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-rw-r--r--pkg/sentry/fs/fsutil/inode_cached.go34
-rw-r--r--pkg/sentry/fs/fsutil/inode_cached_test.go10
-rw-r--r--pkg/sentry/fs/gofer/fs.go22
-rw-r--r--pkg/sentry/fs/gofer/session.go27
-rw-r--r--pkg/sentry/fs/host/inode.go6
5 files changed, 68 insertions, 31 deletions
diff --git a/pkg/sentry/fs/fsutil/inode_cached.go b/pkg/sentry/fs/fsutil/inode_cached.go
index e70bc28fb..20cb9a367 100644
--- a/pkg/sentry/fs/fsutil/inode_cached.go
+++ b/pkg/sentry/fs/fsutil/inode_cached.go
@@ -66,10 +66,8 @@ type CachingInodeOperations struct {
// mfp is used to allocate memory that caches backingFile's contents.
mfp pgalloc.MemoryFileProvider
- // forcePageCache indicates the sentry page cache should be used regardless
- // of whether the platform supports host mapped I/O or not. This must not be
- // modified after inode creation.
- forcePageCache bool
+ // opts contains options. opts is immutable.
+ opts CachingInodeOperationsOptions
attrMu sync.Mutex `state:"nosave"`
@@ -116,6 +114,20 @@ type CachingInodeOperations struct {
refs frameRefSet
}
+// CachingInodeOperationsOptions configures a CachingInodeOperations.
+//
+// +stateify savable
+type CachingInodeOperationsOptions struct {
+ // If ForcePageCache is true, use the sentry page cache even if a host file
+ // descriptor is available.
+ ForcePageCache bool
+
+ // If LimitHostFDTranslation is true, apply maxFillRange() constraints to
+ // host file descriptor mappings returned by
+ // CachingInodeOperations.Translate().
+ LimitHostFDTranslation bool
+}
+
// CachedFileObject is a file that may require caching.
type CachedFileObject interface {
// ReadToBlocksAt reads up to dsts.NumBytes() bytes from the file to dsts,
@@ -159,7 +171,7 @@ type CachedFileObject interface {
// NewCachingInodeOperations returns a new CachingInodeOperations backed by
// a CachedFileObject and its initial unstable attributes.
-func NewCachingInodeOperations(ctx context.Context, backingFile CachedFileObject, uattr fs.UnstableAttr, forcePageCache bool) *CachingInodeOperations {
+func NewCachingInodeOperations(ctx context.Context, backingFile CachedFileObject, uattr fs.UnstableAttr, opts CachingInodeOperationsOptions) *CachingInodeOperations {
mfp := pgalloc.MemoryFileProviderFromContext(ctx)
if mfp == nil {
panic(fmt.Sprintf("context.Context %T lacks non-nil value for key %T", ctx, pgalloc.CtxMemoryFileProvider))
@@ -167,7 +179,7 @@ func NewCachingInodeOperations(ctx context.Context, backingFile CachedFileObject
return &CachingInodeOperations{
backingFile: backingFile,
mfp: mfp,
- forcePageCache: forcePageCache,
+ opts: opts,
attr: uattr,
hostFileMapper: NewHostFileMapper(),
}
@@ -763,7 +775,7 @@ func (rw *inodeReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error
// and memory mappings, and false if c.cache may contain data cached from
// c.backingFile.
func (c *CachingInodeOperations) useHostPageCache() bool {
- return !c.forcePageCache && c.backingFile.FD() >= 0
+ return !c.opts.ForcePageCache && c.backingFile.FD() >= 0
}
// AddMapping implements memmap.Mappable.AddMapping.
