diff --git a/cmd/dump.go b/cmd/dump.go
index 7ff986f14eac..1a2e62576792 100644
--- a/cmd/dump.go
+++ b/cmd/dump.go
@@ -23,7 +23,6 @@ import (
 
 	"gitea.com/macaron/session"
 	archiver "github.com/mholt/archiver/v3"
-	"github.com/unknwon/com"
 	"github.com/urfave/cli"
 )
 
@@ -306,7 +305,11 @@ func runDump(ctx *cli.Context) error {
 		log.Info("Custom dir %s doesn't exist, skipped", setting.CustomPath)
 	}
 
-	if com.IsExist(setting.AppDataPath) {
+	isExist, err := util.IsExist(setting.AppDataPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", setting.AppDataPath, err)
+	}
+	if isExist {
 		log.Info("Packing data directory...%s", setting.AppDataPath)
 
 		var excludes []string
@@ -349,9 +352,15 @@ func runDump(ctx *cli.Context) error {
 	// yet or not.
 	if ctx.IsSet("skip-log") && ctx.Bool("skip-log") {
 		log.Info("Skip dumping log files")
-	} else if com.IsExist(setting.LogRootPath) {
-		if err := addRecursive(w, "log", setting.LogRootPath, verbose); err != nil {
-			fatal("Failed to include log: %v", err)
+	} else {
+		isExist, err := util.IsExist(setting.LogRootPath)
+		if err != nil {
+			log.Error("Unable to check if %s exists. Error: %v", setting.LogRootPath, err)
+		}
+		if isExist {
+			if err := addRecursive(w, "log", setting.LogRootPath, verbose); err != nil {
+				fatal("Failed to include log: %v", err)
+			}
 		}
 	}
 
diff --git a/cmd/web.go b/cmd/web.go
index 47dbc2675e24..063e41c94647 100644
--- a/cmd/web.go
+++ b/cmd/web.go
@@ -16,11 +16,11 @@ import (
 	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/routers"
 	"code.gitea.io/gitea/routers/routes"
 
 	context2 "github.com/gorilla/context"
-	"github.com/unknwon/com"
 	"github.com/urfave/cli"
 	"golang.org/x/crypto/acme/autocert"
 	ini "gopkg.in/ini.v1"
@@ -188,7 +188,11 @@ func setPort(port string) error {
 	default:
 		// Save LOCAL_ROOT_URL if port changed
 		cfg := ini.Empty()
-		if com.IsFile(setting.CustomConf) {
+		isFile, err := util.IsFile(setting.CustomConf)
+		if err != nil {
+			log.Fatal("Unable to check if %s is a file", err)
+		}
+		if isFile {
 			// Keeps custom settings if there is already something.
 			if err := cfg.Append(setting.CustomConf); err != nil {
 				return fmt.Errorf("Failed to load custom conf '%s': %v", setting.CustomConf, err)
diff --git a/contrib/environment-to-ini/environment-to-ini.go b/contrib/environment-to-ini/environment-to-ini.go
index e9dc383cb4c2..bfba2c314090 100644
--- a/contrib/environment-to-ini/environment-to-ini.go
+++ b/contrib/environment-to-ini/environment-to-ini.go
@@ -12,8 +12,8 @@ import (
 
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 
-	"github.com/unknwon/com"
 	"github.com/urfave/cli"
 	ini "gopkg.in/ini.v1"
 )
@@ -97,7 +97,11 @@ func runEnvironmentToIni(c *cli.Context) error {
 	setting.SetCustomPathAndConf(providedCustom, providedConf, providedWorkPath)
 
 	cfg := ini.Empty()
-	if com.IsFile(setting.CustomConf) {
+	isFile, err := util.IsFile(setting.CustomConf)
+	if err != nil {
+		log.Fatal("Unable to check if %s is a file. Error: %v", setting.CustomConf, err)
+	}
+	if isFile {
 		if err := cfg.Append(setting.CustomConf); err != nil {
 			log.Fatal("Failed to load custom conf '%s': %v", setting.CustomConf, err)
 		}
@@ -145,7 +149,7 @@ func runEnvironmentToIni(c *cli.Context) error {
 	if len(destination) == 0 {
 		destination = setting.CustomConf
 	}
-	err := cfg.SaveTo(destination)
+	err = cfg.SaveTo(destination)
 	if err != nil {
 		return err
 	}
diff --git a/integrations/api_repo_test.go b/integrations/api_repo_test.go
index da87db7b1b5b..25662cdda343 100644
--- a/integrations/api_repo_test.go
+++ b/integrations/api_repo_test.go
@@ -325,7 +325,7 @@ func TestAPIRepoMigrate(t *testing.T) {
 		if resp.Code == http.StatusUnprocessableEntity {
 			respJSON := map[string]string{}
 			DecodeJSON(t, resp, &respJSON)
-			if assert.Equal(t, respJSON["message"], "Remote visit addressed rate limitation.") {
+			if assert.Equal(t, "Remote visit addressed rate limitation.", respJSON["message"]) {
 				t.Log("test hit github rate limitation")
 			}
 		} else {
diff --git a/models/repo.go b/models/repo.go
index 2b53ac666cbe..7e38bbcdb7ec 100644
--- a/models/repo.go
+++ b/models/repo.go
@@ -74,7 +74,11 @@ func loadRepoConfig() {
 			log.Fatal("Failed to get %s files: %v", t, err)
 		}
 		customPath := path.Join(setting.CustomPath, "options", t)
-		if com.IsDir(customPath) {
+		isDir, err := util.IsDir(customPath)
+		if err != nil {
+			log.Fatal("Failed to get custom %s files: %v", t, err)
+		}
+		if isDir {
 			customFiles, err := com.StatDir(customPath)
 			if err != nil {
 				log.Fatal("Failed to get custom %s files: %v", t, err)
@@ -1004,7 +1008,11 @@ func isRepositoryExist(e Engine, u *User, repoName string) (bool, error) {
 		OwnerID:   u.ID,
 		LowerName: strings.ToLower(repoName),
 	})
-	return has && com.IsDir(RepoPath(u.Name, repoName)), err
+	if err != nil {
+		return false, err
+	}
+	isDir, err := util.IsDir(RepoPath(u.Name, repoName))
+	return has && isDir, err
 }
 
