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authorgVisor bot <gvisor-bot@google.com>2021-11-02 19:34:05 +0000
committergVisor bot <gvisor-bot@google.com>2021-11-02 19:34:05 +0000
commit06c496f54fd0700ca8252ede5843575440ceb9b3 (patch)
tree5c18875817c206aa24e1c4c9c0d4560f0467628e
parent04d474e716e094266534c791188bea5e36fe5dda (diff)
parent1e1d6b2be37873c5e62461834df973f41565c662 (diff)
Merge release-20211026.0-22-g1e1d6b2be (automated)
-rw-r--r--pkg/p9/file.go35
-rw-r--r--pkg/p9/handlers.go6
-rw-r--r--pkg/p9/server.go9
-rw-r--r--runsc/fsgofer/fsgofer.go11
4 files changed, 54 insertions, 7 deletions
diff --git a/pkg/p9/file.go b/pkg/p9/file.go
index 8d6af2d6b..b4b556cb9 100644
--- a/pkg/p9/file.go
+++ b/pkg/p9/file.go
@@ -21,13 +21,37 @@ import (
"gvisor.dev/gvisor/pkg/fd"
)
+// AttacherOptions contains Attacher configuration.
+type AttacherOptions struct {
+ // SetAttrOnDeleted is set to true if it's safe to call File.SetAttr for
+ // deleted files.
+ SetAttrOnDeleted bool
+
+ // AllocateOnDeleted is set to true if it's safe to call File.Allocate for
+ // deleted files.
+ AllocateOnDeleted bool
+}
+
+// NoServerOptions partially implements Attacher with empty AttacherOptions.
+type NoServerOptions struct{}
+
+// ServerOptions implements Attacher.
+func (*NoServerOptions) ServerOptions() AttacherOptions {
+ return AttacherOptions{}
+}
+
// Attacher is provided by the server.
type Attacher interface {
// Attach returns a new File.
//
- // The client-side attach will be translate to a series of walks from
+ // The client-side attach will be translated to a series of walks from
// the file returned by this Attach call.
Attach() (File, error)
+
+ // ServerOptions returns configuration options for this attach point.
+ //
+ // This is never caller in the client-side.
+ ServerOptions() AttacherOptions
}
// File is a set of operations corresponding to a single node.
@@ -301,7 +325,7 @@ type File interface {
type DefaultWalkGetAttr struct{}
// WalkGetAttr implements File.WalkGetAttr.
-func (DefaultWalkGetAttr) WalkGetAttr([]string) ([]QID, File, AttrMask, Attr, error) {
+func (*DefaultWalkGetAttr) WalkGetAttr([]string) ([]QID, File, AttrMask, Attr, error) {
return nil, nil, AttrMask{}, Attr{}, unix.ENOSYS
}
@@ -309,7 +333,7 @@ func (DefaultWalkGetAttr) WalkGetAttr([]string) ([]QID, File, AttrMask, Attr, er
type DisallowClientCalls struct{}
// SetAttrClose implements File.SetAttrClose.
-func (DisallowClientCalls) SetAttrClose(SetAttrMask, SetAttr) error {
+func (*DisallowClientCalls) SetAttrClose(SetAttrMask, SetAttr) error {
panic("SetAttrClose should not be called on the server")
}
@@ -321,6 +345,11 @@ func (*DisallowServerCalls) Renamed(File, string) {
panic("Renamed should not be called on the client")
}
+// ServerOptions implements Attacher.
+func (*DisallowServerCalls) ServerOptions() AttacherOptions {
+ panic("ServerOptions should not be called on the client")
+}
+
// DefaultMultiGetAttr implements File.MultiGetAttr() on top of File.
func DefaultMultiGetAttr(start File, names []string) ([]FullStat, error) {
stats := make([]FullStat, 0, len(names))
diff --git a/pkg/p9/handlers.go b/pkg/p9/handlers.go
index 2657081e3..c85af5e9e 100644
--- a/pkg/p9/handlers.go
+++ b/pkg/p9/handlers.go
@@ -178,7 +178,7 @@ func (t *Tsetattrclunk) handle(cs *connState) message {
// This might be technically incorrect, as it's possible that
// there were multiple links and you can still change the
// corresponding inode information.
- if ref.isDeleted() {
+ if !cs.server.options.SetAttrOnDeleted && ref.isDeleted() {
return unix.EINVAL
}
@@ -913,7 +913,7 @@ func (t *Tsetattr) handle(cs *connState) message {
// This might be technically incorrect, as it's possible that
// there were multiple links and you can still change the
// corresponding inode information.
- if ref.isDeleted() {
+ if !cs.server.options.SetAttrOnDeleted && ref.isDeleted() {
return unix.EINVAL
}
@@ -946,7 +946,7 @@ func (t *Tallocate) handle(cs *connState) message {
}
// We don't allow allocate on files that have been deleted.
- if ref.isDeleted() {
+ if !cs.server.options.AllocateOnDeleted && ref.isDeleted() {
return unix.EINVAL
}
diff --git a/pkg/p9/server.go b/pkg/p9/server.go
index 6428ad745..e7d129f9d 100644
--- a/pkg/p9/server.go
+++ b/pkg/p9/server.go
@@ -34,6 +34,8 @@ type Server struct {
// attacher provides the attach function.
attacher Attacher
+ options AttacherOptions
+
// pathTree is the full set of paths opened on this server.
//
// These may be across different connections, but rename operations
@@ -48,10 +50,15 @@ type Server struct {
renameMu sync.RWMutex
}
-// NewServer returns a new server.
+// NewServer returns a new server. attacher may be nil.
func NewServer(attacher Attacher) *Server {
+ opts := AttacherOptions{}
+ if attacher != nil {
+ opts = attacher.ServerOptions()
+ }
return &Server{
attacher: attacher,
+ options: opts,
pathTree: newPathNode(),
}
}
diff --git a/runsc/fsgofer/fsgofer.go b/runsc/fsgofer/fsgofer.go
index 600b21189..3d610199c 100644
--- a/runsc/fsgofer/fsgofer.go
+++ b/runsc/fsgofer/fsgofer.go
@@ -140,6 +140,17 @@ func (a *attachPoint) Attach() (p9.File, error) {
return lf, nil
}
+// ServerOptions implements p9.Attacher. It's safe to call SetAttr and Allocate
+// on deleted files because fsgofer either uses an existing FD or opens a new
+// one using the magic symlink in `/proc/[pid]/fd` and cannot mistakely open
+// a file that was created in the same path as the delete file.
+func (a *attachPoint) ServerOptions() p9.AttacherOptions {
+ return p9.AttacherOptions{
+ SetAttrOnDeleted: true,
+ AllocateOnDeleted: true,
+ }
+}
+
// makeQID returns a unique QID for the given stat buffer.
func (a *attachPoint) makeQID(stat *unix.Stat_t) p9.QID {
a.deviceMu.Lock()