diff --git a/daemon/getattr.c b/daemon/getattr.c

index 7c5f241..7621dba 100644

--- a/daemon/getattr.c

+++ b/daemon/getattr.c

@@ -59,8 +59,19 @@ int nfs41_cached_getattr(

 static int parse_getattr(unsigned char *buffer, uint32_t length, nfs41_upcall *upcall)

 {

     int status;

+#if 1

+    EASSERT(length > 4);

+    if (length <= 4) {

+        status = ERROR_INVALID_PARAMETER;

+        goto out;

+    }

+    EASSERT(upcall->state_ref != NULL);

+    if (upcall->state_ref == NULL) {

+        status = ERROR_INVALID_PARAMETER;

+        goto out;

+    }

+#endif

     getattr_upcall_args *args = &upcall->args.getattr;

-

     status = safe_read(&buffer, &length, &args->query_class, sizeof(args->query_class));

     if (status) goto out;

     status = safe_read(&buffer, &length, &args->buf_len, sizeof(args->buf_len));

@@ -80,6 +91,21 @@ static int handle_getattr(void *daemon_context, nfs41_upcall *upcall)

     nfs41_open_state *state = upcall->state_ref;

     nfs41_file_info info = { 0 };

+#if 1

+    if (((char *)state->session) == ((char *)0xdddddddddddddddd)) {

+        eprintf("handle_getattr: Invalid session pointer 0xdddddddddddddddd\n");

+        status = ERROR_INVALID_PARAMETER;

+        goto out;

+    }

+

+    EASSERT(state->file.fh.superblock != NULL);

+    if (state->file.fh.superblock == NULL) {

+        /* gisburn: fixme: maybe this should be |ERROR_INTERNAL_ERROR| ? */

+        status = ERROR_INVALID_PARAMETER;

+        goto out;

+    }

+#endif

+

     status = nfs41_cached_getattr(state->session, &state->file, &info);

     if (status) {

         eprintf("nfs41_cached_getattr() failed with %d\n", status);

diff --git a/daemon/nfs41_ops.c b/daemon/nfs41_ops.c

index bcca070..f2a4f22 100644

--- a/daemon/nfs41_ops.c

+++ b/daemon/nfs41_ops.c

@@ -400,6 +400,9 @@ int nfs41_open(

     bool_t already_delegated = delegation->type == OPEN_DELEGATE_READ

         || delegation->type == OPEN_DELEGATE_WRITE;

+    EASSERT(parent);

+    EASSERT(parent->fh.superblock);

+

     /* depending on the claim type, OPEN expects CURRENT_FH set

      * to either the parent directory, or to the file itself */

     switch (claim->claim) {

diff --git a/daemon/open.c b/daemon/open.c

index 4b2a335..487c341 100644

--- a/daemon/open.c

+++ b/daemon/open.c

@@ -99,6 +99,24 @@ static void open_state_free(

 void nfs41_open_state_ref(

     IN nfs41_open_state *state)

 {

+#if 1

+    /*

+     * gisburn: fixme: sometimes this happens under high parallel

+     * usage with multiple mounts - but why ?

+     * 0:038> kp

+     * Child-SP          RetAddr           Call Site

+     * 0000006d`431fde10 00007ff7`32f7d905 nfsd!nfs41_open_state_ref(struct __nfs41_open_state * state = 0x00000000`00000000)+0x31

+     * 0000006d`431fdf30 00007ff7`32f4d284 nfsd!upcall_parse(unsigned char * buffer = 0x0000006d`431fe180 "???", unsigned int length = 8, struct __nfs41_upcall * upcall = 0x0000006d`431ff1e0)+0x2e5

+     * 0000006d`431fe0b0 00007ffc`1ca24c7c nfsd!thread_main(void * args = 0x00007ff7`32fb6080)+0x144

+     * 0000006d`431ffe00 00007ffc`4d4b7344 ucrtbased!thread_start<unsigned int (void * parameter = 0x0000025d`a9c6def0)+0x9c

+     * 0000006d`431ffe60 00007ffc`4efc26b1 KERNEL32!BaseThreadInitThunk+0x14

+     * 0000006d`431ffe90 00000000`00000000 ntdll!RtlUserThreadStart+0x21

+     */

+    EASSERT(state != NULL);

