2 * linux/fs/hpfs/alloc.c
4 * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
6 * HPFS bitmap operations
12 * Check if a sector is allocated in bitmap
13 * This is really slow. Turned on only if chk==2
16 static int chk_if_allocated(struct super_block
*s
, secno sec
, char *msg
)
18 struct quad_buffer_head qbh
;
20 if (!(bmp
= hpfs_map_bitmap(s
, sec
>> 14, &qbh
, "chk"))) goto fail
;
21 if ((bmp
[(sec
& 0x3fff) >> 5] >> (sec
& 0x1f)) & 1) {
22 hpfs_error(s
, "sector '%s' - %08x not allocated in bitmap", msg
, sec
);
26 if (sec
>= s
->s_hpfs_dirband_start
&& sec
< s
->s_hpfs_dirband_start
+ s
->s_hpfs_dirband_size
) {
27 unsigned ssec
= (sec
- s
->s_hpfs_dirband_start
) / 4;
28 if (!(bmp
= hpfs_map_dnode_bitmap(s
, &qbh
))) goto fail
;
29 if ((bmp
[ssec
>> 5] >> (ssec
& 0x1f)) & 1) {
30 hpfs_error(s
, "sector '%s' - %08x not allocated in directory bitmap", msg
, sec
);
43 * Check if sector(s) have proper number and additionally check if they're
44 * allocated in bitmap.
47 int hpfs_chk_sectors(struct super_block
*s
, secno start
, int len
, char *msg
)
49 if (start
+ len
< start
|| start
< 0x12 ||
50 start
+ len
> s
->s_hpfs_fs_size
) {
51 hpfs_error(s
, "sector(s) '%s' badly placed at %08x", msg
, start
);
54 if (s
->s_hpfs_chk
>=2) {
56 for (i
= 0; i
< len
; i
++)
57 if (chk_if_allocated(s
, start
+ i
, msg
)) return 1;
62 static secno
alloc_in_bmp(struct super_block
*s
, secno near
, unsigned n
, unsigned forward
)
64 struct quad_buffer_head qbh
;
66 unsigned bs
= near
& ~0x3fff;
67 unsigned nr
= (near
& 0x3fff) & ~(n
- 1);
72 if (n
!= 1 && n
!= 4) {
73 hpfs_error(s
, "Bad allocation size: %d", n
);
78 if (!(bmp
= hpfs_map_bitmap(s
, near
>> 14, &qbh
, "aib"))) goto uls
;
80 if (!(bmp
= hpfs_map_dnode_bitmap(s
, &qbh
))) goto uls
;
82 /*if (!tstbits(bmp, nr + n, n + forward)) {
86 if (!tstbits(bmp, nr + 2*n, n + forward)) {
91 while ((a
= tstbits(bmp
, q
, n
+ forward
))) {
93 if (n
!= 1) q
= ((q
-1)&~(n
-1))+n
;
99 } else if (q
> nr
) break;
106 for (i
= nr
+ 1; i
!= nr
; i
++, i
&= 0x1ff) {
107 if (!bmp
[i
]) continue;
108 if (n
+ forward
>= 0x3f && bmp
[i
] != -1) continue;
111 unsigned k
= bmp
[i
-1];
112 while (k
& 0x80000000) {
116 if (n
!= 1) q
= ((q
-1)&~(n
-1))+n
;
117 while ((a
= tstbits(bmp
, q
, n
+ forward
))) {
119 if (n
!= 1) q
= ((q
-1)&~(n
-1))+n
;
129 if (s
->s_hpfs_chk
&& ((ret
>> 14) != (bs
>> 14) || (bmp
[(ret
& 0x3fff) >> 5] | ~(((1 << n
) - 1) << (ret
& 0x1f))) != 0xffffffff)) {
130 hpfs_error(s
, "Allocation doesn't work! Wanted %d, allocated at %08x", n
, ret
);
134 bmp
[(ret
& 0x3fff) >> 5] &= ~(((1 << n
) - 1) << (ret
& 0x1f));
135 hpfs_mark_4buffers_dirty(&qbh
);
145 * Allocation strategy: 1) search place near the sector specified
146 * 2) search bitmap where free sectors last found
147 * 3) search all bitmaps
148 * 4) search all bitmaps ignoring number of pre-allocated
152 secno
hpfs_alloc_sector(struct super_block
*s
, secno near
