Before this change, resuming from an unencrypted dataset with
send.raw=true specified wouldn't work with zrepl due to overly
restrictive resume token checking.
An initial PR to fix this was made in https://github.com/zrepl/zrepl/pull/503
but it didn't address the core of the problem.
The core of the problem was that zrepl assumed that if a resume token
contained `rawok=true, compressok=true`, the resulting send would be
encrypted. But if the sender dataset was unencrypted, such a resume would
actually result in an unencrypted send.
Which could be totally legitimate but zrepl failed to recognize that.
BACKGROUND
==========
The following snippets of OpenZFS code are insightful regarding how the
various ${X}ok values in the resume token are handled:
- 6c3c5fcfbe/module/zfs/dmu_send.c (L1947-L2012)
- 6c3c5fcfbe/module/zfs/dmu_recv.c (L877-L891)
- https://github.com/openzfs/zfs/blob/6c3c5fc/lib/libzfs/libzfs_sendrecv.c#L1663-L1672
Basically, some zfs send flags make the DMU send code set some DMU send
stream featureflags, although it's not a pure mapping, i.e, which DMU
send stream flags are used depends somewhat on the dataset (e.g., is it
encrypted or not, or, does it use zstd or not).
Then, the receiver looks at some (but not all) feature flags and maps
them to ${X}ok dataset zap attributes.
These are funnelled back to the sender 1:1 through the resume_token.
And the sender turns them into lzc flags.
As an example, let's look at zfs send --raw.
if the sender requests a raw send on an unencrypted dataset, the send
stream (and hence the resume token) will not have the raw stream
featureflag set, and hence the resume token will not have the rawok
field set. Instead, it will have compressok, embedok, and depending
on whether large blocks are present in the dataset, largeblockok set.
WHAT'S ZREPL'S ROLE IN THIS?
============================
zrepl provides a virtual encrypted sendflag that is like `raw`,
but further ensures that we only send encrypted datasets.
For any other resume token stuff, it shoudn't do any checking,
because it's a futile effort to keep up with ZFS send/recv features
that are orthogonal to encryption.
CHANGES MADE IN THIS COMMIT
===========================
- Rip out a bunch of needless checking that zrepl would do during
planning. These checks were there to give better error messages,
but actually, the error messages created by the endpoint.Sender.Send
RPC upon send args validation failure are good enough.
- Add platformtests to validate all combinations of
(Unencrypted/Encrypted FS) x (send.encrypted = true | false) x (send.raw = true | false)
for cases both non-resuming and resuming send.
Additional manual testing done:
1. With zrepl 0.5, setup with unencrypted dataset, send.raw=true specified, no send.encrypted specified.
2. Observe that regular non-resuming send works, but resuming doesn't work.
3. Upgrade zrepl to this change.
4. Observe that both regular and resuming send works.
closes https://github.com/zrepl/zrepl/pull/613
From:
github.com/golang/protobuf v1.3.2
google.golang.org/grpc v1.17.0
To:
github.com/golang/protobuf v1.4.3
google.golang.org/grpc v1.35.0
google.golang.org/protobuf v1.25.0
About the two protobuf packages:
https://developers.google.com/protocol-buffers/docs/reference/go/faq
> Version v1.4.0 and higher of github.com/golang/protobuf wrap the new
implementation and permit programs to adopt the new API incrementally. For
example, the well-known types defined in github.com/golang/protobuf/ptypes are
simply aliases of those defined in the newer module. Thus,
google.golang.org/protobuf/types/known/emptypb and
github.com/golang/protobuf/ptypes/empty may be used interchangeably.
Notable Code Changes in zrepl:
- generate protobufs now contain a mutex so we can't copy them by value
anymore
- grpc.WithDialer is deprecated => use grpc.WithContextDialer instead
Go1.12 is now actually required by some of the dependencies.
Symptom: zrepl log message:
rpc error: code = Unavailable desc = transport is closing
Underlying Problem:
* rpc.NewServer was not using grpchelper.NewServer and not setting Server KeepaliveParams by itself
* and even grpchelper.NewServer didn't set a KeepaliveEnforcementPolicy
* However, KeepaliveEnforcementPolicy is necessary if the client keepalive is configured with non-default values
* .. which grpchelper.ClientConn does, and that method is used by rpc.NewClient
* rpc.Client was sending pings
* lacking server-side KeepaliveEnforcementPolicy caused grpc-hard-coded `pingStrikes` counter to go past limit of 2:
021bd5734e/internal/transport/http2_server.go (L726)
How was this debugged:
* GRPC_GO_LOG_VERBOSITY_LEVEL=99 GRPC_GO_LOG_SEVERITY_LEVEL=info PATH=/root/mockpath:$PATH zrepl daemon
* with a patch on grpc package to get more log messages on pingStrikes increases:
diff --git a/internal/transport/http2_server.go b/internal/transport/http2_server.go
index 8b04b039..f68f55ea 100644
--- a/internal/transport/http2_server.go
+++ b/internal/transport/http2_server.go
@@ -214,6 +214,7 @@ func newHTTP2Server(conn net.Conn, config *ServerConfig) (_ ServerTransport, err
if kep.MinTime == 0 {
kep.MinTime = defaultKeepalivePolicyMinTime
}
+ errorf("effective keepalive enforcement policy: %#v", kep)
done := make(chan struct{})
t := &http2Server{
ctx: context.Background(),
@@ -696,6 +697,7 @@ func (t *http2Server) handlePing(f *http2.PingFrame) {
t.controlBuf.put(pingAck)
now := time.Now()
+ errorf("transport:ping handlePing, last ping %s ago", now.Sub(t.lastPingAt))
defer func() {
t.lastPingAt = now
}()
@@ -713,11 +715,13 @@ func (t *http2Server) handlePing(f *http2.PingFrame) {
// Keepalive shouldn't be active thus, this new ping should
// have come after at least defaultPingTimeout.
if t.lastPingAt.Add(defaultPingTimeout).After(now) {
+ errorf("transport:ping strike ns < 1 && !t.kep.PermitWithoutStream")
t.pingStrikes++
}
} else {
// Check if keepalive policy is respected.
if t.lastPingAt.Add(t.kep.MinTime).After(now) {
+ errorf("transport:ping strike !(ns < 1 && !t.kep.PermitWithoutStream) kep.MinTime=%s ns=%d", t.kep.MinTime, ns)
t.pingStrikes++
}
}
fixes#181
