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Diffstat (limited to 'pkg/sentry/vfs/vfs.go')
-rw-r--r--pkg/sentry/vfs/vfs.go268
1 files changed, 167 insertions, 101 deletions
diff --git a/pkg/sentry/vfs/vfs.go b/pkg/sentry/vfs/vfs.go
index 58c7ad778..5bd756ea5 100644
--- a/pkg/sentry/vfs/vfs.go
+++ b/pkg/sentry/vfs/vfs.go
@@ -24,9 +24,9 @@
// Locks acquired by FilesystemImpls between Prepare{Delete,Rename}Dentry and Commit{Delete,Rename*}Dentry
// VirtualFilesystem.filesystemsMu
// EpollInstance.mu
-// Inotify.mu
-// Watches.mu
-// Inotify.evMu
+// Inotify.mu
+// Watches.mu
+// Inotify.evMu
// VirtualFilesystem.fsTypesMu
//
// Locking Dentry.mu in multiple Dentries requires holding
@@ -36,6 +36,7 @@ package vfs
import (
"fmt"
+ "path"
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/context"
@@ -122,7 +123,10 @@ type VirtualFilesystem struct {
}
// Init initializes a new VirtualFilesystem with no mounts or FilesystemTypes.
-func (vfs *VirtualFilesystem) Init() error {
+func (vfs *VirtualFilesystem) Init(ctx context.Context) error {
+ if vfs.mountpoints != nil {
+ panic("VFS already initialized")
+ }
vfs.mountpoints = make(map[*Dentry]map[*Mount]struct{})
vfs.devices = make(map[devTuple]*registeredDevice)
vfs.anonBlockDevMinorNext = 1
@@ -142,7 +146,7 @@ func (vfs *VirtualFilesystem) Init() error {
devMinor: anonfsDevMinor,
}
anonfs.vfsfs.Init(vfs, &anonFilesystemType{}, &anonfs)
- defer anonfs.vfsfs.DecRef()
+ defer anonfs.vfsfs.DecRef(ctx)
anonMount, err := vfs.NewDisconnectedMount(&anonfs.vfsfs, nil, &MountOptions{})
if err != nil {
// We should not be passing any MountOptions that would cause
@@ -159,6 +163,8 @@ func (vfs *VirtualFilesystem) Init() error {
// PathOperation is passed to VFS methods by pointer to reduce memory copying:
// it's somewhat large and should never escape. (Options structs are passed by
// pointer to VFS and FileDescription methods for the same reason.)
+//
+// +stateify savable
type PathOperation struct {
// Root is the VFS root. References on Root are borrowed from the provider
// of the PathOperation.
@@ -189,11 +195,11 @@ func (vfs *VirtualFilesystem) AccessAt(ctx context.Context, creds *auth.Credenti
for {
err := rp.mount.fs.impl.AccessAt(ctx, rp, creds, ats)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return nil
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return err
}
}
@@ -211,11 +217,11 @@ func (vfs *VirtualFilesystem) GetDentryAt(ctx context.Context, creds *auth.Crede
dentry: d,
}
rp.mount.IncRef()
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return vd, nil
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return VirtualDentry{}, err
}
}
@@ -233,7 +239,7 @@ func (vfs *VirtualFilesystem) getParentDirAndName(ctx context.Context, creds *au
}
rp.mount.IncRef()
name := rp.Component()
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return parentVD, name, nil
}
if checkInvariants {
@@ -241,8 +247,8 @@ func (vfs *VirtualFilesystem) getParentDirAndName(ctx context.Context, creds *au
panic(fmt.Sprintf("%T.GetParentDentryAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return VirtualDentry{}, "", err
}
}
@@ -257,14 +263,14 @@ func (vfs *VirtualFilesystem) LinkAt(ctx context.Context, creds *auth.Credential
}
if !newpop.Path.Begin.Ok() {
- oldVD.DecRef()
+ oldVD.DecRef(ctx)
if newpop.Path.Absolute {
return syserror.EEXIST
}
return syserror.ENOENT
}
if newpop.FollowFinalSymlink {
- oldVD.DecRef()
+ oldVD.DecRef(ctx)
ctx.Warningf("VirtualFilesystem.LinkAt: file creation paths can't follow final symlink")
return syserror.EINVAL
}
@@ -273,8 +279,8 @@ func (vfs *VirtualFilesystem) LinkAt(ctx context.Context, creds *auth.Credential
for {
err := rp.mount.fs.impl.LinkAt(ctx, rp, oldVD)
if err == nil {
- vfs.putResolvingPath(rp)
- oldVD.DecRef()
+ vfs.putResolvingPath(ctx, rp)
+ oldVD.DecRef(ctx)
return nil
}
if checkInvariants {
@@ -282,9 +288,9 @@ func (vfs *VirtualFilesystem) LinkAt(ctx context.Context, creds *auth.Credential
panic(fmt.Sprintf("%T.LinkAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
- oldVD.DecRef()
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
+ oldVD.DecRef(ctx)
return err
}
}
@@ -293,6 +299,8 @@ func (vfs *VirtualFilesystem) LinkAt(ctx context.Context, creds *auth.Credential
// MkdirAt creates a directory at the given path.
