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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/smp_lock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/buffer_head.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#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 */
18static int
19adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh,
20 int create)
21{
22 if (block < 0)
23 goto abort_negative;
24
25 if (!create) {
26 if (block >= inode->i_blocks)
27 goto abort_toobig;
28
29 block = __adfs_block_map(inode->i_sb, inode->i_ino, block);
30 if (block)
31 map_bh(bh, inode->i_sb, block);
32 return 0;
33 }
34 /* don't support allocation of blocks yet */
35 return -EIO;
36
37abort_negative:
38 adfs_error(inode->i_sb, "block %d < 0", block);
39 return -EIO;
40
41abort_toobig:
42 return 0;
43}
44
45static int adfs_writepage(struct page *page, struct writeback_control *wbc)
46{
47 return block_write_full_page(page, adfs_get_block, wbc);
48}
49
50static int adfs_readpage(struct file *file, struct page *page)
51{
52 return block_read_full_page(page, adfs_get_block);
53}
54
Nick Pigginb4585722007-10-16 01:25:23 -070055static int adfs_write_begin(struct file *file, struct address_space *mapping,
56 loff_t pos, unsigned len, unsigned flags,
57 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058{
Nick Pigginb4585722007-10-16 01:25:23 -070059 *pagep = NULL;
60 return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
61 adfs_get_block,
62 &ADFS_I(mapping->host)->mmu_private);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063}
64
65static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
66{
67 return generic_block_bmap(mapping, block, adfs_get_block);
68}
69
Christoph Hellwigf5e54d62006-06-28 04:26:44 -070070static const struct address_space_operations adfs_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 .readpage = adfs_readpage,
72 .writepage = adfs_writepage,
73 .sync_page = block_sync_page,
Nick Pigginb4585722007-10-16 01:25:23 -070074 .write_begin = adfs_write_begin,
75 .write_end = generic_write_end,
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 .bmap = _adfs_bmap
77};
78
79static inline unsigned int
80adfs_filetype(struct inode *inode)
81{
82 unsigned int type;
83
84 if (ADFS_I(inode)->stamped)
85 type = (ADFS_I(inode)->loadaddr >> 8) & 0xfff;
86 else
87 type = (unsigned int) -1;
88
89 return type;
90}
91
92/*
93 * Convert ADFS attributes and filetype to Linux permission.
94 */
95static umode_t
96adfs_atts2mode(struct super_block *sb, struct inode *inode)
97{
98 unsigned int filetype, attr = ADFS_I(inode)->attr;
99 umode_t mode, rmask;
100 struct adfs_sb_info *asb = ADFS_SB(sb);
101
102 if (attr & ADFS_NDA_DIRECTORY) {
103 mode = S_IRUGO & asb->s_owner_mask;
104 return S_IFDIR | S_IXUGO | mode;
105 }
106
107 filetype = adfs_filetype(inode);
108
109 switch (filetype) {
110 case 0xfc0: /* LinkFS */
111 return S_IFLNK|S_IRWXUGO;
112
113 case 0xfe6: /* UnixExec */
114 rmask = S_IRUGO | S_IXUGO;
115 break;
116
117 default:
118 rmask = S_IRUGO;
119 }
120
121 mode = S_IFREG;
122
123 if (attr & ADFS_NDA_OWNER_READ)
124 mode |= rmask & asb->s_owner_mask;
125
126 if (attr & ADFS_NDA_OWNER_WRITE)
127 mode |= S_IWUGO & asb->s_owner_mask;
128
129 if (attr & ADFS_NDA_PUBLIC_READ)
130 mode |= rmask & asb->s_other_mask;
131
132 if (attr & ADFS_NDA_PUBLIC_WRITE)
133 mode |= S_IWUGO & asb->s_other_mask;
134 return mode;
135}
136
137/*
138 * Convert Linux permission to ADFS attribute. We try to do the reverse
139 * of atts2mode, but there is not a 1:1 translation.
