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path: root/pkg/sentry/fsimpl/kernfs/filesystem.go
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Diffstat (limited to 'pkg/sentry/fsimpl/kernfs/filesystem.go')
-rw-r--r--pkg/sentry/fsimpl/kernfs/filesystem.go123
1 files changed, 60 insertions, 63 deletions
diff --git a/pkg/sentry/fsimpl/kernfs/filesystem.go b/pkg/sentry/fsimpl/kernfs/filesystem.go
index daad1e04a..c2c62341d 100644
--- a/pkg/sentry/fsimpl/kernfs/filesystem.go
+++ b/pkg/sentry/fsimpl/kernfs/filesystem.go
@@ -37,8 +37,7 @@ import (
// * !rp.Done().
//
// Postcondition: Caller must call fs.processDeferredDecRefs*.
-func (fs *Filesystem) stepExistingLocked(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, mayFollowSymlinks bool) (*vfs.Dentry, error) {
- d := vfsd.Impl().(*Dentry)
+func (fs *Filesystem) stepExistingLocked(ctx context.Context, rp *vfs.ResolvingPath, d *Dentry, mayFollowSymlinks bool) (*Dentry, error) {
if !d.isDir() {
return nil, syserror.ENOTDIR
}
@@ -55,20 +54,20 @@ afterSymlink:
// calls d_revalidate(), but walk_component() => handle_dots() does not.
if name == "." {
rp.Advance()
- return vfsd, nil
+ return d, nil
}
if name == ".." {
- if isRoot, err := rp.CheckRoot(ctx, vfsd); err != nil {
+ if isRoot, err := rp.CheckRoot(ctx, d.VFSDentry()); err != nil {
return nil, err
} else if isRoot || d.parent == nil {
rp.Advance()
- return vfsd, nil
+ return d, nil
}
- if err := rp.CheckMount(ctx, &d.parent.vfsd); err != nil {
+ if err := rp.CheckMount(ctx, d.parent.VFSDentry()); err != nil {
return nil, err
}
rp.Advance()
- return &d.parent.vfsd, nil
+ return d.parent, nil
}
if len(name) > linux.NAME_MAX {
return nil, syserror.ENAMETOOLONG
@@ -79,7 +78,7 @@ afterSymlink:
if err != nil {
return nil, err
}
- if err := rp.CheckMount(ctx, &next.vfsd); err != nil {
+ if err := rp.CheckMount(ctx, next.VFSDentry()); err != nil {
return nil, err
}
// Resolve any symlink at current path component.
@@ -102,7 +101,7 @@ afterSymlink:
goto afterSymlink
}
rp.Advance()
- return &next.vfsd, nil
+ return next, nil
}
// revalidateChildLocked must be called after a call to parent.vfsd.Child(name)
@@ -122,7 +121,7 @@ func (fs *Filesystem) revalidateChildLocked(ctx context.Context, vfsObj *vfs.Vir
if !child.inode.Valid(ctx) {
delete(parent.children, name)
vfsObj.InvalidateDentry(ctx, &child.vfsd)
- fs.deferDecRef(&child.vfsd) // Reference from Lookup.
+ fs.deferDecRef(child) // Reference from Lookup.
child = nil
}
}
@@ -149,15 +148,14 @@ func (fs *Filesystem) revalidateChildLocked(ctx context.Context, vfsObj *vfs.Vir
//
// Postconditions: Caller must call fs.processDeferredDecRefs*.
func (fs *Filesystem) walkExistingLocked(ctx context.Context, rp *vfs.ResolvingPath) (*Dentry, error) {
- vfsd := rp.Start()
+ d := rp.Start().Impl().(*Dentry)
for !rp.Done() {
var err error
- vfsd, err = fs.stepExistingLocked(ctx, rp, vfsd, true /* mayFollowSymlinks */)
+ d, err = fs.stepExistingLocked(ctx, rp, d, true /* mayFollowSymlinks */)
if err != nil {
return nil, err
}
}
- d := vfsd.Impl().(*Dentry)
if rp.MustBeDir() && !d.isDir() {
return nil, syserror.ENOTDIR
}
@@ -176,20 +174,19 @@ func (fs *Filesystem) walkExistingLocked(ctx context.Context, rp *vfs.ResolvingP
// * !rp.Done().
//
// Postconditions: Caller must call fs.processDeferredDecRefs*.
