beginning of transtion: ->mount()

eventual replacement for ->get_sb() - does *not* get vfsmount,
return ERR_PTR(error) or root of subtree to be mounted.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/super.c b/fs/super.c
index b9c9869165db359d018134e99e0a39e2738e6dba..00a2c9662b55ba8654e801f81a12a26445bcda94 100644 (file)
--- a/fs/super.c
+++ b/fs/super.c
@@ -918,6 +918,7 @@ struct vfsmount *
 vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data)
 {
        struct vfsmount *mnt;
+       struct dentry *root;
        char *secdata = NULL;
        int error;
 
@@ -942,9 +943,19 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void
                        goto out_free_secdata;
        }
 
-       error = type->get_sb(type, flags, name, data, mnt);
-       if (error < 0)
-               goto out_free_secdata;
+       if (type->mount) {
+               root = type->mount(type, flags, name, data);
+               if (IS_ERR(root)) {
+                       error = PTR_ERR(root);
+                       goto out_free_secdata;
+               }
+               mnt->mnt_root = root;
+               mnt->mnt_sb = root->d_sb;
+       } else {
+               error = type->get_sb(type, flags, name, data, mnt);
+               if (error < 0)
+                       goto out_free_secdata;
+       }
        BUG_ON(!mnt->mnt_sb);
        WARN_ON(!mnt->mnt_sb->s_bdi);
        mnt->mnt_sb->s_flags |= MS_BORN;

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 1c73b50e81ffbb2f67014e93fdbc0143a414b7ff..c6b474311690ee324193e02d6c4ddba24840312a 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1772,6 +1772,8 @@ struct file_system_type {
        int fs_flags;
        int (*get_sb) (struct file_system_type *, int,
                       const char *, void *, struct vfsmount *);
+       struct dentry *(*mount) (struct file_system_type *, int,
+                      const char *, void *);
        void (*kill_sb) (struct super_block *);
        struct module *owner;
        struct file_system_type * next;