[mirror_ubuntu-zesty-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/buffer_head.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_CACHE_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_CACHE_SIZE))
		return -EIO;
	page = grab_cache_page_write_begin(mapping, 0, flags);
	if (!page)
		return -ENOMEM;
	*pagep = page;

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

static ssize_t udf_adinicb_direct_IO(int rw, 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);
	int err, pos;
	size_t count = iov_iter_count(from);
	struct udf_inode_info *iinfo = UDF_I(inode);

	mutex_lock(&inode->i_mutex);
	down_write(&iinfo->i_data_sem);
	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
		if (file->f_flags & O_APPEND)
			pos = inode->i_size;
		else
			pos = iocb->ki_pos;

		if (inode->i_sb->s_blocksize <
				(udf_file_entry_alloc_offset(inode) +
						pos + count)) {
			err = udf_expand_file_adinicb(inode);
			if (err) {
				mutex_unlock(&inode->i_mutex);
				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;
			up_write(&iinfo->i_data_sem);
		}
	} else
		up_write(&iinfo->i_data_sem);

	retval = __generic_file_write_iter(iocb, from);
	mutex_unlock(&inode->i_mutex);

	if (retval > 0) {
		ssize_t err;

		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.
		 */
		mutex_lock(&inode->i_mutex);
		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);
		mutex_unlock(&inode->i_mutex);
	}
	return 0;
}

