[Qemu-devel] [PATCH 3/3] block/backup: refactor write_flags

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

write flags are constant, let's store it in BackupBlockJob instead of
recalculating. It also makes two boolean fields to be unused, so,
drop them.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/backup.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/block/backup.c b/block/backup.c
index c5f941101a..4651649e9d 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -47,7 +47,6 @@ typedef struct BackupBlockJob {
     uint64_t len;
     uint64_t bytes_read;
     int64_t cluster_size;
-    bool compress;
     NotifierWithReturn before_write;
     QLIST_HEAD(, CowRequest) inflight_reqs;
 
@@ -55,7 +54,7 @@ typedef struct BackupBlockJob {
     bool use_copy_range;
     int64_t copy_range_size;
 
-    bool serialize_target_writes;
+    BdrvRequestFlags write_flags;
 } BackupBlockJob;
 
 static const BlockJobDriver backup_job_driver;
@@ -110,10 +109,6 @@ static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job,
     BlockBackend *blk = job->common.blk;
     int nbytes;
     int read_flags = is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0;
-    int write_flags =
-            (job->serialize_target_writes ? BDRV_REQ_SERIALISING : 0) |
-            (job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0);
-
 
     assert(QEMU_IS_ALIGNED(start, job->cluster_size));
     hbitmap_reset(job->copy_bitmap, start, job->cluster_size);
@@ -132,7 +127,7 @@ static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job,
     }
 
     ret = blk_co_pwrite(job->target, start, nbytes, *bounce_buffer,
-                        write_flags);
+                        job->write_flags);
     if (ret < 0) {
         trace_backup_do_cow_write_fail(job, start, ret);
         if (error_is_read) {
@@ -160,7 +155,6 @@ static int coroutine_fn backup_cow_with_offload(BackupBlockJob *job,
     BlockBackend *blk = job->common.blk;
     int nbytes;
     int read_flags = is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0;
-    int write_flags = job->serialize_target_writes ? BDRV_REQ_SERIALISING : 0;
 
     assert(QEMU_IS_ALIGNED(job->copy_range_size, job->cluster_size));
     assert(QEMU_IS_ALIGNED(start, job->cluster_size));
@@ -168,7 +162,7 @@ static int coroutine_fn backup_cow_with_offload(BackupBlockJob *job,
     nr_clusters = DIV_ROUND_UP(nbytes, job->cluster_size);
     hbitmap_reset(job->copy_bitmap, start, job->cluster_size * nr_clusters);
     ret = blk_co_copy_range(blk, start, job->target, start, nbytes,
-                            read_flags, write_flags);
+                            read_flags, job->write_flags);
     if (ret < 0) {
         trace_backup_do_cow_copy_range_fail(job, start, ret);
         hbitmap_set(job->copy_bitmap, start, job->cluster_size * nr_clusters);
@@ -638,10 +632,16 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
     job->sync_mode = sync_mode;
     job->sync_bitmap = sync_mode == MIRROR_SYNC_MODE_INCREMENTAL ?
                        sync_bitmap : NULL;
-    job->compress = compress;
 
-    /* Detect image-fleecing (and similar) schemes */
-    job->serialize_target_writes = bdrv_chain_contains(target, bs);
+    /*
+     * Set write flags:
+     *  1. Detect image-fleecing (and similar) schemes
+     *  2. Handle compression
+     */
+    job->write_flags =
+            (bdrv_chain_contains(target, bs) ? BDRV_REQ_SERIALISING : 0) |
+            (compress ? BDRV_REQ_WRITE_COMPRESSED : 0);
+
     job->cluster_size = cluster_size;
     job->copy_bitmap = copy_bitmap;
     copy_bitmap = NULL;
-- 
2.18.0