Linux Audio

Check our new training course

Linux debugging, profiling, tracing and performance analysis training

Apr 14-17, 2025
Register
Loading...
v4.10.11
 
  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 <linux/bio.h>
 19#include <asm/byteorder.h>
 20
 21#include "ufs_fs.h"
 22#include "ufs.h"
 23#include "swab.h"
 24#include "util.h"
 25
 26#define INVBLOCK ((u64)-1L)
 27
 28static u64 ufs_add_fragments(struct inode *, u64, unsigned, unsigned);
 29static u64 ufs_alloc_fragments(struct inode *, unsigned, u64, unsigned, int *);
 30static u64 ufs_alloccg_block(struct inode *, struct ufs_cg_private_info *, u64, int *);
 31static u64 ufs_bitmap_search (struct super_block *, struct ufs_cg_private_info *, u64, unsigned);
 32static unsigned char ufs_fragtable_8fpb[], ufs_fragtable_other[];
 33static void ufs_clusteracct(struct super_block *, struct ufs_cg_private_info *, unsigned, int);
 34
 35/*
 36 * Free 'count' fragments from fragment number 'fragment'
 37 */
 38void ufs_free_fragments(struct inode *inode, u64 fragment, unsigned count)
 39{
 40	struct super_block * sb;
 41	struct ufs_sb_private_info * uspi;
 42	struct ufs_cg_private_info * ucpi;
 43	struct ufs_cylinder_group * ucg;
 44	unsigned cgno, bit, end_bit, bbase, blkmap, i;
 45	u64 blkno;
 46	
 47	sb = inode->i_sb;
 48	uspi = UFS_SB(sb)->s_uspi;
 49	
 50	UFSD("ENTER, fragment %llu, count %u\n",
 51	     (unsigned long long)fragment, count);
 52	
 53	if (ufs_fragnum(fragment) + count > uspi->s_fpg)
 54		ufs_error (sb, "ufs_free_fragments", "internal error");
 55
 56	mutex_lock(&UFS_SB(sb)->s_lock);
 57	
 58	cgno = ufs_dtog(uspi, fragment);
 59	bit = ufs_dtogd(uspi, fragment);
 60	if (cgno >= uspi->s_ncg) {
 61		ufs_panic (sb, "ufs_free_fragments", "freeing blocks are outside device");
 62		goto failed;
 63	}
 64		
 65	ucpi = ufs_load_cylinder (sb, cgno);
 66	if (!ucpi) 
 67		goto failed;
 68	ucg = ubh_get_ucg (UCPI_UBH(ucpi));
 69	if (!ufs_cg_chkmagic(sb, ucg)) {
 70		ufs_panic (sb, "ufs_free_fragments", "internal error, bad magic number on cg %u", cgno);
 71		goto failed;
 72	}
 73
 74	end_bit = bit + count;
 75	bbase = ufs_blknum (bit);
 76	blkmap = ubh_blkmap (UCPI_UBH(ucpi), ucpi->c_freeoff, bbase);
 77	ufs_fragacct (sb, blkmap, ucg->cg_frsum, -1);
 78	for (i = bit; i < end_bit; i++) {
 79		if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_freeoff, i))
 80			ubh_setbit (UCPI_UBH(ucpi), ucpi->c_freeoff, i);
 81		else 
 82			ufs_error (sb, "ufs_free_fragments",
 83				   "bit already cleared for fragment %u", i);
 84	}
 85	
 
 86	fs32_add(sb, &ucg->cg_cs.cs_nffree, count);
 87	uspi->cs_total.cs_nffree += count;
 88	fs32_add(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, count);
 89	blkmap = ubh_blkmap (UCPI_UBH(ucpi), ucpi->c_freeoff, bbase);
 90	ufs_fragacct(sb, blkmap, ucg->cg_frsum, 1);
 91
 92	/*
 93	 * Trying to reassemble free fragments into block
 94	 */
 95	blkno = ufs_fragstoblks (bbase);
 96	if (ubh_isblockset(UCPI_UBH(ucpi), ucpi->c_freeoff, blkno)) {
 97		fs32_sub(sb, &ucg->cg_cs.cs_nffree, uspi->s_fpb);
 98		uspi->cs_total.cs_nffree -= uspi->s_fpb;
 99		fs32_sub(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, uspi->s_fpb);
100		if ((UFS_SB(sb)->s_flags & UFS_CG_MASK) == UFS_CG_44BSD)
101			ufs_clusteracct (sb, ucpi, blkno, 1);
102		fs32_add(sb, &ucg->cg_cs.cs_nbfree, 1);
103		uspi->cs_total.cs_nbfree++;
104		fs32_add(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nbfree, 1);
105		if (uspi->fs_magic != UFS2_MAGIC) {
106			unsigned cylno = ufs_cbtocylno (bbase);
107
108			fs16_add(sb, &ubh_cg_blks(ucpi, cylno,
109						  ufs_cbtorpos(bbase)), 1);
110			fs32_add(sb, &ubh_cg_blktot(ucpi, cylno), 1);
111		}
112	}
113	
114	ubh_mark_buffer_dirty (USPI_UBH(uspi));
115	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
116	if (sb->s_flags & MS_SYNCHRONOUS)
117		ubh_sync_block(UCPI_UBH(ucpi));
118	ufs_mark_sb_dirty(sb);
119
120	mutex_unlock(&UFS_SB(sb)->s_lock);
121	UFSD("EXIT\n");
122	return;
123
124failed:
125	mutex_unlock(&UFS_SB(sb)->s_lock);
126	UFSD("EXIT (FAILED)\n");
127	return;
128}
129
130/*
131 * Free 'count' fragments from fragment number 'fragment' (free whole blocks)
132 */
133void ufs_free_blocks(struct inode *inode, u64 fragment, unsigned count)
134{
135	struct super_block * sb;
136	struct ufs_sb_private_info * uspi;
137	struct ufs_cg_private_info * ucpi;
138	struct ufs_cylinder_group * ucg;
139	unsigned overflow, cgno, bit, end_bit, i;
140	u64 blkno;
141	
142	sb = inode->i_sb;
143	uspi = UFS_SB(sb)->s_uspi;
144
145	UFSD("ENTER, fragment %llu, count %u\n",
146	     (unsigned long long)fragment, count);
147	
148	if ((fragment & uspi->s_fpbmask) || (count & uspi->s_fpbmask)) {
149		ufs_error (sb, "ufs_free_blocks", "internal error, "
150			   "fragment %llu, count %u\n",
151			   (unsigned long long)fragment, count);
152		goto failed;
153	}
154
155	mutex_lock(&UFS_SB(sb)->s_lock);
156	
157do_more:
158	overflow = 0;
159	cgno = ufs_dtog(uspi, fragment);
160	bit = ufs_dtogd(uspi, fragment);
161	if (cgno >= uspi->s_ncg) {
162		ufs_panic (sb, "ufs_free_blocks", "freeing blocks are outside device");
163		goto failed_unlock;
164	}
165	end_bit = bit + count;
166	if (end_bit > uspi->s_fpg) {
167		overflow = bit + count - uspi->s_fpg;
168		count -= overflow;
169		end_bit -= overflow;
170	}
171
172	ucpi = ufs_load_cylinder (sb, cgno);
173	if (!ucpi) 
174		goto failed_unlock;
175	ucg = ubh_get_ucg (UCPI_UBH(ucpi));
176	if (!ufs_cg_chkmagic(sb, ucg)) {
177		ufs_panic (sb, "ufs_free_blocks", "internal error, bad magic number on cg %u", cgno);
178		goto failed_unlock;
179	}
180
181	for (i = bit; i < end_bit; i += uspi->s_fpb) {
182		blkno = ufs_fragstoblks(i);
183		if (ubh_isblockset(UCPI_UBH(ucpi), ucpi->c_freeoff, blkno)) {
184			ufs_error(sb, "ufs_free_blocks", "freeing free fragment");
185		}
186		ubh_setblock(UCPI_UBH(ucpi), ucpi->c_freeoff, blkno);
 
