lookup_dcookie(2)
NAME
lookup_dcookie - return a directory entry's path
SYNOPSIS
int lookup_dcookie(u64 cookie, char *buffer, size_t len);
DESCRIPTION
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.
RETURN VALUE
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.
ERRORS
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.
- ENAMETOOLONG
- 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 values.
- ERANGE The buffer was not large enough to hold the path of the direc
- tory entry.
VERSIONS
Available since Linux 2.5.43. The ENAMETOOLONG error return was added
in 2.5.70.
CONFORMING TO
lookup_dcookie() is Linux-specific.
NOTES
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.
COLOPHON
- This page is part of release 3.25 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.