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-rw-r--r--pkg/sentry/fsimpl/gofer/directory.go4
-rw-r--r--pkg/sentry/fsimpl/gofer/gofer.go90
-rw-r--r--pkg/sentry/fsimpl/gofer/gofer_state_autogen.go3
-rw-r--r--pkg/sentry/fsimpl/gofer/save_restore.go8
-rw-r--r--pkg/sentry/fsimpl/overlay/overlay.go13
-rw-r--r--pkg/sentry/fsimpl/overlay/overlay_state_autogen.go3
-rw-r--r--pkg/sentry/fsimpl/overlay/save_restore.go27
-rw-r--r--pkg/sentry/vfs/mount.go48
-rw-r--r--pkg/sentry/vfs/save_restore.go7
-rw-r--r--pkg/sentry/vfs/vfs_state_autogen.go3
10 files changed, 176 insertions, 30 deletions
diff --git a/pkg/sentry/fsimpl/gofer/directory.go b/pkg/sentry/fsimpl/gofer/directory.go
index c3af30f49..e993c8e36 100644
--- a/pkg/sentry/fsimpl/gofer/directory.go
+++ b/pkg/sentry/fsimpl/gofer/directory.go
@@ -21,6 +21,7 @@ import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/p9"
+ "gvisor.dev/gvisor/pkg/refsvfs2"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/kernel/pipe"
"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
@@ -100,6 +101,9 @@ func (d *dentry) createSyntheticChildLocked(opts *createSyntheticOpts) {
hostFD: -1,
nlink: uint32(2),
}
+ if refsvfs2.LeakCheckEnabled() {
+ refsvfs2.Register(child, "gofer.dentry")
+ }
switch opts.mode.FileType() {
case linux.S_IFDIR:
// Nothing else needs to be done.
diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go
index f7c94cce1..604c6d7cd 100644
--- a/pkg/sentry/fsimpl/gofer/gofer.go
+++ b/pkg/sentry/fsimpl/gofer/gofer.go
@@ -46,6 +46,8 @@ import (
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/log"
"gvisor.dev/gvisor/pkg/p9"
+ refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+ "gvisor.dev/gvisor/pkg/refsvfs2"
"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
@@ -109,8 +111,8 @@ type filesystem struct {
// cachedDentries contains all dentries with 0 references. (Due to race
// conditions, it may also contain dentries with non-zero references.)
- // cachedDentriesLen is the number of dentries in cachedDentries. These
- // fields are protected by renameMu.
+ // cachedDentriesLen is the number of dentries in cachedDentries. These fields
+ // are protected by renameMu.
cachedDentries dentryList
cachedDentriesLen uint64
@@ -134,6 +136,10 @@ type filesystem struct {
// savedDentryRW records open read/write handles during save/restore.
savedDentryRW map[*dentry]savedDentryRW
+
+ // released is nonzero once filesystem.Release has been called. It is accessed
+ // with atomic memory operations.
+ released int32
}
// +stateify savable
@@ -454,9 +460,8 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt
return nil, nil, err
}
// Set the root's reference count to 2. One reference is returned to the
- // caller, and the other is deliberately leaked to prevent the root from
- // being "cached" and subsequently evicted. Its resources will still be
- // cleaned up by fs.Release().
+ // caller, and the other is held by fs to prevent the root from being "cached"
+ // and subsequently evicted.
root.refs = 2
fs.root = root
@@ -526,15 +531,16 @@ func (fs *filesystem) dial(ctx context.Context) error {
// Release implements vfs.FilesystemImpl.Release.
func (fs *filesystem) Release(ctx context.Context) {
- mf := fs.mfp.MemoryFile()
+ atomic.StoreInt32(&fs.released, 1)
+ mf := fs.mfp.MemoryFile()
fs.syncMu.Lock()
for d := range fs.syncableDentries {
d.handleMu.Lock()
d.dataMu.Lock()
if h := d.writeHandleLocked(); h.isOpen() {
// Write dirty cached data to the remote file.
