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/*
* linux/fs/fat/file.c
*
* Written 1992,1993 by Werner Almesberger
*
* regular file handling primitives for fat-based filesystems
*/
#include <linux/sched.h>
#include <linux/locks.h>
#include <linux/fs.h>
#include <linux/msdos_fs.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/pagemap.h>
#include <linux/fat_cvf.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#define PRINTK(x)
#define Printk(x) printk x
struct file_operations fat_file_operations = {
llseek: generic_file_llseek,
read: fat_file_read,
write: fat_file_write,
mmap: generic_file_mmap,
fsync: file_fsync,
};
struct inode_operations fat_file_inode_operations = {
truncate: fat_truncate,
setattr: fat_notify_change,
};
ssize_t fat_file_read(
struct file *filp,
char *buf,
size_t count,
loff_t *ppos)
{
struct inode *inode = filp->f_dentry->d_inode;
return MSDOS_SB(inode->i_sb)->cvf_format
->cvf_file_read(filp,buf,count,ppos);
}
int fat_get_block(struct inode *inode, long iblock, struct buffer_head *bh_result, int create)
{
struct super_block *sb = inode->i_sb;
unsigned long phys;
phys = fat_bmap(inode, iblock);
if (phys) {
bh_result->b_dev = inode->i_dev;
bh_result->b_blocknr = phys;
bh_result->b_state |= (1UL << BH_Mapped);
return 0;
}
if (!create)
return 0;
if (iblock << sb->s_blocksize_bits != MSDOS_I(inode)->mmu_private) {
BUG();
return -EIO;
}
if (!(iblock % MSDOS_SB(inode->i_sb)->cluster_size)) {
if (fat_add_cluster(inode) < 0)
return -ENOSPC;
}
MSDOS_I(inode)->mmu_private += sb->s_blocksize;
phys = fat_bmap(inode, iblock);
if (!phys)
BUG();
bh_result->b_dev = inode->i_dev;
bh_result->b_blocknr = phys;
bh_result->b_state |= (1UL << BH_Mapped);
bh_result->b_state |= (1UL << BH_New);
return 0;
}
ssize_t fat_file_write(
struct file *filp,
const char *buf,
size_t count,
loff_t *ppos)
{
struct inode *inode = filp->f_dentry->d_inode;
struct super_block *sb = inode->i_sb;
return MSDOS_SB(sb)->cvf_format
->cvf_file_write(filp,buf,count,ppos);
}
ssize_t default_fat_file_write(
struct file *filp,
const char *buf,
size_t count,
loff_t *ppos)
{
struct inode *inode = filp->f_dentry->d_inode;
int retval;
retval = generic_file_write(filp, buf, count, ppos);
if (retval > 0) {
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
mark_inode_dirty(inode);
}
return retval;
}
void fat_truncate(struct inode *inode)
{
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
int cluster;
/* Why no return value? Surely the disk could fail... */
if (IS_RDONLY (inode))
return /* -EPERM */;
if (IS_IMMUTABLE(inode))
return /* -EPERM */;
cluster = 1 << sbi->cluster_bits;
/*
* This protects against truncating a file bigger than it was then
* trying to write into the hole.
*/
if (MSDOS_I(inode)->mmu_private > inode->i_size)
MSDOS_I(inode)->mmu_private = inode->i_size;
fat_free(inode, (inode->i_size + (cluster - 1)) >> sbi->cluster_bits);
MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
inode->i_ctime = inode->i_mtime = CURRENT_TIME;
mark_inode_dirty(inode);
}
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