187		if ((UFS_SB(sb)->s_flags & UFS_CG_MASK) == UFS_CG_44BSD)
188			ufs_clusteracct (sb, ucpi, blkno, 1);
189
190		fs32_add(sb, &ucg->cg_cs.cs_nbfree, 1);
191		uspi->cs_total.cs_nbfree++;
192		fs32_add(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nbfree, 1);
193
194		if (uspi->fs_magic != UFS2_MAGIC) {
195			unsigned cylno = ufs_cbtocylno(i);
196
197			fs16_add(sb, &ubh_cg_blks(ucpi, cylno,
198						  ufs_cbtorpos(i)), 1);
199			fs32_add(sb, &ubh_cg_blktot(ucpi, cylno), 1);
200		}
201	}
202
203	ubh_mark_buffer_dirty (USPI_UBH(uspi));
204	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
205	if (sb->s_flags & MS_SYNCHRONOUS)
206		ubh_sync_block(UCPI_UBH(ucpi));
207
208	if (overflow) {
209		fragment += count;
210		count = overflow;
211		goto do_more;
212	}
213
214	ufs_mark_sb_dirty(sb);
215	mutex_unlock(&UFS_SB(sb)->s_lock);
216	UFSD("EXIT\n");
217	return;
218
219failed_unlock:
220	mutex_unlock(&UFS_SB(sb)->s_lock);
221failed:
222	UFSD("EXIT (FAILED)\n");
223	return;
224}
225
226/*
227 * Modify inode page cache in such way:
228 * have - blocks with b_blocknr equal to oldb...oldb+count-1
229 * get - blocks with b_blocknr equal to newb...newb+count-1
230 * also we suppose that oldb...oldb+count-1 blocks
231 * situated at the end of file.
232 *
233 * We can come here from ufs_writepage or ufs_prepare_write,
234 * locked_page is argument of these functions, so we already lock it.
235 */
236static void ufs_change_blocknr(struct inode *inode, sector_t beg,
237			       unsigned int count, sector_t oldb,
238			       sector_t newb, struct page *locked_page)
239{
240	const unsigned blks_per_page =
241		1 << (PAGE_SHIFT - inode->i_blkbits);
242	const unsigned mask = blks_per_page - 1;
243	struct address_space * const mapping = inode->i_mapping;
244	pgoff_t index, cur_index, last_index;
245	unsigned pos, j, lblock;
246	sector_t end, i;
247	struct page *page;
248	struct buffer_head *head, *bh;
249
250	UFSD("ENTER, ino %lu, count %u, oldb %llu, newb %llu\n",
251	      inode->i_ino, count,
252	     (unsigned long long)oldb, (unsigned long long)newb);
253
254	BUG_ON(!locked_page);
255	BUG_ON(!PageLocked(locked_page));
256
257	cur_index = locked_page->index;
258	end = count + beg;
259	last_index = end >> (PAGE_SHIFT - inode->i_blkbits);
260	for (i = beg; i < end; i = (i | mask) + 1) {
261		index = i >> (PAGE_SHIFT - inode->i_blkbits);
262
263		if (likely(cur_index != index)) {
264			page = ufs_get_locked_page(mapping, index);
265			if (!page)/* it was truncated */
266				continue;
267			if (IS_ERR(page)) {/* or EIO */
268				ufs_error(inode->i_sb, __func__,
269					  "read of page %llu failed\n",
270					  (unsigned long long)index);
271				continue;
272			}
273		} else
274			page = locked_page;
275
276		head = page_buffers(page);
277		bh = head;
278		pos = i & mask;
279		for (j = 0; j < pos; ++j)
280			bh = bh->b_this_page;
281
282
283		if (unlikely(index == last_index))
284			lblock = end & mask;
285		else
286			lblock = blks_per_page;
287
288		do {
289			if (j >= lblock)
290				break;
291			pos = (i - beg) + j;
292
293			if (!buffer_mapped(bh))
294					map_bh(bh, inode->i_sb, oldb + pos);
295			if (!buffer_uptodate(bh)) {
296				ll_rw_block(REQ_OP_READ, 0, 1, &bh);
297				wait_on_buffer(bh);
298				if (!buffer_uptodate(bh)) {
299					ufs_error(inode->i_sb, __func__,
300						  "read of block failed\n");
301					break;
302				}
303			}
304
305			UFSD(" change from %llu to %llu, pos %u\n",
306			     (unsigned long long)(pos + oldb),
307			     (unsigned long long)(pos + newb), pos);
308
309			bh->b_blocknr = newb + pos;
310			clean_bdev_bh_alias(bh);
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_clear_frags(inode, result + oldcount,
421					newcount - oldcount, locked_page != NULL);
 
422			write_seqlock(&UFS_I(inode)->meta_lock);
423			ufs_cpu_to_data_ptr(sb, p, result);
424			write_sequnlock(&UFS_I(inode)->meta_lock);
425			*err = 0;
426			UFS_I(inode)->i_lastfrag =
427				max(UFS_I(inode)->i_lastfrag, fragment + count);
 
428		}
429		mutex_unlock(&UFS_SB(sb)->s_lock);
430		UFSD("EXIT, result %llu\n", (unsigned long long)result);
431		return result;
432	}
433
434	/*
435	 * resize block
436	 */
437	result = ufs_add_fragments(inode, tmp, oldcount, newcount);
438	if (result) {
439		*err = 0;
 
440		UFS_I(inode)->i_lastfrag = max(UFS_I(inode)->i_lastfrag,
441						fragment + count);
 
442		ufs_clear_frags(inode, result + oldcount, newcount - oldcount,
443				locked_page != NULL);
444		mutex_unlock(&UFS_SB(sb)->s_lock);
445		UFSD("EXIT, result %llu\n", (unsigned long long)result);
446		return result;
447	}
448
449	/*
450	 * allocate new block and move data
451	 */
452	switch (fs32_to_cpu(sb, usb1->fs_optim)) {
453	    case UFS_OPTSPACE:
454		request = newcount;
455		if (uspi->s_minfree < 5 || uspi->cs_total.cs_nffree
456		    > uspi->s_dsize * uspi->s_minfree / (2 * 100))
457			break;
458		usb1->fs_optim = cpu_to_fs32(sb, UFS_OPTTIME);
459		break;
460	    default:
461		usb1->fs_optim = cpu_to_fs32(sb, UFS_OPTTIME);
462	
463	    case UFS_OPTTIME:
464		request = uspi->s_fpb;
465		if (uspi->cs_total.cs_nffree < uspi->s_dsize *
466		    (uspi->s_minfree - 2) / 100)
467			break;
468		usb1->fs_optim = cpu_to_fs32(sb, UFS_OPTTIME);
469		break;
470	}
471	result = ufs_alloc_fragments (inode, cgno, goal, request, err);
472	if (result) {
473		ufs_clear_frags(inode, result + oldcount, newcount - oldcount,
474				locked_page != NULL);
 
475		ufs_change_blocknr(inode, fragment - oldcount, oldcount,
476				   uspi->s_sbbase + tmp,
477				   uspi->s_sbbase + result, locked_page);
 
478		write_seqlock(&UFS_I(inode)->meta_lock);
479		ufs_cpu_to_data_ptr(sb, p, result);
480		write_sequnlock(&UFS_I(inode)->meta_lock);
481		*err = 0;
482		UFS_I(inode)->i_lastfrag = max(UFS_I(inode)->i_lastfrag,
483						fragment + count);
484		mutex_unlock(&UFS_SB(sb)->s_lock);
485		if (newcount < request)
486			ufs_free_fragments (inode, result + newcount, request - newcount);
487		ufs_free_fragments (inode, tmp, oldcount);
488		UFSD("EXIT, result %llu\n", (unsigned long long)result);
489		return result;
490	}
491
492	mutex_unlock(&UFS_SB(sb)->s_lock);
493	UFSD("EXIT (FAILED)\n");
494	return 0;
495}		
496
 
 
 
 
 
 
 
 
 
 
 
 
 
 
497static u64 ufs_add_fragments(struct inode *inode, u64 fragment,
498			     unsigned oldcount, unsigned newcount)
499{
500	struct super_block * sb;
501	struct ufs_sb_private_info * uspi;
502	struct ufs_cg_private_info * ucpi;
503	struct ufs_cylinder_group * ucg;
504	unsigned cgno, fragno, fragoff, count, fragsize, i;
505	
506	UFSD("ENTER, fragment %llu, oldcount %u, newcount %u\n",
507	     (unsigned long long)fragment, oldcount, newcount);
508	
509	sb = inode->i_sb;
510	uspi = UFS_SB(sb)->s_uspi;
511	count = newcount - oldcount;
512	
513	cgno = ufs_dtog(uspi, fragment);
514	if (fs32_to_cpu(sb, UFS_SB(sb)->fs_cs(cgno).cs_nffree) < count)
515		return 0;
516	if ((ufs_fragnum (fragment) + newcount) > uspi->s_fpb)
517		return 0;
518	ucpi = ufs_load_cylinder (sb, cgno);
519	if (!ucpi)
520		return 0;
521	ucg = ubh_get_ucg (UCPI_UBH(ucpi));
522	if (!ufs_cg_chkmagic(sb, ucg)) {
523		ufs_panic (sb, "ufs_add_fragments",
524			"internal error, bad magic number on cg %u", cgno);
525		return 0;
526	}
527
528	fragno = ufs_dtogd(uspi, fragment);
529	fragoff = ufs_fragnum (fragno);
530	for (i = oldcount; i < newcount; i++)
531		if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_freeoff, fragno + i))
532			return 0;
 
 
 
