nfs4: squash opens only if open_owners are the same

Fixes: 9288056 ("nfs4: voluntarily offer delegation id there are multiple opens on the file")

Motivation:
The NFSv4.x server allowed to merge different opens only if they comes
from the same client and owner, as per rfc 7530

Modification:
check owners before merging states.
added unit test

Result:
regression fixed, better spec compliance

Acked-by: Marina Sahakyan
Target: master, 0.27
(cherry picked from commit 6e33634)
Signed-off-by: Tigran Mkrtchyan <[email protected]>

Author: kofemann

core/src/main/java/org/dcache/nfs/v4/FileTracker.java

@@ -311,7 +311,7 @@ public OpenRecord addOpen(NFS4Client client, StateOwner owner, Inode inode, int
             // access mode and return the same stateid as required by rfc5661#18.16.3
 
             for (OpenState os : opens) {
-                if (os.client.getId() == client.getId()) {
+                if (os.client.getId() == client.getId() && os.getOwner().equals(owner)) {
                         os.shareAccess |= shareAccess;
                         os.shareDeny |= shareDeny;
 

core/src/test/java/org/dcache/nfs/v4/FileTrackerTest.java

@@ -93,6 +93,21 @@ public void shouldReturnSameStateIdForSameClient() throws Exception {
         assertEquals("New stateid returned", openRecord1.openStateId(), openRecord2.openStateId());
     }
 
+    @Test
+    public void shouldReturnDifferentStateIdForDifferentOwners() throws Exception {
+
+        NFS4Client client1 = createClient(sh);
+        StateOwner stateOwner1 = client1.getOrCreateOwner("client1".getBytes(StandardCharsets.UTF_8), new seqid4(0));
+        StateOwner stateOwner2 = client1.getOrCreateOwner("client2".getBytes(StandardCharsets.UTF_8), new seqid4(0));
+
+        nfs_fh4 fh = generateFileHandle();
+        Inode inode = Inode.forFile(fh.value);
+
+        var openRecord1 = tracker.addOpen(client1, stateOwner1, inode, OPEN4_SHARE_ACCESS_READ, 0);
+        var openRecord2 = tracker.addOpen(client1, stateOwner2, inode, OPEN4_SHARE_ACCESS_READ, 0);
+        assertNotEquals("Same stateid for different owners returned", openRecord1.openStateId(), openRecord2.openStateId());
+    }
+
     @Test
     public void shouldMergeAccessModesOnMultipleOpenes() throws Exception {