- if err := fsutil.SyncDirtyAll(ctx, &d.cache, &d.dirty, d.size, fs.mfp.MemoryFile(), h.writeFromBlocksAt); err != nil {
+ if err := fsutil.SyncDirtyAll(ctx, &d.cache, &d.dirty, d.size, mf, h.writeFromBlocksAt); err != nil {
log.Warningf("gofer.filesystem.Release: failed to flush dentry: %v", err)
}
// TODO(jamieliu): Do we need to flushf/fsync d?
@@ -555,6 +561,21 @@ func (fs *filesystem) Release(ctx context.Context) {
// fs.
fs.syncMu.Unlock()
+ // If leak checking is enabled, release all outstanding references in the
+ // filesystem. We deliberately avoid doing this outside of leak checking; we
+ // have released all external resources above rather than relying on dentry
+ // destructors.
+ if refs_vfs1.GetLeakMode() != refs_vfs1.NoLeakChecking {
+ fs.renameMu.Lock()
+ fs.root.releaseSyntheticRecursiveLocked(ctx)
+ fs.evictAllCachedDentriesLocked(ctx)
+ fs.renameMu.Unlock()
+
+ // An extra reference was held by the filesystem on the root to prevent it from
+ // being cached/evicted.
+ fs.root.DecRef(ctx)
+ }
+
if !fs.iopts.LeakConnection {
// Close the connection to the server. This implicitly clunks all fids.
fs.client.Close()
@@ -563,6 +584,31 @@ func (fs *filesystem) Release(ctx context.Context) {
fs.vfsfs.VirtualFilesystem().PutAnonBlockDevMinor(fs.devMinor)
}
+// releaseSyntheticRecursiveLocked traverses the tree with root d and decrements
+// the reference count on every synthetic dentry. Synthetic dentries have one
+// reference for existence that should be dropped during filesystem.Release.
+//
+// Precondition: d.fs.renameMu is locked.
+func (d *dentry) releaseSyntheticRecursiveLocked(ctx context.Context) {
+ if d.isSynthetic() {
+ d.decRefLocked()
+ d.checkCachingLocked(ctx)
+ }
+ if d.isDir() {
+ var children []*dentry
+ d.dirMu.Lock()
+ for _, child := range d.children {
+ children = append(children, child)
+ }
+ d.dirMu.Unlock()
+ for _, child := range children {
+ if child != nil {
+ child.releaseSyntheticRecursiveLocked(ctx)
+ }
+ }
+ }
+}
+
// dentry implements vfs.DentryImpl.
//
// +stateify savable
@@ -815,6 +861,9 @@ func (fs *filesystem) newDentry(ctx context.Context, file p9file, qid p9.QID, ma
d.nlink = uint32(attr.NLink)
}
d.vfsd.Init(d)
+ if refsvfs2.LeakCheckEnabled() {
+ refsvfs2.Register(d, "gofer.dentry")
+ }
fs.syncMu.Lock()
fs.syncableDentries[d] = struct{}{}
@@ -1210,6 +1259,11 @@ func (d *dentry) decRefLocked() {
}
}
+// LeakMessage implements refsvfs2.CheckedObject.LeakMessage.
+func (d *dentry) LeakMessage() string {
+ return fmt.Sprintf("[gofer.dentry %p] reference count of %d instead of -1", d, atomic.LoadInt64(&d.refs))
+}
+
// InotifyWithParent implements vfs.DentryImpl.InotifyWithParent.
func (d *dentry) InotifyWithParent(ctx context.Context, events, cookie uint32, et vfs.EventType) {
if d.isDir() {
@@ -1292,6 +1346,16 @@ func (d *dentry) checkCachingLocked(ctx context.Context) {
if d.watches.Size() > 0 {
return
}
+
+ if atomic.LoadInt32(&d.fs.released) != 0 {
+ if d.parent != nil {
+ d.parent.dirMu.Lock()
+ delete(d.parent.children, d.name)
+ d.parent.dirMu.Unlock()
+ }
+ d.destroyLocked(ctx)
+ }
+
// If d is already cached, just move it to the front of the LRU.
if d.cached {
d.fs.cachedDentries.Remove(d)
@@ -1310,6 +1374,14 @@ func (d *dentry) checkCachingLocked(ctx context.Context) {
}
}
+// Precondition: fs.renameMu must be locked for writing; it may be temporarily
+// unlocked.
