[CIFS] CIFS writepage improvements - eliminate double copy

Signed-off-by: Steve French (sfrench@us.ibm.com)

1 files changed, 173 insertions, 50 deletions

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 0046c219833d..04f4af07fdd4 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -49,7 +49,8 @@ AllocMidQEntry(struct smb_hdr *smb_buffer, struct cifsSesInfo *ses)
                 return NULL;
         }
         
-        temp = (struct mid_q_entry *) mempool_alloc(cifs_mid_poolp,SLAB_KERNEL | SLAB_NOFS);
+        temp = (struct mid_q_entry *) mempool_alloc(cifs_mid_poolp,
+                                                    SLAB_KERNEL | SLAB_NOFS);
         if (temp == NULL)
                 return temp;
         else {
@@ -179,27 +180,24 @@ smb_send(struct socket *ssocket, struct smb_hdr *smb_buffer,
         return rc;
 }
 
-#ifdef CIFS_EXPERIMENTAL
-/* BB finish off this function, adding support for writing set of pages as iovec */
-/* and also adding support for operations that need to parse the response smb    */
-
-int
-smb_sendv(struct socket *ssocket, struct smb_hdr *smb_buffer,
-         unsigned int smb_buf_length, struct kvec * write_vector 
-          /* page list */, struct sockaddr *sin)
+#ifdef CONFIG_CIFS_EXPERIMENTAL
+static int
+smb_send2(struct socket *ssocket, struct smb_hdr *smb_buffer,
+         unsigned int smb_hdr_length, const char * data, unsigned int datalen,
+         struct sockaddr *sin)
 {
         int rc = 0;
         int i = 0;
         struct msghdr smb_msg;
-        number_of_pages += 1; /* account for SMB header */
-        struct kvec * piov  = kmalloc(number_of_pages * sizeof(struct kvec));
-        unsigned len = smb_buf_length + 4;
-
+        struct kvec iov[2];
+        unsigned len = smb_hdr_length + 4;
+        
         if(ssocket == NULL)
                 return -ENOTSOCK; /* BB eventually add reconnect code here */
-        iov.iov_base = smb_buffer;
-        iov.iov_len = len;
-
+        iov[0].iov_base = smb_buffer;
+        iov[0].iov_len = len;
+        iov[1].iov_base = data;
+        iov[2].iov_len = datalen;
         smb_msg.msg_name = sin;
         smb_msg.msg_namelen = sizeof (struct sockaddr);
         smb_msg.msg_control = NULL;
@@ -212,12 +210,11 @@ smb_sendv(struct socket *ssocket, struct smb_hdr *smb_buffer,
            Flags2 is converted in SendReceive */
 
         smb_buffer->smb_buf_length = cpu_to_be32(smb_buffer->smb_buf_length);
-        cFYI(1, ("Sending smb of length %d ", smb_buf_length));
+        cFYI(1, ("Sending smb of length %d ", len + datalen));
         dump_smb(smb_buffer, len);
 
-        while (len > 0) {
-                rc = kernel_sendmsg(ssocket, &smb_msg, &iov, number_of_pages, 
-                                    len);
+        while (len + datalen > 0) {
+                rc = kernel_sendmsg(ssocket, &smb_msg, iov, 2, len);
                 if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
                         i++;
                         if(i > 60) {
@@ -232,9 +229,22 @@ smb_sendv(struct socket *ssocket, struct smb_hdr *smb_buffer,
                 }
                 if (rc < 0) 
                         break;
-                iov.iov_base += rc;
-                iov.iov_len -= rc;
-                len -= rc;
+                if(iov[0].iov_len > 0) {
+                        if(rc >= len) {
+                                iov[0].iov_len = 0;
+                                rc -= len;
+                        } else {  /* some of hdr was not sent */
+                                len -= rc;
+                                iov[0].iov_len -= rc;
+                                iov[0].iov_base += rc;
+                                continue;
+                        }
+                }
+                if((iov[0].iov_len == 0) && (rc > 0)){
+                        iov[1].iov_base += rc;
+                        iov[1].iov_len -= rc;
+                        datalen -= rc;
+                }
         }
 
         if (rc < 0) {
@@ -246,14 +256,15 @@ smb_sendv(struct socket *ssocket, struct smb_hdr *smb_buffer,
         return rc;
 }
 
