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-rw-r--r--pkg/sentry/fs/BUILD1
-rw-r--r--pkg/sentry/fs/dirent.go4
-rw-r--r--pkg/sentry/fs/file_overlay.go85
-rw-r--r--pkg/sentry/fs/fsutil/file.go2
-rw-r--r--pkg/sentry/fs/gofer/file.go2
-rw-r--r--pkg/sentry/fs/gofer/session.go9
-rw-r--r--pkg/sentry/fs/host/file.go2
-rw-r--r--pkg/sentry/fs/host/inode_test.go4
-rw-r--r--pkg/sentry/fs/inode_overlay.go38
-rw-r--r--pkg/sentry/fs/mock.go6
-rw-r--r--pkg/sentry/fs/mount.go42
-rw-r--r--pkg/sentry/fs/mount_overlay.go11
-rw-r--r--pkg/sentry/fs/overlay.go18
-rw-r--r--pkg/sentry/fs/ramfs/dir.go2
-rw-r--r--pkg/sentry/fs/tty/dir.go2
-rw-r--r--pkg/sentry/fs/tty/fs.go7
-rw-r--r--runsc/boot/fs.go6
17 files changed, 174 insertions, 67 deletions
diff --git a/pkg/sentry/fs/BUILD b/pkg/sentry/fs/BUILD
index e5b9b8bc2..d7259b47b 100644
--- a/pkg/sentry/fs/BUILD
+++ b/pkg/sentry/fs/BUILD
@@ -69,6 +69,7 @@ go_library(
"//pkg/state",
"//pkg/syserror",
"//pkg/waiter",
+ "//third_party/gvsync",
],
)
diff --git a/pkg/sentry/fs/dirent.go b/pkg/sentry/fs/dirent.go
index 3cba259d9..28651e58b 100644
--- a/pkg/sentry/fs/dirent.go
+++ b/pkg/sentry/fs/dirent.go
@@ -918,7 +918,7 @@ type DirIterator interface {
// calls, and must start with the given offset.
//
// The caller must ensure that this operation is permitted.
- IterateDir(ctx context.Context, dirCtx *DirCtx, offset int) (int, error)
+ IterateDir(ctx context.Context, d *Dirent, dirCtx *DirCtx, offset int) (int, error)
}
// DirentReaddir serializes the directory entries of d including "." and "..".
@@ -988,7 +988,7 @@ func direntReaddir(ctx context.Context, d *Dirent, it DirIterator, root *Dirent,
// it.IterateDir should be passed an offset that does not include the
// initial dot elements. We will add them back later.
offset -= 2
- newOffset, err := it.IterateDir(ctx, dirCtx, int(offset))
+ newOffset, err := it.IterateDir(ctx, d, dirCtx, int(offset))
if int64(newOffset) < offset {
panic(fmt.Sprintf("node.Readdir returned offset %v less than input offset %v", newOffset, offset))
}
diff --git a/pkg/sentry/fs/file_overlay.go b/pkg/sentry/fs/file_overlay.go
index 5fb5fbe97..29e5618f4 100644
--- a/pkg/sentry/fs/file_overlay.go
+++ b/pkg/sentry/fs/file_overlay.go
@@ -85,12 +85,6 @@ type overlayFileOperations struct {
// protected by File.mu of the owning file, which is held during
// Readdir and Seek calls.
dirCursor string
-
- // dirCacheMu protects dirCache.
- dirCacheMu sync.RWMutex `state:"nosave"`
-
- // dirCache is cache of DentAttrs from upper and lower Inodes.
- dirCache *SortedDentryMap
}
// Release implements FileOperations.Release.
@@ -171,53 +165,68 @@ func (f *overlayFileOperations) Readdir(ctx context.Context, file *File, seriali
if root != nil {
defer root.DecRef()
}
+
dirCtx := &DirCtx{
Serializer: serializer,
DirCursor: &f.dirCursor,
}
+ return DirentReaddir(ctx, file.Dirent, f, root, dirCtx, file.Offset())
+}
- // If the directory dirent is frozen, then DirentReaddir will calculate
- // the children based off the frozen dirent tree. There is no need to
- // call readdir on the upper/lower layers.
