chore: enable several rules from go-critic

.golangci.yml

@@ -3,6 +3,7 @@ linters:
   enable:
     - errorlint
     - forbidigo
+    - gocritic
     - godot
     - misspell
     - revive
@@ -12,6 +13,20 @@ linters:
       forbid:
         - pattern: ^fmt\.Print.*$
           msg: Do not commit print statements.
+    gocritic:
+      enable-all: true
+      disabled-checks:
+        - commentFormatting
+        - commentedOutCode
+        - deferInLoop
+        - filepathJoin
+        - hugeParam
+        - importShadow
+        - paramTypeCombine
+        - rangeValCopy
+        - tooManyResultsChecker
+        - unnamedResult
+        - whyNoLint
     godot:
       exclude:
         # Ignore "See: URL".

arp.go

@@ -73,15 +73,16 @@ func parseARPEntries(data []byte) ([]ARPEntry, error) {
 		columns := strings.Fields(line)
 		width := len(columns)
 
-		if width == expectedHeaderWidth || width == 0 {
+		switch width {
+		case expectedHeaderWidth, 0:
 			continue
-		} else if width == expectedDataWidth {
+		case expectedDataWidth:
 			entry, err := parseARPEntry(columns)
 			if err != nil {
 				return []ARPEntry{}, fmt.Errorf("%w: Failed to parse ARP entry: %v: %w", ErrFileParse, entry, err)
 			}
 			entries = append(entries, entry)
-		} else {
+		default:
 			return []ARPEntry{}, fmt.Errorf("%w: %d columns found, but expected %d: %w", ErrFileParse, width, expectedDataWidth, err)
 		}
 

bcache/get.go

@@ -111,7 +111,7 @@ func parsePseudoFloat(str string) (float64, error) {
 	// v4.12-rc3).
 
 	// Restore the proper order:
-	fracPart = fracPart / 10.24
+	fracPart /= 10.24
 	return intPart + fracPart, nil
 }
 

buddyinfo.go

@@ -64,10 +64,8 @@ func parseBuddyInfo(r io.Reader) ([]BuddyInfo, error) {
 
 		if bucketCount == -1 {
 			bucketCount = arraySize
-		} else {
-			if bucketCount != arraySize {
-				return nil, fmt.Errorf("%w: mismatch in number of buddyinfo buckets, previous count %d, new count %d", ErrFileParse, bucketCount, arraySize)
-			}
+		} else if bucketCount != arraySize {
+			return nil, fmt.Errorf("%w: mismatch in number of buddyinfo buckets, previous count %d, new count %d", ErrFileParse, bucketCount, arraySize)
 		}
 
 		sizes := make([]float64, arraySize)

fscache.go

@@ -388,20 +388,21 @@ func parseFscacheinfo(r io.Reader) (*Fscacheinfo, error) {
 				}
 			}
 		case "CacheOp:":
-			if strings.Split(fields[1], "=")[0] == "alo" {
+			switch strings.Split(fields[1], "=")[0] {
+			case "alo":
 				err := setFSCacheFields(fields[1:], &m.CacheopAllocationsinProgress, &m.CacheopLookupObjectInProgress,
 					&m.CacheopLookupCompleteInPorgress, &m.CacheopGrabObjectInProgress)
 				if err != nil {
 					return &m, err
 				}
-			} else if strings.Split(fields[1], "=")[0] == "inv" {
+			case "inv":
 				err := setFSCacheFields(fields[1:], &m.CacheopInvalidations, &m.CacheopUpdateObjectInProgress,
 					&m.CacheopDropObjectInProgress, &m.CacheopPutObjectInProgress, &m.CacheopAttributeChangeInProgress,
 					&m.CacheopSyncCacheInProgress)
 				if err != nil {
 					return &m, err
 				}
-			} else {
+			default:
 				err := setFSCacheFields(fields[1:], &m.CacheopReadOrAllocPageInProgress, &m.CacheopReadOrAllocPagesInProgress,
 					&m.CacheopAllocatePageInProgress, &m.CacheopAllocatePagesInProgress, &m.CacheopWritePagesInProgress,
 					&m.CacheopUncachePagesInProgress, &m.CacheopDissociatePagesInProgress)

iscsi/get.go

@@ -208,7 +208,7 @@ func (fs FS) GetRBDMatch(rbdNumber string, poolImage string) (*RBD, error) {
 		}
 		systemImage = strings.TrimSpace(string(bSystemImage))
 
