[04/26] vfs: exit early from zero length remap operations

Message ID	153965942391.1256.1491987046439132016.stgit@magnolia (mailing list archive)
State	New, archived
Headers	show Return-Path: <owner-linux-mm@kvack.org> Received-SPF: pass (google.com: domain of darrick.wong@oracle.com designates 141.146.126.78 as permitted sender) client-ip=141.146.126.78; Subject: [PATCH 04/26] vfs: exit early from zero length remap operations From: "Darrick J. Wong" <darrick.wong@oracle.com> To: david@fromorbit.com, darrick.wong@oracle.com Cc: sandeen@redhat.com, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, 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: Mon, 15 Oct 2018 20:10:23 -0700 Message-ID: <153965942391.1256.1491987046439132016.stgit@magnolia> In-Reply-To: <153965939489.1256.7400115244528045860.stgit@magnolia> References: <153965939489.1256.7400115244528045860.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Precedence: bulk
Series	fs: fixes for serious clone/dedupe problems \| expand [v5,00/26] fs: fixes for serious clone/dedupe problems [01/26] xfs: add a per-xfs trace_printk macro [02/26] vfs: vfs_clone_file_prep_inodes should return EINVAL for a clone from beyond EOF [03/26] vfs: check file ranges before cloning files [04/26] vfs: exit early from zero length remap operations [05/26] vfs: strengthen checking of file range inputs to generic_remap_checks [06/26] vfs: avoid problematic remapping requests into partial EOF block [07/26] vfs: skip zero-length dedupe requests [08/26] vfs: rename vfs_clone_file_prep to be more descriptive [09/26] vfs: rename clone_verify_area to remap_verify_area [10/26] vfs: combine the clone and dedupe into a single remap_file_range [11/26] vfs: pass remap flags to generic_remap_file_range_prep [12/26] vfs: pass remap flags to generic_remap_checks [13/26] vfs: create generic_remap_file_range_touch to update inode metadata [14/26] vfs: make remap_file_range functions take and return bytes completed [15/26] vfs: plumb remap flags through the vfs clone functions [16/26] vfs: plumb remap flags through the vfs dedupe functions [17/26] vfs: enable remap callers that can handle short operations [18/26] vfs: hide file range comparison function [19/26] vfs: clean up generic_remap_file_range_prep return value [20/26] ocfs2: truncate page cache for clone destination file before remapping [21/26] ocfs2: fix pagecache truncation prior to reflink [22/26] ocfs2: support partial clone range and dedupe range [23/26] ocfs2: remove ocfs2_reflink_remap_range [24/26] xfs: fix pagecache truncation prior to reflink [25/26] xfs: support returning partial reflink results [26/26] xfs: remove redundant remap partial EOF block checks

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Received-SPF: pass (google.com: domain of darrick.wong@oracle.com designates
 141.146.126.78 as permitted sender) client-ip=141.146.126.78;
Subject: [PATCH 04/26] vfs: exit early from zero length remap operations
From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: david@fromorbit.com, darrick.wong@oracle.com
Cc: sandeen@redhat.com, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org,
        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: Mon, 15 Oct 2018 20:10:23 -0700
Message-ID: <153965942391.1256.1491987046439132016.stgit@magnolia>
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Series

fs: fixes for serious clone/dedupe problems | expand

Commit Message

Darrick J. Wong Oct. 16, 2018, 3:10 a.m. UTC

From: Darrick J. Wong <darrick.wong@oracle.com>

If a remap caller asks us to remap to the source file's EOF and the
source file has zero bytes, exit early.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/read_write.c |    2 ++
 1 file changed, 2 insertions(+)

Comments

Christoph Hellwig Oct. 17, 2018, 8:26 a.m. UTC | #1

On Mon, Oct 15, 2018 at 08:10:23PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> If a remap caller asks us to remap to the source file's EOF and the
> source file has zero bytes, exit early.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/fs/read_write.c b/fs/read_write.c
index d6e8e242a15f..2456da3f8a41 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1748,6 +1748,8 @@  int vfs_clone_file_prep(struct file *file_in, loff_t pos_in,
 		if (pos_in > isize)
 			return -EINVAL;
 		*len = isize - pos_in;
+		if (*len == 0)
+			return 0;
 	}
 
 	/* Check that we don't violate system file offset limits. */

[04/26] vfs: exit early from zero length remap operations

Commit Message

Comments

Patch