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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/affs/amigaffs.c
3 *
4 * (c) 1996 Hans-Joachim Widmaier - Rewritten
5 *
6 * (C) 1993 Ray Burr - Amiga FFS filesystem.
7 *
8 * Please send bug reports to: hjw@zvw.de
9 */
10
11#include "affs.h"
12
13extern struct timezone sys_tz;
14
15static char ErrorBuffer[256];
16
17/*
18 * Functions for accessing Amiga-FFS structures.
19 */
20
21
22/* Insert a header block bh into the directory dir
23 * caller must hold AFFS_DIR->i_hash_lock!
24 */
25
26int
27affs_insert_hash(struct inode *dir, struct buffer_head *bh)
28{
29 struct super_block *sb = dir->i_sb;
30 struct buffer_head *dir_bh;
31 u32 ino, hash_ino;
32 int offset;
33
34 ino = bh->b_blocknr;
35 offset = affs_hash_name(sb, AFFS_TAIL(sb, bh)->name + 1, AFFS_TAIL(sb, bh)->name[0]);
36
37 pr_debug("AFFS: insert_hash(dir=%u, ino=%d)\n", (u32)dir->i_ino, ino);
38
39 dir_bh = affs_bread(sb, dir->i_ino);
40 if (!dir_bh)
41 return -EIO;
42
43 hash_ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[offset]);
44 while (hash_ino) {
45 affs_brelse(dir_bh);
46 dir_bh = affs_bread(sb, hash_ino);
47 if (!dir_bh)
48 return -EIO;
49 hash_ino = be32_to_cpu(AFFS_TAIL(sb, dir_bh)->hash_chain);
50 }
51 AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino);
52 AFFS_TAIL(sb, bh)->hash_chain = 0;
53 affs_fix_checksum(sb, bh);
54
55 if (dir->i_ino == dir_bh->b_blocknr)
56 AFFS_HEAD(dir_bh)->table[offset] = cpu_to_be32(ino);
57 else
58 AFFS_TAIL(sb, dir_bh)->hash_chain = cpu_to_be32(ino);
59
60 affs_adjust_checksum(dir_bh, ino);
61 mark_buffer_dirty_inode(dir_bh, dir);
62 affs_brelse(dir_bh);
63
64 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
65 dir->i_version++;
66 mark_inode_dirty(dir);
67
68 return 0;
69}
70
71/* Remove a header block from its directory.
72 * caller must hold AFFS_DIR->i_hash_lock!
73 */
74
75int
76affs_remove_hash(struct inode *dir, struct buffer_head *rem_bh)
77{
78 struct super_block *sb;
79 struct buffer_head *bh;
80 u32 rem_ino, hash_ino;
81 __be32 ino;
82 int offset, retval;
83
84 sb = dir->i_sb;
85 rem_ino = rem_bh->b_blocknr;
86 offset = affs_hash_name(sb, AFFS_TAIL(sb, rem_bh)->name+1, AFFS_TAIL(sb, rem_bh)->name[0]);
87 pr_debug("AFFS: remove_hash(dir=%d, ino=%d, hashval=%d)\n", (u32)dir->i_ino, rem_ino, offset);
88
89 bh = affs_bread(sb, dir->i_ino);
90 if (!bh)
91 return -EIO;
92
93 retval = -ENOENT;
94 hash_ino = be32_to_cpu(AFFS_HEAD(bh)->table[offset]);
95 while (hash_ino) {
96 if (hash_ino == rem_ino) {
97 ino = AFFS_TAIL(sb, rem_bh)->hash_chain;
98 if (dir->i_ino == bh->b_blocknr)
99 AFFS_HEAD(bh)->table[offset] = ino;
100 else
101 AFFS_TAIL(sb, bh)->hash_chain = ino;
102 affs_adjust_checksum(bh, be32_to_cpu(ino) - hash_ino);
103 mark_buffer_dirty_inode(bh, dir);
104 AFFS_TAIL(sb, rem_bh)->parent = 0;
105 retval = 0;
106 break;
107 }
108 affs_brelse(bh);
109 bh = affs_bread(sb, hash_ino);
110 if (!bh)
111 return -EIO;
112 hash_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
113 }
114
115 affs_brelse(bh);
116
117 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
118 dir->i_version++;
119 mark_inode_dirty(dir);
120
121 return retval;
122}
123
124static void
Al Viro12447c42012-06-09 13:06:09 -0400125affs_fix_dcache(struct inode *inode, u32 entry_ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126{
Al Viro12447c42012-06-09 13:06:09 -0400127 struct dentry *dentry;
Nick Piggin873feea2011-01-07 17:50:06 +1100128 spin_lock(&inode->i_lock);
Sasha Levinb67bfe02013-02-27 17:06:00 -0800129 hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 if (entry_ino == (u32)(long)dentry->d_fsdata) {
Al Viro12447c42012-06-09 13:06:09 -0400131 dentry->d_fsdata = (void *)inode->i_ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 break;
133 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 }
Nick Piggin873feea2011-01-07 17:50:06 +1100135 spin_unlock(&inode->i_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136}