+func (fs *filesystem) evictAllCachedDentriesLocked(ctx context.Context) {
+ for fs.cachedDentriesLen != 0 {
+ fs.evictCachedDentryLocked(ctx)
+ }
+}
+
// Preconditions:
// * fs.renameMu must be locked for writing; it may be temporarily unlocked.
// * fs.cachedDentriesLen != 0.
@@ -1422,6 +1494,10 @@ func (d *dentry) destroyLocked(ctx context.Context) {
panic("gofer.dentry.DecRef() called without holding a reference")
}
}
+
+ if refsvfs2.LeakCheckEnabled() {
+ refsvfs2.Unregister(d, "gofer.dentry")
+ }
}
func (d *dentry) isDeleted() bool {
diff --git a/pkg/sentry/fsimpl/gofer/gofer_state_autogen.go b/pkg/sentry/fsimpl/gofer/gofer_state_autogen.go
index 289c3d6d4..26d0ab4db 100644
--- a/pkg/sentry/fsimpl/gofer/gofer_state_autogen.go
+++ b/pkg/sentry/fsimpl/gofer/gofer_state_autogen.go
@@ -128,6 +128,7 @@ func (fs *filesystem) StateFields() []string {
"specialFileFDs",
"lastIno",
"savedDentryRW",
+ "released",
}
}
@@ -148,6 +149,7 @@ func (fs *filesystem) StateSave(stateSinkObject state.Sink) {
stateSinkObject.Save(10, &fs.specialFileFDs)
stateSinkObject.Save(11, &fs.lastIno)
stateSinkObject.Save(12, &fs.savedDentryRW)
+ stateSinkObject.Save(13, &fs.released)
}
func (fs *filesystem) afterLoad() {}
@@ -166,6 +168,7 @@ func (fs *filesystem) StateLoad(stateSourceObject state.Source) {
stateSourceObject.Load(10, &fs.specialFileFDs)
stateSourceObject.Load(11, &fs.lastIno)
stateSourceObject.Load(12, &fs.savedDentryRW)
+ stateSourceObject.Load(13, &fs.released)
}
func (f *filesystemOptions) StateTypeName() string {
diff --git a/pkg/sentry/fsimpl/gofer/save_restore.go b/pkg/sentry/fsimpl/gofer/save_restore.go
index e995619a6..2ea224c43 100644
--- a/pkg/sentry/fsimpl/gofer/save_restore.go
+++ b/pkg/sentry/fsimpl/gofer/save_restore.go
@@ -23,6 +23,7 @@ import (
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/fdnotifier"
"gvisor.dev/gvisor/pkg/p9"
+ "gvisor.dev/gvisor/pkg/refsvfs2"
"gvisor.dev/gvisor/pkg/safemem"
"gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/syserror"
@@ -53,9 +54,7 @@ func (fs *filesystem) PrepareSave(ctx context.Context) error {
// Purge cached dentries, which may not be reopenable after restore due to
// permission changes.
fs.renameMu.Lock()
- for fs.cachedDentriesLen != 0 {
- fs.evictCachedDentryLocked(ctx)
- }
+ fs.evictAllCachedDentriesLocked(ctx)
fs.renameMu.Unlock()
// Buffer pipe data so that it's available for reading after restore. (This
@@ -141,6 +140,9 @@ func (d *dentry) beforeSave() {
// afterLoad is invoked by stateify.
func (d *dentry) afterLoad() {
d.hostFD = -1
+ if refsvfs2.LeakCheckEnabled() && atomic.LoadInt64(&d.refs) != -1 {
+ refsvfs2.Register(d, "gofer.dentry")
+ }
}
// afterLoad is invoked by stateify.
