Windows: refactor cm_GetBuffer avoid BIOD construction
[openafs.git] / src / WINNT / afsd / cm_dcache.c
index 2552f57..482cbf4 100644 (file)
@@ -54,6 +54,7 @@ long cm_BufWrite(void *vscp, osi_hyper_t *offsetp, long length, long flags,
     cm_scache_t *scp = vscp;
     afs_int32 nbytes;
     afs_int32 save_nbytes;
+    cm_scache_t save_scache;
     long temp;
     AFSFetchStatus outStatus;
     AFSStoreStatus inStatus;
@@ -152,10 +153,14 @@ long cm_BufWrite(void *vscp, osi_hyper_t *offsetp, long length, long flags,
         require_64bit_ops = 1;
     }
 
+    /* now we're ready to do the store operation */
+  retry_rpc:
+    InterlockedIncrement(&scp->activeRPCs);
     lock_ReleaseWrite(&scp->rw);
 
-    /* now we're ready to do the store operation */
     save_nbytes = nbytes;
+    save_scache = *scp;
+
     do {
         code = cm_ConnFromFID(&scp->fid, userp, reqp, &connp);
         if (code)
@@ -274,7 +279,7 @@ long cm_BufWrite(void *vscp, osi_hyper_t *offsetp, long length, long flags,
                 temp = rx_Writev(rxcallp, tiov, tnio, vbytes);
                 if (temp != vbytes) {
                     osi_Log3(afsd_logp, "rx_Writev failed bp 0x%p, %d != %d", bufp, temp, vbytes);
-                    code = (rxcallp->error < 0) ? rxcallp->error : RX_PROTOCOL_ERROR;
+                    code = (rx_Error(rxcallp) < 0) ? rx_Error(rxcallp) : RX_PROTOCOL_ERROR;
                     break;
                 }
 
@@ -370,7 +375,7 @@ long cm_BufWrite(void *vscp, osi_hyper_t *offsetp, long length, long flags,
             osi_Log2(afsd_logp, "rx_EndCall converted 0x%x to 0x%x", code, code1);
             code = code1;
         }
-    } while (cm_Analyze(connp, userp, reqp, &scp->fid, &volSync, NULL, NULL, code));
+    } while (cm_Analyze(connp, userp, reqp, &scp->fid, 1, &volSync, NULL, NULL, code));
 
     code = cm_MapRPCError(code, reqp);
 
@@ -382,8 +387,6 @@ long cm_BufWrite(void *vscp, osi_hyper_t *offsetp, long length, long flags,
     /* now, clean up our state */
     lock_ObtainWrite(&scp->rw);
 
-    cm_ReleaseBIOD(&biod, 1, code, 1);
-
     if (code == 0) {
         osi_hyper_t t;
         /* now, here's something a little tricky: in AFS 3, a dirty
@@ -417,12 +420,24 @@ long cm_BufWrite(void *vscp, osi_hyper_t *offsetp, long length, long flags,
 
         cm_MergeStatus(NULL, scp, &outStatus, &volSync, userp, reqp, CM_MERGEFLAG_STOREDATA);
     } else {
+        InterlockedDecrement(&scp->activeRPCs);
         if (code == CM_ERROR_SPACE)
             _InterlockedOr(&scp->flags, CM_SCACHEFLAG_OUTOFSPACE);
         else if (code == CM_ERROR_QUOTA)
             _InterlockedOr(&scp->flags, CM_SCACHEFLAG_OVERQUOTA);
     }
 
+    if ( cm_verifyData )
+    {
+        if (!cm_VerifyStoreData(&biod, &save_scache)) {
+            /* file server content doesn't match what we sent. */
+            nbytes = save_nbytes;
+            goto retry_rpc;
+        }
+    }
+
+    cm_ReleaseBIOD(&biod, 1, code, 1);
+
   exit_storedata_excl:
     if (storedata_excl)
         cm_SyncOpDone(scp, NULL, CM_SCACHESYNC_STOREDATA_EXCL);
@@ -478,6 +493,7 @@ long cm_StoreMini(cm_scache_t *scp, cm_user_t *userp, cm_req_t *reqp)
         require_64bit_ops = 1;
     }
 
