In order to support filehandle lookup in filesystems with internal
mounts (multiple subvols in the one filesystem) reconnect_path() in
exportfs will need to find out if a given dentry is already mounted.
This can be done with the function lookup_mnt(), so export that to make
it available.
Signed-off-by: NeilBrown <neilb@xxxxxxx>
---
fs/internal.h | 1 -
fs/namespace.c | 1 +
include/linux/mount.h | 2 ++
3 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/internal.h b/fs/internal.h
index 3ce8edbaa3ca..0feb2722d2e5 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -81,7 +81,6 @@ int do_renameat2(int olddfd, struct filename *oldname, int newdfd,
/*
* namespace.c
*/
-extern struct vfsmount *lookup_mnt(const struct path *);
extern int finish_automount(struct vfsmount *, struct path *);
extern int sb_prepare_remount_readonly(struct super_block *);
diff --git a/fs/namespace.c b/fs/namespace.c
index 81b0f2b2e701..73bbdb921e24 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -662,6 +662,7 @@ struct vfsmount *lookup_mnt(const struct path *path)
rcu_read_unlock();
return m;
}
+EXPORT_SYMBOL(lookup_mnt);
static inline void lock_ns_list(struct mnt_namespace *ns)
{
diff --git a/include/linux/mount.h b/include/linux/mount.h
index 5d92a7e1a742..1d3daed88f83 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -118,6 +118,8 @@ extern unsigned int sysctl_mount_max;
extern bool path_is_mountpoint(const struct path *path);
+extern struct vfsmount *lookup_mnt(const struct path *);
+
extern void kern_unmount_array(struct vfsmount *mnt[], unsigned int num);
#endif /* _LINUX_MOUNT_H */
