VFS - cancel_nblock()

- duplicate code in dev_io() which sends CANCEL in case of a
  non-blocking operation moved to cancel_nblock()

diff --git a/servers/vfs/device.c b/servers/vfs/device.c
index 4700701b1be7ab843230e2c7a42c2781f25a3178..adbcd9e6bf9ddffb3ee0605aa93e3792bc7fb04a 100644 (file)
--- a/servers/vfs/device.c
+++ b/servers/vfs/device.c
@@ -362,6 +362,32 @@ u32_t *pos_lo;
   return(0);
 }
 
+PRIVATE int cancel_nblock(struct dmap * dp,
+                       int minor,
+                       int call,
+                       endpoint_t ioproc,
+                       cp_grant_id_t gid)
+{
+  message dev_mess;
+
+  dev_mess.m_type = CANCEL;
+  dev_mess.USER_ENDPT = ioproc;
+  dev_mess.IO_GRANT = (char *) gid;
+
+  /* This R_BIT/W_BIT check taken from suspend()/unpause()
+   * logic. Mode is expected in the COUNT field.
+   */
+  dev_mess.COUNT = 0;
+  if (call == READ)
+         dev_mess.COUNT = R_BIT;
+  else if (call == WRITE)
+         dev_mess.COUNT = W_BIT;
+  dev_mess.DEVICE = minor;
+  (*dp->dmap_io)(dp->dmap_driver, &dev_mess);
+  
+  return dev_mess.REP_STATUS;
+}
+
 /*===========================================================================*
  *                             dev_io                                       *
  *===========================================================================*/
@@ -384,6 +410,7 @@ PUBLIC int dev_io(
   int safe, minor_dev, major_dev;
   void *buf_used;
   endpoint_t ioproc;
+  int ret;
 
   pos_lo = ex64lo(pos);
   pos_high = ex64hi(pos);
@@ -446,24 +473,16 @@ PUBLIC int dev_io(
        return(EIO);
   }
 
+  ret = dev_mess.REP_STATUS;
+
   /* Task has completed.  See if call completed. */
-  if (dev_mess.REP_STATUS == SUSPEND) {
+  if (ret == SUSPEND) {
        if ((flags & O_NONBLOCK) && !(dp->dmap_style == STYLE_DEVA ||
                                      dp->dmap_style == STYLE_CLONE_A)) {
                /* Not supposed to block. */
-               dev_mess.m_type = CANCEL;
-               dev_mess.USER_ENDPT = ioproc;
-               dev_mess.IO_GRANT = (char *) gid;
-
-               /* This R_BIT/W_BIT check taken from suspend()/unpause()
-                * logic. Mode is expected in the COUNT field.
-                */
-               dev_mess.COUNT = 0;
-               if (call_nr == READ)            dev_mess.COUNT = R_BIT;
-               else if (call_nr == WRITE)      dev_mess.COUNT = W_BIT;
-               dev_mess.DEVICE = minor_dev;
-               (*dp->dmap_io)(dp->dmap_driver, &dev_mess);
-               if (dev_mess.REP_STATUS == EINTR) dev_mess.REP_STATUS = EAGAIN;
+               ret = cancel_nblock(dp, minor_dev, call_nr, ioproc, gid);
+               if (ret == EINTR)
+                       ret = EAGAIN;
        } else {
                /* select() will do suspending itself. */
                if(op != DEV_SELECT) {
@@ -476,20 +495,11 @@ PUBLIC int dev_io(
 
                if (flags & O_NONBLOCK) {
                        /* Not supposed to block, send cancel message */
-                       dev_mess.m_type = CANCEL;
-                       dev_mess.USER_ENDPT = ioproc;
-                       dev_mess.IO_GRANT = (char *) gid;
-
-                       /* This R_BIT/W_BIT check taken from suspend()/unpause()
-                        * logic. Mode is expected in the COUNT field.
+                       cancel_nblock(dp, minor_dev, call_nr, ioproc, gid);
+                       /*
+                        * FIXME Should do something about EINTR -> EAGAIN
+                        * mapping
                         */
-                       dev_mess.COUNT = 0;
-                       if(call_nr == READ)             dev_mess.COUNT = R_BIT;
-                       else if(call_nr == WRITE)       dev_mess.COUNT = W_BIT;
-                       dev_mess.DEVICE = minor_dev;
-                       (*dp->dmap_io)(dp->dmap_driver, &dev_mess);
-
-                       /* Should do something about EINTR -> EAGAIN mapping */
                }
                return(SUSPEND);
        }
@@ -498,7 +508,7 @@ PUBLIC int dev_io(
   /* No suspend, or cancelled suspend, so I/O is over and can be cleaned up. */
   if(safe) cpf_revoke(gid);
 
-  return(dev_mess.REP_STATUS);
+  return ret;
 }
 
 /*===========================================================================*