From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A6CBEC10F14 for ; Tue, 16 Apr 2019 16:42:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7FDDF206B6 for ; Tue, 16 Apr 2019 16:42:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727052AbfDPQmm (ORCPT ); Tue, 16 Apr 2019 12:42:42 -0400 Received: from mx2.suse.de ([195.135.220.15]:36550 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730088AbfDPQmk (ORCPT ); Tue, 16 Apr 2019 12:42:40 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 389F0B112; Tue, 16 Apr 2019 16:42:39 +0000 (UTC) From: Goldwyn Rodrigues To: linux-btrfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, jack@suse.cz, david@fromorbit.com, willy@infradead.org, hch@lst.de, darrick.wong@oracle.com, kilobyte@angband.pl, dsterba@suse.cz, nborisov@suse.com, linux-nvdimm@lists.01.org, Goldwyn Rodrigues Subject: [PATCH 15/18] btrfs: handle dax page zeroing Date: Tue, 16 Apr 2019 11:41:51 -0500 Message-Id: <20190416164154.30390-16-rgoldwyn@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20190416164154.30390-1-rgoldwyn@suse.de> References: <20190416164154.30390-1-rgoldwyn@suse.de> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Goldwyn Rodrigues btrfs_dax_zero_block() zeros part of the page, either from the front or the regular rest of the block. Signed-off-by: Goldwyn Rodrigues --- fs/btrfs/ctree.h | 1 + fs/btrfs/dax.c | 27 ++++++++++++++++++++++++++- fs/btrfs/inode.c | 4 ++++ 3 files changed, 31 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index d3d044125619..ee1ed18f8b3c 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3806,6 +3806,7 @@ vm_fault_t btrfs_dax_fault(struct vm_fault *vmf); int btrfs_dax_file_range_compare(struct inode *src, loff_t srcoff, struct inode *dest, loff_t destoff, loff_t len, bool *is_same); +int btrfs_dax_zero_block(struct inode *inode, loff_t from, loff_t len, bool front); #else static inline ssize_t btrfs_file_dax_write(struct kiocb *iocb, struct iov_iter *from) { diff --git a/fs/btrfs/dax.c b/fs/btrfs/dax.c index a29628b403b3..a4b36d5b537c 100644 --- a/fs/btrfs/dax.c +++ b/fs/btrfs/dax.c @@ -132,7 +132,8 @@ static int btrfs_iomap_begin(struct inode *inode, loff_t pos, * This will be true for reads only since we have already * allocated em */ - if (em->block_start == EXTENT_MAP_HOLE) { + if (em->block_start == EXTENT_MAP_HOLE || + em->flags == EXTENT_FLAG_FILLING) { iomap->type = IOMAP_HOLE; return 0; } @@ -234,4 +235,28 @@ int btrfs_dax_file_range_compare(struct inode *src, loff_t srcoff, { return dax_file_range_compare(src, srcoff, dest, destoff, len, is_same, &btrfs_iomap_ops); } + +/* + * zero a part of the page only. This should CoW (via iomap_begin) if required + */ +int btrfs_dax_zero_block(struct inode *inode, loff_t from, loff_t len, bool front) +{ + loff_t start = round_down(from, PAGE_SIZE); + loff_t end = round_up(from, PAGE_SIZE); + loff_t offset = from; + int ret = 0; + + if (front) { + len = from - start; + offset = start; + } else { + if (!len) + len = end - from; + } + + if (len) + ret = iomap_zero_range(inode, offset, len, NULL, &btrfs_iomap_ops); + + return (ret < 0) ? ret : 0; +} #endif /* CONFIG_FS_DAX */ diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index c2c0544009a7..f6a64607bc8c 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4833,6 +4833,10 @@ int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len, (!len || IS_ALIGNED(len, blocksize))) goto out; +#ifdef CONFIG_FS_DAX + if (IS_DAX(inode)) + return btrfs_dax_zero_block(inode, from, len, front); +#endif block_start = round_down(from, blocksize); block_end = block_start + blocksize - 1; -- 2.16.4