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/*
* linux/fs/fat/file.c
*
* Written 1992,1993 by Werner Almesberger
*
* regular file handling primitives for fat-based filesystems
*/
#define ASC_LINUX_VERSION(V, P, S) (((V) * 65536) + ((P) * 256) + (S))
#include <linux/version.h>
#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>
#include "msbuffer.h"
#define MIN(a,b) (((a) < (b)) ? (a) : (b))
#define MAX(a,b) (((a) > (b)) ? (a) : (b))
#define PRINTK(x)
#define Printk(x) printk x
static struct file_operations fat_file_operations = {
NULL, /* lseek - default */
fat_file_read, /* read */
fat_file_write, /* write */
NULL, /* readdir - bad */
NULL, /* select v2.0.x/poll v2.1.x - default */
NULL, /* ioctl - default */
generic_file_mmap, /* mmap */
NULL, /* no special open is needed */
NULL, /* flush */
NULL, /* release */
file_fsync /* fsync */
};
struct inode_operations fat_file_inode_operations = {
&fat_file_operations, /* default file operations */
NULL, /* create */
NULL, /* lookup */
NULL, /* link */
NULL, /* unlink */
NULL, /* symlink */
NULL, /* mkdir */
NULL, /* rmdir */
NULL, /* mknod */
NULL, /* rename */
NULL, /* readlink */
NULL, /* follow_link */
fat_get_block, /* get_block */
block_read_full_page, /* readpage */
NULL, /* writepage */
block_flushpage, /* flushpage */
fat_truncate, /* truncate */
NULL, /* permission */
NULL, /* smap */
NULL /* revalidate */
};
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) {
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<<9 != MSDOS_I(inode)->i_realsize) {
BUG();
return -EIO;
}
if (!(iblock % MSDOS_SB(inode->i_sb)->cluster_size)) {
if (fat_add_cluster(inode))
return -ENOSPC;
}
MSDOS_I(inode)->i_realsize+=SECTOR_SIZE;
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;
}
static int fat_write_partial_page(struct file *file, struct page *page, unsigned long offset, unsigned long bytes, const char * buf)
{
struct dentry *dentry = file->f_dentry;
struct inode *inode = dentry->d_inode;
struct page *new_page, **hash;
unsigned long pgpos;
struct page *page_cache = NULL;
long status;
pgpos = MSDOS_I(inode)->i_realsize >> PAGE_CACHE_SHIFT;
while (pgpos < page->index) {
hash = page_hash(&inode->i_data, pgpos);
repeat_find: new_page = __find_lock_page(&inode->i_data, pgpos, hash);
if (!new_page) {
if (!page_cache) {
page_cache = page_cache_alloc();
if (page_cache)
goto repeat_find;
status = -ENOMEM;
goto out;
}
new_page = page_cache;
if (add_to_page_cache_unique(new_page,&inode->i_data,pgpos,hash))
goto repeat_find;
page_cache = NULL;
}
status = block_write_cont_page(file, new_page, PAGE_SIZE, 0, NULL);
UnlockPage(new_page);
page_cache_release(new_page);
if (status < 0)
goto out;
pgpos = MSDOS_I(inode)->i_realsize >> PAGE_CACHE_SHIFT;
}
status = block_write_cont_page(file, page, offset, bytes, buf);
out:
if (page_cache)
page_cache_free(page_cache);
return status;
}
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,
fat_write_partial_page);
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 = SECTOR_SIZE*sbi->cluster_size;
MSDOS_I(inode)->i_realsize = ((inode->i_size-1) | (SECTOR_SIZE-1)) + 1;
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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