From patchwork Wed Dec 5 12:28:33 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goldwyn Rodrigues X-Patchwork-Id: 10713991 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 55E2717D5 for ; Wed, 5 Dec 2018 12:29:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 465322CC55 for ; Wed, 5 Dec 2018 12:29:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3AA6C2CC85; Wed, 5 Dec 2018 12:29:12 +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 167162CC55 for ; Wed, 5 Dec 2018 12:29:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727803AbeLEM3K (ORCPT ); Wed, 5 Dec 2018 07:29:10 -0500 Received: from mx2.suse.de ([195.135.220.15]:48528 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727787AbeLEM3J (ORCPT ); Wed, 5 Dec 2018 07:29:09 -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 A4BDAAEB9 for ; Wed, 5 Dec 2018 12:29:07 +0000 (UTC) From: Goldwyn Rodrigues To: linux-btrfs@vger.kernel.org Cc: Goldwyn Rodrigues Subject: [PATCH 08/10] btrfs: dax add read mmap path Date: Wed, 5 Dec 2018 06:28:33 -0600 Message-Id: <20181205122835.19290-9-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/ctree.h | 1 + fs/btrfs/dax.c | 43 +++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/file.c | 12 +++++++++++- 3 files changed, 55 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index d91ff283a966..33648121ca52 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3694,6 +3694,7 @@ int btree_readahead_hook(struct extent_buffer *eb, int err); /* dax.c */ ssize_t btrfs_file_dax_read(struct kiocb *iocb, struct iov_iter *to); ssize_t btrfs_file_dax_write(struct kiocb *iocb, struct iov_iter *from); +vm_fault_t btrfs_dax_fault(struct vm_fault *vmf); #endif /* CONFIG_FS_DAX */ static inline int is_fstree(u64 rootid) diff --git a/fs/btrfs/dax.c b/fs/btrfs/dax.c index 4000259a426c..88017f8799d1 100644 --- a/fs/btrfs/dax.c +++ b/fs/btrfs/dax.c @@ -190,5 +190,48 @@ ssize_t btrfs_file_dax_write(struct kiocb *iocb, struct iov_iter *from) count - done, true); extent_changeset_free(data_reserved); return done ? done : ret; +} + +/* As copied from dax_iomap_pte_fault() */ +vm_fault_t btrfs_dax_fault(struct vm_fault *vmf) +{ + pfn_t pfn; + struct address_space *mapping = vmf->vma->vm_file->f_mapping; + XA_STATE(xas, &mapping->i_pages, vmf->pgoff); + struct inode *inode = mapping->host; + loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT; + void *entry = NULL; + vm_fault_t ret = 0; + + if (pos > i_size_read(inode)) { + ret = VM_FAULT_SIGBUS; + goto out; + } + entry = grab_mapping_entry(&xas, mapping, 0); + if (IS_ERR(entry)) { + ret = dax_fault_return(PTR_ERR(entry)); + goto out; + } + + if (!vmf->cow_page) { + sector_t sector; + struct extent_map *em; + em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, pos, PAGE_SIZE, 0); + if (em->block_start == EXTENT_MAP_HOLE) { + ret = dax_load_hole(&xas, mapping, entry, vmf); + goto out; + } + sector = ((get_start_sect(em->bdev) << 9) + + (em->block_start + (pos - em->start))) >> 9; + ret = dax_pfn(fs_dax_get_by_bdev(em->bdev), em->bdev, sector, PAGE_SIZE, &pfn); + if (ret) + goto out; + dax_insert_entry(&xas, mapping, vmf, entry, pfn, 0, false); + ret = vmf_insert_mixed(vmf->vma, vmf->address, pfn); + } +out: + if (entry) + dax_unlock_entry(&xas, entry); + return ret; } diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 29a3b12e6660..38b494686fb2 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -2227,8 +2227,18 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) return ret > 0 ? -EIO : ret; } +static vm_fault_t btrfs_fault(struct vm_fault *vmf) +{ + struct inode *inode = vmf->vma->vm_file->f_mapping->host; +#ifdef CONFIG_FS_DAX + if (IS_DAX(inode)) + return btrfs_dax_fault(vmf); +#endif + return filemap_fault(vmf); +} + static const struct vm_operations_struct btrfs_file_vm_ops = { - .fault = filemap_fault, + .fault = btrfs_fault, .map_pages = filemap_map_pages, .page_mkwrite = btrfs_page_mkwrite, };