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  1. /*
  2.  * Copyright (c) 2008 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 fs
  30.  * @{
  31.  */
  32.  
  33. /**
  34.  * @file vfs.c
  35.  * @brief VFS service for HelenOS.
  36.  */
  37.  
  38. #include <ipc/ipc.h>
  39. #include <ipc/services.h>
  40. #include <async.h>
  41. #include <errno.h>
  42. #include <stdio.h>
  43. #include <bool.h>
  44. #include <string.h>
  45. #include <as.h>
  46. #include <libadt/list.h>
  47. #include <atomic.h>
  48. #include "vfs.h"
  49.  
  50. #define NAME "vfs"
  51.  
  52. static void vfs_connection(ipc_callid_t iid, ipc_call_t *icall)
  53. {
  54.     bool keep_on_going = true;
  55.    
  56.     /*
  57.      * The connection was opened via the IPC_CONNECT_ME_TO call.
  58.      * This call needs to be answered.
  59.      */
  60.     ipc_answer_0(iid, EOK);
  61.    
  62.     /*
  63.      * Here we enter the main connection fibril loop.
  64.      * The logic behind this loop and the protocol is that we'd like to keep
  65.      * each connection open until the client hangs up. When the client hangs
  66.      * up, we will free its VFS state. The act of hanging up the connection
  67.      * by the client is equivalent to client termination because we cannot
  68.      * distinguish one from the other. On the other hand, the client can
  69.      * hang up arbitrarily if it has no open files and reestablish the
  70.      * connection later.
  71.      */
  72.     while (keep_on_going) {
  73.         ipc_call_t call;
  74.         ipc_callid_t callid = async_get_call(&call);
  75.        
  76.         fs_handle_t fs_handle;
  77.         int phone;
  78.        
  79.         switch (IPC_GET_METHOD(call)) {
  80.         case IPC_M_PHONE_HUNGUP:
  81.             keep_on_going = false;
  82.             break;
  83.         case IPC_M_CONNECT_ME_TO:
  84.             /*
  85.              * Connect the client file system to another one.
  86.              */
  87.             /* FIXME:
  88.              * Prevent ordinary clients from connecting to file
  89.              * system servers directly. This should be solved by
  90.              * applying some security mechanisms.
  91.              */
  92.             fs_handle = IPC_GET_ARG1(call);
  93.             phone = vfs_grab_phone(fs_handle);
  94.             (void) ipc_forward_fast(callid, phone, 0, 0, 0,
  95.                 IPC_FF_NONE);
  96.             vfs_release_phone(phone);
  97.             break;
  98.         case VFS_REGISTER:
  99.             vfs_register(callid, &call);
  100.             /*
  101.              * Keep the connection open so that a file system can
  102.              * later ask us to connect it to another file system.
  103.              * This is necessary to support non-root mounts.
  104.              */
  105.             break;
  106.         case VFS_MOUNT:
  107.             vfs_mount(callid, &call);
  108.             break;
  109.         case VFS_OPEN:
  110.             vfs_open(callid, &call);
  111.             break;
  112.         case VFS_CLOSE:
  113.             vfs_close(callid, &call);
  114.             break;
  115.         case VFS_READ:
  116.             vfs_read(callid, &call);
  117.             break;
  118.         case VFS_WRITE:
  119.             vfs_write(callid, &call);
  120.             break;
  121.         case VFS_SEEK:
  122.             vfs_seek(callid, &call);
  123.             break;
  124.         case VFS_TRUNCATE:
  125.             vfs_truncate(callid, &call);
  126.             break;
  127.         case VFS_MKDIR:
  128.             vfs_mkdir(callid, &call);
  129.             break;
  130.         case VFS_UNLINK:
  131.             vfs_unlink(callid, &call);
  132.             break;
  133.         case VFS_RENAME:
  134.             vfs_rename(callid, &call);
  135.             break;
  136.         default:
  137.             ipc_answer_0(callid, ENOTSUP);
  138.             break;
  139.         }
  140.     }
  141.    
  142.     /* TODO: cleanup after the client */
  143. }
  144.  
  145. int main(int argc, char **argv)
  146. {
  147.     printf(NAME ": HelenOS VFS server\n");
  148.    
  149.     /*
  150.      * Initialize the list of registered file systems.
  151.      */
  152.     list_initialize(&fs_head);
  153.    
  154.     /*
  155.      * Initialize VFS node hash table.
  156.      */
  157.     if (!vfs_nodes_init()) {
  158.         printf(NAME ": Failed to initialize VFS node hash table\n");
  159.         return ENOMEM;
  160.     }
  161.    
  162.     /*
  163.      * Allocate and initialize the Path Lookup Buffer.
  164.      */
  165.     list_initialize(&plb_head);
  166.     plb = as_get_mappable_page(PLB_SIZE);
  167.     if (!plb) {
  168.         printf(NAME ": Cannot allocate a mappable piece of address space\n");
  169.         return ENOMEM;
  170.     }
  171.    
  172.     if (as_area_create(plb, PLB_SIZE, AS_AREA_READ | AS_AREA_WRITE |
  173.         AS_AREA_CACHEABLE) != plb) {
  174.         printf(NAME ": Cannot create address space area\n");
  175.         return ENOMEM;
  176.     }
  177.     memset(plb, 0, PLB_SIZE);
  178.    
  179.     /*
  180.      * Set a connectio handling function/fibril.
  181.      */
  182.     async_set_client_connection(vfs_connection);
  183.    
  184.     /*
  185.      * Register at the naming service.
  186.      */
  187.     ipcarg_t phonead;
  188.     ipc_connect_to_me(PHONE_NS, SERVICE_VFS, 0, 0, &phonead);
  189.    
  190.     /*
  191.      * Start accepting connections.
  192.      */
  193.     printf(NAME ": Accepting connections\n");
  194.     async_manager();
  195.     return 0;
  196. }
  197.  
  198. /**
  199.  * @}
  200.  */
  201.