From: jiangyiwen <jiangyiwen@huawei•com>
To: "cgxu519@gmx•com" <cgxu519@gmx•com>
Cc: <ericvh@gmail•com>, <rminnich@sandia•gov>, <lucho@ionkov•net>,
<davem@davemloft•net>, <v9fs-developer@lists•sourceforge.net>,
<netdev@vger•kernel.org>
Subject: Re: [V9fs-developer] [PATCH] net/9p: fix potential refcnt problem of trans module
Date: Wed, 28 Mar 2018 11:38:40 +0800 [thread overview]
Message-ID: <5ABB0E40.9000002@huawei.com> (raw)
In-Reply-To: <FFF9EE2E-713C-48C8-AA8D-9C54BEC2249A@gmx.com>
On 2018/3/28 10:52, cgxu519@gmx•com wrote:
> 在 2018年3月28日，上午10:10，jiangyiwen <jiangyiwen@huawei•com> 写道：
>>
>> On 2018/3/27 20:49, Chengguang Xu wrote:
>>> When specifying trans_mod multiple times in a mount,
>>> it may cause inaccurate refcount of trans module. Also,
>>> in the error case of option parsing, we should put the
>>> trans module if we have already got.
>>>
>>> Signed-off-by: Chengguang Xu <cgxu519@gmx•com>
>>> ---
>>> net/9p/client.c | 5 ++++-
>>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/net/9p/client.c b/net/9p/client.c
>>> index b433aff..7ccfb4b 100644
>>> --- a/net/9p/client.c
>>> +++ b/net/9p/client.c
>>> @@ -190,7 +190,9 @@ static int parse_opts(char *opts, struct p9_client *clnt)
>>> p9_debug(P9_DEBUG_ERROR,
>>> "problem allocating copy of trans arg\n");
>>> goto free_and_return;
>>> - }
>>> + }
>>> +
>>> + v9fs_put_trans(clnt->trans_mod);
>>
>> I think this should return error if using multiple times
>> in a mount.
>
> Fail or retake are just different policies how to deal with this kind of situation,
> most filesystems in kernel choose retaking new value, so we’d better keep consistence
> with others unless there is a necessary reason.
>
> Thanks,
> Chengguang.
>
Yes, you're right, most filesystems retake indeed the new value.
Reviewed-by: Yiwen Jiang <jiangyiwen@huawei•com>
>
>>
>>> clnt->trans_mod = v9fs_get_trans_by_name(s);
>>> if (clnt->trans_mod == NULL) {
>>> pr_info("Could not find request transport: %s\n",
>>> @@ -226,6 +228,7 @@ static int parse_opts(char *opts, struct p9_client *clnt)
>>> }
>>>
>>> free_and_return:
>>> + v9fs_put_trans(clnt->trans_mod);
>>
>> This looks good.
>>
>>> kfree(tmp_options);
>>> return ret;
>>> }
>>>
>>
>>
>
>
> .
>
prev parent reply other threads:[~2018-03-28 3:38 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-27 12:49 [PATCH] net/9p: fix potential refcnt problem of trans module Chengguang Xu
2018-03-28 2:10 ` [V9fs-developer] " jiangyiwen
2018-03-28 2:52 ` cgxu519
2018-03-28 3:38 ` jiangyiwen [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5ABB0E40.9000002@huawei.com \
--to=jiangyiwen@huawei$(echo .)com \
--cc=cgxu519@gmx$(echo .)com \
--cc=davem@davemloft$(echo .)net \
--cc=ericvh@gmail$(echo .)com \
--cc=lucho@ionkov$(echo .)net \
--cc=netdev@vger$(echo .)kernel.org \
--cc=rminnich@sandia$(echo .)gov \
--cc=v9fs-developer@lists$(echo .)sourceforge.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox