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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 | loff_t isize = i_size_read(inode); | |
47 | ||
48 | /* | |
49 | * We have to be careful here as truncate can change i_size under us. | |
50 | * So just sample it once and use the same value everywhere. | |
51 | */ | |
52 | kaddr = kmap_atomic(page); | |
53 | memcpy(kaddr, iinfo->i_data + iinfo->i_lenEAttr, isize); | |
54 | memset(kaddr + isize, 0, PAGE_SIZE - isize); | |
55 | flush_dcache_page(page); | |
56 | SetPageUptodate(page); | |
57 | kunmap_atomic(kaddr); | |
58 | } | |
59 | ||
60 | static int udf_adinicb_readpage(struct file *file, struct page *page) | |
61 | { | |
62 | BUG_ON(!PageLocked(page)); | |
63 | __udf_adinicb_readpage(page); | |
64 | unlock_page(page); | |
65 | ||
66 | return 0; | |
67 | } | |
68 | ||
69 | static int udf_adinicb_writepage(struct page *page, | |
70 | struct writeback_control *wbc) | |
71 | { | |
72 | struct inode *inode = page->mapping->host; | |
73 | char *kaddr; | |
74 | struct udf_inode_info *iinfo = UDF_I(inode); | |
75 | ||
76 | BUG_ON(!PageLocked(page)); | |
77 | ||
78 | kaddr = kmap_atomic(page); | |
79 | memcpy(iinfo->i_data + iinfo->i_lenEAttr, kaddr, i_size_read(inode)); | |
80 | SetPageUptodate(page); | |
81 | kunmap_atomic(kaddr); | |
82 | mark_inode_dirty(inode); | |
83 | unlock_page(page); | |
84 | ||
85 | return 0; | |
86 | } | |
87 | ||
88 | static int udf_adinicb_write_begin(struct file *file, | |
89 | struct address_space *mapping, loff_t pos, | |
90 | unsigned len, unsigned flags, struct page **pagep, | |
91 | void **fsdata) | |
92 | { | |
93 | struct page *page; | |
94 | ||
95 | if (WARN_ON_ONCE(pos >= PAGE_SIZE)) | |
96 | return -EIO; | |
97 | page = grab_cache_page_write_begin(mapping, 0, flags); | |
98 | if (!page) | |
99 | return -ENOMEM; | |
100 | *pagep = page; | |
101 | ||
102 | if (!PageUptodate(page)) | |
103 | __udf_adinicb_readpage(page); | |
104 | return 0; | |
105 | } | |
106 | ||
107 | static ssize_t udf_adinicb_direct_IO(struct kiocb *iocb, struct iov_iter *iter) | |
108 | { | |
109 | /* Fallback to buffered I/O. */ | |
110 | return 0; | |
111 | } | |
112 | ||
113 | static int udf_adinicb_write_end(struct file *file, struct address_space *mapping, | |
114 | loff_t pos, unsigned len, unsigned copied, | |
115 | struct page *page, void *fsdata) | |
116 | { | |
117 | struct inode *inode = page->mapping->host; | |
118 | loff_t last_pos = pos + copied; | |
119 | if (last_pos > inode->i_size) | |
120 | i_size_write(inode, last_pos); | |
121 | set_page_dirty(page); | |
122 | unlock_page(page); | |
123 | put_page(page); | |
124 | return copied; | |
125 | } | |
126 | ||
127 | const struct address_space_operations udf_adinicb_aops = { | |
128 | .set_page_dirty = __set_page_dirty_buffers, | |
129 | .readpage = udf_adinicb_readpage, | |
130 | .writepage = udf_adinicb_writepage, | |
131 | .write_begin = udf_adinicb_write_begin, | |
132 | .write_end = udf_adinicb_write_end, | |
133 | .direct_IO = udf_adinicb_direct_IO, | |
134 | }; | |
135 | ||
136 | static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from) | |
137 | { | |
138 | ssize_t retval; | |
139 | struct file *file = iocb->ki_filp; | |
140 | struct inode *inode = file_inode(file); | |
141 | struct udf_inode_info *iinfo = UDF_I(inode); | |
142 | int err; | |
143 | ||
144 | inode_lock(inode); | |
145 | ||
146 | retval = generic_write_checks(iocb, from); | |
147 | if (retval <= 0) | |
148 | goto out; | |
149 | ||
150 | down_write(&iinfo->i_data_sem); | |
151 | if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) { | |
152 | loff_t end = iocb->ki_pos + iov_iter_count(from); | |
153 | ||
154 | if (inode->i_sb->s_blocksize < | |
155 | (udf_file_entry_alloc_offset(inode) + end)) { | |
156 | err = udf_expand_file_adinicb(inode); | |
157 | if (err) { | |
158 | inode_unlock(inode); | |
159 | udf_debug("udf_expand_adinicb: err=%d\n", err); | |
160 | return err; | |
161 | } | |
162 | } else { | |
163 | iinfo->i_lenAlloc = max(end, inode->i_size); | |
164 | up_write(&iinfo->i_data_sem); | |
165 | } | |
166 | } else | |
167 | up_write(&iinfo->i_data_sem); | |
168 | ||
169 | retval = __generic_file_write_iter(iocb, from); | |
