1 // SPDX-License-Identifier: GPL-2.0
3 * linux/fs/affs/amigaffs.c
5 * (c) 1996 Hans-Joachim Widmaier - Rewritten
7 * (C) 1993 Ray Burr - Amiga FFS filesystem.
9 * Please send bug reports to: hjw@zvw.de
12 #include <linux/math64.h>
13 #include <linux/iversion.h>
17 * Functions for accessing Amiga-FFS structures.
21 /* Insert a header block bh into the directory dir
22 * caller must hold AFFS_DIR->i_hash_lock!
26 affs_insert_hash(struct inode
*dir
, struct buffer_head
*bh
)
28 struct super_block
*sb
= dir
->i_sb
;
29 struct buffer_head
*dir_bh
;
34 offset
= affs_hash_name(sb
, AFFS_TAIL(sb
, bh
)->name
+ 1, AFFS_TAIL(sb
, bh
)->name
[0]);
36 pr_debug("%s(dir=%lu, ino=%d)\n", __func__
, dir
->i_ino
, ino
);
38 dir_bh
= affs_bread(sb
, dir
->i_ino
);
42 hash_ino
= be32_to_cpu(AFFS_HEAD(dir_bh
)->table
[offset
]);
45 dir_bh
= affs_bread(sb
, hash_ino
);
48 hash_ino
= be32_to_cpu(AFFS_TAIL(sb
, dir_bh
)->hash_chain
);
50 AFFS_TAIL(sb
, bh
)->parent
= cpu_to_be32(dir
->i_ino
);
51 AFFS_TAIL(sb
, bh
)->hash_chain
= 0;
52 affs_fix_checksum(sb
, bh
);
54 if (dir
->i_ino
== dir_bh
->b_blocknr
)
55 AFFS_HEAD(dir_bh
)->table
[offset
] = cpu_to_be32(ino
);
57 AFFS_TAIL(sb
, dir_bh
)->hash_chain
= cpu_to_be32(ino
);
59 affs_adjust_checksum(dir_bh
, ino
);
60 mark_buffer_dirty_inode(dir_bh
, dir
);
63 inode_set_mtime_to_ts(dir
, inode_set_ctime_current(dir
));
64 inode_inc_iversion(dir
);
65 mark_inode_dirty(dir
);
70 /* Remove a header block from its directory.
71 * caller must hold AFFS_DIR->i_hash_lock!
75 affs_remove_hash(struct inode
*dir
, struct buffer_head
*rem_bh
)
77 struct super_block
*sb
;
78 struct buffer_head
*bh
;
79 u32 rem_ino
, hash_ino
;
84 rem_ino
= rem_bh
->b_blocknr
;
85 offset
= affs_hash_name(sb
, AFFS_TAIL(sb
, rem_bh
)->name
+1, AFFS_TAIL(sb
, rem_bh
)->name
[0]);
86 pr_debug("%s(dir=%lu, ino=%d, hashval=%d)\n", __func__
, dir
->i_ino
,
89 bh
= affs_bread(sb
, dir
->i_ino
);
94 hash_ino
= be32_to_cpu(AFFS_HEAD(bh
)->table
[offset
]);
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
;
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;
109 bh
= affs_bread(sb
, hash_ino
);
112 hash_ino
= be32_to_cpu(AFFS_TAIL(sb
, bh
)->hash_chain
);
117 inode_set_mtime_to_ts(dir
, inode_set_ctime_current(dir
));
118 inode_inc_iversion(dir
);
119 mark_inode_dirty(dir
);
125 affs_fix_dcache(struct inode
*inode
, u32 entry_ino
)
127 struct dentry
*dentry
;
128 spin_lock(&inode
->i_lock
);
129 hlist_for_each_entry(dentry
, &inode
->i_dentry
, d_u
.d_alias
) {
130 if (entry_ino
== (u32
)(long)dentry
->d_fsdata
) {
131 dentry
->d_fsdata
= (void *)inode
->i_ino
;
135 spin_unlock(&inode
->i_lock
);
139 /* Remove header from link chain */
142 affs_remove_link(struct dentry
*dentry
)
144 struct inode
*dir
, *inode
= d_inode(dentry
);
145 struct super_block
*sb
= inode
->i_sb
;
146 struct buffer_head
*bh
, *link_bh
= NULL
;
150 pr_debug("%s(key=%ld)\n", __func__
, inode
->i_ino
);
152 bh
= affs_bread(sb
, inode
->i_ino
);
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.
