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Commit | Line | Data |
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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 | */ | |
1da177e4 | 10 | #include <linux/smp_lock.h> |
1da177e4 | 11 | #include <linux/buffer_head.h> |
1da177e4 LT |
12 | #include "adfs.h" |
13 | ||
14 | /* | |
15 | * Lookup/Create a block at offset 'block' into 'inode'. We currently do | |
16 | * not support creation of new blocks, so we return -EIO for this case. | |
17 | */ | |
18 | static int | |
19 | adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh, | |
20 | int create) | |
21 | { | |
1da177e4 LT |
22 | if (!create) { |
23 | if (block >= inode->i_blocks) | |
24 | goto abort_toobig; | |
25 | ||
26 | block = __adfs_block_map(inode->i_sb, inode->i_ino, block); | |
27 | if (block) | |
28 | map_bh(bh, inode->i_sb, block); | |
29 | return 0; | |
30 | } | |
31 | /* don't support allocation of blocks yet */ | |
32 | return -EIO; | |
33 | ||
1da177e4 LT |
34 | abort_toobig: |
35 | return 0; | |
36 | } | |
37 | ||
38 | static int adfs_writepage(struct page *page, struct writeback_control *wbc) | |
39 | { | |
40 | return block_write_full_page(page, adfs_get_block, wbc); | |
41 | } | |
42 | ||
43 | static int adfs_readpage(struct file *file, struct page *page) | |
44 | { | |
45 | return block_read_full_page(page, adfs_get_block); | |
46 | } | |
47 | ||
b4585729 NP |
48 | static int adfs_write_begin(struct file *file, struct address_space *mapping, |
49 | loff_t pos, unsigned len, unsigned flags, | |
50 | struct page **pagep, void **fsdata) | |
1da177e4 | 51 | { |
b4585729 NP |
52 | *pagep = NULL; |
53 | return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, | |
54 | adfs_get_block, | |
55 | &ADFS_I(mapping->host)->mmu_private); | |
1da177e4 LT |
56 | } |
57 | ||
58 | static sector_t _adfs_bmap(struct address_space *mapping, sector_t block) | |
59 | { | |
60 | return generic_block_bmap(mapping, block, adfs_get_block); | |
61 | } | |
62 | ||
f5e54d6e | 63 | static const struct address_space_operations adfs_aops = { |
1da177e4 LT |
64 | .readpage = adfs_readpage, |
65 | .writepage = adfs_writepage, | |
66 | .sync_page = block_sync_page, | |
b4585729 NP |
67 | .write_begin = adfs_write_begin, |
68 | .write_end = generic_write_end, | |
1da177e4 LT |
69 | .bmap = _adfs_bmap |
70 | }; | |
71 | ||
72 | static inline unsigned int | |
73 | adfs_filetype(struct inode *inode) | |
74 | { | |
75 | unsigned int type; | |
76 | ||
77 | if (ADFS_I(inode)->stamped) | |
78 | type = (ADFS_I(inode)->loadaddr >> 8) & 0xfff; | |
79 | else | |
80 | type = (unsigned int) -1; | |
81 | ||
82 | return type; | |
83 | } | |
84 | ||
85 | /* | |
86 | * Convert ADFS attributes and filetype to Linux permission. | |
87 | */ | |
88 | static umode_t | |
89 | adfs_atts2mode(struct super_block *sb, struct inode *inode) | |
90 | { | |
91 | unsigned int filetype, attr = ADFS_I(inode)->attr; | |
92 | umode_t mode, rmask; | |
93 | struct adfs_sb_info *asb = ADFS_SB(sb); | |
94 | ||
95 | if (attr & ADFS_NDA_DIRECTORY) { | |
96 | mode = S_IRUGO & asb->s_owner_mask; | |
