kernfs: allow creating kernfs objects with arbitrary uid/gid
This change allows creating kernfs files and directories with arbitrary
uid/gid instead of always using GLOBAL_ROOT_UID/GID by extending
kernfs_create_dir_ns() and kernfs_create_file_ns() with uid/gid arguments.
The "simple" kernfs_create_file() and kernfs_create_dir() are left alone
and always create objects belonging to the global root.
When creating symlinks ownership (uid/gid) is taken from the target kernfs
object.
Co-Developed-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index ab25c8b..814643f 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -15,6 +15,7 @@
#include <linux/lockdep.h>
#include <linux/rbtree.h>
#include <linux/atomic.h>
+#include <linux/uidgid.h>
#include <linux/wait.h>
struct file;
@@ -325,12 +326,14 @@
struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent,
const char *name, umode_t mode,
+ kuid_t uid, kgid_t gid,
void *priv, const void *ns);
struct kernfs_node *kernfs_create_empty_dir(struct kernfs_node *parent,
const char *name);
struct kernfs_node *__kernfs_create_file(struct kernfs_node *parent,
- const char *name,
- umode_t mode, loff_t size,
+ const char *name, umode_t mode,
+ kuid_t uid, kgid_t gid,
+ loff_t size,
const struct kernfs_ops *ops,
void *priv, const void *ns,
struct lock_class_key *key);
@@ -415,12 +418,14 @@
static inline struct kernfs_node *
kernfs_create_dir_ns(struct kernfs_node *parent, const char *name,
- umode_t mode, void *priv, const void *ns)
+ umode_t mode, kuid_t uid, kgid_t gid,
+ void *priv, const void *ns)
{ return ERR_PTR(-ENOSYS); }
static inline struct kernfs_node *
__kernfs_create_file(struct kernfs_node *parent, const char *name,
- umode_t mode, loff_t size, const struct kernfs_ops *ops,
+ umode_t mode, kuid_t uid, kgid_t gid,
+ loff_t size, const struct kernfs_ops *ops,
void *priv, const void *ns, struct lock_class_key *key)
{ return ERR_PTR(-ENOSYS); }
@@ -498,12 +503,15 @@
kernfs_create_dir(struct kernfs_node *parent, const char *name, umode_t mode,
void *priv)
{
- return kernfs_create_dir_ns(parent, name, mode, priv, NULL);
+ return kernfs_create_dir_ns(parent, name, mode,
+ GLOBAL_ROOT_UID, GLOBAL_ROOT_GID,
+ priv, NULL);
}
static inline struct kernfs_node *
kernfs_create_file_ns(struct kernfs_node *parent, const char *name,
- umode_t mode, loff_t size, const struct kernfs_ops *ops,
+ umode_t mode, kuid_t uid, kgid_t gid,
+ loff_t size, const struct kernfs_ops *ops,
void *priv, const void *ns)
{
struct lock_class_key *key = NULL;
@@ -511,15 +519,17 @@
#ifdef CONFIG_DEBUG_LOCK_ALLOC
key = (struct lock_class_key *)&ops->lockdep_key;
#endif
- return __kernfs_create_file(parent, name, mode, size, ops, priv, ns,
- key);
+ return __kernfs_create_file(parent, name, mode, uid, gid,
+ size, ops, priv, ns, key);
}
static inline struct kernfs_node *
kernfs_create_file(struct kernfs_node *parent, const char *name, umode_t mode,
loff_t size, const struct kernfs_ops *ops, void *priv)
{
- return kernfs_create_file_ns(parent, name, mode, size, ops, priv, NULL);
+ return kernfs_create_file_ns(parent, name, mode,
+ GLOBAL_ROOT_UID, GLOBAL_ROOT_GID,
+ size, ops, priv, NULL);
}
static inline int kernfs_remove_by_name(struct kernfs_node *parent,