LXR linux/include/linux/namei.h

   1#ifndef _LINUX_NAMEI_H
   2#define _LINUX_NAMEI_H
   3
   4#include <linux/dcache.h>
   5#include <linux/linkage.h>
   6#include <linux/path.h>
   7
   8struct vfsmount;
   9
  10struct open_intent {
  11        int     flags;
  12        int     create_mode;
  13        struct file *file;
  14};
  15
  16enum { MAX_NESTED_LINKS = 8 };
  17
  18struct nameidata {
  19        struct path     path;
  20        struct qstr     last;
  21        unsigned int    flags;
  22        int             last_type;
  23        unsigned        depth;
  24        char *saved_names[MAX_NESTED_LINKS + 1];
  25
  26        /* Intent data */
  27        union {
  28                struct open_intent open;
  29        } intent;
  30};
  31
  32/*
  33 * Type of the last component on LOOKUP_PARENT
  34 */
  35enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
  36
  37/*
  38 * The bitmask for a lookup event:
  39 *  - follow links at the end
  40 *  - require a directory
  41 *  - ending slashes ok even for nonexistent files
  42 *  - internal "there are more path compnents" flag
  43 *  - locked when lookup done with dcache_lock held
  44 *  - dentry cache is untrusted; force a real lookup
  45 */
  46#define LOOKUP_FOLLOW            1
  47#define LOOKUP_DIRECTORY         2
  48#define LOOKUP_CONTINUE          4
  49#define LOOKUP_PARENT           16
  50#define LOOKUP_NOALT            32
  51#define LOOKUP_REVAL            64
  52/*
  53 * Intent data
  54 */
  55#define LOOKUP_OPEN             (0x0100)
  56#define LOOKUP_CREATE           (0x0200)
  57#define LOOKUP_ACCESS           (0x0400)
  58#define LOOKUP_CHDIR            (0x0800)
  59
  60extern int __user_walk(const char __user *, unsigned, struct nameidata *);
  61extern int __user_walk_fd(int dfd, const char __user *, unsigned, struct nameidata *);
  62#define user_path_walk(name,nd) \
  63        __user_walk_fd(AT_FDCWD, name, LOOKUP_FOLLOW, nd)
  64#define user_path_walk_link(name,nd) \
  65        __user_walk_fd(AT_FDCWD, name, 0, nd)
  66extern int path_lookup(const char *, unsigned, struct nameidata *);
  67extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
  68                           const char *, unsigned int, struct nameidata *);
  69
  70extern int __user_path_lookup_open(const char __user *, unsigned lookup_flags, struct nameidata *nd, int open_flags);
  71extern int path_lookup_open(int dfd, const char *name, unsigned lookup_flags, struct nameidata *, int open_flags);
  72extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
  73                int (*open)(struct inode *, struct file *));
  74extern struct file *nameidata_to_filp(struct nameidata *nd, int flags);
  75extern void release_open_intent(struct nameidata *);
  76
  77extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
  78extern struct dentry *lookup_one_noperm(const char *, struct dentry *);
  79
  80extern int follow_down(struct vfsmount **, struct dentry **);
  81extern int follow_up(struct vfsmount **, struct dentry **);
  82
  83extern struct dentry *lock_rename(struct dentry *, struct dentry *);
  84extern void unlock_rename(struct dentry *, struct dentry *);
  85
  86static inline void nd_set_link(struct nameidata *nd, char *path)
  87{
  88        nd->saved_names[nd->depth] = path;
  89}
  90
  91static inline char *nd_get_link(struct nameidata *nd)
  92{
  93        return nd->saved_names[nd->depth];
  94}
  95
  96#endif /* _LINUX_NAMEI_H */
  97