linux-kernel - Re: [PATCH v2] erofs: simplify the code using for_each_set

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Message-ID: <d4a41ddd-726c-4dee-a563-12b2b83d071c@linux.alibaba.com>
Date: Thu, 18 Dec 2025 11:02:52 +0800
From: Gao Xiang <hsiangkao@...ux.alibaba.com>
To: Yuwen Chen <ywen.chen@...mail.com>, xiang@...nel.org
Cc: chao@...nel.org, huyue2@...lpad.com, jefflexu@...ux.alibaba.com,
 linux-erofs@...ts.ozlabs.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] erofs: simplify the code using for_each_set_bit



On 2025/12/18 10:57, Yuwen Chen wrote:
> When mounting the EROFS file system, it is necessary to check the
> available compression algorithms. At this time, the for_each_set_bit
> function can be used to simplify the code logic.
> 
> Signed-off-by: Yuwen Chen <ywen.chen@...mail.com>
> ---
> 
> v1 -> v2:
>      - revert the modifications to the fs/erofs/internal.h
> 
>   fs/erofs/decompressor.c | 11 ++++-------
>   1 file changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
> index 2ec9b2bb628d6..be1e19b620523 100644
> --- a/fs/erofs/decompressor.c
> +++ b/fs/erofs/decompressor.c
> @@ -405,7 +405,7 @@ int z_erofs_parse_cfgs(struct super_block *sb, struct erofs_super_block *dsb)
>   {
>   	struct erofs_sb_info *sbi = EROFS_SB(sb);
>   	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
> -	unsigned int algs, alg;
> +	unsigned long algs, alg;
>   	erofs_off_t offset;
>   	int size, ret = 0;
>   
> @@ -423,13 +423,10 @@ int z_erofs_parse_cfgs(struct super_block *sb, struct erofs_super_block *dsb)
>   
>   	erofs_init_metabuf(&buf, sb);
>   	offset = EROFS_SUPER_OFFSET + sbi->sb_size;
> -	alg = 0;
> -	for (algs = sbi->available_compr_algs; algs; algs >>= 1, ++alg) {
> +	algs = sbi->available_compr_algs;

Can you update as what I suggested?

Assign `algs` first, and then assign sbi->available_compr_algs.

Thanks,
Gao Xiang