-
 int
-CIFSSendRcv(const unsigned int xid, struct cifsSesInfo *ses,
-            struct smb_hdr *in_buf, struct kvec * write_vector /* page list */, int *pbytes_returned, const int long_op)
+SendReceive2(const unsigned int xid, struct cifsSesInfo *ses, 
+             struct smb_hdr *in_buf, int hdrlen, const char * data,
+             int datalen, int *pbytes_returned, const int long_op)
 {
         int rc = 0;
-        unsigned long timeout = 15 * HZ;
-        struct mid_q_entry *midQ = NULL;
+        unsigned int receive_len;
+        unsigned long timeout;
+        struct mid_q_entry *midQ;
 
         if (ses == NULL) {
                 cERROR(1,("Null smb session"));
@@ -263,14 +274,8 @@ CIFSSendRcv(const unsigned int xid, struct cifsSesInfo *ses,
                 cERROR(1,("Null tcp session"));
                 return -EIO;
         }
-        if(pbytes_returned == NULL)
-                return -EIO;
-        else
-                *pbytes_returned = 0;
 
-  
-
-        if(ses->server->tcpStatus == CIFS_EXITING)
+        if(ses->server->tcpStatus == CifsExiting)
                 return -ENOENT;
 
         /* Ensure that we do not send more than 50 overlapping requests 
@@ -282,7 +287,8 @@ CIFSSendRcv(const unsigned int xid, struct cifsSesInfo *ses,
         } else {
                 spin_lock(&GlobalMid_Lock); 
                 while(1) {        
-                        if(atomic_read(&ses->server->inFlight) >= cifs_max_pending){
+                        if(atomic_read(&ses->server->inFlight) >= 
+                                        cifs_max_pending){
                                 spin_unlock(&GlobalMid_Lock);
                                 wait_event(ses->server->request_q,
                                         atomic_read(&ses->server->inFlight)
@@ -314,17 +320,17 @@ CIFSSendRcv(const unsigned int xid, struct cifsSesInfo *ses,
 
         if (ses->server->tcpStatus == CifsExiting) {
                 rc = -ENOENT;
-                goto cifs_out_label;
+                goto out_unlock2;
         } else if (ses->server->tcpStatus == CifsNeedReconnect) {
                 cFYI(1,("tcp session dead - return to caller to retry"));
                 rc = -EAGAIN;
-                goto cifs_out_label;
+                goto out_unlock2;
         } else if (ses->status != CifsGood) {
                 /* check if SMB session is bad because we are setting it up */
                 if((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) && 
                         (in_buf->Command != SMB_COM_NEGOTIATE)) {
                         rc = -EAGAIN;
-                        goto cifs_out_label;
+                        goto out_unlock2;
                 } /* else ok - we are setting up session */
         }
         midQ = AllocMidQEntry(in_buf, ses);
@@ -352,13 +358,12 @@ CIFSSendRcv(const unsigned int xid, struct cifsSesInfo *ses,
                 return -EIO;
         }
 
-        /* BB can we sign efficiently in this path? */
-        rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
+/* BB FIXME */
+/*      rc = cifs_sign_smb2(in_buf, data, ses->server, &midQ->sequence_number); */
 
