From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 75C534C6F for ; Thu, 4 Apr 2024 01:34:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712194494; cv=none; b=dSe4lYgiFhf9oA/49cTBfRfaWYidrtF6zBEEzz2sLg0/nsHD/0GifXHEMv5de6JhBKS4avraMApZYMA/oyVzSMb4NvhTMjYzKrR1BT8hD1x2WxH299Ft2hcLOM/QeWK+ebaYrPYNtksifOWK+DnP/Rd0OB8uY4msxUSLqDCP3hk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712194494; c=relaxed/simple; bh=Tu7snND44euMQoi+uvf+b5FVigQnGX2HHS6AqFbUpL0=; h=Date:To:From:Subject:Message-Id; b=B+aAUwLhjM+SpL3Z2tr1EP+cUez7lhP5UevERafDCGdddyTi6YgEAokQQXqYwdmIPIUFgSGRs+4sYgibKifVsk9e8k/fFSaurenpoTyqXsYv17lzDBO4FEmICQBi5gxyLK+u9TEwtP3Ll6Hq7uVJ907Kz6XUH3ZJ0Q/1oFYDB7g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=KWIflzrU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="KWIflzrU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4464C433C7; Thu, 4 Apr 2024 01:34:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1712194493; bh=Tu7snND44euMQoi+uvf+b5FVigQnGX2HHS6AqFbUpL0=; h=Date:To:From:Subject:From; b=KWIflzrUp3Ydz6IeFesKGPj7J3G5FoI5RnVgs3F7XJqblocfsRFSjggG5zC2zFKDT kKuXjt78VzfmQFh35m1TOiMiS4aYz98VcGmMmaLDwA2SWLycPQq97qiqTGvrms8qjV mqGdOg0zxcMQSTiFv83iwLc3kd9AoVxwua01S5PI= Date: Wed, 03 Apr 2024 18:34:53 -0700 To: mm-commits@vger.kernel.org,dave.jiang@intel.com,dan.j.williams@intel.com,alison.schofield@intel.com,vishal.l.verma@intel.com,akpm@linux-foundation.org From: Andrew Morton Subject: + dax-busc-replace-warn_on_once-with-lockdep-asserts.patch added to mm-unstable branch Message-Id: <20240404013453.D4464C433C7@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: dax/bus.c: replace WARN_ON_ONCE() with lockdep asserts has been added to the -mm mm-unstable branch. Its filename is dax-busc-replace-warn_on_once-with-lockdep-asserts.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/dax-busc-replace-warn_on_once-with-lockdep-asserts.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Vishal Verma Subject: dax/bus.c: replace WARN_ON_ONCE() with lockdep asserts Date: Tue, 02 Apr 2024 00:24:28 -0600 In [1], Dan points out that all of the WARN_ON_ONCE() usage in the referenced patch should be replaced with lockdep_assert_held(_write)(). Replace those, and additionally, replace a couple of other WARN_ON_ONCE() introduced in the same patch for actual failure cases (i.e. when acquiring a semaphore fails in a remove / unregister path) with dev_WARN_ONCE() as is the precedent here. Recall that previously, unregistration paths was implicitly protected by overloading the device lock, which the patch in [1] sought to remove. This meant adding a semaphore acquisition in these unregistration paths. Since that can fail, and it doesn't make sense to return errors from these paths, retain the two instances of (now) dev_WARN_ONCE(). Link: https://lore.kernel.org/r/65f0b5ef41817_aa222941a@dwillia2-mobl3.amr.corp.intel.com.notmuch [1] Link: https://lkml.kernel.org/r/20240402-vv-dax_abi_fixes-v1-1-c3e0fdbafba5@intel.com Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem") Signed-off-by: Vishal Verma Reported-by: Dan Williams Cc: Alison Schofield Cc: Dave Jiang Signed-off-by: Andrew Morton --- drivers/dax/bus.