git.oblomov.eu Git - linux-2.6/blob - fs/afs/cmservice.c

   1 /* cmservice.c: AFS Cache Manager Service
   2  *
   3  * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/sched.h>
  15 #include <linux/completion.h>
  16 #include "server.h"
  17 #include "cell.h"
  18 #include "transport.h"
  19 #include <rxrpc/rxrpc.h>
  20 #include <rxrpc/transport.h>
  21 #include <rxrpc/connection.h>
  22 #include <rxrpc/call.h>
  23 #include "cmservice.h"
  24 #include "internal.h"
  25
  26 static unsigned afscm_usage;            /* AFS cache manager usage count */
  27 static struct rw_semaphore afscm_sem;   /* AFS cache manager start/stop semaphore */
  28
  29 static int afscm_new_call(struct rxrpc_call *call);
  30 static void afscm_attention(struct rxrpc_call *call);
  31 static void afscm_error(struct rxrpc_call *call);
  32 static void afscm_aemap(struct rxrpc_call *call);
  33
  34 static void _SRXAFSCM_CallBack(struct rxrpc_call *call);
  35 static void _SRXAFSCM_InitCallBackState(struct rxrpc_call *call);
  36 static void _SRXAFSCM_Probe(struct rxrpc_call *call);
  37
  38 typedef void (*_SRXAFSCM_xxxx_t)(struct rxrpc_call *call);
  39
  40 static const struct rxrpc_operation AFSCM_ops[] = {
  41         {
  42                 .id     = 204,
  43                 .asize  = RXRPC_APP_MARK_EOF,
  44                 .name   = "CallBack",
  45                 .user   = _SRXAFSCM_CallBack,
  46         },
  47         {
  48                 .id     = 205,
  49                 .asize  = RXRPC_APP_MARK_EOF,
  50                 .name   = "InitCallBackState",
  51                 .user   = _SRXAFSCM_InitCallBackState,
  52         },
  53         {
  54                 .id     = 206,
  55                 .asize  = RXRPC_APP_MARK_EOF,
  56                 .name   = "Probe",
  57                 .user   = _SRXAFSCM_Probe,
  58         },
  59 #if 0
  60         {
  61                 .id     = 207,
  62                 .asize  = RXRPC_APP_MARK_EOF,
  63                 .name   = "GetLock",
  64                 .user   = _SRXAFSCM_GetLock,
  65         },
  66         {
  67                 .id     = 208,
  68                 .asize  = RXRPC_APP_MARK_EOF,
  69                 .name   = "GetCE",
  70                 .user   = _SRXAFSCM_GetCE,
  71         },
  72         {
  73                 .id     = 209,
  74                 .asize  = RXRPC_APP_MARK_EOF,
  75                 .name   = "GetXStatsVersion",
  76                 .user   = _SRXAFSCM_GetXStatsVersion,
  77         },
  78         {
  79                 .id     = 210,
  80                 .asize  = RXRPC_APP_MARK_EOF,
  81                 .name   = "GetXStats",
  82                 .user   = _SRXAFSCM_GetXStats,
  83         }
  84 #endif
  85 };
  86
  87 static struct rxrpc_service AFSCM_service = {
  88         .name           = "AFS/CM",
  89         .owner          = THIS_MODULE,
  90         .link           = LIST_HEAD_INIT(AFSCM_service.link),
  91         .new_call       = afscm_new_call,
  92         .service_id     = 1,
  93         .attn_func      = afscm_attention,
  94         .error_func     = afscm_error,
  95         .aemap_func     = afscm_aemap,
  96         .ops_begin      = &AFSCM_ops[0],
  97         .ops_end        = &AFSCM_ops[ARRAY_SIZE(AFSCM_ops)],
  98 };
  99
 100 static DECLARE_COMPLETION(kafscmd_alive);
 101 static DECLARE_COMPLETION(kafscmd_dead);
 102 static DECLARE_WAIT_QUEUE_HEAD(kafscmd_sleepq);
 103 static LIST_HEAD(kafscmd_attention_list);
 104 static LIST_HEAD(afscm_calls);
 105 static DEFINE_SPINLOCK(afscm_calls_lock);
 106 static DEFINE_SPINLOCK(kafscmd_attention_lock);
 107 static int kafscmd_die;
 108
 109 /*****************************************************************************/
 110 /*
 111  * AFS Cache Manager kernel thread
 112  */
 113 static int kafscmd(void *arg)
 114 {
 115         DECLARE_WAITQUEUE(myself, current);
 116
 117         struct rxrpc_call *call;
 118         _SRXAFSCM_xxxx_t func;
 119         int die;
 120
 121         printk(KERN_INFO "kAFS: Started kafscmd %d\n", current->pid);
 122
 123         daemonize("kafscmd");
 124
 125         complete(&kafscmd_alive);
 126
 127         /* loop around looking for things to attend to */
 128         do {
 129                 if (list_empty(&kafscmd_attention_list)) {
 130                         set_current_state(TASK_INTERRUPTIBLE);
 131                         add_wait_queue(&kafscmd_sleepq, &myself);
 132
 133                         for (;;) {
 134                                 set_current_state(TASK_INTERRUPTIBLE);
 135                                 if (!list_empty(&kafscmd_attention_list) ||
 136                                     signal_pending(current) ||