170 | out: | |
171 | inode_unlock(inode); | |
172 | ||
173 | if (retval > 0) { | |
174 | mark_inode_dirty(inode); | |
175 | retval = generic_write_sync(iocb, retval); | |
176 | } | |
177 | ||
178 | return retval; | |
179 | } | |
180 | ||
181 | long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) | |
182 | { | |
183 | struct inode *inode = file_inode(filp); | |
184 | long old_block, new_block; | |
185 | int result; | |
186 | ||
187 | if (file_permission(filp, MAY_READ) != 0) { | |
188 | udf_debug("no permission to access inode %lu\n", inode->i_ino); | |
189 | return -EPERM; | |
190 | } | |
191 | ||
192 | if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) || | |
193 | (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) { | |
194 | udf_debug("invalid argument to udf_ioctl\n"); | |
195 | return -EINVAL; | |
196 | } | |
197 | ||
198 | switch (cmd) { | |
199 | case UDF_GETVOLIDENT: | |
200 | if (copy_to_user((char __user *)arg, | |
201 | UDF_SB(inode->i_sb)->s_volume_ident, 32)) | |
202 | return -EFAULT; | |
203 | return 0; | |
204 | case UDF_RELOCATE_BLOCKS: | |
205 | if (!capable(CAP_SYS_ADMIN)) | |
206 | return -EPERM; | |
207 | if (get_user(old_block, (long __user *)arg)) | |
208 | return -EFAULT; | |
209 | result = udf_relocate_blocks(inode->i_sb, | |
210 | old_block, &new_block); | |
211 | if (result == 0) | |
212 | result = put_user(new_block, (long __user *)arg); | |
213 | return result; | |
214 | case UDF_GETEASIZE: | |
215 | return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg); | |
216 | case UDF_GETEABLOCK: | |
217 | return copy_to_user((char __user *)arg, | |
218 | UDF_I(inode)->i_data, | |
219 | UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0; | |
220 | default: | |
221 | return -ENOIOCTLCMD; | |
222 | } | |
223 | ||
224 | return 0; | |
225 | } | |
226 | ||
227 | static int udf_release_file(struct inode *inode, struct file *filp) | |
228 | { | |
229 | if (filp->f_mode & FMODE_WRITE && | |
230 | atomic_read(&inode->i_writecount) == 1) { | |
231 | /* | |
232 | * Grab i_mutex to avoid races with writes changing i_size | |
233 | * while we are running. | |
234 | */ | |
235 | inode_lock(inode); | |
236 | down_write(&UDF_I(inode)->i_data_sem); | |
237 | udf_discard_prealloc(inode); | |
238 | udf_truncate_tail_extent(inode); | |
239 | up_write(&UDF_I(inode)->i_data_sem); | |
240 | inode_unlock(inode); | |
241 | } | |
242 | return 0; | |
243 | } | |
244 | ||
245 | const struct file_operations udf_file_operations = { | |
246 | .read_iter = generic_file_read_iter, | |
247 | .unlocked_ioctl = udf_ioctl, | |
248 | .open = generic_file_open, | |
249 | .mmap = generic_file_mmap, | |
250 | .write_iter = udf_file_write_iter, | |
251 | .release = udf_release_file, | |
252 | .fsync = generic_file_fsync, | |
253 | .splice_read = generic_file_splice_read, | |
254 | .llseek = generic_file_llseek, | |
255 | }; | |
256 | ||
257 | static int udf_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, | |
258 | struct iattr *attr) | |
259 | { | |
260 | struct inode *inode = d_inode(dentry); | |
261 | struct super_block *sb = inode->i_sb; | |
262 | int error; | |
263 | ||
264 | error = setattr_prepare(&init_user_ns, dentry, attr); | |
265 | if (error) | |
266 | return error; | |
267 | ||
268 | if ((attr->ia_valid & ATTR_UID) && | |
269 | UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET) && | |
270 | !uid_eq(attr->ia_uid, UDF_SB(sb)->s_uid)) | |
271 | return -EPERM; | |
272 | if ((attr->ia_valid & ATTR_GID) && | |
273 | UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET) && | |
274 | !gid_eq(attr->ia_gid, UDF_SB(sb)->s_gid)) | |
275 | return -EPERM; | |
276 | ||
277 | if ((attr->ia_valid & ATTR_SIZE) && | |
278 | attr->ia_size != i_size_read(inode)) { | |
279 | error = udf_setsize(inode, attr->ia_size); | |
280 | if (error) | |
281 | return error; | |
282 | } | |
283 | ||
284 | if (attr->ia_valid & ATTR_MODE) | |
285 | udf_update_extra_perms(inode, attr->ia_mode); | |
286 | ||
287 | setattr_copy(&init_user_ns, inode, attr); | |
288 | mark_inode_dirty(inode); | |
289 | return 0; | |
290 | } | |
291 | ||
292 | const struct inode_operations udf_file_inode_operations = { | |
293 | .setattr = udf_setattr, | |
294 | }; |