block/block-copy: rename in-flight requests to tasks

We are going to use aio-task-pool API and extend in-flight request
structure to be a successor of AioTask, so rename things appropriately.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200429130847.28124-2-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

block/block-copy.c

@@ -24,12 +24,12 @@
 #define BLOCK_COPY_MAX_BUFFER (1 * MiB)
 #define BLOCK_COPY_MAX_MEM (128 * MiB)
 
-typedef struct BlockCopyInFlightReq {
+typedef struct BlockCopyTask {
     int64_t offset;
     int64_t bytes;
-    QLIST_ENTRY(BlockCopyInFlightReq) list;
-    CoQueue wait_queue; /* coroutines blocked on this request */
-} BlockCopyInFlightReq;
+    QLIST_ENTRY(BlockCopyTask) list;
+    CoQueue wait_queue; /* coroutines blocked on this task */
+} BlockCopyTask;
 
 typedef struct BlockCopyState {
     /*
@@ -45,7 +45,7 @@ typedef struct BlockCopyState {
     bool use_copy_range;
     int64_t copy_size;
     uint64_t len;
-    QLIST_HEAD(, BlockCopyInFlightReq) inflight_reqs;
+    QLIST_HEAD(, BlockCopyTask) tasks;
 
     BdrvRequestFlags write_flags;
 
@@ -73,89 +73,87 @@ typedef struct BlockCopyState {
     SharedResource *mem;
 } BlockCopyState;
 
-static BlockCopyInFlightReq *find_conflicting_inflight_req(BlockCopyState *s,
-                                                           int64_t offset,
-                                                           int64_t bytes)
+static BlockCopyTask *find_conflicting_task(BlockCopyState *s,
+                                            int64_t offset, int64_t bytes)
 {
-    BlockCopyInFlightReq *req;
+    BlockCopyTask *t;
 
-    QLIST_FOREACH(req, &s->inflight_reqs, list) {
-        if (offset + bytes > req->offset && offset < req->offset + req->bytes) {
-            return req;
+    QLIST_FOREACH(t, &s->tasks, list) {
+        if (offset + bytes > t->offset && offset < t->offset + t->bytes) {
+            return t;
         }
     }
 
     return NULL;
 }
 
 /*
- * If there are no intersecting requests return false. Otherwise, wait for the
- * first found intersecting request to finish and return true.
+ * If there are no intersecting tasks return false. Otherwise, wait for the
+ * first found intersecting tasks to finish and return true.
  */
 static bool coroutine_fn block_copy_wait_one(BlockCopyState *s, int64_t offset,
                                              int64_t bytes)
 {
-    BlockCopyInFlightReq *req = find_conflicting_inflight_req(s, offset, bytes);
+    BlockCopyTask *task = find_conflicting_task(s, offset, bytes);
 
-    if (!req) {
+    if (!task) {
         return false;
     }
 
-    qemu_co_queue_wait(&req->wait_queue, NULL);
+    qemu_co_queue_wait(&task->wait_queue, NULL);
 
     return true;
 }
 
 /* Called only on full-dirty region */
-static void block_copy_inflight_req_begin(BlockCopyState *s,
-                                          BlockCopyInFlightReq *req,
-                                          int64_t offset, int64_t bytes)
+static void block_copy_task_begin(BlockCopyState *s, BlockCopyTask *task,
+                                  int64_t offset, int64_t bytes)
 {
-    assert(!find_conflicting_inflight_req(s, offset, bytes));
+    assert(!find_conflicting_task(s, offset, bytes));
 
     bdrv_reset_dirty_bitmap(s->copy_bitmap, offset, bytes);
     s->in_flight_bytes += bytes;
 
-    req->offset = offset;
-    req->bytes = bytes;
-    qemu_co_queue_init(&req->wait_queue);
-    QLIST_INSERT_HEAD(&s->inflight_reqs, req, list);
+    task->offset = offset;
+    task->bytes = bytes;
+    qemu_co_queue_init(&task->wait_queue);
+    QLIST_INSERT_HEAD(&s->tasks, task, list);
 }
 
