#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 */
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;
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;
}
mnt->mnt_master = master;
CLEAR_MNT_SHARED(mnt);
- INIT_LIST_HEAD(&mnt->mnt_slave_list);
return 0;
}
mnt->mnt_master = NULL;
if (type == MS_UNBINDABLE)
mnt->mnt_flags |= MNT_UNBINDABLE;
+ else
+ mnt->mnt_flags &= ~MNT_UNBINDABLE;
}
}
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);
*/
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);
}