
| 192 | return xcl->xcl_ops->xpo_create(serv, sap, len, flags); |
| 193 | } |
| 194 | |
| 195 | int svc_create_xprt(struct svc_serv *serv, char *xprt_name, unsigned short port, |
| 196 | int flags) |
| 197 | { |
| 198 | struct svc_xprt_class *xcl; |
| 199 | |
Tom Tucker | b700cbb | 2007-12-30 21:07:42 -0600 | [diff] [blame] | 200 | dprintk("svc: creating transport %s[%d]\n", xprt_name, port); |
| 201 | spin_lock(&svc_xprt_class_lock); |
| 202 | list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { |
Tom Tucker | 4e5caaa | 2007-12-30 21:08:20 -0600 | [diff] [blame] | 203 | struct svc_xprt *newxprt; |
| 204 | |
| 205 | if (strcmp(xprt_name, xcl->xcl_name)) |
| 206 | continue; |
| 207 | |
| 208 | if (!try_module_get(xcl->xcl_owner)) |
| 209 | goto err; |
| 210 | |
| 211 | spin_unlock(&svc_xprt_class_lock); |
Chuck Lever | 5dd248f | 2008-06-30 18:45:37 -0400 | [diff] [blame] | 212 | newxprt = __svc_xpo_create(xcl, serv, port, flags); |
Tom Tucker | 4e5caaa | 2007-12-30 21:08:20 -0600 | [diff] [blame] | 213 | if (IS_ERR(newxprt)) { |
| 214 | module_put(xcl->xcl_owner); |
| 215 | return PTR_ERR(newxprt); |
Tom Tucker | b700cbb | 2007-12-30 21:07:42 -0600 | [diff] [blame] | 216 | } |
Tom Tucker | 4e5caaa | 2007-12-30 21:08:20 -0600 | [diff] [blame] | 217 | |
| 218 | clear_bit(XPT_TEMP, &newxprt->xpt_flags); |
| 219 | spin_lock_bh(&serv->sv_lock); |
| 220 | list_add(&newxprt->xpt_list, &serv->sv_permsocks); |
| 221 | spin_unlock_bh(&serv->sv_lock); |
| 222 | clear_bit(XPT_BUSY, &newxprt->xpt_flags); |
| 223 | return svc_xprt_local_port(newxprt); |
Tom Tucker | b700cbb | 2007-12-30 21:07:42 -0600 | [diff] [blame] | 224 | } |
Tom Tucker | 4e5caaa | 2007-12-30 21:08:20 -0600 | [diff] [blame] | 225 | err: |
Tom Tucker | b700cbb | 2007-12-30 21:07:42 -0600 | [diff] [blame] | 226 | spin_unlock(&svc_xprt_class_lock); |
| 227 | dprintk("svc: transport %s not found\n", xprt_name); |
Tom Tucker | 4e5caaa | 2007-12-30 21:08:20 -0600 | [diff] [blame] | 228 | return -ENOENT; |
Tom Tucker | b700cbb | 2007-12-30 21:07:42 -0600 | [diff] [blame] | 229 | } |
| 230 | EXPORT_SYMBOL_GPL(svc_create_xprt); |
Tom Tucker | 9dbc240 | 2007-12-30 21:08:12 -0600 | [diff] [blame] | 231 | |
| 232 | /* |
| 233 | * Copy the local and remote xprt addresses to the rqstp structure |
| 234 | */ |
| 235 | void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) |
| 236 | { |
| 237 | struct sockaddr *sin; |
| 238 | |
| 239 | memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); |
| 240 | rqstp->rq_addrlen = xprt->xpt_remotelen; |
| 241 | |
| 242 | /* |
| 243 | * Destination address in request is needed for binding the |
| 244 | * source address in RPC replies/callbacks later. |
| 245 | */ |
| 246 | sin = (struct sockaddr *)&xprt->xpt_local; |
| 247 | switch (sin->sa_family) { |
| 248 | case AF_INET: |
| 249 | rqstp->rq_daddr.addr = ((struct sockaddr_in *)sin)->sin_addr; |
| 250 | break; |
| 251 | case AF_INET6: |
| 252 | rqstp->rq_daddr.addr6 = ((struct sockaddr_in6 *)sin)->sin6_addr; |
| 253 | break; |
| 254 | } |
| 255 | } |
| 256 | EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); |
| 257 | |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 258 | /** |
| 259 | * svc_print_addr - Format rq_addr field for printing |
| 260 | * @rqstp: svc_rqst struct containing address to print |
| 261 | * @buf: target buffer for formatted address |
| 262 | * @len: length of target buffer |
| 263 | * |
| 264 | */ |
| 265 | char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) |
| 266 | { |
| 267 | return __svc_print_addr(svc_addr(rqstp), buf, len); |
| 268 | } |
| 269 | EXPORT_SYMBOL_GPL(svc_print_addr); |
| 270 | |
| 271 | /* |
| 272 | * Queue up an idle server thread. Must have pool->sp_lock held. |
| 273 | * Note: this is really a stack rather than a queue, so that we only |
| 274 | * use as many different threads as we need, and the rest don't pollute |
| 275 | * the cache. |
| 276 | */ |
| 277 | static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp) |
| 278 | { |
| 279 | list_add(&rqstp->rq_list, &pool->sp_threads); |
| 280 | } |
| 281 | |
| 282 | /* |
| 283 | * Dequeue an nfsd thread. Must have pool->sp_lock held. |
| 284 | */ |
| 285 | static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp) |
| 286 | { |
| 287 | list_del(&rqstp->rq_list); |
| 288 | } |
| 289 | |
| 290 | /* |