, unsigned n
, int forward
, int lock
)
157 int b
= s
->s_hpfs_c_bitmap
;
163 if (lock
) hpfs_lock_creation(s
);
164 if (near
&& near
< s
->s_hpfs_fs_size
)
165 if ((sec
= alloc_in_bmp(s
, near
, n
, f_p
? forward
: forward
/4))) goto ret
;
167 if ((sec
= alloc_in_bmp(s
, b
<<14, n
, f_p
? forward
: forward
/2))) {
171 if (b
> 0x10000000) if ((sec
= alloc_in_bmp(s
, (b
&0xfffffff)<<14, n
, f_p
? forward
: 0))) goto ret
;
173 n_bmps
= (s
->s_hpfs_fs_size
+ 0x4000 - 1) >> 14;
174 for (i
= 0; i
< n_bmps
/ 2; i
++) {
175 if ((sec
= alloc_in_bmp(s
, (n_bmps
/2+i
) << 14, n
, forward
))) {
176 s
->s_hpfs_c_bitmap
= n_bmps
/2+i
;
179 if ((sec
= alloc_in_bmp(s
, (n_bmps
/2-i
-1) << 14, n
, forward
))) {
180 s
->s_hpfs_c_bitmap
= n_bmps
/2-i
-1;
184 if ((sec
= alloc_in_bmp(s
, (n_bmps
-1) << 14, n
, forward
))) {
185 s
->s_hpfs_c_bitmap
= n_bmps
-1;
189 for (i
= 0; i
< n_bmps
; i
++)
190 if ((sec
= alloc_in_bmp(s
, i
<< 14, n
, 0))) {
191 s
->s_hpfs_c_bitmap
= 0x10000000 + i
;
198 for (i
= 0; i
< forward
; i
++) {
199 if (!hpfs_alloc_if_possible_nolock(s
, sec
+ i
+ 1)) {
200 hpfs_error(s
, "Prealloc doesn't work! Wanted %d, allocated at %08x, can't allocate %d", forward
, sec
, i
);
206 if (lock
) hpfs_unlock_creation(s
);
210 static secno
alloc_in_dirband(struct super_block
*s
, secno near
, int lock
)
214 if (nr
< s
->s_hpfs_dirband_start
)
215 nr
= s
->s_hpfs_dirband_start
;
216 if (nr
>= s
->s_hpfs_dirband_start
+ s
->s_hpfs_dirband_size
)
217 nr
= s
->s_hpfs_dirband_start
+ s
->s_hpfs_dirband_size
- 4;
218 nr
-= s
->s_hpfs_dirband_start
;
220 if (lock
) hpfs_lock_creation(s
);
221 sec
= alloc_in_bmp(s
, (~0x3fff) | nr
, 1, 0);
222 if (lock
) hpfs_unlock_creation(s
);
224 return ((sec
& 0x3fff) << 2) + s
->s_hpfs_dirband_start
;
227 /* Alloc sector if it's free */
229 int hpfs_alloc_if_possible_nolock(struct super_block
*s
, secno sec
)
231 struct quad_buffer_head qbh
;
234 if (!(bmp
= hpfs_map_bitmap(s
, sec
>> 14, &qbh
, "aip"))) goto end
;
235 if (bmp
[(sec
& 0x3fff) >> 5] & (1 << (sec
& 0x1f))) {
236 bmp
[(sec
& 0x3fff) >> 5] &= ~(1 << (sec
& 0x1f));
237 hpfs_mark_4buffers_dirty(&qbh
);
248 int hpfs_alloc_if_possible(struct super_block
*s
, secno sec
)
251 hpfs_lock_creation(s
);
252 r
= hpfs_alloc_if_possible_nolock(s
, sec
);
253 hpfs_unlock_creation(s
);
257 /* Free sectors in bitmaps */
259 void hpfs_free_sectors(struct super_block
*s
, secno sec
, unsigned n
)
261 struct quad_buffer_head qbh
;
266 hpfs_error(s
, "Trying to free reserved sector %08x", sec
);
271 if (!(bmp
= hpfs_map_bitmap(s
, sec
>> 14, &qbh
, "free"))) {
276 if ((bmp
[(sec
& 0x3fff) >> 5] >> (sec
& 0x1f) & 1)) {
277 hpfs_error(s
, "sector %08x not allocated", sec
);
282 bmp
[(sec
& 0x3fff) >> 5] |= 1 << (sec
& 0x1f);
284 hpfs_mark_4buffers_dirty(&qbh
);
289 if (!(++sec
& 0x3fff)) {
290 hpfs_mark_4buffers_dirty(&qbh
);
298 * Check if there are at least n free dnodes on the filesystem.
