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         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  */
  39 enum {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
  66 extern 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
  73 extern int kern_path(const char *, unsigned, struct path *);
  74
  75 extern int path_lookup(const char *, unsigned, struct nameidata *);
  76 extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
  77                            const char *, unsigned int, struct nameidata *);
  78
  79 extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
  80                 int (*open)(struct inode *, struct file *));
  81
  82 extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
  83
  84 extern int follow_down_one(struct path *);
  85 extern int follow_down(struct path *, bool);
  86 extern int follow_up(struct path *);
  87
  88 extern struct dentry *lock_rename(struct dentry *, struct dentry *);
  89 extern void unlock_rename(struct dentry *, struct dentry *);
  90
  91 static inline void nd_set_link(struct nameidata *nd, char *path)
  92 {
  93         nd->saved_names[nd->depth] = path;
  94 }
  95
  96 static inline char *nd_get_link(struct nameidata *nd)
  97 {
  98         return nd->saved_names[nd->depth];
  99 }
 100
 101 static 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 */