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;