servers/mfs/pipe.c

   1
   2 #include "fs.h"
   3 #include <fcntl.h>
   4 #include <signal.h>
   5 #include <minix/callnr.h>
   6 #include <minix/endpoint.h>
   7 #include <minix/com.h>
   8 #include <sys/select.h>
   9 #include <sys/time.h>
  10 #include "inode.h"
  11 #include "super.h"
  12
  13 #include <minix/vfsif.h>
  14
  15
  16
  17 /*===========================================================================*
  18  *                              fs_pipe                                      *
  19  *===========================================================================*/
  20 PUBLIC int fs_pipe(void)
  21 {
  22   struct inode *rip;
  23
  24   /* Get caller's user and group id from the request */
  25   caller_uid = fs_m_in.REQ_UID;
  26   caller_gid = fs_m_in.REQ_GID;
  27
  28   /* Try to allocate the inode */
  29   if ( (rip = alloc_inode(fs_dev, I_REGULAR) ) == NIL_INODE) {
  30         return err_code;
  31   }
  32
  33   /* !!! already checked in alloc_inode
  34   if (read_only(rip) != OK)
  35         panic(__FILE__,"pipe device is read only", NO_NUM);
  36   */
  37
  38   /* Fill in the fields of the inode */
  39   rip->i_pipe = I_PIPE;
  40   rip->i_mode &= ~I_REGULAR;
  41   rip->i_mode |= I_NAMED_PIPE;  /* pipes and FIFOs have this bit set */
  42
  43   /* We'll need it twice, nothing can go wrong here */
  44   dup_inode(rip);
  45   rw_inode(rip, WRITING);       /* mark inode as allocated */
  46   rip->i_update = ATIME | CTIME | MTIME;
  47
  48   /* Fill in the fields of the response message */
  49   fs_m_out.m_source = fs_dev;  /* filled with FS endpoint by the system */
  50   fs_m_out.RES_INODE_NR = rip->i_num;
  51   fs_m_out.RES_MODE = rip->i_mode;
  52   fs_m_out.RES_INODE_INDEX = (rip - &inode[0]) / sizeof(struct inode);
  53
  54   return OK;
  55 }
  56
  57