+    InterlockedIncrement(&scp->activeRPCs);
     lock_ReleaseWrite(&scp->rw);
 
     cm_AFSFidFromFid(&tfid, &scp->fid);
@@ -548,7 +564,7 @@ long cm_StoreMini(cm_scache_t *scp, cm_user_t *userp, cm_req_t *reqp)
         /* prefer StoreData error over rx_EndCall error */
         if (code == 0 && code1 != 0)
             code = code1;
-    } while (cm_Analyze(connp, userp, reqp, &scp->fid, &volSync, NULL, NULL, code));
+    } while (cm_Analyze(connp, userp, reqp, &scp->fid, 1, &volSync, NULL, NULL, code));
     code = cm_MapRPCError(code, reqp);
 
     /* now, clean up our state */
@@ -570,6 +586,8 @@ long cm_StoreMini(cm_scache_t *scp, cm_user_t *userp, cm_req_t *reqp)
         if (LargeIntegerGreaterThanOrEqualTo(t, scp->length))
             _InterlockedAnd(&scp->mask, ~CM_SCACHEMASK_LENGTH);
         cm_MergeStatus(NULL, scp, &outStatus, &volSync, userp, reqp, CM_MERGEFLAG_STOREDATA);
+    } else {
+        InterlockedDecrement(&scp->activeRPCs);
     }
     cm_SyncOpDone(scp, NULL, CM_SCACHESYNC_STOREDATA_EXCL);
 
@@ -1003,6 +1021,8 @@ long cm_SetupStoreBIOD(cm_scache_t *scp, osi_hyper_t *inOffsetp, long inSize,
 
     /* clear things out */
     biop->scp = scp;                   /* do not hold; held by caller */
+    biop->userp = userp;                /* do not hold; held by caller */
+    biop->reqp = reqp;
     biop->offset = *inOffsetp;
     biop->length = 0;
     biop->bufListp = NULL;
@@ -1074,6 +1094,10 @@ long cm_SetupStoreBIOD(cm_scache_t *scp, osi_hyper_t *inOffsetp, long inSize,
     /* put this element in the list */
     qdp = osi_QDAlloc();
     osi_SetQData(qdp, bufp);
+
+    if ( cm_verifyData )
+        buf_ComputeCheckSum(bufp);
+
     /* don't have to hold bufp, since held by buf_Find above */
     osi_QAddH((osi_queue_t **) &biop->bufListp,
               (osi_queue_t **) &biop->bufListEndp,
@@ -1083,16 +1107,15 @@ long cm_SetupStoreBIOD(cm_scache_t *scp, osi_hyper_t *inOffsetp, long inSize,
     biop->offset = firstModOffset;
     bufp = NULL;       /* this buffer and reference added to the queue */
 
-    /* compute the window surrounding *inOffsetp of size cm_chunkSize */
-    scanStart = *inOffsetp;
+    /* compute the window surrounding firstModOffset of size cm_chunkSize */
+    scanStart = firstModOffset;
     scanStart.LowPart &= (-cm_chunkSize);
     thyper = ConvertLongToLargeInteger(cm_chunkSize);
     scanEnd = LargeIntegerAdd(scanStart, thyper);
 
     flags = CM_SCACHESYNC_GETSTATUS
         | CM_SCACHESYNC_STOREDATA
-        | CM_SCACHESYNC_BUFLOCKED
-        | CM_SCACHESYNC_NOWAIT;
+        | CM_SCACHESYNC_BUFLOCKED;
 
     /* start by looking backwards until scanStart */
     /* hyper version of cm_data.buf_blockSize */
@@ -1140,6 +1163,10 @@ long cm_SetupStoreBIOD(cm_scache_t *scp, osi_hyper_t *inOffsetp, long inSize,
          */
         qdp = osi_QDAlloc();
         osi_SetQData(qdp, bufp);
+
+        if ( cm_verifyData )
+            buf_ComputeCheckSum(bufp);
+
         /* no buf_hold necessary, since we have it held from buf_Find */
         osi_QAddT((osi_queue_t **) &biop->bufListp,
                   (osi_queue_t **) &biop->bufListEndp,
@@ -1200,6 +1227,10 @@ long cm_SetupStoreBIOD(cm_scache_t *scp, osi_hyper_t *inOffsetp, long inSize,
          */
         qdp = osi_QDAlloc();
         osi_SetQData(qdp, bufp);
+
+        if ( cm_verifyData )
+            buf_ComputeCheckSum(bufp);
+
         /* no buf_hold necessary, since we have it held from buf_Find */
         osi_QAddH((osi_queue_t **) &biop->bufListp,
                   (osi_queue_t **) &biop->bufListEndp,
@@ -1242,6 +1273,7 @@ long cm_SetupFetchBIOD(cm_scache_t *scp, osi_hyper_t *offsetp,
     tblocksize = ConvertLongToLargeInteger(cm_data.buf_blockSize);
 
