Patch "SMB3: Do not send lease break acknowledgment if all file handles have been closed" has been added to the 6.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    SMB3: Do not send lease break acknowledgment if all file handles have been closed

to the 6.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     smb3-do-not-send-lease-break-acknowledgment-if-all-f.patch
and it can be found in the queue-6.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit a94eb2e45651f5c0e0cd9daa6674950176d05c22
Author: Bharath SM <bharathsm@xxxxxxxxxxxxx>
Date:   Sun Jun 18 19:02:24 2023 +0000

    SMB3: Do not send lease break acknowledgment if all file handles have been closed
    
    [ Upstream commit da787d5b74983f7525d1eb4b9c0b4aff2821511a ]
    
    In case if all existing file handles are deferred handles and if all of
    them gets closed due to handle lease break then we dont need to send
    lease break acknowledgment to server, because last handle close will be
    considered as lease break ack.
    After closing deferred handels, we check for openfile list of inode,
    if its empty then we skip sending lease break ack.
    
    Fixes: 59a556aebc43 ("SMB3: drop reference to cfile before sending oplock break")
    Reviewed-by: Tom Talpey <tom@xxxxxxxxxx>
    Signed-off-by: Bharath SM <bharathsm@xxxxxxxxxxxxx>
    Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
index 051283386e229..1a854dc204823 100644
--- a/fs/smb/client/file.c
+++ b/fs/smb/client/file.c
@@ -4936,20 +4936,19 @@ void cifs_oplock_break(struct work_struct *work)
 
 	_cifsFileInfo_put(cfile, false /* do not wait for ourself */, false);
 	/*
-	 * releasing stale oplock after recent reconnect of smb session using
-	 * a now incorrect file handle is not a data integrity issue but do
-	 * not bother sending an oplock release if session to server still is
-	 * disconnected since oplock already released by the server
+	 * MS-SMB2 3.2.5.19.1 and 3.2.5.19.2 (and MS-CIFS 3.2.5.42) do not require
+	 * an acknowledgment to be sent when the file has already been closed.
+	 * check for server null, since can race with kill_sb calling tree disconnect.
 	 */
-	if (!oplock_break_cancelled) {
-		/* check for server null since can race with kill_sb calling tree disconnect */
-		if (tcon->ses && tcon->ses->server) {
-			rc = tcon->ses->server->ops->oplock_response(tcon, persistent_fid,
-				volatile_fid, net_fid, cinode);
-			cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
-		} else
-			pr_warn_once("lease break not sent for unmounted share\n");
-	}
+	spin_lock(&cinode->open_file_lock);
+	if (tcon->ses && tcon->ses->server && !oplock_break_cancelled &&
+					!list_empty(&cinode->openFileList)) {
+		spin_unlock(&cinode->open_file_lock);
+		rc = tcon->ses->server->ops->oplock_response(tcon, persistent_fid,
+						volatile_fid, net_fid, cinode);
+		cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
+	} else
+		spin_unlock(&cinode->open_file_lock);
 
 	cifs_done_oplock_break(cinode);
 }