Lock struct pgrp, session and sigio.

New locks are:

- pgrpsess_lock which locks the whole pgrps and sessions,
- pg_mtx which protects the pgrp members, and
- s_mtx which protects the session members.

Please refer to sys/proc.h for the coverage of these locks.

Changes on the pgrp/session interface:

- pgfind() needs the pgrpsess_lock held.

- The caller of enterpgrp() is responsible to allocate a new pgrp and
  session.

- Call enterthispgrp() in order to enter an existing pgrp.

- pgsignal() requires a pgrp lock held.

Reviewed by:	jhb, alfred
Tested on:	cvsup.jp.FreeBSD.org
		(which is a quad-CPU machine running -current)

1 files changed, 2 insertions, 1 deletions

diff --git a/sys/compat/linux/linux_file.c b/sys/compat/linux/linux_file.c
index 1dfa4a1..dd4f219 100644
--- a/sys/compat/linux/linux_file.c
+++ b/sys/compat/linux/linux_file.c
@@ -144,12 +144,13 @@ linux_open(struct thread *td, struct linux_open_args *args)
 			fo_ioctl(fp, TIOCSCTTY, (caddr_t) 0, td);
 	    fdrop(fp, td);
 	}
-    } else
+    } else {
 	PROC_UNLOCK(p);
 #ifdef DEBUG
 	if (ldebug(open))
 		printf(LMSG("open returns error %d"), error);
 #endif
+    }
     return error;
 }