afs: Fix calculation of callback expiry time

Fix the calculation of the expiry time of a callback promise, as obtained
from operations like FS.FetchStatus and FS.FetchData.

The time should be based on the timestamp of the first DATA packet in the
reply and the calculation needs to turn the ktime_t timestamp into a
time64_t.

Fixes: c435ee34551e ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 26 insertions, 31 deletions

diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index d58848c357aa..388750d80cab 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -256,6 +256,23 @@ static int afs_decode_status(struct afs_call *call,
 	return ret;
 }
 
+static time64_t xdr_decode_expiry(struct afs_call *call, u32 expiry)
+{
+	return ktime_divns(call->reply_time, NSEC_PER_SEC) + expiry;
+}
+
+static void xdr_decode_AFSCallBack_raw(struct afs_call *call,
+				       struct afs_callback *cb,
+				       const __be32 **_bp)
+{
+	const __be32 *bp = *_bp;
+
+	cb->version	= ntohl(*bp++);
+	cb->expires_at	= xdr_decode_expiry(call, ntohl(*bp++));
+	cb->type	= ntohl(*bp++);
+	*_bp = bp;
+}
+
 /*
  * decode an AFSCallBack block
  */
@@ -264,46 +281,26 @@ static void xdr_decode_AFSCallBack(struct afs_call *call,
 				   const __be32 **_bp)
 {
 	struct afs_cb_interest *old, *cbi = call->cbi;
-	const __be32 *bp = *_bp;
-	u32 cb_expiry;
+	struct afs_callback cb;
+
+	xdr_decode_AFSCallBack_raw(call, &cb, _bp);
 
 	write_seqlock(&vnode->cb_lock);
 
 	if (!afs_cb_is_broken(call->cb_break, vnode, cbi)) {
-		vnode->cb_version	= ntohl(*bp++);
-		cb_expiry		= ntohl(*bp++);
-		vnode->cb_type		= ntohl(*bp++);
-		vnode->cb_expires_at	= cb_expiry + ktime_get_real_seconds();
+		vnode->cb_version	= cb.version;
+		vnode->cb_type		= cb.type;
+		vnode->cb_expires_at	= cb.expires_at;
 		old = vnode->cb_interest;
 		if (old != call->cbi) {
 			vnode->cb_interest = cbi;
 			cbi = old;
 		}
 		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
-	} else {
-		bp += 3;
 	}
 
 	write_sequnlock(&vnode->cb_lock);
 	call->cbi = cbi;
-	*_bp = bp;
-}
-
-static ktime_t xdr_decode_expiry(struct afs_call *call, u32 expiry)
-{
-	return ktime_add_ns(call->reply_time, expiry * NSEC_PER_SEC);
-}
-
-static void xdr_decode_AFSCallBack_raw(struct afs_call *call,
-				       const __be32 **_bp,
-				       struct afs_callback *cb)
-{
-	const __be32 *bp = *_bp;
-
-	cb->version	= ntohl(*bp++);
-	cb->expires_at	= xdr_decode_expiry(call, ntohl(*bp++));
-	cb->type	= ntohl(*bp++);
-	*_bp = bp;
 }
 
 /*
@@ -744,7 +741,7 @@ static int afs_deliver_fs_create_vnode(struct afs_call *call)
 				&call->expected_version, NULL);
 	if (ret < 0)
 		return ret;
-	xdr_decode_AFSCallBack_raw(call, &bp, call->reply[3]);
+	xdr_decode_AFSCallBack_raw(call, call->reply[3], &bp);
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
 	_leave(" = 0 [done]");
@@ -2168,7 +2165,7 @@ static int afs_deliver_fs_fetch_status(struct afs_call *call)
 				&call->expected_version, NULL);
 	if (ret < 0)
 		return ret;
-	xdr_decode_AFSCallBack_raw(call, &bp, callback);
+	xdr_decode_AFSCallBack_raw(call, callback, &bp);
 	xdr_decode_AFSVolSync(&bp, volsync);
 
 	_leave(" = 0 [done]");
@@ -2322,9 +2319,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		_debug("unmarshall CB array");
 		bp = call->buffer;
 		callbacks = call->reply[2];
-		callbacks[call->count].version	= ntohl(bp[0]);
-		callbacks[call->count].expires_at = xdr_decode_expiry(call, ntohl(bp[1]));
-		callbacks[call->count].type	= ntohl(bp[2]);
+		xdr_decode_AFSCallBack_raw(call, &callbacks[call->count], &bp);
 		statuses = call->reply[1];
 		if (call->count == 0 && vnode && statuses[0].abort_code == 0)
 			xdr_decode_AFSCallBack(call, vnode, &bp);