jail: add prison_cleanup() to release resources held by a dying jail

Currently, when a jail starts dying, either by losing its last user
reference or by being explicitly killed,
osd_jail_call(...PR_METHOD_REMOVE...) is called.  Encapsulate this
into a function prison_cleanup() that can then do other cleanup.

1 files changed, 16 insertions, 4 deletions

diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c
index 187768b59608..7ef0afabe49d 100644
--- a/sys/kern/kern_jail.c
+++ b/sys/kern/kern_jail.c
@@ -143,6 +143,7 @@ static void prison_complete(void *context, int pending);
 static void prison_deref(struct prison *pr, int flags);
 static void prison_deref_kill(struct prison *pr, struct prisonlist *freeprison);
 static int prison_lock_xlock(struct prison *pr, int flags);
+static void prison_cleanup(struct prison *pr);
 static void prison_free_not_last(struct prison *pr);
 static void prison_proc_free_not_last(struct prison *pr);
 static void prison_set_allow_locked(struct prison *pr, unsigned flag,
@@ -2994,8 +2995,7 @@ prison_deref(struct prison *pr, int flags)
 					pr->pr_state = PRISON_STATE_DYING;
 					mtx_unlock(&pr->pr_mtx);
 					flags &= ~PD_LOCKED;
-					(void)osd_jail_call(pr,
-					    PR_METHOD_REMOVE, NULL);
+					prison_cleanup(pr);
 				}
 			}
 		}
@@ -3150,7 +3150,7 @@ prison_deref_kill(struct prison *pr, struct prisonlist *freeprison)
 		}
 		if (!(cpr->pr_flags & PR_REMOVE))
 			continue;
-		(void)osd_jail_call(cpr, PR_METHOD_REMOVE, NULL);
+		prison_cleanup(cpr);
 		mtx_lock(&cpr->pr_mtx);
 		cpr->pr_flags &= ~PR_REMOVE;
 		if (cpr->pr_flags & PR_PERSIST) {
@@ -3186,7 +3186,7 @@ prison_deref_kill(struct prison *pr, struct prisonlist *freeprison)
 	if (rpr != NULL)
 		LIST_REMOVE(rpr, pr_sibling);
 
-	(void)osd_jail_call(pr, PR_METHOD_REMOVE, NULL);
+	prison_cleanup(pr);
 	mtx_lock(&pr->pr_mtx);
 	if (pr->pr_flags & PR_PERSIST) {
 		pr->pr_flags &= ~PR_PERSIST;
@@ -3233,6 +3233,18 @@ prison_lock_xlock(struct prison *pr, int flags)
 }
 
 /*
+ * Release a prison's resources when it starts dying (when the last user
+ * reference is dropped, or when it is killed).
+ */
+static void
+prison_cleanup(struct prison *pr)
+{
+	sx_assert(&allprison_lock, SA_XLOCKED);
+	mtx_assert(&pr->pr_mtx, MA_NOTOWNED);
+	(void)osd_jail_call(pr, PR_METHOD_REMOVE, NULL);
+}
+
+/*
  * Set or clear a permission bit in the pr_allow field, passing restrictions
  * (cleared permission) down to child jails.
  */