summaryrefslogtreecommitdiffhomepage
path: root/pkg/sentry/fsimpl
diff options
context:
space:
mode:
Diffstat (limited to 'pkg/sentry/fsimpl')
-rw-r--r--pkg/sentry/fsimpl/gofer/directory.go4
-rw-r--r--pkg/sentry/fsimpl/gofer/filesystem.go8
-rw-r--r--pkg/sentry/fsimpl/gofer/gofer.go58
-rw-r--r--pkg/sentry/fsimpl/gofer/save_restore.go4
-rw-r--r--pkg/sentry/fsimpl/overlay/BUILD1
-rw-r--r--pkg/sentry/fsimpl/overlay/overlay.go53
-rw-r--r--pkg/sentry/fsimpl/overlay/save_restore.go4
-rw-r--r--pkg/sentry/fsimpl/verity/save_restore.go4
-rw-r--r--pkg/sentry/fsimpl/verity/verity.go112
9 files changed, 149 insertions, 99 deletions
diff --git a/pkg/sentry/fsimpl/gofer/directory.go b/pkg/sentry/fsimpl/gofer/directory.go
index e993c8e36..ce1b2a390 100644
--- a/pkg/sentry/fsimpl/gofer/directory.go
+++ b/pkg/sentry/fsimpl/gofer/directory.go
@@ -101,9 +101,7 @@ func (d *dentry) createSyntheticChildLocked(opts *createSyntheticOpts) {
hostFD: -1,
nlink: uint32(2),
}
- if refsvfs2.LeakCheckEnabled() {
- refsvfs2.Register(child, "gofer.dentry")
- }
+ refsvfs2.Register(child)
switch opts.mode.FileType() {
case linux.S_IFDIR:
// Nothing else needs to be done.
diff --git a/pkg/sentry/fsimpl/gofer/filesystem.go b/pkg/sentry/fsimpl/gofer/filesystem.go
index baecb88c4..57a2ca43c 100644
--- a/pkg/sentry/fsimpl/gofer/filesystem.go
+++ b/pkg/sentry/fsimpl/gofer/filesystem.go
@@ -262,7 +262,7 @@ func (fs *filesystem) revalidateChildLocked(ctx context.Context, vfsObj *vfs.Vir
// treat their invalidation as deletion.
child.setDeleted()
parent.syntheticChildren--
- child.decRefLocked()
+ child.decRefNoCaching()
parent.dirents = nil
}
*ds = appendDentry(*ds, child)
@@ -631,7 +631,7 @@ func (fs *filesystem) unlinkAt(ctx context.Context, rp *vfs.ResolvingPath, dir b
child.setDeleted()
if child.isSynthetic() {
parent.syntheticChildren--
- child.decRefLocked()
+ child.decRefNoCaching()
}
ds = appendDentry(ds, child)
}
@@ -1361,7 +1361,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
replaced.setDeleted()
if replaced.isSynthetic() {
newParent.syntheticChildren--
- replaced.decRefLocked()
+ replaced.decRefNoCaching()
}
ds = appendDentry(ds, replaced)
}
@@ -1370,7 +1370,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
// with reference counts and queue oldParent for checkCachingLocked if the
// parent isn't actually changing.
if oldParent != newParent {
- oldParent.decRefLocked()
+ oldParent.decRefNoCaching()
ds = appendDentry(ds, oldParent)
newParent.IncRef()
if renamed.isSynthetic() {
diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go
index 80668ebc1..6f82ce61b 100644
--- a/pkg/sentry/fsimpl/gofer/gofer.go
+++ b/pkg/sentry/fsimpl/gofer/gofer.go
@@ -590,7 +590,7 @@ func (fs *filesystem) Release(ctx context.Context) {
// Precondition: d.fs.renameMu is locked.
func (d *dentry) releaseSyntheticRecursiveLocked(ctx context.Context) {
if d.isSynthetic() {
- d.decRefLocked()
+ d.decRefNoCaching()
d.checkCachingLocked(ctx)
}
if d.isDir() {
@@ -860,10 +860,7 @@ 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")
- }
-
+ refsvfs2.Register(d)
fs.syncMu.Lock()
fs.syncableDentries[d] = struct{}{}
fs.syncMu.Unlock()
@@ -1222,17 +1219,19 @@ func dentryGIDFromP9GID(gid p9.GID) uint32 {
func (d *dentry) IncRef() {
// d.refs may be 0 if d.fs.renameMu is locked, which serializes against
// d.checkCachingLocked().