137
138
139/* Remove header from link chain */
140
141static int
142affs_remove_link(struct dentry *dentry)
143{
144 struct inode *dir, *inode = dentry->d_inode;
145 struct super_block *sb = inode->i_sb;
146 struct buffer_head *bh = NULL, *link_bh = NULL;
147 u32 link_ino, ino;
148 int retval;
149
150 pr_debug("AFFS: remove_link(key=%ld)\n", inode->i_ino);
151 retval = -EIO;
152 bh = affs_bread(sb, inode->i_ino);
153 if (!bh)
154 goto done;
155
156 link_ino = (u32)(long)dentry->d_fsdata;
157 if (inode->i_ino == link_ino) {
158 /* we can't remove the head of the link, as its blocknr is still used as ino,
159 * so we remove the block of the first link instead.
160 */
161 link_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain);
162 link_bh = affs_bread(sb, link_ino);
163 if (!link_bh)
164 goto done;
165
David Howells210f8552008-02-07 00:15:29 -0800166 dir = affs_iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent));
167 if (IS_ERR(dir)) {
168 retval = PTR_ERR(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 goto done;
David Howells210f8552008-02-07 00:15:29 -0800170 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171
172 affs_lock_dir(dir);
Al Viro12447c42012-06-09 13:06:09 -0400173 /*
174 * if there's a dentry for that block, make it
175 * refer to inode itself.
176 */
177 affs_fix_dcache(inode, link_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 retval = affs_remove_hash(dir, link_bh);
Christoph Hellwigec1ab0a2008-05-09 12:35:29 +0200179 if (retval) {
180 affs_unlock_dir(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 goto done;
Christoph Hellwigec1ab0a2008-05-09 12:35:29 +0200182 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 mark_buffer_dirty_inode(link_bh, inode);
184
185 memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32);
186 retval = affs_insert_hash(dir, bh);
Christoph Hellwigec1ab0a2008-05-09 12:35:29 +0200187 if (retval) {
188 affs_unlock_dir(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 goto done;
Christoph Hellwigec1ab0a2008-05-09 12:35:29 +0200190 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 mark_buffer_dirty_inode(bh, inode);
192
193 affs_unlock_dir(dir);
194 iput(dir);
195 } else {
196 link_bh = affs_bread(sb, link_ino);
197 if (!link_bh)
198 goto done;
199 }
200
201 while ((ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain)) != 0) {
202 if (ino == link_ino) {
203 __be32 ino2 = AFFS_TAIL(sb, link_bh)->link_chain;
204 AFFS_TAIL(sb, bh)->link_chain = ino2;
205 affs_adjust_checksum(bh, be32_to_cpu(ino2) - link_ino);
206 mark_buffer_dirty_inode(bh, inode);
207 retval = 0;
208 /* Fix the link count, if bh is a normal header block without links */
209 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
210 case ST_LINKDIR:
211 case ST_LINKFILE:
212 break;
213 default:
214 if (!AFFS_TAIL(sb, bh)->link_chain)
Miklos Szeredibfe86842011-10-28 14:13:29 +0200215 set_nlink(inode, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 }
217 affs_free_block(sb, link_ino);
218 goto done;
219 }
220 affs_brelse(bh);
221 bh = affs_bread(sb, ino);
222 if (!bh)
223 goto done;
224 }
225 retval = -ENOENT;
226done:
227 affs_brelse(link_bh);
228 affs_brelse(bh);
229 return retval;
230}
231
232
233static int
234affs_empty_dir(struct inode *inode)
235{
236 struct super_block *sb = inode->i_sb;
237 struct buffer_head *bh;
238 int retval, size;
239
240 retval = -EIO;
241 bh = affs_bread(sb, inode->i_ino);
242 if (!bh)
243 goto done;
244
245 retval = -ENOTEMPTY;
246 for (size = AFFS_SB(sb)->s_hashsize - 1; size >= 0; size--)
247 if (AFFS_HEAD(bh)->table[size])
248 goto not_empty;
249 retval = 0;
250not_empty:
251 affs_brelse(bh);
252done:
253 return retval;
254}
255
256
257/* Remove a filesystem object. If the object to be removed has
258 * links to it, one of the links must be changed to inherit
259 * the file or directory. As above, any inode will do.