97 | return S_IFDIR | S_IXUGO | mode; | |
98 | } | |
99 | ||
100 | filetype = adfs_filetype(inode); | |
101 | ||
102 | switch (filetype) { | |
103 | case 0xfc0: /* LinkFS */ | |
104 | return S_IFLNK|S_IRWXUGO; | |
105 | ||
106 | case 0xfe6: /* UnixExec */ | |
107 | rmask = S_IRUGO | S_IXUGO; | |
108 | break; | |
109 | ||
110 | default: | |
111 | rmask = S_IRUGO; | |
112 | } | |
113 | ||
114 | mode = S_IFREG; | |
115 | ||
116 | if (attr & ADFS_NDA_OWNER_READ) | |
117 | mode |= rmask & asb->s_owner_mask; | |
118 | ||
119 | if (attr & ADFS_NDA_OWNER_WRITE) | |
120 | mode |= S_IWUGO & asb->s_owner_mask; | |
121 | ||
122 | if (attr & ADFS_NDA_PUBLIC_READ) | |
123 | mode |= rmask & asb->s_other_mask; | |
124 | ||
125 | if (attr & ADFS_NDA_PUBLIC_WRITE) | |
126 | mode |= S_IWUGO & asb->s_other_mask; | |
127 | return mode; | |
128 | } | |
129 | ||
130 | /* | |
131 | * Convert Linux permission to ADFS attribute. We try to do the reverse | |
132 | * of atts2mode, but there is not a 1:1 translation. | |
133 | */ | |
134 | static int | |
135 | adfs_mode2atts(struct super_block *sb, struct inode *inode) | |
136 | { | |
137 | umode_t mode; | |
138 | int attr; | |
139 | struct adfs_sb_info *asb = ADFS_SB(sb); | |
140 | ||
141 | /* FIXME: should we be able to alter a link? */ | |
142 | if (S_ISLNK(inode->i_mode)) | |
143 | return ADFS_I(inode)->attr; | |
144 | ||
145 | if (S_ISDIR(inode->i_mode)) | |
146 | attr = ADFS_NDA_DIRECTORY; | |
147 | else | |
148 | attr = 0; | |
149 | ||
150 | mode = inode->i_mode & asb->s_owner_mask; | |
151 | if (mode & S_IRUGO) | |
152 | attr |= ADFS_NDA_OWNER_READ; | |
153 | if (mode & S_IWUGO) | |
154 | attr |= ADFS_NDA_OWNER_WRITE; | |
155 | ||
156 | mode = inode->i_mode & asb->s_other_mask; | |
157 | mode &= ~asb->s_owner_mask; | |
158 | if (mode & S_IRUGO) | |
159 | attr |= ADFS_NDA_PUBLIC_READ; | |
160 | if (mode & S_IWUGO) | |
161 | attr |= ADFS_NDA_PUBLIC_WRITE; | |
162 | ||
163 | return attr; | |
164 | } | |
165 | ||
166 | /* | |
167 | * Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time | |
168 | * referenced to 1 Jan 1900 (til 2248) | |
169 | */ | |
170 | static void | |
171 | adfs_adfs2unix_time(struct timespec *tv, struct inode *inode) | |
172 | { | |
173 | unsigned int high, low; | |
174 | ||
175 | if (ADFS_I(inode)->stamped == 0) | |
176 | goto cur_time; | |
177 | ||
178 | high = ADFS_I(inode)->loadaddr << 24; | |
179 | low = ADFS_I(inode)->execaddr; | |
180 | ||
181 | high |= low >> 8; | |
182 | low &= 255; | |
183 | ||
184 | /* Files dated pre 01 Jan 1970 00:00:00. */ | |
185 | if (high < 0x336e996a) | |
186 | goto too_early; | |
187 | ||
188 | /* Files dated post 18 Jan 2038 03:14:05. */ | |
189 | if (high >= 0x656e9969) | |
190 | goto too_late; | |
191 | ||
192 | /* discard 2208988800 (0x336e996a00) seconds of time */ | |
193 | high -= 0x336e996a; | |
194 | ||
195 | /* convert 40-bit centi-seconds to 32-bit seconds */ | |
196 | tv->tv_sec = (((high % 100) << 8) + low) / 100 + (high / 100 << 8); | |
197 | tv->tv_nsec = 0; | |
198 | return; | |
199 | ||
200 | cur_time: | |
201 | *tv = CURRENT_TIME_SEC; | |
202 | return; | |
203 | ||
204 | too_early: | |