 // IsRepositoryExist returns true if the repository with given name under user has already existed.
@@ -1078,7 +1086,12 @@ func CheckCreateRepository(doer, u *User, name string, overwriteOrAdopt bool) er
 		return ErrRepoAlreadyExist{u.Name, name}
 	}
 
-	if !overwriteOrAdopt && com.IsExist(RepoPath(u.Name, name)) {
+	isExist, err := util.IsExist(RepoPath(u.Name, name))
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", RepoPath(u.Name, name), err)
+		return err
+	}
+	if !overwriteOrAdopt && isExist {
 		return ErrRepoFilesAlreadyExist{u.Name, name}
 	}
 	return nil
@@ -1110,7 +1123,11 @@ func GetRepoInitFile(tp, name string) ([]byte, error) {
 
 	// Use custom file when available.
 	customPath := path.Join(setting.CustomPath, relPath)
-	if com.IsFile(customPath) {
+	isFile, err := util.IsFile(customPath)
+	if err != nil {
+		log.Error("Unable to check if %s is a file. Error: %v", customPath, err)
+	}
+	if isFile {
 		return ioutil.ReadFile(customPath)
 	}
 
@@ -1156,7 +1173,12 @@ func CreateRepository(ctx DBContext, doer, u *User, repo *Repository, overwriteO
 	}
 
 	repoPath := RepoPath(u.Name, repo.Name)
-	if !overwriteOrAdopt && com.IsExist(repoPath) {
+	isExist, err := util.IsExist(repoPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
+		return err
+	}
+	if !overwriteOrAdopt && isExist {
 		log.Error("Files already exist in %s and we are not going to adopt or delete.", repoPath)
 		return ErrRepoFilesAlreadyExist{
 			Uname: u.Name,
@@ -1408,7 +1430,12 @@ func TransferOwnership(doer *User, newOwnerName string, repo *Repository) error
 
 	// Rename remote wiki repository to new path and delete local copy.
 	wikiPath := WikiPath(oldOwner.Name, repo.Name)
-	if com.IsExist(wikiPath) {
+	isExist, err := util.IsExist(wikiPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", wikiPath, err)
+		return err
+	}
+	if isExist {
 		if err = os.Rename(wikiPath, WikiPath(newOwner.Name, repo.Name)); err != nil {
 			return fmt.Errorf("rename repository wiki: %v", err)
 		}
@@ -1451,7 +1478,12 @@ func ChangeRepositoryName(doer *User, repo *Repository, newRepoName string) (err
 	}
 
 	wikiPath := repo.WikiPath()
-	if com.IsExist(wikiPath) {
+	isExist, err := util.IsExist(wikiPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", wikiPath, err)
+		return err
+	}
+	if isExist {
 		if err = os.Rename(wikiPath, WikiPath(repo.Owner.Name, newRepoName)); err != nil {
 			return fmt.Errorf("rename repository wiki: %v", err)
 		}
@@ -1528,11 +1560,16 @@ func updateRepository(e Engine, repo *Repository, visibilityChanged bool) (err e
 
 		// Create/Remove git-daemon-export-ok for git-daemon...
 		daemonExportFile := path.Join(repo.RepoPath(), `git-daemon-export-ok`)
-		if repo.IsPrivate && com.IsExist(daemonExportFile) {
+		isExist, err := util.IsExist(daemonExportFile)
+		if err != nil {
+			log.Error("Unable to check if %s exists. Error: %v", daemonExportFile, err)
+			return err
+		}
+		if repo.IsPrivate && isExist {
 			if err = util.Remove(daemonExportFile); err != nil {
 				log.Error("Failed to remove %s: %v", daemonExportFile, err)
 			}
-		} else if !repo.IsPrivate && !com.IsExist(daemonExportFile) {
+		} else if !repo.IsPrivate && !isExist {
 			if f, err := os.Create(daemonExportFile); err != nil {
 				log.Error("Failed to create %s: %v", daemonExportFile, err)
 			} else {
diff --git a/models/ssh_key.go b/models/ssh_key.go
index 29a4fd293283..f13fc61914a4 100644
--- a/models/ssh_key.go
+++ b/models/ssh_key.go
@@ -736,11 +736,18 @@ func rewriteAllPublicKeys(e Engine) error {
 		}
 	}()
 
-	if setting.SSH.AuthorizedKeysBackup && com.IsExist(fPath) {
-		bakPath := fmt.Sprintf("%s_%d.gitea_bak", fPath, time.Now().Unix())
-		if err = com.Copy(fPath, bakPath); err != nil {
+	if setting.SSH.AuthorizedKeysBackup {
+		isExist, err := util.IsExist(fPath)
+		if err != nil {
+			log.Error("Unable to check if %s exists. Error: %v", fPath, err)
 			return err
 		}
+		if isExist {
+			bakPath := fmt.Sprintf("%s_%d.gitea_bak", fPath, time.Now().Unix())
+			if err = com.Copy(fPath, bakPath); err != nil {
+				return err
+			}
+		}
 	}
 
 	if err := regeneratePublicKeys(e, t); err != nil {
@@ -765,7 +772,12 @@ func regeneratePublicKeys(e Engine, t io.StringWriter) error {
 	}
 
 	fPath := filepath.Join(setting.SSH.RootPath, "authorized_keys")
-	if com.IsExist(fPath) {
+	isExist, err := util.IsExist(fPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", fPath, err)
+		return err
+	}
+	if isExist {
 		f, err := os.Open(fPath)
 		if err != nil {
 			return err
@@ -1206,11 +1218,18 @@ func rewriteAllPrincipalKeys(e Engine) error {
 		os.Remove(tmpPath)
 	}()
 
