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1da177e4 LT |
1 | /* |
2 | * linux/fs/adfs/inode.c | |
3 | * | |
4 | * Copyright (C) 1997-1999 Russell King | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | #include <linux/errno.h> | |
11 | #include <linux/fs.h> | |
12 | #include <linux/adfs_fs.h> | |
13 | #include <linux/time.h> | |
14 | #include <linux/stat.h> | |
15 | #include <linux/string.h> | |
16 | #include <linux/mm.h> | |
17 | #include <linux/smp_lock.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/buffer_head.h> | |
20 | ||
21 | #include "adfs.h" | |
22 | ||
23 | /* | |
24 | * Lookup/Create a block at offset 'block' into 'inode'. We currently do | |
25 | * not support creation of new blocks, so we return -EIO for this case. | |
26 | */ | |
27 | static int | |
28 | adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh, | |
29 | int create) | |
30 | { | |
31 | if (block < 0) | |
32 | goto abort_negative; | |
33 | ||
34 | if (!create) { | |
35 | if (block >= inode->i_blocks) | |
36 | goto abort_toobig; | |
37 | ||
38 | block = __adfs_block_map(inode->i_sb, inode->i_ino, block); | |
39 | if (block) | |
40 | map_bh(bh, inode->i_sb, block); | |
41 | return 0; | |
42 | } | |
43 | /* don't support allocation of blocks yet */ | |
44 | return -EIO; | |
45 | ||
46 | abort_negative: | |
47 | adfs_error(inode->i_sb, "block %d < 0", block); | |
48 | return -EIO; | |
49 | ||
50 | abort_toobig: | |
51 | return 0; | |
52 | } | |
53 | ||
54 | static int adfs_writepage(struct page *page, struct writeback_control *wbc) | |
55 | { | |
56 | return block_write_full_page(page, adfs_get_block, wbc); | |
57 | } | |
58 | ||
59 | static int adfs_readpage(struct file *file, struct page *page) | |
60 | { | |
61 | return block_read_full_page(page, adfs_get_block); | |
62 | } | |
63 | ||
64 | static int adfs_prepare_write(struct file *file, struct page *page, unsigned int from, unsigned int to) | |
65 | { | |
66 | return cont_prepare_write(page, from, to, adfs_get_block, | |
67 | &ADFS_I(page->mapping->host)->mmu_private); | |
68 | } | |
69 | ||
70 | static sector_t _adfs_bmap(struct address_space *mapping, sector_t block) | |
71 | { | |
72 | return generic_block_bmap(mapping, block, adfs_get_block); | |
73 | } | |
74 | ||
75 | static struct address_space_operations adfs_aops = { | |
76 | .readpage = adfs_readpage, | |
77 | .writepage = adfs_writepage, | |
78 | .sync_page = block_sync_page, | |
79 | .prepare_write = adfs_prepare_write, | |
80 | .commit_write = generic_commit_write, | |
81 | .bmap = _adfs_bmap | |
82 | }; | |
83 | ||
84 | static inline unsigned int | |
85 | adfs_filetype(struct inode *inode) | |
86 | { | |
87 | unsigned int type; | |
88 | ||
89 | if (ADFS_I(inode)->stamped) | |
90 | type = (ADFS_I(inode)->loadaddr >> 8) & 0xfff; | |
91 | else | |
92 | type = (unsigned int) -1; | |
93 | ||
94 | return type; | |
95 | } | |
96 | ||
97 | /* | |
98 | * Convert ADFS attributes and filetype to Linux permission. | |
99 | */ | |
100 | static umode_t | |
101 | adfs_atts2mode(struct super_block *sb, struct inode *inode) | |
102 | { | |
103 | unsigned int filetype, attr = ADFS_I(inode)->attr; | |
104 | umode_t mode, rmask; | |