@@ -835,11 +847,15 @@ func (c *CachingInodeOperations) CopyMapping(ctx context.Context, ms memmap.Mapp
func (c *CachingInodeOperations) Translate(ctx context.Context, required, optional memmap.MappableRange, at usermem.AccessType) ([]memmap.Translation, error) {
// Hot path. Avoid defer.
if c.useHostPageCache() {
+ mr := optional
+ if c.opts.LimitHostFDTranslation {
+ mr = maxFillRange(required, optional)
+ }
return []memmap.Translation{
{
- Source: optional,
+ Source: mr,
File: c,
- Offset: optional.Start,
+ Offset: mr.Start,
Perms: usermem.AnyAccess,
},
}, nil
diff --git a/pkg/sentry/fs/fsutil/inode_cached_test.go b/pkg/sentry/fs/fsutil/inode_cached_test.go
index dc19255ed..eb5730c35 100644
--- a/pkg/sentry/fs/fsutil/inode_cached_test.go
+++ b/pkg/sentry/fs/fsutil/inode_cached_test.go
@@ -61,7 +61,7 @@ func TestSetPermissions(t *testing.T) {
uattr := fs.WithCurrentTime(ctx, fs.UnstableAttr{
Perms: fs.FilePermsFromMode(0444),
})
- iops := NewCachingInodeOperations(ctx, noopBackingFile{}, uattr, false /*forcePageCache*/)
+ iops := NewCachingInodeOperations(ctx, noopBackingFile{}, uattr, CachingInodeOperationsOptions{})
defer iops.Release()
perms := fs.FilePermsFromMode(0777)
@@ -150,7 +150,7 @@ func TestSetTimestamps(t *testing.T) {
ModificationTime: epoch,
StatusChangeTime: epoch,
}
- iops := NewCachingInodeOperations(ctx, noopBackingFile{}, uattr, false /*forcePageCache*/)
+ iops := NewCachingInodeOperations(ctx, noopBackingFile{}, uattr, CachingInodeOperationsOptions{})
defer iops.Release()
if err := iops.SetTimestamps(ctx, nil, test.ts); err != nil {
@@ -188,7 +188,7 @@ func TestTruncate(t *testing.T) {
uattr := fs.UnstableAttr{
Size: 0,
}
- iops := NewCachingInodeOperations(ctx, noopBackingFile{}, uattr, false /*forcePageCache*/)
+ iops := NewCachingInodeOperations(ctx, noopBackingFile{}, uattr, CachingInodeOperationsOptions{})
defer iops.Release()
if err := iops.Truncate(ctx, nil, uattr.Size); err != nil {
@@ -280,7 +280,7 @@ func TestRead(t *testing.T) {
uattr := fs.UnstableAttr{
Size: int64(len(buf)),
}
- iops := NewCachingInodeOperations(ctx, newSliceBackingFile(buf), uattr, false /*forcePageCache*/)
+ iops := NewCachingInodeOperations(ctx, newSliceBackingFile(buf), uattr, CachingInodeOperationsOptions{})
defer iops.Release()
// Expect the cache to be initially empty.
@@ -336,7 +336,7 @@ func TestWrite(t *testing.T) {
uattr := fs.UnstableAttr{
Size: int64(len(buf)),
}
- iops := NewCachingInodeOperations(ctx, newSliceBackingFile(buf), uattr, false /*forcePageCache*/)
+ iops := NewCachingInodeOperations(ctx, newSliceBackingFile(buf), uattr, CachingInodeOperationsOptions{})
defer iops.Release()
// Expect the cache to be initially empty.
diff --git a/pkg/sentry/fs/gofer/fs.go b/pkg/sentry/fs/gofer/fs.go
index 69999dc28..8f8ab5d29 100644
--- a/pkg/sentry/fs/gofer/fs.go
+++ b/pkg/sentry/fs/gofer/fs.go
@@ -54,6 +54,10 @@ const (
// sandbox using files backed by the gofer. If set to false, unix sockets
// cannot be bound to gofer files without an overlay on top.
privateUnixSocketKey = "privateunixsocket"
+
+ // If present, sets CachingInodeOperationsOptions.LimitHostFDTranslation to
+ // true.
+ limitHostFDTranslationKey = "limit_host_fd_translation"
)
// defaultAname is the default attach name.