260 * The buffer will not be freed. If the header is a link, the
261 * block will be marked as free.
262 * This function returns a negative error number in case of
263 * an error, else 0 if the inode is to be deleted or 1 if not.
264 */
265
266int
267affs_remove_header(struct dentry *dentry)
268{
269 struct super_block *sb;
270 struct inode *inode, *dir;
271 struct buffer_head *bh = NULL;
272 int retval;
273
274 dir = dentry->d_parent->d_inode;
275 sb = dir->i_sb;
276
277 retval = -ENOENT;
278 inode = dentry->d_inode;
279 if (!inode)
280 goto done;
281
282 pr_debug("AFFS: remove_header(key=%ld)\n", inode->i_ino);
283 retval = -EIO;
284 bh = affs_bread(sb, (u32)(long)dentry->d_fsdata);
285 if (!bh)
286 goto done;
287
288 affs_lock_link(inode);
289 affs_lock_dir(dir);
290 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
291 case ST_USERDIR:
292 /* if we ever want to support links to dirs
293 * i_hash_lock of the inode must only be
294 * taken after some checks
295 */
296 affs_lock_dir(inode);
297 retval = affs_empty_dir(inode);
298 affs_unlock_dir(inode);
299 if (retval)
300 goto done_unlock;
301 break;
302 default:
303 break;
304 }
305
306 retval = affs_remove_hash(dir, bh);
307 if (retval)
308 goto done_unlock;
309 mark_buffer_dirty_inode(bh, inode);
310
311 affs_unlock_dir(dir);
312
313 if (inode->i_nlink > 1)
314 retval = affs_remove_link(dentry);
315 else
Miklos Szeredi6d6b77f2011-10-28 14:13:28 +0200316 clear_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 affs_unlock_link(inode);
318 inode->i_ctime = CURRENT_TIME_SEC;
319 mark_inode_dirty(inode);
320
321done:
322 affs_brelse(bh);
323 return retval;
324
325done_unlock:
326 affs_unlock_dir(dir);
327 affs_unlock_link(inode);
328 goto done;
329}
330
331/* Checksum a block, do various consistency checks and optionally return
332 the blocks type number. DATA points to the block. If their pointers
333 are non-null, *PTYPE and *STYPE are set to the primary and secondary
334 block types respectively, *HASHSIZE is set to the size of the hashtable
335 (which lets us calculate the block size).
336 Returns non-zero if the block is not consistent. */
337
338u32
339affs_checksum_block(struct super_block *sb, struct buffer_head *bh)
340{
341 __be32 *ptr = (__be32 *)bh->b_data;
342 u32 sum;
343 int bsize;
344
345 sum = 0;
346 for (bsize = sb->s_blocksize / sizeof(__be32); bsize > 0; bsize--)
347 sum += be32_to_cpu(*ptr++);
348 return sum;
349}
350
351/*
352 * Calculate the checksum of a disk block and store it
353 * at the indicated position.