diff --git a/pkg/sentry/fsimpl/overlay/overlay.go b/pkg/sentry/fsimpl/overlay/overlay.go
index f28411b5b..6fe97c57b 100644
--- a/pkg/sentry/fsimpl/overlay/overlay.go
+++ b/pkg/sentry/fsimpl/overlay/overlay.go
@@ -33,12 +33,14 @@
package overlay
import (
+ "fmt"
"strings"
"sync/atomic"
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/fspath"
+ "gvisor.dev/gvisor/pkg/refsvfs2"
fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/memmap"
@@ -484,6 +486,9 @@ func (fs *filesystem) newDentry() *dentry {
}
d.lowerVDs = d.inlineLowerVDs[:0]
d.vfsd.Init(d)
+ if refsvfs2.LeakCheckEnabled() {
+ refsvfs2.Register(d, "overlay.dentry")
+ }
return d
}
@@ -583,6 +588,14 @@ func (d *dentry) destroyLocked(ctx context.Context) {
panic("overlay.dentry.DecRef() called without holding a reference")
}
}
+ if refsvfs2.LeakCheckEnabled() {
+ refsvfs2.Unregister(d, "overlay.dentry")
+ }
+}
+
+// LeakMessage implements refsvfs2.CheckedObject.LeakMessage.
+func (d *dentry) LeakMessage() string {
+ return fmt.Sprintf("[overlay.dentry %p] reference count of %d instead of -1", d, atomic.LoadInt64(&d.refs))
}
// InotifyWithParent implements vfs.DentryImpl.InotifyWithParent.
diff --git a/pkg/sentry/fsimpl/overlay/overlay_state_autogen.go b/pkg/sentry/fsimpl/overlay/overlay_state_autogen.go
index bdab5d0be..760300f42 100644
--- a/pkg/sentry/fsimpl/overlay/overlay_state_autogen.go
+++ b/pkg/sentry/fsimpl/overlay/overlay_state_autogen.go
@@ -183,8 +183,6 @@ func (d *dentry) StateSave(stateSinkObject state.Sink) {
stateSinkObject.Save(21, &d.watches)
}
-func (d *dentry) afterLoad() {}
-
func (d *dentry) StateLoad(stateSourceObject state.Source) {
stateSourceObject.Load(0, &d.vfsd)
stateSourceObject.Load(1, &d.refs)
@@ -208,6 +206,7 @@ func (d *dentry) StateLoad(stateSourceObject state.Source) {
stateSourceObject.Load(19, &d.isMappable)
stateSourceObject.Load(20, &d.locks)
stateSourceObject.Load(21, &d.watches)
+ stateSourceObject.AfterLoad(d.afterLoad)
}
func (fd *fileDescription) StateTypeName() string {
diff --git a/pkg/sentry/fsimpl/overlay/save_restore.go b/pkg/sentry/fsimpl/overlay/save_restore.go
new file mode 100644
index 000000000..054e17b17
--- /dev/null
+++ b/pkg/sentry/fsimpl/overlay/save_restore.go
@@ -0,0 +1,27 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package overlay
+
+import (
+ "sync/atomic"
+
+ "gvisor.dev/gvisor/pkg/refsvfs2"
+)
+
+func (d *dentry) afterLoad() {
+ if refsvfs2.LeakCheckEnabled() && atomic.LoadInt64(&d.refs) != -1 {
+ refsvfs2.Register(d, "overlay.dentry")
+ }
+}
diff --git a/pkg/sentry/vfs/mount.go b/pkg/sentry/vfs/mount.go
index 78f115bfa..d452d2cda 100644
--- a/pkg/sentry/vfs/mount.go
+++ b/pkg/sentry/vfs/mount.go
@@ -24,6 +24,7 @@ import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/refsvfs2"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/syserror"
)
@@ -106,6 +107,9 @@ func newMount(vfs *VirtualFilesystem, fs *Filesystem, root *Dentry, mntns *Mount
if opts.ReadOnly {
mnt.setReadOnlyLocked(true)
}
+ if refsvfs2.LeakCheckEnabled() {
+ refsvfs2.Register(mnt, "vfs.Mount")
+ }
return mnt
}
@@ -489,26 +493,38 @@ func (mnt *Mount) IncRef() {
// DecRef decrements mnt's reference count.
