[External] [PATCH v2] erofs: protect s_inodes with s_inode_list_lock

[Jia Zhu]

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 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 at bytedance.com>