block: Open the underlying image file in generic code

Format drivers shouldn't need to bother with things like file names, but rather
just get an open BlockDriverState for the underlying protocol. This patch
introduces this behaviour for bdrv_open implementation. For protocols which
need to access the filename to open their file/device/connection/... a new
callback bdrv_file_open is introduced which doesn't get an underlying file
opened.

For now, also some of the more obscure formats use bdrv_file_open because they
open() the file themselves instead of using the block.c functions. They need to
be fixed in later patches.

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

1 files changed, 6 insertions, 11 deletions

diff --git a/block/blkdebug.c b/block/blkdebug.c
index 643c3978f8..bb4a91abc7 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -44,7 +44,6 @@ typedef struct BlkdebugVars {
 } BlkdebugVars;
 
 typedef struct BDRVBlkdebugState {
-    BlockDriverState *hd;
     BlkdebugVars vars;
     QLIST_HEAD(list, BlkdebugRule) rules[BLKDBG_EVENT_MAX];
 } BDRVBlkdebugState;
@@ -303,7 +302,7 @@ static int blkdebug_open(BlockDriverState *bs, const char *filename, int flags)
     filename = c + 1;
 
     /* Open the backing file */
-    ret = bdrv_file_open(&s->hd, filename, flags);
+    ret = bdrv_file_open(&bs->file, filename, flags);
     if (ret < 0) {
         return ret;
     }
@@ -362,7 +361,7 @@ static BlockDriverAIOCB *blkdebug_aio_readv(BlockDriverState *bs,
     }
 
     BlockDriverAIOCB *acb =
-        bdrv_aio_readv(s->hd, sector_num, qiov, nb_sectors, cb, opaque);
+        bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
     return acb;
 }
 
@@ -377,7 +376,7 @@ static BlockDriverAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
     }
 
     BlockDriverAIOCB *acb =
-        bdrv_aio_writev(s->hd, sector_num, qiov, nb_sectors, cb, opaque);
+        bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
     return acb;
 }
 
@@ -393,21 +392,17 @@ static void blkdebug_close(BlockDriverState *bs)
             qemu_free(rule);
         }
     }
-
-    bdrv_delete(s->hd);
 }
 
 static void blkdebug_flush(BlockDriverState *bs)
 {
-    BDRVBlkdebugState *s = bs->opaque;
-    bdrv_flush(s->hd);
+    bdrv_flush(bs->file);
 }
 
 static BlockDriverAIOCB *blkdebug_aio_flush(BlockDriverState *bs,
     BlockDriverCompletionFunc *cb, void *opaque)
 {
-    BDRVBlkdebugState *s = bs->opaque;
-    return bdrv_aio_flush(s->hd, cb, opaque);
+    return bdrv_aio_flush(bs->file, cb, opaque);
 }
 
 static void process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
@@ -456,7 +451,7 @@ static BlockDriver bdrv_blkdebug = {
 
     .instance_size      = sizeof(BDRVBlkdebugState),
 
-    .bdrv_open          = blkdebug_open,
+    .bdrv_file_open     = blkdebug_open,
     .bdrv_close         = blkdebug_close,
     .bdrv_flush         = blkdebug_flush,