Browse code
overlay: move supportsMultipleLowerDir to utils
This moves supportsMultipleLowerDir() to overlayutils
so it can be used from both overlay and overlay2.
The only changes made were:
* replace logger with logrus
* don't use workDirName mergedDirName constants
* add mnt var to improve readability a bit
This is a preparation for the next commit.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Kir Kolyshkin authored on 2019/11/08 07:20:40Showing 3 changed files
- daemon/graphdriver/overlay2/check.go
- daemon/graphdriver/overlay2/overlay.go
- daemon/graphdriver/overlayutils/overlayutils.go
| ... | ... |
@@ -99,35 +99,3 @@ func doesSupportNativeDiff(d string) error {
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| 99 | 99 |
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| 100 | 100 |
return nil |
| 101 | 101 |
} |
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- |
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-// supportsMultipleLowerDir checks if the system supports multiple lowerdirs, |
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-// which is required for the overlay2 driver. On 4.x kernels, multiple lowerdirs |
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-// are always available (so this check isn't needed), and backported to RHEL and |
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-// CentOS 3.x kernels (3.10.0-693.el7.x86_64 and up). This function is to detect |
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-// support on those kernels, without doing a kernel version compare. |
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-func supportsMultipleLowerDir(d string) error {
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- td, err := ioutil.TempDir(d, "multiple-lowerdir-check") |
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- if err != nil {
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- return err |
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- } |
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- defer func() {
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- if err := os.RemoveAll(td); err != nil {
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- logger.Warnf("Failed to remove check directory %v: %v", td, err)
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- } |
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- }() |
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- |
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- for _, dir := range []string{"lower1", "lower2", "upper", workDirName, mergedDirName} {
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- if err := os.Mkdir(filepath.Join(td, dir), 0755); err != nil {
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- return err |
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- } |
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- } |
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- |
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- opts := fmt.Sprintf("lowerdir=%s:%s,upperdir=%s,workdir=%s", path.Join(td, "lower2"), path.Join(td, "lower1"), path.Join(td, "upper"), path.Join(td, workDirName))
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| 126 |
- if err := unix.Mount("overlay", filepath.Join(td, mergedDirName), "overlay", 0, opts); err != nil {
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- return errors.Wrap(err, "failed to mount overlay") |
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- } |
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- if err := unix.Unmount(filepath.Join(td, mergedDirName), 0); err != nil {
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- logger.Warnf("Failed to unmount check directory %v: %v", filepath.Join(td, mergedDirName), err)
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- } |
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- return nil |
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-} |
| ... | ... |
@@ -180,7 +180,7 @@ func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (grap |
| 180 | 180 |
if opts.overrideKernelCheck {
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| 181 | 181 |
logger.Warn("Using pre-4.0.0 kernel for overlay2, mount failures may require kernel update")
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| 182 | 182 |
} else {
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| 183 |
- if err := supportsMultipleLowerDir(testdir); err != nil {
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| 183 |
+ if err := overlayutils.SupportsMultipleLowerDir(testdir); err != nil {
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| 184 | 184 |
logger.Debugf("Multiple lower dirs not supported: %v", err)
|
| 185 | 185 |
return nil, graphdriver.ErrNotSupported |
| 186 | 186 |
} |
| ... | ... |
@@ -4,8 +4,15 @@ package overlayutils // import "github.com/docker/docker/daemon/graphdriver/over |
| 4 | 4 |
|
| 5 | 5 |
import ( |
| 6 | 6 |
"fmt" |
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+ "io/ioutil" |
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+ "os" |
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+ "path" |
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+ "path/filepath" |
|
| 7 | 11 |
|
| 8 | 12 |
"github.com/docker/docker/daemon/graphdriver" |
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+ "github.com/pkg/errors" |
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+ "github.com/sirupsen/logrus" |
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+ "golang.org/x/sys/unix" |
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) |
| 10 | 17 |
|
| 11 | 18 |
// ErrDTypeNotSupported denotes that the backing filesystem doesn't support d_type. |
| ... | ... |
@@ -23,3 +30,36 @@ func ErrDTypeNotSupported(driver, backingFs string) error {
|
| 23 | 23 |
|
| 24 | 24 |
return graphdriver.NotSupportedError(msg) |
| 25 | 25 |
} |
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+ |
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+// SupportsMultipleLowerDir checks if the system supports multiple lowerdirs, |
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+// which is required for the overlay2 driver. On 4.x kernels, multiple lowerdirs |
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+// are always available (so this check isn't needed), and backported to RHEL and |
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+// CentOS 3.x kernels (3.10.0-693.el7.x86_64 and up). This function is to detect |
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+// support on those kernels, without doing a kernel version compare. |
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+func SupportsMultipleLowerDir(d string) error {
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+ td, err := ioutil.TempDir(d, "multiple-lowerdir-check") |
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+ if err != nil {
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+ return err |
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+ } |
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+ defer func() {
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+ if err := os.RemoveAll(td); err != nil {
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+ logrus.Warnf("Failed to remove check directory %v: %v", td, err)
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+ } |
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+ }() |
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+ |
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+ for _, dir := range []string{"lower1", "lower2", "upper", "work", "merged"} {
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+ if err := os.Mkdir(filepath.Join(td, dir), 0755); err != nil {
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+ return err |
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+ } |
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+ } |
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+ |
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+ mnt := filepath.Join(td, "merged") |
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+ opts := fmt.Sprintf("lowerdir=%s:%s,upperdir=%s,workdir=%s", path.Join(td, "lower2"), path.Join(td, "lower1"), path.Join(td, "upper"), path.Join(td, "work"))
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+ if err := unix.Mount("overlay", mnt, "overlay", 0, opts); err != nil {
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+ return errors.Wrap(err, "failed to mount overlay") |
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+ } |
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+ if err := unix.Unmount(mnt, 0); err != nil {
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+ logrus.Warnf("Failed to unmount check directory %v: %v", mnt, err)
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+ } |
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+ return nil |
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+} |