uspace/lib/fs/libfs.c

   1 /*
   2  * Copyright (c) 2009 Jakub Jermar
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup libfs
  30  * @{
  31  */
  32 /**
  33  * @file
  34  * Glue code which is common to all FS implementations.
  35  */
  36
  37 #include "libfs.h"
  38 #include <macros.h>
  39 #include <errno.h>
  40 #include <async.h>
  41 #include <as.h>
  42 #include <assert.h>
  43 #include <dirent.h>
  44 #include <mem.h>
  45 #include <str.h>
  46 #include <stdlib.h>
  47 #include <fibril_synch.h>
  48 #include <ipc/vfs.h>
  49 #include <vfs/vfs.h>
  50
  51 #define on_error(rc, action) \
  52         do { \
  53                 if ((rc) != EOK) \
  54                         action; \
  55         } while (0)
  56
  57 #define combine_rc(rc1, rc2) \
  58         ((rc1) == EOK ? (rc2) : (rc1))
  59
  60 #define answer_and_return(call, rc) \
  61         do { \
  62                 async_answer_0((call), (rc)); \
  63                 return; \
  64         } while (0)
  65
  66 static fs_reg_t reg;
  67
  68 static vfs_out_ops_t *vfs_out_ops = NULL;
  69 static libfs_ops_t *libfs_ops = NULL;
  70
  71 static char fs_name[FS_NAME_MAXLEN + 1];
  72
  73 static void libfs_link(libfs_ops_t *, fs_handle_t, ipc_call_t *);
  74 static void libfs_lookup(libfs_ops_t *, fs_handle_t, ipc_call_t *);
  75 static void libfs_stat(libfs_ops_t *, fs_handle_t, ipc_call_t *);
  76 static void libfs_open_node(libfs_ops_t *, fs_handle_t, ipc_call_t *);
  77 static void libfs_statfs(libfs_ops_t *, fs_handle_t, ipc_call_t *);
  78
  79 static void vfs_out_fsprobe(ipc_call_t *req)
  80 {
  81         service_id_t service_id = (service_id_t) ipc_get_arg1(req);
  82         errno_t rc;
  83         vfs_fs_probe_info_t info;
  84
  85         ipc_call_t call;
  86         size_t size;
  87         if ((!async_data_read_receive(&call, &size)) ||
  88             (size != sizeof(info))) {
  89                 async_answer_0(&call, EIO);
  90                 async_answer_0(req, EIO);
  91                 return;
  92         }
  93
  94         memset(&info, 0, sizeof(info));
  95         rc = vfs_out_ops->fsprobe(service_id, &info);
  96         if (rc != EOK) {
  97                 async_answer_0(&call, EIO);
  98                 async_answer_0(req, rc);
  99                 return;
 100         }
 101
 102         async_data_read_finalize(&call, &info, sizeof(info));
 103         async_answer_0(req, EOK);
 104 }
 105
 106 static void vfs_out_mounted(ipc_call_t *req)
 107 {
 108         service_id_t service_id = (service_id_t) ipc_get_arg1(req);
 109         char *opts;
 110         errno_t rc;
 111
 112         /* Accept the mount options. */
 113         rc = async_data_write_accept((void **) &opts, true, 0, 0, 0, NULL);
 114         if (rc != EOK) {
 115                 async_answer_0(req, rc);
 116                 return;
 117         }
 118
 119         fs_index_t index;
 120         aoff64_t size;
 121         rc = vfs_out_ops->mounted(service_id, opts, &index, &size);
 122
 123         if (rc == EOK) {
 124                 async_answer_3(req, EOK, index, LOWER32(size),
 125                     UPPER32(size));
 126         } else
 127                 async_answer_0(req, rc);
 128
 129         free(opts);
 130 }
 131
 132 static void vfs_out_unmounted(ipc_call_t *req)
 133 {
 134         service_id_t service_id = (service_id_t) ipc_get_arg1(req);
 135         errno_t rc;
 136
 137         rc = vfs_out_ops->unmounted(service_id);
 138
 139         async_answer_0(req, rc);
 140 }
 141
 142 static void vfs_out_link(ipc_call_t *req)
 143 {
 144         libfs_link(libfs_ops, reg.fs_handle, req);
 145 }
 146
 147 static void vfs_out_lookup(ipc_call_t *req)
 148 {
 149         libfs_lookup(libfs_ops, reg.fs_handle, req);
 150 }
 151
 152 static void vfs_out_read(ipc_call_t *req)
 153 {
 154         service_id_t service_id = (service_id_t) ipc_get_arg1(req);
 155         fs_index_t index = (fs_index_t) ipc_get_arg2(req);
 156         aoff64_t pos = (aoff64_t) MERGE_LOUP32(ipc_get_arg3(req),
 157             ipc_get_arg4(req));
 158         size_t rbytes;
 159         errno_t rc;
 160
