[PATCH] ufs: right block allocation

* After block allocation, we map it on the same "address" as 8 others
  blocks

* We nullify block several times: once in ufs/block.c and once in
  block_*write_full_page, and use different "caches" for this.

Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/ufs/balloc.c

@@ -223,18 +223,6 @@ void ufs_free_blocks (struct inode * inode, unsigned fragment, unsigned count) {
 }
 
 
-
-#define NULLIFY_FRAGMENTS \
-	for (i = oldcount; i < newcount; i++) { \
-		bh = sb_getblk(sb, result + i); \
-		memset (bh->b_data, 0, sb->s_blocksize); \
-		set_buffer_uptodate(bh); \
-		mark_buffer_dirty (bh); \
-		if (IS_SYNC(inode)) \
-			sync_dirty_buffer(bh); \
-		brelse (bh); \
-	}
-
 unsigned ufs_new_fragments (struct inode * inode, __fs32 * p, unsigned fragment,
 	unsigned goal, unsigned count, int * err )
 {
@@ -312,7 +300,6 @@ unsigned ufs_new_fragments (struct inode * inode, __fs32 * p, unsigned fragment,
 			*err = 0;
 			inode->i_blocks += count << uspi->s_nspfshift;
 			UFS_I(inode)->i_lastfrag = max_t(u32, UFS_I(inode)->i_lastfrag, fragment + count);
-			NULLIFY_FRAGMENTS
 		}
 		unlock_super(sb);
 		UFSD(("EXIT, result %u\n", result))
@@ -327,7 +314,6 @@ unsigned ufs_new_fragments (struct inode * inode, __fs32 * p, unsigned fragment,
 		*err = 0;
 		inode->i_blocks += count << uspi->s_nspfshift;
 		UFS_I(inode)->i_lastfrag = max_t(u32, UFS_I(inode)->i_lastfrag, fragment + count);
-		NULLIFY_FRAGMENTS
 		unlock_super(sb);
 		UFSD(("EXIT, result %u\n", result))
 		return result;
@@ -379,7 +365,6 @@ unsigned ufs_new_fragments (struct inode * inode, __fs32 * p, unsigned fragment,
 		*err = 0;
 		inode->i_blocks += count << uspi->s_nspfshift;
 		UFS_I(inode)->i_lastfrag = max_t(u32, UFS_I(inode)->i_lastfrag, fragment + count);
-		NULLIFY_FRAGMENTS
 		unlock_super(sb);
 		if (newcount < request)
 			ufs_free_fragments (inode, result + newcount, request - newcount);

fs/ufs/inode.c

@@ -161,6 +161,17 @@ u64  ufs_frag_map(struct inode *inode, sector_t frag)
 	return ret;
 }
 
+static void ufs_clear_block(struct inode *inode, struct buffer_head *bh)
+{
+	lock_buffer(bh);
+	memset(bh->b_data, 0, inode->i_sb->s_blocksize);
+	set_buffer_uptodate(bh);
+	mark_buffer_dirty(bh);
+	unlock_buffer(bh);
+	if (IS_SYNC(inode))
+		sync_dirty_buffer(bh);
+}
+
 static struct buffer_head * ufs_inode_getfrag (struct inode *inode,
 	unsigned int fragment, unsigned int new_fragment,
 	unsigned int required, int *err, int metadata, long *phys, int *new)
@@ -204,7 +215,7 @@ static struct buffer_head * ufs_inode_getfrag (struct inode *inode,
 			brelse (result);
 			goto repeat;
 		} else {
-			*phys = tmp;
+			*phys = tmp + blockoff;
 			return NULL;
 		}
 	}
@@ -259,14 +270,11 @@ static struct buffer_head * ufs_inode_getfrag (struct inode *inode,
 		return NULL;
 	}
 
-	/* The nullification of framgents done in ufs/balloc.c is
-	 * something I don't have the stomache to move into here right
-	 * now. -DaveM
-	 */
 	if (metadata) {
 		result = sb_getblk(inode->i_sb, tmp + blockoff);
+		ufs_clear_block(inode, result);
 	} else {
-		*phys = tmp;
+		*phys = tmp + blockoff;
 		result = NULL;
 		*err = 0;
 		*new = 1;
@@ -333,7 +341,7 @@ static struct buffer_head * ufs_block_getfrag (struct inode *inode,
 			brelse (result);
 			goto repeat;
 		} else {
-			*phys = tmp;
+			*phys = tmp + blockoff;
 			goto out;
 		}
 	}
@@ -349,14 +357,12 @@ static struct buffer_head * ufs_block_getfrag (struct inode *inode,
 		goto out;
 	}		
 
-	/* The nullification of framgents done in ufs/balloc.c is
-	 * something I don't have the stomache to move into here right
-	 * now. -DaveM
-	 */
+
 	if (metadata) {
 		result = sb_getblk(sb, tmp + blockoff);
+		ufs_clear_block(inode, result);
 	} else {
-		*phys = tmp;
+		*phys = tmp + blockoff;
 		*new = 1;
 	}