- atomic.AddInt64(&d.refs, 1)
+ r := atomic.AddInt64(&d.refs, 1)
+ refsvfs2.LogIncRef(d, r)
}
// TryIncRef implements vfs.DentryImpl.TryIncRef.
func (d *dentry) TryIncRef() bool {
for {
- refs := atomic.LoadInt64(&d.refs)
- if refs <= 0 {
+ r := atomic.LoadInt64(&d.refs)
+ if r <= 0 {
return false
}
- if atomic.CompareAndSwapInt64(&d.refs, refs, refs+1) {
+ if atomic.CompareAndSwapInt64(&d.refs, r, r+1) {
+ refsvfs2.LogTryIncRef(d, r+1)
return true
}
}
@@ -1240,22 +1239,28 @@ func (d *dentry) TryIncRef() bool {
// DecRef implements vfs.DentryImpl.DecRef.
func (d *dentry) DecRef(ctx context.Context) {
- if refs := atomic.AddInt64(&d.refs, -1); refs == 0 {
+ if d.decRefNoCaching() == 0 {
d.fs.renameMu.Lock()
d.checkCachingLocked(ctx)
d.fs.renameMu.Unlock()
- } else if refs < 0 {
- panic("gofer.dentry.DecRef() called without holding a reference")
}
}
-// decRefLocked decrements d's reference count without calling
+// decRefNoCaching decrements d's reference count without calling
// d.checkCachingLocked, even if d's reference count reaches 0; callers are
// responsible for ensuring that d.checkCachingLocked will be called later.
-func (d *dentry) decRefLocked() {
- if refs := atomic.AddInt64(&d.refs, -1); refs < 0 {
- panic("gofer.dentry.decRefLocked() called without holding a reference")
+func (d *dentry) decRefNoCaching() int64 {
+ r := atomic.AddInt64(&d.refs, -1)
+ refsvfs2.LogDecRef(d, r)
+ if r < 0 {
+ panic("gofer.dentry.decRefNoCaching() called without holding a reference")
}
+ return r
+}
+
+// RefType implements refsvfs2.CheckedObject.Type.
+func (d *dentry) RefType() string {
+ return "gofer.dentry"
}
// LeakMessage implements refsvfs2.CheckedObject.LeakMessage.
@@ -1263,6 +1268,14 @@ func (d *dentry) LeakMessage() string {
return fmt.Sprintf("[gofer.dentry %p] reference count of %d instead of -1", d, atomic.LoadInt64(&d.refs))
}
+// LogRefs implements refsvfs2.CheckedObject.LogRefs.
+//
+// This should only be set to true for debugging purposes, as it can generate an
+// extremely large amount of output and drastically degrade performance.
+func (d *dentry) LogRefs() bool {
+ return false
+}
+
// InotifyWithParent implements vfs.DentryImpl.InotifyWithParent.
func (d *dentry) InotifyWithParent(ctx context.Context, events, cookie uint32, et vfs.EventType) {
if d.isDir() {
@@ -1486,17 +1499,10 @@ func (d *dentry) destroyLocked(ctx context.Context) {
// Drop the reference held by d on its parent without recursively locking
// d.fs.renameMu.
- if d.parent != nil {
- if refs := atomic.AddInt64(&d.parent.refs, -1); refs == 0 {
- d.parent.checkCachingLocked(ctx)
- } else if refs < 0 {
- panic("gofer.dentry.DecRef() called without holding a reference")
- }
- }
-
- if refsvfs2.LeakCheckEnabled() {
- refsvfs2.Unregister(d, "gofer.dentry")
+ if d.parent != nil && d.parent.decRefNoCaching() == 0 {
+ d.parent.checkCachingLocked(ctx)
}
+ refsvfs2.Unregister(d)
}
func (d *dentry) isDeleted() bool {
diff --git a/pkg/sentry/fsimpl/gofer/save_restore.go b/pkg/sentry/fsimpl/gofer/save_restore.go
index 2ea224c43..17849dcc0 100644
--- a/pkg/sentry/fsimpl/gofer/save_restore.go
+++ b/pkg/sentry/fsimpl/gofer/save_restore.go
@@ -140,8 +140,8 @@ 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")
+ if atomic.LoadInt64(&d.refs) != -1 {
+ refsvfs2.Register(d)
}
}
diff --git a/pkg/sentry/fsimpl/overlay/BUILD b/pkg/sentry/fsimpl/overlay/BUILD
index fd6c55921..bf13bbbf4 100644
--- a/pkg/sentry/fsimpl/overlay/BUILD
+++ b/pkg/sentry/fsimpl/overlay/BUILD
@@ -31,6 +31,7 @@ go_library(
"//pkg/context",
"//pkg/fspath",
"//pkg/log",
+ "//pkg/refs",
"//pkg/refsvfs2",
"//pkg/sentry/arch",
"//pkg/sentry/fs/lock",
diff --git a/pkg/sentry/fsimpl/overlay/overlay.go b/pkg/sentry/fsimpl/overlay/overlay.go
index c812f0a70..f6c58f2e7 100644
--- a/pkg/sentry/fsimpl/overlay/overlay.go
+++ b/pkg/sentry/fsimpl/overlay/overlay.go
@@ -505,9 +505,7 @@ func (fs *filesystem) newDentry() *dentry {
}
d.lowerVDs = d.inlineLowerVDs[:0]
d.vfsd.Init(d)
- if refsvfs2.LeakCheckEnabled() {
- refsvfs2.Register(d, "overlay.dentry")
- }
+ refsvfs2.Register(d)
return d
}
@@ -515,17 +513,19 @@ func (fs *filesystem) newDentry() *dentry {
func (d *dentry) IncRef() {
// d.refs may be 0 if d.fs.renameMu is locked, which serializes against
// d.checkDropLocked().
