Logo Search packages:      
Sourcecode: samba-doc-ja version File versions

oplock_irix.c

/*
   Unix SMB/Netbios implementation.
   Version 2.x
   IRIX kernel oplock processing
   Copyright (C) Andrew Tridgell 1992-1998
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

#if HAVE_KERNEL_OPLOCKS_IRIX

static int oplock_pipe_write = -1;
static int oplock_pipe_read = -1;

/****************************************************************************
 Test to see if IRIX kernel oplocks work.
****************************************************************************/

static BOOL irix_oplocks_available(void)
{
      int fd;
      int pfd[2];
      pstring tmpname;

      oplock_set_capability(True, False);

      slprintf(tmpname,sizeof(tmpname)-1, "%s/koplock.%d", lp_lockdir(), (int)sys_getpid());

      if(pipe(pfd) != 0) {
            DEBUG(0,("check_kernel_oplocks: Unable to create pipe. Error was %s\n",
                   strerror(errno) ));
            return False;
      }

      if((fd = sys_open(tmpname, O_RDWR|O_CREAT|O_EXCL|O_TRUNC, 0600)) < 0) {
            DEBUG(0,("check_kernel_oplocks: Unable to open temp test file %s. Error was %s\n",
                   tmpname, strerror(errno) ));
            unlink( tmpname );
            close(pfd[0]);
            close(pfd[1]);
            return False;
      }

      unlink(tmpname);

      if(sys_fcntl_long(fd, F_OPLKREG, pfd[1]) == -1) {
            DEBUG(0,("check_kernel_oplocks: Kernel oplocks are not available on this machine. \
Disabling kernel oplock support.\n" ));
            close(pfd[0]);
            close(pfd[1]);
            close(fd);
            return False;
      }

      if(sys_fcntl_long(fd, F_OPLKACK, OP_REVOKE) < 0 ) {
            DEBUG(0,("check_kernel_oplocks: Error when removing kernel oplock. Error was %s. \
Disabling kernel oplock support.\n", strerror(errno) ));
            close(pfd[0]);
            close(pfd[1]);
            close(fd);
            return False;
      }

      close(pfd[0]);
      close(pfd[1]);
      close(fd);

      return True;
}

/****************************************************************************
 * Deal with the IRIX kernel <--> smbd
 * oplock break protocol.
****************************************************************************/

static BOOL irix_oplock_receive_message(fd_set *fds, char *buffer, int buffer_len)
{
      extern int smb_read_error;
      oplock_stat_t os;
      char dummy;
      files_struct *fsp;

      /*
       * Read one byte of zero to clear the
       * kernel break notify message.
       */

      if(read(oplock_pipe_read, &dummy, 1) != 1) {
            DEBUG(0,("irix_oplock_receive_message: read of kernel notification failed. \
Error was %s.\n", strerror(errno) ));
            smb_read_error = READ_ERROR;
            return False;
      }

      /*
       * Do a query to get the
       * device and inode of the file that has the break
       * request outstanding.
       */

      if(sys_fcntl_ptr(oplock_pipe_read, F_OPLKSTAT, &os) < 0) {
            DEBUG(0,("irix_oplock_receive_message: fcntl of kernel notification failed. \
Error was %s.\n", strerror(errno) ));
            if(errno == EAGAIN) {
                  /*
                   * Duplicate kernel break message - ignore.
                   */
                  memset(buffer, '\0', KERNEL_OPLOCK_BREAK_MSG_LEN);
                  return True;
            }
            smb_read_error = READ_ERROR;
            return False;
      }

      /*
       * We only have device and inode info here - we have to guess that this
       * is the first fsp open with this dev,ino pair.
       */

      if ((fsp = file_find_di_first((SMB_DEV_T)os.os_dev, (SMB_INO_T)os.os_ino)) == NULL) {
            DEBUG(0,("irix_oplock_receive_message: unable to find open file with dev = %x, inode = %.0f\n",
                  (unsigned int)os.os_dev, (double)os.os_ino ));
            return False;
      }
     
      DEBUG(5,("irix_oplock_receive_message: kernel oplock break request received for \
dev = %x, inode = %.0f\n, file_id = %ul", (unsigned int)fsp->dev, (double)fsp->inode, fsp->file_id ));
     
      /*
       * Create a kernel oplock break message.
       */
    
      /* Setup the message header */
      SIVAL(buffer,OPBRK_CMD_LEN_OFFSET,KERNEL_OPLOCK_BREAK_MSG_LEN);
      SSVAL(buffer,OPBRK_CMD_PORT_OFFSET,0);
   
      buffer += OPBRK_CMD_HEADER_LEN;
     