| 291 | * Queue up a transport with data pending. If there are idle nfsd |
| 292 | * processes, wake 'em up. |
| 293 | * |
| 294 | */ |
| 295 | void svc_xprt_enqueue(struct svc_xprt *xprt) |
| 296 | { |
| 297 | struct svc_serv *serv = xprt->xpt_server; |
| 298 | struct svc_pool *pool; |
| 299 | struct svc_rqst *rqstp; |
| 300 | int cpu; |
| 301 | |
| 302 | if (!(xprt->xpt_flags & |
| 303 | ((1<<XPT_CONN)|(1<<XPT_DATA)|(1<<XPT_CLOSE)|(1<<XPT_DEFERRED)))) |
| 304 | return; |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 305 | |
| 306 | cpu = get_cpu(); |
| 307 | pool = svc_pool_for_cpu(xprt->xpt_server, cpu); |
| 308 | put_cpu(); |
| 309 | |
| 310 | spin_lock_bh(&pool->sp_lock); |
| 311 | |
| 312 | if (!list_empty(&pool->sp_threads) && |
| 313 | !list_empty(&pool->sp_sockets)) |
| 314 | printk(KERN_ERR |
| 315 | "svc_xprt_enqueue: " |
| 316 | "threads and transports both waiting??\n"); |
| 317 | |
| 318 | if (test_bit(XPT_DEAD, &xprt->xpt_flags)) { |
| 319 | /* Don't enqueue dead transports */ |
| 320 | dprintk("svc: transport %p is dead, not enqueued\n", xprt); |
| 321 | goto out_unlock; |
| 322 | } |
| 323 | |
| 324 | /* Mark transport as busy. It will remain in this state until |
| 325 | * the provider calls svc_xprt_received. We update XPT_BUSY |
| 326 | * atomically because it also guards against trying to enqueue |
| 327 | * the transport twice. |
| 328 | */ |
| 329 | if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) { |
| 330 | /* Don't enqueue transport while already enqueued */ |
| 331 | dprintk("svc: transport %p busy, not enqueued\n", xprt); |
| 332 | goto out_unlock; |
| 333 | } |
| 334 | BUG_ON(xprt->xpt_pool != NULL); |
| 335 | xprt->xpt_pool = pool; |
| 336 | |
| 337 | /* Handle pending connection */ |
| 338 | if (test_bit(XPT_CONN, &xprt->xpt_flags)) |
| 339 | goto process; |
| 340 | |
| 341 | /* Handle close in-progress */ |
| 342 | if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) |
| 343 | goto process; |
| 344 | |
| 345 | /* Check if we have space to reply to a request */ |
| 346 | if (!xprt->xpt_ops->xpo_has_wspace(xprt)) { |
| 347 | /* Don't enqueue while not enough space for reply */ |
| 348 | dprintk("svc: no write space, transport %p not enqueued\n", |
| 349 | xprt); |
| 350 | xprt->xpt_pool = NULL; |
| 351 | clear_bit(XPT_BUSY, &xprt->xpt_flags); |
| 352 | goto out_unlock; |
| 353 | } |
| 354 | |
| 355 | process: |
| 356 | if (!list_empty(&pool->sp_threads)) { |
| 357 | rqstp = list_entry(pool->sp_threads.next, |
| 358 | struct svc_rqst, |
| 359 | rq_list); |
| 360 | dprintk("svc: transport %p served by daemon %p\n", |
| 361 | xprt, rqstp); |
| 362 | svc_thread_dequeue(pool, rqstp); |
| 363 | if (rqstp->rq_xprt) |
| 364 | printk(KERN_ERR |
| 365 | "svc_xprt_enqueue: server %p, rq_xprt=%p!\n", |
| 366 | rqstp, rqstp->rq_xprt); |
| 367 | rqstp->rq_xprt = xprt; |
| 368 | svc_xprt_get(xprt); |
| 369 | rqstp->rq_reserved = serv->sv_max_mesg; |
| 370 | atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); |
| 371 | BUG_ON(xprt->xpt_pool != pool); |
| 372 | wake_up(&rqstp->rq_wait); |
| 373 | } else { |
| 374 | dprintk("svc: transport %p put into queue\n", xprt); |
| 375 | list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); |
| 376 | BUG_ON(xprt->xpt_pool != pool); |
| 377 | } |
| 378 | |
| 379 | out_unlock: |
| 380 | spin_unlock_bh(&pool->sp_lock); |
| 381 | } |
| 382 | EXPORT_SYMBOL_GPL(svc_xprt_enqueue); |
| 383 | |
| 384 | /* |
| 385 | * Dequeue the first transport. Must be called with the pool->sp_lock held. |
| 386 | */ |
| 387 | static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) |
| 388 | { |
| 389 | struct svc_xprt *xprt; |
| 390 | |
| 391 | if (list_empty(&pool->sp_sockets)) |
| 392 | return NULL; |
| 393 | |
| 394 | xprt = list_entry(pool->sp_sockets.next, |
| 395 | struct svc_xprt, xpt_ready); |
| 396 | list_del_init(&xprt->xpt_ready); |
| 397 | |
| 398 | dprintk("svc: transport %p dequeued, inuse=%d\n", |
| 399 | xprt, atomic_read(&xprt->xpt_ref.refcount)); |
| 400 | |
| 401 | return xprt; |
| 402 | } |
| 403 | |
| 404 | /* |
| 405 | * svc_xprt_received conditionally queues the transport for processing |
| 406 | * by another thread. The caller must hold the XPT_BUSY bit and must |
| 407 | * not thereafter touch transport data. |
| 408 | * |
| 409 | * Note: XPT_DATA only gets cleared when a read-attempt finds no (or |
| 410 | * insufficient) data. |
