include/block/blockjob.h

   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 /**
  96  * block_job_get:
  97  * @id: The id of the block job.
  98  *
  99  * Get the block job identified by @id (which must not be %NULL).
 100  *
 101  * Returns the requested job, or %NULL if it doesn't exist.
 102  */
 103 BlockJob *block_job_get(const char *id);
 104
 105 /**
 106  * block_job_add_bdrv:
 107  * @job: A block job
 108  * @name: The name to assign to the new BdrvChild
 109  * @bs: A BlockDriverState that is involved in @job
 110  * @perm, @shared_perm: Permissions to request on the node
 111  *
 112  * Add @bs to the list of BlockDriverState that are involved in
 113  * @job. This means that all operations will be blocked on @bs while
 114  * @job exists.
 115  */
 116 int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
 117                        uint64_t perm, uint64_t shared_perm, Error **errp);
 118
 119 /**
 120  * block_job_remove_all_bdrv:
 121  * @job: The block job
 122  *
 123  * Remove all BlockDriverStates from the list of nodes that are involved in the
 124  * job. This removes the blockers added with block_job_add_bdrv().
 125  */
 126 void block_job_remove_all_bdrv(BlockJob *job);
 127
 128 /**
 129  * block_job_has_bdrv:
 130  * @job: The block job
 131  *
 132  * Searches for @bs in the list of nodes that are involved in the
 133  * job.
 134  */
 135 bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs);
 136
 137 /**
 138  * block_job_set_speed:
 139  * @job: The job to set the speed for.
 140  * @speed: The new value
 141  * @errp: Error object.
 142  *
 143  * Set a rate-limiting parameter for the job; the actual meaning may
 144  * vary depending on the job type.
 145  */
 146 bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp);
 147
 148 /**
 149  * block_job_query:
 150  * @job: The job to get information about.
 151  *
 152  * Return information about a job.
 153  */
 154 BlockJobInfo *block_job_query(BlockJob *job, Error **errp);
 155
 156 /**
 157  * block_job_iostatus_reset:
 158  * @job: The job whose I/O status should be reset.
 159  *
 160  * Reset I/O status on @job and on BlockDriverState objects it uses,
 161  * other than job->blk.
 162  */
 163 void block_job_iostatus_reset(BlockJob *job);
 164
 165 /*
 166  * block_job_get_aio_context:
 167  *
 168  * Returns aio context associated with a block job.
 169  */
 170 AioContext *block_job_get_aio_context(BlockJob *job);
 171
 172
 173 /*
 174  * Common functions that are neither I/O nor Global State.
 175  *
 176  * See include/block/block-common.h for more information about
 177  * the Common API.
 178  */
 179
 180 /**
 181  * block_job_is_internal:
 182  * @job: The job to determine if it is user-visible or not.
 183  *
 184  * Returns true if the job should not be visible to the management layer.
 185  */
 186 bool block_job_is_internal(BlockJob *job);
 187
 188 /**
 189  * block_job_driver:
 190  *
 191  * Returns the driver associated with a block job.
 192  */
 193 const BlockJobDriver *block_job_driver(BlockJob *job);
 194
 195 #endif