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>

2 files changed, 12 insertions, 23 deletions

diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c
index f7275176305e..f09a6f6d3ac0 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;
 
diff --git a/fs/reiserfs/resize.c b/fs/reiserfs/resize.c
index 3bec2f96242a..66f1cda83a81 100644
--- a/fs/reiserfs/resize.c
+++ b/fs/reiserfs/resize.c
@@ -143,7 +143,6 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
                         mark_buffer_dirty(bh);
                         sync_dirty_buffer(bh);
                         // update bitmap_info stuff
-                        bitmap[i].first_zero_hint = 1;
                         bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
                         brelse(bh);
                 }
@@ -173,8 +172,6 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
         for (i = block_r; i < s->s_blocksize * 8; i++)
                 reiserfs_test_and_clear_le_bit(i, bh->b_data);
         info->free_count += s->s_blocksize * 8 - block_r;
-        if (!info->first_zero_hint)
-                info->first_zero_hint = block_r;
 
         journal_mark_dirty(&th, s, bh);
         brelse(bh);
@@ -196,9 +193,6 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
         brelse(bh);
 
         info->free_count -= s->s_blocksize * 8 - block_r_new;
-        /* Extreme case where last bitmap is the only valid block in itself. */
-        if (!info->free_count)
-                info->first_zero_hint = 0;
         /* update super */
         reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
         free_blocks = SB_FREE_BLOCKS(s);