+    if (state == NULL)

+        return;

+#endif

+

     const LONG count = InterlockedIncrement(&state->ref_count);

     dprintf(2, "nfs41_open_state_ref(%s) count %d\n", state->path.path, count);

diff --git a/daemon/upcall.c b/daemon/upcall.c

index bd13c61..7778429 100644

--- a/daemon/upcall.c

+++ b/daemon/upcall.c

@@ -121,6 +121,7 @@ int upcall_parse(

     /* parse the operation's arguments */

     op = g_upcall_op_table[upcall->opcode];

     if (op && op->parse) {

+        EASSERT(length > 0);

         status = op->parse(buffer, length, upcall);

         if (status) {

             eprintf("parsing of upcall '%s' failed with %d.\n",

diff --git a/dll/nfs41_np.c b/dll/nfs41_np.c

index 8b259bb..6d3429f 100644

--- a/dll/nfs41_np.c

+++ b/dll/nfs41_np.c

@@ -28,6 +28,8 @@

 #include "nfs41_np.h"

 #include "options.h"

+#define DBG 1

+

 #ifdef DBG

 #define DbgP(_x_) NFS41DbgPrint _x_

 #else

diff --git a/sys/nfs41_build_features.h b/sys/nfs41_build_features.h

index 93ee7a9..d43334a 100644

--- a/sys/nfs41_build_features.h

+++ b/sys/nfs41_build_features.h

@@ -32,19 +32,19 @@

 /*

  * NFS41_DRIVER_FEATURE_LOCAL_UIDGID_IN_NFSV3ATTRIBUTES - return local uid/gid values

  */

-// #define NFS41_DRIVER_FEATURE_LOCAL_UIDGID_IN_NFSV3ATTRIBUTES 1

+#define NFS41_DRIVER_FEATURE_LOCAL_UIDGID_IN_NFSV3ATTRIBUTES 1

 /*

  * NFS41_DRIVER_FEATURE_MAP_UNMAPPED_USER_TO_UNIXUSER_SID - give NFS

  * files which do not map to a local account a SID in the

  * Unix_User+x/Unix_Group+x range

  */

-// #define NFS41_DRIVER_FEATURE_MAP_UNMAPPED_USER_TO_UNIXUSER_SID 1

+#define NFS41_DRIVER_FEATURE_MAP_UNMAPPED_USER_TO_UNIXUSER_SID 1

 /*

  * NFS41_DRIVER_FEATURE_NAMESERVICE_CYGWIN - use Cygwin /usr/bin/getent

  * as "name service"

  */

-// #define NFS41_DRIVER_FEATURE_NAMESERVICE_CYGWIN 1

+#define NFS41_DRIVER_FEATURE_NAMESERVICE_CYGWIN 1

 #endif /* !_NFS41_DRIVER_BUILDFEATURES_ */

diff --git a/sys/nfs41_driver.c b/sys/nfs41_driver.c

--- a/sys/nfs41_driver.c

+++ b/sys/nfs41_driver.c

@@ -54,7 +54,7 @@

 //#define DEBUG_LOCK

 //#define DEBUG_MISC

 #define DEBUG_TIME_BASED_COHERENCY

-//#define DEBUG_MOUNT

+#define DEBUG_MOUNT

 //#define DEBUG_VOLUME_QUERY

 //#define ENABLE_TIMINGS

@@ -260,6 +260,40 @@ typedef struct _updowncall_list {

 } nfs41_updowncall_list;

 nfs41_updowncall_list upcall, downcall;

+

+

+/* In order to cooperate with other network providers,

+ * we only claim paths of the format '\\server\nfs4\path' */

+DECLARE_CONST_UNICODE_STRING(NfsPrefix, L"\\nfs4");

+DECLARE_CONST_UNICODE_STRING(AUTH_SYS_NAME, L"sys");

+DECLARE_CONST_UNICODE_STRING(AUTHGSS_KRB5_NAME, L"krb5");

+DECLARE_CONST_UNICODE_STRING(AUTHGSS_KRB5I_NAME, L"krb5i");

+DECLARE_CONST_UNICODE_STRING(AUTHGSS_KRB5P_NAME, L"krb5p");

+DECLARE_CONST_UNICODE_STRING(SLASH, L"\\");