-	if setting.SSH.AuthorizedPrincipalsBackup && com.IsExist(fPath) {
-		bakPath := fmt.Sprintf("%s_%d.gitea_bak", fPath, time.Now().Unix())
-		if err = com.Copy(fPath, bakPath); err != nil {
+	if setting.SSH.AuthorizedPrincipalsBackup {
+		isExist, err := util.IsExist(fPath)
+		if err != nil {
+			log.Error("Unable to check if %s exists. Error: %v", fPath, err)
 			return err
 		}
+		if isExist {
+			bakPath := fmt.Sprintf("%s_%d.gitea_bak", fPath, time.Now().Unix())
+			if err = com.Copy(fPath, bakPath); err != nil {
+				return err
+			}
+		}
 	}
 
 	if err := regeneratePrincipalKeys(e, t); err != nil {
@@ -1249,7 +1268,12 @@ func regeneratePrincipalKeys(e Engine, t io.StringWriter) error {
 	}
 
 	fPath := filepath.Join(setting.SSH.RootPath, authorizedPrincipalsFile)
-	if com.IsExist(fPath) {
+	isExist, err := util.IsExist(fPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", fPath, err)
+		return err
+	}
+	if isExist {
 		f, err := os.Open(fPath)
 		if err != nil {
 			return err
diff --git a/models/upload.go b/models/upload.go
index 3ad1129c257f..de2032fb720c 100644
--- a/models/upload.go
+++ b/models/upload.go
@@ -12,11 +12,11 @@ import (
 	"os"
 	"path"
 
+	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
 
 	gouuid "github.com/google/uuid"
-	"github.com/unknwon/com"
 )
 
 //  ____ ___        .__                    .___ ___________.___.__
@@ -126,7 +126,11 @@ func DeleteUploads(uploads ...*Upload) (err error) {
 
 	for _, upload := range uploads {
 		localPath := upload.LocalPath()
-		if !com.IsFile(localPath) {
+		isFile, err := util.IsFile(localPath)
+		if err != nil {
+			log.Error("Unable to check if %s is a file. Error: %v", localPath, err)
+		}
+		if !isFile {
 			continue
 		}
 
diff --git a/models/wiki.go b/models/wiki.go
index 223abf1edc55..beab48d45ada 100644
--- a/models/wiki.go
+++ b/models/wiki.go
@@ -9,7 +9,8 @@ import (
 	"path/filepath"
 	"strings"
 
-	"github.com/unknwon/com"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/util"
 )
 
 // WikiCloneLink returns clone URLs of repository wiki.
@@ -29,5 +30,9 @@ func (repo *Repository) WikiPath() string {
 
 // HasWiki returns true if repository has wiki.
 func (repo *Repository) HasWiki() bool {
-	return com.IsDir(repo.WikiPath())
+	isDir, err := util.IsDir(repo.WikiPath())
+	if err != nil {
+		log.Error("Unable to check if %s is a directory: %v", repo.WikiPath(), err)
+	}
+	return isDir
 }
diff --git a/modules/auth/repo_form.go b/modules/auth/repo_form.go
index f27812bb1b96..2d6f89b6ed75 100644
--- a/modules/auth/repo_form.go
+++ b/modules/auth/repo_form.go
@@ -10,13 +10,14 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/routers/utils"
 
 	"gitea.com/macaron/binding"
 	"gitea.com/macaron/macaron"
-	"github.com/unknwon/com"
 )
 
 // _______________________________________    _________.______________________ _______________.___.
@@ -107,8 +108,15 @@ func ParseRemoteAddr(remoteAddr, authUsername, authPassword string, user *models
 		}
 	} else if !user.CanImportLocal() {
 		return "", models.ErrInvalidCloneAddr{IsPermissionDenied: true}
-	} else if !com.IsDir(remoteAddr) {
-		return "", models.ErrInvalidCloneAddr{IsInvalidPath: true}
+	} else {
+		isDir, err := util.IsDir(remoteAddr)
+		if err != nil {
+			log.Error("Unable to check if %s is a directory: %v", remoteAddr, err)
+			return "", err
+		}
+		if !isDir {
+			return "", models.ErrInvalidCloneAddr{IsInvalidPath: true}
+		}
 	}
 
 	return remoteAddr, nil
diff --git a/modules/git/hook.go b/modules/git/hook.go
index 2de36dbdef66..c23fbf8aa1bb 100644
--- a/modules/git/hook.go
+++ b/modules/git/hook.go
@@ -13,7 +13,6 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/modules/util"
-	"github.com/unknwon/com"
 )
 
