[PVFS2-CVS] commit by robl in pvfs2-1/src/kernel/linux-2.6: devpvfs2-req.c pvfs2-kernel.h

[CVS commit program]

Update of /projects/cvsroot/pvfs2-1/src/kernel/linux-2.6
In directory parlweb:/tmp/cvs-serv10702/src/kernel/linux-2.6

Modified Files:
	devpvfs2-req.c pvfs2-kernel.h 
Log Message:
[pcarns]: add a protocol version to the pvfs2 device communication.  ensures
clients and the kernel module come from the same source tree, but also has the
pleasing side effect of 8-byte aligning access to the header of the request.


Index: devpvfs2-req.c
===================================================================
RCS file: /projects/cvsroot/pvfs2-1/src/kernel/linux-2.6/devpvfs2-req.c,v
diff -u -w -p -u -r1.49 -r1.50
--- devpvfs2-req.c	29 Sep 2005 18:15:05 -0000	1.49
+++ devpvfs2-req.c	29 Sep 2005 22:28:57 -0000	1.50
@@ -1,6 +1,9 @@
 /*
  * (C) 2001 Clemson University and The University of Chicago
  *
+ * Changes by Acxiom Corporation to add protocol version to kernel
+ * communication, Copyright © Acxiom Corporation, 2005.
+ *
  * See COPYING in top-level directory.
  */
 
@@ -90,6 +93,7 @@ static ssize_t pvfs2_devreq_read(
     int ret = 0, len = 0;
     pvfs2_kernel_op_t *cur_op = NULL;
     static int32_t magic = PVFS2_DEVREQ_MAGIC;
+    int32_t proto_ver = PVFS_KERNEL_PROTO_VERSION;
 
     if (!(file->f_flags & O_NONBLOCK))
     {
@@ -159,18 +163,22 @@ static ssize_t pvfs2_devreq_read(
         len = MAX_ALIGNED_DEV_REQ_UPSIZE;
         if ((size_t) len <= count)
         {
-            ret = copy_to_user(buf, &magic, sizeof(int32_t));
+            ret = copy_to_user(buf, &proto_ver, sizeof(int32_t));
             if (ret == 0)
             {
-                ret = copy_to_user(buf + sizeof(int32_t),
+                ret = copy_to_user(buf + sizeof(int32_t), &magic, sizeof(int32_t));
+                if (ret == 0)
+                {
+                    ret = copy_to_user(buf + 2*sizeof(int32_t),
                                    &cur_op->tag, sizeof(uint64_t));
                 if (ret == 0)
                 {
                     ret = copy_to_user(
-                        buf + sizeof(int32_t) + sizeof(uint64_t),
+                            buf + 2*sizeof(int32_t) + sizeof(uint64_t),
                         &cur_op->upcall, sizeof(pvfs2_upcall_t));
                 }
             }
+            }
 
             if (ret)
             {
@@ -211,6 +219,7 @@ static ssize_t pvfs2_devreq_writev(
     int ret = 0, num_remaining = max_downsize;
     int payload_size = 0;
     int32_t magic = 0;
+    int32_t proto_ver = 0;
     uint64_t tag = 0;
 
     buffer = kmem_cache_alloc(dev_req_cache, PVFS2_CACHE_ALLOC_FLAGS);
@@ -240,15 +249,34 @@ static ssize_t pvfs2_devreq_writev(
 	payload_size += iov[i].iov_len;
     }
 
+    /* these elements are currently 8 byte aligned (8 bytes for (version +  
+     * magic) 8 bytes for tag).  If you add another element, either make it 8
+     * bytes big, or use get_unaligned when asigning  */
     ptr = buffer;
+    proto_ver = *((int32_t *)ptr);
+    ptr += sizeof(int32_t);
+
     magic = *((int32_t *)ptr);
     ptr += sizeof(int32_t);
 
-    /* used to be an assignment, but that would trigger an unaligned memory
-     * access on ia64 */
-    tag = get_unaligned((uint64_t*)ptr);
+    tag = *((uint64_t *)ptr);
     ptr += sizeof(uint64_t);
 
+    if (magic != PVFS2_DEVREQ_MAGIC)
+    {
+        pvfs2_error("Error: Device magic number does not match.\n");
+        kmem_cache_free(dev_req_cache, buffer);
+        return -EPROTO;
+    }
+    if (proto_ver != PVFS_KERNEL_PROTO_VERSION)
+    {
+        pvfs2_error("Error: Device protocol version numbers do not match.\n");
+        pvfs2_error("Please check that your pvfs2 module and pvfs2-client versions are consistent.\n");
+        kmem_cache_free(dev_req_cache, buffer);
+        return -EPROTO;
+    }
+
+
     /* lookup (and remove) the op based on the tag */
     hash_link = qhash_search_and_remove(htable_ops_in_progress, &(tag));
     if (hash_link)
@@ -257,7 +285,7 @@ static ssize_t pvfs2_devreq_writev(
 	if (op)
 	{
 	    /* cut off magic and tag from payload size */
-	    payload_size -= (sizeof(int32_t) + sizeof(uint64_t));
+	    payload_size -= (2*sizeof(int32_t) + sizeof(uint64_t));
 	    if (payload_size <= sizeof(pvfs2_downcall_t))
 	    {
 		/* copy the passed in downcall into the op */

Index: pvfs2-kernel.h
===================================================================
RCS file: /projects/cvsroot/pvfs2-1/src/kernel/linux-2.6/pvfs2-kernel.h,v
diff -u -w -p -u -r1.98 -r1.99
--- pvfs2-kernel.h	29 Sep 2005 18:23:13 -0000	1.98
+++ pvfs2-kernel.h	29 Sep 2005 22:28:57 -0000	1.99
@@ -139,9 +139,9 @@ do {                                    
 #define PVFS2_MAX_MOUNT_OPT_LEN        0x00000080
 #define PVFS2_NUM_READDIR_RETRIES      0x0000000A
 
-#define MAX_DEV_REQ_UPSIZE (sizeof(int32_t) +   \
+#define MAX_DEV_REQ_UPSIZE (2*sizeof(int32_t) +   \
 sizeof(uint64_t) + sizeof(pvfs2_upcall_t))
-#define MAX_DEV_REQ_DOWNSIZE (sizeof(int32_t) + \
+#define MAX_DEV_REQ_DOWNSIZE (2*sizeof(int32_t) + \
 sizeof(uint64_t) + sizeof(pvfs2_downcall_t))
 
 #define BITS_PER_LONG_DIV_8 (BITS_PER_LONG >> 3)