summaryrefslogtreecommitdiffstats
path: root/contrib/qemu/include/block/blockjob.h
blob: c290d07bba008c494b9987a4e872385f1932439a (plain)
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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
/*
 * Declarations for long-running block device operations
 *
 * Copyright (c) 2011 IBM Corp.
 * Copyright (c) 2012 Red Hat, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#ifndef BLOCKJOB_H
#define BLOCKJOB_H 1

#include "block/block.h"

/**
 * BlockJobType:
 *
 * A class type for block job objects.
 */
typedef struct BlockJobType {
    /** Derived BlockJob struct size */
    size_t instance_size;

    /** String describing the operation, part of query-block-jobs QMP API */
    const char *job_type;

    /** Optional callback for job types that support setting a speed limit */
    void (*set_speed)(BlockJob *job, int64_t speed, Error **errp);

    /** Optional callback for job types that need to forward I/O status reset */
    void (*iostatus_reset)(BlockJob *job);

    /**
     * Optional callback for job types whose completion must be triggered
     * manually.
     */
    void (*complete)(BlockJob *job, Error **errp);
} BlockJobType;

/**
 * BlockJob:
 *
 * Long-running operation on a BlockDriverState.
 */
struct BlockJob {
    /** The job type, including the job vtable.  */
    const BlockJobType *job_type;

    /** The block device on which the job is operating.  */
    BlockDriverState *bs;

    /**
     * The coroutine that executes the job.  If not NULL, it is
     * reentered when busy is false and the job is cancelled.
     */
    Coroutine *co;

    /**
     * Set to true if the job should cancel itself.  The flag must
     * always be tested just before toggling the busy flag from false
     * to true.  After a job has been cancelled, it should only yield
     * if #qemu_aio_wait will ("sooner or later") reenter the coroutine.
     */
    bool cancelled;

    /**
     * Set to true if the job is either paused, or will pause itself
     * as soon as possible (if busy == true).
     */
    bool paused;

    /**
     * Set to false by the job while it is in a quiescent state, where
     * no I/O is pending and the job has yielded on any condition
     * that is not detected by #qemu_aio_wait, such as a timer.
     */
    bool busy;

    /** Status that is published by the query-block-jobs QMP API */
    BlockDeviceIoStatus iostatus;

    /** Offset that is published by the query-block-jobs QMP API */
    int64_t offset;

    /** Length that is published by the query-block-jobs QMP API */
    int64_t len;

    /** Speed that was set with @block_job_set_speed.  */
    int64_t speed;

    /** The completion function that will be called when the job completes.  */
    BlockDriverCompletionFunc *cb;

    /** The opaque value that is passed to the completion function.  */
    void *opaque;
};

/**
 * block_job_create:
 * @job_type: The class object for the newly-created job.
 * @bs: The block
 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 * @cb: Completion function for the job.
 * @opaque: Opaque pointer value passed to @cb.
 * @errp: Error object.
 *
 * Create a new long-running block device job and return it.  The job
 * will call @cb asynchronously when the job completes.  Note that
 * @bs may have been closed at the time the @cb it is called.  If
 * this is the case, the job may be reported as either cancelled or
 * completed.
 *
 * This function is not part of the public job interface; it should be
 * called from a wrapper that is specific to the job type.
 */
void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs,
                       int64_t speed, BlockDriverCompletionFunc *cb,
                       void *opaque, Error **errp);

/**
 * block_job_sleep_ns:
 * @job: The job that calls the function.
 * @clock: The clock to sleep on.
 * @ns: How many nanoseconds to stop for.
 *
 * Put the job to sleep (assuming that it wasn't canceled) for @ns
 * nanoseconds.  Canceling the job will interrupt the wait immediately.
 */
void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns);

/**
 * block_job_completed:
 * @job: The job being completed.
 * @ret: The status code.
 *
 * Call the completion function that was registered at creation time, and
 * free @job.
 */
void block_job_completed(BlockJob *job, int ret);

/**
 * block_job_set_speed:
 * @job: The job to set the speed for.
 * @speed: The new value
 * @errp: Error object.
 *
 * Set a rate-limiting parameter for the job; the actual meaning may
 * vary depending on the job type.
 */
void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp);

/**
 * block_job_cancel:
 * @job: The job to be canceled.
 *
 * Asynchronously cancel the specified job.
 */
void block_job_cancel(BlockJob *job);

/**
 * block_job_complete:
 * @job: The job to be completed.
 * @errp: Error object.
 *
 * Asynchronously complete the specified job.
 */
void block_job_complete(BlockJob *job, Error **errp);

/**
 * block_job_is_cancelled:
 * @job: The job being queried.
 *
 * Returns whether the job is scheduled for cancellation.
 */
bool block_job_is_cancelled(BlockJob *job);

/**
 * block_job_query:
 * @job: The job to get information about.
 *
 * Return information about a job.
 */
BlockJobInfo *block_job_query(BlockJob *job);

/**
 * block_job_pause:
 * @job: The job to be paused.
 *
 * Asynchronously pause the specified job.
 */
void block_job_pause(BlockJob *job);

/**
 * block_job_resume:
 * @job: The job to be resumed.
 *
 * Resume the specified job.
 */
void block_job_resume(BlockJob *job);

/**
 * qobject_from_block_job:
 * @job: The job whose information is requested.
 *
 * Return a QDict corresponding to @job's query-block-jobs entry.
 */
QObject *qobject_from_block_job(BlockJob *job);

/**
 * block_job_ready:
 * @job: The job which is now ready to complete.
 *
 * Send a BLOCK_JOB_READY event for the specified job.
 */
void block_job_ready(BlockJob *job);

/**
 * block_job_is_paused:
 * @job: The job being queried.
 *
 * Returns whether the job is currently paused, or will pause
 * as soon as it reaches a sleeping point.
 */
bool block_job_is_paused(BlockJob *job);

/**
 * block_job_cancel_sync:
 * @job: The job to be canceled.
 *
 * Synchronously cancel the job.  The completion callback is called
 * before the function returns.  The job may actually complete
 * instead of canceling itself; the circumstances under which this
 * happens depend on the kind of job that is active.
 *
 * Returns the return value from the job if the job actually completed
 * during the call, or -ECANCELED if it was canceled.
 */
int block_job_cancel_sync(BlockJob *job);

/**
 * block_job_iostatus_reset:
 * @job: The job whose I/O status should be reset.
 *
 * Reset I/O status on @job and on BlockDriverState objects it uses,
 * other than job->bs.
 */
void block_job_iostatus_reset(BlockJob *job);

/**
 * block_job_error_action:
 * @job: The job to signal an error for.
 * @bs: The block device on which to set an I/O error.
 * @on_err: The error action setting.
 * @is_read: Whether the operation was a read.
 * @error: The error that was reported.
 *
 * Report an I/O error for a block job and possibly stop the VM.  Return the
 * action that was selected based on @on_err and @error.
 */
BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs,
                                        BlockdevOnError on_err,
                                        int is_read, int error);
#endif