- if file.Dirent.frozen {
- return DirentReaddir(ctx, file.Dirent, f, root, dirCtx, file.Offset())
+// IterateDir implements DirIterator.IterateDir.
+func (f *overlayFileOperations) IterateDir(ctx context.Context, d *Dirent, dirCtx *DirCtx, offset int) (int, error) {
+ o := d.Inode.overlay
+
+ if !d.Inode.MountSource.CacheReaddir() {
+ // Can't use the dirCache. Simply read the entries.
+ entries, err := readdirEntries(ctx, o)
+ if err != nil {
+ return offset, err
+ }
+ n, err := GenericReaddir(dirCtx, entries)
+ return offset + n, err
}
- // Otherwise proceed with usual overlay readdir.
- o := file.Dirent.Inode.overlay
+ // Otherwise, use or create cached entries.
+
+ o.dirCacheMu.RLock()
+ if o.dirCache != nil {
+ n, err := GenericReaddir(dirCtx, o.dirCache)
+ o.dirCacheMu.RUnlock()
+ return offset + n, err
+ }
+ o.dirCacheMu.RUnlock()
// readdirEntries holds o.copyUpMu to ensure that copy-up does not
- // occur while calculating the readir results.
+ // occur while calculating the readdir results.
//
// However, it is possible for a copy-up to occur after the call to
- // readdirEntries, but before setting f.dirCache. This is OK, since
- // copy-up only does not change the children in a way that would affect
- // the children returned in dirCache. Copy-up only moves
- // files/directories between layers in the overlay.
+ // readdirEntries, but before setting o.dirCache. This is OK, since
+ // copy-up does not change the children in a way that would affect the
+ // children returned in dirCache. Copy-up only moves files/directories
+ // between layers in the overlay.
//
- // It is also possible for Readdir to race with a Create operation
- // (which may trigger a copy-up during it's execution). Depending on
- // whether the Create happens before or after the readdirEntries call,
- // the newly created file may or may not appear in the readdir results.
- // But this can only be caused by a real race between readdir and
- // create syscalls, so it's also OK.
- dirCache, err := readdirEntries(ctx, o)
- if err != nil {
- return file.Offset(), err
+ // We must hold dirCacheMu around both readdirEntries and setting
+ // o.dirCache to synchronize with dirCache invalidations done by
+ // Create, Remove, Rename.
+ o.dirCacheMu.Lock()
+
+ // We expect dirCache to be nil (we just checked above), but there is a
+ // chance that a racing call managed to just set it, in which case we
+ // can use that new value.
+ if o.dirCache == nil {
+ dirCache, err := readdirEntries(ctx, o)
+ if err != nil {
+ o.dirCacheMu.Unlock()
+ return offset, err
+ }
+ o.dirCache = dirCache
}
- f.dirCacheMu.Lock()
- f.dirCache = dirCache
- f.dirCacheMu.Unlock()
+ o.dirCacheMu.DowngradeLock()
+ n, err := GenericReaddir(dirCtx, o.dirCache)
+ o.dirCacheMu.RUnlock()
- return DirentReaddir(ctx, file.Dirent, f, root, dirCtx, file.Offset())
-}
-
-// IterateDir implements DirIterator.IterateDir.
-func (f *overlayFileOperations) IterateDir(ctx context.Context, dirCtx *DirCtx, offset int) (int, error) {
- f.dirCacheMu.RLock()
- n, err := GenericReaddir(dirCtx, f.dirCache)
- f.dirCacheMu.RUnlock()
return offset + n, err
}
diff --git a/pkg/sentry/fs/fsutil/file.go b/pkg/sentry/fs/fsutil/file.go
index cca540b6c..d7ddc038b 100644
--- a/pkg/sentry/fs/fsutil/file.go
+++ b/pkg/sentry/fs/fsutil/file.go
@@ -285,7 +285,7 @@ func NewStaticDirFileOperations(dentries *fs.SortedDentryMap) *StaticDirFileOper
}
// IterateDir implements DirIterator.IterateDir.