      SSVAL(buffer,OPBRK_MESSAGE_CMD_OFFSET,KERNEL_OPLOCK_BREAK_CMD);
   
      memcpy(buffer + KERNEL_OPLOCK_BREAK_DEV_OFFSET, (char *)&fsp->dev, sizeof(fsp->dev));
      memcpy(buffer + KERNEL_OPLOCK_BREAK_INODE_OFFSET, (char *)&fsp->inode, sizeof(fsp->inode));     
      memcpy(buffer + KERNEL_OPLOCK_BREAK_FILEID_OFFSET, (char *)&fsp->file_id, sizeof(fsp->file_id));      
   
      return True;
}

/****************************************************************************
 Attempt to set an kernel oplock on a file.
****************************************************************************/

static BOOL irix_set_kernel_oplock(files_struct *fsp, int oplock_type)
{
      if (sys_fcntl_long(fsp->fd, F_OPLKREG, oplock_pipe_write) == -1) {
            if(errno != EAGAIN) {
                  DEBUG(0,("irix_set_kernel_oplock: Unable to get kernel oplock on file %s, dev = %x, \
inode = %.0f, file_id = %ul. Error was %s\n", 
                         fsp->fsp_name, (unsigned int)fsp->dev, (double)fsp->inode, fsp->file_id,
                         strerror(errno) ));
            } else {
                  DEBUG(5,("irix_set_kernel_oplock: Refused oplock on file %s, fd = %d, dev = %x, \
inode = %.0f, file_id = %ul. Another process had the file open.\n",
                         fsp->fsp_name, fsp->fd, (unsigned int)fsp->dev, (double)fsp->inode, fsp->file_id ));
            }
            return False;
      }
      
      DEBUG(10,("irix_set_kernel_oplock: got kernel oplock on file %s, dev = %x, inode = %.0f, file_id = %ul\n",
              fsp->fsp_name, (unsigned int)fsp->dev, (double)fsp->inode, fsp->file_id));

      return True;
}

/****************************************************************************
 Release a kernel oplock on a file.
****************************************************************************/

static void irix_release_kernel_oplock(files_struct *fsp)
{
      if (DEBUGLVL(10)) {
            /*
             * Check and print out the current kernel
             * oplock state of this file.
             */
            int state = sys_fcntl_long(fsp->fd, F_OPLKACK, -1);
            dbgtext("irix_release_kernel_oplock: file %s, dev = %x, inode = %.0f file_id = %ul, has kernel \
oplock state of %x.\n", fsp->fsp_name, (unsigned int)fsp->dev,
                        (double)fsp->inode, fsp->file_id, state );
      }

      /*
       * Remove the kernel oplock on this file.
       */
      if(sys_fcntl_long(fsp->fd, F_OPLKACK, OP_REVOKE) < 0) {
            if( DEBUGLVL( 0 )) {
                  dbgtext("irix_release_kernel_oplock: Error when removing kernel oplock on file " );
                  dbgtext("%s, dev = %x, inode = %.0f, file_id = %ul. Error was %s\n",
                        fsp->fsp_name, (unsigned int)fsp->dev, 
                        (double)fsp->inode, fsp->file_id, strerror(errno) );
            }
      }
}

/****************************************************************************
 Parse a kernel oplock message.
****************************************************************************/

static BOOL irix_kernel_oplock_parse(char *msg_start, int msg_len,
            SMB_INO_T *inode, SMB_DEV_T *dev, unsigned long *file_id)
{
      /* Ensure that the msg length is correct. */
      if(msg_len != KERNEL_OPLOCK_BREAK_MSG_LEN) {
            DEBUG(0,("incorrect length for KERNEL_OPLOCK_BREAK_CMD (was %d, should be %d).\n", 
                   msg_len, KERNEL_OPLOCK_BREAK_MSG_LEN));
            return False;
      }

      memcpy((char *)inode, msg_start+KERNEL_OPLOCK_BREAK_INODE_OFFSET, sizeof(*inode));
      memcpy((char *)dev, msg_start+KERNEL_OPLOCK_BREAK_DEV_OFFSET, sizeof(*dev));
      memcpy((char *)file_id, msg_start+KERNEL_OPLOCK_BREAK_FILEID_OFFSET, sizeof(*file_id));

      DEBUG(5,("kernel oplock break request for file dev = %x, inode = %.0f, file_id = %ul\n", 
            (unsigned int)*dev, (double)*inode, *file_id));

      return True;
}

/****************************************************************************
 Set *maxfd to include oplock read pipe.
****************************************************************************/

static BOOL irix_oplock_msg_waiting(fd_set *fds)
{
      if (oplock_pipe_read == -1)
            return False;

      return FD_ISSET(oplock_pipe_read,fds);
}

/****************************************************************************
 Setup kernel oplocks.
****************************************************************************/

struct kernel_oplocks *irix_init_kernel_oplocks(void) 
{
      int pfd[2];
      static struct kernel_oplocks koplocks;

      if (!irix_oplocks_available())
            return NULL;

      if(pipe(pfd) != 0) {
            DEBUG(0,("setup_kernel_oplock_pipe: Unable to create pipe. Error was %s\n",
                   strerror(errno) ));
            return False;
      }

      oplock_pipe_read = pfd[0];
      oplock_pipe_write = pfd[1];

      koplocks.receive_message = irix_oplock_receive_message;
      koplocks.set_oplock = irix_set_kernel_oplock;
      koplocks.release_oplock = irix_release_kernel_oplock;
      koplocks.parse_message = irix_kernel_oplock_parse;
      koplocks.msg_waiting = irix_oplock_msg_waiting;
      koplocks.notification_fd = oplock_pipe_read;

      return &koplocks;
}
#else
 void oplock_irix_dummy(void) {}
#endif /* HAVE_KERNEL_OPLOCKS_IRIX */

Generated by  Doxygen 1.6.0   Back to index