From patchwork Sun Oct 21 16:16:55 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: 10651143 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 6399B181E for ; Sun, 21 Oct 2018 16:17:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5538A287C0 for ; Sun, 21 Oct 2018 16:17:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 49B5A287C2; Sun, 21 Oct 2018 16:17:08 +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 BFEA9287C9 for ; Sun, 21 Oct 2018 16:17:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728062AbeJVAby (ORCPT ); Sun, 21 Oct 2018 20:31:54 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:42358 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727408AbeJVAby (ORCPT ); Sun, 21 Oct 2018 20:31:54 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w9LGE276154815; Sun, 21 Oct 2018 16:17:00 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=Tr6EshQsxOzbBBn5mCvIhaKvT953YPy/0dHgMvFh9q4=; b=Q98qxZ3neieJv3J3cs2XPbWOvcXhLJKXeNpgZCBxOx22q770V7OVZ54D45h6X2ZPDwbz WgvZ/30zQurCheMHXr8w0EfyLjtO/oAl/9ZfcVPzus+aMn2H4qvI3vJXbjW+4nbTAC1v QqXgW0E6Fo4sMTzDZZ4UvvNpVMBm7bBcHGmAzap9WAnUaQO+STEEVvcfXD+vXrmzMKAS aq0GSTpRm7tLbYqIH2kGU+cbSRdZdzX26jvtWFMTGJzo7FEFMP5JkwIZh4C1vOwXtGyX yveqz7oQ/QE6j08TtBLTffc/ZnlSENeaL9xS06Llth1zq5u7HsxfhsxbOTPcziAaf6Ck Sw== Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by aserp2120.oracle.com with ESMTP id 2n7vapjyrk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 21 Oct 2018 16:17:00 +0000 Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id w9LGGwYJ005994 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 21 Oct 2018 16:16:58 GMT Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id w9LGGvO0021301; Sun, 21 Oct 2018 16:16:57 GMT Received: from localhost (/10.159.225.70) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Sun, 21 Oct 2018 09:16:57 -0700 Subject: [PATCH 16/28] 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: Sun, 21 Oct 2018 09:16:55 -0700 Message-ID: <154013861584.29026.5158930020192209258.stgit@magnolia> In-Reply-To: <154013850285.29026.16168387526580596209.stgit@magnolia> References: <154013850285.29026.16168387526580596209.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9053 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=759 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1810210151 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@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 --- Documentation/filesystems/vfs.txt | 4 +++- fs/read_write.c | 28 ++++++++++++++++++++-------- include/linux/fs.h | 5 +++-- mm/filemap.c | 11 +++++++---- 4 files changed, 33 insertions(+), 15 deletions(-) diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 1bd2919deaca..5f71a252e2e0 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -970,7 +970,9 @@ otherwise noted. negative error code if errors occurred before any bytes were remapped. The remap_flags parameter accepts REMAP_FILE_* flags. If REMAP_FILE_DEDUP is set then the implementation must only remap if the - requested file ranges have identical contents. + requested file ranges have identical contents. If REMAP_CAN_SHORTEN is + set, the caller is ok with the implementation shortening the request + length to satisfy alignment or EOF requirements (or any other reason). fadvise: possibly called by the fadvise64() system call. diff --git a/fs/read_write.c b/fs/read_write.c index ea30666013b0..c0bcc1a20650 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), + REMAP_FILE_CAN_SHORTEN); if (cloned > 0) { ret = cloned; goto done; @@ -1721,6 +1722,8 @@ static int remap_verify_area(struct file *file, loff_t pos, loff_t len, * can't meaningfully compare post-EOF contents. * * For clone we only link a partial EOF block above the destination file's EOF. + * + * Shorten the request if possible. */ static int generic_remap_check_len(struct inode *inode_in, struct inode *inode_out, @@ -1729,16 +1732,24 @@ static int generic_remap_check_len(struct inode *inode_in, unsigned int remap_flags) { u64 blkmask = i_blocksize(inode_in) - 1; + loff_t new_len = *len; if ((*len & blkmask) == 0) return 0; - if (remap_flags & REMAP_FILE_DEDUP) - *len &= ~blkmask; - else if (pos_out + *len < i_size_read(inode_out)) - return -EINVAL; + if ((remap_flags & REMAP_FILE_DEDUP) || + pos_out + *len < i_size_read(inode_out)) + new_len &= ~blkmask; - return 0; + if (new_len == *len) + return 0; + + if (remap_flags & REMAP_FILE_CAN_SHORTEN) { + *len = new_len; + return 0; + } + + return (remap_flags & REMAP_FILE_DEDUP) ? -EBADE : -EINVAL; } /* @@ -2014,7 +2025,8 @@ loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos, { loff_t ret; - WARN_ON_ONCE(remap_flags & ~(REMAP_FILE_DEDUP)); + WARN_ON_ONCE(remap_flags & ~(REMAP_FILE_DEDUP | + REMAP_FILE_CAN_SHORTEN)); ret = mnt_want_write_file(dst_file); if (ret) @@ -2115,7 +2127,7 @@ 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); + REMAP_FILE_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 544ab5083b48..34c22d695011 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1727,8 +1727,10 @@ struct block_device_operations; * See Documentation/filesystems/vfs.txt for more details about this call. * * REMAP_FILE_DEDUP: only remap if contents identical (i.e. deduplicate) + * REMAP_FILE_CAN_SHORTEN: caller can handle a shortened request */ #define REMAP_FILE_DEDUP (1 << 0) +#define REMAP_FILE_CAN_SHORTEN (1 << 1) /* * These flags signal that the caller is ok with altering various aspects of @@ -1736,9 +1738,8 @@ struct block_device_operations; * implementation; the vfs remap helper functions can take advantage of them. * Flags in this category exist to preserve the quirky behavior of the hoisted * btrfs clone/dedupe ioctls. - * There are no flags yet, but subsequent commits will add some. */ -#define REMAP_FILE_ADVISORY (0) +#define REMAP_FILE_ADVISORY (REMAP_FILE_CAN_SHORTEN) struct iov_iter; diff --git a/mm/filemap.c b/mm/filemap.c index e9091d731f84..1775d4ad3317 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3045,8 +3045,7 @@ int generic_remap_checks(struct file *file_in, loff_t pos_in, bcount = ALIGN(size_in, bs) - pos_in; } else { if (!IS_ALIGNED(count, bs)) - return -EINVAL; - + count = ALIGN_DOWN(count, bs); bcount = count; } @@ -3056,10 +3055,14 @@ 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 & REMAP_FILE_CAN_SHORTEN)) return -EINVAL; + *req_count = count; return 0; }