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        struct inode    *inode; /* path.dentry.d_inode */
  23        unsigned int    flags;
  24        unsigned        seq;
  25        int             last_type;
  26        unsigned        depth;
  27        char *saved_names[MAX_NESTED_LINKS + 1];
  28
  29        /* Intent data */
  30        union {
  31                struct open_intent open;
  32        } intent;
  33};
  34
  35/*
  36 * Type of the last component on LOOKUP_PARENT
  37 */
  38enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
  39
  40/*
  41 * The bitmask for a lookup event:
  42 *  - follow links at the end
  43 *  - require a directory
  44 *  - ending slashes ok even for nonexistent files
  45 *  - internal "there are more path components" flag
  46 *  - dentry cache is untrusted; force a real lookup
  47 *  - suppress terminal automount
  48 */
  49#define LOOKUP_FOLLOW           0x0001
  50#define LOOKUP_DIRECTORY        0x0002
  51#define LOOKUP_CONTINUE         0x0004
  52
  53#define LOOKUP_PARENT           0x0010
  54#define LOOKUP_REVAL            0x0020
  55#define LOOKUP_RCU              0x0040
  56#define LOOKUP_NO_AUTOMOUNT     0x0080
  57/*
  58 * Intent data
  59 */
  60#define LOOKUP_OPEN             0x0100
  61#define LOOKUP_CREATE           0x0200
  62#define LOOKUP_EXCL             0x0400
  63#define LOOKUP_RENAME_TARGET    0x0800
  64
  65#define LOOKUP_JUMPED           0x1000
  66#define LOOKUP_ROOT             0x2000
  67#define LOOKUP_EMPTY            0x4000
  68
  69extern int user_path_at(int, const char __user *, unsigned, struct path *);
  70
  71#define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path)
  72#define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path)
  73#define user_path_dir(name, path) \
  74        user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path)
  75
  76extern int kern_path(const char *, unsigned, struct path *);
  77
  78extern int kern_path_parent(const char *, struct nameidata *);
  79extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
  80                           const char *, unsigned int, struct nameidata *);
  81
  82extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
  83                int (*open)(struct inode *, struct file *));
  84
  85extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
  86
  87extern int follow_down_one(struct path *);
  88extern int follow_down(struct path *);
  89extern int follow_up(struct path *);
  90
  91extern struct dentry *lock_rename(struct dentry *, struct dentry *);
  92extern void unlock_rename(struct dentry *, struct dentry *);
  93
  94static inline void nd_set_link(struct nameidata *nd, char *path)
  95{
  96        nd->saved_names[nd->depth] = path;
  97}
  98
  99static inline char *nd_get_link(struct nameidata *nd)
 100{
 101        return nd->saved_names[nd->depth];
 102}
 103
 104static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
 105{
 106        ((char *) name)[min(len, maxlen)] = '\0';
 107}
 108
 109#endif /* _LINUX_NAMEI_H */
 110