Re: [PATCH] btrfs: Fix btrfs_find_create_tree_block() testing

[Mike Rapoport <rppt@linux.ibm.com>]

Hi,

On Tue, Dec 03, 2019 at 12:33:04PM +0300, Dan Carpenter wrote:
> The btrfs_find_create_tree_block() uses alloc_dummy_extent_buffer() for
> testing and alloc_extent_buffer() for production.  The problem is that
> the test code returns NULL and the production code returns error
> pointers.  The callers only check for error pointers.
> 
> I have changed alloc_dummy_extent_buffer() to return error pointers and

nit:		alloc_test_extent_buffer()

> updated the two callers which use it directly.
> 
> Fixes: faa2dbf004e8 ("Btrfs: add sanity tests for new qgroup accounting code")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
>  fs/btrfs/extent_io.c                   | 6 ++++--
>  fs/btrfs/tests/free-space-tree-tests.c | 4 ++--
>  fs/btrfs/tests/qgroup-tests.c          | 4 ++--
>  3 files changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index eb8bd0258360..2f4802f405a2 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -5074,12 +5074,14 @@ struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
>  		return eb;
>  	eb = alloc_dummy_extent_buffer(fs_info, start);
>  	if (!eb)
> -		return NULL;
> +		return ERR_PTR(-ENOMEM);
>  	eb->fs_info = fs_info;
>  again:
>  	ret = radix_tree_preload(GFP_NOFS);
> -	if (ret)
> +	if (ret) {
> +		exists = ERR_PTR(ret);
>  		goto free_eb;
> +	}
>  	spin_lock(&fs_info->buffer_lock);
>  	ret = radix_tree_insert(&fs_info->buffer_radix,
>  				start >> PAGE_SHIFT, eb);
> diff --git a/fs/btrfs/tests/free-space-tree-tests.c b/fs/btrfs/tests/free-space-tree-tests.c
> index 1a846bf6e197..914eea5ba6a7 100644
> --- a/fs/btrfs/tests/free-space-tree-tests.c
> +++ b/fs/btrfs/tests/free-space-tree-tests.c
> @@ -452,9 +452,9 @@ static int run_test(test_func_t test_func, int bitmaps, u32 sectorsize,
>  	root->fs_info->tree_root = root;
>  
>  	root->node = alloc_test_extent_buffer(root->fs_info, nodesize);
> -	if (!root->node) {
> +	if (IS_ERR(root->node)) {
>  		test_std_err(TEST_ALLOC_EXTENT_BUFFER);
> -		ret = -ENOMEM;
> +		ret = PTR_ERR(root->node);
>  		goto out;
>  	}
>  	btrfs_set_header_level(root->node, 0);
> diff --git a/fs/btrfs/tests/qgroup-tests.c b/fs/btrfs/tests/qgroup-tests.c
> index 09aaca1efd62..ac035a6fa003 100644
> --- a/fs/btrfs/tests/qgroup-tests.c
> +++ b/fs/btrfs/tests/qgroup-tests.c
> @@ -484,9 +484,9 @@ int btrfs_test_qgroups(u32 sectorsize, u32 nodesize)
>  	 * *cough*backref walking code*cough*
>  	 */
>  	root->node = alloc_test_extent_buffer(root->fs_info, nodesize);
> -	if (!root->node) {
> +	if (IS_ERR(root->node)) {
>  		test_err("couldn't allocate dummy buffer");
> -		ret = -ENOMEM;
> +		ret = PTR_ERR(root->node);
>  		goto out;
>  	}
>  	btrfs_set_header_level(root->node, 0);
> -- 
> 2.11.0
> 

-- 
Sincerely yours,
Mike.