From patchwork Wed May 23 05:10:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 10420163 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id EFC9D60327 for ; Wed, 23 May 2018 05:20:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DDFDB28E95 for ; Wed, 23 May 2018 05:20:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D2DDC2909E; Wed, 23 May 2018 05:20:34 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E69292909D for ; Wed, 23 May 2018 05:20:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DC48A6B0007; Wed, 23 May 2018 01:20:32 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id D72A16B0008; Wed, 23 May 2018 01:20:32 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C61466B000A; Wed, 23 May 2018 01:20:32 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-pg0-f69.google.com (mail-pg0-f69.google.com [74.125.83.69]) by kanga.kvack.org (Postfix) with ESMTP id 81DA56B0007 for ; Wed, 23 May 2018 01:20:32 -0400 (EDT) Received: by mail-pg0-f69.google.com with SMTP id e28-v6so2063488pgn.10 for ; Tue, 22 May 2018 22:20:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:subject:from :to:cc:date:message-id:in-reply-to:references:user-agent :mime-version:content-transfer-encoding; bh=fRU23vfxtHWn5cqggtVjESrTSQ30jEX1e5V0p5AwHrM=; b=poJEwmj/VvUCAp4ok3Eh9k61Jg6Yrp8kV5wtP8hYAl7jC/9HbesBJFTvARgwUMO0Ee aF3TariJZegmTNPKpTFDS2MJdCp3vakzanLyoXyQVQyUi97e1d/cXyC+Cn+haht0ExgR x3M7qYIBHgttgWUg2ZXX1IIlSHwz6HeuT5PZ60nKhVWH33v8Qc+tiy0ocSHsWUPf/5kw CvgkQRjeWiNghZiXhKfiZ54/iUgN/vpT4J6i0AXWw0BHTmKI/FPXfn2Q0DzqUJqNVeMv PICnqhav4GcwGJn+c5CKvRgNIZV2U/fYUOlXsAHSDUOFTLsyfI7rRlE5hXZR4VUpl8WR bxYA== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of dan.j.williams@intel.com designates 134.134.136.24 as permitted sender) smtp.mailfrom=dan.j.williams@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Gm-Message-State: ALKqPwfOB43Fd68kjFF9hszTBkkeEK3S+evIonNJ+ocJmEXmq1Kjp0W2 2xXAHeTiA41SwYj8gdLUMrWe8Mgpn4s+Zbp5vg1jXwcyer+zzBTtSFCR70ypsE1MQ9xclIZaZzN imYGa4jf6/wJceFeKysq7+pZuMywu6n4VI8MWEfCOy5IdWbsMg7vdRsk+yvgyT3riPQ== X-Received: by 2002:a65:5105:: with SMTP id f5-v6mr1157112pgq.232.1527052832149; Tue, 22 May 2018 22:20:32 -0700 (PDT) X-Google-Smtp-Source: AB8JxZpymvCLEySWFHqpyvpgV35n5YL1KMZvqMsdqCxMHOEkRswUEO7Jw37EcLlBFxd2WZri83fx X-Received: by 2002:a65:5105:: with SMTP id f5-v6mr1157075pgq.232.1527052831106; Tue, 22 May 2018 22:20:31 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1527052831; cv=none; d=google.com; s=arc-20160816; b=T5Hw7l4SgboiXel/Ass3FPoaU4BC3lrL+YU5Bp/hqXT7UI7JhL76nqoG4FQuxec8xG QewrVGLt50s2enqmGl1BouEMPQOsVF8rMMqakpequt9KCdWEBCshgUHKMAs7MfKtPvhL HozgmbXmTo5xOLmei6lFHnK72HHjcTzF5uvZu2YwF38GKAmPxnC4XKXysZ65kJ5Tb/jr TRcHET0fUL5VRK8UiNYFB5EeJUIoSr8u2cGbpON6EGxpD6H+jO6SEmBNQXudDN3O3u+2 Qw80ijyjjZ5/tKBh33+INJVF9fcb4grF2NP5KpOLnYtkeOKVCl6PizgK1PApqkBwq7Tj ZEHg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:user-agent:references :in-reply-to:message-id:date:cc:to:from:subject :arc-authentication-results; bh=fRU23vfxtHWn5cqggtVjESrTSQ30jEX1e5V0p5AwHrM=; b=BsljmSuXE1Ox/RRb5Rae+s0RfHVPdzlBzW8anbjJXs7toN4Z1iIajcSPy8xMdo4+yj e5k94vUz23hQSbFC+/fea2GzgRS39QWMjx+U+S7mqCd45FT4f3PE973djXKzjbGyH2Yh lzJXPr6GIRi2C7cBuGij2BWQXj98GodTPRtn2M3WR/RyDtg/Ps1tl0dX//ztan04bk4+ lSaPQqOLKNKf8lBq2Y6KQuHCjHCt4mG7ycUoycR/l+UavkYeH9NYmIsUkG9QRTaWJUuM dH7Tjr60iWF9hBvzC67A9ejg+vzAjZLZwlR0DHkz8zxp9Uym74HcqWBtgoWx227zRkLw pdvQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of dan.j.williams@intel.com designates 134.134.136.24 as permitted sender) smtp.mailfrom=dan.j.williams@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from mga09.intel.com (mga09.intel.com. [134.134.136.24]) by mx.google.com with ESMTPS id m2-v6si12602916pgm.306.2018.05.22.22.20.30 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 22 May 2018 