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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(page); | |
48 | memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size); | |
49 | memset(kaddr + inode->i_size, 0, PAGE_CACHE_SIZE - inode->i_size); | |
50 | flush_dcache_page(page); | |
51 | SetPageUptodate(page); | |
52 | kunmap(page); | |
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(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_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_CACHE_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) && len != PAGE_CACHE_SIZE) | |
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 | loff_t offset) | |
104 | { | |
105 | /* Fallback to buffered I/O. */ | |
106 | return 0; | |
107 | } | |
108 | ||
109 | const struct address_space_operations udf_adinicb_aops = { | |
110 | .readpage = udf_adinicb_readpage, | |
111 | .writepage = udf_adinicb_writepage, | |
112 | .write_begin = udf_adinicb_write_begin, | |
113 | .write_end = simple_write_end, | |
114 | .direct_IO = udf_adinicb_direct_IO, | |
115 | }; | |
116 | ||
117 | static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from) | |
118 | { | |
119 | ssize_t retval; | |
120 | struct file *file = iocb->ki_filp; | |
121 | struct inode *inode = file_inode(file); | |
122 | struct udf_inode_info *iinfo = UDF_I(inode); | |
123 | int err; | |
124 | ||
125 | mutex_lock(&inode->i_mutex); | |
126 | ||
127 | retval = generic_write_checks(iocb, from); | |
128 | if (retval <= 0) | |
129 | goto out; | |
130 | ||
131 | down_write(&iinfo->i_data_sem); | |
132 | if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) { | |
133 | loff_t end = iocb->ki_pos + iov_iter_count(from); | |
134 | ||
135 | if (inode->i_sb->s_blocksize < | |
136 | (udf_file_entry_alloc_offset(inode) + end)) { | |
137 | err = udf_expand_file_adinicb(inode); | |
138 | if (err) { | |
139 | mutex_unlock(&inode->i_mutex); | |
140 | udf_debug("udf_expand_adinicb: err=%d\n", err); | |
141 | return err; | |
142 | } | |
143 | } else { | |
144 | iinfo->i_lenAlloc = max(end, inode->i_size); | |
145 | up_write(&iinfo->i_data_sem); | |
146 | } | |
147 | } else | |
148 | up_write(&iinfo->i_data_sem); | |
149 | ||
150 | retval = __generic_file_write_iter(iocb, from); | |
151 | out: | |
152 | mutex_unlock(&inode->i_mutex); | |
153 | ||
154 | if (retval > 0) { | |
155 | mark_inode_dirty(inode); | |
156 | err = generic_write_sync(file, iocb->ki_pos - retval, retval); | |
157 | if (err < 0) | |
158 | retval = err; | |
159 | } | |
160 | ||
161 | return retval; | |
162 | } | |
163 | ||
164 | long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) | |
165 | { | |
166 | struct inode *inode = file_inode(filp); | |
167 | long old_block, new_block; | |
168 | int result = -EINVAL; | |
169 | ||
170 | if (inode_permission(inode, MAY_READ) != 0) { | |
171 | udf_debug("no permission to access inode %lu\n", inode->i_ino); | |
172 | result = -EPERM; | |
173 | goto out; | |
174 | } | |
175 | ||
176 | if (!arg) { | |
177 | udf_debug("invalid argument to udf_ioctl\n"); | |
178 | result = -EINVAL; | |
179 | goto out; | |
180 | } | |
181 | ||
182 | switch (cmd) { | |
183 | case UDF_GETVOLIDENT: | |
184 | if (copy_to_user((char __user *)arg, | |
185 | UDF_SB(inode->i_sb)->s_volume_ident, 32)) | |
186 | result = -EFAULT; | |
187 | else | |
188 | result = 0; | |
189 | goto out; | |
190 | case UDF_RELOCATE_BLOCKS: | |
191 | if (!capable(CAP_SYS_ADMIN)) { | |
192 | result = -EPERM; | |
193 | goto out; | |
194 | } | |
195 | if (get_user(old_block, (long __user *)arg)) { | |
196 | result = -EFAULT; | |
197 | goto out; | |
198 | } | |
199 | result = udf_relocate_blocks(inode->i_sb, | |
200 | old_block, &new_block); | |
201 | if (result == 0) | |
202 | result = put_user(new_block, (long __user *)arg); | |
203 | goto out; | |
204 | case UDF_GETEASIZE: | |
205 | result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg); | |
206 | goto out; | |
207 | case UDF_GETEABLOCK: | |
208 | result = copy_to_user((char __user *)arg, | |
209 | UDF_I(inode)->i_ext.i_data, | |
210 | UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0; | |
211 | goto out; | |
212 | } | |
213 | ||
214 | out: | |
215 | return result; | |
216 | } | |
217 | ||
218 | static int udf_release_file(struct inode *inode, struct file *filp) | |
219 | { | |
220 | if (filp->f_mode & FMODE_WRITE && | |
221 | atomic_read(&inode->i_writecount) == 1) { | |
222 | /* | |
223 | * Grab i_mutex to avoid races with writes changing i_size | |
224 | * while we are running. | |
225 | */ | |
226 | mutex_lock(&inode->i_mutex); | |
227 | down_write(&UDF_I(inode)->i_data_sem); | |
228 | udf_discard_prealloc(inode); | |
229 | udf_truncate_tail_extent(inode); | |
230 | up_write(&UDF_I(inode)->i_data_sem); | |
231 | mutex_unlock(&inode->i_mutex); | |
232 | } | |
233 | return 0; | |
234 | } | |
235 | ||
236 | const struct file_operations udf_file_operations = { | |
237 | .read_iter = generic_file_read_iter, | |
238 | .unlocked_ioctl = udf_ioctl, | |
239 | .open = generic_file_open, | |
240 | .mmap = generic_file_mmap, | |
241 | .write_iter = udf_file_write_iter, | |
242 | .release = udf_release_file, | |
243 | .fsync = generic_file_fsync, | |
244 | .splice_read = generic_file_splice_read, | |
245 | .llseek = generic_file_llseek, | |
246 | }; | |
247 | ||
248 | static int udf_setattr(struct dentry *dentry, struct iattr *attr) | |
249 | { | |
250 | struct inode *inode = d_inode(dentry); | |
251 | int error; | |
252 | ||
253 | error = inode_change_ok(inode, attr); | |
254 | if (error) | |
255 | return error; | |
256 | ||
257 | if ((attr->ia_valid & ATTR_SIZE) && | |
258 | attr->ia_size != i_size_read(inode)) { | |
259 | error = udf_setsize(inode, attr->ia_size); | |
260 | if (error) | |
261 | return error; | |
262 | } | |
263 | ||
264 | setattr_copy(inode, attr); | |
265 | mark_inode_dirty(inode); | |
266 | return 0; | |
267 | } | |
268 | ||
269 | const struct inode_operations udf_file_inode_operations = { | |
270 | .setattr = udf_setattr, | |
271 | }; |