X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fpnode.c;h=8d5f392ec3d39fa12a025ec3a6045b7ef8f790a4;hb=84814d642a4f1f294bd675ab11aae1ca54c6cedb;hp=aeeec8ba8dd28b9ac4a77ee513fb23423b55d458;hpb=9676f0c6389b62bd6b24d77d4b3abdbcfa32d0f2;p=safe%2Fjmp%2Flinux-2.6

diff --git a/fs/pnode.c b/fs/pnode.c
index aeeec8b..8d5f392 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -6,9 +6,10 @@
  *	Author : Ram Pai (linuxram@us.ibm.com)
  *
  */
-#include <linux/namespace.h>
+#include <linux/mnt_namespace.h>
 #include <linux/mount.h>
 #include <linux/fs.h>
+#include "internal.h"
 #include "pnode.h"
 
 /* return the next shared peer mount of @p */
@@ -27,6 +28,57 @@ static inline struct vfsmount *next_slave(struct vfsmount *p)
 	return list_entry(p->mnt_slave.next, struct vfsmount, mnt_slave);
 }
 
+/*
+ * Return true if path is reachable from root
+ *
+ * namespace_sem is held, and mnt is attached
+ */
+static bool is_path_reachable(struct vfsmount *mnt, struct dentry *dentry,
+			 const struct path *root)
+{
+	while (mnt != root->mnt && mnt->mnt_parent != mnt) {
+		dentry = mnt->mnt_mountpoint;
+		mnt = mnt->mnt_parent;
+	}
+	return mnt == root->mnt && is_subdir(dentry, root->dentry);
+}
+
+static struct vfsmount *get_peer_under_root(struct vfsmount *mnt,
+					    struct mnt_namespace *ns,
+					    const struct path *root)
+{
+	struct vfsmount *m = mnt;
+
+	do {
+		/* Check the namespace first for optimization */
+		if (m->mnt_ns == ns && is_path_reachable(m, m->mnt_root, root))
+			return m;
+
+		m = next_peer(m);
+	} while (m != mnt);
+
+	return NULL;
+}
+
+/*
+ * Get ID of closest dominating peer group having a representative
+ * under the given root.
+ *
+ * Caller must hold namespace_sem
+ */
+int get_dominating_id(struct vfsmount *mnt, const struct path *root)
+{
+	struct vfsmount *m;
+
+	for (m = mnt->mnt_master; m != NULL; m = m->mnt_master) {
+		struct vfsmount *d = get_peer_under_root(m, mnt->mnt_ns, root);
+		if (d)
+			return d->mnt_group_id;
+	}
+
+	return 0;
+}
+
 static int do_make_slave(struct vfsmount *mnt)
 {
 	struct vfsmount *peer_mnt = mnt, *master = mnt->mnt_master;
@@ -45,7 +97,11 @@ static int do_make_slave(struct vfsmount *mnt)
 		if (peer_mnt == mnt)
 			peer_mnt = NULL;
 	}
+	if (IS_MNT_SHARED(mnt) && list_empty(&mnt->mnt_share))
+		mnt_release_group_id(mnt);
+
 	list_del_init(&mnt->mnt_share);
+	mnt->mnt_group_id = 0;
 
 	if (peer_mnt)
 		master = peer_mnt;
@@ -53,14 +109,13 @@ static int do_make_slave(struct vfsmount *mnt)
 	if (master) {
 		list_for_each_entry(slave_mnt, &mnt->mnt_slave_list, mnt_slave)
 			slave_mnt->mnt_master = master;
-		list_del(&mnt->mnt_slave);
-		list_add(&mnt->mnt_slave, &master->mnt_slave_list);
+		list_move(&mnt->mnt_slave, &master->mnt_slave_list);
 		list_splice(&mnt->mnt_slave_list, master->mnt_slave_list.prev);
 		INIT_LIST_HEAD(&mnt->mnt_slave_list);
 	} else {
 		struct list_head *p = &mnt->mnt_slave_list;
 		while (!list_empty(p)) {
-                        slave_mnt = list_entry(p->next,
+                        slave_mnt = list_first_entry(p,
 					struct vfsmount, mnt_slave);
 			list_del_init(&slave_mnt->mnt_slave);
 			slave_mnt->mnt_master = NULL;
@@ -68,7 +123,6 @@ static int do_make_slave(struct vfsmount *mnt)
 	}
 	mnt->mnt_master = master;
 	CLEAR_MNT_SHARED(mnt);
-	INIT_LIST_HEAD(&mnt->mnt_slave_list);
 	return 0;
 }
 
@@ -84,6 +138,8 @@ void change_mnt_propagation(struct vfsmount *mnt, int type)
 		mnt->mnt_master = NULL;
 		if (type == MS_UNBINDABLE)
 			mnt->mnt_flags |= MNT_UNBINDABLE;
+		else
+			mnt->mnt_flags &= ~MNT_UNBINDABLE;
 	}
 }
 
@@ -103,7 +159,7 @@ static struct vfsmount *propagation_next(struct vfsmount *m,
 		struct vfsmount *next;
 		struct vfsmount *master = m->mnt_master;
 
-		if ( master == origin->mnt_master ) {
+		if (master == origin->mnt_master) {
 			next = next_peer(m);
 			return ((next == origin) ? NULL : next);
 		} else if (m->mnt_slave.next != &master->mnt_slave_list)
@@ -130,7 +186,7 @@ static struct vfsmount *get_source(struct vfsmount *dest,
 {
 	struct vfsmount *p_last_src = NULL;
 	struct vfsmount *p_last_dest = NULL;
-	*type = CL_PROPAGATION;;
+	*type = CL_PROPAGATION;
 
 	if (IS_MNT_SHARED(dest))
 		*type |= CL_MAKE_SHARED;
@@ -210,8 +266,7 @@ int propagate_mnt(struct vfsmount *dest_mnt, struct dentry *dest_dentry,
 out:
 	spin_lock(&vfsmount_lock);
 	while (!list_empty(&tmp_list)) {
-		child = list_entry(tmp_list.next, struct vfsmount, mnt_hash);
-		list_del_init(&child->mnt_hash);
+		child = list_first_entry(&tmp_list, struct vfsmount, mnt_hash);
 		umount_tree(child, 0, &umount_list);
 	}
 	spin_unlock(&vfsmount_lock);
@@ -224,7 +279,7 @@ out:
  */
 static inline int do_refcount_check(struct vfsmount *mnt, int count)
 {
-	int mycount = atomic_read(&mnt->mnt_count);
+	int mycount = atomic_read(&mnt->mnt_count) - mnt->mnt_ghosts;
 	return (mycount > count);
 }
 
@@ -283,10 +338,8 @@ static void __propagate_umount(struct vfsmount *mnt)
 		 * umount the child only if the child has no
 		 * other children
 		 */
-		if (child && list_empty(&child->mnt_mounts)) {
-			list_del(&child->mnt_hash);
-			list_add_tail(&child->mnt_hash, &mnt->mnt_hash);
-		}
+		if (child && list_empty(&child->mnt_mounts))
+			list_move_tail(&child->mnt_hash, &mnt->mnt_hash);
 	}
 }