fs/udf/file.c - linux - Git at Google

 /*
  * 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 <linux/uaccess.h>
 #include <linux/kernel.h>
 #include <linux/string.h> /* memset */
 #include <linux/capability.h>
 #include <linux/errno.h>
 #include <linux/pagemap.h>
 #include <linux/uio.h>

 #include "udf_i.h"
 #include "udf_sb.h"

 static void __udf_adinicb_readpage(struct page *page)
 {
 	struct inode *inode = page->mapping->host;
 	char *kaddr;
 	struct udf_inode_info *iinfo = UDF_I(inode);

 	kaddr = kmap(page);
 	memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
 	memset(kaddr + inode->i_size, 0, PAGE_SIZE - inode->i_size);
 	flush_dcache_page(page);
 	SetPageUptodate(page);
 	kunmap(page);
 }

 static int udf_adinicb_readpage(struct file *file, struct page *page)
 {
 	BUG_ON(!PageLocked(page));
 	__udf_adinicb_readpage(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_begin(struct file *file,
 			struct address_space *mapping, loff_t pos,
 			unsigned len, unsigned flags, struct page **pagep,
 			void **fsdata)
 {
 	struct page *page;

 	if (WARN_ON_ONCE(pos >= PAGE_SIZE))
 		return -EIO;
 	page = grab_cache_page_write_begin(mapping, 0, flags);
 	if (!page)
 		return -ENOMEM;
 	*pagep = page;

 	if (!PageUptodate(page) && len != PAGE_SIZE)
 		__udf_adinicb_readpage(page);
 	return 0;
 }

 static ssize_t udf_adinicb_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 				     loff_t offset)
 {
 	/* Fallback to buffered I/O. */
 	return 0;
 }

 const struct address_space_operations udf_adinicb_aops = {
 	.readpage	= udf_adinicb_readpage,
 	.writepage	= udf_adinicb_writepage,
 	.write_begin	= udf_adinicb_write_begin,
 	.write_end	= simple_write_end,
 	.direct_IO	= udf_adinicb_direct_IO,
 };

 static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
 	ssize_t retval;
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file_inode(file);
 	struct udf_inode_info *iinfo = UDF_I(inode);
 	int err;

 	inode_lock(inode);

 	retval = generic_write_checks(iocb, from);
 	if (retval <= 0)
 		goto out;

 	down_write(&iinfo->i_data_sem);
 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
 		loff_t end = iocb->ki_pos + iov_iter_count(from);

 		if (inode->i_sb->s_blocksize <
 				(udf_file_entry_alloc_offset(inode) + end)) {
 			err = udf_expand_file_adinicb(inode);
 			if (err) {
 				inode_unlock(inode);
 				udf_debug("udf_expand_adinicb: err=%d\n", err);
 				return err;
 			}
 		} else {
 			iinfo->i_lenAlloc = max(end, inode->i_size);
 			up_write(&iinfo->i_data_sem);
 		}
 	} else
 		up_write(&iinfo->i_data_sem);

 	retval = __generic_file_write_iter(iocb, from);
 out:
 	inode_unlock(inode);

 	if (retval > 0) {
 		mark_inode_dirty(inode);
 		err = generic_write_sync(file, iocb->ki_pos - retval, retval);
 		if (err < 0)
 			retval = err;
 	}

 	return retval;
 }

 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = file_inode(filp);
 	long old_block, new_block;
 	int result = -EINVAL;

 	if (inode_permission(inode, 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 = -EPERM;
 			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:
 	return result;
 }

 static int udf_release_file(struct inode *inode, struct file *filp)
 {
 	if (filp->f_mode & FMODE_WRITE &&
 	    atomic_read(&inode->i_writecount) == 1) {
 		/*
 		 * Grab i_mutex to avoid races with writes changing i_size
 		 * while we are running.
 		 */
 		inode_lock(inode);
 		down_write(&UDF_I(inode)->i_data_sem);
 		udf_discard_prealloc(inode);
 		udf_truncate_tail_extent(inode);
 		up_write(&UDF_I(inode)->i_data_sem);
 		inode_unlock(inode);
 	}
 	return 0;
 }

 const struct file_operations udf_file_operations = {
 	.read_iter		= generic_file_read_iter,
 	.unlocked_ioctl		= udf_ioctl,
 	.open			= generic_file_open,
 	.mmap			= generic_file_mmap,
 	.write_iter		= udf_file_write_iter,
 	.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 = d_inode(dentry);
 	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 = udf_setsize(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,
 };
	/*
	* 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 <linux/uaccess.h>
	#include <linux/kernel.h>
	#include <linux/string.h> /* memset */
	#include <linux/capability.h>
	#include <linux/errno.h>
	#include <linux/pagemap.h>
	#include <linux/uio.h>