     biop->scp = scp;                   /* do not hold; held by caller */
+    biop->userp = userp;                /* do not hold; held by caller */
     biop->reqp = reqp;
     biop->offset = *offsetp;
     /* null out the list of buffers */
@@ -1541,7 +1573,7 @@ void cm_ReleaseBIOD(cm_bulkIO_t *biop, int isStore, long code, int scp_locked)
         if (RDR_Initialized && reportErrorToRedir) {
             DWORD status;
             smb_MapNTError(cm_MapRPCError(code, biop->reqp), &status, TRUE);
-            RDR_SetFileStatus( &scp->fid, status);
+            RDR_SetFileStatus( &scp->fid, &biop->userp->authgroup, status);
         }
     } else {
        if (!scp_locked)
@@ -1669,7 +1701,7 @@ long cm_GetBuffer(cm_scache_t *scp, cm_buf_t *bufp, int *cpffp, cm_user_t *userp
     code = cm_SetupFetchBIOD(scp, &bufp->offset, &biod, userp, reqp);
     if (code) {
         /* couldn't even get the first page setup properly */
-        osi_Log1(afsd_logp, "GetBuffer: SetupFetchBIOD failure code %d", code);
+        osi_Log1(afsd_logp, "cm_GetBuffer: SetupFetchBIOD failure code %d", code);
         return code;
     }
 
@@ -1680,28 +1712,53 @@ long cm_GetBuffer(cm_scache_t *scp, cm_buf_t *bufp, int *cpffp, cm_user_t *userp
      * We can lose a race condition and end up with biod.length zero, in
      * which case we just retry.
      */
-    if (bufp->dataVersion <= scp->dataVersion && bufp->dataVersion >= scp->bufDataVersionLow || biod.length == 0) {
-        if ((bufp->dataVersion == CM_BUF_VERSION_BAD || bufp->dataVersion < scp->bufDataVersionLow) &&
-             LargeIntegerGreaterThanOrEqualTo(bufp->offset, scp->serverLength))
-        {
-            osi_Log4(afsd_logp, "Bad DVs 0x%x != (0x%x -> 0x%x) or length 0x%x",
-                     bufp->dataVersion, scp->bufDataVersionLow, scp->dataVersion, biod.length);
 
-            if (bufp->dataVersion == CM_BUF_VERSION_BAD)
-                memset(bufp->datap, 0, cm_data.buf_blockSize);
-            bufp->dataVersion = scp->dataVersion;
+    if (bufp->dataVersion <= scp->dataVersion && bufp->dataVersion >= scp->bufDataVersionLow) {
+        /* We obtained the buffer while we were waiting */
+        goto release_biod;
+    }
+
+    if (biod.length == 0) {
+        osi_Log2(afsd_logp, "cm_GetBuffer BIOD length 0 scp 0x%p bufp 0x%p",
+                 scp, bufp);
+        code = CM_ERROR_RETRY;
+        goto release_biod;
+    }
+
+    /* Check for buffers we can fill locally */
+    for (qdp = biod.bufListEndp;
+          qdp;
+          qdp = (osi_queueData_t *) osi_QPrev(&qdp->q)) {
+        tbufp = osi_GetQData(qdp);
+
+        if ( tbufp->dataVersion == CM_BUF_VERSION_BAD ||
+             tbufp->dataVersion < scp->bufDataVersionLow ||
+             tbufp->dataVersion > scp->dataVersion) {
+
+            osi_Log4(afsd_logp, "cm_GetBuffer bufp 0x%p DVs 0x%x != (0x%x -> 0x%x)",
+                     tbufp, tbufp->dataVersion, scp->bufDataVersionLow, scp->dataVersion);
+
+            if (LargeIntegerGreaterThanOrEqualTo(tbufp->offset, scp->length))
+            {
+                if (tbufp->dataVersion == CM_BUF_VERSION_BAD)
+                    memset(tbufp->datap, 0, cm_data.buf_blockSize);
+                tbufp->dataVersion = scp->dataVersion;
+            }
+
+            if ((scp->mask & CM_SCACHEMASK_TRUNCPOS) &&
+                 LargeIntegerGreaterThanOrEqualTo(tbufp->offset, scp->truncPos)) {
+                memset(tbufp->datap, 0, cm_data.buf_blockSize);
+                tbufp->dataVersion = scp->dataVersion;
+            }
         }
-        cm_ReleaseBIOD(&biod, 0, 0, 1);
-        return 0;
-    } else if ((bufp->dataVersion == CM_BUF_VERSION_BAD || bufp->dataVersion < scp->bufDataVersionLow)
-                && (scp->mask & CM_SCACHEMASK_TRUNCPOS) &&
-                LargeIntegerGreaterThanOrEqualTo(bufp->offset, scp->truncPos)) {
-        memset(bufp->datap, 0, cm_data.buf_blockSize);
-        bufp->dataVersion = scp->dataVersion;
-        cm_ReleaseBIOD(&biod, 0, 0, 1);
-        return 0;
     }
 