| 411 | */ |
| 412 | void svc_xprt_received(struct svc_xprt *xprt) |
| 413 | { |
| 414 | BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags)); |
| 415 | xprt->xpt_pool = NULL; |
| 416 | clear_bit(XPT_BUSY, &xprt->xpt_flags); |
| 417 | svc_xprt_enqueue(xprt); |
| 418 | } |
| 419 | EXPORT_SYMBOL_GPL(svc_xprt_received); |
| 420 | |
| 421 | /** |
| 422 | * svc_reserve - change the space reserved for the reply to a request. |
| 423 | * @rqstp: The request in question |
| 424 | * @space: new max space to reserve |
| 425 | * |
| 426 | * Each request reserves some space on the output queue of the transport |
| 427 | * to make sure the reply fits. This function reduces that reserved |
| 428 | * space to be the amount of space used already, plus @space. |
| 429 | * |
| 430 | */ |
| 431 | void svc_reserve(struct svc_rqst *rqstp, int space) |
| 432 | { |
| 433 | space += rqstp->rq_res.head[0].iov_len; |
| 434 | |
| 435 | if (space < rqstp->rq_reserved) { |
| 436 | struct svc_xprt *xprt = rqstp->rq_xprt; |
| 437 | atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved); |
| 438 | rqstp->rq_reserved = space; |
| 439 | |
| 440 | svc_xprt_enqueue(xprt); |
| 441 | } |
| 442 | } |
Trond Myklebust | d2f7e79 | 2007-07-14 15:39:58 -0400 | [diff] [blame] | 443 | EXPORT_SYMBOL(svc_reserve); |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 444 | |
| 445 | static void svc_xprt_release(struct svc_rqst *rqstp) |
| 446 | { |
| 447 | struct svc_xprt *xprt = rqstp->rq_xprt; |
| 448 | |
| 449 | rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); |
| 450 | |
| 451 | svc_free_res_pages(rqstp); |
| 452 | rqstp->rq_res.page_len = 0; |
| 453 | rqstp->rq_res.page_base = 0; |
| 454 | |
| 455 | /* Reset response buffer and release |
| 456 | * the reservation. |
| 457 | * But first, check that enough space was reserved |
| 458 | * for the reply, otherwise we have a bug! |
| 459 | */ |
| 460 | if ((rqstp->rq_res.len) > rqstp->rq_reserved) |
| 461 | printk(KERN_ERR "RPC request reserved %d but used %d\n", |
| 462 | rqstp->rq_reserved, |
| 463 | rqstp->rq_res.len); |
| 464 | |
| 465 | rqstp->rq_res.head[0].iov_len = 0; |
| 466 | svc_reserve(rqstp, 0); |
| 467 | rqstp->rq_xprt = NULL; |
| 468 | |
| 469 | svc_xprt_put(xprt); |
| 470 | } |
| 471 | |
| 472 | /* |
| 473 | * External function to wake up a server waiting for data |
| 474 | * This really only makes sense for services like lockd |
| 475 | * which have exactly one thread anyway. |
| 476 | */ |
| 477 | void svc_wake_up(struct svc_serv *serv) |
| 478 | { |
| 479 | struct svc_rqst *rqstp; |
| 480 | unsigned int i; |
| 481 | struct svc_pool *pool; |
| 482 | |
| 483 | for (i = 0; i < serv->sv_nrpools; i++) { |
| 484 | pool = &serv->sv_pools[i]; |
| 485 | |
| 486 | spin_lock_bh(&pool->sp_lock); |
| 487 | if (!list_empty(&pool->sp_threads)) { |
| 488 | rqstp = list_entry(pool->sp_threads.next, |
| 489 | struct svc_rqst, |
| 490 | rq_list); |
| 491 | dprintk("svc: daemon %p woken up.\n", rqstp); |
| 492 | /* |
| 493 | svc_thread_dequeue(pool, rqstp); |
| 494 | rqstp->rq_xprt = NULL; |
| 495 | */ |
| 496 | wake_up(&rqstp->rq_wait); |
| 497 | } |
| 498 | spin_unlock_bh(&pool->sp_lock); |
| 499 | } |
| 500 | } |
Trond Myklebust | d2f7e79 | 2007-07-14 15:39:58 -0400 | [diff] [blame] | 501 | EXPORT_SYMBOL(svc_wake_up); |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 502 | |
| 503 | int svc_port_is_privileged(struct sockaddr *sin) |
| 504 | { |
| 505 | switch (sin->sa_family) { |
| 506 | case AF_INET: |
| 507 | return ntohs(((struct sockaddr_in *)sin)->sin_port) |
| 508 | < PROT_SOCK; |
| 509 | case AF_INET6: |
| 510 | return ntohs(((struct sockaddr_in6 *)sin)->sin6_port) |
| 511 | < PROT_SOCK; |
| 512 | default: |
| 513 | return 0; |
| 514 | } |
| 515 | } |
| 516 | |
| 517 | /* |
| 518 | * Make sure that we don't have too many active connections. If we |
| 519 | * have, something must be dropped. |
| 520 | * |
| 521 | * There's no point in trying to do random drop here for DoS |
| 522 | * prevention. The NFS clients does 1 reconnect in 15 seconds. An |
| 523 | * attacker can easily beat that. |
| 524 | * |
| 525 | * The only somewhat efficient mechanism would be if drop old |
| 526 | * connections from the same IP first. But right now we don't even |
| 527 | * record the client IP in svc_sock. |
| 528 | */ |
| 529 | static void svc_check_conn_limits(struct svc_serv *serv) |