- atomic.AddInt64(&d.refs, 1)
+ r := atomic.AddInt64(&d.refs, 1)
+ refsvfs2.LogIncRef(d, r)
}
// TryIncRef implements vfs.DentryImpl.TryIncRef.
func (d *dentry) TryIncRef() bool {
for {
- refs := atomic.LoadInt64(&d.refs)
- if refs <= 0 {
+ r := atomic.LoadInt64(&d.refs)
+ if r <= 0 {
return false
}
- if atomic.CompareAndSwapInt64(&d.refs, refs, refs+1) {
+ if atomic.CompareAndSwapInt64(&d.refs, r, r+1) {
+ refsvfs2.LogTryIncRef(d, r+1)
return true
}
}
@@ -533,15 +533,27 @@ func (d *dentry) TryIncRef() bool {
// DecRef implements vfs.DentryImpl.DecRef.
func (d *dentry) DecRef(ctx context.Context) {
- if refs := atomic.AddInt64(&d.refs, -1); refs == 0 {
+ r := atomic.AddInt64(&d.refs, -1)
+ refsvfs2.LogDecRef(d, r)
+ if r == 0 {
d.fs.renameMu.Lock()
d.checkDropLocked(ctx)
d.fs.renameMu.Unlock()
- } else if refs < 0 {
+ } else if r < 0 {
panic("overlay.dentry.DecRef() called without holding a reference")
}
}
+func (d *dentry) decRefLocked(ctx context.Context) {
+ r := atomic.AddInt64(&d.refs, -1)
+ refsvfs2.LogDecRef(d, r)
+ if r == 0 {
+ d.checkDropLocked(ctx)
+ } else if r < 0 {
+ panic("overlay.dentry.decRefLocked() called without holding a reference")
+ }
+}
+
// checkDropLocked should be called after d's reference count becomes 0 or it
// becomes deleted.
//
@@ -601,15 +613,14 @@ func (d *dentry) destroyLocked(ctx context.Context) {
d.parent.dirMu.Unlock()
// Drop the reference held by d on its parent without recursively
// locking d.fs.renameMu.
- if refs := atomic.AddInt64(&d.parent.refs, -1); refs == 0 {
- d.parent.checkDropLocked(ctx)
- } else if refs < 0 {
- panic("overlay.dentry.DecRef() called without holding a reference")
- }
- }
- if refsvfs2.LeakCheckEnabled() {
- refsvfs2.Unregister(d, "overlay.dentry")
+ d.parent.decRefLocked(ctx)
}
+ refsvfs2.Unregister(d)
+}
+
+// RefType implements refsvfs2.CheckedObject.Type.
+func (d *dentry) RefType() string {
+ return "overlay.dentry"
}
// LeakMessage implements refsvfs2.CheckedObject.LeakMessage.
@@ -617,6 +628,14 @@ func (d *dentry) LeakMessage() string {
return fmt.Sprintf("[overlay.dentry %p] reference count of %d instead of -1", d, atomic.LoadInt64(&d.refs))
}
+// LogRefs implements refsvfs2.CheckedObject.LogRefs.
+//
+// This should only be set to true for debugging purposes, as it can generate an
+// extremely large amount of output and drastically degrade performance.
