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.
The buffer was not valid.
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.
The kernel could not allocate memory for the temporary buffer holding the path.
The process does not have the capability
CAP_SYS_ADMIN
required to
look up cookie values.
The buffer was not large enough to hold the path of the directory entry.
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.
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