From patchwork Fri Oct 7 21:08:50 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ross Zwisler X-Patchwork-Id: 9367529 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 1A61D600C8 for ; Fri, 7 Oct 2016 21:09:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 07FA629837 for ; Fri, 7 Oct 2016 21:09:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F0BE829832; Fri, 7 Oct 2016 21:09:15 +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=-1.9 required=2.0 tests=BAYES_00, 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 7E07629832 for ; Fri, 7 Oct 2016 21:09:15 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id A989D1A1EC5; Fri, 7 Oct 2016 14:09:13 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 036371A1E93 for ; Fri, 7 Oct 2016 14:09:13 -0700 (PDT) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP; 07 Oct 2016 14:09:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos; i="5.31,456,1473145200"; d="scan'208"; a="1067599785" Received: from theros.lm.intel.com ([10.232.112.77]) by fmsmga002.fm.intel.com with ESMTP; 07 Oct 2016 14:09:12 -0700 From: Ross Zwisler To: linux-kernel@vger.kernel.org Subject: [PATCH v5 03/17] dax: remove buffer_size_valid() Date: Fri, 7 Oct 2016 15:08:50 -0600 Message-Id: <1475874544-24842-4-git-send-email-ross.zwisler@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1475874544-24842-1-git-send-email-ross.zwisler@linux.intel.com> References: <1475874544-24842-1-git-send-email-ross.zwisler@linux.intel.com> X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Theodore Ts'o , Matthew Wilcox , Dave Chinner , linux-nvdimm@lists.01.org, Christoph Hellwig , linux-xfs@vger.kernel.org, linux-mm@kvack.org, Andreas Dilger , Alexander Viro , Jan Kara , linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, Andrew Morton MIME-Version: 1.0 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP Now that ext4 properly sets bh.b_size when we call get_block() for a hole, rely on that value and remove the buffer_size_valid() sanity check. Signed-off-by: Ross Zwisler Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig --- fs/dax.c | 22 +--------------------- 1 file changed, 1 insertion(+), 21 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index cc025f8..9b9be8a 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -123,19 +123,6 @@ static bool buffer_written(struct buffer_head *bh) return buffer_mapped(bh) && !buffer_unwritten(bh); } -/* - * When ext4 encounters a hole, it returns without modifying the buffer_head - * which means that we can't trust b_size. To cope with this, we set b_state - * to 0 before calling get_block and, if any bit is set, we know we can trust - * b_size. Unfortunate, really, since ext4 knows precisely how long a hole is - * and would save us time calling get_block repeatedly. - */ -static bool buffer_size_valid(struct buffer_head *bh) -{ - return bh->b_state != 0; -} - - static sector_t to_sector(const struct buffer_head *bh, const struct inode *inode) { @@ -177,8 +164,6 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, rc = get_block(inode, block, bh, rw == WRITE); if (rc) break; - if (!buffer_size_valid(bh)) - bh->b_size = 1 << blkbits; bh_max = pos - first + bh->b_size; bdev = bh->b_bdev; /* @@ -1012,12 +997,7 @@ int dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, bdev = bh.b_bdev; - /* - * If the filesystem isn't willing to tell us the length of a hole, - * just fall back to PTEs. Calling get_block 512 times in a loop - * would be silly. - */ - if (!buffer_size_valid(&bh) || bh.b_size < PMD_SIZE) { + if (bh.b_size < PMD_SIZE) { dax_pmd_dbg(&bh, address, "allocated block too small"); return VM_FAULT_FALLBACK; }