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#include "block/block.h"
31
32/**
33 * BlockJobDriver:
34 *
35 * A class type for block job driver.
36 */
37struct BlockJobDriver {
38 /** Generic JobDriver callbacks and settings */
39 JobDriver job_driver;
40
41 /*
42 * Returns whether the job has pending requests for the child or will
43 * submit new requests before the next pause point. This callback is polled
44 * in the context of draining a job node after requesting that the job be
45 * paused, until all activity on the child has stopped.
46 */
47 bool (*drained_poll)(BlockJob *job);
48
49 /*
50 * If the callback is not NULL, it will be invoked before the job is
51 * resumed in a new AioContext. This is the place to move any resources
52 * besides job->blk to the new AioContext.
53 */
54 void (*attached_aio_context)(BlockJob *job, AioContext *new_context);
55
56 /*
57 * If the callback is not NULL, it will be invoked when the job has to be
58 * synchronously cancelled or completed; it should drain BlockDriverStates
59 * as required to ensure progress.
60 *
61 * Block jobs must use the default implementation for job_driver.drain,
62 * which will in turn call this callback after doing generic block job
63 * stuff.
64 */
65 void (*drain)(BlockJob *job);
66};
67
68/**
69 * block_job_create:
70 * @job_id: The id of the newly-created job, or %NULL to have one
71 * generated automatically.
72 * @driver: The class object for the newly-created job.
73 * @txn: The transaction this job belongs to, if any. %NULL otherwise.
74 * @bs: The block
75 * @perm, @shared_perm: Permissions to request for @bs
76 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
77 * @flags: Creation flags for the Block Job. See @JobCreateFlags.
78 * @cb: Completion function for the job.
79 * @opaque: Opaque pointer value passed to @cb.
80 * @errp: Error object.
81 *
82 * Create a new long-running block device job and return it. The job
83 * will call @cb asynchronously when the job completes. Note that
84 * @bs may have been closed at the time the @cb it is called. If
85 * this is the case, the job may be reported as either cancelled or
86 * completed.
87 *
88 * This function is not part of the public job interface; it should be
89 * called from a wrapper that is specific to the job type.
90 */
91void *block_job_create(const char *job_id, const BlockJobDriver *driver,
92 JobTxn *txn, BlockDriverState *bs, uint64_t perm,
93 uint64_t shared_perm, int64_t speed, int flags,
94 BlockCompletionFunc *cb, void *opaque, Error **errp);
95
96/**
97 * block_job_free:
98 * Callback to be used for JobDriver.free in all block jobs. Frees block job
99 * specific resources in @job.
100 */
101void block_job_free(Job *job);
102
103/**
104 * block_job_user_resume:
105 * Callback to be used for JobDriver.user_resume in all block jobs. Resets the
106 * iostatus when the user resumes @job.
107 */
108void block_job_user_resume(Job *job);
109
110/**
111 * block_job_drain:
112 * Callback to be used for JobDriver.drain in all block jobs. Drains the main
113 * block node associated with the block jobs and calls BlockJobDriver.drain for
114 * job-specific actions.
115 */
116void block_job_drain(Job *job);
117
118/**
119 * block_job_ratelimit_get_delay:
120 *
121 * Calculate and return delay for the next request in ns. See the documentation
122 * of ratelimit_calculate_delay() for details.
123 */
124int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n);
125
126/**
127 * block_job_error_action:
128 * @job: The job to signal an error for.
129 * @on_err: The error action setting.
130 * @is_read: Whether the operation was a read.
131 * @error: The error that was reported.
132 *
133 * Report an I/O error for a block job and possibly stop the VM. Return the
134 * action that was selected based on @on_err and @error.
135 */
136BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
137 int is_read, int error);
138
139#endif
140