summaryrefslogtreecommitdiffhomepage
path: root/pkg/sentry/fsimpl/overlay
diff options
context:
space:
mode:
Diffstat (limited to 'pkg/sentry/fsimpl/overlay')
-rw-r--r--pkg/sentry/fsimpl/overlay/BUILD1
-rw-r--r--pkg/sentry/fsimpl/overlay/copy_up.go12
-rw-r--r--pkg/sentry/fsimpl/overlay/filesystem.go53
3 files changed, 40 insertions, 26 deletions
diff --git a/pkg/sentry/fsimpl/overlay/BUILD b/pkg/sentry/fsimpl/overlay/BUILD
index ed730e215..d16dfef9b 100644
--- a/pkg/sentry/fsimpl/overlay/BUILD
+++ b/pkg/sentry/fsimpl/overlay/BUILD
@@ -42,7 +42,6 @@ go_library(
"//pkg/sentry/socket/unix/transport",
"//pkg/sentry/vfs",
"//pkg/sync",
- "//pkg/syserror",
"//pkg/usermem",
"//pkg/waiter",
],
diff --git a/pkg/sentry/fsimpl/overlay/copy_up.go b/pkg/sentry/fsimpl/overlay/copy_up.go
index 1f85a1f0d..520487066 100644
--- a/pkg/sentry/fsimpl/overlay/copy_up.go
+++ b/pkg/sentry/fsimpl/overlay/copy_up.go
@@ -26,7 +26,6 @@ import (
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/memmap"
"gvisor.dev/gvisor/pkg/sentry/vfs"
- "gvisor.dev/gvisor/pkg/syserror"
)
func (d *dentry) isCopiedUp() bool {
@@ -37,6 +36,10 @@ func (d *dentry) isCopiedUp() bool {
//
// Preconditions: filesystem.renameMu must be locked.
func (d *dentry) copyUpLocked(ctx context.Context) error {
+ return d.copyUpMaybeSyntheticMountpointLocked(ctx, false /* forSyntheticMountpoint */)
+}
+
+func (d *dentry) copyUpMaybeSyntheticMountpointLocked(ctx context.Context, forSyntheticMountpoint bool) error {
// Fast path.
if d.isCopiedUp() {
return nil
@@ -60,7 +63,7 @@ func (d *dentry) copyUpLocked(ctx context.Context) error {
// d is a filesystem root with no upper layer.
return linuxerr.EROFS
}
- if err := d.parent.copyUpLocked(ctx); err != nil {
+ if err := d.parent.copyUpMaybeSyntheticMountpointLocked(ctx, forSyntheticMountpoint); err != nil {
return err
}
@@ -72,7 +75,7 @@ func (d *dentry) copyUpLocked(ctx context.Context) error {
}
if d.vfsd.IsDead() {
// Raced with deletion of d.
- return syserror.ENOENT
+ return linuxerr.ENOENT
}
// Obtain settable timestamps from the lower layer.
@@ -169,7 +172,8 @@ func (d *dentry) copyUpLocked(ctx context.Context) error {
case linux.S_IFDIR:
if err := vfsObj.MkdirAt(ctx, d.fs.creds, &newpop, &vfs.MkdirOptions{
- Mode: linux.FileMode(d.mode &^ linux.S_IFMT),
+ Mode: linux.FileMode(d.mode &^ linux.S_IFMT),
+ ForSyntheticMountpoint: forSyntheticMountpoint,
}); err != nil {
return err
}
diff --git a/pkg/sentry/fsimpl/overlay/filesystem.go b/pkg/sentry/fsimpl/overlay/filesystem.go
index 5e89928c5..3b3dcf836 100644
--- a/pkg/sentry/fsimpl/overlay/filesystem.go
+++ b/pkg/sentry/fsimpl/overlay/filesystem.go
@@ -28,7 +28,6 @@ import (
"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
"gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/sync"
- "gvisor.dev/gvisor/pkg/syserror"
)
// _OVL_XATTR_PREFIX is an extended attribute key prefix to identify overlayfs
@@ -314,7 +313,7 @@ func (fs *filesystem) lookupLocked(ctx context.Context, parent *dentry, name str
}
if !topLookupLayer.existsInOverlay() {
child.destroyLocked(ctx)
- return nil, topLookupLayer, syserror.ENOENT
+ return nil, topLookupLayer, linuxerr.ENOENT
}
// Device and inode numbers were copied from the topmost layer above. Remap
@@ -463,13 +462,21 @@ func (fs *filesystem) resolveLocked(ctx context.Context, rp *vfs.ResolvingPath,
return d, nil
}
+type createType int
+
+const (
+ createNonDirectory createType = iota
+ createDirectory
+ createSyntheticMountpoint
+)
+
// doCreateAt checks that creating a file at rp is permitted, then invokes
// create to do so.
