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(), (int)sys_getpid());
  42
  43         if(pipe(pfd) != 0) {
  44                 DEBUG(0,("check_kernel_oplocks: Unable to create pipe. Error was %s\n",
  45                          strerror(errno) ));
  46                 return False;
  47         }
  48
  49         if((fd = sys_open(tmpname, O_RDWR|O_CREAT|O_EXCL|O_TRUNC, 0600)) < 0) {
  50                 DEBUG(0,("check_kernel_oplocks: Unable to open temp test file %s. Error was %s\n",
  51                          tmpname, strerror(errno) ));
  52                 unlink( tmpname );
  53                 close(pfd[0]);
  54                 close(pfd[1]);
  55                 return False;
  56         }
  57
  58         unlink(tmpname);
  59
  60         if(sys_fcntl_long(fd, F_OPLKREG, pfd[1]) == -1) {
  61                 DEBUG(0,("check_kernel_oplocks: Kernel oplocks are not available on this machine. \
  62 Disabling kernel oplock support.\n" ));
  63                 close(pfd[0]);
  64                 close(pfd[1]);
  65                 close(fd);
  66                 return False;
  67         }
  68
  69         if(sys_fcntl_long(fd, F_OPLKACK, OP_REVOKE) < 0 ) {
  70                 DEBUG(0,("check_kernel_oplocks: Error when removing kernel oplock. Error was %s. \
  71 Disabling kernel oplock support.\n", strerror(errno) ));
  72                 close(pfd[0]);
  73                 close(pfd[1]);
  74                 close(fd);
  75                 return False;
  76         }
  77
  78         close(pfd[0]);
  79         close(pfd[1]);
  80         close(fd);
  81
  82         return True;
  83 }
  84
  85 /****************************************************************************
  86  * Deal with the IRIX kernel <--> smbd
  87  * oplock break protocol.
  88 ****************************************************************************/
  89
  90 static files_struct *irix_oplock_receive_message(fd_set *fds)
  91 {
  92         extern int smb_read_error;
  93         oplock_stat_t os;
  94         char dummy;
  95         files_struct *fsp;
  96
  97         /* Ensure we only get one call per select fd set. */
  98         FD_CLR(oplock_pipe_read, fds);
  99
 100         /*
 101          * Read one byte of zero to clear the
 102          * kernel break notify message.
 103          */
 104
 105         if(read(oplock_pipe_read, &dummy, 1) != 1) {
 106                 DEBUG(0,("irix_oplock_receive_message: read of kernel "
 107                          "notification failed. Error was %s.\n",
 108                          strerror(errno) ));
 109                 smb_read_error = READ_ERROR;
 110                 return NULL;
 111         }
 112
 113         /*
 114          * Do a query to get the
 115          * device and inode of the file that has the break
 116          * request outstanding.
 117          */
 118
 119         if(sys_fcntl_ptr(oplock_pipe_read, F_OPLKSTAT, &os) < 0) {
 120                 DEBUG(0,("irix_oplock_receive_message: fcntl of kernel "
 121                          "notification failed. Error was %s.\n",
 122                          strerror(errno) ));
 123                 if(errno == EAGAIN) {
 124                         /*
 125                          * Duplicate kernel break message - ignore.
 126                          */
 127                         return NULL;
 128                 }
 129                 smb_read_error = READ_ERROR;
 130                 return NULL;
 131         }
 132
 133         /*
 134          * We only have device and inode info here - we have to guess that this
 135          * is the first fsp open with this dev,ino pair.
 136          */
 137
 138         if ((fsp = file_find_di_first((SMB_DEV_T)os.os_dev,
 139                                       (SMB_INO_T)os.os_ino)) == NULL) {
 140                 DEBUG(0,("irix_oplock_receive_message: unable to find open "
 141                          "file with dev = %x, inode = %.0f\n",
 142                          (unsigned int)os.os_dev, (double)os.os_ino ));
 143                 return NULL;
 144         }
 145
 146         DEBUG(5,("irix_oplock_receive_message: kernel oplock break request "
 147                  "received for dev = %x, inode = %.0f\n, file_id = %ul",
 148                  (unsigned int)fsp->dev, (double)fsp->inode, fsp->fh->file_id ));
 149
 150         return fsp;
 151 }
 152
 153 /****************************************************************************