 137                                     kafscmd_die)
 138                                         break;
 139
 140                                 schedule();
 141                         }
 142
 143                         remove_wait_queue(&kafscmd_sleepq, &myself);
 144                         set_current_state(TASK_RUNNING);
 145                 }
 146
 147                 die = kafscmd_die;
 148
 149                 /* dequeue the next call requiring attention */
 150                 call = NULL;
 151                 spin_lock(&kafscmd_attention_lock);
 152
 153                 if (!list_empty(&kafscmd_attention_list)) {
 154                         call = list_entry(kafscmd_attention_list.next,
 155                                           struct rxrpc_call,
 156                                           app_attn_link);
 157                         list_del_init(&call->app_attn_link);
 158                         die = 0;
 159                 }
 160
 161                 spin_unlock(&kafscmd_attention_lock);
 162
 163                 if (call) {
 164                         /* act upon it */
 165                         _debug("@@@ Begin Attend Call %p", call);
 166
 167                         func = call->app_user;
 168                         if (func)
 169                                 func(call);
 170
 171                         rxrpc_put_call(call);
 172
 173                         _debug("@@@ End Attend Call %p", call);
 174                 }
 175
 176         } while(!die);
 177
 178         /* and that's all */
 179         complete_and_exit(&kafscmd_dead, 0);
 180
 181 } /* end kafscmd() */
 182
 183 /*****************************************************************************/
 184 /*
 185  * handle a call coming in to the cache manager
 186  * - if I want to keep the call, I must increment its usage count
 187  * - the return value will be negated and passed back in an abort packet if
 188  *   non-zero
 189  * - serialised by virtue of there only being one krxiod
 190  */
 191 static int afscm_new_call(struct rxrpc_call *call)
 192 {
 193         _enter("%p{cid=%u u=%d}",
 194                call, ntohl(call->call_id), atomic_read(&call->usage));
 195
 196         rxrpc_get_call(call);
 197
 198         /* add to my current call list */
 199         spin_lock(&afscm_calls_lock);
 200         list_add(&call->app_link,&afscm_calls);
 201         spin_unlock(&afscm_calls_lock);
 202
 203         _leave(" = 0");
 204         return 0;
 205
 206 } /* end afscm_new_call() */
 207
 208 /*****************************************************************************/
 209 /*
 210  * queue on the kafscmd queue for attention
 211  */
 212 static void afscm_attention(struct rxrpc_call *call)
 213 {
 214         _enter("%p{cid=%u u=%d}",
 215                call, ntohl(call->call_id), atomic_read(&call->usage));
 216
 217         spin_lock(&kafscmd_attention_lock);
 218
 219         if (list_empty(&call->app_attn_link)) {
 220                 list_add_tail(&call->app_attn_link, &kafscmd_attention_list);
 221                 rxrpc_get_call(call);
 222         }
 223
 224         spin_unlock(&kafscmd_attention_lock);
 225
 226         wake_up(&kafscmd_sleepq);
 227
 228         _leave(" {u=%d}", atomic_read(&call->usage));
 229 } /* end afscm_attention() */
 230
 231 /*****************************************************************************/
 232 /*
 233  * handle my call being aborted
 234  * - clean up, dequeue and put my ref to the call
 235  */
 236 static void afscm_error(struct rxrpc_call *call)
 237 {
 238         int removed;
 239
 240         _enter("%p{est=%s ac=%u er=%d}",
 241                call,
 242                rxrpc_call_error_states[call->app_err_state],
 243                call->app_abort_code,
 244                call->app_errno);
 245
 246         spin_lock(&kafscmd_attention_lock);
 247
 248         if (list_empty(&call->app_attn_link)) {
 249                 list_add_tail(&call->app_attn_link, &kafscmd_attention_list);
 250                 rxrpc_get_call(call);
 251         }
 252
 253         spin_unlock(&kafscmd_attention_lock);
 254
 255         removed = 0;
 256         spin_lock(&afscm_calls_lock);
 257         if (!list_empty(&call->app_link)) {
 258                 list_del_init(&call->app_link);
 259                 removed = 1;
 260         }
 261         spin_unlock(&afscm_calls_lock);
 262
 263         if (removed)
 264                 rxrpc_put_call(call);
 265
 266         wake_up(&kafscmd_sleepq);
 267
 268         _leave("");
 269 } /* end afscm_error() */
 270
 271 /*****************************************************************************/
 272 /*
 273  * map afs abort codes to/from Linux error codes
