1 /*
2 * linux/fs/hpfs/alloc.c
3 *
4 * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
5 *
6 * HPFS bitmap operations
7 */
8
9 #include "hpfs_fn.h"
10
11 /*
12 * Check if a sector is allocated in bitmap
13 * This is really slow. Turned on only if chk==2
14 */
15
chk_if_allocated(struct super_block * s,secno sec,char * msg)16 static int chk_if_allocated(struct super_block *s, secno sec, char *msg)
17 {
18 struct quad_buffer_head qbh;
19 u32 *bmp;
20 if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "chk"))) goto fail;
21 if ((cpu_to_le32(bmp[(sec & 0x3fff) >> 5]) >> (sec & 0x1f)) & 1) {
22 hpfs_error(s, "sector '%s' - %08x not allocated in bitmap", msg, sec);
23 goto fail1;
24 }
25 hpfs_brelse4(&qbh);
26 if (sec >= hpfs_sb(s)->sb_dirband_start && sec < hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) {
27 unsigned ssec = (sec - hpfs_sb(s)->sb_dirband_start) / 4;
28 if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto fail;
29 if ((le32_to_cpu(bmp[ssec >> 5]) >> (ssec & 0x1f)) & 1) {
30 hpfs_error(s, "sector '%s' - %08x not allocated in directory bitmap", msg, sec);
31 goto fail1;
32 }
33 hpfs_brelse4(&qbh);
34 }
35 return 0;
36 fail1:
37 hpfs_brelse4(&qbh);
38 fail:
39 return 1;
40 }
41
42 /*
43 * Check if sector(s) have proper number and additionally check if they're
44 * allocated in bitmap.
45 */
46
hpfs_chk_sectors(struct super_block * s,secno start,int len,char * msg)47 int hpfs_chk_sectors(struct super_block *s, secno start, int len, char *msg)
48 {
49 if (start + len < start || start < 0x12 ||
50 start + len > hpfs_sb(s)->sb_fs_size) {
51 hpfs_error(s, "sector(s) '%s' badly placed at %08x", msg, start);
52 return 1;
53 }
54 if (hpfs_sb(s)->sb_chk>=2) {
55 int i;
56 for (i = 0; i < len; i++)
57 if (chk_if_allocated(s, start + i, msg)) return 1;
58 }
59 return 0;
60 }
61
alloc_in_bmp(struct super_block * s,secno near,unsigned n,unsigned forward)62 static secno alloc_in_bmp(struct super_block *s, secno near, unsigned n, unsigned forward)
63 {
64 struct quad_buffer_head qbh;
65 unsigned *bmp;
66 unsigned bs = near & ~0x3fff;
67 unsigned nr = (near & 0x3fff) & ~(n - 1);
68 /*unsigned mnr;*/
69 unsigned i, q;
70 int a, b;
71 secno ret = 0;
72 if (n != 1 && n != 4) {
73 hpfs_error(s, "Bad allocation size: %d", n);
74 return 0;
75 }
76 if (bs != ~0x3fff) {
77 if (!(bmp = hpfs_map_bitmap(s, near >> 14, &qbh, "aib"))) goto uls;
78 } else {
79 if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto uls;
80 }
81 if (!tstbits(bmp, nr, n + forward)) {
82 ret = bs + nr;
83 goto rt;
84 }
85 q = nr + n; b = 0;
86 while ((a = tstbits(bmp, q, n + forward)) != 0) {
87 q += a;
88 if (n != 1) q = ((q-1)&~(n-1))+n;
89 if (!b) {
90 if (q>>5 != nr>>5) {
91 b = 1;
92 q = nr & 0x1f;
93 }
94 } else if (q > nr) break;
95 }
96 if (!a) {
97 ret = bs + q;
98 goto rt;
99 }
100 nr >>= 5;
101 /*for (i = nr + 1; i != nr; i++, i &= 0x1ff) */
102 i = nr;
103 do {
104 if (!le32_to_cpu(bmp[i])) goto cont;
105 if (n + forward >= 0x3f && le32_to_cpu(bmp[i]) != 0xffffffff) goto cont;
106 q = i<<5;
107 if (i > 0) {
108 unsigned k = le32_to_cpu(bmp[i-1]);
109 while (k & 0x80000000) {
110 q--; k <<= 1;
111 }
112 }
113 if (n != 1) q = ((q-1)&~(n-1))+n;
