LOOKUP_DCOOKIE(2) |
Linux Programmer's Manual |
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 directory 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 3.53 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/.