+func (d *dentry) LogRefs() bool {
+ return false
+}
+
// InotifyWithParent implements vfs.DentryImpl.InotifyWithParent.
func (d *dentry) InotifyWithParent(ctx context.Context, events uint32, cookie uint32, et vfs.EventType) {
if d.isDir() {
diff --git a/pkg/sentry/fsimpl/overlay/save_restore.go b/pkg/sentry/fsimpl/overlay/save_restore.go
index 054e17b17..54809f16c 100644
--- a/pkg/sentry/fsimpl/overlay/save_restore.go
+++ b/pkg/sentry/fsimpl/overlay/save_restore.go
@@ -21,7 +21,7 @@ import (
)
func (d *dentry) afterLoad() {
- if refsvfs2.LeakCheckEnabled() && atomic.LoadInt64(&d.refs) != -1 {
- refsvfs2.Register(d, "overlay.dentry")
+ if atomic.LoadInt64(&d.refs) != -1 {
+ refsvfs2.Register(d)
}
}
diff --git a/pkg/sentry/fsimpl/verity/save_restore.go b/pkg/sentry/fsimpl/verity/save_restore.go
index 4a161163c..46b064342 100644
--- a/pkg/sentry/fsimpl/verity/save_restore.go
+++ b/pkg/sentry/fsimpl/verity/save_restore.go
@@ -21,7 +21,7 @@ import (
)
func (d *dentry) afterLoad() {
- if refsvfs2.LeakCheckEnabled() && atomic.LoadInt64(&d.refs) != -1 {
- refsvfs2.Register(d, "verity.dentry")
+ if atomic.LoadInt64(&d.refs) != -1 {
+ refsvfs2.Register(d)
}
}
diff --git a/pkg/sentry/fsimpl/verity/verity.go b/pkg/sentry/fsimpl/verity/verity.go
index 92ca6ca6b..de92878fd 100644
--- a/pkg/sentry/fsimpl/verity/verity.go
+++ b/pkg/sentry/fsimpl/verity/verity.go
@@ -43,32 +43,41 @@ import (
"gvisor.dev/gvisor/pkg/usermem"
)
-// Name is the default filesystem name.
-const Name = "verity"
-
-// merklePrefix is the prefix of the Merkle tree files. For example, the Merkle
-// tree file for "/foo" is "/.merkle.verity.foo".
-const merklePrefix = ".merkle.verity."
-
-// merkleoffsetInParentXattr is the extended attribute name specifying the
-// offset of child hash in its parent's Merkle tree.
-const merkleOffsetInParentXattr = "user.merkle.offset"
-
-// merkleSizeXattr is the extended attribute name specifying the size of data
-// hashed by the corresponding Merkle tree. For a file, it's the size of the
-// whole file. For a directory, it's the size of all its children's hashes.
-const merkleSizeXattr = "user.merkle.size"
+const (
+ // Name is the default filesystem name.
+ Name = "verity"
+
+ // merklePrefix is the prefix of the Merkle tree files. For example, the Merkle
+ // tree file for "/foo" is "/.merkle.verity.foo".
+ merklePrefix = ".merkle.verity."
+
+ // merkleOffsetInParentXattr is the extended attribute name specifying the
+ // offset of the child hash in its parent's Merkle tree.
+ merkleOffsetInParentXattr = "user.merkle.offset"
+
+ // merkleSizeXattr is the extended attribute name specifying the size of data
+ // hashed by the corresponding Merkle tree. For a regular file, this is the
+ // file size. For a directory, this is the size of all its children's hashes.
+ merkleSizeXattr = "user.merkle.size"
+
+ // sizeOfStringInt32 is the size for a 32 bit integer stored as string in
+ // extended attributes. The maximum value of a 32 bit integer has 10 digits.
+ sizeOfStringInt32 = 10
+)
-// sizeOfStringInt32 is the size for a 32 bit integer stored as string in
-// extended attributes. The maximum value of a 32 bit integer is 10 digits.
-const sizeOfStringInt32 = 10
+var (
+ // noCrashOnVerificationFailure indicates whether the sandbox should panic
+ // whenever verification fails. If true, an error is returned instead of
+ // panicking. This should only be set for tests.
+ //
+ // TODO(b/165661693): Decide whether to panic or return error based on this
+ // flag.
+ noCrashOnVerificationFailure bool
-// noCrashOnVerificationFailure indicates whether the sandbox should panic
-// whenever verification fails. If true, an error is returned instead of
-// panicking. This should only be set for tests.
-// TOOD(b/165661693): Decide whether to panic or return error based on this
-// flag.