 // hookNames is a list of Git server hooks' name that are supported.
@@ -129,7 +128,12 @@ const (
 func SetUpdateHook(repoPath, content string) (err error) {
 	log("Setting update hook: %s", repoPath)
 	hookPath := path.Join(repoPath, HookPathUpdate)
-	if com.IsExist(hookPath) {
+	isExist, err := util.IsExist(hookPath)
+	if err != nil {
+		log("Unable to check if %s exists. Error: %v", hookPath, err)
+		return err
+	}
+	if isExist {
 		err = util.Remove(hookPath)
 	} else {
 		err = os.MkdirAll(path.Dir(hookPath), os.ModePerm)
diff --git a/modules/options/dynamic.go b/modules/options/dynamic.go
index 20dde11dc3e9..060ca12bb00d 100644
--- a/modules/options/dynamic.go
+++ b/modules/options/dynamic.go
@@ -11,7 +11,9 @@ import (
 	"io/ioutil"
 	"path"
 
+	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 
 	"github.com/unknwon/com"
 )
@@ -32,7 +34,11 @@ func Dir(name string) ([]string, error) {
 
 	customDir := path.Join(setting.CustomPath, "options", name)
 
-	if com.IsDir(customDir) {
+	isDir, err := util.IsDir(customDir)
+	if err != nil {
+		return []string{}, fmt.Errorf("Unabe to check if custom directory %s is a directory. %v", customDir, err)
+	}
+	if isDir {
 		files, err := com.StatDir(customDir, true)
 
 		if err != nil {
@@ -44,7 +50,11 @@ func Dir(name string) ([]string, error) {
 
 	staticDir := path.Join(setting.StaticRootPath, "options", name)
 
-	if com.IsDir(staticDir) {
+	isDir, err = util.IsDir(staticDir)
+	if err != nil {
+		return []string{}, fmt.Errorf("Unabe to check if static directory %s is a directory. %v", staticDir, err)
+	}
+	if isDir {
 		files, err := com.StatDir(staticDir, true)
 
 		if err != nil {
@@ -86,13 +96,21 @@ func Labels(name string) ([]byte, error) {
 func fileFromDir(name string) ([]byte, error) {
 	customPath := path.Join(setting.CustomPath, "options", name)
 
-	if com.IsFile(customPath) {
+	isFile, err := util.IsFile(customPath)
+	if err != nil {
+		log.Error("Unable to check if %s is a file. Error: %v", customPath, err)
+	}
+	if isFile {
 		return ioutil.ReadFile(customPath)
 	}
 
 	staticPath := path.Join(setting.StaticRootPath, "options", name)
 
-	if com.IsFile(staticPath) {
+	isFile, err = util.IsFile(staticPath)
+	if err != nil {
+		log.Error("Unable to check if %s is a file. Error: %v", staticPath, err)
+	}
+	if isFile {
 		return ioutil.ReadFile(staticPath)
 	}
 
diff --git a/modules/options/static.go b/modules/options/static.go
index 39f56f42f478..ff1e6b233234 100644
--- a/modules/options/static.go
+++ b/modules/options/static.go
@@ -11,7 +11,9 @@ import (
 	"io/ioutil"
 	"path"
 
+	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 
 	"github.com/unknwon/com"
 )
@@ -31,8 +33,11 @@ func Dir(name string) ([]string, error) {
 	)
 
 	customDir := path.Join(setting.CustomPath, "options", name)
-
-	if com.IsDir(customDir) {
+	isDir, err := util.IsDir(customDir)
+	if err != nil {
+		return []string{}, fmt.Errorf("Failed to check if custom directory %s is a directory. %v", err)
+	}
+	if isDir {
 		files, err := com.StatDir(customDir, true)
 
 		if err != nil {
@@ -100,7 +105,11 @@ func Labels(name string) ([]byte, error) {
 func fileFromDir(name string) ([]byte, error) {
 	customPath := path.Join(setting.CustomPath, "options", name)
 
-	if com.IsFile(customPath) {
+	isFile, err := util.IsFile(customPath)
+	if err != nil {
+		log.Error("Unable to check if %s is a file. Error: %v", customPath, err)
+	}
+	if isFile {
 		return ioutil.ReadFile(customPath)
 	}
 
diff --git a/modules/repository/adopt.go b/modules/repository/adopt.go
index 22cd6dd91f7f..030211963056 100644
--- a/modules/repository/adopt.go
+++ b/modules/repository/adopt.go
@@ -16,7 +16,6 @@ import (
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
 	"github.com/gobwas/glob"
-	"github.com/unknwon/com"
 )
 
 // AdoptRepository adopts a repository for the user/organization.
@@ -49,7 +48,12 @@ func AdoptRepository(doer, u *models.User, opts models.CreateRepoOptions) (*mode
 
 	if err := models.WithTx(func(ctx models.DBContext) error {
 		repoPath := models.RepoPath(u.Name, repo.Name)
-		if !com.IsExist(repoPath) {
+		isExist, err := util.IsExist(repoPath)
+		if err != nil {
+			log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
+			return err
+		}
+		if !isExist {
 			return models.ErrRepoNotExist{
 				OwnerName: u.Name,
 				Name:      repo.Name,
@@ -91,7 +95,12 @@ func DeleteUnadoptedRepository(doer, u *models.User, repoName string) error {
 	}
 
 	repoPath := models.RepoPath(u.Name, repoName)
-	if !com.IsExist(repoPath) {
+	isExist, err := util.IsExist(repoPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
+		return err
+	}
+	if !isExist {
 		return models.ErrRepoNotExist{
 			OwnerName: u.Name,
 			Name:      repoName,
diff --git a/modules/repository/check.go b/modules/repository/check.go
index 274576c34887..d13ddbb0b017 100644
--- a/modules/repository/check.go
+++ b/modules/repository/check.go
@@ -13,8 +13,8 @@ import (
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/util"
 
-	"github.com/unknwon/com"
 	"xorm.io/builder"
 )
 
