From patchwork Thu Nov 24 09:46:36 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 9445059 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 45D4D60235 for ; Thu, 24 Nov 2016 09:47:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 47DC1277D9 for ; Thu, 24 Nov 2016 09:47:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3B68227C0C; Thu, 24 Nov 2016 09:47:10 +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 EE4CA277D9 for ; Thu, 24 Nov 2016 09:47:09 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id EA0C381EFA; Thu, 24 Nov 2016 01:47:09 -0800 (PST) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 581FB81EDD for ; Thu, 24 Nov 2016 01:47:09 -0800 (PST) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id E0BCCADCB; Thu, 24 Nov 2016 09:47:06 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 6EB0C1E2F93; Thu, 24 Nov 2016 10:46:53 +0100 (CET) From: Jan Kara To: Subject: [PATCH 6/6] ext4: Simplify DAX fault path Date: Thu, 24 Nov 2016 10:46:36 +0100 Message-Id: <1479980796-26161-7-git-send-email-jack@suse.cz> X-Mailer: git-send-email 2.6.6 In-Reply-To: <1479980796-26161-1-git-send-email-jack@suse.cz> References: <1479980796-26161-1-git-send-email-jack@suse.cz> 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: Jan Kara , linux-nvdimm@lists.01.org, linux-mm@kvack.org, Johannes Weiner , linux-ext4@vger.kernel.org MIME-Version: 1.0 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP Now that dax_iomap_fault() calls ->iomap_begin() without entry lock, we can use transaction starting in ext4_iomap_begin() and thus simplify ext4_dax_fault(). It also provides us proper retries in case of ENOSPC. Signed-off-by: Jan Kara --- fs/ext4/file.c | 48 ++++++++++-------------------------------------- 1 file changed, 10 insertions(+), 38 deletions(-) diff --git a/fs/ext4/file.c b/fs/ext4/file.c index b5f184493c57..d663d3d7c81c 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -258,7 +258,6 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from) static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { int result; - handle_t *handle = NULL; struct inode *inode = file_inode(vma->vm_file); struct super_block *sb = inode->i_sb; bool write = vmf->flags & FAULT_FLAG_WRITE; @@ -266,24 +265,12 @@ static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf) if (write) { sb_start_pagefault(sb); file_update_time(vma->vm_file); - down_read(&EXT4_I(inode)->i_mmap_sem); - handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE, - EXT4_DATA_TRANS_BLOCKS(sb)); - } else - down_read(&EXT4_I(inode)->i_mmap_sem); - - if (IS_ERR(handle)) - result = VM_FAULT_SIGBUS; - else - result = dax_iomap_fault(vma, vmf, &ext4_iomap_ops); - - if (write) { - if (!IS_ERR(handle)) - ext4_journal_stop(handle); - up_read(&EXT4_I(inode)->i_mmap_sem); + } + down_read(&EXT4_I(inode)->i_mmap_sem); + result = dax_iomap_fault(vma, vmf, &ext4_iomap_ops); + up_read(&EXT4_I(inode)->i_mmap_sem); + if (write) sb_end_pagefault(sb); - } else - up_read(&EXT4_I(inode)->i_mmap_sem); return result; } @@ -292,7 +279,6 @@ static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmd, unsigned int flags) { int result; - handle_t *handle = NULL; struct inode *inode = file_inode(vma->vm_file); struct super_block *sb = inode->i_sb; bool write = flags & FAULT_FLAG_WRITE; @@ -300,27 +286,13 @@ static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr, if (write) { sb_start_pagefault(sb); file_update_time(vma->vm_file); - down_read(&EXT4_I(inode)->i_mmap_sem); - handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE, - ext4_chunk_trans_blocks(inode, - PMD_SIZE / PAGE_SIZE)); - } else - down_read(&EXT4_I(inode)->i_mmap_sem); - - if (IS_ERR(handle)) - result = VM_FAULT_SIGBUS; - else { - result = dax_iomap_pmd_fault(vma, addr, pmd, flags, - &ext4_iomap_ops); } - - if (write) { - if (!IS_ERR(handle)) - ext4_journal_stop(handle); - up_read(&EXT4_I(inode)->i_mmap_sem); + down_read(&EXT4_I(inode)->i_mmap_sem); + result = dax_iomap_pmd_fault(vma, addr, pmd, flags, + &ext4_iomap_ops); + up_read(&EXT4_I(inode)->i_mmap_sem); + if (write) sb_end_pagefault(sb); - } else - up_read(&EXT4_I(inode)->i_mmap_sem); return result; }