161 link_ino
= be32_to_cpu(AFFS_TAIL(sb
, bh
)->link_chain
);
162 link_bh
= affs_bread(sb
, link_ino
);
166 dir
= affs_iget(sb
, be32_to_cpu(AFFS_TAIL(sb
, link_bh
)->parent
));
168 retval
= PTR_ERR(dir
);
174 * if there's a dentry for that block, make it
175 * refer to inode itself.
177 affs_fix_dcache(inode
, link_ino
);
178 retval
= affs_remove_hash(dir
, link_bh
);
180 affs_unlock_dir(dir
);
183 mark_buffer_dirty_inode(link_bh
, inode
);
185 memcpy(AFFS_TAIL(sb
, bh
)->name
, AFFS_TAIL(sb
, link_bh
)->name
, 32);
186 retval
= affs_insert_hash(dir
, bh
);
188 affs_unlock_dir(dir
);
191 mark_buffer_dirty_inode(bh
, inode
);
193 affs_unlock_dir(dir
);
196 link_bh
= affs_bread(sb
, link_ino
);
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
);
208 /* Fix the link count, if bh is a normal header block without links */
209 switch (be32_to_cpu(AFFS_TAIL(sb
, bh
)->stype
)) {
214 if (!AFFS_TAIL(sb
, bh
)->link_chain
)
217 affs_free_block(sb
, link_ino
);
221 bh
= affs_bread(sb
, ino
);
227 affs_brelse(link_bh
);
234 affs_empty_dir(struct inode
*inode
)
236 struct super_block
*sb
= inode
->i_sb
;
237 struct buffer_head
*bh
;
241 bh
= affs_bread(sb
, inode
->i_ino
);
246 for (size
= AFFS_SB(sb
)->s_hashsize
- 1; size
>= 0; size
--)
247 if (AFFS_HEAD(bh
)->table
[size
])
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.
267 affs_remove_header(struct dentry
*dentry
)
269 struct super_block
*sb
;
270 struct inode
*inode
, *dir
;
271 struct buffer_head
*bh
= NULL
;
274 dir
= d_inode(dentry
->d_parent
);
278 inode
= d_inode(dentry
);
282 pr_debug("%s(key=%ld)\n", __func__
, inode
->i_ino
);
284 bh
= affs_bread(sb
, (u32
)(long)dentry
->d_fsdata
);
288 affs_lock_link(inode
);
290 switch (be32_to_cpu(AFFS_TAIL(sb
, bh
)->stype
)) {
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
296 affs_lock_dir(inode
);
297 retval
= affs_empty_dir(inode
);
298 affs_unlock_dir(inode
);
306 retval
= affs_remove_hash(dir
, bh
);
309 mark_buffer_dirty_inode(bh
, inode
);
311 affs_unlock_dir(dir
);
313 if (inode
->i_nlink
> 1)
314 retval
= affs_remove_link(dentry
);
317 affs_unlock_link(inode
);
318 inode_set_ctime_current(inode
);
319 mark_inode_dirty(inode
);
326 affs_unlock_dir(dir
);
327 affs_unlock_link(inode
);
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. */
339 affs_checksum_block(struct super_block
*sb
, struct buffer_head
*bh
)
341 __be32
*ptr
= (__be32
*)bh
->b_data
;
346 for (bsize
= sb
->s_blocksize
/ sizeof(__be32
); bsize
> 0; bsize
--)
347 sum
+= be32_to_cpu(*ptr
++);
352 * Calculate the checksum of a disk block and store it
353 * at the indicated position.