| 530 | { |
| 531 | if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*20) { |
| 532 | struct svc_xprt *xprt = NULL; |
| 533 | spin_lock_bh(&serv->sv_lock); |
| 534 | if (!list_empty(&serv->sv_tempsocks)) { |
| 535 | if (net_ratelimit()) { |
| 536 | /* Try to help the admin */ |
| 537 | printk(KERN_NOTICE "%s: too many open " |
| 538 | "connections, consider increasing the " |
| 539 | "number of nfsd threads\n", |
| 540 | serv->sv_name); |
| 541 | } |
| 542 | /* |
| 543 | * Always select the oldest connection. It's not fair, |
| 544 | * but so is life |
| 545 | */ |
| 546 | xprt = list_entry(serv->sv_tempsocks.prev, |
| 547 | struct svc_xprt, |
| 548 | xpt_list); |
| 549 | set_bit(XPT_CLOSE, &xprt->xpt_flags); |
| 550 | svc_xprt_get(xprt); |
| 551 | } |
| 552 | spin_unlock_bh(&serv->sv_lock); |
| 553 | |
| 554 | if (xprt) { |
| 555 | svc_xprt_enqueue(xprt); |
| 556 | svc_xprt_put(xprt); |
| 557 | } |
| 558 | } |
| 559 | } |
| 560 | |
| 561 | /* |
| 562 | * Receive the next request on any transport. This code is carefully |
| 563 | * organised not to touch any cachelines in the shared svc_serv |
| 564 | * structure, only cachelines in the local svc_pool. |
| 565 | */ |
| 566 | int svc_recv(struct svc_rqst *rqstp, long timeout) |
| 567 | { |
| 568 | struct svc_xprt *xprt = NULL; |
| 569 | struct svc_serv *serv = rqstp->rq_server; |
| 570 | struct svc_pool *pool = rqstp->rq_pool; |
| 571 | int len, i; |
| 572 | int pages; |
| 573 | struct xdr_buf *arg; |
| 574 | DECLARE_WAITQUEUE(wait, current); |
| 575 | |
| 576 | dprintk("svc: server %p waiting for data (to = %ld)\n", |
| 577 | rqstp, timeout); |
| 578 | |
| 579 | if (rqstp->rq_xprt) |
| 580 | printk(KERN_ERR |
| 581 | "svc_recv: service %p, transport not NULL!\n", |
| 582 | rqstp); |
| 583 | if (waitqueue_active(&rqstp->rq_wait)) |
| 584 | printk(KERN_ERR |
| 585 | "svc_recv: service %p, wait queue active!\n", |
| 586 | rqstp); |
| 587 | |
| 588 | /* now allocate needed pages. If we get a failure, sleep briefly */ |
| 589 | pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE; |
| 590 | for (i = 0; i < pages ; i++) |
| 591 | while (rqstp->rq_pages[i] == NULL) { |
| 592 | struct page *p = alloc_page(GFP_KERNEL); |
| 593 | if (!p) { |
Jeff Layton | 7b54fe6 | 2008-02-12 11:47:24 -0500 | [diff] [blame] | 594 | set_current_state(TASK_INTERRUPTIBLE); |
| 595 | if (signalled() || kthread_should_stop()) { |
| 596 | set_current_state(TASK_RUNNING); |
Jeff Layton | 7086721 | 2008-02-07 16:34:54 -0500 | [diff] [blame] | 597 | return -EINTR; |
Jeff Layton | 7b54fe6 | 2008-02-12 11:47:24 -0500 | [diff] [blame] | 598 | } |
| 599 | schedule_timeout(msecs_to_jiffies(500)); |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 600 | } |
| 601 | rqstp->rq_pages[i] = p; |
| 602 | } |
| 603 | rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */ |
| 604 | BUG_ON(pages >= RPCSVC_MAXPAGES); |
| 605 | |
| 606 | /* Make arg->head point to first page and arg->pages point to rest */ |
| 607 | arg = &rqstp->rq_arg; |
| 608 | arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); |
| 609 | arg->head[0].iov_len = PAGE_SIZE; |
| 610 | arg->pages = rqstp->rq_pages + 1; |
| 611 | arg->page_base = 0; |
| 612 | /* save at least one page for response */ |
| 613 | arg->page_len = (pages-2)*PAGE_SIZE; |
| 614 | arg->len = (pages-1)*PAGE_SIZE; |
| 615 | arg->tail[0].iov_len = 0; |
| 616 | |
| 617 | try_to_freeze(); |
| 618 | cond_resched(); |
Jeff Layton | 7086721 | 2008-02-07 16:34:54 -0500 | [diff] [blame] | 619 | if (signalled() || kthread_should_stop()) |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 620 | return -EINTR; |
| 621 | |
| 622 | spin_lock_bh(&pool->sp_lock); |
| 623 | xprt = svc_xprt_dequeue(pool); |
| 624 | if (xprt) { |
| 625 | rqstp->rq_xprt = xprt; |
| 626 | svc_xprt_get(xprt); |
| 627 | rqstp->rq_reserved = serv->sv_max_mesg; |
| 628 | atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); |
| 629 | } else { |
| 630 | /* No data pending. Go to sleep */ |
| 631 | svc_thread_enqueue(pool, rqstp); |
| 632 | |
| 633 | /* |
| 634 | * We have to be able to interrupt this wait |
| 635 | * to bring down the daemons ... |
| 636 | */ |
| 637 | set_current_state(TASK_INTERRUPTIBLE); |
Jeff Layton | 7086721 | 2008-02-07 16:34:54 -0500 | [diff] [blame] | 638 | |
| 639 | /* |
| 640 | * checking kthread_should_stop() here allows us to avoid |
