From c55a832fdddec2c350b585ade0476501f616608d Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Thu, 5 Nov 2015 18:13:15 -0500 Subject: block: Add block job transactions Sometimes block jobs must execute as a transaction group. Finishing jobs wait until all other jobs are ready to complete successfully. Failure or cancellation of one job cancels the other jobs in the group. Signed-off-by: Stefan Hajnoczi Reviewed-by: Max Reitz Signed-off-by: Fam Zheng Signed-off-by: John Snow Message-id: 1446765200-3054-10-git-send-email-jsnow@redhat.com [Rewrite the implementation which is now contained in block_job_completed. --Fam] Signed-off-by: Fam Zheng Reviewed-by: Max Reitz Signed-off-by: John Snow Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- include/block/block.h | 1 + include/block/blockjob.h | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) (limited to 'include') diff --git a/include/block/block.h b/include/block/block.h index 92f6f6a..73edb1a 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -14,6 +14,7 @@ typedef struct BlockDriver BlockDriver; typedef struct BlockJob BlockJob; typedef struct BdrvChild BdrvChild; typedef struct BdrvChildRole BdrvChildRole; +typedef struct BlockJobTxn BlockJobTxn; typedef struct BlockDriverInfo { /* in bytes, 0 if irrelevant */ diff --git a/include/block/blockjob.h b/include/block/blockjob.h index c70d55a..d84ccd8 100644 --- a/include/block/blockjob.h +++ b/include/block/blockjob.h @@ -162,6 +162,9 @@ struct BlockJob { */ int ret; + /** Non-NULL if this job is part of a transaction */ + BlockJobTxn *txn; + QLIST_ENTRY(BlockJob) txn_list; }; /** @@ -405,4 +408,39 @@ void block_job_defer_to_main_loop(BlockJob *job, BlockJobDeferToMainLoopFn *fn, void *opaque); +/** + * block_job_txn_new: + * + * Allocate and return a new block job transaction. Jobs can be added to the + * transaction using block_job_txn_add_job(). + * + * The transaction is automatically freed when the last job completes or is + * cancelled. + * + * All jobs in the transaction either complete successfully or fail/cancel as a + * group. Jobs wait for each other before completing. Cancelling one job + * cancels all jobs in the transaction. + */ +BlockJobTxn *block_job_txn_new(void); + +/** + * block_job_txn_unref: + * + * Release a reference that was previously acquired with block_job_txn_add_job + * or block_job_txn_new. If it's the last reference to the object, it will be + * freed. + */ +void block_job_txn_unref(BlockJobTxn *txn); + +/** + * block_job_txn_add_job: + * @txn: The transaction (may be NULL) + * @job: Job to add to the transaction + * + * Add @job to the transaction. The @job must not already be in a transaction. + * The caller must call either block_job_txn_unref() or block_job_completed() + * to release the reference that is automatically grabbed here. + */ +void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job); + #endif -- cgit v1.1