xref: /linux/fs/smb/server/mgmt/tree_connect.c (revision cdd30ebb1b9f36159d66f088b61aee264e649d7a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
4  */
5 
6 #include <linux/list.h>
7 #include <linux/slab.h>
8 #include <linux/xarray.h>
9 
10 #include "../transport_ipc.h"
11 #include "../connection.h"
12 
13 #include "tree_connect.h"
14 #include "user_config.h"
15 #include "share_config.h"
16 #include "user_session.h"
17 
18 struct ksmbd_tree_conn_status
19 ksmbd_tree_conn_connect(struct ksmbd_work *work, const char *share_name)
20 {
21 	struct ksmbd_tree_conn_status status = {-ENOENT, NULL};
22 	struct ksmbd_tree_connect_response *resp = NULL;
23 	struct ksmbd_share_config *sc;
24 	struct ksmbd_tree_connect *tree_conn = NULL;
25 	struct sockaddr *peer_addr;
26 	struct ksmbd_conn *conn = work->conn;
27 	struct ksmbd_session *sess = work->sess;
28 	int ret;
29 
30 	sc = ksmbd_share_config_get(work, share_name);
31 	if (!sc)
32 		return status;
33 
34 	tree_conn = kzalloc(sizeof(struct ksmbd_tree_connect),
35 			    KSMBD_DEFAULT_GFP);
36 	if (!tree_conn) {
37 		status.ret = -ENOMEM;
38 		goto out_error;
39 	}
40 
41 	tree_conn->id = ksmbd_acquire_tree_conn_id(sess);
42 	if (tree_conn->id < 0) {
43 		status.ret = -EINVAL;
44 		goto out_error;
45 	}
46 
47 	peer_addr = KSMBD_TCP_PEER_SOCKADDR(conn);
48 	resp = ksmbd_ipc_tree_connect_request(sess,
49 					      sc,
50 					      tree_conn,
51 					      peer_addr);
52 	if (!resp) {
53 		status.ret = -EINVAL;
54 		goto out_error;
55 	}
56 
57 	status.ret = resp->status;
58 	if (status.ret != KSMBD_TREE_CONN_STATUS_OK)
59 		goto out_error;
60 
61 	tree_conn->flags = resp->connection_flags;
62 	if (test_tree_conn_flag(tree_conn, KSMBD_TREE_CONN_FLAG_UPDATE)) {
63 		struct ksmbd_share_config *new_sc;
64 
65 		ksmbd_share_config_del(sc);
66 		new_sc = ksmbd_share_config_get(work, share_name);
67 		if (!new_sc) {
68 			pr_err("Failed to update stale share config\n");
69 			status.ret = -ESTALE;
70 			goto out_error;
71 		}
72 		ksmbd_share_config_put(sc);
73 		sc = new_sc;
74 	}
75 
76 	tree_conn->user = sess->user;
77 	tree_conn->share_conf = sc;
78 	tree_conn->t_state = TREE_NEW;
79 	status.tree_conn = tree_conn;
80 	atomic_set(&tree_conn->refcount, 1);
81 	init_waitqueue_head(&tree_conn->refcount_q);
82 
83 	ret = xa_err(xa_store(&sess->tree_conns, tree_conn->id, tree_conn,
84 			      KSMBD_DEFAULT_GFP));
85 	if (ret) {
86 		status.ret = -ENOMEM;
87 		goto out_error;
88 	}
89 	kvfree(resp);
90 	return status;
91 
92 out_error:
93 	if (tree_conn)
94 		ksmbd_release_tree_conn_id(sess, tree_conn->id);
95 	ksmbd_share_config_put(sc);
96 	kfree(tree_conn);
97 	kvfree(resp);
98 	return status;
99 }
100 
101 void ksmbd_tree_connect_put(struct ksmbd_tree_connect *tcon)
102 {
103 	/*
104 	 * Checking waitqueue to releasing tree connect on
105 	 * tree disconnect. waitqueue_active is safe because it
106 	 * uses atomic operation for condition.
107 	 */
108 	if (!atomic_dec_return(&tcon->refcount) &&
109 	    waitqueue_active(&tcon->refcount_q))
110 		wake_up(&tcon->refcount_q);
111 }
112 
113 int ksmbd_tree_conn_disconnect(struct ksmbd_session *sess,
114 			       struct ksmbd_tree_connect *tree_conn)
115 {
116 	int ret;
117 
118 	write_lock(&sess->tree_conns_lock);
119 	xa_erase(&sess->tree_conns, tree_conn->id);
120 	write_unlock(&sess->tree_conns_lock);
121 
122 	if (!atomic_dec_and_test(&tree_conn->refcount))
123 		wait_event(tree_conn->refcount_q,
124 			   atomic_read(&tree_conn->refcount) == 0);
125 
126 	ret = ksmbd_ipc_tree_disconnect_request(sess->id, tree_conn->id);
127 	ksmbd_release_tree_conn_id(sess, tree_conn->id);
128 	ksmbd_share_config_put(tree_conn->share_conf);
129 	kfree(tree_conn);
130 	return ret;
131 }
132 
133 struct ksmbd_tree_connect *ksmbd_tree_conn_lookup(struct ksmbd_session *sess,
134 						  unsigned int id)
135 {
136 	struct ksmbd_tree_connect *tcon;
137 
138 	read_lock(&sess->tree_conns_lock);
139 	tcon = xa_load(&sess->tree_conns, id);
140 	if (tcon) {
141 		if (tcon->t_state != TREE_CONNECTED)
142 			tcon = NULL;
143 		else if (!atomic_inc_not_zero(&tcon->refcount))
144 			tcon = NULL;
145 	}
146 	read_unlock(&sess->tree_conns_lock);
147 
148 	return tcon;
149 }
150 
151 int ksmbd_tree_conn_session_logoff(struct ksmbd_session *sess)
152 {
153 	int ret = 0;
154 	struct ksmbd_tree_connect *tc;
155 	unsigned long id;
156 
157 	if (!sess)
158 		return -EINVAL;
159 
160 	xa_for_each(&sess->tree_conns, id, tc) {
161 		write_lock(&sess->tree_conns_lock);
162 		if (tc->t_state == TREE_DISCONNECTED) {
163 			write_unlock(&sess->tree_conns_lock);
164 			ret = -ENOENT;
165 			continue;
166 		}
167 		tc->t_state = TREE_DISCONNECTED;
168 		write_unlock(&sess->tree_conns_lock);
169 
170 		ret |= ksmbd_tree_conn_disconnect(sess, tc);
171 	}
172 	xa_destroy(&sess->tree_conns);
173 	return ret;
174 }
175