-func (fs *Filesystem) walkParentDirLocked(ctx context.Context, rp *vfs.ResolvingPath) (*vfs.Dentry, Inode, error) {
- vfsd := rp.Start()
+func (fs *Filesystem) walkParentDirLocked(ctx context.Context, rp *vfs.ResolvingPath) (*Dentry, error) {
+ d := rp.Start().Impl().(*Dentry)
for !rp.Final() {
var err error
- vfsd, err = fs.stepExistingLocked(ctx, rp, vfsd, true /* mayFollowSymlinks */)
+ d, err = fs.stepExistingLocked(ctx, rp, d, true /* mayFollowSymlinks */)
if err != nil {
- return nil, nil, err
+ return nil, err
}
}
- d := vfsd.Impl().(*Dentry)
if !d.isDir() {
- return nil, nil, syserror.ENOTDIR
+ return nil, syserror.ENOTDIR
}
- return vfsd, d.inode, nil
+ return d, nil
}
// checkCreateLocked checks that a file named rp.Component() may be created in
@@ -197,10 +194,9 @@ func (fs *Filesystem) walkParentDirLocked(ctx context.Context, rp *vfs.Resolving
//
// Preconditions:
// * Filesystem.mu must be locked for at least reading.
-// * parentInode == parentVFSD.Impl().(*Dentry).Inode.
// * isDir(parentInode) == true.
-func checkCreateLocked(ctx context.Context, rp *vfs.ResolvingPath, parentVFSD *vfs.Dentry, parentInode Inode) (string, error) {
- if err := parentInode.CheckPermissions(ctx, rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
+func checkCreateLocked(ctx context.Context, rp *vfs.ResolvingPath, parent *Dentry) (string, error) {
+ if err := parent.inode.CheckPermissions(ctx, rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
return "", err
}
pc := rp.Component()
@@ -211,10 +207,10 @@ func checkCreateLocked(ctx context.Context, rp *vfs.ResolvingPath, parentVFSD *v
return "", syserror.ENAMETOOLONG
}
// FIXME(gvisor.dev/issue/1193): Data race due to not holding dirMu.
- if _, ok := parentVFSD.Impl().(*Dentry).children[pc]; ok {
+ if _, ok := parent.children[pc]; ok {
return "", syserror.EEXIST
}
- if parentVFSD.IsDead() {
+ if parent.VFSDentry().IsDead() {
return "", syserror.ENOENT
}
return pc, nil
@@ -288,12 +284,12 @@ func (fs *Filesystem) GetParentDentryAt(ctx context.Context, rp *vfs.ResolvingPa
fs.mu.RLock()
defer fs.processDeferredDecRefs(ctx)
defer fs.mu.RUnlock()
- vfsd, _, err := fs.walkParentDirLocked(ctx, rp)
+ d, err := fs.walkParentDirLocked(ctx, rp)
if err != nil {
return nil, err
}
- vfsd.IncRef() // Ownership transferred to caller.
- return vfsd, nil
+ d.IncRef() // Ownership transferred to caller.
+ return d.VFSDentry(), nil
}
// LinkAt implements vfs.FilesystemImpl.LinkAt.
@@ -303,12 +299,12 @@ func (fs *Filesystem) LinkAt(ctx context.Context, rp *vfs.ResolvingPath, vd vfs.
}
fs.mu.Lock()
defer fs.mu.Unlock()
- parentVFSD, parentInode, err := fs.walkParentDirLocked(ctx, rp)
+ parent, err := fs.walkParentDirLocked(ctx, rp)
fs.processDeferredDecRefsLocked(ctx)
if err != nil {
return err
}
- pc, err := checkCreateLocked(ctx, rp, parentVFSD, parentInode)
+ pc, err := checkCreateLocked(ctx, rp, parent)
if err != nil {
return err
}
@@ -325,11 +321,11 @@ func (fs *Filesystem) LinkAt(ctx context.Context, rp *vfs.ResolvingPath, vd vfs.