+DECLARE_CONST_UNICODE_STRING(EMPTY_STRING, L"");

+

+#define SERVER_NAME_BUFFER_SIZE         1024

+#define MOUNT_CONFIG_RW_SIZE_MIN        1024

+#define MOUNT_CONFIG_RW_SIZE_DEFAULT    1048576

+#define MOUNT_CONFIG_RW_SIZE_MAX        1048576

+#define MAX_SEC_FLAVOR_LEN              12

+#define UPCALL_TIMEOUT_DEFAULT          50  /* in seconds */

+

+typedef struct _NFS41_MOUNT_CONFIG {

+    DWORD ReadSize;

+    DWORD WriteSize;

+    BOOLEAN ReadOnly;

+    BOOLEAN write_thru;

+    BOOLEAN nocache;

+    WCHAR srv_buffer[SERVER_NAME_BUFFER_SIZE];

+    UNICODE_STRING SrvName; /* hostname, or hostname@port */

+    WCHAR mntpt_buffer[MAX_PATH];

+    UNICODE_STRING MntPt;

+    WCHAR sec_flavor[MAX_SEC_FLAVOR_LEN];

+    UNICODE_STRING SecFlavor;

+    DWORD timeout;

+} NFS41_MOUNT_CONFIG, *PNFS41_MOUNT_CONFIG;

+

 typedef struct _nfs41_mount_entry {

     LIST_ENTRY next;

     LUID login_id;

@@ -267,6 +301,7 @@ typedef struct _nfs41_mount_entry {

     HANDLE gss_session;

     HANDLE gssi_session;

     HANDLE gssp_session;

+    NFS41_MOUNT_CONFIG Config;

 } nfs41_mount_entry;

 typedef struct _nfs41_mount_list {

@@ -310,37 +345,6 @@ typedef struct _nfs41_mount_list {

                                   next)));                  \

             ExReleaseFastMutex(&lock);

-/* In order to cooperate with other network providers,

- * we only claim paths of the format '\\server\nfs4\path' */

-DECLARE_CONST_UNICODE_STRING(NfsPrefix, L"\\nfs4");

-DECLARE_CONST_UNICODE_STRING(AUTH_SYS_NAME, L"sys");

-DECLARE_CONST_UNICODE_STRING(AUTHGSS_KRB5_NAME, L"krb5");

-DECLARE_CONST_UNICODE_STRING(AUTHGSS_KRB5I_NAME, L"krb5i");

-DECLARE_CONST_UNICODE_STRING(AUTHGSS_KRB5P_NAME, L"krb5p");

-DECLARE_CONST_UNICODE_STRING(SLASH, L"\\");

-DECLARE_CONST_UNICODE_STRING(EMPTY_STRING, L"");

-

-#define SERVER_NAME_BUFFER_SIZE         1024

-#define MOUNT_CONFIG_RW_SIZE_MIN        1024

-#define MOUNT_CONFIG_RW_SIZE_DEFAULT    1048576

-#define MOUNT_CONFIG_RW_SIZE_MAX        1048576

-#define MAX_SEC_FLAVOR_LEN              12

-#define UPCALL_TIMEOUT_DEFAULT          50  /* in seconds */

-

-typedef struct _NFS41_MOUNT_CONFIG {

-    DWORD ReadSize;

-    DWORD WriteSize;

-    BOOLEAN ReadOnly;

-    BOOLEAN write_thru;

-    BOOLEAN nocache;

-    WCHAR srv_buffer[SERVER_NAME_BUFFER_SIZE];

-    UNICODE_STRING SrvName; /* hostname, or hostname@port */

-    WCHAR mntpt_buffer[MAX_PATH];

-    UNICODE_STRING MntPt;

-    WCHAR sec_flavor[MAX_SEC_FLAVOR_LEN];

-    UNICODE_STRING SecFlavor;

-    DWORD timeout;

-} NFS41_MOUNT_CONFIG, *PNFS41_MOUNT_CONFIG;

 typedef struct _NFS41_NETROOT_EXTENSION {

     NODE_TYPE_CODE          NodeTypeCode;

@@ -475,6 +479,14 @@ nfs41_start_driver_state nfs41_start_state = NFS41_START_DRIVER_STARTABLE;

 NTSTATUS map_readwrite_errors(DWORD status);

