From patchwork Tue Apr 2 06:24:28 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13613415 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) (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 3E10318654; Tue, 2 Apr 2024 06:24:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.19 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712039080; cv=none; b=pwQVGu53ywanmVIIkjA62pY2xWNGi0xG0zYvu485CEbSi7onv67fOsUJFQnMNIkfNjEFBvYbIZcAsfv5GO9/aVhkujBQamaBFvPB+aTbUT5wdIv0Eo9ivaV/qE4q3LNVEhcCjqKG7QyweVrB4qraqITPuUqQE5AfXacWZtEPDUI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712039080; c=relaxed/simple; bh=Avcgwic9to73qYuJOM9j0RdxPlc4XVJ76Q8h7Wk8SVw=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=ZQDTHGgqVj1/NM5tPjSvlSxR1dSheX0E2NqywO7NUuq5ssQ5f4oJew19BhICEMOQ/CbMvog+IoLAW8BFA5Jgv1gpXXZR0eN4cEMNy+ro5DpmHctvKuOO6/gEPJhAvsGJ4b1w44o93roRkx628XNl4h3c6QRHbrhEsdX+pFlgcuY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=b27jE85r; arc=none smtp.client-ip=198.175.65.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="b27jE85r" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1712039078; x=1743575078; h=from:date:subject:mime-version:content-transfer-encoding: message-id:to:cc; bh=Avcgwic9to73qYuJOM9j0RdxPlc4XVJ76Q8h7Wk8SVw=; b=b27jE85rimEtydns06rOqz73TOGE5LtJPzUqoE/vPCCtKBo2WiGkGxLx 2ljsSdn6hAJvBsEYxhthBE1v1q+X7vCtMe8b/Q9jQeIgtJDXIuy5uKGIT DRD/mMPLW7Q4AOnyEN0Z+Rxkk0SwlLv/ETt0sxJbNrHlsqvz0x33AZuXF 9fdIraWPdS9VlgCKgC/pMCsM0A7t3c/Q4qDRbyGIgN1EEiNEFRlqYuHls jDJO9ybt4/Y6jDn089vYA28VzLTZht1noVztDQGmIRJxzZuVZwmtQLEY+ ztfHQ3YFOQYw1OFo7l35mSS2W1TnZsfagM68Ev6e3YQyZr43E1pwevnqO g==; X-CSE-ConnectionGUID: /zZfD8keSGK7YtiULng4/Q== X-CSE-MsgGUID: yzMFefd8QoWfAE8nsTH8+Q== X-IronPort-AV: E=McAfee;i="6600,9927,11031"; a="7044663" X-IronPort-AV: E=Sophos;i="6.07,174,1708416000"; d="scan'208";a="7044663" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2024 23:24:37 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,174,1708416000"; d="scan'208";a="18040555" Received: from vverma7-desk1.amr.corp.intel.com (HELO [192.168.1.200]) ([10.212.66.53]) by fmviesa008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2024 23:24:37 -0700 From: Vishal Verma Date: Tue, 02 Apr 2024 00:24:28 -0600 Subject: [PATCH] dax/bus.c: replace WARN_ON_ONCE() with lockdep asserts Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240402-vv-dax_abi_fixes-v1-1-c3e0fdbafba5@intel.com> X-B4-Tracking: v=1; b=H4sIAJukC2YC/x3LTQqAIBBA4avIrBNs+iG6SoRMOdZsKhRECO+et Px4vBciB+EIs3ohcJIo91XRNgr2k66DtbhqQIO96Q3qlLSjbGkT6yVz1BP5bhu9Rx4I6vYE/kO 9lrWUD3zE2/hiAAAA To: Dan Williams , Dave Jiang , Alison Schofield , Andrew Morton Cc: linux-mm@kvack.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, Vishal Verma X-Mailer: b4 0.14-dev-5ce50 X-Developer-Signature: v=1; a=openpgp-sha256; l=5236; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=Avcgwic9to73qYuJOM9j0RdxPlc4XVJ76Q8h7Wk8SVw=; b=owGbwMvMwCXGf25diOft7jLG02pJDGncSxb4pTYHHd8tzN3jmrJ/kapw7kyTslmLJiQqZjJY7 0t7ztLWUcrCIMbFICumyPJ3z0fGY3Lb83kCExxh5rAygQxh4OIUgIlk3Gf4H8U1qX8DWxHjF+ut uqpvupjfJrvse8Wd3n+sUZnz9r+e9wx/5a8v4ZjPGzlToPeKjPel6sxFvMIa529F1DqbCFcka9/ kAwA= X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF 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] Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem") Cc: Andrew Morton Reported-by: Dan Williams Signed-off-by: Vishal Verma --- drivers/dax/bus.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) --- base-commit: 39cd87c4eb2b893354f3b850f916353f2658ae6f change-id: 20240402-vv-dax_abi_fixes-8af3b6ff2e5a Best regards, diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 797e1ebff299..d89c8c3b62f7 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -192,7 +192,7 @@ static u64 dev_dax_size(struct dev_dax *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_avail_size(struct dax_region *dax_region) 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 dev_dax *dev_dax) 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 *dev) 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_dax *dev_dax) 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(void *data) 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 *data) 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(struct dev_dax *dev_dax, int range_id) 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 dev_dax *dev_dax, u64 start, 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 dev_dax *dev_dax, struct resource *res, r 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;