1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
/*
* Copyright (C) 2003-2014 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_NFS_CONNECTION_HXX
#define MPD_NFS_CONNECTION_HXX
#include "Lease.hxx"
#include "Cancellable.hxx"
#include "event/SocketMonitor.hxx"
#include "event/DeferredMonitor.hxx"
#include "util/Error.hxx"
#include <boost/intrusive/list.hpp>
#include <string>
#include <list>
#include <forward_list>
struct nfs_context;
struct nfsdir;
struct nfsdirent;
class NfsCallback;
/**
* An asynchronous connection to a NFS server.
*/
class NfsConnection : SocketMonitor, DeferredMonitor {
class CancellableCallback : public CancellablePointer<NfsCallback> {
NfsConnection &connection;
/**
* Is this a nfs_open_async() operation? If yes, then
* we need to call nfs_close_async() on the new file
* handle as soon as the callback is invoked
* successfully.
*/
const bool open;
/**
* The file handle scheduled to be closed as soon as
* the operation finishes.
*/
struct nfsfh *close_fh;
public:
explicit CancellableCallback(NfsCallback &_callback,
NfsConnection &_connection,
bool _open)
:CancellablePointer<NfsCallback>(_callback),
connection(_connection),
open(_open), close_fh(nullptr) {}
bool Stat(nfs_context *context, const char *path,
Error &error);
bool OpenDirectory(nfs_context *context, const char *path,
Error &error);
bool Open(nfs_context *context, const char *path, int flags,
Error &error);
bool Stat(nfs_context *context, struct nfsfh *fh,
Error &error);
bool Read(nfs_context *context, struct nfsfh *fh,
uint64_t offset, size_t size,
Error &error);
/**
* Cancel the operation and schedule a call to
* nfs_close_async() with the given file handle.
*/
void CancelAndScheduleClose(struct nfsfh *fh);
private:
static void Callback(int err, struct nfs_context *nfs,
void *data, void *private_data);
void Callback(int err, void *data);
};
std::string server, export_name;
nfs_context *context;
typedef std::list<NfsLease *> LeaseList;
LeaseList new_leases, active_leases;
typedef CancellableList<NfsCallback, CancellableCallback> CallbackList;
CallbackList callbacks;
/**
* A list of NFS file handles (struct nfsfh *) which shall be
* closed as soon as nfs_service() returns. If we close the
* file handle while in nfs_service(), libnfs may crash, and
* deferring this call to after nfs_service() avoids this
* problem.
*/
std::forward_list<struct nfsfh *> deferred_close;
Error postponed_mount_error;
#ifndef NDEBUG
/**
* True when nfs_service() is being called.
*/
bool in_service;
/**
* True when OnSocketReady() is being called. During that,
* event updates are omitted.
*/
bool in_event;
#endif
bool mount_finished;
public:
gcc_nonnull_all
NfsConnection(EventLoop &_loop,
const char *_server, const char *_export_name)
:SocketMonitor(_loop), DeferredMonitor(_loop),
server(_server), export_name(_export_name),
context(nullptr) {}
/**
* Must be run from EventLoop's thread.
*/
~NfsConnection();
gcc_pure
const char *GetServer() const {
return server.c_str();
}
gcc_pure
const char *GetExportName() const {
return export_name.c_str();
}
EventLoop &GetEventLoop() {
return SocketMonitor::GetEventLoop();
}
/**
* Ensure that the connection is established. The connection
* is kept up while at least one #NfsLease is registered.
*
* This method is thread-safe. However, #NfsLease's methods
* will be invoked from within the #EventLoop's thread.
*/
void AddLease(NfsLease &lease);
void RemoveLease(NfsLease &lease);
bool Stat(const char *path, NfsCallback &callback, Error &error);
bool OpenDirectory(const char *path, NfsCallback &callback,
Error &error);
const struct nfsdirent *ReadDirectory(struct nfsdir *dir);
void CloseDirectory(struct nfsdir *dir);
bool Open(const char *path, int flags, NfsCallback &callback,
Error &error);
bool Stat(struct nfsfh *fh, NfsCallback &callback, Error &error);
bool Read(struct nfsfh *fh, uint64_t offset, size_t size,
NfsCallback &callback, Error &error);
void Cancel(NfsCallback &callback);
void Close(struct nfsfh *fh);
void CancelAndClose(struct nfsfh *fh, NfsCallback &callback);
protected:
virtual void OnNfsConnectionError(Error &&error) = 0;
private:
void DestroyContext();
/**
* Wrapper for nfs_close_async().
*/
void InternalClose(struct nfsfh *fh);
/**
* Invoke nfs_close_async() after nfs_service() returns.
*/
void DeferClose(struct nfsfh *fh);
bool MountInternal(Error &error);
void BroadcastMountSuccess();
void BroadcastMountError(Error &&error);
void BroadcastError(Error &&error);
static void MountCallback(int status, nfs_context *nfs, void *data,
void *private_data);
void MountCallback(int status, nfs_context *nfs, void *data);
void ScheduleSocket();
/**
* Wrapper for nfs_service().
*/
int Service(unsigned flags);
/* virtual methods from SocketMonitor */
virtual bool OnSocketReady(unsigned flags) override;
/* virtual methods from DeferredMonitor */
virtual void RunDeferred() override;
};
#endif
|
