From 4d20851d3757ba5bece263a4c8c5a2bd4983cb5d Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Thu, 18 Oct 2007 23:39:26 -0700 Subject: 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/reiserfs/bitmap.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) (limited to 'fs/reiserfs/bitmap.c') diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c index f7275176305..f09a6f6d3ac 100644 --- a/fs/reiserfs/bitmap.c +++ b/fs/reiserfs/bitmap.c @@ -273,7 +273,7 @@ static inline int block_group_used(struct super_block *s, u32 id) * to make a better decision. This favors long-term performace gain * with a better on-disk layout vs. a short term gain of skipping the * read and potentially having a bad placement. */ - if (info->first_zero_hint == 0) { + if (info->free_count == UINT_MAX) { struct buffer_head *bh = reiserfs_read_bitmap_block(s, bm); brelse(bh); } @@ -1214,27 +1214,22 @@ void reiserfs_cache_bitmap_metadata(struct super_block *sb, { unsigned long *cur = (unsigned long *)(bh->b_data + bh->b_size); - info->first_zero_hint = 1 << (sb->s_blocksize_bits + 3); + /* The first bit must ALWAYS be 1 */ + BUG_ON(!reiserfs_test_le_bit(0, (unsigned long *)bh->b_data)); + + info->free_count = 0; while (--cur >= (unsigned long *)bh->b_data) { - int base = ((char *)cur - bh->b_data) << 3; + int i; /* 0 and ~0 are special, we can optimize for them */ - if (*cur == 0) { - info->first_zero_hint = base; + if (*cur == 0) info->free_count += BITS_PER_LONG; - } else if (*cur != ~0L) { /* A mix, investigate */ - int b; - for (b = BITS_PER_LONG - 1; b >= 0; b--) { - if (!reiserfs_test_le_bit(b, cur)) { - info->first_zero_hint = base + b; + else if (*cur != ~0L) /* A mix, investigate */ + for (i = BITS_PER_LONG - 1; i >= 0; i--) + if (!reiserfs_test_le_bit(i, cur)) info->free_count++; - } - } - } } - /* The first bit must ALWAYS be 1 */ - BUG_ON(info->first_zero_hint == 0); } struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb, @@ -1264,7 +1259,7 @@ struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb, BUG_ON(!buffer_uptodate(bh)); BUG_ON(atomic_read(&bh->b_count) == 0); - if (info->first_zero_hint == 0) + if (info->free_count == UINT_MAX) reiserfs_cache_bitmap_metadata(sb, bh, info); } @@ -1279,7 +1274,7 @@ int reiserfs_init_bitmap_cache(struct super_block *sb) if (bitmap == NULL) return -ENOMEM; - memset(bitmap, 0, sizeof (*bitmap) * SB_BMAP_NR(sb)); + memset(bitmap, 0xff, sizeof(*bitmap) * SB_BMAP_NR(sb)); SB_AP_BITMAP(sb) = bitmap; -- cgit v1.2.3