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) --- a/drivers/dax/bus.c~dax-busc-replace-warn_on_once-with-lockdep-asserts +++ a/drivers/dax/bus.c @@ -192,7 +192,7 @@ static u64 dev_dax_size(struct dev_dax * u64 size = 0; int i; - WARN_ON_ONCE(!rwsem_is_locked(&dax_dev_rwsem)); + lockdep_assert_held(&dax_dev_rwsem); for (i = 0; i < dev_dax->nr_range; i++) size += range_len(&dev_dax->ranges[i].range); @@ -302,7 +302,7 @@ static unsigned long long dax_region_ava resource_size_t size = resource_size(&dax_region->res); struct resource *res; - WARN_ON_ONCE(!rwsem_is_locked(&dax_region_rwsem)); + lockdep_assert_held(&dax_region_rwsem); for_each_dax_region_resource(dax_region, res) size -= resource_size(res); @@ -447,7 +447,7 @@ static void trim_dev_dax_range(struct de struct range *range = &dev_dax->ranges[i].range; struct dax_region *dax_region = dev_dax->region; - WARN_ON_ONCE(!rwsem_is_locked(&dax_region_rwsem)); + lockdep_assert_held_write(&dax_region_rwsem); dev_dbg(&dev_dax->dev, "delete range[%d]: %#llx:%#llx\n", i, (unsigned long long)range->start, (unsigned long long)range->end); @@ -471,6 +471,7 @@ static void __unregister_dev_dax(void *d dev_dbg(dev, "%s\n", __func__); + lockdep_assert_held_write(&dax_region_rwsem); kill_dev_dax(dev_dax); device_del(dev); free_dev_dax_ranges(dev_dax); @@ -482,7 +483,8 @@ static void unregister_dev_dax(void *dev if (rwsem_is_locked(&dax_region_rwsem)) return __unregister_dev_dax(dev); - if (WARN_ON_ONCE(down_write_killable(&dax_region_rwsem) != 0)) + if (dev_WARN_ONCE(dev, down_write_killable(&dax_region_rwsem) != 0, + "unable to acquire region rwsem\n")) return; __unregister_dev_dax(dev); up_write(&dax_region_rwsem); @@ -507,7 +509,7 @@ static int __free_dev_dax_id(struct dev_ struct dax_region *dax_region; int rc = dev_dax->id; - WARN_ON_ONCE(!rwsem_is_locked(&dax_dev_rwsem)); + lockdep_assert_held_write(&dax_dev_rwsem); if (!dev_dax->dyn_id || dev_dax->id < 0) return -1; @@ -713,7 +715,7 @@ static void __unregister_dax_mapping(voi dev_dbg(dev, "%s\n", __func__); - WARN_ON_ONCE(!rwsem_is_locked(&dax_region_rwsem)); + lockdep_assert_held_write(&dax_region_rwsem); dev_dax->ranges[mapping->range_id].mapping = NULL; mapping->range_id = -1; @@ -726,7 +728,8 @@ static void unregister_dax_mapping(void if (rwsem_is_locked(&dax_region_rwsem)) return __unregister_dax_mapping(data); - if (WARN_ON_ONCE(down_write_killable(&dax_region_rwsem) != 0)) + if (dev_WARN_ONCE(data, down_write_killable(&dax_region_rwsem) != 0, + "unable to acquire region rwsem\n")) return; __unregister_dax_mapping(data); up_write(&dax_region_rwsem); @@ -830,7 +833,7 @@ static int devm_register_dax_mapping(str struct device *dev; int rc; - WARN_ON_ONCE(!rwsem_is_locked(&dax_region_rwsem)); + lockdep_assert_held_write(&dax_region_rwsem); if (dev_WARN_ONCE(&dev_dax->dev, !dax_region->dev->driver, "region disabled\n")) @@ -876,7 +879,7 @@ static int alloc_dev_dax_range(struct de struct resource *alloc; int i, rc; - WARN_ON_ONCE(!rwsem_is_locked(&dax_region_rwsem)); + lockdep_assert_held_write(&dax_region_rwsem); /* handle the seed alloc special case */ if (!size) { @@ -935,7 +938,7 @@ static int adjust_dev_dax_range(struct d struct device *dev = &dev_dax->dev; int rc; - WARN_ON_ONCE(!rwsem_is_locked(&dax_region_rwsem)); + lockdep_assert_held_write(&dax_region_rwsem); if (dev_WARN_ONCE(dev, !size, "deletion is handled by dev_dax_shrink\n")) return -EINVAL; _ Patches currently in -mm which might be from vishal.l.verma@intel.com are dax-busc-replace-warn_on_once-with-lockdep-asserts.patch