return syserror.EPERM
}
- childVFSD, err := parentInode.NewLink(ctx, pc, d.inode)
+ child, err := parent.inode.NewLink(ctx, pc, d.inode)
if err != nil {
return err
}
- parentVFSD.Impl().(*Dentry).InsertChild(pc, childVFSD.Impl().(*Dentry))
+ parent.InsertChild(pc, child)
return nil
}
@@ -340,12 +336,12 @@ func (fs *Filesystem) MkdirAt(ctx context.Context, rp *vfs.ResolvingPath, opts v
}
fs.mu.Lock()
defer fs.mu.Unlock()
- parentVFSD, parentInode, err := fs.walkParentDirLocked(ctx, rp)
+ parent, err := fs.walkParentDirLocked(ctx, rp)
fs.processDeferredDecRefsLocked(ctx)
if err != nil {
return err
}
- pc, err := checkCreateLocked(ctx, rp, parentVFSD, parentInode)
+ pc, err := checkCreateLocked(ctx, rp, parent)
if err != nil {
return err
}
@@ -353,14 +349,14 @@ func (fs *Filesystem) MkdirAt(ctx context.Context, rp *vfs.ResolvingPath, opts v
return err
}
defer rp.Mount().EndWrite()
- childVFSD, err := parentInode.NewDir(ctx, pc, opts)
+ child, err := parent.inode.NewDir(ctx, pc, opts)
if err != nil {
if !opts.ForSyntheticMountpoint || err == syserror.EEXIST {
return err
}
- childVFSD = newSyntheticDirectory(rp.Credentials(), opts.Mode)
+ child = newSyntheticDirectory(rp.Credentials(), opts.Mode)
}
- parentVFSD.Impl().(*Dentry).InsertChild(pc, childVFSD.Impl().(*Dentry))
+ parent.InsertChild(pc, child)
return nil
}
@@ -371,12 +367,12 @@ func (fs *Filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts v
}
fs.mu.Lock()
defer fs.mu.Unlock()
- parentVFSD, parentInode, err := fs.walkParentDirLocked(ctx, rp)
+ parent, err := fs.walkParentDirLocked(ctx, rp)
fs.processDeferredDecRefsLocked(ctx)
if err != nil {
return err
}
- pc, err := checkCreateLocked(ctx, rp, parentVFSD, parentInode)
+ pc, err := checkCreateLocked(ctx, rp, parent)
if err != nil {
return err
}
@@ -384,11 +380,11 @@ func (fs *Filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts v
return err
}
defer rp.Mount().EndWrite()
- newVFSD, err := parentInode.NewNode(ctx, pc, opts)
+ newD, err := parent.inode.NewNode(ctx, pc, opts)
if err != nil {
return err
}
- parentVFSD.Impl().(*Dentry).InsertChild(pc, newVFSD.Impl().(*Dentry))
+ parent.InsertChild(pc, newD)
return nil
}
@@ -450,13 +446,13 @@ func (fs *Filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf
return d.inode.Open(ctx, rp, d, opts)
}
afterTrailingSymlink:
- parentVFSD, parentInode, err := fs.walkParentDirLocked(ctx, rp)
+ parent, err := fs.walkParentDirLocked(ctx, rp)
fs.processDeferredDecRefsLocked(ctx)
if err != nil {
return nil, err
}
// Check for search permission in the parent directory.
- if err := parentInode.CheckPermissions(ctx, rp.Credentials(), vfs.MayExec); err != nil {
+ if err := parent.inode.CheckPermissions(ctx, rp.Credentials(), vfs.MayExec); err != nil {
return nil, err
}
// Reject attempts to open directories with O_CREAT.
@@ -471,10 +467,10 @@ afterTrailingSymlink:
return nil, syserror.ENAMETOOLONG
}
// Determine whether or not we need to create a file.
- childVFSD, err := fs.stepExistingLocked(ctx, rp, parentVFSD, false /* mayFollowSymlinks */)
+ child, err := fs.stepExistingLocked(ctx, rp, parent, false /* mayFollowSymlinks */)
if err == syserror.ENOENT {
// Already checked for searchability above; now check for writability.
- if err := parentInode.CheckPermissions(ctx, rp.Credentials(), vfs.MayWrite); err != nil {
+ if err := parent.inode.CheckPermissions(ctx, rp.Credentials(), vfs.MayWrite); err != nil {
return nil, err
}
if err := rp.Mount().CheckBeginWrite(); err != nil {
@@ -482,12 +478,11 @@ afterTrailingSymlink:
}
defer rp.Mount().EndWrite()
// Create and open the child.
- childVFSD, err = parentInode.NewFile(ctx, pc, opts)
+ child, err := parent.inode.NewFile(ctx, pc, opts)
if err != nil {
return nil, err
}
- child := childVFSD.Impl().(*Dentry)
- parentVFSD.Impl().(*Dentry).InsertChild(pc, child)
+ parent.InsertChild(pc, child)
child.inode.IncRef()
defer child.inode.DecRef(ctx)
unlock()
@@ -500,7 +495,6 @@ afterTrailingSymlink:
if mustCreate {
return nil, syserror.EEXIST
}
- child := childVFSD.Impl().(*Dentry)
if rp.ShouldFollowSymlink() && child.isSymlink() {
targetVD, targetPathname, err := child.inode.Getlink(ctx, rp.Mount())
if err != nil {
@@ -559,11 +553,10 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
// Resolve the destination directory first to verify that it's on this
// Mount.
