From patchwork Thu Oct 11 16:05:28 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: 10636959 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 4B0D9157A for ; Thu, 11 Oct 2018 16:06:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3AA852BA9B for ; Thu, 11 Oct 2018 16:06:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 38AA22BAED; Thu, 11 Oct 2018 16:06:11 +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=-5.3 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from userp2120.oracle.com (userp2120.oracle.com [156.151.31.85]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id B7D7C2BAC9 for ; Thu, 11 Oct 2018 16:06:10 +0000 (UTC) Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w9BFwejE061078; Thu, 11 Oct 2018 16:05:56 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : message-id : references : mime-version : in-reply-to : cc : subject : list-id : list-unsubscribe : list-archive : list-post : list-help : list-subscribe : content-type : content-transfer-encoding : sender; s=corp-2018-07-02; bh=ZpHDpd0A0p3lWatw9Rk5PzK/4PUYCibdZX2OahgSx60=; b=ZEaRWXPGfg8lyvkGbwufGmj+Bei5j+7G0Rc9RStdLwhppK06HlQ5sMEjIgWl28BAZNGX UWR7v5E8GL2LXOuTdsLRm9EIRVmNRc7b5NRBogjb58byNElxDnNTGoeaXBivO2dAaVoH VXRBjCF9d8pCXT+EoWv+sVE4gM+viOPNfkwADKQSVvmIQ2zuZJy5RaUyhlUo0Mik0Km8 iu3DP18QL9jHXP6Pyb74VAi3dxjOKHfgn+tqYg0D9I78Exjlfbe4EhxH7LOxkuSVWQTe qQ8tspYYshTFtagQzweAuKG2OubXiV/KI0WyDldmmNFoG1PEp9m7H19iF4YJqQyXdGvv Ew== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp2120.oracle.com with ESMTP id 2mxnprd946-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 11 Oct 2018 16:05:56 +0000 Received: from oss.oracle.com (oss-old-reserved.oracle.com [137.254.22.2]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w9BG5sf4010531 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 11 Oct 2018 16:05:55 GMT Received: from localhost ([127.0.0.1] helo=lb-oss.oracle.com) by oss.oracle.com with esmtp (Exim 4.63) (envelope-from ) id 1gAdTG-0000zl-FK; Thu, 11 Oct 2018 09:05:54 -0700 Received: from userv0022.oracle.com ([156.151.31.74]) by oss.oracle.com with esmtp (Exim 4.63) (envelope-from ) id 1gAdSt-0000yj-8q for ocfs2-devel@oss.oracle.com; Thu, 11 Oct 2018 09:05:31 -0700 Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id w9BG5UQ3020141 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 11 Oct 2018 16:05:31 GMT Received: from abhmp0003.oracle.com (abhmp0003.oracle.com [141.146.116.9]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w9BG5UrQ016472; Thu, 11 Oct 2018 16:05:30 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 11 Oct 2018 16:05:29 +0000 Date: Thu, 11 Oct 2018 09:05:28 -0700 From: "Darrick J. Wong" To: david@fromorbit.com Message-ID: <20181011160528.GB28243@magnolia> References: <153923113649.5546.9840926895953408273.stgit@magnolia> <153923126628.5546.3484461137192547927.stgit@magnolia> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <153923126628.5546.3484461137192547927.stgit@magnolia> User-Agent: Mutt/1.9.4 (2018-02-28) 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, ocfs2-devel@oss.oracle.com, linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org Subject: [Ocfs2-devel] [PATCH v2 17/25] vfs: enable remap callers that can handle short operations X-BeenThere: ocfs2-devel@oss.oracle.com X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: ocfs2-devel-bounces@oss.oracle.com Errors-To: ocfs2-devel-bounces@oss.oracle.com X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9042 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-1810110154 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 --- v2: fix missing WARN_ON_ONCE and update changelog --- fs/read_write.c | 17 ++++++++++------- include/linux/fs.h | 7 +++++-- mm/filemap.c | 16 ++++++++++++---- 3 files changed, 27 insertions(+), 13 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index 6ec908f9a69b..9d33f0a14720 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; @@ -1804,16 +1805,18 @@ 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. * - * We don't support shortening requests, so we can only reject - * them. + * If possible, shorten the request instead of rejecting it. */ if (is_dedupe) ret = -EBADE; else if (pos_out + *len < i_size_read(inode_out)) ret = -EINVAL; - if (ret) - return ret; + if (ret) { + if (!(remap_flags & RFR_CAN_SHORTEN)) + return ret; + *len &= ~blkmask; + } } return 1; @@ -2011,7 +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) @@ -2112,7 +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; }