Commit 31b9028c authored by Namjae Jeon's avatar Namjae Jeon Committed by Steve French
Browse files

ksmbd: convert tree_conns_lock to rw_semaphore 



Converts tree_conns_lock to an rw_semaphore to allow sleeping while
the lock is held. Additionally, it simplifies the locking logic in
ksmbd_tree_conn_session_logoff() and introduces
__ksmbd_tree_conn_disconnect() to avoid redundant locking.

Signed-off-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 00806087

fs/smb/server/mgmt/tree_connect.c

+21 −12
Original line number Diff line number Diff line
@@ -80,8 +80,10 @@ ksmbd_tree_conn_connect(struct ksmbd_work *work, const char *share_name) 
	status.tree_conn = tree_conn;

	atomic_set(&tree_conn->refcount, 1);



	down_write(&sess->tree_conns_lock);

	ret = xa_err(xa_store(&sess->tree_conns, tree_conn->id, tree_conn,

			      KSMBD_DEFAULT_GFP));

	up_write(&sess->tree_conns_lock);

	if (ret) {

		status.ret = -ENOMEM;

		goto out_error;
@@ -105,15 +107,11 @@ void ksmbd_tree_connect_put(struct ksmbd_tree_connect *tcon) 
		kfree(tcon);

}



int ksmbd_tree_conn_disconnect(struct ksmbd_session *sess,

static int __ksmbd_tree_conn_disconnect(struct ksmbd_session *sess,

					struct ksmbd_tree_connect *tree_conn)

{

	int ret;



	write_lock(&sess->tree_conns_lock);

	xa_erase(&sess->tree_conns, tree_conn->id);

	write_unlock(&sess->tree_conns_lock);



	ret = ksmbd_ipc_tree_disconnect_request(sess->id, tree_conn->id);

	ksmbd_release_tree_conn_id(sess, tree_conn->id);

	ksmbd_share_config_put(tree_conn->share_conf);
@@ -123,12 +121,22 @@ int ksmbd_tree_conn_disconnect(struct ksmbd_session *sess, 
	return ret;

}



int ksmbd_tree_conn_disconnect(struct ksmbd_session *sess,

			       struct ksmbd_tree_connect *tree_conn)

{

	down_write(&sess->tree_conns_lock);

	xa_erase(&sess->tree_conns, tree_conn->id);

	up_write(&sess->tree_conns_lock);



	return __ksmbd_tree_conn_disconnect(sess, tree_conn);

}



struct ksmbd_tree_connect *ksmbd_tree_conn_lookup(struct ksmbd_session *sess,

						  unsigned int id)

{

	struct ksmbd_tree_connect *tcon;



	read_lock(&sess->tree_conns_lock);

	down_read(&sess->tree_conns_lock);

	tcon = xa_load(&sess->tree_conns, id);

	if (tcon) {

		if (tcon->t_state != TREE_CONNECTED)
@@ -136,7 +144,7 @@ struct ksmbd_tree_connect *ksmbd_tree_conn_lookup(struct ksmbd_session *sess, 
		else if (!atomic_inc_not_zero(&tcon->refcount))

			tcon = NULL;

	}

	read_unlock(&sess->tree_conns_lock);

	up_read(&sess->tree_conns_lock);



	return tcon;

}
@@ -150,18 +158,19 @@ int ksmbd_tree_conn_session_logoff(struct ksmbd_session *sess) 
	if (!sess)

		return -EINVAL;



	down_write(&sess->tree_conns_lock);

	xa_for_each(&sess->tree_conns, id, tc) {

		write_lock(&sess->tree_conns_lock);

		if (tc->t_state == TREE_DISCONNECTED) {

			write_unlock(&sess->tree_conns_lock);

			ret = -ENOENT;

			continue;

		}

		tc->t_state = TREE_DISCONNECTED;

		write_unlock(&sess->tree_conns_lock);



		ret |= ksmbd_tree_conn_disconnect(sess, tc);

		xa_erase(&sess->tree_conns, tc->id);

		ret |= __ksmbd_tree_conn_disconnect(sess, tc);

	}

	xa_destroy(&sess->tree_conns);

	up_write(&sess->tree_conns_lock);



	return ret;

}

fs/smb/server/mgmt/user_session.c

+3 −1
Original line number Diff line number Diff line
@@ -135,6 +135,7 @@ static int show_proc_session(struct seq_file *m, void *v) 
	seq_printf(m, "%-20s\t%d\n", "channels", i);



	i = 0;

	down_read(&sess->tree_conns_lock);

	xa_for_each(&sess->tree_conns, id, tree_conn) {

		share_conf = tree_conn->share_conf;

		seq_printf(m, "%-20s\t%s\t%8d", "share",
@@ -145,6 +146,7 @@ static int show_proc_session(struct seq_file *m, void *v) 
			seq_printf(m, " %s ", "disk");

		seq_putc(m, '\n');

	}

	up_read(&sess->tree_conns_lock);



	ksmbd_user_session_put(sess);

	return 0;
@@ -673,8 +675,8 @@ static struct ksmbd_session *__session_create(int protocol) 
	xa_init(&sess->ksmbd_chann_list);

	xa_init(&sess->rpc_handle_list);

	sess->sequence_number = 1;

	rwlock_init(&sess->tree_conns_lock);

	atomic_set(&sess->refcnt, 2);

	init_rwsem(&sess->tree_conns_lock);

	init_rwsem(&sess->rpc_lock);

	init_rwsem(&sess->chann_lock);

fs/smb/server/mgmt/user_session.h

+1 −1
Original line number Diff line number Diff line
@@ -60,7 +60,7 @@ struct ksmbd_session { 


	struct ksmbd_file_table		file_table;

	unsigned long			last_active;

	rwlock_t			tree_conns_lock;

	struct rw_semaphore		tree_conns_lock;



#ifdef CONFIG_PROC_FS

	struct proc_dir_entry		*proc_entry;

fs/smb/server/smb2pdu.c

+5 −5
Original line number Diff line number Diff line
@@ -2037,9 +2037,9 @@ int smb2_tree_connect(struct ksmbd_work *work) 
	if (conn->posix_ext_supported)

		status.tree_conn->posix_extensions = true;



	write_lock(&sess->tree_conns_lock);

	down_write(&sess->tree_conns_lock);

	status.tree_conn->t_state = TREE_CONNECTED;

	write_unlock(&sess->tree_conns_lock);

	up_write(&sess->tree_conns_lock);

	rsp->StructureSize = cpu_to_le16(16);

out_err1:

	if (server_conf.flags & KSMBD_GLOBAL_FLAG_DURABLE_HANDLE && share &&
@@ -2193,16 +2193,16 @@ int smb2_tree_disconnect(struct ksmbd_work *work) 


	ksmbd_close_tree_conn_fds(work);



	write_lock(&sess->tree_conns_lock);

	down_write(&sess->tree_conns_lock);

	if (tcon->t_state == TREE_DISCONNECTED) {

		write_unlock(&sess->tree_conns_lock);

		up_write(&sess->tree_conns_lock);

		rsp->hdr.Status = STATUS_NETWORK_NAME_DELETED;

		err = -ENOENT;

		goto err_out;

	}



	tcon->t_state = TREE_DISCONNECTED;

	write_unlock(&sess->tree_conns_lock);

	up_write(&sess->tree_conns_lock);



	err = ksmbd_tree_conn_disconnect(sess, tcon);

	if (err) {