-func (sdfo *StaticDirFileOperations) IterateDir(ctx context.Context, dirCtx *fs.DirCtx, offset int) (int, error) {
+func (sdfo *StaticDirFileOperations) IterateDir(ctx context.Context, d *fs.Dirent, dirCtx *fs.DirCtx, offset int) (int, error) {
n, err := fs.GenericReaddir(dirCtx, sdfo.dentryMap)
return offset + n, err
}
diff --git a/pkg/sentry/fs/gofer/file.go b/pkg/sentry/fs/gofer/file.go
index ebbca162b..9e2e412cd 100644
--- a/pkg/sentry/fs/gofer/file.go
+++ b/pkg/sentry/fs/gofer/file.go
@@ -137,7 +137,7 @@ func (f *fileOperations) Readdir(ctx context.Context, file *fs.File, serializer
}
// IterateDir implements fs.DirIterator.IterateDir.
-func (f *fileOperations) IterateDir(ctx context.Context, dirCtx *fs.DirCtx, offset int) (int, error) {
+func (f *fileOperations) IterateDir(ctx context.Context, d *fs.Dirent, dirCtx *fs.DirCtx, offset int) (int, error) {
f.inodeOperations.readdirMu.Lock()
defer f.inodeOperations.readdirMu.Unlock()
diff --git a/pkg/sentry/fs/gofer/session.go b/pkg/sentry/fs/gofer/session.go
index 7ad0d8bc5..e9a07175a 100644
--- a/pkg/sentry/fs/gofer/session.go
+++ b/pkg/sentry/fs/gofer/session.go
@@ -145,16 +145,21 @@ func (s *session) Destroy() {
s.client.Close()
}
-// Revalidate implements MountSource.Revalidate.
+// Revalidate implements MountSourceOperations.Revalidate.
func (s *session) Revalidate(ctx context.Context, name string, parent, child *fs.Inode) bool {
return s.cachePolicy.revalidate(ctx, name, parent, child)
}
-// Keep implements MountSource.Keep.
+// Keep implements MountSourceOperations.Keep.
func (s *session) Keep(d *fs.Dirent) bool {
return s.cachePolicy.keep(d)
}
+// CacheReaddir implements MountSourceOperations.CacheReaddir.
+func (s *session) CacheReaddir() bool {
+ return s.cachePolicy.cacheReaddir()
+}
+
// ResetInodeMappings implements fs.MountSourceOperations.ResetInodeMappings.
func (s *session) ResetInodeMappings() {
s.inodeMappings = make(map[uint64]string)
diff --git a/pkg/sentry/fs/host/file.go b/pkg/sentry/fs/host/file.go
index bd665a6b1..f6c626f2c 100644
--- a/pkg/sentry/fs/host/file.go
+++ b/pkg/sentry/fs/host/file.go
@@ -179,7 +179,7 @@ func (f *fileOperations) Readdir(ctx context.Context, file *fs.File, serializer
}
// IterateDir implements fs.DirIterator.IterateDir.