func (mnt *Mount) DecRef(ctx context.Context) {
- refs := atomic.AddInt64(&mnt.refs, -1)
- if refs&^math.MinInt64 == 0 { // mask out MSB
- var vd VirtualDentry
- if mnt.parent() != nil {
- mnt.vfs.mountMu.Lock()
- mnt.vfs.mounts.seq.BeginWrite()
- vd = mnt.vfs.disconnectLocked(mnt)
- mnt.vfs.mounts.seq.EndWrite()
- mnt.vfs.mountMu.Unlock()
- }
- if mnt.root != nil {
- mnt.root.DecRef(ctx)
- }
- mnt.fs.DecRef(ctx)
- if vd.Ok() {
- vd.DecRef(ctx)
+ r := atomic.AddInt64(&mnt.refs, -1)
+ if r&^math.MinInt64 == 0 { // mask out MSB
+ if refsvfs2.LeakCheckEnabled() {
+ refsvfs2.Unregister(mnt, "vfs.Mount")
}
+ mnt.destroy(ctx)
}
}
+func (mnt *Mount) destroy(ctx context.Context) {
+ var vd VirtualDentry
+ if mnt.parent() != nil {
+ mnt.vfs.mountMu.Lock()
+ mnt.vfs.mounts.seq.BeginWrite()
+ vd = mnt.vfs.disconnectLocked(mnt)
+ mnt.vfs.mounts.seq.EndWrite()
+ mnt.vfs.mountMu.Unlock()
+ }
+ if mnt.root != nil {
+ mnt.root.DecRef(ctx)
+ }
+ mnt.fs.DecRef(ctx)
+ if vd.Ok() {
+ vd.DecRef(ctx)
+ }
+}
+
+// LeakMessage implements refsvfs2.CheckedObject.LeakMessage.
+func (mnt *Mount) LeakMessage() string {
+ return fmt.Sprintf("[vfs.Mount %p] reference count of %d instead of 0", mnt, atomic.LoadInt64(&mnt.refs))
+}
+
// DecRef decrements mntns' reference count.
func (mntns *MountNamespace) DecRef(ctx context.Context) {
vfs := mntns.root.fs.VirtualFilesystem()
diff --git a/pkg/sentry/vfs/save_restore.go b/pkg/sentry/vfs/save_restore.go
index 7aa073510..46e50d55d 100644
--- a/pkg/sentry/vfs/save_restore.go
+++ b/pkg/sentry/vfs/save_restore.go
@@ -19,6 +19,7 @@ import (
"sync/atomic"
"gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/refsvfs2"
)
// FilesystemImplSaveRestoreExtension is an optional extension to
@@ -109,6 +110,12 @@ func (vfs *VirtualFilesystem) loadMounts(mounts []*Mount) {
}
}
+func (mnt *Mount) afterLoad() {
+ if refsvfs2.LeakCheckEnabled() && atomic.LoadInt64(&mnt.refs) != 0 {
+ refsvfs2.Register(mnt, "vfs.Mount")
+ }
+}
+
// afterLoad is called by stateify.
func (epi *epollInterest) afterLoad() {
// Mark all epollInterests as ready after restore so that the next call to
diff --git a/pkg/sentry/vfs/vfs_state_autogen.go b/pkg/sentry/vfs/vfs_state_autogen.go
index 82c9ddec3..67b161d93 100644
--- a/pkg/sentry/vfs/vfs_state_autogen.go
+++ b/pkg/sentry/vfs/vfs_state_autogen.go
@@ -1075,8 +1075,6 @@ func (mnt *Mount) StateSave(stateSinkObject state.Sink) {
stateSinkObject.Save(10, &mnt.writers)
}
-func (mnt *Mount) afterLoad() {}
-
func (mnt *Mount) StateLoad(stateSourceObject state.Source) {
stateSourceObject.Load(0, &mnt.vfs)
stateSourceObject.Load(1, &mnt.fs)
@@ -1089,6 +1087,7 @@ func (mnt *Mount) StateLoad(stateSourceObject state.Source) {
stateSourceObject.Load(9, &mnt.umounted)
stateSourceObject.Load(10, &mnt.writers)
stateSourceObject.LoadValue(5, new(VirtualDentry), func(y interface{}) { mnt.loadKey(y.(VirtualDentry)) })
+ stateSourceObject.AfterLoad(mnt.afterLoad)
}
func (mntns *MountNamespace) StateTypeName() string {
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-06 03:24:27 +0000