linux-kernel - Re: [PATCH] f2fs: fix ref of discard command

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <54b5aaad-1674-8d76-c489-d5eee6ef7f26@huawei.com>
Date:   Mon, 12 Jun 2017 19:17:38 +0800
From:   Chao Yu <yuchao0@...wei.com>
To:     Jaegeuk Kim <jaegeuk@...nel.org>, <linux-kernel@...r.kernel.org>,
        <linux-fsdevel@...r.kernel.org>,
        <linux-f2fs-devel@...ts.sourceforge.net>
Subject: Re: [PATCH] f2fs: fix ref of discard command

Hi Jaegeuk,

On 2017/6/12 11:04, Jaegeuk Kim wrote:
> This patch resolves kernel panic for xfstests/081, caused by recent f2fs_bug_on
> 
>   f2fs: add f2fs_bug_on in __remove_discard_cmd
> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@...nel.org>
> ---
>  fs/f2fs/segment.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 86a0c1095939..a6d77388a806 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -1025,6 +1025,8 @@ static void __wait_discard_cmd(struct f2fs_sb_info *sbi, bool wait_cond)
>  	list_for_each_entry_safe(dc, tmp, wait_list, list) {
>  		if (!wait_cond || (dc->state == D_DONE && !dc->ref)) {
>  			wait_for_completion_io(&dc->wait);
> +			if (dc->state == D_DONE && dc->ref)
> +				dc->ref--;

Should set dc->ref to 0 to avoid panic once we add other referrers?

Thanks,

>  			__remove_discard_cmd(sbi, dc);
>  		} else {
>  			dc->ref++;
>