rclone/fs/accounting/stats.go
Nick Craig-Wood f5439ddc54 accounting: fix deadlock in stats printing
The deadlock was caused in transfermap.go by calling mu.RLock() in one
function then calling it again in a sub function. Normally this is
fine, however this leaves a window where mu.Lock() can be called. When
mu.Lock() is called it doesn't allow the second mu.RLock() and
deadlocks.

    Thead 1                    Thread 2
    String():mu.RLock()
                               del():mu.Lock()
    sortedSlice():mu.RLock()                     - DEADLOCK

Lesson learnt: don't try using locks recursively ever!

This patch fixes the problem by removing the second mu.RLock(). This
was done by factoring the code that was calling it into the
transfermap.go file so all the locking can be seen at once which was
ultimately the cause of the problem - the code which used the locks
was too far away from the rest of the code using the lock.

This problem was introduced in:

bfa5715017 fs/accounting: sort transfers by start time

Which hasn't been released in a stable version yet
2020-08-05 17:13:00 +01:00

671 lines
17 KiB
Go

package accounting
import (
"bytes"
"fmt"
"sort"
"strings"
"sync"
"time"
"github.com/rclone/rclone/fs"
"github.com/rclone/rclone/fs/fserrors"
"github.com/rclone/rclone/fs/rc"
)
// MaxCompletedTransfers specifies maximum number of completed transfers in startedTransfers list
var MaxCompletedTransfers = 100
var startTime = time.Now()
// StatsInfo accounts all transfers
type StatsInfo struct {
mu sync.RWMutex
bytes int64
errors int64
lastError error
fatalError bool
retryError bool
retryAfter time.Time
checks int64
checking *transferMap
checkQueue int
checkQueueSize int64
transfers int64
transferring *transferMap
transferQueue int
transferQueueSize int64
renames int64
renameQueue int
renameQueueSize int64
deletes int64
inProgress *inProgress
startedTransfers []*Transfer // currently active transfers
oldTimeRanges timeRanges // a merged list of time ranges for the transfers
oldDuration time.Duration // duration of transfers we have culled
group string
}
// NewStats creates an initialised StatsInfo
func NewStats() *StatsInfo {
return &StatsInfo{
checking: newTransferMap(fs.Config.Checkers, "checking"),
transferring: newTransferMap(fs.Config.Transfers, "transferring"),
inProgress: newInProgress(),
}
}
// RemoteStats returns stats for rc
func (s *StatsInfo) RemoteStats() (out rc.Params, err error) {
out = make(rc.Params)
s.mu.RLock()
out["speed"] = s.Speed()
out["bytes"] = s.bytes
out["errors"] = s.errors
out["fatalError"] = s.fatalError
out["retryError"] = s.retryError
out["checks"] = s.checks
out["transfers"] = s.transfers
out["deletes"] = s.deletes
out["renames"] = s.renames
out["transferTime"] = s.totalDuration().Seconds()
out["elapsedTime"] = time.Since(startTime).Seconds()
s.mu.RUnlock()
if !s.checking.empty() {
out["checking"] = s.checking.remotes()
}
if !s.transferring.empty() {
out["transferring"] = s.transferring.rcStats(s.inProgress)
}
if s.errors > 0 {
out["lastError"] = s.lastError.Error()
}
return out, nil
}
// Speed returns the average speed of the transfer in bytes/second
func (s *StatsInfo) Speed() float64 {
dt := s.totalDuration()
dtSeconds := dt.Seconds()
speed := 0.0
if dt > 0 {
speed = float64(s.bytes) / dtSeconds
}
return speed
}
// timeRange is a start and end time of a transfer
type timeRange struct {
start time.Time
end time.Time
}
// timeRanges is a list of non-overlapping start and end times for
// transfers
type timeRanges []timeRange
// merge all the overlapping time ranges
func (trs *timeRanges) merge() {
Trs := *trs
// Sort by the starting time.
sort.Slice(Trs, func(i, j int) bool {
return Trs[i].start.Before(Trs[j].start)
})
// Merge overlaps and add distinctive ranges together
var (
newTrs = Trs[:0]
i, j = 0, 1
)
for i < len(Trs) {
if j < len(Trs) {
if !Trs[i].end.Before(Trs[j].start) {
if Trs[i].end.Before(Trs[j].end) {
Trs[i].end = Trs[j].end
}
j++
continue
}
}
newTrs = append(newTrs, Trs[i])
i = j
j++
}
*trs = newTrs
}
// cull remove any ranges whose start and end are before cutoff
// returning their duration sum
func (trs *timeRanges) cull(cutoff time.Time) (d time.Duration) {
var newTrs = (*trs)[:0]
for _, tr := range *trs {
if cutoff.Before(tr.start) || cutoff.Before(tr.end) {
newTrs = append(newTrs, tr)
} else {
d += tr.end.Sub(tr.start)
}
}
*trs = newTrs
return d
}
// total the time out of the time ranges
func (trs timeRanges) total() (total time.Duration) {
for _, tr := range trs {
total += tr.end.Sub(tr.start)
}
return total
}
// Total duration is union of durations of all transfers belonging to this
// object.
// Needs to be protected by mutex.
func (s *StatsInfo) totalDuration() time.Duration {
// copy of s.oldTimeRanges with extra room for the current transfers
timeRanges := make(timeRanges, len(s.oldTimeRanges), len(s.oldTimeRanges)+len(s.startedTransfers))
copy(timeRanges, s.oldTimeRanges)
// Extract time ranges of all transfers.
now := time.Now()
for i := range s.startedTransfers {
start, end := s.startedTransfers[i].TimeRange()
if end.IsZero() {
end = now
}
timeRanges = append(timeRanges, timeRange{start, end})
}
timeRanges.merge()
return s.oldDuration + timeRanges.total()
}
// eta returns the ETA of the current operation,
// rounded to full seconds.
// If the ETA cannot be determined 'ok' returns false.
func eta(size, total int64, rate float64) (eta time.Duration, ok bool) {
if total <= 0 || size < 0 || rate <= 0 {
return 0, false
}
remaining := total - size
if remaining < 0 {
return 0, false
}
seconds := float64(remaining) / rate
return time.Second * time.Duration(seconds), true
}
// etaString returns the ETA of the current operation,
// rounded to full seconds.
// If the ETA cannot be determined it returns "-"
func etaString(done, total int64, rate float64) string {
d, ok := eta(done, total, rate)
if !ok {
return "-"
}
return fs.Duration(d).ReadableString()
}
// percent returns a/b as a percentage rounded to the nearest integer
// as a string
//
// if the percentage is invalid it returns "-"
func percent(a int64, b int64) string {
if a < 0 || b <= 0 {
return "-"
}
return fmt.Sprintf("%d%%", int(float64(a)*100/float64(b)+0.5))
}
// String convert the StatsInfo to a string for printing
func (s *StatsInfo) String() string {
// checking and transferring have their own locking so read
// here before lock to prevent deadlock on GetBytes
transferring, checking := s.transferring.count(), s.checking.count()
transferringBytesDone, transferringBytesTotal := s.transferring.progress(s)
s.mu.RLock()
elapsedTime := time.Since(startTime)
elapsedTimeSecondsOnly := elapsedTime.Truncate(time.Second/10) % time.Minute
