text: /*
   * 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/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;
  }
  
  long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  {
  	struct inode *inode = filp->f_dentry->d_inode;
  	long old_block, new_block;
  	int result = -EINVAL;
  
  	lock_kernel();
  
  	if (file_permission(filp, MAY_READ) != 0) {
  		udf_debug("no permission to access inode %lu\n", inode->i_ino);
  		result = -EPERM;
  		goto out;
  	}
  
  	if (!arg) {
  		udf_debug("invalid argument to udf_ioctl\n");
  		result = -EINVAL;
  		goto out;
  	}
  
  	switch (cmd) {
  	case UDF_GETVOLIDENT:
  		if (copy_to_user((char __user *)arg,
  				 UDF_SB(inode->i_sb)->s_volume_ident, 32))
  			result = -EFAULT;
  		else
  			result = 0;
  		goto out;
  	case UDF_RELOCATE_BLOCKS:
  		if (!capable(CAP_SYS_ADMIN)) {
  			result = -EACCES;
  			goto out;
  		}
  		if (get_user(old_block, (long __user *)arg)) {
  			result = -EFAULT;
  			goto out;
  		}
  		result = udf_relocate_blocks(inode->i_sb,
  						old_block, &new_block);
  		if (result == 0)
  			result = put_user(new_block, (long __user *)arg);
  		goto out;
  	case UDF_GETEASIZE:
  		result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
  		goto out;
  	case UDF_GETEABLOCK:
  		result = copy_to_user((char __user *)arg,
  				      UDF_I(inode)->i_ext.i_data,
  				      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
  		goto out;
  	}
  
  out:
  	unlock_kernel();
  	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,
  	.unlocked_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			= generic_file_fsync,
  	.splice_read		= generic_file_splice_read,
  	.llseek			= generic_file_llseek,
  };
  
  static int udf_setattr(struct dentry *dentry, struct iattr *attr)
  {
  	struct inode *inode = dentry->d_inode;
  	int error;
  
  	error = inode_change_ok(inode, attr);
  	if (error)
  		return error;
  
  	if ((attr->ia_valid & ATTR_SIZE) &&
  	    attr->ia_size != i_size_read(inode)) {
  		error = vmtruncate(inode, attr->ia_size);
  		if (error)
  			return error;
  	}
  
  	setattr_copy(inode, attr);
  	mark_inode_dirty(inode);
  	return 0;
  }
  
  const struct inode_operations udf_file_inode_operations = {
  	.setattr		= udf_setattr,
  	.truncate		= udf_truncate,
  };
  