funfs/wvfuse.cc

   1 /*
   2  * WvFUSE:  A WvStreams library for FUSE.
   3  *   Copyright (C) 2002 Net Integration Technologies, Inc.
   4  *
   5  * This program can be distributed under the terms of the GNU GPL.
   6  * See the file COPYING.
   7  *
   8  * This class implements the main FUSE functions:  creating the filesystem,
   9  *   reading commands, creating objects to process the commands, maintaining
  10  *   nodes, etc.
  11  */
  12
  13 #include "wvfuse.h"
  14 #include "wvfusecmd.h"
  15
  16 #include <errno.h>
  17 #include <unistd.h>
  18
  19
  20 WvFuse::WvFuse(WvFS *_fs, UniConf &_cfg)
  21     : WvFuseInoMgr(_cfg), fs(_fs), log("WvFuse", WvLog::Debug4), s(dup(0))
  22 {
  23     WvString realver = getenv(FUSE_KERNEL_VERSION_ENV);
  24     WvString verstr(FUSE_KERNEL_VERSION);
  25
  26     if (realver != verstr)
  27         log(WvLog::Warning, "FUSE version mismatch:  using %s, kernel is %s\n",
  28             realver, verstr);
  29
  30     fs_unmounted = false;
  31
  32     fs->set_message_callback(WvFSMessageCB(this, &WvFuse::message_handler));
  33
  34     append(&s, false);
  35 }
  36
  37
  38 WvFuse::~WvFuse()
  39 {
  40     log(WvLog::Info, "WvFuse dying.\n");
  41     zap();
  42 }
  43
  44
  45 int WvFuse::getfd() const
  46 {
  47     return s.getfd();
  48 }
  49
  50
  51 void WvFuse::send_reply_raw(char *outbuf, size_t outsize)
  52 {
  53     fuse_out_header *out = (fuse_out_header *) outbuf;
  54     log(WvLog::Debug5, "   unique: %s error: %s (%s) outsize: %s\n", out->unique,
  55         out->error, strerror(-out->error), outsize);
  56
  57     // We have to use uwrite here, because we don't want an
  58     // unsuccessful write to buffer.
  59     int res = s.uwrite(outbuf, outsize);
  60
  61     if (!res && geterr())
  62         log(WvLog::Error, "Error writing to device.\n");
  63 }
  64
  65
  66 bool WvFuse::isok() const
  67 {
  68     if (fs_unmounted)
  69         return false;
  70     return WvStreamList::isok();
  71 }
  72
  73
  74 void WvFuse::do_invalidate(fino_t ino)
  75 {
  76     size_t outsize = sizeof(fuse_out_header) + sizeof(ino);
  77     char *outbuf = new char[outsize];
  78
  79     fuse_out_header *out = (fuse_out_header *)outbuf;
  80
  81     out->unique = 0;
  82     out->error = 0;
  83
  84     memcpy(outbuf + sizeof(fuse_out_header), &ino, sizeof(ino));
  85
  86     send_reply_raw(outbuf, outsize);
  87     delete[] outbuf;
  88 }
  89
  90
  91 void WvFuse::message_handler(int type, WvStringParm path)
  92 {
  93     switch (type)
  94     {
  95         case FUSE_INVAL_FD:
  96             {
  97                 log(WvLog::Debug2, "Got invalidation message for fd %s\n",
  98                         path);
  99                 fino_t ino = get_ino_by_fd(atoi(path.cstr()));
 100                 if (!ino)
 101                     log(WvLog::Error, "Bad invalidating message! (fd = %s)\n",
 102                             path);
 103                 else
 104                     do_invalidate(ino);
 105             }
 106             break;
 107         case FUSE_INVAL_PATH:
 108             {
 109                 log(WvLog::Debug2, "Got invalidation message for path %s\n", path);
 110                 fino_t ino = get_ino_by_path(path);
 111                 if (!ino)
 112                     log(WvLog::Error, "Bad invalidating message! (path = %s)\n",
 113                             path);
 114                 else
 115                     do_invalidate(ino);
 116             }
 117             break;
 118         default:
 119             log(WvLog::Warning, "Unhandler message type [%s]\n", type);
 120             break;
 121     }
 122 }
 123
 124
 125 void WvFuse::execute()
 126 {
 127     WvStreamList::execute();
 128     if (s.select(0, true, false, false))
 129     {
 130         char *cmd = new char[FUSE_MAX_IN];
 131         int res = s.read(cmd, FUSE_MAX_IN);
 132         if (!res)
 133         {
 134             /* ENODEV means we got unmounted, so we silenty return failure */
 135             if (s.geterr() != ENODEV)
 136             {
 137                 log(WvLog::Error, "Error reading device\n");
 138                 /* BAD... This will happen again */
 139             }
 140             fs_unmounted = true;
 141             delete cmd;
 142             return;
 143         }
 144
 145         if ((size_t) res < sizeof(fuse_in_header))
 146         {
 147             log(WvLog::Error, "Short read on fuse device\n");
 148             /* Cannot happen */  /* Yeah, right! */
 149             delete cmd;
 150             return;
 151         }
 152
 153         WvFuseCmd *fusecmd = new WvFuseCmd(this, fs, cmd);
 154         append(fusecmd, true);
 155     }
 156 }