kubernetes/vendor/github.com/Microsoft/hcsshim/internal/wclayer/getlayermountpath.go
Daniel Canter 3eef755b3b vendor: bump hcsshim to v0.8.22
This tag of hcsshim brings in a couple welcome features/improvements. One being
exposing a way to query for hns endpoint statistics (Packets received/sent etc.).
This tag also contains some optimizations for querying whether a certain HCN feature
is supported, which is a common workflow in kube-proxy on Windows. The first result
from querying HCN is now cached so further calls can skip the hcn query as well as the
version range parsing that was performed. This also gets rid of some redundant logs
that used to hit everytime the version range parsing occurred.

The Go-winio dep bump, and all of the ctrd deps are transitive only. Nothing new is needed/intended
to be used.

Signed-off-by: Daniel Canter <dcanter@microsoft.com>
2021-09-10 00:54:24 -07:00

51 lines
1.6 KiB
Go

package wclayer
import (
"context"
"syscall"
"github.com/Microsoft/hcsshim/internal/hcserror"
"github.com/Microsoft/hcsshim/internal/log"
"github.com/Microsoft/hcsshim/internal/oc"
"go.opencensus.io/trace"
)
// GetLayerMountPath will look for a mounted layer with the given path and return
// the path at which that layer can be accessed. This path may be a volume path
// if the layer is a mounted read-write layer, otherwise it is expected to be the
// folder path at which the layer is stored.
func GetLayerMountPath(ctx context.Context, path string) (_ string, err error) {
title := "hcsshim::GetLayerMountPath"
ctx, span := trace.StartSpan(ctx, title)
defer span.End()
defer func() { oc.SetSpanStatus(span, err) }()
span.AddAttributes(trace.StringAttribute("path", path))
var mountPathLength uintptr = 0
// Call the procedure itself.
log.G(ctx).Debug("Calling proc (1)")
err = getLayerMountPath(&stdDriverInfo, path, &mountPathLength, nil)
if err != nil {
return "", hcserror.New(err, title+" - failed", "(first call)")
}
// Allocate a mount path of the returned length.
if mountPathLength == 0 {
return "", nil
}
mountPathp := make([]uint16, mountPathLength)
mountPathp[0] = 0
// Call the procedure again
log.G(ctx).Debug("Calling proc (2)")
err = getLayerMountPath(&stdDriverInfo, path, &mountPathLength, &mountPathp[0])
if err != nil {
return "", hcserror.New(err, title+" - failed", "(second call)")
}
mountPath := syscall.UTF16ToString(mountPathp[0:])
span.AddAttributes(trace.StringAttribute("mountPath", mountPath))
return mountPath, nil
}