blob: 65794b8fe79ebe81d760bd1da6a4e8b5dd461680 [file] [log] [blame]
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>
Christoph Hellwiga9185b42010-03-05 09:21:37 +010012#include <linux/writeback.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include "adfs.h"
14
15/*
16 * Lookup/Create a block at offset 'block' into 'inode'. We currently do
17 * not support creation of new blocks, so we return -EIO for this case.
18 */
19static int
20adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh,
21 int create)
22{
Linus Torvalds1da177e2005-04-16 15:20:36 -070023 if (!create) {
24 if (block >= inode->i_blocks)
25 goto abort_toobig;
26
27 block = __adfs_block_map(inode->i_sb, inode->i_ino, block);
28 if (block)
29 map_bh(bh, inode->i_sb, block);
30 return 0;
31 }
32 /* don't support allocation of blocks yet */
33 return -EIO;
34
Linus Torvalds1da177e2005-04-16 15:20:36 -070035abort_toobig:
36 return 0;
37}
38
39static int adfs_writepage(struct page *page, struct writeback_control *wbc)
40{
41 return block_write_full_page(page, adfs_get_block, wbc);
42}
43
44static int adfs_readpage(struct file *file, struct page *page)
45{
46 return block_read_full_page(page, adfs_get_block);
47}
48
Nick Pigginb4585722007-10-16 01:25:23 -070049static int adfs_write_begin(struct file *file, struct address_space *mapping,
50 loff_t pos, unsigned len, unsigned flags,
51 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -070052{
Christoph Hellwig282dc172010-06-04 11:29:55 +020053 int ret;
54
Nick Pigginb4585722007-10-16 01:25:23 -070055 *pagep = NULL;
Christoph Hellwig282dc172010-06-04 11:29:55 +020056 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
Nick Pigginb4585722007-10-16 01:25:23 -070057 adfs_get_block,
58 &ADFS_I(mapping->host)->mmu_private);
Christoph Hellwig282dc172010-06-04 11:29:55 +020059 if (unlikely(ret)) {
60 loff_t isize = mapping->host->i_size;
61 if (pos + len > isize)
62 vmtruncate(mapping->host, isize);
63 }
64
65 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066}
67
68static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
69{
70 return generic_block_bmap(mapping, block, adfs_get_block);
71}
72
Christoph Hellwigf5e54d62006-06-28 04:26:44 -070073static const struct address_space_operations adfs_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 .readpage = adfs_readpage,
75 .writepage = adfs_writepage,
76 .sync_page = block_sync_page,
Nick Pigginb4585722007-10-16 01:25:23 -070077 .write_begin = adfs_write_begin,
78 .write_end = generic_write_end,
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 .bmap = _adfs_bmap
80};
81
82static inline unsigned int
83adfs_filetype(struct inode *inode)
84{
85 unsigned int type;
86
87 if (ADFS_I(inode)->stamped)
88 type = (ADFS_I(inode)->loadaddr >> 8) & 0xfff;
89 else
90 type = (unsigned int) -1;
91
92 return type;
93}
94
95/*
96 * Convert ADFS attributes and filetype to Linux permission.
97 */
98static umode_t
99adfs_atts2mode(struct super_block *sb, struct inode *inode)
100{
101 unsigned int filetype, attr = ADFS_I(inode)->attr;
102 umode_t mode, rmask;
103 struct adfs_sb_info *asb = ADFS_SB(sb);
104
105 if (attr & ADFS_NDA_DIRECTORY) {
106 mode = S_IRUGO & asb->s_owner_mask;
107 return S_IFDIR | S_IXUGO | mode;
108 }
109
110 filetype = adfs_filetype(inode);
111
112 switch (filetype) {
113 case 0xfc0: /* LinkFS */
114 return S_IFLNK|S_IRWXUGO;
115
116 case 0xfe6: /* UnixExec */
117 rmask = S_IRUGO | S_IXUGO;
118 break;
119
120 default:
121 rmask = S_IRUGO;
122 }
123
124 mode = S_IFREG;
125
126 if (attr & ADFS_NDA_OWNER_READ)
127 mode |= rmask & asb->s_owner_mask;
128
129 if (attr & ADFS_NDA_OWNER_WRITE)
130 mode |= S_IWUGO & asb->s_owner_mask;
131
132 if (attr & ADFS_NDA_PUBLIC_READ)
133 mode |= rmask & asb->s_other_mask;
134
135 if (attr & ADFS_NDA_PUBLIC_WRITE)
136 mode |= S_IWUGO & asb->s_other_mask;
137 return mode;
138}
139
140/*
141 * Convert Linux permission to ADFS attribute. We try to do the reverse
142 * of atts2mode, but there is not a 1:1 translation.
