[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>

1 files changed, 149 insertions, 146 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 8c5d310514ea..419f145c80b5 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -294,165 +294,168 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
                         csocket = server->ssocket;
                         wake_up(&server->response_q);
                         continue;
-                } else if (length > 3) {
-                        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));
-
-                        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) {
-                                        cFYI(1,("Good RFC 1002 session rsp"));
-                        } 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]));
-                                if(server->tcpStatus == CifsNew) {
-                                        /* if nack on negprot (rather than 
-                                        ret of smb negprot error) reconnecting
-                                        not going to help, ret error to mount */
-                                        break;
-                                } else {
-                                        /* give server a second to
-                                        clean up before reconnect attempt */
-                                        msleep(1000);
-                                        /* always try 445 first on reconnect
-                                        since we get NACK on some if we ever
-                                        connected to port 139 (the NACK is 
-                                        since we do not begin with RFC1001
-                                        session initialize frame) */
-                                        server->addr.sockAddr.sin_port = 
-                                                htons(CIFS_PORT);
-                                        cifs_reconnect(server);
-                                        csocket = server->ssocket;
-                                        wake_up(&server->response_q);
-                                        continue;
-                                }
-                        } else if (temp[0] != (char) 0) {
-                                cERROR(1,("Unknown RFC 1002 frame"));
-                                cifs_dump_mem(" Received Data: ", temp, length);
+                } 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);
+                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) {
+                                cFYI(1,("Good RFC 1002 session rsp"));
+                } 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]));
+                        if(server->tcpStatus == CifsNew) {
+                                /* if nack on negprot (rather than 
+                                ret of smb negprot error) reconnecting
+                                not going to help, ret error to mount */
+                                break;
+                        } else {
+                                /* give server a second to
+                                clean up before reconnect attempt */
+                                msleep(1000);
+                                /* always try 445 first on reconnect
+                                since we get NACK on some if we ever
+                                connected to port 139 (the NACK is 
+                                since we do not begin with RFC1001
+                                session initialize frame) */
+                                server->addr.sockAddr.sin_port = 
+                                        htons(CIFS_PORT);
                                 cifs_reconnect(server);
                                 csocket = server->ssocket;
+                                wake_up(&server->response_q);
                                 continue;
-                        } else {
-                                if((pdu_length > CIFSMaxBufSize + 
-                                        MAX_CIFS_HDR_SIZE - 4) ||
-                                    (pdu_length < sizeof (struct smb_hdr) - 1 - 4)) {
-                                        cERROR(1,
-                                            ("Invalid size SMB length %d and pdu_length %d",
-                                                length, pdu_length+4));
-                                        cifs_reconnect(server);
-                                        csocket = server->ssocket;
-                                        wake_up(&server->response_q);
-                                        continue;
-                                } else { /* length ok */
-                                        if(pdu_length > MAX_CIFS_HDR_SIZE - 4) {
-                                                isLargeBuf = TRUE;
-                                                memcpy(bigbuf, smallbuf, 4);
-                                                smb_buffer = bigbuf;
-                                        }
-                                        length = 0;
-                                        iov.iov_base = 4 + (char *)smb_buffer;
-                                        iov.iov_len = pdu_length;
-                                        for (total_read = 0;
-                                             total_read < pdu_length;
-                                             total_read += length) {
-                                                length = kernel_recvmsg(csocket, &smb_msg,
-                                                        &iov, 1,
-                                                        pdu_length - total_read, 0);
-                                                if((server->tcpStatus == CifsExiting) ||
-                                                    (length == -EINTR)) {
-                                                        /* then will exit */
-                                                        goto dmx_loop_end;
-                                                } else if (server->tcpStatus ==
-                                                            CifsNeedReconnect) {
-                                                        cifs_reconnect(server);
-                                                        csocket = server->ssocket;
-                                                /* Reconnect wakes up rspns q */
+                        }
+                } else if (temp[0] != (char) 0) {
+                        cERROR(1,("Unknown RFC 1002 frame"));
+                        cifs_dump_mem(" Received Data: ", temp, length);
+                        cifs_reconnect(server);
+                        csocket = server->ssocket;
+                        continue;
+                } else { /* we have an SMB response */
+                        if((pdu_length > CIFSMaxBufSize + 
+                                MAX_CIFS_HDR_SIZE - 4) ||
+                            (pdu_length < sizeof (struct smb_hdr) - 1 - 4)) {
+                                cERROR(1,
+                                    ("Invalid size SMB length %d and pdu_length %d",
+                                        length, pdu_length+4));
+                                cifs_reconnect(server);
+                                csocket = server->ssocket;
+                                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);
+                                        smb_buffer = bigbuf;
+                                }
+                                length = 0;
+                                iov.iov_base = 4 + (char *)smb_buffer;
+                                iov.iov_len = pdu_length;
+                                for (total_read = 0;
+                                     total_read < pdu_length;
+                                     total_read += length) {
+                                        length = kernel_recvmsg(csocket, &smb_msg,
+                                                &iov, 1,
+                                                pdu_length - total_read, 0);
+                                        if((server->tcpStatus == CifsExiting) ||
+                                            (length == -EINTR)) {
+                                                /* then will exit */
+                                                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;
-                                                } else if ((length == -ERESTARTSYS) || 
-                                                           (length == -EAGAIN)) {
-                                                        msleep(1); /* minimum sleep to prevent looping
-                                                                allowing socket to clear and app threads to set
-                                                                tcpStatus CifsNeedReconnect if server hung */
-                                                        continue;
-                                                } else if (length <= 0) {
-                                                        cERROR(1,
-                                                               ("Received no data, expecting %d",
-                                                                pdu_length - total_read));
-                                                        cifs_reconnect(server);
-                                                        csocket = server->ssocket;
-                                                        goto dmx_loop_end;
-                                                }
+                                                reconnect = 1;
+                                                break;
+                                        } else if ((length == -ERESTARTSYS) || 
+                                                   (length == -EAGAIN)) {
+                                                msleep(1); /* minimum sleep to prevent looping
+                                                              allowing socket to clear and app threads to set
+                                                              tcpStatus CifsNeedReconnect if server hung */
+                                                continue;
+                                        } else if (length <= 0) {
+                                                cERROR(1,("Received no data, expecting %d",
+                                                      pdu_length - total_read));
+                                                cifs_reconnect(server);
+                                                csocket = server->ssocket;
+                                                reconnect = 1;
+                                                break;
                                         }
-                                        length += 4; /* account for rfc1002 hdr */
                                 }
+                                if(reconnect == 2)
+                                    break;
+                                else if(reconnect == 1)
+                                    continue;
 
