aboutsummaryrefslogtreecommitdiff
path: root/include
diff options
context:
space:
mode:
authorFam Zheng <famz@redhat.com>2015-11-05 18:13:15 -0500
committerKevin Wolf <kwolf@redhat.com>2015-11-12 16:22:44 +0100
commitc55a832fdddec2c350b585ade0476501f616608d (patch)
tree093da970af4e287f4c69791af1bf10b829a24c08 /include
parent94db6d2d30962cc0422a69c88c3b3e9981b33e50 (diff)
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 <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com> 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 <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'include')
-rw-r--r--include/block/block.h1
-rw-r--r--include/block/blockjob.h38
2 files changed, 39 insertions, 0 deletions
diff --git a/include/block/block.h b/include/block/block.h
index 92f6f6a95a..73edb1a79c 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 c70d55a644..d84ccd8d2c 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