FAILED: patch "[PATCH] cifs/smb3: Fix data inconsistent when zero file range" failed to apply to 4.19-stable tree

FAILED: patch "[PATCH] cifs/smb3: Fix data inconsistent when zero file range" failed to apply to 4.19-stable tree

[gregkh]

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 6b69040247e14b43419a520f841f2b3052833df9 Mon Sep 17 00:00:00 2001
From: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Date: Tue, 23 Jun 2020 07:31:54 -0400
Subject: [PATCH] cifs/smb3: Fix data inconsistent when zero file range

CIFS implements the fallocate(FALLOC_FL_ZERO_RANGE) with send SMB
ioctl(FSCTL_SET_ZERO_DATA) to server. It just set the range of the
remote file to zero, but local page cache not update, then the data
inconsistent with server, which leads the xfstest generic/008 failed.

So we need to remove the local page caches before send SMB
ioctl(FSCTL_SET_ZERO_DATA) to server. After next read, it will
re-cache it.

Fixes: 30175628bf7f5 ("[SMB3] Enable fallocate -z support for SMB3 mounts")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Cc: stable@vger.kernel.org # v3.17
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 28553d45604e..876a0d9e3d46 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3188,6 +3188,11 @@ static long smb3_zero_range(struct file *file, struct cifs_tcon *tcon,
 	trace_smb3_zero_enter(xid, cfile->fid.persistent_fid, tcon->tid,
 			      ses->Suid, offset, len);
 
+	/*
+	 * We zero the range through ioctl, so we need remove the page caches
+	 * first, otherwise the data may be inconsistent with the server.
+	 */
+	truncate_pagecache_range(inode, offset, offset + len - 1);
 
 	/* if file not oplocked can't be sure whether asking to extend size */
 	if (!CIFS_CACHE_READ(cifsi))

Re: FAILED: patch "[PATCH] cifs/smb3: Fix data inconsistent when zero file range" failed to apply to 4.19-stable tree

[Sasha Levin]

On Sun, Jun 28, 2020 at 05:50:40PM +0200, gregkh@linuxfoundation.org wrote:
>
>The patch below does not apply to the 4.19-stable tree.
>If someone wants it applied there, or to any other stable or longterm
>tree, then please email the backport, including the original git commit
>id to <stable@vger.kernel.org>.
>
>thanks,
>
>greg k-h
>
>------------------ original commit in Linus's tree ------------------
>
>From 6b69040247e14b43419a520f841f2b3052833df9 Mon Sep 17 00:00:00 2001
>From: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
>Date: Tue, 23 Jun 2020 07:31:54 -0400
>Subject: [PATCH] cifs/smb3: Fix data inconsistent when zero file range
>
>CIFS implements the fallocate(FALLOC_FL_ZERO_RANGE) with send SMB
>ioctl(FSCTL_SET_ZERO_DATA) to server. It just set the range of the
>remote file to zero, but local page cache not update, then the data
>inconsistent with server, which leads the xfstest generic/008 failed.
>
>So we need to remove the local page caches before send SMB
>ioctl(FSCTL_SET_ZERO_DATA) to server. After next read, it will
>re-cache it.
>
>Fixes: 30175628bf7f5 ("[SMB3] Enable fallocate -z support for SMB3 mounts")
>Reported-by: Hulk Robot <hulkci@huawei.com>
>Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
>Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
>Cc: stable@vger.kernel.org # v3.17
>Signed-off-by: Steve French <stfrench@microsoft.com>

Conflict with the tracepoint that didn't exist on older kernels. Fixed
up and queued for 4.19, 4.14, 4.9, and 4.4.

-- 
Thanks,
Sasha