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Merge pull request #16698 from rhvgoyal/drop-redundant-lock

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devmapper: Drop redundant lock and redundant function
This commit is contained in:
Alexander Morozov 2015-10-01 10:48:03 -07:00
commit 99d13e7e14
1 changed files with 30 additions and 48 deletions
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78
daemon/graphdriver/devmapper/deviceset.go
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@ -76,14 +76,13 @@ type devInfo struct {
}
type metaData struct {
Devices map[string]*devInfo `json:"Devices"`
devicesLock sync.Mutex // Protects all read/writes to Devices map
Devices map[string]*devInfo `json:"Devices"`
}
// DeviceSet holds information about list of devices
type DeviceSet struct {
metaData `json:"-"`
sync.Mutex `json:"-"` // Protects Devices map and serializes calls into libdevmapper
sync.Mutex `json:"-"` // Protects all fields of DeviceSet and serializes calls into libdevmapper
root string
devicePrefix string
TransactionID uint64 `json:"-"`
@ -355,9 +354,8 @@ func (devices *DeviceSet) isDeviceIDFree(deviceID int) bool {
return true
}
// Should be called with devices.Lock() held.
func (devices *DeviceSet) lookupDevice(hash string) (*devInfo, error) {
devices.devicesLock.Lock()
defer devices.devicesLock.Unlock()
info := devices.Devices[hash]
if info == nil {
info = devices.loadMetadata(hash)
@ -370,6 +368,13 @@ func (devices *DeviceSet) lookupDevice(hash string) (*devInfo, error) {
return info, nil
}
func (devices *DeviceSet) lookupDeviceWithLock(hash string) (*devInfo, error) {
devices.Lock()
defer devices.Unlock()
info, err := devices.lookupDevice(hash)
return info, err
}
func (devices *DeviceSet) deviceFileWalkFunction(path string, finfo os.FileInfo) error {
// Skip some of the meta files which are not device files.
@ -405,10 +410,7 @@ func (devices *DeviceSet) deviceFileWalkFunction(path string, finfo os.FileInfo)
return fmt.Errorf("Error loading device metadata file %s", hash)
}
devices.Lock()
devices.markDeviceIDUsed(dinfo.DeviceID)
devices.Unlock()
logrus.Debugf("Added deviceID=%d to DeviceIDMap", dinfo.DeviceID)
return nil
}
@ -434,6 +436,7 @@ func (devices *DeviceSet) constructDeviceIDMap() error {
return filepath.Walk(devices.metadataDir(), scan)
}
// Should be called with devices.Lock() held.
func (devices *DeviceSet) unregisterDevice(id int, hash string) error {
logrus.Debugf("unregisterDevice(%v, %v)", id, hash)
info := &devInfo{
@ -441,9 +444,7 @@ func (devices *DeviceSet) unregisterDevice(id int, hash string) error {
DeviceID: id,
}
devices.devicesLock.Lock()
delete(devices.Devices, hash)
devices.devicesLock.Unlock()
if err := devices.removeMetadata(info); err != nil {
logrus.Debugf("Error removing metadata: %s", err)
@ -453,6 +454,7 @@ func (devices *DeviceSet) unregisterDevice(id int, hash string) error {
return nil
}
// Should be called with devices.Lock() held.
func (devices *DeviceSet) registerDevice(id int, hash string, size uint64, transactionID uint64) (*devInfo, error) {
logrus.Debugf("registerDevice(%v, %v)", id, hash)
info := &devInfo{
@ -464,15 +466,11 @@ func (devices *DeviceSet) registerDevice(id int, hash string, size uint64, trans
devices: devices,
}
devices.devicesLock.Lock()
devices.Devices[hash] = info
devices.devicesLock.Unlock()
if err := devices.saveMetadata(info); err != nil {
// Try to remove unused device
devices.devicesLock.Lock()
delete(devices.Devices, hash)
devices.devicesLock.Unlock()
return nil, err
}
@ -556,6 +554,9 @@ func (devices *DeviceSet) migrateOldMetaData() error {
}
func (devices *DeviceSet) initMetaData() error {
devices.Lock()
defer devices.Unlock()
if err := devices.migrateOldMetaData(); err != nil {
return err
}
@ -596,6 +597,9 @@ func (devices *DeviceSet) getNextFreeDeviceID() (int, error) {
}
func (devices *DeviceSet) createRegisterDevice(hash string) (*devInfo, error) {
devices.Lock()
defer devices.Unlock()
deviceID, err := devices.getNextFreeDeviceID()
if err != nil {
return nil, err
@ -774,7 +778,7 @@ func (devices *DeviceSet) saveBaseDeviceUUID(baseInfo *devInfo) error {
}
func (devices *DeviceSet) setupBaseImage() error {
oldInfo, _ := devices.lookupDevice("")
oldInfo, _ := devices.lookupDeviceWithLock("")
if oldInfo != nil && oldInfo.Initialized {
// If BaseDeviceUUID is nil (upgrade case), save it and
// return success.
