diff --git a/daemon/graphdriver/devmapper/deviceset.go b/daemon/graphdriver/devmapper/deviceset.go index ffba32b916..2060be06e2 100644 --- a/daemon/graphdriver/devmapper/deviceset.go +++ b/daemon/graphdriver/devmapper/deviceset.go @@ -30,8 +30,7 @@ var ( DefaultDataLoopbackSize int64 = 100 * 1024 * 1024 * 1024 DefaultMetaDataLoopbackSize int64 = 2 * 1024 * 1024 * 1024 DefaultBaseFsSize uint64 = 10 * 1024 * 1024 * 1024 - DefaultThinpBlockSize uint32 = 128 // 64K = 128 512b sectors - DefaultUdevSyncOverride bool = false + DefaultThinpBlockSize uint32 = 128 // 64K = 128 512b sectors MaxDeviceId int = 0xffffff // 24 bit, pool limit DeviceIdMapSz int = (MaxDeviceId + 1) / 8 // We retry device removal so many a times that even error messages @@ -90,23 +89,22 @@ type DeviceSet struct { deviceIdMap []byte // Options - dataLoopbackSize int64 - metaDataLoopbackSize int64 - baseFsSize uint64 - filesystem string - mountOptions string - mkfsArgs []string - dataDevice string // block or loop dev - dataLoopFile string // loopback file, if used - metadataDevice string // block or loop dev - metadataLoopFile string // loopback file, if used - doBlkDiscard bool - thinpBlockSize uint32 - thinPoolDevice string - Transaction `json:"-"` - overrideUdevSyncCheck bool - deferredRemove bool // use deferred removal - BaseDeviceUUID string //save UUID of base device + dataLoopbackSize int64 + metaDataLoopbackSize int64 + baseFsSize uint64 + filesystem string + mountOptions string + mkfsArgs []string + dataDevice string // block or loop dev + dataLoopFile string // loopback file, if used + metadataDevice string // block or loop dev + metadataLoopFile string // loopback file, if used + doBlkDiscard bool + thinpBlockSize uint32 + thinPoolDevice string + Transaction `json:"-"` + deferredRemove bool // use deferred removal + BaseDeviceUUID string //save UUID of base device } type DiskUsage struct { @@ -1106,10 +1104,7 @@ func (devices *DeviceSet) initDevmapper(doInit bool) error { // https://github.com/docker/docker/issues/4036 if supported := devicemapper.UdevSetSyncSupport(true); !supported { - logrus.Errorf("Udev sync is not supported. This will lead to unexpected behavior, data loss and errors. For more information, see https://docs.docker.com/reference/commandline/cli/#daemon-storage-driver-option") - if !devices.overrideUdevSyncCheck { - return graphdriver.ErrNotSupported - } + logrus.Warn("Udev sync is not supported. This will lead to unexpected behavior, data loss and errors. For more information, see https://docs.docker.com/reference/commandline/cli/#daemon-storage-driver-option") } if err := os.MkdirAll(devices.metadataDir(), 0700); err != nil && !os.IsExist(err) { @@ -1791,16 +1786,15 @@ func NewDeviceSet(root string, doInit bool, options []string) (*DeviceSet, error devicemapper.SetDevDir("/dev") devices := &DeviceSet{ - root: root, - MetaData: MetaData{Devices: make(map[string]*DevInfo)}, - dataLoopbackSize: DefaultDataLoopbackSize, - metaDataLoopbackSize: DefaultMetaDataLoopbackSize, - baseFsSize: DefaultBaseFsSize, - overrideUdevSyncCheck: DefaultUdevSyncOverride, - filesystem: "ext4", - doBlkDiscard: true, - thinpBlockSize: DefaultThinpBlockSize, - deviceIdMap: make([]byte, DeviceIdMapSz), + root: root, + MetaData: MetaData{Devices: make(map[string]*DevInfo)}, + dataLoopbackSize: DefaultDataLoopbackSize, + metaDataLoopbackSize: DefaultMetaDataLoopbackSize, + baseFsSize: DefaultBaseFsSize, + filesystem: "ext4", + doBlkDiscard: true, + thinpBlockSize: DefaultThinpBlockSize, + deviceIdMap: make([]byte, DeviceIdMapSz), } foundBlkDiscard := false @@ -1857,12 +1851,6 @@ func NewDeviceSet(root string, doInit bool, options []string) (*DeviceSet, error } // convert to 512b sectors devices.thinpBlockSize = uint32(size) >> 9 - case "dm.override_udev_sync_check": - devices.overrideUdevSyncCheck, err = strconv.ParseBool(val) - if err != nil { - return nil, err - } - case "dm.use_deferred_removal": EnableDeferredRemoval, err = strconv.ParseBool(val) if err != nil { diff --git a/daemon/graphdriver/devmapper/devmapper_test.go b/daemon/graphdriver/devmapper/devmapper_test.go index 60006af5a5..6cb7572384 100644 --- a/daemon/graphdriver/devmapper/devmapper_test.go +++ b/daemon/graphdriver/devmapper/devmapper_test.go @@ -13,7 +13,6 @@ func init() { DefaultDataLoopbackSize = 300 * 1024 * 1024 DefaultMetaDataLoopbackSize = 200 * 1024 * 1024 DefaultBaseFsSize = 300 * 1024 * 1024 - DefaultUdevSyncOverride = true if err := graphtest.InitLoopbacks(); err != nil { panic(err) } diff --git a/daemon/graphdriver/driver.go