linux-ext4 - Re: [PATCH 4/5] ext2: code cleanup for ext2_try_to

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Date:   Wed, 6 Nov 2019 16:59:00 +0100
From:   Jan Kara <jack@...e.cz>
To:     Chengguang Xu <cgxu519@...ernel.net>
Cc:     jack@...e.com, linux-ext4@...r.kernel.org
Subject: Re: [PATCH 4/5] ext2: code cleanup for ext2_try_to_allocate()

On Mon 04-11-19 19:40:35, Chengguang Xu wrote:
> Code cleanup by removing duplicated code.
> 
> Signed-off-by: Chengguang Xu <cgxu519@...ernel.net>

Thanks for the patch! I've merged it with a small update to switch the
while() loop into a for() loop which is somewhat more natural in that
situation. Resulting patch attached.

								Honza

> ---
>  fs/ext2/balloc.c | 32 ++++++++++++++------------------
>  1 file changed, 14 insertions(+), 18 deletions(-)
> 
> diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
> index a0c22e166682..9a9bd566243d 100644
> --- a/fs/ext2/balloc.c
> +++ b/fs/ext2/balloc.c
> @@ -710,29 +710,25 @@ ext2_try_to_allocate(struct super_block *sb, int group,
>  				;
>  		}
>  	}
> -	start = grp_goal;
>  
> -repeat:
> -	if (ext2_set_bit_atomic(sb_bgl_lock(EXT2_SB(sb), group), grp_goal,
> -			       				bitmap_bh->b_data)) {
> -		/*
> -		 * The block was allocated by another thread, or it was
> -		 * allocated and then freed by another thread
> -		 */
> -		start++;
> -		grp_goal++;
> -		if (start >= end)
> -			goto fail_access;
> -		goto repeat;
> -	}
> -	num++;
> -	grp_goal++;
> -	while (num < *count && grp_goal < end
> -		&& !ext2_set_bit_atomic(sb_bgl_lock(EXT2_SB(sb), group),
> +	while (num < *count && grp_goal < end) {
> +		if (ext2_set_bit_atomic(sb_bgl_lock(EXT2_SB(sb), group),
>  					grp_goal, bitmap_bh->b_data)) {
> +			if (num == 0) {
> +				grp_goal++;
> +				continue;
> +			} else {
> +				break;
> +			}
> +		}
> +
>  		num++;
>  		grp_goal++;
>  	}
> +
> +	if (!num)
> +		goto fail_access;
> +
>  	*count = num;
>  	return grp_goal - num;
>  fail_access:
> -- 
> 2.20.1
> 
> 
> 
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR

View attachment "0001-ext2-code-cleanup-for-ext2_try_to_allocate.patch" of type "text/x-patch" (1574 bytes)