114 while ((a = tstbits(bmp, q, n + forward)) != 0) {
115 q += a;
116 if (n != 1) q = ((q-1)&~(n-1))+n;
117 if (q>>5 > i) break;
118 }
119 if (!a) {
120 ret = bs + q;
121 goto rt;
122 }
123 cont:
124 i++, i &= 0x1ff;
125 } while (i != nr);
126 rt:
127 if (ret) {
128 if (hpfs_sb(s)->sb_chk && ((ret >> 14) != (bs >> 14) || (le32_to_cpu(bmp[(ret & 0x3fff) >> 5]) | ~(((1 << n) - 1) << (ret & 0x1f))) != 0xffffffff)) {
129 hpfs_error(s, "Allocation doesn't work! Wanted %d, allocated at %08x", n, ret);
130 ret = 0;
131 goto b;
132 }
133 bmp[(ret & 0x3fff) >> 5] &= cpu_to_le32(~(((1 << n) - 1) << (ret & 0x1f)));
134 hpfs_mark_4buffers_dirty(&qbh);
135 }
136 b:
137 hpfs_brelse4(&qbh);
138 uls:
139 return ret;
140 }
141
142 /*
143 * Allocation strategy: 1) search place near the sector specified
144 * 2) search bitmap where free sectors last found
145 * 3) search all bitmaps
146 * 4) search all bitmaps ignoring number of pre-allocated
147 * sectors
148 */
149
hpfs_alloc_sector(struct super_block * s,secno near,unsigned n,int forward)150 secno hpfs_alloc_sector(struct super_block *s, secno near, unsigned n, int forward)
151 {
152 secno sec;
153 int i;
154 unsigned n_bmps;
155 struct hpfs_sb_info *sbi = hpfs_sb(s);
156 int f_p = 0;
157 int near_bmp;
158 if (forward < 0) {
159 forward = -forward;
160 f_p = 1;
161 }
162 n_bmps = (sbi->sb_fs_size + 0x4000 - 1) >> 14;
163 if (near && near < sbi->sb_fs_size) {
164 if ((sec = alloc_in_bmp(s, near, n, f_p ? forward : forward/4))) goto ret;
165 near_bmp = near >> 14;
166 } else near_bmp = n_bmps / 2;
167 /*
168 if (b != -1) {
169 if ((sec = alloc_in_bmp(s, b<<14, n, f_p ? forward : forward/2))) {
170 b &= 0x0fffffff;
171 goto ret;
172 }
173 if (b > 0x10000000) if ((sec = alloc_in_bmp(s, (b&0xfffffff)<<14, n, f_p ? forward : 0))) goto ret;
174 */
175 if (!f_p) if (forward > sbi->sb_max_fwd_alloc) forward = sbi->sb_max_fwd_alloc;
176 less_fwd:
177 for (i = 0; i < n_bmps; i++) {
178 if (near_bmp+i < n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i) << 14, n, forward)))) {
179 sbi->sb_c_bitmap = near_bmp+i;
180 goto ret;
181 }
182 if (!forward) {
183 if (near_bmp-i-1 >= 0 && ((sec = alloc_in_bmp(s, (near_bmp-i-1) << 14, n, forward)))) {
184 sbi->sb_c_bitmap = near_bmp-i-1;
185 goto ret;
186 }
187 } else {
188 if (near_bmp+i >= n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i-n_bmps) << 14, n, forward)))) {
189 sbi->sb_c_bitmap = near_bmp+i-n_bmps;
190 goto ret;
191 }
192 }
193 if (i == 1 && sbi->sb_c_bitmap != -1 && ((sec = alloc_in_bmp(s, (sbi->sb_c_bitmap) << 14, n, forward)))) {
194 goto ret;
195 }
196 }
197 if (!f_p) {
198 if (forward) {
199 sbi->sb_max_fwd_alloc = forward * 3 / 4;
200 forward /= 2;
201 goto less_fwd;
202 }
203 }
204 sec = 0;
205 ret:
206 if (sec && f_p) {
207 for (i = 0; i < forward; i++) {
208 if (!hpfs_alloc_if_possible(s, sec + i + 1)) {
209 hpfs_error(s, "Prealloc doesn't work! Wanted %d, allocated at %08x, can't allocate %d", forward, sec, i);
210 sec = 0;
211 break;
212 }
213 }
214 }
215 return sec;
216 }
217
alloc_in_dirband(struct super_block * s,secno near)218 static secno alloc_in_dirband(struct super_block *s, secno near)
219 {
220 unsigned nr = near;
221 secno sec;
