FS understanding revives and selects as alerts (new notifies)

servers/fs/device.c

@@ -5,6 +5,7 @@
  *   dev_open:   FS opens a device
  *   dev_close:  FS closes a device
  *   dev_io:	 FS does a read or write on a device
+ *   dev_status: FS processes callback request alert
  *   gen_opcl:   generic call to a task to perform an open/close
  *   gen_io:     generic call to a task to perform an I/O operation
  *   no_dev:     open/close processing for devices that don't exist
@@ -62,6 +63,47 @@ dev_t dev;			/* device to close */
   (void) (*dmap[(dev >> MAJOR) & BYTE].dmap_opcl)(DEV_CLOSE, dev, 0, 0);
 }
 
+/*===========================================================================*
+ *				dev_status					*
+ *===========================================================================*/
+PUBLIC void dev_status(message *m)
+{
+	message st;
+	int d, get_more = 1;
+
+	for(d = 0; d < NR_DEVICES; d++)
+		if(dmap[d].dmap_driver == m->m_source)
+			break;
+
+	if(d >= NR_DEVICES)
+		return;
+
+	do {
+		int r;
+		st.m_type = DEV_STATUS;
+		if((r=sendrec(m->m_source, &st)) != OK)
+			panic(__FILE__,"couldn't sendrec for DEV_STATUS", r);
+
+		switch(st.m_type) {
+			case DEV_REVIVE:
+				revive(st.REP_PROC_NR, st.REP_STATUS);
+				break;
+			case DEV_IO_READY:
+				select_notified(d, st.DEV_MINOR, st.DEV_SEL_OPS);
+				break;
+			default:
+				printf("FS: unrecognized reply %d to DEV_STATUS\n", st.m_type);
+				/* Fall through. */
+			case DEV_NO_STATUS:
+				get_more = 0;
+				break;
+		}
+	} while(get_more);
+
+
+	return;
+}
+
 /*===========================================================================*
  *				dev_io					     *
  *===========================================================================*/
@@ -274,8 +316,8 @@ message *mess_ptr;		/* pointer to message for task */
 
   proc_nr = mess_ptr->PROC_NR;
   if (! isokprocnr(proc_nr)) {
-      printf("FS: warning, got illegal process number from %d.\n",
+      printf("FS: warning, got illegal process number (%d) from %d\n",
-          mess_ptr->PROC_NR);
+          mess_ptr->PROC_NR, mess_ptr->m_source);
       return;
   }
 
@@ -320,11 +362,6 @@ message *mess_ptr;		/* pointer to message for task */
   	/* Did the process we did the sendrec() for get a result? */
   	if (mess_ptr->REP_PROC_NR == proc_nr) {
   		break;
-  	}
-
-	if(mess_ptr->m_type == DEV_SELECTED) {
-		/* select() became possible.. This can happen. */
-		select_notified(mess_ptr);
 	} else if(mess_ptr->m_type == REVIVE) {
 		/* Otherwise it should be a REVIVE. */
 		revive(mess_ptr->REP_PROC_NR, mess_ptr->REP_STATUS);
@@ -333,7 +370,7 @@ message *mess_ptr;		/* pointer to message for task */
 		"fs: strange device reply from %d, type = %d, proc = %d (2)\n",
 			mess_ptr->m_source,
 			mess_ptr->m_type, mess_ptr->REP_PROC_NR);
-		continue;	/* XXX should this be a continue?? */
+		continue; /* XXX ? */
 	}
 
 	r = receive(task_nr, mess_ptr);
@@ -437,3 +474,4 @@ int flags;			/* mode bits and flags */
   }
   return(dev_mess.REP_STATUS);
 }
+

servers/fs/main.c

@@ -74,8 +74,10 @@ PUBLIC void main()
         	 */
         	fs_expire_timers(m_in.NOTIFY_TIMESTAMP);
         } else if (call_nr == DEV_SELECTED) {
-        	/* Device notify()s us of fd that has become usable. */
+        	printf("Old select device callback received - ignored\n");
-        	select_notified(&m_in);
+        } else if ((call_nr & NOTIFY_MESSAGE)) {
+        	/* Device notifies (alert()s) us of an event. */
+        	dev_status(&m_in);
         } else {
 		/* Call the internal function that does the work. */
 		if (call_nr < 0 || call_nr >= NCALLS) { 