func (vfs *VirtualFilesystem) MkdirAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *MkdirOptions) error {
if !pop.Path.Begin.Ok() {
+ // pop.Path should not be empty in operations that create/delete files.
+ // This is consistent with mkdirat(dirfd, "", mode).
if pop.Path.Absolute {
return syserror.EEXIST
}
@@ -310,7 +318,7 @@ func (vfs *VirtualFilesystem) MkdirAt(ctx context.Context, creds *auth.Credentia
for {
err := rp.mount.fs.impl.MkdirAt(ctx, rp, *opts)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return nil
}
if checkInvariants {
@@ -318,8 +326,8 @@ func (vfs *VirtualFilesystem) MkdirAt(ctx context.Context, creds *auth.Credentia
panic(fmt.Sprintf("%T.MkdirAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return err
}
}
@@ -329,6 +337,8 @@ func (vfs *VirtualFilesystem) MkdirAt(ctx context.Context, creds *auth.Credentia
// error from the syserror package.
func (vfs *VirtualFilesystem) MknodAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *MknodOptions) error {
if !pop.Path.Begin.Ok() {
+ // pop.Path should not be empty in operations that create/delete files.
+ // This is consistent with mknodat(dirfd, "", mode, dev).
if pop.Path.Absolute {
return syserror.EEXIST
}
@@ -343,7 +353,7 @@ func (vfs *VirtualFilesystem) MknodAt(ctx context.Context, creds *auth.Credentia
for {
err := rp.mount.fs.impl.MknodAt(ctx, rp, *opts)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return nil
}
if checkInvariants {
@@ -351,8 +361,8 @@ func (vfs *VirtualFilesystem) MknodAt(ctx context.Context, creds *auth.Credentia
panic(fmt.Sprintf("%T.MknodAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return err
}
}
@@ -405,31 +415,31 @@ func (vfs *VirtualFilesystem) OpenAt(ctx context.Context, creds *auth.Credential
for {
fd, err := rp.mount.fs.impl.OpenAt(ctx, rp, *opts)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
if opts.FileExec {
if fd.Mount().Flags.NoExec {
- fd.DecRef()
+ fd.DecRef(ctx)
return nil, syserror.EACCES
}
// Only a regular file can be executed.