222 struct hpfs_sb_info *sbi = hpfs_sb(s);
223 if (nr < sbi->sb_dirband_start)
224 nr = sbi->sb_dirband_start;
225 if (nr >= sbi->sb_dirband_start + sbi->sb_dirband_size)
226 nr = sbi->sb_dirband_start + sbi->sb_dirband_size - 4;
227 nr -= sbi->sb_dirband_start;
228 nr >>= 2;
229 sec = alloc_in_bmp(s, (~0x3fff) | nr, 1, 0);
230 if (!sec) return 0;
231 return ((sec & 0x3fff) << 2) + sbi->sb_dirband_start;
232 }
233
234 /* Alloc sector if it's free */
235
hpfs_alloc_if_possible(struct super_block * s,secno sec)236 int hpfs_alloc_if_possible(struct super_block *s, secno sec)
237 {
238 struct quad_buffer_head qbh;
239 u32 *bmp;
240 if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "aip"))) goto end;
241 if (le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) & (1 << (sec & 0x1f))) {
242 bmp[(sec & 0x3fff) >> 5] &= cpu_to_le32(~(1 << (sec & 0x1f)));
243 hpfs_mark_4buffers_dirty(&qbh);
244 hpfs_brelse4(&qbh);
245 return 1;
246 }
247 hpfs_brelse4(&qbh);
248 end:
249 return 0;
250 }
251
252 /* Free sectors in bitmaps */
253
hpfs_free_sectors(struct super_block * s,secno sec,unsigned n)254 void hpfs_free_sectors(struct super_block *s, secno sec, unsigned n)
255 {
256 struct quad_buffer_head qbh;
257 u32 *bmp;
258 struct hpfs_sb_info *sbi = hpfs_sb(s);
259 /*printk("2 - ");*/
260 if (!n) return;
261 if (sec < 0x12) {
262 hpfs_error(s, "Trying to free reserved sector %08x", sec);
263 return;
264 }
265 sbi->sb_max_fwd_alloc += n > 0xffff ? 0xffff : n;
266 if (sbi->sb_max_fwd_alloc > 0xffffff) sbi->sb_max_fwd_alloc = 0xffffff;
267 new_map:
268 if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "free"))) {
269 return;
270 }
271 new_tst:
272 if ((le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) >> (sec & 0x1f) & 1)) {
273 hpfs_error(s, "sector %08x not allocated", sec);
274 hpfs_brelse4(&qbh);
275 return;
276 }
277 bmp[(sec & 0x3fff) >> 5] |= cpu_to_le32(1 << (sec & 0x1f));
278 if (!--n) {
279 hpfs_mark_4buffers_dirty(&qbh);
280 hpfs_brelse4(&qbh);
281 return;
282 }
283 if (!(++sec & 0x3fff)) {
284 hpfs_mark_4buffers_dirty(&qbh);
285 hpfs_brelse4(&qbh);
286 goto new_map;
287 }
288 goto new_tst;
289 }
290
291 /*
292 * Check if there are at least n free dnodes on the filesystem.
293 * Called before adding to dnode. If we run out of space while
294 * splitting dnodes, it would corrupt dnode tree.
295 */
296
hpfs_check_free_dnodes(struct super_block * s,int n)297 int hpfs_check_free_dnodes(struct super_block *s, int n)
298 {
299 int n_bmps = (hpfs_sb(s)->sb_fs_size + 0x4000 - 1) >> 14;
300 int b = hpfs_sb(s)->sb_c_bitmap & 0x0fffffff;
301 int i, j;
302 u32 *bmp;
303 struct quad_buffer_head qbh;
304 if ((bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
305 for (j = 0; j < 512; j++) {
306 unsigned k;
307 if (!le32_to_cpu(bmp[j])) continue;
308 for (k = le32_to_cpu(bmp[j]); k; k >>= 1) if (k & 1) if (!--n) {
309 hpfs_brelse4(&qbh);
310 return 0;
311 }
312 }
313 }
314 hpfs_brelse4(&qbh);
315 i = 0;
316 if (hpfs_sb(s)->sb_c_bitmap != -1) {
317 bmp = hpfs_map_bitmap(s, b, &qbh, "chkdn1");
318 goto chk_bmp;
319 }
320 chk_next:
321 if (i == b) i++;
322 if (i >= n_bmps) return 1;
323 bmp = hpfs_map_bitmap(s, i, &qbh, "chkdn2");
324 chk_bmp:
325 if (bmp) {
