1 files changed, 66 insertions, 17 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 418c6a2ad7d8..b6031ce474f7 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -75,6 +75,23 @@ void btrfs_put_transaction(struct btrfs_transaction *transaction)
 			list_del_init(&em->list);
 			free_extent_map(em);
 		}
+		/*
+		 * If any block groups are found in ->deleted_bgs then it's
+		 * because the transaction was aborted and a commit did not
+		 * happen (things failed before writing the new superblock
+		 * and calling btrfs_finish_extent_commit()), so we can not
+		 * discard the physical locations of the block groups.
+		 */
+		while (!list_empty(&transaction->deleted_bgs)) {
+			struct btrfs_block_group_cache *cache;
+
+			cache = list_first_entry(&transaction->deleted_bgs,
+						 struct btrfs_block_group_cache,
+						 bg_list);
+			list_del_init(&cache->bg_list);
+			btrfs_put_block_group_trimming(cache);
+			btrfs_put_block_group(cache);
+		}
 		kmem_cache_free(btrfs_transaction_cachep, transaction);
 	}
 }
@@ -274,7 +291,6 @@ loop:
 	cur_trans->num_dirty_bgs = 0;
 	spin_lock_init(&cur_trans->dirty_bgs_lock);
 	INIT_LIST_HEAD(&cur_trans->deleted_bgs);
-	spin_lock_init(&cur_trans->deleted_bgs_lock);
 	spin_lock_init(&cur_trans->dropped_roots_lock);
 	list_add_tail(&cur_trans->list, &fs_info->trans_list);
 	extent_io_tree_init(&cur_trans->dirty_pages,
@@ -592,6 +608,38 @@ struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
 	return start_transaction(root, num_items, TRANS_START,
 				 BTRFS_RESERVE_FLUSH_ALL);
 }
+struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
+					struct btrfs_root *root,
+					unsigned int num_items,
+					int min_factor)
+{
+	struct btrfs_trans_handle *trans;
+	u64 num_bytes;
+	int ret;
+
+	trans = btrfs_start_transaction(root, num_items);
+	if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
+		return trans;
+
+	trans = btrfs_start_transaction(root, 0);
+	if (IS_ERR(trans))
+		return trans;
+
+	num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
+	ret = btrfs_cond_migrate_bytes(root->fs_info,
+				       &root->fs_info->trans_block_rsv,
+				       num_bytes,
+				       min_factor);
+	if (ret) {
+		btrfs_end_transaction(trans, root);
+		return ERR_PTR(ret);
+	}
+
+	trans->block_rsv = &root->fs_info->trans_block_rsv;
+	trans->bytes_reserved = num_bytes;
+
+	return trans;
+}
 
 struct btrfs_trans_handle *btrfs_start_transaction_lflush(
 					struct btrfs_root *root,
@@ -603,17 +651,20 @@ struct btrfs_trans_handle *btrfs_start_transaction_lflush(
 
 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root)
 {
-	return start_transaction(root, 0, TRANS_JOIN, 0);
+	return start_transaction(root, 0, TRANS_JOIN,
+				 BTRFS_RESERVE_NO_FLUSH);
 }
 
 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root)
 {
-	return start_transaction(root, 0, TRANS_JOIN_NOLOCK, 0);
+	return start_transaction(root, 0, TRANS_JOIN_NOLOCK,
+				 BTRFS_RESERVE_NO_FLUSH);
 }
 
 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root)
 {
-	return start_transaction(root, 0, TRANS_USERSPACE, 0);
+	return start_transaction(root, 0, TRANS_USERSPACE,
+				 BTRFS_RESERVE_NO_FLUSH);
 }
 
 /*
@@ -631,7 +682,8 @@ struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root
  */
 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root)
 {
-	return start_transaction(root, 0, TRANS_ATTACH, 0);
+	return start_transaction(root, 0, TRANS_ATTACH,
+				 BTRFS_RESERVE_NO_FLUSH);
 }
 
 /*
@@ -646,7 +698,8 @@ btrfs_attach_transaction_barrier(struct btrfs_root *root)
 {
 	struct btrfs_trans_handle *trans;
 
-	trans = start_transaction(root, 0, TRANS_ATTACH, 0);
+	trans = start_transaction(root, 0, TRANS_ATTACH,
+				  BTRFS_RESERVE_NO_FLUSH);
 	if (IS_ERR(trans) && PTR_ERR(trans) == -ENOENT)
 		btrfs_wait_for_commit(root, 0);
 
@@ -1288,17 +1341,11 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 	u64 root_flags;
 	uuid_le new_uuid;
 
-	path = btrfs_alloc_path();
-	if (!path) {
-		pending->error = -ENOMEM;
-		return 0;
-	}
+	ASSERT(pending->path);
+	path = pending->path;
 
-	new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
-	if (!new_root_item) {
-		pending->error = -ENOMEM;
-		goto root_item_alloc_fail;
-	}
+	ASSERT(pending->root_item);
+	new_root_item = pending->root_item;
 
 	pending->error = btrfs_find_free_objectid(tree_root, &objectid);
 	if (pending->error)
@@ -1531,8 +1578,10 @@ clear_skip_qgroup:
 	btrfs_clear_skip_qgroup(trans);
 no_free_objectid:
 	kfree(new_root_item);
-root_item_alloc_fail:
+	pending->root_item = NULL;
 	btrfs_free_path(path);
+	pending->path = NULL;
+
 	return ret;
 }