-func (f *fileOperations) IterateDir(ctx context.Context, dirCtx *fs.DirCtx, offset int) (int, error) {
+func (f *fileOperations) IterateDir(ctx context.Context, d *fs.Dirent, dirCtx *fs.DirCtx, offset int) (int, error) {
if f.dirinfo == nil {
f.dirinfo = new(dirInfo)
f.dirinfo.buf = make([]byte, usermem.PageSize)
diff --git a/pkg/sentry/fs/host/inode_test.go b/pkg/sentry/fs/host/inode_test.go
index 18994c456..2d959f10d 100644
--- a/pkg/sentry/fs/host/inode_test.go
+++ b/pkg/sentry/fs/host/inode_test.go
@@ -64,12 +64,12 @@ func TestMultipleReaddir(t *testing.T) {
defer openFile.DecRef()
c1 := &fs.DirCtx{DirCursor: new(string)}
- if _, err := openFile.FileOperations.(*fileOperations).IterateDir(ctx, c1, 0); err != nil {
+ if _, err := openFile.FileOperations.(*fileOperations).IterateDir(ctx, dirent, c1, 0); err != nil {
t.Fatalf("First Readdir failed: %v", err)
}
c2 := &fs.DirCtx{DirCursor: new(string)}
- if _, err := openFile.FileOperations.(*fileOperations).IterateDir(ctx, c2, 0); err != nil {
+ if _, err := openFile.FileOperations.(*fileOperations).IterateDir(ctx, dirent, c2, 0); err != nil {
t.Errorf("Second Readdir failed: %v", err)
}
diff --git a/pkg/sentry/fs/inode_overlay.go b/pkg/sentry/fs/inode_overlay.go
index 920d86042..b247fa514 100644
--- a/pkg/sentry/fs/inode_overlay.go
+++ b/pkg/sentry/fs/inode_overlay.go
@@ -217,6 +217,9 @@ func overlayCreate(ctx context.Context, o *overlayEntry, parent *Dirent, name st
return nil, err
}
+ // We've added to the directory so we must drop the cache.
+ o.markDirectoryDirty()
+
// Take another reference on the upper file's inode, which will be
// owned by the overlay entry.
upperFile.Dirent.Inode.IncRef()
@@ -265,7 +268,12 @@ func overlayCreateDirectory(ctx context.Context, o *overlayEntry, parent *Dirent
if err := copyUpLockedForRename(ctx, parent); err != nil {
return err
}
- return o.upper.InodeOperations.CreateDirectory(ctx, o.upper, name, perm)
+ if err := o.upper.InodeOperations.CreateDirectory(ctx, o.upper, name, perm); err != nil {
+ return err
+ }
+ // We've added to the directory so we must drop the cache.
+ o.markDirectoryDirty()
+ return nil
}
func overlayCreateLink(ctx context.Context, o *overlayEntry, parent *Dirent, oldname string, newname string) error {
@@ -273,7 +281,12 @@ func overlayCreateLink(ctx context.Context, o *overlayEntry, parent *Dirent, old
if err := copyUpLockedForRename(ctx, parent); err != nil {
return err
}
- return o.upper.InodeOperations.CreateLink(ctx, o.upper, oldname, newname)
+ if err := o.upper.InodeOperations.CreateLink(ctx, o.upper, oldname, newname); err != nil {
+ return err
+ }
+ // We've added to the directory so we must drop the cache.
+ o.markDirectoryDirty()
+ return nil
}
func overlayCreateHardLink(ctx context.Context, o *overlayEntry, parent *Dirent, target *Dirent, name string) error {
@@ -285,7 +298,12 @@ func overlayCreateHardLink(ctx context.Context, o *overlayEntry, parent *Dirent,
if err := copyUpLockedForRename(ctx, target); err != nil {
return err
}
- return o.upper.InodeOperations.CreateHardLink(ctx, o.upper, target.Inode.overlay.upper, name)
+ if err := o.upper.InodeOperations.CreateHardLink(ctx, o.upper, target.Inode.overlay.upper, name); err != nil {
+ return err
+ }
+ // We've added to the directory so we must drop the cache.
+ o.markDirectoryDirty()
+ return nil
}
func overlayCreateFifo(ctx context.Context, o *overlayEntry, parent *Dirent, name string, perm FilePermissions) error {
@@ -293,7 +311,12 @@ func overlayCreateFifo(ctx context.Context, o *overlayEntry, parent *Dirent, nam
if err := copyUpLockedForRename(ctx, parent); err != nil {
return err
}
- return o.upper.InodeOperations.CreateFifo(ctx, o.upper, name, perm)
+ if err := o.upper.InodeOperations.CreateFifo(ctx, o.upper, name, perm); err != nil {
+ return err
+ }
+ // We've added to the directory so we must drop the cache.
+ o.markDirectoryDirty()
+ return nil
}
func overlayRemove(ctx context.Context, o *overlayEntry, parent *Dirent, child *Dirent) error {
@@ -318,6 +341,8 @@ func overlayRemove(ctx context.Context, o *overlayEntry, parent *Dirent, child *
if child.Inode.overlay.lowerExists {
return overlayCreateWhiteout(o.upper, child.name)
}
+ // We've removed from the directory so we must drop the cache.