| 641 | * locking and signalling when stopping kthreads that call |
| 642 | * svc_recv. If the thread has already been woken up, then |
| 643 | * we can exit here without sleeping. If not, then it |
| 644 | * it'll be woken up quickly during the schedule_timeout |
| 645 | */ |
| 646 | if (kthread_should_stop()) { |
| 647 | set_current_state(TASK_RUNNING); |
| 648 | spin_unlock_bh(&pool->sp_lock); |
| 649 | return -EINTR; |
| 650 | } |
| 651 | |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 652 | add_wait_queue(&rqstp->rq_wait, &wait); |
| 653 | spin_unlock_bh(&pool->sp_lock); |
| 654 | |
| 655 | schedule_timeout(timeout); |
| 656 | |
| 657 | try_to_freeze(); |
| 658 | |
| 659 | spin_lock_bh(&pool->sp_lock); |
| 660 | remove_wait_queue(&rqstp->rq_wait, &wait); |
| 661 | |
| 662 | xprt = rqstp->rq_xprt; |
| 663 | if (!xprt) { |
| 664 | svc_thread_dequeue(pool, rqstp); |
| 665 | spin_unlock_bh(&pool->sp_lock); |
| 666 | dprintk("svc: server %p, no data yet\n", rqstp); |
Jeff Layton | 7086721 | 2008-02-07 16:34:54 -0500 | [diff] [blame] | 667 | if (signalled() || kthread_should_stop()) |
| 668 | return -EINTR; |
| 669 | else |
| 670 | return -EAGAIN; |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 671 | } |
| 672 | } |
| 673 | spin_unlock_bh(&pool->sp_lock); |
| 674 | |
| 675 | len = 0; |
| 676 | if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { |
| 677 | dprintk("svc_recv: found XPT_CLOSE\n"); |
| 678 | svc_delete_xprt(xprt); |
| 679 | } else if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { |
| 680 | struct svc_xprt *newxpt; |
| 681 | newxpt = xprt->xpt_ops->xpo_accept(xprt); |
| 682 | if (newxpt) { |
| 683 | /* |
| 684 | * We know this module_get will succeed because the |
| 685 | * listener holds a reference too |
| 686 | */ |
| 687 | __module_get(newxpt->xpt_class->xcl_owner); |
| 688 | svc_check_conn_limits(xprt->xpt_server); |
| 689 | spin_lock_bh(&serv->sv_lock); |
| 690 | set_bit(XPT_TEMP, &newxpt->xpt_flags); |
| 691 | list_add(&newxpt->xpt_list, &serv->sv_tempsocks); |
| 692 | serv->sv_tmpcnt++; |
| 693 | if (serv->sv_temptimer.function == NULL) { |
| 694 | /* setup timer to age temp transports */ |
| 695 | setup_timer(&serv->sv_temptimer, |
| 696 | svc_age_temp_xprts, |
| 697 | (unsigned long)serv); |
| 698 | mod_timer(&serv->sv_temptimer, |
| 699 | jiffies + svc_conn_age_period * HZ); |
| 700 | } |
| 701 | spin_unlock_bh(&serv->sv_lock); |
| 702 | svc_xprt_received(newxpt); |
| 703 | } |
| 704 | svc_xprt_received(xprt); |
| 705 | } else { |
| 706 | dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", |
| 707 | rqstp, pool->sp_id, xprt, |
| 708 | atomic_read(&xprt->xpt_ref.refcount)); |
| 709 | rqstp->rq_deferred = svc_deferred_dequeue(xprt); |
| 710 | if (rqstp->rq_deferred) { |
| 711 | svc_xprt_received(xprt); |
| 712 | len = svc_deferred_recv(rqstp); |
| 713 | } else |
| 714 | len = xprt->xpt_ops->xpo_recvfrom(rqstp); |
| 715 | dprintk("svc: got len=%d\n", len); |
| 716 | } |
| 717 | |
| 718 | /* No data, incomplete (TCP) read, or accept() */ |
| 719 | if (len == 0 || len == -EAGAIN) { |
| 720 | rqstp->rq_res.len = 0; |
| 721 | svc_xprt_release(rqstp); |
| 722 | return -EAGAIN; |
| 723 | } |
| 724 | clear_bit(XPT_OLD, &xprt->xpt_flags); |
| 725 | |
| 726 | rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp)); |
| 727 | rqstp->rq_chandle.defer = svc_defer; |
| 728 | |
| 729 | if (serv->sv_stats) |
| 730 | serv->sv_stats->netcnt++; |
| 731 | return len; |
| 732 | } |
Trond Myklebust | d2f7e79 | 2007-07-14 15:39:58 -0400 | [diff] [blame] | 733 | EXPORT_SYMBOL(svc_recv); |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 734 | |
| 735 | /* |
| 736 | * Drop request |
| 737 | */ |
| 738 | void svc_drop(struct svc_rqst *rqstp) |
| 739 | { |
| 740 | dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt); |
| 741 | svc_xprt_release(rqstp); |
| 742 | } |
Trond Myklebust | d2f7e79 | 2007-07-14 15:39:58 -0400 | [diff] [blame] | 743 | EXPORT_SYMBOL(svc_drop); |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 744 | |
| 745 | /* |
| 746 | * Return reply to client. |
| 747 | */ |
| 748 | int svc_send(struct svc_rqst *rqstp) |
| 749 | { |
| 750 | struct svc_xprt *xprt; |
| 751 | int len; |
| 752 | struct xdr_buf *xb; |
| 753 | |
| 754 | xprt = rqstp->rq_xprt; |
| 755 | if (!xprt) |
| 756 | return -EFAULT; |
| 757 | |
