afs: support the CB.ProbeUuid RPC op

Add support for the CB.ProbeUuid cache manager RPC op.  This allows a modern
OpenAFS server to quickly ask if the client has been rebooted.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/afs/afs_cm.h b/fs/afs/afs_cm.h
index 5f62f3e..255f5dd 100644 (file)
--- a/fs/afs/afs_cm.h
+++ b/fs/afs/afs_cm.h
@@ -24,6 +24,7 @@ enum AFS_CM_Operations {
        CBGetXStatsVersion      = 209,  /* get version of extended statistics */
        CBGetXStats             = 210,  /* get contents of extended statistics data */
        CBInitCallBackState3    = 213,  /* initialise callback state, version 3 */
+       CBProbeUuid             = 214,  /* check the client hasn't rebooted */
        CBTellMeAboutYourself   = 65538, /* get client capabilities */
 };
 

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 75da3d0..eb76548 100644 (file)
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -26,6 +26,7 @@ static int afs_deliver_cb_init_call_back_state3(struct afs_call *,
                                                struct sk_buff *, bool);
 static int afs_deliver_cb_probe(struct afs_call *, struct sk_buff *, bool);
 static int afs_deliver_cb_callback(struct afs_call *, struct sk_buff *, bool);
+static int afs_deliver_cb_probe_uuid(struct afs_call *, struct sk_buff *, bool);
 static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *,
                                                 struct sk_buff *, bool);
 static void afs_cm_destructor(struct afs_call *);
@@ -71,6 +72,16 @@ static const struct afs_call_type afs_SRXCBProbe = {
 };
 
 /*
+ * CB.ProbeUuid operation type
+ */
+static const struct afs_call_type afs_SRXCBProbeUuid = {
+       .name           = "CB.ProbeUuid",
+       .deliver        = afs_deliver_cb_probe_uuid,
+       .abort_to_error = afs_abort_to_error,
+       .destructor     = afs_cm_destructor,
+};
+
+/*
  * CB.TellMeAboutYourself operation type
  */
 static const struct afs_call_type afs_SRXCBTellMeAboutYourself = {
@@ -393,6 +404,102 @@ static int afs_deliver_cb_probe(struct afs_call *call, struct sk_buff *skb,
 }
 
 /*
+ * allow the fileserver to quickly find out if the fileserver has been rebooted
+ */
+static void SRXAFSCB_ProbeUuid(struct work_struct *work)
+{
+       struct afs_call *call = container_of(work, struct afs_call, work);
+       struct afs_uuid *r = call->request;
+
+       struct {
+               __be32  match;
+       } reply;
+
+       _enter("");
+
+
+       if (memcmp(r, &afs_uuid, sizeof(afs_uuid)) == 0)
+               reply.match = htonl(0);
+       else
+               reply.match = htonl(1);
+
+       afs_send_simple_reply(call, &reply, sizeof(reply));
+       _leave("");
+}
+
+/*
+ * deliver request data to a CB.ProbeUuid call
+ */
+static int afs_deliver_cb_probe_uuid(struct afs_call *call, struct sk_buff *skb,
+                                    bool last)
+{
+       struct afs_uuid *r;
+       unsigned loop;
+       __be32 *b;
+       int ret;
+
+       _enter("{%u},{%u},%d", call->unmarshall, skb->len, last);
+
+       if (skb->len > 0)
+               return -EBADMSG;
+       if (!last)
+               return 0;
+
+       switch (call->unmarshall) {
+       case 0:
+               call->offset = 0;
+               call->buffer = kmalloc(11 * sizeof(__be32), GFP_KERNEL);
+               if (!call->buffer)
+                       return -ENOMEM;
+               call->unmarshall++;
+
+       case 1:
+               _debug("extract UUID");
+               ret = afs_extract_data(call, skb, last, call->buffer,
+                                      11 * sizeof(__be32));
+               switch (ret) {
+               case 0:         break;
+               case -EAGAIN:   return 0;
+               default:        return ret;
+               }
+
+               _debug("unmarshall UUID");
+               call->request = kmalloc(sizeof(struct afs_uuid), GFP_KERNEL);
+               if (!call->request)
+                       return -ENOMEM;
+
+               b = call->buffer;
+               r = call->request;
+               r->time_low                     = ntohl(b[0]);
+               r->time_mid                     = ntohl(b[1]);
+               r->time_hi_and_version          = ntohl(b[2]);
+               r->clock_seq_hi_and_reserved    = ntohl(b[3]);
+               r->clock_seq_low                = ntohl(b[4]);
+
+               for (loop = 0; loop < 6; loop++)
+                       r->node[loop] = ntohl(b[loop + 5]);
+
+               call->offset = 0;
+               call->unmarshall++;
+
+       case 2:
+               _debug("trailer");
+               if (skb->len != 0)
+                       return -EBADMSG;
+               break;
+       }
+
+       if (!last)
+               return 0;
+
+       call->state = AFS_CALL_REPLYING;
+
+       INIT_WORK(&call->work, SRXAFSCB_ProbeUuid);
+       schedule_work(&call->work);
+       return 0;
+}
+
+/*
  * allow the fileserver to ask about the cache manager's capabilities
  */
 static void SRXAFSCB_TellMeAboutYourself(struct work_struct *work)