+    if (bufp->dataVersion <= scp->dataVersion && bufp->dataVersion >= scp->bufDataVersionLow) {
+        /* We locally populated the buffer we wanted */
+        goto release_biod;
+    }
+
+    InterlockedIncrement(&scp->activeRPCs);
     lock_ReleaseWrite(&scp->rw);
     scp_locked = 0;
 
@@ -1789,7 +1846,8 @@ long cm_GetBuffer(cm_scache_t *scp, cm_buf_t *bufp, int *cpffp, cm_user_t *userp
      * the network round trip by allocating zeroed buffers and
      * faking the status info.
      */
-    if (biod.offset.QuadPart >= scp->length.QuadPart) {
+    if (biod.offset.QuadPart >= scp->serverLength.QuadPart ||
+        ((scp->mask & CM_SCACHEMASK_TRUNCPOS) && biod.offset.QuadPart > scp->truncPos.QuadPart)) {
         osi_Log5(afsd_logp, "SKIP FetchData64 scp 0x%p, off 0x%x:%08x > length 0x%x:%08x",
                  scp, biod.offset.HighPart, biod.offset.LowPart,
                  scp->length.HighPart, scp->length.LowPart);
@@ -1841,7 +1899,7 @@ long cm_GetBuffer(cm_scache_t *scp, cm_buf_t *bufp, int *cpffp, cm_user_t *userp
                     nbytes_hi = ntohl(nbytes_hi);
                 } else {
                     nbytes_hi = 0;
-                   code = rxcallp->error;
+                   code = rx_Error(rxcallp);
                     code1 = rx_EndCall(rxcallp, code);
                     rxcallp = NULL;
                 }
@@ -1890,7 +1948,7 @@ long cm_GetBuffer(cm_scache_t *scp, cm_buf_t *bufp, int *cpffp, cm_user_t *userp
                 }
             } else {
                 osi_Log1(afsd_logp, "cm_GetBuffer rx_Read32 returns %d != 4", temp);
-                code = (rxcallp->error < 0) ? rxcallp->error : RX_PROTOCOL_ERROR;
+                code = (rx_Error(rxcallp) < 0) ? rx_Error(rxcallp) : RX_PROTOCOL_ERROR;
             }
         }
         /* for the moment, nbytes_hi will always be 0 if code == 0
@@ -1931,7 +1989,7 @@ long cm_GetBuffer(cm_scache_t *scp, cm_buf_t *bufp, int *cpffp, cm_user_t *userp
                     if (fs_fetchdata_offset_bug && first_read)
                         length_found = 0;
                     else
-                        code = (rxcallp->error < 0) ? rxcallp->error : RX_PROTOCOL_ERROR;
+                        code = (rx_Error(rxcallp) < 0) ? rx_Error(rxcallp) : RX_PROTOCOL_ERROR;
                     break;
                 }
 
@@ -1944,7 +2002,7 @@ long cm_GetBuffer(cm_scache_t *scp, cm_buf_t *bufp, int *cpffp, cm_user_t *userp
 
                     osi_assertx(bufferp != NULL, "null cm_buf_t");
 