| 758 | /* release the receive skb before sending the reply */ |
| 759 | rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); |
| 760 | |
| 761 | /* calculate over-all length */ |
| 762 | xb = &rqstp->rq_res; |
| 763 | xb->len = xb->head[0].iov_len + |
| 764 | xb->page_len + |
| 765 | xb->tail[0].iov_len; |
| 766 | |
| 767 | /* Grab mutex to serialize outgoing data. */ |
| 768 | mutex_lock(&xprt->xpt_mutex); |
| 769 | if (test_bit(XPT_DEAD, &xprt->xpt_flags)) |
| 770 | len = -ENOTCONN; |
| 771 | else |
| 772 | len = xprt->xpt_ops->xpo_sendto(rqstp); |
| 773 | mutex_unlock(&xprt->xpt_mutex); |
| 774 | svc_xprt_release(rqstp); |
| 775 | |
| 776 | if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN) |
| 777 | return 0; |
| 778 | return len; |
| 779 | } |
| 780 | |
| 781 | /* |
| 782 | * Timer function to close old temporary transports, using |
| 783 | * a mark-and-sweep algorithm. |
| 784 | */ |
| 785 | static void svc_age_temp_xprts(unsigned long closure) |
| 786 | { |
| 787 | struct svc_serv *serv = (struct svc_serv *)closure; |
| 788 | struct svc_xprt *xprt; |
| 789 | struct list_head *le, *next; |
| 790 | LIST_HEAD(to_be_aged); |
| 791 | |
| 792 | dprintk("svc_age_temp_xprts\n"); |
| 793 | |
| 794 | if (!spin_trylock_bh(&serv->sv_lock)) { |
| 795 | /* busy, try again 1 sec later */ |
| 796 | dprintk("svc_age_temp_xprts: busy\n"); |
| 797 | mod_timer(&serv->sv_temptimer, jiffies + HZ); |
| 798 | return; |
| 799 | } |
| 800 | |
| 801 | list_for_each_safe(le, next, &serv->sv_tempsocks) { |
| 802 | xprt = list_entry(le, struct svc_xprt, xpt_list); |
| 803 | |
| 804 | /* First time through, just mark it OLD. Second time |
| 805 | * through, close it. */ |
| 806 | if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) |
| 807 | continue; |
| 808 | if (atomic_read(&xprt->xpt_ref.refcount) > 1 |
| 809 | || test_bit(XPT_BUSY, &xprt->xpt_flags)) |
| 810 | continue; |
| 811 | svc_xprt_get(xprt); |
| 812 | list_move(le, &to_be_aged); |
| 813 | set_bit(XPT_CLOSE, &xprt->xpt_flags); |
| 814 | set_bit(XPT_DETACHED, &xprt->xpt_flags); |
| 815 | } |
| 816 | spin_unlock_bh(&serv->sv_lock); |
| 817 | |
| 818 | while (!list_empty(&to_be_aged)) { |
| 819 | le = to_be_aged.next; |
| 820 | /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */ |
| 821 | list_del_init(le); |
| 822 | xprt = list_entry(le, struct svc_xprt, xpt_list); |
| 823 | |
| 824 | dprintk("queuing xprt %p for closing\n", xprt); |
| 825 | |
| 826 | /* a thread will dequeue and close it soon */ |
| 827 | svc_xprt_enqueue(xprt); |
| 828 | svc_xprt_put(xprt); |
| 829 | } |
| 830 | |
| 831 | mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); |
| 832 | } |
| 833 | |
| 834 | /* |
| 835 | * Remove a dead transport |
| 836 | */ |
| 837 | void svc_delete_xprt(struct svc_xprt *xprt) |
| 838 | { |
| 839 | struct svc_serv *serv = xprt->xpt_server; |
| 840 | |
| 841 | dprintk("svc: svc_delete_xprt(%p)\n", xprt); |
| 842 | xprt->xpt_ops->xpo_detach(xprt); |
| 843 | |
| 844 | spin_lock_bh(&serv->sv_lock); |
| 845 | if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags)) |
| 846 | list_del_init(&xprt->xpt_list); |
| 847 | /* |
| 848 | * We used to delete the transport from whichever list |
| 849 | * it's sk_xprt.xpt_ready node was on, but we don't actually |
| 850 | * need to. This is because the only time we're called |
| 851 | * while still attached to a queue, the queue itself |
| 852 | * is about to be destroyed (in svc_destroy). |
| 853 | */ |
| 854 | if (!test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) { |
| 855 | BUG_ON(atomic_read(&xprt->xpt_ref.refcount) < 2); |
| 856 | if (test_bit(XPT_TEMP, &xprt->xpt_flags)) |
| 857 | serv->sv_tmpcnt--; |
| 858 | svc_xprt_put(xprt); |
| 859 | } |
| 860 | spin_unlock_bh(&serv->sv_lock); |
| 861 | } |
| 862 | |
| 863 | void svc_close_xprt(struct svc_xprt *xprt) |
| 864 | { |
| 865 | set_bit(XPT_CLOSE, &xprt->xpt_flags); |
| 866 | if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) |
| 867 | /* someone else will have to effect the close */ |
| 868 | return; |
| 869 | |
| 870 | svc_xprt_get(xprt); |
| 871 | svc_delete_xprt(xprt); |
| 872 | clear_bit(XPT_BUSY, &xprt->xpt_flags); |
| 873 | svc_xprt_put(xprt); |
| 874 | } |
Tom Tucker | a217813 | 2007-12-30 21:08:35 -0600 | [diff] [blame] | 875 | EXPORT_SYMBOL_GPL(svc_close_xprt); |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 876 | |
