From b2ae7ea1bb207eddadd7962080e7bd0b8634db96 Mon Sep 17 00:00:00 2001 From: Nayana Bidari Date: Mon, 3 Aug 2020 13:33:47 -0700 Subject: Plumbing context.Context to DecRef() and Release(). context is passed to DecRef() and Release() which is needed for SO_LINGER implementation. PiperOrigin-RevId: 324672584 --- pkg/sentry/kernel/fd_table.go | 55 +++++++++++++++++++++++-------------------- 1 file changed, 29 insertions(+), 26 deletions(-) (limited to 'pkg/sentry/kernel/fd_table.go') diff --git a/pkg/sentry/kernel/fd_table.go b/pkg/sentry/kernel/fd_table.go index 4b7d234a4..ce53af69b 100644 --- a/pkg/sentry/kernel/fd_table.go +++ b/pkg/sentry/kernel/fd_table.go @@ -98,7 +98,7 @@ type FDTable struct { func (f *FDTable) saveDescriptorTable() map[int32]descriptor { m := make(map[int32]descriptor) - f.forEach(func(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) { + f.forEach(context.Background(), func(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) { m[fd] = descriptor{ file: file, fileVFS2: fileVFS2, @@ -109,6 +109,7 @@ func (f *FDTable) saveDescriptorTable() map[int32]descriptor { } func (f *FDTable) loadDescriptorTable(m map[int32]descriptor) { + ctx := context.Background() f.init() // Initialize table. for fd, d := range m { f.setAll(fd, d.file, d.fileVFS2, d.flags) @@ -118,9 +119,9 @@ func (f *FDTable) loadDescriptorTable(m map[int32]descriptor) { // reference taken by set above. switch { case d.file != nil: - d.file.DecRef() + d.file.DecRef(ctx) case d.fileVFS2 != nil: - d.fileVFS2.DecRef() + d.fileVFS2.DecRef(ctx) } } } @@ -144,14 +145,15 @@ func (f *FDTable) drop(file *fs.File) { d.InotifyEvent(ev, 0) // Drop the table reference. - file.DecRef() + file.DecRef(context.Background()) } // dropVFS2 drops the table reference. func (f *FDTable) dropVFS2(file *vfs.FileDescription) { // Release any POSIX lock possibly held by the FDTable. Range {0, 0} means the // entire file. - err := file.UnlockPOSIX(context.Background(), f, 0, 0, linux.SEEK_SET) + ctx := context.Background() + err := file.UnlockPOSIX(ctx, f, 0, 0, linux.SEEK_SET) if err != nil && err != syserror.ENOLCK { panic(fmt.Sprintf("UnlockPOSIX failed: %v", err)) } @@ -161,10 +163,10 @@ func (f *FDTable) dropVFS2(file *vfs.FileDescription) { if file.IsWritable() { ev = linux.IN_CLOSE_WRITE } - file.Dentry().InotifyWithParent(ev, 0, vfs.PathEvent) + file.Dentry().InotifyWithParent(ctx, ev, 0, vfs.PathEvent) // Drop the table's reference. - file.DecRef() + file.DecRef(ctx) } // NewFDTable allocates a new FDTable that may be used by tasks in k. @@ -175,15 +177,15 @@ func (k *Kernel) NewFDTable() *FDTable { } // destroy removes all of the file descriptors from the map. -func (f *FDTable) destroy() { - f.RemoveIf(func(*fs.File, *vfs.FileDescription, FDFlags) bool { +func (f *FDTable) destroy(ctx context.Context) { + f.RemoveIf(ctx, func(*fs.File, *vfs.FileDescription, FDFlags) bool { return true }) } // DecRef implements RefCounter.DecRef with destructor f.destroy. -func (f *FDTable) DecRef() { - f.DecRefWithDestructor(f.destroy) +func (f *FDTable) DecRef(ctx context.Context) { + f.DecRefWithDestructor(ctx, f.destroy) } // Size returns the number of file descriptor slots currently allocated. @@ -195,7 +197,7 @@ func (f *FDTable) Size() int { // forEach iterates over all non-nil files in sorted order. // // It is the caller's responsibility to acquire an appropriate lock. -func (f *FDTable) forEach(fn func(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags)) { +func (f *FDTable) forEach(ctx context.Context, fn func(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags)) { // retries tracks the number of failed TryIncRef attempts for the same FD. retries := 0 fd := int32(0) @@ -214,7 +216,7 @@ func (f *FDTable) forEach(fn func(fd int32, file *fs.File, fileVFS2 *vfs.FileDes continue // Race caught. } fn(fd, file, nil, flags) - file.DecRef() + file.DecRef(ctx) case fileVFS2 != nil: if !fileVFS2.TryIncRef() { retries++ @@ -224,7 +226,7 @@ func (f *FDTable) forEach(fn func(fd