From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga18.intel.com ([134.134.136.126]:31806 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751551AbeEDAQj (ORCPT ); Thu, 3 May 2018 20:16:39 -0400 Subject: [PATCH v3 7/9] dax: report bytes remaining in dax_iomap_actor() From: Dan Williams To: linux-nvdimm@lists.01.org Cc: x86@kernel.org, Ingo Molnar , Borislav Petkov , Tony Luck , Al Viro , Thomas Gleixner , Andy Lutomirski , Peter Zijlstra , Andrew Morton , Linus Torvalds , hch@lst.de, linux-kernel@vger.kernel.org, tony.luck@intel.com, linux-fsdevel@vger.kernel.org Date: Thu, 03 May 2018 17:06:42 -0700 Message-ID: <152539240242.31796.4162676712193177396.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <152539236455.31796.7516599166555186700.stgit@dwillia2-desk3.amr.corp.intel.com> References: <152539236455.31796.7516599166555186700.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org List-ID: In preparation for protecting the dax read(2) path from media errors with copy_to_iter_mcsafe() (via dax_copy_to_iter()), convert the implementation to report the bytes successfully transferred. Cc: Cc: Ingo Molnar Cc: Borislav Petkov Cc: Tony Luck Cc: Al Viro Cc: Thomas Gleixner Cc: Andy Lutomirski Cc: Peter Zijlstra Cc: Andrew Morton Cc: Linus Torvalds Signed-off-by: Dan Williams --- fs/dax.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index a64afdf7ec0d..34a2d435ae4b 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -991,6 +991,7 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data, struct iov_iter *iter = data; loff_t end = pos + length, done = 0; ssize_t ret = 0; + size_t xfer; int id; if (iov_iter_rw(iter) == READ) { @@ -1054,19 +1055,20 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data, * vfs_write(), depending on which operation we are doing. */ if (iov_iter_rw(iter) == WRITE) - map_len = dax_copy_from_iter(dax_dev, pgoff, kaddr, + xfer = dax_copy_from_iter(dax_dev, pgoff, kaddr, map_len, iter); else - map_len = dax_copy_to_iter(dax_dev, pgoff, kaddr, + xfer = dax_copy_to_iter(dax_dev, pgoff, kaddr, map_len, iter); - if (map_len <= 0) { - ret = map_len ? map_len : -EFAULT; - break; - } - pos += map_len; - length -= map_len; - done += map_len; + pos += xfer; + length -= xfer; + done += xfer; + + if (xfer == 0) + ret = -EFAULT; + if (xfer < map_len) + break; } dax_read_unlock(id);