b/daemon/graphdriver/driver.go index 68e1383b15..e02dafa8fb 100644 --- a/daemon/graphdriver/driver.go +++ b/daemon/graphdriver/driver.go @@ -8,6 +8,7 @@ import ( "strings" "github.com/Sirupsen/logrus" + "github.com/docker/docker/autogen/dockerversion" "github.com/docker/docker/pkg/archive" ) @@ -22,9 +23,10 @@ var ( // All registred drivers drivers map[string]InitFunc - ErrNotSupported = errors.New("driver not supported") - ErrPrerequisites = errors.New("prerequisites for driver not satisfied (wrong filesystem?)") - ErrIncompatibleFS = fmt.Errorf("backing file system is unsupported for this graph driver") + ErrNotSupported = errors.New("driver not supported") + ErrPrerequisites = errors.New("prerequisites for driver not satisfied (wrong filesystem?)") + ErrIncompatibleFS = fmt.Errorf("backing file system is unsupported for this graph driver") + ErrDeviceMapperWithStaticDocker = fmt.Errorf("devicemapper storage driver cannot reliably be used with a statically linked docker binary: please either pick a different storage driver, install a dynamically linked docker binary, or force this unreliable setup anyway by specifying --storage-driver=devicemapper") ) type InitFunc func(root string, options []string) (Driver, error) @@ -113,36 +115,35 @@ func New(root string, options []string) (driver Driver, err error) { } // Guess for prior driver - priorDrivers := scanPriorDrivers(root) - for _, name := range priority { - if name == "vfs" { - // don't use vfs even if there is state present. - continue + priorDriver, err := scanPriorDrivers(root) + if err != nil { + return nil, err + } + + if len(priorDriver) != 0 { + // Do not allow devicemapper when it's not explicit and the Docker binary was built statically. + if staticWithDeviceMapper(priorDriver) { + return nil, ErrDeviceMapperWithStaticDocker } - for _, prior := range priorDrivers { - // of the state found from prior drivers, check in order of our priority - // which we would prefer - if prior == name { - driver, err = GetDriver(name, root, options) - if err != nil { - // unlike below, we will return error here, because there is prior - // state, and now it is no longer supported/prereq/compatible, so - // something changed and needs attention. Otherwise the daemon's - // images would just "disappear". - logrus.Errorf("[graphdriver] prior storage driver %q failed: %s", name, err) - return nil, err - } - if err := checkPriorDriver(name, root); err != nil { - return nil, err - } - logrus.Infof("[graphdriver] using prior storage driver %q", name) - return driver, nil - } + + driver, err = GetDriver(priorDriver, root, options) + if err != nil { + // unlike below, we will return error here, because there is prior + // state, and now it is no longer supported/prereq/compatible, so + // something changed and needs attention. Otherwise the daemon's + // images would just "disappear". + logrus.Errorf("[graphdriver] prior storage driver %q failed: %s", priorDriver, err) + return nil, err } + logrus.Infof("[graphdriver] using prior storage driver %q", priorDriver) + return driver, nil } // Check for priority drivers first for _, name := range priority { + if staticWithDeviceMapper(name) { + continue + } driver, err = GetDriver(name, root, options) if err != nil { if err == ErrNotSupported || err == ErrPrerequisites || err == ErrIncompatibleFS { @@ -154,7 +155,10 @@ func New(root string, options []string) (driver Driver, err error) { } // Check all registered drivers if no priority driver is found - for _, initFunc := range drivers { + for name, initFunc := range drivers { + if staticWithDeviceMapper(name) { + continue + } if driver, err = initFunc(root, options); err != nil { if err == ErrNotSupported || err == ErrPrerequisites || err == ErrIncompatibleFS { continue @@ -166,31 +170,31 @@ func New(root string, options []string) (driver Driver, err error) { return nil, fmt.Errorf("No supported storage backend found") } -// scanPriorDrivers returns an un-ordered scan of directories of prior storage drivers -func scanPriorDrivers(root string) []string { - priorDrivers := []string{} +// scanPriorDrivers returns a previosly used driver. +// it returns an error when there are several drivers scanned. +func scanPriorDrivers(root string) (string, error) { + var priorDrivers []string for driver := range drivers { p := filepath.Join(root, driver) - if _, err := os.Stat(p); err == nil { + if _, err := os.Stat(p); err == nil && driver != "vfs" { priorDrivers = append(priorDrivers, driver) } } - return priorDrivers -} -func checkPriorDriver(name, root