From patchwork Mon Apr 29 17:26:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goldwyn Rodrigues X-Patchwork-Id: 10922275 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 B1B5A14B6 for ; Mon, 29 Apr 2019 17:27:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9AA8D2883B for ; Mon, 29 Apr 2019 17:27:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8F621288BC; Mon, 29 Apr 2019 17:27:39 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2B7C428849 for ; Mon, 29 Apr 2019 17:27:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728882AbfD2R1P (ORCPT ); Mon, 29 Apr 2019 13:27:15 -0400 Received: from mx2.suse.de ([195.135.220.15]:58054 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728798AbfD2R1O (ORCPT ); Mon, 29 Apr 2019 13:27:14 -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 E5F2DAD78; Mon, 29 Apr 2019 17:27:11 +0000 (UTC) From: Goldwyn Rodrigues To: linux-btrfs@vger.kernel.org Cc: kilobyte@angband.pl, linux-fsdevel@vger.kernel.org, jack@suse.cz, david@fromorbit.com, willy@infradead.org, hch@lst.de, darrick.wong@oracle.com, dsterba@suse.cz, nborisov@suse.com, linux-nvdimm@lists.01.org, Goldwyn Rodrigues Subject: [PATCH 03/18] btrfs: basic dax read Date: Mon, 29 Apr 2019 12:26:34 -0500 Message-Id: <20190429172649.8288-4-rgoldwyn@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20190429172649.8288-1-rgoldwyn@suse.de> References: <20190429172649.8288-1-rgoldwyn@suse.de> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Goldwyn Rodrigues Perform a basic read using iomap support. The btrfs_iomap_begin() finds the extent at the position and fills the iomap data structure with the values. Signed-off-by: Goldwyn Rodrigues --- fs/btrfs/Makefile | 1 + fs/btrfs/ctree.h | 5 +++++ fs/btrfs/dax.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/file.c | 11 ++++++++++- 4 files changed, 65 insertions(+), 1 deletion(-) create mode 100644 fs/btrfs/dax.c diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index ca693dd554e9..1fa77b875ae9 100644 --- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -12,6 +12,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \ reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \ uuid-tree.o props.o free-space-tree.o tree-checker.o +btrfs-$(CONFIG_FS_DAX) += dax.o btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o btrfs-$(CONFIG_BTRFS_FS_REF_VERIFY) += ref-verify.o diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 9512f49262dd..b7bbe5130a3b 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3795,6 +3795,11 @@ int btrfs_reada_wait(void *handle); void btrfs_reada_detach(void *handle); int btree_readahead_hook(struct extent_buffer *eb, int err); +#ifdef CONFIG_FS_DAX +/* dax.c */ +ssize_t btrfs_file_dax_read(struct kiocb *iocb, struct iov_iter *to); +#endif /* CONFIG_FS_DAX */ + static inline int is_fstree(u64 rootid) { if (rootid == BTRFS_FS_TREE_OBJECTID || diff --git a/fs/btrfs/dax.c b/fs/btrfs/dax.c new file mode 100644 index 000000000000..bf3d46b0acb6 --- /dev/null +++ b/fs/btrfs/dax.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DAX support for BTRFS + * + * Copyright (c) 2019 SUSE Linux + * Author: Goldwyn Rodrigues + */ + +#ifdef CONFIG_FS_DAX +#include +#include +#include "ctree.h" +#include "btrfs_inode.h" + +static int btrfs_iomap_begin(struct inode *inode, loff_t pos, + loff_t length, unsigned flags, struct iomap *iomap) +{ + struct extent_map *em; + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, pos, length, 0); + if (em->block_start == EXTENT_MAP_HOLE) { + iomap->type = IOMAP_HOLE; + return 0; + } + iomap->type = IOMAP_MAPPED; + iomap->bdev = em->bdev; + iomap->dax_dev = fs_info->dax_dev; + iomap->offset = em->start; + iomap->length = em->len; + iomap->addr = em->block_start; + return 0; +} + +static const struct iomap_ops btrfs_iomap_ops = { + .iomap_begin = btrfs_iomap_begin, +}; + +ssize_t btrfs_file_dax_read(struct kiocb *iocb, struct iov_iter *to) +{ + ssize_t ret; + struct inode *inode = file_inode(iocb->ki_filp); + + inode_lock_shared(inode); + ret = dax_iomap_rw(iocb, to, &btrfs_iomap_ops); + inode_unlock_shared(inode); + + return ret; +} +#endif /* CONFIG_FS_DAX */ diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 34fe8a58b0e9..9194591f9eea 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -3288,9 +3288,18 @@ static int btrfs_file_open(struct inode *inode, struct file *filp) return generic_file_open(inode, filp); } +static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ +#ifdef CONFIG_FS_DAX + if (IS_DAX(file_inode(iocb->ki_filp))) + return btrfs_file_dax_read(iocb, to); +#endif + return generic_file_read_iter(iocb, to); +} + const struct file_operations btrfs_file_operations = { .llseek = btrfs_file_llseek, - .read_iter = generic_file_read_iter, + .read_iter = btrfs_file_read_iter, .splice_read = generic_file_splice_read, .write_iter = btrfs_file_write_iter, .mmap = btrfs_file_mmap,