stream: Use BlockBackend for I/O

This changes the streaming block job to use the job's BlockBackend for
performing the COR reads. job->bs isn't used by the streaming code any
more afterwards.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>

block/io.c

@@ -1117,15 +1117,6 @@ int coroutine_fn bdrv_co_readv_no_serialising(BlockDriverState *bs,
                             BDRV_REQ_NO_SERIALISING);
 }
 
-int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
-    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
-{
-    trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors);
-
-    return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov,
-                            BDRV_REQ_COPY_ON_READ);
-}
-
 #define MAX_WRITE_ZEROES_BOUNCE_BUFFER 32768
 
 static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,

block/stream.c

@@ -39,7 +39,7 @@ typedef struct StreamBlockJob {
     char *backing_file_str;
 } StreamBlockJob;
 
-static int coroutine_fn stream_populate(BlockDriverState *bs,
+static int coroutine_fn stream_populate(BlockBackend *blk,
                                         int64_t sector_num, int nb_sectors,
                                         void *buf)
 {
@@ -52,7 +52,8 @@ static int coroutine_fn stream_populate(BlockDriverState *bs,
     qemu_iovec_init_external(&qiov, &iov, 1);
 
     /* Copy-on-read the unallocated clusters */
-    return bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, &qiov);
+    return blk_co_preadv(blk, sector_num * BDRV_SECTOR_SIZE, qiov.size, &qiov,
+                         BDRV_REQ_COPY_ON_READ);
 }
 
 typedef struct {
@@ -64,6 +65,7 @@ static void stream_complete(BlockJob *job, void *opaque)
 {
     StreamBlockJob *s = container_of(job, StreamBlockJob, common);
     StreamCompleteData *data = opaque;
+    BlockDriverState *bs = blk_bs(job->blk);
     BlockDriverState *base = s->base;
 
     if (!block_job_is_cancelled(&s->common) && data->reached_end &&
@@ -75,8 +77,8 @@ static void stream_complete(BlockJob *job, void *opaque)
                 base_fmt = base->drv->format_name;
             }
         }
-        data->ret = bdrv_change_backing_file(job->bs, base_id, base_fmt);
-        bdrv_set_backing_hd(job->bs, base);
+        data->ret = bdrv_change_backing_file(bs, base_id, base_fmt);
+        bdrv_set_backing_hd(bs, base);
     }
 
     g_free(s->backing_file_str);
@@ -88,7 +90,8 @@ static void coroutine_fn stream_run(void *opaque)
 {
     StreamBlockJob *s = opaque;
     StreamCompleteData *data;
-    BlockDriverState *bs = s->common.bs;
+    BlockBackend *blk = s->common.blk;
+    BlockDriverState *bs = blk_bs(blk);
     BlockDriverState *base = s->base;
     int64_t sector_num = 0;
     int64_t end = -1;
@@ -159,7 +162,7 @@ wait:
                     goto wait;
                 }
             }
-            ret = stream_populate(bs, sector_num, n, buf);
+            ret = stream_populate(blk, sector_num, n, buf);
         }
         if (ret < 0) {
             BlockErrorAction action =

include/block/block.h

@@ -242,8 +242,6 @@ int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
     const void *buf, int count);
 int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
     int nb_sectors, QEMUIOVector *qiov);
-int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
-    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 int coroutine_fn bdrv_co_readv_no_serialising(BlockDriverState *bs,
     int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,

trace-events

@@ -72,7 +72,6 @@ bdrv_aio_readv(void *bs, int64_t sector_num, int nb_sectors, void *opaque) "bs %
 bdrv_aio_writev(void *bs, int64_t sector_num, int nb_sectors, void *opaque) "bs %p sector_num %"PRId64" nb_sectors %d opaque %p"
 bdrv_aio_write_zeroes(void *bs, int64_t sector_num, int nb_sectors, int flags, void *opaque) "bs %p sector_num %"PRId64" nb_sectors %d flags %#x opaque %p"
 bdrv_co_readv(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num %"PRId64" nb_sectors %d"
-bdrv_co_copy_on_readv(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num %"PRId64" nb_sectors %d"
 bdrv_co_readv_no_serialising(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num %"PRId64" nb_sectors %d"
 bdrv_co_writev(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num %"PRId64" nb_sectors %d"
 bdrv_co_write_zeroes(void *bs, int64_t sector_num, int nb_sector, int flags) "bs %p sector_num %"PRId64" nb_sectors %d flags %#x"