From a291a0eddc0372403ff009664f92d956cd33b008 Mon Sep 17 00:00:00 2001
From: 6543 <6543@obermui.de>
Date: Wed, 1 Apr 2020 21:03:08 +0200
Subject: [PATCH] Prevent deadlock in pull_service.GetDiverging(pr) (#10905)
* Switch to use a temporary repository instead of adding remotes to the base gitea repository to prevent deadlocking the base gitea repository.
* Add documentation on how to use func **createTemporaryRepo**
---
services/pull/temp_repo.go | 2 ++
services/pull/update.go | 55 +++++++---------------------------------------
2 files changed, 10 insertions(+), 47 deletions(-)
diff --git a/services/pull/temp_repo.go b/services/pull/temp_repo.go
index ffac92ade5..91f48d0626 100644
--- a/services/pull/temp_repo.go
+++ b/services/pull/temp_repo.go
@@ -16,6 +16,8 @@ import (
"code.gitea.io/gitea/modules/log"
)
+// createTemporaryRepo creates a temporary repo with "base" for pr.BaseBranch and "tracking" for pr.HeadBranch
+// it also create a second base branch called "original_base"
func createTemporaryRepo(pr *models.PullRequest) (string, error) {
if err := pr.LoadHeadRepo(); err != nil {
log.Error("LoadHeadRepo: %v", err)
diff --git a/services/pull/update.go b/services/pull/update.go
index 66921abefa..2ccbcf00a3 100644
--- a/services/pull/update.go
+++ b/services/pull/update.go
@@ -6,8 +6,6 @@ package pull
import (
"fmt"
- "strconv"
- "strings"
"code.gitea.io/gitea/models"
"code.gitea.io/gitea/modules/git"
@@ -66,7 +64,7 @@ func IsUserAllowedToUpdate(pull *models.PullRequest, user *models.User) (bool, e
// GetDiverging determines how many commits a PR is ahead or behind the PR base branch
func GetDiverging(pr *models.PullRequest) (*git.DivergeObject, error) {
- log.Trace("PushToBaseRepo[%d]: pushing commits to base repo '%s'", pr.BaseRepoID, pr.GetGitRefName())
+ log.Trace("GetDiverging[%d]: compare commits", pr.ID)
if err := pr.LoadBaseRepo(); err != nil {
return nil, err
}
@@ -74,54 +72,17 @@ func GetDiverging(pr *models.PullRequest) (*git.DivergeObject, error) {
return nil, err
}
- headRepoPath := pr.HeadRepo.RepoPath()
- headGitRepo, err := git.OpenRepository(headRepoPath)
+ tmpRepo, err := createTemporaryRepo(pr)
if err != nil {
- return nil, fmt.Errorf("OpenRepository: %v", err)
- }
- defer headGitRepo.Close()
-
- if pr.IsSameRepo() {
- diff, err := git.GetDivergingCommits(pr.HeadRepo.RepoPath(), pr.BaseBranch, pr.HeadBranch)
- return &diff, err
- }
-
- tmpRemoteName := fmt.Sprintf("tmp-pull-%d-base", pr.ID)
- if err = headGitRepo.AddRemote(tmpRemoteName, pr.BaseRepo.RepoPath(), true); err != nil {
- return nil, fmt.Errorf("headGitRepo.AddRemote: %v", err)
+ log.Error("CreateTemporaryPath: %v", err)
+ return nil, err
}
- // Make sure to remove the remote even if the push fails
defer func() {
- if err := headGitRepo.RemoveRemote(tmpRemoteName); err != nil {
- log.Error("CountDiverging: RemoveRemote: %s", err)
+ if err := models.RemoveTemporaryPath(tmpRepo); err != nil {
+ log.Error("Merge: RemoveTemporaryPath: %s", err)
}
}()
- // $(git rev-list --count tmp-pull-1-base/master..feature) commits ahead of master
- ahead, errorAhead := checkDivergence(headRepoPath, fmt.Sprintf("%s/%s", tmpRemoteName, pr.BaseBranch), pr.HeadBranch)
- if errorAhead != nil {
- return &git.DivergeObject{}, errorAhead
- }
-
- // $(git rev-list --count feature..tmp-pull-1-base/master) commits behind master
- behind, errorBehind := checkDivergence(headRepoPath, pr.HeadBranch, fmt.Sprintf("%s/%s", tmpRemoteName, pr.BaseBranch))
- if errorBehind != nil {
- return &git.DivergeObject{}, errorBehind
- }
-
- return &git.DivergeObject{Ahead: ahead, Behind: behind}, nil
-}
-
-func checkDivergence(repoPath string, baseBranch string, targetBranch string) (int, error) {
- branches := fmt.Sprintf("%s..%s", baseBranch, targetBranch)
- cmd := git.NewCommand("rev-list", "--count", branches)
- stdout, err := cmd.RunInDir(repoPath)
- if err != nil {
- return -1, err
- }
- outInteger, errInteger := strconv.Atoi(strings.Trim(stdout, "\n"))
- if errInteger != nil {
- return -1, errInteger
- }
- return outInteger, nil
+ diff, err := git.GetDivergingCommits(tmpRepo, "base", "tracking")
+ return &diff, err
}