int32, file *fs.File, fileVFS2 *vfs.FileDes continue // Race caught. } fn(fd, nil, fileVFS2, flags) - fileVFS2.DecRef() + fileVFS2.DecRef(ctx) } retries = 0 fd++ @@ -234,7 +236,8 @@ func (f *FDTable) forEach(fn func(fd int32, file *fs.File, fileVFS2 *vfs.FileDes // String is a stringer for FDTable. func (f *FDTable) String() string { var buf strings.Builder - f.forEach(func(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) { + ctx := context.Background() + f.forEach(ctx, func(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) { switch { case file != nil: n, _ := file.Dirent.FullName(nil /* root */) @@ -242,7 +245,7 @@ func (f *FDTable) String() string { case fileVFS2 != nil: vfsObj := fileVFS2.Mount().Filesystem().VirtualFilesystem() - name, err := vfsObj.PathnameWithDeleted(context.Background(), vfs.VirtualDentry{}, fileVFS2.VirtualDentry()) + name, err := vfsObj.PathnameWithDeleted(ctx, vfs.VirtualDentry{}, fileVFS2.VirtualDentry()) if err != nil { fmt.Fprintf(&buf, "\n", err) return @@ -541,9 +544,9 @@ func (f *FDTable) GetVFS2(fd int32) (*vfs.FileDescription, FDFlags) { // // Precondition: The caller must be running on the task goroutine, or Task.mu // must be locked. -func (f *FDTable) GetFDs() []int32 { +func (f *FDTable) GetFDs(ctx context.Context) []int32 { fds := make([]int32, 0, int(atomic.LoadInt32(&f.used))) - f.forEach(func(fd int32, _ *fs.File, _ *vfs.FileDescription, _ FDFlags) { + f.forEach(ctx, func(fd int32, _ *fs.File, _ *vfs.FileDescription, _ FDFlags) { fds = append(fds, fd) }) return fds @@ -552,9 +555,9 @@ func (f *FDTable) GetFDs() []int32 { // GetRefs returns a stable slice of references to all files and bumps the // reference count on each. The caller must use DecRef on each reference when // they're done using the slice. -func (f *FDTable) GetRefs() []*fs.File { +func (f *FDTable) GetRefs(ctx context.Context) []*fs.File { files := make([]*fs.File, 0, f.Size()) - f.forEach(func(_ int32, file *fs.File, _ *vfs.FileDescription, _ FDFlags) { + f.forEach(ctx, func(_ int32, file *fs.File, _ *vfs.FileDescription, _ FDFlags) { file.IncRef() // Acquire a reference for caller. files = append(files, file) }) @@ -564,9 +567,9 @@ func (f *FDTable) GetRefs() []*fs.File { // GetRefsVFS2 returns a stable slice of references to all files and bumps the // reference count on each. The caller must use DecRef on each reference when // they're done using the slice. -func (f *FDTable) GetRefsVFS2() []*vfs.FileDescription { +func (f *FDTable) GetRefsVFS2(ctx context.Context) []*vfs.FileDescription { files := make([]*vfs.FileDescription, 0, f.Size()) - f.forEach(func(_ int32, _ *fs.File, file *vfs.FileDescription, _ FDFlags) { + f.forEach(ctx, func(_ int32, _ *fs.File, file *vfs.FileDescription, _ FDFlags) { file.IncRef() // Acquire a reference for caller. files = append(files, file) }) @@ -574,10 +577,10 @@ func (f *FDTable) GetRefsVFS2() []*vfs.FileDescription { } // Fork returns an independent FDTable. -func (f *FDTable) Fork() *FDTable { +func (f *FDTable) Fork(ctx context.Context) *FDTable { clone := f.k.NewFDTable() - f.forEach(func(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) { + f.forEach(ctx, func(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) { // The set function here will acquire an appropriate table // reference for the clone. We don't need anything else. switch { @@ -622,11 +625,11 @@ func (f *FDTable) Remove(fd int32) (*fs.File, *vfs.FileDescription) { } // RemoveIf removes all FDs where cond is true. -func (f *FDTable) RemoveIf(cond func(*fs.File, *vfs.FileDescription, FDFlags) bool) { +func (f *FDTable) RemoveIf(ctx context.Context, cond func(*fs.File, *vfs.FileDescription, FDFlags) bool) { f.mu.Lock() defer f.mu.Unlock() - f.forEach(func(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) { + f.forEach(ctx, func(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) { if cond(file, fileVFS2, flags) { f.set(fd, nil, FDFlags{}) // Clear from table. // Update current available position. -- cgit v1.2.3