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_INT_H 27 #define BLOCKJOB_INT_H 28 29 #include "block/blockjob.h" 30 #include "block/block.h" 31 32 /** 33 * BlockJobDriver: 34 * 35 * A class type for block job driver. 36 */ 37 struct BlockJobDriver { 38 /** Derived BlockJob struct size */ 39 size_t instance_size; 40 41 /** String describing the operation, part of query-block-jobs QMP API */ 42 BlockJobType job_type; 43 44 /** Optional callback for job types that support setting a speed limit */ 45 void (*set_speed)(BlockJob *job, int64_t speed, Error **errp); 46 47 /** Mandatory: Entrypoint for the Coroutine. */ 48 CoroutineEntry *start; 49 50 /** 51 * Optional callback for job types whose completion must be triggered 52 * manually. 53 */ 54 void (*complete)(BlockJob *job, Error **errp); 55 56 /** 57 * If the callback is not NULL, it will be invoked when all the jobs 58 * belonging to the same transaction complete; or upon this job's 59 * completion if it is not in a transaction. Skipped if NULL. 60 * 61 * All jobs will complete with a call to either .commit() or .abort() but 62 * never both. 63 */ 64 void (*commit)(BlockJob *job); 65 66 /** 67 * If the callback is not NULL, it will be invoked when any job in the 68 * same transaction fails; or upon this job's failure (due to error or 69 * cancellation) if it is not in a transaction. Skipped if NULL. 70 * 71 * All jobs will complete with a call to either .commit() or .abort() but 72 * never both. 73 */ 74 void (*abort)(BlockJob *job); 75 76 /** 77 * If the callback is not NULL, it will be invoked after a call to either 78 * .commit() or .abort(). Regardless of which callback is invoked after 79 * completion, .clean() will always be called, even if the job does not 80 * belong to a transaction group. 81 */ 82 void (*clean)(BlockJob *job); 83 84 /** 85 * If the callback is not NULL, it will be invoked when the job transitions 86 * into the paused state. Paused jobs must not perform any asynchronous 87 * I/O or event loop activity. This callback is used to quiesce jobs. 88 */ 89 void coroutine_fn (*pause)(BlockJob *job); 90 91 /** 92 * If the callback is not NULL, it will be invoked when the job transitions 93 * out of the paused state. Any asynchronous I/O or event loop activity 94 * should be restarted from this callback. 95 */ 96 void coroutine_fn (*resume)(BlockJob *job); 97 98 /* 99 * If the callback is not NULL, it will be invoked before the job is 100 * resumed in a new AioContext. This is the place to move any resources 101 * besides job->blk to the new AioContext. 102 */ 103 void (*attached_aio_context)(BlockJob *job, AioContext *new_context); 104 105 /* 106 * If the callback is not NULL, it will be invoked when the job has to be 107 * synchronously cancelled or completed; it should drain BlockDriverStates 108 * as required to ensure progress. 109 */ 110 void (*drain)(BlockJob *job); 111 }; 112 113 /** 114 * block_job_create: 115 * @job_id: The id of the newly-created job, or %NULL to have one 116 * generated automatically. 117 * @job_type: The class object for the newly-created job. 118 * @bs: The block 119 * @perm, @shared_perm: Permissions to request for @bs 120 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 121 * @cb: Completion function for the job. 122 * @opaque: Opaque pointer value passed to @cb. 123 * @errp: Error object. 124 * 125 * Create a new long-running block device job and return it. The job 126 * will call @cb asynchronously when the job completes. Note that 127 * @bs may have been closed at the time the @cb it is called. If 128 * this is the case, the job may be reported as either cancelled or 129 * completed. 130 * 131 * This function is not part of the public job interface; it should be 132 * called from a wrapper that is specific to the job type. 133 */ 134 void *block_job_create(const char *job_id, const BlockJobDriver *driver, 135 BlockDriverState *bs, uint64_t perm, 136 uint64_t shared_perm, int64_t speed, int flags, 137 BlockCompletionFunc *cb, void *opaque, Error **errp); 138 139 /** 140 * block_job_sleep_ns: 141 * @job: The job that calls the function. 142 * @ns: How many nanoseconds to stop for. 143 * 144 * Put the job to sleep (assuming that it wasn't canceled) for @ns 145 * %QEMU_CLOCK_REALTIME nanoseconds. Canceling the job will immediately 146 * interrupt the wait. 147 */ 148 void block_job_sleep_ns(BlockJob *job, int64_t ns); 149 150 /** 151 * block_job_yield: 152 * @job: The job that calls the function. 153 * 154 * Yield the block job coroutine. 155 */ 156 void block_job_yield(BlockJob *job); 157 158 /** 159 * block_job_pause_all: 160 * 161 * Asynchronously pause all jobs. 162 */ 163 void block_job_pause_all(void); 164 165 /** 166 * block_job_resume_all: 167 * 168 * Resume all block jobs. Must be paired with a preceding block_job_pause_all. 169 */ 170 void block_job_resume_all(void); 171 172 /** 173 * block_job_early_fail: 174 * @bs: The block device. 175 * 176 * The block job could not be started, free it. 177 */ 178 void block_job_early_fail(BlockJob *job); 179 180 /** 181 * block_job_completed: 182 * @job: The job being completed. 183 * @ret: The status code. 184 * 185 * Call the completion function that was registered at creation time, and 186 * free @job. 187 */ 188 void block_job_completed(BlockJob *job, int ret); 189 190 /** 191 * block_job_is_cancelled: 192 * @job: The job being queried. 193 * 194 * Returns whether the job is scheduled for cancellation. 195 */ 196 bool block_job_is_cancelled(BlockJob *job); 197 198 /** 199 * block_job_pause_point: 200 * @job: The job that is ready to pause. 201 * 202 * Pause now if block_job_pause() has been called. Block jobs that perform 203 * lots of I/O must call this between requests so that the job can be paused. 204 */ 205 void coroutine_fn block_job_pause_point(BlockJob *job); 206 207 /** 208 * block_job_enter: 209 * @job: The job to enter. 210 * 211 * Continue the specified job by entering the coroutine. 212 */ 213 void block_job_enter(BlockJob *job); 214 215 /** 216 * block_job_event_ready: 217 * @job: The job which is now ready to be completed. 218 * 219 * Send a BLOCK_JOB_READY event for the specified job. 220 */ 221 void block_job_event_ready(BlockJob *job); 222 223 /** 224 * block_job_error_action: 225 * @job: The job to signal an error for. 226 * @on_err: The error action setting. 227 * @is_read: Whether the operation was a read. 228 * @error: The error that was reported. 229 * 230 * Report an I/O error for a block job and possibly stop the VM. Return the 231 * action that was selected based on @on_err and @error. 232 */ 233 BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err, 234 int is_read, int error); 235 236 typedef void BlockJobDeferToMainLoopFn(BlockJob *job, void *opaque); 237 238 /** 239 * block_job_defer_to_main_loop: 240 * @job: The job 241 * @fn: The function to run in the main loop 242 * @opaque: The opaque value that is passed to @fn 243 * 244 * This function must be called by the main job coroutine just before it 245 * returns. @fn is executed in the main loop with the BlockDriverState 246 * AioContext acquired. Block jobs must call bdrv_unref(), bdrv_close(), and 247 * anything that uses bdrv_drain_all() in the main loop. 248 * 249 * The @job AioContext is held while @fn executes. 250 */ 251 void block_job_defer_to_main_loop(BlockJob *job, 252 BlockJobDeferToMainLoopFn *fn, 253 void *opaque); 254 255 #endif 256