get rid of ->mnt_longterm
it's enough to set ->mnt_ns of internal vfsmounts to something
distinct from all struct mnt_namespace out there; then we can
just use the check for ->mnt_ns != NULL in the fast path of
mntput_no_expire()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/mount.h b/fs/mount.h
index 4ef36d9..05a2a11 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -22,7 +22,6 @@
struct vfsmount mnt;
#ifdef CONFIG_SMP
struct mnt_pcp __percpu *mnt_pcp;
- atomic_t mnt_longterm; /* how many of the refs are longterm */
#else
int mnt_count;
int mnt_writers;
@@ -49,6 +48,8 @@
int mnt_ghosts;
};
+#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
+
static inline struct mount *real_mount(struct vfsmount *mnt)
{
return container_of(mnt, struct mount, mnt);
@@ -59,6 +60,12 @@
return mnt != mnt->mnt_parent;
}
+static inline int is_mounted(struct vfsmount *mnt)
+{
+ /* neither detached nor internal? */
+ return !IS_ERR_OR_NULL(real_mount(mnt));
+}
+
extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int);
static inline void get_mnt_ns(struct mnt_namespace *ns)