[PATCH] cifs: Ease memory pressure, do not use large buffers in byte range lock requests.

Signed-off-by: Steve French (sfrench@us.ibm.com)
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/cifs/cifssmb.c

@@ -1023,11 +1023,13 @@ CIFSSMBLock(const int xid, struct cifsTconInfo *tcon,
 	__u16 count;
 
 	cFYI(1, ("In CIFSSMBLock - timeout %d numLock %d",waitFlag,numLock));
-	rc = smb_init(SMB_COM_LOCKING_ANDX, 8, tcon, (void **) &pSMB,
-		      (void **) &pSMBr);
+	rc = small_smb_init(SMB_COM_LOCKING_ANDX, 8, tcon, (void **) &pSMB);
+
 	if (rc)
 		return rc;
 
+	pSMBr = (LOCK_RSP *)pSMB; /* BB removeme BB */
+
 	if(lockType == LOCKING_ANDX_OPLOCK_RELEASE) {
 		timeout = -1; /* no response expected */
 		pSMB->Timeout = 0;
@@ -1065,7 +1067,7 @@ CIFSSMBLock(const int xid, struct cifsTconInfo *tcon,
 	if (rc) {
 		cFYI(1, ("Send error in Lock = %d", rc));
 	}
-	cifs_buf_release(pSMB);
+	cifs_small_buf_release(pSMB);
 
 	/* Note: On -EAGAIN error only caller can retry on handle based calls 
 	since file handle passed in no longer valid */

fs/cifs/connect.c

@@ -294,21 +294,27 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
 			csocket = server->ssocket;
 			wake_up(&server->response_q);
 			continue;
-		} else if (length > 3) {
+		} else if (length < 4) {
+			cFYI(1,
+			    ("Frame less than four bytes received  %d bytes long.",
+			      length));
+			cifs_reconnect(server);
+			csocket = server->ssocket;
+			wake_up(&server->response_q);
+			continue;
+		}
+
+		/* the right amount was read from socket - 4 bytes */
+
 		pdu_length = ntohl(smb_buffer->smb_buf_length);
-		/* Only read pdu_length after below checks for too short (due
-		   to e.g. int overflow) and too long ie beyond end of buf */
-			cFYI(1,("rfc1002 length(big endian)0x%x)",
-				pdu_length+4));
+		cFYI(1,("rfc1002 length(big endian)0x%x)", pdu_length+4));
 
 		temp = (char *) smb_buffer;
 		if (temp[0] == (char) RFC1002_SESSION_KEEP_ALIVE) {
 			cFYI(0,("Received 4 byte keep alive packet"));
-			} else if (temp[0] == 
-				(char) RFC1002_POSITIVE_SESSION_RESPONSE) {
+		} else if (temp[0] == (char)RFC1002_POSITIVE_SESSION_RESPONSE) {
 				cFYI(1,("Good RFC 1002 session rsp"));
-			} else if (temp[0] == 
-				(char)RFC1002_NEGATIVE_SESSION_RESPONSE) {
+		} else if (temp[0] == (char)RFC1002_NEGATIVE_SESSION_RESPONSE) {
 			/* we get this from Windows 98 instead of 
 			   an error on SMB negprot response */
 			cFYI(1,("Negative RFC 1002 Session Response Error 0x%x)",temp[4]));
@@ -339,7 +345,7 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
 			cifs_reconnect(server);
 			csocket = server->ssocket;
 			continue;
-			} else {
+		} else { /* we have an SMB response */
 			if((pdu_length > CIFSMaxBufSize + 
 				MAX_CIFS_HDR_SIZE - 4) ||
 			    (pdu_length < sizeof (struct smb_hdr) - 1 - 4)) {
@@ -351,6 +357,8 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
 				wake_up(&server->response_q);
 				continue;
 			} else { /* length ok */
+				int reconnect = 0;
+
 				if(pdu_length > MAX_CIFS_HDR_SIZE - 4) {
 					isLargeBuf = TRUE;
 					memcpy(bigbuf, smallbuf, 4);
@@ -368,14 +376,16 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
 					if((server->tcpStatus == CifsExiting) ||
 					    (length == -EINTR)) {
 						/* then will exit */
-							goto dmx_loop_end;
+						reconnect = 2;
+						break;
 					} else if (server->tcpStatus ==
 						    CifsNeedReconnect) {
 						cifs_reconnect(server);
 						csocket = server->ssocket;
 					        /* Reconnect wakes up rspns q */
 						/* Now we will reread sock */
-							goto dmx_loop_end;
+						reconnect = 1;
+						break;
 					} else if ((length == -ERESTARTSYS) || 
 						   (length == -EAGAIN)) {
 						msleep(1); /* minimum sleep to prevent looping
@@ -383,14 +393,19 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
                                                               tcpStatus CifsNeedReconnect if server hung */
 						continue;
 					} else if (length <= 0) {
-							cERROR(1,
-							       ("Received no data, expecting %d",
+						cERROR(1,("Received no data, expecting %d",
 						      pdu_length - total_read));
 						cifs_reconnect(server);
 						csocket = server->ssocket;
-							goto dmx_loop_end;
+						reconnect = 1;
+						break;
 					}
 				}
+				if(reconnect == 2)
+				    break;
+				else if(reconnect == 1)
+				    continue;
+
 				length += 4; /* account for rfc1002 hdr */
 			}
 
@@ -401,13 +416,11 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
 				continue;
 			}
 
-				/* BB FIXME - add checkTrans2SMBSecondary() */
 
 			task_to_wake = NULL;
 			spin_lock(&GlobalMid_Lock);
 			list_for_each(tmp, &server->pending_mid_q) {
-					mid_entry = list_entry(tmp, struct
-							       mid_q_entry,
+				mid_entry = list_entry(tmp, struct mid_q_entry,
 							qhead);
 
 				if ((mid_entry->mid == smb_buffer->Mid)
@@ -417,6 +430,8 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
 						smb_buffer->Command)) {
 					cFYI(1,("Found Mid 0x%x wake up"
 						,mid_entry->mid));
+					/* BB FIXME - missing code here BB */
+					/* check_2nd_t2(smb_buffer); */
 					task_to_wake = mid_entry->tsk;
 					mid_entry->resp_buf =
 					    smb_buffer;
@@ -441,18 +456,6 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
 				cifs_dump_mem("Received Data is: ",temp,sizeof(struct smb_hdr));
 			}
 		}
-		} else {
-			cFYI(1,
-			    ("Frame less than four bytes received  %d bytes long.",
-			      length));
-			cifs_reconnect(server);
-			csocket = server->ssocket;
-			wake_up(&server->response_q);
-			continue;
-		}
-dmx_loop_end:
-		cFYI(1,("Exiting cifsd loop"));
-
 	}
 	spin_lock(&GlobalMid_Lock);
 	server->tcpStatus = CifsExiting;