Re: [PATCH v3 07/13] btrfs: pass space_info for block group creation

[Josef Bacik <josef@toxicpanda.com>]

On Wed, Apr 16, 2025 at 11:28:12PM +0900, Naohiro Aota wrote:
> Add btrfs_space_info parameter to btrfs_make_block_group(), its related
> functions and related struct. Passed space_info will have a new block
> group. If NULL is passed, it uses the default space_info.
> 
> The parameter is used in a later commit and the behavior is unchanged now.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> ---
>  fs/btrfs/block-group.c | 18 ++++++++++--------
>  fs/btrfs/block-group.h |  4 ++--
>  fs/btrfs/volumes.c     | 22 +++++++++++++++++-----
>  fs/btrfs/volumes.h     |  3 ++-
>  4 files changed, 31 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
> index 12cc9069d4bb..846c9737ff5a 100644
> --- a/fs/btrfs/block-group.c
> +++ b/fs/btrfs/block-group.c
> @@ -2866,8 +2866,8 @@ static u64 calculate_global_root_id(const struct btrfs_fs_info *fs_info, u64 off
>  }
>  
>  struct btrfs_block_group *btrfs_make_block_group(struct btrfs_trans_handle *trans,
> -						 u64 type,
> -						 u64 chunk_offset, u64 size)
> +						 struct btrfs_space_info *space_info,
> +						 u64 type, u64 chunk_offset, u64 size)
>  {
>  	struct btrfs_fs_info *fs_info = trans->fs_info;
>  	struct btrfs_block_group *cache;
> @@ -2921,7 +2921,7 @@ struct btrfs_block_group *btrfs_make_block_group(struct btrfs_trans_handle *tran
>  	 * assigned to our block group. We want our bg to be added to the rbtree
>  	 * with its ->space_info set.
>  	 */
> -	cache->space_info = btrfs_find_space_info(fs_info, cache->flags);
> +	cache->space_info = space_info;
>  	ASSERT(cache->space_info);
>  
>  	ret = btrfs_add_block_group_cache(cache);
> @@ -3902,7 +3902,9 @@ int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type)
>  	return btrfs_chunk_alloc(trans, NULL, alloc_flags, CHUNK_ALLOC_FORCE);
>  }
>  
> -static struct btrfs_block_group *do_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags)
> +static struct btrfs_block_group *do_chunk_alloc(struct btrfs_trans_handle *trans,
> +						struct btrfs_space_info *space_info,
> +						u64 flags)
>  {
>  	struct btrfs_block_group *bg;
>  	int ret;
> @@ -3915,7 +3917,7 @@ static struct btrfs_block_group *do_chunk_alloc(struct btrfs_trans_handle *trans
>  	 */
>  	check_system_chunk(trans, flags);
>  
> -	bg = btrfs_create_chunk(trans, flags);
> +	bg = btrfs_create_chunk(trans, space_info, flags);
>  	if (IS_ERR(bg)) {
>  		ret = PTR_ERR(bg);
>  		goto out;
> @@ -3964,7 +3966,7 @@ static struct btrfs_block_group *do_chunk_alloc(struct btrfs_trans_handle *trans
>  		const u64 sys_flags = btrfs_system_alloc_profile(trans->fs_info);
>  		struct btrfs_block_group *sys_bg;
>  
> -		sys_bg = btrfs_create_chunk(trans, sys_flags);
> +		sys_bg = btrfs_create_chunk(trans, NULL, sys_flags);
>  		if (IS_ERR(sys_bg)) {
>  			ret = PTR_ERR(sys_bg);
>  			btrfs_abort_transaction(trans, ret);
> @@ -4214,7 +4216,7 @@ int btrfs_chunk_alloc(struct btrfs_trans_handle *trans,
>  			force_metadata_allocation(fs_info);
>  	}
>  
> -	ret_bg = do_chunk_alloc(trans, flags);
> +	ret_bg = do_chunk_alloc(trans, space_info, flags);
>  	trans->allocating_chunk = false;