servers/fs/proto.h

@@ -41,6 +41,7 @@ _PROTOTYPE( int clone_opcl, (int op, Dev_t dev, int proc, int flags)	);
 _PROTOTYPE( void ctty_io, (int task_nr, message *mess_ptr)		);
 _PROTOTYPE( int do_ioctl, (void)					);
 _PROTOTYPE( int do_setsid, (void)					);
+_PROTOTYPE( void dev_status, (message *)					);
 
 /* dmp.c */
 _PROTOTYPE( int do_fkey_pressed, (void)					);
@@ -185,7 +186,7 @@ _PROTOTYPE( int select_callback, (struct filp *, int ops)		);
 _PROTOTYPE( void select_forget, (int fproc)				);
 _PROTOTYPE( void select_timeout_check, (timer_t *)			);
 _PROTOTYPE( void init_select, (void)					);
-_PROTOTYPE( int select_notified, (message *)				);
+_PROTOTYPE( int select_notified, (int major, int minor, int ops)				);
 
 /* timers.c */
 _PROTOTYPE( void fs_set_timer, (timer_t *tp, int delta, tmr_func_t watchdog, int arg));

servers/fs/select.c

@@ -17,7 +17,7 @@
   * make select cancel disappearing fp's
   */
 
-#define DEBUG_SELECT 0
+#define DEBUG_SELECT 1
 
 #include "fs.h"
 #include "dmap.h"
@@ -553,47 +553,49 @@ PUBLIC int select_callback(struct filp *fp, int ops)
 /*===========================================================================*
  *				int select_notified			     *
  *===========================================================================*/
-PUBLIC int select_notified(message *m)
+PUBLIC int select_notified(int major, int minor, int selected_ops)
 {
-	int s, f, d, t;
+	int s, f, t;
 
-	for(d = 0; d < NR_DEVICES; d++)
+#if DEBUG_SELECT
-		if(dmap[d].dmap_driver == m->m_source)
+	printf("select callback: %d, %d: %d\n", major, minor, selected_ops);
-			break;
+#endif
-
-	if(d >= NR_DEVICES)
-		return OK;
 
 	for(t = 0; t < SEL_FDS; t++)
-		if(!fdtypes[t].select_match && fdtypes[t].select_major == d)
+		if(!fdtypes[t].select_match && fdtypes[t].select_major == major)
 		    	break;
 
-	if(t >= SEL_FDS)
+	if(t >= SEL_FDS) {
+#if DEBUG_SELECT
+		printf("select callback: no fdtype found for device %d\n", major);
+#endif
 		return OK;
+	}
 
 	/* We have a select callback from major device no.
 	 * d, which corresponds to our select type t.
 	 */
 
 	for(s = 0; s < MAXSELECTS; s++) {
-		int line, ops;
+		int s_minor, ops;
 		if(!selecttab[s].requestor)
 			continue;
 		for(f = 0; f < selecttab[s].nfds; f++) {
 			if(!selecttab[s].filps[f] ||
-			   !select_major_match(d, selecttab[s].filps[f]))
+			   !select_major_match(major, selecttab[s].filps[f]))
 			   	continue;
 			ops = tab2ops(f, &selecttab[s]);
-			line = selecttab[s].filps[f]->filp_ino->i_zone[0] & BYTE;
+			s_minor = selecttab[s].filps[f]->filp_ino->i_zone[0] & BYTE;
-			if((line == m->NOTIFY_ARG) &&
+			if((s_minor == minor) &&
-				(m->NOTIFY_FLAGS & ops)) {
+				(selected_ops & ops)) {
-				select_callback(selecttab[s].filps[f], ops);
+				select_callback(selecttab[s].filps[f], (selected_ops & ops));
 			}
 		}
 	}
 
 	return OK;
 }
+
 /*===========================================================================*
  *				init_select  				     *
  *===========================================================================*/