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