143 */
144static int
145adfs_mode2atts(struct super_block *sb, struct inode *inode)
146{
147 umode_t mode;
148 int attr;
149 struct adfs_sb_info *asb = ADFS_SB(sb);
150
151 /* FIXME: should we be able to alter a link? */
152 if (S_ISLNK(inode->i_mode))
153 return ADFS_I(inode)->attr;
154
155 if (S_ISDIR(inode->i_mode))
156 attr = ADFS_NDA_DIRECTORY;
157 else
158 attr = 0;
159
160 mode = inode->i_mode & asb->s_owner_mask;
161 if (mode & S_IRUGO)
162 attr |= ADFS_NDA_OWNER_READ;
163 if (mode & S_IWUGO)
164 attr |= ADFS_NDA_OWNER_WRITE;
165
166 mode = inode->i_mode & asb->s_other_mask;
167 mode &= ~asb->s_owner_mask;
168 if (mode & S_IRUGO)
169 attr |= ADFS_NDA_PUBLIC_READ;
170 if (mode & S_IWUGO)
171 attr |= ADFS_NDA_PUBLIC_WRITE;
172
173 return attr;
174}
175
176/*
177 * Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time
178 * referenced to 1 Jan 1900 (til 2248)
179 */
180static void
181adfs_adfs2unix_time(struct timespec *tv, struct inode *inode)
182{
183 unsigned int high, low;
184
185 if (ADFS_I(inode)->stamped == 0)
186 goto cur_time;
187
188 high = ADFS_I(inode)->loadaddr << 24;
189 low = ADFS_I(inode)->execaddr;
190
191 high |= low >> 8;
192 low &= 255;
193
194 /* Files dated pre 01 Jan 1970 00:00:00. */
195 if (high < 0x336e996a)
196 goto too_early;
197
198 /* Files dated post 18 Jan 2038 03:14:05. */
199 if (high >= 0x656e9969)
200 goto too_late;
201
202 /* discard 2208988800 (0x336e996a00) seconds of time */
203 high -= 0x336e996a;
204
205 /* convert 40-bit centi-seconds to 32-bit seconds */
206 tv->tv_sec = (((high % 100) << 8) + low) / 100 + (high / 100 << 8);
207 tv->tv_nsec = 0;
208 return;
209
210 cur_time:
211 *tv = CURRENT_TIME_SEC;
212 return;
213
214 too_early:
215 tv->tv_sec = tv->tv_nsec = 0;
216 return;
217
218 too_late:
219 tv->tv_sec = 0x7ffffffd;
220 tv->tv_nsec = 0;
221 return;
222}
223
224/*
225 * Convert an Unix time to ADFS time. We only do this if the entry has a
226 * time/date stamp already.
227 */
228static void
229adfs_unix2adfs_time(struct inode *inode, unsigned int secs)
230{
231 unsigned int high, low;
232
233 if (ADFS_I(inode)->stamped) {
234 /* convert 32-bit seconds to 40-bit centi-seconds */
235 low = (secs & 255) * 100;
236 high = (secs / 256) * 100 + (low >> 8) + 0x336e996a;
237
238 ADFS_I(inode)->loadaddr = (high >> 24) |
239 (ADFS_I(inode)->loadaddr & ~0xff);
240 ADFS_I(inode)->execaddr = (low & 255) | (high << 8);
241 }
242}
243
244/*
245 * Fill in the inode information from the object information.
246 *
247 * Note that this is an inode-less filesystem, so we can't use the inode
248 * number to reference the metadata on the media. Instead, we use the
249 * inode number to hold the object ID, which in turn will tell us where
250 * the data is held. We also save the parent object ID, and with these
251 * two, we can locate the metadata.
252 *
253 * This does mean that we rely on an objects parent remaining the same at
254 * all times - we cannot cope with a cross-directory rename (yet).
255 */
256struct inode *
257adfs_iget(struct super_block *sb, struct object_info *obj)
258{
259 struct inode *inode;
260
261 inode = new_inode(sb);
262 if (!inode)
263 goto out;
264
265 inode->i_uid = ADFS_SB(sb)->s_uid;
266 inode->i_gid = ADFS_SB(sb)->s_gid;
267 inode->i_ino = obj->file_id;
268 inode->i_size = obj->size;
269 inode->i_nlink = 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >>
271 sb->s_blocksize_bits;
272
273 /*
274 * we need to save the parent directory ID so that
275 * write_inode can update the directory information
276 * for this file. This will need special handling
277 * for cross-directory renames.
