1/*
2 *  linux/fs/ufs/balloc.c
3 *
4 * Copyright (C) 1998
5 * Daniel Pirkl <daniel.pirkl@email.cz>
6 * Charles University, Faculty of Mathematics and Physics
7 *
8 * UFS2 write support Evgeniy Dushistov <dushistov@mail.ru>, 2007
9 */
10
11#include <linux/fs.h>
12#include <linux/stat.h>
13#include <linux/time.h>
14#include <linux/string.h>
15#include <linux/buffer_head.h>
16#include <linux/capability.h>
17#include <linux/bitops.h>
18#include <asm/byteorder.h>
19
20#include "ufs_fs.h"
21#include "ufs.h"
22#include "swab.h"
23#include "util.h"
24
25#define INVBLOCK ((u64)-1L)
26
27static u64 ufs_add_fragments(struct inode *, u64, unsigned, unsigned);
28static u64 ufs_alloc_fragments(struct inode *, unsigned, u64, unsigned, int *);
29static u64 ufs_alloccg_block(struct inode *, struct ufs_cg_private_info *, u64, int *);
30static u64 ufs_bitmap_search (struct super_block *, struct ufs_cg_private_info *, u64, unsigned);
31static unsigned char ufs_fragtable_8fpb[], ufs_fragtable_other[];
32static void ufs_clusteracct(struct super_block *, struct ufs_cg_private_info *, unsigned, int);
33
34/*
35 * Free 'count' fragments from fragment number 'fragment'
36 */
37void ufs_free_fragments(struct inode *inode, u64 fragment, unsigned count)
38{
39	struct super_block * sb;
40	struct ufs_sb_private_info * uspi;
41	struct ufs_cg_private_info * ucpi;
42	struct ufs_cylinder_group * ucg;
43	unsigned cgno, bit, end_bit, bbase, blkmap, i;
44	u64 blkno;
45
46	sb = inode->i_sb;
47	uspi = UFS_SB(sb)->s_uspi;
48
49	UFSD("ENTER, fragment %llu, count %u\n",
50	     (unsigned long long)fragment, count);
51
52	if (ufs_fragnum(fragment) + count > uspi->s_fpg)
53		ufs_error (sb, "ufs_free_fragments", "internal error");
54
55	mutex_lock(&UFS_SB(sb)->s_lock);
56
57	cgno = ufs_dtog(uspi, fragment);
58	bit = ufs_dtogd(uspi, fragment);
59	if (cgno >= uspi->s_ncg) {
60		ufs_panic (sb, "ufs_free_fragments", "freeing blocks are outside device");
61		goto failed;
62	}
63
64	ucpi = ufs_load_cylinder (sb, cgno);
65	if (!ucpi)
66		goto failed;
67	ucg = ubh_get_ucg (UCPI_UBH(ucpi));
68	if (!ufs_cg_chkmagic(sb, ucg)) {
69		ufs_panic (sb, "ufs_free_fragments", "internal error, bad magic number on cg %u", cgno);
70		goto failed;
71	}
72
73	end_bit = bit + count;
74	bbase = ufs_blknum (bit);
75	blkmap = ubh_blkmap (UCPI_UBH(ucpi), ucpi->c_freeoff, bbase);
76	ufs_fragacct (sb, blkmap, ucg->cg_frsum, -1);
77	for (i = bit; i < end_bit; i++) {
78		if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_freeoff, i))
79			ubh_setbit (UCPI_UBH(ucpi), ucpi->c_freeoff, i);
80		else
81			ufs_error (sb, "ufs_free_fragments",
82				   "bit already cleared for fragment %u", i);
83	}
84
85	fs32_add(sb, &ucg->cg_cs.cs_nffree, count);
86	uspi->cs_total.cs_nffree += count;
87	fs32_add(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, count);
88	blkmap = ubh_blkmap (UCPI_UBH(ucpi), ucpi->c_freeoff, bbase);
89	ufs_fragacct(sb, blkmap, ucg->cg_frsum, 1);
90
91	/*
92	 * Trying to reassemble free fragments into block
93	 */
94	blkno = ufs_fragstoblks (bbase);
95	if (ubh_isblockset(UCPI_UBH(ucpi), ucpi->c_freeoff, blkno)) {
96		fs32_sub(sb, &ucg->cg_cs.cs_nffree, uspi->s_fpb);
97		uspi->cs_total.cs_nffree -= uspi->s_fpb;
98		fs32_sub(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, uspi->s_fpb);
99		if ((UFS_SB(sb)->s_flags & UFS_CG_MASK) == UFS_CG_44BSD)
100			ufs_clusteracct (sb, ucpi, blkno, 1);
101		fs32_add(sb, &ucg->cg_cs.cs_nbfree, 1);
102		uspi->cs_total.cs_nbfree++;
103		fs32_add(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nbfree, 1);
104		if (uspi->fs_magic != UFS2_MAGIC) {
