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 typedef struct BlockJobTxn BlockJobTxn;
  37
  38 /**
  39  * BlockJob:
  40  *
  41  * Long-running operation on a BlockDriverState.
  42  */
  43 typedef struct BlockJob {
  44     /** Data belonging to the generic Job infrastructure */
  45     Job job;
  46
  47     /** The job type, including the job vtable.  */
  48     const BlockJobDriver *driver;
  49
  50     /** The block device on which the job is operating.  */
  51     BlockBackend *blk;
  52
  53     /**
  54      * Set to true if the job should abort immediately without waiting
  55      * for data to be in sync.
  56      */
  57     bool force;
  58
  59     /**
  60      * Set to true when the job is ready to be completed.
  61      */
  62     bool ready;
  63
  64     /** Status that is published by the query-block-jobs QMP API */
  65     BlockDeviceIoStatus iostatus;
  66
  67     /** Offset that is published by the query-block-jobs QMP API */
  68     int64_t offset;
  69
  70     /** Length that is published by the query-block-jobs QMP API */
  71     int64_t len;
  72
  73     /** Speed that was set with @block_job_set_speed.  */
  74     int64_t speed;
  75
  76     /** Rate limiting data structure for implementing @speed. */
  77     RateLimit limit;
  78
  79     /** Block other operations when block job is running */
  80     Error *blocker;
  81
  82     /** Called when a cancelled job is finalised. */
  83     Notifier finalize_cancelled_notifier;
  84
  85     /** Called when a successfully completed job is finalised. */
  86     Notifier finalize_completed_notifier;
  87
  88     /** Called when the job transitions to PENDING */
  89     Notifier pending_notifier;
  90
  91     /** BlockDriverStates that are involved in this block job */
  92     GSList *nodes;
  93
  94     BlockJobTxn *txn;
  95     QLIST_ENTRY(BlockJob) txn_list;
  96 } BlockJob;
  97
  98 /**
  99  * block_job_next:
 100  * @job: A block job, or %NULL.
 101  *
 102  * Get the next element from the list of block jobs after @job, or the
 103  * first one if @job is %NULL.
 104  *
 105  * Returns the requested job, or %NULL if there are no more jobs left.
 106  */
 107 BlockJob *block_job_next(BlockJob *job);
 108
 109 /**
 110  * block_job_get:
 111  * @id: The id of the block job.
 112  *
 113  * Get the block job identified by @id (which must not be %NULL).
 114  *
 115  * Returns the requested job, or %NULL if it doesn't exist.
 116  */
 117 BlockJob *block_job_get(const char *id);
 118
 119 /**
 120  * block_job_add_bdrv:
 121  * @job: A block job
 122  * @name: The name to assign to the new BdrvChild
 123  * @bs: A BlockDriverState that is involved in @job
 124  * @perm, @shared_perm: Permissions to request on the node
 125  *
 126  * Add @bs to the list of BlockDriverState that are involved in
 127  * @job. This means that all operations will be blocked on @bs while
 128  * @job exists.
 129  */
 130 int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
 131                        uint64_t perm, uint64_t shared_perm, Error **errp);
 132
 133 /**
 134  * block_job_remove_all_bdrv:
 135  * @job: The block job
 136  *
 137  * Remove all BlockDriverStates from the list of nodes that are involved in the
 138  * job. This removes the blockers added with block_job_add_bdrv().
 139  */
 140 void block_job_remove_all_bdrv(BlockJob *job);
 141
 142 /**
 143  * block_job_set_speed:
 144  * @job: The job to set the speed for.
 145  * @speed: The new value
 146  * @errp: Error object.
 147  *
 148  * Set a rate-limiting parameter for the job; the actual meaning may
 149  * vary depending on the job type.
 150  */
 151 void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp);
 152
 153 /**
 154  * block_job_cancel:
 155  * @job: The job to be canceled.
 156  * @force: Quit a job without waiting for data to be in sync.
 157  *
 158  * Asynchronously cancel the specified job.
 159  */
 160 void block_job_cancel(BlockJob *job, bool force);
 161
 162 /**
 163  * block_job_complete:
 164  * @job: The job to be completed.
 165  * @errp: Error object.
 166  *
 167  * Asynchronously complete the specified job.
 168  */
 169 void block_job_complete(BlockJob *job, Error **errp);
 170
 171
 172 /**
 173  * block_job_finalize:
 174  * @job: The job to fully commit and finish.
 175  * @errp: Error object.
 176  *
 177  * For jobs that have finished their work and are pending
 178  * awaiting explicit acknowledgement to commit their work,
 179  * This will commit that work.
 180  *
 181  * FIXME: Make the below statement universally true:
 182  * For jobs that support the manual workflow mode, all graph
 183  * changes that occur as a result will occur after this command
 184  * and before a successful reply.
 185  */
 186 void block_job_finalize(BlockJob *job, Error **errp);
 187
 188 /**
 189  * block_job_dismiss:
 190  * @job: The job to be dismissed.
