NVDIMM Device and Persistent Memory development
 help / color / mirror / Atom feed
From: Dan Williams <dan.j.williams@intel.com>
To: gregkh@linuxfoundation.org
Cc: Vishal Verma <vishal.l.verma@intel.com>,
	Ira Weiny <ira.weiny@intel.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org,
	nvdimm@lists.linux.dev
Subject: [PATCH] driver core: Add a guard() definition for the device_lock()
Date: Wed, 13 Dec 2023 15:02:35 -0800	[thread overview]
Message-ID: <170250854466.1522182.17555361077409628655.stgit@dwillia2-xfh.jf.intel.com> (raw)

At present there are ~200 usages of device_lock() in the kernel. Some of
those usages lead to "goto unlock;" patterns which have proven to be
error prone. Define a "device" guard() definition to allow for those to
be cleaned up and prevent new ones from appearing.

Link: http://lore.kernel.org/r/657897453dda8_269bd29492@dwillia2-mobl3.amr.corp.intel.com.notmuch
Link: http://lore.kernel.org/r/6577b0c2a02df_a04c5294bb@dwillia2-xfh.jf.intel.com.notmuch
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
Hi Greg,

I wonder if you might include this change in v6.7-rc to ease some patch
sets alternately going through my tree and Andrew's tree. Those
discussions are linked above. Alternately I can can just take it through
my tree with your ack and the other use case can circle back to it in
the v6.9 cycle.

I considered also defining a __free() helper similar to __free(mutex),
but I think "__free(device)" would be a surprising name for something
that drops a lock. Also, I like the syntax of guard(device) over
something like guard(device_lock) since a 'struct device *' is the
argument, not a lock type, but I'm open to your or Peter's thoughts on
the naming.

 include/linux/device.h |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/device.h b/include/linux/device.h
index d7a72a8749ea..6c83294395ac 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1007,6 +1007,8 @@ static inline void device_unlock(struct device *dev)
 	mutex_unlock(&dev->mutex);
 }
 
+DEFINE_GUARD(device, struct device *, device_lock(_T), device_unlock(_T))
+
 static inline void device_lock_assert(struct device *dev)
 {
 	lockdep_assert_held(&dev->mutex);


             reply	other threads:[~2023-12-13 23:02 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-12-13 23:02 Dan Williams [this message]
2023-12-13 23:47 ` [PATCH] driver core: Add a guard() definition for the device_lock() Ira Weiny
2023-12-14  0:01 ` Verma, Vishal L
2023-12-14 15:33 ` Greg KH
2023-12-14 15:49 ` Dave Jiang

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=170250854466.1522182.17555361077409628655.stgit@dwillia2-xfh.jf.intel.com \
    --to=dan.j.williams@intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=ira.weiny@intel.com \
    --cc=linux-cxl@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nvdimm@lists.linux.dev \
    --cc=peterz@infradead.org \
    --cc=vishal.l.verma@intel.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 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 read-only IMAP folder(s) and NNTP newsgroup(s).