From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.21]) (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 073CB380FF6; Mon, 1 Jun 2026 23:24:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.21 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780356267; cv=none; b=HCUJOy7TuBW8vAkpBwoYRZhrKy7QlCX+9YHBSFrUW//6Z25hOV4xVcTWCQsd1hvZ5nuh9LEKl1TlQtYV4djCdCb9BlVm6f1/CDUeCIZSl7Yswh8H5BejI59LJrOuswMpQOvfFAUif+yfMFEeoWLwdpQY5+NfmLg/QpIctKlNENo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780356267; c=relaxed/simple; bh=DfLQHO9ZEMPWPBpxjYs4hLwQre4GHwtiqeK4Tww/mv0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=G/Q9kCAxKYAcN/Fdef2fbc7grZlxg/QTgi67LeQCfMlSKXYDFpxTWlBGs67lvnBgToRCU8q5luMCvBKO47lHHONENHUyYf/fhh/EdWYz3w/BJE9IzY2OTWNZ/U8w9BdAY8yjKUDdG46qSyZPKAbEk7fgcbGr16kA3qvikZaauGo= 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=PBgE/eqJ; arc=none smtp.client-ip=198.175.65.21 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="PBgE/eqJ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1780356265; x=1811892265; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=DfLQHO9ZEMPWPBpxjYs4hLwQre4GHwtiqeK4Tww/mv0=; b=PBgE/eqJgF2ypvE3rRlD9e54Qq41mclGQUl8fA6Zu7GXJmR1fMIS6oI3 JgvnJYWMvD1gO45M0Y0qgoBR8t5A7XNuEVzbbnJOiUSkRcMR/KaMOM2+v VjE3G1NcSejXUSMkBTUFonDxatPzqgCnYarYk6qH23rf/RMtrLmd4d+jR P4Nf4FQ7kqaMt/8SI7STiPXqSBExkXc++TKjQG6wMaqtD7LyiK6LRaPUq niGTXWc4SUxvKawIlcYxA2AqW3G+4ryhY581KSiym44p4rpWw/uQdcr9B haGeU3Yl6DY0sPmbhUsm3DtrcdIpgo25Kd+5FOKGUWfcu2EjWrrSjtuUQ Q==; X-CSE-ConnectionGUID: dZn4Iw4GRzeMSKRsbFXMdA== X-CSE-MsgGUID: fGN0C/U6RmWK5BBneHBjmw== X-IronPort-AV: E=McAfee;i="6800,10657,11804"; a="81026241" X-IronPort-AV: E=Sophos;i="6.24,182,1774335600"; d="scan'208";a="81026241" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by orvoesa113.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jun 2026 16:24:24 -0700 X-CSE-ConnectionGUID: g8uOSbJtTQyK+i2f3tMqwQ== X-CSE-MsgGUID: qgmFUOBGQzCuG/+DUJ3SKQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,182,1774335600"; d="scan'208";a="242680950" Received: from bradocaj-mobl.ger.corp.intel.com (HELO [10.125.108.24]) ([10.125.108.24]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jun 2026 16:24:23 -0700 Message-ID: <39570927-b4f8-41e2-816b-e8a0a30abf2b@intel.com> Date: Mon, 1 Jun 2026 16:24:21 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V3 5/9] dax/fsdev: use __va(phys) for kaddr in direct_access To: John Groves , John Groves , Dan Williams Cc: John Groves , Vishal Verma , Matthew Wilcox , Jan Kara , Alexander Viro , Christian Brauner , Miklos Szeredi , Alison Schofield , Ira Weiny , Jonathan Cameron , "nvdimm@lists.linux.dev" , "linux-cxl@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" References: <0100019e79caead2-5795328c-af48-4a93-b147-c11df7446e1a-000000@email.amazonses.com> <20260530165100.6670-1-john@jagalactic.com> <0100019e79cbe087-d11f77a7-379f-4355-b65c-52b3090e9ddd-000000@email.amazonses.com> Content-Language: en-US From: Dave Jiang In-Reply-To: <0100019e79cbe087-d11f77a7-379f-4355-b65c-52b3090e9ddd-000000@email.amazonses.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/30/26 9:51 AM, John Groves wrote: > From: John Groves > > Use __va(phys) instead of virt_addr + linear_offset for the kaddr > return in __fsdev_dax_direct_access(). The previous code added a > device-linear byte offset to virt_addr (which is __va of ranges[0]), > but for multi-range devices with physical gaps between ranges, this > linear arithmetic crosses the gap and produces a wrong kernel virtual > address. Using __va(phys) where phys comes from dax_pgoff_to_phys() > is correct for any range layout because the direct map translates > each physical address independently. > > Fixes: 759455848df0b ("dax: Save the kva from memremap") > Signed-off-by: John Groves Reviewed-by: Dave Jiang one comment below > --- > drivers/dax/fsdev.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) > > diff --git a/drivers/dax/fsdev.c b/drivers/dax/fsdev.c > index 42aac7e952516..a2d2eb20fb4d0 100644 > --- a/drivers/dax/fsdev.c > +++ b/drivers/dax/fsdev.c > @@ -51,9 +51,7 @@ static long __fsdev_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, > struct dev_dax *dev_dax = dax_get_private(dax_dev); > size_t size = nr_pages << PAGE_SHIFT; > size_t offset = pgoff << PAGE_SHIFT; > - void *virt_addr = dev_dax->virt_addr + offset; With this change, there's no more dev_dax->virt_addr usage? Should that be removed? DJ > phys_addr_t phys; > - unsigned long local_pfn; > > phys = dax_pgoff_to_phys(dev_dax, pgoff, size); > if (phys == -1) { > @@ -63,11 +61,10 @@ static long __fsdev_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, > } > > if (kaddr) > - *kaddr = virt_addr; > + *kaddr = __va(phys); > > - local_pfn = PHYS_PFN(phys); > if (pfn) > - *pfn = local_pfn; > + *pfn = PHYS_PFN(phys); > > /* > * Use cached_size which was computed at probe time. The size cannot