[$] The phaseout of the mmap() file operation

The file_operationsstructure in the kernel is a set of function pointers implementing, as thename would suggest, operations on files. A subsystem that manages objectswhich can be represented by a file descriptor will provide afile_operations structure providing implementations of the variousoperations that a user of the file descriptor may want to carry out. Themmap() method, in particular, is invoked when user space calls themmap()system call to map the object behind a file descriptor into its addressspace. That method, though, is currently on its way out in a multi-releaseprocess that started in 6.17.