btrfs: use nodesize everywhere, kill leafsize

The nodesize and leafsize were never of different values. Unify the
usage and make nodesize the one. Cleanup the redundant checks and
helpers.

Shaves a few bytes from .text:

  text    data     bss     dec     hex filename
852418   24560   23112  900090   dbbfa btrfs.ko.before
851074   24584   23112  898770   db6d2 btrfs.ko.after

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index ec32bea..508bbee 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1200,16 +1200,14 @@
 	kfree(writers);
 }
 
-static void __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
-			 u32 stripesize, struct btrfs_root *root,
-			 struct btrfs_fs_info *fs_info,
+static void __setup_root(u32 nodesize, u32 sectorsize, u32 stripesize,
+			 struct btrfs_root *root, struct btrfs_fs_info *fs_info,
 			 u64 objectid)
 {
 	root->node = NULL;
 	root->commit_root = NULL;
 	root->sectorsize = sectorsize;
 	root->nodesize = nodesize;
-	root->leafsize = leafsize;
 	root->stripesize = stripesize;
 	root->state = 0;
 	root->orphan_cleanup_state = 0;
@@ -1295,7 +1293,7 @@
 	root = btrfs_alloc_root(NULL);
 	if (!root)
 		return ERR_PTR(-ENOMEM);
-	__setup_root(4096, 4096, 4096, 4096, root, NULL, 1);
+	__setup_root(4096, 4096, 4096, root, NULL, 1);
 	set_bit(BTRFS_ROOT_DUMMY_ROOT, &root->state);
 	root->alloc_bytenr = 0;
 
@@ -1318,14 +1316,13 @@
 	if (!root)
 		return ERR_PTR(-ENOMEM);
 
-	__setup_root(tree_root->nodesize, tree_root->leafsize,
-		     tree_root->sectorsize, tree_root->stripesize,
-		     root, fs_info, objectid);
+	__setup_root(tree_root->nodesize, tree_root->sectorsize,
+		tree_root->stripesize, root, fs_info, objectid);
 	root->root_key.objectid = objectid;
 	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
 	root->root_key.offset = 0;
 
-	leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
+	leaf = btrfs_alloc_free_block(trans, root, root->nodesize,
 				      0, objectid, NULL, 0, 0, 0);
 	if (IS_ERR(leaf)) {
 		ret = PTR_ERR(leaf);
@@ -1396,9 +1393,9 @@
 	if (!root)
 		return ERR_PTR(-ENOMEM);
 
-	__setup_root(tree_root->nodesize, tree_root->leafsize,
-		     tree_root->sectorsize, tree_root->stripesize,
-		     root, fs_info, BTRFS_TREE_LOG_OBJECTID);
+	__setup_root(tree_root->nodesize, tree_root->sectorsize,
+		     tree_root->stripesize, root, fs_info,
+		     BTRFS_TREE_LOG_OBJECTID);
 
 	root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
 	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
@@ -1413,7 +1410,7 @@
 	 * updated (along with back refs to the log tree).
 	 */
 
-	leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
+	leaf = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
 				      BTRFS_TREE_LOG_OBJECTID, NULL,
 				      0, 0, 0);
 	if (IS_ERR(leaf)) {
@@ -1465,7 +1462,7 @@
 	btrfs_set_stack_inode_generation(inode_item, 1);
 	btrfs_set_stack_inode_size(inode_item, 3);
 	btrfs_set_stack_inode_nlink(inode_item, 1);
-	btrfs_set_stack_inode_nbytes(inode_item, root->leafsize);
+	btrfs_set_stack_inode_nbytes(inode_item, root->nodesize);
 	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 
 	btrfs_set_root_node(&log_root->root_item, log_root->node);
@@ -1498,9 +1495,8 @@
 		goto alloc_fail;
 	}
 
-	__setup_root(tree_root->nodesize, tree_root->leafsize,
-		     tree_root->sectorsize, tree_root->stripesize,
-		     root, fs_info, key->objectid);
+	__setup_root(tree_root->nodesize, tree_root->sectorsize,
+		tree_root->stripesize, root, fs_info, key->objectid);
 
 	ret = btrfs_find_root(tree_root, key, path,
 			      &root->root_item, &root->root_key);
@@ -1511,7 +1507,7 @@
 	}
 
 	generation = btrfs_root_generation(&root->root_item);
-	blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
+	blocksize = root->nodesize;
 	root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 				     blocksize, generation);
 	if (!root->node) {
@@ -2143,7 +2139,6 @@
 {
 	u32 sectorsize;
 	u32 nodesize;
-	u32 leafsize;
 	u32 blocksize;
 	u32 stripesize;
 	u64 generation;
@@ -2389,7 +2384,7 @@
 		goto fail_alloc;
 	}
 
-	__setup_root(4096, 4096, 4096, 4096, tree_root,
+	__setup_root(4096, 4096, 4096, tree_root,
 		     fs_info, BTRFS_ROOT_TREE_OBJECTID);
 
 	invalidate_bdev(fs_devices->latest_bdev);
@@ -2469,19 +2464,22 @@
 		goto fail_alloc;
 	}
 