+ o.markDirectoryDirty()
return nil
}
@@ -395,6 +420,8 @@ func overlayRename(ctx context.Context, o *overlayEntry, oldParent *Dirent, rena
if renamed.Inode.overlay.lowerExists {
return overlayCreateWhiteout(oldParent.Inode.overlay.upper, oldName)
}
+ // We've changed the directory so we must drop the cache.
+ o.markDirectoryDirty()
return nil
}
@@ -411,6 +438,9 @@ func overlayBind(ctx context.Context, o *overlayEntry, parent *Dirent, name stri
return nil, err
}
+ // We've added to the directory so we must drop the cache.
+ o.markDirectoryDirty()
+
// Grab the inode and drop the dirent, we don't need it.
inode := d.Inode
inode.IncRef()
diff --git a/pkg/sentry/fs/mock.go b/pkg/sentry/fs/mock.go
index b3c4ad80b..7a24c6f1b 100644
--- a/pkg/sentry/fs/mock.go
+++ b/pkg/sentry/fs/mock.go
@@ -75,6 +75,12 @@ func (n *MockMountSourceOps) Keep(dirent *Dirent) bool {
return n.keep
}
+// CacheReaddir implements fs.MountSourceOperations.CacheReaddir.
+func (n *MockMountSourceOps) CacheReaddir() bool {
+ // Common case: cache readdir results if there is a dirent cache.
+ return n.keep
+}
+
// WriteOut implements fs.InodeOperations.WriteOut.
func (n *MockInodeOperations) WriteOut(context.Context, *Inode) error {
return nil
diff --git a/pkg/sentry/fs/mount.go b/pkg/sentry/fs/mount.go
index 2eb6a9d82..912495528 100644
--- a/pkg/sentry/fs/mount.go
+++ b/pkg/sentry/fs/mount.go
@@ -23,8 +23,8 @@ import (
"gvisor.dev/gvisor/pkg/sentry/context"
)
-// DirentOperations provide file systems greater control over how long a Dirent stays pinned
-// in core. Implementations must not take Dirent.mu.
+// DirentOperations provide file systems greater control over how long a Dirent
+// stays pinned in core. Implementations must not take Dirent.mu.
type DirentOperations interface {
// Revalidate is called during lookup each time we encounter a Dirent
// in the cache. Implementations may update stale properties of the
@@ -37,6 +37,12 @@ type DirentOperations interface {
// Keep returns true if the Dirent should be kept in memory for as long
// as possible beyond any active references.
Keep(dirent *Dirent) bool
+
+ // CacheReaddir returns true if directory entries returned by
+ // FileOperations.Readdir may be cached for future use.
+ //
+ // Postconditions: This method must always return the same value.
+ CacheReaddir() bool
}
// MountSourceOperations contains filesystem specific operations.
@@ -190,25 +196,28 @@ func (msrc *MountSource) SetDirentCacheLimiter(l *DirentCacheLimiter) {
// aggressively.
func NewCachingMountSource(ctx context.Context, filesystem Filesystem, flags MountSourceFlags) *MountSource {
return NewMountSource(ctx, &SimpleMountSourceOperations{
- keep: true,
- revalidate: false,
+ keep: true,
+ revalidate: false,
+ cacheReaddir: true,
}, filesystem, flags)
}
// NewNonCachingMountSource returns a generic mount that will never cache dirents.
func NewNonCachingMountSource(ctx context.Context, filesystem Filesystem, flags MountSourceFlags) *MountSource {
return NewMountSource(ctx, &SimpleMountSourceOperations{
- keep: false,
- revalidate: false,
+ keep: false,
+ revalidate: false,
+ cacheReaddir: false,
}, filesystem, flags)
}
// NewRevalidatingMountSource returns a generic mount that will cache dirents,
-// but will revalidate them on each lookup.