140 */
141static int
142adfs_mode2atts(struct super_block *sb, struct inode *inode)
143{
144 umode_t mode;
145 int attr;
146 struct adfs_sb_info *asb = ADFS_SB(sb);
147
148 /* FIXME: should we be able to alter a link? */
149 if (S_ISLNK(inode->i_mode))
150 return ADFS_I(inode)->attr;
151
152 if (S_ISDIR(inode->i_mode))
153 attr = ADFS_NDA_DIRECTORY;
154 else
155 attr = 0;
156
157 mode = inode->i_mode & asb->s_owner_mask;
158 if (mode & S_IRUGO)
159 attr |= ADFS_NDA_OWNER_READ;
160 if (mode & S_IWUGO)
161 attr |= ADFS_NDA_OWNER_WRITE;
162
163 mode = inode->i_mode & asb->s_other_mask;
164 mode &= ~asb->s_owner_mask;
165 if (mode & S_IRUGO)
166 attr |= ADFS_NDA_PUBLIC_READ;
167 if (mode & S_IWUGO)
168 attr |= ADFS_NDA_PUBLIC_WRITE;
169
170 return attr;
171}
172
173/*
174 * Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time
175 * referenced to 1 Jan 1900 (til 2248)
176 */
177static void
178adfs_adfs2unix_time(struct timespec *tv, struct inode *inode)
179{
180 unsigned int high, low;
181
182 if (ADFS_I(inode)->stamped == 0)
183 goto cur_time;
184
185 high = ADFS_I(inode)->loadaddr << 24;
186 low = ADFS_I(inode)->execaddr;
187
188 high |= low >> 8;
189 low &= 255;
190
191 /* Files dated pre 01 Jan 1970 00:00:00. */
192 if (high < 0x336e996a)
193 goto too_early;
194
195 /* Files dated post 18 Jan 2038 03:14:05. */
196 if (high >= 0x656e9969)
197 goto too_late;
198
199 /* discard 2208988800 (0x336e996a00) seconds of time */
200 high -= 0x336e996a;
201
202 /* convert 40-bit centi-seconds to 32-bit seconds */
203 tv->tv_sec = (((high % 100) << 8) + low) / 100 + (high / 100 << 8);
204 tv->tv_nsec = 0;
205 return;
206
207 cur_time:
208 *tv = CURRENT_TIME_SEC;
209 return;
210
211 too_early:
212 tv->tv_sec = tv->tv_nsec = 0;
213 return;
214
215 too_late:
216 tv->tv_sec = 0x7ffffffd;
217 tv->tv_nsec = 0;
218 return;
219}
220
221/*
222 * Convert an Unix time to ADFS time. We only do this if the entry has a
223 * time/date stamp already.
224 */
225static void
226adfs_unix2adfs_time(struct inode *inode, unsigned int secs)
227{
228 unsigned int high, low;
229
230 if (ADFS_I(inode)->stamped) {
231 /* convert 32-bit seconds to 40-bit centi-seconds */
232 low = (secs & 255) * 100;
233 high = (secs / 256) * 100 + (low >> 8) + 0x336e996a;
234
235 ADFS_I(inode)->loadaddr = (high >> 24) |
236 (ADFS_I(inode)->loadaddr & ~0xff);
237 ADFS_I(inode)->execaddr = (low & 255) | (high << 8);
238 }
239}
240
241/*
242 * Fill in the inode information from the object information.
243 *
244 * Note that this is an inode-less filesystem, so we can't use the inode
245 * number to reference the metadata on the media. Instead, we use the
246 * inode number to hold the object ID, which in turn will tell us where
247 * the data is held. We also save the parent object ID, and with these
248 * two, we can locate the metadata.
249 *
250 * This does mean that we rely on an objects parent remaining the same at
251 * all times - we cannot cope with a cross-directory rename (yet).
252 */
253struct inode *
254adfs_iget(struct super_block *sb, struct object_info *obj)
255{
256 struct inode *inode;
257
258 inode = new_inode(sb);
259 if (!inode)
260 goto out;
261
262 inode->i_uid = ADFS_SB(sb)->s_uid;
263 inode->i_gid = ADFS_SB(sb)->s_gid;
264 inode->i_ino = obj->file_id;
265 inode->i_size = obj->size;
266 inode->i_nlink = 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >>
268 sb->s_blocksize_bits;
269
270 /*
271 * we need to save the parent directory ID so that
272 * write_inode can update the directory information
273 * for this file. This will need special handling
274 * for cross-directory renames.
