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
   7 struct vfsmount;
   8
   9 struct open_intent {
  10         int     flags;
  11         int     create_mode;
  12         struct file *file;
  13 };
  14
  15 enum { MAX_NESTED_LINKS = 8 };
  16
  17 struct nameidata {
  18         struct dentry   *dentry;
  19         struct vfsmount *mnt;
  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 struct path {
  33         struct vfsmount *mnt;
  34         struct dentry *dentry;
  35 };
  36
  37 /*
  38  * Type of the last component on LOOKUP_PARENT
  39  */
  40 enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
  41
  42 /*
  43  * The bitmask for a lookup event:
  44  *  - follow links at the end
  45  *  - require a directory
  46  *  - ending slashes ok even for nonexistent files
  47  *  - internal "there are more path compnents" flag
  48  *  - locked when lookup done with dcache_lock held
  49  *  - dentry cache is untrusted; force a real lookup
  50  */
  51 #define LOOKUP_FOLLOW            1
  52 #define LOOKUP_DIRECTORY         2
  53 #define LOOKUP_CONTINUE          4
  54 #define LOOKUP_PARENT           16
  55 #define LOOKUP_NOALT            32
  56 #define LOOKUP_REVAL            64
  57 /*
  58  * Intent data
  59  */
  60 #define LOOKUP_OPEN             (0x0100)
  61 #define LOOKUP_CREATE           (0x0200)
  62 #define LOOKUP_ACCESS           (0x0400)
  63 #define LOOKUP_CHDIR            (0x0800)
  64
  65 extern int FASTCALL(__user_walk(const char __user *, unsigned, struct nameidata *));
  66 extern int FASTCALL(__user_walk_fd(int dfd, const char __user *, unsigned, struct nameidata *));
  67 #define user_path_walk(name,nd) \
  68         __user_walk_fd(AT_FDCWD, name, LOOKUP_FOLLOW, nd)
  69 #define user_path_walk_link(name,nd) \
  70         __user_walk_fd(AT_FDCWD, name, 0, nd)
  71 extern int FASTCALL(path_lookup(const char *, unsigned, struct nameidata *));
  72 extern int FASTCALL(path_walk(const char *, struct nameidata *));
  73 extern int FASTCALL(link_path_walk(const char *, struct nameidata *));
  74 extern void path_release(struct nameidata *);
  75 extern void path_release_on_umount(struct nameidata *);
  76
  77 extern int __user_path_lookup_open(const char __user *, unsigned lookup_flags, struct nameidata *nd, int open_flags);
  78 extern int path_lookup_open(int dfd, const char *name, unsigned lookup_flags, struct nameidata *, int open_flags);
  79 extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
  80                 int (*open)(struct inode *, struct file *));
  81 extern struct file *nameidata_to_filp(struct nameidata *nd, int flags);
  82 extern void release_open_intent(struct nameidata *);
  83
  84 extern struct dentry * lookup_one_len(const char *, struct dentry *, int);
  85 extern struct dentry *lookup_one_len_kern(const char *, struct dentry *, int);
  86
  87 extern int follow_down(struct vfsmount **, struct dentry **);
  88 extern int follow_up(struct vfsmount **, struct dentry **);
  89
  90 extern struct dentry *lock_rename(struct dentry *, struct dentry *);
  91 extern void unlock_rename(struct dentry *, struct dentry *);
  92
  93 static inline void nd_set_link(struct nameidata *nd, char *path)
  94 {
  95         nd->saved_names[nd->depth] = path;
  96 }
  97
  98 static inline char *nd_get_link(struct nameidata *nd)
  99 {
 100         return nd->saved_names[nd->depth];
 101 }
 102
 103 #endif /* _LINUX_NAMEI_H */