blockjob_int.h (5195B)
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 * I/O API functions. These functions are thread-safe. 43 * 44 * See include/block/block-io.h for more information about 45 * the I/O API. 46 */ 47 48 /* 49 * Returns whether the job has pending requests for the child or will 50 * submit new requests before the next pause point. This callback is polled 51 * in the context of draining a job node after requesting that the job be 52 * paused, until all activity on the child has stopped. 53 */ 54 bool (*drained_poll)(BlockJob *job); 55 56 /* 57 * Global state (GS) API. These functions run under the BQL. 58 * 59 * See include/block/block-global-state.h for more information about 60 * the GS API. 61 */ 62 63 /* 64 * If the callback is not NULL, it will be invoked before the job is 65 * resumed in a new AioContext. This is the place to move any resources 66 * besides job->blk to the new AioContext. 67 */ 68 void (*attached_aio_context)(BlockJob *job, AioContext *new_context); 69 70 void (*set_speed)(BlockJob *job, int64_t speed); 71 }; 72 73 /* 74 * Global state (GS) API. These functions run under the BQL. 75 * 76 * See include/block/block-global-state.h for more information about 77 * the GS API. 78 */ 79 80 /** 81 * block_job_create: 82 * @job_id: The id of the newly-created job, or %NULL to have one 83 * generated automatically. 84 * @driver: The class object for the newly-created job. 85 * @txn: The transaction this job belongs to, if any. %NULL otherwise. 86 * @bs: The block 87 * @perm, @shared_perm: Permissions to request for @bs 88 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 89 * @flags: Creation flags for the Block Job. See @JobCreateFlags. 90 * @cb: Completion function for the job. 91 * @opaque: Opaque pointer value passed to @cb. 92 * @errp: Error object. 93 * 94 * Create a new long-running block device job and return it. The job 95 * will call @cb asynchronously when the job completes. Note that 96 * @bs may have been closed at the time the @cb it is called. If 97 * this is the case, the job may be reported as either cancelled or 98 * completed. 99 * 100 * This function is not part of the public job interface; it should be 101 * called from a wrapper that is specific to the job type. 102 */ 103 void *block_job_create(const char *job_id, const BlockJobDriver *driver, 104 JobTxn *txn, BlockDriverState *bs, uint64_t perm, 105 uint64_t shared_perm, int64_t speed, int flags, 106 BlockCompletionFunc *cb, void *opaque, Error **errp); 107 108 /** 109 * block_job_free: 110 * Callback to be used for JobDriver.free in all block jobs. Frees block job 111 * specific resources in @job. 112 */ 113 void block_job_free(Job *job); 114 115 /** 116 * block_job_user_resume: 117 * Callback to be used for JobDriver.user_resume in all block jobs. Resets the 118 * iostatus when the user resumes @job. 119 */ 120 void block_job_user_resume(Job *job); 121 122 /* 123 * I/O API functions. These functions are thread-safe. 124 * 125 * See include/block/block-io.h for more information about 126 * the I/O API. 127 */ 128 129 /** 130 * block_job_ratelimit_get_delay: 131 * 132 * Calculate and return delay for the next request in ns. See the documentation 133 * of ratelimit_calculate_delay() for details. 134 */ 135 int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n); 136 137 /** 138 * block_job_error_action: 139 * @job: The job to signal an error for. 140 * @on_err: The error action setting. 141 * @is_read: Whether the operation was a read. 142 * @error: The error that was reported. 143 * 144 * Report an I/O error for a block job and possibly stop the VM. Return the 145 * action that was selected based on @on_err and @error. 146 */ 147 BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err, 148 int is_read, int error); 149 150 #endif