Line data    Source code

       1             : /* file-mmu.c: ramfs MMU-based file operations
       2             :  *
       3             :  * Resizable simple ram filesystem for Linux.
       4             :  *
       5             :  * Copyright (C) 2000 Linus Torvalds.
       6             :  *               2000 Transmeta Corp.
       7             :  *
       8             :  * Usage limits added by David Gibson, Linuxcare Australia.
       9             :  * This file is released under the GPL.
      10             :  */
      11             : 
      12             : /*
      13             :  * NOTE! This filesystem is probably most useful
      14             :  * not as a real filesystem, but as an example of
      15             :  * how virtual filesystems can be written.
      16             :  *
      17             :  * It doesn't get much simpler than this. Consider
      18             :  * that this file implements the full semantics of
      19             :  * a POSIX-compliant read-write filesystem.
      20             :  *
      21             :  * Note in particular how the filesystem does not
      22             :  * need to implement any data structures of its own
      23             :  * to keep track of the virtual data: using the VFS
      24             :  * caches is sufficient.
      25             :  */
      26             : 
      27             : #include <linux/fs.h>
      28             : #include <linux/mm.h>
      29             : #include <linux/ramfs.h>
      30             : #include <linux/sched.h>
      31             : 
      32             : #include "internal.h"
      33             : 
      34           0 : static unsigned long ramfs_mmu_get_unmapped_area(struct file *file,
      35             :                 unsigned long addr, unsigned long len, unsigned long pgoff,
      36             :                 unsigned long flags)
      37             : {
      38           0 :         return current->mm->get_unmapped_area(file, addr, len, pgoff, flags);
      39             : }
      40             : 
      41             : const struct file_operations ramfs_file_operations = {
      42             :         .read_iter      = generic_file_read_iter,
      43             :         .write_iter     = generic_file_write_iter,
      44             :         .mmap           = generic_file_mmap,
      45             :         .fsync          = noop_fsync,
      46             :         .splice_read    = filemap_splice_read,
      47             :         .splice_write   = iter_file_splice_write,
      48             :         .llseek         = generic_file_llseek,
      49             :         .get_unmapped_area      = ramfs_mmu_get_unmapped_area,
      50             : };
      51             : 
      52             : const struct inode_operations ramfs_file_inode_operations = {
      53             :         .setattr        = simple_setattr,
      54             :         .getattr        = simple_getattr,
      55             : };