[mirror_ubuntu-artful-kernel.git] / fs / udf / file.c

/*
 * 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);
	loff_t isize = i_size_read(inode);

	/*
	 * We have to be careful here as truncate can change i_size under us.
	 * So just sample it once and use the same value everywhere.
	 */
	kaddr = kmap_atomic(page);
	memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, isize);
	memset(kaddr + isize, 0, PAGE_SIZE - isize);
	flush_dcache_page(page);
	SetPageUptodate(page);
	kunmap_atomic(kaddr);
}

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_atomic(page);
	memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr,
		i_size_read(inode));
	SetPageUptodate(page);
	kunmap_atomic(kaddr);
	mark_inode_dirty(inode);
	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))
		__udf_adinicb_readpage(page);
	return 0;
}

static ssize_t udf_adinicb_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
	/* Fallback to buffered I/O. */
	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 = page->mapping->host;
	loff_t last_pos = pos + copied;
	if (last_pos > inode->i_size)
		i_size_write(inode, last_pos);
	set_page_dirty(page);
	unlock_page(page);
	put_page(page);
	return copied;
}

const struct address_space_operations udf_adinicb_aops = {
	.readpage	= udf_adinicb_readpage,
	.writepage	= udf_adinicb_writepage,
	.write_begin	= udf_adinicb_write_begin,
	.write_end	= udf_adinicb_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);
		retval = generic_write_sync(iocb, retval);
	}

	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;

	if (inode_permission(inode, MAY_READ) != 0) {
		udf_debug("no permission to access inode %lu\n", inode->i_ino);
		return -EPERM;
	}

	if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) ||
		     (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) {
		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;
		return 0;
	case UDF_RELOCATE_BLOCKS:
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		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:
		return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
	case UDF_GETEABLOCK:
		return copy_to_user((char __user *)arg,
				    UDF_I(inode)->i_ext.i_data,
				    UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
	default:
		return -ENOIOCTLCMD;
	}

