LXR linux/include/linux/namei.h

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