105			unsigned cylno = ufs_cbtocylno (bbase);
106
107			fs16_add(sb, &ubh_cg_blks(ucpi, cylno,
108						  ufs_cbtorpos(bbase)), 1);
109			fs32_add(sb, &ubh_cg_blktot(ucpi, cylno), 1);
110		}
111	}
112
113	ubh_mark_buffer_dirty (USPI_UBH(uspi));
114	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
115	if (sb->s_flags & MS_SYNCHRONOUS)
116		ubh_sync_block(UCPI_UBH(ucpi));
117	ufs_mark_sb_dirty(sb);
118
119	mutex_unlock(&UFS_SB(sb)->s_lock);
120	UFSD("EXIT\n");
121	return;
122
123failed:
124	mutex_unlock(&UFS_SB(sb)->s_lock);
125	UFSD("EXIT (FAILED)\n");
126	return;
127}
128
129/*
130 * Free 'count' fragments from fragment number 'fragment' (free whole blocks)
131 */
132void ufs_free_blocks(struct inode *inode, u64 fragment, unsigned count)
133{
134	struct super_block * sb;
135	struct ufs_sb_private_info * uspi;
136	struct ufs_cg_private_info * ucpi;
137	struct ufs_cylinder_group * ucg;
138	unsigned overflow, cgno, bit, end_bit, i;
139	u64 blkno;
140
141	sb = inode->i_sb;
142	uspi = UFS_SB(sb)->s_uspi;
143
144	UFSD("ENTER, fragment %llu, count %u\n",
145	     (unsigned long long)fragment, count);
146
147	if ((fragment & uspi->s_fpbmask) || (count & uspi->s_fpbmask)) {
148		ufs_error (sb, "ufs_free_blocks", "internal error, "
149			   "fragment %llu, count %u\n",
150			   (unsigned long long)fragment, count);
151		goto failed;
152	}
153
154	mutex_lock(&UFS_SB(sb)->s_lock);
155
156do_more:
157	overflow = 0;
158	cgno = ufs_dtog(uspi, fragment);
159	bit = ufs_dtogd(uspi, fragment);
160	if (cgno >= uspi->s_ncg) {
161		ufs_panic (sb, "ufs_free_blocks", "freeing blocks are outside device");
162		goto failed_unlock;
163	}
164	end_bit = bit + count;
165	if (end_bit > uspi->s_fpg) {
166		overflow = bit + count - uspi->s_fpg;
167		count -= overflow;
168		end_bit -= overflow;
169	}
170
171	ucpi = ufs_load_cylinder (sb, cgno);
172	if (!ucpi)
173		goto failed_unlock;
174	ucg = ubh_get_ucg (UCPI_UBH(ucpi));
175	if (!ufs_cg_chkmagic(sb, ucg)) {
176		ufs_panic (sb, "ufs_free_blocks", "internal error, bad magic number on cg %u", cgno);
177		goto failed_unlock;
178	}
179
180	for (i = bit; i < end_bit; i += uspi->s_fpb) {
181		blkno = ufs_fragstoblks(i);
182		if (ubh_isblockset(UCPI_UBH(ucpi), ucpi->c_freeoff, blkno)) {
183			ufs_error(sb, "ufs_free_blocks", "freeing free fragment");
184		}
185		ubh_setblock(UCPI_UBH(ucpi), ucpi->c_freeoff, blkno);
186		if ((UFS_SB(sb)->s_flags & UFS_CG_MASK) == UFS_CG_44BSD)
187			ufs_clusteracct (sb, ucpi, blkno, 1);
188
189		fs32_add(sb, &ucg->cg_cs.cs_nbfree, 1);
190		uspi->cs_total.cs_nbfree++;
191		fs32_add(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nbfree, 1);
192
193		if (uspi->fs_magic != UFS2_MAGIC) {
194			unsigned cylno = ufs_cbtocylno(i);
195
196			fs16_add(sb, &ubh_cg_blks(ucpi, cylno,
197						  ufs_cbtorpos(i)), 1);
198			fs32_add(sb, &ubh_cg_blktot(ucpi, cylno), 1);
199		}
200	}
201
202	ubh_mark_buffer_dirty (USPI_UBH(uspi));
203	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
204	if (sb->s_flags & MS_SYNCHRONOUS)
205		ubh_sync_block(UCPI_UBH(ucpi));
206
207	if (overflow) {
208		fragment += count;
209		count = overflow;
210		goto do_more;
211	}
212
213	ufs_mark_sb_dirty(sb);
214	mutex_unlock(&UFS_SB(sb)->s_lock);
215	UFSD("EXIT\n");
216	return;
217
218failed_unlock:
219	mutex_unlock(&UFS_SB(sb)->s_lock);
220failed:
221	UFSD("EXIT (FAILED)\n");
222	return;
223}
224
225/*
226 * Modify inode page cache in such way:
227 * have - blocks with b_blocknr equal to oldb...oldb+count-1
228 * get - blocks with b_blocknr equal to newb...newb+count-1
229 * also we suppose that oldb...oldb+count-1 blocks
230 * situated at the end of file.
