fusefrontend: upgrade wlockMap to use device AND inode number

If there are multiple filesystems backing the gocryptfs filesystems
inode numbers are not guaranteed to be unique.

2 files changed, 3 insertions, 8 deletions

diff --git a/internal/fusefrontend_reverse/ino_map.go b/internal/fusefrontend_reverse/ino_map.go
index 9412343..dae8222 100644
--- a/internal/fusefrontend_reverse/ino_map.go
+++ b/internal/fusefrontend_reverse/ino_map.go
@@ -17,8 +17,3 @@ type inoGenT struct {
 func (i *inoGenT) next() uint64 {
 	return atomic.AddUint64(i.ino, 1)
 }
-
-type devIno struct {
-	dev uint64
-	ino uint64
-}
diff --git a/internal/fusefrontend_reverse/rfs.go b/internal/fusefrontend_reverse/rfs.go
index 7f102cf..aca4b90 100644
--- a/internal/fusefrontend_reverse/rfs.go
+++ b/internal/fusefrontend_reverse/rfs.go
@@ -41,7 +41,7 @@ type ReverseFS struct {
 	// Inode number generator
 	inoGen *inoGenT
 	// Maps backing files device+inode pairs to user-facing unique inode numbers
-	inoMap map[devIno]uint64
+	inoMap map[fusefrontend.DevInoStruct]uint64
 	// Protects map access
 	inoMapLock sync.Mutex
 }
@@ -68,7 +68,7 @@ func NewFS(args fusefrontend.Args) *ReverseFS {
 		nameTransform: nameTransform,
 		contentEnc:    contentEnc,
 		inoGen:        newInoGen(),
-		inoMap:        map[devIno]uint64{},
+		inoMap:        map[fusefrontend.DevInoStruct]uint64{},
 	}
 }
 
@@ -167,7 +167,7 @@ func (rfs *ReverseFS) inoAwareStat(relPlainPath string) (*fuse.Attr, fuse.Status
 	// The file has hard links. We have to give it a stable inode number so
 	// tar or rsync can find them.
 	if fi.Mode().IsRegular() && st.Nlink > 1 {
-		di := devIno{uint64(st.Dev), st.Ino}
+		di := fusefrontend.DevInoFromStat(st)
 		rfs.inoMapLock.Lock()
 		stableIno := rfs.inoMap[di]
 		if stableIno == 0 {