Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "This ncludes various cifs/smb3 bug fixes, mostly for stable as well.

  In the next week I expect that Germano will have some reconnection
  fixes, and also I expect to have the remaining pieces of the snapshot
  enablement and SMB3 ACLs, but wanted to get this set of bug fixes in"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  cifs_get_root shouldn't use path with tree name
  Fix default behaviour for empty domains and add domainauto option
  cifs: use %16phN for formatting md5 sum
  cifs: Fix smbencrypt() to stop pointing a scatterlist at the stack
  CIFS: Fix a possible double locking of mutex during reconnect
  CIFS: Fix a possible memory corruption during reconnect
  CIFS: Fix a possible memory corruption in push locks
  CIFS: Fix missing nls unload in smb2_reconnect()
  CIFS: Decrease verbosity of ioctl call
  SMB3: parsing for new snapshot timestamp mount parm

1 files changed, 59 insertions, 28 deletions

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 5ca5ea4668a1..87457227812c 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -250,16 +250,19 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
 	}
 
 	cifs_mark_open_files_invalid(tcon);
+	if (tcon->use_persistent)
+		tcon->need_reopen_files = true;
 
 	rc = SMB2_tcon(0, tcon->ses, tcon->treeName, tcon, nls_codepage);
 	mutex_unlock(&tcon->ses->session_mutex);
 
-	if (tcon->use_persistent)
-		cifs_reopen_persistent_handles(tcon);
-
 	cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
 	if (rc)
 		goto out;
+
+	if (smb2_command != SMB2_INTERNAL_CMD)
+		queue_delayed_work(cifsiod_wq, &server->reconnect, 0);
+
 	atomic_inc(&tconInfoReconnectCount);
 out:
 	/*
@@ -280,7 +283,7 @@ out:
 	case SMB2_CHANGE_NOTIFY:
 	case SMB2_QUERY_INFO:
 	case SMB2_SET_INFO:
-		return -EAGAIN;
+		rc = -EAGAIN;
 	}
 	unload_nls(nls_codepage);
 	return rc;
@@ -1972,6 +1975,55 @@ smb2_echo_callback(struct mid_q_entry *mid)
 	add_credits(server, credits_received, CIFS_ECHO_OP);
 }
 
+void smb2_reconnect_server(struct work_struct *work)
+{
+	struct TCP_Server_Info *server = container_of(work,
+					struct TCP_Server_Info, reconnect.work);
+	struct cifs_ses *ses;
+	struct cifs_tcon *tcon, *tcon2;
+	struct list_head tmp_list;
+	int tcon_exist = false;
+
+	/* Prevent simultaneous reconnects that can corrupt tcon->rlist list */
+	mutex_lock(&server->reconnect_mutex);
+
+	INIT_LIST_HEAD(&tmp_list);
+	cifs_dbg(FYI, "Need negotiate, reconnecting tcons\n");
+
+	spin_lock(&cifs_tcp_ses_lock);
+	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
+		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
+			if (tcon->need_reconnect || tcon->need_reopen_files) {
+				tcon->tc_count++;
+				list_add_tail(&tcon->rlist, &tmp_list);
+				tcon_exist = true;
+			}
+		}
+	}
+	/*
+	 * Get the reference to server struct to be sure that the last call of
+	 * cifs_put_tcon() in the loop below won't release the server pointer.
+	 */
+	if (tcon_exist)
+		server->srv_count++;
+
+	spin_unlock(&cifs_tcp_ses_lock);
+
+	list_for_each_entry_safe(tcon, tcon2, &tmp_list, rlist) {
+		if (!smb2_reconnect(SMB2_INTERNAL_CMD, tcon))
+			cifs_reopen_persistent_handles(tcon);
+		list_del_init(&tcon->rlist);
+		cifs_put_tcon(tcon);
+	}
+
+	cifs_dbg(FYI, "Reconnecting tcons finished\n");
+	mutex_unlock(&server->reconnect_mutex);
+
+	/* now we can safely release srv struct */
+	if (tcon_exist)
+		cifs_put_tcp_session(server, 1);
+}
+
 int
 SMB2_echo(struct TCP_Server_Info *server)
 {
@@ -1984,32 +2036,11 @@ SMB2_echo(struct TCP_Server_Info *server)
 	cifs_dbg(FYI, "In echo request\n");
 
 	if (server->tcpStatus == CifsNeedNegotiate) {
-		struct list_head *tmp, *tmp2;
-		struct cifs_ses *ses;
-		struct cifs_tcon *tcon;
-
-		cifs_dbg(FYI, "Need negotiate, reconnecting tcons\n");
-		spin_lock(&cifs_tcp_ses_lock);
-		list_for_each(tmp, &server->smb_ses_list) {
-			ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
-			list_for_each(tmp2, &ses->tcon_list) {
-				tcon = list_entry(tmp2, struct cifs_tcon,
-						  tcon_list);
-				/* add check for persistent handle reconnect */
-				if (tcon && tcon->need_reconnect) {
-					spin_unlock(&cifs_tcp_ses_lock);
-					rc = smb2_reconnect(SMB2_ECHO, tcon);
-					spin_lock(&cifs_tcp_ses_lock);
-				}
-			}
-		}
-		spin_unlock(&cifs_tcp_ses_lock);
+		/* No need to send echo on newly established connections */
+		queue_delayed_work(cifsiod_wq, &server->reconnect, 0);
+		return rc;
 	}
 
-	/* if no session, renegotiate failed above */
-	if (server->tcpStatus == CifsNeedNegotiate)
-		return -EIO;
-
 	rc = small_smb2_init(SMB2_ECHO, NULL, (void **)&req);
 	if (rc)
 		return rc;