105 | struct adfs_sb_info *asb = ADFS_SB(sb); | |
106 | ||
107 | if (attr & ADFS_NDA_DIRECTORY) { | |
108 | mode = S_IRUGO & asb->s_owner_mask; | |
109 | return S_IFDIR | S_IXUGO | mode; | |
110 | } | |
111 | ||
112 | filetype = adfs_filetype(inode); | |
113 | ||
114 | switch (filetype) { | |
115 | case 0xfc0: /* LinkFS */ | |
116 | return S_IFLNK|S_IRWXUGO; | |
117 | ||
118 | case 0xfe6: /* UnixExec */ | |
119 | rmask = S_IRUGO | S_IXUGO; | |
120 | break; | |
121 | ||
122 | default: | |
123 | rmask = S_IRUGO; | |
124 | } | |
125 | ||
126 | mode = S_IFREG; | |
127 | ||
128 | if (attr & ADFS_NDA_OWNER_READ) | |
129 | mode |= rmask & asb->s_owner_mask; | |
130 | ||
131 | if (attr & ADFS_NDA_OWNER_WRITE) | |
132 | mode |= S_IWUGO & asb->s_owner_mask; | |
133 | ||
134 | if (attr & ADFS_NDA_PUBLIC_READ) | |
135 | mode |= rmask & asb->s_other_mask; | |
136 | ||
137 | if (attr & ADFS_NDA_PUBLIC_WRITE) | |
138 | mode |= S_IWUGO & asb->s_other_mask; | |
139 | return mode; | |
140 | } | |
141 | ||
142 | /* | |
143 | * Convert Linux permission to ADFS attribute. We try to do the reverse | |
144 | * of atts2mode, but there is not a 1:1 translation. | |
145 | */ | |
146 | static int | |
147 | adfs_mode2atts(struct super_block *sb, struct inode *inode) | |
148 | { | |
149 | umode_t mode; | |
150 | int attr; | |
151 | struct adfs_sb_info *asb = ADFS_SB(sb); | |
152 | ||
153 | /* FIXME: should we be able to alter a link? */ | |
154 | if (S_ISLNK(inode->i_mode)) | |
155 | return ADFS_I(inode)->attr; | |
156 | ||
157 | if (S_ISDIR(inode->i_mode)) | |
158 | attr = ADFS_NDA_DIRECTORY; | |
159 | else | |
160 | attr = 0; | |
161 | ||
162 | mode = inode->i_mode & asb->s_owner_mask; | |
163 | if (mode & S_IRUGO) | |
164 | attr |= ADFS_NDA_OWNER_READ; | |
165 | if (mode & S_IWUGO) | |
166 | attr |= ADFS_NDA_OWNER_WRITE; | |
167 | ||
168 | mode = inode->i_mode & asb->s_other_mask; | |
169 | mode &= ~asb->s_owner_mask; | |
170 | if (mode & S_IRUGO) | |
171 | attr |= ADFS_NDA_PUBLIC_READ; | |
172 | if (mode & S_IWUGO) | |
173 | attr |= ADFS_NDA_PUBLIC_WRITE; | |
174 | ||
175 | return attr; | |
176 | } | |
177 | ||
178 | /* | |
179 | * Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time | |
180 | * referenced to 1 Jan 1900 (til 2248) | |
181 | */ | |
182 | static void | |
183 | adfs_adfs2unix_time(struct timespec *tv, struct inode *inode) | |
184 | { | |
185 | unsigned int high, low; | |
186 | ||
187 | if (ADFS_I(inode)->stamped == 0) | |
188 | goto cur_time; | |
189 | ||
190 | high = ADFS_I(inode)->loadaddr << 24; | |
191 | low = ADFS_I(inode)->execaddr; | |
192 | ||
193 | high |= low >> 8; | |
194 | low &= 255; | |
195 | ||
196 | /* Files dated pre 01 Jan 1970 00:00:00. */ | |
197 | if (high < 0x336e996a) | |
198 | goto too_early; | |
199 | ||
200 | /* Files dated post 18 Jan 2038 03:14:05. */ | |
201 | if (high >= 0x656e9969) | |
202 | goto too_late; | |
203 | ||
204 | /* discard 2208988800 (0x336e996a00) seconds of time */ | |
205 | high -= 0x336e996a; | |
206 | ||
207 | /* convert 40-bit centi-seconds to 32-bit seconds */ | |
208 | tv->tv_sec = (((high % 100) << 8) + low) / 100 + (high / 100 << 8); | |
209 | tv->tv_nsec = 0; | |
210 | return; | |
211 | ||
212 | cur_time: | |