 161         rc = vfs_out_ops->read(service_id, index, pos, &rbytes);
 162
 163         if (rc == EOK)
 164                 async_answer_1(req, EOK, rbytes);
 165         else
 166                 async_answer_0(req, rc);
 167 }
 168
 169 static void vfs_out_write(ipc_call_t *req)
 170 {
 171         service_id_t service_id = (service_id_t) ipc_get_arg1(req);
 172         fs_index_t index = (fs_index_t) ipc_get_arg2(req);
 173         aoff64_t pos = (aoff64_t) MERGE_LOUP32(ipc_get_arg3(req),
 174             ipc_get_arg4(req));
 175         size_t wbytes;
 176         aoff64_t nsize;
 177         errno_t rc;
 178
 179         rc = vfs_out_ops->write(service_id, index, pos, &wbytes, &nsize);
 180
 181         if (rc == EOK) {
 182                 async_answer_3(req, EOK, wbytes, LOWER32(nsize),
 183                     UPPER32(nsize));
 184         } else
 185                 async_answer_0(req, rc);
 186 }
 187
 188 static void vfs_out_truncate(ipc_call_t *req)
 189 {
 190         service_id_t service_id = (service_id_t) ipc_get_arg1(req);
 191         fs_index_t index = (fs_index_t) ipc_get_arg2(req);
 192         aoff64_t size = (aoff64_t) MERGE_LOUP32(ipc_get_arg3(req),
 193             ipc_get_arg4(req));
 194         errno_t rc;
 195
 196         rc = vfs_out_ops->truncate(service_id, index, size);
 197
 198         async_answer_0(req, rc);
 199 }
 200
 201 static void vfs_out_close(ipc_call_t *req)
 202 {
 203         service_id_t service_id = (service_id_t) ipc_get_arg1(req);
 204         fs_index_t index = (fs_index_t) ipc_get_arg2(req);
 205         errno_t rc;
 206
 207         rc = vfs_out_ops->close(service_id, index);
 208
 209         async_answer_0(req, rc);
 210 }
 211
 212 static void vfs_out_destroy(ipc_call_t *req)
 213 {
 214         service_id_t service_id = (service_id_t) ipc_get_arg1(req);
 215         fs_index_t index = (fs_index_t) ipc_get_arg2(req);
 216
 217         errno_t rc;
 218         fs_node_t *node = NULL;
 219         rc = libfs_ops->node_get(&node, service_id, index);
 220         if (rc == EOK && node != NULL) {
 221                 bool destroy = (libfs_ops->lnkcnt_get(node) == 0);
 222                 libfs_ops->node_put(node);
 223                 if (destroy)
 224                         rc = vfs_out_ops->destroy(service_id, index);
 225         }
 226         async_answer_0(req, rc);
 227 }
 228
 229 static void vfs_out_open_node(ipc_call_t *req)
 230 {
 231         libfs_open_node(libfs_ops, reg.fs_handle, req);
 232 }
 233
 234 static void vfs_out_stat(ipc_call_t *req)
 235 {
 236         libfs_stat(libfs_ops, reg.fs_handle, req);
 237 }
 238
 239 static void vfs_out_sync(ipc_call_t *req)
 240 {
 241         service_id_t service_id = (service_id_t) ipc_get_arg1(req);
 242         fs_index_t index = (fs_index_t) ipc_get_arg2(req);
 243         errno_t rc;
 244
 245         rc = vfs_out_ops->sync(service_id, index);
 246
 247         async_answer_0(req, rc);
 248 }
 249
 250 static void vfs_out_statfs(ipc_call_t *req)
 251 {
 252         libfs_statfs(libfs_ops, reg.fs_handle, req);
 253 }
 254
 255 static void vfs_out_is_empty(ipc_call_t *req)
 256 {
 257         service_id_t service_id = (service_id_t) ipc_get_arg1(req);
 258         fs_index_t index = (fs_index_t) ipc_get_arg2(req);
 259         errno_t rc;
 260
 261         fs_node_t *node = NULL;
 262         rc = libfs_ops->node_get(&node, service_id, index);
 263         if (rc != EOK)
 264                 async_answer_0(req, rc);
 265         if (node == NULL)
 266                 async_answer_0(req, EINVAL);
 267
 268         bool children = false;
 269         rc = libfs_ops->has_children(&children, node);
 270         libfs_ops->node_put(node);
 271
 272         if (rc != EOK)
 273                 async_answer_0(req, rc);
 274         async_answer_0(req, children ? ENOTEMPTY : EOK);
 275 }
 276
 277 static void vfs_connection(ipc_call_t *icall, void *arg)
 278 {
 279         if (icall->cap_handle) {
 280                 /*
 281                  * This only happens for connections opened by
 282                  * IPC_M_CONNECT_ME_TO calls as opposed to callback connections
 283                  * created by IPC_M_CONNECT_TO_ME.
