diff options
Diffstat (limited to 'pkg/sentry/vfs/mount.go')
| -rw-r--r-- | pkg/sentry/vfs/mount.go | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/pkg/sentry/vfs/mount.go b/pkg/sentry/vfs/mount.go index 09fea3628..cd5456eef 100644 --- a/pkg/sentry/vfs/mount.go +++ b/pkg/sentry/vfs/mount.go @@ -18,12 +18,14 @@ import ( "bytes" "fmt" "math" + "path" "sort" "strings" "sync/atomic" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/fspath" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/syserror" ) @@ -888,6 +890,30 @@ func (vfs *VirtualFilesystem) GenerateProcMountInfo(ctx context.Context, taskRoo } } +// MakeSyntheticMountpoint creates parent directories of target if they do not +// exist and attempts to create a directory for the mountpoint. If a +// non-directory file already exists there then we allow it. +func (vfs *VirtualFilesystem) MakeSyntheticMountpoint(ctx context.Context, target string, root VirtualDentry, creds *auth.Credentials) error { + mkdirOpts := &MkdirOptions{Mode: 0777, ForSyntheticMountpoint: true} + + // Make sure the parent directory of target exists. + if err := vfs.MkdirAllAt(ctx, path.Dir(target), root, creds, mkdirOpts); err != nil { + return fmt.Errorf("failed to create parent directory of mountpoint %q: %w", target, err) + } + + // Attempt to mkdir the final component. If a file (of any type) exists + // then we let allow mounting on top of that because we do not require the + // target to be an existing directory, unlike Linux mount(2). + if err := vfs.MkdirAt(ctx, creds, &PathOperation{ + Root: root, + Start: root, + Path: fspath.Parse(target), + }, mkdirOpts); err != nil && err != syserror.EEXIST { + return fmt.Errorf("failed to create mountpoint %q: %w", target, err) + } + return nil +} + // manglePath replaces ' ', '\t', '\n', and '\\' with their octal equivalents. // See Linux fs/seq_file.c:mangle_path. func manglePath(p string) string { |