Provided by: manpages-dev_3.54-1ubuntu1_all bug


       lookup_dcookie - return a directory entry's path


       int lookup_dcookie(u64 cookie, char *buffer, size_t len);


       Look up the full path of the directory entry specified by the value cookie.  The cookie is
       an opaque identifier uniquely identifying a particular directory entry.  The buffer  given
       is filled in with the full path of the directory entry.

       For lookup_dcookie() to return successfully, the kernel must still hold a cookie reference
       to the directory entry.


       On success, lookup_dcookie() returns the length of the path string copied into the buffer.
       On error, -1 is returned, and errno is set appropriately.


       EFAULT The buffer was not valid.

       EINVAL The kernel has no registered cookie/directory entry mappings at the time of lookup,
              or the cookie does not refer to a valid directory entry.

              The name could not fit in the buffer.

       ENOMEM The kernel could not allocate memory for the temporary buffer holding the path.

       EPERM  The process does not have the capability CAP_SYS_ADMIN required to look  up  cookie

       ERANGE The buffer was not large enough to hold the path of the directory entry.


       Available since Linux 2.5.43.  The ENAMETOOLONG error return was added in 2.5.70.


       lookup_dcookie() is Linux-specific.


       lookup_dcookie()  is  a  special-purpose  system call, currently used only by the oprofile
       profiler.  It relies on a kernel driver to register cookies for directory entries.

       The path returned may be suffixed by the string " (deleted)" if the  directory  entry  has
       been removed.


       This  page  is  part of release 3.54 of the Linux man-pages project.  A description of the
       project,    and    information    about    reporting    bugs,    can    be    found     at