fs/afs/cmservice.c

   1 /* 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  * AFS Cache Manager kernel thread
 111  */
 112 static int kafscmd(void *arg)
 113 {
 114         DECLARE_WAITQUEUE(myself, current);
 115
 116         struct rxrpc_call *call;
 117         _SRXAFSCM_xxxx_t func;
 118         int die;
 119
 120         printk(KERN_INFO "kAFS: Started kafscmd %d\n", current->pid);
 121
 122         daemonize("kafscmd");
 123
 124         complete(&kafscmd_alive);
 125
 126         /* loop around looking for things to attend to */
 127         do {
 128                 if (list_empty(&kafscmd_attention_list)) {
 129                         set_current_state(TASK_INTERRUPTIBLE);
 130                         add_wait_queue(&kafscmd_sleepq, &myself);
 131
 132                         for (;;) {
 133                                 set_current_state(TASK_INTERRUPTIBLE);
 134                                 if (!list_empty(&kafscmd_attention_list) ||
 135                                     signal_pending(current) ||
 136                                     kafscmd_die)
 137                                         break;
 138
 139                                 schedule();
 140                         }
 141
 142                         remove_wait_queue(&kafscmd_sleepq, &myself);
 143                         set_current_state(TASK_RUNNING);
 144                 }
 145
 146                 die = kafscmd_die;
 147
 148                 /* dequeue the next call requiring attention */
 149                 call = NULL;
 150                 spin_lock(&kafscmd_attention_lock);
 151
 152                 if (!list_empty(&kafscmd_attention_list)) {
 153                         call = list_entry(kafscmd_attention_list.next,
 154                                           struct rxrpc_call,
 155                                           app_attn_link);
 156                         list_del_init(&call->app_attn_link);
 157                         die = 0;
 158                 }
 159
 160                 spin_unlock(&kafscmd_attention_lock);
 161
 162                 if (call) {
 163                         /* act upon it */
 164                         _debug("@@@ Begin Attend Call %p", call);
 165
 166                         func = call->app_user;
 167                         if (func)
 168                                 func(call);
 169
 170                         rxrpc_put_call(call);
 171
 172                         _debug("@@@ End Attend Call %p", call);
 173                 }
 174
 175         } while(!die);
 176
 177         /* and that's all */
 178         complete_and_exit(&kafscmd_dead, 0);
 179 }
 180
 181 /*
 182  * handle a call coming in to the cache manager
 183  * - if I want to keep the call, I must increment its usage count
 184  * - the return value will be negated and passed back in an abort packet if
 185  *   non-zero
 186  * - serialised by virtue of there only being one krxiod
 187  */
 188 static int afscm_new_call(struct rxrpc_call *call)
 189 {
 190         _enter("%p{cid=%u u=%d}",
 191                call, ntohl(call->call_id), atomic_read(&call->usage));
 192
 193         rxrpc_get_call(call);
 194
 195         /* add to my current call list */
 196         spin_lock(&afscm_calls_lock);
 197         list_add(&call->app_link,&afscm_calls);
 198         spin_unlock(&afscm_calls_lock);
 199
 200         _leave(" = 0");
 201         return 0;
 202 }
 203
 204 /*
 205  * queue on the kafscmd queue for attention
 206  */
 207 static void afscm_attention(struct rxrpc_call *call)
 208 {
 209         _enter("%p{cid=%u u=%d}",
 210                call, ntohl(call->call_id), atomic_read(&call->usage));
 211
 212         spin_lock(&kafscmd_attention_lock);
 213
 214         if (list_empty(&call->app_attn_link)) {
 215                 list_add_tail(&call->app_attn_link, &kafscmd_attention_list);
 216                 rxrpc_get_call(call);
 217         }
 218
 219         spin_unlock(&kafscmd_attention_lock);
 220
 221         wake_up(&kafscmd_sleepq);
 222
 223         _leave(" {u=%d}", atomic_read(&call->usage));
 224 }
 225
 226 /*
 227  * handle my call being aborted
 228  * - clean up, dequeue and put my ref to the call
 229  */
 230 static void afscm_error(struct rxrpc_call *call)
 231 {
 232         int removed;
 233
 234         _enter("%p{est=%s ac=%u er=%d}",
 235                call,
 236                rxrpc_call_error_states[call->app_err_state],
 237                call->app_abort_code,
 238                call->app_errno);
 239
 240         spin_lock(&kafscmd_attention_lock);
 241
 242         if (list_empty(&call->app_attn_link)) {
 243                 list_add_tail(&call->app_attn_link, &kafscmd_attention_list);
