Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2019-08-15' into staging

[mirror_qemu.git] / block / io.c

diff --git a/block/io.c b/block/io.c
index 17a243cde9ad651580693fdaeb3b1d4acfbf7476..56bbf195bbfe2c9da0b55b336cc04690e01aafd3 100644 (file)
--- a/block/io.c
+++ b/block/io.c
@@ -1168,7 +1168,8 @@ bdrv_driver_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
 }
 
 static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
-        int64_t offset, unsigned int bytes, QEMUIOVector *qiov)
+        int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
+        int flags)
 {
     BlockDriverState *bs = child->bs;
 
@@ -1279,9 +1280,11 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
                 goto err;
             }
 
-            qemu_iovec_from_buf(qiov, progress, bounce_buffer + skip_bytes,
-                                pnum - skip_bytes);
-        } else {
+            if (!(flags & BDRV_REQ_PREFETCH)) {
+                qemu_iovec_from_buf(qiov, progress, bounce_buffer + skip_bytes,
+                                    pnum - skip_bytes);
+            }
+        } else if (!(flags & BDRV_REQ_PREFETCH)) {
             /* Read directly into the destination */
             qemu_iovec_init(&local_qiov, qiov->niov);
             qemu_iovec_concat(&local_qiov, qiov, progress, pnum - skip_bytes);
@@ -1332,7 +1335,8 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
      * potential fallback support, if we ever implement any read flags
      * to pass through to drivers.  For now, there aren't any
      * passthrough flags.  */
-    assert(!(flags & ~(BDRV_REQ_NO_SERIALISING | BDRV_REQ_COPY_ON_READ)));
+    assert(!(flags & ~(BDRV_REQ_NO_SERIALISING | BDRV_REQ_COPY_ON_READ |
+                       BDRV_REQ_PREFETCH)));
 
     /* Handle Copy on Read and associated serialisation */
     if (flags & BDRV_REQ_COPY_ON_READ) {
@@ -1360,7 +1364,9 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
         }
 
         if (!ret || pnum != bytes) {
-            ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov);
+            ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov, flags);
+            goto out;
+        } else if (flags & BDRV_REQ_PREFETCH) {
             goto out;
         }
     }