 /*
- * block_copy_inflight_req_shrink
+ * block_copy_task_shrink
  *
- * Drop the tail of the request to be handled later. Set dirty bits back and
- * wake up all requests waiting for us (may be some of them are not intersecting
- * with shrunk request)
+ * Drop the tail of the task to be handled later. Set dirty bits back and
+ * wake up all tasks waiting for us (may be some of them are not intersecting
+ * with shrunk task)
  */
-static void coroutine_fn block_copy_inflight_req_shrink(BlockCopyState *s,
-        BlockCopyInFlightReq *req, int64_t new_bytes)
+static void coroutine_fn block_copy_task_shrink(BlockCopyState *s,
+                                                BlockCopyTask *task,
+                                                int64_t new_bytes)
 {
-    if (new_bytes == req->bytes) {
+    if (new_bytes == task->bytes) {
         return;
     }
 
-    assert(new_bytes > 0 && new_bytes < req->bytes);
+    assert(new_bytes > 0 && new_bytes < task->bytes);
 
-    s->in_flight_bytes -= req->bytes - new_bytes;
+    s->in_flight_bytes -= task->bytes - new_bytes;
     bdrv_set_dirty_bitmap(s->copy_bitmap,
-                          req->offset + new_bytes, req->bytes - new_bytes);
+                          task->offset + new_bytes, task->bytes - new_bytes);
 
-    req->bytes = new_bytes;
-    qemu_co_queue_restart_all(&req->wait_queue);
+    task->bytes = new_bytes;
+    qemu_co_queue_restart_all(&task->wait_queue);
 }
 
-static void coroutine_fn block_copy_inflight_req_end(BlockCopyState *s,
-                                                     BlockCopyInFlightReq *req,
-                                                     int ret)
+static void coroutine_fn block_copy_task_end(BlockCopyState *s,
+                                             BlockCopyTask *task, int ret)
 {
-    s->in_flight_bytes -= req->bytes;
+    s->in_flight_bytes -= task->bytes;
     if (ret < 0) {
-        bdrv_set_dirty_bitmap(s->copy_bitmap, req->offset, req->bytes);
+        bdrv_set_dirty_bitmap(s->copy_bitmap, task->offset, task->bytes);
     }
-    QLIST_REMOVE(req, list);
-    qemu_co_queue_restart_all(&req->wait_queue);
+    QLIST_REMOVE(task, list);
+    qemu_co_queue_restart_all(&task->wait_queue);
 }
 
 void block_copy_state_free(BlockCopyState *s)
@@ -223,7 +221,7 @@ BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target,
         s->copy_size = MAX(s->cluster_size, BLOCK_COPY_MAX_BUFFER);
     }
 
-    QLIST_INIT(&s->inflight_reqs);
+    QLIST_INIT(&s->tasks);
 
     return s;
 }
@@ -474,7 +472,7 @@ static int coroutine_fn block_copy_dirty_clusters(BlockCopyState *s,
     assert(QEMU_IS_ALIGNED(bytes, s->cluster_size));
 
     while (bytes) {
-        BlockCopyInFlightReq req;
+        BlockCopyTask task;
         int64_t next_zero, cur_bytes, status_bytes;
 
         if (!bdrv_dirty_bitmap_get(s->copy_bitmap, offset)) {
@@ -495,14 +493,14 @@ static int coroutine_fn block_copy_dirty_clusters(BlockCopyState *s,
             assert(next_zero < offset + cur_bytes); /* no need to do MIN() */
             cur_bytes = next_zero - offset;
         }
-        block_copy_inflight_req_begin(s, &req, offset, cur_bytes);
+        block_copy_task_begin(s, &task, offset, cur_bytes);
 
         ret = block_copy_block_status(s, offset, cur_bytes, &status_bytes);
         assert(ret >= 0); /* never fail */
         cur_bytes = MIN(cur_bytes, status_bytes);
-        block_copy_inflight_req_shrink(s, &req, cur_bytes);
+        block_copy_task_shrink(s, &task, cur_bytes);
         if (s->skip_unallocated && !(ret & BDRV_BLOCK_ALLOCATED)) {
-            block_copy_inflight_req_end(s, &req, 0);
+            block_copy_task_end(s, &task, 0);
             progress_set_remaining(s->progress,
                                    bdrv_get_dirty_count(s->copy_bitmap) +
                                    s->in_flight_bytes);
@@ -518,7 +516,7 @@ static int coroutine_fn block_copy_dirty_clusters(BlockCopyState *s,
         ret = block_copy_do_copy(s, offset, cur_bytes, ret & BDRV_BLOCK_ZERO,
                                  error_is_read);
         co_put_to_shres(s->mem, cur_bytes);
-        block_copy_inflight_req_end(s, &req, ret);
+        block_copy_task_end(s, &task, ret);
         if (ret < 0) {
             return ret;
         }