@@ -134,12 +138,13 @@ func (f *filesystem) Mount(ctx context.Context, device string, flags fs.MountSou
// opts are parsed 9p mount options.
type opts struct {
- fd int
- aname string
- policy cachePolicy
- msize uint32
- version string
- privateunixsocket bool
+ fd int
+ aname string
+ policy cachePolicy
+ msize uint32
+ version string
+ privateunixsocket bool
+ limitHostFDTranslation bool
}
// options parses mount(2) data into structured options.
@@ -237,6 +242,11 @@ func options(data string) (opts, error) {
delete(options, privateUnixSocketKey)
}
+ if _, ok := options[limitHostFDTranslationKey]; ok {
+ o.limitHostFDTranslation = true
+ delete(options, limitHostFDTranslationKey)
+ }
+
// Fail to attach if the caller wanted us to do something that we
// don't support.
if len(options) > 0 {
diff --git a/pkg/sentry/fs/gofer/session.go b/pkg/sentry/fs/gofer/session.go
index 69d08a627..50da865c1 100644
--- a/pkg/sentry/fs/gofer/session.go
+++ b/pkg/sentry/fs/gofer/session.go
@@ -117,6 +117,11 @@ type session struct {
// Flags provided to the mount.
superBlockFlags fs.MountSourceFlags `state:"wait"`
+ // limitHostFDTranslation is the value used for
+ // CachingInodeOperationsOptions.LimitHostFDTranslation for all
+ // CachingInodeOperations created by the session.
+ limitHostFDTranslation bool
+
// connID is a unique identifier for the session connection.
connID string `state:"wait"`
@@ -218,8 +223,11 @@ func newInodeOperations(ctx context.Context, s *session, file contextFile, qid p
uattr := unstable(ctx, valid, attr, s.mounter, s.client)
return sattr, &inodeOperations{
- fileState: fileState,
- cachingInodeOps: fsutil.NewCachingInodeOperations(ctx, fileState, uattr, s.superBlockFlags.ForcePageCache),
+ fileState: fileState,
+ cachingInodeOps: fsutil.NewCachingInodeOperations(ctx, fileState, uattr, fsutil.CachingInodeOperationsOptions{
+ ForcePageCache: s.superBlockFlags.ForcePageCache,
+ LimitHostFDTranslation: s.limitHostFDTranslation,
+ }),
}
}
@@ -242,13 +250,14 @@ func Root(ctx context.Context, dev string, filesystem fs.Filesystem, superBlockF
// Construct the session.
s := session{
- connID: dev,
- msize: o.msize,
- version: o.version,
- cachePolicy: o.policy,
- aname: o.aname,
- superBlockFlags: superBlockFlags,
- mounter: mounter,
+ connID: dev,
+ msize: o.msize,
+ version: o.version,
+ cachePolicy: o.policy,
+ aname: o.aname,
+ superBlockFlags: superBlockFlags,
+ limitHostFDTranslation: o.limitHostFDTranslation,
+ mounter: mounter,
}
s.EnableLeakCheck("gofer.session")
diff --git a/pkg/sentry/fs/host/inode.go b/pkg/sentry/fs/host/inode.go
index 679d8321a..894ab01f0 100644
--- a/pkg/sentry/fs/host/inode.go
+++ b/pkg/sentry/fs/host/inode.go
@@ -200,8 +200,10 @@ func newInode(ctx context.Context, msrc *fs.MountSource, fd int, saveable bool,
// Build the fs.InodeOperations.
uattr := unstableAttr(msrc.MountSourceOperations.(*superOperations), &s)
iops := &inodeOperations{
- fileState: fileState,
- cachingInodeOps: fsutil.NewCachingInodeOperations(ctx, fileState, uattr, msrc.Flags.ForcePageCache),
+ fileState: fileState,
+ cachingInodeOps: fsutil.NewCachingInodeOperations(ctx, fileState, uattr, fsutil.CachingInodeOperationsOptions{
+ ForcePageCache: msrc.Flags.ForcePageCache,
+ }),
}
// Return the fs.Inode.
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-15 17:43:42 +0000