[Qemu-devel] [RFC PATCH 13/14] COW: move cow interfaces to a seperate file

[Wen Congyang]

Signed-off-by: Wen Congyang <address@hidden>
Signed-off-by: zhanghailiang <address@hidden>
Signed-off-by: Gonglei <address@hidden>
---
 Makefile.objs         |  2 +-
 block/backup.c        | 52 ++++-----------------------------------------------
 blockcow.c            | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++
 include/block/block.h | 17 +++++++++++++++++
 4 files changed, 74 insertions(+), 49 deletions(-)
 create mode 100644 blockcow.c

diff --git a/Makefile.objs b/Makefile.objs
index 28999d3..91bba07 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -7,7 +7,7 @@ util-obj-y = util/ qobject/ qapi/ qapi-types.o qapi-visit.o 
qapi-event.o
 # block-obj-y is code used by both qemu system emulation and qemu-img
 
 block-obj-y = async.o thread-pool.o
-block-obj-y += nbd.o block.o blockjob.o
+block-obj-y += nbd.o block.o blockjob.o blockcow.o
 block-obj-y += main-loop.o iohandler.o qemu-timer.o
 block-obj-$(CONFIG_POSIX) += aio-posix.o
 block-obj-$(CONFIG_WIN32) += aio-win32.o
diff --git a/block/backup.c b/block/backup.c
index 1c535b1..2816b9a 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -27,13 +27,6 @@
 
 #define SLICE_TIME 100000000ULL /* ns */
 
-typedef struct CowRequest {
-    int64_t start;
-    int64_t end;
-    QLIST_ENTRY(CowRequest) list;
-    CoQueue wait_queue; /* coroutines blocked on this request */
-} CowRequest;
-
 typedef struct BackupBlockJob {
     BlockJob common;
     BlockDriverState *target;
@@ -44,46 +37,9 @@ typedef struct BackupBlockJob {
     CoRwlock flush_rwlock;
     uint64_t sectors_read;
     HBitmap *bitmap;
-    QLIST_HEAD(, CowRequest) inflight_reqs;
+    CowJob cow_job;
 } BackupBlockJob;
 
-/* See if in-flight requests overlap and wait for them to complete */
-static void coroutine_fn wait_for_overlapping_requests(BackupBlockJob *job,
-                                                       int64_t start,
-                                                       int64_t end)
-{
-    CowRequest *req;
-    bool retry;
-
-    do {
-        retry = false;
-        QLIST_FOREACH(req, &job->inflight_reqs, list) {
-            if (end > req->start && start < req->end) {
-                qemu_co_queue_wait(&req->wait_queue);
-                retry = true;
-                break;
-            }
-        }
-    } while (retry);
-}
-
-/* Keep track of an in-flight request */
-static void cow_request_begin(CowRequest *req, BackupBlockJob *job,
-                                     int64_t start, int64_t end)
-{
-    req->start = start;
-    req->end = end;
-    qemu_co_queue_init(&req->wait_queue);
-    QLIST_INSERT_HEAD(&job->inflight_reqs, req, list);
-}
-
-/* Forget about a completed request */
-static void cow_request_end(CowRequest *req)
-{
-    QLIST_REMOVE(req, list);
-    qemu_co_queue_restart_all(&req->wait_queue);
-}
-
 static int coroutine_fn backup_do_cow(BlockDriverState *bs,
                                       int64_t sector_num, int nb_sectors,
                                       bool *error_is_read)
@@ -104,8 +60,8 @@ static int coroutine_fn backup_do_cow(BlockDriverState *bs,
 
     trace_backup_do_cow_enter(job, start, sector_num, nb_sectors);
 
-    wait_for_overlapping_requests(job, start, end);
-    cow_request_begin(&cow_request, job, start, end);
+    wait_for_overlapping_requests(&job->cow_job, start, end);
+    cow_request_begin(&cow_request, &job->cow_job, start, end);
 
     for (; start < end; start++) {
         if (hbitmap_get(job->bitmap, start)) {
@@ -255,7 +211,7 @@ static void coroutine_fn backup_run(void *opaque)
     int64_t start, end;
     int ret = 0;
 
-    QLIST_INIT(&job->inflight_reqs);
+    QLIST_INIT(&job->cow_job.inflight_reqs);
     qemu_co_rwlock_init(&job->flush_rwlock);
 
     start = 0;
diff --git a/blockcow.c b/blockcow.c
new file mode 100644
index 0000000..c070a62
--- /dev/null
+++ b/blockcow.c
@@ -0,0 +1,52 @@
+/*
+ * QEMU block WAW
+ *
+ * Copyright Fujitsu, Corp. 2015
+ * Copyright (c) 2015 Intel Corporation
+ * Copyright (c) 2015 HUAWEI TECHNOLOGIES CO.,LTD.
+ *
+ * Authors:
+ *  Wen Congyang (address@hidden)
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "block/block.h"
+
+/* See if in-flight requests overlap and wait for them to complete */
+void coroutine_fn
+wait_for_overlapping_requests(CowJob *job, int64_t start, int64_t end)
+{
+    CowRequest *req;
+    bool retry;
+
+    do {
+        retry = false;
+        QLIST_FOREACH(req, &job->inflight_reqs, list) {
+            if (end > req->start && start < req->end) {
+                qemu_co_queue_wait(&req->wait_queue);
+                retry = true;
+                break;
+            }
+        }
+    } while (retry);
+}
+
+/* Keep track of an in-flight request */
+void cow_request_begin(CowRequest *req, CowJob *job,
+                       int64_t start, int64_t end)
+{
+    req->start = start;
+    req->end = end;
+    qemu_co_queue_init(&req->wait_queue);
+    QLIST_INSERT_HEAD(&job->inflight_reqs, req, list);
+}
+
+/* Forget about a completed request */
+void cow_request_end(CowRequest *req)
+{
+    QLIST_REMOVE(req, list);
+    qemu_co_queue_restart_all(&req->wait_queue);
+}
diff --git a/include/block/block.h b/include/block/block.h
index 632b9fc..0a55373 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -567,4 +567,21 @@ int bdrv_start_replication(BlockDriverState *bs, int mode);
 int bdrv_do_checkpoint(BlockDriverState *bs);
 int bdrv_stop_replication(BlockDriverState *bs);
 
+typedef struct CowRequest {
+    int64_t start;
+    int64_t end;
+    QLIST_ENTRY(CowRequest) list;
+    CoQueue wait_queue; /* coroutines blocked on this request */
+} CowRequest;
+
+typedef struct CowJob {
+    QLIST_HEAD(, CowRequest) inflight_reqs;
+} CowJob;
+
+void coroutine_fn
+wait_for_overlapping_requests(CowJob *job, int64_t start, int64_t end);
+void cow_request_begin(CowRequest *req, CowJob *job,
+                       int64_t start, int64_t end);
+void cow_request_end(CowRequest *req);
+
 #endif
-- 
2.1.0