From patchwork Wed May 15 03:48:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 10944225 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2A3906C5 for ; Wed, 15 May 2019 04:02:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 15FA128885 for ; Wed, 15 May 2019 04:02:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 090B4288C7; Wed, 15 May 2019 04:02:41 +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 ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2E8BF28885 for ; Wed, 15 May 2019 04:02:39 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 9F900212777B4; Tue, 14 May 2019 21:02:39 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=192.55.52.93; helo=mga11.intel.com; envelope-from=dan.j.williams@intel.com; receiver=linux-nvdimm@lists.01.org Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 824B721260A75 for ; Tue, 14 May 2019 21:02:38 -0700 (PDT) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 May 2019 21:02:37 -0700 X-ExtLoop1: 1 Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by fmsmga005.fm.intel.com with ESMTP; 14 May 2019 21:02:36 -0700 Subject: [PATCH] dax: Arrange for dax_supported check to span multiple devices From: Dan Williams To: snitzer@redhat.com Date: Tue, 14 May 2019 20:48:49 -0700 Message-ID: <155789172402.748145.11853718580748830476.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-2-gc94f MIME-Version: 1.0 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jan Kara , linux-nvdimm@lists.01.org, Heiko Carstens , linux-kernel@vger.kernel.org, Matthew Wilcox , linux-fsdevel@vger.kernel.org, dm-devel@redhat.com, stable@vger.kernel.org, Martin Schwidefsky Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP Pankaj reports that starting with commit ad428cdb525a "dax: Check the end of the block-device capacity with dax_direct_access()" device-mapper no longer allows dax operation. This results from the stricter checks in __bdev_dax_supported() that validate that the start and end of a block-device map to the same 'pagemap' instance. Teach the dax-core and device-mapper to validate the 'pagemap' on a per-target basis. This is accomplished by refactoring the bdev_dax_supported() internals into generic_fsdax_supported() which takes a sector range to validate. Consequently generic_fsdax_supported() is suitable to be used in a device-mapper ->iterate_devices() callback. A new ->dax_supported() operation is added to allow composite devices to split and route upper-level bdev_dax_supported() requests. Fixes: ad428cdb525a ("dax: Check the end of the block-device...") Cc: Cc: Jan Kara Cc: Ira Weiny Cc: Dave Jiang Cc: Mike Snitzer Cc: Keith Busch Cc: Matthew Wilcox Cc: Vishal Verma Cc: Heiko Carstens Cc: Martin Schwidefsky Reported-by: Pankaj Gupta Signed-off-by: Dan Williams Reviewed-by: Jan Kara Reviewed-by: Mike Snitzer --- Hi Mike, Another day another new dax operation to allow device-mapper to better scope dax operations. Let me know if the device-mapper changes look sane. This passes a new unit test that indeed fails on current mainline. https://github.com/pmem/ndctl/blob/device-mapper-pending/test/dm.sh drivers/dax/super.c | 88 +++++++++++++++++++++++++++--------------- drivers/md/dm-table.c | 17 +++++--- drivers/md/dm.c | 20 ++++++++++ drivers/md/dm.h | 1 drivers/nvdimm/pmem.c | 1 drivers/s390/block/dcssblk.c | 1 include/linux/dax.h | 19 +++++++++ 7 files changed, 110 insertions(+), 37 deletions(-) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 0a339b85133e..ec2f2262e3a9 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -73,22 +73,12 @@ struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev); #endif -/** - * __bdev_dax_supported() - Check if the device supports dax for filesystem - * @bdev: block device to check - * @blocksize: The block size of the device - * - * This is a library function for filesystems to check if the block device - * can be mounted with dax option. - * - * Return: true if supported, false if unsupported - */ -bool __bdev_dax_supported(struct block_device *bdev, int blocksize) +bool generic_fsdax_supported(struct dax_device *dax_dev, + struct block_device *bdev, int blocksize, sector_t start, + sector_t sectors) { - struct dax_device *dax_dev; bool dax_enabled = false; pgoff_t pgoff, pgoff_end; - struct request_queue *q; char buf[BDEVNAME_SIZE]; void *kaddr, *end_kaddr; pfn_t pfn, end_pfn; @@ -102,21 +92,14 