[linux.git] / fs / affs / bitmap.c

/*
 *  linux/fs/affs/bitmap.c
 *
 *  (c) 1996 Hans-Joachim Widmaier
 *
 *  bitmap.c contains the code that handles all bitmap related stuff -
 *  block allocation, deallocation, calculation of free space.
 */

#include <linux/slab.h>
#include "affs.h"

u32
affs_count_free_blocks(struct super_block *sb)
{
	struct affs_bm_info *bm;
	u32 free;
	int i;

	pr_debug("%s()\n", __func__);

	if (sb->s_flags & MS_RDONLY)
		return 0;

	mutex_lock(&AFFS_SB(sb)->s_bmlock);

	bm = AFFS_SB(sb)->s_bitmap;
	free = 0;
	for (i = AFFS_SB(sb)->s_bmap_count; i > 0; bm++, i--)
		free += bm->bm_free;

	mutex_unlock(&AFFS_SB(sb)->s_bmlock);

	return free;
}

void
affs_free_block(struct super_block *sb, u32 block)
{
	struct affs_sb_info *sbi = AFFS_SB(sb);
	struct affs_bm_info *bm;
	struct buffer_head *bh;
	u32 blk, bmap, bit, mask, tmp;
	__be32 *data;

	pr_debug("%s(%u)\n", __func__, block);

	if (block > sbi->s_partition_size)
		goto err_range;

	blk     = block - sbi->s_reserved;
	bmap    = blk / sbi->s_bmap_bits;
	bit     = blk % sbi->s_bmap_bits;
	bm      = &sbi->s_bitmap[bmap];

	mutex_lock(&sbi->s_bmlock);

	bh = sbi->s_bmap_bh;
	if (sbi->s_last_bmap != bmap) {
		affs_brelse(bh);
		bh = affs_bread(sb, bm->bm_key);
		if (!bh)
			goto err_bh_read;
		sbi->s_bmap_bh = bh;
		sbi->s_last_bmap = bmap;
	}

	mask = 1 << (bit & 31);
	data = (__be32 *)bh->b_data + bit / 32 + 1;

	/* mark block free */
	tmp = be32_to_cpu(*data);
	if (tmp & mask)
		goto err_free;
	*data = cpu_to_be32(tmp | mask);

	/* fix checksum */
	tmp = be32_to_cpu(*(__be32 *)bh->b_data);
	*(__be32 *)bh->b_data = cpu_to_be32(tmp - mask);

	mark_buffer_dirty(bh);
	affs_mark_sb_dirty(sb);
	bm->bm_free++;

	mutex_unlock(&sbi->s_bmlock);
	return;

err_free:
	affs_warning(sb,"affs_free_block","Trying to free block %u which is already free", block);
	mutex_unlock(&sbi->s_bmlock);
	return;

err_bh_read:
	affs_error(sb,"affs_free_block","Cannot read bitmap block %u", bm->bm_key);
	sbi->s_bmap_bh = NULL;
	sbi->s_last_bmap = ~0;
	mutex_unlock(&sbi->s_bmlock);
	return;

err_range:
	affs_error(sb, "affs_free_block","Block %u outside partition", block);
}

/*
 * Allocate a block in the given allocation zone.
 * Since we have to byte-swap the bitmap on little-endian
 * machines, this is rather expensive. Therefore we will
 * preallocate up to 16 blocks from the same word, if
 * possible. We are not doing preallocations in the
 * header zone, though.
 */

u32
affs_alloc_block(struct inode *inode, u32 goal)
{
	struct super_block *sb;
	struct affs_sb_info *sbi;
	struct affs_bm_info *bm;
	struct buffer_head *bh;
	__be32 *data, *enddata;
	u32 blk, bmap, bit, mask, mask2, tmp;
	int i;

	sb = inode->i_sb;
	sbi = AFFS_SB(sb);