dt := s.totalDuration()
dtSeconds := dt.Seconds()
speed := 0.0
if dt > 0 {
speed = float64(s.bytes) / dtSeconds
}
displaySpeed := speed
if fs.Config.DataRateUnit == "bits" {
displaySpeed *= 8
}
var (
totalChecks = int64(s.checkQueue) + s.checks + int64(checking)
totalTransfer = int64(s.transferQueue) + s.transfers + int64(transferring)
// note that s.bytes already includes transferringBytesDone so
// we take it off here to avoid double counting
totalSize = s.transferQueueSize + s.bytes + transferringBytesTotal - transferringBytesDone
currentSize = s.bytes
buf = &bytes.Buffer{}
xfrchkString = ""
dateString = ""
)
if !fs.Config.StatsOneLine {
_, _ = fmt.Fprintf(buf, "\nTransferred: ")
} else {
xfrchk := []string{}
if totalTransfer > 0 && s.transferQueue > 0 {
xfrchk = append(xfrchk, fmt.Sprintf("xfr#%d/%d", s.transfers, totalTransfer))
}
if totalChecks > 0 && s.checkQueue > 0 {
xfrchk = append(xfrchk, fmt.Sprintf("chk#%d/%d", s.checks, totalChecks))
}
if len(xfrchk) > 0 {
xfrchkString = fmt.Sprintf(" (%s)", strings.Join(xfrchk, ", "))
}
if fs.Config.StatsOneLineDate {
t := time.Now()
dateString = t.Format(fs.Config.StatsOneLineDateFormat) // Including the separator so people can customize it
}
}
_, _ = fmt.Fprintf(buf, "%s%10s / %s, %s, %s, ETA %s%s\n",
dateString,
fs.SizeSuffix(s.bytes),
fs.SizeSuffix(totalSize).Unit("Bytes"),
percent(s.bytes, totalSize),
fs.SizeSuffix(displaySpeed).Unit(strings.Title(fs.Config.DataRateUnit)+"/s"),
etaString(currentSize, totalSize, speed),
xfrchkString,
)
if !fs.Config.StatsOneLine {
errorDetails := ""
switch {
case s.fatalError:
errorDetails = " (fatal error encountered)"
case s.retryError:
errorDetails = " (retrying may help)"
case s.errors != 0:
errorDetails = " (no need to retry)"
}
// Add only non zero stats
if s.errors != 0 {
_, _ = fmt.Fprintf(buf, "Errors: %10d%s\n",
s.errors, errorDetails)
}
if s.checks != 0 || totalChecks != 0 {
_, _ = fmt.Fprintf(buf, "Checks: %10d / %d, %s\n",
s.checks, totalChecks, percent(s.checks, totalChecks))
}
if s.deletes != 0 {
_, _ = fmt.Fprintf(buf, "Deleted: %10d\n", s.deletes)
}
if s.renames != 0 {
_, _ = fmt.Fprintf(buf, "Renamed: %10d\n", s.renames)
}
if s.transfers != 0 || totalTransfer != 0 {
_, _ = fmt.Fprintf(buf, "Transferred: %10d / %d, %s\n",
s.transfers, totalTransfer, percent(s.transfers, totalTransfer))
}
_, _ = fmt.Fprintf(buf, "Elapsed time: %10ss\n", strings.TrimRight(elapsedTime.Truncate(time.Minute).String(), "0s")+fmt.Sprintf("%.1f", elapsedTimeSecondsOnly.Seconds()))
}
// checking and transferring have their own locking so unlock
// here to prevent deadlock on GetBytes
s.mu.RUnlock()
// Add per transfer stats if required
if !fs.Config.StatsOneLine {
if !s.checking.empty() {
_, _ = fmt.Fprintf(buf, "Checking:\n%s\n", s.checking.String(s.inProgress, s.transferring))
}
if !s.transferring.empty() {
_, _ = fmt.Fprintf(buf, "Transferring:\n%s\n", s.transferring.String(s.inProgress, nil))
}
}
return buf.String()
}
// Transferred returns list of all completed transfers including checked and
// failed ones.