275 */
276 ADFS_I(inode)->parent_id = obj->parent_id;
277 ADFS_I(inode)->loadaddr = obj->loadaddr;
278 ADFS_I(inode)->execaddr = obj->execaddr;
279 ADFS_I(inode)->attr = obj->attr;
280 ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000);
281
282 inode->i_mode = adfs_atts2mode(sb, inode);
283 adfs_adfs2unix_time(&inode->i_mtime, inode);
284 inode->i_atime = inode->i_mtime;
285 inode->i_ctime = inode->i_mtime;
286
287 if (S_ISDIR(inode->i_mode)) {
288 inode->i_op = &adfs_dir_inode_operations;
289 inode->i_fop = &adfs_dir_operations;
290 } else if (S_ISREG(inode->i_mode)) {
291 inode->i_op = &adfs_file_inode_operations;
292 inode->i_fop = &adfs_file_operations;
293 inode->i_mapping->a_ops = &adfs_aops;
294 ADFS_I(inode)->mmu_private = inode->i_size;
295 }
296
297 insert_inode_hash(inode);
298
299out:
300 return inode;
301}
302
303/*
304 * Validate and convert a changed access mode/time to their ADFS equivalents.
305 * adfs_write_inode will actually write the information back to the directory
306 * later.
307 */
308int
309adfs_notify_change(struct dentry *dentry, struct iattr *attr)
310{
311 struct inode *inode = dentry->d_inode;
312 struct super_block *sb = inode->i_sb;
313 unsigned int ia_valid = attr->ia_valid;
314 int error;
315
316 lock_kernel();
317
318 error = inode_change_ok(inode, attr);
319
320 /*
321 * we can't change the UID or GID of any file -
322 * we have a global UID/GID in the superblock
323 */
324 if ((ia_valid & ATTR_UID && attr->ia_uid != ADFS_SB(sb)->s_uid) ||
325 (ia_valid & ATTR_GID && attr->ia_gid != ADFS_SB(sb)->s_gid))
326 error = -EPERM;
327
328 if (error)
329 goto out;
330
331 if (ia_valid & ATTR_SIZE)
332 error = vmtruncate(inode, attr->ia_size);
333
334 if (error)
335 goto out;
336
337 if (ia_valid & ATTR_MTIME) {
338 inode->i_mtime = attr->ia_mtime;
339 adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec);
340 }
341 /*
342 * FIXME: should we make these == to i_mtime since we don't
343 * have the ability to represent them in our filesystem?
344 */
345 if (ia_valid & ATTR_ATIME)
346 inode->i_atime = attr->ia_atime;
347 if (ia_valid & ATTR_CTIME)
348 inode->i_ctime = attr->ia_ctime;
349 if (ia_valid & ATTR_MODE) {
350 ADFS_I(inode)->attr = adfs_mode2atts(sb, inode);
351 inode->i_mode = adfs_atts2mode(sb, inode);
352 }
353
354 /*
355 * FIXME: should we be marking this inode dirty even if
356 * we don't have any metadata to write back?
357 */
358 if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE))
359 mark_inode_dirty(inode);
360out:
361 unlock_kernel();
362 return error;
363}
364
365/*
366 * write an existing inode back to the directory, and therefore the disk.
367 * The adfs-specific inode data has already been updated by
368 * adfs_notify_change()
369 */
Al Viroffdc9062009-06-08 00:44:42 -0400370int adfs_write_inode(struct inode *inode, int wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371{
372 struct super_block *sb = inode->i_sb;
373 struct object_info obj;
374 int ret;
375
376 lock_kernel();
377 obj.file_id = inode->i_ino;
378 obj.name_len = 0;
379 obj.parent_id = ADFS_I(inode)->parent_id;
380 obj.loadaddr = ADFS_I(inode)->loadaddr;
381 obj.execaddr = ADFS_I(inode)->execaddr;
382 obj.attr = ADFS_I(inode)->attr;
383 obj.size = inode->i_size;
384
Al Viroffdc9062009-06-08 00:44:42 -0400385 ret = adfs_dir_update(sb, &obj, wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 unlock_kernel();
387 return ret;
388}