-                    len = MIN(tiov[iov].iov_len - iov_offset, cm_data.buf_blockSize - buffer_offset);
+                    len = min(tiov[iov].iov_len - iov_offset, cm_data.buf_blockSize - buffer_offset);
                     memcpy(bufferp + buffer_offset, tiov[iov].iov_base + iov_offset, len);
                     iov_offset += len;
                     buffer_offset += len;
@@ -2008,7 +2066,7 @@ long cm_GetBuffer(cm_scache_t *scp, cm_buf_t *bufp, int *cpffp, cm_user_t *userp
                     if (fs_fetchdata_offset_bug && first_read)
                         length_found = 0;
                     else
-                        code = (rxcallp->error < 0) ? rxcallp->error : RX_PROTOCOL_ERROR;
+                        code = (rx_Error(rxcallp) < 0) ? rx_Error(rxcallp) : RX_PROTOCOL_ERROR;
                     break;
                 }
                 first_read = 0;
@@ -2110,7 +2168,7 @@ long cm_GetBuffer(cm_scache_t *scp, cm_buf_t *bufp, int *cpffp, cm_user_t *userp
             code = code1;
         osi_Log0(afsd_logp, "CALL FetchData DONE");
 
-    } while (cm_Analyze(connp, userp, reqp, &scp->fid, &volSync, NULL, NULL, code));
+    } while (cm_Analyze(connp, userp, reqp, &scp->fid, 0, &volSync, NULL, NULL, code));
 
   fetchingcompleted:
     code = cm_MapRPCError(code, reqp);
@@ -2140,11 +2198,14 @@ long cm_GetBuffer(cm_scache_t *scp, cm_buf_t *bufp, int *cpffp, cm_user_t *userp
         }
     }
 
-    /* release scatter/gather I/O structure (buffers, locks) */
-    cm_ReleaseBIOD(&biod, 0, code, 1);
-
     if (code == 0)
         cm_MergeStatus(NULL, scp, &afsStatus, &volSync, userp, reqp, CM_MERGEFLAG_FETCHDATA);
+    else
+        InterlockedDecrement(&scp->activeRPCs);
+
+  release_biod:
+    /* release scatter/gather I/O structure (buffers, locks) */
+    cm_ReleaseBIOD(&biod, 0, code, 1);
 
     return code;
 }
@@ -2206,6 +2267,7 @@ long cm_GetData(cm_scache_t *scp, osi_hyper_t *offsetp, char *datap, int data_le
         require_64bit_ops = 1;
     }
 
+    InterlockedIncrement(&scp->activeRPCs);
     osi_Log2(afsd_logp, "cm_GetData: fetching data scp %p DV 0x%x", scp, scp->dataVersion);
 
 #ifdef AFS_FREELANCE_CLIENT
@@ -2294,7 +2356,7 @@ long cm_GetData(cm_scache_t *scp, osi_hyper_t *offsetp, char *datap, int data_le
                     nbytes_hi = ntohl(nbytes_hi);
                 } else {
                     nbytes_hi = 0;
-                   code = rxcallp->error;
+                   code = rx_Error(rxcallp);
                     code1 = rx_EndCall(rxcallp, code);
                     rxcallp = NULL;
                 }
@@ -2342,7 +2404,7 @@ long cm_GetData(cm_scache_t *scp, osi_hyper_t *offsetp, char *datap, int data_le
                 }
             } else {
                 osi_Log1(afsd_logp, "cm_GetData rx_Read32 returns %d != 4", temp);
-                code = (rxcallp->error < 0) ? rxcallp->error : RX_PROTOCOL_ERROR;
+                code = (rx_Error(rxcallp) < 0) ? rx_Error(rxcallp) : RX_PROTOCOL_ERROR;
             }
         }
         /* for the moment, nbytes_hi will always be 0 if code == 0
@@ -2374,7 +2436,7 @@ long cm_GetData(cm_scache_t *scp, osi_hyper_t *offsetp, char *datap, int data_le
                     if (fs_fetchdata_offset_bug && first_read)
                         length_found = 0;
                     else
-                        code = (rxcallp->error < 0) ? rxcallp->error : RX_PROTOCOL_ERROR;
+                        code = (rx_Error(rxcallp) < 0) ? rx_Error(rxcallp) : RX_PROTOCOL_ERROR;
                     break;
                 }
 
@@ -2387,7 +2449,7 @@ long cm_GetData(cm_scache_t *scp, osi_hyper_t *offsetp, char *datap, int data_le
 
                     osi_assertx(bufferp != NULL, "null cm_buf_t");
 
