The patch below does not apply to the 4.9-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@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 6b69040247e14b43419a520f841f2b3052833df9 Mon Sep 17 00:00:00 2001
From: Zhang Xiaoxu <zhangxiaoxu5@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@xxxxxxxxxx>
Reviewed-by: Pavel Shilovsky <pshilov@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v3.17
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
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))
