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 inode    *inode; /* path.dentry.d_inode */
  23         unsigned int    flags;
  24         unsigned        seq;
  25         int             last_type;
  26         unsigned        depth;
  27         char *saved_names[MAX_NESTED_LINKS + 1];
  28
  29         /* Intent data */
  30         union {
  31                 struct open_intent open;
  32         } intent;
  33 };
  34
  35 /*
  36  * Type of the last component on LOOKUP_PARENT
  37  */
  38 enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
  39
  40 /*
  41  * The bitmask for a lookup event:
  42  *  - follow links at the end
  43  *  - require a directory
  44  *  - ending slashes ok even for nonexistent files
  45  *  - internal "there are more path components" flag
  46  *  - dentry cache is untrusted; force a real lookup
  47  *  - suppress terminal automount
  48  */
  49 #define LOOKUP_FOLLOW           0x0001
  50 #define LOOKUP_DIRECTORY        0x0002
  51 #define LOOKUP_AUTOMOUNT        0x0004
  52
  53 #define LOOKUP_PARENT           0x0010
  54 #define LOOKUP_REVAL            0x0020
  55 #define LOOKUP_RCU              0x0040
  56
  57 /*
  58  * Intent data
  59  */
  60 #define LOOKUP_OPEN             0x0100
  61 #define LOOKUP_CREATE           0x0200
  62 #define LOOKUP_EXCL             0x0400
  63 #define LOOKUP_RENAME_TARGET    0x0800
  64
  65 #define LOOKUP_JUMPED           0x1000
  66 #define LOOKUP_ROOT             0x2000
  67 #define LOOKUP_EMPTY            0x4000
  68
  69 extern int user_path_at(int, const char __user *, unsigned, struct path *);
  70 extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
  71
  72 #define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path)
  73 #define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path)
  74 #define user_path_dir(name, path) \
  75         user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path)
  76
  77 extern int kern_path(const char *, unsigned, struct path *);
  78
  79 extern struct dentry *kern_path_create(int, const char *, struct path *, int);
  80 extern struct dentry *user_path_create(int, const char __user *, struct path *, int);
  81 extern int kern_path_parent(const char *, struct nameidata *);
  82 extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
  83                            const char *, unsigned int, struct path *);
  84
  85 extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
  86                 int (*open)(struct inode *, struct file *));
  87
  88 extern struct dentry *lookup_hash(struct nameidata *nd);
  89 extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
  90
  91 extern int follow_down_one(struct path *);
  92 extern int follow_down(struct path *);
  93 extern int follow_up(struct path *);
  94
  95 extern struct dentry *lock_rename(struct dentry *, struct dentry *);
  96 extern void unlock_rename(struct dentry *, struct dentry *);
  97
  98 static inline void nd_set_link(struct nameidata *nd, char *path)
  99 {
 100         nd->saved_names[nd->depth] = path;
 101 }
 102
 103 static inline char *nd_get_link(struct nameidata *nd)
 104 {
 105         return nd->saved_names[nd->depth];
 106 }
 107
 108 static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
 109 {
 110         ((char *) name)[min(len, maxlen)] = '\0';
 111 }
 112
 113 #endif /* _LINUX_NAMEI_H */