system/include/fs/request.h

   1 /*
   2 Copyright (C) 2008  Mathias Gottschlag
   3
   4 Permission is hereby granted, free of charge, to any person obtaining a copy of
   5 this software and associated documentation files (the "Software"), to deal in the
   6 Software without restriction, including without limitation the rights to use,
   7 copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
   8 Software, and to permit persons to whom the Software is furnished to do so,
   9 subject to the following conditions:
  10
  11 The above copyright notice and this permission notice shall be included in all
  12 copies or substantial portions of the Software.
  13
  14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
  15 INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
  16 PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  17 HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  18 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  19 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  20 */
  21 /**
  22  * \file request.h
  23  * Raw file system request functions.
  24  */
  25
  26 #ifndef FS_REQUEST_H_INCLUDED
  27 #define FS_REQUEST_H_INCLUDED
  28
  29 #include "fs/fs.h"
  30 #include "ke/spinlock.h"
  31 #include "ke/thread.h"
  32
  33 /**
  34  * File system request type
  35  */
  36 typedef enum
  37 {
  38         FS_REQUEST_READ,
  39         FS_REQUEST_WRITE,
  40         FS_REQUEST_SEEK,
  41         FS_REQUEST_IOCTL,
  42         FS_REQUEST_OPEN,
  43         FS_REQUEST_CLOSE,
  44         FS_REQUEST_MKNOD,
  45         FS_REQUEST_IOCTLSIZE
  46 } FsRequestType;
  47
  48 /**
  49  * File system request
  50  */
  51 typedef struct FsRequest
  52 {
  53         /**
  54          * Request type.
  55          */
  56         FsRequestType type;
  57         /**
  58          * Target file system.
  59          */
  60         FsFileSystem *fs;
  61         /**
  62          * Target file. Can only be 0 for FS_REQUEST_OPEN and FS_REQUEST_MKNOD.
  63          */
  64         FsFile *file;
  65         /**
  66          * Generic flags for the file system request.
  67          */
  68         uint32_t flags;
  69
  70         /**
  71          * Size of the request buffer.
  72          */
  73         uint32_t bufferlength;
  74         /**
  75          * Request buffer for data transmission.
  76          */
  77         void *buffer;
  78
  79         /**
  80          * Offset for read/write and seek operations.
  81          */
  82         int64_t offset;
  83         /**
  84          * Origin for seek operations. 0 means start of the file, 2 means end
  85          */
  86         int whence;
  87
  88         /**
  89          * If set to 0, don't perform any operations which would block the calling
  90          * thread.
  91          */
  92         int block;
  93
  94         /**
  95          * Status of the request.
  96          */
  97         int status;
  98         /**
  99          * Return value for the request type. Holds for example the number of bytes
 100          * read/written, or -1 in case of an error.
 101          */
 102         int return_value;
 103         /**
 104          * If set to 1, the request has been finished.
 105          */
 106         int finished;
 107
 108         /**
 109          * Calling process.
 110          */
 111         KeProcess *process;
 112
 113         /**
 114          * Thread waiting for the request to be completed. This will in many cases
 115          * be 0, so don't rely on this being the thread which issued the request.
 116          */
 117         KeThread *caller;
 118
 119         /**
 120          * Request lock. Can be used by file systems.
 121          */
 122         KeSpinlock lock;
 123 } FsRequest;
 124
 125 /**
 126  * Creates a file system request.
 127  * \param request Request to be issued.
 128  * \param wait If set to 1, blocks until the request has been completed.
 129  * \param process Used to override the process member of the request. If it is
 130  * 0, the process is retrieved automatically.
 131  */
 132 int fsCreateRequest(FsRequest *request, int wait, KeProcess *process);
 133 /**
 134  * Waits for a request to be completed.
 135  */
 136 int fsWaitRequest(FsRequest *request);
 137
 138 /**
 139  * Finishes a request and wakes up any thread waiting for it.
 140  */
 141 int fsFinishRequest(FsRequest *request);
 142
 143 #endif
 144