From patchwork Fri Dec 30 22:13:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 13084987 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1683FC3DA7D for ; Fri, 30 Dec 2022 23:55:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235833AbiL3XzX (ORCPT ); Fri, 30 Dec 2022 18:55:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51244 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235658AbiL3XzW (ORCPT ); Fri, 30 Dec 2022 18:55:22 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 862311E3CE; Fri, 30 Dec 2022 15:55:21 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 25A0161BCD; Fri, 30 Dec 2022 23:55:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8CBB4C433D2; Fri, 30 Dec 2022 23:55:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1672444520; bh=d6rZADnnl5NJT9em+5xNA+xpoVTObaMoEUZNgr89LGQ=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=OyeO3MbXs7HqmRNt64bgvPOCHTTl9cWxM4RDDFHnhM7JBEnwMtLZOjOVr65jR+sq2 FqBfjAgdtQhRWiffjdtRAMpx7Wipyaxq5SqN+gxvDPjWm6rinQwNZ42SWOhLY8Vuxb cySLaqYR2waqYbJAL+98HBJzvvDTSBlLsvl7433PXCin8iNjhmEiDthCtEXp//LBJJ HAimJzjaR9jCzg32gjM1/XGILNe02EpzPcY/f7bKBK9mPSxFh4qWsWfZR/BRHWvrGZ 4vSbHXvHwTHjBdK7E2RiO5yQvao2x1G1HI+YwVebEMUnDVmq6PXsbT0oDzQ3MZTVDe Q/pDf275PfCEA== Subject: [PATCH 20/21] xfs: support non-power-of-two rtextsize with exchange-range From: "Darrick J. Wong" To: djwong@kernel.org Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org Date: Fri, 30 Dec 2022 14:13:58 -0800 Message-ID: <167243843816.699466.13150984573684791764.stgit@magnolia> In-Reply-To: <167243843494.699466.5163281976943635014.stgit@magnolia> References: <167243843494.699466.5163281976943635014.stgit@magnolia> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Darrick J. Wong The VFS exchange-range alignment checks use (fast) bitmasks to perform block alignment checks on the exchange parameters. Unfortunately, bitmasks require that the alignment size be a power of two. This isn't true for realtime devices, so we have to copy-pasta the VFS checks using long division for this to work properly. Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_xchgrange.c | 102 +++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 91 insertions(+), 11 deletions(-) diff --git a/fs/xfs/xfs_xchgrange.c b/fs/xfs/xfs_xchgrange.c index 6a66d09099b0..ae030a6f607e 100644 --- a/fs/xfs/xfs_xchgrange.c +++ b/fs/xfs/xfs_xchgrange.c @@ -416,6 +416,86 @@ xfs_xchg_range_need_rt_conversion( return xfs_inode_has_bigrtextents(ip); } +/* + * Check the alignment of an exchange request when the allocation unit size + * isn't a power of two. The VFS helpers use (fast) bitmask-based alignment + * checks, but here we have to use slow long division. + */ +static int +xfs_xchg_range_check_rtalign( + struct xfs_inode *ip1, + struct xfs_inode *ip2, + const struct file_xchg_range *fxr) +{ + struct xfs_mount *mp = ip1->i_mount; + uint32_t rextbytes; + uint64_t length = fxr->length; + uint64_t blen; + loff_t size1, size2; + + rextbytes = XFS_FSB_TO_B(mp, mp->m_sb.sb_rextsize); + size1 = i_size_read(VFS_I(ip1)); + size2 = i_size_read(VFS_I(ip2)); + + /* The start of both ranges must be aligned to a rt extent. */ + if (!isaligned_64(fxr->file1_offset, rextbytes) || + !isaligned_64(fxr->file2_offset, rextbytes)) + return -EINVAL; + + /* + * If the caller asked for full files, check that the offset/length + * values cover all of both files. + */ + if ((fxr->flags & FILE_XCHG_RANGE_FULL_FILES) && + (fxr->file1_offset != 0 || fxr->file2_offset != 0 || + fxr->length != size1 || fxr->length != size2)) + return -EDOM; + + if (fxr->flags & FILE_XCHG_RANGE_TO_EOF) + length = max_t(int64_t, size1 - fxr->file1_offset, + size2 - fxr->file2_offset); + + /* + * If the user wanted us to exchange up to the infile's EOF, round up + * to the next rt extent boundary for this check. Do the same for the + * outfile. + * + * Otherwise, reject the range length if it's not rt extent aligned. + * We already confirmed the starting offsets' rt extent block + * alignment. + */ + if (fxr->file1_offset + length == size1) + blen = roundup_64(size1, rextbytes) - fxr->file1_offset; + else if (fxr->file2_offset + length == size2) + blen = roundup_64(size2, rextbytes) - fxr->file2_offset; + else if (!isaligned_64(length, rextbytes)) + return -EINVAL; + else + blen = length; + + /* Don't allow overlapped exchanges within the same file. */ + if (ip1 == ip2 && + fxr->file2_offset + blen > fxr->file1_offset && + fxr->file1_offset + blen > fxr->file2_offset) + return -EINVAL; + + /* + * Ensure that we don't exchange a partial EOF rt extent into the + * middle of another file. + */ + if (isaligned_64(length, rextbytes)) + return 0; + + blen = length; + if (fxr->file2_offset + length < size2) + blen = rounddown_64(blen, rextbytes); + + if (fxr->file1_offset + blen < size1) + blen = rounddown_64(blen, rextbytes); + + return blen == length ? 0 : -EINVAL; +} + /* Prepare two files to have their data exchanged. */ int xfs_xchg_range_prep( @@ -426,6 +506,7 @@ xfs_xchg_range_prep( { struct xfs_inode *ip1 = XFS_I(file_inode(file1)); struct xfs_inode *ip2 = XFS_I(file_inode(file2)); + unsigned int alloc_unit = xfs_inode_alloc_unitsize(ip2); int error; trace_xfs_xchg_range_prep(ip1, fxr, ip2, 0); @@ -434,18 +515,17 @@ xfs_xchg_range_prep( if (XFS_IS_REALTIME_INODE(ip1) != XFS_IS_REALTIME_INODE(ip2)) return -EINVAL; - /* - * The alignment checks in the VFS helpers cannot deal with allocation - * units that are not powers of 2. This can happen with the realtime - * volume if the extent size is set. Note that alignment checks are - * skipped if FULL_FILES is set. - */ - if (!(fxr->flags & FILE_XCHG_RANGE_FULL_FILES) && - !is_power_of_2(xfs_inode_alloc_unitsize(ip2))) - return -EOPNOTSUPP; + /* Check non-power of two alignment issues, if necessary. */ + if (XFS_IS_REALTIME_INODE(ip2) && !is_power_of_2(alloc_unit)) { + error = xfs_xchg_range_check_rtalign(ip1, ip2, fxr); + if (error) + return error; - error = generic_xchg_file_range_prep(file1, file2, fxr, - xfs_inode_alloc_unitsize(ip2)); + /* Do the VFS checks with the regular block alignment. */ + alloc_unit = ip1->i_mount->m_sb.sb_blocksize; + } + + error = generic_xchg_file_range_prep(file1, file2, fxr, alloc_unit); if (error || fxr->length == 0) return error;