231 *
232 * We can come here from ufs_writepage or ufs_prepare_write,
233 * locked_page is argument of these functions, so we already lock it.
234 */
235static void ufs_change_blocknr(struct inode *inode, sector_t beg,
236			       unsigned int count, sector_t oldb,
237			       sector_t newb, struct page *locked_page)
238{
239	const unsigned blks_per_page =
240		1 << (PAGE_CACHE_SHIFT - inode->i_blkbits);
241	const unsigned mask = blks_per_page - 1;
242	struct address_space * const mapping = inode->i_mapping;
243	pgoff_t index, cur_index, last_index;
244	unsigned pos, j, lblock;
245	sector_t end, i;
246	struct page *page;
247	struct buffer_head *head, *bh;
248
249	UFSD("ENTER, ino %lu, count %u, oldb %llu, newb %llu\n",
250	      inode->i_ino, count,
251	     (unsigned long long)oldb, (unsigned long long)newb);
252
253	BUG_ON(!locked_page);
254	BUG_ON(!PageLocked(locked_page));
255
256	cur_index = locked_page->index;
257	end = count + beg;
258	last_index = end >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
259	for (i = beg; i < end; i = (i | mask) + 1) {
260		index = i >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
261
262		if (likely(cur_index != index)) {
263			page = ufs_get_locked_page(mapping, index);
264			if (!page)/* it was truncated */
265				continue;
266			if (IS_ERR(page)) {/* or EIO */
267				ufs_error(inode->i_sb, __func__,
268					  "read of page %llu failed\n",
269					  (unsigned long long)index);
270				continue;
271			}
272		} else
273			page = locked_page;
274
275		head = page_buffers(page);
276		bh = head;
277		pos = i & mask;
278		for (j = 0; j < pos; ++j)
279			bh = bh->b_this_page;
280
281
282		if (unlikely(index == last_index))
283			lblock = end & mask;
284		else
285			lblock = blks_per_page;
286
287		do {
288			if (j >= lblock)
289				break;
290			pos = (i - beg) + j;
291
292			if (!buffer_mapped(bh))
293					map_bh(bh, inode->i_sb, oldb + pos);
294			if (!buffer_uptodate(bh)) {
295				ll_rw_block(READ, 1, &bh);
296				wait_on_buffer(bh);
297				if (!buffer_uptodate(bh)) {
298					ufs_error(inode->i_sb, __func__,
299						  "read of block failed\n");
300					break;
301				}
302			}
303
304			UFSD(" change from %llu to %llu, pos %u\n",
305			     (unsigned long long)(pos + oldb),
306			     (unsigned long long)(pos + newb), pos);
307
308			bh->b_blocknr = newb + pos;
309			unmap_underlying_metadata(bh->b_bdev,
310						  bh->b_blocknr);
311			mark_buffer_dirty(bh);
312			++j;
313			bh = bh->b_this_page;
314		} while (bh != head);
315
316		if (likely(cur_index != index))
317			ufs_put_locked_page(page);
318 	}
319	UFSD("EXIT\n");
320}
321
322static void ufs_clear_frags(struct inode *inode, sector_t beg, unsigned int n,
323			    int sync)
324{
325	struct buffer_head *bh;
326	sector_t end = beg + n;
327
328	for (; beg < end; ++beg) {
329		bh = sb_getblk(inode->i_sb, beg);
330		lock_buffer(bh);
331		memset(bh->b_data, 0, inode->i_sb->s_blocksize);
332		set_buffer_uptodate(bh);
333		mark_buffer_dirty(bh);
334		unlock_buffer(bh);
335		if (IS_SYNC(inode) || sync)
336			sync_dirty_buffer(bh);
337		brelse(bh);
338	}
339}
340
341u64 ufs_new_fragments(struct inode *inode, void *p, u64 fragment,
342			   u64 goal, unsigned count, int *err,
343			   struct page *locked_page)
344{
345	struct super_block * sb;
346	struct ufs_sb_private_info * uspi;
347	struct ufs_super_block_first * usb1;
348	unsigned cgno, oldcount, newcount;
349	u64 tmp, request, result;
350
351	UFSD("ENTER, ino %lu, fragment %llu, goal %llu, count %u\n",