stat, err := fd.Stat(ctx, StatOptions{Mask: linux.STATX_TYPE})
if err != nil {
- fd.DecRef()
+ fd.DecRef(ctx)
return nil, err
}
if stat.Mask&linux.STATX_TYPE == 0 || stat.Mode&linux.S_IFMT != linux.S_IFREG {
- fd.DecRef()
+ fd.DecRef(ctx)
return nil, syserror.EACCES
}
}
- fd.Dentry().InotifyWithParent(linux.IN_OPEN, 0, PathEvent)
+ fd.Dentry().InotifyWithParent(ctx, linux.IN_OPEN, 0, PathEvent)
return fd, nil
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return nil, err
}
}
@@ -441,11 +451,11 @@ func (vfs *VirtualFilesystem) ReadlinkAt(ctx context.Context, creds *auth.Creden
for {
target, err := rp.mount.fs.impl.ReadlinkAt(ctx, rp)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return target, nil
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return "", err
}
}
@@ -469,19 +479,19 @@ func (vfs *VirtualFilesystem) RenameAt(ctx context.Context, creds *auth.Credenti
return err
}
if oldName == "." || oldName == ".." {
- oldParentVD.DecRef()
+ oldParentVD.DecRef(ctx)
return syserror.EBUSY
}
if !newpop.Path.Begin.Ok() {
- oldParentVD.DecRef()
+ oldParentVD.DecRef(ctx)
if newpop.Path.Absolute {
return syserror.EBUSY
}
return syserror.ENOENT
}
if newpop.FollowFinalSymlink {
- oldParentVD.DecRef()
+ oldParentVD.DecRef(ctx)
ctx.Warningf("VirtualFilesystem.RenameAt: destination path can't follow final symlink")
return syserror.EINVAL
}
@@ -494,8 +504,8 @@ func (vfs *VirtualFilesystem) RenameAt(ctx context.Context, creds *auth.Credenti
for {
err := rp.mount.fs.impl.RenameAt(ctx, rp, oldParentVD, oldName, renameOpts)
if err == nil {
- vfs.putResolvingPath(rp)
- oldParentVD.DecRef()
+ vfs.putResolvingPath(ctx, rp)
+ oldParentVD.DecRef(ctx)
return nil
}
if checkInvariants {
@@ -503,9 +513,9 @@ func (vfs *VirtualFilesystem) RenameAt(ctx context.Context, creds *auth.Credenti
panic(fmt.Sprintf("%T.RenameAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
- oldParentVD.DecRef()
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
+ oldParentVD.DecRef(ctx)
return err
}
}
@@ -514,6 +524,8 @@ func (vfs *VirtualFilesystem) RenameAt(ctx context.Context, creds *auth.Credenti
// RmdirAt removes the directory at the given path.
func (vfs *VirtualFilesystem) RmdirAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation) error {
if !pop.Path.Begin.Ok() {
+ // pop.Path should not be empty in operations that create/delete files.
+ // This is consistent with unlinkat(dirfd, "", AT_REMOVEDIR).
if pop.Path.Absolute {
return syserror.EBUSY
}
@@ -528,7 +540,7 @@ func (vfs *VirtualFilesystem) RmdirAt(ctx context.Context, creds *auth.Credentia
for {
err := rp.mount.fs.impl.RmdirAt(ctx, rp)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return nil
}
if checkInvariants {
@@ -536,8 +548,8 @@ func (vfs *VirtualFilesystem) RmdirAt(ctx context.Context, creds *auth.Credentia
panic(fmt.Sprintf("%T.RmdirAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return err
}
}
@@ -549,11 +561,11 @@ func (vfs *VirtualFilesystem) SetStatAt(ctx context.Context, creds *auth.Credent
for {
err := rp.mount.fs.impl.SetStatAt(ctx, rp, *opts)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return nil
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return err
}
}
@@ -565,11 +577,11 @@ func (vfs *VirtualFilesystem) StatAt(ctx context.Context, creds *auth.Credential
for {
stat, err := rp.mount.fs.impl.StatAt(ctx, rp, *opts)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return stat, nil
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return linux.Statx{}, err
}
}
@@ -582,11 +594,11 @@ func (vfs *VirtualFilesystem) StatFSAt(ctx context.Context, creds *auth.Credenti
for {
statfs, err := rp.mount.fs.impl.StatFSAt(ctx, rp)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return statfs, nil
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return linux.Statfs{}, err
}
}
@@ -595,6 +607,8 @@ func (vfs *VirtualFilesystem) StatFSAt(ctx context.Context, creds *auth.Credenti
// SymlinkAt creates a symbolic link at the given path with the given target.
func (vfs *VirtualFilesystem) SymlinkAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, target string) error {
if !pop.Path.Begin.Ok() {
+ // pop.Path should not be empty in operations that create/delete files.