326 for (j = 0; j < 512; j++) {
327 u32 k;
328 if (!le32_to_cpu(bmp[j])) continue;
329 for (k = 0xf; k; k <<= 4)
330 if ((le32_to_cpu(bmp[j]) & k) == k) {
331 if (!--n) {
332 hpfs_brelse4(&qbh);
333 return 0;
334 }
335 }
336 }
337 hpfs_brelse4(&qbh);
338 }
339 i++;
340 goto chk_next;
341 }
342
hpfs_free_dnode(struct super_block * s,dnode_secno dno)343 void hpfs_free_dnode(struct super_block *s, dnode_secno dno)
344 {
345 if (hpfs_sb(s)->sb_chk) if (dno & 3) {
346 hpfs_error(s, "hpfs_free_dnode: dnode %08x not aligned", dno);
347 return;
348 }
349 if (dno < hpfs_sb(s)->sb_dirband_start ||
350 dno >= hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) {
351 hpfs_free_sectors(s, dno, 4);
352 } else {
353 struct quad_buffer_head qbh;
354 u32 *bmp;
355 unsigned ssec = (dno - hpfs_sb(s)->sb_dirband_start) / 4;
356 if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
357 return;
358 }
359 bmp[ssec >> 5] |= cpu_to_le32(1 << (ssec & 0x1f));
360 hpfs_mark_4buffers_dirty(&qbh);
361 hpfs_brelse4(&qbh);
362 }
363 }
364
hpfs_alloc_dnode(struct super_block * s,secno near,dnode_secno * dno,struct quad_buffer_head * qbh)365 struct dnode *hpfs_alloc_dnode(struct super_block *s, secno near,
366 dnode_secno *dno, struct quad_buffer_head *qbh)
367 {
368 struct dnode *d;
369 if (hpfs_count_one_bitmap(s, hpfs_sb(s)->sb_dmap) > FREE_DNODES_ADD) {
370 if (!(*dno = alloc_in_dirband(s, near)))
371 if (!(*dno = hpfs_alloc_sector(s, near, 4, 0))) return NULL;
372 } else {
373 if (!(*dno = hpfs_alloc_sector(s, near, 4, 0)))
374 if (!(*dno = alloc_in_dirband(s, near))) return NULL;
375 }
376 if (!(d = hpfs_get_4sectors(s, *dno, qbh))) {
377 hpfs_free_dnode(s, *dno);
378 return NULL;
379 }
380 memset(d, 0, 2048);
381 d->magic = cpu_to_le32(DNODE_MAGIC);
382 d->first_free = cpu_to_le32(52);
383 d->dirent[0] = 32;
384 d->dirent[2] = 8;
385 d->dirent[30] = 1;
386 d->dirent[31] = 255;
387 d->self = cpu_to_le32(*dno);
388 return d;
389 }
390
hpfs_alloc_fnode(struct super_block * s,secno near,fnode_secno * fno,struct buffer_head ** bh)391 struct fnode *hpfs_alloc_fnode(struct super_block *s, secno near, fnode_secno *fno,
392 struct buffer_head **bh)
393 {
394 struct fnode *f;
395 if (!(*fno = hpfs_alloc_sector(s, near, 1, FNODE_ALLOC_FWD))) return NULL;
396 if (!(f = hpfs_get_sector(s, *fno, bh))) {
397 hpfs_free_sectors(s, *fno, 1);
398 return NULL;
399 }
400 memset(f, 0, 512);
401 f->magic = cpu_to_le32(FNODE_MAGIC);
402 f->ea_offs = cpu_to_le16(0xc4);
403 f->btree.n_free_nodes = 8;
404 f->btree.first_free = cpu_to_le16(8);
405 return f;
406 }
407
hpfs_alloc_anode(struct super_block * s,secno near,anode_secno * ano,struct buffer_head ** bh)408 struct anode *hpfs_alloc_anode(struct super_block *s, secno near, anode_secno *ano,
409 struct buffer_head **bh)
410 {
411 struct anode *a;
412 if (!(*ano = hpfs_alloc_sector(s, near, 1, ANODE_ALLOC_FWD))) return NULL;
413 if (!(a = hpfs_get_sector(s, *ano, bh))) {
414 hpfs_free_sectors(s, *ano, 1);
415 return NULL;
416 }
417 memset(a, 0, 512);
418 a->magic = cpu_to_le32(ANODE_MAGIC);
419 a->self = cpu_to_le32(*ano);
420 a->btree.n_free_nodes = 40;
421 a->btree.n_used_nodes = 0;
422 a->btree.first_free = cpu_to_le16(8);
423 return a;
424 }
425