 244                 rxrpc_get_call(call);
 245         }
 246
 247         spin_unlock(&kafscmd_attention_lock);
 248
 249         removed = 0;
 250         spin_lock(&afscm_calls_lock);
 251         if (!list_empty(&call->app_link)) {
 252                 list_del_init(&call->app_link);
 253                 removed = 1;
 254         }
 255         spin_unlock(&afscm_calls_lock);
 256
 257         if (removed)
 258                 rxrpc_put_call(call);
 259
 260         wake_up(&kafscmd_sleepq);
 261
 262         _leave("");
 263 }
 264
 265 /*
 266  * map afs abort codes to/from Linux error codes
 267  * - called with call->lock held
 268  */
 269 static void afscm_aemap(struct rxrpc_call *call)
 270 {
 271         switch (call->app_err_state) {
 272         case RXRPC_ESTATE_LOCAL_ABORT:
 273                 call->app_abort_code = -call->app_errno;
 274                 break;
 275         case RXRPC_ESTATE_PEER_ABORT:
 276                 call->app_errno = -ECONNABORTED;
 277                 break;
 278         default:
 279                 break;
 280         }
 281 }
 282
 283 /*
 284  * start the cache manager service if not already started
 285  */
 286 int afscm_start(void)
 287 {
 288         int ret;
 289
 290         down_write(&afscm_sem);
 291         if (!afscm_usage) {
 292                 ret = kernel_thread(kafscmd, NULL, 0);
 293                 if (ret < 0)
 294                         goto out;
 295
 296                 wait_for_completion(&kafscmd_alive);
 297
 298                 ret = rxrpc_add_service(afs_transport, &AFSCM_service);
 299                 if (ret < 0)
 300                         goto kill;
 301
 302                 afs_kafstimod_add_timer(&afs_mntpt_expiry_timer,
 303                                         afs_mntpt_expiry_timeout * HZ);
 304         }
 305
 306         afscm_usage++;
 307         up_write(&afscm_sem);
 308
 309         return 0;
 310
 311 kill:
 312         kafscmd_die = 1;
 313         wake_up(&kafscmd_sleepq);
 314         wait_for_completion(&kafscmd_dead);
 315
 316 out:
 317         up_write(&afscm_sem);
 318         return ret;
 319 }
 320
 321 /*
 322  * stop the cache manager service
 323  */
 324 void afscm_stop(void)
 325 {
 326         struct rxrpc_call *call;
 327
 328         down_write(&afscm_sem);
 329
 330         BUG_ON(afscm_usage == 0);
 331         afscm_usage--;
 332
 333         if (afscm_usage == 0) {
 334                 /* don't want more incoming calls */
 335                 rxrpc_del_service(afs_transport, &AFSCM_service);
 336
 337                 /* abort any calls I've still got open (the afscm_error() will
 338                  * dequeue them) */
 339                 spin_lock(&afscm_calls_lock);
 340                 while (!list_empty(&afscm_calls)) {
 341                         call = list_entry(afscm_calls.next,
 342                                           struct rxrpc_call,
 343                                           app_link);
 344
 345                         list_del_init(&call->app_link);
 346                         rxrpc_get_call(call);
 347                         spin_unlock(&afscm_calls_lock);
 348
 349                         rxrpc_call_abort(call, -ESRCH); /* abort, dequeue and
 350                                                          * put */
 351
 352                         _debug("nuking active call %08x.%d",
 353                                ntohl(call->conn->conn_id),
 354                                ntohl(call->call_id));
 355                         rxrpc_put_call(call);
 356                         rxrpc_put_call(call);
 357
 358                         spin_lock(&afscm_calls_lock);
 359                 }
 360                 spin_unlock(&afscm_calls_lock);
 361
 362                 /* get rid of my daemon */
 363                 kafscmd_die = 1;
 364                 wake_up(&kafscmd_sleepq);
 365                 wait_for_completion(&kafscmd_dead);
 366
 367                 /* dispose of any calls waiting for attention */
 368                 spin_lock(&kafscmd_attention_lock);
 369                 while (!list_empty(&kafscmd_attention_list)) {
 370                         call = list_entry(kafscmd_attention_list.next,
 371                                           struct rxrpc_call,
 372                                           app_attn_link);
 373
 374                         list_del_init(&call->app_attn_link);
 375                         spin_unlock(&kafscmd_attention_lock);
 376
 377                         rxrpc_put_call(call);
 378
 379                         spin_lock(&kafscmd_attention_lock);
 380                 }
 381                 spin_unlock(&kafscmd_attention_lock);
