xref: /linux/fs/udf/file.c (revision b3b77c8caef1750ebeea1054e39e358550ea9f55)
1 /*
2  * file.c
3  *
4  * PURPOSE
5  *  File handling routines for the OSTA-UDF(tm) filesystem.
6  *
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>
30 #include <asm/uaccess.h>
31 #include <linux/kernel.h>
32 #include <linux/string.h> /* memset */
33 #include <linux/capability.h>
34 #include <linux/errno.h>
35 #include <linux/smp_lock.h>
36 #include <linux/pagemap.h>
37 #include <linux/quotaops.h>
38 #include <linux/buffer_head.h>
39 #include <linux/aio.h>
40 #include <linux/smp_lock.h>
41 
42 #include "udf_i.h"
43 #include "udf_sb.h"
44 
45 static int udf_adinicb_readpage(struct file *file, struct page *page)
46 {
47 	struct inode *inode = page->mapping->host;
48 	char *kaddr;
49 	struct udf_inode_info *iinfo = UDF_I(inode);
50 
51 	BUG_ON(!PageLocked(page));
52 
53 	kaddr = kmap(page);
54 	memset(kaddr, 0, PAGE_CACHE_SIZE);
55 	memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
56 	flush_dcache_page(page);
57 	SetPageUptodate(page);
58 	kunmap(page);
59 	unlock_page(page);
60 
61 	return 0;
62 }
63 
64 static int udf_adinicb_writepage(struct page *page,
65 				 struct writeback_control *wbc)
66 {
67 	struct inode *inode = page->mapping->host;
68 	char *kaddr;
69 	struct udf_inode_info *iinfo = UDF_I(inode);
70 
71 	BUG_ON(!PageLocked(page));
72 
73 	kaddr = kmap(page);
74 	memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
75 	mark_inode_dirty(inode);
76 	SetPageUptodate(page);
77 	kunmap(page);
78 	unlock_page(page);
79 
80 	return 0;
81 }
82 
83 static int udf_adinicb_write_end(struct file *file,
84 			struct address_space *mapping,
85 			loff_t pos, unsigned len, unsigned copied,
86 			struct page *page, void *fsdata)
87 {
88 	struct inode *inode = mapping->host;
89 	unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
90 	char *kaddr;
91 	struct udf_inode_info *iinfo = UDF_I(inode);
92 
93 	kaddr = kmap_atomic(page, KM_USER0);
94 	memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr + offset,
95 		kaddr + offset, copied);
96 	kunmap_atomic(kaddr, KM_USER0);
97 
98 	return simple_write_end(file, mapping, pos, len, copied, page, fsdata);
99 }
100 
101 const struct address_space_operations udf_adinicb_aops = {
102 	.readpage	= udf_adinicb_readpage,
103 	.writepage	= udf_adinicb_writepage,
104 	.sync_page	= block_sync_page,
105 	.write_begin = simple_write_begin,
106 	.write_end = udf_adinicb_write_end,
107 };
108 
109 static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
110 				  unsigned long nr_segs, loff_t ppos)
111 {
112 	ssize_t retval;
113 	struct file *file = iocb->ki_filp;
114 	struct inode *inode = file->f_path.dentry->d_inode;
115 	int err, pos;
116 	size_t count = iocb->ki_left;
117 	struct udf_inode_info *iinfo = UDF_I(inode);
118 
119 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
120 		if (file->f_flags & O_APPEND)
121 			pos = inode->i_size;
122 		else
123 			pos = ppos;
124 
125 		if (inode->i_sb->s_blocksize <
126 				(udf_file_entry_alloc_offset(inode) +
127 						pos + count)) {
128 			udf_expand_file_adinicb(inode, pos + count, &err);
129 			if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
130 				udf_debug("udf_expand_adinicb: err=%d\n", err);
131 				return err;
132 			}
133 		} else {
134 			if (pos + count > inode->i_size)
135 				iinfo->i_lenAlloc = pos + count;
136 			else
137 				iinfo->i_lenAlloc = inode->i_size;
138 		}
139 	}
140 
141 	retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
142 	if (retval > 0)
143 		mark_inode_dirty(inode);
144 
145 	return retval;
146 }
147 
148 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
149 {
150 	struct inode *inode = filp->f_dentry->d_inode;
151 	long old_block, new_block;
152 	int result = -EINVAL;
153 
154 	lock_kernel();
155 
156 	if (file_permission(filp, MAY_READ) != 0) {
157 		udf_debug("no permission to access inode %lu\n", inode->i_ino);
158 		result = -EPERM;
159 		goto out;
160 	}
161 
162 	if (!arg) {
163 		udf_debug("invalid argument to udf_ioctl\n");
164 		result = -EINVAL;
165 		goto out;
166 	}
167 
168 	switch (cmd) {
169 	case UDF_GETVOLIDENT:
170 		if (copy_to_user((char __user *)arg,
171 				 UDF_SB(inode->i_sb)->s_volume_ident, 32))
172 			result = -EFAULT;
173 		else
174 			result = 0;
175 		goto out;
176 	case UDF_RELOCATE_BLOCKS:
177 		if (!capable(CAP_SYS_ADMIN)) {
178 			result = -EACCES;
179 			goto out;
180 		}
181 		if (get_user(old_block, (long __user *)arg)) {
182 			result = -EFAULT;
183 			goto out;
184 		}
185 		result = udf_relocate_blocks(inode->i_sb,
186 						old_block, &new_block);
187 		if (result == 0)
188 			result = put_user(new_block, (long __user *)arg);
189 		goto out;
190 	case UDF_GETEASIZE:
191 		result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
192 		goto out;
193 	case UDF_GETEABLOCK:
194 		result = copy_to_user((char __user *)arg,
195 				      UDF_I(inode)->i_ext.i_data,
196 				      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
197 		goto out;
198 	}
199 
200 out:
201 	unlock_kernel();
202 	return result;
203 }
204 
205 static int udf_release_file(struct inode *inode, struct file *filp)
206 {
207 	if (filp->f_mode & FMODE_WRITE) {
208 		mutex_lock(&inode->i_mutex);
209 		lock_kernel();
210 		udf_discard_prealloc(inode);
211 		udf_truncate_tail_extent(inode);
212 		unlock_kernel();
213 		mutex_unlock(&inode->i_mutex);
214 	}
215 	return 0;
216 }
217 
218 const struct file_operations udf_file_operations = {
219 	.read			= do_sync_read,
220 	.aio_read		= generic_file_aio_read,
221 	.unlocked_ioctl		= udf_ioctl,
222 	.open			= dquot_file_open,
223 	.mmap			= generic_file_mmap,
224 	.write			= do_sync_write,
225 	.aio_write		= udf_file_aio_write,
226 	.release		= udf_release_file,
227 	.fsync			= simple_fsync,
228 	.splice_read		= generic_file_splice_read,
229 	.llseek			= generic_file_llseek,
230 };
231 
232 int udf_setattr(struct dentry *dentry, struct iattr *iattr)
233 {
234 	struct inode *inode = dentry->d_inode;
235 	int error;
236 
237 	error = inode_change_ok(inode, iattr);
238 	if (error)
239 		return error;
240 
241 	if (is_quota_modification(inode, iattr))
242 		dquot_initialize(inode);
243 
244 	if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
245             (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
246 		error = dquot_transfer(inode, iattr);
247 		if (error)
248 			return error;
249 	}
250 
251 	return inode_setattr(inode, iattr);
252 }
253 
254 const struct inode_operations udf_file_inode_operations = {
255 	.truncate		= udf_truncate,
256 	.setattr		= udf_setattr,
257 };
258