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