From: Cornelia Huck <cornelia.huck@de.ibm.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Hugh Dickins <hugh@veritas.com>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Oliver Neukum <oneukum@suse.de>,
Maneesh Soni <maneesh@in.ibm.com>, <gregkh@suse.de>,
Richard Purdie <rpurdie@rpsys.net>,
James Bottomley <James.Bottomley@SteelEye.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Kernel development list <linux-kernel@vger.kernel.org>
Subject: Re: 2.6.21-rc suspend regression: sysfs deadlock
Date: Tue, 13 Mar 2007 19:42:04 +0100 [thread overview]
Message-ID: <20070313194204.5192ab19@gondolin.boeblingen.de.ibm.com> (raw)
In-Reply-To: <Pine.LNX.4.44L0.0703131046030.2509-100000@iolanthe.rowland.org>
On Tue, 13 Mar 2007 11:00:21 -0400 (EDT),
Alan Stern <stern@rowland.harvard.edu> wrote:
> The consensus is that we would be better off keeping Oliver's original
> patch without your silly change, and instead fixing the particular method
> call that deadlocked.
Another call that deadlocked with Oliver's patch is ungroup for s390
ccwgroup devices. It can be made to work again with a similar patch.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
drivers/s390/cio/ccwgroup.c | 35 +++++++++++++++++++++++++++++++----
1 file changed, 31 insertions(+), 4 deletions(-)
--- linux-2.6.orig/drivers/s390/cio/ccwgroup.c
+++ linux-2.6/drivers/s390/cio/ccwgroup.c
@@ -67,22 +67,49 @@ __ccwgroup_remove_symlinks(struct ccwgro
}
+struct ccwgroup_work_struct {
+ struct ccwgroup_device *gdev;
+ struct work_struct work;
+};
+
+static void ccwgroup_ungroup_work(struct work_struct *work)
+{
+ struct ccwgroup_work_struct *ungroup_work
+ = container_of(work, struct ccwgroup_work_struct, work);
+
+ __ccwgroup_remove_symlinks(ungroup_work->gdev);
+ device_unregister(&ungroup_work->gdev->dev);
+ put_device(&ungroup_work->gdev->dev);
+ kfree(ungroup_work);
+}
+
/*
* Provide an 'ungroup' attribute so the user can remove group devices no
* longer needed or accidentially created. Saves memory :)
+ * Note that we cannot unregister the device from one of its attribute
+ * methods, so we have to delay it.
*/
-static ssize_t
-ccwgroup_ungroup_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
+static ssize_t ccwgroup_ungroup_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
{
struct ccwgroup_device *gdev;
+ struct ccwgroup_work_struct *ungroup_work;
gdev = to_ccwgroupdev(dev);
if (gdev->state != CCWGROUP_OFFLINE)
return -EINVAL;
- __ccwgroup_remove_symlinks(gdev);
- device_unregister(dev);
+ ungroup_work = kmalloc(sizeof(*ungroup_work), GFP_KERNEL);
+ if (!ungroup_work)
+ return -ENOMEM;
+ ungroup_work->gdev = gdev;
+ INIT_WORK(&ungroup_work->work, ccwgroup_ungroup_work);
+ if (!get_device(&gdev->dev))
+ kfree(ungroup_work);
+ else
+ schedule_work(&ungroup_work->work);
return count;
}
next prev parent reply other threads:[~2007-03-13 18:40 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-08 13:05 refcounting drivers' data structures used in sysfs buffers Oliver Neukum
2007-03-08 16:02 ` Alan Stern
2007-03-09 0:45 ` Oliver Neukum
2007-03-09 16:32 ` Alan Stern
2007-03-09 16:44 ` Oliver Neukum
2007-03-09 17:02 ` Dmitry Torokhov
2007-03-09 17:18 ` Oliver Neukum
2007-03-09 17:34 ` Dmitry Torokhov
2007-03-09 19:32 ` Alan Stern
2007-03-09 20:05 ` Oliver Neukum
2007-03-09 20:27 ` Alan Stern
2007-03-09 20:39 ` Oliver Neukum
2007-03-09 20:08 ` Alan Stern
2007-03-09 20:48 ` Oliver Neukum
2007-03-10 19:19 ` Alan Stern
2007-03-12 8:54 ` Oliver Neukum
2007-03-12 14:57 ` Alan Stern
2007-03-12 15:23 ` Oliver Neukum
2007-03-12 15:42 ` Dmitry Torokhov
2007-03-12 15:59 ` Oliver Neukum
2007-03-12 16:21 ` Alan Stern
2007-03-12 18:25 ` Oliver Neukum
2007-03-12 19:31 ` Alan Stern
2007-03-12 19:49 ` Oliver Neukum
2007-03-12 20:03 ` Alan Stern
2007-03-12 20:15 ` Oliver Neukum
2007-03-12 20:31 ` Dmitry Torokhov
2007-03-12 20:45 ` Alan Stern
2007-03-12 21:31 ` Richard Purdie
2007-03-13 15:00 ` 2.6.21-rc suspend regression: sysfs deadlock Alan Stern
2007-03-13 18:42 ` Cornelia Huck [this message]
2007-03-13 21:20 ` Linus Torvalds
2007-03-14 16:12 ` Alan Stern
2007-03-14 18:43 ` Cornelia Huck
2007-03-14 19:23 ` Alan Stern
2007-03-15 10:27 ` Cornelia Huck
2007-03-15 12:31 ` Hugh Dickins
2007-03-15 13:02 ` Oliver Neukum
2007-03-15 13:22 ` Dmitry Torokhov
2007-03-15 13:59 ` Hugh Dickins
2007-03-15 14:27 ` Alan Stern
2007-03-15 15:32 ` Cornelia Huck
2007-03-15 16:29 ` Hugh Dickins
2007-03-15 16:51 ` Linus Torvalds
2007-03-15 19:50 ` [PATCH] sysfs and driver core: add callback helper, used by SCSI and S390 Alan Stern
2007-03-15 19:51 ` [PATCH] sysfs: reinstate exclusion between method calls and attribute unregistration Alan Stern
2007-03-13 19:00 ` 2.6.21-rc suspend regression: sysfs deadlock Hugh Dickins
2007-03-13 20:09 ` Alan Stern
2007-03-13 20:55 ` Hugh Dickins
2007-03-13 21:08 ` Dmitry Torokhov
2007-03-13 21:20 ` Alan Stern
-- strict thread matches above, loose matches on Subject: below --
2007-03-10 20:44 Alan Stern
2007-03-06 19:20 Hugh Dickins
2007-03-06 20:16 ` Oliver Neukum
2007-03-07 1:56 ` Linus Torvalds
2007-03-07 14:38 ` Oliver Neukum
2007-03-07 15:56 ` Dmitry Torokhov
2007-03-07 16:52 ` Linus Torvalds
2007-03-07 16:59 ` Oliver Neukum
2007-03-07 18:02 ` Linus Torvalds
2007-03-07 18:16 ` Oliver Neukum
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=20070313194204.5192ab19@gondolin.boeblingen.de.ibm.com \
--to=cornelia.huck@de.ibm.com \
--cc=James.Bottomley@SteelEye.com \
--cc=dmitry.torokhov@gmail.com \
--cc=gregkh@suse.de \
--cc=hugh@veritas.com \
--cc=linux-kernel@vger.kernel.org \
--cc=maneesh@in.ibm.com \
--cc=oneukum@suse.de \
--cc=rpurdie@rpsys.net \
--cc=stern@rowland.harvard.edu \
--cc=torvalds@linux-foundation.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).