progressmeter: protect with a mutex

Progressmeter is protected by the AioContext mutex, which
is taken by the block jobs and their caller (like blockdev).

We would like to remove the dependency of block layer code on the
AioContext mutex, since most drivers and the core I/O code are already
not relying on it.

Create a new C file to implement the ProgressMeter API, but keep the
struct as public, to avoid forcing allocation on the heap.

Also add a mutex to be able to provide an accurate snapshot of the
progress values to the caller.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20210614081130.22134-5-eesposit@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

1 files changed, 25 insertions, 8 deletions

diff --git a/blockjob.c b/blockjob.c
index 22e5bb9b1f..4bad1408cb 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -306,18 +306,23 @@ int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n)
 BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
 {
     BlockJobInfo *info;
+    uint64_t progress_current, progress_total;
 
     if (block_job_is_internal(job)) {
         error_setg(errp, "Cannot query QEMU internal jobs");
         return NULL;
     }
+
+    progress_get_snapshot(&job->job.progress, &progress_current,
+                          &progress_total);
+
     info = g_new0(BlockJobInfo, 1);
     info->type      = g_strdup(job_type_str(&job->job));
     info->device    = g_strdup(job->job.id);
     info->busy      = qatomic_read(&job->job.busy);
     info->paused    = job->job.pause_count > 0;
-    info->offset    = job->job.progress.current;
-    info->len       = job->job.progress.total;
+    info->offset    = progress_current;
+    info->len       = progress_total;
     info->speed     = job->speed;
     info->io_status = job->iostatus;
     info->ready     = job_is_ready(&job->job),
@@ -344,15 +349,19 @@ static void block_job_iostatus_set_err(BlockJob *job, int error)
 static void block_job_event_cancelled(Notifier *n, void *opaque)
 {
     BlockJob *job = opaque;
+    uint64_t progress_current, progress_total;
 
     if (block_job_is_internal(job)) {
         return;
     }
 
+    progress_get_snapshot(&job->job.progress, &progress_current,
+                          &progress_total);
+
     qapi_event_send_block_job_cancelled(job_type(&job->job),
                                         job->job.id,
-                                        job->job.progress.total,
-                                        job->job.progress.current,
+                                        progress_total,
+                                        progress_current,
                                         job->speed);
 }
 
@@ -360,6 +369,7 @@ static void block_job_event_completed(Notifier *n, void *opaque)
 {
     BlockJob *job = opaque;
     const char *msg = NULL;
+    uint64_t progress_current, progress_total;
 
     if (block_job_is_internal(job)) {
         return;
@@ -369,10 +379,13 @@ static void block_job_event_completed(Notifier *n, void *opaque)
         msg = error_get_pretty(job->job.err);
     }
 
+    progress_get_snapshot(&job->job.progress, &progress_current,
+                          &progress_total);
+
     qapi_event_send_block_job_completed(job_type(&job->job),
                                         job->job.id,
-                                        job->job.progress.total,
-                                        job->job.progress.current,
+                                        progress_total,
+                                        progress_current,
                                         job->speed,
                                         !!msg,
                                         msg);
@@ -393,15 +406,19 @@ static void block_job_event_pending(Notifier *n, void *opaque)
 static void block_job_event_ready(Notifier *n, void *opaque)
 {
     BlockJob *job = opaque;
+    uint64_t progress_current, progress_total;
 
     if (block_job_is_internal(job)) {
         return;
     }
 
+    progress_get_snapshot(&job->job.progress, &progress_current,
+                          &progress_total);
+
     qapi_event_send_block_job_ready(job_type(&job->job),
                                     job->job.id,
-                                    job->job.progress.total,
-                                    job->job.progress.current,
+                                    progress_total,
+                                    progress_current,
                                     job->speed);
 }