 191  * @errp: Error object.
 192  *
 193  * Remove a concluded job from the query list.
 194  */
 195 void block_job_dismiss(BlockJob **job, Error **errp);
 196
 197 /**
 198  * block_job_progress_update:
 199  * @job: The job that has made progress
 200  * @done: How much progress the job made
 201  *
 202  * Updates the progress counter of the job.
 203  */
 204 void block_job_progress_update(BlockJob *job, uint64_t done);
 205
 206 /**
 207  * block_job_progress_set_remaining:
 208  * @job: The job whose expected progress end value is set
 209  * @remaining: Expected end value of the progress counter of the job
 210  *
 211  * Sets the expected end value of the progress counter of a job so that a
 212  * completion percentage can be calculated when the progress is updated.
 213  */
 214 void block_job_progress_set_remaining(BlockJob *job, uint64_t remaining);
 215
 216 /**
 217  * block_job_query:
 218  * @job: The job to get information about.
 219  *
 220  * Return information about a job.
 221  */
 222 BlockJobInfo *block_job_query(BlockJob *job, Error **errp);
 223
 224 /**
 225  * block_job_user_cancel:
 226  * @job: The job to be cancelled.
 227  * @force: Quit a job without waiting for data to be in sync.
 228  *
 229  * Cancels the specified job, but may refuse to do so if the
 230  * operation isn't currently meaningful.
 231  */
 232 void block_job_user_cancel(BlockJob *job, bool force, Error **errp);
 233
 234 /**
 235  * block_job_cancel_sync:
 236  * @job: The job to be canceled.
 237  *
 238  * Synchronously cancel the job.  The completion callback is called
 239  * before the function returns.  The job may actually complete
 240  * instead of canceling itself; the circumstances under which this
 241  * happens depend on the kind of job that is active.
 242  *
 243  * Returns the return value from the job if the job actually completed
 244  * during the call, or -ECANCELED if it was canceled.
 245  */
 246 int block_job_cancel_sync(BlockJob *job);
 247
 248 /**
 249  * block_job_cancel_sync_all:
 250  *
 251  * Synchronously cancels all jobs using block_job_cancel_sync().
 252  */
 253 void block_job_cancel_sync_all(void);
 254
 255 /**
 256  * block_job_complete_sync:
 257  * @job: The job to be completed.
 258  * @errp: Error object which may be set by block_job_complete(); this is not
 259  *        necessarily set on every error, the job return value has to be
 260  *        checked as well.
 261  *
 262  * Synchronously complete the job.  The completion callback is called before the
 263  * function returns, unless it is NULL (which is permissible when using this
 264  * function).
 265  *
 266  * Returns the return value from the job.
 267  */
 268 int block_job_complete_sync(BlockJob *job, Error **errp);
 269
 270 /**
 271  * block_job_iostatus_reset:
 272  * @job: The job whose I/O status should be reset.
 273  *
 274  * Reset I/O status on @job and on BlockDriverState objects it uses,
 275  * other than job->blk.
 276  */
 277 void block_job_iostatus_reset(BlockJob *job);
 278
 279 /**
 280  * block_job_txn_new:
 281  *
 282  * Allocate and return a new block job transaction.  Jobs can be added to the
 283  * transaction using block_job_txn_add_job().
 284  *
 285  * The transaction is automatically freed when the last job completes or is
 286  * cancelled.
 287  *
 288  * All jobs in the transaction either complete successfully or fail/cancel as a
 289  * group.  Jobs wait for each other before completing.  Cancelling one job
 290  * cancels all jobs in the transaction.
 291  */
 292 BlockJobTxn *block_job_txn_new(void);
 293
 294 /**
 295  * block_job_txn_unref:
 296  *
 297  * Release a reference that was previously acquired with block_job_txn_add_job
 298  * or block_job_txn_new. If it's the last reference to the object, it will be
 299  * freed.
 300  */
 301 void block_job_txn_unref(BlockJobTxn *txn);
 302
 303 /**
 304  * block_job_txn_add_job:
 305  * @txn: The transaction (may be NULL)
 306  * @job: Job to add to the transaction
 307  *
 308  * Add @job to the transaction.  The @job must not already be in a transaction.
 309  * The caller must call either block_job_txn_unref() or block_job_completed()
 310  * to release the reference that is automatically grabbed here.
 311  */
 312 void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job);
 313
 314 /**
 315  * block_job_is_internal:
 316  * @job: The job to determine if it is user-visible or not.
 317  *
 318  * Returns true if the job should not be visible to the management layer.
 319  */
 320 bool block_job_is_internal(BlockJob *job);
 321
 322 /**
 323  * block_job_driver:
 324  *
 325  * Returns the driver associated with a block job.
 326  */
 327 const BlockJobDriver *block_job_driver(BlockJob *job);
 328
 329 #endif