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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 <linux/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/pagemap.h>
36 #include <linux/uio.h>
37
38 #include "udf_i.h"
39 #include "udf_sb.h"
40
41 static void __udf_adinicb_readpage(struct page *page)
42 {
43 struct inode *inode = page->mapping->host;
44 char *kaddr;
45 struct udf_inode_info *iinfo = UDF_I(inode);
46
47 kaddr = kmap_atomic(page);
48 memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
49 memset(kaddr + inode->i_size, 0, PAGE_SIZE - inode->i_size);
50 flush_dcache_page(page);
51 SetPageUptodate(page);
52 kunmap_atomic(kaddr);
53 }
54
55 static int udf_adinicb_readpage(struct file *file, struct page *page)
56 {
57 BUG_ON(!PageLocked(page));
58 __udf_adinicb_readpage(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_atomic(page);
74 memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
75 SetPageUptodate(page);
76 kunmap_atomic(kaddr);
77 mark_inode_dirty(inode);
78 unlock_page(page);
79
80 return 0;
81 }
82
83 static int udf_adinicb_write_begin(struct file *file,
84 struct address_space *mapping, loff_t pos,
85 unsigned len, unsigned flags, struct page **pagep,
86 void **fsdata)
87 {
88 struct page *page;
89
90 if (WARN_ON_ONCE(pos >= PAGE_SIZE))
91 return -EIO;
92 page = grab_cache_page_write_begin(mapping, 0, flags);
93 if (!page)
94 return -ENOMEM;
95 *pagep = page;
96
97 if (!PageUptodate(page))
98 __udf_adinicb_readpage(page);
99 return 0;
100 }
101
102 static ssize_t udf_adinicb_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
103 {
104 /* Fallback to buffered I/O. */
105 return 0;
106 }
107
108 static int udf_adinicb_write_end(struct file *file, struct address_space *mapping,
109 loff_t pos, unsigned len, unsigned copied,
110 struct page *page, void *fsdata)
111 {
112 struct inode *inode = page->mapping->host;
113 loff_t last_pos = pos + copied;
114 if (last_pos > inode->i_size)
115 i_size_write(inode, last_pos);
116 set_page_dirty(page);
117 unlock_page(page);
118 put_page(page);
119 return copied;
120 }
121
122 const struct address_space_operations udf_adinicb_aops = {
123 .readpage = udf_adinicb_readpage,
124 .writepage = udf_adinicb_writepage,
125 .write_begin = udf_adinicb_write_begin,
126 .write_end = udf_adinicb_write_end,
127 .direct_IO = udf_adinicb_direct_IO,
128 };
129
130 static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
131 {
132 ssize_t retval;
133 struct file *file = iocb->ki_filp;
134 struct inode *inode = file_inode(file);
135 struct udf_inode_info *iinfo = UDF_I(inode);
136 int err;
137
138 inode_lock(inode);
139
140 retval = generic_write_checks(iocb, from);
141 if (retval <= 0)
142 goto out;
143
144 down_write(&iinfo->i_data_sem);
145 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
146 loff_t end = iocb->ki_pos + iov_iter_count(from);
147
148 if (inode->i_sb->s_blocksize <
149 (udf_file_entry_alloc_offset(inode) + end)) {
150 err = udf_expand_file_adinicb(inode);
151 if (err) {
152 inode_unlock(inode);
153 udf_debug("udf_expand_adinicb: err=%d\n", err);
154 return err;
155 }
156 } else {
157 iinfo->i_lenAlloc = max(end, inode->i_size);
158 up_write(&iinfo->i_data_sem);
159 }
160 } else
161 up_write(&iinfo->i_data_sem);
162
163 retval = __generic_file_write_iter(iocb, from);
164 out:
165 inode_unlock(inode);
166
167 if (retval > 0) {
168 mark_inode_dirty(inode);
169 retval = generic_write_sync(iocb, retval);
170 }
171
172 return retval;
173 }
174
175 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
176 {
177 struct inode *inode = file_inode(filp);
178 long old_block, new_block;
179 int result;
180
181 if (inode_permission(inode, MAY_READ) != 0) {
182 udf_debug("no permission to access inode %lu\n", inode->i_ino);
183 return -EPERM;
184 }
185
186 if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) ||
187 (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) {
188 udf_debug("invalid argument to udf_ioctl\n");
189 return -EINVAL;
190 }
191
192 switch (cmd) {
193 case UDF_GETVOLIDENT:
194 if (copy_to_user((char __user *)arg,
195 UDF_SB(inode->i_sb)->s_volume_ident, 32))
196 return -EFAULT;
197 return 0;
198 case UDF_RELOCATE_BLOCKS:
199 if (!capable(CAP_SYS_ADMIN))
200 return -EPERM;
201 if (get_user(old_block, (long __user *)arg))
202 return -EFAULT;
203 result = udf_relocate_blocks(inode->i_sb,
204 old_block, &new_block);
205 if (result == 0)
206 result = put_user(new_block, (long __user *)arg);
207 return result;
208 case UDF_GETEASIZE:
209 return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
210 case UDF_GETEABLOCK:
211 return copy_to_user((char __user *)arg,
212 UDF_I(inode)->i_ext.i_data,
213 UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
214 default:
215 return -ENOIOCTLCMD;
216 }
217
218 return 0;
219 }
220
221 static int udf_release_file(struct inode *inode, struct file *filp)
222 {
223 if (filp->f_mode & FMODE_WRITE &&
224 atomic_read(&inode->i_writecount) == 1) {
225 /*
226 * Grab i_mutex to avoid races with writes changing i_size
227 * while we are running.
228 */
229 inode_lock(inode);
230 down_write(&UDF_I(inode)->i_data_sem);
231 udf_discard_prealloc(inode);
232 udf_truncate_tail_extent(inode);
233 up_write(&UDF_I(inode)->i_data_sem);
234 inode_unlock(inode);
235 }
236 return 0;
237 }
238
239 const struct file_operations udf_file_operations = {
240 .read_iter = generic_file_read_iter,
241 .unlocked_ioctl = udf_ioctl,
242 .open = generic_file_open,
243 .mmap = generic_file_mmap,
244 .write_iter = udf_file_write_iter,
245 .release = udf_release_file,
246 .fsync = generic_file_fsync,
247 .splice_read = generic_file_splice_read,
248 .llseek = generic_file_llseek,
249 };
250
251 static int udf_setattr(struct dentry *dentry, struct iattr *attr)
252 {
253 struct inode *inode = d_inode(dentry);
254 int error;
255
256 error = setattr_prepare(dentry, attr);
257 if (error)
258 return error;
259
260 if ((attr->ia_valid & ATTR_SIZE) &&
261 attr->ia_size != i_size_read(inode)) {
262 error = udf_setsize(inode, attr->ia_size);
263 if (error)
264 return error;
265 }
266
267 setattr_copy(inode, attr);
268 mark_inode_dirty(inode);
269 return 0;
270 }
271
272 const struct inode_operations udf_file_inode_operations = {
273 .setattr = udf_setattr,
274 };