 284                  */
 285                 async_accept_0(icall);
 286         }
 287
 288         while (true) {
 289                 ipc_call_t call;
 290                 async_get_call(&call);
 291
 292                 if (!ipc_get_imethod(&call)) {
 293                         async_answer_0(&call, EOK);
 294                         return;
 295                 }
 296
 297                 switch (ipc_get_imethod(&call)) {
 298                 case VFS_OUT_FSPROBE:
 299                         vfs_out_fsprobe(&call);
 300                         break;
 301                 case VFS_OUT_MOUNTED:
 302                         vfs_out_mounted(&call);
 303                         break;
 304                 case VFS_OUT_UNMOUNTED:
 305                         vfs_out_unmounted(&call);
 306                         break;
 307                 case VFS_OUT_LINK:
 308                         vfs_out_link(&call);
 309                         break;
 310                 case VFS_OUT_LOOKUP:
 311                         vfs_out_lookup(&call);
 312                         break;
 313                 case VFS_OUT_READ:
 314                         vfs_out_read(&call);
 315                         break;
 316                 case VFS_OUT_WRITE:
 317                         vfs_out_write(&call);
 318                         break;
 319                 case VFS_OUT_TRUNCATE:
 320                         vfs_out_truncate(&call);
 321                         break;
 322                 case VFS_OUT_CLOSE:
 323                         vfs_out_close(&call);
 324                         break;
 325                 case VFS_OUT_DESTROY:
 326                         vfs_out_destroy(&call);
 327                         break;
 328                 case VFS_OUT_OPEN_NODE:
 329                         vfs_out_open_node(&call);
 330                         break;
 331                 case VFS_OUT_STAT:
 332                         vfs_out_stat(&call);
 333                         break;
 334                 case VFS_OUT_SYNC:
 335                         vfs_out_sync(&call);
 336                         break;
 337                 case VFS_OUT_STATFS:
 338                         vfs_out_statfs(&call);
 339                         break;
 340                 case VFS_OUT_IS_EMPTY:
 341                         vfs_out_is_empty(&call);
 342                         break;
 343                 default:
 344                         async_answer_0(&call, ENOTSUP);
 345                         break;
 346                 }
 347         }
 348 }
 349
 350 /** Register file system server.
 351  *
 352  * This function abstracts away the tedious registration protocol from
 353  * file system implementations and lets them to reuse this registration glue
 354  * code.
 355  *
 356  * @param sess Session for communication with VFS.
 357  * @param info VFS info structure supplied by the file system
 358  *             implementation.
 359  * @param vops Address of the vfs_out_ops_t structure.
 360  * @param lops Address of the libfs_ops_t structure.
 361  *
 362  * @return EOK on success or a non-zero error code on errror.
 363  *
 364  */
 365 errno_t fs_register(async_sess_t *sess, vfs_info_t *info, vfs_out_ops_t *vops,
 366     libfs_ops_t *lops)
 367 {
 368         /*
 369          * Tell VFS that we are here and want to get registered.
 370          * We use the async framework because VFS will answer the request
 371          * out-of-order, when it knows that the operation succeeded or failed.
 372          */
 373
 374         async_exch_t *exch = async_exchange_begin(sess);
 375
 376         ipc_call_t answer;
 377         aid_t req = async_send_0(exch, VFS_IN_REGISTER, &answer);
 378
 379         /*
 380          * Send our VFS info structure to VFS.
