lookup_dcookie - 返回目錄條目的路徑

內容簡介

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

描述

查找的值cookie中的cookie是一個不透明的標識符，唯一地標識一個特定的目錄項中指定的目錄項的完整路徑。給出的緩衝區填入目錄項的完整路徑。

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

注意

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.

返回值

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.

錯誤

標籤

描述

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_ADMINrequired to look up cookie values.

ERANGE

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

遵循於

lookup_dcookie () is Linux-specific.

可用性

Since Linux 2.5.43. The ENAMETOOLONG error return was added in 2.5.70.