-                    len = MIN(tiov[iov].iov_len - iov_offset, data_length - buffer_offset);
+                    len = min(tiov[iov].iov_len - iov_offset, data_length - buffer_offset);
                     memcpy(bufferp + buffer_offset, tiov[iov].iov_base + iov_offset, len);
                     iov_offset += len;
                     buffer_offset += len;
@@ -2421,7 +2483,7 @@ long cm_GetData(cm_scache_t *scp, osi_hyper_t *offsetp, char *datap, int data_le
                     if (fs_fetchdata_offset_bug && first_read)
                         length_found = 0;
                     else
-                        code = (rxcallp->error < 0) ? rxcallp->error : RX_PROTOCOL_ERROR;
+                        code = (rx_Error(rxcallp) < 0) ? rx_Error(rxcallp) : RX_PROTOCOL_ERROR;
                     break;
                 }
                 first_read = 0;
@@ -2484,7 +2546,7 @@ long cm_GetData(cm_scache_t *scp, osi_hyper_t *offsetp, char *datap, int data_le
             code = code1;
         osi_Log0(afsd_logp, "CALL FetchData DONE");
 
-    } while (cm_Analyze(connp, userp, reqp, &scp->fid, &volSync, NULL, NULL, code));
+    } while (cm_Analyze(connp, userp, reqp, &scp->fid, 0, &volSync, NULL, NULL, code));
 
   fetchingcompleted:
     code = cm_MapRPCError(code, reqp);
@@ -2494,6 +2556,274 @@ long cm_GetData(cm_scache_t *scp, osi_hyper_t *offsetp, char *datap, int data_le
 
     if (code == 0)
         cm_MergeStatus(NULL, scp, &afsStatus, &volSync, userp, reqp, CM_MERGEFLAG_FETCHDATA);
+    else
+        InterlockedDecrement(&scp->activeRPCs);
 