22:20:31 -0700 (PDT) Received-SPF: pass (google.com: domain of dan.j.williams@intel.com designates 134.134.136.24 as permitted sender) client-ip=134.134.136.24; Authentication-Results: mx.google.com; spf=pass (google.com: domain of dan.j.williams@intel.com designates 134.134.136.24 as permitted sender) smtp.mailfrom=dan.j.williams@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 May 2018 22:20:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,431,1520924400"; d="scan'208";a="58260587" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by orsmga001.jf.intel.com with ESMTP; 22 May 2018 22:20:30 -0700 Subject: [PATCH v2 3/7] mm, devm_memremap_pages: Fix shutdown handling From: Dan Williams To: akpm@linux-foundation.org Cc: stable@vger.kernel.org, Christoph Hellwig , =?utf-8?b?SsOpcsO0bWU=?= Glisse , Logan Gunthorpe , linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Tue, 22 May 2018 22:10:34 -0700 Message-ID: <152705223396.21414.13388289577013917472.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <152705221686.21414.771870778478134768.stgit@dwillia2-desk3.amr.corp.intel.com> References: <152705221686.21414.771870778478134768.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-2-gc94f MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: X-Virus-Scanned: ClamAV using ClamSMTP The last step before devm_memremap_pages() returns success is to allocate a release action, devm_memremap_pages_release(), to tear the entire setup down. However, the result from devm_add_action() is not checked. Checking the error from devm_add_action() is not enough. The api currently relies on the fact that the percpu_ref it is using is killed by the time the devm_memremap_pages_release() is run. Rather than continue this awkward situation, offload the responsibility of killing the percpu_ref to devm_memremap_pages_release() directly. This allows devm_memremap_pages() to do the right thing relative to init failures and shutdown. Without this change we could fail to register the teardown of devm_memremap_pages(). The likelihood of hitting this failure is tiny as small memory allocations almost always succeed. However, the impact of the failure is large given any future reconfiguration, or disable/enable, of an nvdimm namespace will fail forever as subsequent calls to devm_memremap_pages() will fail to setup the pgmap_radix since there will be stale entries for the physical address range. Cc: Fixes: e8d513483300 ("memremap: change devm_memremap_pages interface...") Cc: Christoph Hellwig Cc: "Jérôme Glisse" Reported-by: Logan Gunthorpe Signed-off-by: Dan Williams --- drivers/dax/pmem.c | 10 ++-------- drivers/nvdimm/pmem.c | 18 ++++++++---------- include/linux/memremap.h | 7 +++++-- kernel/memremap.c | 36 +++++++++++++++++++----------------- tools/testing/nvdimm/test/iomap.c | 21 ++++++++++++++++++--- 5 files changed, 52 insertions(+), 40 deletions(-) diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c index fd49b24fd6af..54cba20c8ba6 100644 --- a/drivers/dax/pmem.c +++ b/drivers/dax/pmem.c @@ -48,9 +48,8 @@ static void dax_pmem_percpu_exit(void *data) percpu_ref_exit(ref); } -static void dax_pmem_percpu_kill(void *data) +static void dax_pmem_percpu_kill(struct percpu_ref *ref) { - struct percpu_ref *ref = data; struct dax_pmem *dax_pmem = to_dax_pmem(ref); dev_dbg(dax_pmem->dev, "trace\n"); @@ -111,15 +110,10 @@ static int dax_pmem_probe(struct device *dev) return rc; dax_pmem->pgmap.ref = &dax_pmem->ref; - addr = devm_memremap_pages(dev, &dax_pmem->pgmap); + addr = devm_memremap_pages(dev, &dax_pmem->pgmap, dax_pmem_percpu_kill); if (IS_ERR(addr)) return PTR_ERR(addr); - rc = devm_add_action_or_reset(dev, dax_pmem_percpu_kill, - &dax_pmem->ref); - if (rc) - return rc; - /* adjust the dax_region resource to the start of data */ memcpy(&res, &dax_pmem->pgmap.res, sizeof(res)); res.start += le64_to_cpu(pfn_sb->dataoff); diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 9d714926ecf5..49c9c1bab438 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -279,8 +279,11 @@ static void pmem_release_queue(void *q) blk_cleanup_queue(q); } -static void pmem_freeze_queue(void *q) +static void pmem_freeze_queue(struct percpu_ref *ref) { + struct request_queue *q; + + q = container_of(ref, typeof(*q), q_usage_counter); blk_freeze_queue_start(q); } @@ -353,7 +356,8 @@ static int pmem_attach_disk(struct device *dev, pmem->pfn_flags = PFN_DEV; pmem->pgmap.ref = &q->q_usage_counter; if (is_nd_pfn(dev)) { - addr = devm_memremap_pages(dev, &pmem->pgmap); + addr = devm_memremap_pages(dev, &pmem->pgmap, + pmem_freeze_queue); pfn_sb = nd_pfn->pfn_sb; pmem->data_offset = le64_to_cpu(pfn_sb->dataoff); pmem->pfn_pad = resource_size(res) - @@ -364,20 +368,14 @@ static int pmem_attach_disk(struct device *dev, } else if (pmem_should_map_pages(dev)) { memcpy(&pmem->pgmap.res, &nsio->res, sizeof(pmem->pgmap.res)); pmem->pgmap.altmap_valid = false; - addr = devm_memremap_pages(dev, &pmem->pgmap); + addr = devm_memremap_pages(dev, &pmem->pgmap, + pmem_freeze_queue); pmem->pfn_flags |= PFN_MAP; memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res)); } else addr = devm_memremap(dev, pmem->phys_addr, pmem->size, ARCH_MEMREMAP_PMEM); - /* - * At release time the queue must be frozen before - * devm_memremap_pages is unwound - */ - if (devm_add_action_or_reset(dev, pmem_freeze_queue, q)) - return -ENOMEM; - if (IS_ERR(addr)) return PTR_ERR(addr); pmem->virt_addr = addr; diff --git a/include/linux/memremap.h b/include/linux/memremap.h index 7b4899c06f49..b5e894133cf6 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -106,6 +106,7 @@ typedef void (*dev_page_free_t)(struct page *page, void *data); * @altmap: pre-allocated/reserved memory for vmemmap allocations * @res: physical address range covered by @ref * @ref: reference count that pins the devm_memremap_pages() mapping + * @kill: callback to transition @ref to the dead state * @dev: host device of the mapping for debug * @data: private data pointer for page_free() * @type: memory type: see MEMORY_* in memory_hotplug.h @@ -117,13 +118,15 @@ struct dev_pagemap { bool altmap_valid; struct resource res; struct percpu_ref *ref; + void (*kill)(struct percpu_ref *ref); struct device *dev; void *data; enum memory_type type; }; #ifdef CONFIG_ZONE_DEVICE -void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap); +void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap, + void (*kill)(struct percpu_ref *)); struct dev_pagemap *get_dev_pagemap(unsigned long pfn, struct dev_pagemap *pgmap); @@ -133,7 +136,7 @@ void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns); static inline bool is_zone_device_page(const struct page *page); #else static inline void *devm_memremap_pages(struct device *dev, - struct dev_pagemap *pgmap) + struct dev_pagemap *pgmap, void (*kill)(struct percpu_ref *)) { /* * Fail attempts to call devm_memremap_pages() without diff --git a/kernel/memremap.c b/kernel/memremap.c index dd11607671eb..dfec0801f652 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -293,14 +293,10 @@ static void devm_memremap_pages_release(void *data) resource_size_t align_start, align_size; unsigned long pfn; + pgmap->kill(pgmap->ref); for_each_device_pfn(pfn, pgmap) put_page(pfn_to_page(pfn)); - if (percpu_ref_tryget_live(pgmap->ref)) { - dev_WARN(dev, "%s: page mapping is still live!