block: Add bdrv_co_readv/writev

Add new block driver callbacks bdrv_co_readv/writev, which work on a
QEMUIOVector like bdrv_aio_*, but don't need a callback. The function may only
be called inside a coroutine, so a block driver implementing this interface can
yield instead of blocking during I/O.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/block.c b/block.c
index 4c66b2cf40..1329299ed7 100644
--- a/block.c
+++ b/block.c
@@ -1110,6 +1110,51 @@ int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
     return 0;
 }
 
+int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
+    int nb_sectors, QEMUIOVector *qiov)
+{
+    BlockDriver *drv = bs->drv;
+
+    trace_bdrv_co_readv(bs, sector_num, nb_sectors);
+
+    if (!drv) {
+        return -ENOMEDIUM;
+    }
+    if (bdrv_check_request(bs, sector_num, nb_sectors)) {
+        return -EIO;
+    }
+
+    return drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
+}
+
+int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
+    int nb_sectors, QEMUIOVector *qiov)
+{
+    BlockDriver *drv = bs->drv;
+
+    trace_bdrv_co_writev(bs, sector_num, nb_sectors);
+
+    if (!bs->drv) {
+        return -ENOMEDIUM;
+    }
+    if (bs->read_only) {
+        return -EACCES;
+    }
+    if (bdrv_check_request(bs, sector_num, nb_sectors)) {
+        return -EIO;
+    }
+
+    if (bs->dirty_bitmap) {
+        set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
+    }
+
+    if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
+        bs->wr_highest_sector = sector_num + nb_sectors - 1;
+    }
+
+    return drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
+}
+
 /**
  * Truncate file to 'offset' bytes (needed only for file protocols)
  */