 274  * - called with call->lock held
 275  */
 276 static void afscm_aemap(struct rxrpc_call *call)
 277 {
 278         switch (call->app_err_state) {
 279         case RXRPC_ESTATE_LOCAL_ABORT:
 280                 call->app_abort_code = -call->app_errno;
 281                 break;
 282         case RXRPC_ESTATE_PEER_ABORT:
 283                 call->app_errno = -ECONNABORTED;
 284                 break;
 285         default:
 286                 break;
 287         }
 288 } /* end afscm_aemap() */
 289
 290 /*****************************************************************************/
 291 /*
 292  * start the cache manager service if not already started
 293  */
 294 int afscm_start(void)
 295 {
 296         int ret;
 297
 298         down_write(&afscm_sem);
 299         if (!afscm_usage) {
 300                 ret = kernel_thread(kafscmd, NULL, 0);
 301                 if (ret < 0)
 302                         goto out;
 303
 304                 wait_for_completion(&kafscmd_alive);
 305
 306                 ret = rxrpc_add_service(afs_transport, &AFSCM_service);
 307                 if (ret < 0)
 308                         goto kill;
 309
 310                 afs_kafstimod_add_timer(&afs_mntpt_expiry_timer,
 311                                         afs_mntpt_expiry_timeout * HZ);
 312         }
 313
 314         afscm_usage++;
 315         up_write(&afscm_sem);
 316
 317         return 0;
 318
 319  kill:
 320         kafscmd_die = 1;
 321         wake_up(&kafscmd_sleepq);
 322         wait_for_completion(&kafscmd_dead);
 323
 324  out:
 325         up_write(&afscm_sem);
 326         return ret;
 327
 328 } /* end afscm_start() */
 329
 330 /*****************************************************************************/
 331 /*
 332  * stop the cache manager service
 333  */
 334 void afscm_stop(void)
 335 {
 336         struct rxrpc_call *call;
 337
 338         down_write(&afscm_sem);
 339
 340         BUG_ON(afscm_usage == 0);
 341         afscm_usage--;
 342
 343         if (afscm_usage == 0) {
 344                 /* don't want more incoming calls */
 345                 rxrpc_del_service(afs_transport, &AFSCM_service);
 346
 347                 /* abort any calls I've still got open (the afscm_error() will
 348                  * dequeue them) */
 349                 spin_lock(&afscm_calls_lock);
 350                 while (!list_empty(&afscm_calls)) {
 351                         call = list_entry(afscm_calls.next,
 352                                           struct rxrpc_call,
 353                                           app_link);
 354
 355                         list_del_init(&call->app_link);
 356                         rxrpc_get_call(call);
 357                         spin_unlock(&afscm_calls_lock);
 358
 359                         rxrpc_call_abort(call, -ESRCH); /* abort, dequeue and
 360                                                          * put */
 361
 362                         _debug("nuking active call %08x.%d",
 363                                ntohl(call->conn->conn_id),
 364                                ntohl(call->call_id));
 365                         rxrpc_put_call(call);
 366                         rxrpc_put_call(call);
 367
 368                         spin_lock(&afscm_calls_lock);
 369                 }
 370                 spin_unlock(&afscm_calls_lock);
 371
 372                 /* get rid of my daemon */
 373                 kafscmd_die = 1;
 374                 wake_up(&kafscmd_sleepq);
 375                 wait_for_completion(&kafscmd_dead);
 376
 377                 /* dispose of any calls waiting for attention */
 378                 spin_lock(&kafscmd_attention_lock);
 379                 while (!list_empty(&kafscmd_attention_list)) {
 380                         call = list_entry(kafscmd_attention_list.next,
 381                                           struct rxrpc_call,
 382                                           app_attn_link);
 383
 384                         list_del_init(&call->app_attn_link);
 385                         spin_unlock(&kafscmd_attention_lock);
 386
 387                         rxrpc_put_call(call);
 388
 389                         spin_lock(&kafscmd_attention_lock);
 390                 }
 391                 spin_unlock(&kafscmd_attention_lock);
 392
 393                 afs_kafstimod_del_timer(&afs_mntpt_expiry_timer);
 394         }
 395
 396         up_write(&afscm_sem);
 397
 398 } /* end afscm_stop() */
 399
 400 /*****************************************************************************/
 401 /*
 402  * handle the fileserver breaking a set of callbacks
 403  */
 404 static void _SRXAFSCM_CallBack(struct rxrpc_call *call)
