Btrfs: fix memory leaks after transaction is aborted (7785a663) · Commits · 戴 / test

When a transaction is aborted, or its commit fails before writing the new superblock and calling btrfs_finish_extent_commit(), we leak reference counts on the block groups attached to the transaction's delete_bgs list, because btrfs_finish_extent_commit() is never called for those two cases. Fix this by dropping their references at btrfs_put_transaction(), which is called when transactions are aborted (by making the transaction kthread commit the transaction) or if their commits fail. Signed-off-by:

Filipe Manana <fdmanana@suse.com>

fs/btrfs/transaction.c

+17 −0

Original line number	Diff line number	Diff line
		@@ -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);
		}
		}

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