72029fe85d
9p trans modules aren't refcounted nor were they unregistered properly. Fix it. * Add 9p_trans_module->owner and reference the module on each trans instance creation and put it on destruction. * Protect v9fs_trans_list with a spinlock. This isn't strictly necessary as the list is manipulated only during module loading / unloading but it's a good idea to make the API safe. * Unregister trans modules when the corresponding module is being unloaded. * While at it, kill unnecessary EXPORT_SYMBOL on p9_trans_fd_init(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
105 lines
3.4 KiB
C
105 lines
3.4 KiB
C
/*
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* include/net/9p/transport.h
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*
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* Transport Definition
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*
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* Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
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* Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to:
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* Free Software Foundation
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* 51 Franklin Street, Fifth Floor
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* Boston, MA 02111-1301 USA
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*
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*/
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#ifndef NET_9P_TRANSPORT_H
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#define NET_9P_TRANSPORT_H
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#include <linux/module.h>
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/**
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* enum p9_trans_status - different states of underlying transports
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* @Connected: transport is connected and healthy
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* @Disconnected: transport has been disconnected
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* @Hung: transport is connected by wedged
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*
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* This enumeration details the various states a transport
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* instatiation can be in.
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*/
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enum p9_trans_status {
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Connected,
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Disconnected,
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Hung,
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};
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/**
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* struct p9_trans - per-transport state and API
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* @status: transport &p9_trans_status
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* @msize: negotiated maximum packet size (duplicate from client)
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* @extended: negotiated protocol extensions (duplicate from client)
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* @priv: transport private data
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* @close: member function to disconnect and close the transport
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* @rpc: member function to issue a request to the transport
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*
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* This is the basic API for a transport instance. It is used as
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* a handle by the client to issue requests. This interface is currently
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* in flux during reorganization.
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*
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* Bugs: there is lots of duplicated data here and its not clear that
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* the member functions need to be per-instance versus per transport
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* module.
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*/
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struct p9_trans {
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enum p9_trans_status status;
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int msize;
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unsigned char extended;
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void *priv;
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void (*close) (struct p9_trans *);
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int (*rpc) (struct p9_trans *t, struct p9_fcall *tc,
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struct p9_fcall **rc);
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};
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/**
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* struct p9_trans_module - transport module interface
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* @list: used to maintain a list of currently available transports
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* @name: the human-readable name of the transport
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* @maxsize: transport provided maximum packet size
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* @def: set if this transport should be considered the default
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* @create: member function to create a new connection on this transport
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*
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* This is the basic API for a transport module which is registered by the
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* transport module with the 9P core network module and used by the client
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* to instantiate a new connection on a transport.
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*
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* Bugs: the transport module list isn't protected.
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*/
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struct p9_trans_module {
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struct list_head list;
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char *name; /* name of transport */
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int maxsize; /* max message size of transport */
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int def; /* this transport should be default */
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struct p9_trans * (*create)(const char *, char *, int, unsigned char);
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struct module *owner;
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};
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void v9fs_register_trans(struct p9_trans_module *m);
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void v9fs_unregister_trans(struct p9_trans_module *m);
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struct p9_trans_module *v9fs_get_trans_by_name(const substring_t *name);
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struct p9_trans_module *v9fs_get_default_trans(void);
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void v9fs_put_trans(struct p9_trans_module *m);
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#endif /* NET_9P_TRANSPORT_H */
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