533	/*
534	 * Block can be extended
535	 */
536	ucg->cg_time = cpu_to_fs32(sb, get_seconds());
537	for (i = newcount; i < (uspi->s_fpb - fragoff); i++)
538		if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_freeoff, fragno + i))
539			break;
540	fragsize = i - oldcount;
541	if (!fs32_to_cpu(sb, ucg->cg_frsum[fragsize]))
542		ufs_panic (sb, "ufs_add_fragments",
543			"internal error or corrupted bitmap on cg %u", cgno);
544	fs32_sub(sb, &ucg->cg_frsum[fragsize], 1);
545	if (fragsize != count)
546		fs32_add(sb, &ucg->cg_frsum[fragsize - count], 1);
547	for (i = oldcount; i < newcount; i++)
548		ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_freeoff, fragno + i);
549
550	fs32_sub(sb, &ucg->cg_cs.cs_nffree, count);
551	fs32_sub(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, count);
552	uspi->cs_total.cs_nffree -= count;
553	
554	ubh_mark_buffer_dirty (USPI_UBH(uspi));
555	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
556	if (sb->s_flags & MS_SYNCHRONOUS)
557		ubh_sync_block(UCPI_UBH(ucpi));
558	ufs_mark_sb_dirty(sb);
559
560	UFSD("EXIT, fragment %llu\n", (unsigned long long)fragment);
561	
562	return fragment;
563}
564
565#define UFS_TEST_FREE_SPACE_CG \
566	ucg = (struct ufs_cylinder_group *) UFS_SB(sb)->s_ucg[cgno]->b_data; \
567	if (fs32_to_cpu(sb, ucg->cg_cs.cs_nbfree)) \
568		goto cg_found; \
569	for (k = count; k < uspi->s_fpb; k++) \
570		if (fs32_to_cpu(sb, ucg->cg_frsum[k])) \
571			goto cg_found; 
572
573static u64 ufs_alloc_fragments(struct inode *inode, unsigned cgno,
574			       u64 goal, unsigned count, int *err)
575{
576	struct super_block * sb;
577	struct ufs_sb_private_info * uspi;
578	struct ufs_cg_private_info * ucpi;
579	struct ufs_cylinder_group * ucg;
580	unsigned oldcg, i, j, k, allocsize;
581	u64 result;
582	
583	UFSD("ENTER, ino %lu, cgno %u, goal %llu, count %u\n",
584	     inode->i_ino, cgno, (unsigned long long)goal, count);
585
586	sb = inode->i_sb;
587	uspi = UFS_SB(sb)->s_uspi;
588	oldcg = cgno;
589	
590	/*
591	 * 1. searching on preferred cylinder group
592	 */
593	UFS_TEST_FREE_SPACE_CG
594
595	/*
596	 * 2. quadratic rehash
597	 */
598	for (j = 1; j < uspi->s_ncg; j *= 2) {
599		cgno += j;
600		if (cgno >= uspi->s_ncg) 
601			cgno -= uspi->s_ncg;
602		UFS_TEST_FREE_SPACE_CG
603	}
604
605	/*
606	 * 3. brute force search
607	 * We start at i = 2 ( 0 is checked at 1.step, 1 at 2.step )
608	 */
609	cgno = (oldcg + 1) % uspi->s_ncg;
610	for (j = 2; j < uspi->s_ncg; j++) {
611		cgno++;
612		if (cgno >= uspi->s_ncg)
613			cgno = 0;
614		UFS_TEST_FREE_SPACE_CG
615	}
616	
617	UFSD("EXIT (FAILED)\n");
618	return 0;
619
620cg_found:
621	ucpi = ufs_load_cylinder (sb, cgno);
622	if (!ucpi)
623		return 0;
624	ucg = ubh_get_ucg (UCPI_UBH(ucpi));
625	if (!ufs_cg_chkmagic(sb, ucg)) 
626		ufs_panic (sb, "ufs_alloc_fragments",
627			"internal error, bad magic number on cg %u", cgno);
628	ucg->cg_time = cpu_to_fs32(sb, get_seconds());
629
630	if (count == uspi->s_fpb) {
631		result = ufs_alloccg_block (inode, ucpi, goal, err);
632		if (result == INVBLOCK)
633			return 0;
634		goto succed;
635	}
636
637	for (allocsize = count; allocsize < uspi->s_fpb; allocsize++)
638		if (fs32_to_cpu(sb, ucg->cg_frsum[allocsize]) != 0)
639			break;
640	
641	if (allocsize == uspi->s_fpb) {
642		result = ufs_alloccg_block (inode, ucpi, goal, err);
643		if (result == INVBLOCK)
644			return 0;
645		goal = ufs_dtogd(uspi, result);
646		for (i = count; i < uspi->s_fpb; i++)
647			ubh_setbit (UCPI_UBH(ucpi), ucpi->c_freeoff, goal + i);
648		i = uspi->s_fpb - count;
649
 
650		fs32_add(sb, &ucg->cg_cs.cs_nffree, i);
651		uspi->cs_total.cs_nffree += i;
652		fs32_add(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, i);
653		fs32_add(sb, &ucg->cg_frsum[i], 1);
654		goto succed;
655	}
656
657	result = ufs_bitmap_search (sb, ucpi, goal, allocsize);
658	if (result == INVBLOCK)
659		return 0;
 
 
660	for (i = 0; i < count; i++)
661		ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_freeoff, result + i);
662	
663	fs32_sub(sb, &ucg->cg_cs.cs_nffree, count);
664	uspi->cs_total.cs_nffree -= count;
665	fs32_sub(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, count);
666	fs32_sub(sb, &ucg->cg_frsum[allocsize], 1);
667
668	if (count != allocsize)
669		fs32_add(sb, &ucg->cg_frsum[allocsize - count], 1);
670
671succed:
672	ubh_mark_buffer_dirty (USPI_UBH(uspi));
673	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
674	if (sb->s_flags & MS_SYNCHRONOUS)
675		ubh_sync_block(UCPI_UBH(ucpi));
676	ufs_mark_sb_dirty(sb);
677
678	result += cgno * uspi->s_fpg;
679	UFSD("EXIT3, result %llu\n", (unsigned long long)result);
680	return result;
681}
682
683static u64 ufs_alloccg_block(struct inode *inode,
684			     struct ufs_cg_private_info *ucpi,
685			     u64 goal, int *err)
686{
687	struct super_block * sb;
688	struct ufs_sb_private_info * uspi;
689	struct ufs_cylinder_group * ucg;
690	u64 result, blkno;
691
692	UFSD("ENTER, goal %llu\n", (unsigned long long)goal);
693
694	sb = inode->i_sb;
695	uspi = UFS_SB(sb)->s_uspi;
696	ucg = ubh_get_ucg(UCPI_UBH(ucpi));
697
698	if (goal == 0) {
699		goal = ucpi->c_rotor;
700		goto norot;
701	}
702	goal = ufs_blknum (goal);
703	goal = ufs_dtogd(uspi, goal);
704	
705	/*
706	 * If the requested block is available, use it.
707	 */
708	if (ubh_isblockset(UCPI_UBH(ucpi), ucpi->c_freeoff, ufs_fragstoblks(goal))) {
709		result = goal;
710		goto gotit;
711	}
712	
713norot:	
714	result = ufs_bitmap_search (sb, ucpi, goal, uspi->s_fpb);
715	if (result == INVBLOCK)
716		return INVBLOCK;
717	ucpi->c_rotor = result;
718gotit:
 
 
719	blkno = ufs_fragstoblks(result);
720	ubh_clrblock (UCPI_UBH(ucpi), ucpi->c_freeoff, blkno);
721	if ((UFS_SB(sb)->s_flags & UFS_CG_MASK) == UFS_CG_44BSD)
722		ufs_clusteracct (sb, ucpi, blkno, -1);
723
724	fs32_sub(sb, &ucg->cg_cs.cs_nbfree, 1);
725	uspi->cs_total.cs_nbfree--;
726	fs32_sub(sb, &UFS_SB(sb)->fs_cs(ucpi->c_cgx).cs_nbfree, 1);
727
728	if (uspi->fs_magic != UFS2_MAGIC) {
729		unsigned cylno = ufs_cbtocylno((unsigned)result);
730
731		fs16_sub(sb, &ubh_cg_blks(ucpi, cylno,
732					  ufs_cbtorpos((unsigned)result)), 1);
733		fs32_sub(sb, &ubh_cg_blktot(ucpi, cylno), 1);
734	}
735	
736	UFSD("EXIT, result %llu\n", (unsigned long long)result);
737
738	return result;
739}
740
741static unsigned ubh_scanc(struct ufs_sb_private_info *uspi,
742			  struct ufs_buffer_head *ubh,
743			  unsigned begin, unsigned size,
744			  unsigned char *table, unsigned char mask)
745{
746	unsigned rest, offset;
747	unsigned char *cp;
748	
749
750	offset = begin & ~uspi->s_fmask;
751	begin >>= uspi->s_fshift;
752	for (;;) {
753		if ((offset + size) < uspi->s_fsize)
754			rest = size;
755		else
756			rest = uspi->s_fsize - offset;
757		size -= rest;
758		cp = ubh->bh[begin]->b_data + offset;
759		while ((table[*cp++] & mask) == 0 && --rest)
760			;
761		if (rest || !size)
762			break;
763		begin++;
764		offset = 0;
765	}
766	return (size + rest);
767}
768
769/*
770 * Find a block of the specified size in the specified cylinder group.
771 * @sp: pointer to super block
772 * @ucpi: pointer to cylinder group info
773 * @goal: near which block we want find new one
774 * @count: specified size
775 */
776static u64 ufs_bitmap_search(struct super_block *sb,
777			     struct ufs_cg_private_info *ucpi,
778			     u64 goal, unsigned count)
779{
780	/*
781	 * Bit patterns for identifying fragments in the block map
782	 * used as ((map & mask_arr) == want_arr)
783	 */
784	static const int mask_arr[9] = {
785		0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff
786	};
787	static const int want_arr[9] = {
788		0x0, 0x2, 0x6, 0xe, 0x1e, 0x3e, 0x7e, 0xfe, 0x1fe
789	};
790	struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
791	unsigned start, length, loc;
792	unsigned pos, want, blockmap, mask, end;
793	u64 result;
794
795	UFSD("ENTER, cg %u, goal %llu, count %u\n", ucpi->c_cgx,
796	     (unsigned long long)goal, count);
797
798	if (goal)
799		start = ufs_dtogd(uspi, goal) >> 3;
800	else
801		start = ucpi->c_frotor >> 3;
802		
803	length = ((uspi->s_fpg + 7) >> 3) - start;
804	loc = ubh_scanc(uspi, UCPI_UBH(ucpi), ucpi->c_freeoff + start, length,
805		(uspi->s_fpb == 8) ? ufs_fragtable_8fpb : ufs_fragtable_other,
806		1 << (count - 1 + (uspi->s_fpb & 7))); 
807	if (loc == 0) {
808		length = start + 1;
809		loc = ubh_scanc(uspi, UCPI_UBH(ucpi), ucpi->c_freeoff, length,
810				(uspi->s_fpb == 8) ? ufs_fragtable_8fpb :
811				ufs_fragtable_other,
812				1 << (count - 1 + (uspi->s_fpb & 7)));
813		if (loc == 0) {
814			ufs_error(sb, "ufs_bitmap_search",
815				  "bitmap corrupted on cg %u, start %u,"
816				  " length %u, count %u, freeoff %u\n",
817				  ucpi->c_cgx, start, length, count,
818				  ucpi->c_freeoff);
819			return INVBLOCK;
820		}
821		start = 0;
822	}
823	result = (start + length - loc) << 3;
824	ucpi->c_frotor = result;
825
826	/*
827	 * found the byte in the map
828	 */
829
830	for (end = result + 8; result < end; result += uspi->s_fpb) {
831		blockmap = ubh_blkmap(UCPI_UBH(ucpi), ucpi->c_freeoff, result);
832		blockmap <<= 1;
833		mask = mask_arr[count];
834		want = want_arr[count];
835		for (pos = 0; pos <= uspi->s_fpb - count; pos++) {
836			if ((blockmap & mask) == want) {
837				UFSD("EXIT, result %llu\n",
838				     (unsigned long long)result);
839				return result + pos;
840 			}
841			mask <<= 1;
842			want <<= 1;
843 		}
844 	}
845
846	ufs_error(sb, "ufs_bitmap_search", "block not in map on cg %u\n",
847		  ucpi->c_cgx);
848	UFSD("EXIT (FAILED)\n");
849	return INVBLOCK;
850}
851
852static void ufs_clusteracct(struct super_block * sb,
853	struct ufs_cg_private_info * ucpi, unsigned blkno, int cnt)
854{
855	struct ufs_sb_private_info * uspi;
856	int i, start, end, forw, back;
857	
858	uspi = UFS_SB(sb)->s_uspi;
859	if (uspi->s_contigsumsize <= 0)
860		return;
861
862	if (cnt > 0)
863		ubh_setbit(UCPI_UBH(ucpi), ucpi->c_clusteroff, blkno);
864	else
865		ubh_clrbit(UCPI_UBH(ucpi), ucpi->c_clusteroff, blkno);
866
867	/*
868	 * Find the size of the cluster going forward.
869	 */
870	start = blkno + 1;
871	end = start + uspi->s_contigsumsize;
872	if ( end >= ucpi->c_nclusterblks)
873		end = ucpi->c_nclusterblks;
874	i = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_clusteroff, end, start);
875	if (i > end)
876		i = end;
877	forw = i - start;
878	
879	/*
880	 * Find the size of the cluster going backward.
881	 */
882	start = blkno - 1;
883	end = start - uspi->s_contigsumsize;
884	if (end < 0 ) 
885		end = -1;
886	i = ubh_find_last_zero_bit (UCPI_UBH(ucpi), ucpi->c_clusteroff, start, end);
887	if ( i < end) 
888		i = end;
889	back = start - i;
890	
891	/*
892	 * Account for old cluster and the possibly new forward and
893	 * back clusters.
894	 */
895	i = back + forw + 1;
896	if (i > uspi->s_contigsumsize)
897		i = uspi->s_contigsumsize;
898	fs32_add(sb, (__fs32*)ubh_get_addr(UCPI_UBH(ucpi), ucpi->c_clustersumoff + (i << 2)), cnt);
899	if (back > 0)
900		fs32_sub(sb, (__fs32*)ubh_get_addr(UCPI_UBH(ucpi), ucpi->c_clustersumoff + (back << 2)), cnt);
901	if (forw > 0)
902		fs32_sub(sb, (__fs32*)ubh_get_addr(UCPI_UBH(ucpi), ucpi->c_clustersumoff + (forw << 2)), cnt);
903}
904
905
906static unsigned char ufs_fragtable_8fpb[] = {
907	0x00, 0x01, 0x01, 0x02, 0x01, 0x01, 0x02, 0x04, 0x01, 0x01, 0x01, 0x03, 0x02, 0x03, 0x04, 0x08,
908	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x02, 0x03, 0x03, 0x02, 0x04, 0x05, 0x08, 0x10,
909	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
910	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 0x04, 0x05, 0x05, 0x06, 0x08, 0x09, 0x10, 0x20,
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	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0A,
914	0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04, 0x08, 0x09, 0x09, 0x0A, 0x10, 0x11, 0x20, 0x40,
915	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
916	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
917	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
918	0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07, 0x05, 0x05, 0x05, 0x07, 0x09, 0x09, 0x11, 0x21,
919	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0A,
920	0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07, 0x02, 0x03, 0x03, 0x02, 0x06, 0x07, 0x0A, 0x12,
921	0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04, 0x05, 0x05, 0x05, 0x07, 0x06, 0x07, 0x04, 0x0C,
922	0x08, 0x09, 0x09, 0x0A, 0x09, 0x09, 0x0A, 0x0C, 0x10, 0x11, 0x11, 0x12, 0x20, 0x21, 0x40, 0x80,
923};
924
925static unsigned char ufs_fragtable_other[] = {
926	0x00, 0x16, 0x16, 0x2A, 0x16, 0x16, 0x26, 0x4E, 0x16, 0x16, 0x16, 0x3E, 0x2A, 0x3E, 0x4E, 0x8A,
927	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
928	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
929	0x2A, 0x3E, 0x3E, 0x2A, 0x3E, 0x3E, 0x2E, 0x6E, 0x3E, 0x3E, 0x3E, 0x3E, 0x2A, 0x3E, 0x6E, 0xAA,
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	0x26, 0x36, 0x36, 0x2E, 0x36, 0x36, 0x26, 0x6E, 0x36, 0x36, 0x36, 0x3E, 0x2E, 0x3E, 0x6E, 0xAE,
933	0x4E, 0x5E, 0x5E, 0x6E, 0x5E, 0x5E, 0x6E, 0x4E, 0x5E, 0x5E, 0x5E, 0x7E, 0x6E, 0x7E, 0x4E, 0xCE,
934	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
935	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
936	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
937	0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x7E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x7E, 0xBE,
938	0x2A, 0x3E, 0x3E, 0x2A, 0x3E, 0x3E, 0x2E, 0x6E, 0x3E, 0x3E, 0x3E, 0x3E, 0x2A, 0x3E, 0x6E, 0xAA,
939	0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x7E,	0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x7E, 0xBE,
940	0x4E, 0x5E, 0x5E, 0x6E, 0x5E, 0x5E, 0x6E, 0x4E, 0x5E, 0x5E, 0x5E, 0x7E, 0x6E, 0x7E, 0x4E, 0xCE,
941	0x8A, 0x9E, 0x9E, 0xAA, 0x9E, 0x9E, 0xAE, 0xCE, 0x9E, 0x9E, 0x9E, 0xBE, 0xAA, 0xBE, 0xCE, 0x8A,
942};
v5.4
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  linux/fs/ufs/balloc.c
  4 *
  5 * Copyright (C) 1998
  6 * Daniel Pirkl <daniel.pirkl@email.cz>
  7 * Charles University, Faculty of Mathematics and Physics
  8 *
  9 * UFS2 write support Evgeniy Dushistov <dushistov@mail.ru>, 2007
 10 */
 11
 12#include <linux/fs.h>
 13#include <linux/stat.h>
 14#include <linux/time.h>
 15#include <linux/string.h>
 16#include <linux/buffer_head.h>
 17#include <linux/capability.h>
 18#include <linux/bitops.h>
 19#include <linux/bio.h>
 20#include <asm/byteorder.h>
 21
 22#include "ufs_fs.h"
 23#include "ufs.h"
 24#include "swab.h"
 25#include "util.h"
 26
 27#define INVBLOCK ((u64)-1L)
 28
 29static u64 ufs_add_fragments(struct inode *, u64, unsigned, unsigned);
 30static u64 ufs_alloc_fragments(struct inode *, unsigned, u64, unsigned, int *);
 31static u64 ufs_alloccg_block(struct inode *, struct ufs_cg_private_info *, u64, int *);
 32static u64 ufs_bitmap_search (struct super_block *, struct ufs_cg_private_info *, u64, unsigned);
 33static unsigned char ufs_fragtable_8fpb[], ufs_fragtable_other[];
 34static void ufs_clusteracct(struct super_block *, struct ufs_cg_private_info *, unsigned, int);
 35
 36/*
 37 * Free 'count' fragments from fragment number 'fragment'
 38 */
 39void ufs_free_fragments(struct inode *inode, u64 fragment, unsigned count)
 40{
 41	struct super_block * sb;
 42	struct ufs_sb_private_info * uspi;
 43	struct ufs_cg_private_info * ucpi;
 44	struct ufs_cylinder_group * ucg;
 45	unsigned cgno, bit, end_bit, bbase, blkmap, i;
 46	u64 blkno;
 47	
 48	sb = inode->i_sb;
 49	uspi = UFS_SB(sb)->s_uspi;
 50	
 51	UFSD("ENTER, fragment %llu, count %u\n",
 52	     (unsigned long long)fragment, count);
 53	
 54	if (ufs_fragnum(fragment) + count > uspi->s_fpg)
 55		ufs_error (sb, "ufs_free_fragments", "internal error");
 56
 57	mutex_lock(&UFS_SB(sb)->s_lock);
 58	
 59	cgno = ufs_dtog(uspi, fragment);
 60	bit = ufs_dtogd(uspi, fragment);
 61	if (cgno >= uspi->s_ncg) {
 62		ufs_panic (sb, "ufs_free_fragments", "freeing blocks are outside device");
 63		goto failed;
 64	}
 65		
 66	ucpi = ufs_load_cylinder (sb, cgno);
 67	if (!ucpi) 
 68		goto failed;
 69	ucg = ubh_get_ucg (UCPI_UBH(ucpi));
 70	if (!ufs_cg_chkmagic(sb, ucg)) {
 71		ufs_panic (sb, "ufs_free_fragments", "internal error, bad magic number on cg %u", cgno);
 72		goto failed;
 73	}
 74
 75	end_bit = bit + count;
 76	bbase = ufs_blknum (bit);
 77	blkmap = ubh_blkmap (UCPI_UBH(ucpi), ucpi->c_freeoff, bbase);
 78	ufs_fragacct (sb, blkmap, ucg->cg_frsum, -1);
 79	for (i = bit; i < end_bit; i++) {
 80		if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_freeoff, i))
 81			ubh_setbit (UCPI_UBH(ucpi), ucpi->c_freeoff, i);
 82		else 
 83			ufs_error (sb, "ufs_free_fragments",
 84				   "bit already cleared for fragment %u", i);
 85	}
 86
 87	inode_sub_bytes(inode, count << uspi->s_fshift);
 88	fs32_add(sb, &ucg->cg_cs.cs_nffree, count);
 89	uspi->cs_total.cs_nffree += count;
 90	fs32_add(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, count);
 91	blkmap = ubh_blkmap (UCPI_UBH(ucpi), ucpi->c_freeoff, bbase);
 92	ufs_fragacct(sb, blkmap, ucg->cg_frsum, 1);
 93
 94	/*
 95	 * Trying to reassemble free fragments into block
 96	 */
 97	blkno = ufs_fragstoblks (bbase);
 98	if (ubh_isblockset(UCPI_UBH(ucpi), ucpi->c_freeoff, blkno)) {
 99		fs32_sub(sb, &ucg->cg_cs.cs_nffree, uspi->s_fpb);
100		uspi->cs_total.cs_nffree -= uspi->s_fpb;
101		fs32_sub(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, uspi->s_fpb);
102		if ((UFS_SB(sb)->s_flags & UFS_CG_MASK) == UFS_CG_44BSD)
103			ufs_clusteracct (sb, ucpi, blkno, 1);
104		fs32_add(sb, &ucg->cg_cs.cs_nbfree, 1);
105		uspi->cs_total.cs_nbfree++;
106		fs32_add(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nbfree, 1);
107		if (uspi->fs_magic != UFS2_MAGIC) {
108			unsigned cylno = ufs_cbtocylno (bbase);
109
110			fs16_add(sb, &ubh_cg_blks(ucpi, cylno,
111						  ufs_cbtorpos(bbase)), 1);
112			fs32_add(sb, &ubh_cg_blktot(ucpi, cylno), 1);
113		}
114	}
115	
116	ubh_mark_buffer_dirty (USPI_UBH(uspi));
117	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
118	if (sb->s_flags & SB_SYNCHRONOUS)
119		ubh_sync_block(UCPI_UBH(ucpi));
120	ufs_mark_sb_dirty(sb);
121
122	mutex_unlock(&UFS_SB(sb)->s_lock);
123	UFSD("EXIT\n");
124	return;
125
126failed:
127	mutex_unlock(&UFS_SB(sb)->s_lock);
128	UFSD("EXIT (FAILED)\n");
129	return;
130}
131
132/*
133 * Free 'count' fragments from fragment number 'fragment' (free whole blocks)
134 */
135void ufs_free_blocks(struct inode *inode, u64 fragment, unsigned count)
136{
137	struct super_block * sb;
138	struct ufs_sb_private_info * uspi;
139	struct ufs_cg_private_info * ucpi;
140	struct ufs_cylinder_group * ucg;
141	unsigned overflow, cgno, bit, end_bit, i;
142	u64 blkno;
143	
144	sb = inode->i_sb;
145	uspi = UFS_SB(sb)->s_uspi;
146
147	UFSD("ENTER, fragment %llu, count %u\n",
148	     (unsigned long long)fragment, count);
149	
150	if ((fragment & uspi->s_fpbmask) || (count & uspi->s_fpbmask)) {
151		ufs_error (sb, "ufs_free_blocks", "internal error, "
152			   "fragment %llu, count %u\n",
153			   (unsigned long long)fragment, count);
154		goto failed;
155	}
156
157	mutex_lock(&UFS_SB(sb)->s_lock);
158	
159do_more:
160	overflow = 0;
161	cgno = ufs_dtog(uspi, fragment);
162	bit = ufs_dtogd(uspi, fragment);
163	if (cgno >= uspi->s_ncg) {
164		ufs_panic (sb, "ufs_free_blocks", "freeing blocks are outside device");
165		goto failed_unlock;
166	}
167	end_bit = bit + count;
168	if (end_bit > uspi->s_fpg) {
169		overflow = bit + count - uspi->s_fpg;
170		count -= overflow;
171		end_bit -= overflow;
172	}
173
174	ucpi = ufs_load_cylinder (sb, cgno);
175	if (!ucpi) 
176		goto failed_unlock;
177	ucg = ubh_get_ucg (UCPI_UBH(ucpi));
178	if (!ufs_cg_chkmagic(sb, ucg)) {
179		ufs_panic (sb, "ufs_free_blocks", "internal error, bad magic number on cg %u", cgno);
180		goto failed_unlock;
181	}
182
183	for (i = bit; i < end_bit; i += uspi->s_fpb) {
184		blkno = ufs_fragstoblks(i);
185		if (ubh_isblockset(UCPI_UBH(ucpi), ucpi->c_freeoff, blkno)) {
186			ufs_error(sb, "ufs_free_blocks", "freeing free fragment");
187		}
188		ubh_setblock(UCPI_UBH(ucpi), ucpi->c_freeoff, blkno);
189		inode_sub_bytes(inode, uspi->s_fpb << uspi->s_fshift);
190		if ((UFS_SB(sb)->s_flags & UFS_CG_MASK) == UFS_CG_44BSD)
191			ufs_clusteracct (sb, ucpi, blkno, 1);
192
193		fs32_add(sb, &ucg->cg_cs.cs_nbfree, 1);
194		uspi->cs_total.cs_nbfree++;
195		fs32_add(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nbfree, 1);
196
197		if (uspi->fs_magic != UFS2_MAGIC) {
198			unsigned cylno = ufs_cbtocylno(i);
199
200			fs16_add(sb, &ubh_cg_blks(ucpi, cylno,
201						  ufs_cbtorpos(i)), 1);
202			fs32_add(sb, &ubh_cg_blktot(ucpi, cylno), 1);
203		}
204	}
205
206	ubh_mark_buffer_dirty (USPI_UBH(uspi));
207	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
208	if (sb->s_flags & SB_SYNCHRONOUS)
209		ubh_sync_block(UCPI_UBH(ucpi));
210
211	if (overflow) {
212		fragment += count;
213		count = overflow;
214		goto do_more;
215	}
216
217	ufs_mark_sb_dirty(sb);
218	mutex_unlock(&UFS_SB(sb)->s_lock);
219	UFSD("EXIT\n");
220	return;
221
222failed_unlock:
223	mutex_unlock(&UFS_SB(sb)->s_lock);
224failed:
225	UFSD("EXIT (FAILED)\n");
226	return;
227}
228
229/*
230 * Modify inode page cache in such way:
231 * have - blocks with b_blocknr equal to oldb...oldb+count-1
232 * get - blocks with b_blocknr equal to newb...newb+count-1
233 * also we suppose that oldb...oldb+count-1 blocks
234 * situated at the end of file.
235 *
236 * We can come here from ufs_writepage or ufs_prepare_write,
237 * locked_page is argument of these functions, so we already lock it.
238 */
239static void ufs_change_blocknr(struct inode *inode, sector_t beg,
240			       unsigned int count, sector_t oldb,
241			       sector_t newb, struct page *locked_page)
242{
243	const unsigned blks_per_page =
244		1 << (PAGE_SHIFT - inode->i_blkbits);
245	const unsigned mask = blks_per_page - 1;
246	struct address_space * const mapping = inode->i_mapping;
247	pgoff_t index, cur_index, last_index;
248	unsigned pos, j, lblock;
249	sector_t end, i;
250	struct page *page;
251	struct buffer_head *head, *bh;
252
253	UFSD("ENTER, ino %lu, count %u, oldb %llu, newb %llu\n",
254	      inode->i_ino, count,
255	     (unsigned long long)oldb, (unsigned long long)newb);
256
257	BUG_ON(!locked_page);
258	BUG_ON(!PageLocked(locked_page));
259
260	cur_index = locked_page->index;
261	end = count + beg;
262	last_index = end >> (PAGE_SHIFT - inode->i_blkbits);
263	for (i = beg; i < end; i = (i | mask) + 1) {
264		index = i >> (PAGE_SHIFT - inode->i_blkbits);
265
266		if (likely(cur_index != index)) {
267			page = ufs_get_locked_page(mapping, index);
268			if (!page)/* it was truncated */
269				continue;
270			if (IS_ERR(page)) {/* or EIO */
271				ufs_error(inode->i_sb, __func__,
272					  "read of page %llu failed\n",
273					  (unsigned long long)index);
274				continue;
275			}
276		} else
277			page = locked_page;
278
279		head = page_buffers(page);
280		bh = head;
281		pos = i & mask;
282		for (j = 0; j < pos; ++j)
283			bh = bh->b_this_page;
284
285
286		if (unlikely(index == last_index))
287			lblock = end & mask;
288		else
289			lblock = blks_per_page;
290
291		do {
292			if (j >= lblock)
293				break;
294			pos = (i - beg) + j;
295
296			if (!buffer_mapped(bh))
297					map_bh(bh, inode->i_sb, oldb + pos);
298			if (!buffer_uptodate(bh)) {
299				ll_rw_block(REQ_OP_READ, 0, 1, &bh);
300				wait_on_buffer(bh);
301				if (!buffer_uptodate(bh)) {
302					ufs_error(inode->i_sb, __func__,
303						  "read of block failed\n");
304					break;
305				}
306			}
307
308			UFSD(" change from %llu to %llu, pos %u\n",
309			     (unsigned long long)(pos + oldb),
310			     (unsigned long long)(pos + newb), pos);
311
312			bh->b_blocknr = newb + pos;
313			clean_bdev_bh_alias(bh);
314			mark_buffer_dirty(bh);
315			++j;
316			bh = bh->b_this_page;
317		} while (bh != head);
318
319		if (likely(cur_index != index))
320			ufs_put_locked_page(page);
321 	}
322	UFSD("EXIT\n");
323}
324
325static void ufs_clear_frags(struct inode *inode, sector_t beg, unsigned int n,
326			    int sync)
327{
328	struct buffer_head *bh;
329	sector_t end = beg + n;
330
331	for (; beg < end; ++beg) {
332		bh = sb_getblk(inode->i_sb, beg);
333		lock_buffer(bh);
334		memset(bh->b_data, 0, inode->i_sb->s_blocksize);
335		set_buffer_uptodate(bh);
336		mark_buffer_dirty(bh);
337		unlock_buffer(bh);
338		if (IS_SYNC(inode) || sync)
339			sync_dirty_buffer(bh);
340		brelse(bh);
341	}
342}
343
344u64 ufs_new_fragments(struct inode *inode, void *p, u64 fragment,
345			   u64 goal, unsigned count, int *err,
346			   struct page *locked_page)
347{
348	struct super_block * sb;
349	struct ufs_sb_private_info * uspi;
350	struct ufs_super_block_first * usb1;
351	unsigned cgno, oldcount, newcount;
352	u64 tmp, request, result;
353	
354	UFSD("ENTER, ino %lu, fragment %llu, goal %llu, count %u\n",
355	     inode->i_ino, (unsigned long long)fragment,
356	     (unsigned long long)goal, count);
357	
358	sb = inode->i_sb;
359	uspi = UFS_SB(sb)->s_uspi;
360	usb1 = ubh_get_usb_first(uspi);
361	*err = -ENOSPC;
362
363	mutex_lock(&UFS_SB(sb)->s_lock);
364	tmp = ufs_data_ptr_to_cpu(sb, p);
365
366	if (count + ufs_fragnum(fragment) > uspi->s_fpb) {
367		ufs_warning(sb, "ufs_new_fragments", "internal warning"
368			    " fragment %llu, count %u",
369			    (unsigned long long)fragment, count);
370		count = uspi->s_fpb - ufs_fragnum(fragment); 
371	}
372	oldcount = ufs_fragnum (fragment);
373	newcount = oldcount + count;
374
375	/*
376	 * Somebody else has just allocated our fragments
377	 */
378	if (oldcount) {
379		if (!tmp) {
380			ufs_error(sb, "ufs_new_fragments", "internal error, "
381				  "fragment %llu, tmp %llu\n",
382				  (unsigned long long)fragment,
383				  (unsigned long long)tmp);
384			mutex_unlock(&UFS_SB(sb)->s_lock);
385			return INVBLOCK;
386		}
387		if (fragment < UFS_I(inode)->i_lastfrag) {
388			UFSD("EXIT (ALREADY ALLOCATED)\n");
389			mutex_unlock(&UFS_SB(sb)->s_lock);
390			return 0;
391		}
392	}
393	else {
394		if (tmp) {
395			UFSD("EXIT (ALREADY ALLOCATED)\n");
396			mutex_unlock(&UFS_SB(sb)->s_lock);
397			return 0;
398		}
399	}
400
401	/*
402	 * There is not enough space for user on the device
403	 */
404	if (unlikely(ufs_freefrags(uspi) <= uspi->s_root_blocks)) {
405		if (!capable(CAP_SYS_RESOURCE)) {
406			mutex_unlock(&UFS_SB(sb)->s_lock);
407			UFSD("EXIT (FAILED)\n");
408			return 0;
409		}
410	}
411
412	if (goal >= uspi->s_size) 
413		goal = 0;
414	if (goal == 0) 
415		cgno = ufs_inotocg (inode->i_ino);
416	else
417		cgno = ufs_dtog(uspi, goal);
418	 
419	/*
420	 * allocate new fragment
421	 */
422	if (oldcount == 0) {
423		result = ufs_alloc_fragments (inode, cgno, goal, count, err);
424		if (result) {
425			ufs_clear_frags(inode, result + oldcount,
426					newcount - oldcount, locked_page != NULL);
427			*err = 0;
428			write_seqlock(&UFS_I(inode)->meta_lock);
429			ufs_cpu_to_data_ptr(sb, p, result);
 
 
430			UFS_I(inode)->i_lastfrag =
431				max(UFS_I(inode)->i_lastfrag, fragment + count);
432			write_sequnlock(&UFS_I(inode)->meta_lock);
433		}
434		mutex_unlock(&UFS_SB(sb)->s_lock);
435		UFSD("EXIT, result %llu\n", (unsigned long long)result);
436		return result;
437	}
438
439	/*
440	 * resize block
441	 */
442	result = ufs_add_fragments(inode, tmp, oldcount, newcount);
443	if (result) {
444		*err = 0;
445		read_seqlock_excl(&UFS_I(inode)->meta_lock);
446		UFS_I(inode)->i_lastfrag = max(UFS_I(inode)->i_lastfrag,
447						fragment + count);
448		read_sequnlock_excl(&UFS_I(inode)->meta_lock);
449		ufs_clear_frags(inode, result + oldcount, newcount - oldcount,
450				locked_page != NULL);
451		mutex_unlock(&UFS_SB(sb)->s_lock);
452		UFSD("EXIT, result %llu\n", (unsigned long long)result);
453		return result;
454	}
455
456	/*
457	 * allocate new block and move data
458	 */
459	if (fs32_to_cpu(sb, usb1->fs_optim) == UFS_OPTSPACE) {
 
460		request = newcount;
461		if (uspi->cs_total.cs_nffree < uspi->s_space_to_time)
462			usb1->fs_optim = cpu_to_fs32(sb, UFS_OPTTIME);
463	} else {
 
 
 
 
 
 
464		request = uspi->s_fpb;
465		if (uspi->cs_total.cs_nffree > uspi->s_time_to_space)
466			usb1->fs_optim = cpu_to_fs32(sb, UFS_OPTSPACE);
 
 
 
467	}
468	result = ufs_alloc_fragments (inode, cgno, goal, request, err);
469	if (result) {
470		ufs_clear_frags(inode, result + oldcount, newcount - oldcount,
471				locked_page != NULL);
472		mutex_unlock(&UFS_SB(sb)->s_lock);
473		ufs_change_blocknr(inode, fragment - oldcount, oldcount,
474				   uspi->s_sbbase + tmp,
475				   uspi->s_sbbase + result, locked_page);
476		*err = 0;
477		write_seqlock(&UFS_I(inode)->meta_lock);
478		ufs_cpu_to_data_ptr(sb, p, result);
 
 
479		UFS_I(inode)->i_lastfrag = max(UFS_I(inode)->i_lastfrag,
480						fragment + count);
481		write_sequnlock(&UFS_I(inode)->meta_lock);
482		if (newcount < request)
483			ufs_free_fragments (inode, result + newcount, request - newcount);
484		ufs_free_fragments (inode, tmp, oldcount);
485		UFSD("EXIT, result %llu\n", (unsigned long long)result);
486		return result;
487	}
488
489	mutex_unlock(&UFS_SB(sb)->s_lock);
490	UFSD("EXIT (FAILED)\n");
491	return 0;
492}		
493
494static bool try_add_frags(struct inode *inode, unsigned frags)
495{
496	unsigned size = frags * i_blocksize(inode);
497	spin_lock(&inode->i_lock);
498	__inode_add_bytes(inode, size);
499	if (unlikely((u32)inode->i_blocks != inode->i_blocks)) {
500		__inode_sub_bytes(inode, size);
501		spin_unlock(&inode->i_lock);
502		return false;
503	}
504	spin_unlock(&inode->i_lock);
505	return true;
506}
507
508static u64 ufs_add_fragments(struct inode *inode, u64 fragment,
509			     unsigned oldcount, unsigned newcount)
510{
511	struct super_block * sb;
512	struct ufs_sb_private_info * uspi;
513	struct ufs_cg_private_info * ucpi;
514	struct ufs_cylinder_group * ucg;
515	unsigned cgno, fragno, fragoff, count, fragsize, i;
516	
517	UFSD("ENTER, fragment %llu, oldcount %u, newcount %u\n",
518	     (unsigned long long)fragment, oldcount, newcount);
519	
520	sb = inode->i_sb;
521	uspi = UFS_SB(sb)->s_uspi;
522	count = newcount - oldcount;
523	
524	cgno = ufs_dtog(uspi, fragment);
525	if (fs32_to_cpu(sb, UFS_SB(sb)->fs_cs(cgno).cs_nffree) < count)
526		return 0;
527	if ((ufs_fragnum (fragment) + newcount) > uspi->s_fpb)
528		return 0;
529	ucpi = ufs_load_cylinder (sb, cgno);
530	if (!ucpi)
531		return 0;
532	ucg = ubh_get_ucg (UCPI_UBH(ucpi));
533	if (!ufs_cg_chkmagic(sb, ucg)) {
534		ufs_panic (sb, "ufs_add_fragments",
535			"internal error, bad magic number on cg %u", cgno);
536		return 0;
537	}
538
539	fragno = ufs_dtogd(uspi, fragment);
540	fragoff = ufs_fragnum (fragno);
541	for (i = oldcount; i < newcount; i++)
542		if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_freeoff, fragno + i))
543			return 0;
544
545	if (!try_add_frags(inode, count))
546		return 0;
547	/*
548	 * Block can be extended
549	 */
550	ucg->cg_time = ufs_get_seconds(sb);
551	for (i = newcount; i < (uspi->s_fpb - fragoff); i++)
552		if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_freeoff, fragno + i))
553			break;
554	fragsize = i - oldcount;
555	if (!fs32_to_cpu(sb, ucg->cg_frsum[fragsize]))
556		ufs_panic (sb, "ufs_add_fragments",
557			"internal error or corrupted bitmap on cg %u", cgno);
558	fs32_sub(sb, &ucg->cg_frsum[fragsize], 1);
559	if (fragsize != count)
560		fs32_add(sb, &ucg->cg_frsum[fragsize - count], 1);
561	for (i = oldcount; i < newcount; i++)
562		ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_freeoff, fragno + i);
563
564	fs32_sub(sb, &ucg->cg_cs.cs_nffree, count);
565	fs32_sub(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, count);
566	uspi->cs_total.cs_nffree -= count;
567	
568	ubh_mark_buffer_dirty (USPI_UBH(uspi));
569	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
570	if (sb->s_flags & SB_SYNCHRONOUS)
571		ubh_sync_block(UCPI_UBH(ucpi));
572	ufs_mark_sb_dirty(sb);
573
574	UFSD("EXIT, fragment %llu\n", (unsigned long long)fragment);
575	
576	return fragment;
577}
578
579#define UFS_TEST_FREE_SPACE_CG \
580	ucg = (struct ufs_cylinder_group *) UFS_SB(sb)->s_ucg[cgno]->b_data; \
581	if (fs32_to_cpu(sb, ucg->cg_cs.cs_nbfree)) \
582		goto cg_found; \
583	for (k = count; k < uspi->s_fpb; k++) \
584		if (fs32_to_cpu(sb, ucg->cg_frsum[k])) \
585			goto cg_found; 
586
587static u64 ufs_alloc_fragments(struct inode *inode, unsigned cgno,
588			       u64 goal, unsigned count, int *err)
589{
590	struct super_block * sb;
591	struct ufs_sb_private_info * uspi;
592	struct ufs_cg_private_info * ucpi;
593	struct ufs_cylinder_group * ucg;
594	unsigned oldcg, i, j, k, allocsize;
595	u64 result;
596	
597	UFSD("ENTER, ino %lu, cgno %u, goal %llu, count %u\n",
598	     inode->i_ino, cgno, (unsigned long long)goal, count);
599
600	sb = inode->i_sb;
601	uspi = UFS_SB(sb)->s_uspi;
602	oldcg = cgno;
603	
604	/*
605	 * 1. searching on preferred cylinder group
606	 */
607	UFS_TEST_FREE_SPACE_CG
608
609	/*
610	 * 2. quadratic rehash
611	 */
612	for (j = 1; j < uspi->s_ncg; j *= 2) {
613		cgno += j;
614		if (cgno >= uspi->s_ncg) 
615			cgno -= uspi->s_ncg;
616		UFS_TEST_FREE_SPACE_CG
617	}
618
619	/*
620	 * 3. brute force search
621	 * We start at i = 2 ( 0 is checked at 1.step, 1 at 2.step )
622	 */
623	cgno = (oldcg + 1) % uspi->s_ncg;
624	for (j = 2; j < uspi->s_ncg; j++) {
625		cgno++;
626		if (cgno >= uspi->s_ncg)
627			cgno = 0;
628		UFS_TEST_FREE_SPACE_CG
629	}
630	
631	UFSD("EXIT (FAILED)\n");
632	return 0;
633
634cg_found:
635	ucpi = ufs_load_cylinder (sb, cgno);
636	if (!ucpi)
637		return 0;
638	ucg = ubh_get_ucg (UCPI_UBH(ucpi));
639	if (!ufs_cg_chkmagic(sb, ucg)) 
640		ufs_panic (sb, "ufs_alloc_fragments",
641			"internal error, bad magic number on cg %u", cgno);
642	ucg->cg_time = ufs_get_seconds(sb);
643
644	if (count == uspi->s_fpb) {
645		result = ufs_alloccg_block (inode, ucpi, goal, err);
646		if (result == INVBLOCK)
647			return 0;
648		goto succed;
649	}
650
651	for (allocsize = count; allocsize < uspi->s_fpb; allocsize++)
652		if (fs32_to_cpu(sb, ucg->cg_frsum[allocsize]) != 0)
653			break;
654	
655	if (allocsize == uspi->s_fpb) {
656		result = ufs_alloccg_block (inode, ucpi, goal, err);
657		if (result == INVBLOCK)
658			return 0;
659		goal = ufs_dtogd(uspi, result);
660		for (i = count; i < uspi->s_fpb; i++)
661			ubh_setbit (UCPI_UBH(ucpi), ucpi->c_freeoff, goal + i);
662		i = uspi->s_fpb - count;
663
664		inode_sub_bytes(inode, i << uspi->s_fshift);
665		fs32_add(sb, &ucg->cg_cs.cs_nffree, i);
666		uspi->cs_total.cs_nffree += i;
667		fs32_add(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, i);
668		fs32_add(sb, &ucg->cg_frsum[i], 1);
669		goto succed;
670	}
671
672	result = ufs_bitmap_search (sb, ucpi, goal, allocsize);
673	if (result == INVBLOCK)
674		return 0;
675	if (!try_add_frags(inode, count))
676		return 0;
677	for (i = 0; i < count; i++)
678		ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_freeoff, result + i);
679	
680	fs32_sub(sb, &ucg->cg_cs.cs_nffree, count);
681	uspi->cs_total.cs_nffree -= count;
682	fs32_sub(sb, &UFS_SB(sb)->fs_cs(cgno).cs_nffree, count);
683	fs32_sub(sb, &ucg->cg_frsum[allocsize], 1);
684
685	if (count != allocsize)
686		fs32_add(sb, &ucg->cg_frsum[allocsize - count], 1);
687
688succed:
689	ubh_mark_buffer_dirty (USPI_UBH(uspi));
690	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
691	if (sb->s_flags & SB_SYNCHRONOUS)
692		ubh_sync_block(UCPI_UBH(ucpi));
693	ufs_mark_sb_dirty(sb);
694
695	result += cgno * uspi->s_fpg;
696	UFSD("EXIT3, result %llu\n", (unsigned long long)result);
697	return result;
698}
699
700static u64 ufs_alloccg_block(struct inode *inode,
701			     struct ufs_cg_private_info *ucpi,
702			     u64 goal, int *err)
703{
704	struct super_block * sb;
705	struct ufs_sb_private_info * uspi;
706	struct ufs_cylinder_group * ucg;
707	u64 result, blkno;
708
709	UFSD("ENTER, goal %llu\n", (unsigned long long)goal);
710
711	sb = inode->i_sb;
712	uspi = UFS_SB(sb)->s_uspi;
713	ucg = ubh_get_ucg(UCPI_UBH(ucpi));
714
715	if (goal == 0) {
716		goal = ucpi->c_rotor;
717		goto norot;
718	}
719	goal = ufs_blknum (goal);
720	goal = ufs_dtogd(uspi, goal);
721	
722	/*
723	 * If the requested block is available, use it.
724	 */
725	if (ubh_isblockset(UCPI_UBH(ucpi), ucpi->c_freeoff, ufs_fragstoblks(goal))) {
726		result = goal;
727		goto gotit;
728	}
729	
730norot:	
731	result = ufs_bitmap_search (sb, ucpi, goal, uspi->s_fpb);
732	if (result == INVBLOCK)
733		return INVBLOCK;
734	ucpi->c_rotor = result;
735gotit:
736	if (!try_add_frags(inode, uspi->s_fpb))
737		return 0;
738	blkno = ufs_fragstoblks(result);
739	ubh_clrblock (UCPI_UBH(ucpi), ucpi->c_freeoff, blkno);
740	if ((UFS_SB(sb)->s_flags & UFS_CG_MASK) == UFS_CG_44BSD)
741		ufs_clusteracct (sb, ucpi, blkno, -1);
742
743	fs32_sub(sb, &ucg->cg_cs.cs_nbfree, 1);
744	uspi->cs_total.cs_nbfree--;
745	fs32_sub(sb, &UFS_SB(sb)->fs_cs(ucpi->c_cgx).cs_nbfree, 1);
746
747	if (uspi->fs_magic != UFS2_MAGIC) {
748		unsigned cylno = ufs_cbtocylno((unsigned)result);
749
750		fs16_sub(sb, &ubh_cg_blks(ucpi, cylno,
751					  ufs_cbtorpos((unsigned)result)), 1);
752		fs32_sub(sb, &ubh_cg_blktot(ucpi, cylno), 1);
753	}
754	
755	UFSD("EXIT, result %llu\n", (unsigned long long)result);
756
757	return result;
758}
759
760static unsigned ubh_scanc(struct ufs_sb_private_info *uspi,
761			  struct ufs_buffer_head *ubh,
762			  unsigned begin, unsigned size,
763			  unsigned char *table, unsigned char mask)
764{
765	unsigned rest, offset;
766	unsigned char *cp;
767	
768
769	offset = begin & ~uspi->s_fmask;
770	begin >>= uspi->s_fshift;
771	for (;;) {
772		if ((offset + size) < uspi->s_fsize)
773			rest = size;
774		else
775			rest = uspi->s_fsize - offset;
776		size -= rest;
777		cp = ubh->bh[begin]->b_data + offset;
778		while ((table[*cp++] & mask) == 0 && --rest)
779			;
780		if (rest || !size)
781			break;
782		begin++;
783		offset = 0;
784	}
785	return (size + rest);
786}
787
788/*
789 * Find a block of the specified size in the specified cylinder group.
790 * @sp: pointer to super block
791 * @ucpi: pointer to cylinder group info
792 * @goal: near which block we want find new one
793 * @count: specified size
794 */
795static u64 ufs_bitmap_search(struct super_block *sb,
796			     struct ufs_cg_private_info *ucpi,
797			     u64 goal, unsigned count)
798{
799	/*
800	 * Bit patterns for identifying fragments in the block map
801	 * used as ((map & mask_arr) == want_arr)
802	 */
803	static const int mask_arr[9] = {
804		0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff
805	};
806	static const int want_arr[9] = {
807		0x0, 0x2, 0x6, 0xe, 0x1e, 0x3e, 0x7e, 0xfe, 0x1fe
808	};
809	struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
810	unsigned start, length, loc;
811	unsigned pos, want, blockmap, mask, end;
812	u64 result;
813
814	UFSD("ENTER, cg %u, goal %llu, count %u\n", ucpi->c_cgx,
815	     (unsigned long long)goal, count);
816
817	if (goal)
818		start = ufs_dtogd(uspi, goal) >> 3;
819	else
820		start = ucpi->c_frotor >> 3;
821		
822	length = ((uspi->s_fpg + 7) >> 3) - start;
823	loc = ubh_scanc(uspi, UCPI_UBH(ucpi), ucpi->c_freeoff + start, length,
824		(uspi->s_fpb == 8) ? ufs_fragtable_8fpb : ufs_fragtable_other,
825		1 << (count - 1 + (uspi->s_fpb & 7))); 
826	if (loc == 0) {
827		length = start + 1;
828		loc = ubh_scanc(uspi, UCPI_UBH(ucpi), ucpi->c_freeoff, length,
829				(uspi->s_fpb == 8) ? ufs_fragtable_8fpb :
830				ufs_fragtable_other,
831				1 << (count - 1 + (uspi->s_fpb & 7)));
832		if (loc == 0) {
833			ufs_error(sb, "ufs_bitmap_search",
834				  "bitmap corrupted on cg %u, start %u,"
835				  " length %u, count %u, freeoff %u\n",
836				  ucpi->c_cgx, start, length, count,
837				  ucpi->c_freeoff);
838			return INVBLOCK;
839		}
840		start = 0;
841	}
842	result = (start + length - loc) << 3;
843	ucpi->c_frotor = result;
844
845	/*
846	 * found the byte in the map
847	 */
848
849	for (end = result + 8; result < end; result += uspi->s_fpb) {
850		blockmap = ubh_blkmap(UCPI_UBH(ucpi), ucpi->c_freeoff, result);
851		blockmap <<= 1;
852		mask = mask_arr[count];
853		want = want_arr[count];
854		for (pos = 0; pos <= uspi->s_fpb - count; pos++) {
855			if ((blockmap & mask) == want) {
856				UFSD("EXIT, result %llu\n",
857				     (unsigned long long)result);
858				return result + pos;
859 			}
860			mask <<= 1;
861			want <<= 1;
862 		}
863 	}
864
865	ufs_error(sb, "ufs_bitmap_search", "block not in map on cg %u\n",
866		  ucpi->c_cgx);
867	UFSD("EXIT (FAILED)\n");
868	return INVBLOCK;
869}
870
871static void ufs_clusteracct(struct super_block * sb,
872	struct ufs_cg_private_info * ucpi, unsigned blkno, int cnt)
873{
874	struct ufs_sb_private_info * uspi;
875	int i, start, end, forw, back;
876	
877	uspi = UFS_SB(sb)->s_uspi;
878	if (uspi->s_contigsumsize <= 0)
879		return;
880
881	if (cnt > 0)
882		ubh_setbit(UCPI_UBH(ucpi), ucpi->c_clusteroff, blkno);
883	else
884		ubh_clrbit(UCPI_UBH(ucpi), ucpi->c_clusteroff, blkno);
885
886	/*
887	 * Find the size of the cluster going forward.
888	 */
889	start = blkno + 1;
890	end = start + uspi->s_contigsumsize;
891	if ( end >= ucpi->c_nclusterblks)
892		end = ucpi->c_nclusterblks;
893	i = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_clusteroff, end, start);
894	if (i > end)
895		i = end;
896	forw = i - start;
897	
898	/*
899	 * Find the size of the cluster going backward.
900	 */
901	start = blkno - 1;
902	end = start - uspi->s_contigsumsize;
903	if (end < 0 ) 
904		end = -1;
905	i = ubh_find_last_zero_bit (UCPI_UBH(ucpi), ucpi->c_clusteroff, start, end);
906	if ( i < end) 
907		i = end;
908	back = start - i;
909	
910	/*
911	 * Account for old cluster and the possibly new forward and
912	 * back clusters.
913	 */
914	i = back + forw + 1;
915	if (i > uspi->s_contigsumsize)
916		i = uspi->s_contigsumsize;
917	fs32_add(sb, (__fs32*)ubh_get_addr(UCPI_UBH(ucpi), ucpi->c_clustersumoff + (i << 2)), cnt);
918	if (back > 0)
919		fs32_sub(sb, (__fs32*)ubh_get_addr(UCPI_UBH(ucpi), ucpi->c_clustersumoff + (back << 2)), cnt);
920	if (forw > 0)
921		fs32_sub(sb, (__fs32*)ubh_get_addr(UCPI_UBH(ucpi), ucpi->c_clustersumoff + (forw << 2)), cnt);
922}
923
924
925static unsigned char ufs_fragtable_8fpb[] = {
926	0x00, 0x01, 0x01, 0x02, 0x01, 0x01, 0x02, 0x04, 0x01, 0x01, 0x01, 0x03, 0x02, 0x03, 0x04, 0x08,
927	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x02, 0x03, 0x03, 0x02, 0x04, 0x05, 0x08, 0x10,
928	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
929	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 0x04, 0x05, 0x05, 0x06, 0x08, 0x09, 0x10, 0x20,
930	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,	
931	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
932	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0A,
933	0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04, 0x08, 0x09, 0x09, 0x0A, 0x10, 0x11, 0x20, 0x40,
934	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
935	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
936	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
937	0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07, 0x05, 0x05, 0x05, 0x07, 0x09, 0x09, 0x11, 0x21,
938	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0A,
939	0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07, 0x02, 0x03, 0x03, 0x02, 0x06, 0x07, 0x0A, 0x12,
940	0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04, 0x05, 0x05, 0x05, 0x07, 0x06, 0x07, 0x04, 0x0C,
941	0x08, 0x09, 0x09, 0x0A, 0x09, 0x09, 0x0A, 0x0C, 0x10, 0x11, 0x11, 0x12, 0x20, 0x21, 0x40, 0x80,
942};
943
944static unsigned char ufs_fragtable_other[] = {
945	0x00, 0x16, 0x16, 0x2A, 0x16, 0x16, 0x26, 0x4E, 0x16, 0x16, 0x16, 0x3E, 0x2A, 0x3E, 0x4E, 0x8A,
946	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
947	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
948	0x2A, 0x3E, 0x3E, 0x2A, 0x3E, 0x3E, 0x2E, 0x6E, 0x3E, 0x3E, 0x3E, 0x3E, 0x2A, 0x3E, 0x6E, 0xAA,
949	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
950	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
951	0x26, 0x36, 0x36, 0x2E, 0x36, 0x36, 0x26, 0x6E, 0x36, 0x36, 0x36, 0x3E, 0x2E, 0x3E, 0x6E, 0xAE,
952	0x4E, 0x5E, 0x5E, 0x6E, 0x5E, 0x5E, 0x6E, 0x4E, 0x5E, 0x5E, 0x5E, 0x7E, 0x6E, 0x7E, 0x4E, 0xCE,
953	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
954	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
955	0x16, 0x16, 0x16, 0x3E, 0x16, 0x16, 0x36, 0x5E, 0x16, 0x16, 0x16, 0x3E, 0x3E, 0x3E, 0x5E, 0x9E,
956	0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x7E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x7E, 0xBE,
957	0x2A, 0x3E, 0x3E, 0x2A, 0x3E, 0x3E, 0x2E, 0x6E, 0x3E, 0x3E, 0x3E, 0x3E, 0x2A, 0x3E, 0x6E, 0xAA,
958	0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x7E,	0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x3E, 0x7E, 0xBE,
959	0x4E, 0x5E, 0x5E, 0x6E, 0x5E, 0x5E, 0x6E, 0x4E, 0x5E, 0x5E, 0x5E, 0x7E, 0x6E, 0x7E, 0x4E, 0xCE,
960	0x8A, 0x9E, 0x9E, 0xAA, 0x9E, 0x9E, 0xAE, 0xCE, 0x9E, 0x9E, 0x9E, 0xBE, 0xAA, 0xBE, 0xCE, 0x8A,
961};