+// but will revalidate them on each lookup and always perform uncached readdir.
func NewRevalidatingMountSource(ctx context.Context, filesystem Filesystem, flags MountSourceFlags) *MountSource {
return NewMountSource(ctx, &SimpleMountSourceOperations{
- keep: true,
- revalidate: true,
+ keep: true,
+ revalidate: true,
+ cacheReaddir: false,
}, filesystem, flags)
}
@@ -216,8 +225,9 @@ func NewRevalidatingMountSource(ctx context.Context, filesystem Filesystem, flag
// an actual filesystem. It is always non-caching.
func NewPseudoMountSource(ctx context.Context) *MountSource {
return NewMountSource(ctx, &SimpleMountSourceOperations{
- keep: false,
- revalidate: false,
+ keep: false,
+ revalidate: false,
+ cacheReaddir: false,
}, nil, MountSourceFlags{})
}
@@ -225,8 +235,9 @@ func NewPseudoMountSource(ctx context.Context) *MountSource {
//
// +stateify savable
type SimpleMountSourceOperations struct {
- keep bool
- revalidate bool
+ keep bool
+ revalidate bool
+ cacheReaddir bool
}
// Revalidate implements MountSourceOperations.Revalidate.
@@ -239,6 +250,11 @@ func (smo *SimpleMountSourceOperations) Keep(*Dirent) bool {
return smo.keep
}
+// CacheReaddir implements MountSourceOperations.CacheReaddir.
+func (smo *SimpleMountSourceOperations) CacheReaddir() bool {
+ return smo.cacheReaddir
+}
+
// ResetInodeMappings implements MountSourceOperations.ResetInodeMappings.
func (*SimpleMountSourceOperations) ResetInodeMappings() {}
diff --git a/pkg/sentry/fs/mount_overlay.go b/pkg/sentry/fs/mount_overlay.go
index bc0ce7adc..4fcdd6c01 100644
--- a/pkg/sentry/fs/mount_overlay.go
+++ b/pkg/sentry/fs/mount_overlay.go
@@ -81,6 +81,17 @@ func (o *overlayMountSourceOperations) Keep(dirent *Dirent) bool {
return o.upper.Keep(dirent)
}
+// CacheReaddir implements MountSourceOperations.CacheReaddir for an overlay by
+// performing the logical AND of the upper and lower filesystems' CacheReaddir
+// methods.
+//
+// N.B. This is fs-global instead of inode-specific because it must always
+// return the same value. If it was inode-specific, we couldn't guarantee that
+// property across copy up.
+func (o *overlayMountSourceOperations) CacheReaddir() bool {
+ return o.lower.CacheReaddir() && o.upper.CacheReaddir()
+}
+
// ResetInodeMappings propagates the call to both upper and lower MountSource.
func (o *overlayMountSourceOperations) ResetInodeMappings() {
o.upper.ResetInodeMappings()
diff --git a/pkg/sentry/fs/overlay.go b/pkg/sentry/fs/overlay.go
index c87f24997..1d3ff39e0 100644
--- a/pkg/sentry/fs/overlay.go
+++ b/pkg/sentry/fs/overlay.go
@@ -24,6 +24,7 @@ import (
"gvisor.dev/gvisor/pkg/sentry/memmap"
"gvisor.dev/gvisor/pkg/sentry/usermem"
"gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/third_party/gvsync"
)
// The virtual filesystem implements an overlay configuration. For a high-level
@@ -196,6 +197,12 @@ type overlayEntry struct {
// these locks is sufficient to read upper; holding all three for writing
// is required to mutate it.
upper *Inode
+
+ // dirCacheMu protects dirCache.
+ dirCacheMu gvsync.DowngradableRWMutex `state:"nosave"`
+
+ // dirCache is cache of DentAttrs from upper and lower Inodes.
+ dirCache *SortedDentryMap
}
// newOverlayEntry returns a new overlayEntry.
@@ -258,6 +265,17 @@ func (o *overlayEntry) isMappableLocked() bool {
return o.inodeLocked().Mappable() != nil
}
+// markDirectoryDirty marks any cached data dirty for this directory. This is
+// necessary in order to ensure that this node does not retain stale state
+// throughout its lifetime across multiple open directory handles.
