From a013e0afcbb44052a86a7977277d669d8883b7e7 Mon Sep 17 00:00:00 2001
From: jamie <jamie@FreeBSD.org>
Date: Wed, 27 May 2009 14:11:23 +0000
Subject: Add hierarchical jails.  A jail may further virtualize its
 environment by creating a child jail, which is visible to that jail and to
 any parent jails.  Child jails may be restricted more than their parents, but
 never less.  Jail names reflect this hierarchy, being MIB-style dot-separated
 strings.

Every thread now points to a jail, the default being prison0, which
contains information about the physical system.  Prison0's root
directory is the same as rootvnode; its hostname is the same as the
global hostname, and its securelevel replaces the global securelevel.
Note that the variable "securelevel" has actually gone away, which
should not cause any problems for code that properly uses
securelevel_gt() and securelevel_ge().

Some jail-related permissions that were kept in global variables and
set via sysctls are now per-jail settings.  The sysctls still exist for
backward compatibility, used only by the now-deprecated jail(2) system
call.

Approved by:	bz (mentor)
---
 sys/kern/kern_descrip.c | 36 ++++++++++++++++++++++++++++++------
 1 file changed, 30 insertions(+), 6 deletions(-)

(limited to 'sys/kern/kern_descrip.c')

diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index 4553bb4..c93d05a 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -2416,24 +2416,25 @@ dupfdopen(struct thread *td, struct filedesc *fdp, int indx, int dfd, int mode,
 }
 
 /*
- * Scan all active processes to see if any of them have a current or root
- * directory of `olddp'. If so, replace them with the new mount point.
+ * Scan all active processes and prisons to see if any of them have a current
+ * or root directory of `olddp'. If so, replace them with the new mount point.
  */
 void
 mountcheckdirs(struct vnode *olddp, struct vnode *newdp)
 {
 	struct filedesc *fdp;
+	struct prison *pr;
 	struct proc *p;
 	int nrele;
 
 	if (vrefcnt(olddp) == 1)
 		return;
+	nrele = 0;
 	sx_slock(&allproc_lock);
 	FOREACH_PROC_IN_SYSTEM(p) {
 		fdp = fdhold(p);
 		if (fdp == NULL)
 			continue;
-		nrele = 0;
 		FILEDESC_XLOCK(fdp);
 		if (fdp->fd_cdir == olddp) {
 			vref(newdp);
@@ -2445,17 +2446,40 @@ mountcheckdirs(struct vnode *olddp, struct vnode *newdp)
 			fdp->fd_rdir = newdp;
 			nrele++;
 		}
+		if (fdp->fd_jdir == olddp) {
+			vref(newdp);
+			fdp->fd_jdir = newdp;
+			nrele++;
+		}
 		FILEDESC_XUNLOCK(fdp);
 		fddrop(fdp);
-		while (nrele--)
-			vrele(olddp);
 	}
 	sx_sunlock(&allproc_lock);
 	if (rootvnode == olddp) {
-		vrele(rootvnode);
 		vref(newdp);
 		rootvnode = newdp;
+		nrele++;
+	}
+	mtx_lock(&prison0.pr_mtx);
+	if (prison0.pr_root == olddp) {
+		vref(newdp);
+		prison0.pr_root = newdp;
+		nrele++;
+	}
+	mtx_unlock(&prison0.pr_mtx);
+	sx_slock(&allprison_lock);
+	TAILQ_FOREACH(pr, &allprison, pr_list) {
+		mtx_lock(&pr->pr_mtx);
+		if (pr->pr_root == olddp) {
+			vref(newdp);
+			pr->pr_root = newdp;
+			nrele++;
+		}
+		mtx_unlock(&pr->pr_mtx);
 	}
+	sx_sunlock(&allprison_lock);
+	while (nrele--)
+		vrele(olddp);
 }
 
 struct filedesc_to_leader *
-- 
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