213 | *tv = CURRENT_TIME_SEC; | |
214 | return; | |
215 | ||
216 | too_early: | |
217 | tv->tv_sec = tv->tv_nsec = 0; | |
218 | return; | |
219 | ||
220 | too_late: | |
221 | tv->tv_sec = 0x7ffffffd; | |
222 | tv->tv_nsec = 0; | |
223 | return; | |
224 | } | |
225 | ||
226 | /* | |
227 | * Convert an Unix time to ADFS time. We only do this if the entry has a | |
228 | * time/date stamp already. | |
229 | */ | |
230 | static void | |
231 | adfs_unix2adfs_time(struct inode *inode, unsigned int secs) | |
232 | { | |
233 | unsigned int high, low; | |
234 | ||
235 | if (ADFS_I(inode)->stamped) { | |
236 | /* convert 32-bit seconds to 40-bit centi-seconds */ | |
237 | low = (secs & 255) * 100; | |
238 | high = (secs / 256) * 100 + (low >> 8) + 0x336e996a; | |
239 | ||
240 | ADFS_I(inode)->loadaddr = (high >> 24) | | |
241 | (ADFS_I(inode)->loadaddr & ~0xff); | |
242 | ADFS_I(inode)->execaddr = (low & 255) | (high << 8); | |
243 | } | |
244 | } | |
245 | ||
246 | /* | |
247 | * Fill in the inode information from the object information. | |
248 | * | |
249 | * Note that this is an inode-less filesystem, so we can't use the inode | |
250 | * number to reference the metadata on the media. Instead, we use the | |
251 | * inode number to hold the object ID, which in turn will tell us where | |
252 | * the data is held. We also save the parent object ID, and with these | |
253 | * two, we can locate the metadata. | |
254 | * | |
255 | * This does mean that we rely on an objects parent remaining the same at | |
256 | * all times - we cannot cope with a cross-directory rename (yet). | |
257 | */ | |
258 | struct inode * | |
259 | adfs_iget(struct super_block *sb, struct object_info *obj) | |
260 | { | |
261 | struct inode *inode; | |
262 | ||
263 | inode = new_inode(sb); | |
264 | if (!inode) | |
265 | goto out; | |
266 | ||
267 | inode->i_uid = ADFS_SB(sb)->s_uid; | |
268 | inode->i_gid = ADFS_SB(sb)->s_gid; | |
269 | inode->i_ino = obj->file_id; | |
270 | inode->i_size = obj->size; | |
271 | inode->i_nlink = 2; | |
272 | inode->i_blksize = PAGE_SIZE; | |
273 | inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >> | |
274 | sb->s_blocksize_bits; | |
275 | ||
276 | /* | |
277 | * we need to save the parent directory ID so that | |
278 | * write_inode can update the directory information | |
279 | * for this file. This will need special handling | |
280 | * for cross-directory renames. | |
281 | */ | |
282 | ADFS_I(inode)->parent_id = obj->parent_id; | |
283 | ADFS_I(inode)->loadaddr = obj->loadaddr; | |
284 | ADFS_I(inode)->execaddr = obj->execaddr; | |
285 | ADFS_I(inode)->attr = obj->attr; | |
286 | ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000); | |
287 | ||
288 | inode->i_mode = adfs_atts2mode(sb, inode); | |
289 | adfs_adfs2unix_time(&inode->i_mtime, inode); | |
290 | inode->i_atime = inode->i_mtime; | |
291 | inode->i_ctime = inode->i_mtime; | |
292 | ||
293 | if (S_ISDIR(inode->i_mode)) { | |
294 | inode->i_op = &adfs_dir_inode_operations; | |
295 | inode->i_fop = &adfs_dir_operations; | |
296 | } else if (S_ISREG(inode->i_mode)) { | |
297 | inode->i_op = &adfs_file_inode_operations; | |
298 | inode->i_fop = &adfs_file_operations; | |