205 | tv->tv_sec = tv->tv_nsec = 0; | |
206 | return; | |
207 | ||
208 | too_late: | |
209 | tv->tv_sec = 0x7ffffffd; | |
210 | tv->tv_nsec = 0; | |
211 | return; | |
212 | } | |
213 | ||
214 | /* | |
215 | * Convert an Unix time to ADFS time. We only do this if the entry has a | |
216 | * time/date stamp already. | |
217 | */ | |
218 | static void | |
219 | adfs_unix2adfs_time(struct inode *inode, unsigned int secs) | |
220 | { | |
221 | unsigned int high, low; | |
222 | ||
223 | if (ADFS_I(inode)->stamped) { | |
224 | /* convert 32-bit seconds to 40-bit centi-seconds */ | |
225 | low = (secs & 255) * 100; | |
226 | high = (secs / 256) * 100 + (low >> 8) + 0x336e996a; | |
227 | ||
228 | ADFS_I(inode)->loadaddr = (high >> 24) | | |
229 | (ADFS_I(inode)->loadaddr & ~0xff); | |
230 | ADFS_I(inode)->execaddr = (low & 255) | (high << 8); | |
231 | } | |
232 | } | |
233 | ||
234 | /* | |
235 | * Fill in the inode information from the object information. | |
236 | * | |
237 | * Note that this is an inode-less filesystem, so we can't use the inode | |
238 | * number to reference the metadata on the media. Instead, we use the | |
239 | * inode number to hold the object ID, which in turn will tell us where | |
240 | * the data is held. We also save the parent object ID, and with these | |
241 | * two, we can locate the metadata. | |
242 | * | |
243 | * This does mean that we rely on an objects parent remaining the same at | |
244 | * all times - we cannot cope with a cross-directory rename (yet). | |
245 | */ | |
246 | struct inode * | |
247 | adfs_iget(struct super_block *sb, struct object_info *obj) | |
248 | { | |
249 | struct inode *inode; | |
250 | ||
251 | inode = new_inode(sb); | |
252 | if (!inode) | |
253 | goto out; | |
254 | ||
255 | inode->i_uid = ADFS_SB(sb)->s_uid; | |
256 | inode->i_gid = ADFS_SB(sb)->s_gid; | |
257 | inode->i_ino = obj->file_id; | |
258 | inode->i_size = obj->size; | |
259 | inode->i_nlink = 2; | |
1da177e4 LT |
260 | inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >> |
261 | sb->s_blocksize_bits; | |
262 | ||
263 | /* | |
264 | * we need to save the parent directory ID so that | |
265 | * write_inode can update the directory information | |
266 | * for this file. This will need special handling | |
267 | * for cross-directory renames. | |
268 | */ | |
269 | ADFS_I(inode)->parent_id = obj->parent_id; | |
270 | ADFS_I(inode)->loadaddr = obj->loadaddr; | |
271 | ADFS_I(inode)->execaddr = obj->execaddr; | |
272 | ADFS_I(inode)->attr = obj->attr; | |
273 | ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000); | |
274 | ||
275 | inode->i_mode = adfs_atts2mode(sb, inode); | |
276 | adfs_adfs2unix_time(&inode->i_mtime, inode); | |
277 | inode->i_atime = inode->i_mtime; | |
278 | inode->i_ctime = inode->i_mtime; | |
279 | ||
280 | if (S_ISDIR(inode->i_mode)) { | |
281 | inode->i_op = &adfs_dir_inode_operations; | |
282 | inode->i_fop = &adfs_dir_operations; | |
283 | } else if (S_ISREG(inode->i_mode)) { | |
284 | inode->i_op = &adfs_file_inode_operations; | |
285 | inode->i_fop = &adfs_file_operations; | |
286 | inode->i_mapping->a_ops = &adfs_aops; | |