 382
 383                 afs_kafstimod_del_timer(&afs_mntpt_expiry_timer);
 384         }
 385
 386         up_write(&afscm_sem);
 387 }
 388
 389 /*
 390  * handle the fileserver breaking a set of callbacks
 391  */
 392 static void _SRXAFSCM_CallBack(struct rxrpc_call *call)
 393 {
 394         struct afs_server *server;
 395         size_t count, qty, tmp;
 396         int ret = 0, removed;
 397
 398         _enter("%p{acs=%s}", call, rxrpc_call_states[call->app_call_state]);
 399
 400         server = afs_server_get_from_peer(call->conn->peer);
 401
 402         switch (call->app_call_state) {
 403                 /* we've received the last packet
 404                  * - drain all the data from the call and send the reply
 405                  */
 406         case RXRPC_CSTATE_SRVR_GOT_ARGS:
 407                 ret = -EBADMSG;
 408                 qty = call->app_ready_qty;
 409                 if (qty < 8 || qty > 50 * (6 * 4) + 8)
 410                         break;
 411
 412                 {
 413                         struct afs_callback *cb, *pcb;
 414                         int loop;
 415                         __be32 *fp, *bp;
 416
 417                         fp = rxrpc_call_alloc_scratch(call, qty);
 418
 419                         /* drag the entire argument block out to the scratch
 420                          * space */
 421                         ret = rxrpc_call_read_data(call, fp, qty, 0);
 422                         if (ret < 0)
 423                                 break;
 424
 425                         /* and unmarshall the parameter block */
 426                         ret = -EBADMSG;
 427                         count = ntohl(*fp++);
 428                         if (count>AFSCBMAX ||
 429                             (count * (3 * 4) + 8 != qty &&
 430                              count * (6 * 4) + 8 != qty))
 431                                 break;
 432
 433                         bp = fp + count*3;
 434                         tmp = ntohl(*bp++);
 435                         if (tmp > 0 && tmp != count)
 436                                 break;
 437                         if (tmp == 0)
 438                                 bp = NULL;
 439
 440                         pcb = cb = rxrpc_call_alloc_scratch_s(
 441                                 call, struct afs_callback);
 442
 443                         for (loop = count - 1; loop >= 0; loop--) {
 444                                 pcb->fid.vid    = ntohl(*fp++);
 445                                 pcb->fid.vnode  = ntohl(*fp++);
 446                                 pcb->fid.unique = ntohl(*fp++);
 447                                 if (bp) {
 448                                         pcb->version    = ntohl(*bp++);
 449                                         pcb->expiry     = ntohl(*bp++);
 450                                         pcb->type       = ntohl(*bp++);
 451                                 } else {
 452                                         pcb->version    = 0;
 453                                         pcb->expiry     = 0;
 454                                         pcb->type       = AFSCM_CB_UNTYPED;
 455                                 }
 456                                 pcb++;
 457                         }
 458
 459                         /* invoke the actual service routine */
 460                         ret = SRXAFSCM_CallBack(server, count, cb);
 461                         if (ret < 0)
 462                                 break;
 463                 }
 464
 465                 /* send the reply */
 466                 ret = rxrpc_call_write_data(call, 0, NULL, RXRPC_LAST_PACKET,
 467                                             GFP_KERNEL, 0, &count);
 468                 if (ret < 0)
 469                         break;
 470                 break;
 471
 472                 /* operation complete */
 473         case RXRPC_CSTATE_COMPLETE:
 474                 call->app_user = NULL;
 475                 removed = 0;
 476                 spin_lock(&afscm_calls_lock);
 477                 if (!list_empty(&call->app_link)) {
 478                         list_del_init(&call->app_link);
 479                         removed = 1;
 480                 }
 481                 spin_unlock(&afscm_calls_lock);
 482
 483                 if (removed)
 484                         rxrpc_put_call(call);
 485                 break;
 486
 487                 /* operation terminated on error */
 488         case RXRPC_CSTATE_ERROR:
 489                 call->app_user = NULL;
 490                 break;
 491
 492         default:
 493                 break;
 494         }
 495
 496         if (ret < 0)
