source/smbd/oplock_irix.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    IRIX kernel oplock processing
   4    Copyright (C) Andrew Tridgell 1992-1998
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #define DBGC_CLASS DBGC_LOCKING
  22 #include "includes.h"
  23
  24 #if HAVE_KERNEL_OPLOCKS_IRIX
  25
  26 static int oplock_pipe_write = -1;
  27 static int oplock_pipe_read = -1;
  28
  29 /****************************************************************************
  30  Test to see if IRIX kernel oplocks work.
  31 ****************************************************************************/
  32
  33 static BOOL irix_oplocks_available(void)
  34 {
  35         int fd;
  36         int pfd[2];
  37         pstring tmpname;
  38
  39         set_effective_capability(KERNEL_OPLOCK_CAPABILITY);
  40
  41         slprintf(tmpname,sizeof(tmpname)-1, "%s/koplock.%d", lp_lockdir(),
  42                  (int)sys_getpid());
  43
  44         if(pipe(pfd) != 0) {
  45                 DEBUG(0,("check_kernel_oplocks: Unable to create pipe. Error "
  46                          "was %s\n",
  47                          strerror(errno) ));
  48                 return False;
  49         }
  50
  51         if((fd = sys_open(tmpname, O_RDWR|O_CREAT|O_EXCL|O_TRUNC, 0600)) < 0) {
  52                 DEBUG(0,("check_kernel_oplocks: Unable to open temp test file "
  53                          "%s. Error was %s\n",
  54                          tmpname, strerror(errno) ));
  55                 unlink( tmpname );
  56                 close(pfd[0]);
  57                 close(pfd[1]);
  58                 return False;
  59         }
  60
  61         unlink(tmpname);
  62
  63         if(sys_fcntl_long(fd, F_OPLKREG, pfd[1]) == -1) {
  64                 DEBUG(0,("check_kernel_oplocks: Kernel oplocks are not "
  65                          "available on this machine. Disabling kernel oplock "
  66                          "support.\n" ));
  67                 close(pfd[0]);
  68                 close(pfd[1]);
  69                 close(fd);
  70                 return False;
  71         }
  72
  73         if(sys_fcntl_long(fd, F_OPLKACK, OP_REVOKE) < 0 ) {
  74                 DEBUG(0,("check_kernel_oplocks: Error when removing kernel "
  75                          "oplock. Error was %s. Disabling kernel oplock "
  76                          "support.\n", strerror(errno) ));
  77                 close(pfd[0]);
  78                 close(pfd[1]);
  79                 close(fd);
  80                 return False;
  81         }
  82
  83         close(pfd[0]);
  84         close(pfd[1]);
  85         close(fd);
  86
  87         return True;
  88 }
  89
  90 /****************************************************************************
  91  * Deal with the IRIX kernel <--> smbd
  92  * oplock break protocol.
  93 ****************************************************************************/
  94
  95 static files_struct *irix_oplock_receive_message(fd_set *fds)
  96 {
  97         extern int smb_read_error;
  98         oplock_stat_t os;
  99         char dummy;
 100         files_struct *fsp;
 101
 102         /* Ensure we only get one call per select fd set. */
 103         FD_CLR(oplock_pipe_read, fds);
 104
 105         /*
 106          * Read one byte of zero to clear the
 107          * kernel break notify message.
 108          */
 109
 110         if(read(oplock_pipe_read, &dummy, 1) != 1) {
 111                 DEBUG(0,("irix_oplock_receive_message: read of kernel "
 112                          "notification failed. Error was %s.\n",
 113                          strerror(errno) ));
 114                 smb_read_error = READ_ERROR;
 115                 return NULL;
 116         }
 117
 118         /*
 119          * Do a query to get the
 120          * device and inode of the file that has the break
 121          * request outstanding.
 122          */
 123
 124         if(sys_fcntl_ptr(oplock_pipe_read, F_OPLKSTAT, &os) < 0) {
 125                 DEBUG(0,("irix_oplock_receive_message: fcntl of kernel "
 126                          "notification failed. Error was %s.\n",
 127                          strerror(errno) ));
 128                 if(errno == EAGAIN) {
 129                         /*
 130                          * Duplicate kernel break message - ignore.
 131                          */
 132                         return NULL;
 133                 }
 134                 smb_read_error = READ_ERROR;
 135                 return NULL;
 136         }
 137
 138         /*
 139          * We only have device and inode info here - we have to guess that this
 140          * is the first fsp open with this dev,ino pair.
 141          */
 142
 143         if ((fsp = file_find_di_first((SMB_DEV_T)os.os_dev,
 144                                       (SMB_INO_T)os.os_ino)) == NULL) {
 145                 DEBUG(0,("irix_oplock_receive_message: unable to find open "
 146                          "file with dev = %x, inode = %.0f\n",
 147                          (unsigned int)os.os_dev, (double)os.os_ino ));
 148                 return NULL;
 149         }
 150
 151         DEBUG(5,("irix_oplock_receive_message: kernel oplock break request "
 152                  "received for dev = %x, inode = %.0f\n, file_id = %ul",
 153                  (unsigned int)fsp->dev, (double)fsp->inode,
 154                  fsp->fh->file_id ));
 155
 156         return fsp;
 157 }
 158
 159 /****************************************************************************