func (s *StatsInfo) Transferred() []TransferSnapshot {
ts := make([]TransferSnapshot, 0, len(s.startedTransfers))
for _, tr := range s.startedTransfers {
if tr.IsDone() {
ts = append(ts, tr.Snapshot())
}
}
return ts
}
// Log outputs the StatsInfo to the log
func (s *StatsInfo) Log() {
if fs.Config.UseJSONLog {
out, _ := s.RemoteStats()
fs.LogLevelPrintf(fs.Config.StatsLogLevel, nil, "%v%v\n", s, fs.LogValue("stats", out))
} else {
fs.LogLevelPrintf(fs.Config.StatsLogLevel, nil, "%v\n", s)
}
}
// Bytes updates the stats for bytes bytes
func (s *StatsInfo) Bytes(bytes int64) {
s.mu.Lock()
defer s.mu.Unlock()
s.bytes += bytes
}
// GetBytes returns the number of bytes transferred so far
func (s *StatsInfo) GetBytes() int64 {
s.mu.RLock()
defer s.mu.RUnlock()
return s.bytes
}
// GetBytesWithPending returns the number of bytes transferred and remaining transfers
func (s *StatsInfo) GetBytesWithPending() int64 {
s.mu.RLock()
defer s.mu.RUnlock()
pending := int64(0)
for _, tr := range s.startedTransfers {
if tr.acc != nil {
bytes, size := tr.acc.progress()
if bytes < size {
pending += size - bytes
}
}
}
return s.bytes + pending
}
// Errors updates the stats for errors
func (s *StatsInfo) Errors(errors int64) {
s.mu.Lock()
defer s.mu.Unlock()
s.errors += errors
}
// GetErrors reads the number of errors
func (s *StatsInfo) GetErrors() int64 {
s.mu.RLock()
defer s.mu.RUnlock()
return s.errors
}
// GetLastError returns the lastError
func (s *StatsInfo) GetLastError() error {
s.mu.RLock()
defer s.mu.RUnlock()
return s.lastError
}
// GetChecks returns the number of checks
func (s *StatsInfo) GetChecks() int64 {
s.mu.RLock()
defer s.mu.RUnlock()
return s.checks
}
// FatalError sets the fatalError flag
func (s *StatsInfo) FatalError() {
s.mu.Lock()
defer s.mu.Unlock()
s.fatalError = true
}
// HadFatalError returns whether there has been at least one FatalError
func (s *StatsInfo) HadFatalError() bool {
s.mu.RLock()
defer s.mu.RUnlock()
return s.fatalError
}
// RetryError sets the retryError flag
func (s *StatsInfo) RetryError() {
s.mu.Lock()
defer s.mu.Unlock()
s.retryError = true
}
// HadRetryError returns whether there has been at least one non-NoRetryError
func (s *StatsInfo) HadRetryError() bool {
s.mu.RLock()
defer s.mu.RUnlock()
return s.retryError
}
// Deletes updates the stats for deletes
func (s *StatsInfo) Deletes(deletes int64) int64 {
s.mu.Lock()
defer s.mu.Unlock()
s.deletes += deletes
return s.deletes
}
// Renames updates the stats for renames
func (s *StatsInfo) Renames(renames int64) int64 {
s.mu.Lock()
defer s.mu.Unlock()
s.renames += renames
return s.renames
}
// ResetCounters sets the counters (bytes, checks, errors, transfers, deletes, renames) to 0 and resets lastError, fatalError and retryError
func (s *StatsInfo) ResetCounters() {
s.mu.Lock()
defer s.mu.Unlock()
s.bytes = 0
s.errors = 0
s.lastError = nil
s.fatalError = false
s.retryError = false
s.retryAfter = time.Time{}
s.checks = 0
s.transfers = 0
s.deletes = 0
s.renames = 0
s.startedTransfers = nil
s.oldDuration = 0
}
// ResetErrors sets the errors count to 0 and resets lastError, fatalError and retryError
func (s *StatsInfo) ResetErrors() {
s.mu.Lock()
defer s.mu.Unlock()
s.errors = 0
s.lastError = nil
s.fatalError = false
s.retryError = false
s.retryAfter = time.Time{}
}
// Errored returns whether there have been any errors
func (s *StatsInfo) Errored() bool {
s.mu.RLock()
defer s.mu.RUnlock()
return s.errors != 0
}
// Error adds a single error into the stats, assigns lastError and eventually sets fatalError or retryError
func (s *StatsInfo) Error(err error) error {
if err == nil || fserrors.IsCounted(err) {
return err
}
s.mu.Lock()
defer s.mu.Unlock()
s.errors++
s.lastError = err
err = fserrors.FsError(err)
fserrors.Count(err)
switch {
case fserrors.IsFatalError(err):
s.fatalError = true
case fserrors.IsRetryAfterError(err):
retryAfter := fserrors.RetryAfterErrorTime(err)
if s.retryAfter.IsZero() || retryAfter.Sub(s.retryAfter) > 0 {
s.retryAfter = retryAfter
}
s.retryError = true
case !fserrors.IsNoRetryError(err):
s.retryError = true
}
return err
}
// RetryAfter returns the time to retry after if it is set. It will
// be Zero if it isn't set.