 381          */
 382         errno_t rc = async_data_write_start(exch, info, sizeof(*info));
 383
 384         if (rc != EOK) {
 385                 async_exchange_end(exch);
 386                 async_forget(req);
 387                 return rc;
 388         }
 389
 390         /*
 391          * Set VFS_OUT and libfs operations.
 392          */
 393         vfs_out_ops = vops;
 394         libfs_ops = lops;
 395
 396         str_cpy(fs_name, sizeof(fs_name), info->name);
 397
 398         /*
 399          * Ask VFS for callback connection.
 400          */
 401         port_id_t port;
 402         rc = async_create_callback_port(exch, INTERFACE_VFS_DRIVER_CB, 0, 0,
 403             vfs_connection, NULL, &port);
 404
 405         /*
 406          * Request sharing the Path Lookup Buffer with VFS.
 407          */
 408         rc = async_share_in_start_0_0(exch, PLB_SIZE, (void *) &reg.plb_ro);
 409         if (reg.plb_ro == AS_MAP_FAILED) {
 410                 async_exchange_end(exch);
 411                 async_forget(req);
 412                 return ENOMEM;
 413         }
 414
 415         async_exchange_end(exch);
 416
 417         if (rc) {
 418                 async_forget(req);
 419                 return rc;
 420         }
 421
 422         /*
 423          * Pick up the answer for the request to the VFS_IN_REQUEST call.
 424          */
 425         async_wait_for(req, NULL);
 426         reg.fs_handle = (int) ipc_get_arg1(&answer);
 427
 428         return ipc_get_retval(&answer);
 429 }
 430
 431 void fs_node_initialize(fs_node_t *fn)
 432 {
 433         memset(fn, 0, sizeof(fs_node_t));
 434 }
 435
 436 static char plb_get_char(unsigned pos)
 437 {
 438         return reg.plb_ro[pos % PLB_SIZE];
 439 }
 440
 441 static errno_t plb_get_component(char *dest, unsigned *sz, unsigned *ppos,
 442     unsigned last)
 443 {
 444         unsigned pos = *ppos;
 445         unsigned size = 0;
 446
 447         if (pos == last) {
 448                 *sz = 0;
 449                 return ERANGE;
 450         }
 451
 452         char c = plb_get_char(pos);
 453         if (c == '/')
 454                 pos++;
 455
 456         for (int i = 0; i <= NAME_MAX; i++) {
 457                 c = plb_get_char(pos);
 458                 if (pos == last || c == '/') {
 459                         dest[i] = 0;
 460                         *ppos = pos;
 461                         *sz = size;
 462                         return EOK;
 463                 }
 464                 dest[i] = c;
 465                 pos++;
 466                 size++;
 467         }
 468         return ENAMETOOLONG;
 469 }
 470
 471 static errno_t receive_fname(char *buffer)
 472 {
 473         ipc_call_t call;
 474         size_t size;
 475
 476         if (!async_data_write_receive(&call, &size))
 477                 return ENOENT;
 478
 479         if (size > NAME_MAX + 1) {
 480                 async_answer_0(&call, ERANGE);
 481                 return ERANGE;
 482         }
 483
 484         return async_data_write_finalize(&call, buffer, size);
 485 }
 486
 487 /** Link a file at a path.
 488  *
 489  */
 490 void libfs_link(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_call_t *req)
 491 {
 492         service_id_t parent_sid = ipc_get_arg1(req);
 493         fs_index_t parent_index = ipc_get_arg2(req);
 494         fs_index_t child_index = ipc_get_arg3(req);
 495
 496         char component[NAME_MAX + 1];
 497         errno_t rc = receive_fname(component);
 498         if (rc != EOK) {
 499                 async_answer_0(req, rc);
 500                 return;
 501         }
 502
 503         fs_node_t *parent = NULL;
 504         rc = ops->node_get(&parent, parent_sid, parent_index);
 505         if (parent == NULL) {
 506                 async_answer_0(req, rc == EOK ? EBADF : rc);
 507                 return;
 508         }
 509
 510         fs_node_t *child = NULL;
 511         rc = ops->node_get(&child, parent_sid, child_index);
 512         if (child == NULL) {
 513                 async_answer_0(req, rc == EOK ? EBADF : rc);
 514                 ops->node_put(parent);
 515                 return;
 516         }
 517
 518         rc = ops->link(parent, child, component);
 519         ops->node_put(parent);
 520         ops->node_put(child);
 521         async_answer_0(req, rc);
 522 }
 523
 524 /** Lookup VFS triplet by name in the file system name space.