string) error { - priorDrivers := []string{} - for _, prior := range scanPriorDrivers(root) { - if prior != name && prior != "vfs" { - if _, err := os.Stat(filepath.Join(root, prior)); err == nil { - priorDrivers = append(priorDrivers, prior) - } - } + if len(priorDrivers) > 1 { + return "", multipleDriversError(root, priorDrivers) } - if len(priorDrivers) > 0 { - - return errors.New(fmt.Sprintf("%q contains other graphdrivers: %s; Please cleanup or explicitly choose storage driver (-s )", root, strings.Join(priorDrivers, ","))) + if len(priorDrivers) == 0 { + return "", nil } - return nil + return priorDrivers[0], nil +} + +func multipleDriversError(root string, drivers []string) error { + return fmt.Errorf("%q contains several graphdrivers: %s; Please cleanup or explicitly choose storage driver (--storage-driver )", root, strings.Join(drivers, ", ")) +} + +func staticWithDeviceMapper(name string) bool { + return name == "devicemapper" && dockerversion.IAMSTATIC == "true" } diff --git a/docs/reference/commandline/daemon.md b/docs/reference/commandline/daemon.md index 0cd9f734e0..cb56ab5454 100644 --- a/docs/reference/commandline/daemon.md +++ b/docs/reference/commandline/daemon.md @@ -323,42 +323,6 @@ options for `zfs` start with `zfs`. $ docker -d --storage-opt dm.blkdiscard=false - * `dm.override_udev_sync_check` - - Overrides the `udev` synchronization checks between `devicemapper` and `udev`. - `udev` is the device manager for the Linux kernel. - - To view the `udev` sync support of a Docker daemon that is using the - `devicemapper` driver, run: - - $ docker info - [...] - Udev Sync Supported: true - [...] - - When `udev` sync support is `true`, then `devicemapper` and udev can - coordinate the activation and deactivation of devices for containers. - - When `udev` sync support is `false`, a race condition occurs between - the`devicemapper` and `udev` during create and cleanup. The race condition - results in errors and failures. (For information on these failures, see - [docker#4036](https://github.com/docker/docker/issues/4036)) - - To allow the `docker` daemon to start, regardless of `udev` sync not being - supported, set `dm.override_udev_sync_check` to true: - - $ docker -d --storage-opt dm.override_udev_sync_check=true - - When this value is `true`, the `devicemapper` continues and simply warns - you the errors are happening. - - > **Note:** - > The ideal is to pursue a `docker` daemon and environment that does - > support synchronizing with `udev`. For further discussion on this - > topic, see [docker#4036](https://github.com/docker/docker/issues/4036). - > Otherwise, set this flag for migrating existing Docker daemons to - > a daemon with a supported environment. - ## Docker execdriver option diff --git a/man/docker.1.md b/man/docker.1.md index 98135e50ff..ee0344a14f 100644 --- a/man/docker.1.md +++ b/man/docker.1.md @@ -451,45 +451,6 @@ removed. Example use: `docker -d --storage-opt dm.blkdiscard=false` -#### dm.override_udev_sync_check - -By default, the devicemapper backend attempts to synchronize with the -`udev` device manager for the Linux kernel. This option allows -disabling that synchronization, to continue even though the -configuration may be buggy. - -To view the `udev` sync support of a Docker daemon that is using the -`devicemapper` driver, run: - - $ docker info - [...] - Udev Sync Supported: true - [...] - -When `udev` sync support is `true`, then `devicemapper` and `udev` can -coordinate the activation and deactivation of devices for containers. - -When `udev` sync support is `false`, a race condition occurs between -the`devicemapper` and `udev` during create and cleanup. The race -condition results in errors and failures. (For information on these -failures, see -[docker#4036](https://github.com/docker/docker/issues/4036)) - -To allow the `docker` daemon to start, regardless of whether `udev` sync is -`false`, set `dm.override_udev_sync_check` to true: - - $ docker -d --storage-opt dm.override_udev_sync_check=true - -When this value is `true`, the driver continues and simply warns you -the errors are happening. - -**Note**: The ideal is to pursue a `docker` daemon and environment -that does support synchronizing with `udev`. For further discussion on -this topic, see -[docker#4036](https://github.com/docker/docker/issues/4036). -Otherwise, set this flag for migrating existing Docker daemons to a -daemon with a supported environment. - # EXEC DRIVER OPTIONS Use the **--exec-opt** flags to specify options to the exec-driver. The only