diff options
Diffstat (limited to 'pkg/sentry/fs/fsutil/inode_cached.go')
| -rw-r--r-- | pkg/sentry/fs/fsutil/inode_cached.go | 34 |
1 files changed, 25 insertions, 9 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 |