reiserfs: remove first_zero_hint
The first_zero_hint metadata caching was never actually used, and it's of dubious optimization quality. This patch removes it. It doesn't actually shrink the size of the reiserfs_bitmap_info struct, since that doesn't work with block sizes larger than 8K. There was a big fixme in there, and with all the work lately in allowing block size > page size, I might as well kill the fixme as well. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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@ -273,7 +273,7 @@ static inline int block_group_used(struct super_block *s, u32 id)
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* to make a better decision. This favors long-term performace gain
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* with a better on-disk layout vs. a short term gain of skipping the
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* read and potentially having a bad placement. */
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if (info->first_zero_hint == 0) {
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if (info->free_count == UINT_MAX) {
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struct buffer_head *bh = reiserfs_read_bitmap_block(s, bm);
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brelse(bh);
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}
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@ -1214,27 +1214,22 @@ void reiserfs_cache_bitmap_metadata(struct super_block *sb,
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{
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unsigned long *cur = (unsigned long *)(bh->b_data + bh->b_size);
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info->first_zero_hint = 1 << (sb->s_blocksize_bits + 3);
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/* The first bit must ALWAYS be 1 */
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BUG_ON(!reiserfs_test_le_bit(0, (unsigned long *)bh->b_data));
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info->free_count = 0;
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while (--cur >= (unsigned long *)bh->b_data) {
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int base = ((char *)cur - bh->b_data) << 3;
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int i;
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/* 0 and ~0 are special, we can optimize for them */
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if (*cur == 0) {
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info->first_zero_hint = base;
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if (*cur == 0)
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info->free_count += BITS_PER_LONG;
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} else if (*cur != ~0L) { /* A mix, investigate */
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int b;
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for (b = BITS_PER_LONG - 1; b >= 0; b--) {
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if (!reiserfs_test_le_bit(b, cur)) {
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info->first_zero_hint = base + b;
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else if (*cur != ~0L) /* A mix, investigate */
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for (i = BITS_PER_LONG - 1; i >= 0; i--)
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if (!reiserfs_test_le_bit(i, cur))
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info->free_count++;
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}
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}
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}
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}
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/* The first bit must ALWAYS be 1 */
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BUG_ON(info->first_zero_hint == 0);
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}
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struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb,
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@ -1264,7 +1259,7 @@ struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb,
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BUG_ON(!buffer_uptodate(bh));
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BUG_ON(atomic_read(&bh->b_count) == 0);
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if (info->first_zero_hint == 0)
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if (info->free_count == UINT_MAX)
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reiserfs_cache_bitmap_metadata(sb, bh, info);
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}
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@ -1279,7 +1274,7 @@ int reiserfs_init_bitmap_cache(struct super_block *sb)
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if (bitmap == NULL)
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return -ENOMEM;
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memset(bitmap, 0, sizeof (*bitmap) * SB_BMAP_NR(sb));
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memset(bitmap, 0xff, sizeof(*bitmap) * SB_BMAP_NR(sb));
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SB_AP_BITMAP(sb) = bitmap;
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@ -143,7 +143,6 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
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mark_buffer_dirty(bh);
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sync_dirty_buffer(bh);
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// update bitmap_info stuff
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bitmap[i].first_zero_hint = 1;
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bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
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brelse(bh);
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}
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@ -173,8 +172,6 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
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for (i = block_r; i < s->s_blocksize * 8; i++)
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reiserfs_test_and_clear_le_bit(i, bh->b_data);
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info->free_count += s->s_blocksize * 8 - block_r;
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if (!info->first_zero_hint)
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info->first_zero_hint = block_r;
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journal_mark_dirty(&th, s, bh);
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brelse(bh);
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@ -196,9 +193,6 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
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brelse(bh);
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info->free_count -= s->s_blocksize * 8 - block_r_new;
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/* Extreme case where last bitmap is the only valid block in itself. */
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if (!info->free_count)
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info->first_zero_hint = 0;
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/* update super */
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reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
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free_blocks = SB_FREE_BLOCKS(s);
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@ -265,9 +265,7 @@ enum journal_state_bits {
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typedef __u32(*hashf_t) (const signed char *, int);
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struct reiserfs_bitmap_info {
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// FIXME: Won't work with block sizes > 8K
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__u16 first_zero_hint;
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__u16 free_count;
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__u32 free_count;
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};
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struct proc_dir_entry;
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