	pr_debug("balloc(inode=%lu,goal=%u): ", inode->i_ino, goal);

	if (AFFS_I(inode)->i_pa_cnt) {
		pr_debug("%d\n", AFFS_I(inode)->i_lastalloc+1);
		AFFS_I(inode)->i_pa_cnt--;
		return ++AFFS_I(inode)->i_lastalloc;
	}

	if (!goal || goal > sbi->s_partition_size) {
		if (goal)
			affs_warning(sb, "affs_balloc", "invalid goal %d", goal);
		//if (!AFFS_I(inode)->i_last_block)
		//	affs_warning(sb, "affs_balloc", "no last alloc block");
		goal = sbi->s_reserved;
	}

	blk = goal - sbi->s_reserved;
	bmap = blk / sbi->s_bmap_bits;
	bm = &sbi->s_bitmap[bmap];

	mutex_lock(&sbi->s_bmlock);

	if (bm->bm_free)
		goto find_bmap_bit;

find_bmap:
	/* search for the next bmap buffer with free bits */
	i = sbi->s_bmap_count;
	do {
		if (--i < 0)
			goto err_full;
		bmap++;
		bm++;
		if (bmap < sbi->s_bmap_count)
			continue;
		/* restart search at zero */
		bmap = 0;
		bm = sbi->s_bitmap;
	} while (!bm->bm_free);
	blk = bmap * sbi->s_bmap_bits;

find_bmap_bit:

	bh = sbi->s_bmap_bh;
	if (sbi->s_last_bmap != bmap) {
		affs_brelse(bh);
		bh = affs_bread(sb, bm->bm_key);
		if (!bh)
			goto err_bh_read;
		sbi->s_bmap_bh = bh;
		sbi->s_last_bmap = bmap;
	}

	/* find an unused block in this bitmap block */
	bit = blk % sbi->s_bmap_bits;
	data = (__be32 *)bh->b_data + bit / 32 + 1;
	enddata = (__be32 *)((u8 *)bh->b_data + sb->s_blocksize);
	mask = ~0UL << (bit & 31);
	blk &= ~31UL;

	tmp = be32_to_cpu(*data);
	if (tmp & mask)
		goto find_bit;

	/* scan the rest of the buffer */
	do {
		blk += 32;
		if (++data >= enddata)
			/* didn't find something, can only happen
			 * if scan didn't start at 0, try next bmap
			 */
			goto find_bmap;
	} while (!*data);
	tmp = be32_to_cpu(*data);
	mask = ~0;

find_bit:
	/* finally look for a free bit in the word */
	bit = ffs(tmp & mask) - 1;
	blk += bit + sbi->s_reserved;
	mask2 = mask = 1 << (bit & 31);
	AFFS_I(inode)->i_lastalloc = blk;

	/* prealloc as much as possible within this word */
	while ((mask2 <<= 1)) {
		if (!(tmp & mask2))
			break;
		AFFS_I(inode)->i_pa_cnt++;
		mask |= mask2;
	}
	bm->bm_free -= AFFS_I(inode)->i_pa_cnt + 1;

	*data = cpu_to_be32(tmp & ~mask);

	/* fix checksum */
	tmp = be32_to_cpu(*(__be32 *)bh->b_data);
	*(__be32 *)bh->b_data = cpu_to_be32(tmp + mask);

	mark_buffer_dirty(bh);
	affs_mark_sb_dirty(sb);

	mutex_unlock(&sbi->s_bmlock);

	pr_debug("%d\n", blk);
	return blk;

err_bh_read:
	affs_error(sb,"affs_read_block","Cannot read bitmap block %u", bm->bm_key);
	sbi->s_bmap_bh = NULL;
	sbi->s_last_bmap = ~0;
err_full:
	mutex_unlock(&sbi->s_bmlock);
	pr_debug("failed\n");
	return 0;
}

int affs_init_bitmap(struct super_block *sb, int *flags)
{
	struct affs_bm_info *bm;
	struct buffer_head *bmap_bh = NULL, *bh = NULL;
	__be32 *bmap_blk;
	u32 size, blk, end, offset, mask;
	int i, res = 0;
	struct affs_sb_info *sbi = AFFS_SB(sb);

	if (*flags & MS_RDONLY)
		return 0;

	if (!AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag) {
		pr_notice("Bitmap invalid - mounting %s read only\n", sb->s_id);
		*flags |= MS_RDONLY;
		return 0;
	}

	sbi->s_last_bmap = ~0;
	sbi->s_bmap_bh = NULL;
	sbi->s_bmap_bits = sb->s_blocksize * 8 - 32;
	sbi->s_bmap_count = (sbi->s_partition_size - sbi->s_reserved +
				 sbi->s_bmap_bits - 1) / sbi->s_bmap_bits;
	size = sbi->s_bmap_count * sizeof(*bm);
	bm = sbi->s_bitmap = kzalloc(size, GFP_KERNEL);
	if (!sbi->s_bitmap) {
		pr_err("Bitmap allocation failed\n");
		return -ENOMEM;
	}

	bmap_blk = (__be32 *)sbi->s_root_bh->b_data;
	blk = sb->s_blocksize / 4 - 49;
	end = blk + 25;

	for (i = sbi->s_bmap_count; i > 0; bm++, i--) {
		affs_brelse(bh);

		bm->bm_key = be32_to_cpu(bmap_blk[blk]);
		bh = affs_bread(sb, bm->bm_key);
		if (!bh) {
			pr_err("Cannot read bitmap\n");
			res = -EIO;
			goto out;
		}
		if (affs_checksum_block(sb, bh)) {
			pr_warn("Bitmap %u invalid - mounting %s read only.\n",
				bm->bm_key, sb->s_id);
			*flags |= MS_RDONLY;
			goto out;
		}
		pr_debug("read bitmap block %d: %d\n", blk, bm->bm_key);
		bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4);

		/* Don't try read the extension if this is the last block,
		 * but we also need the right bm pointer below
		 */
		if (++blk < end || i == 1)
			continue;
		if (bmap_bh)
			affs_brelse(bmap_bh);
		bmap_bh = affs_bread(sb, be32_to_cpu(bmap_blk[blk]));
		if (!bmap_bh) {
			pr_err("Cannot read bitmap extension\n");
			res = -EIO;
			goto out;
		}
		bmap_blk = (__be32 *)bmap_bh->b_data;
		blk = 0;
		end = sb->s_blocksize / 4 - 1;
	}

	offset = (sbi->s_partition_size - sbi->s_reserved) % sbi->s_bmap_bits;
	mask = ~(0xFFFFFFFFU << (offset & 31));
	pr_debug("last word: %d %d %d\n", offset, offset / 32 + 1, mask);
	offset = offset / 32 + 1;

	if (mask) {
		u32 old, new;

		/* Mark unused bits in the last word as allocated */
		old = be32_to_cpu(((__be32 *)bh->b_data)[offset]);
		new = old & mask;
		//if (old != new) {
			((__be32 *)bh->b_data)[offset] = cpu_to_be32(new);
			/* fix checksum */
			//new -= old;
			//old = be32_to_cpu(*(__be32 *)bh->b_data);
			//*(__be32 *)bh->b_data = cpu_to_be32(old - new);
			//mark_buffer_dirty(bh);
		//}
		/* correct offset for the bitmap count below */
		//offset++;
	}
	while (++offset < sb->s_blocksize / 4)
		((__be32 *)bh->b_data)[offset] = 0;
	((__be32 *)bh->b_data)[0] = 0;
	((__be32 *)bh->b_data)[0] = cpu_to_be32(-affs_checksum_block(sb, bh));
	mark_buffer_dirty(bh);

	/* recalculate bitmap count for last block */
	bm--;
	bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4);

out:
	affs_brelse(bh);
	affs_brelse(bmap_bh);
	return res;
}

void affs_free_bitmap(struct super_block *sb)
{
	struct affs_sb_info *sbi = AFFS_SB(sb);

	if (!sbi->s_bitmap)
		return;

	affs_brelse(sbi->s_bmap_bh);
	sbi->s_bmap_bh = NULL;
	sbi->s_last_bmap = ~0;
	kfree(sbi->s_bitmap);
	sbi->s_bitmap = NULL;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/affs/bitmap.c
	3	*
	4	* (c) 1996 Hans-Joachim Widmaier
	5	*
	6	* bitmap.c contains the code that handles all bitmap related stuff -
	7	* block allocation, deallocation, calculation of free space.
	8	*/
	9
5a0e3ad6	10	#include <linux/slab.h>
1da177e4 LT	11	#include "affs.h"
1da177e4 LT	12
1da177e4 LT	13	u32
	14	affs_count_free_blocks(struct super_block *sb)
	15	{
	16	struct affs_bm_info *bm;
	17	u32 free;
	18	int i;
	19
9606d9aa	20	pr_debug("%s()\n", __func__);
1da177e4 LT	21
	22	if (sb->s_flags & MS_RDONLY)
	23	return 0;
	24
7d135a5d	25	mutex_lock(&AFFS_SB(sb)->s_bmlock);
1da177e4 LT	26
	27	bm = AFFS_SB(sb)->s_bitmap;
	28	free = 0;
	29	for (i = AFFS_SB(sb)->s_bmap_count; i > 0; bm++, i--)
	30	free += bm->bm_free;
	31
7d135a5d	32	mutex_unlock(&AFFS_SB(sb)->s_bmlock);
1da177e4 LT	33
	34	return free;
	35	}
	36
	37	void
	38	affs_free_block(struct super_block *sb, u32 block)
	39	{
	40	struct affs_sb_info *sbi = AFFS_SB(sb);
	41	struct affs_bm_info *bm;
	42	struct buffer_head *bh;
	43	u32 blk, bmap, bit, mask, tmp;
	44	__be32 *data;
	45
9606d9aa	46	pr_debug("%s(%u)\n", __func__, block);
1da177e4 LT	47
	48	if (block > sbi->s_partition_size)
	49	goto err_range;
	50
	51	blk = block - sbi->s_reserved;
	52	bmap = blk / sbi->s_bmap_bits;
	53	bit = blk % sbi->s_bmap_bits;
	54	bm = &sbi->s_bitmap[bmap];
	55
7d135a5d	56	mutex_lock(&sbi->s_bmlock);
1da177e4 LT	57
	58	bh = sbi->s_bmap_bh;
	59	if (sbi->s_last_bmap != bmap) {
	60	affs_brelse(bh);
	61	bh = affs_bread(sb, bm->bm_key);
	62	if (!bh)
	63	goto err_bh_read;
	64	sbi->s_bmap_bh = bh;
	65	sbi->s_last_bmap = bmap;
	66	}
	67
	68	mask = 1 << (bit & 31);
	69	data = (__be32 *)bh->b_data + bit / 32 + 1;
	70
	71	/* mark block free */
	72	tmp = be32_to_cpu(*data);
	73	if (tmp & mask)
	74	goto err_free;
	75	*data = cpu_to_be32(tmp \| mask);
	76
	77	/* fix checksum */
	78	tmp = be32_to_cpu((__be32 )bh->b_data);
	79	(__be32 )bh->b_data = cpu_to_be32(tmp - mask);
	80
	81	mark_buffer_dirty(bh);
3dd84782	82	affs_mark_sb_dirty(sb);
1da177e4 LT	83	bm->bm_free++;
1da177e4 LT	84
7d135a5d	85	mutex_unlock(&sbi->s_bmlock);
1da177e4 LT	86	return;
	87
	88	err_free:
	89	affs_warning(sb,"affs_free_block","Trying to free block %u which is already free", block);
7d135a5d	90	mutex_unlock(&sbi->s_bmlock);
1da177e4 LT	91	return;
	92
	93	err_bh_read:
	94	affs_error(sb,"affs_free_block","Cannot read bitmap block %u", bm->bm_key);
	95	sbi->s_bmap_bh = NULL;
	96	sbi->s_last_bmap = ~0;
7d135a5d	97	mutex_unlock(&sbi->s_bmlock);
1da177e4 LT	98	return;
	99
	100	err_range:
	101	affs_error(sb, "affs_free_block","Block %u outside partition", block);
1da177e4 LT	102	}
	103
	104	/*
	105	* Allocate a block in the given allocation zone.
	106	* Since we have to byte-swap the bitmap on little-endian
3ad2f3fb	107	* machines, this is rather expensive. Therefore we will
1da177e4 LT	108	* preallocate up to 16 blocks from the same word, if
	109	* possible. We are not doing preallocations in the
	110	* header zone, though.
	111	*/
	112
	113	u32
	114	affs_alloc_block(struct inode *inode, u32 goal)
	115	{
	116	struct super_block *sb;
	117	struct affs_sb_info *sbi;
	118	struct affs_bm_info *bm;
	119	struct buffer_head *bh;
	120	__be32 data, enddata;
	121	u32 blk, bmap, bit, mask, mask2, tmp;
	122	int i;
	123
	124	sb = inode->i_sb;
	125	sbi = AFFS_SB(sb);
	126
9606d9aa	127	pr_debug("balloc(inode=%lu,goal=%u): ", inode->i_ino, goal);
1da177e4 LT	128
	129	if (AFFS_I(inode)->i_pa_cnt) {
	130	pr_debug("%d\n", AFFS_I(inode)->i_lastalloc+1);
	131	AFFS_I(inode)->i_pa_cnt--;
	132	return ++AFFS_I(inode)->i_lastalloc;
	133	}
	134
	135	if (!goal \|\| goal > sbi->s_partition_size) {
	136	if (goal)
	137	affs_warning(sb, "affs_balloc", "invalid goal %d", goal);
	138	//if (!AFFS_I(inode)->i_last_block)
	139	// affs_warning(sb, "affs_balloc", "no last alloc block");
	140	goal = sbi->s_reserved;
	141	}
	142
	143	blk = goal - sbi->s_reserved;
	144	bmap = blk / sbi->s_bmap_bits;
	145	bm = &sbi->s_bitmap[bmap];
	146
7d135a5d	147	mutex_lock(&sbi->s_bmlock);
1da177e4 LT	148
	149	if (bm->bm_free)
	150	goto find_bmap_bit;
	151
	152	find_bmap:
	153	/* search for the next bmap buffer with free bits */
	154	i = sbi->s_bmap_count;
	155	do {
	156	if (--i < 0)
	157	goto err_full;
	158	bmap++;
	159	bm++;
	160	if (bmap < sbi->s_bmap_count)
	161	continue;
	162	/* restart search at zero */
	163	bmap = 0;
	164	bm = sbi->s_bitmap;
	165	} while (!bm->bm_free);
	166	blk = bmap * sbi->s_bmap_bits;
	167
	168	find_bmap_bit:
	169
	170	bh = sbi->s_bmap_bh;
	171	if (sbi->s_last_bmap != bmap) {
	172	affs_brelse(bh);
	173	bh = affs_bread(sb, bm->bm_key);
	174	if (!bh)
	175	goto err_bh_read;
	176	sbi->s_bmap_bh = bh;
	177	sbi->s_last_bmap = bmap;
	178	}
	179
	180	/* find an unused block in this bitmap block */
	181	bit = blk % sbi->s_bmap_bits;
	182	data = (__be32 *)bh->b_data + bit / 32 + 1;
	183	enddata = (__be32 )((u8 )bh->b_data + sb->s_blocksize);
	184	mask = ~0UL << (bit & 31);
	185	blk &= ~31UL;
	186
	187	tmp = be32_to_cpu(*data);
	188	if (tmp & mask)
	189	goto find_bit;
	190
	191	/* scan the rest of the buffer */
	192	do {
	193	blk += 32;
	194	if (++data >= enddata)
	195	/* didn't find something, can only happen
	196	* if scan didn't start at 0, try next bmap
	197	*/
	198	goto find_bmap;
	199	} while (!*data);
	200	tmp = be32_to_cpu(*data);
	201	mask = ~0;
	202
	203	find_bit:
	204	/* finally look for a free bit in the word */
	205	bit = ffs(tmp & mask) - 1;
	206	blk += bit + sbi->s_reserved;
	207	mask2 = mask = 1 << (bit & 31);
	208	AFFS_I(inode)->i_lastalloc = blk;
	209
	210	/* prealloc as much as possible within this word */
	211	while ((mask2 <<= 1)) {
212	if (!(tmp & mask2))
213	break;
214	AFFS_I(inode)->i_pa_cnt++;
215	mask \|= mask2;
216	}
217	bm->bm_free -= AFFS_I(inode)->i_pa_cnt + 1;
218
219	*data = cpu_to_be32(tmp & ~mask);
220
221	/* fix checksum */
222	tmp = be32_to_cpu((__be32 )bh->b_data);
223	(__be32 )bh->b_data = cpu_to_be32(tmp + mask);
224
225	mark_buffer_dirty(bh);
3dd84782	226	affs_mark_sb_dirty(sb);
1da177e4	227
7d135a5d	228	mutex_unlock(&sbi->s_bmlock);
1da177e4 LT	229
	230	pr_debug("%d\n", blk);
	231	return blk;
	232
	233	err_bh_read:
	234	affs_error(sb,"affs_read_block","Cannot read bitmap block %u", bm->bm_key);
	235	sbi->s_bmap_bh = NULL;
	236	sbi->s_last_bmap = ~0;
	237	err_full:
7d135a5d	238	mutex_unlock(&sbi->s_bmlock);
1da177e4 LT	239	pr_debug("failed\n");
	240	return 0;
	241	}
	242
	243	int affs_init_bitmap(struct super_block sb, int flags)
	244	{
	245	struct affs_bm_info *bm;
	246	struct buffer_head bmap_bh = NULL, bh = NULL;
	247	__be32 *bmap_blk;
	248	u32 size, blk, end, offset, mask;
	249	int i, res = 0;
	250	struct affs_sb_info *sbi = AFFS_SB(sb);
	251
	252	if (*flags & MS_RDONLY)
	253	return 0;
	254
	255	if (!AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag) {
0158de12	256	pr_notice("Bitmap invalid - mounting %s read only\n", sb->s_id);
1da177e4 LT	257	*flags \|= MS_RDONLY;
	258	return 0;
	259	}
	260
	261	sbi->s_last_bmap = ~0;
	262	sbi->s_bmap_bh = NULL;
	263	sbi->s_bmap_bits = sb->s_blocksize * 8 - 32;
	264	sbi->s_bmap_count = (sbi->s_partition_size - sbi->s_reserved +
	265	sbi->s_bmap_bits - 1) / sbi->s_bmap_bits;
	266	size = sbi->s_bmap_count * sizeof(*bm);
b593e48d	267	bm = sbi->s_bitmap = kzalloc(size, GFP_KERNEL);
1da177e4	268	if (!sbi->s_bitmap) {
0158de12	269	pr_err("Bitmap allocation failed\n");
1da177e4 LT	270	return -ENOMEM;
1da177e4 LT	271	}
1da177e4 LT	272
	273	bmap_blk = (__be32 *)sbi->s_root_bh->b_data;
	274	blk = sb->s_blocksize / 4 - 49;
	275	end = blk + 25;
	276
	277	for (i = sbi->s_bmap_count; i > 0; bm++, i--) {
	278	affs_brelse(bh);
	279
	280	bm->bm_key = be32_to_cpu(bmap_blk[blk]);
	281	bh = affs_bread(sb, bm->bm_key);
	282	if (!bh) {
0158de12	283	pr_err("Cannot read bitmap\n");
1da177e4 LT	284	res = -EIO;
	285	goto out;
	286	}
	287	if (affs_checksum_block(sb, bh)) {
0158de12 FF	288	pr_warn("Bitmap %u invalid - mounting %s read only.\n",
0158de12 FF	289	bm->bm_key, sb->s_id);
1da177e4 LT	290	*flags \|= MS_RDONLY;
	291	goto out;
	292	}
9606d9aa	293	pr_debug("read bitmap block %d: %d\n", blk, bm->bm_key);
0121ad62	294	bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4);
1da177e4 LT	295
	296	/* Don't try read the extension if this is the last block,
	297	* but we also need the right bm pointer below
	298	*/
	299	if (++blk < end \|\| i == 1)
	300	continue;
	301	if (bmap_bh)
	302	affs_brelse(bmap_bh);
	303	bmap_bh = affs_bread(sb, be32_to_cpu(bmap_blk[blk]));
	304	if (!bmap_bh) {
0158de12	305	pr_err("Cannot read bitmap extension\n");
1da177e4 LT	306	res = -EIO;
	307	goto out;
	308	}
	309	bmap_blk = (__be32 *)bmap_bh->b_data;
	310	blk = 0;
	311	end = sb->s_blocksize / 4 - 1;
	312	}
	313
	314	offset = (sbi->s_partition_size - sbi->s_reserved) % sbi->s_bmap_bits;
	315	mask = ~(0xFFFFFFFFU << (offset & 31));
	316	pr_debug("last word: %d %d %d\n", offset, offset / 32 + 1, mask);
	317	offset = offset / 32 + 1;
	318
	319	if (mask) {
	320	u32 old, new;
	321
	322	/* Mark unused bits in the last word as allocated */
	323	old = be32_to_cpu(((__be32 *)bh->b_data)[offset]);
	324	new = old & mask;
	325	//if (old != new) {
	326	((__be32 *)bh->b_data)[offset] = cpu_to_be32(new);
	327	/* fix checksum */
	328	//new -= old;
	329	//old = be32_to_cpu((__be32 )bh->b_data);
	330	//(__be32 )bh->b_data = cpu_to_be32(old - new);
	331	//mark_buffer_dirty(bh);
	332	//}
	333	/* correct offset for the bitmap count below */
	334	//offset++;
	335	}
	336	while (++offset < sb->s_blocksize / 4)
	337	((__be32 *)bh->b_data)[offset] = 0;
	338	((__be32 *)bh->b_data)[0] = 0;
	339	((__be32 *)bh->b_data)[0] = cpu_to_be32(-affs_checksum_block(sb, bh));
	340	mark_buffer_dirty(bh);
	341
	342	/* recalculate bitmap count for last block */
	343	bm--;
0121ad62	344	bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4);
1da177e4 LT	345
	346	out:
	347	affs_brelse(bh);
	348	affs_brelse(bmap_bh);
	349	return res;
	350	}
	351
	352	void affs_free_bitmap(struct super_block *sb)
	353	{
	354	struct affs_sb_info *sbi = AFFS_SB(sb);
	355
	356	if (!sbi->s_bitmap)
	357	return;
	358
	359	affs_brelse(sbi->s_bmap_bh);
	360	sbi->s_bmap_bh = NULL;
	361	sbi->s_last_bmap = ~0;
	362	kfree(sbi->s_bitmap);
	363	sbi->s_bitmap = NULL;
	364	}