Extract dh.Seek() from ReadDir()

yandex-cloud · Jun 9, 2023 · 96589d6 · 96589d6
1 parent 2688d6d
commit 96589d6
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Showing 2 changed files with 30 additions and 25 deletions.
diff --git a/internal/dir.go b/internal/dir.go
@@ -650,6 +650,35 @@ func (dh *DirHandle) loadListing() error {
 	return nil
 }
 
+// LOCKS_REQUIRED(dh.mu)
+func (dh *DirHandle) Seek(newOffset fuseops.DirOffset) {
+	if newOffset != 0 && newOffset != dh.lastExternalOffset {
+		// Do our best to support directory seeks even though we can't guarantee
+		// consistent listings in this case (i.e. files may be duplicated or skipped on changes)
+		// 'Normal' software doesn't seek within the directory.
+		// nfs-kernel-server, though, does: it closes the dir between paged listing calls.
+		fuseLog.Debugf("Directory seek from %v to %v in %v", newOffset, dh.lastExternalOffset, dh.inode.FullName())
+		dh.inode.mu.Lock()
+		dh.lastExternalOffset = newOffset
+		dh.lastInternalOffset = int(newOffset)
+		if dh.lastInternalOffset > len(dh.inode.dir.Children) {
+			dh.lastInternalOffset = len(dh.inode.dir.Children)
+		}
+		if len(dh.inode.dir.Children) > 0 {
+			dh.inode.dir.Children[dh.lastInternalOffset-1].mu.Lock()
+			dh.lastName = dh.inode.dir.Children[dh.lastInternalOffset-1].Name
+			dh.inode.dir.Children[dh.lastInternalOffset-1].mu.Unlock()
+		} else {
+			dh.lastName = ""
+		}
+		dh.inode.mu.Unlock()
+	} else if newOffset == 0 {
+		dh.lastExternalOffset = 0
+		dh.lastInternalOffset = 0
+		dh.lastName = ""
+	}
+}
+
 // LOCKS_REQUIRED(dh.mu)
 // LOCKS_EXCLUDED(dh.inode.mu)
 // LOCKS_EXCLUDED(dh.inode.fs)

diff --git a/internal/goofys.go b/internal/goofys.go
@@ -1275,31 +1275,7 @@ func (fs *Goofys) ReadDir(
 
 	dh.mu.Lock()
 
-	if op.Offset != 0 && op.Offset != dh.lastExternalOffset {
-		// Do our best to support directory seeks even though we can't guarantee
-		// consistent listings in this case (i.e. files may be duplicated or skipped on changes)
-		// 'Normal' software doesn't seek within the directory.
-		// nfs-kernel-server, though, does: it closes the dir between paged listing calls.
-		fuseLog.Debugf("Directory seek from %v to %v in %v", op.Offset, dh.lastExternalOffset, inode.FullName())
-		inode.mu.Lock()
-		dh.lastExternalOffset = op.Offset
-		dh.lastInternalOffset = int(op.Offset)
-		if dh.lastInternalOffset > len(inode.dir.Children) {
-			dh.lastInternalOffset = len(inode.dir.Children)
-		}
-		if len(inode.dir.Children) > 0 {
-			inode.dir.Children[dh.lastInternalOffset-1].mu.Lock()
-			dh.lastName = inode.dir.Children[dh.lastInternalOffset-1].Name
-			inode.dir.Children[dh.lastInternalOffset-1].mu.Unlock()
-		} else {
-			dh.lastName = ""
-		}
-		inode.mu.Unlock()
-	} else if op.Offset == 0 {
-		dh.lastExternalOffset = 0
-		dh.lastInternalOffset = 0
-		dh.lastName = ""
-	}
+	dh.Seek(op.Offset)
 
 	for {
 		e, err := dh.ReadDir(dh.lastInternalOffset, dh.lastExternalOffset)