svn commit: r259663 - head/sys/kern

[Gleb Smirnoff]

Author: glebius
Date: Fri Dec 20 19:45:51 2013
New Revision: 259663
URL: http://svnweb.freebsd.org/changeset/base/259663

Log:
  Move list of ttys handling from the allocating procedures, to the
  device creation stage. A device creation can fail, and in that case
  an entry already on the list will be freed.
  
  Sponsored by:	Nginx, Inc.

Modified:
  head/sys/kern/tty.c

Modified: head/sys/kern/tty.c
==============================================================================
--- head/sys/kern/tty.c	Fri Dec 20 19:44:29 2013	(r259662)
+++ head/sys/kern/tty.c	Fri Dec 20 19:45:51 2013	(r259663)
@@ -1007,11 +1007,6 @@ tty_alloc_mutex(struct ttydevsw *tsw, vo
 	knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
 	knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
 
-	sx_xlock(&tty_list_sx);
-	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
-	tty_list_count++;
-	sx_xunlock(&tty_list_sx);
-
 	return (tp);
 }
 
@@ -1020,11 +1015,6 @@ tty_dealloc(void *arg)
 {
 	struct tty *tp = arg;
 
-	sx_xlock(&tty_list_sx);
-	TAILQ_REMOVE(&tty_list, tp, t_list);
-	tty_list_count--;
-	sx_xunlock(&tty_list_sx);
-
 	/* Make sure we haven't leaked buffers. */
 	MPASS(ttyinq_getsize(&tp->t_inq) == 0);
 	MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
@@ -1065,6 +1055,11 @@ tty_rel_free(struct tty *tp)
 	tp->t_dev = NULL;
 	tty_unlock(tp);
 
+	sx_xlock(&tty_list_sx);
+	TAILQ_REMOVE(&tty_list, tp, t_list);
+	tty_list_count--;
+	sx_xunlock(&tty_list_sx);
+
 	if (dev != NULL)
 		destroy_dev_sched_cb(dev, tty_dealloc, tp);
 }
@@ -1279,6 +1274,11 @@ tty_makedevf(struct tty *tp, struct ucre
 		}
 	}
 
+	sx_xlock(&tty_list_sx);
+	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
+	tty_list_count++;
+	sx_xunlock(&tty_list_sx);
+
 	return (0);
 
 fail: