Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6
[deliverable/linux.git] / fs / adfs / inode.c
CommitLineData
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/buffer_head.h>
a9185b41 11#include <linux/writeback.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 */
18static int
19adfs_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
34abort_toobig:
35 return 0;
36}
37
38static int adfs_writepage(struct page *page, struct writeback_control *wbc)
39{
40 return block_write_full_page(page, adfs_get_block, wbc);
41}
42
43static int adfs_readpage(struct file *file, struct page *page)
44{
45 return block_read_full_page(page, adfs_get_block);
46}
47
b4585729
NP
48static 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{
282dc178
CH
52 int ret;
53
b4585729 54 *pagep = NULL;
282dc178 55 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
b4585729
NP
56 adfs_get_block,
57 &ADFS_I(mapping->host)->mmu_private);
282dc178
CH
58 if (unlikely(ret)) {
59 loff_t isize = mapping->host->i_size;
60 if (pos + len > isize)
61 vmtruncate(mapping->host, isize);
62 }
63
64 return ret;
1da177e4
LT
65}
66
67static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
68{
69 return generic_block_bmap(mapping, block, adfs_get_block);
70}
71
f5e54d6e 72static const struct address_space_operations adfs_aops = {
1da177e4
LT
73 .readpage = adfs_readpage,
74 .writepage = adfs_writepage,
75 .sync_page = block_sync_page,
b4585729
NP
76 .write_begin = adfs_write_begin,
77 .write_end = generic_write_end,
1da177e4
LT
78 .bmap = _adfs_bmap
79};
80
81static inline unsigned int
82adfs_filetype(struct inode *inode)
83{
84 unsigned int type;
85
86 if (ADFS_I(inode)->stamped)
87 type = (ADFS_I(inode)->loadaddr >> 8) & 0xfff;
88 else
89 type = (unsigned int) -1;
90
91 return type;
92}
93
94/*
95 * Convert ADFS attributes and filetype to Linux permission.
96 */
97static umode_t
98adfs_atts2mode(struct super_block *sb, struct inode *inode)
99{
100 unsigned int filetype, attr = ADFS_I(inode)->attr;
101 umode_t mode, rmask;
102 struct adfs_sb_info *asb = ADFS_SB(sb);
103
104 if (attr & ADFS_NDA_DIRECTORY) {
105 mode = S_IRUGO & asb->s_owner_mask;
106 return S_IFDIR | S_IXUGO | mode;
107 }
108
109 filetype = adfs_filetype(inode);
110
111 switch (filetype) {
112 case 0xfc0: /* LinkFS */
113 return S_IFLNK|S_IRWXUGO;
114
115 case 0xfe6: /* UnixExec */
116 rmask = S_IRUGO | S_IXUGO;
117 break;
118
119 default:
120 rmask = S_IRUGO;
121 }
122
123 mode = S_IFREG;
124
125 if (attr & ADFS_NDA_OWNER_READ)
126 mode |= rmask & asb->s_owner_mask;
127
128 if (attr & ADFS_NDA_OWNER_WRITE)
129 mode |= S_IWUGO & asb->s_owner_mask;
130
131 if (attr & ADFS_NDA_PUBLIC_READ)
132 mode |= rmask & asb->s_other_mask;
133
134 if (attr & ADFS_NDA_PUBLIC_WRITE)
135 mode |= S_IWUGO & asb->s_other_mask;
136 return mode;
137}
138
139/*
140 * Convert Linux permission to ADFS attribute. We try to do the reverse
141 * of atts2mode, but there is not a 1:1 translation.
142 */
143static int
144adfs_mode2atts(struct super_block *sb, struct inode *inode)
145{
146 umode_t mode;
147 int attr;
148 struct adfs_sb_info *asb = ADFS_SB(sb);
149
150 /* FIXME: should we be able to alter a link? */
151 if (S_ISLNK(inode->i_mode))
152 return ADFS_I(inode)->attr;
153
154 if (S_ISDIR(inode->i_mode))
155 attr = ADFS_NDA_DIRECTORY;
156 else
157 attr = 0;
158
159 mode = inode->i_mode & asb->s_owner_mask;
160 if (mode & S_IRUGO)
161 attr |= ADFS_NDA_OWNER_READ;
162 if (mode & S_IWUGO)
163 attr |= ADFS_NDA_OWNER_WRITE;
164
165 mode = inode->i_mode & asb->s_other_mask;
166 mode &= ~asb->s_owner_mask;
167 if (mode & S_IRUGO)
168 attr |= ADFS_NDA_PUBLIC_READ;
169 if (mode & S_IWUGO)
170 attr |= ADFS_NDA_PUBLIC_WRITE;
171
172 return attr;
173}
174
175/*
176 * Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time
177 * referenced to 1 Jan 1900 (til 2248)
178 */
179static void
180adfs_adfs2unix_time(struct timespec *tv, struct inode *inode)
181{
182 unsigned int high, low;
183
184 if (ADFS_I(inode)->stamped == 0)
185 goto cur_time;
186
187 high = ADFS_I(inode)->loadaddr << 24;
188 low = ADFS_I(inode)->execaddr;
189
190 high |= low >> 8;
191 low &= 255;
192
193 /* Files dated pre 01 Jan 1970 00:00:00. */
194 if (high < 0x336e996a)
195 goto too_early;
196
197 /* Files dated post 18 Jan 2038 03:14:05. */
198 if (high >= 0x656e9969)
199 goto too_late;
200
201 /* discard 2208988800 (0x336e996a00) seconds of time */
202 high -= 0x336e996a;
203
204 /* convert 40-bit centi-seconds to 32-bit seconds */
205 tv->tv_sec = (((high % 100) << 8) + low) / 100 + (high / 100 << 8);
206 tv->tv_nsec = 0;
207 return;
208
209 cur_time:
210 *tv = CURRENT_TIME_SEC;
211 return;
212
213 too_early:
214 tv->tv_sec = tv->tv_nsec = 0;
215 return;
216
217 too_late:
218 tv->tv_sec = 0x7ffffffd;
219 tv->tv_nsec = 0;
220 return;
221}
222
223/*
224 * Convert an Unix time to ADFS time. We only do this if the entry has a
225 * time/date stamp already.
226 */
227static void
228adfs_unix2adfs_time(struct inode *inode, unsigned int secs)
229{
230 unsigned int high, low;
231
232 if (ADFS_I(inode)->stamped) {
233 /* convert 32-bit seconds to 40-bit centi-seconds */
234 low = (secs & 255) * 100;
235 high = (secs / 256) * 100 + (low >> 8) + 0x336e996a;
236
237 ADFS_I(inode)->loadaddr = (high >> 24) |
238 (ADFS_I(inode)->loadaddr & ~0xff);
239 ADFS_I(inode)->execaddr = (low & 255) | (high << 8);
240 }
241}
242
243/*
244 * Fill in the inode information from the object information.
245 *
246 * Note that this is an inode-less filesystem, so we can't use the inode
247 * number to reference the metadata on the media. Instead, we use the
248 * inode number to hold the object ID, which in turn will tell us where
249 * the data is held. We also save the parent object ID, and with these
250 * two, we can locate the metadata.
251 *
252 * This does mean that we rely on an objects parent remaining the same at
253 * all times - we cannot cope with a cross-directory rename (yet).
254 */
255struct inode *
256adfs_iget(struct super_block *sb, struct object_info *obj)
257{
258 struct inode *inode;
259
260 inode = new_inode(sb);
261 if (!inode)
262 goto out;
263
264 inode->i_uid = ADFS_SB(sb)->s_uid;
265 inode->i_gid = ADFS_SB(sb)->s_gid;
266 inode->i_ino = obj->file_id;
267 inode->i_size = obj->size;
268 inode->i_nlink = 2;
1da177e4
LT
269 inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >>
270 sb->s_blocksize_bits;
271
272 /*
273 * we need to save the parent directory ID so that
274 * write_inode can update the directory information
275 * for this file. This will need special handling
276 * for cross-directory renames.
277 */
278 ADFS_I(inode)->parent_id = obj->parent_id;
279 ADFS_I(inode)->loadaddr = obj->loadaddr;
280 ADFS_I(inode)->execaddr = obj->execaddr;
281 ADFS_I(inode)->attr = obj->attr;
282 ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000);
283
284 inode->i_mode = adfs_atts2mode(sb, inode);
285 adfs_adfs2unix_time(&inode->i_mtime, inode);
286 inode->i_atime = inode->i_mtime;
287 inode->i_ctime = inode->i_mtime;
288
289 if (S_ISDIR(inode->i_mode)) {
290 inode->i_op = &adfs_dir_inode_operations;
291 inode->i_fop = &adfs_dir_operations;
292 } else if (S_ISREG(inode->i_mode)) {
293 inode->i_op = &adfs_file_inode_operations;
294 inode->i_fop = &adfs_file_operations;
295 inode->i_mapping->a_ops = &adfs_aops;
296 ADFS_I(inode)->mmu_private = inode->i_size;
297 }
298
299 insert_inode_hash(inode);
300
301out:
302 return inode;
303}
304
305/*
306 * Validate and convert a changed access mode/time to their ADFS equivalents.
307 * adfs_write_inode will actually write the information back to the directory
308 * later.
309 */
310int
311adfs_notify_change(struct dentry *dentry, struct iattr *attr)
312{
313 struct inode *inode = dentry->d_inode;
314 struct super_block *sb = inode->i_sb;
315 unsigned int ia_valid = attr->ia_valid;
316 int error;
317
1da177e4
LT
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
15c6fd97 331 /* XXX: this is missing some actual on-disk truncation.. */
1da177e4 332 if (ia_valid & ATTR_SIZE)
2c27c65e 333 truncate_setsize(inode, attr->ia_size);
1da177e4
LT
334
335 if (ia_valid & ATTR_MTIME) {
336 inode->i_mtime = attr->ia_mtime;
337 adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec);
338 }
339 /*
340 * FIXME: should we make these == to i_mtime since we don't
341 * have the ability to represent them in our filesystem?
342 */
343 if (ia_valid & ATTR_ATIME)
344 inode->i_atime = attr->ia_atime;
345 if (ia_valid & ATTR_CTIME)
346 inode->i_ctime = attr->ia_ctime;
347 if (ia_valid & ATTR_MODE) {
348 ADFS_I(inode)->attr = adfs_mode2atts(sb, inode);
349 inode->i_mode = adfs_atts2mode(sb, inode);
350 }
351
352 /*
353 * FIXME: should we be marking this inode dirty even if
354 * we don't have any metadata to write back?
355 */
356 if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE))
357 mark_inode_dirty(inode);
358out:
1da177e4
LT
359 return error;
360}
361
362/*
363 * write an existing inode back to the directory, and therefore the disk.
364 * The adfs-specific inode data has already been updated by
365 * adfs_notify_change()
366 */
a9185b41 367int adfs_write_inode(struct inode *inode, struct writeback_control *wbc)
1da177e4
LT
368{
369 struct super_block *sb = inode->i_sb;
370 struct object_info obj;
371 int ret;
372
1da177e4
LT
373 obj.file_id = inode->i_ino;
374 obj.name_len = 0;
375 obj.parent_id = ADFS_I(inode)->parent_id;
376 obj.loadaddr = ADFS_I(inode)->loadaddr;
377 obj.execaddr = ADFS_I(inode)->execaddr;
378 obj.attr = ADFS_I(inode)->attr;
379 obj.size = inode->i_size;
380
a9185b41 381 ret = adfs_dir_update(sb, &obj, wbc->sync_mode == WB_SYNC_ALL);
1da177e4
LT
382 return ret;
383}
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