+ // This is consistent with symlinkat(oldpath, newdirfd, "").
if pop.Path.Absolute {
return syserror.EEXIST
}
@@ -609,7 +623,7 @@ func (vfs *VirtualFilesystem) SymlinkAt(ctx context.Context, creds *auth.Credent
for {
err := rp.mount.fs.impl.SymlinkAt(ctx, rp, target)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return nil
}
if checkInvariants {
@@ -617,8 +631,8 @@ func (vfs *VirtualFilesystem) SymlinkAt(ctx context.Context, creds *auth.Credent
panic(fmt.Sprintf("%T.SymlinkAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return err
}
}
@@ -627,6 +641,8 @@ func (vfs *VirtualFilesystem) SymlinkAt(ctx context.Context, creds *auth.Credent
// UnlinkAt deletes the non-directory file at the given path.
func (vfs *VirtualFilesystem) UnlinkAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation) error {
if !pop.Path.Begin.Ok() {
+ // pop.Path should not be empty in operations that create/delete files.
+ // This is consistent with unlinkat(dirfd, "", 0).
if pop.Path.Absolute {
return syserror.EBUSY
}
@@ -641,7 +657,7 @@ func (vfs *VirtualFilesystem) UnlinkAt(ctx context.Context, creds *auth.Credenti
for {
err := rp.mount.fs.impl.UnlinkAt(ctx, rp)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return nil
}
if checkInvariants {
@@ -649,8 +665,8 @@ func (vfs *VirtualFilesystem) UnlinkAt(ctx context.Context, creds *auth.Credenti
panic(fmt.Sprintf("%T.UnlinkAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return err
}
}
@@ -658,17 +674,11 @@ func (vfs *VirtualFilesystem) UnlinkAt(ctx context.Context, creds *auth.Credenti
// BoundEndpointAt gets the bound endpoint at the given path, if one exists.
func (vfs *VirtualFilesystem) BoundEndpointAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *BoundEndpointOptions) (transport.BoundEndpoint, error) {
- if !pop.Path.Begin.Ok() {
- if pop.Path.Absolute {
- return nil, syserror.ECONNREFUSED
- }
- return nil, syserror.ENOENT
- }
rp := vfs.getResolvingPath(creds, pop)
for {
bep, err := rp.mount.fs.impl.BoundEndpointAt(ctx, rp, *opts)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return bep, nil
}
if checkInvariants {
@@ -676,21 +686,21 @@ func (vfs *VirtualFilesystem) BoundEndpointAt(ctx context.Context, creds *auth.C
panic(fmt.Sprintf("%T.BoundEndpointAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return nil, err
}
}
}
-// ListxattrAt returns all extended attribute names for the file at the given
+// ListXattrAt returns all extended attribute names for the file at the given
// path.
-func (vfs *VirtualFilesystem) ListxattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, size uint64) ([]string, error) {
+func (vfs *VirtualFilesystem) ListXattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, size uint64) ([]string, error) {
rp := vfs.getResolvingPath(creds, pop)
for {
- names, err := rp.mount.fs.impl.ListxattrAt(ctx, rp, size)
+ names, err := rp.mount.fs.impl.ListXattrAt(ctx, rp, size)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return names, nil
}
if err == syserror.ENOTSUP {
@@ -698,61 +708,61 @@ func (vfs *VirtualFilesystem) ListxattrAt(ctx context.Context, creds *auth.Crede
// fs/xattr.c:vfs_listxattr() falls back to allowing the security
// subsystem to return security extended attributes, which by
// default don't exist.
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return nil, nil
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return nil, err
}
}
}
-// GetxattrAt returns the value associated with the given extended attribute
+// GetXattrAt returns the value associated with the given extended attribute
// for the file at the given path.