const struct file_operations udf_file_operations = {
	.read			= new_sync_read,
	.read_iter		= generic_file_read_iter,
	.unlocked_ioctl		= udf_ioctl,
	.open			= generic_file_open,
	.mmap			= generic_file_mmap,
	.write			= new_sync_write,
	.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 = 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 = 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 LT	35	#include <linux/pagemap.h>
1da177e4 LT	36	#include <linux/buffer_head.h>
e2e40f2c	37	#include <linux/uio.h>
1da177e4 LT	38
	39	#include "udf_i.h"
	40	#include "udf_sb.h"
	41
9c2fc0de	42	static void __udf_adinicb_readpage(struct page *page)
1da177e4 LT	43	{
	44	struct inode *inode = page->mapping->host;
	45	char *kaddr;
48d6d8ff	46	struct udf_inode_info *iinfo = UDF_I(inode);
1da177e4	47
1da177e4	48	kaddr = kmap(page);
48d6d8ff	49	memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
9c2fc0de	50	memset(kaddr + inode->i_size, 0, PAGE_CACHE_SIZE - inode->i_size);
1da177e4 LT	51	flush_dcache_page(page);
	52	SetPageUptodate(page);
	53	kunmap(page);
9c2fc0de JK	54	}
	55
	56	static int udf_adinicb_readpage(struct file file, struct page page)
	57	{
	58	BUG_ON(!PageLocked(page));
	59	__udf_adinicb_readpage(page);
1da177e4	60	unlock_page(page);
28de7948	61
1da177e4 LT	62	return 0;
	63	}
	64
4b11111a MS	65	static int udf_adinicb_writepage(struct page *page,
4b11111a MS	66	struct writeback_control *wbc)
1da177e4 LT	67	{
	68	struct inode *inode = page->mapping->host;
	69	char *kaddr;
48d6d8ff	70	struct udf_inode_info *iinfo = UDF_I(inode);
1da177e4	71
cd7619d6	72	BUG_ON(!PageLocked(page));
1da177e4 LT	73
1da177e4 LT	74	kaddr = kmap(page);
48d6d8ff	75	memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
1da177e4 LT	76	mark_inode_dirty(inode);
	77	SetPageUptodate(page);
	78	kunmap(page);
	79	unlock_page(page);
28de7948	80
1da177e4 LT	81	return 0;
	82	}
	83
9c2fc0de JK	84	static int udf_adinicb_write_begin(struct file *file,
	85	struct address_space *mapping, loff_t pos,
	86	unsigned len, unsigned flags, struct page **pagep,
	87	void **fsdata)
	88	{
	89	struct page *page;
	90
	91	if (WARN_ON_ONCE(pos >= PAGE_CACHE_SIZE))
	92	return -EIO;
	93	page = grab_cache_page_write_begin(mapping, 0, flags);
	94	if (!page)
	95	return -ENOMEM;
	96	*pagep = page;
	97
	98	if (!PageUptodate(page) && len != PAGE_CACHE_SIZE)
	99	__udf_adinicb_readpage(page);
	100	return 0;
	101	}
	102
5eec54fc	103	static ssize_t udf_adinicb_direct_IO(int rw, struct kiocb *iocb,
d8d3d94b AV	104	struct iov_iter *iter,
d8d3d94b AV	105	loff_t offset)
5eec54fc IA	106	{
	107	/* Fallback to buffered I/O. */
	108	return 0;
	109	}
	110
f5e54d6e	111	const struct address_space_operations udf_adinicb_aops = {
28de7948 CG	112	.readpage = udf_adinicb_readpage,
28de7948 CG	113	.writepage = udf_adinicb_writepage,
9c2fc0de	114	.write_begin = udf_adinicb_write_begin,
3f1be4f9	115	.write_end = simple_write_end,
5eec54fc	116	.direct_IO = udf_adinicb_direct_IO,
1da177e4 LT	117	};
1da177e4 LT	118
d4637bc1	119	static ssize_t udf_file_write_iter(struct kiocb iocb, struct iov_iter from)
1da177e4 LT	120	{
1da177e4 LT	121	ssize_t retval;
543ade1f	122	struct file *file = iocb->ki_filp;
496ad9aa	123	struct inode *inode = file_inode(file);
1da177e4	124	int err, pos;
66ee59af	125	size_t count = iov_iter_count(from);
48d6d8ff	126	struct udf_inode_info *iinfo = UDF_I(inode);
1da177e4	127
09ebb17a	128	mutex_lock(&inode->i_mutex);
8754a3f7	129	down_write(&iinfo->i_data_sem);
48d6d8ff	130	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
1da177e4 LT	131	if (file->f_flags & O_APPEND)
	132	pos = inode->i_size;
	133	else
d4637bc1	134	pos = iocb->ki_pos;
1da177e4	135
4b11111a MS	136	if (inode->i_sb->s_blocksize <
4b11111a MS	137	(udf_file_entry_alloc_offset(inode) +
28de7948	138	pos + count)) {
7e49b6f2 JK	139	err = udf_expand_file_adinicb(inode);
7e49b6f2 JK	140	if (err) {
09ebb17a	141	mutex_unlock(&inode->i_mutex);
1da177e4 LT	142	udf_debug("udf_expand_adinicb: err=%d\n", err);
	143	return err;
	144	}
cb00ea35	145	} else {
1da177e4	146	if (pos + count > inode->i_size)
48d6d8ff	147	iinfo->i_lenAlloc = pos + count;
1da177e4	148	else
48d6d8ff	149	iinfo->i_lenAlloc = inode->i_size;
