linux-kernel - Re: [PATCH 1/2] exfat: fix referencing wrong parent directory information after renaming

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Date:   Mon, 28 Mar 2022 10:43:39 +0900
From:   Namjae Jeon <linkinjeon@...nel.org>
To:     "Yuezhang.Mo@...y.com" <Yuezhang.Mo@...y.com>
Cc:     "sj1557.seo@...sung.com" <sj1557.seo@...sung.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
        "Andy.Wu@...y.com" <Andy.Wu@...y.com>,
        "Wataru.Aoyama@...y.com" <Wataru.Aoyama@...y.com>,
        "Kohada.Tetsuhiro@...MitsubishiElectric.co.jp" 
        <Kohada.Tetsuhiro@...mitsubishielectric.co.jp>
Subject: Re: [PATCH 1/2] exfat: fix referencing wrong parent directory
 information after renaming

2022-03-25 18:42 GMT+09:00, Yuezhang.Mo@...y.com <Yuezhang.Mo@...y.com>:
Hi Yuezhang,

> During renaming, the parent directory information maybe
> updated. But the file/directory still references to the
> old parent directory information.
>
> This bug will cause 2 problems.
>
> (1) The renamed file can not be written.
>
>     [10768.175172] exFAT-fs (sda1): error, failed to bmap (inode : 7afd50e4
> iblock : 0, err : -5)
>     [10768.184285] exFAT-fs (sda1): Filesystem has been set read-only
>     ash: write error: Input/output error
Could you please elaborate how to reproduce it ?

Thanks.
>
> (2) Some dentries of the renamed file/directory are not set
>     to deleted after removing the file/directory.
>
> fixes: 5f2aa075070c ("exfat: add inode operations")
>
> Signed-off-by: Yuezhang Mo <Yuezhang.Mo@...y.com>
> Reviewed-by: Andy Wu <Andy.Wu@...y.com>
> Reviewed-by: Aoyama Wataru <wataru.aoyama@...y.com>
> Reviewed-by: Daniel Palmer <daniel.palmer@...y.com>
> ---
>  fs/exfat/namei.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
> index a02a04a993bf..e7adb6bfd9d5 100644
> --- a/fs/exfat/namei.c
> +++ b/fs/exfat/namei.c
> @@ -1080,6 +1080,7 @@ static int exfat_rename_file(struct inode *inode,
> struct exfat_chain *p_dir,
>
>  		exfat_remove_entries(inode, p_dir, oldentry, 0,
>  			num_old_entries);
> +		ei->dir = *p_dir;
>  		ei->entry = newentry;
>  	} else {
>  		if (exfat_get_entry_type(epold) == TYPE_FILE) {
> --
> 2.25.1
>