From patchwork Wed Dec 5 12:28:27 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goldwyn Rodrigues X-Patchwork-Id: 10713979 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 F1EAA14E2 for ; Wed, 5 Dec 2018 12:28:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E22AE2C78C for ; Wed, 5 Dec 2018 12:28:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D62F02CB4D; Wed, 5 Dec 2018 12:28:58 +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=ham 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 6A0C72C78C for ; Wed, 5 Dec 2018 12:28:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727680AbeLEM25 (ORCPT ); Wed, 5 Dec 2018 07:28:57 -0500 Received: from mx2.suse.de ([195.135.220.15]:48450 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727525AbeLEM25 (ORCPT ); Wed, 5 Dec 2018 07:28:57 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id C1BF0ADA9 for ; Wed, 5 Dec 2018 12:28:54 +0000 (UTC) From: Goldwyn Rodrigues To: linux-btrfs@vger.kernel.org Cc: Goldwyn Rodrigues Subject: [PATCH 02/10] btrfs: basic dax read Date: Wed, 5 Dec 2018 06:28:27 -0600 Message-Id: <20181205122835.19290-3-rgoldwyn@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20181205122835.19290-1-rgoldwyn@suse.de> References: <20181205122835.19290-1-rgoldwyn@suse.de> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Goldwyn Rodrigues Signed-off-by: Goldwyn Rodrigues --- fs/btrfs/Makefile | 1 + fs/btrfs/ctree.h | 5 ++++ fs/btrfs/dax.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/file.c | 13 ++++++++++- 4 files changed, 86 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 5cc470fa6a40..038d64ecebe5 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3685,6 +3685,11 @@ 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..d614bf73bf8e --- /dev/null +++ b/fs/btrfs/dax.c @@ -0,0 +1,68 @@ +#include +#include +#include "ctree.h" +#include "btrfs_inode.h" + +static ssize_t em_dax_rw(struct inode *inode, struct extent_map *em, u64 pos, + u64 len, struct iov_iter *iter) +{ + struct dax_device *dax_dev = fs_dax_get_by_bdev(em->bdev); + ssize_t map_len; + pgoff_t blk_pg; + void *kaddr; + sector_t blk_start; + unsigned offset = pos & (PAGE_SIZE - 1); + + len = min(len + offset, em->len - (pos - em->start)); + len = ALIGN(len, PAGE_SIZE); + blk_start = (get_start_sect(em->bdev) << 9) + (em->block_start + (pos - em->start)); + blk_pg = blk_start - offset; + map_len = dax_direct_access(dax_dev, PHYS_PFN(blk_pg), PHYS_PFN(len), &kaddr, NULL); + map_len = PFN_PHYS(map_len); + kaddr += offset; + map_len -= offset; + if (map_len > len) + map_len = len; + if (iov_iter_rw(iter) == WRITE) + return dax_copy_from_iter(dax_dev, blk_pg, kaddr, map_len, iter); + else + return dax_copy_to_iter(dax_dev, blk_pg, kaddr, map_len, iter); +} + +ssize_t btrfs_file_dax_read(struct kiocb *iocb, struct iov_iter *to) +{ + size_t ret = 0, done = 0, count = iov_iter_count(to); + struct extent_map *em; + u64 pos = iocb->ki_pos; + u64 end = pos + count; + struct inode *inode = file_inode(iocb->ki_filp); + + if (!count) + return 0; + + end = i_size_read(inode) < end ? i_size_read(inode) : end; + + while (pos < end) { + u64 len = end - pos; + + em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, pos, len, 0); + if (IS_ERR(em)) { + if (!ret) + ret = PTR_ERR(em); + goto out; + } + + BUG_ON(em->flags & EXTENT_FLAG_FS_MAPPING); + + ret = em_dax_rw(inode, em, pos, len, to); + if (ret < 0) + goto out; + pos += ret; + done += ret; + } + +out: + iocb->ki_pos += done; + return done ? done : ret; +} + diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 58e93bce3036..ef6ed93f44d1 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -3308,9 +3308,20 @@ 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) +{ + struct inode *inode = file_inode(iocb->ki_filp); + +#ifdef CONFIG_FS_DAX + if (IS_DAX(inode)) + 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,