From patchwork Sat Oct 13 00:07:44 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 10639629 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 813471869 for ; Sat, 13 Oct 2018 00:07:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5B8D12B794 for ; Sat, 13 Oct 2018 00:07:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4F6332B79F; Sat, 13 Oct 2018 00:07:53 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable 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 DA1A82B794 for ; Sat, 13 Oct 2018 00:07:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726870AbeJMHml (ORCPT ); Sat, 13 Oct 2018 03:42:41 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:34626 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726167AbeJMHml (ORCPT ); Sat, 13 Oct 2018 03:42:41 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w9D04VUQ143988; Sat, 13 Oct 2018 00:07:47 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : from : to : cc : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=hGJg7Mw2eDLP+J7yKVhYwcUJLtxNrIR1f+LqpGNW/UQ=; b=rr6AY7BYYBkvd8M4lgeVvqXmQnU6Ue9WmevUeehAkOKabX6x2z4Pu6mwXnUfHtFOfJKw svD1AuPIj9oqyd7loGDib3ppsbw6fpX5oBpLNucYdwEuWV05Jgn7Wz7vHv+l5ZRK/tEx JahBEhoV6Df1qubV/VrQ2dKpARFNPBxTaj0PZQcDPLgU6pwNben8sUnpsIaLsma+Ab2u C0/6u7ANd+bc6/2uXuIzE5LBqfWf/eFTM22uOHHH/3xVqUpvXxdJwlrr42NYnsR+tqEw 6zeL9IiWsUrN2IBGSuMX3RuPpokHlAAWzj4bpyZophwr54HUcCcMCYjDu/ptesrHExtO 8Q== Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by userp2130.oracle.com with ESMTP id 2mxmfudpyv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 13 Oct 2018 00:07:47 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id w9D07kQR025497 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 13 Oct 2018 00:07:46 GMT Received: from abhmp0005.oracle.com (abhmp0005.oracle.com [141.146.116.11]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w9D07kfm018360; Sat, 13 Oct 2018 00:07:46 GMT Received: from localhost (/10.159.251.254) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Sat, 13 Oct 2018 00:07:45 +0000 Subject: [PATCH 17/25] vfs: enable remap callers that can handle short operations From: "Darrick J. Wong" To: david@fromorbit.com, darrick.wong@oracle.com Cc: sandeen@redhat.com, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, Amir Goldstein , linux-unionfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, ocfs2-devel@oss.oracle.com Date: Fri, 12 Oct 2018 17:07:44 -0700 Message-ID: <153938926421.8361.13101766265446494393.stgit@magnolia> In-Reply-To: <153938912912.8361.13446310416406388958.stgit@magnolia> References: <153938912912.8361.13446310416406388958.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9044 signatures=668706 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1810130000 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Darrick J. Wong Plumb in a remap flag that enables the filesystem remap handler to shorten remapping requests for callers that can handle it. Now copy_file_range can report partial success (in case we run up against alignment problems, resource limits, etc.). We also enable CAN_SHORTEN for fideduperange to maintain existing userspace-visible behavior where xfs/btrfs shorten the dedupe range to avoid stale post-eof data exposure. Signed-off-by: Darrick J. Wong Reviewed-by: Amir Goldstein --- fs/read_write.c | 22 +++++++++++++++------- include/linux/fs.h | 7 +++++-- mm/filemap.c | 16 ++++++++++++---- 3 files changed, 32 insertions(+), 13 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index c02fc5144d15..86a8c2557d18 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1593,7 +1593,8 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, cloned = file_in->f_op->remap_file_range(file_in, pos_in, file_out, pos_out, - min_t(loff_t, MAX_RW_COUNT, len), 0); + min_t(loff_t, MAX_RW_COUNT, len), + RFR_CAN_SHORTEN); if (cloned > 0) { ret = cloned; goto done; @@ -1797,6 +1798,8 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, /* Are we doing a partial EOF block remapping of some kind? */ if (*len & blkmask) { + loff_t new_len = *len; + /* * If the dedupe data matches, chop off the partial EOF block * from the source file so we don't try to dedupe the partial @@ -1804,11 +1807,16 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, * * If the user is attempting to remap a partial EOF block and * it's inside the destination EOF then reject it. + * + * If possible, shorten the request instead of rejecting it. */ - if (is_dedupe) - *len &= ~blkmask; - else if (pos_out + *len < i_size_read(inode_out)) - return -EINVAL; + if (is_dedupe || pos_out + *len < i_size_read(inode_out)) + new_len &= ~blkmask; + + if (new_len != *len && !(remap_flags & RFR_CAN_SHORTEN)) + return is_dedupe ? -EBADE : -EINVAL; + + *len = new_len; } return 1; @@ -2006,7 +2014,7 @@ loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos, { loff_t ret; - WARN_ON_ONCE(remap_flags & ~(RFR_SAME_DATA)); + WARN_ON_ONCE(remap_flags & ~(RFR_SAME_DATA | RFR_CAN_SHORTEN)); ret = mnt_want_write_file(dst_file); if (ret) @@ -2107,7 +2115,7 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same) deduped = vfs_dedupe_file_range_one(file, off, dst_file, info->dest_offset, len, - 0); + RFR_CAN_SHORTEN); if (deduped == -EBADE) info->status = FILE_DEDUPE_RANGE_DIFFERS; else if (deduped < 0) diff --git a/include/linux/fs.h b/include/linux/fs.h index b9c314f9d5a4..57cb56bbc30a 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1726,14 +1726,17 @@ struct block_device_operations; * * RFR_SAME_DATA: only remap if contents identical (i.e. deduplicate) * RFR_TO_SRC_EOF: remap to the end of the source file + * RFR_CAN_SHORTEN: caller can handle a shortened request */ #define RFR_SAME_DATA (1 << 0) #define RFR_TO_SRC_EOF (1 << 1) +#define RFR_CAN_SHORTEN (1 << 2) -#define RFR_VALID_FLAGS (RFR_SAME_DATA | RFR_TO_SRC_EOF) +#define RFR_VALID_FLAGS (RFR_SAME_DATA | RFR_TO_SRC_EOF | \ + RFR_CAN_SHORTEN) /* Implemented by the VFS, so these are advisory. */ -#define RFR_VFS_FLAGS (RFR_TO_SRC_EOF) +#define RFR_VFS_FLAGS (RFR_TO_SRC_EOF | RFR_CAN_SHORTEN) /* * Filesystem remapping implementations should call this helper on their diff --git a/mm/filemap.c b/mm/filemap.c index 369cfd164e90..bccbd3621238 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3051,8 +3051,12 @@ int generic_remap_checks(struct file *file_in, loff_t pos_in, if (pos_in + count == size_in) { bcount = ALIGN(size_in, bs) - pos_in; } else { - if (!IS_ALIGNED(count, bs)) - return -EINVAL; + if (!IS_ALIGNED(count, bs)) { + if (remap_flags & RFR_CAN_SHORTEN) + count = ALIGN_DOWN(count, bs); + else + return -EINVAL; + } bcount = count; } @@ -3063,10 +3067,14 @@ int generic_remap_checks(struct file *file_in, loff_t pos_in, pos_out < pos_in + bcount) return -EINVAL; - /* For now we don't support changing the length. */ - if (*req_count != count) + /* + * We shortened the request but the caller can't deal with that, so + * bounce the request back to userspace. + */ + if (*req_count != count && !(remap_flags & RFR_CAN_SHORTEN)) return -EINVAL; + *req_count = count; return 0; }