linux-ext4 - Re: [PATCH v3 08/19] ext4: get block from bh before pass it to ext4_free_blocks_simple in ext4_free

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Date:   Fri, 12 May 2023 11:59:10 +0530
From:   Ojaswin Mujoo <ojaswin@...ux.ibm.com>
To:     Kemeng Shi <shikemeng@...weicloud.com>
Cc:     tytso@....edu, adilger.kernel@...ger.ca,
        linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 08/19] ext4: get block from bh before pass it to
 ext4_free_blocks_simple in ext4_free_blocks

On Mon, Apr 17, 2023 at 07:06:06PM +0800, Kemeng Shi wrote:
> ext4_free_blocks will retrieve block from bh if block parameter is zero.
> Retrieve block before ext4_free_blocks_simple to avoid potentially
> passing wrong block to ext4_free_blocks_simple.
> 
> Signed-off-by: Kemeng Shi <shikemeng@...weicloud.com>
Hi Kemeng,

Nice catch! feel free to add:

Reviewed-by: Ojaswin Mujoo <ojaswin@...ux.ibm.com>
> ---
>  fs/ext4/mballoc.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index e980513c7a14..f37e921c11e5 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -6310,12 +6310,6 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
>  
>  	sbi = EXT4_SB(sb);
>  
> -	if (sbi->s_mount_state & EXT4_FC_REPLAY) {
> -		ext4_free_blocks_simple(inode, block, count);
> -		return;
> -	}
> -
> -	might_sleep();
>  	if (bh) {
>  		if (block)
>  			BUG_ON(block != bh->b_blocknr);
> @@ -6323,6 +6317,13 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
>  			block = bh->b_blocknr;
>  	}
>  
> +	if (sbi->s_mount_state & EXT4_FC_REPLAY) {
> +		ext4_free_blocks_simple(inode, block, count);
> +		return;
> +	}
> +
> +	might_sleep();
> +
>  	if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
>  	    !ext4_inode_block_valid(inode, block, count)) {
>  		ext4_error(sb, "Freeing blocks not in datazone - "
> -- 
> 2.30.0
>