Re: [PATCH] btrfs: check alloc return value before use handle and struct

[Andi Kleen]

Steven Liu <lingjiujianke@xxxxxxxxx> writes:
> diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
> index e9103b3..230a131 100644
> --- a/fs/btrfs/dir-item.c
> +++ b/fs/btrfs/dir-item.c
> @@ -142,6 +142,8 @@ int btrfs_insert_dir_item(struct
> btrfs_trans_handle *trans, struct btrfs_root
>  	key.offset = btrfs_name_hash(name, name_len);
>
>  	path = btrfs_alloc_path();
> +	if (!path)
> +		return -ENOMEM;


The big problem is handling state unwind in all the callers, not adding
it to the low level code. I attempted it some time ago but it's hard.

Just spewing BUG_ON() all over on memory allocation failure is not
helpful imho, that's not better than simply having clean NULL pointer
faults.

-Andi

-- 
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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