Btrfs: Update on disk i_size only after pending ordered extents are done

This changes the ordered data code to update i_size after the extent
is on disk.  An on disk i_size is maintained in the in-memory btrfs inode
structures, and this is updated as extents finish.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 47a008c..baf4601 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -542,6 +542,7 @@
 	add_pending_csums(trans, inode, ordered_extent->file_offset,
 			  &ordered_extent->list);
 
+	btrfs_ordered_update_i_size(inode, ordered_extent);
 	btrfs_remove_ordered_extent(inode, ordered_extent);
 	/* once for us */
 	btrfs_put_ordered_extent(ordered_extent);
@@ -792,7 +793,7 @@
 	inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
 	inode->i_uid = btrfs_inode_uid(leaf, inode_item);
 	inode->i_gid = btrfs_inode_gid(leaf, inode_item);
-	inode->i_size = btrfs_inode_size(leaf, inode_item);
+	btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
 
 	tspec = btrfs_inode_atime(inode_item);
 	inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
@@ -860,7 +861,7 @@
 {
 	btrfs_set_inode_uid(leaf, item, inode->i_uid);
 	btrfs_set_inode_gid(leaf, item, inode->i_gid);
-	btrfs_set_inode_size(leaf, item, inode->i_size);
+	btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
 	btrfs_set_inode_mode(leaf, item, inode->i_mode);
 	btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
 
@@ -982,7 +983,7 @@
 err:
 	btrfs_free_path(path);
 	if (!ret) {
-		dir->i_size -= name_len * 2;
+		btrfs_i_size_write(dir, dir->i_size - name_len * 2);
 		dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 		btrfs_update_inode(trans, root, dir);
 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
@@ -1044,7 +1045,7 @@
 	/* now the directory is empty */
 	err = btrfs_unlink_trans(trans, root, dir, dentry);
 	if (!err) {
-		inode->i_size = 0;
+		btrfs_i_size_write(inode, 0);
 	}
 
 	nr = trans->blocks_used;
@@ -1089,7 +1090,6 @@
 	int extent_type = -1;
 	u64 mask = root->sectorsize - 1;
 
-	btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
 	btrfs_drop_extent_cache(inode, inode->i_size & (~mask), (u64)-1);
 	path = btrfs_alloc_path();
 	path->reada = -1;
@@ -1427,7 +1427,7 @@
 		goto no_delete;
 	}
 
-	inode->i_size = 0;
+	btrfs_i_size_write(inode, 0);
 	trans = btrfs_start_transaction(root, 1);
 
 	btrfs_set_trans_block_group(trans, inode);
@@ -1561,6 +1561,7 @@
 	inode->i_ino = args->ino;
 	BTRFS_I(inode)->root = args->root;
 	BTRFS_I(inode)->delalloc_bytes = 0;
+	BTRFS_I(inode)->disk_i_size = 0;
 	extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
 	extent_io_tree_init(&BTRFS_I(inode)->io_tree,
 			     inode->i_mapping, GFP_NOFS);
@@ -1869,6 +1870,7 @@
 			     inode->i_mapping, GFP_NOFS);
 	mutex_init(&BTRFS_I(inode)->csum_mutex);
 	BTRFS_I(inode)->delalloc_bytes = 0;
+	BTRFS_I(inode)->disk_i_size = 0;
 	BTRFS_I(inode)->root = root;
 
 	if (mode & S_IFDIR)
@@ -1964,7 +1966,8 @@
 					     dentry->d_parent->d_inode->i_ino);
 		}
 		parent_inode = dentry->d_parent->d_inode;
-		parent_inode->i_size += dentry->d_name.len * 2;
+		btrfs_i_size_write(parent_inode, parent_inode->i_size +
+				   dentry->d_name.len * 2);
 		parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
 		ret = btrfs_update_inode(trans, root,
 					 dentry->d_parent->d_inode);
@@ -2092,6 +2095,7 @@
 				     inode->i_mapping, GFP_NOFS);
 		mutex_init(&BTRFS_I(inode)->csum_mutex);
 		BTRFS_I(inode)->delalloc_bytes = 0;
+		BTRFS_I(inode)->disk_i_size = 0;
 		BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
 	}
 	dir->i_sb->s_dirt = 1;
@@ -2199,7 +2203,7 @@
 	inode->i_fop = &btrfs_dir_file_operations;
 	btrfs_set_trans_block_group(trans, inode);
 
-	inode->i_size = 0;
+	btrfs_i_size_write(inode, 0);
 	err = btrfs_update_inode(trans, root, inode);
 	if (err)
 		goto out_fail;
@@ -2756,6 +2760,7 @@
 	int ret;
 	struct btrfs_trans_handle *trans;
 	unsigned long nr;
+	u64 mask = root->sectorsize - 1;
 
 	if (!S_ISREG(inode->i_mode))
 		return;
@@ -2766,6 +2771,8 @@
 
 	trans = btrfs_start_transaction(root, 1);
 	btrfs_set_trans_block_group(trans, inode);
+	btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
+	btrfs_i_size_write(inode, inode->i_size);
 
 	/* FIXME, add redo link to tree so we don't leak on crash */
 	ret = btrfs_truncate_in_trans(trans, root, inode,
@@ -2821,7 +2828,7 @@
 	ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
 				     new_dirid);
 	inode->i_nlink = 1;
-	inode->i_size = 0;
+	btrfs_i_size_write(inode, 0);
 
 	return btrfs_update_inode(trans, new_root, inode);
 }
@@ -3069,6 +3076,7 @@
 				     inode->i_mapping, GFP_NOFS);
 		mutex_init(&BTRFS_I(inode)->csum_mutex);
 		BTRFS_I(inode)->delalloc_bytes = 0;
+		BTRFS_I(inode)->disk_i_size = 0;
 		BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
 	}
 	dir->i_sb->s_dirt = 1;
@@ -3103,7 +3111,7 @@
 	inode->i_op = &btrfs_symlink_inode_operations;
 	inode->i_mapping->a_ops = &btrfs_symlink_aops;
 	inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
-	inode->i_size = name_len - 1;
+	btrfs_i_size_write(inode, name_len - 1);
 	err = btrfs_update_inode(trans, root, inode);
 	if (err)
 		drop_inode = 1;