original development tree for Linux kernel GTP module; now long in mainline.
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/*
* file.c
*
* PURPOSE
* File handling routines for the OSTA-UDF(tm) filesystem.
*
* COPYRIGHT
* This file is distributed under the terms of the GNU General Public
* License (GPL). Copies of the GPL can be obtained from:
* ftp://prep.ai.mit.edu/pub/gnu/GPL
* Each contributing author retains all rights to their own work.
*
* (C) 1998-1999 Dave Boynton
* (C) 1998-2004 Ben Fennema
* (C) 1999-2000 Stelias Computing Inc
*
* HISTORY
*
* 10/02/98 dgb Attempt to integrate into udf.o
* 10/07/98 Switched to using generic_readpage, etc., like isofs
* And it works!
* 12/06/98 blf Added udf_file_read. uses generic_file_read for all cases but
* ICBTAG_FLAG_AD_IN_ICB.
* 04/06/99 64 bit file handling on 32 bit systems taken from ext2 file.c
* 05/12/99 Preliminary file write support
*/
#include "udfdecl.h"
#include <linux/fs.h>
#include <asm/uaccess.h>
#include <linux/kernel.h>
#include <linux/string.h> /* memset */
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/smp_lock.h>
#include <linux/pagemap.h>
#include <linux/quotaops.h>
#include <linux/buffer_head.h>
#include <linux/aio.h>
#include "udf_i.h"
#include "udf_sb.h"
static int udf_adinicb_readpage(struct file *file, struct page *page)
{
struct inode *inode = page->mapping->host;
char *kaddr;
struct udf_inode_info *iinfo = UDF_I(inode);
BUG_ON(!PageLocked(page));
kaddr = kmap(page);
memset(kaddr, 0, PAGE_CACHE_SIZE);
memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
flush_dcache_page(page);
SetPageUptodate(page);
kunmap(page);
unlock_page(page);
return 0;
}
static int udf_adinicb_writepage(struct page *page,
struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
char *kaddr;
struct udf_inode_info *iinfo = UDF_I(inode);
BUG_ON(!PageLocked(page));
kaddr = kmap(page);
memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
mark_inode_dirty(inode);
SetPageUptodate(page);
kunmap(page);
unlock_page(page);
return 0;
}
static int udf_adinicb_write_end(struct file *file,
struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
struct inode *inode = mapping->host;
unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
char *kaddr;
struct udf_inode_info *iinfo = UDF_I(inode);
kaddr = kmap_atomic(page, KM_USER0);
memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr + offset,
kaddr + offset, copied);
kunmap_atomic(kaddr, KM_USER0);
return simple_write_end(file, mapping, pos, len, copied, page, fsdata);
}
const struct address_space_operations udf_adinicb_aops = {
.readpage = udf_adinicb_readpage,
.writepage = udf_adinicb_writepage,
.sync_page = block_sync_page,
.write_begin = simple_write_begin,
.write_end = udf_adinicb_write_end,
};
static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t ppos)
{
ssize_t retval;
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_path.dentry->d_inode;
int err, pos;
size_t count = iocb->ki_left;
struct udf_inode_info *iinfo = UDF_I(inode);
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
if (file->f_flags & O_APPEND)
pos = inode->i_size;
else
pos = ppos;
if (inode->i_sb->s_blocksize <
(udf_file_entry_alloc_offset(inode) +
pos + count)) {
udf_expand_file_adinicb(inode, pos + count, &err);
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
udf_debug("udf_expand_adinicb: err=%d\n", err);
return err;
}
} else {
if (pos + count > inode->i_size)
iinfo->i_lenAlloc = pos + count;
else
iinfo->i_lenAlloc = inode->i_size;
}
}
retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
if (retval > 0)
mark_inode_dirty(inode);
return retval;
}
int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
unsigned long arg)
{
long old_block, new_block;
int result = -EINVAL;
if (file_permission(filp, MAY_READ) != 0) {
udf_debug("no permission to access inode %lu\n",
inode->i_ino);
return -EPERM;
}
if (!arg) {
udf_debug("invalid argument to udf_ioctl\n");
return -EINVAL;
}
switch (cmd) {
case UDF_GETVOLIDENT:
if (copy_to_user((char __user *)arg,
UDF_SB(inode->i_sb)->s_volume_ident, 32))
return -EFAULT;
else
return 0;
case UDF_RELOCATE_BLOCKS:
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (get_user(old_block, (long __user *)arg))
return -EFAULT;
result = udf_relocate_blocks(inode->i_sb,
old_block, &new_block);
if (result == 0)
result = put_user(new_block, (long __user *)arg);
return result;
case UDF_GETEASIZE:
result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
break;
case UDF_GETEABLOCK:
result = copy_to_user((char __user *)arg,
UDF_I(inode)->i_ext.i_data,
UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
break;
}
return result;
}
static int udf_release_file(struct inode *inode, struct file *filp)
{
if (filp->f_mode & FMODE_WRITE) {
mutex_lock(&inode->i_mutex);
lock_kernel();
udf_discard_prealloc(inode);
udf_truncate_tail_extent(inode);
unlock_kernel();
mutex_unlock(&inode->i_mutex);
}
return 0;
}
const struct file_operations udf_file_operations = {
.read = do_sync_read,
.aio_read = generic_file_aio_read,
.ioctl = udf_ioctl,
.open = generic_file_open,
.mmap = generic_file_mmap,
.write = do_sync_write,
.aio_write = udf_file_aio_write,
.release = udf_release_file,
.fsync = simple_fsync,
.splice_read = generic_file_splice_read,
.llseek = generic_file_llseek,
};
static int udf_setattr(struct dentry *dentry, struct iattr *iattr)
{
struct inode *inode = dentry->d_inode;
int error;
error = inode_change_ok(inode, iattr);
if (error)
return error;
if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
(iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
error = dquot_transfer(inode, iattr);
if (error)
return error;
}
return inode_setattr(inode, iattr);
}
const struct inode_operations udf_file_inode_operations = {
.truncate = udf_truncate,
.setattr = udf_setattr,
};