@@ -114,7 +114,11 @@ func gatherMissingRepoRecords(ctx context.Context) ([]*models.Repository, error)
 				return models.ErrCancelledf("during gathering missing repo records before checking %s", repo.FullName())
 			default:
 			}
-			if !com.IsDir(repo.RepoPath()) {
+			isDir, err := util.IsDir(repo.RepoPath())
+			if err != nil {
+				return fmt.Errorf("Unable to check dir for %s. %w", repo.FullName(), err)
+			}
+			if !isDir {
 				repos = append(repos, repo)
 			}
 			return nil
diff --git a/modules/repository/create.go b/modules/repository/create.go
index 1408637815d3..1f7145ee2a58 100644
--- a/modules/repository/create.go
+++ b/modules/repository/create.go
@@ -13,8 +13,6 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
-
-	"github.com/unknwon/com"
 )
 
 // CreateRepository creates a repository for the user/organization.
@@ -58,7 +56,12 @@ func CreateRepository(doer, u *models.User, opts models.CreateRepoOptions) (*mod
 		}
 
 		repoPath := models.RepoPath(u.Name, repo.Name)
-		if com.IsExist(repoPath) {
+		isExist, err := util.IsExist(repoPath)
+		if err != nil {
+			log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
+			return err
+		}
+		if isExist {
 			// repo already exists - We have two or three options.
 			// 1. We fail stating that the directory exists
 			// 2. We create the db repository to go with this data and adopt the git repo
diff --git a/modules/repository/generate.go b/modules/repository/generate.go
index 5d1ef72b6c04..0142d689d160 100644
--- a/modules/repository/generate.go
+++ b/modules/repository/generate.go
@@ -19,7 +19,6 @@ import (
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/huandu/xstrings"
-	"github.com/unknwon/com"
 )
 
 type transformer struct {
@@ -252,7 +251,12 @@ func GenerateRepository(ctx models.DBContext, doer, owner *models.User, template
 	}
 
 	repoPath := generateRepo.RepoPath()
-	if com.IsExist(repoPath) {
+	isExist, err := util.IsExist(repoPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
+		return nil, err
+	}
+	if isExist {
 		return nil, models.ErrRepoFilesAlreadyExist{
 			Uname: generateRepo.OwnerName,
 			Name:  generateRepo.Name,
diff --git a/modules/repository/hooks.go b/modules/repository/hooks.go
index faf9c98f8ae8..aba5db6719b2 100644
--- a/modules/repository/hooks.go
+++ b/modules/repository/hooks.go
@@ -15,7 +15,6 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
-	"github.com/unknwon/com"
 
 	"xorm.io/builder"
 )
@@ -112,15 +111,27 @@ func CheckDelegateHooks(repoPath string) ([]string, error) {
 		newHookPath := filepath.Join(hookDir, hookName+".d", "gitea")
 
 		cont := false
-		if !com.IsExist(oldHookPath) {
+		isExist, err := util.IsExist(oldHookPath)
+		if err != nil {
+			results = append(results, fmt.Sprintf("unable to check if %s exists. Error: %v", oldHookPath, err))
+		}
+		if err == nil && !isExist {
 			results = append(results, fmt.Sprintf("old hook file %s does not exist", oldHookPath))
 			cont = true
 		}
-		if !com.IsExist(oldHookPath + ".d") {
+		isExist, err = util.IsExist(oldHookPath + ".d")
+		if err != nil {
+			results = append(results, fmt.Sprintf("unable to check if %s exists. Error: %v", oldHookPath+".d", err))
+		}
+		if err == nil && !isExist {
 			results = append(results, fmt.Sprintf("hooks directory %s does not exist", oldHookPath+".d"))
 			cont = true
 		}
-		if !com.IsExist(newHookPath) {
+		isExist, err = util.IsExist(newHookPath)
+		if err != nil {
+			results = append(results, fmt.Sprintf("unable to check if %s exists. Error: %v", newHookPath, err))
+		}
+		if err == nil && !isExist {
 			results = append(results, fmt.Sprintf("new hook file %s does not exist", newHookPath))
 			cont = true
 		}
diff --git a/modules/repository/init.go b/modules/repository/init.go
index 569069ee1fcc..37dc69a0a868 100644
--- a/modules/repository/init.go
+++ b/modules/repository/init.go
@@ -175,7 +175,12 @@ func initRepoCommit(tmpPath string, repo *models.Repository, u *models.User, def
 func checkInitRepository(owner, name string) (err error) {
 	// Somehow the directory could exist.
 	repoPath := models.RepoPath(owner, name)
-	if com.IsExist(repoPath) {
+	isExist, err := util.IsExist(repoPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
+		return err
+	}
+	if isExist {
 		return models.ErrRepoFilesAlreadyExist{
 			Uname: owner,
 			Name:  name,
@@ -192,7 +197,12 @@ func checkInitRepository(owner, name string) (err error) {
 }
 
 func adoptRepository(ctx models.DBContext, repoPath string, u *models.User, repo *models.Repository, opts models.CreateRepoOptions) (err error) {
-	if !com.IsExist(repoPath) {
+	isExist, err := util.IsExist(repoPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
+		return err
+	}
+	if !isExist {
 		return fmt.Errorf("adoptRepository: path does not already exist: %s", repoPath)
 	}
 
diff --git a/modules/setting/lfs.go b/modules/setting/lfs.go
index 5af80c2ab16f..ab475bbeb4b3 100644
--- a/modules/setting/lfs.go
+++ b/modules/setting/lfs.go
@@ -13,8 +13,8 @@ import (
 	"code.gitea.io/gitea/modules/generate"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/util"
 