- dstDirVFSD, dstDirInode, err := fs.walkParentDirLocked(ctx, rp)
+ dstDir, err := fs.walkParentDirLocked(ctx, rp)
if err != nil {
return err
}
- dstDir := dstDirVFSD.Impl().(*Dentry)
mnt := rp.Mount()
if mnt != oldParentVD.Mount() {
return syserror.EXDEV
@@ -589,7 +582,7 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
// Can we create the dst dentry?
var dst *Dentry
- pc, err := checkCreateLocked(ctx, rp, dstDirVFSD, dstDirInode)
+ pc, err := checkCreateLocked(ctx, rp, dstDir)
switch err {
case nil:
// Ok, continue with rename as replacement.
@@ -600,14 +593,14 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
}
dst = dstDir.children[pc]
if dst == nil {
- panic(fmt.Sprintf("Child %q for parent Dentry %+v disappeared inside atomic section?", pc, dstDirVFSD))
+ panic(fmt.Sprintf("Child %q for parent Dentry %+v disappeared inside atomic section?", pc, dstDir))
}
default:
return err
}
var dstVFSD *vfs.Dentry
if dst != nil {
- dstVFSD = &dst.vfsd
+ dstVFSD = dst.VFSDentry()
}
mntns := vfs.MountNamespaceFromContext(ctx)
@@ -627,14 +620,14 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
if err := virtfs.PrepareRenameDentry(mntns, srcVFSD, dstVFSD); err != nil {
return err
}
- replaced, err := srcDir.inode.Rename(ctx, src.name, pc, srcVFSD, dstDirVFSD)
+ replaced, err := srcDir.inode.Rename(ctx, src.name, pc, src, dstDir)
if err != nil {
virtfs.AbortRenameDentry(srcVFSD, dstVFSD)
return err
}
delete(srcDir.children, src.name)
if srcDir != dstDir {
- fs.deferDecRef(srcDirVFSD)
+ fs.deferDecRef(srcDir)
dstDir.IncRef()
}
src.parent = dstDir
@@ -643,7 +636,11 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
dstDir.children = make(map[string]*Dentry)
}
dstDir.children[pc] = src
- virtfs.CommitRenameReplaceDentry(ctx, srcVFSD, replaced)
+ var replaceVFSD *vfs.Dentry
+ if replaced != nil {
+ replaceVFSD = replaced.VFSDentry()
+ }
+ virtfs.CommitRenameReplaceDentry(ctx, srcVFSD, replaceVFSD)
return nil
}
@@ -682,7 +679,7 @@ func (fs *Filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error
return err
}
- if err := parentDentry.inode.RmDir(ctx, d.name, d.VFSDentry()); err != nil {
+ if err := parentDentry.inode.RmDir(ctx, d.name, d); err != nil {
virtfs.AbortDeleteDentry(vfsd)
return err
}
@@ -736,12 +733,12 @@ func (fs *Filesystem) SymlinkAt(ctx context.Context, rp *vfs.ResolvingPath, targ
}
fs.mu.Lock()
defer fs.mu.Unlock()
- parentVFSD, parentInode, err := fs.walkParentDirLocked(ctx, rp)
+ parent, err := fs.walkParentDirLocked(ctx, rp)
fs.processDeferredDecRefsLocked(ctx)
if err != nil {
return err
}
- pc, err := checkCreateLocked(ctx, rp, parentVFSD, parentInode)
+ pc, err := checkCreateLocked(ctx, rp, parent)
if err != nil {
return err
}
@@ -749,11 +746,11 @@ func (fs *Filesystem) SymlinkAt(ctx context.Context, rp *vfs.ResolvingPath, targ
return err
}
defer rp.Mount().EndWrite()
- childVFSD, err := parentInode.NewSymlink(ctx, pc, target)
+ child, err := parent.inode.NewSymlink(ctx, pc, target)
if err != nil {
return err
}
- parentVFSD.Impl().(*Dentry).InsertChild(pc, childVFSD.Impl().(*Dentry))
+ parent.InsertChild(pc, child)
return nil
}
@@ -787,7 +784,7 @@ func (fs *Filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error
if err := virtfs.PrepareDeleteDentry(mntns, vfsd); err != nil {
return err
}
- if err := parentDentry.inode.Unlink(ctx, d.name, d.VFSDentry()); err != nil {
+ if err := parentDentry.inode.Unlink(ctx, d.name, d); err != nil {
virtfs.AbortDeleteDentry(vfsd)
return err
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-06 13:29:24 +0000