-	if (btrfs_super_leafsize(disk_super) !=
+	/*
+	 * Leafsize and nodesize were always equal, this is only a sanity check.
+	 */
+	if (le32_to_cpu(disk_super->__unused_leafsize) !=
 	    btrfs_super_nodesize(disk_super)) {
 		printk(KERN_ERR "BTRFS: couldn't mount because metadata "
 		       "blocksizes don't match.  node %d leaf %d\n",
 		       btrfs_super_nodesize(disk_super),
-		       btrfs_super_leafsize(disk_super));
+		       le32_to_cpu(disk_super->__unused_leafsize));
 		err = -EINVAL;
 		goto fail_alloc;
 	}
-	if (btrfs_super_leafsize(disk_super) > BTRFS_MAX_METADATA_BLOCKSIZE) {
+	if (btrfs_super_nodesize(disk_super) > BTRFS_MAX_METADATA_BLOCKSIZE) {
 		printk(KERN_ERR "BTRFS: couldn't mount because metadata "
 		       "blocksize (%d) was too large\n",
-		       btrfs_super_leafsize(disk_super));
+		       btrfs_super_nodesize(disk_super));
 		err = -EINVAL;
 		goto fail_alloc;
 	}
@@ -2498,17 +2496,16 @@
 	 * flag our filesystem as having big metadata blocks if
 	 * they are bigger than the page size
 	 */
-	if (btrfs_super_leafsize(disk_super) > PAGE_CACHE_SIZE) {
+	if (btrfs_super_nodesize(disk_super) > PAGE_CACHE_SIZE) {
 		if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
 			printk(KERN_INFO "BTRFS: flagging fs with big metadata feature\n");
 		features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
 	}
 
 	nodesize = btrfs_super_nodesize(disk_super);
-	leafsize = btrfs_super_leafsize(disk_super);
 	sectorsize = btrfs_super_sectorsize(disk_super);
 	stripesize = btrfs_super_stripesize(disk_super);
-	fs_info->dirty_metadata_batch = leafsize * (1 + ilog2(nr_cpu_ids));
+	fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
 	fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
 
 	/*
@@ -2516,7 +2513,7 @@
 	 * extent buffers for the same range.  It leads to corruptions
 	 */
 	if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
-	    (sectorsize != leafsize)) {
+	    (sectorsize != nodesize)) {
 		printk(KERN_WARNING "BTRFS: unequal leaf/node/sector sizes "
 				"are not allowed for mixed block groups on %s\n",
 				sb->s_id);
@@ -2615,7 +2612,6 @@
 				    4 * 1024 * 1024 / PAGE_CACHE_SIZE);
 
 	tree_root->nodesize = nodesize;
-	tree_root->leafsize = leafsize;
 	tree_root->sectorsize = sectorsize;
 	tree_root->stripesize = stripesize;
 
@@ -2642,12 +2638,11 @@
 		goto fail_sb_buffer;
 	}
 
-	blocksize = btrfs_level_size(tree_root,
-				     btrfs_super_chunk_root_level(disk_super));
+	blocksize = tree_root->nodesize;
 	generation = btrfs_super_chunk_root_generation(disk_super);
 
-	__setup_root(nodesize, leafsize, sectorsize, stripesize,
-		     chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
+	__setup_root(nodesize, sectorsize, stripesize, chunk_root,
+		     fs_info, BTRFS_CHUNK_TREE_OBJECTID);
 
 	chunk_root->node = read_tree_block(chunk_root,
 					   btrfs_super_chunk_root(disk_super),
@@ -2684,8 +2679,7 @@
 	}
 
 retry_root_backup:
-	blocksize = btrfs_level_size(tree_root,
-				     btrfs_super_root_level(disk_super));
+	blocksize = tree_root->nodesize;
 	generation = btrfs_super_generation(disk_super);
 
 	tree_root->node = read_tree_block(tree_root,
@@ -2859,9 +2853,7 @@
 			err = -EIO;
 			goto fail_qgroup;
 		}
-		blocksize =
-		     btrfs_level_size(tree_root,
-				      btrfs_super_log_root_level(disk_super));
+		blocksize = tree_root->nodesize;
 
 		log_tree_root = btrfs_alloc_root(fs_info);
 		if (!log_tree_root) {
@@ -2869,7 +2861,7 @@
 			goto fail_qgroup;
 		}
 
-		__setup_root(nodesize, leafsize, sectorsize, stripesize,
+		__setup_root(nodesize, sectorsize, stripesize,
 			     log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
 
 		log_tree_root->node = read_tree_block(tree_root, bytenr,
@@ -4008,8 +4000,8 @@
 		clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
 		while (start <= end) {
 			eb = btrfs_find_tree_block(root, start,
-						   root->leafsize);
-			start += root->leafsize;
+						   root->nodesize);
+			start += root->nodesize;
 			if (!eb)
 				continue;
 			wait_on_extent_buffer_writeback(eb);