 497                 rxrpc_call_abort(call, ret);
 498
 499         afs_put_server(server);
 500
 501         _leave(" = %d", ret);
 502 }
 503
 504 /*
 505  * handle the fileserver asking us to initialise our callback state
 506  */
 507 static void _SRXAFSCM_InitCallBackState(struct rxrpc_call *call)
 508 {
 509         struct afs_server *server;
 510         size_t count;
 511         int ret = 0, removed;
 512
 513         _enter("%p{acs=%s}", call, rxrpc_call_states[call->app_call_state]);
 514
 515         server = afs_server_get_from_peer(call->conn->peer);
 516
 517         switch (call->app_call_state) {
 518                 /* we've received the last packet - drain all the data from the
 519                  * call */
 520         case RXRPC_CSTATE_SRVR_GOT_ARGS:
 521                 /* shouldn't be any args */
 522                 ret = -EBADMSG;
 523                 break;
 524
 525                 /* send the reply when asked for it */
 526         case RXRPC_CSTATE_SRVR_SND_REPLY:
 527                 /* invoke the actual service routine */
 528                 ret = SRXAFSCM_InitCallBackState(server);
 529                 if (ret < 0)
 530                         break;
 531
 532                 ret = rxrpc_call_write_data(call, 0, NULL, RXRPC_LAST_PACKET,
 533                                             GFP_KERNEL, 0, &count);
 534                 if (ret < 0)
 535                         break;
 536                 break;
 537
 538                 /* operation complete */
 539         case RXRPC_CSTATE_COMPLETE:
 540                 call->app_user = NULL;
 541                 removed = 0;
 542                 spin_lock(&afscm_calls_lock);
 543                 if (!list_empty(&call->app_link)) {
 544                         list_del_init(&call->app_link);
 545                         removed = 1;
 546                 }
 547                 spin_unlock(&afscm_calls_lock);
 548
 549                 if (removed)
 550                         rxrpc_put_call(call);
 551                 break;
 552
 553                 /* operation terminated on error */
 554         case RXRPC_CSTATE_ERROR:
 555                 call->app_user = NULL;
 556                 break;
 557
 558         default:
 559                 break;
 560         }
 561
 562         if (ret < 0)
 563                 rxrpc_call_abort(call, ret);
 564
 565         afs_put_server(server);
 566
 567         _leave(" = %d", ret);
 568 }
 569
 570 /*
 571  * handle a probe from a fileserver
 572  */
 573 static void _SRXAFSCM_Probe(struct rxrpc_call *call)
 574 {
 575         struct afs_server *server;
 576         size_t count;
 577         int ret = 0, removed;
 578
 579         _enter("%p{acs=%s}", call, rxrpc_call_states[call->app_call_state]);
 580
 581         server = afs_server_get_from_peer(call->conn->peer);
 582
 583         switch (call->app_call_state) {
 584                 /* we've received the last packet - drain all the data from the
 585                  * call */
 586         case RXRPC_CSTATE_SRVR_GOT_ARGS:
 587                 /* shouldn't be any args */
 588                 ret = -EBADMSG;
 589                 break;
 590
 591                 /* send the reply when asked for it */
 592         case RXRPC_CSTATE_SRVR_SND_REPLY:
 593                 /* invoke the actual service routine */
 594                 ret = SRXAFSCM_Probe(server);
 595                 if (ret < 0)
 596                         break;
 597
 598                 ret = rxrpc_call_write_data(call, 0, NULL, RXRPC_LAST_PACKET,
 599                                             GFP_KERNEL, 0, &count);
 600                 if (ret < 0)
 601                         break;
 602                 break;
 603
 604                 /* operation complete */
 605         case RXRPC_CSTATE_COMPLETE:
 606                 call->app_user = NULL;
 607                 removed = 0;
 608                 spin_lock(&afscm_calls_lock);
 609                 if (!list_empty(&call->app_link)) {
 610                         list_del_init(&call->app_link);
 611                         removed = 1;
 612                 }
 613                 spin_unlock(&afscm_calls_lock);
 614
 615                 if (removed)
 616                         rxrpc_put_call(call);
 617                 break;
 618
 619                 /* operation terminated on error */
 620         case RXRPC_CSTATE_ERROR:
 621                 call->app_user = NULL;
 622                 break;
 623
 624         default:
 625                 break;
 626         }
 627
 628         if (ret < 0)
 629                 rxrpc_call_abort(call, ret);
 630
 631         afs_put_server(server);
 632
 633         _leave(" = %d", ret);
 634 }