d2eb8c35	150	up_write(&iinfo->i_data_sem);
1da177e4	151	}
d2eb8c35 JK	152	} else
d2eb8c35 JK	153	up_write(&iinfo->i_data_sem);
1da177e4	154
d4637bc1	155	retval = __generic_file_write_iter(iocb, from);
09ebb17a JK	156	mutex_unlock(&inode->i_mutex);
	157
	158	if (retval > 0) {
	159	ssize_t err;
	160
1da177e4	161	mark_inode_dirty(inode);
09ebb17a JK	162	err = generic_write_sync(file, iocb->ki_pos - retval, retval);
	163	if (err < 0)
	164	retval = err;
	165	}
28de7948	166
1da177e4 LT	167	return retval;
	168	}
	169
2f07a88b	170	long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1da177e4	171	{
496ad9aa	172	struct inode *inode = file_inode(filp);
28de7948	173	long old_block, new_block;
1da177e4 LT	174	int result = -EINVAL;
1da177e4 LT	175
6f286109	176	if (inode_permission(inode, MAY_READ) != 0) {
2f07a88b JK	177	udf_debug("no permission to access inode %lu\n", inode->i_ino);
	178	result = -EPERM;
	179	goto out;
1da177e4 LT	180	}
1da177e4 LT	181
cb00ea35	182	if (!arg) {
1da177e4	183	udf_debug("invalid argument to udf_ioctl\n");
2f07a88b JK	184	result = -EINVAL;
2f07a88b JK	185	goto out;
1da177e4 LT	186	}
1da177e4 LT	187
cb00ea35 CG	188	switch (cmd) {
cb00ea35 CG	189	case UDF_GETVOLIDENT:
4b11111a MS	190	if (copy_to_user((char __user *)arg,
4b11111a MS	191	UDF_SB(inode->i_sb)->s_volume_ident, 32))
2f07a88b	192	result = -EFAULT;
4b11111a	193	else
2f07a88b JK	194	result = 0;
2f07a88b JK	195	goto out;
cb00ea35	196	case UDF_RELOCATE_BLOCKS:
2f07a88b	197	if (!capable(CAP_SYS_ADMIN)) {
41735818	198	result = -EPERM;
2f07a88b JK	199	goto out;
	200	}
	201	if (get_user(old_block, (long __user *)arg)) {
	202	result = -EFAULT;
	203	goto out;
	204	}
4b11111a MS	205	result = udf_relocate_blocks(inode->i_sb,
	206	old_block, &new_block);
	207	if (result == 0)
28de7948	208	result = put_user(new_block, (long __user *)arg);
2f07a88b	209	goto out;
cb00ea35	210	case UDF_GETEASIZE:
c0b34438	211	result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
2f07a88b	212	goto out;
cb00ea35	213	case UDF_GETEABLOCK:
c0b34438 MS	214	result = copy_to_user((char __user *)arg,
	215	UDF_I(inode)->i_ext.i_data,
	216	UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
2f07a88b	217	goto out;
1da177e4 LT	218	}
1da177e4 LT	219
2f07a88b	220	out:
1da177e4 LT	221	return result;
	222	}
	223
cb00ea35	224	static int udf_release_file(struct inode inode, struct file filp)
1da177e4	225	{
6fb1ca92	226	if (filp->f_mode & FMODE_WRITE &&
b07ef352	227	atomic_read(&inode->i_writecount) == 1) {
6fb1ca92 JK	228	/*
	229	* Grab i_mutex to avoid races with writes changing i_size
	230	* while we are running.
	231	*/
	232	mutex_lock(&inode->i_mutex);
4d0fb621	233	down_write(&UDF_I(inode)->i_data_sem);
1da177e4	234	udf_discard_prealloc(inode);
2c948b3f	235	udf_truncate_tail_extent(inode);
4d0fb621	236	up_write(&UDF_I(inode)->i_data_sem);
6fb1ca92	237	mutex_unlock(&inode->i_mutex);
1da177e4 LT	238	}
	239	return 0;
	240	}
	241
4b6f5d20	242	const struct file_operations udf_file_operations = {
aad4f8bb AV	243	.read = new_sync_read,
aad4f8bb AV	244	.read_iter = generic_file_read_iter,
2f07a88b	245	.unlocked_ioctl = udf_ioctl,
36350462	246	.open = generic_file_open,
28de7948	247	.mmap = generic_file_mmap,
d4637bc1 AV	248	.write = new_sync_write,
d4637bc1 AV	249	.write_iter = udf_file_write_iter,
28de7948	250	.release = udf_release_file,
1b061d92	251	.fsync = generic_file_fsync,
28de7948	252	.splice_read = generic_file_splice_read,
5c89468c	253	.llseek = generic_file_llseek,
1da177e4 LT	254	};
1da177e4 LT	255
d39aae9e CH	256	static int udf_setattr(struct dentry dentry, struct iattr attr)
	257	{
	258	struct inode *inode = dentry->d_inode;
	259	int error;
	260
	261	error = inode_change_ok(inode, attr);
	262	if (error)
	263	return error;
1025774c CH	264
	265	if ((attr->ia_valid & ATTR_SIZE) &&
	266	attr->ia_size != i_size_read(inode)) {
7e49b6f2	267	error = udf_setsize(inode, attr->ia_size);
1025774c CH	268	if (error)
	269	return error;
	270	}
	271
	272	setattr_copy(inode, attr);
	273	mark_inode_dirty(inode);
	274	return 0;
d39aae9e CH	275	}
d39aae9e CH	276
c5ef1c42	277	const struct inode_operations udf_file_inode_operations = {
d39aae9e	278	.setattr = udf_setattr,
1da177e4	279	};