352	     inode->i_ino, (unsigned long long)fragment,
353	     (unsigned long long)goal, count);
354
355	sb = inode->i_sb;
356	uspi = UFS_SB(sb)->s_uspi;
357	usb1 = ubh_get_usb_first(uspi);
358	*err = -ENOSPC;
359
360	mutex_lock(&UFS_SB(sb)->s_lock);
361	tmp = ufs_data_ptr_to_cpu(sb, p);
362
363	if (count + ufs_fragnum(fragment) > uspi->s_fpb) {
364		ufs_warning(sb, "ufs_new_fragments", "internal warning"
365			    " fragment %llu, count %u",
366			    (unsigned long long)fragment, count);
367		count = uspi->s_fpb - ufs_fragnum(fragment);
368	}
369	oldcount = ufs_fragnum (fragment);
370	newcount = oldcount + count;
371
372	/*
373	 * Somebody else has just allocated our fragments
374	 */
375	if (oldcount) {
376		if (!tmp) {
377			ufs_error(sb, "ufs_new_fragments", "internal error, "
378				  "fragment %llu, tmp %llu\n",
379				  (unsigned long long)fragment,
380				  (unsigned long long)tmp);
381			mutex_unlock(&UFS_SB(sb)->s_lock);
382			return INVBLOCK;
383		}
384		if (fragment < UFS_I(inode)->i_lastfrag) {
385			UFSD("EXIT (ALREADY ALLOCATED)\n");
386			mutex_unlock(&UFS_SB(sb)->s_lock);
387			return 0;
388		}
389	}
390	else {
391		if (tmp) {
392			UFSD("EXIT (ALREADY ALLOCATED)\n");
393			mutex_unlock(&UFS_SB(sb)->s_lock);
394			return 0;
395		}
396	}
397
398	/*
399	 * There is not enough space for user on the device
400	 */
401	if (!capable(CAP_SYS_RESOURCE) && ufs_freespace(uspi, UFS_MINFREE) <= 0) {
402		mutex_unlock(&UFS_SB(sb)->s_lock);
403		UFSD("EXIT (FAILED)\n");
404		return 0;
405	}
406
407	if (goal >= uspi->s_size)
408		goal = 0;
409	if (goal == 0)
410		cgno = ufs_inotocg (inode->i_ino);
411	else
412		cgno = ufs_dtog(uspi, goal);
413
414	/*
415	 * allocate new fragment
416	 */
417	if (oldcount == 0) {
418		result = ufs_alloc_fragments (inode, cgno, goal, count, err);
419		if (result) {
420			ufs_cpu_to_data_ptr(sb, p, result);
421			*err = 0;
422			UFS_I(inode)->i_lastfrag =
423				max(UFS_I(inode)->i_lastfrag, fragment + count);
424			ufs_clear_frags(inode, result + oldcount,
425					newcount - oldcount, locked_page != NULL);
426		}
427		mutex_unlock(&UFS_SB(sb)->s_lock);
428		UFSD("EXIT, result %llu\n", (unsigned long long)result);
429		return result;
430	}
431
432	/*
433	 * resize block
434	 */
435	result = ufs_add_fragments(inode, tmp, oldcount, newcount);
436	if (result) {
437		*err = 0;
438		UFS_I(inode)->i_lastfrag = max(UFS_I(inode)->i_lastfrag,
439						fragment + count);
440		ufs_clear_frags(inode, result + oldcount, newcount - oldcount,
441				locked_page != NULL);
442		mutex_unlock(&UFS_SB(sb)->s_lock);
443		UFSD("EXIT, result %llu\n", (unsigned long long)result);
444		return result;
445	}
446
447	/*
448	 * allocate new block and move data
449	 */
450	switch (fs32_to_cpu(sb, usb1->fs_optim)) {
451	    case UFS_OPTSPACE:
452		request = newcount;
453		if (uspi->s_minfree < 5 || uspi->cs_total.cs_nffree
454		    > uspi->s_dsize * uspi->s_minfree / (2 * 100))
455			break;
456		usb1->fs_optim = cpu_to_fs32(sb, UFS_OPTTIME);
457		break;
458	    default:
459		usb1->fs_optim = cpu_to_fs32(sb, UFS_OPTTIME);
460
461	    case UFS_OPTTIME:
462		request = uspi->s_fpb;
463		if (uspi->cs_total.cs_nffree < uspi->s_dsize *
464		    (uspi->s_minfree - 2) / 100)
465			break;
466		usb1->fs_optim = cpu_to_fs32(sb, UFS_OPTTIME);
467		break;
468	}
469	result = ufs_alloc_fragments (inode, cgno, goal, request, err);
470	if (result) {
471		ufs_clear_frags(inode, result + oldcount, newcount - oldcount,
472				locked_page != NULL);
473		ufs_change_blocknr(inode, fragment - oldcount, oldcount,