-	"github.com/unknwon/com"
 	ini "gopkg.in/ini.v1"
 )
 
@@ -65,7 +65,11 @@ func newLFSService() {
 
 			// Save secret
 			cfg := ini.Empty()
-			if com.IsFile(CustomConf) {
+			isFile, err := util.IsFile(CustomConf)
+			if err != nil {
+				log.Error("Unable to check if %s is a file. Error: %v", CustomConf, err)
+			}
+			if isFile {
 				// Keeps custom settings if there is already something.
 				if err := cfg.Append(CustomConf); err != nil {
 					log.Error("Failed to load custom conf '%s': %v", CustomConf, err)
diff --git a/modules/setting/setting.go b/modules/setting/setting.go
index 708dc282337d..79e7751905b7 100644
--- a/modules/setting/setting.go
+++ b/modules/setting/setting.go
@@ -25,6 +25,7 @@ import (
 	"code.gitea.io/gitea/modules/generate"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/user"
+	"code.gitea.io/gitea/modules/util"
 
 	shellquote "github.com/kballard/go-shellquote"
 	"github.com/unknwon/com"
@@ -498,7 +499,11 @@ func NewContext() {
 		createPIDFile(PIDFile)
 	}
 
-	if com.IsFile(CustomConf) {
+	isFile, err := util.IsFile(CustomConf)
+	if err != nil {
+		log.Error("Unable to check if %s is a file. Error: %v", CustomConf, err)
+	}
+	if isFile {
 		if err := Cfg.Append(CustomConf); err != nil {
 			log.Fatal("Failed to load custom conf '%s': %v", CustomConf, err)
 		}
@@ -739,7 +744,11 @@ func NewContext() {
 				return
 			}
 			cfg := ini.Empty()
-			if com.IsFile(CustomConf) {
+			isFile, err := util.IsFile(CustomConf)
+			if err != nil {
+				log.Error("Unable to check if %s is a file. Error: %v", CustomConf, err)
+			}
+			if isFile {
 				if err := cfg.Append(CustomConf); err != nil {
 					log.Error("failed to load custom conf %s: %v", CustomConf, err)
 					return
@@ -908,7 +917,10 @@ func NewContext() {
 	UI.SearchRepoDescription = Cfg.Section("ui").Key("SEARCH_REPO_DESCRIPTION").MustBool(true)
 	UI.UseServiceWorker = Cfg.Section("ui").Key("USE_SERVICE_WORKER").MustBool(true)
 
-	HasRobotsTxt = com.IsFile(path.Join(CustomPath, "robots.txt"))
+	HasRobotsTxt, err = util.IsFile(path.Join(CustomPath, "robots.txt"))
+	if err != nil {
+		log.Error("Unable to check if %s is a file. Error: %v", path.Join(CustomPath, "robots.txt"), err)
+	}
 
 	newMarkup()
 
@@ -1005,7 +1017,11 @@ func loadOrGenerateInternalToken(sec *ini.Section) string {
 
 		// Save secret
 		cfgSave := ini.Empty()
-		if com.IsFile(CustomConf) {
+		isFile, err := util.IsFile(CustomConf)
+		if err != nil {
+			log.Error("Unable to check if %s is a file. Error: %v", CustomConf, err)
+		}
+		if isFile {
 			// Keeps custom settings if there is already something.
 			if err := cfgSave.Append(CustomConf); err != nil {
 				log.Error("Failed to load custom conf '%s': %v", CustomConf, err)
diff --git a/modules/ssh/ssh.go b/modules/ssh/ssh.go
index 7a449dd41b0a..761164caa017 100644
--- a/modules/ssh/ssh.go
+++ b/modules/ssh/ssh.go
@@ -22,6 +22,7 @@ import (
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 
 	"github.com/gliderlabs/ssh"
 	"github.com/unknwon/com"
@@ -211,7 +212,11 @@ func Listen(host string, port int, ciphers []string, keyExchanges []string, macs
 	}
 
 	keyPath := filepath.Join(setting.AppDataPath, "ssh/gogs.rsa")
-	if !com.IsExist(keyPath) {
+	isExist, err := util.IsExist(keyPath)
+	if err != nil {
+		log.Fatal("Unable to check if %s exists. Error: %v", keyPath, err)
+	}
+	if !isExist {
 		filePath := filepath.Dir(keyPath)
 
 		if err := os.MkdirAll(filePath, os.ModePerm); err != nil {
@@ -225,7 +230,7 @@ func Listen(host string, port int, ciphers []string, keyExchanges []string, macs
 		log.Trace("New private key is generated: %s", keyPath)
 	}
 
-	err := srv.SetOption(ssh.HostKeyFile(keyPath))
+	err = srv.SetOption(ssh.HostKeyFile(keyPath))
 	if err != nil {
 		log.Error("Failed to set Host Key. %s", err)
 	}
diff --git a/modules/templates/dynamic.go b/modules/templates/dynamic.go
index bd1c4d06c586..5eda9480348e 100644
--- a/modules/templates/dynamic.go
+++ b/modules/templates/dynamic.go
@@ -15,6 +15,7 @@ import (
 
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 
 	"gitea.com/macaron/macaron"
 	"github.com/unknwon/com"
@@ -59,7 +60,11 @@ func Mailer() (*texttmpl.Template, *template.Template) {
 
 	staticDir := path.Join(setting.StaticRootPath, "templates", "mail")
 
-	if com.IsDir(staticDir) {
+	isDir, err := util.IsDir(staticDir)
+	if err != nil {
+		log.Warn("Unable to check if templates dir %s is a directory. Error: %v", staticDir, err)
+	}
+	if isDir {
 		files, err := com.StatDir(staticDir)
 
 		if err != nil {
@@ -84,7 +89,11 @@ func Mailer() (*texttmpl.Template, *template.Template) {
 
 	customDir := path.Join(setting.CustomPath, "templates", "mail")
 
