1fa1e7f615
Since the commit below which added O_PATH support to the *at() calls, the
error return for readlink/readlinkat for the empty pathname has switched
from ENOENT to EINVAL:
commit 65cfc67223
Author: Al Viro <viro@zeniv.linux.org.uk>
Date: Sun Mar 13 15:56:26 2011 -0400
readlinkat(), fchownat() and fstatat() with empty relative pathnames
This is both unexpected for userspace and makes readlink/readlinkat
inconsistant with all other interfaces; and inconsistant with our stated
return for these pathnames.
As the readlinkat call does not have a flags parameter we cannot use the
AT_EMPTY_PATH approach used in the other calls. Therefore expose whether
the original path is infact entry via a new user_path_at_empty() path
lookup function. Use this to determine whether to default to EINVAL or
ENOENT for failures.
Addresses http://bugs.launchpad.net/bugs/817187
[akpm@linux-foundation.org: remove unused getname_flags()]
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
113 lines
3.0 KiB
C
113 lines
3.0 KiB
C
#ifndef _LINUX_NAMEI_H
|
|
#define _LINUX_NAMEI_H
|
|
|
|
#include <linux/dcache.h>
|
|
#include <linux/linkage.h>
|
|
#include <linux/path.h>
|
|
|
|
struct vfsmount;
|
|
|
|
struct open_intent {
|
|
int flags;
|
|
int create_mode;
|
|
struct file *file;
|
|
};
|
|
|
|
enum { MAX_NESTED_LINKS = 8 };
|
|
|
|
struct nameidata {
|
|
struct path path;
|
|
struct qstr last;
|
|
struct path root;
|
|
struct inode *inode; /* path.dentry.d_inode */
|
|
unsigned int flags;
|
|
unsigned seq;
|
|
int last_type;
|
|
unsigned depth;
|
|
char *saved_names[MAX_NESTED_LINKS + 1];
|
|
|
|
/* Intent data */
|
|
union {
|
|
struct open_intent open;
|
|
} intent;
|
|
};
|
|
|
|
/*
|
|
* Type of the last component on LOOKUP_PARENT
|
|
*/
|
|
enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
|
|
|
|
/*
|
|
* The bitmask for a lookup event:
|
|
* - follow links at the end
|
|
* - require a directory
|
|
* - ending slashes ok even for nonexistent files
|
|
* - internal "there are more path components" flag
|
|
* - dentry cache is untrusted; force a real lookup
|
|
* - suppress terminal automount
|
|
*/
|
|
#define LOOKUP_FOLLOW 0x0001
|
|
#define LOOKUP_DIRECTORY 0x0002
|
|
#define LOOKUP_AUTOMOUNT 0x0004
|
|
|
|
#define LOOKUP_PARENT 0x0010
|
|
#define LOOKUP_REVAL 0x0020
|
|
#define LOOKUP_RCU 0x0040
|
|
|
|
/*
|
|
* Intent data
|
|
*/
|
|
#define LOOKUP_OPEN 0x0100
|
|
#define LOOKUP_CREATE 0x0200
|
|
#define LOOKUP_EXCL 0x0400
|
|
#define LOOKUP_RENAME_TARGET 0x0800
|
|
|
|
#define LOOKUP_JUMPED 0x1000
|
|
#define LOOKUP_ROOT 0x2000
|
|
#define LOOKUP_EMPTY 0x4000
|
|
|
|
extern int user_path_at(int, const char __user *, unsigned, struct path *);
|
|
extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
|
|
|
|
#define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path)
|
|
#define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path)
|
|
#define user_path_dir(name, path) \
|
|
user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path)
|
|
|
|
extern int kern_path(const char *, unsigned, struct path *);
|
|
|
|
extern struct dentry *kern_path_create(int, const char *, struct path *, int);
|
|
extern struct dentry *user_path_create(int, const char __user *, struct path *, int);
|
|
extern int kern_path_parent(const char *, struct nameidata *);
|
|
extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
|
|
const char *, unsigned int, struct path *);
|
|
|
|
extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
|
|
int (*open)(struct inode *, struct file *));
|
|
|
|
extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
|
|
|
|
extern int follow_down_one(struct path *);
|
|
extern int follow_down(struct path *);
|
|
extern int follow_up(struct path *);
|
|
|
|
extern struct dentry *lock_rename(struct dentry *, struct dentry *);
|
|
extern void unlock_rename(struct dentry *, struct dentry *);
|
|
|
|
static inline void nd_set_link(struct nameidata *nd, char *path)
|
|
{
|
|
nd->saved_names[nd->depth] = path;
|
|
}
|
|
|
|
static inline char *nd_get_link(struct nameidata *nd)
|
|
{
|
|
return nd->saved_names[nd->depth];
|
|
}
|
|
|
|
static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
|
|
{
|
|
((char *) name)[min(len, maxlen)] = '\0';
|
|
}
|
|
|
|
#endif /* _LINUX_NAMEI_H */
|