474				   uspi->s_sbbase + tmp,
475				   uspi->s_sbbase + result, locked_page);
476		ufs_cpu_to_data_ptr(sb, p, result);
477		*err = 0;
478		UFS_I(inode)->i_lastfrag = max(UFS_I(inode)->i_lastfrag,
479						fragment + count);
480		mutex_unlock(&UFS_SB(sb)->s_lock);
481		if (newcount < request)
482			ufs_free_fragments (inode, result + newcount, request - newcount);
483		ufs_free_fragments (inode, tmp, oldcount);
484		UFSD("EXIT, result %llu\n", (unsigned long long)result);
485		return result;
486	}
487
488	mutex_unlock(&UFS_SB(sb)->s_lock);
489	UFSD("EXIT (FAILED)\n");
490	return 0;
491}
492
493static u64 ufs_add_fragments(struct inode *inode, u64 fragment,
494			     unsigned oldcount, unsigned newcount)
495{
496	struct super_block * sb;
497	struct ufs_sb_private_info * uspi;
498	struct ufs_cg_private_info * ucpi;
499	struct ufs_cylinder_group * ucg;
500	unsigned cgno, fragno, fragoff, count, fragsize, i;
501
502	UFSD("ENTER, fragment %llu, oldcount %u, newcount %u\n",
503	     (unsigned long long)fragment, oldcount, newcount);
504
505	sb = inode->i_sb;
506	uspi = UFS_SB(sb)->s_uspi;
507	count = newcount - oldcount;
508
509	cgno = ufs_dtog(uspi, fragment);
510	if (fs32_to_cpu(sb, UFS_SB(sb)->fs_cs(cgno).cs_nffree) < count)
511		return 0;
512	if ((ufs_fragnum (fragment) + newcount) > uspi->s_fpb)
513		return 0;
514	ucpi = ufs_load_cylinder (sb, cgno);
515	if (!ucpi)
516		return 0;
517	ucg = ubh_get_ucg (UCPI_UBH(ucpi));
518	if (!ufs_cg_chkmagic(sb, ucg)) {
519		ufs_panic (sb, "ufs_add_fragments",
520			"internal error, bad magic number on cg %u", cgno);
521		return 0;
522	}
523
524	fragno = ufs_dtogd(uspi, fragment);
525	fragoff = ufs_fragnum (fragno);
526	for (i = oldcount; i < newcount; i++)
527		if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_freeoff, fragno + i))
528			return 0;
529	/*
530	 * Block can be extended
531	 */
532	ucg->cg_time = cpu_to_fs32(sb, get_seconds());
533	for (i = newcount; i < (uspi->s_fpb - fragoff); i++)
534		if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_freeoff, fragno + i))
535			break;
536	fragsize = i - oldcount;
537	if (!fs32_to_cpu(sb, ucg->cg_frsum[fragsize]))
538		ufs_panic (sb, "ufs_add_fragments",
539			"internal error or corrupted bitmap on cg %u", cgno);
540	fs32_sub(sb, &ucg->cg_frsum[fragsize], 1);
541	if (fragsize != count)
542		fs32_add(sb, &ucg->cg_frsum[fragsize - count], 1);
543	for (i = oldcount; i < newcount; i++)
544		ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_freeoff, fragno + i);
545
546	fs32_sub(sb, &ucg->cg_cs.cs_nffree, count);
547	fs32_sub(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, count);
548	uspi->cs_total.cs_nffree -= count;
549
550	ubh_mark_buffer_dirty (USPI_UBH(uspi));
551	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
552	if (sb->s_flags & MS_SYNCHRONOUS)
553		ubh_sync_block(UCPI_UBH(ucpi));
554	ufs_mark_sb_dirty(sb);
555
556	UFSD("EXIT, fragment %llu\n", (unsigned long long)fragment);
557
558	return fragment;
559}
560
561#define UFS_TEST_FREE_SPACE_CG \
562	ucg = (struct ufs_cylinder_group *) UFS_SB(sb)->s_ucg[cgno]->b_data; \
563	if (fs32_to_cpu(sb, ucg->cg_cs.cs_nbfree)) \
564		goto cg_found; \
565	for (k = count; k < uspi->s_fpb; k++) \
566		if (fs32_to_cpu(sb, ucg->cg_frsum[k])) \
567			goto cg_found;
568
569static u64 ufs_alloc_fragments(struct inode *inode, unsigned cgno,
570			       u64 goal, unsigned count, int *err)
571{
572	struct super_block * sb;
573	struct ufs_sb_private_info * uspi;
574	struct ufs_cg_private_info * ucpi;
575	struct ufs_cylinder_group * ucg;