     return code;
 }
+
+/*
+ * cm_VerifyStoreData.   Function passed a rw locked cm_scache_t and a store data biod.
+ *
+ * Return 1 if the data verifies; 0 if not.
+ */
+
+long
+cm_VerifyStoreData(cm_bulkIO_t *biod, cm_scache_t *savedScp)
+{
+    long code=0, code1=0;
+    afs_uint32 nbytes;                 /* bytes in transfer */
+    afs_uint32 nbytes_hi = 0;           /* high-order 32 bits of bytes in transfer */
+    afs_uint64 length_found = 0;
+    long rbytes;                       /* bytes in rx_Read call */
+    long temp;
+    AFSFetchStatus afsStatus;
+    AFSCallBack callback;
+    AFSVolSync volSync;
+    AFSFid tfid;
+    struct rx_call *rxcallp;
+    struct rx_connection *rxconnp;
+    cm_conn_t *connp;
+    int require_64bit_ops = 0;
+    int call_was_64bit = 0;
+    int fs_fetchdata_offset_bug = 0;
+    int first_read = 1;
+    int scp_locked = 1;
+    char * bufferp = malloc(biod->length);
+    long verified = 0;
+    cm_scache_t *scp = biod->scp;
+    cm_user_t *userp = biod->userp;
+    cm_req_t *reqp = biod->reqp;
+    afs_uint64 dataVersion = scp->dataVersion;
+
+    memset(&volSync, 0, sizeof(volSync));
+    memset(bufferp, 0, biod->length);
+
+    cm_AFSFidFromFid(&tfid, &scp->fid);
+
+    if (LargeIntegerGreaterThan(LargeIntegerAdd(biod->offset,
+                                                ConvertLongToLargeInteger(biod->length)),
+                                ConvertLongToLargeInteger(LONG_MAX))) {
+        require_64bit_ops = 1;
+    }
+
+    InterlockedIncrement(&scp->activeRPCs);
+    osi_Log2(afsd_logp, "cm_VerifyStoreData: fetching data scp %p DV 0x%x", scp, scp->dataVersion);
+
+    if (scp_locked) {
+        lock_ReleaseWrite(&scp->rw);
+        scp_locked = 0;
+    }
+
+    /* now make the call */
+    do {
+        code = cm_ConnFromFID(&scp->fid, userp, reqp, &connp);
+        if (code)
+            continue;
+
+        rxconnp = cm_GetRxConn(connp);
+        rxcallp = rx_NewCall(rxconnp);
+        rx_PutConnection(rxconnp);
+
+        nbytes = nbytes_hi = 0;
+
+        if (SERVERHAS64BIT(connp)) {
+            call_was_64bit = 1;
+
+            osi_Log4(afsd_logp, "CALL FetchData64 scp 0x%p, off 0x%x:%08x, size 0x%x",
+                     scp, biod->offset.HighPart, biod->offset.LowPart, biod->length);
+
+            code = StartRXAFS_FetchData64(rxcallp, &tfid, biod->offset.QuadPart, biod->length);
+
+            if (code == 0) {
+                temp = rx_Read32(rxcallp, &nbytes_hi);
+                if (temp == sizeof(afs_int32)) {
+                    nbytes_hi = ntohl(nbytes_hi);
+                } else {
+                    nbytes_hi = 0;
+                   code = rx_Error(rxcallp);
+                    code1 = rx_EndCall(rxcallp, code);
+                    rxcallp = NULL;
+                }
+            }
+        } else {
+            call_was_64bit = 0;
+        }
+
+        if (code == RXGEN_OPCODE || !SERVERHAS64BIT(connp)) {
+            if (require_64bit_ops) {
+                osi_Log0(afsd_logp, "Skipping FetchData.  Operation requires FetchData64");
+                code = CM_ERROR_TOOBIG;
+            } else {
+                if (!rxcallp) {
+                    rxconnp = cm_GetRxConn(connp);
+                    rxcallp = rx_NewCall(rxconnp);
+                    rx_PutConnection(rxconnp);
+                }
+
+                osi_Log3(afsd_logp, "CALL FetchData scp 0x%p, off 0x%x, size 0x%x",
+                         scp, biod->offset.LowPart, biod->length);
+
+                code = StartRXAFS_FetchData(rxcallp, &tfid, biod->offset.LowPart, biod->length);
+
+                SET_SERVERHASNO64BIT(connp);
+            }
+        }
+
+        if (code == 0) {
+            temp  = rx_Read32(rxcallp, &nbytes);
+            if (temp == sizeof(afs_int32)) {
+                nbytes = ntohl(nbytes);
+                FillInt64(length_found, nbytes_hi, nbytes);
+                if (length_found > biod->length) {
+                    /*
+                     * prior to 1.4.12 and 1.5.65 the file server would return
+                     * (filesize - offset) if the requested offset was greater than
+                     * the filesize.  The correct return value would have been zero.
+                     * Force a retry by returning an RX_PROTOCOL_ERROR.  If the cause
+                     * is a race between two RPCs issues by this cache manager, the
+                     * correct thing will happen the second time.
+                     */
+                    osi_Log0(afsd_logp, "cm_GetData length_found > biod.length");
+                    fs_fetchdata_offset_bug = 1;
+                }
+            } else {
+                osi_Log1(afsd_logp, "cm_GetData rx_Read32 returns %d != 4", temp);
+                code = (rx_Error(rxcallp) < 0) ? rx_Error(rxcallp) : RX_PROTOCOL_ERROR;
+            }
+        }
+        /* for the moment, nbytes_hi will always be 0 if code == 0
+           because data_length is a 32-bit quantity. */
+
+        if (code == 0) {
+            /* fill length_found of data from the pipe into the pages.
+             * When we stop, qdp will point at the last page we're