 525  *
 526  * The path passed in the PLB must be in the canonical file system path format
 527  * as returned by the canonify() function.
 528  *
 529  * @param ops       libfs operations structure with function pointers to
 530  *                  file system implementation
 531  * @param fs_handle File system handle of the file system where to perform
 532  *                  the lookup.
 533  * @param req       VFS_OUT_LOOKUP request data itself.
 534  *
 535  */
 536 void libfs_lookup(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_call_t *req)
 537 {
 538         unsigned first = ipc_get_arg1(req);
 539         unsigned len = ipc_get_arg2(req);
 540         service_id_t service_id = ipc_get_arg3(req);
 541         fs_index_t index = ipc_get_arg4(req);
 542         int lflag = ipc_get_arg5(req);
 543
 544         // TODO: Validate flags.
 545
 546         unsigned next = first;
 547         unsigned last = first + len;
 548
 549         char component[NAME_MAX + 1];
 550         errno_t rc;
 551
 552         fs_node_t *par = NULL;
 553         fs_node_t *cur = NULL;
 554         fs_node_t *tmp = NULL;
 555         unsigned clen = 0;
 556
 557         rc = ops->node_get(&cur, service_id, index);
 558         if (rc != EOK) {
 559                 async_answer_0(req, rc);
 560                 goto out;
 561         }
 562
 563         assert(cur != NULL);
 564
 565         /* Find the file and its parent. */
 566
 567         unsigned last_next = 0;
 568
 569         while (next != last) {
 570                 if (cur == NULL) {
 571                         assert(par != NULL);
 572                         goto out1;
 573                 }
 574
 575                 if (!ops->is_directory(cur)) {
 576                         async_answer_0(req, ENOTDIR);
 577                         goto out;
 578                 }
 579
 580                 last_next = next;
 581                 /* Collect the component */
 582                 rc = plb_get_component(component, &clen, &next, last);
 583                 assert(rc != ERANGE);
 584                 if (rc != EOK) {
 585                         async_answer_0(req, rc);
 586                         goto out;
 587                 }
 588
 589                 if (clen == 0) {
 590                         /* The path is just "/". */
 591                         break;
 592                 }
 593
 594                 assert(component[clen] == 0);
 595
 596                 /* Match the component */
 597                 rc = ops->match(&tmp, cur, component);
 598                 if (rc != EOK) {
 599                         async_answer_0(req, rc);
 600                         goto out;
 601                 }
 602
 603                 /* Descend one level */
 604                 if (par) {
 605                         rc = ops->node_put(par);
 606                         if (rc != EOK) {
 607                                 async_answer_0(req, rc);
 608                                 goto out;
 609                         }
 610                 }
 611
 612                 par = cur;
 613                 cur = tmp;
 614                 tmp = NULL;
 615         }
 616
 617         /*
 618          * At this point, par is either NULL or a directory.
 619          * If cur is NULL, the looked up file does not exist yet.
 620          */
 621
 622         assert(par == NULL || ops->is_directory(par));
 623         assert(par != NULL || cur != NULL);
 624
 625         /* Check for some error conditions. */
 626
 627         if (cur && (lflag & L_FILE) && (ops->is_directory(cur))) {
 628                 async_answer_0(req, EISDIR);
 629                 goto out;
 630         }
 631
 632         if (cur && (lflag & L_DIRECTORY) && (ops->is_file(cur))) {
 633                 async_answer_0(req, ENOTDIR);
 634                 goto out;
 635         }
 636
 637         /* Unlink. */
 638
 639         if (lflag & L_UNLINK) {
 640                 if (!cur) {
 641                         async_answer_0(req, ENOENT);
 642                         goto out;
 643                 }
 644                 if (!par) {
 645                         async_answer_0(req, EINVAL);
 646                         goto out;
 647                 }
 648
 649                 rc = ops->unlink(par, cur, component);
 650                 if (rc == EOK) {
 651                         aoff64_t size = ops->size_get(cur);
 652                         async_answer_5(req, EOK, fs_handle,
 653                             ops->index_get(cur),
 654                             (ops->is_directory(cur) << 16) | last,
 655                             LOWER32(size), UPPER32(size));
 656                 } else {
 657                         async_answer_0(req, rc);
 658                 }
 659                 goto out;
 660         }
 661
 662         /* Create. */
 663
 664         if (lflag & L_CREATE) {
 665                 if (cur && (lflag & L_EXCLUSIVE)) {