576	unsigned oldcg, i, j, k, allocsize;
577	u64 result;
578
579	UFSD("ENTER, ino %lu, cgno %u, goal %llu, count %u\n",
580	     inode->i_ino, cgno, (unsigned long long)goal, count);
581
582	sb = inode->i_sb;
583	uspi = UFS_SB(sb)->s_uspi;
584	oldcg = cgno;
585
586	/*
587	 * 1. searching on preferred cylinder group
588	 */
589	UFS_TEST_FREE_SPACE_CG
590
591	/*
592	 * 2. quadratic rehash
593	 */
594	for (j = 1; j < uspi->s_ncg; j *= 2) {
595		cgno += j;
596		if (cgno >= uspi->s_ncg)
597			cgno -= uspi->s_ncg;
598		UFS_TEST_FREE_SPACE_CG
599	}
600
601	/*
602	 * 3. brute force search
603	 * We start at i = 2 ( 0 is checked at 1.step, 1 at 2.step )
604	 */
605	cgno = (oldcg + 1) % uspi->s_ncg;
606	for (j = 2; j < uspi->s_ncg; j++) {
607		cgno++;
608		if (cgno >= uspi->s_ncg)
609			cgno = 0;
610		UFS_TEST_FREE_SPACE_CG
611	}
612
613	UFSD("EXIT (FAILED)\n");
614	return 0;
615
616cg_found:
617	ucpi = ufs_load_cylinder (sb, cgno);
618	if (!ucpi)
619		return 0;
620	ucg = ubh_get_ucg (UCPI_UBH(ucpi));
621	if (!ufs_cg_chkmagic(sb, ucg))
622		ufs_panic (sb, "ufs_alloc_fragments",
623			"internal error, bad magic number on cg %u", cgno);
624	ucg->cg_time = cpu_to_fs32(sb, get_seconds());
625
626	if (count == uspi->s_fpb) {
627		result = ufs_alloccg_block (inode, ucpi, goal, err);
628		if (result == INVBLOCK)
629			return 0;
630		goto succed;
631	}
632
633	for (allocsize = count; allocsize < uspi->s_fpb; allocsize++)
634		if (fs32_to_cpu(sb, ucg->cg_frsum[allocsize]) != 0)
635			break;
636
637	if (allocsize == uspi->s_fpb) {
638		result = ufs_alloccg_block (inode, ucpi, goal, err);
639		if (result == INVBLOCK)
640			return 0;
641		goal = ufs_dtogd(uspi, result);
642		for (i = count; i < uspi->s_fpb; i++)
643			ubh_setbit (UCPI_UBH(ucpi), ucpi->c_freeoff, goal + i);
644		i = uspi->s_fpb - count;
645
646		fs32_add(sb, &ucg->cg_cs.cs_nffree, i);
647		uspi->cs_total.cs_nffree += i;
648		fs32_add(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, i);
649		fs32_add(sb, &ucg->cg_frsum[i], 1);
650		goto succed;
651	}
652
653	result = ufs_bitmap_search (sb, ucpi, goal, allocsize);
654	if (result == INVBLOCK)
655		return 0;
656	for (i = 0; i < count; i++)
657		ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_freeoff, result + i);
658
659	fs32_sub(sb, &ucg->cg_cs.cs_nffree, count);
660	uspi->cs_total.cs_nffree -= count;
661	fs32_sub(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, count);
662	fs32_sub(sb, &ucg->cg_frsum[allocsize], 1);
663
664	if (count != allocsize)
665		fs32_add(sb, &ucg->cg_frsum[allocsize - count], 1);
666
667succed:
668	ubh_mark_buffer_dirty (USPI_UBH(uspi));
669	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
670	if (sb->s_flags & MS_SYNCHRONOUS)
671		ubh_sync_block(UCPI_UBH(ucpi));
672	ufs_mark_sb_dirty(sb);
673
674	result += cgno * uspi->s_fpg;
675	UFSD("EXIT3, result %llu\n", (unsigned long long)result);
676	return result;
677}
678
679static u64 ufs_alloccg_block(struct inode *inode,
680			     struct ufs_cg_private_info *ucpi,
681			     u64 goal, int *err)
682{
683	struct super_block * sb;
684	struct ufs_sb_private_info * uspi;
685	struct ufs_cylinder_group * ucg;
686	u64 result, blkno;
687
688	UFSD("ENTER, goal %llu\n", (unsigned long long)goal);
689
690	sb = inode->i_sb;
691	uspi = UFS_SB(sb)->s_uspi;
692	ucg = ubh_get_ucg(UCPI_UBH(ucpi));
693
694	if (goal == 0) {
695		goal = ucpi->c_rotor;
696		goto norot;
697	}
698	goal = ufs_blknum (goal);
699	goal = ufs_dtogd(uspi, goal);
700
701	/*
702	 * If the requested block is available, use it.
