summaryrefslogtreecommitdiff
path: root/fs/udf/file.c
blob: 84e0b241940de23bfeda025cc001b16f33621ea8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
/*
 * 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"

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_data + iinfo->i_lenEAttr, isize);
	memset(kaddr + isize, 0, PAGE_SIZE - isize);
	flush_dcache_page(page);
	SetPageUptodate(page);
	kunmap_atomic(kaddr);
}

static vm_fault_t udf_page_mkwrite(struct vm_fault *vmf)
{
	struct vm_area_struct *vma = vmf->vma;
	struct inode *inode = file_inode(vma->vm_file);
	struct address_space *mapping = inode->i_mapping;
	struct page *page = vmf->page;
	loff_t size;
	unsigned int end;
	vm_fault_t ret = VM_FAULT_LOCKED;
	int err;

	sb_start_pagefault(inode->i_sb);
	file_update_time(vma->vm_file);
	filemap_invalidate_lock_shared(mapping);
	lock_page(page);
	size = i_size_read(inode);
	if (page->mapping != inode->i_mapping || page_offset(page) >= size) {
		unlock_page(page);
		ret = VM_FAULT_NOPAGE;
		goto out_unlock;
	}
	/* Space is already allocated for in-ICB file */
	if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
		goto out_dirty;
	if (page->index == size >> PAGE_SHIFT)
		end = size & ~PAGE_MASK;
	else
		end = PAGE_SIZE;
	err = __block_write_begin(page, 0, end, udf_get_block);
	if (!err)
		err = block_commit_write(page, 0, end);
	if (err < 0) {
		unlock_page(page);
		ret = block_page_mkwrite_return(err);
		goto out_unlock;
	}
out_dirty:
	set_page_dirty(page);
	wait_for_stable_page(page);
out_unlock:
	filemap_invalidate_unlock_shared(mapping);
	sb_end_pagefault(inode->i_sb);
	return ret;
}

static const struct vm_operations_struct udf_file_vm_ops = {
	.fault		= filemap_fault,
	.map_pages	= filemap_map_pages,
	.page_mkwrite	= udf_page_mkwrite,
};

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);

	inode_lock(inode);

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

	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB &&
	    inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) +
				 iocb->ki_pos + iov_iter_count(from))) {
		filemap_invalidate_lock(inode->i_mapping);
		retval = udf_expand_file_adinicb(inode);
		filemap_invalidate_unlock(inode->i_mapping);
		if (retval)
			goto out;
	}

	retval = __generic_file_write_iter(iocb, from);
out:
	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB && retval > 0) {
		down_write(&iinfo->i_data_sem);
		iinfo->i_lenAlloc = inode->i_size;
		up_write(&iinfo->i_data_sem);
	}
	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 (file_permission(filp, 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_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;
}

static int udf_file_mmap(struct file *file, struct vm_area_struct *vma)
{
	file_accessed(file);
	vma->vm_ops = &udf_file_vm_ops;

	return 0;
}

const struct file_operations udf_file_operations = {
	.read_iter		= generic_file_read_iter,
	.unlocked_ioctl		= udf_ioctl,
	.open			= generic_file_open,
	.mmap			= udf_file_mmap,
	.write_iter		= udf_file_write_iter,
	.release		= udf_release_file,
	.fsync			= generic_file_fsync,
	.splice_read		= generic_file_splice_read,
	.splice_write		= iter_file_splice_write,
	.llseek			= generic_file_llseek,
};

static int udf_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
		       struct iattr *attr)
{
	struct inode *inode = d_inode(dentry);
	struct super_block *sb = inode->i_sb;
	int error;

	error = setattr_prepare(&init_user_ns, dentry, attr);
	if (error)
		return error;

	if ((attr->ia_valid & ATTR_UID) &&
	    UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET) &&
	    !uid_eq(attr->ia_uid, UDF_SB(sb)->s_uid))
		return -EPERM;
	if ((attr->ia_valid & ATTR_GID) &&
	    UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET) &&
	    !gid_eq(attr->ia_gid, UDF_SB(sb)->s_gid))
		return -EPERM;

	if ((attr->ia_valid & ATTR_SIZE) &&
	    attr->ia_size != i_size_read(inode)) {
		error = udf_setsize(inode, attr->ia_size);
		if (error)
			return error;
	}

	if (attr->ia_valid & ATTR_MODE)
		udf_update_extra_perms(inode, attr->ia_mode);

	setattr_copy(&init_user_ns, inode, attr);
	mark_inode_dirty(inode);
	return 0;
}

const struct inode_operations udf_file_inode_operations = {
	.setattr		= udf_setattr,
};