From: Dan Carpenter <dan.carpenter@oracle.com>
To: Wenchao Hao <haowenchao@huawei.com>
Cc: fmdefrancesco@gmail.com, axboe@kernel.dk, jejb@linux.ibm.com,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-scsi@vger.kernel.org, martin.petersen@oracle.com,
syzbot+f08c77040fa163a75a46@syzkaller.appspotmail.com,
syzkaller-bugs@googlegroups.com, linfeilong@huawei.com
Subject: Re: [PATCH] scsi: sd: call device_del() if device_add_disk() fails
Date: Thu, 31 Mar 2022 08:41:56 +0300 [thread overview]
Message-ID: <20220331054156.GI3293@kadam> (raw)
In-Reply-To: <20220331152622.616534-1-haowenchao@huawei.com>
On Thu, Mar 31, 2022 at 11:26:22AM -0400, 'Wenchao Hao' via syzkaller-bugs wrote:
> I do not think it's necessary to call device_del() on this path. If the device
> has been added, put_device() would delete it from sysfs. So the origin error
> handle is ok with me.
>
No. The original is buggy and it was detected at runtime by syzbot.
It's not static analysis, it is an actual bug found in testing.
The device_put() unwinds device_initialize(). The device_del() unwinds
device_add(). Take a look at the comments to device_add() or take a
look at how device_register/unregister() work.
The temptation was to call device_unregister() which is a combined
device_del(); device_put(); but when the device_initialize() and
device_add() are called separately, then I think it is more readable to
call del and put separately as well.
regards,
dan carpenter
next prev parent reply other threads:[~2022-03-31 5:42 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-29 15:49 [PATCH] scsi: sd: call device_del() if device_add_disk() fails Fabio M. De Francesco
2022-03-30 4:30 ` Dan Carpenter
2022-03-31 15:26 ` Wenchao Hao
2022-03-31 5:41 ` Dan Carpenter [this message]
2022-03-31 5:45 ` Christoph Hellwig
2022-03-31 9:07 ` Fabio M. De Francesco
2022-03-31 9:13 ` Christoph Hellwig
2022-03-31 10:13 ` Fabio M. De Francesco
2022-03-31 12:14 ` Wenchao Hao
2022-03-31 13:42 ` Dan Carpenter
2022-03-31 14:19 ` James Bottomley
2022-03-31 15:11 ` Dan Carpenter
2022-03-31 16:14 ` Fabio M. De Francesco
2022-03-31 16:24 ` Dan Carpenter
2022-03-31 17:21 ` Fabio M. De Francesco
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=20220331054156.GI3293@kadam \
--to=dan.carpenter@oracle.com \
--cc=axboe@kernel.dk \
--cc=fmdefrancesco@gmail.com \
--cc=haowenchao@huawei.com \
--cc=jejb@linux.ibm.com \
--cc=linfeilong@huawei.com \
--cc=linux-block@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=martin.petersen@oracle.com \
--cc=syzbot+f08c77040fa163a75a46@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.