[Qemu-devel] [PATCH 2/2] block/vdi: Do not use bdrv_pwrite_sync() for bmap

[Max Reitz <mreitz@redhat.com>]

The bmap can be rather large (maximum blocks per image count:
0x3fffffff; the bmap has a size of block_count * sizeof(uint32_t) bytes,
which makes 0xfffffffc bytes) and exceed INT_MAX. Using block layer
functions which take a byte count as an int is therefore not a good
idea. Use bdrv_write()+bdrv_flush() instead of bdrv_pwrite_sync().

See: https://bugzilla.redhat.com/show_bug.cgi?id=1154940

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/vdi.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/block/vdi.c b/block/vdi.c
index 19701ee..322efcd 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -783,11 +783,18 @@ static int vdi_create(const char *filename, QemuOpts *opts, Error **errp)
                 bmap[i] = VDI_UNALLOCATED;
             }
         }
-        ret = bdrv_pwrite_sync(bs, offset, bmap, bmap_size);
+        assert(!(offset % BDRV_SECTOR_SIZE));
+        ret = bdrv_write(bs, offset / BDRV_SECTOR_SIZE, (uint8_t *)bmap,
+                         bmap_size / BDRV_SECTOR_SIZE);
         if (ret < 0) {
             error_setg(errp, "Error writing bmap to %s", filename);
             goto exit;
         }
+        ret = bdrv_flush(bs);
+        if (ret < 0) {
+            error_setg(errp, "Error flushing bmap to %s", filename);
+            goto exit;
+        }
         offset += bmap_size;
     }
 
-- 
1.9.3