blockjob: introduce block_job _locked() APIs

Just as done with job.h, create _locked() functions in blockjob.h

These functions will be later useful when caller has already taken
the lock. All blockjob _locked functions call job _locked functions.

Note: at this stage, job_{lock/unlock} and job lock guard macros
are *nop*.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220926093214.506243-8-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

blockjob.c

@@ -44,21 +44,27 @@ static bool is_block_job(Job *job)
            job_type(job) == JOB_TYPE_STREAM;
 }
 
-BlockJob *block_job_next(BlockJob *bjob)
+BlockJob *block_job_next_locked(BlockJob *bjob)
 {
     Job *job = bjob ? &bjob->job : NULL;
     GLOBAL_STATE_CODE();
 
     do {
-        job = job_next(job);
+        job = job_next_locked(job);
     } while (job && !is_block_job(job));
 
     return job ? container_of(job, BlockJob, job) : NULL;
 }
 
-BlockJob *block_job_get(const char *id)
+BlockJob *block_job_next(BlockJob *bjob)
 {
-    Job *job = job_get(id);
+    JOB_LOCK_GUARD();
+    return block_job_next_locked(bjob);
+}
+
+BlockJob *block_job_get_locked(const char *id)
+{
+    Job *job = job_get_locked(id);
     GLOBAL_STATE_CODE();
 
     if (job && is_block_job(job)) {
@@ -68,6 +74,12 @@ BlockJob *block_job_get(const char *id)
     }
 }
 
+BlockJob *block_job_get(const char *id)
+{
+    JOB_LOCK_GUARD();
+    return block_job_get_locked(id);
+}
+
 void block_job_free(Job *job)
 {
     BlockJob *bjob = container_of(job, BlockJob, job);
@@ -256,14 +268,14 @@ static bool job_timer_pending(Job *job)
     return timer_pending(&job->sleep_timer);
 }
 
-bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
+bool block_job_set_speed_locked(BlockJob *job, int64_t speed, Error **errp)
 {
     const BlockJobDriver *drv = block_job_driver(job);
     int64_t old_speed = job->speed;
 
     GLOBAL_STATE_CODE();
 
-    if (job_apply_verb(&job->job, JOB_VERB_SET_SPEED, errp) < 0) {
+    if (job_apply_verb_locked(&job->job, JOB_VERB_SET_SPEED, errp) < 0) {
         return false;
     }
     if (speed < 0) {
@@ -277,7 +289,9 @@ bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
     job->speed = speed;
 
     if (drv->set_speed) {
+        job_unlock();
         drv->set_speed(job, speed);
+        job_lock();
     }
 
     if (speed && speed <= old_speed) {
@@ -285,18 +299,24 @@ bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
     }
 
     /* kick only if a timer is pending */
-    job_enter_cond(&job->job, job_timer_pending);
+    job_enter_cond_locked(&job->job, job_timer_pending);
 
     return true;
 }
 
+bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
+{
+    JOB_LOCK_GUARD();
+    return block_job_set_speed_locked(job, speed, errp);
+}
+
 int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n)
 {
     IO_CODE();
     return ratelimit_calculate_delay(&job->limit, n);
 }
 
-BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
+BlockJobInfo *block_job_query_locked(BlockJob *job, Error **errp)
 {
     BlockJobInfo *info;
     uint64_t progress_current, progress_total;
@@ -320,7 +340,7 @@ BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
     info->len       = progress_total;
     info->speed     = job->speed;
     info->io_status = job->iostatus;
-    info->ready     = job_is_ready(&job->job),
+    info->ready     = job_is_ready_locked(&job->job),
     info->status    = job->job.status;
     info->auto_finalize = job->job.auto_finalize;
     info->auto_dismiss  = job->job.auto_dismiss;
@@ -333,6 +353,12 @@ BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
     return info;
 }
 
+BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
+{
+    JOB_LOCK_GUARD();
+    return block_job_query_locked(job, errp);
+}
+
 static void block_job_iostatus_set_err(BlockJob *job, int error)
 {
     if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
@@ -478,7 +504,7 @@ fail:
     return NULL;
 }
 
-void block_job_iostatus_reset(BlockJob *job)
+void block_job_iostatus_reset_locked(BlockJob *job)
 {
     GLOBAL_STATE_CODE();
     if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
@@ -488,6 +514,12 @@ void block_job_iostatus_reset(BlockJob *job)
     job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
 }
 
+void block_job_iostatus_reset(BlockJob *job)
+{
+    JOB_LOCK_GUARD();
+    block_job_iostatus_reset_locked(job);
+}
+
 void block_job_user_resume(Job *job)
 {
     BlockJob *bjob = container_of(job, BlockJob, job);

include/block/blockjob.h

@@ -92,6 +92,9 @@ typedef struct BlockJob {
  */
 BlockJob *block_job_next(BlockJob *job);
 
+/* Same as block_job_next(), but called with job lock held. */
+BlockJob *block_job_next_locked(BlockJob *job);
+
 /**
  * block_job_get:
  * @id: The id of the block job.
@@ -102,6 +105,9 @@ BlockJob *block_job_next(BlockJob *job);
  */
 BlockJob *block_job_get(const char *id);
 
+/* Same as block_job_get(), but called with job lock held. */
+BlockJob *block_job_get_locked(const char *id);
+
 /**
  * block_job_add_bdrv:
  * @job: A block job
@@ -145,6 +151,12 @@ bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs);
  */
 bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp);
 
+/*
+ * Same as block_job_set_speed(), but called with job lock held.
+ * Might release the lock temporarily.
+ */
+bool block_job_set_speed_locked(BlockJob *job, int64_t speed, Error **errp);
+
 /**
  * block_job_query:
  * @job: The job to get information about.
@@ -153,6 +165,9 @@ bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp);
  */
 BlockJobInfo *block_job_query(BlockJob *job, Error **errp);
 
+/* Same as block_job_query(), but called with job lock held. */
+BlockJobInfo *block_job_query_locked(BlockJob *job, Error **errp);
+
 /**
  * block_job_iostatus_reset:
  * @job: The job whose I/O status should be reset.
@@ -162,6 +177,9 @@ BlockJobInfo *block_job_query(BlockJob *job, Error **errp);
  */
 void block_job_iostatus_reset(BlockJob *job);
 
+/* Same as block_job_iostatus_reset(), but called with job lock held. */
+void block_job_iostatus_reset_locked(BlockJob *job);
+
 /*
  * block_job_get_aio_context:
  *