\n", __func__); - percpu_ref_put(pgmap->ref); - } - /* pages are dead and unused, undo the arch mapping */ align_start = res->start & ~(SECTION_SIZE - 1); align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE) @@ -320,7 +316,8 @@ static void devm_memremap_pages_release(void *data) /** * devm_memremap_pages - remap and provide memmap backing for the given resource * @dev: hosting device for @res - * @pgmap: pointer to a struct dev_pgmap + * @pgmap: pointer to a struct dev_pagemap + * @kill: routine to kill @pgmap->ref * * Notes: * 1/ At a minimum the res, ref and type members of @pgmap must be initialized @@ -329,17 +326,15 @@ static void devm_memremap_pages_release(void *data) * 2/ The altmap field may optionally be initialized, in which case altmap_valid * must be set to true * - * 3/ pgmap.ref must be 'live' on entry and 'dead' before devm_memunmap_pages() - * time (or devm release event). The expected order of events is that ref has - * been through percpu_ref_kill() before devm_memremap_pages_release(). The - * wait for the completion of all references being dropped and - * percpu_ref_exit() must occur after devm_memremap_pages_release(). + * 3/ pgmap->ref must be 'live' on entry and will be killed at + * devm_memremap_pages_release() time, or if this routine fails. * * 4/ res is expected to be a host memory range that could feasibly be * treated as a "System RAM" range, i.e. not a device mmio range, but * this is not enforced. */ -void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) +void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap, + void (*kill)(struct percpu_ref *)) { resource_size_t align_start, align_size, align_end; struct vmem_altmap *altmap = pgmap->altmap_valid ? @@ -349,6 +344,9 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) pgprot_t pgprot = PAGE_KERNEL; int error, nid, is_ram; + if (!pgmap->ref || !kill) + return ERR_PTR(-EINVAL); + align_start = res->start & ~(SECTION_SIZE - 1); align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE) - align_start; @@ -358,12 +356,10 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) if (is_ram != REGION_DISJOINT) { WARN_ONCE(1, "%s attempted on %s region %pr\n", __func__, is_ram == REGION_MIXED ? "mixed" : "ram", res); - return ERR_PTR(-ENXIO); + error = -ENXIO; + goto err_init; } - if (!pgmap->ref) - return ERR_PTR(-EINVAL); - pgmap->dev = dev; mutex_lock(&pgmap_lock); @@ -415,7 +411,11 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) percpu_ref_get(pgmap->ref); } - devm_add_action(dev, devm_memremap_pages_release, pgmap); + pgmap->kill = kill; + error = devm_add_action_or_reset(dev, devm_memremap_pages_release, + pgmap); + if (error) + return ERR_PTR(error); return __va(res->start); @@ -424,6 +424,8 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) err_pfn_remap: err_radix: pgmap_radix_release(res, pgoff); + err_init: + kill(pgmap->ref); return ERR_PTR(error); } EXPORT_SYMBOL_GPL(devm_memremap_pages); diff --git a/tools/testing/nvdimm/test/iomap.c b/tools/testing/nvdimm/test/iomap.c index ff9d3a5825e1..ad544e6476a9 100644 --- a/tools/testing/nvdimm/test/iomap.c +++ b/tools/testing/nvdimm/test/iomap.c @@ -104,14 +104,29 @@ void *__wrap_devm_memremap(struct device *dev, resource_size_t offset, } EXPORT_SYMBOL(__wrap_devm_memremap); -void *__wrap_devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) +static void nfit_test_kill(void *_pgmap) +{ + struct dev_pagemap *pgmap = _pgmap; + + pgmap->kill(pgmap->ref); +} + +void *__wrap_devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap, + void (*kill)(struct percpu_ref *)) { resource_size_t offset = pgmap->res.start; struct nfit_test_resource *nfit_res = get_nfit_res(offset); - if (nfit_res) + if (nfit_res) { + int rc; + + pgmap->kill = kill; + rc = devm_add_action_or_reset(dev, nfit_test_kill, pgmap); + if (rc) + return ERR_PTR(rc); return nfit_res->buf + offset - nfit_res->res.start; - return devm_memremap_pages(dev, pgmap); + } + return devm_memremap_pages(dev, pgmap, kill); } EXPORT_SYMBOL(__wrap_devm_memremap_pages);