703	 */
704	if (ubh_isblockset(UCPI_UBH(ucpi), ucpi->c_freeoff, ufs_fragstoblks(goal))) {
705		result = goal;
706		goto gotit;
707	}
708
709norot:
710	result = ufs_bitmap_search (sb, ucpi, goal, uspi->s_fpb);
711	if (result == INVBLOCK)
712		return INVBLOCK;
713	ucpi->c_rotor = result;
714gotit:
715	blkno = ufs_fragstoblks(result);
716	ubh_clrblock (UCPI_UBH(ucpi), ucpi->c_freeoff, blkno);
717	if ((UFS_SB(sb)->s_flags & UFS_CG_MASK) == UFS_CG_44BSD)
718		ufs_clusteracct (sb, ucpi, blkno, -1);
719
720	fs32_sub(sb, &ucg->cg_cs.cs_nbfree, 1);
721	uspi->cs_total.cs_nbfree--;
722	fs32_sub(sb, &UFS_SB(sb)->fs_cs(ucpi->c_cgx).cs_nbfree, 1);
723
724	if (uspi->fs_magic != UFS2_MAGIC) {
725		unsigned cylno = ufs_cbtocylno((unsigned)result);
726
727		fs16_sub(sb, &ubh_cg_blks(ucpi, cylno,
728					  ufs_cbtorpos((unsigned)result)), 1);
729		fs32_sub(sb, &ubh_cg_blktot(ucpi, cylno), 1);
730	}
731
732	UFSD("EXIT, result %llu\n", (unsigned long long)result);
733
734	return result;
735}
736
737static unsigned ubh_scanc(struct ufs_sb_private_info *uspi,
738			  struct ufs_buffer_head *ubh,
739			  unsigned begin, unsigned size,
740			  unsigned char *table, unsigned char mask)
741{
742	unsigned rest, offset;
743	unsigned char *cp;
744
745
746	offset = begin & ~uspi->s_fmask;
747	begin >>= uspi->s_fshift;
748	for (;;) {
749		if ((offset + size) < uspi->s_fsize)
750			rest = size;
751		else
752			rest = uspi->s_fsize - offset;
753		size -= rest;
754		cp = ubh->bh[begin]->b_data + offset;
755		while ((table[*cp++] & mask) == 0 && --rest)
756			;
757		if (rest || !size)
758			break;
759		begin++;
760		offset = 0;
761	}
762	return (size + rest);
763}
764
765/*
766 * Find a block of the specified size in the specified cylinder group.
767 * @sp: pointer to super block
768 * @ucpi: pointer to cylinder group info
769 * @goal: near which block we want find new one
770 * @count: specified size
771 */
772static u64 ufs_bitmap_search(struct super_block *sb,
773			     struct ufs_cg_private_info *ucpi,
774			     u64 goal, unsigned count)
775{
776	/*
777	 * Bit patterns for identifying fragments in the block map
778	 * used as ((map & mask_arr) == want_arr)
779	 */
780	static const int mask_arr[9] = {
781		0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff
782	};
783	static const int want_arr[9] = {
784		0x0, 0x2, 0x6, 0xe, 0x1e, 0x3e, 0x7e, 0xfe, 0x1fe
785	};
786	struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
787	unsigned start, length, loc;
788	unsigned pos, want, blockmap, mask, end;
789	u64 result;
790
791	UFSD("ENTER, cg %u, goal %llu, count %u\n", ucpi->c_cgx,
792	     (unsigned long long)goal, count);
793
794	if (goal)
795		start = ufs_dtogd(uspi, goal) >> 3;
796	else
797		start = ucpi->c_frotor >> 3;
798
799	length = ((uspi->s_fpg + 7) >> 3) - start;
800	loc = ubh_scanc(uspi, UCPI_UBH(ucpi), ucpi->c_freeoff + start, length,
801		(uspi->s_fpb == 8) ? ufs_fragtable_8fpb : ufs_fragtable_other,
802		1 << (count - 1 + (uspi->s_fpb & 7)));
803	if (loc == 0) {
804		length = start + 1;
805		loc = ubh_scanc(uspi, UCPI_UBH(ucpi), ucpi->c_freeoff, length,
806				(uspi->s_fpb == 8) ? ufs_fragtable_8fpb :
807				ufs_fragtable_other,
808				1 << (count - 1 + (uspi->s_fpb & 7)));
809		if (loc == 0) {
810			ufs_error(sb, "ufs_bitmap_search",
811				  "bitmap corrupted on cg %u, start %u,"
812				  " length %u, count %u, freeoff %u\n",
813				  ucpi->c_cgx, start, length, count,
814				  ucpi->c_freeoff);
815			return INVBLOCK;
816		}
817		start = 0;
818	}
819	result = (start + length - loc) << 3;
820	ucpi->c_frotor = result;
821
822	/*
823	 * found the byte in the map
824	 */
825
826	for (end = result + 8; result < end; result += uspi->s_fpb) {
827		blockmap = ubh_blkmap(UCPI_UBH(ucpi), ucpi->c_freeoff, result);
828		blockmap <<= 1;
829		mask = mask_arr[count];
830		want = want_arr[count];
831		for (pos = 0; pos <= uspi->s_fpb - count; pos++) {
832			if ((blockmap & mask) == want) {
833				UFSD("EXIT, result %llu\n",
834				     (unsigned long long)result);
835				return result + pos;
836 			}
837			mask <<= 1;
838			want <<= 1;
839 		}
840 	}
841
842	ufs_error(sb, "ufs_bitmap_search", "block not in map on cg %u\n",
843		  ucpi->c_cgx);
844	UFSD("EXIT (FAILED)\n");
845	return INVBLOCK;
846}
847
848static void ufs_clusteracct(struct super_block * sb,
849	struct ufs_cg_private_info * ucpi, unsigned blkno, int cnt)
850{
851	struct ufs_sb_private_info * uspi;
852	int i, start, end, forw, back;
853
854	uspi = UFS_SB(sb)->s_uspi;
855	if (uspi->s_contigsumsize <= 0)
856		return;
857
858	if (cnt > 0)
859		ubh_setbit(UCPI_UBH(ucpi), ucpi->c_clusteroff, blkno);
860	else
861		ubh_clrbit(UCPI_UBH(ucpi), ucpi->c_clusteroff, blkno);
862
863	/*
864	 * Find the size of the cluster going forward.