	#include "udf_i.h"
	#include "udf_sb.h"

	static void __udf_adinicb_readpage(struct page *page)
	{
	struct inode *inode = page->mapping->host;
	char *kaddr;
	struct udf_inode_info *iinfo = UDF_I(inode);

	kaddr = kmap(page);
	memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
	memset(kaddr + inode->i_size, 0, PAGE_SIZE - inode->i_size);
	flush_dcache_page(page);
	SetPageUptodate(page);
	kunmap(page);
	}

	static int udf_adinicb_readpage(struct file file, struct page page)
	{
	BUG_ON(!PageLocked(page));
	__udf_adinicb_readpage(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_begin(struct file *file,
	struct address_space *mapping, loff_t pos,
	unsigned len, unsigned flags, struct page **pagep,
	void **fsdata)
	{
	struct page *page;

	if (WARN_ON_ONCE(pos >= PAGE_SIZE))
	return -EIO;
	page = grab_cache_page_write_begin(mapping, 0, flags);
	if (!page)
	return -ENOMEM;
	*pagep = page;

	if (!PageUptodate(page) && len != PAGE_SIZE)
	__udf_adinicb_readpage(page);
	return 0;
	}

	static ssize_t udf_adinicb_direct_IO(struct kiocb iocb, struct iov_iter iter,
	loff_t offset)
	{
	/* Fallback to buffered I/O. */
	return 0;
	}

	const struct address_space_operations udf_adinicb_aops = {
	.readpage = udf_adinicb_readpage,
	.writepage = udf_adinicb_writepage,
	.write_begin = udf_adinicb_write_begin,
	.write_end = simple_write_end,
	.direct_IO = udf_adinicb_direct_IO,
	};

	static ssize_t udf_file_write_iter(struct kiocb iocb, struct iov_iter from)
	{
	ssize_t retval;
	struct file *file = iocb->ki_filp;
	struct inode *inode = file_inode(file);
	struct udf_inode_info *iinfo = UDF_I(inode);
	int err;

	inode_lock(inode);

	retval = generic_write_checks(iocb, from);
	if (retval <= 0)
	goto out;

	down_write(&iinfo->i_data_sem);
	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
	loff_t end = iocb->ki_pos + iov_iter_count(from);

	if (inode->i_sb->s_blocksize <
	(udf_file_entry_alloc_offset(inode) + end)) {
	err = udf_expand_file_adinicb(inode);
	if (err) {
	inode_unlock(inode);
	udf_debug("udf_expand_adinicb: err=%d\n", err);
	return err;
	}
	} else {
	iinfo->i_lenAlloc = max(end, inode->i_size);
	up_write(&iinfo->i_data_sem);
	}
	} else
	up_write(&iinfo->i_data_sem);

	retval = __generic_file_write_iter(iocb, from);
	out:
	inode_unlock(inode);

	if (retval > 0) {
	mark_inode_dirty(inode);
	err = generic_write_sync(file, iocb->ki_pos - retval, retval);
	if (err < 0)
	retval = err;
	}

	return retval;
	}

	long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
	{
	struct inode *inode = file_inode(filp);
	long old_block, new_block;
	int result = -EINVAL;

	if (inode_permission(inode, 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 = -EPERM;
	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:
	return result;
	}

	static int udf_release_file(struct inode inode, struct file filp)
	{
	if (filp->f_mode & FMODE_WRITE &&
	atomic_read(&inode->i_writecount) == 1) {
	/*
	* Grab i_mutex to avoid races with writes changing i_size
	* while we are running.
	*/
	inode_lock(inode);
	down_write(&UDF_I(inode)->i_data_sem);
	udf_discard_prealloc(inode);
	udf_truncate_tail_extent(inode);
	up_write(&UDF_I(inode)->i_data_sem);
	inode_unlock(inode);
	}
	return 0;
	}

	const struct file_operations udf_file_operations = {
	.read_iter = generic_file_read_iter,
	.unlocked_ioctl = udf_ioctl,
	.open = generic_file_open,
	.mmap = generic_file_mmap,
	.write_iter = udf_file_write_iter,
	.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 = d_inode(dentry);
	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 = udf_setsize(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,
	};