afs: Use the operation issue time instead of the reply time for callbacks

rxrpc and kafs between them try to use the receive timestamp on the first
data packet (ie. the one with sequence number 1) as a base from which to
calculate the time at which callback promise and lock expiration occurs.

However, we don't know how long it took for the server to send us the reply
from it having completed the basic part of the operation - it might then,
for instance, have to send a bunch of a callback breaks, depending on the
particular operation.

Fix this by using the time at which the operation is issued on the client
as a base instead.  That should never be longer than the server's idea of
the expiry time.

Fixes: 781070551c26 ("afs: Fix calculation of callback expiry time")
Fixes: 2070a3e44962 ("rxrpc: Allow the reply time to be obtained on a client call")
Suggested-by: Jeffrey E Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>

diff --git a/fs/afs/flock.c b/fs/afs/flock.c
index c4210a3..bbcc5af 100644 (file)
--- a/fs/afs/flock.c
+++ b/fs/afs/flock.c
@@ -76,7 +76,7 @@ void afs_lock_op_done(struct afs_call *call)
        if (call->error == 0) {
                spin_lock(&vnode->lock);
                trace_afs_flock_ev(vnode, NULL, afs_flock_timestamp, 0);
-               vnode->locked_at = call->reply_time;
+               vnode->locked_at = call->issue_time;
                afs_schedule_lock_extension(vnode);
                spin_unlock(&vnode->lock);
        }

diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 4943413..7d37f63 100644 (file)
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -131,7 +131,7 @@ bad:
 
 static time64_t xdr_decode_expiry(struct afs_call *call, u32 expiry)
 {
-       return ktime_divns(call->reply_time, NSEC_PER_SEC) + expiry;
+       return ktime_divns(call->issue_time, NSEC_PER_SEC) + expiry;
 }
 
 static void xdr_decode_AFSCallBack(const __be32 **_bp,

diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 64ad554..723d162 100644 (file)
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -137,7 +137,6 @@ struct afs_call {
        bool                    need_attention; /* T if RxRPC poked us */
        bool                    async;          /* T if asynchronous */
        bool                    upgrade;        /* T to request service upgrade */
-       bool                    have_reply_time; /* T if have got reply_time */
        bool                    intr;           /* T if interruptible */
        bool                    unmarshalling_error; /* T if an unmarshalling error occurred */
        u16                     service_id;     /* Actual service ID (after upgrade) */
@@ -151,7 +150,7 @@ struct afs_call {
                } __attribute__((packed));
                __be64          tmp64;
        };
-       ktime_t                 reply_time;     /* Time of first reply packet */
+       ktime_t                 issue_time;     /* Time of issue of operation */
 };
 
 struct afs_call_type {

diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index d5c4785..eccc3cd 100644 (file)
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -351,6 +351,7 @@ void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
        if (call->max_lifespan)
                rxrpc_kernel_set_max_life(call->net->socket, rxcall,
                                          call->max_lifespan);
+       call->issue_time = ktime_get_real();
 
        /* send the request */
        iov[0].iov_base = call->request;
@@ -501,12 +502,6 @@ static void afs_deliver_to_call(struct afs_call *call)
                        return;
                }
 
-               if (!call->have_reply_time &&
-                   rxrpc_kernel_get_reply_time(call->net->socket,
-                                               call->rxcall,
-                                               &call->reply_time))
-                       call->have_reply_time = true;
-
                ret = call->type->deliver(call);
                state = READ_ONCE(call->state);
                if (ret == 0 && call->unmarshalling_error)

diff --git a/fs/afs/yfsclient.c b/fs/afs/yfsclient.c
index fdc7d67..11571cc 100644 (file)
--- a/fs/afs/yfsclient.c
+++ b/fs/afs/yfsclient.c
@@ -232,8 +232,7 @@ static void xdr_decode_YFSCallBack(const __be32 **_bp,
        struct afs_callback *cb = &scb->callback;
        ktime_t cb_expiry;
 
-       cb_expiry = call->reply_time;
-       cb_expiry = ktime_add(cb_expiry, xdr_to_u64(x->expiration_time) * 100);
+       cb_expiry = ktime_add(call->issue_time, xdr_to_u64(x->expiration_time) * 100);
        cb->expires_at  = ktime_divns(cb_expiry, NSEC_PER_SEC);
        scb->have_cb    = true;
        *_bp += xdr_size(x);