linux-kernel - Re: [PATCH v2 1/2] f2fs: Add a method for calculating the remaining blocks in the current segment in LFS mode.

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Message-ID: <1db80259-a29d-439e-aaff-2a7daac9c1e5@kernel.org>
Date: Tue, 6 May 2025 17:09:26 +0800
From: Chao Yu <chao@...nel.org>
To: "yohan.joung" <yohan.joung@...com>, jaegeuk@...nel.org,
 daehojeong@...gle.com
Cc: chao@...nel.org, linux-kernel@...r.kernel.org,
 linux-f2fs-devel@...ts.sourceforge.net, pilhyun.kim@...com
Subject: Re: [PATCH v2 1/2] f2fs: Add a method for calculating the remaining
 blocks in the current segment in LFS mode.

On 2025/5/2 12:41, yohan.joung wrote:
> In LFS mode, the previous segment cannot use invalid blocks,
> so the remaining blocks from the next_blkoff of the current segment
> to the end of the section are calculated.
> 
> Signed-off-by: yohan.joung <yohan.joung@...com>
> ---
>   fs/f2fs/segment.h | 21 +++++++++++++++++----
>   1 file changed, 17 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
> index 03c0f59be5a8..345da052f0e1 100644
> --- a/fs/f2fs/segment.h
> +++ b/fs/f2fs/segment.h
> @@ -582,8 +582,14 @@ static inline bool has_curseg_enough_space(struct f2fs_sb_info *sbi,
>   		if (unlikely(segno == NULL_SEGNO))
>   			return false;
>   
> -		left_blocks = CAP_BLKS_PER_SEC(sbi) -
> -				get_ckpt_valid_blocks(sbi, segno, true);
> +		if (f2fs_lfs_mode(sbi)) {

f2fs_lfs_mode() && __is_large_section(sbi)?

> +			left_blocks = CAP_BLKS_PER_SEC(sbi) -
> +				(segno - rounddown(segno, SEGS_PER_SEC(sbi))) * BLKS_PER_SEG(sbi) -

How about using SEGS_TO_BLKS() which will be more efficient? and what do you
think of introducing a new macro to improve code readability?

#define GET_START_SEG_FROM_SEC(sbi, segno)	(rounddown(segno, SEGS_PER_SEC(sbi)))

> +				CURSEG_I(sbi, i)->next_blkoff;
> +		} else {
> +			left_blocks = CAP_BLKS_PER_SEC(sbi) -
> +					get_ckpt_valid_blocks(sbi, segno, true);
> +		}
>   
>   		blocks = i <= CURSEG_COLD_DATA ? data_blocks : node_blocks;
>   		if (blocks > left_blocks)
> @@ -596,8 +602,15 @@ static inline bool has_curseg_enough_space(struct f2fs_sb_info *sbi,
>   	if (unlikely(segno == NULL_SEGNO))
>   		return false;
>   
> -	left_blocks = CAP_BLKS_PER_SEC(sbi) -
> -			get_ckpt_valid_blocks(sbi, segno, true);
> +	if (f2fs_lfs_mode(sbi)) {

Ditto,

> +		left_blocks = CAP_BLKS_PER_SEC(sbi) -
> +				(segno - rounddown(segno, SEGS_PER_SEC(sbi))) * BLKS_PER_SEG(sbi) -
> +				CURSEG_I(sbi, CURSEG_HOT_DATA)->next_blkoff;

Ditto,

Thanks,

> +	} else {
> +		left_blocks = CAP_BLKS_PER_SEC(sbi) -
> +				get_ckpt_valid_blocks(sbi, segno, true);
> +	}
> +
>   	if (dent_blocks > left_blocks)
>   		return false;
>   	return true;