354 */
355
356void
357affs_fix_checksum(struct super_block *sb, struct buffer_head *bh)
358{
359 int cnt = sb->s_blocksize / sizeof(__be32);
360 __be32 *ptr = (__be32 *)bh->b_data;
361 u32 checksum;
362 __be32 *checksumptr;
363
364 checksumptr = ptr + 5;
365 *checksumptr = 0;
366 for (checksum = 0; cnt > 0; ptr++, cnt--)
367 checksum += be32_to_cpu(*ptr);
368 *checksumptr = cpu_to_be32(-checksum);
369}
370
371void
372secs_to_datestamp(time_t secs, struct affs_date *ds)
373{
374 u32 days;
375 u32 minute;
376
377 secs -= sys_tz.tz_minuteswest * 60 + ((8 * 365 + 2) * 24 * 60 * 60);
378 if (secs < 0)
379 secs = 0;
380 days = secs / 86400;
381 secs -= days * 86400;
382 minute = secs / 60;
383 secs -= minute * 60;
384
385 ds->days = cpu_to_be32(days);
386 ds->mins = cpu_to_be32(minute);
387 ds->ticks = cpu_to_be32(secs * 50);
388}
389
Al Viroa760b032011-07-26 03:04:30 -0400390umode_t
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391prot_to_mode(u32 prot)
392{
Al Viroa760b032011-07-26 03:04:30 -0400393 umode_t mode = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
395 if (!(prot & FIBF_NOWRITE))
396 mode |= S_IWUSR;
397 if (!(prot & FIBF_NOREAD))
398 mode |= S_IRUSR;
399 if (!(prot & FIBF_NOEXECUTE))
400 mode |= S_IXUSR;
401 if (prot & FIBF_GRP_WRITE)
402 mode |= S_IWGRP;
403 if (prot & FIBF_GRP_READ)
404 mode |= S_IRGRP;
405 if (prot & FIBF_GRP_EXECUTE)
406 mode |= S_IXGRP;
407 if (prot & FIBF_OTR_WRITE)
408 mode |= S_IWOTH;
409 if (prot & FIBF_OTR_READ)
410 mode |= S_IROTH;
411 if (prot & FIBF_OTR_EXECUTE)
412 mode |= S_IXOTH;
413
414 return mode;
415}
416
417void
418mode_to_prot(struct inode *inode)
419{
420 u32 prot = AFFS_I(inode)->i_protect;
Al Viroa760b032011-07-26 03:04:30 -0400421 umode_t mode = inode->i_mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422
423 if (!(mode & S_IXUSR))
424 prot |= FIBF_NOEXECUTE;
425 if (!(mode & S_IRUSR))
426 prot |= FIBF_NOREAD;
427 if (!(mode & S_IWUSR))
428 prot |= FIBF_NOWRITE;
429 if (mode & S_IXGRP)
430 prot |= FIBF_GRP_EXECUTE;
431 if (mode & S_IRGRP)
432 prot |= FIBF_GRP_READ;
433 if (mode & S_IWGRP)
434 prot |= FIBF_GRP_WRITE;
435 if (mode & S_IXOTH)
436 prot |= FIBF_OTR_EXECUTE;
437 if (mode & S_IROTH)
438 prot |= FIBF_OTR_READ;
439 if (mode & S_IWOTH)
440 prot |= FIBF_OTR_WRITE;
441
442 AFFS_I(inode)->i_protect = prot;
443}
444
445void
446affs_error(struct super_block *sb, const char *function, const char *fmt, ...)
447{
448 va_list args;
449
450 va_start(args,fmt);
Alexey Dobriyan4a6e6172006-12-06 20:37:04 -0800451 vsnprintf(ErrorBuffer,sizeof(ErrorBuffer),fmt,args);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 va_end(args);
453
454 printk(KERN_CRIT "AFFS error (device %s): %s(): %s\n", sb->s_id,
455 function,ErrorBuffer);
456 if (!(sb->s_flags & MS_RDONLY))
457 printk(KERN_WARNING "AFFS: Remounting filesystem read-only\n");
458 sb->s_flags |= MS_RDONLY;
459}
460
461void
462affs_warning(struct super_block *sb, const char *function, const char *fmt, ...)
463{
464 va_list args;
465
466 va_start(args,fmt);
Alexey Dobriyan4a6e6172006-12-06 20:37:04 -0800467 vsnprintf(ErrorBuffer,sizeof(ErrorBuffer),fmt,args);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 va_end(args);
469
470 printk(KERN_WARNING "AFFS warning (device %s): %s(): %s\n", sb->s_id,
471 function,ErrorBuffer);
472}
473
474/* Check if the name is valid for a affs object. */
475
476int
477affs_check_name(const unsigned char *name, int len)
478{
479 int i;
480
481 if (len > 30)
482#ifdef AFFS_NO_TRUNCATE
483 return -ENAMETOOLONG;
484#else
485 len = 30;
486#endif
487
488 for (i = 0; i < len; i++) {
489 if (name[i] < ' ' || name[i] == ':'
490 || (name[i] > 0x7e && name[i] < 0xa0))
491 return -EINVAL;
492 }
493
494 return 0;
495}
496
497/* This function copies name to bstr, with at most 30
498 * characters length. The bstr will be prepended by
499 * a length byte.
500 * NOTE: The name will must be already checked by
501 * affs_check_name()!
502 */
503
504int
505affs_copy_name(unsigned char *bstr, struct dentry *dentry)
506{
507 int len = min(dentry->d_name.len, 30u);
508
509 *bstr++ = len;
510 memcpy(bstr, dentry->d_name.name, len);
511 return len;
512}