| 877 | void svc_close_all(struct list_head *xprt_list) |
| 878 | { |
| 879 | struct svc_xprt *xprt; |
| 880 | struct svc_xprt *tmp; |
| 881 | |
| 882 | list_for_each_entry_safe(xprt, tmp, xprt_list, xpt_list) { |
| 883 | set_bit(XPT_CLOSE, &xprt->xpt_flags); |
| 884 | if (test_bit(XPT_BUSY, &xprt->xpt_flags)) { |
| 885 | /* Waiting to be processed, but no threads left, |
| 886 | * So just remove it from the waiting list |
| 887 | */ |
| 888 | list_del_init(&xprt->xpt_ready); |
| 889 | clear_bit(XPT_BUSY, &xprt->xpt_flags); |
| 890 | } |
| 891 | svc_close_xprt(xprt); |
| 892 | } |
| 893 | } |
| 894 | |
| 895 | /* |
| 896 | * Handle defer and revisit of requests |
| 897 | */ |
| 898 | |
| 899 | static void svc_revisit(struct cache_deferred_req *dreq, int too_many) |
| 900 | { |
| 901 | struct svc_deferred_req *dr = |
| 902 | container_of(dreq, struct svc_deferred_req, handle); |
| 903 | struct svc_xprt *xprt = dr->xprt; |
| 904 | |
| 905 | if (too_many) { |
| 906 | svc_xprt_put(xprt); |
| 907 | kfree(dr); |
| 908 | return; |
| 909 | } |
| 910 | dprintk("revisit queued\n"); |
| 911 | dr->xprt = NULL; |
| 912 | spin_lock(&xprt->xpt_lock); |
| 913 | list_add(&dr->handle.recent, &xprt->xpt_deferred); |
| 914 | spin_unlock(&xprt->xpt_lock); |
| 915 | set_bit(XPT_DEFERRED, &xprt->xpt_flags); |
| 916 | svc_xprt_enqueue(xprt); |
| 917 | svc_xprt_put(xprt); |
| 918 | } |
| 919 | |
Tom Tucker | 260c1d1 | 2007-12-30 21:08:29 -0600 | [diff] [blame] | 920 | /* |
| 921 | * Save the request off for later processing. The request buffer looks |
| 922 | * like this: |
| 923 | * |
| 924 | * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> |
| 925 | * |
| 926 | * This code can only handle requests that consist of an xprt-header |
| 927 | * and rpc-header. |
| 928 | */ |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 929 | static struct cache_deferred_req *svc_defer(struct cache_req *req) |
| 930 | { |
| 931 | struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 932 | struct svc_deferred_req *dr; |
| 933 | |
| 934 | if (rqstp->rq_arg.page_len) |
| 935 | return NULL; /* if more than a page, give up FIXME */ |
| 936 | if (rqstp->rq_deferred) { |
| 937 | dr = rqstp->rq_deferred; |
| 938 | rqstp->rq_deferred = NULL; |
| 939 | } else { |
Tom Tucker | 260c1d1 | 2007-12-30 21:08:29 -0600 | [diff] [blame] | 940 | size_t skip; |
| 941 | size_t size; |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 942 | /* FIXME maybe discard if size too large */ |
Tom Tucker | 260c1d1 | 2007-12-30 21:08:29 -0600 | [diff] [blame] | 943 | size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 944 | dr = kmalloc(size, GFP_KERNEL); |
| 945 | if (dr == NULL) |
| 946 | return NULL; |
| 947 | |
| 948 | dr->handle.owner = rqstp->rq_server; |
| 949 | dr->prot = rqstp->rq_prot; |
| 950 | memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); |
| 951 | dr->addrlen = rqstp->rq_addrlen; |
| 952 | dr->daddr = rqstp->rq_daddr; |
| 953 | dr->argslen = rqstp->rq_arg.len >> 2; |
Tom Tucker | 260c1d1 | 2007-12-30 21:08:29 -0600 | [diff] [blame] | 954 | dr->xprt_hlen = rqstp->rq_xprt_hlen; |
| 955 | |
| 956 | /* back up head to the start of the buffer and copy */ |
| 957 | skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; |
| 958 | memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, |
| 959 | dr->argslen << 2); |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 960 | } |
| 961 | svc_xprt_get(rqstp->rq_xprt); |
| 962 | dr->xprt = rqstp->rq_xprt; |
| 963 | |
| 964 | dr->handle.revisit = svc_revisit; |
| 965 | return &dr->handle; |
| 966 | } |
| 967 | |
| 968 | /* |
| 969 | * recv data from a deferred request into an active one |
| 970 | */ |
| 971 | static int svc_deferred_recv(struct svc_rqst *rqstp) |
| 972 | { |
| 973 | struct svc_deferred_req *dr = rqstp->rq_deferred; |
| 974 | |
Tom Tucker | 260c1d1 | 2007-12-30 21:08:29 -0600 | [diff] [blame] | 975 | /* setup iov_base past transport header */ |
| 976 | rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2); |
| 977 | /* The iov_len does not include the transport header bytes */ |
| 978 | rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen; |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 979 | rqstp->rq_arg.page_len = 0; |
Tom Tucker | 260c1d1 | 2007-12-30 21:08:29 -0600 | [diff] [blame] | 980 | /* The rq_arg.len includes the transport header bytes */ |