-var noCrashOnVerificationFailure bool
+ // verityMu synchronizes concurrent operations that enable verity and perform
+ // verification checks.
+ verityMu sync.RWMutex
+)
// FilesystemType implements vfs.FilesystemType.
//
@@ -334,25 +343,25 @@ func (fs *filesystem) newDentry() *dentry {
fs: fs,
}
d.vfsd.Init(d)
- if refsvfs2.LeakCheckEnabled() {
- refsvfs2.Register(d, "verity.dentry")
- }
+ refsvfs2.Register(d)
return d
}
// IncRef implements vfs.DentryImpl.IncRef.
func (d *dentry) IncRef() {
- atomic.AddInt64(&d.refs, 1)
+ r := atomic.AddInt64(&d.refs, 1)
+ refsvfs2.LogIncRef(d, r)
}
// TryIncRef implements vfs.DentryImpl.TryIncRef.
func (d *dentry) TryIncRef() bool {
for {
- refs := atomic.LoadInt64(&d.refs)
- if refs <= 0 {
+ r := atomic.LoadInt64(&d.refs)
+ if r <= 0 {
return false
}
- if atomic.CompareAndSwapInt64(&d.refs, refs, refs+1) {
+ if atomic.CompareAndSwapInt64(&d.refs, r, r+1) {
+ refsvfs2.LogTryIncRef(d, r+1)
return true
}
}
@@ -360,15 +369,27 @@ func (d *dentry) TryIncRef() bool {
// DecRef implements vfs.DentryImpl.DecRef.
func (d *dentry) DecRef(ctx context.Context) {
- if refs := atomic.AddInt64(&d.refs, -1); refs == 0 {
+ r := atomic.AddInt64(&d.refs, -1)
+ refsvfs2.LogDecRef(d, r)
+ if r == 0 {
d.fs.renameMu.Lock()
d.checkDropLocked(ctx)
d.fs.renameMu.Unlock()
- } else if refs < 0 {
+ } else if r < 0 {
panic("verity.dentry.DecRef() called without holding a reference")
}
}
+func (d *dentry) decRefLocked(ctx context.Context) {
+ r := atomic.AddInt64(&d.refs, -1)
+ refsvfs2.LogDecRef(d, r)
+ if r == 0 {
+ d.checkDropLocked(ctx)
+ } else if r < 0 {
+ panic("verity.dentry.decRefLocked() called without holding a reference")
+ }
+}
+
// checkDropLocked should be called after d's reference count becomes 0 or it
// becomes deleted.
func (d *dentry) checkDropLocked(ctx context.Context) {
@@ -399,26 +420,23 @@ func (d *dentry) destroyLocked(ctx context.Context) {
if d.lowerVD.Ok() {
d.lowerVD.DecRef(ctx)
}
- if refsvfs2.LeakCheckEnabled() {
- refsvfs2.Unregister(d, "verity.dentry")
- }
-
if d.lowerMerkleVD.Ok() {
d.lowerMerkleVD.DecRef(ctx)
}
-
if d.parent != nil {
d.parent.dirMu.Lock()
if !d.vfsd.IsDead() {
delete(d.parent.children, d.name)
}
d.parent.dirMu.Unlock()
- if refs := atomic.AddInt64(&d.parent.refs, -1); refs == 0 {
- d.parent.checkDropLocked(ctx)
- } else if refs < 0 {
- panic("verity.dentry.DecRef() called without holding a reference")
- }
+ d.parent.decRefLocked(ctx)
}
+ refsvfs2.Unregister(d)
+}
+
+// RefType implements refsvfs2.CheckedObject.Type.
+func (d *dentry) RefType() string {
+ return "verity.dentry"
}
// LeakMessage implements refsvfs2.CheckedObject.LeakMessage.
@@ -426,6 +444,14 @@ func (d *dentry) LeakMessage() string {
return fmt.Sprintf("[verity.dentry %p] reference count of %d instead of -1", d, atomic.LoadInt64(&d.refs))
}
+// LogRefs implements refsvfs2.CheckedObject.LogRefs.
+//
+// This should only be set to true for debugging purposes, as it can generate an
+// extremely large amount of output and drastically degrade performance.
+func (d *dentry) LogRefs() bool {
+ return false
+}
+
// InotifyWithParent implements vfs.DentryImpl.InotifyWithParent.
func (d *dentry) InotifyWithParent(ctx context.Context, events, cookie uint32, et vfs.EventType) {
//TODO(b/159261227): Implement InotifyWithParent.
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-18 19:37:21 +0000