From: Ronnie Sahlberg <lsahlber@redhat.com>
Date: Thu, 14 Nov 2019 12:32:12 -0600
Subject: [PATCH] smb3: add debug messages for closing unmatched open
Git-commit: 87bc2376fffae6821869c988edbb45a14527b258
References: bsc#1144333
Patch-mainline: v5.5-rc1

Helps distinguish between an interrupted close and a truly
unmatched open.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Paulo Alcantara <palcantara@suse.de>
---
 fs/cifs/cifsglob.h |  2 ++
 fs/cifs/smb2misc.c | 42 ++++++++++++++++++++++++++++++++----------
 2 files changed, 34 insertions(+), 10 deletions(-)

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 5d2dd04b55a6..57453226469d 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1552,6 +1552,8 @@ struct close_cancelled_open {
 	struct cifs_fid         fid;
 	struct cifs_tcon        *tcon;
 	struct work_struct      work;
+	__u64 mid;
+	__u16 cmd;
 };
 
 /*	Make code in transport.c a little cleaner by moving
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index 5668fb7d94e5..289915f0915d 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -729,19 +729,35 @@ smb2_cancelled_close_fid(struct work_struct *work)
 {
 	struct close_cancelled_open *cancelled = container_of(work,
 					struct close_cancelled_open, work);
+	struct cifs_tcon *tcon = cancelled->tcon;
+	int rc;
 
-	cifs_dbg(VFS, "Close unmatched open\n");
+	if (cancelled->mid)
+		cifs_tcon_dbg(VFS, "Close unmatched open for MID:%llx\n",
+			      cancelled->mid);
+	else
+		cifs_tcon_dbg(VFS, "Close interrupted close\n");
 
-	SMB2_close(0, cancelled->tcon, cancelled->fid.persistent_fid,
-		   cancelled->fid.volatile_fid);
-	cifs_put_tcon(cancelled->tcon);
+	rc = SMB2_close(0, tcon, cancelled->fid.persistent_fid,
+			cancelled->fid.volatile_fid);
+	if (rc)
+		cifs_tcon_dbg(VFS, "Close cancelled mid failed rc:%d\n", rc);
+
+	cifs_put_tcon(tcon);
 	kfree(cancelled);
 }
 
-/* Caller should already has an extra reference to @tcon */
+/*
+ * Caller should already has an extra reference to @tcon
+ * This function is used to queue work to close a handle to prevent leaks
+ * on the server.
+ * We handle two cases. If an open was interrupted after we sent the
+ * SMB2_CREATE to the server but before we processed the reply, and second
+ * if a close was interrupted before we sent the SMB2_CLOSE to the server.
+ */
 static int
-__smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
-			      __u64 volatile_fid)
+__smb2_handle_cancelled_cmd(struct cifs_tcon *tcon, __u16 cmd, __u64 mid,
+			    __u64 persistent_fid, __u64 volatile_fid)
 {
 	struct close_cancelled_open *cancelled;
 
@@ -752,6 +768,8 @@ __smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
 	cancelled->fid.persistent_fid = persistent_fid;
 	cancelled->fid.volatile_fid = volatile_fid;
 	cancelled->tcon = tcon;
+	cancelled->cmd = cmd;
+	cancelled->mid = mid;
 	INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
 	WARN_ON(queue_work(cifsiod_wq, &cancelled->work) == false);
 
@@ -769,7 +787,8 @@ smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
 	tcon->tc_count++;
 	spin_unlock(&cifs_tcp_ses_lock);
 
-	rc = __smb2_handle_cancelled_close(tcon, persistent_fid, volatile_fid);
+	rc = __smb2_handle_cancelled_cmd(tcon, SMB2_CLOSE_HE, 0,
+					 persistent_fid, volatile_fid);
 	if (rc)
 		cifs_put_tcon(tcon);
 
@@ -793,8 +812,11 @@ smb2_handle_cancelled_mid(char *buffer, struct TCP_Server_Info *server)
 	if (!tcon)
 		return -ENOENT;
 
-	rc = __smb2_handle_cancelled_close(tcon, rsp->PersistentFileId,
-					   rsp->VolatileFileId);
+	rc = __smb2_handle_cancelled_cmd(tcon,
+					 le16_to_cpu(sync_hdr->Command),
+					 le64_to_cpu(sync_hdr->MessageId),
+					 rsp->PersistentFileId,
+					 rsp->VolatileFileId);
 	if (rc)
 		cifs_put_tcon(tcon);
 
-- 
2.25.1