278 */
279 ADFS_I(inode)->parent_id = obj->parent_id;
280 ADFS_I(inode)->loadaddr = obj->loadaddr;
281 ADFS_I(inode)->execaddr = obj->execaddr;
282 ADFS_I(inode)->attr = obj->attr;
283 ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000);
284
285 inode->i_mode = adfs_atts2mode(sb, inode);
286 adfs_adfs2unix_time(&inode->i_mtime, inode);
287 inode->i_atime = inode->i_mtime;
288 inode->i_ctime = inode->i_mtime;
289
290 if (S_ISDIR(inode->i_mode)) {
291 inode->i_op = &adfs_dir_inode_operations;
292 inode->i_fop = &adfs_dir_operations;
293 } else if (S_ISREG(inode->i_mode)) {
294 inode->i_op = &adfs_file_inode_operations;
295 inode->i_fop = &adfs_file_operations;
296 inode->i_mapping->a_ops = &adfs_aops;
297 ADFS_I(inode)->mmu_private = inode->i_size;
298 }
299
300 insert_inode_hash(inode);
301
302out:
303 return inode;
304}
305
306/*
307 * Validate and convert a changed access mode/time to their ADFS equivalents.
308 * adfs_write_inode will actually write the information back to the directory
309 * later.
310 */
311int
312adfs_notify_change(struct dentry *dentry, struct iattr *attr)
313{
314 struct inode *inode = dentry->d_inode;
315 struct super_block *sb = inode->i_sb;
316 unsigned int ia_valid = attr->ia_valid;
317 int error;
318
319 lock_kernel();
320
321 error = inode_change_ok(inode, attr);
322
323 /*
324 * we can't change the UID or GID of any file -
325 * we have a global UID/GID in the superblock
326 */
327 if ((ia_valid & ATTR_UID && attr->ia_uid != ADFS_SB(sb)->s_uid) ||
328 (ia_valid & ATTR_GID && attr->ia_gid != ADFS_SB(sb)->s_gid))
329 error = -EPERM;
330
331 if (error)
332 goto out;
333
npiggin@suse.de15c6fd92010-05-27 01:05:34 +1000334 /* XXX: this is missing some actual on-disk truncation.. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 if (ia_valid & ATTR_SIZE)
Christoph Hellwig2c27c652010-06-04 11:30:04 +0200336 truncate_setsize(inode, attr->ia_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337
338 if (ia_valid & ATTR_MTIME) {
339 inode->i_mtime = attr->ia_mtime;
340 adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec);
341 }
342 /*
343 * FIXME: should we make these == to i_mtime since we don't
344 * have the ability to represent them in our filesystem?
345 */
346 if (ia_valid & ATTR_ATIME)
347 inode->i_atime = attr->ia_atime;
348 if (ia_valid & ATTR_CTIME)
349 inode->i_ctime = attr->ia_ctime;
350 if (ia_valid & ATTR_MODE) {
351 ADFS_I(inode)->attr = adfs_mode2atts(sb, inode);
352 inode->i_mode = adfs_atts2mode(sb, inode);
353 }
354
355 /*
356 * FIXME: should we be marking this inode dirty even if
357 * we don't have any metadata to write back?
358 */
359 if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE))
360 mark_inode_dirty(inode);
361out:
362 unlock_kernel();
363 return error;
364}
365
366/*
367 * write an existing inode back to the directory, and therefore the disk.
368 * The adfs-specific inode data has already been updated by
369 * adfs_notify_change()
370 */
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100371int adfs_write_inode(struct inode *inode, struct writeback_control *wbc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372{
373 struct super_block *sb = inode->i_sb;
374 struct object_info obj;
375 int ret;
376
377 lock_kernel();
378 obj.file_id = inode->i_ino;
379 obj.name_len = 0;
380 obj.parent_id = ADFS_I(inode)->parent_id;
381 obj.loadaddr = ADFS_I(inode)->loadaddr;
382 obj.execaddr = ADFS_I(inode)->execaddr;
383 obj.attr = ADFS_I(inode)->attr;
384 obj.size = inode->i_size;
385
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100386 ret = adfs_dir_update(sb, &obj, wbc->sync_mode == WB_SYNC_ALL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 unlock_kernel();
388 return ret;
389}