 405 {
 406         struct afs_server *server;
 407         size_t count, qty, tmp;
 408         int ret = 0, removed;
 409
 410         _enter("%p{acs=%s}", call, rxrpc_call_states[call->app_call_state]);
 411
 412         server = afs_server_get_from_peer(call->conn->peer);
 413
 414         switch (call->app_call_state) {
 415                 /* we've received the last packet
 416                  * - drain all the data from the call and send the reply
 417                  */
 418         case RXRPC_CSTATE_SRVR_GOT_ARGS:
 419                 ret = -EBADMSG;
 420                 qty = call->app_ready_qty;
 421                 if (qty < 8 || qty > 50 * (6 * 4) + 8)
 422                         break;
 423
 424                 {
 425                         struct afs_callback *cb, *pcb;
 426                         int loop;
 427                         __be32 *fp, *bp;
 428
 429                         fp = rxrpc_call_alloc_scratch(call, qty);
 430
 431                         /* drag the entire argument block out to the scratch
 432                          * space */
 433                         ret = rxrpc_call_read_data(call, fp, qty, 0);
 434                         if (ret < 0)
 435                                 break;
 436
 437                         /* and unmarshall the parameter block */
 438                         ret = -EBADMSG;
 439                         count = ntohl(*fp++);
 440                         if (count>AFSCBMAX ||
 441                             (count * (3 * 4) + 8 != qty &&
 442                              count * (6 * 4) + 8 != qty))
 443                                 break;
 444
 445                         bp = fp + count*3;
 446                         tmp = ntohl(*bp++);
 447                         if (tmp > 0 && tmp != count)
 448                                 break;
 449                         if (tmp == 0)
 450                                 bp = NULL;
 451
 452                         pcb = cb = rxrpc_call_alloc_scratch_s(
 453                                 call, struct afs_callback);
 454
 455                         for (loop = count - 1; loop >= 0; loop--) {
 456                                 pcb->fid.vid    = ntohl(*fp++);
 457                                 pcb->fid.vnode  = ntohl(*fp++);
 458                                 pcb->fid.unique = ntohl(*fp++);
 459                                 if (bp) {
 460                                         pcb->version    = ntohl(*bp++);
 461                                         pcb->expiry     = ntohl(*bp++);
 462                                         pcb->type       = ntohl(*bp++);
 463                                 }
 464                                 else {
 465                                         pcb->version    = 0;
 466                                         pcb->expiry     = 0;
 467                                         pcb->type       = AFSCM_CB_UNTYPED;
 468                                 }
 469                                 pcb++;
 470                         }
 471
 472                         /* invoke the actual service routine */
 473                         ret = SRXAFSCM_CallBack(server, count, cb);
 474                         if (ret < 0)
 475                                 break;
 476                 }
 477
 478                 /* send the reply */
 479                 ret = rxrpc_call_write_data(call, 0, NULL, RXRPC_LAST_PACKET,
 480                                             GFP_KERNEL, 0, &count);
 481                 if (ret < 0)
 482                         break;
 483                 break;
 484
 485                 /* operation complete */
 486         case RXRPC_CSTATE_COMPLETE:
 487                 call->app_user = NULL;
 488                 removed = 0;
 489                 spin_lock(&afscm_calls_lock);
 490                 if (!list_empty(&call->app_link)) {
 491                         list_del_init(&call->app_link);
 492                         removed = 1;
 493                 }
 494                 spin_unlock(&afscm_calls_lock);
 495
 496                 if (removed)
 497                         rxrpc_put_call(call);
 498                 break;
 499
 500                 /* operation terminated on error */
 501         case RXRPC_CSTATE_ERROR:
 502                 call->app_user = NULL;
 503                 break;
 504
 505         default:
 506                 break;
 507         }
 508
 509         if (ret < 0)
 510                 rxrpc_call_abort(call, ret);
 511
 512         afs_put_server(server);
 513
 514         _leave(" = %d", ret);
 515
 516 } /* end _SRXAFSCM_CallBack() */
 517
 518 /*****************************************************************************/
