dashboard/app: add support for disabling fix bisection

* Allow fix bisection to be disabled on kernel repos to which force-pushes
occur.
* Pending fix bisection jobs for KernelRepo with FixBisectionDisabled will have
to be deleted manually.
* Add TestFixBisectionsDisabled.

Closes #1365

4 files changed, 67 insertions, 2 deletions

diff --git a/dashboard/app/app_test.go b/dashboard/app/app_test.go
index 89ef7ff12..61773bd6c 100644
--- a/dashboard/app/app_test.go
+++ b/dashboard/app/app_test.go
@@ -98,6 +98,13 @@ var testConfig = &GlobalConfig{
 					Alias:  "repo10alias",
 					CC:     []string{"maintainers@repo10.org", "bugs@repo10.org"},
 				},
+				{
+					URL:                  "git://syzkaller.org",
+					Branch:               "branch20",
+					Alias:                "repo20",
+					CC:                   []string{"maintainers@repo20.org", "bugs@repo20.org"},
+					FixBisectionDisabled: true,
+				},
 			},
 			Managers: map[string]ConfigManager{
 				"restricted-manager": {
diff --git a/dashboard/app/config.go b/dashboard/app/config.go
index 46a2b9597..1f5b3c0a5 100644
--- a/dashboard/app/config.go
+++ b/dashboard/app/config.go
@@ -154,6 +154,8 @@ type KernelRepo struct {
 	ReportingPriority int
 	// Additional CC list to add to all bugs reported on this repo.
 	CC []string
+	// Determines if fix bisection should be disabled on this repo.
+	FixBisectionDisabled bool
 }
 
 var (
diff --git a/dashboard/app/jobs.go b/dashboard/app/jobs.go
index 3a158840c..e7c908f2d 100644
--- a/dashboard/app/jobs.go
+++ b/dashboard/app/jobs.go
@@ -266,7 +266,7 @@ func findBugsForBisection(c context.Context, managers map[string]bool, reproLeve
 		if !shouldBisectBug(bug, managers) {
 			continue
 		}
-		crash, crashKey, err := bisectCrashForBug(c, keys[bi], managers)
+		crash, crashKey, err := bisectCrashForBug(c, bug, keys[bi], managers, jobType)
 		if err != nil {
 			return nil, nil, err
 		}
@@ -293,7 +293,7 @@ func shouldBisectBug(bug *Bug, managers map[string]bool) bool {
 	return false
 }
 
-func bisectCrashForBug(c context.Context, bugKey *db.Key, managers map[string]bool) (
+func bisectCrashForBug(c context.Context, bug *Bug, bugKey *db.Key, managers map[string]bool, jobType JobType) (
 	*Crash, *db.Key, error) {
 	crashes, crashKeys, err := queryCrashesForBug(c, bugKey, maxCrashes)
 	if err != nil {
@@ -303,11 +303,27 @@ func bisectCrashForBug(c context.Context, bugKey *db.Key, managers map[string]bo
 		if crash.ReproSyz == 0 || !managers[crash.Manager] {
 			continue
 		}
+		if ok, err := shouldBisectCrash(c, bug, crash, jobType); err != nil {
+			return nil, nil, err
+		} else if !ok {
+			continue
+		}
 		return crash, crashKeys[ci], nil
 	}
 	return nil, nil, nil
 }
 
+func shouldBisectCrash(c context.Context, bug *Bug, crash *Crash, jobType JobType) (bool, error) {
+	if jobType != JobBisectFix {
+		return true, nil
+	}
+	build, err := loadBuild(c, bug.Namespace, crash.BuildID)
+	if err != nil {
+		return false, err
+	}
+	return !kernelRepoInfo(build).FixBisectionDisabled, nil
+}
+
 func createBisectJobForBug(c context.Context, bug0 *Bug, crash *Crash, bugKey, crashKey *db.Key, jobType JobType) (
 	*Job, *db.Key, error) {
 	build, err := loadBuild(c, bug0.Namespace, crash.BuildID)
diff --git a/dashboard/app/jobs_test.go b/dashboard/app/jobs_test.go
index 7966c0228..b845c948b 100644
--- a/dashboard/app/jobs_test.go
+++ b/dashboard/app/jobs_test.go
@@ -639,3 +639,43 @@ func TestFixBisectionsListed(t *testing.T) {
 	c.expectEQ(err, nil)
 	c.expectTrue(!bytes.Contains(content, []byte("All fix bisections")))
 }
+
+// Test that fix bisections do not occur if Repo has NoFixBisections set.
+func TestFixBisectionsDisabled(t *testing.T) {
+	c := NewCtx(t)
+	defer c.Close()
+
+	// Upload a crash report
+	build := testBuild(20)
+	build.KernelRepo = "git://syzkaller.org"
+	c.client2.UploadBuild(build)
+	crash := testCrashWithRepro(build, 20)
+	c.client2.ReportCrash(crash)
+	c.client2.pollEmailBug()
+
+	// Receive the JobBisectCause.
+	resp := c.client2.pollJobs(build.Manager)
+	c.client2.expectNE(resp.ID, "")
+	c.client2.expectEQ(resp.Type, dashapi.JobBisectCause)
+	done := &dashapi.JobDoneReq{
+		ID:    resp.ID,
+		Error: []byte("testBisectFixRetry:JobBisectCause"),
+	}
+	c.client2.expectOK(c.client2.JobDone(done))
+
+	// Advance time by 30 days and read out any notification emails.
+	{
+		c.advanceTime(30 * 24 * time.Hour)
+		msg := c.client2.pollEmailBug()
+		c.expectEQ(msg.Subject, "title20")
+		c.expectTrue(strings.Contains(msg.Body, "Sending this report upstream."))
+
+		msg = c.client2.pollEmailBug()
+		c.expectEQ(msg.Subject, "title20")
+		c.expectTrue(strings.Contains(msg.Body, "syzbot found the following crash"))
+	}
+
+	// Ensure that we do not get a JobBisectFix.
+	resp = c.client2.pollJobs(build.Manager)
+	c.client2.expectEQ(resp.ID, "")
+}