 160  Attempt to set an kernel oplock on a file.
 161 ****************************************************************************/
 162
 163 static BOOL irix_set_kernel_oplock(files_struct *fsp, int oplock_type)
 164 {
 165         if (sys_fcntl_long(fsp->fh->fd, F_OPLKREG, oplock_pipe_write) == -1) {
 166                 if(errno != EAGAIN) {
 167                         DEBUG(0,("irix_set_kernel_oplock: Unable to get "
 168                                  "kernel oplock on file %s, dev = %x, inode "
 169                                  "= %.0f, file_id = %ul. Error was %s\n",
 170                                  fsp->fsp_name, (unsigned int)fsp->dev,
 171                                  (double)fsp->inode, fsp->fh->file_id,
 172                                  strerror(errno) ));
 173                 } else {
 174                         DEBUG(5,("irix_set_kernel_oplock: Refused oplock on "
 175                                  "file %s, fd = %d, dev = %x, inode = %.0f, "
 176                                  "file_id = %ul. Another process had the file "
 177                                  "open.\n",
 178                                  fsp->fsp_name, fsp->fh->fd,
 179                                  (unsigned int)fsp->dev, (double)fsp->inode,
 180                                  fsp->fh->file_id ));
 181                 }
 182                 return False;
 183         }
 184
 185         DEBUG(10,("irix_set_kernel_oplock: got kernel oplock on file %s, dev "
 186                   "= %x, inode = %.0f, file_id = %ul\n",
 187                   fsp->fsp_name, (unsigned int)fsp->dev, (double)fsp->inode,
 188                   fsp->fh->file_id));
 189
 190         return True;
 191 }
 192
 193 /****************************************************************************
 194  Release a kernel oplock on a file.
 195 ****************************************************************************/
 196
 197 static void irix_release_kernel_oplock(files_struct *fsp)
 198 {
 199         if (DEBUGLVL(10)) {
 200                 /*
 201                  * Check and print out the current kernel
 202                  * oplock state of this file.
 203                  */
 204                 int state = sys_fcntl_long(fsp->fh->fd, F_OPLKACK, -1);
 205                 dbgtext("irix_release_kernel_oplock: file %s, dev = %x, "
 206                         "inode = %.0f file_id = %ul, has kernel oplock state "
 207                         "of %x.\n", fsp->fsp_name, (unsigned int)fsp->dev,
 208                         (double)fsp->inode, fsp->fh->file_id, state );
 209         }
 210
 211         /*
 212          * Remove the kernel oplock on this file.
 213          */
 214         if(sys_fcntl_long(fsp->fh->fd, F_OPLKACK, OP_REVOKE) < 0) {
 215                 if( DEBUGLVL( 0 )) {
 216                         dbgtext("irix_release_kernel_oplock: Error when "
 217                                 "removing kernel oplock on file " );
 218                         dbgtext("%s, dev = %x, inode = %.0f, file_id = %ul. "
 219                                 "Error was %s\n",
 220                                 fsp->fsp_name, (unsigned int)fsp->dev,
 221                                 (double)fsp->inode, fsp->fh->file_id,
 222                                 strerror(errno) );
 223                 }
 224         }
 225 }
 226
 227 /****************************************************************************
 228  See if there is a message waiting in this fd set.
 229  Note that fds MAY BE NULL ! If so we must do our own select.
 230 ****************************************************************************/
 231
 232 static BOOL irix_oplock_msg_waiting(fd_set *fds)
 233 {
 234         int selrtn;
 235         fd_set myfds;
 236         struct timeval to;
 237
 238         if (oplock_pipe_read == -1)
 239                 return False;
 240
 241         if (fds) {
 242                 return FD_ISSET(oplock_pipe_read, fds);
 243         }
 244
 245         /* Do a zero-time select. We just need to find out if there
 246          * are any outstanding messages. We use sys_select_intr as
 247          * we need to ignore any signals. */
 248
 249         FD_ZERO(&myfds);
 250         FD_SET(oplock_pipe_read, &myfds);
 251
 252         to = timeval_set(0, 0);
 253         selrtn = sys_select_intr(oplock_pipe_read+1,&myfds,NULL,NULL,&to);
 254         return (selrtn == 1) ? True : False;
 255 }
 256
 257 /****************************************************************************
 258  Setup kernel oplocks.
 259 ****************************************************************************/
 260
 261 struct kernel_oplocks *irix_init_kernel_oplocks(void)
 262 {
 263         int pfd[2];
 264         static struct kernel_oplocks koplocks;
 265
 266         if (!irix_oplocks_available())
 267                 return NULL;
 268
 269         if(pipe(pfd) != 0) {
 270                 DEBUG(0,("setup_kernel_oplock_pipe: Unable to create pipe. "
 271                          "Error was %s\n", strerror(errno) ));
 272                 return False;
 273         }
 274
 275         oplock_pipe_read = pfd[0];
 276         oplock_pipe_write = pfd[1];
 277
 278         koplocks.receive_message = irix_oplock_receive_message;
 279         koplocks.set_oplock = irix_set_kernel_oplock;
 280         koplocks.release_oplock = irix_release_kernel_oplock;
 281         koplocks.msg_waiting = irix_oplock_msg_waiting;
 282         koplocks.notification_fd = oplock_pipe_read;
 283
 284         return &koplocks;
 285 }
 286 #else
 287  void oplock_irix_dummy(void);
 288  void oplock_irix_dummy(void) {}
 289 #endif /* HAVE_KERNEL_OPLOCKS_IRIX */