Merge remote-tracking branch 'remotes/vsementsov/tags/pull-jobs-2021-06-25' into staging

block: Make block-copy API thread-safe

# gpg: Signature made Fri 25 Jun 2021 13:40:24 BST
# gpg:                using RSA key 8B9C26CDB2FD147C880E86A1561F24C1F19F79FB
# gpg: Good signature from "Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>" [unknown]
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* remotes/vsementsov/tags/pull-jobs-2021-06-25:
  block-copy: atomic .cancelled and .finished fields in BlockCopyCallState
  block-copy: add CoMutex lock
  block-copy: move progress_set_remaining in block_copy_task_end
  block-copy: streamline choice of copy_range vs. read/write
  block-copy: small refactor in block_copy_task_entry and block_copy_common
  co-shared-resource: protect with a mutex
  progressmeter: protect with a mutex
  blockjob: let ratelimit handle a speed of 0
  block-copy: let ratelimit handle a speed of 0
  ratelimit: treat zero speed as unlimited

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

4 files changed, 32 insertions, 20 deletions

diff --git a/include/block/block-copy.h b/include/block/block-copy.h
index 338f2ea..5c82788 100644
--- a/include/block/block-copy.h
+++ b/include/block/block-copy.h
@@ -18,6 +18,8 @@
 #include "block/block.h"
 #include "qemu/co-shared-resource.h"
 
+/* All APIs are thread-safe */
+
 typedef void (*BlockCopyAsyncCallbackFunc)(void *opaque);
 typedef struct BlockCopyState BlockCopyState;
 typedef struct BlockCopyCallState BlockCopyCallState;
diff --git a/include/qemu/co-shared-resource.h b/include/qemu/co-shared-resource.h
index 4e45030..78ca585 100644
--- a/include/qemu/co-shared-resource.h
+++ b/include/qemu/co-shared-resource.h
@@ -26,15 +26,13 @@
 #ifndef QEMU_CO_SHARED_RESOURCE_H
 #define QEMU_CO_SHARED_RESOURCE_H
 
-
+/* Accesses to co-shared-resource API are thread-safe */
 typedef struct SharedResource SharedResource;
 
 /*
  * Create SharedResource structure
  *
  * @total: total amount of some resource to be shared between clients
- *
- * Note: this API is not thread-safe.
  */
 SharedResource *shres_create(uint64_t total);
 
diff --git a/include/qemu/progress_meter.h b/include/qemu/progress_meter.h
index 9a23ff0..dadf822 100644
--- a/include/qemu/progress_meter.h
+++ b/include/qemu/progress_meter.h
@@ -27,6 +27,8 @@
 #ifndef QEMU_PROGRESS_METER_H
 #define QEMU_PROGRESS_METER_H
 
+#include "qemu/lockable.h"
+
 typedef struct ProgressMeter {
     /**
      * Current progress. The unit is arbitrary as long as the ratio between
@@ -37,22 +39,24 @@ typedef struct ProgressMeter {
 
     /** Estimated current value at the completion of the process */
     uint64_t total;
+
+    QemuMutex lock; /* protects concurrent access to above fields */
 } ProgressMeter;
 
-static inline void progress_work_done(ProgressMeter *pm, uint64_t done)
-{
-    pm->current += done;
-}
-
-static inline void progress_set_remaining(ProgressMeter *pm, uint64_t remaining)
-{
-    pm->total = pm->current + remaining;
-}
-
-static inline void progress_increase_remaining(ProgressMeter *pm,
-                                               uint64_t delta)
-{
-    pm->total += delta;
-}
+void progress_init(ProgressMeter *pm);
+void progress_destroy(ProgressMeter *pm);
+
+/* Get a snapshot of internal current and total values  */
+void progress_get_snapshot(ProgressMeter *pm, uint64_t *current,
+                           uint64_t *total);
+
+/* Increases the amount of work done so far by @done */
+void progress_work_done(ProgressMeter *pm, uint64_t done);
+
+/* Sets how much work has to be done to complete to @remaining */
+void progress_set_remaining(ProgressMeter *pm, uint64_t remaining);
+
+/* Increases the total work to do by @delta */
+void progress_increase_remaining(ProgressMeter *pm, uint64_t delta);
 
 #endif /* QEMU_PROGRESS_METER_H */
diff --git a/include/qemu/ratelimit.h b/include/qemu/ratelimit.h
index 003ea6d..48bf59e 100644
--- a/include/qemu/ratelimit.h
+++ b/include/qemu/ratelimit.h
@@ -43,7 +43,11 @@ static inline int64_t ratelimit_calculate_delay(RateLimit *limit, uint64_t n)
     double delay_slices;
 
     QEMU_LOCK_GUARD(&limit->lock);
-    assert(limit->slice_quota && limit->slice_ns);
+    if (!limit->slice_quota) {
+        /* Throttling disabled.  */
+        return 0;
+    }
+    assert(limit->slice_ns);
 
     if (limit->slice_end_time < now) {
         /* Previous, possibly extended, time slice finished; reset the
@@ -83,7 +87,11 @@ static inline void ratelimit_set_speed(RateLimit *limit, uint64_t speed,
 {
     QEMU_LOCK_GUARD(&limit->lock);
     limit->slice_ns = slice_ns;
-    limit->slice_quota = MAX(((double)speed * slice_ns) / 1000000000ULL, 1);
+    if (speed == 0) {
+        limit->slice_quota = 0;
+    } else {
+        limit->slice_quota = MAX(((double)speed * slice_ns) / 1000000000ULL, 1);
+    }
 }
 
 #endif