         midQ->midState = MID_REQUEST_SUBMITTED;
-/*      rc = smb_sendv(ses->server->ssocket, in_buf, in_buf->smb_buf_length,
-                       piovec, 
-                       (struct sockaddr *) &(ses->server->addr.sockAddr));*/
+        rc = smb_send2(ses->server->ssocket, in_buf, hdrlen, data, datalen,
+                      (struct sockaddr *) &(ses->server->addr.sockAddr));
         if(rc < 0) {
                 DeleteMidQEntry(midQ);
                 up(&ses->server->tcpSem);
@@ -370,19 +375,137 @@ CIFSSendRcv(const unsigned int xid, struct cifsSesInfo *ses,
                 return rc;
         } else
                 up(&ses->server->tcpSem);
-cifs_out_label:
-        if(midQ)
-                DeleteMidQEntry(midQ);
-                                                                                                                           
+        if (long_op == -1)
+                goto cifs_no_response_exit2;
+        else if (long_op == 2) /* writes past end of file can take loong time */
+                timeout = 300 * HZ;
+        else if (long_op == 1)
+                timeout = 45 * HZ; /* should be greater than 
+                        servers oplock break timeout (about 43 seconds) */
+        else if (long_op > 2) {
+                timeout = MAX_SCHEDULE_TIMEOUT;
+        } else
+                timeout = 15 * HZ;
+        /* wait for 15 seconds or until woken up due to response arriving or 
+           due to last connection to this server being unmounted */
+        if (signal_pending(current)) {
+                /* if signal pending do not hold up user for full smb timeout
+                but we still give response a change to complete */
+                timeout = 2 * HZ;
+        }   
+
+        /* No user interrupts in wait - wreaks havoc with performance */
+        if(timeout != MAX_SCHEDULE_TIMEOUT) {
+                timeout += jiffies;
+                wait_event(ses->server->response_q,
+                        (!(midQ->midState & MID_REQUEST_SUBMITTED)) || 
+                        time_after(jiffies, timeout) || 
+                        ((ses->server->tcpStatus != CifsGood) &&
+                         (ses->server->tcpStatus != CifsNew)));
+        } else {
+                wait_event(ses->server->response_q,
+                        (!(midQ->midState & MID_REQUEST_SUBMITTED)) || 
+                        ((ses->server->tcpStatus != CifsGood) &&
+                         (ses->server->tcpStatus != CifsNew)));
+        }
+
+        spin_lock(&GlobalMid_Lock);
+        if (midQ->resp_buf) {
+                spin_unlock(&GlobalMid_Lock);
+                receive_len = be32_to_cpu(*(__be32 *)midQ->resp_buf);
+        } else {
+                cERROR(1,("No response buffer"));
+                if(midQ->midState == MID_REQUEST_SUBMITTED) {
+                        if(ses->server->tcpStatus == CifsExiting)
+                                rc = -EHOSTDOWN;
+                        else {
+                                ses->server->tcpStatus = CifsNeedReconnect;
+                                midQ->midState = MID_RETRY_NEEDED;
+                        }
+                }
+
+                if (rc != -EHOSTDOWN) {
+                        if(midQ->midState == MID_RETRY_NEEDED) {
+                                rc = -EAGAIN;
+                                cFYI(1,("marking request for retry"));
+                        } else {
+                                rc = -EIO;
+                        }
+                }
+                spin_unlock(&GlobalMid_Lock);
+                DeleteMidQEntry(midQ);
+                /* If not lock req, update # of requests on wire to server */
+                if(long_op < 3) {
+                        atomic_dec(&ses->server->inFlight); 
+                        wake_up(&ses->server->request_q);
+                }
+                return rc;
+        }
+  
+        if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
+                cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
+                        receive_len, xid));
+                rc = -EIO;
+        } else {                /* rcvd frame is ok */
+
+                if (midQ->resp_buf && 
+                        (midQ->midState == MID_RESPONSE_RECEIVED)) {
+                        in_buf->smb_buf_length = receive_len;
+                        /* BB verify that length would not overrun small buf */
+                        memcpy((char *)in_buf + 4,
+                               (char *)midQ->resp_buf + 4,
+                               receive_len);
+
+                        dump_smb(in_buf, 80);
+                        /* convert the length into a more usable form */
+                        if((receive_len > 24) &&
+                           (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
+                                        SECMODE_SIGN_ENABLED))) {
+                                rc = cifs_verify_signature(in_buf,
+                                                ses->server->mac_signing_key,
+                                                midQ->sequence_number+1);
+                                if(rc) {
+                                        cERROR(1,("Unexpected SMB signature"));
+                                        /* BB FIXME add code to kill session */
+                                }
+                        }
+
+                        *pbytes_returned = in_buf->smb_buf_length;
+
+                        /* BB special case reconnect tid and uid here? */
+                        rc = map_smb_to_linux_error(in_buf);
+
+                        /* convert ByteCount if necessary */
+                        if (receive_len >=
+                            sizeof (struct smb_hdr) -
+                            4 /* do not count RFC1001 header */  +
+                            (2 * in_buf->WordCount) + 2 /* bcc */ )
+                                BCC(in_buf) = le16_to_cpu(BCC(in_buf));
+                } else {
+                        rc = -EIO;
+                        cFYI(1,("Bad MID state? "));
+                }
+        }
+cifs_no_response_exit2:
+        DeleteMidQEntry(midQ);
+
         if(long_op < 3) {
-                atomic_dec(&ses->server->inFlight);
+                atomic_dec(&ses->server->inFlight); 
                 wake_up(&ses->server->request_q);
         }
 
         return rc;
-}
 
+out_unlock2:
+        up(&ses->server->tcpSem);
+        /* If not lock req, update # of requests on wire to server */
+        if(long_op < 3) {
+                atomic_dec(&ses->server->inFlight); 
+                wake_up(&ses->server->request_q);
+        }
 
+        return rc;
+}
 #endif /* CIFS_EXPERIMENTAL */
 
 int