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Message-ID: <80e1f65f-e051-adbf-946f-ef2a27ff55f9@bytedance.com>
Date:   Mon, 17 Oct 2022 11:14:52 +0800
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Subject: Re: [External] [PATCH v2] erofs: protect s_inodes with
 s_inode_list_lock
To:     Dawei Li <set_pte_at@outlook.com>, xiang@kernel.org,
        chao@kernel.org
Cc:     huyue2@coolpad.com, jefflexu@linux.alibaba.com,
        linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org
References: <TYCP286MB23238380DE3B74874E8D78ABCA299@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COM>
From:   Jia Zhu <zhujia.zj@bytedance.com>
In-Reply-To: <TYCP286MB23238380DE3B74874E8D78ABCA299@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COM>
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在 2022/10/17 09:55, Dawei Li 写道:
> s_inodes is superblock-specific resource, which should be
> protected by sb's specific lock s_inode_list_lock.
> 
> v2: update the locking mechanisim to protect mutual-exclusive access
> both for s_inode_list_lock & erofs_fscache_domain_init_cookie(), as the
> reviewing comments from Jia Zhu.
> 
> v1: https://lore.kernel.org/all/TYCP286MB23237A9993E0FFCFE5C2BDBECA269@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COM/
> 
> base-commit: 8436c4a57bd147b0bd2943ab499bb8368981b9e1
> 
> Signed-off-by: Dawei Li <set_pte_at@outlook.com>
> ---
>   fs/erofs/fscache.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
> index 998cd26a1b3b..fe05bc51f9f2 100644
> --- a/fs/erofs/fscache.c
> +++ b/fs/erofs/fscache.c
> @@ -590,14 +590,17 @@ struct erofs_fscache *erofs_domain_register_cookie(struct super_block *sb,
>   	struct super_block *psb = erofs_pseudo_mnt->mnt_sb;
>   
>   	mutex_lock(&erofs_domain_cookies_lock);
> +	spin_lock(&psb->s_inode_list_lock);
>   	list_for_each_entry(inode, &psb->s_inodes, i_sb_list) {
>   		ctx = inode->i_private;
>   		if (!ctx || ctx->domain != domain || strcmp(ctx->name, name))
>   			continue;
>   		igrab(inode);
> +		spin_unlock(&psb->s_inode_list_lock);
>   		mutex_unlock(&erofs_domain_cookies_lock);
>   		return ctx;
>   	}
> +	spin_unlock(&psb->s_inode_list_lock);
>   	ctx = erofs_fscache_domain_init_cookie(sb, name, need_inode);
>   	mutex_unlock(&erofs_domain_cookies_lock);
>   	return ctx;
LGTM
Reviewed-by: Jia Zhu <zhujia.zj@bytedance.com>