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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
26 #ifndef BLOCKJOB_INT_H
27 #define BLOCKJOB_INT_H
28
29 #include "block/blockjob.h"
30
31 /**
32 * BlockJobDriver:
33 *
34 * A class type for block job driver.
35 */
36 struct BlockJobDriver {
37 /** Generic JobDriver callbacks and settings */
38 JobDriver job_driver;
39
40 /*
41 * I/O API functions. These functions are thread-safe.
42 *
43 * See include/block/block-io.h for more information about
44 * the I/O API.
45 */
46
47 /*
48 * Returns whether the job has pending requests for the child or will
49 * submit new requests before the next pause point. This callback is polled
50 * in the context of draining a job node after requesting that the job be
51 * paused, until all activity on the child has stopped.
52 */
53 bool (*drained_poll)(BlockJob *job);
54
55 /*
56 * Global state (GS) API. These functions run under the BQL.
57 *
58 * See include/block/block-global-state.h for more information about
59 * the GS API.
60 */
61
62 /*
63 * If the callback is not NULL, it will be invoked before the job is
64 * resumed in a new AioContext. This is the place to move any resources
65 * besides job->blk to the new AioContext.
66 */
67 void (*attached_aio_context)(BlockJob *job, AioContext *new_context);
68
69 void (*set_speed)(BlockJob *job, int64_t speed);
70
71 /*
72 * Change the @job's options according to @opts.
73 *
74 * Note that this can already be called before the job coroutine is running.
75 */
76 void (*change)(BlockJob *job, BlockJobChangeOptions *opts, Error **errp);
77
78 /*
79 * Query information specific to this kind of block job.
80 */
81 void (*query)(BlockJob *job, BlockJobInfo *info);
82 };
83
84 /*
85 * Global state (GS) API. These functions run under the BQL.
86 *
87 * See include/block/block-global-state.h for more information about
88 * the GS API.
89 */
90
91 /**
92 * block_job_create:
93 * @job_id: The id of the newly-created job, or %NULL to have one
94 * generated automatically.
95 * @driver: The class object for the newly-created job.
96 * @txn: The transaction this job belongs to, if any. %NULL otherwise.
97 * @bs: The block
98 * @perm, @shared_perm: Permissions to request for @bs
99 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
100 * @flags: Creation flags for the Block Job. See @JobCreateFlags.
101 * @cb: Completion function for the job.
102 * @opaque: Opaque pointer value passed to @cb.
103 * @errp: Error object.
104 *
105 * Create a new long-running block device job and return it. The job
106 * will call @cb asynchronously when the job completes. Note that
107 * @bs may have been closed at the time the @cb it is called. If
108 * this is the case, the job may be reported as either cancelled or
109 * completed.
110 *
111 * This function is not part of the public job interface; it should be
112 * called from a wrapper that is specific to the job type.
113 */
114 void * GRAPH_UNLOCKED
115 block_job_create(const char *job_id, const BlockJobDriver *driver,
116 JobTxn *txn, BlockDriverState *bs, uint64_t perm,
117 uint64_t shared_perm, int64_t speed, int flags,
118 BlockCompletionFunc *cb, void *opaque, Error **errp);
119
120 /**
121 * block_job_free:
122 * Callback to be used for JobDriver.free in all block jobs. Frees block job
123 * specific resources in @job.
124 */
125 void block_job_free(Job *job);
126
127 /**
128 * block_job_user_resume:
129 * Callback to be used for JobDriver.user_resume in all block jobs. Resets the
130 * iostatus when the user resumes @job.
131 */
132 void block_job_user_resume(Job *job);
133
134 /*
135 * I/O API functions. These functions are thread-safe.
136 *
137 * See include/block/block-io.h for more information about
138 * the I/O API.
139 */
140
141 /**
142 * block_job_ratelimit_processed_bytes:
143 *
144 * To be called after some work has been done. Adjusts the delay for the next
145 * request. See the documentation of ratelimit_calculate_delay() for details.
146 */
147 void block_job_ratelimit_processed_bytes(BlockJob *job, uint64_t n);
148
149 /**
150 * Put the job to sleep (assuming that it wasn't canceled) to throttle it to the
151 * right speed according to its rate limiting.
152 */
153 void block_job_ratelimit_sleep(BlockJob *job);
154
155 /**
156 * block_job_error_action:
157 * @job: The job to signal an error for.
158 * @on_err: The error action setting.
159 * @is_read: Whether the operation was a read.
160 * @error: The error that was reported.
161 *
162 * Report an I/O error for a block job and possibly stop the VM. Return the
163 * action that was selected based on @on_err and @error.
164 */
165 BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
166 int is_read, int error);
167
168 #endif