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**
This commit is contained in:
6543 2020-04-01 21:03:08 +02:00 committed by GitHub
parent d501aec427
commit a291a0eddc
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2 changed files with 10 additions and 47 deletions

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@ -16,6 +16,8 @@ import (
"code.gitea.io/gitea/modules/log" "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) { func createTemporaryRepo(pr *models.PullRequest) (string, error) {
if err := pr.LoadHeadRepo(); err != nil { if err := pr.LoadHeadRepo(); err != nil {
log.Error("LoadHeadRepo: %v", err) log.Error("LoadHeadRepo: %v", err)

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@ -6,8 +6,6 @@ package pull
import ( import (
"fmt" "fmt"
"strconv"
"strings"
"code.gitea.io/gitea/models" "code.gitea.io/gitea/models"
"code.gitea.io/gitea/modules/git" "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 // GetDiverging determines how many commits a PR is ahead or behind the PR base branch
func GetDiverging(pr *models.PullRequest) (*git.DivergeObject, error) { 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 { if err := pr.LoadBaseRepo(); err != nil {
return nil, err return nil, err
} }
@ -74,54 +72,17 @@ func GetDiverging(pr *models.PullRequest) (*git.DivergeObject, error) {
return nil, err return nil, err
} }
headRepoPath := pr.HeadRepo.RepoPath() tmpRepo, err := createTemporaryRepo(pr)
headGitRepo, err := git.OpenRepository(headRepoPath)
if err != nil { if err != nil {
return nil, fmt.Errorf("OpenRepository: %v", err) log.Error("CreateTemporaryPath: %v", err)
return nil, 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)
}
// Make sure to remove the remote even if the push fails
defer func() { defer func() {
if err := headGitRepo.RemoveRemote(tmpRemoteName); err != nil { if err := models.RemoveTemporaryPath(tmpRepo); err != nil {
log.Error("CountDiverging: RemoveRemote: %s", err) log.Error("Merge: RemoveTemporaryPath: %s", err)
} }
}() }()
// $(git rev-list --count tmp-pull-1-base/master..feature) commits ahead of master diff, err := git.GetDivergingCommits(tmpRepo, "base", "tracking")
ahead, errorAhead := checkDivergence(headRepoPath, fmt.Sprintf("%s/%s", tmpRemoteName, pr.BaseBranch), pr.HeadBranch) return &diff, err
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
} }