[Qemu-devel] [PATCH 05/14] stream: Use BlockBackend for I/O

[Kevin Wolf <kwolf@redhat.com>]

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>
---
 block/block-backend.c          | 15 +++++++++++++++
 block/io.c                     |  9 ---------
 block/stream.c                 | 14 ++++++++------
 include/block/block.h          |  2 --
 include/sysemu/block-backend.h |  2 ++
 trace-events                   |  4 +++-
 6 files changed, 28 insertions(+), 18 deletions(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index 2932a58..25bb5ca 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -19,6 +19,7 @@
 #include "sysemu/sysemu.h"
 #include "qapi-event.h"
 #include "qemu/id.h"
+#include "trace.h"
 
 /* Number of coroutines to reserve per attached device model */
 #define COROUTINE_POOL_RESERVATION 64
@@ -793,6 +794,20 @@ static int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
     return bdrv_co_pwritev(blk_bs(blk), offset, bytes, qiov, flags);
 }
 
+int coroutine_fn blk_co_copy_on_readv(BlockBackend *blk,
+    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
+{
+    trace_blk_co_copy_on_readv(blk, blk_bs(blk), sector_num, nb_sectors);
+
+    if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
+        return -EINVAL;
+    }
+
+    return blk_co_preadv(blk, sector_num << BDRV_SECTOR_BITS,
+                         nb_sectors << BDRV_SECTOR_BITS, qiov,
+                         BDRV_REQ_COPY_ON_READ);
+}
+
 typedef struct BlkRwCo {
     BlockBackend *blk;
     int64_t offset;
diff --git a/block/io.c b/block/io.c
index 9aae030..8280e14 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1102,15 +1102,6 @@ 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,
diff --git a/block/stream.c b/block/stream.c
index 40aa322..70ed9be 100644
--- a/block/stream.c
+++ b/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 +52,7 @@ 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_copy_on_readv(blk, sector_num, nb_sectors, &qiov);
 }
 
 typedef struct {
@@ -64,6 +64,7 @@ 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 +76,8 @@ 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 +89,8 @@ 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 +161,7 @@ wait:
                     goto wait;
                 }
             }
-            ret = stream_populate(bs, sector_num, n, buf);
+            ret = stream_populate(blk, sector_num, n, buf);
         }
         if (ret < 0) {
             BlockErrorAction action =
diff --git a/include/block/block.h b/include/block/block.h
index a4eb5be..39b5812 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -243,8 +243,6 @@ 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,
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 12e4585..eac4d88 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -116,6 +116,8 @@ int blk_read(BlockBackend *blk, int64_t sector_num, uint8_t *buf,
              int nb_sectors);
 int blk_read_unthrottled(BlockBackend *blk, int64_t sector_num, uint8_t *buf,
                          int nb_sectors);
+int coroutine_fn blk_co_copy_on_readv(BlockBackend *blk,
+    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 int blk_write(BlockBackend *blk, int64_t sector_num, const uint8_t *buf,
               int nb_sectors);
 int blk_write_zeroes(BlockBackend *blk, int64_t sector_num,
diff --git a/trace-events b/trace-events
index 2f0ec6d..9beb588 100644
--- a/trace-events
+++ b/trace-events
@@ -61,6 +61,9 @@ virtio_console_chr_event(unsigned int port, int event) "port %u, event %d"
 bdrv_open_common(void *bs, const char *filename, int flags, const char *format_name) "bs %p filename \"%s\" flags %#x format_name \"%s\""
 bdrv_lock_medium(void *bs, bool locked) "bs %p locked %d"
 
+# block/block-backend.c
+blk_co_copy_on_readv(void *blk, void *bs, int64_t sector_num, int nb_sector) "blk %p bs %p sector_num %"PRId64" nb_sectors %d"
+
 # block/io.c
 bdrv_aio_discard(void *bs, int64_t sector_num, int nb_sectors, void *opaque) "bs %p sector_num %"PRId64" nb_sectors %d opaque %p"
 bdrv_aio_flush(void *bs, void *opaque) "bs %p opaque %p"
@@ -68,7 +71,6 @@ 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"
-- 
1.8.3.1