//
// Preconditions:
// * !rp.Done().
// * For the final path component in rp, !rp.ShouldFollowSymlink().
-func (fs *filesystem) doCreateAt(ctx context.Context, rp *vfs.ResolvingPath, dir bool, create func(parent *dentry, name string, haveUpperWhiteout bool) error) error {
+func (fs *filesystem) doCreateAt(ctx context.Context, rp *vfs.ResolvingPath, ct createType, create func(parent *dentry, name string, haveUpperWhiteout bool) error) error {
var ds *[]*dentry
fs.renameMu.RLock()
defer fs.renameMuRUnlockAndCheckDrop(ctx, &ds)
@@ -483,7 +490,7 @@ func (fs *filesystem) doCreateAt(ctx context.Context, rp *vfs.ResolvingPath, dir
return linuxerr.EEXIST
}
if parent.vfsd.IsDead() {
- return syserror.ENOENT
+ return linuxerr.ENOENT
}
if err := parent.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
@@ -505,8 +512,8 @@ func (fs *filesystem) doCreateAt(ctx context.Context, rp *vfs.ResolvingPath, dir
return linuxerr.EEXIST
}
- if !dir && rp.MustBeDir() {
- return syserror.ENOENT
+ if ct == createNonDirectory && rp.MustBeDir() {
+ return linuxerr.ENOENT
}
mnt := rp.Mount()
@@ -519,7 +526,7 @@ func (fs *filesystem) doCreateAt(ctx context.Context, rp *vfs.ResolvingPath, dir
}
// Ensure that the parent directory is copied-up so that we can create the
// new file in the upper layer.
- if err := parent.copyUpLocked(ctx); err != nil {
+ if err := parent.copyUpMaybeSyntheticMountpointLocked(ctx, ct == createSyntheticMountpoint); err != nil {
return err
}
@@ -530,7 +537,7 @@ func (fs *filesystem) doCreateAt(ctx context.Context, rp *vfs.ResolvingPath, dir
parent.dirents = nil
ev := linux.IN_CREATE
- if dir {
+ if ct != createNonDirectory {
ev |= linux.IN_ISDIR
}
parent.watches.Notify(ctx, name, uint32(ev), 0 /* cookie */, vfs.InodeEvent, false /* unlinked */)
@@ -619,7 +626,7 @@ func (fs *filesystem) GetParentDentryAt(ctx context.Context, rp *vfs.ResolvingPa
// LinkAt implements vfs.FilesystemImpl.LinkAt.
func (fs *filesystem) LinkAt(ctx context.Context, rp *vfs.ResolvingPath, vd vfs.VirtualDentry) error {
- return fs.doCreateAt(ctx, rp, false /* dir */, func(parent *dentry, childName string, haveUpperWhiteout bool) error {
+ return fs.doCreateAt(ctx, rp, createNonDirectory, func(parent *dentry, childName string, haveUpperWhiteout bool) error {
if rp.Mount() != vd.Mount() {
return linuxerr.EXDEV
}
@@ -672,7 +679,11 @@ func (fs *filesystem) LinkAt(ctx context.Context, rp *vfs.ResolvingPath, vd vfs.
// MkdirAt implements vfs.FilesystemImpl.MkdirAt.
func (fs *filesystem) MkdirAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.MkdirOptions) error {
- return fs.doCreateAt(ctx, rp, true /* dir */, func(parent *dentry, childName string, haveUpperWhiteout bool) error {
+ ct := createDirectory
+ if opts.ForSyntheticMountpoint {
+ ct = createSyntheticMountpoint
+ }
+ return fs.doCreateAt(ctx, rp, ct, func(parent *dentry, childName string, haveUpperWhiteout bool) error {
vfsObj := fs.vfsfs.VirtualFilesystem()
pop := vfs.PathOperation{
Root: parent.upperVD,
@@ -723,7 +734,7 @@ func (fs *filesystem) MkdirAt(ctx context.Context, rp *vfs.ResolvingPath, opts v
// MknodAt implements vfs.FilesystemImpl.MknodAt.