| 981 | rqstp->rq_arg.len = dr->argslen<<2; |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 982 | rqstp->rq_prot = dr->prot; |
| 983 | memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); |
| 984 | rqstp->rq_addrlen = dr->addrlen; |
Tom Tucker | 260c1d1 | 2007-12-30 21:08:29 -0600 | [diff] [blame] | 985 | /* Save off transport header len in case we get deferred again */ |
| 986 | rqstp->rq_xprt_hlen = dr->xprt_hlen; |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 987 | rqstp->rq_daddr = dr->daddr; |
| 988 | rqstp->rq_respages = rqstp->rq_pages; |
Tom Tucker | 260c1d1 | 2007-12-30 21:08:29 -0600 | [diff] [blame] | 989 | return (dr->argslen<<2) - dr->xprt_hlen; |
Tom Tucker | 0f0257e | 2007-12-30 21:08:27 -0600 | [diff] [blame] | 990 | } |
| 991 | |
| 992 | |
| 993 | static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) |
| 994 | { |
| 995 | struct svc_deferred_req *dr = NULL; |
| 996 | |
| 997 | if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) |
| 998 | return NULL; |
| 999 | spin_lock(&xprt->xpt_lock); |
| 1000 | clear_bit(XPT_DEFERRED, &xprt->xpt_flags); |
| 1001 | if (!list_empty(&xprt->xpt_deferred)) { |
| 1002 | dr = list_entry(xprt->xpt_deferred.next, |
| 1003 | struct svc_deferred_req, |
| 1004 | handle.recent); |
| 1005 | list_del_init(&dr->handle.recent); |
| 1006 | set_bit(XPT_DEFERRED, &xprt->xpt_flags); |
| 1007 | } |
| 1008 | spin_unlock(&xprt->xpt_lock); |
| 1009 | return dr; |
| 1010 | } |
Tom Tucker | 7fcb98d | 2007-12-30 21:08:33 -0600 | [diff] [blame] | 1011 | |
| 1012 | /* |
| 1013 | * Return the transport instance pointer for the endpoint accepting |
| 1014 | * connections/peer traffic from the specified transport class, |
| 1015 | * address family and port. |
| 1016 | * |
| 1017 | * Specifying 0 for the address family or port is effectively a |
| 1018 | * wild-card, and will result in matching the first transport in the |
| 1019 | * service's list that has a matching class name. |
| 1020 | */ |
| 1021 | struct svc_xprt *svc_find_xprt(struct svc_serv *serv, char *xcl_name, |
| 1022 | int af, int port) |
| 1023 | { |
| 1024 | struct svc_xprt *xprt; |
| 1025 | struct svc_xprt *found = NULL; |
| 1026 | |
| 1027 | /* Sanity check the args */ |
| 1028 | if (!serv || !xcl_name) |
| 1029 | return found; |
| 1030 | |
| 1031 | spin_lock_bh(&serv->sv_lock); |
| 1032 | list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { |
| 1033 | if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) |
| 1034 | continue; |
| 1035 | if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) |
| 1036 | continue; |
| 1037 | if (port && port != svc_xprt_local_port(xprt)) |
| 1038 | continue; |
| 1039 | found = xprt; |
Tom Tucker | a217813 | 2007-12-30 21:08:35 -0600 | [diff] [blame] | 1040 | svc_xprt_get(xprt); |
Tom Tucker | 7fcb98d | 2007-12-30 21:08:33 -0600 | [diff] [blame] | 1041 | break; |
| 1042 | } |
| 1043 | spin_unlock_bh(&serv->sv_lock); |
| 1044 | return found; |
| 1045 | } |
| 1046 | EXPORT_SYMBOL_GPL(svc_find_xprt); |
Tom Tucker | 9571af1 | 2007-12-30 21:08:37 -0600 | [diff] [blame] | 1047 | |
| 1048 | /* |
| 1049 | * Format a buffer with a list of the active transports. A zero for |
| 1050 | * the buflen parameter disables target buffer overflow checking. |
| 1051 | */ |
| 1052 | int svc_xprt_names(struct svc_serv *serv, char *buf, int buflen) |
| 1053 | { |
| 1054 | struct svc_xprt *xprt; |
| 1055 | char xprt_str[64]; |
| 1056 | int totlen = 0; |
| 1057 | int len; |
| 1058 | |
| 1059 | /* Sanity check args */ |
| 1060 | if (!serv) |
| 1061 | return 0; |
| 1062 | |
| 1063 | spin_lock_bh(&serv->sv_lock); |
| 1064 | list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { |
| 1065 | len = snprintf(xprt_str, sizeof(xprt_str), |
| 1066 | "%s %d\n", xprt->xpt_class->xcl_name, |
| 1067 | svc_xprt_local_port(xprt)); |
| 1068 | /* If the string was truncated, replace with error string */ |
| 1069 | if (len >= sizeof(xprt_str)) |
| 1070 | strcpy(xprt_str, "name-too-long\n"); |
| 1071 | /* Don't overflow buffer */ |
| 1072 | len = strlen(xprt_str); |
| 1073 | if (buflen && (len + totlen >= buflen)) |
| 1074 | break; |
| 1075 | strcpy(buf+totlen, xprt_str); |
| 1076 | totlen += len; |
| 1077 | } |
| 1078 | spin_unlock_bh(&serv->sv_lock); |
| 1079 | return totlen; |
| 1080 | } |
| 1081 | EXPORT_SYMBOL_GPL(svc_xprt_names); |