From: Tejun Heo <tj@kernel.org>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
"Theodore Ts'o" <tytso@mit.edu>,
Kernel development list <linux-kernel@vger.kernel.org>,
Greg Kroah-Hartman <gregkh@suse.de>,
Kay Sievers <kay.sievers@vrfy.org>
Subject: Re: Revoking filesystems [was Re: Sysfs attributes racing with unregistration]
Date: Thu, 5 Jan 2012 09:11:57 -0800 [thread overview]
Message-ID: <20120105171157.GA18486@google.com> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1201051133490.1434-100000@iolanthe.rowland.org>
Hello,
On Thu, Jan 05, 2012 at 11:47:54AM -0500, Alan Stern wrote:
> One problem (which was reported by a user last spring) is that
> del_gendisk() calls device_del() for the disk and bdi_unregister() for
> the disk's backing_dev_info structure. Now, del_gendisk will leave the
> data structure in memory until the disk's refcount drops to 0, but
> bdi_unregister ignores refcounts and simply erases the bdi->dev
> pointer. Once this happens, any attempt to call mark_buffer_dirty()
> (for example, by ext4_commit_super) will cause an oops.
Yeah, there were multiple bugs in block device hot-removal path. I
got some of them fixed recently but didn't get to the bdi one yet.
It's a bug and needs to be fixed regardless of fs revoke support.
Thanks.
--
tejun
next prev parent reply other threads:[~2012-01-05 17:12 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-04 16:52 Sysfs attributes racing with unregistration Alan Stern
2012-01-04 17:18 ` Tejun Heo
2012-01-04 18:13 ` Eric W. Biederman
2012-01-04 19:41 ` Alan Stern
2012-01-05 3:07 ` Eric W. Biederman
2012-01-05 15:13 ` Revoking filesystems [was Re: Sysfs attributes racing with unregistration] Alan Stern
2012-01-05 15:32 ` Tejun Heo
2012-01-05 16:03 ` Eric W. Biederman
2012-01-05 16:44 ` Tejun Heo
2012-01-05 16:47 ` Alan Stern
2012-01-05 17:11 ` Tejun Heo [this message]
2012-01-05 18:27 ` Ted Ts'o
2012-01-05 18:36 ` Tejun Heo
2012-01-05 19:28 ` Ted Ts'o
2012-01-05 20:52 ` Tejun Heo
2012-01-06 6:25 ` Alexander E. Patrakov
2012-01-07 21:01 ` Revoking filesystems [was Re: Sysfs attributes racing withunregistration] Milton Miller
2012-01-05 20:43 ` Revoking filesystems [was Re: Sysfs attributes racing with unregistration] Eric W. Biederman
2012-01-05 20:55 ` Tejun Heo
2012-01-05 18:38 ` Christoph Hellwig
2012-01-05 15:52 ` Eric W. Biederman
2013-01-14 15:11 ` watchdog code anish kumar
2012-01-05 18:18 ` Revoking filesystems [was Re: Sysfs attributes racing with unregistration] Greg KH
2012-01-04 18:13 ` Sysfs attributes racing with unregistration Alan Stern
2012-01-04 18:20 ` Tejun Heo
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=20120105171157.GA18486@google.com \
--to=tj@kernel.org \
--cc=ebiederm@xmission.com \
--cc=gregkh@suse.de \
--cc=kay.sievers@vrfy.org \
--cc=linux-kernel@vger.kernel.org \
--cc=stern@rowland.harvard.edu \
--cc=tytso@mit.edu \
/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.