mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-28 12:25:31 +00:00
a6c6065511
Current code returns EXDEV when a directory would need to be copied up to move. We could copy up the directory tree in this case, but there's another, simpler solution: point to old lower directory from moved upper directory. This is achieved with a "trusted.overlay.redirect" xattr storing the path relative to the root of the overlay. After such attribute has been set, the directory can be moved without further actions required. This is a backward incompatible feature, old kernels won't be able to correctly mount an overlay containing redirected directories. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
54 lines
1.2 KiB
C
54 lines
1.2 KiB
C
/*
|
|
*
|
|
* Copyright (C) 2011 Novell Inc.
|
|
* Copyright (C) 2016 Red Hat, Inc.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License version 2 as published by
|
|
* the Free Software Foundation.
|
|
*/
|
|
|
|
struct ovl_config {
|
|
char *lowerdir;
|
|
char *upperdir;
|
|
char *workdir;
|
|
bool default_permissions;
|
|
bool redirect_dir;
|
|
};
|
|
|
|
/* private information held for overlayfs's superblock */
|
|
struct ovl_fs {
|
|
struct vfsmount *upper_mnt;
|
|
unsigned numlower;
|
|
struct vfsmount **lower_mnt;
|
|
struct dentry *workdir;
|
|
long namelen;
|
|
/* pathnames of lower and upper dirs, for show_options */
|
|
struct ovl_config config;
|
|
/* creds of process who forced instantiation of super block */
|
|
const struct cred *creator_cred;
|
|
};
|
|
|
|
/* private information held for every overlayfs dentry */
|
|
struct ovl_entry {
|
|
struct dentry *__upperdentry;
|
|
struct ovl_dir_cache *cache;
|
|
union {
|
|
struct {
|
|
u64 version;
|
|
const char *redirect;
|
|
bool opaque;
|
|
};
|
|
struct rcu_head rcu;
|
|
};
|
|
unsigned numlower;
|
|
struct path lowerstack[];
|
|
};
|
|
|
|
struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
|
|
|
|
static inline struct dentry *ovl_upperdentry_dereference(struct ovl_entry *oe)
|
|
{
|
|
return lockless_dereference(oe->__upperdentry);
|
|
}
|