cifs: Fix SMB1 readv/writev callback in the same way as SMB2/3

Port a number of SMB2/3 async readv/writev fixes to the SMB1 transport:

    commit a88d609
    cifs: Don't advance the I/O iterator before terminating subrequest

    commit ce5291e
    cifs: Defer read completion

    commit 1da29f2
    netfs, cifs: Fix handling of short DIO read

Fixes: 3ee1a1f ("cifs: Cut over to using netfslib")
Signed-off-by: David Howells <dhowells@redhat.com>
Reported-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/smb/client/cifssmb.c

@@ -1261,16 +1261,32 @@ CIFS_open(const unsigned int xid, struct cifs_open_parms *oparms, int *oplock,
 	return rc;
 }
 
+static void cifs_readv_worker(struct work_struct *work)
+{
+	struct cifs_io_subrequest *rdata =
+		container_of(work, struct cifs_io_subrequest, subreq.work);
+
+	netfs_subreq_terminated(&rdata->subreq,
+				(rdata->result == 0 || rdata->result == -EAGAIN) ?
+				rdata->got_bytes : rdata->result, true);
+}
+
 static void
 cifs_readv_callback(struct mid_q_entry *mid)
 {
 	struct cifs_io_subrequest *rdata = mid->callback_data;
+	struct netfs_inode *ictx = netfs_inode(rdata->rreq->inode);
 	struct cifs_tcon *tcon = tlink_tcon(rdata->req->cfile->tlink);
 	struct TCP_Server_Info *server = tcon->ses->server;
 	struct smb_rqst rqst = { .rq_iov = rdata->iov,
 				 .rq_nvec = 2,
 				 .rq_iter = rdata->subreq.io_iter };
-	struct cifs_credits credits = { .value = 1, .instance = 0 };
+	struct cifs_credits credits = {
+		.value = 1,
+		.instance = 0,
+		.rreq_debug_id = rdata->rreq->debug_id,
+		.rreq_debug_index = rdata->subreq.debug_index,
+	};
 
 	cifs_dbg(FYI, "%s: mid=%llu state=%d result=%d bytes=%zu\n",
 		 __func__, mid->mid, mid->mid_state, rdata->result,
@@ -1282,6 +1298,7 @@ cifs_readv_callback(struct mid_q_entry *mid)
 		if (server->sign) {
 			int rc = 0;
 
+			iov_iter_truncate(&rqst.rq_iter, rdata->got_bytes);
 			rc = cifs_verify_signature(&rqst, server,
 						  mid->sequence_number);
 			if (rc)
@@ -1306,13 +1323,21 @@ cifs_readv_callback(struct mid_q_entry *mid)
 		rdata->result = -EIO;
 	}
 
-	if (rdata->result == 0 || rdata->result == -EAGAIN)
-		iov_iter_advance(&rdata->subreq.io_iter, rdata->got_bytes);
+	if (rdata->result == -ENODATA) {
+		__set_bit(NETFS_SREQ_HIT_EOF, &rdata->subreq.flags);
+		rdata->result = 0;
+	} else {
+		if (rdata->got_bytes < rdata->actual_len &&
+		    rdata->subreq.start + rdata->subreq.transferred + rdata->got_bytes ==
+		    ictx->remote_i_size) {
+			__set_bit(NETFS_SREQ_HIT_EOF, &rdata->subreq.flags);
+			rdata->result = 0;
+		}
+	}
+
 	rdata->credits.value = 0;
-	netfs_subreq_terminated(&rdata->subreq,
-				(rdata->result == 0 || rdata->result == -EAGAIN) ?
-				rdata->got_bytes : rdata->result,
-				false);
+	INIT_WORK(&rdata->subreq.work, cifs_readv_worker);
+	queue_work(cifsiod_wq, &rdata->subreq.work);
 	release_mid(mid);
 	add_credits(server, &credits, 0);
 }
@@ -1619,9 +1644,15 @@ static void
 cifs_writev_callback(struct mid_q_entry *mid)
 {
 	struct cifs_io_subrequest *wdata = mid->callback_data;
+	struct TCP_Server_Info *server = wdata->server;
 	struct cifs_tcon *tcon = tlink_tcon(wdata->req->cfile->tlink);
 	WRITE_RSP *smb = (WRITE_RSP *)mid->resp_buf;
-	struct cifs_credits credits = { .value = 1, .instance = 0 };
+	struct cifs_credits credits = {
+		.value = 1,
+		.instance = 0,
+		.rreq_debug_id = wdata->rreq->debug_id,
+		.rreq_debug_index = wdata->subreq.debug_index,
+	};
 	ssize_t result;
 	size_t written;
 
@@ -1657,9 +1688,16 @@ cifs_writev_callback(struct mid_q_entry *mid)
 		break;
 	}
 
+	trace_smb3_rw_credits(credits.rreq_debug_id, credits.rreq_debug_index,
+			      wdata->credits.value,
+			      server->credits, server->in_flight,
+			      0, cifs_trace_rw_credits_write_response_clear);
 	wdata->credits.value = 0;
 	cifs_write_subrequest_terminated(wdata, result, true);
 	release_mid(mid);
+	trace_smb3_rw_credits(credits.rreq_debug_id, credits.rreq_debug_index, 0,
+			      server->credits, server->in_flight,
+			      credits.value, cifs_trace_rw_credits_write_response_add);
 	add_credits(tcon->ses->server, &credits, 0);
 }