fs/ramfs/file-mmu.c

   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
  30 const struct address_space_operations ramfs_aops = {
  31         .readpage       = simple_readpage,
  32         .prepare_write  = simple_prepare_write,
  33         .commit_write   = simple_commit_write,
  34         .set_page_dirty = __set_page_dirty_no_writeback,
  35 };
  36
  37 const struct file_operations ramfs_file_operations = {
  38         .read           = do_sync_read,
  39         .aio_read       = generic_file_aio_read,
  40         .write          = do_sync_write,
  41         .aio_write      = generic_file_aio_write,
  42         .mmap           = generic_file_mmap,
  43         .fsync          = simple_sync_file,
  44         .splice_read    = generic_file_splice_read,
  45         .llseek         = generic_file_llseek,
  46 };
  47
  48 const struct inode_operations ramfs_file_inode_operations = {
  49         .getattr        = simple_getattr,
  50 };