Re: [PATCH 1/2] f2fs: add f2fs_bug_on() to detect potential bug

[Jaegeuk Kim <jaegeuk@kernel.org>]

On 05/12, Chao Yu wrote:
> Add f2fs_bug_on() to check whether memory preallocation will fail or
> not after radix_tree_preload(GFP_NOFS | __GFP_NOFAIL).

Are we getting a bug?

> 
> Signed-off-by: Chao Yu <chao@kernel.org>
> ---
>  fs/f2fs/checkpoint.c | 4 +++-
>  fs/f2fs/node.c       | 7 +++++--
>  2 files changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index e7907858eb70..3f223bade520 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -504,6 +504,7 @@ static void __add_ino_entry(struct f2fs_sb_info *sbi, nid_t ino,
>  {
>  	struct inode_management *im = &sbi->im[type];
>  	struct ino_entry *e = NULL, *new = NULL;
> +	int ret;
>  
>  	if (type == FLUSH_INO) {
>  		rcu_read_lock();
> @@ -516,7 +517,8 @@ static void __add_ino_entry(struct f2fs_sb_info *sbi, nid_t ino,
>  		new = f2fs_kmem_cache_alloc(ino_entry_slab,
>  						GFP_NOFS, true, NULL);
>  
> -	radix_tree_preload(GFP_NOFS | __GFP_NOFAIL);
> +	ret = radix_tree_preload(GFP_NOFS | __GFP_NOFAIL);
> +	f2fs_bug_on(sbi, ret);
>  
>  	spin_lock(&im->ino_lock);
>  	e = radix_tree_lookup(&im->ino_root, ino);
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index 3f6b8037d25f..88d3032236cb 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -2309,7 +2309,7 @@ static bool add_free_nid(struct f2fs_sb_info *sbi,
>  	struct f2fs_nm_info *nm_i = NM_I(sbi);
>  	struct free_nid *i, *e;
>  	struct nat_entry *ne;
> -	int err = -EINVAL;
> +	int err;
>  	bool ret = false;
>  
>  	/* 0 nid should not be used */
> @@ -2323,7 +2323,10 @@ static bool add_free_nid(struct f2fs_sb_info *sbi,
>  	i->nid = nid;
>  	i->state = FREE_NID;
>  
> -	radix_tree_preload(GFP_NOFS | __GFP_NOFAIL);
> +	err = radix_tree_preload(GFP_NOFS | __GFP_NOFAIL);
> +	f2fs_bug_on(sbi, err);
> +
> +	err = -EINVAL;
>  
>  	spin_lock(&nm_i->nid_list_lock);
>  
> -- 
> 2.49.0