[v10,02/16] block: Add block_job_add_bdrv()

Commit Message

Alberto Garcia Oct. 6, 2016, 1:02 p.m. UTC

When a block job is created on a certain BlockDriverState, operations
are blocked there while the job exists. However, some block jobs may
involve additional BDSs, which must be blocked separately when the job
is created and unblocked manually afterwards.

This patch adds block_job_add_bdrv(), that simplifies this process by
keeping a list of BDSs that are involved in the specified block job.

Signed-off-by: Alberto Garcia <[e-mail]>
---
 blockjob.c               | 19 ++++++++++++++++---
 include/block/blockjob.h | 14 ++++++++++++++
 2 files changed, 30 insertions(+), 3 deletions(-)

Comments

Kevin Wolf Oct. 10, 2016, 3:46 p.m. UTC | #1

Am 06.10.2016 um 15:02 hat Alberto Garcia geschrieben:
> When a block job is created on a certain BlockDriverState, operations
> are blocked there while the job exists. However, some block jobs may
> involve additional BDSs, which must be blocked separately when the job
> is created and unblocked manually afterwards.
> 
> This patch adds block_job_add_bdrv(), that simplifies this process by
> keeping a list of BDSs that are involved in the specified block job.
> 
> Signed-off-by: Alberto Garcia <[e-mail]>

Reviewed-by: Kevin Wolf <[e-mail]>

Patch

diff --git a/blockjob.c b/blockjob.c
index a167f96..b2486a7 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -117,6 +117,14 @@  static void block_job_detach_aio_context(void *opaque)
     block_job_unref(job);
 }
 
+void block_job_add_bdrv(BlockJob *job, BlockDriverState *bs)
+{
+    job->nodes = g_slist_prepend(job->nodes, bs);
+    bdrv_ref(bs);
+    bdrv_op_block_all(bs, job->blocker);
+    bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
+}
+
 void *block_job_create(const char *job_id, const BlockJobDriver *driver,
                        BlockDriverState *bs, int64_t speed,
                        BlockCompletionFunc *cb, void *opaque, Error **errp)
@@ -154,8 +162,7 @@  void *block_job_create(const char *job_id, const BlockJobDriver *driver,
     job = g_malloc0(driver->instance_size);
     error_setg(&job->blocker, "block device is in use by block job: %s",
                BlockJobType_lookup[driver->job_type]);
-    bdrv_op_block_all(bs, job->blocker);
-    bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
+    block_job_add_bdrv(job, bs);
 
     job->driver        = driver;
     job->id            = g_strdup(job_id);
@@ -193,9 +200,15 @@  void block_job_ref(BlockJob *job)
 void block_job_unref(BlockJob *job)
 {
     if (--job->refcnt == 0) {
+        GSList *l;
         BlockDriverState *bs = blk_bs(job->blk);
         bs->job = NULL;
-        bdrv_op_unblock_all(bs, job->blocker);
+        for (l = job->nodes; l; l = l->next) {
+            bs = l->data;
+            bdrv_op_unblock_all(bs, job->blocker);
+            bdrv_unref(bs);
+        }
+        g_slist_free(job->nodes);
         blk_remove_aio_context_notifier(job->blk,
                                         block_job_attached_aio_context,
                                         block_job_detach_aio_context, job);
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index 4ddb4ae..c7335f3 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -181,6 +181,9 @@  struct BlockJob {
     /** Block other operations when block job is running */
     Error *blocker;
 
+    /** BlockDriverStates that are involved in this block job */
+    GSList *nodes;
+
     /** The opaque value that is passed to the completion function.  */
     void *opaque;
 
@@ -246,6 +249,17 @@  void *block_job_create(const char *job_id, const BlockJobDriver *driver,
                        BlockCompletionFunc *cb, void *opaque, Error **errp);
 
 /**
+ * block_job_add_bdrv:
+ * @job: A block job
+ * @bs: A BlockDriverState that is involved in @job
+ *
+ * Add @bs to the list of BlockDriverState that are involved in
+ * @job. This means that all operations (except dataplane) will be
+ * blocked on @bs while @job exists.
+ */
+void block_job_add_bdrv(BlockJob *job, BlockDriverState *bs);
+
+/**
  * block_job_sleep_ns:
  * @job: The job that calls the function.
  * @clock: The clock to sleep on.