This is a note to let you know that I've just added the patch titled
cifs/smb3: Fix data inconsistent when punch hole
to the 5.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cifs-smb3-fix-data-inconsistent-when-punch-hole.patch
and it can be found in the queue-5.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From acc91c2d8de4ef46ed751c5f9df99ed9a109b100 Mon Sep 17 00:00:00 2001
From: Zhang Xiaoxu <zhangxiaoxu5@xxxxxxxxxx>
Date: Tue, 23 Jun 2020 07:31:53 -0400
Subject: cifs/smb3: Fix data inconsistent when punch hole
From: Zhang Xiaoxu <zhangxiaoxu5@xxxxxxxxxx>
commit acc91c2d8de4ef46ed751c5f9df99ed9a109b100 upstream.
When punch hole success, we also can read old data from file:
# strace -e trace=pread64,fallocate xfs_io -f -c "pread 20 40" \
-c "fpunch 20 40" -c"pread 20 40" file
pread64(3, " version 5.8.0-rc1+"..., 40, 20) = 40
fallocate(3, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 20, 40) = 0
pread64(3, " version 5.8.0-rc1+"..., 40, 20) = 40
CIFS implements the fallocate(FALLOCATE_FL_PUNCH_HOLE) with send SMB
ioctl(FSCTL_SET_ZERO_DATA) to server. It just set the range of the
remote file to zero, but local page caches not updated, then the
local page caches inconsistent with server.
Also can be found by xfstests generic/316.
So, we need to remove the page caches before send the SMB
ioctl(FSCTL_SET_ZERO_DATA) to server.
Fixes: 31742c5a33176 ("enable fallocate punch hole ("fallocate -p") for SMB3")
Suggested-by: Pavel Shilovsky <pshilov@xxxxxxxxxxxxx>
Reviewed-by: Pavel Shilovsky <pshilov@xxxxxxxxxxxxx>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v3.17
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/cifs/smb2ops.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3211,6 +3211,12 @@ static long smb3_punch_hole(struct file
return rc;
}
+ /*
+ * We implement the punch hole 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);
+
cifs_dbg(FYI, "Offset %lld len %lld\n", offset, len);
fsctl_buf.FileOffset = cpu_to_le64(offset);
Patches currently in stable-queue which might be from zhangxiaoxu5@xxxxxxxxxx are
queue-5.7/cifs-smb3-fix-data-inconsistent-when-zero-file-range.patch
queue-5.7/cifs-smb3-fix-data-inconsistent-when-punch-hole.patch
