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 /** Generic JobDriver callbacks and settings */ 39 JobDriver job_driver; 40 41 /* 42 * Returns whether the job has pending requests for the child or will 43 * submit new requests before the next pause point. This callback is polled 44 * in the context of draining a job node after requesting that the job be 45 * paused, until all activity on the child has stopped. 46 */ 47 bool (*drained_poll)(BlockJob *job); 48 49 /* 50 * If the callback is not NULL, it will be invoked before the job is 51 * resumed in a new AioContext. This is the place to move any resources 52 * besides job->blk to the new AioContext. 53 */ 54 void (*attached_aio_context)(BlockJob *job, AioContext *new_context); 55 56 /* 57 * If the callback is not NULL, it will be invoked when the job has to be 58 * synchronously cancelled or completed; it should drain BlockDriverStates 59 * as required to ensure progress. 60 * 61 * Block jobs must use the default implementation for job_driver.drain, 62 * which will in turn call this callback after doing generic block job 63 * stuff. 64 */ 65 void (*drain)(BlockJob *job); 66 }; 67 68 /** 69 * block_job_create: 70 * @job_id: The id of the newly-created job, or %NULL to have one 71 * generated automatically. 72 * @driver: The class object for the newly-created job. 73 * @txn: The transaction this job belongs to, if any. %NULL otherwise. 74 * @bs: The block 75 * @perm, @shared_perm: Permissions to request for @bs 76 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 77 * @flags: Creation flags for the Block Job. See @JobCreateFlags. 78 * @cb: Completion function for the job. 79 * @opaque: Opaque pointer value passed to @cb. 80 * @errp: Error object. 81 * 82 * Create a new long-running block device job and return it. The job 83 * will call @cb asynchronously when the job completes. Note that 84 * @bs may have been closed at the time the @cb it is called. If 85 * this is the case, the job may be reported as either cancelled or 86 * completed. 87 * 88 * This function is not part of the public job interface; it should be 89 * called from a wrapper that is specific to the job type. 90 */ 91 void *block_job_create(const char *job_id, const BlockJobDriver *driver, 92 JobTxn *txn, BlockDriverState *bs, uint64_t perm, 93 uint64_t shared_perm, int64_t speed, int flags, 94 BlockCompletionFunc *cb, void *opaque, Error **errp); 95 96 /** 97 * block_job_free: 98 * Callback to be used for JobDriver.free in all block jobs. Frees block job 99 * specific resources in @job. 100 */ 101 void block_job_free(Job *job); 102 103 /** 104 * block_job_user_resume: 105 * Callback to be used for JobDriver.user_resume in all block jobs. Resets the 106 * iostatus when the user resumes @job. 107 */ 108 void block_job_user_resume(Job *job); 109 110 /** 111 * block_job_drain: 112 * Callback to be used for JobDriver.drain in all block jobs. Drains the main 113 * block node associated with the block jobs and calls BlockJobDriver.drain for 114 * job-specific actions. 115 */ 116 void block_job_drain(Job *job); 117 118 /** 119 * block_job_ratelimit_get_delay: 120 * 121 * Calculate and return delay for the next request in ns. See the documentation 122 * of ratelimit_calculate_delay() for details. 123 */ 124 int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n); 125 126 /** 127 * block_job_error_action: 128 * @job: The job to signal an error for. 129 * @on_err: The error action setting. 130 * @is_read: Whether the operation was a read. 131 * @error: The error that was reported. 132 * 133 * Report an I/O error for a block job and possibly stop the VM. Return the 134 * action that was selected based on @on_err and @error. 135 */ 136 BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err, 137 int is_read, int error); 138 139 #endif 140