-func (vfs *VirtualFilesystem) GetxattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *GetxattrOptions) (string, error) {
+func (vfs *VirtualFilesystem) GetXattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *GetXattrOptions) (string, error) {
rp := vfs.getResolvingPath(creds, pop)
for {
- val, err := rp.mount.fs.impl.GetxattrAt(ctx, rp, *opts)
+ val, err := rp.mount.fs.impl.GetXattrAt(ctx, rp, *opts)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return val, nil
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return "", err
}
}
}
-// SetxattrAt changes the value associated with the given extended attribute
+// SetXattrAt changes the value associated with the given extended attribute
// for the file at the given path.
-func (vfs *VirtualFilesystem) SetxattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *SetxattrOptions) error {
+func (vfs *VirtualFilesystem) SetXattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *SetXattrOptions) error {
rp := vfs.getResolvingPath(creds, pop)
for {
- err := rp.mount.fs.impl.SetxattrAt(ctx, rp, *opts)
+ err := rp.mount.fs.impl.SetXattrAt(ctx, rp, *opts)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return nil
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return err
}
}
}
-// RemovexattrAt removes the given extended attribute from the file at rp.
-func (vfs *VirtualFilesystem) RemovexattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, name string) error {
+// RemoveXattrAt removes the given extended attribute from the file at rp.
+func (vfs *VirtualFilesystem) RemoveXattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, name string) error {
rp := vfs.getResolvingPath(creds, pop)
for {
- err := rp.mount.fs.impl.RemovexattrAt(ctx, rp, name)
+ err := rp.mount.fs.impl.RemoveXattrAt(ctx, rp, name)
if err == nil {
- vfs.putResolvingPath(rp)
+ vfs.putResolvingPath(ctx, rp)
return nil
}
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
+ if !rp.handleError(ctx, err) {
+ vfs.putResolvingPath(ctx, rp)
return err
}
}
@@ -774,11 +784,67 @@ func (vfs *VirtualFilesystem) SyncAllFilesystems(ctx context.Context) error {
if err := fs.impl.Sync(ctx); err != nil && retErr == nil {
retErr = err
}
- fs.DecRef()
+ fs.DecRef(ctx)
}
return retErr
}
+// MkdirAllAt recursively creates non-existent directories on the given path
+// (including the last component).
+func (vfs *VirtualFilesystem) MkdirAllAt(ctx context.Context, currentPath string, root VirtualDentry, creds *auth.Credentials, mkdirOpts *MkdirOptions) error {
+ pop := &PathOperation{
+ Root: root,
+ Start: root,
+ Path: fspath.Parse(currentPath),
+ }
+ stat, err := vfs.StatAt(ctx, creds, pop, &StatOptions{Mask: linux.STATX_TYPE})
+ switch err {
+ case nil:
+ if stat.Mask&linux.STATX_TYPE == 0 || stat.Mode&linux.FileTypeMask != linux.ModeDirectory {
+ return syserror.ENOTDIR
+ }
+ // Directory already exists.
+ return nil
+ case syserror.ENOENT:
+ // Expected, we will create the dir.
+ default:
+ return fmt.Errorf("stat failed for %q during directory creation: %w", currentPath, err)
+ }
+
+ // Recurse to ensure parent is created and then create the final directory.
+ if err := vfs.MkdirAllAt(ctx, path.Dir(currentPath), root, creds, mkdirOpts); err != nil {
+ return err
+ }
+ if err := vfs.MkdirAt(ctx, creds, pop, mkdirOpts); err != nil {
+ return fmt.Errorf("failed to create directory %q: %w", currentPath, err)
+ }
+ return nil
+}
+
+// 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
+}
+
// A VirtualDentry represents a node in a VFS tree, by combining a Dentry
// (which represents a node in a Filesystem's tree) and a Mount (which
// represents the Filesystem's position in a VFS mount tree).
@@ -828,9 +894,9 @@ func (vd VirtualDentry) IncRef() {
// DecRef decrements the reference counts on the Mount and Dentry represented
// by vd.
-func (vd VirtualDentry) DecRef() {
- vd.dentry.DecRef()
- vd.mount.DecRef()
+func (vd VirtualDentry) DecRef(ctx context.Context) {
+ vd.dentry.DecRef(ctx)
+ vd.mount.DecRef(ctx)
}
// Mount returns the Mount associated with vd. It does not take a reference on