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linux-next/include/linux/namei.h
Jan Blunck 4ac9137858 Embed a struct path into struct nameidata instead of nd->{dentry,mnt}
This is the central patch of a cleanup series. In most cases there is no good
reason why someone would want to use a dentry for itself. This series reflects
that fact and embeds a struct path into nameidata.

Together with the other patches of this series
- it enforced the correct order of getting/releasing the reference count on
  <dentry,vfsmount> pairs
- it prepares the VFS for stacking support since it is essential to have a
  struct path in every place where the stack can be traversed
- it reduces the overall code size:

without patch series:
   text    data     bss     dec     hex filename
5321639  858418  715768 6895825  6938d1 vmlinux

with patch series:
   text    data     bss     dec     hex filename
5320026  858418  715768 6894212  693284 vmlinux

This patch:

Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix cifs]
[akpm@linux-foundation.org: fix smack]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14 21:13:33 -08:00

98 lines
2.8 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;
unsigned int flags;
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 compnents" flag
* - locked when lookup done with dcache_lock held
* - dentry cache is untrusted; force a real lookup
*/
#define LOOKUP_FOLLOW 1
#define LOOKUP_DIRECTORY 2
#define LOOKUP_CONTINUE 4
#define LOOKUP_PARENT 16
#define LOOKUP_NOALT 32
#define LOOKUP_REVAL 64
/*
* Intent data
*/
#define LOOKUP_OPEN (0x0100)
#define LOOKUP_CREATE (0x0200)
#define LOOKUP_ACCESS (0x0400)
#define LOOKUP_CHDIR (0x0800)
extern int __user_walk(const char __user *, unsigned, struct nameidata *);
extern int __user_walk_fd(int dfd, const char __user *, unsigned, struct nameidata *);
#define user_path_walk(name,nd) \
__user_walk_fd(AT_FDCWD, name, LOOKUP_FOLLOW, nd)
#define user_path_walk_link(name,nd) \
__user_walk_fd(AT_FDCWD, name, 0, nd)
extern int path_lookup(const char *, unsigned, struct nameidata *);
extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
const char *, unsigned int, struct nameidata *);
extern void path_release(struct nameidata *);
extern int __user_path_lookup_open(const char __user *, unsigned lookup_flags, struct nameidata *nd, int open_flags);
extern int path_lookup_open(int dfd, const char *name, unsigned lookup_flags, struct nameidata *, int open_flags);
extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
int (*open)(struct inode *, struct file *));
extern struct file *nameidata_to_filp(struct nameidata *nd, int flags);
extern void release_open_intent(struct nameidata *);
extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
extern struct dentry *lookup_one_noperm(const char *, struct dentry *);
extern int follow_down(struct vfsmount **, struct dentry **);
extern int follow_up(struct vfsmount **, struct dentry **);
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];
}
#endif /* _LINUX_NAMEI_H */