Fix data race on mset.cfg (#6424)

derekcollison · web-flow · commit 136045968d6a · 2025-01-29T20:03:33.000-05:00
Using NATS in our unit tests with the Go data race detector turned on, we [sometimes see failures in `nats-server` like the following](https://github.com/mindersec/minder/actions/runs/13006404998/job/36274161639): ``` WARNING: DATA RACE Read at 0x00c0004ba0e8 by goroutine 41: github.com/nats-io/nats-server/v2/server.(*Account).filteredStreams() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/jetstream.go:1504 +0x3e4 github.com/nats-io/nats-server/v2/server.(*Server).jsStreamNamesRequest() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/jetstream_api.go:1662 +0x516 github.com/nats-io/nats-server/v2/server.(*Server).jsStreamNamesRequest-fm() <autogenerated>:1 +0xcb github.com/nats-io/nats-server/v2/server.(*jetStream).apiDispatch() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/jetstream_api.go:818 +0xb37 github.com/nats-io/nats-server/v2/server.(*jetStream).apiDispatch-fm() <autogenerated>:1 +0xcb github.com/nats-io/nats-server/v2/server.(*client).deliverMsg() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:3473 +0xcfe github.com/nats-io/nats-server/v2/server.(*client).processMsgResults() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:4565 +0x1206 github.com/nats-io/nats-server/v2/server.(*client).processServiceImport() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:4350 +0x1e0e github.com/nats-io/nats-server/v2/server.(*Account).addServiceImportSub.func1() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/accounts.go:2024 +0x4d github.com/nats-io/nats-server/v2/server.(*client).deliverMsg() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:3471 +0xdcf github.com/nats-io/nats-server/v2/server.(*client).processMsgResults() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:4565 +0x1206 github.com/nats-io/nats-server/v2/server.(*client).processInboundClientMsg() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:3952 +0x163d github.com/nats-io/nats-server/v2/server.(*client).processInboundMsg() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:3789 +0x88 github.com/nats-io/nats-server/v2/server.(*client).parse() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/parser.go:497 +0x362d github.com/nats-io/nats-server/v2/server.(*client).readLoop() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:1393 +0x1b18 github.com/nats-io/nats-server/v2/server.(*Server).createClientEx.func1() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/server.go:3295 +0x54 github.com/nats-io/nats-server/v2/server.(*Server).startGoRoutine.func1() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/server.go:3795 +0x59 Previous write at 0x00c0004ba0e8 by goroutine 54: github.com/nats-io/nats-server/v2/server.(*stream).updateWithAdvisory() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/stream.go:1963 +0x1b96 github.com/nats-io/nats-server/v2/server.(*stream).update() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/stream.go:1726 +0xf2c github.com/nats-io/nats-server/v2/server.(*Server).jsStreamUpdateRequest() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/jetstream_api.go:1543 +0xf2d github.com/nats-io/nats-server/v2/server.(*Server).jsStreamUpdateRequest-fm() <autogenerated>:1 +0xcb github.com/nats-io/nats-server/v2/server.(*jetStream).apiDispatch() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/jetstream_api.go:818 +0xb37 github.com/nats-io/nats-server/v2/server.(*jetStream).apiDispatch-fm() <autogenerated>:1 +0xcb github.com/nats-io/nats-server/v2/server.(*client).deliverMsg() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:3473 +0xcfe github.com/nats-io/nats-server/v2/server.(*client).processMsgResults() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:4565 +0x1206 github.com/nats-io/nats-server/v2/server.(*client).processServiceImport() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:4350 +0x1e0e github.com/nats-io/nats-server/v2/server.(*Account).addServiceImportSub.func1() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/accounts.go:2024 +0x4d github.com/nats-io/nats-server/v2/server.(*client).deliverMsg() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:3471 +0xdcf github.com/nats-io/nats-server/v2/server.(*client).processMsgResults() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:4565 +0x1206 github.com/nats-io/nats-server/v2/server.(*client).processInboundClientMsg() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:3952 +0x163d github.com/nats-io/nats-server/v2/server.(*client).processInboundMsg() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:3789 +0x88 github.com/nats-io/nats-server/v2/server.(*client).parse() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/parser.go:497 +0x362d github.com/nats-io/nats-server/v2/server.(*client).readLoop() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/client.go:1393 +0x1b18 github.com/nats-io/nats-server/v2/server.(*Server).createClientEx.func1() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/server.go:3295 +0x54 github.com/nats-io/nats-server/v2/server.(*Server).startGoRoutine.func1() /home/runner/go/pkg/mod/github.com/nats-io/nats-server/v2@v2.10.25/server/server.go:3795 +0x59 ``` Signed-off-by: Evan Anderson <evan@stacklok.com>
diff --git a/server/jetstream.go b/server/jetstream.go
@@ -1556,12 +1556,14 @@ func (a *Account) filteredStreams(filter string) []*stream {
 	var msets []*stream
 	for _, mset := range jsa.streams {
 		if filter != _EMPTY_ {
+			mset.cfgMu.RLock()
 			for _, subj := range mset.cfg.Subjects {
 				if SubjectsCollide(filter, subj) {
 					msets = append(msets, mset)
 					break
 				}
 			}
+			mset.cfgMu.RUnlock()
 		} else {
 			msets = append(msets, mset)
 		}

Original file line number	Diff line number	Diff line change
`@@ -1556,12 +1556,14 @@ func (a Account) filteredStreams(filter string) []stream {`
`1556`	`1556`	`var msets []*stream`
`1557`	`1557`	`for _, mset := range jsa.streams {`
`1558`	`1558`	`if filter != _EMPTY_ {`
	`1559`	`+ mset.cfgMu.RLock()`
`1559`	`1560`	`for _, subj := range mset.cfg.Subjects {`
`1560`	`1561`	`if SubjectsCollide(filter, subj) {`
`1561`	`1562`	`msets = append(msets, mset)`
`1562`	`1563`	`break`
`1563`	`1564`	`}`
`1564`	`1565`	`}`
	`1566`	`+ mset.cfgMu.RUnlock()`
`1565`	`1567`	`} else {`
`1566`	`1568`	`msets = append(msets, mset)`
`1567`	`1569`	`}`