55 lines
1.5 KiB
Go
55 lines
1.5 KiB
Go
package hcsshim
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import (
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"syscall"
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"github.com/Sirupsen/logrus"
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)
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// GetLayerMountPath will look for a mounted layer with the given id and return
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// the path at which that layer can be accessed. This path may be a volume path
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// if the layer is a mounted read-write layer, otherwise it is expected to be the
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// folder path at which the layer is stored.
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func GetLayerMountPath(info DriverInfo, id string) (string, error) {
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title := "hcsshim::GetLayerMountPath "
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logrus.Debugf(title+"Flavour %d ID %s", info.Flavour, id)
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// Convert info to API calling convention
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infop, err := convertDriverInfo(info)
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if err != nil {
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logrus.Error(err)
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return "", err
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}
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var mountPathLength uintptr
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mountPathLength = 0
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// Call the procedure itself.
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logrus.Debugf("Calling proc (1)")
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err = getLayerMountPath(&infop, id, &mountPathLength, nil)
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if err != nil {
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err = makeErrorf(err, title, "(first call) id=%s flavour=%d", id, info.Flavour)
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logrus.Error(err)
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return "", err
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}
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// Allocate a mount path of the returned length.
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if mountPathLength == 0 {
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return "", nil
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}
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mountPathp := make([]uint16, mountPathLength)
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mountPathp[0] = 0
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// Call the procedure again
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logrus.Debugf("Calling proc (2)")
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err = getLayerMountPath(&infop, id, &mountPathLength, &mountPathp[0])
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if err != nil {
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err = makeErrorf(err, title, "(second call) id=%s flavour=%d", id, info.Flavour)
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logrus.Error(err)
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return "", err
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}
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path := syscall.UTF16ToString(mountPathp[0:])
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logrus.Debugf(title+"succeeded flavour=%d id=%s path=%s", info.Flavour, id, path)
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return path, nil
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}
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