 666                         async_answer_0(req, EEXIST);
 667                         goto out;
 668                 }
 669
 670                 if (!cur) {
 671                         rc = ops->create(&cur, service_id,
 672                             lflag & (L_FILE | L_DIRECTORY));
 673                         if (rc != EOK) {
 674                                 async_answer_0(req, rc);
 675                                 goto out;
 676                         }
 677                         if (!cur) {
 678                                 async_answer_0(req, ENOSPC);
 679                                 goto out;
 680                         }
 681
 682                         rc = ops->link(par, cur, component);
 683                         if (rc != EOK) {
 684                                 (void) ops->destroy(cur);
 685                                 cur = NULL;
 686                                 async_answer_0(req, rc);
 687                                 goto out;
 688                         }
 689                 }
 690         }
 691
 692         /* Return. */
 693 out1:
 694         if (!cur) {
 695                 async_answer_5(req, EOK, fs_handle, ops->index_get(par),
 696                     (ops->is_directory(par) << 16) | last_next,
 697                     LOWER32(ops->size_get(par)), UPPER32(ops->size_get(par)));
 698                 goto out;
 699         }
 700
 701         async_answer_5(req, EOK, fs_handle, ops->index_get(cur),
 702             (ops->is_directory(cur) << 16) | last, LOWER32(ops->size_get(cur)),
 703             UPPER32(ops->size_get(cur)));
 704
 705 out:
 706         if (par)
 707                 (void) ops->node_put(par);
 708
 709         if (cur)
 710                 (void) ops->node_put(cur);
 711
 712         if (tmp)
 713                 (void) ops->node_put(tmp);
 714 }
 715
 716 void libfs_stat(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_call_t *req)
 717 {
 718         service_id_t service_id = (service_id_t) ipc_get_arg1(req);
 719         fs_index_t index = (fs_index_t) ipc_get_arg2(req);
 720
 721         fs_node_t *fn;
 722         errno_t rc = ops->node_get(&fn, service_id, index);
 723         on_error(rc, answer_and_return(req, rc));
 724
 725         ipc_call_t call;
 726         size_t size;
 727         if ((!async_data_read_receive(&call, &size)) ||
 728             (size != sizeof(vfs_stat_t))) {
 729                 ops->node_put(fn);
 730                 async_answer_0(&call, EINVAL);
 731                 async_answer_0(req, EINVAL);
 732                 return;
 733         }
 734
 735         vfs_stat_t stat;
 736         memset(&stat, 0, sizeof(vfs_stat_t));
 737
 738         stat.fs_handle = fs_handle;
 739         stat.service_id = service_id;
 740         stat.index = index;
 741         stat.lnkcnt = ops->lnkcnt_get(fn);
 742         stat.is_file = ops->is_file(fn);
 743         stat.is_directory = ops->is_directory(fn);
 744         stat.size = ops->size_get(fn);
 745         stat.service = ops->service_get(fn);
 746
 747         ops->node_put(fn);
 748
 749         async_data_read_finalize(&call, &stat, sizeof(vfs_stat_t));
 750         async_answer_0(req, EOK);
 751 }
 752
 753 void libfs_statfs(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_call_t *req)
 754 {
 755         service_id_t service_id = (service_id_t) ipc_get_arg1(req);
 756         fs_index_t index = (fs_index_t) ipc_get_arg2(req);
 757
 758         fs_node_t *fn;
 759         errno_t rc = ops->node_get(&fn, service_id, index);
 760         on_error(rc, answer_and_return(req, rc));
 761
 762         ipc_call_t call;
 763         size_t size;
 764         if ((!async_data_read_receive(&call, &size)) ||
 765             (size != sizeof(vfs_statfs_t))) {
 766                 goto error;
 767         }
 768
 769         vfs_statfs_t st;
 770         memset(&st, 0, sizeof(vfs_statfs_t));
 771
 772         str_cpy(st.fs_name, sizeof(st.fs_name), fs_name);
 773
 774         if (ops->size_block != NULL) {
 775                 rc = ops->size_block(service_id, &st.f_bsize);
 776                 if (rc != EOK)
 777                         goto error;
 778         }
 779
 780         if (ops->total_block_count != NULL) {
 781                 rc = ops->total_block_count(service_id, &st.f_blocks);
 782                 if (rc != EOK)
 783                         goto error;
 784         }
 785
 786         if (ops->free_block_count != NULL) {
 787                 rc = ops->free_block_count(service_id, &st.f_bfree);
 788                 if (rc != EOK)
 789                         goto error;
 790         }
 791
 792         ops->node_put(fn);
 793         async_data_read_finalize(&call, &st, sizeof(vfs_statfs_t));
 794         async_answer_0(req, EOK);
 795         return;
 796
 797 error:
 798         ops->node_put(fn);
 799         async_answer_0(&call, EINVAL);
 800         async_answer_0(req, EINVAL);
 801 }
 802
 803 /** Open VFS triplet.
