mirror of
https://github.com/hanzoai/visor.git
synced 2026-09-24 17:04:14 +00:00
Etienne Perot
62eb61a0e6
`runsc boot` still works, so single-file installations continue to work for now. No statistically significant change in startup latency, but unlocks the ability to do per-platform PGO.
89 lines
2.5 KiB
Go
89 lines
2.5 KiB
Go
// Copyright 2022 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package sentrycmd
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import (
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"context"
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"os"
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"syscall"
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"unsafe"
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"github.com/google/subcommands"
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specs "github.com/opencontainers/runtime-spec/specs-go"
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"golang.org/x/sys/unix"
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"gvisor.dev/gvisor/pkg/abi/linux"
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"gvisor.dev/gvisor/runsc/cmd/util"
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"gvisor.dev/gvisor/runsc/config"
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"gvisor.dev/gvisor/runsc/flag"
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)
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// Umount implements subcommands.Command for the "umount" command.
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type Umount struct {
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syncFD int
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}
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// Name implements subcommands.Command.Name.
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func (*Umount) Name() string {
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return "umount"
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}
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// Synopsis implements subcommands.Command.Synopsis.
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func (*Umount) Synopsis() string {
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return "umount the specified directory lazily when one byte is read from sync-fd"
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}
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// Usage implements subcommands.Command.Usage.
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func (*Umount) Usage() string {
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return "umount --sync-fd=FD <directory path>\n"
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}
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// SetFlags implements subcommands.Command.SetFlags.
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func (u *Umount) SetFlags(f *flag.FlagSet) {
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f.IntVar(&u.syncFD, "sync-fd", -1, "")
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}
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// FetchSpec implements util.SubCommand.FetchSpec.
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func (u *Umount) FetchSpec(conf *config.Config, f *flag.FlagSet) (string, *specs.Spec, error) {
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// This command does not operate on a single container, so nothing to fetch.
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return "", nil, nil
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}
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// Execute implements subcommands.Command.Execute.
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func (u *Umount) Execute(_ context.Context, f *flag.FlagSet, args ...any) subcommands.ExitStatus {
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if f.NArg() == 0 || f.NArg() > 1 {
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f.Usage()
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return subcommands.ExitUsageError
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}
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dirPath := f.Arg(0)
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syncFile := os.NewFile(uintptr(u.syncFD), "sync file")
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defer syncFile.Close()
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buf := make([]byte, 1)
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if l, err := syncFile.Read(buf); err != nil || l != 1 {
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util.Fatalf("unable to read from the sync descriptor: %v, error %v", l, err)
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}
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if _, _, errno := unix.RawSyscall(
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unix.SYS_UMOUNT2,
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uintptr(unsafe.Pointer(syscall.StringBytePtr(dirPath))),
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uintptr(linux.MNT_DETACH), 0); errno != 0 {
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util.Fatalf("Unable to umount %s: errno %v", dirPath, errno)
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}
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return subcommands.ExitSuccess
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}
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