func (fs *filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.MknodOptions) error {
- return fs.doCreateAt(ctx, rp, false /* dir */, func(parent *dentry, childName string, haveUpperWhiteout bool) error {
+ return fs.doCreateAt(ctx, rp, createNonDirectory, func(parent *dentry, childName string, haveUpperWhiteout bool) error {
// Disallow attempts to create whiteouts.
if opts.Mode&linux.S_IFMT == linux.S_IFCHR && opts.DevMajor == 0 && opts.DevMinor == 0 {
return linuxerr.EPERM
@@ -780,7 +791,7 @@ func (fs *filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf
start := rp.Start().Impl().(*dentry)
if rp.Done() {
if mayCreate && rp.MustBeDir() {
- return nil, syserror.EISDIR
+ return nil, linuxerr.EISDIR
}
if mustCreate {
return nil, linuxerr.EEXIST
@@ -807,7 +818,7 @@ afterTrailingSymlink:
}
// Reject attempts to open directories with O_CREAT.
if mayCreate && rp.MustBeDir() {
- return nil, syserror.EISDIR
+ return nil, linuxerr.EISDIR
}
// Determine whether or not we need to create a file.
parent.dirMu.Lock()
@@ -865,11 +876,11 @@ func (d *dentry) openCopiedUp(ctx context.Context, rp *vfs.ResolvingPath, opts *
if ftype == linux.S_IFDIR {
// Can't open directories with O_CREAT.
if opts.Flags&linux.O_CREAT != 0 {
- return nil, syserror.EISDIR
+ return nil, linuxerr.EISDIR
}
// Can't open directories writably.
if ats.MayWrite() {
- return nil, syserror.EISDIR
+ return nil, linuxerr.EISDIR
}
if opts.Flags&linux.O_DIRECT != 0 {
return nil, linuxerr.EINVAL
@@ -919,7 +930,7 @@ func (fs *filesystem) createAndOpenLocked(ctx context.Context, rp *vfs.Resolving
return nil, err
}
if parent.vfsd.IsDead() {
- return nil, syserror.ENOENT
+ return nil, linuxerr.ENOENT
}
mnt := rp.Mount()
if err := mnt.CheckBeginWrite(); err != nil {
@@ -1086,7 +1097,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
defer newParent.dirMu.Unlock()
}
if newParent.vfsd.IsDead() {
- return syserror.ENOENT
+ return linuxerr.ENOENT
}
var (
replaced *dentry
@@ -1105,7 +1116,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
replacedVFSD = &replaced.vfsd
if replaced.isDir() {
if !renamed.isDir() {
- return syserror.EISDIR
+ return linuxerr.EISDIR
}
if genericIsAncestorDentry(replaced, renamed) {
return linuxerr.ENOTEMPTY
@@ -1477,7 +1488,7 @@ func (fs *filesystem) StatFSAt(ctx context.Context, rp *vfs.ResolvingPath) (linu
// SymlinkAt implements vfs.FilesystemImpl.SymlinkAt.
func (fs *filesystem) SymlinkAt(ctx context.Context, rp *vfs.ResolvingPath, target string) error {
- return fs.doCreateAt(ctx, rp, false /* dir */, func(parent *dentry, childName string, haveUpperWhiteout bool) error {
+ return fs.doCreateAt(ctx, rp, createNonDirectory, func(parent *dentry, childName string, haveUpperWhiteout bool) error {
vfsObj := fs.vfsfs.VirtualFilesystem()
pop := vfs.PathOperation{
Root: parent.upperVD,
@@ -1533,7 +1544,7 @@ func (fs *filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error
defer rp.Mount().EndWrite()
name := rp.Component()
if name == "." || name == ".." {
- return syserror.EISDIR
+ return linuxerr.EISDIR
}
if rp.MustBeDir() {
return linuxerr.ENOTDIR
@@ -1557,7 +1568,7 @@ func (fs *filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error
return err
}
if child.isDir() {
- return syserror.EISDIR
+ return linuxerr.EISDIR
}
if err := parent.mayDelete(rp.Credentials(), child); err != nil {
return err
generated by cgit v1.2.3 (git 2.39.1) at 2025-03-31 08:22:56 +0000