From patchwork Thu Oct 19 12:58:13 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 10016723 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 63CCB600CC for ; Thu, 19 Oct 2017 13:08:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3CD4C28D50 for ; Thu, 19 Oct 2017 13:08:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 31BF028D53; Thu, 19 Oct 2017 13:08:56 +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 C5B5E28D50 for ; Thu, 19 Oct 2017 13:08:55 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 8D46321EA15C4; Thu, 19 Oct 2017 06:05:06 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=195.135.220.15; helo=mx2.suse.de; envelope-from=jack@suse.cz; receiver=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 984ED21E87989 for ; Thu, 19 Oct 2017 06:05:04 -0700 (PDT) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id A7615AE8B; Thu, 19 Oct 2017 13:08:38 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 5EC1E1E35D9; Thu, 19 Oct 2017 15:00:08 +0200 (CEST) From: Jan Kara To: Subject: [PATCH 14/17] dax: Implement dax_finish_sync_fault() Date: Thu, 19 Oct 2017 14:58:13 +0200 Message-Id: <20171019125817.11580-15-jack@suse.cz> X-Mailer: git-send-email 2.12.3 In-Reply-To: <20171019125817.11580-1-jack@suse.cz> References: <20171019125817.11580-1-jack@suse.cz> X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Christoph Hellwig , Jan Kara , linux-nvdimm@lists.01.org, linux-api@vger.kernel.org, linux-xfs@vger.kernel.org, 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 Implement a function that filesystems can call to finish handling of synchronous page faults. It takes care of syncing appropriare file range and insertion of page table entry. Reviewed-by: Ross Zwisler Reviewed-by: Christoph Hellwig Signed-off-by: Jan Kara --- fs/dax.c | 83 +++++++++++++++++++++++++++++++++++++++++++ include/linux/dax.h | 2 ++ include/trace/events/fs_dax.h | 2 ++ 3 files changed, 87 insertions(+) diff --git a/fs/dax.c b/fs/dax.c index bb9ff907738c..78233c716757 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1492,3 +1492,86 @@ int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size, } } EXPORT_SYMBOL_GPL(dax_iomap_fault); + +/** + * dax_insert_pfn_mkwrite - insert PTE or PMD entry into page tables + * @vmf: The description of the fault + * @pe_size: Size of entry to be inserted + * @pfn: PFN to insert + * + * This function inserts writeable PTE or PMD entry into page tables for mmaped + * DAX file. It takes care of marking corresponding radix tree entry as dirty + * as well. + */ +static int dax_insert_pfn_mkwrite(struct vm_fault *vmf, + enum page_entry_size pe_size, + pfn_t pfn) +{ + struct address_space *mapping = vmf->vma->vm_file->f_mapping; + void *entry, **slot; + pgoff_t index = vmf->pgoff; + int vmf_ret, error; + + spin_lock_irq(&mapping->tree_lock); + entry = get_unlocked_mapping_entry(mapping, index, &slot); + /* Did we race with someone splitting entry or so? */ + if (!entry || + (pe_size == PE_SIZE_PTE && !dax_is_pte_entry(entry)) || + (pe_size == PE_SIZE_PMD && !dax_is_pmd_entry(entry))) { + put_unlocked_mapping_entry(mapping, index, entry); + spin_unlock_irq(&mapping->tree_lock); + trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf, + VM_FAULT_NOPAGE); + return VM_FAULT_NOPAGE; + } + radix_tree_tag_set(&mapping->page_tree, index, PAGECACHE_TAG_DIRTY); + entry = lock_slot(mapping, slot); + spin_unlock_irq(&mapping->tree_lock); + switch (pe_size) { + case PE_SIZE_PTE: + error = vm_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn); + vmf_ret = dax_fault_return(error); + break; +#ifdef CONFIG_FS_DAX_PMD + case PE_SIZE_PMD: + vmf_ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, + pfn, true); + break; +#endif + default: + vmf_ret = VM_FAULT_FALLBACK; + } + put_locked_mapping_entry(mapping, index); + trace_dax_insert_pfn_mkwrite(mapping->host, vmf, vmf_ret); + return vmf_ret; +} + +/** + * dax_finish_sync_fault - finish synchronous page fault + * @vmf: The description of the fault + * @pe_size: Size of entry to be inserted + * @pfn: PFN to insert + * + * This function ensures that the file range touched by the page fault is + * stored persistently on the media and handles inserting of appropriate page + * table entry. + */ +int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size, + pfn_t pfn) +{ + int err; + loff_t start = ((loff_t)vmf->pgoff) << PAGE_SHIFT; + size_t len = 0; + + if (pe_size == PE_SIZE_PTE) + len = PAGE_SIZE; + else if (pe_size == PE_SIZE_PMD) + len = PMD_SIZE; + else + WARN_ON_ONCE(1); + err = vfs_fsync_range(vmf->vma->vm_file, start, start + len - 1, 1); + if (err) + return VM_FAULT_SIGBUS; + return dax_insert_pfn_mkwrite(vmf, pe_size, pfn); +} +EXPORT_SYMBOL_GPL(dax_finish_sync_fault); diff --git a/include/linux/dax.h b/include/linux/dax.h index e7fa4b8f45bc..d403f78b706c 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -96,6 +96,8 @@ ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops); int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size, pfn_t *pfnp, const struct iomap_ops *ops); +int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size, + pfn_t pfn); int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index); int dax_invalidate_mapping_entry_sync(struct address_space *mapping, pgoff_t index); diff --git a/include/trace/events/fs_dax.h b/include/trace/events/fs_dax.h index 88a9d19b8ff8..7725459fafef 100644 --- a/include/trace/events/fs_dax.h +++ b/include/trace/events/fs_dax.h @@ -190,6 +190,8 @@ DEFINE_EVENT(dax_pte_fault_class, name, \ DEFINE_PTE_FAULT_EVENT(dax_pte_fault); DEFINE_PTE_FAULT_EVENT(dax_pte_fault_done); DEFINE_PTE_FAULT_EVENT(dax_load_hole); +DEFINE_PTE_FAULT_EVENT(dax_insert_pfn_mkwrite_no_entry); +DEFINE_PTE_FAULT_EVENT(dax_insert_pfn_mkwrite); TRACE_EVENT(dax_insert_mapping, TP_PROTO(struct inode *inode, struct vm_fault *vmf, void *radix_entry),