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 | */ |
37 | struct 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 | */ |
91 | void *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 | */ |
101 | void 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 | */ |
108 | void 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 | */ |
116 | void 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 | */ |
124 | int64_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 | */ |
136 | BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err, |
137 | int is_read, int error); |
138 | |
139 | #endif |
140 | |