+//
+// Currently this means invalidating any readdir caches.
+func (o *overlayEntry) markDirectoryDirty() {
+ o.dirCacheMu.Lock()
+ o.dirCache = nil
+ o.dirCacheMu.Unlock()
+}
+
// AddMapping implements memmap.Mappable.AddMapping.
func (o *overlayEntry) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) error {
o.mapsMu.Lock()
diff --git a/pkg/sentry/fs/ramfs/dir.go b/pkg/sentry/fs/ramfs/dir.go
index 0c9e6ec09..f3e984c24 100644
--- a/pkg/sentry/fs/ramfs/dir.go
+++ b/pkg/sentry/fs/ramfs/dir.go
@@ -431,7 +431,7 @@ func (dfo *dirFileOperations) Seek(ctx context.Context, file *fs.File, whence fs
}
// IterateDir implements DirIterator.IterateDir.
-func (dfo *dirFileOperations) IterateDir(ctx context.Context, dirCtx *fs.DirCtx, offset int) (int, error) {
+func (dfo *dirFileOperations) IterateDir(ctx context.Context, d *fs.Dirent, dirCtx *fs.DirCtx, offset int) (int, error) {
dfo.dir.mu.Lock()
defer dfo.dir.mu.Unlock()
diff --git a/pkg/sentry/fs/tty/dir.go b/pkg/sentry/fs/tty/dir.go
index 58a26742c..1d128532b 100644
--- a/pkg/sentry/fs/tty/dir.go
+++ b/pkg/sentry/fs/tty/dir.go
@@ -307,7 +307,7 @@ type dirFileOperations struct {
var _ fs.FileOperations = (*dirFileOperations)(nil)
// IterateDir implements DirIterator.IterateDir.
-func (df *dirFileOperations) IterateDir(ctx context.Context, dirCtx *fs.DirCtx, offset int) (int, error) {
+func (df *dirFileOperations) IterateDir(ctx context.Context, d *fs.Dirent, dirCtx *fs.DirCtx, offset int) (int, error) {
df.di.mu.Lock()
defer df.di.mu.Unlock()
diff --git a/pkg/sentry/fs/tty/fs.go b/pkg/sentry/fs/tty/fs.go
index 1bbfbb90a..edee56c12 100644
--- a/pkg/sentry/fs/tty/fs.go
+++ b/pkg/sentry/fs/tty/fs.go
@@ -94,6 +94,13 @@ func (superOperations) Keep(*fs.Dirent) bool {
return false
}
+// CacheReaddir implements fs.DirentOperations.CacheReaddir.
+//
+// CacheReaddir returns false because entries change on master operations.
+func (superOperations) CacheReaddir() bool {
+ return false
+}
+
// ResetInodeMappings implements MountSourceOperations.ResetInodeMappings.
func (superOperations) ResetInodeMappings() {}
diff --git a/runsc/boot/fs.go b/runsc/boot/fs.go
index 5c2220d83..af52286a6 100644
--- a/runsc/boot/fs.go
+++ b/runsc/boot/fs.go
@@ -239,7 +239,11 @@ func mustFindFilesystem(name string) fs.Filesystem {
// addSubmountOverlay overlays the inode over a ramfs tree containing the given
// paths.
func addSubmountOverlay(ctx context.Context, inode *fs.Inode, submounts []string) (*fs.Inode, error) {
- msrc := fs.NewPseudoMountSource(ctx)
+ // Construct a ramfs tree of mount points. The contents never
+ // change, so this can be fully caching. There's no real
+ // filesystem backing this tree, so we set the filesystem to
+ // nil.
+ msrc := fs.NewCachingMountSource(ctx, nil, fs.MountSourceFlags{})
mountTree, err := ramfs.MakeDirectoryTree(ctx, msrc, submounts)
if err != nil {
return nil, fmt.Errorf("creating mount tree: %v", err)
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-28 23:35:50 +0000