299 | inode->i_mapping->a_ops = &adfs_aops; | |
300 | ADFS_I(inode)->mmu_private = inode->i_size; | |
301 | } | |
302 | ||
303 | insert_inode_hash(inode); | |
304 | ||
305 | out: | |
306 | return inode; | |
307 | } | |
308 | ||
309 | /* | |
310 | * Validate and convert a changed access mode/time to their ADFS equivalents. | |
311 | * adfs_write_inode will actually write the information back to the directory | |
312 | * later. | |
313 | */ | |
314 | int | |
315 | adfs_notify_change(struct dentry *dentry, struct iattr *attr) | |
316 | { | |
317 | struct inode *inode = dentry->d_inode; | |
318 | struct super_block *sb = inode->i_sb; | |
319 | unsigned int ia_valid = attr->ia_valid; | |
320 | int error; | |
321 | ||
322 | lock_kernel(); | |
323 | ||
324 | error = inode_change_ok(inode, attr); | |
325 | ||
326 | /* | |
327 | * we can't change the UID or GID of any file - | |
328 | * we have a global UID/GID in the superblock | |
329 | */ | |
330 | if ((ia_valid & ATTR_UID && attr->ia_uid != ADFS_SB(sb)->s_uid) || | |
331 | (ia_valid & ATTR_GID && attr->ia_gid != ADFS_SB(sb)->s_gid)) | |
332 | error = -EPERM; | |
333 | ||
334 | if (error) | |
335 | goto out; | |
336 | ||
337 | if (ia_valid & ATTR_SIZE) | |
338 | error = vmtruncate(inode, attr->ia_size); | |
339 | ||
340 | if (error) | |
341 | goto out; | |
342 | ||
343 | if (ia_valid & ATTR_MTIME) { | |
344 | inode->i_mtime = attr->ia_mtime; | |
345 | adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec); | |
346 | } | |
347 | /* | |
348 | * FIXME: should we make these == to i_mtime since we don't | |
349 | * have the ability to represent them in our filesystem? | |
350 | */ | |
351 | if (ia_valid & ATTR_ATIME) | |
352 | inode->i_atime = attr->ia_atime; | |
353 | if (ia_valid & ATTR_CTIME) | |
354 | inode->i_ctime = attr->ia_ctime; | |
355 | if (ia_valid & ATTR_MODE) { | |
356 | ADFS_I(inode)->attr = adfs_mode2atts(sb, inode); | |
357 | inode->i_mode = adfs_atts2mode(sb, inode); | |
358 | } | |
359 | ||
360 | /* | |
361 | * FIXME: should we be marking this inode dirty even if | |
362 | * we don't have any metadata to write back? | |
363 | */ | |
364 | if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE)) | |
365 | mark_inode_dirty(inode); | |
366 | out: | |
367 | unlock_kernel(); | |
368 | return error; | |
369 | } | |
370 | ||
371 | /* | |
372 | * write an existing inode back to the directory, and therefore the disk. | |
373 | * The adfs-specific inode data has already been updated by | |
374 | * adfs_notify_change() | |
375 | */ | |
376 | int adfs_write_inode(struct inode *inode, int unused) | |
377 | { | |
378 | struct super_block *sb = inode->i_sb; | |
379 | struct object_info obj; | |
380 | int ret; | |
381 | ||
382 | lock_kernel(); | |
383 | obj.file_id = inode->i_ino; | |
384 | obj.name_len = 0; | |
385 | obj.parent_id = ADFS_I(inode)->parent_id; | |
386 | obj.loadaddr = ADFS_I(inode)->loadaddr; | |
387 | obj.execaddr = ADFS_I(inode)->execaddr; | |
388 | obj.attr = ADFS_I(inode)->attr; | |
389 | obj.size = inode->i_size; | |
390 | ||
391 | ret = adfs_dir_update(sb, &obj); | |
392 | unlock_kernel(); | |
393 | return ret; | |
394 | } | |
395 | MODULE_LICENSE("GPL"); |