lib/fs: Consider options in case-fs caching (fixes #7371) (#7381)

lib/fs/casefs.go

@@ -43,8 +43,8 @@ type realCaser interface {
 }
 
 type fskey struct {
-	fstype FilesystemType
-	uri    string
+	fstype    FilesystemType
+	uri, opts string
 }
 
 // caseFilesystemRegistry caches caseFilesystems and runs a routine to drop
@@ -55,8 +55,22 @@ type caseFilesystemRegistry struct {
 	startCleaner sync.Once
 }
 
-func (r *caseFilesystemRegistry) get(fs Filesystem) Filesystem {
-	k := fskey{fs.Type(), fs.URI()}
+func newFSKey(fs Filesystem, opts ...Option) fskey {
+	k := fskey{
+		fstype: fs.Type(),
+		uri:    fs.URI(),
+	}
+	if len(opts) > 0 {
+		k.opts = opts[0].id
+		for _, o := range opts[1:] {
+			k.opts += "&" + o.id
+		}
+	}
+	return k
+}
+
+func (r *caseFilesystemRegistry) get(fs Filesystem, opts ...Option) Filesystem {
+	k := newFSKey(fs, opts...)
 
 	// Use double locking when getting a caseFs. In the common case it will
 	// already exist and we take the read lock fast path. If it doesn't, we
@@ -122,8 +136,10 @@ type caseFilesystem struct {
 // from the real path. It is safe to use with any filesystem, i.e. also a
 // case-sensitive one. However it will add some overhead and thus shouldn't be
 // used if the filesystem is known to already behave case-sensitively.
-func NewCaseFilesystem(fs Filesystem) Filesystem {
-	return wrapFilesystem(fs, globalCaseFilesystemRegistry.get)
+func NewCaseFilesystem(fs Filesystem, opts ...Option) Filesystem {
+	return wrapFilesystem(fs, func(fs Filesystem) Filesystem {
+		return globalCaseFilesystemRegistry.get(fs, opts...)
+	})
 }
 
 func (f *caseFilesystem) Chmod(name string, mode FileMode) error {