287 | ADFS_I(inode)->mmu_private = inode->i_size; | |
288 | } | |
289 | ||
290 | insert_inode_hash(inode); | |
291 | ||
292 | out: | |
293 | return inode; | |
294 | } | |
295 | ||
296 | /* | |
297 | * Validate and convert a changed access mode/time to their ADFS equivalents. | |
298 | * adfs_write_inode will actually write the information back to the directory | |
299 | * later. | |
300 | */ | |
301 | int | |
302 | adfs_notify_change(struct dentry *dentry, struct iattr *attr) | |
303 | { | |
304 | struct inode *inode = dentry->d_inode; | |
305 | struct super_block *sb = inode->i_sb; | |
306 | unsigned int ia_valid = attr->ia_valid; | |
307 | int error; | |
308 | ||
309 | lock_kernel(); | |
310 | ||
311 | error = inode_change_ok(inode, attr); | |
312 | ||
313 | /* | |
314 | * we can't change the UID or GID of any file - | |
315 | * we have a global UID/GID in the superblock | |
316 | */ | |
317 | if ((ia_valid & ATTR_UID && attr->ia_uid != ADFS_SB(sb)->s_uid) || | |
318 | (ia_valid & ATTR_GID && attr->ia_gid != ADFS_SB(sb)->s_gid)) | |
319 | error = -EPERM; | |
320 | ||
321 | if (error) | |
322 | goto out; | |
323 | ||
324 | if (ia_valid & ATTR_SIZE) | |
325 | error = vmtruncate(inode, attr->ia_size); | |
326 | ||
327 | if (error) | |
328 | goto out; | |
329 | ||
330 | if (ia_valid & ATTR_MTIME) { | |
331 | inode->i_mtime = attr->ia_mtime; | |
332 | adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec); | |
333 | } | |
334 | /* | |
335 | * FIXME: should we make these == to i_mtime since we don't | |
336 | * have the ability to represent them in our filesystem? | |
337 | */ | |
338 | if (ia_valid & ATTR_ATIME) | |
339 | inode->i_atime = attr->ia_atime; | |
340 | if (ia_valid & ATTR_CTIME) | |
341 | inode->i_ctime = attr->ia_ctime; | |
342 | if (ia_valid & ATTR_MODE) { | |
343 | ADFS_I(inode)->attr = adfs_mode2atts(sb, inode); | |
344 | inode->i_mode = adfs_atts2mode(sb, inode); | |
345 | } | |
346 | ||
347 | /* | |
348 | * FIXME: should we be marking this inode dirty even if | |
349 | * we don't have any metadata to write back? | |
350 | */ | |
351 | if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE)) | |
352 | mark_inode_dirty(inode); | |
353 | out: | |
354 | unlock_kernel(); | |
355 | return error; | |
356 | } | |
357 | ||
358 | /* | |
359 | * write an existing inode back to the directory, and therefore the disk. | |
360 | * The adfs-specific inode data has already been updated by | |
361 | * adfs_notify_change() | |
362 | */ | |
ffdc9064 | 363 | int adfs_write_inode(struct inode *inode, int wait) |
1da177e4 LT |
364 | { |
365 | struct super_block *sb = inode->i_sb; | |
366 | struct object_info obj; | |
367 | int ret; | |
368 | ||
369 | lock_kernel(); | |
370 | obj.file_id = inode->i_ino; | |
371 | obj.name_len = 0; | |
372 | obj.parent_id = ADFS_I(inode)->parent_id; | |
373 | obj.loadaddr = ADFS_I(inode)->loadaddr; | |
374 | obj.execaddr = ADFS_I(inode)->execaddr; | |
375 | obj.attr = ADFS_I(inode)->attr; | |
376 | obj.size = inode->i_size; | |
377 | ||
ffdc9064 | 378 | ret = adfs_dir_update(sb, &obj, wait); |
1da177e4 LT |
379 | unlock_kernel(); |
380 | return ret; | |
381 | } |