-                                dump_smb(smb_buffer, length);
-                                if (checkSMB
-                                    (smb_buffer, smb_buffer->Mid, total_read+4)) {
-                                        cERROR(1, ("Bad SMB Received "));
-                                        continue;
-                                }
+                                length += 4; /* account for rfc1002 hdr */
+                        }
 
-                                /* 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,
-                                                               qhead);
-
-                                        if ((mid_entry->mid == smb_buffer->Mid)
-                                                && (mid_entry->midState == 
-                                                        MID_REQUEST_SUBMITTED) 
-                                                && (mid_entry->command == 
-                                                        smb_buffer->Command)) {
-                                                cFYI(1,("Found Mid 0x%x wake up"
-                                                        ,mid_entry->mid));
-                                                task_to_wake = mid_entry->tsk;
-                                                mid_entry->resp_buf =
-                                                    smb_buffer;
-                                                mid_entry->midState =
-                                                    MID_RESPONSE_RECEIVED;
-                                                if(isLargeBuf)
-                                                        mid_entry->largeBuf = 1;
-                                                else
-                                                        mid_entry->largeBuf = 0;
-                                        }
-                                }
-                                spin_unlock(&GlobalMid_Lock);
-                                if (task_to_wake) {
+                        dump_smb(smb_buffer, length);
+                        if (checkSMB
+                            (smb_buffer, smb_buffer->Mid, total_read+4)) {
+                                cERROR(1, ("Bad SMB Received "));
+                                continue;
+                        }
+
+
+                        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,
+                                                        qhead);
+
+                                if ((mid_entry->mid == smb_buffer->Mid)
+                                        && (mid_entry->midState == 
+                                                MID_REQUEST_SUBMITTED) 
+                                        && (mid_entry->command == 
+                                                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;
+                                        mid_entry->midState =
+                                            MID_RESPONSE_RECEIVED;
                                         if(isLargeBuf)
-                                                bigbuf = NULL;
+                                                mid_entry->largeBuf = 1;
                                         else
-                                                smallbuf = NULL;
-                                        smb_buffer = NULL; /* will be freed by users thread after he is done */
-                                        wake_up_process(task_to_wake);
-                                } else if (is_valid_oplock_break(smb_buffer) == FALSE) {                          
-                                        cERROR(1, ("No task to wake, unknown frame rcvd!"));
-                                        cifs_dump_mem("Received Data is: ",temp,sizeof(struct smb_hdr));
+                                                mid_entry->largeBuf = 0;
                                 }
                         }
-                } 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;
+                        spin_unlock(&GlobalMid_Lock);
+                        if (task_to_wake) {
+                                if(isLargeBuf)
+                                        bigbuf = NULL;
+                                else
+                                        smallbuf = NULL;
+                                smb_buffer = NULL; /* will be freed by users thread after he is done */
+                                wake_up_process(task_to_wake);
+                        } else if (is_valid_oplock_break(smb_buffer) == FALSE) {                          
+                                cERROR(1, ("No task to wake, unknown frame rcvd!"));
+                                cifs_dump_mem("Received Data is: ",temp,sizeof(struct smb_hdr));
+                        }
                 }
-dmx_loop_end:
-                cFYI(1,("Exiting cifsd loop"));
-
         }
         spin_lock(&GlobalMid_Lock);
         server->tcpStatus = CifsExiting;