The FCL stores changes in a sparse file, referred to as the FCL file, in the file system namespace. The FCL file is always located in /mount_point/lost+found/changelog
. The FCL file behaves like a regular file, however, some user-level operations are prohibited, such as writes. The standard system calls open(2), lseek(2), read(2) and close(2) can access the data in the FCL file. All other system calls such as mmap(2), unlink(2), and ioctl(2) are not allowed on the FCL file.