fs/ufs/file.c

   1 /*
   2  *  linux/fs/ufs/file.c
   3  *
   4  * Copyright (C) 1998
   5  * Daniel Pirkl <daniel.pirkl@email.cz>
   6  * Charles University, Faculty of Mathematics and Physics
   7  *
   8  *  from
   9  *
  10  *  linux/fs/ext2/file.c
  11  *
  12  * Copyright (C) 1992, 1993, 1994, 1995
  13  * Remy Card (card@masi.ibp.fr)
  14  * Laboratoire MASI - Institut Blaise Pascal
  15  * Universite Pierre et Marie Curie (Paris VI)
  16  *
  17  *  from
  18  *
  19  *  linux/fs/minix/file.c
  20  *
  21  *  Copyright (C) 1991, 1992  Linus Torvalds
  22  *
  23  *  ext2 fs regular file handling primitives
  24  */
  25
  26 #include <asm/uaccess.h>
  27 #include <asm/system.h>
  28
  29 #include <linux/errno.h>
  30 #include <linux/fs.h>
  31 #include <linux/ufs_fs.h>
  32 #include <linux/fcntl.h>
  33 #include <linux/sched.h>
  34 #include <linux/stat.h>
  35 #include <linux/locks.h>
  36 #include <linux/mm.h>
  37 #include <linux/pagemap.h>
  38
  39 /*
  40  * Make sure the offset never goes beyond the 32-bit mark..
  41  */
  42 static long long ufs_file_lseek(
  43         struct file *file,
  44         long long offset,
  45         int origin )
  46 {
  47         long long retval;
  48         struct inode *inode = file->f_dentry->d_inode;
  49
  50         switch (origin) {
  51                 case 2:
  52                         offset += inode->i_size;
  53                         break;
  54                 case 1:
  55                         offset += file->f_pos;
  56         }
  57         retval = -EINVAL;
  58         /* make sure the offset fits in 32 bits */
  59         if (((unsigned long long) offset >> 32) == 0) {
  60                 if (offset != file->f_pos) {
  61                         file->f_pos = offset;
  62                         file->f_reada = 0;
  63                         file->f_version = ++event;
  64                 }
  65                 retval = offset;
  66         }
  67         return retval;
  68 }
  69
  70 /*
  71  * We have mostly NULL's here: the current defaults are ok for
  72  * the ufs filesystem.
  73  */
  74 struct file_operations ufs_file_operations = {
  75         llseek:         ufs_file_lseek,
  76         read:           generic_file_read,
  77         write:          generic_file_write,
  78         mmap:           generic_file_mmap,
  79 };
  80
  81 struct inode_operations ufs_file_inode_operations = {
  82         truncate:       ufs_truncate,
  83 };