357 affs_fix_checksum(struct super_block
*sb
, struct buffer_head
*bh
)
359 int cnt
= sb
->s_blocksize
/ sizeof(__be32
);
360 __be32
*ptr
= (__be32
*)bh
->b_data
;
364 checksumptr
= ptr
+ 5;
366 for (checksum
= 0; cnt
> 0; ptr
++, cnt
--)
367 checksum
+= be32_to_cpu(*ptr
);
368 *checksumptr
= cpu_to_be32(-checksum
);
372 affs_secs_to_datestamp(time64_t secs
, struct affs_date
*ds
)
378 secs
-= sys_tz
.tz_minuteswest
* 60 + AFFS_EPOCH_DELTA
;
381 days
= div_s64_rem(secs
, 86400, &rem
);
385 ds
->days
= cpu_to_be32(days
);
386 ds
->mins
= cpu_to_be32(minute
);
387 ds
->ticks
= cpu_to_be32(rem
* 50);
391 affs_prot_to_mode(u32 prot
)
395 if (!(prot
& FIBF_NOWRITE
))
397 if (!(prot
& FIBF_NOREAD
))
399 if (!(prot
& FIBF_NOEXECUTE
))
401 if (prot
& FIBF_GRP_WRITE
)
403 if (prot
& FIBF_GRP_READ
)
405 if (prot
& FIBF_GRP_EXECUTE
)
407 if (prot
& FIBF_OTR_WRITE
)
409 if (prot
& FIBF_OTR_READ
)
411 if (prot
& FIBF_OTR_EXECUTE
)
418 affs_mode_to_prot(struct inode
*inode
)
420 u32 prot
= AFFS_I(inode
)->i_protect
;
421 umode_t mode
= inode
->i_mode
;
424 * First, clear all RWED bits for owner, group, other.
425 * Then, recalculate them afresh.
427 * We'll always clear the delete-inhibit bit for the owner, as that is
428 * the classic single-user mode AmigaOS protection bit and we need to
429 * stay compatible with all scenarios.
431 * Since multi-user AmigaOS is an extension, we'll only set the
432 * delete-allow bit if any of the other bits in the same user class
433 * (group/other) are used.
435 prot
&= ~(FIBF_NOEXECUTE
| FIBF_NOREAD
436 | FIBF_NOWRITE
| FIBF_NODELETE
437 | FIBF_GRP_EXECUTE
| FIBF_GRP_READ
438 | FIBF_GRP_WRITE
| FIBF_GRP_DELETE
439 | FIBF_OTR_EXECUTE
| FIBF_OTR_READ
440 | FIBF_OTR_WRITE
| FIBF_OTR_DELETE
);
442 /* Classic single-user AmigaOS flags. These are inverted. */
444 prot
|= FIBF_NOEXECUTE
;
448 prot
|= FIBF_NOWRITE
;
450 /* Multi-user extended flags. Not inverted. */
452 prot
|= FIBF_GRP_EXECUTE
;
454 prot
|= FIBF_GRP_READ
;
456 prot
|= FIBF_GRP_WRITE
;
458 prot
|= FIBF_GRP_DELETE
;
461 prot
|= FIBF_OTR_EXECUTE
;
463 prot
|= FIBF_OTR_READ
;
465 prot
|= FIBF_OTR_WRITE
;
467 prot
|= FIBF_OTR_DELETE
;
469 AFFS_I(inode
)->i_protect
= prot
;
473 affs_error(struct super_block
*sb
, const char *function
, const char *fmt
, ...)
475 struct va_format vaf
;
481 pr_crit("error (device %s): %s(): %pV\n", sb
->s_id
, function
, &vaf
);
483 pr_warn("Remounting filesystem read-only\n");
484 sb
->s_flags
|= SB_RDONLY
;
489 affs_warning(struct super_block
*sb
, const char *function
, const char *fmt
, ...)
491 struct va_format vaf
;
497 pr_warn("(device %s): %s(): %pV\n", sb
->s_id
, function
, &vaf
);
502 affs_nofilenametruncate(const struct dentry
*dentry
)
504 return affs_test_opt(AFFS_SB(dentry
->d_sb
)->s_flags
, SF_NO_TRUNCATE
);
507 /* Check if the name is valid for a affs object. */
510 affs_check_name(const unsigned char *name
, int len
, bool notruncate
)
514 if (len
> AFFSNAMEMAX
) {
516 return -ENAMETOOLONG
;
519 for (i
= 0; i
< len
; i
++) {
520 if (name
[i
] < ' ' || name
[i
] == ':'
521 || (name
[i
] > 0x7e && name
[i
] < 0xa0))
528 /* This function copies name to bstr, with at most 30
529 * characters length. The bstr will be prepended by
531 * NOTE: The name will must be already checked by
536 affs_copy_name(unsigned char *bstr
, struct dentry
*dentry
)
538 u32 len
= min(dentry
->d_name
.len
, AFFSNAMEMAX
);
541 memcpy(bstr
, dentry
->d_name
.name
, len
);