Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757234AbdDQTQB (ORCPT ); Mon, 17 Apr 2017 15:16:01 -0400 Received: from mga03.intel.com ([134.134.136.65]:20792 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757199AbdDQTPz (ORCPT ); Mon, 17 Apr 2017 15:15:55 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.37,215,1488873600"; d="scan'208";a="1120456505" Subject: [resend PATCH v2 14/33] Revert "block: use DAX for partition table reads" From: Dan Williams To: linux-nvdimm@ml01.01.org Cc: dm-devel@redhat.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Jeff Moyer , linux-fsdevel@vger.kernel.org, hch@lst.de Date: Mon, 17 Apr 2017 12:10:06 -0700 Message-ID: <149245620593.10206.1616718006783093047.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <149245612770.10206.15496018295337908594.stgit@dwillia2-desk3.amr.corp.intel.com> References: <149245612770.10206.15496018295337908594.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3656 Lines: 113 commit d1a5f2b4d8a1 ("block: use DAX for partition table reads") was part of a stalled effort to allow dax mappings of block devices. Since then the device-dax mechanism has filled the role of dax-mapping static device ranges. Now that we are moving ->direct_access() from a block_device operation to a dax_inode operation we would need block devices to map and carry their own dax_inode reference. Unless / until we decide to revive dax mapping of raw block devices through the dax_inode scheme, there is no need to carry read_dax_sector(). Its removal in turn allows for the removal of bdev_direct_access() and should have been included in commit 223757016837 ("block_dev: remove DAX leftovers"). Cc: Jeff Moyer Signed-off-by: Dan Williams --- block/partition-generic.c | 17 ++--------------- fs/dax.c | 20 -------------------- include/linux/dax.h | 6 ------ 3 files changed, 2 insertions(+), 41 deletions(-) diff --git a/block/partition-generic.c b/block/partition-generic.c index 7afb9907821f..5dfac337b0f2 100644 --- a/block/partition-generic.c +++ b/block/partition-generic.c @@ -16,7 +16,6 @@ #include #include #include -#include #include #include "partitions/check.h" @@ -631,24 +630,12 @@ int invalidate_partitions(struct gendisk *disk, struct block_device *bdev) return 0; } -static struct page *read_pagecache_sector(struct block_device *bdev, sector_t n) -{ - struct address_space *mapping = bdev->bd_inode->i_mapping; - - return read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_SHIFT-9)), - NULL); -} - unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p) { + struct address_space *mapping = bdev->bd_inode->i_mapping; struct page *page; - /* don't populate page cache for dax capable devices */ - if (IS_DAX(bdev->bd_inode)) - page = read_dax_sector(bdev, n); - else - page = read_pagecache_sector(bdev, n); - + page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_SHIFT-9)), NULL); if (!IS_ERR(page)) { if (PageError(page)) goto fail; diff --git a/fs/dax.c b/fs/dax.c index de622d4282a6..b78a6947c4f5 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -101,26 +101,6 @@ static int dax_is_empty_entry(void *entry) return (unsigned long)entry & RADIX_DAX_EMPTY; } -struct page *read_dax_sector(struct block_device *bdev, sector_t n) -{ - struct page *page = alloc_pages(GFP_KERNEL, 0); - struct blk_dax_ctl dax = { - .size = PAGE_SIZE, - .sector = n & ~((((int) PAGE_SIZE) / 512) - 1), - }; - long rc; - - if (!page) - return ERR_PTR(-ENOMEM); - - rc = dax_map_atomic(bdev, &dax); - if (rc < 0) - return ERR_PTR(rc); - memcpy_from_pmem(page_address(page), dax.addr, PAGE_SIZE); - dax_unmap_atomic(bdev, &dax); - return page; -} - /* * DAX radix tree locking */ diff --git a/include/linux/dax.h b/include/linux/dax.h index 7e62e280c11f..0d0d890f9186 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -70,15 +70,9 @@ void dax_wake_mapping_entry_waiter(struct address_space *mapping, pgoff_t index, void *entry, bool wake_all); #ifdef CONFIG_FS_DAX -struct page *read_dax_sector(struct block_device *bdev, sector_t n); int __dax_zero_page_range(struct block_device *bdev, sector_t sector, unsigned int offset, unsigned int length); #else -static inline struct page *read_dax_sector(struct block_device *bdev, - sector_t n) -{ - return ERR_PTR(-ENXIO); -} static inline int __dax_zero_page_range(struct block_device *bdev, sector_t sector, unsigned int offset, unsigned int length) {