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 31 /** 32 * BlockJobDriver: 33 * 34 * A class type for block job driver. 35 */ 36 struct BlockJobDriver { 37 /** Generic JobDriver callbacks and settings */ 38 JobDriver job_driver; 39 40 /* 41 * I/O API functions. These functions are thread-safe. 42 * 43 * See include/block/block-io.h for more information about 44 * the I/O API. 45 */ 46 47 /* 48 * Returns whether the job has pending requests for the child or will 49 * submit new requests before the next pause point. This callback is polled 50 * in the context of draining a job node after requesting that the job be 51 * paused, until all activity on the child has stopped. 52 */ 53 bool (*drained_poll)(BlockJob *job); 54 55 /* 56 * Global state (GS) API. These functions run under the BQL. 57 * 58 * See include/block/block-global-state.h for more information about 59 * the GS API. 60 */ 61 62 /* 63 * If the callback is not NULL, it will be invoked before the job is 64 * resumed in a new AioContext. This is the place to move any resources 65 * besides job->blk to the new AioContext. 66 */ 67 void (*attached_aio_context)(BlockJob *job, AioContext *new_context); 68 69 void (*set_speed)(BlockJob *job, int64_t speed); 70 }; 71 72 /* 73 * Global state (GS) API. These functions run under the BQL. 74 * 75 * See include/block/block-global-state.h for more information about 76 * the GS API. 77 */ 78 79 /** 80 * block_job_create: 81 * @job_id: The id of the newly-created job, or %NULL to have one 82 * generated automatically. 83 * @driver: The class object for the newly-created job. 84 * @txn: The transaction this job belongs to, if any. %NULL otherwise. 85 * @bs: The block 86 * @perm, @shared_perm: Permissions to request for @bs 87 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 88 * @flags: Creation flags for the Block Job. See @JobCreateFlags. 89 * @cb: Completion function for the job. 90 * @opaque: Opaque pointer value passed to @cb. 91 * @errp: Error object. 92 * 93 * Create a new long-running block device job and return it. The job 94 * will call @cb asynchronously when the job completes. Note that 95 * @bs may have been closed at the time the @cb it is called. If 96 * this is the case, the job may be reported as either cancelled or 97 * completed. 98 * 99 * This function is not part of the public job interface; it should be 100 * called from a wrapper that is specific to the job type. 101 */ 102 void *block_job_create(const char *job_id, const BlockJobDriver *driver, 103 JobTxn *txn, BlockDriverState *bs, uint64_t perm, 104 uint64_t shared_perm, int64_t speed, int flags, 105 BlockCompletionFunc *cb, void *opaque, Error **errp); 106 107 /** 108 * block_job_free: 109 * Callback to be used for JobDriver.free in all block jobs. Frees block job 110 * specific resources in @job. 111 */ 112 void block_job_free(Job *job); 113 114 /** 115 * block_job_user_resume: 116 * Callback to be used for JobDriver.user_resume in all block jobs. Resets the 117 * iostatus when the user resumes @job. 118 */ 119 void block_job_user_resume(Job *job); 120 121 /* 122 * I/O API functions. These functions are thread-safe. 123 * 124 * See include/block/block-io.h for more information about 125 * the I/O API. 126 */ 127 128 /** 129 * block_job_ratelimit_processed_bytes: 130 * 131 * To be called after some work has been done. Adjusts the delay for the next 132 * request. See the documentation of ratelimit_calculate_delay() for details. 133 */ 134 void block_job_ratelimit_processed_bytes(BlockJob *job, uint64_t n); 135 136 /** 137 * Put the job to sleep (assuming that it wasn't canceled) to throttle it to the 138 * right speed according to its rate limiting. 139 */ 140 void block_job_ratelimit_sleep(BlockJob *job); 141 142 /** 143 * block_job_error_action: 144 * @job: The job to signal an error for. 145 * @on_err: The error action setting. 146 * @is_read: Whether the operation was a read. 147 * @error: The error that was reported. 148 * 149 * Report an I/O error for a block job and possibly stop the VM. Return the 150 * action that was selected based on @on_err and @error. 151 */ 152 BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err, 153 int is_read, int error); 154 155 #endif 156