Do not send SMB3 SET_INFO request if nothing is changing

[CIFS] We had cases where we sent a SMB2/SMB3 setinfo request with all
timestamp (and DOS attribute) fields marked as 0 (ie do not change)
e.g. on chmod or chown.

Signed-off-by: Steve French <steve.french@primarydata.com>
CC: Stable <stable@vger.kernel.org>

diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c
index 4f0231e685a922efcb97a6c5905bfedc7ca7ece6..1238cd3552f9cc8e8f8fc560117af37cd224aa13 100644 (file)
--- a/fs/cifs/smb2inode.c
+++ b/fs/cifs/smb2inode.c
@@ -266,9 +266,15 @@ smb2_set_file_info(struct inode *inode, const char *full_path,
        struct tcon_link *tlink;
        int rc;
 
+       if ((buf->CreationTime == 0) && (buf->LastAccessTime == 0) &&
+           (buf->LastWriteTime == 0) && (buf->ChangeTime) &&
+           (buf->Attributes == 0))
+               return 0; /* would be a no op, no sense sending this */
+
        tlink = cifs_sb_tlink(cifs_sb);
        if (IS_ERR(tlink))
                return PTR_ERR(tlink);
+
        rc = smb2_open_op_close(xid, tlink_tcon(tlink), cifs_sb, full_path,
                                FILE_WRITE_ATTRIBUTES, FILE_OPEN, 0, buf,
                                SMB2_OP_SET_INFO);