[Qemu-devel] [PULL 09/15] vdi: Replace bdrv_{read, write}() with bdrv_{pread, pwrite}()

[Kevin Wolf <kwolf@redhat.com>]

From: Alberto Garcia <berto@igalia.com>

There's only a couple of bdrv_read() and bdrv_write() calls left in
the vdi code, and they can be trivially replaced with the byte-based
bdrv_pread() and bdrv_pwrite().

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/vdi.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/block/vdi.c b/block/vdi.c
index e1c42ad732..d7ef6628e7 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -171,6 +171,8 @@ typedef struct {
     uint64_t unused2[7];
 } QEMU_PACKED VdiHeader;
 
+QEMU_BUILD_BUG_ON(sizeof(VdiHeader) != 512);
+
 typedef struct {
     /* The block map entries are little endian (even in memory). */
     uint32_t *bmap;
@@ -384,7 +386,7 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags,
 
     logout("\n");
 
-    ret = bdrv_read(bs->file, 0, (uint8_t *)&header, 1);
+    ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
     if (ret < 0) {
         goto fail;
     }
@@ -484,8 +486,8 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags,
         goto fail;
     }
 
-    ret = bdrv_read(bs->file, s->bmap_sector, (uint8_t *)s->bmap,
-                    bmap_size);
+    ret = bdrv_pread(bs->file, header.offset_bmap, s->bmap,
+                     bmap_size * SECTOR_SIZE);
     if (ret < 0) {
         goto fail_free_bmap;
     }
@@ -704,7 +706,7 @@ nonallocating_write:
         assert(VDI_IS_ALLOCATED(bmap_first));
         *header = s->header;
         vdi_header_to_le(header);
-        ret = bdrv_write(bs->file, 0, block, 1);
+        ret = bdrv_pwrite(bs->file, 0, block, sizeof(VdiHeader));
         g_free(block);
         block = NULL;
 
@@ -722,10 +724,11 @@ nonallocating_write:
         base = ((uint8_t *)&s->bmap[0]) + bmap_first * SECTOR_SIZE;
         logout("will write %u block map sectors starting from entry %u\n",
                n_sectors, bmap_first);
-        ret = bdrv_write(bs->file, offset, base, n_sectors);
+        ret = bdrv_pwrite(bs->file, offset * SECTOR_SIZE, base,
+                          n_sectors * SECTOR_SIZE);
     }
 
-    return ret;
+    return ret < 0 ? ret : 0;
 }
 
 static int coroutine_fn vdi_co_do_create(BlockdevCreateOptions *create_options,
-- 
2.20.1