-		if strings.Compare(strconv.FormatInt(int64(systemRbdNumber), 10), rbdNumber) == 0 &&
+		if strconv.FormatInt(int64(systemRbdNumber), 10) == rbdNumber &&
 			matchPoolImage(systemPool, systemImage, poolImage) {
 			rbd.Pool = systemPool
 			rbd.Image = systemImage
@@ -241,5 +241,5 @@ func (fs FS) GetRDMCPPath(rdmcpNumber string, objectName string) (*RDMCP, error)
 
 func matchPoolImage(pool string, image string, matchPoolImage string) (isEqual bool) {
 	var poolImage = fmt.Sprintf("%s-%s", pool, image)
-	return strings.Compare(poolImage, matchPoolImage) == 0
+	return poolImage == matchPoolImage
 }

mdstat.go

@@ -129,13 +129,14 @@ func parseMDStat(mdStatData []byte) ([]MDStat, error) {
 
 		// Append recovery and resyncing state info.
 		if recovering || resyncing || checking || reshaping {
-			if recovering {
+			switch {
+			case recovering:
 				state = "recovering"
-			} else if reshaping {
+			case reshaping:
 				state = "reshaping"
-			} else if checking {
+			case checking:
 				state = "checking"
-			} else {
+			default:
 				state = "resyncing"
 			}
 

proc_cgroups.go

@@ -40,13 +40,13 @@ type CgroupSummary struct {
 
 // parseCgroupSummary parses each line of the /proc/cgroup file
 // Line format is `subsys_name	hierarchy	num_cgroups	enabled`.
-func parseCgroupSummaryString(CgroupSummaryStr string) (*CgroupSummary, error) {
+func parseCgroupSummaryString(cgroupSummaryStr string) (*CgroupSummary, error) {
 	var err error
 
-	fields := strings.Fields(CgroupSummaryStr)
+	fields := strings.Fields(cgroupSummaryStr)
 	// require at least 4 fields
 	if len(fields) < 4 {
-		return nil, fmt.Errorf("%w: 4+ fields required, found %d fields in cgroup info string: %s", ErrFileParse, len(fields), CgroupSummaryStr)
+		return nil, fmt.Errorf("%w: 4+ fields required, found %d fields in cgroup info string: %s", ErrFileParse, len(fields), cgroupSummaryStr)
 	}
 
 	CgroupSummary := &CgroupSummary{

proc_fdinfo.go

@@ -60,15 +60,16 @@ func (p Proc) FDInfo(fd string) (*ProcFDInfo, error) {
 	scanner := bufio.NewScanner(bytes.NewReader(data))
 	for scanner.Scan() {
 		text = scanner.Text()
-		if rPos.MatchString(text) {
+		switch {
+		case rPos.MatchString(text):
 			pos = rPos.FindStringSubmatch(text)[1]
-		} else if rFlags.MatchString(text) {
+		case rFlags.MatchString(text):
 			flags = rFlags.FindStringSubmatch(text)[1]
-		} else if rMntID.MatchString(text) {
+		case rMntID.MatchString(text):
 			mntid = rMntID.FindStringSubmatch(text)[1]
-		} else if rIno.MatchString(text) {
+		case rIno.MatchString(text):
 			ino = rIno.FindStringSubmatch(text)[1]
-		} else if rInotify.MatchString(text) {
+		case rInotify.MatchString(text):
 			newInotify, err := parseInotifyInfo(text)
 			if err != nil {
 				return nil, err

proc_limits.go

@@ -74,7 +74,7 @@ const (
 )
 
 var (
-	limitsMatch = regexp.MustCompile(`(Max \w+\s{0,1}?\w*\s{0,1}\w*)\s{2,}(\w+)\s+(\w+)`)
+	limitsMatch = regexp.MustCompile(`(Max \w+\s??\w*\s?\w*)\s{2,}(\w+)\s+(\w+)`)
 )
 
 // NewLimits returns the current soft limits of the process.

sysfs/class_sas_device.go

@@ -42,7 +42,7 @@ type SASDeviceClass map[string]*SASDevice
 
 var (
 	sasTargetDeviceRegexp    = regexp.MustCompile(`^target[0-9:]+$`)
-	sasTargetSubDeviceRegexp = regexp.MustCompile(`[0-9]+:.*`)
+	sasTargetSubDeviceRegexp = regexp.MustCompile(`\d+:.*`)
 )
 
