From patchwork Tue Aug 18 17:14:47 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ross Zwisler X-Patchwork-Id: 7032691 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id D60FAC05AC for ; Tue, 18 Aug 2015 17:17:11 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D765020693 for ; Tue, 18 Aug 2015 17:17:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B5ACD206A7 for ; Tue, 18 Aug 2015 17:17:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753746AbbHRRQw (ORCPT ); Tue, 18 Aug 2015 13:16:52 -0400 Received: from mga09.intel.com ([134.134.136.24]:53412 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753639AbbHRRPG (ORCPT ); Tue, 18 Aug 2015 13:15:06 -0400 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga102.jf.intel.com with ESMTP; 18 Aug 2015 10:15:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,703,1432623600"; d="scan'208";a="786178024" Received: from theros.lm.intel.com ([10.232.112.155]) by fmsmga002.fm.intel.com with ESMTP; 18 Aug 2015 10:15:04 -0700 From: Ross Zwisler To: linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, Dan Williams , Christoph Hellwig , Matthew Wilcox , Dave Chinner Cc: Ross Zwisler , Alexander Viro , Matthew Wilcox , linux-fsdevel@vger.kernel.org Subject: [PATCH v4 6/7] dax: update I/O path to do proper PMEM flushing Date: Tue, 18 Aug 2015 11:14:47 -0600 Message-Id: <1439918088-32159-7-git-send-email-ross.zwisler@linux.intel.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1439918088-32159-1-git-send-email-ross.zwisler@linux.intel.com> References: <1439918088-32159-1-git-send-email-ross.zwisler@linux.intel.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-7.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Update the DAX I/O path so that all operations that store data (I/O writes, zeroing blocks, punching holes, etc.) properly synchronize the stores to media using the PMEM API. This ensures that the data DAX is writing is durable on media before the operation completes. Signed-off-by: Ross Zwisler Reviewed-by: Christoph Hellwig --- fs/dax.c | 44 +++++++++++++++++++++++++++++--------------- 1 file changed, 29 insertions(+), 15 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index b6769ce..680b44a 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -17,12 +17,14 @@ #include #include #include +#include #include #include #include #include #include #include +#include #include #include #include @@ -46,10 +48,7 @@ int dax_clear_blocks(struct inode *inode, sector_t block, long size) unsigned pgsz = PAGE_SIZE - offset_in_page(addr); if (pgsz > count) pgsz = count; - if (pgsz < PAGE_SIZE) - memset(addr, 0, pgsz); - else - clear_page(addr); + clear_pmem((void __pmem *)addr, pgsz); addr += pgsz; size -= pgsz; count -= pgsz; @@ -59,6 +58,7 @@ int dax_clear_blocks(struct inode *inode, sector_t block, long size) } } while (size); + wmb_pmem(); return 0; } EXPORT_SYMBOL_GPL(dax_clear_blocks); @@ -70,15 +70,16 @@ static long dax_get_addr(struct buffer_head *bh, void **addr, unsigned blkbits) return bdev_direct_access(bh->b_bdev, sector, addr, &pfn, bh->b_size); } +/* the clear_pmem() calls are ordered by a wmb_pmem() in the caller */ static void dax_new_buf(void *addr, unsigned size, unsigned first, loff_t pos, loff_t end) { loff_t final = end - pos + first; /* The final byte of the buffer */ if (first > 0) - memset(addr, 0, first); + clear_pmem((void __pmem *)addr, first); if (final < size) - memset(addr + final, 0, size - final); + clear_pmem((void __pmem *)addr + final, size - final); } static bool buffer_written(struct buffer_head *bh) @@ -108,12 +109,13 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, loff_t bh_max = start; void *addr; bool hole = false; + bool need_wmb = false; if (iov_iter_rw(iter) != WRITE) end = min(end, i_size_read(inode)); while (pos < end) { - unsigned len; + size_t len; if (pos == max) { unsigned blkbits = inode->i_blkbits; sector_t block = pos >> blkbits; @@ -145,18 +147,22 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, retval = dax_get_addr(bh, &addr, blkbits); if (retval < 0) break; - if (buffer_unwritten(bh) || buffer_new(bh)) + if (buffer_unwritten(bh) || buffer_new(bh)) { dax_new_buf(addr, retval, first, pos, end); + need_wmb = true; + } addr += first; size = retval - first; } max = min(pos + size, end); } - if (iov_iter_rw(iter) == WRITE) - len = copy_from_iter_nocache(addr, max - pos, iter); - else if (!hole) + if (iov_iter_rw(iter) == WRITE) { + len = copy_from_iter_pmem((void __pmem *)addr, + max - pos, iter); + need_wmb = true; + } else if (!hole) len = copy_to_iter(addr, max - pos, iter); else len = iov_iter_zero(max - pos, iter); @@ -168,6 +174,9 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, addr += len; } + if (need_wmb) + wmb_pmem(); + return (pos == start) ? retval : pos - start; } @@ -300,8 +309,10 @@ static int dax_insert_mapping(struct inode *inode, struct buffer_head *bh, goto out; } - if (buffer_unwritten(bh) || buffer_new(bh)) - clear_page(addr); + if (buffer_unwritten(bh) || buffer_new(bh)) { + clear_pmem((void __pmem *)addr, PAGE_SIZE); + wmb_pmem(); + } error = vm_insert_mixed(vma, vaddr, pfn); @@ -608,7 +619,9 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, if (buffer_unwritten(&bh) || buffer_new(&bh)) { int i; for (i = 0; i < PTRS_PER_PMD; i++) - clear_page(kaddr + i * PAGE_SIZE); + clear_pmem((void __pmem *)kaddr + i*PAGE_SIZE, + PAGE_SIZE); + wmb_pmem(); count_vm_event(PGMAJFAULT); mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT); result |= VM_FAULT_MAJOR; @@ -720,7 +733,8 @@ int dax_zero_page_range(struct inode *inode, loff_t from, unsigned length, err = dax_get_addr(&bh, &addr, inode->i_blkbits); if (err < 0) return err; - memset(addr + offset, 0, length); + clear_pmem((void __pmem *)addr + offset, length); + wmb_pmem(); } return 0;