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
   8 struct vfsmount;
   9
  10 struct open_intent {
  11         int     flags;
  12         int     create_mode;
  13         struct file *file;
  14 };
  15
  16 enum { MAX_NESTED_LINKS = 8 };
  17
  18 struct nameidata {
  19         struct path     path;
  20         struct qstr     last;
  21         struct path     root;
  22         unsigned int    flags;
  23         int             last_type;
  24         unsigned        depth;
  25         char *saved_names[MAX_NESTED_LINKS + 1];
  26
  27         /* Intent data */
  28         union {
  29                 struct open_intent open;
  30         } intent;
  31 };
  32
  33 /*
  34  * Type of the last component on LOOKUP_PARENT
  35  */
  36 enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
  37
  38 /*
  39  * The bitmask for a lookup event:
  40  *  - follow links at the end
  41  *  - require a directory
  42  *  - ending slashes ok even for nonexistent files
  43  *  - internal "there are more path components" flag
  44  *  - locked when lookup done with dcache_lock held
  45  *  - dentry cache is untrusted; force a real lookup
  46  */
  47 #define LOOKUP_FOLLOW            1
  48 #define LOOKUP_DIRECTORY         2
  49 #define LOOKUP_CONTINUE          4
  50 #define LOOKUP_PARENT           16
  51 #define LOOKUP_REVAL            64
  52 /*
  53  * Intent data
  54  */
  55 #define LOOKUP_OPEN             0x0100
  56 #define LOOKUP_CREATE           0x0200
  57 #define LOOKUP_EXCL             0x0400
  58 #define LOOKUP_RENAME_TARGET    0x0800
  59
  60 extern int user_path_at(int, const char __user *, unsigned, struct path *);
  61
  62 #define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path)
  63 #define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path)
  64 #define user_path_dir(name, path) \
  65         user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path)
  66
  67 extern int kern_path(const char *, unsigned, struct path *);
  68
  69 extern int path_lookup(const char *, unsigned, struct nameidata *);
  70 extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
  71                            const char *, unsigned int, struct nameidata *);
  72
  73 extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
  74                 int (*open)(struct inode *, struct file *));
  75 extern struct file *nameidata_to_filp(struct nameidata *nd, int flags);
  76 extern void release_open_intent(struct nameidata *);
  77
  78 extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
  79 extern struct dentry *lookup_one_noperm(const char *, struct dentry *);
  80
  81 extern int follow_down(struct path *);
  82 extern int follow_up(struct path *);
  83
  84 extern struct dentry *lock_rename(struct dentry *, struct dentry *);
  85 extern void unlock_rename(struct dentry *, struct dentry *);
  86
  87 static inline void nd_set_link(struct nameidata *nd, char *path)
  88 {
  89         nd->saved_names[nd->depth] = path;
  90 }
  91
  92 static inline char *nd_get_link(struct nameidata *nd)
  93 {
  94         return nd->saved_names[nd->depth];
  95 }
  96
  97 static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
  98 {
  99         ((char *) name)[min(len, maxlen)] = '\0';
 100 }
 101
 102 #endif /* _LINUX_NAMEI_H */