299 * Called before adding to dnode. If we run out of space while
300 * splitting dnodes, it would corrupt dnode tree.
303 int hpfs_check_free_dnodes(struct super_block
*s
, int n
)
305 int n_bmps
= (s
->s_hpfs_fs_size
+ 0x4000 - 1) >> 14;
306 int b
= s
->s_hpfs_c_bitmap
& 0x0fffffff;
309 struct quad_buffer_head qbh
;
310 if ((bmp
= hpfs_map_dnode_bitmap(s
, &qbh
))) {
311 for (j
= 0; j
< 512; j
++) {
313 if (!bmp
[j
]) continue;
314 for (k
= bmp
[j
]; k
; k
>>= 1) if (k
& 1) if (!--n
) {
322 if (s
->s_hpfs_c_bitmap
!= -1 ) {
323 bmp
= hpfs_map_bitmap(s
, b
, &qbh
, "chkdn1");
328 if (i
>= n_bmps
) return 1;
329 bmp
= hpfs_map_bitmap(s
, i
, &qbh
, "chkdn2");
332 for (j
= 0; j
< 512; j
++) {
334 if (!bmp
[j
]) continue;
335 for (k
= 0xf; k
; k
<<= 4)
336 if ((bmp
[j
] & k
) == k
) {
349 void hpfs_free_dnode(struct super_block
*s
, dnode_secno dno
)
351 if (s
->s_hpfs_chk
) if (dno
& 3) {
352 hpfs_error(s
, "hpfs_free_dnode: dnode %08x not aligned", dno
);
355 if (dno
< s
->s_hpfs_dirband_start
||
356 dno
>= s
->s_hpfs_dirband_start
+ s
->s_hpfs_dirband_size
) {
357 hpfs_free_sectors(s
, dno
, 4);
359 struct quad_buffer_head qbh
;
361 unsigned ssec
= (dno
- s
->s_hpfs_dirband_start
) / 4;
363 if (!(bmp
= hpfs_map_dnode_bitmap(s
, &qbh
))) {
367 bmp
[ssec
>> 5] |= 1 << (ssec
& 0x1f);
368 hpfs_mark_4buffers_dirty(&qbh
);
374 struct dnode
*hpfs_alloc_dnode(struct super_block
*s
, secno near
,
375 dnode_secno
*dno
, struct quad_buffer_head
*qbh
,
379 if (hpfs_count_one_bitmap(s
, s
->s_hpfs_dmap
) > FREE_DNODES_ADD
) {
380 if (!(*dno
= alloc_in_dirband(s
, near
, lock
)))
381 if (!(*dno
= hpfs_alloc_sector(s
, near
, 4, 0, lock
))) return NULL
;
383 if (!(*dno
= hpfs_alloc_sector(s
, near
, 4, 0, lock
)))
384 if (!(*dno
= alloc_in_dirband(s
, near
, lock
))) return NULL
;
386 if (!(d
= hpfs_get_4sectors(s
, *dno
, qbh
))) {
387 hpfs_free_dnode(s
, *dno
);
391 d
->magic
= DNODE_MAGIC
;
401 struct fnode
*hpfs_alloc_fnode(struct super_block
*s
, secno near
, fnode_secno
*fno
,
402 struct buffer_head
**bh
)
405 if (!(*fno
= hpfs_alloc_sector(s
, near
, 1, FNODE_ALLOC_FWD
, 1))) return NULL
;
406 if (!(f
= hpfs_get_sector(s
, *fno
, bh
))) {
407 hpfs_free_sectors(s
, *fno
, 1);
411 f
->magic
= FNODE_MAGIC
;
413 f
->btree
.n_free_nodes
= 8;
414 f
->btree
.first_free
= 8;
418 struct anode
*hpfs_alloc_anode(struct super_block
*s
, secno near
, anode_secno
*ano
,
419 struct buffer_head
**bh
)
422 if (!(*ano
= hpfs_alloc_sector(s
, near
, 1, ANODE_ALLOC_FWD
, 1))) return NULL
;
423 if (!(a
= hpfs_get_sector(s
, *ano
, bh
))) {
424 hpfs_free_sectors(s
, *ano
, 1);
428 a
->magic
= ANODE_MAGIC
;
430 a
->btree
.n_free_nodes
= 40;
431 a
->btree
.n_used_nodes
= 0;
432 a
->btree
.first_free
= 8;