From acc91c2d8de4ef46ed751c5f9df99ed9a109b100 Mon Sep 17 00:00:00 2001 From: Zhang Xiaoxu Date: Tue, 23 Jun 2020 07:31:53 -0400 Subject: cifs/smb3: Fix data inconsistent when punch hole 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 Reviewed-by: Pavel Shilovsky Signed-off-by: Zhang Xiaoxu Cc: stable@vger.kernel.org # v3.17 Signed-off-by: Steve French --- fs/cifs/smb2ops.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'fs') diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 876a0d9e3d46..d9fdafa5eb60 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -3259,6 +3259,12 @@ static long smb3_punch_hole(struct file *file, struct cifs_tcon *tcon, 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); -- cgit v1.2.3