+             * dealing with, and bufferp will tell us where we
+             * stopped.  We'll need this info below when we clear
+             * the remainder of the last page out (and potentially
+             * clear later pages out, if we fetch past EOF).
+             */
+            while (length_found > 0) {
+                /* assert that there are still more buffers;
+                 * our check above for length_found being less than
+                 * data_length should ensure this.
+                 */
+                osi_assertx(bufferp != NULL, "null cm_buf_t");
+
+                /* read rbytes of data */
+                rbytes = (afs_uint32)(length_found > biod->length ? biod->length : length_found);
+                temp = rx_Read(rxcallp, bufferp, rbytes);
+                if (temp < rbytes) {
+                    /*
+                     * If the file server returned (filesize - offset),
+                     * then the first rx_Read will return zero octets of data.
+                     * If it does, do not treat it as an error.  Correct the
+                     * length_found and continue as if the file server said
+                     * it was sending us zero octets of data.
+                     */
+                    if (fs_fetchdata_offset_bug && first_read)
+                        length_found = 0;
+                    else
+                        code = (rx_Error(rxcallp) < 0) ? rx_Error(rxcallp) : RX_PROTOCOL_ERROR;
+                    break;
+                }
+                first_read = 0;
+
+                /* and adjust counters */
+                length_found -= temp;
+            }
+        }
+
+        if (code == 0) {
+            if (call_was_64bit)
+                code = EndRXAFS_FetchData64(rxcallp, &afsStatus, &callback, &volSync);
+            else
+                code = EndRXAFS_FetchData(rxcallp, &afsStatus, &callback, &volSync);
+        } else {
+            if (call_was_64bit)
+                osi_Log1(afsd_logp, "CALL EndRXAFS_FetchData64 skipped due to error %d", code);
+            else
+                osi_Log1(afsd_logp, "CALL EndRXAFS_FetchData skipped due to error %d", code);
+        }
+
+        if (rxcallp)
+            code1 = rx_EndCall(rxcallp, code);
+
+        if (code1 == RXKADUNKNOWNKEY)
+            osi_Log0(afsd_logp, "CALL EndCall returns RXKADUNKNOWNKEY");
+
+        /* If we are avoiding a file server bug, ignore the error state */
+        if (fs_fetchdata_offset_bug && first_read && length_found == 0 && code == -451) {
+            /* Clone the current status info and clear the error state */
+            scp_locked = cm_CloneStatus(scp, userp, scp_locked, &afsStatus, &volSync);
+            if (scp_locked) {
+                lock_ReleaseWrite(&scp->rw);
+                scp_locked = 0;
+            }
+            code = 0;
+        /* Prefer the error value from FetchData over rx_EndCall */
+        } else if (code == 0 && code1 != 0)
+            code = code1;
+        osi_Log0(afsd_logp, "CALL FetchData DONE");
+
+    } while (cm_Analyze(connp, userp, reqp, &scp->fid, 0, &volSync, NULL, NULL, code));
+
+  fetchingcompleted:
+    code = cm_MapRPCError(code, reqp);
+
+    if (!scp_locked)
+        lock_ObtainWrite(&scp->rw);
+
+    if (code == 0)
+        cm_MergeStatus(NULL, scp, &afsStatus, &volSync, userp, reqp, CM_MERGEFLAG_FETCHDATA);
+    else
+        InterlockedDecrement(&scp->activeRPCs);
+
+    if (code == 0)
+    {
+        if (dataVersion == scp->dataVersion)
+        {
+            osi_queueData_t *qdp = NULL;
+            cm_buf_t *bufp;
+            afs_uint32 buf_offset;
+            afs_uint32 bytes_compared = 0;
+            afs_uint32 cmp_length;
+            int md5_match = 1;
+
+            verified = 1;
+
+            while ( bytes_compared < biod->length )
+            {
+                if (qdp == NULL) {
+                    qdp = biod->bufListEndp;
+                    buf_offset = biod->offset.LowPart % cm_data.buf_blockSize;
+                } else {
+                    qdp = (osi_queueData_t *) osi_QPrev(&qdp->q);
+                    buf_offset = 0;
+                }
+                cmp_length =  cm_data.buf_blockSize - buf_offset;
+
+                osi_assertx(qdp != NULL, "null osi_queueData_t");
+                bufp = osi_GetQData(qdp);
+
+                if (memcmp(bufferp+bytes_compared, bufp->datap+buf_offset, cmp_length) != 0)
+                {
+                    verified = 0;
+                    md5_match = buf_ValidateCheckSum(bufp);
+
+                    osi_Log5(afsd_logp, "cm_VerifyDataStore verification failed scp 0x%p bufp 0x%p offset 0x%x:%08x md5 %s",
+                             scp, bufp, bufp->offset.HighPart, bufp->offset.LowPart, md5_match ? "match" : "no-match");
+                }
+                bytes_compared += cmp_length;
+            }
+        } else {
+            osi_Log4(afsd_logp, "cm_VerifyStoreData unable to verify due to data version change scp 0x%p, off 0x%x:%08x, size 0x%x",
+                     scp, biod->offset.HighPart, biod->offset.LowPart, biod->length);
+        }
+    }
+
+    if (bufferp)
+        free(bufferp);
+
+    return verified;
+}