-	if com.IsDir(customDir) {
+	isDir, err = util.IsDir(customDir)
+	if err != nil {
+		log.Warn("Unable to check if templates dir %s is a directory. Error: %v", customDir, err)
+	}
+	if isDir {
 		files, err := com.StatDir(customDir)
 
 		if err != nil {
diff --git a/modules/templates/static.go b/modules/templates/static.go
index a3aff5e567bd..fd8e79a783be 100644
--- a/modules/templates/static.go
+++ b/modules/templates/static.go
@@ -18,6 +18,7 @@ import (
 
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 
 	"gitea.com/macaron/macaron"
 	"github.com/unknwon/com"
@@ -77,8 +78,11 @@ func NewTemplateFileSystem() templateFileSystem {
 	}
 
 	customDir := path.Join(setting.CustomPath, "templates")
-
-	if com.IsDir(customDir) {
+	isDir, err := util.IsDir(customDir)
+	if err != nil {
+		log.Warn("Unable to check if templates dir %s is a directory. Error: %v", customDir, err)
+	}
+	if isDir {
 		files, err := com.StatDir(customDir)
 
 		if err != nil {
@@ -170,8 +174,11 @@ func Mailer() (*texttmpl.Template, *template.Template) {
 	}
 
 	customDir := path.Join(setting.CustomPath, "templates", "mail")
-
-	if com.IsDir(customDir) {
+	isDir, err := util.IsDir(customDir)
+	if err != nil {
+		log.Warn("Failed to check if custom directory %s is a directory. %v", err)
+	}
+	if isDir {
 		files, err := com.StatDir(customDir)
 
 		if err != nil {
diff --git a/modules/util/path.go b/modules/util/path.go
index 2b198eb6dc6e..fbcefb83b6f7 100644
--- a/modules/util/path.go
+++ b/modules/util/path.go
@@ -31,3 +31,42 @@ func GetDirectorySize(path string) (int64, error) {
 	})
 	return size, err
 }
+
+// IsDir returns true if given path is a directory,
+// or returns false when it's a file or does not exist.
+func IsDir(dir string) (bool, error) {
+	f, err := os.Stat(dir)
+	if err == nil {
+		return f.IsDir(), nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}
+
+// IsFile returns true if given path is a file,
+// or returns false when it's a directory or does not exist.
+func IsFile(filePath string) (bool, error) {
+	f, err := os.Stat(filePath)
+	if err == nil {
+		return !f.IsDir(), nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}
+
+// IsExist checks whether a file or directory exists.
+// It returns false when the file or directory does not exist.
+func IsExist(path string) (bool, error) {
+	_, err := os.Stat(path)
+	if err == nil || os.IsExist(err) {
+		return true, nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}
diff --git a/routers/admin/repos.go b/routers/admin/repos.go
index 10abaf9547ad..54b6c8e7c6fb 100644
--- a/routers/admin/repos.go
+++ b/routers/admin/repos.go
@@ -13,9 +13,9 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/repository"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/routers"
 	repo_service "code.gitea.io/gitea/services/repository"
-	"github.com/unknwon/com"
 )
 
 const (
@@ -120,10 +120,17 @@ func AdoptOrDeleteRepository(ctx *context.Context) {
 	repoName := dirSplit[1]
 
 	// check not a repo
-	if has, err := models.IsRepositoryExist(ctxUser, repoName); err != nil {
+	has, err := models.IsRepositoryExist(ctxUser, repoName)
+	if err != nil {
 		ctx.ServerError("IsRepositoryExist", err)
 		return
-	} else if has || !com.IsDir(models.RepoPath(ctxUser.Name, repoName)) {
+	}
+	isDir, err := util.IsDir(models.RepoPath(ctxUser.Name, repoName))
+	if err != nil {
+		ctx.ServerError("IsDir", err)
+		return
+	}
+	if has || !isDir {
 		// Fallthrough to failure mode
 	} else if action == "adopt" {
 		if _, err := repository.AdoptRepository(ctx.User, ctxUser, models.CreateRepoOptions{
diff --git a/routers/api/v1/admin/adopt.go b/routers/api/v1/admin/adopt.go
index 1a7a62a55cf0..fdef94e6c843 100644
--- a/routers/api/v1/admin/adopt.go
+++ b/routers/api/v1/admin/adopt.go
@@ -11,8 +11,8 @@ import (
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/repository"
+	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/routers/api/v1/utils"
-	"github.com/unknwon/com"
 )
 
 // ListUnadoptedRepositories lists the unadopted repositories that match the provided names
@@ -92,10 +92,17 @@ func AdoptRepository(ctx *context.APIContext) {
 	}
 
 	// check not a repo
-	if has, err := models.IsRepositoryExist(ctxUser, repoName); err != nil {
+	has, err := models.IsRepositoryExist(ctxUser, repoName)
+	if err != nil {
 		ctx.InternalServerError(err)
 		return
-	} else if has || !com.IsDir(models.RepoPath(ctxUser.Name, repoName)) {
+	}
+	isDir, err := util.IsDir(models.RepoPath(ctxUser.Name, repoName))
+	if err != nil {
+		ctx.InternalServerError(err)
+		return
+	}
+	if has || !isDir {
 		ctx.NotFound()
 		return
 	}
@@ -147,10 +154,17 @@ func DeleteUnadoptedRepository(ctx *context.APIContext) {
 	}
 
