[PATCH] AFS: Support the CB.ProbeUuid RPC op

From: David Howells
Date: Thu Apr 24 2008 - 18:57:39 EST


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@xxxxxxxxxx>
---

fs/afs/afs_cm.h | 1
fs/afs/cmservice.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 108 insertions(+), 0 deletions(-)


diff --git a/fs/afs/afs_cm.h b/fs/afs/afs_cm.h
index 5f62f3e..255f5dd 100644
--- 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
--- 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)

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