include/linux/namei.h

   1 #ifndef _LINUX_NAMEI_H
   2 #define _LINUX_NAMEI_H
   3
   4 #include <linux/linkage.h>
   5
   6 struct vfsmount;
   7
   8 struct open_intent {
   9         int     flags;
  10         int     create_mode;
  11         struct file *file;
  12 };
  13
  14 enum { MAX_NESTED_LINKS = 8 };
  15
  16 struct 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  */
  34 enum {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
  58 extern int FASTCALL(__user_walk(const char __user *, unsigned, struct nameidata *));
  59 extern 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)
  64 extern int FASTCALL(path_lookup(const char *, unsigned, struct nameidata *));
  65 extern int FASTCALL(path_walk(const char *, struct nameidata *));
  66 extern int FASTCALL(link_path_walk(const char *, struct nameidata *));
  67 extern void path_release(struct nameidata *);
  68 extern void path_release_on_umount(struct nameidata *);
  69
  70 extern int __user_path_lookup_open(const char __user *, unsigned lookup_flags, struct nameidata *nd, int open_flags);
  71 extern int path_lookup_open(int dfd, const char *name, unsigned lookup_flags, struct nameidata *, int open_flags);
  72 extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
  73                 int (*open)(struct inode *, struct file *));
  74 extern struct file *nameidata_to_filp(struct nameidata *nd, int flags);
  75 extern void release_open_intent(struct nameidata *);
  76
  77 extern struct dentry * lookup_one_len(const char *, struct dentry *, int);
  78
  79 extern int follow_down(struct vfsmount **, struct dentry **);
  80 extern int follow_up(struct vfsmount **, struct dentry **);
  81
  82 extern struct dentry *lock_rename(struct dentry *, struct dentry *);
  83 extern void unlock_rename(struct dentry *, struct dentry *);
  84
  85 static inline void nd_set_link(struct nameidata *nd, char *path)
  86 {
  87         nd->saved_names[nd->depth] = path;
  88 }
  89
  90 static inline char *nd_get_link(struct nameidata *nd)
  91 {
  92         return nd->saved_names[nd->depth];
  93 }
  94
  95 #endif /* _LINUX_NAMEI_H */