Btrfs: make a delayed_block_rsv for the delayed item insertion

I've been hitting warnings in use_block_rsv when running the delayed insertion
stuff.  It's because we will readjust global block rsv based on what is in use,
which means we could end up discarding reservations that are for the delayed
insertion stuff.  So instead create a seperate block rsv for the delayed
insertion stuff.  This will also make it easier to debug problems with the
delayed insertion reservations since we will know that only the delayed
insertion code touches this block_rsv.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/ctree.h

@@ -957,6 +957,8 @@ struct btrfs_fs_info {
 	struct btrfs_block_rsv trans_block_rsv;
 	/* block reservation for chunk tree */
 	struct btrfs_block_rsv chunk_block_rsv;
+	/* block reservation for delayed operations */
+	struct btrfs_block_rsv delayed_block_rsv;
 
 	struct btrfs_block_rsv empty_block_rsv;
 

fs/btrfs/delayed-inode.c

@@ -591,7 +591,7 @@ static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
 		return 0;
 
 	src_rsv = trans->block_rsv;
-	dst_rsv = &root->fs_info->global_block_rsv;
+	dst_rsv = &root->fs_info->delayed_block_rsv;
 
 	num_bytes = btrfs_calc_trans_metadata_size(root, 1);
 	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
@@ -609,7 +609,7 @@ static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
 	if (!item->bytes_reserved)
 		return;
 
-	rsv = &root->fs_info->global_block_rsv;
+	rsv = &root->fs_info->delayed_block_rsv;
 	btrfs_block_rsv_release(root, rsv,
 				item->bytes_reserved);
 }
@@ -628,7 +628,7 @@ static int btrfs_delayed_inode_reserve_metadata(
 		return 0;
 
 	src_rsv = trans->block_rsv;
-	dst_rsv = &root->fs_info->global_block_rsv;
+	dst_rsv = &root->fs_info->delayed_block_rsv;
 
 	num_bytes = btrfs_calc_trans_metadata_size(root, 1);
 	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
@@ -646,7 +646,7 @@ static void btrfs_delayed_inode_release_metadata(struct btrfs_root *root,
 	if (!node->bytes_reserved)
 		return;
 
-	rsv = &root->fs_info->global_block_rsv;
+	rsv = &root->fs_info->delayed_block_rsv;
 	btrfs_block_rsv_release(root, rsv,
 				node->bytes_reserved);
 	node->bytes_reserved = 0;
@@ -1026,7 +1026,7 @@ int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
 	path->leave_spinning = 1;
 
 	block_rsv = trans->block_rsv;
-	trans->block_rsv = &root->fs_info->global_block_rsv;
+	trans->block_rsv = &root->fs_info->delayed_block_rsv;
 
 	delayed_root = btrfs_get_delayed_root(root);
 
@@ -1069,7 +1069,7 @@ static int __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
 	path->leave_spinning = 1;
 
 	block_rsv = trans->block_rsv;
-	trans->block_rsv = &node->root->fs_info->global_block_rsv;
+	trans->block_rsv = &node->root->fs_info->delayed_block_rsv;
 
 	ret = btrfs_insert_delayed_items(trans, path, node->root, node);
 	if (!ret)
@@ -1149,7 +1149,7 @@ static void btrfs_async_run_delayed_node_done(struct btrfs_work *work)
 		goto free_path;
 
 	block_rsv = trans->block_rsv;
-	trans->block_rsv = &root->fs_info->global_block_rsv;
+	trans->block_rsv = &root->fs_info->delayed_block_rsv;
 
 	ret = btrfs_insert_delayed_items(trans, path, root, delayed_node);
 	if (!ret)

fs/btrfs/disk-io.c

@@ -1891,6 +1891,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	btrfs_init_block_rsv(&fs_info->trans_block_rsv);
 	btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
 	btrfs_init_block_rsv(&fs_info->empty_block_rsv);
+	btrfs_init_block_rsv(&fs_info->delayed_block_rsv);
 	atomic_set(&fs_info->nr_async_submits, 0);
 	atomic_set(&fs_info->async_delalloc_pages, 0);
 	atomic_set(&fs_info->async_submit_draining, 0);

fs/btrfs/extent-tree.c

@@ -3914,6 +3914,7 @@ static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
 	fs_info->delalloc_block_rsv.space_info = space_info;
 	fs_info->trans_block_rsv.space_info = space_info;
 	fs_info->empty_block_rsv.space_info = space_info;
+	fs_info->delayed_block_rsv.space_info = space_info;
 
 	fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
 	fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
@@ -3933,6 +3934,8 @@ static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
 	WARN_ON(fs_info->trans_block_rsv.reserved > 0);
 	WARN_ON(fs_info->chunk_block_rsv.size > 0);
 	WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
+	WARN_ON(fs_info->delayed_block_rsv.size > 0);
+	WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
 }
 
 void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,