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 #ifndef BLOCKJOB_H 26 #define BLOCKJOB_H 1 27 28 #include "block/block.h" 29 30 /** 31 * BlockJobType: 32 * 33 * A class type for block job objects. 34 */ 35 typedef struct BlockJobType { 36 /** Derived BlockJob struct size */ 37 size_t instance_size; 38 39 /** String describing the operation, part of query-block-jobs QMP API */ 40 const char *job_type; 41 42 /** Optional callback for job types that support setting a speed limit */ 43 void (*set_speed)(BlockJob *job, int64_t speed, Error **errp); 44 45 /** Optional callback for job types that need to forward I/O status reset */ 46 void (*iostatus_reset)(BlockJob *job); 47 48 /** 49 * Optional callback for job types whose completion must be triggered 50 * manually. 51 */ 52 void (*complete)(BlockJob *job, Error **errp); 53 } BlockJobType; 54 55 /** 56 * BlockJob: 57 * 58 * Long-running operation on a BlockDriverState. 59 */ 60 struct BlockJob { 61 /** The job type, including the job vtable. */ 62 const BlockJobType *job_type; 63 64 /** The block device on which the job is operating. */ 65 BlockDriverState *bs; 66 67 /** 68 * The coroutine that executes the job. If not NULL, it is 69 * reentered when busy is false and the job is cancelled. 70 */ 71 Coroutine *co; 72 73 /** 74 * Set to true if the job should cancel itself. The flag must 75 * always be tested just before toggling the busy flag from false 76 * to true. After a job has been cancelled, it should only yield 77 * if #qemu_aio_wait will ("sooner or later") reenter the coroutine. 78 */ 79 bool cancelled; 80 81 /** 82 * Set to true if the job is either paused, or will pause itself 83 * as soon as possible (if busy == true). 84 */ 85 bool paused; 86 87 /** 88 * Set to false by the job while it is in a quiescent state, where 89 * no I/O is pending and the job has yielded on any condition 90 * that is not detected by #qemu_aio_wait, such as a timer. 91 */ 92 bool busy; 93 94 /** Status that is published by the query-block-jobs QMP API */ 95 BlockDeviceIoStatus iostatus; 96 97 /** Offset that is published by the query-block-jobs QMP API */ 98 int64_t offset; 99 100 /** Length that is published by the query-block-jobs QMP API */ 101 int64_t len; 102 103 /** Speed that was set with @block_job_set_speed. */ 104 int64_t speed; 105 106 /** The completion function that will be called when the job completes. */ 107 BlockDriverCompletionFunc *cb; 108 109 /** The opaque value that is passed to the completion function. */ 110 void *opaque; 111 }; 112 113 /** 114 * block_job_create: 115 * @job_type: The class object for the newly-created job. 116 * @bs: The block 117 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 118 * @cb: Completion function for the job. 119 * @opaque: Opaque pointer value passed to @cb. 120 * @errp: Error object. 121 * 122 * Create a new long-running block device job and return it. The job 123 * will call @cb asynchronously when the job completes. Note that 124 * @bs may have been closed at the time the @cb it is called. If 125 * this is the case, the job may be reported as either cancelled or 126 * completed. 127 * 128 * This function is not part of the public job interface; it should be 129 * called from a wrapper that is specific to the job type. 130 */ 131 void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs, 132 int64_t speed, BlockDriverCompletionFunc *cb, 133 void *opaque, Error **errp); 134 135 /** 136 * block_job_sleep_ns: 137 * @job: The job that calls the function. 138 * @clock: The clock to sleep on. 139 * @ns: How many nanoseconds to stop for. 140 * 141 * Put the job to sleep (assuming that it wasn't canceled) for @ns 142 * nanoseconds. Canceling the job will interrupt the wait immediately. 143 */ 144 void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns); 145 146 /** 147 * block_job_completed: 148 * @job: The job being completed. 149 * @ret: The status code. 150 * 151 * Call the completion function that was registered at creation time, and 152 * free @job. 153 */ 154 void block_job_completed(BlockJob *job, int ret); 155 156 /** 157 * block_job_set_speed: 158 * @job: The job to set the speed for. 159 * @speed: The new value 160 * @errp: Error object. 161 * 162 * Set a rate-limiting parameter for the job; the actual meaning may 163 * vary depending on the job type. 164 */ 165 void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp); 166 167 /** 168 * block_job_cancel: 169 * @job: The job to be canceled. 170 * 171 * Asynchronously cancel the specified job. 172 */ 173 void block_job_cancel(BlockJob *job); 174 175 /** 176 * block_job_complete: 177 * @job: The job to be completed. 178 * @errp: Error object. 179 * 180 * Asynchronously complete the specified job. 181 */ 182 void block_job_complete(BlockJob *job, Error **errp); 183 184 /** 185 * block_job_is_cancelled: 186 * @job: The job being queried. 187 * 188 * Returns whether the job is scheduled for cancellation. 189 */ 190 bool block_job_is_cancelled(BlockJob *job); 191 192 /** 193 * block_job_query: 194 * @job: The job to get information about. 195 * 196 * Return information about a job. 197 */ 198 BlockJobInfo *block_job_query(BlockJob *job); 199 200 /** 201 * block_job_pause: 202 * @job: The job to be paused. 203 * 204 * Asynchronously pause the specified job. 205 */ 206 void block_job_pause(BlockJob *job); 207 208 /** 209 * block_job_resume: 210 * @job: The job to be resumed. 211 * 212 * Resume the specified job. 213 */ 214 void block_job_resume(BlockJob *job); 215 216 /** 217 * qobject_from_block_job: 218 * @job: The job whose information is requested. 219 * 220 * Return a QDict corresponding to @job's query-block-jobs entry. 221 */ 222 QObject *qobject_from_block_job(BlockJob *job); 223 224 /** 225 * block_job_ready: 226 * @job: The job which is now ready to complete. 227 * 228 * Send a BLOCK_JOB_READY event for the specified job. 229 */ 230 void block_job_ready(BlockJob *job); 231 232 /** 233 * block_job_is_paused: 234 * @job: The job being queried. 235 * 236 * Returns whether the job is currently paused, or will pause 237 * as soon as it reaches a sleeping point. 238 */ 239 bool block_job_is_paused(BlockJob *job); 240 241 /** 242 * block_job_cancel_sync: 243 * @job: The job to be canceled. 244 * 245 * Synchronously cancel the job. The completion callback is called 246 * before the function returns. The job may actually complete 247 * instead of canceling itself; the circumstances under which this 248 * happens depend on the kind of job that is active. 249 * 250 * Returns the return value from the job if the job actually completed 251 * during the call, or -ECANCELED if it was canceled. 252 */ 253 int block_job_cancel_sync(BlockJob *job); 254 255 /** 256 * block_job_iostatus_reset: 257 * @job: The job whose I/O status should be reset. 258 * 259 * Reset I/O status on @job and on BlockDriverState objects it uses, 260 * other than job->bs. 261 */ 262 void block_job_iostatus_reset(BlockJob *job); 263 264 /** 265 * block_job_error_action: 266 * @job: The job to signal an error for. 267 * @bs: The block device on which to set an I/O error. 268 * @on_err: The error action setting. 269 * @is_read: Whether the operation was a read. 270 * @error: The error that was reported. 271 * 272 * Report an I/O error for a block job and possibly stop the VM. Return the 273 * action that was selected based on @on_err and @error. 274 */ 275 BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs, 276 BlockdevOnError on_err, 277 int is_read, int error); 278 #endif 279