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        struct path     root;
  22        unsigned int    flags;
  23        int             last_type;
  24        unsigned        depth;
  25        char *saved_names[MAX_NESTED_LINKS + 1];
  26
  27        /* Intent data */
  28        union {
  29                struct open_intent open;
  30        } intent;
  31};
  32
  33/*
  34 * Type of the last component on LOOKUP_PARENT
  35 */
  36enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
  37
  38/*
  39 * The bitmask for a lookup event:
  40 *  - follow links at the end
  41 *  - require a directory
  42 *  - ending slashes ok even for nonexistent files
  43 *  - internal "there are more path components" flag
  44 *  - locked when lookup done with dcache_lock held
  45 *  - dentry cache is untrusted; force a real lookup
  46 */
  47#define LOOKUP_FOLLOW            1
  48#define LOOKUP_DIRECTORY         2
  49#define LOOKUP_CONTINUE          4
  50#define LOOKUP_PARENT           16
  51#define LOOKUP_REVAL            64
  52/*
  53 * Intent data
  54 */
  55#define LOOKUP_OPEN             0x0100
  56#define LOOKUP_CREATE           0x0200
  57#define LOOKUP_EXCL             0x0400
  58#define LOOKUP_RENAME_TARGET    0x0800
  59
  60extern int user_path_at(int, const char __user *, unsigned, struct path *);
  61
  62#define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path)
  63#define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path)
  64#define user_path_dir(name, path) \
  65        user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path)
  66
  67extern int kern_path(const char *, unsigned, struct path *);
  68
  69extern int path_lookup(const char *, unsigned, struct nameidata *);
  70extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
  71                           const char *, unsigned int, struct nameidata *);
  72
  73extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
  74                int (*open)(struct inode *, struct file *));
  75extern struct file *nameidata_to_filp(struct nameidata *nd, int flags);
  76extern void release_open_intent(struct nameidata *);
  77
  78extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
  79extern struct dentry *lookup_one_noperm(const char *, struct dentry *);
  80
  81extern int follow_down(struct path *);
  82extern int follow_up(struct path *);
  83
  84extern struct dentry *lock_rename(struct dentry *, struct dentry *);
  85extern void unlock_rename(struct dentry *, struct dentry *);
  86
  87static inline void nd_set_link(struct nameidata *nd, char *path)
  88{
  89        nd->saved_names[nd->depth] = path;
  90}
  91
  92static inline char *nd_get_link(struct nameidata *nd)
  93{
  94        return nd->saved_names[nd->depth];
  95}
  96
  97static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
  98{
  99        ((char *) name)[min(len, maxlen)] = '\0';
 100}
 101
 102#endif /* _LINUX_NAMEI_H */
 103