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 "qapi/qapi-types-block-core.h"
  30 #include "qemu/job.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     /**
  44      * Data belonging to the generic Job infrastructure.
  45      * Protected by job mutex.
  46      */
  47     Job job;
  48
  49     /**
  50      * Status that is published by the query-block-jobs QMP API.
  51      * Protected by job mutex.
  52      */
  53     BlockDeviceIoStatus iostatus;
  54
  55     /**
  56      * Speed that was set with @block_job_set_speed.
  57      * Always modified and read under QEMU global mutex (GLOBAL_STATE_CODE).
  58      */
  59     int64_t speed;
  60
  61     /**
  62      * Rate limiting data structure for implementing @speed.
  63      * RateLimit API is thread-safe.
  64      */
  65     RateLimit limit;
  66
  67     /**
  68      * Block other operations when block job is running.
  69      * Always modified and read under QEMU global mutex (GLOBAL_STATE_CODE).
  70      */
  71     Error *blocker;
  72
  73     /** All notifiers are set once in block_job_create() and never modified. */
  74
  75     /** Called when a cancelled job is finalised. */
  76     Notifier finalize_cancelled_notifier;
  77
  78     /** Called when a successfully completed job is finalised. */
  79     Notifier finalize_completed_notifier;
  80
  81     /** Called when the job transitions to PENDING */
  82     Notifier pending_notifier;
  83
  84     /** Called when the job transitions to READY */
  85     Notifier ready_notifier;
  86
  87     /** Called when the job coroutine yields or terminates */
  88     Notifier idle_notifier;
  89
  90     /**
  91      * BlockDriverStates that are involved in this block job.
  92      * Always modified and read under QEMU global mutex (GLOBAL_STATE_CODE).
  93      */
  94     GSList *nodes;
  95 } BlockJob;
  96
  97 /*
  98  * Global state (GS) API. These functions run under the BQL.
  99  *
 100  * See include/block/block-global-state.h for more information about
 101  * the GS API.
 102  */
 103
 104 /**
 105  * block_job_next_locked:
 106  * @job: A block job, or %NULL.
 107  *
 108  * Get the next element from the list of block jobs after @job, or the
 109  * first one if @job is %NULL.
 110  *
 111  * Returns the requested job, or %NULL if there are no more jobs left.
 112  * Called with job lock held.
 113  */
 114 BlockJob *block_job_next_locked(BlockJob *job);
 115
 116 /**
 117  * block_job_get:
 118  * @id: The id of the block job.
 119  *
 120  * Get the block job identified by @id (which must not be %NULL).
 121  *
 122  * Returns the requested job, or %NULL if it doesn't exist.
 123  * Called with job lock *not* held.
 124  */
 125 BlockJob *block_job_get(const char *id);
 126
 127 /* Same as block_job_get(), but called with job lock held. */
 128 BlockJob *block_job_get_locked(const char *id);
 129
 130 /**
 131  * block_job_add_bdrv:
 132  * @job: A block job
 133  * @name: The name to assign to the new BdrvChild
 134  * @bs: A BlockDriverState that is involved in @job
 135  * @perm, @shared_perm: Permissions to request on the node
 136  *
 137  * Add @bs to the list of BlockDriverState that are involved in
 138  * @job. This means that all operations will be blocked on @bs while
 139  * @job exists.
 140  */
 141 int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
 142                        uint64_t perm, uint64_t shared_perm, Error **errp);
 143
 144 /**
 145  * block_job_remove_all_bdrv:
 146  * @job: The block job
 147  *
 148  * Remove all BlockDriverStates from the list of nodes that are involved in the
 149  * job. This removes the blockers added with block_job_add_bdrv().
 150  */
 151 void block_job_remove_all_bdrv(BlockJob *job);
 152
 153 /**
 154  * block_job_has_bdrv:
 155  * @job: The block job
 156  *
 157  * Searches for @bs in the list of nodes that are involved in the
 158  * job.
 159  */
 160 bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs);
 161
 162 /**
 163  * block_job_set_speed_locked:
 164  * @job: The job to set the speed for.
 165  * @speed: The new value
 166  * @errp: Error object.
 167  *
 168  * Set a rate-limiting parameter for the job; the actual meaning may
 169  * vary depending on the job type.
 170  *
 171  * Called with job lock held, but might release it temporarily.
 172  */
 173 bool block_job_set_speed_locked(BlockJob *job, int64_t speed, Error **errp);
 174
 175 /**
 176  * block_job_query_locked:
 177  * @job: The job to get information about.
 178  *
 179  * Return information about a job.
 180  *
 181  * Called with job lock held.
 182  */
 183 BlockJobInfo *block_job_query_locked(BlockJob *job, Error **errp);
 184
 185 /**
 186  * block_job_iostatus_reset_locked:
 187  * @job: The job whose I/O status should be reset.
 188  *
 189  * Reset I/O status on @job and on BlockDriverState objects it uses,
 190  * other than job->blk.
 191  *
 192  * Called with job lock held.
 193  */
 194 void block_job_iostatus_reset_locked(BlockJob *job);
 195
 196 /*
 197  * block_job_get_aio_context:
 198  *
 199  * Returns aio context associated with a block job.
 200  */
 201 AioContext *block_job_get_aio_context(BlockJob *job);
 202
 203
 204 /*
 205  * Common functions that are neither I/O nor Global State.
 206  *
 207  * See include/block/block-common.h for more information about
 208  * the Common API.
 209  */
 210
 211 /**
 212  * block_job_is_internal:
 213  * @job: The job to determine if it is user-visible or not.
 214  *
 215  * Returns true if the job should not be visible to the management layer.
 216  */
 217 bool block_job_is_internal(BlockJob *job);
 218
 219 /**
 220  * block_job_driver:
 221  *
 222  * Returns the driver associated with a block job.
 223  */
 224 const BlockJobDriver *block_job_driver(BlockJob *job);
 225
 226 #endif