	return 0;
}

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 = setattr_prepare(dentry, 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,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* file.c
	3	*
	4	* PURPOSE
	5	* File handling routines for the OSTA-UDF(tm) filesystem.
	6	*
1da177e4 LT	7	* COPYRIGHT
	8	* This file is distributed under the terms of the GNU General Public
	9	* License (GPL). Copies of the GPL can be obtained from:
	10	* ftp://prep.ai.mit.edu/pub/gnu/GPL
	11	* Each contributing author retains all rights to their own work.
	12	*
	13	* (C) 1998-1999 Dave Boynton
	14	* (C) 1998-2004 Ben Fennema
	15	* (C) 1999-2000 Stelias Computing Inc
	16	*
	17	* HISTORY
	18	*
	19	* 10/02/98 dgb Attempt to integrate into udf.o
	20	* 10/07/98 Switched to using generic_readpage, etc., like isofs
	21	* And it works!
	22	* 12/06/98 blf Added udf_file_read. uses generic_file_read for all cases but
	23	* ICBTAG_FLAG_AD_IN_ICB.
	24	* 04/06/99 64 bit file handling on 32 bit systems taken from ext2 file.c
	25	* 05/12/99 Preliminary file write support
	26	*/
	27
	28	#include "udfdecl.h"
	29	#include <linux/fs.h>
e973606c	30	#include <linux/uaccess.h>
1da177e4	31	#include <linux/kernel.h>
28de7948	32	#include <linux/string.h> /* memset */
16f7e0fe	33	#include <linux/capability.h>
1da177e4	34	#include <linux/errno.h>
1da177e4	35	#include <linux/pagemap.h>
e2e40f2c	36	#include <linux/uio.h>
1da177e4 LT	37
	38	#include "udf_i.h"
	39	#include "udf_sb.h"
	40
9c2fc0de	41	static void __udf_adinicb_readpage(struct page *page)
1da177e4 LT	42	{
	43	struct inode *inode = page->mapping->host;
	44	char *kaddr;
48d6d8ff	45	struct udf_inode_info *iinfo = UDF_I(inode);
9795e0e8	46	loff_t isize = i_size_read(inode);
1da177e4	47
9795e0e8 JK	48	/*
	49	* We have to be careful here as truncate can change i_size under us.
	50	* So just sample it once and use the same value everywhere.
	51	*/
5c26eac4	52	kaddr = kmap_atomic(page);
9795e0e8 JK	53	memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, isize);
9795e0e8 JK	54	memset(kaddr + isize, 0, PAGE_SIZE - isize);
1da177e4 LT	55	flush_dcache_page(page);
1da177e4 LT	56	SetPageUptodate(page);
5c26eac4	57	kunmap_atomic(kaddr);
9c2fc0de JK	58	}
	59
	60	static int udf_adinicb_readpage(struct file file, struct page page)
	61	{
	62	BUG_ON(!PageLocked(page));
	63	__udf_adinicb_readpage(page);
1da177e4	64	unlock_page(page);
28de7948	65
1da177e4 LT	66	return 0;
	67	}
	68
4b11111a MS	69	static int udf_adinicb_writepage(struct page *page,
4b11111a MS	70	struct writeback_control *wbc)
1da177e4 LT	71	{
	72	struct inode *inode = page->mapping->host;
	73	char *kaddr;
48d6d8ff	74	struct udf_inode_info *iinfo = UDF_I(inode);
1da177e4	75
cd7619d6	76	BUG_ON(!PageLocked(page));
1da177e4	77
5c26eac4	78	kaddr = kmap_atomic(page);
146c4ad6 JK	79	memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr,
146c4ad6 JK	80	i_size_read(inode));
1da177e4	81	SetPageUptodate(page);
5c26eac4 FF	82	kunmap_atomic(kaddr);
5c26eac4 FF	83	mark_inode_dirty(inode);
1da177e4	84	unlock_page(page);
28de7948	85
1da177e4 LT	86	return 0;
	87	}
	88
9c2fc0de JK	89	static int udf_adinicb_write_begin(struct file *file,
	90	struct address_space *mapping, loff_t pos,
	91	unsigned len, unsigned flags, struct page **pagep,
	92	void **fsdata)
	93	{
	94	struct page *page;
	95
09cbfeaf	96	if (WARN_ON_ONCE(pos >= PAGE_SIZE))
9c2fc0de JK	97	return -EIO;
	98	page = grab_cache_page_write_begin(mapping, 0, flags);
	99	if (!page)
	100	return -ENOMEM;
	101	*pagep = page;
	102
f27792f5	103	if (!PageUptodate(page))
9c2fc0de JK	104	__udf_adinicb_readpage(page);
	105	return 0;
	106	}
	107
c8b8e32d	108	static ssize_t udf_adinicb_direct_IO(struct kiocb iocb, struct iov_iter iter)
5eec54fc IA	109	{
	110	/* Fallback to buffered I/O. */
	111	return 0;
	112	}
	113
5d3ddd84 AV	114	static int udf_adinicb_write_end(struct file file, struct address_space mapping,
	115	loff_t pos, unsigned len, unsigned copied,
	116	struct page page, void fsdata)
	117	{
	118	struct inode *inode = page->mapping->host;
	119	loff_t last_pos = pos + copied;
	120	if (last_pos > inode->i_size)
	121	i_size_write(inode, last_pos);
	122	set_page_dirty(page);
	123	unlock_page(page);
	124	put_page(page);
	125	return copied;
	126	}
	127
f5e54d6e	128	const struct address_space_operations udf_adinicb_aops = {
28de7948 CG	129	.readpage = udf_adinicb_readpage,
28de7948 CG	130	.writepage = udf_adinicb_writepage,
9c2fc0de	131	.write_begin = udf_adinicb_write_begin,
5d3ddd84	132	.write_end = udf_adinicb_write_end,
5eec54fc	133	.direct_IO = udf_adinicb_direct_IO,
1da177e4 LT	134	};
1da177e4 LT	135
d4637bc1	136	static ssize_t udf_file_write_iter(struct kiocb iocb, struct iov_iter from)
1da177e4 LT	137	{
1da177e4 LT	138	ssize_t retval;
543ade1f	139	struct file *file = iocb->ki_filp;
496ad9aa	140	struct inode *inode = file_inode(file);
48d6d8ff	141	struct udf_inode_info *iinfo = UDF_I(inode);
