Re: [f2fs-dev] [PATCH] f2fs: add a function to move nid

[Chao Yu]

On 2017/10/28 19:03, Fan Li wrote:
> This patch add a new function to move nid from one state to another.
> Move operation is heavily used, by adding a new function for it 
> we can cut down some branches from several flow.
> 
> 
> Signed-off-by: Fan li <fanofcode.li@xxxxxxxxxxx>
> ---
>  fs/f2fs/node.c | 51 ++++++++++++++++++++++++++++++---------------------
>  1 file changed, 30 insertions(+), 21 deletions(-)
> 
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index ac629d6..8116b50
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -1763,15 +1763,13 @@ static struct free_nid *__lookup_free_nid_list(struct f2fs_nm_info *nm_i,
>  }
>  
>  static int __insert_free_nid(struct f2fs_sb_info *sbi,
> -			struct free_nid *i, enum nid_state state, bool new)
> +			struct free_nid *i, enum nid_state state)
>  {
>  	struct f2fs_nm_info *nm_i = NM_I(sbi);
>  
> -	if (new) {
> -		int err = radix_tree_insert(&nm_i->free_nid_root, i->nid, i);
> -		if (err)
> -			return err;
> -	}
> +	int err = radix_tree_insert(&nm_i->free_nid_root, i->nid, i);
> +	if (err)
> +		return err;
>  
>  	f2fs_bug_on(sbi, state != i->state);
>  	nm_i->nid_cnt[state]++;
> @@ -1781,7 +1779,7 @@ static int __insert_free_nid(struct f2fs_sb_info *sbi,
>  }
>  
>  static void __remove_free_nid(struct f2fs_sb_info *sbi,
> -			struct free_nid *i, enum nid_state state, bool reuse)
> +			struct free_nid *i, enum nid_state state)
>  {
>  	struct f2fs_nm_info *nm_i = NM_I(sbi);
>  
> @@ -1789,8 +1787,23 @@ static void __remove_free_nid(struct f2fs_sb_info *sbi,
>  	nm_i->nid_cnt[state]--;
>  	if (state == FREE_NID)
>  		list_del(&i->list);
> -	if (!reuse)
> -		radix_tree_delete(&nm_i->free_nid_root, i->nid);
> +	radix_tree_delete(&nm_i->free_nid_root, i->nid);
> +}
> +
> +static void __move_free_nid(struct f2fs_sb_info *sbi, struct free_nid *i,
> +			enum nid_state org_state, enum nid_state dst_state)
> +{
> +	struct f2fs_nm_info *nm_i = NM_I(sbi);
> +
> +	f2fs_bug_on(sbi, org_state != i->state);
> +	i->state = dst_state;
> +	nm_i->nid_cnt[org_state]--;
> +	nm_i->nid_cnt[dst_state]++;
> +
> +	if (org_state == FREE_NID)

Welcome back to community, Fan. :)

Minor, how about "if (dst_stat == PREALLOC_NID)" ?

Otherwise this patch looks good to me, anyway, you can add:

Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx>

Thanks,

> +		list_del(&i->list);
> +	else if (dst_state == FREE_NID)
> +		list_add_tail(&i->list, &nm_i->free_nid_list);
>  }
>  
>  /* return if the nid is recognized as free */
> @@ -1850,7 +1863,7 @@ static bool add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build)
>  		}
>  	}
>  	ret = true;
> -	err = __insert_free_nid(sbi, i, FREE_NID, true);
> +	err = __insert_free_nid(sbi, i, FREE_NID);
>  err_out:
>  	spin_unlock(&nm_i->nid_list_lock);
>  	radix_tree_preload_end();
> @@ -1869,7 +1882,7 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
>  	spin_lock(&nm_i->nid_list_lock);
>  	i = __lookup_free_nid_list(nm_i, nid);
>  	if (i && i->state == FREE_NID) {
> -		__remove_free_nid(sbi, i, FREE_NID, false);
> +		__remove_free_nid(sbi, i, FREE_NID);
>  		need_free = true;
>  	}
>  	spin_unlock(&nm_i->nid_list_lock);
> @@ -2080,9 +2093,7 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
>  					struct free_nid, list);
>  		*nid = i->nid;
>  
> -		__remove_free_nid(sbi, i, FREE_NID, true);
> -		i->state = PREALLOC_NID;
> -		__insert_free_nid(sbi, i, PREALLOC_NID, false);
> +		__move_free_nid(sbi, i, FREE_NID, PREALLOC_NID);
>  		nm_i->available_nids--;
>  
>  		update_free_nid_bitmap(sbi, *nid, false, false);
> @@ -2108,7 +2119,7 @@ void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
>  	spin_lock(&nm_i->nid_list_lock);
>  	i = __lookup_free_nid_list(nm_i, nid);
>  	f2fs_bug_on(sbi, !i);
> -	__remove_free_nid(sbi, i, PREALLOC_NID, false);
> +	__remove_free_nid(sbi, i, PREALLOC_NID);
>  	spin_unlock(&nm_i->nid_list_lock);
>  
>  	kmem_cache_free(free_nid_slab, i);
> @@ -2131,12 +2142,10 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
>  	f2fs_bug_on(sbi, !i);
>  
>  	if (!available_free_memory(sbi, FREE_NIDS)) {
> -		__remove_free_nid(sbi, i, PREALLOC_NID, false);
> +		__remove_free_nid(sbi, i, PREALLOC_NID);
>  		need_free = true;
>  	} else {
> -		__remove_free_nid(sbi, i, PREALLOC_NID, true);
> -		i->state = FREE_NID;
> -		__insert_free_nid(sbi, i, FREE_NID, false);
> +		__move_free_nid(sbi, i, PREALLOC_NID, FREE_NID);
>  	}
>  
>  	nm_i->available_nids++;
> @@ -2167,7 +2176,7 @@ int try_to_free_nids(struct f2fs_sb_info *sbi, int nr_shrink)
>  				nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS)
>  			break;
>  
> -		__remove_free_nid(sbi, i, FREE_NID, false);
> +		__remove_free_nid(sbi, i, FREE_NID);
>  		kmem_cache_free(free_nid_slab, i);
>  		nr_shrink--;
>  	}
> @@ -2746,7 +2755,7 @@ void destroy_node_manager(struct f2fs_sb_info *sbi)
>  	/* destroy free nid list */
>  	spin_lock(&nm_i->nid_list_lock);
>  	list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
> -		__remove_free_nid(sbi, i, FREE_NID, false);
> +		__remove_free_nid(sbi, i, FREE_NID);
>  		spin_unlock(&nm_i->nid_list_lock);
>  		kmem_cache_free(free_nid_slab, i);
>  		spin_lock(&nm_i->nid_list_lock);
>