+

+void copy_nfs41_mount_config(NFS41_MOUNT_CONFIG *dest, NFS41_MOUNT_CONFIG *src)

+{

+    RtlCopyMemory(dest, src, sizeof(NFS41_MOUNT_CONFIG));

+    dest->SrvName.Buffer = dest->srv_buffer;

+    dest->MntPt.Buffer = dest->mntpt_buffer;

+}

+

 void print_debug_header(

     PRX_CONTEXT RxContext)

 {

     IN ULONG EaLength,

     IN OUT PNFS41_MOUNT_CONFIG Config)

 {

+    DbgP("----> nfs41_MountConfig_ParseOptions(EaBuffer=%p,EaLength=%ld)\n",

+        (void *)EaBuffer,

+        (long)EaLength);

     NTSTATUS  status = STATUS_SUCCESS;

     PFILE_FULL_EA_INFORMATION Option;

     LPWSTR Name;

     UNICODE_STRING  usValue;

     Option = EaBuffer;

     while (status == STATUS_SUCCESS) {

+        DbgP("Option=%p\n", (void *)Option);

         Name = (LPWSTR)Option->EaName;

         NameLen = Option->EaNameLength/sizeof(WCHAR);

+        DbgP("nfs41_MountConfig_ParseOptions: Name='%*S'/NameLen=%d\n",

+            (int)NameLen, Name, (int)NameLen);

+

         usValue.Length = usValue.MaximumLength = Option->EaValueLength;

         usValue.Buffer = (PWCH)(Option->EaName +

             Option->EaNameLength + sizeof(WCHAR));

+        DbgP("nfs41_MountConfig_ParseOptions: option/usValue='%wZ'/%ld\n",

+            &usValue, (long)usValue.Length);

+

         if (wcsncmp(L"ro", Name, NameLen) == 0) {

             status = nfs41_MountConfig_ParseBoolean(Option, &usValue,

                 FALSE, &Config->ReadOnly);

             ((PBYTE)Option + Option->NextEntryOffset);

     }

+    DbgP("<---- nfs41_MountConfig_ParseOptions, status=%ld\n", (long)status);

     return status;

 }

     if (pCreateNetRootContext->RxContext->Create.EaLength) {

         /* Codepath for nfs_mount.exe */

+            pCreateNetRootContext->RxContext->Create.EaBuffer,

+            (long)pCreateNetRootContext->RxContext->Create.EaLength);

         /* parse the extended attributes for mount options */

         status = nfs41_MountConfig_ParseOptions(

         pVNetRootContext->nocache = Config->nocache;

     } else {

         /* use the SRV_CALL name (without leading \) as the hostname */

         Config->SrvName.Buffer = pSrvCall->pSrvCallName->Buffer + 1;

             pSrvCall->pSrvCallName->Length - sizeof(WCHAR);

         Config->SrvName.MaximumLength =

             pSrvCall->pSrvCallName->MaximumLength - sizeof(WCHAR);

+        status = nfs41_GetLUID(&luid);

+        if (status)

+            goto out_free;

+

+        PLIST_ENTRY pEntry;

+

+        ExAcquireFastMutex(&pNetRootContext->mountLock);

+        pEntry = &pNetRootContext->mounts.head;

+        pEntry = pEntry->Flink;

+        while (pEntry != NULL) {

+            existing_mount = (nfs41_mount_entry *)CONTAINING_RECORD(pEntry,

+                    nfs41_mount_entry, next);

+

+            if (RtlEqualLuid(&luid, &existing_mount->login_id)) {

+                /* found existing mount */

+                copy_nfs41_mount_config(Config, &existing_mount->Config);

+                status = STATUS_SUCCESS;

+                break;

+            if (pEntry->Flink == &pNetRootContext->mounts.head)

+                break;

+            pEntry = pEntry->Flink;

+        }

+        ExReleaseFastMutex(&pNetRootContext->mountLock);

+

+            goto out_free;

+        pVNetRootContext->read_only = Config->ReadOnly;

+        pVNetRootContext->write_thru = Config->write_thru;

+        pVNetRootContext->nocache = Config->nocache;

+

+

     pVNetRootContext->MountPathLen = Config->MntPt.Length;

     pVNetRootContext->timeout = Config->timeout;

     }