@ -1443,7 +1447,7 @@ func (devices *DeviceSet) AddDevice(hash, baseHash string) error {
logrus.Debugf("[deviceset] AddDevice(hash=%s basehash=%s)", hash, baseHash)
defer logrus.Debugf("[deviceset] AddDevice(hash=%s basehash=%s) END", hash, baseHash)
baseInfo, err := devices.lookupDevice(baseHash)
baseInfo, err := devices.lookupDeviceWithLock(baseHash)
if err != nil {
return err
}
@ -1465,6 +1469,7 @@ func (devices *DeviceSet) AddDevice(hash, baseHash string) error {
return nil
}
// Should be called with devices.Lock() held.
func (devices *DeviceSet) deleteDevice(info *devInfo) error {
if devices.doBlkDiscard {
// This is a workaround for the kernel not discarding block so
@ -1508,7 +1513,7 @@ func (devices *DeviceSet) deleteDevice(info *devInfo) error {
// DeleteDevice deletes a device from the hash.
func (devices *DeviceSet) DeleteDevice(hash string) error {
info, err := devices.lookupDevice(hash)
info, err := devices.lookupDeviceWithLock(hash)
if err != nil {
return err
}
@ -1651,11 +1656,11 @@ func (devices *DeviceSet) Shutdown() error {
var devs []*devInfo
devices.devicesLock.Lock()
devices.Lock()
for _, info := range devices.Devices {
devs = append(devs, info)
}
devices.devicesLock.Unlock()
devices.Unlock()
for _, info := range devs {
info.lock.Lock()
@ -1676,7 +1681,7 @@ func (devices *DeviceSet) Shutdown() error {
info.lock.Unlock()
}
info, _ := devices.lookupDevice("")
info, _ := devices.lookupDeviceWithLock("")
if info != nil {
info.lock.Lock()
devices.Lock()
@ -1702,7 +1707,7 @@ func (devices *DeviceSet) Shutdown() error {
// MountDevice mounts the device if not already mounted.
func (devices *DeviceSet) MountDevice(hash, path, mountLabel string) error {
info, err := devices.lookupDevice(hash)
info, err := devices.lookupDeviceWithLock(hash)
if err != nil {
return err
}
@ -1756,7 +1761,7 @@ func (devices *DeviceSet) UnmountDevice(hash string) error {
logrus.Debugf("[devmapper] UnmountDevice(hash=%s)", hash)
defer logrus.Debugf("[devmapper] UnmountDevice(hash=%s) END", hash)
info, err := devices.lookupDevice(hash)
info, err := devices.lookupDeviceWithLock(hash)
if err != nil {
return err
}
@ -1793,44 +1798,21 @@ func (devices *DeviceSet) UnmountDevice(hash string) error {
// HasDevice returns true if the device metadata exists.
func (devices *DeviceSet) HasDevice(hash string) bool {
devices.Lock()
defer devices.Unlock()
info, _ := devices.lookupDevice(hash)
info, _ := devices.lookupDeviceWithLock(hash)
return info != nil
}
// HasActivatedDevice return true if the device exists.
func (devices *DeviceSet) HasActivatedDevice(hash string) bool {
info, _ := devices.lookupDevice(hash)
if info == nil {
return false
}
info.lock.Lock()
defer info.lock.Unlock()
devices.Lock()
defer devices.Unlock()
devinfo, _ := devicemapper.GetInfo(info.Name())
return devinfo != nil && devinfo.Exists != 0
}
// List returns a list of device ids.
func (devices *DeviceSet) List() []string {
devices.Lock()
defer devices.Unlock()
devices.devicesLock.Lock()
ids := make([]string, len(devices.Devices))
i := 0
for k := range devices.Devices {
ids[i] = k
i++
}
devices.devicesLock.Unlock()
return ids
}
@ -1848,7 +1830,7 @@ func (devices *DeviceSet) deviceStatus(devName string) (sizeInSectors, mappedSec
// GetDeviceStatus provides size, mapped sectors
func (devices *DeviceSet) GetDeviceStatus(hash string) (*DevStatus, error) {
info, err := devices.lookupDevice(hash)
info, err := devices.lookupDeviceWithLock(hash)
if err != nil {
return nil, err
}
@ -1974,7 +1956,7 @@ func (devices *DeviceSet) Status() *Status {
// Status returns the current status of this deviceset
func (devices *DeviceSet) exportDeviceMetadata(hash string) (*deviceMetadata, error) {
info, err := devices.lookupDevice(hash)
info, err := devices.lookupDeviceWithLock(hash)
if err != nil {
return nil, err
}