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/*
* linux/fs/ext2/file.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* from
*
* linux/fs/minix/file.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* ext2 fs regular file handling primitives
*
* 64-bit file support on 64-bit platforms by Jakub Jelinek
* (jj@sunsite.ms.mff.cuni.cz)
*/
#include <linux/fs.h>
#include <linux/ext2_fs.h>
#include <linux/sched.h>
static loff_t ext2_file_lseek(struct file *, loff_t, int);
static int ext2_open_file (struct inode *, struct file *);
#define EXT2_MAX_SIZE(bits) \
(((EXT2_NDIR_BLOCKS + (1LL << (bits - 2)) + \
(1LL << (bits - 2)) * (1LL << (bits - 2)) + \
(1LL << (bits - 2)) * (1LL << (bits - 2)) * (1LL << (bits - 2))) * \
(1LL << bits)) - 1)
static long long ext2_max_sizes[] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
EXT2_MAX_SIZE(10), EXT2_MAX_SIZE(11), EXT2_MAX_SIZE(12), EXT2_MAX_SIZE(13)
};
/*
* Make sure the offset never goes beyond the 32-bit mark..
*/
static loff_t ext2_file_lseek(
struct file *file,
loff_t offset,
int origin)
{
struct inode *inode = file->f_dentry->d_inode;
switch (origin) {
case 2:
offset += inode->i_size;
break;
case 1:
offset += file->f_pos;
}
if (offset<0)
return -EINVAL;
if (((unsigned long long) offset >> 32) != 0) {
if (offset > ext2_max_sizes[EXT2_BLOCK_SIZE_BITS(inode->i_sb)])
return -EINVAL;
}
if (offset != file->f_pos) {
file->f_pos = offset;
file->f_reada = 0;
file->f_version = ++event;
}
return offset;
}
/*
* Called when an inode is released. Note that this is different
* from ext2_file_open: open gets called at every open, but release
* gets called only when /all/ the files are closed.
*/
static int ext2_release_file (struct inode * inode, struct file * filp)
{
if (filp->f_mode & FMODE_WRITE)
ext2_discard_prealloc (inode);
return 0;
}
/*
* Called when an inode is about to be open.
* We use this to disallow opening RW large files on 32bit systems if
* the caller didn't specify O_LARGEFILE. On 64bit systems we force
* on this flag in sys_open.
*/
static int ext2_open_file (struct inode * inode, struct file * filp)
{
if (!(filp->f_flags & O_LARGEFILE) &&
inode->i_size > 0x7FFFFFFFLL)
return -EFBIG;
return 0;
}
/*
* We have mostly NULL's here: the current defaults are ok for
* the ext2 filesystem.
*/
struct file_operations ext2_file_operations = {
llseek: ext2_file_lseek,
read: generic_file_read,
write: generic_file_write,
ioctl: ext2_ioctl,
mmap: generic_file_mmap,
open: ext2_open_file,
release: ext2_release_file,
fsync: ext2_sync_file,
};
struct inode_operations ext2_file_inode_operations = {
truncate: ext2_truncate,
};
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