linux-kernel - Re: [PATCH v6 02/11] ext4: call ext4_mb_mark_context in ext4_free_blocks

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Message-Id: <87jztb8f1k.fsf@doe.com>
Date:   Thu, 31 Aug 2023 19:55:27 +0530
From:   Ritesh Harjani (IBM) <ritesh.list@...il.com>
To:     Kemeng Shi <shikemeng@...weicloud.com>, tytso@....edu,
        adilger.kernel@...ger.ca, linux-ext4@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v6 02/11] ext4: call ext4_mb_mark_context in ext4_free_blocks_simple

Kemeng Shi <shikemeng@...weicloud.com> writes:

> call ext4_mb_mark_context in ext4_free_blocks_simple to:
> 1. remove repeat code
> 2. pair update of free_clusters in ext4_mb_new_blocks_simple.
> 3. add missing ext4_lock_group/ext4_unlock_group protection.
>
> Signed-off-by: Kemeng Shi <shikemeng@...weicloud.com>
> ---
>  fs/ext4/mballoc.c | 35 +++--------------------------------
>  1 file changed, 3 insertions(+), 32 deletions(-)

Looks good to me. Please feel free to add - 

Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@...il.com>

(One small comment below for previous patch)

>
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index e2be572deb75..c803f74aaf63 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -6414,43 +6414,14 @@ ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
>  static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block,
>  					unsigned long count)
>  {
> -	struct buffer_head *bitmap_bh;
> +	struct ext4_mark_context mc;
>  	struct super_block *sb = inode->i_sb;
> -	struct ext4_group_desc *gdp;
> -	struct buffer_head *gdp_bh;
>  	ext4_group_t group;
>  	ext4_grpblk_t blkoff;
> -	int already_freed = 0, err, i;
>  
> +	ext4_mb_prepare_mark_context(&mc, sb, 0);

It looks like we always use 0 or 1 as the state for struct
ext4_mark_context. In that case we can keep state member of this struct
as bool instead of int. 


>  	ext4_get_group_no_and_offset(sb, block, &group, &blkoff);
> -	bitmap_bh = ext4_read_block_bitmap(sb, group);
> -	if (IS_ERR(bitmap_bh)) {
> -		pr_warn("Failed to read block bitmap\n");
> -		return;
> -	}
> -	gdp = ext4_get_group_desc(sb, group, &gdp_bh);
> -	if (!gdp)
> -		goto err_out;
> -
> -	for (i = 0; i < count; i++) {
> -		if (!mb_test_bit(blkoff + i, bitmap_bh->b_data))
> -			already_freed++;
> -	}
> -	mb_clear_bits(bitmap_bh->b_data, blkoff, count);
> -	err = ext4_handle_dirty_metadata(NULL, NULL, bitmap_bh);
> -	if (err)
> -		goto err_out;
> -	ext4_free_group_clusters_set(
> -		sb, gdp, ext4_free_group_clusters(sb, gdp) +
> -		count - already_freed);
> -	ext4_block_bitmap_csum_set(sb, gdp, bitmap_bh);
> -	ext4_group_desc_csum_set(sb, group, gdp);
> -	ext4_handle_dirty_metadata(NULL, NULL, gdp_bh);
> -	sync_dirty_buffer(bitmap_bh);
> -	sync_dirty_buffer(gdp_bh);
> -
> -err_out:
> -	brelse(bitmap_bh);
> +	ext4_mb_mark_context(&mc, group, blkoff, count);
>  }
>  
>  /**
> -- 
> 2.30.0