165f1a6e	142	int err;
1da177e4	143
5955102c	144	inode_lock(inode);
165f1a6e	145
3309dd04 AV	146	retval = generic_write_checks(iocb, from);
3309dd04 AV	147	if (retval <= 0)
165f1a6e AV	148	goto out;
165f1a6e AV	149
8754a3f7	150	down_write(&iinfo->i_data_sem);
48d6d8ff	151	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
165f1a6e	152	loff_t end = iocb->ki_pos + iov_iter_count(from);
1da177e4	153
4b11111a	154	if (inode->i_sb->s_blocksize <
165f1a6e	155	(udf_file_entry_alloc_offset(inode) + end)) {
7e49b6f2 JK	156	err = udf_expand_file_adinicb(inode);
7e49b6f2 JK	157	if (err) {
5955102c	158	inode_unlock(inode);
1da177e4 LT	159	udf_debug("udf_expand_adinicb: err=%d\n", err);
	160	return err;
	161	}
cb00ea35	162	} else {
165f1a6e	163	iinfo->i_lenAlloc = max(end, inode->i_size);
d2eb8c35	164	up_write(&iinfo->i_data_sem);
1da177e4	165	}
d2eb8c35 JK	166	} else
d2eb8c35 JK	167	up_write(&iinfo->i_data_sem);
1da177e4	168
d4637bc1	169	retval = __generic_file_write_iter(iocb, from);
5f380c7f	170	out:
5955102c	171	inode_unlock(inode);
09ebb17a JK	172
09ebb17a JK	173	if (retval > 0) {
1da177e4	174	mark_inode_dirty(inode);
e2592217	175	retval = generic_write_sync(iocb, retval);
09ebb17a	176	}
28de7948	177
1da177e4 LT	178	return retval;
	179	}
	180
2f07a88b	181	long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1da177e4	182	{
496ad9aa	183	struct inode *inode = file_inode(filp);
28de7948	184	long old_block, new_block;
a074faad	185	int result;
1da177e4	186
6f286109	187	if (inode_permission(inode, MAY_READ) != 0) {
2f07a88b	188	udf_debug("no permission to access inode %lu\n", inode->i_ino);
a074faad	189	return -EPERM;
1da177e4 LT	190	}
1da177e4 LT	191
782deb2e FF	192	if (!arg && ((cmd == UDF_GETVOLIDENT) \|\| (cmd == UDF_GETEASIZE) \|\|
782deb2e FF	193	(cmd == UDF_RELOCATE_BLOCKS) \|\| (cmd == UDF_GETEABLOCK))) {
1da177e4	194	udf_debug("invalid argument to udf_ioctl\n");
a074faad	195	return -EINVAL;
1da177e4 LT	196	}
1da177e4 LT	197
cb00ea35 CG	198	switch (cmd) {
cb00ea35 CG	199	case UDF_GETVOLIDENT:
4b11111a MS	200	if (copy_to_user((char __user *)arg,
4b11111a MS	201	UDF_SB(inode->i_sb)->s_volume_ident, 32))
a074faad FF	202	return -EFAULT;
a074faad FF	203	return 0;
cb00ea35	204	case UDF_RELOCATE_BLOCKS:
a074faad FF	205	if (!capable(CAP_SYS_ADMIN))
	206	return -EPERM;
	207	if (get_user(old_block, (long __user *)arg))
	208	return -EFAULT;
4b11111a MS	209	result = udf_relocate_blocks(inode->i_sb,
	210	old_block, &new_block);
	211	if (result == 0)
28de7948	212	result = put_user(new_block, (long __user *)arg);
a074faad	213	return result;
cb00ea35	214	case UDF_GETEASIZE:
a074faad	215	return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
cb00ea35	216	case UDF_GETEABLOCK:
a074faad FF	217	return copy_to_user((char __user *)arg,
	218	UDF_I(inode)->i_ext.i_data,
	219	UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
782deb2e FF	220	default:
782deb2e FF	221	return -ENOIOCTLCMD;
1da177e4 LT	222	}
1da177e4 LT	223
a074faad	224	return 0;
1da177e4 LT	225	}
1da177e4 LT	226
cb00ea35	227	static int udf_release_file(struct inode inode, struct file filp)
1da177e4	228	{
6fb1ca92	229	if (filp->f_mode & FMODE_WRITE &&
b07ef352	230	atomic_read(&inode->i_writecount) == 1) {
6fb1ca92 JK	231	/*
	232	* Grab i_mutex to avoid races with writes changing i_size
	233	* while we are running.
	234	*/
5955102c	235	inode_lock(inode);
4d0fb621	236	down_write(&UDF_I(inode)->i_data_sem);
1da177e4	237	udf_discard_prealloc(inode);
2c948b3f	238	udf_truncate_tail_extent(inode);
4d0fb621	239	up_write(&UDF_I(inode)->i_data_sem);
5955102c	240	inode_unlock(inode);
1da177e4 LT	241	}
	242	return 0;
	243	}
	244
4b6f5d20	245	const struct file_operations udf_file_operations = {
aad4f8bb	246	.read_iter = generic_file_read_iter,
2f07a88b	247	.unlocked_ioctl = udf_ioctl,
36350462	248	.open = generic_file_open,
28de7948	249	.mmap = generic_file_mmap,
d4637bc1	250	.write_iter = udf_file_write_iter,
28de7948	251	.release = udf_release_file,
1b061d92	252	.fsync = generic_file_fsync,
28de7948	253	.splice_read = generic_file_splice_read,
5c89468c	254	.llseek = generic_file_llseek,
1da177e4 LT	255	};
1da177e4 LT	256
d39aae9e CH	257	static int udf_setattr(struct dentry dentry, struct iattr attr)
d39aae9e CH	258	{
2b0143b5	259	struct inode *inode = d_inode(dentry);
d39aae9e CH	260	int error;
d39aae9e CH	261
31051c85	262	error = setattr_prepare(dentry, attr);
d39aae9e CH	263	if (error)
d39aae9e CH	264	return error;
1025774c CH	265
	266	if ((attr->ia_valid & ATTR_SIZE) &&
	267	attr->ia_size != i_size_read(inode)) {
7e49b6f2	268	error = udf_setsize(inode, attr->ia_size);
1025774c CH	269	if (error)
	270	return error;
	271	}
	272
	273	setattr_copy(inode, attr);
	274	mark_inode_dirty(inode);
	275	return 0;
d39aae9e CH	276	}
d39aae9e CH	277
c5ef1c42	278	const struct inode_operations udf_file_inode_operations = {
d39aae9e	279	.setattr = udf_setattr,
1da177e4	280	};