865	 */
866	start = blkno + 1;
867	end = start + uspi->s_contigsumsize;
868	if ( end >= ucpi->c_nclusterblks)
869		end = ucpi->c_nclusterblks;
870	i = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_clusteroff, end, start);
871	if (i > end)
872		i = end;
873	forw = i - start;
874
875	/*
876	 * Find the size of the cluster going backward.
877	 */
878	start = blkno - 1;
879	end = start - uspi->s_contigsumsize;
880	if (end < 0 )
881		end = -1;
882	i = ubh_find_last_zero_bit (UCPI_UBH(ucpi), ucpi->c_clusteroff, start, end);
883	if ( i < end)
884		i = end;
885	back = start - i;
886
887	/*
888	 * Account for old cluster and the possibly new forward and
889	 * back clusters.
890	 */
891	i = back + forw + 1;
892	if (i > uspi->s_contigsumsize)
893		i = uspi->s_contigsumsize;
894	fs32_add(sb, (__fs32*)ubh_get_addr(UCPI_UBH(ucpi), ucpi->c_clustersumoff + (i << 2)), cnt);
895	if (back > 0)
896		fs32_sub(sb, (__fs32*)ubh_get_addr(UCPI_UBH(ucpi), ucpi->c_clustersumoff + (back << 2)), cnt);
897	if (forw > 0)
898		fs32_sub(sb, (__fs32*)ubh_get_addr(UCPI_UBH(ucpi), ucpi->c_clustersumoff + (forw << 2)), cnt);
899}
900
901
902static unsigned char ufs_fragtable_8fpb[] = {
903	0x00, 0x01, 0x01, 0x02, 0x01, 0x01, 0x02, 0x04, 0x01, 0x01, 0x01, 0x03, 0x02, 0x03, 0x04, 0x08,
904	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x02, 0x03, 0x03, 0x02, 0x04, 0x05, 0x08, 0x10,
905	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
906	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 0x04, 0x05, 0x05, 0x06, 0x08, 0x09, 0x10, 0x20,
907	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
908	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
909	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0A,
910	0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04, 0x08, 0x09, 0x09, 0x0A, 0x10, 0x11, 0x20, 0x40,
911	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
912	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
913	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
914	0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07, 0x05, 0x05, 0x05, 0x07, 0x09, 0x09, 0x11, 0x21,
915	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0A,
916	0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07, 0x02, 0x03, 0x03, 0x02, 0x06, 0x07, 0x0A, 0x12,
917	0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04, 0x05, 0x05, 0x05, 0x07, 0x06, 0x07, 0x04, 0x0C,
918	0x08, 0x09, 0x09, 0x0A, 0x09, 0x09, 0x0A, 0x0C, 0x10, 0x11, 0x11, 0x12, 0x20, 0x21, 0x40, 0x80,
919};
920
921static unsigned char ufs_fragtable_other[] = {
922	0x00, 0x16, 0x16, 0x2A, 0x16, 0x16, 0x26, 0x4E, 0x16, 0x16, 0x16, 0x3E, 0x2A, 0x3E, 0x4E, 0x8A,
923	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
924	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
925	0x2A, 0x3E, 0x3E, 0x2A, 0x3E, 0x3E, 0x2E, 0x6E, 0x3E, 0x3E, 0x3E, 0x3E, 0x2A, 0x3E, 0x6E, 0xAA,
926	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
927	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
928	0x26, 0x36, 0x36, 0x2E, 0x36, 0x36, 0x26, 0x6E, 0x36, 0x36, 0x36, 0x3E, 0x2E, 0x3E, 0x6E, 0xAE,
929	0x4E, 0x5E, 0x5E, 0x6E, 0x5E, 0x5E, 0x6E, 0x4E, 0x5E, 0x5E, 0x5E, 0x7E, 0x6E, 0x7E, 0x4E, 0xCE,
930	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
931	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
932	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
933	0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x7E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x7E, 0xBE,
934	0x2A, 0x3E, 0x3E, 0x2A, 0x3E, 0x3E, 0x2E, 0x6E, 0x3E, 0x3E, 0x3E, 0x3E, 0x2A, 0x3E, 0x6E, 0xAA,
935	0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x7E,	0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x7E, 0xBE,
936	0x4E, 0x5E, 0x5E, 0x6E, 0x5E, 0x5E, 0x6E, 0x4E, 0x5E, 0x5E, 0x5E, 0x7E, 0x6E, 0x7E, 0x4E, 0xCE,
937	0x8A, 0x9E, 0x9E, 0xAA, 0x9E, 0x9E, 0xAE, 0xCE, 0x9E, 0x9E, 0x9E, 0xBE, 0xAA, 0xBE, 0xCE, 0x8A,
938};
939