>  
>  	if (IS_ERR(ret_bg)) {
> @@ -4297,7 +4299,7 @@ static void reserve_chunk_space(struct btrfs_trans_handle *trans,
>  		 * the paths we visit in the chunk tree (they were already COWed
>  		 * or created in the current transaction for example).
>  		 */
> -		bg = btrfs_create_chunk(trans, flags);
> +		bg = btrfs_create_chunk(trans, NULL, flags);
>  		if (IS_ERR(bg)) {
>  			ret = PTR_ERR(bg);
>  		} else {
> diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
> index c01f3af726a1..35309b690d6f 100644
> --- a/fs/btrfs/block-group.h
> +++ b/fs/btrfs/block-group.h
> @@ -326,8 +326,8 @@ void btrfs_reclaim_bgs(struct btrfs_fs_info *fs_info);
>  void btrfs_mark_bg_to_reclaim(struct btrfs_block_group *bg);
>  int btrfs_read_block_groups(struct btrfs_fs_info *info);
>  struct btrfs_block_group *btrfs_make_block_group(struct btrfs_trans_handle *trans,
> -						 u64 type,
> -						 u64 chunk_offset, u64 size);
> +						 struct btrfs_space_info *space_info,
> +						 u64 type, u64 chunk_offset, u64 size);
>  void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
>  int btrfs_inc_block_group_ro(struct btrfs_block_group *cache,
>  			     bool do_chunk_alloc);
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 7509cbe3272c..5462c832ea19 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -3420,7 +3420,7 @@ int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset)
>  		const u64 sys_flags = btrfs_system_alloc_profile(fs_info);
>  		struct btrfs_block_group *sys_bg;
>  
> -		sys_bg = btrfs_create_chunk(trans, sys_flags);
> +		sys_bg = btrfs_create_chunk(trans, NULL, sys_flags);
>  		if (IS_ERR(sys_bg)) {
>  			ret = PTR_ERR(sys_bg);
>  			btrfs_abort_transaction(trans, ret);
> @@ -5216,6 +5216,8 @@ struct alloc_chunk_ctl {
>  	u64 stripe_size;
>  	u64 chunk_size;
>  	int ndevs;
> +	/* Space_info the block group is going to belong. */
> +	struct btrfs_space_info *space_info;
>  };
>  
>  static void init_alloc_chunk_ctl_policy_regular(
> @@ -5617,7 +5619,8 @@ static struct btrfs_block_group *create_chunk(struct btrfs_trans_handle *trans,
>  		return ERR_PTR(ret);
>  	}
>  
> -	block_group = btrfs_make_block_group(trans, type, start, ctl->chunk_size);
> +	block_group = btrfs_make_block_group(trans, ctl->space_info, type, start,
> +					     ctl->chunk_size);
>  	if (IS_ERR(block_group)) {
>  		btrfs_remove_chunk_map(info, map);
>  		return block_group;
> @@ -5643,7 +5646,8 @@ static struct btrfs_block_group *create_chunk(struct btrfs_trans_handle *trans,
>  }
>  
>  struct btrfs_block_group *btrfs_create_chunk(struct btrfs_trans_handle *trans,
> -					    u64 type)
> +					     struct btrfs_space_info *space_info,
> +					     u64 type)
>  {
>  	struct btrfs_fs_info *info = trans->fs_info;
>  	struct btrfs_fs_devices *fs_devices = info->fs_devices;
> @@ -5671,8 +5675,16 @@ struct btrfs_block_group *btrfs_create_chunk(struct btrfs_trans_handle *trans,
>  		return ERR_PTR(-EINVAL);
>  	}
>  
> +	if (!space_info) {
> +		space_info = btrfs_find_space_info(info, type);
> +		if (!space_info) {
> +			ASSERT(0);
> +			return ERR_PTR(-EINVAL);
> +		}
> +	}

Same comment here, make everybody send down the space_info instead of it being
optional.  Thanks,

Josef