 // sasDeviceClasses reads all of the SAS devices from a specific set

sysfs/class_scsitape.go

@@ -59,10 +59,10 @@ func (fs FS) SCSITapeClass() (SCSITapeClass, error) {
 	// There are n?st[0-9]+[a-b]? variants depending on device features.
 	// n/2 is probably overestimated but never underestimated
 	stc := make(SCSITapeClass, len(dirs)/2)
-	validDevice := regexp.MustCompile(`^st[0-9]+$`)
+	validDevice := regexp.MustCompile(`^st\d+$`)
 
 	for _, d := range dirs {
-		if !validDevice.Match([]byte(d.Name())) {
+		if !validDevice.MatchString(d.Name()) {
 			continue
 		}
 		tape, err := fs.parseSCSITape(d.Name())

sysfs/class_thermal.go

@@ -86,11 +86,12 @@ func parseClassThermalZone(zone string) (ClassThermalZoneStats, error) {
 
 	var zonePassive *uint64
 	passive, err := util.SysReadUintFromFile(filepath.Join(zone, "passive"))
-	if os.IsNotExist(err) || os.IsPermission(err) {
+	switch {
+	case os.IsNotExist(err), os.IsPermission(err):
 		zonePassive = nil
-	} else if err != nil {
+	case err != nil:
 		return ClassThermalZoneStats{}, err
-	} else {
+	default:
 		zonePassive = &passive
 	}
 

sysfs/net_class.go

@@ -125,15 +125,16 @@ func (fs FS) NetClass() (NetClass, error) {
 func canIgnoreError(err error) bool {
 	var errno syscall.Errno
 
-	if os.IsNotExist(err) {
+	switch {
+	case os.IsNotExist(err):
 		return true
-	} else if os.IsPermission(err) {
+	case os.IsPermission(err):
 		return true
-	} else if err.Error() == "operation not supported" {
+	case err.Error() == "operation not supported":
 		return true
-	} else if errors.Is(err, os.ErrInvalid) {
+	case errors.Is(err, os.ErrInvalid):
 		return true
-	} else if errors.As(err, &errno) && (errno == syscall.EINVAL) {
+	case errors.As(err, &errno) && (errno == syscall.EINVAL):
 		return true
 	}
 	// all other errors are fatal

sysfs/net_class_ecn.go

@@ -284,11 +284,12 @@ func ParseRoceRpEcnAttribute(ecnPath string, attrName string, ecn *RoceRpEcn) er
 	vp := util.NewValueParser(value)
 	switch attrName {
 	case "clamp_tgt_rate":
-		if *vp.PUInt64() == 0 {
+		switch *vp.PUInt64() {
+		case 0:
 			ecn.ClampTgtRate = false
-		} else if *vp.PUInt64() == 1 {
+		case 1:
 			ecn.ClampTgtRate = true
-		} else {
+		default:
 			return fmt.Errorf("failed to parse file %q: %w", attrPath, err)
 		}
 	case "dce_tcp_g":

sysfs/system_cpu.go

@@ -172,11 +172,12 @@ func binSearch(elem uint16, elemSlice *[]uint16) bool {
 
 	for start <= end {
 		mid = (start + end) / 2
-		if (*elemSlice)[mid] == elem {
+		switch {
+		case (*elemSlice)[mid] == elem:
 			return true
-		} else if (*elemSlice)[mid] > elem {
+		case (*elemSlice)[mid] > elem:
 			end = mid - 1
-		} else if (*elemSlice)[mid] < elem {
+		case (*elemSlice)[mid] < elem:
 			start = mid + 1
 		}
 	}
@@ -254,7 +255,8 @@ func (fs FS) SystemCpufreq() ([]SystemCPUCpufreqStats, error) {
 		})
 	}
 
-	if err = g.Wait(); err != nil {
+	err = g.Wait()
+	if err != nil {
 		return nil, err
 	}
 
@@ -364,7 +366,7 @@ func parseCpufreqCpuinfo(cpuPath string) (*SystemCPUCpufreqStats, error) {
 			fields[0] = strings.TrimSuffix(fields[0], ":")
 			cpuinfoTransitionTableRow := make([]uint64, len(fields))
 			for i := range fields {
-				if len(fields[i]) == 0 {
+				if fields[i] == "" {
 					continue
 				}
 				f, err := strconv.ParseUint(fields[i], 10, 64)

sysfs/vmstat_numa.go

@@ -30,7 +30,7 @@ import (
 
 var (
 	nodePattern      = "devices/system/node/node[0-9]*"
-	nodeNumberRegexp = regexp.MustCompile(`.*devices/system/node/node([0-9]*)`)
+	nodeNumberRegexp = regexp.MustCompile(`.*devices/system/node/node(\d*)`)
 )
 
 type VMStat struct {