From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) (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 7667E344DBD; Mon, 1 Jun 2026 23:10:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780355444; cv=none; b=RmESF5Uu69w5XKez/2QUh2fazTU6nTvwLPnF7/7vaS/5nWBU5WFsU3S5m/1ebjXcjaDqEViS9eQi2rnDxVrP+vjn392kNzCT7AHkTsGQBugdDAqVRtaVsE6WtgKH9ihDLiMSP5RvsA+uJ2ymn+msWIl09Jrsj2mu7WKRHHNrLe8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780355444; c=relaxed/simple; bh=QkDDYHL1L9uH/stCYZ+/QN6adgi29Br4Kiq31HwRUV4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=cf6WCV/C6E0jWPmjgp6RBnl8YpSiwJofJiosytNI7yBS6OG0shwNFculUiAHihbetG1FxTpxyh5rbDXcs3Ijgzouu+hpKc3sgVyAFQlSEZeV/FxUtkfPwdXDCNHCtuBe3fv/AxRHG0GqZUbhD4e1da+29hUeqPkXhvlxb2DL6+4= 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=iyxi5jgy; arc=none smtp.client-ip=198.175.65.15 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="iyxi5jgy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1780355442; x=1811891442; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=QkDDYHL1L9uH/stCYZ+/QN6adgi29Br4Kiq31HwRUV4=; b=iyxi5jgyrueXTSzCq2LW2Ase6HvwxE6h206k0i22JpN9gazvHzX0CRt5 xjw5Gg90bwQAv4FxIKpuhjeZbJKrSKTP1GhWiPwkJurxZeEdCc/akSymB JnywNtRllQ7R9eBBfOQh7Y0AR65HFbohKqoT+VYpElqlgeZLsMny6ASgc yXcjPRb1cnLbqdmfhFf1VdDKN4IWMZPKeC9C+73ZaCTMnSCu1tYvTVYZR /N8XzseFo5nGwjT6KY07pjBKjX2IP/Ayf8/JGpgUVI6Tvyg+2WLK74cSJ YJiArMF6urD1lxnof0SuFEzrqT2nWgZsgAHrHp23cSwF/nR0c2fqA4t3j g==; X-CSE-ConnectionGUID: 5vbD5aaoTkKyZSm4px8tiQ== X-CSE-MsgGUID: lJYidNxMRBqbe84IDolZnA== X-IronPort-AV: E=McAfee;i="6800,10657,11804"; a="84750059" X-IronPort-AV: E=Sophos;i="6.24,182,1774335600"; d="scan'208";a="84750059" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jun 2026 16:10:41 -0700 X-CSE-ConnectionGUID: z0Lr6ZjySLGR0UFlVJ1g6g== X-CSE-MsgGUID: vEbU0vCUSgOHdbGEdh433A== X-ExtLoop1: 1 Received: from bradocaj-mobl.ger.corp.intel.com (HELO [10.125.108.24]) ([10.125.108.24]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jun 2026 16:10:38 -0700 Message-ID: <26189ee7-1fba-49c2-94f5-0902a77772ba@intel.com> Date: Mon, 1 Jun 2026 16:10:37 -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 4/9] dax/fsdev: clear dev_dax->pgmap on probe failure 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> <20260530165053.6653-1-john@jagalactic.com> <0100019e79cbc3fa-cdb45b69-de84-4cc0-8aeb-71d0673c1a9c-000000@email.amazonses.com> Content-Language: en-US From: Dave Jiang In-Reply-To: <0100019e79cbc3fa-cdb45b69-de84-4cc0-8aeb-71d0673c1a9c-000000@email.amazonses.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/30/26 9:50 AM, John Groves wrote: > From: John Groves > > Clear dev_dax->pgmap on probe failure for dynamic devices. After the dynamic > path sets dev_dax->pgmap, if a later probe step fails, devres frees the > devm_kzalloc'd pgmap but leaves dev_dax->pgmap dangling. Subsequent probe > attempts would hit the "dynamic-dax with pre-populated page map" check and fail > permanently. Use a goto cleanup to NULL dev_dax->pgmap on error. > > Fixes: d5406bd458b0a ("dax: add fsdev.c driver for fs-dax on character dax") > Signed-off-by: John Groves > --- > drivers/dax/fsdev.c | 32 +++++++++++++++++++++++--------- > 1 file changed, 23 insertions(+), 9 deletions(-) > > diff --git a/drivers/dax/fsdev.c b/drivers/dax/fsdev.c > index dbd722ed7ab05..42aac7e952516 100644 > --- a/drivers/dax/fsdev.c > +++ b/drivers/dax/fsdev.c > @@ -223,6 +223,7 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax) > { > struct dax_device *dax_dev = dev_dax->dax_dev; > struct device *dev = &dev_dax->dev; > + bool pgmap_allocated = false; > struct dev_pagemap *pgmap; > struct inode *inode; > u64 data_offset = 0; > @@ -253,6 +254,7 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax) > > pgmap->nr_range = dev_dax->nr_range; > dev_dax->pgmap = pgmap; > + pgmap_allocated = true; > > for (i = 0; i < dev_dax->nr_range; i++) { > struct range *range = &dev_dax->ranges[i].range; > @@ -268,7 +270,8 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax) > range_len(range), dev_name(dev))) { > dev_warn(dev, "mapping%d: %#llx-%#llx could not reserve range\n", > i, range->start, range->end); > - return -EBUSY; > + rc = -EBUSY; > + goto err_pgmap; > } > } > > @@ -288,8 +291,10 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax) > pgmap->owner = dev_dax; > > addr = devm_memremap_pages(dev, pgmap); > - if (IS_ERR(addr)) > - return PTR_ERR(addr); > + if (IS_ERR(addr)) { > + rc = PTR_ERR(addr); > + goto err_pgmap; > + } > > /* > * Clear any stale compound folio state left over from a previous > @@ -301,7 +306,7 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax) > rc = devm_add_action_or_reset(dev, fsdev_clear_folio_state_action, > dev_dax); > if (rc) > - return rc; > + goto err_pgmap; > > /* Detect whether the data is at a non-zero offset into the memory */ > if (pgmap->range.start != dev_dax->ranges[0].range.start) { > @@ -323,23 +328,32 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax) > cdev_set_parent(cdev, &dev->kobj); > rc = cdev_add(cdev, dev->devt, 1); > if (rc) > - return rc; > + goto err_pgmap; > > rc = devm_add_action_or_reset(dev, fsdev_cdev_del, cdev); > if (rc) > - return rc; > + goto err_pgmap; > > /* Set the dax operations for fs-dax access path */ > rc = dax_set_ops(dax_dev, &dev_dax_ops); > if (rc) > - return rc; > + goto err_pgmap; > > rc = devm_add_action_or_reset(dev, fsdev_clear_ops, dev_dax); > if (rc) > - return rc; > + goto err_pgmap; > > run_dax(dax_dev); > - return devm_add_action_or_reset(dev, fsdev_kill, dev_dax); > + rc = devm_add_action_or_reset(dev, fsdev_kill, dev_dax); > + if (rc) > + goto err_pgmap; > + > + return 0; > + > +err_pgmap: > + if (pgmap_allocated) > + dev_dax->pgmap = NULL; > + return rc; > } > > static struct dax_device_driver fsdev_dax_driver = { How about something like this to ditch the gotos? --- diff --git a/drivers/dax/fsdev.c b/drivers/dax/fsdev.c index dbd722ed7ab0..cb309847e685 100644 --- a/drivers/dax/fsdev.c +++ b/drivers/dax/fsdev.c @@ -219,6 +219,41 @@ static const struct file_operations fsdev_fops = { .release = fsdev_release, }; +static struct dev_pagemap *fsdev_acquire_pgmap(struct dev_dax *dev_dax) +{ + struct device *dev = &dev_dax->dev; + struct dev_pagemap *pgmap; + size_t pgmap_size; + + if (static_dev_dax(dev_dax)) { + if (dev_dax->nr_range > 1) { + dev_warn(dev, + "static vs multi-range device conflict\n"); + return ERR_PTR(-EINVAL); + } + + pgmap = dev_dax->pgmap; + pgmap->vmemmap_shift = 0; + return pgmap; + } + + if (dev_dax->pgmap) { + dev_warn(dev, "dynamic-dax with pre-populated page map\n"); + return ERR_PTR(-EINVAL); + } + + pgmap_size = struct_size(pgmap, ranges, dev_dax->nr_range - 1); + pgmap = devm_kzalloc(dev, pgmap_size, GFP_KERNEL); + if (!pgmap) + return ERR_PTR(-ENOMEM); + + pgmap->nr_range = dev_dax->nr_range; + for (int i = 0; i < dev_dax->nr_range; i++) + pgmap->ranges[i] = dev_dax->ranges[i].range; + + return pgmap; +} + static int fsdev_dax_probe(struct dev_dax *dev_dax) { struct dax_device *dax_dev = dev_dax->dax_dev; @@ -230,36 +265,9 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax) void *addr; int rc, i; - if (static_dev_dax(dev_dax)) { - if (dev_dax->nr_range > 1) { - dev_warn(dev, "static pgmap / multi-range device conflict\n"); - return -EINVAL; - } - - pgmap = dev_dax->pgmap; - pgmap->vmemmap_shift = 0; - } else { - size_t pgmap_size; - - if (dev_dax->pgmap) { - dev_warn(dev, "dynamic-dax with pre-populated page map\n"); - return -EINVAL; - } - - pgmap_size = struct_size(pgmap, ranges, dev_dax->nr_range - 1); - pgmap = devm_kzalloc(dev, pgmap_size, GFP_KERNEL); - if (!pgmap) - return -ENOMEM; - - pgmap->nr_range = dev_dax->nr_range; - dev_dax->pgmap = pgmap; - - for (i = 0; i < dev_dax->nr_range; i++) { - struct range *range = &dev_dax->ranges[i].range; - - pgmap->ranges[i] = *range; - } - } + pgmap = fsdev_acquire_pgmap(dev_dax); + if (IS_ERR(pgmap)) + return PTR_ERR(pgmap); for (i = 0; i < dev_dax->nr_range; i++) { struct range *range = &dev_dax->ranges[i].range; @@ -306,7 +314,7 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax) /* Detect whether the data is at a non-zero offset into the memory */ if (pgmap->range.start != dev_dax->ranges[0].range.start) { u64 phys = dev_dax->ranges[0].range.start; - u64 pgmap_phys = dev_dax->pgmap[0].range.start; + u64 pgmap_phys = pgmap[0].range.start; if (!WARN_ON(pgmap_phys > phys)) data_offset = phys - pgmap_phys; @@ -339,7 +347,12 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax) return rc; run_dax(dax_dev); - return devm_add_action_or_reset(dev, fsdev_kill, dev_dax); + rc = devm_add_action_or_reset(dev, fsdev_kill, dev_dax); + if (rc) + return rc; + + dev_dax->pgmap = pgmap; + return 0; } static struct dax_device_driver fsdev_dax_driver = {