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

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Message-ID: <fda8fc5b-f205-1557-4456-027ba6e02b1d@huaweicloud.com>
Date:   Mon, 4 Sep 2023 10:51:20 +0800
From:   Kemeng Shi <shikemeng@...weicloud.com>
To:     Ritesh Harjani <ritesh.list@...il.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



on 8/31/2023 10:25 PM, Ritesh Harjani wrote:
> 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. 
Get it. Thanks for pointing it out!
> 
> 
>>  	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
>