 	// check not a repo
-	if has, err := models.IsRepositoryExist(ctxUser, repoName); err != nil {
+	has, err := models.IsRepositoryExist(ctxUser, repoName)
+	if err != nil {
 		ctx.InternalServerError(err)
 		return
-	} else if has || !com.IsDir(models.RepoPath(ctxUser.Name, repoName)) {
+	}
+	isDir, err := util.IsDir(models.RepoPath(ctxUser.Name, repoName))
+	if err != nil {
+		ctx.InternalServerError(err)
+		return
+	}
+	if has || !isDir {
 		ctx.NotFound()
 		return
 	}
diff --git a/routers/install.go b/routers/install.go
index 4dd934aa04f9..88786efb9586 100644
--- a/routers/install.go
+++ b/routers/install.go
@@ -20,6 +20,7 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/user"
+	"code.gitea.io/gitea/modules/util"
 
 	"github.com/unknwon/com"
 	"gopkg.in/ini.v1"
@@ -260,7 +261,11 @@ func InstallPost(ctx *context.Context, form auth.InstallForm) {
 
 	// Save settings.
 	cfg := ini.Empty()
-	if com.IsFile(setting.CustomConf) {
+	isFile, err := util.IsFile(setting.CustomConf)
+	if err != nil {
+		log.Error("Unable to check if %s is a file. Error: %v", setting.CustomConf, err)
+	}
+	if isFile {
 		// Keeps custom settings if there is already something.
 		if err = cfg.Append(setting.CustomConf); err != nil {
 			log.Error("Failed to load custom conf '%s': %v", setting.CustomConf, err)
diff --git a/routers/user/setting/adopt.go b/routers/user/setting/adopt.go
index 6ff07d6daa91..b2d918784f59 100644
--- a/routers/user/setting/adopt.go
+++ b/routers/user/setting/adopt.go
@@ -11,7 +11,7 @@ import (
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/repository"
 	"code.gitea.io/gitea/modules/setting"
-	"github.com/unknwon/com"
+	"code.gitea.io/gitea/modules/util"
 )
 
 // AdoptOrDeleteRepository adopts or deletes a repository
@@ -30,10 +30,18 @@ func AdoptOrDeleteRepository(ctx *context.Context) {
 	root := filepath.Join(models.UserPath(ctxUser.LowerName))
 
 	// check not a repo
-	if has, err := models.IsRepositoryExist(ctxUser, dir); err != nil {
+	has, err := models.IsRepositoryExist(ctxUser, dir)
+	if err != nil {
 		ctx.ServerError("IsRepositoryExist", err)
 		return
-	} else if has || !com.IsDir(filepath.Join(root, dir+".git")) {
+	}
+
+	isDir, err := util.IsDir(filepath.Join(root, dir+".git"))
+	if err != nil {
+		ctx.ServerError("IsDir", err)
+		return
+	}
+	if has || !isDir {
 		// Fallthrough to failure mode
 	} else if action == "adopt" && allowAdopt {
 		if _, err := repository.AdoptRepository(ctxUser, ctxUser, models.CreateRepoOptions{
diff --git a/services/archiver/archiver.go b/services/archiver/archiver.go
index 4dd84524ca93..359fc8b627d9 100644
--- a/services/archiver/archiver.go
+++ b/services/archiver/archiver.go
@@ -21,8 +21,7 @@ import (
 	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
-
-	"github.com/unknwon/com"
+	"code.gitea.io/gitea/modules/util"
 )
 
 // ArchiveRequest defines the parameters of an archive request, which notably
@@ -138,7 +137,12 @@ func DeriveRequestFrom(ctx *context.Context, uri string) *ArchiveRequest {
 	}
 
 	r.refName = strings.TrimSuffix(r.uri, r.ext)
-	if !com.IsDir(r.archivePath) {
+	isDir, err := util.IsDir(r.archivePath)
+	if err != nil {
+		ctx.ServerError("Download -> util.IsDir(archivePath)", err)
+		return nil
+	}
+	if !isDir {
 		if err := os.MkdirAll(r.archivePath, os.ModePerm); err != nil {
 			ctx.ServerError("Download -> os.MkdirAll(archivePath)", err)
 			return nil
@@ -146,9 +150,6 @@ func DeriveRequestFrom(ctx *context.Context, uri string) *ArchiveRequest {
 	}
 
 	// Get corresponding commit.
-	var (
-		err error
-	)
 	if r.repo.IsBranchExist(r.refName) {
 		r.commit, err = r.repo.GetBranchCommit(r.refName)
 		if err != nil {
@@ -179,7 +180,11 @@ func DeriveRequestFrom(ctx *context.Context, uri string) *ArchiveRequest {
 	}
 
 	r.archivePath = path.Join(r.archivePath, base.ShortSha(r.commit.ID.String())+r.ext)
-	r.archiveComplete = com.IsFile(r.archivePath)
+	r.archiveComplete, err = util.IsFile(r.archivePath)
+	if err != nil {
+		ctx.ServerError("util.IsFile", err)
+		return nil
+	}
 	return r
 }
 
@@ -198,7 +203,11 @@ func doArchive(r *ArchiveRequest) {
 	// race conditions and difficulties in locking.  Do one last check that
 	// the archive we're referring to doesn't already exist.  If it does exist,
 	// then just mark the request as complete and move on.
-	if com.IsFile(r.archivePath) {
+	isFile, err := util.IsFile(r.archivePath)
+	if err != nil {
+		log.Error("Unable to check if %s util.IsFile: %v. Will ignore and recreate.", r.archivePath, err)
+	}
+	if isFile {
 		r.archiveComplete = true
 		return
 	}