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
 16static 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	
 47int 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
 62static 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
150secno 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
218static 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
236int 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
254void 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
297int 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
343void 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
365struct 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
391struct 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
408struct 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}

  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
 16static int chk_if_allocated(struct super_block *s, secno sec, char *msg)
 17{
 18	struct quad_buffer_head qbh;
 19	__le32 *bmp;
 20	if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "chk"))) goto fail;
 21	if ((le32_to_cpu(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	
 47int 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
 62static secno alloc_in_bmp(struct super_block *s, secno near, unsigned n, unsigned forward)
 63{
 64	struct quad_buffer_head qbh;
 65	__le32 *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
150secno 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
218static 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
236int hpfs_alloc_if_possible(struct super_block *s, secno sec)
237{
238	struct quad_buffer_head qbh;
239	__le32 *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
254void hpfs_free_sectors(struct super_block *s, secno sec, unsigned n)
255{
256	struct quad_buffer_head qbh;
257	__le32 *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
297int 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	__le32 *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
343void 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		__le32 *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
365struct 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
391struct 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
408struct 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}