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1 | /* |
2 | * Declarations for long-running block device operations | |
3 | * | |
4 | * Copyright (c) 2011 IBM Corp. | |
5 | * Copyright (c) 2012 Red Hat, Inc. | |
6 | * | |
7 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
8 | * of this software and associated documentation files (the "Software"), to deal | |
9 | * in the Software without restriction, including without limitation the rights | |
10 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
11 | * copies of the Software, and to permit persons to whom the Software is | |
12 | * furnished to do so, subject to the following conditions: | |
13 | * | |
14 | * The above copyright notice and this permission notice shall be included in | |
15 | * all copies or substantial portions of the Software. | |
16 | * | |
17 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
18 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
19 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
20 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
21 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
22 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
23 | * THE SOFTWARE. | |
24 | */ | |
25 | #ifndef BLOCKJOB_H | |
26 | #define BLOCKJOB_H 1 | |
27 | ||
28 | #include "block.h" | |
29 | ||
30 | /** | |
31 | * BlockJobType: | |
32 | * | |
33 | * A class type for block job objects. | |
34 | */ | |
35 | typedef struct BlockJobType { | |
36 | /** Derived BlockJob struct size */ | |
37 | size_t instance_size; | |
38 | ||
39 | /** String describing the operation, part of query-block-jobs QMP API */ | |
40 | const char *job_type; | |
41 | ||
42 | /** Optional callback for job types that support setting a speed limit */ | |
43 | void (*set_speed)(BlockJob *job, int64_t speed, Error **errp); | |
44 | } BlockJobType; | |
45 | ||
46 | /** | |
47 | * BlockJob: | |
48 | * | |
49 | * Long-running operation on a BlockDriverState. | |
50 | */ | |
51 | struct BlockJob { | |
52 | /** The job type, including the job vtable. */ | |
53 | const BlockJobType *job_type; | |
54 | ||
55 | /** The block device on which the job is operating. */ | |
56 | BlockDriverState *bs; | |
57 | ||
58 | /** | |
59 | * The coroutine that executes the job. If not NULL, it is | |
60 | * reentered when busy is false and the job is cancelled. | |
61 | */ | |
62 | Coroutine *co; | |
63 | ||
64 | /** | |
65 | * Set to true if the job should cancel itself. The flag must | |
66 | * always be tested just before toggling the busy flag from false | |
67 | * to true. After a job has been cancelled, it should only yield | |
68 | * if #qemu_aio_wait will ("sooner or later") reenter the coroutine. | |
69 | */ | |
70 | bool cancelled; | |
71 | ||
72 | /** | |
73 | * Set to false by the job while it is in a quiescent state, where | |
74 | * no I/O is pending and the job has yielded on any condition | |
75 | * that is not detected by #qemu_aio_wait, such as a timer. | |
76 | */ | |
77 | bool busy; | |
78 | ||
79 | /** Offset that is published by the query-block-jobs QMP API */ | |
80 | int64_t offset; | |
81 | ||
82 | /** Length that is published by the query-block-jobs QMP API */ | |
83 | int64_t len; | |
84 | ||
85 | /** Speed that was set with @block_job_set_speed. */ | |
86 | int64_t speed; | |
87 | ||
88 | /** The completion function that will be called when the job completes. */ | |
89 | BlockDriverCompletionFunc *cb; | |
90 | ||
91 | /** The opaque value that is passed to the completion function. */ | |
92 | void *opaque; | |
93 | }; | |
94 | ||
95 | /** | |
96 | * block_job_create: | |
97 | * @job_type: The class object for the newly-created job. | |
98 | * @bs: The block | |
99 | * @speed: The maximum speed, in bytes per second, or 0 for unlimited. | |
100 | * @cb: Completion function for the job. | |
101 | * @opaque: Opaque pointer value passed to @cb. | |
102 | * @errp: Error object. | |
103 | * | |
104 | * Create a new long-running block device job and return it. The job | |
105 | * will call @cb asynchronously when the job completes. Note that | |
106 | * @bs may have been closed at the time the @cb it is called. If | |
107 | * this is the case, the job may be reported as either cancelled or | |
108 | * completed. | |
109 | * | |
110 | * This function is not part of the public job interface; it should be | |
111 | * called from a wrapper that is specific to the job type. | |
112 | */ | |
113 | void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs, | |
114 | int64_t speed, BlockDriverCompletionFunc *cb, | |
115 | void *opaque, Error **errp); | |
116 | ||
117 | /** | |
118 | * block_job_sleep_ns: | |
119 | * @job: The job that calls the function. | |
120 | * @clock: The clock to sleep on. | |
121 | * @ns: How many nanoseconds to stop for. | |
122 | * | |
123 | * Put the job to sleep (assuming that it wasn't canceled) for @ns | |
124 | * nanoseconds. Canceling the job will interrupt the wait immediately. | |
125 | */ | |
126 | void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns); | |
127 | ||
128 | /** | |
129 | * block_job_complete: | |
130 | * @job: The job being completed. | |
131 | * @ret: The status code. | |
132 | * | |
133 | * Call the completion function that was registered at creation time, and | |
134 | * free @job. | |
135 | */ | |
136 | void block_job_complete(BlockJob *job, int ret); | |
137 | ||
138 | /** | |
139 | * block_job_set_speed: | |
140 | * @job: The job to set the speed for. | |
141 | * @speed: The new value | |
142 | * @errp: Error object. | |
143 | * | |
144 | * Set a rate-limiting parameter for the job; the actual meaning may | |
145 | * vary depending on the job type. | |
146 | */ | |
147 | void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp); | |
148 | ||
149 | /** | |
150 | * block_job_cancel: | |
151 | * @job: The job to be canceled. | |
152 | * | |
153 | * Asynchronously cancel the specified job. | |
154 | */ | |
155 | void block_job_cancel(BlockJob *job); | |
156 | ||
157 | /** | |
158 | * block_job_is_cancelled: | |
159 | * @job: The job being queried. | |
160 | * | |
161 | * Returns whether the job is scheduled for cancellation. | |
162 | */ | |
163 | bool block_job_is_cancelled(BlockJob *job); | |
164 | ||
165 | /** | |
166 | * block_job_cancel_sync: | |
167 | * @job: The job to be canceled. | |
168 | * | |
169 | * Synchronously cancel the job. The completion callback is called | |
170 | * before the function returns. The job may actually complete | |
171 | * instead of canceling itself; the circumstances under which this | |
172 | * happens depend on the kind of job that is active. | |
173 | * | |
174 | * Returns the return value from the job if the job actually completed | |
175 | * during the call, or -ECANCELED if it was canceled. | |
176 | */ | |
177 | int block_job_cancel_sync(BlockJob *job); | |
178 | ||
179 | #endif |