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 >= 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 ((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 > hpfs_sb(s)->sb_fs_size) {
51 hpfs_error(s, "sector(s) '%s' badly placed at %08x", msg, start);
54 if (hpfs_sb(s)->sb_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 + forward)) {
86 /*if (!tstbits(bmp, nr + n, n + forward)) {
91 while ((a = tstbits(bmp, q, n + forward)) != 0) {
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) {*/
109 if (!bmp[i]) goto cont;
110 if (n + forward >= 0x3f && bmp[i] != -1) goto cont;
113 unsigned k = bmp[i-1];
114 while (k & 0x80000000) {
118 if (n != 1) q = ((q-1)&~(n-1))+n;
119 while ((a = tstbits(bmp, q, n + forward)) != 0) {
121 if (n != 1) q = ((q-1)&~(n-1))+n;
133 if (hpfs_sb(s)->sb_chk && ((ret >> 14) != (bs >> 14) || (bmp[(ret & 0x3fff) >> 5] | ~(((1 << n) - 1) << (ret & 0x1f))) != 0xffffffff)) {
134 hpfs_error(s, "Allocation doesn't work! Wanted %d, allocated at %08x", n, ret);
138 bmp[(ret & 0x3fff) >> 5] &= ~(((1 << n) - 1) << (ret & 0x1f));
139 hpfs_mark_4buffers_dirty(&qbh);
149 * Allocation strategy: 1) search place near the sector specified
150 * 2) search bitmap where free sectors last found
151 * 3) search all bitmaps
152 * 4) search all bitmaps ignoring number of pre-allocated
156 secno hpfs_alloc_sector(struct super_block *s, secno near, unsigned n, int forward, int lock)
161 struct hpfs_sb_info *sbi = hpfs_sb(s);
168 if (lock) hpfs_lock_creation(s);
169 n_bmps = (sbi->sb_fs_size + 0x4000 - 1) >> 14;
170 if (near && near < sbi->sb_fs_size) {
171 if ((sec = alloc_in_bmp(s, near, n, f_p ? forward : forward/4))) goto ret;
172 near_bmp = near >> 14;
173 } else near_bmp = n_bmps / 2;
176 if ((sec = alloc_in_bmp(s, b<<14, n, f_p ? forward : forward/2))) {
180 if (b > 0x10000000) if ((sec = alloc_in_bmp(s, (b&0xfffffff)<<14, n, f_p ? forward : 0))) goto ret;
182 if (!f_p) if (forward > sbi->sb_max_fwd_alloc) forward = sbi->sb_max_fwd_alloc;
184 for (i = 0; i < n_bmps; i++) {
185 if (near_bmp+i < n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i) << 14, n, forward)))) {
186 sbi->sb_c_bitmap = near_bmp+i;
190 if (near_bmp-i-1 >= 0 && ((sec = alloc_in_bmp(s, (near_bmp-i-1) << 14, n, forward)))) {
191 sbi->sb_c_bitmap = near_bmp-i-1;
195 if (near_bmp+i >= n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i-n_bmps) << 14, n, forward)))) {
196 sbi->sb_c_bitmap = near_bmp+i-n_bmps;
200 if (i == 1 && sbi->sb_c_bitmap != -1 && ((sec = alloc_in_bmp(s, (sbi->sb_c_bitmap) << 14, n, forward)))) {
206 sbi->sb_max_fwd_alloc = forward * 3 / 4;
214 for (i = 0; i < forward; i++) {
215 if (!hpfs_alloc_if_possible_nolock(s, sec + i + 1)) {
216 hpfs_error(s, "Prealloc doesn't work! Wanted %d, allocated at %08x, can't allocate %d", forward, sec, i);
222 if (lock) hpfs_unlock_creation(s);
226 static secno alloc_in_dirband(struct super_block *s, secno near, int lock)
230 struct hpfs_sb_info *sbi = hpfs_sb(s);
231 if (nr < sbi->sb_dirband_start)
232 nr = sbi->sb_dirband_start;
233 if (nr >= sbi->sb_dirband_start + sbi->sb_dirband_size)
234 nr = sbi->sb_dirband_start + sbi->sb_dirband_size - 4;
235 nr -= sbi->sb_dirband_start;
237 if (lock) hpfs_lock_creation(s);
238 sec = alloc_in_bmp(s, (~0x3fff) | nr, 1, 0);
239 if (lock) hpfs_unlock_creation(s);
241 return ((sec & 0x3fff) << 2) + sbi->sb_dirband_start;
244 /* Alloc sector if it's free */
246 int hpfs_alloc_if_possible_nolock(struct super_block *s, secno sec)
248 struct quad_buffer_head qbh;
251 if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "aip"))) goto end;
252 if (bmp[(sec & 0x3fff) >> 5] & (1 << (sec & 0x1f))) {
253 bmp[(sec & 0x3fff) >> 5] &= ~(1 << (sec & 0x1f));
254 hpfs_mark_4buffers_dirty(&qbh);
265 int hpfs_alloc_if_possible(struct super_block *s, secno sec)
268 hpfs_lock_creation(s);
269 r = hpfs_alloc_if_possible_nolock(s, sec);
270 hpfs_unlock_creation(s);
274 /* Free sectors in bitmaps */
276 void hpfs_free_sectors(struct super_block *s, secno sec, unsigned n)
278 struct quad_buffer_head qbh;
280 struct hpfs_sb_info *sbi = hpfs_sb(s);
284 hpfs_error(s, "Trying to free reserved sector %08x", sec);
288 sbi->sb_max_fwd_alloc += n > 0xffff ? 0xffff : n;
289 if (sbi->sb_max_fwd_alloc > 0xffffff) sbi->sb_max_fwd_alloc = 0xffffff;
291 if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "free"))) {
296 if ((bmp[(sec & 0x3fff) >> 5] >> (sec & 0x1f) & 1)) {
297 hpfs_error(s, "sector %08x not allocated", sec);
302 bmp[(sec & 0x3fff) >> 5] |= 1 << (sec & 0x1f);
304 hpfs_mark_4buffers_dirty(&qbh);
309 if (!(++sec & 0x3fff)) {
310 hpfs_mark_4buffers_dirty(&qbh);
318 * Check if there are at least n free dnodes on the filesystem.