func (s *StatsInfo) RetryAfter() time.Time {
s.mu.Lock()
defer s.mu.Unlock()
return s.retryAfter
}
// NewCheckingTransfer adds a checking transfer to the stats, from the object.
func (s *StatsInfo) NewCheckingTransfer(obj fs.Object) *Transfer {
tr := newCheckingTransfer(s, obj)
s.checking.add(tr)
return tr
}
// DoneChecking removes a check from the stats
func (s *StatsInfo) DoneChecking(remote string) {
s.checking.del(remote)
s.mu.Lock()
s.checks++
s.mu.Unlock()
}
// GetTransfers reads the number of transfers
func (s *StatsInfo) GetTransfers() int64 {
s.mu.RLock()
defer s.mu.RUnlock()
return s.transfers
}
// NewTransfer adds a transfer to the stats from the object.
func (s *StatsInfo) NewTransfer(obj fs.Object) *Transfer {
tr := newTransfer(s, obj)
s.transferring.add(tr)
return tr
}
// NewTransferRemoteSize adds a transfer to the stats based on remote and size.
func (s *StatsInfo) NewTransferRemoteSize(remote string, size int64) *Transfer {
tr := newTransferRemoteSize(s, remote, size, false)
s.transferring.add(tr)
return tr
}
// DoneTransferring removes a transfer from the stats
//
// if ok is true then it increments the transfers count
func (s *StatsInfo) DoneTransferring(remote string, ok bool) {
s.transferring.del(remote)
if ok {
s.mu.Lock()
s.transfers++
s.mu.Unlock()
}
}
// SetCheckQueue sets the number of queued checks
func (s *StatsInfo) SetCheckQueue(n int, size int64) {
s.mu.Lock()
s.checkQueue = n
s.checkQueueSize = size
s.mu.Unlock()
}
// SetTransferQueue sets the number of queued transfers
func (s *StatsInfo) SetTransferQueue(n int, size int64) {
s.mu.Lock()
s.transferQueue = n
s.transferQueueSize = size
s.mu.Unlock()
}
// SetRenameQueue sets the number of queued transfers
func (s *StatsInfo) SetRenameQueue(n int, size int64) {
s.mu.Lock()
s.renameQueue = n
s.renameQueueSize = size
s.mu.Unlock()
}
// AddTransfer adds reference to the started transfer.
func (s *StatsInfo) AddTransfer(transfer *Transfer) {
s.mu.Lock()
s.startedTransfers = append(s.startedTransfers, transfer)
s.mu.Unlock()
}
// removeTransfer removes a reference to the started transfer in
// position i.
//
// Must be called with the lock held
func (s *StatsInfo) removeTransfer(transfer *Transfer, i int) {
now := time.Now()
// add finished transfer onto old time ranges
start, end := transfer.TimeRange()
if end.IsZero() {
end = now
}
s.oldTimeRanges = append(s.oldTimeRanges, timeRange{start, end})
s.oldTimeRanges.merge()
// remove the found entry
s.startedTransfers = append(s.startedTransfers[:i], s.startedTransfers[i+1:]...)
// Find youngest active transfer
oldestStart := now
for i := range s.startedTransfers {
start, _ := s.startedTransfers[i].TimeRange()
if start.Before(oldestStart) {
oldestStart = start
}
}
// remove old entries older than that
s.oldDuration += s.oldTimeRanges.cull(oldestStart)
}
// RemoveTransfer removes a reference to the started transfer.
func (s *StatsInfo) RemoveTransfer(transfer *Transfer) {
s.mu.Lock()
for i, tr := range s.startedTransfers {
if tr == transfer {
s.removeTransfer(tr, i)
break
}
}
s.mu.Unlock()
}
// PruneTransfers makes sure there aren't too many old transfers by removing
// single finished transfer.
func (s *StatsInfo) PruneTransfers() {
if MaxCompletedTransfers < 0 {
return
}
s.mu.Lock()
// remove a transfer from the start if we are over quota
if len(s.startedTransfers) > MaxCompletedTransfers+fs.Config.Transfers {
for i, tr := range s.startedTransfers {
if tr.IsDone() {
s.removeTransfer(tr, i)
break
}
}
}
s.mu.Unlock()
}