xref: /openbmc/qemu/include/block/blockjob.h (revision 880eeec6)
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_H
27 #define BLOCKJOB_H
28 
29 #include "qemu/job.h"
30 #include "block/block.h"
31 #include "qemu/ratelimit.h"
32 
33 #define BLOCK_JOB_SLICE_TIME 100000000ULL /* ns */
34 
35 typedef struct BlockJobDriver BlockJobDriver;
36 
37 /**
38  * BlockJob:
39  *
40  * Long-running operation on a BlockDriverState.
41  */
42 typedef struct BlockJob {
43     /** Data belonging to the generic Job infrastructure */
44     Job job;
45 
46     /** Status that is published by the query-block-jobs QMP API */
47     BlockDeviceIoStatus iostatus;
48 
49     /** Speed that was set with @block_job_set_speed.  */
50     int64_t speed;
51 
52     /** Rate limiting data structure for implementing @speed. */
53     RateLimit limit;
54 
55     /** Block other operations when block job is running */
56     Error *blocker;
57 
58     /** Called when a cancelled job is finalised. */
59     Notifier finalize_cancelled_notifier;
60 
61     /** Called when a successfully completed job is finalised. */
62     Notifier finalize_completed_notifier;
63 
64     /** Called when the job transitions to PENDING */
65     Notifier pending_notifier;
66 
67     /** Called when the job transitions to READY */
68     Notifier ready_notifier;
69 
70     /** Called when the job coroutine yields or terminates */
71     Notifier idle_notifier;
72 
73     /** BlockDriverStates that are involved in this block job */
74     GSList *nodes;
75 } BlockJob;
76 
77 /*
78  * Global state (GS) API. These functions run under the BQL.
79  *
80  * See include/block/block-global-state.h for more information about
81  * the GS API.
82  */
83 
84 /**
85  * block_job_next:
86  * @job: A block job, or %NULL.
87  *
88  * Get the next element from the list of block jobs after @job, or the
89  * first one if @job is %NULL.
90  *
91  * Returns the requested job, or %NULL if there are no more jobs left.
92  */
93 BlockJob *block_job_next(BlockJob *job);
94 
95 /* Same as block_job_next(), but called with job lock held. */
96 BlockJob *block_job_next_locked(BlockJob *job);
97 
98 /**
99  * block_job_get:
100  * @id: The id of the block job.
101  *
102  * Get the block job identified by @id (which must not be %NULL).
103  *
104  * Returns the requested job, or %NULL if it doesn't exist.
105  */
106 BlockJob *block_job_get(const char *id);
107 
108 /* Same as block_job_get(), but called with job lock held. */
109 BlockJob *block_job_get_locked(const char *id);
110 
111 /**
112  * block_job_add_bdrv:
113  * @job: A block job
114  * @name: The name to assign to the new BdrvChild
115  * @bs: A BlockDriverState that is involved in @job
116  * @perm, @shared_perm: Permissions to request on the node
117  *
118  * Add @bs to the list of BlockDriverState that are involved in
119  * @job. This means that all operations will be blocked on @bs while
120  * @job exists.
121  */
122 int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
123                        uint64_t perm, uint64_t shared_perm, Error **errp);
124 
125 /**
126  * block_job_remove_all_bdrv:
127  * @job: The block job
128  *
129  * Remove all BlockDriverStates from the list of nodes that are involved in the
130  * job. This removes the blockers added with block_job_add_bdrv().
131  */
132 void block_job_remove_all_bdrv(BlockJob *job);
133 
134 /**
135  * block_job_has_bdrv:
136  * @job: The block job
137  *
138  * Searches for @bs in the list of nodes that are involved in the
139  * job.
140  */
141 bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs);
142 
143 /**
144  * block_job_set_speed:
145  * @job: The job to set the speed for.
146  * @speed: The new value
147  * @errp: Error object.
148  *
149  * Set a rate-limiting parameter for the job; the actual meaning may
150  * vary depending on the job type.
151  */
152 bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp);
153 
154 /*
155  * Same as block_job_set_speed(), but called with job lock held.
156  * Might release the lock temporarily.
157  */
158 bool block_job_set_speed_locked(BlockJob *job, int64_t speed, Error **errp);
159 
160 /**
161  * block_job_query:
162  * @job: The job to get information about.
163  *
164  * Return information about a job.
165  */
166 BlockJobInfo *block_job_query(BlockJob *job, Error **errp);
167 
168 /* Same as block_job_query(), but called with job lock held. */
169 BlockJobInfo *block_job_query_locked(BlockJob *job, Error **errp);
170 
171 /**
172  * block_job_iostatus_reset:
173  * @job: The job whose I/O status should be reset.
174  *
175  * Reset I/O status on @job and on BlockDriverState objects it uses,
176  * other than job->blk.
177  */
178 void block_job_iostatus_reset(BlockJob *job);
179 
180 /* Same as block_job_iostatus_reset(), but called with job lock held. */
181 void block_job_iostatus_reset_locked(BlockJob *job);
182 
183 /*
184  * block_job_get_aio_context:
185  *
186  * Returns aio context associated with a block job.
187  */
188 AioContext *block_job_get_aio_context(BlockJob *job);
189 
190 
191 /*
192  * Common functions that are neither I/O nor Global State.
193  *
194  * See include/block/block-common.h for more information about
195  * the Common API.
196  */
197 
198 /**
199  * block_job_is_internal:
200  * @job: The job to determine if it is user-visible or not.
201  *
202  * Returns true if the job should not be visible to the management layer.
203  */
204 bool block_job_is_internal(BlockJob *job);
205 
206 /**
207  * block_job_driver:
208  *
209  * Returns the driver associated with a block job.
210  */
211 const BlockJobDriver *block_job_driver(BlockJob *job);
212 
213 #endif
214