319 * Called before adding to dnode. If we run out of space while
320 * splitting dnodes, it would corrupt dnode tree.
323 int hpfs_check_free_dnodes(struct super_block *s, int n)
325 int n_bmps = (hpfs_sb(s)->sb_fs_size + 0x4000 - 1) >> 14;
326 int b = hpfs_sb(s)->sb_c_bitmap & 0x0fffffff;
329 struct quad_buffer_head qbh;
330 if ((bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
331 for (j = 0; j < 512; j++) {
333 if (!bmp[j]) continue;
334 for (k = bmp[j]; k; k >>= 1) if (k & 1) if (!--n) {
342 if (hpfs_sb(s)->sb_c_bitmap != -1) {
343 bmp = hpfs_map_bitmap(s, b, &qbh, "chkdn1");
348 if (i >= n_bmps) return 1;
349 bmp = hpfs_map_bitmap(s, i, &qbh, "chkdn2");
352 for (j = 0; j < 512; j++) {
354 if (!bmp[j]) continue;
355 for (k = 0xf; k; k <<= 4)
356 if ((bmp[j] & k) == k) {
369 void hpfs_free_dnode(struct super_block *s, dnode_secno dno)
371 if (hpfs_sb(s)->sb_chk) if (dno & 3) {
372 hpfs_error(s, "hpfs_free_dnode: dnode %08x not aligned", dno);
375 if (dno < hpfs_sb(s)->sb_dirband_start ||
376 dno >= hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) {
377 hpfs_free_sectors(s, dno, 4);
379 struct quad_buffer_head qbh;
381 unsigned ssec = (dno - hpfs_sb(s)->sb_dirband_start) / 4;
383 if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
387 bmp[ssec >> 5] |= 1 << (ssec & 0x1f);
388 hpfs_mark_4buffers_dirty(&qbh);
394 struct dnode *hpfs_alloc_dnode(struct super_block *s, secno near,
395 dnode_secno *dno, struct quad_buffer_head *qbh,
399 if (hpfs_count_one_bitmap(s, hpfs_sb(s)->sb_dmap) > FREE_DNODES_ADD) {
400 if (!(*dno = alloc_in_dirband(s, near, lock)))
401 if (!(*dno = hpfs_alloc_sector(s, near, 4, 0, lock))) return NULL;
403 if (!(*dno = hpfs_alloc_sector(s, near, 4, 0, lock)))
404 if (!(*dno = alloc_in_dirband(s, near, lock))) return NULL;
406 if (!(d = hpfs_get_4sectors(s, *dno, qbh))) {
407 hpfs_free_dnode(s, *dno);
411 d->magic = DNODE_MAGIC;
421 struct fnode *hpfs_alloc_fnode(struct super_block *s, secno near, fnode_secno *fno,
422 struct buffer_head **bh)
425 if (!(*fno = hpfs_alloc_sector(s, near, 1, FNODE_ALLOC_FWD, 1))) return NULL;
426 if (!(f = hpfs_get_sector(s, *fno, bh))) {
427 hpfs_free_sectors(s, *fno, 1);
431 f->magic = FNODE_MAGIC;
433 f->btree.n_free_nodes = 8;
434 f->btree.first_free = 8;
438 struct anode *hpfs_alloc_anode(struct super_block *s, secno near, anode_secno *ano,
439 struct buffer_head **bh)
442 if (!(*ano = hpfs_alloc_sector(s, near, 1, ANODE_ALLOC_FWD, 1))) return NULL;
443 if (!(a = hpfs_get_sector(s, *ano, bh))) {
444 hpfs_free_sectors(s, *ano, 1);
448 a->magic = ANODE_MAGIC;
450 a->btree.n_free_nodes = 40;
451 a->btree.n_used_nodes = 0;
452 a->btree.first_free = 8;