 804  *
 805  * @param ops libfs operations structure with function pointers to
 806  *            file system implementation
 807  * @param req VFS_OUT_OPEN_NODE request data itself.
 808  *
 809  */
 810 void libfs_open_node(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_call_t *req)
 811 {
 812         service_id_t service_id = ipc_get_arg1(req);
 813         fs_index_t index = ipc_get_arg2(req);
 814
 815         fs_node_t *fn;
 816         errno_t rc = ops->node_get(&fn, service_id, index);
 817         on_error(rc, answer_and_return(req, rc));
 818
 819         if (fn == NULL) {
 820                 async_answer_0(req, ENOENT);
 821                 return;
 822         }
 823
 824         rc = ops->node_open(fn);
 825         aoff64_t size = ops->size_get(fn);
 826         async_answer_4(req, rc, LOWER32(size), UPPER32(size),
 827             ops->lnkcnt_get(fn),
 828             (ops->is_file(fn) ? L_FILE : 0) |
 829             (ops->is_directory(fn) ? L_DIRECTORY : 0));
 830
 831         (void) ops->node_put(fn);
 832 }
 833
 834 static FIBRIL_MUTEX_INITIALIZE(instances_mutex);
 835 static LIST_INITIALIZE(instances_list);
 836
 837 typedef struct {
 838         service_id_t service_id;
 839         link_t link;
 840         void *data;
 841 } fs_instance_t;
 842
 843 errno_t fs_instance_create(service_id_t service_id, void *data)
 844 {
 845         fs_instance_t *inst = malloc(sizeof(fs_instance_t));
 846         if (!inst)
 847                 return ENOMEM;
 848
 849         link_initialize(&inst->link);
 850         inst->service_id = service_id;
 851         inst->data = data;
 852
 853         fibril_mutex_lock(&instances_mutex);
 854         list_foreach(instances_list, link, fs_instance_t, cur) {
 855                 if (cur->service_id == service_id) {
 856                         fibril_mutex_unlock(&instances_mutex);
 857                         free(inst);
 858                         return EEXIST;
 859                 }
 860
 861                 /* keep the list sorted */
 862                 if (cur->service_id < service_id) {
 863                         list_insert_before(&inst->link, &cur->link);
 864                         fibril_mutex_unlock(&instances_mutex);
 865                         return EOK;
 866                 }
 867         }
 868         list_append(&inst->link, &instances_list);
 869         fibril_mutex_unlock(&instances_mutex);
 870
 871         return EOK;
 872 }
 873
 874 errno_t fs_instance_get(service_id_t service_id, void **idp)
 875 {
 876         fibril_mutex_lock(&instances_mutex);
 877
 878         list_foreach(instances_list, link, fs_instance_t, inst) {
 879                 if (inst->service_id == service_id) {
 880                         *idp = inst->data;
 881                         fibril_mutex_unlock(&instances_mutex);
 882                         return EOK;
 883                 }
 884         }
 885
 886         fibril_mutex_unlock(&instances_mutex);
 887         return ENOENT;
 888 }
 889
 890 errno_t fs_instance_destroy(service_id_t service_id)
 891 {
 892         fibril_mutex_lock(&instances_mutex);
 893
 894         list_foreach(instances_list, link, fs_instance_t, inst) {
 895                 if (inst->service_id == service_id) {
 896                         list_remove(&inst->link);
 897                         fibril_mutex_unlock(&instances_mutex);
 898                         free(inst);
 899                         return EOK;
 900                 }
 901         }
 902
 903         fibril_mutex_unlock(&instances_mutex);
 904         return ENOENT;
 905 }
 906
 907 /** @}
 908  */