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize) return false; } - q = bdev_get_queue(bdev); - if (!q || !blk_queue_dax(q)) { - pr_debug("%s: error: request queue doesn't support dax\n", - bdevname(bdev, buf)); - return false; - } - - err = bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff); + err = bdev_dax_pgoff(bdev, start, PAGE_SIZE, &pgoff); if (err) { pr_debug("%s: error: unaligned partition for dax\n", bdevname(bdev, buf)); return false; } - last_page = PFN_DOWN(i_size_read(bdev->bd_inode) - 1) * 8; + last_page = PFN_DOWN((start + sectors - 1) * 512) * PAGE_SIZE / 512; err = bdev_dax_pgoff(bdev, last_page, PAGE_SIZE, &pgoff_end); if (err) { pr_debug("%s: error: unaligned partition for dax\n", @@ -124,20 +107,11 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize) return false; } - dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); - if (!dax_dev) { - pr_debug("%s: error: device does not support dax\n", - bdevname(bdev, buf)); - return false; - } - id = dax_read_lock(); len = dax_direct_access(dax_dev, pgoff, 1, &kaddr, &pfn); len2 = dax_direct_access(dax_dev, pgoff_end, 1, &end_kaddr, &end_pfn); dax_read_unlock(id); - put_dax(dax_dev); - if (len < 1 || len2 < 1) { pr_debug("%s: error: dax access failed (%ld)\n", bdevname(bdev, buf), len < 1 ? len : len2); @@ -178,6 +152,49 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize) } return true; } +EXPORT_SYMBOL_GPL(generic_fsdax_supported); + +/** + * __bdev_dax_supported() - Check if the device supports dax for filesystem + * @bdev: block device to check + * @blocksize: The block size of the device + * + * This is a library function for filesystems to check if the block device + * can be mounted with dax option. + * + * Return: true if supported, false if unsupported + */ +bool __bdev_dax_supported(struct block_device *bdev, int blocksize) +{ + struct dax_device *dax_dev; + struct request_queue *q; + char buf[BDEVNAME_SIZE]; + bool ret; + int id; + + q = bdev_get_queue(bdev); + if (!q || !blk_queue_dax(q)) { + pr_debug("%s: error: request queue doesn't support dax\n", + bdevname(bdev, buf)); + return false; + } + + dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); + if (!dax_dev) { + pr_debug("%s: error: device does not support dax\n", + bdevname(bdev, buf)); + return false; + } + + id = dax_read_lock(); + ret = dax_supported(dax_dev, bdev, blocksize, 0, + i_size_read(bdev->bd_inode) / 512); + dax_read_unlock(id); + + put_dax(dax_dev); + + return ret; +} EXPORT_SYMBOL_GPL(__bdev_dax_supported); #endif @@ -303,6 +320,15 @@ long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, } EXPORT_SYMBOL_GPL(dax_direct_access); +bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev, + int blocksize, sector_t start, sector_t len) +{ + if (!dax_alive(dax_dev)) + return false; + + return dax_dev->ops->dax_supported(dax_dev, bdev, blocksize, start, len); +} + size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i) { diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index cde3b49b2a91..350cf0451456 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -880,13 +880,17 @@ void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type) } EXPORT_SYMBOL_GPL(dm_table_set_type); +/* validate the dax capability of the target device span */ static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev, - sector_t start, sector_t len, void *data) + sector_t start, sector_t len, void *data) { - return bdev_dax_supported(dev->bdev, PAGE_SIZE); + int blocksize = *(int *) data; + + return generic_fsdax_supported(dev->dax_dev, dev->bdev, blocksize, + start, len); } -static bool dm_table_supports_dax(struct dm_table *t) +bool dm_table_supports_dax(struct dm_table *t, int blocksize) { struct dm_target *ti; unsigned i; @@ -899,7 +903,8 @@ static bool dm_table_supports_dax(struct dm_table *t) return false; if (!ti->type->iterate_devices || - !ti->type->iterate_devices(ti, device_supports_dax, NULL)) + !ti->type->iterate_devices(ti, device_supports_dax, + &blocksize)) return false; } @@ -979,7 +984,7 @@ static int dm_table_determine_type(struct dm_table *t) verify_bio_based: /* We must use this table as bio-based */ t->type = DM_TYPE_BIO_BASED; - if (dm_table_supports_dax(t) || + if (dm_table_supports_dax(t, PAGE_SIZE) || (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) { t->type = DM_TYPE_DAX_BIO_BASED; } else { @@ -1905,7 +1910,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, } blk_queue_write_cache(q, wc, fua); - if (dm_table_supports_dax(t)) + if (dm_table_supports_dax(t, PAGE_SIZE)) blk_queue_flag_set(QUEUE_FLAG_DAX, q); else blk_queue_flag_clear(QUEUE_FLAG_DAX, q); diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 043f0761e4a0..c28787f5357b 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1105,6 +1105,25 @@ static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, return ret; } +static bool dm_dax_supported(struct dax_device *dax_dev, struct block_device *bdev, + int blocksize, sector_t start, sector_t len) +{ + struct mapped_device *md = dax_get_private(dax_dev); + struct dm_table *map; + int srcu_idx; + bool ret; + + map = dm_get_live_table(md, &srcu_idx); + if (!map) + return false; + + ret = dm_table_supports_dax(map, blocksize); + + dm_put_live_table(md, srcu_idx); + + return ret; +} + static size_t dm_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i) { @@ -3192,6 +3211,7 @@ static const struct block_device_operations dm_blk_dops = { static const struct dax_operations dm_dax_ops = { .direct_access = dm_dax_direct_access, + .dax_supported = dm_dax_supported, .copy_from_iter = dm_dax_copy_from_iter, .copy_to_iter = dm_dax_copy_to_iter, }; diff --git a/drivers/md/dm.h b/drivers/md/dm.h index 2d539b82ec08..e5e240bfa2d0 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -78,6 +78,7 @@ void dm_unlock_md_type(struct mapped_device *md); void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type); enum dm_queue_mode dm_get_md_type(struct mapped_device *md); struct target_type *dm_get_immutable_target_type(struct mapped_device *md); +bool dm_table_supports_dax(struct dm_table *t, int blocksize); int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t); diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 0279eb1da3ef..845c5b430cdd 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -295,6 +295,7 @@ static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, static const struct dax_operations pmem_dax_ops = { .direct_access = pmem_dax_direct_access, + .dax_supported = generic_fsdax_supported, .copy_from_iter = pmem_copy_from_iter, .copy_to_iter = pmem_copy_to_iter, }; diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c index 4e8aedd50cb0..d04d4378ca50 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -59,6 +59,7 @@ static size_t dcssblk_dax_copy_to_iter(struct dax_device *dax_dev, static const struct dax_operations dcssblk_dax_ops = { .direct_access = dcssblk_dax_direct_access, + .dax_supported = generic_fsdax_supported, .copy_from_iter = dcssblk_dax_copy_from_iter, .copy_to_iter = dcssblk_dax_copy_to_iter, }; diff --git a/include/linux/dax.h b/include/linux/dax.h index 0dd316a74a29..f5544fc62319 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -19,6 +19,12 @@ struct dax_operations { */ long (*direct_access)(struct dax_device *, pgoff_t, long, void **, pfn_t *); + /* + * Validate whether this device is usable as an fsdax backing + * device. + */ + bool (*dax_supported)(struct dax_device *, struct block_device *, int, + sector_t, sector_t); /* copy_from_iter: required operation for fs-dax direct-i/o */ size_t (*copy_from_iter)(struct dax_device *, pgoff_t, void *, size_t, struct iov_iter *); @@ -75,6 +81,10 @@ static inline bool bdev_dax_supported(struct block_device *bdev, int blocksize) return __bdev_dax_supported(bdev, blocksize); } +bool generic_fsdax_supported(struct dax_device *dax_dev, + struct block_device *bdev, int blocksize, sector_t start, + sector_t sectors); + static inline struct dax_device *fs_dax_get_by_host(const char *host) { return dax_get_by_host(host); @@ -99,6 +109,13 @@ static inline bool bdev_dax_supported(struct block_device *bdev, return false; } +static inline bool generic_fsdax_supported(struct dax_device *dax_dev, + struct block_device *bdev, int blocksize, sector_t start, + sector_t sectors) +{ + return false; +} + static inline struct dax_device *fs_dax_get_by_host(const char *host) { return NULL; @@ -142,6 +159,8 @@ bool dax_alive(struct dax_device *dax_dev); void *dax_get_private(struct dax_device *dax_dev); long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn); +bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev, + int blocksize, sector_t start, sector_t len); size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i); size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,