 519 /*
 520  * handle the fileserver asking us to initialise our callback state
 521  */
 522 static void _SRXAFSCM_InitCallBackState(struct rxrpc_call *call)
 523 {
 524         struct afs_server *server;
 525         size_t count;
 526         int ret = 0, removed;
 527
 528         _enter("%p{acs=%s}", call, rxrpc_call_states[call->app_call_state]);
 529
 530         server = afs_server_get_from_peer(call->conn->peer);
 531
 532         switch (call->app_call_state) {
 533                 /* we've received the last packet - drain all the data from the
 534                  * call */
 535         case RXRPC_CSTATE_SRVR_GOT_ARGS:
 536                 /* shouldn't be any args */
 537                 ret = -EBADMSG;
 538                 break;
 539
 540                 /* send the reply when asked for it */
 541         case RXRPC_CSTATE_SRVR_SND_REPLY:
 542                 /* invoke the actual service routine */
 543                 ret = SRXAFSCM_InitCallBackState(server);
 544                 if (ret < 0)
 545                         break;
 546
 547                 ret = rxrpc_call_write_data(call, 0, NULL, RXRPC_LAST_PACKET,
 548                                             GFP_KERNEL, 0, &count);
 549                 if (ret < 0)
 550                         break;
 551                 break;
 552
 553                 /* operation complete */
 554         case RXRPC_CSTATE_COMPLETE:
 555                 call->app_user = NULL;
 556                 removed = 0;
 557                 spin_lock(&afscm_calls_lock);
 558                 if (!list_empty(&call->app_link)) {
 559                         list_del_init(&call->app_link);
 560                         removed = 1;
 561                 }
 562                 spin_unlock(&afscm_calls_lock);
 563
 564                 if (removed)
 565                         rxrpc_put_call(call);
 566                 break;
 567
 568                 /* operation terminated on error */
 569         case RXRPC_CSTATE_ERROR:
 570                 call->app_user = NULL;
 571                 break;
 572
 573         default:
 574                 break;
 575         }
 576
 577         if (ret < 0)
 578                 rxrpc_call_abort(call, ret);
 579
 580         afs_put_server(server);
 581
 582         _leave(" = %d", ret);
 583
 584 } /* end _SRXAFSCM_InitCallBackState() */
 585
 586 /*****************************************************************************/
 587 /*
 588  * handle a probe from a fileserver
 589  */
 590 static void _SRXAFSCM_Probe(struct rxrpc_call *call)
 591 {
 592         struct afs_server *server;
 593         size_t count;
 594         int ret = 0, removed;
 595
 596         _enter("%p{acs=%s}", call, rxrpc_call_states[call->app_call_state]);
 597
 598         server = afs_server_get_from_peer(call->conn->peer);
 599
 600         switch (call->app_call_state) {
 601                 /* we've received the last packet - drain all the data from the
 602                  * call */
 603         case RXRPC_CSTATE_SRVR_GOT_ARGS:
 604                 /* shouldn't be any args */
 605                 ret = -EBADMSG;
 606                 break;
 607
 608                 /* send the reply when asked for it */
 609         case RXRPC_CSTATE_SRVR_SND_REPLY:
 610                 /* invoke the actual service routine */
 611                 ret = SRXAFSCM_Probe(server);
 612                 if (ret < 0)
 613                         break;
 614
 615                 ret = rxrpc_call_write_data(call, 0, NULL, RXRPC_LAST_PACKET,
 616                                             GFP_KERNEL, 0, &count);
 617                 if (ret < 0)
 618                         break;
 619                 break;
 620
 621                 /* operation complete */
 622         case RXRPC_CSTATE_COMPLETE:
 623                 call->app_user = NULL;
 624                 removed = 0;
 625                 spin_lock(&afscm_calls_lock);
 626                 if (!list_empty(&call->app_link)) {
 627                         list_del_init(&call->app_link);
 628                         removed = 1;
 629                 }
 630                 spin_unlock(&afscm_calls_lock);
 631
 632                 if (removed)
 633                         rxrpc_put_call(call);
 634                 break;
 635
 636                 /* operation terminated on error */
 637         case RXRPC_CSTATE_ERROR:
 638                 call->app_user = NULL;
 639                 break;
 640
 641         default:
 642                 break;
 643         }
 644
 645         if (ret < 0)
 646                 rxrpc_call_abort(call, ret);
 647
 648         afs_put_server(server);
 649
 650         _leave(" = %d", ret);
 651
 652 } /* end _SRXAFSCM_Probe() */