 154  Attempt to set an kernel oplock on a file.
 155 ****************************************************************************/
 156
 157 static BOOL irix_set_kernel_oplock(files_struct *fsp, int oplock_type)
 158 {
 159         if (sys_fcntl_long(fsp->fh->fd, F_OPLKREG, oplock_pipe_write) == -1) {
 160                 if(errno != EAGAIN) {
 161                         DEBUG(0,("irix_set_kernel_oplock: Unable to get kernel oplock on file %s, dev = %x, \
 162 inode = %.0f, file_id = %ul. Error was %s\n",
 163                                  fsp->fsp_name, (unsigned int)fsp->dev, (double)fsp->inode, fsp->fh->file_id,
 164                                  strerror(errno) ));
 165                 } else {
 166                         DEBUG(5,("irix_set_kernel_oplock: Refused oplock on file %s, fd = %d, dev = %x, \
 167 inode = %.0f, file_id = %ul. Another process had the file open.\n",
 168                                  fsp->fsp_name, fsp->fh->fd, (unsigned int)fsp->dev, (double)fsp->inode, fsp->fh->file_id ));
 169                 }
 170                 return False;
 171         }
 172
 173         DEBUG(10,("irix_set_kernel_oplock: got kernel oplock on file %s, dev = %x, inode = %.0f, file_id = %ul\n",
 174                   fsp->fsp_name, (unsigned int)fsp->dev, (double)fsp->inode, fsp->fh->file_id));
 175
 176         return True;
 177 }
 178
 179 /****************************************************************************
 180  Release a kernel oplock on a file.
 181 ****************************************************************************/
 182
 183 static void irix_release_kernel_oplock(files_struct *fsp)
 184 {
 185         if (DEBUGLVL(10)) {
 186                 /*
 187                  * Check and print out the current kernel
 188                  * oplock state of this file.
 189                  */
 190                 int state = sys_fcntl_long(fsp->fh->fd, F_OPLKACK, -1);
 191                 dbgtext("irix_release_kernel_oplock: file %s, dev = %x, inode = %.0f file_id = %ul, has kernel \
 192 oplock state of %x.\n", fsp->fsp_name, (unsigned int)fsp->dev,
 193                         (double)fsp->inode, fsp->fh->file_id, state );
 194         }
 195
 196         /*
 197          * Remove the kernel oplock on this file.
 198          */
 199         if(sys_fcntl_long(fsp->fh->fd, F_OPLKACK, OP_REVOKE) < 0) {
 200                 if( DEBUGLVL( 0 )) {
 201                         dbgtext("irix_release_kernel_oplock: Error when removing kernel oplock on file " );
 202                         dbgtext("%s, dev = %x, inode = %.0f, file_id = %ul. Error was %s\n",
 203                                 fsp->fsp_name, (unsigned int)fsp->dev,
 204                                 (double)fsp->inode, fsp->fh->file_id, strerror(errno) );
 205                 }
 206         }
 207 }
 208
 209 /****************************************************************************
 210  See if there is a message waiting in this fd set.
 211  Note that fds MAY BE NULL ! If so we must do our own select.
 212 ****************************************************************************/
 213
 214 static BOOL irix_oplock_msg_waiting(fd_set *fds)
 215 {
 216         int selrtn;
 217         fd_set myfds;
 218         struct timeval to;
 219
 220         if (oplock_pipe_read == -1)
 221                 return False;
 222
 223         if (fds) {
 224                 return FD_ISSET(oplock_pipe_read, fds);
 225         }
 226
 227         /* Do a zero-time select. We just need to find out if there
 228          * are any outstanding messages. We use sys_select_intr as
 229          * we need to ignore any signals. */
 230
 231         FD_ZERO(&myfds);
 232         FD_SET(oplock_pipe_read, &myfds);
 233
 234         to = timeval_set(0, 0);
 235         selrtn = sys_select_intr(oplock_pipe_read+1,&myfds,NULL,NULL,&to);
 236         return (selrtn == 1) ? True : False;
 237 }
 238
 239 /****************************************************************************
 240  Setup kernel oplocks.
 241 ****************************************************************************/
 242
 243 struct kernel_oplocks *irix_init_kernel_oplocks(void)
 244 {
 245         int pfd[2];
 246         static struct kernel_oplocks koplocks;
 247
 248         if (!irix_oplocks_available())
 249                 return NULL;
 250
 251         if(pipe(pfd) != 0) {
 252                 DEBUG(0,("setup_kernel_oplock_pipe: Unable to create pipe. Error was %s\n",
 253                          strerror(errno) ));
 254                 return False;
 255         }
 256
 257         oplock_pipe_read = pfd[0];
 258         oplock_pipe_write = pfd[1];
 259
 260         koplocks.receive_message = irix_oplock_receive_message;
 261         koplocks.set_oplock = irix_set_kernel_oplock;
 262         koplocks.release_oplock = irix_release_kernel_oplock;
 263         koplocks.msg_waiting = irix_oplock_msg_waiting;
 264         koplocks.notification_fd = oplock_pipe_read;
 265
 266         return &koplocks;
 267 }
 268 #else
 269  void oplock_irix_dummy(void) {}
 270 #endif /* HAVE_KERNEL_OPLOCKS_IRIX */