c8d/mount: Use ref-counted mounter by default

All commonly used filesystems should use ref-counted mounter, so make it
the default instead of having to whitelist them.

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
This commit is contained in:
Paweł Gronowski 2024-01-18 14:23:32 +01:00
parent 4f9c865edd
commit ae6468b4b9
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@ -13,9 +13,6 @@ import (
"github.com/moby/sys/mountinfo" "github.com/moby/sys/mountinfo"
) )
// List of known filesystems that can't be re-mounted or have shared layers
var refCountedFileSystems = []string{"fuse-overlayfs", "overlayfs", "stargz", "zfs"}
// Mounter handles mounting/unmounting things coming in from a snapshotter // Mounter handles mounting/unmounting things coming in from a snapshotter
// with optional reference counting if needed by the filesystem // with optional reference counting if needed by the filesystem
type Mounter interface { type Mounter interface {
@ -27,34 +24,17 @@ type Mounter interface {
Mounted(containerID string) (string, error) Mounted(containerID string) (string, error)
} }
// inSlice tests whether a string is contained in a slice of strings or not.
// Comparison is case sensitive
func inSlice(slice []string, s string) bool {
for _, ss := range slice {
if s == ss {
return true
}
}
return false
}
// NewMounter creates a new mounter for the provided snapshotter // NewMounter creates a new mounter for the provided snapshotter
func NewMounter(home string, snapshotter string, idMap idtools.IdentityMapping) Mounter { func NewMounter(home string, snapshotter string, idMap idtools.IdentityMapping) *refCountMounter {
mnter := mounter{ return &refCountMounter{
base: mounter{
home: home, home: home,
snapshotter: snapshotter, snapshotter: snapshotter,
idMap: idMap, idMap: idMap,
} },
if inSlice(refCountedFileSystems, snapshotter) {
return &refCountMounter{
base: mnter,
rc: graphdriver.NewRefCounter(checker()), rc: graphdriver.NewRefCounter(checker()),
locker: locker.New(), locker: locker.New(),
} }
}
return &mnter
} }
type refCountMounter struct { type refCountMounter struct {